tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
25static 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 */
50static 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 unsigned char msg[bytes + 2];
55 int ret;
56
57 reg = cpu_to_be16(reg);
58 memcpy(&msg[0], ®, 2);
59 memcpy(&msg[2], src, bytes);
60
61 ret = i2c_master_send(i2c, msg, bytes + 2);
62 if (ret < 0)
63 return ret;
64 if (ret < bytes + 2)
65 return -EIO;
66
67 return 0;
68}
69
70static int wm831x_i2c_probe(struct i2c_client *i2c,
71 const struct i2c_device_id *id)
72{
73 struct wm831x *wm831x;
74
75 wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
76 if (wm831x == NULL)
77 return -ENOMEM;
78
79 i2c_set_clientdata(i2c, wm831x);
80 wm831x->dev = &i2c->dev;
81 wm831x->control_data = i2c;
82 wm831x->read_dev = wm831x_i2c_read_device;
83 wm831x->write_dev = wm831x_i2c_write_device;
84
85 return wm831x_device_init(wm831x, id->driver_data, i2c->irq);
86}
87
88static int wm831x_i2c_remove(struct i2c_client *i2c)
89{
90 struct wm831x *wm831x = i2c_get_clientdata(i2c);
91
92 wm831x_device_exit(wm831x);
93
94 return 0;
95}
96
97static int wm831x_i2c_suspend(struct i2c_client *i2c, pm_message_t mesg)
98{
99 struct wm831x *wm831x = i2c_get_clientdata(i2c);
100
101 return wm831x_device_suspend(wm831x);
102}
103
104static const struct i2c_device_id wm831x_i2c_id[] = {
105 { "wm8310", WM8310 },
106 { "wm8311", WM8311 },
107 { "wm8312", WM8312 },
108 { "wm8320", WM8320 },
109 { "wm8321", WM8321 },
110 { "wm8325", WM8325 },
111 { }
112};
113MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id);
114
115
116static struct i2c_driver wm831x_i2c_driver = {
117 .driver = {
118 .name = "wm831x",
119 .owner = THIS_MODULE,
120 },
121 .probe = wm831x_i2c_probe,
122 .remove = wm831x_i2c_remove,
123 .suspend = wm831x_i2c_suspend,
124 .id_table = wm831x_i2c_id,
125};
126
127static int __init wm831x_i2c_init(void)
128{
129 int ret;
130
131 ret = i2c_add_driver(&wm831x_i2c_driver);
132 if (ret != 0)
133 pr_err("Failed to register wm831x I2C driver: %d\n", ret);
134
135 return ret;
136}
137subsys_initcall(wm831x_i2c_init);
138
139static void __exit wm831x_i2c_exit(void)
140{
141 i2c_del_driver(&wm831x_i2c_driver);
142}
143module_exit(wm831x_i2c_exit);