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 comunicating
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, higly 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 semanthics 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" postition, and 1 if the switch is in the
312 "radios enabled" position.
315 Returns the state of the procfs ACPI event report mode
316 filter for hot keys. If it is set to 1 (the default),
317 all hot key presses are reported both through the input
318 layer and also as ACPI events through procfs (but not
319 through netlink). If it is set to 2, hot key presses
320 are reported only through the input layer.
322 This attribute is read-only in kernels 2.6.23 or later,
323 and read-write on earlier kernels.
325 May return -EPERM (write access locked out by module
326 parameter) or -EACCES (read-only).
329 Set to 1 if the system is waking up because the user
330 requested a bay ejection. Set to 2 if the system is
331 waking up because the user requested the system to
332 undock. Set to zero for normal wake-ups or wake-ups
333 due to unknown reasons.
335 wakeup_hotunplug_complete:
336 Set to 1 if the system was waken up because of an
337 undock or bay ejection request, and that request
338 was sucessfully completed. At this point, it might
339 be useful to send the system back to sleep, at the
340 user's choice. Refer to HKEY events 0x4003 and
345 A Hot key is mapped to a single input layer EV_KEY event, possibly
346 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
347 code. An EV_SYN event will always be generated to mark the end of the
350 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
351 used as a helper to remap keys, only. They are particularly useful when
352 remapping KEY_UNKNOWN keys.
354 The events are available in an input device, with the following id:
357 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
358 0x17aa (PCI_VENDOR_ID_LENOVO)
359 product: 0x5054 ("TP")
362 The version will have its LSB incremented if the keymap changes in a
363 backwards-compatible way. The MSB shall always be 0x41 for this input
364 device. If the MSB is not 0x41, do not use the device as described in
365 this section, as it is either something else (e.g. another input device
366 exported by a thinkpad driver, such as HDAPS) or its functionality has
367 been changed in a non-backwards compatible way.
369 Adding other event types for other functionalities shall be considered a
370 backwards-compatible change for this input device.
372 Thinkpad-acpi Hot Key event map (version 0x4101):
378 0x1002 0x01 FN+F2 IBM: battery (rare)
381 0x1003 0x02 FN+F3 Many IBM models always report
382 this hot key, even with hot keys
383 disabled or with Fn+F3 masked
388 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
389 semanthics, i.e. sleep-to-RAM).
390 It is always generate some kind
391 of event, either the hot key
392 event or a ACPI sleep button
393 event. The firmware may
394 refuse to generate further FN+F4
395 key presses until a S3 or S4 ACPI
396 sleep cycle is performed or some
399 0x1005 0x04 FN+F5 Radio. Enables/disables
400 the internal BlueTooth hardware
401 and W-WAN card if left in control
402 of the firmware. Does not affect
404 Should be used to turn on/off all
405 radios (bluetooth+W-WAN+WLAN),
410 0x1007 0x06 FN+F7 Video output cycle.
411 Do you feel lucky today?
413 0x1008 0x07 FN+F8 IBM: toggle screen expand
414 Lenovo: configure ultranav
420 0x100C 0x0B FN+F12 Sleep to disk. You are always
421 supposed to handle it yourself,
422 either through the ACPI event,
423 or through a hotkey event.
424 The firmware may refuse to
425 generate further FN+F4 key
426 press events until a S3 or S4
427 ACPI sleep cycle is performed,
430 0x100D 0x0C FN+BACKSPACE -
431 0x100E 0x0D FN+INSERT -
432 0x100F 0x0E FN+DELETE -
434 0x1010 0x0F FN+HOME Brightness up. This key is
435 always handled by the firmware
436 in IBM ThinkPads, even when
437 unmasked. Just leave it alone.
438 For Lenovo ThinkPads with a new
439 BIOS, it has to be handled either
440 by the ACPI OSI, or by userspace.
441 0x1011 0x10 FN+END Brightness down. See brightness
444 0x1012 0x11 FN+PGUP Thinklight toggle. This key is
445 always handled by the firmware,
448 0x1013 0x12 FN+PGDOWN -
450 0x1014 0x13 FN+SPACE Zoom key
452 0x1015 0x14 VOLUME UP Internal mixer volume up. This
453 key is always handled by the
454 firmware, even when unmasked.
