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1===========================
2ThinkPad ACPI Extras Driver
3===========================
4
5Version 0.25
6
7October 16th, 2013
8
9- Borislav Deianov <borislav@users.sf.net>
10- Henrique de Moraes Holschuh <hmh@hmh.eng.br>
11
12http://ibm-acpi.sf.net/
13
14This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
15supports various features of these laptops which are accessible
16through the ACPI and ACPI EC framework, but not otherwise fully
17supported by the generic Linux ACPI drivers.
18
19This driver used to be named ibm-acpi until kernel 2.6.21 and release
200.13-20070314. It used to be in the drivers/acpi tree, but it was
21moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
222.6.22, and release 0.14. It was moved to drivers/platform/x86 for
23kernel 2.6.29 and release 0.22.
24
25The driver is named "thinkpad-acpi". In some places, like module
26names and log messages, "thinkpad_acpi" is used because of userspace
27issues.
28
29"tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
30long due to length limitations on some Linux kernel versions.
31
32Status
33------
34
35The features currently supported are the following (see below for
36detailed description):
37
38 - Fn key combinations
39 - Bluetooth enable and disable
40 - video output switching, expansion control
41 - ThinkLight on and off
42 - CMOS/UCMS control
43 - LED control
44 - ACPI sounds
45 - temperature sensors
46 - Experimental: embedded controller register dump
47 - LCD brightness control
48 - Volume 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
53 - Lap mode sensor
54 - Setting keyboard language
55 - WWAN Antenna type
56 - Auxmac
57 - Hardware damage detection capability
58
59A compatibility table by model and feature is maintained on the web
60site, http://ibm-acpi.sf.net/. I appreciate any success or failure
61reports, especially if they add to or correct the compatibility table.
62Please include the following information in your report:
63
64 - ThinkPad model name
65 - a copy of your ACPI tables, using the "acpidump" utility
66 - a copy of the output of dmidecode, with serial numbers
67 and UUIDs masked off
68 - which driver features work and which don't
69 - the observed behavior of non-working features
70
71Any other comments or patches are also more than welcome.
72
73
74Installation
75------------
76
77If you are compiling this driver as included in the Linux kernel
78sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
79It is located on the menu path: "Device Drivers" -> "X86 Platform
80Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
81
82
83Features
84--------
85
86The driver exports two different interfaces to userspace, which can be
87used to access the features it provides. One is a legacy procfs-based
88interface, which will be removed at some time in the future. The other
89is a new sysfs-based interface which is not complete yet.
90
91The procfs interface creates the /proc/acpi/ibm directory. There is a
92file under that directory for each feature it supports. The procfs
93interface is mostly frozen, and will change very little if at all: it
94will not be extended to add any new functionality in the driver, instead
95all new functionality will be implemented on the sysfs interface.
96
97The sysfs interface tries to blend in the generic Linux sysfs subsystems
98and classes as much as possible. Since some of these subsystems are not
99yet ready or stabilized, it is expected that this interface will change,
100and any and all userspace programs must deal with it.
101
102
103Notes about the sysfs interface
104^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
105
106Unlike what was done with the procfs interface, correctness when talking
107to the sysfs interfaces will be enforced, as will correctness in the
108thinkpad-acpi's implementation of sysfs interfaces.
109
110Also, any bugs in the thinkpad-acpi sysfs driver code or in the
111thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
112maximum correctness, even if that means changing an interface in
113non-compatible ways. As these interfaces mature both in the kernel and
114in thinkpad-acpi, such changes should become quite rare.
115
116Applications interfacing to the thinkpad-acpi sysfs interfaces must
117follow all sysfs guidelines and correctly process all errors (the sysfs
118interface makes extensive use of errors). File descriptors and open /
119close operations to the sysfs inodes must also be properly implemented.
120
121The version of thinkpad-acpi's sysfs interface is exported by the driver
122as a driver attribute (see below).
123
124Sysfs driver attributes are on the driver's sysfs attribute space,
125for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
126/sys/bus/platform/drivers/thinkpad_hwmon/
127
128Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
129space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
130
131Sysfs device attributes for the sensors and fan are on the
132thinkpad_hwmon device's sysfs attribute space, but you should locate it
133looking for a hwmon device with the name attribute of "thinkpad", or
134better yet, through libsensors. For 4.14+ sysfs attributes were moved to the
135hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or
136/sys/class/hwmon/hwmon?).
137
138Driver version
139--------------
140
141procfs: /proc/acpi/ibm/driver
142
143sysfs driver attribute: version
144
145The driver name and version. No commands can be written to this file.
146
147
148Sysfs interface version
149-----------------------
150
151sysfs driver attribute: interface_version
152
153Version of the thinkpad-acpi sysfs interface, as an unsigned long
154(output in hex format: 0xAAAABBCC), where:
155
156 AAAA
157 - major revision
158 BB
159 - minor revision
160 CC
161 - bugfix revision
162
163The sysfs interface version changelog for the driver can be found at the
164end of this document. Changes to the sysfs interface done by the kernel
165subsystems are not documented here, nor are they tracked by this
166attribute.
167
168Changes to the thinkpad-acpi sysfs interface are only considered
169non-experimental when they are submitted to Linux mainline, at which
170point the changes in this interface are documented and interface_version
171may be updated. If you are using any thinkpad-acpi features not yet
172sent to mainline for merging, you do so on your own risk: these features
173may disappear, or be implemented in a different and incompatible way by
174the time they are merged in Linux mainline.
175
176Changes that are backwards-compatible by nature (e.g. the addition of
177attributes that do not change the way the other attributes work) do not
178always warrant an update of interface_version. Therefore, one must
179expect that an attribute might not be there, and deal with it properly
180(an attribute not being there *is* a valid way to make it clear that a
181feature is not available in sysfs).
182
183
184Hot keys
185--------
186
187procfs: /proc/acpi/ibm/hotkey
188
189sysfs device attribute: hotkey_*
190
191In a ThinkPad, the ACPI HKEY handler is responsible for communicating
192some important events and also keyboard hot key presses to the operating
193system. Enabling the hotkey functionality of thinkpad-acpi signals the
194firmware that such a driver is present, and modifies how the ThinkPad
195firmware will behave in many situations.
196
197The driver enables the HKEY ("hot key") event reporting automatically
198when loaded, and disables it when it is removed.
199
200The driver will report HKEY events in the following format::
201
202 ibm/hotkey HKEY 00000080 0000xxxx
203
204Some of these events refer to hot key presses, but not all of them.
205
206The driver will generate events over the input layer for hot keys and
207radio switches, and over the ACPI netlink layer for other events. The
208input layer support accepts the standard IOCTLs to remap the keycodes
209assigned to each hot key.
210
211The hot key bit mask allows some control over which hot keys generate
212events. If a key is "masked" (bit set to 0 in the mask), the firmware
213will handle it. If it is "unmasked", it signals the firmware that
214thinkpad-acpi would prefer to handle it, if the firmware would be so
215kind to allow it (and it often doesn't!).
216
217Not all bits in the mask can be modified. Not all bits that can be
218modified do anything. Not all hot keys can be individually controlled
219by the mask. Some models do not support the mask at all. The behaviour
220of the mask is, therefore, highly dependent on the ThinkPad model.
221
222The driver will filter out any unmasked hotkeys, so even if the firmware
223doesn't allow disabling an specific hotkey, the driver will not report
224events for unmasked hotkeys.
225
226Note that unmasking some keys prevents their default behavior. For
227example, if Fn+F5 is unmasked, that key will no longer enable/disable
228Bluetooth by itself in firmware.
