/**
  ******************************************************************************
  * @file    stm32l0xx_hal_wwdg.c
  * @author  MCD Application Team
  * @brief   WWDG HAL module driver.
  *          This file provides firmware functions to manage the following
  *          functionalities of the Window Watchdog (WWDG) peripheral:
  *           + Initialization and Configuration functions
  *           + IO operation functions
  @verbatim
  ==============================================================================
                      ##### WWDG Specific features #####
  ==============================================================================
  [..]
    Once enabled the WWDG generates a system reset on expiry of a programmed
    time period, unless the program refreshes the counter (T[6;0] downcounter)
    before reaching 0x3F value (i.e. a reset is generated when the counter
    value rolls down from 0x40 to 0x3F).

    (+) An MCU reset is also generated if the counter value is refreshed
        before the counter has reached the refresh window value. This
        implies that the counter must be refreshed in a limited window.
    (+) Once enabled the WWDG cannot be disabled except by a system reset.
    (+) WWDGRST flag in RCC CSR register can be used to inform when a WWDG
        reset occurs.
    (+) The WWDG counter input clock is derived from the APB clock divided
        by a programmable prescaler.
    (+) WWDG clock (Hz) = PCLK1 / (4096 * Prescaler)
    (+) WWDG timeout (mS) = 1000 * (T[5;0] + 1) / WWDG clock (Hz)
        where T[5;0] are the lowest 6 bits of Counter.
    (+) WWDG Counter refresh is allowed between the following limits :
        (++) min time (mS) = 1000 * (Counter - Window) / WWDG clock
        (++) max time (mS) = 1000 * (Counter - 0x40) / WWDG clock
    (+) Typical values:
        (++) Counter min (T[5;0] = 0x00) @56 MHz(PCLK1) with zero prescaler:
             max timeout before reset: ~73.14 µs
        (++) Counter max (T[5;0] = 0x3F) @56 MHz(PCLK1) with prescaler dividing by 128:
             max timeout before reset: ~599.18 ms

  ==============================================================================
                     ##### How to use this driver #####
  ==============================================================================
  [..]
    *** Common driver usage ***
    ===========================
    (+) Enable WWDG APB1 clock using __HAL_RCC_WWDG_CLK_ENABLE().
    (+) Set the WWDG prescaler, refresh window and counter value
        using HAL_WWDG_Init() function.
    (+) Start the WWDG using HAL_WWDG_Start() function.
        When the WWDG is enabled the counter value should be configured to
        a value greater than 0x40 to prevent generating an immediate reset.
    (+) Optionally you can enable the Early Wakeup Interrupt (EWI) which is
        generated when the counter reaches 0x40, and then start the WWDG using
        HAL_WWDG_Start_IT(). At EWI HAL_WWDG_WakeupCallback is executed and user can
        add his own code by customization of callback HAL_WWDG_WakeupCallback.
        Once enabled, EWI interrupt cannot be disabled except by a system reset.
    (+) Then the application program must refresh the WWDG counter at regular
        intervals during normal operation to prevent an MCU reset, using
        HAL_WWDG_Refresh() function. This operation must occur only when
        the counter is lower than the refresh window value already programmed.

  [..]
    *** Callback registration ***
    =============================
    The compilation define  USE_HAL_WWDG_REGISTER_CALLBACKS when set to 1 allows
    the user to configure dynamically the driver callbacks. Use Functions
    @ref HAL_WWDG_RegisterCallback() to register a user callback.

    (+) Function @ref HAL_WWDG_RegisterCallback() allows to register following
        callbacks:
        (++) EwiCallback : callback for Early WakeUp Interrupt.
        (++) MspInitCallback : WWDG MspInit.
    This function takes as parameters the HAL peripheral handle, the Callback ID
    and a pointer to the user callback function.

    (+) Use function @ref HAL_WWDG_UnRegisterCallback() to reset a callback to
    the default weak (surcharged) function. @ref HAL_WWDG_UnRegisterCallback()
    takes as parameters the HAL peripheral handle and the Callback ID.
    This function allows to reset following callbacks:
        (++) EwiCallback : callback for  Early WakeUp Interrupt.
        (++) MspInitCallback : WWDG MspInit.

    When calling @ref HAL_WWDG_Init function, callbacks are reset to the
    corresponding legacy weak (surcharged) functions: 
    @ref HAL_WWDG_EarlyWakeupCallback() and HAL_WWDG_MspInit() only if they have
    not been registered before.

    When compilation define USE_HAL_WWDG_REGISTER_CALLBACKS is set to 0 or
    not defined, the callback registering feature is not available 
    and weak (surcharged) callbacks are used.

