1#include <linux/string.h>
2#include <linux/kernel.h>
3#include <linux/of.h>
4#include <linux/of_device.h>
5#include <linux/init.h>
6#include <linux/module.h>
7#include <linux/mod_devicetable.h>
8#include <linux/slab.h>
9
10#include <asm/errno.h>
11
12/**
13 * of_match_device - Tell if a struct device matches an of_device_id list
14 * @ids: array of of device match structures to search in
15 * @dev: the of device structure to match against
16 *
17 * Used by a driver to check whether an platform_device present in the
18 * system is in its list of supported devices.
19 */
20const struct of_device_id *of_match_device(const struct of_device_id *matches,
21					   const struct device *dev)
22{
23	if ((!matches) || (!dev->of_node))
24		return NULL;
25	return of_match_node(matches, dev->of_node);
26}
27EXPORT_SYMBOL(of_match_device);
28
29struct platform_device *of_dev_get(struct platform_device *dev)
30{
31	struct device *tmp;
32
33	if (!dev)
34		return NULL;
35	tmp = get_device(&dev->dev);
36	if (tmp)
37		return to_platform_device(tmp);
38	else
39		return NULL;
40}
41EXPORT_SYMBOL(of_dev_get);
42
43void of_dev_put(struct platform_device *dev)
44{
45	if (dev)
46		put_device(&dev->dev);
47}
48EXPORT_SYMBOL(of_dev_put);
49
50static ssize_t devspec_show(struct device *dev,
51				struct device_attribute *attr, char *buf)
52{
53	struct platform_device *ofdev;
54
55	ofdev = to_platform_device(dev);
56	return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
57}
58
59static ssize_t name_show(struct device *dev,
60				struct device_attribute *attr, char *buf)
61{
62	struct platform_device *ofdev;
63
64	ofdev = to_platform_device(dev);
65	return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
66}
67
68static ssize_t modalias_show(struct device *dev,
69				struct device_attribute *attr, char *buf)
70{
71	ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
72	buf[len] = '\n';
73	buf[len+1] = 0;
74	return len+1;
75}
76
77struct device_attribute of_platform_device_attrs[] = {
78	__ATTR_RO(devspec),
79	__ATTR_RO(name),
80	__ATTR_RO(modalias),
81	__ATTR_NULL
82};
83
84/**
85 * of_release_dev - free an of device structure when all users of it are finished.
86 * @dev: device that's been disconnected
87 *
88 * Will be called only by the device core when all users of this of device are
89 * done.
90 */
91void of_release_dev(struct device *dev)
92{
93	struct platform_device *ofdev;
94
95	ofdev = to_platform_device(dev);
96	of_node_put(ofdev->dev.of_node);
97	kfree(ofdev);
98}
99EXPORT_SYMBOL(of_release_dev);
100
101int of_device_register(struct platform_device *ofdev)
102{
103	BUG_ON(ofdev->dev.of_node == NULL);
104
105	device_initialize(&ofdev->dev);
106
107	/* name and id have to be set so that the platform bus doesn't get
108	 * confused on matching */
109	ofdev->name = dev_name(&ofdev->dev);
110	ofdev->id = -1;
111
112	/* device_add will assume that this device is on the same node as
113	 * the parent. If there is no parent defined, set the node
114	 * explicitly */
115	if (!ofdev->dev.parent)
116		set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
117
118	return device_add(&ofdev->dev);
119}
120EXPORT_SYMBOL(of_device_register);
121
122void of_device_unregister(struct platform_device *ofdev)
123{
124	device_unregister(&ofdev->dev);
125}
126EXPORT_SYMBOL(of_device_unregister);
127
128ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
129{
130	const char *compat;
131	int cplen, i;
132	ssize_t tsize, csize, repend;
133
134	/* Name & Type */
135	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
136			 dev->of_node->type);
137
138	/* Get compatible property if any */
139	compat = of_get_property(dev->of_node, "compatible", &cplen);
140	if (!compat)
141		return csize;
142
143	/* Find true end (we tolerate multiple \0 at the end */
144	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
145		cplen--;
146	if (!cplen)
147		return csize;
148	cplen++;
149
150	/* Check space (need cplen+1 chars including final \0) */
151	tsize = csize + cplen;
152	repend = tsize;
153
154	if (csize >= len)		/* @ the limit, all is already filled */
155		return tsize;
156
157	if (tsize >= len) {		/* limit compat list */
158		cplen = len - csize - 1;
159		repend = len;
160	}
161
162	/* Copy and do char replacement */
163	memcpy(&str[csize + 1], compat, cplen);
164	for (i = csize; i < repend; i++) {
165		char c = str[i];
166		if (c == '\0')
167			str[i] = 'C';
168		else if (c == ' ')
169			str[i] = '_';
170	}
171
172	return tsize;
173}
174
175/**
176 * of_device_uevent - Display OF related uevent information
177 */
178int of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
179{
180	const char *compat;
181	int seen = 0, cplen, sl;
182
183	if ((!dev) || (!dev->of_node))
184		return -ENODEV;
185
186	if (add_uevent_var(env, "OF_NAME=%s", dev->of_node->name))
187		return -ENOMEM;
188
189	if (add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type))
190		return -ENOMEM;
191
192	/* Since the compatible field can contain pretty much anything
193	 * it's not really legal to split it out with commas. We split it
194	 * up using a number of environment variables instead. */
195
196	compat = of_get_property(dev->of_node, "compatible", &cplen);
197	while (compat && *compat && cplen > 0) {
198		if (add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat))
199			return -ENOMEM;
200
201		sl = strlen(compat) + 1;
202		compat += sl;
203		cplen -= sl;
204		seen++;
205	}
206
207	if (add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen))
208		return -ENOMEM;
209
210	/* modalias is trickier, we add it in 2 steps */
211	if (add_uevent_var(env, "MODALIAS="))
212		return -ENOMEM;
213
214	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
215				    sizeof(env->buf) - env->buflen);
216	if (sl >= (sizeof(env->buf) - env->buflen))
217		return -ENOMEM;
218	env->buflen += sl;
219
220	return 0;
221}
222