use core::future::{poll_fn, Future}; use core::slice; use core::task::Poll; use embassy_cortex_m::interrupt::{Interrupt, InterruptExt}; use embassy_hal_common::atomic_ring_buffer::RingBuffer; use embassy_sync::waitqueue::AtomicWaker; use super::*; use crate::RegExt; pub struct State { tx_waker: AtomicWaker, tx_buf: RingBuffer, rx_waker: AtomicWaker, rx_buf: RingBuffer, } impl State { pub const fn new() -> Self { Self { rx_buf: RingBuffer::new(), tx_buf: RingBuffer::new(), rx_waker: AtomicWaker::new(), tx_waker: AtomicWaker::new(), } } } pub struct BufferedUart<'d, T: Instance> { pub(crate) rx: BufferedUartRx<'d, T>, pub(crate) tx: BufferedUartTx<'d, T>, } pub struct BufferedUartRx<'d, T: Instance> { pub(crate) phantom: PhantomData<&'d mut T>, } pub struct BufferedUartTx<'d, T: Instance> { pub(crate) phantom: PhantomData<&'d mut T>, } pub(crate) fn init_buffers<'d, T: Instance + 'd>( irq: PeripheralRef<'d, T::Interrupt>, tx_buffer: &'d mut [u8], rx_buffer: &'d mut [u8], ) { let state = T::state(); let len = tx_buffer.len(); unsafe { state.tx_buf.init(tx_buffer.as_mut_ptr(), len) }; let len = rx_buffer.len(); unsafe { state.rx_buf.init(rx_buffer.as_mut_ptr(), len) }; // From the datasheet: // "The transmit interrupt is based on a transition through a level, rather // than on the level itself. When the interrupt and the UART is enabled // before any data is written to the transmit FIFO the interrupt is not set. // The interrupt is only set, after written data leaves the single location // of the transmit FIFO and it becomes empty." // // This means we can leave the interrupt enabled the whole time as long as // we clear it after it happens. The downside is that the we manually have // to pend the ISR when we want data transmission to start. let regs = T::regs(); unsafe { regs.uartimsc().write_set(|w| { w.set_rxim(true); w.set_rtim(true); w.set_txim(true); }); }; irq.set_handler(on_interrupt::); irq.unpend(); irq.enable(); } impl<'d, T: Instance> BufferedUart<'d, T> { pub fn new( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, tx: impl Peripheral

> + 'd, rx: impl Peripheral

> + 'd, tx_buffer: &'d mut [u8], rx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, tx, rx); super::Uart::<'d, T, Async>::init(Some(tx.map_into()), Some(rx.map_into()), None, None, config); init_buffers::(irq, tx_buffer, rx_buffer); Self { rx: BufferedUartRx { phantom: PhantomData }, tx: BufferedUartTx { phantom: PhantomData }, } } pub fn new_with_rtscts( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, tx: impl Peripheral

> + 'd, rx: impl Peripheral

> + 'd, rts: impl Peripheral

> + 'd, cts: impl Peripheral

> + 'd, tx_buffer: &'d mut [u8], rx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, tx, rx, cts, rts); super::Uart::<'d, T, Async>::init( Some(tx.map_into()), Some(rx.map_into()), Some(rts.map_into()), Some(cts.map_into()), config, ); init_buffers::(irq, tx_buffer, rx_buffer); Self { rx: BufferedUartRx { phantom: PhantomData }, tx: BufferedUartTx { phantom: PhantomData }, } } pub fn blocking_write(&mut self, buffer: &[u8]) -> Result { self.tx.blocking_write(buffer) } pub fn blocking_flush(&mut self) -> Result<(), Error> { self.tx.blocking_flush() } pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result { self.rx.blocking_read(buffer) } pub fn split(self) -> (BufferedUartRx<'d, T>, BufferedUartTx<'d, T>) { (self.rx, self.tx) } } impl<'d, T: Instance> BufferedUartRx<'d, T> { pub fn new( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, rx: impl Peripheral

> + 'd, rx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, rx); super::Uart::<'d, T, Async>::init(None, Some(rx.map_into()), None, None, config); init_buffers::(irq, &mut [], rx_buffer); Self { phantom: PhantomData } } pub fn new_with_rts( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, rx: impl Peripheral

