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diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt new file mode 100644 index 00000000000..f409f4bbdc4 --- /dev/null +++ b/Documentation/thinkpad-acpi.txt @@ -0,0 +1,693 @@ + IBM ThinkPad ACPI Extras Driver + + Version 0.13 + 31 December 2006 + + Borislav Deianov <borislav@users.sf.net> + Henrique de Moraes Holschuh <hmh@hmh.eng.br> + http://ibm-acpi.sf.net/ + + +This is a Linux ACPI driver for the IBM ThinkPad laptops. It supports +various features of these laptops which are accessible through the +ACPI framework but not otherwise fully supported by the generic Linux +ACPI drivers. + + +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 + - Experimental: 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 + - 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_ACPI_IBM option (Power Management / +ACPI / IBM ThinkPad Laptop Extras). + +Features +-------- + +The driver creates the /proc/acpi/ibm directory. There is a file under +that directory for each feature described below. Note that while the +driver is still in the alpha stage, the exact proc file format and +commands supported by the various features is guaranteed to change +frequently. + +Driver version -- /proc/acpi/ibm/driver +--------------------------------------- + +The driver name and version. No commands can be written to this file. + +Hot keys -- /proc/acpi/ibm/hotkey +--------------------------------- + +Without this driver, only the Fn-F4 key (sleep button) generates an +ACPI event. With the driver loaded, the hotkey feature enabled and the +mask set (see below), the various hot keys generate ACPI events in the +following format: + + ibm/hotkey HKEY 00000080 0000xxxx + +The last four digits vary depending on the key combination pressed. +All labeled Fn-Fx key combinations generate distinct events. In +addition, the lid microswitch and some docking station buttons may +also generate such events. + +The following commands can be written to this file: + + echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature + echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature + echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys + echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys + ... any other 4-hex-digit mask ... + echo reset > /proc/acpi/ibm/hotkey -- restore the original mask + +The bit mask allows some control over which hot keys generate ACPI +events. 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. Most recent ThinkPad models honor the +following bits (assuming the hot keys feature has been enabled): + + key bit behavior when set behavior when unset + + Fn-F3 always generates ACPI event + Fn-F4 always generates ACPI event + Fn-F5 0010 generate ACPI event enable/disable Bluetooth + Fn-F7 0040 generate ACPI event switch LCD and external display + Fn-F8 0080 generate ACPI event expand screen or none + Fn-F9 0100 generate ACPI event none + Fn-F12 always generates ACPI event + +Some models do not support all of the above. For example, the T30 does +not support Fn-F5 and Fn-F9. Other models do not support the mask at +all. On those models, hot keys cannot be controlled individually. + +Note that enabling ACPI events for some keys prevents their default +behavior. For example, if events for Fn-F5 are enabled, that key will +no longer enable/disable Bluetooth by itself. This can still be done +from an acpid handler for the ibm/hotkey event. + +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/ + +Bluetooth -- /proc/acpi/ibm/bluetooth +------------------------------------- + +This feature shows the presence and current state of a Bluetooth +device. If Bluetooth is installed, the following commands can be used: + + echo enable > /proc/acpi/ibm/bluetooth + echo disable > /proc/acpi/ibm/bluetooth + +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: ibm_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: ibm_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 -- /proc/acpi/ibm/cmos +----------------------------------- + +This feature is used internally by the ACPI firmware to control the +ThinkLight on most newer ThinkPad models. It may also control LCD +brightness, sounds volume and more, but only on some models. + +The commands are non-negative integer numbers: + + echo 0 >/proc/acpi/ibm/cmos + echo 1 >/proc/acpi/ibm/cmos + echo 2 >/proc/acpi/ibm/cmos + ... + +The range of valid 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): + + 0 - no effect but tpb reports "Volume down" + 1 - no effect but tpb reports "Volume up" + 2 - no effect but tpb reports "Mute on" + 3 - simulate pressing the "Access IBM" button + 4 - LCD brightness up + 5 - LCD brightness down + 11 - toggle screen expansion + 12 - ThinkLight on + 13 - ThinkLight off + 14 - no effect but tpb reports ThinkLight status change + +LED control -- /proc/acpi/ibm/led +--------------------------------- + +Some of the LED indicators can be controlled through this feature. The +available commands are: + + echo '<led number> on' >/proc/acpi/ibm/led + echo '<led number> off' >/proc/acpi/ibm/led + echo '<led number> blink' >/proc/acpi/ibm/led + +The <led number> 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: + + 0 - power + 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 <number> >/proc/acpi/ibm/beep + +The valid <number> 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: + + 0 - stop a sound in progress (but use 17 to stop 16) + 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 -- /proc/acpi/ibm/thermal +--------------------------------------------- + +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 it has experimental support for up to sixteen different +sensors on newer ThinkPads. Readings from sensors that are not available +return -128. + +No commands can be written to this file. + +EXPERIMENTAL: The 16-sensors 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. When EXPERIMENTAL +mode is enabled, reading the first 8 sensors on newer ThinkPads will +also use an new experimental thermal sensor access mode. + +For example, on the X40, a typical output may be: +temperatures: 42 42 45 41 36 -128 33 -128 + +EXPERIMENTAL: 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: 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 + + +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 -- /proc/acpi/ibm/brightness +--------------------------------------------------- + +This feature allows software control of the LCD brightness on ThinkPad +models which don't have a hardware brightness slider. The available +commands are: + + echo up >/proc/acpi/ibm/brightness + echo down >/proc/acpi/ibm/brightness + echo 'level <level>' >/proc/acpi/ibm/brightness + +The <level> number range is 0 to 7, although not all of them may be +distinct. The current brightness level is shown in the file. + +Volume control -- /proc/acpi/ibm/volume +--------------------------------------- + +This feature allows volume control on ThinkPad models which don't have +a hardware volume knob. The available commands are: + + echo up >/proc/acpi/ibm/volume + echo down >/proc/acpi/ibm/volume + echo mute >/proc/acpi/ibm/volume + echo 'level <level>' >/proc/acpi/ibm/volume + +The <level> number range is 0 to 15 although not all of them may be +distinct. The unmute the volume after the mute command, use either the +up or down command (the level command will not unmute the volume). +The current volume level and mute state is shown in the file. + +EXPERIMENTAL: fan speed, fan enable/disable -- /proc/acpi/ibm/fan +----------------------------------------------------------------- + +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 attempts to show the current fan speed, control mode and +other fan data that might be available. The speed is read directly +from the hardware registers of the embedded controller. This is known +to work on later R, T and X series ThinkPads but may show a bogus +value on other models. + +Most ThinkPad fans work in "levels". Level 0 stops the fan. The higher +the level, the higher the fan speed, although adjacent levels often map +to the same fan speed. 7 is the highest level, where the fan reaches +the maximum recommended speed. Level "auto" means the EC changes the +fan level according to some internal algorithm, usually based on +readings from the thermal sensors. Level "disengaged" means the EC +disables the speed-locked closed-loop fan control, and drives the fan as +fast as it can go, which might exceed hardware limits, so use this level +with caution. + +The fan usually ramps up or down slowly from one speed to another, +and it is normal for the EC to take several seconds to react to fan +commands. + +The fan may be enabled or disabled with the following commands: + + echo enable >/proc/acpi/ibm/fan + echo disable >/proc/acpi/ibm/fan + +Placing a fan on level 0 is the same as disabling it. Enabling a fan +will try to place it in a safe level if it is too slow or disabled. + +WARNING WARNING WARNING: do not leave the fan disabled unless you are +monitoring all of the temperature sensor readings and you are ready to +enable it if necessary to avoid overheating. + +An enabled fan in level "auto" may stop spinning if the EC decides the +ThinkPad is cool enough and doesn't need the extra airflow. This is +normal, and the EC will spin the fan up if the varios thermal readings +rise too much. + +On the X40, this seems to depend on the CPU and HDD temperatures. +Specifically, the fan is turned on when either the CPU temperature +climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The +fan is turned off when the CPU temperature drops to 49 degrees and the +HDD temperature drops to 41 degrees. These thresholds cannot +currently be controlled. + +The fan level can be controlled with the command: + + echo 'level <level>' > /proc/acpi/ibm/thermal + +Where <level> is an integer from 0 to 7, or one of the words "auto" +or "disengaged" (without the quotes). Not all ThinkPads support the +"auto" and "disengaged" levels. + +On the X31 and X40 (and ONLY on those models), the fan speed can be +controlled to a certain degree. Once the fan is running, it can be +forced to run faster or slower with the following command: + + echo 'speed <speed>' > /proc/acpi/ibm/thermal + +The sustainable range of fan speeds on the X40 appears to be from +about 3700 to about 7350. Values outside this range either do not have +any effect or the fan speed eventually settles somewhere in that +range. The fan cannot be stopped or started with this command. + +The ThinkPad's ACPI DSDT code will reprogram the fan on its own when +certain conditions are met. It will override any fan programming done +through ibm-acpi. + +The ibm-acpi kernel driver can be programmed to revert the fan level +to a safe setting if userspace does not issue one of the fan commands: +"enable", "disable", "level" or "watchdog" within a configurable +ammount of time. To do this, use the "watchdog" command. + + echo 'watchdog <interval>' > /proc/acpi/ibm/fan + +Interval is the ammount of time in seconds to wait for one of the +above mentioned fan commands before reseting the fan level to a safe +one. If set to zero, the watchdog is disabled (default). When the +watchdog timer runs out, it does the exact equivalent of the "enable" +fan command. + +Note that the watchdog timer stops after it enables the fan. It will +be rearmed again automatically (using the same interval) when one of +the above mentioned fan commands is received. The fan watchdog is, +therefore, not suitable to protect against fan mode changes made +through means other than the "enable", "disable", and "level" fan +commands. + +EXPERIMENTAL: WAN -- /proc/acpi/ibm/wan +--------------------------------------- + +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 shows the presence and current state of a WAN (Sierra +Wireless EV-DO) device. If WAN is installed, the following commands can +be used: + + echo enable > /proc/acpi/ibm/wan + echo disable > /proc/acpi/ibm/wan + +It was tested on a Lenovo Thinkpad X60. It should probably work on other +Thinkpad models which come with this module installed. + +Multiple Commands, Module Parameters +------------------------------------ + +Multiple commands can be written to the proc files in one shot by +separating them with commas, for example: + + echo enable,0xffff > /proc/acpi/ibm/hotkey + echo lcd_disable,crt_enable > /proc/acpi/ibm/video + +Commands can also be specified when loading the ibm_acpi module, for +example: + + modprobe ibm_acpi hotkey=enable,0xffff video=auto_disable + |