1 ThinkPad ACPI Extras Driver
6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
8 http://ibm-acpi.sf.net/
11 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
12 supports various features of these laptops which are accessible
13 through the ACPI and ACPI EC framework, but not otherwise fully
14 supported by the generic Linux ACPI drivers.
16 This driver used to be named ibm-acpi until kernel 2.6.21 and release
17 0.13-20070314. It used to be in the drivers/acpi tree, but it was
18 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
19 2.6.22, and release 0.14. It was moved to drivers/platform/x86 for
20 kernel 2.6.29 and release 0.22.
22 The driver is named "thinkpad-acpi". In some places, like module
23 names and log messages, "thinkpad_acpi" is used because of userspace
26 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
27 long due to length limitations on some Linux kernel versions.
32 The features currently supported are the following (see below for
33 detailed description):
36 - Bluetooth enable and disable
37 - video output switching, expansion control
38 - ThinkLight on and off
43 - Experimental: embedded controller register dump
44 - LCD brightness control
46 - Fan control and monitoring: fan speed, fan enable/disable
47 - WAN enable and disable
48 - UWB enable and disable
50 A compatibility table by model and feature is maintained on the web
51 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
52 reports, especially if they add to or correct the compatibility table.
53 Please include the following information in your report:
56 - a copy of your ACPI tables, using the "acpidump" utility
57 - a copy of the output of dmidecode, with serial numbers
59 - which driver features work and which don't
60 - the observed behavior of non-working features
62 Any other comments or patches are also more than welcome.
68 If you are compiling this driver as included in the Linux kernel
69 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
70 It is located on the menu path: "Device Drivers" -> "X86 Platform
71 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
77 The driver exports two different interfaces to userspace, which can be
78 used to access the features it provides. One is a legacy procfs-based
79 interface, which will be removed at some time in the future. The other
80 is a new sysfs-based interface which is not complete yet.
82 The procfs interface creates the /proc/acpi/ibm directory. There is a
83 file under that directory for each feature it supports. The procfs
84 interface is mostly frozen, and will change very little if at all: it
85 will not be extended to add any new functionality in the driver, instead
86 all new functionality will be implemented on the sysfs interface.
88 The sysfs interface tries to blend in the generic Linux sysfs subsystems
89 and classes as much as possible. Since some of these subsystems are not
90 yet ready or stabilized, it is expected that this interface will change,
91 and any and all userspace programs must deal with it.
94 Notes about the sysfs interface:
96 Unlike what was done with the procfs interface, correctness when talking
97 to the sysfs interfaces will be enforced, as will correctness in the
98 thinkpad-acpi's implementation of sysfs interfaces.
100 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
101 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
102 maximum correctness, even if that means changing an interface in
103 non-compatible ways. As these interfaces mature both in the kernel and
104 in thinkpad-acpi, such changes should become quite rare.
106 Applications interfacing to the thinkpad-acpi sysfs interfaces must
107 follow all sysfs guidelines and correctly process all errors (the sysfs
108 interface makes extensive use of errors). File descriptors and open /
109 close operations to the sysfs inodes must also be properly implemented.
111 The version of thinkpad-acpi's sysfs interface is exported by the driver
112 as a driver attribute (see below).
114 Sysfs driver attributes are on the driver's sysfs attribute space,
115 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
116 /sys/bus/platform/drivers/thinkpad_hwmon/
118 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
119 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
121 Sysfs device attributes for the sensors and fan are on the
122 thinkpad_hwmon device's sysfs attribute space, but you should locate it
123 looking for a hwmon device with the name attribute of "thinkpad", or
124 better yet, through libsensors.
130 procfs: /proc/acpi/ibm/driver
131 sysfs driver attribute: version
133 The driver name and version. No commands can be written to this file.
136 Sysfs interface version
137 -----------------------
139 sysfs driver attribute: interface_version
141 Version of the thinkpad-acpi sysfs interface, as an unsigned long
142 (output in hex format: 0xAAAABBCC), where:
143 AAAA - major revision
147 The sysfs interface version changelog for the driver can be found at the
148 end of this document. Changes to the sysfs interface done by the kernel
149 subsystems are not documented here, nor are they tracked by this
152 Changes to the thinkpad-acpi sysfs interface are only considered
153 non-experimental when they are submitted to Linux mainline, at which
154 point the changes in this interface are documented and interface_version
155 may be updated. If you are using any thinkpad-acpi features not yet
156 sent to mainline for merging, you do so on your own risk: these features
157 may disappear, or be implemented in a different and incompatible way by
158 the time they are merged in Linux mainline.
160 Changes that are backwards-compatible by nature (e.g. the addition of
161 attributes that do not change the way the other attributes work) do not
162 always warrant an update of interface_version. Therefore, one must
163 expect that an attribute might not be there, and deal with it properly
164 (an attribute not being there *is* a valid way to make it clear that a
165 feature is not available in sysfs).
171 procfs: /proc/acpi/ibm/hotkey
172 sysfs device attribute: hotkey_*
174 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
175 some important events and also keyboard hot key presses to the operating
176 system. Enabling the hotkey functionality of thinkpad-acpi signals the
177 firmware that such a driver is present, and modifies how the ThinkPad
178 firmware will behave in many situations.
180 The driver enables the HKEY ("hot key") event reporting automatically
181 when loaded, and disables it when it is removed.
183 The driver will report HKEY events in the following format:
185 ibm/hotkey HKEY 00000080 0000xxxx
187 Some of these events refer to hot key presses, but not all of them.
189 The driver will generate events over the input layer for hot keys and
190 radio switches, and over the ACPI netlink layer for other events. The
191 input layer support accepts the standard IOCTLs to remap the keycodes
192 assigned to each hot key.
194 The hot key bit mask allows some control over which hot keys generate
195 events. If a key is "masked" (bit set to 0 in the mask), the firmware
196 will handle it. If it is "unmasked", it signals the firmware that
197 thinkpad-acpi would prefer to handle it, if the firmware would be so
198 kind to allow it (and it often doesn't!).
