embassy/embassy-stm32/src/usart/mod.rs
2021-12-16 11:37:53 +01:00

690 lines
20 KiB
Rust

#![macro_use]
use core::future::Future;
use core::marker::PhantomData;
use embassy::interrupt::Interrupt;
use embassy::util::Unborrow;
use embassy_hal_common::unborrow;
use futures::TryFutureExt;
use crate::dma::NoDma;
use crate::gpio::sealed::AFType::{OutputOpenDrain, OutputPushPull};
use crate::gpio::Pin;
use crate::pac::usart::{regs, vals};
use crate::rcc::RccPeripheral;
use crate::{dma, peripherals};
#[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,
}
impl Default for Config {
fn default() -> Self {
Self {
baudrate: 115200,
data_bits: DataBits::DataBits8,
stop_bits: StopBits::STOP1,
parity: Parity::ParityNone,
}
}
}
/// 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,
}
pub struct Uart<'d, T: Instance, TxDma = NoDma, RxDma = NoDma> {
inner: T,
phantom: PhantomData<&'d mut T>,
tx_dma: TxDma,
rx_dma: RxDma,
}
impl<'d, T: Instance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
pub fn new(
inner: impl Unborrow<Target = T>,
rx: impl Unborrow<Target = impl RxPin<T>>,
tx: impl Unborrow<Target = impl TxPin<T>>,
tx_dma: impl Unborrow<Target = TxDma>,
rx_dma: impl Unborrow<Target = RxDma>,
config: Config,
) -> Self {
unborrow!(inner, rx, tx, tx_dma, rx_dma);
T::enable();
let pclk_freq = T::frequency();
// TODO: better calculation, including error checking and OVER8 if possible.
let div = (pclk_freq.0 + (config.baudrate / 2)) / config.baudrate;
let r = inner.regs();
unsafe {
rx.set_as_af(rx.af_num(), OutputOpenDrain);
tx.set_as_af(tx.af_num(), OutputPushPull);
r.cr2().write(|_w| {});
r.cr3().write(|_w| {});
r.brr().write_value(regs::Brr(div));
r.cr1().write(|w| {
w.set_ue(true);
w.set_te(true);
w.set_re(true);
w.set_m0(vals::M0::BIT8);
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,
});
});
}
Self {
inner,
phantom: PhantomData,
tx_dma,
rx_dma,
}
}
async fn write_dma(&mut self, buffer: &[u8]) -> Result<(), Error>
where
TxDma: crate::usart::TxDma<T>,
{
let ch = &mut self.tx_dma;
let request = ch.request();
unsafe {
self.inner.regs().cr3().modify(|reg| {
reg.set_dmat(true);
});
}
let r = self.inner.regs();
let dst = tdr(r);
crate::dma::write(ch, request, buffer, dst).await;
Ok(())
}
async fn read_dma(&mut self, buffer: &mut [u8]) -> Result<(), Error>
where
RxDma: crate::usart::RxDma<T>,
{
let ch = &mut self.rx_dma;
let request = ch.request();
unsafe {
self.inner.regs().cr3().modify(|reg| {
reg.set_dmar(true);
});
}
let r = self.inner.regs();
let src = rdr(r);
crate::dma::read(ch, request, src, buffer).await;
Ok(())
}
pub fn read_blocking(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
unsafe {
let r = self.inner.regs();
for b in buffer {
loop {
let sr = sr(r).read();
if sr.pe() {
rdr(r).read_volatile();
return Err(Error::Parity);
} else if sr.fe() {
rdr(r).read_volatile();
return Err(Error::Framing);
} else if sr.ne() {
rdr(r).read_volatile();
return Err(Error::Noise);
} else if sr.ore() {
rdr(r).read_volatile();
return Err(Error::Overrun);
} else if sr.rxne() {
break;
}
}
*b = rdr(r).read_volatile();
}
}
Ok(())
}
}
impl<'d, T: Instance, RxDma> embedded_hal::blocking::serial::Write<u8>
for Uart<'d, T, NoDma, RxDma>
{
type Error = Error;
fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
unsafe {
let r = self.inner.regs();
for &b in buffer {
while !sr(r).read().txe() {}
tdr(r).write_volatile(b);
}
}
Ok(())
}
fn bflush(&mut self) -> Result<(), Self::Error> {
unsafe {
let r = self.inner.regs();
while !sr(r).read().tc() {}
}
Ok(())
}
}
impl<'d, T: Instance, TxDma, RxDma> embassy_traits::uart::Write for Uart<'d, T, TxDma, RxDma>
where
TxDma: crate::usart::TxDma<T>,
{
type WriteFuture<'a>
where
Self: 'a,
