1 ===========================
2 ThinkPad ACPI Extras Driver
3 ===========================
4
5 Version 0.25
6
7 October 16th, 2013
8
9 - Borislav Deianov <borislav@users.sf.net>
10 - Henrique de Moraes Holschuh <hmh@hmh.eng.br>
11
12 http://ibm-acpi.sf.net/
13
14 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
15 supports various features of these laptops which are accessible
16 through the ACPI and ACPI EC framework, but not otherwise fully
17 supported by the generic Linux ACPI drivers.
18
19 This driver used to be named ibm-acpi until kernel 2.6.21 and release
20 0.13-20070314. It used to be in the drivers/acpi tree, but it was
21 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
22 2.6.22, and release 0.14. It was moved to drivers/platform/x86 for
23 kernel 2.6.29 and release 0.22.
24
25 The driver is named "thinkpad-acpi". In some places, like module
26 names and log messages, "thinkpad_acpi" is used because of userspace
27 issues.
28
29 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
30 long due to length limitations on some Linux kernel versions.
31
32 Status
33 ------
34
35 The features currently supported are the following (see below for
36 detailed 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
58 A compatibility table by model and feature is maintained on the web
59 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
60 reports, especially if they add to or correct the compatibility table.
61 Please 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
70 Any other comments or patches are also more than welcome.
71
72
73 Installation
74 ------------
75
76 If you are compiling this driver as included in the Linux kernel
77 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
78 It is located on the menu path: "Device Drivers" -> "X86 Platform
79 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
80
81
82 Features
83 --------
84
85 The driver exports two different interfaces to userspace, which can be
86 used to access the features it provides. One is a legacy procfs-based
87 interface, which will be removed at some time in the future. The other
88 is a new sysfs-based interface which is not complete yet.
89
90 The procfs interface creates the /proc/acpi/ibm directory. There is a
91 file under that directory for each feature it supports. The procfs
92 interface is mostly frozen, and will change very little if at all: it
93 will not be extended to add any new functionality in the driver, instead
94 all new functionality will be implemented on the sysfs interface.
95
96 The sysfs interface tries to blend in the generic Linux sysfs subsystems
97 and classes as much as possible. Since some of these subsystems are not
98 yet ready or stabilized, it is expected that this interface will change,
99 and any and all userspace programs must deal with it.
100
101
102 Notes about the sysfs interface
103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
104
105 Unlike what was done with the procfs interface, correctness when talking
106 to the sysfs interfaces will be enforced, as will correctness in the
107 thinkpad-acpi's implementation of sysfs interfaces.
108
109 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
110 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
111 maximum correctness, even if that means changing an interface in
112 non-compatible ways. As these interfaces mature both in the kernel and
113 in thinkpad-acpi, such changes should become quite rare.
114
115 Applications interfacing to the thinkpad-acpi sysfs interfaces must
116 follow all sysfs guidelines and correctly process all errors (the sysfs
117 interface makes extensive use of errors). File descriptors and open /
118 close operations to the sysfs inodes must also be properly implemented.
119
120 The version of thinkpad-acpi's sysfs interface is exported by the driver
121 as a driver attribute (see below).
122
123 Sysfs driver attributes are on the driver's sysfs attribute space,
124 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
125 /sys/bus/platform/drivers/thinkpad_hwmon/
126
127 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
128 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
129
130 Sysfs device attributes for the sensors and fan are on the
131 thinkpad_hwmon device's sysfs attribute space, but you should locate it
132 looking for a hwmon device with the name attribute of "thinkpad", or
133 better yet, through libsensors. For 4.14+ sysfs attributes were moved to the
134 hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or
135 /sys/class/hwmon/hwmon?).
136
137 Driver version
138 --------------
139
140 procfs: /proc/acpi/ibm/driver
141
142 sysfs driver attribute: version
143
144 The driver name and version. No commands can be written to this file.
145
146
147 Sysfs interface version
148 -----------------------
149
150 sysfs driver attribute: interface_version
151
152 Version 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
162 The sysfs interface version changelog for the driver can be found at the
163 end of this document. Changes to the sysfs interface done by the kernel
164 subsystems are not documented here, nor are they tracked by this
165 attribute.
166
167 Changes to the thinkpad-acpi sysfs interface are only considered
168 non-experimental when they are submitted to Linux mainline, at which
169 point the changes in this interface are documented and interface_version
170 may be updated. If you are using any thinkpad-acpi features not yet
171 sent to mainline for merging, you do so on your own risk: these features
172 may disappear, or be implemented in a different and incompatible way by
173 the time they are merged in Linux mainline.
174
175 Changes that are backwards-compatible by nature (e.g. the addition of
176 attributes that do not change the way the other attributes work) do not
177 always warrant an update of interface_version. Therefore, one must
178 expect 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
180 feature is not available in sysfs).
181
182
183 Hot keys
184 --------
185
186 procfs: /proc/acpi/ibm/hotkey
187
188 sysfs device attribute: hotkey_*
189
190 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
191 some important events and also keyboard hot key presses to the operating
192 system. Enabling the hotkey functionality of thinkpad-acpi signals the
193 firmware that such a driver is present, and modifies how the ThinkPad
194 firmware will behave in many situations.
195
196 The driver enables the HKEY ("hot key") event reporting automatically
197 when loaded, and disables it when it is removed.
198
199 The driver will report HKEY events in the following format::
200
201 ibm/hotkey HKEY 00000080 0000xxxx
202
203 Some of these events refer to hot key presses, but not all of them.
204
205 The driver will generate events over the input layer for hot keys and
206 radio switches, and over the ACPI netlink layer for other events. The
207 input layer support accepts the standard IOCTLs to remap the keycodes
208 assigned to each hot key.
209
210 The hot key bit mask allows some control over which hot keys generate
211 events. If a key is "masked" (bit set to 0 in the mask), the firmware
212 will handle it. If it is "unmasked", it signals the firmware that
213 thinkpad-acpi would prefer to handle it, if the firmware would be so
214 kind to allow it (and it often doesn't!).
215
216 Not all bits in the mask can be modified. Not all bits that can be
217 modified do anything. Not all hot keys can be individually controlled
218 by the mask. Some models do not support the mask at all. The behaviour
219 of the mask is, therefore, highly dependent on the ThinkPad model.
220
221 The driver will filter out any unmasked hotkeys, so even if the firmware
222 doesn't allow disabling an specific hotkey, the driver will not report
223 events for unmasked hotkeys.
