opp: Implement dev_pm_opp_set_opp()

The new helper dev_pm_opp_set_opp() can be used for configuring the
devices for a particular OPP and can be used by different type of
devices, even the ones which don't change frequency (like power
domains).
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>

drivers/opp/core.c

@@ -1136,6 +1136,34 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
 
+/**
+ * dev_pm_opp_set_opp() - Configure device for OPP
+ * @dev: device for which we do this operation
+ * @opp: OPP to set to
+ *
+ * This configures the device based on the properties of the OPP passed to this
+ * routine.
+ *
+ * Return: 0 on success, a negative error number otherwise.
+ */
+int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp)
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+		return PTR_ERR(opp_table);
+	}
+
+	ret = _set_opp(dev, opp_table, opp, opp ? opp->rate : 0);
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_opp);
+
 /* OPP-dev Helpers */
 static void _remove_opp_dev(struct opp_device *opp_dev,
 			    struct opp_table *opp_table)

include/linux/pm_opp.h

@@ -158,6 +158,7 @@ void dev_pm_opp_detach_genpd(struct opp_table *opp_table);
 struct opp_table *devm_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);
 int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);
 int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);
+int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp);
 int dev_pm_opp_set_bw(struct device *dev, struct dev_pm_opp *opp);
 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, const struct cpumask *cpumask);
 int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask);
@@ -377,6 +378,11 @@ static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long target_f
 	return -ENOTSUPP;
 }
 
+static inline int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp)
+{
+	return -ENOTSUPP;
+}
+
 static inline int dev_pm_opp_set_bw(struct device *dev, struct dev_pm_opp *opp)
 {
 	return -EOPNOTSUPP;