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
57 A compatibility table by model and feature is maintained on the web
58 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
59 reports, especially if they add to or correct the compatibility table.
60 Please include the following information in your report:
63 - a copy of your ACPI tables, using the "acpidump" utility
64 - a copy of the output of dmidecode, with serial numbers
66 - which driver features work and which don't
67 - the observed behavior of non-working features
69 Any other comments or patches are also more than welcome.
75 If you are compiling this driver as included in the Linux kernel
76 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
77 It is located on the menu path: "Device Drivers" -> "X86 Platform
78 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
84 The driver exports two different interfaces to userspace, which can be
85 used to access the features it provides. One is a legacy procfs-based
86 interface, which will be removed at some time in the future. The other
87 is a new sysfs-based interface which is not complete yet.
89 The procfs interface creates the /proc/acpi/ibm directory. There is a
90 file under that directory for each feature it supports. The procfs
91 interface is mostly frozen, and will change very little if at all: it
92 will not be extended to add any new functionality in the driver, instead
93 all new functionality will be implemented on the sysfs interface.
95 The sysfs interface tries to blend in the generic Linux sysfs subsystems
96 and classes as much as possible. Since some of these subsystems are not
97 yet ready or stabilized, it is expected that this interface will change,
98 and any and all userspace programs must deal with it.
101 Notes about the sysfs interface
102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
104 Unlike what was done with the procfs interface, correctness when talking
105 to the sysfs interfaces will be enforced, as will correctness in the
106 thinkpad-acpi's implementation of sysfs interfaces.
108 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
109 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
110 maximum correctness, even if that means changing an interface in
111 non-compatible ways. As these interfaces mature both in the kernel and
112 in thinkpad-acpi, such changes should become quite rare.
114 Applications interfacing to the thinkpad-acpi sysfs interfaces must
115 follow all sysfs guidelines and correctly process all errors (the sysfs
116 interface makes extensive use of errors). File descriptors and open /
117 close operations to the sysfs inodes must also be properly implemented.
119 The version of thinkpad-acpi's sysfs interface is exported by the driver
120 as a driver attribute (see below).
122 Sysfs driver attributes are on the driver's sysfs attribute space,
123 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
124 /sys/bus/platform/drivers/thinkpad_hwmon/
126 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
127 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
129 Sysfs device attributes for the sensors and fan are on the
130 thinkpad_hwmon device's sysfs attribute space, but you should locate it
131 looking for a hwmon device with the name attribute of "thinkpad", or
132 better yet, through libsensors. For 4.14+ sysfs attributes were moved to the
133 hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or
134 /sys/class/hwmon/hwmon?).
139 procfs: /proc/acpi/ibm/driver
141 sysfs driver attribute: version
143 The driver name and version. No commands can be written to this file.
146 Sysfs interface version
147 -----------------------
149 sysfs driver attribute: interface_version
151 Version of the thinkpad-acpi sysfs interface, as an unsigned long
152 (output in hex format: 0xAAAABBCC), where:
161 The sysfs interface version changelog for the driver can be found at the
162 end of this document. Changes to the sysfs interface done by the kernel
163 subsystems are not documented here, nor are they tracked by this
166 Changes to the thinkpad-acpi sysfs interface are only considered
167 non-experimental when they are submitted to Linux mainline, at which
168 point the changes in this interface are documented and interface_version
169 may be updated. If you are using any thinkpad-acpi features not yet
170 sent to mainline for merging, you do so on your own risk: these features
171 may disappear, or be implemented in a different and incompatible way by
172 the time they are merged in Linux mainline.
174 Changes that are backwards-compatible by nature (e.g. the addition of
175 attributes that do not change the way the other attributes work) do not
176 always warrant an update of interface_version. Therefore, one must
177 expect that an attribute might not be there, and deal with it properly
178 (an attribute not being there *is* a valid way to make it clear that a
179 feature is not available in sysfs).
185 procfs: /proc/acpi/ibm/hotkey
187 sysfs device attribute: hotkey_*
189 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
190 some important events and also keyboard hot key presses to the operating
191 system. Enabling the hotkey functionality of thinkpad-acpi signals the
192 firmware that such a driver is present, and modifies how the ThinkPad
193 firmware will behave in many situations.
195 The driver enables the HKEY ("hot key") event reporting automatically
196 when loaded, and disables it when it is removed.
198 The driver will report HKEY events in the following format::
200 ibm/hotkey HKEY 00000080 0000xxxx
202 Some of these events refer to hot key presses, but not all of them.
204 The driver will generate events over the input layer for hot keys and
205 radio switches, and over the ACPI netlink layer for other events. The
206 input layer support accepts the standard IOCTLs to remap the keycodes
207 assigned to each hot key.
209 The hot key bit mask allows some control over which hot keys generate
210 events. If a key is "masked" (bit set to 0 in the mask), the firmware
211 will handle it. If it is "unmasked", it signals the firmware that
212 thinkpad-acpi would prefer to handle it, if the firmware would be so
213 kind to allow it (and it often doesn't!).
215 Not all bits in the mask can be modified. Not all bits that can be
216 modified do anything. Not all hot keys can be individually controlled
217 by the mask. Some models do not support the mask at all. The behaviour
218 of the mask is, therefore, highly dependent on the ThinkPad model.
220 The driver will filter out any unmasked hotkeys, so even if the firmware
221 doesn't allow disabling an specific hotkey, the driver will not report
222 events for unmasked hotkeys.
224 Note that unmasking some keys prevents their default behavior. For
225 example, if Fn+F5 is unmasked, that key will no longer enable/disable
226 Bluetooth by itself in firmware.
228 Note also that not all Fn key combinations are supported through ACPI
229 depending on the ThinkPad model and firmware version. On those
230 ThinkPads, it is still possible to support some extra hotkeys by
231 polling the "CMOS NVRAM" at least 10 times per second. The driver
232 attempts to enables this functionality automatically when required.
237 The following commands can be written to the /proc/acpi/ibm/hotkey file::
239 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
240 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
241 ... any other 8-hex-digit mask ...
