summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/of_device.c
blob: e8aa1f3675b7df719a1c081a3eb532f0b46d51d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>

#include <asm/errno.h>
#include <asm/of_device.h>

/**
 * of_match_node - Tell if an device_node has a matching of_match structure
 * @ids: array of of device match structures to search in
 * @node: the of device structure to match against
 *
 * Low level utility function used by device matching.
 */
const struct of_device_id *of_match_node(const struct of_device_id *matches,
					 const struct device_node *node)
{
	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
		int match = 1;
		if (matches->name[0])
			match &= node->name
				&& !strcmp(matches->name, node->name);
		if (matches->type[0])
			match &= node->type
				&& !strcmp(matches->type, node->type);
		if (matches->compatible[0])
			match &= device_is_compatible(node,
						      matches->compatible);
		if (match)
			return matches;
		matches++;
	}
	return NULL;
}

/**
 * of_match_device - Tell if an of_device structure has a matching
 * of_match structure
 * @ids: array of of device match structures to search in
 * @dev: the of device structure to match against
 *
 * Used by a driver to check whether an of_device present in the
 * system is in its list of supported devices.
 */
const struct of_device_id *of_match_device(const struct of_device_id *matches,
					const struct of_device *dev)
{
	if (!dev->node)
		return NULL;
	return of_match_node(matches, dev->node);
}

struct of_device *of_dev_get(struct of_device *dev)
{
	struct device *tmp;

	if (!dev)
		return NULL;
	tmp = get_device(&dev->dev);
	if (tmp)
		return to_of_device(tmp);
	else
		return NULL;
}

void of_dev_put(struct of_device *dev)
{
	if (dev)
		put_device(&dev->dev);
}

static ssize_t dev_show_devspec(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct of_device *ofdev;

	ofdev = to_of_device(dev);
	return sprintf(buf, "%s", ofdev->node->full_name);
}

static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);

/**
 * of_release_dev - free an of device structure when all users of it are finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this of device are
 * done.
 */
void of_release_dev(struct device *dev)
{
	struct of_device *ofdev;

        ofdev = to_of_device(dev);
	of_node_put(ofdev->node);
	kfree(ofdev);
}

int of_device_register(struct of_device *ofdev)
{
	int rc;

	BUG_ON(ofdev->node == NULL);

	rc = device_register(&ofdev->dev);
	if (rc)
		return rc;

	return device_create_file(&ofdev->dev, &dev_attr_devspec);
}

void of_device_unregister(struct of_device *ofdev)
{
	device_remove_file(&ofdev->dev, &dev_attr_devspec);

	device_unregister(&ofdev->dev);
}


static ssize_t of_device_get_modalias(struct of_device *ofdev,
					char *str, ssize_t len)
{
	const char *compat;
	int cplen, i;
	ssize_t tsize, csize, repend;

	/* Name & Type */
	csize = snprintf(str, len, "of:N%sT%s",
				ofdev->node->name, ofdev->node->type);

	/* Get compatible property if any */
	compat = get_property(ofdev->node, "compatible", &cplen);
	if (!compat)
		return csize;

	/* Find true end (we tolerate multiple \0 at the end */
	for (i=(cplen-1); i>=0 && !compat[i]; i--)
		cplen--;
	if (!cplen)
		return csize;
	cplen++;

	/* Check space (need cplen+1 chars including final \0) */
	tsize = csize + cplen;
	repend = tsize;

	if (csize>=len)		/* @ the limit, all is already filled */
		return tsize;

	if (tsize>=len) {		/* limit compat list */
		cplen = len-csize-1;
		repend = len;
	}

	/* Copy and do char replacement */
	memcpy(&str[csize+1], compat, cplen);
	for (i=csize; i<repend; i++) {
		char c = str[i];
		if (c=='\0')
			str[i] = 'C';
		else if (c==' ')
			str[i] = '_';
	}

	return tsize;
}

int of_device_uevent(struct device *dev,
		char **envp, int num_envp, char *buffer, int buffer_size)
{
	struct of_device *ofdev;
	const char *compat;
	int i = 0, length = 0, seen = 0, cplen, sl;

	if (!dev)
		return -ENODEV;

	ofdev = to_of_device(dev);

	if (add_uevent_var(envp, num_envp, &i,
			   buffer, buffer_size, &length,
			   "OF_NAME=%s", ofdev->node->name))
		return -ENOMEM;

	if (add_uevent_var(envp, num_envp, &i,
			   buffer, buffer_size, &length,
			   "OF_TYPE=%s", ofdev->node->type))
		return -ENOMEM;

        /* Since the compatible field can contain pretty much anything
         * it's not really legal to split it out with commas. We split it
         * up using a number of environment variables instead. */

	compat = get_property(ofdev->node, "compatible", &cplen);
	while (compat && *compat && cplen > 0) {
		if (add_uevent_var(envp, num_envp, &i,
				   buffer, buffer_size, &length,
				   "OF_COMPATIBLE_%d=%s", seen, compat))
			return -ENOMEM;

		sl = strlen (compat) + 1;
		compat += sl;
		cplen -= sl;
		seen++;
	}

	if (add_uevent_var(envp, num_envp, &i,
			   buffer, buffer_size, &length,
			   "OF_COMPATIBLE_N=%d", seen))
		return -ENOMEM;

	/* modalias is trickier, we add it in 2 steps */
	if (add_uevent_var(envp, num_envp, &i,
			   buffer, buffer_size, &length,
			   "MODALIAS="))
		return -ENOMEM;

	sl = of_device_get_modalias(ofdev, &buffer[length-1],
					buffer_size-length);
	if (sl >= (buffer_size-length))
		return -ENOMEM;

	length += sl;

	envp[i] = NULL;

	return 0;
}


EXPORT_SYMBOL(of_match_node);
EXPORT_SYMBOL(of_match_device);
EXPORT_SYMBOL(of_device_register);
EXPORT_SYMBOL(of_device_unregister);
EXPORT_SYMBOL(of_dev_get);
EXPORT_SYMBOL(of_dev_put);
EXPORT_SYMBOL(of_release_dev);
EXPORT_SYMBOL(of_device_uevent);