= impl Future<Output = Result<(), embassy_traits::uart::Error>> + 'a;
fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a> {
self.write_dma(buf)
.map_err(|_| embassy_traits::uart::Error::Other)
}
}
impl<'d, T: Instance, TxDma, RxDma> embassy_traits::uart::Read for Uart<'d, T, TxDma, RxDma>
where
RxDma: crate::usart::RxDma<T>,
{
type ReadFuture<'a>
where
Self: 'a,
= impl Future<Output = Result<(), embassy_traits::uart::Error>> + 'a;
fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
self.read_dma(buf)
.map_err(|_| embassy_traits::uart::Error::Other)
}
}
#[cfg(usart_v2)]
pub use buffered::*;
#[cfg(usart_v2)]
mod buffered {
use atomic_polyfill::{compiler_fence, Ordering};
use core::pin::Pin;
use core::task::Context;
use core::task::Poll;
use embassy::waitqueue::WakerRegistration;
use embassy_hal_common::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
use embassy_hal_common::ring_buffer::RingBuffer;
use super::*;
pub struct State<'d, T: Instance>(StateStorage<StateInner<'d, T>>);
impl<'d, T: Instance> State<'d, T> {
pub fn new() -> Self {
Self(StateStorage::new())
}
}
struct StateInner<'d, T: Instance> {
uart: Uart<'d, T, NoDma, NoDma>,
phantom: PhantomData<&'d mut T>,
rx_waker: WakerRegistration,
rx: RingBuffer<'d>,
tx_waker: WakerRegistration,
tx: RingBuffer<'d>,
}
unsafe impl<'d, T: Instance> Send for StateInner<'d, T> {}
unsafe impl<'d, T: Instance> Sync for StateInner<'d, T> {}
pub struct BufferedUart<'d, T: Instance> {
inner: PeripheralMutex<'d, StateInner<'d, T>>,
}
impl<'d, T: Instance> Unpin for BufferedUart<'d, T> {}
impl<'d, T: Instance> BufferedUart<'d, T> {
pub unsafe fn new(
state: &'d mut State<'d, T>,
uart: Uart<'d, T, NoDma, NoDma>,
irq: impl Unborrow<Target = T::Interrupt> + 'd,
tx_buffer: &'d mut [u8],
rx_buffer: &'d mut [u8],
) -> BufferedUart<'d, T> {
unborrow!(irq);
let r = uart.inner.regs();
r.cr1().modify(|w| {
w.set_rxneie(true);
w.set_idleie(true);
});
Self {
inner: PeripheralMutex::new_unchecked(irq, &mut state.0, move || StateInner {
uart,
phantom: PhantomData,
tx: RingBuffer::new(tx_buffer),
tx_waker: WakerRegistration::new(),
rx: RingBuffer::new(rx_buffer),
rx_waker: WakerRegistration::new(),
}),
}
}
}
impl<'d, T: Instance> StateInner<'d, T>
where
Self: 'd,
{
fn on_rx(&mut self) {
let r = self.uart.inner.regs();
unsafe {
let sr = r.isr().read();
if sr.pe() {
r.icr().write(|w| {
w.set_pe(true);
});
trace!("Parity error");
} else if sr.fe() {
r.icr().write(|w| {
w.set_fe(true);
});
trace!("Framing error");
} else if sr.ne() {
r.icr().write(|w| {
w.set_ne(true);
});
trace!("Noise error");
} else if sr.ore() {
r.icr().write(|w| {
w.set_ore(true);
});
trace!("Overrun error");
} else if sr.rxne() {
let buf = self.rx.push_buf();
if buf.is_empty() {
self.rx_waker.wake();
} else {
buf[0] = r.rdr().read().0 as u8;
self.rx.push(1);
}
} else if sr.idle() {
r.icr().write(|w| {
w.set_idle(true);
});
self.rx_waker.wake();
};
}
}
fn on_tx(&mut self) {
let r = self.uart.inner.regs();
unsafe {
if r.isr().read().txe() {
let buf = self.tx.pop_buf();
if !buf.is_empty() {
r.cr1().modify(|w| {
w.set_txeie(true);
});
r.tdr().write_value(regs::Dr(buf[0].into()));
self.tx.pop(1);
self.tx_waker.wake();
} else {
// Disable interrupt until we have something to transmit again
r.cr1().modify(|w| {
w.set_txeie(false);
});
}
}
}
}
}
impl<'d, T: Instance> PeripheralState for StateInner<'d, T>
where
Self: 'd,
{
type Interrupt = T::Interrupt;
fn on_interrupt(&mut self) {
self.on_rx();
self.on_tx();
}
}
impl<'d, T: Instance> embassy::io::AsyncBufRead for BufferedUart<'d, T> {
fn poll_fill_buf(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<&[u8], embassy::io::Error>> {
self.inner.with(|state| {
compiler_fence(Ordering::SeqCst);
// We have data ready in buffer? Return it.
