File content as of revision 39:cb0e5a76ab15:

/*
 / _____)             _              | |
( (____  _____ ____ _| |_ _____  ____| |__
 \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 _____) ) ____| | | || |_| ____( (___| | | |
(______/|_____)_|_|_| \__)_____)\____)_| |_|
    (C)2013 Semtech

Description: MCU RTC timer

License: Revised BSD License, see LICENSE.TXT file include in the project

Maintainer: Miguel Luis and Gregory Cristian
*/
/*******************************************************************************
 * @file    hw_rtc.c
 * @author  MCD Application Team
 * @version V1.1.4
 * @date    08-January-2018
 * @brief   driver for RTC
 ******************************************************************************
 * @attention
 *
 * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics International N.V.
 * All rights reserved.</center></h2>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted, provided that the following conditions are met:
 *
 * 1. Redistribution of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of STMicroelectronics nor the names of other
 *    contributors to this software may be used to endorse or promote products
 *    derived from this software without specific written permission.
 * 4. This software, including modifications and/or derivative works of this
 *    software, must execute solely and exclusively on microcontroller or
 *    microprocessor devices manufactured by or for STMicroelectronics.
 * 5. Redistribution and use of this software other than as permitted under
 *    this license is void and will automatically terminate your rights under
 *    this license.
 *
 * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY
 * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT
 * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************
 */

/* Includes ------------------------------------------------------------------*/
#include "hw.h"
#include "low_power_manager.h"

/* Private typedef -----------------------------------------------------------*/
typedef struct
{
  uint32_t Rtc_Time; /* Reference time */
  
  RTC_TimeTypeDef RTC_Calndr_Time; /* Reference time in calendar format */

  RTC_DateTypeDef RTC_Calndr_Date; /* Reference date in calendar format */
  
} RtcTimerContext_t;

/* Private define ------------------------------------------------------------*/

/* MCU Wake Up Time */
#define MIN_ALARM_DELAY            3U /* in ticks */

/* subsecond number of bits */
#define N_PREDIV_S                10U

/* Synchronous prediv  */
#define PREDIV_S                  ((1<<N_PREDIV_S)-1)

/* Asynchronous prediv   */
#define PREDIV_A                  (1<<(15-N_PREDIV_S))-1

/* Sub-second mask definition  */
#if  (N_PREDIV_S == 10)
#define HW_RTC_ALARMSUBSECONDMASK RTC_ALARMSUBSECONDMASK_SS14_10
#else
#error "Please define HW_RTC_ALARMSUBSECONDMASK"
#endif

/* RTC Time base in us */
#define USEC_NUMBER               1000000U
#define MSEC_NUMBER               (USEC_NUMBER/1000)
#define RTC_ALARM_TIME_BASE       (USEC_NUMBER>>N_PREDIV_S)

#define COMMON_FACTOR             3U
#define CONV_NUMER                (MSEC_NUMBER>>COMMON_FACTOR)
#define CONV_DENOM                (1<<(N_PREDIV_S-COMMON_FACTOR))


/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/*!
 * \brief Indicates if the RTC is already Initialized or not
 */
static bool HW_RTC_Initalized = false;

/*!
 * \brief compensates MCU wakeup time
 */
 
static bool McuWakeUpTimeInitialized = false;

/*!
 * \brief compensates MCU wakeup time
 */
 
static int16_t McuWakeUpTimeCal = 0;

/*!
 * Number of seconds in a minute
 */
static const uint8_t SecondsInMinute = 60;

/*!
 * Number of seconds in an hour
 */
static const uint16_t SecondsInHour = 3600;

/*!
 * Number of seconds in a day
 */
static const uint32_t SecondsInDay = 86400;

/*!
 * Number of hours in a day
 */
static const uint8_t HoursInDay = 24;

/*!
 * Number of days in a standard year
 */
static const uint16_t DaysInYear = 365;

/*!
 * Number of days in a leap year
 */
static const uint16_t DaysInLeapYear = 366;

/*!
 * Number of days in each month on a normal year
 */
static const uint8_t DaysInMonth[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

/*!
 * Number of days in each month on a leap year
 */
static const uint8_t DaysInMonthLeapYear[] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static RTC_HandleTypeDef RtcHandle={0};

static RTC_AlarmTypeDef RTC_AlarmStructure;