229
230Note also that not all Fn key combinations are supported through ACPI
231depending on the ThinkPad model and firmware version. On those
232ThinkPads, it is still possible to support some extra hotkeys by
233polling the "CMOS NVRAM" at least 10 times per second. The driver
234attempts to enables this functionality automatically when required.
235
236procfs notes
237^^^^^^^^^^^^
238
239The following commands can be written to the /proc/acpi/ibm/hotkey file::
240
241 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
242 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
243 ... any other 8-hex-digit mask ...
244 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
245
246The following commands have been deprecated and will cause the kernel
247to log a warning::
248
249 echo enable > /proc/acpi/ibm/hotkey -- does nothing
250 echo disable > /proc/acpi/ibm/hotkey -- returns an error
251
252The procfs interface does not support NVRAM polling control. So as to
253maintain maximum bug-to-bug compatibility, it does not report any masks,
254nor does it allow one to manipulate the hot key mask when the firmware
255does not support masks at all, even if NVRAM polling is in use.
256
257sysfs notes
258^^^^^^^^^^^
259
260 hotkey_bios_enabled:
261 DEPRECATED, WILL BE REMOVED SOON.
262
263 Returns 0.
264
265 hotkey_bios_mask:
266 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
267
268 Returns the hot keys mask when thinkpad-acpi was loaded.
269 Upon module unload, the hot keys mask will be restored
270 to this value. This is always 0x80c, because those are
271 the hotkeys that were supported by ancient firmware
272 without mask support.
273
274 hotkey_enable:
275 DEPRECATED, WILL BE REMOVED SOON.
276
277 0: returns -EPERM
278 1: does nothing
279
280 hotkey_mask:
281 bit mask to enable reporting (and depending on
282 the firmware, ACPI event generation) for each hot key
283 (see above). Returns the current status of the hot keys
284 mask, and allows one to modify it.
285
286 hotkey_all_mask:
287 bit mask that should enable event reporting for all
288 supported hot keys, when echoed to hotkey_mask above.
289 Unless you know which events need to be handled
290 passively (because the firmware *will* handle them
291 anyway), do *not* use hotkey_all_mask. Use
292 hotkey_recommended_mask, instead. You have been warned.
293
294 hotkey_recommended_mask:
295 bit mask that should enable event reporting for all
296 supported hot keys, except those which are always
297 handled by the firmware anyway. Echo it to
298 hotkey_mask above, to use. This is the default mask
299 used by the driver.
300
301 hotkey_source_mask:
302 bit mask that selects which hot keys will the driver
303 poll the NVRAM for. This is auto-detected by the driver
304 based on the capabilities reported by the ACPI firmware,
305 but it can be overridden at runtime.
306
307 Hot keys whose bits are set in hotkey_source_mask are
308 polled for in NVRAM, and reported as hotkey events if
309 enabled in hotkey_mask. Only a few hot keys are
310 available through CMOS NVRAM polling.
311
312 Warning: when in NVRAM mode, the volume up/down/mute
313 keys are synthesized according to changes in the mixer,
314 which uses a single volume up or volume down hotkey
315 press to unmute, as per the ThinkPad volume mixer user
316 interface. When in ACPI event mode, volume up/down/mute
317 events are reported by the firmware and can behave
318 differently (and that behaviour changes with firmware
319 version -- not just with firmware models -- as well as
320 OSI(Linux) state).
321
322 hotkey_poll_freq:
323 frequency in Hz for hot key polling. It must be between
324 0 and 25 Hz. Polling is only carried out when strictly
325 needed.
326
327 Setting hotkey_poll_freq to zero disables polling, and
328 will cause hot key presses that require NVRAM polling
329 to never be reported.
330
331 Setting hotkey_poll_freq too low may cause repeated
332 pressings of the same hot key to be misreported as a
333 single key press, or to not even be detected at all.
334 The recommended polling frequency is 10Hz.
335
336 hotkey_radio_sw:
337 If the ThinkPad has a hardware radio switch, this
338 attribute will read 0 if the switch is in the "radios
339 disabled" position, and 1 if the switch is in the
340 "radios enabled" position.
341
342 This attribute has poll()/select() support.
343
344 hotkey_tablet_mode:
345 If the ThinkPad has tablet capabilities, this attribute
346 will read 0 if the ThinkPad is in normal mode, and
347 1 if the ThinkPad is in tablet mode.
348
349 This attribute has poll()/select() support.
350
351 wakeup_reason:
352 Set to 1 if the system is waking up because the user
353 requested a bay ejection. Set to 2 if the system is
354 waking up because the user requested the system to
355 undock. Set to zero for normal wake-ups or wake-ups
356 due to unknown reasons.
357
358 This attribute has poll()/select() support.
359
360 wakeup_hotunplug_complete:
361 Set to 1 if the system was waken up because of an
362 undock or bay ejection request, and that request
363 was successfully completed. At this point, it might
364 be useful to send the system back to sleep, at the
365 user's choice. Refer to HKEY events 0x4003 and
366 0x3003, below.
367
368 This attribute has poll()/select() support.
369
370input layer notes
371^^^^^^^^^^^^^^^^^
372
373A Hot key is mapped to a single input layer EV_KEY event, possibly
374followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
375code. An EV_SYN event will always be generated to mark the end of the
376event block.
377
378Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
379used as a helper to remap keys, only. They are particularly useful when
380remapping KEY_UNKNOWN keys.
381
382The events are available in an input device, with the following id:
383
384 ============== ==============================
385 Bus BUS_HOST
386 vendor 0x1014 (PCI_VENDOR_ID_IBM) or
387 0x17aa (PCI_VENDOR_ID_LENOVO)
388 product 0x5054 ("TP")
389 version 0x4101
390 ============== ==============================
391
392The version will have its LSB incremented if the keymap changes in a
393backwards-compatible way. The MSB shall always be 0x41 for this input
394device. If the MSB is not 0x41, do not use the device as described in
395this section, as it is either something else (e.g. another input device
396exported by a thinkpad driver, such as HDAPS) or its functionality has
397been changed in a non-backwards compatible way.
398
399Adding other event types for other functionalities shall be considered a
400backwards-compatible change for this input device.
401
402Thinkpad-acpi Hot Key event map (version 0x4101):
403
404======= ======= ============== ==============================================
405ACPI Scan
406event code Key Notes
407======= ======= ============== ==============================================
4080x1001 0x00 FN+F1 -
409
4100x1002 0x01 FN+F2 IBM: battery (rare)
411 Lenovo: Screen lock
412
4130x1003 0x02 FN+F3 Many IBM models always report
414 this hot key, even with hot keys
415 disabled or with Fn+F3 masked
416 off
417 IBM: screen lock, often turns
418 off the ThinkLight as side-effect
419 Lenovo: battery
420
4210x1004 0x03 FN+F4 Sleep button (ACPI sleep button
422 semantics, i.e. sleep-to-RAM).
423 It always generates some kind
424 of event, either the hot key
425 event or an ACPI sleep button
426 event. The firmware may
427 refuse to generate further FN+F4
428 key presses until a S3 or S4 ACPI
429 sleep cycle is performed or some
430 time passes.
431
4320x1005 0x04 FN+F5 Radio. Enables/disables
433 the internal Bluetooth hardware
434 and W-WAN card if left in control
435 of the firmware. Does not affect
436 the WLAN card.
437 Should be used to turn on/off all
438 radios (Bluetooth+W-WAN+WLAN),
439 really.
440
4410x1006 0x05 FN+F6 -
442
4430x1007 0x06 FN+F7 Video output cycle.
