stm32/dma: simplify impls a bit.

2 files changed, 36 insertions, 39 deletions

diff --git a/embassy-stm32/src/dma/bdma.rs b/embassy-stm32/src/dma/bdma.rs
index 29c9fd592..b4c77757e 100644
--- a/embassy-stm32/src/dma/bdma.rs
+++ b/embassy-stm32/src/dma/bdma.rs
@@ -59,7 +59,7 @@ unsafe fn on_irq() {
                 let isr = pac::$dma.isr().read();
                 let dman = dma_num!($dma);
 
-                for chn in 0..crate::pac::dma_channels_count!($dma) {
+                for chn in 0..pac::dma_channels_count!($dma) {
                     let cr = pac::$dma.ch(chn).cr();
                     if isr.tcif(chn) && cr.read().tcie() {
                         cr.write(|_| ()); // Disable channel interrupts with the default value.
@@ -90,9 +90,8 @@ pac::dma_channels! {
         impl crate::dma::sealed::Channel for crate::peripherals::$channel_peri {
 
             unsafe fn start_write<W: Word>(&mut self, request: Request, buf: &[W], reg_addr: *mut W) {
-                low_level_api::reset_status(crate::pac::$dma_peri, $channel_num);
                 low_level_api::start_transfer(
-                    crate::pac::$dma_peri,
+                    pac::$dma_peri,
                     $channel_num,
                     #[cfg(any(bdma_v2, dmamux))]
                     request,
@@ -112,9 +111,8 @@ pac::dma_channels! {
 
             unsafe fn start_write_repeated<W: Word>(&mut self, request: Request, repeated: W, count: usize, reg_addr: *mut W) {
                 let buf = [repeated];
-                low_level_api::reset_status(crate::pac::$dma_peri, $channel_num);
                 low_level_api::start_transfer(
-                    crate::pac::$dma_peri,
+                    pac::$dma_peri,
                     $channel_num,
                     #[cfg(any(bdma_v2, dmamux))]
                     request,
@@ -132,9 +130,8 @@ pac::dma_channels! {
             }
 
             unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *mut W, buf: &mut [W]) {
-                low_level_api::reset_status(crate::pac::$dma_peri, $channel_num);
                 low_level_api::start_transfer(
-                    crate::pac::$dma_peri,
+                    pac::$dma_peri,
                     $channel_num,
                     #[cfg(any(bdma_v2, dmamux))]
                     request,
@@ -152,14 +149,14 @@ pac::dma_channels! {
             }
 
             fn request_stop(&mut self){
-                unsafe {low_level_api::request_stop(crate::pac::$dma_peri, $channel_num);}
+                unsafe {low_level_api::request_stop(pac::$dma_peri, $channel_num);}
             }
 
             fn is_running(&self) -> bool {
-                unsafe {low_level_api::is_running(crate::pac::$dma_peri, $channel_num)}
+                unsafe {low_level_api::is_running(pac::$dma_peri, $channel_num)}
             }
             fn remaining_transfers(&mut self) -> u16 {
-                unsafe {low_level_api::get_remaining_transfers(crate::pac::$dma_peri, $channel_num)}
+                unsafe {low_level_api::get_remaining_transfers(pac::$dma_peri, $channel_num)}
             }
 
             fn set_waker(&mut self, waker: &Waker) {
@@ -198,6 +195,8 @@ mod low_level_api {
     ) {
         let ch = dma.ch(channel_number as _);
 
+        reset_status(dma, channel_number);
+
         #[cfg(dmamux)]
         super::super::dmamux::configure_dmamux(dmamux_regs, dmamux_ch_num, request);
 
diff --git a/embassy-stm32/src/dma/dma.rs b/embassy-stm32/src/dma/dma.rs
index 05d62ef8f..efe4d1d9d 100644
--- a/embassy-stm32/src/dma/dma.rs
+++ b/embassy-stm32/src/dma/dma.rs
@@ -85,17 +85,15 @@ pac::dma_channels! {
     ($channel_peri:ident, $dma_peri:ident, dma, $channel_num:expr, $dmamux:tt) => {
         impl crate::dma::sealed::Channel for crate::peripherals::$channel_peri {
             unsafe fn start_write<W: Word>(&mut self, request: Request, buf: &[W], reg_addr: *mut W) {
-                let isrn = $channel_num as usize / 4;
-                let isrbit = $channel_num as usize % 4;
-                low_level_api::reset_status(&crate::pac::$dma_peri, isrn, isrbit);
                 low_level_api::start_transfer(
+                    pac::$dma_peri,
+                    $channel_num,
                     request,
                     vals::Dir::MEMORYTOPERIPHERAL,
                     reg_addr as *const u32,
                     buf.as_ptr() as *mut u32,
                     buf.len(),
                     true,
-                    crate::pac::$dma_peri.st($channel_num as _),
                     vals::Size::from(W::bits()),
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
@@ -106,17 +104,15 @@ pac::dma_channels! {
 
             unsafe fn start_write_repeated<W: Word>(&mut self, request: Request, repeated: W, count: usize, reg_addr: *mut W) {
                 let buf = [repeated];
-                let isrn = $channel_num as usize / 4;
-                let isrbit = $channel_num as usize % 4;
-                low_level_api::reset_status(&crate::pac::$dma_peri, isrn, isrbit);
                 low_level_api::start_transfer(
+                    pac::$dma_peri,
+                    $channel_num,
                     request,
                     vals::Dir::MEMORYTOPERIPHERAL,
                     reg_addr as *const u32,
                     buf.as_ptr() as *mut u32,
                     count,
                     false,
-                    crate::pac::$dma_peri.st($channel_num as _),
                     vals::Size::from(W::bits()),
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
@@ -126,17 +122,15 @@ pac::dma_channels! {
             }
 
             unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *mut W, buf: &mut [W]) {
-                let isrn = $channel_num as usize / 4;
-                let isrbit = $channel_num as usize % 4;
-                low_level_api::reset_status(&crate::pac::$dma_peri, isrn, isrbit);
                 low_level_api::start_transfer(
+                    pac::$dma_peri,
+                    $channel_num,
                     request,
                     vals::Dir::PERIPHERALTOMEMORY,
                     reg_addr as *const u32,
                     buf.as_ptr() as *mut u32,
                     buf.len(),
                     true,
-                    crate::pac::$dma_peri.st($channel_num as _),
                     vals::Size::from(W::bits()),
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
@@ -146,15 +140,15 @@ pac::dma_channels! {
             }
 
             fn request_stop(&mut self) {
-                unsafe {low_level_api::request_stop(&crate::pac::$dma_peri, $channel_num);}
+                unsafe {low_level_api::request_stop(pac::$dma_peri, $channel_num);}
             }
 
             fn is_running(&self) -> bool {
-                unsafe {low_level_api::is_running(&crate::pac::$dma_peri, $channel_num)}
+                unsafe {low_level_api::is_running(pac::$dma_peri, $channel_num)}
             }
 
             fn remaining_transfers(&mut self) -> u16 {
-                unsafe {low_level_api::get_remaining_transfers(&crate::pac::$dma_peri, $channel_num)}
+                unsafe {low_level_api::get_remaining_transfers(pac::$dma_peri, $channel_num)}
             }
 
             fn set_waker(&mut self, waker: &Waker) {
@@ -179,13 +173,14 @@ mod low_level_api {
     use super::*;
 
     pub unsafe fn start_transfer(
+        dma: pac::dma::Dma,
+        channel_number: u8,
         request: Request,
         dir: vals::Dir,
         peri_addr: *const u32,
         mem_addr: *mut u32,
         mem_len: usize,
         incr_mem: bool,
-        ch: crate::pac::dma::St,
         data_size: vals::Size,
         #[cfg(dmamux)] dmamux_regs: pac::dmamux::Dmamux,
         #[cfg(dmamux)] dmamux_ch_num: u8,
@@ -196,6 +191,9 @@ mod low_level_api {
         // "Preceding reads and writes cannot be moved past subsequent writes."
         fence(Ordering::SeqCst);
 
+        reset_status(dma, channel_number);
+
+        let ch = dma.st(channel_number as _);
         ch.par().write_value(peri_addr as u32);
         ch.m0ar().write_value(mem_addr as u32);
         ch.ndtr().write_value(regs::Ndtr(mem_len as _));
@@ -223,34 +221,31 @@ mod low_level_api {
     }
 
     /// Stops the DMA channel.
-    pub unsafe fn request_stop(dma: &pac::dma::Dma, channel_number: u8) {
-        // Reset status
-        let isrn = channel_number as usize / 4;
-        let isrbit = channel_number as usize % 4;
-        reset_status(dma, isrn, isrbit);
-
+    pub unsafe fn request_stop(dma: pac::dma::Dma, channel_number: u8) {
         // get a handle on the channel itself
         let ch = dma.st(channel_number as _);
 
-        // Disable the channel and interrupts with the default value.
-        ch.cr().write(|_| ());
+        // Disable the channel. Keep the IEs enabled so the irqs still fire.
+        ch.cr().write(|w| {
+            w.set_teie(true);
+            w.set_tcie(true);
+        });
 
         // "Subsequent reads and writes cannot be moved ahead of preceding reads."
         fence(Ordering::SeqCst);
     }
 
     /// Gets the running status of the channel
-    pub unsafe fn is_running(dma: &pac::dma::Dma, ch: u8) -> bool {
+    pub unsafe fn is_running(dma: pac::dma::Dma, ch: u8) -> bool {
         // get a handle on the channel itself
         let ch = dma.st(ch as _);
-
-        // Wait for the transfer to complete when it was ongoing.
+        // Get whether it's enabled (running)
         ch.cr().read().en()
     }
 
     /// Gets the total remaining transfers for the channel
     /// Note: this will be zero for transfers that completed without cancellation.
-    pub unsafe fn get_remaining_transfers(dma: &pac::dma::Dma, ch: u8) -> u16 {
+    pub unsafe fn get_remaining_transfers(dma: pac::dma::Dma, ch: u8) -> u16 {
         // get a handle on the channel itself
         let ch = dma.st(ch as _);
         // read the remaining transfer count. If this is zero, the transfer completed fully.
@@ -262,7 +257,10 @@ mod low_level_api {
         STATE.ch_wakers[state_number].register(waker);
     }
 
-    pub unsafe fn reset_status(dma: &crate::pac::dma::Dma, isrn: usize, isrbit: usize) {
+    pub unsafe fn reset_status(dma: pac::dma::Dma, channel_number: u8) {
+        let isrn = channel_number as usize / 4;
+        let isrbit = channel_number as usize % 4;
+
         dma.ifcr(isrn).write(|w| {
             w.set_tcif(isrbit, true);
             w.set_teif(isrbit, true);