diff --git a/embassy-rp/src/i2c.rs b/embassy-rp/src/i2c.rs index 7a5ddd32..c358682c 100644 --- a/embassy-rp/src/i2c.rs +++ b/embassy-rp/src/i2c.rs @@ -21,6 +21,8 @@ pub enum AbortReason { NoAcknowledge, /// The arbitration was lost, e.g. electrical problems with the clock signal ArbitrationLoss, + /// Transmit ended with data still in fifo + TxNotEmpty(u16), Other(u32), } @@ -52,7 +54,7 @@ impl Default for Config { } } -const FIFO_SIZE: u8 = 16; +pub const FIFO_SIZE: u8 = 16; pub struct I2c<'d, T: Instance, M: Mode> { phantom: PhantomData<(&'d mut T, M)>, @@ -636,6 +638,7 @@ mod eh1 { Self::Abort(AbortReason::NoAcknowledge) => { embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Address) } + Self::Abort(AbortReason::TxNotEmpty(_)) => embedded_hal_1::i2c::ErrorKind::Other, Self::Abort(AbortReason::Other(_)) => embedded_hal_1::i2c::ErrorKind::Other, Self::InvalidReadBufferLength => embedded_hal_1::i2c::ErrorKind::Other, Self::InvalidWriteBufferLength => embedded_hal_1::i2c::ErrorKind::Other, @@ -738,8 +741,8 @@ mod nightly { } } -fn i2c_reserved_addr(addr: u16) -> bool { - (addr & 0x78) == 0 || (addr & 0x78) == 0x78 +pub fn i2c_reserved_addr(addr: u16) -> bool { + ((addr & 0x78) == 0 || (addr & 0x78) == 0x78) && addr != 0 } mod sealed { diff --git a/embassy-rp/src/i2c_slave.rs b/embassy-rp/src/i2c_slave.rs new file mode 100644 index 00000000..6136d69c --- /dev/null +++ b/embassy-rp/src/i2c_slave.rs @@ -0,0 +1,338 @@ +use core::future; +use core::marker::PhantomData; +use core::task::Poll; + +use embassy_hal_internal::into_ref; +use pac::i2c; + +use crate::i2c::{i2c_reserved_addr, AbortReason, Instance, InterruptHandler, SclPin, SdaPin, FIFO_SIZE}; +use crate::interrupt::typelevel::{Binding, Interrupt}; +use crate::{pac, Peripheral}; + +/// I2C error +#[derive(Debug)] +#[cfg_attr(feature = "defmt", derive(defmt::Format))] +#[non_exhaustive] +pub enum Error { + /// I2C abort with error + Abort(AbortReason), + /// User passed in a response buffer that was 0 length + InvalidResponseBufferLength, +} + +/// Received command +#[derive(Debug, Copy, Clone, Eq, PartialEq)] +#[cfg_attr(feature = "defmt", derive(defmt::Format))] +pub enum Command { + /// General Call + GeneralCall(usize), + /// Read + Read, + /// Write+read + WriteRead(usize), + /// Write + Write(usize), +} + +/// Possible responses to responding to a read +#[derive(Debug, Copy, Clone, Eq, PartialEq)] +#[cfg_attr(feature = "defmt", derive(defmt::Format))] +pub enum ReadStatus { + /// Transaction Complete, controller naked our last byte + Done, + /// Transaction Incomplete, controller trying to read more bytes than were provided + NeedMoreBytes, + /// Transaction Complere, but controller stopped reading bytes before we ran out + LeftoverBytes(u16), +} + +/// Slave Configuration +#[non_exhaustive] +#[derive(Copy, Clone)] +#[cfg_attr(feature = "defmt", derive(defmt::Format))] +pub struct Config { + /// Target Address + pub addr: u16, +} + +impl Default for Config { + fn default() -> Self { + Self { addr: 0x55 } + } +} + +pub struct I2cSlave<'d, T: Instance> { + phantom: PhantomData<&'d mut T>, +} + +impl<'d, T: Instance> I2cSlave<'d, T> { + pub fn new( + _peri: impl Peripheral

+ 'd, + scl: impl Peripheral