242 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
244 The following commands have been deprecated and will cause the kernel
247 echo enable > /proc/acpi/ibm/hotkey -- does nothing
248 echo disable > /proc/acpi/ibm/hotkey -- returns an error
250 The procfs interface does not support NVRAM polling control. So as to
251 maintain maximum bug-to-bug compatibility, it does not report any masks,
252 nor does it allow one to manipulate the hot key mask when the firmware
253 does not support masks at all, even if NVRAM polling is in use.
259 DEPRECATED, WILL BE REMOVED SOON.
264 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
266 Returns the hot keys mask when thinkpad-acpi was loaded.
267 Upon module unload, the hot keys mask will be restored
268 to this value. This is always 0x80c, because those are
269 the hotkeys that were supported by ancient firmware
270 without mask support.
273 DEPRECATED, WILL BE REMOVED SOON.
279 bit mask to enable reporting (and depending on
280 the firmware, ACPI event generation) for each hot key
281 (see above). Returns the current status of the hot keys
282 mask, and allows one to modify it.
285 bit mask that should enable event reporting for all
286 supported hot keys, when echoed to hotkey_mask above.
287 Unless you know which events need to be handled
288 passively (because the firmware *will* handle them
289 anyway), do *not* use hotkey_all_mask. Use
290 hotkey_recommended_mask, instead. You have been warned.
292 hotkey_recommended_mask:
293 bit mask that should enable event reporting for all
294 supported hot keys, except those which are always
295 handled by the firmware anyway. Echo it to
296 hotkey_mask above, to use. This is the default mask
300 bit mask that selects which hot keys will the driver
301 poll the NVRAM for. This is auto-detected by the driver
302 based on the capabilities reported by the ACPI firmware,
303 but it can be overridden at runtime.
305 Hot keys whose bits are set in hotkey_source_mask are
306 polled for in NVRAM, and reported as hotkey events if
307 enabled in hotkey_mask. Only a few hot keys are
308 available through CMOS NVRAM polling.
310 Warning: when in NVRAM mode, the volume up/down/mute
311 keys are synthesized according to changes in the mixer,
312 which uses a single volume up or volume down hotkey
313 press to unmute, as per the ThinkPad volume mixer user
314 interface. When in ACPI event mode, volume up/down/mute
315 events are reported by the firmware and can behave
316 differently (and that behaviour changes with firmware
317 version -- not just with firmware models -- as well as
321 frequency in Hz for hot key polling. It must be between
322 0 and 25 Hz. Polling is only carried out when strictly
325 Setting hotkey_poll_freq to zero disables polling, and
326 will cause hot key presses that require NVRAM polling
327 to never be reported.
329 Setting hotkey_poll_freq too low may cause repeated
330 pressings of the same hot key to be misreported as a
331 single key press, or to not even be detected at all.
332 The recommended polling frequency is 10Hz.
335 If the ThinkPad has a hardware radio switch, this
336 attribute will read 0 if the switch is in the "radios
337 disabled" position, and 1 if the switch is in the
338 "radios enabled" position.
340 This attribute has poll()/select() support.
343 If the ThinkPad has tablet capabilities, this attribute
344 will read 0 if the ThinkPad is in normal mode, and
345 1 if the ThinkPad is in tablet mode.
347 This attribute has poll()/select() support.
350 Set to 1 if the system is waking up because the user
351 requested a bay ejection. Set to 2 if the system is
352 waking up because the user requested the system to
353 undock. Set to zero for normal wake-ups or wake-ups
354 due to unknown reasons.
356 This attribute has poll()/select() support.
358 wakeup_hotunplug_complete:
359 Set to 1 if the system was waken up because of an
360 undock or bay ejection request, and that request
361 was successfully completed. At this point, it might
362 be useful to send the system back to sleep, at the
363 user's choice. Refer to HKEY events 0x4003 and
366 This attribute has poll()/select() support.
371 A Hot key is mapped to a single input layer EV_KEY event, possibly
372 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
373 code. An EV_SYN event will always be generated to mark the end of the
376 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
377 used as a helper to remap keys, only. They are particularly useful when
378 remapping KEY_UNKNOWN keys.
380 The events are available in an input device, with the following id:
382 ============== ==============================
384 vendor 0x1014 (PCI_VENDOR_ID_IBM) or
385 0x17aa (PCI_VENDOR_ID_LENOVO)
386 product 0x5054 ("TP")
388 ============== ==============================
390 The version will have its LSB incremented if the keymap changes in a
391 backwards-compatible way. The MSB shall always be 0x41 for this input
392 device. If the MSB is not 0x41, do not use the device as described in
393 this section, as it is either something else (e.g. another input device
394 exported by a thinkpad driver, such as HDAPS) or its functionality has
395 been changed in a non-backwards compatible way.
397 Adding other event types for other functionalities shall be considered a
398 backwards-compatible change for this input device.
400 Thinkpad-acpi Hot Key event map (version 0x4101):
402 ======= ======= ============== ==============================================
405 ======= ======= ============== ==============================================
408 0x1002 0x01 FN+F2 IBM: battery (rare)
411 0x1003 0x02 FN+F3 Many IBM models always report
412 this hot key, even with hot keys
413 disabled or with Fn+F3 masked
415 IBM: screen lock, often turns
416 off the ThinkLight as side-effect
419 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
420 semantics, i.e. sleep-to-RAM).
421 It always generates some kind
422 of event, either the hot key
423 event or an ACPI sleep button
424 event. The firmware may
425 refuse to generate further FN+F4
426 key presses until a S3 or S4 ACPI
427 sleep cycle is performed or some
430 0x1005 0x04 FN+F5 Radio. Enables/disables
431 the internal Bluetooth hardware
432 and W-WAN card if left in control
433 of the firmware. Does not affect
435 Should be used to turn on/off all
436 radios (Bluetooth+W-WAN+WLAN),
441 0x1007 0x06 FN+F7 Video output cycle.
442 Do you feel lucky today?
444 0x1008 0x07 FN+F8 IBM: toggle screen expand
445 Lenovo: configure UltraNav,
446 or toggle screen expand
454 0x100C 0x0B FN+F12 Sleep to disk. You are always
455 supposed to handle it yourself,
456 either through the ACPI event,
457 or through a hotkey event.
