1 ===========================
2 ThinkPad ACPI Extras Driver
3 ===========================
9 - Borislav Deianov <borislav@users.sf.net>
10 - Henrique de Moraes Holschuh <hmh@hmh.eng.br>
12 http://ibm-acpi.sf.net/
14 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
15 supports various features of these laptops which are accessible
16 through the ACPI and ACPI EC framework, but not otherwise fully
17 supported by the generic Linux ACPI drivers.
19 This driver used to be named ibm-acpi until kernel 2.6.21 and release
20 0.13-20070314. It used to be in the drivers/acpi tree, but it was
21 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
22 2.6.22, and release 0.14. It was moved to drivers/platform/x86 for
23 kernel 2.6.29 and release 0.22.
25 The driver is named "thinkpad-acpi". In some places, like module
26 names and log messages, "thinkpad_acpi" is used because of userspace
29 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
30 long due to length limitations on some Linux kernel versions.
35 The features currently supported are the following (see below for
36 detailed description):
39 - Bluetooth enable and disable
40 - video output switching, expansion control
41 - ThinkLight on and off
46 - Experimental: embedded controller register dump
47 - LCD brightness control
49 - Fan control and monitoring: fan speed, fan enable/disable
50 - WAN enable and disable
51 - UWB enable and disable
52 - LCD Shadow (PrivacyGuard) enable and disable
54 - Setting keyboard language
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:
64 - a copy of your ACPI tables, using the "acpidump" utility
65 - a copy of the output of dmidecode, with serial numbers
67 - which driver features work and which don't
68 - the observed behavior of non-working features
70 Any other comments or patches are also more than welcome.
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".
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.
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.
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.
102 Notes about the sysfs interface
103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.
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.
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.
120 The version of thinkpad-acpi's sysfs interface is exported by the driver
121 as a driver attribute (see below).
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/
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/.
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?).
140 procfs: /proc/acpi/ibm/driver
142 sysfs driver attribute: version
144 The driver name and version. No commands can be written to this file.
147 Sysfs interface version
148 -----------------------
150 sysfs driver attribute: interface_version
152 Version of the thinkpad-acpi sysfs interface, as an unsigned long
153 (output in hex format: 0xAAAABBCC), where:
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
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.
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).
186 procfs: /proc/acpi/ibm/hotkey
188 sysfs device attribute: hotkey_*
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.
196 The driver enables the HKEY ("hot key") event reporting automatically
197 when loaded, and disables it when it is removed.
199 The driver will report HKEY events in the following format::
201 ibm/hotkey HKEY 00000080 0000xxxx
203 Some of these events refer to hot key presses, but not all of them.
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.
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!).
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.
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.
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.
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.
238 The following commands can be written to the /proc/acpi/ibm/hotkey file::
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
245 The following commands have been deprecated and will cause the kernel
248 echo enable > /proc/acpi/ibm/hotkey -- does nothing
249 echo disable > /proc/acpi/ibm/hotkey -- returns an error
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.
260 DEPRECATED, WILL BE REMOVED SOON.
265 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
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.
274 DEPRECATED, WILL BE REMOVED SOON.
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.
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.
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
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.
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.
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
322 frequency in Hz for hot key polling. It must be between
323 0 and 25 Hz. Polling is only carried out when strictly
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.
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.
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.
341 This attribute has poll()/select() support.
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.
348 This attribute has poll()/select() support.
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.
357 This attribute has poll()/select() support.
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
367 This attribute has poll()/select() support.
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
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.
381 The events are available in an input device, with the following id:
383 ============== ==============================
385 vendor 0x1014 (PCI_VENDOR_ID_IBM) or
386 0x17aa (PCI_VENDOR_ID_LENOVO)
387 product 0x5054 ("TP")
389 ============== ==============================
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.
398 Adding other event types for other functionalities shall be considered a
399 backwards-compatible change for this input device.
401 Thinkpad-acpi Hot Key event map (version 0x4101):
403 ======= ======= ============== ==============================================
406 ======= ======= ============== ==============================================
409 0x1002 0x01 FN+F2 IBM: battery (rare)
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
416 IBM: screen lock, often turns
417 off the ThinkLight as side-effect
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
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
436 Should be used to turn on/off all
437 radios (Bluetooth+W-WAN+WLAN),
442 0x1007 0x06 FN+F7 Video output cycle.
443 Do you feel lucky today?
445 0x1008 0x07 FN+F8 IBM: toggle screen expand
446 Lenovo: configure UltraNav,
447 or toggle screen expand
455 0x100C 0x0B FN+F12 Sleep to disk. You are always
456 supposed to handle it yourself,
457 either through the ACPI event,
458 or through a hotkey event.
459 The firmware may refuse to
460 generate further FN+F12 key
461 press events until a S3 or S4
462 ACPI sleep cycle is performed,
465 0x100D 0x0C FN+BACKSPACE -
466 0x100E 0x0D FN+INSERT -
467 0x100F 0x0E FN+DELETE -
469 0x1010 0x0F FN+HOME Brightness up. This key is
470 always handled by the firmware
471 in IBM ThinkPads, even when
472 unmasked. Just leave it alone.
473 For Lenovo ThinkPads with a new
474 BIOS, it has to be handled either
475 by the ACPI OSI, or by userspace.
476 The driver does the right thing,
477 never mess with this.