/*!
 * Keep the value of the RTC timer when the RTC alarm is set
 * Set with the HW_RTC_SetTimerContext function
 * Value is kept as a Reference to calculate alarm
 */
static RtcTimerContext_t RtcTimerContext;

/* Private function prototypes -----------------------------------------------*/

static void HW_RTC_SetConfig( void );

static void HW_RTC_SetAlarmConfig( void );

static void HW_RTC_StartWakeUpAlarm( uint32_t timeoutValue );

static uint32_t HW_RTC_GetCalendarValue(  RTC_DateTypeDef* RTC_DateStruct, RTC_TimeTypeDef* RTC_TimeStruct  );

/* Exported functions ---------------------------------------------------------*/

/*!
 * @brief Initializes the RTC timer
 * @note The timer is based on the RTC
 * @param none
 * @retval none
 */
void HW_RTC_Init( void )
{
  if( HW_RTC_Initalized == false )
  {
    HW_RTC_SetConfig( );
    HW_RTC_SetAlarmConfig( );
    HW_RTC_SetTimerContext( );
    HW_RTC_Initalized = true;
  }
}

/*!
 * @brief Configures the RTC timer
 * @note The timer is based on the RTC
 * @param none
 * @retval none
 */
static void HW_RTC_SetConfig( void )
{
  RTC_TimeTypeDef RTC_TimeStruct;
  RTC_DateTypeDef RTC_DateStruct;

  RtcHandle.Instance = RTC;

  RtcHandle.Init.HourFormat = RTC_HOURFORMAT_24;
  RtcHandle.Init.AsynchPrediv = PREDIV_A; /* RTC_ASYNCH_PREDIV; */
  RtcHandle.Init.SynchPrediv = PREDIV_S; /* RTC_SYNCH_PREDIV; */
  RtcHandle.Init.OutPut = RTC_OUTPUT;
  RtcHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
  RtcHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;

  HAL_RTC_Init( &RtcHandle );
  
  /*Monday 1st January 2016*/
  RTC_DateStruct.Year = 16;
  RTC_DateStruct.Month = RTC_MONTH_JANUARY;
  RTC_DateStruct.Date = 1;
  RTC_DateStruct.WeekDay = RTC_WEEKDAY_MONDAY;
  HAL_RTC_SetDate(&RtcHandle , &RTC_DateStruct, RTC_FORMAT_BIN);
  
  /*at 0:0:0*/
  RTC_TimeStruct.Hours = 0;
  RTC_TimeStruct.Minutes = 0;

  RTC_TimeStruct.Seconds = 0;
  RTC_TimeStruct.TimeFormat = 0;
  RTC_TimeStruct.SubSeconds = 0;
  RTC_TimeStruct.StoreOperation = RTC_DAYLIGHTSAVING_NONE;
  RTC_TimeStruct.DayLightSaving = RTC_STOREOPERATION_RESET;
  
  HAL_RTC_SetTime(&RtcHandle , &RTC_TimeStruct, RTC_FORMAT_BIN);
  
 /*Enable Direct Read of the calendar registers (not through Shadow) */
  HAL_RTCEx_EnableBypassShadow(&RtcHandle);
}

/*!
 * @brief calculates the wake up time between wake up and mcu start
 * @note resolution in RTC_ALARM_TIME_BASE in timer ticks
 * @param none
 * @retval none
 */
void HW_RTC_setMcuWakeUpTime( void )
{
  RTC_TimeTypeDef RTC_TimeStruct;
  RTC_DateTypeDef RTC_DateStruct;
  
  uint32_t now, hit;
  int16_t McuWakeUpTime;
  
  if ((McuWakeUpTimeInitialized == false) &&
      ( HAL_NVIC_GetPendingIRQ( RTC_Alarm_IRQn ) == 1))
  { /* warning: works ok if now is below 30 days
       it is ok since it's done once at first alarm wake-up*/
    McuWakeUpTimeInitialized = true;
    now = HW_RTC_GetCalendarValue( &RTC_DateStruct, &RTC_TimeStruct );

