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. It was moved to drivers/platform/x86 for
20 kernel 2.6.29 and release 0.22.
22 The driver is named "thinkpad-acpi". In some places, like module
23 names and log messages, "thinkpad_acpi" is used because of userspace
26 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
27 long due to length limitations on some Linux kernel versions.
32 The features currently supported are the following (see below for
33 detailed description):
36 - Bluetooth enable and disable
37 - video output switching, expansion control
38 - ThinkLight on and off
43 - Experimental: embedded controller register dump
44 - LCD brightness control
46 - Fan control and monitoring: fan speed, fan enable/disable
47 - WAN enable and disable
48 - UWB enable and disable
50 A compatibility table by model and feature is maintained on the web
51 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
52 reports, especially if they add to or correct the compatibility table.
53 Please include the following information in your report:
56 - a copy of your ACPI tables, using the "acpidump" utility
57 - a copy of the output of dmidecode, with serial numbers
59 - which driver features work and which don't
60 - the observed behavior of non-working features
62 Any other comments or patches are also more than welcome.
68 If you are compiling this driver as included in the Linux kernel
69 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
70 It is located on the menu path: "Device Drivers" -> "X86 Platform
71 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
77 The driver exports two different interfaces to userspace, which can be
78 used to access the features it provides. One is a legacy procfs-based
79 interface, which will be removed at some time in the future. The other
80 is a new sysfs-based interface which is not complete yet.
82 The procfs interface creates the /proc/acpi/ibm directory. There is a
83 file under that directory for each feature it supports. The procfs
84 interface is mostly frozen, and will change very little if at all: it
85 will not be extended to add any new functionality in the driver, instead
86 all new functionality will be implemented on the sysfs interface.
88 The sysfs interface tries to blend in the generic Linux sysfs subsystems
89 and classes as much as possible. Since some of these subsystems are not
90 yet ready or stabilized, it is expected that this interface will change,
91 and any and all userspace programs must deal with it.
94 Notes about the sysfs interface:
96 Unlike what was done with the procfs interface, correctness when talking
97 to the sysfs interfaces will be enforced, as will correctness in the
98 thinkpad-acpi's implementation of sysfs interfaces.
100 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
101 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
102 maximum correctness, even if that means changing an interface in
103 non-compatible ways. As these interfaces mature both in the kernel and
104 in thinkpad-acpi, such changes should become quite rare.
106 Applications interfacing to the thinkpad-acpi sysfs interfaces must
107 follow all sysfs guidelines and correctly process all errors (the sysfs
108 interface makes extensive use of errors). File descriptors and open /
109 close operations to the sysfs inodes must also be properly implemented.
111 The version of thinkpad-acpi's sysfs interface is exported by the driver
112 as a driver attribute (see below).
114 Sysfs driver attributes are on the driver's sysfs attribute space,
115 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
116 /sys/bus/platform/drivers/thinkpad_hwmon/
118 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
119 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
121 Sysfs device attributes for the sensors and fan are on the
122 thinkpad_hwmon device's sysfs attribute space, but you should locate it
123 looking for a hwmon device with the name attribute of "thinkpad", or
124 better yet, through libsensors.
130 procfs: /proc/acpi/ibm/driver
131 sysfs driver attribute: version
133 The driver name and version. No commands can be written to this file.
136 Sysfs interface version
137 -----------------------
139 sysfs driver attribute: interface_version
141 Version of the thinkpad-acpi sysfs interface, as an unsigned long
142 (output in hex format: 0xAAAABBCC), where:
143 AAAA - major revision
147 The sysfs interface version changelog for the driver can be found at the
148 end of this document. Changes to the sysfs interface done by the kernel
149 subsystems are not documented here, nor are they tracked by this
152 Changes to the thinkpad-acpi sysfs interface are only considered
153 non-experimental when they are submitted to Linux mainline, at which
154 point the changes in this interface are documented and interface_version
155 may be updated. If you are using any thinkpad-acpi features not yet
156 sent to mainline for merging, you do so on your own risk: these features
157 may disappear, or be implemented in a different and incompatible way by
158 the time they are merged in Linux mainline.
160 Changes that are backwards-compatible by nature (e.g. the addition of
161 attributes that do not change the way the other attributes work) do not
162 always warrant an update of interface_version. Therefore, one must
163 expect that an attribute might not be there, and deal with it properly
164 (an attribute not being there *is* a valid way to make it clear that a
165 feature is not available in sysfs).
171 procfs: /proc/acpi/ibm/hotkey
172 sysfs device attribute: hotkey_*
174 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
175 some important events and also keyboard hot key presses to the operating
176 system. Enabling the hotkey functionality of thinkpad-acpi signals the
177 firmware that such a driver is present, and modifies how the ThinkPad
178 firmware will behave in many situations.
180 The driver enables the HKEY ("hot key") event reporting automatically
181 when loaded, and disables it when it is removed.
183 The driver will report HKEY events in the following format:
185 ibm/hotkey HKEY 00000080 0000xxxx
187 Some of these events refer to hot key presses, but not all of them.
189 The driver will generate events over the input layer for hot keys and
190 radio switches, and over the ACPI netlink layer for other events. The
191 input layer support accepts the standard IOCTLs to remap the keycodes
192 assigned to each hot key.
194 The hot key bit mask allows some control over which hot keys generate
195 events. If a key is "masked" (bit set to 0 in the mask), the firmware
196 will handle it. If it is "unmasked", it signals the firmware that
197 thinkpad-acpi would prefer to handle it, if the firmware would be so
198 kind to allow it (and it often doesn't!).
200 Not all bits in the mask can be modified. Not all bits that can be
201 modified do anything. Not all hot keys can be individually controlled
202 by the mask. Some models do not support the mask at all. The behaviour
203 of the mask is, therefore, highly dependent on the ThinkPad model.
