Add more options to DMA

2 files changed, 83 insertions, 7 deletions

diff --git a/embassy-stm32/src/dma/dma.rs b/embassy-stm32/src/dma/dma.rs
index 9f88c1141..0bce37e48 100644
--- a/embassy-stm32/src/dma/dma.rs
+++ b/embassy-stm32/src/dma/dma.rs
@@ -9,7 +9,7 @@ use crate::interrupt;
 use crate::pac;
 use crate::pac::dma::{regs, vals};
 
-use super::{Request, Word, WordSize};
+use super::{Burst, FlowControl, Request, TransferOptions, Word, WordSize};
 
 impl From<WordSize> for vals::Size {
     fn from(raw: WordSize) -> Self {
@@ -21,6 +21,26 @@ impl From<WordSize> for vals::Size {
     }
 }
 
+impl From<Burst> for vals::Burst {
+    fn from(burst: Burst) -> Self {
+        match burst {
+            Burst::Single => vals::Burst::SINGLE,
+            Burst::Incr4 => vals::Burst::INCR4,
+            Burst::Incr8 => vals::Burst::INCR8,
+            Burst::Incr16 => vals::Burst::INCR16,
+        }
+    }
+}
+
+impl From<FlowControl> for vals::Pfctrl {
+    fn from(flow: FlowControl) -> Self {
+        match flow {
+            FlowControl::Dma => vals::Pfctrl::DMA,
+            FlowControl::Peripheral => vals::Pfctrl::PERIPHERAL,
+        }
+    }
+}
+
 struct State {
     ch_wakers: [AtomicWaker; DMA_CHANNEL_COUNT],
 }
@@ -49,7 +69,7 @@ pub(crate) unsafe fn init() {
 foreach_dma_channel! {
     ($channel_peri:ident, $dma_peri:ident, dma, $channel_num:expr, $index:expr, $dmamux:tt) => {
         impl crate::dma::sealed::Channel for crate::peripherals::$channel_peri {
-            unsafe fn start_write<W: Word>(&mut self, request: Request, buf: *const [W], reg_addr: *mut W) {
+            unsafe fn start_write<W: Word>(&mut self, request: Request, buf: *const [W], reg_addr: *mut W, options: TransferOptions) {
                 let (ptr, len) = super::slice_ptr_parts(buf);
                 low_level_api::start_transfer(
                     pac::$dma_peri,
@@ -61,6 +81,7 @@ foreach_dma_channel! {
                     len,
                     true,
                     vals::Size::from(W::bits()),
+                    options,
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                     #[cfg(dmamux)]
@@ -68,7 +89,7 @@ foreach_dma_channel! {
                 )
             }
 
-            unsafe fn start_write_repeated<W: Word>(&mut self, request: Request, repeated: W, count: usize, reg_addr: *mut W) {
+            unsafe fn start_write_repeated<W: Word>(&mut self, request: Request, repeated: W, count: usize, reg_addr: *mut W, options: TransferOptions) {
                 let buf = [repeated];
                 low_level_api::start_transfer(
                     pac::$dma_peri,
@@ -80,6 +101,7 @@ foreach_dma_channel! {
                     count,
                     false,
                     vals::Size::from(W::bits()),
+                    options,
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                     #[cfg(dmamux)]
@@ -87,7 +109,7 @@ foreach_dma_channel! {
                 )
             }
 
