1 ThinkPad ACPI Extras Driver
6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
8 http://ibm-acpi.sf.net/
11 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
12 supports various features of these laptops which are accessible
13 through the ACPI and ACPI EC framework, but not otherwise fully
14 supported by the generic Linux ACPI drivers.
16 This driver used to be named ibm-acpi until kernel 2.6.21 and release
17 0.13-20070314. It used to be in the drivers/acpi tree, but it was
18 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
19 2.6.22, and release 0.14.
25 The features currently supported are the following (see below for
26 detailed description):
29 - Bluetooth enable and disable
30 - video output switching, expansion control
31 - ThinkLight on and off
32 - limited docking and undocking
38 - Experimental: embedded controller register dump
39 - LCD brightness control
41 - Fan control and monitoring: fan speed, fan enable/disable
42 - Experimental: WAN enable and disable
44 A compatibility table by model and feature is maintained on the web
45 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
46 reports, especially if they add to or correct the compatibility table.
47 Please include the following information in your report:
50 - a copy of your DSDT, from /proc/acpi/dsdt
51 - a copy of the output of dmidecode, with serial numbers
53 - which driver features work and which don't
54 - the observed behavior of non-working features
56 Any other comments or patches are also more than welcome.
62 If you are compiling this driver as included in the Linux kernel
63 sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
64 enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
65 thinkpad-specific bay functionality.
70 The driver exports two different interfaces to userspace, which can be
71 used to access the features it provides. One is a legacy procfs-based
72 interface, which will be removed at some time in the distant future.
73 The other is a new sysfs-based interface which is not complete yet.
75 The procfs interface creates the /proc/acpi/ibm directory. There is a
76 file under that directory for each feature it supports. The procfs
77 interface is mostly frozen, and will change very little if at all: it
78 will not be extended to add any new functionality in the driver, instead
79 all new functionality will be implemented on the sysfs interface.
81 The sysfs interface tries to blend in the generic Linux sysfs subsystems
82 and classes as much as possible. Since some of these subsystems are not
83 yet ready or stabilized, it is expected that this interface will change,
84 and any and all userspace programs must deal with it.
87 Notes about the sysfs interface:
89 Unlike what was done with the procfs interface, correctness when talking
90 to the sysfs interfaces will be enforced, as will correctness in the
91 thinkpad-acpi's implementation of sysfs interfaces.
93 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
94 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
95 maximum correctness, even if that means changing an interface in
96 non-compatible ways. As these interfaces mature both in the kernel and
97 in thinkpad-acpi, such changes should become quite rare.
99 Applications interfacing to the thinkpad-acpi sysfs interfaces must
100 follow all sysfs guidelines and correctly process all errors (the sysfs
101 interface makes extensive use of errors). File descriptors and open /
102 close operations to the sysfs inodes must also be properly implemented.
104 The version of thinkpad-acpi's sysfs interface is exported by the driver
105 as a driver attribute (see below).
107 Sysfs driver attributes are on the driver's sysfs attribute space,
108 for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
109 /sys/bus/platform/drivers/thinkpad_hwmon/
111 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
112 space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
114 Sysfs device attributes for the sensors and fan are on the
115 thinkpad_hwmon device's sysfs attribute space, but you should locate it
116 looking for a hwmon device with the name attribute of "thinkpad".
121 procfs: /proc/acpi/ibm/driver
122 sysfs driver attribute: version
124 The driver name and version. No commands can be written to this file.
126 Sysfs interface version
127 -----------------------
129 sysfs driver attribute: interface_version
131 Version of the thinkpad-acpi sysfs interface, as an unsigned long
132 (output in hex format: 0xAAAABBCC), where:
133 AAAA - major revision
137 The sysfs interface version changelog for the driver can be found at the
138 end of this document. Changes to the sysfs interface done by the kernel
139 subsystems are not documented here, nor are they tracked by this
142 Changes to the thinkpad-acpi sysfs interface are only considered
143 non-experimental when they are submitted to Linux mainline, at which
144 point the changes in this interface are documented and interface_version
145 may be updated. If you are using any thinkpad-acpi features not yet
146 sent to mainline for merging, you do so on your own risk: these features
147 may disappear, or be implemented in a different and incompatible way by
148 the time they are merged in Linux mainline.
150 Changes that are backwards-compatible by nature (e.g. the addition of
151 attributes that do not change the way the other attributes work) do not
152 always warrant an update of interface_version. Therefore, one must
153 expect that an attribute might not be there, and deal with it properly
154 (an attribute not being there *is* a valid way to make it clear that a
155 feature is not available in sysfs).
160 procfs: /proc/acpi/ibm/hotkey
161 sysfs device attribute: hotkey_*
163 In a ThinkPad, the ACPI HKEY handler is responsible for comunicating
164 some important events and also keyboard hot key presses to the operating
165 system. Enabling the hotkey functionality of thinkpad-acpi signals the
166 firmware that such a driver is present, and modifies how the ThinkPad
167 firmware will behave in many situations.
