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rp/uart: report errors from dma receive

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This commit is contained in:
pennae
2023-04-29 10:30:04 +02:00
parent 1d5adb8974
commit b58b9ff390
4 changed files with 375 additions and 25 deletions
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2
embassy-rp/src/uart/buffered.rs
View File

@ -74,7 +74,7 @@ pub(crate) fn init_buffers<'d, T: Instance + 'd>(
// to pend the ISR when we want data transmission to start.
let regs = T::regs();
unsafe {
regs.uartimsc().write_set(|w| {
regs.uartimsc().write(|w| {
w.set_rxim(true);
w.set_rtim(true);
w.set_txim(true);

151
embassy-rp/src/uart/mod.rs
View File

@ -1,7 +1,14 @@
use core::future::poll_fn;
use core::marker::PhantomData;
use core::task::Poll;
use atomic_polyfill::{AtomicU16, Ordering};
use embassy_cortex_m::interrupt::{Interrupt, InterruptExt};
use embassy_futures::select::{select, Either};
use embassy_hal_common::{into_ref, PeripheralRef};
use embassy_sync::waitqueue::AtomicWaker;
use embassy_time::{Duration, Timer};
use pac::uart::regs::Uartris;
use crate::clocks::clk_peri_freq;
use crate::dma::{AnyChannel, Channel};
@ -97,6 +104,11 @@ pub enum Error {
Framing,
}
pub struct DmaState {
rx_err_waker: AtomicWaker,
rx_errs: AtomicU16,
}
pub struct Uart<'d, T: Instance, M: Mode> {
tx: UartTx<'d, T, M>,
rx: UartRx<'d, T, M>,
@ -223,15 +235,26 @@ impl<'d, T: Instance, M: Mode> UartRx<'d, T, M> {
pub fn new(
_uart: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(rx, rx_dma);
into_ref!(rx, irq, rx_dma);
Uart::<T, M>::init(None, Some(rx.map_into()), None, None, config);
Self::new_inner(Some(rx_dma.map_into()))
Self::new_inner(Some(irq), Some(rx_dma.map_into()))
}
fn new_inner(rx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
fn new_inner(irq: Option<PeripheralRef<'d, T::Interrupt>>, rx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
debug_assert_eq!(irq.is_some(), rx_dma.is_some());
if let Some(irq) = irq {
unsafe {
// disable all error interrupts initially
T::regs().uartimsc().write(|w| w.0 = 0);
}
irq.set_handler(on_interrupt::<T>);
irq.unpend();
irq.enable();
}
Self {
rx_dma,
phantom: PhantomData,
@ -271,6 +294,16 @@ impl<'d, T: Instance, M: Mode> UartRx<'d, T, M> {
}
}
impl<'d, T: Instance, M: Mode> Drop for UartRx<'d, T, M> {
fn drop(&mut self) {
if let Some(_) = self.rx_dma {
unsafe {
T::Interrupt::steal().disable();
}
}
}
}
impl<'d, T: Instance> UartRx<'d, T, Blocking> {
pub fn new_blocking(
_uart: impl Peripheral<P = T> + 'd,
@ -279,7 +312,7 @@ impl<'d, T: Instance> UartRx<'d, T, Blocking> {
) -> Self {
into_ref!(rx);
Uart::<T, Blocking>::init(None, Some(rx.map_into()), None, None, config);
Self::new_inner(None)
Self::new_inner(None, None)
}
#[cfg(feature = "nightly")]
@ -296,19 +329,93 @@ impl<'d, T: Instance> UartRx<'d, T, Blocking> {
}
}
unsafe fn on_interrupt<T: Instance>(_: *mut ()) {
let uart = T::regs();
let state = T::dma_state();
let errs = uart.uartris().read();
state.rx_errs.store(errs.0 as u16, Ordering::Relaxed);
state.rx_err_waker.wake();
// disable the error interrupts instead of clearing the flags. clearing the
// flags would allow the dma transfer to continue, potentially signaling
// completion before we can check for errors that happened *during* the transfer.
uart.uartimsc().write_clear(|w| w.0 = errs.0);
}
impl<'d, T: Instance> UartRx<'d, T, Async> {
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
// clear error flags before we drain the fifo. errors that have accumulated
// in the flags will also be present in the fifo.
T::dma_state().rx_errs.store(0, Ordering::Relaxed);
unsafe {
T::regs().uarticr().write(|w| {
w.set_oeic(true);
w.set_beic(true);
w.set_peic(true);
w.set_feic(true);
});
}
// then drain the fifo. we need to read at most 32 bytes. errors that apply
// to fifo bytes will be reported directly.
let buffer = match {
let limit = buffer.len().min(32);
self.drain_fifo(&mut buffer[0..limit])
} {
Ok(len) if len < buffer.len() => &mut buffer[len..],
Ok(_) => return Ok(()),
Err(e) => return Err(e),
};
// start a dma transfer. if errors have happened in the interim some error
// interrupt flags will have been raised, and those will be picked up immediately
// by the interrupt handler.
