drivers/i2c/chips/gpio_expander_omap.c

   1 /*
   2  * drivers/i2c/chips/gpio_expander_omap.c
   3  *
   4  * Copyright (C) 2004 Texas Instruments Inc
   5  * Author:
   6  *
   7  * gpio expander is used to configure IrDA, camera and audio devices on omap 1710 processor.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 #include <linux/types.h>
  16 #include <linux/i2c.h>
  17 #include <linux/errno.h>
  18
  19 int read_gpio_expa(u8 * val, int addr);
  20 int write_gpio_expa(u8 val, int addr);
  21
  22 int write_gpio_expa(u8 val, int addr)
  23 {
  24         struct i2c_adapter *adap;
  25         int err;
  26         struct i2c_msg msg[1];
  27         unsigned char data[1];
  28
  29         adap = i2c_get_adapter(1);
  30         if (!adap)
  31                 return -ENODEV;
  32         msg->addr = addr;       /* I2C address of GPIO EXPA */
  33         msg->flags = 0;
  34         msg->len = 1;
  35         msg->buf = data;
  36         data[0] = val;
  37         err = i2c_transfer(adap, msg, 1);
  38         if (err >= 0)
  39                 return 0;
  40         return err;
  41 }
  42
  43 /* Read from I/O EXPANDER on the H3 board.
  44  * The IO expanders need an independent I2C client driver.
  45  */
  46
  47 int read_gpio_expa(u8 * val, int addr)
  48 {
  49         struct i2c_adapter *adap;
  50         int err;
  51         struct i2c_msg msg[1];
  52         unsigned char data[1];
  53
  54         adap = i2c_get_adapter(1);
  55         if (!adap)
  56                 return -ENODEV;
  57         msg->addr = addr;       /* I2C address of GPIO EXPA */
  58         msg->flags = I2C_M_RD;
  59         msg->len = 2;
  60         msg->buf = data;
  61         err = i2c_transfer(adap, msg, 1);
  62         *val = data[0];
  63
  64         if (err >= 0)
  65                 return 0;
  66         return err;
  67 }
  68
  69 EXPORT_SYMBOL(read_gpio_expa);
  70 EXPORT_SYMBOL(write_gpio_expa);
  71