    *** WWDG HAL driver macros list ***
    ===================================
    [..]
      Below the list of most used macros in WWDG HAL driver.
      (+) __HAL_WWDG_ENABLE: Enable the WWDG peripheral
      (+) __HAL_WWDG_GET_FLAG: Get the selected WWDG's flag status
      (+) __HAL_WWDG_CLEAR_FLAG: Clear the WWDG's pending flags
      (+) __HAL_WWDG_ENABLE_IT: Enable the WWDG early wakeup interrupt

  @endverbatim
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32L0xx_HAL_Driver
  * @{
  */

#ifdef HAL_WWDG_MODULE_ENABLED
/** @defgroup WWDG WWDG
  * @brief WWDG HAL module driver.
  * @{
  */

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

/** @defgroup WWDG_Exported_Functions WWDG Exported Functions
  * @{
  */

/** @defgroup WWDG_Exported_Functions_Group1 Initialization and Configuration functions
 *  @brief    Initialization and Configuration functions.
 *
@verbatim
  ==============================================================================
          ##### Initialization and Configuration functions #####
  ==============================================================================
  [..]
    This section provides functions allowing to:
      (+) Initialize and start the WWDG according to the specified parameters
          in the WWDG_InitTypeDef of associated handle.
      (+) Initialize the WWDG MSP.

@endverbatim
  * @{
  */

/**
  * @brief  Initialize the WWDG according to the specified.
  *         parameters in the WWDG_InitTypeDef of  associated handle.
  * @param  hwwdg  pointer to a WWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified WWDG module.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_WWDG_Init(WWDG_HandleTypeDef *hwwdg)
{
  /* Check the WWDG handle allocation */
  if (hwwdg == NULL)
  {
    return HAL_ERROR;
  }

  /* Check the parameters */
  assert_param(IS_WWDG_ALL_INSTANCE(hwwdg->Instance));
  assert_param(IS_WWDG_PRESCALER(hwwdg->Init.Prescaler));
  assert_param(IS_WWDG_WINDOW(hwwdg->Init.Window));
  assert_param(IS_WWDG_COUNTER(hwwdg->Init.Counter));
  assert_param(IS_WWDG_EWI_MODE(hwwdg->Init.EWIMode));

#if (USE_HAL_WWDG_REGISTER_CALLBACKS == 1)
  /* Reset Callback pointers */
  if(hwwdg->EwiCallback == NULL)
  {
    hwwdg->EwiCallback = HAL_WWDG_EarlyWakeupCallback;
  }

  if(hwwdg->MspInitCallback == NULL)
  {
    hwwdg->MspInitCallback = HAL_WWDG_MspInit;
  }

  /* Init the low level hardware */
  hwwdg->MspInitCallback(hwwdg);
#else
  /* Init the low level hardware */
  HAL_WWDG_MspInit(hwwdg);
#endif

  /* Set WWDG Counter */
  WRITE_REG(hwwdg->Instance->CR, (WWDG_CR_WDGA | hwwdg->Init.Counter));

  /* Set WWDG Prescaler and Window */
  WRITE_REG(hwwdg->Instance->CFR, (hwwdg->Init.EWIMode | hwwdg->Init.Prescaler | hwwdg->Init.Window));

  /* Return function status */
  return HAL_OK;
}


/**
  * @brief  Initialize the WWDG MSP.
  * @param  hwwdg  pointer to a WWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified WWDG module.
  * @note   When rewriting this function in user file, mechanism may be added
  *         to avoid multiple initialize when HAL_WWDG_Init function is called
  *         again to change parameters.
  * @retval None
  */
__weak void HAL_WWDG_MspInit(WWDG_HandleTypeDef *hwwdg)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hwwdg);

  /* NOTE: This function should not be modified, when the callback is needed,
           the HAL_WWDG_MspInit could be implemented in the user file
   */
}


#if (USE_HAL_WWDG_REGISTER_CALLBACKS == 1)
/**
  * @brief  Register a User WWDG Callback
  *         To be used instead of the weak (surcharged) predefined callback
  * @param  hwwdg WWDG handle
  * @param  CallbackID ID of the callback to be registered
  *         This parameter can be one of the following values:
  *           @arg @ref HAL_WWDG_EWI_CB_ID Early WakeUp Interrupt Callback ID
  *           @arg @ref HAL_WWDG_MSPINIT_CB_ID MspInit callback ID
  * @param  pCallback pointer to the Callback function
  * @retval status
  */
HAL_StatusTypeDef HAL_WWDG_RegisterCallback(WWDG_HandleTypeDef *hwwdg, HAL_WWDG_CallbackIDTypeDef CallbackID, pWWDG_CallbackTypeDef pCallback)
{
  HAL_StatusTypeDef status = HAL_OK;

