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Linux 6.18.37 · Administration / Laptops

ThinkPad ACPI Extras Driver

IBM·Lenovo ThinkPad의 hotkey, radio, display, LED, audio, thermal, fan, battery와 platform-specific sysfs interface를 설명합니다.

Source pathDocumentation/admin-guide/laptops/thinkpad-acpi.rst
Source versionLinux v6.18.37
TranslationDUJINLABS 전문 번역 + 해설

요약·해설과 원문, 전문 번역을 서로 분리했습니다. API 이름, symbol, source path는 원문 표기를 사용합니다.

1. 요약·해설

원문의 핵심 논리와 kernel programming 관점의 보충 설명입니다. 아래의 전문 번역과는 별도로 작성했습니다.

Driver와 interface

thinkpad-acpi.rst:1-182

driver 역사, 지원 기능, procfs·sysfs 위치와 interface version을 설명합니다.

Hotkey와 HKEY event

thinkpad-acpi.rst:183-619

event mask, input mapping, HKEY event table와 thermal alarm을 정리합니다.

Radio·display·LED·sensor

thinkpad-acpi.rst:620-1106

Bluetooth, video, ThinkLight, CMOS, LED, beep, temperature와 brightness를 설명합니다.

Audio와 fan

thinkpad-acpi.rst:1107-1380

Console Audio semantics, volume mode, fan level과 safety watchdog을 설명합니다.

현대 platform attribute와 changelog

thinkpad-acpi.rst:1381-1691

WWAN, PrivacyGuard, lap mode, UWB, keyboard·antenna·MAC·battery attribute와 sysfs changelog를 제공합니다.

2. 영어 원문 전체

번역 기준이 된 Linux v6.18.37 원문입니다. 줄 번호는 이 버전의 파일 좌표입니다.

