embassy/embassy-stm32/src/usart/mod.rs
2023-06-19 03:22:12 +02:00

1207 lines
36 KiB
Rust

#![macro_use]
use core::future::poll_fn;
use core::marker::PhantomData;
use core::sync::atomic::{compiler_fence, Ordering};
use core::task::Poll;
use embassy_hal_common::drop::OnDrop;
use embassy_hal_common::{into_ref, PeripheralRef};
use futures::future::{select, Either};
use crate::dma::{NoDma, Transfer};
use crate::gpio::sealed::AFType;
use crate::interrupt::typelevel::Interrupt;
#[cfg(not(any(usart_v1, usart_v2)))]
#[allow(unused_imports)]
use crate::pac::usart::regs::Isr as Sr;
#[cfg(any(usart_v1, usart_v2))]
#[allow(unused_imports)]
use crate::pac::usart::regs::Sr;
#[cfg(not(any(usart_v1, usart_v2)))]
use crate::pac::usart::Lpuart as Regs;
#[cfg(any(usart_v1, usart_v2))]
use crate::pac::usart::Usart as Regs;
use crate::pac::usart::{regs, vals};
use crate::time::Hertz;
use crate::{interrupt, peripherals, Peripheral};
/// Interrupt handler.
pub struct InterruptHandler<T: BasicInstance> {
_phantom: PhantomData<T>,
}
impl<T: BasicInstance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
unsafe fn on_interrupt() {
let r = T::regs();
let s = T::state();
let (sr, cr1, cr3) = (sr(r).read(), r.cr1().read(), r.cr3().read());
let has_errors = (sr.pe() && cr1.peie()) || ((sr.fe() || sr.ne() || sr.ore()) && cr3.eie());
if has_errors {
// clear all interrupts and DMA Rx Request
r.cr1().modify(|w| {
// disable RXNE interrupt
w.set_rxneie(false);
// disable parity interrupt
w.set_peie(false);
// disable idle line interrupt
w.set_idleie(false);
});
r.cr3().modify(|w| {
// disable Error Interrupt: (Frame error, Noise error, Overrun error)
w.set_eie(false);
// disable DMA Rx Request
w.set_dmar(false);
});
} else if cr1.idleie() && sr.idle() {
// IDLE detected: no more data will come
r.cr1().modify(|w| {
// disable idle line detection
w.set_idleie(false);
});
} else if cr1.rxneie() {
// We cannot check the RXNE flag as it is auto-cleared by the DMA controller
// It is up to the listener to determine if this in fact was a RX event and disable the RXNE detection
} else {
return;
}
compiler_fence(Ordering::SeqCst);
s.rx_waker.wake();
}
}
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum DataBits {
DataBits8,
DataBits9,
}
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum Parity {
ParityNone,
ParityEven,
ParityOdd,
}
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum StopBits {
#[doc = "1 stop bit"]
STOP1,
#[doc = "0.5 stop bits"]
STOP0P5,
#[doc = "2 stop bits"]
STOP2,
#[doc = "1.5 stop bits"]
STOP1P5,
}
#[non_exhaustive]
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub struct Config {
pub baudrate: u32,
pub data_bits: DataBits,
pub stop_bits: StopBits,
pub parity: Parity,
/// if true, on read-like method, if there is a latent error pending,
/// read will abort, the error reported and cleared
/// if false, the error is ignored and cleared
pub detect_previous_overrun: bool,
/// Set this to true if the line is considered noise free.
/// This will increase the receivers tolerance to clock deviations,
/// but will effectively disable noise detection.