let buf = state.rx.pop_buf();
if !buf.is_empty() {
let buf: &[u8] = buf;
// Safety: buffer lives as long as uart
let buf: &[u8] = unsafe { core::mem::transmute(buf) };
return Poll::Ready(Ok(buf));
}
state.rx_waker.register(cx.waker());
Poll::<Result<&[u8], embassy::io::Error>>::Pending
})
}
fn consume(mut self: Pin<&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, T: Instance> embassy::io::AsyncWrite for BufferedUart<'d, T> {
fn poll_write(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, embassy::io::Error>> {
let (poll, empty) = self.inner.with(|state| {
let empty = state.tx.is_empty();
let tx_buf = state.tx.push_buf();
if tx_buf.is_empty() {
state.tx_waker.register(cx.waker());
return (Poll::Pending, empty);
}
let n = core::cmp::min(tx_buf.len(), buf.len());
tx_buf[..n].copy_from_slice(&buf[..n]);
state.tx.push(n);
(Poll::Ready(Ok(n)), empty)
});
if empty {
self.inner.pend();
}
poll
}
fn poll_flush(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), embassy::io::Error>> {
self.inner.with(|state| {
if !state.tx.is_empty() {
state.tx_waker.register(cx.waker());
return Poll::Pending;
}
Poll::Ready(Ok(()))
})
}
}
}
#[cfg(usart_v1)]
fn tdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.dr().ptr() as _
}
#[cfg(usart_v1)]
fn rdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.dr().ptr() as _
}
#[cfg(usart_v1)]
fn sr(r: crate::pac::usart::Usart) -> crate::pac::common::Reg<regs::Sr, crate::pac::common::RW> {
r.sr()
}
#[cfg(usart_v2)]
fn tdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.tdr().ptr() as _
}
#[cfg(usart_v2)]
fn rdr(r: crate::pac::usart::Usart) -> *mut u8 {
r.rdr().ptr() as _
}
#[cfg(usart_v2)]
fn sr(r: crate::pac::usart::Usart) -> crate::pac::common::Reg<regs::Ixr, crate::pac::common::R> {
r.isr()
}
pub(crate) mod sealed {
use super::*;
pub trait Instance {
fn regs(&self) -> crate::pac::usart::Usart;
}
pub trait RxPin<T: Instance>: Pin {
fn af_num(&self) -> u8;
}
pub trait TxPin<T: Instance>: Pin {
fn af_num(&self) -> u8;
}
pub trait CtsPin<T: Instance>: Pin {
fn af_num(&self) -> u8;
}
pub trait RtsPin<T: Instance>: Pin {
fn af_num(&self) -> u8;
}
pub trait CkPin<T: Instance>: Pin {
fn af_num(&self) -> u8;
}
pub trait RxDma<T: Instance> {
fn request(&self) -> dma::Request;
}
pub trait TxDma<T: Instance> {
fn request(&self) -> dma::Request;
}
}
pub trait Instance: sealed::Instance + RccPeripheral {
type Interrupt: Interrupt;
}
pub trait RxPin<T: Instance>: sealed::RxPin<T> {}
pub trait TxPin<T: Instance>: sealed::TxPin<T> {}
pub trait CtsPin<T: Instance>: sealed::CtsPin<T> {}
pub trait RtsPin<T: Instance>: sealed::RtsPin<T> {}
pub trait CkPin<T: Instance>: sealed::CkPin<T> {}
pub trait RxDma<T: Instance>: sealed::RxDma<T> + dma::Channel {}
pub trait TxDma<T: Instance>: sealed::TxDma<T> + dma::Channel {}
crate::pac::interrupts!(
($inst:ident, usart, $block:ident, $signal_name:ident, $irq:ident) => {
impl sealed::Instance for peripherals::$inst {
fn regs(&self) -> crate::pac::usart::Usart {
crate::pac::$inst
}
}
impl Instance for peripherals::$inst {
type Interrupt = crate::interrupt::$irq;
}
};
);
macro_rules! impl_pin {
($inst:ident, $pin:ident, $signal:ident, $af:expr) => {
impl sealed::$signal<peripherals::$inst> for peripherals::$pin {
