cyw43: remove feature(concat_bytes).

STM32 DAC: update to new PAC, combine ch1/ch2, fix trigger selection

.github/ci/build-stable.sh

@@ -12,9 +12,19 @@ export CARGO_TARGET_DIR=/ci/cache/target
 # used when pointing stm32-metapac to a CI-built one.
 export CARGO_NET_GIT_FETCH_WITH_CLI=true
 
+# Restore lockfiles
+if [ -f /ci/cache/lockfiles.tar ]; then
+    echo Restoring lockfiles...
+    tar xf /ci/cache/lockfiles.tar
+fi
+
 hashtime restore /ci/cache/filetime.json || true
 hashtime save /ci/cache/filetime.json
 
 sed -i 's/channel.*/channel = "stable"/g' rust-toolchain.toml
 
 ./ci_stable.sh
+
+# Save lockfiles
+echo Saving lockfiles...
+find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+

.github/ci/build.sh

@@ -18,7 +18,17 @@ fi
 # used when pointing stm32-metapac to a CI-built one.
 export CARGO_NET_GIT_FETCH_WITH_CLI=true
 
+# Restore lockfiles
+if [ -f /ci/cache/lockfiles.tar ]; then
+    echo Restoring lockfiles...
+    tar xf /ci/cache/lockfiles.tar
+fi
+
 hashtime restore /ci/cache/filetime.json || true
 hashtime save /ci/cache/filetime.json
 
 ./ci.sh
+
+# Save lockfiles
+echo Saving lockfiles...
+find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+

.github/ci/test.sh

@@ -15,6 +15,9 @@ export CARGO_NET_GIT_FETCH_WITH_CLI=true
 hashtime restore /ci/cache/filetime.json || true
 hashtime save /ci/cache/filetime.json
 
+MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --manifest-path ./embassy-executor/Cargo.toml
+MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --manifest-path ./embassy-executor/Cargo.toml --features nightly
+
 cargo test --manifest-path ./embassy-sync/Cargo.toml 
 cargo test --manifest-path ./embassy-embedded-hal/Cargo.toml 
 cargo test --manifest-path ./embassy-hal-internal/Cargo.toml 

ci.sh

@@ -38,6 +38,7 @@ cargo batch  \
     --- build --release --manifest-path embassy-sync/Cargo.toml --target thumbv6m-none-eabi --features nightly,defmt \
     --- build --release --manifest-path embassy-time/Cargo.toml --target thumbv6m-none-eabi --features nightly,defmt,defmt-timestamp-uptime,tick-hz-32_768,generic-queue-8 \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv4,medium-ethernet \
+    --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv4,igmp,medium-ethernet \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,dhcpv4,medium-ethernet \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,dhcpv4,medium-ethernet,nightly,dhcpv4-hostname \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv6,medium-ethernet \
@@ -110,6 +111,7 @@ cargo batch  \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32h753zi,defmt,exti,time-driver-any,unstable-traits,time \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32h735zg,defmt,exti,time-driver-any,unstable-traits,time \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32h755zi-cm7,defmt,exti,time-driver-any,unstable-traits,time \
+    --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32h725re,defmt,exti,time-driver-any,unstable-traits,time \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32h7b3ai,defmt,exti,time-driver-any,unstable-traits,time \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32l476vg,defmt,exti,time-driver-any,unstable-traits,time \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32l422cb,defmt,exti,time-driver-any,unstable-traits,time \

cyw43/src/control.rs

@@ -1,4 +1,5 @@
 use core::cmp::{max, min};
+use core::iter::zip;
 
 use embassy_net_driver_channel as ch;
 use embassy_net_driver_channel::driver::{HardwareAddress, LinkState};
@@ -16,6 +17,12 @@ pub struct Error {
     pub status: u32,
 }
 
+#[derive(Debug)]
+pub enum AddMulticastAddressError {
+    NotMulticast,
+    NoFreeSlots,
+}
+
 pub struct Control<'a> {
     state_ch: ch::StateRunner<'a>,
     events: &'a Events,
@@ -316,6 +323,54 @@ impl<'a> Control<'a> {
         self.set_iovar_u32x2("bss", 0, 1).await; // bss = BSS_UP
     }
 
+    /// Add specified address to the list of hardware addresses the device
+    /// listens on. The address must be a Group address (I/G bit set). Up
+    /// to 10 addresses are supported by the firmware. Returns the number of
+    /// address slots filled after adding, or an error.
+    pub async fn add_multicast_address(&mut self, address: [u8; 6]) -> Result<usize, AddMulticastAddressError> {
+        // The firmware seems to ignore non-multicast addresses, so let's
+        // prevent the user from adding them and wasting space.
+        if address[0] & 0x01 != 1 {
+            return Err(AddMulticastAddressError::NotMulticast);
+        }
+
+        let mut buf = [0; 64];
+        self.get_iovar("mcast_list", &mut buf).await;
+
+        let n = u32::from_le_bytes(buf[..4].try_into().unwrap()) as usize;
+        let (used, free) = buf[4..].split_at_mut(n * 6);
+
+        if used.chunks(6).any(|a| a == address) {
+            return Ok(n);
+        }
+
+        if free.len() < 6 {
+            return Err(AddMulticastAddressError::NoFreeSlots);
+        }
+
+        free[..6].copy_from_slice(&address);
+        let n = n + 1;
+        buf[..4].copy_from_slice(&(n as u32).to_le_bytes());
+
+        self.set_iovar_v::<80>("mcast_list", &buf).await;
+        Ok(n)
+    }
+
+    /// Retrieve the list of configured multicast hardware addresses.
+    pub async fn list_mulistcast_addresses(&mut self, result: &mut [[u8; 6]; 10]) -> usize {
+        let mut buf = [0; 64];
+        self.get_iovar("mcast_list", &mut buf).await;
+
+        let n = u32::from_le_bytes(buf[..4].try_into().unwrap()) as usize;
+        let used = &buf[4..][..n * 6];
+
+        for (addr, output) in zip(used.chunks(6), result.iter_mut()) {
+            output.copy_from_slice(addr)
+        }
+
+        n
+    }
+
     async fn set_iovar_u32x2(&mut self, name: &str, val1: u32, val2: u32) {
         let mut buf = [0; 8];
         buf[0..4].copy_from_slice(&val1.to_le_bytes());

cyw43/src/lib.rs

@@ -1,6 +1,6 @@
 #![no_std]
 #![no_main]
-#![feature(async_fn_in_trait, type_alias_impl_trait, concat_bytes)]
+#![feature(async_fn_in_trait, type_alias_impl_trait)]
 #![allow(stable_features, unknown_lints, async_fn_in_trait)]
 #![deny(unused_must_use)]
 
@@ -27,7 +27,7 @@ use ioctl::IoctlState;
 
 use crate::bus::Bus;
 pub use crate::bus::SpiBusCyw43;
-pub use crate::control::{Control, Error as ControlError, Scanner};
+pub use crate::control::{AddMulticastAddressError, Control, Error as ControlError, Scanner};
 pub use crate::runner::Runner;
 pub use crate::structs::BssInfo;
 

cyw43/src/nvram.rs

@@ -1,54 +1,48 @@
-macro_rules! nvram {
-    ($($s:literal,)*) => {
-        concat_bytes!($($s, b"\x00",)* b"\x00\x00")
-    };
-}
-
-pub static NVRAM: &'static [u8] = &*nvram!(
-    b"NVRAMRev=$Rev$",
-    b"manfid=0x2d0",
-    b"prodid=0x0727",
-    b"vendid=0x14e4",
-    b"devid=0x43e2",
-    b"boardtype=0x0887",
-    b"boardrev=0x1100",
-    b"boardnum=22",
-    b"macaddr=00:A0:50:b5:59:5e",
-    b"sromrev=11",
-    b"boardflags=0x00404001",
-    b"boardflags3=0x04000000",
-    b"xtalfreq=37400",
-    b"nocrc=1",
-    b"ag0=255",
-    b"aa2g=1",
-    b"ccode=ALL",
-    b"pa0itssit=0x20",
-    b"extpagain2g=0",
-    b"pa2ga0=-168,6649,-778",
-    b"AvVmid_c0=0x0,0xc8",
-    b"cckpwroffset0=5",
-    b"maxp2ga0=84",
-    b"txpwrbckof=6",
-    b"cckbw202gpo=0",
-    b"legofdmbw202gpo=0x66111111",
-    b"mcsbw202gpo=0x77711111",
-    b"propbw202gpo=0xdd",
-    b"ofdmdigfilttype=18",
-    b"ofdmdigfilttypebe=18",
-    b"papdmode=1",
-    b"papdvalidtest=1",
-    b"pacalidx2g=45",
-    b"papdepsoffset=-30",
-    b"papdendidx=58",
-    b"ltecxmux=0",
-    b"ltecxpadnum=0x0102",
-    b"ltecxfnsel=0x44",
-    b"ltecxgcigpio=0x01",
-    b"il0macaddr=00:90:4c:c5:12:38",
-    b"wl0id=0x431b",
-    b"deadman_to=0xffffffff",
-    b"muxenab=0x100",
-    b"spurconfig=0x3",
-    b"glitch_based_crsmin=1",
-    b"btc_mode=1",
-);
+pub static NVRAM: &'static [u8] = b"
+    NVRAMRev=$Rev$\x00\
+    manfid=0x2d0\x00\
+    prodid=0x0727\x00\
+    vendid=0x14e4\x00\
+    devid=0x43e2\x00\
+    boardtype=0x0887\x00\
+    boardrev=0x1100\x00\
+    boardnum=22\x00\
+    macaddr=00:A0:50:b5:59:5e\x00\
+    sromrev=11\x00\
+    boardflags=0x00404001\x00\
+    boardflags3=0x04000000\x00\
+    xtalfreq=37400\x00\
+    nocrc=1\x00\
+    ag0=255\x00\
+    aa2g=1\x00\
+    ccode=ALL\x00\
+    pa0itssit=0x20\x00\
+    extpagain2g=0\x00\
+    pa2ga0=-168,6649,-778\x00\
+    AvVmid_c0=0x0,0xc8\x00\
+    cckpwroffset0=5\x00\
+    maxp2ga0=84\x00\
+    txpwrbckof=6\x00\
+    cckbw202gpo=0\x00\
+    legofdmbw202gpo=0x66111111\x00\
+    mcsbw202gpo=0x77711111\x00\
+    propbw202gpo=0xdd\x00\
+    ofdmdigfilttype=18\x00\
+    ofdmdigfilttypebe=18\x00\
+    papdmode=1\x00\
+    papdvalidtest=1\x00\
+    pacalidx2g=45\x00\
+    papdepsoffset=-30\x00\
+    papdendidx=58\x00\
+    ltecxmux=0\x00\
+    ltecxpadnum=0x0102\x00\
+    ltecxfnsel=0x44\x00\
+    ltecxgcigpio=0x01\x00\
+    il0macaddr=00:90:4c:c5:12:38\x00\
+    wl0id=0x431b\x00\
+    deadman_to=0xffffffff\x00\
+    muxenab=0x100\x00\
+    spurconfig=0x3\x00\
+    glitch_based_crsmin=1\x00\
+    btc_mode=1\x00\
+    \x00";

docs/modules/ROOT/nav.adoc

@@ -10,3 +10,4 @@
 * xref:examples.adoc[Examples]
 * xref:developer.adoc[Developer]
 ** xref:developer_stm32.adoc[Developer: STM32]
+* xref:faq.adoc[Frequently Asked Questions]

docs/modules/ROOT/pages/faq.adoc

@@ -0,0 +1,38 @@
+= Frequently Asked Questions
+
+These are a list of unsorted, commonly asked questions and answers.
+
+Please feel free to add items to link:https://github.com/embassy-rs/embassy/edit/main/docs/modules/ROOT/pages/faq.adoc[this page], especially if someone in the chat answered a question for you!
+
+== How to deploy to RP2040 without a debugging probe.
+
+Install link:https://github.com/JoNil/elf2uf2-rs[elf2uf2-rs] for converting the generated elf binary into a uf2 file.
+
+Configure the runner to use this tool, add this to `.cargo/config.toml`:
+[source,toml]
+----
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+runner = "elf2uf2-rs --deploy --serial --verbose"
+----
+
+The command-line parameters `--deploy` will detect your device and upload the binary, `--serial` starts a serial connection. See the documentation for more info.
+
+== Missing main macro
+
+If you see an error like this:
+
+[source,rust]
+----
+#[embassy_executor::main]
+|                   ^^^^ could not find `main` in `embassy_executor`
+----
+
+You are likely missing some features of the `embassy-executor` crate.
+
+For Cortex-M targets, consider making sure that ALL of the following features are active in your `Cargo.toml` for the `embassy-executor` crate:
+
+* `arch-cortex-m`
+* `executor-thread`
+* `nightly`
+
+For Xtensa ESP32, consider using the executors and `#[main]` macro provided by your appropriate link:https://crates.io/crates/esp-hal-common[HAL crate].

embassy-embedded-hal/src/lib.rs

@@ -1,5 +1,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(feature = "nightly", feature(async_fn_in_trait, impl_trait_projections, try_blocks))]
+#![cfg_attr(feature = "nightly", feature(async_fn_in_trait, impl_trait_projections))]
 #![cfg_attr(feature = "nightly", allow(stable_features, unknown_lints, async_fn_in_trait))]
 #![warn(missing_docs)]
 

embassy-embedded-hal/src/shared_bus/asynch/spi.rs

@@ -66,19 +66,29 @@ where
         let mut bus = self.bus.lock().await;
         self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
-        let op_res: Result<(), BUS::Error> = try {
+        let op_res = 'ops: {
             for op in operations {
-                match op {
-                    Operation::Read(buf) => bus.read(buf).await?,
-                    Operation::Write(buf) => bus.write(buf).await?,
-                    Operation::Transfer(read, write) => bus.transfer(read, write).await?,
-                    Operation::TransferInPlace(buf) => bus.transfer_in_place(buf).await?,
+                let res = match op {
+                    Operation::Read(buf) => bus.read(buf).await,
+                    Operation::Write(buf) => bus.write(buf).await,
+                    Operation::Transfer(read, write) => bus.transfer(read, write).await,
+                    Operation::TransferInPlace(buf) => bus.transfer_in_place(buf).await,
                     #[cfg(not(feature = "time"))]
-                    Operation::DelayUs(_) => return Err(SpiDeviceError::DelayUsNotSupported),
+                    Operation::DelayUs(us) => return Err(SpiDeviceError::DelayUsNotSupported),
                     #[cfg(feature = "time")]
-                    Operation::DelayUs(us) => embassy_time::Timer::after_micros(*us as _).await,
+                    Operation::DelayUs(us) => match bus.flush().await {
+                        Err(e) => Err(e),
+                        Ok(()) => {
+                            embassy_time::Timer::after_micros(*us as _).await;
+                            Ok(())
+                        }
+                    },
+                };
+                if let Err(e) = res {
+                    break 'ops Err(e);
                 }
             }
+            Ok(())
         };
 
         // On failure, it's important to still flush and deassert CS.
@@ -131,19 +141,29 @@ where
         bus.set_config(&self.config).map_err(|_| SpiDeviceError::Config)?;
         self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
-        let op_res: Result<(), BUS::Error> = try {
+        let op_res = 'ops: {
             for op in operations {
-                match op {
-                    Operation::Read(buf) => bus.read(buf).await?,
-                    Operation::Write(buf) => bus.write(buf).await?,
-                    Operation::Transfer(read, write) => bus.transfer(read, write).await?,
-                    Operation::TransferInPlace(buf) => bus.transfer_in_place(buf).await?,
+                let res = match op {
+                    Operation::Read(buf) => bus.read(buf).await,
+                    Operation::Write(buf) => bus.write(buf).await,
+                    Operation::Transfer(read, write) => bus.transfer(read, write).await,
+                    Operation::TransferInPlace(buf) => bus.transfer_in_place(buf).await,
                     #[cfg(not(feature = "time"))]
-                    Operation::DelayUs(_) => return Err(SpiDeviceError::DelayUsNotSupported),
+                    Operation::DelayUs(us) => return Err(SpiDeviceError::DelayUsNotSupported),
                     #[cfg(feature = "time")]
-                    Operation::DelayUs(us) => embassy_time::Timer::after_micros(*us as _).await,
+                    Operation::DelayUs(us) => match bus.flush().await {
+                        Err(e) => Err(e),
+                        Ok(()) => {
+                            embassy_time::Timer::after_micros(*us as _).await;
+                            Ok(())
+                        }
+                    },
+                };
+                if let Err(e) = res {
+                    break 'ops Err(e);
                 }
             }
+            Ok(())
         };
 
         // On failure, it's important to still flush and deassert CS.

embassy-executor/CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.3.3 - 2023-11-15
+
+- Add `main` macro reexport for Xtensa arch.
+- Remove use of `atomic-polyfill`. The executor now has multiple implementations of its internal data structures for cases where the target supports atomics or doesn't.
+
 ## 0.3.2 - 2023-11-06
 
 - Use `atomic-polyfill` for `riscv32`

embassy-executor/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "embassy-executor"
-version = "0.3.2"
+version = "0.3.3"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "async/await executor designed for embedded usage"
@@ -27,6 +27,30 @@ default-target = "thumbv7em-none-eabi"
 targets = ["thumbv7em-none-eabi"]
 features = ["nightly", "defmt", "arch-cortex-m", "executor-thread", "executor-interrupt"]
 
+[dependencies]
+defmt = { version = "0.3", optional = true }
+log = { version = "0.4.14", optional = true }
+rtos-trace = { version = "0.1.2", optional = true }
+
+embassy-macros = { version = "0.2.1", path = "../embassy-macros" }
+embassy-time = { version = "0.1.5", path = "../embassy-time", optional = true}
+critical-section = "1.1"
+
+# needed for riscv
+# remove when https://github.com/rust-lang/rust/pull/114499 is merged
+portable-atomic = { version = "1.5", optional = true }
+
+# arch-cortex-m dependencies
+cortex-m = { version = "0.7.6", optional = true }
+
+# arch-wasm dependencies
+wasm-bindgen = { version = "0.2.82", optional = true }
+js-sys = { version = "0.3", optional = true }
+
+[dev-dependencies]
+critical-section = { version = "1.1", features = ["std"] }
+
+
 [features]
 
 # Architecture
@@ -34,7 +58,7 @@ _arch = [] # some arch was picked
 arch-std = ["_arch", "critical-section/std"]
 arch-cortex-m = ["_arch", "dep:cortex-m"]
 arch-xtensa = ["_arch"]
-arch-riscv32 = ["_arch"]
+arch-riscv32 = ["_arch", "dep:portable-atomic"]
 arch-wasm = ["_arch", "dep:wasm-bindgen", "dep:js-sys"]
 
 # Enable the thread-mode executor (using WFE/SEV in Cortex-M, WFI in other embedded archs)
@@ -43,28 +67,53 @@ executor-thread = []
 executor-interrupt = []
 
 # Enable nightly-only features
-nightly = []
+nightly = ["embassy-macros/nightly"]
 
 turbowakers = []
 
 integrated-timers = ["dep:embassy-time"]
 
-# Trace interrupt invocations with rtos-trace.
-rtos-trace-interrupt = ["rtos-trace", "embassy-macros/rtos-trace-interrupt"]
+# BEGIN AUTOGENERATED CONFIG FEATURES
+# Generated by gen_config.py. DO NOT EDIT.
+task-arena-size-64 = []
+task-arena-size-128 = []
+task-arena-size-192 = []
+task-arena-size-256 = []
+task-arena-size-320 = []
+task-arena-size-384 = []
+task-arena-size-512 = []
+task-arena-size-640 = []
+task-arena-size-768 = []
+task-arena-size-1024 = []
+task-arena-size-1280 = []
+task-arena-size-1536 = []
+task-arena-size-2048 = []
+task-arena-size-2560 = []
+task-arena-size-3072 = []
+task-arena-size-4096 = [] # Default
+task-arena-size-5120 = []
+task-arena-size-6144 = []
+task-arena-size-8192 = []
+task-arena-size-10240 = []
+task-arena-size-12288 = []
+task-arena-size-16384 = []
+task-arena-size-20480 = []
+task-arena-size-24576 = []
+task-arena-size-32768 = []
+task-arena-size-40960 = []
+task-arena-size-49152 = []
+task-arena-size-65536 = []
+task-arena-size-81920 = []
+task-arena-size-98304 = []
+task-arena-size-131072 = []
+task-arena-size-163840 = []
+task-arena-size-196608 = []
+task-arena-size-262144 = []
+task-arena-size-327680 = []
+task-arena-size-393216 = []
+task-arena-size-524288 = []
+task-arena-size-655360 = []
+task-arena-size-786432 = []
+task-arena-size-1048576 = []
 
-[dependencies]
-defmt = { version = "0.3", optional = true }
-log = { version = "0.4.14", optional = true }
-rtos-trace = { version = "0.1.2", optional = true }
-
-embassy-macros = { version = "0.2.1", path = "../embassy-macros" }
-embassy-time = { version = "0.1.5", path = "../embassy-time", optional = true}
-atomic-polyfill = "1.0.1"
-critical-section = "1.1"
-
-# arch-cortex-m dependencies
-cortex-m = { version = "0.7.6", optional = true }
-
-# arch-wasm dependencies
-wasm-bindgen = { version = "0.2.82", optional = true }
-js-sys = { version = "0.3", optional = true }
+# END AUTOGENERATED CONFIG FEATURES

embassy-executor/README.md

@@ -2,10 +2,36 @@
 
 An async/await executor designed for embedded usage.
 
-- No `alloc`, no heap needed. Task futures are statically allocated.
+- No `alloc`, no heap needed.
+- With nightly Rust, task futures can be fully statically allocated.
 - No "fixed capacity" data structures, executor works with 1 or 1000 tasks without needing config/tuning.
 - Integrated timer queue: sleeping is easy, just do `Timer::after_secs(1).await;`.
 - No busy-loop polling: CPU sleeps when there's no work to do, using interrupts or `WFE/SEV`.
 - Efficient polling: a wake will only poll the woken task, not all of them.
 - Fair: a task can't monopolize CPU time even if it's constantly being woken. All other tasks get a chance to run before a given task gets polled for the second time.
 - Creating multiple executor instances is supported, to run tasks with multiple priority levels. This allows higher-priority tasks to preempt lower-priority tasks.
+
+## Task arena
+
+When the `nightly` Cargo feature is not enabled, `embassy-executor` allocates tasks out of an arena (a very simple bump allocator).
+
+If the task arena gets full, the program will panic at runtime. To guarantee this doesn't happen, you must set the size to the sum of sizes of all tasks.
+
+Tasks are allocated from the arena when spawned for the first time. If the task exists, the allocation is not released to the arena, but can be reused to spawn the task again. For multiple-instance tasks (like `#[embassy_executor::task(pool_size = 4)]`), the first spawn will allocate memory for all instances. This is done for performance and to increase predictability (for example, spawning at least 1 instance of every task at boot guarantees an immediate panic if the arena is too small, while allocating instances on-demand could delay the panic to only when the program is under load).
+
+The arena size can be configured in two ways:
+
+- Via Cargo features: enable a Cargo feature like `task-arena-size-8192`. Only a selection of values
+  is available, check `Cargo.toml` for the list.
+- Via environment variables at build time: set the variable named `EMBASSY_EXECUTOR_TASK_ARENA_SIZE`. For example
+  `EMBASSY_EXECUTOR_TASK_ARENA_SIZE=4321 cargo build`. You can also set them in the `[env]` section of `.cargo/config.toml`.
+  Any value can be set, unlike with Cargo features.
+
+Environment variables take precedence over Cargo features. If two Cargo features are enabled for the same setting
+with different values, compilation fails.
+
+## Statically allocating tasks
+
+When using nightly Rust, enable the `nightly` Cargo feature. This will make `embassy-executor` use the `type_alias_impl_trait` feature to allocate all tasks in `static`s. Each task gets its own `static`, with the exact size to hold the task (or multiple instances of it, if using `pool_size`) calculated automatically at compile time. If tasks don't fit in RAM, this is detected at compile time by the linker. Runtime panics due to running out of memory are not possible.
+
+The configured arena size is ignored, no arena is used at all.

embassy-executor/build.rs

@@ -1,6 +1,97 @@
-use std::env;
+use std::collections::HashMap;
+use std::fmt::Write;
+use std::path::PathBuf;
+use std::{env, fs};
+
+static CONFIGS: &[(&str, usize)] = &[
+    // BEGIN AUTOGENERATED CONFIG FEATURES
+    // Generated by gen_config.py. DO NOT EDIT.
+    ("TASK_ARENA_SIZE", 4096),
+    // END AUTOGENERATED CONFIG FEATURES
+];
+
+struct ConfigState {
+    value: usize,
+    seen_feature: bool,
+    seen_env: bool,
+}
 
 fn main() {
+    let crate_name = env::var("CARGO_PKG_NAME")
+        .unwrap()
+        .to_ascii_uppercase()
+        .replace('-', "_");
+
+    // only rebuild if build.rs changed. Otherwise Cargo will rebuild if any
+    // other file changed.
+    println!("cargo:rerun-if-changed=build.rs");
+
+    // Rebuild if config envvar changed.
+    for (name, _) in CONFIGS {
+        println!("cargo:rerun-if-env-changed={crate_name}_{name}");
+    }
+
+    let mut configs = HashMap::new();
+    for (name, default) in CONFIGS {
+        configs.insert(
+            *name,
+            ConfigState {
+                value: *default,
+                seen_env: false,
+                seen_feature: false,
+            },
+        );
+    }
+
+    let prefix = format!("{crate_name}_");
+    for (var, value) in env::vars() {
+        if let Some(name) = var.strip_prefix(&prefix) {
+            let Some(cfg) = configs.get_mut(name) else {
+                panic!("Unknown env var {name}")
+            };
+
+            let Ok(value) = value.parse::<usize>() else {
+                panic!("Invalid value for env var {name}: {value}")
+            };
+
+            cfg.value = value;
+            cfg.seen_env = true;
+        }
+
+        if let Some(feature) = var.strip_prefix("CARGO_FEATURE_") {
+            if let Some(i) = feature.rfind('_') {
+                let name = &feature[..i];
+                let value = &feature[i + 1..];
+                if let Some(cfg) = configs.get_mut(name) {
+                    let Ok(value) = value.parse::<usize>() else {
+                        panic!("Invalid value for feature {name}: {value}")
+                    };
+
+                    // envvars take priority.
+                    if !cfg.seen_env {
+                        if cfg.seen_feature {
+                            panic!("multiple values set for feature {}: {} and {}", name, cfg.value, value);
+                        }
+
+                        cfg.value = value;
+                        cfg.seen_feature = true;
+                    }
+                }
+            }
+        }
+    }
+
+    let mut data = String::new();
+
+    for (name, cfg) in &configs {
+        writeln!(&mut data, "pub const {}: usize = {};", name, cfg.value).unwrap();
+    }
+
+    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let out_file = out_dir.join("config.rs").to_string_lossy().to_string();
+    fs::write(out_file, data).unwrap();
+
+    // cortex-m targets
     let target = env::var("TARGET").unwrap();
 
     if target.starts_with("thumbv6m-") {

embassy-executor/gen_config.py

@@ -0,0 +1,82 @@
+import os
+
+abspath = os.path.abspath(__file__)
+dname = os.path.dirname(abspath)
+os.chdir(dname)
+
+features = []
+
+
+def feature(name, default, min=None, max=None, pow2=None, vals=None, factors=[]):
+    if vals is None:
+        assert min is not None
+        assert max is not None
+
+        vals = set()
+        val = min
+        while val <= max:
+            vals.add(val)
+            for f in factors:
+                if val * f <= max:
+                    vals.add(val * f)
+            if (pow2 == True or (isinstance(pow2, int) and val >= pow2)) and val > 0:
+                val *= 2
+            else:
+                val += 1
+        vals.add(default)
+        vals = sorted(list(vals))
+
+    features.append(
+        {
+            "name": name,
+            "default": default,
+            "vals": vals,
+        }
+    )
+
+
+feature(
+    "task_arena_size", default=4096, min=64, max=1024 * 1024, pow2=True, factors=[3, 5]
+)
+
+# ========= Update Cargo.toml
+
+things = ""
+for f in features:
+    name = f["name"].replace("_", "-")
+    for val in f["vals"]:
+        things += f"{name}-{val} = []"
+        if val == f["default"]:
+            things += " # Default"
+        things += "\n"
+    things += "\n"
+
+SEPARATOR_START = "# BEGIN AUTOGENERATED CONFIG FEATURES\n"
+SEPARATOR_END = "# END AUTOGENERATED CONFIG FEATURES\n"
+HELP = "# Generated by gen_config.py. DO NOT EDIT.\n"
+with open("Cargo.toml", "r") as f:
+    data = f.read()
+before, data = data.split(SEPARATOR_START, maxsplit=1)
+_, after = data.split(SEPARATOR_END, maxsplit=1)
+data = before + SEPARATOR_START + HELP + things + SEPARATOR_END + after
+with open("Cargo.toml", "w") as f:
+    f.write(data)
+
+
+# ========= Update build.rs
+
+things = ""
+for f in features:
+    name = f["name"].upper()
+    things += f'    ("{name}", {f["default"]}),\n'
+
+SEPARATOR_START = "// BEGIN AUTOGENERATED CONFIG FEATURES\n"
+SEPARATOR_END = "// END AUTOGENERATED CONFIG FEATURES\n"
+HELP = "    // Generated by gen_config.py. DO NOT EDIT.\n"
+with open("build.rs", "r") as f:
+    data = f.read()
+before, data = data.split(SEPARATOR_START, maxsplit=1)
+_, after = data.split(SEPARATOR_END, maxsplit=1)
+data = before + SEPARATOR_START + HELP + things + "    " + SEPARATOR_END + after
+with open("build.rs", "w") as f:
+    f.write(data)

embassy-executor/src/arch/cortex_m.rs

@@ -51,7 +51,6 @@ mod thread {
     use core::arch::asm;
     use core::marker::PhantomData;
 