-            unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *const W, buf: *mut [W]) {
+            unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *const W, buf: *mut [W], options: TransferOptions) {
                 let (ptr, len) = super::slice_ptr_parts_mut(buf);
                 low_level_api::start_transfer(
                     pac::$dma_peri,
@@ -99,6 +121,7 @@ foreach_dma_channel! {
                     len,
                     true,
                     vals::Size::from(W::bits()),
+                    options,
                     #[cfg(dmamux)]
                     <Self as super::dmamux::sealed::MuxChannel>::DMAMUX_REGS,
                     #[cfg(dmamux)]
@@ -146,6 +169,7 @@ mod low_level_api {
         mem_len: usize,
         incr_mem: bool,
         data_size: vals::Size,
+        options: TransferOptions,
         #[cfg(dmamux)] dmamux_regs: pac::dmamux::Dmamux,
         #[cfg(dmamux)] dmamux_ch_num: u8,
     ) {
@@ -180,6 +204,10 @@ mod low_level_api {
             #[cfg(dma_v2)]
             w.set_chsel(request);
 
+            w.set_pburst(options.pburst.into());
+            w.set_mburst(options.mburst.into());
+            w.set_pfctrl(options.flow_ctrl.into());
+
             w.set_en(true);
         });
     }
diff --git a/embassy-stm32/src/dma/mod.rs b/embassy-stm32/src/dma/mod.rs
index 4768a448c..f5b05589b 100644
--- a/embassy-stm32/src/dma/mod.rs
+++ b/embassy-stm32/src/dma/mod.rs
@@ -46,6 +46,7 @@ pub(crate) mod sealed {
             request: Request,
             buf: *const [W],
             reg_addr: *mut W,
+            options: TransferOptions,
         );
 
         /// Starts this channel for writing a word repeatedly.
@@ -58,6 +59,7 @@ pub(crate) mod sealed {
             repeated: W,
             count: usize,
             reg_addr: *mut W,
+            options: TransferOptions,
         );
 
         /// Starts this channel for reading a stream of words.
@@ -71,6 +73,7 @@ pub(crate) mod sealed {
             request: Request,
             reg_addr: *const W,
             buf: *mut [W],
+            options: TransferOptions,
         );
 
         /// Requests the channel to stop.
@@ -126,6 +129,43 @@ impl Word for u32 {
     }
 }
 
+pub enum Burst {
+    /// Single transfer
+    Single,
+    /// Incremental burst of 4 beats
+    Incr4,
+    /// Incremental burst of 8 beats
+    Incr8,
+    /// Incremental burst of 16 beats
+    Incr16,
+}
+
+pub enum FlowControl {
+    /// Flow control by DMA
+    Dma,
+    /// Flow control by peripheral
+    Peripheral,
+}
+
+pub struct TransferOptions {
+    /// Peripheral burst transfer configuration
+    pub pburst: Burst,
+    /// Memory burst transfer configuration
+    pub mburst: Burst,
+    /// Flow control configuration
+    pub flow_ctrl: FlowControl,
+}
+
+impl Default for TransferOptions {
+    fn default() -> Self {
+        Self {
+            pburst: Burst::Single,
+            mburst: Burst::Single,
+            flow_ctrl: FlowControl::Dma,
+        }
+    }
+}
+
 mod transfers {
     use super::*;
 
@@ -139,7 +179,7 @@ mod transfers {
         assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
         unborrow!(channel);
 
-        unsafe { channel.start_read::<W>(request, reg_addr, buf) };
+        unsafe { channel.start_read::<W>(request, reg_addr, buf, Default::default()) };
 
         Transfer::new(channel)
     }
@@ -154,7 +194,7 @@ mod transfers {
         assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
         unborrow!(channel);
 
-        unsafe { channel.start_write::<W>(request, buf, reg_addr) };
+        unsafe { channel.start_write::<W>(request, buf, reg_addr, Default::default()) };
 
         Transfer::new(channel)
     }
@@ -169,7 +209,15 @@ mod transfers {
     ) -> impl Future<Output = ()> + 'a {
         unborrow!(channel);
 
-        unsafe { channel.start_write_repeated::<W>(request, repeated, count, reg_addr) };
+        unsafe {
+            channel.start_write_repeated::<W>(
+                request,
+                repeated,
+                count,
+                reg_addr,
+                Default::default(),
+            )
+        };
 
         Transfer::new(channel)
     }