path: root/tool/mbed/mbed-sdk/libraries/mbed/targets/cmsis/TARGET_STM/TARGET_STM32L1/stm32l1xx_hal_comp.c

/**
  ******************************************************************************
  * @file    stm32l1xx_hal_comp.c
  * @author  MCD Application Team
  * @version V1.0.0
  * @date    5-September-2014
  * @brief   COMP HAL module driver.
  *    
  *          This file provides firmware functions to manage the following 
  *          functionalities of the COMP peripheral:
  *           + Initialization and de-initialization functions
  *           + I/O operation functions
  *           + Peripheral Control functions 
  *           + Peripheral State functions
  *         
  @verbatim
================================================================================
          ##### COMP Peripheral features #####
================================================================================
           
  [..]       
      The STM32L1xx device family integrates 2 analog comparators COMP1 and 
      COMP2:
      (#) The non inverting input and inverting input can be set to GPIO pins.
          Refer to "table1. COMP Inputs" below.
          HAL COMP driver configures the Routing Interface (RI) to connect the
          selected I/O pins to comparator input.
          Caution: Comparator COMP1 and ADC cannot be used at the same time as 
          ADC since they share the ADC switch matrix: COMP1 non-inverting 
          input is routed through ADC switch matrix. Except if ADC is intented 
          to measure voltage on COMP1 non-inverting input: it can be performed 
          on ADC channel VCOMP.

      (#) The COMP output is available using HAL_COMP_GetOutputLevel().

      (#) The COMP output can be redirected to embedded timers (TIM2, TIM3, 
          TIM4, TIM10).
          COMP output cannot be redirected to any I/O pin.
          Refer to "table 2. COMP Outputs redirection to embedded timers" below.

      (#) The comparators COMP1 and COMP2 can be combined in window mode. 
          In this mode, COMP2 non inverting input is used as common 
          non-inverting input.
  
      (#) The 2 comparators have interrupt capability with wake-up
          from Sleep and Stop modes (through the EXTI controller):
          (++) COMP1 is internally connected to EXTI Line 21
          (++) COMP2 is internally connected to EXTI Line 22

          From the corresponding IRQ handler, the right interrupt source can be
          retrieved with macro __HAL_COMP_EXTI_GET_FLAG(). Possible values are: 
          (++) COMP_EXTI_LINE_COMP1_EVENT
          (++) COMP_EXTI_LINE_COMP2_EVENT
  
      (#) The comparators also offer the possibility to ouput the voltage 
          reference (VrefInt), used on inverting inputs, on I/O pin through 
          a buffer. To use it, refer to macro "__HAL_VREFINT_OUT_ENABLE()".

            
[..] Table 1. COMP Inputs for the STM32L1xx devices
 +----------------------------------------------------------------------+
 |                 |                                |  COMP1  |  COMP2  |
 |-----------------|--------------------------------|---------|---------|
 |                 | 1/4 VREFINT                    |   --    |   OK    |
 |                 | 1/2 VREFINT                    |   --    |   OK    |
 |                 | 3/4 VREFINT                    |   --    |   OK    |
 | Inverting       | VREFINT                        |   OK    |   OK    |
 | input           | DAC Ch1 OUT (PA4)              |   --    |   OK    |
 |                 | DAC Ch2 OUT (PA5)              |   --    |   OK    |
 |                 | IO: PB3                        |   --    |   OK    |
 |-----------------|--------------------------------|---------|---------|
 |                 | IO:                            |         |         |
 |                 |   PB4, 5, 6*, 7*               |   ---   |   OK    |
 | Non-inverting   |   PA0*, 1*, 2*, 3*, 4, 5, 6, 7 |   OK    |   ---   |
 | input           |   PB0, 1, 12, 13, 14, 15       |   OK    |   ---   |
 |                 |   PC0, 1, 2, 3, 4, 5           |   OK    |   ---   |
 |                 |   PE7, 8, 9, 10                |   OK    |   ---   |
 |                 |   PF6, 7, 8, 9, 10             |   OK    |   ---   |
 |                 | OPAMP1 output                  |   OK    |   ---   |
 |                 | OPAMP2 output                  |   OK    |   ---   |
 |                 | OPAMP3 output**                |   OK    |   ---   |
 +----------------------------------------------------------------------+
 *: Available on devices category Cat.3, Cat.4, Cat.5 only. 
 **: Available on devices category Cat.4 only. 

