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
218 The procfs interface does not support NVRAM polling control. So as to
219 maintain maximum bug-to-bug compatibility, it does not report any masks,
220 nor does it allow one to manipulate the hot key mask when the firmware
221 does not support masks at all, even if NVRAM polling is in use.
226 Returns the status of the hot keys feature when
227 thinkpad-acpi was loaded. Upon module unload, the hot
228 key feature status will be restored to this value.
230 0: hot keys were disabled
231 1: hot keys were enabled (unusual)
234 Returns the hot keys mask when thinkpad-acpi was loaded.
235 Upon module unload, the hot keys mask will be restored
239 Enables/disables the hot keys feature in the ACPI
240 firmware, and reports current status of the hot keys
241 feature. Has no effect on the NVRAM hot key polling
244 0: disables the hot keys feature / feature disabled
245 1: enables the hot keys feature / feature enabled
248 bit mask to enable driver-handling (and depending on
249 the firmware, ACPI event generation) for each hot key
250 (see above). Returns the current status of the hot keys
251 mask, and allows one to modify it.
253 Note: when NVRAM polling is active, the firmware mask
254 will be different from the value returned by
255 hotkey_mask. The driver will retain enabled bits for
256 hotkeys that are under NVRAM polling even if the
257 firmware refuses them, and will not set these bits on
258 the firmware hot key mask.
261 bit mask that should enable event reporting for all
262 supported hot keys, when echoed to hotkey_mask above.
263 Unless you know which events need to be handled
264 passively (because the firmware *will* handle them
265 anyway), do *not* use hotkey_all_mask. Use
266 hotkey_recommended_mask, instead. You have been warned.
268 hotkey_recommended_mask:
269 bit mask that should enable event reporting for all
270 supported hot keys, except those which are always
271 handled by the firmware anyway. Echo it to
272 hotkey_mask above, to use.
275 bit mask that selects which hot keys will the driver
276 poll the NVRAM for. This is auto-detected by the driver
277 based on the capabilities reported by the ACPI firmware,
278 but it can be overridden at runtime.
280 Hot keys whose bits are set in both hotkey_source_mask
281 and also on hotkey_mask are polled for in NVRAM. Only a
282 few hot keys are available through CMOS NVRAM polling.
284 Warning: when in NVRAM mode, the volume up/down/mute
285 keys are synthesized according to changes in the mixer,
286 so you have to use volume up or volume down to unmute,
287 as per the ThinkPad volume mixer user interface. When
288 in ACPI event mode, volume up/down/mute are reported as
289 separate events, but this behaviour may be corrected in
290 future releases of this driver, in which case the
291 ThinkPad volume mixer user interface semanthics will be
295 frequency in Hz for hot key polling. It must be between
296 0 and 25 Hz. Polling is only carried out when strictly
299 Setting hotkey_poll_freq to zero disables polling, and
300 will cause hot key presses that require NVRAM polling
301 to never be reported.
303 Setting hotkey_poll_freq too low will cause repeated
304 pressings of the same hot key to be misreported as a
305 single key press, or to not even be detected at all.
306 The recommended polling frequency is 10Hz.
309 if the ThinkPad has a hardware radio switch, this
310 attribute will read 0 if the switch is in the "radios
311 disabled" postition, and 1 if the switch is in the
312 "radios enabled" position.
315 Returns the state of the procfs ACPI event report mode
316 filter for hot keys. If it is set to 1 (the default),
317 all hot key presses are reported both through the input
318 layer and also as ACPI events through procfs (but not
319 through netlink). If it is set to 2, hot key presses
320 are reported only through the input layer.
322 This attribute is read-only in kernels 2.6.23 or later,
323 and read-write on earlier kernels.
325 May return -EPERM (write access locked out by module
326 parameter) or -EACCES (read-only).
330 A Hot key is mapped to a single input layer EV_KEY event, possibly
331 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
332 code. An EV_SYN event will always be generated to mark the end of the
335 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
336 used as a helper to remap keys, only. They are particularly useful when
337 remapping KEY_UNKNOWN keys.
339 The events are available in an input device, with the following id:
342 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
343 0x17aa (PCI_VENDOR_ID_LENOVO)
344 product: 0x5054 ("TP")
347 The version will have its LSB incremented if the keymap changes in a
348 backwards-compatible way. The MSB shall always be 0x41 for this input
349 device. If the MSB is not 0x41, do not use the device as described in
350 this section, as it is either something else (e.g. another input device
351 exported by a thinkpad driver, such as HDAPS) or its functionality has
352 been changed in a non-backwards compatible way.