478 0x1011 0x10 FN+END Brightness down. See brightness
481 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
482 always handled by the firmware,
485 0x1013 0x12 FN+PGDOWN -
487 0x1014 0x13 FN+SPACE Zoom key
489 0x1015 0x14 VOLUME UP Internal mixer volume up. This
490 key is always handled by the
491 firmware, even when unmasked.
492 NOTE: Lenovo seems to be changing
494 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
495 key is always handled by the
496 firmware, even when unmasked.
497 NOTE: Lenovo seems to be changing
499 0x1017 0x16 MUTE Mute internal mixer. This
500 key is always handled by the
501 firmware, even when unmasked.
503 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
510 ======= ======= ============== ==============================================
512 The ThinkPad firmware does not allow one to differentiate when most hot
513 keys are pressed or released (either that, or we don't know how to, yet).
514 For these keys, the driver generates a set of events for a key press and
515 immediately issues the same set of events for a key release. It is
516 unknown by the driver if the ThinkPad firmware triggered these events on
517 hot key press or release, but the firmware will do it for either one, not
520 If a key is mapped to KEY_RESERVED, it generates no input events at all.
521 If a key is mapped to KEY_UNKNOWN, it generates an input event that
522 includes an scan code. If a key is mapped to anything else, it will
523 generate input device EV_KEY events.
525 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
528 ============== ==============================================
529 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
530 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
531 ============== ==============================================
533 Non hotkey ACPI HKEY event map
534 ------------------------------
536 Events that are never propagated by the driver:
538 ====== ==================================================
539 0x2304 System is waking up from suspend to undock
540 0x2305 System is waking up from suspend to eject bay
541 0x2404 System is waking up from hibernation to undock
542 0x2405 System is waking up from hibernation to eject bay
545 0x5009 Tablet swivel: switched to tablet mode
546 0x500A Tablet swivel: switched to normal mode
547 0x5010 Brightness level changed/control event
548 0x6000 KEYBOARD: Numlock key pressed
549 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
550 0x7000 Radio Switch may have changed state
551 ====== ==================================================
554 Events that are propagated by the driver to userspace:
556 ====== =====================================================
557 0x2313 ALARM: System is waking up from suspend because
558 the battery is nearly empty
559 0x2413 ALARM: System is waking up from hibernation because
560 the battery is nearly empty
561 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
562 0x3006 Bay hotplug request (hint to power up SATA link when
563 the optical drive tray is ejected)
564 0x4003 Undocked (see 0x2x04), can sleep again
565 0x4010 Docked into hotplug port replicator (non-ACPI dock)
566 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
567 0x500B Tablet pen inserted into its storage bay
568 0x500C Tablet pen removed from its storage bay
569 0x6011 ALARM: battery is too hot
570 0x6012 ALARM: battery is extremely hot
571 0x6021 ALARM: a sensor is too hot
572 0x6022 ALARM: a sensor is extremely hot
573 0x6030 System thermal table changed
574 0x6032 Thermal Control command set completion (DYTC, Windows)
575 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
576 0x60C0 X1 Yoga 2016, Tablet mode status changed
577 0x60F0 Thermal Transformation changed (GMTS, Windows)
578 ====== =====================================================
580 Battery nearly empty alarms are a last resort attempt to get the
581 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
582 cleanly (0x2413) before power is lost. They must be acted upon, as the
583 wake up caused by the firmware will have negated most safety nets...
585 When any of the "too hot" alarms happen, according to Lenovo the user
586 should suspend or hibernate the laptop (and in the case of battery
587 alarms, unplug the AC adapter) to let it cool down. These alarms do
588 signal that something is wrong, they should never happen on normal
589 operating conditions.
591 The "extremely hot" alarms are emergencies. According to Lenovo, the
592 operating system is to force either an immediate suspend or hibernate
593 cycle, or a system shutdown. Obviously, something is very wrong if this
597 Brightness hotkey notes
598 ^^^^^^^^^^^^^^^^^^^^^^^
600 Don't mess with the brightness hotkeys in a Thinkpad. If you want
601 notifications for OSD, use the sysfs backlight class event support.
603 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
604 automatically for the cases were userspace has to do something to
605 implement brightness changes. When you override these events, you will
606 either fail to handle properly the ThinkPads that require explicit
607 action to change backlight brightness, or the ThinkPads that require
608 that no action be taken to work properly.
614 procfs: /proc/acpi/ibm/bluetooth
616 sysfs device attribute: bluetooth_enable (deprecated)
618 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
620 This feature shows the presence and current state of a ThinkPad
621 Bluetooth device in the internal ThinkPad CDC slot.
623 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
624 so it is kept across reboots and power-off.
629 If Bluetooth is installed, the following commands can be used::
631 echo enable > /proc/acpi/ibm/bluetooth
632 echo disable > /proc/acpi/ibm/bluetooth
637 If the Bluetooth CDC card is installed, it can be enabled /
638 disabled through the "bluetooth_enable" thinkpad-acpi device
639 attribute, and its current status can also be queried.
643 - 0: disables Bluetooth / Bluetooth is disabled
644 - 1: enables Bluetooth / Bluetooth is enabled.
