power: supply: max17042_battery: Add support for the CHARGE_NOW property

At least upower prefers the more precise charge_now sysfs value over
capacity and the max17042 has the info, so lets export it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/power/supply/max17042_battery.c

@@ -89,6 +89,7 @@ static enum power_supply_property max17042_battery_props[] = {
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
@@ -320,6 +321,15 @@ static int max17042_get_property(struct power_supply *psy,
 		if (ret < 0)
 			return ret;
 
+		data64 = data * 5000000ll;
+		do_div(data64, chip->pdata->r_sns);
+		val->intval = data64;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		ret = regmap_read(map, MAX17042_RepCap, &data);
+		if (ret < 0)
+			return ret;
+
 		data64 = data * 5000000ll;
 		do_div(data64, chip->pdata->r_sns);
 		val->intval = data64;