text: /**
    ******************************************************************************
    * @file    stm32f2xx_ll_exti.c
    * @author  MCD Application Team
    * @brief   EXTI LL module driver.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2017 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
    *
    ******************************************************************************
    */
  
  #if defined(USE_FULL_LL_DRIVER)
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm32f2xx_ll_exti.h"
  #ifdef  USE_FULL_ASSERT
  #include "stm32_assert.h"
  #else
  #define assert_param(expr) ((void)0U)
  #endif
  
  /** @addtogroup STM32F2xx_LL_Driver
    * @{
    */
  
  #if defined (EXTI)
  
  /** @defgroup EXTI_LL EXTI
    * @{
    */
  
  /* Private types -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private constants ---------------------------------------------------------*/
  /* Private macros ------------------------------------------------------------*/
  /** @addtogroup EXTI_LL_Private_Macros
    * @{
    */
  
  #define IS_LL_EXTI_LINE_0_31(__VALUE__)              (((__VALUE__) & ~LL_EXTI_LINE_ALL_0_31) == 0x00000000U)
  
  #define IS_LL_EXTI_MODE(__VALUE__)                   (((__VALUE__) == LL_EXTI_MODE_IT)            \
                                                     || ((__VALUE__) == LL_EXTI_MODE_EVENT)         \
                                                     || ((__VALUE__) == LL_EXTI_MODE_IT_EVENT))
  
  
  #define IS_LL_EXTI_TRIGGER(__VALUE__)                (((__VALUE__) == LL_EXTI_TRIGGER_NONE)       \
                                                     || ((__VALUE__) == LL_EXTI_TRIGGER_RISING)     \
                                                     || ((__VALUE__) == LL_EXTI_TRIGGER_FALLING)    \
                                                     || ((__VALUE__) == LL_EXTI_TRIGGER_RISING_FALLING))
  
  /**
    * @}
    */
  
  /* Private function prototypes -----------------------------------------------*/
  
  /* Exported functions --------------------------------------------------------*/
  /** @addtogroup EXTI_LL_Exported_Functions
    * @{
    */
  
  /** @addtogroup EXTI_LL_EF_Init
    * @{
    */
  
  /**
    * @brief  De-initialize the EXTI registers to their default reset values.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: EXTI registers are de-initialized
    *          - ERROR: not applicable
    */
  uint32_t LL_EXTI_DeInit(void)
  {
    /* Interrupt mask register set to default reset values */
    LL_EXTI_WriteReg(IMR,   0x00000000U);
    /* Event mask register set to default reset values */
    LL_EXTI_WriteReg(EMR,   0x00000000U);
    /* Rising Trigger selection register set to default reset values */
    LL_EXTI_WriteReg(RTSR,  0x00000000U);
    /* Falling Trigger selection register set to default reset values */
    LL_EXTI_WriteReg(FTSR,  0x00000000U);
    /* Software interrupt event register set to default reset values */
    LL_EXTI_WriteReg(SWIER, 0x00000000U);
    /* Pending register set to default reset values */
    LL_EXTI_WriteReg(PR,    0x007FFFFFU);
  
    return SUCCESS;
  }
  
  /**
    * @brief  Initialize the EXTI registers according to the specified parameters in EXTI_InitStruct.
    * @param  EXTI_InitStruct pointer to a @ref LL_EXTI_InitTypeDef structure.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: EXTI registers are initialized
    *          - ERROR: not applicable
    */
  uint32_t LL_EXTI_Init(LL_EXTI_InitTypeDef *EXTI_InitStruct)
  {
    ErrorStatus status = SUCCESS;
    /* Check the parameters */
    assert_param(IS_LL_EXTI_LINE_0_31(EXTI_InitStruct->Line_0_31));
    assert_param(IS_FUNCTIONAL_STATE(EXTI_InitStruct->LineCommand));
    assert_param(IS_LL_EXTI_MODE(EXTI_InitStruct->Mode));
  