169 The driver enables the hot key feature automatically when loaded. The
170 feature can later be disabled and enabled back at runtime. The driver
171 will also restore the hot key feature to its previous state and mask
174 When the hotkey feature is enabled and the hot key mask is set (see
175 below), the driver will report HKEY events in the following format:
177 ibm/hotkey HKEY 00000080 0000xxxx
179 Some of these events refer to hot key presses, but not all.
181 The driver will generate events over the input layer for hot keys and
182 radio switches, and over the ACPI netlink layer for other events. The
183 input layer support accepts the standard IOCTLs to remap the keycodes
184 assigned to each hot key.
186 The hot key bit mask allows some control over which hot keys generate
187 events. If a key is "masked" (bit set to 0 in the mask), the firmware
188 will handle it. If it is "unmasked", it signals the firmware that
189 thinkpad-acpi would prefer to handle it, if the firmware would be so
190 kind to allow it (and it often doesn't!).
192 Not all bits in the mask can be modified. Not all bits that can be
193 modified do anything. Not all hot keys can be individually controlled
194 by the mask. Some models do not support the mask at all, and in those
195 models, hot keys cannot be controlled individually. The behaviour of
196 the mask is, therefore, higly dependent on the ThinkPad model.
198 Note that unmasking some keys prevents their default behavior. For
199 example, if Fn+F5 is unmasked, that key will no longer enable/disable
202 Note also that not all Fn key combinations are supported through ACPI.
203 For example, on the X40, the brightness, volume and "Access IBM" buttons
204 do not generate ACPI events even with this driver. They *can* be used
205 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
209 The following commands can be written to the /proc/acpi/ibm/hotkey file:
211 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
212 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
213 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
214 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
215 ... any other 8-hex-digit mask ...
216 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
221 Returns the status of the hot keys feature when
222 thinkpad-acpi was loaded. Upon module unload, the hot
223 key feature status will be restored to this value.
225 0: hot keys were disabled
226 1: hot keys were enabled (unusual)
229 Returns the hot keys mask when thinkpad-acpi was loaded.
230 Upon module unload, the hot keys mask will be restored
234 Enables/disables the hot keys feature, and reports
235 current status of the hot keys feature.
237 0: disables the hot keys feature / feature disabled
238 1: enables the hot keys feature / feature enabled
241 bit mask to enable driver-handling and ACPI event
242 generation for each hot key (see above). Returns the
243 current status of the hot keys mask, and allows one to
247 bit mask that should enable event reporting for all
248 supported hot keys, when echoed to hotkey_mask above.
249 Unless you know which events need to be handled
250 passively (because the firmware *will* handle them
251 anyway), do *not* use hotkey_all_mask. Use
252 hotkey_recommended_mask, instead. You have been warned.
254 hotkey_recommended_mask:
255 bit mask that should enable event reporting for all
256 supported hot keys, except those which are always
257 handled by the firmware anyway. Echo it to
258 hotkey_mask above, to use.
261 if the ThinkPad has a hardware radio switch, this
262 attribute will read 0 if the switch is in the "radios
263 disabled" postition, and 1 if the switch is in the
264 "radios enabled" position.
267 Returns the state of the procfs ACPI event report mode
268 filter for hot keys. If it is set to 1 (the default),
269 all hot key presses are reported both through the input
270 layer and also as ACPI events through procfs (but not
271 through netlink). If it is set to 2, hot key presses
272 are reported only through the input layer.
274 This attribute is read-only in kernels 2.6.23 or later,
275 and read-write on earlier kernels.
277 May return -EPERM (write access locked out by module
278 parameter) or -EACCES (read-only).
282 A Hot key is mapped to a single input layer EV_KEY event, possibly
283 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
284 code. An EV_SYN event will always be generated to mark the end of the
287 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
288 used as a helper to remap keys, only. They are particularly useful when
289 remapping KEY_UNKNOWN keys.
291 The events are available in an input device, with the following id:
294 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
295 0x17aa (PCI_VENDOR_ID_LENOVO)
296 product: 0x5054 ("TP")
299 The version will have its LSB incremented if the keymap changes in a
300 backwards-compatible way. The MSB shall always be 0x41 for this input
301 device. If the MSB is not 0x41, do not use the device as described in
302 this section, as it is either something else (e.g. another input device
303 exported by a thinkpad driver, such as HDAPS) or its functionality has
304 been changed in a non-backwards compatible way.
306 Adding other event types for other functionalities shall be considered a
307 backwards-compatible change for this input device.
309 Thinkpad-acpi Hot Key event map (version 0x4101):
315 0x1002 0x01 FN+F2 IBM: battery (rare)
318 0x1003 0x02 FN+F3 Many IBM models always report
319 this hot key, even with hot keys
320 disabled or with Fn+F3 masked
325 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
326 semanthics, i.e. sleep-to-RAM).
