#include "time.h"
#include "stm32f0xx_conf.h"

/* Uncomment the corresponding line to select the RTC Clock source */
#define RTC_CLOCK_SOURCE_LSE   /* LSE used as RTC source clock */
//#define RTC_CLOCK_SOURCE_LSI  // LSI used as RTC source clock. The RTC Clock
                                // may varies due to LSI frequency dispersion

#define BKP_VALUE    0x32F0
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
__IO uint32_t AsynchPrediv = 0, SynchPrediv = 0;

/* Private function prototypes -----------------------------------------------*/
static void RTC_Config(void);
static void RTC_TimeRegulate(void);


// - калибровку RTC как делать?


// ----------------------------------------------------------------------------
//
// ----------------------------------------------------------------------------
void TimeInit (void)
{
  RTC_InitTypeDef RTC_InitStructure;

  if (RTC_ReadBackupRegister(RTC_BKP_DR0) != BKP_VALUE)
  //if (SynchPrediv == 0)
  {
    /* RTC configuration  */
    RTC_Config();

    /* Configure the RTC data register and RTC prescaler */
    RTC_InitStructure.RTC_AsynchPrediv = AsynchPrediv;
    RTC_InitStructure.RTC_SynchPrediv = SynchPrediv;
    RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24;

    /* Check on RTC init */
    if (RTC_Init(&RTC_InitStructure) == ERROR)
    {
     // printf("\n\r        /!\\***** RTC Prescaler Config failed ********/!\\ \n\r");
    }

    /* Configure the time register */
    RTC_TimeRegulate();
  }
  else
  {
    /* Check if the Power On Reset flag is set */
    if (RCC_GetFlagStatus(RCC_FLAG_PORRST) != RESET)
    {
      //printf("\r\n Power On Reset occurred....\n\r");
    }
    /* Check if the Pin Reset flag is set */
    else if (RCC_GetFlagStatus(RCC_FLAG_PINRST) != RESET)
    {
     // printf("\r\n External Reset occurred....\n\r");
    }

    //printf("\n\r No need to configure RTC....\n\r");

    /* Enable the PWR clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

    /* Allow access to RTC */
    PWR_BackupAccessCmd(ENABLE);

 #ifdef RTC_CLOCK_SOURCE_LSI
    /* Enable the LSI OSC */
    RCC_LSICmd(ENABLE);
 #endif /* RTC_CLOCK_SOURCE_LSI */

    /* Wait for RTC APB registers synchronisation */
    RTC_WaitForSynchro();

    /* Clear the RTC Alarm Flag */
    RTC_ClearFlag(RTC_FLAG_ALRAF);

    /* Clear the EXTI Line 17 Pending bit (Connected internally to RTC Alarm) */
    //EXTI_ClearITPendingBit(EXTI_Line17);

    /* Display the RTC Time and Alarm */
    //RTC_TimeShow();
    //RTC_AlarmShow();
  }
}


// ----------------------------------------------------------------------------
//
// ----------------------------------------------------------------------------
static void RTC_Config(void)
{
  /* Enable the PWR clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  /* Allow access to RTC */
  PWR_BackupAccessCmd(ENABLE);

#if defined (RTC_CLOCK_SOURCE_LSI)  /* LSI used as RTC source clock*/
/* The RTC Clock may varies due to LSI frequency dispersion. */
  /* Enable the LSI OSC */
  RCC_LSICmd(ENABLE);

  /* Wait till LSI is ready */
  while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
  {
  }

  /* Select the RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);

  SynchPrediv = 0x18F;
  AsynchPrediv = 0x63;

#elif defined (RTC_CLOCK_SOURCE_LSE) /* LSE used as RTC source clock */
  /* Enable the LSE OSC */
  RCC_LSEConfig(RCC_LSE_ON);

  /* Wait till LSE is ready */
  while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {
  }

  /* Select the RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

  SynchPrediv = 0xFF;
  AsynchPrediv = 0x7F;

#else
  #error Please select the RTC Clock source inside the main.c file
#endif /* RTC_CLOCK_SOURCE_LSI */

  /* Enable the RTC Clock */
  RCC_RTCCLKCmd(ENABLE);

  /* Wait for RTC APB registers synchronisation */
  RTC_WaitForSynchro();
}


// ----------------------------------------------------------------------------
//
// ----------------------------------------------------------------------------
static void RTC_TimeRegulate ( void )
{
   RTC_TimeTypeDef RTC_TimeStructure;

   RTC_TimeStructure.RTC_Hours   = 14;
   RTC_TimeStructure.RTC_Minutes = 01;
   RTC_TimeStructure.RTC_Seconds = 00;

   RTC_SetTime(RTC_Format_BIN, &RTC_TimeStructure);
   /* Indicator for the RTC configuration */
   RTC_WriteBackupRegister(RTC_BKP_DR0, BKP_VALUE);
}