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.
25 The features currently supported are the following (see below for
26 detailed description):
29 - Bluetooth enable and disable
30 - video output switching, expansion control
31 - ThinkLight on and off
32 - limited docking and undocking
38 - Experimental: embedded controller register dump
39 - LCD brightness control
41 - Fan control and monitoring: fan speed, fan enable/disable
42 - Experimental: WAN enable and disable
44 A compatibility table by model and feature is maintained on the web
45 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
46 reports, especially if they add to or correct the compatibility table.
47 Please include the following information in your report:
50 - a copy of your DSDT, from /proc/acpi/dsdt
51 - a copy of the output of dmidecode, with serial numbers
53 - which driver features work and which don't
54 - the observed behavior of non-working features
56 Any other comments or patches are also more than welcome.
62 If you are compiling this driver as included in the Linux kernel
63 sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
64 enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
65 thinkpad-specific bay functionality.
70 The driver exports two different interfaces to userspace, which can be
71 used to access the features it provides. One is a legacy procfs-based
72 interface, which will be removed at some time in the distant future.
73 The other is a new sysfs-based interface which is not complete yet.
75 The procfs interface creates the /proc/acpi/ibm directory. There is a
76 file under that directory for each feature it supports. The procfs
77 interface is mostly frozen, and will change very little if at all: it
78 will not be extended to add any new functionality in the driver, instead
79 all new functionality will be implemented on the sysfs interface.
81 The sysfs interface tries to blend in the generic Linux sysfs subsystems
82 and classes as much as possible. Since some of these subsystems are not
83 yet ready or stabilized, it is expected that this interface will change,
84 and any and all userspace programs must deal with it.
87 Notes about the sysfs interface:
89 Unlike what was done with the procfs interface, correctness when talking
90 to the sysfs interfaces will be enforced, as will correctness in the
91 thinkpad-acpi's implementation of sysfs interfaces.
93 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
94 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
95 maximum correctness, even if that means changing an interface in
96 non-compatible ways. As these interfaces mature both in the kernel and
97 in thinkpad-acpi, such changes should become quite rare.
99 Applications interfacing to the thinkpad-acpi sysfs interfaces must
100 follow all sysfs guidelines and correctly process all errors (the sysfs
101 interface makes extensive use of errors). File descriptors and open /
102 close operations to the sysfs inodes must also be properly implemented.
104 The version of thinkpad-acpi's sysfs interface is exported by the driver
105 as a driver attribute (see below).
107 Sysfs driver attributes are on the driver's sysfs attribute space,
108 for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
109 /sys/bus/platform/drivers/thinkpad_hwmon/
111 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
112 space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
114 Sysfs device attributes for the sensors and fan are on the
115 thinkpad_hwmon device's sysfs attribute space, but you should locate it
116 looking for a hwmon device with the name attribute of "thinkpad".
121 procfs: /proc/acpi/ibm/driver
122 sysfs driver attribute: version
124 The driver name and version. No commands can be written to this file.
126 Sysfs interface version
127 -----------------------
129 sysfs driver attribute: interface_version
131 Version of the thinkpad-acpi sysfs interface, as an unsigned long
132 (output in hex format: 0xAAAABBCC), where:
133 AAAA - major revision
137 The sysfs interface version changelog for the driver can be found at the
138 end of this document. Changes to the sysfs interface done by the kernel
139 subsystems are not documented here, nor are they tracked by this
142 Changes to the thinkpad-acpi sysfs interface are only considered
143 non-experimental when they are submitted to Linux mainline, at which
144 point the changes in this interface are documented and interface_version
145 may be updated. If you are using any thinkpad-acpi features not yet
146 sent to mainline for merging, you do so on your own risk: these features
147 may disappear, or be implemented in a different and incompatible way by
148 the time they are merged in Linux mainline.
150 Changes that are backwards-compatible by nature (e.g. the addition of
151 attributes that do not change the way the other attributes work) do not
152 always warrant an update of interface_version. Therefore, one must
153 expect that an attribute might not be there, and deal with it properly
154 (an attribute not being there *is* a valid way to make it clear that a
155 feature is not available in sysfs).
160 procfs: /proc/acpi/ibm/hotkey
161 sysfs device attribute: hotkey_*
163 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
164 some important events and also keyboard hot key presses to the operating
165 system. Enabling the hotkey functionality of thinkpad-acpi signals the
166 firmware that such a driver is present, and modifies how the ThinkPad
167 firmware will behave in many situations.
169 The driver enables the hot key feature automatically when loaded. The
170 feature can later be disabled and enabled back at runtime. The driver
171 will also restore the hot key feature to its previous state and mask
174 When the hotkey feature is enabled and the hot key mask is set (see
175 below), the driver will report HKEY events in the following format:
177 ibm/hotkey HKEY 00000080 0000xxxx
179 Some of these events refer to hot key presses, but not all.
181 The driver will generate events over the input layer for hot keys and
182 radio switches, and over the ACPI netlink layer for other events. The
183 input layer support accepts the standard IOCTLs to remap the keycodes
184 assigned to each hot key.
186 The hot key bit mask allows some control over which hot keys generate
187 events. If a key is "masked" (bit set to 0 in the mask), the firmware
188 will handle it. If it is "unmasked", it signals the firmware that
189 thinkpad-acpi would prefer to handle it, if the firmware would be so
190 kind to allow it (and it often doesn't!).
