ACPI: battery: Convert discharge energy rate to current properly

ACPI battery interface reports its state either in mW or in mA, and
discharge rate in your case is reported in mW. power_supply interface
does not have such a parameter, so current_now parameter is used
for all cases. But in case of mW, reported discharge should
be converted into mA.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/battery.c

@@ -174,6 +174,15 @@ static int acpi_battery_get_property(struct power_supply *psy,
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		val->intval = battery->current_now * 1000;
+		/* if power units are mW, convert to mA by
+		   dividing by current voltage (mV/1000) */
+		if (!battery->power_unit) {
+			if (battery->voltage_now) {
+				val->intval /= battery->voltage_now;
+				val->intval *= 1000;
+			} else
+				val->intval = -1;
+		}
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN: