feat: add a parameter to set binary mode

This is valid when the RTC_BINARY_MIX mode exists in the RTC
(bitfield in the RTC ICSR register)
Set the RTC mode through a setBinaryMode function to be called
before begin.

Signed-off-by: Francois Ramu <francois.ramu@st.com>
Co-authored-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

src/STM32RTC.cpp

@@ -63,6 +63,7 @@ void STM32RTC::begin(bool resetTime, Hour_Format format)
 
   _format = format;
   reinit = RTC_init((format == HOUR_12) ? HOUR_FORMAT_12 : HOUR_FORMAT_24,
+                    (_mode == MODE_MIX) ? ::MODE_BINARY_MIX : ((_mode == MODE_BIN) ? ::MODE_BINARY_ONLY : ::MODE_BINARY_NONE),
                     (_clockSource == LSE_CLOCK) ? ::LSE_CLOCK :
                     (_clockSource == HSE_CLOCK) ? ::HSE_CLOCK : ::LSI_CLOCK
                     , resetTime);
@@ -136,6 +137,26 @@ void STM32RTC::setClockSource(Source_Clock source, uint32_t predivA, uint32_t pr
   RTC_setPrediv(predivA, predivS);
 }
 
+/**
+  * @brief get the Binary Mode.
+  * @retval mode: MODE_BCD, MODE_BIN or MODE_MIX
+  */
+STM32RTC::Binary_Mode STM32RTC::getBinaryMode(void)
+{
+  return _mode;
+}
+
+/**
+  * @brief set the Binary Mode. By default MODE_BCD is selected. This
+  *        method must be called before begin().
+  * @param mode: the RTC mode: MODE_BCD, MODE_BIN or MODE_MIX
+  * @retval None
+  */
+void STM32RTC::setBinaryMode(Binary_Mode mode)
+{
+  _mode = mode;
+}
+
 /**
   * @brief  get user (a)synchronous prescaler values if set else computed
   *         ones for the current clock source.

src/STM32RTC.h

@@ -85,6 +85,12 @@ class STM32RTC {
       PM = HOUR_PM
     };
 
+    enum Binary_Mode : uint8_t {
+      MODE_BCD = MODE_BINARY_NONE, /* not used */
+      MODE_BIN = MODE_BINARY_ONLY,
+      MODE_MIX = MODE_BINARY_MIX
+    };
+
     enum Alarm_Match : uint8_t {
       MATCH_OFF          = OFF_MSK,                          // Never
       MATCH_SS           = SS_MSK,                           // Every Minute
@@ -130,6 +136,9 @@ class STM32RTC {
     void getPrediv(uint32_t *predivA, uint32_t *predivS);
     void setPrediv(uint32_t predivA, uint32_t predivS);
 
+    Binary_Mode getBinaryMode(void);
+    void setBinaryMode(Binary_Mode mode);
+
     void enableAlarm(Alarm_Match match, Alarm name = ALARM_A);
     void disableAlarm(Alarm name = ALARM_A);
 
@@ -227,14 +236,15 @@ class STM32RTC {
     friend class STM32LowPower;
 
   private:
-    STM32RTC(void): _clockSource(LSI_CLOCK)
+    STM32RTC(void): _mode(MODE_BCD), _clockSource(LSI_CLOCK)
     {
       setClockSource(_clockSource);
     }
 
     static bool _timeSet;
 
     Hour_Format _format;
+    Binary_Mode _mode;
     AM_PM       _hoursPeriod;
     uint8_t     _hours;
     uint8_t     _minutes;

src/rtc.c

@@ -79,12 +79,16 @@ static uint32_t predivAsync = RTC_AUTO_1_SECOND;
 #endif /* !STM32F1xx */
 
 static hourFormat_t initFormat = HOUR_FORMAT_12;
+static binaryMode_t initMode = MODE_BINARY_NONE;
 
 /* Private function prototypes -----------------------------------------------*/
 static void RTC_initClock(sourceClock_t source);
 #if !defined(STM32F1xx)
 static void RTC_computePrediv(uint32_t *asynch, uint32_t *synch);
 #endif /* !STM32F1xx */
+#if defined(RTC_BINARY_NONE)
+static void RTC_BinaryConf(binaryMode_t mode);
+#endif
 
 static inline int _log2(int x)
 {
@@ -334,17 +338,49 @@ static void RTC_computePrediv(uint32_t *asynch, uint32_t *synch)
 }
 #endif /* !STM32F1xx */
 