  if(pCallback == NULL)
  {
    status = HAL_ERROR;
  }
  else
  {
    switch(CallbackID)
    {
      case HAL_WWDG_EWI_CB_ID:
        hwwdg->EwiCallback = pCallback;
        break;

      case HAL_WWDG_MSPINIT_CB_ID:
        hwwdg->MspInitCallback = pCallback;
        break;

      default:
        status = HAL_ERROR;
        break;
    }
  }

  return status;
}


/**
  * @brief  Unregister a WWDG Callback
  *         WWDG Callback is redirected to the weak (surcharged) predefined callback 
  * @param  hwwdg WWDG handle
  * @param  CallbackID ID of the callback to be registered
  *         This parameter can be one of the following values:
  *           @arg @ref HAL_WWDG_EWI_CB_ID Early WakeUp Interrupt Callback ID
  *           @arg @ref HAL_WWDG_MSPINIT_CB_ID MspInit callback ID
  * @retval status
  */
HAL_StatusTypeDef HAL_WWDG_UnRegisterCallback(WWDG_HandleTypeDef *hwwdg, HAL_WWDG_CallbackIDTypeDef CallbackID)
{
  HAL_StatusTypeDef status = HAL_OK;

  switch(CallbackID)
  {
    case HAL_WWDG_EWI_CB_ID:
      hwwdg->EwiCallback = HAL_WWDG_EarlyWakeupCallback;
      break;

    case HAL_WWDG_MSPINIT_CB_ID:
      hwwdg->MspInitCallback = HAL_WWDG_MspInit;
      break;

    default:
      status = HAL_ERROR;
      break;
  }

  return status;
}
#endif

/**
  * @}
  */

/** @defgroup WWDG_Exported_Functions_Group2 IO operation functions
 *  @brief    IO operation functions
 *
@verbatim
  ==============================================================================
                      ##### IO operation functions #####
  ==============================================================================
  [..]
    This section provides functions allowing to:
    (+) Refresh the WWDG.
    (+) Handle WWDG interrupt request and associated function callback.

@endverbatim
  * @{
  */

/**
  * @brief  Refresh the WWDG.
  * @param  hwwdg  pointer to a WWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified WWDG module.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_WWDG_Refresh(WWDG_HandleTypeDef *hwwdg)
{
  /* Write to WWDG CR the WWDG Counter value to refresh with */
  WRITE_REG(hwwdg->Instance->CR, (hwwdg->Init.Counter));

  /* Return function status */
  return HAL_OK;
}

/**
  * @brief  Handle WWDG interrupt request.
  * @note   The Early Wakeup Interrupt (EWI) can be used if specific safety operations
  *         or data logging must be performed before the actual reset is generated.
  *         The EWI interrupt is enabled by calling HAL_WWDG_Init function with
  *         EWIMode set to WWDG_EWI_ENABLE.
  *         When the downcounter reaches the value 0x40, and EWI interrupt is
  *         generated and the corresponding Interrupt Service Routine (ISR) can
  *         be used to trigger specific actions (such as communications or data
  *         logging), before resetting the device.
  * @param  hwwdg  pointer to a WWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified WWDG module.
  * @retval None
  */
void HAL_WWDG_IRQHandler(WWDG_HandleTypeDef *hwwdg)
{
  /* Check if Early Wakeup Interrupt is enable */
  if (__HAL_WWDG_GET_IT_SOURCE(hwwdg, WWDG_IT_EWI) != RESET)
  {
    /* Check if WWDG Early Wakeup Interrupt occurred */
    if (__HAL_WWDG_GET_FLAG(hwwdg, WWDG_FLAG_EWIF) != RESET)
    {
      /* Clear the WWDG Early Wakeup flag */
      __HAL_WWDG_CLEAR_FLAG(hwwdg, WWDG_FLAG_EWIF);

#if (USE_HAL_WWDG_REGISTER_CALLBACKS == 1)
      /* Early Wakeup registered callback */
      hwwdg->EwiCallback(hwwdg);
#else
      /* Early Wakeup callback */
      HAL_WWDG_EarlyWakeupCallback(hwwdg);
#endif
    }
  }
}


/**
  * @brief  WWDG Early Wakeup callback.
  * @param  hwwdg  pointer to a WWDG_HandleTypeDef structure that contains
  *                the configuration information for the specified WWDG module.
  * @retval None
  */
__weak void HAL_WWDG_EarlyWakeupCallback(WWDG_HandleTypeDef *hwwdg)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hwwdg);

  /* NOTE: This function should not be modified, when the callback is needed,
           the HAL_WWDG_EarlyWakeupCallback could be implemented in the user file
   */
}

/**
  * @}
  */

/**
  * @}
  */

#endif /* HAL_WWDG_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

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