fn af_num(&self) -> u8 {
$af
}
}
impl $signal<peripherals::$inst> for peripherals::$pin {}
};
}
#[cfg(not(rcc_f1))]
crate::pac::peripheral_pins!(
// USART
($inst:ident, usart, USART, $pin:ident, TX, $af:expr) => {
impl_pin!($inst, $pin, TxPin, $af);
};
($inst:ident, usart, USART, $pin:ident, RX, $af:expr) => {
impl_pin!($inst, $pin, RxPin, $af);
};
($inst:ident, usart, USART, $pin:ident, CTS, $af:expr) => {
impl_pin!($inst, $pin, CtsPin, $af);
};
($inst:ident, usart, USART, $pin:ident, RTS, $af:expr) => {
impl_pin!($inst, $pin, RtsPin, $af);
};
($inst:ident, usart, USART, $pin:ident, CK, $af:expr) => {
impl_pin!($inst, $pin, CkPin, $af);
};
// UART
($inst:ident, uart, UART, $pin:ident, TX, $af:expr) => {
impl_pin!($inst, $pin, TxPin, $af);
};
($inst:ident, uart, UART, $pin:ident, RX, $af:expr) => {
impl_pin!($inst, $pin, RxPin, $af);
};
($inst:ident, uart, UART, $pin:ident, CTS, $af:expr) => {
impl_pin!($inst, $pin, CtsPin, $af);
};
($inst:ident, uart, UART, $pin:ident, RTS, $af:expr) => {
impl_pin!($inst, $pin, RtsPin, $af);
};
($inst:ident, uart, UART, $pin:ident, CK, $af:expr) => {
impl_pin!($inst, $pin, CkPin, $af);
};
);
#[cfg(rcc_f1)]
crate::pac::peripheral_pins!(
// USART
($inst:ident, usart, USART, $pin:ident, TX) => {
impl_pin!($inst, $pin, TxPin, 0);
};
($inst:ident, usart, USART, $pin:ident, RX) => {
impl_pin!($inst, $pin, RxPin, 0);
};
($inst:ident, usart, USART, $pin:ident, CTS) => {
impl_pin!($inst, $pin, CtsPin, 0);
};
($inst:ident, usart, USART, $pin:ident, RTS) => {
impl_pin!($inst, $pin, RtsPin, 0);
};
($inst:ident, usart, USART, $pin:ident, CK) => {
impl_pin!($inst, $pin, CkPin, 0);
};
// UART
($inst:ident, uart, UART, $pin:ident, TX) => {
impl_pin!($inst, $pin, TxPin, 0);
};
($inst:ident, uart, UART, $pin:ident, RX) => {
impl_pin!($inst, $pin, RxPin, 0);
};
($inst:ident, uart, UART, $pin:ident, CTS) => {
impl_pin!($inst, $pin, CtsPin, 0);
};
($inst:ident, uart, UART, $pin:ident, RTS) => {
impl_pin!($inst, $pin, RtsPin, 0);
};
($inst:ident, uart, UART, $pin:ident, CK) => {
impl_pin!($inst, $pin, CkPin, 0);
};
);
#[allow(unused)]
macro_rules! impl_dma {
($inst:ident, {dmamux: $dmamux:ident}, $signal:ident, $request:expr) => {
impl<T> sealed::$signal<peripherals::$inst> for T
where
T: crate::dma::MuxChannel<Mux = crate::dma::$dmamux>,
{
fn request(&self) -> dma::Request {
$request
}
}
impl<T> $signal<peripherals::$inst> for T where
T: crate::dma::MuxChannel<Mux = crate::dma::$dmamux>
{
}
};
($inst:ident, {channel: $channel:ident}, $signal:ident, $request:expr) => {
impl sealed::$signal<peripherals::$inst> for peripherals::$channel {
fn request(&self) -> dma::Request {
$request
}
}
impl $signal<peripherals::$inst> for peripherals::$channel {}
};
}
crate::pac::peripheral_dma_channels! {
($peri:ident, usart, $kind:ident, RX, $channel:tt, $request:expr) => {
impl_dma!($peri, $channel, RxDma, $request);
};
($peri:ident, usart, $kind:ident, TX, $channel:tt, $request:expr) => {
impl_dma!($peri, $channel, TxDma, $request);
};
($peri:ident, uart, $kind:ident, RX, $channel:tt, $request:expr) => {
impl_dma!($peri, $channel, RxDma, $request);
};
($peri:ident, uart, $kind:ident, TX, $channel:tt, $request:expr) => {
impl_dma!($peri, $channel, TxDma, $request);
};
}