Subversion Repositories test_project

                     ThinkPad ACPI Extras Driver

                            Version 0.17

                         October 04th, 2007

               Borislav Deianov 

             Henrique de Moraes Holschuh 

                      http://ibm-acpi.sf.net/

This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It

supports various features of these laptops which are accessible

through the ACPI and ACPI EC framework, but not otherwise fully

supported by the generic Linux ACPI drivers.

This driver used to be named ibm-acpi until kernel 2.6.21 and release

0.13-20070314.  It used to be in the drivers/acpi tree, but it was

moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel

2.6.22, and release 0.14.

Status

------

The features currently supported are the following (see below for

detailed description):

        - Fn key combinations

        - Bluetooth enable and disable

        - video output switching, expansion control

        - ThinkLight on and off

        - limited docking and undocking

        - UltraBay eject

        - CMOS control

        - LED control

        - ACPI sounds

        - temperature sensors

        - Experimental: embedded controller register dump

        - LCD brightness control

        - Volume control

        - Fan control and monitoring: fan speed, fan enable/disable

        - Experimental: WAN enable and disable

A compatibility table by model and feature is maintained on the web

site, http://ibm-acpi.sf.net/. I appreciate any success or failure

reports, especially if they add to or correct the compatibility table.

Please include the following information in your report:

        - ThinkPad model name

        - a copy of your DSDT, from /proc/acpi/dsdt

        - a copy of the output of dmidecode, with serial numbers

          and UUIDs masked off

        - which driver features work and which don't

        - the observed behavior of non-working features

Any other comments or patches are also more than welcome.

Installation

------------

If you are compiling this driver as included in the Linux kernel

sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally

enable the CONFIG_THINKPAD_ACPI_BAY option if you want the

thinkpad-specific bay functionality.

Features

--------

The driver exports two different interfaces to userspace, which can be

used to access the features it provides.  One is a legacy procfs-based

interface, which will be removed at some time in the distant future.

The other is a new sysfs-based interface which is not complete yet.

The procfs interface creates the /proc/acpi/ibm directory.  There is a

file under that directory for each feature it supports.  The procfs

interface is mostly frozen, and will change very little if at all: it

will not be extended to add any new functionality in the driver, instead

all new functionality will be implemented on the sysfs interface.

The sysfs interface tries to blend in the generic Linux sysfs subsystems

and classes as much as possible.  Since some of these subsystems are not

yet ready or stabilized, it is expected that this interface will change,

and any and all userspace programs must deal with it.

Notes about the sysfs interface:

Unlike what was done with the procfs interface, correctness when talking

to the sysfs interfaces will be enforced, as will correctness in the

thinkpad-acpi's implementation of sysfs interfaces.

Also, any bugs in the thinkpad-acpi sysfs driver code or in the

thinkpad-acpi's implementation of the sysfs interfaces will be fixed for

maximum correctness, even if that means changing an interface in

non-compatible ways.  As these interfaces mature both in the kernel and

in thinkpad-acpi, such changes should become quite rare.

Applications interfacing to the thinkpad-acpi sysfs interfaces must

follow all sysfs guidelines and correctly process all errors (the sysfs

interface makes extensive use of errors).  File descriptors and open /

close operations to the sysfs inodes must also be properly implemented.

The version of thinkpad-acpi's sysfs interface is exported by the driver

as a driver attribute (see below).

Sysfs driver attributes are on the driver's sysfs attribute space,

for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and

/sys/bus/platform/drivers/thinkpad_hwmon/

Sysfs device attributes are on the thinkpad_acpi device sysfs attribute

space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.

Sysfs device attributes for the sensors and fan are on the

thinkpad_hwmon device's sysfs attribute space, but you should locate it

looking for a hwmon device with the name attribute of "thinkpad".

Driver version

--------------

procfs: /proc/acpi/ibm/driver

sysfs driver attribute: version

The driver name and version. No commands can be written to this file.

