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
21void 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}
76EXPORT_SYMBOL(of_i2c_register_devices);
77
78static 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 */
84struct 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}
95EXPORT_SYMBOL(of_find_i2c_device_by_node);
96
97MODULE_LICENSE("GPL");