Src/stm32l4xx_hal_opamp.c

/**
  ******************************************************************************
  * @file    stm32l4xx_hal_opamp.c
  * @author  MCD Application Team
  * @brief   OPAMP HAL module driver.
  *          This file provides firmware functions to manage the following
  *          functionalities of the operational amplifier(s) peripheral:
  *           + Initialization and de-initialization functions
  *           + IO operation functions
  *           + Peripheral Control functions
  *           + Peripheral State functions
  *
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  @verbatim
================================================================================
          ##### OPAMP Peripheral Features #####
================================================================================

  [..] The device integrates 1 or 2 operational amplifiers OPAMP1 & OPAMP2

       (#) The OPAMP(s) provide(s) several exclusive running modes.
       (++) 1 OPAMP: STM32L412xx STM32L422xx STM32L431xx STM32L432xx STM32L433xx STM32L442xx STM32L443xx
       (++) 2 OPAMP: STM32L471xx STM32L475xx STM32L476xx STM32L485xx STM32L486xx

       (#) 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 according to the Reference Manual
           "OPAMP function description" chapter.

       (#) The OPAMPs non inverting input can be selected according to the Reference Manual
           "OPAMP function description" chapter.


            ##### 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_NORMALPOWER

    *** 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.

      (#) Registrate Callbacks
      (++) The compilation define  USE_HAL_OPAMP_REGISTER_CALLBACKS when set to 1
           allows the user to configure dynamically the driver callbacks.

      (++) Use Functions HAL_OPAMP_RegisterCallback() to register a user callback,
           it allows to register following callbacks:
      (+++) MspInitCallback         : OPAMP MspInit.
      (+++) MspDeInitCallback       : OPAMP MspFeInit.
           This function takes as parameters the HAL peripheral handle, the Callback ID
           and a pointer to the user callback function.

      (++) Use function HAL_OPAMP_UnRegisterCallback() to reset a callback to the default
           weak (overridden) function. It allows to reset following callbacks:
      (+++) MspInitCallback         : OPAMP MspInit.
      (+++) MspDeInitCallback       : OPAMP MspdeInit.
      (+++) All Callbacks

      (#) 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
  ******************************************************************************

      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  | VP_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                |
      |                 |        |  & (1) ADC12_IN if    | & (1) ADC12_IN if   |
      |                 |        |  connected internally | connected internally|
      |-----------------|--------|-----------------------|---------------------|
       (1): ADC1 or ADC2 shall select IN15.

  */

/* 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;

  /* Check the OPAMP handle allocation and lock status */
  /* Init not allowed if calibration is ongoing */
  if(hopamp == NULL)
  {
    return HAL_ERROR;
  }
  else if(hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED)
  {
    return HAL_ERROR;
  }
  else if(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 (USE_HAL_OPAMP_REGISTER_CALLBACKS == 1)
    if(hopamp->State == HAL_OPAMP_STATE_RESET)
    {
      if(hopamp->MspInitCallback == NULL)
      {
        hopamp->MspInitCallback               = HAL_OPAMP_MspInit;
      }
    }
#endif /* USE_HAL_OPAMP_REGISTER_CALLBACKS */

    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_NORMALPOWER)
      {
        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;
    }

#if (USE_HAL_OPAMP_REGISTER_CALLBACKS == 1)
    hopamp->MspInitCallback(hopamp);
#else
    /* Call MSP init function */
    HAL_OPAMP_MspInit(hopamp);
#endif /* USE_HAL_OPAMP_REGISTER_CALLBACKS */

    /* 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_NORMALPOWER */
        /* 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)
  {
    status = HAL_ERROR;
  }
  else if(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);

