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Merge pull request #3089 from qwerty19106/stm32_uart_half_fix_sequential_read_write

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WIP: STM32 Half-Duplex: fix sequential reads and writes
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Dario Nieuwenhuis 2024-07-02 00:58:54 +00:00 • committed by GitHub
commit d6e4086a15
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GPG key ID: B5690EEEBB952194
1 changed files with 31 additions and 14 deletions
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45
embassy-stm32/src/usart/mod.rs
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@ -371,9 +371,12 @@ impl<'d> UartTx<'d, Async> {
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> { pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
let r = self.info.regs; let r = self.info.regs;
// Disable Receiver for Half-Duplex mode // Enable Transmitter and disable Receiver for Half-Duplex mode
if r.cr3().read().hdsel() { let mut cr1 = r.cr1().read();
r.cr1().modify(|reg| reg.set_re(false)); if r.cr3().read().hdsel() && !cr1.te() {
cr1.set_te(true);
cr1.set_re(false);
r.cr1().write_value(cr1);
} }
let ch = self.tx_dma.as_mut().unwrap(); let ch = self.tx_dma.as_mut().unwrap();
@ -474,9 +477,12 @@ impl<'d, M: Mode> UartTx<'d, M> {
pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> { pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
let r = self.info.regs; let r = self.info.regs;
// Disable Receiver for Half-Duplex mode // Enable Transmitter and disable Receiver for Half-Duplex mode
if r.cr3().read().hdsel() { let mut cr1 = r.cr1().read();
r.cr1().modify(|reg| reg.set_re(false)); if r.cr3().read().hdsel() && !cr1.te() {
cr1.set_te(true);
cr1.set_re(false);
r.cr1().write_value(cr1);
} }
for &b in buffer { for &b in buffer {
@ -561,8 +567,9 @@ impl<'d> UartRx<'d, Async> {
) -> Result<ReadCompletionEvent, Error> { ) -> Result<ReadCompletionEvent, Error> {
let r = self.info.regs; let r = self.info.regs;
// Call flush for Half-Duplex mode. It prevents reading of bytes which have just been written. // Call flush for Half-Duplex mode if some bytes were written and flush was not called.
if r.cr3().read().hdsel() { // It prevents reading of bytes which have just been written.
if r.cr3().read().hdsel() && r.cr1().read().te() {
blocking_flush(self.info)?; blocking_flush(self.info)?;
} }
@ -898,8 +905,9 @@ impl<'d, M: Mode> UartRx<'d, M> {
pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> { pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
let r = self.info.regs; let r = self.info.regs;
// Call flush for Half-Duplex mode. It prevents reading of bytes which have just been written. // Call flush for Half-Duplex mode if some bytes were written and flush was not called.
if r.cr3().read().hdsel() { // It prevents reading of bytes which have just been written.
if r.cr3().read().hdsel() && r.cr1().read().te() {
blocking_flush(self.info)?; blocking_flush(self.info)?;
} }
@ -1481,10 +1489,19 @@ fn configure(
r.cr1().write(|w| { r.cr1().write(|w| {
// enable uart // enable uart
w.set_ue(true); w.set_ue(true);
// enable transceiver
w.set_te(enable_tx); if config.half_duplex {
// enable receiver // The te and re bits will be set by write, read and flush methods.
w.set_re(enable_rx); // Receiver should be enabled by default for Half-Duplex.
w.set_te(false);
w.set_re(true);
} else {
// enable transceiver
w.set_te(enable_tx);
// enable receiver
w.set_re(enable_rx);
}
// configure word size // configure word size
// if using odd or even parity it must be configured to 9bits // if using odd or even parity it must be configured to 9bits
w.set_m0(if config.parity != Parity::ParityNone { w.set_m0(if config.parity != Parity::ParityNone {