[PATCH v2 1/2] PM/devfreq: add suspend frequency support

[Lin Huang]

Add suspend frequency support and if needed set it to
the frequency obtained from the suspend opp (can be defined
using opp-v2 bindings and is optional).

Change-Id: Iaa0d3848d63d9ce03f65ea76f263e4685a4c295e
Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
---
Changes in v2:
- use update_devfreq() instead devfreq_update_status()

 drivers/devfreq/devfreq.c | 17 ++++++++++++++++-
 include/linux/devfreq.h   |  9 +++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bf3ea76..0a76282 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -364,7 +364,10 @@ void devfreq_monitor_suspend(struct devfreq *devfreq)
 		return;
 	}
 
-	devfreq_update_status(devfreq, devfreq->previous_freq);
+	if (devfreq->suspend_freq)
+		update_devfreq(devfreq, devfreq->suspend_freq);
+	else
+		devfreq_update_status(devfreq, devfreq->previous_freq);
 	devfreq->stop_polling = true;
 	mutex_unlock(&devfreq->lock);
 	cancel_delayed_work_sync(&devfreq->work);
@@ -1251,6 +1254,18 @@ struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
 }
 EXPORT_SYMBOL(devfreq_recommended_opp);
 
+void devfreq_opp_get_suspend_opp(struct device *dev, struct devfreq *devfreq)
+{
+	struct dev_pm_opp *suspend_opp;
+
+	rcu_read_lock();
+	suspend_opp = dev_pm_opp_get_suspend_opp(dev);
+	if (suspend_opp)
+		devfreq->suspend_freq = dev_pm_opp_get_freq(suspend_opp);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(devfreq_opp_get_suspend_opp);
+
 /**
  * devfreq_register_opp_notifier() - Helper function to get devfreq notified
  *				   for any changes in the OPP availability
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 2de4e2e..c785ad9 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -88,6 +88,7 @@ struct devfreq_dev_status {
  */
 struct devfreq_dev_profile {
 	unsigned long initial_freq;
+	unsigned long suspend_freq;
 	unsigned int polling_ms;
 
 	int (*target)(struct device *dev, unsigned long *freq, u32 flags);
@@ -172,6 +173,7 @@ struct devfreq {
 	struct delayed_work work;
 
 	unsigned long previous_freq;
+	unsigned long suspend_freq;
 	struct devfreq_dev_status last_status;
 
 	void *data; /* private data for governors */
@@ -214,6 +216,8 @@ extern void devm_devfreq_remove_device(struct device *dev,
 /* Helper functions for devfreq user device driver with OPP. */
 extern struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
 					   unsigned long *freq, u32 flags);
+extern void devfreq_opp_get_suspend_opp(struct device *dev,
+					struct devfreq *devfreq);
 extern int devfreq_register_opp_notifier(struct device *dev,
 					 struct devfreq *devfreq);
 extern int devfreq_unregister_opp_notifier(struct device *dev,
@@ -348,6 +352,11 @@ static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
 	return ERR_PTR(-EINVAL);
 }
 
+static inline void devfreq_opp_get_suspend_opp(struct device *dev,
+					       struct devfreq *devfreq)
+{
+}
+
 static inline int devfreq_register_opp_notifier(struct device *dev,
 					 struct devfreq *devfreq)
 {
-- 
1.9.1