PM / OPP: Disable OPPs that aren't supported by the regulator

Disable any OPPs where the connected regulator isn't able to provide the
specified voltage.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 7d34d56ef3349cd5f29cf7aab6650f3414fa81b9)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

Author: vireshk

drivers/base/power/opp/core.c

@@ -687,6 +687,22 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev,
 	return opp;
 }
 
+static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
+					 struct device_opp *dev_opp)
+{
+	struct regulator *reg = dev_opp->regulator;
+
+	if (!IS_ERR(reg) &&
+	    !regulator_is_supported_voltage(reg, opp->u_volt_min,
+					    opp->u_volt_max)) {
+		pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
+			__func__, opp->u_volt_min, opp->u_volt_max);
+		return false;
+	}
+
+	return true;
+}
+
 static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 		    struct device_opp *dev_opp)
 {
@@ -728,6 +744,12 @@ static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 		dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
 			__func__, ret);
 
+	if (!_opp_supported_by_regulators(new_opp, dev_opp)) {
+		new_opp->available = false;
+		dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
+			 __func__, new_opp->rate);
+	}
+
 	return 0;
 }