/**
  ******************************************************************************
  * @file    stm32l4xx_hal_opamp.c
  * @author  MCD Application Team
  * @version V1.0.0
  * @date    26-June-2015
  * @brief   OPAMP HAL module driver.
  *          This file provides firmware functions to manage the following 
  *          functionalities of the operational amplifier(s) peripheral: 
  *           + OPAMP configuration
  *           + OPAMP calibration
  *          Thanks to
  *           + Initialization and de-initialization functions
  *           + IO operation functions
  *           + Peripheral Control functions
  *           + Peripheral State functions
  *         
  @verbatim
================================================================================
          ##### OPAMP Peripheral Features #####
================================================================================
           
  [..] The device integrates 2 operational amplifiers OPAMP1 & OPAMP2
       
       (#) The OPAMP(s) provide(s) several exclusive running modes.
       (++) Standalone mode
       (++) Programmable Gain Amplifier (PGA) mode (Resistor feedback output)
       (++) Follower mode

       (#) All OPAMP (same for all OPAMPs) can operate in
       (++) Either Low range (VDDA < 2.4V) power supply
       (++) Or High range (VDDA > 2.4V) power supply

       (#) Each OPAMP(s) can be configured in normal and low power mode.

       (#) The OPAMP(s) provide(s) calibration capabilities.  
       (++) Calibration aims at correcting some offset for running mode.
       (++) The OPAMP uses either factory calibration settings OR user defined 
           calibration (trimming) settings (i.e. trimming mode).
       (++) The user defined settings can be figured out using self calibration 
           handled by HAL_OPAMP_SelfCalibrate, HAL_OPAMPEx_SelfCalibrateAll
       (++) HAL_OPAMP_SelfCalibrate:
       (+++) Runs automatically the calibration.
       (+++) Enables the user trimming mode
       (+++) Updates the init structure with trimming values with fresh calibration 
            results. 
            The user may store the calibration results for larger 
            (ex monitoring the trimming as a function of temperature 
            for instance)
       (+++) HAL_OPAMPEx_SelfCalibrateAll
            runs calibration of all OPAMPs in parallel to save search time.
                    
       (#) Running mode: Standalone mode 
       (++) Gain is set externally (gain depends on external loads).
       (++) Follower mode also possible externally by connecting the inverting input to
           the output.
       
       (#) Running mode: Follower mode
       (++) No Inverting Input is connected.
       
       (#) Running mode: Programmable Gain Amplifier (PGA) mode 
           (Resistor feedback output)
       (++) The OPAMP(s) output(s) can be internally connected to resistor feedback
           output.
       (++) OPAMP gain is either 2, 4, 8 or 16.
        
       (#) The OPAMPs inverting input can be 
           selected among the list shown by table below.
       
       (#) The OPAMPs non inverting input can be 
           selected among the list shown by table below.
       
   [..] Table 1.  OPAMPs inverting/non-inverting inputs for the STM32L4 devices:
     
       (+) +------------------------------------------------------------------------|     
       (+) |                 |         | OPAMP1               | OPAMP2              |
       (+) |-----------------|---------|----------------------|---------------------|
       (+) | Inverting Input | VM_SEL  |                      |                     |
       (+) |                 |         |  IO0-> PA1           | IO0-> PA7           |
       (+) |                 |         |  LOW LEAKAGE IO (2)  | LOW LEAKAGE IO (2)  |
       (+) |                 |         |  Not connected       | Not connected       |
       (+) | (1)             |         |    PGA mode only     |   PGA mode only     |
       (+) |-----------------|---------|----------------------|---------------------|
       (+) |  Non Inverting  | VM_SEL  |                      |                     |
       (+) |                 |         |  IO0-> PA0 (GPIO)    | IO0-> PA6  (GPIO)   |
       (+) |    Input        |         |  DAC1_OUT1 internal  | DAC1_OUT2 internal  |
       (+) +------------------------------------------------------------------------|
       [..] (1): NA in follower mode.
       [..](2): Available on some package only (ex. BGA132).
           