Sysfs interface version

-----------------------

sysfs driver attribute: interface_version

Version of the thinkpad-acpi sysfs interface, as an unsigned long

(output in hex format: 0xAAAABBCC), where:

        AAAA - major revision

        BB - minor revision

        CC - bugfix revision

The sysfs interface version changelog for the driver can be found at the

end of this document.  Changes to the sysfs interface done by the kernel

subsystems are not documented here, nor are they tracked by this

attribute.

Changes to the thinkpad-acpi sysfs interface are only considered

non-experimental when they are submitted to Linux mainline, at which

point the changes in this interface are documented and interface_version

may be updated.  If you are using any thinkpad-acpi features not yet

sent to mainline for merging, you do so on your own risk: these features

may disappear, or be implemented in a different and incompatible way by

the time they are merged in Linux mainline.

Changes that are backwards-compatible by nature (e.g. the addition of

attributes that do not change the way the other attributes work) do not

always warrant an update of interface_version.  Therefore, one must

expect that an attribute might not be there, and deal with it properly

(an attribute not being there *is* a valid way to make it clear that a

feature is not available in sysfs).

Hot keys

--------

procfs: /proc/acpi/ibm/hotkey

sysfs device attribute: hotkey_*

In a ThinkPad, the ACPI HKEY handler is responsible for comunicating

some important events and also keyboard hot key presses to the operating

system.  Enabling the hotkey functionality of thinkpad-acpi signals the

firmware that such a driver is present, and modifies how the ThinkPad

firmware will behave in many situations.

The driver enables the hot key feature automatically when loaded.  The

feature can later be disabled and enabled back at runtime.  The driver

will also restore the hot key feature to its previous state and mask

when it is unloaded.

When the hotkey feature is enabled and the hot key mask is set (see

below), the driver will report HKEY events in the following format:

        ibm/hotkey HKEY 00000080 0000xxxx

Some of these events refer to hot key presses, but not all.

The driver will generate events over the input layer for hot keys and

radio switches, and over the ACPI netlink layer for other events.  The

input layer support accepts the standard IOCTLs to remap the keycodes

assigned to each hot key.

The hot key bit mask allows some control over which hot keys generate

events.  If a key is "masked" (bit set to 0 in the mask), the firmware

will handle it.  If it is "unmasked", it signals the firmware that

thinkpad-acpi would prefer to handle it, if the firmware would be so

kind to allow it (and it often doesn't!).

Not all bits in the mask can be modified.  Not all bits that can be

modified do anything.  Not all hot keys can be individually controlled

by the mask.  Some models do not support the mask at all, and in those

models, hot keys cannot be controlled individually.  The behaviour of

the mask is, therefore, higly dependent on the ThinkPad model.

Note that unmasking some keys prevents their default behavior.  For

example, if Fn+F5 is unmasked, that key will no longer enable/disable

Bluetooth by itself.

Note also that not all Fn key combinations are supported through ACPI.

For example, on the X40, the brightness, volume and "Access IBM" buttons

do not generate ACPI events even with this driver.  They *can* be used

through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/

procfs notes:

The following commands can be written to the /proc/acpi/ibm/hotkey file:

        echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature

        echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature

        echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys

        echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys

        ... any other 8-hex-digit mask ...

        echo reset > /proc/acpi/ibm/hotkey -- restore the original mask

sysfs notes:

        hotkey_bios_enabled:

                Returns the status of the hot keys feature when

                thinkpad-acpi was loaded.  Upon module unload, the hot

                key feature status will be restored to this value.

                0: hot keys were disabled

                1: hot keys were enabled (unusual)

        hotkey_bios_mask:

                Returns the hot keys mask when thinkpad-acpi was loaded.

                Upon module unload, the hot keys mask will be restored

                to this value.

        hotkey_enable:

                Enables/disables the hot keys feature, and reports

                current status of the hot keys feature.