#[cfg(not(usart_v1))]
pub assume_noise_free: bool,
}
impl Default for Config {
fn default() -> Self {
Self {
baudrate: 115200,
data_bits: DataBits::DataBits8,
stop_bits: StopBits::STOP1,
parity: Parity::ParityNone,
// historical behavior
detect_previous_overrun: false,
#[cfg(not(usart_v1))]
assume_noise_free: false,
}
}
}
/// Serial error
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
#[non_exhaustive]
pub enum Error {
/// Framing error
Framing,
/// Noise error
Noise,
/// RX buffer overrun
Overrun,
/// Parity check error
Parity,
/// Buffer too large for DMA
BufferTooLong,
}
enum ReadCompletionEvent {
// DMA Read transfer completed first
DmaCompleted,
// Idle line detected first
Idle(usize),
}
pub struct Uart<'d, T: BasicInstance, TxDma = NoDma, RxDma = NoDma> {
tx: UartTx<'d, T, TxDma>,
rx: UartRx<'d, T, RxDma>,
}
pub struct UartTx<'d, T: BasicInstance, TxDma = NoDma> {
phantom: PhantomData<&'d mut T>,
tx_dma: PeripheralRef<'d, TxDma>,
}
pub struct UartRx<'d, T: BasicInstance, RxDma = NoDma> {
_peri: PeripheralRef<'d, T>,
rx_dma: PeripheralRef<'d, RxDma>,
detect_previous_overrun: bool,
#[cfg(any(usart_v1, usart_v2))]
buffered_sr: stm32_metapac::usart::regs::Sr,
}
impl<'d, T: BasicInstance, TxDma> UartTx<'d, T, TxDma> {
/// Useful if you only want Uart Tx. It saves 1 pin and consumes a little less power.
pub fn new(
peri: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
config: Config,
) -> Self {
T::enable();
T::reset();
Self::new_inner(peri, tx, tx_dma, config)
}
pub fn new_with_cts(
peri: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
config: Config,
) -> Self {
into_ref!(cts);
T::enable();
T::reset();
cts.set_as_af(cts.af_num(), AFType::Input);
T::regs().cr3().write(|w| {
w.set_ctse(true);
});
Self::new_inner(peri, tx, tx_dma, config)
}
fn new_inner(
_peri: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
config: Config,
) -> Self {
into_ref!(_peri, tx, tx_dma);
let r = T::regs();
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
configure(r, &config, T::frequency(), T::KIND, false, true);
// create state once!
let _s = T::state();
Self {
tx_dma,
phantom: PhantomData,
}
}
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error>
where
TxDma: crate::usart::TxDma<T>,
{
let ch = &mut self.tx_dma;
let request = ch.request();
T::regs().cr3().modify(|reg| {
reg.set_dmat(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.
let transfer = unsafe { Transfer::new_write(ch, request, buffer, tdr(T::regs()), Default::default()) };
transfer.await;
Ok(())
}
pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
let r = T::regs();
for &b in buffer {
while !sr(r).read().txe() {}
unsafe { tdr(r).write_volatile(b) };
}
Ok(())
}
pub fn blocking_flush(&mut self) -> Result<(), Error> {
let r = T::regs();
while !sr(r).read().tc() {}
Ok(())
}
}
impl<'d, T: BasicInstance, RxDma> UartRx<'d, T, RxDma> {
/// Useful if you only want Uart Rx. It saves 1 pin and consumes a little less power.
pub fn new(
peri: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
T::enable();
T::reset();
Self::new_inner(peri, rx, rx_dma, config)
}
pub fn new_with_rts(
peri: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
into_ref!(rts);
T::enable();
T::reset();
rts.set_as_af(rts.af_num(), AFType::OutputPushPull);
T::regs().cr3().write(|w| {
w.set_rtse(true);
});
Self::new_inner(peri, rx, rx_dma, config)
}
fn new_inner(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
into_ref!(peri, rx, rx_dma);
let r = T::regs();
rx.set_as_af(rx.af_num(), AFType::Input);
configure(r, &config, T::frequency(), T::KIND, true, false);
T::Interrupt::unpend();
unsafe { T::Interrupt::enable() };
// create state once!