646 Note: this interface has been superseded by the generic rfkill
647 class. It has been deprecated, and it will be removed in year
650 rfkill controller switch "tpacpi_bluetooth_sw": refer to
651 Documentation/driver-api/rfkill.rst for details.
654 Video output control -- /proc/acpi/ibm/video
655 --------------------------------------------
657 This feature allows control over the devices used for video output -
658 LCD, CRT or DVI (if available). The following commands are available::
660 echo lcd_enable > /proc/acpi/ibm/video
661 echo lcd_disable > /proc/acpi/ibm/video
662 echo crt_enable > /proc/acpi/ibm/video
663 echo crt_disable > /proc/acpi/ibm/video
664 echo dvi_enable > /proc/acpi/ibm/video
665 echo dvi_disable > /proc/acpi/ibm/video
666 echo auto_enable > /proc/acpi/ibm/video
667 echo auto_disable > /proc/acpi/ibm/video
668 echo expand_toggle > /proc/acpi/ibm/video
669 echo video_switch > /proc/acpi/ibm/video
672 Access to this feature is restricted to processes owning the
673 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
674 enough with some versions of X.org to crash it.
676 Each video output device can be enabled or disabled individually.
677 Reading /proc/acpi/ibm/video shows the status of each device.
679 Automatic video switching can be enabled or disabled. When automatic
680 video switching is enabled, certain events (e.g. opening the lid,
681 docking or undocking) cause the video output device to change
682 automatically. While this can be useful, it also causes flickering
683 and, on the X40, video corruption. By disabling automatic switching,
684 the flickering or video corruption can be avoided.
686 The video_switch command cycles through the available video outputs
687 (it simulates the behavior of Fn-F7).
689 Video expansion can be toggled through this feature. This controls
690 whether the display is expanded to fill the entire LCD screen when a
691 mode with less than full resolution is used. Note that the current
692 video expansion status cannot be determined through this feature.
694 Note that on many models (particularly those using Radeon graphics
695 chips) the X driver configures the video card in a way which prevents
696 Fn-F7 from working. This also disables the video output switching
697 features of this driver, as it uses the same ACPI methods as
698 Fn-F7. Video switching on the console should still work.
700 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
706 procfs: /proc/acpi/ibm/light
708 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
713 The ThinkLight status can be read and set through the procfs interface. A
714 few models which do not make the status available will show the ThinkLight
715 status as "unknown". The available commands are::
717 echo on > /proc/acpi/ibm/light
718 echo off > /proc/acpi/ibm/light
723 The ThinkLight sysfs interface is documented by the LED class
724 documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
725 is "tpacpi::thinklight".
727 Due to limitations in the sysfs LED class, if the status of the ThinkLight
728 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
729 It is impossible to know if the status returned through sysfs is valid.
735 procfs: /proc/acpi/ibm/cmos
737 sysfs device attribute: cmos_command
739 This feature is mostly used internally by the ACPI firmware to keep the legacy
740 CMOS NVRAM bits in sync with the current machine state, and to record this
741 state so that the ThinkPad will retain such settings across reboots.
743 Some of these commands actually perform actions in some ThinkPad models, but
744 this is expected to disappear more and more in newer models. As an example, in
745 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
746 real, but commands 0 to 2 don't control the mixer anymore (they have been
747 phased out) and just update the NVRAM.
749 The range of valid cmos command numbers is 0 to 21, but not all have an
750 effect and the behavior varies from model to model. Here is the behavior
751 on the X40 (tpb is the ThinkPad Buttons utility):
753 - 0 - Related to "Volume down" key press
754 - 1 - Related to "Volume up" key press
755 - 2 - Related to "Mute on" key press
756 - 3 - Related to "Access IBM" key press
757 - 4 - Related to "LCD brightness up" key press
758 - 5 - Related to "LCD brightness down" key press
759 - 11 - Related to "toggle screen expansion" key press/function
760 - 12 - Related to "ThinkLight on"
761 - 13 - Related to "ThinkLight off"
762 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
764 The cmos command interface is prone to firmware split-brain problems, as
765 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
766 exported just as a debug tool.
772 procfs: /proc/acpi/ibm/led
773 sysfs attributes: as per LED class, see below for names
775 Some of the LED indicators can be controlled through this feature. On
776 some older ThinkPad models, it is possible to query the status of the
777 LED indicators as well. Newer ThinkPads cannot query the real status
778 of the LED indicators.
780 Because misuse of the LEDs could induce an unaware user to perform
781 dangerous actions (like undocking or ejecting a bay device while the
782 buses are still active), or mask an important alarm (such as a nearly
783 empty battery, or a broken battery), access to most LEDs is
786 Unrestricted access to all LEDs requires that thinkpad-acpi be
787 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
788 Distributions must never enable this option. Individual users that
789 are aware of the consequences are welcome to enabling it.
791 Audio mute and microphone mute LEDs are supported, but currently not
792 visible to userspace. They are used by the snd-hda-intel audio driver.
797 The available commands are::
799 echo '<LED number> on' >/proc/acpi/ibm/led
800 echo '<LED number> off' >/proc/acpi/ibm/led
801 echo '<LED number> blink' >/proc/acpi/ibm/led
803 The <LED number> range is 0 to 15. The set of LEDs that can be
804 controlled varies from model to model. Here is the common ThinkPad
808 - 1 - battery (orange)
809 - 2 - battery (green)
812 - 5 - UltraBase battery slot
819 - 13, 14, 15 - (unknown)
821 All of the above can be turned on and off and can be made to blink.
826 The ThinkPad LED sysfs interface is described in detail by the LED class
827 documentation, in Documentation/leds/leds-class.rst.