205 The driver will filter out any unmasked hotkeys, so even if the firmware
206 doesn't allow disabling an specific hotkey, the driver will not report
207 events for unmasked hotkeys.
209 Note that unmasking some keys prevents their default behavior. For
210 example, if Fn+F5 is unmasked, that key will no longer enable/disable
211 Bluetooth by itself in firmware.
213 Note also that not all Fn key combinations are supported through ACPI
214 depending on the ThinkPad model and firmware version. On those
215 ThinkPads, it is still possible to support some extra hotkeys by
216 polling the "CMOS NVRAM" at least 10 times per second. The driver
217 attempts to enables this functionality automatically when required.
221 The following commands can be written to the /proc/acpi/ibm/hotkey file:
223 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
224 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
225 ... any other 8-hex-digit mask ...
226 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
228 The following commands have been deprecated and will cause the kernel
231 echo enable > /proc/acpi/ibm/hotkey -- does nothing
232 echo disable > /proc/acpi/ibm/hotkey -- returns an error
234 The procfs interface does not support NVRAM polling control. So as to
235 maintain maximum bug-to-bug compatibility, it does not report any masks,
236 nor does it allow one to manipulate the hot key mask when the firmware
237 does not support masks at all, even if NVRAM polling is in use.
242 DEPRECATED, WILL BE REMOVED SOON.
247 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
249 Returns the hot keys mask when thinkpad-acpi was loaded.
250 Upon module unload, the hot keys mask will be restored
251 to this value. This is always 0x80c, because those are
252 the hotkeys that were supported by ancient firmware
253 without mask support.
256 DEPRECATED, WILL BE REMOVED SOON.
262 bit mask to enable reporting (and depending on
263 the firmware, ACPI event generation) for each hot key
264 (see above). Returns the current status of the hot keys
265 mask, and allows one to modify it.
268 bit mask that should enable event reporting for all
269 supported hot keys, when echoed to hotkey_mask above.
270 Unless you know which events need to be handled
271 passively (because the firmware *will* handle them
272 anyway), do *not* use hotkey_all_mask. Use
273 hotkey_recommended_mask, instead. You have been warned.
275 hotkey_recommended_mask:
276 bit mask that should enable event reporting for all
277 supported hot keys, except those which are always
278 handled by the firmware anyway. Echo it to
279 hotkey_mask above, to use. This is the default mask
283 bit mask that selects which hot keys will the driver
284 poll the NVRAM for. This is auto-detected by the driver
285 based on the capabilities reported by the ACPI firmware,
286 but it can be overridden at runtime.
288 Hot keys whose bits are set in hotkey_source_mask are
289 polled for in NVRAM, and reported as hotkey events if
290 enabled in hotkey_mask. Only a few hot keys are
291 available through CMOS NVRAM polling.
293 Warning: when in NVRAM mode, the volume up/down/mute
294 keys are synthesized according to changes in the mixer,
295 which uses a single volume up or volume down hotkey
296 press to unmute, as per the ThinkPad volume mixer user
297 interface. When in ACPI event mode, volume up/down/mute
298 events are reported by the firmware and can behave
299 differently (and that behaviour changes with firmware
300 version -- not just with firmware models -- as well as
304 frequency in Hz for hot key polling. It must be between
305 0 and 25 Hz. Polling is only carried out when strictly
308 Setting hotkey_poll_freq to zero disables polling, and
309 will cause hot key presses that require NVRAM polling
310 to never be reported.
312 Setting hotkey_poll_freq too low may cause repeated
313 pressings of the same hot key to be misreported as a
314 single key press, or to not even be detected at all.
315 The recommended polling frequency is 10Hz.
318 If the ThinkPad has a hardware radio switch, this
319 attribute will read 0 if the switch is in the "radios
320 disabled" position, and 1 if the switch is in the
321 "radios enabled" position.
323 This attribute has poll()/select() support.
326 If the ThinkPad has tablet capabilities, this attribute
327 will read 0 if the ThinkPad is in normal mode, and
328 1 if the ThinkPad is in tablet mode.
330 This attribute has poll()/select() support.
333 Set to 1 if the system is waking up because the user
334 requested a bay ejection. Set to 2 if the system is
335 waking up because the user requested the system to
336 undock. Set to zero for normal wake-ups or wake-ups
337 due to unknown reasons.
339 This attribute has poll()/select() support.
341 wakeup_hotunplug_complete:
342 Set to 1 if the system was waken up because of an
343 undock or bay ejection request, and that request
344 was successfully completed. At this point, it might
345 be useful to send the system back to sleep, at the
346 user's choice. Refer to HKEY events 0x4003 and
349 This attribute has poll()/select() support.
353 A Hot key is mapped to a single input layer EV_KEY event, possibly
354 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
355 code. An EV_SYN event will always be generated to mark the end of the
358 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
359 used as a helper to remap keys, only. They are particularly useful when
360 remapping KEY_UNKNOWN keys.
362 The events are available in an input device, with the following id:
365 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
366 0x17aa (PCI_VENDOR_ID_LENOVO)
367 product: 0x5054 ("TP")
370 The version will have its LSB incremented if the keymap changes in a
371 backwards-compatible way. The MSB shall always be 0x41 for this input
372 device. If the MSB is not 0x41, do not use the device as described in
373 this section, as it is either something else (e.g. another input device
374 exported by a thinkpad driver, such as HDAPS) or its functionality has
375 been changed in a non-backwards compatible way.
377 Adding other event types for other functionalities shall be considered a
378 backwards-compatible change for this input device.
380 Thinkpad-acpi Hot Key event map (version 0x4101):
387 0x1002 0x01 FN+F2 IBM: battery (rare)
390 0x1003 0x02 FN+F3 Many IBM models always report
391 this hot key, even with hot keys
392 disabled or with Fn+F3 masked
394 IBM: screen lock, often turns
395 off the ThinkLight as side-effect
398 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
399 semantics, i.e. sleep-to-RAM).