let _s = T::state();
Self {
_peri: peri,
rx_dma,
detect_previous_overrun: config.detect_previous_overrun,
#[cfg(any(usart_v1, usart_v2))]
buffered_sr: stm32_metapac::usart::regs::Sr(0),
}
}
#[cfg(any(usart_v1, usart_v2))]
fn check_rx_flags(&mut self) -> Result<bool, Error> {
let r = T::regs();
loop {
// Handle all buffered error flags.
if self.buffered_sr.pe() {
self.buffered_sr.set_pe(false);
return Err(Error::Parity);
} else if self.buffered_sr.fe() {
self.buffered_sr.set_fe(false);
return Err(Error::Framing);
} else if self.buffered_sr.ne() {
self.buffered_sr.set_ne(false);
return Err(Error::Noise);
} else if self.buffered_sr.ore() {
self.buffered_sr.set_ore(false);
return Err(Error::Overrun);
} else if self.buffered_sr.rxne() {
self.buffered_sr.set_rxne(false);
return Ok(true);
} else {
// No error flags from previous iterations were set: Check the actual status register
let sr = r.sr().read();
if !sr.rxne() {
return Ok(false);
}
// Buffer the status register and let the loop handle the error flags.
self.buffered_sr = sr;
}
}
}
#[cfg(any(usart_v3, usart_v4))]
fn check_rx_flags(&mut self) -> Result<bool, Error> {
let r = T::regs();
let sr = r.isr().read();
if sr.pe() {
r.icr().write(|w| w.set_pe(true));
return Err(Error::Parity);
} else if sr.fe() {
r.icr().write(|w| w.set_fe(true));
return Err(Error::Framing);
} else if sr.ne() {
r.icr().write(|w| w.set_ne(true));
return Err(Error::Noise);
} else if sr.ore() {
r.icr().write(|w| w.set_ore(true));
return Err(Error::Overrun);
}
Ok(sr.rxne())
}
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error>
where
RxDma: crate::usart::RxDma<T>,
{
self.inner_read(buffer, false).await?;
Ok(())
}
pub fn nb_read(&mut self) -> Result<u8, nb::Error<Error>> {
let r = T::regs();
if self.check_rx_flags()? {
Ok(unsafe { rdr(r).read_volatile() })
} else {
Err(nb::Error::WouldBlock)
}
}
pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
let r = T::regs();
for b in buffer {
while !self.check_rx_flags()? {}
unsafe { *b = rdr(r).read_volatile() }
}
Ok(())
}
pub async fn read_until_idle(&mut self, buffer: &mut [u8]) -> Result<usize, Error>
where
RxDma: crate::usart::RxDma<T>,
{
self.inner_read(buffer, true).await
}
async fn inner_read_run(
&mut self,
buffer: &mut [u8],
enable_idle_line_detection: bool,
) -> Result<ReadCompletionEvent, Error>
where
RxDma: crate::usart::RxDma<T>,
{
let r = T::regs();
// make sure USART state is restored to neutral state when this future is dropped
let on_drop = OnDrop::new(move || {
// defmt::trace!("Clear all USART interrupts and DMA Read Request");
// clear all interrupts and DMA Rx Request
r.cr1().modify(|w| {
// disable RXNE interrupt
w.set_rxneie(false);
// disable parity interrupt
w.set_peie(false);
// disable idle line interrupt
w.set_idleie(false);
});
r.cr3().modify(|w| {
// disable Error Interrupt: (Frame error, Noise error, Overrun error)
w.set_eie(false);
// disable DMA Rx Request
w.set_dmar(false);
});
});
let ch = &mut self.rx_dma;
let request = ch.request();
let buffer_len = buffer.len();
// Start USART DMA
// will not do anything yet because DMAR is not yet set
// future which will complete when DMA Read request completes
let transfer = unsafe { Transfer::new_read(ch, request, rdr(T::regs()), buffer, Default::default()) };
// clear ORE flag just before enabling DMA Rx Request: can be mandatory for the second transfer
if !self.detect_previous_overrun {
let sr = sr(r).read();
// This read also clears the error and idle interrupt flags on v1.
