/**
  * @brief I2C MSP Initialization
  *        This function configures the hardware resources used in this example:
  *           - Peripheral's clock enable
  *           - Peripheral's GPIO Configuration
  *           - DMA configuration for transmission request by peripheral
  *           - NVIC configuration for DMA interrupt request enable
  * @param hi2c: I2C handle pointer
  * @retval None
  */
void HAL_I2C_MspInit(I2C_HandleTypeDef *hi2c)
{
  static DMA_HandleTypeDef hdma_tx;
  static DMA_HandleTypeDef hdma_rx;

  GPIO_InitTypeDef  GPIO_InitStruct;

  /*##-1- Enable peripherals and GPIO Clocks #################################*/
  /* Enable GPIO TX/RX clock */
  I2Cx_SCL_GPIO_CLK_ENABLE();
  I2Cx_SDA_GPIO_CLK_ENABLE();
  /* Enable I2Cx clock */
  I2Cx_CLK_ENABLE();
  /* Enable DMAx clock */
  I2Cx_DMA_CLK_ENABLE();

  /*##-2- Configure peripheral GPIO ##########################################*/
  /* I2C TX GPIO pin configuration  */
  GPIO_InitStruct.Pin       = I2Cx_SCL_PIN;
  GPIO_InitStruct.Mode      = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull      = GPIO_PULLUP;
  GPIO_InitStruct.Speed     = GPIO_SPEED_HIGH;
  GPIO_InitStruct.Alternate = I2Cx_SCL_AF;

  HAL_GPIO_Init(I2Cx_SCL_GPIO_PORT, &GPIO_InitStruct);

  /* I2C RX GPIO pin configuration  */
  GPIO_InitStruct.Pin = I2Cx_SDA_PIN;
  GPIO_InitStruct.Alternate = I2Cx_SDA_AF;

  HAL_GPIO_Init(I2Cx_SDA_GPIO_PORT, &GPIO_InitStruct);

  /*##-3- Configure the DMA ##################################################*/
  /* Configure the DMA handler for Transmission process */
  hdma_tx.Instance                 = I2Cx_DMA_CHANNEL_TX;

  hdma_tx.Init.Direction           = DMA_MEMORY_TO_PERIPH;
  hdma_tx.Init.PeriphInc           = DMA_PINC_DISABLE;
  hdma_tx.Init.MemInc              = DMA_MINC_ENABLE;
  hdma_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_tx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
  hdma_tx.Init.Mode                = DMA_NORMAL;
  hdma_tx.Init.Priority            = DMA_PRIORITY_LOW;

  HAL_DMA_Init(&hdma_tx);

  /* Associate the initialized DMA handle to the the I2C handle */
  __HAL_LINKDMA(hi2c, hdmatx, hdma_tx);

  /* Configure the DMA handler for Transmission process */
  hdma_rx.Instance                 = I2Cx_DMA_CHANNEL_RX;

  hdma_rx.Init.Direction           = DMA_PERIPH_TO_MEMORY;
  hdma_rx.Init.PeriphInc           = DMA_PINC_DISABLE;
  hdma_rx.Init.MemInc              = DMA_MINC_ENABLE;
  hdma_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_rx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
  hdma_rx.Init.Mode                = DMA_NORMAL;
  hdma_rx.Init.Priority            = DMA_PRIORITY_HIGH;

  HAL_DMA_Init(&hdma_rx);

  /* Associate the initialized DMA handle to the the I2C handle */
  __HAL_LINKDMA(hi2c, hdmarx, hdma_rx);

  /*##-4- Configure the NVIC for DMA #########################################*/
  /* NVIC configuration for DMA transfer complete interrupt (I2C1_TX) */
  HAL_NVIC_SetPriority(I2Cx_DMA_TX_IRQn, 0, 1);
  HAL_NVIC_EnableIRQ(I2Cx_DMA_TX_IRQn);

  /* NVIC configuration for DMA transfer complete interrupt (I2C1_RX) */
  HAL_NVIC_SetPriority(I2Cx_DMA_RX_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(I2Cx_DMA_RX_IRQn);
}
/**
  * @brief I2C MSP Initialization 
  *        This function configures the hardware resources used in this example: 
  *           - Peripheral's clock enable
  *           - Peripheral's GPIO Configuration  
  *           - DMA configuration for transmission request by peripheral 
  *           - NVIC configuration for DMA interrupt request enable
  * @param hi2c: I2C handle pointer
  * @retval None
  */
void HAL_I2C_MspInit(I2C_HandleTypeDef *hi2c)
{
  GPIO_InitTypeDef  GPIO_InitStruct;
  static DMA_HandleTypeDef hdma_tx;
  static DMA_HandleTypeDef hdma_rx;
  RCC_PeriphCLKInitTypeDef  RCC_PeriphCLKInitStruct;
  