-    #[cfg(feature = "nightly")]
     pub use embassy_macros::main_cortex_m as main;
 
     use crate::{raw, Spawner};
@@ -115,12 +114,12 @@ mod thread {
 pub use interrupt::*;
 #[cfg(feature = "executor-interrupt")]
 mod interrupt {
-    use core::cell::UnsafeCell;
+    use core::cell::{Cell, UnsafeCell};
     use core::mem::MaybeUninit;
 
-    use atomic_polyfill::{AtomicBool, Ordering};
     use cortex_m::interrupt::InterruptNumber;
     use cortex_m::peripheral::NVIC;
+    use critical_section::Mutex;
 
     use crate::raw;
 
@@ -146,7 +145,7 @@ mod interrupt {
     /// It is somewhat more complex to use, it's recommended to use the thread-mode
     /// [`Executor`] instead, if it works for your use case.
     pub struct InterruptExecutor {
-        started: AtomicBool,
+        started: Mutex<Cell<bool>>,
         executor: UnsafeCell<MaybeUninit<raw::Executor>>,
     }
 
@@ -158,7 +157,7 @@ mod interrupt {
         #[inline]
         pub const fn new() -> Self {
             Self {
-                started: AtomicBool::new(false),
+                started: Mutex::new(Cell::new(false)),
                 executor: UnsafeCell::new(MaybeUninit::uninit()),
             }
         }
@@ -167,7 +166,8 @@ mod interrupt {
         ///
         /// # Safety
         ///
-        /// You MUST call this from the interrupt handler, and from nowhere else.
+        /// - You MUST call this from the interrupt handler, and from nowhere else.
+        /// - You must not call this before calling `start()`.
         pub unsafe fn on_interrupt(&'static self) {
             let executor = unsafe { (&*self.executor.get()).assume_init_ref() };
             executor.poll();
@@ -196,11 +196,7 @@ mod interrupt {
         /// do it after.
         ///
         pub fn start(&'static self, irq: impl InterruptNumber) -> crate::SendSpawner {
-            if self
-                .started
-                .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed)
-                .is_err()
-            {
+            if critical_section::with(|cs| self.started.borrow(cs).replace(true)) {
                 panic!("InterruptExecutor::start() called multiple times on the same executor.");
             }
 
@@ -222,10 +218,10 @@ mod interrupt {
         /// This returns a [`SendSpawner`] you can use to spawn tasks on this
         /// executor.
         ///
-        /// This MUST only be called on an executor that has already been spawned.
+        /// This MUST only be called on an executor that has already been started.
         /// The function will panic otherwise.
         pub fn spawner(&'static self) -> crate::SendSpawner {
-            if !self.started.load(Ordering::Acquire) {
+            if !critical_section::with(|cs| self.started.borrow(cs).get()) {
                 panic!("InterruptExecutor::spawner() called on uninitialized executor.");
             }
             let executor = unsafe { (&*self.executor.get()).assume_init_ref() };

embassy-executor/src/arch/riscv32.rs

@@ -7,9 +7,8 @@ pub use thread::*;
 mod thread {
     use core::marker::PhantomData;
 
-    use atomic_polyfill::{AtomicBool, Ordering};
-    #[cfg(feature = "nightly")]
     pub use embassy_macros::main_riscv as main;
+    use portable_atomic::{AtomicBool, Ordering};
 
     use crate::{raw, Spawner};
 

embassy-executor/src/arch/std.rs

@@ -8,7 +8,6 @@ mod thread {
     use std::marker::PhantomData;
     use std::sync::{Condvar, Mutex};
 
-    #[cfg(feature = "nightly")]
     pub use embassy_macros::main_std as main;
 
     use crate::{raw, Spawner};

embassy-executor/src/arch/wasm.rs

@@ -8,7 +8,6 @@ mod thread {
 
     use core::marker::PhantomData;
 
-    #[cfg(feature = "nightly")]
     pub use embassy_macros::main_wasm as main;
     use js_sys::Promise;
     use wasm_bindgen::prelude::*;

embassy-executor/src/arch/xtensa.rs

@@ -8,6 +8,8 @@ mod thread {
     use core::marker::PhantomData;
     use core::sync::atomic::{AtomicBool, Ordering};
 
+    pub use embassy_macros::main_riscv as main;
+
     use crate::{raw, Spawner};
 
     /// global atomic used to keep track of whether there is work to do since sev() is not available on Xtensa

embassy-executor/src/lib.rs

@@ -1,5 +1,5 @@
 #![cfg_attr(not(any(feature = "arch-std", feature = "arch-wasm")), no_std)]
-#![cfg_attr(all(feature = "nightly", feature = "arch-xtensa"), feature(asm_experimental_arch))]
+#![cfg_attr(feature = "arch-xtensa", feature(asm_experimental_arch))]
 #![allow(clippy::new_without_default)]
 #![doc = include_str!("../README.md")]
 #![warn(missing_docs)]
@@ -7,7 +7,6 @@
 // This mod MUST go first, so that the others see its macros.
 pub(crate) mod fmt;
 
-#[cfg(feature = "nightly")]
 pub use embassy_macros::task;
 
 macro_rules! check_at_most_one {
@@ -41,28 +40,101 @@ pub mod raw;
 mod spawner;
 pub use spawner::*;
 
+mod config {
+    #![allow(unused)]
+    include!(concat!(env!("OUT_DIR"), "/config.rs"));
+}
+
 /// Implementation details for embassy macros.
 /// Do not use. Used for macros and HALs only. Not covered by semver guarantees.
 #[doc(hidden)]
+#[cfg(not(feature = "nightly"))]
 pub mod _export {
-    #[cfg(feature = "rtos-trace")]
-    pub use rtos_trace::trace;
+    use core::alloc::Layout;
+    use core::cell::{Cell, UnsafeCell};
+    use core::future::Future;
+    use core::mem::MaybeUninit;
+    use core::ptr::null_mut;
 
-    /// Expands the given block of code when `embassy-executor` is compiled with
-    /// the `rtos-trace-interrupt` feature.
-    #[doc(hidden)]
-    #[macro_export]
-    #[cfg(feature = "rtos-trace-interrupt")]
-    macro_rules! rtos_trace_interrupt {
-        ($($tt:tt)*) => { $($tt)* };
+    use critical_section::{CriticalSection, Mutex};
+
+    use crate::raw::TaskPool;
+
+    struct Arena<const N: usize> {
+        buf: UnsafeCell<MaybeUninit<[u8; N]>>,
+        ptr: Mutex<Cell<*mut u8>>,
     }
 
-    /// Does not expand the given block of code when `embassy-executor` is
-    /// compiled without the `rtos-trace-interrupt` feature.
-    #[doc(hidden)]
-    #[macro_export]
-    #[cfg(not(feature = "rtos-trace-interrupt"))]
-    macro_rules! rtos_trace_interrupt {
-        ($($tt:tt)*) => {};
+    unsafe impl<const N: usize> Sync for Arena<N> {}
+    unsafe impl<const N: usize> Send for Arena<N> {}
+
+    impl<const N: usize> Arena<N> {
+        const fn new() -> Self {
+            Self {
+                buf: UnsafeCell::new(MaybeUninit::uninit()),
+                ptr: Mutex::new(Cell::new(null_mut())),
+            }
+        }
+
+        fn alloc<T>(&'static self, cs: CriticalSection) -> &'static mut MaybeUninit<T> {
+            let layout = Layout::new::<T>();
+
+            let start = self.buf.get().cast::<u8>();
+            let end = unsafe { start.add(N) };
+
+            let mut ptr = self.ptr.borrow(cs).get();
+            if ptr.is_null() {
+                ptr = self.buf.get().cast::<u8>();
+            }
+
+            let bytes_left = (end as usize) - (ptr as usize);
+            let align_offset = (ptr as usize).next_multiple_of(layout.align()) - (ptr as usize);
+
+            if align_offset + layout.size() > bytes_left {
+                panic!("embassy-executor: task arena is full. You must increase the arena size, see the documentation for details: https://docs.embassy.dev/embassy-executor/");
+            }
+
+            let res = unsafe { ptr.add(align_offset) };
+            let ptr = unsafe { ptr.add(align_offset + layout.size()) };
+
+            self.ptr.borrow(cs).set(ptr);
+
+            unsafe { &mut *(res as *mut MaybeUninit<T>) }
+        }
+    }
+
+    static ARENA: Arena<{ crate::config::TASK_ARENA_SIZE }> = Arena::new();
+
+    pub struct TaskPoolRef {
+        // type-erased `&'static mut TaskPool<F, N>`
+        // Needed because statics can't have generics.
+        ptr: Mutex<Cell<*mut ()>>,
+    }
+    unsafe impl Sync for TaskPoolRef {}
+    unsafe impl Send for TaskPoolRef {}
+
+    impl TaskPoolRef {
+        pub const fn new() -> Self {
+            Self {
+                ptr: Mutex::new(Cell::new(null_mut())),
+            }
+        }
+
+        /// Get the pool for this ref, allocating it from the arena the first time.
+        ///
+        /// safety: for a given TaskPoolRef instance, must always call with the exact
+        /// same generic params.
+        pub unsafe fn get<F: Future, const N: usize>(&'static self) -> &'static TaskPool<F, N> {
+            critical_section::with(|cs| {
+                let ptr = self.ptr.borrow(cs);
+                if ptr.get().is_null() {
+                    let pool = ARENA.alloc::<TaskPool<F, N>>(cs);
+                    pool.write(TaskPool::new());
+                    ptr.set(pool as *mut _ as _);
+                }
+
+                unsafe { &*(ptr.get() as *const _) }
+            })
+        }
     }
 }

embassy-executor/src/raw/mod.rs

@@ -7,7 +7,15 @@
 //! Using this module requires respecting subtle safety contracts. If you can, prefer using the safe
 //! [executor wrappers](crate::Executor) and the [`embassy_executor::task`](embassy_macros::task) macro, which are fully safe.
 
+#[cfg_attr(target_has_atomic = "ptr", path = "run_queue_atomics.rs")]
+#[cfg_attr(not(target_has_atomic = "ptr"), path = "run_queue_critical_section.rs")]
 mod run_queue;
+
+#[cfg_attr(all(cortex_m, target_has_atomic = "8"), path = "state_atomics_arm.rs")]
+#[cfg_attr(all(not(cortex_m), target_has_atomic = "8"), path = "state_atomics.rs")]
+#[cfg_attr(not(target_has_atomic = "8"), path = "state_critical_section.rs")]
+mod state;
+
 #[cfg(feature = "integrated-timers")]
 mod timer_queue;
 pub(crate) mod util;
@@ -21,7 +29,6 @@ use core::pin::Pin;
 use core::ptr::NonNull;
 use core::task::{Context, Poll};
 
-use atomic_polyfill::{AtomicU32, Ordering};
 #[cfg(feature = "integrated-timers")]
 use embassy_time::driver::{self, AlarmHandle};
 #[cfg(feature = "integrated-timers")]
@@ -30,21 +37,14 @@ use embassy_time::Instant;
 use rtos_trace::trace;
 
 use self::run_queue::{RunQueue, RunQueueItem};
+use self::state::State;
 use self::util::{SyncUnsafeCell, UninitCell};
 pub use self::waker::task_from_waker;
 use super::SpawnToken;
 
-/// Task is spawned (has a future)
-pub(crate) const STATE_SPAWNED: u32 = 1 << 0;
-/// Task is in the executor run queue
-pub(crate) const STATE_RUN_QUEUED: u32 = 1 << 1;
-/// Task is in the executor timer queue
-#[cfg(feature = "integrated-timers")]
-pub(crate) const STATE_TIMER_QUEUED: u32 = 1 << 2;
-
 /// Raw task header for use in task pointers.
 pub(crate) struct TaskHeader {
-    pub(crate) state: AtomicU32,
+    pub(crate) state: State,
     pub(crate) run_queue_item: RunQueueItem,
     pub(crate) executor: SyncUnsafeCell<Option<&'static SyncExecutor>>,
     poll_fn: SyncUnsafeCell<Option<unsafe fn(TaskRef)>>,
@@ -116,7 +116,7 @@ impl<F: Future + 'static> TaskStorage<F> {
     pub const fn new() -> Self {
         Self {
             raw: TaskHeader {
-                state: AtomicU32::new(0),
+                state: State::new(),
                 run_queue_item: RunQueueItem::new(),
                 executor: SyncUnsafeCell::new(None),
                 // Note: this is lazily initialized so that a static `TaskStorage` will go in `.bss`
@@ -161,7 +161,7 @@ impl<F: Future + 'static> TaskStorage<F> {
         match future.poll(&mut cx) {
             Poll::Ready(_) => {
                 this.future.drop_in_place();
-                this.raw.state.fetch_and(!STATE_SPAWNED, Ordering::AcqRel);
+                this.raw.state.despawn();
 
                 #[cfg(feature = "integrated-timers")]
                 this.raw.expires_at.set(Instant::MAX);
@@ -193,11 +193,7 @@ impl<F: Future + 'static> AvailableTask<F> {
     ///
     /// This function returns `None` if a task has already been spawned and has not finished running.
     pub fn claim(task: &'static TaskStorage<F>) -> Option<Self> {
-        task.raw
-            .state
-            .compare_exchange(0, STATE_SPAWNED | STATE_RUN_QUEUED, Ordering::AcqRel, Ordering::Acquire)
-            .ok()
-            .map(|_| Self { task })
+        task.raw.state.spawn().then(|| Self { task })
     }
 
     fn initialize_impl<S>(self, future: impl FnOnce() -> F) -> SpawnToken<S> {
@@ -394,8 +390,7 @@ impl SyncExecutor {
                 #[cfg(feature = "integrated-timers")]
                 task.expires_at.set(Instant::MAX);
 
-                let state = task.state.fetch_and(!STATE_RUN_QUEUED, Ordering::AcqRel);
-                if state & STATE_SPAWNED == 0 {
+                if !task.state.run_dequeue() {
                     // If task is not running, ignore it. This can happen in the following scenario:
                     //   - Task gets dequeued, poll starts
                     //   - While task is being polled, it gets woken. It gets placed in the queue.
@@ -546,18 +541,7 @@ impl Executor {
 /// You can obtain a `TaskRef` from a `Waker` using [`task_from_waker`].
 pub fn wake_task(task: TaskRef) {
     let header = task.header();
-
-    let res = header.state.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |state| {
-        // If already scheduled, or if not started,
-        if (state & STATE_RUN_QUEUED != 0) || (state & STATE_SPAWNED == 0) {
-            None
-        } else {
-            // Mark it as scheduled
-            Some(state | STATE_RUN_QUEUED)
-        }
-    });
-
-    if res.is_ok() {
+    if header.state.run_enqueue() {
         // We have just marked the task as scheduled, so enqueue it.
         unsafe {
             let executor = header.executor.get().unwrap_unchecked();
@@ -571,18 +555,7 @@ pub fn wake_task(task: TaskRef) {
 /// You can obtain a `TaskRef` from a `Waker` using [`task_from_waker`].
 pub fn wake_task_no_pend(task: TaskRef) {
     let header = task.header();
-
-    let res = header.state.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |state| {
-        // If already scheduled, or if not started,
-        if (state & STATE_RUN_QUEUED != 0) || (state & STATE_SPAWNED == 0) {
-            None
-        } else {
-            // Mark it as scheduled
-            Some(state | STATE_RUN_QUEUED)
-        }
-    });
-
-    if res.is_ok() {
+    if header.state.run_enqueue() {
         // We have just marked the task as scheduled, so enqueue it.
         unsafe {
             let executor = header.executor.get().unwrap_unchecked();

embassy-executor/src/raw/run_queue_atomics.rs

@@ -1,7 +1,6 @@
 use core::ptr;
 use core::ptr::NonNull;
-
-use atomic_polyfill::{AtomicPtr, Ordering};
+use core::sync::atomic::{AtomicPtr, Ordering};
 
 use super::{TaskHeader, TaskRef};
 use crate::raw::util::SyncUnsafeCell;

embassy-executor/src/raw/run_queue_critical_section.rs

@@ -0,0 +1,75 @@
+use core::cell::Cell;
+
+use critical_section::{CriticalSection, Mutex};
+
+use super::TaskRef;
+
+pub(crate) struct RunQueueItem {
+    next: Mutex<Cell<Option<TaskRef>>>,
+}
+
+impl RunQueueItem {
+    pub const fn new() -> Self {
+        Self {
+            next: Mutex::new(Cell::new(None)),
+        }
+    }
+}
+
+/// Atomic task queue using a very, very simple lock-free linked-list queue:
+///
+/// To enqueue a task, task.next is set to the old head, and head is atomically set to task.
+///
+/// Dequeuing is done in batches: the queue is emptied by atomically replacing head with
+/// null. Then the batch is iterated following the next pointers until null is reached.
+///
+/// Note that batches will be iterated in the reverse order as they were enqueued. This is OK
+/// for our purposes: it can't create fairness problems since the next batch won't run until the
+/// current batch is completely processed, so even if a task enqueues itself instantly (for example
+/// by waking its own waker) can't prevent other tasks from running.
+pub(crate) struct RunQueue {
+    head: Mutex<Cell<Option<TaskRef>>>,
+}
+
+impl RunQueue {
+    pub const fn new() -> Self {
+        Self {
+            head: Mutex::new(Cell::new(None)),
+        }
+    }
+
+    /// Enqueues an item. Returns true if the queue was empty.
+    ///
+    /// # Safety
+    ///
+    /// `item` must NOT be already enqueued in any queue.
+    #[inline(always)]
+    pub(crate) unsafe fn enqueue(&self, task: TaskRef) -> bool {
+        critical_section::with(|cs| {
+            let prev = self.head.borrow(cs).replace(Some(task));
+            task.header().run_queue_item.next.borrow(cs).set(prev);
+
+            prev.is_none()
+        })
+    }
+
+    /// Empty the queue, then call `on_task` for each task that was in the queue.
+    /// NOTE: It is OK for `on_task` to enqueue more tasks. In this case they're left in the queue
+    /// and will be processed by the *next* call to `dequeue_all`, *not* the current one.
+    pub(crate) fn dequeue_all(&self, on_task: impl Fn(TaskRef)) {
+        // Atomically empty the queue.
+        let mut next = critical_section::with(|cs| self.head.borrow(cs).take());
+
+        // Iterate the linked list of tasks that were previously in the queue.
+        while let Some(task) = next {
+            // If the task re-enqueues itself, the `next` pointer will get overwritten.
+            // Therefore, first read the next pointer, and only then process the task.
+
+            // safety: we know if the task is enqueued, no one else will touch the `next` pointer.
+            let cs = unsafe { CriticalSection::new() };
+            next = task.header().run_queue_item.next.borrow(cs).get();
+
+            on_task(task);
+        }
+    }
+}

embassy-executor/src/raw/state_atomics.rs

@@ -0,0 +1,73 @@
+use core::sync::atomic::{AtomicU32, Ordering};
+
+/// Task is spawned (has a future)
+pub(crate) const STATE_SPAWNED: u32 = 1 << 0;
+/// Task is in the executor run queue
+pub(crate) const STATE_RUN_QUEUED: u32 = 1 << 1;
+/// Task is in the executor timer queue
+#[cfg(feature = "integrated-timers")]
+pub(crate) const STATE_TIMER_QUEUED: u32 = 1 << 2;
+
+pub(crate) struct State {
+    state: AtomicU32,
+}
+
+impl State {
+    pub const fn new() -> State {
+        Self {
+            state: AtomicU32::new(0),
+        }
+    }
+
+    /// If task is idle, mark it as spawned + run_queued and return true.
+    #[inline(always)]
+    pub fn spawn(&self) -> bool {
+        self.state
+            .compare_exchange(0, STATE_SPAWNED | STATE_RUN_QUEUED, Ordering::AcqRel, Ordering::Acquire)
+            .is_ok()
+    }
+
+    /// Unmark the task as spawned.
+    #[inline(always)]
+    pub fn despawn(&self) {
+        self.state.fetch_and(!STATE_SPAWNED, Ordering::AcqRel);
+    }
+
+    /// Mark the task as run-queued if it's spawned and isn't already run-queued. Return true on success.
+    #[inline(always)]
+    pub fn run_enqueue(&self) -> bool {
+        self.state
+            .fetch_update(Ordering::SeqCst, Ordering::SeqCst, |state| {
+                // If already scheduled, or if not started,
+                if (state & STATE_RUN_QUEUED != 0) || (state & STATE_SPAWNED == 0) {
+                    None
+                } else {
+                    // Mark it as scheduled
+                    Some(state | STATE_RUN_QUEUED)
+                }
+            })
+            .is_ok()
+    }
+
+    /// Unmark the task as run-queued. Return whether the task is spawned.
+    #[inline(always)]
+    pub fn run_dequeue(&self) -> bool {
+        let state = self.state.fetch_and(!STATE_RUN_QUEUED, Ordering::AcqRel);
+        state & STATE_SPAWNED != 0
+    }
+
+    /// Mark the task as timer-queued. Return whether it was newly queued (i.e. not queued before)
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_enqueue(&self) -> bool {
+        let old_state = self.state.fetch_or(STATE_TIMER_QUEUED, Ordering::AcqRel);
+        old_state & STATE_TIMER_QUEUED == 0
+    }
+
+    /// Unmark the task as timer-queued.
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_dequeue(&self) {
+        self.state.fetch_and(!STATE_TIMER_QUEUED, Ordering::AcqRel);
+    }
+}

embassy-executor/src/raw/state_atomics_arm.rs

@@ -0,0 +1,103 @@
+use core::arch::asm;
+use core::sync::atomic::{compiler_fence, AtomicBool, AtomicU32, Ordering};
+
+// Must be kept in sync with the layout of `State`!
+pub(crate) const STATE_SPAWNED: u32 = 1 << 0;
+pub(crate) const STATE_RUN_QUEUED: u32 = 1 << 8;
+
+#[repr(C, align(4))]
+pub(crate) struct State {
+    /// Task is spawned (has a future)
+    spawned: AtomicBool,
+    /// Task is in the executor run queue
+    run_queued: AtomicBool,
+    /// Task is in the executor timer queue
+    timer_queued: AtomicBool,
+    pad: AtomicBool,
+}
+
+impl State {
+    pub const fn new() -> State {
+        Self {
+            spawned: AtomicBool::new(false),
+            run_queued: AtomicBool::new(false),
+            timer_queued: AtomicBool::new(false),
+            pad: AtomicBool::new(false),
+        }
+    }
+
+    fn as_u32(&self) -> &AtomicU32 {
+        unsafe { &*(self as *const _ as *const AtomicU32) }
+    }
+
+    /// If task is idle, mark it as spawned + run_queued and return true.
+    #[inline(always)]
+    pub fn spawn(&self) -> bool {
+        compiler_fence(Ordering::Release);
+        let r = self
+            .as_u32()
+            .compare_exchange(
+                0,
+                STATE_SPAWNED | STATE_RUN_QUEUED,
+                Ordering::Relaxed,
+                Ordering::Relaxed,
+            )
+            .is_ok();
+        compiler_fence(Ordering::Acquire);
+        r
+    }
+
+    /// Unmark the task as spawned.
+    #[inline(always)]
+    pub fn despawn(&self) {
+        compiler_fence(Ordering::Release);
+        self.spawned.store(false, Ordering::Relaxed);
+    }
+
+    /// Mark the task as run-queued if it's spawned and isn't already run-queued. Return true on success.
+    #[inline(always)]
+    pub fn run_enqueue(&self) -> bool {
+        unsafe {
+            loop {
+                let state: u32;
+                asm!("ldrex {}, [{}]", out(reg) state, in(reg) self, options(nostack));
+
+                if (state & STATE_RUN_QUEUED != 0) || (state & STATE_SPAWNED == 0) {
+                    asm!("clrex", options(nomem, nostack));
+                    return false;
+                }
+
+                let outcome: usize;
+                let new_state = state | STATE_RUN_QUEUED;
+                asm!("strex {}, {}, [{}]", out(reg) outcome, in(reg) new_state, in(reg) self, options(nostack));
+                if outcome == 0 {
+                    return true;
+                }
+            }
+        }
+    }
+
+    /// Unmark the task as run-queued. Return whether the task is spawned.
+    #[inline(always)]
+    pub fn run_dequeue(&self) -> bool {
+        compiler_fence(Ordering::Release);
+
+        let r = self.spawned.load(Ordering::Relaxed);
+        self.run_queued.store(false, Ordering::Relaxed);
+        r
+    }
+
+    /// Mark the task as timer-queued. Return whether it was newly queued (i.e. not queued before)
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_enqueue(&self) -> bool {
+        !self.timer_queued.swap(true, Ordering::Relaxed)
+    }
+
+    /// Unmark the task as timer-queued.
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_dequeue(&self) {
+        self.timer_queued.store(false, Ordering::Relaxed);
+    }
+}

embassy-executor/src/raw/state_critical_section.rs

@@ -0,0 +1,93 @@
+use core::cell::Cell;
+
+use critical_section::Mutex;
+
+/// Task is spawned (has a future)
+pub(crate) const STATE_SPAWNED: u32 = 1 << 0;
+/// Task is in the executor run queue
+pub(crate) const STATE_RUN_QUEUED: u32 = 1 << 1;
+/// Task is in the executor timer queue
+#[cfg(feature = "integrated-timers")]
+pub(crate) const STATE_TIMER_QUEUED: u32 = 1 << 2;
+
+pub(crate) struct State {
+    state: Mutex<Cell<u32>>,
+}
+
+impl State {
+    pub const fn new() -> State {
+        Self {
+            state: Mutex::new(Cell::new(0)),
+        }
+    }
+
+    fn update<R>(&self, f: impl FnOnce(&mut u32) -> R) -> R {
+        critical_section::with(|cs| {
+            let s = self.state.borrow(cs);
+            let mut val = s.get();
+            let r = f(&mut val);
+            s.set(val);
+            r
+        })
+    }
+
+    /// If task is idle, mark it as spawned + run_queued and return true.
+    #[inline(always)]
+    pub fn spawn(&self) -> bool {
+        self.update(|s| {
+            if *s == 0 {
+                *s = STATE_SPAWNED | STATE_RUN_QUEUED;
+                true
+            } else {
+                false
+            }
+        })
+    }
+
+    /// Unmark the task as spawned.
+    #[inline(always)]
+    pub fn despawn(&self) {
+        self.update(|s| *s &= !STATE_SPAWNED);
+    }
+
+    /// Mark the task as run-queued if it's spawned and isn't already run-queued. Return true on success.
+    #[inline(always)]
+    pub fn run_enqueue(&self) -> bool {
+        self.update(|s| {
+            if (*s & STATE_RUN_QUEUED != 0) || (*s & STATE_SPAWNED == 0) {
+                false
+            } else {
+                *s |= STATE_RUN_QUEUED;
+                true
+            }
+        })
+    }
+
+    /// Unmark the task as run-queued. Return whether the task is spawned.
+    #[inline(always)]
+    pub fn run_dequeue(&self) -> bool {
+        self.update(|s| {
+            let ok = *s & STATE_SPAWNED != 0;
+            *s &= !STATE_RUN_QUEUED;
+            ok
+        })
+    }
+
+    /// Mark the task as timer-queued. Return whether it was newly queued (i.e. not queued before)
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_enqueue(&self) -> bool {
+        self.update(|s| {
+            let ok = *s & STATE_TIMER_QUEUED == 0;
+            *s |= STATE_TIMER_QUEUED;
+            ok
+        })
+    }
+
+    /// Unmark the task as timer-queued.
+    #[cfg(feature = "integrated-timers")]
+    #[inline(always)]
+    pub fn timer_dequeue(&self) {
+        self.update(|s| *s &= !STATE_TIMER_QUEUED);
+    }
+}

embassy-executor/src/raw/timer_queue.rs

@@ -1,9 +1,8 @@
 use core::cmp::min;
 
-use atomic_polyfill::Ordering;
 use embassy_time::Instant;
 
-use super::{TaskRef, STATE_TIMER_QUEUED};
+use super::TaskRef;
 use crate::raw::util::SyncUnsafeCell;
 
 pub(crate) struct TimerQueueItem {
@@ -32,10 +31,7 @@ impl TimerQueue {
     pub(crate) unsafe fn update(&self, p: TaskRef) {
         let task = p.header();
         if task.expires_at.get() != Instant::MAX {
-            let old_state = task.state.fetch_or(STATE_TIMER_QUEUED, Ordering::AcqRel);
-            let is_new = old_state & STATE_TIMER_QUEUED == 0;
-
-            if is_new {
+            if task.state.timer_enqueue() {
                 task.timer_queue_item.next.set(self.head.get());
                 self.head.set(Some(p));
             }
@@ -75,7 +71,7 @@ impl TimerQueue {
             } else {
                 // Remove it
                 prev.set(task.timer_queue_item.next.get());
-                task.state.fetch_and(!STATE_TIMER_QUEUED, Ordering::AcqRel);
+                task.state.timer_dequeue();
             }
         }
     }

embassy-executor/tests/test.rs

@@ -0,0 +1,137 @@
+#![cfg_attr(feature = "nightly", feature(type_alias_impl_trait))]
+
+use std::boxed::Box;
+use std::future::poll_fn;
+use std::sync::{Arc, Mutex};
+use std::task::Poll;
+
+use embassy_executor::raw::Executor;
+use embassy_executor::task;
+
+#[export_name = "__pender"]
+fn __pender(context: *mut ()) {
+    unsafe {
+        let trace = &*(context as *const Trace);
+        trace.push("pend");
+    }
+}
+
+#[derive(Clone)]
+struct Trace {
+    trace: Arc<Mutex<Vec<&'static str>>>,
+}
+
+impl Trace {
+    fn new() -> Self {
+        Self {
+            trace: Arc::new(Mutex::new(Vec::new())),
+        }
+    }
+    fn push(&self, value: &'static str) {
+        self.trace.lock().unwrap().push(value)
+    }
+
+    fn get(&self) -> Vec<&'static str> {
+        self.trace.lock().unwrap().clone()
+    }
+}
+
+fn setup() -> (&'static Executor, Trace) {
+    let trace = Trace::new();
+    let context = Box::leak(Box::new(trace.clone())) as *mut _ as *mut ();
+    let executor = &*Box::leak(Box::new(Executor::new(context)));
+    (executor, trace)
+}
+
+#[test]
+fn executor_noop() {
+    let (executor, trace) = setup();
+    unsafe { executor.poll() };
+    assert!(trace.get().is_empty())
+}
+
+#[test]
+fn executor_task() {
+    #[task]
+    async fn task1(trace: Trace) {
+        trace.push("poll task1")
+    }
+
+    let (executor, trace) = setup();
+    executor.spawner().spawn(task1(trace.clone())).unwrap();
+
+    unsafe { executor.poll() };
+    unsafe { executor.poll() };
+
+    assert_eq!(
+        trace.get(),
+        &[
+            "pend",       // spawning a task pends the executor
+            "poll task1", // poll only once.
+        ]
+    )
+}
+
+#[test]
+fn executor_task_self_wake() {
+    #[task]
+    async fn task1(trace: Trace) {
+        poll_fn(|cx| {
+            trace.push("poll task1");
+            cx.waker().wake_by_ref();
+            Poll::Pending
+        })
+        .await
+    }
+
+    let (executor, trace) = setup();
+    executor.spawner().spawn(task1(trace.clone())).unwrap();
+
+    unsafe { executor.poll() };
+    unsafe { executor.poll() };
+
+    assert_eq!(
+        trace.get(),
+        &[
+            "pend",       // spawning a task pends the executor
+            "poll task1", //
+            "pend",       // task self-wakes
+            "poll task1", //
+            "pend",       // task self-wakes
+        ]
+    )
+}
+
+#[test]
+fn executor_task_self_wake_twice() {
+    #[task]
+    async fn task1(trace: Trace) {
+        poll_fn(|cx| {
+            trace.push("poll task1");
+            cx.waker().wake_by_ref();
+            trace.push("poll task1 wake 2");
+            cx.waker().wake_by_ref();
+            Poll::Pending
+        })
+        .await
+    }
+
+    let (executor, trace) = setup();
+    executor.spawner().spawn(task1(trace.clone())).unwrap();
+
+    unsafe { executor.poll() };
+    unsafe { executor.poll() };
+
+    assert_eq!(
+        trace.get(),
+        &[
+            "pend",              // spawning a task pends the executor
+            "poll task1",        //
+            "pend",              // task self-wakes
+            "poll task1 wake 2", // task self-wakes again, shouldn't pend
+            "poll task1",        //
+            "pend",              // task self-wakes
+            "poll task1 wake 2", // task self-wakes again, shouldn't pend
+        ]
+    )
+}

embassy-futures/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "embassy-futures"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 description = "no-std, no-alloc utilities for working with futures"
 repository = "https://github.com/embassy-rs/embassy"

embassy-macros/Cargo.toml

@@ -21,5 +21,4 @@ proc-macro2 = "1.0.29"
 proc-macro = true
 
 [features]
-# Enabling this cause interrupt::take! to require embassy-executor
-rtos-trace-interrupt = []
+nightly = []

embassy-macros/src/macros/task.rs

@@ -79,6 +79,7 @@ pub fn run(args: &[NestedMeta], f: syn::ItemFn) -> Result<TokenStream, TokenStre
     task_inner.vis = syn::Visibility::Inherited;
     task_inner.sig.ident = task_inner_ident.clone();
 
+    #[cfg(feature = "nightly")]
     let mut task_outer: ItemFn = parse_quote! {
         #visibility fn #task_ident(#fargs) -> ::embassy_executor::SpawnToken<impl Sized> {
             type Fut = impl ::core::future::Future + 'static;
@@ -87,6 +88,14 @@ pub fn run(args: &[NestedMeta], f: syn::ItemFn) -> Result<TokenStream, TokenStre
             unsafe { POOL._spawn_async_fn(move || #task_inner_ident(#(#arg_names,)*)) }
         }
     };
+    #[cfg(not(feature = "nightly"))]
+    let mut task_outer: ItemFn = parse_quote! {
+        #visibility fn #task_ident(#fargs) -> ::embassy_executor::SpawnToken<impl Sized> {
+            const POOL_SIZE: usize = #pool_size;
+            static POOL: ::embassy_executor::_export::TaskPoolRef = ::embassy_executor::_export::TaskPoolRef::new();
+            unsafe { POOL.get::<_, POOL_SIZE>()._spawn_async_fn(move || #task_inner_ident(#(#arg_names,)*)) }
+        }
+    };
 
     task_outer.attrs.append(&mut task_inner.attrs.clone());
 

embassy-net/CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 
 - Avoid never resolving `TcpIo::read` when the output buffer is empty.
+- Update to `smoltcp` git.
+- Forward constants from `smoltcp` in DNS query results so changing DNS result size in `smoltcp` properly propagates.
 
 ## 0.2.1 - 2023-10-31
 

embassy-net/Cargo.toml

@@ -25,7 +25,7 @@ features = ["nightly", "defmt", "tcp", "udp", "dns", "dhcpv4", "proto-ipv6", "me
 default = []
 std = []
 
-defmt = ["dep:defmt", "smoltcp/defmt", "embassy-net-driver/defmt"]
+defmt = ["dep:defmt", "smoltcp/defmt", "embassy-net-driver/defmt", "heapless/defmt-03"]
 
 nightly = ["dep:embedded-io-async", "dep:embedded-nal-async"]
 
@@ -46,7 +46,7 @@ igmp = ["smoltcp/proto-igmp"]
 defmt = { version = "0.3", optional = true }
 log = { version = "0.4.14", optional = true }
 
-smoltcp = { git = "https://github.com/smoltcp-rs/smoltcp", rev = "9b791ae3057e10f7afcb70c67deb5daf714293a9", default-features = false, features = [
+smoltcp = { git = "https://github.com/smoltcp-rs/smoltcp.git", rev = "b57e2f9e70e82a13f31d5ea17e55232c11cc2b2d", default-features = false, features = [
   "socket",
   "async",
 ] }

embassy-net/src/dns.rs

@@ -63,7 +63,11 @@ where
     }
 
     /// Make a query for a given name and return the corresponding IP addresses.
-    pub async fn query(&self, name: &str, qtype: DnsQueryType) -> Result<Vec<IpAddress, 1>, Error> {
+    pub async fn query(
+        &self,
+        name: &str,
+        qtype: DnsQueryType,
+    ) -> Result<Vec<IpAddress, { smoltcp::config::DNS_MAX_RESULT_COUNT }>, Error> {
         self.stack.dns_query(name, qtype).await
     }
 }

embassy-net/src/lib.rs

@@ -494,7 +494,11 @@ impl<D: Driver> Stack<D> {
 
     /// Make a query for a given name and return the corresponding IP addresses.
     #[cfg(feature = "dns")]
-    pub async fn dns_query(&self, name: &str, qtype: dns::DnsQueryType) -> Result<Vec<IpAddress, 1>, dns::Error> {
+    pub async fn dns_query(
+        &self,
+        name: &str,
+        qtype: dns::DnsQueryType,
+    ) -> Result<Vec<IpAddress, { smoltcp::config::DNS_MAX_RESULT_COUNT }>, dns::Error> {
         // For A and AAAA queries we try detect whether `name` is just an IP address
         match qtype {
             #[cfg(feature = "proto-ipv4")]
@@ -612,9 +616,11 @@ impl<D: Driver> Stack<D> {
         let addr = addr.into();
 
         self.with_mut(|s, i| {
+            let (_hardware_addr, medium) = to_smoltcp_hardware_address(i.device.hardware_address());
             let mut smoldev = DriverAdapter {
                 cx: Some(cx),
                 inner: &mut i.device,
+                medium,
             };
 
             match s
@@ -649,9 +655,11 @@ impl<D: Driver> Stack<D> {
         let addr = addr.into();
 
         self.with_mut(|s, i| {
+            let (_hardware_addr, medium) = to_smoltcp_hardware_address(i.device.hardware_address());
             let mut smoldev = DriverAdapter {
                 cx: Some(cx),
                 inner: &mut i.device,
+                medium,
             };
 
             match s

embassy-nrf/src/buffered_uarte.rs

@@ -12,7 +12,7 @@ use core::cmp::min;
 use core::future::poll_fn;
 use core::marker::PhantomData;
 use core::slice;
-use core::sync::atomic::{compiler_fence, AtomicU8, AtomicUsize, Ordering};
+use core::sync::atomic::{compiler_fence, AtomicBool, AtomicU8, AtomicUsize, Ordering};
 use core::task::Poll;
 
 use embassy_hal_internal::atomic_ring_buffer::RingBuffer;
@@ -41,7 +41,9 @@ mod sealed {
 
         pub rx_waker: AtomicWaker,
         pub rx_buf: RingBuffer,
-        pub rx_bufs: AtomicU8,
+        pub rx_started: AtomicBool,
+        pub rx_started_count: AtomicU8,
+        pub rx_ended_count: AtomicU8,
         pub rx_ppi_ch: AtomicU8,
     }
 }
@@ -65,7 +67,9 @@ impl State {
 
             rx_waker: AtomicWaker::new(),
             rx_buf: RingBuffer::new(),
-            rx_bufs: AtomicU8::new(0),
+            rx_started: AtomicBool::new(false),
+            rx_started_count: AtomicU8::new(0),
+            rx_ended_count: AtomicU8::new(0),
             rx_ppi_ch: AtomicU8::new(0),
         }
     }
@@ -104,28 +108,20 @@ impl<U: UarteInstance> interrupt::typelevel::Handler<U::Interrupt> for Interrupt
             s.rx_waker.wake();
         }
 
-        // If not RXing, start.
-        if s.rx_bufs.load(Ordering::Relaxed) == 0 {
-            let (ptr, len) = rx.push_buf();
-            if len >= half_len {
-                //trace!("  irq_rx: starting {:?}", half_len);
-                s.rx_bufs.store(1, Ordering::Relaxed);
+        if r.events_endrx.read().bits() != 0 {
+            //trace!("  irq_rx: endrx");
+            r.events_endrx.reset();
 
-                // Set up the DMA read
-                r.rxd.ptr.write(|w| unsafe { w.ptr().bits(ptr as u32) });
-                r.rxd.maxcnt.write(|w| unsafe { w.maxcnt().bits(half_len as _) });
-
-                // Start UARTE Receive transaction
-                r.tasks_startrx.write(|w| unsafe { w.bits(1) });
-                rx.push_done(half_len);
-                r.intenset.write(|w| w.rxstarted().set());
-            }
+            let val = s.rx_ended_count.load(Ordering::Relaxed);
+            s.rx_ended_count.store(val.wrapping_add(1), Ordering::Relaxed);
         }
 
-        if r.events_rxstarted.read().bits() != 0 {
+        if r.events_rxstarted.read().bits() != 0 || !s.rx_started.load(Ordering::Relaxed) {
             //trace!("  irq_rx: rxstarted");
             let (ptr, len) = rx.push_buf();
             if len >= half_len {
+                r.events_rxstarted.reset();
+
                 //trace!("  irq_rx: starting second {:?}", half_len);
 
                 // Set up the DMA read
@@ -134,11 +130,50 @@ impl<U: UarteInstance> interrupt::typelevel::Handler<U::Interrupt> for Interrupt
 
                 let chn = s.rx_ppi_ch.load(Ordering::Relaxed);
 
+                // Enable endrx -> startrx PPI channel.
+                // From this point on, if endrx happens, startrx is automatically fired.
                 ppi::regs().chenset.write(|w| unsafe { w.bits(1 << chn) });
 
+                // It is possible that endrx happened BEFORE enabling the PPI. In this case
+                // the PPI channel doesn't trigger, and we'd hang. We have to detect this
+                // and manually start.
+
+                // check again in case endrx has happened between the last check and now.
+                if r.events_endrx.read().bits() != 0 {
+                    //trace!("  irq_rx: endrx");
+                    r.events_endrx.reset();
+
+                    let val = s.rx_ended_count.load(Ordering::Relaxed);
+                    s.rx_ended_count.store(val.wrapping_add(1), Ordering::Relaxed);
+                }
+
+                let rx_ended = s.rx_ended_count.load(Ordering::Relaxed);
+                let rx_started = s.rx_started_count.load(Ordering::Relaxed);
+
+                // If we started the same amount of transfers as ended, the last rxend has
+                // already occured.
+                let rxend_happened = rx_started == rx_ended;
+
+                // Check if the PPI channel is still enabled. The PPI channel disables itself
+                // when it fires, so if it's still enabled it hasn't fired.
+                let ppi_ch_enabled = ppi::regs().chen.read().bits() & (1 << chn) != 0;
+
+                // if rxend happened, and the ppi channel hasn't fired yet, the rxend got missed.
+                // this condition also naturally matches if `!started`, needed to kickstart the DMA.
+                if rxend_happened && ppi_ch_enabled {
+                    //trace!("manually starting.");
+
+                    // disable the ppi ch, it's of no use anymore.
+                    ppi::regs().chenclr.write(|w| unsafe { w.bits(1 << chn) });
+
+                    // manually start
+                    r.tasks_startrx.write(|w| unsafe { w.bits(1) });
+                }
+
                 rx.push_done(half_len);
 
-                r.events_rxstarted.reset();
+                s.rx_started_count.store(rx_started.wrapping_add(1), Ordering::Relaxed);
+                s.rx_started.store(true, Ordering::Relaxed);
             } else {
                 //trace!("  irq_rx: rxstarted no buf");
                 r.intenclr.write(|w| w.rxstarted().clear());
@@ -282,6 +317,8 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
 
         let r = U::regs();
 
+        let hwfc = cts.is_some();
+
         rxd.conf().write(|w| w.input().connect().drive().h0h1());
         r.psel.rxd.write(|w| unsafe { w.bits(rxd.psel_bits()) });
 
@@ -303,7 +340,8 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
         // Initialize state
         let s = U::buffered_state();
         s.tx_count.store(0, Ordering::Relaxed);
-        s.rx_bufs.store(0, Ordering::Relaxed);
+        s.rx_started_count.store(0, Ordering::Relaxed);
+        s.rx_ended_count.store(0, Ordering::Relaxed);
         let len = tx_buffer.len();
         unsafe { s.tx_buf.init(tx_buffer.as_mut_ptr(), len) };
         let len = rx_buffer.len();
@@ -311,7 +349,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
 
         // Configure
         r.config.write(|w| {
-            w.hwfc().bit(false);
+            w.hwfc().bit(hwfc);
             w.parity().variant(config.parity);
             w
         });
@@ -333,6 +371,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
             w.endtx().set();
             w.rxstarted().set();
             w.error().set();
+            w.endrx().set();
             w
         });
 

embassy-rp/Cargo.toml

@@ -94,5 +94,5 @@ pio = {version= "0.2.1" }
 rp2040-boot2 = "0.3"
 
 [dev-dependencies]
-embassy-executor = { version = "0.3.1", path = "../embassy-executor", features = ["nightly", "arch-std", "executor-thread"] }
+embassy-executor = { version = "0.3.3", path = "../embassy-executor", features = ["nightly", "arch-std", "executor-thread"] }
 static_cell = { version = "2" }

embassy-stm32-wpan/src/lib.rs

@@ -4,7 +4,6 @@
     any(feature = "ble", feature = "mac"),
     allow(stable_features, unknown_lints, async_fn_in_trait)
 )]
-#![cfg_attr(feature = "mac", feature(type_alias_impl_trait, concat_bytes))]
 
 // This must go FIRST so that all the other modules see its macros.
 mod fmt;

embassy-stm32/Cargo.toml

@@ -39,7 +39,7 @@ embassy-hal-internal = {version = "0.1.0", path = "../embassy-hal-internal", fea
 embassy-embedded-hal = {version = "0.1.0", path = "../embassy-embedded-hal" }
 embassy-net-driver = { version = "0.2.0", path = "../embassy-net-driver" }
 embassy-usb-driver = {version = "0.1.0", path = "../embassy-usb-driver", optional = true }
-embassy-executor = { version = "0.3.1", path = "../embassy-executor", optional = true }
+embassy-executor = { version = "0.3.3", path = "../embassy-executor", optional = true }
 
 embedded-hal-02 = { package = "embedded-hal", version = "0.2.6", features = ["unproven"] }
 embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-rc.1", optional = true}
@@ -58,7 +58,7 @@ rand_core = "0.6.3"
 sdio-host = "0.5.0"
 embedded-sdmmc = { git = "https://github.com/embassy-rs/embedded-sdmmc-rs", rev = "a4f293d3a6f72158385f79c98634cb8a14d0d2fc", optional = true }
 critical-section = "1.1"
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-fbb8f77326dd066aa6c0d66b3b46e76a569dda8b" }
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-7117ad49c06fa00c388130a34977e029910083bd" }
 vcell = "0.1.3"
 bxcan = "0.7.0"
 nb = "1.0.0"
@@ -76,7 +76,7 @@ critical-section = { version = "1.1", features = ["std"] }
 [build-dependencies]
 proc-macro2 = "1.0.36"
 quote = "1.0.15"
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-fbb8f77326dd066aa6c0d66b3b46e76a569dda8b", default-features = false, features = ["metadata"]}
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-7117ad49c06fa00c388130a34977e029910083bd", default-features = false, features = ["metadata"]}
 
 
 [features]

embassy-stm32/build.rs

@@ -61,10 +61,10 @@ fn main() {
     let mut singletons: Vec<String> = Vec::new();
     for p in METADATA.peripherals {
         if let Some(r) = &p.registers {
+            println!("cargo:rustc-cfg=peri_{}", p.name.to_ascii_lowercase());
             match r.kind {
                 // Generate singletons per pin, not per port
                 "gpio" => {
-                    println!("{}", p.name);
                     let port_letter = p.name.strip_prefix("GPIO").unwrap();
                     for pin_num in 0..16 {
                         singletons.push(format!("P{}{}", port_letter, pin_num));
@@ -996,8 +996,8 @@ fn main() {
         // SDMMCv1 uses the same channel for both directions, so just implement for RX
         (("sdmmc", "RX"), quote!(crate::sdmmc::SdmmcDma)),
         (("quadspi", "QUADSPI"), quote!(crate::qspi::QuadDma)),
-        (("dac", "CH1"), quote!(crate::dac::DmaCh1)),
-        (("dac", "CH2"), quote!(crate::dac::DmaCh2)),
+        (("dac", "CH1"), quote!(crate::dac::DacDma1)),
+        (("dac", "CH2"), quote!(crate::dac::DacDma2)),
     ]
     .into();
 
@@ -1137,6 +1137,23 @@ fn main() {
         }
     }
 
+    // ========
+    // Write peripheral_interrupts module.
+    let mut mt = TokenStream::new();
+    for p in METADATA.peripherals {
+        let mut pt = TokenStream::new();
+
+        for irq in p.interrupts {
+            let iname = format_ident!("{}", irq.interrupt);
+            let sname = format_ident!("{}", irq.signal);
+            pt.extend(quote!(pub type #sname = crate::interrupt::typelevel::#iname;));
+        }
+
+        let pname = format_ident!("{}", p.name);
+        mt.extend(quote!(pub mod #pname { #pt }));
+    }
+    g.extend(quote!(#[allow(non_camel_case_types)] pub mod peripheral_interrupts { #mt }));
+
     // ========
     // Write foreach_foo! macrotables
 
@@ -1295,6 +1312,9 @@ fn main() {
 
     let mut m = String::new();
 
+    // DO NOT ADD more macros like these.
+    // These turned to be a bad idea!
+    // Instead, make build.rs generate the final code.
     make_table(&mut m, "foreach_flash_region", &flash_regions_table);
     make_table(&mut m, "foreach_interrupt", &interrupts_table);
     make_table(&mut m, "foreach_peripheral", &peripherals_table);
@@ -1331,15 +1351,6 @@ fn main() {
 
     if let Some(core) = core_name {
         println!("cargo:rustc-cfg={}_{}", &chip_name[..chip_name.len() - 2], core);
-    } else {
-        println!("cargo:rustc-cfg={}", &chip_name[..chip_name.len() - 2]);
-    }
-
-    // ========
-    // stm32f3 wildcard features used in RCC
-
-    if chip_name.starts_with("stm32f3") {
-        println!("cargo:rustc-cfg={}x{}", &chip_name[..9], &chip_name[10..11]);
     }
 
     // =======
@@ -1354,16 +1365,25 @@ fn main() {
     if &chip_name[..8] == "stm32wba" {
         println!("cargo:rustc-cfg={}", &chip_name[..8]); // stm32wba
         println!("cargo:rustc-cfg={}", &chip_name[..10]); // stm32wba52
+        println!("cargo:rustc-cfg=package_{}", &chip_name[10..11]);
+        println!("cargo:rustc-cfg=flashsize_{}", &chip_name[11..12]);
     } else {
         println!("cargo:rustc-cfg={}", &chip_name[..7]); // stm32f4
         println!("cargo:rustc-cfg={}", &chip_name[..9]); // stm32f429
         println!("cargo:rustc-cfg={}x", &chip_name[..8]); // stm32f42x
         println!("cargo:rustc-cfg={}x{}", &chip_name[..7], &chip_name[8..9]); // stm32f4x9
+        println!("cargo:rustc-cfg=package_{}", &chip_name[9..10]);
+        println!("cargo:rustc-cfg=flashsize_{}", &chip_name[10..11]);
     }
 
-    // Handle time-driver-XXXX features.
-    if env::var("CARGO_FEATURE_TIME_DRIVER_ANY").is_ok() {}
-    println!("cargo:rustc-cfg={}", &chip_name[..chip_name.len() - 2]);
+    // Mark the L4+ chips as they have many differences to regular L4.
+    if &chip_name[..7] == "stm32l4" {
+        if "pqrs".contains(&chip_name[7..8]) {
+            println!("cargo:rustc-cfg=stm32l4_plus");
+        } else {
+            println!("cargo:rustc-cfg=stm32l4_nonplus");
+        }
+    }
 
     println!("cargo:rerun-if-changed=build.rs");
 }

embassy-stm32/src/can/bxcan.rs

@@ -1,4 +1,3 @@
-use core::cell::{RefCell, RefMut};
 use core::future::poll_fn;
 use core::marker::PhantomData;
 use core::ops::{Deref, DerefMut};
@@ -84,7 +83,7 @@ impl<T: Instance> interrupt::typelevel::Handler<T::SCEInterrupt> for SceInterrup
 }
 
 pub struct Can<'d, T: Instance> {
-    pub can: RefCell<bxcan::Can<BxcanInstance<'d, T>>>,
+    pub can: bxcan::Can<BxcanInstance<'d, T>>,
 }
 
 #[derive(Debug)]
@@ -175,17 +174,12 @@ impl<'d, T: Instance> Can<'d, T> {
         tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
 
         let can = bxcan::Can::builder(BxcanInstance(peri)).leave_disabled();
-        let can_ref_cell = RefCell::new(can);
-        Self { can: can_ref_cell }
+        Self { can }
     }
 
     pub fn set_bitrate(&mut self, bitrate: u32) {
         let bit_timing = Self::calc_bxcan_timings(T::frequency(), bitrate).unwrap();
-        self.can
-            .borrow_mut()
-            .modify_config()
-            .set_bit_timing(bit_timing)
-            .leave_disabled();
+        self.can.modify_config().set_bit_timing(bit_timing).leave_disabled();
     }
 
     /// Enables the peripheral and synchronizes with the bus.
@@ -193,7 +187,7 @@ impl<'d, T: Instance> Can<'d, T> {
     /// This will wait for 11 consecutive recessive bits (bus idle state).
     /// Contrary to enable method from bxcan library, this will not freeze the executor while waiting.
     pub async fn enable(&mut self) {
-        while self.borrow_mut().enable_non_blocking().is_err() {
+        while self.enable_non_blocking().is_err() {
             // SCE interrupt is only generated for entering sleep mode, but not leaving.
             // Yield to allow other tasks to execute while can bus is initializing.
             embassy_futures::yield_now().await;
@@ -202,46 +196,46 @@ impl<'d, T: Instance> Can<'d, T> {
 
     /// Queues the message to be sent but exerts backpressure
     pub async fn write(&mut self, frame: &Frame) -> bxcan::TransmitStatus {
-        CanTx { can: &self.can }.write(frame).await
+        self.split().0.write(frame).await
     }
 
     /// Attempts to transmit a frame without blocking.
     ///
     /// Returns [Err(TryWriteError::Full)] if all transmit mailboxes are full.
     pub fn try_write(&mut self, frame: &Frame) -> Result<bxcan::TransmitStatus, TryWriteError> {
-        CanTx { can: &self.can }.try_write(frame)
+        self.split().0.try_write(frame)
     }
 
     /// Waits for a specific transmit mailbox to become empty
     pub async fn flush(&self, mb: bxcan::Mailbox) {
-        CanTx { can: &self.can }.flush(mb).await
+        CanTx::<T>::flush_inner(mb).await
     }
 
     /// Waits until any of the transmit mailboxes become empty
     pub async fn flush_any(&self) {
-        CanTx { can: &self.can }.flush_any().await
+        CanTx::<T>::flush_any_inner().await
     }
 
     /// Waits until all of the transmit mailboxes become empty
     pub async fn flush_all(&self) {
-        CanTx { can: &self.can }.flush_all().await
+        CanTx::<T>::flush_all_inner().await
     }
 
     /// Returns a tuple of the time the message was received and the message frame
     pub async fn read(&mut self) -> Result<Envelope, BusError> {
-        CanRx { can: &self.can }.read().await
+        self.split().1.read().await
     }
 
     /// Attempts to read a can frame without blocking.
     ///
     /// Returns [Err(TryReadError::Empty)] if there are no frames in the rx queue.
     pub fn try_read(&mut self) -> Result<Envelope, TryReadError> {
-        CanRx { can: &self.can }.try_read()
+        self.split().1.try_read()
     }
 
     /// Waits while receive queue is empty.
     pub async fn wait_not_empty(&mut self) {
-        CanRx { can: &self.can }.wait_not_empty().await
+        self.split().1.wait_not_empty().await
     }
 
     unsafe fn receive_fifo(fifo: RxFifo) {
@@ -385,24 +379,25 @@ impl<'d, T: Instance> Can<'d, T> {
         Some((sjw - 1) << 24 | (bs1 as u32 - 1) << 16 | (bs2 as u32 - 1) << 20 | (prescaler - 1))
     }
 
-    pub fn split<'c>(&'c self) -> (CanTx<'c, 'd, T>, CanRx<'c, 'd, T>) {
-        (CanTx { can: &self.can }, CanRx { can: &self.can })
+    pub fn split<'c>(&'c mut self) -> (CanTx<'c, 'd, T>, CanRx<'c, 'd, T>) {
+        let (tx, rx0, rx1) = self.can.split_by_ref();
+        (CanTx { tx }, CanRx { rx0, rx1 })
     }
 
-    pub fn as_mut(&self) -> RefMut<'_, bxcan::Can<BxcanInstance<'d, T>>> {
-        self.can.borrow_mut()
+    pub fn as_mut(&mut self) -> &mut bxcan::Can<BxcanInstance<'d, T>> {
+        &mut self.can
     }
 }
 
 pub struct CanTx<'c, 'd, T: Instance> {
-    can: &'c RefCell<bxcan::Can<BxcanInstance<'d, T>>>,
+    tx: &'c mut bxcan::Tx<BxcanInstance<'d, T>>,
 }
 
 impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
     pub async fn write(&mut self, frame: &Frame) -> bxcan::TransmitStatus {
         poll_fn(|cx| {
             T::state().tx_waker.register(cx.waker());
-            if let Ok(status) = self.can.borrow_mut().transmit(frame) {
+            if let Ok(status) = self.tx.transmit(frame) {
                 return Poll::Ready(status);
             }
 
@@ -415,11 +410,10 @@ impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
     ///
     /// Returns [Err(TryWriteError::Full)] if all transmit mailboxes are full.
     pub fn try_write(&mut self, frame: &Frame) -> Result<bxcan::TransmitStatus, TryWriteError> {
-        self.can.borrow_mut().transmit(frame).map_err(|_| TryWriteError::Full)
+        self.tx.transmit(frame).map_err(|_| TryWriteError::Full)
     }
 
-    /// Waits for a specific transmit mailbox to become empty
-    pub async fn flush(&self, mb: bxcan::Mailbox) {
+    async fn flush_inner(mb: bxcan::Mailbox) {
         poll_fn(|cx| {
             T::state().tx_waker.register(cx.waker());
             if T::regs().tsr().read().tme(mb.index()) {
@@ -431,8 +425,12 @@ impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
         .await;
     }
 
