@@ -65,10 +65,10 @@ static struct devfreq *find_device_devfreq(struct device *dev)
 
 /**
  * get_devfreq() - find devfreq struct. a wrapped find_device_devfreq()
- *		with mutex protection.
+ *		with mutex protection. exported for governors
  * @dev:	device pointer used to lookup device devfreq.
  */
-static struct devfreq *get_devfreq(struct device *dev)
+struct devfreq *get_devfreq(struct device *dev)
 {
 	struct devfreq *ret;
 

@@ -113,17 +113,15 @@ static int devfreq_do(struct devfreq *devfreq)
 }
 
 /**
- * devfreq_update() - Notify that the device OPP has been changed.
- * @dev:	the device whose OPP has been changed.
+ * update_devfreq() - Notify that the device OPP or frequency requirement
+ *		has been changed. This function is exported for governors.
+ * @devfreq:	the devfreq instance.
  */
-static int devfreq_update(struct notifier_block *nb, unsigned long type,
-			  void *devp)
+int update_devfreq(struct devfreq *devfreq)
 {
-	struct devfreq *devfreq;
 	int err = 0;
 
 	mutex_lock(&devfreq_list_lock);
-	devfreq = container_of(nb, struct devfreq, nb);
 	/* Reevaluate the proper frequency */
 	err = devfreq_do(devfreq);
 	mutex_unlock(&devfreq_list_lock);

@@ -131,6 +129,18 @@ static int devfreq_update(struct notifier_block *nb, unsigned long type,
 }
 
 /**
+ * devfreq_update() - Notify that the device OPP has been changed.
+ * @dev:	the device whose OPP has been changed.
+ */
+static int devfreq_update(struct notifier_block *nb, unsigned long type,
+			  void *devp)
+{
+	struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
+
+	return update_devfreq(devfreq);
+}
+
+/**
  * devfreq_monitor() - Periodically run devfreq_do()
  * @work: the work struct used to run devfreq_monitor periodically.
  *

@@ -254,6 +264,9 @@ int devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile,
 
 	list_add(&devfreq->node, &devfreq_list);
 
+	if (governor->init)
+		governor->init(devfreq);
+
 	if (devfreq_wq && devfreq->next_polling && !polling) {
 		polling = true;
 		queue_delayed_work(devfreq_wq, &devfreq_work,

@@ -295,6 +308,9 @@ int devfreq_remove_device(struct device *dev)
 
 	sysfs_unmerge_group(&dev->kobj, &dev_attr_group);
 
+	if (devfreq->governor->exit)
+		devfreq->governor->exit(devfreq);
+
 	list_del(&devfreq->node);
 	srcu_notifier_chain_unregister(nh, &devfreq->nb);
 	kfree(devfreq);

@@ -0,0 +1,20 @@
+/*
+ * governor.h - internal header for governors.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This header is for devfreq governors in drivers/devfreq/
+ */
+
+#ifndef _GOVERNOR_H
+#define _GOVERNOR_H
+
+extern struct devfreq *get_devfreq(struct device *dev);
+extern int update_devfreq(struct devfreq *devfreq);
+
+#endif /* _GOVERNOR_H */

@@ -46,6 +46,8 @@ struct devfreq_dev_profile {
 struct devfreq_governor {
 	char name[DEVFREQ_NAME_LEN];
 	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
+	int (*init)(struct devfreq *this);
+	void (*exit)(struct devfreq *this);
 };
 
 /**