STM: Start working on bdma-v1

4 files changed, 295 insertions, 54 deletions

diff --git a/embassy-stm32/src/bdma/mod.rs b/embassy-stm32/src/bdma/mod.rs
index e85ade5df..1a49f4e1d 100644
--- a/embassy-stm32/src/bdma/mod.rs
+++ b/embassy-stm32/src/bdma/mod.rs
@@ -7,63 +7,24 @@ mod _version;
 #[allow(unused)]
 pub use _version::*;
 
-use crate::pac;
-use crate::peripherals;
+use core::future::Future;
 
-pub(crate) mod sealed {
-    use super::*;
+pub trait WriteDma<T> {
+    type WriteDmaFuture<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
-    pub trait Channel {
-        fn num(&self) -> u8;
-
-        fn dma_num(&self) -> u8 {
-            self.num() / 8
-        }
-        fn ch_num(&self) -> u8 {
-            self.num() % 8
-        }
-        fn regs(&self) -> pac::dma::Dma {
-            pac::DMA(self.num() as _)
-        }
-    }
+    fn transfer<'a>(&'a mut self, buf: &'a [u8], dst: *mut u8) -> Self::WriteDmaFuture<'a>
+    where
+        T: 'a;
 }
 
-pub trait Channel: sealed::Channel + Sized {}
+pub trait ReadDma<T> {
+    type ReadDmaFuture<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
-macro_rules! impl_dma_channel {
-    ($channel_peri:ident, $dma_num:expr, $ch_num:expr) => {
-        impl Channel for peripherals::$channel_peri {}
-        impl sealed::Channel for peripherals::$channel_peri {
-            #[inline]
-            fn num(&self) -> u8 {
-                $dma_num * 8 + $ch_num
-            }
-        }
-    };
+    fn transfer<'a>(&'a mut self, src: *const u8, buf: &'a mut [u8]) -> Self::ReadDmaFuture<'a>
+    where
+        T: 'a;
 }
-
-/*
-crate::pac::peripherals!(
-    (dma,DMA1) => {
-        impl_dma_channel!(DMA1_CH0, 0, 0);
-        impl_dma_channel!(DMA1_CH1, 0, 1);
-        impl_dma_channel!(DMA1_CH2, 0, 2);
-        impl_dma_channel!(DMA1_CH3, 0, 3);
-        impl_dma_channel!(DMA1_CH4, 0, 4);
-        impl_dma_channel!(DMA1_CH5, 0, 5);
-        impl_dma_channel!(DMA1_CH6, 0, 6);
-        impl_dma_channel!(DMA1_CH7, 0, 7);
-    };
-
-    (dma,DMA2) => {
-        impl_dma_channel!(DMA2_CH0, 1, 0);
-        impl_dma_channel!(DMA2_CH1, 1, 1);
-        impl_dma_channel!(DMA2_CH2, 1, 2);
-        impl_dma_channel!(DMA2_CH3, 1, 3);
-        impl_dma_channel!(DMA2_CH4, 1, 4);
-        impl_dma_channel!(DMA2_CH5, 1, 5);
-        impl_dma_channel!(DMA2_CH6, 1, 6);
-        impl_dma_channel!(DMA2_CH7, 1, 7);
-    };
-);
- */
diff --git a/embassy-stm32/src/bdma/v1.rs b/embassy-stm32/src/bdma/v1.rs
new file mode 100644
index 000000000..584d531f7
--- /dev/null
+++ b/embassy-stm32/src/bdma/v1.rs
@@ -0,0 +1,275 @@
+use core::future::Future;
+use core::task::Poll;
+
+use atomic_polyfill::{AtomicU8, Ordering};
+use embassy::interrupt::{Interrupt, InterruptExt};
+use embassy::util::{AtomicWaker, OnDrop};
+use futures::future::poll_fn;
+
+use super::{ReadDma, WriteDma};
+use crate::interrupt;
+use crate::pac;
+use crate::pac::bdma::vals;
+
+const CH_COUNT: usize = pac::peripheral_count!(DMA) * 8;
+const CH_STATUS_NONE: u8 = 0;
+const CH_STATUS_COMPLETED: u8 = 1;
+const CH_STATUS_ERROR: u8 = 2;
+
+struct State {
+    ch_wakers: [AtomicWaker; CH_COUNT],
+    ch_status: [AtomicU8; CH_COUNT],
+}
+
+impl State {
+    const fn new() -> Self {
+        const AW: AtomicWaker = AtomicWaker::new();
+        const AU: AtomicU8 = AtomicU8::new(CH_STATUS_NONE);
+        Self {
+            ch_wakers: [AW; CH_COUNT],
+            ch_status: [AU; CH_COUNT],
+        }
+    }
+}
+
+static STATE: State = State::new();
+
+#[allow(unused)]
+pub(crate) async unsafe fn transfer_p2m(ch: &mut impl Channel, src: *const u8, dst: &mut [u8]) {
+    // ndtr is max 16 bits.
+    assert!(dst.len() <= 0xFFFF);
+