829 The LEDs are named (in LED ID order, from 0 to 12):
830 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
831 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
832 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
833 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
834 "tpacpi::thinkvantage".
836 Due to limitations in the sysfs LED class, if the status of the LED
837 indicators cannot be read due to an error, thinkpad-acpi will report it as
838 a brightness of zero (same as LED off).
840 If the thinkpad firmware doesn't support reading the current status,
841 trying to read the current LED brightness will just return whatever
842 brightness was last written to that attribute.
844 These LEDs can blink using hardware acceleration. To request that a
845 ThinkPad indicator LED should blink in hardware accelerated mode, use the
846 "timer" trigger, and leave the delay_on and delay_off parameters set to
847 zero (to request hardware acceleration autodetection).
849 LEDs that are known not to exist in a given ThinkPad model are not
850 made available through the sysfs interface. If you have a dock and you
851 notice there are LEDs listed for your ThinkPad that do not exist (and
852 are not in the dock), or if you notice that there are missing LEDs,
853 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
856 ACPI sounds -- /proc/acpi/ibm/beep
857 ----------------------------------
859 The BEEP method is used internally by the ACPI firmware to provide
860 audible alerts in various situations. This feature allows the same
861 sounds to be triggered manually.
863 The commands are non-negative integer numbers::
865 echo <number> >/proc/acpi/ibm/beep
867 The valid <number> range is 0 to 17. Not all numbers trigger sounds
868 and the sounds vary from model to model. Here is the behavior on the
871 - 0 - stop a sound in progress (but use 17 to stop 16)
872 - 2 - two beeps, pause, third beep ("low battery")
874 - 4 - high, followed by low-pitched beep ("unable")
876 - 6 - very high, followed by high-pitched beep ("AC/DC")
877 - 7 - high-pitched beep
878 - 9 - three short beeps
879 - 10 - very long beep
880 - 12 - low-pitched beep
881 - 15 - three high-pitched beeps repeating constantly, stop with 0
882 - 16 - one medium-pitched beep repeating constantly, stop with 17
889 procfs: /proc/acpi/ibm/thermal
891 sysfs device attributes: (hwmon "thinkpad") temp*_input
893 Most ThinkPads include six or more separate temperature sensors but only
894 expose the CPU temperature through the standard ACPI methods. This
895 feature shows readings from up to eight different sensors on older
896 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
898 For example, on the X40, a typical output may be:
901 42 42 45 41 36 -128 33 -128
903 On the T43/p, a typical output may be:
906 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
908 The mapping of thermal sensors to physical locations varies depending on
909 system-board model (and thus, on ThinkPad model).
911 https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
912 tries to track down these locations for various models.
914 Most (newer?) models seem to follow this pattern:
917 - 2: (depends on model)
918 - 3: (depends on model)
920 - 5: Main battery: main sensor
921 - 6: Bay battery: main sensor
922 - 7: Main battery: secondary sensor
923 - 8: Bay battery: secondary sensor
924 - 9-15: (depends on model)
926 For the R51 (source: Thomas Gruber):
931 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
932 https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
934 - 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
936 - 9: MCH (northbridge) to DRAM Bus
937 - 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
939 - 11: Power regulator, underside of system board, below F2 key
941 The A31 has a very atypical layout for the thermal sensors
942 (source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
945 - 2: Main Battery: main sensor
947 - 4: Bay Battery: main sensor
948 - 5: MCH (northbridge)
950 - 7: Main Battery: secondary sensor
951 - 8: Bay Battery: secondary sensor
957 Readings from sensors that are not available return -128.
958 No commands can be written to this file.
963 Sensors that are not available return the ENXIO error. This
964 status may change at runtime, as there are hotplug thermal
965 sensors, like those inside the batteries and docks.
967 thinkpad-acpi thermal sensors are reported through the hwmon
968 subsystem, and follow all of the hwmon guidelines at
971 EXPERIMENTAL: Embedded controller register dump
972 -----------------------------------------------
974 This feature is not included in the thinkpad driver anymore.
975 Instead the EC can be accessed through /sys/kernel/debug/ec with
976 a userspace tool which can be found here:
977 ftp://ftp.suse.com/pub/people/trenn/sources/ec
979 Use it to determine the register holding the fan
980 speed on some models. To do that, do the following:
982 - make sure the battery is fully charged
983 - make sure the fan is running
984 - use above mentioned tool to read out the EC
986 Often fan and temperature values vary between
987 readings. Since temperatures don't change vary fast, you can take
988 several quick dumps to eliminate them.
990 You can use a similar method to figure out the meaning of other
991 embedded controller registers - e.g. make sure nothing else changes
992 except the charging or discharging battery to determine which
993 registers contain the current battery capacity, etc. If you experiment
994 with this, do send me your results (including some complete dumps with
995 a description of the conditions when they were taken.)
998 LCD brightness control
999 ----------------------
1001 procfs: /proc/acpi/ibm/brightness
1003 sysfs backlight device "thinkpad_screen"
1005 This feature allows software control of the LCD brightness on ThinkPad
1006 models which don't have a hardware brightness slider.
1008 It has some limitations: the LCD backlight cannot be actually turned
1009 on or off by this interface, it just controls the backlight brightness
1012 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1013 has eight brightness levels, ranging from 0 to 7. Some of the levels
1014 may not be distinct. Later Lenovo models that implement the ACPI
1015 display backlight brightness control methods have 16 levels, ranging
1018 For IBM ThinkPads, there are two interfaces to the firmware for direct
1019 brightness control, EC and UCMS (or CMOS). To select which one should be
1020 used, use the brightness_mode module parameter: brightness_mode=1 selects
1021 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1022 mode with NVRAM backing (so that brightness changes are remembered across
1025 The driver tries to select which interface to use from a table of
1026 defaults for each ThinkPad model. If it makes a wrong choice, please
1027 report this as a bug, so that we can fix it.
1029 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1031 When display backlight brightness controls are available through the
1032 standard ACPI interface, it is best to use it instead of this direct
1033 ThinkPad-specific interface. The driver will disable its native
1034 backlight brightness control interface if it detects that the standard
1035 ACPI interface is available in the ThinkPad.
1037 If you want to use the thinkpad-acpi backlight brightness control
1038 instead of the generic ACPI video backlight brightness control for some
1039 reason, you should use the acpi_backlight=vendor kernel parameter.
1041 The brightness_enable module parameter can be used to control whether
1042 the LCD brightness control feature will be enabled when available.
1043 brightness_enable=0 forces it to be disabled. brightness_enable=1
1044 forces it to be enabled when available, even if the standard ACPI
1045 interface is also available.
1050 The available commands are::
1052 echo up >/proc/acpi/ibm/brightness
1053 echo down >/proc/acpi/ibm/brightness
1054 echo 'level <level>' >/proc/acpi/ibm/brightness
1059 The interface is implemented through the backlight sysfs class, which is
1060 poorly documented at this time.
1062 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1063 it there will be the following attributes:
1066 Reads the maximum brightness the hardware can be set to.
1067 The minimum is always zero.
1070 Reads what brightness the screen is set to at this instant.
1073 Writes request the driver to change brightness to the
1074 given value. Reads will tell you what brightness the
1075 driver is trying to set the display to when "power" is set
1076 to zero and the display has not been dimmed by a kernel
1077 power management event.
1080 power management mode, where 0 is "display on", and 1 to 3
1081 will dim the display backlight to brightness level 0
1082 because thinkpad-acpi cannot really turn the backlight
1083 off. Kernel power management events can temporarily
1084 increase the current power management level, i.e. they can
1090 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1091 interface and the ACPI-based backlight level change interface
1092 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1093 at the same time. The two will interact in bad ways, do funny things,
1094 and maybe reduce the life of the backlight lamps by needlessly kicking
1095 its level up and down at every change.
1098 Volume control (Console Audio control)
1099 --------------------------------------
1101 procfs: /proc/acpi/ibm/volume
1103 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1105 NOTE: by default, the volume control interface operates in read-only
1106 mode, as it is supposed to be used for on-screen-display purposes.
1107 The read/write mode can be enabled through the use of the
1108 "volume_control=1" module parameter.
1110 NOTE: distros are urged to not enable volume_control by default, this
1111 should be done by the local admin only. The ThinkPad UI is for the
1112 console audio control to be done through the volume keys only, and for
1113 the desktop environment to just provide on-screen-display feedback.
1114 Software volume control should be done only in the main AC97/HDA
1118 About the ThinkPad Console Audio control
1119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1121 ThinkPads have a built-in amplifier and muting circuit that drives the
1122 console headphone and speakers. This circuit is after the main AC97
1123 or HDA mixer in the audio path, and under exclusive control of the
1126 ThinkPads have three special hotkeys to interact with the console
1127 audio control: volume up, volume down and mute.
1129 It is worth noting that the normal way the mute function works (on
1130 ThinkPads that do not have a "mute LED") is:
1132 1. Press mute to mute. It will *always* mute, you can press it as
1133 many times as you want, and the sound will remain mute.
1135 2. Press either volume key to unmute the ThinkPad (it will _not_
1136 change the volume, it will just unmute).
1138 This is a very superior design when compared to the cheap software-only
1139 mute-toggle solution found on normal consumer laptops: you can be
1140 absolutely sure the ThinkPad will not make noise if you press the mute
1141 button, no matter the previous state.
1143 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1144 amplifiers driving the speakers and headphone output, and the firmware
1145 also handles volume control for the headphone and speakers on these
1146 ThinkPads without any help from the operating system (this volume
1147 control stage exists after the main AC97 or HDA mixer in the audio
1150 The newer Lenovo models only have firmware mute control, and depend on
1151 the main HDA mixer to do volume control (which is done by the operating
1152 system). In this case, the volume keys are filtered out for unmute
1153 key press (there are some firmware bugs in this area) and delivered as
1154 normal key presses to the operating system (thinkpad-acpi is not
1158 The ThinkPad-ACPI volume control
1159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1161 The preferred way to interact with the Console Audio control is the
1164 The legacy procfs interface allows one to read the current state,
1165 and if volume control is enabled, accepts the following commands::
1167 echo up >/proc/acpi/ibm/volume
1168 echo down >/proc/acpi/ibm/volume
1169 echo mute >/proc/acpi/ibm/volume
1170 echo unmute >/proc/acpi/ibm/volume
1171 echo 'level <level>' >/proc/acpi/ibm/volume
1173 The <level> number range is 0 to 14 although not all of them may be
1174 distinct. To unmute the volume after the mute command, use either the
1175 up or down command (the level command will not unmute the volume), or
1178 You can use the volume_capabilities parameter to tell the driver
1179 whether your thinkpad has volume control or mute-only control:
1180 volume_capabilities=1 for mixers with mute and volume control,
1181 volume_capabilities=2 for mixers with only mute control.
