blah

embassy-hal-common/src/atomic_ring_buffer.rs

@@ -0,0 +1,154 @@
+use core::slice;
+use core::sync::atomic::{AtomicPtr, AtomicUsize, Ordering};
+
+pub struct RingBuffer {
+    buf: AtomicPtr<u8>,
+    len: AtomicUsize,
+    start: AtomicUsize,
+    end: AtomicUsize,
+}
+
+pub struct Reader<'a>(&'a RingBuffer);
+pub struct Writer<'a>(&'a RingBuffer);
+
+impl RingBuffer {
+    pub const fn new() -> Self {
+        Self {
+            buf: AtomicPtr::new(core::ptr::null_mut()),
+            len: AtomicUsize::new(0),
+            start: AtomicUsize::new(0),
+            end: AtomicUsize::new(0),
+        }
+    }
+
+    /// # Safety
+    /// - The buffer (`buf .. buf+len`) must be valid memory until `deinit` is called.
+    /// - Must not be called concurrently with any other methods.
+    pub unsafe fn init(&self, buf: *mut u8, len: usize) {
+        self.buf.store(buf, Ordering::Relaxed);
+        self.len.store(len, Ordering::Relaxed);
+        self.start.store(0, Ordering::Relaxed);
+        self.end.store(0, Ordering::Relaxed);
+    }
+
+    pub unsafe fn deinit(&self) {
+        self.len.store(0, Ordering::Relaxed);
+    }
+
+    pub unsafe fn reader(&self) -> Reader<'_> {
+        Reader(self)
+    }
+
+    pub unsafe fn writer(&self) -> Writer<'_> {
+        Writer(self)
+    }
+
+    pub fn is_full(&self) -> bool {
+        let start = self.start.load(Ordering::Relaxed);
+        let end = self.end.load(Ordering::Relaxed);
+
+        self.wrap(end + 1) == start
+    }
+
+    pub fn is_empty(&self) -> bool {
+        let start = self.start.load(Ordering::Relaxed);
+        let end = self.end.load(Ordering::Relaxed);
+
+        start == end
+    }
+
+    pub fn wrap(&self, n: usize) -> usize {
+        let len = self.len.load(Ordering::Relaxed);
+
+        assert!(n <= len);
+        if n == len {
+            0
+        } else {
+            n
+        }
+    }
+}
+
+impl<'a> Writer<'a> {
+    pub fn push(&self, f: impl FnOnce(&mut [u8]) -> usize) -> usize {
+        let (p, n) = self.push_buf();
+        let buf = unsafe { slice::from_raw_parts_mut(p, n) };
+        let n = f(buf);
+        self.push_done(n);
+        n
+    }
+
+    pub fn push_one(&self, val: u8) -> bool {
+        let n = self.push(|f| match f {
+            [] => 0,
+            [x, ..] => {
+                *x = val;
+                1
+            }
+        });
+        n != 0
+    }
+
+    pub fn push_buf(&self) -> (*mut u8, usize) {
+        let start = self.0.start.load(Ordering::Acquire);
+        let buf = self.0.buf.load(Ordering::Relaxed);
+        let len = self.0.len.load(Ordering::Relaxed);
+        let end = self.0.end.load(Ordering::Relaxed);
+
+        let n = if start <= end {
+            len - end - (start == 0) as usize
+        } else {
+            start - end - 1
+        };
+
+        trace!("  ringbuf: push_buf {:?}..{:?}", end, end + n);
+        (unsafe { buf.add(end) }, n)
+    }
+
+    pub fn push_done(&self, n: usize) {
+        trace!("  ringbuf: push {:?}", n);
+        let end = self.0.end.load(Ordering::Relaxed);
+        self.0.end.store(self.0.wrap(end + n), Ordering::Release);
+    }
+}
+
+impl<'a> Reader<'a> {
+    pub fn pop(&self, f: impl FnOnce(&[u8]) -> usize) -> usize {
+        let (p, n) = self.pop_buf();
+        let buf = unsafe { slice::from_raw_parts(p, n) };
+        let n = f(buf);
+        self.pop_done(n);
+        n
+    }
+
+    pub fn pop_one(&self) -> Option<u8> {
+        let mut res = None;
+        self.pop(|f| match f {
+            &[] => 0,
+            &[x, ..] => {
+                res = Some(x);
+                1
+            }
+        });
+        res
+    }
+
+    pub fn pop_buf(&self) -> (*mut u8, usize) {
+        let end = self.0.end.load(Ordering::Acquire);
+        let buf = self.0.buf.load(Ordering::Relaxed);
+        let len = self.0.len.load(Ordering::Relaxed);
+        let start = self.0.start.load(Ordering::Relaxed);
+
+        let n = if end < start { len - start } else { end - start };
+
+        trace!("  ringbuf: pop_buf {:?}..{:?}", start, start + n);
+        (unsafe { buf.add(start) }, n)
+    }
+
+    pub fn pop_done(&self, n: usize) {
+        trace!("  ringbuf: pop {:?}", n);
+
+        let start = self.0.start.load(Ordering::Relaxed);
+        self.0.start.store(self.0.wrap(start + n), Ordering::Release);
+    }
+}

embassy-hal-common/src/lib.rs

@@ -4,6 +4,7 @@
 // This mod MUST go first, so that the others see its macros.
 pub(crate) mod fmt;
 
+pub mod atomic_ring_buffer;
 pub mod drop;
 mod macros;
 mod peripheral;

embassy-rp/src/interrupt.rs

@@ -34,3 +34,27 @@ declare!(ADC_IRQ_FIFO);
 declare!(I2C0_IRQ);
 declare!(I2C1_IRQ);
 declare!(RTC_IRQ);
+
+pub trait InterruptFunction {
+    fn on_interrupt();
+}
+
+// Marker trait
+pub unsafe trait Registration<T: Interrupt> {}
+
+#[macro_export]
+macro_rules! register_interrupts {
+    ($name:ident: $($irq:ident),*) => {
+        struct $name;
+
+        $(
+            #[allow(non_snake_case)]
+            #[no_mangle]
+            extern "C" fn $irq() {
+                <$crate::interrupt::$irq as $crate::interrupt::InterruptFunction>::on_interrupt();
+            }
+
+            unsafe impl $crate::interrupt::Registration<$crate::interrupt::$irq> for $name {}
+        )*
+    };
+}

embassy-rp/src/uart/buffered.rs

@@ -1,339 +1,335 @@
 use core::future::{poll_fn, Future};
-use core::task::{Poll, Waker};
+use core::slice;
+use core::task::Poll;
 
-use atomic_polyfill::{compiler_fence, Ordering};
+use cortex_m::peripheral::NVIC;
-use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
+use embassy_hal_common::atomic_ring_buffer::RingBuffer;
-use embassy_hal_common::ring_buffer::RingBuffer;
+use embassy_sync::waitqueue::AtomicWaker;
-use embassy_sync::waitqueue::WakerRegistration;
 
 use super::*;
+use crate::interrupt::Registration;
 
