a06cbc739716c25c57ae872f90c2ba9cc6fa506d
[linux-2.6.git] / drivers / mfd / wm831x-i2c.c
1 /*
2  * wm831x-i2c.c  --  I2C access for Wolfson WM831x PMICs
3  *
4  * Copyright 2009,2010 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/i2c.h>
18 #include <linux/delay.h>
19 #include <linux/mfd/core.h>
20 #include <linux/slab.h>
21
22 #include <linux/mfd/wm831x/core.h>
23 #include <linux/mfd/wm831x/pdata.h>
24
25 static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg,
26                                   int bytes, void *dest)
27 {
28         struct i2c_client *i2c = wm831x->control_data;
29         int ret;
30         u16 r = cpu_to_be16(reg);
31
32         ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
33         if (ret < 0)
34                 return ret;
35         if (ret != 2)
36                 return -EIO;
37
38         ret = i2c_master_recv(i2c, dest, bytes);
39         if (ret < 0)
40                 return ret;
41         if (ret != bytes)
42                 return -EIO;
43         return 0;
44 }
45
46 /* Currently we allocate the write buffer on the stack; this is OK for
47  * small writes - if we need to do large writes this will need to be
48  * revised.
49  */
50 static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg,
51                                    int bytes, void *src)
52 {
53         struct i2c_client *i2c = wm831x->control_data;
54         struct i2c_msg xfer[2];
55         int ret;
56
57         reg = cpu_to_be16(reg);
58
59         xfer[0].addr = i2c->addr;
60         xfer[0].flags = 0;
61         xfer[0].len = 2;
62         xfer[0].buf = (char *)&reg;
63
64         xfer[1].addr = i2c->addr;
65         xfer[1].flags = I2C_M_NOSTART;
66         xfer[1].len = bytes;
67         xfer[1].buf = (char *)src;
68
69         ret = i2c_transfer(i2c->adapter, xfer, 2);
70         if (ret < 0)
71                 return ret;
72         if (ret != 2)
73                 return -EIO;
74
75         return 0;
76 }
77
78 static int wm831x_i2c_probe(struct i2c_client *i2c,
79                             const struct i2c_device_id *id)
80 {
81         struct wm831x *wm831x;
82
83         wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
84         if (wm831x == NULL)
85                 return -ENOMEM;
86
87         i2c_set_clientdata(i2c, wm831x);
88         wm831x->dev = &i2c->dev;
89         wm831x->control_data = i2c;
90         wm831x->read_dev = wm831x_i2c_read_device;
91         wm831x->write_dev = wm831x_i2c_write_device;
92
93         return wm831x_device_init(wm831x, id->driver_data, i2c->irq);
94 }
95
96 static int wm831x_i2c_remove(struct i2c_client *i2c)
97 {
98         struct wm831x *wm831x = i2c_get_clientdata(i2c);
99
100         wm831x_device_exit(wm831x);
101
102         return 0;
103 }
104
105 static int wm831x_i2c_suspend(struct device *dev)
106 {
107         struct wm831x *wm831x = dev_get_drvdata(dev);
108
109         return wm831x_device_suspend(wm831x);
110 }
111
112 static const struct i2c_device_id wm831x_i2c_id[] = {
113         { "wm8310", WM8310 },
114         { "wm8311", WM8311 },
115         { "wm8312", WM8312 },
116         { "wm8320", WM8320 },
117         { "wm8321", WM8321 },
118         { "wm8325", WM8325 },
119         { "wm8326", WM8326 },
120         { }
121 };
122 MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id);
123
124 static const struct dev_pm_ops wm831x_pm_ops = {
125         .suspend = wm831x_i2c_suspend,
126 };
127
128 static struct i2c_driver wm831x_i2c_driver = {
129         .driver = {
130                 .name = "wm831x",
131                 .owner = THIS_MODULE,
132                 .pm = &wm831x_pm_ops,
133         },
134         .probe = wm831x_i2c_probe,
135         .remove = wm831x_i2c_remove,
136         .id_table = wm831x_i2c_id,
137 };
138
139 static int __init wm831x_i2c_init(void)
140 {
141         int ret;
142
143         ret = i2c_add_driver(&wm831x_i2c_driver);
144         if (ret != 0)
145                 pr_err("Failed to register wm831x I2C driver: %d\n", ret);
146
147         return ret;
148 }
149 subsys_initcall(wm831x_i2c_init);
150
151 static void __exit wm831x_i2c_exit(void)
152 {
153         i2c_del_driver(&wm831x_i2c_driver);
154 }
155 module_exit(wm831x_i2c_exit);