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 #include <linux/slab.h>
  23
  24 static int wm8350_i2c_read_device(struct wm8350 *wm8350, char reg,
  25                                   int bytes, void *dest)
  26 {
  27         int ret;
  28
  29         ret = i2c_master_send(wm8350->i2c_client, &reg, 1);
  30         if (ret < 0)
  31                 return ret;
  32         ret = i2c_master_recv(wm8350->i2c_client, dest, bytes);
  33         if (ret < 0)
  34                 return ret;
  35         if (ret != bytes)
  36                 return -EIO;
  37         return 0;
  38 }
  39
  40 static int wm8350_i2c_write_device(struct wm8350 *wm8350, char reg,
  41                                    int bytes, void *src)
  42 {
  43         /* we add 1 byte for device register */
  44         u8 msg[(WM8350_MAX_REGISTER << 1) + 1];
  45         int ret;
  46
  47         if (bytes > ((WM8350_MAX_REGISTER << 1) + 1))
  48                 return -EINVAL;
  49
  50         msg[0] = reg;
  51         memcpy(&msg[1], src, bytes);
  52         ret = i2c_master_send(wm8350->i2c_client, msg, bytes + 1);
  53         if (ret < 0)
  54                 return ret;
  55         if (ret != bytes + 1)
  56                 return -EIO;
  57         return 0;
  58 }
  59
  60 static int wm8350_i2c_probe(struct i2c_client *i2c,
  61                             const struct i2c_device_id *id)
  62 {
  63         struct wm8350 *wm8350;
  64         int ret = 0;
  65
  66         wm8350 = devm_kzalloc(&i2c->dev, sizeof(struct wm8350), GFP_KERNEL);
  67         if (wm8350 == NULL)
  68                 return -ENOMEM;
  69
  70         i2c_set_clientdata(i2c, wm8350);
  71         wm8350->dev = &i2c->dev;
  72         wm8350->i2c_client = i2c;
  73         wm8350->read_dev = wm8350_i2c_read_device;
  74         wm8350->write_dev = wm8350_i2c_write_device;
  75
  76         ret = wm8350_device_init(wm8350, i2c->irq, i2c->dev.platform_data);
  77         if (ret < 0)
  78                 goto err;
  79
  80         return ret;
  81
  82 err:
  83         return ret;
  84 }
  85
  86 static int wm8350_i2c_remove(struct i2c_client *i2c)
  87 {
  88         struct wm8350 *wm8350 = i2c_get_clientdata(i2c);
  89
  90         wm8350_device_exit(wm8350);
  91
  92         return 0;
  93 }
  94
  95 static const struct i2c_device_id wm8350_i2c_id[] = {
  96        { "wm8350", 0 },
  97        { "wm8351", 0 },
  98        { "wm8352", 0 },
  99        { }
 100 };
 101 MODULE_DEVICE_TABLE(i2c, wm8350_i2c_id);
 102
 103
 104 static struct i2c_driver wm8350_i2c_driver = {
 105         .driver = {
 106                    .name = "wm8350",
 107                    .owner = THIS_MODULE,
 108         },
 109         .probe = wm8350_i2c_probe,
 110         .remove = wm8350_i2c_remove,
 111         .id_table = wm8350_i2c_id,
 112 };
 113
 114 static int __init wm8350_i2c_init(void)
 115 {
 116         return i2c_add_driver(&wm8350_i2c_driver);
 117 }
 118 /* init early so consumer devices can complete system boot */
 119 subsys_initcall(wm8350_i2c_init);
 120
 121 static void __exit wm8350_i2c_exit(void)
 122 {
 123         i2c_del_driver(&wm8350_i2c_driver);
 124 }
 125 module_exit(wm8350_i2c_exit);
 126
 127 MODULE_DESCRIPTION("I2C support for the WM8350 AudioPlus PMIC");
 128 MODULE_LICENSE("GPL");