766 lines
21 KiB
Rust

use core::future::poll_fn;
use core::marker::PhantomData;
use core::slice;
use core::sync::atomic::{AtomicBool, AtomicU8, Ordering};
use core::task::Poll;
use embassy_embedded_hal::SetConfig;
use embassy_hal_internal::atomic_ring_buffer::RingBuffer;
use embassy_hal_internal::{into_ref, Peripheral};
use embassy_sync::waitqueue::AtomicWaker;
#[cfg(not(any(usart_v1, usart_v2)))]
use super::DePin;
use super::{
clear_interrupt_flags, configure, rdr, reconfigure, sr, tdr, Config, ConfigError, CtsPin, Error, Info, Instance,
Regs, RtsPin, RxPin, TxPin,
};
use crate::gpio::AFType;
use crate::interrupt::typelevel::Interrupt as _;
use crate::interrupt::{self, InterruptExt};
use crate::rcc;
use crate::time::Hertz;
/// Interrupt handler.
pub struct InterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
unsafe fn on_interrupt() {
on_interrupt(T::info().regs, T::buffered_state())
}
}
unsafe fn on_interrupt(r: Regs, state: &'static State) {
// RX
let sr_val = sr(r).read();
// On v1 & v2, reading DR clears the rxne, error and idle interrupt
// flags. Keep this close to the SR read to reduce the chance of a
// flag being set in-between.
let dr = if sr_val.rxne() || cfg!(any(usart_v1, usart_v2)) && (sr_val.ore() || sr_val.idle()) {
Some(rdr(r).read_volatile())
} else {
None
};
clear_interrupt_flags(r, sr_val);
if sr_val.pe() {
warn!("Parity error");
}
if sr_val.fe() {
warn!("Framing error");
}
if sr_val.ne() {
warn!("Noise error");
}
if sr_val.ore() {
warn!("Overrun error");
}
if sr_val.rxne() {
let mut rx_writer = state.rx_buf.writer();
let buf = rx_writer.push_slice();
if !buf.is_empty() {
if let Some(byte) = dr {
buf[0] = byte;
rx_writer.push_done(1);
}
} else {
// FIXME: Should we disable any further RX interrupts when the buffer becomes full.
}
if !state.rx_buf.is_empty() {
state.rx_waker.wake();
}
}
if sr_val.idle() {
state.rx_waker.wake();
}
// With `usart_v4` hardware FIFO is enabled and Transmission complete (TC)
// indicates that all bytes are pushed out from the FIFO.
// For other usart variants it shows that last byte from the buffer was just sent.
if sr_val.tc() {
// For others it is cleared above with `clear_interrupt_flags`.
#[cfg(any(usart_v1, usart_v2))]
sr(r).modify(|w| w.set_tc(false));
r.cr1().modify(|w| {
w.set_tcie(false);
});
state.tx_done.store(true, Ordering::Release);
state.tx_waker.wake();
}
// TX
if sr(r).read().txe() {
let mut tx_reader = state.tx_buf.reader();
let buf = tx_reader.pop_slice();
if !buf.is_empty() {
r.cr1().modify(|w| {
w.set_txeie(true);
});
// Enable transmission complete interrupt when last byte is going to be sent out.
if buf.len() == 1 {
r.cr1().modify(|w| {
w.set_tcie(true);
});
}
tdr(r).write_volatile(buf[0].into());
tx_reader.pop_done(1);
} else {
// Disable interrupt until we have something to transmit again.
