/**
  ******************************************************************************
  * @file    stm32f429i_discovery_i2c_ee.c
  * @author  MCD Application Team
  * @version V1.0.1
  * @date    28-October-2013
  * @brief   This file provides a set of functions needed to manage an I2C M24LR64 
  *          EEPROM memory.
  *          
  *          =================================================================== 
  *          Notes:
  *           - This driver is intended for STM32F4xx families devices only. 
  *           - The I2C EEPROM memory (M24LR64) is available on separate daughter 
  *             board ANT7-M24LR-A, which is not provided with the STM32F429I 
  *             DISCOVERY board.
  *             To use this driver you have to connect the ANT7-M24LR-A to CN3 
  *             connector of STM32F429I DISCOVERY board.      
  *          ===================================================================
  *              
  *          It implements a high level communication layer for read and write 
  *          from/to this memory. The needed STM32F4xx hardware resources (I2C and 
  *          GPIO) are defined in stm32f429i_discovery.h file, and the initialization is 
  *          performed in sEE_LowLevel_Init() function declared in stm32f429i_discovery.c 
  *          file.
  *          You can easily tailor this driver to any other development board, 
  *          by just adapting the defines for hardware resources and 
  *          sEE_LowLevel_Init() function. 
  *        
  *          @note In this driver, basic read and write functions (sEE_ReadBuffer() 
  *                and sEE_WritePage()) use Polling mode to perform the data transfer 
  *                to/from EEPROM memory.
  *             
  *     +-----------------------------------------------------------------+
  *     |               Pin assignment for M24LR64 EEPROM                 |
  *     +---------------------------------------+-----------+-------------+
  *     |  STM32F4xx I2C Pins                   |   sEE     |   Pin       |
  *     +---------------------------------------+-----------+-------------+
  *     | .                                     |   E0(GND) |    1  (0V)  |
  *     | .                                     |   AC0     |    2        |
  *     | .                                     |   AC1     |    3        |
  *     | .                                     |   VSS     |    4  (0V)  |
  *     | sEE_I2C_SDA_PIN/ SDA                  |   SDA     |    5        |
  *     | sEE_I2C_SCL_PIN/ SCL                  |   SCL     |    6        |
  *     | .                                     |   E1(GND) |    7  (0V)  |
  *     | .                                     |   VDD     |    8 (3.3V) |
  *     +---------------------------------------+-----------+-------------+
  *
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32f429i_discovery_i2c_ee.h"

/** @addtogroup Utilities
  * @{
  */
  
/** @addtogroup STM32F4_DISCOVERY
  * @{
  */ 

/** @addtogroup STM32F429I_DISCOVERY
  * @{
  */
  
/** @addtogroup STM32F429I_DISCOVERY_I2C_EE
  * @brief      This file includes the I2C EEPROM driver of STM32F429I Discovery Kit.
  * @{
  */ 

/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Types
  * @{
  */ 
/**
  * @}
  */ 


/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Defines
  * @{
  */  
/**
  * @}
  */ 


/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Macros
  * @{
  */
/**
  * @}
  */ 
  

/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Variables
  * @{
  */
__IO uint16_t  sEEAddress = 0;   
__IO uint32_t  sEETimeout = sEE_LONG_TIMEOUT;   
__IO uint16_t* sEEDataReadPointer;   
__IO uint8_t*  sEEDataWritePointer;  
__IO uint8_t   sEEDataNum;
/**
  * @}
  */ 


/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Function_Prototypes
  * @{
  */ 
/**
  * @}
  */ 


/** @defgroup STM32F429I_DISCOVERY_I2C_EE_Private_Functions
  * @{
  */ 

/**
  * @brief  DeInitializes peripherals used by the I2C EEPROM driver.
  * @param  None
  * @retval None
  */
void sEE_DeInit(void)
{
  sEE_LowLevel_DeInit(); 
}