원문 전체 펼치기
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 2024 platforms replaced by
449 0x131f (see below) and on newer
450 platforms (2025 +) keycode is
451 replaced by 0x1401 (see below).
452
453 0x1009 0x08 FN+F9 -
454
455 ... ... ... ...
456
457 0x100B 0x0A FN+F11 -
458
459 0x100C 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
469 0x100D 0x0C FN+BACKSPACE -
470 0x100E 0x0D FN+INSERT -
471 0x100F 0x0E FN+DELETE -
472
473 0x1010 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.
482 0x1011 0x10 FN+END Brightness down. See brightness
483 up for details.
484
485 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
486 always handled by the firmware,
487 even when unmasked.
488
489 0x1013 0x12 FN+PGDOWN -
490
491 0x1014 0x13 FN+SPACE Zoom key
492
493 0x1015 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.
498 0x1016 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.
503 0x1017 0x16 MUTE Mute internal mixer. This
504 key is always handled by the
505 firmware, even when unmasked.
506
507 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
508
509 0x1019 0x18 unknown
510
511 0x131f ... FN+F8 Platform Mode change (2024 systems).
512 Implemented in driver.
513
514 0x1401 ... FN+F8 Platform Mode change (2025 + systems).
515 Implemented in driver.
516 ... ... ...
517
518 0x1020 0x1F unknown
519 ======= ======= ============== ==============================================
520
521 The ThinkPad firmware does not allow one to differentiate when most hot
522 keys are pressed or released (either that, or we don't know how to, yet).
523 For these keys, the driver generates a set of events for a key press and
524 immediately issues the same set of events for a key release. It is
525 unknown by the driver if the ThinkPad firmware triggered these events on
526 hot key press or release, but the firmware will do it for either one, not
527 both.
528
529 If a key is mapped to KEY_RESERVED, it generates no input events at all.
530 If a key is mapped to KEY_UNKNOWN, it generates an input event that
531 includes an scan code. If a key is mapped to anything else, it will
532 generate input device EV_KEY events.
533
534 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
535 events for switches:
536
537 ============== ==============================================
538 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
539 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
540 ============== ==============================================
541
542 Non hotkey ACPI HKEY event map
543 ------------------------------
544
545 Events that are never propagated by the driver:
546
547 ====== ==================================================
548 0x2304 System is waking up from suspend to undock
549 0x2305 System is waking up from suspend to eject bay
550 0x2404 System is waking up from hibernation to undock
551 0x2405 System is waking up from hibernation to eject bay
552 0x5001 Lid closed
553 0x5002 Lid opened
554 0x5009 Tablet swivel: switched to tablet mode
555 0x500A Tablet swivel: switched to normal mode
556 0x5010 Brightness level changed/control event
557 0x6000 KEYBOARD: Numlock key pressed
558 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
559 0x7000 Radio Switch may have changed state
560 ====== ==================================================
561
562
563 Events that are propagated by the driver to userspace:
564
565 ====== =====================================================
566 0x2313 ALARM: System is waking up from suspend because
567 the battery is nearly empty
568 0x2413 ALARM: System is waking up from hibernation because
569 the battery is nearly empty
570 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
571 0x3006 Bay hotplug request (hint to power up SATA link when
572 the optical drive tray is ejected)
573 0x4003 Undocked (see 0x2x04), can sleep again
574 0x4010 Docked into hotplug port replicator (non-ACPI dock)
575 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
576 0x500B Tablet pen inserted into its storage bay
577 0x500C Tablet pen removed from its storage bay
578 0x6011 ALARM: battery is too hot
579 0x6012 ALARM: battery is extremely hot
580 0x6021 ALARM: a sensor is too hot
581 0x6022 ALARM: a sensor is extremely hot
582 0x6030 System thermal table changed
583 0x6032 Thermal Control command set completion (DYTC, Windows)
584 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
585 0x60C0 X1 Yoga 2016, Tablet mode status changed
586 0x60F0 Thermal Transformation changed (GMTS, Windows)
587 ====== =====================================================
588
589 Battery nearly empty alarms are a last resort attempt to get the
590 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
591 cleanly (0x2413) before power is lost. They must be acted upon, as the
592 wake up caused by the firmware will have negated most safety nets...
593
594 When any of the "too hot" alarms happen, according to Lenovo the user
595 should suspend or hibernate the laptop (and in the case of battery
596 alarms, unplug the AC adapter) to let it cool down. These alarms do
597 signal that something is wrong, they should never happen on normal
598 operating conditions.
599
600 The "extremely hot" alarms are emergencies. According to Lenovo, the
601 operating system is to force either an immediate suspend or hibernate
602 cycle, or a system shutdown. Obviously, something is very wrong if this
603 happens.
604
605
606 Brightness hotkey notes
607 ^^^^^^^^^^^^^^^^^^^^^^^
608
609 Don't mess with the brightness hotkeys in a Thinkpad. If you want
610 notifications for OSD, use the sysfs backlight class event support.
611
612 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
613 automatically for the cases were userspace has to do something to
614 implement brightness changes. When you override these events, you will
615 either fail to handle properly the ThinkPads that require explicit
616 action to change backlight brightness, or the ThinkPads that require
617 that no action be taken to work properly.
618
619
620 Bluetooth
621 ---------
622
623 procfs: /proc/acpi/ibm/bluetooth
624
625 sysfs device attribute: bluetooth_enable (deprecated)
626
627 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
628
629 This feature shows the presence and current state of a ThinkPad
630 Bluetooth device in the internal ThinkPad CDC slot.
631
632 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
633 so it is kept across reboots and power-off.
634
635 Procfs notes
636 ^^^^^^^^^^^^
637
638 If 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
643 Sysfs 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
663 Video output control -- /proc/acpi/ibm/video
664 --------------------------------------------
665
666 This feature allows control over the devices used for video output -
667 LCD, 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
680 NOTE:
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
685 Each video output device can be enabled or disabled individually.
686 Reading /proc/acpi/ibm/video shows the status of each device.
687
688 Automatic video switching can be enabled or disabled. When automatic
689 video switching is enabled, certain events (e.g. opening the lid,
690 docking or undocking) cause the video output device to change
691 automatically. While this can be useful, it also causes flickering
692 and, on the X40, video corruption. By disabling automatic switching,
693 the flickering or video corruption can be avoided.
694
695 The video_switch command cycles through the available video outputs
696 (it simulates the behavior of Fn-F7).
697
698 Video expansion can be toggled through this feature. This controls
699 whether the display is expanded to fill the entire LCD screen when a
700 mode with less than full resolution is used. Note that the current
701 video expansion status cannot be determined through this feature.
702
703 Note that on many models (particularly those using Radeon graphics
704 chips) the X driver configures the video card in a way which prevents
705 Fn-F7 from working. This also disables the video output switching
706 features of this driver, as it uses the same ACPI methods as
707 Fn-F7. Video switching on the console should still work.
708
709 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
710
711
712 ThinkLight control
713 ------------------
714
715 procfs: /proc/acpi/ibm/light
716
717 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
718
719 procfs notes
720 ^^^^^^^^^^^^
721
722 The ThinkLight status can be read and set through the procfs interface. A
723 few models which do not make the status available will show the ThinkLight
724 status as "unknown". The available commands are::
725
726 echo on > /proc/acpi/ibm/light
727 echo off > /proc/acpi/ibm/light
728
729 sysfs notes
730 ^^^^^^^^^^^
731
732 The ThinkLight sysfs interface is documented by the LED class
733 documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
734 is "tpacpi::thinklight".
735
736 Due to limitations in the sysfs LED class, if the status of the ThinkLight
737 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
738 It is impossible to know if the status returned through sysfs is valid.
739
740
741 CMOS/UCMS control
742 -----------------
743
744 procfs: /proc/acpi/ibm/cmos
745
746 sysfs device attribute: cmos_command
747
748 This feature is mostly used internally by the ACPI firmware to keep the legacy
749 CMOS NVRAM bits in sync with the current machine state, and to record this
750 state so that the ThinkPad will retain such settings across reboots.
751
752 Some of these commands actually perform actions in some ThinkPad models, but
753 this is expected to disappear more and more in newer models. As an example, in
754 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
755 real, but commands 0 to 2 don't control the mixer anymore (they have been
756 phased out) and just update the NVRAM.
757
758 The range of valid cmos command numbers is 0 to 21, but not all have an
759 effect and the behavior varies from model to model. Here is the behavior
760 on 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
773 The cmos command interface is prone to firmware split-brain problems, as
774 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
775 exported just as a debug tool.
776
777
778 LED control
779 -----------
780
781 procfs: /proc/acpi/ibm/led
782 sysfs attributes: as per LED class, see below for names
783
784 Some of the LED indicators can be controlled through this feature. On
785 some older ThinkPad models, it is possible to query the status of the
786 LED indicators as well. Newer ThinkPads cannot query the real status
787 of the LED indicators.
788
789 Because misuse of the LEDs could induce an unaware user to perform
790 dangerous actions (like undocking or ejecting a bay device while the
791 buses are still active), or mask an important alarm (such as a nearly
792 empty battery, or a broken battery), access to most LEDs is
793 restricted.
794
795 Unrestricted access to all LEDs requires that thinkpad-acpi be
796 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
797 Distributions must never enable this option. Individual users that
798 are aware of the consequences are welcome to enabling it.
799
800 Audio mute and microphone mute LEDs are supported, but currently not
801 visible to userspace. They are used by the snd-hda-intel audio driver.
802
803 procfs notes
804 ^^^^^^^^^^^^
805
806 The 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
812 The <LED number> range is 0 to 15. The set of LEDs that can be
813 controlled varies from model to model. Here is the common ThinkPad
814 mapping:
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
830 All of the above can be turned on and off and can be made to blink.
831
832 sysfs notes
833 ^^^^^^^^^^^
834
835 The ThinkPad LED sysfs interface is described in detail by the LED class
836 documentation, in Documentation/leds/leds-class.rst.
837
838 The 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
845 Due to limitations in the sysfs LED class, if the status of the LED
846 indicators cannot be read due to an error, thinkpad-acpi will report it as
847 a brightness of zero (same as LED off).
848
849 If the thinkpad firmware doesn't support reading the current status,
850 trying to read the current LED brightness will just return whatever
851 brightness was last written to that attribute.
852
853 These LEDs can blink using hardware acceleration. To request that a
854 ThinkPad indicator LED should blink in hardware accelerated mode, use the
855 "timer" trigger, and leave the delay_on and delay_off parameters set to
856 zero (to request hardware acceleration autodetection).
857
858 LEDs that are known not to exist in a given ThinkPad model are not
859 made available through the sysfs interface. If you have a dock and you
860 notice there are LEDs listed for your ThinkPad that do not exist (and
861 are not in the dock), or if you notice that there are missing LEDs,
862 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
863
864
865 ACPI sounds -- /proc/acpi/ibm/beep
866 ----------------------------------
867
868 The BEEP method is used internally by the ACPI firmware to provide
869 audible alerts in various situations. This feature allows the same
870 sounds to be triggered manually.
871
872 The commands are non-negative integer numbers::
873
874 echo <number> >/proc/acpi/ibm/beep
875
876 The valid <number> range is 0 to 17. Not all numbers trigger sounds
877 and the sounds vary from model to model. Here is the behavior on the
878 X40:
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
895 Temperature sensors
896 -------------------
897
898 procfs: /proc/acpi/ibm/thermal
899
900 sysfs device attributes: (hwmon "thinkpad") temp*_input
901
902 Most ThinkPads include six or more separate temperature sensors but only
903 expose the CPU temperature through the standard ACPI methods. This
904 feature shows readings from up to eight different sensors on older
905 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
906
907 For example, on the X40, a typical output may be:
908
909 temperatures:
910 42 42 45 41 36 -128 33 -128
911
912 On the T43/p, a typical output may be:
913
914 temperatures:
915 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
916
917 The mapping of thermal sensors to physical locations varies depending on
918 system-board model (and thus, on ThinkPad model).
919
920 https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
921 tries to track down these locations for various models.
922
923 Most (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
935 For the R51 (source: Thomas Gruber):
936
937 - 2: Mini-PCI
938 - 3: Internal HDD
939
940 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
941 https://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
950 The 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
963 Procfs notes
964 ^^^^^^^^^^^^
965
966 Readings from sensors that are not available return -128.
967 No commands can be written to this file.
968
969 Sysfs 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
980 EXPERIMENTAL: Embedded controller register dump
981 -----------------------------------------------
982
983 This feature is not included in the thinkpad driver anymore.
984 Instead the EC can be accessed through /sys/kernel/debug/ec with
985 a userspace tool which can be found here:
986 ftp://ftp.suse.com/pub/people/trenn/sources/ec
987
988 Use it to determine the register holding the fan
989 speed 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
995 Often fan and temperature values vary between
996 readings. Since temperatures don't change vary fast, you can take
997 several quick dumps to eliminate them.
998
999 You can use a similar method to figure out the meaning of other
1000 embedded controller registers - e.g. make sure nothing else changes
1001 except the charging or discharging battery to determine which
1002 registers contain the current battery capacity, etc. If you experiment
1003 with this, do send me your results (including some complete dumps with
1004 a description of the conditions when they were taken.)
1007 LCD brightness control
1008 ----------------------
1010 procfs: /proc/acpi/ibm/brightness
1012 sysfs backlight device "thinkpad_screen"
1014 This feature allows software control of the LCD brightness on ThinkPad
1015 models which don't have a hardware brightness slider.
1017 It has some limitations: the LCD backlight cannot be actually turned
1018 on or off by this interface, it just controls the backlight brightness
1019 level.
1021 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1022 has eight brightness levels, ranging from 0 to 7. Some of the levels
1023 may not be distinct. Later Lenovo models that implement the ACPI
1024 display backlight brightness control methods have 16 levels, ranging
1025 from 0 to 15.
1027 For IBM ThinkPads, there are two interfaces to the firmware for direct
1028 brightness control, EC and UCMS (or CMOS). To select which one should be
1029 used, use the brightness_mode module parameter: brightness_mode=1 selects
1030 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1031 mode with NVRAM backing (so that brightness changes are remembered across
1032 shutdown/reboot).
1034 The driver tries to select which interface to use from a table of
1035 defaults for each ThinkPad model. If it makes a wrong choice, please
1036 report this as a bug, so that we can fix it.
1038 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1040 When display backlight brightness controls are available through the
1041 standard ACPI interface, it is best to use it instead of this direct
1042 ThinkPad-specific interface. The driver will disable its native
1043 backlight brightness control interface if it detects that the standard
1044 ACPI interface is available in the ThinkPad.
1046 If you want to use the thinkpad-acpi backlight brightness control
1047 instead of the generic ACPI video backlight brightness control for some
1048 reason, you should use the acpi_backlight=vendor kernel parameter.
1050 The brightness_enable module parameter can be used to control whether
1051 the LCD brightness control feature will be enabled when available.
1052 brightness_enable=0 forces it to be disabled. brightness_enable=1
1053 forces it to be enabled when available, even if the standard ACPI
1054 interface is also available.
1056 Procfs notes
1057 ^^^^^^^^^^^^
1059 The available commands are::
1061 echo up >/proc/acpi/ibm/brightness
1062 echo down >/proc/acpi/ibm/brightness
1063 echo 'level <level>' >/proc/acpi/ibm/brightness
1065 Sysfs notes
1066 ^^^^^^^^^^^
1068 The interface is implemented through the backlight sysfs class, which is
1069 poorly documented at this time.
1071 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1072 it there will be the following attributes:
1074 max_brightness:
1075 Reads the maximum brightness the hardware can be set to.
1076 The minimum is always zero.
1078 actual_brightness:
1079 Reads what brightness the screen is set to at this instant.
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.
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.
1097 WARNING:
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.
1107 Volume control (Console Audio control)
1108 --------------------------------------
1110 procfs: /proc/acpi/ibm/volume
1112 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1114 NOTE: by default, the volume control interface operates in read-only
1115 mode, as it is supposed to be used for on-screen-display purposes.