444 Do you feel lucky today?
445
4460x1008 0x07 FN+F8 IBM: toggle screen expand
447 Lenovo: configure UltraNav,
448 or toggle screen expand.
449 On 2024 platforms replaced by
450 0x131f (see below) and on newer
451 platforms (2025 +) keycode is
452 replaced by 0x1401 (see below).
453
4540x1009 0x08 FN+F9 -
455
456... ... ... ...
457
4580x100B 0x0A FN+F11 -
459
4600x100C 0x0B FN+F12 Sleep to disk. You are always
461 supposed to handle it yourself,
462 either through the ACPI event,
463 or through a hotkey event.
464 The firmware may refuse to
465 generate further FN+F12 key
466 press events until a S3 or S4
467 ACPI sleep cycle is performed,
468 or some time passes.
469
4700x100D 0x0C FN+BACKSPACE -
4710x100E 0x0D FN+INSERT -
4720x100F 0x0E FN+DELETE -
473
4740x1010 0x0F FN+HOME Brightness up. This key is
475 always handled by the firmware
476 in IBM ThinkPads, even when
477 unmasked. Just leave it alone.
478 For Lenovo ThinkPads with a new
479 BIOS, it has to be handled either
480 by the ACPI OSI, or by userspace.
481 The driver does the right thing,
482 never mess with this.
4830x1011 0x10 FN+END Brightness down. See brightness
484 up for details.
485
4860x1012 0x11 FN+PGUP ThinkLight toggle. This key is
487 always handled by the firmware,
488 even when unmasked.
489
4900x1013 0x12 FN+PGDOWN -
491
4920x1014 0x13 FN+SPACE Zoom key
493
4940x1015 0x14 VOLUME UP Internal mixer volume up. This
495 key is always handled by the
496 firmware, even when unmasked.
497 NOTE: Lenovo seems to be changing
498 this.
4990x1016 0x15 VOLUME DOWN Internal mixer volume up. This
500 key is always handled by the
501 firmware, even when unmasked.
502 NOTE: Lenovo seems to be changing
503 this.
5040x1017 0x16 MUTE Mute internal mixer. This
505 key is always handled by the
506 firmware, even when unmasked.
507
5080x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
509
5100x1019 0x18 unknown
511
5120x131f ... FN+F8 Platform Mode change (2024 systems).
513 Implemented in driver.
514
5150x1401 ... FN+F8 Platform Mode change (2025 + systems).
516 Implemented in driver.
517... ... ...
518
5190x1020 0x1F unknown
520======= ======= ============== ==============================================
521
522The ThinkPad firmware does not allow one to differentiate when most hot
523keys are pressed or released (either that, or we don't know how to, yet).
524For these keys, the driver generates a set of events for a key press and
525immediately issues the same set of events for a key release. It is
526unknown by the driver if the ThinkPad firmware triggered these events on
527hot key press or release, but the firmware will do it for either one, not
528both.
529
530If a key is mapped to KEY_RESERVED, it generates no input events at all.
531If a key is mapped to KEY_UNKNOWN, it generates an input event that
532includes an scan code. If a key is mapped to anything else, it will
533generate input device EV_KEY events.
534
535In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
536events for switches:
537
538============== ==============================================
539SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
540SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
541============== ==============================================
542
543Non hotkey ACPI HKEY event map
544------------------------------
545
546Events that are never propagated by the driver:
547
548====== ==================================================
5490x2304 System is waking up from suspend to undock
5500x2305 System is waking up from suspend to eject bay
5510x2404 System is waking up from hibernation to undock
5520x2405 System is waking up from hibernation to eject bay
5530x5001 Lid closed
5540x5002 Lid opened
5550x5009 Tablet swivel: switched to tablet mode
5560x500A Tablet swivel: switched to normal mode
5570x5010 Brightness level changed/control event
5580x6000 KEYBOARD: Numlock key pressed
5590x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
5600x7000 Radio Switch may have changed state
561====== ==================================================
562
563
564Events that are propagated by the driver to userspace:
565
566====== =====================================================
5670x2313 ALARM: System is waking up from suspend because
568 the battery is nearly empty
5690x2413 ALARM: System is waking up from hibernation because
570 the battery is nearly empty
5710x3003 Bay ejection (see 0x2x05) complete, can sleep again
5720x3006 Bay hotplug request (hint to power up SATA link when
573 the optical drive tray is ejected)
5740x4003 Undocked (see 0x2x04), can sleep again
5750x4010 Docked into hotplug port replicator (non-ACPI dock)
5760x4011 Undocked from hotplug port replicator (non-ACPI dock)
5770x500B Tablet pen inserted into its storage bay
5780x500C Tablet pen removed from its storage bay
5790x6011 ALARM: battery is too hot
5800x6012 ALARM: battery is extremely hot
5810x6021 ALARM: a sensor is too hot
5820x6022 ALARM: a sensor is extremely hot
5830x6030 System thermal table changed
5840x6032 Thermal Control command set completion (DYTC, Windows)
5850x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
5860x60C0 X1 Yoga 2016, Tablet mode status changed
5870x60F0 Thermal Transformation changed (GMTS, Windows)
588====== =====================================================
589
590Battery nearly empty alarms are a last resort attempt to get the
591operating system to hibernate or shutdown cleanly (0x2313), or shutdown
592cleanly (0x2413) before power is lost. They must be acted upon, as the
593wake up caused by the firmware will have negated most safety nets...
594
595When any of the "too hot" alarms happen, according to Lenovo the user
596should suspend or hibernate the laptop (and in the case of battery
597alarms, unplug the AC adapter) to let it cool down. These alarms do
598signal that something is wrong, they should never happen on normal
599operating conditions.
600
601The "extremely hot" alarms are emergencies. According to Lenovo, the
602operating system is to force either an immediate suspend or hibernate
603cycle, or a system shutdown. Obviously, something is very wrong if this
604happens.
605
606
607Brightness hotkey notes
608^^^^^^^^^^^^^^^^^^^^^^^
609
610Don't mess with the brightness hotkeys in a Thinkpad. If you want
611notifications for OSD, use the sysfs backlight class event support.
612
613The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
614automatically for the cases were userspace has to do something to
615implement brightness changes. When you override these events, you will
616either fail to handle properly the ThinkPads that require explicit
617action to change backlight brightness, or the ThinkPads that require
618that no action be taken to work properly.
619
620
621Bluetooth
622---------
623
624procfs: /proc/acpi/ibm/bluetooth
625
626sysfs device attribute: bluetooth_enable (deprecated)
627
628sysfs rfkill class: switch "tpacpi_bluetooth_sw"
629
630This feature shows the presence and current state of a ThinkPad
631Bluetooth device in the internal ThinkPad CDC slot.
632
633If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
634so it is kept across reboots and power-off.
635
636Procfs notes
637^^^^^^^^^^^^
638
639If Bluetooth is installed, the following commands can be used::
640
641 echo enable > /proc/acpi/ibm/bluetooth
642 echo disable > /proc/acpi/ibm/bluetooth
643
644Sysfs notes
645^^^^^^^^^^^
646
647 If the Bluetooth CDC card is installed, it can be enabled /
648 disabled through the "bluetooth_enable" thinkpad-acpi device
649 attribute, and its current status can also be queried.
650
651 enable:
652
653 - 0: disables Bluetooth / Bluetooth is disabled
654 - 1: enables Bluetooth / Bluetooth is enabled.
655
656 Note: this interface has been superseded by the generic rfkill
657 class. It has been deprecated, and it will be removed in year
658 2010.