   [..] Table 2.  OPAMPs outputs for the STM32L4 devices:

       (+) +-------------------------------------------------------------------------     
       (+) |                 |        | OPAMP1                | OPAMP2              |
       (+) |-----------------|--------|-----------------------|---------------------|
       (+) | Output          |  VOUT  |  PA3                  |  PB0                |
       (+) |                 |        |  & (2) ADC12_IN if    | & (2) ADC12_IN if   |
       (+) |                 |        |  connected internally | connected internally|
       (+) |-----------------|--------|-----------------------|---------------------|
    [..] (2): ADC1 or ADC2 shall select IN15.
      
            ##### How to use this driver #####
================================================================================
  [..] 

    *** Power supply range ***
    ============================================
    [..] To run in low power mode:

      (#) Configure the OPAMP using HAL_OPAMP_Init() function:
      (++) Select OPAMP_POWERSUPPLY_LOW (VDDA lower than 2.4V)
      (++) Otherwise select OPAMP_POWERSUPPLY_HIGH (VDDA higher than 2.4V)

    *** Low / normal power mode ***
    ============================================
    [..] To run in low power mode:

      (#) Configure the OPAMP using HAL_OPAMP_Init() function:
      (++) Select OPAMP_POWERMODE_LOWPOWER
      (++) Otherwise select OPAMP_POWERMODE_NORMAL

    *** Calibration ***
    ============================================
    [..] To run the OPAMP calibration self calibration:

      (#) Start calibration using HAL_OPAMP_SelfCalibrate. 
           Store the calibration results.

    *** Running mode ***
    ============================================
      
    [..] To use the OPAMP, perform the following steps:
            
      (#) Fill in the HAL_OPAMP_MspInit() to
      (++) Enable the OPAMP Peripheral clock using macro __HAL_RCC_OPAMP_CLK_ENABLE()
      (++) Configure the OPAMP input AND output in analog mode using 
           HAL_GPIO_Init() to map the OPAMP output to the GPIO pin.
  
      (#) Configure the OPAMP using HAL_OPAMP_Init() function:
      (++) Select the mode
      (++) Select the inverting input
      (++) Select the non-inverting input 
      (++) If PGA mode is enabled, Select if inverting input is connected.
      (++) Select either factory or user defined trimming mode.
      (++) If the user-defined trimming mode is enabled, select PMOS & NMOS trimming values
          (typically values set by HAL_OPAMP_SelfCalibrate function).
      
      (#) Enable the OPAMP using HAL_OPAMP_Start() function.
           
      (#) Disable the OPAMP using HAL_OPAMP_Stop() function.
      
      (#) Lock the OPAMP in running mode using HAL_OPAMP_Lock() function.
          Caution: On STM32L4, HAL OPAMP lock is software lock only (not 
          hardware lock as on some other STM32 devices)

      (#) If needed, unlock the OPAMP using HAL_OPAMPEx_Unlock() function.

    *** Running mode: change of configuration while OPAMP ON  ***
    ============================================
    [..] To Re-configure OPAMP when OPAMP is ON (change on the fly)
      (#) If needed, fill in the HAL_OPAMP_MspInit()
      (++) This is the case for instance if you wish to use new OPAMP I/O

      (#) Configure the OPAMP using HAL_OPAMP_Init() function:
      (++) As in configure case, select first the parameters you wish to modify.
      
      (#) Change from low power mode to normal power mode (& vice versa) requires  
          first HAL_OPAMP_DeInit() (force OPAMP OFF) and then HAL_OPAMP_Init(). 
          In other words, of OPAMP is ON, HAL_OPAMP_Init can NOT change power mode
          alone.

  @endverbatim
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2015 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 "stm32l4xx_hal.h"
    
/** @addtogroup STM32L4xx_HAL_Driver
  * @{
  */

/** @defgroup OPAMP OPAMP
  * @brief OPAMP module driver
  * @{
  */

#ifdef HAL_OPAMP_MODULE_ENABLED

/* Private types -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
/** @addtogroup OPAMP_Private_Constants
  * @{
  */

/* CSR register reset value */ 
#define OPAMP_CSR_RESET_VALUE             ((uint32_t)0x00000000)

#define OPAMP_CSR_RESET_BITS    (OPAMP_CSR_OPAMPxEN | OPAMP_CSR_OPALPM | OPAMP_CSR_OPAMODE \
                               | OPAMP_CSR_PGGAIN | OPAMP_CSR_VMSEL | OPAMP_CSR_VPSEL \
                               | OPAMP_CSR_CALON | OPAMP_CSR_USERTRIM)