354 Adding other event types for other functionalities shall be considered a
355 backwards-compatible change for this input device.
357 Thinkpad-acpi Hot Key event map (version 0x4101):
363 0x1002 0x01 FN+F2 IBM: battery (rare)
366 0x1003 0x02 FN+F3 Many IBM models always report
367 this hot key, even with hot keys
368 disabled or with Fn+F3 masked
373 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
374 semanthics, i.e. sleep-to-RAM).
375 It is always generate some kind
376 of event, either the hot key
377 event or a ACPI sleep button
378 event. The firmware may
379 refuse to generate further FN+F4
380 key presses until a S3 or S4 ACPI
381 sleep cycle is performed or some
384 0x1005 0x04 FN+F5 Radio. Enables/disables
385 the internal BlueTooth hardware
386 and W-WAN card if left in control
387 of the firmware. Does not affect
389 Should be used to turn on/off all
390 radios (bluetooth+W-WAN+WLAN),
395 0x1007 0x06 FN+F7 Video output cycle.
396 Do you feel lucky today?
398 0x1008 0x07 FN+F8 IBM: toggle screen expand
399 Lenovo: configure ultranav
405 0x100C 0x0B FN+F12 Sleep to disk. You are always
406 supposed to handle it yourself,
407 either through the ACPI event,
408 or through a hotkey event.
409 The firmware may refuse to
410 generate further FN+F4 key
411 press events until a S3 or S4
412 ACPI sleep cycle is performed,
415 0x100D 0x0C FN+BACKSPACE -
416 0x100E 0x0D FN+INSERT -
417 0x100F 0x0E FN+DELETE -
419 0x1010 0x0F FN+HOME Brightness up. This key is
420 always handled by the firmware
421 in IBM ThinkPads, even when
422 unmasked. Just leave it alone.
423 For Lenovo ThinkPads with a new
424 BIOS, it has to be handled either
425 by the ACPI OSI, or by userspace.
426 0x1011 0x10 FN+END Brightness down. See brightness
429 0x1012 0x11 FN+PGUP Thinklight toggle. This key is
430 always handled by the firmware,
433 0x1013 0x12 FN+PGDOWN -
435 0x1014 0x13 FN+SPACE Zoom key
437 0x1015 0x14 VOLUME UP Internal mixer volume up. This
438 key is always handled by the
439 firmware, even when unmasked.
440 NOTE: Lenovo seems to be changing
442 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
443 key is always handled by the
444 firmware, even when unmasked.
445 NOTE: Lenovo seems to be changing
447 0x1017 0x16 MUTE Mute internal mixer. This
448 key is always handled by the
449 firmware, even when unmasked.
451 0x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
457 The ThinkPad firmware does not allow one to differentiate when most hot
458 keys are pressed or released (either that, or we don't know how to, yet).
459 For these keys, the driver generates a set of events for a key press and
460 immediately issues the same set of events for a key release. It is
461 unknown by the driver if the ThinkPad firmware triggered these events on
462 hot key press or release, but the firmware will do it for either one, not
465 If a key is mapped to KEY_RESERVED, it generates no input events at all.
466 If a key is mapped to KEY_UNKNOWN, it generates an input event that
467 includes an scan code. If a key is mapped to anything else, it will
468 generate input device EV_KEY events.
470 Non hot-key ACPI HKEY event map:
473 0x7000 Radio Switch may have changed state
475 The above events are not propagated by the driver, except for legacy
476 compatibility purposes when hotkey_report_mode is set to 1.
480 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
481 supported the input layer, and sent events over the procfs ACPI event
484 To avoid sending duplicate events over the input layer and the ACPI
485 event interface, thinkpad-acpi 0.16 implements a module parameter
486 (hotkey_report_mode), and also a sysfs device attribute with the same
489 Make no mistake here: userspace is expected to switch to using the input
490 layer interface of thinkpad-acpi, together with the ACPI netlink event
491 interface in kernels 2.6.23 and later, or with the ACPI procfs event
492 interface in kernels 2.6.22 and earlier.
494 If no hotkey_report_mode module parameter is specified (or it is set to
495 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
496 and earlier, also allows one to change the hotkey_report_mode through
497 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
498 interface is available, hotkey_report_mode cannot be changed through
499 sysfs (it is read-only).