    DBG_GPIO_SET(GPIOB, GPIO_PIN_13);
    DBG_GPIO_RST(GPIOB, GPIO_PIN_13);
    HAL_RTC_GetAlarm(&RtcHandle, &RTC_AlarmStructure, RTC_ALARM_A, RTC_FORMAT_BIN );
    hit = RTC_AlarmStructure.AlarmTime.Seconds+
          60*(RTC_AlarmStructure.AlarmTime.Minutes+
          60*(RTC_AlarmStructure.AlarmTime.Hours+
          24*(RTC_AlarmStructure.AlarmDateWeekDay)));
    hit = ( hit << N_PREDIV_S ) + (PREDIV_S - RTC_AlarmStructure.AlarmTime.SubSeconds);
      
    McuWakeUpTime = (int16_t) ((now-hit));
    McuWakeUpTimeCal += McuWakeUpTime;
    DBG_PRINTF("Cal=%d, %d\n",McuWakeUpTimeCal, McuWakeUpTime);
  }
}

int16_t HW_RTC_getMcuWakeUpTime( void )
{
  return McuWakeUpTimeCal;
}

/*!
 * @brief returns the wake up time in ticks
 * @param none
 * @retval wake up time in ticks
 */
uint32_t HW_RTC_GetMinimumTimeout( void )
{
  return( MIN_ALARM_DELAY );
}

/*!
 * @brief converts time in ms to time in ticks
 * @param [IN] time in milliseconds
 * @retval returns time in timer ticks
 */
uint32_t HW_RTC_ms2Tick( uint32_t timeMicroSec )
{
/*return( ( timeMicroSec / RTC_ALARM_TIME_BASE ) ); */
  return ( uint32_t) ( ( ((uint64_t)timeMicroSec) * CONV_DENOM ) / CONV_NUMER );
}

/*!
 * @brief converts time in ticks to time in ms
 * @param [IN] time in timer ticks
 * @retval returns time in milliseconds
 */
uint32_t HW_RTC_Tick2ms( uint32_t tick )
{
/*return( ( timeMicroSec * RTC_ALARM_TIME_BASE ) ); */
  return  ( ( (uint64_t)( tick )* CONV_NUMER ) / CONV_DENOM );
}

/*!
 * @brief Set the alarm
 * @note The alarm is set at now (read in this funtion) + timeout
 * @param timeout Duration of the Timer ticks
 */
void HW_RTC_SetAlarm( uint32_t timeout )
{
  /* we don't go in Low Power mode for timeout below MIN_ALARM_DELAY */
  if ( (MIN_ALARM_DELAY + McuWakeUpTimeCal ) < ((timeout - HW_RTC_GetTimerElapsedTime( ) )) )
  {
    LPM_SetStopMode(LPM_RTC_Id , LPM_Enable );
  }
  else
  {
    LPM_SetStopMode(LPM_RTC_Id , LPM_Disable );
  }

  /*In case stop mode is required */
  if( LPM_GetMode() == LPM_StopMode )
  {
    timeout = timeout -  McuWakeUpTimeCal;
  }

  HW_RTC_StartWakeUpAlarm( timeout );
}

/*!
 * @brief Get the RTC timer elapsed time since the last Alarm was set
 * @param none
 * @retval RTC Elapsed time in ticks
 */
uint32_t HW_RTC_GetTimerElapsedTime( void )
{
  RTC_TimeTypeDef RTC_TimeStruct;
  RTC_DateTypeDef RTC_DateStruct;
  
  uint32_t CalendarValue = HW_RTC_GetCalendarValue(&RTC_DateStruct, &RTC_TimeStruct );

  return( ( uint32_t )( CalendarValue - RtcTimerContext.Rtc_Time ));
}

/*!
 * @brief Get the RTC timer value
 * @param none
 * @retval RTC Timer value in ticks
 */
uint32_t HW_RTC_GetTimerValue( void )
{
  RTC_TimeTypeDef RTC_TimeStruct;
  RTC_DateTypeDef RTC_DateStruct;
  
  uint32_t CalendarValue = (uint32_t) HW_RTC_GetCalendarValue(&RTC_DateStruct, &RTC_TimeStruct );

  return( CalendarValue );
}

/*!
 * @brief Stop the Alarm
 * @param none
 * @retval none
 */
void HW_RTC_StopAlarm( void )
{

  /* Clear RTC Alarm Flag */
  __HAL_RTC_ALARM_CLEAR_FLAG( &RtcHandle, RTC_FLAG_ALRAF);