/* CSR Init masks */
#define OPAMP_CSR_INIT_MASK_PGA (OPAMP_CSR_OPALPM | OPAMP_CSR_OPAMODE| OPAMP_CSR_PGGAIN \
                               | OPAMP_CSR_VMSEL | OPAMP_CSR_VPSEL | OPAMP_CSR_USERTRIM)

#define OPAMP_CSR_INIT_MASK_FOLLOWER (OPAMP_CSR_OPALPM | OPAMP_CSR_OPAMODE| OPAMP_CSR_VPSEL \
                                    | OPAMP_CSR_USERTRIM)

#define OPAMP_CSR_INIT_MASK_STANDALONE (OPAMP_CSR_OPALPM | OPAMP_CSR_OPAMODE| OPAMP_CSR_VPSEL \
                                      | OPAMP_CSR_VMSEL | OPAMP_CSR_USERTRIM)


/**
  * @}
  */ 

/* Private macros ------------------------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/* Exported functions --------------------------------------------------------*/

/** @defgroup OPAMP_Exported_Functions OPAMP Exported Functions
  * @{
  */

/** @defgroup OPAMP_Exported_Functions_Group1 Initialization and de-initialization functions 
 *  @brief    Initialization and Configuration functions 
 *
@verbatim    
  ==============================================================================
              ##### Initialization and de-initialization functions #####
  ==============================================================================
 
@endverbatim
  * @{
  */

/**
  * @brief  Initializes the OPAMP according to the specified
  *         parameters in the OPAMP_InitTypeDef and initialize the associated handle.
  * @note   If the selected opamp is locked, initialization can't be performed.
  *         To unlock the configuration, perform a system reset.
  * @param  hopamp: OPAMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_OPAMP_Init(OPAMP_HandleTypeDef *hopamp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  uint32_t updateotrlpotr = 0;

  /* Check the OPAMP handle allocation and lock status */
  /* Init not allowed if calibration is ongoing */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED)
                      || (hopamp->State == HAL_OPAMP_STATE_CALIBBUSY))
  {
    return HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));
       
    /* Set OPAMP parameters */
    assert_param(IS_OPAMP_POWER_SUPPLY_RANGE(hopamp->Init.PowerSupplyRange));
    assert_param(IS_OPAMP_POWERMODE(hopamp->Init.PowerMode));
    assert_param(IS_OPAMP_FUNCTIONAL_NORMALMODE(hopamp->Init.Mode));
    assert_param(IS_OPAMP_NONINVERTING_INPUT(hopamp->Init.NonInvertingInput));
    
    if ((hopamp->Init.Mode) == OPAMP_STANDALONE_MODE)
    {
      assert_param(IS_OPAMP_INVERTING_INPUT_STANDALONE(hopamp->Init.InvertingInput));
    }

    if ((hopamp->Init.Mode) == OPAMP_PGA_MODE)      
    {
      assert_param(IS_OPAMP_INVERTING_INPUT_PGA(hopamp->Init.InvertingInput));
    }
    
    if ((hopamp->Init.Mode) == OPAMP_PGA_MODE)
    {
      assert_param(IS_OPAMP_PGA_GAIN(hopamp->Init.PgaGain));
    }
    
    assert_param(IS_OPAMP_TRIMMING(hopamp->Init.UserTrimming)); 
    if ((hopamp->Init.UserTrimming) == OPAMP_TRIMMING_USER)
    {
      if (hopamp->Init.PowerMode == OPAMP_POWERMODE_NORMAL)
      {
        assert_param(IS_OPAMP_TRIMMINGVALUE(hopamp->Init.TrimmingValueP));
        assert_param(IS_OPAMP_TRIMMINGVALUE(hopamp->Init.TrimmingValueN));
      }
    else
      {
        assert_param(IS_OPAMP_TRIMMINGVALUE(hopamp->Init.TrimmingValuePLowPower));
        assert_param(IS_OPAMP_TRIMMINGVALUE(hopamp->Init.TrimmingValueNLowPower));
      }
    }
     
    if(hopamp->State == HAL_OPAMP_STATE_RESET)
    {
      /* Allocate lock resource and initialize it */
      hopamp->Lock = HAL_UNLOCKED;
    }

    /* Call MSP init function */
    HAL_OPAMP_MspInit(hopamp);