 [..] Table 2. COMP Outputs redirection to embedded timers
 +-----------------------------------+     
 |      COMP1      |      COMP2      |
 |-----------------|-----------------|
 |                 |  TIM2 IC4       |
 |                 |  TIM2 OCREF CLR |
 | (no redirection |  TIM3 IC4       |
 |   to timers)    |  TIM3 OCREF CLR |
 |                 |  TIM4 IC4       |
 |                 |  TIM4 OCREF CLR |
 |                 |  TIM10 IC1      |
 +-----------------------------------+


            ##### How to use this driver #####
================================================================================
  [..]
      This driver provides functions to configure and program the Comparators of all STM32L1xx devices.

      To use the comparator, perform the following steps:
  
      (#)  Initialize the COMP low level resources by implementing the HAL_COMP_MspInit().
      (++) Configure the comparator input I/O pin using HAL_GPIO_Init():
           - For all inputs: I/O pin in analog mode (Schmitt trigger disabled)
           - Possible alternate configuration, for non-inverting inputs of comparator 2: I/O pin in floating mode (Schmitt trigger enabled).
           It is recommended to use analog configuration to avoid any overconsumption around VDD/2.
      (++) Enable COMP Peripheral clock using macro __COMP_CLK_ENABLE()
      (++) If required enable the COMP interrupt (EXTI line Interrupt): enable
           the comparator interrupt vector using HAL_NVIC_EnableIRQ(COMP_IRQn)
           and HAL_NVIC_SetPriority(COMP_IRQn, xxx, xxx) functions.
  
      (#) Configure the comparator using HAL_COMP_Init() function:
      (++) Select the inverting input (COMP2 only)
      (++) Select the non-inverting input
      (++) Select the output redirection to timers (COMP2 only)
      (++) Select the speed mode (COMP2 only)
      (++) Select the window mode (related to COMP1 and COMP2, but selected 
           by COMP2 only)
      (++) Select the pull-up/down resistors on non-inverting input (COMP1 only)

      (#) Enable the comparator using HAL_COMP_Start() or HAL_COMP_Start_IT() 
          function
    
      (#) If needed, use HAL_COMP_GetOutputLevel() or HAL_COMP_TriggerCallback()
          functions to manage comparator actions (output level or events)

      (#) Disable the comparator using HAL_COMP_Stop() or HAL_COMP_Stop_IT() 
          function

      (#) De-initialize the comparator using HAL_COMP_DeInit() function


  @endverbatim
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************  
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_hal.h"

/** @addtogroup STM32L1xx_HAL_Driver
  * @{
  */

/** @defgroup COMP COMP
  * @brief COMP HAL module driver
  * @{
  */

#ifdef HAL_COMP_MODULE_ENABLED

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/

/** @defgroup COMP_Private_Constants COMP Private Constants
  * @{
  */
  /* Delay for COMP startup time.                                             */
  /* Maximum delay is 10us for comparator 1 and 25us for comparator 2 in slow */
  /* mode (refer to device datasheet, parameter tSTART).                      */
  /* Delay in CPU cycles, fixed to worst case: maximum CPU frequency 32MHz to */
  /* have the minimum number of CPU cycles to fulfill this delay.             */
  /*  - Comparator 1: delay minimum of 320 CPU cyles. Wait loop takes 3 CPU   */
  /*                 cycles per iteration, therefore total wait iterations    */
  /*                 number must be initialized at 106 iterations.            */
  /*  - Comparator 2: delay minimum of 800 CPU cyles. Wait loop takes 3 CPU   */
  /*                 cycles per iteration, therefore total wait iterations    */
  /*                 number must be initialized at 266 iterations.            */
#define COMP1_START_DELAY_CPU_CYCLES       ((uint32_t)106)
#define COMP2_START_DELAY_CPU_CYCLES       ((uint32_t)266)

  /* Comparator status "locked": to update COMP handle state (software lock   */
  /* only on COMP of STM32L1xx devices) by bitfield:                          */
  /* states HAL_COMP_STATE_READY_LOCKED, HAL_COMP_STATE_BUSY_LOCKED.          */
#define COMP_STATE_BIT_LOCK     ((uint32_t) 0x00000010)  

/**
  * @}
  */


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

/** @defgroup COMP_Exported_Functions COMP Exported Functions
  * @{
  */

/** @defgroup COMP_Exported_Functions_Group1 Initialization and de-initialization functions 
 *  @brief    Initialization and Configuration functions 
 *
@verbatim    
 ===============================================================================
              ##### Initialization and de-initialization functions #####
 ===============================================================================
    [..]  This section provides functions to initialize and de-initialize comparators 