> + 'd, + sda: impl Peripheral

> + 'd, + _irq: impl Binding>, + config: Config, + ) -> Self { + into_ref!(_peri, scl, sda); + + assert!(!i2c_reserved_addr(config.addr)); + assert!(config.addr != 0); + + let p = T::regs(); + + let reset = T::reset(); + crate::reset::reset(reset); + crate::reset::unreset_wait(reset); + + p.ic_enable().write(|w| w.set_enable(false)); + + p.ic_sar().write(|w| w.set_ic_sar(config.addr)); + p.ic_con().modify(|w| { + w.set_master_mode(false); + w.set_ic_slave_disable(false); + w.set_tx_empty_ctrl(true); + }); + + // Set FIFO watermarks to 1 to make things simpler. This is encoded + // by a register value of 0. Rx watermark should never change, but Tx watermark will be + // adjusted in operation. + p.ic_tx_tl().write(|w| w.set_tx_tl(0)); + p.ic_rx_tl().write(|w| w.set_rx_tl(0)); + + // Configure SCL & SDA pins + scl.gpio().ctrl().write(|w| w.set_funcsel(3)); + sda.gpio().ctrl().write(|w| w.set_funcsel(3)); + + scl.pad_ctrl().write(|w| { + w.set_schmitt(true); + w.set_ie(true); + w.set_od(false); + w.set_pue(true); + w.set_pde(false); + }); + sda.pad_ctrl().write(|w| { + w.set_schmitt(true); + w.set_ie(true); + w.set_od(false); + w.set_pue(true); + w.set_pde(false); + }); + + // Clear interrupts + p.ic_clr_intr().read(); + + // Enable I2C block + p.ic_enable().write(|w| w.set_enable(true)); + + // mask everything initially + p.ic_intr_mask().write_value(i2c::regs::IcIntrMask(0)); + T::Interrupt::unpend(); + unsafe { T::Interrupt::enable() }; + + Self { phantom: PhantomData } + } + + /// Calls `f` to check if we are ready or not. + /// If not, `g` is called once the waker is set (to eg enable the required interrupts). + #[inline(always)] + async fn wait_on(&mut self, mut f: F, mut g: G) -> U + where + F: FnMut(&mut Self) -> Poll, + G: FnMut(&mut Self), + { + future::poll_fn(|cx| { + let r = f(self); + + trace!("intr p: {:013b}", T::regs().ic_raw_intr_stat().read().0); + + if r.is_pending() { + T::waker().register(cx.waker()); + g(self); + } + + r + }) + .await + } + + #[inline(always)] + fn drain_fifo(&mut self, buffer: &mut [u8], offset: usize) -> usize { + let p = T::regs(); + let len = p.ic_rxflr().read().rxflr() as usize; + let end = offset + len; + for i in offset..end { + buffer[i] = p.ic_data_cmd().read().dat(); + } + end + } + + #[inline(always)] + fn write_to_fifo(&mut self, buffer: &[u8]) { + let p = T::regs(); + for byte in buffer { + p.ic_data_cmd().write(|w| w.set_dat(*byte)); + } + } + + /// Wait asynchronously for commands from an I2C master. + /// `buffer` is provided in case master does a 'write' and is unused for 'read'. + pub async fn listen(&mut self, buffer: &mut [u8]) -> Result { + let p = T::regs(); + + p.ic_clr_intr().read(); + // set rx fifo watermark to 1 byte + p.ic_rx_tl().write(|w| w.set_rx_tl(0)); + + let mut len = 0; + let ret = self + .wait_on( + |me| { + let stat = p.ic_raw_intr_stat().read(); + if p.ic_rxflr().read().rxflr() > 0 { + len = me.drain_fifo(buffer, len); + // we're recieving data, set rx fifo watermark to 12 bytes to reduce interrupt noise + p.ic_rx_tl().write(|w| w.set_rx_tl(11)); + } + + if stat.restart_det() && stat.rd_req() { + Poll::Ready(Ok(Command::WriteRead(len))) + } else if stat.gen_call() && stat.stop_det() && len > 0 { + Poll::Ready(Ok(Command::GeneralCall(len))) + } else if stat.stop_det() { + Poll::Ready(Ok(Command::Write(len))) + } else if stat.rd_req() { + Poll::Ready(Ok(Command::Read)) + } else { + Poll::Pending + } + }, + |_me| { + p.ic_intr_mask().modify(|w| { + w.set_m_stop_det(true); + w.set_m_restart_det(true); + w.set_m_gen_call(true); + w.set_m_rd_req(true); + w.set_m_rx_full(true); + }); + }, + ) + .await; + + p.ic_clr_intr().read(); + + ret + } + + /// Respond to an I2C master READ command, asynchronously. + pub async fn respond_to_read(&mut self, buffer: &[u8]) -> Result { + let p = T::regs(); + + if buffer.len() == 0 { + return Err(Error::InvalidResponseBufferLength); + } + + let mut chunks = buffer.chunks(FIFO_SIZE as usize); + + let ret = self + .wait_on( + |me| { + if let Err(abort_reason) = me.read_and_clear_abort_reason() { + if let Error::Abort(AbortReason::TxNotEmpty(bytes)) = abort_reason { + return Poll::Ready(Ok(ReadStatus::LeftoverBytes(bytes))); + } else { + return Poll::Ready(Err(abort_reason)); + } + } + + if let Some(chunk) = chunks.next() { + me.write_to_fifo(chunk); + + Poll::Pending + } else { + let stat = p.ic_raw_intr_stat().read(); + + if stat.rx_done() && stat.stop_det() { + Poll::Ready(Ok(ReadStatus::Done)) + } else if stat.rd_req() { + Poll::Ready(Ok(ReadStatus::NeedMoreBytes)) + } else { + Poll::Pending + } + } + }, + |_me| { + p.ic_intr_mask().modify(|w| { + w.set_m_stop_det(true); + w.set_m_rx_done(true); + w.set_m_tx_empty(true); + w.set_m_tx_abrt(true); + }) + }, + ) + .await; + + p.ic_clr_intr().read(); + + ret + } + + /// Respond to reads with the fill byte until the controller stops asking + pub async fn respond_till_stop(&mut self, fill: u8) -> Result<(), Error> { + loop { + match self.respond_to_read(&[fill]).await { + Ok(ReadStatus::NeedMoreBytes) => (), + Ok(_) => break Ok(()), + Err(e) => break Err(e), + } + } + } + + /// Respond to a master read, then fill any remaining read bytes with `fill` + pub async fn respond_and_fill(&mut self, buffer: &[u8], fill: u8) -> Result { + let resp_stat = self.respond_to_read(buffer).await?; + + if resp_stat == ReadStatus::NeedMoreBytes { + self.respond_till_stop(fill).await?; + Ok(ReadStatus::Done) + } else { + Ok(resp_stat) + } + } + + #[inline(always)] + fn read_and_clear_abort_reason(&mut self) -> Result<(), Error> { + let p = T::regs(); + let mut abort_reason = p.ic_tx_abrt_source().read(); + + // Mask off fifo flush count + let tx_flush_cnt = abort_reason.tx_flush_cnt(); + abort_reason.set_tx_flush_cnt(0); + + // Mask off master_dis + abort_reason.set_abrt_master_dis(false); + + if abort_reason.0 != 0 { + // Note clearing the abort flag also clears the reason, and this + // instance of flag is clear-on-read! Note also the + // IC_CLR_TX_ABRT register always reads as 0. + p.ic_clr_tx_abrt().read(); + + let reason = if abort_reason.abrt_7b_addr_noack() + | abort_reason.abrt_10addr1_noack() + | abort_reason.abrt_10addr2_noack() + { + AbortReason::NoAcknowledge + } else if abort_reason.arb_lost() { + AbortReason::ArbitrationLoss + } else if abort_reason.abrt_slvflush_txfifo() { + AbortReason::TxNotEmpty(tx_flush_cnt) + } else { + AbortReason::Other(abort_reason.0) + }; + + Err(Error::Abort(reason)) + } else { + Ok(()) + } + } +} diff --git a/embassy-rp/src/lib.rs b/embassy-rp/src/lib.rs index 49bd3533..2a1bca4b 100644 --- a/embassy-rp/src/lib.rs +++ b/embassy-rp/src/lib.rs @@ -16,6 +16,7 @@ pub mod flash; mod float; pub mod gpio; pub mod i2c; +pub mod i2c_slave; pub mod multicore; pub mod pwm; mod reset; diff --git a/examples/rp/src/bin/i2c_slave.rs b/examples/rp/src/bin/i2c_slave.rs new file mode 100644 index 00000000..7de300fb --- /dev/null +++ b/examples/rp/src/bin/i2c_slave.rs @@ -0,0 +1,118 @@ +//! This example shows how to use the 2040 as an i2c slave. +#![no_std] +#![no_main] +#![feature(type_alias_impl_trait)] + +use defmt::*; +use embassy_executor::Spawner; +use embassy_rp::peripherals::{I2C0, I2C1}; +use embassy_rp::{bind_interrupts, i2c, i2c_slave}; +use embassy_time::{Duration, Timer}; +use embedded_hal_async::i2c::I2c; +use {defmt_rtt as _, panic_probe as _}; + +bind_interrupts!(struct Irqs { + I2C0_IRQ => i2c::InterruptHandler; + I2C1_IRQ => i2c::InterruptHandler; +}); + +const DEV_ADDR: u8 = 0x42; + +#[embassy_executor::task] +async fn device_task(mut dev: i2c_slave::I2cSlave<'static, I2C1>) -> ! { + info!("Device start"); + + let mut state = 0; + + loop { + let mut buf = [0u8; 128]; + match dev.listen(&mut buf).await { + Ok(i2c_slave::Command::GeneralCall(len)) => info!("Device recieved general call write: {}", buf[..len]), + Ok(i2c_slave::Command::Read) => loop { + match dev.respond_to_read(&[state]).await { + Ok(x) => match x { + i2c_slave::ReadStatus::Done => break, + i2c_slave::ReadStatus::NeedMoreBytes => (), + i2c_slave::ReadStatus::LeftoverBytes(x) => { + info!("tried to write {} extra bytes", x); + break; + } + }, + Err(e) => error!("error while responding {}", e), + } + }, + Ok(i2c_slave::Command::Write(len)) => info!("Device recieved write: {}", buf[..len]), + Ok(i2c_slave::Command::WriteRead(len)) => { + info!("device recieved write read: {:x}", buf[..len]); + match buf[0] { + // Set the state + 0xC2 => { + state = buf[1]; + match dev.respond_and_fill(&[state], 0x00).await { + Ok(read_status) => info!("response read status {}", read_status), + Err(e) => error!("error while responding {}", e), + } + } + // Reset State + 0xC8 => { + state = 0; + match dev.respond_and_fill(&[state], 0x00).await { + Ok(read_status) => info!("response read status {}", read_status), + Err(e) => error!("error while responding {}", e), + } + } + x => error!("Invalid Write Read {:x}", x), + } + } + Err(e) => error!("{}", e), + } + } +} + +#[embassy_executor::task] +async fn controller_task(mut con: i2c::I2c<'static, I2C0, i2c::Async>) { + info!("Controller start"); + + loop { + let mut resp_buff = [0u8; 2]; + for i in 0..10 { + match con.write_read(DEV_ADDR, &[0xC2, i], &mut resp_buff).await { + Ok(_) => info!("write_read response: {}", resp_buff), + Err(e) => error!("Error writing {}", e), + } + + Timer::after(Duration::from_millis(100)).await; + } + match con.read(DEV_ADDR, &mut resp_buff).await { + Ok(_) => info!("read response: {}", resp_buff), + Err(e) => error!("Error writing {}", e), + } + match con.write_read(DEV_ADDR, &[0xC8], &mut resp_buff).await { + Ok(_) => info!("write_read response: {}", resp_buff), + Err(e) => error!