

/* Includes ------------------------------------------------------------------*/
#include "stm32l0xx_hal.h"

/** @addtogroup STM32L0xx_HAL_Driver
  * @{
  */

#ifdef HAL_IWDG_MODULE_ENABLED
/** @addtogroup IWDG
  * @brief IWDG HAL module driver.
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/** @defgroup IWDG_Private_Defines IWDG Private Defines
  * @{
  */
/* Status register need 5 RC LSI divided by prescaler clock to be updated. With 
   higher prescaler (256), and according to LSI variation, we need to wait at 
   least 6 cycles so 48 ms. */
#define HAL_IWDG_DEFAULT_TIMEOUT            48U
/**
  * @}
  */

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Exported functions --------------------------------------------------------*/

/** @addtogroup IWDG_Exported_Functions
  * @{
  */

/** @addtogroup IWDG_Exported_Functions_Group1
 *  @brief    Initialization and Start functions.
 *
@verbatim
 ===============================================================================
          ##### Initialization and Start functions #####
 ===============================================================================
 [..]  This section provides functions allowing to:
      (+) Initialize the IWDG according to the specified parameters in the 
          IWDG_InitTypeDef of associated handle.
      (+) Manage Window option.
      (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog 
          is reloaded in order to exit function with correct time base.

@endverbatim
  * @{
  */

/**
  * @brief  Initialize the IWDG according to the specified parameters in the 
  *         IWDG_InitTypeDef and start watchdog. Before exiting function, 
  *         watchdog is refreshed in order to have correct time base.
  * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified IWDG module.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg)
{
  uint32_t tickstart;

  /* Check the IWDG handle allocation */
  if(hiwdg == NULL)
  {
    return HAL_ERROR;
  }

  /* Check the parameters */
  assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance));
  assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler));
  assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload));
  assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window));

  /* Enable IWDG. LSI is turned on automaticaly */
  __HAL_IWDG_START(hiwdg);

  /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing
  0x5555 in KR */
  IWDG_ENABLE_WRITE_ACCESS(hiwdg);

  /* Write to IWDG registers the Prescaler & Reload values to work with */
  hiwdg->Instance->PR = hiwdg->Init.Prescaler;
  hiwdg->Instance->RLR = hiwdg->Init.Reload;

  /* Check pending flag, if previous update not done, return timeout */
  tickstart = HAL_GetTick();

   /* Wait for register to be updated */
  while(hiwdg->Instance->SR != RESET)
  {
    if((HAL_GetTick() - tickstart ) > HAL_IWDG_DEFAULT_TIMEOUT)
    {
      return HAL_TIMEOUT;
    }
  }

  /* If window parameter is different than current value, modify window 
  register */
  if(hiwdg->Instance->WINR != hiwdg->Init.Window)
  {
    /* Write to IWDG WINR the IWDG_Window value to compare with. In any case,
    even if window feature is disabled, Watchdog will be reloaded by writing 
    windows register */
    hiwdg->Instance->WINR = hiwdg->Init.Window;
  }
  else
  {
    /* Reload IWDG counter with value defined in the reload register */
    __HAL_IWDG_RELOAD_COUNTER(hiwdg);
  }

  /* Return function status */
  return HAL_OK;
}

/**
  * @}
  */


/** @addtogroup IWDG_Exported_Functions_Group2
 *  @brief   IO operation functions
 *
@verbatim
 ===============================================================================
                      ##### IO operation functions #####
 ===============================================================================
 [..]  This section provides functions allowing to:
      (+) Refresh the IWDG.

@endverbatim
  * @{
  */


/**
  * @brief  Refresh the IWDG.
  * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified IWDG module.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg)
{
  /* Reload IWDG counter with value defined in the reload register */
  __HAL_IWDG_RELOAD_COUNTER(hiwdg);

  /* Return function status */
  return HAL_OK;
}

/**
  * @}
  */

/**
  * @}
  */

#endif /* HAL_IWDG_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