    /* Set operating mode */
    CLEAR_BIT(hopamp->Instance->CSR, OPAMP_CSR_CALON);
                                              
    if (hopamp->Init.Mode == OPAMP_PGA_MODE)
    {
      MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_INIT_MASK_PGA, \
                                        hopamp->Init.PowerMode | \
                                        hopamp->Init.Mode | \
                                        hopamp->Init.PgaGain | \
                                        hopamp->Init.InvertingInput    | \
                                        hopamp->Init.NonInvertingInput | \
                                        hopamp->Init.UserTrimming);
    }
    
    if (hopamp->Init.Mode == OPAMP_FOLLOWER_MODE)
    {
    /* In Follower mode InvertingInput is Not Applicable  */
    MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_INIT_MASK_FOLLOWER, \
                                        hopamp->Init.PowerMode | \
                                        hopamp->Init.Mode | \
                                        hopamp->Init.NonInvertingInput | \
                                        hopamp->Init.UserTrimming);     
    }     
    
    if (hopamp->Init.Mode == OPAMP_STANDALONE_MODE)
    {
      MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_INIT_MASK_STANDALONE, \
                                        hopamp->Init.PowerMode | \
                                        hopamp->Init.Mode | \
                                        hopamp->Init.InvertingInput    | \
                                        hopamp->Init.NonInvertingInput | \
                                        hopamp->Init.UserTrimming);
    } 
    
    if (hopamp->Init.UserTrimming == OPAMP_TRIMMING_USER)
    {
      /* Set power mode and associated calibration parameters */
      if (hopamp->Init.PowerMode != OPAMP_POWERMODE_LOWPOWER)
      {
        /* OPAMP_POWERMODE_NORMAL */
        /* Set calibration mode (factory or user) and values for            */
        /* transistors differential pair high (PMOS) and low (NMOS) for     */
        /* normal mode.                                                     */
        updateotrlpotr = (((hopamp->Init.TrimmingValueP) << (OPAMP_INPUT_NONINVERTING)) \
                         | (hopamp->Init.TrimmingValueN)); 
        MODIFY_REG(hopamp->Instance->OTR, OPAMP_OTR_TRIMOFFSETN | OPAMP_OTR_TRIMOFFSETP, updateotrlpotr);
      }
      else
      {
        /* OPAMP_POWERMODE_LOWPOWER */
        /* transistors differential pair high (PMOS) and low (NMOS) for     */
        /* low power mode.                                                     */
        updateotrlpotr = (((hopamp->Init.TrimmingValuePLowPower) << (OPAMP_INPUT_NONINVERTING)) \
                         | (hopamp->Init.TrimmingValueNLowPower)); 
        MODIFY_REG(hopamp->Instance->LPOTR, OPAMP_OTR_TRIMOFFSETN | OPAMP_OTR_TRIMOFFSETP, updateotrlpotr);     
      }
    } 

    /* Configure the power supply range */
    /* The OPAMP_CSR_OPARANGE is common configuration for all OPAMPs */
    /* bit OPAMP1_CSR_OPARANGE is used for both OPAMPs */
    MODIFY_REG(OPAMP1->CSR, OPAMP1_CSR_OPARANGE, hopamp->Init.PowerSupplyRange);
    
    /* Update the OPAMP state*/
    if (hopamp->State == HAL_OPAMP_STATE_RESET)
    {
      /* From RESET state to READY State */
      hopamp->State = HAL_OPAMP_STATE_READY;
    }
    /* else: remain in READY or BUSY state (no update) */
    return status;
  }
}

/**
  * @brief  DeInitialize the OPAMP peripheral.
  * @note   Deinitialization can be performed if the OPAMP configuration is locked.
  *         (the lock is SW in L4)
  * @param  hopamp: OPAMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_OPAMP_DeInit(OPAMP_HandleTypeDef *hopamp)
{
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Check the OPAMP handle allocation */
  /* DeInit not allowed if calibration is ongoing */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_CALIBBUSY))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));

    /* Set OPAMP_CSR register to reset value */
    /* Mind that OPAMP1_CSR_OPARANGE of CSR of OPAMP1 remains unchanged (applies to both OPAMPs) */ 
    /* OPAMP shall be disabled first separately */     
    CLEAR_BIT(hopamp->Instance->CSR, OPAMP_CSR_OPAMPxEN);
    MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_RESET_BITS, OPAMP_CSR_RESET_VALUE);
    
