Driver Core: add class iteration api

Add the following class iteration functions for driver use:
	class_for_each_device
	class_find_device
	class_for_each_child
	class_find_child

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 92ba3a874627..cdaf57bf4d19 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -177,8 +177,7 @@ struct class {
         struct list_head        devices;
         struct list_head        interfaces;
         struct kset             class_dirs;
-        struct semaphore        sem;    /* locks both the children and interfaces lists */
-
+        struct semaphore        sem; /* locks children, devices, interfaces */
         struct class_attribute          * class_attrs;
         struct class_device_attribute   * class_dev_attrs;
         struct device_attribute         * dev_attrs;
@@ -196,6 +195,12 @@ struct class {
 
 extern int __must_check class_register(struct class *);
 extern void class_unregister(struct class *);
+extern int class_for_each_device(struct class *class, void *data,
+                                 int (*fn)(struct device *dev, void *data));
+extern struct device *class_find_device(struct class *class, void *data,
+                                        int (*match)(struct device *, void *));
+extern struct class_device *class_find_child(struct class *class, void *data,
+                                   int (*match)(struct class_device *, void *));
 
 
 struct class_attribute {