455 NOTE: Lenovo seems to be changing
457 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
458 key is always handled by the
459 firmware, even when unmasked.
460 NOTE: Lenovo seems to be changing
462 0x1017 0x16 MUTE Mute internal mixer. This
463 key is always handled by the
464 firmware, even when unmasked.
466 0x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
472 The ThinkPad firmware does not allow one to differentiate when most hot
473 keys are pressed or released (either that, or we don't know how to, yet).
474 For these keys, the driver generates a set of events for a key press and
475 immediately issues the same set of events for a key release. It is
476 unknown by the driver if the ThinkPad firmware triggered these events on
477 hot key press or release, but the firmware will do it for either one, not
480 If a key is mapped to KEY_RESERVED, it generates no input events at all.
481 If a key is mapped to KEY_UNKNOWN, it generates an input event that
482 includes an scan code. If a key is mapped to anything else, it will
483 generate input device EV_KEY events.
485 Non hot-key ACPI HKEY event map:
488 0x7000 Radio Switch may have changed state
490 The above events are not propagated by the driver, except for legacy
491 compatibility purposes when hotkey_report_mode is set to 1.
493 0x2304 System is waking up from suspend to undock
494 0x2305 System is waking up from suspend to eject bay
495 0x2404 System is waking up from hibernation to undock
496 0x2405 System is waking up from hibernation to eject bay
498 The above events are never propagated by the driver.
500 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
501 0x4003 Undocked (see 0x2x04), can sleep again
502 0x5010 Brightness level changed (newer Lenovo BIOSes)
504 The above events are propagated by the driver.
508 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
509 supported the input layer, and sent events over the procfs ACPI event
512 To avoid sending duplicate events over the input layer and the ACPI
513 event interface, thinkpad-acpi 0.16 implements a module parameter
514 (hotkey_report_mode), and also a sysfs device attribute with the same
517 Make no mistake here: userspace is expected to switch to using the input
518 layer interface of thinkpad-acpi, together with the ACPI netlink event
519 interface in kernels 2.6.23 and later, or with the ACPI procfs event
520 interface in kernels 2.6.22 and earlier.
522 If no hotkey_report_mode module parameter is specified (or it is set to
523 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
524 and earlier, also allows one to change the hotkey_report_mode through
525 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
526 interface is available, hotkey_report_mode cannot be changed through
527 sysfs (it is read-only).
529 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
530 be changed later through sysfs (any writes will return -EPERM to signal
531 that hotkey_report_mode was locked. On 2.6.23 and later, where
532 hotkey_report_mode cannot be changed at all, writes will return -EACES).
534 hotkey_report_mode set to 1 makes the driver export through the procfs
535 ACPI event interface all hot key presses (which are *also* sent to the
536 input layer). This is a legacy compatibility behaviour, and it is also
537 the default mode of operation for the driver.
539 hotkey_report_mode set to 2 makes the driver filter out the hot key
540 presses from the procfs ACPI event interface, so these events will only
541 be sent through the input layer. Userspace that has been updated to use
542 the thinkpad-acpi input layer interface should set hotkey_report_mode to
545 Hot key press events are never sent to the ACPI netlink event interface.
546 Really up-to-date userspace under kernel 2.6.23 and later is to use the
547 netlink interface and the input layer interface, and don't bother at all
548 with hotkey_report_mode.
554 procfs: /proc/acpi/ibm/bluetooth
555 sysfs device attribute: bluetooth_enable
557 This feature shows the presence and current state of a ThinkPad
558 Bluetooth device in the internal ThinkPad CDC slot.
562 If Bluetooth is installed, the following commands can be used:
564 echo enable > /proc/acpi/ibm/bluetooth
565 echo disable > /proc/acpi/ibm/bluetooth
569 If the Bluetooth CDC card is installed, it can be enabled /
570 disabled through the "bluetooth_enable" thinkpad-acpi device
571 attribute, and its current status can also be queried.