-    /// Waits until any of the transmit mailboxes become empty
-    pub async fn flush_any(&self) {
+    /// Waits for a specific transmit mailbox to become empty
+    pub async fn flush(&self, mb: bxcan::Mailbox) {
+        Self::flush_inner(mb).await
+    }
+
+    async fn flush_any_inner() {
         poll_fn(|cx| {
             T::state().tx_waker.register(cx.waker());
 
@@ -449,8 +447,12 @@ impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
         .await;
     }
 
-    /// Waits until all of the transmit mailboxes become empty
-    pub async fn flush_all(&self) {
+    /// Waits until any of the transmit mailboxes become empty
+    pub async fn flush_any(&self) {
+        Self::flush_any_inner().await
+    }
+
+    async fn flush_all_inner() {
         poll_fn(|cx| {
             T::state().tx_waker.register(cx.waker());
 
@@ -466,11 +468,17 @@ impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
         })
         .await;
     }
+
+    /// Waits until all of the transmit mailboxes become empty
+    pub async fn flush_all(&self) {
+        Self::flush_all_inner().await
+    }
 }
 
 #[allow(dead_code)]
 pub struct CanRx<'c, 'd, T: Instance> {
-    can: &'c RefCell<bxcan::Can<BxcanInstance<'d, T>>>,
+    rx0: &'c mut bxcan::Rx0<BxcanInstance<'d, T>>,
+    rx1: &'c mut bxcan::Rx1<BxcanInstance<'d, T>>,
 }
 
 impl<'c, 'd, T: Instance> CanRx<'c, 'd, T> {
@@ -538,7 +546,7 @@ impl<'d, T: Instance> Drop for Can<'d, T> {
 }
 
 impl<'d, T: Instance> Deref for Can<'d, T> {
-    type Target = RefCell<bxcan::Can<BxcanInstance<'d, T>>>;
+    type Target = bxcan::Can<BxcanInstance<'d, T>>;
 
     fn deref(&self) -> &Self::Target {
         &self.can

embassy-stm32/src/dac/mod.rs

@@ -1,136 +1,66 @@
+//! Provide access to the STM32 digital-to-analog converter (DAC).
 #![macro_use]
 
-//! Provide access to the STM32 digital-to-analog converter (DAC).
 use core::marker::PhantomData;
 
 use embassy_hal_internal::{into_ref, PeripheralRef};
 
+use crate::dma::NoDma;
+#[cfg(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7))]
 use crate::pac::dac;
 use crate::rcc::RccPeripheral;
 use crate::{peripherals, Peripheral};
 
+mod tsel;
+pub use tsel::TriggerSel;
+
+/// Operating mode for DAC channel
+#[cfg(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7))]
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// Custom Errors
-pub enum Error {
-    UnconfiguredChannel,
-    InvalidValue,
+pub enum Mode {
+    /// Normal mode, channel is connected to external pin with buffer enabled.
+    NormalExternalBuffered,
+    /// Normal mode, channel is connected to external pin and internal peripherals
+    /// with buffer enabled.
+    NormalBothBuffered,
+    /// Normal mode, channel is connected to external pin with buffer disabled.
+    NormalExternalUnbuffered,
+    /// Normal mode, channel is connected to internal peripherals with buffer disabled.
+    NormalInternalUnbuffered,
+    /// Sample-and-hold mode, channel is connected to external pin with buffer enabled.
+    SampleHoldExternalBuffered,
+    /// Sample-and-hold mode, channel is connected to external pin and internal peripherals
+    /// with buffer enabled.
+    SampleHoldBothBuffered,
+    /// Sample-and-hold mode, channel is connected to external pin and internal peripherals
+    /// with buffer disabled.
+    SampleHoldBothUnbuffered,
+    /// Sample-and-hold mode, channel is connected to internal peripherals with buffer disabled.
+    SampleHoldInternalUnbuffered,
 }
 
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// DAC Channels
-pub enum Channel {
-    Ch1,
-    Ch2,
-}
-
-impl Channel {
-    const fn index(&self) -> usize {
+#[cfg(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7))]
+impl Mode {
+    fn mode(&self) -> dac::vals::Mode {
         match self {
-            Channel::Ch1 => 0,
-            Channel::Ch2 => 1,
+            Mode::NormalExternalBuffered => dac::vals::Mode::NORMAL_EXT_BUFEN,
+            Mode::NormalBothBuffered => dac::vals::Mode::NORMAL_EXT_INT_BUFEN,
+            Mode::NormalExternalUnbuffered => dac::vals::Mode::NORMAL_EXT_BUFDIS,
+            Mode::NormalInternalUnbuffered => dac::vals::Mode::NORMAL_INT_BUFDIS,
+            Mode::SampleHoldExternalBuffered => dac::vals::Mode::SAMPHOLD_EXT_BUFEN,
+            Mode::SampleHoldBothBuffered => dac::vals::Mode::SAMPHOLD_EXT_INT_BUFEN,
+            Mode::SampleHoldBothUnbuffered => dac::vals::Mode::SAMPHOLD_EXT_INT_BUFDIS,
+            Mode::SampleHoldInternalUnbuffered => dac::vals::Mode::SAMPHOLD_INT_BUFDIS,
         }
     }
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// Trigger sources for CH1
-pub enum Ch1Trigger {
-    #[cfg(dac_v3)]
-    Tim1,
-    Tim2,
-    #[cfg(not(dac_v3))]
-    Tim3,
-    #[cfg(dac_v3)]
-    Tim4,
-    #[cfg(dac_v3)]
-    Tim5,
-    Tim6,
-    Tim7,
-    #[cfg(dac_v3)]
-    Tim8,
-    Tim15,
-    #[cfg(dac_v3)]
-    Hrtim1Dactrg1,
-    #[cfg(dac_v3)]
-    Hrtim1Dactrg2,
-    #[cfg(dac_v3)]
-    Lptim1,
-    #[cfg(dac_v3)]
-    Lptim2,
-    #[cfg(dac_v3)]
-    Lptim3,
-    Exti9,
-    Software,
-}
-
-impl Ch1Trigger {
-    fn tsel(&self) -> dac::vals::Tsel1 {
-        match self {
-            #[cfg(dac_v3)]
-            Ch1Trigger::Tim1 => dac::vals::Tsel1::TIM1_TRGO,
-            Ch1Trigger::Tim2 => dac::vals::Tsel1::TIM2_TRGO,
-            #[cfg(not(dac_v3))]
-            Ch1Trigger::Tim3 => dac::vals::Tsel1::TIM3_TRGO,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Tim4 => dac::vals::Tsel1::TIM4_TRGO,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Tim5 => dac::vals::Tsel1::TIM5_TRGO,
-            Ch1Trigger::Tim6 => dac::vals::Tsel1::TIM6_TRGO,
-            Ch1Trigger::Tim7 => dac::vals::Tsel1::TIM7_TRGO,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Tim8 => dac::vals::Tsel1::TIM8_TRGO,
-            Ch1Trigger::Tim15 => dac::vals::Tsel1::TIM15_TRGO,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Hrtim1Dactrg1 => dac::vals::Tsel1::HRTIM1_DACTRG1,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Hrtim1Dactrg2 => dac::vals::Tsel1::HRTIM1_DACTRG2,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Lptim1 => dac::vals::Tsel1::LPTIM1_OUT,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Lptim2 => dac::vals::Tsel1::LPTIM2_OUT,
-            #[cfg(dac_v3)]
-            Ch1Trigger::Lptim3 => dac::vals::Tsel1::LPTIM3_OUT,
-            Ch1Trigger::Exti9 => dac::vals::Tsel1::EXTI9,
-            Ch1Trigger::Software => dac::vals::Tsel1::SOFTWARE,
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// Trigger sources for CH2
-pub enum Ch2Trigger {
-    Tim6,
-    Tim8,
-    Tim7,
-    Tim5,
-    Tim2,
-    Tim4,
-    Exti9,
-    Software,
-}
-
-impl Ch2Trigger {
-    fn tsel(&self) -> dac::vals::Tsel2 {
-        match self {
-            Ch2Trigger::Tim6 => dac::vals::Tsel2::TIM6_TRGO,
-            Ch2Trigger::Tim8 => dac::vals::Tsel2::TIM8_TRGO,
-            Ch2Trigger::Tim7 => dac::vals::Tsel2::TIM7_TRGO,
-            Ch2Trigger::Tim5 => dac::vals::Tsel2::TIM5_TRGO,
-            Ch2Trigger::Tim2 => dac::vals::Tsel2::TIM2_TRGO,
-            Ch2Trigger::Tim4 => dac::vals::Tsel2::TIM4_TRGO,
-            Ch2Trigger::Exti9 => dac::vals::Tsel2::EXTI9,
-            Ch2Trigger::Software => dac::vals::Tsel2::SOFTWARE,
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// Single 8 or 12 bit value that can be output by the DAC
+/// Single 8 or 12 bit value that can be output by the DAC.
+///
+/// 12-bit values outside the permitted range are silently truncated.
 pub enum Value {
     // 8 bit value
     Bit8(u8),
@@ -142,7 +72,21 @@ pub enum Value {
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-/// Array variant of [`Value`]
+/// Dual 8 or 12 bit values that can be output by the DAC channels 1 and 2 simultaneously.
+///
+/// 12-bit values outside the permitted range are silently truncated.
+pub enum DualValue {
+    // 8 bit value
+    Bit8(u8, u8),
+    // 12 bit value stored in a u16, left-aligned
+    Bit12Left(u16, u16),
+    // 12 bit value stored in a u16, right-aligned
+    Bit12Right(u16, u16),
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Array variant of [`Value`].
 pub enum ValueArray<'a> {
     // 8 bit values
     Bit8(&'a [u8]),
@@ -151,398 +95,395 @@ pub enum ValueArray<'a> {
     // 12 bit values stored in a u16, right-aligned
     Bit12Right(&'a [u16]),
 }
-/// Provide common functions for DAC channels
-pub trait DacChannel<T: Instance, Tx> {
-    const CHANNEL: Channel;
 
-    /// Enable trigger of the given channel
-    fn set_trigger_enable(&mut self, on: bool) -> Result<(), Error> {
-        T::regs().cr().modify(|reg| {
-            reg.set_ten(Self::CHANNEL.index(), on);
-        });
-        Ok(())
-    }
-
-    /// Set mode register of the given channel
-    #[cfg(any(dac_v2, dac_v3))]
-    fn set_channel_mode(&mut self, val: u8) -> Result<(), Error> {
-        T::regs().mcr().modify(|reg| {
-            reg.set_mode(Self::CHANNEL.index(), val);
-        });
-        Ok(())
-    }
-
-    /// Set enable register of the given channel
-    fn set_channel_enable(&mut self, on: bool) -> Result<(), Error> {
-        T::regs().cr().modify(|reg| {
-            reg.set_en(Self::CHANNEL.index(), on);
-        });
-        Ok(())
-    }
-
-    /// Enable the DAC channel `ch`
-    fn enable_channel(&mut self) -> Result<(), Error> {
-        self.set_channel_enable(true)
-    }
-
-    /// Disable the DAC channel `ch`
-    fn disable_channel(&mut self) -> Result<(), Error> {
-        self.set_channel_enable(false)
-    }
-
-    /// Perform a software trigger on `ch`
-    fn trigger(&mut self) {
-        T::regs().swtrigr().write(|reg| {
-            reg.set_swtrig(Self::CHANNEL.index(), true);
-        });
-    }
-
-    /// Set a value to be output by the DAC on trigger.
-    ///
-    /// The `value` is written to the corresponding "data holding register".
-    fn set(&mut self, value: Value) -> Result<(), Error> {
-        match value {
-            Value::Bit8(v) => T::regs().dhr8r(Self::CHANNEL.index()).write(|reg| reg.set_dhr(v)),
-            Value::Bit12Left(v) => T::regs().dhr12l(Self::CHANNEL.index()).write(|reg| reg.set_dhr(v)),
-            Value::Bit12Right(v) => T::regs().dhr12r(Self::CHANNEL.index()).write(|reg| reg.set_dhr(v)),
-        }
-        Ok(())
-    }
-}
-
-/// Hold two DAC channels
+/// Driver for a single DAC channel.
 ///
-/// Note: This consumes the DAC `Instance` only once, allowing to get both channels simultaneously.
-///
-/// # Example for obtaining both DAC channels
-///
-/// ```ignore
-/// // DMA channels and pins may need to be changed for your controller
-/// let (dac_ch1, dac_ch2) =
-///     embassy_stm32::dac::Dac::new(p.DAC1, p.DMA1_CH3, p.DMA1_CH4, p.PA4, p.PA5).split();
-/// ```
-pub struct Dac<'d, T: Instance, TxCh1, TxCh2> {
-    ch1: DacCh1<'d, T, TxCh1>,
-    ch2: DacCh2<'d, T, TxCh2>,
-}
-
-/// DAC CH1
-///
-/// Note: This consumes the DAC `Instance`. Use [`Dac::new`] to get both channels simultaneously.
-pub struct DacCh1<'d, T: Instance, Tx> {
-    /// To consume T
-    _peri: PeripheralRef<'d, T>,
-    #[allow(unused)] // For chips whose DMA is not (yet) supported
-    dma: PeripheralRef<'d, Tx>,
-}
-
-/// DAC CH2
-///
-/// Note: This consumes the DAC `Instance`. Use [`Dac::new`] to get both channels simultaneously.
-pub struct DacCh2<'d, T: Instance, Tx> {
-    /// Instead of PeripheralRef to consume T
+/// If you want to use both channels, either together or independently,
+/// create a [`Dac`] first and use it to access each channel.
+pub struct DacChannel<'d, T: Instance, const N: u8, DMA = NoDma> {
     phantom: PhantomData<&'d mut T>,
-    #[allow(unused)] // For chips whose DMA is not (yet) supported
-    dma: PeripheralRef<'d, Tx>,
+    #[allow(unused)]
+    dma: PeripheralRef<'d, DMA>,
 }
 
-impl<'d, T: Instance, Tx> DacCh1<'d, T, Tx> {
-    /// Obtain DAC CH1
-    pub fn new(
-        peri: impl Peripheral<P = T> + 'd,
-        dma: impl Peripheral<P = Tx> + 'd,
-        pin: impl Peripheral<P = impl DacPin<T, 1>> + crate::gpio::sealed::Pin + 'd,
-    ) -> Self {
-        pin.set_as_analog();
-        into_ref!(peri, dma);
-        T::enable_and_reset();
+pub type DacCh1<'d, T, DMA = NoDma> = DacChannel<'d, T, 1, DMA>;
+pub type DacCh2<'d, T, DMA = NoDma> = DacChannel<'d, T, 2, DMA>;
 
-        let mut dac = Self { _peri: peri, dma };
+impl<'d, T: Instance, const N: u8, DMA> DacChannel<'d, T, N, DMA> {
+    const IDX: usize = (N - 1) as usize;
 
-        // Configure each activated channel. All results can be `unwrap`ed since they
-        // will only error if the channel is not configured (i.e. ch1, ch2 are false)
-        #[cfg(any(dac_v2, dac_v3))]
-        dac.set_channel_mode(0).unwrap();
-        dac.enable_channel().unwrap();
-        dac.set_trigger_enable(true).unwrap();
-
-        dac
-    }
-
-    /// Select a new trigger for this channel
+    /// Create a new `DacChannel` instance, consuming the underlying DAC peripheral.
     ///
-    /// **Important**: This disables the channel!
-    pub fn select_trigger(&mut self, trigger: Ch1Trigger) -> Result<(), Error> {
-        unwrap!(self.disable_channel());
-        T::regs().cr().modify(|reg| {
-            reg.set_tsel1(trigger.tsel());
-        });
-        Ok(())
-    }
-
-    /// Write `data` to the DAC CH1 via DMA.
+    /// If you're not using DMA, pass [`dma::NoDma`] for the `dma` argument.
     ///
-    /// To prevent delays/glitches when outputting a periodic waveform, the `circular` flag can be set.
-    /// This will configure a circular DMA transfer that periodically outputs the `data`.
-    /// Note that for performance reasons in circular mode the transfer complete interrupt is disabled.
+    /// The channel is enabled on creation and begins to drive the output pin.
+    /// Note that some methods, such as `set_trigger()` and `set_mode()`, will
+    /// disable the channel; you must re-enable it with `enable()`.
     ///
-    /// **Important:** Channel 1 has to be configured for the DAC instance!
-    pub async fn write(&mut self, data: ValueArray<'_>, circular: bool) -> Result<(), Error>
-    where
-        Tx: DmaCh1<T>,
-    {
-        let channel = Channel::Ch1.index();
-        debug!("Writing to channel {}", channel);
-
-        // Enable DAC and DMA
-        T::regs().cr().modify(|w| {
-            w.set_en(channel, true);
-            w.set_dmaen(channel, true);
-        });
-
-        let tx_request = self.dma.request();
-        let dma_channel = &mut self.dma;
-
-        let tx_options = crate::dma::TransferOptions {
-            circular,
-            half_transfer_ir: false,
-            complete_transfer_ir: !circular,
-            ..Default::default()
-        };
-
-        // Initiate the correct type of DMA transfer depending on what data is passed
-        let tx_f = match data {
-            ValueArray::Bit8(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr8r(channel).as_ptr() as *mut u8,
-                    tx_options,
-                )
-            },
-            ValueArray::Bit12Left(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr12l(channel).as_ptr() as *mut u16,
-                    tx_options,
-                )
-            },
-            ValueArray::Bit12Right(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr12r(channel).as_ptr() as *mut u16,
-                    tx_options,
-                )
-            },
-        };
-
-        tx_f.await;
-
-        // finish dma
-        // TODO: Do we need to check any status registers here?
-        T::regs().cr().modify(|w| {
-            // Disable the DAC peripheral
-            w.set_en(channel, false);
-            // Disable the DMA. TODO: Is this necessary?
-            w.set_dmaen(channel, false);
-        });
-
-        Ok(())
-    }
-}
-
-impl<'d, T: Instance, Tx> DacCh2<'d, T, Tx> {
-    /// Obtain DAC CH2
+    /// By default, triggering is disabled, but it can be enabled using
+    /// [`DacChannel::set_trigger()`].
     pub fn new(
         _peri: impl Peripheral<P = T> + 'd,
-        dma: impl Peripheral<P = Tx> + 'd,
-        pin: impl Peripheral<P = impl DacPin<T, 2>> + crate::gpio::sealed::Pin + 'd,
+        dma: impl Peripheral<P = DMA> + 'd,
+        pin: impl Peripheral<P = impl DacPin<T, N> + crate::gpio::sealed::Pin> + 'd,
     ) -> Self {
+        into_ref!(dma, pin);
         pin.set_as_analog();
-        into_ref!(_peri, dma);
         T::enable_and_reset();
-
         let mut dac = Self {
             phantom: PhantomData,
             dma,
         };
-
-        // Configure each activated channel. All results can be `unwrap`ed since they
-        // will only error if the channel is not configured (i.e. ch1, ch2 are false)
-        #[cfg(any(dac_v2, dac_v3))]
-        dac.set_channel_mode(0).unwrap();
-        dac.enable_channel().unwrap();
-        dac.set_trigger_enable(true).unwrap();
-
+        #[cfg(any(dac_v5, dac_v6, dac_v7))]
+        dac.set_hfsel();
+        dac.enable();
         dac
     }
 
-    /// Select a new trigger for this channel
-    pub fn select_trigger(&mut self, trigger: Ch2Trigger) -> Result<(), Error> {
-        unwrap!(self.disable_channel());
-        T::regs().cr().modify(|reg| {
-            reg.set_tsel2(trigger.tsel());
-        });
-        Ok(())
-    }
-
-    /// Write `data` to the DAC CH2 via DMA.
+    /// Create a new `DacChannel` instance where the external output pin is not used,
+    /// so the DAC can only be used to generate internal signals.
+    /// The GPIO pin is therefore available to be used for other functions.
     ///
-    /// To prevent delays/glitches when outputting a periodic waveform, the `circular` flag can be set.
-    /// This will configure a circular DMA transfer that periodically outputs the `data`.
-    /// Note that for performance reasons in circular mode the transfer complete interrupt is disabled.
+    /// The channel is set to [`Mode::NormalInternalUnbuffered`] and enabled on creation.
+    /// Note that some methods, such as `set_trigger()` and `set_mode()`, will disable the
+    /// channel; you must re-enable it with `enable()`.
     ///
-    /// **Important:** Channel 2 has to be configured for the DAC instance!
-    pub async fn write(&mut self, data: ValueArray<'_>, circular: bool) -> Result<(), Error>
-    where
-        Tx: DmaCh2<T>,
-    {
-        let channel = Channel::Ch2.index();
-        debug!("Writing to channel {}", channel);
-
-        // Enable DAC and DMA
-        T::regs().cr().modify(|w| {
-            w.set_en(channel, true);
-            w.set_dmaen(channel, true);
-        });
-
-        let tx_request = self.dma.request();
-        let dma_channel = &mut self.dma;
-
-        let tx_options = crate::dma::TransferOptions {
-            circular,
-            half_transfer_ir: false,
-            complete_transfer_ir: !circular,
-            ..Default::default()
-        };
-
-        // Initiate the correct type of DMA transfer depending on what data is passed
-        let tx_f = match data {
-            ValueArray::Bit8(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr8r(channel).as_ptr() as *mut u8,
-                    tx_options,
-                )
-            },
-            ValueArray::Bit12Left(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr12l(channel).as_ptr() as *mut u16,
-                    tx_options,
-                )
-            },
-            ValueArray::Bit12Right(buf) => unsafe {
-                crate::dma::Transfer::new_write(
-                    dma_channel,
-                    tx_request,
-                    buf,
-                    T::regs().dhr12r(channel).as_ptr() as *mut u16,
-                    tx_options,
-                )
-            },
-        };
-
-        tx_f.await;
-
-        // finish dma
-        // TODO: Do we need to check any status registers here?
-        T::regs().cr().modify(|w| {
-            // Disable the DAC peripheral
-            w.set_en(channel, false);
-            // Disable the DMA. TODO: Is this necessary?
-            w.set_dmaen(channel, false);
-        });
-
-        Ok(())
-    }
-}
-
-impl<'d, T: Instance, TxCh1, TxCh2> Dac<'d, T, TxCh1, TxCh2> {
-    /// Create a new DAC instance with both channels.
+    /// If you're not using DMA, pass [`dma::NoDma`] for the `dma` argument.
     ///
-    /// This is used to obtain two independent channels via `split()` for use e.g. with DMA.
-    pub fn new(
-        peri: impl Peripheral<P = T> + 'd,
-        dma_ch1: impl Peripheral<P = TxCh1> + 'd,
-        dma_ch2: impl Peripheral<P = TxCh2> + 'd,
-        pin_ch1: impl Peripheral<P = impl DacPin<T, 1>> + crate::gpio::sealed::Pin + 'd,
-        pin_ch2: impl Peripheral<P = impl DacPin<T, 2>> + crate::gpio::sealed::Pin + 'd,
-    ) -> Self {
-        pin_ch1.set_as_analog();
-        pin_ch2.set_as_analog();
-        into_ref!(peri, dma_ch1, dma_ch2);
+    /// By default, triggering is disabled, but it can be enabled using
+    /// [`DacChannel::set_trigger()`].
+    #[cfg(all(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7), not(any(stm32h56x, stm32h57x))))]
+    pub fn new_internal(_peri: impl Peripheral<P = T> + 'd, dma: impl Peripheral<P = DMA> + 'd) -> Self {
+        into_ref!(dma);
         T::enable_and_reset();
-
-        let mut dac_ch1 = DacCh1 {
-            _peri: peri,
-            dma: dma_ch1,
-        };
-
-        let mut dac_ch2 = DacCh2 {
+        let mut dac = Self {
             phantom: PhantomData,
-            dma: dma_ch2,
+            dma,
         };
+        #[cfg(any(dac_v5, dac_v6, dac_v7))]
+        dac.set_hfsel();
+        dac.set_mode(Mode::NormalInternalUnbuffered);
+        dac.enable();
+        dac
+    }
 
-        // Configure each activated channel. All results can be `unwrap`ed since they
-        // will only error if the channel is not configured (i.e. ch1, ch2 are false)
-        #[cfg(any(dac_v2, dac_v3))]
-        dac_ch1.set_channel_mode(0).unwrap();
-        dac_ch1.enable_channel().unwrap();
-        dac_ch1.set_trigger_enable(true).unwrap();
+    /// Enable or disable this channel.
+    pub fn set_enable(&mut self, on: bool) {
+        critical_section::with(|_| {
+            T::regs().cr().modify(|reg| {
+                reg.set_en(Self::IDX, on);
+            });
+        });
+    }
 
-        #[cfg(any(dac_v2, dac_v3))]
-        dac_ch2.set_channel_mode(0).unwrap();
-        dac_ch2.enable_channel().unwrap();
-        dac_ch2.set_trigger_enable(true).unwrap();
+    /// Enable this channel.
+    pub fn enable(&mut self) {
+        self.set_enable(true)
+    }
 
-        Self {
-            ch1: dac_ch1,
-            ch2: dac_ch2,
+    /// Disable this channel.
+    pub fn disable(&mut self) {
+        self.set_enable(false)
+    }
+
+    /// Set the trigger source for this channel.
+    ///
+    /// This method disables the channel, so you may need to re-enable afterwards.
+    pub fn set_trigger(&mut self, source: TriggerSel) {
+        critical_section::with(|_| {
+            T::regs().cr().modify(|reg| {
+                reg.set_en(Self::IDX, false);
+                reg.set_tsel(Self::IDX, source as u8);
+            });
+        });
+    }
+
+    /// Enable or disable triggering for this channel.
+    pub fn set_triggering(&mut self, on: bool) {
+        critical_section::with(|_| {
+            T::regs().cr().modify(|reg| {
+                reg.set_ten(Self::IDX, on);
+            });
+        });
+    }
+
+    /// Software trigger this channel.
+    pub fn trigger(&mut self) {
+        T::regs().swtrigr().write(|reg| {
+            reg.set_swtrig(Self::IDX, true);
+        });
+    }
+
+    /// Set mode of this channel.
+    ///
+    /// This method disables the channel, so you may need to re-enable afterwards.
+    #[cfg(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7))]
+    pub fn set_mode(&mut self, mode: Mode) {
+        critical_section::with(|_| {
+            T::regs().cr().modify(|reg| {
+                reg.set_en(Self::IDX, false);
+            });
+            T::regs().mcr().modify(|reg| {
+                reg.set_mode(Self::IDX, mode.mode());
+            });
+        });
+    }
+
+    /// Write a new value to this channel.
+    ///
+    /// If triggering is not enabled, the new value is immediately output; otherwise,
+    /// it will be output after the next trigger.
+    pub fn set(&mut self, value: Value) {
+        match value {
+            Value::Bit8(v) => T::regs().dhr8r(Self::IDX).write(|reg| reg.set_dhr(v)),
+            Value::Bit12Left(v) => T::regs().dhr12l(Self::IDX).write(|reg| reg.set_dhr(v)),
+            Value::Bit12Right(v) => T::regs().dhr12r(Self::IDX).write(|reg| reg.set_dhr(v)),
         }
     }
 
