drver model: Add release method for class devices.

From Manuel Estrada Sainz <ranty@debian.org>

So device classes can intercept the generic object release method.

drivers/base/base.h

@@ -4,3 +4,12 @@ extern void bus_remove_device(struct device * dev);
 extern int bus_add_driver(struct device_driver *);
 extern void bus_remove_driver(struct device_driver *);
 
+static inline struct class_device *to_class_dev(struct kobject *obj)
+{
+	return container_of(obj,struct class_device,kobj);
+}
+static inline
+struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
+{
+	return container_of(_attr,struct class_device_attribute,attr);
+}

drivers/base/class.c

@@ -148,9 +148,6 @@ static void class_device_driver_unlink(struct class_device * class_dev)
 }
 
 
-#define to_class_dev(obj) container_of(obj,struct class_device,kobj)
-#define to_class_dev_attr(_attr) container_of(_attr,struct class_device_attribute,attr)
-
 static ssize_t
 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 		       char * buf)
@@ -182,7 +179,15 @@ static struct sysfs_ops class_dev_sysfs_ops = {
 	.store	= class_device_attr_store,
 };
 
+static void class_dev_release(struct kobject * kobj)
+{
+	struct class_device *class_dev = to_class_dev(kobj);
+	if (class_dev->release)
+		class_dev->release(class_dev);
+}
+
 static struct kobj_type ktype_class_device = {
+	.release	= &class_dev_release,
 	.sysfs_ops	= &class_dev_sysfs_ops,
 };
 

include/linux/device.h

@@ -204,6 +204,7 @@ struct class_device {
 	void			* class_data;	/* class-specific data */
 
 	char	class_id[BUS_ID_SIZE];	/* unique to this class */
+	void	(*release)(struct class_device * class_dev);
 };
 
 static inline void *