400 It always generates some kind
401 of event, either the hot key
402 event or an ACPI sleep button
403 event. The firmware may
404 refuse to generate further FN+F4
405 key presses until a S3 or S4 ACPI
406 sleep cycle is performed or some
409 0x1005 0x04 FN+F5 Radio. Enables/disables
410 the internal Bluetooth hardware
411 and W-WAN card if left in control
412 of the firmware. Does not affect
414 Should be used to turn on/off all
415 radios (Bluetooth+W-WAN+WLAN),
420 0x1007 0x06 FN+F7 Video output cycle.
421 Do you feel lucky today?
423 0x1008 0x07 FN+F8 IBM: toggle screen expand
424 Lenovo: configure UltraNav,
425 or toggle screen expand
431 0x100C 0x0B FN+F12 Sleep to disk. You are always
432 supposed to handle it yourself,
433 either through the ACPI event,
434 or through a hotkey event.
435 The firmware may refuse to
436 generate further FN+F12 key
437 press events until a S3 or S4
438 ACPI sleep cycle is performed,
441 0x100D 0x0C FN+BACKSPACE -
442 0x100E 0x0D FN+INSERT -
443 0x100F 0x0E FN+DELETE -
445 0x1010 0x0F FN+HOME Brightness up. This key is
446 always handled by the firmware
447 in IBM ThinkPads, even when
448 unmasked. Just leave it alone.
449 For Lenovo ThinkPads with a new
450 BIOS, it has to be handled either
451 by the ACPI OSI, or by userspace.
452 The driver does the right thing,
453 never mess with this.
454 0x1011 0x10 FN+END Brightness down. See brightness
457 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
458 always handled by the firmware,
461 0x1013 0x12 FN+PGDOWN -
463 0x1014 0x13 FN+SPACE Zoom key
465 0x1015 0x14 VOLUME UP Internal mixer volume up. This
466 key is always handled by the
467 firmware, even when unmasked.
468 NOTE: Lenovo seems to be changing
470 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
471 key is always handled by the
472 firmware, even when unmasked.
473 NOTE: Lenovo seems to be changing
475 0x1017 0x16 MUTE Mute internal mixer. This
476 key is always handled by the
477 firmware, even when unmasked.
479 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
485 The ThinkPad firmware does not allow one to differentiate when most hot
486 keys are pressed or released (either that, or we don't know how to, yet).
487 For these keys, the driver generates a set of events for a key press and
488 immediately issues the same set of events for a key release. It is
489 unknown by the driver if the ThinkPad firmware triggered these events on
490 hot key press or release, but the firmware will do it for either one, not
493 If a key is mapped to KEY_RESERVED, it generates no input events at all.
494 If a key is mapped to KEY_UNKNOWN, it generates an input event that
495 includes an scan code. If a key is mapped to anything else, it will
496 generate input device EV_KEY events.
498 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
501 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
502 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
504 Non hotkey ACPI HKEY event map:
505 -------------------------------
507 Events that are never propagated by the driver:
509 0x2304 System is waking up from suspend to undock
510 0x2305 System is waking up from suspend to eject bay
511 0x2404 System is waking up from hibernation to undock
512 0x2405 System is waking up from hibernation to eject bay
515 0x5009 Tablet swivel: switched to tablet mode
516 0x500A Tablet swivel: switched to normal mode
517 0x5010 Brightness level changed/control event
518 0x6000 KEYBOARD: Numlock key pressed
519 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
520 0x7000 Radio Switch may have changed state
523 Events that are propagated by the driver to userspace:
525 0x2313 ALARM: System is waking up from suspend because
526 the battery is nearly empty
527 0x2413 ALARM: System is waking up from hibernation because
528 the battery is nearly empty
529 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
530 0x3006 Bay hotplug request (hint to power up SATA link when
531 the optical drive tray is ejected)
532 0x4003 Undocked (see 0x2x04), can sleep again
533 0x4010 Docked into hotplug port replicator (non-ACPI dock)
534 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
535 0x500B Tablet pen inserted into its storage bay
536 0x500C Tablet pen removed from its storage bay
537 0x6011 ALARM: battery is too hot
538 0x6012 ALARM: battery is extremely hot
539 0x6021 ALARM: a sensor is too hot
540 0x6022 ALARM: a sensor is extremely hot
541 0x6030 System thermal table changed
542 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
543 0x60C0 X1 Yoga 2016, Tablet mode status changed
545 Battery nearly empty alarms are a last resort attempt to get the
546 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
547 cleanly (0x2413) before power is lost. They must be acted upon, as the
548 wake up caused by the firmware will have negated most safety nets...
550 When any of the "too hot" alarms happen, according to Lenovo the user
551 should suspend or hibernate the laptop (and in the case of battery
552 alarms, unplug the AC adapter) to let it cool down. These alarms do
553 signal that something is wrong, they should never happen on normal
554 operating conditions.
556 The "extremely hot" alarms are emergencies. According to Lenovo, the
557 operating system is to force either an immediate suspend or hibernate
558 cycle, or a system shutdown. Obviously, something is very wrong if this
562 Brightness hotkey notes:
564 Don't mess with the brightness hotkeys in a Thinkpad. If you want
565 notifications for OSD, use the sysfs backlight class event support.
567 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
568 automatically for the cases were userspace has to do something to
569 implement brightness changes. When you override these events, you will
570 either fail to handle properly the ThinkPads that require explicit
571 action to change backlight brightness, or the ThinkPads that require
572 that no action be taken to work properly.