    /* ENABLE LineCommand */
    if (EXTI_InitStruct->LineCommand != DISABLE)
    {
      assert_param(IS_LL_EXTI_TRIGGER(EXTI_InitStruct->Trigger));
  
      /* Configure EXTI Lines in range from 0 to 31 */
      if (EXTI_InitStruct->Line_0_31 != LL_EXTI_LINE_NONE)
      {
        switch (EXTI_InitStruct->Mode)
        {
          case LL_EXTI_MODE_IT:
            /* First Disable Event on provided Lines */
            LL_EXTI_DisableEvent_0_31(EXTI_InitStruct->Line_0_31);
            /* Then Enable IT on provided Lines */
            LL_EXTI_EnableIT_0_31(EXTI_InitStruct->Line_0_31);
            break;
          case LL_EXTI_MODE_EVENT:
            /* First Disable IT on provided Lines */
            LL_EXTI_DisableIT_0_31(EXTI_InitStruct->Line_0_31);
            /* Then Enable Event on provided Lines */
            LL_EXTI_EnableEvent_0_31(EXTI_InitStruct->Line_0_31);
            break;
          case LL_EXTI_MODE_IT_EVENT:
            /* Directly Enable IT & Event on provided Lines */
            LL_EXTI_EnableIT_0_31(EXTI_InitStruct->Line_0_31);
            LL_EXTI_EnableEvent_0_31(EXTI_InitStruct->Line_0_31);
            break;
          default:
            status = ERROR;
            break;
        }
        if (EXTI_InitStruct->Trigger != LL_EXTI_TRIGGER_NONE)
        {
          switch (EXTI_InitStruct->Trigger)
          {
            case LL_EXTI_TRIGGER_RISING:
              /* First Disable Falling Trigger on provided Lines */
              LL_EXTI_DisableFallingTrig_0_31(EXTI_InitStruct->Line_0_31);
              /* Then Enable Rising Trigger on provided Lines */
              LL_EXTI_EnableRisingTrig_0_31(EXTI_InitStruct->Line_0_31);
              break;
            case LL_EXTI_TRIGGER_FALLING:
              /* First Disable Rising Trigger on provided Lines */
              LL_EXTI_DisableRisingTrig_0_31(EXTI_InitStruct->Line_0_31);
              /* Then Enable Falling Trigger on provided Lines */
              LL_EXTI_EnableFallingTrig_0_31(EXTI_InitStruct->Line_0_31);
              break;
            case LL_EXTI_TRIGGER_RISING_FALLING:
              LL_EXTI_EnableRisingTrig_0_31(EXTI_InitStruct->Line_0_31);
              LL_EXTI_EnableFallingTrig_0_31(EXTI_InitStruct->Line_0_31);
              break;
            default:
              status = ERROR;
              break;
          }
        }
      }
    }
    /* DISABLE LineCommand */
    else
    {
      /* De-configure EXTI Lines in range from 0 to 31 */
      LL_EXTI_DisableIT_0_31(EXTI_InitStruct->Line_0_31);
      LL_EXTI_DisableEvent_0_31(EXTI_InitStruct->Line_0_31);
    }
    return status;
  }
  
  /**
    * @brief  Set each @ref LL_EXTI_InitTypeDef field to default value.
    * @param  EXTI_InitStruct Pointer to a @ref LL_EXTI_InitTypeDef structure.
    * @retval None
    */
  void LL_EXTI_StructInit(LL_EXTI_InitTypeDef *EXTI_InitStruct)
  {
    EXTI_InitStruct->Line_0_31      = LL_EXTI_LINE_NONE;
    EXTI_InitStruct->LineCommand    = DISABLE;
    EXTI_InitStruct->Mode           = LL_EXTI_MODE_IT;
    EXTI_InitStruct->Trigger        = LL_EXTI_TRIGGER_FALLING;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  #endif /* defined (EXTI) */
  
  /**
    * @}
    */
  
  #endif /* USE_FULL_LL_DRIVER */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  