659
660 rfkill controller switch "tpacpi_bluetooth_sw": refer to
661 Documentation/driver-api/rfkill.rst for details.
662
663
664Video output control -- /proc/acpi/ibm/video
665--------------------------------------------
666
667This feature allows control over the devices used for video output -
668LCD, CRT or DVI (if available). The following commands are available::
669
670 echo lcd_enable > /proc/acpi/ibm/video
671 echo lcd_disable > /proc/acpi/ibm/video
672 echo crt_enable > /proc/acpi/ibm/video
673 echo crt_disable > /proc/acpi/ibm/video
674 echo dvi_enable > /proc/acpi/ibm/video
675 echo dvi_disable > /proc/acpi/ibm/video
676 echo auto_enable > /proc/acpi/ibm/video
677 echo auto_disable > /proc/acpi/ibm/video
678 echo expand_toggle > /proc/acpi/ibm/video
679 echo video_switch > /proc/acpi/ibm/video
680
681NOTE:
682 Access to this feature is restricted to processes owning the
683 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
684 enough with some versions of X.org to crash it.
685
686Each video output device can be enabled or disabled individually.
687Reading /proc/acpi/ibm/video shows the status of each device.
688
689Automatic video switching can be enabled or disabled. When automatic
690video switching is enabled, certain events (e.g. opening the lid,
691docking or undocking) cause the video output device to change
692automatically. While this can be useful, it also causes flickering
693and, on the X40, video corruption. By disabling automatic switching,
694the flickering or video corruption can be avoided.
695
696The video_switch command cycles through the available video outputs
697(it simulates the behavior of Fn-F7).
698
699Video expansion can be toggled through this feature. This controls
700whether the display is expanded to fill the entire LCD screen when a
701mode with less than full resolution is used. Note that the current
702video expansion status cannot be determined through this feature.
703
704Note that on many models (particularly those using Radeon graphics
705chips) the X driver configures the video card in a way which prevents
706Fn-F7 from working. This also disables the video output switching
707features of this driver, as it uses the same ACPI methods as
708Fn-F7. Video switching on the console should still work.
709
710UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
711
712
713ThinkLight control
714------------------
715
716procfs: /proc/acpi/ibm/light
717
718sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
719
720procfs notes
721^^^^^^^^^^^^
722
723The ThinkLight status can be read and set through the procfs interface. A
724few models which do not make the status available will show the ThinkLight
725status as "unknown". The available commands are::
726
727 echo on > /proc/acpi/ibm/light
728 echo off > /proc/acpi/ibm/light
729
730sysfs notes
731^^^^^^^^^^^
732
733The ThinkLight sysfs interface is documented by the LED class
734documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
735is "tpacpi::thinklight".
736
737Due to limitations in the sysfs LED class, if the status of the ThinkLight
738cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
739It is impossible to know if the status returned through sysfs is valid.
740
741
742CMOS/UCMS control
743-----------------
744
745procfs: /proc/acpi/ibm/cmos
746
747sysfs device attribute: cmos_command
748
749This feature is mostly used internally by the ACPI firmware to keep the legacy
750CMOS NVRAM bits in sync with the current machine state, and to record this
751state so that the ThinkPad will retain such settings across reboots.
752
753Some of these commands actually perform actions in some ThinkPad models, but
754this is expected to disappear more and more in newer models. As an example, in
755a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
756real, but commands 0 to 2 don't control the mixer anymore (they have been
757phased out) and just update the NVRAM.
758
759The range of valid cmos command numbers is 0 to 21, but not all have an
760effect and the behavior varies from model to model. Here is the behavior
761on the X40 (tpb is the ThinkPad Buttons utility):
762
763 - 0 - Related to "Volume down" key press
764 - 1 - Related to "Volume up" key press
765 - 2 - Related to "Mute on" key press
766 - 3 - Related to "Access IBM" key press
767 - 4 - Related to "LCD brightness up" key press
768 - 5 - Related to "LCD brightness down" key press
769 - 11 - Related to "toggle screen expansion" key press/function
770 - 12 - Related to "ThinkLight on"
771 - 13 - Related to "ThinkLight off"
772 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
773
774The cmos command interface is prone to firmware split-brain problems, as
775in newer ThinkPads it is just a compatibility layer. Do not use it, it is
776exported just as a debug tool.
777
778
779LED control
780-----------
781
782procfs: /proc/acpi/ibm/led
783sysfs attributes: as per LED class, see below for names
784
785Some of the LED indicators can be controlled through this feature. On
786some older ThinkPad models, it is possible to query the status of the
787LED indicators as well. Newer ThinkPads cannot query the real status
788of the LED indicators.
789
790Because misuse of the LEDs could induce an unaware user to perform
791dangerous actions (like undocking or ejecting a bay device while the
792buses are still active), or mask an important alarm (such as a nearly
793empty battery, or a broken battery), access to most LEDs is
794restricted.
795
796Unrestricted access to all LEDs requires that thinkpad-acpi be
797compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
798Distributions must never enable this option. Individual users that
799are aware of the consequences are welcome to enabling it.
800
801Audio mute and microphone mute LEDs are supported, but currently not
802visible to userspace. They are used by the snd-hda-intel audio driver.
803
804procfs notes
805^^^^^^^^^^^^
806
807The available commands are::
808
809 echo '<LED number> on' >/proc/acpi/ibm/led
810 echo '<LED number> off' >/proc/acpi/ibm/led
811 echo '<LED number> blink' >/proc/acpi/ibm/led
812
813The <LED number> range is 0 to 15. The set of LEDs that can be
814controlled varies from model to model. Here is the common ThinkPad
815mapping:
816
817 - 0 - power
818 - 1 - battery (orange)
819 - 2 - battery (green)
820 - 3 - UltraBase/dock
821 - 4 - UltraBay
822 - 5 - UltraBase battery slot
823 - 6 - (unknown)
824 - 7 - standby
825 - 8 - dock status 1
826 - 9 - dock status 2
827 - 10, 11 - (unknown)
828 - 12 - thinkvantage
829 - 13, 14, 15 - (unknown)
830
831All of the above can be turned on and off and can be made to blink.
832
833sysfs notes
834^^^^^^^^^^^
835
836The ThinkPad LED sysfs interface is described in detail by the LED class
837documentation, in Documentation/leds/leds-class.rst.
838
839The LEDs are named (in LED ID order, from 0 to 12):
840"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
841"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
842"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
843"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
844"tpacpi::thinkvantage".
845
846Due to limitations in the sysfs LED class, if the status of the LED
847indicators cannot be read due to an error, thinkpad-acpi will report it as
848a brightness of zero (same as LED off).
849
850If the thinkpad firmware doesn't support reading the current status,
851trying to read the current LED brightness will just return whatever
852brightness was last written to that attribute.
853
854These LEDs can blink using hardware acceleration. To request that a
855ThinkPad indicator LED should blink in hardware accelerated mode, use the
856"timer" trigger, and leave the delay_on and delay_off parameters set to
857zero (to request hardware acceleration autodetection).
858
859LEDs that are known not to exist in a given ThinkPad model are not
860made available through the sysfs interface. If you have a dock and you
861notice there are LEDs listed for your ThinkPad that do not exist (and
862are not in the dock), or if you notice that there are missing LEDs,
863a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
864
865
866ACPI sounds -- /proc/acpi/ibm/beep
867----------------------------------
868
869The BEEP method is used internally by the ACPI firmware to provide
870audible alerts in various situations. This feature allows the same
871sounds to be triggered manually.