@endverbatim
  * @{
  */

/**
  * @brief  Initializes the COMP according to the specified
  *         parameters in the COMP_InitTypeDef and create the associated handle.
  * @note   If the selected comparator is locked, initialization can't be performed.
  *         To unlock the configuration, perform a system reset.
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_Init(COMP_HandleTypeDef *hcomp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Check the COMP handle allocation and lock status */
  if((hcomp == HAL_NULL) || ((hcomp->State & COMP_STATE_BIT_LOCK) != RESET))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

    if (hcomp->Instance == COMP1)
    {
      assert_param(IS_COMP_NONINVERTINGINPUTPULL(hcomp->Init.NonInvertingInputPull));
    }
    else /* if (hcomp->Instance == COMP2) */
    {
      assert_param(IS_COMP_INVERTINGINPUT(hcomp->Init.InvertingInput));
      assert_param(IS_COMP_OUTPUT(hcomp->Init.Output));
      assert_param(IS_COMP_MODE(hcomp->Init.Mode));
      assert_param(IS_COMP_WINDOWMODE(hcomp->Init.WindowMode));
    }
  
    /* In window mode, non-inverting inputs of the 2 comparators are          */
    /* connected together and are using inputs of COMP2 only. If COMP1 is     */
    /* selected, this parameter is discarded.                                 */
    if ((hcomp->Init.WindowMode == COMP_WINDOWMODE_DISABLED) ||
        (hcomp->Instance == COMP2)                             )
    {
      assert_param(IS_COMP_NONINVERTINGINPUT(hcomp->Init.NonInvertingInput));
    }
    
      
    /* Enable SYSCFG clock and the low level hardware to access comparators */
    if(hcomp->State == HAL_COMP_STATE_RESET)
    {
      /* Enable SYSCFG clock to control the routing Interface (RI) */
      __SYSCFG_CLK_ENABLE();
      
      /* Init the low level hardware */
      HAL_COMP_MspInit(hcomp);
    }
  
    /* Configuration of comparator:                                           */
    /*  - Output selection                                                    */
    /*  - Inverting input selection                                           */
    /*  - Window mode                                                         */
    /*  - Mode fast/slow speed                                                */
    /*  - Inverting input pull-up/down resistors                              */
    
    /* Configuration depending on comparator instance */
    if (hcomp->Instance == COMP1)
    {
      MODIFY_REG(COMP->CSR, COMP_CSR_400KPD | COMP_CSR_10KPD | COMP_CSR_400KPU | COMP_CSR_10KPU,
                            hcomp->Init.NonInvertingInputPull                                   );
    }
    else /* if (hcomp->Instance == COMP2) */
    {
      /* Note: If comparator 2 is not enabled, inverting input (parameter     */
      /*       "hcomp->Init.InvertingInput") is configured into function      */
      /*       "HAL_COMP_Start()" since inverting  input selection also       */
      /*       enables the comparator 2.                                      */
      /*       If comparator 2 is already enabled, inverting input is         */
      /*       reconfigured on the fly.                                       */
      if (__COMP_IS_ENABLED(hcomp) == RESET)
      {
        MODIFY_REG(COMP->CSR, COMP_CSR_OUTSEL  |
                              COMP_CSR_WNDWE   |
                              COMP_CSR_SPEED          ,
                              hcomp->Init.Output     |
                              hcomp->Init.WindowMode |
                              hcomp->Init.Mode        );
      }
      else
      {
        MODIFY_REG(COMP->CSR, COMP_CSR_OUTSEL  |
                              COMP_CSR_INSEL   |
                              COMP_CSR_WNDWE   |
                              COMP_CSR_SPEED              ,
                              hcomp->Init.Output         |
                              hcomp->Init.InvertingInput |
                              hcomp->Init.WindowMode     |
                              hcomp->Init.Mode            );
      }
    }
    
