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 Returns the state of the procfs ACPI event report mode
318 filter for hot keys. If it is set to 1 (the default),
319 all hot key presses are reported both through the input
320 layer and also as ACPI events through procfs (but not
321 through netlink). If it is set to 2, hot key presses
322 are reported only through the input layer.
324 This attribute is read-only in kernels 2.6.23 or later,
325 and read-write on earlier kernels.
327 May return -EPERM (write access locked out by module
328 parameter) or -EACCES (read-only).
331 Set to 1 if the system is waking up because the user
332 requested a bay ejection. Set to 2 if the system is
333 waking up because the user requested the system to
334 undock. Set to zero for normal wake-ups or wake-ups
335 due to unknown reasons.
337 This attribute has poll()/select() support.
339 wakeup_hotunplug_complete:
340 Set to 1 if the system was waken up because of an
341 undock or bay ejection request, and that request
342 was successfully completed. At this point, it might
343 be useful to send the system back to sleep, at the
344 user's choice. Refer to HKEY events 0x4003 and
347 This attribute has poll()/select() support.
351 A Hot key is mapped to a single input layer EV_KEY event, possibly
352 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
353 code. An EV_SYN event will always be generated to mark the end of the
356 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
357 used as a helper to remap keys, only. They are particularly useful when
358 remapping KEY_UNKNOWN keys.
360 The events are available in an input device, with the following id:
363 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
364 0x17aa (PCI_VENDOR_ID_LENOVO)
365 product: 0x5054 ("TP")
368 The version will have its LSB incremented if the keymap changes in a
369 backwards-compatible way. The MSB shall always be 0x41 for this input
370 device. If the MSB is not 0x41, do not use the device as described in
371 this section, as it is either something else (e.g. another input device
372 exported by a thinkpad driver, such as HDAPS) or its functionality has
373 been changed in a non-backwards compatible way.
375 Adding other event types for other functionalities shall be considered a
376 backwards-compatible change for this input device.
378 Thinkpad-acpi Hot Key event map (version 0x4101):
384 0x1002 0x01 FN+F2 IBM: battery (rare)
387 0x1003 0x02 FN+F3 Many IBM models always report
388 this hot key, even with hot keys
389 disabled or with Fn+F3 masked
394 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
395 semantics, i.e. sleep-to-RAM).
396 It is always generate some kind
397 of event, either the hot key
398 event or a ACPI sleep button
399 event. The firmware may
400 refuse to generate further FN+F4
401 key presses until a S3 or S4 ACPI
402 sleep cycle is performed or some
405 0x1005 0x04 FN+F5 Radio. Enables/disables
406 the internal Bluetooth hardware
407 and W-WAN card if left in control
408 of the firmware. Does not affect
410 Should be used to turn on/off all
411 radios (Bluetooth+W-WAN+WLAN),
416 0x1007 0x06 FN+F7 Video output cycle.
417 Do you feel lucky today?
419 0x1008 0x07 FN+F8 IBM: toggle screen expand
420 Lenovo: configure UltraNav
426 0x100C 0x0B FN+F12 Sleep to disk. You are always
427 supposed to handle it yourself,
428 either through the ACPI event,
429 or through a hotkey event.
430 The firmware may refuse to
431 generate further FN+F4 key
432 press events until a S3 or S4
433 ACPI sleep cycle is performed,
436 0x100D 0x0C FN+BACKSPACE -
437 0x100E 0x0D FN+INSERT -
438 0x100F 0x0E FN+DELETE -
440 0x1010 0x0F FN+HOME Brightness up. This key is
441 always handled by the firmware
442 in IBM ThinkPads, even when
443 unmasked. Just leave it alone.
444 For Lenovo ThinkPads with a new
445 BIOS, it has to be handled either
446 by the ACPI OSI, or by userspace.
447 0x1011 0x10 FN+END Brightness down. See brightness
450 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
451 always handled by the firmware,
454 0x1013 0x12 FN+PGDOWN -
456 0x1014 0x13 FN+SPACE Zoom key
458 0x1015 0x14 VOLUME UP Internal mixer volume up. This
459 key is always handled by the
460 firmware, even when unmasked.
