1 ===========================
2 ThinkPad ACPI Extras Driver
3 ===========================
9 - Borislav Deianov <borislav@users.sf.net>
10 - Henrique de Moraes Holschuh <hmh@hmh.eng.br>
12 http://ibm-acpi.sf.net/
14 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
15 supports various features of these laptops which are accessible
16 through the ACPI and ACPI EC framework, but not otherwise fully
17 supported by the generic Linux ACPI drivers.
19 This driver used to be named ibm-acpi until kernel 2.6.21 and release
20 0.13-20070314. It used to be in the drivers/acpi tree, but it was
21 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
22 2.6.22, and release 0.14. It was moved to drivers/platform/x86 for
23 kernel 2.6.29 and release 0.22.
25 The driver is named "thinkpad-acpi". In some places, like module
26 names and log messages, "thinkpad_acpi" is used because of userspace
29 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
30 long due to length limitations on some Linux kernel versions.
35 The features currently supported are the following (see below for
36 detailed description):
39 - Bluetooth enable and disable
40 - video output switching, expansion control
41 - ThinkLight on and off
46 - Experimental: embedded controller register dump
47 - LCD brightness control
49 - Fan control and monitoring: fan speed, fan enable/disable
50 - WAN enable and disable
51 - UWB enable and disable
52 - LCD Shadow (PrivacyGuard) enable and disable
54 A compatibility table by model and feature is maintained on the web
55 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
56 reports, especially if they add to or correct the compatibility table.
57 Please include the following information in your report:
60 - a copy of your ACPI tables, using the "acpidump" utility
61 - a copy of the output of dmidecode, with serial numbers
63 - which driver features work and which don't
64 - the observed behavior of non-working features
66 Any other comments or patches are also more than welcome.
72 If you are compiling this driver as included in the Linux kernel
73 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
74 It is located on the menu path: "Device Drivers" -> "X86 Platform
75 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
81 The driver exports two different interfaces to userspace, which can be
82 used to access the features it provides. One is a legacy procfs-based
83 interface, which will be removed at some time in the future. The other
84 is a new sysfs-based interface which is not complete yet.
86 The procfs interface creates the /proc/acpi/ibm directory. There is a
87 file under that directory for each feature it supports. The procfs
88 interface is mostly frozen, and will change very little if at all: it
89 will not be extended to add any new functionality in the driver, instead
90 all new functionality will be implemented on the sysfs interface.
92 The sysfs interface tries to blend in the generic Linux sysfs subsystems
93 and classes as much as possible. Since some of these subsystems are not
94 yet ready or stabilized, it is expected that this interface will change,
95 and any and all userspace programs must deal with it.
98 Notes about the sysfs interface
99 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
101 Unlike what was done with the procfs interface, correctness when talking
102 to the sysfs interfaces will be enforced, as will correctness in the
103 thinkpad-acpi's implementation of sysfs interfaces.
105 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
106 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
107 maximum correctness, even if that means changing an interface in
108 non-compatible ways. As these interfaces mature both in the kernel and
109 in thinkpad-acpi, such changes should become quite rare.
111 Applications interfacing to the thinkpad-acpi sysfs interfaces must
112 follow all sysfs guidelines and correctly process all errors (the sysfs
113 interface makes extensive use of errors). File descriptors and open /
114 close operations to the sysfs inodes must also be properly implemented.
116 The version of thinkpad-acpi's sysfs interface is exported by the driver
117 as a driver attribute (see below).
119 Sysfs driver attributes are on the driver's sysfs attribute space,
120 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
121 /sys/bus/platform/drivers/thinkpad_hwmon/
123 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
124 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
126 Sysfs device attributes for the sensors and fan are on the
127 thinkpad_hwmon device's sysfs attribute space, but you should locate it
128 looking for a hwmon device with the name attribute of "thinkpad", or
129 better yet, through libsensors. For 4.14+ sysfs attributes were moved to the
130 hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or
131 /sys/class/hwmon/hwmon?).
136 procfs: /proc/acpi/ibm/driver
138 sysfs driver attribute: version
140 The driver name and version. No commands can be written to this file.
143 Sysfs interface version
144 -----------------------
146 sysfs driver attribute: interface_version
148 Version of the thinkpad-acpi sysfs interface, as an unsigned long
149 (output in hex format: 0xAAAABBCC), where:
158 The sysfs interface version changelog for the driver can be found at the
159 end of this document. Changes to the sysfs interface done by the kernel
160 subsystems are not documented here, nor are they tracked by this
163 Changes to the thinkpad-acpi sysfs interface are only considered
164 non-experimental when they are submitted to Linux mainline, at which
165 point the changes in this interface are documented and interface_version
166 may be updated. If you are using any thinkpad-acpi features not yet
167 sent to mainline for merging, you do so on your own risk: these features
168 may disappear, or be implemented in a different and incompatible way by
169 the time they are merged in Linux mainline.
171 Changes that are backwards-compatible by nature (e.g. the addition of
172 attributes that do not change the way the other attributes work) do not
173 always warrant an update of interface_version. Therefore, one must
174 expect that an attribute might not be there, and deal with it properly
175 (an attribute not being there *is* a valid way to make it clear that a
176 feature is not available in sysfs).
182 procfs: /proc/acpi/ibm/hotkey
184 sysfs device attribute: hotkey_*
186 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
187 some important events and also keyboard hot key presses to the operating
188 system. Enabling the hotkey functionality of thinkpad-acpi signals the
189 firmware that such a driver is present, and modifies how the ThinkPad
190 firmware will behave in many situations.
192 The driver enables the HKEY ("hot key") event reporting automatically
193 when loaded, and disables it when it is removed.
195 The driver will report HKEY events in the following format::
197 ibm/hotkey HKEY 00000080 0000xxxx
199 Some of these events refer to hot key presses, but not all of them.
201 The driver will generate events over the input layer for hot keys and
202 radio switches, and over the ACPI netlink layer for other events. The
203 input layer support accepts the standard IOCTLs to remap the keycodes
204 assigned to each hot key.