458 The firmware may refuse to
459 generate further FN+F12 key
460 press events until a S3 or S4
461 ACPI sleep cycle is performed,
464 0x100D 0x0C FN+BACKSPACE -
465 0x100E 0x0D FN+INSERT -
466 0x100F 0x0E FN+DELETE -
468 0x1010 0x0F FN+HOME Brightness up. This key is
469 always handled by the firmware
470 in IBM ThinkPads, even when
471 unmasked. Just leave it alone.
472 For Lenovo ThinkPads with a new
473 BIOS, it has to be handled either
474 by the ACPI OSI, or by userspace.
475 The driver does the right thing,
476 never mess with this.
477 0x1011 0x10 FN+END Brightness down. See brightness
480 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
481 always handled by the firmware,
484 0x1013 0x12 FN+PGDOWN -
486 0x1014 0x13 FN+SPACE Zoom key
488 0x1015 0x14 VOLUME UP Internal mixer volume up. This
489 key is always handled by the
490 firmware, even when unmasked.
491 NOTE: Lenovo seems to be changing
493 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
494 key is always handled by the
495 firmware, even when unmasked.
496 NOTE: Lenovo seems to be changing
498 0x1017 0x16 MUTE Mute internal mixer. This
499 key is always handled by the
500 firmware, even when unmasked.
502 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
509 ======= ======= ============== ==============================================
511 The ThinkPad firmware does not allow one to differentiate when most hot
512 keys are pressed or released (either that, or we don't know how to, yet).
513 For these keys, the driver generates a set of events for a key press and
514 immediately issues the same set of events for a key release. It is
515 unknown by the driver if the ThinkPad firmware triggered these events on
516 hot key press or release, but the firmware will do it for either one, not
519 If a key is mapped to KEY_RESERVED, it generates no input events at all.
520 If a key is mapped to KEY_UNKNOWN, it generates an input event that
521 includes an scan code. If a key is mapped to anything else, it will
522 generate input device EV_KEY events.
524 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
527 ============== ==============================================
528 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
529 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
530 ============== ==============================================
532 Non hotkey ACPI HKEY event map
533 ------------------------------
535 Events that are never propagated by the driver:
537 ====== ==================================================
538 0x2304 System is waking up from suspend to undock
539 0x2305 System is waking up from suspend to eject bay
540 0x2404 System is waking up from hibernation to undock
541 0x2405 System is waking up from hibernation to eject bay
544 0x5009 Tablet swivel: switched to tablet mode
545 0x500A Tablet swivel: switched to normal mode
546 0x5010 Brightness level changed/control event
547 0x6000 KEYBOARD: Numlock key pressed
548 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
549 0x7000 Radio Switch may have changed state
550 ====== ==================================================
553 Events that are propagated by the driver to userspace:
555 ====== =====================================================
556 0x2313 ALARM: System is waking up from suspend because
557 the battery is nearly empty
558 0x2413 ALARM: System is waking up from hibernation because
559 the battery is nearly empty
560 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
561 0x3006 Bay hotplug request (hint to power up SATA link when
562 the optical drive tray is ejected)
563 0x4003 Undocked (see 0x2x04), can sleep again
564 0x4010 Docked into hotplug port replicator (non-ACPI dock)
565 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
566 0x500B Tablet pen inserted into its storage bay
567 0x500C Tablet pen removed from its storage bay
568 0x6011 ALARM: battery is too hot
569 0x6012 ALARM: battery is extremely hot
570 0x6021 ALARM: a sensor is too hot
571 0x6022 ALARM: a sensor is extremely hot
572 0x6030 System thermal table changed
573 0x6032 Thermal Control command set completion (DYTC, Windows)
574 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
575 0x60C0 X1 Yoga 2016, Tablet mode status changed
576 0x60F0 Thermal Transformation changed (GMTS, Windows)
577 ====== =====================================================
579 Battery nearly empty alarms are a last resort attempt to get the
580 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
581 cleanly (0x2413) before power is lost. They must be acted upon, as the
582 wake up caused by the firmware will have negated most safety nets...
584 When any of the "too hot" alarms happen, according to Lenovo the user
585 should suspend or hibernate the laptop (and in the case of battery
586 alarms, unplug the AC adapter) to let it cool down. These alarms do
587 signal that something is wrong, they should never happen on normal
588 operating conditions.
590 The "extremely hot" alarms are emergencies. According to Lenovo, the
591 operating system is to force either an immediate suspend or hibernate
592 cycle, or a system shutdown. Obviously, something is very wrong if this
596 Brightness hotkey notes
597 ^^^^^^^^^^^^^^^^^^^^^^^
599 Don't mess with the brightness hotkeys in a Thinkpad. If you want
600 notifications for OSD, use the sysfs backlight class event support.
602 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
603 automatically for the cases were userspace has to do something to
604 implement brightness changes. When you override these events, you will
605 either fail to handle properly the ThinkPads that require explicit
606 action to change backlight brightness, or the ThinkPads that require
607 that no action be taken to work properly.
613 procfs: /proc/acpi/ibm/bluetooth
615 sysfs device attribute: bluetooth_enable (deprecated)
617 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
619 This feature shows the presence and current state of a ThinkPad
620 Bluetooth device in the internal ThinkPad CDC slot.
622 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
623 so it is kept across reboots and power-off.
628 If Bluetooth is installed, the following commands can be used::
630 echo enable > /proc/acpi/ibm/bluetooth
631 echo disable > /proc/acpi/ibm/bluetooth
636 If the Bluetooth CDC card is installed, it can be enabled /
637 disabled through the "bluetooth_enable" thinkpad-acpi device
638 attribute, and its current status can also be queried.
642 - 0: disables Bluetooth / Bluetooth is disabled
643 - 1: enables Bluetooth / Bluetooth is enabled.
645 Note: this interface has been superseded by the generic rfkill
646 class. It has been deprecated, and it will be removed in year
649 rfkill controller switch "tpacpi_bluetooth_sw": refer to
650 Documentation/driver-api/rfkill.rst for details.
653 Video output control -- /proc/acpi/ibm/video
654 --------------------------------------------
656 This feature allows control over the devices used for video output -
657 LCD, CRT or DVI (if available). The following commands are available::
659 echo lcd_enable > /proc/acpi/ibm/video
660 echo lcd_disable > /proc/acpi/ibm/video
661 echo crt_enable > /proc/acpi/ibm/video
662 echo crt_disable > /proc/acpi/ibm/video
663 echo dvi_enable > /proc/acpi/ibm/video
664 echo dvi_disable > /proc/acpi/ibm/video
665 echo auto_enable > /proc/acpi/ibm/video
666 echo auto_disable > /proc/acpi/ibm/video
667 echo expand_toggle > /proc/acpi/ibm/video
668 echo video_switch > /proc/acpi/ibm/video
671 Access to this feature is restricted to processes owning the
672 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
673 enough with some versions of X.org to crash it.
