of/promtree: allow DT device matching by fixing 'name' brokenness (v5)
[linux-2.6.git] / 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/irq.h>
16 #include <linux/of.h>
17 #include <linux/of_i2c.h>
18 #include <linux/of_irq.h>
19 #include <linux/module.h>
20
21 void of_i2c_register_devices(struct i2c_adapter *adap)
22 {
23         void *result;
24         struct device_node *node;
25
26         /* Only register child devices if the adapter has a node pointer set */
27         if (!adap->dev.of_node)
28                 return;
29
30         dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
31
32         for_each_child_of_node(adap->dev.of_node, node) {
33                 struct i2c_board_info info = {};
34                 struct dev_archdata dev_ad = {};
35                 const __be32 *addr;
36                 int len;
37
38                 dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
39
40                 if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
41                         dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
42                                 node->full_name);
43                         continue;
44                 }
45
46                 addr = of_get_property(node, "reg", &len);
47                 if (!addr || (len < sizeof(int))) {
48                         dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
49                                 node->full_name);
50                         continue;
51                 }
52
53                 info.addr = be32_to_cpup(addr);
54                 if (info.addr > (1 << 10) - 1) {
55                         dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
56                                 info.addr, node->full_name);
57                         continue;
58                 }
59
60                 info.irq = irq_of_parse_and_map(node, 0);
61                 info.of_node = of_node_get(node);
62                 info.archdata = &dev_ad;
63
64                 request_module("%s%s", I2C_MODULE_PREFIX, info.type);
65
66                 result = i2c_new_device(adap, &info);
67                 if (result == NULL) {
68                         dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
69                                 node->full_name);
70                         of_node_put(node);
71                         irq_dispose_mapping(info.irq);
72                         continue;
73                 }
74         }
75 }
76 EXPORT_SYMBOL(of_i2c_register_devices);
77
78 static int of_dev_node_match(struct device *dev, void *data)
79 {
80         return dev->of_node == data;
81 }
82
83 /* must call put_device() when done with returned i2c_client device */
84 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
85 {
86         struct device *dev;
87
88         dev = bus_find_device(&i2c_bus_type, NULL, node,
89                                          of_dev_node_match);
90         if (!dev)
91                 return NULL;
92
93         return to_i2c_client(dev);
94 }
95 EXPORT_SYMBOL(of_find_i2c_device_by_node);
96
97 MODULE_LICENSE("GPL");