200 Not all bits in the mask can be modified. Not all bits that can be
201 modified do anything. Not all hot keys can be individually controlled
202 by the mask. Some models do not support the mask at all. The behaviour
203 of the mask is, therefore, highly dependent on the ThinkPad model.
205 The driver will filter out any unmasked hotkeys, so even if the firmware
206 doesn't allow disabling an specific hotkey, the driver will not report
207 events for unmasked hotkeys.
209 Note that unmasking some keys prevents their default behavior. For
210 example, if Fn+F5 is unmasked, that key will no longer enable/disable
211 Bluetooth by itself in firmware.
213 Note also that not all Fn key combinations are supported through ACPI
214 depending on the ThinkPad model and firmware version. On those
215 ThinkPads, it is still possible to support some extra hotkeys by
216 polling the "CMOS NVRAM" at least 10 times per second. The driver
217 attempts to enables this functionality automatically when required.
221 The following commands can be written to the /proc/acpi/ibm/hotkey file:
223 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
224 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
225 ... any other 8-hex-digit mask ...
226 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
228 The following commands have been deprecated and will cause the kernel
231 echo enable > /proc/acpi/ibm/hotkey -- does nothing
232 echo disable > /proc/acpi/ibm/hotkey -- returns an error
234 The procfs interface does not support NVRAM polling control. So as to
235 maintain maximum bug-to-bug compatibility, it does not report any masks,
236 nor does it allow one to manipulate the hot key mask when the firmware
237 does not support masks at all, even if NVRAM polling is in use.
242 DEPRECATED, WILL BE REMOVED SOON.
247 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
249 Returns the hot keys mask when thinkpad-acpi was loaded.
250 Upon module unload, the hot keys mask will be restored
251 to this value. This is always 0x80c, because those are
252 the hotkeys that were supported by ancient firmware
253 without mask support.
256 DEPRECATED, WILL BE REMOVED SOON.
262 bit mask to enable reporting (and depending on
263 the firmware, ACPI event generation) for each hot key
264 (see above). Returns the current status of the hot keys
265 mask, and allows one to modify it.
268 bit mask that should enable event reporting for all
269 supported hot keys, when echoed to hotkey_mask above.
270 Unless you know which events need to be handled
271 passively (because the firmware *will* handle them
272 anyway), do *not* use hotkey_all_mask. Use
273 hotkey_recommended_mask, instead. You have been warned.
275 hotkey_recommended_mask:
276 bit mask that should enable event reporting for all
277 supported hot keys, except those which are always
278 handled by the firmware anyway. Echo it to
279 hotkey_mask above, to use. This is the default mask
283 bit mask that selects which hot keys will the driver
284 poll the NVRAM for. This is auto-detected by the driver
285 based on the capabilities reported by the ACPI firmware,
286 but it can be overridden at runtime.
288 Hot keys whose bits are set in hotkey_source_mask are
289 polled for in NVRAM, and reported as hotkey events if
290 enabled in hotkey_mask. Only a few hot keys are
291 available through CMOS NVRAM polling.
293 Warning: when in NVRAM mode, the volume up/down/mute
294 keys are synthesized according to changes in the mixer,
295 which uses a single volume up or volume down hotkey
296 press to unmute, as per the ThinkPad volume mixer user
297 interface. When in ACPI event mode, volume up/down/mute
298 events are reported by the firmware and can behave
299 differently (and that behaviour changes with firmware
300 version -- not just with firmware models -- as well as
304 frequency in Hz for hot key polling. It must be between
305 0 and 25 Hz. Polling is only carried out when strictly
308 Setting hotkey_poll_freq to zero disables polling, and
309 will cause hot key presses that require NVRAM polling
310 to never be reported.
312 Setting hotkey_poll_freq too low may cause repeated
313 pressings of the same hot key to be misreported as a
314 single key press, or to not even be detected at all.
315 The recommended polling frequency is 10Hz.
318 If the ThinkPad has a hardware radio switch, this
319 attribute will read 0 if the switch is in the "radios
320 disabled" position, and 1 if the switch is in the
321 "radios enabled" position.
323 This attribute has poll()/select() support.
326 If the ThinkPad has tablet capabilities, this attribute
327 will read 0 if the ThinkPad is in normal mode, and
328 1 if the ThinkPad is in tablet mode.
330 This attribute has poll()/select() support.
333 Returns the state of the procfs ACPI event report mode
334 filter for hot keys. If it is set to 1 (the default),
335 all hot key presses are reported both through the input
336 layer and also as ACPI events through procfs (but not
337 through netlink). If it is set to 2, hot key presses
338 are reported only through the input layer.
340 This attribute is read-only in kernels 2.6.23 or later,
341 and read-write on earlier kernels.
343 May return -EPERM (write access locked out by module
344 parameter) or -EACCES (read-only).
347 Set to 1 if the system is waking up because the user
348 requested a bay ejection. Set to 2 if the system is
349 waking up because the user requested the system to
350 undock. Set to zero for normal wake-ups or wake-ups
351 due to unknown reasons.
353 This attribute has poll()/select() support.
355 wakeup_hotunplug_complete:
356 Set to 1 if the system was waken up because of an
357 undock or bay ejection request, and that request
358 was successfully completed. At this point, it might
359 be useful to send the system back to sleep, at the
360 user's choice. Refer to HKEY events 0x4003 and
363 This attribute has poll()/select() support.
367 A Hot key is mapped to a single input layer EV_KEY event, possibly
368 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
369 code. An EV_SYN event will always be generated to mark the end of the
372 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
373 used as a helper to remap keys, only. They are particularly useful when
374 remapping KEY_UNKNOWN keys.
376 The events are available in an input device, with the following id:
379 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
380 0x17aa (PCI_VENDOR_ID_LENOVO)
381 product: 0x5054 ("TP")
384 The version will have its LSB incremented if the keymap changes in a
385 backwards-compatible way. The MSB shall always be 0x41 for this input
386 device. If the MSB is not 0x41, do not use the device as described in
387 this section, as it is either something else (e.g. another input device
388 exported by a thinkpad driver, such as HDAPS) or its functionality has
389 been changed in a non-backwards compatible way.