675 Each video output device can be enabled or disabled individually.
676 Reading /proc/acpi/ibm/video shows the status of each device.
678 Automatic video switching can be enabled or disabled. When automatic
679 video switching is enabled, certain events (e.g. opening the lid,
680 docking or undocking) cause the video output device to change
681 automatically. While this can be useful, it also causes flickering
682 and, on the X40, video corruption. By disabling automatic switching,
683 the flickering or video corruption can be avoided.
685 The video_switch command cycles through the available video outputs
686 (it simulates the behavior of Fn-F7).
688 Video expansion can be toggled through this feature. This controls
689 whether the display is expanded to fill the entire LCD screen when a
690 mode with less than full resolution is used. Note that the current
691 video expansion status cannot be determined through this feature.
693 Note that on many models (particularly those using Radeon graphics
694 chips) the X driver configures the video card in a way which prevents
695 Fn-F7 from working. This also disables the video output switching
696 features of this driver, as it uses the same ACPI methods as
697 Fn-F7. Video switching on the console should still work.
699 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
705 procfs: /proc/acpi/ibm/light
707 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
712 The ThinkLight status can be read and set through the procfs interface. A
713 few models which do not make the status available will show the ThinkLight
714 status as "unknown". The available commands are::
716 echo on > /proc/acpi/ibm/light
717 echo off > /proc/acpi/ibm/light
722 The ThinkLight sysfs interface is documented by the LED class
723 documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name
724 is "tpacpi::thinklight".
726 Due to limitations in the sysfs LED class, if the status of the ThinkLight
727 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
728 It is impossible to know if the status returned through sysfs is valid.
734 procfs: /proc/acpi/ibm/cmos
736 sysfs device attribute: cmos_command
738 This feature is mostly used internally by the ACPI firmware to keep the legacy
739 CMOS NVRAM bits in sync with the current machine state, and to record this
740 state so that the ThinkPad will retain such settings across reboots.
742 Some of these commands actually perform actions in some ThinkPad models, but
743 this is expected to disappear more and more in newer models. As an example, in
744 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
745 real, but commands 0 to 2 don't control the mixer anymore (they have been
746 phased out) and just update the NVRAM.
748 The range of valid cmos command numbers is 0 to 21, but not all have an
749 effect and the behavior varies from model to model. Here is the behavior
750 on the X40 (tpb is the ThinkPad Buttons utility):
752 - 0 - Related to "Volume down" key press
753 - 1 - Related to "Volume up" key press
754 - 2 - Related to "Mute on" key press
755 - 3 - Related to "Access IBM" key press
756 - 4 - Related to "LCD brightness up" key press
757 - 5 - Related to "LCD brightness down" key press
758 - 11 - Related to "toggle screen expansion" key press/function
759 - 12 - Related to "ThinkLight on"
760 - 13 - Related to "ThinkLight off"
761 - 14 - Related to "ThinkLight" key press (toggle ThinkLight)
763 The cmos command interface is prone to firmware split-brain problems, as
764 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
765 exported just as a debug tool.
771 procfs: /proc/acpi/ibm/led
772 sysfs attributes: as per LED class, see below for names
774 Some of the LED indicators can be controlled through this feature. On
775 some older ThinkPad models, it is possible to query the status of the
776 LED indicators as well. Newer ThinkPads cannot query the real status
777 of the LED indicators.
779 Because misuse of the LEDs could induce an unaware user to perform
780 dangerous actions (like undocking or ejecting a bay device while the
781 buses are still active), or mask an important alarm (such as a nearly
782 empty battery, or a broken battery), access to most LEDs is
785 Unrestricted access to all LEDs requires that thinkpad-acpi be
786 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
787 Distributions must never enable this option. Individual users that
788 are aware of the consequences are welcome to enabling it.
790 Audio mute and microphone mute LEDs are supported, but currently not
791 visible to userspace. They are used by the snd-hda-intel audio driver.
796 The available commands are::
798 echo '<LED number> on' >/proc/acpi/ibm/led
799 echo '<LED number> off' >/proc/acpi/ibm/led
800 echo '<LED number> blink' >/proc/acpi/ibm/led
802 The <LED number> range is 0 to 15. The set of LEDs that can be
803 controlled varies from model to model. Here is the common ThinkPad
807 - 1 - battery (orange)
808 - 2 - battery (green)
811 - 5 - UltraBase battery slot
818 - 13, 14, 15 - (unknown)
820 All of the above can be turned on and off and can be made to blink.
825 The ThinkPad LED sysfs interface is described in detail by the LED class
826 documentation, in Documentation/leds/leds-class.rst.
828 The LEDs are named (in LED ID order, from 0 to 12):
829 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
830 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
831 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
832 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
833 "tpacpi::thinkvantage".
835 Due to limitations in the sysfs LED class, if the status of the LED
836 indicators cannot be read due to an error, thinkpad-acpi will report it as
837 a brightness of zero (same as LED off).
839 If the thinkpad firmware doesn't support reading the current status,
840 trying to read the current LED brightness will just return whatever
841 brightness was last written to that attribute.
843 These LEDs can blink using hardware acceleration. To request that a
844 ThinkPad indicator LED should blink in hardware accelerated mode, use the
845 "timer" trigger, and leave the delay_on and delay_off parameters set to
846 zero (to request hardware acceleration autodetection).
848 LEDs that are known not to exist in a given ThinkPad model are not
849 made available through the sysfs interface. If you have a dock and you
850 notice there are LEDs listed for your ThinkPad that do not exist (and
851 are not in the dock), or if you notice that there are missing LEDs,
852 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
855 ACPI sounds -- /proc/acpi/ibm/beep
856 ----------------------------------
858 The BEEP method is used internally by the ACPI firmware to provide
859 audible alerts in various situations. This feature allows the same
860 sounds to be triggered manually.
