Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs...

[pandora-kernel.git] / drivers / base / power / opp.c

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index b23de18..434a6c0 100644 (file)
--- 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;
+}