1 files changed, 99 insertions, 0 deletions

diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 6fa02a20eb63..2de4e2eea180 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -19,6 +19,13 @@
 
 #define DEVFREQ_NAME_LEN 16
 
+/* DEVFREQ notifier interface */
+#define DEVFREQ_TRANSITION_NOTIFIER	(0)
+
+/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
+#define	DEVFREQ_PRECHANGE		(0)
+#define DEVFREQ_POSTCHANGE		(1)
+
 struct devfreq;
 
 /**
@@ -143,6 +150,7 @@ struct devfreq_governor {
  * @trans_table:	Statistics of devfreq transitions
  * @time_in_state:	Statistics of devfreq states
  * @last_stat_updated:	The last time stat updated
+ * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
  *
  * This structure stores the devfreq information for a give device.
  *
@@ -177,6 +185,13 @@ struct devfreq {
 	unsigned int *trans_table;
 	unsigned long *time_in_state;
 	unsigned long last_stat_updated;
+
+	struct srcu_notifier_head transition_notifier_list;
+};
+
+struct devfreq_freqs {
+	unsigned long old;
+	unsigned long new;
 };
 
 #if defined(CONFIG_PM_DEVFREQ)
@@ -207,6 +222,22 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
 					      struct devfreq *devfreq);
 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 						struct devfreq *devfreq);
+extern int devfreq_register_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list);
+extern int devfreq_unregister_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list);
+extern int devm_devfreq_register_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list);
+extern void devm_devfreq_unregister_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list);
+extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+						int index);
 
 /**
  * devfreq_update_stats() - update the last_status pointer in struct devfreq
@@ -241,6 +272,39 @@ struct devfreq_simple_ondemand_data {
 };
 #endif
 
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+/**
+ * struct devfreq_passive_data - void *data fed to struct devfreq
+ *	and devfreq_add_device
+ * @parent:	the devfreq instance of parent device.
+ * @get_target_freq:	Optional callback, Returns desired operating frequency
+ *			for the device using passive governor. That is called
+ *			when passive governor should decide the next frequency
+ *			by using the new frequency of parent devfreq device
+ *			using governors except for passive governor.
+ *			If the devfreq device has the specific method to decide
+ *			the next frequency, should use this callback.
+ * @this:	the devfreq instance of own device.
+ * @nb:		the notifier block for DEVFREQ_TRANSITION_NOTIFIER list
+ *
+ * The devfreq_passive_data have to set the devfreq instance of parent
+ * device with governors except for the passive governor. But, don't need to
+ * initialize the 'this' and 'nb' field because the devfreq core will handle
+ * them.
+ */
+struct devfreq_passive_data {
+	/* Should set the devfreq instance of parent device */
+	struct devfreq *parent;
+
+	/* Optional callback to decide the next frequency of passvice device */
+	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
+
+	/* For passive governor's internal use. Don't need to set them */
+	struct devfreq *this;
+	struct notifier_block nb;
+};
+#endif
+
 #else /* !CONFIG_PM_DEVFREQ */
 static inline struct devfreq *devfreq_add_device(struct device *dev,
 					  struct devfreq_dev_profile *profile,
@@ -307,6 +371,41 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
 {
 }
 
+static inline int devfreq_register_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list)
+{
+	return 0;
+}
+
+static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list)
+{
+	return 0;
+}
+
+static inline int devm_devfreq_register_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	return 0;
+}
+
+static inline void devm_devfreq_unregister_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+}
+
+static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+							int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline int devfreq_update_stats(struct devfreq *df)
 {
 	return -EINVAL;