1#include <linux/string.h>
2#include <linux/kernel.h>
3#include <linux/init.h>
4#include <linux/module.h>
5#include <linux/mod_devicetable.h>
6#include <linux/slab.h>
7
8#include <asm/errno.h>
9#include <asm/of_device.h>
10
11/**
12 * of_match_node - Tell if an device_node has a matching of_match structure
13 * @ids: array of of device match structures to search in
14 * @node: the of device structure to match against
15 *
16 * Low level utility function used by device matching.
17 */
18const struct of_device_id *of_match_node(const struct of_device_id *matches,
19					 const struct device_node *node)
20{
21	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
22		int match = 1;
23		if (matches->name[0])
24			match &= node->name
25				&& !strcmp(matches->name, node->name);
26		if (matches->type[0])
27			match &= node->type
28				&& !strcmp(matches->type, node->type);
29		if (matches->compatible[0])
30			match &= of_device_is_compatible(node,
31						      matches->compatible);
32		if (match)
33			return matches;
34		matches++;
35	}
36	return NULL;
37}
38
39/**
40 * of_match_device - Tell if an of_device structure has a matching
41 * of_match structure
42 * @ids: array of of device match structures to search in
43 * @dev: the of device structure to match against
44 *
45 * Used by a driver to check whether an of_device present in the
46 * system is in its list of supported devices.
47 */
48const struct of_device_id *of_match_device(const struct of_device_id *matches,
49					const struct of_device *dev)
50{
51	if (!dev->node)
52		return NULL;
53	return of_match_node(matches, dev->node);
54}
55
56struct of_device *of_dev_get(struct of_device *dev)
57{
58	struct device *tmp;
59
60	if (!dev)
61		return NULL;
62	tmp = get_device(&dev->dev);
63	if (tmp)
64		return to_of_device(tmp);
65	else
66		return NULL;
67}
68
69void of_dev_put(struct of_device *dev)
70{
71	if (dev)
72		put_device(&dev->dev);
73}
74
75static ssize_t dev_show_devspec(struct device *dev,
76				struct device_attribute *attr, char *buf)
77{
78	struct of_device *ofdev;
79
80	ofdev = to_of_device(dev);
81	return sprintf(buf, "%s", ofdev->node->full_name);
82}
83
84static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
85
86/**
87 * of_release_dev - free an of device structure when all users of it are finished.
88 * @dev: device that's been disconnected
89 *
90 * Will be called only by the device core when all users of this of device are
91 * done.
92 */
93void of_release_dev(struct device *dev)
94{
95	struct of_device *ofdev;
96
97        ofdev = to_of_device(dev);
98	of_node_put(ofdev->node);
99	kfree(ofdev);
100}
101
102int of_device_register(struct of_device *ofdev)
103{
104	int rc;
105
106	BUG_ON(ofdev->node == NULL);
107
108	rc = device_register(&ofdev->dev);
109	if (rc)
110		return rc;
111
112	return device_create_file(&ofdev->dev, &dev_attr_devspec);
113}
114
115void of_device_unregister(struct of_device *ofdev)
116{
117	device_remove_file(&ofdev->dev, &dev_attr_devspec);
118
119	device_unregister(&ofdev->dev);
120}
121
122
123ssize_t of_device_get_modalias(struct of_device *ofdev,
124				char *str, ssize_t len)
125{
126	const char *compat;
127	int cplen, i;
128	ssize_t tsize, csize, repend;
129
130	/* Name & Type */
131	csize = snprintf(str, len, "of:N%sT%s",
132				ofdev->node->name, ofdev->node->type);
133
134	/* Get compatible property if any */
135	compat = of_get_property(ofdev->node, "compatible", &cplen);
136	if (!compat)
137		return csize;
138
139	/* Find true end (we tolerate multiple \0 at the end */
140	for (i=(cplen-1); i>=0 && !compat[i]; i--)
141		cplen--;
142	if (!cplen)
143		return csize;
144	cplen++;
145
146	/* Check space (need cplen+1 chars including final \0) */
147	tsize = csize + cplen;
148	repend = tsize;
149
150	if (csize>=len)		/* @ the limit, all is already filled */
151		return tsize;
152
153	if (tsize>=len) {		/* limit compat list */
154		cplen = len-csize-1;
155		repend = len;
156	}
157
158	/* Copy and do char replacement */
159	memcpy(&str[csize+1], compat, cplen);
160	for (i=csize; i<repend; i++) {
161		char c = str[i];
162		if (c=='\0')
163			str[i] = 'C';
164		else if (c==' ')
165			str[i] = '_';
166	}
167
168	return tsize;
169}
170
171int of_device_uevent(struct device *dev,
172		char **envp, int num_envp, char *buffer, int buffer_size)
173{
174	struct of_device *ofdev;
175	const char *compat;
176	int i = 0, length = 0, seen = 0, cplen, sl;
177
178	if (!dev)
179		return -ENODEV;
180
181	ofdev = to_of_device(dev);
182
183	if (add_uevent_var(envp, num_envp, &i,
184			   buffer, buffer_size, &length,
185			   "OF_NAME=%s", ofdev->node->name))
186		return -ENOMEM;
187
188	if (add_uevent_var(envp, num_envp, &i,
189			   buffer, buffer_size, &length,
190			   "OF_TYPE=%s", ofdev->node->type))
191		return -ENOMEM;
192
193        /* Since the compatible field can contain pretty much anything
194         * it's not really legal to split it out with commas. We split it
195         * up using a number of environment variables instead. */
196
197	compat = of_get_property(ofdev->node, "compatible", &cplen);
198	while (compat && *compat && cplen > 0) {
199		if (add_uevent_var(envp, num_envp, &i,
200				   buffer, buffer_size, &length,
201				   "OF_COMPATIBLE_%d=%s", seen, compat))
202			return -ENOMEM;
203
204		sl = strlen (compat) + 1;
205		compat += sl;
206		cplen -= sl;
207		seen++;
208	}
209
210	if (add_uevent_var(envp, num_envp, &i,
211			   buffer, buffer_size, &length,
212			   "OF_COMPATIBLE_N=%d", seen))
213		return -ENOMEM;
214
215	/* modalias is trickier, we add it in 2 steps */
216	if (add_uevent_var(envp, num_envp, &i,
217			   buffer, buffer_size, &length,
218			   "MODALIAS="))
219		return -ENOMEM;
220
221	sl = of_device_get_modalias(ofdev, &buffer[length-1],
222					buffer_size-length);
223	if (sl >= (buffer_size-length))
224		return -ENOMEM;
225
226	length += sl;
227
228	envp[i] = NULL;
229
230	return 0;
231}
232
233
234EXPORT_SYMBOL(of_match_node);
235EXPORT_SYMBOL(of_match_device);
236EXPORT_SYMBOL(of_device_register);
237EXPORT_SYMBOL(of_device_unregister);
238EXPORT_SYMBOL(of_dev_get);
239EXPORT_SYMBOL(of_dev_put);
240EXPORT_SYMBOL(of_release_dev);
241EXPORT_SYMBOL(of_device_uevent);
242EXPORT_SYMBOL(of_device_get_modalias);
243