xref: /openbmc/linux/drivers/of/device.c (revision 95e9fd10)
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  */
20 const 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 }
27 EXPORT_SYMBOL(of_match_device);
28 
29 struct 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 }
41 EXPORT_SYMBOL(of_dev_get);
42 
43 void of_dev_put(struct platform_device *dev)
44 {
45 	if (dev)
46 		put_device(&dev->dev);
47 }
48 EXPORT_SYMBOL(of_dev_put);
49 
50 int of_device_add(struct platform_device *ofdev)
51 {
52 	BUG_ON(ofdev->dev.of_node == NULL);
53 
54 	/* name and id have to be set so that the platform bus doesn't get
55 	 * confused on matching */
56 	ofdev->name = dev_name(&ofdev->dev);
57 	ofdev->id = -1;
58 
59 	/* device_add will assume that this device is on the same node as
60 	 * the parent. If there is no parent defined, set the node
61 	 * explicitly */
62 	if (!ofdev->dev.parent)
63 		set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
64 
65 	return device_add(&ofdev->dev);
66 }
67 
68 int of_device_register(struct platform_device *pdev)
69 {
70 	device_initialize(&pdev->dev);
71 	return of_device_add(pdev);
72 }
73 EXPORT_SYMBOL(of_device_register);
74 
75 void of_device_unregister(struct platform_device *ofdev)
76 {
77 	device_unregister(&ofdev->dev);
78 }
79 EXPORT_SYMBOL(of_device_unregister);
80 
81 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
82 {
83 	const char *compat;
84 	int cplen, i;
85 	ssize_t tsize, csize, repend;
86 
87 	/* Name & Type */
88 	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
89 			 dev->of_node->type);
90 
91 	/* Get compatible property if any */
92 	compat = of_get_property(dev->of_node, "compatible", &cplen);
93 	if (!compat)
94 		return csize;
95 
96 	/* Find true end (we tolerate multiple \0 at the end */
97 	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
98 		cplen--;
99 	if (!cplen)
100 		return csize;
101 	cplen++;
102 
103 	/* Check space (need cplen+1 chars including final \0) */
104 	tsize = csize + cplen;
105 	repend = tsize;
106 
107 	if (csize >= len)		/* @ the limit, all is already filled */
108 		return tsize;
109 
110 	if (tsize >= len) {		/* limit compat list */
111 		cplen = len - csize - 1;
112 		repend = len;
113 	}
114 
115 	/* Copy and do char replacement */
116 	memcpy(&str[csize + 1], compat, cplen);
117 	for (i = csize; i < repend; i++) {
118 		char c = str[i];
119 		if (c == '\0')
120 			str[i] = 'C';
121 		else if (c == ' ')
122 			str[i] = '_';
123 	}
124 
125 	return tsize;
126 }
127 
128 /**
129  * of_device_uevent - Display OF related uevent information
130  */
131 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
132 {
133 	const char *compat;
134 	int seen = 0, cplen, sl;
135 
136 	if ((!dev) || (!dev->of_node))
137 		return;
138 
139 	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
140 	add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
141 	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
142 		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
143 
144 	/* Since the compatible field can contain pretty much anything
145 	 * it's not really legal to split it out with commas. We split it
146 	 * up using a number of environment variables instead. */
147 	compat = of_get_property(dev->of_node, "compatible", &cplen);
148 	while (compat && *compat && cplen > 0) {
149 		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
150 		sl = strlen(compat) + 1;
151 		compat += sl;
152 		cplen -= sl;
153 		seen++;
154 	}
155 	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
156 }
157 
158 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
159 {
160 	int sl;
161 
162 	if ((!dev) || (!dev->of_node))
163 		return -ENODEV;
164 
165 	/* Devicetree modalias is tricky, we add it in 2 steps */
166 	if (add_uevent_var(env, "MODALIAS="))
167 		return -ENOMEM;
168 
169 	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
170 				    sizeof(env->buf) - env->buflen);
171 	if (sl >= (sizeof(env->buf) - env->buflen))
172 		return -ENOMEM;
173 	env->buflen += sl;
174 
175 	return 0;
176 }
177