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Added anomaly workaround from the HAL to improve the UARTE

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This commit is contained in:
Dion Dokter 2021-10-12 13:35:08 +02:00
parent 2c2c284482
commit ddcee446c1
1 changed files with 56 additions and 0 deletions
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56
embassy-nrf/src/uarte.rs
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@ -114,6 +114,7 @@ impl<'d, T: Instance> Uarte<'d, T> {
irq.enable();
// Enable
Self::apply_workaround_for_enable_anomaly();
r.enable.write(|w| w.enable().enabled());
Self {
@ -121,6 +122,61 @@ impl<'d, T: Instance> Uarte<'d, T> {
}
}
#[cfg(not(any(feature = "nrf9160", feature = "nrf5340")))]
fn apply_workaround_for_enable_anomaly() {
// Do nothing
}
#[cfg(any(feature = "nrf9160", feature = "nrf5340"))]
fn apply_workaround_for_enable_anomaly() {
use core::ops::Deref;
let r = T::regs();
// Apply workaround for anomalies:
// - nRF9160 - anomaly 23
// - nRF5340 - anomaly 44
let rxenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x564) as *const u32;
let txenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x568) as *const u32;
// NB Safety: This is taken from Nordic's driver -
// https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
if unsafe { core::ptr::read_volatile(txenable_reg) } == 1 {
r.tasks_stoptx.write(|w| unsafe { w.bits(1) });
}
// NB Safety: This is taken from Nordic's driver -
// https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
if unsafe { core::ptr::read_volatile(rxenable_reg) } == 1 {
r.enable.write(|w| w.enable().enabled());
r.tasks_stoprx.write(|w| unsafe { w.bits(1) });
let mut workaround_succeded = false;
// The UARTE is able to receive up to four bytes after the STOPRX task has been triggered.
// On lowest supported baud rate (1200 baud), with parity bit and two stop bits configured
// (resulting in 12 bits per data byte sent), this may take up to 40 ms.
for _ in 0..40000 {
// NB Safety: This is taken from Nordic's driver -
// https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
if unsafe { core::ptr::read_volatile(rxenable_reg) } == 0 {
workaround_succeded = true;
break;
} else {
// Need to sleep for 1us here
}
}
if !workaround_succeded {
panic!("Failed to apply workaround for UART");
}
let errors = r.errorsrc.read().bits();
// NB Safety: safe to write back the bits we just read to clear them
r.errorsrc.write(|w| unsafe { w.bits(errors) });
r.enable.write(|w| w.enable().disabled());
}
}
fn on_interrupt(_: *mut ()) {
let r = T::regs();
let s = T::state();