Loading...
Note: File does not exist in v4.10.11.
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
58A compatibility table by model and feature is maintained on the web
59site, http://ibm-acpi.sf.net/. I appreciate any success or failure
60reports, especially if they add to or correct the compatibility table.
61Please include the following information in your report:
62
63 - ThinkPad model name
64 - a copy of your ACPI tables, using the "acpidump" utility
65 - a copy of the output of dmidecode, with serial numbers
66 and UUIDs masked off
67 - which driver features work and which don't
68 - the observed behavior of non-working features
69
70Any other comments or patches are also more than welcome.
71
72
73Installation
74------------
75
76If you are compiling this driver as included in the Linux kernel
77sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
78It is located on the menu path: "Device Drivers" -> "X86 Platform
79Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
80
81
82Features
83--------
84
85The driver exports two different interfaces to userspace, which can be
86used to access the features it provides. One is a legacy procfs-based
87interface, which will be removed at some time in the future. The other
88is a new sysfs-based interface which is not complete yet.
89
90The procfs interface creates the /proc/acpi/ibm directory. There is a
91file under that directory for each feature it supports. The procfs
92interface is mostly frozen, and will change very little if at all: it
93will not be extended to add any new functionality in the driver, instead
94all new functionality will be implemented on the sysfs interface.
95
96The sysfs interface tries to blend in the generic Linux sysfs subsystems
97and classes as much as possible. Since some of these subsystems are not
98yet ready or stabilized, it is expected that this interface will change,
99and any and all userspace programs must deal with it.
100
101
102Notes about the sysfs interface
103^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
104
105Unlike what was done with the procfs interface, correctness when talking
106to the sysfs interfaces will be enforced, as will correctness in the
107thinkpad-acpi's implementation of sysfs interfaces.
108
109Also, any bugs in the thinkpad-acpi sysfs driver code or in the
110thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
111maximum correctness, even if that means changing an interface in
112non-compatible ways. As these interfaces mature both in the kernel and
113in thinkpad-acpi, such changes should become quite rare.
114
115Applications interfacing to the thinkpad-acpi sysfs interfaces must
116follow all sysfs guidelines and correctly process all errors (the sysfs
117interface makes extensive use of errors). File descriptors and open /
118close operations to the sysfs inodes must also be properly implemented.
119
120The version of thinkpad-acpi's sysfs interface is exported by the driver
121as a driver attribute (see below).
122
123Sysfs driver attributes are on the driver's sysfs attribute space,
124for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
125/sys/bus/platform/drivers/thinkpad_hwmon/
126
127Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
128space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
129
130Sysfs device attributes for the sensors and fan are on the
131thinkpad_hwmon device's sysfs attribute space, but you should locate it
132looking for a hwmon device with the name attribute of "thinkpad", or
133better yet, through libsensors. For 4.14+ sysfs attributes were moved to the
134hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or
135/sys/class/hwmon/hwmon?).
136
137Driver version
138--------------
139
140procfs: /proc/acpi/ibm/driver
141
142sysfs driver attribute: version
143
144The driver name and version. No commands can be written to this file.
145
146
147Sysfs interface version
148-----------------------
149
150sysfs driver attribute: interface_version
151
152Version of the thinkpad-acpi sysfs interface, as an unsigned long
153(output in hex format: 0xAAAABBCC), where:
154
155 AAAA
156 - major revision
157 BB
158 - minor revision
159 CC
160 - bugfix revision
161
162The sysfs interface version changelog for the driver can be found at the
163end of this document. Changes to the sysfs interface done by the kernel
164subsystems are not documented here, nor are they tracked by this
165attribute.
166
167Changes to the thinkpad-acpi sysfs interface are only considered
168non-experimental when they are submitted to Linux mainline, at which
169point the changes in this interface are documented and interface_version
170may be updated. If you are using any thinkpad-acpi features not yet
171sent to mainline for merging, you do so on your own risk: these features
172may disappear, or be implemented in a different and incompatible way by
173the time they are merged in Linux mainline.
174
175Changes that are backwards-compatible by nature (e.g. the addition of
176attributes that do not change the way the other attributes work) do not
177always warrant an update of interface_version. Therefore, one must
178expect that an attribute might not be there, and deal with it properly
179(an attribute not being there *is* a valid way to make it clear that a
180feature is not available in sysfs).
181
182
183Hot keys
184--------
185
186procfs: /proc/acpi/ibm/hotkey
187
188sysfs device attribute: hotkey_*
189
190In a ThinkPad, the ACPI HKEY handler is responsible for communicating
191some important events and also keyboard hot key presses to the operating
192system. Enabling the hotkey functionality of thinkpad-acpi signals the
193firmware that such a driver is present, and modifies how the ThinkPad
194firmware will behave in many situations.
195
196The driver enables the HKEY ("hot key") event reporting automatically
197when loaded, and disables it when it is removed.
198
199The driver will report HKEY events in the following format::
200
201 ibm/hotkey HKEY 00000080 0000xxxx
202
203Some of these events refer to hot key presses, but not all of them.
204
205The driver will generate events over the input layer for hot keys and
206radio switches, and over the ACPI netlink layer for other events. The
207input layer support accepts the standard IOCTLs to remap the keycodes
208assigned to each hot key.
209
210The hot key bit mask allows some control over which hot keys generate
211events. If a key is "masked" (bit set to 0 in the mask), the firmware
212will handle it. If it is "unmasked", it signals the firmware that
213thinkpad-acpi would prefer to handle it, if the firmware would be so
214kind to allow it (and it often doesn't!).
215
216Not all bits in the mask can be modified. Not all bits that can be
217modified do anything. Not all hot keys can be individually controlled
218by the mask. Some models do not support the mask at all. The behaviour
219of the mask is, therefore, highly dependent on the ThinkPad model.
220
221The driver will filter out any unmasked hotkeys, so even if the firmware
222doesn't allow disabling an specific hotkey, the driver will not report
223events for unmasked hotkeys.
224
225Note that unmasking some keys prevents their default behavior. For
226example, if Fn+F5 is unmasked, that key will no longer enable/disable
227Bluetooth by itself in firmware.
228
229Note also that not all Fn key combinations are supported through ACPI
230depending on the ThinkPad model and firmware version. On those
231ThinkPads, it is still possible to support some extra hotkeys by
232polling the "CMOS NVRAM" at least 10 times per second. The driver
233attempts to enables this functionality automatically when required.
234
235procfs notes
236^^^^^^^^^^^^
237
238The following commands can be written to the /proc/acpi/ibm/hotkey file::
239
240 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
241 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
242 ... any other 8-hex-digit mask ...
243 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
244
245The following commands have been deprecated and will cause the kernel
246to log a warning::
247
248 echo enable > /proc/acpi/ibm/hotkey -- does nothing
249 echo disable > /proc/acpi/ibm/hotkey -- returns an error
250
251The procfs interface does not support NVRAM polling control. So as to
252maintain maximum bug-to-bug compatibility, it does not report any masks,
253nor does it allow one to manipulate the hot key mask when the firmware
254does not support masks at all, even if NVRAM polling is in use.