224
225 Note that unmasking some keys prevents their default behavior. For
226 example, if Fn+F5 is unmasked, that key will no longer enable/disable
227 Bluetooth by itself in firmware.
228
229 Note also that not all Fn key combinations are supported through ACPI
230 depending on the ThinkPad model and firmware version. On those
231 ThinkPads, it is still possible to support some extra hotkeys by
232 polling the "CMOS NVRAM" at least 10 times per second. The driver
233 attempts to enables this functionality automatically when required.
234
235 procfs notes
236 ^^^^^^^^^^^^
237
238 The 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
245 The following commands have been deprecated and will cause the kernel
246 to log a warning::
247
248 echo enable > /proc/acpi/ibm/hotkey -- does nothing
249 echo disable > /proc/acpi/ibm/hotkey -- returns an error
250
251 The procfs interface does not support NVRAM polling control. So as to
252 maintain maximum bug-to-bug compatibility, it does not report any masks,
253 nor does it allow one to manipulate the hot key mask when the firmware
254 does not support masks at all, even if NVRAM polling is in use.
255
256 sysfs 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
369 input layer notes
370 ^^^^^^^^^^^^^^^^^
371
372 A Hot key is mapped to a single input layer EV_KEY event, possibly
373 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
374 code. An EV_SYN event will always be generated to mark the end of the
375 event block.
376
377 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
378 used as a helper to remap keys, only. They are particularly useful when
379 remapping KEY_UNKNOWN keys.
380
381 The 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
391 The version will have its LSB incremented if the keymap changes in a
392 backwards-compatible way. The MSB shall always be 0x41 for this input
393 device. If the MSB is not 0x41, do not use the device as described in
394 this section, as it is either something else (e.g. another input device
395 exported by a thinkpad driver, such as HDAPS) or its functionality has
396 been changed in a non-backwards compatible way.
397
398 Adding other event types for other functionalities shall be considered a
399 backwards-compatible change for this input device.
400
401 Thinkpad-acpi Hot Key event map (version 0x4101):
402
403 ======= ======= ============== ==============================================
404 ACPI Scan
405 event code Key Notes
406 ======= ======= ============== ==============================================
407 0x1001 0x00 FN+F1 -
408
409 0x1002 0x01 FN+F2 IBM: battery (rare)
410 Lenovo: Screen lock
411
412 0x1003 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
420 0x1004 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
431 0x1005 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
440 0x1006 0x05 FN+F6 -
441
442 0x1007 0x06 FN+F7 Video output cycle.
443 Do you feel lucky today?
444
445 0x1008 0x07 FN+F8 IBM: toggle screen expand
446 Lenovo: configure UltraNav,
447 or toggle screen expand.
448 On newer platforms (2024+)
449 replaced by 0x131f (see below)
450
451 0x1009 0x08 FN+F9 -
452
453 ... ... ... ...
454
455 0x100B 0x0A FN+F11 -
456
457 0x100C 0x0B FN+F12 Sleep to disk. You are always
458 supposed to handle it yourself,
459 either through the ACPI event,
460 or through a hotkey event.
461 The firmware may refuse to
462 generate further FN+F12 key
463 press events until a S3 or S4
464 ACPI sleep cycle is performed,
465 or some time passes.
466
467 0x100D 0x0C FN+BACKSPACE -
468 0x100E 0x0D FN+INSERT -
469 0x100F 0x0E FN+DELETE -
470
471 0x1010 0x0F FN+HOME Brightness up. This key is
472 always handled by the firmware
473 in IBM ThinkPads, even when
474 unmasked. Just leave it alone.
475 For Lenovo ThinkPads with a new
476 BIOS, it has to be handled either
477 by the ACPI OSI, or by userspace.
478 The driver does the right thing,
479 never mess with this.
480 0x1011 0x10 FN+END Brightness down. See brightness
481 up for details.
482
483 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
484 always handled by the firmware,
485 even when unmasked.
486
487 0x1013 0x12 FN+PGDOWN -
488
489 0x1014 0x13 FN+SPACE Zoom key
490
491 0x1015 0x14 VOLUME UP Internal mixer volume up. This
492 key is always handled by the
493 firmware, even when unmasked.
494 NOTE: Lenovo seems to be changing
495 this.
496 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
497 key is always handled by the
498 firmware, even when unmasked.
499 NOTE: Lenovo seems to be changing
500 this.
501 0x1017 0x16 MUTE Mute internal mixer. This
502 key is always handled by the
503 firmware, even when unmasked.
504
505 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
506
507 0x1019 0x18 unknown
508
509 0x131f ... FN+F8 Platform Mode change.
510 Implemented in driver.
511
512 ... ... ...
513
514 0x1020 0x1F unknown
515 ======= ======= ============== ==============================================
516
517 The ThinkPad firmware does not allow one to differentiate when most hot
518 keys are pressed or released (either that, or we don't know how to, yet).
519 For these keys, the driver generates a set of events for a key press and
520 immediately issues the same set of events for a key release. It is
521 unknown by the driver if the ThinkPad firmware triggered these events on
522 hot key press or release, but the firmware will do it for either one, not
523 both.
524
525 If a key is mapped to KEY_RESERVED, it generates no input events at all.
526 If a key is mapped to KEY_UNKNOWN, it generates an input event that
527 includes an scan code. If a key is mapped to anything else, it will
528 generate input device EV_KEY events.
529
530 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
531 events for switches:
532
533 ============== ==============================================
534 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
535 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
536 ============== ==============================================
537
538 Non hotkey ACPI HKEY event map
539 ------------------------------
540
541 Events that are never propagated by the driver:
542
543 ====== ==================================================
544 0x2304 System is waking up from suspend to undock
545 0x2305 System is waking up from suspend to eject bay
546 0x2404 System is waking up from hibernation to undock
547 0x2405 System is waking up from hibernation to eject bay
548 0x5001 Lid closed
549 0x5002 Lid opened
550 0x5009 Tablet swivel: switched to tablet mode
551 0x500A Tablet swivel: switched to normal mode
552 0x5010 Brightness level changed/control event
553 0x6000 KEYBOARD: Numlock key pressed
554 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
555 0x7000 Radio Switch may have changed state
556 ====== ==================================================
557
558
559 Events that are propagated by the driver to userspace:
560
561 ====== =====================================================
562 0x2313 ALARM: System is waking up from suspend because
563 the battery is nearly empty
564 0x2413 ALARM: System is waking up from hibernation because
565 the battery is nearly empty
566 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
567 0x3006 Bay hotplug request (hint to power up SATA link when
568 the optical drive tray is ejected)
569 0x4003 Undocked (see 0x2x04), can sleep again
570 0x4010 Docked into hotplug port replicator (non-ACPI dock)
571 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
572 0x500B Tablet pen inserted into its storage bay
573 0x500C Tablet pen removed from its storage bay
574 0x6011 ALARM: battery is too hot
575 0x6012 ALARM: battery is extremely hot
576 0x6021 ALARM: a sensor is too hot
577 0x6022 ALARM: a sensor is extremely hot
578 0x6030 System thermal table changed
579 0x6032 Thermal Control command set completion (DYTC, Windows)
580 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
581 0x60C0 X1 Yoga 2016, Tablet mode status changed
582 0x60F0 Thermal Transformation changed (GMTS, Windows)
583 ====== =====================================================
584
585 Battery nearly empty alarms are a last resort attempt to get the
586 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
587 cleanly (0x2413) before power is lost. They must be acted upon, as the
588 wake up caused by the firmware will have negated most safety nets...
