RTC. Setting and getting time works on STM32F4x

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/rtc_dev@3596 35acf78f-673a-0410-8e92-d51de3d6d3f4

os/hal/platforms/STM32F4xx/hal_lld.h

@@ -320,6 +320,7 @@
 
 /* RTC attributes.*/
 #define STM32_HAS_RTC           TRUE
+#define RTC_HAS_SUBSECONDS      TRUE
 
 /* SDIO attributes.*/
 #define STM32_HAS_SDIO          TRUE

os/hal/platforms/STM32F4xx/rtc_lld.c

@@ -31,6 +31,24 @@
 
 #if HAL_USE_RTC || defined(__DOXYGEN__)
 
+/*===========================================================================*/
+/* Notes.                                                                    */
+/*===========================================================================*/
+/*
+This structure is used to hold the values representing a calendar time.
+It contains the following members, with the meanings as shown.
+
+int tm_sec      // seconds after minute [0-61] (61 allows for 2 leap-seconds)
+int tm_min      // minutes after hour [0-59] 
+int tm_hour     // hours after midnight [0-23] 
+int tm_mday     // day of the month [1-31] 
+int tm_mon      // month of year [0-11] 
+int tm_year     // current year-1900 
+int tm_wday     // days since Sunday [0-6] 
+int tm_yday     // days since January 1st [0-365] 
+int tm_isdst    // daylight savings indicator (1 = yes, 0 = no, -1 = unknown)
+*/
+
 /*===========================================================================*/
 /* Driver exported variables.                                                */
 /*===========================================================================*/
@@ -65,7 +83,11 @@ RTCDriver RTCD1;
  * @notapi
  */
 void rtc_lld_init(void){
-  uint32_t preload;
+  /* Asynchronous part of preloader. Set it to maximum value. */
+  #define PREDIV_A ((uint32_t)0x7F)
+
+  /* Add async part to preload value. */
+  uint32_t preload = PREDIV_A << 16;
 
   /* Enables access to BKP registers.*/
   PWR->CR |= PWR_CR_DBP;
@@ -77,35 +99,35 @@ void rtc_lld_init(void){
   }
 
 #if STM32_RTC == STM32_RTC_LSE
+  #define RTC_CLK   STM32_LSECLK
   if (!(RCC->BDCR & RCC_BDCR_LSEON)) {
     RCC->BDCR |= RCC_BDCR_LSEON;
     while (!(RCC->BDCR & RCC_BDCR_LSERDY))
       ;
   }
-  preload = STM32_LSECLK - 1;
+
 #elif STM32_RTC == STM32_RTC_LSI
+  #define RTC_CLK   STM32_LSICLK
   /* TODO: Move the LSI clock initialization in the HAL low level driver.*/
   RCC->CSR |= RCC_CSR_LSION;
   while (!(RCC->CSR & RCC_CSR_LSIRDY))
     ;
-  /* According to errata sheet we must wait additional 100 uS for
+
-     stabilization.
-     TODO: Change this code, software loops are not reliable.*/
-  uint32_t tmo = (STM32_SYSCLK / 1000000) * 100;
-  while (tmo--)
-    ;
-  preload = STM32_LSICLK - 1;
 #elif STM32_RTC == STM32_RTC_HSE
-  preload = (STM32_HSICLK / 128) - 1;
+  #define RTC_CLK   (STM32_HSICLK / 31)
 #endif
 
+  /* Add sync part to preload value. */
+  preload |= ((RTC_CLK / (PREDIV_A + 1)) - 1) & 0x7FFF;
+
   /* Selects clock source (previously enabled and stabilized).*/
   RCC->BDCR = (RCC->BDCR & ~RCC_BDCR_RTCSEL) | STM32_RTC;
 
   /* RTC enabled regardless its previous status.*/
   RCC->BDCR |= RCC_BDCR_RTCEN;
 
-  if (!(RTC->ISR & RTC_ISR_INITS)){/* Calendar not init yet. */
+  /* If calendar not init yet. */
+  if (!(RTC->ISR & RTC_ISR_INITS)){
     /* Disable write protection on RTC registers. */
     RTC->WPR = 0xCA;
     RTC->WPR = 0x53;
@@ -115,13 +137,9 @@ void rtc_lld_init(void){
     while(!(RTC->ISR & RTC_ISR_INITF))
       ;
     /* Prescaler registers must be written in by two separate writes. */
-    RTC->PRER = 0x007F00FF;
+    RTC->PRER = preload;
-    RTC->PRER = 0x007F00FF;
+    RTC->PRER = preload;
     RTC->ISR &= ~RTC_ISR_INIT;
-
-    /* Wait until calendar data will updated. */
-    while(!(RTC->ISR & RTC_ISR_RSF))
-      ;
   }
 
