linux/drivers/mfd/wm8350-i2c.c
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   1/*
   2 * wm8350-i2c.c  --  Generic I2C driver for Wolfson WM8350 PMIC
   3 *
   4 * This driver defines and configures the WM8350 for the Freescale i.MX32ADS.
   5 *
   6 * Copyright 2007, 2008 Wolfson Microelectronics PLC.
   7 *
   8 * Author: Liam Girdwood
   9 *         linux@wolfsonmicro.com
  10 *
  11 *  This program is free software; you can redistribute  it and/or modify it
  12 *  under  the terms of  the GNU General  Public License as published by the
  13 *  Free Software Foundation;  either version 2 of the  License, or (at your
  14 *  option) any later version.
  15 *
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/moduleparam.h>
  20#include <linux/init.h>
  21#include <linux/i2c.h>
  22#include <linux/platform_device.h>
  23#include <linux/mfd/wm8350/core.h>
  24
  25static int wm8350_i2c_read_device(struct wm8350 *wm8350, char reg,
  26                                  int bytes, void *dest)
  27{
  28        int ret;
  29
  30        ret = i2c_master_send(wm8350->i2c_client, &reg, 1);
  31        if (ret < 0)
  32                return ret;
  33        ret = i2c_master_recv(wm8350->i2c_client, dest, bytes);
  34        if (ret < 0)
  35                return ret;
  36        if (ret != bytes)
  37                return -EIO;
  38        return 0;
  39}
  40
  41static int wm8350_i2c_write_device(struct wm8350 *wm8350, char reg,
  42                                   int bytes, void *src)
  43{
  44        /* we add 1 byte for device register */
  45        u8 msg[(WM8350_MAX_REGISTER << 1) + 1];
  46        int ret;
  47
  48        if (bytes > ((WM8350_MAX_REGISTER << 1) + 1))
  49                return -EINVAL;
  50
  51        msg[0] = reg;
  52        memcpy(&msg[1], src, bytes);
  53        ret = i2c_master_send(wm8350->i2c_client, msg, bytes + 1);
  54        if (ret < 0)
  55                return ret;
  56        if (ret != bytes + 1)
  57                return -EIO;
  58        return 0;
  59}
  60
  61static int wm8350_i2c_probe(struct i2c_client *i2c,
  62                            const struct i2c_device_id *id)
  63{
  64        struct wm8350 *wm8350;
  65        int ret = 0;
  66
  67        wm8350 = kzalloc(sizeof(struct wm8350), GFP_KERNEL);
  68        if (wm8350 == NULL) {
  69                kfree(i2c);
  70                return -ENOMEM;
  71        }
  72
  73        i2c_set_clientdata(i2c, wm8350);
  74        wm8350->dev = &i2c->dev;
  75        wm8350->i2c_client = i2c;
  76        wm8350->read_dev = wm8350_i2c_read_device;
  77        wm8350->write_dev = wm8350_i2c_write_device;
  78
  79        ret = wm8350_device_init(wm8350, i2c->irq, i2c->dev.platform_data);
  80        if (ret < 0)
  81                goto err;
  82
  83        return ret;
  84
  85err:
  86        kfree(wm8350);
  87        return ret;
  88}
  89
  90static int wm8350_i2c_remove(struct i2c_client *i2c)
  91{
  92        struct wm8350 *wm8350 = i2c_get_clientdata(i2c);
  93
  94        wm8350_device_exit(wm8350);
  95        kfree(wm8350);
  96
  97        return 0;
  98}
  99
 100static const struct i2c_device_id wm8350_i2c_id[] = {
 101       { "wm8350", 0 },
 102       { }
 103};
 104MODULE_DEVICE_TABLE(i2c, wm8350_i2c_id);
 105
 106
 107static 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
 117static 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 */
 122subsys_initcall(wm8350_i2c_init);
 123
 124static void __exit wm8350_i2c_exit(void)
 125{
 126        i2c_del_driver(&wm8350_i2c_driver);
 127}
 128module_exit(wm8350_i2c_exit);
 129
 130MODULE_DESCRIPTION("I2C support for the WM8350 AudioPlus PMIC");
 131MODULE_LICENSE("GPL");
 132