862 The commands are non-negative integer numbers::
864 echo <number> >/proc/acpi/ibm/beep
866 The valid <number> range is 0 to 17. Not all numbers trigger sounds
867 and the sounds vary from model to model. Here is the behavior on the
870 - 0 - stop a sound in progress (but use 17 to stop 16)
871 - 2 - two beeps, pause, third beep ("low battery")
873 - 4 - high, followed by low-pitched beep ("unable")
875 - 6 - very high, followed by high-pitched beep ("AC/DC")
876 - 7 - high-pitched beep
877 - 9 - three short beeps
878 - 10 - very long beep
879 - 12 - low-pitched beep
880 - 15 - three high-pitched beeps repeating constantly, stop with 0
881 - 16 - one medium-pitched beep repeating constantly, stop with 17
888 procfs: /proc/acpi/ibm/thermal
890 sysfs device attributes: (hwmon "thinkpad") temp*_input
892 Most ThinkPads include six or more separate temperature sensors but only
893 expose the CPU temperature through the standard ACPI methods. This
894 feature shows readings from up to eight different sensors on older
895 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
897 For example, on the X40, a typical output may be:
900 42 42 45 41 36 -128 33 -128
902 On the T43/p, a typical output may be:
905 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
907 The mapping of thermal sensors to physical locations varies depending on
908 system-board model (and thus, on ThinkPad model).
910 https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
911 tries to track down these locations for various models.
913 Most (newer?) models seem to follow this pattern:
916 - 2: (depends on model)
917 - 3: (depends on model)
919 - 5: Main battery: main sensor
920 - 6: Bay battery: main sensor
921 - 7: Main battery: secondary sensor
922 - 8: Bay battery: secondary sensor
923 - 9-15: (depends on model)
925 For the R51 (source: Thomas Gruber):
930 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
931 https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
933 - 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
935 - 9: MCH (northbridge) to DRAM Bus
936 - 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
938 - 11: Power regulator, underside of system board, below F2 key
940 The A31 has a very atypical layout for the thermal sensors
941 (source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
944 - 2: Main Battery: main sensor
946 - 4: Bay Battery: main sensor
947 - 5: MCH (northbridge)
949 - 7: Main Battery: secondary sensor
950 - 8: Bay Battery: secondary sensor
956 Readings from sensors that are not available return -128.
957 No commands can be written to this file.
962 Sensors that are not available return the ENXIO error. This
963 status may change at runtime, as there are hotplug thermal
964 sensors, like those inside the batteries and docks.
966 thinkpad-acpi thermal sensors are reported through the hwmon
967 subsystem, and follow all of the hwmon guidelines at
970 EXPERIMENTAL: Embedded controller register dump
971 -----------------------------------------------
973 This feature is not included in the thinkpad driver anymore.
974 Instead the EC can be accessed through /sys/kernel/debug/ec with
975 a userspace tool which can be found here:
976 ftp://ftp.suse.com/pub/people/trenn/sources/ec
978 Use it to determine the register holding the fan
979 speed on some models. To do that, do the following:
981 - make sure the battery is fully charged
982 - make sure the fan is running
983 - use above mentioned tool to read out the EC
985 Often fan and temperature values vary between
986 readings. Since temperatures don't change vary fast, you can take
987 several quick dumps to eliminate them.
989 You can use a similar method to figure out the meaning of other
990 embedded controller registers - e.g. make sure nothing else changes
991 except the charging or discharging battery to determine which
992 registers contain the current battery capacity, etc. If you experiment
993 with this, do send me your results (including some complete dumps with
994 a description of the conditions when they were taken.)
997 LCD brightness control
998 ----------------------
1000 procfs: /proc/acpi/ibm/brightness
1002 sysfs backlight device "thinkpad_screen"
1004 This feature allows software control of the LCD brightness on ThinkPad
1005 models which don't have a hardware brightness slider.
1007 It has some limitations: the LCD backlight cannot be actually turned
1008 on or off by this interface, it just controls the backlight brightness
1011 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1012 has eight brightness levels, ranging from 0 to 7. Some of the levels
1013 may not be distinct. Later Lenovo models that implement the ACPI
1014 display backlight brightness control methods have 16 levels, ranging
1017 For IBM ThinkPads, there are two interfaces to the firmware for direct
1018 brightness control, EC and UCMS (or CMOS). To select which one should be
1019 used, use the brightness_mode module parameter: brightness_mode=1 selects
1020 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1021 mode with NVRAM backing (so that brightness changes are remembered across
1024 The driver tries to select which interface to use from a table of
1025 defaults for each ThinkPad model. If it makes a wrong choice, please
1026 report this as a bug, so that we can fix it.
1028 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1030 When display backlight brightness controls are available through the
1031 standard ACPI interface, it is best to use it instead of this direct
1032 ThinkPad-specific interface. The driver will disable its native
1033 backlight brightness control interface if it detects that the standard
1034 ACPI interface is available in the ThinkPad.
1036 If you want to use the thinkpad-acpi backlight brightness control
1037 instead of the generic ACPI video backlight brightness control for some
1038 reason, you should use the acpi_backlight=vendor kernel parameter.
1040 The brightness_enable module parameter can be used to control whether
1041 the LCD brightness control feature will be enabled when available.
1042 brightness_enable=0 forces it to be disabled. brightness_enable=1
1043 forces it to be enabled when available, even if the standard ACPI
1044 interface is also available.
1049 The available commands are::
1051 echo up >/proc/acpi/ibm/brightness
1052 echo down >/proc/acpi/ibm/brightness
1053 echo 'level <level>' >/proc/acpi/ibm/brightness
1058 The interface is implemented through the backlight sysfs class, which is
1059 poorly documented at this time.
1061 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1062 it there will be the following attributes:
1065 Reads the maximum brightness the hardware can be set to.
1066 The minimum is always zero.
1069 Reads what brightness the screen is set to at this instant.
1072 Writes request the driver to change brightness to the
1073 given value. Reads will tell you what brightness the
1074 driver is trying to set the display to when "power" is set
1075 to zero and the display has not been dimmed by a kernel
1076 power management event.