589
590 When any of the "too hot" alarms happen, according to Lenovo the user
591 should suspend or hibernate the laptop (and in the case of battery
592 alarms, unplug the AC adapter) to let it cool down. These alarms do
593 signal that something is wrong, they should never happen on normal
594 operating conditions.
595
596 The "extremely hot" alarms are emergencies. According to Lenovo, the
597 operating system is to force either an immediate suspend or hibernate
598 cycle, or a system shutdown. Obviously, something is very wrong if this
599 happens.
600
601
602 Brightness hotkey notes
603 ^^^^^^^^^^^^^^^^^^^^^^^
604
605 Don't mess with the brightness hotkeys in a Thinkpad. If you want
606 notifications for OSD, use the sysfs backlight class event support.
607
608 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
609 automatically for the cases were userspace has to do something to
610 implement brightness changes. When you override these events, you will
611 either fail to handle properly the ThinkPads that require explicit
612 action to change backlight brightness, or the ThinkPads that require
613 that no action be taken to work properly.
614
615
616 Bluetooth
617 ---------
618
619 procfs: /proc/acpi/ibm/bluetooth
620
621 sysfs device attribute: bluetooth_enable (deprecated)
622
623 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
624
625 This feature shows the presence and current state of a ThinkPad
626 Bluetooth device in the internal ThinkPad CDC slot.
627
628 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
629 so it is kept across reboots and power-off.
630
631 Procfs notes
632 ^^^^^^^^^^^^
633
634 If Bluetooth is installed, the following commands can be used::
635
636 echo enable > /proc/acpi/ibm/bluetooth
637 echo disable > /proc/acpi/ibm/bluetooth
638
639 Sysfs notes
640 ^^^^^^^^^^^
641
642 If the Bluetooth CDC card is installed, it can be enabled /
643 disabled through the "bluetooth_enable" thinkpad-acpi device
644 attribute, and its current status can also be queried.
645
646 enable:
647
648 - 0: disables Bluetooth / Bluetooth is disabled
649 - 1: enables Bluetooth / Bluetooth is enabled.
650
651 Note: this interface has been superseded by the generic rfkill
652 class. It has been deprecated, and it will be removed in year
653 2010.
654
655 rfkill controller switch "tpacpi_bluetooth_sw": refer to
656 Documentation/driver-api/rfkill.rst for details.
657
658
659 Video output control -- /proc/acpi/ibm/video
660 --------------------------------------------
661
662 This feature allows control over the devices used for video output -
663 LCD, CRT or DVI (if available). The following commands are available::
664
665 echo lcd_enable > /proc/acpi/ibm/video
666 echo lcd_disable > /proc/acpi/ibm/video
667 echo crt_enable > /proc/acpi/ibm/video
668 echo crt_disable > /proc/acpi/ibm/video
669 echo dvi_enable > /proc/acpi/ibm/video
670 echo dvi_disable > /proc/acpi/ibm/video
671 echo auto_enable > /proc/acpi/ibm/video
672 echo auto_disable > /proc/acpi/ibm/video
673 echo expand_toggle > /proc/acpi/ibm/video
674 echo video_switch > /proc/acpi/ibm/video
675
676 NOTE:
677 Access to this feature is restricted to processes owning the
678 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
679 enough with some versions of X.org to crash it.
680
681 Each video output device can be enabled or disabled individually.
682 Reading /proc/acpi/ibm/video shows the status of each device.
683
684 Automatic video switching can be enabled or disabled. When automatic
685 video switching is enabled, certain events (e.g. opening the lid,
686 docking or undocking) cause the video output device to change
687 automatically. While this can be useful, it also causes flickering
688 and, on the X40, video corruption. By disabling automatic switching,
689 the flickering or video corruption can be avoided.
690
691 The video_switch command cycles through the available video outputs
692 (it simulates the behavior of Fn-F7).
693
694 Video expansion can be toggled through this feature. This controls
695 whether the display is expanded to fill the entire LCD screen when a
696 mode with less than full resolution is used. Note that the current
697 video expansion status cannot be determined through this feature.
698
699 Note that on many models (particularly those using Radeon graphics
700 chips) the X driver configures the video card in a way which prevents
701 Fn-F7 from working. This also disables the video output switching
702 features of this driver, as it uses the same ACPI methods as
703 Fn-F7. Video switching on the console should still work.
704
705 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
706
707
708 ThinkLight control
709 ------------------
710
711 procfs: /proc/acpi/ibm/light
712
713 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
714
715 procfs notes
716 ^^^^^^^^^^^^
717
718 The ThinkLight status can be read and set through the procfs interface. A
719 few models which do not make the status available will show the ThinkLight
720 status as "unknown". The available commands are::
721
722 echo on > /proc/acpi/ibm/light
723 echo off > /proc/acpi/ibm/light
724
725 sysfs notes
726 ^^^^^^^^^^^
727
728 The ThinkLight sysfs interface is documented by the LED class
729 documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
730 is "tpacpi::thinklight".
731
732 Due to limitations in the sysfs LED class, if the status of the ThinkLight
733 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
734 It is impossible to know if the status returned through sysfs is valid.
735
736
737 CMOS/UCMS control
738 -----------------
739
740 procfs: /proc/acpi/ibm/cmos
741
742 sysfs device attribute: cmos_command
743
744 This feature is mostly used internally by the ACPI firmware to keep the legacy
745 CMOS NVRAM bits in sync with the current machine state, and to record this
746 state so that the ThinkPad will retain such settings across reboots.
747
748 Some of these commands actually perform actions in some ThinkPad models, but
749 this is expected to disappear more and more in newer models. As an example, in
750 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
751 real, but commands 0 to 2 don't control the mixer anymore (they have been
752 phased out) and just update the NVRAM.
