Remove code-duplication in async bufferedUart implementations

embassy-rp/src/uart/buffered.rs

@@ -1,5 +1,5 @@
 use core::future::Future;
-use core::task::Poll;
+use core::task::{Poll, Waker};
 
 use atomic_polyfill::{compiler_fence, Ordering};
 use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
@@ -87,9 +87,9 @@ impl<'d, T: Instance> BufferedUart<'d, T> {
         let r = T::regs();
         unsafe {
             r.uartimsc().modify(|w| {
-                // TODO: Should and more or fewer interrupts be enabled?
                 w.set_rxim(true);
                 w.set_rtim(true);
+                w.set_txim(true);
             });
         }
 
@@ -122,7 +122,6 @@ impl<'d, T: Instance> RxBufferedUart<'d, T> {
         let r = T::regs();
         unsafe {
             r.uartimsc().modify(|w| {
-                // TODO: Should and more or fewer interrupts be enabled?
                 w.set_rxim(true);
                 w.set_rtim(true);
             });
@@ -151,9 +150,7 @@ impl<'d, T: Instance> TxBufferedUart<'d, T> {
         let r = T::regs();
         unsafe {
             r.uartimsc().modify(|w| {
-                // TODO: Should and more or fewer interrupts be enabled?
+                w.set_txim(true);
-                w.set_rxim(true);
-                w.set_rtim(true);
             });
         }
 
@@ -179,6 +176,51 @@ where
     }
 }
 
+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,
@@ -240,6 +282,35 @@ where
     }
 }
 
+impl<'d, T: Instance> TxStateInner<'d, T>
+where
+    Self: 'd,
+{
+    fn write(&mut self, buf: &[u8], waker: &Waker) -> (Poll<Result<usize, Error>>, bool) {
+        let empty = self.buf.is_empty();
+        let tx_buf = self.buf.push_buf();
+        if tx_buf.is_empty() {
+            self.waker.register(waker);
+            return (Poll::Pending, empty);
+        }
+
+        let n = core::cmp::min(tx_buf.len(), buf.len());
+        tx_buf[..n].copy_from_slice(&buf[..n]);
+        self.buf.push(n);
+
+        (Poll::Ready(Ok(n)), empty)
+    }
+
+    fn flush(&mut self, waker: &Waker) -> Poll<Result<(), Error>> {
+        if !self.buf.is_empty() {
+            self.waker.register(waker);
+            return Poll::Pending;
+        }
+
+        Poll::Ready(Ok(()))
+    }
+}
+
 impl<'d, T: Instance> PeripheralState for TxStateInner<'d, T>
 where
     Self: 'd,
@@ -299,26 +370,9 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Read for BufferedUart<'d, T> {
 
     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
         poll_fn(move |cx| {
-            let mut do_pend = false;
+            let (res, do_pend) = self.inner.with(|state| {
-            let res = self.inner.with(|state| {
                 compiler_fence(Ordering::SeqCst);
-
+                state.rx.read(buf, cx.waker())
-                // We have data ready in buffer? Return it.
-                let data = state.rx.buf.pop_buf();
-                if !data.is_empty() {
-                    let len = data.len().min(buf.len());
-                    buf[..len].copy_from_slice(&data[..len]);
-
-                    if state.rx.buf.is_full() {
-                        do_pend = true;
-                    }
-                    state.rx.buf.pop(len);
-
-                    return Poll::Ready(Ok(len));
-                }
-
-                state.rx.waker.register(cx.waker());
-                Poll::Pending
             });
 
             if do_pend {
@@ -337,26 +391,9 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Read for RxBufferedUart<'d, T> {
 
     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
         poll_fn(move |cx| {
-            let mut do_pend = false;
+            let (res, do_pend) = self.inner.with(|state| {
-            let res = self.inner.with(|state| {
                 compiler_fence(Ordering::SeqCst);
-
+                state.read(buf, cx.waker())
-                // We have data ready in buffer? Return it.
-                let data = state.buf.pop_buf();
-                if !data.is_empty() {
-                    let len = data.len().min(buf.len());
-                    buf[..len].copy_from_slice(&data[..len]);
-
-                    if state.buf.is_full() {
-                        do_pend = true;
-                    }
-                    state.buf.pop(len);
-
-                    return Poll::Ready(Ok(len));
-                }
-
-                state.waker.register(cx.waker());
-                Poll::Pending
             });
 
             if do_pend {
@@ -377,28 +414,13 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for BufferedUart<'d, T>
         poll_fn(move |cx| {
             self.inner.with(|state| {
                 compiler_fence(Ordering::SeqCst);
-
+                state.rx.fill_buf(cx.waker())
-                // We have data ready in buffer? Return it.
-                let buf = state.rx.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));
-                }
-
-                state.rx.waker.register(cx.waker());
-                Poll::<Result<&[u8], Self::Error>>::Pending
             })
         })
     }
 
     fn consume(&mut self, amt: usize) {
-        let signal = self.inner.with(|state| {
+        let signal = self.inner.with(|state| state.rx.consume(amt));
-            let full = state.rx.buf.is_full();
-            state.rx.buf.pop(amt);
-            full
-        });
         if signal {
             self.inner.pend();
         }
@@ -414,28 +436,13 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for RxBufferedUart<'d, T
         poll_fn(move |cx| {
             self.inner.with(|state| {
                 compiler_fence(Ordering::SeqCst);
-
+                state.fill_buf(cx.waker())
-                // We have data ready in buffer? Return it.
-                let buf = state.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));
-                }
-
-                state.waker.register(cx.waker());
-                Poll::<Result<&[u8], Self::Error>>::Pending
             })
         })
     }
 
     fn consume(&mut self, amt: usize) {
-        let signal = self.inner.with(|state| {
+        let signal = self.inner.with(|state| state.consume(amt));
-            let full = state.buf.is_full();
-            state.buf.pop(amt);
-            full
-        });
         if signal {
             self.inner.pend();
         }
@@ -449,20 +456,7 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUart<'d, T> {
 
     fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
         poll_fn(move |cx| {
-            let (poll, empty) = self.inner.with(|state| {
+            let (poll, empty) = self.inner.with(|state| state.tx.write(buf, cx.waker()));
-                let empty = state.tx.buf.is_empty();
-                let tx_buf = state.tx.buf.push_buf();
-                if tx_buf.is_empty() {
-                    state.tx.waker.register(cx.waker());
-                    return (Poll::Pending, empty);
-                }
-
-                let n = core::cmp::min(tx_buf.len(), buf.len());
-                tx_buf[..n].copy_from_slice(&buf[..n]);
-                state.tx.buf.push(n);
-
-                (Poll::Ready(Ok(n)), empty)
-            });
             if empty {
                 self.inner.pend();
             }
@@ -475,16 +469,7 @@ 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| {
+        poll_fn(move |cx| self.inner.with(|state| state.tx.flush(cx.waker())))
-            self.inner.with(|state| {
-                if !state.tx.buf.is_empty() {
-                    state.tx.waker.register(cx.waker());
-                    return Poll::Pending;
-                }
-
-                Poll::Ready(Ok(()))
-            })
-        })
     }
 }
 
@@ -495,20 +480,7 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Write for TxBufferedUart<'d, T>
 
     fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
         poll_fn(move |cx| {
-            let (poll, empty) = self.inner.with(|state| {
+            let (poll, empty) = self.inner.with(|state| state.write(buf, cx.waker()));
-                let empty = state.buf.is_empty();
-                let tx_buf = state.buf.push_buf();
-                if tx_buf.is_empty() {
-                    state.waker.register(cx.waker());
-                    return (Poll::Pending, empty);
-                }
-
-                let n = core::cmp::min(tx_buf.len(), buf.len());
-                tx_buf[..n].copy_from_slice(&buf[..n]);
-                state.buf.push(n);
-
-                (Poll::Ready(Ok(n)), empty)
-            });
             if empty {
                 self.inner.pend();
             }
@@ -521,15 +493,6 @@ impl<'d, T: Instance + 'd> embedded_io::asynch::Write for TxBufferedUart<'d, T>
         Self: 'a;
 
     fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
-        poll_fn(move |cx| {
+        poll_fn(move |cx| self.inner.with(|state| state.flush(cx.waker())))
-            self.inner.with(|state| {
-                if !state.buf.is_empty() {
-                    state.waker.register(cx.waker());
-                    return Poll::Pending;
-                }
-
-                Poll::Ready(Ok(()))
-            })
-        })
     }
 }