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stm32/rtc: Add auto-LSE-bypass detection with fallback to LSE then LSI. 

If MICROPY_HW_RTC_USE_BYPASS is enabled the RTC startup goes as follows:
- RTC is started with LSE in bypass mode to begin with
- if that fails to start (after a given timeout) then LSE is reconfigured
  in non-bypass
- if that fails to start then RTC is switched to LSI
This commit is contained in:
Damien George 2019-04-11 12:09:21 +10:00
parent d5f0c87bb9
commit 46e5d6b889
2 changed files with 52 additions and 19 deletions
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6
ports/stm32/mpconfigboard_common.h
View File

@ -210,6 +210,12 @@
#endif
#endif
// If disabled then try normal (non-bypass) LSE first, with fallback to LSI.
// If enabled first try LSE in bypass mode. If that fails to start, try non-bypass mode, with fallback to LSI.
#ifndef MICROPY_HW_RTC_USE_BYPASS
#define MICROPY_HW_RTC_USE_BYPASS (0)
#endif
#if MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE
// Provide block device macros if internal flash storage is enabled
#define MICROPY_HW_BDEV_IOCTL flash_bdev_ioctl

65
ports/stm32/rtc.c
View File

@ -61,11 +61,11 @@ static mp_uint_t rtc_info;
#endif
STATIC HAL_StatusTypeDef PYB_RTC_Init(RTC_HandleTypeDef *hrtc);
STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse);
STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse, bool rtc_use_byp);
STATIC HAL_StatusTypeDef PYB_RTC_MspInit_Finalise(RTC_HandleTypeDef *hrtc);
STATIC void RTC_CalendarConfig(void);
#if defined(MICROPY_HW_RTC_USE_LSE) && MICROPY_HW_RTC_USE_LSE
#if MICROPY_HW_RTC_USE_LSE || MICROPY_HW_RTC_USE_BYPASS
STATIC bool rtc_use_lse = true;
#else
STATIC bool rtc_use_lse = false;
@ -159,7 +159,7 @@ void rtc_init_start(bool force_init) {
rtc_info &= ~0x01000000;
}
}
PYB_RTC_MspInit_Kick(&RTCHandle, rtc_use_lse);
PYB_RTC_MspInit_Kick(&RTCHandle, rtc_use_lse, MICROPY_HW_RTC_USE_BYPASS);
}
void rtc_init_finalise() {
@ -167,26 +167,34 @@ void rtc_init_finalise() {
return;
}
rtc_info = 0x20000000;
if (PYB_RTC_Init(&RTCHandle) != HAL_OK) {
rtc_info = 0;
while (PYB_RTC_Init(&RTCHandle) != HAL_OK) {
if (rtc_use_lse) {
// fall back to LSI...
rtc_use_lse = false;
#if MICROPY_HW_RTC_USE_BYPASS
if (RCC->BDCR & RCC_BDCR_LSEBYP) {
// LSEBYP failed, fallback to LSE non-bypass
rtc_info |= 0x02000000;
} else
#endif
{
// LSE failed, fallback to LSI
rtc_use_lse = false;
rtc_info |= 0x01000000;
}
rtc_startup_tick = HAL_GetTick();
PYB_RTC_MspInit_Kick(&RTCHandle, rtc_use_lse);
PYB_RTC_MspInit_Kick(&RTCHandle, rtc_use_lse, false);
HAL_PWR_EnableBkUpAccess();
RTCHandle.State = HAL_RTC_STATE_RESET;
if (PYB_RTC_Init(&RTCHandle) != HAL_OK) {
rtc_info = 0x0100ffff; // indicate error
return;
}
} else {
// init error
rtc_info = 0xffff; // indicate error
rtc_info |= 0xffff; // indicate error
return;
}
}
// RTC started successfully
rtc_info = 0x20000000;
// record if LSE or LSI is used
rtc_info |= (rtc_use_lse << 28);
@ -257,6 +265,16 @@ STATIC HAL_StatusTypeDef PYB_RCC_OscConfig(RCC_OscInitTypeDef *RCC_OscInitStruc
}
#endif
#if MICROPY_HW_RTC_USE_BYPASS
// If LSEBYP is enabled and new state is non-bypass then disable LSEBYP
if (RCC_OscInitStruct->LSEState == RCC_LSE_ON && (RCC->BDCR & RCC_BDCR_LSEBYP)) {
CLEAR_BIT(RCC->BDCR, RCC_BDCR_LSEON);
while (RCC->BDCR & RCC_BDCR_LSERDY) {
}
CLEAR_BIT(RCC->BDCR, RCC_BDCR_LSEBYP);
}
#endif
// Set the new LSE configuration
__HAL_RCC_LSE_CONFIG(RCC_OscInitStruct->LSEState);
}
@ -327,7 +345,7 @@ STATIC HAL_StatusTypeDef PYB_RTC_Init(RTC_HandleTypeDef *hrtc) {
}
}
STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse) {
STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse, bool rtc_use_byp) {
/* To change the source clock of the RTC feature (LSE, LSI), You have to:
- Enable the power clock using __PWR_CLK_ENABLE()
- Enable write access using HAL_PWR_EnableBkUpAccess() function before to
@ -342,12 +360,14 @@ STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse) {
RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (rtc_use_lse) {
#if MICROPY_HW_RTC_USE_BYPASS
#if MICROPY_HW_RTC_USE_BYPASS
if (rtc_use_byp) {
RCC_OscInitStruct.LSEState = RCC_LSE_BYPASS;
#else
RCC_OscInitStruct.LSIState = RCC_LSI_OFF;
} else
#endif
if (rtc_use_lse) {
RCC_OscInitStruct.LSEState = RCC_LSE_ON;
#endif
RCC_OscInitStruct.LSIState = RCC_LSI_OFF;
} else {
RCC_OscInitStruct.LSEState = RCC_LSE_OFF;
@ -361,14 +381,21 @@ STATIC void PYB_RTC_MspInit_Kick(RTC_HandleTypeDef *hrtc, bool rtc_use_lse) {
#define PYB_LSE_TIMEOUT_VALUE 1000 // ST docs spec 2000 ms LSE startup, seems to be too pessimistic
#define PYB_LSI_TIMEOUT_VALUE 500 // this is way too pessimistic, typ. < 1ms
#define PYB_BYP_TIMEOUT_VALUE 150
STATIC HAL_StatusTypeDef PYB_RTC_MspInit_Finalise(RTC_HandleTypeDef *hrtc) {
// we already had a kick so now wait for the corresponding ready state...
if (rtc_use_lse) {
// we now have to wait for LSE ready or timeout
uint32_t timeout = PYB_LSE_TIMEOUT_VALUE;
#if MICROPY_HW_RTC_USE_BYPASS
if (RCC->BDCR & RCC_BDCR_LSEBYP) {
timeout = PYB_BYP_TIMEOUT_VALUE;
}
#endif
uint32_t tickstart = rtc_startup_tick;
while (__HAL_RCC_GET_FLAG(RCC_FLAG_LSERDY) == RESET) {
if ((HAL_GetTick() - tickstart ) > PYB_LSE_TIMEOUT_VALUE) {
if ((HAL_GetTick() - tickstart ) > timeout) {
return HAL_TIMEOUT;
}
}