    /* Configure Routing Interface (RI) switches for comparator non-inverting */
    /* input.                                                                 */
    /* Except in 2 cases:                                                     */
    /* - if non-inverting input has no selection: it can be the case for      */
    /*   COMP1 in window mode.                                                */
    /* - particular case for PC3: if switch COMP1_SW1 is closed               */
    /*   (by macro "__HAL_OPAMP_OPAMP3OUT_CONNECT_ADC_COMP1()" or             */
    /*   "__HAL_RI_SWITCH_COMP1_SW1_CLOSE()"), connection between pin PC3     */
    /*    (or OPAMP3, if available) and COMP1 is done directly, without going */
    /*    through ADC switch matrix.                                          */
    if (__COMP_ROUTING_INTERFACE_TOBECONFIGURED(hcomp))
    {
      if (hcomp->Instance == COMP1)
      {
        /* Enable the switch control mode */
        __HAL_RI_SWITCHCONTROLMODE_ENABLE();

        /* Close the analog switch of ADC switch matrix to COMP1 (ADC         */
        /* channel 26: Vcomp)                                                 */
        __HAL_RI_IOSWITCH_CLOSE(RI_IOSWITCH_VCOMP);
      }

      /* Close the I/O analog switch corresponding to comparator              */
      /* non-inverting input selected.                                        */
      __HAL_RI_IOSWITCH_CLOSE(hcomp->Init.NonInvertingInput);
    }

    
    /* Initialize the COMP state*/
    if(hcomp->State == HAL_COMP_STATE_RESET)
    {
      hcomp->State = HAL_COMP_STATE_READY;
    }
  }
  
  return status;
}


/**
  * @brief  DeInitializes the COMP peripheral 
  * @note   Deinitialization can't be performed if the COMP configuration is locked.
  *         To unlock the configuration, perform a system reset.
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_DeInit(COMP_HandleTypeDef *hcomp)
{
  HAL_StatusTypeDef status = HAL_OK;

  /* Check the COMP handle allocation and lock status */
  if((hcomp == HAL_NULL) || ((hcomp->State & COMP_STATE_BIT_LOCK) != RESET))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));
    
    /* Reset configuration depending on comparator instance */
    if (hcomp->Instance == COMP1)
    {
      CLEAR_BIT(COMP->CSR , COMP_CSR_400KPD | COMP_CSR_10KPD | COMP_CSR_400KPU | COMP_CSR_10KPU);
    }
    else /* if (hcomp->Instance == COMP2) */
    {
      CLEAR_BIT(COMP->CSR , COMP_CSR_OUTSEL |
                            COMP_CSR_WNDWE  |
                            COMP_CSR_INSEL  |
                            COMP_CSR_SPEED   );
    }
    
    
    /* Restore default state of Routing Interface (RI) switches for           */
    /* comparator non-inverting input.                                        */
    if (hcomp->Init.NonInvertingInput != COMP_NONINVERTINGINPUT_NONE)
    {
      /* Open the I/O analog switch corresponding to comparator               */
      /* non-inverting input selected.                                        */
      __HAL_RI_IOSWITCH_OPEN(hcomp->Init.NonInvertingInput);
    }
    if (hcomp->Instance == COMP1)
    {
      /* Open the analog switch of ADC switch matrix to COMP1 (ADC            */
      /* channel 26: Vcomp)                                                   */
      __HAL_RI_IOSWITCH_OPEN(RI_IOSWITCH_VCOMP);
      
      /* Disable the switch control mode */
      __HAL_RI_SWITCHCONTROLMODE_DISABLE();
    }
  
    
    /* DeInit the low level hardware: SYSCFG, GPIO, CLOCK and NVIC */
    HAL_COMP_MspDeInit(hcomp);

    hcomp->State = HAL_COMP_STATE_RESET;
    
    /* Process unlocked */
    __HAL_UNLOCK(hcomp);
  }
  
  return status;
}

/**
  * @brief  Initializes the COMP MSP.
  * @param  hcomp: COMP handle
  * @retval None
  */
__weak void HAL_COMP_MspInit(COMP_HandleTypeDef *hcomp)
{
  /* NOTE : This function Should not be modified, when the callback is needed,
            the HAL_COMP_MspInit could be implenetd in the user file
   */
}

/**
  * @brief  DeInitializes COMP MSP.
  * @param  hcomp: COMP handle
  * @retval None
  */
__weak void HAL_COMP_MspDeInit(COMP_HandleTypeDef *hcomp)
{
  /* NOTE : This function Should not be modified, when the callback is needed,
            the HAL_COMP_MspDeInit could be implenetd in the user file
   */
}

/**
  * @}
  */

/** @defgroup COMP_Exported_Functions_Group2 I/O operation functions 
 *  @brief   I/O operation functions
 *
@verbatim   
 ===============================================================================
                      ##### IO operation functions #####
 ===============================================================================  
    [..]
    This subsection provides a set of functions allowing to manage the COMP 
    start and stop actions with or without interruption on ExtI line.