501 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
502 be changed later through sysfs (any writes will return -EPERM to signal
503 that hotkey_report_mode was locked. On 2.6.23 and later, where
504 hotkey_report_mode cannot be changed at all, writes will return -EACES).
506 hotkey_report_mode set to 1 makes the driver export through the procfs
507 ACPI event interface all hot key presses (which are *also* sent to the
508 input layer). This is a legacy compatibility behaviour, and it is also
509 the default mode of operation for the driver.
511 hotkey_report_mode set to 2 makes the driver filter out the hot key
512 presses from the procfs ACPI event interface, so these events will only
513 be sent through the input layer. Userspace that has been updated to use
514 the thinkpad-acpi input layer interface should set hotkey_report_mode to
517 Hot key press events are never sent to the ACPI netlink event interface.
518 Really up-to-date userspace under kernel 2.6.23 and later is to use the
519 netlink interface and the input layer interface, and don't bother at all
520 with hotkey_report_mode.
526 procfs: /proc/acpi/ibm/bluetooth
527 sysfs device attribute: bluetooth_enable
529 This feature shows the presence and current state of a ThinkPad
530 Bluetooth device in the internal ThinkPad CDC slot.
534 If Bluetooth is installed, the following commands can be used:
536 echo enable > /proc/acpi/ibm/bluetooth
537 echo disable > /proc/acpi/ibm/bluetooth
541 If the Bluetooth CDC card is installed, it can be enabled /
542 disabled through the "bluetooth_enable" thinkpad-acpi device
543 attribute, and its current status can also be queried.
546 0: disables Bluetooth / Bluetooth is disabled
547 1: enables Bluetooth / Bluetooth is enabled.
549 Note: this interface will be probably be superseeded by the
550 generic rfkill class, so it is NOT to be considered stable yet.
552 Video output control -- /proc/acpi/ibm/video
553 --------------------------------------------
555 This feature allows control over the devices used for video output -
556 LCD, CRT or DVI (if available). The following commands are available:
558 echo lcd_enable > /proc/acpi/ibm/video
559 echo lcd_disable > /proc/acpi/ibm/video
560 echo crt_enable > /proc/acpi/ibm/video
561 echo crt_disable > /proc/acpi/ibm/video
562 echo dvi_enable > /proc/acpi/ibm/video
563 echo dvi_disable > /proc/acpi/ibm/video
564 echo auto_enable > /proc/acpi/ibm/video
565 echo auto_disable > /proc/acpi/ibm/video
566 echo expand_toggle > /proc/acpi/ibm/video
567 echo video_switch > /proc/acpi/ibm/video
569 Each video output device can be enabled or disabled individually.
570 Reading /proc/acpi/ibm/video shows the status of each device.
572 Automatic video switching can be enabled or disabled. When automatic
573 video switching is enabled, certain events (e.g. opening the lid,
574 docking or undocking) cause the video output device to change
575 automatically. While this can be useful, it also causes flickering
576 and, on the X40, video corruption. By disabling automatic switching,
577 the flickering or video corruption can be avoided.
579 The video_switch command cycles through the available video outputs
580 (it simulates the behavior of Fn-F7).
582 Video expansion can be toggled through this feature. This controls
583 whether the display is expanded to fill the entire LCD screen when a
584 mode with less than full resolution is used. Note that the current
585 video expansion status cannot be determined through this feature.
587 Note that on many models (particularly those using Radeon graphics
588 chips) the X driver configures the video card in a way which prevents
589 Fn-F7 from working. This also disables the video output switching
590 features of this driver, as it uses the same ACPI methods as
591 Fn-F7. Video switching on the console should still work.
593 UPDATE: There's now a patch for the X.org Radeon driver which
594 addresses this issue. Some people are reporting success with the patch
595 while others are still having problems. For more information:
597 https://bugs.freedesktop.org/show_bug.cgi?id=2000
599 ThinkLight control -- /proc/acpi/ibm/light
600 ------------------------------------------
602 The current status of the ThinkLight can be found in this file. A few
603 models which do not make the status available will show it as
604 "unknown". The available commands are:
606 echo on > /proc/acpi/ibm/light
607 echo off > /proc/acpi/ibm/light
609 Docking / undocking -- /proc/acpi/ibm/dock
610 ------------------------------------------
612 Docking and undocking (e.g. with the X4 UltraBase) requires some
613 actions to be taken by the operating system to safely make or break
614 the electrical connections with the dock.