753
754 The range of valid cmos command numbers is 0 to 21, but not all have an
755 effect and the behavior varies from model to model. Here is the behavior
756 on the X40 (tpb is the ThinkPad Buttons utility):
757
758 - 0 - Related to "Volume down" key press
759 - 1 - Related to "Volume up" key press
760 - 2 - Related to "Mute on" key press
761 - 3 - Related to "Access IBM" key press
762 - 4 - Related to "LCD brightness up" key press
763 - 5 - Related to "LCD brightness down" key press
764 - 11 - Related to "toggle screen expansion" key press/function
765 - 12 - Related to "ThinkLight on"
766 - 13 - Related to "ThinkLight off"
767 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
768
769 The cmos command interface is prone to firmware split-brain problems, as
770 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
771 exported just as a debug tool.
772
773
774 LED control
775 -----------
776
777 procfs: /proc/acpi/ibm/led
778 sysfs attributes: as per LED class, see below for names
779
780 Some of the LED indicators can be controlled through this feature. On
781 some older ThinkPad models, it is possible to query the status of the
782 LED indicators as well. Newer ThinkPads cannot query the real status
783 of the LED indicators.
784
785 Because misuse of the LEDs could induce an unaware user to perform
786 dangerous actions (like undocking or ejecting a bay device while the
787 buses are still active), or mask an important alarm (such as a nearly
788 empty battery, or a broken battery), access to most LEDs is
789 restricted.
790
791 Unrestricted access to all LEDs requires that thinkpad-acpi be
792 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
793 Distributions must never enable this option. Individual users that
794 are aware of the consequences are welcome to enabling it.
795
796 Audio mute and microphone mute LEDs are supported, but currently not
797 visible to userspace. They are used by the snd-hda-intel audio driver.
798
799 procfs notes
800 ^^^^^^^^^^^^
801
802 The available commands are::
803
804 echo '<LED number> on' >/proc/acpi/ibm/led
805 echo '<LED number> off' >/proc/acpi/ibm/led
806 echo '<LED number> blink' >/proc/acpi/ibm/led
807
808 The <LED number> range is 0 to 15. The set of LEDs that can be
809 controlled varies from model to model. Here is the common ThinkPad
810 mapping:
811
812 - 0 - power
813 - 1 - battery (orange)
814 - 2 - battery (green)
815 - 3 - UltraBase/dock
816 - 4 - UltraBay
817 - 5 - UltraBase battery slot
818 - 6 - (unknown)
819 - 7 - standby
820 - 8 - dock status 1
821 - 9 - dock status 2
822 - 10, 11 - (unknown)
823 - 12 - thinkvantage
824 - 13, 14, 15 - (unknown)
825
826 All of the above can be turned on and off and can be made to blink.
827
828 sysfs notes
829 ^^^^^^^^^^^
830
831 The ThinkPad LED sysfs interface is described in detail by the LED class
832 documentation, in Documentation/leds/leds-class.rst.
833
834 The LEDs are named (in LED ID order, from 0 to 12):
835 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
836 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
837 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
838 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
839 "tpacpi::thinkvantage".
840
841 Due to limitations in the sysfs LED class, if the status of the LED
842 indicators cannot be read due to an error, thinkpad-acpi will report it as
843 a brightness of zero (same as LED off).
844
845 If the thinkpad firmware doesn't support reading the current status,
846 trying to read the current LED brightness will just return whatever
847 brightness was last written to that attribute.
848
849 These LEDs can blink using hardware acceleration. To request that a
850 ThinkPad indicator LED should blink in hardware accelerated mode, use the
851 "timer" trigger, and leave the delay_on and delay_off parameters set to
852 zero (to request hardware acceleration autodetection).
853
854 LEDs that are known not to exist in a given ThinkPad model are not
855 made available through the sysfs interface. If you have a dock and you
856 notice there are LEDs listed for your ThinkPad that do not exist (and
857 are not in the dock), or if you notice that there are missing LEDs,
858 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
859
860
861 ACPI sounds -- /proc/acpi/ibm/beep
862 ----------------------------------
863
864 The BEEP method is used internally by the ACPI firmware to provide
865 audible alerts in various situations. This feature allows the same
866 sounds to be triggered manually.
867
868 The commands are non-negative integer numbers::
869
870 echo <number> >/proc/acpi/ibm/beep
871
872 The valid <number> range is 0 to 17. Not all numbers trigger sounds
873 and the sounds vary from model to model. Here is the behavior on the
874 X40:
875
876 - 0 - stop a sound in progress (but use 17 to stop 16)
877 - 2 - two beeps, pause, third beep ("low battery")
878 - 3 - single beep
879 - 4 - high, followed by low-pitched beep ("unable")
880 - 5 - single beep
881 - 6 - very high, followed by high-pitched beep ("AC/DC")
882 - 7 - high-pitched beep
883 - 9 - three short beeps
884 - 10 - very long beep
885 - 12 - low-pitched beep
886 - 15 - three high-pitched beeps repeating constantly, stop with 0
887 - 16 - one medium-pitched beep repeating constantly, stop with 17
888 - 17 - stop 16
889
890
891 Temperature sensors
892 -------------------
893
894 procfs: /proc/acpi/ibm/thermal
895
896 sysfs device attributes: (hwmon "thinkpad") temp*_input
897
898 Most ThinkPads include six or more separate temperature sensors but only
899 expose the CPU temperature through the standard ACPI methods. This
900 feature shows readings from up to eight different sensors on older
901 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
902
903 For example, on the X40, a typical output may be:
904
905 temperatures:
906 42 42 45 41 36 -128 33 -128
907
908 On the T43/p, a typical output may be:
909
910 temperatures:
911 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
912
913 The mapping of thermal sensors to physical locations varies depending on
914 system-board model (and thus, on ThinkPad model).
915
916 https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
917 tries to track down these locations for various models.
918
919 Most (newer?) models seem to follow this pattern:
920
921 - 1: CPU
922 - 2: (depends on model)
923 - 3: (depends on model)
924 - 4: GPU
925 - 5: Main battery: main sensor
926 - 6: Bay battery: main sensor
927 - 7: Main battery: secondary sensor
928 - 8: Bay battery: secondary sensor
929 - 9-15: (depends on model)
930
931 For the R51 (source: Thomas Gruber):
932
933 - 2: Mini-PCI
934 - 3: Internal HDD
935
936 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
937 https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
938
939 - 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
940 - 3: PCMCIA slot
941 - 9: MCH (northbridge) to DRAM Bus
942 - 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
943 card, under touchpad
944 - 11: Power regulator, underside of system board, below F2 key
945
946 The A31 has a very atypical layout for the thermal sensors
947 (source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
948
949 - 1: CPU
950 - 2: Main Battery: main sensor
951 - 3: Power Converter
952 - 4: Bay Battery: main sensor
953 - 5: MCH (northbridge)
954 - 6: PCMCIA/ambient
955 - 7: Main Battery: secondary sensor
956 - 8: Bay Battery: secondary sensor
957
958
959 Procfs notes
960 ^^^^^^^^^^^^
961
962 Readings from sensors that are not available return -128.
963 No commands can be written to this file.
964
965 Sysfs notes
966 ^^^^^^^^^^^
967
968 Sensors that are not available return the ENXIO error. This
969 status may change at runtime, as there are hotplug thermal
970 sensors, like those inside the batteries and docks.