/**
  * @brief  Initializes peripherals used by the I2C EEPROM driver.
  * @param  None
  * @retval None
  */
void sEE_Init(void)
{ 
  I2C_InitTypeDef  I2C_InitStructure;
  
  sEE_LowLevel_Init();

  /* If the I2C peripheral is already enabled, don't reconfigure it */
  if ((sEE_I2C->CR1 & I2C_CR1_PE) == 0)
  {     
    /*!< I2C configuration */
    /* sEE_I2C configuration */
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0x00;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStructure.I2C_ClockSpeed = I2C_SPEED;
    
    /* Apply sEE_I2C configuration after enabling it */
    I2C_Init(sEE_I2C, &I2C_InitStructure);
  
    /* sEE_I2C Peripheral Enable */
    I2C_Cmd(sEE_I2C, ENABLE);
  }  

  /* Enable the sEE_I2C peripheral DMA requests */
  I2C_DMACmd(sEE_I2C, ENABLE);  

  /*!< Select the EEPROM address */
  sEEAddress = sEE_HW_ADDRESS;   
}

/**
  * @brief  Reads a block of data from the EEPROM.
  * @param  pBuffer : pointer to the buffer that receives the data read from 
  *         the EEPROM.
  * @param  ReadAddr : EEPROM's internal address to start reading from.
  * @param  NumByteToRead : pointer to the variable holding number of bytes to 
  *         be read from the EEPROM.
  * 
  *        @note The variable pointed by NumByteToRead is reset to 0 when all the 
  *              data are read from the EEPROM. Application should monitor this 
  *              variable in order know when the transfer is complete.
  * 
  * @note When number of data to be read is higher than 1, this function just 
  *       configures the communication and enable the DMA channel to transfer data.
  *       Meanwhile, the user application may perform other tasks.
  *       When number of data to be read is 1, then the DMA is not used. The byte
  *       is read in polling mode.
  * 
  * @retval sEE_OK (0) if operation is correctly performed, else return value 
  *         different from sEE_OK (0) or the timeout user callback.
  */
uint32_t sEE_ReadBuffer(uint8_t* pBuffer, uint16_t ReadAddr, uint16_t* NumByteToRead)
{  
  /* Set the pointer to the Number of data to be read. This pointer will be used 
      by the DMA Transfer Completer interrupt Handler in order to reset the 
      variable to 0. User should check on this variable in order to know if the 
      DMA transfer has been complete or not. */
  sEEDataReadPointer = NumByteToRead;
  
  /*!< While the bus is busy */
  sEETimeout = sEE_LONG_TIMEOUT;
  while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_BUSY))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send START condition */
  I2C_GenerateSTART(sEE_I2C, ENABLE);
  
  /*!< Test on EV5 and clear it (cleared by reading SR1 then writing to DR) */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_MODE_SELECT))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send EEPROM address for write */
  I2C_Send7bitAddress(sEE_I2C, sEEAddress, I2C_Direction_Transmitter);

  /*!< Test on EV6 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  } 

  /*!< Send the EEPROM's internal address to read from: MSB of the address first */
  I2C_SendData(sEE_I2C, (uint8_t)((ReadAddr & 0xFF00) >> 8));    

  /*!< Test on EV8 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_BYTE_TRANSMITTING))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }

  /*!< Send the EEPROM's internal address to read from: LSB of the address */
  I2C_SendData(sEE_I2C, (uint8_t)(ReadAddr & 0x00FF));    

  /*!< Test on EV8 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_BTF) == RESET)
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send STRAT condition a second time */  
  I2C_GenerateSTART(sEE_I2C, ENABLE);
  
  /*!< Test on EV5 and clear it (cleared by reading SR1 then writing to DR) */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_MODE_SELECT))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  } 
  
  /*!< Send EEPROM address for read */
  I2C_Send7bitAddress(sEE_I2C, sEEAddress, I2C_Direction_Receiver);  
  