391 Adding other event types for other functionalities shall be considered a
392 backwards-compatible change for this input device.
394 Thinkpad-acpi Hot Key event map (version 0x4101):
401 0x1002 0x01 FN+F2 IBM: battery (rare)
404 0x1003 0x02 FN+F3 Many IBM models always report
405 this hot key, even with hot keys
406 disabled or with Fn+F3 masked
408 IBM: screen lock, often turns
409 off the ThinkLight as side-effect
412 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
413 semantics, i.e. sleep-to-RAM).
414 It always generates some kind
415 of event, either the hot key
416 event or an ACPI sleep button
417 event. The firmware may
418 refuse to generate further FN+F4
419 key presses until a S3 or S4 ACPI
420 sleep cycle is performed or some
423 0x1005 0x04 FN+F5 Radio. Enables/disables
424 the internal Bluetooth hardware
425 and W-WAN card if left in control
426 of the firmware. Does not affect
428 Should be used to turn on/off all
429 radios (Bluetooth+W-WAN+WLAN),
434 0x1007 0x06 FN+F7 Video output cycle.
435 Do you feel lucky today?
437 0x1008 0x07 FN+F8 IBM: toggle screen expand
438 Lenovo: configure UltraNav,
439 or toggle screen expand
445 0x100C 0x0B FN+F12 Sleep to disk. You are always
446 supposed to handle it yourself,
447 either through the ACPI event,
448 or through a hotkey event.
449 The firmware may refuse to
450 generate further FN+F12 key
451 press events until a S3 or S4
452 ACPI sleep cycle is performed,
455 0x100D 0x0C FN+BACKSPACE -
456 0x100E 0x0D FN+INSERT -
457 0x100F 0x0E FN+DELETE -
459 0x1010 0x0F FN+HOME Brightness up. This key is
460 always handled by the firmware
461 in IBM ThinkPads, even when
462 unmasked. Just leave it alone.
463 For Lenovo ThinkPads with a new
464 BIOS, it has to be handled either
465 by the ACPI OSI, or by userspace.
466 The driver does the right thing,
467 never mess with this.
468 0x1011 0x10 FN+END Brightness down. See brightness
471 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
472 always handled by the firmware,
475 0x1013 0x12 FN+PGDOWN -
477 0x1014 0x13 FN+SPACE Zoom key
479 0x1015 0x14 VOLUME UP Internal mixer volume up. This
480 key is always handled by the
481 firmware, even when unmasked.
482 NOTE: Lenovo seems to be changing
484 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
485 key is always handled by the
486 firmware, even when unmasked.
487 NOTE: Lenovo seems to be changing
489 0x1017 0x16 MUTE Mute internal mixer. This
490 key is always handled by the
491 firmware, even when unmasked.
493 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
499 The ThinkPad firmware does not allow one to differentiate when most hot
500 keys are pressed or released (either that, or we don't know how to, yet).
501 For these keys, the driver generates a set of events for a key press and
502 immediately issues the same set of events for a key release. It is
503 unknown by the driver if the ThinkPad firmware triggered these events on
504 hot key press or release, but the firmware will do it for either one, not
507 If a key is mapped to KEY_RESERVED, it generates no input events at all.
508 If a key is mapped to KEY_UNKNOWN, it generates an input event that
509 includes an scan code. If a key is mapped to anything else, it will
510 generate input device EV_KEY events.
512 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
515 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
516 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
518 Non hotkey ACPI HKEY event map:
519 -------------------------------
521 Events that are not propagated by the driver, except for legacy
522 compatibility purposes when hotkey_report_mode is set to 1:
526 0x5009 Tablet swivel: switched to tablet mode
527 0x500A Tablet swivel: switched to normal mode
528 0x7000 Radio Switch may have changed state
530 Events that are never propagated by the driver:
532 0x2304 System is waking up from suspend to undock
533 0x2305 System is waking up from suspend to eject bay
534 0x2404 System is waking up from hibernation to undock
535 0x2405 System is waking up from hibernation to eject bay
536 0x5010 Brightness level changed/control event
537 0x6000 KEYBOARD: Numlock key pressed
538 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED)
540 Events that are propagated by the driver to userspace:
542 0x2313 ALARM: System is waking up from suspend because
543 the battery is nearly empty
544 0x2413 ALARM: System is waking up from hibernation because
545 the battery is nearly empty
546 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
547 0x3006 Bay hotplug request (hint to power up SATA link when
548 the optical drive tray is ejected)
549 0x4003 Undocked (see 0x2x04), can sleep again
550 0x4010 Docked into hotplug port replicator (non-ACPI dock)
551 0x4011 Undocked from hotplug port replicator (non-ACPI dock)
552 0x500B Tablet pen inserted into its storage bay
553 0x500C Tablet pen removed from its storage bay
554 0x6011 ALARM: battery is too hot
555 0x6012 ALARM: battery is extremely hot
556 0x6021 ALARM: a sensor is too hot
557 0x6022 ALARM: a sensor is extremely hot
558 0x6030 System thermal table changed
559 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED)
561 Battery nearly empty alarms are a last resort attempt to get the
562 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
563 cleanly (0x2413) before power is lost. They must be acted upon, as the
564 wake up caused by the firmware will have negated most safety nets...
566 When any of the "too hot" alarms happen, according to Lenovo the user
567 should suspend or hibernate the laptop (and in the case of battery
568 alarms, unplug the AC adapter) to let it cool down. These alarms do
569 signal that something is wrong, they should never happen on normal
570 operating conditions.
572 The "extremely hot" alarms are emergencies. According to Lenovo, the
573 operating system is to force either an immediate suspend or hibernate
574 cycle, or a system shutdown. Obviously, something is very wrong if this
579 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
580 supported the input layer, and sent events over the procfs ACPI event
583 To avoid sending duplicate events over the input layer and the ACPI
584 event interface, thinkpad-acpi 0.16 implements a module parameter
585 (hotkey_report_mode), and also a sysfs device attribute with the same
588 Make no mistake here: userspace is expected to switch to using the input
589 layer interface of thinkpad-acpi, together with the ACPI netlink event
590 interface in kernels 2.6.23 and later, or with the ACPI procfs event
591 interface in kernels 2.6.22 and earlier.