206 The hot key bit mask allows some control over which hot keys generate
207 events. If a key is "masked" (bit set to 0 in the mask), the firmware
208 will handle it. If it is "unmasked", it signals the firmware that
209 thinkpad-acpi would prefer to handle it, if the firmware would be so
210 kind to allow it (and it often doesn't!).
212 Not all bits in the mask can be modified. Not all bits that can be
213 modified do anything. Not all hot keys can be individually controlled
214 by the mask. Some models do not support the mask at all. The behaviour
215 of the mask is, therefore, highly dependent on the ThinkPad model.
217 The driver will filter out any unmasked hotkeys, so even if the firmware
218 doesn't allow disabling an specific hotkey, the driver will not report
219 events for unmasked hotkeys.
221 Note that unmasking some keys prevents their default behavior. For
222 example, if Fn+F5 is unmasked, that key will no longer enable/disable
223 Bluetooth by itself in firmware.
225 Note also that not all Fn key combinations are supported through ACPI
226 depending on the ThinkPad model and firmware version. On those
227 ThinkPads, it is still possible to support some extra hotkeys by
228 polling the "CMOS NVRAM" at least 10 times per second. The driver
229 attempts to enables this functionality automatically when required.
234 The following commands can be written to the /proc/acpi/ibm/hotkey file::
236 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
237 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
238 ... any other 8-hex-digit mask ...
239 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
241 The following commands have been deprecated and will cause the kernel
244 echo enable > /proc/acpi/ibm/hotkey -- does nothing
245 echo disable > /proc/acpi/ibm/hotkey -- returns an error
247 The procfs interface does not support NVRAM polling control. So as to
248 maintain maximum bug-to-bug compatibility, it does not report any masks,
249 nor does it allow one to manipulate the hot key mask when the firmware
250 does not support masks at all, even if NVRAM polling is in use.
256 DEPRECATED, WILL BE REMOVED SOON.
261 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
263 Returns the hot keys mask when thinkpad-acpi was loaded.
264 Upon module unload, the hot keys mask will be restored
265 to this value. This is always 0x80c, because those are
266 the hotkeys that were supported by ancient firmware
267 without mask support.
270 DEPRECATED, WILL BE REMOVED SOON.
276 bit mask to enable reporting (and depending on
277 the firmware, ACPI event generation) for each hot key
278 (see above). Returns the current status of the hot keys
279 mask, and allows one to modify it.
282 bit mask that should enable event reporting for all
283 supported hot keys, when echoed to hotkey_mask above.
284 Unless you know which events need to be handled
285 passively (because the firmware *will* handle them
286 anyway), do *not* use hotkey_all_mask. Use
287 hotkey_recommended_mask, instead. You have been warned.
289 hotkey_recommended_mask:
290 bit mask that should enable event reporting for all
291 supported hot keys, except those which are always
292 handled by the firmware anyway. Echo it to
293 hotkey_mask above, to use. This is the default mask
297 bit mask that selects which hot keys will the driver
298 poll the NVRAM for. This is auto-detected by the driver
299 based on the capabilities reported by the ACPI firmware,
300 but it can be overridden at runtime.
302 Hot keys whose bits are set in hotkey_source_mask are
303 polled for in NVRAM, and reported as hotkey events if
304 enabled in hotkey_mask. Only a few hot keys are
305 available through CMOS NVRAM polling.
307 Warning: when in NVRAM mode, the volume up/down/mute
308 keys are synthesized according to changes in the mixer,
309 which uses a single volume up or volume down hotkey
310 press to unmute, as per the ThinkPad volume mixer user
311 interface. When in ACPI event mode, volume up/down/mute
312 events are reported by the firmware and can behave
313 differently (and that behaviour changes with firmware
314 version -- not just with firmware models -- as well as
318 frequency in Hz for hot key polling. It must be between
319 0 and 25 Hz. Polling is only carried out when strictly
322 Setting hotkey_poll_freq to zero disables polling, and
323 will cause hot key presses that require NVRAM polling
324 to never be reported.
326 Setting hotkey_poll_freq too low may cause repeated
327 pressings of the same hot key to be misreported as a
328 single key press, or to not even be detected at all.
329 The recommended polling frequency is 10Hz.
332 If the ThinkPad has a hardware radio switch, this
333 attribute will read 0 if the switch is in the "radios
334 disabled" position, and 1 if the switch is in the
335 "radios enabled" position.
337 This attribute has poll()/select() support.
340 If the ThinkPad has tablet capabilities, this attribute
341 will read 0 if the ThinkPad is in normal mode, and
342 1 if the ThinkPad is in tablet mode.
344 This attribute has poll()/select() support.
347 Set to 1 if the system is waking up because the user
348 requested a bay ejection. Set to 2 if the system is
349 waking up because the user requested the system to
350 undock. Set to zero for normal wake-ups or wake-ups
351 due to unknown reasons.
353 This attribute has poll()/select() support.
355 wakeup_hotunplug_complete:
356 Set to 1 if the system was waken up because of an
357 undock or bay ejection request, and that request
358 was successfully completed. At this point, it might
359 be useful to send the system back to sleep, at the
360 user's choice. Refer to HKEY events 0x4003 and
363 This attribute has poll()/select() support.
368 A Hot key is mapped to a single input layer EV_KEY event, possibly
369 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
370 code. An EV_SYN event will always be generated to mark the end of the
373 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
374 used as a helper to remap keys, only. They are particularly useful when
375 remapping KEY_UNKNOWN keys.
377 The events are available in an input device, with the following id:
379 ============== ==============================
381 vendor 0x1014 (PCI_VENDOR_ID_IBM) or
382 0x17aa (PCI_VENDOR_ID_LENOVO)
383 product 0x5054 ("TP")
385 ============== ==============================
387 The version will have its LSB incremented if the keymap changes in a
388 backwards-compatible way. The MSB shall always be 0x41 for this input
389 device. If the MSB is not 0x41, do not use the device as described in
390 this section, as it is either something else (e.g. another input device
391 exported by a thinkpad driver, such as HDAPS) or its functionality has
392 been changed in a non-backwards compatible way.
394 Adding other event types for other functionalities shall be considered a
395 backwards-compatible change for this input device.
