power_supply: get_by_name and set_charged functionality

This adds a function that indicates that a battery is fully charged.
It also includes functions to get a power_supply device from the class
of registered devices by name reference. These can be used to find a
specific battery to call power_supply_set_battery_charged() on.

Some battery drivers might need this information to calibrate
themselves.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Ian Molton <spyro@f2s.com>
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/power_supply_core.c

@@ -116,6 +116,34 @@ int power_supply_is_system_supplied(void)
 }
 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 
+int power_supply_set_battery_charged(struct power_supply *psy)
+{
+	if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
+		psy->set_charged(psy);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
+
+static int power_supply_match_device_by_name(struct device *dev, void *data)
+{
+	const char *name = data;
+	struct power_supply *psy = dev_get_drvdata(dev);
+
+	return strcmp(psy->name, name) == 0;
+}
+
+struct power_supply *power_supply_get_by_name(char *name)
+{
+	struct device *dev = class_find_device(power_supply_class, NULL, name,
+					power_supply_match_device_by_name);
+
+	return dev ? dev_get_drvdata(dev) : NULL;
+}
+EXPORT_SYMBOL_GPL(power_supply_get_by_name);
+
 int power_supply_register(struct device *parent, struct power_supply *psy)
 {
 	int rc = 0;