192 Not all bits in the mask can be modified. Not all bits that can be
193 modified do anything. Not all hot keys can be individually controlled
194 by the mask. Some models do not support the mask at all, and in those
195 models, hot keys cannot be controlled individually. The behaviour of
196 the mask is, therefore, highly dependent on the ThinkPad model.
198 Note that unmasking some keys prevents their default behavior. For
199 example, if Fn+F5 is unmasked, that key will no longer enable/disable
202 Note also that not all Fn key combinations are supported through ACPI.
203 For example, on the X40, the brightness, volume and "Access IBM" buttons
204 do not generate ACPI events even with this driver. They *can* be used
205 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
209 The following commands can be written to the /proc/acpi/ibm/hotkey file:
211 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
212 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
213 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
214 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
215 ... any other 8-hex-digit mask ...
216 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
218 The procfs interface does not support NVRAM polling control. So as to
219 maintain maximum bug-to-bug compatibility, it does not report any masks,
220 nor does it allow one to manipulate the hot key mask when the firmware
221 does not support masks at all, even if NVRAM polling is in use.
226 Returns the status of the hot keys feature when
227 thinkpad-acpi was loaded. Upon module unload, the hot
228 key feature status will be restored to this value.
230 0: hot keys were disabled
231 1: hot keys were enabled (unusual)
234 Returns the hot keys mask when thinkpad-acpi was loaded.
235 Upon module unload, the hot keys mask will be restored
239 Enables/disables the hot keys feature in the ACPI
240 firmware, and reports current status of the hot keys
241 feature. Has no effect on the NVRAM hot key polling
244 0: disables the hot keys feature / feature disabled
245 1: enables the hot keys feature / feature enabled
248 bit mask to enable driver-handling (and depending on
249 the firmware, ACPI event generation) for each hot key
250 (see above). Returns the current status of the hot keys
251 mask, and allows one to modify it.
253 Note: when NVRAM polling is active, the firmware mask
254 will be different from the value returned by
255 hotkey_mask. The driver will retain enabled bits for
256 hotkeys that are under NVRAM polling even if the
257 firmware refuses them, and will not set these bits on
258 the firmware hot key mask.
261 bit mask that should enable event reporting for all
262 supported hot keys, when echoed to hotkey_mask above.
263 Unless you know which events need to be handled
264 passively (because the firmware *will* handle them
265 anyway), do *not* use hotkey_all_mask. Use
266 hotkey_recommended_mask, instead. You have been warned.
268 hotkey_recommended_mask:
269 bit mask that should enable event reporting for all
270 supported hot keys, except those which are always
271 handled by the firmware anyway. Echo it to
272 hotkey_mask above, to use.
275 bit mask that selects which hot keys will the driver
276 poll the NVRAM for. This is auto-detected by the driver
277 based on the capabilities reported by the ACPI firmware,
278 but it can be overridden at runtime.
280 Hot keys whose bits are set in both hotkey_source_mask
281 and also on hotkey_mask are polled for in NVRAM. Only a
282 few hot keys are available through CMOS NVRAM polling.
284 Warning: when in NVRAM mode, the volume up/down/mute
285 keys are synthesized according to changes in the mixer,
286 so you have to use volume up or volume down to unmute,
287 as per the ThinkPad volume mixer user interface. When
288 in ACPI event mode, volume up/down/mute are reported as
289 separate events, but this behaviour may be corrected in
290 future releases of this driver, in which case the
291 ThinkPad volume mixer user interface semantics will be
295 frequency in Hz for hot key polling. It must be between
296 0 and 25 Hz. Polling is only carried out when strictly
299 Setting hotkey_poll_freq to zero disables polling, and
300 will cause hot key presses that require NVRAM polling
301 to never be reported.
303 Setting hotkey_poll_freq too low will cause repeated
304 pressings of the same hot key to be misreported as a
305 single key press, or to not even be detected at all.
306 The recommended polling frequency is 10Hz.
309 If the ThinkPad has a hardware radio switch, this
310 attribute will read 0 if the switch is in the "radios
311 disabled" position, and 1 if the switch is in the
312 "radios enabled" position.
314 This attribute has poll()/select() support.
317 If the ThinkPad has tablet capabilities, this attribute
318 will read 0 if the ThinkPad is in normal mode, and
319 1 if the ThinkPad is in tablet mode.
321 This attribute has poll()/select() support.
324 Returns the state of the procfs ACPI event report mode
325 filter for hot keys. If it is set to 1 (the default),
326 all hot key presses are reported both through the input
327 layer and also as ACPI events through procfs (but not
328 through netlink). If it is set to 2, hot key presses
329 are reported only through the input layer.
331 This attribute is read-only in kernels 2.6.23 or later,
332 and read-write on earlier kernels.
334 May return -EPERM (write access locked out by module
335 parameter) or -EACCES (read-only).
338 Set to 1 if the system is waking up because the user
339 requested a bay ejection. Set to 2 if the system is
340 waking up because the user requested the system to
341 undock. Set to zero for normal wake-ups or wake-ups
342 due to unknown reasons.
344 This attribute has poll()/select() support.
346 wakeup_hotunplug_complete:
347 Set to 1 if the system was waken up because of an
348 undock or bay ejection request, and that request
349 was successfully completed. At this point, it might
350 be useful to send the system back to sleep, at the
351 user's choice. Refer to HKEY events 0x4003 and
354 This attribute has poll()/select() support.
358 A Hot key is mapped to a single input layer EV_KEY event, possibly
359 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
360 code. An EV_SYN event will always be generated to mark the end of the
363 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
364 used as a helper to remap keys, only. They are particularly useful when
365 remapping KEY_UNKNOWN keys.