255
256sysfs notes
257^^^^^^^^^^^
258
259 hotkey_bios_enabled:
260 DEPRECATED, WILL BE REMOVED SOON.
261
262 Returns 0.
263
264 hotkey_bios_mask:
265 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
266
267 Returns the hot keys mask when thinkpad-acpi was loaded.
268 Upon module unload, the hot keys mask will be restored
269 to this value. This is always 0x80c, because those are
270 the hotkeys that were supported by ancient firmware
271 without mask support.
272
273 hotkey_enable:
274 DEPRECATED, WILL BE REMOVED SOON.
275
276 0: returns -EPERM
277 1: does nothing
278
279 hotkey_mask:
280 bit mask to enable reporting (and depending on
281 the firmware, ACPI event generation) for each hot key
282 (see above). Returns the current status of the hot keys
283 mask, and allows one to modify it.
284
285 hotkey_all_mask:
286 bit mask that should enable event reporting for all
287 supported hot keys, when echoed to hotkey_mask above.
288 Unless you know which events need to be handled
289 passively (because the firmware *will* handle them
290 anyway), do *not* use hotkey_all_mask. Use
291 hotkey_recommended_mask, instead. You have been warned.
292
293 hotkey_recommended_mask:
294 bit mask that should enable event reporting for all
295 supported hot keys, except those which are always
296 handled by the firmware anyway. Echo it to
297 hotkey_mask above, to use. This is the default mask
298 used by the driver.
299
300 hotkey_source_mask:
301 bit mask that selects which hot keys will the driver
302 poll the NVRAM for. This is auto-detected by the driver
303 based on the capabilities reported by the ACPI firmware,
304 but it can be overridden at runtime.
305
306 Hot keys whose bits are set in hotkey_source_mask are
307 polled for in NVRAM, and reported as hotkey events if
308 enabled in hotkey_mask. Only a few hot keys are
309 available through CMOS NVRAM polling.
310
311 Warning: when in NVRAM mode, the volume up/down/mute
312 keys are synthesized according to changes in the mixer,
313 which uses a single volume up or volume down hotkey
314 press to unmute, as per the ThinkPad volume mixer user
315 interface. When in ACPI event mode, volume up/down/mute
316 events are reported by the firmware and can behave
317 differently (and that behaviour changes with firmware
318 version -- not just with firmware models -- as well as
319 OSI(Linux) state).
320
321 hotkey_poll_freq:
322 frequency in Hz for hot key polling. It must be between
323 0 and 25 Hz. Polling is only carried out when strictly
324 needed.
325
326 Setting hotkey_poll_freq to zero disables polling, and
327 will cause hot key presses that require NVRAM polling
328 to never be reported.
329
330 Setting hotkey_poll_freq too low may cause repeated
331 pressings of the same hot key to be misreported as a
332 single key press, or to not even be detected at all.
333 The recommended polling frequency is 10Hz.
334
335 hotkey_radio_sw:
336 If the ThinkPad has a hardware radio switch, this
337 attribute will read 0 if the switch is in the "radios
338 disabled" position, and 1 if the switch is in the
339 "radios enabled" position.
340
341 This attribute has poll()/select() support.
342
343 hotkey_tablet_mode:
344 If the ThinkPad has tablet capabilities, this attribute
345 will read 0 if the ThinkPad is in normal mode, and
346 1 if the ThinkPad is in tablet mode.
347
348 This attribute has poll()/select() support.
349
350 wakeup_reason:
351 Set to 1 if the system is waking up because the user
352 requested a bay ejection. Set to 2 if the system is
353 waking up because the user requested the system to
354 undock. Set to zero for normal wake-ups or wake-ups
355 due to unknown reasons.
356
357 This attribute has poll()/select() support.
358
359 wakeup_hotunplug_complete:
360 Set to 1 if the system was waken up because of an
361 undock or bay ejection request, and that request
362 was successfully completed. At this point, it might
363 be useful to send the system back to sleep, at the
364 user's choice. Refer to HKEY events 0x4003 and
365 0x3003, below.
366
367 This attribute has poll()/select() support.
368
369input layer notes
370^^^^^^^^^^^^^^^^^
371
372A Hot key is mapped to a single input layer EV_KEY event, possibly
373followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
374code. An EV_SYN event will always be generated to mark the end of the
375event block.
376
377Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
378used as a helper to remap keys, only. They are particularly useful when
379remapping KEY_UNKNOWN keys.
380
381The events are available in an input device, with the following id:
382
383 ============== ==============================
384 Bus BUS_HOST
385 vendor 0x1014 (PCI_VENDOR_ID_IBM) or
386 0x17aa (PCI_VENDOR_ID_LENOVO)
387 product 0x5054 ("TP")
388 version 0x4101
389 ============== ==============================
390
391The version will have its LSB incremented if the keymap changes in a
392backwards-compatible way. The MSB shall always be 0x41 for this input
393device. If the MSB is not 0x41, do not use the device as described in
394this section, as it is either something else (e.g. another input device
395exported by a thinkpad driver, such as HDAPS) or its functionality has
396been changed in a non-backwards compatible way.
397
398Adding other event types for other functionalities shall be considered a
399backwards-compatible change for this input device.
400
401Thinkpad-acpi Hot Key event map (version 0x4101):
402
403======= ======= ============== ==============================================
404ACPI Scan
405event code Key Notes
406======= ======= ============== ==============================================
4070x1001 0x00 FN+F1 -
408
4090x1002 0x01 FN+F2 IBM: battery (rare)
410 Lenovo: Screen lock
411
4120x1003 0x02 FN+F3 Many IBM models always report
413 this hot key, even with hot keys
414 disabled or with Fn+F3 masked
415 off
416 IBM: screen lock, often turns
417 off the ThinkLight as side-effect
418 Lenovo: battery
419
4200x1004 0x03 FN+F4 Sleep button (ACPI sleep button
421 semantics, i.e. sleep-to-RAM).
422 It always generates some kind
423 of event, either the hot key
424 event or an ACPI sleep button
425 event. The firmware may
426 refuse to generate further FN+F4
427 key presses until a S3 or S4 ACPI
428 sleep cycle is performed or some
429 time passes.
430
4310x1005 0x04 FN+F5 Radio. Enables/disables
432 the internal Bluetooth hardware
433 and W-WAN card if left in control
434 of the firmware. Does not affect
435 the WLAN card.
436 Should be used to turn on/off all
437 radios (Bluetooth+W-WAN+WLAN),
438 really.
439
4400x1006 0x05 FN+F6 -
441
4420x1007 0x06 FN+F7 Video output cycle.
443 Do you feel lucky today?
444
4450x1008 0x07 FN+F8 IBM: toggle screen expand
446 Lenovo: configure UltraNav,
447 or toggle screen expand.
448 On 2024 platforms replaced by
449 0x131f (see below) and on newer
450 platforms (2025 +) keycode is
451 replaced by 0x1401 (see below).
452
4530x1009 0x08 FN+F9 -
454
455... ... ... ...
456
4570x100B 0x0A FN+F11 -
458
4590x100C 0x0B FN+F12 Sleep to disk. You are always
460 supposed to handle it yourself,
461 either through the ACPI event,
462 or through a hotkey event.