> + 'd, rts: impl Peripheral

> + 'd, rx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, rx, rts); super::Uart::<'d, T, Async>::init(None, Some(rx.map_into()), Some(rts.map_into()), None, config); init_buffers::(irq, &mut [], rx_buffer); Self { phantom: PhantomData } } fn read<'a>(buf: &'a mut [u8]) -> impl Future> + 'a { poll_fn(move |cx| { if buf.is_empty() { return Poll::Ready(Ok(0)); } let state = T::state(); let mut rx_reader = unsafe { state.rx_buf.reader() }; let n = rx_reader.pop(|data| { let n = data.len().min(buf.len()); buf[..n].copy_from_slice(&data[..n]); n }); if n == 0 { state.rx_waker.register(cx.waker()); return Poll::Pending; } // (Re-)Enable the interrupt to receive more data in case it was // disabled because the buffer was full. let regs = T::regs(); unsafe { regs.uartimsc().write_set(|w| { w.set_rxim(true); w.set_rtim(true); }); } Poll::Ready(Ok(n)) }) } pub fn blocking_read(&mut self, buf: &mut [u8]) -> Result { if buf.is_empty() { return Ok(0); } loop { let state = T::state(); let mut rx_reader = unsafe { state.rx_buf.reader() }; let n = rx_reader.pop(|data| { let n = data.len().min(buf.len()); buf[..n].copy_from_slice(&data[..n]); n }); if n > 0 { // (Re-)Enable the interrupt to receive more data in case it was // disabled because the buffer was full. let regs = T::regs(); unsafe { regs.uartimsc().write_set(|w| { w.set_rxim(true); w.set_rtim(true); }); } return Ok(n); } } } fn fill_buf<'a>() -> impl Future> { poll_fn(move |cx| { let state = T::state(); let mut rx_reader = unsafe { state.rx_buf.reader() }; let (p, n) = rx_reader.pop_buf(); if n == 0 { state.rx_waker.register(cx.waker()); return Poll::Pending; } let buf = unsafe { slice::from_raw_parts(p, n) }; Poll::Ready(Ok(buf)) }) } fn consume(amt: usize) { let state = T::state(); let mut rx_reader = unsafe { state.rx_buf.reader() }; rx_reader.pop_done(amt); // (Re-)Enable the interrupt to receive more data in case it was // disabled because the buffer was full. let regs = T::regs(); unsafe { regs.uartimsc().write_set(|w| { w.set_rxim(true); w.set_rtim(true); }); } } } impl<'d, T: Instance> BufferedUartTx<'d, T> { pub fn new( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, tx: impl Peripheral

> + 'd, tx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, tx); super::Uart::<'d, T, Async>::init(Some(tx.map_into()), None, None, None, config); init_buffers::(irq, tx_buffer, &mut []); Self { phantom: PhantomData } } pub fn new_with_cts( _uart: impl Peripheral

