hci_read
u32 result = hci_read(dev, HCI_COOLING_METHOD, state);
u32 result = hci_read(dev, HCI_TR_BACKLIGHT, status);
result = hci_read(dev, HCI_LCD_BRIGHTNESS, &value);
u32 result = hci_read(dev, HCI_VIDEO_OUT, status);
u32 result = hci_read(dev, HCI_FAN, status);
result = hci_read(dev, HCI_SYSTEM_EVENT, &value);
result = hci_read(dev, HCI_KBD_ILLUMINATION, &state);