r.cr1().modify(|w| {
w.set_txeie(false);
});
}
}
}
pub(super) struct State {
rx_waker: AtomicWaker,
rx_buf: RingBuffer,
tx_waker: AtomicWaker,
tx_buf: RingBuffer,
tx_done: AtomicBool,
tx_rx_refcount: AtomicU8,
}
impl State {
pub(super) const fn new() -> Self {
Self {
rx_buf: RingBuffer::new(),
tx_buf: RingBuffer::new(),
rx_waker: AtomicWaker::new(),
tx_waker: AtomicWaker::new(),
tx_done: AtomicBool::new(true),
tx_rx_refcount: AtomicU8::new(0),
}
}
}
/// Bidirectional buffered UART
pub struct BufferedUart<'d> {
rx: BufferedUartRx<'d>,
tx: BufferedUartTx<'d>,
}
/// Tx-only buffered UART
///
/// Created with [BufferedUart::split]
pub struct BufferedUartTx<'d> {
info: &'static Info,
state: &'static State,
kernel_clock: Hertz,
_phantom: PhantomData<&'d mut ()>,
}
/// Rx-only buffered UART
///
/// Created with [BufferedUart::split]
pub struct BufferedUartRx<'d> {
info: &'static Info,
state: &'static State,
kernel_clock: Hertz,
_phantom: PhantomData<&'d mut ()>,
}
impl<'d> SetConfig for BufferedUart<'d> {
type Config = Config;
type ConfigError = ConfigError;
fn set_config(&mut self, config: &Self::Config) -> Result<(), Self::ConfigError> {
self.set_config(config)
}
}
impl<'d> SetConfig for BufferedUartRx<'d> {
type Config = Config;
type ConfigError = ConfigError;
fn set_config(&mut self, config: &Self::Config) -> Result<(), Self::ConfigError> {
self.set_config(config)
}
}
impl<'d> SetConfig for BufferedUartTx<'d> {
type Config = Config;
type ConfigError = ConfigError;
fn set_config(&mut self, config: &Self::Config) -> Result<(), Self::ConfigError> {
self.set_config(config)
}
}
impl<'d> BufferedUart<'d> {
/// Create a new bidirectional buffered UART driver
pub fn new<T: Instance>(
peri: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_buffer: &'d mut [u8],
rx_buffer: &'d mut [u8],
config: Config,
) -> Result<Self, ConfigError> {
rcc::enable_and_reset::<T>();
Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
}
/// Create a new bidirectional buffered UART driver with request-to-send and clear-to-send pins
pub fn new_with_rtscts<T: Instance>(
peri: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<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,
) -> Result<Self, ConfigError> {
into_ref!(cts, rts);
rcc::enable_and_reset::<T>();
rts.set_as_af(rts.af_num(), AFType::OutputPushPull);
cts.set_as_af(cts.af_num(), AFType::Input);
T::info().regs.cr3().write(|w| {
w.set_rtse(true);
w.set_ctse(true);
});
Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
}
/// Create a new bidirectional buffered UART driver with a driver-enable pin
#[cfg(not(any(usart_v1, usart_v2)))]
pub fn new_with_de<T: Instance>(
peri: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
de: impl Peripheral<P = impl DePin<T>> + 'd,
tx_buffer: &'d mut [u8],
rx_buffer: &'d mut [u8],
config: Config,
) -> Result<Self, ConfigError> {
into_ref!(de);
rcc::enable_and_reset::<T>();
de.set_as_af(de.af_num(), AFType::OutputPushPull);
T::info().regs.cr3().write(|w| {
w.set_dem(true);
});
Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
}
fn new_inner<T: Instance>(
_peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_buffer: &'d mut [u8],
rx_buffer: &'d mut [u8],
config: Config,
) -> Result<Self, ConfigError> {
into_ref!(_peri, rx, tx);
let info = T::info();
let state = T::buffered_state();
let kernel_clock = T::frequency();
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) };
let r = info.regs;
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
configure(info, kernel_clock, &config, true, true)?;
r.cr1().modify(|w| {
w.set_rxneie(true);
w.set_idleie(true);
});
T::Interrupt::unpend();
unsafe { T::Interrupt::enable() };
state.tx_rx_refcount.store(2, Ordering::Relaxed);
Ok(Self {
rx: BufferedUartRx {
info,
state,
kernel_clock,
_phantom: PhantomData,
},
tx: BufferedUartTx {
info,
state,
kernel_clock,
_phantom: PhantomData,
},
})
}
/// Split the driver into a Tx and Rx part (useful for sending to separate tasks)
pub fn split(self) -> (BufferedUartTx<'d>, BufferedUartRx<'d>) {
(self.tx, self.rx)
}
/// Reconfigure the driver
pub fn set_config(&mut self, config: &Config) -> Result<(), ConfigError> {
reconfigure(self.rx.info, self.rx.kernel_clock, config)?;
