drivers/of/device.c

   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);