463 The firmware may refuse to
464 generate further FN+F12 key
465 press events until a S3 or S4
466 ACPI sleep cycle is performed,
467 or some time passes.
468
4690x100D 0x0C FN+BACKSPACE -
4700x100E 0x0D FN+INSERT -
4710x100F 0x0E FN+DELETE -
472
4730x1010 0x0F FN+HOME Brightness up. This key is
474 always handled by the firmware
475 in IBM ThinkPads, even when
476 unmasked. Just leave it alone.
477 For Lenovo ThinkPads with a new
478 BIOS, it has to be handled either
479 by the ACPI OSI, or by userspace.
480 The driver does the right thing,
481 never mess with this.
4820x1011 0x10 FN+END Brightness down. See brightness
483 up for details.
484
4850x1012 0x11 FN+PGUP ThinkLight toggle. This key is
486 always handled by the firmware,
487 even when unmasked.
488
4890x1013 0x12 FN+PGDOWN -
490
4910x1014 0x13 FN+SPACE Zoom key
492
4930x1015 0x14 VOLUME UP Internal mixer volume up. This
494 key is always handled by the
495 firmware, even when unmasked.
496 NOTE: Lenovo seems to be changing
497 this.
4980x1016 0x15 VOLUME DOWN Internal mixer volume up. This
499 key is always handled by the
500 firmware, even when unmasked.
501 NOTE: Lenovo seems to be changing
502 this.
5030x1017 0x16 MUTE Mute internal mixer. This
504 key is always handled by the
505 firmware, even when unmasked.
506
5070x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
508
5090x1019 0x18 unknown
510
5110x131f ... FN+F8 Platform Mode change (2024 systems).
512 Implemented in driver.
513
5140x1401 ... FN+F8 Platform Mode change (2025 + systems).
515 Implemented in driver.
516... ... ...
517
5180x1020 0x1F unknown
519======= ======= ============== ==============================================
520
521The ThinkPad firmware does not allow one to differentiate when most hot
522keys are pressed or released (either that, or we don't know how to, yet).
523For these keys, the driver generates a set of events for a key press and
524immediately issues the same set of events for a key release. It is
525unknown by the driver if the ThinkPad firmware triggered these events on
526hot key press or release, but the firmware will do it for either one, not
527both.
528
529If a key is mapped to KEY_RESERVED, it generates no input events at all.
530If a key is mapped to KEY_UNKNOWN, it generates an input event that
531includes an scan code. If a key is mapped to anything else, it will
532generate input device EV_KEY events.
533
534In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
535events for switches:
536
537============== ==============================================
538SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
539SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
540============== ==============================================
541
542Non hotkey ACPI HKEY event map
543------------------------------
544
545Events that are never propagated by the driver:
546
547====== ==================================================
5480x2304 System is waking up from suspend to undock
5490x2305 System is waking up from suspend to eject bay
5500x2404 System is waking up from hibernation to undock
5510x2405 System is waking up from hibernation to eject bay
5520x5001 Lid closed
5530x5002 Lid opened
5540x5009 Tablet swivel: switched to tablet mode
5550x500A Tablet swivel: switched to normal mode
5560x5010 Brightness level changed/control event
5570x6000 KEYBOARD: Numlock key pressed
5580x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
5590x7000 Radio Switch may have changed state
560====== ==================================================
561
562
563Events that are propagated by the driver to userspace:
564
565====== =====================================================
5660x2313 ALARM: System is waking up from suspend because
567 the battery is nearly empty
5680x2413 ALARM: System is waking up from hibernation because
569 the battery is nearly empty
5700x3003 Bay ejection (see 0x2x05) complete, can sleep again
5710x3006 Bay hotplug request (hint to power up SATA link when
572 the optical drive tray is ejected)
5730x4003 Undocked (see 0x2x04), can sleep again
5740x4010 Docked into hotplug port replicator (non-ACPI dock)
5750x4011 Undocked from hotplug port replicator (non-ACPI dock)
5760x500B Tablet pen inserted into its storage bay
5770x500C Tablet pen removed from its storage bay
5780x6011 ALARM: battery is too hot
5790x6012 ALARM: battery is extremely hot
5800x6021 ALARM: a sensor is too hot
5810x6022 ALARM: a sensor is extremely hot
5820x6030 System thermal table changed
5830x6032 Thermal Control command set completion (DYTC, Windows)
5840x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
5850x60C0 X1 Yoga 2016, Tablet mode status changed
5860x60F0 Thermal Transformation changed (GMTS, Windows)
587====== =====================================================
588
589Battery nearly empty alarms are a last resort attempt to get the
590operating system to hibernate or shutdown cleanly (0x2313), or shutdown
591cleanly (0x2413) before power is lost. They must be acted upon, as the
592wake up caused by the firmware will have negated most safety nets...
593
594When any of the "too hot" alarms happen, according to Lenovo the user
595should suspend or hibernate the laptop (and in the case of battery
596alarms, unplug the AC adapter) to let it cool down. These alarms do
597signal that something is wrong, they should never happen on normal
598operating conditions.
599
600The "extremely hot" alarms are emergencies. According to Lenovo, the
601operating system is to force either an immediate suspend or hibernate
602cycle, or a system shutdown. Obviously, something is very wrong if this
603happens.
604
605
606Brightness hotkey notes
607^^^^^^^^^^^^^^^^^^^^^^^
608
609Don't mess with the brightness hotkeys in a Thinkpad. If you want
610notifications for OSD, use the sysfs backlight class event support.
611
612The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
613automatically for the cases were userspace has to do something to
614implement brightness changes. When you override these events, you will
615either fail to handle properly the ThinkPads that require explicit
616action to change backlight brightness, or the ThinkPads that require
617that no action be taken to work properly.
618
619
620Bluetooth
621---------
622
623procfs: /proc/acpi/ibm/bluetooth
624
625sysfs device attribute: bluetooth_enable (deprecated)
626
627sysfs rfkill class: switch "tpacpi_bluetooth_sw"
628
629This feature shows the presence and current state of a ThinkPad
630Bluetooth device in the internal ThinkPad CDC slot.
631
632If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
633so it is kept across reboots and power-off.
634
635Procfs notes
636^^^^^^^^^^^^
637
638If Bluetooth is installed, the following commands can be used::
639
640 echo enable > /proc/acpi/ibm/bluetooth
641 echo disable > /proc/acpi/ibm/bluetooth
642
643Sysfs notes
644^^^^^^^^^^^
645
646 If the Bluetooth CDC card is installed, it can be enabled /
647 disabled through the "bluetooth_enable" thinkpad-acpi device
648 attribute, and its current status can also be queried.
649
650 enable:
651
652 - 0: disables Bluetooth / Bluetooth is disabled
653 - 1: enables Bluetooth / Bluetooth is enabled.
654
655 Note: this interface has been superseded by the generic rfkill
656 class. It has been deprecated, and it will be removed in year
657 2010.