    /* DeInit the low level hardware: GPIO, CLOCK and NVIC */
    HAL_OPAMP_MspDeInit(hopamp);

    /* Update the OPAMP state*/
    hopamp->State = HAL_OPAMP_STATE_RESET;   
  }
  
  /* Process unlocked */
  __HAL_UNLOCK(hopamp);
  
  return status;
}


/**
  * @brief  Initialize the OPAMP MSP.
  * @param  hopamp: OPAMP handle
  * @retval None
  */
__weak void HAL_OPAMP_MspInit(OPAMP_HandleTypeDef *hopamp)
{
  /* NOTE : This function should not be modified, when the callback is needed,
            the function "HAL_OPAMP_MspInit()" must be implemented in the user file.
   */
}

/**
  * @brief  DeInitialize OPAMP MSP.
  * @param  hopamp: OPAMP handle
  * @retval None
  */
__weak void HAL_OPAMP_MspDeInit(OPAMP_HandleTypeDef *hopamp)
{
  /* NOTE : This function should not be modified, when the callback is needed,
            the function "HAL_OPAMP_MspDeInit()" must be implemented in the user file.
   */
}

/**
  * @}
  */


/** @defgroup OPAMP_Exported_Functions_Group2 IO operation functions 
 *  @brief   IO operation functions 
 *
@verbatim   
 ===============================================================================
                        ##### IO operation functions #####
 =============================================================================== 
    [..]
    This subsection provides a set of functions allowing to manage the OPAMP
    start, stop and calibration actions.

@endverbatim
  * @{
  */

/**
  * @brief  Start the OPAMP.
  * @param  hopamp: OPAMP handle
  * @retval HAL status
  */

HAL_StatusTypeDef HAL_OPAMP_Start(OPAMP_HandleTypeDef *hopamp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Check the OPAMP handle allocation */
  /* Check if OPAMP locked */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED))
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));
    
    if(hopamp->State == HAL_OPAMP_STATE_READY)
    {
      /* Enable the selected opamp */
      SET_BIT (hopamp->Instance->CSR, OPAMP_CSR_OPAMPxEN);

      /* Update the OPAMP state*/     
      /* From HAL_OPAMP_STATE_READY to HAL_OPAMP_STATE_BUSY */
      hopamp->State = HAL_OPAMP_STATE_BUSY;   
    }
    else
    {
      status = HAL_ERROR;
    }
    
   }
  return status;
}

/**
  * @brief  Stop the OPAMP.
  * @param  hopamp: OPAMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_OPAMP_Stop(OPAMP_HandleTypeDef *hopamp)
{ 
  HAL_StatusTypeDef status = HAL_OK;
    
  /* Check the OPAMP handle allocation */
  /* Check if OPAMP locked */
  /* Check if OPAMP calibration ongoing */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED) \
                      || (hopamp->State == HAL_OPAMP_STATE_CALIBBUSY))  
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));

    if(hopamp->State == HAL_OPAMP_STATE_BUSY)
    {
      /* Disable the selected opamp */
      CLEAR_BIT (hopamp->Instance->CSR, OPAMP_CSR_OPAMPxEN); 
    
      /* Update the OPAMP state*/     
      /* From  HAL_OPAMP_STATE_BUSY to HAL_OPAMP_STATE_READY*/
      hopamp->State = HAL_OPAMP_STATE_READY;
    }
    else
    {
      status = HAL_ERROR;
    }
  }
  return status;
}

/**
  * @brief  Run the self calibration of one OPAMP.
  * @note   Calibration is performed in the mode specified in OPAMP init
  *         structure (mode normal or low-power). To perform calibration for
  *         both modes, repeat this function twice after OPAMP init structure
  *         accordingly updated.
  * @note   Calibration runs about 10 ms.
  * @param  hopamp handle
  * @retval Updated offset trimming values (PMOS & NMOS), user trimming is enabled
  * @retval HAL status

  */

HAL_StatusTypeDef HAL_OPAMP_SelfCalibrate(OPAMP_HandleTypeDef *hopamp)
{ 

  HAL_StatusTypeDef status = HAL_OK;
  
  uint32_t trimmingvaluen = 0;
  uint32_t trimmingvaluep = 0;
  uint32_t delta;
  