872
873The commands are non-negative integer numbers::
874
875 echo <number> >/proc/acpi/ibm/beep
876
877The valid <number> range is 0 to 17. Not all numbers trigger sounds
878and the sounds vary from model to model. Here is the behavior on the
879X40:
880
881 - 0 - stop a sound in progress (but use 17 to stop 16)
882 - 2 - two beeps, pause, third beep ("low battery")
883 - 3 - single beep
884 - 4 - high, followed by low-pitched beep ("unable")
885 - 5 - single beep
886 - 6 - very high, followed by high-pitched beep ("AC/DC")
887 - 7 - high-pitched beep
888 - 9 - three short beeps
889 - 10 - very long beep
890 - 12 - low-pitched beep
891 - 15 - three high-pitched beeps repeating constantly, stop with 0
892 - 16 - one medium-pitched beep repeating constantly, stop with 17
893 - 17 - stop 16
894
895
896Temperature sensors
897-------------------
898
899procfs: /proc/acpi/ibm/thermal
900
901sysfs device attributes: (hwmon "thinkpad") temp*_input
902
903Most ThinkPads include six or more separate temperature sensors but only
904expose the CPU temperature through the standard ACPI methods. This
905feature shows readings from up to eight different sensors on older
906ThinkPads, and up to sixteen different sensors on newer ThinkPads.
907
908For example, on the X40, a typical output may be:
909
910temperatures:
911 42 42 45 41 36 -128 33 -128
912
913On the T43/p, a typical output may be:
914
915temperatures:
916 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
917
918The mapping of thermal sensors to physical locations varies depending on
919system-board model (and thus, on ThinkPad model).
920
921https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
922tries to track down these locations for various models.
923
924Most (newer?) models seem to follow this pattern:
925
926- 1: CPU
927- 2: (depends on model)
928- 3: (depends on model)
929- 4: GPU
930- 5: Main battery: main sensor
931- 6: Bay battery: main sensor
932- 7: Main battery: secondary sensor
933- 8: Bay battery: secondary sensor
934- 9-15: (depends on model)
935
936For the R51 (source: Thomas Gruber):
937
938- 2: Mini-PCI
939- 3: Internal HDD
940
941For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
942https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
943
944- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
945- 3: PCMCIA slot
946- 9: MCH (northbridge) to DRAM Bus
947- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
948 card, under touchpad
949- 11: Power regulator, underside of system board, below F2 key
950
951The A31 has a very atypical layout for the thermal sensors
952(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
953
954- 1: CPU
955- 2: Main Battery: main sensor
956- 3: Power Converter
957- 4: Bay Battery: main sensor
958- 5: MCH (northbridge)
959- 6: PCMCIA/ambient
960- 7: Main Battery: secondary sensor
961- 8: Bay Battery: secondary sensor
962
963
964Procfs notes
965^^^^^^^^^^^^
966
967 Readings from sensors that are not available return -128.
968 No commands can be written to this file.
969
970Sysfs notes
971^^^^^^^^^^^
972
973 Sensors that are not available return the ENXIO error. This
974 status may change at runtime, as there are hotplug thermal
975 sensors, like those inside the batteries and docks.
976
977 thinkpad-acpi thermal sensors are reported through the hwmon
978 subsystem, and follow all of the hwmon guidelines at
979 Documentation/hwmon.
980
981EXPERIMENTAL: Embedded controller register dump
982-----------------------------------------------
983
984This feature is not included in the thinkpad driver anymore.
985Instead the EC can be accessed through /sys/kernel/debug/ec with
986a userspace tool which can be found here:
987ftp://ftp.suse.com/pub/people/trenn/sources/ec
988
989Use it to determine the register holding the fan
990speed on some models. To do that, do the following:
991
992 - make sure the battery is fully charged
993 - make sure the fan is running
994 - use above mentioned tool to read out the EC
995
996Often fan and temperature values vary between
997readings. Since temperatures don't change vary fast, you can take
998several quick dumps to eliminate them.
999
1000You can use a similar method to figure out the meaning of other
1001embedded controller registers - e.g. make sure nothing else changes
1002except the charging or discharging battery to determine which
1003registers contain the current battery capacity, etc. If you experiment
1004with this, do send me your results (including some complete dumps with
1005a description of the conditions when they were taken.)
1006
1007
1008LCD brightness control
1009----------------------
1010
1011procfs: /proc/acpi/ibm/brightness
1012
1013sysfs backlight device "thinkpad_screen"
1014
1015This feature allows software control of the LCD brightness on ThinkPad
1016models which don't have a hardware brightness slider.
1017
1018It has some limitations: the LCD backlight cannot be actually turned
1019on or off by this interface, it just controls the backlight brightness
1020level.
1021
1022On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1023has eight brightness levels, ranging from 0 to 7. Some of the levels
1024may not be distinct. Later Lenovo models that implement the ACPI
1025display backlight brightness control methods have 16 levels, ranging
1026from 0 to 15.
1027
1028For IBM ThinkPads, there are two interfaces to the firmware for direct
1029brightness control, EC and UCMS (or CMOS). To select which one should be
1030used, use the brightness_mode module parameter: brightness_mode=1 selects
1031EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1032mode with NVRAM backing (so that brightness changes are remembered across
1033shutdown/reboot).
1034
1035The driver tries to select which interface to use from a table of
1036defaults for each ThinkPad model. If it makes a wrong choice, please
1037report this as a bug, so that we can fix it.
1038
1039Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1040
1041When display backlight brightness controls are available through the
1042standard ACPI interface, it is best to use it instead of this direct
1043ThinkPad-specific interface. The driver will disable its native
1044backlight brightness control interface if it detects that the standard
1045ACPI interface is available in the ThinkPad.
1046
1047If you want to use the thinkpad-acpi backlight brightness control
1048instead of the generic ACPI video backlight brightness control for some
1049reason, you should use the acpi_backlight=vendor kernel parameter.
1050
1051The brightness_enable module parameter can be used to control whether
1052the LCD brightness control feature will be enabled when available.
1053brightness_enable=0 forces it to be disabled. brightness_enable=1
1054forces it to be enabled when available, even if the standard ACPI
1055interface is also available.
1056
1057Procfs notes
1058^^^^^^^^^^^^
1059
1060The available commands are::
1061
1062 echo up >/proc/acpi/ibm/brightness
1063 echo down >/proc/acpi/ibm/brightness
1064 echo 'level <level>' >/proc/acpi/ibm/brightness
1065
1066Sysfs notes
1067^^^^^^^^^^^
1068
1069The interface is implemented through the backlight sysfs class, which is
1070poorly documented at this time.
1071
1072Locate the thinkpad_screen device under /sys/class/backlight, and inside
1073it there will be the following attributes:
1074
1075 max_brightness:
1076 Reads the maximum brightness the hardware can be set to.
1077 The minimum is always zero.
1078
1079 actual_brightness:
1080 Reads what brightness the screen is set to at this instant.
1081
1082 brightness:
1083 Writes request the driver to change brightness to the
1084 given value. Reads will tell you what brightness the
1085 driver is trying to set the display to when "power" is set
1086 to zero and the display has not been dimmed by a kernel
1087 power management event.
1088
1089 power:
1090 power management mode, where 0 is "display on", and 1 to 3
1091 will dim the display backlight to brightness level 0
1092 because thinkpad-acpi cannot really turn the backlight
1093 off. Kernel power management events can temporarily
1094 increase the current power management level, i.e. they can
1095 dim the display.
1096
1097
1098WARNING:
1099
1100 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1101 interface and the ACPI-based backlight level change interface
1102 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1103 at the same time. The two will interact in bad ways, do funny things,
1104 and maybe reduce the life of the backlight lamps by needlessly kicking
1105 its level up and down at every change.