  /* If number of data to be read is 1, then DMA couldn't be used */
  /* One Byte Master Reception procedure (POLLING) ---------------------------*/
  if ((uint16_t)(*NumByteToRead) < 2)
  {
    /* Wait on ADDR flag to be set (ADDR is still not cleared at this level */
    sEETimeout = sEE_FLAG_TIMEOUT;
    while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_ADDR) == RESET)
    {
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }     
    
    /*!< Disable Acknowledgement */
    I2C_AcknowledgeConfig(sEE_I2C, DISABLE);   
    
    /* Clear ADDR register by reading SR1 then SR2 register (SR1 has already been read) */
    (void)sEE_I2C->SR2;
    
    /*!< Send STOP Condition */
    I2C_GenerateSTOP(sEE_I2C, ENABLE);
    
    /* Wait for the byte to be received */
    sEETimeout = sEE_FLAG_TIMEOUT;
    while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_RXNE) == RESET)
    {
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }
    
    /*!< Read the byte received from the EEPROM */
    *pBuffer = I2C_ReceiveData(sEE_I2C);
    
    /*!< Decrement the read bytes counter */
    (uint16_t)(*NumByteToRead)--;        
    
    /* Wait to make sure that STOP control bit has been cleared */
    sEETimeout = sEE_FLAG_TIMEOUT;
    while(sEE_I2C->CR1 & I2C_CR1_STOP)
    {
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }  
    
    /*!< Re-Enable Acknowledgement to be ready for another reception */
    I2C_AcknowledgeConfig(sEE_I2C, ENABLE);    
  }
  else/* More than one Byte Master Reception procedure (DMA) -----------------*/
  {
    /*!< Test on EV6 and clear it */
    sEETimeout = sEE_FLAG_TIMEOUT;
    while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED))
    {
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }  
    
    /* Configure the DMA Rx Channel with the buffer address and the buffer size */
    sEE_LowLevel_DMAConfig((uint32_t)pBuffer, (uint16_t)(*NumByteToRead), sEE_DIRECTION_RX);
    
    /* Inform the DMA that the next End Of Transfer Signal will be the last one */
    I2C_DMALastTransferCmd(sEE_I2C, ENABLE); 
    
    /* Enable the DMA Rx Stream */
    DMA_Cmd(sEE_I2C_DMA_STREAM_RX, ENABLE);    
  }
  
  /* If all operations OK, return sEE_OK (0) */
  return sEE_OK;
}

/**
  * @brief  Writes more than one byte to the EEPROM with a single WRITE cycle.
  *
  * @note   The number of bytes (combined to write start address) must not 
  *         cross the EEPROM page boundary. This function can only write into
  *         the boundaries of an EEPROM page.
  *         This function doesn't check on boundaries condition (in this driver 
  *         the function sEE_WriteBuffer() which calls sEE_WritePage() is 
  *         responsible of checking on Page boundaries).
  * 
  * @param  pBuffer : pointer to the buffer containing the data to be written to 
  *         the EEPROM.
  * @param  WriteAddr : EEPROM's internal address to write to.
  * @param  NumByteToWrite : pointer to the variable holding number of bytes to 
  *         be written into the EEPROM. 
  * 
  *        @note The variable pointed by NumByteToWrite is reset to 0 when all the 
  *              data are written to the EEPROM. Application should monitor this 
  *              variable in order know when the transfer is complete.
  * 
  * @note This function just configure the communication and enable the DMA 
  *       channel to transfer data. Meanwhile, the user application may perform 
  *       other tasks in parallel.
  * 
  * @retval sEE_OK (0) if operation is correctly performed, else return value 
  *         different from sEE_OK (0) or the timeout user callback.
  */
uint32_t sEE_WritePage(uint8_t* pBuffer, uint16_t WriteAddr, uint8_t* NumByteToWrite)
{ 
  /* Set the pointer to the Number of data to be written. This pointer will be used 
      by the DMA Transfer Completer interrupt Handler in order to reset the 
      variable to 0. User should check on this variable in order to know if the 
      DMA transfer has been complete or not. */
  sEEDataWritePointer = NumByteToWrite;  
  
