From 3655048e0f8238dc64425ff79d9cf951b9b1f340 Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Sat, 17 Jul 2021 07:49:49 +0200
Subject: [PATCH] stm32/dma: add MuxChannel trait to distinguish DMAMUX1 and
 DMAMUX2 channels.

---
 embassy-stm32/src/dma/bdma.rs   |  8 ++++----
 embassy-stm32/src/dma/dma.rs    |  8 ++++----
 embassy-stm32/src/dma/dmamux.rs | 22 ++++++++++++++++++----
 embassy-stm32/src/dma/mod.rs    |  3 +++
 embassy-stm32/src/usart/mod.rs  | 10 ++++++++--
 5 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/embassy-stm32/src/dma/bdma.rs b/embassy-stm32/src/dma/bdma.rs
index 3d9ff9eb..4c26a950 100644
--- a/embassy-stm32/src/dma/bdma.rs
+++ b/embassy-stm32/src/dma/bdma.rs
@@ -175,9 +175,9 @@ pac::dma_channels! {
                         buf.as_mut_ptr(),
                         buf.len(),
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_REGS,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_CH_NUM,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_CH_NUM,
                     )
                 }
             }
@@ -199,9 +199,9 @@ pac::dma_channels! {
                         buf.as_ptr() as *mut u8,
                         buf.len(),
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_REGS,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_CH_NUM,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_CH_NUM,
                     )
                 }
             }
diff --git a/embassy-stm32/src/dma/dma.rs b/embassy-stm32/src/dma/dma.rs
index 9b1c1160..75fc1403 100644
--- a/embassy-stm32/src/dma/dma.rs
+++ b/embassy-stm32/src/dma/dma.rs
@@ -177,9 +177,9 @@ pac::dma_channels! {
                         buf.as_mut_ptr(),
                         buf.len(),
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_REGS,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_CH_NUM,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_CH_NUM,
                     )
                 }
             }
@@ -201,9 +201,9 @@ pac::dma_channels! {
                         buf.as_ptr() as *mut u8,
                         buf.len(),
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_REGS,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                         #[cfg(dmamux)]
-                        <Self as super::dmamux::MuxChannel>::DMAMUX_CH_NUM,
+                        <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_CH_NUM,
                     )
                 }
             }
diff --git a/embassy-stm32/src/dma/dmamux.rs b/embassy-stm32/src/dma/dmamux.rs
index 186ec247..718859a4 100644
--- a/embassy-stm32/src/dma/dmamux.rs
+++ b/embassy-stm32/src/dma/dmamux.rs
@@ -19,17 +19,31 @@ pub(crate) unsafe fn configure_dmamux(
     });
 }
 
-pub(crate) trait MuxChannel {
-    const DMAMUX_CH_NUM: u8;
-    const DMAMUX_REGS: pac::dmamux::Dmamux;
+pub(crate) mod sealed {
+    use super::*;
+    pub trait MuxChannel {
+        const DMAMUX_CH_NUM: u8;
+        const DMAMUX_REGS: pac::dmamux::Dmamux;
+    }
+}
+
+pub struct DMAMUX1;
+#[cfg(rcc_h7)]
+pub struct DMAMUX2;
+
+pub trait MuxChannel: sealed::MuxChannel + super::Channel {
+    type Mux;
 }
 
 pac::dma_channels! {
     ($channel_peri:ident, $dma_peri:ident, $version:ident, $channel_num:expr, {dmamux: $dmamux:ident, dmamux_channel: $dmamux_channel:expr}) => {
-        impl MuxChannel for peripherals::$channel_peri {
+        impl sealed::MuxChannel for peripherals::$channel_peri {
             const DMAMUX_CH_NUM: u8 = $dmamux_channel;
             const DMAMUX_REGS: pac::dmamux::Dmamux = pac::$dmamux;
         }
+        impl MuxChannel for peripherals::$channel_peri {
+            type Mux = $dmamux;
+        }
     };
 }
 
diff --git a/embassy-stm32/src/dma/mod.rs b/embassy-stm32/src/dma/mod.rs
index ebad3d7b..fbf82b87 100644
--- a/embassy-stm32/src/dma/mod.rs
+++ b/embassy-stm32/src/dma/mod.rs
@@ -5,6 +5,9 @@ mod dma;
 #[cfg(dmamux)]
 mod dmamux;
 
+#[cfg(dmamux)]
+pub use dmamux::*;
+
 use core::future::Future;
 use embassy::util::Unborrow;
 
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index 92021d0a..9df00d3a 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -172,13 +172,19 @@ crate::pac::peripheral_pins!(
 
 macro_rules! impl_dma {
     ($inst:ident, {dmamux: $dmamux:ident}, $signal:ident, $request:expr) => {
-        impl<T: crate::dma::Channel> sealed::$signal<peripherals::$inst> for T {
+        impl<T> sealed::$signal<peripherals::$inst> for T
+        where
+            T: crate::dma::MuxChannel<Mux = crate::dma::$dmamux>,
+        {
             fn request(&self) -> dma::Request {
                 $request
             }
         }
 
-        impl<T: crate::dma::Channel> $signal<peripherals::$inst> for T {}
+        impl<T> $signal<peripherals::$inst> for T where
+            T: crate::dma::MuxChannel<Mux = crate::dma::$dmamux>
+        {
+        }
     };
     ($inst:ident, {channel: $channel:ident}, $signal:ident, $request:expr) => {
         impl sealed::$signal<peripherals::$inst> for peripherals::$channel {