616 The docking feature of this driver generates the following ACPI events:
618 ibm/dock GDCK 00000003 00000001 -- eject request
619 ibm/dock GDCK 00000003 00000002 -- undocked
620 ibm/dock GDCK 00000000 00000003 -- docked
622 NOTE: These events will only be generated if the laptop was docked
623 when originally booted. This is due to the current lack of support for
624 hot plugging of devices in the Linux ACPI framework. If the laptop was
625 booted while not in the dock, the following message is shown in the
628 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
630 In this case, no dock-related events are generated but the dock and
631 undock commands described below still work. They can be executed
632 manually or triggered by Fn key combinations (see the example acpid
633 configuration files included in the driver tarball package available
636 When the eject request button on the dock is pressed, the first event
637 above is generated. The handler for this event should issue the
640 echo undock > /proc/acpi/ibm/dock
642 After the LED on the dock goes off, it is safe to eject the laptop.
643 Note: if you pressed this key by mistake, go ahead and eject the
644 laptop, then dock it back in. Otherwise, the dock may not function as
647 When the laptop is docked, the third event above is generated. The
648 handler for this event should issue the following command to fully
651 echo dock > /proc/acpi/ibm/dock
653 The contents of the /proc/acpi/ibm/dock file shows the current status
654 of the dock, as provided by the ACPI framework.
656 The docking support in this driver does not take care of enabling or
657 disabling any other devices you may have attached to the dock. For
658 example, a CD drive plugged into the UltraBase needs to be disabled or
659 enabled separately. See the provided example acpid configuration files
660 for how this can be accomplished.
662 There is no support yet for PCI devices that may be attached to a
663 docking station, e.g. in the ThinkPad Dock II. The driver currently
664 does not recognize, enable or disable such devices. This means that
665 the only docking stations currently supported are the X-series
666 UltraBase docks and "dumb" port replicators like the Mini Dock (the
667 latter don't need any ACPI support, actually).
669 UltraBay eject -- /proc/acpi/ibm/bay
670 ------------------------------------
672 Inserting or ejecting an UltraBay device requires some actions to be
673 taken by the operating system to safely make or break the electrical
674 connections with the device.
676 This feature generates the following ACPI events:
678 ibm/bay MSTR 00000003 00000000 -- eject request
679 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
681 NOTE: These events will only be generated if the UltraBay was present
682 when the laptop was originally booted (on the X series, the UltraBay
683 is in the dock, so it may not be present if the laptop was undocked).
684 This is due to the current lack of support for hot plugging of devices
685 in the Linux ACPI framework. If the laptop was booted without the
686 UltraBay, the following message is shown in the logs:
688 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
690 In this case, no bay-related events are generated but the eject
691 command described below still works. It can be executed manually or
692 triggered by a hot key combination.
694 Sliding the eject lever generates the first event shown above. The
695 handler for this event should take whatever actions are necessary to
696 shut down the device in the UltraBay (e.g. call idectl), then issue
697 the following command:
699 echo eject > /proc/acpi/ibm/bay
701 After the LED on the UltraBay goes off, it is safe to pull out the
704 When the eject lever is inserted, the second event above is
705 generated. The handler for this event should take whatever actions are
706 necessary to enable the UltraBay device (e.g. call idectl).
708 The contents of the /proc/acpi/ibm/bay file shows the current status
709 of the UltraBay, as provided by the ACPI framework.
711 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
712 this feature, you need to supply the experimental=1 parameter when
715 These models do not have a button near the UltraBay device to request
716 a hot eject but rather require the laptop to be put to sleep
717 (suspend-to-ram) before the bay device is ejected or inserted).
718 The sequence of steps to eject the device is as follows:
720 echo eject > /proc/acpi/ibm/bay
721 put the ThinkPad to sleep
724 cat /proc/acpi/ibm/bay should show that the drive was removed
726 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
727 supported. Use "eject2" instead of "eject" for the second bay.
729 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
730 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
735 procfs: /proc/acpi/ibm/cmos
736 sysfs device attribute: cmos_command
738 This feature is mostly used internally by the ACPI firmware to keep the legacy
739 CMOS NVRAM bits in sync with the current machine state, and to record this
740 state so that the ThinkPad will retain such settings across reboots.
742 Some of these commands actually perform actions in some ThinkPad models, but
743 this is expected to disappear more and more in newer models. As an example, in
744 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
745 real, but commands 0 to 2 don't control the mixer anymore (they have been
746 phased out) and just update the NVRAM.
