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Acquire semaphore on blocking

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This commit is contained in:
Henrik Alsér 2022-11-05 01:34:52 +01:00
parent 7da18e194a
commit 207fa19551
1 changed files with 14 additions and 3 deletions
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17
embassy-nrf/src/spis.rs
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@ -257,9 +257,19 @@ impl<'d, T: Instance> Spis<'d, T> {
} }
fn blocking_inner_from_ram(&mut self, rx: *mut [u8], tx: *const [u8]) -> Result<(usize, usize), Error> { fn blocking_inner_from_ram(&mut self, rx: *mut [u8], tx: *const [u8]) -> Result<(usize, usize), Error> {
self.prepare(rx, tx)?; compiler_fence(Ordering::SeqCst);
let r = T::regs(); let r = T::regs();
// Acquire semaphore.
if r.semstat.read().bits() != 1 {
r.events_acquired.reset();
r.tasks_acquire.write(|w| unsafe { w.bits(1) });
// Wait until CPU has acquired the semaphore.
while r.semstat.read().bits() != 1 {}
}
self.prepare(rx, tx)?;
// Wait for 'end' event. // Wait for 'end' event.
while r.events_end.read().bits() == 0 {} while r.events_end.read().bits() == 0 {}
@ -291,6 +301,7 @@ impl<'d, T: Instance> Spis<'d, T> {
// Clear status register. // Clear status register.
r.status.write(|w| w.overflow().clear().overread().clear()); r.status.write(|w| w.overflow().clear().overread().clear());
// Acquire semaphore.
if r.semstat.read().bits() != 1 { if r.semstat.read().bits() != 1 {
// Reset and enable the acquire event. // Reset and enable the acquire event.
r.events_acquired.reset(); r.events_acquired.reset();
@ -299,10 +310,10 @@ impl<'d, T: Instance> Spis<'d, T> {
// Request acquiring the SPIS semaphore. // Request acquiring the SPIS semaphore.
r.tasks_acquire.write(|w| unsafe { w.bits(1) }); r.tasks_acquire.write(|w| unsafe { w.bits(1) });
// Wait for 'acquire' event. // Wait until CPU has acquired the semaphore.
poll_fn(|cx| { poll_fn(|cx| {
s.acquire_waker.register(cx.waker()); s.acquire_waker.register(cx.waker());
if r.events_acquired.read().bits() != 0 { if r.semstat.read().bits() == 1 {
return Poll::Ready(()); return Poll::Ready(());
} }
Poll::Pending Poll::Pending