rtc prescaler divider set/get in case of stm32F1

Using the stm32F1 existing functions to write/read the
RTC prescaler registers (hold by the prediv var).
In that case only the 1st is considered.

Signed-off-by: Francois Ramu <francois.ramu@st.com>

Author: FRASTM

src/rtc.c

@@ -66,6 +66,8 @@ static uint8_t HSEDiv = 0;
 static uint8_t predivSync_bits = 0xFF;
 static int8_t predivAsync = -1;
 static int16_t predivSync = -1;
+#else
+static int32_t prediv = -1;
 #endif /* !STM32F1xx */
 
 static hourFormat_t initFormat = HOUR_FORMAT_12;
@@ -210,7 +212,7 @@ static void RTC_initClock(sourceClock_t source)
   * @param synch: synchronous prescaler value in range 0 - PREDIVS_MAX
   * @retval None
   */
-void RTC_setPrediv(int8_t asynch, int16_t synch)
+void RTC_setPrediv(int32_t asynch, int16_t synch)
 {
 #if !defined(STM32F1xx)
   if ((asynch >= -1) && ((uint32_t)asynch <= PREDIVA_MAX) && \
@@ -222,8 +224,11 @@ void RTC_setPrediv(int8_t asynch, int16_t synch)
   }
   predivSync_bits = (uint8_t)_log2(predivSync) + 1;
 #else
-  UNUSED(asynch);
+  /* the synch param is not used there */
   UNUSED(synch);
+  /* set the prescaler for a stm32F1 (value is hold by 1st param) */
+  prediv = (int32_t)asynch;
+  LL_RTC_SetAsynchPrescaler(RTC, asynch);
 #endif /* !STM32F1xx */
 }
 
@@ -234,7 +239,7 @@ void RTC_setPrediv(int8_t asynch, int16_t synch)
   * @param synch: pointer where return synchronous prescaler value.
   * @retval None
   */
-void RTC_getPrediv(int8_t *asynch, int16_t *synch)
+void RTC_getPrediv(int32_t *asynch, int16_t *synch)
 {
 #if !defined(STM32F1xx)
   if ((predivAsync == -1) || (predivSync == -1)) {
@@ -246,8 +251,11 @@ void RTC_getPrediv(int8_t *asynch, int16_t *synch)
   }
   predivSync_bits = (uint8_t)_log2(predivSync) + 1;
 #else
-  UNUSED(asynch);
+  /* the synch param is not used there */
   UNUSED(synch);
+  /* get the prescaler for a stm32F1 (value is hold by 1st param)*/
+  prediv = (int32_t)LL_RTC_GetDivider(RTC);
+  *asynch = prediv;
 #endif /* !STM32F1xx */
 }
 

src/rtc.h

@@ -136,8 +136,8 @@ static uint32_t RTC_getSource(void) {
 /* Exported functions ------------------------------------------------------- */
 void RTC_SetClockSource(sourceClock_t source);
 
-void RTC_getPrediv(int8_t *asynch, int16_t *synch);
-void RTC_setPrediv(int8_t asynch, int16_t synch);
+void RTC_getPrediv(int32_t *asynch, int16_t *synch);
+void RTC_setPrediv(int32_t asynch, int16_t synch);
 
 void RTC_init(hourFormat_t format, sourceClock_t source, bool reset);
 void RTC_DeInit(void);