static int olpc_bat_get_property()

in supply/olpc_battery.c [334:477]

• 126 lines of code
• 42 McCabe index (conditional complexity)

static int olpc_bat_get_property(struct power_supply *psy,
				 enum power_supply_property psp,
				 union power_supply_propval *val)
{
	struct olpc_battery_data *data = power_supply_get_drvdata(psy);
	int ret = 0;
	u16 ec_word;
	uint8_t ec_byte;
	__be64 ser_buf;

	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
	if (ret)
		return ret;

	/* Theoretically there's a race here -- the battery could be
	   removed immediately after we check whether it's present, and
	   then we query for some other property of the now-absent battery.
	   It doesn't matter though -- the EC will return the last-known
	   information, and it's as if we just ran that _little_ bit faster
	   and managed to read it out before the battery went away. */
	if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) &&
			psp != POWER_SUPPLY_PROP_PRESENT)
		return -ENODEV;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
		ret = olpc_bat_get_status(data, val, ec_byte);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
		if (ec_byte & BAT_STAT_TRICKLE)
			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
		else if (ec_byte & BAT_STAT_CHARGING)
			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
		else
			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
		break;
	case POWER_SUPPLY_PROP_PRESENT:
		val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
					    BAT_STAT_TRICKLE));
		break;

	case POWER_SUPPLY_PROP_HEALTH:
		if (ec_byte & BAT_STAT_DESTROY)
			val->intval = POWER_SUPPLY_HEALTH_DEAD;
		else {
			ret = olpc_bat_get_health(val);
			if (ret)
				return ret;
		}
		break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
		ret = olpc_bat_get_mfr(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
		ret = olpc_bat_get_tech(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = ecword_to_cpu(data, ec_word) * 9760L / 32;
		break;
	case POWER_SUPPLY_PROP_CURRENT_AVG:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = ecword_to_cpu(data, ec_word) * 15625L / 120;
		break;
	case POWER_SUPPLY_PROP_CAPACITY:
		ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
		if (ret)
			return ret;
		val->intval = ec_byte;
		break;
	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
		if (ec_byte & BAT_STAT_FULL)
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
		else if (ec_byte & BAT_STAT_LOW)
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
		else
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
		break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
		ret = olpc_bat_get_charge_full_design(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_CHARGE_NOW:
		ret = olpc_bat_get_charge_now(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_TEMP:
		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = ecword_to_cpu(data, ec_word) * 10 / 256;
		break;
	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
		ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (int)ecword_to_cpu(data, ec_word) * 10 / 256;
		break;
	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
		ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = ecword_to_cpu(data, ec_word) * 6250 / 15;
		break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
		ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
		if (ret)
			return ret;

		sprintf(data->bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
		val->strval = data->bat_serial;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
		ret = olpc_bat_get_voltage_max_design(val);
		if (ret)
			return ret;
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}