327 It is always generate some kind
328 of event, either the hot key
329 event or a ACPI sleep button
330 event. The firmware may
331 refuse to generate further FN+F4
332 key presses until a S3 or S4 ACPI
333 sleep cycle is performed or some
336 0x1005 0x04 FN+F5 Radio. Enables/disables
337 the internal BlueTooth hardware
338 and W-WAN card if left in control
339 of the firmware. Does not affect
341 Should be used to turn on/off all
342 radios (bluetooth+W-WAN+WLAN),
347 0x1007 0x06 FN+F7 Video output cycle.
348 Do you feel lucky today?
350 0x1008 0x07 FN+F8 IBM: toggle screen expand
351 Lenovo: configure ultranav
357 0x100C 0x0B FN+F12 Sleep to disk. You are always
358 supposed to handle it yourself,
359 either through the ACPI event,
360 or through a hotkey event.
361 The firmware may refuse to
362 generate further FN+F4 key
363 press events until a S3 or S4
364 ACPI sleep cycle is performed,
367 0x100D 0x0C FN+BACKSPACE -
368 0x100E 0x0D FN+INSERT -
369 0x100F 0x0E FN+DELETE -
371 0x1010 0x0F FN+HOME Brightness up. This key is
372 always handled by the firmware
373 in IBM ThinkPads, even when
374 unmasked. Just leave it alone.
375 For Lenovo ThinkPads with a new
376 BIOS, it has to be handled either
377 by the ACPI OSI, or by userspace.
378 0x1011 0x10 FN+END Brightness down. See brightness
381 0x1012 0x11 FN+PGUP Thinklight toggle. This key is
382 always handled by the firmware,
385 0x1013 0x12 FN+PGDOWN -
387 0x1014 0x13 FN+SPACE Zoom key
389 0x1015 0x14 VOLUME UP Internal mixer volume up. This
390 key is always handled by the
391 firmware, even when unmasked.
392 NOTE: Lenovo seems to be changing
394 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
395 key is always handled by the
396 firmware, even when unmasked.
397 NOTE: Lenovo seems to be changing
399 0x1017 0x16 MUTE Mute internal mixer. This
400 key is always handled by the
401 firmware, even when unmasked.
403 0x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
409 The ThinkPad firmware does not allow one to differentiate when most hot
410 keys are pressed or released (either that, or we don't know how to, yet).
411 For these keys, the driver generates a set of events for a key press and
412 immediately issues the same set of events for a key release. It is
413 unknown by the driver if the ThinkPad firmware triggered these events on
414 hot key press or release, but the firmware will do it for either one, not
417 If a key is mapped to KEY_RESERVED, it generates no input events at all.
418 If a key is mapped to KEY_UNKNOWN, it generates an input event that
419 includes an scan code. If a key is mapped to anything else, it will
420 generate input device EV_KEY events.
422 Non hot-key ACPI HKEY event map:
425 0x7000 Radio Switch may have changed state
427 The above events are not propagated by the driver, except for legacy
428 compatibility purposes when hotkey_report_mode is set to 1.
432 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
433 supported the input layer, and sent events over the procfs ACPI event
436 To avoid sending duplicate events over the input layer and the ACPI
437 event interface, thinkpad-acpi 0.16 implements a module parameter
438 (hotkey_report_mode), and also a sysfs device attribute with the same
441 Make no mistake here: userspace is expected to switch to using the input
442 layer interface of thinkpad-acpi, together with the ACPI netlink event
443 interface in kernels 2.6.23 and later, or with the ACPI procfs event
444 interface in kernels 2.6.22 and earlier.
446 If no hotkey_report_mode module parameter is specified (or it is set to
447 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
448 and earlier, also allows one to change the hotkey_report_mode through
449 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
450 interface is available, hotkey_report_mode cannot be changed through
451 sysfs (it is read-only).
453 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
454 be changed later through sysfs (any writes will return -EPERM to signal
455 that hotkey_report_mode was locked. On 2.6.23 and later, where
456 hotkey_report_mode cannot be changed at all, writes will return -EACES).
458 hotkey_report_mode set to 1 makes the driver export through the procfs
459 ACPI event interface all hot key presses (which are *also* sent to the
460 input layer). This is a legacy compatibility behaviour, and it is also
461 the default mode of operation for the driver.
463 hotkey_report_mode set to 2 makes the driver filter out the hot key
464 presses from the procfs ACPI event interface, so these events will only
465 be sent through the input layer. Userspace that has been updated to use
466 the thinkpad-acpi input layer interface should set hotkey_report_mode to
469 Hot key press events are never sent to the ACPI netlink event interface.
470 Really up-to-date userspace under kernel 2.6.23 and later is to use the
471 netlink interface and the input layer interface, and don't bother at all
472 with hotkey_report_mode.
478 procfs: /proc/acpi/ibm/bluetooth
479 sysfs device attribute: bluetooth_enable
481 This feature shows the presence and current state of a ThinkPad
482 Bluetooth device in the internal ThinkPad CDC slot.
486 If Bluetooth is installed, the following commands can be used:
488 echo enable > /proc/acpi/ibm/bluetooth
489 echo disable > /proc/acpi/ibm/bluetooth
493 If the Bluetooth CDC card is installed, it can be enabled /
494 disabled through the "bluetooth_enable" thinkpad-acpi device
495 attribute, and its current status can also be queried.