1116 The read/write mode can be enabled through the use of the
1117 "volume_control=1" module parameter.
1119 NOTE: distros are urged to not enable volume_control by default, this
1120 should be done by the local admin only. The ThinkPad UI is for the
1121 console audio control to be done through the volume keys only, and for
1122 the desktop environment to just provide on-screen-display feedback.
1123 Software volume control should be done only in the main AC97/HDA
1124 mixer.
1127 About the ThinkPad Console Audio control
1128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1130 ThinkPads have a built-in amplifier and muting circuit that drives the
1131 console headphone and speakers. This circuit is after the main AC97
1132 or HDA mixer in the audio path, and under exclusive control of the
1133 firmware.
1135 ThinkPads have three special hotkeys to interact with the console
1136 audio control: volume up, volume down and mute.
1138 It is worth noting that the normal way the mute function works (on
1139 ThinkPads that do not have a "mute LED") is:
1141 1. 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.
1144 2. Press either volume key to unmute the ThinkPad (it will _not_
1145 change the volume, it will just unmute).
1147 This is a very superior design when compared to the cheap software-only
1148 mute-toggle solution found on normal consumer laptops: you can be
1149 absolutely sure the ThinkPad will not make noise if you press the mute
1150 button, no matter the previous state.
1152 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1153 amplifiers driving the speakers and headphone output, and the firmware
1154 also handles volume control for the headphone and speakers on these
1155 ThinkPads without any help from the operating system (this volume
1156 control stage exists after the main AC97 or HDA mixer in the audio
1157 path).
1159 The newer Lenovo models only have firmware mute control, and depend on
1160 the main HDA mixer to do volume control (which is done by the operating
1161 system). In this case, the volume keys are filtered out for unmute
1162 key press (there are some firmware bugs in this area) and delivered as
1163 normal key presses to the operating system (thinkpad-acpi is not
1164 involved).
1167 The ThinkPad-ACPI volume control
1168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1170 The preferred way to interact with the Console Audio control is the
1171 ALSA interface.
1173 The legacy procfs interface allows one to read the current state,
1174 and if volume control is enabled, accepts the following commands::
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
1182 The <level> number range is 0 to 14 although not all of them may be
1183 distinct. To unmute the volume after the mute command, use either the
1184 up or down command (the level command will not unmute the volume), or
1185 the unmute command.
1187 You can use the volume_capabilities parameter to tell the driver
1188 whether your thinkpad has volume control or mute-only control:
1189 volume_capabilities=1 for mixers with mute and volume control,
1190 volume_capabilities=2 for mixers with only mute control.
1192 If the driver misdetects the capabilities for your ThinkPad model,
1193 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1194 can update the driver.
1196 There are two strategies for volume control. To select which one
1197 should be used, use the volume_mode module parameter: volume_mode=1
1198 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1199 (so that volume/mute changes are remembered across shutdown/reboot).
1201 The driver will operate in volume_mode=3 by default. If that does not
1202 work well on your ThinkPad model, please report this to
1203 ibm-acpi-devel@lists.sourceforge.net.
1205 The driver supports the standard ALSA module parameters. If the ALSA
1206 mixer is disabled, the driver will disable all volume functionality.
1209 Fan control and monitoring: fan speed, fan enable/disable
1210 ---------------------------------------------------------
1212 procfs: /proc/acpi/ibm/fan
1214 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1216 sysfs hwmon driver attributes: fan_watchdog
1218 NOTE 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.
1223 This feature attempts to show the current fan speed, control mode and
1224 other fan data that might be available. The speed is read directly
1225 from the hardware registers of the embedded controller. This is known
1226 to work on later R, T, X and Z series ThinkPads but may show a bogus
1227 value on other models.
1229 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1230 controlled separately, it shares the main fan control.
1232 Fan levels
1233 ^^^^^^^^^^
1235 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1236 stops the fan. The higher the level, the higher the fan speed, although
1237 adjacent levels often map to the same fan speed. 7 is the highest
1238 level, where the fan reaches the maximum recommended speed.
1240 Level "auto" means the EC changes the fan level according to some
1241 internal algorithm, usually based on readings from the thermal sensors.
1243 There is also a "full-speed" level, also known as "disengaged" level.
1244 In this level, the EC disables the speed-locked closed-loop fan control,
1245 and drives the fan as fast as it can go, which might exceed hardware
1246 limits, so use this level with caution.
1248 The fan usually ramps up or down slowly from one speed to another, and
1249 it is normal for the EC to take several seconds to react to fan
1250 commands. The full-speed level may take up to two minutes to ramp up to
1251 maximum speed, and in some ThinkPads, the tachometer readings go stale
1252 while the EC is transitioning to the full-speed level.
1254 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1255 monitoring all of the temperature sensor readings and you are ready to
1256 enable it if necessary to avoid overheating.
1258 An enabled fan in level "auto" may stop spinning if the EC decides the
1259 ThinkPad is cool enough and doesn't need the extra airflow. This is
1260 normal, and the EC will spin the fan up if the various thermal readings
1261 rise too much.
1263 On the X40, this seems to depend on the CPU and HDD temperatures.
1264 Specifically, the fan is turned on when either the CPU temperature
1265 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1266 fan is turned off when the CPU temperature drops to 49 degrees and the
1267 HDD temperature drops to 41 degrees. These thresholds cannot
1268 currently be controlled.
1270 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1271 certain conditions are met. It will override any fan programming done
1272 through thinkpad-acpi.
1274 The thinkpad-acpi kernel driver can be programmed to revert the fan
1275 level to a safe setting if userspace does not issue one of the procfs
1276 fan commands: "enable", "disable", "level" or "watchdog", or if there
1277 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1278 set to 1, manual mode) within a configurable amount of time of up to
1279 120 seconds. This functionality is called fan safety watchdog.
1281 Note that the watchdog timer stops after it enables the fan. It will be
1282 rearmed again automatically (using the same interval) when one of the
1283 above mentioned fan commands is received. The fan watchdog is,
1284 therefore, not suitable to protect against fan mode changes made through
1285 means other than the "enable", "disable", and "level" procfs fan
1286 commands, or the hwmon fan control sysfs interface.
1288 Procfs notes
1289 ^^^^^^^^^^^^
1291 The fan may be enabled or disabled with the following commands::
1293 echo enable >/proc/acpi/ibm/fan
1294 echo disable >/proc/acpi/ibm/fan
1296 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1297 will try to place it in a safe level if it is too slow or disabled.
1299 The fan level can be controlled with the command::
1301 echo 'level <level>' > /proc/acpi/ibm/fan
1303 Where <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"
1305 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1306 "full-speed", and reports it as "disengaged" for backwards
1307 compatibility.
1309 On the X31 and X40 (and ONLY on those models), the fan speed can be
1310 controlled to a certain degree. Once the fan is running, it can be
1311 forced to run faster or slower with the following command::
1313 echo 'speed <speed>' > /proc/acpi/ibm/fan
1315 The sustainable range of fan speeds on the X40 appears to be from about
1316 3700 to about 7350. Values outside this range either do not have any
1317 effect or the fan speed eventually settles somewhere in that range. The
1318 fan cannot be stopped or started with this command. This functionality
1319 is incomplete, and not available through the sysfs interface.
1321 To program the safety watchdog, use the "watchdog" command::
1323 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1325 If you want to disable the watchdog, use 0 as the interval.
1327 Sysfs notes
1328 ^^^^^^^^^^^
1330 The sysfs interface follows the hwmon subsystem guidelines for the most
1331 part, and the exception is the fan safety watchdog.
1333 Writes to any of the sysfs attributes may return the EINVAL error if
1334 that operation is not supported in a given ThinkPad or if the parameter
1335 is out-of-bounds, and EPERM if it is forbidden. They may also return
1336 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1337 to the firmware).
1339 Features not yet implemented by the driver return ENOSYS.
1341 hwmon 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)
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.
1351 hwmon 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).
1356 This attribute only commands the fan if pmw1_enable is set to 1
1357 (manual PWM control).
1359 hwmon 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.
1365 hwmon 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.
1370 hwmon 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.
1374 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1376 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1377 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1378 would be the safest choice, though).
1381 WAN
1382 ---
1384 procfs: /proc/acpi/ibm/wan
1386 sysfs device attribute: wwan_enable (deprecated)
1388 sysfs rfkill class: switch "tpacpi_wwan_sw"
1390 This feature shows the presence and current state of the built-in
1391 Wireless WAN device.
1393 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1394 so it is kept across reboots and power-off.
1396 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1397 ThinkPad models which come with this module installed.
1399 Procfs notes
1400 ^^^^^^^^^^^^
1402 If the W-WAN card is installed, the following commands can be used::
1404 echo enable > /proc/acpi/ibm/wan
1405 echo disable > /proc/acpi/ibm/wan
1407 Sysfs notes
1408 ^^^^^^^^^^^
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.
1414 enable:
1415 - 0: disables WWAN card / WWAN card is disabled
1416 - 1: enables WWAN card / WWAN card is enabled.
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.
1422 rfkill controller switch "tpacpi_wwan_sw": refer to
1423 Documentation/driver-api/rfkill.rst for details.
1426 LCD Shadow control
1427 ------------------
1429 procfs: /proc/acpi/ibm/lcdshadow
1431 Some newer T480s and T490s ThinkPads provide a feature called
1432 PrivacyGuard. By turning this feature on, the usable vertical and
1433 horizontal viewing angles of the LCD can be limited (as if some privacy
1434 screen was applied manually in front of the display).
1436 procfs notes
1437 ^^^^^^^^^^^^
1439 The available commands are::
1441 echo '0' >/proc/acpi/ibm/lcdshadow
1442 echo '1' >/proc/acpi/ibm/lcdshadow
1444 The first command ensures the best viewing angle and the latter one turns
1445 on the feature, restricting the viewing angles.
1448 DYTC Lapmode sensor
1449 -------------------
1451 sysfs: dytc_lapmode
1453 Newer thinkpads and mobile workstations have the ability to determine if
1454 the device is in deskmode or lapmode. This feature is used by user space
1455 to decide if WWAN transmission can be increased to maximum power and is
1456 also useful for understanding the different thermal modes available as
1457 they differ between desk and lap mode.
1459 The property is read-only. If the platform doesn't have support the sysfs
1460 class is not created.
1462 EXPERIMENTAL: UWB
1463 -----------------
1465 This feature is considered EXPERIMENTAL because it has not been extensively
1466 tested and validated in various ThinkPad models yet. The feature may not
1467 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1468 the experimental=1 parameter when loading the module.
1470 sysfs rfkill class: switch "tpacpi_uwb_sw"
1472 This feature exports an rfkill controller for the UWB device, if one is
1473 present and enabled in the BIOS.
1475 Sysfs notes
1476 ^^^^^^^^^^^
1478 rfkill controller switch "tpacpi_uwb_sw": refer to
1479 Documentation/driver-api/rfkill.rst for details.
1482 Setting keyboard language
1483 -------------------------
1485 sysfs: keyboard_lang
1487 This feature is used to set keyboard language to ECFW using ASL interface.
1488 Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1489 ")" numeric keys, which are not displaying correctly, when keyboard language
1490 is other than "english". This is because the default keyboard language in ECFW
1491 is set as "english". Hence using this sysfs, user can set the correct keyboard
1492 language to ECFW and then these key's will work correctly.
1494 Example of command to set keyboard language is mentioned below::
1496 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1498 Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1499 cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1500 fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1501 nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden),
1502 tr(Turkey)
1504 WWAN Antenna type
1505 -----------------
1507 sysfs: wwan_antenna_type
1509 On some newer Thinkpads we need to set SAR value based on the antenna
1510 type. This interface will be used by userspace to get the antenna type
1511 and set the corresponding SAR value, as is required for FCC certification.
1513 The available commands are::
1515 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1517 Currently 2 antenna types are supported as mentioned below:
1518 - type a
1519 - type b
1521 The property is read-only. If the platform doesn't have support the sysfs
1522 class is not created.
1524 Auxmac
1525 ------
1527 sysfs: auxmac
1529 Some newer Thinkpads have a feature called MAC Address Pass-through. This
1530 feature is implemented by the system firmware to provide a system unique MAC,
1531 that can override a dock or USB ethernet dongle MAC, when connected to a
1532 network. This property enables user-space to easily determine the MAC address
1533 if the feature is enabled.
1535 The values of this auxiliary MAC are:
1537 cat /sys/devices/platform/thinkpad_acpi/auxmac
1539 If the feature is disabled, the value will be 'disabled'.
1541 This property is read-only.
1543 Adaptive keyboard
1544 -----------------
1546 sysfs device attribute: adaptive_kbd_mode
1548 This sysfs attribute controls the keyboard "face" that will be shown on the
1549 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1550 and set.
1552 - 0 = Home mode
1553 - 1 = Web-browser mode
1554 - 2 = Web-conference mode
1555 - 3 = Function mode
1556 - 4 = Layflat mode
1558 For more details about which buttons will appear depending on the mode, please
1559 review the laptop's user guide:
1560 https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf
1562 Battery charge control
1563 ----------------------
1565 sysfs attributes:
1566 /sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1568 These two attributes are created for those batteries that are supported by the
1569 driver. They enable the user to control the battery charge thresholds of the
1570 given battery. Both values may be read and set. `charge_control_start_threshold`
1571 accepts an integer between 0 and 99 (inclusive); this value represents a battery
1572 percentage level, below which charging will begin. `charge_control_end_threshold`
1573 accepts an integer between 1 and 100 (inclusive); this value represents a battery
1574 percentage level, above which charging will stop.
1576 The exact semantics of the attributes may be found in
1577 Documentation/ABI/testing/sysfs-class-power.
1579 Multiple Commands, Module Parameters
1580 ------------------------------------
1582 Multiple commands can be written to the proc files in one shot by
1583 separating them with commas, for example::
1585 echo enable,0xffff > /proc/acpi/ibm/hotkey
1586 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1588 Commands can also be specified when loading the thinkpad-acpi module,
1589 for example::
1591 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1594 Enabling debugging output
1595 -------------------------
1597 The module takes a debug parameter which can be used to selectively
1598 enable various classes of debugging output, for example::
1600 modprobe thinkpad_acpi debug=0xffff
1602 will enable all debugging output classes. It takes a bitmask, so
1603 to enable more than one output class, just add their values.
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 ============= ======================================
1620 There is also a kernel build option to enable more debugging
1621 information, which may be necessary to debug driver problems.
1623 The level of debugging information output by the driver can be changed
1624 at runtime through sysfs, using the driver attribute debug_level. The
1625 attribute takes the same bitmask as the debug module parameter above.
1628 Force loading of module
1629 -----------------------
1631 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1632 the module parameter force_load=1. Regardless of whether this works or
1633 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1636 Sysfs interface changelog
1637 ^^^^^^^^^^^^^^^^^^^^^^^^^
1639 ========= ===============================================================
1640 0x000100: Initial sysfs support, as a single platform driver and
1641 device.
1642 0x000200: Hot key support for 32 hot keys, and radio slider switch
1643 support.
1644 0x010000: 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.
1649 0x020000: 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.
1655 0x020100: 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).
1660 0x020101: 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.
1666 0x020200: Add poll()/select() support to the following attributes:
1667 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1669 0x020300: hotkey enable/disable support removed, attributes
1670 hotkey_bios_enabled and hotkey_enable deprecated and
1671 marked for removal.
1673 0x020400: 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.
1677 0x020500: 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.
1682 0x020600: Marker for backlight change event support.
1684 0x020700: Support for mute-only mixers.
1685 Volume control in read-only mode by default.
1686 Marker for ALSA mixer support.
1688 0x030000: Thermal and fan sysfs attributes were moved to the hwmon
1689 device instead of being attached to the backing platform
1690 device.
1691 ========= ===============================================================