461 NOTE: Lenovo seems to be changing
463 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
464 key is always handled by the
465 firmware, even when unmasked.
466 NOTE: Lenovo seems to be changing
468 0x1017 0x16 MUTE Mute internal mixer. This
469 key is always handled by the
470 firmware, even when unmasked.
472 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
478 The ThinkPad firmware does not allow one to differentiate when most hot
479 keys are pressed or released (either that, or we don't know how to, yet).
480 For these keys, the driver generates a set of events for a key press and
481 immediately issues the same set of events for a key release. It is
482 unknown by the driver if the ThinkPad firmware triggered these events on
483 hot key press or release, but the firmware will do it for either one, not
486 If a key is mapped to KEY_RESERVED, it generates no input events at all.
487 If a key is mapped to KEY_UNKNOWN, it generates an input event that
488 includes an scan code. If a key is mapped to anything else, it will
489 generate input device EV_KEY events.
491 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
494 SW_RADIO T60 and later hardare rfkill rocker switch
495 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
497 Non hot-key ACPI HKEY event map:
500 0x5009 Tablet swivel: switched to tablet mode
501 0x500A Tablet swivel: switched to normal mode
502 0x7000 Radio Switch may have changed state
504 The above events are not propagated by the driver, except for legacy
505 compatibility purposes when hotkey_report_mode is set to 1.
507 0x2304 System is waking up from suspend to undock
508 0x2305 System is waking up from suspend to eject bay
509 0x2404 System is waking up from hibernation to undock
510 0x2405 System is waking up from hibernation to eject bay
512 The above events are never propagated by the driver.
514 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
515 0x4003 Undocked (see 0x2x04), can sleep again
516 0x500B Tablet pen inserted into its storage bay
517 0x500C Tablet pen removed from its storage bay
518 0x5010 Brightness level changed (newer Lenovo BIOSes)
520 The above events are propagated by the driver.
524 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
525 supported the input layer, and sent events over the procfs ACPI event
528 To avoid sending duplicate events over the input layer and the ACPI
529 event interface, thinkpad-acpi 0.16 implements a module parameter
530 (hotkey_report_mode), and also a sysfs device attribute with the same
533 Make no mistake here: userspace is expected to switch to using the input
534 layer interface of thinkpad-acpi, together with the ACPI netlink event
535 interface in kernels 2.6.23 and later, or with the ACPI procfs event
536 interface in kernels 2.6.22 and earlier.
538 If no hotkey_report_mode module parameter is specified (or it is set to
539 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
540 and earlier, also allows one to change the hotkey_report_mode through
541 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
542 interface is available, hotkey_report_mode cannot be changed through
543 sysfs (it is read-only).
545 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
546 be changed later through sysfs (any writes will return -EPERM to signal
547 that hotkey_report_mode was locked. On 2.6.23 and later, where
548 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
550 hotkey_report_mode set to 1 makes the driver export through the procfs
551 ACPI event interface all hot key presses (which are *also* sent to the
552 input layer). This is a legacy compatibility behaviour, and it is also
553 the default mode of operation for the driver.
555 hotkey_report_mode set to 2 makes the driver filter out the hot key
556 presses from the procfs ACPI event interface, so these events will only
557 be sent through the input layer. Userspace that has been updated to use
558 the thinkpad-acpi input layer interface should set hotkey_report_mode to
561 Hot key press events are never sent to the ACPI netlink event interface.
562 Really up-to-date userspace under kernel 2.6.23 and later is to use the
563 netlink interface and the input layer interface, and don't bother at all
564 with hotkey_report_mode.