498 0: disables Bluetooth / Bluetooth is disabled
499 1: enables Bluetooth / Bluetooth is enabled.
501 Note: this interface will be probably be superseeded by the
502 generic rfkill class, so it is NOT to be considered stable yet.
504 Video output control -- /proc/acpi/ibm/video
505 --------------------------------------------
507 This feature allows control over the devices used for video output -
508 LCD, CRT or DVI (if available). The following commands are available:
510 echo lcd_enable > /proc/acpi/ibm/video
511 echo lcd_disable > /proc/acpi/ibm/video
512 echo crt_enable > /proc/acpi/ibm/video
513 echo crt_disable > /proc/acpi/ibm/video
514 echo dvi_enable > /proc/acpi/ibm/video
515 echo dvi_disable > /proc/acpi/ibm/video
516 echo auto_enable > /proc/acpi/ibm/video
517 echo auto_disable > /proc/acpi/ibm/video
518 echo expand_toggle > /proc/acpi/ibm/video
519 echo video_switch > /proc/acpi/ibm/video
521 Each video output device can be enabled or disabled individually.
522 Reading /proc/acpi/ibm/video shows the status of each device.
524 Automatic video switching can be enabled or disabled. When automatic
525 video switching is enabled, certain events (e.g. opening the lid,
526 docking or undocking) cause the video output device to change
527 automatically. While this can be useful, it also causes flickering
528 and, on the X40, video corruption. By disabling automatic switching,
529 the flickering or video corruption can be avoided.
531 The video_switch command cycles through the available video outputs
532 (it simulates the behavior of Fn-F7).
534 Video expansion can be toggled through this feature. This controls
535 whether the display is expanded to fill the entire LCD screen when a
536 mode with less than full resolution is used. Note that the current
537 video expansion status cannot be determined through this feature.
539 Note that on many models (particularly those using Radeon graphics
540 chips) the X driver configures the video card in a way which prevents
541 Fn-F7 from working. This also disables the video output switching
542 features of this driver, as it uses the same ACPI methods as
543 Fn-F7. Video switching on the console should still work.
545 UPDATE: There's now a patch for the X.org Radeon driver which
546 addresses this issue. Some people are reporting success with the patch
547 while others are still having problems. For more information:
549 https://bugs.freedesktop.org/show_bug.cgi?id=2000
551 ThinkLight control -- /proc/acpi/ibm/light
552 ------------------------------------------
554 The current status of the ThinkLight can be found in this file. A few
555 models which do not make the status available will show it as
556 "unknown". The available commands are:
558 echo on > /proc/acpi/ibm/light
559 echo off > /proc/acpi/ibm/light
561 Docking / undocking -- /proc/acpi/ibm/dock
562 ------------------------------------------
564 Docking and undocking (e.g. with the X4 UltraBase) requires some
565 actions to be taken by the operating system to safely make or break
566 the electrical connections with the dock.
568 The docking feature of this driver generates the following ACPI events:
570 ibm/dock GDCK 00000003 00000001 -- eject request
571 ibm/dock GDCK 00000003 00000002 -- undocked
572 ibm/dock GDCK 00000000 00000003 -- docked
574 NOTE: These events will only be generated if the laptop was docked
575 when originally booted. This is due to the current lack of support for
576 hot plugging of devices in the Linux ACPI framework. If the laptop was
577 booted while not in the dock, the following message is shown in the
580 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
582 In this case, no dock-related events are generated but the dock and
583 undock commands described below still work. They can be executed
584 manually or triggered by Fn key combinations (see the example acpid
585 configuration files included in the driver tarball package available
588 When the eject request button on the dock is pressed, the first event
589 above is generated. The handler for this event should issue the
592 echo undock > /proc/acpi/ibm/dock
594 After the LED on the dock goes off, it is safe to eject the laptop.
595 Note: if you pressed this key by mistake, go ahead and eject the
596 laptop, then dock it back in. Otherwise, the dock may not function as
599 When the laptop is docked, the third event above is generated. The
600 handler for this event should issue the following command to fully
603 echo dock > /proc/acpi/ibm/dock
605 The contents of the /proc/acpi/ibm/dock file shows the current status
606 of the dock, as provided by the ACPI framework.
608 The docking support in this driver does not take care of enabling or
609 disabling any other devices you may have attached to the dock. For
610 example, a CD drive plugged into the UltraBase needs to be disabled or
611 enabled separately. See the provided example acpid configuration files
612 for how this can be accomplished.
614 There is no support yet for PCI devices that may be attached to a
615 docking station, e.g. in the ThinkPad Dock II. The driver currently
616 does not recognize, enable or disable such devices. This means that
617 the only docking stations currently supported are the X-series
618 UltraBase docks and "dumb" port replicators like the Mini Dock (the
619 latter don't need any ACPI support, actually).