  /* Disable the Alarm A interrupt */

  HAL_RTC_DeactivateAlarm(&RtcHandle, RTC_ALARM_A );
}

/*!
 * @brief RTC IRQ Handler on the RTC Alarm
 * @param none
 * @retval none
 */
void HW_RTC_IrqHandler ( void )
{
  RTC_HandleTypeDef* hrtc=&RtcHandle;
  /* enable low power at irq*/
  LPM_SetStopMode(LPM_RTC_Id , LPM_Enable );
  
    /* Get the AlarmA interrupt source enable status */
  if(__HAL_RTC_ALARM_GET_IT_SOURCE(hrtc, RTC_IT_ALRA) != RESET)
  {
    /* Get the pending status of the AlarmA Interrupt */
    if(__HAL_RTC_ALARM_GET_FLAG(hrtc, RTC_FLAG_ALRAF) != RESET)
    {
      /* Clear the AlarmA interrupt pending bit */
      __HAL_RTC_ALARM_CLEAR_FLAG(hrtc, RTC_FLAG_ALRAF); 
      /* Clear the EXTI's line Flag for RTC Alarm */
      __HAL_RTC_ALARM_EXTI_CLEAR_FLAG();
      /* AlarmA callback */
      HAL_RTC_AlarmAEventCallback(hrtc);
    }
  }
}


/*!
 * @brief a delay of delay ms by polling RTC
 * @param delay in ms
 * @retval none
 */
void HW_RTC_DelayMs( uint32_t delay )
{
  uint32_t delayValue = 0;
  uint32_t timeout = 0;

  delayValue = HW_RTC_ms2Tick( delay );

  /* Wait delay ms */
  timeout = HW_RTC_GetTimerValue( );
  while( ( ( HW_RTC_GetTimerValue( ) - timeout ) ) < delayValue )
  {
    __NOP( );
  }
}

/*!
 * @brief set Time Reference set also the RTC_DateStruct and RTC_TimeStruct
 * @param none
 * @retval Timer Value
 */
uint32_t HW_RTC_SetTimerContext( void )
{
  RtcTimerContext.Rtc_Time = HW_RTC_GetCalendarValue( &RtcTimerContext.RTC_Calndr_Date, &RtcTimerContext.RTC_Calndr_Time );
  return ( uint32_t ) RtcTimerContext.Rtc_Time;
}

/*!
 * @brief Get the RTC timer Reference
 * @param none
 * @retval Timer Value in  Ticks
 */
uint32_t HW_RTC_GetTimerContext( void )
{
  return (uint32_t) RtcTimerContext.Rtc_Time;
}
/* Private functions ---------------------------------------------------------*/

/*!
 * @brief configure alarm at init
 * @param none
 * @retval none
 */
static void HW_RTC_SetAlarmConfig( void )
{
  HAL_RTC_DeactivateAlarm(&RtcHandle, RTC_ALARM_A);
}

/*!
 * @brief start wake up alarm
 * @note  alarm in RtcTimerContext.Rtc_Time + timeoutValue
 * @param timeoutValue in ticks
 * @retval none
 */
static void HW_RTC_StartWakeUpAlarm( uint32_t timeoutValue )
{
  uint16_t rtcAlarmSubSeconds = 0;
  uint16_t rtcAlarmSeconds = 0;
  uint16_t rtcAlarmMinutes = 0;
  uint16_t rtcAlarmHours = 0;
  uint16_t rtcAlarmDays = 0;
  RTC_TimeTypeDef RTC_TimeStruct = RtcTimerContext.RTC_Calndr_Time;
  RTC_DateTypeDef RTC_DateStruct = RtcTimerContext.RTC_Calndr_Date;

  HW_RTC_StopAlarm( );
  DBG_GPIO_SET(GPIOB, GPIO_PIN_13);
  
  /*reverse counter */
  rtcAlarmSubSeconds =  PREDIV_S - RTC_TimeStruct.SubSeconds;
  rtcAlarmSubSeconds += ( timeoutValue & PREDIV_S);
  /* convert timeout  to seconds */
  timeoutValue >>= N_PREDIV_S;  /* convert timeout  in seconds */
  
  /*convert microsecs to RTC format and add to 'Now' */
  rtcAlarmDays =  RTC_DateStruct.Date;
  while (timeoutValue >= SecondsInDay)
  {
    timeoutValue -= SecondsInDay;
    rtcAlarmDays++;
  }
  
