/**
  ******************************************************************************
  * @file    WWDG/WWDG_Example/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use the STM32F303xE WWDG HAL API
  *          to update at regular period the WWDG counter and how to generate
  *          a software fault generating an MCU WWDG reset on expiry of a
  *          programmed time period.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F3xx_HAL_Examples
  * @{
  */

/** @addtogroup WWDG_Example
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* WWDG handler declaration */
static WWDG_HandleTypeDef   WwdgHandle;

/* Private function prototypes -----------------------------------------------*/
static uint32_t TimeoutCalculation(uint32_t timevalue);
void            SystemClock_Config(void);
void            SystemClock_Config(void);
static void     Error_Handler(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  uint32_t delay;

  /* STM32F3xx HAL library initialization:
       - Configure the Flash prefetch
       - Configure the Systick to generate an interrupt each 1 msec
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  HAL_Init();
  
  /* Configure the system clock to 64 MHz */
  SystemClock_Config();

  /* Configure LED2 */
  BSP_LED_Init(LED2);

  /*##-1- Check if the system has resumed from WWDG reset ####################*/
  if (__HAL_RCC_GET_FLAG(RCC_FLAG_WWDGRST) != RESET)
  {
    /* WWDGRST flag set: Turn LED2 on */
    BSP_LED_On(LED2);

    /* Insert 4s delay */
    HAL_Delay(4000);

    /* Prior to clear WWDGRST flag: Turn LED2 off */
    BSP_LED_Off(LED2);
  }

  /* Clear reset flags in any case */
  __HAL_RCC_CLEAR_RESET_FLAGS();

  /* Configure User push-button */
  BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);

  /*##-2- Init & Start WWDG peripheral ######################################*/
  /* WWDG clock counter = (PCLK1 (32MHz)/4096)/8) = 976 Hz (~1024 us) 
     WWDG Window value = 80 means that the WWDG counter should be refreshed only 
     when the counter is below 80 (and greater than 64/0x40) otherwise a reset will 
     be generated. 
     WWDG Counter value = 127, WWDG timeout = ~1024 us * 64 = 65.57 ms
     In this case the refresh window is comprised between : ~1024 * (127-80) = 48.1ms and ~1024 * 64 = 65.53ms
   */
  WwdgHandle.Instance = WWDG;
  WwdgHandle.Init.Prescaler = WWDG_PRESCALER_8;
  WwdgHandle.Init.Window    = 0x50;
  WwdgHandle.Init.Counter   = 0x7F;
  WwdgHandle.Init.EWIMode   = WWDG_EWI_DISABLE;

  if (HAL_WWDG_Init(&WwdgHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* calculate delay to enter window. Add 1ms to secure round number to upper number  */
  delay = TimeoutCalculation((WwdgHandle.Init.Counter-WwdgHandle.Init.Window) + 1) + 1;

  /* Infinite loop */
  while (1)
  {
    /* Toggle LED2 */
    BSP_LED_Toggle(LED2);

    /* Insert calculated delay */
    HAL_Delay(delay);

    if (HAL_WWDG_Refresh(&WwdgHandle) != HAL_OK)
    {
      Error_Handler();
    }
  }
}


/**
  * @brief  Timeout calculation function.
  *         This function calculates any timeout related to 
  *         WWDG with given prescaler and system clock.
  * @param  timevalue: period in term of WWDG counter cycle.
  * @retval None
  */
static uint32_t TimeoutCalculation(uint32_t timevalue)
{
  uint32_t timeoutvalue = 0;
  uint32_t pclk1 = 0;
  uint32_t wdgtb = 0;

  /* considering APB divider is still 1, use HCLK value */
  pclk1 = HAL_RCC_GetPCLK1Freq();

  /* get prescaler */
  wdgtb = (1 << ((WwdgHandle.Init.Prescaler) >> 7)); /* 2^WDGTB[1:0] */

  /* calculate timeout */
  timeoutvalue = ((4096 * wdgtb * timevalue) / (pclk1 / 1000));

  return timeoutvalue;
}


/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSI)
  *            SYSCLK(Hz)                     = 64000000
  *            HCLK(Hz)                       = 64000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 8000000
  *            PREDIV                         = RCC_PREDIV_DIV2 (2)
  *            PLLMUL                         = RCC_PLL_MUL16 (16)
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* HSI Oscillator already ON after system reset, activate PLL with HSI as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_NONE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 
     clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;  
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}
/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED2 off */
  BSP_LED_Off(LED2);

  while(1)
  {
  }
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif

/**
  * @}
  */

/**
  * @}
  */