unsafe { rdr(r).read_volatile() };
clear_interrupt_flags(r, sr);
}
r.cr1().modify(|w| {
// disable RXNE interrupt
w.set_rxneie(false);
// enable parity interrupt if not ParityNone
w.set_peie(w.pce());
});
r.cr3().modify(|w| {
// enable Error Interrupt: (Frame error, Noise error, Overrun error)
w.set_eie(true);
// enable DMA Rx Request
w.set_dmar(true);
});
compiler_fence(Ordering::SeqCst);
// In case of errors already pending when reception started, interrupts may have already been raised
// and lead to reception abortion (Overrun error for instance). In such a case, all interrupts
// have been disabled in interrupt handler and DMA Rx Request has been disabled.
let cr3 = r.cr3().read();
if !cr3.dmar() {
// something went wrong
// because the only way to get this flag cleared is to have an interrupt
// DMA will be stopped when transfer is dropped
let sr = sr(r).read();
// This read also clears the error and idle interrupt flags on v1.
unsafe { rdr(r).read_volatile() };
clear_interrupt_flags(r, sr);
if sr.pe() {
return Err(Error::Parity);
}
if sr.fe() {
return Err(Error::Framing);
}
if sr.ne() {
return Err(Error::Noise);
}
if sr.ore() {
return Err(Error::Overrun);
}
unreachable!();
}
if enable_idle_line_detection {
// clear idle flag
let sr = sr(r).read();
// This read also clears the error and idle interrupt flags on v1.
unsafe { rdr(r).read_volatile() };
clear_interrupt_flags(r, sr);
// enable idle interrupt
r.cr1().modify(|w| {
w.set_idleie(true);
});
}
compiler_fence(Ordering::SeqCst);
// future which completes when idle line or error is detected
let abort = poll_fn(move |cx| {
let s = T::state();
s.rx_waker.register(cx.waker());
let sr = sr(r).read();
// This read also clears the error and idle interrupt flags on v1.
unsafe { rdr(r).read_volatile() };
clear_interrupt_flags(r, sr);
compiler_fence(Ordering::SeqCst);
let has_errors = sr.pe() || sr.fe() || sr.ne() || sr.ore();
if has_errors {
// all Rx interrupts and Rx DMA Request have already been cleared in interrupt handler
if sr.pe() {
return Poll::Ready(Err(Error::Parity));
}
if sr.fe() {
return Poll::Ready(Err(Error::Framing));
}
if sr.ne() {
return Poll::Ready(Err(Error::Noise));
}
if sr.ore() {
return Poll::Ready(Err(Error::Overrun));
}
}
if enable_idle_line_detection && sr.idle() {
// Idle line detected
return Poll::Ready(Ok(()));
}
Poll::Pending
});
// wait for the first of DMA request or idle line detected to completes
// select consumes its arguments
// when transfer is dropped, it will stop the DMA request
let r = match select(transfer, abort).await {
// DMA transfer completed first
Either::Left(((), _)) => Ok(ReadCompletionEvent::DmaCompleted),
// Idle line detected first
Either::Right((Ok(()), transfer)) => Ok(ReadCompletionEvent::Idle(
buffer_len - transfer.get_remaining_transfers() as usize,
)),
// error occurred
Either::Right((Err(e), _)) => Err(e),
};
drop(on_drop);
r
}
async fn inner_read(&mut self, buffer: &mut [u8], enable_idle_line_detection: bool) -> Result<usize, Error>