578 procfs: /proc/acpi/ibm/bluetooth
579 sysfs device attribute: bluetooth_enable (deprecated)
580 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
582 This feature shows the presence and current state of a ThinkPad
583 Bluetooth device in the internal ThinkPad CDC slot.
585 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
586 so it is kept across reboots and power-off.
590 If Bluetooth is installed, the following commands can be used:
592 echo enable > /proc/acpi/ibm/bluetooth
593 echo disable > /proc/acpi/ibm/bluetooth
597 If the Bluetooth CDC card is installed, it can be enabled /
598 disabled through the "bluetooth_enable" thinkpad-acpi device
599 attribute, and its current status can also be queried.
602 0: disables Bluetooth / Bluetooth is disabled
603 1: enables Bluetooth / Bluetooth is enabled.
605 Note: this interface has been superseded by the generic rfkill
606 class. It has been deprecated, and it will be removed in year
609 rfkill controller switch "tpacpi_bluetooth_sw": refer to
610 Documentation/rfkill.txt for details.
613 Video output control -- /proc/acpi/ibm/video
614 --------------------------------------------
616 This feature allows control over the devices used for video output -
617 LCD, CRT or DVI (if available). The following commands are available:
619 echo lcd_enable > /proc/acpi/ibm/video
620 echo lcd_disable > /proc/acpi/ibm/video
621 echo crt_enable > /proc/acpi/ibm/video
622 echo crt_disable > /proc/acpi/ibm/video
623 echo dvi_enable > /proc/acpi/ibm/video
624 echo dvi_disable > /proc/acpi/ibm/video
625 echo auto_enable > /proc/acpi/ibm/video
626 echo auto_disable > /proc/acpi/ibm/video
627 echo expand_toggle > /proc/acpi/ibm/video
628 echo video_switch > /proc/acpi/ibm/video
630 NOTE: Access to this feature is restricted to processes owning the
631 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
632 enough with some versions of X.org to crash it.
634 Each video output device can be enabled or disabled individually.
635 Reading /proc/acpi/ibm/video shows the status of each device.
637 Automatic video switching can be enabled or disabled. When automatic
638 video switching is enabled, certain events (e.g. opening the lid,
639 docking or undocking) cause the video output device to change
640 automatically. While this can be useful, it also causes flickering
641 and, on the X40, video corruption. By disabling automatic switching,
642 the flickering or video corruption can be avoided.
644 The video_switch command cycles through the available video outputs
645 (it simulates the behavior of Fn-F7).
647 Video expansion can be toggled through this feature. This controls
648 whether the display is expanded to fill the entire LCD screen when a
649 mode with less than full resolution is used. Note that the current
650 video expansion status cannot be determined through this feature.
652 Note that on many models (particularly those using Radeon graphics
653 chips) the X driver configures the video card in a way which prevents
654 Fn-F7 from working. This also disables the video output switching
655 features of this driver, as it uses the same ACPI methods as
656 Fn-F7. Video switching on the console should still work.
658 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
664 procfs: /proc/acpi/ibm/light
665 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
669 The ThinkLight status can be read and set through the procfs interface. A
670 few models which do not make the status available will show the ThinkLight
671 status as "unknown". The available commands are:
673 echo on > /proc/acpi/ibm/light
674 echo off > /proc/acpi/ibm/light
678 The ThinkLight sysfs interface is documented by the LED class
679 documentation, in Documentation/leds/leds-class.txt. The ThinkLight LED name
680 is "tpacpi::thinklight".
682 Due to limitations in the sysfs LED class, if the status of the ThinkLight
683 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
684 It is impossible to know if the status returned through sysfs is valid.
690 procfs: /proc/acpi/ibm/cmos
691 sysfs device attribute: cmos_command
693 This feature is mostly used internally by the ACPI firmware to keep the legacy
694 CMOS NVRAM bits in sync with the current machine state, and to record this
695 state so that the ThinkPad will retain such settings across reboots.
697 Some of these commands actually perform actions in some ThinkPad models, but
698 this is expected to disappear more and more in newer models. As an example, in
699 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
700 real, but commands 0 to 2 don't control the mixer anymore (they have been
701 phased out) and just update the NVRAM.
703 The range of valid cmos command numbers is 0 to 21, but not all have an
704 effect and the behavior varies from model to model. Here is the behavior
705 on the X40 (tpb is the ThinkPad Buttons utility):
707 0 - Related to "Volume down" key press
708 1 - Related to "Volume up" key press
709 2 - Related to "Mute on" key press
710 3 - Related to "Access IBM" key press
711 4 - Related to "LCD brightness up" key press
712 5 - Related to "LCD brightness down" key press
713 11 - Related to "toggle screen expansion" key press/function
714 12 - Related to "ThinkLight on"
715 13 - Related to "ThinkLight off"
716 14 - Related to "ThinkLight" key press (toggle ThinkLight)
718 The cmos command interface is prone to firmware split-brain problems, as
719 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
720 exported just as a debug tool.
726 procfs: /proc/acpi/ibm/led
727 sysfs attributes: as per LED class, see below for names
729 Some of the LED indicators can be controlled through this feature. On
730 some older ThinkPad models, it is possible to query the status of the
731 LED indicators as well. Newer ThinkPads cannot query the real status
732 of the LED indicators.
734 Because misuse of the LEDs could induce an unaware user to perform
735 dangerous actions (like undocking or ejecting a bay device while the
736 buses are still active), or mask an important alarm (such as a nearly
737 empty battery, or a broken battery), access to most LEDs is
740 Unrestricted access to all LEDs requires that thinkpad-acpi be
741 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
742 Distributions must never enable this option. Individual users that
743 are aware of the consequences are welcome to enabling it.
745 Audio mute and microphone mute LEDs are supported, but currently not
746 visible to userspace. They are used by the snd-hda-intel audio driver.