  /*!< While the bus is busy */
  sEETimeout = sEE_LONG_TIMEOUT;
  while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_BUSY))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send START condition */
  I2C_GenerateSTART(sEE_I2C, ENABLE);
  
  /*!< Test on EV5 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_MODE_SELECT))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send EEPROM address for write */
  sEETimeout = sEE_FLAG_TIMEOUT;
  I2C_Send7bitAddress(sEE_I2C, sEEAddress, I2C_Direction_Transmitter);

  /*!< Test on EV6 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }
  
  /*!< Send the EEPROM's internal address to write to : MSB of the address first */
  I2C_SendData(sEE_I2C, (uint8_t)((WriteAddr & 0xFF00) >> 8));

  /*!< Test on EV8 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT;  
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_BYTE_TRANSMITTING))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }  
  
  /*!< Send the EEPROM's internal address to write to : LSB of the address */
  I2C_SendData(sEE_I2C, (uint8_t)(WriteAddr & 0x00FF));
  
  /*!< Test on EV8 and clear it */
  sEETimeout = sEE_FLAG_TIMEOUT; 
  while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_BYTE_TRANSMITTING))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }  
  
  /* Configure the DMA Tx Channel with the buffer address and the buffer size */
  sEE_LowLevel_DMAConfig((uint32_t)pBuffer, (uint8_t)(*NumByteToWrite), sEE_DIRECTION_TX);
  
  /* Enable the DMA Tx Stream */
  DMA_Cmd(sEE_I2C_DMA_STREAM_TX, ENABLE);
  
  /* If all operations OK, return sEE_OK (0) */
  return sEE_OK;
}

/**
  * @brief  Writes buffer of data to the I2C EEPROM.
  * @param  pBuffer : pointer to the buffer  containing the data to be written 
  *         to the EEPROM.
  * @param  WriteAddr : EEPROM's internal address to write to.
  * @param  NumByteToWrite : number of bytes to write to the EEPROM.
  * @retval None
  */
void sEE_WriteBuffer(uint8_t* pBuffer, uint16_t WriteAddr, uint16_t NumByteToWrite)
{
  uint16_t NumOfPage = 0, NumOfSingle = 0, count = 0;
  uint16_t Addr = 0;

  Addr = WriteAddr % sEE_PAGESIZE;
  count = sEE_PAGESIZE - Addr;
  NumOfPage =  NumByteToWrite / sEE_PAGESIZE;
  NumOfSingle = NumByteToWrite % sEE_PAGESIZE;
 
  /*!< If WriteAddr is sEE_PAGESIZE aligned  */
  if(Addr == 0) 
  {
    /*!< If NumByteToWrite < sEE_PAGESIZE */
    if(NumOfPage == 0) 
    {
      /* Store the number of data to be written */
      sEEDataNum = NumOfSingle;
      /* Start writing data */
      sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
      /* Wait transfer through DMA to be complete */
      sEETimeout = sEE_LONG_TIMEOUT;
      while (sEEDataNum > 0)
      {
        if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
      }
      sEE_WaitEepromStandbyState();
    }
    /*!< If NumByteToWrite > sEE_PAGESIZE */
    else  
    {
      while(NumOfPage--)
      {
        /* Store the number of data to be written */
        sEEDataNum = sEE_PAGESIZE;        
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum)); 
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }      
        sEE_WaitEepromStandbyState();
        WriteAddr +=  sEE_PAGESIZE;
        pBuffer += sEE_PAGESIZE;
      }

      if(NumOfSingle!=0)
      {
        /* Store the number of data to be written */
        sEEDataNum = NumOfSingle;          
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }    
        sEE_WaitEepromStandbyState();
      }
    }
  }
  /*!< If WriteAddr is not sEE_PAGESIZE aligned  */
  else 
  {
    /*!< If NumByteToWrite < sEE_PAGESIZE */
    if(NumOfPage== 0) 
    {
      /*!< If the number of data to be written is more than the remaining space 
      in the current page: */
      if (NumByteToWrite > count)
      {
        /* Store the number of data to be written */
        sEEDataNum = count;        
        /*!< Write the data contained in same page */
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }          
        sEE_WaitEepromStandbyState();      
        