971
972 thinkpad-acpi thermal sensors are reported through the hwmon
973 subsystem, and follow all of the hwmon guidelines at
974 Documentation/hwmon.
975
976 EXPERIMENTAL: Embedded controller register dump
977 -----------------------------------------------
978
979 This feature is not included in the thinkpad driver anymore.
980 Instead the EC can be accessed through /sys/kernel/debug/ec with
981 a userspace tool which can be found here:
982 ftp://ftp.suse.com/pub/people/trenn/sources/ec
983
984 Use it to determine the register holding the fan
985 speed on some models. To do that, do the following:
986
987 - make sure the battery is fully charged
988 - make sure the fan is running
989 - use above mentioned tool to read out the EC
990
991 Often fan and temperature values vary between
992 readings. Since temperatures don't change vary fast, you can take
993 several quick dumps to eliminate them.
994
995 You can use a similar method to figure out the meaning of other
996 embedded controller registers - e.g. make sure nothing else changes
997 except the charging or discharging battery to determine which
998 registers contain the current battery capacity, etc. If you experiment
999 with this, do send me your results (including some complete dumps with
1000 a description of the conditions when they were taken.)
1001
1002
1003 LCD brightness control
1004 ----------------------
1005
1006 procfs: /proc/acpi/ibm/brightness
1007
1008 sysfs backlight device "thinkpad_screen"
1009
1010 This feature allows software control of the LCD brightness on ThinkPad
1011 models which don't have a hardware brightness slider.
1012
1013 It has some limitations: the LCD backlight cannot be actually turned
1014 on or off by this interface, it just controls the backlight brightness
1015 level.
1016
1017 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1018 has eight brightness levels, ranging from 0 to 7. Some of the levels
1019 may not be distinct. Later Lenovo models that implement the ACPI
1020 display backlight brightness control methods have 16 levels, ranging
1021 from 0 to 15.
1022
1023 For IBM ThinkPads, there are two interfaces to the firmware for direct
1024 brightness control, EC and UCMS (or CMOS). To select which one should be
1025 used, use the brightness_mode module parameter: brightness_mode=1 selects
1026 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1027 mode with NVRAM backing (so that brightness changes are remembered across
1028 shutdown/reboot).
1029
1030 The driver tries to select which interface to use from a table of
1031 defaults for each ThinkPad model. If it makes a wrong choice, please
1032 report this as a bug, so that we can fix it.
1033
1034 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1035
1036 When display backlight brightness controls are available through the
1037 standard ACPI interface, it is best to use it instead of this direct
1038 ThinkPad-specific interface. The driver will disable its native
1039 backlight brightness control interface if it detects that the standard
1040 ACPI interface is available in the ThinkPad.
1041
1042 If you want to use the thinkpad-acpi backlight brightness control
1043 instead of the generic ACPI video backlight brightness control for some
1044 reason, you should use the acpi_backlight=vendor kernel parameter.
1045
1046 The brightness_enable module parameter can be used to control whether
1047 the LCD brightness control feature will be enabled when available.
1048 brightness_enable=0 forces it to be disabled. brightness_enable=1
1049 forces it to be enabled when available, even if the standard ACPI
1050 interface is also available.
1051
1052 Procfs notes
1053 ^^^^^^^^^^^^
1054
1055 The available commands are::
1056
1057 echo up >/proc/acpi/ibm/brightness
1058 echo down >/proc/acpi/ibm/brightness
1059 echo 'level <level>' >/proc/acpi/ibm/brightness
1060
1061 Sysfs notes
1062 ^^^^^^^^^^^
1063
1064 The interface is implemented through the backlight sysfs class, which is
1065 poorly documented at this time.
1066
1067 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1068 it there will be the following attributes:
1069
1070 max_brightness:
1071 Reads the maximum brightness the hardware can be set to.
1072 The minimum is always zero.
1073
1074 actual_brightness:
1075 Reads what brightness the screen is set to at this instant.
1076
1077 brightness:
1078 Writes request the driver to change brightness to the
1079 given value. Reads will tell you what brightness the
1080 driver is trying to set the display to when "power" is set
1081 to zero and the display has not been dimmed by a kernel
1082 power management event.
1083
1084 power:
1085 power management mode, where 0 is "display on", and 1 to 3
1086 will dim the display backlight to brightness level 0
1087 because thinkpad-acpi cannot really turn the backlight
1088 off. Kernel power management events can temporarily
1089 increase the current power management level, i.e. they can
1090 dim the display.
1091
1092
1093 WARNING:
1094
1095 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1096 interface and the ACPI-based backlight level change interface
1097 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1098 at the same time. The two will interact in bad ways, do funny things,
1099 and maybe reduce the life of the backlight lamps by needlessly kicking
1100 its level up and down at every change.
1101
1102
1103 Volume control (Console Audio control)
1104 --------------------------------------
1105
1106 procfs: /proc/acpi/ibm/volume
1107
1108 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1109
1110 NOTE: by default, the volume control interface operates in read-only
1111 mode, as it is supposed to be used for on-screen-display purposes.
1112 The read/write mode can be enabled through the use of the
1113 "volume_control=1" module parameter.
1114
1115 NOTE: distros are urged to not enable volume_control by default, this
1116 should be done by the local admin only. The ThinkPad UI is for the
1117 console audio control to be done through the volume keys only, and for
1118 the desktop environment to just provide on-screen-display feedback.
1119 Software volume control should be done only in the main AC97/HDA
1120 mixer.
1121
1122
1123 About the ThinkPad Console Audio control
1124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1125
1126 ThinkPads have a built-in amplifier and muting circuit that drives the
1127 console headphone and speakers. This circuit is after the main AC97
1128 or HDA mixer in the audio path, and under exclusive control of the
1129 firmware.
1130
1131 ThinkPads have three special hotkeys to interact with the console
1132 audio control: volume up, volume down and mute.
1133
1134 It is worth noting that the normal way the mute function works (on
1135 ThinkPads that do not have a "mute LED") is:
1136
1137 1. Press mute to mute. It will *always* mute, you can press it as
1138 many times as you want, and the sound will remain mute.
1139
1140 2. Press either volume key to unmute the ThinkPad (it will _not_
1141 change the volume, it will just unmute).
1142
1143 This is a very superior design when compared to the cheap software-only
1144 mute-toggle solution found on normal consumer laptops: you can be
1145 absolutely sure the ThinkPad will not make noise if you press the mute
1146 button, no matter the previous state.
1147
1148 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1149 amplifiers driving the speakers and headphone output, and the firmware
1150 also handles volume control for the headphone and speakers on these
1151 ThinkPads without any help from the operating system (this volume
1152 control stage exists after the main AC97 or HDA mixer in the audio
1153 path).
1154
1155 The newer Lenovo models only have firmware mute control, and depend on
1156 the main HDA mixer to do volume control (which is done by the operating
1157 system). In this case, the volume keys are filtered out for unmute
1158 key press (there are some firmware bugs in this area) and delivered as
1159 normal key presses to the operating system (thinkpad-acpi is not
1160 involved).
1161
1162
1163 The ThinkPad-ACPI volume control
1164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1165
1166 The preferred way to interact with the Console Audio control is the
1167 ALSA interface.
1168
1169 The legacy procfs interface allows one to read the current state,
1170 and if volume control is enabled, accepts the following commands::
1171
1172 echo up >/proc/acpi/ibm/volume
1173 echo down >/proc/acpi/ibm/volume
1174 echo mute >/proc/acpi/ibm/volume
1175 echo unmute >/proc/acpi/ibm/volume
1176 echo 'level <level>' >/proc/acpi/ibm/volume
1177
1178 The <level> number range is 0 to 14 although not all of them may be
1179 distinct. To unmute the volume after the mute command, use either the
1180 up or down command (the level command will not unmute the volume), or
1181 the unmute command.
1182
1183 You can use the volume_capabilities parameter to tell the driver
1184 whether your thinkpad has volume control or mute-only control:
1185 volume_capabilities=1 for mixers with mute and volume control,
1186 volume_capabilities=2 for mixers with only mute control.
1187
1188 If the driver misdetects the capabilities for your ThinkPad model,
1189 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1190 can update the driver.
1191
1192 There are two strategies for volume control. To select which one
1193 should be used, use the volume_mode module parameter: volume_mode=1
1194 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1195 (so that volume/mute changes are remembered across shutdown/reboot).
1196
1197 The driver will operate in volume_mode=3 by default. If that does not
1198 work well on your ThinkPad model, please report this to
1199 ibm-acpi-devel@lists.sourceforge.net.
1200
1201 The driver supports the standard ALSA module parameters. If the ALSA
1202 mixer is disabled, the driver will disable all volume functionality.
1203
1204
1205 Fan control and monitoring: fan speed, fan enable/disable
1206 ---------------------------------------------------------
1207
1208 procfs: /proc/acpi/ibm/fan
1209
1210 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1211
1212 sysfs hwmon driver attributes: fan_watchdog
1213
1214 NOTE NOTE NOTE:
1215 fan control operations are disabled by default for
1216 safety reasons. To enable them, the module parameter "fan_control=1"
1217 must be given to thinkpad-acpi.
1218
1219 This feature attempts to show the current fan speed, control mode and
1220 other fan data that might be available. The speed is read directly
1221 from the hardware registers of the embedded controller. This is known
1222 to work on later R, T, X and Z series ThinkPads but may show a bogus
1223 value on other models.
1224
1225 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1226 controlled separately, it shares the main fan control.
1227
1228 Fan levels
1229 ^^^^^^^^^^
1230
1231 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1232 stops the fan. The higher the level, the higher the fan speed, although
1233 adjacent levels often map to the same fan speed. 7 is the highest
1234 level, where the fan reaches the maximum recommended speed.
1235
1236 Level "auto" means the EC changes the fan level according to some
1237 internal algorithm, usually based on readings from the thermal sensors.
1238
1239 There is also a "full-speed" level, also known as "disengaged" level.
1240 In this level, the EC disables the speed-locked closed-loop fan control,
1241 and drives the fan as fast as it can go, which might exceed hardware
1242 limits, so use this level with caution.
1243
1244 The fan usually ramps up or down slowly from one speed to another, and
1245 it is normal for the EC to take several seconds to react to fan
1246 commands. The full-speed level may take up to two minutes to ramp up to
1247 maximum speed, and in some ThinkPads, the tachometer readings go stale
1248 while the EC is transitioning to the full-speed level.
1249
1250 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1251 monitoring all of the temperature sensor readings and you are ready to
1252 enable it if necessary to avoid overheating.
1253
1254 An enabled fan in level "auto" may stop spinning if the EC decides the
1255 ThinkPad is cool enough and doesn't need the extra airflow. This is
1256 normal, and the EC will spin the fan up if the various thermal readings
1257 rise too much.
1258
1259 On the X40, this seems to depend on the CPU and HDD temperatures.
1260 Specifically, the fan is turned on when either the CPU temperature
1261 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1262 fan is turned off when the CPU temperature drops to 49 degrees and the
1263 HDD temperature drops to 41 degrees. These thresholds cannot
1264 currently be controlled.
1265
1266 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1267 certain conditions are met. It will override any fan programming done
1268 through thinkpad-acpi.
1269
1270 The thinkpad-acpi kernel driver can be programmed to revert the fan
1271 level to a safe setting if userspace does not issue one of the procfs
1272 fan commands: "enable", "disable", "level" or "watchdog", or if there
1273 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1274 set to 1, manual mode) within a configurable amount of time of up to
1275 120 seconds. This functionality is called fan safety watchdog.
1276
1277 Note that the watchdog timer stops after it enables the fan. It will be
1278 rearmed again automatically (using the same interval) when one of the
1279 above mentioned fan commands is received. The fan watchdog is,
1280 therefore, not suitable to protect against fan mode changes made through
1281 means other than the "enable", "disable", and "level" procfs fan
1282 commands, or the hwmon fan control sysfs interface.
1283
1284 Procfs notes
1285 ^^^^^^^^^^^^
1286
1287 The fan may be enabled or disabled with the following commands::
1288
1289 echo enable >/proc/acpi/ibm/fan
1290 echo disable >/proc/acpi/ibm/fan
1291
1292 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1293 will try to place it in a safe level if it is too slow or disabled.
1294
1295 The fan level can be controlled with the command::
1296
1297 echo 'level <level>' > /proc/acpi/ibm/fan
1298
1299 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1300 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1301 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1302 "full-speed", and reports it as "disengaged" for backwards
1303 compatibility.