-    /// Split the DAC into CH1 and CH2 for independent use.
-    pub fn split(self) -> (DacCh1<'d, T, TxCh1>, DacCh2<'d, T, TxCh2>) {
+    /// Read the current output value of the DAC.
+    pub fn read(&self) -> u16 {
+        T::regs().dor(Self::IDX).read().dor()
+    }
+
+    /// Set HFSEL as appropriate for the current peripheral clock frequency.
+    #[cfg(dac_v5)]
+    fn set_hfsel(&mut self) {
+        if T::frequency() >= crate::time::mhz(80) {
+            critical_section::with(|_| {
+                T::regs().cr().modify(|reg| {
+                    reg.set_hfsel(true);
+                });
+            });
+        }
+    }
+
+    /// Set HFSEL as appropriate for the current peripheral clock frequency.
+    #[cfg(any(dac_v6, dac_v7))]
+    fn set_hfsel(&mut self) {
+        if T::frequency() >= crate::time::mhz(160) {
+            critical_section::with(|_| {
+                T::regs().mcr().modify(|reg| {
+                    reg.set_hfsel(0b10);
+                });
+            });
+        } else if T::frequency() >= crate::time::mhz(80) {
+            critical_section::with(|_| {
+                T::regs().mcr().modify(|reg| {
+                    reg.set_hfsel(0b01);
+                });
+            });
+        }
+    }
+}
+
+macro_rules! impl_dma_methods {
+    ($n:literal, $trait:ident) => {
+        impl<'d, T: Instance, DMA> DacChannel<'d, T, $n, DMA>
+        where
+            DMA: $trait<T>,
+        {
+            /// Write `data` to this channel via DMA.
+            ///
+            /// To prevent delays or glitches when outputing a periodic waveform, the `circular`
+            /// flag can be set. This configures a circular DMA transfer that continually outputs
+            /// `data`. Note that for performance reasons in circular mode the transfer-complete
+            /// interrupt is disabled.
+            #[cfg(not(gpdma))]
+            pub async fn write(&mut self, data: ValueArray<'_>, circular: bool) {
+                // Enable DAC and DMA
+                T::regs().cr().modify(|w| {
+                    w.set_en(Self::IDX, true);
+                    w.set_dmaen(Self::IDX, true);
+                });
+
+                let tx_request = self.dma.request();
+                let dma_channel = &mut self.dma;
+
+                let tx_options = crate::dma::TransferOptions {
+                    circular,
+                    half_transfer_ir: false,
+                    complete_transfer_ir: !circular,
+                    ..Default::default()
+                };
+
+                // Initiate the correct type of DMA transfer depending on what data is passed
+                let tx_f = match data {
+                    ValueArray::Bit8(buf) => unsafe {
+                        crate::dma::Transfer::new_write(
+                            dma_channel,
+                            tx_request,
+                            buf,
+                            T::regs().dhr8r(Self::IDX).as_ptr() as *mut u8,
+                            tx_options,
+                        )
+                    },
+                    ValueArray::Bit12Left(buf) => unsafe {
+                        crate::dma::Transfer::new_write(
+                            dma_channel,
+                            tx_request,
+                            buf,
+                            T::regs().dhr12l(Self::IDX).as_ptr() as *mut u16,
+                            tx_options,
+                        )
+                    },
+                    ValueArray::Bit12Right(buf) => unsafe {
+                        crate::dma::Transfer::new_write(
+                            dma_channel,
+                            tx_request,
+                            buf,
+                            T::regs().dhr12r(Self::IDX).as_ptr() as *mut u16,
+                            tx_options,
+                        )
+                    },
+                };
+
+                tx_f.await;
+
+                T::regs().cr().modify(|w| {
+                    w.set_en(Self::IDX, false);
+                    w.set_dmaen(Self::IDX, false);
+                });
+            }
+        }
+    };
+}
+
+impl_dma_methods!(1, DacDma1);
+impl_dma_methods!(2, DacDma2);
+
+impl<'d, T: Instance, const N: u8, DMA> Drop for DacChannel<'d, T, N, DMA> {
+    fn drop(&mut self) {
+        T::disable();
+    }
+}
+
+/// DAC driver.
+///
+/// Use this struct when you want to use both channels, either together or independently.
+///
+/// # Example
+///
+/// ```ignore
+/// // Pins may need to be changed for your specific device.
+/// let (dac_ch1, dac_ch2) = embassy_stm32::dac::Dac::new(p.DAC, NoDma, NoDma, p.PA4, p.PA5).split();
+/// ```
+pub struct Dac<'d, T: Instance, DMACh1 = NoDma, DMACh2 = NoDma> {
+    ch1: DacChannel<'d, T, 1, DMACh1>,
+    ch2: DacChannel<'d, T, 2, DMACh2>,
+}
+
+impl<'d, T: Instance, DMACh1, DMACh2> Dac<'d, T, DMACh1, DMACh2> {
+    /// Create a new `Dac` instance, consuming the underlying DAC peripheral.
+    ///
+    /// This struct allows you to access both channels of the DAC, where available. You can either
+    /// call `split()` to obtain separate `DacChannel`s, or use methods on `Dac` to use
+    /// the two channels together.
+    ///
+    /// The channels are enabled on creation and begins to drive their output pins.
+    /// Note that some methods, such as `set_trigger()` and `set_mode()`, will
+    /// disable the channel; you must re-enable them with `enable()`.
+    ///
+    /// By default, triggering is disabled, but it can be enabled using the `set_trigger()`
+    /// method on the underlying channels.
+    pub fn new(
+        _peri: impl Peripheral<P = T> + 'd,
+        dma_ch1: impl Peripheral<P = DMACh1> + 'd,
+        dma_ch2: impl Peripheral<P = DMACh2> + 'd,
+        pin_ch1: impl Peripheral<P = impl DacPin<T, 1> + crate::gpio::sealed::Pin> + 'd,
+        pin_ch2: impl Peripheral<P = impl DacPin<T, 2> + crate::gpio::sealed::Pin> + 'd,
+    ) -> Self {
+        into_ref!(dma_ch1, dma_ch2, pin_ch1, pin_ch2);
+        pin_ch1.set_as_analog();
+        pin_ch2.set_as_analog();
+        // Enable twice to increment the DAC refcount for each channel.
+        T::enable_and_reset();
+        T::enable_and_reset();
+        Self {
+            ch1: DacCh1 {
+                phantom: PhantomData,
+                dma: dma_ch1,
+            },
+            ch2: DacCh2 {
+                phantom: PhantomData,
+                dma: dma_ch2,
+            },
+        }
+    }
+
+    /// Create a new `Dac` instance where the external output pins are not used,
+    /// so the DAC can only be used to generate internal signals but the GPIO
+    /// pins remain available for other functions.
+    ///
+    /// This struct allows you to access both channels of the DAC, where available. You can either
+    /// call `split()` to obtain separate `DacChannel`s, or use methods on `Dac` to use the two
+    /// channels together.
+    ///
+    /// The channels are set to [`Mode::NormalInternalUnbuffered`] and enabled on creation.
+    /// Note that some methods, such as `set_trigger()` and `set_mode()`, will disable the
+    /// channel; you must re-enable them with `enable()`.
+    ///
+    /// By default, triggering is disabled, but it can be enabled using the `set_trigger()`
+    /// method on the underlying channels.
+    #[cfg(all(any(dac_v3, dac_v4, dac_v5, dac_v6, dac_v7), not(any(stm32h56x, stm32h57x))))]
+    pub fn new_internal(
+        _peri: impl Peripheral<P = T> + 'd,
+        dma_ch1: impl Peripheral<P = DMACh1> + 'd,
+        dma_ch2: impl Peripheral<P = DMACh2> + 'd,
+    ) -> Self {
+        into_ref!(dma_ch1, dma_ch2);
+        // Enable twice to increment the DAC refcount for each channel.
+        T::enable_and_reset();
+        T::enable_and_reset();
+        Self {
+            ch1: DacCh1 {
+                phantom: PhantomData,
+                dma: dma_ch1,
+            },
+            ch2: DacCh2 {
+                phantom: PhantomData,
+                dma: dma_ch2,
+            },
+        }
+    }
+
+    /// Split this `Dac` into separate channels.
+    ///
+    /// You can access and move the channels around separately after splitting.
+    pub fn split(self) -> (DacCh1<'d, T, DMACh1>, DacCh2<'d, T, DMACh2>) {
         (self.ch1, self.ch2)
     }
 
-    /// Get mutable reference to CH1
-    pub fn ch1_mut(&mut self) -> &mut DacCh1<'d, T, TxCh1> {
+    /// Temporarily access channel 1.
+    pub fn ch1(&mut self) -> &mut DacCh1<'d, T, DMACh1> {
         &mut self.ch1
     }
 
-    /// Get mutable reference to CH2
-    pub fn ch2_mut(&mut self) -> &mut DacCh2<'d, T, TxCh2> {
+    /// Temporarily access channel 2.
+    pub fn ch2(&mut self) -> &mut DacCh2<'d, T, DMACh2> {
         &mut self.ch2
     }
 
-    /// Get reference to CH1
-    pub fn ch1(&mut self) -> &DacCh1<'d, T, TxCh1> {
-        &self.ch1
+    /// Simultaneously update channels 1 and 2 with a new value.
+    ///
+    /// If triggering is not enabled, the new values are immediately output;
+    /// otherwise, they will be output after the next trigger.
+    pub fn set(&mut self, values: DualValue) {
+        match values {
+            DualValue::Bit8(v1, v2) => T::regs().dhr8rd().write(|reg| {
+                reg.set_dhr(0, v1);
+                reg.set_dhr(1, v2);
+            }),
+            DualValue::Bit12Left(v1, v2) => T::regs().dhr12ld().write(|reg| {
+                reg.set_dhr(0, v1);
+                reg.set_dhr(1, v2);
+            }),
+            DualValue::Bit12Right(v1, v2) => T::regs().dhr12rd().write(|reg| {
+                reg.set_dhr(0, v1);
+                reg.set_dhr(1, v2);
+            }),
+        }
     }
-
-    /// Get reference to CH2
-    pub fn ch2(&mut self) -> &DacCh2<'d, T, TxCh2> {
-        &self.ch2
-    }
-}
-
-impl<'d, T: Instance, Tx> DacChannel<T, Tx> for DacCh1<'d, T, Tx> {
-    const CHANNEL: Channel = Channel::Ch1;
-}
-
-impl<'d, T: Instance, Tx> DacChannel<T, Tx> for DacCh2<'d, T, Tx> {
-    const CHANNEL: Channel = Channel::Ch2;
 }
 
 pub(crate) mod sealed {
@@ -552,34 +493,36 @@ pub(crate) mod sealed {
 }
 
 pub trait Instance: sealed::Instance + RccPeripheral + 'static {}
-dma_trait!(DmaCh1, Instance);
-dma_trait!(DmaCh2, Instance);
+dma_trait!(DacDma1, Instance);
+dma_trait!(DacDma2, Instance);
 
 /// Marks a pin that can be used with the DAC
 pub trait DacPin<T: Instance, const C: u8>: crate::gpio::Pin + 'static {}
 
 foreach_peripheral!(
     (dac, $inst:ident) => {
-                // H7 uses single bit for both DAC1 and DAC2, this is a hack until a proper fix is implemented
-                #[cfg(any(rcc_h7, rcc_h7rm0433))]
-                impl crate::rcc::sealed::RccPeripheral for peripherals::$inst {
-                    fn frequency() -> crate::time::Hertz {
-                        critical_section::with(|_| unsafe { crate::rcc::get_freqs().pclk1 })
-                    }
+        // H7 uses single bit for both DAC1 and DAC2, this is a hack until a proper fix is implemented
+        #[cfg(any(rcc_h7, rcc_h7rm0433))]
+        impl crate::rcc::sealed::RccPeripheral for peripherals::$inst {
+            fn frequency() -> crate::time::Hertz {
+                critical_section::with(|_| unsafe { crate::rcc::get_freqs().pclk1 })
+            }
 
-                    fn enable_and_reset_with_cs(_cs: critical_section::CriticalSection) {
-                        crate::pac::RCC.apb1lrstr().modify(|w| w.set_dac12rst(true));
-                        crate::pac::RCC.apb1lrstr().modify(|w| w.set_dac12rst(false));
-                        crate::pac::RCC.apb1lenr().modify(|w| w.set_dac12en(true));
-                    }
+            fn enable_and_reset_with_cs(_cs: critical_section::CriticalSection) {
+                // TODO: Increment refcount?
+                crate::pac::RCC.apb1lrstr().modify(|w| w.set_dac12rst(true));
+                crate::pac::RCC.apb1lrstr().modify(|w| w.set_dac12rst(false));
+                crate::pac::RCC.apb1lenr().modify(|w| w.set_dac12en(true));
+            }
 
-                    fn disable_with_cs(_cs: critical_section::CriticalSection) {
-                        crate::pac::RCC.apb1lenr().modify(|w| w.set_dac12en(false))
-                    }
-                }
+            fn disable_with_cs(_cs: critical_section::CriticalSection) {
+                // TODO: Decrement refcount?
+                crate::pac::RCC.apb1lenr().modify(|w| w.set_dac12en(false))
+            }
+        }
 
-                #[cfg(any(rcc_h7, rcc_h7rm0433))]
-                impl crate::rcc::RccPeripheral for peripherals::$inst {}
+        #[cfg(any(rcc_h7, rcc_h7rm0433))]
+        impl crate::rcc::RccPeripheral for peripherals::$inst {}
 
         impl crate::dac::sealed::Instance for peripherals::$inst {
             fn regs() -> &'static crate::pac::dac::Dac {

embassy-stm32/src/dac/tsel.rs

@@ -0,0 +1,282 @@
+/// Trigger selection for STM32F0.
+#[cfg(stm32f0)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    Tim3 = 1,
+    Tim7 = 2,
+    Tim15 = 3,
+    Tim2 = 4,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F1.
+#[cfg(stm32f1)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    #[cfg(any(stm32f100, stm32f105, stm32f107))]
+    Tim3 = 1,
+    #[cfg(any(stm32f101, stm32f103))]
+    Tim8 = 1,
+    Tim7 = 2,
+    #[cfg(any(stm32f101, stm32f103, stm32f105, stm32f107))]
+    Tim5 = 3,
+    #[cfg(all(stm32f100, any(flashsize_4, flashsize_6, flashsize_8, flashsize_b)))]
+    Tim15 = 3,
+    #[cfg(all(stm32f100, any(flashsize_c, flashsize_d, flashsize_e)))]
+    /// Can be remapped to TIM15 with MISC_REMAP in AFIO_MAPR2.
+    Tim5Or15 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F2/F4/F7/L4, except F410 or L4+.
+#[cfg(all(any(stm32f2, stm32f4, stm32f7, stm32l4_nonplus), not(stm32f410)))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    Tim8 = 1,
+    #[cfg(not(any(stm32l45x, stm32l46x)))]
+    Tim7 = 2,
+    Tim5 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F410.
+#[cfg(stm32f410)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim5 = 3,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F301/2 and 318.
+#[cfg(any(stm32f301, stm32f302, stm32f318))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    #[cfg(stm32f302)]
+    /// Requires DAC_TRIG_RMP set in SYSCFG_CFGR1.
+    Tim3 = 1,
+    Tim15 = 3,
+    Tim2 = 4,
+    #[cfg(all(stm32f302, any(flashsize_6, flashsize_8)))]
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F303/3x8 (excluding 318 which is like 301, and 378 which is 37x).
+#[cfg(any(stm32f303, stm32f328, stm32f358, stm32f398))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    /// * DAC1: defaults to TIM8 but can be remapped to TIM3 with DAC_TRIG_RMP in SYSCFG_CFGR1
+    /// * DAC2: always TIM3
+    Tim8Or3 = 1,
+    Tim7 = 2,
+    Tim15 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F37x.
+#[cfg(any(stm32f373, stm32f378))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    Tim3 = 1,
+    Tim7 = 2,
+    /// TIM5 on DAC1, TIM18 on DAC2
+    Dac1Tim5Dac2Tim18 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32F334.
+#[cfg(stm32f334)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    /// Requires DAC_TRIG_RMP set in SYSCFG_CFGR1.
+    Tim3 = 1,
+    Tim7 = 2,
+    /// Can be remapped to HRTIM_DACTRG1 using DAC1_TRIG3_RMP in SYSCFG_CFGR3.
+    Tim15OrHrtimDacTrg1 = 3,
+    Tim2 = 4,
+    /// Requires DAC_TRIG5_RMP set in SYSCFG_CFGR3.
+    HrtimDacTrg2 = 5,
+}
+
+/// Trigger selection for STM32L0.
+#[cfg(stm32l0)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    Tim3 = 1,
+    Tim3Ch3 = 2,
+    Tim21 = 3,
+    Tim2 = 4,
+    Tim7 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for STM32L1.
+#[cfg(stm32l1)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Tim6 = 0,
+    Tim7 = 2,
+    Tim9 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Software = 7,
+}
+
+/// Trigger selection for L4+, L5, U5, H7.
+#[cfg(any(stm32l4_plus, stm32l5, stm32u5, stm32h7))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Software = 0,
+    Tim1 = 1,
+    Tim2 = 2,
+    Tim4 = 3,
+    Tim5 = 4,
+    Tim6 = 5,
+    Tim7 = 6,
+    Tim8 = 7,
+    Tim15 = 8,
+    #[cfg(all(stm32h7, hrtim))]
+    Hrtim1DacTrg1 = 9,
+    #[cfg(all(stm32h7, hrtim))]
+    Hrtim1DacTrg2 = 10,
+    Lptim1 = 11,
+    #[cfg(not(stm32u5))]
+    Lptim2 = 12,
+    #[cfg(stm32u5)]
+    Lptim3 = 12,
+    Exti9 = 13,
+    #[cfg(any(stm32h7ax, stm32h7bx))]
+    /// RM0455 suggests this might be LPTIM2 on DAC1 and LPTIM3 on DAC2,
+    /// but it's probably wrong. Please let us know if you find out.
+    Lptim3 = 14,
+    #[cfg(any(stm32h72x, stm32h73x))]
+    Tim23 = 14,
+    #[cfg(any(stm32h72x, stm32h73x))]
+    Tim24 = 15,
+}
+
+/// Trigger selection for H5.
+#[cfg(stm32h5)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Software = 0,
+    Tim1 = 1,
+    Tim2 = 2,
+    #[cfg(any(stm32h56x, stm32h57x))]
+    Tim4 = 3,
+    #[cfg(stm32h503)]
+    Tim3 = 3,
+    #[cfg(any(stm32h56x, stm32h57x))]
+    Tim5 = 4,
+    Tim6 = 5,
+    Tim7 = 6,
+    #[cfg(any(stm32h56x, stm32h57x))]
+    Tim8 = 7,
+    #[cfg(any(stm32h56x, stm32h57x))]
+    Tim15 = 8,
+    Lptim1 = 11,
+    Lptim2 = 12,
+    Exti9 = 13,
+}
+
+/// Trigger selection for G0.
+#[cfg(stm32g0)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Software = 0,
+    Tim1 = 1,
+    Tim2 = 2,
+    Tim3 = 3,
+    Tim6 = 5,
+    Tim7 = 6,
+    Tim15 = 8,
+    Lptim1 = 11,
+    Lptim2 = 12,
+    Exti9 = 13,
+}
+
+/// Trigger selection for G4.
+#[cfg(stm32g4)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Software = 0,
+    /// * DAC1, DAC2, DAC4: TIM8
+    /// * DAC3: TIM1
+    Dac124Tim8Dac3Tim1 = 1,
+    Tim7 = 2,
+    Tim15 = 3,
+    Tim2 = 4,
+    Tim4 = 5,
+    Exti9 = 6,
+    Tim6 = 7,
+    Tim3 = 8,
+    HrtimDacRstTrg1 = 9,
+    HrtimDacRstTrg2 = 10,
+    HrtimDacRstTrg3 = 11,
+    HrtimDacRstTrg4 = 12,
+    HrtimDacRstTrg5 = 13,
+    HrtimDacRstTrg6 = 14,
+    /// * DAC1, DAC4: HRTIM_DAC_TRG1
+    /// * DAC2: HRTIM_DAC_TRG2
+    /// * DAC3: HRTIM_DAC_TRG3
+    HrtimDacTrg123 = 15,
+}
+
+/// Trigger selection for WL.
+#[cfg(stm32wl)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TriggerSel {
+    Software = 0,
+    Tim1 = 1,
+    Tim2 = 2,
+    Lptim1 = 11,
+    Lptim2 = 12,
+    Lptim3 = 13,
+    Exti9 = 14,
+}
+
+impl TriggerSel {
+    pub fn tsel(&self) -> u8 {
+        *self as u8
+    }
+}

embassy-stm32/src/dma/gpdma.rs

@@ -299,19 +299,15 @@ impl<'a, C: Channel> Transfer<'a, C> {
 
     pub fn request_stop(&mut self) {
         let ch = self.channel.regs().ch(self.channel.num());
-
-        // Disable the channel. Keep the IEs enabled so the irqs still fire.
-        ch.cr().write(|w| {
-            w.set_tcie(true);
-            w.set_useie(true);
-            w.set_dteie(true);
-            w.set_suspie(true);
+        ch.cr().modify(|w| {
+            w.set_susp(true);
         })
     }
 
     pub fn is_running(&mut self) -> bool {
         let ch = self.channel.regs().ch(self.channel.num());
-        !ch.sr().read().tcf()
+        let sr = ch.sr().read();
+        !sr.tcf() && !sr.suspf()
     }
 
     /// Gets the total remaining transfers for the channel

embassy-stm32/src/i2c/mod.rs

@@ -1,11 +1,14 @@
 #![macro_use]
 
+use core::marker::PhantomData;
+
 use crate::interrupt;
 
 #[cfg_attr(i2c_v1, path = "v1.rs")]
 #[cfg_attr(i2c_v2, path = "v2.rs")]
 mod _version;
 pub use _version::*;
+use embassy_sync::waitqueue::AtomicWaker;
 
 use crate::peripherals;
 
@@ -23,6 +26,20 @@ pub enum Error {
 
 pub(crate) mod sealed {
     use super::*;
+
+    pub struct State {
+        #[allow(unused)]
+        pub waker: AtomicWaker,
+    }
+
+    impl State {
+        pub const fn new() -> Self {
+            Self {
+                waker: AtomicWaker::new(),
+            }
+        }
+    }
+
     pub trait Instance: crate::rcc::RccPeripheral {
         fn regs() -> crate::pac::i2c::I2c;
         fn state() -> &'static State;
@@ -30,7 +47,8 @@ pub(crate) mod sealed {
 }
 
 pub trait Instance: sealed::Instance + 'static {
-    type Interrupt: interrupt::typelevel::Interrupt;
+    type EventInterrupt: interrupt::typelevel::Interrupt;
+    type ErrorInterrupt: interrupt::typelevel::Interrupt;
 }
 
 pin_trait!(SclPin, Instance);
@@ -38,21 +56,148 @@ pin_trait!(SdaPin, Instance);
 dma_trait!(RxDma, Instance);
 dma_trait!(TxDma, Instance);
 
-foreach_interrupt!(
-    ($inst:ident, i2c, $block:ident, EV, $irq:ident) => {
+/// Interrupt handler.
+pub struct EventInterruptHandler<T: Instance> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: Instance> interrupt::typelevel::Handler<T::EventInterrupt> for EventInterruptHandler<T> {
+    unsafe fn on_interrupt() {
+        _version::on_interrupt::<T>()
+    }
+}
+
+pub struct ErrorInterruptHandler<T: Instance> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: Instance> interrupt::typelevel::Handler<T::ErrorInterrupt> for ErrorInterruptHandler<T> {
+    unsafe fn on_interrupt() {
+        _version::on_interrupt::<T>()
+    }
+}
+
+foreach_peripheral!(
+    (i2c, $inst:ident) => {
         impl sealed::Instance for peripherals::$inst {
             fn regs() -> crate::pac::i2c::I2c {
                 crate::pac::$inst
             }
 
-            fn state() -> &'static State {
-                static STATE: State = State::new();
+            fn state() -> &'static sealed::State {
+                static STATE: sealed::State = sealed::State::new();
                 &STATE
             }
         }
 
         impl Instance for peripherals::$inst {
-            type Interrupt = crate::interrupt::typelevel::$irq;
+            type EventInterrupt = crate::_generated::peripheral_interrupts::$inst::EV;
+            type ErrorInterrupt = crate::_generated::peripheral_interrupts::$inst::ER;
         }
     };
 );
+
+mod eh02 {
+    use super::*;
+
+    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Read for I2c<'d, T> {
+        type Error = Error;
+
+        fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_read(address, buffer)
+        }
+    }
+
+    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Write for I2c<'d, T> {
+        type Error = Error;
+
+        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
+            self.blocking_write(address, write)
+        }
+    }
+
+    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::WriteRead for I2c<'d, T> {
+        type Error = Error;
+
+        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_write_read(address, write, read)
+        }
+    }
+}
+
+#[cfg(feature = "unstable-traits")]
+mod eh1 {
+    use super::*;
+    use crate::dma::NoDma;
+
+    impl embedded_hal_1::i2c::Error for Error {
+        fn kind(&self) -> embedded_hal_1::i2c::ErrorKind {
+            match *self {
+                Self::Bus => embedded_hal_1::i2c::ErrorKind::Bus,
+                Self::Arbitration => embedded_hal_1::i2c::ErrorKind::ArbitrationLoss,
+                Self::Nack => {
+                    embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Unknown)
+                }
+                Self::Timeout => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::Crc => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::Overrun => embedded_hal_1::i2c::ErrorKind::Overrun,
+                Self::ZeroLengthTransfer => embedded_hal_1::i2c::ErrorKind::Other,
+            }
+        }
+    }
+
+    impl<'d, T: Instance, TXDMA, RXDMA> embedded_hal_1::i2c::ErrorType for I2c<'d, T, TXDMA, RXDMA> {
+        type Error = Error;
+    }
+
+    impl<'d, T: Instance> embedded_hal_1::i2c::I2c for I2c<'d, T, NoDma, NoDma> {
+        fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_read(address, read)
+        }
+
+        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
+            self.blocking_write(address, write)
+        }
+
+        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_write_read(address, write, read)
+        }
+
+        fn transaction(
+            &mut self,
+            _address: u8,
+            _operations: &mut [embedded_hal_1::i2c::Operation<'_>],
+        ) -> Result<(), Self::Error> {
+            todo!();
+        }
+    }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eha {
+    use super::*;
+
+    impl<'d, T: Instance, TXDMA: TxDma<T>, RXDMA: RxDma<T>> embedded_hal_async::i2c::I2c for I2c<'d, T, TXDMA, RXDMA> {
+        async fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
+            self.read(address, read).await
+        }
+
+        async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
+            self.write(address, write).await
+        }
+
+        async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
+            self.write_read(address, write, read).await
+        }
+
+        async fn transaction(
+            &mut self,
+            address: u8,
+            operations: &mut [embedded_hal_1::i2c::Operation<'_>],
+        ) -> Result<(), Self::Error> {
+            let _ = address;
+            let _ = operations;
+            todo!()
+        }
+    }
+}

embassy-stm32/src/i2c/v1.rs

@@ -1,23 +1,33 @@
+use core::future::poll_fn;
 use core::marker::PhantomData;
+use core::task::Poll;
 
 use embassy_embedded_hal::SetConfig;
+use embassy_futures::select::{select, Either};
+use embassy_hal_internal::drop::OnDrop;
 use embassy_hal_internal::{into_ref, PeripheralRef};
 
-use crate::dma::NoDma;
+use super::*;
+use crate::dma::{NoDma, Transfer};
 use crate::gpio::sealed::AFType;
 use crate::gpio::Pull;
-use crate::i2c::{Error, Instance, SclPin, SdaPin};
+use crate::interrupt::typelevel::Interrupt;
 use crate::pac::i2c;
 use crate::time::Hertz;
 use crate::{interrupt, Peripheral};
 
-/// Interrupt handler.
-pub struct InterruptHandler<T: Instance> {
-    _phantom: PhantomData<T>,
-}
-
-impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
-    unsafe fn on_interrupt() {}
+pub unsafe fn on_interrupt<T: Instance>() {
+    let regs = T::regs();
+    // i2c v2 only woke the task on transfer complete interrupts. v1 uses interrupts for a bunch of
+    // other stuff, so we wake the task on every interrupt.
+    T::state().waker.wake();
+    critical_section::with(|_| {
+        // Clear event interrupt flag.
+        regs.cr2().modify(|w| {
+            w.set_itevten(false);
+            w.set_iterren(false);
+        });
+    });
 }
 
 #[non_exhaustive]
@@ -27,14 +37,6 @@ pub struct Config {
     pub scl_pullup: bool,
 }
 
-pub struct State {}
-
-impl State {
-    pub(crate) const fn new() -> Self {
-        Self {}
-    }
-}
-
 pub struct I2c<'d, T: Instance, TXDMA = NoDma, RXDMA = NoDma> {
     phantom: PhantomData<&'d mut T>,
     #[allow(dead_code)]
@@ -48,7 +50,9 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         _peri: impl Peripheral<P = T> + 'd,
         scl: impl Peripheral<P = impl SclPin<T>> + 'd,
         sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
-        _irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
+        _irq: impl interrupt::typelevel::Binding<T::EventInterrupt, EventInterruptHandler<T>>
+            + interrupt::typelevel::Binding<T::ErrorInterrupt, ErrorInterruptHandler<T>>
+            + 'd,
         tx_dma: impl Peripheral<P = TXDMA> + 'd,
         rx_dma: impl Peripheral<P = RXDMA> + 'd,
         freq: Hertz,
@@ -98,6 +102,9 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
             reg.set_pe(true);
         });
 
+        unsafe { T::EventInterrupt::enable() };
+        unsafe { T::ErrorInterrupt::enable() };
+
         Self {
             phantom: PhantomData,
             tx_dma,
@@ -105,40 +112,58 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         }
     }
 
-    fn check_and_clear_error_flags(&self) -> Result<i2c::regs::Sr1, Error> {
+    fn check_and_clear_error_flags() -> Result<i2c::regs::Sr1, Error> {
         // Note that flags should only be cleared once they have been registered. If flags are
         // cleared otherwise, there may be an inherent race condition and flags may be missed.
         let sr1 = T::regs().sr1().read();
 
         if sr1.timeout() {
-            T::regs().sr1().modify(|reg| reg.set_timeout(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_timeout(false);
+            });
             return Err(Error::Timeout);
         }
 
         if sr1.pecerr() {
-            T::regs().sr1().modify(|reg| reg.set_pecerr(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_pecerr(false);
+            });
             return Err(Error::Crc);
         }
 
         if sr1.ovr() {
-            T::regs().sr1().modify(|reg| reg.set_ovr(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_ovr(false);
+            });
             return Err(Error::Overrun);
         }
 
         if sr1.af() {
-            T::regs().sr1().modify(|reg| reg.set_af(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_af(false);
+            });
             return Err(Error::Nack);
         }
 
         if sr1.arlo() {
-            T::regs().sr1().modify(|reg| reg.set_arlo(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_arlo(false);
+            });
             return Err(Error::Arbitration);
         }
 
         // The errata indicates that BERR may be incorrectly detected. It recommends ignoring and
         // clearing the BERR bit instead.
         if sr1.berr() {
-            T::regs().sr1().modify(|reg| reg.set_berr(false));
+            T::regs().sr1().write(|reg| {
+                reg.0 = !0;
+                reg.set_berr(false);
+            });
         }
 
         Ok(sr1)
@@ -157,13 +182,13 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         });
 