658
659 rfkill controller switch "tpacpi_bluetooth_sw": refer to
660 Documentation/driver-api/rfkill.rst for details.
661
662
663Video output control -- /proc/acpi/ibm/video
664--------------------------------------------
665
666This feature allows control over the devices used for video output -
667LCD, CRT or DVI (if available). The following commands are available::
668
669 echo lcd_enable > /proc/acpi/ibm/video
670 echo lcd_disable > /proc/acpi/ibm/video
671 echo crt_enable > /proc/acpi/ibm/video
672 echo crt_disable > /proc/acpi/ibm/video
673 echo dvi_enable > /proc/acpi/ibm/video
674 echo dvi_disable > /proc/acpi/ibm/video
675 echo auto_enable > /proc/acpi/ibm/video
676 echo auto_disable > /proc/acpi/ibm/video
677 echo expand_toggle > /proc/acpi/ibm/video
678 echo video_switch > /proc/acpi/ibm/video
679
680NOTE:
681 Access to this feature is restricted to processes owning the
682 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
683 enough with some versions of X.org to crash it.
684
685Each video output device can be enabled or disabled individually.
686Reading /proc/acpi/ibm/video shows the status of each device.
687
688Automatic video switching can be enabled or disabled. When automatic
689video switching is enabled, certain events (e.g. opening the lid,
690docking or undocking) cause the video output device to change
691automatically. While this can be useful, it also causes flickering
692and, on the X40, video corruption. By disabling automatic switching,
693the flickering or video corruption can be avoided.
694
695The video_switch command cycles through the available video outputs
696(it simulates the behavior of Fn-F7).
697
698Video expansion can be toggled through this feature. This controls
699whether the display is expanded to fill the entire LCD screen when a
700mode with less than full resolution is used. Note that the current
701video expansion status cannot be determined through this feature.
702
703Note that on many models (particularly those using Radeon graphics
704chips) the X driver configures the video card in a way which prevents
705Fn-F7 from working. This also disables the video output switching
706features of this driver, as it uses the same ACPI methods as
707Fn-F7. Video switching on the console should still work.
708
709UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
710
711
712ThinkLight control
713------------------
714
715procfs: /proc/acpi/ibm/light
716
717sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
718
719procfs notes
720^^^^^^^^^^^^
721
722The ThinkLight status can be read and set through the procfs interface. A
723few models which do not make the status available will show the ThinkLight
724status as "unknown". The available commands are::
725
726 echo on > /proc/acpi/ibm/light
727 echo off > /proc/acpi/ibm/light
728
729sysfs notes
730^^^^^^^^^^^
731
732The ThinkLight sysfs interface is documented by the LED class
733documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
734is "tpacpi::thinklight".
735
736Due to limitations in the sysfs LED class, if the status of the ThinkLight
737cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
738It is impossible to know if the status returned through sysfs is valid.
739
740
741CMOS/UCMS control
742-----------------
743
744procfs: /proc/acpi/ibm/cmos
745
746sysfs device attribute: cmos_command
747
748This feature is mostly used internally by the ACPI firmware to keep the legacy
749CMOS NVRAM bits in sync with the current machine state, and to record this
750state so that the ThinkPad will retain such settings across reboots.
751
752Some of these commands actually perform actions in some ThinkPad models, but
753this is expected to disappear more and more in newer models. As an example, in
754a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
755real, but commands 0 to 2 don't control the mixer anymore (they have been
756phased out) and just update the NVRAM.
757
758The range of valid cmos command numbers is 0 to 21, but not all have an
759effect and the behavior varies from model to model. Here is the behavior
760on the X40 (tpb is the ThinkPad Buttons utility):
761
762 - 0 - Related to "Volume down" key press
763 - 1 - Related to "Volume up" key press
764 - 2 - Related to "Mute on" key press
765 - 3 - Related to "Access IBM" key press
766 - 4 - Related to "LCD brightness up" key press
767 - 5 - Related to "LCD brightness down" key press
768 - 11 - Related to "toggle screen expansion" key press/function
769 - 12 - Related to "ThinkLight on"
770 - 13 - Related to "ThinkLight off"
771 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
772
773The cmos command interface is prone to firmware split-brain problems, as
774in newer ThinkPads it is just a compatibility layer. Do not use it, it is
775exported just as a debug tool.
776
777
778LED control
779-----------
780
781procfs: /proc/acpi/ibm/led
782sysfs attributes: as per LED class, see below for names
783
784Some of the LED indicators can be controlled through this feature. On
785some older ThinkPad models, it is possible to query the status of the
786LED indicators as well. Newer ThinkPads cannot query the real status
787of the LED indicators.
788
789Because misuse of the LEDs could induce an unaware user to perform
790dangerous actions (like undocking or ejecting a bay device while the
791buses are still active), or mask an important alarm (such as a nearly
792empty battery, or a broken battery), access to most LEDs is
793restricted.
794
795Unrestricted access to all LEDs requires that thinkpad-acpi be
796compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
797Distributions must never enable this option. Individual users that
798are aware of the consequences are welcome to enabling it.
799
800Audio mute and microphone mute LEDs are supported, but currently not
801visible to userspace. They are used by the snd-hda-intel audio driver.
802
803procfs notes
804^^^^^^^^^^^^
805
806The available commands are::
807
808 echo '<LED number> on' >/proc/acpi/ibm/led
809 echo '<LED number> off' >/proc/acpi/ibm/led
810 echo '<LED number> blink' >/proc/acpi/ibm/led
811
812The <LED number> range is 0 to 15. The set of LEDs that can be
813controlled varies from model to model. Here is the common ThinkPad
814mapping:
815
816 - 0 - power
817 - 1 - battery (orange)
818 - 2 - battery (green)
819 - 3 - UltraBase/dock
820 - 4 - UltraBay
821 - 5 - UltraBase battery slot
822 - 6 - (unknown)
823 - 7 - standby
824 - 8 - dock status 1
825 - 9 - dock status 2
826 - 10, 11 - (unknown)
827 - 12 - thinkvantage
828 - 13, 14, 15 - (unknown)
829
830All of the above can be turned on and off and can be made to blink.
831
832sysfs notes
833^^^^^^^^^^^
834
835The ThinkPad LED sysfs interface is described in detail by the LED class
836documentation, in Documentation/leds/leds-class.rst.
837
838The LEDs are named (in LED ID order, from 0 to 12):
839"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
840"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
841"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
842"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
843"tpacpi::thinkvantage".
844
845Due to limitations in the sysfs LED class, if the status of the LED
846indicators cannot be read due to an error, thinkpad-acpi will report it as
847a brightness of zero (same as LED off).
848
849If the thinkpad firmware doesn't support reading the current status,
850trying to read the current LED brightness will just return whatever
851brightness was last written to that attribute.
852
853These LEDs can blink using hardware acceleration. To request that a
854ThinkPad indicator LED should blink in hardware accelerated mode, use the
855"timer" trigger, and leave the delay_on and delay_off parameters set to
856zero (to request hardware acceleration autodetection).
857
858LEDs that are known not to exist in a given ThinkPad model are not
859made available through the sysfs interface. If you have a dock and you
860notice there are LEDs listed for your ThinkPad that do not exist (and
861are not in the dock), or if you notice that there are missing LEDs,
862a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
863
864
865ACPI sounds -- /proc/acpi/ibm/beep
866----------------------------------
867
868The BEEP method is used internally by the ACPI firmware to provide
869audible alerts in various situations. This feature allows the same
870sounds to be triggered manually.