367 The events are available in an input device, with the following id:
370 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
371 0x17aa (PCI_VENDOR_ID_LENOVO)
372 product: 0x5054 ("TP")
375 The version will have its LSB incremented if the keymap changes in a
376 backwards-compatible way. The MSB shall always be 0x41 for this input
377 device. If the MSB is not 0x41, do not use the device as described in
378 this section, as it is either something else (e.g. another input device
379 exported by a thinkpad driver, such as HDAPS) or its functionality has
380 been changed in a non-backwards compatible way.
382 Adding other event types for other functionalities shall be considered a
383 backwards-compatible change for this input device.
385 Thinkpad-acpi Hot Key event map (version 0x4101):
391 0x1002 0x01 FN+F2 IBM: battery (rare)
394 0x1003 0x02 FN+F3 Many IBM models always report
395 this hot key, even with hot keys
396 disabled or with Fn+F3 masked
401 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
402 semantics, i.e. sleep-to-RAM).
403 It is always generate some kind
404 of event, either the hot key
405 event or a ACPI sleep button
406 event. The firmware may
407 refuse to generate further FN+F4
408 key presses until a S3 or S4 ACPI
409 sleep cycle is performed or some
412 0x1005 0x04 FN+F5 Radio. Enables/disables
413 the internal Bluetooth hardware
414 and W-WAN card if left in control
415 of the firmware. Does not affect
417 Should be used to turn on/off all
418 radios (Bluetooth+W-WAN+WLAN),
423 0x1007 0x06 FN+F7 Video output cycle.
424 Do you feel lucky today?
426 0x1008 0x07 FN+F8 IBM: toggle screen expand
427 Lenovo: configure UltraNav
433 0x100C 0x0B FN+F12 Sleep to disk. You are always
434 supposed to handle it yourself,
435 either through the ACPI event,
436 or through a hotkey event.
437 The firmware may refuse to
438 generate further FN+F4 key
439 press events until a S3 or S4
440 ACPI sleep cycle is performed,
443 0x100D 0x0C FN+BACKSPACE -
444 0x100E 0x0D FN+INSERT -
445 0x100F 0x0E FN+DELETE -
447 0x1010 0x0F FN+HOME Brightness up. This key is
448 always handled by the firmware
449 in IBM ThinkPads, even when
450 unmasked. Just leave it alone.
451 For Lenovo ThinkPads with a new
452 BIOS, it has to be handled either
453 by the ACPI OSI, or by userspace.
454 0x1011 0x10 FN+END Brightness down. See brightness
457 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
458 always handled by the firmware,
461 0x1013 0x12 FN+PGDOWN -
463 0x1014 0x13 FN+SPACE Zoom key
465 0x1015 0x14 VOLUME UP Internal mixer volume up. This
466 key is always handled by the
467 firmware, even when unmasked.
468 NOTE: Lenovo seems to be changing
470 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
471 key is always handled by the
472 firmware, even when unmasked.
473 NOTE: Lenovo seems to be changing
475 0x1017 0x16 MUTE Mute internal mixer. This
476 key is always handled by the
477 firmware, even when unmasked.
479 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
485 The ThinkPad firmware does not allow one to differentiate when most hot
486 keys are pressed or released (either that, or we don't know how to, yet).
487 For these keys, the driver generates a set of events for a key press and
488 immediately issues the same set of events for a key release. It is
489 unknown by the driver if the ThinkPad firmware triggered these events on
490 hot key press or release, but the firmware will do it for either one, not
493 If a key is mapped to KEY_RESERVED, it generates no input events at all.
494 If a key is mapped to KEY_UNKNOWN, it generates an input event that
495 includes an scan code. If a key is mapped to anything else, it will
496 generate input device EV_KEY events.
498 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
501 SW_RADIO T60 and later hardare rfkill rocker switch
502 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
504 Non hot-key ACPI HKEY event map:
507 0x5009 Tablet swivel: switched to tablet mode
508 0x500A Tablet swivel: switched to normal mode
509 0x7000 Radio Switch may have changed state
511 The above events are not propagated by the driver, except for legacy
512 compatibility purposes when hotkey_report_mode is set to 1.
514 0x2304 System is waking up from suspend to undock
515 0x2305 System is waking up from suspend to eject bay
516 0x2404 System is waking up from hibernation to undock
517 0x2405 System is waking up from hibernation to eject bay
519 The above events are never propagated by the driver.
521 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
522 0x4003 Undocked (see 0x2x04), can sleep again
523 0x500B Tablet pen inserted into its storage bay
524 0x500C Tablet pen removed from its storage bay
525 0x5010 Brightness level changed (newer Lenovo BIOSes)
527 The above events are propagated by the driver.
531 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
532 supported the input layer, and sent events over the procfs ACPI event
535 To avoid sending duplicate events over the input layer and the ACPI
536 event interface, thinkpad-acpi 0.16 implements a module parameter
537 (hotkey_report_mode), and also a sysfs device attribute with the same
540 Make no mistake here: userspace is expected to switch to using the input
541 layer interface of thinkpad-acpi, together with the ACPI netlink event
542 interface in kernels 2.6.23 and later, or with the ACPI procfs event
543 interface in kernels 2.6.22 and earlier.