        /* Store the number of data to be written */
        sEEDataNum = (NumByteToWrite - count);          
        /*!< Write the remaining data in the following page */
        sEE_WritePage((uint8_t*)(pBuffer + count), (WriteAddr + count), (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }     
        sEE_WaitEepromStandbyState();        
      }      
      else      
      {
        /* Store the number of data to be written */
        sEEDataNum = NumOfSingle;         
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }          
        sEE_WaitEepromStandbyState();        
      }     
    }
    /*!< If NumByteToWrite > sEE_PAGESIZE */
    else
    {
      NumByteToWrite -= count;
      NumOfPage =  NumByteToWrite / sEE_PAGESIZE;
      NumOfSingle = NumByteToWrite % sEE_PAGESIZE;
      
      if(count != 0)
      {  
        /* Store the number of data to be written */
        sEEDataNum = count;         
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }     
        sEE_WaitEepromStandbyState();
        WriteAddr += count;
        pBuffer += count;
      } 
      
      while(NumOfPage--)
      {
        /* Store the number of data to be written */
        sEEDataNum = sEE_PAGESIZE;          
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum));
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }        
        sEE_WaitEepromStandbyState();
        WriteAddr +=  sEE_PAGESIZE;
        pBuffer += sEE_PAGESIZE;  
      }
      if(NumOfSingle != 0)
      {
        /* Store the number of data to be written */
        sEEDataNum = NumOfSingle;           
        sEE_WritePage(pBuffer, WriteAddr, (uint8_t*)(&sEEDataNum)); 
        /* Wait transfer through DMA to be complete */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (sEEDataNum > 0)
        {
          if((sEETimeout--) == 0) {sEE_TIMEOUT_UserCallback(); return;};
        }         
        sEE_WaitEepromStandbyState();
      }
    }
  }  
}

/**
  * @brief  Wait for EEPROM Standby state.
  * 
  * @note  This function allows to wait and check that EEPROM has finished the 
  *        last operation. It is mostly used after Write operation: after receiving
  *        the buffer to be written, the EEPROM may need additional time to actually
  *        perform the write operation. During this time, it doesn't answer to
  *        I2C packets addressed to it. Once the write operation is complete
  *        the EEPROM responds to its address.
  * 
  * @param  None
  * @retval sEE_OK (0) if operation is correctly performed, else return value 
  *         different from sEE_OK (0) or the timeout user callback.
  */
uint32_t sEE_WaitEepromStandbyState(void)      
{
  __IO uint16_t tmpSR1 = 0;
  __IO uint32_t sEETrials = 0;

  /*!< While the bus is busy */
  sEETimeout = sEE_LONG_TIMEOUT;
  while(I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_BUSY))
  {
    if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
  }

  /* Keep looping till the slave acknowledge his address or maximum number 
     of trials is reached (this number is defined by sEE_MAX_TRIALS_NUMBER define
     in stm32f429i_discovery_i2c_ee.h file) */
  while (1)
  {
    /*!< Send START condition */
    I2C_GenerateSTART(sEE_I2C, ENABLE);

    /*!< Test on EV5 and clear it */
    sEETimeout = sEE_FLAG_TIMEOUT;
    while(!I2C_CheckEvent(sEE_I2C, I2C_EVENT_MASTER_MODE_SELECT))
    {
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }    

    /*!< Send EEPROM address for write */
    I2C_Send7bitAddress(sEE_I2C, sEEAddress, I2C_Direction_Transmitter);
    
    /* Wait for ADDR flag to be set (Slave acknowledged his address) */
    sEETimeout = sEE_LONG_TIMEOUT;
    do
    {     
      /* Get the current value of the SR1 register */
      tmpSR1 = sEE_I2C->SR1;
      
