File content as of revision 0:892175366555:

/**
 ******************************************************************************
 * @file    DevI2C.h
 * @author  AST / EST / AMG-CL
 * @version V0.0.2
 * @date    25-July-2016
 * @brief   Header file for a special I2C class DevI2C which provides some
 *          helper function for on-board communication
 ******************************************************************************
 * @attention
 *
 * <h2><center>&copy; COPYRIGHT(c) 2014 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.
 *
 ******************************************************************************
 */

/* Define to prevent from recursive inclusion --------------------------------*/
#ifndef __DEV_I2C_H
#define __DEV_I2C_H

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

/* Classes -------------------------------------------------------------------*/
/** Helper class DevI2C providing functions for multi-register I2C communication
 *  common for a series of I2C devices
 */
class DevI2C : public I2C
{
 public:
   
   /** Create a DevI2C Master interface, connected to the specified pins
   *
   *  @param sda I2C data line pin
   *  @param scl I2C clock line pin
   */
   DevI2C(PinName sda, PinName scl) : I2C(sda, scl) {}

   /**
   * @brief  Writes a buffer towards the I2C peripheral device.
   * @param  pBuffer pointer to the byte-array data to send
   * @param  DeviceAddr specifies the peripheral device slave address.
   * @param  RegisterAddr specifies the internal address register 
   *         where to start writing to (must be correctly masked).
   * @param  NumByteToWrite number of bytes to be written.
   * @retval 0 if ok, 
   * @retval -1 if an I2C error has occured, or
   * @retval -2 on temporary buffer overflow (i.e. NumByteToWrite was too high)
   * @note   On some devices if NumByteToWrite is greater
   *         than one, the RegisterAddr must be masked correctly!
   */
   int i2c_write(uint8_t* pBuffer, uint8_t DeviceAddr, uint8_t RegisterAddr, 
                 uint16_t NumByteToWrite)
   {
     int ret;
     uint8_t tmp[TEMP_BUF_SIZE];
     
     if(NumByteToWrite >= TEMP_BUF_SIZE) return -2;
     
     /* First, send device address. Then, send data and STOP condition */
     tmp[0] = RegisterAddr;
     memcpy(tmp+1, pBuffer, NumByteToWrite);
     
     ret = write(DeviceAddr, (const char*)tmp, NumByteToWrite+1, false);
     
     if(ret) return -1;
     return 0;
   }
        
   /**
   * @brief  Writes a buffer towards the I2C peripheral device.
   * @param  pBuffer pointer to the byte-array data to send
   * @param  DeviceAddr specifies the peripheral device slave address.
   * @param  RegisterAddr specifies the internal address register 
   *         where to start writing to (must be correctly masked).
   * @param  NumByteToWrite number of bytes to be written.
   * @retval 0 if ok, 
   * @retval -1 if an I2C error has occured, or
   * @retval -2 on temporary buffer overflow (i.e. NumByteToWrite was too high)
   * @note   On some devices if NumByteToWrite is greater
   *         than one, the RegisterAddr must be masked correctly!
   */
   int i2c_write(uint8_t* pBuffer, uint8_t DeviceAddr, uint16_t RegisterAddr, 
                 uint16_t NumByteToWrite)
   {
     int ret;
     uint8_t tmp[TEMP_BUF_SIZE];
     
     if(NumByteToWrite >= TEMP_BUF_SIZE) return -2;
     
     /* First, send device address. Then, send data and STOP condition */
     tmp[0] = (RegisterAddr >> 8) & 0xFF;
     tmp[1] = (RegisterAddr) & 0xFF;
     memcpy(tmp+2, pBuffer, NumByteToWrite);
     
     ret = write(DeviceAddr, (const char*)tmp, NumByteToWrite+2, false);
     
     if(ret) return -1;
     return 0;
   }
   /**
   * @brief  Reads a buffer from the I2C peripheral device.
   * @param  pBuffer pointer to the byte-array to read data in to
   * @param  DaviceAddr specifies the peripheral device slave address.
   * @param  RegisterAddr specifies the internal address register 
   *         where to start reading from (must be correctly masked).
   * @param  NumByteToRead number of bytes to be read.
   * @retval 0 if ok, 
   * @retval -1 if an I2C error has occured
   * @note   On some devices if NumByteToWrite is greater
   *         than one, the RegisterAddr must be masked correctly!
   */
   int i2c_read(uint8_t* pBuffer, uint8_t DeviceAddr, uint16_t RegisterAddr, 
                uint16_t NumByteToRead)
   {
     int ret;
     uint8_t reg_addr[2];
     reg_addr[0] = (RegisterAddr >> 8) & 0xFF;
     reg_addr[1] = (RegisterAddr) & 0xFF;
     /* Send device address, with no STOP condition */
     ret = write(DeviceAddr, (const char*)reg_addr, 2, true);
     if(!ret) {
       /* Read data, with STOP condition  */
       ret = read(DeviceAddr, (char*)pBuffer, NumByteToRead, false);
     }
     
     if(ret) 
       return -1;
     else
       return 0;
   }
   
   /**
   * @brief  Reads a buffer from the I2C peripheral device.
   * @param  pBuffer pointer to the byte-array to read data in to
   * @param  DaviceAddr specifies the peripheral device slave address.
   * @param  RegisterAddr specifies the internal address register 
   *         where to start reading from (must be correctly masked).
   * @param  NumByteToRead number of bytes to be read.
   * @retval 0 if ok, 
   * @retval -1 if an I2C error has occured
   * @note   On some devices if NumByteToWrite is greater
   *         than one, the RegisterAddr must be masked correctly!
   */
   int i2c_read(uint8_t* pBuffer, uint8_t DeviceAddr, uint8_t RegisterAddr, 
                uint16_t NumByteToRead)
   {
     int ret;
     
     /* Send device address, with no STOP condition */
     ret = write(DeviceAddr, (const char*)&RegisterAddr, 1, true);
     if(!ret) {
       /* Read data, with STOP condition  */
       ret = read(DeviceAddr, (char*)pBuffer, NumByteToRead, false);
     }
     
     if(ret) return -1;
     return 0;
   }
   
private:
  static const unsigned int TEMP_BUF_SIZE = 32;
};

#endif /* __DEV_I2C_H */