[PATCH 2/3] devfreq: Add suspend and resume apis

[Rajagopal Venkat]

Add devfreq suspend/resume apis for devfreq users. This patch
supports suspend and resume of devfreq load monitoring, required
for devices which can idle.

Signed-off-by: Rajagopal Venkat <rajagopal.venkat@xxxxxxxxxx>
---
 drivers/devfreq/devfreq.c                 | 26 ++++++++++++++++++++++++++
 drivers/devfreq/governor.h                |  2 ++
 drivers/devfreq/governor_simpleondemand.c |  9 +++++++++
 include/linux/devfreq.h                   | 12 ++++++++++++
 4 files changed, 49 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index be524c7..3a5f126 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -365,6 +365,32 @@ int devfreq_remove_device(struct devfreq *devfreq)
 }
 EXPORT_SYMBOL(devfreq_remove_device);
 
+/**
+ * devfreq_suspend_device() - Suspend devfreq of a device.
+ * @devfreq	the devfreq instance to be suspended
+ */
+int devfreq_suspend_device(struct devfreq *devfreq)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	return devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_SUSPEND);
+}
+EXPORT_SYMBOL(devfreq_suspend_device);
+
+/**
+ * devfreq_resume_device() - Resume devfreq of a device.
+ * @devfreq	the devfreq instance to be resumed
+ */
+int devfreq_resume_device(struct devfreq *devfreq)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	return devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_RESUME);
+}
+EXPORT_SYMBOL(devfreq_resume_device);
+
 static ssize_t show_governor(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
index 4a86af7..7dbbdfc 100644
--- a/drivers/devfreq/governor.h
+++ b/drivers/devfreq/governor.h
@@ -22,6 +22,8 @@
 #define DEVFREQ_GOV_START			0x1
 #define DEVFREQ_GOV_STOP			0x2
 #define DEVFREQ_GOV_INTERVAL			0x3
+#define DEVFREQ_GOV_SUSPEND			0x4
+#define DEVFREQ_GOV_RESUME			0x5
 
 /* Caution: devfreq->lock must be locked before calling update_devfreq */
 extern int update_devfreq(struct devfreq *devfreq);
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index 9802bf9..35b8e8e 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -113,6 +113,15 @@ int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
 		else
 			ret = devfreq_monitor_resume(devfreq);
 		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		ret = devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		ret = devfreq_monitor_resume(devfreq);
+		break;
+
 	default:
 		break;
 	}
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 7a11c3e..7c7e179 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -155,6 +155,8 @@ extern struct devfreq *devfreq_add_device(struct device *dev,
 				  const struct devfreq_governor *governor,
 				  void *data);
 extern int devfreq_remove_device(struct devfreq *devfreq);
+extern int devfreq_suspend_device(struct devfreq *devfreq);
+extern int devfreq_resume_device(struct devfreq *devfreq);
 
 /* Helper functions for devfreq user device driver with OPP. */
 extern struct opp *devfreq_recommended_opp(struct device *dev,
@@ -208,6 +210,16 @@ static int devfreq_remove_device(struct devfreq *devfreq)
 	return 0;
 }
 
+static int devfreq_suspend_device(struct devfreq *devfreq)
+{
+	return 0;
+}
+
+static int devfreq_resume_device(struct devfreq *devfreq)
+{
+	return 0;
+}
+
 static struct opp *devfreq_recommended_opp(struct device *dev,
 					   unsigned long *freq, u32 flags)
 {
-- 
1.7.11.3

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