-pub struct State<'d, T: Instance>(StateStorage<FullStateInner<'d, T>>);
+pub(crate) struct State {
-impl<'d, T: Instance> State<'d, T> {
+    tx_waker: AtomicWaker,
+    tx_buf: RingBuffer,
+    rx_waker: AtomicWaker,
+    rx_buf: RingBuffer,
+}
+
+impl State {
     pub const fn new() -> Self {
-        Self(StateStorage::new())
+        Self {
+            rx_buf: RingBuffer::new(),
+            tx_buf: RingBuffer::new(),
+            rx_waker: AtomicWaker::new(),
+            tx_waker: AtomicWaker::new(),
+        }
     }
 }
 
-pub struct RxState<'d, T: Instance>(StateStorage<RxStateInner<'d, T>>);
+pub struct BufferedUart<'d> {
-impl<'d, T: Instance> RxState<'d, T> {
+    info: &'static Info,
-    pub const fn new() -> Self {
+    phantom: PhantomData<&'d mut ()>,
-        Self(StateStorage::new())
-    }
 }
 
-pub struct TxState<'d, T: Instance>(StateStorage<TxStateInner<'d, T>>);
+pub struct BufferedUartRx<'d> {
-impl<'d, T: Instance> TxState<'d, T> {
+    info: &'static Info,
-    pub const fn new() -> Self {
+    phantom: PhantomData<&'d mut ()>,
-        Self(StateStorage::new())
-    }
 }
 
-struct RxStateInner<'d, T: Instance> {
+pub struct BufferedUartTx<'d> {
-    phantom: PhantomData<&'d mut T>,
+    info: &'static Info,
-
+    phantom: PhantomData<&'d mut ()>,
-    waker: WakerRegistration,
-    buf: RingBuffer<'d>,
 }
 
-struct TxStateInner<'d, T: Instance> {
+impl<'d> BufferedUart<'d> {
-    phantom: PhantomData<&'d mut T>,
+    pub fn new<T: Instance>(
-
+        _uart: impl Peripheral<P = T> + 'd,
-    waker: WakerRegistration,
+        _irq: impl Registration<T::Interrupt>,
-    buf: RingBuffer<'d>,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
-}
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
-
-struct FullStateInner<'d, T: Instance> {
-    rx: RxStateInner<'d, T>,
-    tx: TxStateInner<'d, T>,
-}
-
-unsafe impl<'d, T: Instance> Send for RxStateInner<'d, T> {}
-unsafe impl<'d, T: Instance> Sync for RxStateInner<'d, T> {}
-
-unsafe impl<'d, T: Instance> Send for TxStateInner<'d, T> {}
-unsafe impl<'d, T: Instance> Sync for TxStateInner<'d, T> {}
-
-unsafe impl<'d, T: Instance> Send for FullStateInner<'d, T> {}
-unsafe impl<'d, T: Instance> Sync for FullStateInner<'d, T> {}
-
-pub struct BufferedUart<'d, T: Instance> {
-    inner: PeripheralMutex<'d, FullStateInner<'d, T>>,
-}
-
-pub struct BufferedUartRx<'d, T: Instance> {
-    inner: PeripheralMutex<'d, RxStateInner<'d, T>>,
-}
-
-pub struct BufferedUartTx<'d, T: Instance> {
-    inner: PeripheralMutex<'d, TxStateInner<'d, T>>,
-}
-
-impl<'d, T: Instance> Unpin for BufferedUart<'d, T> {}
-impl<'d, T: Instance> Unpin for BufferedUartRx<'d, T> {}
-impl<'d, T: Instance> Unpin for BufferedUartTx<'d, T> {}
-
-impl<'d, T: Instance> BufferedUart<'d, T> {
-    pub fn new<M: Mode>(
-        state: &'d mut State<'d, T>,
-        _uart: Uart<'d, T, M>,
-        irq: impl Peripheral<P = T::Interrupt> + 'd,
         tx_buffer: &'d mut [u8],
         rx_buffer: &'d mut [u8],
-    ) -> BufferedUart<'d, T> {
+        config: Config,
-        into_ref!(irq);
+    ) -> Self {
+        into_ref!(tx, rx);
+        Self::new_inner(
+            T::info(),
+            tx.map_into(),
+            rx.map_into(),
+            None,
+            None,
+            tx_buffer,
+            rx_buffer,
+            config,
+        )
+    }
+
+    pub fn new_with_rtscts<T: Instance>(
+        _uart: impl Peripheral<P = T> + 'd,
+        _irq: impl Registration<T::Interrupt>,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
+        cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
+        tx_buffer: &'d mut [u8],
+        rx_buffer: &'d mut [u8],
+        config: Config,
+    ) -> Self {
+        into_ref!(tx, rx, cts, rts);
+        Self::new_inner(
+            T::info(),
+            tx.map_into(),
+            rx.map_into(),
+            Some(rts.map_into()),
+            Some(cts.map_into()),
+            tx_buffer,
+            rx_buffer,
+            config,
+        )
+    }
+
+    fn new_inner(
+        info: &'static Info,
+        mut tx: PeripheralRef<'d, AnyPin>,
+        mut rx: PeripheralRef<'d, AnyPin>,
+        mut rts: Option<PeripheralRef<'d, AnyPin>>,
+        mut cts: Option<PeripheralRef<'d, AnyPin>>,
+        tx_buffer: &'d mut [u8],
+        rx_buffer: &'d mut [u8],
+        config: Config,
+    ) -> Self {
+        init(
+            info,
+            Some(tx.reborrow()),
+            Some(rx.reborrow()),
+            rts.as_mut().map(|x| x.reborrow()),
+            cts.as_mut().map(|x| x.reborrow()),
+            config,
+        );
+
+        let len = tx_buffer.len();
+        unsafe { info.state.tx_buf.init(tx_buffer.as_mut_ptr(), len) };
+        let len = rx_buffer.len();
+        unsafe { info.state.rx_buf.init(rx_buffer.as_mut_ptr(), len) };
 
-        let r = T::regs();
         unsafe {
-            r.uartimsc().modify(|w| {
+            info.regs.uartimsc().modify(|w| {
                 w.set_rxim(true);
                 w.set_rtim(true);
                 w.set_txim(true);
             });
+
+            NVIC::unpend(info.irq);
+            NVIC::unmask(info.irq);
+            NVIC::pend(info.irq);
         }
 
         Self {
-            inner: PeripheralMutex::new(irq, &mut state.0, move || FullStateInner {
+            info,
-                tx: TxStateInner {
+            phantom: PhantomData,
-                    phantom: PhantomData,
-                    waker: WakerRegistration::new(),
-                    buf: RingBuffer::new(tx_buffer),
-                },
-                rx: RxStateInner {
-                    phantom: PhantomData,
-                    waker: WakerRegistration::new(),
-                    buf: RingBuffer::new(rx_buffer),
-                },
-            }),
         }
     }
 }
 