574 0: disables Bluetooth / Bluetooth is disabled
575 1: enables Bluetooth / Bluetooth is enabled.
577 Note: this interface will be probably be superseeded by the
578 generic rfkill class, so it is NOT to be considered stable yet.
580 Video output control -- /proc/acpi/ibm/video
581 --------------------------------------------
583 This feature allows control over the devices used for video output -
584 LCD, CRT or DVI (if available). The following commands are available:
586 echo lcd_enable > /proc/acpi/ibm/video
587 echo lcd_disable > /proc/acpi/ibm/video
588 echo crt_enable > /proc/acpi/ibm/video
589 echo crt_disable > /proc/acpi/ibm/video
590 echo dvi_enable > /proc/acpi/ibm/video
591 echo dvi_disable > /proc/acpi/ibm/video
592 echo auto_enable > /proc/acpi/ibm/video
593 echo auto_disable > /proc/acpi/ibm/video
594 echo expand_toggle > /proc/acpi/ibm/video
595 echo video_switch > /proc/acpi/ibm/video
597 Each video output device can be enabled or disabled individually.
598 Reading /proc/acpi/ibm/video shows the status of each device.
600 Automatic video switching can be enabled or disabled. When automatic
601 video switching is enabled, certain events (e.g. opening the lid,
602 docking or undocking) cause the video output device to change
603 automatically. While this can be useful, it also causes flickering
604 and, on the X40, video corruption. By disabling automatic switching,
605 the flickering or video corruption can be avoided.
607 The video_switch command cycles through the available video outputs
608 (it simulates the behavior of Fn-F7).
610 Video expansion can be toggled through this feature. This controls
611 whether the display is expanded to fill the entire LCD screen when a
612 mode with less than full resolution is used. Note that the current
613 video expansion status cannot be determined through this feature.
615 Note that on many models (particularly those using Radeon graphics
616 chips) the X driver configures the video card in a way which prevents
617 Fn-F7 from working. This also disables the video output switching
618 features of this driver, as it uses the same ACPI methods as
619 Fn-F7. Video switching on the console should still work.
621 UPDATE: There's now a patch for the X.org Radeon driver which
622 addresses this issue. Some people are reporting success with the patch
623 while others are still having problems. For more information:
625 https://bugs.freedesktop.org/show_bug.cgi?id=2000
627 ThinkLight control -- /proc/acpi/ibm/light
628 ------------------------------------------
630 The current status of the ThinkLight can be found in this file. A few
631 models which do not make the status available will show it as
632 "unknown". The available commands are:
634 echo on > /proc/acpi/ibm/light
635 echo off > /proc/acpi/ibm/light
637 Docking / undocking -- /proc/acpi/ibm/dock
638 ------------------------------------------
640 Docking and undocking (e.g. with the X4 UltraBase) requires some
641 actions to be taken by the operating system to safely make or break
642 the electrical connections with the dock.
644 The docking feature of this driver generates the following ACPI events:
646 ibm/dock GDCK 00000003 00000001 -- eject request
647 ibm/dock GDCK 00000003 00000002 -- undocked
648 ibm/dock GDCK 00000000 00000003 -- docked
650 NOTE: These events will only be generated if the laptop was docked
651 when originally booted. This is due to the current lack of support for
652 hot plugging of devices in the Linux ACPI framework. If the laptop was
653 booted while not in the dock, the following message is shown in the
656 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
658 In this case, no dock-related events are generated but the dock and
659 undock commands described below still work. They can be executed
660 manually or triggered by Fn key combinations (see the example acpid
661 configuration files included in the driver tarball package available
664 When the eject request button on the dock is pressed, the first event
665 above is generated. The handler for this event should issue the
668 echo undock > /proc/acpi/ibm/dock
670 After the LED on the dock goes off, it is safe to eject the laptop.
671 Note: if you pressed this key by mistake, go ahead and eject the
672 laptop, then dock it back in. Otherwise, the dock may not function as
675 When the laptop is docked, the third event above is generated. The
676 handler for this event should issue the following command to fully
679 echo dock > /proc/acpi/ibm/dock
681 The contents of the /proc/acpi/ibm/dock file shows the current status
682 of the dock, as provided by the ACPI framework.