1079 power management mode, where 0 is "display on", and 1 to 3
1080 will dim the display backlight to brightness level 0
1081 because thinkpad-acpi cannot really turn the backlight
1082 off. Kernel power management events can temporarily
1083 increase the current power management level, i.e. they can
1089 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1090 interface and the ACPI-based backlight level change interface
1091 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1092 at the same time. The two will interact in bad ways, do funny things,
1093 and maybe reduce the life of the backlight lamps by needlessly kicking
1094 its level up and down at every change.
1097 Volume control (Console Audio control)
1098 --------------------------------------
1100 procfs: /proc/acpi/ibm/volume
1102 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1104 NOTE: by default, the volume control interface operates in read-only
1105 mode, as it is supposed to be used for on-screen-display purposes.
1106 The read/write mode can be enabled through the use of the
1107 "volume_control=1" module parameter.
1109 NOTE: distros are urged to not enable volume_control by default, this
1110 should be done by the local admin only. The ThinkPad UI is for the
1111 console audio control to be done through the volume keys only, and for
1112 the desktop environment to just provide on-screen-display feedback.
1113 Software volume control should be done only in the main AC97/HDA
1117 About the ThinkPad Console Audio control
1118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1120 ThinkPads have a built-in amplifier and muting circuit that drives the
1121 console headphone and speakers. This circuit is after the main AC97
1122 or HDA mixer in the audio path, and under exclusive control of the
1125 ThinkPads have three special hotkeys to interact with the console
1126 audio control: volume up, volume down and mute.
1128 It is worth noting that the normal way the mute function works (on
1129 ThinkPads that do not have a "mute LED") is:
1131 1. Press mute to mute. It will *always* mute, you can press it as
1132 many times as you want, and the sound will remain mute.
1134 2. Press either volume key to unmute the ThinkPad (it will _not_
1135 change the volume, it will just unmute).
1137 This is a very superior design when compared to the cheap software-only
1138 mute-toggle solution found on normal consumer laptops: you can be
1139 absolutely sure the ThinkPad will not make noise if you press the mute
1140 button, no matter the previous state.
1142 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1143 amplifiers driving the speakers and headphone output, and the firmware
1144 also handles volume control for the headphone and speakers on these
1145 ThinkPads without any help from the operating system (this volume
1146 control stage exists after the main AC97 or HDA mixer in the audio
1149 The newer Lenovo models only have firmware mute control, and depend on
1150 the main HDA mixer to do volume control (which is done by the operating
1151 system). In this case, the volume keys are filtered out for unmute
1152 key press (there are some firmware bugs in this area) and delivered as
1153 normal key presses to the operating system (thinkpad-acpi is not
1157 The ThinkPad-ACPI volume control
1158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1160 The preferred way to interact with the Console Audio control is the
1163 The legacy procfs interface allows one to read the current state,
1164 and if volume control is enabled, accepts the following commands::
1166 echo up >/proc/acpi/ibm/volume
1167 echo down >/proc/acpi/ibm/volume
1168 echo mute >/proc/acpi/ibm/volume
1169 echo unmute >/proc/acpi/ibm/volume
1170 echo 'level <level>' >/proc/acpi/ibm/volume
1172 The <level> number range is 0 to 14 although not all of them may be
1173 distinct. To unmute the volume after the mute command, use either the
1174 up or down command (the level command will not unmute the volume), or
1177 You can use the volume_capabilities parameter to tell the driver
1178 whether your thinkpad has volume control or mute-only control:
1179 volume_capabilities=1 for mixers with mute and volume control,
1180 volume_capabilities=2 for mixers with only mute control.
1182 If the driver misdetects the capabilities for your ThinkPad model,
1183 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1184 can update the driver.
1186 There are two strategies for volume control. To select which one
1187 should be used, use the volume_mode module parameter: volume_mode=1
1188 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1189 (so that volume/mute changes are remembered across shutdown/reboot).
1191 The driver will operate in volume_mode=3 by default. If that does not
1192 work well on your ThinkPad model, please report this to
1193 ibm-acpi-devel@lists.sourceforge.net.
1195 The driver supports the standard ALSA module parameters. If the ALSA
1196 mixer is disabled, the driver will disable all volume functionality.
1199 Fan control and monitoring: fan speed, fan enable/disable
1200 ---------------------------------------------------------
1202 procfs: /proc/acpi/ibm/fan
1204 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input
1206 sysfs hwmon driver attributes: fan_watchdog
1209 fan control operations are disabled by default for
1210 safety reasons. To enable them, the module parameter "fan_control=1"
1211 must be given to thinkpad-acpi.
1213 This feature attempts to show the current fan speed, control mode and
1214 other fan data that might be available. The speed is read directly
1215 from the hardware registers of the embedded controller. This is known
1216 to work on later R, T, X and Z series ThinkPads but may show a bogus
1217 value on other models.
1219 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1220 controlled separately, it shares the main fan control.
1225 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1226 stops the fan. The higher the level, the higher the fan speed, although
1227 adjacent levels often map to the same fan speed. 7 is the highest
1228 level, where the fan reaches the maximum recommended speed.
1230 Level "auto" means the EC changes the fan level according to some
1231 internal algorithm, usually based on readings from the thermal sensors.
1233 There is also a "full-speed" level, also known as "disengaged" level.
1234 In this level, the EC disables the speed-locked closed-loop fan control,
1235 and drives the fan as fast as it can go, which might exceed hardware
1236 limits, so use this level with caution.
1238 The fan usually ramps up or down slowly from one speed to another, and
1239 it is normal for the EC to take several seconds to react to fan
1240 commands. The full-speed level may take up to two minutes to ramp up to
1241 maximum speed, and in some ThinkPads, the tachometer readings go stale
1242 while the EC is transitioning to the full-speed level.
1244 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1245 monitoring all of the temperature sensor readings and you are ready to
1246 enable it if necessary to avoid overheating.
1248 An enabled fan in level "auto" may stop spinning if the EC decides the
1249 ThinkPad is cool enough and doesn't need the extra airflow. This is
1250 normal, and the EC will spin the fan up if the various thermal readings
1253 On the X40, this seems to depend on the CPU and HDD temperatures.
1254 Specifically, the fan is turned on when either the CPU temperature
1255 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1256 fan is turned off when the CPU temperature drops to 49 degrees and the
1257 HDD temperature drops to 41 degrees. These thresholds cannot
1258 currently be controlled.
