drivers/mfd/wm8350-i2c.c

   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
  25 static 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
  41 static 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
  61 static 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
  85 err:
  86         kfree(wm8350);
  87         return ret;
  88 }
  89
  90 static 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
 100 static const struct i2c_device_id wm8350_i2c_id[] = {
 101        { "wm8350", 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");