684 The docking support in this driver does not take care of enabling or
685 disabling any other devices you may have attached to the dock. For
686 example, a CD drive plugged into the UltraBase needs to be disabled or
687 enabled separately. See the provided example acpid configuration files
688 for how this can be accomplished.
690 There is no support yet for PCI devices that may be attached to a
691 docking station, e.g. in the ThinkPad Dock II. The driver currently
692 does not recognize, enable or disable such devices. This means that
693 the only docking stations currently supported are the X-series
694 UltraBase docks and "dumb" port replicators like the Mini Dock (the
695 latter don't need any ACPI support, actually).
697 UltraBay eject -- /proc/acpi/ibm/bay
698 ------------------------------------
700 Inserting or ejecting an UltraBay device requires some actions to be
701 taken by the operating system to safely make or break the electrical
702 connections with the device.
704 This feature generates the following ACPI events:
706 ibm/bay MSTR 00000003 00000000 -- eject request
707 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
709 NOTE: These events will only be generated if the UltraBay was present
710 when the laptop was originally booted (on the X series, the UltraBay
711 is in the dock, so it may not be present if the laptop was undocked).
712 This is due to the current lack of support for hot plugging of devices
713 in the Linux ACPI framework. If the laptop was booted without the
714 UltraBay, the following message is shown in the logs:
716 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
718 In this case, no bay-related events are generated but the eject
719 command described below still works. It can be executed manually or
720 triggered by a hot key combination.
722 Sliding the eject lever generates the first event shown above. The
723 handler for this event should take whatever actions are necessary to
724 shut down the device in the UltraBay (e.g. call idectl), then issue
725 the following command:
727 echo eject > /proc/acpi/ibm/bay
729 After the LED on the UltraBay goes off, it is safe to pull out the
732 When the eject lever is inserted, the second event above is
733 generated. The handler for this event should take whatever actions are
734 necessary to enable the UltraBay device (e.g. call idectl).
736 The contents of the /proc/acpi/ibm/bay file shows the current status
737 of the UltraBay, as provided by the ACPI framework.
739 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
740 this feature, you need to supply the experimental=1 parameter when
743 These models do not have a button near the UltraBay device to request
744 a hot eject but rather require the laptop to be put to sleep
745 (suspend-to-ram) before the bay device is ejected or inserted).
746 The sequence of steps to eject the device is as follows:
748 echo eject > /proc/acpi/ibm/bay
749 put the ThinkPad to sleep
752 cat /proc/acpi/ibm/bay should show that the drive was removed
754 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
755 supported. Use "eject2" instead of "eject" for the second bay.
757 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
758 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
763 procfs: /proc/acpi/ibm/cmos
764 sysfs device attribute: cmos_command
766 This feature is mostly used internally by the ACPI firmware to keep the legacy
767 CMOS NVRAM bits in sync with the current machine state, and to record this
768 state so that the ThinkPad will retain such settings across reboots.
770 Some of these commands actually perform actions in some ThinkPad models, but
771 this is expected to disappear more and more in newer models. As an example, in
772 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
773 real, but commands 0 to 2 don't control the mixer anymore (they have been
774 phased out) and just update the NVRAM.
776 The range of valid cmos command numbers is 0 to 21, but not all have an
777 effect and the behavior varies from model to model. Here is the behavior
778 on the X40 (tpb is the ThinkPad Buttons utility):
780 0 - Related to "Volume down" key press
781 1 - Related to "Volume up" key press
782 2 - Related to "Mute on" key press
783 3 - Related to "Access IBM" key press
784 4 - Related to "LCD brightness up" key pess
785 5 - Related to "LCD brightness down" key press
786 11 - Related to "toggle screen expansion" key press/function
787 12 - Related to "ThinkLight on"
788 13 - Related to "ThinkLight off"
789 14 - Related to "ThinkLight" key press (toggle thinklight)
791 The cmos command interface is prone to firmware split-brain problems, as
792 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
793 exported just as a debug tool.