750 The available commands are:
752 echo '<LED number> on' >/proc/acpi/ibm/led
753 echo '<LED number> off' >/proc/acpi/ibm/led
754 echo '<LED number> blink' >/proc/acpi/ibm/led
756 The <LED number> range is 0 to 15. The set of LEDs that can be
757 controlled varies from model to model. Here is the common ThinkPad
765 5 - UltraBase battery slot
772 13, 14, 15 - (unknown)
774 All of the above can be turned on and off and can be made to blink.
778 The ThinkPad LED sysfs interface is described in detail by the LED class
779 documentation, in Documentation/leds/leds-class.txt.
781 The LEDs are named (in LED ID order, from 0 to 12):
782 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
783 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
784 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
785 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
786 "tpacpi::thinkvantage".
788 Due to limitations in the sysfs LED class, if the status of the LED
789 indicators cannot be read due to an error, thinkpad-acpi will report it as
790 a brightness of zero (same as LED off).
792 If the thinkpad firmware doesn't support reading the current status,
793 trying to read the current LED brightness will just return whatever
794 brightness was last written to that attribute.
796 These LEDs can blink using hardware acceleration. To request that a
797 ThinkPad indicator LED should blink in hardware accelerated mode, use the
798 "timer" trigger, and leave the delay_on and delay_off parameters set to
799 zero (to request hardware acceleration autodetection).
801 LEDs that are known not to exist in a given ThinkPad model are not
802 made available through the sysfs interface. If you have a dock and you
803 notice there are LEDs listed for your ThinkPad that do not exist (and
804 are not in the dock), or if you notice that there are missing LEDs,
805 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
808 ACPI sounds -- /proc/acpi/ibm/beep
809 ----------------------------------
811 The BEEP method is used internally by the ACPI firmware to provide
812 audible alerts in various situations. This feature allows the same
813 sounds to be triggered manually.
815 The commands are non-negative integer numbers:
817 echo <number> >/proc/acpi/ibm/beep
819 The valid <number> range is 0 to 17. Not all numbers trigger sounds
820 and the sounds vary from model to model. Here is the behavior on the
823 0 - stop a sound in progress (but use 17 to stop 16)
824 2 - two beeps, pause, third beep ("low battery")
826 4 - high, followed by low-pitched beep ("unable")
828 6 - very high, followed by high-pitched beep ("AC/DC")
829 7 - high-pitched beep
830 9 - three short beeps
832 12 - low-pitched beep
833 15 - three high-pitched beeps repeating constantly, stop with 0
834 16 - one medium-pitched beep repeating constantly, stop with 17
841 procfs: /proc/acpi/ibm/thermal
842 sysfs device attributes: (hwmon "thinkpad") temp*_input
844 Most ThinkPads include six or more separate temperature sensors but only
845 expose the CPU temperature through the standard ACPI methods. This
846 feature shows readings from up to eight different sensors on older
847 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
849 For example, on the X40, a typical output may be:
850 temperatures: 42 42 45 41 36 -128 33 -128
852 On the T43/p, a typical output may be:
853 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
855 The mapping of thermal sensors to physical locations varies depending on
856 system-board model (and thus, on ThinkPad model).
858 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
859 tries to track down these locations for various models.
861 Most (newer?) models seem to follow this pattern:
864 2: (depends on model)
865 3: (depends on model)
867 5: Main battery: main sensor
868 6: Bay battery: main sensor
869 7: Main battery: secondary sensor
870 8: Bay battery: secondary sensor
871 9-15: (depends on model)
873 For the R51 (source: Thomas Gruber):
877 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
878 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
879 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
881 9: MCH (northbridge) to DRAM Bus
882 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
884 11: Power regulator, underside of system board, below F2 key
886 The A31 has a very atypical layout for the thermal sensors
887 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
889 2: Main Battery: main sensor
891 4: Bay Battery: main sensor
894 7: Main Battery: secondary sensor
895 8: Bay Battery: secondary sensor
899 Readings from sensors that are not available return -128.
900 No commands can be written to this file.
903 Sensors that are not available return the ENXIO error. This
904 status may change at runtime, as there are hotplug thermal
905 sensors, like those inside the batteries and docks.
907 thinkpad-acpi thermal sensors are reported through the hwmon
908 subsystem, and follow all of the hwmon guidelines at
911 EXPERIMENTAL: Embedded controller register dump
912 -----------------------------------------------
914 This feature is not included in the thinkpad driver anymore.
915 Instead the EC can be accessed through /sys/kernel/debug/ec with
916 a userspace tool which can be found here:
917 ftp://ftp.suse.com/pub/people/trenn/sources/ec
919 Use it to determine the register holding the fan
920 speed on some models. To do that, do the following:
921 - make sure the battery is fully charged
922 - make sure the fan is running
923 - use above mentioned tool to read out the EC
925 Often fan and temperature values vary between
926 readings. Since temperatures don't change vary fast, you can take
927 several quick dumps to eliminate them.
929 You can use a similar method to figure out the meaning of other
930 embedded controller registers - e.g. make sure nothing else changes
931 except the charging or discharging battery to determine which
932 registers contain the current battery capacity, etc. If you experiment
933 with this, do send me your results (including some complete dumps with
934 a description of the conditions when they were taken.)
937 LCD brightness control
938 ----------------------
940 procfs: /proc/acpi/ibm/brightness
941 sysfs backlight device "thinkpad_screen"
943 This feature allows software control of the LCD brightness on ThinkPad
944 models which don't have a hardware brightness slider.
946 It has some limitations: the LCD backlight cannot be actually turned
947 on or off by this interface, it just controls the backlight brightness
950 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
951 has eight brightness levels, ranging from 0 to 7. Some of the levels
952 may not be distinct. Later Lenovo models that implement the ACPI
953 display backlight brightness control methods have 16 levels, ranging
956 For IBM ThinkPads, there are two interfaces to the firmware for direct
957 brightness control, EC and UCMS (or CMOS). To select which one should be
958 used, use the brightness_mode module parameter: brightness_mode=1 selects
959 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
960 mode with NVRAM backing (so that brightness changes are remembered across
963 The driver tries to select which interface to use from a table of
964 defaults for each ThinkPad model. If it makes a wrong choice, please
965 report this as a bug, so that we can fix it.