397 Thinkpad-acpi Hot Key event map (version 0x4101):
399 ======= ======= ============== ==============================================
402 ======= ======= ============== ==============================================
405 0x1002 0x01 FN+F2 IBM: battery (rare)
408 0x1003 0x02 FN+F3 Many IBM models always report
409 this hot key, even with hot keys
410 disabled or with Fn+F3 masked
412 IBM: screen lock, often turns
413 off the ThinkLight as side-effect
416 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
417 semantics, i.e. sleep-to-RAM).
418 It always generates some kind
419 of event, either the hot key
420 event or an ACPI sleep button
421 event. The firmware may
422 refuse to generate further FN+F4
423 key presses until a S3 or S4 ACPI
424 sleep cycle is performed or some
427 0x1005 0x04 FN+F5 Radio. Enables/disables
428 the internal Bluetooth hardware
429 and W-WAN card if left in control
430 of the firmware. Does not affect
432 Should be used to turn on/off all
433 radios (Bluetooth+W-WAN+WLAN),
438 0x1007 0x06 FN+F7 Video output cycle.
439 Do you feel lucky today?
441 0x1008 0x07 FN+F8 IBM: toggle screen expand
442 Lenovo: configure UltraNav,
443 or toggle screen expand
451 0x100C 0x0B FN+F12 Sleep to disk. You are always
452 supposed to handle it yourself,
453 either through the ACPI event,
454 or through a hotkey event.
455 The firmware may refuse to
456 generate further FN+F12 key
457 press events until a S3 or S4
458 ACPI sleep cycle is performed,
461 0x100D 0x0C FN+BACKSPACE -
462 0x100E 0x0D FN+INSERT -
463 0x100F 0x0E FN+DELETE -
465 0x1010 0x0F FN+HOME Brightness up. This key is
466 always handled by the firmware
467 in IBM ThinkPads, even when
468 unmasked. Just leave it alone.
469 For Lenovo ThinkPads with a new
470 BIOS, it has to be handled either
471 by the ACPI OSI, or by userspace.
472 The driver does the right thing,
473 never mess with this.
474 0x1011 0x10 FN+END Brightness down. See brightness
477 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
478 always handled by the firmware,
481 0x1013 0x12 FN+PGDOWN -
483 0x1014 0x13 FN+SPACE Zoom key
485 0x1015 0x14 VOLUME UP Internal mixer volume up. This
486 key is always handled by the
487 firmware, even when unmasked.
488 NOTE: Lenovo seems to be changing
490 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
491 key is always handled by the
492 firmware, even when unmasked.
493 NOTE: Lenovo seems to be changing
495 0x1017 0x16 MUTE Mute internal mixer. This
496 key is always handled by the
497 firmware, even when unmasked.
499 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
506 ======= ======= ============== ==============================================
508 The ThinkPad firmware does not allow one to differentiate when most hot
509 keys are pressed or released (either that, or we don't know how to, yet).
510 For these keys, the driver generates a set of events for a key press and
511 immediately issues the same set of events for a key release. It is
512 unknown by the driver if the ThinkPad firmware triggered these events on
513 hot key press or release, but the firmware will do it for either one, not
516 If a key is mapped to KEY_RESERVED, it generates no input events at all.
517 If a key is mapped to KEY_UNKNOWN, it generates an input event that
518 includes an scan code. If a key is mapped to anything else, it will
519 generate input device EV_KEY events.
521 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
524 ============== ==============================================
525 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
526 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
527 ============== ==============================================
529 Non hotkey ACPI HKEY event map
530 ------------------------------
532 Events that are never propagated by the driver:
534 ====== ==================================================
535 0x2304 System is waking up from suspend to undock
536 0x2305 System is waking up from suspend to eject bay
537 0x2404 System is waking up from hibernation to undock
538 0x2405 System is waking up from hibernation to eject bay
541 0x5009 Tablet swivel: switched to tablet mode
542 0x500A Tablet swivel: switched to normal mode
543 0x5010 Brightness level changed/control event
544 0x6000 KEYBOARD: Numlock key pressed
545 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
546 0x7000 Radio Switch may have changed state
547 ====== ==================================================
550 Events that are propagated by the driver to userspace:
552 ====== =====================================================
553 0x2313 ALARM: System is waking up from suspend because
554 the battery is nearly empty
555 0x2413 ALARM: System is waking up from hibernation because
556 the battery is nearly empty
557 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
558 0x3006 Bay hotplug request (hint to power up SATA link when
559 the optical drive tray is ejected)
560 0x4003 Undocked (see 0x2x04), can sleep again
561 0x4010 Docked into hotplug port replicator (non-ACPI dock)
562 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
563 0x500B Tablet pen inserted into its storage bay
564 0x500C Tablet pen removed from its storage bay
565 0x6011 ALARM: battery is too hot
566 0x6012 ALARM: battery is extremely hot
567 0x6021 ALARM: a sensor is too hot
568 0x6022 ALARM: a sensor is extremely hot
569 0x6030 System thermal table changed
570 0x6032 Thermal Control command set completion (DYTC, Windows)
571 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
572 0x60C0 X1 Yoga 2016, Tablet mode status changed
573 0x60F0 Thermal Transformation changed (GMTS, Windows)
574 ====== =====================================================
576 Battery nearly empty alarms are a last resort attempt to get the
577 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
578 cleanly (0x2413) before power is lost. They must be acted upon, as the
579 wake up caused by the firmware will have negated most safety nets...
581 When any of the "too hot" alarms happen, according to Lenovo the user
582 should suspend or hibernate the laptop (and in the case of battery
583 alarms, unplug the AC adapter) to let it cool down. These alarms do
584 signal that something is wrong, they should never happen on normal
585 operating conditions.
587 The "extremely hot" alarms are emergencies. According to Lenovo, the
588 operating system is to force either an immediate suspend or hibernate
589 cycle, or a system shutdown. Obviously, something is very wrong if this
593 Brightness hotkey notes
594 ^^^^^^^^^^^^^^^^^^^^^^^
596 Don't mess with the brightness hotkeys in a Thinkpad. If you want
597 notifications for OSD, use the sysfs backlight class event support.