-impl<'d, T: Instance> BufferedUartRx<'d, T> {
+impl<'d> BufferedUartRx<'d> {
-    pub fn new<M: Mode>(
+    pub fn new<T: Instance>(
-        state: &'d mut RxState<'d, T>,
+        _uart: impl Peripheral<P = T> + 'd,
-        _uart: UartRx<'d, T, M>,
+        irq: impl Registration<T::Interrupt>,
-        irq: impl Peripheral<P = T::Interrupt> + 'd,
         rx_buffer: &'d mut [u8],
-    ) -> BufferedUartRx<'d, T> {
+        config: Config,
-        into_ref!(irq);
+    ) -> BufferedUartRx<'d> {
-
+        let info = T::info();
-        let r = T::regs();
         unsafe {
-            r.uartimsc().modify(|w| {
+            info.regs.uartimsc().modify(|w| {
                 w.set_rxim(true);
                 w.set_rtim(true);
             });
+
+            NVIC::unpend(info.irq);
+            NVIC::unmask(info.irq);
         }
 
         Self {
-            inner: PeripheralMutex::new(irq, &mut state.0, move || RxStateInner {
+            info,
-                phantom: PhantomData,
+            phantom: PhantomData,
-
-                buf: RingBuffer::new(rx_buffer),
-                waker: WakerRegistration::new(),
-            }),
         }
     }
 }
 
-impl<'d, T: Instance> BufferedUartTx<'d, T> {
+impl<'d> BufferedUartTx<'d> {
-    pub fn new<M: Mode>(
+    pub fn new<T: Instance>(
-        state: &'d mut TxState<'d, T>,
+        _uart: impl Peripheral<P = T> + 'd,
-        _uart: UartTx<'d, T, M>,
+        irq: impl Registration<T::Interrupt>,
-        irq: impl Peripheral<P = T::Interrupt> + 'd,
         tx_buffer: &'d mut [u8],
-    ) -> BufferedUartTx<'d, T> {
+        config: Config,
-        into_ref!(irq);
+    ) -> BufferedUartTx<'d> {
-
+        let info = T::info();
-        let r = T::regs();
         unsafe {
+            info.regs.uartimsc().modify(|w| {
+                w.set_txim(true);
+            });
+
+            NVIC::unpend(info.irq);
+            NVIC::unmask(info.irq);
+        }
+
+        Self {
+            info,
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<'d> Drop for BufferedUart<'d> {
+    fn drop(&mut self) {
+        NVIC::mask(self.info.irq);
+    }
+}
+
+impl<'d> Drop for BufferedUartRx<'d> {
+    fn drop(&mut self) {
+        NVIC::mask(self.info.irq);
+    }
+}
+
+impl<'d> Drop for BufferedUartTx<'d> {
+    fn drop(&mut self) {
+        NVIC::mask(self.info.irq);
+    }
+}
+
+pub(crate) fn on_interrupt(info: &'static Info) {
+    trace!("on_interrupt");
+
+    let r = info.regs;
+    let s = info.state;
+
+    unsafe {
+        // RX
+
+        let ris = r.uartris().read();
+        // Clear interrupt flags
+        r.uarticr().write(|w| {
+            w.set_rxic(true);
+            w.set_rtic(true);
+        });
+
+        if ris.peris() {
+            warn!("Parity error");
+            r.uarticr().write(|w| {
+                w.set_peic(true);
+            });
+        }
+        if ris.feris() {
+            warn!("Framing error");
+            r.uarticr().write(|w| {
+                w.set_feic(true);
+            });
+        }
+        if ris.beris() {
+            warn!("Break error");
+            r.uarticr().write(|w| {
+                w.set_beic(true);
+            });
+        }
+        if ris.oeris() {
+            warn!("Overrun error");
+            r.uarticr().write(|w| {
+                w.set_oeic(true);
+            });
+        }
+
+        let rx_writer = s.rx_buf.writer();
+        if !r.uartfr().read().rxfe() {
+            let val = r.uartdr().read().data();
+            if !rx_writer.push_one(val) {
+                warn!("RX buffer full, discard received byte");
+            }
+            s.rx_waker.wake();
+        }
+
+        // TX
+        let tx_reader = s.tx_buf.reader();
+        if let Some(val) = tx_reader.pop_one() {
             r.uartimsc().modify(|w| {
                 w.set_txim(true);
             });
-        }
+            r.uartdr().write(|w| w.set_data(val));
-
+            s.tx_waker.wake();
-        Self {
+        } else {
-            inner: PeripheralMutex::new(irq, &mut state.0, move || TxStateInner {
+            // Disable interrupt until we have something to transmit again
-                phantom: PhantomData,
+            r.uartimsc().modify(|w| {
-
+                w.set_txim(false);
-                buf: RingBuffer::new(tx_buffer),
-                waker: WakerRegistration::new(),
-            }),
-        }
-    }
-}
-
-impl<'d, T: Instance> PeripheralState for FullStateInner<'d, T>
-where
-    Self: 'd,
-{
-    type Interrupt = T::Interrupt;
-    fn on_interrupt(&mut self) {
-        self.rx.on_interrupt();
-        self.tx.on_interrupt();
-    }
-}
-
-impl<'d, T: Instance> RxStateInner<'d, T>
-where
-    Self: 'd,
-{
-    fn read(&mut self, buf: &mut [u8], waker: &Waker) -> (Poll<Result<usize, Error>>, bool) {
-        // We have data ready in buffer? Return it.
-        let mut do_pend = false;
-        let data = self.buf.pop_buf();
-        if !data.is_empty() {
-            let len = data.len().min(buf.len());
-            buf[..len].copy_from_slice(&data[..len]);
-
-            if self.buf.is_full() {
-                do_pend = true;
-            }
-            self.buf.pop(len);
-
-            return (Poll::Ready(Ok(len)), do_pend);
-        }
-
-        self.waker.register(waker);
-        (Poll::Pending, do_pend)
-    }
-
-    fn fill_buf<'a>(&mut self, waker: &Waker) -> Poll<Result<&'a [u8], Error>> {
-        // We have data ready in buffer? Return it.
-        let buf = self.buf.pop_buf();
-        if !buf.is_empty() {
-            let buf: &[u8] = buf;
-            // Safety: buffer lives as long as uart
-            let buf: &[u8] = unsafe { core::mem::transmute(buf) };
-            return Poll::Ready(Ok(buf));
-        }
-
-        self.waker.register(waker);
-        Poll::Pending
-    }
-
-    fn consume(&mut self, amt: usize) -> bool {
-        let full = self.buf.is_full();
-        self.buf.pop(amt);
-        full
-    }
-}
-
-impl<'d, T: Instance> PeripheralState for RxStateInner<'d, T>
-where
-    Self: 'd,
-{
-    type Interrupt = T::Interrupt;
-    fn on_interrupt(&mut self) {
-        let r = T::regs();
-        unsafe {
-            let ris = r.uartris().read();
-            // Clear interrupt flags
-            r.uarticr().modify(|w| {
-                w.set_rxic(true);
-                w.set_rtic(true);
             });
-
-            if ris.peris() {
-                warn!("Parity error");
-                r.uarticr().modify(|w| {
-                    w.set_peic(true);
-                });
-            }
-            if ris.feris() {
-                warn!("Framing error");
-                r.uarticr().modify(|w| {
-                    w.set_feic(true);
-                });
-            }
-            if ris.beris() {
-                warn!("Break error");
-                r.uarticr().modify(|w| {
-                    w.set_beic(true);
-                });
-            }
-            if ris.oeris() {
-                warn!("Overrun error");
-                r.uarticr().modify(|w| {
-                    w.set_oeic(true);
-                });
-            }
-
-            if !r.uartfr().read().rxfe() {
-                let buf = self.buf.push_buf();
-                if !buf.is_empty() {
-                    buf[0] = r.uartdr().read().data();
-                    self.buf.push(1);
-                } else {
-                    warn!("RX buffer full, discard received byte");
-                }
-
-                if self.buf.is_full() {
-                    self.waker.wake();
-                }
-            }
-
-            if ris.rtris() {
-                self.waker.wake();
-            };
         }
     }
 }
 