self.rx.info.regs.cr1().modify(|w| {
w.set_rxneie(true);
w.set_idleie(true);
});
Ok(())
}
}
impl<'d> BufferedUartRx<'d> {
async fn read(&self, buf: &mut [u8]) -> Result<usize, Error> {
poll_fn(move |cx| {
let state = self.state;
let mut rx_reader = unsafe { state.rx_buf.reader() };
let data = rx_reader.pop_slice();
if !data.is_empty() {
let len = data.len().min(buf.len());
buf[..len].copy_from_slice(&data[..len]);
let do_pend = state.rx_buf.is_full();
rx_reader.pop_done(len);
if do_pend {
self.info.interrupt.pend();
}
return Poll::Ready(Ok(len));
}
state.rx_waker.register(cx.waker());
Poll::Pending
})
.await
}
fn blocking_read(&self, buf: &mut [u8]) -> Result<usize, Error> {
loop {
let state = self.state;
let mut rx_reader = unsafe { state.rx_buf.reader() };
let data = rx_reader.pop_slice();
if !data.is_empty() {
let len = data.len().min(buf.len());
buf[..len].copy_from_slice(&data[..len]);
let do_pend = state.rx_buf.is_full();
rx_reader.pop_done(len);
if do_pend {
self.info.interrupt.pend();
}
return Ok(len);
}
}
}
async fn fill_buf(&self) -> Result<&[u8], Error> {
poll_fn(move |cx| {
let state = self.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))
})
.await
}
fn consume(&self, amt: usize) {
let state = self.state;
let mut rx_reader = unsafe { state.rx_buf.reader() };
let full = state.rx_buf.is_full();
rx_reader.pop_done(amt);
if full {
self.info.interrupt.pend();
}
}
/// Reconfigure the driver
pub fn set_config(&mut self, config: &Config) -> Result<(), ConfigError> {
reconfigure(self.info, self.kernel_clock, config)?;
self.info.regs.cr1().modify(|w| {
w.set_rxneie(true);
w.set_idleie(true);
});
Ok(())
}
}
impl<'d> BufferedUartTx<'d> {
async fn write(&self, buf: &[u8]) -> Result<usize, Error> {
poll_fn(move |cx| {
let state = self.state;
state.tx_done.store(false, Ordering::Release);
let empty = state.tx_buf.is_empty();
let mut tx_writer = unsafe { state.tx_buf.writer() };
let data = tx_writer.push_slice();
if data.is_empty() {
state.tx_waker.register(cx.waker());
return Poll::Pending;
}
let n = data.len().min(buf.len());
data[..n].copy_from_slice(&buf[..n]);
tx_writer.push_done(n);
if empty {
self.info.interrupt.pend();
}
Poll::Ready(Ok(n))
})
.await
}
async fn flush(&self) -> Result<(), Error> {
poll_fn(move |cx| {
let state = self.state;
if !state.tx_done.load(Ordering::Acquire) {
state.tx_waker.register(cx.waker());
return Poll::Pending;
}
Poll::Ready(Ok(()))
})
.await
}
fn blocking_write(&self, buf: &[u8]) -> Result<usize, Error> {
loop {
let state = self.state;
let empty = state.tx_buf.is_empty();
let mut tx_writer = unsafe { state.tx_buf.writer() };
let data = tx_writer.push_slice();
if !data.is_empty() {
let n = data.len().min(buf.len());
data[..n].copy_from_slice(&buf[..n]);
tx_writer.push_done(n);
if empty {
self.info.interrupt.pend();
}
return Ok(n);
}
}
}
fn blocking_flush(&self) -> Result<(), Error> {
loop {
let state = self.state;
if state.tx_buf.is_empty() {
return Ok(());
}
}
}
/// Reconfigure the driver
pub fn set_config(&mut self, config: &Config) -> Result<(), ConfigError> {
reconfigure(self.info, self.kernel_clock, config)?;
self.info.regs.cr1().modify(|w| {
w.set_rxneie(true);
w.set_idleie(true);
});
Ok(())
}
}
impl<'d> Drop for BufferedUartRx<'d> {
fn drop(&mut self) {
let state = self.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 {
self.info.interrupt.disable();
}
}
drop_tx_rx(self.info, state);
}
}
impl<'d> Drop for BufferedUartTx<'d> {
fn drop(&mut self) {
let state = self.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 {
self.info.interrupt.disable();
}
}
drop_tx_rx(self.info, state);
}
}
fn drop_tx_rx(info: &Info, state: &State) {
// We cannot use atomic subtraction here, because it's not supported for all targets
let is_last_drop = critical_section::with(|_| {
let refcount = state.tx_rx_refcount.load(Ordering::Relaxed);
assert!(refcount >= 1);
state.tx_rx_refcount.store(refcount - 1, Ordering::Relaxed);
refcount == 1
});
if is_last_drop {
info.rcc.disable();
}
}
impl<'d> embedded_io_async::ErrorType for BufferedUart<'d> {
type Error = Error;
}
impl<'d> embedded_io_async::ErrorType for BufferedUartRx<'d> {
type Error = Error;
}