3. 한국어 전문 번역

영어 원문의 문단 순서와 의미를 유지한 전체 번역입니다. 코드, 함수명, symbol과 URL은 원문 표기를 유지합니다.

ThinkPad ACPI Extras driver 개요

1-31

Version 0.25, 2013년 10월 16일 문서입니다.

작성자는 Borislav Deianov <borislav@users.sf.net>와 Henrique de Moraes Holschuh <hmh@hmh.eng.br>입니다.

이 Linux driver는 IBM 및 Lenovo ThinkPad laptop을 위한 것입니다. ACPI와 ACPI EC framework를 통해 접근할 수 있지만 generic Linux ACPI driver가 충분히 지원하지 못하는 여러 기능을 제공합니다.

이 driver의 이름은 kernel 2.6.21 및 release 0.13-20070314까지 `ibm-acpi`였습니다. kernel 2.6.22와 release 0.14에서 `drivers/acpi`에서 `drivers/misc`로 이동하며 `thinkpad-acpi`로 바뀌었고, kernel 2.6.29와 release 0.22에서 다시 `drivers/platform/x86`으로 이동했습니다.

정식 driver 이름은 `thinkpad-acpi`입니다. userspace 문제 때문에 module 이름과 log message 등 일부 위치에서는 `thinkpad_acpi`를 사용합니다. 일부 Linux kernel version의 길이 제한 때문에 `thinkpad-acpi`가 너무 긴 곳에서는 `tpacpi`를 줄임말로 사용합니다.

지원 상태와 문제 보고

32-72

현재 지원 기능은 다음과 같습니다.

기능상태·범위
Fn key 조합지원
Bluetoothenable·disable
video outputswitching·expansion control
ThinkLighton·off
CMOS/UCMScontrol
LEDcontrol
ACPI soundcontrol
temperature sensormonitoring
embedded controller register dumpexperimental
LCD brightnesscontrol
volumecontrol
fanspeed monitoring·enable·disable
WANenable·disable
UWBenable·disable
LCD Shadow (PrivacyGuard)enable·disable
Lap mode sensor지원
keyboard language설정
WWAN Antenna type조회
Auxmac지원

model별 feature compatibility table은 `http://ibm-acpi.sf.net/`에서 관리합니다. 성공·실패 보고, 특히 표를 보완하거나 고치는 보고를 환영합니다.

보고에는 ThinkPad model name, `acpidump`로 얻은 ACPI table 사본, serial number와 UUID를 가린 `dmidecode` output, 동작하는 기능과 동작하지 않는 기능, 실패 기능에서 관찰한 동작을 포함하십시오. 그 밖의 comment와 patch도 환영합니다.

Kernel configuration

73-81

Linux kernel source에 포함된 driver를 compile할 때는 `CONFIG_THINKPAD_ACPI` Kconfig option을 찾으십시오. menu 경로는 `Device Drivers` -> `X86 Platform Specific Device Drivers` -> `ThinkPad ACPI Laptop Extras`입니다.

procfs·sysfs interface

82-136

driver는 기능 접근을 위해 userspace에 두 interface를 export합니다. 하나는 앞으로 제거될 legacy procfs interface이고, 다른 하나는 아직 완전하지 않은 새 sysfs interface입니다.

procfs interface는 `/proc/acpi/ibm` directory를 만들고 지원 기능마다 file 하나를 둡니다. 이 interface는 사실상 동결되어 거의 바뀌지 않으며 새 기능도 추가하지 않습니다. 앞으로의 새 기능은 sysfs interface에 구현합니다.

sysfs interface는 가능한 한 generic Linux sysfs subsystem과 class에 통합됩니다. 일부 subsystem이 아직 준비되거나 안정화되지 않았으므로 interface가 바뀔 수 있으며 모든 userspace program은 이를 처리해야 합니다.

procfs와 달리 sysfs interface와 통신할 때의 정확성, 그리고 thinkpad-acpi의 sysfs 구현 정확성을 엄격히 적용합니다. driver code 또는 구현의 bug는 interface를 호환되지 않게 바꿔야 하더라도 최대한 올바르게 고칩니다. kernel과 thinkpad-acpi 양쪽 interface가 성숙하면 이런 변경은 드물어질 것입니다.

application은 모든 sysfs guideline을 따르고 error를 정확히 처리해야 합니다. sysfs inode에 대한 file descriptor와 open/close operation도 올바르게 구현해야 합니다. thinkpad-acpi sysfs interface version은 아래 설명처럼 driver attribute로 export됩니다.

종류위치·탐색 방법
sysfs driver attributekernel 2.6.23 이상에서 `/sys/bus/platform/drivers/thinkpad_acpi/` 및 `/sys/bus/platform/drivers/thinkpad_hwmon/`
thinkpad_acpi device attributekernel 2.6.23 이상에서 `/sys/devices/platform/thinkpad_acpi/`
sensor·fan attribute`name` attribute가 `thinkpad`인 hwmon device를 찾거나, 더 바람직하게는 `libsensors`를 사용합니다.
kernel 4.14 이상 hwmon attribute`/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon?` 또는 `/sys/class/hwmon/hwmon?`

Driver·sysfs interface version

137-182

`/proc/acpi/ibm/driver`와 sysfs driver attribute `version`은 driver name과 version을 제공합니다. 이 file에는 command를 쓸 수 없습니다.

sysfs driver attribute `interface_version`은 thinkpad-acpi sysfs interface version을 unsigned long 값 `0xAAAABBCC` 형식의 16진수로 제공합니다.

field의미
AAAAmajor revision
BBminor revision
CCbugfix revision

driver의 sysfs interface changelog는 이 문서 끝에 있습니다. kernel subsystem이 수행한 sysfs 변경은 여기서 문서화하지 않으며 이 attribute로 추적하지도 않습니다.

thinkpad-acpi sysfs 변경은 Linux mainline에 제출된 시점부터만 non-experimental로 간주합니다. 그때 interface 변경을 문서화하고 필요하면 `interface_version`을 갱신합니다. mainline merge 전 기능은 사용자의 책임으로 사용해야 하며, merge될 때 없어지거나 호환되지 않는 방식으로 다시 구현될 수 있습니다.

새 attribute 추가처럼 본질적으로 backward-compatible인 변경은 항상 `interface_version`을 갱신하지는 않습니다. 따라서 특정 attribute가 없을 수 있음을 예상하고 올바르게 처리해야 합니다. attribute가 없다는 것은 해당 기능을 sysfs에서 제공하지 않는다는 유효한 표현입니다.

Hot key와 event mask

183-234

procfs interface는 `/proc/acpi/ibm/hotkey`, sysfs device attribute는 `hotkey_*`입니다. ThinkPad의 ACPI HKEY handler는 중요한 event와 keyboard hot key press를 OS에 전달합니다. thinkpad-acpi hotkey 기능을 enable하면 이런 driver가 존재함을 firmware에 알리고 여러 상황에서 firmware 동작을 바꿉니다.

driver는 load될 때 HKEY event reporting을 자동으로 enable하고 제거될 때 disable합니다. HKEY event는 다음 형식입니다.

ibm/hotkey HKEY 00000080 0000xxxx

이 event 중 일부만 hot key press입니다. driver는 hot key와 radio switch를 input layer로, 그 밖의 event를 ACPI netlink layer로 전달합니다. input layer는 각 hot key에 배정한 keycode를 remap하는 standard IOCTL을 지원합니다.

hot key bit mask로 어떤 key가 event를 만들지 일부 제어할 수 있습니다. mask에서 bit가 0인 `masked` key는 firmware가 처리합니다. bit가 설정된 `unmasked` key는 thinkpad-acpi가 처리하고 싶음을 firmware에 알리지만 firmware가 허용하지 않는 경우가 많습니다.

mask의 모든 bit를 바꿀 수 있는 것은 아니며, 바꿀 수 있는 bit도 항상 효과가 있는 것은 아닙니다. 모든 hot key를 개별 제어할 수도 없고 mask 자체를 지원하지 않는 model도 있어 동작은 model 의존적입니다.

driver는 unmasked hotkey를 filter합니다. firmware가 특정 hotkey를 disable하지 못하게 하더라도 driver는 unmasked hotkey event를 보고하지 않습니다. 일부 key를 unmask하면 기본 동작이 사라집니다. 예를 들어 Fn+F5를 unmask하면 firmware가 더는 그 key만으로 Bluetooth를 enable·disable하지 않습니다.

model과 firmware version에 따라 모든 Fn 조합이 ACPI를 통해 지원되지는 않습니다. 이런 ThinkPad에서는 `CMOS NVRAM`을 초당 최소 10회 polling해 일부 추가 hotkey를 지원할 수 있으며 driver는 필요할 때 자동으로 이 기능을 enable하려고 합니다.

Hot key procfs command

235-255

`/proc/acpi/ibm/hotkey`에는 다음 command를 쓸 수 있습니다.

echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
... any other 8-hex-digit mask ...
echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask

`0xffffffff`는 모든 hot key를 enable하고 `0`은 가능한 모든 hot key를 disable합니다. 다른 8자리 16진 mask도 사용할 수 있으며 `reset`은 권장 mask를 복원합니다.

다음 deprecated command는 kernel warning을 남깁니다.

echo enable > /proc/acpi/ibm/hotkey -- does nothing
echo disable > /proc/acpi/ibm/hotkey -- returns an error

`enable`은 아무 동작도 하지 않고 `disable`은 error를 반환합니다. procfs interface는 NVRAM polling control을 지원하지 않습니다. 최대한의 bug-for-bug compatibility를 유지하기 위해 mask를 전혀 지원하지 않는 firmware에서는 NVRAM polling을 사용 중이어도 mask를 보고하거나 조작하게 하지 않습니다.

Hot key sysfs attribute

256-368
attribute동작
hotkey_bios_enableddeprecated이며 곧 제거됩니다. 항상 `0`을 반환합니다.
hotkey_bios_maskdeprecated이며 사용하지 않아야 합니다. module load 당시 mask를 반환하고 unload 때 이 값으로 복원합니다. mask를 지원하지 않던 오래된 firmware의 hotkey bit인 `0x80c`로 항상 고정됩니다.
hotkey_enabledeprecated이며 곧 제거됩니다. `0`을 쓰면 `-EPERM`, `1`을 쓰면 아무 동작도 하지 않습니다.
hotkey_maskhot key별 event reporting과 firmware에 따른 ACPI event 생성을 enable하는 bit mask입니다. 현재 상태를 읽고 수정할 수 있습니다.
hotkey_all_mask모든 지원 hot key의 reporting을 enable할 mask입니다. firmware가 어차피 처리하는 passive event를 정확히 알지 못한다면 쓰지 말고 `hotkey_recommended_mask`를 사용하십시오.
hotkey_recommended_maskfirmware가 항상 처리하는 key를 제외한 모든 지원 hot key reporting용 mask이며 `hotkey_mask`에 씁니다. driver 기본 mask입니다.
hotkey_source_maskdriver가 NVRAM에서 polling할 hot key를 고릅니다. ACPI firmware capability로 자동 감지하지만 runtime에 override할 수 있습니다. 설정된 key는 `hotkey_mask`에서도 enable된 경우 hotkey event로 보고됩니다. CMOS NVRAM polling으로 얻을 수 있는 key는 일부뿐입니다.
hotkey_poll_freqpolling frequency는 `0`부터 `25` Hz이며 엄격히 필요할 때만 polling합니다. `0`은 disable하므로 NVRAM polling이 필요한 key가 보고되지 않습니다. 너무 낮으면 반복 press를 하나로 보고하거나 놓칠 수 있으며 권장값은 `10Hz`입니다.
hotkey_radio_swhardware radio switch가 있으면 radio disable 위치에서 `0`, enable 위치에서 `1`입니다. `poll()`/`select()`를 지원합니다.
hotkey_tablet_modetablet capability가 있으면 normal mode에서 `0`, tablet mode에서 `1`입니다. `poll()`/`select()`를 지원합니다.
wakeup_reasonbay ejection 요청 때문에 wake-up하면 `1`, undock 요청이면 `2`, normal 또는 알 수 없는 이유면 `0`입니다. `poll()`/`select()`를 지원합니다.
wakeup_hotunplug_completeundock 또는 bay ejection 요청 때문에 깨어났고 요청을 성공적으로 완료했으면 `1`입니다. 사용자가 원하면 이 시점에 다시 sleep시킬 수 있습니다. HKEY event `0x4003`, `0x3003`을 참조하십시오. `poll()`/`select()`를 지원합니다.