967 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
969 When display backlight brightness controls are available through the
970 standard ACPI interface, it is best to use it instead of this direct
971 ThinkPad-specific interface. The driver will disable its native
972 backlight brightness control interface if it detects that the standard
973 ACPI interface is available in the ThinkPad.
975 If you want to use the thinkpad-acpi backlight brightness control
976 instead of the generic ACPI video backlight brightness control for some
977 reason, you should use the acpi_backlight=vendor kernel parameter.
979 The brightness_enable module parameter can be used to control whether
980 the LCD brightness control feature will be enabled when available.
981 brightness_enable=0 forces it to be disabled. brightness_enable=1
982 forces it to be enabled when available, even if the standard ACPI
983 interface is also available.
987 The available commands are:
989 echo up >/proc/acpi/ibm/brightness
990 echo down >/proc/acpi/ibm/brightness
991 echo 'level <level>' >/proc/acpi/ibm/brightness
995 The interface is implemented through the backlight sysfs class, which is
996 poorly documented at this time.
998 Locate the thinkpad_screen device under /sys/class/backlight, and inside
999 it there will be the following attributes:
1002 Reads the maximum brightness the hardware can be set to.
1003 The minimum is always zero.
1006 Reads what brightness the screen is set to at this instant.
1009 Writes request the driver to change brightness to the
1010 given value. Reads will tell you what brightness the
1011 driver is trying to set the display to when "power" is set
1012 to zero and the display has not been dimmed by a kernel
1013 power management event.
1016 power management mode, where 0 is "display on", and 1 to 3
1017 will dim the display backlight to brightness level 0
1018 because thinkpad-acpi cannot really turn the backlight
1019 off. Kernel power management events can temporarily
1020 increase the current power management level, i.e. they can
1026 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1027 interface and the ACPI-based backlight level change interface
1028 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1029 at the same time. The two will interact in bad ways, do funny things,
1030 and maybe reduce the life of the backlight lamps by needlessly kicking
1031 its level up and down at every change.
1034 Volume control (Console Audio control)
1035 --------------------------------------
1037 procfs: /proc/acpi/ibm/volume
1038 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1040 NOTE: by default, the volume control interface operates in read-only
1041 mode, as it is supposed to be used for on-screen-display purposes.
1042 The read/write mode can be enabled through the use of the
1043 "volume_control=1" module parameter.
1045 NOTE: distros are urged to not enable volume_control by default, this
1046 should be done by the local admin only. The ThinkPad UI is for the
1047 console audio control to be done through the volume keys only, and for
1048 the desktop environment to just provide on-screen-display feedback.
1049 Software volume control should be done only in the main AC97/HDA
1053 About the ThinkPad Console Audio control:
1055 ThinkPads have a built-in amplifier and muting circuit that drives the
1056 console headphone and speakers. This circuit is after the main AC97
1057 or HDA mixer in the audio path, and under exclusive control of the
1060 ThinkPads have three special hotkeys to interact with the console
1061 audio control: volume up, volume down and mute.
1063 It is worth noting that the normal way the mute function works (on
1064 ThinkPads that do not have a "mute LED") is:
1066 1. Press mute to mute. It will *always* mute, you can press it as
1067 many times as you want, and the sound will remain mute.
1069 2. Press either volume key to unmute the ThinkPad (it will _not_
1070 change the volume, it will just unmute).
1072 This is a very superior design when compared to the cheap software-only
1073 mute-toggle solution found on normal consumer laptops: you can be
1074 absolutely sure the ThinkPad will not make noise if you press the mute
1075 button, no matter the previous state.
1077 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1078 amplifiers driving the speakers and headphone output, and the firmware
1079 also handles volume control for the headphone and speakers on these
1080 ThinkPads without any help from the operating system (this volume
1081 control stage exists after the main AC97 or HDA mixer in the audio
1084 The newer Lenovo models only have firmware mute control, and depend on
1085 the main HDA mixer to do volume control (which is done by the operating
1086 system). In this case, the volume keys are filtered out for unmute
1087 key press (there are some firmware bugs in this area) and delivered as
1088 normal key presses to the operating system (thinkpad-acpi is not
1092 The ThinkPad-ACPI volume control:
1094 The preferred way to interact with the Console Audio control is the
1097 The legacy procfs interface allows one to read the current state,
1098 and if volume control is enabled, accepts the following commands:
1100 echo up >/proc/acpi/ibm/volume
1101 echo down >/proc/acpi/ibm/volume
1102 echo mute >/proc/acpi/ibm/volume
1103 echo unmute >/proc/acpi/ibm/volume
1104 echo 'level <level>' >/proc/acpi/ibm/volume
1106 The <level> number range is 0 to 14 although not all of them may be
1107 distinct. To unmute the volume after the mute command, use either the
1108 up or down command (the level command will not unmute the volume), or
1111 You can use the volume_capabilities parameter to tell the driver
1112 whether your thinkpad has volume control or mute-only control:
1113 volume_capabilities=1 for mixers with mute and volume control,
1114 volume_capabilities=2 for mixers with only mute control.
1116 If the driver misdetects the capabilities for your ThinkPad model,
1117 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1118 can update the driver.
1120 There are two strategies for volume control. To select which one
1121 should be used, use the volume_mode module parameter: volume_mode=1
1122 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1123 (so that volume/mute changes are remembered across shutdown/reboot).