599 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
600 automatically for the cases were userspace has to do something to
601 implement brightness changes. When you override these events, you will
602 either fail to handle properly the ThinkPads that require explicit
603 action to change backlight brightness, or the ThinkPads that require
604 that no action be taken to work properly.
610 procfs: /proc/acpi/ibm/bluetooth
612 sysfs device attribute: bluetooth_enable (deprecated)
614 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
616 This feature shows the presence and current state of a ThinkPad
617 Bluetooth device in the internal ThinkPad CDC slot.
619 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
620 so it is kept across reboots and power-off.
625 If Bluetooth is installed, the following commands can be used::
627 echo enable > /proc/acpi/ibm/bluetooth
628 echo disable > /proc/acpi/ibm/bluetooth
633 If the Bluetooth CDC card is installed, it can be enabled /
634 disabled through the "bluetooth_enable" thinkpad-acpi device
635 attribute, and its current status can also be queried.
639 - 0: disables Bluetooth / Bluetooth is disabled
640 - 1: enables Bluetooth / Bluetooth is enabled.
642 Note: this interface has been superseded by the generic rfkill
643 class. It has been deprecated, and it will be removed in year
646 rfkill controller switch "tpacpi_bluetooth_sw": refer to
647 Documentation/driver-api/rfkill.rst for details.
650 Video output control -- /proc/acpi/ibm/video
651 --------------------------------------------
653 This feature allows control over the devices used for video output -
654 LCD, CRT or DVI (if available). The following commands are available::
656 echo lcd_enable > /proc/acpi/ibm/video
657 echo lcd_disable > /proc/acpi/ibm/video
658 echo crt_enable > /proc/acpi/ibm/video
659 echo crt_disable > /proc/acpi/ibm/video
660 echo dvi_enable > /proc/acpi/ibm/video
661 echo dvi_disable > /proc/acpi/ibm/video
662 echo auto_enable > /proc/acpi/ibm/video
663 echo auto_disable > /proc/acpi/ibm/video
664 echo expand_toggle > /proc/acpi/ibm/video
665 echo video_switch > /proc/acpi/ibm/video
668 Access to this feature is restricted to processes owning the
669 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
670 enough with some versions of X.org to crash it.
672 Each video output device can be enabled or disabled individually.
673 Reading /proc/acpi/ibm/video shows the status of each device.
675 Automatic video switching can be enabled or disabled. When automatic
676 video switching is enabled, certain events (e.g. opening the lid,
677 docking or undocking) cause the video output device to change
678 automatically. While this can be useful, it also causes flickering
679 and, on the X40, video corruption. By disabling automatic switching,
680 the flickering or video corruption can be avoided.
682 The video_switch command cycles through the available video outputs
683 (it simulates the behavior of Fn-F7).
685 Video expansion can be toggled through this feature. This controls
686 whether the display is expanded to fill the entire LCD screen when a
687 mode with less than full resolution is used. Note that the current
688 video expansion status cannot be determined through this feature.
690 Note that on many models (particularly those using Radeon graphics
691 chips) the X driver configures the video card in a way which prevents
692 Fn-F7 from working. This also disables the video output switching
693 features of this driver, as it uses the same ACPI methods as
694 Fn-F7. Video switching on the console should still work.
696 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
702 procfs: /proc/acpi/ibm/light
704 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
709 The ThinkLight status can be read and set through the procfs interface. A
710 few models which do not make the status available will show the ThinkLight
711 status as "unknown". The available commands are::
713 echo on > /proc/acpi/ibm/light
714 echo off > /proc/acpi/ibm/light
719 The ThinkLight sysfs interface is documented by the LED class
720 documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
721 is "tpacpi::thinklight".
723 Due to limitations in the sysfs LED class, if the status of the ThinkLight
724 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
725 It is impossible to know if the status returned through sysfs is valid.
731 procfs: /proc/acpi/ibm/cmos
733 sysfs device attribute: cmos_command
735 This feature is mostly used internally by the ACPI firmware to keep the legacy
736 CMOS NVRAM bits in sync with the current machine state, and to record this
737 state so that the ThinkPad will retain such settings across reboots.
739 Some of these commands actually perform actions in some ThinkPad models, but
740 this is expected to disappear more and more in newer models. As an example, in
741 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
742 real, but commands 0 to 2 don't control the mixer anymore (they have been
743 phased out) and just update the NVRAM.
745 The range of valid cmos command numbers is 0 to 21, but not all have an
746 effect and the behavior varies from model to model. Here is the behavior
747 on the X40 (tpb is the ThinkPad Buttons utility):
749 - 0 - Related to "Volume down" key press
750 - 1 - Related to "Volume up" key press
751 - 2 - Related to "Mute on" key press
752 - 3 - Related to "Access IBM" key press
753 - 4 - Related to "LCD brightness up" key press
754 - 5 - Related to "LCD brightness down" key press
755 - 11 - Related to "toggle screen expansion" key press/function
756 - 12 - Related to "ThinkLight on"
757 - 13 - Related to "ThinkLight off"
758 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
760 The cmos command interface is prone to firmware split-brain problems, as
761 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
762 exported just as a debug tool.
768 procfs: /proc/acpi/ibm/led
769 sysfs attributes: as per LED class, see below for names
771 Some of the LED indicators can be controlled through this feature. On
772 some older ThinkPad models, it is possible to query the status of the
773 LED indicators as well. Newer ThinkPads cannot query the real status
774 of the LED indicators.
776 Because misuse of the LEDs could induce an unaware user to perform
777 dangerous actions (like undocking or ejecting a bay device while the
778 buses are still active), or mask an important alarm (such as a nearly
779 empty battery, or a broken battery), access to most LEDs is
782 Unrestricted access to all LEDs requires that thinkpad-acpi be
783 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
784 Distributions must never enable this option. Individual users that
785 are aware of the consequences are welcome to enabling it.
787 Audio mute and microphone mute LEDs are supported, but currently not
788 visible to userspace. They are used by the snd-hda-intel audio driver.