NVRAM mode에서 volume up/down/mute key는 mixer 변화로 합성됩니다. ThinkPad mixer UI에서는 volume up 또는 down 한 번이 unmute도 수행합니다. ACPI event mode에서는 firmware가 이 event를 보고하며 동작은 firmware model뿐 아니라 firmware version과 `OSI(Linux)` 상태에 따라서도 달라질 수 있습니다.

Input layer event와 device 식별

369-400

hot key 하나는 input layer `EV_KEY` event 하나로 mapping되며, 뒤에 해당 key scan code를 담은 `EV_MSC` `MSC_SCAN` event가 올 수 있습니다. event block 끝에는 항상 `EV_SYN`을 생성합니다.

key 처리에 `EV_MSC` `MSC_SCAN`을 사용하지 마십시오. 이 event는 key remap 보조용이며 특히 `KEY_UNKNOWN` remap에 유용합니다.

ID field
BusBUS_HOST
vendor0x1014 (PCI_VENDOR_ID_IBM) 또는 0x17aa (PCI_VENDOR_ID_LENOVO)
product0x5054 ("TP")
version0x4101

keymap이 backward-compatible하게 바뀌면 version LSB가 증가합니다. 이 input device의 MSB는 항상 `0x41`이어야 합니다. 그렇지 않으면 이 절의 방식으로 device를 사용하지 마십시오. HDAPS 같은 다른 ThinkPad input device이거나 호환되지 않게 기능이 바뀐 device일 수 있습니다.

다른 기능을 위한 event type을 이 input device에 추가하는 것은 backward-compatible 변경으로 간주합니다.

Thinkpad-acpi hot key event map 0x4101

401-541
ACPI eventscan codekey설명
0x10010x00FN+F1-
0x10020x01FN+F2IBM: battery(드묾), Lenovo: screen lock
0x10030x02FN+F3여러 IBM model은 hot key가 disabled이거나 Fn+F3가 masked여도 항상 보고합니다. IBM: screen lock이며 부수 효과로 ThinkLight를 끄는 경우가 많습니다. Lenovo: battery.
0x10040x03FN+F4ACPI sleep button semantics의 sleep-to-RAM key입니다. hot key 또는 ACPI sleep button event 중 하나는 항상 생성됩니다. S3/S4 sleep cycle을 수행하거나 시간이 지날 때까지 firmware가 후속 press를 거부할 수 있습니다.
0x10050x04FN+F5radio key입니다. firmware가 제어하면 internal Bluetooth와 W-WAN card를 enable·disable하지만 WLAN에는 영향을 주지 않습니다. 실제로는 Bluetooth+W-WAN+WLAN 전체 radio on/off에 사용해야 합니다.
0x10060x05FN+F6-
0x10070x06FN+F7video output cycle이며 신뢰성이 model별로 다릅니다.
0x10080x07FN+F8IBM: screen expand toggle. Lenovo: UltraNav configuration 또는 screen expand toggle. 2024 platform에서는 `0x131f`, 2025 이후 platform에서는 `0x1401`로 대체됩니다.
0x10090x08FN+F9-
............
0x100B0x0AFN+F11-
0x100C0x0BFN+F12sleep-to-disk입니다. ACPI event나 hotkey event를 통해 userspace가 직접 처리해야 합니다. S3/S4 sleep cycle 또는 일정 시간이 지나기 전까지 firmware가 후속 press를 거부할 수 있습니다.
0x100D0x0CFN+BACKSPACE-
0x100E0x0DFN+INSERT-
0x100F0x0EFN+DELETE-
0x10100x0FFN+HOMEbrightness up. IBM ThinkPad에서는 unmask해도 firmware가 항상 처리하므로 건드리지 마십시오. 새 BIOS의 Lenovo ThinkPad에서는 ACPI OSI나 userspace가 처리해야 하며 driver가 올바르게 조정합니다.
0x10110x10FN+ENDbrightness down. brightness up 설명을 따릅니다.
0x10120x11FN+PGUPThinkLight toggle. unmask해도 firmware가 항상 처리합니다.
0x10130x12FN+PGDOWN-
0x10140x13FN+SPACEzoom key
0x10150x14VOLUME UPinternal mixer volume up. unmask해도 firmware가 항상 처리하지만 Lenovo에서 동작을 바꾸는 것으로 보입니다.
0x10160x15VOLUME DOWN원문 표에는 internal mixer volume up이라고 적혀 있습니다. unmask해도 firmware가 항상 처리하지만 Lenovo에서 동작을 바꾸는 것으로 보입니다.
0x10170x16MUTEinternal mixer mute. unmask해도 firmware가 항상 처리합니다.
0x10180x17THINKPADThinkPad/Access IBM/Lenovo key
0x10190x18unknown-
0x131f...FN+F82024 system의 Platform Mode change이며 driver에 구현되어 있습니다.
0x1401...FN+F82025 이후 system의 Platform Mode change이며 driver에 구현되어 있습니다.
............
0x10200x1Funknown-

대부분의 hot key는 press와 release를 firmware에서 구분할 수 없습니다. driver는 key press event set을 만든 직후 같은 set으로 key release를 즉시 발행합니다. firmware가 press에서 trigger했는지 release에서 trigger했는지는 driver가 알 수 없지만 둘 중 한쪽에서만 trigger합니다.

`KEY_RESERVED`로 mapping한 key는 input event를 만들지 않습니다. `KEY_UNKNOWN`은 scan code를 포함한 input event를 만들고, 그 밖의 mapping은 input device `EV_KEY` event를 만듭니다.

thinkpad-acpi는 `EV_KEY` 외에도 switch용 `EV_SW` event를 발행할 수 있습니다.

switch의미
SW_RFKILL_ALLT60 이후 hardware rfkill rocker switch
SW_TABLET_MODETablet ThinkPad HKEY event `0x5009`, `0x500A`

Non-hotkey ACPI HKEY event

542-605

driver가 절대 userspace로 전달하지 않는 event입니다.

event의미
0x2304undock을 위해 suspend에서 wake-up
0x2305bay eject를 위해 suspend에서 wake-up
0x2404undock을 위해 hibernation에서 wake-up
0x2405bay eject를 위해 hibernation에서 wake-up
0x5001lid closed
0x5002lid opened
0x5009tablet swivel: tablet mode로 전환
0x500Atablet swivel: normal mode로 전환
0x5010brightness level changed/control event
0x6000KEYBOARD: Numlock key press
0x6005KEYBOARD: Fn key press, 검증 필요
0x7000radio switch state가 바뀌었을 수 있음

driver가 userspace로 전달하는 event입니다.

event의미
0x2313ALARM: battery가 거의 비어 suspend에서 wake-up
0x2413ALARM: battery가 거의 비어 hibernation에서 wake-up
0x3003bay ejection(`0x2x05`) 완료, 다시 sleep 가능
0x3006bay hotplug 요청. optical drive tray eject 때 SATA link power-up hint
0x4003undock(`0x2x04`) 완료, 다시 sleep 가능
0x4010hotplug port replicator(non-ACPI dock)에 dock
0x4011hotplug port replicator(non-ACPI dock)에서 undock
0x500Btablet pen을 storage bay에 삽입
0x500Ctablet pen을 storage bay에서 제거
0x6011ALARM: battery가 너무 뜨거움
0x6012ALARM: battery가 극도로 뜨거움
0x6021ALARM: sensor가 너무 뜨거움
0x6022ALARM: sensor가 극도로 뜨거움
0x6030system thermal table 변경
0x6032Thermal Control command set 완료(DYTC, Windows)
0x6040Nvidia Optimus/AC adapter 관련, 검증 필요
0x60C0X1 Yoga 2016 tablet mode status 변경
0x60F0Thermal Transformation 변경(GMTS, Windows)

battery nearly empty alarm은 전원이 끊기기 전에 OS가 정상적으로 hibernate 또는 shutdown하도록 하는 최후 수단입니다. `0x2313`은 hibernate 또는 shutdown, `0x2413`은 shutdown을 요구합니다. firmware wake-up이 대부분의 safety net을 무효화하므로 반드시 처리해야 합니다.

Lenovo 지침에 따르면 `too hot` alarm이 발생하면 laptop을 suspend 또는 hibernate하고, battery alarm이면 AC adapter도 분리해 식혀야 합니다. 정상 동작에서는 발생하지 않아야 하므로 system에 문제가 있음을 뜻합니다.

`extremely hot` alarm은 emergency입니다. OS는 즉시 suspend, hibernate 또는 shutdown을 강제해야 합니다.

Brightness hotkey 주의 사항

606-619

ThinkPad brightness hotkey 동작을 임의로 바꾸지 마십시오. OSD notification이 필요하면 sysfs backlight class event support를 사용하십시오.

userspace가 brightness 변경을 구현해야 하는 경우 driver가 `KEY_BRIGHTNESS_UP`과 `KEY_BRIGHTNESS_DOWN`을 자동으로 발행합니다. 이 event를 override하면 backlight 변경에 명시적 action이 필요한 ThinkPad 또는 반대로 아무 action도 없어야 정상인 ThinkPad 중 한쪽을 잘못 처리하게 됩니다.

Bluetooth control

620-662

procfs는 `/proc/acpi/ibm/bluetooth`, deprecated sysfs device attribute는 `bluetooth_enable`, generic rfkill class switch는 `tpacpi_bluetooth_sw`입니다.

이 기능은 internal ThinkPad CDC slot의 Bluetooth device 존재 여부와 현재 상태를 보여 줍니다. ThinkPad가 지원하면 Bluetooth 상태를 NVRAM에 저장하므로 reboot와 power-off 뒤에도 유지됩니다.

Bluetooth가 설치되어 있으면 procfs에서 다음 command를 사용할 수 있습니다.

echo enable > /proc/acpi/ibm/bluetooth
echo disable > /proc/acpi/ibm/bluetooth

Bluetooth CDC card가 설치되어 있으면 `bluetooth_enable` thinkpad-acpi device attribute에서 enable·disable하고 현재 상태를 조회할 수 있습니다. `0`은 Bluetooth disable 상태이거나 disable command이고, `1`은 enable 상태이거나 enable command입니다.