621 UltraBay eject -- /proc/acpi/ibm/bay
622 ------------------------------------
624 Inserting or ejecting an UltraBay device requires some actions to be
625 taken by the operating system to safely make or break the electrical
626 connections with the device.
628 This feature generates the following ACPI events:
630 ibm/bay MSTR 00000003 00000000 -- eject request
631 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
633 NOTE: These events will only be generated if the UltraBay was present
634 when the laptop was originally booted (on the X series, the UltraBay
635 is in the dock, so it may not be present if the laptop was undocked).
636 This is due to the current lack of support for hot plugging of devices
637 in the Linux ACPI framework. If the laptop was booted without the
638 UltraBay, the following message is shown in the logs:
640 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
642 In this case, no bay-related events are generated but the eject
643 command described below still works. It can be executed manually or
644 triggered by a hot key combination.
646 Sliding the eject lever generates the first event shown above. The
647 handler for this event should take whatever actions are necessary to
648 shut down the device in the UltraBay (e.g. call idectl), then issue
649 the following command:
651 echo eject > /proc/acpi/ibm/bay
653 After the LED on the UltraBay goes off, it is safe to pull out the
656 When the eject lever is inserted, the second event above is
657 generated. The handler for this event should take whatever actions are
658 necessary to enable the UltraBay device (e.g. call idectl).
660 The contents of the /proc/acpi/ibm/bay file shows the current status
661 of the UltraBay, as provided by the ACPI framework.
663 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
664 this feature, you need to supply the experimental=1 parameter when
667 These models do not have a button near the UltraBay device to request
668 a hot eject but rather require the laptop to be put to sleep
669 (suspend-to-ram) before the bay device is ejected or inserted).
670 The sequence of steps to eject the device is as follows:
672 echo eject > /proc/acpi/ibm/bay
673 put the ThinkPad to sleep
676 cat /proc/acpi/ibm/bay should show that the drive was removed
678 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
679 supported. Use "eject2" instead of "eject" for the second bay.
681 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
682 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
687 procfs: /proc/acpi/ibm/cmos
688 sysfs device attribute: cmos_command
690 This feature is mostly used internally by the ACPI firmware to keep the legacy
691 CMOS NVRAM bits in sync with the current machine state, and to record this
692 state so that the ThinkPad will retain such settings across reboots.
694 Some of these commands actually perform actions in some ThinkPad models, but
695 this is expected to disappear more and more in newer models. As an example, in
696 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
697 real, but commands 0 to 2 don't control the mixer anymore (they have been
698 phased out) and just update the NVRAM.
700 The range of valid cmos command numbers is 0 to 21, but not all have an
701 effect and the behavior varies from model to model. Here is the behavior
702 on the X40 (tpb is the ThinkPad Buttons utility):
704 0 - Related to "Volume down" key press
705 1 - Related to "Volume up" key press
706 2 - Related to "Mute on" key press
707 3 - Related to "Access IBM" key press
708 4 - Related to "LCD brightness up" key pess
709 5 - Related to "LCD brightness down" key press
710 11 - Related to "toggle screen expansion" key press/function
711 12 - Related to "ThinkLight on"
712 13 - Related to "ThinkLight off"
713 14 - Related to "ThinkLight" key press (toggle thinklight)
715 The cmos command interface is prone to firmware split-brain problems, as
716 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
717 exported just as a debug tool.
719 LED control -- /proc/acpi/ibm/led
720 ---------------------------------
722 Some of the LED indicators can be controlled through this feature. The
723 available commands are:
725 echo '<led number> on' >/proc/acpi/ibm/led
726 echo '<led number> off' >/proc/acpi/ibm/led
727 echo '<led number> blink' >/proc/acpi/ibm/led
729 The <led number> range is 0 to 7. The set of LEDs that can be
730 controlled varies from model to model. Here is the mapping on the X40:
739 All of the above can be turned on and off and can be made to blink.
741 ACPI sounds -- /proc/acpi/ibm/beep
742 ----------------------------------
744 The BEEP method is used internally by the ACPI firmware to provide
745 audible alerts in various situations. This feature allows the same
746 sounds to be triggered manually.
748 The commands are non-negative integer numbers:
750 echo <number> >/proc/acpi/ibm/beep
752 The valid <number> range is 0 to 17. Not all numbers trigger sounds
753 and the sounds vary from model to model. Here is the behavior on the
756 0 - stop a sound in progress (but use 17 to stop 16)
757 2 - two beeps, pause, third beep ("low battery")
759 4 - high, followed by low-pitched beep ("unable")
761 6 - very high, followed by high-pitched beep ("AC/DC")
762 7 - high-pitched beep
763 9 - three short beeps
765 12 - low-pitched beep
766 15 - three high-pitched beeps repeating constantly, stop with 0
767 16 - one medium-pitched beep repeating constantly, stop with 17
773 procfs: /proc/acpi/ibm/thermal
774 sysfs device attributes: (hwmon "thinkpad") temp*_input
776 Most ThinkPads include six or more separate temperature sensors but only
777 expose the CPU temperature through the standard ACPI methods. This
778 feature shows readings from up to eight different sensors on older
779 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
781 For example, on the X40, a typical output may be:
782 temperatures: 42 42 45 41 36 -128 33 -128
784 On the T43/p, a typical output may be:
785 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
787 The mapping of thermal sensors to physical locations varies depending on
788 system-board model (and thus, on ThinkPad model).
