stmhal: Clean up rtc.c a bit.

stmhal/rtc.c

@@ -7,15 +7,13 @@
 #include "qstr.h"
 #include "obj.h"
 #include "runtime.h"
-//#include "systick.h"
 #include "rtc.h"
 
 RTC_HandleTypeDef RTCHandle;
-static machine_uint_t rtc_info;
 
-#define RTC_INFO_USE_EXISTING (0)
-#define RTC_INFO_USE_LSE (1)
-#define RTC_INFO_USE_LSI (3)
+// rtc_info indicates various things about RTC startup
+// it's a bit of a hack at the moment
+static machine_uint_t rtc_info;
 
 // Note: LSI is around (32KHz), these dividers should work either way
 // ck_spre(1Hz) = RTCCLK(LSE) /(uwAsynchPrediv + 1)*(uwSynchPrediv + 1)
@@ -23,6 +21,10 @@ static machine_uint_t rtc_info;
 #define RTC_SYNCH_PREDIV  (0x00ff)
 
 #if 0
+#define RTC_INFO_USE_EXISTING (0)
+#define RTC_INFO_USE_LSE (1)
+#define RTC_INFO_USE_LSI (3)
+
 void rtc_init(void) {
     // Enable the PWR clock
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
@@ -124,100 +126,82 @@ void rtc_init(void) {
 static void RTC_CalendarConfig(void);
 
 void rtc_init(void) {
-  /*##-1- Configure the RTC peripheral #######################################*/
-  RTCHandle.Instance = RTC;
+    RTCHandle.Instance = RTC;
 
-  /* Configure RTC prescaler and RTC data registers */
-  /* RTC configured as follow:
+    /* Configure RTC prescaler and RTC data registers */
+    /* RTC configured as follow:
       - Hour Format    = Format 24
       - Asynch Prediv  = Value according to source clock
       - Synch Prediv   = Value according to source clock
       - OutPut         = Output Disable
       - OutPutPolarity = High Polarity
-      - OutPutType     = Open Drain */ 
-  RTCHandle.Init.HourFormat = RTC_HOURFORMAT_24;
-  RTCHandle.Init.AsynchPrediv = RTC_ASYNCH_PREDIV;
-  RTCHandle.Init.SynchPrediv = RTC_SYNCH_PREDIV;
-  RTCHandle.Init.OutPut = RTC_OUTPUT_DISABLE;
-  RTCHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
-  RTCHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
-  
+      - OutPutType     = Open Drain */
+    RTCHandle.Init.HourFormat = RTC_HOURFORMAT_24;
+    RTCHandle.Init.AsynchPrediv = RTC_ASYNCH_PREDIV;
+    RTCHandle.Init.SynchPrediv = RTC_SYNCH_PREDIV;
+    RTCHandle.Init.OutPut = RTC_OUTPUT_DISABLE;
+    RTCHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
+    RTCHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
+
     machine_uint_t tick = HAL_GetTick();
 
-  if(HAL_RTC_Init(&RTCHandle) != HAL_OK)
-  {
-    /* Initialization Error */
-    //Error_Handler(); 
-    return;
-  }
-  
+    if (HAL_RTC_Init(&RTCHandle) != HAL_OK) {
+        // init error
+        rtc_info = 0xffff; // indicate error
+        return;
+    }
+
     // record how long it took for the RTC to start up
     rtc_info = HAL_GetTick() - tick;
 