1260 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1261 certain conditions are met. It will override any fan programming done
1262 through thinkpad-acpi.
1264 The thinkpad-acpi kernel driver can be programmed to revert the fan
1265 level to a safe setting if userspace does not issue one of the procfs
1266 fan commands: "enable", "disable", "level" or "watchdog", or if there
1267 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1268 set to 1, manual mode) within a configurable amount of time of up to
1269 120 seconds. This functionality is called fan safety watchdog.
1271 Note that the watchdog timer stops after it enables the fan. It will be
1272 rearmed again automatically (using the same interval) when one of the
1273 above mentioned fan commands is received. The fan watchdog is,
1274 therefore, not suitable to protect against fan mode changes made through
1275 means other than the "enable", "disable", and "level" procfs fan
1276 commands, or the hwmon fan control sysfs interface.
1281 The fan may be enabled or disabled with the following commands::
1283 echo enable >/proc/acpi/ibm/fan
1284 echo disable >/proc/acpi/ibm/fan
1286 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1287 will try to place it in a safe level if it is too slow or disabled.
1289 The fan level can be controlled with the command::
1291 echo 'level <level>' > /proc/acpi/ibm/fan
1293 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1294 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1295 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1296 "full-speed", and reports it as "disengaged" for backwards
1299 On the X31 and X40 (and ONLY on those models), the fan speed can be
1300 controlled to a certain degree. Once the fan is running, it can be
1301 forced to run faster or slower with the following command::
1303 echo 'speed <speed>' > /proc/acpi/ibm/fan
1305 The sustainable range of fan speeds on the X40 appears to be from about
1306 3700 to about 7350. Values outside this range either do not have any
1307 effect or the fan speed eventually settles somewhere in that range. The
1308 fan cannot be stopped or started with this command. This functionality
1309 is incomplete, and not available through the sysfs interface.
1311 To program the safety watchdog, use the "watchdog" command::
1313 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1315 If you want to disable the watchdog, use 0 as the interval.
1320 The sysfs interface follows the hwmon subsystem guidelines for the most
1321 part, and the exception is the fan safety watchdog.
1323 Writes to any of the sysfs attributes may return the EINVAL error if
1324 that operation is not supported in a given ThinkPad or if the parameter
1325 is out-of-bounds, and EPERM if it is forbidden. They may also return
1326 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1329 Features not yet implemented by the driver return ENOSYS.
1331 hwmon device attribute pwm1_enable:
1332 - 0: PWM offline (fan is set to full-speed mode)
1333 - 1: Manual PWM control (use pwm1 to set fan level)
1334 - 2: Hardware PWM control (EC "auto" mode)
1335 - 3: reserved (Software PWM control, not implemented yet)
1337 Modes 0 and 2 are not supported by all ThinkPads, and the
1338 driver is not always able to detect this. If it does know a
1339 mode is unsupported, it will return -EINVAL.
1341 hwmon device attribute pwm1:
1342 Fan level, scaled from the firmware values of 0-7 to the hwmon
1343 scale of 0-255. 0 means fan stopped, 255 means highest normal
1346 This attribute only commands the fan if pmw1_enable is set to 1
1347 (manual PWM control).
1349 hwmon device attribute fan1_input:
1350 Fan tachometer reading, in RPM. May go stale on certain
1351 ThinkPads while the EC transitions the PWM to offline mode,
1352 which can take up to two minutes. May return rubbish on older
1355 hwmon device attribute fan2_input:
1356 Fan tachometer reading, in RPM, for the secondary fan.
1357 Available only on some ThinkPads. If the secondary fan is
1358 not installed, will always read 0.
1360 hwmon driver attribute fan_watchdog:
1361 Fan safety watchdog timer interval, in seconds. Minimum is
1362 1 second, maximum is 120 seconds. 0 disables the watchdog.
1364 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1366 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1367 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1368 would be the safest choice, though).
1374 procfs: /proc/acpi/ibm/wan
1376 sysfs device attribute: wwan_enable (deprecated)
1378 sysfs rfkill class: switch "tpacpi_wwan_sw"
1380 This feature shows the presence and current state of the built-in
1381 Wireless WAN device.
1383 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1384 so it is kept across reboots and power-off.
1386 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1387 ThinkPad models which come with this module installed.
1392 If the W-WAN card is installed, the following commands can be used::
1394 echo enable > /proc/acpi/ibm/wan
1395 echo disable > /proc/acpi/ibm/wan
1400 If the W-WAN card is installed, it can be enabled /
1401 disabled through the "wwan_enable" thinkpad-acpi device
1402 attribute, and its current status can also be queried.
1405 - 0: disables WWAN card / WWAN card is disabled
1406 - 1: enables WWAN card / WWAN card is enabled.
1408 Note: this interface has been superseded by the generic rfkill
1409 class. It has been deprecated, and it will be removed in year
1412 rfkill controller switch "tpacpi_wwan_sw": refer to
1413 Documentation/driver-api/rfkill.rst for details.
1419 procfs: /proc/acpi/ibm/lcdshadow
1421 Some newer T480s and T490s ThinkPads provide a feature called
1422 PrivacyGuard. By turning this feature on, the usable vertical and
1423 horizontal viewing angles of the LCD can be limited (as if some privacy
1424 screen was applied manually in front of the display).
1429 The available commands are::
1431 echo '0' >/proc/acpi/ibm/lcdshadow
1432 echo '1' >/proc/acpi/ibm/lcdshadow
1434 The first command ensures the best viewing angle and the latter one turns
1435 on the feature, restricting the viewing angles.
1443 Newer thinkpads and mobile workstations have the ability to determine if
1444 the device is in deskmode or lapmode. This feature is used by user space
1445 to decide if WWAN transmission can be increased to maximum power and is
1446 also useful for understanding the different thermal modes available as
1447 they differ between desk and lap mode.
1449 The property is read-only. If the platform doesn't have support the sysfs
1450 class is not created.
1455 This feature is considered EXPERIMENTAL because it has not been extensively
1456 tested and validated in various ThinkPad models yet. The feature may not
1457 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1458 the experimental=1 parameter when loading the module.
