tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
19void 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}
67EXPORT_SYMBOL(of_register_i2c_devices);
68
69static 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 */
75struct 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}
86EXPORT_SYMBOL(of_find_i2c_device_by_node);
87
88MODULE_LICENSE("GPL");