593 If no hotkey_report_mode module parameter is specified (or it is set to
594 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
595 and earlier, also allows one to change the hotkey_report_mode through
596 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
597 interface is available, hotkey_report_mode cannot be changed through
598 sysfs (it is read-only).
600 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
601 be changed later through sysfs (any writes will return -EPERM to signal
602 that hotkey_report_mode was locked. On 2.6.23 and later, where
603 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
605 hotkey_report_mode set to 1 makes the driver export through the procfs
606 ACPI event interface all hot key presses (which are *also* sent to the
607 input layer). This is a legacy compatibility behaviour, and it is also
608 the default mode of operation for the driver.
610 hotkey_report_mode set to 2 makes the driver filter out the hot key
611 presses from the procfs ACPI event interface, so these events will only
612 be sent through the input layer. Userspace that has been updated to use
613 the thinkpad-acpi input layer interface should set hotkey_report_mode to
616 Hot key press events are never sent to the ACPI netlink event interface.
617 Really up-to-date userspace under kernel 2.6.23 and later is to use the
618 netlink interface and the input layer interface, and don't bother at all
619 with hotkey_report_mode.
622 Brightness hotkey notes:
624 Don't mess with the brightness hotkeys in a Thinkpad. If you want
625 notifications for OSD, use the sysfs backlight class event support.
627 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
628 automatically for the cases were userspace has to do something to
629 implement brightness changes. When you override these events, you will
630 either fail to handle properly the ThinkPads that require explicit
631 action to change backlight brightness, or the ThinkPads that require
632 that no action be taken to work properly.
638 procfs: /proc/acpi/ibm/bluetooth
639 sysfs device attribute: bluetooth_enable (deprecated)
640 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
642 This feature shows the presence and current state of a ThinkPad
643 Bluetooth device in the internal ThinkPad CDC slot.
645 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
646 so it is kept across reboots and power-off.
650 If Bluetooth is installed, the following commands can be used:
652 echo enable > /proc/acpi/ibm/bluetooth
653 echo disable > /proc/acpi/ibm/bluetooth
657 If the Bluetooth CDC card is installed, it can be enabled /
658 disabled through the "bluetooth_enable" thinkpad-acpi device
659 attribute, and its current status can also be queried.
662 0: disables Bluetooth / Bluetooth is disabled
663 1: enables Bluetooth / Bluetooth is enabled.
665 Note: this interface has been superseded by the generic rfkill
666 class. It has been deprecated, and it will be removed in year
669 rfkill controller switch "tpacpi_bluetooth_sw": refer to
670 Documentation/rfkill.txt for details.
673 Video output control -- /proc/acpi/ibm/video
674 --------------------------------------------
676 This feature allows control over the devices used for video output -
677 LCD, CRT or DVI (if available). The following commands are available:
679 echo lcd_enable > /proc/acpi/ibm/video
680 echo lcd_disable > /proc/acpi/ibm/video
681 echo crt_enable > /proc/acpi/ibm/video
682 echo crt_disable > /proc/acpi/ibm/video
683 echo dvi_enable > /proc/acpi/ibm/video
684 echo dvi_disable > /proc/acpi/ibm/video
685 echo auto_enable > /proc/acpi/ibm/video
686 echo auto_disable > /proc/acpi/ibm/video
687 echo expand_toggle > /proc/acpi/ibm/video
688 echo video_switch > /proc/acpi/ibm/video
690 NOTE: Access to this feature is restricted to processes owning the
691 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
692 enough with some versions of X.org to crash it.
694 Each video output device can be enabled or disabled individually.
695 Reading /proc/acpi/ibm/video shows the status of each device.
697 Automatic video switching can be enabled or disabled. When automatic
698 video switching is enabled, certain events (e.g. opening the lid,
699 docking or undocking) cause the video output device to change
700 automatically. While this can be useful, it also causes flickering
701 and, on the X40, video corruption. By disabling automatic switching,
702 the flickering or video corruption can be avoided.
704 The video_switch command cycles through the available video outputs
705 (it simulates the behavior of Fn-F7).
707 Video expansion can be toggled through this feature. This controls
708 whether the display is expanded to fill the entire LCD screen when a
709 mode with less than full resolution is used. Note that the current
710 video expansion status cannot be determined through this feature.
712 Note that on many models (particularly those using Radeon graphics
713 chips) the X driver configures the video card in a way which prevents
714 Fn-F7 from working. This also disables the video output switching
715 features of this driver, as it uses the same ACPI methods as
716 Fn-F7. Video switching on the console should still work.
718 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
724 procfs: /proc/acpi/ibm/light
725 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
729 The ThinkLight status can be read and set through the procfs interface. A
730 few models which do not make the status available will show the ThinkLight
731 status as "unknown". The available commands are:
733 echo on > /proc/acpi/ibm/light
734 echo off > /proc/acpi/ibm/light
738 The ThinkLight sysfs interface is documented by the LED class
739 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
740 is "tpacpi::thinklight".
742 Due to limitations in the sysfs LED class, if the status of the ThinkLight
743 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
744 It is impossible to know if the status returned through sysfs is valid.
750 procfs: /proc/acpi/ibm/cmos
751 sysfs device attribute: cmos_command
753 This feature is mostly used internally by the ACPI firmware to keep the legacy
754 CMOS NVRAM bits in sync with the current machine state, and to record this
755 state so that the ThinkPad will retain such settings across reboots.
757 Some of these commands actually perform actions in some ThinkPad models, but
758 this is expected to disappear more and more in newer models. As an example, in
759 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
760 real, but commands 0 to 2 don't control the mixer anymore (they have been
761 phased out) and just update the NVRAM.