748 The range of valid cmos command numbers is 0 to 21, but not all have an
749 effect and the behavior varies from model to model. Here is the behavior
750 on the X40 (tpb is the ThinkPad Buttons utility):
752 0 - Related to "Volume down" key press
753 1 - Related to "Volume up" key press
754 2 - Related to "Mute on" key press
755 3 - Related to "Access IBM" key press
756 4 - Related to "LCD brightness up" key pess
757 5 - Related to "LCD brightness down" key press
758 11 - Related to "toggle screen expansion" key press/function
759 12 - Related to "ThinkLight on"
760 13 - Related to "ThinkLight off"
761 14 - Related to "ThinkLight" key press (toggle thinklight)
763 The cmos command interface is prone to firmware split-brain problems, as
764 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
765 exported just as a debug tool.
767 LED control -- /proc/acpi/ibm/led
768 ---------------------------------
770 Some of the LED indicators can be controlled through this feature. The
771 available commands are:
773 echo '<led number> on' >/proc/acpi/ibm/led
774 echo '<led number> off' >/proc/acpi/ibm/led
775 echo '<led number> blink' >/proc/acpi/ibm/led
777 The <led number> range is 0 to 7. The set of LEDs that can be
778 controlled varies from model to model. Here is the mapping on the X40:
787 All of the above can be turned on and off and can be made to blink.
789 ACPI sounds -- /proc/acpi/ibm/beep
790 ----------------------------------
792 The BEEP method is used internally by the ACPI firmware to provide
793 audible alerts in various situations. This feature allows the same
794 sounds to be triggered manually.
796 The commands are non-negative integer numbers:
798 echo <number> >/proc/acpi/ibm/beep
800 The valid <number> range is 0 to 17. Not all numbers trigger sounds
801 and the sounds vary from model to model. Here is the behavior on the
804 0 - stop a sound in progress (but use 17 to stop 16)
805 2 - two beeps, pause, third beep ("low battery")
807 4 - high, followed by low-pitched beep ("unable")
809 6 - very high, followed by high-pitched beep ("AC/DC")
810 7 - high-pitched beep
811 9 - three short beeps
813 12 - low-pitched beep
814 15 - three high-pitched beeps repeating constantly, stop with 0
815 16 - one medium-pitched beep repeating constantly, stop with 17
821 procfs: /proc/acpi/ibm/thermal
822 sysfs device attributes: (hwmon "thinkpad") temp*_input
824 Most ThinkPads include six or more separate temperature sensors but only
825 expose the CPU temperature through the standard ACPI methods. This
826 feature shows readings from up to eight different sensors on older
827 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
829 For example, on the X40, a typical output may be:
830 temperatures: 42 42 45 41 36 -128 33 -128
832 On the T43/p, a typical output may be:
833 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
835 The mapping of thermal sensors to physical locations varies depending on
836 system-board model (and thus, on ThinkPad model).
838 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
839 tries to track down these locations for various models.
841 Most (newer?) models seem to follow this pattern:
844 2: (depends on model)
845 3: (depends on model)
847 5: Main battery: main sensor
848 6: Bay battery: main sensor
849 7: Main battery: secondary sensor
850 8: Bay battery: secondary sensor
851 9-15: (depends on model)
853 For the R51 (source: Thomas Gruber):
857 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
858 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
859 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
861 9: MCH (northbridge) to DRAM Bus
862 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
864 11: Power regulator, underside of system board, below F2 key
866 The A31 has a very atypical layout for the thermal sensors
867 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
869 2: Main Battery: main sensor
871 4: Bay Battery: main sensor
874 7: Main Battery: secondary sensor
875 8: Bay Battery: secondary sensor
879 Readings from sensors that are not available return -128.
880 No commands can be written to this file.
883 Sensors that are not available return the ENXIO error. This
884 status may change at runtime, as there are hotplug thermal
885 sensors, like those inside the batteries and docks.
887 thinkpad-acpi thermal sensors are reported through the hwmon
888 subsystem, and follow all of the hwmon guidelines at
892 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
893 ------------------------------------------------------------------------
895 This feature is marked EXPERIMENTAL because the implementation
896 directly accesses hardware registers and may not work as expected. USE
897 WITH CAUTION! To use this feature, you need to supply the
898 experimental=1 parameter when loading the module.