         // Wait until START condition was generated
-        while !self.check_and_clear_error_flags()?.start() {
+        while !Self::check_and_clear_error_flags()?.start() {
             check_timeout()?;
         }
 
         // Also wait until signalled we're master and everything is waiting for us
         while {
-            self.check_and_clear_error_flags()?;
+            Self::check_and_clear_error_flags()?;
 
             let sr2 = T::regs().sr2().read();
             !sr2.msl() && !sr2.busy()
@@ -177,7 +202,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         // Wait until address was sent
         // Wait for the address to be acknowledged
         // Check for any I2C errors. If a NACK occurs, the ADDR bit will never be set.
-        while !self.check_and_clear_error_flags()?.addr() {
+        while !Self::check_and_clear_error_flags()?.addr() {
             check_timeout()?;
         }
 
@@ -197,7 +222,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         // Wait until we're ready for sending
         while {
             // Check for any I2C errors. If a NACK occurs, the ADDR bit will never be set.
-            !self.check_and_clear_error_flags()?.txe()
+            !Self::check_and_clear_error_flags()?.txe()
         } {
             check_timeout()?;
         }
@@ -208,7 +233,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         // Wait until byte is transferred
         while {
             // Check for any potential error conditions.
-            !self.check_and_clear_error_flags()?.btf()
+            !Self::check_and_clear_error_flags()?.btf()
         } {
             check_timeout()?;
         }
@@ -219,7 +244,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
     fn recv_byte(&self, check_timeout: impl Fn() -> Result<(), Error>) -> Result<u8, Error> {
         while {
             // Check for any potential error conditions.
-            self.check_and_clear_error_flags()?;
+            Self::check_and_clear_error_flags()?;
 
             !T::regs().sr1().read().rxne()
         } {
@@ -244,7 +269,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
             });
 
             // Wait until START condition was generated
-            while !self.check_and_clear_error_flags()?.start() {
+            while !Self::check_and_clear_error_flags()?.start() {
                 check_timeout()?;
             }
 
@@ -261,7 +286,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
 
             // Wait until address was sent
             // Wait for the address to be acknowledged
-            while !self.check_and_clear_error_flags()?.addr() {
+            while !Self::check_and_clear_error_flags()?.addr() {
                 check_timeout()?;
             }
 
@@ -336,6 +361,356 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
     pub fn blocking_write_read(&mut self, addr: u8, write: &[u8], read: &mut [u8]) -> Result<(), Error> {
         self.blocking_write_read_timeout(addr, write, read, || Ok(()))
     }
+
+    // Async
+
+    #[inline] // pretty sure this should always be inlined
+    fn enable_interrupts() -> () {
+        T::regs().cr2().modify(|w| {
+            w.set_iterren(true);
+            w.set_itevten(true);
+        });
+    }
+
+    async fn write_with_stop(&mut self, address: u8, write: &[u8], send_stop: bool) -> Result<(), Error>
+    where
+        TXDMA: crate::i2c::TxDma<T>,
+    {
+        let dma_transfer = unsafe {
+            let regs = T::regs();
+            regs.cr2().modify(|w| {
+                // DMA mode can be enabled for transmission by setting the DMAEN bit in the I2C_CR2 register.
+                w.set_dmaen(true);
+                w.set_itbufen(false);
+            });
+            // Set the I2C_DR register address in the DMA_SxPAR register. The data will be moved to this address from the memory after each TxE event.
+            let dst = regs.dr().as_ptr() as *mut u8;
+
+            let ch = &mut self.tx_dma;
+            let request = ch.request();
+            Transfer::new_write(ch, request, write, dst, Default::default())
+        };
+
+        let on_drop = OnDrop::new(|| {
+            let regs = T::regs();
+            regs.cr2().modify(|w| {
+                w.set_dmaen(false);
+                w.set_iterren(false);
+                w.set_itevten(false);
+            })
+        });
+
+        Self::enable_interrupts();
+
+        // Send a START condition
+        T::regs().cr1().modify(|reg| {
+            reg.set_start(true);
+        });
+
+        let state = T::state();
+
+        // Wait until START condition was generated
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(sr1) => {
+                    if sr1.start() {
+                        Poll::Ready(Ok(()))
+                    } else {
+                        Poll::Pending
+                    }
+                }
+            }
+        })
+        .await?;
+
+        // Also wait until signalled we're master and everything is waiting for us
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(_) => {
+                    let sr2 = T::regs().sr2().read();
+                    if !sr2.msl() && !sr2.busy() {
+                        Poll::Pending
+                    } else {
+                        Poll::Ready(Ok(()))
+                    }
+                }
+            }
+        })
+        .await?;
+
+        // Set up current address, we're trying to talk to
+        Self::enable_interrupts();
+        T::regs().dr().write(|reg| reg.set_dr(address << 1));
+
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(sr1) => {
+                    if sr1.addr() {
+                        // Clear the ADDR condition by reading SR2.
+                        T::regs().sr2().read();
+                        Poll::Ready(Ok(()))
+                    } else {
+                        Poll::Pending
+                    }
+                }
+            }
+        })
+        .await?;
+        Self::enable_interrupts();
+        let poll_error = poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                // Unclear why the Err turbofish is necessary here? The compiler didn’t require it in the other
+                // identical poll_fn check_and_clear matches.
+                Err(e) => Poll::Ready(Err::<T, Error>(e)),
+                Ok(_) => Poll::Pending,
+            }
+        });
+
+        // Wait for either the DMA transfer to successfully finish, or an I2C error to occur.
+        match select(dma_transfer, poll_error).await {
+            Either::Second(Err(e)) => Err(e),
+            _ => Ok(()),
+        }?;
+
+        // The I2C transfer itself will take longer than the DMA transfer, so wait for that to finish too.
+
+        // 18.3.8 “Master transmitter: In the interrupt routine after the EOT interrupt, disable DMA
+        // requests then wait for a BTF event before programming the Stop condition.”
+
+        // TODO: If this has to be done “in the interrupt routine after the EOT interrupt”, where to put it?
+        T::regs().cr2().modify(|w| {
+            w.set_dmaen(false);
+        });
+
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(sr1) => {
+                    if sr1.btf() {
+                        if send_stop {
+                            T::regs().cr1().modify(|w| {
+                                w.set_stop(true);
+                            });
+                        }
+
+                        Poll::Ready(Ok(()))
+                    } else {
+                        Poll::Pending
+                    }
+                }
+            }
+        })
+        .await?;
+
+        drop(on_drop);
+
+        // Fallthrough is success
+        Ok(())
+    }
+
+    pub async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Error>
+    where
+        TXDMA: crate::i2c::TxDma<T>,
+    {
+        self.write_with_stop(address, write, true).await?;
+
+        // Wait for STOP condition to transmit.
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            T::state().waker.register(cx.waker());
+            // TODO: error interrupts are enabled here, should we additional check for and return errors?
+            if T::regs().cr1().read().stop() {
+                Poll::Pending
+            } else {
+                Poll::Ready(Ok(()))
+            }
+        })
+        .await?;
+
+        Ok(())
+    }
+
+    pub async fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Error>
+    where
+        RXDMA: crate::i2c::RxDma<T>,
+    {
+        let state = T::state();
+        let buffer_len = buffer.len();
+
+        let dma_transfer = unsafe {
+            let regs = T::regs();
+            regs.cr2().modify(|w| {
+                // DMA mode can be enabled for transmission by setting the DMAEN bit in the I2C_CR2 register.
+                w.set_itbufen(false);
+                w.set_dmaen(true);
+            });
+            // Set the I2C_DR register address in the DMA_SxPAR register. The data will be moved to this address from the memory after each TxE event.
+            let src = regs.dr().as_ptr() as *mut u8;
+
+            let ch = &mut self.rx_dma;
+            let request = ch.request();
+            Transfer::new_read(ch, request, src, buffer, Default::default())
+        };
+
+        let on_drop = OnDrop::new(|| {
+            let regs = T::regs();
+            regs.cr2().modify(|w| {
+                w.set_dmaen(false);
+                w.set_iterren(false);
+                w.set_itevten(false);
+            })
+        });
+
+        Self::enable_interrupts();
+
+        // Send a START condition and set ACK bit
+        T::regs().cr1().modify(|reg| {
+            reg.set_start(true);
+            reg.set_ack(true);
+        });
+
+        // Wait until START condition was generated
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(sr1) => {
+                    if sr1.start() {
+                        Poll::Ready(Ok(()))
+                    } else {
+                        Poll::Pending
+                    }
+                }
+            }
+        })
+        .await?;
+
+        // Also wait until signalled we're master and everything is waiting for us
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            // blocking read didn’t have a check_and_clear call here, but blocking write did so
+            // I’m adding it here in case that was an oversight.
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(_) => {
+                    let sr2 = T::regs().sr2().read();
+                    if !sr2.msl() && !sr2.busy() {
+                        Poll::Pending
+                    } else {
+                        Poll::Ready(Ok(()))
+                    }
+                }
+            }
+        })
+        .await?;
+
+        // Set up current address, we're trying to talk to
+        T::regs().dr().write(|reg| reg.set_dr((address << 1) + 1));
+
+        // Wait for the address to be acknowledged
+
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err(e)),
+                Ok(sr1) => {
+                    if sr1.addr() {
+                        // 18.3.8: When a single byte must be received: the NACK must be programmed during EV6
+                        // event, i.e. program ACK=0 when ADDR=1, before clearing ADDR flag.
+                        if buffer_len == 1 {
+                            T::regs().cr1().modify(|w| {
+                                w.set_ack(false);
+                            });
+                        }
+                        Poll::Ready(Ok(()))
+                    } else {
+                        Poll::Pending
+                    }
+                }
+            }
+        })
+        .await?;
+
+        // Clear ADDR condition by reading SR2
+        T::regs().sr2().read();
+
+        // 18.3.8: When a single byte must be received: [snip] Then the
+        // user can program the STOP condition either after clearing ADDR flag, or in the
+        // DMA Transfer Complete interrupt routine.
+        if buffer_len == 1 {
+            T::regs().cr1().modify(|w| {
+                w.set_stop(true);
+            });
+        } else {
+            // If, in the I2C_CR2 register, the LAST bit is set, I2C
+            // automatically sends a NACK after the next byte following EOT_1. The user can
+            // generate a Stop condition in the DMA Transfer Complete interrupt routine if enabled.
+            T::regs().cr2().modify(|w| {
+                w.set_last(true);
+            })
+        }
+
+        // Wait for bytes to be received, or an error to occur.
+        Self::enable_interrupts();
+        let poll_error = poll_fn(|cx| {
+            state.waker.register(cx.waker());
+
+            match Self::check_and_clear_error_flags() {
+                Err(e) => Poll::Ready(Err::<T, Error>(e)),
+                _ => Poll::Pending,
+            }
+        });
+
+        match select(dma_transfer, poll_error).await {
+            Either::Second(Err(e)) => Err(e),
+            _ => Ok(()),
+        }?;
+
+        // Wait for the STOP to be sent (STOP bit cleared).
+        Self::enable_interrupts();
+        poll_fn(|cx| {
+            state.waker.register(cx.waker());
+            // TODO: error interrupts are enabled here, should we additional check for and return errors?
+            if T::regs().cr1().read().stop() {
+                Poll::Pending
+            } else {
+                Poll::Ready(Ok(()))
+            }
+        })
+        .await?;
+        drop(on_drop);
+
+        // Fallthrough is success
+        Ok(())
+    }
+
+    pub async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Error>
+    where
+        RXDMA: crate::i2c::RxDma<T>,
+        TXDMA: crate::i2c::TxDma<T>,
+    {
+        self.write_with_stop(address, write, false).await?;
+        self.read(address, read).await
+    }
 }
 
 impl<'d, T: Instance, TXDMA, RXDMA> Drop for I2c<'d, T, TXDMA, RXDMA> {
@@ -344,77 +719,6 @@ impl<'d, T: Instance, TXDMA, RXDMA> Drop for I2c<'d, T, TXDMA, RXDMA> {
     }
 }
 
-impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Read for I2c<'d, T> {
-    type Error = Error;
-
-    fn read(&mut self, addr: u8, read: &mut [u8]) -> Result<(), Self::Error> {
-        self.blocking_read(addr, read)
-    }
-}
-
-impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Write for I2c<'d, T> {
-    type Error = Error;
-
-    fn write(&mut self, addr: u8, write: &[u8]) -> Result<(), Self::Error> {
-        self.blocking_write(addr, write)
-    }
-}
-
-impl<'d, T: Instance> embedded_hal_02::blocking::i2c::WriteRead for I2c<'d, T> {
-    type Error = Error;
-
-    fn write_read(&mut self, addr: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
-        self.blocking_write_read(addr, write, read)
-    }
-}
-
-#[cfg(feature = "unstable-traits")]
-mod eh1 {
-    use super::*;
-
-    impl embedded_hal_1::i2c::Error for Error {
-        fn kind(&self) -> embedded_hal_1::i2c::ErrorKind {
-            match *self {
-                Self::Bus => embedded_hal_1::i2c::ErrorKind::Bus,
-                Self::Arbitration => embedded_hal_1::i2c::ErrorKind::ArbitrationLoss,
-                Self::Nack => {
-                    embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Unknown)
-                }
-                Self::Timeout => embedded_hal_1::i2c::ErrorKind::Other,
-                Self::Crc => embedded_hal_1::i2c::ErrorKind::Other,
-                Self::Overrun => embedded_hal_1::i2c::ErrorKind::Overrun,
-                Self::ZeroLengthTransfer => embedded_hal_1::i2c::ErrorKind::Other,
-            }
-        }
-    }
-
-    impl<'d, T: Instance> embedded_hal_1::i2c::ErrorType for I2c<'d, T> {
-        type Error = Error;
-    }
-
-    impl<'d, T: Instance> embedded_hal_1::i2c::I2c for I2c<'d, T> {
-        fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_read(address, read)
-        }
-
-        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
-            self.blocking_write(address, write)
-        }
-
-        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_write_read(address, write, read)
-        }
-
-        fn transaction(
-            &mut self,
-            _address: u8,
-            _operations: &mut [embedded_hal_1::i2c::Operation<'_>],
-        ) -> Result<(), Self::Error> {
-            todo!();
-        }
-    }
-}
-
 enum Mode {
     Fast,
     Standard,

embassy-stm32/src/i2c/v2.rs

@@ -1,48 +1,51 @@
 use core::cmp;
-#[cfg(feature = "time")]
 use core::future::poll_fn;
-use core::marker::PhantomData;
-#[cfg(feature = "time")]
 use core::task::Poll;
 
 use embassy_embedded_hal::SetConfig;
-#[cfg(feature = "time")]
 use embassy_hal_internal::drop::OnDrop;
 use embassy_hal_internal::{into_ref, PeripheralRef};
-use embassy_sync::waitqueue::AtomicWaker;
 #[cfg(feature = "time")]
 use embassy_time::{Duration, Instant};
 
-use crate::dma::NoDma;
-#[cfg(feature = "time")]
-use crate::dma::Transfer;
+use super::*;
+use crate::dma::{NoDma, Transfer};
 use crate::gpio::sealed::AFType;
 use crate::gpio::Pull;
-use crate::i2c::{Error, Instance, SclPin, SdaPin};
 use crate::interrupt::typelevel::Interrupt;
 use crate::pac::i2c;
 use crate::time::Hertz;
 use crate::{interrupt, Peripheral};
 
-/// Interrupt handler.
-pub struct InterruptHandler<T: Instance> {
-    _phantom: PhantomData<T>,
+#[cfg(feature = "time")]
+fn timeout_fn(timeout: Duration) -> impl Fn() -> Result<(), Error> {
+    let deadline = Instant::now() + timeout;
+    move || {
+        if Instant::now() > deadline {
+            Err(Error::Timeout)
+        } else {
+            Ok(())
+        }
+    }
 }
 
-impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
-    unsafe fn on_interrupt() {
-        let regs = T::regs();
-        let isr = regs.isr().read();
+#[cfg(not(feature = "time"))]
+pub fn no_timeout_fn() -> impl Fn() -> Result<(), Error> {
+    move || Ok(())
+}
 
-        if isr.tcr() || isr.tc() {
-            T::state().waker.wake();
-        }
-        // The flag can only be cleared by writting to nbytes, we won't do that here, so disable
-        // the interrupt
-        critical_section::with(|_| {
-            regs.cr1().modify(|w| w.set_tcie(false));
-        });
+pub unsafe fn on_interrupt<T: Instance>() {
+    let regs = T::regs();
+    let isr = regs.isr().read();
+
+    if isr.tcr() || isr.tc() {
+        T::state().waker.wake();
     }
+    // The flag can only be cleared by writting to nbytes, we won't do that here, so disable
+    // the interrupt
+    critical_section::with(|_| {
+        regs.cr1().modify(|w| w.set_tcie(false));
+    });
 }
 
 #[non_exhaustive]
@@ -65,18 +68,6 @@ impl Default for Config {
     }
 }
 
-pub struct State {
-    waker: AtomicWaker,
-}
-
-impl State {
-    pub(crate) const fn new() -> Self {
-        Self {
-            waker: AtomicWaker::new(),
-        }
-    }
-}
-
 pub struct I2c<'d, T: Instance, TXDMA = NoDma, RXDMA = NoDma> {
     _peri: PeripheralRef<'d, T>,
     #[allow(dead_code)]
@@ -92,7 +83,9 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         peri: impl Peripheral<P = T> + 'd,
         scl: impl Peripheral<P = impl SclPin<T>> + 'd,
         sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
-        _irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
+        _irq: impl interrupt::typelevel::Binding<T::EventInterrupt, EventInterruptHandler<T>>
+            + interrupt::typelevel::Binding<T::ErrorInterrupt, ErrorInterruptHandler<T>>
+            + 'd,
         tx_dma: impl Peripheral<P = TXDMA> + 'd,
         rx_dma: impl Peripheral<P = RXDMA> + 'd,
         freq: Hertz,
@@ -138,8 +131,8 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
             reg.set_pe(true);
         });
 
-        T::Interrupt::unpend();
-        unsafe { T::Interrupt::enable() };
+        unsafe { T::EventInterrupt::enable() };
+        unsafe { T::ErrorInterrupt::enable() };
 
         Self {
             _peri: peri,
@@ -260,21 +253,12 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
     }
 
     fn flush_txdr(&self) {
-        //if $i2c.isr.read().txis().bit_is_set() {
-        //$i2c.txdr.write(|w| w.txdata().bits(0));
-        //}
-
         if T::regs().isr().read().txis() {
             T::regs().txdr().write(|w| w.set_txdata(0));
         }
         if !T::regs().isr().read().txe() {
             T::regs().isr().modify(|w| w.set_txe(true))
         }
-
-        // If TXDR is not flagged as empty, write 1 to flush it
-        //if $i2c.isr.read().txe().is_not_empty() {
-        //$i2c.isr.write(|w| w.txe().set_bit());
-        //}
     }
 
     fn wait_txe(&self, check_timeout: impl Fn() -> Result<(), Error>) -> Result<(), Error> {
@@ -437,7 +421,6 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         result
     }
 
-    #[cfg(feature = "time")]
     async fn write_dma_internal(
         &mut self,
         address: u8,
@@ -528,7 +511,6 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         Ok(())
     }
 
-    #[cfg(feature = "time")]
     async fn read_dma_internal(
         &mut self,
         address: u8,
@@ -610,42 +592,38 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
 
     // =========================
     //  Async public API
-
     #[cfg(feature = "time")]
     pub async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Error>
-    where
-        TXDMA: crate::i2c::TxDma<T>,
-    {
-        self.write_timeout(address, write, self.timeout).await
-    }
-
-    #[cfg(feature = "time")]
-    pub async fn write_timeout(&mut self, address: u8, write: &[u8], timeout: Duration) -> Result<(), Error>
     where
         TXDMA: crate::i2c::TxDma<T>,
     {
         if write.is_empty() {
-            self.write_internal(address, write, true, timeout_fn(timeout))
+            self.write_internal(address, write, true, timeout_fn(self.timeout))
         } else {
             embassy_time::with_timeout(
-                timeout,
-                self.write_dma_internal(address, write, true, true, timeout_fn(timeout)),
+                self.timeout,
+                self.write_dma_internal(address, write, true, true, timeout_fn(self.timeout)),
             )
             .await
             .unwrap_or(Err(Error::Timeout))
         }
     }
 
-    #[cfg(feature = "time")]
-    pub async fn write_vectored(&mut self, address: u8, write: &[&[u8]]) -> Result<(), Error>
+    #[cfg(not(feature = "time"))]
+    pub async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Error>
     where
         TXDMA: crate::i2c::TxDma<T>,
     {
-        self.write_vectored_timeout(address, write, self.timeout).await
+        if write.is_empty() {
+            self.write_internal(address, write, true, no_timeout_fn())
+        } else {
+            self.write_dma_internal(address, write, true, true, no_timeout_fn())
+                .await
+        }
     }
 
     #[cfg(feature = "time")]
-    pub async fn write_vectored_timeout(&mut self, address: u8, write: &[&[u8]], timeout: Duration) -> Result<(), Error>
+    pub async fn write_vectored(&mut self, address: u8, write: &[&[u8]]) -> Result<(), Error>
     where
         TXDMA: crate::i2c::TxDma<T>,
     {
@@ -661,8 +639,8 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
             let is_last = next.is_none();
 
             embassy_time::with_timeout(
-                timeout,
-                self.write_dma_internal(address, c, first, is_last, timeout_fn(timeout)),
+                self.timeout,
+                self.write_dma_internal(address, c, first, is_last, timeout_fn(self.timeout)),
             )
             .await
             .unwrap_or(Err(Error::Timeout))?;
@@ -672,66 +650,79 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         Ok(())
     }
 
+    #[cfg(not(feature = "time"))]
+    pub async fn write_vectored(&mut self, address: u8, write: &[&[u8]]) -> Result<(), Error>
+    where
+        TXDMA: crate::i2c::TxDma<T>,
+    {
+        if write.is_empty() {
+            return Err(Error::ZeroLengthTransfer);
+        }
+        let mut iter = write.iter();
+
+        let mut first = true;
+        let mut current = iter.next();
+        while let Some(c) = current {
+            let next = iter.next();
+            let is_last = next.is_none();
+
+            self.write_dma_internal(address, c, first, is_last, no_timeout_fn())
+                .await?;
+            first = false;
+            current = next;
+        }
+        Ok(())
+    }
+
     #[cfg(feature = "time")]
     pub async fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Error>
     where
         RXDMA: crate::i2c::RxDma<T>,
     {
-        self.read_timeout(address, buffer, self.timeout).await
+        if buffer.is_empty() {
+            self.read_internal(address, buffer, false, timeout_fn(self.timeout))
+        } else {
+            embassy_time::with_timeout(
+                self.timeout,
+                self.read_dma_internal(address, buffer, false, timeout_fn(self.timeout)),
+            )
+            .await
+            .unwrap_or(Err(Error::Timeout))
+        }
     }
 
-    #[cfg(feature = "time")]
-    pub async fn read_timeout(&mut self, address: u8, buffer: &mut [u8], timeout: Duration) -> Result<(), Error>
+    #[cfg(not(feature = "time"))]
+    pub async fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Error>
     where
         RXDMA: crate::i2c::RxDma<T>,
     {
         if buffer.is_empty() {
-            self.read_internal(address, buffer, false, timeout_fn(timeout))
+            self.read_internal(address, buffer, false, no_timeout_fn())
         } else {
-            embassy_time::with_timeout(
-                timeout,
-                self.read_dma_internal(address, buffer, false, timeout_fn(timeout)),
-            )
-            .await
-            .unwrap_or(Err(Error::Timeout))
+            self.read_dma_internal(address, buffer, false, no_timeout_fn()).await
         }
     }
 
     #[cfg(feature = "time")]
     pub async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Error>
-    where
-        TXDMA: super::TxDma<T>,
-        RXDMA: super::RxDma<T>,
-    {
-        self.write_read_timeout(address, write, read, self.timeout).await
-    }
-
-    #[cfg(feature = "time")]
-    pub async fn write_read_timeout(
-        &mut self,
-        address: u8,
-        write: &[u8],
-        read: &mut [u8],
-        timeout: Duration,
-    ) -> Result<(), Error>
     where
         TXDMA: super::TxDma<T>,
         RXDMA: super::RxDma<T>,
     {
         let start_instant = Instant::now();
-        let check_timeout = timeout_fn(timeout);
+        let check_timeout = timeout_fn(self.timeout);
         if write.is_empty() {
             self.write_internal(address, write, false, &check_timeout)?;
         } else {
             embassy_time::with_timeout(
-                timeout,
+                self.timeout,
                 self.write_dma_internal(address, write, true, true, &check_timeout),
             )
             .await
             .unwrap_or(Err(Error::Timeout))?;
         }
 
-        let time_left_until_timeout = timeout - Instant::now().duration_since(start_instant);
+        let time_left_until_timeout = self.timeout - Instant::now().duration_since(start_instant);
 
         if read.is_empty() {
             self.read_internal(address, read, true, &check_timeout)?;
@@ -747,6 +738,28 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         Ok(())
     }
 
+    #[cfg(not(feature = "time"))]
+    pub async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Error>
+    where
+        TXDMA: super::TxDma<T>,
+        RXDMA: super::RxDma<T>,
+    {
+        let no_timeout = no_timeout_fn();
+        if write.is_empty() {
+            self.write_internal(address, write, false, &no_timeout)?;
+        } else {
+            self.write_dma_internal(address, write, true, true, &no_timeout).await?;
+        }
+
+        if read.is_empty() {
+            self.read_internal(address, read, true, &no_timeout)?;
+        } else {
+            self.read_dma_internal(address, read, true, &no_timeout).await?;
+        }
+
+        Ok(())
+    }
+
     // =========================
     //  Blocking public API
 
@@ -955,35 +968,6 @@ impl<'d, T: Instance, TXDMA, RXDMA> Drop for I2c<'d, T, TXDMA, RXDMA> {
     }
 }
 
-#[cfg(feature = "time")]
-mod eh02 {
-    use super::*;
-
-    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Read for I2c<'d, T> {
-        type Error = Error;
-
-        fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_read(address, buffer)
-        }
-    }
-
-    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Write for I2c<'d, T> {
-        type Error = Error;
-
-        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
-            self.blocking_write(address, write)
-        }
-    }
-
-    impl<'d, T: Instance> embedded_hal_02::blocking::i2c::WriteRead for I2c<'d, T> {
-        type Error = Error;
-
-        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_write_read(address, write, read)
-        }
-    }
-}
-
 /// I2C Stop Configuration
 ///
 /// Peripheral options for generating the STOP condition
@@ -1108,83 +1092,6 @@ impl Timings {
     }
 }
 
-#[cfg(feature = "unstable-traits")]
-mod eh1 {
-    use super::*;
-
-    impl embedded_hal_1::i2c::Error for Error {
-        fn kind(&self) -> embedded_hal_1::i2c::ErrorKind {
-            match *self {
-                Self::Bus => embedded_hal_1::i2c::ErrorKind::Bus,
-                Self::Arbitration => embedded_hal_1::i2c::ErrorKind::ArbitrationLoss,
-                Self::Nack => {
-                    embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Unknown)
-                }
-                Self::Timeout => embedded_hal_1::i2c::ErrorKind::Other,
-                Self::Crc => embedded_hal_1::i2c::ErrorKind::Other,
-                Self::Overrun => embedded_hal_1::i2c::ErrorKind::Overrun,
-                Self::ZeroLengthTransfer => embedded_hal_1::i2c::ErrorKind::Other,
-            }
-        }
-    }
-
-    impl<'d, T: Instance, TXDMA, RXDMA> embedded_hal_1::i2c::ErrorType for I2c<'d, T, TXDMA, RXDMA> {
-        type Error = Error;
-    }
-
-    impl<'d, T: Instance> embedded_hal_1::i2c::I2c for I2c<'d, T, NoDma, NoDma> {
-        fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_read(address, read)
-        }
-
-        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
-            self.blocking_write(address, write)
-        }
-
-        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
-            self.blocking_write_read(address, write, read)
-        }
-
-        fn transaction(
-            &mut self,
-            _address: u8,
-            _operations: &mut [embedded_hal_1::i2c::Operation<'_>],
-        ) -> Result<(), Self::Error> {
-            todo!();
-        }
-    }
-}
-
-#[cfg(all(feature = "unstable-traits", feature = "nightly", feature = "time"))]
-mod eha {
-    use super::super::{RxDma, TxDma};
-    use super::*;
-
-    impl<'d, T: Instance, TXDMA: TxDma<T>, RXDMA: RxDma<T>> embedded_hal_async::i2c::I2c for I2c<'d, T, TXDMA, RXDMA> {
-        async fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
-            self.read(address, read).await
-        }
-
-        async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
-            self.write(address, write).await
-        }
-
-        async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
-            self.write_read(address, write, read).await
-        }
-
-        async fn transaction(
-            &mut self,
-            address: u8,
-            operations: &mut [embedded_hal_1::i2c::Operation<'_>],
-        ) -> Result<(), Self::Error> {
-            let _ = address;
-            let _ = operations;
-            todo!()
-        }
-    }
-}
-
 impl<'d, T: Instance> SetConfig for I2c<'d, T> {
     type Config = Hertz;
     type ConfigError = ();
@@ -1201,15 +1108,3 @@ impl<'d, T: Instance> SetConfig for I2c<'d, T> {
         Ok(())
     }
 }
-
-#[cfg(feature = "time")]
-fn timeout_fn(timeout: Duration) -> impl Fn() -> Result<(), Error> {
-    let deadline = Instant::now() + timeout;
-    move || {
-        if Instant::now() > deadline {
-            Err(Error::Timeout)
-        } else {
-            Ok(())
-        }
-    }
-}

embassy-stm32/src/opamp.rs

@@ -31,12 +31,9 @@ impl From<OpAmpSpeed> for crate::pac::opamp::vals::OpampCsrOpahsm {
 