545 If no hotkey_report_mode module parameter is specified (or it is set to
546 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
547 and earlier, also allows one to change the hotkey_report_mode through
548 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
549 interface is available, hotkey_report_mode cannot be changed through
550 sysfs (it is read-only).
552 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
553 be changed later through sysfs (any writes will return -EPERM to signal
554 that hotkey_report_mode was locked. On 2.6.23 and later, where
555 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
557 hotkey_report_mode set to 1 makes the driver export through the procfs
558 ACPI event interface all hot key presses (which are *also* sent to the
559 input layer). This is a legacy compatibility behaviour, and it is also
560 the default mode of operation for the driver.
562 hotkey_report_mode set to 2 makes the driver filter out the hot key
563 presses from the procfs ACPI event interface, so these events will only
564 be sent through the input layer. Userspace that has been updated to use
565 the thinkpad-acpi input layer interface should set hotkey_report_mode to
568 Hot key press events are never sent to the ACPI netlink event interface.
569 Really up-to-date userspace under kernel 2.6.23 and later is to use the
570 netlink interface and the input layer interface, and don't bother at all
571 with hotkey_report_mode.
577 procfs: /proc/acpi/ibm/bluetooth
578 sysfs device attribute: bluetooth_enable
580 This feature shows the presence and current state of a ThinkPad
581 Bluetooth device in the internal ThinkPad CDC slot.
585 If Bluetooth is installed, the following commands can be used:
587 echo enable > /proc/acpi/ibm/bluetooth
588 echo disable > /proc/acpi/ibm/bluetooth
592 If the Bluetooth CDC card is installed, it can be enabled /
593 disabled through the "bluetooth_enable" thinkpad-acpi device
594 attribute, and its current status can also be queried.
597 0: disables Bluetooth / Bluetooth is disabled
598 1: enables Bluetooth / Bluetooth is enabled.
600 Note: this interface will be probably be superseded by the
601 generic rfkill class, so it is NOT to be considered stable yet.
603 Video output control -- /proc/acpi/ibm/video
604 --------------------------------------------
606 This feature allows control over the devices used for video output -
607 LCD, CRT or DVI (if available). The following commands are available:
609 echo lcd_enable > /proc/acpi/ibm/video
610 echo lcd_disable > /proc/acpi/ibm/video
611 echo crt_enable > /proc/acpi/ibm/video
612 echo crt_disable > /proc/acpi/ibm/video
613 echo dvi_enable > /proc/acpi/ibm/video
614 echo dvi_disable > /proc/acpi/ibm/video
615 echo auto_enable > /proc/acpi/ibm/video
616 echo auto_disable > /proc/acpi/ibm/video
617 echo expand_toggle > /proc/acpi/ibm/video
618 echo video_switch > /proc/acpi/ibm/video
620 Each video output device can be enabled or disabled individually.
621 Reading /proc/acpi/ibm/video shows the status of each device.
623 Automatic video switching can be enabled or disabled. When automatic
624 video switching is enabled, certain events (e.g. opening the lid,
625 docking or undocking) cause the video output device to change
626 automatically. While this can be useful, it also causes flickering
627 and, on the X40, video corruption. By disabling automatic switching,
628 the flickering or video corruption can be avoided.
630 The video_switch command cycles through the available video outputs
631 (it simulates the behavior of Fn-F7).
633 Video expansion can be toggled through this feature. This controls
634 whether the display is expanded to fill the entire LCD screen when a
635 mode with less than full resolution is used. Note that the current
636 video expansion status cannot be determined through this feature.
638 Note that on many models (particularly those using Radeon graphics
639 chips) the X driver configures the video card in a way which prevents
640 Fn-F7 from working. This also disables the video output switching
641 features of this driver, as it uses the same ACPI methods as
642 Fn-F7. Video switching on the console should still work.
644 UPDATE: There's now a patch for the X.org Radeon driver which
645 addresses this issue. Some people are reporting success with the patch
646 while others are still having problems. For more information:
648 https://bugs.freedesktop.org/show_bug.cgi?id=2000
650 ThinkLight control -- /proc/acpi/ibm/light
651 ------------------------------------------
653 The current status of the ThinkLight can be found in this file. A few
654 models which do not make the status available will show it as
655 "unknown". The available commands are:
657 echo on > /proc/acpi/ibm/light
658 echo off > /proc/acpi/ibm/light
660 Docking / undocking -- /proc/acpi/ibm/dock
661 ------------------------------------------
663 Docking and undocking (e.g. with the X4 UltraBase) requires some
664 actions to be taken by the operating system to safely make or break
665 the electrical connections with the dock.
667 The docking feature of this driver generates the following ACPI events:
669 ibm/dock GDCK 00000003 00000001 -- eject request
670 ibm/dock GDCK 00000003 00000002 -- undocked
671 ibm/dock GDCK 00000000 00000003 -- docked
673 NOTE: These events will only be generated if the laptop was docked
674 when originally booted. This is due to the current lack of support for
675 hot plugging of devices in the Linux ACPI framework. If the laptop was
676 booted while not in the dock, the following message is shown in the
679 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
681 In this case, no dock-related events are generated but the dock and
682 undock commands described below still work. They can be executed
683 manually or triggered by Fn key combinations (see the example acpid
684 configuration files included in the driver tarball package available
687 When the eject request button on the dock is pressed, the first event
688 above is generated. The handler for this event should issue the
691 echo undock > /proc/acpi/ibm/dock
693 After the LED on the dock goes off, it is safe to eject the laptop.
694 Note: if you pressed this key by mistake, go ahead and eject the
695 laptop, then dock it back in. Otherwise, the dock may not function as
698 When the laptop is docked, the third event above is generated. The
699 handler for this event should issue the following command to fully
702 echo dock > /proc/acpi/ibm/dock
704 The contents of the /proc/acpi/ibm/dock file shows the current status
705 of the dock, as provided by the ACPI framework.
