drivers/mfd/wm8350-i2c.c

   1 /*
   2  * wm8350-i2c.c  --  Generic I2C driver for Wolfson WM8350 PMIC
   3  *
   4  * Copyright 2007, 2008 Wolfson Microelectronics PLC.
   5  *
   6  * Author: Liam Girdwood
   7  *         linux@wolfsonmicro.com
   8  *
   9  *  This program is free software; you can redistribute  it and/or modify it
  10  *  under  the terms of  the GNU General  Public License as published by the
  11  *  Free Software Foundation;  either version 2 of the  License, or (at your
  12  *  option) any later version.
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/init.h>
  19 #include <linux/i2c.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/mfd/wm8350/core.h>
  22
  23 static int wm8350_i2c_read_device(struct wm8350 *wm8350, char reg,
  24                                   int bytes, void *dest)
  25 {
  26         int ret;
  27
  28         ret = i2c_master_send(wm8350->i2c_client, &reg, 1);
  29         if (ret < 0)
  30                 return ret;
  31         ret = i2c_master_recv(wm8350->i2c_client, dest, bytes);
  32         if (ret < 0)
  33                 return ret;
  34         if (ret != bytes)
  35                 return -EIO;
  36         return 0;
  37 }
  38
  39 static int wm8350_i2c_write_device(struct wm8350 *wm8350, char reg,
  40                                    int bytes, void *src)
  41 {
  42         /* we add 1 byte for device register */
  43         u8 msg[(WM8350_MAX_REGISTER << 1) + 1];
  44         int ret;
  45
  46         if (bytes > ((WM8350_MAX_REGISTER << 1) + 1))
  47                 return -EINVAL;
  48
  49         msg[0] = reg;
  50         memcpy(&msg[1], src, bytes);
  51         ret = i2c_master_send(wm8350->i2c_client, msg, bytes + 1);
  52         if (ret < 0)
  53                 return ret;
  54         if (ret != bytes + 1)
  55                 return -EIO;
  56         return 0;
  57 }
  58
  59 static int wm8350_i2c_probe(struct i2c_client *i2c,
  60                             const struct i2c_device_id *id)
  61 {
  62         struct wm8350 *wm8350;
  63         int ret = 0;
  64
  65         wm8350 = kzalloc(sizeof(struct wm8350), GFP_KERNEL);
  66         if (wm8350 == NULL) {
  67                 kfree(i2c);
  68                 return -ENOMEM;
  69         }
  70
  71         i2c_set_clientdata(i2c, wm8350);
  72         wm8350->dev = &i2c->dev;
  73         wm8350->i2c_client = i2c;
  74         wm8350->read_dev = wm8350_i2c_read_device;
  75         wm8350->write_dev = wm8350_i2c_write_device;
  76
  77         ret = wm8350_device_init(wm8350, i2c->irq, i2c->dev.platform_data);
  78         if (ret < 0)
  79                 goto err;
  80
  81         return ret;
  82
  83 err:
  84         kfree(wm8350);
  85         return ret;
  86 }
  87
  88 static int wm8350_i2c_remove(struct i2c_client *i2c)
  89 {
  90         struct wm8350 *wm8350 = i2c_get_clientdata(i2c);
  91
  92         wm8350_device_exit(wm8350);
  93         kfree(wm8350);
  94
  95         return 0;
  96 }
  97
  98 static const struct i2c_device_id wm8350_i2c_id[] = {
  99        { "wm8350", 0 },
 100        { "wm8351", 0 },
 101        { "wm8352", 0 },
 102        { }
 103 };
 104 MODULE_DEVICE_TABLE(i2c, wm8350_i2c_id);
 105
 106
 107 static struct i2c_driver wm8350_i2c_driver = {
 108         .driver = {
 109                    .name = "wm8350",
 110                    .owner = THIS_MODULE,
 111         },
 112         .probe = wm8350_i2c_probe,
 113         .remove = wm8350_i2c_remove,
 114         .id_table = wm8350_i2c_id,
 115 };
 116
 117 static int __init wm8350_i2c_init(void)
 118 {
 119         return i2c_add_driver(&wm8350_i2c_driver);
 120 }
 121 /* init early so consumer devices can complete system boot */
 122 subsys_initcall(wm8350_i2c_init);
 123
 124 static void __exit wm8350_i2c_exit(void)
 125 {
 126         i2c_del_driver(&wm8350_i2c_driver);
 127 }
 128 module_exit(wm8350_i2c_exit);
 129
 130 MODULE_DESCRIPTION("I2C support for the WM8350 AudioPlus PMIC");
 131 MODULE_LICENSE("GPL");