xref: /openbmc/linux/drivers/of/device.c (revision a1e58bbd)
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 dev_show_devspec(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", ofdev->node->full_name);
58 }
59 
60 static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
61 
62 /**
63  * of_release_dev - free an of device structure when all users of it are finished.
64  * @dev: device that's been disconnected
65  *
66  * Will be called only by the device core when all users of this of device are
67  * done.
68  */
69 void of_release_dev(struct device *dev)
70 {
71 	struct of_device *ofdev;
72 
73 	ofdev = to_of_device(dev);
74 	of_node_put(ofdev->node);
75 	kfree(ofdev);
76 }
77 EXPORT_SYMBOL(of_release_dev);
78 
79 int of_device_register(struct of_device *ofdev)
80 {
81 	int rc;
82 
83 	BUG_ON(ofdev->node == NULL);
84 
85 	rc = device_register(&ofdev->dev);
86 	if (rc)
87 		return rc;
88 
89 	rc = device_create_file(&ofdev->dev, &dev_attr_devspec);
90 	if (rc)
91 		device_unregister(&ofdev->dev);
92 
93 	return rc;
94 }
95 EXPORT_SYMBOL(of_device_register);
96 
97 void of_device_unregister(struct of_device *ofdev)
98 {
99 	device_remove_file(&ofdev->dev, &dev_attr_devspec);
100 	device_unregister(&ofdev->dev);
101 }
102 EXPORT_SYMBOL(of_device_unregister);
103