793 The available commands are::
795 echo '<LED number> on' >/proc/acpi/ibm/led
796 echo '<LED number> off' >/proc/acpi/ibm/led
797 echo '<LED number> blink' >/proc/acpi/ibm/led
799 The <LED number> range is 0 to 15. The set of LEDs that can be
800 controlled varies from model to model. Here is the common ThinkPad
804 - 1 - battery (orange)
805 - 2 - battery (green)
808 - 5 - UltraBase battery slot
815 - 13, 14, 15 - (unknown)
817 All of the above can be turned on and off and can be made to blink.
822 The ThinkPad LED sysfs interface is described in detail by the LED class
823 documentation, in Documentation/leds/leds-class.rst.
825 The LEDs are named (in LED ID order, from 0 to 12):
826 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
827 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
828 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
829 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
830 "tpacpi::thinkvantage".
832 Due to limitations in the sysfs LED class, if the status of the LED
833 indicators cannot be read due to an error, thinkpad-acpi will report it as
834 a brightness of zero (same as LED off).
836 If the thinkpad firmware doesn't support reading the current status,
837 trying to read the current LED brightness will just return whatever
838 brightness was last written to that attribute.
840 These LEDs can blink using hardware acceleration. To request that a
841 ThinkPad indicator LED should blink in hardware accelerated mode, use the
842 "timer" trigger, and leave the delay_on and delay_off parameters set to
843 zero (to request hardware acceleration autodetection).
845 LEDs that are known not to exist in a given ThinkPad model are not
846 made available through the sysfs interface. If you have a dock and you
847 notice there are LEDs listed for your ThinkPad that do not exist (and
848 are not in the dock), or if you notice that there are missing LEDs,
849 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
852 ACPI sounds -- /proc/acpi/ibm/beep
853 ----------------------------------
855 The BEEP method is used internally by the ACPI firmware to provide
856 audible alerts in various situations. This feature allows the same
857 sounds to be triggered manually.
859 The commands are non-negative integer numbers::
861 echo <number> >/proc/acpi/ibm/beep
863 The valid <number> range is 0 to 17. Not all numbers trigger sounds
864 and the sounds vary from model to model. Here is the behavior on the
867 - 0 - stop a sound in progress (but use 17 to stop 16)
868 - 2 - two beeps, pause, third beep ("low battery")
870 - 4 - high, followed by low-pitched beep ("unable")
872 - 6 - very high, followed by high-pitched beep ("AC/DC")
873 - 7 - high-pitched beep
874 - 9 - three short beeps
875 - 10 - very long beep
876 - 12 - low-pitched beep
877 - 15 - three high-pitched beeps repeating constantly, stop with 0
878 - 16 - one medium-pitched beep repeating constantly, stop with 17
885 procfs: /proc/acpi/ibm/thermal
887 sysfs device attributes: (hwmon "thinkpad") temp*_input
889 Most ThinkPads include six or more separate temperature sensors but only
890 expose the CPU temperature through the standard ACPI methods. This
891 feature shows readings from up to eight different sensors on older
892 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
894 For example, on the X40, a typical output may be:
897 42 42 45 41 36 -128 33 -128
899 On the T43/p, a typical output may be:
902 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
904 The mapping of thermal sensors to physical locations varies depending on
905 system-board model (and thus, on ThinkPad model).
907 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
908 tries to track down these locations for various models.
910 Most (newer?) models seem to follow this pattern:
913 - 2: (depends on model)
914 - 3: (depends on model)
916 - 5: Main battery: main sensor
917 - 6: Bay battery: main sensor
918 - 7: Main battery: secondary sensor
919 - 8: Bay battery: secondary sensor
920 - 9-15: (depends on model)
922 For the R51 (source: Thomas Gruber):
927 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
928 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
930 - 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
932 - 9: MCH (northbridge) to DRAM Bus
933 - 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
935 - 11: Power regulator, underside of system board, below F2 key
937 The A31 has a very atypical layout for the thermal sensors
938 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
941 - 2: Main Battery: main sensor
943 - 4: Bay Battery: main sensor
944 - 5: MCH (northbridge)
946 - 7: Main Battery: secondary sensor
947 - 8: Bay Battery: secondary sensor
953 Readings from sensors that are not available return -128.
954 No commands can be written to this file.
959 Sensors that are not available return the ENXIO error. This
960 status may change at runtime, as there are hotplug thermal
961 sensors, like those inside the batteries and docks.
963 thinkpad-acpi thermal sensors are reported through the hwmon
964 subsystem, and follow all of the hwmon guidelines at
967 EXPERIMENTAL: Embedded controller register dump
968 -----------------------------------------------
970 This feature is not included in the thinkpad driver anymore.
971 Instead the EC can be accessed through /sys/kernel/debug/ec with
972 a userspace tool which can be found here:
973 ftp://ftp.suse.com/pub/people/trenn/sources/ec
975 Use it to determine the register holding the fan
976 speed on some models. To do that, do the following:
978 - make sure the battery is fully charged
979 - make sure the fan is running
980 - use above mentioned tool to read out the EC
982 Often fan and temperature values vary between
983 readings. Since temperatures don't change vary fast, you can take
984 several quick dumps to eliminate them.
986 You can use a similar method to figure out the meaning of other
987 embedded controller registers - e.g. make sure nothing else changes
988 except the charging or discharging battery to determine which
989 registers contain the current battery capacity, etc. If you experiment
990 with this, do send me your results (including some complete dumps with
991 a description of the conditions when they were taken.)
994 LCD brightness control
995 ----------------------
997 procfs: /proc/acpi/ibm/brightness
999 sysfs backlight device "thinkpad_screen"
1001 This feature allows software control of the LCD brightness on ThinkPad
1002 models which don't have a hardware brightness slider.