                0: disables the hot keys feature / feature disabled

                1: enables the hot keys feature / feature enabled

        hotkey_mask:

                bit mask to enable driver-handling and ACPI event

                generation for each hot key (see above).  Returns the

                current status of the hot keys mask, and allows one to

                modify it.

        hotkey_all_mask:

                bit mask that should enable event reporting for all

                supported hot keys, when echoed to hotkey_mask above.

                Unless you know which events need to be handled

                passively (because the firmware *will* handle them

                anyway), do *not* use hotkey_all_mask.  Use

                hotkey_recommended_mask, instead. You have been warned.

        hotkey_recommended_mask:

                bit mask that should enable event reporting for all

                supported hot keys, except those which are always

                handled by the firmware anyway.  Echo it to

                hotkey_mask above, to use.

        hotkey_radio_sw:

                if the ThinkPad has a hardware radio switch, this

                attribute will read 0 if the switch is in the "radios

                disabled" postition, and 1 if the switch is in the

                "radios enabled" position.

        hotkey_report_mode:

                Returns the state of the procfs ACPI event report mode

                filter for hot keys.  If it is set to 1 (the default),

                all hot key presses are reported both through the input

                layer and also as ACPI events through procfs (but not

                through netlink).  If it is set to 2, hot key presses

                are reported only through the input layer.

                This attribute is read-only in kernels 2.6.23 or later,

                and read-write on earlier kernels.

                May return -EPERM (write access locked out by module

                parameter) or -EACCES (read-only).

input layer notes:

A Hot key is mapped to a single input layer EV_KEY event, possibly

followed by an EV_MSC MSC_SCAN event that shall contain that key's scan

code.  An EV_SYN event will always be generated to mark the end of the

event block.

Do not use the EV_MSC MSC_SCAN events to process keys.  They are to be

used as a helper to remap keys, only.  They are particularly useful when

remapping KEY_UNKNOWN keys.

The events are available in an input device, with the following id:

        Bus:            BUS_HOST

        vendor:         0x1014 (PCI_VENDOR_ID_IBM)  or

                        0x17aa (PCI_VENDOR_ID_LENOVO)

        product:        0x5054 ("TP")

        version:        0x4101

The version will have its LSB incremented if the keymap changes in a

backwards-compatible way.  The MSB shall always be 0x41 for this input

device.  If the MSB is not 0x41, do not use the device as described in

this section, as it is either something else (e.g. another input device

exported by a thinkpad driver, such as HDAPS) or its functionality has

been changed in a non-backwards compatible way.

Adding other event types for other functionalities shall be considered a

backwards-compatible change for this input device.

Thinkpad-acpi Hot Key event map (version 0x4101):

ACPI    Scan

event   code    Key             Notes

0x1001  0x00    FN+F1           -

0x1002  0x01    FN+F2           IBM: battery (rare)

                                Lenovo: Screen lock

0x1003  0x02    FN+F3           Many IBM models always report

                                this hot key, even with hot keys

                                disabled or with Fn+F3 masked

                                off

                                IBM: screen lock

                                Lenovo: battery

0x1004  0x03    FN+F4           Sleep button (ACPI sleep button

                                semanthics, i.e. sleep-to-RAM).

                                It is always generate some kind

                                of event, either the hot key

                                event or a ACPI sleep button

                                event. The firmware may

                                refuse to generate further FN+F4

                                key presses until a S3 or S4 ACPI

                                sleep cycle is performed or some

                                time passes.

0x1005  0x04    FN+F5           Radio.  Enables/disables

                                the internal BlueTooth hardware

                                and W-WAN card if left in control

                                of the firmware.  Does not affect

                                the WLAN card.

                                Should be used to turn on/off all

                                radios (bluetooth+W-WAN+WLAN),

                                really.

0x1006  0x05    FN+F6           -

0x1007  0x06    FN+F7           Video output cycle.

                                Do you feel lucky today?

0x1008  0x07    FN+F8           IBM: toggle screen expand

                                Lenovo: configure ultranav

0x1009  0x08    FN+F9           -

        ..      ..              ..