795 LED control -- /proc/acpi/ibm/led
796 ---------------------------------
798 Some of the LED indicators can be controlled through this feature. The
799 available commands are:
801 echo '<led number> on' >/proc/acpi/ibm/led
802 echo '<led number> off' >/proc/acpi/ibm/led
803 echo '<led number> blink' >/proc/acpi/ibm/led
805 The <led number> range is 0 to 7. The set of LEDs that can be
806 controlled varies from model to model. Here is the mapping on the X40:
815 All of the above can be turned on and off and can be made to blink.
817 ACPI sounds -- /proc/acpi/ibm/beep
818 ----------------------------------
820 The BEEP method is used internally by the ACPI firmware to provide
821 audible alerts in various situations. This feature allows the same
822 sounds to be triggered manually.
824 The commands are non-negative integer numbers:
826 echo <number> >/proc/acpi/ibm/beep
828 The valid <number> range is 0 to 17. Not all numbers trigger sounds
829 and the sounds vary from model to model. Here is the behavior on the
832 0 - stop a sound in progress (but use 17 to stop 16)
833 2 - two beeps, pause, third beep ("low battery")
835 4 - high, followed by low-pitched beep ("unable")
837 6 - very high, followed by high-pitched beep ("AC/DC")
838 7 - high-pitched beep
839 9 - three short beeps
841 12 - low-pitched beep
842 15 - three high-pitched beeps repeating constantly, stop with 0
843 16 - one medium-pitched beep repeating constantly, stop with 17
849 procfs: /proc/acpi/ibm/thermal
850 sysfs device attributes: (hwmon "thinkpad") temp*_input
852 Most ThinkPads include six or more separate temperature sensors but only
853 expose the CPU temperature through the standard ACPI methods. This
854 feature shows readings from up to eight different sensors on older
855 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
857 For example, on the X40, a typical output may be:
858 temperatures: 42 42 45 41 36 -128 33 -128
860 On the T43/p, a typical output may be:
861 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
863 The mapping of thermal sensors to physical locations varies depending on
864 system-board model (and thus, on ThinkPad model).
866 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
867 tries to track down these locations for various models.
869 Most (newer?) models seem to follow this pattern:
872 2: (depends on model)
873 3: (depends on model)
875 5: Main battery: main sensor
876 6: Bay battery: main sensor
877 7: Main battery: secondary sensor
878 8: Bay battery: secondary sensor
879 9-15: (depends on model)
881 For the R51 (source: Thomas Gruber):
885 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
886 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
887 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
889 9: MCH (northbridge) to DRAM Bus
890 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
892 11: Power regulator, underside of system board, below F2 key
894 The A31 has a very atypical layout for the thermal sensors
895 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
897 2: Main Battery: main sensor
899 4: Bay Battery: main sensor
902 7: Main Battery: secondary sensor
903 8: Bay Battery: secondary sensor
907 Readings from sensors that are not available return -128.
908 No commands can be written to this file.
911 Sensors that are not available return the ENXIO error. This
912 status may change at runtime, as there are hotplug thermal
913 sensors, like those inside the batteries and docks.
915 thinkpad-acpi thermal sensors are reported through the hwmon
916 subsystem, and follow all of the hwmon guidelines at
920 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
921 ------------------------------------------------------------------------
923 This feature is marked EXPERIMENTAL because the implementation
924 directly accesses hardware registers and may not work as expected. USE
925 WITH CAUTION! To use this feature, you need to supply the
926 experimental=1 parameter when loading the module.
928 This feature dumps the values of 256 embedded controller
929 registers. Values which have changed since the last time the registers
930 were dumped are marked with a star:
932 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
933 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
934 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
935 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
936 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
937 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
938 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
939 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
940 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
941 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
942 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
943 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
944 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
945 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
946 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
947 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
948 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
949 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
951 This feature can be used to determine the register holding the fan
952 speed on some models. To do that, do the following:
954 - make sure the battery is fully charged
955 - make sure the fan is running
956 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
958 The first step makes sure various charging-related values don't
959 vary. The second ensures that the fan-related values do vary, since
960 the fan speed fluctuates a bit. The third will (hopefully) mark the
961 fan register with a star:
963 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
964 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
965 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
966 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
967 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
968 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
969 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
970 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
971 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
972 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
973 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
974 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
975 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
976 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
977 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
978 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
979 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
980 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
982 Another set of values that varies often is the temperature
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.)
993 LCD brightness control
994 ----------------------
996 procfs: /proc/acpi/ibm/brightness
997 sysfs backlight device "thinkpad_screen"
999 This feature allows software control of the LCD brightness on ThinkPad
1000 models which don't have a hardware brightness slider.
1002 It has some limitations: the LCD backlight cannot be actually turned on or
1003 off by this interface, and in many ThinkPad models, the "dim while on
1004 battery" functionality will be enabled by the BIOS when this interface is
1005 used, and cannot be controlled.
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 There are two interfaces to the firmware for direct brightness control,
1014 EC and CMOS. To select which one should be used, use the
1015 brightness_mode module parameter: brightness_mode=1 selects EC mode,
1016 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
1017 and CMOS. The driver tries to autodetect which interface to use.
1019 When display backlight brightness controls are available through the
1020 standard ACPI interface, it is best to use it instead of this direct
1021 ThinkPad-specific interface. The driver will disable its native
1022 backlight brightness control interface if it detects that the standard
1023 ACPI interface is available in the ThinkPad.
1025 The brightness_enable module parameter can be used to control whether
1026 the LCD brightness control feature will be enabled when available.
1027 brightness_enable=0 forces it to be disabled. brightness_enable=1
1028 forces it to be enabled when available, even if the standard ACPI
1029 interface is also available.
1033 The available commands are:
1035 echo up >/proc/acpi/ibm/brightness
1036 echo down >/proc/acpi/ibm/brightness
1037 echo 'level <level>' >/proc/acpi/ibm/brightness
1041 The interface is implemented through the backlight sysfs class, which is
1042 poorly documented at this time.
1044 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1045 it there will be the following attributes:
1048 Reads the maximum brightness the hardware can be set to.
1049 The minimum is always zero.
1052 Reads what brightness the screen is set to at this instant.
1055 Writes request the driver to change brightness to the
1056 given value. Reads will tell you what brightness the
1057 driver is trying to set the display to when "power" is set
1058 to zero and the display has not been dimmed by a kernel
1059 power management event.
1062 power management mode, where 0 is "display on", and 1 to 3
1063 will dim the display backlight to brightness level 0
1064 because thinkpad-acpi cannot really turn the backlight
1065 off. Kernel power management events can temporarily
1066 increase the current power management level, i.e. they can
1070 Volume control -- /proc/acpi/ibm/volume
1071 ---------------------------------------
1073 This feature allows volume control on ThinkPad models which don't have
1074 a hardware volume knob. The available commands are:
1076 echo up >/proc/acpi/ibm/volume
1077 echo down >/proc/acpi/ibm/volume
1078 echo mute >/proc/acpi/ibm/volume
1079 echo 'level <level>' >/proc/acpi/ibm/volume
1081 The <level> number range is 0 to 15 although not all of them may be
1082 distinct. The unmute the volume after the mute command, use either the
1083 up or down command (the level command will not unmute the volume).
1084 The current volume level and mute state is shown in the file.
1086 Fan control and monitoring: fan speed, fan enable/disable
1087 ---------------------------------------------------------
1089 procfs: /proc/acpi/ibm/fan
1090 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1092 sysfs hwmon driver attributes: fan_watchdog
1094 NOTE NOTE NOTE: fan control operations are disabled by default for
1095 safety reasons. To enable them, the module parameter "fan_control=1"
1096 must be given to thinkpad-acpi.
1098 This feature attempts to show the current fan speed, control mode and
1099 other fan data that might be available. The speed is read directly
1100 from the hardware registers of the embedded controller. This is known
1101 to work on later R, T, X and Z series ThinkPads but may show a bogus
1102 value on other models.
1106 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1107 stops the fan. The higher the level, the higher the fan speed, although
1108 adjacent levels often map to the same fan speed. 7 is the highest
1109 level, where the fan reaches the maximum recommended speed.
