一般是由fg的芯片来判断,通过IIC读取,具体判断可参考: case POWER_SUPPLY_PROP_CAPACITY_LEVEL: if (battery->state & ACPI_BATTERY_STATE_CRITICAL) val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL; else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) && (battery->capacity_now <= batt...