871
872The commands are non-negative integer numbers::
873
874 echo <number> >/proc/acpi/ibm/beep
875
876The valid <number> range is 0 to 17. Not all numbers trigger sounds
877and the sounds vary from model to model. Here is the behavior on the
878X40:
879
880 - 0 - stop a sound in progress (but use 17 to stop 16)
881 - 2 - two beeps, pause, third beep ("low battery")
882 - 3 - single beep
883 - 4 - high, followed by low-pitched beep ("unable")
884 - 5 - single beep
885 - 6 - very high, followed by high-pitched beep ("AC/DC")
886 - 7 - high-pitched beep
887 - 9 - three short beeps
888 - 10 - very long beep
889 - 12 - low-pitched beep
890 - 15 - three high-pitched beeps repeating constantly, stop with 0
891 - 16 - one medium-pitched beep repeating constantly, stop with 17
892 - 17 - stop 16
893
894
895Temperature sensors
896-------------------
897
898procfs: /proc/acpi/ibm/thermal
899
900sysfs device attributes: (hwmon "thinkpad") temp*_input
901
902Most ThinkPads include six or more separate temperature sensors but only
903expose the CPU temperature through the standard ACPI methods. This
904feature shows readings from up to eight different sensors on older
905ThinkPads, and up to sixteen different sensors on newer ThinkPads.
906
907For example, on the X40, a typical output may be:
908
909temperatures:
910 42 42 45 41 36 -128 33 -128
911
912On the T43/p, a typical output may be:
913
914temperatures:
915 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
916
917The mapping of thermal sensors to physical locations varies depending on
918system-board model (and thus, on ThinkPad model).
919
920https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
921tries to track down these locations for various models.
922
923Most (newer?) models seem to follow this pattern:
924
925- 1: CPU
926- 2: (depends on model)
927- 3: (depends on model)
928- 4: GPU
929- 5: Main battery: main sensor
930- 6: Bay battery: main sensor
931- 7: Main battery: secondary sensor
932- 8: Bay battery: secondary sensor
933- 9-15: (depends on model)
934
935For the R51 (source: Thomas Gruber):
936
937- 2: Mini-PCI
938- 3: Internal HDD
939
940For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
941https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
942
943- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
944- 3: PCMCIA slot
945- 9: MCH (northbridge) to DRAM Bus
946- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
947 card, under touchpad
948- 11: Power regulator, underside of system board, below F2 key
949
950The A31 has a very atypical layout for the thermal sensors
951(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
952
953- 1: CPU
954- 2: Main Battery: main sensor
955- 3: Power Converter
956- 4: Bay Battery: main sensor
957- 5: MCH (northbridge)
958- 6: PCMCIA/ambient
959- 7: Main Battery: secondary sensor
960- 8: Bay Battery: secondary sensor
961
962
963Procfs notes
964^^^^^^^^^^^^
965
966 Readings from sensors that are not available return -128.
967 No commands can be written to this file.
968
969Sysfs notes
970^^^^^^^^^^^
971
972 Sensors that are not available return the ENXIO error. This
973 status may change at runtime, as there are hotplug thermal
974 sensors, like those inside the batteries and docks.
975
976 thinkpad-acpi thermal sensors are reported through the hwmon
977 subsystem, and follow all of the hwmon guidelines at
978 Documentation/hwmon.
979
980EXPERIMENTAL: Embedded controller register dump
981-----------------------------------------------
982
983This feature is not included in the thinkpad driver anymore.
984Instead the EC can be accessed through /sys/kernel/debug/ec with
985a userspace tool which can be found here:
986ftp://ftp.suse.com/pub/people/trenn/sources/ec
987
988Use it to determine the register holding the fan
989speed on some models. To do that, do the following:
990
991 - make sure the battery is fully charged
992 - make sure the fan is running
993 - use above mentioned tool to read out the EC
994
995Often fan and temperature values vary between
996readings. Since temperatures don't change vary fast, you can take
997several quick dumps to eliminate them.
998
999You can use a similar method to figure out the meaning of other
1000embedded controller registers - e.g. make sure nothing else changes
1001except the charging or discharging battery to determine which
1002registers contain the current battery capacity, etc. If you experiment
1003with this, do send me your results (including some complete dumps with
1004a description of the conditions when they were taken.)
1005
1006
1007LCD brightness control
1008----------------------
1009
1010procfs: /proc/acpi/ibm/brightness
1011
1012sysfs backlight device "thinkpad_screen"
1013
1014This feature allows software control of the LCD brightness on ThinkPad
1015models which don't have a hardware brightness slider.
1016
1017It has some limitations: the LCD backlight cannot be actually turned
1018on or off by this interface, it just controls the backlight brightness
1019level.
1020
1021On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1022has eight brightness levels, ranging from 0 to 7. Some of the levels
1023may not be distinct. Later Lenovo models that implement the ACPI
1024display backlight brightness control methods have 16 levels, ranging
1025from 0 to 15.
1026
1027For IBM ThinkPads, there are two interfaces to the firmware for direct
1028brightness control, EC and UCMS (or CMOS). To select which one should be
1029used, use the brightness_mode module parameter: brightness_mode=1 selects
1030EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1031mode with NVRAM backing (so that brightness changes are remembered across
1032shutdown/reboot).
1033
1034The driver tries to select which interface to use from a table of
1035defaults for each ThinkPad model. If it makes a wrong choice, please
1036report this as a bug, so that we can fix it.
1037
1038Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1039
1040When display backlight brightness controls are available through the
1041standard ACPI interface, it is best to use it instead of this direct
1042ThinkPad-specific interface. The driver will disable its native
1043backlight brightness control interface if it detects that the standard
1044ACPI interface is available in the ThinkPad.
1045
1046If you want to use the thinkpad-acpi backlight brightness control
1047instead of the generic ACPI video backlight brightness control for some
1048reason, you should use the acpi_backlight=vendor kernel parameter.
1049
1050The brightness_enable module parameter can be used to control whether
1051the LCD brightness control feature will be enabled when available.
1052brightness_enable=0 forces it to be disabled. brightness_enable=1
1053forces it to be enabled when available, even if the standard ACPI
1054interface is also available.
1055
1056Procfs notes
1057^^^^^^^^^^^^
1058
1059The available commands are::
1060
1061 echo up >/proc/acpi/ibm/brightness
1062 echo down >/proc/acpi/ibm/brightness
1063 echo 'level <level>' >/proc/acpi/ibm/brightness
1064
1065Sysfs notes
1066^^^^^^^^^^^
1067
1068The interface is implemented through the backlight sysfs class, which is
1069poorly documented at this time.
1070
1071Locate the thinkpad_screen device under /sys/class/backlight, and inside
1072it there will be the following attributes:
1073
1074 max_brightness:
1075 Reads the maximum brightness the hardware can be set to.
1076 The minimum is always zero.
1077
1078 actual_brightness:
1079 Reads what brightness the screen is set to at this instant.
1080
1081 brightness:
1082 Writes request the driver to change brightness to the
1083 given value. Reads will tell you what brightness the
1084 driver is trying to set the display to when "power" is set
1085 to zero and the display has not been dimmed by a kernel
1086 power management event.
