/**
  ******************************************************************************
  * @file    stm32f0xx_hal_crc.c
  * @author  MCD Application Team
  * @brief   CRC HAL module driver.
  *          This file provides firmware functions to manage the following 
  *          functionalities of the Cyclic Redundancy Check (CRC) peripheral:
  *           + Initialization and de-initialization functions
  *           + Peripheral Control functions 
  *           + Peripheral State functions
  *         
  @verbatim
 ===============================================================================
                     ##### How to use this driver #####
 ===============================================================================
    [..]
         (+) Enable CRC AHB clock using __HAL_RCC_CRC_CLK_ENABLE();
         (+) Initialize CRC calculator
             (++)specify generating polynomial (IP default or non-default one)
             (++)specify initialization value (IP default or non-default one)
             (++)specify input data format
             (++)specify input or output data inversion mode if any
         (+) Use HAL_CRC_Accumulate() function to compute the CRC value of the 
             input data buffer starting with the previously computed CRC as 
             initialization value
         (+) Use HAL_CRC_Calculate() function to compute the CRC value of the 
             input data buffer starting with the defined initialization value 
             (default or non-default) to initiate CRC calculation

  @endverbatim
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2016 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 "stm32f0xx_hal.h"

/** @addtogroup STM32F0xx_HAL_Driver
  * @{
  */

/** @defgroup CRC CRC
  * @brief CRC HAL module driver.
  * @{
  */

#ifdef HAL_CRC_MODULE_ENABLED

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/** @defgroup CRC_Private_Functions CRC Private Functions
  * @{
  */
static uint32_t CRC_Handle_8(CRC_HandleTypeDef *hcrc, uint8_t pBuffer[], uint32_t BufferLength);
static uint32_t CRC_Handle_16(CRC_HandleTypeDef *hcrc, uint16_t pBuffer[], uint32_t BufferLength);
/**
  * @}
  */

/* Exported functions --------------------------------------------------------*/

/** @defgroup CRC_Exported_Functions CRC Exported Functions
  * @{
  */

/** @defgroup CRC_Exported_Functions_Group1 Initialization/de-initialization functions
 *  @brief    Initialization and Configuration functions. 
 *
@verbatim    
 ===============================================================================
            ##### Initialization and de-initialization functions #####
 ===============================================================================
    [..]  This section provides functions allowing to:
      (+) Initialize the CRC according to the specified parameters 
          in the CRC_InitTypeDef and create the associated handle
      (+) DeInitialize the CRC peripheral
      (+) Initialize the CRC MSP (MCU Specific Package)
      (+) DeInitialize the CRC MSP
 
@endverbatim
  * @{
  */

/**
  * @brief  Initialize the CRC according to the specified
  *         parameters in the CRC_InitTypeDef and initialize the associated handle.
  * @param  hcrc CRC handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_CRC_Init(CRC_HandleTypeDef *hcrc)
{
  /* Check the CRC handle allocation */
  if(hcrc == NULL)
  {
    return HAL_ERROR;
  }
  
  /* Check the parameters */
  assert_param(IS_CRC_ALL_INSTANCE(hcrc->Instance));

  if(hcrc->State == HAL_CRC_STATE_RESET)
  {   
    /* Allocate lock resource and initialize it */
    hcrc->Lock = HAL_UNLOCKED;

    /* Init the low level hardware */
    HAL_CRC_MspInit(hcrc);
  }
  
  hcrc->State = HAL_CRC_STATE_BUSY; 
  
  /* Extended initialization: if programmable polynomial feature is 
     applicable to device, set default or non-default generating 
     polynomial according to hcrc->Init parameters.
     If feature is non-applicable to device in use, HAL_CRCEx_Init straight 
     away reports HAL_OK. */
  if (HAL_CRCEx_Init(hcrc) != HAL_OK)
  {
    return HAL_ERROR;
  }
  
  /* check whether or not non-default CRC initial value has been 
   * picked up by user */
  assert_param(IS_DEFAULT_INIT_VALUE(hcrc->Init.DefaultInitValueUse));
  if (hcrc->Init.DefaultInitValueUse == DEFAULT_INIT_VALUE_ENABLE)
  {
    WRITE_REG(hcrc->Instance->INIT, DEFAULT_CRC_INITVALUE);  
  }
  else
  {
    WRITE_REG(hcrc->Instance->INIT, hcrc->Init.InitValue);
  }
  

