max/embassy
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #1549 from timokroeger/uart_rx_idle

Browse Source 
embassy-nrf: Idle detection for RX only uarte
This commit is contained in:
Dario Nieuwenhuis 2023-06-13 09:43:32 +00:00 committed by GitHub
commit 38891c29ea
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 51 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

95
embassy-nrf/src/uarte.rs
View File

@ -205,50 +205,7 @@ impl<'d, T: Instance> Uarte<'d, T> {
ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
) -> (UarteTx<'d, T>, UarteRxWithIdle<'d, T, U>) {
let timer = Timer::new(timer);
into_ref!(ppi_ch1, ppi_ch2);
let r = T::regs();
// BAUDRATE register values are `baudrate * 2^32 / 16000000`
// source: https://devzone.nordicsemi.com/f/nordic-q-a/391/uart-baudrate-register-values
//
// We want to stop RX if line is idle for 2 bytes worth of time
// That is 20 bits (each byte is 1 start bit + 8 data bits + 1 stop bit)
// This gives us the amount of 16M ticks for 20 bits.
let baudrate = r.baudrate.read().baudrate().variant().unwrap();
let timeout = 0x8000_0000 / (baudrate as u32 / 40);
timer.set_frequency(Frequency::F16MHz);
timer.cc(0).write(timeout);
timer.cc(0).short_compare_clear();
timer.cc(0).short_compare_stop();
let mut ppi_ch1 = Ppi::new_one_to_two(
ppi_ch1.map_into(),
Event::from_reg(&r.events_rxdrdy),
timer.task_clear(),
timer.task_start(),
);
ppi_ch1.enable();
let mut ppi_ch2 = Ppi::new_one_to_one(
ppi_ch2.map_into(),
timer.cc(0).event_compare(),
Task::from_reg(&r.tasks_stoprx),
);
ppi_ch2.enable();
(
self.tx,
UarteRxWithIdle {
rx: self.rx,
timer,
ppi_ch1: ppi_ch1,
_ppi_ch2: ppi_ch2,
},
)
(self.tx, self.rx.with_idle(timer, ppi_ch1, ppi_ch2))
}
/// Return the endtx event for use with PPI
@ -563,6 +520,56 @@ impl<'d, T: Instance> UarteRx<'d, T> {
Self { _p: uarte }
}
/// Upgrade to an instance that supports idle line detection.
pub fn with_idle<U: TimerInstance>(
self,
timer: impl Peripheral<P = U> + 'd,
ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
) -> UarteRxWithIdle<'d, T, U> {
let timer = Timer::new(timer);
into_ref!(ppi_ch1, ppi_ch2);
let r = T::regs();
// BAUDRATE register values are `baudrate * 2^32 / 16000000`
// source: https://devzone.nordicsemi.com/f/nordic-q-a/391/uart-baudrate-register-values
//
// We want to stop RX if line is idle for 2 bytes worth of time
// That is 20 bits (each byte is 1 start bit + 8 data bits + 1 stop bit)
// This gives us the amount of 16M ticks for 20 bits.
let baudrate = r.baudrate.read().baudrate().variant().unwrap();
let timeout = 0x8000_0000 / (baudrate as u32 / 40);
timer.set_frequency(Frequency::F16MHz);
timer.cc(0).write(timeout);
timer.cc(0).short_compare_clear();
timer.cc(0).short_compare_stop();
let mut ppi_ch1 = Ppi::new_one_to_two(
ppi_ch1.map_into(),
Event::from_reg(&r.events_rxdrdy),
timer.task_clear(),
timer.task_start(),
);
ppi_ch1.enable();
let mut ppi_ch2 = Ppi::new_one_to_one(
ppi_ch2.map_into(),
timer.cc(0).event_compare(),
Task::from_reg(&r.tasks_stoprx),
);
ppi_ch2.enable();
UarteRxWithIdle {
rx: self,
timer,
ppi_ch1: ppi_ch1,
_ppi_ch2: ppi_ch2,
}
}
/// Read bytes until the buffer is filled.
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
if buffer.len() == 0 {