763 The range of valid cmos command numbers is 0 to 21, but not all have an
764 effect and the behavior varies from model to model. Here is the behavior
765 on the X40 (tpb is the ThinkPad Buttons utility):
767 0 - Related to "Volume down" key press
768 1 - Related to "Volume up" key press
769 2 - Related to "Mute on" key press
770 3 - Related to "Access IBM" key press
771 4 - Related to "LCD brightness up" key press
772 5 - Related to "LCD brightness down" key press
773 11 - Related to "toggle screen expansion" key press/function
774 12 - Related to "ThinkLight on"
775 13 - Related to "ThinkLight off"
776 14 - Related to "ThinkLight" key press (toggle ThinkLight)
778 The cmos command interface is prone to firmware split-brain problems, as
779 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
780 exported just as a debug tool.
786 procfs: /proc/acpi/ibm/led
787 sysfs attributes: as per LED class, see below for names
789 Some of the LED indicators can be controlled through this feature. On
790 some older ThinkPad models, it is possible to query the status of the
791 LED indicators as well. Newer ThinkPads cannot query the real status
792 of the LED indicators.
794 Because misuse of the LEDs could induce an unaware user to perform
795 dangerous actions (like undocking or ejecting a bay device while the
796 buses are still active), or mask an important alarm (such as a nearly
797 empty battery, or a broken battery), access to most LEDs is
800 Unrestricted access to all LEDs requires that thinkpad-acpi be
801 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
802 Distributions must never enable this option. Individual users that
803 are aware of the consequences are welcome to enabling it.
807 The available commands are:
809 echo '<LED number> on' >/proc/acpi/ibm/led
810 echo '<LED number> off' >/proc/acpi/ibm/led
811 echo '<LED number> blink' >/proc/acpi/ibm/led
813 The <LED number> range is 0 to 15. The set of LEDs that can be
814 controlled varies from model to model. Here is the common ThinkPad
822 5 - UltraBase battery slot
829 13, 14, 15 - (unknown)
831 All of the above can be turned on and off and can be made to blink.
835 The ThinkPad LED sysfs interface is described in detail by the LED class
836 documentation, in Documentation/leds-class.txt.
838 The LEDs are named (in LED ID order, from 0 to 12):
839 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
840 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
841 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
842 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
843 "tpacpi::thinkvantage".
845 Due to limitations in the sysfs LED class, if the status of the LED
846 indicators cannot be read due to an error, thinkpad-acpi will report it as
847 a brightness of zero (same as LED off).
849 If the thinkpad firmware doesn't support reading the current status,
850 trying to read the current LED brightness will just return whatever
851 brightness was last written to that attribute.
853 These LEDs can blink using hardware acceleration. To request that a
854 ThinkPad indicator LED should blink in hardware accelerated mode, use the
855 "timer" trigger, and leave the delay_on and delay_off parameters set to
856 zero (to request hardware acceleration autodetection).
858 LEDs that are known not to exist in a given ThinkPad model are not
859 made available through the sysfs interface. If you have a dock and you
860 notice there are LEDs listed for your ThinkPad that do not exist (and
861 are not in the dock), or if you notice that there are missing LEDs,
862 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
865 ACPI sounds -- /proc/acpi/ibm/beep
866 ----------------------------------
868 The BEEP method is used internally by the ACPI firmware to provide
869 audible alerts in various situations. This feature allows the same
870 sounds to be triggered manually.
872 The commands are non-negative integer numbers:
874 echo <number> >/proc/acpi/ibm/beep
876 The valid <number> range is 0 to 17. Not all numbers trigger sounds
877 and the sounds vary from model to model. Here is the behavior on the
880 0 - stop a sound in progress (but use 17 to stop 16)
881 2 - two beeps, pause, third beep ("low battery")
883 4 - high, followed by low-pitched beep ("unable")
885 6 - very high, followed by high-pitched beep ("AC/DC")
886 7 - high-pitched beep
887 9 - three short beeps
889 12 - low-pitched beep
890 15 - three high-pitched beeps repeating constantly, stop with 0
891 16 - one medium-pitched beep repeating constantly, stop with 17
898 procfs: /proc/acpi/ibm/thermal
899 sysfs device attributes: (hwmon "thinkpad") temp*_input
901 Most ThinkPads include six or more separate temperature sensors but only
902 expose the CPU temperature through the standard ACPI methods. This
903 feature shows readings from up to eight different sensors on older
904 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
906 For example, on the X40, a typical output may be:
907 temperatures: 42 42 45 41 36 -128 33 -128
909 On the T43/p, a typical output may be:
910 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
912 The mapping of thermal sensors to physical locations varies depending on
913 system-board model (and thus, on ThinkPad model).
915 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
916 tries to track down these locations for various models.
918 Most (newer?) models seem to follow this pattern:
921 2: (depends on model)
922 3: (depends on model)
924 5: Main battery: main sensor
925 6: Bay battery: main sensor
926 7: Main battery: secondary sensor
927 8: Bay battery: secondary sensor
928 9-15: (depends on model)
930 For the R51 (source: Thomas Gruber):
934 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
935 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
936 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
938 9: MCH (northbridge) to DRAM Bus
939 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
941 11: Power regulator, underside of system board, below F2 key
943 The A31 has a very atypical layout for the thermal sensors
944 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
946 2: Main Battery: main sensor
948 4: Bay Battery: main sensor
951 7: Main Battery: secondary sensor
952 8: Bay Battery: secondary sensor
956 Readings from sensors that are not available return -128.
957 No commands can be written to this file.
960 Sensors that are not available return the ENXIO error. This
961 status may change at runtime, as there are hotplug thermal
962 sensors, like those inside the batteries and docks.
964 thinkpad-acpi thermal sensors are reported through the hwmon
965 subsystem, and follow all of the hwmon guidelines at
968 EXPERIMENTAL: Embedded controller register dump
969 -----------------------------------------------
971 This feature is not included in the thinkpad driver anymore.
972 Instead the EC can be accessed through /sys/kernel/debug/ec with
973 a userspace tool which can be found here:
974 ftp://ftp.suse.com/pub/people/trenn/sources/ec
976 Use it to determine the register holding the fan
977 speed on some models. To do that, do the following:
978 - make sure the battery is fully charged
979 - make sure the fan is running
980 - use above mentioned tool to read out the EC
982 Often fan and temperature values vary between
983 readings. Since temperatures don't change vary fast, you can take
984 several quick dumps to eliminate them.
