Merge branch 'fix/asoc' into for-linus
[linux-2.6] / drivers / of / of_i2c.c
1 /*
2  * OF helpers for the I2C API
3  *
4  * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
5  *
6  * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13
14 #include <linux/i2c.h>
15 #include <linux/of.h>
16 #include <linux/of_i2c.h>
17 #include <linux/module.h>
18
19 void of_register_i2c_devices(struct i2c_adapter *adap,
20                              struct device_node *adap_node)
21 {
22         void *result;
23         struct device_node *node;
24
25         for_each_child_of_node(adap_node, node) {
26                 struct i2c_board_info info = {};
27                 struct dev_archdata dev_ad = {};
28                 const u32 *addr;
29                 int len;
30
31                 if (of_modalias_node(node, info.type, sizeof(info.type)) < 0)
32                         continue;
33
34                 addr = of_get_property(node, "reg", &len);
35                 if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) {
36                         printk(KERN_ERR
37                                "of-i2c: invalid i2c device entry\n");
38                         continue;
39                 }
40
41                 info.irq = irq_of_parse_and_map(node, 0);
42
43                 info.addr = *addr;
44
45                 dev_archdata_set_node(&dev_ad, node);
46                 info.archdata = &dev_ad;
47
48                 request_module("%s", info.type);
49
50                 result = i2c_new_device(adap, &info);
51                 if (result == NULL) {
52                         printk(KERN_ERR
53                                "of-i2c: Failed to load driver for %s\n",
54                                info.type);
55                         irq_dispose_mapping(info.irq);
56                         continue;
57                 }
58
59                 /*
60                  * Get the node to not lose the dev_archdata->of_node.
61                  * Currently there is no way to put it back, as well as no
62                  * of_unregister_i2c_devices() call.
63                  */
64                 of_node_get(node);
65         }
66 }
67 EXPORT_SYMBOL(of_register_i2c_devices);
68
69 static int of_dev_node_match(struct device *dev, void *data)
70 {
71         return dev_archdata_get_node(&dev->archdata) == data;
72 }
73
74 /* must call put_device() when done with returned i2c_client device */
75 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
76 {
77         struct device *dev;
78
79         dev = bus_find_device(&i2c_bus_type, NULL, node,
80                                          of_dev_node_match);
81         if (!dev)
82                 return NULL;
83
84         return to_i2c_client(dev);
85 }
86 EXPORT_SYMBOL(of_find_i2c_device_by_node);
87
88 MODULE_LICENSE("GPL");