  __IO uint32_t* tmp_opamp_reg_trimming;   /* Selection of register of trimming depending on power mode: OTR or LPOTR */
    
  /* Check the OPAMP handle allocation */
  /* Check if OPAMP locked */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED))
  {
    status = HAL_ERROR;
  }
  else
  {
  
    /* Check if OPAMP in calibration mode and calibration not yet enable */
    if(hopamp->State ==  HAL_OPAMP_STATE_READY)
    {
      /* Check the parameter */
      assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));
      assert_param(IS_OPAMP_POWERMODE(hopamp->Init.PowerMode));

      /*  user trimming values are used for offset calibration */
      SET_BIT(hopamp->Instance->CSR, OPAMP_CSR_USERTRIM);
      
      /* Select trimming settings depending on power mode */
      if (hopamp->Init.PowerMode == OPAMP_POWERMODE_NORMAL)
      {
        tmp_opamp_reg_trimming = &hopamp->Instance->OTR;
      }
      else
      {
        tmp_opamp_reg_trimming = &hopamp->Instance->LPOTR;
      }
      
      /* Enable calibration */
      SET_BIT (hopamp->Instance->CSR, OPAMP_CSR_CALON);
  
      /* 1st calibration - N */
      CLEAR_BIT (hopamp->Instance->CSR, OPAMP_CSR_CALSEL);
      
      /* Enable the selected opamp */
      SET_BIT (hopamp->Instance->CSR, OPAMP_CSR_OPAMPxEN);
      
      /* Init trimming counter */    
      /* Medium value */
      trimmingvaluen = 16; 
      delta = 8;
           
      while (delta != 0)
      {
        /* Set candidate trimming */
        /* OPAMP_POWERMODE_NORMAL */
        MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETN, trimmingvaluen);
        
        /* OFFTRIMmax delay 1 ms as per datasheet (electrical characteristics */ 
        /* Offset trim time: during calibration, minimum time needed between */
        /* two steps to have 1 mV accuracy */
        HAL_Delay(OPAMP_TRIMMING_DELAY);

        if (READ_BIT(hopamp->Instance->CSR, OPAMP_CSR_CALOUT) != RESET)
        { 
          /* OPAMP_CSR_CALOUT is HIGH try higher trimming */
          trimmingvaluen -= delta;
        }
        else
        {
          /* OPAMP_CSR_CALOUT is LOW try lower trimming */
          trimmingvaluen += delta;
        }
        /* Divide range by 2 to continue dichotomy sweep */       
        delta >>= 1;
      }

      /* Still need to check if right calibration is current value or one step below */
      /* Indeed the first value that causes the OUTCAL bit to change from 0 to 1  */
      /* Set candidate trimming */
      MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETN, trimmingvaluen);
           
      /* OFFTRIMmax delay 1 ms as per datasheet (electrical characteristics */ 
      /* Offset trim time: during calibration, minimum time needed between */
      /* two steps to have 1 mV accuracy */
      HAL_Delay(OPAMP_TRIMMING_DELAY);
      
      if ((READ_BIT(hopamp->Instance->CSR, OPAMP_CSR_CALOUT)) == 0)
      { 
        /* Trimming value is actually one value more */
        trimmingvaluen++;
        /* Set right trimming */
        MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETN, trimmingvaluen);
      }

      /* 2nd calibration - P */
      SET_BIT (hopamp->Instance->CSR, OPAMP_CSR_CALSEL);
      
      /* Init trimming counter */    
      /* Medium value */
      trimmingvaluep = 16; 
      delta = 8;
      
      while (delta != 0)
      {
        /* Set candidate trimming */
        /* OPAMP_POWERMODE_NORMAL */
        MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETP, (trimmingvaluep<<OPAMP_INPUT_NONINVERTING));

        /* OFFTRIMmax delay 1 ms as per datasheet (electrical characteristics */ 
        /* Offset trim time: during calibration, minimum time needed between */
        /* two steps to have 1 mV accuracy */
        HAL_Delay(OPAMP_TRIMMING_DELAY);

        if (READ_BIT(hopamp->Instance->CSR, OPAMP_CSR_CALOUT) != RESET)
        { 
          /* OPAMP_CSR_CALOUT is HIGH try higher trimming */
          trimmingvaluep += delta;
        }
        else
        {
          /* OPAMP_CSR_CALOUT  is LOW try lower trimming */
          trimmingvaluep -= delta;
        }
        