+    let regs: pac::bdma::Ch = ch.regs();
+    let state_number = ch.state_num();
+
+    // Reset status
+    // Generate a DMB here to flush the store buffer (M7) before enabling the DMA
+    STATE.ch_status[state_number].store(CH_STATUS_NONE, Ordering::Release);
+
+    let on_drop = OnDrop::new(|| unsafe {
+        regs.cr().modify(|w| {
+            w.set_tcie(false);
+            w.set_teie(false);
+            w.set_en(false);
+        });
+        while regs.cr().read().en() {}
+    });
+
+    regs.par().write_value(src as u32);
+    regs.mar().write_value(dst.as_mut_ptr() as u32);
+    regs.ndtr().write(|w| w.set_ndt(dst.len() as u16));
+    regs.cr().write(|w| {
+        w.set_psize(vals::Size::BITS8);
+        w.set_msize(vals::Size::BITS8);
+        w.set_minc(vals::Inc::ENABLED);
+        w.set_teie(true);
+        w.set_tcie(true);
+        w.set_en(true);
+    });
+
+    let res = poll_fn(|cx| {
+        STATE.ch_wakers[state_number].register(cx.waker());
+        match STATE.ch_status[state_number].load(Ordering::Acquire) {
+            CH_STATUS_NONE => Poll::Pending,
+            x => Poll::Ready(x),
+        }
+    })
+    .await;
+
+    on_drop.defuse();
+    // TODO handle error
+    assert!(res == CH_STATUS_COMPLETED);
+}
+
+#[allow(unused)]
+pub(crate) async unsafe fn transfer_m2p(ch: &mut impl Channel, src: &[u8], dst: *mut u8) {
+    // ndtr is max 16 bits.
+    assert!(src.len() <= 0xFFFF);
+
+    let regs: pac::bdma::Ch = ch.regs();
+    let state_number = ch.state_num();
+
+    // Reset status
+    // Generate a DMB here to flush the store buffer (M7) before enabling the DMA
+    STATE.ch_status[state_number].store(CH_STATUS_NONE, Ordering::Release);
+
+    let on_drop = OnDrop::new(|| unsafe {
+        regs.cr().modify(|w| {
+            w.set_tcie(false);
+            w.set_teie(false);
+            w.set_en(false);
+        });
+        while regs.cr().read().en() {}
+    });
+
+    regs.par().write_value(dst as u32);
+    regs.mar().write_value(src.as_ptr() as u32);
+    regs.ndtr().write(|w| w.set_ndt(src.len() as u16));
+    regs.cr().write(|w| {
+        w.set_psize(vals::Size::BITS8);
+        w.set_msize(vals::Size::BITS8);
+        w.set_minc(vals::Inc::ENABLED);
+        w.set_dir(vals::Dir::FROMMEMORY);
+        w.set_teie(true);
+        w.set_tcie(true);
+        w.set_en(true);
+    });
+
+    let res = poll_fn(|cx| {
+        STATE.ch_wakers[state_number].register(cx.waker());
+        match STATE.ch_status[state_number].load(Ordering::Acquire) {
+            CH_STATUS_NONE => Poll::Pending,
+            x => Poll::Ready(x),
+        }
+    })
+    .await;
+
+    on_drop.defuse();
+    // TODO handle error
+    assert!(res == CH_STATUS_COMPLETED);
+}
+
+unsafe fn on_irq() {
+    pac::peripherals! {
+        (bdma, $dma:ident) => {
+                let isr = pac::$dma.isr().read();
+                pac::$dma.ifcr().write_value(isr);
+                let dman = <crate::peripherals::$dma as sealed::Dma>::num() as usize;
+
+                for chn in 0..7 {
+                    let n = dman * 8 + chn;
+                    if isr.teif(chn) {
+                        STATE.ch_status[n].store(CH_STATUS_ERROR, Ordering::Relaxed);
+                        STATE.ch_wakers[n].wake();
+                    } else if isr.tcif(chn) {
+                        STATE.ch_status[n].store(CH_STATUS_COMPLETED, Ordering::Relaxed);
+                        STATE.ch_wakers[n].wake();
+                    }
+                }
+
+        };
+    }
+}
+
+/// safety: must be called only once
+pub(crate) unsafe fn init() {
+    pac::interrupts! {
+        (DMA, $irq:ident) => {
+            crate::interrupt::$irq::steal().enable();