707 The docking support in this driver does not take care of enabling or
708 disabling any other devices you may have attached to the dock. For
709 example, a CD drive plugged into the UltraBase needs to be disabled or
710 enabled separately. See the provided example acpid configuration files
711 for how this can be accomplished.
713 There is no support yet for PCI devices that may be attached to a
714 docking station, e.g. in the ThinkPad Dock II. The driver currently
715 does not recognize, enable or disable such devices. This means that
716 the only docking stations currently supported are the X-series
717 UltraBase docks and "dumb" port replicators like the Mini Dock (the
718 latter don't need any ACPI support, actually).
720 UltraBay eject -- /proc/acpi/ibm/bay
721 ------------------------------------
723 Inserting or ejecting an UltraBay device requires some actions to be
724 taken by the operating system to safely make or break the electrical
725 connections with the device.
727 This feature generates the following ACPI events:
729 ibm/bay MSTR 00000003 00000000 -- eject request
730 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
732 NOTE: These events will only be generated if the UltraBay was present
733 when the laptop was originally booted (on the X series, the UltraBay
734 is in the dock, so it may not be present if the laptop was undocked).
735 This is due to the current lack of support for hot plugging of devices
736 in the Linux ACPI framework. If the laptop was booted without the
737 UltraBay, the following message is shown in the logs:
739 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
741 In this case, no bay-related events are generated but the eject
742 command described below still works. It can be executed manually or
743 triggered by a hot key combination.
745 Sliding the eject lever generates the first event shown above. The
746 handler for this event should take whatever actions are necessary to
747 shut down the device in the UltraBay (e.g. call idectl), then issue
748 the following command:
750 echo eject > /proc/acpi/ibm/bay
752 After the LED on the UltraBay goes off, it is safe to pull out the
755 When the eject lever is inserted, the second event above is
756 generated. The handler for this event should take whatever actions are
757 necessary to enable the UltraBay device (e.g. call idectl).
759 The contents of the /proc/acpi/ibm/bay file shows the current status
760 of the UltraBay, as provided by the ACPI framework.
762 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
763 this feature, you need to supply the experimental=1 parameter when
766 These models do not have a button near the UltraBay device to request
767 a hot eject but rather require the laptop to be put to sleep
768 (suspend-to-ram) before the bay device is ejected or inserted).
769 The sequence of steps to eject the device is as follows:
771 echo eject > /proc/acpi/ibm/bay
772 put the ThinkPad to sleep
775 cat /proc/acpi/ibm/bay should show that the drive was removed
777 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
778 supported. Use "eject2" instead of "eject" for the second bay.
780 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
781 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
786 procfs: /proc/acpi/ibm/cmos
787 sysfs device attribute: cmos_command
789 This feature is mostly used internally by the ACPI firmware to keep the legacy
790 CMOS NVRAM bits in sync with the current machine state, and to record this
791 state so that the ThinkPad will retain such settings across reboots.
793 Some of these commands actually perform actions in some ThinkPad models, but
794 this is expected to disappear more and more in newer models. As an example, in
795 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
796 real, but commands 0 to 2 don't control the mixer anymore (they have been
797 phased out) and just update the NVRAM.
799 The range of valid cmos command numbers is 0 to 21, but not all have an
800 effect and the behavior varies from model to model. Here is the behavior
801 on the X40 (tpb is the ThinkPad Buttons utility):
803 0 - Related to "Volume down" key press
804 1 - Related to "Volume up" key press
805 2 - Related to "Mute on" key press
806 3 - Related to "Access IBM" key press
807 4 - Related to "LCD brightness up" key press
808 5 - Related to "LCD brightness down" key press
809 11 - Related to "toggle screen expansion" key press/function
810 12 - Related to "ThinkLight on"
811 13 - Related to "ThinkLight off"
812 14 - Related to "ThinkLight" key press (toggle ThinkLight)
814 The cmos command interface is prone to firmware split-brain problems, as
815 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
816 exported just as a debug tool.
818 LED control -- /proc/acpi/ibm/led
819 ---------------------------------
821 Some of the LED indicators can be controlled through this feature. The
822 available commands are:
824 echo '<led number> on' >/proc/acpi/ibm/led
825 echo '<led number> off' >/proc/acpi/ibm/led
826 echo '<led number> blink' >/proc/acpi/ibm/led
828 The <led number> range is 0 to 7. The set of LEDs that can be
829 controlled varies from model to model. Here is the mapping on the X40:
838 All of the above can be turned on and off and can be made to blink.
840 ACPI sounds -- /proc/acpi/ibm/beep
841 ----------------------------------
843 The BEEP method is used internally by the ACPI firmware to provide
844 audible alerts in various situations. This feature allows the same
845 sounds to be triggered manually.