이 sysfs attribute는 generic rfkill class로 대체되었고 deprecated입니다. 원문은 2010년에 제거할 예정이라고 설명합니다. 자세한 내용은 rfkill controller switch `tpacpi_bluetooth_sw`와 `Documentation/driver-api/rfkill.rst`를 참조하십시오.

Video output control

663-711

`/proc/acpi/ibm/video`는 가능한 경우 LCD, CRT, DVI video output device를 제어합니다.

echo lcd_enable > /proc/acpi/ibm/video
echo lcd_disable > /proc/acpi/ibm/video
echo crt_enable > /proc/acpi/ibm/video
echo crt_disable > /proc/acpi/ibm/video
echo dvi_enable > /proc/acpi/ibm/video
echo dvi_disable > /proc/acpi/ibm/video
echo auto_enable > /proc/acpi/ibm/video
echo auto_disable > /proc/acpi/ibm/video
echo expand_toggle > /proc/acpi/ibm/video
echo video_switch > /proc/acpi/ibm/video

안전상 이 기능은 `CAP_SYS_ADMIN` capability를 가진 process만 사용할 수 있습니다. 일부 X.org version과 심각하게 충돌해 crash를 일으킬 수 있기 때문입니다.

각 output device를 개별 enable·disable할 수 있고 `/proc/acpi/ibm/video`를 읽으면 상태가 표시됩니다. automatic video switching도 enable·disable할 수 있습니다. enable 상태에서는 lid open, dock, undock 같은 event가 output을 자동으로 바꿉니다. 유용할 수 있지만 flicker를 일으키고 X40에서는 video corruption도 발생하므로 automatic switching을 끄면 이를 피할 수 있습니다.

`video_switch`는 사용 가능한 output을 순환하며 Fn-F7 동작을 흉내 냅니다. video expansion toggle은 full resolution보다 작은 mode를 LCD 전체 화면에 맞게 확대할지 제어합니다. 이 interface로는 현재 expansion 상태를 알아낼 수 없습니다.

많은 model, 특히 Radeon graphics chip을 쓰는 model에서는 X driver가 video card를 설정하는 방식 때문에 Fn-F7이 동작하지 않습니다. 이 driver도 Fn-F7과 같은 ACPI method를 쓰므로 video output switching 기능이 함께 disable됩니다. console에서의 video switching은 계속 동작할 수 있습니다.

ThinkLight control

712-740

procfs는 `/proc/acpi/ibm/light`, sysfs는 LED class의 `tpacpi::thinklight` LED attribute를 사용합니다.

procfs에서 ThinkLight 상태를 읽고 설정할 수 있습니다. 상태를 제공하지 않는 일부 model은 `unknown`을 표시합니다.

echo on  > /proc/acpi/ibm/light
echo off > /proc/acpi/ibm/light

sysfs interface는 `Documentation/leds/leds-class.rst`의 LED class 문서를 따르며 LED 이름은 `tpacpi::thinklight`입니다. sysfs LED class 한계 때문에 상태를 읽을 수 없거나 알 수 없으면 thinkpad-acpi는 `off`로 보고하며, sysfs가 반환한 상태가 유효한지 알 방법은 없습니다.

CMOS/UCMS control

741-777

procfs는 `/proc/acpi/ibm/cmos`, sysfs device attribute는 `cmos_command`입니다. 주로 ACPI firmware가 legacy CMOS NVRAM bit를 현재 machine state와 동기화하고 reboot 뒤에도 설정을 유지하도록 상태를 기록하는 내부 기능입니다.

일부 ThinkPad model에서 command가 실제 action을 수행하지만 newer model일수록 이런 동작은 사라질 것으로 예상됩니다. T43과 X40에서 command `12`, `13`은 실제 ThinkLight를 제어하지만 `0`부터 `2`는 더 이상 mixer를 제어하지 않고 NVRAM만 갱신합니다.

유효한 CMOS command number 범위는 `0`부터 `21`이지만 모든 값이 효과를 내지는 않고 model별로 동작이 다릅니다. X40에서의 동작은 다음과 같으며 `tpb`는 ThinkPad Buttons utility입니다.

commandX40에서 관련된 동작
0Volume down key press
1Volume up key press
2Mute on key press
3Access IBM key press
4LCD brightness up key press
5LCD brightness down key press
11screen expansion toggle key press/function
12ThinkLight on
13ThinkLight off
14ThinkLight key press, ThinkLight toggle

newer ThinkPad에서 이 interface는 compatibility layer일 뿐이므로 firmware split-brain 문제가 생기기 쉽습니다. 사용하지 마십시오. debug tool로만 export됩니다.

LED control

778-864

procfs는 `/proc/acpi/ibm/led`, sysfs는 아래 이름의 LED class attribute입니다. 일부 LED indicator를 제어할 수 있으며 older ThinkPad에서는 상태 조회도 가능한 경우가 있지만 newer ThinkPad는 실제 상태를 조회할 수 없습니다.

LED 오용은 bus가 활성인데도 사용자가 undock하거나 bay device를 eject하게 만들고, nearly empty 또는 broken battery 같은 중요 alarm을 가릴 수 있으므로 대부분 LED 접근은 제한됩니다.

모든 LED에 제한 없이 접근하려면 `CONFIG_THINKPAD_ACPI_UNSAFE_LEDS`를 enable해 compile해야 합니다. distribution은 절대 이 option을 enable하면 안 됩니다. 결과를 이해하는 individual user만 사용할 수 있습니다.

audio mute와 microphone mute LED도 지원하지만 현재 userspace에는 보이지 않으며 `snd-hda-intel` audio driver가 사용합니다.

procfs command 형식은 다음과 같습니다.

echo '<LED number> on' >/proc/acpi/ibm/led
echo '<LED number> off' >/proc/acpi/ibm/led
echo '<LED number> blink' >/proc/acpi/ibm/led

`<LED number>` 범위는 `0`부터 `15`이며 제어 가능한 set은 model별로 다릅니다. 모든 항목은 on, off, blink로 설정할 수 있습니다.

LED number일반적인 ThinkPad mapping
0power
1battery (orange)
2battery (green)
3UltraBase/dock
4UltraBay
5UltraBase battery slot
6unknown
7standby
8dock status 1
9dock status 2
10, 11unknown
12thinkvantage
13, 14, 15unknown

sysfs 세부 동작은 `Documentation/leds/leds-class.rst`를 따릅니다. LED ID 0부터 12까지 이름은 순서대로 다음과 같습니다.

"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
"tpacpi::thinkvantage".

sysfs LED class 한계 때문에 error로 상태를 읽지 못하면 brightness `0`, 즉 LED off로 보고합니다. firmware가 current status read를 지원하지 않으면 마지막으로 attribute에 쓴 brightness를 그대로 반환합니다.

이 LED는 hardware acceleration으로 blink할 수 있습니다. ThinkPad indicator LED의 hardware-accelerated blink를 요청하려면 `timer` trigger를 사용하고 `delay_on`, `delay_off`를 `0`으로 두어 hardware acceleration autodetection을 요청하십시오.

특정 model에 존재하지 않는 것으로 알려진 LED는 sysfs에 만들지 않습니다. dock을 사용하는데 실제 ThinkPad나 dock에 없는 LED가 보이거나 있어야 할 LED가 빠졌다면 `ibm-acpi-devel@lists.sourceforge.net`으로 보고해 주십시오.

ACPI sound

865-894

`/proc/acpi/ibm/beep`는 ACPI firmware가 여러 상황의 audible alert에 내부적으로 쓰는 `BEEP` method를 수동으로 trigger합니다.

command는 음수가 아닌 정수입니다.

echo <number> >/proc/acpi/ibm/beep

유효 범위는 `0`부터 `17`이지만 모든 number가 sound를 내지는 않고 sound도 model별로 다릅니다. X40의 동작은 다음과 같습니다.

numberX40 sound
0진행 중인 sound 중지. 단 `16`은 `17`로 중지
2beep 두 번, pause, 세 번째 beep("low battery")
3single beep
4high 뒤 low-pitched beep("unable")
5single beep
6very high 뒤 high-pitched beep("AC/DC")
7high-pitched beep
9짧은 beep 세 번
10매우 긴 beep
12low-pitched beep
15high-pitched beep 세 번을 계속 반복, `0`으로 중지
16medium-pitched beep 한 번을 계속 반복, `17`로 중지
17`16` 중지

Temperature sensor

895-979

procfs는 `/proc/acpi/ibm/thermal`, hwmon `thinkpad`의 sysfs device attribute는 `temp*_input`입니다.

대부분 ThinkPad는 여섯 개 이상의 독립 temperature sensor를 포함하지만 standard ACPI method로는 CPU temperature만 노출합니다. 이 기능은 older ThinkPad에서 최대 8개, newer ThinkPad에서 최대 16개 sensor를 보여 줍니다.

X40의 일반적인 output 예입니다.

temperatures:
	42 42 45 41 36 -128 33 -128

T43/p의 일반적인 output 예입니다.

temperatures:
	48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128

thermal sensor와 physical location의 mapping은 system-board model, 따라서 ThinkPad model별로 다릅니다.

대부분의 newer model은 다음 pattern을 따르는 것으로 보입니다.

sensor일반적인 위치
1CPU
2model에 따라 다름
3model에 따라 다름
4GPU
5main battery main sensor
6bay battery main sensor
7main battery secondary sensor
8bay battery secondary sensor
9-15model에 따라 다름

R51 mapping은 Thomas Gruber가 제공했습니다.

sensorR51 위치
2Mini-PCI
3internal HDD

T43, T43/p mapping은 Shmidoax/Thinkwiki.org가 제공했습니다. 원문 참조는 `https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p`입니다.

sensorT43/T43p 위치
2system board left side, PCMCIA slot 근처. HDAPS temperature로 보고
3PCMCIA slot
9MCH(northbridge) to DRAM Bus
10clock-generator, mini-pci card, ICH(southbridge). Mini-PCI card 아래, touchpad 아래
11power regulator. system board underside, F2 key 아래

A31은 매우 비전형적인 thermal sensor layout입니다. Milos Popovic가 제공했으며 원문 참조는 `https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31`입니다.

sensorA31 위치
1CPU
2main battery main sensor
3power converter
4bay battery main sensor
5MCH(northbridge)
6PCMCIA/ambient
7main battery secondary sensor
8bay battery secondary sensor

procfs에서 사용할 수 없는 sensor는 `-128`을 반환하며 이 file에는 command를 쓸 수 없습니다.

sysfs에서 사용할 수 없는 sensor는 `ENXIO` error를 반환합니다. battery나 dock 내부 sensor처럼 hotplug 가능한 thermal sensor가 있으므로 이 상태는 runtime에 바뀔 수 있습니다. thinkpad-acpi thermal sensor는 hwmon subsystem으로 보고되며 `Documentation/hwmon`의 모든 guideline을 따릅니다.

Embedded controller register dump

980-1006

이 experimental 기능은 더 이상 thinkpad driver에 포함되지 않습니다. 대신 `/sys/kernel/debug/ec`에서 EC에 접근하며 userspace tool은 다음 위치에 있습니다.