let ch = self.rx_dma.as_mut().unwrap();
let transfer = unsafe {
T::regs().uartimsc().write_set(|w| {
w.set_oeim(true);
w.set_beim(true);
w.set_peim(true);
w.set_feim(true);
});
T::regs().uartdmacr().write_set(|reg| {
reg.set_rxdmae(true);
reg.set_dmaonerr(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)
};
transfer.await;
Ok(())
// wait for either the transfer to complete or an error to happen.
let transfer_result = select(
transfer,
poll_fn(|cx| {
T::dma_state().rx_err_waker.register(cx.waker());
match T::dma_state().rx_errs.swap(0, Ordering::Relaxed) {
0 => Poll::Pending,
e => Poll::Ready(Uartris(e as u32)),
}
}),
)
.await;
let errors = match transfer_result {
Either::First(()) => return Ok(()),
Either::Second(e) => e,
};
if errors.0 == 0 {
return Ok(());
} else if errors.oeris() {
return Err(Error::Overrun);
} else if errors.beris() {
return Err(Error::Break);
} else if errors.peris() {
return Err(Error::Parity);
} else if errors.feris() {
return Err(Error::Framing);
}
unreachable!("unrecognized rx error");
}
}
@ -321,7 +428,7 @@ impl<'d, T: Instance> Uart<'d, T, Blocking> {
config: Config,
) -> Self {
into_ref!(tx, rx);
Self::new_inner(uart, tx.map_into(), rx.map_into(), None, None, None, None, config)
Self::new_inner(uart, tx.map_into(), rx.map_into(), None, None, None, None, None, config)
}
/// Create a new UART with hardware flow control (RTS/CTS)
@ -342,6 +449,7 @@ impl<'d, T: Instance> Uart<'d, T, Blocking> {
Some(cts.map_into()),
None,
None,
None,
config,
)
}
@ -370,17 +478,19 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
tx_dma: impl Peripheral<P = impl Channel> + 'd,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx, tx_dma, rx_dma);
into_ref!(tx, rx, irq, tx_dma, rx_dma);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
None,
None,
Some(irq),
Some(tx_dma.map_into()),
Some(rx_dma.map_into()),
config,
@ -394,17 +504,19 @@ impl<'d, T: Instance> Uart<'d, T, Async> {
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
tx_dma: impl Peripheral<P = impl Channel> + 'd,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx, cts, rts, tx_dma, rx_dma);
into_ref!(tx, rx, cts, rts, irq, tx_dma, rx_dma);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
Some(rts.map_into()),
Some(cts.map_into()),
Some(irq),
Some(tx_dma.map_into()),
Some(rx_dma.map_into()),
config,
@ -419,6 +531,7 @@ impl<'d, T: Instance + 'd, M: Mode> Uart<'d, T, M> {
mut rx: PeripheralRef<'d, AnyPin>,
mut rts: Option<PeripheralRef<'d, AnyPin>>,
mut cts: Option<PeripheralRef<'d, AnyPin>>,
irq: Option<PeripheralRef<'d, T::Interrupt>>,
tx_dma: Option<PeripheralRef<'d, AnyChannel>>,
rx_dma: Option<PeripheralRef<'d, AnyChannel>>,
config: Config,
@ -433,7 +546,7 @@ impl<'d, T: Instance + 'd, M: Mode> Uart<'d, T, M> {
Self {
tx: UartTx::new_inner(tx_dma),
rx: UartRx::new_inner(rx_dma),
rx: UartRx::new_inner(irq, rx_dma),
}
}
@ -761,6 +874,7 @@ mod sealed {
pub trait Instance {
const TX_DREQ: u8;
const RX_DREQ: u8;
const ID: usize;
type Interrupt: crate::interrupt::Interrupt;
@ -768,6 +882,8 @@ mod sealed {
#[cfg(feature = "nightly")]
fn buffered_state() -> &'static buffered::State;
fn dma_state() -> &'static DmaState;
}
pub trait TxPin<T: Instance> {}
pub trait RxPin<T: Instance> {}
@ -793,10 +909,11 @@ impl_mode!(Async);
pub trait Instance: sealed::Instance {}
macro_rules! impl_instance {
($inst:ident, $irq:ident, $tx_dreq:expr, $rx_dreq:expr) => {
($inst:ident, $irq:ident, $id:expr, $tx_dreq:expr, $rx_dreq:expr) => {
impl sealed::Instance for peripherals::$inst {
const TX_DREQ: u8 = $tx_dreq;
const RX_DREQ: u8 = $rx_dreq;
const ID: usize = $id;
type Interrupt = crate::interrupt::$irq;
@ -809,13 +926,21 @@ macro_rules! impl_instance {
static STATE: buffered::State = buffered::State::new();
&STATE
}
fn dma_state() -> &'static DmaState {
static STATE: DmaState = DmaState {
rx_err_waker: AtomicWaker::new(),
rx_errs: AtomicU16::new(0),
};
&STATE
}
}
impl Instance for peripherals::$inst {}
};
}
impl_instance!(UART0, UART0_IRQ, 20, 21);
impl_instance!(UART1, UART1_IRQ, 22, 23);
impl_instance!(UART0, UART0_IRQ, 0, 20, 21);
impl_instance!(UART1, UART1_IRQ, 1, 22, 23);
pub trait TxPin<T: Instance>: sealed::TxPin<T> + crate::gpio::Pin {}
pub trait RxPin<T: Instance>: sealed::RxPin<T> + crate::gpio::Pin {}