1004 It has some limitations: the LCD backlight cannot be actually turned
1005 on or off by this interface, it just controls the backlight brightness
1008 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1009 has eight brightness levels, ranging from 0 to 7. Some of the levels
1010 may not be distinct. Later Lenovo models that implement the ACPI
1011 display backlight brightness control methods have 16 levels, ranging
1014 For IBM ThinkPads, there are two interfaces to the firmware for direct
1015 brightness control, EC and UCMS (or CMOS). To select which one should be
1016 used, use the brightness_mode module parameter: brightness_mode=1 selects
1017 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1018 mode with NVRAM backing (so that brightness changes are remembered across
1021 The driver tries to select which interface to use from a table of
1022 defaults for each ThinkPad model. If it makes a wrong choice, please
1023 report this as a bug, so that we can fix it.
1025 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1027 When display backlight brightness controls are available through the
1028 standard ACPI interface, it is best to use it instead of this direct
1029 ThinkPad-specific interface. The driver will disable its native
1030 backlight brightness control interface if it detects that the standard
1031 ACPI interface is available in the ThinkPad.
1033 If you want to use the thinkpad-acpi backlight brightness control
1034 instead of the generic ACPI video backlight brightness control for some
1035 reason, you should use the acpi_backlight=vendor kernel parameter.
1037 The brightness_enable module parameter can be used to control whether
1038 the LCD brightness control feature will be enabled when available.
1039 brightness_enable=0 forces it to be disabled. brightness_enable=1
1040 forces it to be enabled when available, even if the standard ACPI
1041 interface is also available.
1046 The available commands are::
1048 echo up >/proc/acpi/ibm/brightness
1049 echo down >/proc/acpi/ibm/brightness
1050 echo 'level <level>' >/proc/acpi/ibm/brightness
1055 The interface is implemented through the backlight sysfs class, which is
1056 poorly documented at this time.
1058 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1059 it there will be the following attributes:
1062 Reads the maximum brightness the hardware can be set to.
1063 The minimum is always zero.
1066 Reads what brightness the screen is set to at this instant.
1069 Writes request the driver to change brightness to the
1070 given value. Reads will tell you what brightness the
1071 driver is trying to set the display to when "power" is set
1072 to zero and the display has not been dimmed by a kernel
1073 power management event.
1076 power management mode, where 0 is "display on", and 1 to 3
1077 will dim the display backlight to brightness level 0
1078 because thinkpad-acpi cannot really turn the backlight
1079 off. Kernel power management events can temporarily
1080 increase the current power management level, i.e. they can
1086 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1087 interface and the ACPI-based backlight level change interface
1088 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1089 at the same time. The two will interact in bad ways, do funny things,
1090 and maybe reduce the life of the backlight lamps by needlessly kicking
1091 its level up and down at every change.
1094 Volume control (Console Audio control)
1095 --------------------------------------
1097 procfs: /proc/acpi/ibm/volume
1099 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1101 NOTE: by default, the volume control interface operates in read-only
1102 mode, as it is supposed to be used for on-screen-display purposes.
1103 The read/write mode can be enabled through the use of the
1104 "volume_control=1" module parameter.
1106 NOTE: distros are urged to not enable volume_control by default, this
1107 should be done by the local admin only. The ThinkPad UI is for the
1108 console audio control to be done through the volume keys only, and for
1109 the desktop environment to just provide on-screen-display feedback.
1110 Software volume control should be done only in the main AC97/HDA
1114 About the ThinkPad Console Audio control
1115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1117 ThinkPads have a built-in amplifier and muting circuit that drives the
1118 console headphone and speakers. This circuit is after the main AC97
1119 or HDA mixer in the audio path, and under exclusive control of the
1122 ThinkPads have three special hotkeys to interact with the console
1123 audio control: volume up, volume down and mute.
1125 It is worth noting that the normal way the mute function works (on
1126 ThinkPads that do not have a "mute LED") is:
1128 1. Press mute to mute. It will *always* mute, you can press it as
1129 many times as you want, and the sound will remain mute.
1131 2. Press either volume key to unmute the ThinkPad (it will _not_
1132 change the volume, it will just unmute).
1134 This is a very superior design when compared to the cheap software-only
1135 mute-toggle solution found on normal consumer laptops: you can be
1136 absolutely sure the ThinkPad will not make noise if you press the mute
1137 button, no matter the previous state.
1139 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1140 amplifiers driving the speakers and headphone output, and the firmware
1141 also handles volume control for the headphone and speakers on these
1142 ThinkPads without any help from the operating system (this volume
1143 control stage exists after the main AC97 or HDA mixer in the audio
1146 The newer Lenovo models only have firmware mute control, and depend on
1147 the main HDA mixer to do volume control (which is done by the operating
1148 system). In this case, the volume keys are filtered out for unmute
1149 key press (there are some firmware bugs in this area) and delivered as
1150 normal key presses to the operating system (thinkpad-acpi is not
1154 The ThinkPad-ACPI volume control
1155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1157 The preferred way to interact with the Console Audio control is the
1160 The legacy procfs interface allows one to read the current state,
1161 and if volume control is enabled, accepts the following commands::
1163 echo up >/proc/acpi/ibm/volume
1164 echo down >/proc/acpi/ibm/volume
1165 echo mute >/proc/acpi/ibm/volume
1166 echo unmute >/proc/acpi/ibm/volume
1167 echo 'level <level>' >/proc/acpi/ibm/volume
1169 The <level> number range is 0 to 14 although not all of them may be
1170 distinct. To unmute the volume after the mute command, use either the
1171 up or down command (the level command will not unmute the volume), or
1174 You can use the volume_capabilities parameter to tell the driver
1175 whether your thinkpad has volume control or mute-only control:
1176 volume_capabilities=1 for mixers with mute and volume control,
1177 volume_capabilities=2 for mixers with only mute control.
1179 If the driver misdetects the capabilities for your ThinkPad model,
1180 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1181 can update the driver.
1183 There are two strategies for volume control. To select which one
1184 should be used, use the volume_mode module parameter: volume_mode=1
1185 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1186 (so that volume/mute changes are remembered across shutdown/reboot).
1188 The driver will operate in volume_mode=3 by default. If that does not
1189 work well on your ThinkPad model, please report this to
1190 ibm-acpi-devel@lists.sourceforge.net.
1192 The driver supports the standard ALSA module parameters. If the ALSA
1193 mixer is disabled, the driver will disable all volume functionality.
