drivers/staging/sm750fb/ddk750_swi2c.h

   1 /*******************************************************************
   2 *
   3 *         Copyright (c) 2007 by Silicon Motion, Inc. (SMI)
   4 *
   5 *  All rights are reserved. Reproduction or in part is prohibited
   6 *  without the written consent of the copyright owner.
   7 *
   8 *  swi2c.h --- SM750/SM718 DDK
   9 *  This file contains the definitions for i2c using software
  10 *  implementation.
  11 *
  12 *******************************************************************/
  13 #ifndef _SWI2C_H_
  14 #define _SWI2C_H_
  15
  16 /* Default i2c CLK and Data GPIO. These are the default i2c pins */
  17 #define DEFAULT_I2C_SCL                     30
  18 #define DEFAULT_I2C_SDA                     31
  19
  20 /*
  21  * This function initializes the i2c attributes and bus
  22  *
  23  * Parameters:
  24  *      i2cClkGPIO  - The GPIO pin to be used as i2c SCL
  25  *      i2cDataGPIO - The GPIO pin to be used as i2c SDA
  26  *
  27  * Return Value:
  28  *      -1   - Fail to initialize the i2c
  29  *       0   - Success
  30  */
  31 long swI2CInit(
  32     unsigned char i2cClkGPIO,
  33     unsigned char i2cDataGPIO
  34 );
  35
  36 /*
  37  *  This function reads the slave device's register
  38  *
  39  *  Parameters:
  40  *      deviceAddress   - i2c Slave device address which register
  41  *                        to be read from
  42  *      registerIndex   - Slave device's register to be read
  43  *
  44  *  Return Value:
  45  *      Register value
  46  */
  47 unsigned char swI2CReadReg(
  48     unsigned char deviceAddress,
  49     unsigned char registerIndex
  50 );
  51
  52 /*
  53  *  This function writes a value to the slave device's register
  54  *
  55  *  Parameters:
  56  *      deviceAddress   - i2c Slave device address which register
  57  *                        to be written
  58  *      registerIndex   - Slave device's register to be written
  59  *      data            - Data to be written to the register
  60  *
  61  *  Result:
  62  *          0   - Success
  63  *         -1   - Fail
  64  */
  65 long swI2CWriteReg(
  66     unsigned char deviceAddress,
  67     unsigned char registerIndex,
  68     unsigned char data
  69 );
  70
  71 /*
  72  *  These two functions are used to toggle the data on the SCL and SDA I2C lines.
  73  *  The used of these two functions are not recommended unless it is necessary.
  74  */
  75
  76 /*
  77  *  This function set/reset the SCL GPIO pin
  78  *
  79  *  Parameters:
  80  *      value   - Bit value to set to the SCL or SDA (0 = low, 1 = high)
  81  */
  82 void swI2CSCL(unsigned char value);
  83
  84 /*
  85  *  This function set/reset the SDA GPIO pin
  86  *
  87  *  Parameters:
  88  *      value   - Bit value to set to the SCL or SDA (0 = low, 1 = high)
  89  */
  90 void swI2CSDA(unsigned char value);
  91
  92 #endif  /* _SWI2C_H_ */