linux/drivers/mfd/wm8350-i2c.c
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   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
  24static 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
  40static 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
  60static 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 = kzalloc(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
  82err:
  83        kfree(wm8350);
  84        return ret;
  85}
  86
  87static int wm8350_i2c_remove(struct i2c_client *i2c)
  88{
  89        struct wm8350 *wm8350 = i2c_get_clientdata(i2c);
  90
  91        wm8350_device_exit(wm8350);
  92        kfree(wm8350);
  93
  94        return 0;
  95}
  96
  97static const struct i2c_device_id wm8350_i2c_id[] = {
  98       { "wm8350", 0 },
  99       { "wm8351", 0 },
 100       { "wm8352", 0 },
 101       { }
 102};
 103MODULE_DEVICE_TABLE(i2c, wm8350_i2c_id);
 104
 105
 106static struct i2c_driver wm8350_i2c_driver = {
 107        .driver = {
 108                   .name = "wm8350",
 109                   .owner = THIS_MODULE,
 110        },
 111        .probe = wm8350_i2c_probe,
 112        .remove = wm8350_i2c_remove,
 113        .id_table = wm8350_i2c_id,
 114};
 115
 116static int __init wm8350_i2c_init(void)
 117{
 118        return i2c_add_driver(&wm8350_i2c_driver);
 119}
 120/* init early so consumer devices can complete system boot */
 121subsys_initcall(wm8350_i2c_init);
 122
 123static void __exit wm8350_i2c_exit(void)
 124{
 125        i2c_del_driver(&wm8350_i2c_driver);
 126}
 127module_exit(wm8350_i2c_exit);
 128
 129MODULE_DESCRIPTION("I2C support for the WM8350 AudioPlus PMIC");
 130MODULE_LICENSE("GPL");
 131