847 The commands are non-negative integer numbers:
849 echo <number> >/proc/acpi/ibm/beep
851 The valid <number> range is 0 to 17. Not all numbers trigger sounds
852 and the sounds vary from model to model. Here is the behavior on the
855 0 - stop a sound in progress (but use 17 to stop 16)
856 2 - two beeps, pause, third beep ("low battery")
858 4 - high, followed by low-pitched beep ("unable")
860 6 - very high, followed by high-pitched beep ("AC/DC")
861 7 - high-pitched beep
862 9 - three short beeps
864 12 - low-pitched beep
865 15 - three high-pitched beeps repeating constantly, stop with 0
866 16 - one medium-pitched beep repeating constantly, stop with 17
872 procfs: /proc/acpi/ibm/thermal
873 sysfs device attributes: (hwmon "thinkpad") temp*_input
875 Most ThinkPads include six or more separate temperature sensors but only
876 expose the CPU temperature through the standard ACPI methods. This
877 feature shows readings from up to eight different sensors on older
878 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
880 For example, on the X40, a typical output may be:
881 temperatures: 42 42 45 41 36 -128 33 -128
883 On the T43/p, a typical output may be:
884 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
886 The mapping of thermal sensors to physical locations varies depending on
887 system-board model (and thus, on ThinkPad model).
889 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
890 tries to track down these locations for various models.
892 Most (newer?) models seem to follow this pattern:
895 2: (depends on model)
896 3: (depends on model)
898 5: Main battery: main sensor
899 6: Bay battery: main sensor
900 7: Main battery: secondary sensor
901 8: Bay battery: secondary sensor
902 9-15: (depends on model)
904 For the R51 (source: Thomas Gruber):
908 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
909 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
910 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
912 9: MCH (northbridge) to DRAM Bus
913 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
915 11: Power regulator, underside of system board, below F2 key
917 The A31 has a very atypical layout for the thermal sensors
918 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
920 2: Main Battery: main sensor
922 4: Bay Battery: main sensor
925 7: Main Battery: secondary sensor
926 8: Bay Battery: secondary sensor
930 Readings from sensors that are not available return -128.
931 No commands can be written to this file.
934 Sensors that are not available return the ENXIO error. This
935 status may change at runtime, as there are hotplug thermal
936 sensors, like those inside the batteries and docks.
938 thinkpad-acpi thermal sensors are reported through the hwmon
939 subsystem, and follow all of the hwmon guidelines at
943 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
944 ------------------------------------------------------------------------
946 This feature is marked EXPERIMENTAL because the implementation
947 directly accesses hardware registers and may not work as expected. USE
948 WITH CAUTION! To use this feature, you need to supply the
949 experimental=1 parameter when loading the module.
951 This feature dumps the values of 256 embedded controller
952 registers. Values which have changed since the last time the registers
953 were dumped are marked with a star:
955 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
956 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
957 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
958 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
959 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
960 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
961 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
962 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
963 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
964 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
965 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
966 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
967 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
968 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
969 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
970 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
971 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
972 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
974 This feature can be used to determine the register holding the fan
975 speed on some models. To do that, do the following:
977 - make sure the battery is fully charged
978 - make sure the fan is running
979 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
981 The first step makes sure various charging-related values don't
982 vary. The second ensures that the fan-related values do vary, since
983 the fan speed fluctuates a bit. The third will (hopefully) mark the
984 fan register with a star:
986 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
987 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
988 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
989 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
990 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
991 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
992 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
993 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
994 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
995 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
996 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
997 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
998 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
999 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1000 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1001 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1002 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1003 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1005 Another set of values that varies often is the temperature
1006 readings. Since temperatures don't change vary fast, you can take
1007 several quick dumps to eliminate them.
1009 You can use a similar method to figure out the meaning of other
1010 embedded controller registers - e.g. make sure nothing else changes
1011 except the charging or discharging battery to determine which
1012 registers contain the current battery capacity, etc. If you experiment
1013 with this, do send me your results (including some complete dumps with
1014 a description of the conditions when they were taken.)
1016 LCD brightness control
1017 ----------------------
1019 procfs: /proc/acpi/ibm/brightness
1020 sysfs backlight device "thinkpad_screen"
1022 This feature allows software control of the LCD brightness on ThinkPad
1023 models which don't have a hardware brightness slider.
1025 It has some limitations: the LCD backlight cannot be actually turned on or
1026 off by this interface, and in many ThinkPad models, the "dim while on
1027 battery" functionality will be enabled by the BIOS when this interface is
1028 used, and cannot be controlled.
1030 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1031 has eight brightness levels, ranging from 0 to 7. Some of the levels
1032 may not be distinct. Later Lenovo models that implement the ACPI
1033 display backlight brightness control methods have 16 levels, ranging
1036 There are two interfaces to the firmware for direct brightness control,
1037 EC and CMOS. To select which one should be used, use the
1038 brightness_mode module parameter: brightness_mode=1 selects EC mode,
1039 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
1040 and CMOS. The driver tries to auto-detect which interface to use.
1042 When display backlight brightness controls are available through the
1043 standard ACPI interface, it is best to use it instead of this direct
1044 ThinkPad-specific interface. The driver will disable its native
1045 backlight brightness control interface if it detects that the standard
1046 ACPI interface is available in the ThinkPad.
1048 The brightness_enable module parameter can be used to control whether
1049 the LCD brightness control feature will be enabled when available.
1050 brightness_enable=0 forces it to be disabled. brightness_enable=1
1051 forces it to be enabled when available, even if the standard ACPI
1052 interface is also available.