1125 The driver will operate in volume_mode=3 by default. If that does not
1126 work well on your ThinkPad model, please report this to
1127 ibm-acpi-devel@lists.sourceforge.net.
1129 The driver supports the standard ALSA module parameters. If the ALSA
1130 mixer is disabled, the driver will disable all volume functionality.
1133 Fan control and monitoring: fan speed, fan enable/disable
1134 ---------------------------------------------------------
1136 procfs: /proc/acpi/ibm/fan
1137 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1138 pwm1_enable, fan2_input
1139 sysfs hwmon driver attributes: fan_watchdog
1141 NOTE NOTE NOTE: fan control operations are disabled by default for
1142 safety reasons. To enable them, the module parameter "fan_control=1"
1143 must be given to thinkpad-acpi.
1145 This feature attempts to show the current fan speed, control mode and
1146 other fan data that might be available. The speed is read directly
1147 from the hardware registers of the embedded controller. This is known
1148 to work on later R, T, X and Z series ThinkPads but may show a bogus
1149 value on other models.
1151 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1152 controlled separately, it shares the main fan control.
1156 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1157 stops the fan. The higher the level, the higher the fan speed, although
1158 adjacent levels often map to the same fan speed. 7 is the highest
1159 level, where the fan reaches the maximum recommended speed.
1161 Level "auto" means the EC changes the fan level according to some
1162 internal algorithm, usually based on readings from the thermal sensors.
1164 There is also a "full-speed" level, also known as "disengaged" level.
1165 In this level, the EC disables the speed-locked closed-loop fan control,
1166 and drives the fan as fast as it can go, which might exceed hardware
1167 limits, so use this level with caution.
1169 The fan usually ramps up or down slowly from one speed to another, and
1170 it is normal for the EC to take several seconds to react to fan
1171 commands. The full-speed level may take up to two minutes to ramp up to
1172 maximum speed, and in some ThinkPads, the tachometer readings go stale
1173 while the EC is transitioning to the full-speed level.
1175 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1176 monitoring all of the temperature sensor readings and you are ready to
1177 enable it if necessary to avoid overheating.
1179 An enabled fan in level "auto" may stop spinning if the EC decides the
1180 ThinkPad is cool enough and doesn't need the extra airflow. This is
1181 normal, and the EC will spin the fan up if the various thermal readings
1184 On the X40, this seems to depend on the CPU and HDD temperatures.
1185 Specifically, the fan is turned on when either the CPU temperature
1186 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1187 fan is turned off when the CPU temperature drops to 49 degrees and the
1188 HDD temperature drops to 41 degrees. These thresholds cannot
1189 currently be controlled.
1191 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1192 certain conditions are met. It will override any fan programming done
1193 through thinkpad-acpi.
1195 The thinkpad-acpi kernel driver can be programmed to revert the fan
1196 level to a safe setting if userspace does not issue one of the procfs
1197 fan commands: "enable", "disable", "level" or "watchdog", or if there
1198 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1199 set to 1, manual mode) within a configurable amount of time of up to
1200 120 seconds. This functionality is called fan safety watchdog.
1202 Note that the watchdog timer stops after it enables the fan. It will be
1203 rearmed again automatically (using the same interval) when one of the
1204 above mentioned fan commands is received. The fan watchdog is,
1205 therefore, not suitable to protect against fan mode changes made through
1206 means other than the "enable", "disable", and "level" procfs fan
1207 commands, or the hwmon fan control sysfs interface.
1211 The fan may be enabled or disabled with the following commands:
1213 echo enable >/proc/acpi/ibm/fan
1214 echo disable >/proc/acpi/ibm/fan
1216 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1217 will try to place it in a safe level if it is too slow or disabled.
1219 The fan level can be controlled with the command:
1221 echo 'level <level>' > /proc/acpi/ibm/fan
1223 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1224 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1225 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1226 "full-speed", and reports it as "disengaged" for backwards
1229 On the X31 and X40 (and ONLY on those models), the fan speed can be
1230 controlled to a certain degree. Once the fan is running, it can be
1231 forced to run faster or slower with the following command:
1233 echo 'speed <speed>' > /proc/acpi/ibm/fan
1235 The sustainable range of fan speeds on the X40 appears to be from about
1236 3700 to about 7350. Values outside this range either do not have any
1237 effect or the fan speed eventually settles somewhere in that range. The
1238 fan cannot be stopped or started with this command. This functionality
1239 is incomplete, and not available through the sysfs interface.
1241 To program the safety watchdog, use the "watchdog" command.
1243 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1245 If you want to disable the watchdog, use 0 as the interval.
1249 The sysfs interface follows the hwmon subsystem guidelines for the most
1250 part, and the exception is the fan safety watchdog.
1252 Writes to any of the sysfs attributes may return the EINVAL error if
1253 that operation is not supported in a given ThinkPad or if the parameter
1254 is out-of-bounds, and EPERM if it is forbidden. They may also return
1255 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1258 Features not yet implemented by the driver return ENOSYS.
1260 hwmon device attribute pwm1_enable:
1261 0: PWM offline (fan is set to full-speed mode)
1262 1: Manual PWM control (use pwm1 to set fan level)
1263 2: Hardware PWM control (EC "auto" mode)
1264 3: reserved (Software PWM control, not implemented yet)
1266 Modes 0 and 2 are not supported by all ThinkPads, and the
1267 driver is not always able to detect this. If it does know a
1268 mode is unsupported, it will return -EINVAL.
1270 hwmon device attribute pwm1:
1271 Fan level, scaled from the firmware values of 0-7 to the hwmon
1272 scale of 0-255. 0 means fan stopped, 255 means highest normal
1275 This attribute only commands the fan if pmw1_enable is set to 1
1276 (manual PWM control).
