Blocking mode Polling

Functions
HAL_StatusTypeDef	HAL_SMBUS_IsDeviceReady (SMBUS_HandleTypeDef *hsmbus, uint16_t DevAddress, uint32_t Trials, uint32_t Timeout)
	Check if target device is ready for communication. More...

Detailed Description

Function Documentation

HAL_SMBUS_IsDeviceReady()

HAL_StatusTypeDef HAL_SMBUS_IsDeviceReady	(	SMBUS_HandleTypeDef *	hsmbus,
		uint16_t	DevAddress,
		uint32_t	Trials,
		uint32_t	Timeout
	)

Check if target device is ready for communication.

Parameters

hsmbus	Pointer to a SMBUS_HandleTypeDef structure that contains the configuration information for the specified SMBUS.
DevAddress	Target device address: The device 7 bits address value in datasheet must be shifted to the left before calling the interface
Trials	Number of trials
Timeout	Timeout duration

Return values

HAL

status

Definition at line 1420 of file stm32l4xx_hal_smbus.c.

{
  uint32_t tickstart;

  __IO uint32_t SMBUS_Trials = 0UL;

  FlagStatus tmp1;
  FlagStatus tmp2;

  if (hsmbus->State == HAL_SMBUS_STATE_READY)
  {
    if (__HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_BUSY) != RESET)
    {
      return HAL_BUSY;
    }

    /* Process Locked */
    __HAL_LOCK(hsmbus);

    hsmbus->State = HAL_SMBUS_STATE_BUSY;
    hsmbus->ErrorCode = HAL_SMBUS_ERROR_NONE;

    do
    {
      /* Generate Start */
      hsmbus->Instance->CR2 = SMBUS_GENERATE_START(hsmbus->Init.AddressingMode, DevAddress);

      /* No need to Check TC flag, with AUTOEND mode the stop is automatically generated */
      /* Wait until STOPF flag is set or a NACK flag is set*/
      tickstart = HAL_GetTick();

      tmp1 = __HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_STOPF);
      tmp2 = __HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_AF);

      while ((tmp1 == RESET) && (tmp2 == RESET))
      {
        if (Timeout != HAL_MAX_DELAY)
        {
          if (((HAL_GetTick() - tickstart) > Timeout) || (Timeout == 0UL))
          {
            /* Device is ready */
            hsmbus->State = HAL_SMBUS_STATE_READY;

            /* Update SMBUS error code */
            hsmbus->ErrorCode |= HAL_SMBUS_ERROR_HALTIMEOUT;

            /* Process Unlocked */
            __HAL_UNLOCK(hsmbus);
            return HAL_ERROR;
          }
        }

        tmp1 = __HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_STOPF);
        tmp2 = __HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_AF);
      }

      /* Check if the NACKF flag has not been set */
      if (__HAL_SMBUS_GET_FLAG(hsmbus, SMBUS_FLAG_AF) == RESET)
      {
        /* Wait until STOPF flag is reset */
        if (SMBUS_WaitOnFlagUntilTimeout(hsmbus, SMBUS_FLAG_STOPF, RESET, Timeout) != HAL_OK)
        {
          return HAL_ERROR;
        }

        /* Clear STOP Flag */
        __HAL_SMBUS_CLEAR_FLAG(hsmbus, SMBUS_FLAG_STOPF);

        /* Device is ready */
        hsmbus->State = HAL_SMBUS_STATE_READY;

        /* Process Unlocked */
        __HAL_UNLOCK(hsmbus);

        return HAL_OK;
      }
      else
      {
        /* Wait until STOPF flag is reset */
        if (SMBUS_WaitOnFlagUntilTimeout(hsmbus, SMBUS_FLAG_STOPF, RESET, Timeout) != HAL_OK)
        {
          return HAL_ERROR;
        }

        /* Clear NACK Flag */
        __HAL_SMBUS_CLEAR_FLAG(hsmbus, SMBUS_FLAG_AF);

        /* Clear STOP Flag, auto generated with autoend*/
        __HAL_SMBUS_CLEAR_FLAG(hsmbus, SMBUS_FLAG_STOPF);
      }

      /* Check if the maximum allowed number of trials has been reached */
      if (SMBUS_Trials == Trials)
      {
        /* Generate Stop */
        hsmbus->Instance->CR2 |= I2C_CR2_STOP;

        /* Wait until STOPF flag is reset */
        if (SMBUS_WaitOnFlagUntilTimeout(hsmbus, SMBUS_FLAG_STOPF, RESET, Timeout) != HAL_OK)
        {
          return HAL_ERROR;
        }

        /* Clear STOP Flag */
        __HAL_SMBUS_CLEAR_FLAG(hsmbus, SMBUS_FLAG_STOPF);
      }

      /* Increment Trials */
      SMBUS_Trials++;
    }
    while (SMBUS_Trials < Trials);

    hsmbus->State = HAL_SMBUS_STATE_READY;

    /* Update SMBUS error code */
    hsmbus->ErrorCode |= HAL_SMBUS_ERROR_HALTIMEOUT;

    /* Process Unlocked */
    __HAL_UNLOCK(hsmbus);

    return HAL_ERROR;
  }
  else
  {
    return HAL_BUSY;
  }
}