        /* Divide range by 2 to continue dichotomy sweep */
        delta >>= 1;
      }
      
      /* Still need to check if right calibration is current value or one step below */
      /* Indeed the first value that causes the OUTCAL bit to change from 1 to 0  */
      /* Set candidate trimming */
      MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETP, (trimmingvaluep<<OPAMP_INPUT_NONINVERTING));

      /* OFFTRIMmax delay 1 ms as per datasheet (electrical characteristics */ 
      /* Offset trim time: during calibration, minimum time needed between */
      /* two steps to have 1 mV accuracy */
      HAL_Delay(OPAMP_TRIMMING_DELAY);
      
      if (READ_BIT(hopamp->Instance->CSR, OPAMP_CSR_CALOUT) != RESET)
      {
        /* Trimming value is actually one value more */
        trimmingvaluep++;
        MODIFY_REG(*tmp_opamp_reg_trimming, OPAMP_OTR_TRIMOFFSETP, (trimmingvaluep<<OPAMP_INPUT_NONINVERTING));
      }
      
      /* Disable the OPAMP */
      CLEAR_BIT (hopamp->Instance->CSR, OPAMP_CSR_OPAMPxEN);
      
      /* Disable calibration & set normal mode (operating mode) */
      CLEAR_BIT (hopamp->Instance->CSR, OPAMP_CSR_CALON);
                 
      /* Self calibration is successful  */
      /* Store calibration(user trimming) results in init structure. */

      /* Set user trimming mode */  
      hopamp->Init.UserTrimming = OPAMP_TRIMMING_USER;

      /* Affect calibration parameters depending on mode normal/low power */
      if (hopamp->Init.PowerMode != OPAMP_POWERMODE_LOWPOWER)
      {
        /* Write calibration result N */
        hopamp->Init.TrimmingValueN = trimmingvaluen;
        /* Write calibration result P */
        hopamp->Init.TrimmingValueP = trimmingvaluep;
      }
      else
      {
        /* Write calibration result N */
        hopamp->Init.TrimmingValueNLowPower = trimmingvaluen;
        /* Write calibration result P */
        hopamp->Init.TrimmingValuePLowPower = trimmingvaluep;
      }
    }

    else
    {
      /* OPAMP can not be calibrated from this mode */ 
      status = HAL_ERROR;
    }   
  }
  return status;
}

/**
  * @}
  */

/** @defgroup OPAMP_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 OPAMP data 
    transfers.



@endverbatim
  * @{
  */

/**
  * @brief  Lock the selected OPAMP configuration.
  * @note   On STM32L4, HAL OPAMP lock is software lock only (in 
  *         contrast of hardware lock available on some other STM32 
  *         devices).
  * @param  hopamp: OPAMP handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_OPAMP_Lock(OPAMP_HandleTypeDef *hopamp)
{
  HAL_StatusTypeDef status = HAL_OK;

  /* Check the OPAMP handle allocation */
  /* Check if OPAMP locked */
  /* OPAMP can be locked when enabled and running in normal mode */ 
  /*   It is meaningless otherwise */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_RESET) \
                      || (hopamp->State == HAL_OPAMP_STATE_READY) \
                      || (hopamp->State == HAL_OPAMP_STATE_CALIBBUSY)\
                      || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED))
  
  {
    status = HAL_ERROR;
  }
  
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));
    
   /* OPAMP state changed to locked */
    hopamp->State = HAL_OPAMP_STATE_BUSYLOCKED;
  }
  return status; 
}

