add async capture

2 files changed, 185 insertions, 8 deletions

diff --git a/embassy-stm32/src/timer/input_capture.rs b/embassy-stm32/src/timer/input_capture.rs
index bc7614cda..e5ec2505a 100644
--- a/embassy-stm32/src/timer/input_capture.rs
+++ b/embassy-stm32/src/timer/input_capture.rs
@@ -1,12 +1,17 @@
 //! Input capture driver.
 
+use core::future::Future;
 use core::marker::PhantomData;
+use core::pin::Pin;
+use core::task::{Context, Poll};
 
 use embassy_hal_internal::{into_ref, PeripheralRef};
 
 use super::low_level::{CountingMode, InputCaptureMode, InputTISelection, Timer};
+use super::CaptureCompareInterruptHandler;
 use super::{Channel, Channel1Pin, Channel2Pin, Channel3Pin, Channel4Pin, GeneralInstance4Channel};
 use crate::gpio::{AFType, AnyPin, Pull};
+use crate::interrupt::typelevel::{Binding, Interrupt};
 use crate::time::Hertz;
 use crate::Peripheral;
 
@@ -65,6 +70,7 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
         _ch2: Option<CapturePin<'d, T, Ch2>>,
         _ch3: Option<CapturePin<'d, T, Ch3>>,
         _ch4: Option<CapturePin<'d, T, Ch4>>,
+        _irq: impl Binding<T::CaptureCompareInterrupt, CaptureCompareInterruptHandler<T>> + 'd,
         freq: Hertz,
         counting_mode: CountingMode,
     ) -> Self {
@@ -79,13 +85,9 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
         this.inner.enable_outputs(); // Required for advanced timers, see GeneralInstance4Channel for details
         this.inner.start();
 
-        [Channel::Ch1, Channel::Ch2, Channel::Ch3, Channel::Ch4]
-            .iter()
-            .for_each(|&channel| {
-                this.inner.set_input_capture_mode(channel, InputCaptureMode::Rising);
-
-                this.inner.set_input_ti_selection(channel, InputTISelection::Normal);
-            });
+        // enable NVIC interrupt
+        T::CaptureCompareInterrupt::unpend();
+        unsafe { T::CaptureCompareInterrupt::enable() };
 
         this
     }
@@ -142,4 +144,88 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
     pub fn get_input_interrupt(&self, channel: Channel) -> bool {
         self.inner.get_input_interrupt(channel)
     }
+
+    fn new_future(&self, channel: Channel, mode: InputCaptureMode, tisel: InputTISelection) -> InputCaptureFuture<T> {
+        self.inner.enable_channel(channel, true);
+        self.inner.set_input_capture_mode(channel, mode);
+        self.inner.set_input_ti_selection(channel, tisel);
+        self.inner.clear_input_interrupt(channel);
+        self.inner.enable_input_interrupt(channel, true);
+
+        InputCaptureFuture {
+            channel,
+            phantom: PhantomData,
+        }
+    }
+
+    /// Asynchronously wait until the pin sees a rising edge.
+    pub async fn wait_for_rising_edge(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::Rising, InputTISelection::Normal)
+            .await
+    }
+
+    /// Asynchronously wait until the pin sees a falling edge.
+    pub async fn wait_for_falling_edge(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::Falling, InputTISelection::Normal)
+            .await
+    }
+
+    /// Asynchronously wait until the pin sees any edge.
+    pub async fn wait_for_any_edge(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::BothEdges, InputTISelection::Normal)
+            .await
+    }
+
+    /// Asynchronously wait until the (alternate) pin sees a rising edge.
+    pub async fn wait_for_rising_edge_alternate(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::Rising, InputTISelection::Alternate)
+            .await
+    }
+
+    /// Asynchronously wait until the (alternate) pin sees a falling edge.
+    pub async fn wait_for_falling_edge_alternate(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::Falling, InputTISelection::Alternate)
+            .await
+    }
+
+    /// Asynchronously wait until the (alternate) pin sees any edge.
+    pub async fn wait_for_any_edge_alternate(&mut self, channel: Channel) -> u32 {
+        self.new_future(channel, InputCaptureMode::BothEdges, InputTISelection::Alternate)
+            .await
+    }
+}
+
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+struct InputCaptureFuture<T: GeneralInstance4Channel> {
+    channel: Channel,
+    phantom: PhantomData<T>,
+}
+
+impl<T: GeneralInstance4Channel> Drop for InputCaptureFuture<T> {
+    fn drop(&mut self) {
+        critical_section::with(|_| {
+            let regs = unsafe { crate::pac::timer::TimGp16::from_ptr(T::regs()) };
+
+            // disable interrupt enable
+            regs.dier().modify(|w| w.set_ccie(self.channel.index(), false));
+        });
+    }
+}
+
+impl<T: GeneralInstance4Channel> Future for InputCaptureFuture<T> {
+    type Output = u32;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        T::state().cc_waker[self.channel.index()].register(cx.waker());
+
+        let regs = unsafe { crate::pac::timer::TimGp16::from_ptr(T::regs()) };
+
+        let dier = regs.dier().read();
+        if !dier.ccie(self.channel.index()) {
+            let val = regs.ccr(self.channel.index()).read().0;
+            Poll::Ready(val)
+        } else {
+            Poll::Pending
+        }
+    }
 }
diff --git a/embassy-stm32/src/timer/mod.rs b/embassy-stm32/src/timer/mod.rs
index 9a1fbcd61..4b4929aeb 100644
--- a/embassy-stm32/src/timer/mod.rs
+++ b/embassy-stm32/src/timer/mod.rs
@@ -1,5 +1,8 @@
 //! Timers, PWM, quadrature decoder.
 
