PM / OPP: Implement dev_pm_opp_get_of_node()

This adds a new helper to let the power domain drivers to access
opp->np, so that they can read platform specific properties from the
node.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/opp/of.c

@@ -727,3 +727,22 @@ struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev,
 	return opp;
 }
 EXPORT_SYMBOL_GPL(of_dev_pm_opp_find_required_opp);
+
+/**
+ * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
+ * @opp:	opp for which DT node has to be returned for
+ *
+ * Return: DT node corresponding to the opp, else 0 on success.
+ *
+ * The caller needs to put the node with of_node_put() after using it.
+ */
+struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
+{
+	if (IS_ERR_OR_NULL(opp)) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return NULL;
+	}
+
+	return of_node_get(opp->np);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);

include/linux/pm_opp.h

@@ -310,6 +310,7 @@ void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask);
 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask);
 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev);
 struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, struct device_node *np);
+struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp);
 #else
 static inline int dev_pm_opp_of_add_table(struct device *dev)
 {
@@ -348,6 +349,10 @@ static inline struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *
 {
 	return NULL;
 }
+static inline struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
+{
+	return NULL;
+}
 #endif
 
 #endif		/* __LINUX_OPP_H__ */