1183 If the driver misdetects the capabilities for your ThinkPad model,
1184 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1185 can update the driver.
1187 There are two strategies for volume control. To select which one
1188 should be used, use the volume_mode module parameter: volume_mode=1
1189 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1190 (so that volume/mute changes are remembered across shutdown/reboot).
1192 The driver will operate in volume_mode=3 by default. If that does not
1193 work well on your ThinkPad model, please report this to
1194 ibm-acpi-devel@lists.sourceforge.net.
1196 The driver supports the standard ALSA module parameters. If the ALSA
1197 mixer is disabled, the driver will disable all volume functionality.
1200 Fan control and monitoring: fan speed, fan enable/disable
1201 ---------------------------------------------------------
1203 procfs: /proc/acpi/ibm/fan
1205 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1207 sysfs hwmon driver attributes: fan_watchdog
1210 fan control operations are disabled by default for
1211 safety reasons. To enable them, the module parameter "fan_control=1"
1212 must be given to thinkpad-acpi.
1214 This feature attempts to show the current fan speed, control mode and
1215 other fan data that might be available. The speed is read directly
1216 from the hardware registers of the embedded controller. This is known
1217 to work on later R, T, X and Z series ThinkPads but may show a bogus
1218 value on other models.
1220 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1221 controlled separately, it shares the main fan control.
1226 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1227 stops the fan. The higher the level, the higher the fan speed, although
1228 adjacent levels often map to the same fan speed. 7 is the highest
1229 level, where the fan reaches the maximum recommended speed.
1231 Level "auto" means the EC changes the fan level according to some
1232 internal algorithm, usually based on readings from the thermal sensors.
1234 There is also a "full-speed" level, also known as "disengaged" level.
1235 In this level, the EC disables the speed-locked closed-loop fan control,
1236 and drives the fan as fast as it can go, which might exceed hardware
1237 limits, so use this level with caution.
1239 The fan usually ramps up or down slowly from one speed to another, and
1240 it is normal for the EC to take several seconds to react to fan
1241 commands. The full-speed level may take up to two minutes to ramp up to
1242 maximum speed, and in some ThinkPads, the tachometer readings go stale
1243 while the EC is transitioning to the full-speed level.
1245 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1246 monitoring all of the temperature sensor readings and you are ready to
1247 enable it if necessary to avoid overheating.
1249 An enabled fan in level "auto" may stop spinning if the EC decides the
1250 ThinkPad is cool enough and doesn't need the extra airflow. This is
1251 normal, and the EC will spin the fan up if the various thermal readings
1254 On the X40, this seems to depend on the CPU and HDD temperatures.
1255 Specifically, the fan is turned on when either the CPU temperature
1256 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1257 fan is turned off when the CPU temperature drops to 49 degrees and the
1258 HDD temperature drops to 41 degrees. These thresholds cannot
1259 currently be controlled.
1261 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1262 certain conditions are met. It will override any fan programming done
1263 through thinkpad-acpi.
1265 The thinkpad-acpi kernel driver can be programmed to revert the fan
1266 level to a safe setting if userspace does not issue one of the procfs
1267 fan commands: "enable", "disable", "level" or "watchdog", or if there
1268 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1269 set to 1, manual mode) within a configurable amount of time of up to
1270 120 seconds. This functionality is called fan safety watchdog.
1272 Note that the watchdog timer stops after it enables the fan. It will be
1273 rearmed again automatically (using the same interval) when one of the
1274 above mentioned fan commands is received. The fan watchdog is,
1275 therefore, not suitable to protect against fan mode changes made through
1276 means other than the "enable", "disable", and "level" procfs fan
1277 commands, or the hwmon fan control sysfs interface.
1282 The fan may be enabled or disabled with the following commands::
1284 echo enable >/proc/acpi/ibm/fan
1285 echo disable >/proc/acpi/ibm/fan
1287 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1288 will try to place it in a safe level if it is too slow or disabled.
1290 The fan level can be controlled with the command::
1292 echo 'level <level>' > /proc/acpi/ibm/fan
1294 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1295 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1296 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1297 "full-speed", and reports it as "disengaged" for backwards
1300 On the X31 and X40 (and ONLY on those models), the fan speed can be
1301 controlled to a certain degree. Once the fan is running, it can be
1302 forced to run faster or slower with the following command::
1304 echo 'speed <speed>' > /proc/acpi/ibm/fan
1306 The sustainable range of fan speeds on the X40 appears to be from about
1307 3700 to about 7350. Values outside this range either do not have any
1308 effect or the fan speed eventually settles somewhere in that range. The
1309 fan cannot be stopped or started with this command. This functionality
1310 is incomplete, and not available through the sysfs interface.