("Error writing {}", e), + } + Timer::after(Duration::from_millis(100)).await; + } +} + +#[embassy_executor::main] +async fn main(spawner: Spawner) { + let p = embassy_rp::init(Default::default()); + info!("Hello World!"); + + let d_sda = p.PIN_3; + let d_scl = p.PIN_2; + let mut config = i2c_slave::Config::default(); + config.addr = DEV_ADDR as u16; + let device = i2c_slave::I2cSlave::new(p.I2C1, d_sda, d_scl, Irqs, config); + + unwrap!(spawner.spawn(device_task(device))); + + let c_sda = p.PIN_1; + let c_scl = p.PIN_0; + let mut config = i2c::Config::default(); + config.frequency = 5_000; + let controller = i2c::I2c::new_async(p.I2C0, c_sda, c_scl, Irqs, config); + + unwrap!(spawner.spawn(controller_task(controller))); +} diff --git a/tests/rp/src/bin/i2c.rs b/tests/rp/src/bin/i2c.rs new file mode 100644 index 00000000..425f2d08 --- /dev/null +++ b/tests/rp/src/bin/i2c.rs @@ -0,0 +1,212 @@ +#![no_std] +#![no_main] +#![feature(type_alias_impl_trait)] +teleprobe_meta::target!(b"rpi-pico"); + +use defmt::{assert_eq, info, panic, unwrap}; +use embassy_executor::Executor; +use embassy_executor::_export::StaticCell; +use embassy_rp::multicore::{spawn_core1, Stack}; +use embassy_rp::peripherals::{I2C0, I2C1}; +use embassy_rp::{bind_interrupts, i2c, i2c_slave}; +use embedded_hal_1::i2c::Operation; +use embedded_hal_async::i2c::I2c; +use {defmt_rtt as _, panic_probe as _, panic_probe as _, panic_probe as _}; + +static mut CORE1_STACK: Stack<1024> = Stack::new(); +static EXECUTOR0: StaticCell = StaticCell::new(); +static EXECUTOR1: StaticCell = StaticCell::new(); + +use crate::i2c::AbortReason; + +bind_interrupts!(struct Irqs { + I2C0_IRQ => i2c::InterruptHandler; + I2C1_IRQ => i2c::InterruptHandler; +}); + +const DEV_ADDR: u8 = 0x42; + +#[embassy_executor::task] +async fn device_task(mut dev: i2c_slave::I2cSlave<'static, I2C1>) -> ! { + info!("Device start"); + + let mut count = 0xD0; + + loop { + let mut buf = [0u8; 128]; + match dev.listen(&mut buf).await { + Ok(i2c_slave::Command::GeneralCall(len)) => { + assert_eq!(buf[..len], [0xCA, 0x11], "recieving the general call failed"); + info!("General Call - OK"); + } + Ok(i2c_slave::Command::Read) => { + loop { + match dev.respond_to_read(&[count]).await { + Ok(x) => match x { + i2c_slave::ReadStatus::Done => break, + i2c_slave::ReadStatus::NeedMoreBytes => count += 1, + i2c_slave::ReadStatus::LeftoverBytes(x) => { + info!("tried to write {} extra bytes", x); + break; + } + }, + Err(e) => match e { + embassy_rp::i2c_slave::Error::Abort(AbortReason::Other(n)) => panic!("Other {:b}", n), + _ => panic!("{}", e), + }, + } + } + count += 1; + } + Ok(i2c_slave::Command::Write(len)) => match len { + 1 => { + assert_eq!(buf[..len], [0xAA], "recieving a single byte failed"); + info!("Single Byte Write - OK") + } + 4 => { + assert_eq!(buf[..len], [0xAA, 0xBB, 0xCC, 0xDD], "recieving 4 bytes failed"); + info!("4 Byte Write - OK") + } + 32 => { + assert_eq!( + buf[..len], + [ + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, + 25, 26, 27, 28, 29, 30, 31 + ], + "recieving 32 bytes failed" + ); + info!("32 Byte Write - OK") + } + _ => panic!("Invalid write length {}", len), + }, + Ok(i2c_slave::Command::WriteRead(len)) => { + info!