xref: /openbmc/linux/drivers/of/device.c (revision 9d749629)
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 	/* Name & Type */
89 	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
90 			 dev->of_node->type);
91 
92 	/* Get compatible property if any */
93 	compat = of_get_property(dev->of_node, "compatible", &cplen);
94 	if (!compat)
95 		return csize;
96 
97 	/* Find true end (we tolerate multiple \0 at the end */
98 	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
99 		cplen--;
100 	if (!cplen)
101 		return csize;
102 	cplen++;
103 
104 	/* Check space (need cplen+1 chars including final \0) */
105 	tsize = csize + cplen;
106 	repend = tsize;
107 
108 	if (csize >= len)		/* @ the limit, all is already filled */
109 		return tsize;
110 
111 	if (tsize >= len) {		/* limit compat list */
112 		cplen = len - csize - 1;
113 		repend = len;
114 	}
115 
116 	/* Copy and do char replacement */
117 	memcpy(&str[csize + 1], compat, cplen);
118 	for (i = csize; i < repend; i++) {
119 		char c = str[i];
120 		if (c == '\0')
121 			str[i] = 'C';
122 		else if (c == ' ')
123 			str[i] = '_';
124 	}
125 
126 	return tsize;
127 }
128 
129 /**
130  * of_device_uevent - Display OF related uevent information
131  */
132 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
133 {
134 	const char *compat;
135 	struct alias_prop *app;
136 	int seen = 0, cplen, sl;
137 
138 	if ((!dev) || (!dev->of_node))
139 		return;
140 
141 	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
142 	add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
143 	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
144 		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
145 
146 	/* Since the compatible field can contain pretty much anything
147 	 * it's not really legal to split it out with commas. We split it
148 	 * up using a number of environment variables instead. */
149 	compat = of_get_property(dev->of_node, "compatible", &cplen);
150 	while (compat && *compat && cplen > 0) {
151 		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
152 		sl = strlen(compat) + 1;
153 		compat += sl;
154 		cplen -= sl;
155 		seen++;
156 	}
157 	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
158 
159 	seen = 0;
160 	mutex_lock(&of_aliases_mutex);
161 	list_for_each_entry(app, &aliases_lookup, link) {
162 		if (dev->of_node == app->np) {
163 			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
164 				       app->alias);
165 			seen++;
166 		}
167 	}
168 	mutex_unlock(&of_aliases_mutex);
169 }
170 
171 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
172 {
173 	int sl;
174 
175 	if ((!dev) || (!dev->of_node))
176 		return -ENODEV;
177 
178 	/* Devicetree modalias is tricky, we add it in 2 steps */
179 	if (add_uevent_var(env, "MODALIAS="))
180 		return -ENOMEM;
181 
182 	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
183 				    sizeof(env->buf) - env->buflen);
184 	if (sl >= (sizeof(env->buf) - env->buflen))
185 		return -ENOMEM;
186 	env->buflen += sl;
187 
188 	return 0;
189 }
190