xref: /openbmc/linux/drivers/of/device.c (revision c21b37f6)
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_node - Tell if an device_node has a matching of_match structure
14  * @ids: array of of device match structures to search in
15  * @node: the of device structure to match against
16  *
17  * Low level utility function used by device matching.
18  */
19 const struct of_device_id *of_match_node(const struct of_device_id *matches,
20 					 const struct device_node *node)
21 {
22 	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
23 		int match = 1;
24 		if (matches->name[0])
25 			match &= node->name
26 				&& !strcmp(matches->name, node->name);
27 		if (matches->type[0])
28 			match &= node->type
29 				&& !strcmp(matches->type, node->type);
30 		if (matches->compatible[0])
31 			match &= of_device_is_compatible(node,
32 						matches->compatible);
33 		if (match)
34 			return matches;
35 		matches++;
36 	}
37 	return NULL;
38 }
39 EXPORT_SYMBOL(of_match_node);
40 
41 /**
42  * of_match_device - Tell if an of_device structure has a matching
43  * of_match structure
44  * @ids: array of of device match structures to search in
45  * @dev: the of device structure to match against
46  *
47  * Used by a driver to check whether an of_device present in the
48  * system is in its list of supported devices.
49  */
50 const struct of_device_id *of_match_device(const struct of_device_id *matches,
51 					const struct of_device *dev)
52 {
53 	if (!dev->node)
54 		return NULL;
55 	return of_match_node(matches, dev->node);
56 }
57 EXPORT_SYMBOL(of_match_device);
58 
59 struct of_device *of_dev_get(struct of_device *dev)
60 {
61 	struct device *tmp;
62 
63 	if (!dev)
64 		return NULL;
65 	tmp = get_device(&dev->dev);
66 	if (tmp)
67 		return to_of_device(tmp);
68 	else
69 		return NULL;
70 }
71 EXPORT_SYMBOL(of_dev_get);
72 
73 void of_dev_put(struct of_device *dev)
74 {
75 	if (dev)
76 		put_device(&dev->dev);
77 }
78 EXPORT_SYMBOL(of_dev_put);
79 
80 static ssize_t dev_show_devspec(struct device *dev,
81 				struct device_attribute *attr, char *buf)
82 {
83 	struct of_device *ofdev;
84 
85 	ofdev = to_of_device(dev);
86 	return sprintf(buf, "%s", ofdev->node->full_name);
87 }
88 
89 static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
90 
91 /**
92  * of_release_dev - free an of device structure when all users of it are finished.
93  * @dev: device that's been disconnected
94  *
95  * Will be called only by the device core when all users of this of device are
96  * done.
97  */
98 void of_release_dev(struct device *dev)
99 {
100 	struct of_device *ofdev;
101 
102 	ofdev = to_of_device(dev);
103 	of_node_put(ofdev->node);
104 	kfree(ofdev);
105 }
106 EXPORT_SYMBOL(of_release_dev);
107 
108 int of_device_register(struct of_device *ofdev)
109 {
110 	int rc;
111 
112 	BUG_ON(ofdev->node == NULL);
113 
114 	rc = device_register(&ofdev->dev);
115 	if (rc)
116 		return rc;
117 
118 	rc = device_create_file(&ofdev->dev, &dev_attr_devspec);
119 	if (rc)
120 		device_unregister(&ofdev->dev);
121 
122 	return rc;
123 }
124 EXPORT_SYMBOL(of_device_register);
125 
126 void of_device_unregister(struct of_device *ofdev)
127 {
128 	device_remove_file(&ofdev->dev, &dev_attr_devspec);
129 	device_unregister(&ofdev->dev);
130 }
131 EXPORT_SYMBOL(of_device_unregister);
132