0x100B  0x0A    FN+F11          -

0x100C  0x0B    FN+F12          Sleep to disk.  You are always

                                supposed to handle it yourself,

                                either through the ACPI event,

                                or through a hotkey event.

                                The firmware may refuse to

                                generate further FN+F4 key

                                press events until a S3 or S4

                                ACPI sleep cycle is performed,

                                or some time passes.

0x100D  0x0C    FN+BACKSPACE    -

0x100E  0x0D    FN+INSERT       -

0x100F  0x0E    FN+DELETE       -

0x1010  0x0F    FN+HOME         Brightness up.  This key is

                                always handled by the firmware

                                in IBM ThinkPads, even when

                                unmasked.  Just leave it alone.

                                For Lenovo ThinkPads with a new

                                BIOS, it has to be handled either

                                by the ACPI OSI, or by userspace.

0x1011  0x10    FN+END          Brightness down.  See brightness

                                up for details.

0x1012  0x11    FN+PGUP         Thinklight toggle.  This key is

                                always handled by the firmware,

                                even when unmasked.

0x1013  0x12    FN+PGDOWN       -

0x1014  0x13    FN+SPACE        Zoom key

0x1015  0x14    VOLUME UP       Internal mixer volume up. This

                                key is always handled by the

                                firmware, even when unmasked.

                                NOTE: Lenovo seems to be changing

                                this.

0x1016  0x15    VOLUME DOWN     Internal mixer volume up. This

                                key is always handled by the

                                firmware, even when unmasked.

                                NOTE: Lenovo seems to be changing

                                this.

0x1017  0x16    MUTE            Mute internal mixer. This

                                key is always handled by the

                                firmware, even when unmasked.

0x1018  0x17    THINKPAD        Thinkpad/Access IBM/Lenovo key

0x1019  0x18    unknown

..      ..      ..

0x1020  0x1F    unknown

The ThinkPad firmware does not allow one to differentiate when most hot

keys are pressed or released (either that, or we don't know how to, yet).

For these keys, the driver generates a set of events for a key press and

immediately issues the same set of events for a key release.  It is

unknown by the driver if the ThinkPad firmware triggered these events on

hot key press or release, but the firmware will do it for either one, not

both.

If a key is mapped to KEY_RESERVED, it generates no input events at all.

If a key is mapped to KEY_UNKNOWN, it generates an input event that

includes an scan code.  If a key is mapped to anything else, it will

generate input device EV_KEY events.

Non hot-key ACPI HKEY event map:

0x5001          Lid closed

0x5002          Lid opened

0x7000          Radio Switch may have changed state

The above events are not propagated by the driver, except for legacy

compatibility purposes when hotkey_report_mode is set to 1.

Compatibility notes:

ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never

supported the input layer, and sent events over the procfs ACPI event

interface.

To avoid sending duplicate events over the input layer and the ACPI

event interface, thinkpad-acpi 0.16 implements a module parameter

(hotkey_report_mode), and also a sysfs device attribute with the same

name.

Make no mistake here: userspace is expected to switch to using the input

layer interface of thinkpad-acpi, together with the ACPI netlink event

interface in kernels 2.6.23 and later, or with the ACPI procfs event

interface in kernels 2.6.22 and earlier.

If no hotkey_report_mode module parameter is specified (or it is set to

zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22

and earlier, also allows one to change the hotkey_report_mode through

sysfs.  In kernels 2.6.23 and later, where the netlink ACPI event

interface is available, hotkey_report_mode cannot be changed through

sysfs (it is read-only).

If the hotkey_report_mode module parameter is set to 1 or 2, it cannot

be changed later through sysfs (any writes will return -EPERM to signal

that hotkey_report_mode was locked.  On 2.6.23 and later, where

hotkey_report_mode cannot be changed at all, writes will return -EACES).

hotkey_report_mode set to 1 makes the driver export through the procfs

ACPI event interface all hot key presses (which are *also* sent to the

input layer).  This is a legacy compatibility behaviour, and it is also

the default mode of operation for the driver.

hotkey_report_mode set to 2 makes the driver filter out the hot key

presses from the procfs ACPI event interface, so these events will only

be sent through the input layer.  Userspace that has been updated to use

the thinkpad-acpi input layer interface should set hotkey_report_mode to

2.