1111 Level "auto" means the EC changes the fan level according to some
1112 internal algorithm, usually based on readings from the thermal sensors.
1114 There is also a "full-speed" level, also known as "disengaged" level.
1115 In this level, the EC disables the speed-locked closed-loop fan control,
1116 and drives the fan as fast as it can go, which might exceed hardware
1117 limits, so use this level with caution.
1119 The fan usually ramps up or down slowly from one speed to another, and
1120 it is normal for the EC to take several seconds to react to fan
1121 commands. The full-speed level may take up to two minutes to ramp up to
1122 maximum speed, and in some ThinkPads, the tachometer readings go stale
1123 while the EC is transitioning to the full-speed level.
1125 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1126 monitoring all of the temperature sensor readings and you are ready to
1127 enable it if necessary to avoid overheating.
1129 An enabled fan in level "auto" may stop spinning if the EC decides the
1130 ThinkPad is cool enough and doesn't need the extra airflow. This is
1131 normal, and the EC will spin the fan up if the various thermal readings
1134 On the X40, this seems to depend on the CPU and HDD temperatures.
1135 Specifically, the fan is turned on when either the CPU temperature
1136 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1137 fan is turned off when the CPU temperature drops to 49 degrees and the
1138 HDD temperature drops to 41 degrees. These thresholds cannot
1139 currently be controlled.
1141 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1142 certain conditions are met. It will override any fan programming done
1143 through thinkpad-acpi.
1145 The thinkpad-acpi kernel driver can be programmed to revert the fan
1146 level to a safe setting if userspace does not issue one of the procfs
1147 fan commands: "enable", "disable", "level" or "watchdog", or if there
1148 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1149 set to 1, manual mode) within a configurable amount of time of up to
1150 120 seconds. This functionality is called fan safety watchdog.
1152 Note that the watchdog timer stops after it enables the fan. It will be
1153 rearmed again automatically (using the same interval) when one of the
1154 above mentioned fan commands is received. The fan watchdog is,
1155 therefore, not suitable to protect against fan mode changes made through
1156 means other than the "enable", "disable", and "level" procfs fan
1157 commands, or the hwmon fan control sysfs interface.
1161 The fan may be enabled or disabled with the following commands:
1163 echo enable >/proc/acpi/ibm/fan
1164 echo disable >/proc/acpi/ibm/fan
1166 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1167 will try to place it in a safe level if it is too slow or disabled.
1169 The fan level can be controlled with the command:
1171 echo 'level <level>' > /proc/acpi/ibm/fan
1173 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1174 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1175 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1176 "full-speed", and reports it as "disengaged" for backwards
1179 On the X31 and X40 (and ONLY on those models), the fan speed can be
1180 controlled to a certain degree. Once the fan is running, it can be
1181 forced to run faster or slower with the following command:
1183 echo 'speed <speed>' > /proc/acpi/ibm/fan
1185 The sustainable range of fan speeds on the X40 appears to be from about
1186 3700 to about 7350. Values outside this range either do not have any
1187 effect or the fan speed eventually settles somewhere in that range. The
1188 fan cannot be stopped or started with this command. This functionality
1189 is incomplete, and not available through the sysfs interface.
1191 To program the safety watchdog, use the "watchdog" command.
1193 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1195 If you want to disable the watchdog, use 0 as the interval.
1199 The sysfs interface follows the hwmon subsystem guidelines for the most
1200 part, and the exception is the fan safety watchdog.
1202 Writes to any of the sysfs attributes may return the EINVAL error if
1203 that operation is not supported in a given ThinkPad or if the parameter
1204 is out-of-bounds, and EPERM if it is forbidden. They may also return
1205 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1208 Features not yet implemented by the driver return ENOSYS.
1210 hwmon device attribute pwm1_enable:
1211 0: PWM offline (fan is set to full-speed mode)
1212 1: Manual PWM control (use pwm1 to set fan level)
1213 2: Hardware PWM control (EC "auto" mode)
1214 3: reserved (Software PWM control, not implemented yet)
1216 Modes 0 and 2 are not supported by all ThinkPads, and the
1217 driver is not always able to detect this. If it does know a
1218 mode is unsupported, it will return -EINVAL.
