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stm32/rtc: Use LL_RTC functions to simplify some MCU-specific code. 

This also fixes a possible race condition when exiting initialisation mode:
reading then writing to ISR (via ISR &= ~RTC_ISR_INIT) will clear any flags
that were set by the hardware between the read and the write.  The correct
way to clear just the INIT bit is to just do a single write via ISR =
~RTC_ISR_INIT, which will not clear any other flags (they must be written
to 0 to clear), and that is exactly what LL_RTC_DisableInitMode does.

Signed-off-by: Damien George <damien@micropython.org>
This commit is contained in:
Damien George 2022-02-04 08:30:39 +11:00
parent 26faf74d52
commit e4f59a0020
1 changed files with 2 additions and 11 deletions
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13
ports/stm32/rtc.c
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@ -339,11 +339,7 @@ STATIC HAL_StatusTypeDef PYB_RTC_Init(RTC_HandleTypeDef *hrtc) {
hrtc->Instance->PRER |= (uint32_t)(hrtc->Init.AsynchPrediv << 16);
// Exit Initialization mode
#if defined(STM32G4) || defined(STM32H7A3xx) || defined(STM32H7A3xxQ) || defined(STM32H7B3xx) || defined(STM32H7B3xxQ)
hrtc->Instance->ICSR &= (uint32_t) ~RTC_ICSR_INIT;
#else
hrtc->Instance->ISR &= (uint32_t) ~RTC_ISR_INIT;
#endif
LL_RTC_DisableInitMode(hrtc->Instance);
#if defined(STM32H7A3xx) || defined(STM32H7A3xxQ) || defined(STM32H7B3xx) || defined(STM32H7B3xxQ)
// do nothing
@ -702,13 +698,8 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
RTC->CR &= ~RTC_CR_WUTE;
// wait until WUTWF is set
#if defined(STM32G4) || defined(STM32H7A3xx) || defined(STM32H7A3xxQ) || defined(STM32H7B3xx) || defined(STM32H7B3xxQ)
while (!(RTC->ICSR & RTC_ICSR_WUTWF)) {
while (!LL_RTC_IsActiveFlag_WUTW(RTC)) {
}
#else
while (!(RTC->ISR & RTC_ISR_WUTWF)) {
}
#endif
if (enable) {
// program WUT