where
RxDma: crate::usart::RxDma<T>,
{
if buffer.is_empty() {
return Ok(0);
} else if buffer.len() > 0xFFFF {
return Err(Error::BufferTooLong);
}
let buffer_len = buffer.len();
// wait for DMA to complete or IDLE line detection if requested
let res = self.inner_read_run(buffer, enable_idle_line_detection).await;
match res {
Ok(ReadCompletionEvent::DmaCompleted) => Ok(buffer_len),
Ok(ReadCompletionEvent::Idle(n)) => Ok(n),
Err(e) => Err(e),
}
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
pub fn new(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
T::enable();
T::reset();
Self::new_inner(peri, rx, tx, tx_dma, rx_dma, config)
}
pub fn new_with_rtscts(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
into_ref!(cts, rts);
T::enable();
T::reset();
rts.set_as_af(rts.af_num(), AFType::OutputPushPull);
cts.set_as_af(cts.af_num(), AFType::Input);
T::regs().cr3().write(|w| {
w.set_rtse(true);
w.set_ctse(true);
});
Self::new_inner(peri, rx, tx, tx_dma, rx_dma, config)
}
#[cfg(not(any(usart_v1, usart_v2)))]
pub fn new_with_de(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
de: impl Peripheral<P = impl DePin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
into_ref!(de);
T::enable();
T::reset();
de.set_as_af(de.af_num(), AFType::OutputPushPull);
T::regs().cr3().write(|w| {
w.set_dem(true);
});
Self::new_inner(peri, rx, tx, tx_dma, rx_dma, config)
}
fn new_inner(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_dma: impl Peripheral<P = TxDma> + 'd,
rx_dma: impl Peripheral<P = RxDma> + 'd,
config: Config,
) -> Self {
into_ref!(peri, rx, tx, tx_dma, rx_dma);
let r = T::regs();
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
configure(r, &config, T::frequency(), T::KIND, true, true);
T::Interrupt::unpend();
unsafe { T::Interrupt::enable() };
// create state once!
let _s = T::state();
Self {
tx: UartTx {
tx_dma,
phantom: PhantomData,
},
rx: UartRx {
_peri: peri,
rx_dma,
detect_previous_overrun: config.detect_previous_overrun,
#[cfg(any(usart_v1, usart_v2))]
buffered_sr: stm32_metapac::usart::regs::Sr(0),
},
}
}
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error>
where
TxDma: crate::usart::TxDma<T>,
{
self.tx.write(buffer).await
}
pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
self.tx.blocking_write(buffer)
}
pub fn blocking_flush(&mut self) -> Result<(), Error> {
self.tx.blocking_flush()
}
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error>
where
RxDma: crate::usart::RxDma<T>,
{
self.rx.read(buffer).await
}
pub fn nb_read(&mut self) -> Result<u8, nb::Error<Error>> {
self.rx.nb_read()
}
pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
self.rx.blocking_read(buffer)
}
pub async fn read_until_idle(&mut self, buffer: &mut [u8]) -> Result<usize, Error>
where
RxDma: crate::usart::RxDma<T>,
{
self.rx.read_until_idle(buffer).await
}
/// Split the Uart into a transmitter and receiver, which is
/// particularly useful when having two tasks correlating to
/// transmitting and receiving.