1304
1305 On the X31 and X40 (and ONLY on those models), the fan speed can be
1306 controlled to a certain degree. Once the fan is running, it can be
1307 forced to run faster or slower with the following command::
1308
1309 echo 'speed <speed>' > /proc/acpi/ibm/fan
1310
1311 The sustainable range of fan speeds on the X40 appears to be from about
1312 3700 to about 7350. Values outside this range either do not have any
1313 effect or the fan speed eventually settles somewhere in that range. The
1314 fan cannot be stopped or started with this command. This functionality
1315 is incomplete, and not available through the sysfs interface.
1316
1317 To program the safety watchdog, use the "watchdog" command::
1318
1319 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1320
1321 If you want to disable the watchdog, use 0 as the interval.
1322
1323 Sysfs notes
1324 ^^^^^^^^^^^
1325
1326 The sysfs interface follows the hwmon subsystem guidelines for the most
1327 part, and the exception is the fan safety watchdog.
1328
1329 Writes to any of the sysfs attributes may return the EINVAL error if
1330 that operation is not supported in a given ThinkPad or if the parameter
1331 is out-of-bounds, and EPERM if it is forbidden. They may also return
1332 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1333 to the firmware).
1334
1335 Features not yet implemented by the driver return ENOSYS.
1336
1337 hwmon device attribute pwm1_enable:
1338 - 0: PWM offline (fan is set to full-speed mode)
1339 - 1: Manual PWM control (use pwm1 to set fan level)
1340 - 2: Hardware PWM control (EC "auto" mode)
1341 - 3: reserved (Software PWM control, not implemented yet)
1342
1343 Modes 0 and 2 are not supported by all ThinkPads, and the
1344 driver is not always able to detect this. If it does know a
1345 mode is unsupported, it will return -EINVAL.
1346
1347 hwmon device attribute pwm1:
1348 Fan level, scaled from the firmware values of 0-7 to the hwmon
1349 scale of 0-255. 0 means fan stopped, 255 means highest normal
1350 speed (level 7).
1351
1352 This attribute only commands the fan if pmw1_enable is set to 1
1353 (manual PWM control).
1354
1355 hwmon device attribute fan1_input:
1356 Fan tachometer reading, in RPM. May go stale on certain
1357 ThinkPads while the EC transitions the PWM to offline mode,
1358 which can take up to two minutes. May return rubbish on older
1359 ThinkPads.
1360
1361 hwmon device attribute fan2_input:
1362 Fan tachometer reading, in RPM, for the secondary fan.
1363 Available only on some ThinkPads. If the secondary fan is
1364 not installed, will always read 0.
1365
1366 hwmon driver attribute fan_watchdog:
1367 Fan safety watchdog timer interval, in seconds. Minimum is
1368 1 second, maximum is 120 seconds. 0 disables the watchdog.
1369
1370 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1371
1372 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1373 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1374 would be the safest choice, though).
1375
1376
1377 WAN
1378 ---
1379
1380 procfs: /proc/acpi/ibm/wan
1381
1382 sysfs device attribute: wwan_enable (deprecated)
1383
1384 sysfs rfkill class: switch "tpacpi_wwan_sw"
1385
1386 This feature shows the presence and current state of the built-in
1387 Wireless WAN device.
1388
1389 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1390 so it is kept across reboots and power-off.
1391
1392 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1393 ThinkPad models which come with this module installed.
1394
1395 Procfs notes
1396 ^^^^^^^^^^^^
1397
1398 If the W-WAN card is installed, the following commands can be used::
1399
1400 echo enable > /proc/acpi/ibm/wan
1401 echo disable > /proc/acpi/ibm/wan
1402
1403 Sysfs notes
1404 ^^^^^^^^^^^
1405
1406 If the W-WAN card is installed, it can be enabled /
1407 disabled through the "wwan_enable" thinkpad-acpi device
1408 attribute, and its current status can also be queried.
1409
1410 enable:
1411 - 0: disables WWAN card / WWAN card is disabled
1412 - 1: enables WWAN card / WWAN card is enabled.
1413
1414 Note: this interface has been superseded by the generic rfkill
1415 class. It has been deprecated, and it will be removed in year
1416 2010.
1417
1418 rfkill controller switch "tpacpi_wwan_sw": refer to
1419 Documentation/driver-api/rfkill.rst for details.
1420
1421
1422 LCD Shadow control
1423 ------------------
1424
1425 procfs: /proc/acpi/ibm/lcdshadow
1426
1427 Some newer T480s and T490s ThinkPads provide a feature called
1428 PrivacyGuard. By turning this feature on, the usable vertical and
1429 horizontal viewing angles of the LCD can be limited (as if some privacy
1430 screen was applied manually in front of the display).
1431
1432 procfs notes
1433 ^^^^^^^^^^^^
1434
1435 The available commands are::
1436
1437 echo '0' >/proc/acpi/ibm/lcdshadow
1438 echo '1' >/proc/acpi/ibm/lcdshadow
1439
1440 The first command ensures the best viewing angle and the latter one turns
1441 on the feature, restricting the viewing angles.
1442
1443
1444 DYTC Lapmode sensor
1445 -------------------
1446
1447 sysfs: dytc_lapmode
1448
1449 Newer thinkpads and mobile workstations have the ability to determine if
1450 the device is in deskmode or lapmode. This feature is used by user space
1451 to decide if WWAN transmission can be increased to maximum power and is
1452 also useful for understanding the different thermal modes available as
1453 they differ between desk and lap mode.
1454
1455 The property is read-only. If the platform doesn't have support the sysfs
1456 class is not created.
1457
1458 EXPERIMENTAL: UWB
1459 -----------------
1460
1461 This feature is considered EXPERIMENTAL because it has not been extensively
1462 tested and validated in various ThinkPad models yet. The feature may not
1463 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1464 the experimental=1 parameter when loading the module.
1465
1466 sysfs rfkill class: switch "tpacpi_uwb_sw"
1467
1468 This feature exports an rfkill controller for the UWB device, if one is
1469 present and enabled in the BIOS.
1470
1471 Sysfs notes
1472 ^^^^^^^^^^^
1473
1474 rfkill controller switch "tpacpi_uwb_sw": refer to
1475 Documentation/driver-api/rfkill.rst for details.
1476
1477
1478 Setting keyboard language
1479 -------------------------
1480
1481 sysfs: keyboard_lang
1482
1483 This feature is used to set keyboard language to ECFW using ASL interface.
1484 Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1485 ")" numeric keys, which are not displaying correctly, when keyboard language
1486 is other than "english". This is because the default keyboard language in ECFW
1487 is set as "english". Hence using this sysfs, user can set the correct keyboard
1488 language to ECFW and then these key's will work correctly.
