stm32f7xx_hal_rng.c

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/* Includes ------------------------------------------------------------------*/
#include "stm32f7xx_hal.h"

#ifdef HAL_RNG_MODULE_ENABLED

/* Private types -------------------------------------------------------------*/
/* Private defines -----------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
#define RNG_TIMEOUT_VALUE     2

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

HAL_StatusTypeDef HAL_RNG_Init(RNG_HandleTypeDef *hrng)
{ 
  /* Check the RNG handle allocation */
  if(hrng == NULL)
  {
    return HAL_ERROR;
  }
  
  __HAL_LOCK(hrng);
  
  if(hrng->State == HAL_RNG_STATE_RESET)
  {  
    /* Allocate lock resource and initialize it */
    hrng->Lock = HAL_UNLOCKED;

    /* Init the low level hardware */
    HAL_RNG_MspInit(hrng);
  }
  
  /* Change RNG peripheral state */
  hrng->State = HAL_RNG_STATE_BUSY;

  /* Enable the RNG Peripheral */
  __HAL_RNG_ENABLE(hrng);

  /* Initialize the RNG state */
  hrng->State = HAL_RNG_STATE_READY;
  
  __HAL_UNLOCK(hrng);
  
  /* Return function status */
  return HAL_OK;
}

HAL_StatusTypeDef HAL_RNG_DeInit(RNG_HandleTypeDef *hrng)
{ 
  /* Check the RNG handle allocation */
  if(hrng == NULL)
  {
    return HAL_ERROR;
  }
  /* Disable the RNG Peripheral */
  CLEAR_BIT(hrng->Instance->CR, RNG_CR_IE | RNG_CR_RNGEN);
  
  /* Clear RNG interrupt status flags */
  CLEAR_BIT(hrng->Instance->SR, RNG_SR_CEIS | RNG_SR_SEIS);
  
  /* DeInit the low level hardware */
  HAL_RNG_MspDeInit(hrng);
  
  /* Update the RNG state */
  hrng->State = HAL_RNG_STATE_RESET; 

  /* Release Lock */
  __HAL_UNLOCK(hrng);
  
  /* Return the function status */
  return HAL_OK;
}

__weak void HAL_RNG_MspInit(RNG_HandleTypeDef *hrng)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hrng);
  
  /* NOTE : This function should not be modified. When the callback is needed,
            function HAL_RNG_MspInit must be implemented in the user file.
   */
}

__weak void HAL_RNG_MspDeInit(RNG_HandleTypeDef *hrng)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hrng);
  
  /* NOTE : This function should not be modified. When the callback is needed,
            function HAL_RNG_MspDeInit must be implemented in the user file.
   */
}

HAL_StatusTypeDef HAL_RNG_GenerateRandomNumber(RNG_HandleTypeDef *hrng, uint32_t *random32bit)
{
  uint32_t tickstart = 0;    
  HAL_StatusTypeDef status = HAL_OK;

  /* Process Locked */
  __HAL_LOCK(hrng); 
  
  /* Check RNG peripheral state */
  if(hrng->State == HAL_RNG_STATE_READY)
  {
    /* Change RNG peripheral state */  
    hrng->State = HAL_RNG_STATE_BUSY;  

    /* Get tick */
    tickstart = HAL_GetTick();
  
    /* Check if data register contains valid random data */
    while(__HAL_RNG_GET_FLAG(hrng, RNG_FLAG_DRDY) == RESET)
    {
      if((HAL_GetTick() - tickstart ) > RNG_TIMEOUT_VALUE)
      {    
        hrng->State = HAL_RNG_STATE_ERROR;

        /* Process Unlocked */
        __HAL_UNLOCK(hrng);
      
        return HAL_TIMEOUT;
      } 
    }
  
    /* Get a 32bit Random number */
    hrng->RandomNumber = hrng->Instance->DR;
    *random32bit = hrng->RandomNumber;
  
    hrng->State = HAL_RNG_STATE_READY;
  }
  else
  {
    status = HAL_ERROR;
  }
  
  /* Process Unlocked */
  __HAL_UNLOCK(hrng);
  
  return status;
}

HAL_StatusTypeDef HAL_RNG_GenerateRandomNumber_IT(RNG_HandleTypeDef *hrng)
{
  HAL_StatusTypeDef status = HAL_OK;
  
