[PATCH 1/3] driver core: class: add class_groups support

[Greg Kroah-Hartman]

struct class needs to have a set of default groups that are added, as
adding individual attributes does not work well in the long run.  So add
support for that.

Future patches will convert the existing usages of class_attrs to use
class_groups and then class_attrs will go away.

Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/base/class.c   | 15 +++++++++++++++
 include/linux/device.h |  2 ++
 2 files changed, 17 insertions(+)

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 71059e32bebc..a2b2896693d6 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -163,6 +163,18 @@ static void klist_class_dev_put(struct klist_node *n)
 	put_device(dev);
 }
 
+static int class_add_groups(struct class *cls,
+			    const struct attribute_group **groups)
+{
+	return sysfs_create_groups(&cls->p->subsys.kobj, groups);
+}
+
+static void class_remove_groups(struct class *cls,
+				const struct attribute_group **groups)
+{
+	return sysfs_remove_groups(&cls->p->subsys.kobj, groups);
+}
+
 int __class_register(struct class *cls, struct lock_class_key *key)
 {
 	struct subsys_private *cp;
@@ -203,6 +215,8 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 		kfree(cp);
 		return error;
 	}
+	error = class_add_groups(class_get(cls), cls->class_groups);
+	class_put(cls);
 	error = add_class_attrs(class_get(cls));
 	class_put(cls);
 	return error;
@@ -213,6 +227,7 @@ void class_unregister(struct class *cls)
 {
 	pr_debug("device class '%s': unregistering\n", cls->name);
 	remove_class_attrs(cls);
+	class_remove_groups(cls, cls->class_groups);
 	kset_unregister(&cls->p->subsys);
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
index bc41e87a969b..39d71c8a59f4 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -362,6 +362,7 @@ int subsys_virtual_register(struct bus_type *subsys,
  * @name:	Name of the class.
  * @owner:	The module owner.
  * @class_attrs: Default attributes of this class.
+ * @class_groups: Default attributes of this class.
  * @dev_groups:	Default attributes of the devices that belong to the class.
  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
  * @dev_uevent:	Called when a device is added, removed from this class, or a
@@ -390,6 +391,7 @@ struct class {
 	struct module		*owner;
 
 	struct class_attribute		*class_attrs;
+	const struct attribute_group	**class_groups;
 	const struct attribute_group	**dev_groups;
 	struct kobject			*dev_kobj;
 
-- 
2.10.2