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stmhal: Make RTC init skip startup if LTE is already enabled and ready. 

This prevents the loss of RTC time when exiting from standby mode, since
the RTC is paused while it is being re-inited and this loses about 120ms.

Thanks to @chuckbook for the patch.
This commit is contained in:
Peter Hinch 2015-10-27 10:55:47 +00:00 committed by Damien George
parent b83d0b35e9
commit 3819634469
1 changed files with 11 additions and 0 deletions
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11
stmhal/rtc.c
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@ -178,6 +178,17 @@ void rtc_init(void) {
RTCHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH; RTCHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
RTCHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN; RTCHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
// if LTE enabled & ready --> no need to (re-)init RTC
if ((RCC->BDCR & (RCC_BDCR_LSEON | RCC_BDCR_LSERDY)) == (RCC_BDCR_LSEON | RCC_BDCR_LSERDY)) {
// remove Backup Domain write protection
PWR->CR |= PWR_CR_DBP;
// Clear source Reset Flag
__HAL_RCC_CLEAR_RESET_FLAGS();
// provide some status information
rtc_info |= 0x40000 | (RCC->BDCR & 7) | (RCC->CSR & 3) << 8;
return;
}
mp_uint_t tick = HAL_GetTick(); mp_uint_t tick = HAL_GetTick();
if (HAL_RTC_Init(&RTCHandle) != HAL_OK) { if (HAL_RTC_Init(&RTCHandle) != HAL_OK) {