  /* calc hours */
  rtcAlarmHours = RTC_TimeStruct.Hours;
  while (timeoutValue >= SecondsInHour)
  {
    timeoutValue -= SecondsInHour;
    rtcAlarmHours++;
  }
  
  /* calc minutes */
  rtcAlarmMinutes = RTC_TimeStruct.Minutes;
  while (timeoutValue >= SecondsInMinute)
  {
    timeoutValue -= SecondsInMinute;
    rtcAlarmMinutes++;
  }
   
  /* calc seconds */
  rtcAlarmSeconds =  RTC_TimeStruct.Seconds + timeoutValue;

  /***** correct for modulo********/
  while (rtcAlarmSubSeconds >= (PREDIV_S+1))
  {
    rtcAlarmSubSeconds -= (PREDIV_S+1);
    rtcAlarmSeconds++;
  }
  
  while (rtcAlarmSeconds >= 60)
  { 
    rtcAlarmSeconds -= 60;
    rtcAlarmMinutes++;
  }

  while (rtcAlarmMinutes >= 60)
  {
    rtcAlarmMinutes -= 60;
    rtcAlarmHours++;
  }
  
  while (rtcAlarmHours >= HoursInDay)
  {
    rtcAlarmHours -= HoursInDay;
    rtcAlarmDays++;
  }

  if( RTC_DateStruct.Year % 4 == 0 ) 
  {
    if( rtcAlarmDays > DaysInMonthLeapYear[ RTC_DateStruct.Month - 1 ] )    
    {
      rtcAlarmDays = rtcAlarmDays % DaysInMonthLeapYear[ RTC_DateStruct.Month - 1 ];
    }
  }
  else
  {
    if( rtcAlarmDays > DaysInMonth[ RTC_DateStruct.Month - 1 ] )    
    {   
      rtcAlarmDays = rtcAlarmDays % DaysInMonth[ RTC_DateStruct.Month - 1 ];
    }
  }

  /* Set RTC_AlarmStructure with calculated values*/
  RTC_AlarmStructure.AlarmTime.SubSeconds = PREDIV_S-rtcAlarmSubSeconds;
  RTC_AlarmStructure.AlarmSubSecondMask  = HW_RTC_ALARMSUBSECONDMASK; 
  RTC_AlarmStructure.AlarmTime.Seconds = rtcAlarmSeconds;
  RTC_AlarmStructure.AlarmTime.Minutes = rtcAlarmMinutes;
  RTC_AlarmStructure.AlarmTime.Hours   = rtcAlarmHours;
  RTC_AlarmStructure.AlarmDateWeekDay    = ( uint8_t )rtcAlarmDays;
  RTC_AlarmStructure.AlarmTime.TimeFormat   = RTC_TimeStruct.TimeFormat;
  RTC_AlarmStructure.AlarmDateWeekDaySel   = RTC_ALARMDATEWEEKDAYSEL_DATE; 
  RTC_AlarmStructure.AlarmMask       = RTC_ALARMMASK_NONE;
  RTC_AlarmStructure.Alarm = RTC_ALARM_A;
  RTC_AlarmStructure.AlarmTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
  RTC_AlarmStructure.AlarmTime.StoreOperation = RTC_STOREOPERATION_RESET;
  
  /* Set RTC_Alarm */
  HAL_RTC_SetAlarm_IT( &RtcHandle, &RTC_AlarmStructure, RTC_FORMAT_BIN );
  
  /* Debug Printf*/
  DBG( HW_RTC_GetCalendarValue( &RTC_DateStruct, &RTC_TimeStruct ); );
  //DBG_PRINTF("it's %d:%d:%d:%d ", RTC_TimeStruct.Hours, RTC_TimeStruct.Minutes, RTC_TimeStruct.Seconds, (uint16_t)((PREDIV_S - RTC_TimeStruct.SubSeconds)*1000)>>N_PREDIV_S);
  //DBG_PRINTF("WU@ %d:%d:%d:%d\n", rtcAlarmHours, rtcAlarmMinutes, rtcAlarmSeconds, (rtcAlarmSubSeconds*1000)>>N_PREDIV_S );
  