+        };
+    }
+}
+
+pub(crate) mod sealed {
+    use super::*;
+
+    pub trait Dma {
+        fn num() -> u8;
+    }
+
+    pub trait Channel {
+        fn dma_regs() -> &'static pac::bdma::Dma;
+
+        fn state_num(&self) -> usize;
+
+        fn ch_num(&self) -> u8;
+
+        fn regs(&self) -> pac::bdma::Ch {
+            Self::dma_regs().ch(self.ch_num() as usize)
+        }
+    }
+}
+
+pub trait Dma: sealed::Dma + Sized {}
+pub trait Channel: sealed::Channel + Sized {}
+
+macro_rules! impl_dma {
+    ($peri:ident, $num:expr) => {
+        impl Dma for crate::peripherals::$peri {}
+        impl sealed::Dma for crate::peripherals::$peri {
+            fn num() -> u8 {
+                $num
+            }
+        }
+    };
+}
+
+macro_rules! impl_dma_channel {
+    ($channel_peri:ident, $dma_peri:ident, $dma_num:expr, $ch_num:expr) => {
+        impl Channel for crate::peripherals::$channel_peri {}
+        impl sealed::Channel for crate::peripherals::$channel_peri {
+            #[inline]
+            fn dma_regs() -> &'static pac::bdma::Dma {
+                &crate::pac::$dma_peri
+            }
+
+            fn state_num(&self) -> usize {
+                ($dma_num * 8) + $ch_num
+            }
+
+            fn ch_num(&self) -> u8 {
+                $ch_num
+            }
+        }
+
+        impl<T> WriteDma<T> for crate::peripherals::$channel_peri
+        where
+            T: 'static,
+        {
+            type WriteDmaFuture<'a> = impl Future<Output = ()>;
+
+            fn transfer<'a>(&'a mut self, buf: &'a [u8], dst: *mut u8) -> Self::WriteDmaFuture<'a>
+            where
+                T: 'a,
+            {
+                unsafe { transfer_m2p(self, buf, dst) }
+            }
+        }
+
+        impl<T> ReadDma<T> for crate::peripherals::$channel_peri
+        where
+            T: 'static,
+        {
+            type ReadDmaFuture<'a> = impl Future<Output = ()>;
+
+            fn transfer<'a>(
+                &'a mut self,
+                src: *const u8,
+                buf: &'a mut [u8],
+            ) -> Self::ReadDmaFuture<'a>
+            where
+                T: 'a,
+            {
+                unsafe { transfer_p2m(self, src, buf) }
+            }
+        }
+    };
+}
+
+pac::peripherals! {
+    (bdma, DMA1) => {
+        impl_dma!(DMA1, 0);
+        pac::dma_channels! {
+            ($channel_peri:ident, DMA1, $channel_num:expr) => {
+                impl_dma_channel!($channel_peri, DMA1, 0, $channel_num);
+            };
+        }
+    };
+    (bdma, DMA2) => {
+        impl_dma!(DMA2, 1);
+        pac::dma_channels! {
+            ($channel_peri:ident, DMA2, $channel_num:expr) => {
+                impl_dma_channel!($channel_peri, DMA2, 1, $channel_num);
+            };
+        }
+    };
+}
+
+pac::interrupts! {
+    (DMA, $irq:ident) => {
+        #[crate::interrupt]
+        unsafe fn $irq () {
+            on_irq()
+        }
+    };
+}
diff --git a/embassy-stm32/src/bdma/v2.rs b/embassy-stm32/src/bdma/v2.rs
new file mode 100644
index 000000000..8b1378917
--- /dev/null
+++ b/embassy-stm32/src/bdma/v2.rs
@@ -0,0 +1 @@
+
diff --git a/embassy-stm32/src/lib.rs b/embassy-stm32/src/lib.rs
index 76a6ecd88..35a8d3baf 100644
--- a/embassy-stm32/src/lib.rs
+++ b/embassy-stm32/src/lib.rs
@@ -22,6 +22,8 @@ pub mod rcc;
 // Sometimes-present hardware
 #[cfg(adc)]
 pub mod adc;
+#[cfg(bdma)]
+pub mod bdma;
 #[cfg(timer)]
 pub mod clock;
 #[cfg(dac)]
@@ -86,6 +88,8 @@ pub fn init(config: Config) -> Peripherals {
     unsafe {
         #[cfg(dma)]
         dma::init();
+        #[cfg(bdma)]
+        bdma::init();
         #[cfg(exti)]
         exti::init();
         rcc::init(config.rcc);