  /* set input data inversion mode */
  assert_param(IS_CRC_INPUTDATA_INVERSION_MODE(hcrc->Init.InputDataInversionMode)); 
  MODIFY_REG(hcrc->Instance->CR, CRC_CR_REV_IN, hcrc->Init.InputDataInversionMode); 
  
  /* set output data inversion mode */
  assert_param(IS_CRC_OUTPUTDATA_INVERSION_MODE(hcrc->Init.OutputDataInversionMode)); 
  MODIFY_REG(hcrc->Instance->CR, CRC_CR_REV_OUT, hcrc->Init.OutputDataInversionMode);  
  
  /* makes sure the input data format (bytes, halfwords or words stream)
   * is properly specified by user */
  assert_param(IS_CRC_INPUTDATA_FORMAT(hcrc->InputDataFormat));

  /* Change CRC peripheral state */
  hcrc->State = HAL_CRC_STATE_READY;
  
  /* Return function status */
  return HAL_OK;
}

/**
  * @brief  DeInitialize the CRC peripheral. 
  * @param  hcrc CRC handle
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_CRC_DeInit(CRC_HandleTypeDef *hcrc)
{ 
  /* Check the CRC handle allocation */
  if(hcrc == NULL)
  {
    return HAL_ERROR;
  }
  
  /* Check the parameters */
  assert_param(IS_CRC_ALL_INSTANCE(hcrc->Instance));
  
  /* Check the CRC peripheral state */
  if(hcrc->State == HAL_CRC_STATE_BUSY)
  {
    return HAL_BUSY;
  }
  
  /* Change CRC peripheral state */
  hcrc->State = HAL_CRC_STATE_BUSY;
  
  /* Reset CRC calculation unit */
  __HAL_CRC_DR_RESET(hcrc);
  
  /* Reset IDR register content */
  CLEAR_BIT(hcrc->Instance->IDR, CRC_IDR_IDR) ;

  /* DeInit the low level hardware */
  HAL_CRC_MspDeInit(hcrc);

  /* Change CRC peripheral state */
  hcrc->State = HAL_CRC_STATE_RESET;

  /* Process unlocked */
  __HAL_UNLOCK(hcrc);

  /* Return function status */
  return HAL_OK;
}

/**
  * @brief  Initializes the CRC MSP.
  * @param  hcrc CRC handle
  * @retval None
  */
__weak void HAL_CRC_MspInit(CRC_HandleTypeDef *hcrc)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hcrc);

  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_CRC_MspInit can be implemented in the user file
   */
}

/**
  * @brief  DeInitialize the CRC MSP.
  * @param  hcrc CRC handle
  * @retval None
  */
__weak void HAL_CRC_MspDeInit(CRC_HandleTypeDef *hcrc)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hcrc);

  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_CRC_MspDeInit can be implemented in the user file
   */
}

/**
  * @}
  */

/** @defgroup CRC_Exported_Functions_Group2 Peripheral Control functions 
 *  @brief    management functions. 
 *
@verbatim   
 ===============================================================================
                      ##### Peripheral Control functions #####
 ===============================================================================  
    [..]  This section provides functions allowing to:
      (+) compute the 7U, 8U, 16 or 32-bit CRC value of an 8U, 16 or 32-bit data buffer
          using the combination of the previous CRC value and the new one
          
       [..]  or
          
      (+) compute the 7U, 8U, 16 or 32-bit CRC value of an 8U, 16 or 32-bit data buffer
          independently of the previous CRC value.