+use core::marker::PhantomData;
+use embassy_sync::waitqueue::AtomicWaker;
+
 #[cfg(not(stm32l0))]
 pub mod complementary_pwm;
 pub mod input_capture;
@@ -46,8 +49,29 @@ pub enum TimerBits {
     Bits32,
 }
 
+struct State {
+    up_waker: AtomicWaker,
+    cc_waker: [AtomicWaker; 4],
+}
+
+impl State {
+    const fn new() -> Self {
+        const NEW_AW: AtomicWaker = AtomicWaker::new();
+        Self {
+            up_waker: NEW_AW,
+            cc_waker: [NEW_AW; 4],
+        }
+    }
+}
+
+trait SealedInstance: RccPeripheral {
+    /// Async state for this timer
+    fn state() -> &'static State;
+}
+
 /// Core timer instance.
-pub trait CoreInstance: RccPeripheral + 'static {
+#[allow(private_bounds)]
+pub trait CoreInstance: SealedInstance + 'static {
     /// Update Interrupt for this timer.
     type UpdateInterrupt: interrupt::typelevel::Interrupt;
 
@@ -144,6 +168,13 @@ dma_trait!(Ch4Dma, GeneralInstance4Channel);
 #[allow(unused)]
 macro_rules! impl_core_timer {
     ($inst:ident, $bits:expr) => {
+        impl SealedInstance for crate::peripherals::$inst {
+            fn state() -> &'static State {
+                static STATE: State = State::new();
+                &STATE
+            }
+        }
+
         impl CoreInstance for crate::peripherals::$inst {
             type UpdateInterrupt = crate::_generated::peripheral_interrupts::$inst::UP;
 
@@ -286,3 +317,63 @@ foreach_interrupt! {
         impl AdvancedInstance4Channel for crate::peripherals::$inst {}
     };
 }
+
+/// Update interrupt handler.
+pub struct UpdateInterruptHandler<T: CoreInstance> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: CoreInstance> interrupt::typelevel::Handler<T::UpdateInterrupt> for UpdateInterruptHandler<T> {
+    unsafe fn on_interrupt() {
+        #[cfg(feature = "low-power")]
+        crate::low_power::on_wakeup_irq();
+
+        let regs = crate::pac::timer::TimCore::from_ptr(T::regs());
+
+        // Read TIM interrupt flags.
+        let sr = regs.sr().read();
+
+        // Mask relevant interrupts (UIE).
+        let bits = sr.0 & 0x00000001;
+
+        // Mask all the channels that fired.
+        regs.dier().modify(|w| w.0 &= !bits);
+
+        // Wake the tasks
+        if sr.uif() {
+            T::state().up_waker.wake();
+        }
+    }
+}
+
+/// Capture/Compare interrupt handler.
+pub struct CaptureCompareInterruptHandler<T: GeneralInstance1Channel> {
+    _phantom: PhantomData<T>,
+}
+
+impl<T: GeneralInstance1Channel> interrupt::typelevel::Handler<T::CaptureCompareInterrupt>
+    for CaptureCompareInterruptHandler<T>
+{
+    unsafe fn on_interrupt() {
+        #[cfg(feature = "low-power")]
+        crate::low_power::on_wakeup_irq();
+
+        let regs = crate::pac::timer::TimGp16::from_ptr(T::regs());
+
+        // Read TIM interrupt flags.
+        let sr = regs.sr().read();
+
+        // Mask relevant interrupts (CCIE).
+        let bits = sr.0 & 0x0000001E;
+
+        // Mask all the channels that fired.
+        regs.dier().modify(|w| w.0 &= !bits);
+
+        // Wake the tasks
+        for ch in 0..4 {
+            if sr.ccif(ch) {
+                T::state().cc_waker[ch].wake();
+            }
+        }
+    }
+}