570 procfs: /proc/acpi/ibm/bluetooth
571 sysfs device attribute: bluetooth_enable
573 This feature shows the presence and current state of a ThinkPad
574 Bluetooth device in the internal ThinkPad CDC slot.
578 If Bluetooth is installed, the following commands can be used:
580 echo enable > /proc/acpi/ibm/bluetooth
581 echo disable > /proc/acpi/ibm/bluetooth
585 If the Bluetooth CDC card is installed, it can be enabled /
586 disabled through the "bluetooth_enable" thinkpad-acpi device
587 attribute, and its current status can also be queried.
590 0: disables Bluetooth / Bluetooth is disabled
591 1: enables Bluetooth / Bluetooth is enabled.
593 Note: this interface will be probably be superseded by the
594 generic rfkill class, so it is NOT to be considered stable yet.
596 Video output control -- /proc/acpi/ibm/video
597 --------------------------------------------
599 This feature allows control over the devices used for video output -
600 LCD, CRT or DVI (if available). The following commands are available:
602 echo lcd_enable > /proc/acpi/ibm/video
603 echo lcd_disable > /proc/acpi/ibm/video
604 echo crt_enable > /proc/acpi/ibm/video
605 echo crt_disable > /proc/acpi/ibm/video
606 echo dvi_enable > /proc/acpi/ibm/video
607 echo dvi_disable > /proc/acpi/ibm/video
608 echo auto_enable > /proc/acpi/ibm/video
609 echo auto_disable > /proc/acpi/ibm/video
610 echo expand_toggle > /proc/acpi/ibm/video
611 echo video_switch > /proc/acpi/ibm/video
613 Each video output device can be enabled or disabled individually.
614 Reading /proc/acpi/ibm/video shows the status of each device.
616 Automatic video switching can be enabled or disabled. When automatic
617 video switching is enabled, certain events (e.g. opening the lid,
618 docking or undocking) cause the video output device to change
619 automatically. While this can be useful, it also causes flickering
620 and, on the X40, video corruption. By disabling automatic switching,
621 the flickering or video corruption can be avoided.
623 The video_switch command cycles through the available video outputs
624 (it simulates the behavior of Fn-F7).
626 Video expansion can be toggled through this feature. This controls
627 whether the display is expanded to fill the entire LCD screen when a
628 mode with less than full resolution is used. Note that the current
629 video expansion status cannot be determined through this feature.
631 Note that on many models (particularly those using Radeon graphics
632 chips) the X driver configures the video card in a way which prevents
633 Fn-F7 from working. This also disables the video output switching
634 features of this driver, as it uses the same ACPI methods as
635 Fn-F7. Video switching on the console should still work.
637 UPDATE: There's now a patch for the X.org Radeon driver which
638 addresses this issue. Some people are reporting success with the patch
639 while others are still having problems. For more information:
641 https://bugs.freedesktop.org/show_bug.cgi?id=2000
643 ThinkLight control -- /proc/acpi/ibm/light
644 ------------------------------------------
646 The current status of the ThinkLight can be found in this file. A few
647 models which do not make the status available will show it as
648 "unknown". The available commands are:
650 echo on > /proc/acpi/ibm/light
651 echo off > /proc/acpi/ibm/light
653 Docking / undocking -- /proc/acpi/ibm/dock
654 ------------------------------------------
656 Docking and undocking (e.g. with the X4 UltraBase) requires some
657 actions to be taken by the operating system to safely make or break
658 the electrical connections with the dock.
660 The docking feature of this driver generates the following ACPI events:
662 ibm/dock GDCK 00000003 00000001 -- eject request
663 ibm/dock GDCK 00000003 00000002 -- undocked
664 ibm/dock GDCK 00000000 00000003 -- docked
666 NOTE: These events will only be generated if the laptop was docked
667 when originally booted. This is due to the current lack of support for
668 hot plugging of devices in the Linux ACPI framework. If the laptop was
669 booted while not in the dock, the following message is shown in the
672 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
674 In this case, no dock-related events are generated but the dock and
675 undock commands described below still work. They can be executed
676 manually or triggered by Fn key combinations (see the example acpid
677 configuration files included in the driver tarball package available
680 When the eject request button on the dock is pressed, the first event
681 above is generated. The handler for this event should issue the
684 echo undock > /proc/acpi/ibm/dock
686 After the LED on the dock goes off, it is safe to eject the laptop.
687 Note: if you pressed this key by mistake, go ahead and eject the
688 laptop, then dock it back in. Otherwise, the dock may not function as
691 When the laptop is docked, the third event above is generated. The
692 handler for this event should issue the following command to fully
695 echo dock > /proc/acpi/ibm/dock
697 The contents of the /proc/acpi/ibm/dock file shows the current status
698 of the dock, as provided by the ACPI framework.
