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/**

  ******************************************************************************

  * @file    stm32l1xx_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) @32MHz (PCLK1) with zero prescaler:

             max timeout before reset: approximately 41.79µs

        (++) Counter max (T[5;0] = 0x3F) @32MHz (PCLK1) with prescaler dividing by 8:

             max timeout before reset: approximately 342.38ms

  ==============================================================================

                     ##### 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 "stm32l1xx_hal.h"

/** @addtogroup STM32L1xx_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****/