-impl<'d, T: Instance> TxStateInner<'d, T>
+fn read<'a>(info: &'static Info, buf: &'a mut [u8]) -> impl Future<Output = Result<usize, Error>> + 'a {
-where
+    poll_fn(move |cx| {
-    Self: 'd,
+        let rx_reader = unsafe { info.state.rx_buf.reader() };
-{
+        let n = rx_reader.pop(|data| {
-    fn write(&mut self, buf: &[u8], waker: &Waker) -> (Poll<Result<usize, Error>>, bool) {
+            let n = data.len().min(buf.len());
-        let empty = self.buf.is_empty();
+            buf[..n].copy_from_slice(&data[..n]);
-        let tx_buf = self.buf.push_buf();
+            n
-        if tx_buf.is_empty() {
+        });
-            self.waker.register(waker);
+        if n == 0 {
-            return (Poll::Pending, empty);
+            info.state.rx_waker.register(cx.waker());
+            return Poll::Pending;
         }
 
-        let n = core::cmp::min(tx_buf.len(), buf.len());
+        Poll::Ready(Ok(n))
-        tx_buf[..n].copy_from_slice(&buf[..n]);
+    })
-        self.buf.push(n);
+}
 
-        (Poll::Ready(Ok(n)), empty)
+fn fill_buf<'a>(info: &'static Info) -> impl Future<Output = Result<&'a [u8], Error>> {
-    }
+    poll_fn(move |cx| {
+        let rx_reader = unsafe { info.state.rx_buf.reader() };
+        let (p, n) = rx_reader.pop_buf();
+        if n == 0 {
+            info.state.rx_waker.register(cx.waker());
+            return Poll::Pending;
+        }
 
-    fn flush(&mut self, waker: &Waker) -> Poll<Result<(), Error>> {
+        let buf = unsafe { slice::from_raw_parts(p, n) };
-        if !self.buf.is_empty() {
+        Poll::Ready(Ok(buf))
-            self.waker.register(waker);
+    })
+}
+
+fn consume(info: &'static Info, amt: usize) {
+    let rx_reader = unsafe { info.state.rx_buf.reader() };
+    rx_reader.pop_done(amt)
+}
+
+fn write<'a>(info: &'static Info, buf: &'a [u8]) -> impl Future<Output = Result<usize, Error>> + 'a {
+    poll_fn(move |cx| {
+        let tx_writer = unsafe { info.state.tx_buf.writer() };
+        let n = tx_writer.push(|data| {
+            let n = data.len().min(buf.len());
+            data[..n].copy_from_slice(&buf[..n]);
+            n
+        });
+        if n == 0 {
+            info.state.tx_waker.register(cx.waker());
+            return Poll::Pending;
+        } else {
+            NVIC::pend(info.irq);
+        }
+
+        Poll::Ready(Ok(n))
+    })
+}
+
+fn flush(info: &'static Info) -> impl Future<Output = Result<(), Error>> {
+    poll_fn(move |cx| {
+        if !info.state.tx_buf.is_empty() {
+            info.state.tx_waker.register(cx.waker());
             return Poll::Pending;
         }
 
         Poll::Ready(Ok(()))
-    }
+    })
-}
-
-impl<'d, T: Instance> PeripheralState for TxStateInner<'d, T>
-where
-    Self: 'd,
-{
-    type Interrupt = T::Interrupt;
-    fn on_interrupt(&mut self) {
-        let r = T::regs();
-        unsafe {
-            let buf = self.buf.pop_buf();
-            if !buf.is_empty() {
-                r.uartimsc().modify(|w| {
-                    w.set_txim(true);
-                });
-                r.uartdr().write(|w| w.set_data(buf[0].into()));
-                self.buf.pop(1);
-                self.waker.wake();
-            } else {
-                // Disable interrupt until we have something to transmit again
-                r.uartimsc().modify(|w| {
-                    w.set_txim(false);
-                });
-            }
-        }
-    }
 }
 
 impl embedded_io::Error for Error {
@@ -342,117 +338,73 @@ impl embedded_io::Error for Error {
     }
 }
 
-impl<'d, T: Instance> embedded_io::Io for BufferedUart<'d, T> {
+impl<'d> embedded_io::Io for BufferedUart<'d> {
     type Error = Error;
 }
 
-impl<'d, T: Instance> embedded_io::Io for BufferedUartRx<'d, T> {
+impl<'d> embedded_io::Io for BufferedUartRx<'d> {
     type Error = Error;
 }
 
-impl<'d, T: Instance> embedded_io::Io for BufferedUartTx<'d, T> {
+impl<'d> embedded_io::Io for BufferedUartTx<'d> {
     type Error = Error;
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::Read for BufferedUart<'d, T> {
+impl<'d> embedded_io::asynch::Read for BufferedUart<'d> {
     type ReadFuture<'a> = impl Future<Output = Result<usize, Self::Error>> + 'a
     where
         Self: 'a;
 
     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        poll_fn(move |cx| {
+        read(self.info, buf)
-            let (res, do_pend) = self.inner.with(|state| {
-                compiler_fence(Ordering::SeqCst);
-                state.rx.read(buf, cx.waker())
-            });
-
-            if do_pend {
-                self.inner.pend();
-            }
-
-            res
-        })
     }
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::Read for BufferedUartRx<'d, T> {
+impl<'d> embedded_io::asynch::Read for BufferedUartRx<'d> {
     type ReadFuture<'a> = impl Future<Output = Result<usize, Self::Error>> + 'a
     where
         Self: 'a;
 
     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        poll_fn(move |cx| {
+        read(self.info, buf)
-            let (res, do_pend) = self.inner.with(|state| {
-                compiler_fence(Ordering::SeqCst);
-                state.read(buf, cx.waker())
-            });
-
-            if do_pend {
-                self.inner.pend();
-            }
-
-            res
-        })
     }
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for BufferedUart<'d, T> {
+impl<'d> embedded_io::asynch::BufRead for BufferedUart<'d> {
     type FillBufFuture<'a> = impl Future<Output = Result<&'a [u8], Self::Error>> + 'a
     where
         Self: 'a;
 
     fn fill_buf<'a>(&'a mut self) -> Self::FillBufFuture<'a> {
-        poll_fn(move |cx| {
+        fill_buf(self.info)
-            self.inner.with(|state| {
-                compiler_fence(Ordering::SeqCst);
-                state.rx.fill_buf(cx.waker())
-            })
-        })
     }
 
     fn consume(&mut self, amt: usize) {
-        let signal = self.inner.with(|state| state.rx.consume(amt));
+        consume(self.info, amt)
-        if signal {
-            self.inner.pend();
-        }
     }
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for BufferedUartRx<'d, T> {
+impl<'d> embedded_io::asynch::BufRead for BufferedUartRx<'d> {
     type FillBufFuture<'a> = impl Future<Output = Result<&'a [u8], Self::Error>> + 'a
     where
         Self: 'a;
 
     fn fill_buf<'a>(&'a mut self) -> Self::FillBufFuture<'a> {
-        poll_fn(move |cx| {
+        fill_buf(self.info)
-            self.inner.with(|state| {
-                compiler_fence(Ordering::SeqCst);
-                state.fill_buf(cx.waker())
-            })
-        })
     }
 
     fn consume(&mut self, amt: usize) {
-        let signal = self.inner.with(|state| state.consume(amt));
+        consume(self.info, amt)
-        if signal {
-            self.inner.pend();
-        }
     }
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUart<'d, T> {
+impl<'d> embedded_io::asynch::Write for BufferedUart<'d> {
     type WriteFuture<'a> = impl Future<Output = Result<usize, Self::Error>> + 'a
     where
         Self: 'a;
 
     fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
-        poll_fn(move |cx| {
+        write(self.info, buf)
-            let (poll, empty) = self.inner.with(|state| state.tx.write(buf, cx.waker()));
-            if empty {
-                self.inner.pend();
-            }
-            poll
-        })
     }
 
     type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a
@@ -460,23 +412,17 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUart<'d, T> {
         Self: 'a;
 
     fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
-        poll_fn(move |cx| self.inner.with(|state| state.tx.flush(cx.waker())))
+        flush(self.info)
     }
 }
 
-impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUartTx<'d, T> {
+impl<'d> embedded_io::asynch::Write for BufferedUartTx<'d> {
     type WriteFuture<'a> = impl Future<Output = Result<usize, Self::Error>> + 'a
     where
         Self: 'a;
 
     fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
-        poll_fn(move |cx| {
+        write(self.info, buf)
-            let (poll, empty) = self.inner.with(|state| state.write(buf, cx.waker()));
-            if empty {
-                self.inner.pend();
-            }
-            poll
-        })
     }
 
     type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a
@@ -484,6 +430,6 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUartTx<'d, T>
         Self: 'a;
 
     fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
-        poll_fn(move |cx| self.inner.with(|state| state.flush(cx.waker())))
+        flush(self.info)
     }
 }

embassy-rp/src/uart/mod.rs

@@ -5,7 +5,13 @@ use embassy_hal_common::{into_ref, PeripheralRef};
 use crate::dma::{AnyChannel, Channel};
 use crate::gpio::sealed::Pin;
 use crate::gpio::AnyPin;
-use crate::{pac, peripherals, Peripheral};
+use crate::pac::uart as pac;
+use crate::{peripherals, Peripheral};
+
+#[cfg(feature = "nightly")]
+mod buffered;
+#[cfg(feature = "nightly")]
+pub use buffered::*;
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum DataBits {
@@ -77,31 +83,26 @@ pub enum Error {
     Framing,
 }
 
-pub struct Uart<'d, T: Instance, M: Mode> {
+pub struct Uart<'d, M: Mode> {
-    tx: UartTx<'d, T, M>,
+    tx: UartTx<'d, M>,
-    rx: UartRx<'d, T, M>,
+    rx: UartRx<'d, M>,
 }
 
-pub struct UartTx<'d, T: Instance, M: Mode> {
+pub struct UartTx<'d, M: Mode> {
+    info: &'static Info,
     tx_dma: Option<PeripheralRef<'d, AnyChannel>>,
-    phantom: PhantomData<(&'d mut T, M)>,
+    phantom: PhantomData<M>,
 }
 
-pub struct UartRx<'d, T: Instance, M: Mode> {
+pub struct UartRx<'d, M: Mode> {
+    info: &'static Info,
     rx_dma: Option<PeripheralRef<'d, AnyChannel>>,
-    phantom: PhantomData<(&'d mut T, M)>,
+    phantom: PhantomData<M>,
 }
 
-impl<'d, T: Instance, M: Mode> UartTx<'d, T, M> {
+impl<'d, M: Mode> UartTx<'d, M> {
-    fn new(tx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
-        Self {
-            tx_dma,
-            phantom: PhantomData,
-        }
-    }
-
     pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
-        let r = T::regs();
+        let r = self.info.regs;
         unsafe {
             for &b in buffer {
                 while r.uartfr().read().txff() {}
@@ -112,38 +113,31 @@ impl<'d, T: Instance, M: Mode> UartTx<'d, T, M> {
     }
 
     pub fn blocking_flush(&mut self) -> Result<(), Error> {
-        let r = T::regs();
+        let r = self.info.regs;
         unsafe { while !r.uartfr().read().txfe() {} }
         Ok(())
     }
 }
 
-impl<'d, T: Instance> UartTx<'d, T, Async> {
+impl<'d> UartTx<'d, Async> {
     pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
         let ch = self.tx_dma.as_mut().unwrap();
         let transfer = unsafe {
-            T::regs().uartdmacr().modify(|reg| {
+            self.info.regs.uartdmacr().modify(|reg| {
                 reg.set_txdmae(true);
             });
             // If we don't assign future to a variable, the data register pointer
             // is held across an await and makes the future non-Send.
-            crate::dma::write(ch, buffer, T::regs().uartdr().ptr() as *mut _, T::TX_DREQ)
+            crate::dma::write(ch, buffer, self.info.regs.uartdr().ptr() as *mut _, self.info.tx_dreq)
         };
         transfer.await;
         Ok(())
     }
 }
 
-impl<'d, T: Instance, M: Mode> UartRx<'d, T, M> {
+impl<'d, M: Mode> UartRx<'d, M> {
-    fn new(rx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
-        Self {
-            rx_dma,
-            phantom: PhantomData,
-        }
-    }
-
     pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
-        let r = T::regs();
+        let r = self.info.regs;
         unsafe {
             for b in buffer {
                 *b = loop {
@@ -171,37 +165,37 @@ impl<'d, T: Instance, M: Mode> UartRx<'d, T, M> {
     }
 }
 
-impl<'d, T: Instance> UartRx<'d, T, Async> {
+impl<'d> UartRx<'d, Async> {
     pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
         let ch = self.rx_dma.as_mut().unwrap();
         let transfer = unsafe {
-            T::regs().uartdmacr().modify(|reg| {
+            self.info.regs.uartdmacr().modify(|reg| {
                 reg.set_rxdmae(true);
             });
             // If we don't assign future to a variable, the data register pointer
             // is held across an await and makes the future non-Send.
-            crate::dma::read(ch, T::regs().uartdr().ptr() as *const _, buffer, T::RX_DREQ)
+            crate::dma::read(ch, self.info.regs.uartdr().ptr() as *const _, buffer, self.info.rx_dreq)
         };
         transfer.await;
         Ok(())
     }
 }
 
-impl<'d, T: Instance> Uart<'d, T, Blocking> {
+impl<'d> Uart<'d, Blocking> {
     /// Create a new UART without hardware flow control
-    pub fn new_blocking(
+    pub fn new_blocking<T: Instance>(
-        uart: impl Peripheral<P = T> + 'd,
+        _uart: impl Peripheral<P = T> + 'd,
         tx: impl Peripheral<P = impl TxPin<T>> + 'd,
         rx: impl Peripheral<P = impl RxPin<T>> + 'd,
         config: Config,
     ) -> Self {
         into_ref!(tx, rx);
-        Self::new_inner(uart, rx.map_into(), tx.map_into(), None, None, None, None, config)
+        Self::new_inner(T::info(), tx.map_into(), rx.map_into(), None, None, None, None, config)
     }
 
     /// Create a new UART with hardware flow control (RTS/CTS)
-    pub fn new_with_rtscts_blocking(
+    pub fn new_with_rtscts_blocking<T: Instance>(
-        uart: impl Peripheral<P = T> + 'd,
+        _uart: impl Peripheral<P = T> + 'd,
         tx: impl Peripheral<P = impl TxPin<T>> + 'd,
         rx: impl Peripheral<P = impl RxPin<T>> + 'd,
         rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
@@ -210,9 +204,9 @@ impl<'d, T: Instance> Uart<'d, T, Blocking> {
     ) -> Self {
         into_ref!(tx, rx, cts, rts);
         Self::new_inner(
-            uart,
+            T::info(),
-            rx.map_into(),
             tx.map_into(),
+            rx.map_into(),
             Some(rts.map_into()),
             Some(cts.map_into()),
             None,
@@ -222,10 +216,10 @@ impl<'d, T: Instance> Uart<'d, T, Blocking> {
     }
 }
 
-impl<'d, T: Instance> Uart<'d, T, Async> {
+impl<'d> Uart<'d, Async> {
     /// Create a new DMA enabled UART without hardware flow control
-    pub fn new(
+    pub fn new<T: Instance>(
-        uart: impl Peripheral<P = T> + 'd,
+        _uart: impl Peripheral<P = T> + 'd,
         tx: impl Peripheral<P = impl TxPin<T>> + 'd,
         rx: impl Peripheral<P = impl RxPin<T>> + 'd,
         tx_dma: impl Peripheral<P = impl Channel> + 'd,
@@ -234,9 +228,9 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
     ) -> Self {
         into_ref!(tx, rx, tx_dma, rx_dma);
         Self::new_inner(
-            uart,
+            T::info(),
-            rx.map_into(),
             tx.map_into(),
+            rx.map_into(),
             None,
             None,
             Some(tx_dma.map_into()),
@@ -246,8 +240,8 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
     }
 
     /// Create a new DMA enabled UART with hardware flow control (RTS/CTS)
-    pub fn new_with_rtscts(
+    pub fn new_with_rtscts<T: Instance>(
-        uart: impl Peripheral<P = T> + 'd,
+        _uart: impl Peripheral<P = T> + 'd,
         tx: impl Peripheral<P = impl TxPin<T>> + 'd,
         rx: impl Peripheral<P = impl RxPin<T>> + 'd,
         rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
@@ -258,7 +252,7 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
     ) -> Self {
         into_ref!(tx, rx, cts, rts, tx_dma, rx_dma);
         Self::new_inner(
-            uart,
+            T::info(),
             rx.map_into(),
             tx.map_into(),
             Some(rts.map_into()),
@@ -270,104 +264,120 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
     }
 }
 
-impl<'d, T: Instance, M: Mode> Uart<'d, T, M> {
+impl<'d, M: Mode> Uart<'d, M> {
     fn new_inner(
-        _uart: impl Peripheral<P = T> + 'd,
+        info: &'static Info,
-        tx: PeripheralRef<'d, AnyPin>,
+        mut tx: PeripheralRef<'d, AnyPin>,
-        rx: PeripheralRef<'d, AnyPin>,
+        mut rx: PeripheralRef<'d, AnyPin>,
-        rts: Option<PeripheralRef<'d, AnyPin>>,
+        mut rts: Option<PeripheralRef<'d, AnyPin>>,
-        cts: Option<PeripheralRef<'d, AnyPin>>,
+        mut cts: Option<PeripheralRef<'d, AnyPin>>,
         tx_dma: Option<PeripheralRef<'d, AnyChannel>>,
         rx_dma: Option<PeripheralRef<'d, AnyChannel>>,
         config: Config,
     ) -> Self {
-        into_ref!(_uart);
+        init(
-
+            info,
-        unsafe {
+            Some(tx.reborrow()),
-            let r = T::regs();
+            Some(rx.reborrow()),
-
+            rts.as_mut().map(|x| x.reborrow()),
-            tx.io().ctrl().write(|w| w.set_funcsel(2));
+            cts.as_mut().map(|x| x.reborrow()),
-            rx.io().ctrl().write(|w| w.set_funcsel(2));
+            config,
-
+        );
-            tx.pad_ctrl().write(|w| {
-                w.set_ie(true);
-            });
-
-            rx.pad_ctrl().write(|w| {
-                w.set_ie(true);
-            });
-
-            if let Some(pin) = &cts {
-                pin.io().ctrl().write(|w| w.set_funcsel(2));
-                pin.pad_ctrl().write(|w| {
-                    w.set_ie(true);
-                });
-            }
-            if let Some(pin) = &rts {
-                pin.io().ctrl().write(|w| w.set_funcsel(2));
-                pin.pad_ctrl().write(|w| {
-                    w.set_ie(true);
-                });
-            }
-
-            let clk_base = crate::clocks::clk_peri_freq();
-
-            let baud_rate_div = (8 * clk_base) / config.baudrate;
-            let mut baud_ibrd = baud_rate_div >> 7;
-            let mut baud_fbrd = ((baud_rate_div & 0x7f) + 1) / 2;
-
-            if baud_ibrd == 0 {
-                baud_ibrd = 1;
-                baud_fbrd = 0;
-            } else if baud_ibrd >= 65535 {
-                baud_ibrd = 65535;
-                baud_fbrd = 0;
-            }
-
-            // Load PL011's baud divisor registers
-            r.uartibrd().write_value(pac::uart::regs::Uartibrd(baud_ibrd));
-            r.uartfbrd().write_value(pac::uart::regs::Uartfbrd(baud_fbrd));
-
-            let (pen, eps) = match config.parity {
-                Parity::ParityNone => (false, false),
-                Parity::ParityOdd => (true, false),
-                Parity::ParityEven => (true, true),
-            };
-
-            // PL011 needs a (dummy) line control register write to latch in the
-            // divisors. We don't want to actually change LCR contents here.
-            r.uartlcr_h().modify(|_| {});
-
-            r.uartlcr_h().write(|w| {
-                w.set_wlen(config.data_bits.bits());
-                w.set_stp2(config.stop_bits == StopBits::STOP2);
-                w.set_pen(pen);
-                w.set_eps(eps);
-                w.set_fen(true);
-            });
-
-            r.uartifls().write(|w| {
-                w.set_rxiflsel(0b000);
-                w.set_txiflsel(0b000);
-            });
-
-            r.uartcr().write(|w| {
-                w.set_uarten(true);
-                w.set_rxe(true);
-                w.set_txe(true);
-                w.set_ctsen(cts.is_some());
-                w.set_rtsen(rts.is_some());
-            });
-        }
 
         Self {
-            tx: UartTx::new(tx_dma),
+            tx: UartTx {
-            rx: UartRx::new(rx_dma),
+                info,
+                tx_dma,
+                phantom: PhantomData,
+            },
+            rx: UartRx {
+                info,
+                rx_dma,
+                phantom: PhantomData,
+            },
         }
     }
 }
 
-impl<'d, T: Instance, M: Mode> Uart<'d, T, M> {
+fn init(
+    info: &'static Info,
+    tx: Option<PeripheralRef<'_, AnyPin>>,
+    rx: Option<PeripheralRef<'_, AnyPin>>,
+    rts: Option<PeripheralRef<'_, AnyPin>>,
+    cts: Option<PeripheralRef<'_, AnyPin>>,
+    config: Config,
+) {
+    let r = info.regs;
+    unsafe {
+        if let Some(pin) = &tx {
+            pin.io().ctrl().write(|w| w.set_funcsel(2));
+            pin.pad_ctrl().write(|w| w.set_ie(true));
+        }
+        if let Some(pin) = &rx {
+            pin.io().ctrl().write(|w| w.set_funcsel(2));
+            pin.pad_ctrl().write(|w| w.set_ie(true));
+        }
+        if let Some(pin) = &cts {
+            pin.io().ctrl().write(|w| w.set_funcsel(2));
+            pin.pad_ctrl().write(|w| w.set_ie(true));
+        }
+        if let Some(pin) = &rts {
+            pin.io().ctrl().write(|w| w.set_funcsel(2));
+            pin.pad_ctrl().write(|w| w.set_ie(true));
+        }
+
+        let clk_base = crate::clocks::clk_peri_freq();
+
+        let baud_rate_div = (8 * clk_base) / config.baudrate;
+        let mut baud_ibrd = baud_rate_div >> 7;
+        let mut baud_fbrd = ((baud_rate_div & 0x7f) + 1) / 2;
+
+        if baud_ibrd == 0 {
+            baud_ibrd = 1;
+            baud_fbrd = 0;
+        } else if baud_ibrd >= 65535 {
+            baud_ibrd = 65535;
+            baud_fbrd = 0;
+        }
+
+        // Load PL011's baud divisor registers
+        r.uartibrd().write_value(pac::regs::Uartibrd(baud_ibrd));
+        r.uartfbrd().write_value(pac::regs::Uartfbrd(baud_fbrd));
+
+        let (pen, eps) = match config.parity {
+            Parity::ParityNone => (false, false),
+            Parity::ParityOdd => (true, false),
+            Parity::ParityEven => (true, true),
+        };
+
+        // PL011 needs a (dummy) line control register write to latch in the
+        // divisors. We don't want to actually change LCR contents here.
+        r.uartlcr_h().modify(|_| {});
+
+        r.uartlcr_h().write(|w| {
+            w.set_wlen(config.data_bits.bits());
+            w.set_stp2(config.stop_bits == StopBits::STOP2);
+            w.set_pen(pen);
+            w.set_eps(eps);
+            w.set_fen(true);
+        });
+
+        r.uartifls().write(|w| {
+            w.set_rxiflsel(0b000);
+            w.set_txiflsel(0b000);
+        });
+
+        r.uartcr().write(|w| {
+            w.set_uarten(true);
+            w.set_rxe(true);
+            w.set_txe(true);
+            w.set_ctsen(cts.is_some());
+            w.set_rtsen(rts.is_some());
+        });
+    }
+}
+
+impl<'d, M: Mode> Uart<'d, M> {
     pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
         self.tx.blocking_write(buffer)
     }
@@ -382,12 +392,12 @@ impl<'d, T: Instance, M: Mode> Uart<'d, T, M> {
 
     /// Split the Uart into a transmitter and receiver, which is particuarly
     /// useful when having two tasks correlating to transmitting and receiving.
-    pub fn split(self) -> (UartTx<'d, T, M>, UartRx<'d, T, M>) {
+    pub fn split(self) -> (UartTx<'d, M>, UartRx<'d, M>) {
         (self.tx, self.rx)
     }
 }
 
-impl<'d, T: Instance> Uart<'d, T, Async> {
+impl<'d> Uart<'d, Async> {
     pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
         self.tx.write(buffer).await
     }
@@ -400,10 +410,10 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
 mod eh02 {
     use super::*;
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_02::serial::Read<u8> for UartRx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_02::serial::Read<u8> for UartRx<'d, M> {
         type Error = Error;
         fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
-            let r = T::regs();
+            let r = self.info.regs;
             unsafe {
                 if r.uartfr().read().rxfe() {
                     return Err(nb::Error::WouldBlock);
@@ -426,7 +436,7 @@ mod eh02 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::serial::Write<u8> for UartTx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_02::blocking::serial::Write<u8> for UartTx<'d, M> {
         type Error = Error;
 
         fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
@@ -438,7 +448,7 @@ mod eh02 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_02::serial::Read<u8> for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_02::serial::Read<u8> for Uart<'d, M> {
         type Error = Error;
 
         fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
@@ -446,7 +456,7 @@ mod eh02 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::serial::Write<u8> for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_02::blocking::serial::Write<u8> for Uart<'d, M> {
         type Error = Error;
 
         fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
@@ -474,21 +484,21 @@ mod eh1 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_1::serial::ErrorType for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_1::serial::ErrorType for Uart<'d, M> {
         type Error = Error;
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_1::serial::ErrorType for UartTx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_1::serial::ErrorType for UartTx<'d, M> {
         type Error = Error;
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_1::serial::ErrorType for UartRx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_1::serial::ErrorType for UartRx<'d, M> {
         type Error = Error;
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_nb::serial::Read for UartRx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_nb::serial::Read for UartRx<'d, M> {
         fn read(&mut self) -> nb::Result<u8, Self::Error> {
-            let r = T::regs();
+            let r = self.info.regs;
             unsafe {
                 let dr = r.uartdr().read();
 
