Begin reworking SPI to add DMA for stm32.

3 files changed, 57 insertions, 44 deletions

diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index 91b3d4ab3..f84d820b5 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -8,7 +8,6 @@ use crate::{dma, peripherals, rcc::RccPeripheral};
 pub use _version::*;
 
 use crate::gpio::Pin;
-use core::marker::PhantomData;
 
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
@@ -73,27 +72,12 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: sealed::Instance + RccPeripheral + 'static {}
-
-pub trait SckPin<T: Instance>: sealed::SckPin<T> + 'static {}
-
-pub trait MosiPin<T: Instance>: sealed::MosiPin<T> + 'static {}
-
-pub trait MisoPin<T: Instance>: sealed::MisoPin<T> + 'static {}
-
-pub trait TxDmaChannel<T: Instance>: sealed::TxDmaChannel<T> + 'static {}
-
-pub trait RxDmaChannel<T: Instance>: sealed::RxDmaChannel<T> + 'static {}
-
-pub trait SpiDma {}
-
-pub struct DmaPair<T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> {
-    tx: Tx,
-    rx: Rx,
-    _phantom: PhantomData<T>,
-}
-
-impl<T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> SpiDma for DmaPair<T, Tx, Rx> {}
+pub trait Instance: sealed::Instance + RccPeripheral {}
+pub trait SckPin<T: Instance>: sealed::SckPin<T> {}
+pub trait MosiPin<T: Instance>: sealed::MosiPin<T> {}
+pub trait MisoPin<T: Instance>: sealed::MisoPin<T> {}
+pub trait TxDmaChannel<T: Instance>: sealed::TxDmaChannel<T> + dma::Channel {}
+pub trait RxDmaChannel<T: Instance>: sealed::RxDmaChannel<T> + dma::Channel {}
 
 crate::pac::peripherals!(
     (spi, $inst:ident) => {
diff --git a/embassy-stm32/src/spi/v3.rs b/embassy-stm32/src/spi/v3.rs
index 2c6d4415f..6a6a01550 100644
--- a/embassy-stm32/src/spi/v3.rs
+++ b/embassy-stm32/src/spi/v3.rs
@@ -1,18 +1,21 @@
 #![macro_use]
 
+use crate::dma::NoDma;
 use crate::gpio::{AnyPin, Pin};
 use crate::pac::gpio::vals::{Afr, Moder};
 use crate::pac::gpio::Gpio;
 use crate::pac::spi;
 use crate::spi::{
-    ByteOrder, Config, DmaPair, Error, Instance, MisoPin, MosiPin, RxDmaChannel, SckPin, SpiDma,
-    TxDmaChannel, WordSize,
+    ByteOrder, Config, Error, Instance, MisoPin, MosiPin, RxDmaChannel, SckPin, TxDmaChannel,
+    WordSize,
 };
 use crate::time::Hertz;
+use core::future::Future;
 use core::marker::PhantomData;
 use core::ptr;
 use embassy::util::Unborrow;
 use embassy_extras::unborrow;
+use embassy_traits::spi as traits;
 pub use embedded_hal::spi::{Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3};
 
 impl WordSize {
@@ -31,28 +34,30 @@ impl WordSize {
     }
 }
 
-pub struct Spi<'d, T: Instance, D = NoDma> {
+pub struct Spi<'d, T: Instance, Tx = NoDma, Rx = NoDma> {
     sck: AnyPin,
     mosi: AnyPin,
     miso: AnyPin,
-    dma: D,
+    txdma: Tx,
+    rxdma: Rx,
     phantom: PhantomData<&'d mut T>,
 }
 