900 This feature dumps the values of 256 embedded controller
901 registers. Values which have changed since the last time the registers
902 were dumped are marked with a star:
904 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
905 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
906 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
907 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
908 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
909 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
910 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
911 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
912 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
913 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
914 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
915 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
916 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
917 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
918 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
919 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
920 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
921 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
923 This feature can be used to determine the register holding the fan
924 speed on some models. To do that, do the following:
926 - make sure the battery is fully charged
927 - make sure the fan is running
928 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
930 The first step makes sure various charging-related values don't
931 vary. The second ensures that the fan-related values do vary, since
932 the fan speed fluctuates a bit. The third will (hopefully) mark the
933 fan register with a star:
935 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
936 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
937 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
938 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
939 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
940 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
941 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
942 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
943 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
944 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
945 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
946 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
947 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
948 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
949 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
950 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
951 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
952 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
954 Another set of values that varies often is the temperature
955 readings. Since temperatures don't change vary fast, you can take
956 several quick dumps to eliminate them.
958 You can use a similar method to figure out the meaning of other
959 embedded controller registers - e.g. make sure nothing else changes
960 except the charging or discharging battery to determine which
961 registers contain the current battery capacity, etc. If you experiment
962 with this, do send me your results (including some complete dumps with
963 a description of the conditions when they were taken.)
965 LCD brightness control
966 ----------------------
968 procfs: /proc/acpi/ibm/brightness
969 sysfs backlight device "thinkpad_screen"
971 This feature allows software control of the LCD brightness on ThinkPad
972 models which don't have a hardware brightness slider.
974 It has some limitations: the LCD backlight cannot be actually turned on or
975 off by this interface, and in many ThinkPad models, the "dim while on
976 battery" functionality will be enabled by the BIOS when this interface is
977 used, and cannot be controlled.
979 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
980 has eight brightness levels, ranging from 0 to 7. Some of the levels
981 may not be distinct. Later Lenovo models that implement the ACPI
982 display backlight brightness control methods have 16 levels, ranging
985 There are two interfaces to the firmware for direct brightness control,
986 EC and CMOS. To select which one should be used, use the
987 brightness_mode module parameter: brightness_mode=1 selects EC mode,
988 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
989 and CMOS. The driver tries to autodetect which interface to use.
991 When display backlight brightness controls are available through the
992 standard ACPI interface, it is best to use it instead of this direct
993 ThinkPad-specific interface. The driver will disable its native
994 backlight brightness control interface if it detects that the standard
995 ACPI interface is available in the ThinkPad.
997 The brightness_enable module parameter can be used to control whether
998 the LCD brightness control feature will be enabled when available.
999 brightness_enable=0 forces it to be disabled. brightness_enable=1
1000 forces it to be enabled when available, even if the standard ACPI
1001 interface is also available.
1005 The available commands are:
1007 echo up >/proc/acpi/ibm/brightness
1008 echo down >/proc/acpi/ibm/brightness
1009 echo 'level <level>' >/proc/acpi/ibm/brightness
1013 The interface is implemented through the backlight sysfs class, which is
1014 poorly documented at this time.
1016 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1017 it there will be the following attributes:
1020 Reads the maximum brightness the hardware can be set to.
1021 The minimum is always zero.
1024 Reads what brightness the screen is set to at this instant.
1027 Writes request the driver to change brightness to the
1028 given value. Reads will tell you what brightness the
1029 driver is trying to set the display to when "power" is set
1030 to zero and the display has not been dimmed by a kernel
1031 power management event.
1034 power management mode, where 0 is "display on", and 1 to 3
1035 will dim the display backlight to brightness level 0
1036 because thinkpad-acpi cannot really turn the backlight
1037 off. Kernel power management events can temporarily
1038 increase the current power management level, i.e. they can
1042 Volume control -- /proc/acpi/ibm/volume
1043 ---------------------------------------
1045 This feature allows volume control on ThinkPad models which don't have
1046 a hardware volume knob. The available commands are:
1048 echo up >/proc/acpi/ibm/volume
1049 echo down >/proc/acpi/ibm/volume
1050 echo mute >/proc/acpi/ibm/volume
1051 echo 'level <level>' >/proc/acpi/ibm/volume
1053 The <level> number range is 0 to 15 although not all of them may be
1054 distinct. The unmute the volume after the mute command, use either the
1055 up or down command (the level command will not unmute the volume).