700 The docking support in this driver does not take care of enabling or
701 disabling any other devices you may have attached to the dock. For
702 example, a CD drive plugged into the UltraBase needs to be disabled or
703 enabled separately. See the provided example acpid configuration files
704 for how this can be accomplished.
706 There is no support yet for PCI devices that may be attached to a
707 docking station, e.g. in the ThinkPad Dock II. The driver currently
708 does not recognize, enable or disable such devices. This means that
709 the only docking stations currently supported are the X-series
710 UltraBase docks and "dumb" port replicators like the Mini Dock (the
711 latter don't need any ACPI support, actually).
713 UltraBay eject -- /proc/acpi/ibm/bay
714 ------------------------------------
716 Inserting or ejecting an UltraBay device requires some actions to be
717 taken by the operating system to safely make or break the electrical
718 connections with the device.
720 This feature generates the following ACPI events:
722 ibm/bay MSTR 00000003 00000000 -- eject request
723 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
725 NOTE: These events will only be generated if the UltraBay was present
726 when the laptop was originally booted (on the X series, the UltraBay
727 is in the dock, so it may not be present if the laptop was undocked).
728 This is due to the current lack of support for hot plugging of devices
729 in the Linux ACPI framework. If the laptop was booted without the
730 UltraBay, the following message is shown in the logs:
732 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
734 In this case, no bay-related events are generated but the eject
735 command described below still works. It can be executed manually or
736 triggered by a hot key combination.
738 Sliding the eject lever generates the first event shown above. The
739 handler for this event should take whatever actions are necessary to
740 shut down the device in the UltraBay (e.g. call idectl), then issue
741 the following command:
743 echo eject > /proc/acpi/ibm/bay
745 After the LED on the UltraBay goes off, it is safe to pull out the
748 When the eject lever is inserted, the second event above is
749 generated. The handler for this event should take whatever actions are
750 necessary to enable the UltraBay device (e.g. call idectl).
752 The contents of the /proc/acpi/ibm/bay file shows the current status
753 of the UltraBay, as provided by the ACPI framework.
755 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
756 this feature, you need to supply the experimental=1 parameter when
759 These models do not have a button near the UltraBay device to request
760 a hot eject but rather require the laptop to be put to sleep
761 (suspend-to-ram) before the bay device is ejected or inserted).
762 The sequence of steps to eject the device is as follows:
764 echo eject > /proc/acpi/ibm/bay
765 put the ThinkPad to sleep
768 cat /proc/acpi/ibm/bay should show that the drive was removed
770 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
771 supported. Use "eject2" instead of "eject" for the second bay.
773 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
774 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
779 procfs: /proc/acpi/ibm/cmos
780 sysfs device attribute: cmos_command
782 This feature is mostly used internally by the ACPI firmware to keep the legacy
783 CMOS NVRAM bits in sync with the current machine state, and to record this
784 state so that the ThinkPad will retain such settings across reboots.
786 Some of these commands actually perform actions in some ThinkPad models, but
787 this is expected to disappear more and more in newer models. As an example, in
788 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
789 real, but commands 0 to 2 don't control the mixer anymore (they have been
790 phased out) and just update the NVRAM.