1312 To program the safety watchdog, use the "watchdog" command::
1314 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1316 If you want to disable the watchdog, use 0 as the interval.
1321 The sysfs interface follows the hwmon subsystem guidelines for the most
1322 part, and the exception is the fan safety watchdog.
1324 Writes to any of the sysfs attributes may return the EINVAL error if
1325 that operation is not supported in a given ThinkPad or if the parameter
1326 is out-of-bounds, and EPERM if it is forbidden. They may also return
1327 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1330 Features not yet implemented by the driver return ENOSYS.
1332 hwmon device attribute pwm1_enable:
1333 - 0: PWM offline (fan is set to full-speed mode)
1334 - 1: Manual PWM control (use pwm1 to set fan level)
1335 - 2: Hardware PWM control (EC "auto" mode)
1336 - 3: reserved (Software PWM control, not implemented yet)
1338 Modes 0 and 2 are not supported by all ThinkPads, and the
1339 driver is not always able to detect this. If it does know a
1340 mode is unsupported, it will return -EINVAL.
1342 hwmon device attribute pwm1:
1343 Fan level, scaled from the firmware values of 0-7 to the hwmon
1344 scale of 0-255. 0 means fan stopped, 255 means highest normal
1347 This attribute only commands the fan if pmw1_enable is set to 1
1348 (manual PWM control).
1350 hwmon device attribute fan1_input:
1351 Fan tachometer reading, in RPM. May go stale on certain
1352 ThinkPads while the EC transitions the PWM to offline mode,
1353 which can take up to two minutes. May return rubbish on older
1356 hwmon device attribute fan2_input:
1357 Fan tachometer reading, in RPM, for the secondary fan.
1358 Available only on some ThinkPads. If the secondary fan is
1359 not installed, will always read 0.
1361 hwmon driver attribute fan_watchdog:
1362 Fan safety watchdog timer interval, in seconds. Minimum is
1363 1 second, maximum is 120 seconds. 0 disables the watchdog.
1365 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1367 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1368 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1369 would be the safest choice, though).
1375 procfs: /proc/acpi/ibm/wan
1377 sysfs device attribute: wwan_enable (deprecated)
1379 sysfs rfkill class: switch "tpacpi_wwan_sw"
1381 This feature shows the presence and current state of the built-in
1382 Wireless WAN device.
1384 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1385 so it is kept across reboots and power-off.
1387 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1388 ThinkPad models which come with this module installed.
1393 If the W-WAN card is installed, the following commands can be used::
1395 echo enable > /proc/acpi/ibm/wan
1396 echo disable > /proc/acpi/ibm/wan
1401 If the W-WAN card is installed, it can be enabled /
1402 disabled through the "wwan_enable" thinkpad-acpi device
1403 attribute, and its current status can also be queried.
1406 - 0: disables WWAN card / WWAN card is disabled
1407 - 1: enables WWAN card / WWAN card is enabled.
1409 Note: this interface has been superseded by the generic rfkill
1410 class. It has been deprecated, and it will be removed in year
1413 rfkill controller switch "tpacpi_wwan_sw": refer to
1414 Documentation/driver-api/rfkill.rst for details.
1420 procfs: /proc/acpi/ibm/lcdshadow
1422 Some newer T480s and T490s ThinkPads provide a feature called
1423 PrivacyGuard. By turning this feature on, the usable vertical and
1424 horizontal viewing angles of the LCD can be limited (as if some privacy
1425 screen was applied manually in front of the display).
1430 The available commands are::
1432 echo '0' >/proc/acpi/ibm/lcdshadow
1433 echo '1' >/proc/acpi/ibm/lcdshadow
1435 The first command ensures the best viewing angle and the latter one turns
1436 on the feature, restricting the viewing angles.
1444 Newer thinkpads and mobile workstations have the ability to determine if
1445 the device is in deskmode or lapmode. This feature is used by user space
1446 to decide if WWAN transmission can be increased to maximum power and is
1447 also useful for understanding the different thermal modes available as
1448 they differ between desk and lap mode.
1450 The property is read-only. If the platform doesn't have support the sysfs
1451 class is not created.
1456 This feature is considered EXPERIMENTAL because it has not been extensively
1457 tested and validated in various ThinkPad models yet. The feature may not
1458 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1459 the experimental=1 parameter when loading the module.
1461 sysfs rfkill class: switch "tpacpi_uwb_sw"
1463 This feature exports an rfkill controller for the UWB device, if one is
1464 present and enabled in the BIOS.
1469 rfkill controller switch "tpacpi_uwb_sw": refer to
1470 Documentation/driver-api/rfkill.rst for details.
1473 Setting keyboard language
1474 -------------------------
1476 sysfs: keyboard_lang
1478 This feature is used to set keyboard language to ECFW using ASL interface.
1479 Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1480 ")" numeric keys, which are not displaying correctly, when keyboard language
1481 is other than "english". This is because the default keyboard language in ECFW
1482 is set as "english". Hence using this sysfs, user can set the correct keyboard
1483 language to ECFW and then these key's will work correctly.
1485 Example of command to set keyboard language is mentioned below::
1487 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1489 Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1490 cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1491 fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1492 nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden),
1498 sysfs: wwan_antenna_type
1500 On some newer Thinkpads we need to set SAR value based on the antenna
1501 type. This interface will be used by userspace to get the antenna type
1502 and set the corresponding SAR value, as is required for FCC certification.