@endverbatim
  * @{
  */

/**                  
  * @brief  Compute the 7, 8, 16 or 32-bit CRC value of an 8, 16 or 32-bit data buffer
  *         starting with the previously computed CRC as initialization value.
  * @param  hcrc CRC handle
  * @param  pBuffer pointer to the input data buffer, exact input data format is
  *         provided by hcrc->InputDataFormat.  
  * @param  BufferLength input data buffer length (number of bytes if pBuffer
  *         type is * uint8_t, number of half-words if pBuffer type is * uint16_t,
  *         number of words if pBuffer type is * uint32_t).
  * @note  By default, the API expects a uint32_t pointer as input buffer parameter.
  *        Input buffer pointers with other types simply need to be cast in uint32_t
  *        and the API will internally adjust its input data processing based on the
  *        handle field hcrc->InputDataFormat.
  * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
  */
uint32_t HAL_CRC_Accumulate(CRC_HandleTypeDef *hcrc, uint32_t pBuffer[], uint32_t BufferLength)
{
  uint32_t index = 0U; /* CRC input data buffer index */
  uint32_t temp = 0U;  /* CRC output (read from hcrc->Instance->DR register) */
  
  /* Process locked */
  __HAL_LOCK(hcrc); 
    
  /* Change CRC peripheral state */  
  hcrc->State = HAL_CRC_STATE_BUSY;
  
  switch (hcrc->InputDataFormat)
  {
    case CRC_INPUTDATA_FORMAT_WORDS:  
      /* Enter Data to the CRC calculator */
      for(index = 0U; index < BufferLength; index++)
      {
        hcrc->Instance->DR = pBuffer[index];
      }
      temp = hcrc->Instance->DR;
      break;
      
    case CRC_INPUTDATA_FORMAT_BYTES: 
      temp = CRC_Handle_8(hcrc, (uint8_t*)pBuffer, BufferLength);
      break;
      
    case CRC_INPUTDATA_FORMAT_HALFWORDS: 
      temp = CRC_Handle_16(hcrc, (uint16_t*)pBuffer, BufferLength);
      break;
      
    default:
      break;          
  }
  
  /* Change CRC peripheral state */    
  hcrc->State = HAL_CRC_STATE_READY; 
  
  /* Process unlocked */
  __HAL_UNLOCK(hcrc);
  
  /* Return the CRC computed value */ 
  return temp;
}


/**                  
  * @brief  Compute the 7, 8, 16 or 32-bit CRC value of an 8, 16 or 32-bit data buffer
  *         starting with hcrc->Instance->INIT as initialization value.
  * @param  hcrc CRC handle
  * @param  pBuffer pointer to the input data buffer, exact input data format is
  *         provided by hcrc->InputDataFormat.  
  * @param  BufferLength input data buffer length (number of bytes if pBuffer
  *         type is * uint8_t, number of half-words if pBuffer type is * uint16_t,
  *         number of words if pBuffer type is * uint32_t).
  * @note  By default, the API expects a uint32_t pointer as input buffer parameter.
  *        Input buffer pointers with other types simply need to be cast in uint32_t
  *        and the API will internally adjust its input data processing based on the
  *        handle field hcrc->InputDataFormat. 
  * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
  */  
uint32_t HAL_CRC_Calculate(CRC_HandleTypeDef *hcrc, uint32_t pBuffer[], uint32_t BufferLength)
{
  uint32_t index = 0U; /* CRC input data buffer index */
  uint32_t temp = 0U;  /* CRC output (read from hcrc->Instance->DR register) */
    
  /* Process locked */
  __HAL_LOCK(hcrc); 
  
  /* Change CRC peripheral state */  
  hcrc->State = HAL_CRC_STATE_BUSY;
  
  /* Reset CRC Calculation Unit (hcrc->Instance->INIT is 
  *  written in hcrc->Instance->DR) */
  __HAL_CRC_DR_RESET(hcrc);
  
  switch (hcrc->InputDataFormat)
  {
    case CRC_INPUTDATA_FORMAT_WORDS:  
      /* Enter 32-bit input data to the CRC calculator */
      for(index = 0U; index < BufferLength; index++)
      {
        hcrc->Instance->DR = pBuffer[index];
      }
      temp = hcrc->Instance->DR;
      break;
      
    case CRC_INPUTDATA_FORMAT_BYTES: 
      /* Specific 8-bit input data handling  */
      temp = CRC_Handle_8(hcrc, (uint8_t*)pBuffer, BufferLength);
      break;
      
    case CRC_INPUTDATA_FORMAT_HALFWORDS: 
      /* Specific 16-bit input data handling  */
      temp = CRC_Handle_16(hcrc, (uint16_t*)pBuffer, BufferLength);
      break;
      
    default:
      break;         
  }

  /* Change CRC peripheral state */    
  hcrc->State = HAL_CRC_STATE_READY; 
  