986 You can use a similar method to figure out the meaning of other
987 embedded controller registers - e.g. make sure nothing else changes
988 except the charging or discharging battery to determine which
989 registers contain the current battery capacity, etc. If you experiment
990 with this, do send me your results (including some complete dumps with
991 a description of the conditions when they were taken.)
994 LCD brightness control
995 ----------------------
997 procfs: /proc/acpi/ibm/brightness
998 sysfs backlight device "thinkpad_screen"
1000 This feature allows software control of the LCD brightness on ThinkPad
1001 models which don't have a hardware brightness slider.
1003 It has some limitations: the LCD backlight cannot be actually turned
1004 on or off by this interface, it just controls the backlight brightness
1007 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1008 has eight brightness levels, ranging from 0 to 7. Some of the levels
1009 may not be distinct. Later Lenovo models that implement the ACPI
1010 display backlight brightness control methods have 16 levels, ranging
1013 For IBM ThinkPads, there are two interfaces to the firmware for direct
1014 brightness control, EC and UCMS (or CMOS). To select which one should be
1015 used, use the brightness_mode module parameter: brightness_mode=1 selects
1016 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1017 mode with NVRAM backing (so that brightness changes are remembered across
1020 The driver tries to select which interface to use from a table of
1021 defaults for each ThinkPad model. If it makes a wrong choice, please
1022 report this as a bug, so that we can fix it.
1024 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1026 When display backlight brightness controls are available through the
1027 standard ACPI interface, it is best to use it instead of this direct
1028 ThinkPad-specific interface. The driver will disable its native
1029 backlight brightness control interface if it detects that the standard
1030 ACPI interface is available in the ThinkPad.
1032 If you want to use the thinkpad-acpi backlight brightness control
1033 instead of the generic ACPI video backlight brightness control for some
1034 reason, you should use the acpi_backlight=vendor kernel parameter.
1036 The brightness_enable module parameter can be used to control whether
1037 the LCD brightness control feature will be enabled when available.
1038 brightness_enable=0 forces it to be disabled. brightness_enable=1
1039 forces it to be enabled when available, even if the standard ACPI
1040 interface is also available.
1044 The available commands are:
1046 echo up >/proc/acpi/ibm/brightness
1047 echo down >/proc/acpi/ibm/brightness
1048 echo 'level <level>' >/proc/acpi/ibm/brightness
1052 The interface is implemented through the backlight sysfs class, which is
1053 poorly documented at this time.
1055 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1056 it there will be the following attributes:
1059 Reads the maximum brightness the hardware can be set to.
1060 The minimum is always zero.
1063 Reads what brightness the screen is set to at this instant.
1066 Writes request the driver to change brightness to the
1067 given value. Reads will tell you what brightness the
1068 driver is trying to set the display to when "power" is set
1069 to zero and the display has not been dimmed by a kernel
1070 power management event.
1073 power management mode, where 0 is "display on", and 1 to 3
1074 will dim the display backlight to brightness level 0
1075 because thinkpad-acpi cannot really turn the backlight
1076 off. Kernel power management events can temporarily
1077 increase the current power management level, i.e. they can
1083 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1084 interface and the ACPI-based backlight level change interface
1085 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1086 at the same time. The two will interact in bad ways, do funny things,
1087 and maybe reduce the life of the backlight lamps by needlessly kicking
1088 its level up and down at every change.
1091 Volume control (Console Audio control)
1092 --------------------------------------
1094 procfs: /proc/acpi/ibm/volume
1095 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1097 NOTE: by default, the volume control interface operates in read-only
1098 mode, as it is supposed to be used for on-screen-display purposes.
1099 The read/write mode can be enabled through the use of the
1100 "volume_control=1" module parameter.
1102 NOTE: distros are urged to not enable volume_control by default, this
1103 should be done by the local admin only. The ThinkPad UI is for the
1104 console audio control to be done through the volume keys only, and for
1105 the desktop environment to just provide on-screen-display feedback.
1106 Software volume control should be done only in the main AC97/HDA
1110 About the ThinkPad Console Audio control:
1112 ThinkPads have a built-in amplifier and muting circuit that drives the
1113 console headphone and speakers. This circuit is after the main AC97
1114 or HDA mixer in the audio path, and under exclusive control of the
1117 ThinkPads have three special hotkeys to interact with the console
1118 audio control: volume up, volume down and mute.
1120 It is worth noting that the normal way the mute function works (on
1121 ThinkPads that do not have a "mute LED") is:
1123 1. Press mute to mute. It will *always* mute, you can press it as
1124 many times as you want, and the sound will remain mute.
1126 2. Press either volume key to unmute the ThinkPad (it will _not_
1127 change the volume, it will just unmute).
1129 This is a very superior design when compared to the cheap software-only
1130 mute-toggle solution found on normal consumer laptops: you can be
1131 absolutely sure the ThinkPad will not make noise if you press the mute
1132 button, no matter the previous state.
1134 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1135 amplifiers driving the speakers and headphone output, and the firmware
1136 also handles volume control for the headphone and speakers on these
1137 ThinkPads without any help from the operating system (this volume
1138 control stage exists after the main AC97 or HDA mixer in the audio
1141 The newer Lenovo models only have firmware mute control, and depend on
1142 the main HDA mixer to do volume control (which is done by the operating
1143 system). In this case, the volume keys are filtered out for unmute
1144 key press (there are some firmware bugs in this area) and delivered as
1145 normal key presses to the operating system (thinkpad-acpi is not
1149 The ThinkPad-ACPI volume control:
1151 The preferred way to interact with the Console Audio control is the
1154 The legacy procfs interface allows one to read the current state,
1155 and if volume control is enabled, accepts the following commands:
1157 echo up >/proc/acpi/ibm/volume
1158 echo down >/proc/acpi/ibm/volume
1159 echo mute >/proc/acpi/ibm/volume
1160 echo unmute >/proc/acpi/ibm/volume
1161 echo 'level <level>' >/proc/acpi/ibm/volume
1163 The <level> number range is 0 to 14 although not all of them may be
1164 distinct. To unmute the volume after the mute command, use either the
1165 up or down command (the level command will not unmute the volume), or
1168 You can use the volume_capabilities parameter to tell the driver
1169 whether your thinkpad has volume control or mute-only control:
1170 volume_capabilities=1 for mixers with mute and volume control,
1171 volume_capabilities=2 for mixers with only mute control.