1106
1107
1108Volume control (Console Audio control)
1109--------------------------------------
1110
1111procfs: /proc/acpi/ibm/volume
1112
1113ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1114
1115NOTE: by default, the volume control interface operates in read-only
1116mode, as it is supposed to be used for on-screen-display purposes.
1117The read/write mode can be enabled through the use of the
1118"volume_control=1" module parameter.
1119
1120NOTE: distros are urged to not enable volume_control by default, this
1121should be done by the local admin only. The ThinkPad UI is for the
1122console audio control to be done through the volume keys only, and for
1123the desktop environment to just provide on-screen-display feedback.
1124Software volume control should be done only in the main AC97/HDA
1125mixer.
1126
1127
1128About the ThinkPad Console Audio control
1129^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1130
1131ThinkPads have a built-in amplifier and muting circuit that drives the
1132console headphone and speakers. This circuit is after the main AC97
1133or HDA mixer in the audio path, and under exclusive control of the
1134firmware.
1135
1136ThinkPads have three special hotkeys to interact with the console
1137audio control: volume up, volume down and mute.
1138
1139It is worth noting that the normal way the mute function works (on
1140ThinkPads that do not have a "mute LED") is:
1141
11421. Press mute to mute. It will *always* mute, you can press it as
1143 many times as you want, and the sound will remain mute.
1144
11452. Press either volume key to unmute the ThinkPad (it will _not_
1146 change the volume, it will just unmute).
1147
1148This is a very superior design when compared to the cheap software-only
1149mute-toggle solution found on normal consumer laptops: you can be
1150absolutely sure the ThinkPad will not make noise if you press the mute
1151button, no matter the previous state.
1152
1153The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1154amplifiers driving the speakers and headphone output, and the firmware
1155also handles volume control for the headphone and speakers on these
1156ThinkPads without any help from the operating system (this volume
1157control stage exists after the main AC97 or HDA mixer in the audio
1158path).
1159
1160The newer Lenovo models only have firmware mute control, and depend on
1161the main HDA mixer to do volume control (which is done by the operating
1162system). In this case, the volume keys are filtered out for unmute
1163key press (there are some firmware bugs in this area) and delivered as
1164normal key presses to the operating system (thinkpad-acpi is not
1165involved).
1166
1167
1168The ThinkPad-ACPI volume control
1169^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1170
1171The preferred way to interact with the Console Audio control is the
1172ALSA interface.
1173
1174The legacy procfs interface allows one to read the current state,
1175and if volume control is enabled, accepts the following commands::
1176
1177 echo up >/proc/acpi/ibm/volume
1178 echo down >/proc/acpi/ibm/volume
1179 echo mute >/proc/acpi/ibm/volume
1180 echo unmute >/proc/acpi/ibm/volume
1181 echo 'level <level>' >/proc/acpi/ibm/volume
1182
1183The <level> number range is 0 to 14 although not all of them may be
1184distinct. To unmute the volume after the mute command, use either the
1185up or down command (the level command will not unmute the volume), or
1186the unmute command.
1187
1188You can use the volume_capabilities parameter to tell the driver
1189whether your thinkpad has volume control or mute-only control:
1190volume_capabilities=1 for mixers with mute and volume control,
1191volume_capabilities=2 for mixers with only mute control.
1192
1193If the driver misdetects the capabilities for your ThinkPad model,
1194please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1195can update the driver.
1196
1197There are two strategies for volume control. To select which one
1198should be used, use the volume_mode module parameter: volume_mode=1
1199selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1200(so that volume/mute changes are remembered across shutdown/reboot).
1201
1202The driver will operate in volume_mode=3 by default. If that does not
1203work well on your ThinkPad model, please report this to
1204ibm-acpi-devel@lists.sourceforge.net.
1205
1206The driver supports the standard ALSA module parameters. If the ALSA
1207mixer is disabled, the driver will disable all volume functionality.
1208
1209
1210Fan control and monitoring: fan speed, fan enable/disable
1211---------------------------------------------------------
1212
1213procfs: /proc/acpi/ibm/fan
1214
1215sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1216
1217sysfs hwmon driver attributes: fan_watchdog
1218
1219NOTE NOTE NOTE:
1220 fan control operations are disabled by default for
1221 safety reasons. To enable them, the module parameter "fan_control=1"
1222 must be given to thinkpad-acpi.
1223
1224This feature attempts to show the current fan speed, control mode and
1225other fan data that might be available. The speed is read directly
1226from the hardware registers of the embedded controller. This is known
1227to work on later R, T, X and Z series ThinkPads but may show a bogus
1228value on other models.
1229
1230Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1231controlled separately, it shares the main fan control.
1232
1233Fan levels
1234^^^^^^^^^^
1235
1236Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1237stops the fan. The higher the level, the higher the fan speed, although
1238adjacent levels often map to the same fan speed. 7 is the highest
1239level, where the fan reaches the maximum recommended speed.
1240
1241Level "auto" means the EC changes the fan level according to some
1242internal algorithm, usually based on readings from the thermal sensors.
1243
1244There is also a "full-speed" level, also known as "disengaged" level.
1245In this level, the EC disables the speed-locked closed-loop fan control,
1246and drives the fan as fast as it can go, which might exceed hardware
1247limits, so use this level with caution.
1248
1249The fan usually ramps up or down slowly from one speed to another, and
1250it is normal for the EC to take several seconds to react to fan
1251commands. The full-speed level may take up to two minutes to ramp up to
1252maximum speed, and in some ThinkPads, the tachometer readings go stale
1253while the EC is transitioning to the full-speed level.
1254
1255WARNING WARNING WARNING: do not leave the fan disabled unless you are
1256monitoring all of the temperature sensor readings and you are ready to
1257enable it if necessary to avoid overheating.
1258
1259An enabled fan in level "auto" may stop spinning if the EC decides the
1260ThinkPad is cool enough and doesn't need the extra airflow. This is
1261normal, and the EC will spin the fan up if the various thermal readings
1262rise too much.
1263
1264On the X40, this seems to depend on the CPU and HDD temperatures.
1265Specifically, the fan is turned on when either the CPU temperature
1266climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1267fan is turned off when the CPU temperature drops to 49 degrees and the
1268HDD temperature drops to 41 degrees. These thresholds cannot
1269currently be controlled.
1270
1271The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1272certain conditions are met. It will override any fan programming done
1273through thinkpad-acpi.
1274
1275The thinkpad-acpi kernel driver can be programmed to revert the fan
1276level to a safe setting if userspace does not issue one of the procfs
1277fan commands: "enable", "disable", "level" or "watchdog", or if there
1278are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1279set to 1, manual mode) within a configurable amount of time of up to
1280120 seconds. This functionality is called fan safety watchdog.
1281
1282Note that the watchdog timer stops after it enables the fan. It will be
1283rearmed again automatically (using the same interval) when one of the
1284above mentioned fan commands is received. The fan watchdog is,
1285therefore, not suitable to protect against fan mode changes made through
1286means other than the "enable", "disable", and "level" procfs fan
1287commands, or the hwmon fan control sysfs interface.
1288
1289Procfs notes
1290^^^^^^^^^^^^
1291
1292The fan may be enabled or disabled with the following commands::
1293
1294 echo enable >/proc/acpi/ibm/fan
1295 echo disable >/proc/acpi/ibm/fan
1296
1297Placing a fan on level 0 is the same as disabling it. Enabling a fan
1298will try to place it in a safe level if it is too slow or disabled.