  /*##-1- Configure the I2C clock source. The clock is derived from the SYSCLK #*/
  RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_I2Cx;
  RCC_PeriphCLKInitStruct.I2c1ClockSelection = RCC_I2CxCLKSOURCE_SYSCLK;
  HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct);

  /*##-2- Enable peripherals and GPIO Clocks #################################*/
  /* Enable GPIO TX/RX clock */
  I2Cx_SCL_GPIO_CLK_ENABLE();
  I2Cx_SDA_GPIO_CLK_ENABLE();
  /* Enable I2Cx clock */
  I2Cx_CLK_ENABLE(); 

  /* Enable DMAx clock */
  I2Cx_DMA_CLK_ENABLE();   
  
  /*##-3- Configure peripheral GPIO ##########################################*/  
  /* I2C TX GPIO pin configuration  */
  GPIO_InitStruct.Pin       = I2Cx_SCL_PIN;
  GPIO_InitStruct.Mode      = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull      = GPIO_PULLUP;
  GPIO_InitStruct.Speed     = GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.Alternate = I2Cx_SCL_SDA_AF;
  HAL_GPIO_Init(I2Cx_SCL_GPIO_PORT, &GPIO_InitStruct);
    
  /* I2C RX GPIO pin configuration  */
  GPIO_InitStruct.Pin       = I2Cx_SDA_PIN;
  GPIO_InitStruct.Alternate = I2Cx_SCL_SDA_AF;
  HAL_GPIO_Init(I2Cx_SDA_GPIO_PORT, &GPIO_InitStruct);
    
  /*##-4- Configure the DMA Channels #########################################*/
  /* Configure the DMA handler for Transmission process */
  hdma_tx.Instance                 = I2Cx_DMA_INSTANCE_TX;
  hdma_tx.Init.Request             = I2Cx_DMA_REQUEST_TX;
  hdma_tx.Init.Direction           = DMA_MEMORY_TO_PERIPH;
  hdma_tx.Init.PeriphInc           = DMA_PINC_DISABLE;
  hdma_tx.Init.MemInc              = DMA_MINC_ENABLE;
  hdma_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_tx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
  hdma_tx.Init.Mode                = DMA_NORMAL;
  hdma_tx.Init.Priority            = DMA_PRIORITY_LOW;

  HAL_DMA_Init(&hdma_tx);   
  
  /* Associate the initialized DMA handle to the the I2C handle */
  __HAL_LINKDMA(hi2c, hdmatx, hdma_tx);
    
  /* Configure the DMA handler for Transmission process */
  hdma_rx.Instance                 = I2Cx_DMA_INSTANCE_RX;
  hdma_rx.Init.Request             = I2Cx_DMA_REQUEST_RX;
  hdma_rx.Init.Direction           = DMA_PERIPH_TO_MEMORY;
  hdma_rx.Init.PeriphInc           = DMA_PINC_DISABLE;
  hdma_rx.Init.MemInc              = DMA_MINC_ENABLE;
  hdma_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_rx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
  hdma_rx.Init.Mode                = DMA_NORMAL;
  hdma_rx.Init.Priority            = DMA_PRIORITY_HIGH;

  HAL_DMA_Init(&hdma_rx);
    
  /* Associate the initialized DMA handle to the the I2C handle */
  __HAL_LINKDMA(hi2c, hdmarx, hdma_rx);
    
  /*##-5- Configure the NVIC for DMA #########################################*/
  /* NVIC configuration for DMA transfer complete interrupt (I2Cx_TX) */
  HAL_NVIC_SetPriority(I2Cx_DMA_TX_IRQn, 0, 1);
  HAL_NVIC_EnableIRQ(I2Cx_DMA_TX_IRQn);
    
  /* NVIC configuration for DMA transfer complete interrupt (I2Cx_RX) */
  HAL_NVIC_SetPriority(I2Cx_DMA_RX_IRQn, 0, 0);   
  HAL_NVIC_EnableIRQ(I2Cx_DMA_RX_IRQn);
}