Hot key press events are never sent to the ACPI netlink event interface.

Really up-to-date userspace under kernel 2.6.23 and later is to use the

netlink interface and the input layer interface, and don't bother at all

with hotkey_report_mode.

Bluetooth

---------

procfs: /proc/acpi/ibm/bluetooth

sysfs device attribute: bluetooth_enable

This feature shows the presence and current state of a ThinkPad

Bluetooth device in the internal ThinkPad CDC slot.

Procfs notes:

If Bluetooth is installed, the following commands can be used:

        echo enable > /proc/acpi/ibm/bluetooth

        echo disable > /proc/acpi/ibm/bluetooth

Sysfs notes:

        If the Bluetooth CDC card is installed, it can be enabled /

        disabled through the "bluetooth_enable" thinkpad-acpi device

        attribute, and its current status can also be queried.

        enable:

                0: disables Bluetooth / Bluetooth is disabled

                1: enables Bluetooth / Bluetooth is enabled.

        Note: this interface will be probably be superseeded by the

        generic rfkill class, so it is NOT to be considered stable yet.

Video output control -- /proc/acpi/ibm/video

--------------------------------------------

This feature allows control over the devices used for video output -

LCD, CRT or DVI (if available). The following commands are available:

        echo lcd_enable > /proc/acpi/ibm/video

        echo lcd_disable > /proc/acpi/ibm/video

        echo crt_enable > /proc/acpi/ibm/video

        echo crt_disable > /proc/acpi/ibm/video

        echo dvi_enable > /proc/acpi/ibm/video

        echo dvi_disable > /proc/acpi/ibm/video

        echo auto_enable > /proc/acpi/ibm/video

        echo auto_disable > /proc/acpi/ibm/video

        echo expand_toggle > /proc/acpi/ibm/video

        echo video_switch > /proc/acpi/ibm/video

Each video output device can be enabled or disabled individually.

Reading /proc/acpi/ibm/video shows the status of each device.

Automatic video switching can be enabled or disabled.  When automatic

video switching is enabled, certain events (e.g. opening the lid,

docking or undocking) cause the video output device to change

automatically. While this can be useful, it also causes flickering

and, on the X40, video corruption. By disabling automatic switching,

the flickering or video corruption can be avoided.

The video_switch command cycles through the available video outputs

(it simulates the behavior of Fn-F7).

Video expansion can be toggled through this feature. This controls

whether the display is expanded to fill the entire LCD screen when a

mode with less than full resolution is used. Note that the current

video expansion status cannot be determined through this feature.

Note that on many models (particularly those using Radeon graphics

chips) the X driver configures the video card in a way which prevents

Fn-F7 from working. This also disables the video output switching

features of this driver, as it uses the same ACPI methods as

Fn-F7. Video switching on the console should still work.

UPDATE: There's now a patch for the X.org Radeon driver which

addresses this issue. Some people are reporting success with the patch

while others are still having problems. For more information:

https://bugs.freedesktop.org/show_bug.cgi?id=2000

ThinkLight control -- /proc/acpi/ibm/light

------------------------------------------

The current status of the ThinkLight can be found in this file. A few

models which do not make the status available will show it as

"unknown". The available commands are:

        echo on  > /proc/acpi/ibm/light

        echo off > /proc/acpi/ibm/light

Docking / undocking -- /proc/acpi/ibm/dock

------------------------------------------

Docking and undocking (e.g. with the X4 UltraBase) requires some

actions to be taken by the operating system to safely make or break

the electrical connections with the dock.

