acpi_ibm

NAME

acpi_ibm — ACPI extras driver for IBM laptops

SYNOPSIS

To compile this driver into the kernel, place the following line in your kernel configuration file:

device acpi_ibm

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

acpi_ibm_load="YES"

The acpi_ibm driver provides support for hotkeys and other components of IBM laptops. The main purpose of this driver is to provide an interface, accessible via sysctl(8) and devd(8), through which applications can determine the status of various laptop components.

While the sysctl(8) interface is enabled automatically after loading the driver, the devd(8) interface has to be enabled explicitly, as it may alter the default action of certain keys. This is done by setting the events sysctl as described below. Specifying which keys should generate events is done by setting a bitmask, whereas each bit represents one key or key combination. This bitmask, accessible via the eventmask sysctl, is set to availmask by default, a value representing all possible keypress events on the specific ThinkPad model.

devd(8) Events

Hotkey events received by devd(8) provide the following information:

system: “ACPI”
subsystem: “IBM”
type: The source of the event in the ACPI namespace. The value depends on the model.
notify: Event code (see below).

Depending on the ThinkPad model, event codes may vary. On a ThinkPad T41p these are as follows:

0x01: Fn + F1
0x02: Fn + F2
0x03: Fn + F3 (LCD backlight)
0x04: Fn + F4 (Suspend to RAM)
0x05: Fn + F5 (Bluetooth)
0x06: Fn + F6
0x07: Fn + F7 (Screen expand)
0x08: Fn + F8
0x09: Fn + F9
0x0a: Fn + F10
0x0b: Fn + F11
0x0c: Fn + F12 (Suspend to disk)
0x0d: Fn + Backspace
0x0e: Fn + Insert
0x0f: Fn + Delete
0x10: Fn + Home (Brightness up)
0x11: Fn + End (Brightness down)
0x12: Fn + PageUp (ThinkLight)
0x13: Fn + PageDown
0x14: Fn + Space (Zoom)
0x15: Volume Up
0x16: Volume Down
0x17: Mute
0x18: Access IBM Button

led(4) Interface

The acpi_ibm driver provides a led(4) interface for the ThinkLight. The ThinkLight can be made to blink by writing ASCII strings to the /dev/led/thinklight device.

SYSCTL VARIABLES

The following sysctls are currently implemented:

dev.acpi_ibm.0.initialmask

(read-only) Bitmask of ACPI events before the acpi_ibm driver was loaded.

dev.acpi_ibm.0.availmask

(read-only) Bitmask of all supported ACPI events.

dev.acpi_ibm.0.events

Enable ACPI events and set the eventmask to availmask. Without the acpi_ibm driver being loaded, only the Fn+F4 button generates an ACPI event.

dev.acpi_ibm.0.eventmask

Sets the ACPI events which are reported to devd(8). Fn+F3, Fn+F4 and Fn+F12 always generate ACPI events, regardless which value eventmask has. Depending on the ThinkPad model, the meaning of different bits in the eventmask may vary. On a ThinkPad T41p this is a bitwise OR of the following:

1: Fn + F1
2: Fn + F2
4: Fn + F3 (LCD backlight)
8: Fn + F4 (Suspend to RAM)
16: Fn + F5 (Bluetooth)
32: Fn + F6
64: Fn + F7 (Screen expand)
128: Fn + F8
256: Fn + F9
512: Fn + F10
1024: Fn + F11
2048: Fn + F12 (Suspend to disk)
4096: Fn + Backspace
8192: Fn + Insert
16384: Fn + Delete
32768: Fn + Home (Brightness up)
65536: Fn + End (Brightness down)
131072: Fn + PageUp (ThinkLight)
262144: Fn + PageDown
524288: Fn + Space (Zoom)
1048576: Volume Up
2097152: Volume Down
4194304: Mute
8388608: Access IBM Button

dev.acpi_ibm.0.hotkey

(read-only) Status of several buttons. Every time a button is pressed, the respecting bit is toggled. It is a bitwise OR of the following:

1: Home Button
2: Search Button
4: Mail Button
8: Access IBM Button
16: Zoom
32: Wireless LAN Button
64: Video Button
128: Hibernate Button
256: ThinkLight Button
512: Screen Expand
1024: Brightness Up/Down Button
2048: Volume Up/Down/Mute Button

dev.acpi_ibm.0.lcd_brightness

Current brightness level of the display.

dev.acpi_ibm.0.volume

Speaker volume.

dev.acpi_ibm.0.mute

Indicates, whether the speakers are muted or not.

dev.acpi_ibm.0.thinklight

Indicates, whether the ThinkLight keyboard light is activated or not.

dev.acpi_ibm.0.bluetooth

Toggle Bluetooth chip activity.

dev.acpi_ibm.0.wlan

(read-only) Indicates whether the WLAN chip is active or not.

dev.acpi_ibm.0.fan

Indicates whether the fan is in automatic (1) or manual (0) mode. Default is automatic mode. This sysctl should be used with extreme precaution, since disabling automatic fan control might overheat the ThinkPad and lead to permanent damage if the fan_level is not set accordingly.