1087
1088 power:
1089 power management mode, where 0 is "display on", and 1 to 3
1090 will dim the display backlight to brightness level 0
1091 because thinkpad-acpi cannot really turn the backlight
1092 off. Kernel power management events can temporarily
1093 increase the current power management level, i.e. they can
1094 dim the display.
1095
1096
1097WARNING:
1098
1099 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1100 interface and the ACPI-based backlight level change interface
1101 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1102 at the same time. The two will interact in bad ways, do funny things,
1103 and maybe reduce the life of the backlight lamps by needlessly kicking
1104 its level up and down at every change.
1105
1106
1107Volume control (Console Audio control)
1108--------------------------------------
1109
1110procfs: /proc/acpi/ibm/volume
1111
1112ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1113
1114NOTE: by default, the volume control interface operates in read-only
1115mode, as it is supposed to be used for on-screen-display purposes.
1116The read/write mode can be enabled through the use of the
1117"volume_control=1" module parameter.
1118
1119NOTE: distros are urged to not enable volume_control by default, this
1120should be done by the local admin only. The ThinkPad UI is for the
1121console audio control to be done through the volume keys only, and for
1122the desktop environment to just provide on-screen-display feedback.
1123Software volume control should be done only in the main AC97/HDA
1124mixer.
1125
1126
1127About the ThinkPad Console Audio control
1128^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1129
1130ThinkPads have a built-in amplifier and muting circuit that drives the
1131console headphone and speakers. This circuit is after the main AC97
1132or HDA mixer in the audio path, and under exclusive control of the
1133firmware.
1134
1135ThinkPads have three special hotkeys to interact with the console
1136audio control: volume up, volume down and mute.
1137
1138It is worth noting that the normal way the mute function works (on
1139ThinkPads that do not have a "mute LED") is:
1140
11411. Press mute to mute. It will *always* mute, you can press it as
1142 many times as you want, and the sound will remain mute.
1143
11442. Press either volume key to unmute the ThinkPad (it will _not_
1145 change the volume, it will just unmute).
1146
1147This is a very superior design when compared to the cheap software-only
1148mute-toggle solution found on normal consumer laptops: you can be
1149absolutely sure the ThinkPad will not make noise if you press the mute
1150button, no matter the previous state.
1151
1152The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1153amplifiers driving the speakers and headphone output, and the firmware
1154also handles volume control for the headphone and speakers on these
1155ThinkPads without any help from the operating system (this volume
1156control stage exists after the main AC97 or HDA mixer in the audio
1157path).
1158
1159The newer Lenovo models only have firmware mute control, and depend on
1160the main HDA mixer to do volume control (which is done by the operating
1161system). In this case, the volume keys are filtered out for unmute
1162key press (there are some firmware bugs in this area) and delivered as
1163normal key presses to the operating system (thinkpad-acpi is not
1164involved).
1165
1166
1167The ThinkPad-ACPI volume control
1168^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1169
1170The preferred way to interact with the Console Audio control is the
1171ALSA interface.
1172
1173The legacy procfs interface allows one to read the current state,
1174and if volume control is enabled, accepts the following commands::
1175
1176 echo up >/proc/acpi/ibm/volume
1177 echo down >/proc/acpi/ibm/volume
1178 echo mute >/proc/acpi/ibm/volume
1179 echo unmute >/proc/acpi/ibm/volume
1180 echo 'level <level>' >/proc/acpi/ibm/volume
1181
1182The <level> number range is 0 to 14 although not all of them may be
1183distinct. To unmute the volume after the mute command, use either the
1184up or down command (the level command will not unmute the volume), or
1185the unmute command.
1186
1187You can use the volume_capabilities parameter to tell the driver
1188whether your thinkpad has volume control or mute-only control:
1189volume_capabilities=1 for mixers with mute and volume control,
1190volume_capabilities=2 for mixers with only mute control.
1191
1192If the driver misdetects the capabilities for your ThinkPad model,
1193please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1194can update the driver.
1195
1196There are two strategies for volume control. To select which one
1197should be used, use the volume_mode module parameter: volume_mode=1
1198selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1199(so that volume/mute changes are remembered across shutdown/reboot).
1200
1201The driver will operate in volume_mode=3 by default. If that does not
1202work well on your ThinkPad model, please report this to
1203ibm-acpi-devel@lists.sourceforge.net.
1204
1205The driver supports the standard ALSA module parameters. If the ALSA
1206mixer is disabled, the driver will disable all volume functionality.
1207
1208
1209Fan control and monitoring: fan speed, fan enable/disable
1210---------------------------------------------------------
1211
1212procfs: /proc/acpi/ibm/fan
1213
1214sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1215
1216sysfs hwmon driver attributes: fan_watchdog
1217
1218NOTE NOTE NOTE:
1219 fan control operations are disabled by default for
1220 safety reasons. To enable them, the module parameter "fan_control=1"
1221 must be given to thinkpad-acpi.
1222
1223This feature attempts to show the current fan speed, control mode and
1224other fan data that might be available. The speed is read directly
1225from the hardware registers of the embedded controller. This is known
1226to work on later R, T, X and Z series ThinkPads but may show a bogus
1227value on other models.
1228
1229Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1230controlled separately, it shares the main fan control.
1231
1232Fan levels
1233^^^^^^^^^^
1234
1235Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1236stops the fan. The higher the level, the higher the fan speed, although
1237adjacent levels often map to the same fan speed. 7 is the highest
1238level, where the fan reaches the maximum recommended speed.
1239
1240Level "auto" means the EC changes the fan level according to some
1241internal algorithm, usually based on readings from the thermal sensors.
1242
1243There is also a "full-speed" level, also known as "disengaged" level.
1244In this level, the EC disables the speed-locked closed-loop fan control,
1245and drives the fan as fast as it can go, which might exceed hardware
1246limits, so use this level with caution.
1247
1248The fan usually ramps up or down slowly from one speed to another, and
1249it is normal for the EC to take several seconds to react to fan
1250commands. The full-speed level may take up to two minutes to ramp up to
1251maximum speed, and in some ThinkPads, the tachometer readings go stale
1252while the EC is transitioning to the full-speed level.
1253
1254WARNING WARNING WARNING: do not leave the fan disabled unless you are
1255monitoring all of the temperature sensor readings and you are ready to
1256enable it if necessary to avoid overheating.
1257
1258An enabled fan in level "auto" may stop spinning if the EC decides the
1259ThinkPad is cool enough and doesn't need the extra airflow. This is
1260normal, and the EC will spin the fan up if the various thermal readings
1261rise too much.
1262
1263On the X40, this seems to depend on the CPU and HDD temperatures.
1264Specifically, the fan is turned on when either the CPU temperature
1265climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1266fan is turned off when the CPU temperature drops to 49 degrees and the
1267HDD temperature drops to 41 degrees. These thresholds cannot
1268currently be controlled.
1269
1270The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1271certain conditions are met. It will override any fan programming done
1272through thinkpad-acpi.