      /* Update the timeout value and exit if it reach 0 */
      if((sEETimeout--) == 0) return sEE_TIMEOUT_UserCallback();
    }
    /* Keep looping till the Address is acknowledged or the AF flag is 
       set (address not acknowledged at time) */
    while((tmpSR1 & (I2C_SR1_ADDR | I2C_SR1_AF)) == 0);
     
    /* Check if the ADDR flag has been set */
    if (tmpSR1 & I2C_SR1_ADDR)
    {
      /* Clear ADDR Flag by reading SR1 then SR2 registers (SR1 have already 
         been read) */
      (void)sEE_I2C->SR2;
      
      /*!< STOP condition */    
      I2C_GenerateSTOP(sEE_I2C, ENABLE);
        
      /* Exit the function */
      return sEE_OK;
    }
    else
    {
      /*!< Clear AF flag */
      I2C_ClearFlag(sEE_I2C, I2C_FLAG_AF);                  
    }
    
    /* Check if the maximum allowed number of trials has bee reached */
    if (sEETrials++ == sEE_MAX_TRIALS_NUMBER)
    {
      /* If the maximum number of trials has been reached, exit the function */
      return sEE_TIMEOUT_UserCallback();
    }
  }
}

/**
  * @brief  This function handles the DMA Tx Channel interrupt Handler.
  * @param  None
  * @retval None
  */
void sEE_I2C_DMA_TX_IRQHandler(void)
{
  /* Check if the DMA transfer is complete */
  if(DMA_GetFlagStatus(sEE_I2C_DMA_STREAM_TX, sEE_TX_DMA_FLAG_TCIF) != RESET)
  {  
    /* Disable the DMA Tx Stream and Clear TC flag */  
    DMA_Cmd(sEE_I2C_DMA_STREAM_TX, DISABLE);
    DMA_ClearFlag(sEE_I2C_DMA_STREAM_TX, sEE_TX_DMA_FLAG_TCIF);

    /*!< Wait till all data have been physically transferred on the bus */
    sEETimeout = sEE_LONG_TIMEOUT;
    while(!I2C_GetFlagStatus(sEE_I2C, I2C_FLAG_BTF))
    {
      if((sEETimeout--) == 0) sEE_TIMEOUT_UserCallback();
    }
    
    /*!< Send STOP condition */
    I2C_GenerateSTOP(sEE_I2C, ENABLE);
    
    /* Reset the variable holding the number of data to be written */
    *sEEDataWritePointer = 0;  
  }
}

/**
  * @brief  This function handles the DMA Rx Channel interrupt Handler.
  * @param  None
  * @retval None
  */
void sEE_I2C_DMA_RX_IRQHandler(void)
{
  /* Check if the DMA transfer is complete */
  if(DMA_GetFlagStatus(sEE_I2C_DMA_STREAM_RX, sEE_RX_DMA_FLAG_TCIF) != RESET)
  {      
    /*!< Send STOP Condition */
    I2C_GenerateSTOP(sEE_I2C, ENABLE);    
    
    /* Disable the DMA Rx Stream and Clear TC Flag */  
    DMA_Cmd(sEE_I2C_DMA_STREAM_RX, DISABLE);
    DMA_ClearFlag(sEE_I2C_DMA_STREAM_RX, sEE_RX_DMA_FLAG_TCIF);
    
    /* Reset the variable holding the number of data to be read */
    *sEEDataReadPointer = 0;
  }
}

#ifdef USE_DEFAULT_TIMEOUT_CALLBACK
/**
  * @brief  Basic management of the timeout situation.
  * @param  None.
  * @retval None.
  */
uint32_t sEE_TIMEOUT_UserCallback(void)
{
  /* Block communication and all processes */
  while (1)
  {   
  }
}
#endif /* USE_DEFAULT_TIMEOUT_CALLBACK */

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */  

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