pub fn split(self) -> (UartTx<'d, T, TxDma>, UartRx<'d, T, RxDma>) {
(self.tx, self.rx)
}
}
fn configure(r: Regs, config: &Config, pclk_freq: Hertz, kind: Kind, enable_rx: bool, enable_tx: bool) {
if !enable_rx && !enable_tx {
panic!("USART: At least one of RX or TX should be enabled");
}
#[cfg(not(usart_v4))]
static DIVS: [(u16, ()); 1] = [(1, ())];
#[cfg(usart_v4)]
static DIVS: [(u16, vals::Presc); 12] = [
(1, vals::Presc::DIV1),
(2, vals::Presc::DIV2),
(4, vals::Presc::DIV4),
(6, vals::Presc::DIV6),
(8, vals::Presc::DIV8),
(10, vals::Presc::DIV10),
(12, vals::Presc::DIV12),
(16, vals::Presc::DIV16),
(32, vals::Presc::DIV32),
(64, vals::Presc::DIV64),
(128, vals::Presc::DIV128),
(256, vals::Presc::DIV256),
];
let (mul, brr_min, brr_max) = match kind {
#[cfg(any(usart_v3, usart_v4))]
Kind::Lpuart => (256, 0x300, 0x10_0000),
Kind::Uart => (1, 0x10, 0x1_0000),
};
#[cfg(not(usart_v1))]
let mut over8 = false;
let mut found = None;
for &(presc, _presc_val) in &DIVS {
let denom = (config.baudrate * presc as u32) as u64;
let div = (pclk_freq.0 as u64 * mul + (denom / 2)) / denom;
trace!(
"USART: presc={}, div=0x{:08x} (mantissa = {}, fraction = {})",
presc,
div,
div >> 4,
div & 0x0F
);
if div < brr_min {
#[cfg(not(usart_v1))]
if div * 2 >= brr_min && kind == Kind::Uart && !cfg!(usart_v1) {
over8 = true;
let div = div as u32;
r.brr().write_value(regs::Brr(((div << 1) & !0xF) | (div & 0x07)));
#[cfg(usart_v4)]
r.presc().write(|w| w.set_prescaler(_presc_val));
found = Some(div);
break;
}
panic!("USART: baudrate too high");
}
if div < brr_max {
let div = div as u32;
r.brr().write_value(regs::Brr(div));
#[cfg(usart_v4)]
r.presc().write(|w| w.set_prescaler(_presc_val));
found = Some(div);
break;
}
}
let div = found.expect("USART: baudrate too low");
#[cfg(not(usart_v1))]
let oversampling = if over8 { "8 bit" } else { "16 bit" };
#[cfg(usart_v1)]
let oversampling = "default";
trace!(
"Using {} oversampling, desired baudrate: {}, actual baudrate: {}",
oversampling,
config.baudrate,
pclk_freq.0 / div
);
r.cr2().write(|w| {
w.set_stop(match config.stop_bits {
StopBits::STOP0P5 => vals::Stop::STOP0P5,
StopBits::STOP1 => vals::Stop::STOP1,
StopBits::STOP1P5 => vals::Stop::STOP1P5,
StopBits::STOP2 => vals::Stop::STOP2,
});
});
r.cr1().write(|w| {
// enable uart
w.set_ue(true);
// enable transceiver
w.set_te(enable_tx);
// enable receiver
w.set_re(enable_rx);
// configure word size
w.set_m0(if config.parity != Parity::ParityNone {
vals::M0::BIT9
} else {
vals::M0::BIT8
});
// configure parity
w.set_pce(config.parity != Parity::ParityNone);
w.set_ps(match config.parity {
Parity::ParityOdd => vals::Ps::ODD,
Parity::ParityEven => vals::Ps::EVEN,
_ => vals::Ps::EVEN,
});
#[cfg(not(usart_v1))]
w.set_over8(vals::Over8(over8 as _));
});
#[cfg(not(usart_v1))]
r.cr3().modify(|w| {
w.set_onebit(config.assume_noise_free);
});
}
mod eh02 {
use super::*;
impl<'d, T: BasicInstance, RxDma> embedded_hal_02::serial::Read<u8> for UartRx<'d, T, RxDma> {
type Error = Error;
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
self.nb_read()
}
}
impl<'d, T: BasicInstance, TxDma> embedded_hal_02::blocking::serial::Write<u8> for UartTx<'d, T, TxDma> {
type Error = Error;
fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(buffer)
}
fn bflush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_02::serial::Read<u8> for Uart<'d, T, TxDma, RxDma> {
type Error = Error;
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
self.nb_read()
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_02::blocking::serial::Write<u8> for Uart<'d, T, TxDma, RxDma> {
type Error = Error;
fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(buffer)
}
fn bflush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
}
#[cfg(feature = "unstable-traits")]
mod eh1 {
use super::*;