impl<'d> embedded_io_async::ErrorType for BufferedUartTx<'d> {
type Error = Error;
}
impl<'d> embedded_io_async::Read for BufferedUart<'d> {
async fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
self.rx.read(buf).await
}
}
impl<'d> embedded_io_async::Read for BufferedUartRx<'d> {
async fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
Self::read(self, buf).await
}
}
impl<'d> embedded_io_async::BufRead for BufferedUart<'d> {
async fn fill_buf(&mut self) -> Result<&[u8], Self::Error> {
self.rx.fill_buf().await
}
fn consume(&mut self, amt: usize) {
self.rx.consume(amt)
}
}
impl<'d> embedded_io_async::BufRead for BufferedUartRx<'d> {
async fn fill_buf(&mut self) -> Result<&[u8], Self::Error> {
Self::fill_buf(self).await
}
fn consume(&mut self, amt: usize) {
Self::consume(self, amt)
}
}
impl<'d> embedded_io_async::Write for BufferedUart<'d> {
async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
self.tx.write(buf).await
}
async fn flush(&mut self) -> Result<(), Self::Error> {
self.tx.flush().await
}
}
impl<'d> embedded_io_async::Write for BufferedUartTx<'d> {
async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
Self::write(self, buf).await
}
async fn flush(&mut self) -> Result<(), Self::Error> {
Self::flush(self).await
}
}
impl<'d> embedded_io::Read for BufferedUart<'d> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
self.rx.blocking_read(buf)
}
}
impl<'d> embedded_io::Read for BufferedUartRx<'d> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
self.blocking_read(buf)
}
}
impl<'d> embedded_io::Write for BufferedUart<'d> {
fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
self.tx.blocking_write(buf)
}
fn flush(&mut self) -> Result<(), Self::Error> {
self.tx.blocking_flush()
}
}
impl<'d> embedded_io::Write for BufferedUartTx<'d> {
fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
Self::blocking_write(self, buf)
}
fn flush(&mut self) -> Result<(), Self::Error> {
Self::blocking_flush(self)
}
}
impl<'d> embedded_hal_02::serial::Read<u8> for BufferedUartRx<'d> {
type Error = Error;
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
let r = self.info.regs;
unsafe {
let sr = sr(r).read();
if sr.pe() {
rdr(r).read_volatile();
Err(nb::Error::Other(Error::Parity))
} else if sr.fe() {
rdr(r).read_volatile();
Err(nb::Error::Other(Error::Framing))
} else if sr.ne() {
rdr(r).read_volatile();
Err(nb::Error::Other(Error::Noise))
} else if sr.ore() {
rdr(r).read_volatile();
Err(nb::Error::Other(Error::Overrun))
} else if sr.rxne() {
Ok(rdr(r).read_volatile())
} else {
Err(nb::Error::WouldBlock)
}
}
}
}
impl<'d> embedded_hal_02::blocking::serial::Write<u8> for BufferedUartTx<'d> {
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> embedded_hal_02::serial::Read<u8> for BufferedUart<'d> {
type Error = Error;
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
embedded_hal_02::serial::Read::read(&mut self.rx)
}
}
impl<'d> embedded_hal_02::blocking::serial::Write<u8> for BufferedUart<'d> {
type Error = Error;
fn bwrite_all(&mut self, mut buffer: &[u8]) -> Result<(), Self::Error> {
while !buffer.is_empty() {
match self.tx.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.tx.blocking_flush()
}
}
impl<'d> embedded_hal_nb::serial::ErrorType for BufferedUart<'d> {
type Error = Error;
}
impl<'d> embedded_hal_nb::serial::ErrorType for BufferedUartTx<'d> {
type Error = Error;
}
impl<'d> embedded_hal_nb::serial::ErrorType for BufferedUartRx<'d> {
type Error = Error;
}
impl<'d> embedded_hal_nb::serial::Read for BufferedUartRx<'d> {
fn read(&mut self) -> nb::Result<u8, Self::Error> {
embedded_hal_02::serial::Read::read(self)
}
}
impl<'d> embedded_hal_nb::serial::Write for BufferedUartTx<'d> {
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> embedded_hal_nb::serial::Read for BufferedUart<'d> {
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
embedded_hal_02::serial::Read::read(&mut self.rx)
}
}
impl<'d> embedded_hal_nb::serial::Write for BufferedUart<'d> {
fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> {
self.tx.blocking_write(&[char]).map(drop).map_err(nb::Error::Other)
}
fn flush(&mut self) -> nb::Result<(), Self::Error> {
self.tx.blocking_flush().map_err(nb::Error::Other)
}
}