792 The range of valid cmos command numbers is 0 to 21, but not all have an
793 effect and the behavior varies from model to model. Here is the behavior
794 on the X40 (tpb is the ThinkPad Buttons utility):
796 0 - Related to "Volume down" key press
797 1 - Related to "Volume up" key press
798 2 - Related to "Mute on" key press
799 3 - Related to "Access IBM" key press
800 4 - Related to "LCD brightness up" key press
801 5 - Related to "LCD brightness down" key press
802 11 - Related to "toggle screen expansion" key press/function
803 12 - Related to "ThinkLight on"
804 13 - Related to "ThinkLight off"
805 14 - Related to "ThinkLight" key press (toggle ThinkLight)
807 The cmos command interface is prone to firmware split-brain problems, as
808 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
809 exported just as a debug tool.
811 LED control -- /proc/acpi/ibm/led
812 ---------------------------------
814 Some of the LED indicators can be controlled through this feature. The
815 available commands are:
817 echo '<led number> on' >/proc/acpi/ibm/led
818 echo '<led number> off' >/proc/acpi/ibm/led
819 echo '<led number> blink' >/proc/acpi/ibm/led
821 The <led number> range is 0 to 7. The set of LEDs that can be
822 controlled varies from model to model. Here is the mapping on the X40:
831 All of the above can be turned on and off and can be made to blink.
833 ACPI sounds -- /proc/acpi/ibm/beep
834 ----------------------------------
836 The BEEP method is used internally by the ACPI firmware to provide
837 audible alerts in various situations. This feature allows the same
838 sounds to be triggered manually.
840 The commands are non-negative integer numbers:
842 echo <number> >/proc/acpi/ibm/beep
844 The valid <number> range is 0 to 17. Not all numbers trigger sounds
845 and the sounds vary from model to model. Here is the behavior on the
848 0 - stop a sound in progress (but use 17 to stop 16)
849 2 - two beeps, pause, third beep ("low battery")
851 4 - high, followed by low-pitched beep ("unable")
853 6 - very high, followed by high-pitched beep ("AC/DC")
854 7 - high-pitched beep
855 9 - three short beeps
857 12 - low-pitched beep
858 15 - three high-pitched beeps repeating constantly, stop with 0
859 16 - one medium-pitched beep repeating constantly, stop with 17
865 procfs: /proc/acpi/ibm/thermal
866 sysfs device attributes: (hwmon "thinkpad") temp*_input
868 Most ThinkPads include six or more separate temperature sensors but only
869 expose the CPU temperature through the standard ACPI methods. This
870 feature shows readings from up to eight different sensors on older
871 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
873 For example, on the X40, a typical output may be:
874 temperatures: 42 42 45 41 36 -128 33 -128
876 On the T43/p, a typical output may be:
877 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
879 The mapping of thermal sensors to physical locations varies depending on
880 system-board model (and thus, on ThinkPad model).
882 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
883 tries to track down these locations for various models.
885 Most (newer?) models seem to follow this pattern:
888 2: (depends on model)
889 3: (depends on model)
891 5: Main battery: main sensor
892 6: Bay battery: main sensor
893 7: Main battery: secondary sensor
894 8: Bay battery: secondary sensor
895 9-15: (depends on model)
897 For the R51 (source: Thomas Gruber):
901 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
902 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
903 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
905 9: MCH (northbridge) to DRAM Bus
906 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
908 11: Power regulator, underside of system board, below F2 key
910 The A31 has a very atypical layout for the thermal sensors
911 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
913 2: Main Battery: main sensor
915 4: Bay Battery: main sensor
918 7: Main Battery: secondary sensor
919 8: Bay Battery: secondary sensor
923 Readings from sensors that are not available return -128.
924 No commands can be written to this file.
927 Sensors that are not available return the ENXIO error. This
928 status may change at runtime, as there are hotplug thermal
929 sensors, like those inside the batteries and docks.
931 thinkpad-acpi thermal sensors are reported through the hwmon
932 subsystem, and follow all of the hwmon guidelines at
936 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
937 ------------------------------------------------------------------------
939 This feature is marked EXPERIMENTAL because the implementation
940 directly accesses hardware registers and may not work as expected. USE
941 WITH CAUTION! To use this feature, you need to supply the
942 experimental=1 parameter when loading the module.