1460 sysfs rfkill class: switch "tpacpi_uwb_sw"
1462 This feature exports an rfkill controller for the UWB device, if one is
1463 present and enabled in the BIOS.
1468 rfkill controller switch "tpacpi_uwb_sw": refer to
1469 Documentation/driver-api/rfkill.rst for details.
1472 Setting keyboard language
1473 -------------------------
1475 sysfs: keyboard_lang
1477 This feature is used to set keyboard language to ECFW using ASL interface.
1478 Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(',
1479 ")" numeric keys, which are not displaying correctly, when keyboard language
1480 is other than "english". This is because the default keyboard language in ECFW
1481 is set as "english". Hence using this sysfs, user can set the correct keyboard
1482 language to ECFW and then these key's will work correctly.
1484 Example of command to set keyboard language is mentioned below::
1486 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang
1488 Text corresponding to keyboard layout to be set in sysfs are: be(Belgian),
1489 cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian),
1490 fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan),
1491 nl(Dutch), nn(Norway), pl(Polish), pt(portugese), sl(Slovenian), sv(Sweden),
1497 sysfs: wwan_antenna_type
1499 On some newer Thinkpads we need to set SAR value based on the antenna
1500 type. This interface will be used by userspace to get the antenna type
1501 and set the corresponding SAR value, as is required for FCC certification.
1503 The available commands are::
1505 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type
1507 Currently 2 antenna types are supported as mentioned below:
1511 The property is read-only. If the platform doesn't have support the sysfs
1512 class is not created.
1517 sysfs device attribute: adaptive_kbd_mode
1519 This sysfs attribute controls the keyboard "face" that will be shown on the
1520 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read
1524 - 2 = Web-browser mode
1525 - 3 = Web-conference mode
1529 For more details about which buttons will appear depending on the mode, please
1530 review the laptop's user guide:
1531 http://www.lenovo.com/shop/americas/content/user_guides/x1carbon_2_ug_en.pdf
1533 Battery charge control
1534 ----------------------
1537 /sys/class/power_supply/BAT*/charge_control_{start,end}_threshold
1539 These two attributes are created for those batteries that are supported by the
1540 driver. They enable the user to control the battery charge thresholds of the
1541 given battery. Both values may be read and set. `charge_control_start_threshold`
1542 accepts an integer between 0 and 99 (inclusive); this value represents a battery
1543 percentage level, below which charging will begin. `charge_control_end_threshold`
1544 accepts an integer between 1 and 100 (inclusive); this value represents a battery
1545 percentage level, above which charging will stop.
1547 The exact semantics of the attributes may be found in
1548 Documentation/ABI/testing/sysfs-class-power.
1550 Multiple Commands, Module Parameters
1551 ------------------------------------
1553 Multiple commands can be written to the proc files in one shot by
1554 separating them with commas, for example::
1556 echo enable,0xffff > /proc/acpi/ibm/hotkey
1557 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1559 Commands can also be specified when loading the thinkpad-acpi module,
1562 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1565 Enabling debugging output
1566 -------------------------
1568 The module takes a debug parameter which can be used to selectively
1569 enable various classes of debugging output, for example::
1571 modprobe thinkpad_acpi debug=0xffff
1573 will enable all debugging output classes. It takes a bitmask, so
1574 to enable more than one output class, just add their values.
1576 ============= ======================================
1577 Debug bitmask Description
1578 ============= ======================================
1579 0x8000 Disclose PID of userspace programs
1580 accessing some functions of the driver
1581 0x0001 Initialization and probing
1583 0x0004 RF Transmitter control (RFKILL)
1584 (bluetooth, WWAN, UWB...)
1585 0x0008 HKEY event interface, hotkeys
1587 0x0020 Backlight brightness
1588 0x0040 Audio mixer/volume control
1589 ============= ======================================
1591 There is also a kernel build option to enable more debugging
1592 information, which may be necessary to debug driver problems.
1594 The level of debugging information output by the driver can be changed
1595 at runtime through sysfs, using the driver attribute debug_level. The
1596 attribute takes the same bitmask as the debug module parameter above.
1599 Force loading of module
1600 -----------------------
1602 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1603 the module parameter force_load=1. Regardless of whether this works or
1604 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1607 Sysfs interface changelog
1608 ^^^^^^^^^^^^^^^^^^^^^^^^^
1610 ========= ===============================================================
1611 0x000100: Initial sysfs support, as a single platform driver and
1613 0x000200: Hot key support for 32 hot keys, and radio slider switch
1615 0x010000: Hot keys are now handled by default over the input
1616 layer, the radio switch generates input event EV_RADIO,
1617 and the driver enables hot key handling by default in
1620 0x020000: ABI fix: added a separate hwmon platform device and
1621 driver, which must be located by name (thinkpad)
1622 and the hwmon class for libsensors4 (lm-sensors 3)
1623 compatibility. Moved all hwmon attributes to this
1624 new platform device.
1626 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1627 support. If you must, use it to know you should not
1628 start a userspace NVRAM poller (allows to detect when
1629 NVRAM is compiled out by the user because it is
1630 unneeded/undesired in the first place).
1631 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1632 and proper hotkey_mask semantics (version 8 of the
1633 NVRAM polling patch). Some development snapshots of
1634 0.18 had an earlier version that did strange things
1637 0x020200: Add poll()/select() support to the following attributes:
1638 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1640 0x020300: hotkey enable/disable support removed, attributes
1641 hotkey_bios_enabled and hotkey_enable deprecated and
1644 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1645 to not exist in a given model are not registered with
1646 the LED sysfs class anymore.
1648 0x020500: Updated hotkey driver, hotkey_mask is always available
1649 and it is always able to disable hot keys. Very old
1650 thinkpads are properly supported. hotkey_bios_mask
1651 is deprecated and marked for removal.
1653 0x020600: Marker for backlight change event support.
1655 0x020700: Support for mute-only mixers.
1656 Volume control in read-only mode by default.
1657 Marker for ALSA mixer support.
1659 0x030000: Thermal and fan sysfs attributes were moved to the hwmon
1660 device instead of being attached to the backing platform
1662 ========= ===============================================================
projects / linux-2.6-microblaze.git / blob