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stm32/low-power: create one critical-section for all time ops

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This commit is contained in:
xoviat 2023-09-21 19:32:48 -05:00
parent 02b0523199
commit 7cf327130e
3 changed files with 99 additions and 80 deletions
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46
embassy-stm32/src/rtc/v2.rs
View File

@ -64,7 +64,11 @@ impl super::Rtc {
#[cfg(feature = "low-power")]
/// start the wakeup alarm and wtih a duration that is as close to but less than
/// the requested duration, and record the instant the wakeup alarm was started
pub(crate) fn start_wakeup_alarm(&self, requested_duration: embassy_time::Duration) {
pub(crate) fn start_wakeup_alarm(
&self,
requested_duration: embassy_time::Duration,
cs: critical_section::CriticalSection,
) {
use embassy_time::{Duration, TICK_HZ};
#[cfg(any(rcc_wb, rcc_f4, rcc_f410))]
@ -102,25 +106,13 @@ impl super::Rtc {
self.instant(),
);
critical_section::with(|cs| assert!(self.stop_time.borrow(cs).replace(Some(self.instant())).is_none()))
}
#[cfg(feature = "low-power")]
pub(crate) fn enable_wakeup_line(&self) {
use crate::interrupt::typelevel::Interrupt;
use crate::pac::EXTI;
<RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::unpend();
unsafe { <RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::enable() };
EXTI.rtsr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
EXTI.imr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
assert!(self.stop_time.borrow(cs).replace(Some(self.instant())).is_none())
}
#[cfg(feature = "low-power")]
/// stop the wakeup alarm and return the time elapsed since `start_wakeup_alarm`
/// was called, otherwise none
pub(crate) fn stop_wakeup_alarm(&self) -> Option<embassy_time::Duration> {
pub(crate) fn stop_wakeup_alarm(&self, cs: critical_section::CriticalSection) -> Option<embassy_time::Duration> {
use crate::interrupt::typelevel::Interrupt;
trace!("rtc: stop wakeup alarm at {}", self.instant());
@ -137,13 +129,23 @@ impl super::Rtc {
<RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::unpend();
});
critical_section::with(|cs| {
if let Some(stop_time) = self.stop_time.borrow(cs).take() {
Some(self.instant() - stop_time)
} else {
None
}
})
if let Some(stop_time) = self.stop_time.borrow(cs).take() {
Some(self.instant() - stop_time)
} else {
None
}
}
#[cfg(feature = "low-power")]
pub(crate) fn enable_wakeup_line(&self) {
use crate::interrupt::typelevel::Interrupt;
use crate::pac::EXTI;
<RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::unpend();
unsafe { <RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::enable() };
EXTI.rtsr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
EXTI.imr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
}
/// Applies the RTC config