1173 If the driver misdetects the capabilities for your ThinkPad model,
1174 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1175 can update the driver.
1177 There are two strategies for volume control. To select which one
1178 should be used, use the volume_mode module parameter: volume_mode=1
1179 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1180 (so that volume/mute changes are remembered across shutdown/reboot).
1182 The driver will operate in volume_mode=3 by default. If that does not
1183 work well on your ThinkPad model, please report this to
1184 ibm-acpi-devel@lists.sourceforge.net.
1186 The driver supports the standard ALSA module parameters. If the ALSA
1187 mixer is disabled, the driver will disable all volume functionality.
1190 Fan control and monitoring: fan speed, fan enable/disable
1191 ---------------------------------------------------------
1193 procfs: /proc/acpi/ibm/fan
1194 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1195 pwm1_enable, fan2_input
1196 sysfs hwmon driver attributes: fan_watchdog
1198 NOTE NOTE NOTE: fan control operations are disabled by default for
1199 safety reasons. To enable them, the module parameter "fan_control=1"
1200 must be given to thinkpad-acpi.
1202 This feature attempts to show the current fan speed, control mode and
1203 other fan data that might be available. The speed is read directly
1204 from the hardware registers of the embedded controller. This is known
1205 to work on later R, T, X and Z series ThinkPads but may show a bogus
1206 value on other models.
1208 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1209 controlled separately, it shares the main fan control.
1213 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1214 stops the fan. The higher the level, the higher the fan speed, although
1215 adjacent levels often map to the same fan speed. 7 is the highest
1216 level, where the fan reaches the maximum recommended speed.
1218 Level "auto" means the EC changes the fan level according to some
1219 internal algorithm, usually based on readings from the thermal sensors.
1221 There is also a "full-speed" level, also known as "disengaged" level.
1222 In this level, the EC disables the speed-locked closed-loop fan control,
1223 and drives the fan as fast as it can go, which might exceed hardware
1224 limits, so use this level with caution.
1226 The fan usually ramps up or down slowly from one speed to another, and
1227 it is normal for the EC to take several seconds to react to fan
1228 commands. The full-speed level may take up to two minutes to ramp up to
1229 maximum speed, and in some ThinkPads, the tachometer readings go stale
1230 while the EC is transitioning to the full-speed level.
1232 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1233 monitoring all of the temperature sensor readings and you are ready to
1234 enable it if necessary to avoid overheating.
1236 An enabled fan in level "auto" may stop spinning if the EC decides the
1237 ThinkPad is cool enough and doesn't need the extra airflow. This is
1238 normal, and the EC will spin the fan up if the various thermal readings
1241 On the X40, this seems to depend on the CPU and HDD temperatures.
1242 Specifically, the fan is turned on when either the CPU temperature
1243 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1244 fan is turned off when the CPU temperature drops to 49 degrees and the
1245 HDD temperature drops to 41 degrees. These thresholds cannot
1246 currently be controlled.
1248 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1249 certain conditions are met. It will override any fan programming done
1250 through thinkpad-acpi.
1252 The thinkpad-acpi kernel driver can be programmed to revert the fan
1253 level to a safe setting if userspace does not issue one of the procfs
1254 fan commands: "enable", "disable", "level" or "watchdog", or if there
1255 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1256 set to 1, manual mode) within a configurable amount of time of up to
1257 120 seconds. This functionality is called fan safety watchdog.
1259 Note that the watchdog timer stops after it enables the fan. It will be
1260 rearmed again automatically (using the same interval) when one of the
1261 above mentioned fan commands is received. The fan watchdog is,
1262 therefore, not suitable to protect against fan mode changes made through
1263 means other than the "enable", "disable", and "level" procfs fan
1264 commands, or the hwmon fan control sysfs interface.
1268 The fan may be enabled or disabled with the following commands:
1270 echo enable >/proc/acpi/ibm/fan
1271 echo disable >/proc/acpi/ibm/fan
1273 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1274 will try to place it in a safe level if it is too slow or disabled.
1276 The fan level can be controlled with the command:
1278 echo 'level <level>' > /proc/acpi/ibm/fan
1280 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1281 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1282 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1283 "full-speed", and reports it as "disengaged" for backwards
1286 On the X31 and X40 (and ONLY on those models), the fan speed can be
1287 controlled to a certain degree. Once the fan is running, it can be
1288 forced to run faster or slower with the following command:
1290 echo 'speed <speed>' > /proc/acpi/ibm/fan
1292 The sustainable range of fan speeds on the X40 appears to be from about
1293 3700 to about 7350. Values outside this range either do not have any
1294 effect or the fan speed eventually settles somewhere in that range. The
1295 fan cannot be stopped or started with this command. This functionality
1296 is incomplete, and not available through the sysfs interface.
1298 To program the safety watchdog, use the "watchdog" command.
1300 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1302 If you want to disable the watchdog, use 0 as the interval.
1306 The sysfs interface follows the hwmon subsystem guidelines for the most
1307 part, and the exception is the fan safety watchdog.
1309 Writes to any of the sysfs attributes may return the EINVAL error if
1310 that operation is not supported in a given ThinkPad or if the parameter
1311 is out-of-bounds, and EPERM if it is forbidden. They may also return
1312 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1315 Features not yet implemented by the driver return ENOSYS.
