drivers/gpio/max7300.c

   1 /*
   2  * drivers/gpio/max7300.c
   3  *
   4  * Copyright (C) 2009 Wolfram Sang, Pengutronix
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Check max730x.c for further details.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/mutex.h>
  17 #include <linux/i2c.h>
  18 #include <linux/spi/max7301.h>
  19
  20 static int max7300_i2c_write(struct device *dev, unsigned int reg,
  21                                 unsigned int val)
  22 {
  23         struct i2c_client *client = to_i2c_client(dev);
  24
  25         return i2c_smbus_write_byte_data(client, reg, val);
  26 }
  27
  28 static int max7300_i2c_read(struct device *dev, unsigned int reg)
  29 {
  30         struct i2c_client *client = to_i2c_client(dev);
  31
  32         return i2c_smbus_read_byte_data(client, reg);
  33 }
  34
  35 static int __devinit max7300_probe(struct i2c_client *client,
  36                          const struct i2c_device_id *id)
  37 {
  38         struct max7301 *ts;
  39         int ret;
  40
  41         if (!i2c_check_functionality(client->adapter,
  42                         I2C_FUNC_SMBUS_BYTE_DATA))
  43                 return -EIO;
  44
  45         ts = kzalloc(sizeof(struct max7301), GFP_KERNEL);
  46         if (!ts)
  47                 return -ENOMEM;
  48
  49         ts->read = max7300_i2c_read;
  50         ts->write = max7300_i2c_write;
  51         ts->dev = &client->dev;
  52
  53         ret = __max730x_probe(ts);
  54         if (ret)
  55                 kfree(ts);
  56         return ret;
  57 }
  58
  59 static int __devexit max7300_remove(struct i2c_client *client)
  60 {
  61         return __max730x_remove(&client->dev);
  62 }
  63
  64 static const struct i2c_device_id max7300_id[] = {
  65         { "max7300", 0 },
  66         { }
  67 };
  68 MODULE_DEVICE_TABLE(i2c, max7300_id);
  69
  70 static struct i2c_driver max7300_driver = {
  71         .driver = {
  72                 .name = "max7300",
  73                 .owner = THIS_MODULE,
  74         },
  75         .probe = max7300_probe,
  76         .remove = __devexit_p(max7300_remove),
  77         .id_table = max7300_id,
  78 };
  79
  80 static int __init max7300_init(void)
  81 {
  82         return i2c_add_driver(&max7300_driver);
  83 }
  84 subsys_initcall(max7300_init);
  85
  86 static void __exit max7300_exit(void)
  87 {
  88         i2c_del_driver(&max7300_driver);
  89 }
  90 module_exit(max7300_exit);
  91
  92 MODULE_AUTHOR("Wolfram Sang");
  93 MODULE_LICENSE("GPL v2");
  94 MODULE_DESCRIPTION("MAX7300 GPIO-Expander");