Add and implement the dev_pm_opp_get_bw() to retrieve
the OPP's bandwidth in the same way as the dev_pm_opp_get_voltage()
helper.

Retrieving bandwidth is required in the case of the Adreno GPU
where the GPU Management Unit can handle the Bandwidth scaling.

The helper can get the peak or average bandwidth for any of
the interconnect path.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/opp/core.c     | 25 +++++++++++++++++++++++++
 include/linux/pm_opp.h |  7 +++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 494f8860220d97fc690ebab5ed3b7f5f04f22d73..864b9b99b0129acaffaf45c584c5f34b8bababed 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -106,6 +106,31 @@ static bool assert_single_clk(struct opp_table *opp_table)
 	return !WARN_ON(opp_table->clk_count > 1);
 }
 
+/**
+ * dev_pm_opp_get_bw() - Gets the bandwidth corresponding to an opp
+ * @opp:	opp for which voltage has to be returned for
+ * @peak:	select peak or average bandwidth
+ * @index:	bandwidth index
+ *
+ * Return: bandwidth in kBps, else return 0
+ */
+unsigned long dev_pm_opp_get_bw(struct dev_pm_opp *opp, bool peak, int index)
+{
+	if (IS_ERR_OR_NULL(opp)) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return 0;
+	}
+
+	if (index > opp->opp_table->path_count)
+		return 0;
+
+	if (!opp->bandwidth)
+		return 0;
+
+	return peak ? opp->bandwidth[index].peak : opp->bandwidth[index].avg;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_bw);
+
 /**
  * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
  * @opp:	opp for which voltage has to be returned for
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 6424692c30b71fca471a1b7d63e018605dd9324b..cd9a257b8e7766d6c8631351a10a845c88414a74 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -106,6 +106,8 @@ struct dev_pm_opp_data {
 struct opp_table *dev_pm_opp_get_opp_table(struct device *dev);
 void dev_pm_opp_put_opp_table(struct opp_table *opp_table);
 
+unsigned long dev_pm_opp_get_bw(struct dev_pm_opp *opp, bool peak, int index);
+
 unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp);
 
 int dev_pm_opp_get_supplies(struct dev_pm_opp *opp, struct dev_pm_opp_supply *supplies);
@@ -209,6 +211,11 @@ static inline struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *
 
 static inline void dev_pm_opp_put_opp_table(struct opp_table *opp_table) {}
 
+static inline unsigned long dev_pm_opp_get_bw(struct dev_pm_opp *opp, bool peak, int index)
+{
+	return 0;
+}
+
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
 	return 0;

-- 
2.34.1