/**
  * @brief  Return the OPAMP factory trimming value.
  * @note            On STM32L4 OPAMP, user can retrieve factory trimming if 
  *                  OPAMP has never been set to user trimming before.
  *                  Therefore, this function must be called when OPAMP init  
  *                  parameter "UserTrimming" is set to trimming factory, 
  *                  and before OPAMP  calibration (function 
  *                  "HAL_OPAMP_SelfCalibrate()").
  *                  Otherwise, factory trimming value cannot be retrieved and 
  *                  error status is returned.
  * @param  hopamp : OPAMP handle
  * @param  trimmingoffset : Trimming offset (P or N)
  *         This parameter must be a value of @ref OPAMP_FactoryTrimming
  * @note   Calibration parameter retrieved is corresponding to the mode 
  *         specified in OPAMP init structure (mode normal or low-power). 
  *         To retrieve calibration parameters for both modes, repeat this 
  *         function after OPAMP init structure accordingly updated.
  * @retval Trimming value (P or N): range: 0->31
  *         or OPAMP_FACTORYTRIMMING_DUMMY if trimming value is not available
  *
  */

HAL_OPAMP_TrimmingValueTypeDef HAL_OPAMP_GetTrimOffset (OPAMP_HandleTypeDef *hopamp, uint32_t trimmingoffset)
{
  HAL_OPAMP_TrimmingValueTypeDef trimmingvalue;
  __IO uint32_t* tmp_opamp_reg_trimming;  /* Selection of register of trimming depending on power mode: OTR or LPOTR */
  
  /* Check the OPAMP handle allocation */
  /* Value can be retrieved in HAL_OPAMP_STATE_READY state */
  if((hopamp == NULL) || (hopamp->State == HAL_OPAMP_STATE_RESET) \
                      || (hopamp->State == HAL_OPAMP_STATE_BUSY) \
                      || (hopamp->State == HAL_OPAMP_STATE_CALIBBUSY)\
                      || (hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED))
  {
    return OPAMP_FACTORYTRIMMING_DUMMY;
  }
  else
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));
    assert_param(IS_OPAMP_FACTORYTRIMMING(trimmingoffset));
    assert_param(IS_OPAMP_POWERMODE(hopamp->Init.PowerMode));
    
    /* Check the trimming mode */
    if (READ_BIT(hopamp->Instance->CSR,OPAMP_CSR_USERTRIM) != RESET)
    {
      /* This function must called when OPAMP init parameter "UserTrimming"   */
      /* is set to trimming factory, and before OPAMP calibration (function   */
      /* "HAL_OPAMP_SelfCalibrate()").                                        */
      /* Otherwise, factory trimming value cannot be retrieved and error       */
      /* status is returned.                                                  */
      trimmingvalue = OPAMP_FACTORYTRIMMING_DUMMY;
    }
    else
    {
      /* Select trimming settings depending on power mode */
      if (hopamp->Init.PowerMode == OPAMP_POWERMODE_NORMAL)
      {
        tmp_opamp_reg_trimming = &OPAMP->OTR;
      }
      else
      {
        tmp_opamp_reg_trimming = &OPAMP->LPOTR;
      }      
    
      /* Get factory trimming  */
      if (trimmingoffset == OPAMP_FACTORYTRIMMING_P)
      {
        /* OPAMP_FACTORYTRIMMING_P */
        trimmingvalue = ((*tmp_opamp_reg_trimming) & OPAMP_OTR_TRIMOFFSETP) >> OPAMP_INPUT_NONINVERTING;
      }
      else
      {
        /* OPAMP_FACTORYTRIMMING_N */
        trimmingvalue = (*tmp_opamp_reg_trimming) & OPAMP_OTR_TRIMOFFSETN;
      }
    }
  }  
  return trimmingvalue;
}

/**
  * @}
  */


/** @defgroup OPAMP_Exported_Functions_Group4 Peripheral State functions 
 *  @brief   Peripheral State functions 
 *
@verbatim   
 ===============================================================================
                      ##### Peripheral State functions #####
 =============================================================================== 
    [..]
    This subsection permits to get in run-time the status of the peripheral.

@endverbatim
  * @{
  */

/**
  * @brief  Return the OPAMP handle state.
  * @param  hopamp : OPAMP handle
  * @retval HAL state
  */
HAL_OPAMP_StateTypeDef HAL_OPAMP_GetState(OPAMP_HandleTypeDef *hopamp)
{
  /* Check the OPAMP handle allocation */
  if(hopamp == NULL)
  {
    return HAL_OPAMP_STATE_RESET;
  }

  /* Check the parameter */
  assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));

  /* Return OPAMP handle state */
  return hopamp->State;
}

/**
  * @}
  */

/**
  * @}
  */
  
  /**
  * @}
  */ 
  
#endif /* HAL_OPAMP_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

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