+ 'd, irq: impl Peripheral

+ 'd, tx: impl Peripheral

> + 'd, cts: impl Peripheral

> + 'd, tx_buffer: &'d mut [u8], config: Config, ) -> Self { into_ref!(irq, tx, cts); super::Uart::<'d, T, Async>::init(Some(tx.map_into()), None, None, Some(cts.map_into()), config); init_buffers::(irq, tx_buffer, &mut []); Self { phantom: PhantomData } } fn write<'a>(buf: &'a [u8]) -> impl Future> + 'a { poll_fn(move |cx| { let state = T::state(); let mut tx_writer = unsafe { 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 { state.tx_waker.register(cx.waker()); return Poll::Pending; } // The TX interrupt only triggers when the there was data in the // FIFO and the number of bytes drops below a threshold. When the // FIFO was empty we have to manually pend the interrupt to shovel // TX data from the buffer into the FIFO. unsafe { T::Interrupt::steal() }.pend(); Poll::Ready(Ok(n)) }) } fn flush() -> impl Future> { poll_fn(move |cx| { let state = T::state(); if !state.tx_buf.is_empty() { state.tx_waker.register(cx.waker()); return Poll::Pending; } Poll::Ready(Ok(())) }) } pub fn blocking_write(&mut self, buf: &[u8]) -> Result { loop { let state = T::state(); let mut tx_writer = unsafe { 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 { // The TX interrupt only triggers when the there was data in the // FIFO and the number of bytes drops below a threshold. When the // FIFO was empty we have to manually pend the interrupt to shovel // TX data from the buffer into the FIFO. unsafe { T::Interrupt::steal() }.pend(); return Ok(n); } } } pub fn blocking_flush(&mut self) -> Result<(), Error> { loop { let state = T::state(); if state.tx_buf.is_empty() { return Ok(()); } } } } impl<'d, T: Instance> Drop for BufferedUartRx<'d, T> { fn drop(&mut self) { let state = T::state(); unsafe { state.rx_buf.deinit(); // TX is inactive if the the buffer is not available. // We can now unregister the interrupt handler if state.tx_buf.len() == 0 { T::Interrupt::steal().disable(); } } } } impl<'d, T: Instance> Drop for BufferedUartTx<'d, T> { fn drop(&mut self) { let state = T::state(); unsafe { state.tx_buf.deinit(); // RX is inactive if the the buffer is not available. // We can now unregister the interrupt handler if state.rx_buf.len() == 0 { T::Interrupt::steal().disable(); } } } } pub(crate) unsafe fn on_interrupt(_: *mut ()) { let r = T::regs(); let s = T::state(); unsafe { // Clear TX and error interrupt flags // RX interrupt flags are cleared by reading from the FIFO. let ris = r.uartris().read(); r.uarticr().write(|w| { w.set_txic(ris.txris()); w.set_feic(ris.feris()); w.set_peic(ris.peris()); w.set_beic(ris.beris()); w.set_oeic(ris.oeris()); }); trace!("on_interrupt ris={:#X}", ris.0); // Errors if ris.feris() { warn!("Framing error"); } if ris.peris() { warn!("Parity error"); } if ris.beris() { warn!("Break error"); } if ris.oeris() { warn!("Overrun error"); } // RX let mut rx_writer = s.rx_buf.writer(); let rx_buf = rx_writer.push_slice(); let mut n_read = 0; for rx_byte in rx_buf { if r.uartfr().read().rxfe() { break; } *rx_byte = r.uartdr().read().data(); n_read += 1; } if n_read > 0 { rx_writer.push_done(n_read); s.rx_waker.wake(); } // Disable any further RX interrupts when the buffer becomes full. if s.rx_buf.is_full() { r.uartimsc().write_clear(|w| { w.set_rxim(true); w.set_rtim(true); }); } // TX let mut tx_reader = s.tx_buf.reader(); let tx_buf = tx_reader.pop_slice(); let mut n_written = 0; for tx_byte in tx_buf.iter_mut() { if r.uartfr().read().txff() { break; } r.uartdr().write(|w| w.set_data(*tx_byte)); n_written += 1; } if n_written > 0 { tx_reader.pop_done(n_written); s.tx_waker.wake(); } // The TX interrupt only triggers once when the FIFO threshold is // crossed. No need to disable it when the buffer becomes empty // as it does re-trigger anymore once we have cleared it. } } impl embedded_io::Error for Error { fn kind(&self) -> embedded_io::ErrorKind { embedded_io::ErrorKind::Other } } impl<'d, T: Instance> embedded_io::Io for BufferedUart<'d, T> { type Error = Error; } impl<'d, T: Instance> embedded_io::Io for BufferedUartRx<'d, T> { type Error = Error; } impl<'d, T: Instance> embedded_io::Io for BufferedUartTx<'d, T> { type Error = Error; } impl<'d, T: Instance + 'd> embedded_io::asynch::Read for BufferedUart<'d, T> { async fn read(&mut self, buf: &mut [u8]) -> Result { BufferedUartRx::<'d, T>::read(buf).await } } impl<'d, T: Instance + 'd> embedded_io::asynch::Read for BufferedUartRx<'d, T> { async fn read(&mut self, buf: &mut [u8]) -> Result { Self::read(buf).await } } impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for BufferedUart<'d, T> { async fn fill_buf(&mut self) -> Result<&[u8], Self::Error> { BufferedUartRx::<'d, T>::fill_buf().await } fn consume(&mut self, amt: usize) { BufferedUartRx::<'d, T>::consume(amt) } } impl<'d, T: Instance + 'd> embedded_io::asynch::BufRead for BufferedUartRx<'d, T> { async fn fill_buf(&mut self) -> Result<&[u8], Self::Error> { Self::fill_buf().await } fn consume(&mut self, amt: usize) { Self::consume(amt) } } impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUart<'d, T> { async fn write(&mut self, buf: &[u8]) -> Result { BufferedUartTx::<'d, T>::write(buf).await } async fn flush(&mut self) -> Result<(), Self::Error> { BufferedUartTx::<'d, T>::flush().await } } impl<'d, T: Instance + 'd> embedded_io::asynch::Write for BufferedUartTx<'d, T> { async fn write(&mut self, buf: &[u8]) -> Result { Self::write(buf).await } async fn flush(&mut