xref: /openbmc/linux/drivers/of/device.c (revision afc98d90)
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 #include "of_private.h"
12 
13 /**
14  * of_match_device - Tell if a struct device matches an of_device_id list
15  * @ids: array of of device match structures to search in
16  * @dev: the of device structure to match against
17  *
18  * Used by a driver to check whether an platform_device present in the
19  * system is in its list of supported devices.
20  */
21 const struct of_device_id *of_match_device(const struct of_device_id *matches,
22 					   const struct device *dev)
23 {
24 	if ((!matches) || (!dev->of_node))
25 		return NULL;
26 	return of_match_node(matches, dev->of_node);
27 }
28 EXPORT_SYMBOL(of_match_device);
29 
30 struct platform_device *of_dev_get(struct platform_device *dev)
31 {
32 	struct device *tmp;
33 
34 	if (!dev)
35 		return NULL;
36 	tmp = get_device(&dev->dev);
37 	if (tmp)
38 		return to_platform_device(tmp);
39 	else
40 		return NULL;
41 }
42 EXPORT_SYMBOL(of_dev_get);
43 
44 void of_dev_put(struct platform_device *dev)
45 {
46 	if (dev)
47 		put_device(&dev->dev);
48 }
49 EXPORT_SYMBOL(of_dev_put);
50 
51 int of_device_add(struct platform_device *ofdev)
52 {
53 	BUG_ON(ofdev->dev.of_node == NULL);
54 
55 	/* name and id have to be set so that the platform bus doesn't get
56 	 * confused on matching */
57 	ofdev->name = dev_name(&ofdev->dev);
58 	ofdev->id = -1;
59 
60 	/* device_add will assume that this device is on the same node as
61 	 * the parent. If there is no parent defined, set the node
62 	 * explicitly */
63 	if (!ofdev->dev.parent)
64 		set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
65 
66 	return device_add(&ofdev->dev);
67 }
68 
69 int of_device_register(struct platform_device *pdev)
70 {
71 	device_initialize(&pdev->dev);
72 	return of_device_add(pdev);
73 }
74 EXPORT_SYMBOL(of_device_register);
75 
76 void of_device_unregister(struct platform_device *ofdev)
77 {
78 	device_unregister(&ofdev->dev);
79 }
80 EXPORT_SYMBOL(of_device_unregister);
81 
82 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
83 {
84 	const char *compat;
85 	int cplen, i;
86 	ssize_t tsize, csize, repend;
87 
88 	if ((!dev) || (!dev->of_node))
89 		return -ENODEV;
90 
91 	/* Name & Type */
92 	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
93 			 dev->of_node->type);
94 
95 	/* Get compatible property if any */
96 	compat = of_get_property(dev->of_node, "compatible", &cplen);
97 	if (!compat)
98 		return csize;
99 
100 	/* Find true end (we tolerate multiple \0 at the end */
101 	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
102 		cplen--;
103 	if (!cplen)
104 		return csize;
105 	cplen++;
106 
107 	/* Check space (need cplen+1 chars including final \0) */
108 	tsize = csize + cplen;
109 	repend = tsize;
110 
111 	if (csize >= len)		/* @ the limit, all is already filled */
112 		return tsize;
113 
114 	if (tsize >= len) {		/* limit compat list */
115 		cplen = len - csize - 1;
116 		repend = len;
117 	}
118 
119 	/* Copy and do char replacement */
120 	memcpy(&str[csize + 1], compat, cplen);
121 	for (i = csize; i < repend; i++) {
122 		char c = str[i];
123 		if (c == '\0')
124 			str[i] = 'C';
125 		else if (c == ' ')
126 			str[i] = '_';
127 	}
128 
129 	return tsize;
130 }
131 
132 /**
133  * of_device_uevent - Display OF related uevent information
134  */
135 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
136 {
137 	const char *compat;
138 	struct alias_prop *app;
139 	int seen = 0, cplen, sl;
140 
141 	if ((!dev) || (!dev->of_node))
142 		return;
143 
144 	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
145 	add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
146 	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
147 		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
148 
149 	/* Since the compatible field can contain pretty much anything
150 	 * it's not really legal to split it out with commas. We split it
151 	 * up using a number of environment variables instead. */
152 	compat = of_get_property(dev->of_node, "compatible", &cplen);
153 	while (compat && *compat && cplen > 0) {
154 		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
155 		sl = strlen(compat) + 1;
156 		compat += sl;
157 		cplen -= sl;
158 		seen++;
159 	}
160 	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
161 
162 	seen = 0;
163 	mutex_lock(&of_aliases_mutex);
164 	list_for_each_entry(app, &aliases_lookup, link) {
165 		if (dev->of_node == app->np) {
166 			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
167 				       app->alias);
168 			seen++;
169 		}
170 	}
171 	mutex_unlock(&of_aliases_mutex);
172 }
173 
174 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
175 {
176 	int sl;
177 
178 	if ((!dev) || (!dev->of_node))
179 		return -ENODEV;
180 
181 	/* Devicetree modalias is tricky, we add it in 2 steps */
182 	if (add_uevent_var(env, "MODALIAS="))
183 		return -ENOMEM;
184 
185 	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
186 				    sizeof(env->buf) - env->buflen);
187 	if (sl >= (sizeof(env->buf) - env->buflen))
188 		return -ENOMEM;
189 	env->buflen += sl;
190 
191 	return 0;
192 }
193