1056 The available commands are:
1058 echo up >/proc/acpi/ibm/brightness
1059 echo down >/proc/acpi/ibm/brightness
1060 echo 'level <level>' >/proc/acpi/ibm/brightness
1064 The interface is implemented through the backlight sysfs class, which is
1065 poorly documented at this time.
1067 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1068 it there will be the following attributes:
1071 Reads the maximum brightness the hardware can be set to.
1072 The minimum is always zero.
1075 Reads what brightness the screen is set to at this instant.
1078 Writes request the driver to change brightness to the
1079 given value. Reads will tell you what brightness the
1080 driver is trying to set the display to when "power" is set
1081 to zero and the display has not been dimmed by a kernel
1082 power management event.
1085 power management mode, where 0 is "display on", and 1 to 3
1086 will dim the display backlight to brightness level 0
1087 because thinkpad-acpi cannot really turn the backlight
1088 off. Kernel power management events can temporarily
1089 increase the current power management level, i.e. they can
1093 Volume control -- /proc/acpi/ibm/volume
1094 ---------------------------------------
1096 This feature allows volume control on ThinkPad models which don't have
1097 a hardware volume knob. The available commands are:
1099 echo up >/proc/acpi/ibm/volume
1100 echo down >/proc/acpi/ibm/volume
1101 echo mute >/proc/acpi/ibm/volume
1102 echo 'level <level>' >/proc/acpi/ibm/volume
1104 The <level> number range is 0 to 15 although not all of them may be
1105 distinct. The unmute the volume after the mute command, use either the
1106 up or down command (the level command will not unmute the volume).
1107 The current volume level and mute state is shown in the file.
1109 Fan control and monitoring: fan speed, fan enable/disable
1110 ---------------------------------------------------------
1112 procfs: /proc/acpi/ibm/fan
1113 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1115 sysfs hwmon driver attributes: fan_watchdog
1117 NOTE NOTE NOTE: fan control operations are disabled by default for
1118 safety reasons. To enable them, the module parameter "fan_control=1"
1119 must be given to thinkpad-acpi.
1121 This feature attempts to show the current fan speed, control mode and
1122 other fan data that might be available. The speed is read directly
1123 from the hardware registers of the embedded controller. This is known
1124 to work on later R, T, X and Z series ThinkPads but may show a bogus
1125 value on other models.
1129 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1130 stops the fan. The higher the level, the higher the fan speed, although
1131 adjacent levels often map to the same fan speed. 7 is the highest
1132 level, where the fan reaches the maximum recommended speed.
1134 Level "auto" means the EC changes the fan level according to some
1135 internal algorithm, usually based on readings from the thermal sensors.
1137 There is also a "full-speed" level, also known as "disengaged" level.
1138 In this level, the EC disables the speed-locked closed-loop fan control,
1139 and drives the fan as fast as it can go, which might exceed hardware
1140 limits, so use this level with caution.
1142 The fan usually ramps up or down slowly from one speed to another, and
1143 it is normal for the EC to take several seconds to react to fan
1144 commands. The full-speed level may take up to two minutes to ramp up to
1145 maximum speed, and in some ThinkPads, the tachometer readings go stale
1146 while the EC is transitioning to the full-speed level.
1148 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1149 monitoring all of the temperature sensor readings and you are ready to
1150 enable it if necessary to avoid overheating.
1152 An enabled fan in level "auto" may stop spinning if the EC decides the
1153 ThinkPad is cool enough and doesn't need the extra airflow. This is
1154 normal, and the EC will spin the fan up if the various thermal readings
1157 On the X40, this seems to depend on the CPU and HDD temperatures.
1158 Specifically, the fan is turned on when either the CPU temperature
1159 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1160 fan is turned off when the CPU temperature drops to 49 degrees and the
1161 HDD temperature drops to 41 degrees. These thresholds cannot
1162 currently be controlled.
1164 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1165 certain conditions are met. It will override any fan programming done
1166 through thinkpad-acpi.
1168 The thinkpad-acpi kernel driver can be programmed to revert the fan
1169 level to a safe setting if userspace does not issue one of the procfs
1170 fan commands: "enable", "disable", "level" or "watchdog", or if there
1171 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1172 set to 1, manual mode) within a configurable amount of time of up to
1173 120 seconds. This functionality is called fan safety watchdog.
1175 Note that the watchdog timer stops after it enables the fan. It will be
1176 rearmed again automatically (using the same interval) when one of the
1177 above mentioned fan commands is received. The fan watchdog is,
1178 therefore, not suitable to protect against fan mode changes made through
1179 means other than the "enable", "disable", and "level" procfs fan
1180 commands, or the hwmon fan control sysfs interface.
1184 The fan may be enabled or disabled with the following commands:
1186 echo enable >/proc/acpi/ibm/fan
1187 echo disable >/proc/acpi/ibm/fan
1189 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1190 will try to place it in a safe level if it is too slow or disabled.
1192 The fan level can be controlled with the command:
1194 echo 'level <level>' > /proc/acpi/ibm/fan
1196 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1197 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1198 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1199 "full-speed", and reports it as "disengaged" for backwards
1202 On the X31 and X40 (and ONLY on those models), the fan speed can be
1203 controlled to a certain degree. Once the fan is running, it can be
1204 forced to run faster or slower with the following command:
1206 echo 'speed <speed>' > /proc/acpi/ibm/fan
1208 The sustainable range of fan speeds on the X40 appears to be from about
1209 3700 to about 7350. Values outside this range either do not have any
1210 effect or the fan speed eventually settles somewhere in that range. The
1211 fan cannot be stopped or started with this command. This functionality
1212 is incomplete, and not available through the sysfs interface.