impl embedded_hal_1::serial::Error for Error {
fn kind(&self) -> embedded_hal_1::serial::ErrorKind {
match *self {
Self::Framing => embedded_hal_1::serial::ErrorKind::FrameFormat,
Self::Noise => embedded_hal_1::serial::ErrorKind::Noise,
Self::Overrun => embedded_hal_1::serial::ErrorKind::Overrun,
Self::Parity => embedded_hal_1::serial::ErrorKind::Parity,
Self::BufferTooLong => embedded_hal_1::serial::ErrorKind::Other,
}
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_1::serial::ErrorType for Uart<'d, T, TxDma, RxDma> {
type Error = Error;
}
impl<'d, T: BasicInstance, TxDma> embedded_hal_1::serial::ErrorType for UartTx<'d, T, TxDma> {
type Error = Error;
}
impl<'d, T: BasicInstance, RxDma> embedded_hal_1::serial::ErrorType for UartRx<'d, T, RxDma> {
type Error = Error;
}
impl<'d, T: BasicInstance, RxDma> embedded_hal_nb::serial::Read for UartRx<'d, T, RxDma> {
fn read(&mut self) -> nb::Result<u8, Self::Error> {
self.nb_read()
}
}
impl<'d, T: BasicInstance, TxDma> embedded_hal_1::serial::Write for UartTx<'d, T, TxDma> {
fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(buffer)
}
fn flush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
impl<'d, T: BasicInstance, TxDma> embedded_hal_nb::serial::Write for UartTx<'d, T, TxDma> {
fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> {
self.blocking_write(&[char]).map_err(nb::Error::Other)
}
fn flush(&mut self) -> nb::Result<(), Self::Error> {
self.blocking_flush().map_err(nb::Error::Other)
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_nb::serial::Read for Uart<'d, T, TxDma, RxDma> {
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
self.nb_read()
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_1::serial::Write for Uart<'d, T, TxDma, RxDma> {
fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(buffer)
}
fn flush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
impl<'d, T: BasicInstance, TxDma, RxDma> embedded_hal_nb::serial::Write for Uart<'d, T, TxDma, RxDma> {
fn write(&mut self, char: u8) -> nb::Result<(), Self::Error> {
self.blocking_write(&[char]).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"))]
mod eio {
use embedded_io::asynch::Write;
use embedded_io::Io;
use super::*;
impl<T, TxDma, RxDma> Io for Uart<'_, T, TxDma, RxDma>
where
T: BasicInstance,
{
type Error = Error;
}
impl<T, TxDma, RxDma> Write for Uart<'_, T, TxDma, RxDma>
where
T: BasicInstance,
TxDma: super::TxDma<T>,
{
async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
self.write(buf).await?;
Ok(buf.len())
}
async fn flush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
impl<T, TxDma> Io for UartTx<'_, T, TxDma>
where
T: BasicInstance,
{
type Error = Error;
}
impl<T, TxDma> Write for UartTx<'_, T, TxDma>
where
T: BasicInstance,
TxDma: super::TxDma<T>,
{
async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
self.write(buf).await?;
Ok(buf.len())
}
async fn flush(&mut self) -> Result<(), Self::Error> {
self.blocking_flush()
}
}
}
#[cfg(feature = "nightly")]
pub use buffered::*;
#[cfg(feature = "nightly")]
pub use crate::usart::buffered::InterruptHandler as BufferedInterruptHandler;
#[cfg(feature = "nightly")]
mod buffered;
#[cfg(not(gpdma))]
mod ringbuffered;
#[cfg(not(gpdma))]
pub use ringbuffered::RingBufferedUartRx;
use self::sealed::Kind;
#[cfg(any(usart_v1, usart_v2))]
fn tdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.dr().as_ptr() as _
}
#[cfg(any(usart_v1, usart_v2))]
fn rdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.dr().as_ptr() as _
}
#[cfg(any(usart_v1, usart_v2))]
fn sr(r: crate::pac::usart::Usart) -> crate::pac::common::Reg<regs::Sr, crate::pac::common::RW> {
r.sr()
}
#[cfg(any(usart_v1, usart_v2))]
#[allow(unused)]
fn clear_interrupt_flags(_r: Regs, _sr: regs::Sr) {
// On v1 the flags are cleared implicitly by reads and writes to DR.