1273
1274The thinkpad-acpi kernel driver can be programmed to revert the fan
1275level to a safe setting if userspace does not issue one of the procfs
1276fan commands: "enable", "disable", "level" or "watchdog", or if there
1277are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1278set to 1, manual mode) within a configurable amount of time of up to
1279120 seconds. This functionality is called fan safety watchdog.
1280
1281Note that the watchdog timer stops after it enables the fan. It will be
1282rearmed again automatically (using the same interval) when one of the
1283above mentioned fan commands is received. The fan watchdog is,
1284therefore, not suitable to protect against fan mode changes made through
1285means other than the "enable", "disable", and "level" procfs fan
1286commands, or the hwmon fan control sysfs interface.
1287
1288Procfs notes
1289^^^^^^^^^^^^
1290
1291The fan may be enabled or disabled with the following commands::
1292
1293 echo enable >/proc/acpi/ibm/fan
1294 echo disable >/proc/acpi/ibm/fan
1295
1296Placing a fan on level 0 is the same as disabling it. Enabling a fan
1297will try to place it in a safe level if it is too slow or disabled.
1298
1299The fan level can be controlled with the command::
1300
1301 echo 'level <level>' > /proc/acpi/ibm/fan
1302
1303Where <level> is an integer from 0 to 7, or one of the words "auto" or
1304"full-speed" (without the quotes). Not all ThinkPads support the "auto"
1305and "full-speed" levels. The driver accepts "disengaged" as an alias for
1306"full-speed", and reports it as "disengaged" for backwards
1307compatibility.
1308
1309On the X31 and X40 (and ONLY on those models), the fan speed can be
1310controlled to a certain degree. Once the fan is running, it can be
1311forced to run faster or slower with the following command::
1312
1313 echo 'speed <speed>' > /proc/acpi/ibm/fan
1314
1315The sustainable range of fan speeds on the X40 appears to be from about
13163700 to about 7350. Values outside this range either do not have any
1317effect or the fan speed eventually settles somewhere in that range. The
1318fan cannot be stopped or started with this command. This functionality
1319is incomplete, and not available through the sysfs interface.
1320
1321To program the safety watchdog, use the "watchdog" command::
1322
1323 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1324
1325If you want to disable the watchdog, use 0 as the interval.
1326
1327Sysfs notes
1328^^^^^^^^^^^
1329
1330The sysfs interface follows the hwmon subsystem guidelines for the most
1331part, and the exception is the fan safety watchdog.
1332
1333Writes to any of the sysfs attributes may return the EINVAL error if
1334that operation is not supported in a given ThinkPad or if the parameter
1335is out-of-bounds, and EPERM if it is forbidden. They may also return
1336EINTR (interrupted system call), and EIO (I/O error while trying to talk
1337to the firmware).
1338
1339Features not yet implemented by the driver return ENOSYS.
1340
1341hwmon device attribute pwm1_enable:
1342 - 0: PWM offline (fan is set to full-speed mode)
1343 - 1: Manual PWM control (use pwm1 to set fan level)
1344 - 2: Hardware PWM control (EC "auto" mode)
1345 - 3: reserved (Software PWM control, not implemented yet)
1346
1347 Modes 0 and 2 are not supported by all ThinkPads, and the
1348 driver is not always able to detect this. If it does know a
1349 mode is unsupported, it will return -EINVAL.
1350
1351hwmon device attribute pwm1:
1352 Fan level, scaled from the firmware values of 0-7 to the hwmon
1353 scale of 0-255. 0 means fan stopped, 255 means highest normal
1354 speed (level 7).
1355
1356 This attribute only commands the fan if pmw1_enable is set to 1
1357 (manual PWM control).
1358
1359hwmon device attribute fan1_input:
1360 Fan tachometer reading, in RPM. May go stale on certain
1361 ThinkPads while the EC transitions the PWM to offline mode,
1362 which can take up to two minutes. May return rubbish on older
1363 ThinkPads.
1364
1365hwmon device attribute fan2_input:
1366 Fan tachometer reading, in RPM, for the secondary fan.
1367 Available only on some ThinkPads. If the secondary fan is
1368 not installed, will always read 0.
1369
1370hwmon driver attribute fan_watchdog:
1371 Fan safety watchdog timer interval, in seconds. Minimum is
1372 1 second, maximum is 120 seconds. 0 disables the watchdog.
1373
1374To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1375
1376To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1377with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1378would be the safest choice, though).
1379
1380
1381WAN
1382---
1383
1384procfs: /proc/acpi/ibm/wan
1385
1386sysfs device attribute: wwan_enable (deprecated)
1387
1388sysfs rfkill class: switch "tpacpi_wwan_sw"
1389
1390This feature shows the presence and current state of the built-in
1391Wireless WAN device.
1392
1393If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1394so it is kept across reboots and power-off.
1395
1396It was tested on a Lenovo ThinkPad X60. It should probably work on other
1397ThinkPad models which come with this module installed.
1398
1399Procfs notes
1400^^^^^^^^^^^^
1401
1402If the W-WAN card is installed, the following commands can be used::
1403
1404 echo enable > /proc/acpi/ibm/wan
1405 echo disable > /proc/acpi/ibm/wan
1406
1407Sysfs notes
1408^^^^^^^^^^^
1409
1410 If the W-WAN card is installed, it can be enabled /
1411 disabled through the "wwan_enable" thinkpad-acpi device
1412 attribute, and its current status can also be queried.
1413
1414 enable:
1415 - 0: disables WWAN card / WWAN card is disabled
1416 - 1: enables WWAN card / WWAN card is enabled.
1417
1418 Note: this interface has been superseded by the generic rfkill
1419 class. It has been deprecated, and it will be removed in year
1420 2010.
1421
1422 rfkill controller switch "tpacpi_wwan_sw": refer to
1423 Documentation/driver-api/rfkill.rst for details.
1424
1425
1426LCD Shadow control
1427------------------
1428
1429procfs: /proc/acpi/ibm/lcdshadow
1430
1431Some newer T480s and T490s ThinkPads provide a feature called
1432PrivacyGuard. By turning this feature on, the usable vertical and
1433horizontal viewing angles of the LCD can be limited (as if some privacy
1434screen was applied manually in front of the display).
1435
1436procfs notes
1437^^^^^^^^^^^^
1438
1439The available commands are::
1440
1441 echo '0' >/proc/acpi/ibm/lcdshadow
1442 echo '1' >/proc/acpi/ibm/lcdshadow
1443
1444The first command ensures the best viewing angle and the latter one turns
1445on the feature, restricting the viewing angles.
1446
1447
1448DYTC Lapmode sensor
1449-------------------
1450
1451sysfs: dytc_lapmode
1452
1453Newer thinkpads and mobile workstations have the ability to determine if
1454the device is in deskmode or lapmode. This feature is used by user space
1455to decide if WWAN transmission can be increased to maximum power and is
1456also useful for understanding the different thermal modes available as
1457they differ between desk and lap mode.
1458
1459The property is read-only. If the platform doesn't have support the sysfs
1460class is not created.
1461
1462EXPERIMENTAL: UWB
1463-----------------
1464
1465This feature is considered EXPERIMENTAL because it has not been extensively
1466tested and validated in various ThinkPad models yet. The feature may not
1467work as expected. USE WITH CAUTION! To use this feature, you need to supply
1468the experimental=1 parameter when loading the module.