  /* Process Locked */
  __HAL_LOCK(hrng);
  
  /* Check RNG peripheral state */
  if(hrng->State == HAL_RNG_STATE_READY)
  {
    /* Change RNG peripheral state */  
    hrng->State = HAL_RNG_STATE_BUSY;  
  
    /* Process Unlocked */
    __HAL_UNLOCK(hrng);
    
    /* Enable the RNG Interrupts: Data Ready, Clock error, Seed error */ 
    __HAL_RNG_ENABLE_IT(hrng);
  }
  else
  {
    /* Process Unlocked */
    __HAL_UNLOCK(hrng);
    
    status = HAL_ERROR;
  }
  
  return status;
}

void HAL_RNG_IRQHandler(RNG_HandleTypeDef *hrng)
{
  /* RNG clock error interrupt occurred */
  if((__HAL_RNG_GET_IT(hrng, RNG_IT_CEI) != RESET) ||  (__HAL_RNG_GET_IT(hrng, RNG_IT_SEI) != RESET))
  { 
    /* Change RNG peripheral state */
    hrng->State = HAL_RNG_STATE_ERROR;
  
    HAL_RNG_ErrorCallback(hrng);
    
    /* Clear the clock error flag */
    __HAL_RNG_CLEAR_IT(hrng, RNG_IT_CEI|RNG_IT_SEI);
    
  }
  
  /* Check RNG data ready interrupt occurred */    
  if(__HAL_RNG_GET_IT(hrng, RNG_IT_DRDY) != RESET)
  {
    /* Generate random number once, so disable the IT */
    __HAL_RNG_DISABLE_IT(hrng);
    
    /* Get the 32bit Random number (DRDY flag automatically cleared) */ 
    hrng->RandomNumber = hrng->Instance->DR;
    
    if(hrng->State != HAL_RNG_STATE_ERROR)
    {
      /* Change RNG peripheral state */
      hrng->State = HAL_RNG_STATE_READY; 
      
      /* Data Ready callback */ 
      HAL_RNG_ReadyDataCallback(hrng, hrng->RandomNumber);
    } 
  }
} 

uint32_t HAL_RNG_GetRandomNumber(RNG_HandleTypeDef *hrng)
{
  if(HAL_RNG_GenerateRandomNumber(hrng, &(hrng->RandomNumber)) == HAL_OK)
  {
    return hrng->RandomNumber; 
  }
  else
  {
    return 0;
  }
}

uint32_t HAL_RNG_GetRandomNumber_IT(RNG_HandleTypeDef *hrng)
{
  uint32_t random32bit = 0;
  
  /* Process locked */
  __HAL_LOCK(hrng);
  
  /* Change RNG peripheral state */  
  hrng->State = HAL_RNG_STATE_BUSY;  
  
  /* Get a 32bit Random number */ 
  random32bit = hrng->Instance->DR;
  
  /* Enable the RNG Interrupts: Data Ready, Clock error, Seed error */ 
  __HAL_RNG_ENABLE_IT(hrng); 
  
  /* Return the 32 bit random number */   
  return random32bit;
}

uint32_t HAL_RNG_ReadLastRandomNumber(RNG_HandleTypeDef *hrng)
{
  return(hrng->RandomNumber);
}

__weak void HAL_RNG_ReadyDataCallback(RNG_HandleTypeDef *hrng, uint32_t random32bit)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hrng);
  
  /* NOTE : This function should not be modified. When the callback is needed,
            function HAL_RNG_ReadyDataCallback must be implemented in the user file.
   */
}

__weak void HAL_RNG_ErrorCallback(RNG_HandleTypeDef *hrng)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(hrng);
  
  /* NOTE : This function should not be modified. When the callback is needed,
            function HAL_RNG_ErrorCallback must be implemented in the user file.
   */
}
HAL_RNG_StateTypeDef HAL_RNG_GetState(RNG_HandleTypeDef *hrng)
{
  return hrng->State;
}

#endif /* HAL_RNG_MODULE_ENABLED */

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