driver model: change class reference counting to be like devices'.

device classes join the club of devices, buses, and drivers. They get a 
->present flag, which is set on registration and cleared on unregistration.
They also get get_devclass() and put_devclass(), which, you guessed it, 
bump the reference count. get_...() of course checks the present flag and
returns NULL if clear. 

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 4b6b0cbe77ed..112fca2dd2d8 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -163,6 +163,9 @@ extern void driver_remove_file(struct device_driver *, struct driver_attribute *
  */
 struct device_class {
 	char			* name;
+	atomic_t		refcount;
+	u32			present;
+
 	u32			devnum;
 
 	struct list_head	node;
@@ -180,6 +183,9 @@ struct device_class {
 extern int devclass_register(struct device_class *);
 extern void devclass_unregister(struct device_class *);
 
+extern struct device_class * get_devclass(struct device_class *);
+extern void put_devclass(struct device_class *);
+
 
 struct devclass_attribute {
 	struct attribute	attr;