regulator: Implement devm_regulator_free()

Allow consumers to free regulators allocated using devm_regulator_get()
if they need to. This will not normally be required.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/core.c

@@ -1421,6 +1421,34 @@ void regulator_put(struct regulator *regulator)
 }
 EXPORT_SYMBOL_GPL(regulator_put);
 
+static int devm_regulator_match(struct device *dev, void *res, void *data)
+{
+	struct regulator **r = res;
+	if (!r || !*r) {
+		WARN_ON(!r || !*r);
+		return 0;
+	}
+	return *r == data;
+}
+
+/**
+ * devm_regulator_put - Resource managed regulator_put()
+ * @regulator: regulator to free
+ *
+ * Deallocate a regulator allocated with devm_regulator_get(). Normally
+ * this function will not need to be called and the resource management
+ * code will ensure that the resource is freed.
+ */
+void devm_regulator_put(struct regulator *regulator)
+{
+	int rc;
+
+	rc = devres_destroy(regulator->dev, devm_regulator_release,
+			    devm_regulator_match, regulator);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_regulator_put);
+
 static int _regulator_can_change_status(struct regulator_dev *rdev)
 {
 	if (!rdev->constraints)

include/linux/regulator/consumer.h

@@ -137,6 +137,7 @@ struct regulator *__must_check devm_regulator_get(struct device *dev,
 struct regulator *__must_check regulator_get_exclusive(struct device *dev,
 						       const char *id);
 void regulator_put(struct regulator *regulator);
+void devm_regulator_free(struct regulator *regulator);
 
 /* regulator output control and status */
 int regulator_enable(struct regulator *regulator);