1196 Fan control and monitoring: fan speed, fan enable/disable
1197 ---------------------------------------------------------
1199 procfs: /proc/acpi/ibm/fan
1201 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1203 sysfs hwmon driver attributes: fan_watchdog
1206 fan control operations are disabled by default for
1207 safety reasons. To enable them, the module parameter "fan_control=1"
1208 must be given to thinkpad-acpi.
1210 This feature attempts to show the current fan speed, control mode and
1211 other fan data that might be available. The speed is read directly
1212 from the hardware registers of the embedded controller. This is known
1213 to work on later R, T, X and Z series ThinkPads but may show a bogus
1214 value on other models.
1216 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1217 controlled separately, it shares the main fan control.
1222 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1223 stops the fan. The higher the level, the higher the fan speed, although
1224 adjacent levels often map to the same fan speed. 7 is the highest
1225 level, where the fan reaches the maximum recommended speed.
1227 Level "auto" means the EC changes the fan level according to some
1228 internal algorithm, usually based on readings from the thermal sensors.
1230 There is also a "full-speed" level, also known as "disengaged" level.
1231 In this level, the EC disables the speed-locked closed-loop fan control,
1232 and drives the fan as fast as it can go, which might exceed hardware
1233 limits, so use this level with caution.
1235 The fan usually ramps up or down slowly from one speed to another, and
1236 it is normal for the EC to take several seconds to react to fan
1237 commands. The full-speed level may take up to two minutes to ramp up to
1238 maximum speed, and in some ThinkPads, the tachometer readings go stale
1239 while the EC is transitioning to the full-speed level.
1241 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1242 monitoring all of the temperature sensor readings and you are ready to
1243 enable it if necessary to avoid overheating.
1245 An enabled fan in level "auto" may stop spinning if the EC decides the
1246 ThinkPad is cool enough and doesn't need the extra airflow. This is
1247 normal, and the EC will spin the fan up if the various thermal readings
1250 On the X40, this seems to depend on the CPU and HDD temperatures.
1251 Specifically, the fan is turned on when either the CPU temperature
1252 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1253 fan is turned off when the CPU temperature drops to 49 degrees and the
1254 HDD temperature drops to 41 degrees. These thresholds cannot
1255 currently be controlled.
1257 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1258 certain conditions are met. It will override any fan programming done
1259 through thinkpad-acpi.
1261 The thinkpad-acpi kernel driver can be programmed to revert the fan
1262 level to a safe setting if userspace does not issue one of the procfs
1263 fan commands: "enable", "disable", "level" or "watchdog", or if there
1264 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1265 set to 1, manual mode) within a configurable amount of time of up to
1266 120 seconds. This functionality is called fan safety watchdog.
1268 Note that the watchdog timer stops after it enables the fan. It will be
1269 rearmed again automatically (using the same interval) when one of the
1270 above mentioned fan commands is received. The fan watchdog is,
1271 therefore, not suitable to protect against fan mode changes made through
1272 means other than the "enable", "disable", and "level" procfs fan
1273 commands, or the hwmon fan control sysfs interface.
1278 The fan may be enabled or disabled with the following commands::
1280 echo enable >/proc/acpi/ibm/fan
1281 echo disable >/proc/acpi/ibm/fan
1283 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1284 will try to place it in a safe level if it is too slow or disabled.
1286 The fan level can be controlled with the command::
1288 echo 'level <level>' > /proc/acpi/ibm/fan
1290 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1291 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1292 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1293 "full-speed", and reports it as "disengaged" for backwards
1296 On the X31 and X40 (and ONLY on those models), the fan speed can be
1297 controlled to a certain degree. Once the fan is running, it can be
1298 forced to run faster or slower with the following command::
1300 echo 'speed <speed>' > /proc/acpi/ibm/fan
1302 The sustainable range of fan speeds on the X40 appears to be from about
1303 3700 to about 7350. Values outside this range either do not have any
1304 effect or the fan speed eventually settles somewhere in that range. The
1305 fan cannot be stopped or started with this command. This functionality
1306 is incomplete, and not available through the sysfs interface.
1308 To program the safety watchdog, use the "watchdog" command::
1310 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1312 If you want to disable the watchdog, use 0 as the interval.
1317 The sysfs interface follows the hwmon subsystem guidelines for the most
1318 part, and the exception is the fan safety watchdog.
1320 Writes to any of the sysfs attributes may return the EINVAL error if
1321 that operation is not supported in a given ThinkPad or if the parameter
1322 is out-of-bounds, and EPERM if it is forbidden. They may also return
1323 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1326 Features not yet implemented by the driver return ENOSYS.
1328 hwmon device attribute pwm1_enable:
1329 - 0: PWM offline (fan is set to full-speed mode)
1330 - 1: Manual PWM control (use pwm1 to set fan level)
1331 - 2: Hardware PWM control (EC "auto" mode)
1332 - 3: reserved (Software PWM control, not implemented yet)
1334 Modes 0 and 2 are not supported by all ThinkPads, and the
1335 driver is not always able to detect this. If it does know a
1336 mode is unsupported, it will return -EINVAL.
1338 hwmon device attribute pwm1:
1339 Fan level, scaled from the firmware values of 0-7 to the hwmon
1340 scale of 0-255. 0 means fan stopped, 255 means highest normal
1343 This attribute only commands the fan if pmw1_enable is set to 1
1344 (manual PWM control).
1346 hwmon device attribute fan1_input:
1347 Fan tachometer reading, in RPM. May go stale on certain
1348 ThinkPads while the EC transitions the PWM to offline mode,
1349 which can take up to two minutes. May return rubbish on older
1352 hwmon device attribute fan2_input:
1353 Fan tachometer reading, in RPM, for the secondary fan.
1354 Available only on some ThinkPads. If the secondary fan is
1355 not installed, will always read 0.
1357 hwmon driver attribute fan_watchdog:
1358 Fan safety watchdog timer interval, in seconds. Minimum is
1359 1 second, maximum is 120 seconds. 0 disables the watchdog.
1361 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1363 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1364 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1365 would be the safest choice, though).