1056 The current volume level and mute state is shown in the file.
1058 Fan control and monitoring: fan speed, fan enable/disable
1059 ---------------------------------------------------------
1061 procfs: /proc/acpi/ibm/fan
1062 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1064 sysfs hwmon driver attributes: fan_watchdog
1066 NOTE NOTE NOTE: fan control operations are disabled by default for
1067 safety reasons. To enable them, the module parameter "fan_control=1"
1068 must be given to thinkpad-acpi.
1070 This feature attempts to show the current fan speed, control mode and
1071 other fan data that might be available. The speed is read directly
1072 from the hardware registers of the embedded controller. This is known
1073 to work on later R, T, X and Z series ThinkPads but may show a bogus
1074 value on other models.
1078 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1079 stops the fan. The higher the level, the higher the fan speed, although
1080 adjacent levels often map to the same fan speed. 7 is the highest
1081 level, where the fan reaches the maximum recommended speed.
1083 Level "auto" means the EC changes the fan level according to some
1084 internal algorithm, usually based on readings from the thermal sensors.
1086 There is also a "full-speed" level, also known as "disengaged" level.
1087 In this level, the EC disables the speed-locked closed-loop fan control,
1088 and drives the fan as fast as it can go, which might exceed hardware
1089 limits, so use this level with caution.
1091 The fan usually ramps up or down slowly from one speed to another, and
1092 it is normal for the EC to take several seconds to react to fan
1093 commands. The full-speed level may take up to two minutes to ramp up to
1094 maximum speed, and in some ThinkPads, the tachometer readings go stale
1095 while the EC is transitioning to the full-speed level.
1097 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1098 monitoring all of the temperature sensor readings and you are ready to
1099 enable it if necessary to avoid overheating.
1101 An enabled fan in level "auto" may stop spinning if the EC decides the
1102 ThinkPad is cool enough and doesn't need the extra airflow. This is
1103 normal, and the EC will spin the fan up if the various thermal readings
1106 On the X40, this seems to depend on the CPU and HDD temperatures.
1107 Specifically, the fan is turned on when either the CPU temperature
1108 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1109 fan is turned off when the CPU temperature drops to 49 degrees and the
1110 HDD temperature drops to 41 degrees. These thresholds cannot
1111 currently be controlled.
1113 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1114 certain conditions are met. It will override any fan programming done
1115 through thinkpad-acpi.
1117 The thinkpad-acpi kernel driver can be programmed to revert the fan
1118 level to a safe setting if userspace does not issue one of the procfs
1119 fan commands: "enable", "disable", "level" or "watchdog", or if there
1120 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1121 set to 1, manual mode) within a configurable amount of time of up to
1122 120 seconds. This functionality is called fan safety watchdog.
1124 Note that the watchdog timer stops after it enables the fan. It will be
1125 rearmed again automatically (using the same interval) when one of the
1126 above mentioned fan commands is received. The fan watchdog is,
1127 therefore, not suitable to protect against fan mode changes made through
1128 means other than the "enable", "disable", and "level" procfs fan
1129 commands, or the hwmon fan control sysfs interface.
1133 The fan may be enabled or disabled with the following commands:
1135 echo enable >/proc/acpi/ibm/fan
1136 echo disable >/proc/acpi/ibm/fan
1138 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1139 will try to place it in a safe level if it is too slow or disabled.
1141 The fan level can be controlled with the command:
1143 echo 'level <level>' > /proc/acpi/ibm/fan
1145 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1146 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1147 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1148 "full-speed", and reports it as "disengaged" for backwards
1151 On the X31 and X40 (and ONLY on those models), the fan speed can be
1152 controlled to a certain degree. Once the fan is running, it can be
1153 forced to run faster or slower with the following command:
1155 echo 'speed <speed>' > /proc/acpi/ibm/fan
1157 The sustainable range of fan speeds on the X40 appears to be from about
1158 3700 to about 7350. Values outside this range either do not have any
1159 effect or the fan speed eventually settles somewhere in that range. The
1160 fan cannot be stopped or started with this command. This functionality
1161 is incomplete, and not available through the sysfs interface.
1163 To program the safety watchdog, use the "watchdog" command.
1165 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1167 If you want to disable the watchdog, use 0 as the interval.
1171 The sysfs interface follows the hwmon subsystem guidelines for the most
1172 part, and the exception is the fan safety watchdog.
1174 Writes to any of the sysfs attributes may return the EINVAL error if
1175 that operation is not supported in a given ThinkPad or if the parameter
1176 is out-of-bounds, and EPERM if it is forbidden. They may also return
1177 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1180 Features not yet implemented by the driver return ENOSYS.