1214 To program the safety watchdog, use the "watchdog" command.
1216 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1218 If you want to disable the watchdog, use 0 as the interval.
1222 The sysfs interface follows the hwmon subsystem guidelines for the most
1223 part, and the exception is the fan safety watchdog.
1225 Writes to any of the sysfs attributes may return the EINVAL error if
1226 that operation is not supported in a given ThinkPad or if the parameter
1227 is out-of-bounds, and EPERM if it is forbidden. They may also return
1228 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1231 Features not yet implemented by the driver return ENOSYS.
1233 hwmon device attribute pwm1_enable:
1234 0: PWM offline (fan is set to full-speed mode)
1235 1: Manual PWM control (use pwm1 to set fan level)
1236 2: Hardware PWM control (EC "auto" mode)
1237 3: reserved (Software PWM control, not implemented yet)
1239 Modes 0 and 2 are not supported by all ThinkPads, and the
1240 driver is not always able to detect this. If it does know a
1241 mode is unsupported, it will return -EINVAL.
1243 hwmon device attribute pwm1:
1244 Fan level, scaled from the firmware values of 0-7 to the hwmon
1245 scale of 0-255. 0 means fan stopped, 255 means highest normal
1248 This attribute only commands the fan if pmw1_enable is set to 1
1249 (manual PWM control).
1251 hwmon device attribute fan1_input:
1252 Fan tachometer reading, in RPM. May go stale on certain
1253 ThinkPads while the EC transitions the PWM to offline mode,
1254 which can take up to two minutes. May return rubbish on older
1257 hwmon driver attribute fan_watchdog:
1258 Fan safety watchdog timer interval, in seconds. Minimum is
1259 1 second, maximum is 120 seconds. 0 disables the watchdog.
1261 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1263 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1264 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1265 would be the safest choice, though).
1271 procfs: /proc/acpi/ibm/wan
1272 sysfs device attribute: wwan_enable
1274 This feature is marked EXPERIMENTAL because the implementation
1275 directly accesses hardware registers and may not work as expected. USE
1276 WITH CAUTION! To use this feature, you need to supply the
1277 experimental=1 parameter when loading the module.
1279 This feature shows the presence and current state of a W-WAN (Sierra
1280 Wireless EV-DO) device.
1282 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1283 ThinkPad models which come with this module installed.
1287 If the W-WAN card is installed, the following commands can be used:
1289 echo enable > /proc/acpi/ibm/wan
1290 echo disable > /proc/acpi/ibm/wan
1294 If the W-WAN card is installed, it can be enabled /
1295 disabled through the "wwan_enable" thinkpad-acpi device
1296 attribute, and its current status can also be queried.
1299 0: disables WWAN card / WWAN card is disabled
1300 1: enables WWAN card / WWAN card is enabled.
1302 Note: this interface will be probably be superseded by the
1303 generic rfkill class, so it is NOT to be considered stable yet.
1305 Multiple Commands, Module Parameters
1306 ------------------------------------
1308 Multiple commands can be written to the proc files in one shot by
1309 separating them with commas, for example:
1311 echo enable,0xffff > /proc/acpi/ibm/hotkey
1312 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1314 Commands can also be specified when loading the thinkpad-acpi module,
1317 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1319 Enabling debugging output
1320 -------------------------
1322 The module takes a debug parameter which can be used to selectively
1323 enable various classes of debugging output, for example:
1325 modprobe thinkpad_acpi debug=0xffff
1327 will enable all debugging output classes. It takes a bitmask, so
1328 to enable more than one output class, just add their values.
1330 Debug bitmask Description
1331 0x0001 Initialization and probing
1334 There is also a kernel build option to enable more debugging
1335 information, which may be necessary to debug driver problems.
1337 The level of debugging information output by the driver can be changed
1338 at runtime through sysfs, using the driver attribute debug_level. The
1339 attribute takes the same bitmask as the debug module parameter above.
1341 Force loading of module
1342 -----------------------
1344 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1345 the module parameter force_load=1. Regardless of whether this works or
1346 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1349 Sysfs interface changelog:
1351 0x000100: Initial sysfs support, as a single platform driver and
1353 0x000200: Hot key support for 32 hot keys, and radio slider switch
1355 0x010000: Hot keys are now handled by default over the input
1356 layer, the radio switch generates input event EV_RADIO,
1357 and the driver enables hot key handling by default in
1360 0x020000: ABI fix: added a separate hwmon platform device and
1361 driver, which must be located by name (thinkpad)
1362 and the hwmon class for libsensors4 (lm-sensors 3)
1363 compatibility. Moved all hwmon attributes to this
1364 new platform device.
1366 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1367 support. If you must, use it to know you should not
1368 start an userspace NVRAM poller (allows to detect when
1369 NVRAM is compiled out by the user because it is
1370 unneeded/undesired in the first place).
1371 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1372 and proper hotkey_mask semantics (version 8 of the
1373 NVRAM polling patch). Some development snapshots of
1374 0.18 had an earlier version that did strange things
1377 0x020200: Add poll()/select() support to the following attributes:
1378 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
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