The docking feature of this driver generates the following ACPI events:

        ibm/dock GDCK 00000003 00000001 -- eject request

        ibm/dock GDCK 00000003 00000002 -- undocked

        ibm/dock GDCK 00000000 00000003 -- docked

NOTE: These events will only be generated if the laptop was docked

when originally booted. This is due to the current lack of support for

hot plugging of devices in the Linux ACPI framework. If the laptop was

booted while not in the dock, the following message is shown in the

logs:

        Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present

In this case, no dock-related events are generated but the dock and

undock commands described below still work. They can be executed

manually or triggered by Fn key combinations (see the example acpid

configuration files included in the driver tarball package available

on the web site).

When the eject request button on the dock is pressed, the first event

above is generated. The handler for this event should issue the

following command:

        echo undock > /proc/acpi/ibm/dock

After the LED on the dock goes off, it is safe to eject the laptop.

Note: if you pressed this key by mistake, go ahead and eject the

laptop, then dock it back in. Otherwise, the dock may not function as

expected.

When the laptop is docked, the third event above is generated. The

handler for this event should issue the following command to fully

enable the dock:

        echo dock > /proc/acpi/ibm/dock

The contents of the /proc/acpi/ibm/dock file shows the current status

of the dock, as provided by the ACPI framework.

The docking support in this driver does not take care of enabling or

disabling any other devices you may have attached to the dock. For

example, a CD drive plugged into the UltraBase needs to be disabled or

enabled separately. See the provided example acpid configuration files

for how this can be accomplished.

There is no support yet for PCI devices that may be attached to a

docking station, e.g. in the ThinkPad Dock II. The driver currently

does not recognize, enable or disable such devices. This means that

the only docking stations currently supported are the X-series

UltraBase docks and "dumb" port replicators like the Mini Dock (the

latter don't need any ACPI support, actually).

UltraBay eject -- /proc/acpi/ibm/bay

------------------------------------

Inserting or ejecting an UltraBay device requires some actions to be

taken by the operating system to safely make or break the electrical

connections with the device.

This feature generates the following ACPI events:

        ibm/bay MSTR 00000003 00000000 -- eject request

        ibm/bay MSTR 00000001 00000000 -- eject lever inserted

NOTE: These events will only be generated if the UltraBay was present

when the laptop was originally booted (on the X series, the UltraBay

is in the dock, so it may not be present if the laptop was undocked).

This is due to the current lack of support for hot plugging of devices

in the Linux ACPI framework. If the laptop was booted without the

UltraBay, the following message is shown in the logs:

        Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present

In this case, no bay-related events are generated but the eject

command described below still works. It can be executed manually or

triggered by a hot key combination.

Sliding the eject lever generates the first event shown above. The

handler for this event should take whatever actions are necessary to

shut down the device in the UltraBay (e.g. call idectl), then issue

the following command:

        echo eject > /proc/acpi/ibm/bay

After the LED on the UltraBay goes off, it is safe to pull out the

device.

When the eject lever is inserted, the second event above is

generated. The handler for this event should take whatever actions are

necessary to enable the UltraBay device (e.g. call idectl).

The contents of the /proc/acpi/ibm/bay file shows the current status

of the UltraBay, as provided by the ACPI framework.

EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use

this feature, you need to supply the experimental=1 parameter when

loading the module):

These models do not have a button near the UltraBay device to request

a hot eject but rather require the laptop to be put to sleep

(suspend-to-ram) before the bay device is ejected or inserted).

The sequence of steps to eject the device is as follows:

        echo eject > /proc/acpi/ibm/bay

        put the ThinkPad to sleep

        remove the drive

        resume from sleep

        cat /proc/acpi/ibm/bay should show that the drive was removed

On the A3x, both the UltraBay 2000 and UltraBay Plus devices are

supported. Use "eject2" instead of "eject" for the second bay.

Note: the UltraBay eject support on the 600e/x, A22p and A3x is

EXPERIMENTAL and may not work as expected. USE WITH CAUTION!