일부 model에서 fan speed를 보관하는 register를 찾으려면 battery를 완전히 충전하고 fan이 동작 중인지 확인한 뒤 위 tool로 EC를 읽으십시오.

fan과 temperature 값은 read 사이에 자주 바뀝니다. temperature는 매우 빠르게 변하지 않으므로 짧은 시간에 여러 dump를 얻어 temperature register 후보를 제거할 수 있습니다.

같은 방법으로 다른 EC register 의미도 찾을 수 있습니다. 예를 들어 charging 또는 discharging battery 외에는 아무것도 바뀌지 않게 하고 current battery capacity가 들어 있는 register를 찾습니다. 실험했다면 조건 설명과 complete dump를 포함해 결과를 maintainer에게 보내십시오.

LCD brightness control

1007-1106

procfs는 `/proc/acpi/ibm/brightness`, sysfs backlight device는 `thinkpad_screen`입니다. hardware brightness slider가 없는 ThinkPad의 LCD brightness를 software로 제어합니다.

이 interface는 LCD backlight를 실제로 on/off할 수 없고 brightness level만 제어합니다. IBM과 초기 Lenovo ThinkPad는 `0`부터 `7`까지 8단계이며 일부 단계는 서로 구분되지 않을 수 있습니다. standard ACPI display backlight method를 구현한 후기 Lenovo model은 `0`부터 `15`까지 16단계입니다.

brightness_modeIBM ThinkPad firmware interface
1EC mode
2UCMS 또는 CMOS mode
3NVRAM backing을 사용하는 EC mode. shutdown/reboot 뒤에도 brightness 변경 유지

driver는 model별 default table에서 사용할 interface를 고릅니다. 잘못 선택한다면 table을 고칠 수 있도록 bug로 보고하십시오. Lenovo ThinkPad는 `brightness_mode=2`인 UCMS만 지원합니다.

standard ACPI interface가 display brightness control을 제공하면 이 ThinkPad-specific direct interface보다 standard interface를 사용하는 편이 좋습니다. driver는 standard interface를 감지하면 native backlight interface를 disable합니다.

generic ACPI video backlight 대신 thinkpad-acpi backlight를 사용해야 한다면 kernel parameter `acpi_backlight=vendor`를 사용하십시오. `brightness_enable=0`은 기능을 강제로 disable하고, `brightness_enable=1`은 standard ACPI interface가 있어도 가능할 때 enable합니다.

procfs command는 다음과 같습니다.

echo up   >/proc/acpi/ibm/brightness
echo down >/proc/acpi/ibm/brightness
echo 'level <level>' >/proc/acpi/ibm/brightness

sysfs interface는 backlight class로 구현됩니다. `/sys/class/backlight` 아래에서 `thinkpad_screen` device를 찾으십시오.

attribute동작
max_brightnesshardware가 설정할 수 있는 maximum brightness를 읽습니다. minimum은 항상 `0`입니다.
actual_brightness현재 screen에 실제 설정된 brightness를 읽습니다.
brightnesswrite는 지정한 값으로 brightness를 바꾸도록 요청합니다. read는 `power=0`이고 kernel power-management event로 dim되지 않았을 때 driver가 목표로 하는 brightness를 반환합니다.
power`0`은 display on입니다. `1`부터 `3`은 thinkpad-acpi가 backlight를 실제로 끌 수 없으므로 level `0`으로 dim합니다. kernel power-management event가 현재 level을 일시적으로 높여 display를 dim할 수 있습니다.

경고: thinkpad-acpi backlight-level interface와 Linux ACPI video driver가 제공하는 ACPI-based interface를 동시에 호출하지 마십시오. 두 interface가 충돌해 이상 동작을 일으키고 매 변경마다 level을 불필요하게 올렸다 내리면서 backlight lamp 수명을 줄일 수 있습니다.

ThinkPad Console Audio control

1107-1166

procfs는 `/proc/acpi/ibm/volume`이며 ALSA control 이름은 `ThinkPad Console Audio Control`, 기본 ID는 `ThinkPadEC`입니다.

기본적으로 volume interface는 OSD 용도의 read-only mode입니다. `volume_control=1` module parameter로 read/write mode를 enable할 수 있습니다. distribution은 이를 기본 enable하지 말아야 하며 local administrator만 설정해야 합니다.

ThinkPad UI는 console audio control을 volume key로만 수행하고 desktop environment는 OSD feedback만 제공하도록 설계되었습니다. software volume control은 main AC97/HDA mixer에서만 해야 합니다.

ThinkPad에는 console headphone과 speaker를 구동하는 amplifier와 mute circuit이 내장되어 있습니다. audio path에서 main AC97 또는 HDA mixer 뒤에 있으며 firmware가 독점 제어합니다. 이를 위한 special hotkey는 volume up, volume down, mute 세 개입니다.

mute LED가 없는 ThinkPad의 정상 mute 방식은 다음과 같습니다. mute key는 이전 상태와 무관하게 항상 mute하므로 여러 번 눌러도 계속 mute입니다. volume key 어느 쪽이든 한 번 누르면 volume을 바꾸지 않고 unmute만 합니다.

이 설계는 software-only mute toggle보다 확실합니다. 이전 상태와 무관하게 mute를 누르면 소리가 나지 않음을 보장할 수 있습니다.

IBM과 초기 Lenovo ThinkPad는 speaker와 headphone output을 위한 variable-gain amplifier를 가지며 firmware가 OS 도움 없이 volume을 제어합니다. 이 control stage도 main AC97/HDA mixer 뒤에 있습니다.

newer Lenovo model은 firmware mute control만 있고 volume은 OS가 main HDA mixer로 제어합니다. 이 경우 volume key는 unmute press를 위해 filter되고, firmware bug가 일부 있지만 정상 key press로 OS에 전달됩니다. thinkpad-acpi는 이 경로에 관여하지 않습니다.

ThinkPad-ACPI volume interface

1167-1208

Console Audio control과 상호작용하는 권장 방법은 ALSA interface입니다.

legacy procfs는 current state를 읽을 수 있고 volume control을 enable한 경우 다음 command를 받습니다.

echo up   >/proc/acpi/ibm/volume
echo down >/proc/acpi/ibm/volume
echo mute >/proc/acpi/ibm/volume
echo unmute >/proc/acpi/ibm/volume
echo 'level <level>' >/proc/acpi/ibm/volume

`<level>` 범위는 `0`부터 `14`이지만 모두 구분되지는 않을 수 있습니다. mute 뒤 unmute하려면 up, down 또는 unmute command를 사용하십시오. level command는 unmute하지 않습니다.

volume_capabilitieshardware control
1mute와 volume control이 있는 mixer
2mute-only control

driver가 model capability를 잘못 감지하면 `ibm-acpi-devel@lists.sourceforge.net`으로 보고해 table을 갱신할 수 있게 하십시오.

volume_mode전략
1EC mode
3NVRAM backing을 사용하는 EC mode. shutdown/reboot 뒤 volume·mute 변경 유지

기본값은 `volume_mode=3`입니다. model에서 잘 동작하지 않으면 보고하십시오. driver는 standard ALSA module parameter를 지원하며 ALSA mixer를 disable하면 모든 volume 기능도 disable합니다.

Fan level과 safety watchdog

1209-1287

procfs는 `/proc/acpi/ibm/fan`, hwmon `thinkpad` sysfs device attribute는 `fan1_input`, `pwm1`, `pwm1_enable`, `fan2_input`, hwmon driver attribute는 `fan_watchdog`입니다.

안전을 위해 fan control operation은 기본 disabled입니다. thinkpad-acpi에 `fan_control=1` module parameter를 제공해야 enable됩니다.

이 기능은 current fan speed, control mode와 가능한 fan data를 보여 줍니다. speed는 EC hardware register에서 직접 읽습니다. 후기 R, T, X, Z series에서는 동작한다고 알려졌지만 다른 model에서는 잘못된 값을 보일 수 있습니다. 일부 Lenovo ThinkPad의 secondary fan은 main fan control을 공유하므로 별도로 제어할 수 없습니다.

대부분 ThinkPad fan firmware interface는 level을 사용합니다. `0`은 stop이며 level이 높을수록 보통 speed가 높지만 인접 level이 같은 speed일 수 있습니다. `7`은 권장 maximum speed입니다. `auto`에서는 EC가 주로 thermal sensor read에 기반한 내부 algorithm으로 level을 바꿉니다.

`full-speed`, 즉 `disengaged` level은 EC의 speed-locked closed-loop control을 끄고 fan을 가능한 한 빠르게 구동합니다. hardware limit을 넘을 수 있으므로 주의해서 사용하십시오.

fan은 speed 사이를 천천히 ramp하며 EC가 command에 반응하는 데 몇 초 걸리는 것이 정상입니다. full-speed는 maximum까지 최대 2분이 걸릴 수 있고 일부 model에서는 전환 중 tachometer reading이 stale 상태가 됩니다.

경고: 모든 temperature sensor를 monitoring하고 overheating 방지를 위해 필요할 때 즉시 enable할 준비가 되어 있지 않다면 fan을 disabled 상태로 두지 마십시오.

`auto`의 enabled fan은 EC가 충분히 차갑다고 판단하면 멈출 수 있으며 정상입니다. thermal reading이 오르면 다시 회전합니다. X40에서는 CPU가 56도 또는 HDD가 46도에 도달하면 켜지고 CPU 49도 및 HDD 41도로 내려가면 꺼지는 것으로 보입니다. 현재 threshold를 제어할 수 없습니다.

ThinkPad ACPI DSDT code는 특정 조건에서 fan을 자체 재설정하며 thinkpad-acpi 설정을 override합니다.

fan safety watchdog은 userspace가 `enable`, `disable`, `level`, `watchdog` procfs command를 보내지 않거나, `pwm1_enable`에 write하지 않거나, manual mode에서 `pwm1` write가 없으면 최대 120초의 configurable timeout 뒤 safe level로 되돌릴 수 있습니다.

watchdog timer는 fan을 enable한 뒤 멈추고 위 command를 받으면 같은 interval로 자동 rearm됩니다. 따라서 procfs fan command나 hwmon sysfs interface 외의 수단으로 바꾼 fan mode를 보호하는 용도로는 적합하지 않습니다.

Fan procfs command

1288-1326

fan을 enable·disable하는 command입니다.

echo enable  >/proc/acpi/ibm/fan
echo disable >/proc/acpi/ibm/fan

fan level `0`은 disable과 같습니다. enable은 fan이 너무 느리거나 disabled이면 safe level로 두려고 합니다.

echo 'level <level>' > /proc/acpi/ibm/fan

`<level>`은 `0`부터 `7`, `auto`, `full-speed` 중 하나입니다. 모든 ThinkPad가 `auto`와 `full-speed`를 지원하지는 않습니다. driver는 `disengaged`를 `full-speed` alias로 받고 backward compatibility를 위해 `disengaged`로 보고합니다.