1299
1300The fan level can be controlled with the command::
1301
1302 echo 'level <level>' > /proc/acpi/ibm/fan
1303
1304Where <level> is an integer from 0 to 7, or one of the words "auto" or
1305"full-speed" (without the quotes). Not all ThinkPads support the "auto"
1306and "full-speed" levels. The driver accepts "disengaged" as an alias for
1307"full-speed", and reports it as "disengaged" for backwards
1308compatibility.
1309
1310On the X31 and X40 (and ONLY on those models), the fan speed can be
1311controlled to a certain degree. Once the fan is running, it can be
1312forced to run faster or slower with the following command::
1313
1314 echo 'speed <speed>' > /proc/acpi/ibm/fan
1315
1316The sustainable range of fan speeds on the X40 appears to be from about
13173700 to about 7350. Values outside this range either do not have any
1318effect or the fan speed eventually settles somewhere in that range. The
1319fan cannot be stopped or started with this command. This functionality
1320is incomplete, and not available through the sysfs interface.
1321
1322To program the safety watchdog, use the "watchdog" command::
1323
1324 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1325
1326If you want to disable the watchdog, use 0 as the interval.
1327
1328Sysfs notes
1329^^^^^^^^^^^
1330
1331The sysfs interface follows the hwmon subsystem guidelines for the most
1332part, and the exception is the fan safety watchdog.
1333
1334Writes to any of the sysfs attributes may return the EINVAL error if
1335that operation is not supported in a given ThinkPad or if the parameter
1336is out-of-bounds, and EPERM if it is forbidden. They may also return
1337EINTR (interrupted system call), and EIO (I/O error while trying to talk
1338to the firmware).
1339
1340Features not yet implemented by the driver return ENOSYS.
1341
1342hwmon device attribute pwm1_enable:
1343 - 0: PWM offline (fan is set to full-speed mode)
1344 - 1: Manual PWM control (use pwm1 to set fan level)
1345 - 2: Hardware PWM control (EC "auto" mode)
1346 - 3: reserved (Software PWM control, not implemented yet)
1347
1348 Modes 0 and 2 are not supported by all ThinkPads, and the
1349 driver is not always able to detect this. If it does know a
1350 mode is unsupported, it will return -EINVAL.
1351
1352hwmon device attribute pwm1:
1353 Fan level, scaled from the firmware values of 0-7 to the hwmon
1354 scale of 0-255. 0 means fan stopped, 255 means highest normal
1355 speed (level 7).
1356
1357 This attribute only commands the fan if pmw1_enable is set to 1
1358 (manual PWM control).
1359
1360hwmon device attribute fan1_input:
1361 Fan tachometer reading, in RPM. May go stale on certain
1362 ThinkPads while the EC transitions the PWM to offline mode,
1363 which can take up to two minutes. May return rubbish on older
1364 ThinkPads.
1365
1366hwmon device attribute fan2_input:
1367 Fan tachometer reading, in RPM, for the secondary fan.
1368 Available only on some ThinkPads. If the secondary fan is
1369 not installed, will always read 0.
1370
1371hwmon driver attribute fan_watchdog:
1372 Fan safety watchdog timer interval, in seconds. Minimum is
1373 1 second, maximum is 120 seconds. 0 disables the watchdog.
1374
1375To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1376
1377To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1378with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1379would be the safest choice, though).
1380
1381
1382WAN
1383---
1384
1385procfs: /proc/acpi/ibm/wan
1386
1387sysfs device attribute: wwan_enable (deprecated)
1388
1389sysfs rfkill class: switch "tpacpi_wwan_sw"
1390
1391This feature shows the presence and current state of the built-in
1392Wireless WAN device.
1393
1394If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1395so it is kept across reboots and power-off.
1396
1397It was tested on a Lenovo ThinkPad X60. It should probably work on other
1398ThinkPad models which come with this module installed.
1399
1400Procfs notes
1401^^^^^^^^^^^^
1402
1403If the W-WAN card is installed, the following commands can be used::
1404
1405 echo enable > /proc/acpi/ibm/wan
1406 echo disable > /proc/acpi/ibm/wan
1407
1408Sysfs notes
1409^^^^^^^^^^^
1410
1411 If the W-WAN card is installed, it can be enabled /
1412 disabled through the "wwan_enable" thinkpad-acpi device
1413 attribute, and its current status can also be queried.
1414
1415 enable:
1416 - 0: disables WWAN card / WWAN card is disabled
1417 - 1: enables WWAN card / WWAN card is enabled.
1418
1419 Note: this interface has been superseded by the generic rfkill
1420 class. It has been deprecated, and it will be removed in year
1421 2010.
1422
1423 rfkill controller switch "tpacpi_wwan_sw": refer to
1424 Documentation/driver-api/rfkill.rst for details.
1425
1426
1427LCD Shadow control
1428------------------
1429
1430procfs: /proc/acpi/ibm/lcdshadow
1431
1432Some newer T480s and T490s ThinkPads provide a feature called
1433PrivacyGuard. By turning this feature on, the usable vertical and
1434horizontal viewing angles of the LCD can be limited (as if some privacy
1435screen was applied manually in front of the display).
1436
1437procfs notes
1438^^^^^^^^^^^^
1439
1440The available commands are::
1441
1442 echo '0' >/proc/acpi/ibm/lcdshadow
1443 echo '1' >/proc/acpi/ibm/lcdshadow
1444
1445The first command ensures the best viewing angle and the latter one turns
1446on the feature, restricting the viewing angles.
1447
1448
1449DYTC Lapmode sensor
1450-------------------
1451
1452sysfs: dytc_lapmode
1453
1454Newer thinkpads and mobile workstations have the ability to determine if
1455the device is in deskmode or lapmode. This feature is used by user space
1456to decide if WWAN transmission can be increased to maximum power and is
1457also useful for understanding the different thermal modes available as
1458they differ between desk and lap mode.
1459
1460The property is read-only. If the platform doesn't have support the sysfs
1461class is not created.
1462
1463EXPERIMENTAL: UWB
1464-----------------
1465
1466This feature is considered EXPERIMENTAL because it has not been extensively
1467tested and validated in various ThinkPad models yet. The feature may not
1468work as expected. USE WITH CAUTION! To use this feature, you need to supply
1469the experimental=1 parameter when loading the module.
1470
1471sysfs rfkill class: switch "tpacpi_uwb_sw"
1472
1473This feature exports an rfkill controller for the UWB device, if one is
1474present and enabled in the BIOS.
1475
1476Sysfs notes
1477^^^^^^^^^^^
1478
1479 rfkill controller switch "tpacpi_uwb_sw": refer to
1480 Documentation/driver-api/rfkill.rst for details.
1481
1482
1483Setting keyboard language
1484-------------------------
1485
1486sysfs: keyboard_lang
1487
1488This feature is used to set keyboard language to ECFW using ASL interface.
1489Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1490")" numeric keys, which are not displaying correctly, when keyboard language
1491is other than "english". This is because the default keyboard language in ECFW
1492is set as "english". Hence using this sysfs, user can set the correct keyboard
1493language to ECFW and then these key's will work correctly.
1494
1495Example of command to set keyboard language is mentioned below::
1496
1497 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1498
1499Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1500cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1501fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1502nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden),
1503tr(Turkey)
1504
1505WWAN Antenna type
1506-----------------
1507
1508sysfs: wwan_antenna_type
1509
1510On some newer Thinkpads we need to set SAR value based on the antenna
1511type. This interface will be used by userspace to get the antenna type
1512and set the corresponding SAR value, as is required for FCC certification.
