OPP: Add support for parsing the 'opp-level' property

Now that the OPP bindings are updated to include an optional
'opp-level' property, add support to parse it from device tree
and store it as part of dev_pm_opp structure.
Also add and export an helper 'dev_pm_opp_get_level()' that can be
used to get the level value read from device tree when present.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

drivers/opp/core.c

@@ -130,6 +130,24 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
 
+/**
+ * dev_pm_opp_get_level() - Gets the level corresponding to an available opp
+ * @opp:	opp for which level value has to be returned for
+ *
+ * Return: level read from device tree corresponding to the opp, else
+ * return 0.
+ */
+unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)
+{
+	if (IS_ERR_OR_NULL(opp) || !opp->available) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return 0;
+	}
+
+	return opp->level;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_level);
+
 /**
  * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
  * @opp: opp for which turbo mode is being verified

drivers/opp/of.c

@@ -594,6 +594,8 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 		new_opp->rate = (unsigned long)rate;
 	}
 
+	of_property_read_u32(np, "opp-level", &new_opp->level);
+
 	/* Check if the OPP supports hardware's hierarchy of versions or not */
 	if (!_opp_is_supported(dev, opp_table, np)) {
 		dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);

drivers/opp/opp.h

@@ -60,6 +60,7 @@ extern struct list_head opp_tables;
  * @suspend:	true if suspend OPP
  * @pstate: Device's power domain's performance state.
  * @rate:	Frequency in hertz
+ * @level:	Performance level
  * @supplies:	Power supplies voltage/current values
  * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
  *		frequency from any other OPP's frequency.
@@ -80,6 +81,7 @@ struct dev_pm_opp {
 	bool suspend;
 	unsigned int pstate;
 	unsigned long rate;
+	unsigned int level;
 
 	struct dev_pm_opp_supply *supplies;
 

include/linux/pm_opp.h

@@ -86,6 +86,8 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp);
 
 unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp);
 
+unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp);
+
 bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp);
 
 int dev_pm_opp_get_opp_count(struct device *dev);
@@ -157,6 +159,11 @@ static inline unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
 	return 0;
 }
 
+static inline unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)
+{
+	return 0;
+}
+
 static inline bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
 {
 	return false;