X31과 X40에서만 running fan speed를 어느 정도 빠르거나 느리게 강제할 수 있습니다.

echo 'speed <speed>' > /proc/acpi/ibm/fan

X40의 지속 가능한 범위는 약 `3700`부터 `7350`입니다. 범위 밖 값은 효과가 없거나 결국 범위 안 speed에 머뭅니다. 이 command로 fan을 start·stop할 수 없습니다. 기능은 불완전하며 sysfs에서는 제공하지 않습니다.

safety watchdog 설정 command입니다. interval `0`은 disable합니다.

echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan

Fan hwmon sysfs attribute

1327-1380

sysfs는 fan safety watchdog 예외를 제외하면 hwmon subsystem guideline을 따릅니다. 지원되지 않는 operation 또는 범위를 벗어난 parameter는 `EINVAL`, 금지된 operation은 `EPERM`, interrupted system call은 `EINTR`, firmware communication I/O error는 `EIO`를 반환할 수 있습니다. 미구현 기능은 `ENOSYS`입니다.

pwm1_enablemode
0PWM offline, fan을 full-speed mode로 설정
1manual PWM control. `pwm1`로 fan level 설정
2hardware PWM control, EC "auto" mode
3reserved. software PWM control은 아직 미구현

mode `0`, `2`는 모든 ThinkPad가 지원하지 않으며 driver가 항상 감지할 수 있는 것도 아닙니다. unsupported임을 알면 `-EINVAL`을 반환합니다.

attribute동작
pwm1firmware level `0-7`을 hwmon scale `0-255`로 변환합니다. `0`은 fan stop, `255`는 normal 최고 speed(level 7)입니다. `pwm1_enable=1`일 때만 fan에 command합니다. 원문에는 한 곳에 `pmw1_enable` typo가 있습니다.
fan1_inputfan tachometer RPM입니다. EC가 PWM offline으로 전환하는 최대 2분 동안 stale일 수 있고 older ThinkPad에서는 잘못된 값일 수 있습니다.
fan2_inputsecondary fan tachometer RPM입니다. 일부 ThinkPad에만 있고 fan이 설치되지 않으면 항상 `0`입니다.
fan_watchdogfan safety watchdog interval(초)입니다. minimum `1`, maximum `120`, `0`은 disable입니다.

fan을 멈추려면 `pwm1=0`, `pwm1_enable=1`로 설정하십시오. safe mode로 시작하려면 `pwm1_enable=2`를 설정합니다. `EINVAL`이면 `pwm1_enable=1`과 `pwm1>=128`을 시도하십시오. `255`가 가장 안전합니다.

Wireless WAN control

1381-1425

procfs는 `/proc/acpi/ibm/wan`, deprecated sysfs device attribute는 `wwan_enable`, rfkill class switch는 `tpacpi_wwan_sw`입니다. built-in Wireless WAN device의 존재와 current state를 표시합니다.

ThinkPad가 지원하면 WWAN state를 NVRAM에 저장해 reboot와 power-off 뒤에도 유지합니다. Lenovo ThinkPad X60에서 test했으며 module이 설치된 다른 model에서도 동작할 것으로 예상됩니다.

W-WAN card가 설치되어 있으면 다음 procfs command를 사용할 수 있습니다.

echo enable > /proc/acpi/ibm/wan
echo disable > /proc/acpi/ibm/wan

`wwan_enable`에서 card를 enable·disable하고 current status를 조회할 수 있습니다. `0`은 disable 상태 또는 disable command, `1`은 enable 상태 또는 enable command입니다.

이 interface는 generic rfkill class로 대체되어 deprecated이며 원문은 2010년에 제거할 예정이라고 설명합니다. `tpacpi_wwan_sw` 세부 사항은 `Documentation/driver-api/rfkill.rst`를 참조하십시오.

LCD Shadow PrivacyGuard

1426-1447

procfs는 `/proc/acpi/ibm/lcdshadow`입니다. 일부 newer T480s와 T490s의 PrivacyGuard는 display 앞에 privacy screen을 붙인 것처럼 LCD의 usable vertical·horizontal viewing angle을 제한합니다.

echo '0' >/proc/acpi/ibm/lcdshadow
echo '1' >/proc/acpi/ibm/lcdshadow

첫 command `0`은 가장 넓은 viewing angle을 보장하고, 두 번째 command `1`은 기능을 enable해 viewing angle을 제한합니다.

DYTC Lapmode sensor

1448-1461

read-only sysfs property는 `dytc_lapmode`입니다. newer ThinkPad와 mobile workstation은 device가 desk mode인지 lap mode인지 판단할 수 있습니다.

userspace는 이 값을 이용해 WWAN transmit power를 maximum으로 올려도 되는지 판단하며, desk와 lap mode에서 서로 다른 thermal mode를 이해하는 데도 사용합니다.

platform이 지원하지 않으면 sysfs class를 만들지 않습니다.

Experimental UWB rfkill

1462-1481

이 기능은 여러 ThinkPad model에서 충분히 test·validate되지 않아 experimental입니다. 예상대로 동작하지 않을 수 있으므로 주의해서 사용하십시오. module load 때 `experimental=1` parameter를 제공해야 합니다.

BIOS에서 UWB device가 존재하고 enable되어 있으면 rfkill controller `tpacpi_uwb_sw`를 export합니다. 자세한 내용은 `Documentation/driver-api/rfkill.rst`를 참조하십시오.

Keyboard language 설정

1482-1503

sysfs attribute `keyboard_lang`은 ASL interface로 ECFW의 keyboard language를 설정합니다. T580, T590, T15 Gen 1 등 일부 model에서 `=`, `(`, `)` numeric key가 English 이외 language일 때 올바르게 표시되지 않는 이유는 ECFW 기본 language가 English이기 때문입니다. 이 sysfs로 올바른 language를 설정하면 key가 정상 동작합니다.

Japanese layout 설정 예입니다.

      echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
sysfs textkeyboard layout
beBelgian
czCzech
daDanish
deGerman
enEnglish
esSpain
etEstonian
frFrench
fr-chFrench (Switzerland)
huHungarian
itItaly
jpJapan
nlDutch
nnNorway
plPolish
ptPortuguese
slSlovenian
svSweden
trTurkey

WWAN antenna type

1504-1523

read-only sysfs property는 `wwan_antenna_type`입니다. 일부 newer ThinkPad는 FCC certification 요구에 따라 antenna type별 SAR value를 설정해야 합니다. userspace가 antenna type을 읽고 해당 SAR value를 설정하는 데 이 interface를 사용합니다.

      cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type

현재 지원하는 antenna는 `type a`, `type b` 두 가지입니다. platform이 지원하지 않으면 sysfs class를 만들지 않습니다.

MAC Address Pass-through

1524-1542

read-only sysfs property는 `auxmac`입니다. 일부 newer ThinkPad의 MAC Address Pass-through는 system firmware가 system-unique MAC을 제공해 network 연결 시 dock 또는 USB Ethernet dongle MAC을 override하게 합니다.

userspace는 이 property로 기능이 enable된 경우 auxiliary MAC을 쉽게 확인할 수 있습니다.

      cat /sys/devices/platform/thinkpad_acpi/auxmac

기능이 disabled이면 값은 `disabled`입니다.

Adaptive keyboard mode

1543-1561

sysfs device attribute `adaptive_kbd_mode`는 Lenovo X1 Carbon 2nd gen(2014) adaptive keyboard에 표시할 keyboard face를 제어합니다. 값을 읽고 설정할 수 있습니다.

valuemode
0Home mode
1Web-browser mode
2Web-conference mode
3Function mode
4Layflat mode

mode별 표시 button은 laptop user guide를 참조하십시오.

Battery charge threshold

1562-1578

지원되는 battery에는 `/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold` 두 sysfs attribute가 생성됩니다. 둘 다 읽고 설정할 수 있습니다.

attributerange·semantics
charge_control_start_threshold`0`부터 `99` inclusive인 battery percentage입니다. battery level이 이 값 아래로 내려가면 charging을 시작합니다.
charge_control_end_threshold`1`부터 `100` inclusive인 battery percentage입니다. battery level이 이 값을 넘으면 charging을 멈춥니다.

정확한 semantics는 `Documentation/ABI/testing/sysfs-class-power`를 참조하십시오.

Multiple command와 module parameter

1579-1593

proc file에는 comma로 구분한 여러 command를 한 번에 쓸 수 있습니다.

echo enable,0xffff > /proc/acpi/ibm/hotkey
echo lcd_disable,crt_enable > /proc/acpi/ibm/video

thinkpad-acpi module load 때도 command를 지정할 수 있습니다.

modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable

Debug output

1594-1627

`debug` module parameter bitmask로 debugging output class를 선택적으로 enable합니다. 다음 예는 모든 class를 enable합니다.

 modprobe thinkpad_acpi debug=0xffff

여러 class를 enable하려면 bitmask 값을 더합니다.

debug bitmask설명
0x8000일부 driver function에 접근한 userspace program PID 공개
0x0001initialization과 probing
0x0002removal
0x0004RF transmitter control(RFKILL): Bluetooth, WWAN, UWB 등
0x0008HKEY event interface와 hotkey
0x0010fan control
0x0020backlight brightness
0x0040audio mixer/volume control

driver 문제 debug에 더 많은 정보가 필요하면 kernel build option도 사용할 수 있습니다. runtime에는 sysfs driver attribute `debug_level`에 같은 bitmask를 써서 output level을 바꿀 수 있습니다.

Module 강제 load

1628-1635

thinkpad-acpi가 ThinkPad 감지를 거부하면 module parameter `force_load=1`을 시도할 수 있습니다. 성공 여부와 관계없이 `ibm-acpi-devel@lists.sourceforge.net`으로 보고하십시오.

Sysfs interface changelog

1636-1691
interface version변경
0x000100single platform driver와 device로 initial sysfs support
0x00020032개 hot key와 radio slider switch 지원
0x010000hot key를 기본적으로 input layer에서 처리하고 radio switch가 `EV_RADIO` input event를 생성합니다. driver는 firmware hot key handling을 기본 enable합니다.
0x020000ABI fix. name `thinkpad`와 hwmon class로 찾아야 하는 별도 hwmon platform device·driver를 추가해 libsensors4(lm-sensors 3) compatibility를 제공하고 모든 hwmon attribute를 새 device로 이동했습니다.
0x020100hot key NVRAM polling support marker입니다. 꼭 필요할 때 userspace NVRAM poller를 시작하지 않아야 함을 판별하는 데 씁니다. user가 불필요하거나 원하지 않아 NVRAM을 compile-out한 경우도 구분할 수 있습니다.
0x020101hot key NVRAM polling과 올바른 `hotkey_mask` semantics marker(NVRAM polling patch version 8)입니다. 0.18 일부 development snapshot은 `hotkey_mask`에 비정상 동작을 하는 earlier version을 포함했습니다.
0x020200`hotkey_radio_sw`, `wakeup_hotunplug_complete`, `wakeup_reason`에 `poll()`/`select()` 지원 추가
0x020300hotkey enable/disable 지원 제거. `hotkey_bios_enabled`, `hotkey_enable` deprecated 및 제거 예정 표시
0x02040016 LED 지원 marker. model에 존재하지 않는 것으로 알려진 LED는 더 이상 LED sysfs class에 등록하지 않음
0x020500hotkey driver 갱신. `hotkey_mask`가 항상 있고 언제나 hot key를 disable할 수 있습니다. very old ThinkPad를 올바르게 지원하며 `hotkey_bios_mask`는 deprecated 및 제거 예정입니다.
0x020600backlight change event support marker
0x020700mute-only mixer 지원, volume control 기본 read-only mode, ALSA mixer support marker
0x030000thermal·fan sysfs attribute를 backing platform device에서 hwmon device로 이동