1220 hwmon device attribute pwm1:
1221 Fan level, scaled from the firmware values of 0-7 to the hwmon
1222 scale of 0-255. 0 means fan stopped, 255 means highest normal
1225 This attribute only commands the fan if pmw1_enable is set to 1
1226 (manual PWM control).
1228 hwmon device attribute fan1_input:
1229 Fan tachometer reading, in RPM. May go stale on certain
1230 ThinkPads while the EC transitions the PWM to offline mode,
1231 which can take up to two minutes. May return rubbish on older
1234 hwmon driver attribute fan_watchdog:
1235 Fan safety watchdog timer interval, in seconds. Minimum is
1236 1 second, maximum is 120 seconds. 0 disables the watchdog.
1238 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1240 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1241 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1242 would be the safest choice, though).
1248 procfs: /proc/acpi/ibm/wan
1249 sysfs device attribute: wwan_enable
1251 This feature is marked EXPERIMENTAL because the implementation
1252 directly accesses hardware registers and may not work as expected. USE
1253 WITH CAUTION! To use this feature, you need to supply the
1254 experimental=1 parameter when loading the module.
1256 This feature shows the presence and current state of a W-WAN (Sierra
1257 Wireless EV-DO) device.
1259 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1260 Thinkpad models which come with this module installed.
1264 If the W-WAN card is installed, the following commands can be used:
1266 echo enable > /proc/acpi/ibm/wan
1267 echo disable > /proc/acpi/ibm/wan
1271 If the W-WAN card is installed, it can be enabled /
1272 disabled through the "wwan_enable" thinkpad-acpi device
1273 attribute, and its current status can also be queried.
1276 0: disables WWAN card / WWAN card is disabled
1277 1: enables WWAN card / WWAN card is enabled.
1279 Note: this interface will be probably be superseeded by the
1280 generic rfkill class, so it is NOT to be considered stable yet.
1282 Multiple Commands, Module Parameters
1283 ------------------------------------
1285 Multiple commands can be written to the proc files in one shot by
1286 separating them with commas, for example:
1288 echo enable,0xffff > /proc/acpi/ibm/hotkey
1289 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1291 Commands can also be specified when loading the thinkpad-acpi module,
1294 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1296 Enabling debugging output
1297 -------------------------
1299 The module takes a debug parameter which can be used to selectively
1300 enable various classes of debugging output, for example:
1302 modprobe ibm_acpi debug=0xffff
1304 will enable all debugging output classes. It takes a bitmask, so
1305 to enable more than one output class, just add their values.
1307 Debug bitmask Description
1308 0x0001 Initialization and probing
1311 There is also a kernel build option to enable more debugging
1312 information, which may be necessary to debug driver problems.
1314 The level of debugging information output by the driver can be changed
1315 at runtime through sysfs, using the driver attribute debug_level. The
1316 attribute takes the same bitmask as the debug module parameter above.
1318 Force loading of module
1319 -----------------------
1321 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1322 the module parameter force_load=1. Regardless of whether this works or
1323 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1326 Sysfs interface changelog:
1328 0x000100: Initial sysfs support, as a single platform driver and
1330 0x000200: Hot key support for 32 hot keys, and radio slider switch
1332 0x010000: Hot keys are now handled by default over the input
1333 layer, the radio switch generates input event EV_RADIO,
1334 and the driver enables hot key handling by default in
1337 0x020000: ABI fix: added a separate hwmon platform device and
1338 driver, which must be located by name (thinkpad)
1339 and the hwmon class for libsensors4 (lm-sensors 3)
1340 compatibility. Moved all hwmon attributes to this
1341 new platform device.
1343 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1344 support. If you must, use it to know you should not
1345 start an userspace NVRAM poller (allows to detect when
1346 NVRAM is compiled out by the user because it is
1347 unneeded/undesired in the first place).
1348 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1349 and proper hotkey_mask semanthics (version 8 of the
1350 NVRAM polling patch). Some development snapshots of
1351 0.18 had an earlier version that did strange things
projects / linux-2.6 / blob