1278 hwmon device attribute fan1_input:
1279 Fan tachometer reading, in RPM. May go stale on certain
1280 ThinkPads while the EC transitions the PWM to offline mode,
1281 which can take up to two minutes. May return rubbish on older
1284 hwmon device attribute fan2_input:
1285 Fan tachometer reading, in RPM, for the secondary fan.
1286 Available only on some ThinkPads. If the secondary fan is
1287 not installed, will always read 0.
1289 hwmon driver attribute fan_watchdog:
1290 Fan safety watchdog timer interval, in seconds. Minimum is
1291 1 second, maximum is 120 seconds. 0 disables the watchdog.
1293 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1295 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1296 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1297 would be the safest choice, though).
1303 procfs: /proc/acpi/ibm/wan
1304 sysfs device attribute: wwan_enable (deprecated)
1305 sysfs rfkill class: switch "tpacpi_wwan_sw"
1307 This feature shows the presence and current state of the built-in
1308 Wireless WAN device.
1310 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1311 so it is kept across reboots and power-off.
1313 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1314 ThinkPad models which come with this module installed.
1318 If the W-WAN card is installed, the following commands can be used:
1320 echo enable > /proc/acpi/ibm/wan
1321 echo disable > /proc/acpi/ibm/wan
1325 If the W-WAN card is installed, it can be enabled /
1326 disabled through the "wwan_enable" thinkpad-acpi device
1327 attribute, and its current status can also be queried.
1330 0: disables WWAN card / WWAN card is disabled
1331 1: enables WWAN card / WWAN card is enabled.
1333 Note: this interface has been superseded by the generic rfkill
1334 class. It has been deprecated, and it will be removed in year
1337 rfkill controller switch "tpacpi_wwan_sw": refer to
1338 Documentation/rfkill.txt for details.
1344 This feature is considered EXPERIMENTAL because it has not been extensively
1345 tested and validated in various ThinkPad models yet. The feature may not
1346 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1347 the experimental=1 parameter when loading the module.
1349 sysfs rfkill class: switch "tpacpi_uwb_sw"
1351 This feature exports an rfkill controller for the UWB device, if one is
1352 present and enabled in the BIOS.
1356 rfkill controller switch "tpacpi_uwb_sw": refer to
1357 Documentation/rfkill.txt for details.
1362 sysfs device attribute: adaptive_kbd_mode
1364 This sysfs attribute controls the keyboard "face" that will be shown on the
1365 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1369 2 = Web-browser mode
1370 3 = Web-conference mode
1374 For more details about which buttons will appear depending on the mode, please
1375 review the laptop's user guide:
1376 http://www.lenovo.com/shop/americas/content/user_guides/x1carbon_2_ug_en.pdf
1378 Multiple Commands, Module Parameters
1379 ------------------------------------
1381 Multiple commands can be written to the proc files in one shot by
1382 separating them with commas, for example:
1384 echo enable,0xffff > /proc/acpi/ibm/hotkey
1385 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1387 Commands can also be specified when loading the thinkpad-acpi module,
1390 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1393 Enabling debugging output
1394 -------------------------
1396 The module takes a debug parameter which can be used to selectively
1397 enable various classes of debugging output, for example:
1399 modprobe thinkpad_acpi debug=0xffff
1401 will enable all debugging output classes. It takes a bitmask, so
1402 to enable more than one output class, just add their values.
1404 Debug bitmask Description
1405 0x8000 Disclose PID of userspace programs
1406 accessing some functions of the driver
1407 0x0001 Initialization and probing
1409 0x0004 RF Transmitter control (RFKILL)
1410 (bluetooth, WWAN, UWB...)
1411 0x0008 HKEY event interface, hotkeys
1413 0x0020 Backlight brightness
1414 0x0040 Audio mixer/volume control
1416 There is also a kernel build option to enable more debugging
1417 information, which may be necessary to debug driver problems.
1419 The level of debugging information output by the driver can be changed
1420 at runtime through sysfs, using the driver attribute debug_level. The
1421 attribute takes the same bitmask as the debug module parameter above.
1424 Force loading of module
1425 -----------------------
1427 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1428 the module parameter force_load=1. Regardless of whether this works or
1429 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1432 Sysfs interface changelog:
1434 0x000100: Initial sysfs support, as a single platform driver and
1436 0x000200: Hot key support for 32 hot keys, and radio slider switch
1438 0x010000: Hot keys are now handled by default over the input
1439 layer, the radio switch generates input event EV_RADIO,
1440 and the driver enables hot key handling by default in
1443 0x020000: ABI fix: added a separate hwmon platform device and
1444 driver, which must be located by name (thinkpad)
1445 and the hwmon class for libsensors4 (lm-sensors 3)
1446 compatibility. Moved all hwmon attributes to this
1447 new platform device.
1449 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1450 support. If you must, use it to know you should not
1451 start a userspace NVRAM poller (allows to detect when
1452 NVRAM is compiled out by the user because it is
1453 unneeded/undesired in the first place).
1454 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1455 and proper hotkey_mask semantics (version 8 of the
1456 NVRAM polling patch). Some development snapshots of
1457 0.18 had an earlier version that did strange things
1460 0x020200: Add poll()/select() support to the following attributes:
1461 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1463 0x020300: hotkey enable/disable support removed, attributes
1464 hotkey_bios_enabled and hotkey_enable deprecated and
1467 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1468 to not exist in a given model are not registered with
1469 the LED sysfs class anymore.
1471 0x020500: Updated hotkey driver, hotkey_mask is always available
1472 and it is always able to disable hot keys. Very old
1473 thinkpads are properly supported. hotkey_bios_mask
1474 is deprecated and marked for removal.
1476 0x020600: Marker for backlight change event support.
1478 0x020700: Support for mute-only mixers.
1479 Volume control in read-only mode by default.
1480 Marker for ALSA mixer support.
git.samba.org / sfrench / cifs-2.6.git / blob