1513
1514The available commands are::
1515
1516 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1517
1518Currently 2 antenna types are supported as mentioned below:
1519- type a
1520- type b
1521
1522The property is read-only. If the platform doesn't have support the sysfs
1523class is not created.
1524
1525doubletap_enable
1526----------------
1527
1528sysfs: doubletap_enable
1529
1530Controls whether TrackPoint doubletap events are filtered out. Doubletap is a
1531feature where quickly tapping the TrackPoint twice triggers a special function key event.
1532
1533The available commands are::
1534
1535 cat /sys/devices/platform/thinkpad_acpi/doubletap_enable
1536 echo 1 | sudo tee /sys/devices/platform/thinkpad_acpi/doubletap_enable
1537 echo 0 | sudo tee /sys/devices/platform/thinkpad_acpi/doubletap_enable
1538
1539Values:
1540
1541 * 1 - doubletap events are processed (default)
1542 * 0 - doubletap events are filtered out (ignored)
1543
1544 This setting can also be toggled via the Fn+doubletap hotkey.
1545
1546Auxmac
1547------
1548
1549sysfs: auxmac
1550
1551Some newer Thinkpads have a feature called MAC Address Pass-through. This
1552feature is implemented by the system firmware to provide a system unique MAC,
1553that can override a dock or USB ethernet dongle MAC, when connected to a
1554network. This property enables user-space to easily determine the MAC address
1555if the feature is enabled.
1556
1557The values of this auxiliary MAC are:
1558
1559 cat /sys/devices/platform/thinkpad_acpi/auxmac
1560
1561If the feature is disabled, the value will be 'disabled'.
1562
1563This property is read-only.
1564
1565Adaptive keyboard
1566-----------------
1567
1568sysfs device attribute: adaptive_kbd_mode
1569
1570This sysfs attribute controls the keyboard "face" that will be shown on the
1571Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1572and set.
1573
1574- 0 = Home mode
1575- 1 = Web-browser mode
1576- 2 = Web-conference mode
1577- 3 = Function mode
1578- 4 = Layflat mode
1579
1580For more details about which buttons will appear depending on the mode, please
1581review the laptop's user guide:
1582https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf
1583
1584Battery charge control
1585----------------------
1586
1587sysfs attributes:
1588/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1589
1590These two attributes are created for those batteries that are supported by the
1591driver. They enable the user to control the battery charge thresholds of the
1592given battery. Both values may be read and set. `charge_control_start_threshold`
1593accepts an integer between 0 and 99 (inclusive); this value represents a battery
1594percentage level, below which charging will begin. `charge_control_end_threshold`
1595accepts an integer between 1 and 100 (inclusive); this value represents a battery
1596percentage level, above which charging will stop.
1597
1598The exact semantics of the attributes may be found in
1599Documentation/ABI/testing/sysfs-class-power.
1600
1601Hardware damage detection capability
1602------------------------------------
1603
1604sysfs attributes: hwdd_status, hwdd_detail
1605
1606Thinkpads are adding the ability to detect and report hardware damage.
1607Add new sysfs interface to identify the damaged device status.
1608Initial support is available for the USB-C replaceable connector.
1609
1610The command to check device damaged status is::
1611
1612 cat /sys/devices/platform/thinkpad_acpi/hwdd_status
1613
1614This value displays status of device damaged.
1615
1616- 0 = Not Damaged
1617- 1 = Damaged
1618
1619The command to check location of damaged device is::
1620
1621 cat /sys/devices/platform/thinkpad_acpi/hwdd_detail
1622
1623This value displays location of damaged device having 1 line per damaged "item".
1624For example:
1625
1626if no damage is detected:
1627
1628- No damage detected
1629
1630if damage detected:
1631
1632- TYPE-C: Base, Right side, Center port
1633
1634The property is read-only. If feature is not supported then sysfs
1635attribute is not created.
1636
1637Multiple Commands, Module Parameters
1638------------------------------------
1639
1640Multiple commands can be written to the proc files in one shot by
1641separating them with commas, for example::
1642
1643 echo enable,0xffff > /proc/acpi/ibm/hotkey
1644 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1645
1646Commands can also be specified when loading the thinkpad-acpi module,
1647for example::
1648
1649 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1650
1651
1652Enabling debugging output
1653-------------------------
1654
1655The module takes a debug parameter which can be used to selectively
1656enable various classes of debugging output, for example::
1657
1658 modprobe thinkpad_acpi debug=0xffff
1659
1660will enable all debugging output classes. It takes a bitmask, so
1661to enable more than one output class, just add their values.
1662
1663 ============= ======================================
1664 Debug bitmask Description
1665 ============= ======================================
1666 0x8000 Disclose PID of userspace programs
1667 accessing some functions of the driver
1668 0x0001 Initialization and probing
1669 0x0002 Removal
1670 0x0004 RF Transmitter control (RFKILL)
1671 (bluetooth, WWAN, UWB...)
1672 0x0008 HKEY event interface, hotkeys
1673 0x0010 Fan control
1674 0x0020 Backlight brightness
1675 0x0040 Audio mixer/volume control
1676 ============= ======================================
1677
1678There is also a kernel build option to enable more debugging
1679information, which may be necessary to debug driver problems.
1680
1681The level of debugging information output by the driver can be changed
1682at runtime through sysfs, using the driver attribute debug_level. The
1683attribute takes the same bitmask as the debug module parameter above.
1684
1685
1686Force loading of module
1687-----------------------
1688
1689If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1690the module parameter force_load=1. Regardless of whether this works or
1691not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1692
1693
1694Sysfs interface changelog
1695^^^^^^^^^^^^^^^^^^^^^^^^^
1696
1697========= ===============================================================
16980x000100: Initial sysfs support, as a single platform driver and
1699 device.
17000x000200: Hot key support for 32 hot keys, and radio slider switch
1701 support.
17020x010000: Hot keys are now handled by default over the input
1703 layer, the radio switch generates input event EV_RADIO,
1704 and the driver enables hot key handling by default in
1705 the firmware.
1706
17070x020000: ABI fix: added a separate hwmon platform device and
1708 driver, which must be located by name (thinkpad)
1709 and the hwmon class for libsensors4 (lm-sensors 3)
1710 compatibility. Moved all hwmon attributes to this
1711 new platform device.
1712
17130x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1714 support. If you must, use it to know you should not
1715 start a userspace NVRAM poller (allows to detect when
1716 NVRAM is compiled out by the user because it is
1717 unneeded/undesired in the first place).
17180x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1719 and proper hotkey_mask semantics (version 8 of the
1720 NVRAM polling patch). Some development snapshots of
1721 0.18 had an earlier version that did strange things
1722 to hotkey_mask.
1723
17240x020200: Add poll()/select() support to the following attributes:
1725 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1726
17270x020300: hotkey enable/disable support removed, attributes
1728 hotkey_bios_enabled and hotkey_enable deprecated and
1729 marked for removal.
1730
17310x020400: Marker for 16 LEDs support. Also, LEDs that are known
1732 to not exist in a given model are not registered with
1733 the LED sysfs class anymore.
1734
17350x020500: Updated hotkey driver, hotkey_mask is always available
1736 and it is always able to disable hot keys. Very old
1737 thinkpads are properly supported. hotkey_bios_mask
1738 is deprecated and marked for removal.
1739
17400x020600: Marker for backlight change event support.
1741
17420x020700: Support for mute-only mixers.
1743 Volume control in read-only mode by default.
1744 Marker for ALSA mixer support.
1745
17460x030000: Thermal and fan sysfs attributes were moved to the hwmon
1747 device instead of being attached to the backing platform
1748 device.
1749========= ===============================================================