  /* Process unlocked */
  __HAL_UNLOCK(hcrc);
  
  /* Return the CRC computed value */ 
  return temp;
}
  
/**
  * @}
  */

/** @defgroup CRC_Exported_Functions_Group3 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 CRC handle state.
  * @param  hcrc CRC handle
  * @retval HAL state
  */
HAL_CRC_StateTypeDef HAL_CRC_GetState(CRC_HandleTypeDef *hcrc)
{
  /* Return CRC handle state */
  return hcrc->State;
}

/**
  * @}
  */

/**
  * @}
  */

/** @defgroup CRC_Private_Functions CRC Private Functions
  * @{
  */

/**             
  * @brief  Enter 8-bit input data to the CRC calculator.
  *         Specific data handling to optimize processing time.  
  * @param  hcrc CRC handle
  * @param  pBuffer pointer to the input data buffer
  * @param  BufferLength input data buffer length
  * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
  */
static uint32_t CRC_Handle_8(CRC_HandleTypeDef *hcrc, uint8_t pBuffer[], uint32_t BufferLength)
{
  uint32_t i = 0U; /* input data buffer index */
  
   /* Processing time optimization: 4 bytes are entered in a row with a single word write,
    * last bytes must be carefully fed to the CRC calculator to ensure a correct type
    * handling by the IP */
   for(i = 0U; i < (BufferLength/4U); i++)
   {
      hcrc->Instance->DR = ((uint32_t)pBuffer[4U*i]<<24U) | ((uint32_t)pBuffer[4U*i+1]<<16U) | ((uint32_t)pBuffer[4U*i+2]<<8U) | (uint32_t)pBuffer[4U*i+3];      
   }
   /* last bytes specific handling */
   if ((BufferLength%4U) != 0U)
   {
     if  (BufferLength%4U == 1U)
     {
       *(uint8_t volatile*) (&hcrc->Instance->DR) = pBuffer[4*i];
     }
     if  (BufferLength%4U == 2U)
     {
       *(uint16_t volatile*) (&hcrc->Instance->DR) = ((uint32_t)pBuffer[4*i]<<8) | (uint32_t)pBuffer[4*i+1];
     }
     if  (BufferLength%4U == 3U)
     {
       *(uint16_t volatile*) (&hcrc->Instance->DR) = ((uint32_t)pBuffer[4*i]<<8) | (uint32_t)pBuffer[4*i+1];
       *(uint8_t volatile*) (&hcrc->Instance->DR) = pBuffer[4*i+2];       
     }
   }
  
  /* Return the CRC computed value */ 
  return hcrc->Instance->DR;
}



/**             
  * @brief  Enter 16-bit input data to the CRC calculator.
  *         Specific data handling to optimize processing time.  
  * @param  hcrc CRC handle
  * @param  pBuffer pointer to the input data buffer
  * @param  BufferLength input data buffer length
  * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
  */  
static uint32_t CRC_Handle_16(CRC_HandleTypeDef *hcrc, uint16_t pBuffer[], uint32_t BufferLength)
{
  uint32_t i = 0U;  /* input data buffer index */
  
  /* Processing time optimization: 2 HalfWords are entered in a row with a single word write,
   * in case of odd length, last HalfWord must be carefully fed to the CRC calculator to ensure 
   * a correct type handling by the IP */
  for(i = 0U; i < (BufferLength/2U); i++)
  {
    hcrc->Instance->DR = ((uint32_t)pBuffer[2U*i]<<16U) | (uint32_t)pBuffer[2U*i+1];     
  }
  if ((BufferLength%2U) != 0U)
  {
       *(uint16_t volatile*) (&hcrc->Instance->DR) = pBuffer[2*i]; 
  }
   
  /* Return the CRC computed value */ 
  return hcrc->Instance->DR;
}

/**
  * @}
  */
  
#endif /* HAL_CRC_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

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