xref: /linux/drivers/of/device.c (revision 140b932f8cb6cced10b96860651a198b1b89cbb9)
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 an of_device structure has a matching
14  * of_match structure
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 of_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 of_device *dev)
23 {
24 	if (!dev->node)
25 		return NULL;
26 	return of_match_node(matches, dev->node);
27 }
28 EXPORT_SYMBOL(of_match_device);
29 
30 struct of_device *of_dev_get(struct of_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_of_device(tmp);
39 	else
40 		return NULL;
41 }
42 EXPORT_SYMBOL(of_dev_get);
43 
44 void of_dev_put(struct of_device *dev)
45 {
46 	if (dev)
47 		put_device(&dev->dev);
48 }
49 EXPORT_SYMBOL(of_dev_put);
50 
51 static ssize_t devspec_show(struct device *dev,
52 				struct device_attribute *attr, char *buf)
53 {
54 	struct of_device *ofdev;
55 
56 	ofdev = to_of_device(dev);
57 	return sprintf(buf, "%s\n", ofdev->node->full_name);
58 }
59 
60 static ssize_t modalias_show(struct device *dev,
61 				struct device_attribute *attr, char *buf)
62 {
63 	struct of_device *ofdev = to_of_device(dev);
64 	ssize_t len = 0;
65 
66 	len = of_device_get_modalias(ofdev, buf, PAGE_SIZE - 2);
67 	buf[len] = '\n';
68 	buf[len+1] = 0;
69 	return len+1;
70 }
71 
72 struct device_attribute of_platform_device_attrs[] = {
73 	__ATTR_RO(devspec),
74 	__ATTR_RO(modalias),
75 	__ATTR_NULL
76 };
77 
78 /**
79  * of_release_dev - free an of device structure when all users of it are finished.
80  * @dev: device that's been disconnected
81  *
82  * Will be called only by the device core when all users of this of device are
83  * done.
84  */
85 void of_release_dev(struct device *dev)
86 {
87 	struct of_device *ofdev;
88 
89 	ofdev = to_of_device(dev);
90 	of_node_put(ofdev->node);
91 	kfree(ofdev);
92 }
93 EXPORT_SYMBOL(of_release_dev);
94 
95 int of_device_register(struct of_device *ofdev)
96 {
97 	BUG_ON(ofdev->node == NULL);
98 	return device_register(&ofdev->dev);
99 }
100 EXPORT_SYMBOL(of_device_register);
101 
102 void of_device_unregister(struct of_device *ofdev)
103 {
104 	device_unregister(&ofdev->dev);
105 }
106 EXPORT_SYMBOL(of_device_unregister);
107