1489
1490 Example of command to set keyboard language is mentioned below::
1491
1492 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1493
1494 Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1495 cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1496 fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1497 nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden),
1498 tr(Turkey)
1499
1500 WWAN Antenna type
1501 -----------------
1502
1503 sysfs: wwan_antenna_type
1504
1505 On some newer Thinkpads we need to set SAR value based on the antenna
1506 type. This interface will be used by userspace to get the antenna type
1507 and set the corresponding SAR value, as is required for FCC certification.
1508
1509 The available commands are::
1510
1511 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1512
1513 Currently 2 antenna types are supported as mentioned below:
1514 - type a
1515 - type b
1516
1517 The property is read-only. If the platform doesn't have support the sysfs
1518 class is not created.
1519
1520 Auxmac
1521 ------
1522
1523 sysfs: auxmac
1524
1525 Some newer Thinkpads have a feature called MAC Address Pass-through. This
1526 feature is implemented by the system firmware to provide a system unique MAC,
1527 that can override a dock or USB ethernet dongle MAC, when connected to a
1528 network. This property enables user-space to easily determine the MAC address
1529 if the feature is enabled.
1530
1531 The values of this auxiliary MAC are:
1532
1533 cat /sys/devices/platform/thinkpad_acpi/auxmac
1534
1535 If the feature is disabled, the value will be 'disabled'.
1536
1537 This property is read-only.
1538
1539 Adaptive keyboard
1540 -----------------
1541
1542 sysfs device attribute: adaptive_kbd_mode
1543
1544 This sysfs attribute controls the keyboard "face" that will be shown on the
1545 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1546 and set.
1547
1548 - 0 = Home mode
1549 - 1 = Web-browser mode
1550 - 2 = Web-conference mode
1551 - 3 = Function mode
1552 - 4 = Layflat mode
1553
1554 For more details about which buttons will appear depending on the mode, please
1555 review the laptop's user guide:
1556 https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf
1557
1558 Battery charge control
1559 ----------------------
1560
1561 sysfs attributes:
1562 /sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1563
1564 These two attributes are created for those batteries that are supported by the
1565 driver. They enable the user to control the battery charge thresholds of the
1566 given battery. Both values may be read and set. `charge_control_start_threshold`
1567 accepts an integer between 0 and 99 (inclusive); this value represents a battery
1568 percentage level, below which charging will begin. `charge_control_end_threshold`
1569 accepts an integer between 1 and 100 (inclusive); this value represents a battery
1570 percentage level, above which charging will stop.
1571
1572 The exact semantics of the attributes may be found in
1573 Documentation/ABI/testing/sysfs-class-power.
1574
1575 Multiple Commands, Module Parameters
1576 ------------------------------------
1577
1578 Multiple commands can be written to the proc files in one shot by
1579 separating them with commas, for example::
1580
1581 echo enable,0xffff > /proc/acpi/ibm/hotkey
1582 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1583
1584 Commands can also be specified when loading the thinkpad-acpi module,
1585 for example::
1586
1587 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1588
1589
1590 Enabling debugging output
1591 -------------------------
1592
1593 The module takes a debug parameter which can be used to selectively
1594 enable various classes of debugging output, for example::
1595
1596 modprobe thinkpad_acpi debug=0xffff
1597
1598 will enable all debugging output classes. It takes a bitmask, so
1599 to enable more than one output class, just add their values.
1600
1601 ============= ======================================
1602 Debug bitmask Description
1603 ============= ======================================
1604 0x8000 Disclose PID of userspace programs
1605 accessing some functions of the driver
1606 0x0001 Initialization and probing
1607 0x0002 Removal
1608 0x0004 RF Transmitter control (RFKILL)
1609 (bluetooth, WWAN, UWB...)
1610 0x0008 HKEY event interface, hotkeys
1611 0x0010 Fan control
1612 0x0020 Backlight brightness
1613 0x0040 Audio mixer/volume control
1614 ============= ======================================
1615
1616 There is also a kernel build option to enable more debugging
1617 information, which may be necessary to debug driver problems.
1618
1619 The level of debugging information output by the driver can be changed
1620 at runtime through sysfs, using the driver attribute debug_level. The
1621 attribute takes the same bitmask as the debug module parameter above.
1622
1623
1624 Force loading of module
1625 -----------------------
1626
1627 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1628 the module parameter force_load=1. Regardless of whether this works or
1629 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1630
1631
1632 Sysfs interface changelog
1633 ^^^^^^^^^^^^^^^^^^^^^^^^^
1634
1635 ========= ===============================================================
1636 0x000100: Initial sysfs support, as a single platform driver and
1637 device.
1638 0x000200: Hot key support for 32 hot keys, and radio slider switch
1639 support.
1640 0x010000: Hot keys are now handled by default over the input
1641 layer, the radio switch generates input event EV_RADIO,
1642 and the driver enables hot key handling by default in
1643 the firmware.
1644
1645 0x020000: ABI fix: added a separate hwmon platform device and
1646 driver, which must be located by name (thinkpad)
1647 and the hwmon class for libsensors4 (lm-sensors 3)
1648 compatibility. Moved all hwmon attributes to this
1649 new platform device.
1650
1651 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1652 support. If you must, use it to know you should not
1653 start a userspace NVRAM poller (allows to detect when
1654 NVRAM is compiled out by the user because it is
1655 unneeded/undesired in the first place).
1656 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1657 and proper hotkey_mask semantics (version 8 of the
1658 NVRAM polling patch). Some development snapshots of
1659 0.18 had an earlier version that did strange things
1660 to hotkey_mask.
1661
1662 0x020200: Add poll()/select() support to the following attributes:
1663 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1664
1665 0x020300: hotkey enable/disable support removed, attributes
1666 hotkey_bios_enabled and hotkey_enable deprecated and
1667 marked for removal.
1668
1669 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1670 to not exist in a given model are not registered with
1671 the LED sysfs class anymore.
1672
1673 0x020500: Updated hotkey driver, hotkey_mask is always available
1674 and it is always able to disable hot keys. Very old
1675 thinkpads are properly supported. hotkey_bios_mask
1676 is deprecated and marked for removal.
1677
1678 0x020600: Marker for backlight change event support.
1679
1680 0x020700: Support for mute-only mixers.
1681 Volume control in read-only mode by default.
1682 Marker for ALSA mixer support.
1683
1684 0x030000: Thermal and fan sysfs attributes were moved to the hwmon
1685 device instead of being attached to the backing platform
1686 device.
1687 ========= ===============================================================
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