power: Add devm_power_supply_get_by_phandle() helper function

This commit adds a resource-managed version of the
power_supply_get_by_phandle() function.

Signed-off-by: Hans de Goede <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/power_supply_core.c

···
 	return psy;
 }
 EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
+
+static void devm_power_supply_put(struct device *dev, void *res)
+{
+	struct power_supply **psy = res;
+
+	power_supply_put(*psy);
+}
+
+/**
+ * devm_power_supply_get_by_phandle() - Resource managed version of
+ *  power_supply_get_by_phandle()
+ * @dev: Pointer to device holding phandle property
+ * @phandle_name: Name of property holding a power supply phandle
+ *
+ * Return: On success returns a reference to a power supply with
+ * matching name equals to value under @property, NULL or ERR_PTR otherwise.
+ */
+struct power_supply *devm_power_supply_get_by_phandle(struct device *dev,
+						      const char *property)
+{
+	struct power_supply **ptr, *psy;
+
+	if (!dev->of_node)
+		return ERR_PTR(-ENODEV);
+
+	ptr = devres_alloc(devm_power_supply_put, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	psy = power_supply_get_by_phandle(dev->of_node, property);
+	if (IS_ERR_OR_NULL(psy)) {
+		devres_free(ptr);
+	} else {
+		*ptr = psy;
+		devres_add(dev, ptr);
+	}
+	return psy;
+}
+EXPORT_SYMBOL_GPL(devm_power_supply_get_by_phandle);
 #endif /* CONFIG_OF */
 
 int power_supply_get_property(struct power_supply *psy,

include/linux/power_supply.h

···
 #ifdef CONFIG_OF
 extern struct power_supply *power_supply_get_by_phandle(struct device_node *np,
 							const char *property);
+extern struct power_supply *devm_power_supply_get_by_phandle(
+				    struct device *dev, const char *property);
 #else /* !CONFIG_OF */
 static inline struct power_supply *
 power_supply_get_by_phandle(struct device_node *np, const char *property)
+{ return NULL; }
+static inline struct power_supply *
+devm_power_supply_get_by_phandle(struct device *dev, const char *property)
 { return NULL; }
 #endif /* CONFIG_OF */
 extern void power_supply_changed(struct power_supply *psy);