 /// OpAmp external outputs, wired to a GPIO pad.
 ///
-/// The GPIO output pad is held by this struct to ensure it cannot be used elsewhere.
-///
 /// This struct can also be used as an ADC input.
-pub struct OpAmpOutput<'d, 'p, T: Instance, P: OutputPin<T>> {
+pub struct OpAmpOutput<'d, T: Instance> {
     _inner: &'d OpAmp<'d, T>,
-    _output: &'p mut P,
 }
 
 /// OpAmp internal outputs, wired directly to ADC inputs.
@@ -54,19 +51,12 @@ pub struct OpAmp<'d, T: Instance> {
 impl<'d, T: Instance> OpAmp<'d, T> {
     /// Create a new driver instance.
     ///
-    /// Enables the OpAmp and configures the speed, but
-    /// does not set any other configuration.
+    /// Does not enable the opamp, but does set the speed mode on some families.
     pub fn new(opamp: impl Peripheral<P = T> + 'd, #[cfg(opamp_g4)] speed: OpAmpSpeed) -> Self {
         into_ref!(opamp);
 
-        #[cfg(opamp_f3)]
-        T::regs().opampcsr().modify(|w| {
-            w.set_opampen(true);
-        });
-
         #[cfg(opamp_g4)]
         T::regs().opamp_csr().modify(|w| {
-            w.set_opaen(true);
             w.set_opahsm(speed.into());
         });
 
@@ -74,24 +64,23 @@ impl<'d, T: Instance> OpAmp<'d, T> {
     }
 
     /// Configure the OpAmp as a buffer for the provided input pin,
-    /// outputting to the provided output pin.
+    /// outputting to the provided output pin, and enable the opamp.
     ///
     /// The input pin is configured for analogue mode but not consumed,
     /// so it may subsequently be used for ADC or comparator inputs.
     ///
     /// The output pin is held within the returned [`OpAmpOutput`] struct,
     /// preventing it being used elsewhere. The `OpAmpOutput` can then be
-    /// directly used as an ADC input.
-    pub fn buffer_ext<'a, 'b, IP, OP>(
-        &'a mut self,
-        in_pin: &IP,
-        out_pin: &'b mut OP,
+    /// directly used as an ADC input. The opamp will be disabled when the
+    /// [`OpAmpOutput`] is dropped.
+    pub fn buffer_ext(
+        &'d mut self,
+        in_pin: impl Peripheral<P = impl NonInvertingPin<T> + crate::gpio::sealed::Pin>,
+        out_pin: impl Peripheral<P = impl OutputPin<T> + crate::gpio::sealed::Pin> + 'd,
         gain: OpAmpGain,
-    ) -> OpAmpOutput<'a, 'b, T, OP>
-    where
-        IP: NonInvertingPin<T> + crate::gpio::sealed::Pin,
-        OP: OutputPin<T> + crate::gpio::sealed::Pin,
-    {
+    ) -> OpAmpOutput<'d, T> {
+        into_ref!(in_pin);
+        into_ref!(out_pin);
         in_pin.set_as_analog();
         out_pin.set_as_analog();
 
@@ -122,24 +111,24 @@ impl<'d, T: Instance> OpAmp<'d, T> {
             w.set_opaen(true);
         });
 
-        OpAmpOutput {
-            _inner: self,
-            _output: out_pin,
-        }
+        OpAmpOutput { _inner: self }
     }
 
     /// Configure the OpAmp as a buffer for the provided input pin,
-    /// with the output only used internally.
+    /// with the output only used internally, and enable the opamp.
     ///
     /// The input pin is configured for analogue mode but not consumed,
     /// so it may be subsequently used for ADC or comparator inputs.
     ///
     /// The returned `OpAmpInternalOutput` struct may be used as an ADC input.
+    /// The opamp output will be disabled when it is dropped.
     #[cfg(opamp_g4)]
-    pub fn buffer_int<'a, P>(&'a mut self, pin: &P, gain: OpAmpGain) -> OpAmpInternalOutput<'a, T>
-    where
-        P: NonInvertingPin<T> + crate::gpio::sealed::Pin,
-    {
+    pub fn buffer_int(
+        &'d mut self,
+        pin: impl Peripheral<P = impl NonInvertingPin<T> + crate::gpio::sealed::Pin>,
+        gain: OpAmpGain,
+    ) -> OpAmpInternalOutput<'d, T> {
+        into_ref!(pin);
         pin.set_as_analog();
 
         let (vm_sel, pga_gain) = match gain {
@@ -163,7 +152,21 @@ impl<'d, T: Instance> OpAmp<'d, T> {
     }
 }
 
-impl<'d, T: Instance> Drop for OpAmp<'d, T> {
+impl<'d, T: Instance> Drop for OpAmpOutput<'d, T> {
+    fn drop(&mut self) {
+        #[cfg(opamp_f3)]
+        T::regs().opampcsr().modify(|w| {
+            w.set_opampen(false);
+        });
+
+        #[cfg(opamp_g4)]
+        T::regs().opamp_csr().modify(|w| {
+            w.set_opaen(false);
+        });
+    }
+}
+
+impl<'d, T: Instance> Drop for OpAmpInternalOutput<'d, T> {
     fn drop(&mut self) {
         #[cfg(opamp_f3)]
         T::regs().opampcsr().modify(|w| {
@@ -203,16 +206,16 @@ macro_rules! impl_opamp_external_output {
     ($inst:ident, $adc:ident, $ch:expr) => {
         foreach_adc!(
             ($adc, $common_inst:ident, $adc_clock:ident) => {
-                impl<'d, 'p, P: OutputPin<crate::peripherals::$inst>> crate::adc::sealed::AdcPin<crate::peripherals::$adc>
-                    for OpAmpOutput<'d, 'p, crate::peripherals::$inst, P>
+                impl<'d> crate::adc::sealed::AdcPin<crate::peripherals::$adc>
+                    for OpAmpOutput<'d, crate::peripherals::$inst>
                 {
                     fn channel(&self) -> u8 {
                         $ch
                     }
                 }
 
-                impl<'d, 'p, P: OutputPin<crate::peripherals::$inst>> crate::adc::AdcPin<crate::peripherals::$adc>
-                    for OpAmpOutput<'d, 'p, crate::peripherals::$inst, P>
+                impl<'d> crate::adc::AdcPin<crate::peripherals::$adc>
+                    for OpAmpOutput<'d, crate::peripherals::$inst>
                 {
                 }
             };

embassy-stm32/src/rcc/f3.rs

@@ -346,10 +346,7 @@ fn calc_pll(config: &Config, Hertz(sysclk): Hertz) -> (Hertz, PllConfig) {
         None => {
             cfg_if::cfg_if! {
                 // For some chips PREDIV is always two, and cannot be changed
-                if #[cfg(any(
-                        stm32f302xd, stm32f302xe, stm32f303xd,
-                        stm32f303xe, stm32f398xe
-                    ))] {
+                if #[cfg(any(flashsize_d, flashsize_e))] {
                     let (multiplier, divisor) = get_mul_div(sysclk, HSI_FREQ.0);
                     (
                         Hertz((HSI_FREQ.0 / divisor) * multiplier),

embassy-stm32/src/rcc/h.rs

@@ -168,7 +168,12 @@ impl Default for Config {
             apb4_pre: APBPrescaler::DIV1,
 
             per_clock_source: PerClockSource::HSI,
-            adc_clock_source: AdcClockSource::from_bits(0), // PLL2_P on H7, HCLK on H5
+
+            #[cfg(stm32h5)]
+            adc_clock_source: AdcClockSource::HCLK1,
+            #[cfg(stm32h7)]
+            adc_clock_source: AdcClockSource::PER,
+
             timer_prescaler: TimerPrescaler::DefaultX2,
             voltage_scale: VoltageScale::Scale0,
             ls: Default::default(),

embassy-stm32/src/sai/mod.rs

@@ -207,27 +207,40 @@ impl Protocol {
 }
 
 #[derive(Copy, Clone, PartialEq)]
-pub enum SyncEnable {
-    Asynchronous,
+pub enum SyncInput {
+    /// Not synced to any other SAI unit.
+    None,
     /// Syncs with the other A/B sub-block within the SAI unit
     Internal,
-    /// Syncs with a sub-block in the other SAI unit - use set_sync_output() and set_sync_input()
-    #[cfg(any(sai_v4))]
-    External,
+    /// Syncs with a sub-block in the other SAI unit
+    #[cfg(sai_v4)]
+    External(SyncInputInstance),
 }
 
-impl SyncEnable {
-    #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
+impl SyncInput {
     pub const fn syncen(&self) -> vals::Syncen {
         match self {
-            SyncEnable::Asynchronous => vals::Syncen::ASYNCHRONOUS,
-            SyncEnable::Internal => vals::Syncen::INTERNAL,
+            SyncInput::None => vals::Syncen::ASYNCHRONOUS,
+            SyncInput::Internal => vals::Syncen::INTERNAL,
             #[cfg(any(sai_v4))]
-            SyncEnable::External => vals::Syncen::EXTERNAL,
+            SyncInput::External(_) => vals::Syncen::EXTERNAL,
         }
     }
 }
 
+#[cfg(sai_v4)]
+#[derive(Copy, Clone, PartialEq)]
+pub enum SyncInputInstance {
+    #[cfg(peri_sai1)]
+    Sai1 = 0,
+    #[cfg(peri_sai2)]
+    Sai2 = 1,
+    #[cfg(peri_sai3)]
+    Sai3 = 2,
+    #[cfg(peri_sai4)]
+    Sai4 = 3,
+}
+
 #[derive(Copy, Clone, PartialEq)]
 pub enum StereoMono {
     Stereo,
@@ -428,8 +441,8 @@ impl MasterClockDivider {
 pub struct Config {
     pub mode: Mode,
     pub tx_rx: TxRx,
-    pub sync_enable: SyncEnable,
-    pub is_sync_output: bool,
+    pub sync_input: SyncInput,
+    pub sync_output: bool,
     pub protocol: Protocol,
     pub slot_size: SlotSize,
     pub slot_count: word::U4,
@@ -459,8 +472,8 @@ impl Default for Config {
         Self {
             mode: Mode::Master,
             tx_rx: TxRx::Transmitter,
-            is_sync_output: false,
-            sync_enable: SyncEnable::Asynchronous,
+            sync_output: false,
+            sync_input: SyncInput::None,
             protocol: Protocol::Free,
             slot_size: SlotSize::DataSize,
             slot_count: word::U4(2),
@@ -608,18 +621,18 @@ impl<'d, T: Instance> Sai<'d, T> {
 
 fn update_synchronous_config(config: &mut Config) {
     config.mode = Mode::Slave;
-    config.is_sync_output = false;
+    config.sync_output = false;
 
     #[cfg(any(sai_v1, sai_v2, sai_v3))]
     {
-        config.sync_enable = SyncEnable::Internal;
+        config.sync_input = SyncInput::Internal;
     }
 
     #[cfg(any(sai_v4))]
     {
         //this must either be Internal or External
-        //The asynchronous sub-block on the same SAI needs to enable is_sync_output
-        assert!(config.sync_enable != SyncEnable::Asynchronous);
+        //The asynchronous sub-block on the same SAI needs to enable sync_output
+        assert!(config.sync_input != SyncInput::None);
     }
 }
 
@@ -866,20 +879,13 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
 
         #[cfg(any(sai_v4))]
         {
-            // Not totally clear from the datasheet if this is right
-            // This is only used if using SyncEnable::External on the other SAI unit
-            // Syncing from SAIX subblock A to subblock B does not require this
-            // Only syncing from SAI1 subblock A/B to SAI2 subblock A/B
-            let value: u8 = if T::REGS.as_ptr() == stm32_metapac::SAI1.as_ptr() {
-                1 //this is SAI1, so sync with SAI2
-            } else {
-                0 //this is SAI2, so sync with SAI1
-            };
-            T::REGS.gcr().modify(|w| {
-                w.set_syncin(value);
-            });
+            if let SyncInput::External(i) = config.sync_input {
+                T::REGS.gcr().modify(|w| {
+                    w.set_syncin(i as u8);
+                });
+            }
 
-            if config.is_sync_output {
+            if config.sync_output {
                 let syncout: u8 = match sub_block {
                     WhichSubBlock::A => 0b01,
                     WhichSubBlock::B => 0b10,
@@ -903,7 +909,7 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
                 w.set_ds(config.data_size.ds());
                 w.set_lsbfirst(config.bit_order.lsbfirst());
                 w.set_ckstr(config.clock_strobe.ckstr());
-                w.set_syncen(config.sync_enable.syncen());
+                w.set_syncen(config.sync_input.syncen());
                 w.set_mono(config.stereo_mono.mono());
                 w.set_outdriv(config.output_drive.outdriv());
                 w.set_mckdiv(config.master_clock_divider.mckdiv());

embassy-sync/README.md

@@ -5,6 +5,7 @@ An [Embassy](https://embassy.dev) project.
 Synchronization primitives and data structures with async support:
 
 - [`Channel`](channel::Channel) - A Multiple Producer Multiple Consumer (MPMC) channel. Each message is only received by a single consumer.
+- [`PriorityChannel`](channel::priority::PriorityChannel) - A Multiple Producer Multiple Consumer (MPMC) channel. Each message is only received by a single consumer. Higher priority items are sifted to the front of the channel.
 - [`PubSubChannel`](pubsub::PubSubChannel) - A broadcast channel (publish-subscribe) channel. Each message is received by all consumers.
 - [`Signal`](signal::Signal) - Signalling latest value to a single consumer.
 - [`Mutex`](mutex::Mutex) - Mutex for synchronizing state between asynchronous tasks.

embassy-sync/src/channel.rs

@@ -76,7 +76,7 @@ where
 
 /// Send-only access to a [`Channel`] without knowing channel size.
 pub struct DynamicSender<'ch, T> {
-    channel: &'ch dyn DynamicChannel<T>,
+    pub(crate) channel: &'ch dyn DynamicChannel<T>,
 }
 
 impl<'ch, T> Clone for DynamicSender<'ch, T> {
@@ -176,7 +176,7 @@ where
 
 /// Receive-only access to a [`Channel`] without knowing channel size.
 pub struct DynamicReceiver<'ch, T> {
-    channel: &'ch dyn DynamicChannel<T>,
+    pub(crate) channel: &'ch dyn DynamicChannel<T>,
 }
 
 impl<'ch, T> Clone for DynamicReceiver<'ch, T> {
@@ -321,7 +321,7 @@ impl<'ch, T> Future for DynamicSendFuture<'ch, T> {
 
 impl<'ch, T> Unpin for DynamicSendFuture<'ch, T> {}
 
-trait DynamicChannel<T> {
+pub(crate) trait DynamicChannel<T> {
     fn try_send_with_context(&self, message: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>>;
 
     fn try_receive_with_context(&self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError>;

embassy-sync/src/lib.rs

@@ -15,6 +15,7 @@ pub mod blocking_mutex;
 pub mod channel;
 pub mod mutex;
 pub mod pipe;
+pub mod priority_channel;
 pub mod pubsub;
 pub mod signal;
 pub mod waitqueue;

embassy-sync/src/priority_channel.rs

@@ -0,0 +1,613 @@
+//! A queue for sending values between asynchronous tasks.
+//!
+//! Similar to a [`Channel`](crate::channel::Channel), however [`PriorityChannel`] sifts higher priority items to the front of the queue.
+//! Priority is determined by the `Ord` trait. Priority behavior is determined by the [`Kind`](heapless::binary_heap::Kind) parameter of the channel.
+
+use core::cell::RefCell;
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+pub use heapless::binary_heap::{Kind, Max, Min};
+use heapless::BinaryHeap;
+
+use crate::blocking_mutex::raw::RawMutex;
+use crate::blocking_mutex::Mutex;
+use crate::channel::{DynamicChannel, DynamicReceiver, DynamicSender, TryReceiveError, TrySendError};
+use crate::waitqueue::WakerRegistration;
+
+/// Send-only access to a [`PriorityChannel`].
+pub struct Sender<'ch, M, T, K, const N: usize>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    channel: &'ch PriorityChannel<M, T, K, N>,
+}
+
+impl<'ch, M, T, K, const N: usize> Clone for Sender<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    fn clone(&self) -> Self {
+        Sender { channel: self.channel }
+    }
+}
+
+impl<'ch, M, T, K, const N: usize> Copy for Sender<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+}
+
+impl<'ch, M, T, K, const N: usize> Sender<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    /// Sends a value.
+    ///
+    /// See [`PriorityChannel::send()`]
+    pub fn send(&self, message: T) -> SendFuture<'ch, M, T, K, N> {
+        self.channel.send(message)
+    }
+
+    /// Attempt to immediately send a message.
+    ///
+    /// See [`PriorityChannel::send()`]
+    pub fn try_send(&self, message: T) -> Result<(), TrySendError<T>> {
+        self.channel.try_send(message)
+    }
+
+    /// Allows a poll_fn to poll until the channel is ready to send
+    ///
+    /// See [`PriorityChannel::poll_ready_to_send()`]
+    pub fn poll_ready_to_send(&self, cx: &mut Context<'_>) -> Poll<()> {
+        self.channel.poll_ready_to_send(cx)
+    }
+}
+
+impl<'ch, M, T, K, const N: usize> From<Sender<'ch, M, T, K, N>> for DynamicSender<'ch, T>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    fn from(s: Sender<'ch, M, T, K, N>) -> Self {
+        Self { channel: s.channel }
+    }
+}
+
+/// Receive-only access to a [`PriorityChannel`].
+pub struct Receiver<'ch, M, T, K, const N: usize>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    channel: &'ch PriorityChannel<M, T, K, N>,
+}
+
+impl<'ch, M, T, K, const N: usize> Clone for Receiver<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    fn clone(&self) -> Self {
+        Receiver { channel: self.channel }
+    }
+}
+
+impl<'ch, M, T, K, const N: usize> Copy for Receiver<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+}
+
+impl<'ch, M, T, K, const N: usize> Receiver<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    /// Receive the next value.
+    ///
+    /// See [`PriorityChannel::receive()`].
+    pub fn receive(&self) -> ReceiveFuture<'_, M, T, K, N> {
+        self.channel.receive()
+    }
+
+    /// Attempt to immediately receive the next value.
+    ///
+    /// See [`PriorityChannel::try_receive()`]
+    pub fn try_receive(&self) -> Result<T, TryReceiveError> {
+        self.channel.try_receive()
+    }
+
+    /// Allows a poll_fn to poll until the channel is ready to receive
+    ///
+    /// See [`PriorityChannel::poll_ready_to_receive()`]
+    pub fn poll_ready_to_receive(&self, cx: &mut Context<'_>) -> Poll<()> {
+        self.channel.poll_ready_to_receive(cx)
+    }
+
+    /// Poll the channel for the next item
+    ///
+    /// See [`PriorityChannel::poll_receive()`]
+    pub fn poll_receive(&self, cx: &mut Context<'_>) -> Poll<T> {
+        self.channel.poll_receive(cx)
+    }
+}
+
+impl<'ch, M, T, K, const N: usize> From<Receiver<'ch, M, T, K, N>> for DynamicReceiver<'ch, T>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    fn from(s: Receiver<'ch, M, T, K, N>) -> Self {
+        Self { channel: s.channel }
+    }
+}
+
+/// Future returned by [`PriorityChannel::receive`] and  [`Receiver::receive`].
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct ReceiveFuture<'ch, M, T, K, const N: usize>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    channel: &'ch PriorityChannel<M, T, K, N>,
+}
+
+impl<'ch, M, T, K, const N: usize> Future for ReceiveFuture<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    type Output = T;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
+        self.channel.poll_receive(cx)
+    }
+}
+
+/// Future returned by [`PriorityChannel::send`] and  [`Sender::send`].
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct SendFuture<'ch, M, T, K, const N: usize>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    channel: &'ch PriorityChannel<M, T, K, N>,
+    message: Option<T>,
+}
+
+impl<'ch, M, T, K, const N: usize> Future for SendFuture<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    type Output = ();
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        match self.message.take() {
+            Some(m) => match self.channel.try_send_with_context(m, Some(cx)) {
+                Ok(..) => Poll::Ready(()),
+                Err(TrySendError::Full(m)) => {
+                    self.message = Some(m);
+                    Poll::Pending
+                }
+            },
+            None => panic!("Message cannot be None"),
+        }
+    }
+}
+
+impl<'ch, M, T, K, const N: usize> Unpin for SendFuture<'ch, M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+}
+
+struct ChannelState<T, K, const N: usize> {
+    queue: BinaryHeap<T, K, N>,
+    receiver_waker: WakerRegistration,
+    senders_waker: WakerRegistration,
+}
+
+impl<T, K, const N: usize> ChannelState<T, K, N>
+where
+    T: Ord,
+    K: Kind,
+{
+    const fn new() -> Self {
+        ChannelState {
+            queue: BinaryHeap::new(),
+            receiver_waker: WakerRegistration::new(),
+            senders_waker: WakerRegistration::new(),
+        }
+    }
+
+    fn try_receive(&mut self) -> Result<T, TryReceiveError> {
+        self.try_receive_with_context(None)
+    }
+
+    fn try_receive_with_context(&mut self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError> {
+        if self.queue.len() == self.queue.capacity() {
+            self.senders_waker.wake();
+        }
+
+        if let Some(message) = self.queue.pop() {
+            Ok(message)
+        } else {
+            if let Some(cx) = cx {
+                self.receiver_waker.register(cx.waker());
+            }
+            Err(TryReceiveError::Empty)
+        }
+    }
+
+    fn poll_receive(&mut self, cx: &mut Context<'_>) -> Poll<T> {
+        if self.queue.len() == self.queue.capacity() {
+            self.senders_waker.wake();
+        }
+
+        if let Some(message) = self.queue.pop() {
+            Poll::Ready(message)
+        } else {
+            self.receiver_waker.register(cx.waker());
+            Poll::Pending
+        }
+    }
+
+    fn poll_ready_to_receive(&mut self, cx: &mut Context<'_>) -> Poll<()> {
+        self.receiver_waker.register(cx.waker());
+
+        if !self.queue.is_empty() {
+            Poll::Ready(())
+        } else {
+            Poll::Pending
+        }
+    }
+
+    fn try_send(&mut self, message: T) -> Result<(), TrySendError<T>> {
+        self.try_send_with_context(message, None)
+    }
+
+    fn try_send_with_context(&mut self, message: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>> {
+        match self.queue.push(message) {
+            Ok(()) => {
+                self.receiver_waker.wake();
+                Ok(())
+            }
+            Err(message) => {
+                if let Some(cx) = cx {
+                    self.senders_waker.register(cx.waker());
+                }
+                Err(TrySendError::Full(message))
+            }
+        }
+    }
+
+    fn poll_ready_to_send(&mut self, cx: &mut Context<'_>) -> Poll<()> {
+        self.senders_waker.register(cx.waker());
+
+        if !self.queue.len() == self.queue.capacity() {
+            Poll::Ready(())
+        } else {
+            Poll::Pending
+        }
+    }
+}
+
+/// A bounded channel for communicating between asynchronous tasks
+/// with backpressure.
+///
+/// The channel will buffer up to the provided number of messages.  Once the
+/// buffer is full, attempts to `send` new messages will wait until a message is
+/// received from the channel.
+///
+/// Sent data may be reordered based on their priorty within the channel.
+/// For example, in a [`Max`](heapless::binary_heap::Max) [`PriorityChannel`]
+/// containing `u32`'s, data sent in the following order `[1, 2, 3]` will be recieved as `[3, 2, 1]`.
+pub struct PriorityChannel<M, T, K, const N: usize>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    inner: Mutex<M, RefCell<ChannelState<T, K, N>>>,
+}
+
+impl<M, T, K, const N: usize> PriorityChannel<M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    /// Establish a new bounded channel. For example, to create one with a NoopMutex:
+    ///
+    /// ```
+    /// use embassy_sync::priority_channel::{PriorityChannel, Max};
+    /// use embassy_sync::blocking_mutex::raw::NoopRawMutex;
+    ///
+    /// // Declare a bounded channel of 3 u32s.
+    /// let mut channel = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
+    /// ```
+    pub const fn new() -> Self {
+        Self {
+            inner: Mutex::new(RefCell::new(ChannelState::new())),
+        }
+    }
+
+    fn lock<R>(&self, f: impl FnOnce(&mut ChannelState<T, K, N>) -> R) -> R {
+        self.inner.lock(|rc| f(&mut *unwrap!(rc.try_borrow_mut())))
+    }
+
+    fn try_receive_with_context(&self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError> {
+        self.lock(|c| c.try_receive_with_context(cx))
+    }
+
+    /// Poll the channel for the next message
+    pub fn poll_receive(&self, cx: &mut Context<'_>) -> Poll<T> {
+        self.lock(|c| c.poll_receive(cx))
+    }
+
+    fn try_send_with_context(&self, m: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>> {
+        self.lock(|c| c.try_send_with_context(m, cx))
+    }
+
+    /// Allows a poll_fn to poll until the channel is ready to receive
+    pub fn poll_ready_to_receive(&self, cx: &mut Context<'_>) -> Poll<()> {
+        self.lock(|c| c.poll_ready_to_receive(cx))
+    }
+
+    /// Allows a poll_fn to poll until the channel is ready to send
+    pub fn poll_ready_to_send(&self, cx: &mut Context<'_>) -> Poll<()> {
+        self.lock(|c| c.poll_ready_to_send(cx))
+    }
+
+    /// Get a sender for this channel.
+    pub fn sender(&self) -> Sender<'_, M, T, K, N> {
+        Sender { channel: self }
+    }
+
+    /// Get a receiver for this channel.
+    pub fn receiver(&self) -> Receiver<'_, M, T, K, N> {
+        Receiver { channel: self }
+    }
+
+    /// Send a value, waiting until there is capacity.
+    ///
+    /// Sending completes when the value has been pushed to the channel's queue.
+    /// This doesn't mean the value has been received yet.
+    pub fn send(&self, message: T) -> SendFuture<'_, M, T, K, N> {
+        SendFuture {
+            channel: self,
+            message: Some(message),
+        }
+    }
+
+    /// Attempt to immediately send a message.
+    ///
+    /// This method differs from [`send`](PriorityChannel::send) by returning immediately if the channel's
+    /// buffer is full, instead of waiting.
+    ///
+    /// # Errors
+    ///
+    /// If the channel capacity has been reached, i.e., the channel has `n`
+    /// buffered values where `n` is the argument passed to [`PriorityChannel`], then an
+    /// error is returned.
+    pub fn try_send(&self, message: T) -> Result<(), TrySendError<T>> {
+        self.lock(|c| c.try_send(message))
+    }
+
+    /// Receive the next value.
+    ///
+    /// If there are no messages in the channel's buffer, this method will
+    /// wait until a message is sent.
+    pub fn receive(&self) -> ReceiveFuture<'_, M, T, K, N> {
+        ReceiveFuture { channel: self }
+    }
+
+    /// Attempt to immediately receive a message.
+    ///
+    /// This method will either receive a message from the channel immediately or return an error
+    /// if the channel is empty.
+    pub fn try_receive(&self) -> Result<T, TryReceiveError> {
+        self.lock(|c| c.try_receive())
+    }
+}
+
+/// Implements the DynamicChannel to allow creating types that are unaware of the queue size with the
+/// tradeoff cost of dynamic dispatch.
+impl<M, T, K, const N: usize> DynamicChannel<T> for PriorityChannel<M, T, K, N>
+where
+    T: Ord,
+    K: Kind,
+    M: RawMutex,
+{
+    fn try_send_with_context(&self, m: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>> {
+        PriorityChannel::try_send_with_context(self, m, cx)
+    }
+
+    fn try_receive_with_context(&self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError> {
+        PriorityChannel::try_receive_with_context(self, cx)
+    }
+
+    fn poll_ready_to_send(&self, cx: &mut Context<'_>) -> Poll<()> {
+        PriorityChannel::poll_ready_to_send(self, cx)
+    }
+
+    fn poll_ready_to_receive(&self, cx: &mut Context<'_>) -> Poll<()> {
+        PriorityChannel::poll_ready_to_receive(self, cx)
+    }
+
+    fn poll_receive(&self, cx: &mut Context<'_>) -> Poll<T> {
+        PriorityChannel::poll_receive(self, cx)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use core::time::Duration;
+
+    use futures_executor::ThreadPool;
+    use futures_timer::Delay;
+    use futures_util::task::SpawnExt;
+    use heapless::binary_heap::{Kind, Max};
+    use static_cell::StaticCell;
+
+    use super::*;
+    use crate::blocking_mutex::raw::{CriticalSectionRawMutex, NoopRawMutex};
+
+    fn capacity<T, K, const N: usize>(c: &ChannelState<T, K, N>) -> usize
+    where
+        T: Ord,
+        K: Kind,
+    {
+        c.queue.capacity() - c.queue.len()
+    }
+
+    #[test]
+    fn sending_once() {
+        let mut c = ChannelState::<u32, Max, 3>::new();
+        assert!(c.try_send(1).is_ok());
+        assert_eq!(capacity(&c), 2);
+    }
+
+    #[test]
+    fn sending_when_full() {
+        let mut c = ChannelState::<u32, Max, 3>::new();
+        let _ = c.try_send(1);
+        let _ = c.try_send(1);
+        let _ = c.try_send(1);
+        match c.try_send(2) {
+            Err(TrySendError::Full(2)) => assert!(true),
+            _ => assert!(false),
+        }
+        assert_eq!(capacity(&c), 0);
+    }
+
+    #[test]
+    fn send_priority() {
+        // Prio channel with kind `Max` sifts larger numbers to the front of the queue
+        let mut c = ChannelState::<u32, Max, 3>::new();
+        assert!(c.try_send(1).is_ok());
+        assert!(c.try_send(2).is_ok());
+        assert!(c.try_send(3).is_ok());
+        assert_eq!(c.try_receive().unwrap(), 3);
+        assert_eq!(c.try_receive().unwrap(), 2);
+        assert_eq!(c.try_receive().unwrap(), 1);
+    }
+
+    #[test]
+    fn receiving_once_with_one_send() {
+        let mut c = ChannelState::<u32, Max, 3>::new();
+        assert!(c.try_send(1).is_ok());
+        assert_eq!(c.try_receive().unwrap(), 1);
+        assert_eq!(capacity(&c), 3);
+    }
+
+    #[test]
+    fn receiving_when_empty() {
+        let mut c = ChannelState::<u32, Max, 3>::new();
+        match c.try_receive() {
+            Err(TryReceiveError::Empty) => assert!(true),
+            _ => assert!(false),
+        }
+        assert_eq!(capacity(&c), 3);
+    }
+
+    #[test]
+    fn simple_send_and_receive() {
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
+        assert!(c.try_send(1).is_ok());
+        assert_eq!(c.try_receive().unwrap(), 1);
+    }
+
+    #[test]
+    fn cloning() {
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
+        let r1 = c.receiver();
+        let s1 = c.sender();
+
+        let _ = r1.clone();
+        let _ = s1.clone();
+    }
+
+    #[test]
+    fn dynamic_dispatch() {
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
+        let s: DynamicSender<'_, u32> = c.sender().into();
+        let r: DynamicReceiver<'_, u32> = c.receiver().into();
+
+        assert!(s.try_send(1).is_ok());
+        assert_eq!(r.try_receive().unwrap(), 1);
+    }
+
+    #[futures_test::test]
+    async fn receiver_receives_given_try_send_async() {
+        let executor = ThreadPool::new().unwrap();
+
+        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, Max, 3>> = StaticCell::new();
+        let c = &*CHANNEL.init(PriorityChannel::new());
+        let c2 = c;
+        assert!(executor
+            .spawn(async move {
+                assert!(c2.try_send(1).is_ok());
+            })
+            .is_ok());
+        assert_eq!(c.receive().await, 1);
+    }
+
+    #[futures_test::test]
+    async fn sender_send_completes_if_capacity() {
+        let c = PriorityChannel::<CriticalSectionRawMutex, u32, Max, 1>::new();
+        c.send(1).await;
+        assert_eq!(c.receive().await, 1);
+    }
+
+    #[futures_test::test]
+    async fn senders_sends_wait_until_capacity() {
+        let executor = ThreadPool::new().unwrap();
+
+        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, Max, 1>> = StaticCell::new();
+        let c = &*CHANNEL.init(PriorityChannel::new());
+        assert!(c.try_send(1).is_ok());
+
+        let c2 = c;
+        let send_task_1 = executor.spawn_with_handle(async move { c2.send(2).await });
+        let c2 = c;
+        let send_task_2 = executor.spawn_with_handle(async move { c2.send(3).await });
+        // Wish I could think of a means of determining that the async send is waiting instead.
+        // However, I've used the debugger to observe that the send does indeed wait.
+        Delay::new(Duration::from_millis(500)).await;
+        assert_eq!(c.receive().await, 1);
+        assert!(executor
+            .spawn(async move {
+                loop {
+                    c.receive().await;
+                }
+            })
+            .is_ok());
+        send_task_1.unwrap().await;
+        send_task_2.unwrap().await;
+    }
+}