#if (USE_HAL_OPAMP_REGISTER_CALLBACKS == 1)
  if(hopamp->MspDeInitCallback == NULL)
  {
    hopamp->MspDeInitCallback = HAL_OPAMP_MspDeInit;
  }
  /* DeInit the low level hardware */
  hopamp->MspDeInitCallback(hopamp);
#else
    /* DeInit the low level hardware: GPIO, CLOCK and NVIC */
    HAL_OPAMP_MspDeInit(hopamp);
#endif /* USE_HAL_OPAMP_REGISTER_CALLBACKS */
    /* 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)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(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)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(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)
  {
    status = HAL_ERROR;
  }
  else if(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)
  {
    status = HAL_ERROR;
  }
  else if(hopamp->State == HAL_OPAMP_STATE_BUSYLOCKED)
  {
    status = HAL_ERROR;
  }
  else if(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;
  uint32_t trimmingvaluep;
  uint32_t delta;
  uint32_t opampmode;

  __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)
  {
    status = HAL_ERROR;
  }
  else if(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));

      /* Save OPAMP mode as in                                       */
      /* STM32L471xx STM32L475xx STM32L476xx STM32L485xx STM32L486xx */
      /* the calibration is not working in PGA mode                  */
      opampmode = READ_BIT(hopamp->Instance->CSR,OPAMP_CSR_OPAMODE);

      /* Use of standalone mode */
      MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_OPAMODE, OPAMP_STANDALONE_MODE);

      /*  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_NORMALPOWER)
      {
        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 = 16U;
      delta = 8U;

      while (delta != 0U)
      {
        /* Set candidate trimming */
        /* OPAMP_POWERMODE_NORMALPOWER */
        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) != 0U)
        {
          /* 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 >>= 1U;
      }

      /* 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)) == 0U)
      {
        /* 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 = 16U;
      delta = 8U;

      while (delta != 0U)
      {
        /* Set candidate trimming */
        /* OPAMP_POWERMODE_NORMALPOWER */
        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) != 0U)
        {
          /* 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 >>= 1U;
      }

      /* 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) != 0U)
      {
        /* 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;
      }

    /* Restore OPAMP mode after calibration */
    MODIFY_REG(hopamp->Instance->CSR, OPAMP_CSR_OPAMODE, opampmode);
    }
    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)
  {
    status = HAL_ERROR;
  }
  else if(hopamp->State == HAL_OPAMP_STATE_BUSY)
  {
    /* Check the parameter */
    assert_param(IS_OPAMP_ALL_INSTANCE(hopamp->Instance));

   /* OPAMP state changed to locked */
    hopamp->State = HAL_OPAMP_STATE_BUSYLOCKED;
  }
  else
  {
    status = HAL_ERROR;
  }
  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)
  {
    return OPAMP_FACTORYTRIMMING_DUMMY;
  }

  /* Check the OPAMP handle allocation */
  /* Value can be retrieved in HAL_OPAMP_STATE_READY state */
  if(hopamp->State == HAL_OPAMP_STATE_READY)
  {
    /* 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) != 0U)
    {
      /* 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_NORMALPOWER)
      {
        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;
      }
    }
  }
  else
  {
    return OPAMP_FACTORYTRIMMING_DUMMY;
  }
  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;
}

/**
  * @}
  */

#if (USE_HAL_OPAMP_REGISTER_CALLBACKS == 1)
/**
  * @brief  Register a User OPAMP Callback
  *         To be used instead of the weak (overridden) predefined callback
  * @param hopamp : OPAMP handle
  * @param CallbackID : ID of the callback to be registered
  *        This parameter can be one of the following values:
  *          @arg @ref HAL_OPAMP_MSPINIT_CB_ID       OPAMP MspInit callback ID
  *          @arg @ref HAL_OPAMP_MSPDEINIT_CB_ID     OPAMP MspDeInit callback ID
  * @param pCallback : pointer to the Callback function
  * @retval status
  */
HAL_StatusTypeDef HAL_OPAMP_RegisterCallback (OPAMP_HandleTypeDef *hopamp, HAL_OPAMP_CallbackIDTypeDef CallbackID, pOPAMP_CallbackTypeDef pCallback)
{
  HAL_StatusTypeDef status = HAL_OK;