   /* Callback initially disabled.*/
@@ -147,10 +165,6 @@ void rtc_lld_set_time(RTCDriver *rtcp, const RTCTime *timespec) {
   RTC->TR = timespec->tv_time;
   RTC->DR = timespec->tv_date;
   RTC->ISR &= ~RTC_ISR_INIT;
-
-  /* Wait until calendar data will updated. */
-  while(!(RTC->ISR & RTC_ISR_RSF))
-    ;
 }
 
 /**
@@ -173,8 +187,14 @@ void rtc_lld_get_time(RTCDriver *rtcp, RTCTime *timespec) {
 
   timespec->tv_time = RTC->TR;
   timespec->tv_date = RTC->DR;
+#if RTC_HAS_SUBSECONDS
+  timespec->tv_msec = ((RTC->PRER & 0x7FFF) - RTC->SSR) / ((RTC->PRER & 0x7FFF) + 1);
+#else
+  timespec->tv_msec = 0;
+#endif /* STM32_RTC_HAS_SUBSECONDS */
 }
 
+
 /**
  * @brief   Set alarm time.
  *
@@ -189,7 +209,6 @@ void rtc_lld_get_time(RTCDriver *rtcp, RTCTime *timespec) {
 void rtc_lld_set_alarm(RTCDriver *rtcp,
                        rtcalarm_t alarm,
                        const RTCAlarm *alarmspec) {
-
   (void)rtcp;
   (void)alarm;
   (void)alarmspec;

os/hal/platforms/STM32F4xx/rtc_lld.h

@@ -41,7 +41,7 @@
 #define RTC_SUPPORTS_CALLBACKS      TRUE
 
 /**
- * @brief   One alarm comparator available.
+ * @brief   Two alarm comparators available on STM32F4x.
  */
 #define RTC_ALARMS                  2
 
@@ -62,6 +62,10 @@
 #error "invalid source selected for RTC clock"
 #endif
 
+#if RTC_SUPPORTS_CALLBACKS && !(HAL_USE_EXT)
+#error "interrupts from STM32 RTC works only through EXTI"
+#endif
+
 /*===========================================================================*/
 /* Driver data structures and types.                                         */
 /*===========================================================================*/
@@ -97,13 +101,18 @@ typedef void (*rtccb_t)(RTCDriver *rtcp, rtcevent_t event);
  */
 struct RTCTime {
   /**
-   * @brief RTC date register in BCD format.
+   * @brief RTC date register in STM32 BCD format.
    */
   uint32_t tv_date;
   /**
-   * @brief RTC time register in BCD format.
+   * @brief RTC time register in STM32 BCD format.
    */
   uint32_t tv_time;
+  /**
+   * @brief Fractional part of time.
+   * @note  If platform does not support subseconds than always zero.
+   */
+  uint16_t tv_msec;
 };
 
 
@@ -112,7 +121,7 @@ struct RTCTime {
  */
 struct RTCAlarm {
   /**
-   * @brief Date and time of alarm in BCD.
+   * @brief Date and time of alarm in STM32 BCD.
    */
   uint32_t tv_datetime;
 };

testhal/STM32F1xx/RTC/main.c

@@ -24,7 +24,7 @@
 RTCTime timespec;
 RTCAlarm alarmspec;
 
-#define TEST_ALARM_WAKEUP FALSE
+#define TEST_ALARM_WAKEUP TRUE
 
 #if TEST_ALARM_WAKEUP
 
@@ -45,9 +45,9 @@ int main(void) {
 
   chThdCreateStatic(blinkWA, sizeof(blinkWA), NORMALPRIO, blink_thd, NULL);
   /* set alarm in near future */
-  rtcGetTime(&timespec);
+  rtcGetTime(&RTCD1, &timespec);
   alarmspec.tv_sec = timespec.tv_sec + 60;
-  rtcSetAlarm(&alarmspec);
+  rtcSetAlarm(&RTCD1, 0, &alarmspec);
 
   while (TRUE){
       chThdSleepSeconds(10);