Re: [PATCH v8 4/5] PM / DEVFREQ: add internal interfaces for governors

---
 drivers/devfreq/devfreq.c  |   32 ++++++++++++++++++++++++--------
 drivers/devfreq/governor.h |   20 ++++++++++++++++++++
 include/linux/devfreq.h    |    2 ++
 3 files changed, 46 insertions(+), 8 deletions(-)
 create mode 100644 drivers/devfreq/governor.h

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 5bbece6..8de3b21 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c

@@ -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);

diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
new file mode 100644
index 0000000..bb5d964
--- /dev/null
+++ b/drivers/devfreq/governor.h

@@ -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 */

diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 8252238..fdc6916 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.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);
 };

 /**
--
1.7.4.1