  if(pCallback == NULL)
  {
    return HAL_ERROR;
  }

  /* Process locked */
  __HAL_LOCK(hopamp);

  if(hopamp->State == HAL_OPAMP_STATE_READY)
  {
    switch (CallbackID)
    {
    case HAL_OPAMP_MSPINIT_CB_ID :
      hopamp->MspInitCallback = pCallback;
      break;
    case HAL_OPAMP_MSPDEINIT_CB_ID :
      hopamp->MspDeInitCallback = pCallback;
      break;
    default :
      /* update return status */
      status =  HAL_ERROR;
      break;
    }
  }
  else if (hopamp->State == HAL_OPAMP_STATE_RESET)
  {
    switch (CallbackID)
    {
    case HAL_OPAMP_MSPINIT_CB_ID :
      hopamp->MspInitCallback = pCallback;
      break;
    case HAL_OPAMP_MSPDEINIT_CB_ID :
      hopamp->MspDeInitCallback = pCallback;
      break;
    default :
      /* update return status */
      status =  HAL_ERROR;
      break;
    }
  }
  else
  {
    /* update return status */
    status =  HAL_ERROR;
  }

  /* Release Lock */
  __HAL_UNLOCK(hopamp);
  return status;
}

/**
  * @brief  Unregister a User OPAMP Callback
  *         OPAMP Callback is redirected to the weak (overridden) predefined callback
  * @param hopamp : OPAMP handle
  * @param CallbackID : ID of the callback to be unregistered
  *        This parameter can be one of the following values:
  *          @arg @ref HAL_OPAMP_MSPINIT_CB_ID              OPAMP MSP Init Callback ID
  *          @arg @ref HAL_OPAMP_MSPDEINIT_CB_ID            OPAMP MSP DeInit Callback ID
  *          @arg @ref HAL_OPAMP_ALL_CB_ID                   OPAMP All Callbacks
  * @retval status
  */

HAL_StatusTypeDef HAL_OPAMP_UnRegisterCallback (OPAMP_HandleTypeDef *hopamp, HAL_OPAMP_CallbackIDTypeDef CallbackID)
{
  HAL_StatusTypeDef status = HAL_OK;

  /* Process locked */
  __HAL_LOCK(hopamp);

  if(hopamp->State == HAL_OPAMP_STATE_READY)
  {
    switch (CallbackID)
    {
      case HAL_OPAMP_MSPINIT_CB_ID :
      hopamp->MspInitCallback = HAL_OPAMP_MspInit;
      break;
    case HAL_OPAMP_MSPDEINIT_CB_ID :
      hopamp->MspDeInitCallback = HAL_OPAMP_MspDeInit;
      break;
    case HAL_OPAMP_ALL_CB_ID :
      hopamp->MspInitCallback = HAL_OPAMP_MspInit;
      hopamp->MspDeInitCallback = HAL_OPAMP_MspDeInit;
      break;
    default :
      /* update return status */
      status =  HAL_ERROR;
      break;
    }
  }
  else if (hopamp->State == HAL_OPAMP_STATE_RESET)
  {
    switch (CallbackID)
    {
    case HAL_OPAMP_MSPINIT_CB_ID :
      hopamp->MspInitCallback = HAL_OPAMP_MspInit;
      break;
    case HAL_OPAMP_MSPDEINIT_CB_ID :
      hopamp->MspDeInitCallback = HAL_OPAMP_MspDeInit;
      break;
    default :
      /* update return status */
      status =  HAL_ERROR;
      break;
    }
  }
  else
  {
    /* update return status */
    status =  HAL_ERROR;
  }

  /* Release Lock */
  __HAL_UNLOCK(hopamp);
  return status;
}

#endif /* USE_HAL_OPAMP_REGISTER_CALLBACKS */


/**
  * @}
  */

  /**
  * @}
  */

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

/**
  * @}
  */