1504 The available commands are::
1506 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1508 Currently 2 antenna types are supported as mentioned below:
1512 The property is read-only. If the platform doesn't have support the sysfs
1513 class is not created.
1520 Some newer Thinkpads have a feature called MAC Address Pass-through. This
1521 feature is implemented by the system firmware to provide a system unique MAC,
1522 that can override a dock or USB ethernet dongle MAC, when connected to a
1523 network. This property enables user-space to easily determine the MAC address
1524 if the feature is enabled.
1526 The values of this auxiliary MAC are:
1528 cat /sys/devices/platform/thinkpad_acpi/auxmac
1530 If the feature is disabled, the value will be 'disabled'.
1532 This property is read-only.
1537 sysfs device attribute: adaptive_kbd_mode
1539 This sysfs attribute controls the keyboard "face" that will be shown on the
1540 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1544 - 1 = Web-browser mode
1545 - 2 = Web-conference mode
1549 For more details about which buttons will appear depending on the mode, please
1550 review the laptop's user guide:
1551 https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf
1553 Battery charge control
1554 ----------------------
1557 /sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1559 These two attributes are created for those batteries that are supported by the
1560 driver. They enable the user to control the battery charge thresholds of the
1561 given battery. Both values may be read and set. `charge_control_start_threshold`
1562 accepts an integer between 0 and 99 (inclusive); this value represents a battery
1563 percentage level, below which charging will begin. `charge_control_end_threshold`
1564 accepts an integer between 1 and 100 (inclusive); this value represents a battery
1565 percentage level, above which charging will stop.
1567 The exact semantics of the attributes may be found in
1568 Documentation/ABI/testing/sysfs-class-power.
1570 Multiple Commands, Module Parameters
1571 ------------------------------------
1573 Multiple commands can be written to the proc files in one shot by
1574 separating them with commas, for example::
1576 echo enable,0xffff > /proc/acpi/ibm/hotkey
1577 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1579 Commands can also be specified when loading the thinkpad-acpi module,
1582 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1585 Enabling debugging output
1586 -------------------------
1588 The module takes a debug parameter which can be used to selectively
1589 enable various classes of debugging output, for example::
1591 modprobe thinkpad_acpi debug=0xffff
1593 will enable all debugging output classes. It takes a bitmask, so
1594 to enable more than one output class, just add their values.
1596 ============= ======================================
1597 Debug bitmask Description
1598 ============= ======================================
1599 0x8000 Disclose PID of userspace programs
1600 accessing some functions of the driver
1601 0x0001 Initialization and probing
1603 0x0004 RF Transmitter control (RFKILL)
1604 (bluetooth, WWAN, UWB...)
1605 0x0008 HKEY event interface, hotkeys
1607 0x0020 Backlight brightness
1608 0x0040 Audio mixer/volume control
1609 ============= ======================================
1611 There is also a kernel build option to enable more debugging
1612 information, which may be necessary to debug driver problems.
1614 The level of debugging information output by the driver can be changed
1615 at runtime through sysfs, using the driver attribute debug_level. The
1616 attribute takes the same bitmask as the debug module parameter above.
1619 Force loading of module
1620 -----------------------
1622 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1623 the module parameter force_load=1. Regardless of whether this works or
1624 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1627 Sysfs interface changelog
1628 ^^^^^^^^^^^^^^^^^^^^^^^^^
1630 ========= ===============================================================
1631 0x000100: Initial sysfs support, as a single platform driver and
1633 0x000200: Hot key support for 32 hot keys, and radio slider switch
1635 0x010000: Hot keys are now handled by default over the input
1636 layer, the radio switch generates input event EV_RADIO,
1637 and the driver enables hot key handling by default in
1640 0x020000: ABI fix: added a separate hwmon platform device and
1641 driver, which must be located by name (thinkpad)
1642 and the hwmon class for libsensors4 (lm-sensors 3)
1643 compatibility. Moved all hwmon attributes to this
1644 new platform device.
1646 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1647 support. If you must, use it to know you should not
1648 start a userspace NVRAM poller (allows to detect when
1649 NVRAM is compiled out by the user because it is
1650 unneeded/undesired in the first place).
1651 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1652 and proper hotkey_mask semantics (version 8 of the
1653 NVRAM polling patch). Some development snapshots of
1654 0.18 had an earlier version that did strange things
1657 0x020200: Add poll()/select() support to the following attributes:
1658 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1660 0x020300: hotkey enable/disable support removed, attributes
1661 hotkey_bios_enabled and hotkey_enable deprecated and
1664 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1665 to not exist in a given model are not registered with
1666 the LED sysfs class anymore.
1668 0x020500: Updated hotkey driver, hotkey_mask is always available
1669 and it is always able to disable hot keys. Very old
1670 thinkpads are properly supported. hotkey_bios_mask
1671 is deprecated and marked for removal.
1673 0x020600: Marker for backlight change event support.
1675 0x020700: Support for mute-only mixers.
1676 Volume control in read-only mode by default.
1677 Marker for ALSA mixer support.
1679 0x030000: Thermal and fan sysfs attributes were moved to the hwmon
1680 device instead of being attached to the backing platform
1682 ========= ===============================================================
projects / linux-modified.git / blob