@endverbatim
  * @{
  */

/**
  * @brief  Start the comparator 
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_Start(COMP_HandleTypeDef *hcomp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  uint32_t wait_loop_cycles = 0;
  __IO uint32_t wait_loop_index = 0;
  
  /* Check the COMP handle allocation and lock status */
  if((hcomp == HAL_NULL) || ((hcomp->State & COMP_STATE_BIT_LOCK) != RESET))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

    if(hcomp->State == HAL_COMP_STATE_READY)
    {
      
      /* Note: For comparator 2, inverting input (parameter                   */
      /*       "hcomp->Init.InvertingInput") is configured into this          */
      /*       function instead of function "HAL_COMP_Init()" since           */
      /*       inverting input selection also enables the comparator 2.       */
      __HAL_COMP_ENABLE(hcomp);

      /* Set delay for COMP startup time */
      if (hcomp->Instance == COMP1)
      {
        wait_loop_cycles = COMP1_START_DELAY_CPU_CYCLES;
      }
      else /* if (hcomp->Instance == COMP2) */
      {
        wait_loop_cycles = COMP2_START_DELAY_CPU_CYCLES;
      }

      /* Delay for COMP startup time.                                         */
      /* Delay fixed to worst case: maximum CPU frequency                     */
      while(wait_loop_index < wait_loop_cycles)
      {
        wait_loop_index++;
      }

      /* Update COMP state */
      hcomp->State = HAL_COMP_STATE_BUSY;
      
    }
    else
    {
      status = HAL_ERROR;
    }
  }

  return status;
}

/**
  * @brief  Stop the comparator 
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_Stop(COMP_HandleTypeDef *hcomp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Check the COMP handle allocation and lock status */
  if((hcomp == HAL_NULL) || ((hcomp->State & COMP_STATE_BIT_LOCK) != RESET))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

    if(hcomp->State == HAL_COMP_STATE_BUSY)
    {
      /* Disable the selected comparator */
      __HAL_COMP_DISABLE(hcomp);
      
      /* Update COMP state */
      hcomp->State = HAL_COMP_STATE_READY;
    }
    else
    {
      status = HAL_ERROR;
    }
  }
  
  return status;
}

/**
  * @brief  Enables the interrupt and starts the comparator
  * @param  hcomp: COMP handle
  * @retval HAL status.
  */
HAL_StatusTypeDef HAL_COMP_Start_IT(COMP_HandleTypeDef *hcomp)
{ 
  HAL_StatusTypeDef status = HAL_OK; 
  uint32_t extiline = 0;
  
  status = HAL_COMP_Start(hcomp);
  if(status == HAL_OK)
  {
    /* Check the parameter */
    assert_param(IS_COMP_TRIGGERMODE(hcomp->Init.TriggerMode));
    
    /* Get the Exti Line output configuration */
    extiline = __HAL_COMP_GET_EXTI_LINE(hcomp->Instance);
    
    /* Configure the rising edge */
    /* COMP TriggerMode set to COMP_TRIGGERMODE_IT_RISING or                  */
    /* COMP_TRIGGERMODE_IT_RISING_FALLING.                                    */
    if((hcomp->Init.TriggerMode & COMP_TRIGGERMODE_IT_RISING) != RESET)
    {
      __HAL_COMP_EXTI_RISING_IT_ENABLE(extiline);
    }
    else
    {
      __HAL_COMP_EXTI_RISING_IT_DISABLE(extiline);
    }
    
    /* Configure the falling edge */
    /* COMP TriggerMode set to COMP_TRIGGERMODE_IT_FALLING or                 */
    /* COMP_TRIGGERMODE_IT_RISING_FALLING.                                    */
    if((hcomp->Init.TriggerMode & COMP_TRIGGERMODE_IT_FALLING) != RESET)
    {
      __HAL_COMP_EXTI_FALLING_IT_ENABLE(extiline);
    }
    else
    {
      __HAL_COMP_EXTI_FALLING_IT_DISABLE(extiline);
    }
    
