[patch 03/28] Driver core: allow nesting classes

[Dmitry Torokhov <dtor_core@ameritech.net>]

[-- Attachment #1: nested-classes.patch --]
[-- Type: text/plain, Size: 1720 bytes --]

Driver core: allow nesting classes

This will allow unclutter /sys/classes directory, combining
classes related to the same subsystem "under one roof".

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

 drivers/base/class.c   |    8 +++++++-
 include/linux/device.h |    1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

Index: work/drivers/base/class.c
===================================================================
--- work.orig/drivers/base/class.c
+++ work/drivers/base/class.c
@@ -135,6 +135,7 @@ static void remove_class_attrs(struct cl
 
 int class_register(struct class * cls)
 {
+	struct class *parent;
 	int error;
 
 	pr_debug("device class '%s': registering\n", cls->name);
@@ -146,7 +147,11 @@ int class_register(struct class * cls)
 	if (error)
 		return error;
 
-	subsys_set_kset(cls, class_subsys);
+	parent = class_get(cls->parent);
+	if (parent)
+		subsys_set_kset(cls, parent->subsys);
+	else
+		subsys_set_kset(cls, class_subsys);
 
 	error = subsystem_register(&cls->subsys);
 	if (!error) {
@@ -161,6 +166,7 @@ void class_unregister(struct class * cls
 	pr_debug("device class '%s': unregistering\n", cls->name);
 	remove_class_attrs(cls);
 	subsystem_unregister(&cls->subsys);
+	class_put(cls->parent);
 }
 
 static void class_create_release(struct class *cls)
Index: work/include/linux/device.h
===================================================================
--- work.orig/include/linux/device.h
+++ work/include/linux/device.h
@@ -157,6 +157,7 @@ struct class {
 	struct module		* owner;
 
 	struct subsystem	subsys;
+	struct class		* parent;
 	struct list_head	children;
 	struct list_head	interfaces;
 	struct semaphore	sem;	/* locks both the children and interfaces lists */