("device recieved write read: {:x}", buf[..len]); + match buf[0] { + 0xC2 => { + let resp_buff = [0xD1, 0xD2, 0xD3, 0xD4]; + dev.respond_to_read(&resp_buff).await.unwrap(); + } + 0xC8 => { + let mut resp_buff = [0u8; 32]; + for i in 0..32 { + resp_buff[i] = i as u8; + } + dev.respond_to_read(&resp_buff).await.unwrap(); + } + x => panic!("Invalid Write Read {:x}", x), + } + } + Err(e) => match e { + embassy_rp::i2c_slave::Error::Abort(AbortReason::Other(n)) => panic!("Other {:b}", n), + _ => panic!("{}", e), + }, + } + } +} + +#[embassy_executor::task] +async fn controller_task(mut con: i2c::I2c<'static, I2C0, i2c::Async>) { + info!("Device start"); + + { + let buf = [0xCA, 0x11]; + con.write(0u16, &buf).await.unwrap(); + info!("Controler general call write"); + embassy_futures::yield_now().await; + } + + { + let mut buf = [0u8]; + con.read(DEV_ADDR, &mut buf).await.unwrap(); + assert_eq!(buf, [0xD0], "single byte read failed"); + info!("single byte read - OK"); + embassy_futures::yield_now().await; + } + + { + let mut buf = [0u8; 4]; + con.read(DEV_ADDR, &mut buf).await.unwrap(); + assert_eq!(buf, [0xD1, 0xD2, 0xD3, 0xD4], "single byte read failed"); + info!("4 byte read - OK"); + embassy_futures::yield_now().await; + } + + { + let buf = [0xAA]; + con.write(DEV_ADDR, &buf).await.unwrap(); + info!("Controler single byte write"); + embassy_futures::yield_now().await; + } + + { + let buf = [0xAA, 0xBB, 0xCC, 0xDD]; + con.write(DEV_ADDR, &buf).await.unwrap(); + info!("Controler 4 byte write"); + embassy_futures::yield_now().await; + } + + { + let mut buf = [0u8; 32]; + for i in 0..32 { + buf[i] = i as u8; + } + con.write(DEV_ADDR, &buf).await.unwrap(); + info!("Controler 32 byte write"); + embassy_futures::yield_now().await; + } + + { + let mut buf = [0u8; 4]; + let mut ops = [Operation::Write(&[0xC2]), Operation::Read(&mut buf)]; + con.transaction(DEV_ADDR, &mut ops).await.unwrap(); + assert_eq!(buf, [0xD1, 0xD2, 0xD3, 0xD4], "write_read failed"); + info!("write_read - OK"); + embassy_futures::yield_now().await; + } + + { + let mut buf = [0u8; 32]; + let mut ops = [Operation::Write(&[0xC8]), Operation::Read(&mut buf)]; + con.transaction(DEV_ADDR, &mut ops).await.unwrap(); + assert_eq!( + buf, + [ + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, + 28, 29, 30, 31 + ], + "write_read of 32 bytes failed" + ); + info!("large write_read - OK") + } + + info!("Test OK"); + cortex_m::asm::bkpt(); +} + +#[cortex_m_rt::entry] +fn main() -> ! { + let p = embassy_rp::init(Default::default()); + info!("Hello World!"); + + let d_sda = p.PIN_19; + let d_scl = p.PIN_18; + let mut config = i2c_slave::Config::default(); + config.addr = DEV_ADDR as u16; + let device = i2c_slave::I2cSlave::new(p.I2C1, d_sda, d_scl, Irqs, config); + + spawn_core1(p.CORE1, unsafe { &mut CORE1_STACK }, move || { + let executor1 = EXECUTOR1.init(Executor::new()); + executor1.run(|spawner| unwrap!(spawner.spawn(device_task(device)))); + }); + + let executor0 = EXECUTOR0.init(Executor::new()); + + let c_sda = p.PIN_21; + let c_scl = p.PIN_20; + let mut config = i2c::Config::default(); + config.frequency = 5_000; + let controller = i2c::I2c::new_async(p.I2C0, c_sda, c_scl, Irqs, config); + + executor0.run(|spawner| unwrap!(spawner.spawn(controller_task(controller)))); +}