X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=drivers%2Fbase%2Fpower%2Fopp.c;h=434a6c01167521007e14f11ad0d7f2accdb8cf7b;hp=b23de185cb04bd60a4779a0cb612849c119856b1;hb=f362f98e7c445643d27c610bb7a86b79727b592e;hpb=538d2882213ef4f076108f3edda2c39a584c4c2b

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index b23de185cb04..434a6c011675 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -73,6 +73,7 @@ struct opp {
  *		RCU usage: nodes are not modified in the list of device_opp,
  *		however addition is possible and is secured by dev_opp_list_lock
  * @dev:	device pointer
+ * @head:	notifier head to notify the OPP availability changes.
  * @opp_list:	list of opps
  *
  * This is an internal data structure maintaining the link to opps attached to
@@ -83,6 +84,7 @@ struct device_opp {
 	struct list_head node;
 
 	struct device *dev;
+	struct srcu_notifier_head head;
 	struct list_head opp_list;
 };
 
@@ -404,6 +406,7 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 		}
 
 		dev_opp->dev = dev;
+		srcu_init_notifier_head(&dev_opp->head);
 		INIT_LIST_HEAD(&dev_opp->opp_list);
 
 		/* Secure the device list modification */
@@ -428,6 +431,11 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 	list_add_rcu(&new_opp->node, head);
 	mutex_unlock(&dev_opp_list_lock);
 
+	/*
+	 * Notify the changes in the availability of the operable
+	 * frequency/voltage list.
+	 */
+	srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp);
 	return 0;
 }
 
@@ -504,6 +512,14 @@ static int opp_set_availability(struct device *dev, unsigned long freq,
 	mutex_unlock(&dev_opp_list_lock);
 	synchronize_rcu();
 
+	/* Notify the change of the OPP availability */
+	if (availability_req)
+		srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE,
+					 new_opp);
+	else
+		srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE,
+					 new_opp);
+
 	/* clean up old opp */
 	new_opp = opp;
 	goto out;
@@ -643,3 +659,17 @@ void opp_free_cpufreq_table(struct device *dev,
 	*table = NULL;
 }
 #endif		/* CONFIG_CPU_FREQ */
+
+/**
+ * opp_get_notifier() - find notifier_head of the device with opp
+ * @dev:	device pointer used to lookup device OPPs.
+ */
+struct srcu_notifier_head *opp_get_notifier(struct device *dev)
+{
+	struct device_opp *dev_opp = find_device_opp(dev);
+
+	if (IS_ERR(dev_opp))
+		return ERR_PTR(PTR_ERR(dev_opp)); /* matching type */
+
+	return &dev_opp->head;
+}