-  /*##-2- Check if Data stored in BackUp register0: No Need to reconfigure RTC#*/
-  /* Read the Back Up Register 0 Data */
-  if(HAL_RTCEx_BKUPRead(&RTCHandle, RTC_BKP_DR0) != 0x32F2)
-  {  
-    /* Configure RTC Calendar */
-    RTC_CalendarConfig();
-  }
-  else
-  {
-    /* Check if the Power On Reset flag is set */  
-    if(__HAL_RCC_GET_FLAG(RCC_FLAG_PORRST) != RESET)
-    {
-      /* Turn on LED2: Power on reset occured */
-      //BSP_LED_On(LED2);
+    // check data stored in BackUp register0
+    if (HAL_RTCEx_BKUPRead(&RTCHandle, RTC_BKP_DR0) != 0x32f2) {
+        // fresh reset; configure RTC Calendar
+        RTC_CalendarConfig();
+    } else {
+        // RTC was previously set, so leave it alon
+        if(__HAL_RCC_GET_FLAG(RCC_FLAG_PORRST) != RESET) {
+            // power on reset occured
+            rtc_info |= 0x10000;
+        }
+        if(__HAL_RCC_GET_FLAG(RCC_FLAG_PINRST) != RESET) {
+            // external reset occured
+            rtc_info |= 0x20000;
+        }
+        // Clear source Reset Flag
+        __HAL_RCC_CLEAR_RESET_FLAGS();
     }
-    /* Check if Pin Reset flag is set */
-    if(__HAL_RCC_GET_FLAG(RCC_FLAG_PINRST) != RESET)
-    {
-      /* Turn on LED4: External reset occured */
-      //BSP_LED_On(LED4);
+}
+
+static void RTC_CalendarConfig(void) {
+    // set the date to 1st Jan 2014
+    RTC_DateTypeDef date;
+    date.Year = 0x14;
+    date.Month = RTC_MONTH_JANUARY;
+    date.Date = 0x01;
+    date.WeekDay = RTC_WEEKDAY_WEDNESDAY;
+
+    if(HAL_RTC_SetDate(&RTCHandle, &date, FORMAT_BCD) != HAL_OK) {
+        // init error
+        return;
     }
-    /* Clear source Reset Flag */
-    __HAL_RCC_CLEAR_RESET_FLAGS();
-  }
 
-}
+    // set the time to 00:00:00
+    RTC_TimeTypeDef time;
+    time.Hours = 0x00;
+    time.Minutes = 0x00;
+    time.Seconds = 0x00;
+    time.TimeFormat = RTC_HOURFORMAT12_AM;
+    time.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
+    time.StoreOperation = RTC_STOREOPERATION_RESET;
+
+    if (HAL_RTC_SetTime(&RTCHandle, &time, FORMAT_BCD) != HAL_OK) {
+        // init error
+        return;
+    }
 
-static void RTC_CalendarConfig(void)
-{
-  RTC_DateTypeDef sdatestructure;
-  RTC_TimeTypeDef stimestructure;
-    
-  /*##-1- Configure the Date #################################################*/
-  /* Set Date: Tuesday February 18th 2014 */
-  sdatestructure.Year = 0x14;
-  sdatestructure.Month = RTC_MONTH_FEBRUARY;
-  sdatestructure.Date = 0x18;
-  sdatestructure.WeekDay = RTC_WEEKDAY_TUESDAY;
-  
-  if(HAL_RTC_SetDate(&RTCHandle,&sdatestructure,FORMAT_BCD) != HAL_OK)
-  {
-    /* Initialization Error */
-    //Error_Handler(); 
-    return;
-  } 
-  
-  /*##-2- Configure the Time #################################################*/
-  /* Set Time: 02:00:00 */
-  stimestructure.Hours = 0x02;
-  stimestructure.Minutes = 0x00;
-  stimestructure.Seconds = 0x00;
-  stimestructure.TimeFormat = RTC_HOURFORMAT12_AM;
-  stimestructure.DayLightSaving = RTC_DAYLIGHTSAVING_NONE ;
-  stimestructure.StoreOperation = RTC_STOREOPERATION_RESET;
-  
-  if(HAL_RTC_SetTime(&RTCHandle,&stimestructure,FORMAT_BCD) != HAL_OK)
-  {
-    /* Initialization Error */
-    //Error_Handler(); 
-    return;
-  }
-  
-  /*##-3- Writes a data in a RTC Backup data Register0 #######################*/
-  HAL_RTCEx_BKUPWrite(&RTCHandle,RTC_BKP_DR0,0x32F2);  
+    // write data to indicate the RTC has been set
+    HAL_RTCEx_BKUPWrite(&RTCHandle, RTC_BKP_DR0, 0x32f2);
 }
 
 /******************************************************************************/