power: supply: core: Avoid duplicate hwmon device from thermal framework

When the power supply device being registered supports a temperature
readout, the core registers a thermal zone for it. The thermal core
would register a hwmon device for that unless told otherwise.

When CONFIG_POWER_SUPPLY_HWMON is enabled, the power supply core creates
a hwmon device. This results in a second entry, one which has a better
name than the one registered through the thermal framework. It could
potentially have readouts other than temperature.

To simplify the result, tell the thermal framework to not register a
hwmon device if CONFIG_POWER_SUPPLY_HWMON is enabled. The result is
one hwmon device with all the readings the device supports.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: wens

drivers/power/supply/power_supply_core.c

@@ -1305,8 +1305,12 @@ static int psy_register_thermal(struct power_supply *psy)
 
 	/* Register battery zone device psy reports temperature */
 	if (psy_has_property(psy->desc, POWER_SUPPLY_PROP_TEMP)) {
+		/* Prefer our hwmon device and avoid duplicates */
+		struct thermal_zone_params tzp = {
+			.no_hwmon = IS_ENABLED(CONFIG_POWER_SUPPLY_HWMON)
+		};
 		psy->tzd = thermal_zone_device_register(psy->desc->name,
-				0, 0, psy, &psy_tzd_ops, NULL, 0, 0);
+				0, 0, psy, &psy_tzd_ops, &tzp, 0, 0);
 		if (IS_ERR(psy->tzd))
 			return PTR_ERR(psy->tzd);
 		ret = thermal_zone_device_enable(psy->tzd);