    /* Enable Exti interrupt mode */
    __HAL_COMP_EXTI_ENABLE_IT(extiline);
    /* Clear COMP Exti pending bit */
    __HAL_COMP_EXTI_CLEAR_FLAG(extiline);
  }

  return status;
}

/**
  * @brief  Disable the interrupt and Stop the comparator 
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_Stop_IT(COMP_HandleTypeDef *hcomp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Disable the Exti Line interrupt mode */
  __HAL_COMP_EXTI_DISABLE_IT(__HAL_COMP_GET_EXTI_LINE(hcomp->Instance));
  
  status = HAL_COMP_Stop(hcomp);
  
  return status;
}

/**
  * @brief  Comparator IRQ Handler 
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
void HAL_COMP_IRQHandler(COMP_HandleTypeDef *hcomp)
{
  uint32_t extiline = __HAL_COMP_GET_EXTI_LINE(hcomp->Instance);
  
  /* Check COMP Exti flag */
  if(__HAL_COMP_EXTI_GET_FLAG(extiline) != RESET)
  {
    /* Clear COMP Exti pending bit */
    __HAL_COMP_EXTI_CLEAR_FLAG(extiline);

    /* COMP trigger user callback */
    HAL_COMP_TriggerCallback(hcomp);    
  }
}

/**
  * @}
  */

/** @defgroup COMP_Exported_Functions_Group3 Peripheral Control functions
 *  @brief   Peripheral Control functions
 *
@verbatim   
 ===============================================================================
                      ##### Peripheral Control functions #####
 ===============================================================================  
    [..]
    This subsection provides a set of functions allowing to control the COMP 
    management functions: Lock status, comparator output level check, IRQ
    callback (in case of usage of comparator with interruption on ExtI line).

@endverbatim
  * @{
  */

/**
  * @brief  Lock the selected comparator configuration.
  *         Caution: On STM32L1, HAL COMP lock is software lock only (not  
  *         hardware lock as on some other STM32 devices)
  * @param  hcomp: COMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_COMP_Lock(COMP_HandleTypeDef *hcomp)
{
  HAL_StatusTypeDef status = HAL_OK;

  /* Check the COMP handle allocation and lock status */
  if((hcomp == HAL_NULL) || ((hcomp->State & COMP_STATE_BIT_LOCK) != RESET))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

    /* Set lock flag */
    hcomp->State |= COMP_STATE_BIT_LOCK;
  }
  
  return status; 
}

/**
  * @brief  Return the output level (high or low) of the selected comparator. 
  *         The output level depends on the selected polarity.
  *           - Comparator output is low when the non-inverting input is at a lower
  *             voltage than the inverting input
  *           - Comparator output is high when the non-inverting input is at a higher
  *             voltage than the inverting input
  * @param  hcomp: COMP handle
  * @retval Returns the selected comparator output level: COMP_OUTPUTLEVEL_LOW or COMP_OUTPUTLEVEL_HIGH.
  *       
  */
uint32_t HAL_COMP_GetOutputLevel(COMP_HandleTypeDef *hcomp)
{
  uint32_t level = 0;
  
  /* Check the parameter */
  assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

  /* Read output level of the selected comparator */
  if(READ_BIT(COMP->CSR, __COMP_CSR_CMPXOUT(hcomp)) == RESET)
  {
    level = COMP_OUTPUTLEVEL_LOW;
  }
  else
  {
    level = COMP_OUTPUTLEVEL_HIGH;
  }
  
  return(level);
}

/**
  * @brief  Comparator callback.
  * @param  hcomp: COMP handle
  * @retval None
  */
__weak void HAL_COMP_TriggerCallback(COMP_HandleTypeDef *hcomp)
{
  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_COMP_TriggerCallback should be implemented in the user file
   */
}


/**
  * @}
  */

/** @defgroup COMP_Exported_Functions_Group4 Peripheral State functions 
 *  @brief   Peripheral State functions
 *
@verbatim   
 ===============================================================================
                      ##### Peripheral State functions #####
 ===============================================================================  
    [..]
    This subsection permit to get in run-time the status of the peripheral.

@endverbatim
  * @{
  */

/**
  * @brief  Return the COMP state
  * @param  hcomp : COMP handle
  * @retval HAL state
  */
HAL_COMP_StateTypeDef HAL_COMP_GetState(COMP_HandleTypeDef *hcomp)
{
  /* Check the COMP handle allocation */
  if(hcomp == HAL_NULL)
  {
    return HAL_COMP_STATE_RESET;
  }

  /* Check the parameter */
  assert_param(IS_COMP_ALL_INSTANCE(hcomp->Instance));

  return hcomp->State;
}
/**
  * @}
  */

/**
  * @}
  */

#endif /* HAL_COMP_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

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