1469
1470sysfs rfkill class: switch "tpacpi_uwb_sw"
1471
1472This feature exports an rfkill controller for the UWB device, if one is
1473present and enabled in the BIOS.
1474
1475Sysfs notes
1476^^^^^^^^^^^
1477
1478 rfkill controller switch "tpacpi_uwb_sw": refer to
1479 Documentation/driver-api/rfkill.rst for details.
1480
1481
1482Setting keyboard language
1483-------------------------
1484
1485sysfs: keyboard_lang
1486
1487This feature is used to set keyboard language to ECFW using ASL interface.
1488Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1489")" numeric keys, which are not displaying correctly, when keyboard language
1490is other than "english". This is because the default keyboard language in ECFW
1491is set as "english". Hence using this sysfs, user can set the correct keyboard
1492language to ECFW and then these key's will work correctly.
1493
1494Example of command to set keyboard language is mentioned below::
1495
1496 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1497
1498Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1499cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1500fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1501nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden),
1502tr(Turkey)
1503
1504WWAN Antenna type
1505-----------------
1506
1507sysfs: wwan_antenna_type
1508
1509On some newer Thinkpads we need to set SAR value based on the antenna
1510type. This interface will be used by userspace to get the antenna type
1511and set the corresponding SAR value, as is required for FCC certification.
1512
1513The available commands are::
1514
1515 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1516
1517Currently 2 antenna types are supported as mentioned below:
1518- type a
1519- type b
1520
1521The property is read-only. If the platform doesn't have support the sysfs
1522class is not created.
1523
1524Auxmac
1525------
1526
1527sysfs: auxmac
1528
1529Some newer Thinkpads have a feature called MAC Address Pass-through. This
1530feature is implemented by the system firmware to provide a system unique MAC,
1531that can override a dock or USB ethernet dongle MAC, when connected to a
1532network. This property enables user-space to easily determine the MAC address
1533if the feature is enabled.
1534
1535The values of this auxiliary MAC are:
1536
1537 cat /sys/devices/platform/thinkpad_acpi/auxmac
1538
1539If the feature is disabled, the value will be 'disabled'.
1540
1541This property is read-only.
1542
1543Adaptive keyboard
1544-----------------
1545
1546sysfs device attribute: adaptive_kbd_mode
1547
1548This sysfs attribute controls the keyboard "face" that will be shown on the
1549Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1550and set.
1551
1552- 0 = Home mode
1553- 1 = Web-browser mode
1554- 2 = Web-conference mode
1555- 3 = Function mode
1556- 4 = Layflat mode
1557
1558For more details about which buttons will appear depending on the mode, please
1559review the laptop's user guide:
1560https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf
1561
1562Battery charge control
1563----------------------
1564
1565sysfs attributes:
1566/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1567
1568These two attributes are created for those batteries that are supported by the
1569driver. They enable the user to control the battery charge thresholds of the
1570given battery. Both values may be read and set. `charge_control_start_threshold`
1571accepts an integer between 0 and 99 (inclusive); this value represents a battery
1572percentage level, below which charging will begin. `charge_control_end_threshold`
1573accepts an integer between 1 and 100 (inclusive); this value represents a battery
1574percentage level, above which charging will stop.
1575
1576The exact semantics of the attributes may be found in
1577Documentation/ABI/testing/sysfs-class-power.
1578
1579Multiple Commands, Module Parameters
1580------------------------------------
1581
1582Multiple commands can be written to the proc files in one shot by
1583separating them with commas, for example::
1584
1585 echo enable,0xffff > /proc/acpi/ibm/hotkey
1586 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1587
1588Commands can also be specified when loading the thinkpad-acpi module,
1589for example::
1590
1591 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1592
1593
1594Enabling debugging output
1595-------------------------
1596
1597The module takes a debug parameter which can be used to selectively
1598enable various classes of debugging output, for example::
1599
1600 modprobe thinkpad_acpi debug=0xffff
1601
1602will enable all debugging output classes. It takes a bitmask, so
1603to enable more than one output class, just add their values.
1604
1605 ============= ======================================
1606 Debug bitmask Description
1607 ============= ======================================
1608 0x8000 Disclose PID of userspace programs
1609 accessing some functions of the driver
1610 0x0001 Initialization and probing
1611 0x0002 Removal
1612 0x0004 RF Transmitter control (RFKILL)
1613 (bluetooth, WWAN, UWB...)
1614 0x0008 HKEY event interface, hotkeys
1615 0x0010 Fan control
1616 0x0020 Backlight brightness
1617 0x0040 Audio mixer/volume control
1618 ============= ======================================
1619
1620There is also a kernel build option to enable more debugging
1621information, which may be necessary to debug driver problems.
1622
1623The level of debugging information output by the driver can be changed
1624at runtime through sysfs, using the driver attribute debug_level. The
1625attribute takes the same bitmask as the debug module parameter above.
1626
1627
1628Force loading of module
1629-----------------------
1630
1631If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1632the module parameter force_load=1. Regardless of whether this works or
1633not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1634
1635
1636Sysfs interface changelog
1637^^^^^^^^^^^^^^^^^^^^^^^^^
1638
1639========= ===============================================================
16400x000100: Initial sysfs support, as a single platform driver and
1641 device.
16420x000200: Hot key support for 32 hot keys, and radio slider switch
1643 support.
16440x010000: Hot keys are now handled by default over the input
1645 layer, the radio switch generates input event EV_RADIO,
1646 and the driver enables hot key handling by default in
1647 the firmware.
1648
16490x020000: ABI fix: added a separate hwmon platform device and
1650 driver, which must be located by name (thinkpad)
1651 and the hwmon class for libsensors4 (lm-sensors 3)
1652 compatibility. Moved all hwmon attributes to this
1653 new platform device.
1654
16550x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1656 support. If you must, use it to know you should not
1657 start a userspace NVRAM poller (allows to detect when
1658 NVRAM is compiled out by the user because it is
1659 unneeded/undesired in the first place).
16600x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1661 and proper hotkey_mask semantics (version 8 of the
1662 NVRAM polling patch). Some development snapshots of
1663 0.18 had an earlier version that did strange things
1664 to hotkey_mask.
1665
16660x020200: Add poll()/select() support to the following attributes:
1667 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1668
16690x020300: hotkey enable/disable support removed, attributes
1670 hotkey_bios_enabled and hotkey_enable deprecated and
1671 marked for removal.
1672
16730x020400: Marker for 16 LEDs support. Also, LEDs that are known
1674 to not exist in a given model are not registered with
1675 the LED sysfs class anymore.
1676
16770x020500: Updated hotkey driver, hotkey_mask is always available
1678 and it is always able to disable hot keys. Very old
1679 thinkpads are properly supported. hotkey_bios_mask
1680 is deprecated and marked for removal.
1681
16820x020600: Marker for backlight change event support.
1683
16840x020700: Support for mute-only mixers.
1685 Volume control in read-only mode by default.
1686 Marker for ALSA mixer support.
1687
16880x030000: Thermal and fan sysfs attributes were moved to the hwmon
1689 device instead of being attached to the backing platform
1690 device.
1691========= ===============================================================