-impl<'d, T: Instance, D> Spi<'d, T, D> {
+impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     pub fn new<F>(
         _peri: impl Unborrow<Target = T> + 'd,
         sck: impl Unborrow<Target = impl SckPin<T>>,
         mosi: impl Unborrow<Target = impl MosiPin<T>>,
         miso: impl Unborrow<Target = impl MisoPin<T>>,
-        dma: impl Unborrow<Target = D>,
+        txdma: impl Unborrow<Target = Tx>,
+        rxdma: impl Unborrow<Target = Rx>,
         freq: F,
         config: Config,
     ) -> Self
     where
         F: Into<Hertz>,
     {
-        unborrow!(sck, mosi, miso, dma);
+        unborrow!(sck, mosi, miso, txdma, rxdma);
 
         unsafe {
             Self::configure_pin(sck.block(), sck.pin() as _, sck.af_num());
@@ -118,7 +123,8 @@ impl<'d, T: Instance, D> Spi<'d, T, D> {
             sck,
             mosi,
             miso,
-            dma,
+            txdma,
+            rxdma,
             phantom: PhantomData,
         }
     }
@@ -167,9 +173,21 @@ impl<'d, T: Instance, D> Spi<'d, T, D> {
             });
         }
     }
+
+    async fn write_dma_u8(&mut self, write: &[u8]) -> Result<(), Error> {
+        unimplemented!()
+    }
+
+    async fn read_dma_u8(&mut self, read: &mut [u8]) -> Result<(), Error> {
+        unimplemented!()
+    }
+
+    async fn read_write_dma_u8(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> {
+        unimplemented!()
+    }
 }
 
-impl<'d, T: Instance> Drop for Spi<'d, T> {
+impl<'d, T: Instance, Tx, Rx> Drop for Spi<'d, T, Tx, Rx> {
     fn drop(&mut self) {
         unsafe {
             Self::unconfigure_pin(self.sck.block(), self.sck.pin() as _);
@@ -364,30 +382,41 @@ impl<'d, T: Instance> embedded_hal::blocking::spi::Transfer<u16> for Spi<'d, T,
     }
 }
 
-use crate::dma::NoDma;
-use core::future::Future;
-use embassy_traits::spi::FullDuplex;
-
-#[rustfmt::skip]
-impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> FullDuplex<u8> for Spi<'d, T, DmaPair<T, Tx, Rx>> {
+impl<'d, T: Instance, Tx, Rx> traits::Spi<u8> for Spi<'d, T, Tx, Rx> {
     type Error = super::Error;
+}
+
+impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx> traits::Write<u8> for Spi<'d, T, Tx, Rx> {
+    #[rustfmt::skip]
     type WriteFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
+
+    fn write<'a>(&'a mut self, data: &'a [u8]) -> Self::WriteFuture<'a> {
+        self.write_dma_u8(data)
+    }
+}
+
+impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> traits::Read<u8>
+    for Spi<'d, T, Tx, Rx>
+{
+    #[rustfmt::skip]
     type ReadFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
-    type WriteReadFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
 
     fn read<'a>(&'a mut self, data: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        unimplemented!()
+        self.read_dma_u8(data)
     }
+}
 
-    fn write<'a>(&'a mut self, data: &'a [u8]) -> Self::WriteFuture<'a> {
-        unimplemented!()
-    }
+impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> traits::FullDuplex<u8>
+    for Spi<'d, T, Tx, Rx>
+{
+    #[rustfmt::skip]
+    type WriteReadFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
 
     fn read_write<'a>(
         &'a mut self,
         read: &'a mut [u8],
         write: &'a [u8],
     ) -> Self::WriteReadFuture<'a> {
-        unimplemented!()
+        self.read_write_dma_u8(read, write)
     }
 }
diff --git a/embassy-traits/src/spi.rs b/embassy-traits/src/spi.rs
index 961da38c4..9d044dfd3 100644
--- a/embassy-traits/src/spi.rs
+++ b/embassy-traits/src/spi.rs
@@ -44,7 +44,7 @@ pub trait Write<Word>: Spi<Word> {
     fn write<'a>(&'a mut self, data: &'a [Word]) -> Self::WriteFuture<'a>;
 }
 
-pub trait Read<Word>: Spi<Word> {
+pub trait Read<Word>: Write<Word> {
     type ReadFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
     where
         Self: 'a;