CMOS control

------------

procfs: /proc/acpi/ibm/cmos

sysfs device attribute: cmos_command

This feature is mostly used internally by the ACPI firmware to keep the legacy

CMOS NVRAM bits in sync with the current machine state, and to record this

state so that the ThinkPad will retain such settings across reboots.

Some of these commands actually perform actions in some ThinkPad models, but

this is expected to disappear more and more in newer models.  As an example, in

a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for

real, but commands 0 to 2 don't control the mixer anymore (they have been

phased out) and just update the NVRAM.

The range of valid cmos command numbers is 0 to 21, but not all have an

effect and the behavior varies from model to model.  Here is the behavior

on the X40 (tpb is the ThinkPad Buttons utility):

        1 - Related to "Volume up" key press

        2 - Related to "Mute on" key press

        3 - Related to "Access IBM" key press

        4 - Related to "LCD brightness up" key pess

        5 - Related to "LCD brightness down" key press

        11 - Related to "toggle screen expansion" key press/function

        12 - Related to "ThinkLight on"

        13 - Related to "ThinkLight off"

        14 - Related to "ThinkLight" key press (toggle thinklight)

The cmos command interface is prone to firmware split-brain problems, as

in newer ThinkPads it is just a compatibility layer.  Do not use it, it is

exported just as a debug tool.

LED control -- /proc/acpi/ibm/led

---------------------------------

Some of the LED indicators can be controlled through this feature. The

available commands are:

        echo ' on' >/proc/acpi/ibm/led

        echo ' off' >/proc/acpi/ibm/led

        echo ' blink' >/proc/acpi/ibm/led

The  range is 0 to 7. The set of LEDs that can be

controlled varies from model to model. Here is the mapping on the X40:

        1 - battery (orange)

        2 - battery (green)

        3 - UltraBase

        4 - UltraBay

        7 - standby

All of the above can be turned on and off and can be made to blink.

ACPI sounds -- /proc/acpi/ibm/beep

----------------------------------

The BEEP method is used internally by the ACPI firmware to provide

audible alerts in various situations. This feature allows the same

sounds to be triggered manually.

The commands are non-negative integer numbers:

        echo  >/proc/acpi/ibm/beep

The valid  range is 0 to 17. Not all numbers trigger sounds

and the sounds vary from model to model. Here is the behavior on the

X40:

        2 - two beeps, pause, third beep ("low battery")

        3 - single beep

        4 - high, followed by low-pitched beep ("unable")

        5 - single beep

        6 - very high, followed by high-pitched beep ("AC/DC")

        7 - high-pitched beep

        9 - three short beeps

        10 - very long beep

        12 - low-pitched beep

        15 - three high-pitched beeps repeating constantly, stop with 0

        16 - one medium-pitched beep repeating constantly, stop with 17

        17 - stop 16

Temperature sensors

-------------------

procfs: /proc/acpi/ibm/thermal

sysfs device attributes: (hwmon "thinkpad") temp*_input

Most ThinkPads include six or more separate temperature sensors but only

expose the CPU temperature through the standard ACPI methods.  This

feature shows readings from up to eight different sensors on older

ThinkPads, and up to sixteen different sensors on newer ThinkPads.

For example, on the X40, a typical output may be:

temperatures:   42 42 45 41 36 -128 33 -128

On the T43/p, a typical output may be:

temperatures:   48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128

The mapping of thermal sensors to physical locations varies depending on

system-board model (and thus, on ThinkPad model).

http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that

tries to track down these locations for various models.