  DBG_GPIO_RST(GPIOB, GPIO_PIN_13);
}


/*!
 * @brief get current time from calendar in ticks
 * @param pointer to RTC_DateStruct
 * @param pointer to RTC_TimeStruct
 * @retval time in ticks
 */
static uint32_t HW_RTC_GetCalendarValue( RTC_DateTypeDef* RTC_DateStruct, RTC_TimeTypeDef* RTC_TimeStruct )
{
  uint32_t calendarValue = 0;
  uint32_t i = 0;
  uint32_t first_read;
  
  /* Get Time and Date*/
  HAL_RTC_GetTime( &RtcHandle, RTC_TimeStruct, RTC_FORMAT_BIN );
 
   /* make sure it is correct due to asynchronus nature of RTC*/
  do {
    first_read = RTC_TimeStruct->SubSeconds;
    HAL_RTC_GetDate( &RtcHandle, RTC_DateStruct, RTC_FORMAT_BIN );
    HAL_RTC_GetTime( &RtcHandle, RTC_TimeStruct, RTC_FORMAT_BIN );
  } while (first_read != RTC_TimeStruct->SubSeconds);
 
  /* years (calc valid up to year 2099)*/
  for( i = 0; i < RTC_DateStruct->Year; i++ )
  {
    if( (i % 4) == 0 )
    {
      calendarValue += DaysInLeapYear * SecondsInDay;
    }
    else
    {
      calendarValue += DaysInYear * SecondsInDay;
    }
  }

  /* months (calc valid up to year 2099)*/
  if(( (RTC_DateStruct->Year % 4) == 0 ) )
  {
    for( i = 0; i < ( RTC_DateStruct->Month - 1 ); i++ )
    {
      calendarValue += DaysInMonthLeapYear[i] * SecondsInDay;
    }
  }
  else
  {
    for( i = 0;  i < ( RTC_DateStruct->Month - 1 ); i++ )
    {
      calendarValue += DaysInMonth[i] * SecondsInDay;
    }
  }

  /* days */
  calendarValue += ( ( uint32_t )RTC_TimeStruct->Seconds + 
                     ( ( uint32_t )RTC_TimeStruct->Minutes * SecondsInMinute ) +
                     ( ( uint32_t )RTC_TimeStruct->Hours * SecondsInHour ) + 
                     ( ( uint32_t )( RTC_DateStruct->Date * SecondsInDay ) ) );
  
  calendarValue = (calendarValue<<N_PREDIV_S) + ( PREDIV_S - RTC_TimeStruct->SubSeconds);

  return( calendarValue );
}


/**
  * @brief RTC MSP Initialization
  *        This function configures the hardware resources used in this example:
  *           - Peripheral's clock enable
  * @param hrtc: RTC handle pointer
  * @note  Care must be taken when HAL_RCCEx_PeriphCLKConfig() is used to select
  *        the RTC clock source; in this case the Backup domain will be reset in
  *        order to modify the RTC Clock source, as consequence RTC registers (including
  *        the backup registers) and RCC_CSR register are set to their reset values.
  * @retval None
  */
void HAL_RTC_MspInit(RTC_HandleTypeDef *hrtc)
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_PeriphCLKInitTypeDef  PeriphClkInitStruct;

  /*##-1- Configue the RTC clock soucre ######################################*/
  /* -a- Enable LSE Oscillator */
  RCC_OscInitStruct.OscillatorType =  RCC_OSCILLATORTYPE_LSE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
      DBG_PRINTF("Error_Handler\n\r");
      while(1);
  }

  /* -b- Select LSI as RTC clock source */
  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RTC;
  PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
  if(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
  {
      DBG_PRINTF("Error_Handler\n\r");
      while(1);
  }

  /*##-2- Enable the RTC peripheral Clock ####################################*/
  /* Enable RTC Clock */
  __HAL_RCC_RTC_ENABLE();

  /*##-3- Configure the NVIC for RTC Alarm ###################################*/
  HAL_NVIC_SetPriority(RTC_Alarm_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(RTC_Alarm_IRQn);
}

/**
  * @brief RTC MSP De-Initialization
  *        This function freeze the hardware resources used in this example:
  *          - Disable the Peripheral's clock
  * @param hrtc: RTC handle pointer
  * @retval None
  */
void HAL_RTC_MspDeInit(RTC_HandleTypeDef *hrtc)
{
  /* Reset peripherals */
  __HAL_RCC_RTC_DISABLE();
}
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/