1317 hwmon device attribute pwm1_enable:
1318 0: PWM offline (fan is set to full-speed mode)
1319 1: Manual PWM control (use pwm1 to set fan level)
1320 2: Hardware PWM control (EC "auto" mode)
1321 3: reserved (Software PWM control, not implemented yet)
1323 Modes 0 and 2 are not supported by all ThinkPads, and the
1324 driver is not always able to detect this. If it does know a
1325 mode is unsupported, it will return -EINVAL.
1327 hwmon device attribute pwm1:
1328 Fan level, scaled from the firmware values of 0-7 to the hwmon
1329 scale of 0-255. 0 means fan stopped, 255 means highest normal
1332 This attribute only commands the fan if pmw1_enable is set to 1
1333 (manual PWM control).
1335 hwmon device attribute fan1_input:
1336 Fan tachometer reading, in RPM. May go stale on certain
1337 ThinkPads while the EC transitions the PWM to offline mode,
1338 which can take up to two minutes. May return rubbish on older
1341 hwmon device attribute fan2_input:
1342 Fan tachometer reading, in RPM, for the secondary fan.
1343 Available only on some ThinkPads. If the secondary fan is
1344 not installed, will always read 0.
1346 hwmon driver attribute fan_watchdog:
1347 Fan safety watchdog timer interval, in seconds. Minimum is
1348 1 second, maximum is 120 seconds. 0 disables the watchdog.
1350 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1352 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1353 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1354 would be the safest choice, though).
1360 procfs: /proc/acpi/ibm/wan
1361 sysfs device attribute: wwan_enable (deprecated)
1362 sysfs rfkill class: switch "tpacpi_wwan_sw"
1364 This feature shows the presence and current state of the built-in
1365 Wireless WAN device.
1367 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1368 so it is kept across reboots and power-off.
1370 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1371 ThinkPad models which come with this module installed.
1375 If the W-WAN card is installed, the following commands can be used:
1377 echo enable > /proc/acpi/ibm/wan
1378 echo disable > /proc/acpi/ibm/wan
1382 If the W-WAN card is installed, it can be enabled /
1383 disabled through the "wwan_enable" thinkpad-acpi device
1384 attribute, and its current status can also be queried.
1387 0: disables WWAN card / WWAN card is disabled
1388 1: enables WWAN card / WWAN card is enabled.
1390 Note: this interface has been superseded by the generic rfkill
1391 class. It has been deprecated, and it will be removed in year
1394 rfkill controller switch "tpacpi_wwan_sw": refer to
1395 Documentation/rfkill.txt for details.
1401 This feature is marked EXPERIMENTAL because it has not been extensively
1402 tested and validated in various ThinkPad models yet. The feature may not
1403 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1404 the experimental=1 parameter when loading the module.
1406 sysfs rfkill class: switch "tpacpi_uwb_sw"
1408 This feature exports an rfkill controller for the UWB device, if one is
1409 present and enabled in the BIOS.
1413 rfkill controller switch "tpacpi_uwb_sw": refer to
1414 Documentation/rfkill.txt for details.
1417 Multiple Commands, Module Parameters
1418 ------------------------------------
1420 Multiple commands can be written to the proc files in one shot by
1421 separating them with commas, for example:
1423 echo enable,0xffff > /proc/acpi/ibm/hotkey
1424 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1426 Commands can also be specified when loading the thinkpad-acpi module,
1429 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1432 Enabling debugging output
1433 -------------------------
1435 The module takes a debug parameter which can be used to selectively
1436 enable various classes of debugging output, for example:
1438 modprobe thinkpad_acpi debug=0xffff
1440 will enable all debugging output classes. It takes a bitmask, so
1441 to enable more than one output class, just add their values.
1443 Debug bitmask Description
1444 0x8000 Disclose PID of userspace programs
1445 accessing some functions of the driver
1446 0x0001 Initialization and probing
1448 0x0004 RF Transmitter control (RFKILL)
1449 (bluetooth, WWAN, UWB...)
1450 0x0008 HKEY event interface, hotkeys
1452 0x0020 Backlight brightness
1453 0x0040 Audio mixer/volume control
1455 There is also a kernel build option to enable more debugging
1456 information, which may be necessary to debug driver problems.
1458 The level of debugging information output by the driver can be changed
1459 at runtime through sysfs, using the driver attribute debug_level. The
1460 attribute takes the same bitmask as the debug module parameter above.
1463 Force loading of module
1464 -----------------------
1466 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1467 the module parameter force_load=1. Regardless of whether this works or
1468 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1471 Sysfs interface changelog:
1473 0x000100: Initial sysfs support, as a single platform driver and
1475 0x000200: Hot key support for 32 hot keys, and radio slider switch
1477 0x010000: Hot keys are now handled by default over the input
1478 layer, the radio switch generates input event EV_RADIO,
1479 and the driver enables hot key handling by default in
1482 0x020000: ABI fix: added a separate hwmon platform device and
1483 driver, which must be located by name (thinkpad)
1484 and the hwmon class for libsensors4 (lm-sensors 3)
1485 compatibility. Moved all hwmon attributes to this
1486 new platform device.
1488 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1489 support. If you must, use it to know you should not
1490 start a userspace NVRAM poller (allows to detect when
1491 NVRAM is compiled out by the user because it is
1492 unneeded/undesired in the first place).
1493 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1494 and proper hotkey_mask semantics (version 8 of the
1495 NVRAM polling patch). Some development snapshots of
1496 0.18 had an earlier version that did strange things
1499 0x020200: Add poll()/select() support to the following attributes:
1500 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1502 0x020300: hotkey enable/disable support removed, attributes
1503 hotkey_bios_enabled and hotkey_enable deprecated and
1506 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1507 to not exist in a given model are not registered with
1508 the LED sysfs class anymore.
1510 0x020500: Updated hotkey driver, hotkey_mask is always available
1511 and it is always able to disable hot keys. Very old
1512 thinkpads are properly supported. hotkey_bios_mask
1513 is deprecated and marked for removal.
1515 0x020600: Marker for backlight change event support.
1517 0x020700: Support for mute-only mixers.
1518 Volume control in read-only mode by default.
1519 Marker for ALSA mixer support.