1182 hwmon device attribute pwm1_enable:
1183 0: PWM offline (fan is set to full-speed mode)
1184 1: Manual PWM control (use pwm1 to set fan level)
1185 2: Hardware PWM control (EC "auto" mode)
1186 3: reserved (Software PWM control, not implemented yet)
1188 Modes 0 and 2 are not supported by all ThinkPads, and the
1189 driver is not always able to detect this. If it does know a
1190 mode is unsupported, it will return -EINVAL.
1192 hwmon device attribute pwm1:
1193 Fan level, scaled from the firmware values of 0-7 to the hwmon
1194 scale of 0-255. 0 means fan stopped, 255 means highest normal
1197 This attribute only commands the fan if pmw1_enable is set to 1
1198 (manual PWM control).
1200 hwmon device attribute fan1_input:
1201 Fan tachometer reading, in RPM. May go stale on certain
1202 ThinkPads while the EC transitions the PWM to offline mode,
1203 which can take up to two minutes. May return rubbish on older
1206 hwmon driver attribute fan_watchdog:
1207 Fan safety watchdog timer interval, in seconds. Minimum is
1208 1 second, maximum is 120 seconds. 0 disables the watchdog.
1210 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1212 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1213 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1214 would be the safest choice, though).
1220 procfs: /proc/acpi/ibm/wan
1221 sysfs device attribute: wwan_enable
1223 This feature is marked EXPERIMENTAL because the implementation
1224 directly accesses hardware registers and may not work as expected. USE
1225 WITH CAUTION! To use this feature, you need to supply the
1226 experimental=1 parameter when loading the module.
1228 This feature shows the presence and current state of a W-WAN (Sierra
1229 Wireless EV-DO) device.
1231 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1232 Thinkpad models which come with this module installed.
1236 If the W-WAN card is installed, the following commands can be used:
1238 echo enable > /proc/acpi/ibm/wan
1239 echo disable > /proc/acpi/ibm/wan
1243 If the W-WAN card is installed, it can be enabled /
1244 disabled through the "wwan_enable" thinkpad-acpi device
1245 attribute, and its current status can also be queried.
1248 0: disables WWAN card / WWAN card is disabled
1249 1: enables WWAN card / WWAN card is enabled.
1251 Note: this interface will be probably be superseeded by the
1252 generic rfkill class, so it is NOT to be considered stable yet.
1254 Multiple Commands, Module Parameters
1255 ------------------------------------
1257 Multiple commands can be written to the proc files in one shot by
1258 separating them with commas, for example:
1260 echo enable,0xffff > /proc/acpi/ibm/hotkey
1261 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1263 Commands can also be specified when loading the thinkpad-acpi module,
1266 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1268 Enabling debugging output
1269 -------------------------
1271 The module takes a debug parameter which can be used to selectively
1272 enable various classes of debugging output, for example:
1274 modprobe ibm_acpi debug=0xffff
1276 will enable all debugging output classes. It takes a bitmask, so
1277 to enable more than one output class, just add their values.
1279 Debug bitmask Description
1280 0x0001 Initialization and probing
1283 There is also a kernel build option to enable more debugging
1284 information, which may be necessary to debug driver problems.
1286 The level of debugging information output by the driver can be changed
1287 at runtime through sysfs, using the driver attribute debug_level. The
1288 attribute takes the same bitmask as the debug module parameter above.
1290 Force loading of module
1291 -----------------------
1293 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1294 the module parameter force_load=1. Regardless of whether this works or
1295 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1298 Sysfs interface changelog:
1300 0x000100: Initial sysfs support, as a single platform driver and
1302 0x000200: Hot key support for 32 hot keys, and radio slider switch
1304 0x010000: Hot keys are now handled by default over the input
1305 layer, the radio switch generates input event EV_RADIO,
1306 and the driver enables hot key handling by default in
1309 0x020000: ABI fix: added a separate hwmon platform device and
1310 driver, which must be located by name (thinkpad)
1311 and the hwmon class for libsensors4 (lm-sensors 3)
1312 compatibility. Moved all hwmon attributes to this
1313 new platform device.
1315 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1316 support. If you must, use it to know you should not
1317 start an userspace NVRAM poller (allows to detect when
1318 NVRAM is compiled out by the user because it is
1319 unneeded/undesired in the first place).
1320 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1321 and proper hotkey_mask semanthics (version 8 of the
1322 NVRAM polling patch). Some development snapshots of
1323 0.18 had an earlier version that did strange things