Most (newer?) models seem to follow this pattern:

1:  CPU

2:  (depends on model)

3:  (depends on model)

4:  GPU

5:  Main battery: main sensor

6:  Bay battery: main sensor

7:  Main battery: secondary sensor

8:  Bay battery: secondary sensor

9-15: (depends on model)

For the R51 (source: Thomas Gruber):

2:  Mini-PCI

3:  Internal HDD

For the T43, T43/p (source: Shmidoax/Thinkwiki.org)

http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p

2:  System board, left side (near PCMCIA slot), reported as HDAPS temp

3:  PCMCIA slot

9:  MCH (northbridge) to DRAM Bus

10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI

    card, under touchpad

11: Power regulator, underside of system board, below F2 key

The A31 has a very atypical layout for the thermal sensors

(source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)

1:  CPU

2:  Main Battery: main sensor

3:  Power Converter

4:  Bay Battery: main sensor

5:  MCH (northbridge)

6:  PCMCIA/ambient

7:  Main Battery: secondary sensor

8:  Bay Battery: secondary sensor

Procfs notes:

        Readings from sensors that are not available return -128.

        No commands can be written to this file.

Sysfs notes:

        Sensors that are not available return the ENXIO error.  This

        status may change at runtime, as there are hotplug thermal

        sensors, like those inside the batteries and docks.

        thinkpad-acpi thermal sensors are reported through the hwmon

        subsystem, and follow all of the hwmon guidelines at

        Documentation/hwmon.

EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump

------------------------------------------------------------------------

This feature is marked EXPERIMENTAL because the implementation

directly accesses hardware registers and may not work as expected. USE

WITH CAUTION! To use this feature, you need to supply the

experimental=1 parameter when loading the module.

This feature dumps the values of 256 embedded controller

registers. Values which have changed since the last time the registers

were dumped are marked with a star:

[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump

EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f

EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00

EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00

EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80

EC 0x30:  01  07  1a  00  30  04  00  00 *85  00  00  10  00  50  00  00

EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00

EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03 *bc *02 *bc

EC 0x60: *02 *bc *02  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0x70:  00  00  00  00  00  12  30  40 *24 *26 *2c *27 *20  80 *1f  80

EC 0x80:  00  00  00  06 *37 *0e  03  00  00  00  0e  07  00  00  00  00

EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xa0: *ff  09  ff  09  ff  ff *64  00 *00 *00 *a2  41 *ff *ff *e0  00

EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03

EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a

This feature can be used to determine the register holding the fan

speed on some models. To do that, do the following:

        - make sure the battery is fully charged

        - make sure the fan is running

        - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so

The first step makes sure various charging-related values don't

vary. The second ensures that the fan-related values do vary, since

the fan speed fluctuates a bit. The third will (hopefully) mark the

fan register with a star:

[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump

EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f

EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00

EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00

EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80

EC 0x30:  01  07  1a  00  30  04  00  00  85  00  00  10  00  50  00  00

EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00

EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03  bc  02  bc

EC 0x60:  02  bc  02  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0x70:  00  00  00  00  00  12  30  40  24  27  2c  27  21  80  1f  80

EC 0x80:  00  00  00  06 *be  0d  03  00  00  00  0e  07  00  00  00  00

EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xa0:  ff  09  ff  09  ff  ff  64  00  00  00  a2  41  ff  ff  e0  00

EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00

EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03

EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a

Another set of values that varies often is the temperature

readings. Since temperatures don't change vary fast, you can take

several quick dumps to eliminate them.

You can use a similar method to figure out the meaning of other

embedded controller registers - e.g. make sure nothing else changes

except the charging or discharging battery to determine which

registers contain the current battery capacity, etc. If you experiment

with this, do send me your results (including some complete dumps with

a description of the conditions when they were taken.)

LCD brightness control

----------------------

procfs: /proc/acpi/ibm/brightness

sysfs backlight device "thinkpad_screen"

This feature allows software control of the LCD brightness on ThinkPad

models which don't have a hardware brightness slider.

It has some limitations: the LCD backlight cannot be actually turned on or

off by this interface, and in many ThinkPad models, the "dim while on

battery" functionality will be enabled by the BIOS when this interface is

used, and cannot be controlled.

On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control

has eight brightness levels, ranging from 0 to 7.  Some of the levels

may not be distinct.  Later Lenovo models that implement the ACPI

display backlight brightness control methods have 16 levels, ranging

from 0 to 15.

There are two interfaces to the firmware for direct brightness control,