embassy-time/Cargo.toml

@@ -258,4 +258,4 @@ wasm-timer = { version = "0.2.5", optional = true }
 [dev-dependencies]
 serial_test = "0.9"
 critical-section = { version = "1.1", features = ["std"] }
-embassy-executor = { version = "0.3.1", path = "../embassy-executor", features = ["nightly"] }
+embassy-executor = { version = "0.3.3", path = "../embassy-executor", features = ["nightly"] }

examples/boot/application/nrf/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers", "arch-cortex-m", "executor-thread"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers", "arch-cortex-m", "executor-thread"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly"] }
 embassy-nrf = { version = "0.1.0", path = "../../../../embassy-nrf", features = ["time-driver-rtc1", "gpiote", "nightly"] }
 embassy-boot = { version = "0.1.0", path = "../../../../embassy-boot/boot", features = ["nightly"] }

examples/boot/application/rp/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers", "arch-cortex-m", "executor-thread"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers", "arch-cortex-m", "executor-thread"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly"] }
 embassy-rp = { version = "0.1.0", path = "../../../../embassy-rp", features = ["time-driver", "unstable-traits", "nightly"] }
 embassy-boot-rp = { version = "0.1.0", path = "../../../../embassy-boot/rp", features = ["nightly"] }

examples/boot/application/rp/memory.x

@@ -5,7 +5,19 @@ MEMORY
   BOOTLOADER_STATE                  : ORIGIN = 0x10006000, LENGTH = 4K
   FLASH                             : ORIGIN = 0x10007000, LENGTH = 512K
   DFU                               : ORIGIN = 0x10087000, LENGTH = 516K
-  RAM                               : ORIGIN = 0x20000000, LENGTH = 256K
+
+  /* Pick one of the two options for RAM layout     */
+
+  /* OPTION A: Use all RAM banks as one big block   */
+  /* Reasonable, unless you are doing something     */
+  /* really particular with DMA or other concurrent */
+  /* access that would benefit from striping        */
+  RAM   : ORIGIN = 0x20000000, LENGTH = 264K
+
+  /* OPTION B: Keep the unstriped sections separate */
+  /* RAM: ORIGIN = 0x20000000, LENGTH = 256K        */
+  /* SCRATCH_A: ORIGIN = 0x20040000, LENGTH = 4K    */
+  /* SCRATCH_B: ORIGIN = 0x20041000, LENGTH = 4K    */
 }
 
 __bootloader_state_start = ORIGIN(BOOTLOADER_STATE) - ORIGIN(BOOT2);

examples/boot/application/stm32f3/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32f303re", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32f7/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32f767zi", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32h7/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32h743zi", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32l0/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32l072cz", "time-driver-any", "exti", "memory-x"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32l1/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32l151cb-a", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32l4/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32l475vg", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/application/stm32wl/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../../../embassy-time", features = ["nightly", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["unstable-traits", "nightly", "stm32wl55jc-cm4", "time-driver-any", "exti"]  }
 embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = ["nightly"] }

examples/boot/bootloader/rp/memory.x

@@ -6,7 +6,19 @@ MEMORY
   BOOTLOADER_STATE                  : ORIGIN = 0x10006000, LENGTH = 4K
   ACTIVE                            : ORIGIN = 0x10007000, LENGTH = 512K
   DFU                               : ORIGIN = 0x10087000, LENGTH = 516K
-  RAM                               : ORIGIN = 0x20000000, LENGTH = 256K
+
+  /* Pick one of the two options for RAM layout     */
+
+  /* OPTION A: Use all RAM banks as one big block   */
+  /* Reasonable, unless you are doing something     */
+  /* really particular with DMA or other concurrent */
+  /* access that would benefit from striping        */
+  RAM   : ORIGIN = 0x20000000, LENGTH = 264K
+
+  /* OPTION B: Keep the unstriped sections separate */
+  /* RAM: ORIGIN = 0x20000000, LENGTH = 256K        */
+  /* SCRATCH_A: ORIGIN = 0x20040000, LENGTH = 4K    */
+  /* SCRATCH_B: ORIGIN = 0x20041000, LENGTH = 4K    */
 }
 
 __bootloader_state_start = ORIGIN(BOOTLOADER_STATE) - ORIGIN(BOOT2);

examples/nrf-rtos-trace/Cargo.toml

@@ -17,7 +17,7 @@ log = [
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync" }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "rtos-trace", "rtos-trace-interrupt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "rtos-trace", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time" }
 embassy-nrf = { version = "0.1.0", path = "../../embassy-nrf", features = ["nrf52840", "time-driver-rtc1", "gpiote", "unstable-pac"] }
 

examples/nrf52840/Cargo.toml

@@ -30,7 +30,7 @@ nightly = [
 [dependencies]
 embassy-futures = { version = "0.1.0", path = "../../embassy-futures" }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime"] }
 embassy-nrf = { version = "0.1.0", path = "../../embassy-nrf", features = ["defmt", "nrf52840", "time-driver-rtc1", "gpiote", "unstable-pac", "time"] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features = ["defmt", "tcp", "dhcpv4", "medium-ethernet"], optional = true }

examples/nrf5340/Cargo.toml

@@ -9,7 +9,7 @@ embassy-futures = { version = "0.1.0", path = "../../embassy-futures" }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = [
     "defmt",
 ] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", 
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", 
     "nightly",
     "defmt",
     "integrated-timers",

examples/rp/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 [dependencies]
 embassy-embedded-hal = { version = "0.1.0", path = "../../embassy-embedded-hal", features = ["defmt"] }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["nightly", "unstable-traits", "defmt", "defmt-timestamp-uptime"] }
 embassy-rp = { version = "0.1.0", path = "../../embassy-rp", features = ["defmt", "unstable-traits", "nightly", "unstable-pac", "time-driver", "critical-section-impl"] }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }

examples/rp/memory.x

@@ -1,5 +1,17 @@
 MEMORY {
     BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
     FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
-    RAM   : ORIGIN = 0x20000000, LENGTH = 256K
-}
+
+    /* Pick one of the two options for RAM layout     */
+
+    /* OPTION A: Use all RAM banks as one big block   */
+    /* Reasonable, unless you are doing something     */
+    /* really particular with DMA or other concurrent */
+    /* access that would benefit from striping        */
+    RAM   : ORIGIN = 0x20000000, LENGTH = 264K
+
+    /* OPTION B: Keep the unstriped sections separate */
+    /* RAM: ORIGIN = 0x20000000, LENGTH = 256K        */
+    /* SCRATCH_A: ORIGIN = 0x20040000, LENGTH = 4K    */
+    /* SCRATCH_B: ORIGIN = 0x20041000, LENGTH = 4K    */
+}

examples/std/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["log"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["arch-std", "executor-thread", "log", "nightly", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["arch-std", "executor-thread", "log", "nightly", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["log", "std", "nightly"] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features=[ "std", "nightly", "log", "medium-ethernet", "medium-ip", "tcp", "udp", "dns", "dhcpv4", "proto-ipv6"] }
 embassy-net-tuntap = { version = "0.1.0", path = "../../embassy-net-tuntap" }

examples/stm32c0/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32c031c6 to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "time-driver-any", "stm32c031c6", "memory-x", "unstable-pac", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 
 defmt = "0.3"

examples/stm32f0/Cargo.toml

@@ -15,7 +15,7 @@ defmt = "0.3"
 defmt-rtt = "0.4"
 panic-probe = "0.3"
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 static_cell = { version = "2", features = ["nightly"]}
 portable-atomic = { version = "1.5", features = ["unsafe-assume-single-core"] }

examples/stm32f1/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32f103c8 to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f103c8", "unstable-pac", "memory-x", "time-driver-any", "unstable-traits" ]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
 embassy-futures = { version = "0.1.0", path = "../../embassy-futures" }

examples/stm32f2/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32f207zg to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f207zg", "unstable-pac", "memory-x", "time-driver-any", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 
 defmt = "0.3"

examples/stm32f3/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32f303ze to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f303ze", "unstable-pac", "memory-x", "time-driver-any", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
 embassy-futures = { version = "0.1.0", path = "../../embassy-futures" }

examples/stm32f334/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.0", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f334r8", "unstable-pac", "memory-x", "time-driver-any", "exti"]  }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }

examples/stm32f334/src/bin/opamp.rs

@@ -39,7 +39,7 @@ async fn main(_spawner: Spawner) -> ! {
 
     let mut vrefint = adc.enable_vref(&mut Delay);
     let mut temperature = adc.enable_temperature();
-    let mut buffer = opamp.buffer_ext(&p.PA7, &mut p.PA6, OpAmpGain::Mul1);
+    let mut buffer = opamp.buffer_ext(&mut p.PA7, &mut p.PA6, OpAmpGain::Mul1);
 
     loop {
         let vref = adc.read(&mut vrefint).await;

examples/stm32f4/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32f429zi to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "unstable-traits", "defmt", "stm32f429zi", "unstable-pac", "memory-x", "time-driver-any", "exti", "embedded-sdmmc", "chrono"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "unstable-traits", "tick-hz-32_768"] }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt" ] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features = ["defmt", "tcp", "dhcpv4", "medium-ethernet", "nightly"] }

examples/stm32f4/src/bin/dac.rs

@@ -4,7 +4,7 @@
 
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dac::{DacCh1, Value};
 use embassy_stm32::dma::NoDma;
 use {defmt_rtt as _, panic_probe as _};
 
@@ -14,11 +14,10 @@ async fn main(_spawner: Spawner) -> ! {
     info!("Hello World, dude!");
 
     let mut dac = DacCh1::new(p.DAC, NoDma, p.PA4);
-    unwrap!(dac.set_trigger_enable(false));
 
     loop {
         for v in 0..=255 {
-            unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
+            dac.set(Value::Bit8(to_sine_wave(v)));
         }
     }
 }

examples/stm32f4/src/bin/i2c.rs

@@ -14,7 +14,8 @@ const ADDRESS: u8 = 0x5F;
 const WHOAMI: u8 = 0x0F;
 
 bind_interrupts!(struct Irqs {
-    I2C2_EV => i2c::InterruptHandler<peripherals::I2C2>;
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
 });
 
 #[embassy_executor::main]

examples/stm32f4/src/bin/i2c_async.rs

@@ -0,0 +1,62 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+// Example originally designed for stm32f411ceu6 reading an A1454 hall effect sensor on I2C1
+// DMA peripherals changed to compile for stm32f429zi, for the CI.
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::i2c::I2c;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::{bind_interrupts, i2c, peripherals};
+use {defmt_rtt as _, panic_probe as _};
+
+const ADDRESS: u8 = 96;
+
+bind_interrupts!(struct Irqs {
+    I2C1_EV => i2c::EventInterruptHandler<peripherals::I2C1>;
+    I2C1_ER => i2c::ErrorInterruptHandler<peripherals::I2C1>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    info!("Hello world!");
+    let p = embassy_stm32::init(Default::default());
+
+    let mut i2c = I2c::new(
+        p.I2C1,
+        p.PB8,
+        p.PB7,
+        Irqs,
+        p.DMA1_CH6,
+        p.DMA1_CH0,
+        Hertz(100_000),
+        Default::default(),
+    );
+
+    loop {
+        let a1454_read_sensor_command = [0x1F];
+        let mut sensor_data_buffer: [u8; 4] = [0, 0, 0, 0];
+
+        match i2c
+            .write_read(ADDRESS, &a1454_read_sensor_command, &mut sensor_data_buffer)
+            .await
+        {
+            Ok(()) => {
+                // Convert 12-bit signed integer into 16-bit signed integer.
+                // Is the 12 bit number negative?
+                if (sensor_data_buffer[2] & 0b00001000) == 0b0001000 {
+                    sensor_data_buffer[2] = sensor_data_buffer[2] | 0b11110000;
+                }
+
+                let mut sensor_value_raw: u16 = sensor_data_buffer[3].into();
+                sensor_value_raw |= (sensor_data_buffer[2] as u16) << 8;
+                let sensor_value: u16 = sensor_value_raw.into();
+                let sensor_value = sensor_value as i16;
+                info!("Data: {}", sensor_value);
+            }
+            Err(e) => error!("I2C Error during read: {:?}", e),
+        }
+    }
+}

examples/stm32f4/src/bin/i2c_comparison.rs

@@ -0,0 +1,135 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+// Example originally designed for stm32f411ceu6 with three A1454 hall effect sensors, connected to I2C1, 2 and 3
+// on the pins referenced in the peripheral definitions.
+// Pins and DMA peripherals changed to compile for stm32f429zi, to work with the CI.
+// MUST be compiled in release mode to see actual performance, otherwise the async transactions take 2x
+// as long to complete as the blocking ones!
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::i2c::I2c;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::{bind_interrupts, i2c, peripherals};
+use embassy_time::Instant;
+use futures::future::try_join3;
+use {defmt_rtt as _, panic_probe as _};
+
+const ADDRESS: u8 = 96;
+
+bind_interrupts!(struct Irqs {
+    I2C1_EV => i2c::EventInterruptHandler<peripherals::I2C1>;
+    I2C1_ER => i2c::ErrorInterruptHandler<peripherals::I2C1>;
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
+    I2C3_EV => i2c::EventInterruptHandler<peripherals::I2C3>;
+    I2C3_ER => i2c::ErrorInterruptHandler<peripherals::I2C3>;
+});
+
+/// Convert 12-bit signed integer within a 4 byte long buffer into 16-bit signed integer.
+fn a1454_buf_to_i16(buffer: &[u8; 4]) -> i16 {
+    let lower = buffer[3];
+    let mut upper = buffer[2];
+    // Fill in additional 1s if the 12 bit number is negative.
+    if (upper & 0b00001000) == 0b0001000 {
+        upper = upper | 0b11110000;
+    }
+
+    let mut sensor_value_raw: u16 = lower.into();
+    sensor_value_raw |= (upper as u16) << 8;
+    let sensor_value: u16 = sensor_value_raw.into();
+    let sensor_value = sensor_value as i16;
+    sensor_value
+}
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    info!("Setting up peripherals.");
+    let p = embassy_stm32::init(Default::default());
+
+    let mut i2c1 = I2c::new(
+        p.I2C1,
+        p.PB8,
+        p.PB7,
+        Irqs,
+        p.DMA1_CH6,
+        p.DMA1_CH0,
+        Hertz(100_000),
+        Default::default(),
+    );
+
+    let mut i2c2 = I2c::new(
+        p.I2C2,
+        p.PB10,
+        p.PB11,
+        Irqs,
+        p.DMA1_CH7,
+        p.DMA1_CH3,
+        Hertz(100_000),
+        Default::default(),
+    );
+
+    let mut i2c3 = I2c::new(
+        p.I2C3,
+        p.PA8,
+        p.PC9,
+        Irqs,
+        p.DMA1_CH4,
+        p.DMA1_CH2,
+        Hertz(100_000),
+        Default::default(),
+    );
+
+    let a1454_read_sensor_command = [0x1F];
+    let mut i2c1_buffer: [u8; 4] = [0, 0, 0, 0];
+    let mut i2c2_buffer: [u8; 4] = [0, 0, 0, 0];
+    let mut i2c3_buffer: [u8; 4] = [0, 0, 0, 0];
+    loop {
+        // Blocking reads one after the other. Completes in about 2000us.
+        let blocking_read_start_us = Instant::now().as_micros();
+        match i2c1.blocking_write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c1_buffer) {
+            Ok(()) => {}
+            Err(e) => error!("I2C Error: {:?}", e),
+        }
+        match i2c2.blocking_write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c2_buffer) {
+            Ok(()) => {}
+            Err(e) => error!("I2C Error: {:?}", e),
+        }
+        match i2c3.blocking_write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c3_buffer) {
+            Ok(()) => {}
+            Err(e) => error!("I2C Error: {:?}", e),
+        }
+        let blocking_read_total_us = Instant::now().as_micros() - blocking_read_start_us;
+        info!(
+            "Blocking reads completed in {}us: i2c1: {} i2c2: {} i2c3: {}",
+            blocking_read_total_us,
+            a1454_buf_to_i16(&i2c1_buffer),
+            a1454_buf_to_i16(&i2c2_buffer),
+            a1454_buf_to_i16(&i2c3_buffer)
+        );
+
+        // Async reads overlapping. Completes in about 1000us.
+        let async_read_start_us = Instant::now().as_micros();
+
+        let i2c1_result = i2c1.write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c1_buffer);
+        let i2c2_result = i2c2.write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c2_buffer);
+        let i2c3_result = i2c3.write_read(ADDRESS, &a1454_read_sensor_command, &mut i2c3_buffer);
+
+        // Wait for all three transactions to finish, or any one of them to fail.
+        match try_join3(i2c1_result, i2c2_result, i2c3_result).await {
+            Ok(_) => {
+                let async_read_total_us = Instant::now().as_micros() - async_read_start_us;
+                info!(
+                    "Async reads completed in {}us: i2c1: {} i2c2: {} i2c3: {}",
+                    async_read_total_us,
+                    a1454_buf_to_i16(&i2c1_buffer),
+                    a1454_buf_to_i16(&i2c2_buffer),
+                    a1454_buf_to_i16(&i2c3_buffer)
+                );
+            }
+            Err(e) => error!("I2C Error during async write-read: {}", e),
+        };
+    }
+}

examples/stm32f7/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32f767zi to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f767zi", "memory-x", "unstable-pac", "time-driver-any", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features = ["defmt", "nightly", "tcp", "dhcpv4", "medium-ethernet"] }
 embedded-io-async = { version = "0.6.0" }

examples/stm32g0/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32g071rb to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "time-driver-any", "stm32g071rb", "memory-x", "unstable-pac", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 
 defmt = "0.3"

examples/stm32g4/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32g491re to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "time-driver-any", "stm32g491re", "memory-x", "unstable-pac", "exti"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
 embassy-futures = { version = "0.1.0", path = "../../embassy-futures" }

examples/stm32h5/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32h563zi to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32h563zi", "memory-x", "time-driver-any", "exti", "unstable-pac", "unstable-traits"] }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "unstable-traits", "tick-hz-32_768"] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features = ["defmt", "nightly", "tcp", "dhcpv4", "medium-ethernet", "proto-ipv6"] }
 embedded-io-async = { version = "0.6.0" }

examples/stm32h5/src/bin/i2c.rs

@@ -13,7 +13,8 @@ const ADDRESS: u8 = 0x5F;
 const WHOAMI: u8 = 0x0F;
 
 bind_interrupts!(struct Irqs {
-    I2C2_EV => i2c::InterruptHandler<peripherals::I2C2>;
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
 });
 
 #[embassy_executor::main]

examples/stm32h7/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32h743bi to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32h743bi", "time-driver-any", "exti", "memory-x", "unstable-pac", "unstable-traits", "chrono"] }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "unstable-traits", "tick-hz-32_768"] }
 embassy-net = { version = "0.2.0", path = "../../embassy-net", features = ["defmt", "nightly", "tcp", "dhcpv4", "medium-ethernet", "proto-ipv6", "dns"] }
 embedded-io-async = { version = "0.6.0" }

examples/stm32h7/src/bin/camera.rs

@@ -19,7 +19,8 @@ const HEIGHT: usize = 100;
 static mut FRAME: [u32; WIDTH * HEIGHT / 2] = [0u32; WIDTH * HEIGHT / 2];
 
 bind_interrupts!(struct Irqs {
-    I2C1_EV => i2c::InterruptHandler<peripherals::I2C1>;
+    I2C1_EV => i2c::EventInterruptHandler<peripherals::I2C1>;
+    I2C1_ER => i2c::ErrorInterruptHandler<peripherals::I2C1>;
     DCMI => dcmi::InterruptHandler<peripherals::DCMI>;
 });
 

examples/stm32h7/src/bin/dac.rs

@@ -4,7 +4,7 @@
 
 use cortex_m_rt::entry;
 use defmt::*;
-use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dac::{DacCh1, Value};
 use embassy_stm32::dma::NoDma;
 use embassy_stm32::Config;
 use {defmt_rtt as _, panic_probe as _};
@@ -46,11 +46,10 @@ fn main() -> ! {
     let p = embassy_stm32::init(config);
 
     let mut dac = DacCh1::new(p.DAC1, NoDma, p.PA4);
-    unwrap!(dac.set_trigger_enable(false));
 
     loop {
         for v in 0..=255 {
-            unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
+            dac.set(Value::Bit8(to_sine_wave(v)));
         }
     }
 }

examples/stm32h7/src/bin/dac_dma.rs

@@ -4,21 +4,15 @@
 
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::dac::{DacChannel, ValueArray};
+use embassy_stm32::dac::{DacCh1, DacCh2, ValueArray};
 use embassy_stm32::pac::timer::vals::{Mms, Opm};
-use embassy_stm32::peripherals::{TIM6, TIM7};
+use embassy_stm32::peripherals::{DAC1, DMA1_CH3, DMA1_CH4, TIM6, TIM7};
 use embassy_stm32::rcc::low_level::RccPeripheral;
 use embassy_stm32::time::Hertz;
 use embassy_stm32::timer::low_level::Basic16bitInstance;
 use micromath::F32Ext;
 use {defmt_rtt as _, panic_probe as _};
 
-pub type Dac1Type =
-    embassy_stm32::dac::DacCh1<'static, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH3>;
-
-pub type Dac2Type =
-    embassy_stm32::dac::DacCh2<'static, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH4>;
-
 #[embassy_executor::main]
 async fn main(spawner: Spawner) {
     let mut config = embassy_stm32::Config::default();
@@ -63,7 +57,7 @@ async fn main(spawner: Spawner) {
 }
 
 #[embassy_executor::task]
-async fn dac_task1(mut dac: Dac1Type) {
+async fn dac_task1(mut dac: DacCh1<'static, DAC1, DMA1_CH3>) {
     let data: &[u8; 256] = &calculate_array::<256>();
 
     info!("TIM6 frequency is {}", TIM6::frequency());
@@ -77,8 +71,9 @@ async fn dac_task1(mut dac: Dac1Type) {
         error!("Reload value {} below threshold!", reload);
     }
 
-    dac.select_trigger(embassy_stm32::dac::Ch1Trigger::Tim6).unwrap();
-    dac.enable_channel().unwrap();
+    dac.set_trigger(embassy_stm32::dac::TriggerSel::Tim6);
+    dac.set_triggering(true);
+    dac.enable();
 
     TIM6::enable_and_reset();
     TIM6::regs().arr().modify(|w| w.set_arr(reload as u16 - 1));
@@ -100,14 +95,12 @@ async fn dac_task1(mut dac: Dac1Type) {
     // Loop technically not necessary if DMA circular mode is enabled
     loop {
         info!("Loop DAC1");
-        if let Err(e) = dac.write(ValueArray::Bit8(data), true).await {
-            error!("Could not write to dac: {}", e);
-        }
+        dac.write(ValueArray::Bit8(data), true).await;
     }
 }
 
 #[embassy_executor::task]
-async fn dac_task2(mut dac: Dac2Type) {
+async fn dac_task2(mut dac: DacCh2<'static, DAC1, DMA1_CH4>) {
     let data: &[u8; 256] = &calculate_array::<256>();
 
     info!("TIM7 frequency is {}", TIM7::frequency());
@@ -127,7 +120,9 @@ async fn dac_task2(mut dac: Dac2Type) {
         w.set_cen(true);
     });
 
-    dac.select_trigger(embassy_stm32::dac::Ch2Trigger::Tim7).unwrap();
+    dac.set_trigger(embassy_stm32::dac::TriggerSel::Tim7);
+    dac.set_triggering(true);
+    dac.enable();
 
     debug!(
         "TIM7 Frequency {}, Target Frequency {}, Reload {}, Reload as u16 {}, Samples {}",
@@ -138,9 +133,7 @@ async fn dac_task2(mut dac: Dac2Type) {
         data.len()
     );
 
-    if let Err(e) = dac.write(ValueArray::Bit8(data), true).await {
-        error!("Could not write to dac: {}", e);
-    }
+    dac.write(ValueArray::Bit8(data), true).await;
 }
 
 fn to_sine_wave(v: u8) -> u8 {

examples/stm32h7/src/bin/i2c.rs

@@ -13,7 +13,8 @@ const ADDRESS: u8 = 0x5F;
 const WHOAMI: u8 = 0x0F;
 
 bind_interrupts!(struct Irqs {
-    I2C2_EV => i2c::InterruptHandler<peripherals::I2C2>;
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
 });
 
 #[embassy_executor::main]

examples/stm32l0/Cargo.toml

@@ -13,7 +13,7 @@ nightly = ["embassy-stm32/nightly", "embassy-time/nightly", "embassy-time/unstab
 # Change stm32l072cz to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "stm32l072cz", "time-driver-any", "exti", "unstable-traits", "memory-x"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-lora = { version = "0.1.0", path = "../../embassy-lora", features = ["time", "defmt"], optional = true }
 lora-phy = { version = "2", optional = true }

examples/stm32l1/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32l151cb-a", "time-driver-any", "memory-x"]  }
 

examples/stm32l4/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 # Change stm32l4s5vi to your chip name, if necessary.
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "unstable-pac", "stm32l4s5qi", "memory-x", "time-driver-any", "exti", "unstable-traits", "chrono"]  }
 embassy-sync = { version = "0.4.0", path = "../../embassy-sync", features = ["defmt"] }
-embassy-executor = { version = "0.3.1", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
+embassy-executor = { version = "0.3.3", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.5", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768", "unstable-traits", "nightly"] }
 embassy-embedded-hal = { version = "0.1.0", path = "../../embassy-embedded-hal" }
 embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }