936: Add split() method to BufferedUarte in embassy-nrf r=ZoeyR a=ZoeyR

I haven't completed testing this yet. I'm creating this PR early so that I can get corrected if I went way off course.

This PR adds a `split()` method to `BufferedUarte` as discussed on matrix.

Co-authored-by: Zoey Riordan <zoey@dos.cafe>
This commit is contained in:
bors[bot] 2022-08-31 10:20:40 +00:00 committed by GitHub
commit 838f3065ea
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@ -13,6 +13,7 @@
//!
//! Please also see [crate::uarte] to understand when [BufferedUarte] should be used.
use core::cell::RefCell;
use core::cmp::min;
use core::future::Future;
use core::sync::atomic::{compiler_fence, Ordering};
@ -71,7 +72,7 @@ struct StateInner<'d, U: UarteInstance, T: TimerInstance> {
/// Interface to a UARTE instance
pub struct BufferedUarte<'d, U: UarteInstance, T: TimerInstance> {
inner: PeripheralMutex<'d, StateInner<'d, U, T>>,
inner: RefCell<PeripheralMutex<'d, StateInner<'d, U, T>>>,
}
impl<'d, U: UarteInstance, T: TimerInstance> Unpin for BufferedUarte<'d, U, T> {}
@ -169,7 +170,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
ppi_ch2.enable();
Self {
inner: PeripheralMutex::new(irq, &mut state.0, move || StateInner {
inner: RefCell::new(PeripheralMutex::new(irq, &mut state.0, move || StateInner {
_peri: peri,
timer,
_ppi_ch1: ppi_ch1,
@ -182,13 +183,13 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
tx: RingBuffer::new(tx_buffer),
tx_state: TxState::Idle,
tx_waker: WakerRegistration::new(),
}),
})),
}
}
/// Adjust the baud rate to the provided value.
pub fn set_baudrate(&mut self, baudrate: Baudrate) {
self.inner.with(|state| {
self.inner.borrow_mut().with(|state| {
let r = U::regs();
let timeout = 0x8000_0000 / (baudrate as u32 / 40);
@ -198,21 +199,16 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
r.baudrate.write(|w| w.baudrate().variant(baudrate));
});
}
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::Io for BufferedUarte<'d, U, T> {
type Error = core::convert::Infallible;
}
pub fn split<'u>(&'u mut self) -> (BufferedUarteRx<'u, 'd, U, T>, BufferedUarteTx<'u, 'd, U, T>) {
(BufferedUarteRx { inner: self }, BufferedUarteTx { inner: self })
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Read for BufferedUarte<'d, U, T> {
type ReadFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
async fn inner_read<'a>(&'a self, buf: &'a mut [u8]) -> Result<usize, core::convert::Infallible> {
poll_fn(move |cx| {
let mut do_pend = false;
let res = self.inner.with(|state| {
let mut inner = self.inner.borrow_mut();
let res = inner.with(|state| {
compiler_fence(Ordering::SeqCst);
trace!("poll_read");
@ -232,62 +228,18 @@ impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Read for Buffe
Poll::Pending
});
if do_pend {
self.inner.pend();
inner.pend();
}
res
})
.await
}
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::BufRead for BufferedUarte<'d, U, T> {
type FillBufFuture<'a> = impl Future<Output = Result<&'a [u8], Self::Error>>
where
Self: 'a;
fn fill_buf<'a>(&'a mut self) -> Self::FillBufFuture<'a> {
async fn inner_write<'a>(&'a self, buf: &'a [u8]) -> Result<usize, core::convert::Infallible> {
poll_fn(move |cx| {
self.inner.with(|state| {
compiler_fence(Ordering::SeqCst);
trace!("fill_buf");
// We have data ready in buffer? Return it.
let buf = state.rx.pop_buf();
if !buf.is_empty() {
trace!(" got {:?} {:?}", buf.as_ptr() as u32, buf.len());
let buf: &[u8] = buf;
// Safety: buffer lives as long as uart
let buf: &[u8] = unsafe { core::mem::transmute(buf) };
return Poll::Ready(Ok(buf));
}
trace!(" empty");
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 full = state.rx.is_full();
state.rx.pop(amt);
full
});
if signal {
self.inner.pend();
}
}
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Write for BufferedUarte<'d, U, T> {
type WriteFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
poll_fn(move |cx| {
let res = self.inner.with(|state| {
let mut inner = self.inner.borrow_mut();
let res = inner.with(|state| {
trace!("poll_write: {:?}", buf.len());
let tx_buf = state.tx.push_buf();
@ -308,19 +260,16 @@ impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Write for Buff
Poll::Ready(Ok(n))
});
self.inner.pend();
inner.pend();
res
})
.await
}
type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>>
where
Self: 'a;
fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
async fn inner_flush<'a>(&'a self) -> Result<(), core::convert::Infallible> {
poll_fn(move |cx| {
self.inner.with(|state| {
self.inner.borrow_mut().with(|state| {
trace!("poll_flush");
if !state.tx.is_empty() {
@ -332,6 +281,147 @@ impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Write for Buff
Poll::Ready(Ok(()))
})
})
.await
}
async fn inner_fill_buf<'a>(&'a self) -> Result<&'a [u8], core::convert::Infallible> {
poll_fn(move |cx| {
self.inner.borrow_mut().with(|state| {
compiler_fence(Ordering::SeqCst);
trace!("fill_buf");
// We have data ready in buffer? Return it.
let buf = state.rx.pop_buf();
if !buf.is_empty() {
trace!(" got {:?} {:?}", buf.as_ptr() as u32, buf.len());
let buf: &[u8] = buf;
// Safety: buffer lives as long as uart
let buf: &[u8] = unsafe { core::mem::transmute(buf) };
return Poll::Ready(Ok(buf));
}
trace!(" empty");
state.rx_waker.register(cx.waker());
Poll::<Result<&[u8], core::convert::Infallible>>::Pending
})
})
.await
}
fn inner_consume(&self, amt: usize) {
let mut inner = self.inner.borrow_mut();
let signal = inner.with(|state| {
let full = state.rx.is_full();
state.rx.pop(amt);
full
});
if signal {
inner.pend();
}
}
}
pub struct BufferedUarteTx<'u, 'd, U: UarteInstance, T: TimerInstance> {
inner: &'u BufferedUarte<'d, U, T>,
}
pub struct BufferedUarteRx<'u, 'd, U: UarteInstance, T: TimerInstance> {
inner: &'u BufferedUarte<'d, U, T>,
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::Io for BufferedUarte<'d, U, T> {
type Error = core::convert::Infallible;
}
impl<'u, 'd, U: UarteInstance, T: TimerInstance> embedded_io::Io for BufferedUarteRx<'u, 'd, U, T> {
type Error = core::convert::Infallible;
}
impl<'u, 'd, U: UarteInstance, T: TimerInstance> embedded_io::Io for BufferedUarteTx<'u, 'd, U, T> {
type Error = core::convert::Infallible;
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Read for BufferedUarte<'d, U, T> {
type ReadFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
self.inner_read(buf)
}
}
impl<'u, 'd: 'u, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Read for BufferedUarteRx<'u, 'd, U, T> {
type ReadFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
self.inner.inner_read(buf)
}
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::BufRead for BufferedUarte<'d, U, T> {
type FillBufFuture<'a> = impl Future<Output = Result<&'a [u8], Self::Error>>
where
Self: 'a;
fn fill_buf<'a>(&'a mut self) -> Self::FillBufFuture<'a> {
self.inner_fill_buf()
}
fn consume(&mut self, amt: usize) {
self.inner_consume(amt)
}
}
impl<'u, 'd: 'u, U: UarteInstance, T: TimerInstance> embedded_io::asynch::BufRead for BufferedUarteRx<'u, 'd, U, T> {
type FillBufFuture<'a> = impl Future<Output = Result<&'a [u8], Self::Error>>
where
Self: 'a;
fn fill_buf<'a>(&'a mut self) -> Self::FillBufFuture<'a> {
self.inner.inner_fill_buf()
}
fn consume(&mut self, amt: usize) {
self.inner.inner_consume(amt)
}
}
impl<'d, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Write for BufferedUarte<'d, U, T> {
type WriteFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
self.inner_write(buf)
}
type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>>
where
Self: 'a;
fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
self.inner_flush()
}
}
impl<'u, 'd: 'u, U: UarteInstance, T: TimerInstance> embedded_io::asynch::Write for BufferedUarteTx<'u, 'd, U, T> {
type WriteFuture<'a> = impl Future<Output = Result<usize, Self::Error>>
where
Self: 'a;
fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
self.inner.inner_write(buf)
}
type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>>
where
Self: 'a;
fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
self.inner.inner_flush()
}
}