self) -> Result<(), Self::Error> { Self::flush().await } } impl<'d, T: Instance + 'd> embedded_io::blocking::Read for BufferedUart<'d, T> { fn read(&mut self, buf: &mut [u8]) -> Result { self.rx.blocking_read(buf) } } impl<'d, T: Instance + 'd> embedded_io::blocking::Read for BufferedUartRx<'d, T> { fn read(&mut self, buf: &mut [u8]) -> Result { self.blocking_read(buf) } } impl<'d, T: Instance + 'd> embedded_io::blocking::Write for BufferedUart<'d, T> { fn write(&mut self, buf: &[u8]) -> Result { self.tx.blocking_write(buf) } fn flush(&mut self) -> Result<(), Self::Error> { self.tx.blocking_flush() } } impl<'d, T: Instance + 'd> embedded_io::blocking::Write for BufferedUartTx<'d, T> { fn write(&mut self, buf: &[u8]) -> Result { self.blocking_write(buf) } fn flush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } } mod eh02 { use super::*; impl<'d, T: Instance> embedded_hal_02::serial::Read for BufferedUartRx<'d, T> { type Error = Error; fn read(&mut self) -> Result> { let r = T::regs(); unsafe { if r.uartfr().read().rxfe() { return Err(nb::Error::WouldBlock); } let dr = r.uartdr().read(); if dr.oe() { Err(nb::Error::Other(Error::Overrun)) } else if dr.be() { Err(nb::Error::Other(Error::Break)) } else if dr.pe() { Err(nb::Error::Other(Error::Parity)) } else if dr.fe() { Err(nb::Error::Other(Error::Framing)) } else { Ok(dr.data()) } } } } impl<'d, T: Instance> embedded_hal_02::blocking::serial::Write for BufferedUartTx<'d, T> { type Error = Error; fn bwrite_all(&mut self, mut buffer: &[u8]) -> Result<(), Self::Error> { while !buffer.is_empty() { match self.blocking_write(buffer) { Ok(0) => panic!("zero-length write."), Ok(n) => buffer = &buffer[n..], Err(e) => return Err(e), } } Ok(()) } fn bflush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } } impl<'d, T: Instance> embedded_hal_02::serial::Read for BufferedUart<'d, T> { type Error = Error; fn read(&mut self) -> Result> { embedded_hal_02::serial::Read::read(&mut self.rx) } } impl<'d, T: Instance> embedded_hal_02::blocking::serial::Write for BufferedUart<'d, T> { type Error = Error; fn bwrite_all(&mut self, mut buffer: &[u8]) -> Result<(), Self::Error> { while !buffer.is_empty() { match self.blocking_write(buffer) { Ok(0) => panic!("zero-length write."), Ok(n) => buffer = &buffer[n..], Err(e) => return Err(e), } } Ok(()) } fn bflush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } } } #[cfg(feature = "unstable-traits")] mod eh1 { use super::*; impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for BufferedUart<'d, T> { type Error = Error; } impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for BufferedUartTx<'d, T> { type Error = Error; } impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for BufferedUartRx<'d, T> { type Error = Error; } impl<'d, T: Instance> embedded_hal_nb::serial::Read for BufferedUartRx<'d, T> { fn read(&mut self) -> nb::Result { embedded_hal_02::serial::Read::read(self) } } impl<'d, T: Instance> embedded_hal_1::serial::Write for BufferedUartTx<'d, T> { fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> { self.blocking_write(buffer).map(drop) } fn flush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } } impl<'d, T: Instance> embedded_hal_nb::serial::Write for BufferedUartTx<'d, T> { fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> { self.blocking_write(&[char]).map(drop).map_err(nb::Error::Other) } fn flush(&mut self) -> nb::Result<(), Self::Error> { self.blocking_flush().map_err(nb::Error::Other) } } impl<'d, T: Instance> embedded_hal_nb::serial::Read for BufferedUart<'d, T> { fn read(&mut self) -> Result> { embedded_hal_02::serial::Read::read(&mut self.rx) } } impl<'d, T: Instance> embedded_hal_1::serial::Write for BufferedUart<'d, T> { fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> { self.blocking_write(buffer).map(drop) } fn flush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } } impl<'d, T: Instance> embedded_hal_nb::serial::Write for BufferedUart<'d, T> { fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> { self.blocking_write(&[char]).map(drop).map_err(nb::Error::Other) } fn flush(&mut self) -> nb::Result<(), Self::Error> { self.blocking_flush().map_err(nb::Error::Other) } } } #[cfg(all( feature = "unstable-traits", feature = "nightly", feature = "_todo_embedded_hal_serial" ))] mod eha { use core::future::Future; use super::*; impl<'d, T: Instance> embedded_hal_async::serial::Write for BufferedUartTx<'d, T> { type WriteFuture<'a> = impl Future> + 'a where Self: 'a; fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> { Self::write(buf) } type FlushFuture<'a> = impl Future> + 'a where Self: 'a; fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> { Self::flush() } } impl<'d, T: Instance> embedded_hal_async::serial::Read for BufferedUartRx<'d, T> { type ReadFuture<'a> = impl Future> + 'a where Self: 'a; fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> { Self::read(buf) } } impl<'d, T: Instance> embedded_hal_async::serial::Write for BufferedUart<'d, T> { type WriteFuture<'a> = impl Future> + 'a where Self: 'a; fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> { BufferedUartTx::<'d, T>::write(buf) } type FlushFuture<'a> = impl Future> + 'a where Self: 'a; fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> { BufferedUartTx::<'d, T>::flush() } } impl<'d, T: Instance> embedded_hal_async::serial::Read for BufferedUart<'d, T> { type ReadFuture<'a> = impl Future> + 'a where Self: 'a; fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> { BufferedUartRx::<'d, T>::read(buf) } } }