108 lines
3.5 KiB
C
108 lines
3.5 KiB
C
#define RCC_BDCR_OPTIONS (RCC_BDCR_RTCEN | RCC_BDCR_RTCSEL_0 | RCC_BDCR_LSEON)
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#define RCC_BDCR_MASK (RCC_BDCR_RTCEN | RCC_BDCR_RTCSEL | RCC_BDCR_LSEMOD | RCC_BDCR_LSEBYP | RCC_BDCR_LSEON)
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#define YEAR_OFFSET 2000U
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typedef struct __attribute__((packed)) timestamp_t {
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uint16_t year;
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uint8_t month;
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uint8_t day;
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uint8_t weekday;
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uint8_t hour;
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uint8_t minute;
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uint8_t second;
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} timestamp_t;
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uint8_t to_bcd(uint16_t value){
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return (((value / 10U) & 0x0FU) << 4U) | ((value % 10U) & 0x0FU);
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}
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uint16_t from_bcd(uint8_t value){
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return (((value & 0xF0U) >> 4U) * 10U) + (value & 0x0FU);
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}
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void rtc_init(void){
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if(board_has_rtc()){
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// Initialize RTC module and clock if not done already.
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if((RCC->BDCR & RCC_BDCR_MASK) != RCC_BDCR_OPTIONS){
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puts("Initializing RTC\n");
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// Reset backup domain
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register_set_bits(&(RCC->BDCR), RCC_BDCR_BDRST);
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// Disable write protection
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register_set_bits(&(PWR->CR), PWR_CR_DBP);
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// Clear backup domain reset
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register_clear_bits(&(RCC->BDCR), RCC_BDCR_BDRST);
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// Set RTC options
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register_set(&(RCC->BDCR), RCC_BDCR_OPTIONS, RCC_BDCR_MASK);
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// Enable write protection
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register_clear_bits(&(PWR->CR), PWR_CR_DBP);
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}
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}
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}
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void rtc_set_time(timestamp_t time){
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if(board_has_rtc()){
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puts("Setting RTC time\n");
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// Disable write protection
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register_set_bits(&(PWR->CR), PWR_CR_DBP);
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RTC->WPR = 0xCA;
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RTC->WPR = 0x53;
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// Enable initialization mode
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register_set_bits(&(RTC->ISR), RTC_ISR_INIT);
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while((RTC->ISR & RTC_ISR_INITF) == 0){}
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// Set time
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RTC->TR = (to_bcd(time.hour) << RTC_TR_HU_Pos) | (to_bcd(time.minute) << RTC_TR_MNU_Pos) | (to_bcd(time.second) << RTC_TR_SU_Pos);
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RTC->DR = (to_bcd(time.year - YEAR_OFFSET) << RTC_DR_YU_Pos) | (time.weekday << RTC_DR_WDU_Pos) | (to_bcd(time.month) << RTC_DR_MU_Pos) | (to_bcd(time.day) << RTC_DR_DU_Pos);
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// Set options
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register_set(&(RTC->CR), 0U, 0xFCFFFFU);
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// Disable initalization mode
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register_clear_bits(&(RTC->ISR), RTC_ISR_INIT);
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// Wait for synchronization
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while((RTC->ISR & RTC_ISR_RSF) == 0){}
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// Re-enable write protection
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RTC->WPR = 0x00;
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register_clear_bits(&(PWR->CR), PWR_CR_DBP);
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}
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}
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timestamp_t rtc_get_time(void){
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timestamp_t result;
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// Init with zero values in case there is no RTC running
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result.year = 0U;
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result.month = 0U;
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result.day = 0U;
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result.weekday = 0U;
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result.hour = 0U;
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result.minute = 0U;
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result.second = 0U;
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if(board_has_rtc()){
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// Wait until the register sync flag is set
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while((RTC->ISR & RTC_ISR_RSF) == 0){}
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// Read time and date registers. Since our HSE > 7*LSE, this should be fine.
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uint32_t time = RTC->TR;
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uint32_t date = RTC->DR;
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// Parse values
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result.year = from_bcd((date & (RTC_DR_YT | RTC_DR_YU)) >> RTC_DR_YU_Pos) + YEAR_OFFSET;
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result.month = from_bcd((date & (RTC_DR_MT | RTC_DR_MU)) >> RTC_DR_MU_Pos);
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result.day = from_bcd((date & (RTC_DR_DT | RTC_DR_DU)) >> RTC_DR_DU_Pos);
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result.weekday = ((date & RTC_DR_WDU) >> RTC_DR_WDU_Pos);
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result.hour = from_bcd((time & (RTC_TR_HT | RTC_TR_HU)) >> RTC_TR_HU_Pos);
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result.minute = from_bcd((time & (RTC_TR_MNT | RTC_TR_MNU)) >> RTC_TR_MNU_Pos);
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result.second = from_bcd((time & (RTC_TR_ST | RTC_TR_SU)) >> RTC_TR_SU_Pos);
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}
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return result;
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} |