790 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
791 tries to track down these locations for various models.
793 Most (newer?) models seem to follow this pattern:
796 2: (depends on model)
797 3: (depends on model)
799 5: Main battery: main sensor
800 6: Bay battery: main sensor
801 7: Main battery: secondary sensor
802 8: Bay battery: secondary sensor
803 9-15: (depends on model)
805 For the R51 (source: Thomas Gruber):
809 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
810 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
811 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
813 9: MCH (northbridge) to DRAM Bus
814 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
816 11: Power regulator, underside of system board, below F2 key
818 The A31 has a very atypical layout for the thermal sensors
819 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
821 2: Main Battery: main sensor
823 4: Bay Battery: main sensor
826 7: Main Battery: secondary sensor
827 8: Bay Battery: secondary sensor
831 Readings from sensors that are not available return -128.
832 No commands can be written to this file.
835 Sensors that are not available return the ENXIO error. This
836 status may change at runtime, as there are hotplug thermal
837 sensors, like those inside the batteries and docks.
839 thinkpad-acpi thermal sensors are reported through the hwmon
840 subsystem, and follow all of the hwmon guidelines at
844 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
845 ------------------------------------------------------------------------
847 This feature is marked EXPERIMENTAL because the implementation
848 directly accesses hardware registers and may not work as expected. USE
849 WITH CAUTION! To use this feature, you need to supply the
850 experimental=1 parameter when loading the module.
852 This feature dumps the values of 256 embedded controller
853 registers. Values which have changed since the last time the registers
854 were dumped are marked with a star:
856 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
857 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
858 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
859 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
860 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
861 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
862 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
863 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
864 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
865 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
866 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
867 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
868 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
869 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
870 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
871 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
872 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
873 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
875 This feature can be used to determine the register holding the fan
876 speed on some models. To do that, do the following:
878 - make sure the battery is fully charged
879 - make sure the fan is running
880 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
882 The first step makes sure various charging-related values don't
883 vary. The second ensures that the fan-related values do vary, since
884 the fan speed fluctuates a bit. The third will (hopefully) mark the
885 fan register with a star:
887 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
888 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
889 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
890 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
891 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
892 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
893 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
894 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
895 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
896 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
897 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
898 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
899 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
900 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
901 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
902 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
903 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
904 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
906 Another set of values that varies often is the temperature
907 readings. Since temperatures don't change vary fast, you can take
908 several quick dumps to eliminate them.
910 You can use a similar method to figure out the meaning of other
911 embedded controller registers - e.g. make sure nothing else changes
912 except the charging or discharging battery to determine which
913 registers contain the current battery capacity, etc. If you experiment
914 with this, do send me your results (including some complete dumps with
915 a description of the conditions when they were taken.)
917 LCD brightness control
918 ----------------------
920 procfs: /proc/acpi/ibm/brightness
921 sysfs backlight device "thinkpad_screen"
923 This feature allows software control of the LCD brightness on ThinkPad
924 models which don't have a hardware brightness slider.
926 It has some limitations: the LCD backlight cannot be actually turned on or
927 off by this interface, and in many ThinkPad models, the "dim while on
928 battery" functionality will be enabled by the BIOS when this interface is
929 used, and cannot be controlled.
931 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
932 has eight brightness levels, ranging from 0 to 7. Some of the levels
933 may not be distinct. Later Lenovo models that implement the ACPI
934 display backlight brightness control methods have 16 levels, ranging
937 There are two interfaces to the firmware for direct brightness control,
938 EC and CMOS. To select which one should be used, use the
939 brightness_mode module parameter: brightness_mode=1 selects EC mode,
940 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
941 and CMOS. The driver tries to autodetect which interface to use.
943 When display backlight brightness controls are available through the
944 standard ACPI interface, it is best to use it instead of this direct
945 ThinkPad-specific interface. The driver will disable its native
946 backlight brightness control interface if it detects that the standard
947 ACPI interface is available in the ThinkPad.
949 The brightness_enable module parameter can be used to control whether
950 the LCD brightness control feature will be enabled when available.
951 brightness_enable=0 forces it to be disabled. brightness_enable=1
952 forces it to be enabled when available, even if the standard ACPI
953 interface is also available.
957 The available commands are:
959 echo up >/proc/acpi/ibm/brightness
960 echo down >/proc/acpi/ibm/brightness
961 echo 'level <level>' >/proc/acpi/ibm/brightness
965 The interface is implemented through the backlight sysfs class, which is
966 poorly documented at this time.