}
#[cfg(any(usart_v3, usart_v4))]
fn tdr(r: Regs) -> *mut u8 {
r.tdr().as_ptr() as _
}
#[cfg(any(usart_v3, usart_v4))]
fn rdr(r: Regs) -> *mut u8 {
r.rdr().as_ptr() as _
}
#[cfg(any(usart_v3, usart_v4))]
fn sr(r: Regs) -> crate::pac::common::Reg<regs::Isr, crate::pac::common::R> {
r.isr()
}
#[cfg(any(usart_v3, usart_v4))]
#[allow(unused)]
fn clear_interrupt_flags(r: Regs, sr: regs::Isr) {
r.icr().write(|w| *w = regs::Icr(sr.0));
}
pub(crate) mod sealed {
use embassy_sync::waitqueue::AtomicWaker;
use super::*;
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum Kind {
Uart,
#[cfg(any(usart_v3, usart_v4))]
Lpuart,
}
pub struct State {
pub rx_waker: AtomicWaker,
pub tx_waker: AtomicWaker,
}
impl State {
pub const fn new() -> Self {
Self {
rx_waker: AtomicWaker::new(),
tx_waker: AtomicWaker::new(),
}
}
}
pub trait BasicInstance: crate::rcc::RccPeripheral {
const KIND: Kind;
type Interrupt: interrupt::typelevel::Interrupt;
fn regs() -> Regs;
fn state() -> &'static State;
#[cfg(feature = "nightly")]
fn buffered_state() -> &'static buffered::State;
}
pub trait FullInstance: BasicInstance {
fn regs_uart() -> crate::pac::usart::Usart;
}
}
pub trait BasicInstance: Peripheral<P = Self> + sealed::BasicInstance + 'static + Send {}
pub trait FullInstance: sealed::FullInstance {}
pin_trait!(RxPin, BasicInstance);
pin_trait!(TxPin, BasicInstance);
pin_trait!(CtsPin, BasicInstance);
pin_trait!(RtsPin, BasicInstance);
pin_trait!(CkPin, BasicInstance);
pin_trait!(DePin, BasicInstance);
dma_trait!(TxDma, BasicInstance);
dma_trait!(RxDma, BasicInstance);
macro_rules! impl_usart {
($inst:ident, $irq:ident, $kind:expr) => {
impl sealed::BasicInstance for crate::peripherals::$inst {
const KIND: Kind = $kind;
type Interrupt = crate::interrupt::typelevel::$irq;
fn regs() -> Regs {
unsafe { Regs::from_ptr(crate::pac::$inst.as_ptr()) }
}
fn state() -> &'static crate::usart::sealed::State {
static STATE: crate::usart::sealed::State = crate::usart::sealed::State::new();
&STATE
}
#[cfg(feature = "nightly")]
fn buffered_state() -> &'static buffered::State {
static STATE: buffered::State = buffered::State::new();
&STATE
}
}
impl BasicInstance for peripherals::$inst {}
};
}
foreach_interrupt!(
($inst:ident, usart, LPUART, $signal_name:ident, $irq:ident) => {
impl_usart!($inst, $irq, Kind::Lpuart);
};
($inst:ident, usart, $block:ident, $signal_name:ident, $irq:ident) => {
impl_usart!($inst, $irq, Kind::Uart);
impl sealed::FullInstance for peripherals::$inst {
fn regs_uart() -> crate::pac::usart::Usart {
crate::pac::$inst
}
}
impl FullInstance for peripherals::$inst {}
};
);