100
embassy-stm32/src/time_driver.rs
View File

@ -266,32 +266,28 @@ impl RtcDriver {
f(alarm.ctx.get());
}
#[cfg(feature = "low-power")]
/// Set the rtc but panic if it's already been set
pub(crate) fn set_rtc(&self, rtc: &'static Rtc) {
critical_section::with(|cs| assert!(self.rtc.borrow(cs).replace(Some(rtc)).is_none()));
}
/*
Low-power private functions: all operate within a critical seciton
*/
#[cfg(feature = "low-power")]
/// Compute the approximate amount of time until the next alarm
fn time_until_next_alarm(&self) -> embassy_time::Duration {
critical_section::with(|cs| {
let now = self.now() + 32;
fn time_until_next_alarm(&self, cs: CriticalSection) -> embassy_time::Duration {
let now = self.now() + 32;
embassy_time::Duration::from_ticks(
self.alarms
.borrow(cs)
.iter()
.map(|alarm: &AlarmState| alarm.timestamp.get().saturating_sub(now))
.min()
.unwrap_or(u64::MAX),
)
})
embassy_time::Duration::from_ticks(
self.alarms
.borrow(cs)
.iter()
.map(|alarm: &AlarmState| alarm.timestamp.get().saturating_sub(now))
.min()
.unwrap_or(u64::MAX),
)
}
#[cfg(feature = "low-power")]
/// Add the given offset to the current time
fn add_time(&self, offset: embassy_time::Duration) {
fn add_time(&self, offset: embassy_time::Duration, cs: CriticalSection) {
let offset = offset.as_ticks();
let cnt = T::regs_gp16().cnt().read().cnt() as u32;
let period = self.period.load(Ordering::SeqCst);
@ -322,51 +318,57 @@ impl RtcDriver {
T::regs_gp16().cnt().write(|w| w.set_cnt(cnt as u16));
// Now, recompute all alarms
critical_section::with(|cs| {
for i in 0..ALARM_COUNT {
let alarm_handle = unsafe { AlarmHandle::new(i as u8) };
let alarm = self.get_alarm(cs, alarm_handle);
for i in 0..ALARM_COUNT {
let alarm_handle = unsafe { AlarmHandle::new(i as u8) };
let alarm = self.get_alarm(cs, alarm_handle);
self.set_alarm(alarm_handle, alarm.timestamp.get());
}
})
self.set_alarm(alarm_handle, alarm.timestamp.get());
}
}
#[cfg(feature = "low-power")]
/// Stop the wakeup alarm, if enabled, and add the appropriate offset
fn stop_wakeup_alarm(&self) {
critical_section::with(|cs| {
if let Some(offset) = self.rtc.borrow(cs).get().unwrap().stop_wakeup_alarm() {
self.add_time(offset);
}
});
fn stop_wakeup_alarm(&self, cs: CriticalSection) {
if let Some(offset) = self.rtc.borrow(cs).get().unwrap().stop_wakeup_alarm(cs) {
self.add_time(offset, cs);
}
}
/*
Low-power public functions: all create a critical section
*/
#[cfg(feature = "low-power")]
/// Set the rtc but panic if it's already been set
pub(crate) fn set_rtc(&self, rtc: &'static Rtc) {
critical_section::with(|cs| assert!(self.rtc.borrow(cs).replace(Some(rtc)).is_none()));
}
#[cfg(feature = "low-power")]
/// Pause the timer if ready; return err if not
pub(crate) fn pause_time(&self) -> Result<(), ()> {
/*
If the wakeup timer is currently running, then we need to stop it and
add the elapsed time to the current time
*/
self.stop_wakeup_alarm();
critical_section::with(|cs| {
/*
If the wakeup timer is currently running, then we need to stop it and
add the elapsed time to the current time, as this will impact the result
of `time_until_next_alarm`.
*/
self.stop_wakeup_alarm(cs);
let time_until_next_alarm = self.time_until_next_alarm();
if time_until_next_alarm < embassy_time::Duration::from_millis(250) {
Err(())
} else {
critical_section::with(|cs| {
let time_until_next_alarm = self.time_until_next_alarm(cs);
if time_until_next_alarm < embassy_time::Duration::from_millis(250) {
Err(())
} else {
self.rtc
.borrow(cs)
.get()
.unwrap()
.start_wakeup_alarm(time_until_next_alarm);
});
.start_wakeup_alarm(time_until_next_alarm, cs);
T::regs_gp16().cr1().modify(|w| w.set_cen(false));
T::regs_gp16().cr1().modify(|w| w.set_cen(false));
Ok(())
}
Ok(())
}
})
}
#[cfg(feature = "low-power")]
@ -378,9 +380,11 @@ impl RtcDriver {
return;
}
self.stop_wakeup_alarm();
critical_section::with(|cs| {
self.stop_wakeup_alarm(cs);
T::regs_gp16().cr1().modify(|w| w.set_cen(true));
T::regs_gp16().cr1().modify(|w| w.set_cen(true));
})
}
}

33
tests/stm32/src/bin/stop.rs
View File

@ -19,14 +19,32 @@ use static_cell::make_static;
#[entry]
fn main() -> ! {
let executor = Executor::take();
executor.run(|spawner| {
Executor::take().run(|spawner| {
unwrap!(spawner.spawn(async_main(spawner)));
});
}
#[embassy_executor::task]
async fn async_main(_spawner: Spawner) {
async fn task_1() {
for _ in 0..9 {
info!("task 1: waiting for 500ms...");
Timer::after(Duration::from_millis(500)).await;
}
}
#[embassy_executor::task]
async fn task_2() {
for _ in 0..5 {
info!("task 2: waiting for 1000ms...");
Timer::after(Duration::from_millis(1000)).await;
}
info!("Test OK");
cortex_m::asm::bkpt();
}
#[embassy_executor::task]
async fn async_main(spawner: Spawner) {
let mut config = config();
config.rcc.lse = Some(Hertz(32_768));
@ -48,11 +66,6 @@ async fn async_main(_spawner: Spawner) {
stop_with_rtc(rtc);
info!("Waiting...");
Timer::after(Duration::from_secs(2)).await;
info!("Waiting...");
Timer::after(Duration::from_secs(3)).await;
info!("Test OK");
cortex_m::asm::bkpt();
spawner.spawn(task_1()).unwrap();
spawner.spawn(task_2()).unwrap();
}