power: supply: core: introduce power_supply_has_property()

Introduce a helper to check if a power supply implements a certain
property. It will be used by the sysfs and hwmon code to remove similar
open-coded checks.
It also paves the way for the extension API to hook into.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Reviewed-by: Hans de Goede <[e-mail]>
Reviewed-by: Sebastian Reichel <[e-mail]>
Reviewed-by: Armin Wolf <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/power_supply.h

···
 
 extern int power_supply_property_is_writeable(struct power_supply *psy,
 					      enum power_supply_property psp);
+extern bool power_supply_has_property(struct power_supply *psy,
+				      enum power_supply_property psp);
 
 #ifdef CONFIG_SYSFS
 

drivers/power/supply/power_supply_core.c

···
 	return found;
 }
 
+bool power_supply_has_property(struct power_supply *psy,
+			       enum power_supply_property psp)
+{
+	if (psy_desc_has_property(psy->desc, psp))
+		return true;
+
+	if (power_supply_battery_info_has_prop(psy->battery_info, psp))
+		return true;
+
+	return false;
+}
+
 int power_supply_get_property(struct power_supply *psy,
 			    enum power_supply_property psp,
 			    union power_supply_propval *val)