dev.acpi_ibm.0.fan_level

Indicates at what speed the fan should run when being in manual mode. Valid values range from 0 (off) to 7 (max) and 8. Level 8 is used by the driver to set the fan in unthrottled mode. In this mode, the fan is set to spin freely and will quickly reach a very high speed. Use this mode only if absolutely necessary, e.g., if the system has reached its critical temperature and it is about to shut down. The resulting speed differs from model to model. On a T41p this is as follows:

0: off
1, 2: ~3000 RPM
3, 4, 5: ~3600 RPM
6, 7: ~4300 RPM
8: ~6400 RPM (Full-speed, unthrottled)

dev.acpi_ibm.0.fan_speed

(read-only) Fan speed in rounds per minute. A few older ThinkPads report the fan speed in levels ranging from 0 (off) to 7 (max).

dev.acpi_ibm.0.thermal

(read-only) Shows the readings of up to eight different temperature sensors. Most ThinkPads include six or more temperature sensors but only expose the CPU temperature through acpi_thermal(4). Some ThinkPads have the below sensor layout which might vary depending on the specific model:

CPU
Mini PCI Module
HDD
GPU
Built-in battery
UltraBay battery
Built-in battery
UltraBay battery

dev.acpi_ibm.0.handlerevents

devd(8) events handled by acpi_ibm when events is set to 1. Events are specified as a whitespace-separated list of event code in hexadecimal or decimal form. Note that the event maybe handled twice (e.g., Brightness up/down) if ACPI BIOS already handled the event.

Defaults for these sysctls can be set in sysctl.conf(5).

FILES

/dev/led/thinklight: ThinkLight led(4) device node

EXAMPLES

The following can be added to devd.conf(5) in order to pass button events to a /usr/local/sbin/acpi_oem_exec.sh script:

notify 10 { 
        match "system"          "ACPI"; 
        match "subsystem"       "IBM"; 
        action "/usr/local/sbin/acpi_oem_exec.sh $notify ibm"; 
};

A possible /usr/local/sbin/acpi_oem_exec.sh script might look like:

#!/bin/sh 
# 
if [ "$1" = "" -o "$2" = "" ] 
then 
        echo "usage: $0 notify oem_name" 
        exit 1 
fi 
NOTIFY=`echo $1` 
LOGGER="logger" 
CALC="bc" 
BC_PRECOMMANDS="scale=2" 
ECHO="echo" 
CUT="cut" 
MAX_LCD_BRIGHTNESS=7 
MAX_VOLUME=14 
OEM=$2 
DISPLAY_PIPE=/tmp/acpi_${OEM}_display 
 
case ${NOTIFY} in 
        0x05) 
                LEVEL=`sysctl -n dev.acpi_${OEM}.0.bluetooth` 
                if [ "$LEVEL" = "1" ] 
                then 
                        sysctl dev.acpi_${OEM}.0.bluetooth=0 
                        MESSAGE="bluetooth disabled" 
                else 
                        sysctl dev.acpi_${OEM}.0.bluetooth=1 
                        MESSAGE="bluetooth enabled" 
                fi 
                ;; 
        0x10|0x11) 
                LEVEL=`sysctl -n dev.acpi_${OEM}.0.lcd_brightness` 
                PERCENT=`${ECHO} "${BC_PRECOMMANDS} ; \ 
                         ${LEVEL} / ${MAX_LCD_BRIGHTNESS} * 100" |\ 
                         ${CALC} | ${CUT} -d . -f 1` 
                MESSAGE="brightness level ${PERCENT}%" 
                ;; 
        0x12) 
                LEVEL=`sysctl -n dev.acpi_${OEM}.0.thinklight` 
                if [ "$LEVEL" = "1" ] 
                then 
                        MESSAGE="thinklight enabled" 
                else 
                        MESSAGE="thinklight disabled" 
                fi 
                ;; 
        0x15|0x16) 
                LEVEL=`sysctl -n dev.acpi_${OEM}.0.volume` 
                PERCENT=`${ECHO} "${BC_PRECOMMANDS} ; \ 
                        ${LEVEL} / ${MAX_VOLUME} * 100" | \ 
                         ${CALC} | ${CUT} -d . -f 1` 
                MESSAGE="volume level ${PERCENT}%" 
                ;; 
        0x17) 
                LEVEL=`sysctl -n dev.acpi_${OEM}.0.mute` 
                if [ "$LEVEL" = "1" ] 
                then 
                        MESSAGE="volume muted" 
                else 
                        MESSAGE="volume unmuted" 
                fi 
                ;; 
        *) 
                ;; 
esac 
${LOGGER} ${MESSAGE} 
if [ -p ${DISPLAY_PIPE} ] 
then 
        ${ECHO} ${MESSAGE} >> ${DISPLAY_PIPE} & 
fi 
exit 0

The following example specify that event code 0x04 (Suspend to RAM), 0x10 (Brightness up) and 0x11 (Brightness down) are handled by acpi_ibm.

sysctl dev.acpi_ibm.0.handlerevents='0x04 0x10 0x11'

in sysctl.conf(5):

dev.acpi_ibm.0.handlerevents=0x04\ 0x10\ 0x11

HISTORY

The acpi_ibm device driver first appeared in FreeBSD 6.0.

AUTHORS

The acpi_ibm driver was written by Takanori Watanabe <[email protected]> and later mostly rewritten by Markus Brueffer <[email protected]>. This manual page was written by Christian Brueffer <[email protected]> and Markus Brueffer <[email protected]>.

June 24, 2020

Debian