968 Locate the thinkpad_screen device under /sys/class/backlight, and inside
969 it there will be the following attributes:
972 Reads the maximum brightness the hardware can be set to.
973 The minimum is always zero.
976 Reads what brightness the screen is set to at this instant.
979 Writes request the driver to change brightness to the
980 given value. Reads will tell you what brightness the
981 driver is trying to set the display to when "power" is set
982 to zero and the display has not been dimmed by a kernel
983 power management event.
986 power management mode, where 0 is "display on", and 1 to 3
987 will dim the display backlight to brightness level 0
988 because thinkpad-acpi cannot really turn the backlight
989 off. Kernel power management events can temporarily
990 increase the current power management level, i.e. they can
994 Volume control -- /proc/acpi/ibm/volume
995 ---------------------------------------
997 This feature allows volume control on ThinkPad models which don't have
998 a hardware volume knob. The available commands are:
1000 echo up >/proc/acpi/ibm/volume
1001 echo down >/proc/acpi/ibm/volume
1002 echo mute >/proc/acpi/ibm/volume
1003 echo 'level <level>' >/proc/acpi/ibm/volume
1005 The <level> number range is 0 to 15 although not all of them may be
1006 distinct. The unmute the volume after the mute command, use either the
1007 up or down command (the level command will not unmute the volume).
1008 The current volume level and mute state is shown in the file.
1010 Fan control and monitoring: fan speed, fan enable/disable
1011 ---------------------------------------------------------
1013 procfs: /proc/acpi/ibm/fan
1014 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1016 sysfs hwmon driver attributes: fan_watchdog
1018 NOTE NOTE NOTE: fan control operations are disabled by default for
1019 safety reasons. To enable them, the module parameter "fan_control=1"
1020 must be given to thinkpad-acpi.
1022 This feature attempts to show the current fan speed, control mode and
1023 other fan data that might be available. The speed is read directly
1024 from the hardware registers of the embedded controller. This is known
1025 to work on later R, T, X and Z series ThinkPads but may show a bogus
1026 value on other models.
1030 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1031 stops the fan. The higher the level, the higher the fan speed, although
1032 adjacent levels often map to the same fan speed. 7 is the highest
1033 level, where the fan reaches the maximum recommended speed.
1035 Level "auto" means the EC changes the fan level according to some
1036 internal algorithm, usually based on readings from the thermal sensors.
1038 There is also a "full-speed" level, also known as "disengaged" level.
1039 In this level, the EC disables the speed-locked closed-loop fan control,
1040 and drives the fan as fast as it can go, which might exceed hardware
1041 limits, so use this level with caution.
1043 The fan usually ramps up or down slowly from one speed to another, and
1044 it is normal for the EC to take several seconds to react to fan
1045 commands. The full-speed level may take up to two minutes to ramp up to
1046 maximum speed, and in some ThinkPads, the tachometer readings go stale
1047 while the EC is transitioning to the full-speed level.
1049 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1050 monitoring all of the temperature sensor readings and you are ready to
1051 enable it if necessary to avoid overheating.
1053 An enabled fan in level "auto" may stop spinning if the EC decides the
1054 ThinkPad is cool enough and doesn't need the extra airflow. This is
1055 normal, and the EC will spin the fan up if the various thermal readings
1058 On the X40, this seems to depend on the CPU and HDD temperatures.
1059 Specifically, the fan is turned on when either the CPU temperature
1060 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1061 fan is turned off when the CPU temperature drops to 49 degrees and the
1062 HDD temperature drops to 41 degrees. These thresholds cannot
1063 currently be controlled.
1065 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1066 certain conditions are met. It will override any fan programming done
1067 through thinkpad-acpi.
1069 The thinkpad-acpi kernel driver can be programmed to revert the fan
1070 level to a safe setting if userspace does not issue one of the procfs
1071 fan commands: "enable", "disable", "level" or "watchdog", or if there
1072 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1073 set to 1, manual mode) within a configurable amount of time of up to
1074 120 seconds. This functionality is called fan safety watchdog.
1076 Note that the watchdog timer stops after it enables the fan. It will be
1077 rearmed again automatically (using the same interval) when one of the
1078 above mentioned fan commands is received. The fan watchdog is,
1079 therefore, not suitable to protect against fan mode changes made through
1080 means other than the "enable", "disable", and "level" procfs fan
1081 commands, or the hwmon fan control sysfs interface.
1085 The fan may be enabled or disabled with the following commands:
1087 echo enable >/proc/acpi/ibm/fan
1088 echo disable >/proc/acpi/ibm/fan
1090 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1091 will try to place it in a safe level if it is too slow or disabled.
1093 The fan level can be controlled with the command:
1095 echo 'level <level>' > /proc/acpi/ibm/fan
1097 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1098 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1099 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1100 "full-speed", and reports it as "disengaged" for backwards
1103 On the X31 and X40 (and ONLY on those models), the fan speed can be
1104 controlled to a certain degree. Once the fan is running, it can be
1105 forced to run faster or slower with the following command:
1107 echo 'speed <speed>' > /proc/acpi/ibm/fan
1109 The sustainable range of fan speeds on the X40 appears to be from about
1110 3700 to about 7350. Values outside this range either do not have any
1111 effect or the fan speed eventually settles somewhere in that range. The
1112 fan cannot be stopped or started with this command. This functionality
1113 is incomplete, and not available through the sysfs interface.
1115 To program the safety watchdog, use the "watchdog" command.
1117 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1119 If you want to disable the watchdog, use 0 as the interval.
1123 The sysfs interface follows the hwmon subsystem guidelines for the most
1124 part, and the exception is the fan safety watchdog.
1126 Writes to any of the sysfs attributes may return the EINVAL error if
1127 that operation is not supported in a given ThinkPad or if the parameter
1128 is out-of-bounds, and EPERM if it is forbidden. They may also return
1129 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1132 Features not yet implemented by the driver return ENOSYS.
1134 hwmon device attribute pwm1_enable:
1135 0: PWM offline (fan is set to full-speed mode)
1136 1: Manual PWM control (use pwm1 to set fan level)
1137 2: Hardware PWM control (EC "auto" mode)
1138 3: reserved (Software PWM control, not implemented yet)
1140 Modes 0 and 2 are not supported by all ThinkPads, and the
1141 driver is not always able to detect this. If it does know a
1142 mode is unsupported, it will return -EINVAL.
1144 hwmon device attribute pwm1:
1145 Fan level, scaled from the firmware values of 0-7 to the hwmon
1146 scale of 0-255. 0 means fan stopped, 255 means highest normal
1149 This attribute only commands the fan if pmw1_enable is set to 1
1150 (manual PWM control).
1152 hwmon device attribute fan1_input:
1153 Fan tachometer reading, in RPM. May go stale on certain
1154 ThinkPads while the EC transitions the PWM to offline mode,
1155 which can take up to two minutes. May return rubbish on older
1158 hwmon driver attribute fan_watchdog:
1159 Fan safety watchdog timer interval, in seconds. Minimum is
1160 1 second, maximum is 120 seconds. 0 disables the watchdog.
1162 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1164 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1165 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1166 would be the safest choice, though).
1172 procfs: /proc/acpi/ibm/wan
1173 sysfs device attribute: wwan_enable
1175 This feature is marked EXPERIMENTAL because the implementation
1176 directly accesses hardware registers and may not work as expected. USE
1177 WITH CAUTION! To use this feature, you need to supply the
1178 experimental=1 parameter when loading the module.
1180 This feature shows the presence and current state of a W-WAN (Sierra
1181 Wireless EV-DO) device.
1183 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1184 Thinkpad models which come with this module installed.
1188 If the W-WAN card is installed, the following commands can be used:
1190 echo enable > /proc/acpi/ibm/wan
1191 echo disable > /proc/acpi/ibm/wan
1195 If the W-WAN card is installed, it can be enabled /
1196 disabled through the "wwan_enable" thinkpad-acpi device
1197 attribute, and its current status can also be queried.
1200 0: disables WWAN card / WWAN card is disabled
1201 1: enables WWAN card / WWAN card is enabled.
1203 Note: this interface will be probably be superseeded by the
1204 generic rfkill class, so it is NOT to be considered stable yet.
1206 Multiple Commands, Module Parameters
1207 ------------------------------------
1209 Multiple commands can be written to the proc files in one shot by
1210 separating them with commas, for example:
1212 echo enable,0xffff > /proc/acpi/ibm/hotkey
1213 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1215 Commands can also be specified when loading the thinkpad-acpi module,
1218 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1220 Enabling debugging output
1221 -------------------------
1223 The module takes a debug parameter which can be used to selectively
1224 enable various classes of debugging output, for example:
1226 modprobe ibm_acpi debug=0xffff
1228 will enable all debugging output classes. It takes a bitmask, so
1229 to enable more than one output class, just add their values.
1231 Debug bitmask Description
1232 0x0001 Initialization and probing
1235 There is also a kernel build option to enable more debugging
1236 information, which may be necessary to debug driver problems.
1238 The level of debugging information output by the driver can be changed
1239 at runtime through sysfs, using the driver attribute debug_level. The
1240 attribute takes the same bitmask as the debug module parameter above.
1242 Force loading of module
1243 -----------------------
1245 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1246 the module parameter force_load=1. Regardless of whether this works or
1247 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1250 Sysfs interface changelog:
1252 0x000100: Initial sysfs support, as a single platform driver and
1254 0x000200: Hot key support for 32 hot keys, and radio slider switch
1256 0x010000: Hot keys are now handled by default over the input
1257 layer, the radio switch generates input event EV_RADIO,
1258 and the driver enables hot key handling by default in
1261 0x020000: ABI fix: added a separate hwmon platform device and
1262 driver, which must be located by name (thinkpad)
1263 and the hwmon class for libsensors4 (lm-sensors 3)
1264 compatibility. Moved all hwmon attributes to this
1265 new platform device.
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