+#if defined(RTC_BINARY_NONE)
+static void RTC_BinaryConf(binaryMode_t mode)
+{
+  RtcHandle.Init.BinMode = (mode == MODE_BINARY_MIX) ? RTC_BINARY_MIX : ((mode == MODE_BINARY_ONLY) ? RTC_BINARY_ONLY : RTC_BINARY_NONE);
+  if (RtcHandle.Init.BinMode == RTC_BINARY_MIX) {
+    /* Configure the 1s BCD calendar increment */
+
+    uint32_t inc = 1 / (1.0 / ((float)clkVal / (float)(predivAsync + 1.0)));
+    if (inc <= 256) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_0;
+    } else if (inc < (256 << 1)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_1;
+    } else if (inc < (256 << 2)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_2;
+    } else if (inc < (256 << 3)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_3;
+    } else if (inc < (256 << 4)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_4;
+    } else if (inc < (256 << 5)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_5;
+    } else if (inc < (256 << 6)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_6;
+    } else if (inc < (256 << 7)) {
+      RtcHandle.Init.BinMixBcdU = RTC_BINARY_MIX_BCDU_7;
+    } else {
+      Error_Handler();
+    }
+  }
+}
+#endif /* RTC_BINARY_NONE */
+
 /**
   * @brief RTC Initialization
   *        This function configures the RTC time and calendar. By default, the
   *        RTC is set to the 1st January 2001
   *        Note: year 2000 is invalid as it is the hardware reset value and doesn't raise INITS flag
   * @param format: enable the RTC in 12 or 24 hours mode
+  * @param mode: enable the RTC in BCD or Mix or Binary mode
   * @param source: RTC clock source: LSE, LSI or HSE
   * @param reset: force RTC reset, even if previously configured
   * @retval True if RTC is reinitialized, else false
   */
-bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset)
+bool RTC_init(hourFormat_t format, binaryMode_t mode, sourceClock_t source, bool reset)
 {
   bool reinit = false;
   hourAM_PM_t period = HOUR_AM, alarmPeriod = HOUR_AM;
@@ -360,7 +396,7 @@ bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset)
 #endif
 
   initFormat = format;
-
+  initMode = mode;
   /* Ensure all RtcHandle properly set */
   RtcHandle.Instance = RTC;
 #if defined(STM32F1xx)
@@ -409,7 +445,10 @@ bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset)
     // Init RTC clock
     RTC_initClock(source);
     RTC_getPrediv(&(RtcHandle.Init.AsynchPrediv), &(RtcHandle.Init.SynchPrediv));
-#endif // STM32F1xx
+#if defined(RTC_BINARY_NONE)
+    RTC_BinaryConf(mode);
+#endif /* RTC_BINARY_NONE */
+#endif  // STM32F1xx
 
     HAL_RTC_Init(&RtcHandle);
     // Default: saturday 1st of January 2001
@@ -471,6 +510,9 @@ bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset)
 #else
       RTC_getPrediv(&(RtcHandle.Init.AsynchPrediv), &(RtcHandle.Init.SynchPrediv));
 #endif
+#if defined(RTC_BINARY_NONE)
+      RTC_BinaryConf(mode);
+#endif /* RTC_BINARY_NONE */
       HAL_RTC_Init(&RtcHandle);
       // Restore config
       RTC_SetTime(hours, minutes, seconds, subSeconds, period);
@@ -493,6 +535,9 @@ bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset)
 #else
       RTC_getPrediv(&(RtcHandle.Init.AsynchPrediv), &(RtcHandle.Init.SynchPrediv));
 #endif
+#if defined(RTC_BINARY_NONE)
+      RTC_BinaryConf(mode);
+#endif /* RTC_BINARY_NONE */
 #if defined(STM32F1xx)
       memcpy(&RtcHandle.DateToUpdate, &BackupDate, 4);
       /* Update date automatically by calling HAL_RTC_GetDate */

src/rtc.h

@@ -55,6 +55,12 @@ typedef enum {
   HOUR_FORMAT_24
 } hourFormat_t;
 
+typedef enum {
+  MODE_BINARY_NONE, /* BCD only */
+  MODE_BINARY_ONLY,
+  MODE_BINARY_MIX
+} binaryMode_t;
+
 typedef enum {
   HOUR_AM,
   HOUR_PM
@@ -169,7 +175,7 @@ void RTC_SetClockSource(sourceClock_t source);
 void RTC_getPrediv(uint32_t *asynch, uint32_t *synch);
 void RTC_setPrediv(uint32_t asynch, uint32_t synch);
 
-bool RTC_init(hourFormat_t format, sourceClock_t source, bool reset);
+bool RTC_init(hourFormat_t format, binaryMode_t mode, sourceClock_t source, bool reset);
 void RTC_DeInit(bool reset_cb);
 bool RTC_IsConfigured(void);