Add get/set prediv methods

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

Author: fpistm

src/STM32RTC.cpp

@@ -117,9 +117,37 @@ void STM32RTC::setClockSource(RTC_Source_Clock source)
 {
  if(IS_CLOCK_SOURCE(source)) {
  _clockSource = source;
+ RTC_SetClockSource((_clockSource == RTC_LSE_CLOCK)? LSE_CLOCK:
+ (_clockSource == RTC_HSE_CLOCK)? HSE_CLOCK : LSI_CLOCK);
+ }
+}
+
+/**
+ * @brief get user (a)synchronous prescaler values if set else computed
+ * ones for the current clock source.
+ * @param predivA: pointer to the current Asynchronous prescaler value
+ * @param predivS: pointer to the current Synchronous prescaler value
+ * @retval None
+ */
+void STM32RTC::getPrediv(int8_t *predivA, int16_t *predivS)
+{
+ if((predivA != NULL) && (predivS != NULL)) {
+ RTC_getPrediv(predivA, predivS);
  }
 }
 
+/**
+ * @brief set user (a)synchronous prescalers value.
+ * @note This method must be called before begin().
+ * @param predivA: Asynchronous prescaler value. Reset value: -1
+ * @param predivS: Synchronous prescaler value. Reset value: -1
+ * @retval None
+ */
+void STM32RTC::setPrediv(int8_t predivA, int16_t predivS)
+{
+ RTC_setPrediv(predivA, predivS);
+}
+
 /**
  * @brief enable the RTC alarm.
  * @param match: Alarm_Match configuration

src/STM32RTC.h

@@ -166,6 +166,9 @@ class STM32RTC {
  void setY2kEpoch(uint32_t ts);
  void setAlarmEpoch(uint32_t ts, Alarm_Match match = MATCH_DHHMMSS);
 
+ void getPrediv(int8_t *predivA, int16_t *predivS);
+ void setPrediv(int8_t predivA, int16_t predivS);
+
  bool isConfigured(void) {
  return _configured;
  }