@@ -509,7 +519,7 @@ mod eh1 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_1::serial::Write for UartTx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_1::serial::Write for UartTx<'d, M> {
         fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
             self.blocking_write(buffer)
         }
@@ -519,7 +529,7 @@ mod eh1 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_nb::serial::Write for UartTx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_nb::serial::Write for UartTx<'d, M> {
         fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> {
             self.blocking_write(&[char]).map_err(nb::Error::Other)
         }
@@ -529,13 +539,13 @@ mod eh1 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_nb::serial::Read for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_nb::serial::Read for Uart<'d, M> {
         fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
             embedded_hal_02::serial::Read::read(&mut self.rx)
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_1::serial::Write for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_1::serial::Write for Uart<'d, M> {
         fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
             self.blocking_write(buffer)
         }
@@ -545,7 +555,7 @@ mod eh1 {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_nb::serial::Write for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_nb::serial::Write for Uart<'d, M> {
         fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> {
             self.blocking_write(&[char]).map_err(nb::Error::Other)
         }
@@ -566,7 +576,7 @@ mod eha {
 
     use super::*;
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_async::serial::Write for UartTx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_async::serial::Write for UartTx<'d, M> {
         type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
 
         fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
@@ -580,7 +590,7 @@ mod eha {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_async::serial::Read for UartRx<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_async::serial::Read for UartRx<'d, M> {
         type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
 
         fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
@@ -588,7 +598,7 @@ mod eha {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_async::serial::Write for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_async::serial::Write for Uart<'d, M> {
         type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
 
         fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
@@ -602,7 +612,7 @@ mod eha {
         }
     }
 
-    impl<'d, T: Instance, M: Mode> embedded_hal_async::serial::Read for Uart<'d, T, M> {
+    impl<'d, M: Mode> embedded_hal_async::serial::Read for Uart<'d, M> {
         type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
 
         fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
@@ -611,30 +621,32 @@ mod eha {
     }
 }
 
-#[cfg(feature = "nightly")]
-mod buffered;
-#[cfg(feature = "nightly")]
-pub use buffered::*;
-
 mod sealed {
     use super::*;
 
     pub trait Mode {}
 
     pub trait Instance {
-        const TX_DREQ: u8;
-        const RX_DREQ: u8;
-
         type Interrupt: crate::interrupt::Interrupt;
-
+        fn info() -> &'static Info;
-        fn regs() -> pac::uart::Uart;
     }
     pub trait TxPin<T: Instance> {}
     pub trait RxPin<T: Instance> {}
     pub trait CtsPin<T: Instance> {}
     pub trait RtsPin<T: Instance> {}
+
+    /// Info about one concrete peripheral instance.
+    pub struct Info {
+        pub(crate) regs: pac::Uart,
+        pub(crate) tx_dreq: u8,
+        pub(crate) rx_dreq: u8,
+        pub(crate) irq: crate::pac::Interrupt,
+        pub(crate) state: &'static super::buffered::State,
+    }
 }
 
+use sealed::Info;
+
 pub trait Mode: sealed::Mode {}
 
 macro_rules! impl_mode {
@@ -655,16 +667,27 @@ pub trait Instance: sealed::Instance {}
 macro_rules! impl_instance {
     ($inst:ident, $irq:ident, $tx_dreq:expr, $rx_dreq:expr) => {
         impl sealed::Instance for peripherals::$inst {
-            const TX_DREQ: u8 = $tx_dreq;
-            const RX_DREQ: u8 = $rx_dreq;
-
             type Interrupt = crate::interrupt::$irq;
 
-            fn regs() -> pac::uart::Uart {
+            fn info() -> &'static Info {
-                pac::$inst
+                static STATE: buffered::State = buffered::State::new();
+                static INFO: Info = Info {
+                    regs: crate::pac::$inst,
+                    tx_dreq: $tx_dreq,
+                    rx_dreq: $rx_dreq,
+                    irq: crate::pac::Interrupt::$irq,
+                    state: &STATE,
+                };
+                &INFO
             }
         }
         impl Instance for peripherals::$inst {}
+
+        impl crate::interrupt::InterruptFunction for crate::interrupt::$irq {
+            fn on_interrupt() {
+                buffered::on_interrupt(<peripherals::$inst as sealed::Instance>::info())
+            }
+        }
     };
 }
 

examples/rp/src/bin/uart.rs

@@ -3,9 +3,11 @@
 #![feature(type_alias_impl_trait)]
 
 use embassy_executor::Spawner;
-use embassy_rp::uart;
+use embassy_rp::{register_interrupts, uart};
 use {defmt_rtt as _, panic_probe as _};
 
+register_interrupts!(Reg: UART0_IRQ);
+
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
     let p = embassy_rp::init(Default::default());

tests/rp/src/bin/uart_buffered.rs

@@ -4,11 +4,13 @@
 
 use defmt::{assert_eq, *};
 use embassy_executor::Spawner;
-use embassy_rp::interrupt;
+use embassy_rp::register_interrupts;
-use embassy_rp::uart::{BufferedUart, Config, State, Uart};
+use embassy_rp::uart::{BufferedUart, Config};
 use embedded_io::asynch::{Read, Write};
 use {defmt_rtt as _, panic_probe as _};
 
+register_interrupts!(Irqs: UART0_IRQ);
+
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
     let p = embassy_rp::init(Default::default());
@@ -16,26 +18,26 @@ async fn main(_spawner: Spawner) {
 
     let (tx, rx, uart) = (p.PIN_0, p.PIN_1, p.UART0);
 
-    let config = Config::default();
-    let uart = Uart::new_blocking(uart, tx, rx, config);
-
-    let irq = interrupt::take!(UART0_IRQ);
     let tx_buf = &mut [0u8; 16];
     let rx_buf = &mut [0u8; 16];
-    let mut state = State::new();
+    let config = Config::default();
-    let mut uart = BufferedUart::new(&mut state, uart, irq, tx_buf, rx_buf);
+    let mut uart = BufferedUart::new(uart, Irqs, tx, rx, tx_buf, rx_buf, config);
 
     // Make sure we send more bytes than fits in the FIFO, to test the actual
     // bufferedUart.
 
     let data = [
         1_u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
-        30, 31, 32,
+        30, 31,
+    ];
+    let data = [
+        1u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+        30, 31,
     ];
     uart.write_all(&data).await.unwrap();
     info!("Done writing");
 
-    let mut buf = [0; 32];
+    let mut buf = [0; 31];
     uart.read_exact(&mut buf).await.unwrap();
     assert_eq!(buf, data);