1371 procfs: /proc/acpi/ibm/wan
1373 sysfs device attribute: wwan_enable (deprecated)
1375 sysfs rfkill class: switch "tpacpi_wwan_sw"
1377 This feature shows the presence and current state of the built-in
1378 Wireless WAN device.
1380 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1381 so it is kept across reboots and power-off.
1383 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1384 ThinkPad models which come with this module installed.
1389 If the W-WAN card is installed, the following commands can be used::
1391 echo enable > /proc/acpi/ibm/wan
1392 echo disable > /proc/acpi/ibm/wan
1397 If the W-WAN card is installed, it can be enabled /
1398 disabled through the "wwan_enable" thinkpad-acpi device
1399 attribute, and its current status can also be queried.
1402 - 0: disables WWAN card / WWAN card is disabled
1403 - 1: enables WWAN card / WWAN card is enabled.
1405 Note: this interface has been superseded by the generic rfkill
1406 class. It has been deprecated, and it will be removed in year
1409 rfkill controller switch "tpacpi_wwan_sw": refer to
1410 Documentation/driver-api/rfkill.rst for details.
1416 procfs: /proc/acpi/ibm/lcdshadow
1418 Some newer T480s and T490s ThinkPads provide a feature called
1419 PrivacyGuard. By turning this feature on, the usable vertical and
1420 horizontal viewing angles of the LCD can be limited (as if some privacy
1421 screen was applied manually in front of the display).
1426 The available commands are::
1428 echo '0' >/proc/acpi/ibm/lcdshadow
1429 echo '1' >/proc/acpi/ibm/lcdshadow
1431 The first command ensures the best viewing angle and the latter one turns
1432 on the feature, restricting the viewing angles.
1438 This feature is considered EXPERIMENTAL because it has not been extensively
1439 tested and validated in various ThinkPad models yet. The feature may not
1440 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1441 the experimental=1 parameter when loading the module.
1443 sysfs rfkill class: switch "tpacpi_uwb_sw"
1445 This feature exports an rfkill controller for the UWB device, if one is
1446 present and enabled in the BIOS.
1451 rfkill controller switch "tpacpi_uwb_sw": refer to
1452 Documentation/driver-api/rfkill.rst for details.
1457 sysfs device attribute: adaptive_kbd_mode
1459 This sysfs attribute controls the keyboard "face" that will be shown on the
1460 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1464 - 2 = Web-browser mode
1465 - 3 = Web-conference mode
1469 For more details about which buttons will appear depending on the mode, please
1470 review the laptop's user guide:
1471 http://www.lenovo.com/shop/americas/content/user_guides/x1carbon_2_ug_en.pdf
1473 Multiple Commands, Module Parameters
1474 ------------------------------------
1476 Multiple commands can be written to the proc files in one shot by
1477 separating them with commas, for example::
1479 echo enable,0xffff > /proc/acpi/ibm/hotkey
1480 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1482 Commands can also be specified when loading the thinkpad-acpi module,
1485 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1488 Enabling debugging output
1489 -------------------------
1491 The module takes a debug parameter which can be used to selectively
1492 enable various classes of debugging output, for example::
1494 modprobe thinkpad_acpi debug=0xffff
1496 will enable all debugging output classes. It takes a bitmask, so
1497 to enable more than one output class, just add their values.
1499 ============= ======================================
1500 Debug bitmask Description
1501 ============= ======================================
1502 0x8000 Disclose PID of userspace programs
1503 accessing some functions of the driver
1504 0x0001 Initialization and probing
1506 0x0004 RF Transmitter control (RFKILL)
1507 (bluetooth, WWAN, UWB...)
1508 0x0008 HKEY event interface, hotkeys
1510 0x0020 Backlight brightness
1511 0x0040 Audio mixer/volume control
1512 ============= ======================================
1514 There is also a kernel build option to enable more debugging
1515 information, which may be necessary to debug driver problems.
1517 The level of debugging information output by the driver can be changed
1518 at runtime through sysfs, using the driver attribute debug_level. The
1519 attribute takes the same bitmask as the debug module parameter above.
1522 Force loading of module
1523 -----------------------
1525 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1526 the module parameter force_load=1. Regardless of whether this works or
1527 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1530 Sysfs interface changelog
1531 ^^^^^^^^^^^^^^^^^^^^^^^^^
1533 ========= ===============================================================
1534 0x000100: Initial sysfs support, as a single platform driver and
1536 0x000200: Hot key support for 32 hot keys, and radio slider switch
1538 0x010000: Hot keys are now handled by default over the input
1539 layer, the radio switch generates input event EV_RADIO,
1540 and the driver enables hot key handling by default in
1543 0x020000: ABI fix: added a separate hwmon platform device and
1544 driver, which must be located by name (thinkpad)
1545 and the hwmon class for libsensors4 (lm-sensors 3)
1546 compatibility. Moved all hwmon attributes to this
1547 new platform device.
1549 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1550 support. If you must, use it to know you should not
1551 start a userspace NVRAM poller (allows to detect when
1552 NVRAM is compiled out by the user because it is
1553 unneeded/undesired in the first place).
1554 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1555 and proper hotkey_mask semantics (version 8 of the
1556 NVRAM polling patch). Some development snapshots of
1557 0.18 had an earlier version that did strange things
1560 0x020200: Add poll()/select() support to the following attributes:
1561 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1563 0x020300: hotkey enable/disable support removed, attributes
1564 hotkey_bios_enabled and hotkey_enable deprecated and
1567 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1568 to not exist in a given model are not registered with
1569 the LED sysfs class anymore.
1571 0x020500: Updated hotkey driver, hotkey_mask is always available
1572 and it is always able to disable hot keys. Very old
1573 thinkpads are properly supported. hotkey_bios_mask
1574 is deprecated and marked for removal.
1576 0x020600: Marker for backlight change event support.
1578 0x020700: Support for mute-only mixers.
1579 Volume control in read-only mode by default.
1580 Marker for ALSA mixer support.
1582 0x030000: Thermal and fan sysfs attributes were moved to the hwmon
1583 device instead of being attached to the backing platform
1585 ========= ===============================================================
git.samba.org / sfrench / cifs-2.6.git / blob