944 This feature dumps the values of 256 embedded controller
945 registers. Values which have changed since the last time the registers
946 were dumped are marked with a star:
948 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
949 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
950 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
951 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
952 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
953 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
954 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
955 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
956 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
957 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
958 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
959 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
960 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
961 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
962 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
963 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
964 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
965 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
967 This feature can be used to determine the register holding the fan
968 speed on some models. To do that, do the following:
970 - make sure the battery is fully charged
971 - make sure the fan is running
972 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
974 The first step makes sure various charging-related values don't
975 vary. The second ensures that the fan-related values do vary, since
976 the fan speed fluctuates a bit. The third will (hopefully) mark the
977 fan register with a star:
979 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
980 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
981 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
982 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
983 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
984 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
985 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
986 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
987 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
988 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
989 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
990 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
991 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
992 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
993 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
994 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
995 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
996 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
998 Another set of values that varies often is the temperature
999 readings. Since temperatures don't change vary fast, you can take
1000 several quick dumps to eliminate them.
1002 You can use a similar method to figure out the meaning of other
1003 embedded controller registers - e.g. make sure nothing else changes
1004 except the charging or discharging battery to determine which
1005 registers contain the current battery capacity, etc. If you experiment
1006 with this, do send me your results (including some complete dumps with
1007 a description of the conditions when they were taken.)
1009 LCD brightness control
1010 ----------------------
1012 procfs: /proc/acpi/ibm/brightness
1013 sysfs backlight device "thinkpad_screen"
1015 This feature allows software control of the LCD brightness on ThinkPad
1016 models which don't have a hardware brightness slider.
1018 It has some limitations: the LCD backlight cannot be actually turned on or
1019 off by this interface, and in many ThinkPad models, the "dim while on
1020 battery" functionality will be enabled by the BIOS when this interface is
1021 used, and cannot be controlled.
1023 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1024 has eight brightness levels, ranging from 0 to 7. Some of the levels
1025 may not be distinct. Later Lenovo models that implement the ACPI
1026 display backlight brightness control methods have 16 levels, ranging
1029 There are two interfaces to the firmware for direct brightness control,
1030 EC and CMOS. To select which one should be used, use the
1031 brightness_mode module parameter: brightness_mode=1 selects EC mode,
1032 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
1033 and CMOS. The driver tries to auto-detect which interface to use.
1035 When display backlight brightness controls are available through the
1036 standard ACPI interface, it is best to use it instead of this direct
1037 ThinkPad-specific interface. The driver will disable its native
1038 backlight brightness control interface if it detects that the standard
1039 ACPI interface is available in the ThinkPad.
1041 The brightness_enable module parameter can be used to control whether
1042 the LCD brightness control feature will be enabled when available.
1043 brightness_enable=0 forces it to be disabled. brightness_enable=1
1044 forces it to be enabled when available, even if the standard ACPI
1045 interface is also available.
1049 The available commands are:
1051 echo up >/proc/acpi/ibm/brightness
1052 echo down >/proc/acpi/ibm/brightness
1053 echo 'level <level>' >/proc/acpi/ibm/brightness
1057 The interface is implemented through the backlight sysfs class, which is
1058 poorly documented at this time.
1060 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1061 it there will be the following attributes:
1064 Reads the maximum brightness the hardware can be set to.
1065 The minimum is always zero.
1068 Reads what brightness the screen is set to at this instant.
1071 Writes request the driver to change brightness to the
1072 given value. Reads will tell you what brightness the
1073 driver is trying to set the display to when "power" is set
1074 to zero and the display has not been dimmed by a kernel
1075 power management event.
1078 power management mode, where 0 is "display on", and 1 to 3
1079 will dim the display backlight to brightness level 0
1080 because thinkpad-acpi cannot really turn the backlight
1081 off. Kernel power management events can temporarily
1082 increase the current power management level, i.e. they can
1086 Volume control -- /proc/acpi/ibm/volume
1087 ---------------------------------------
1089 This feature allows volume control on ThinkPad models which don't have
1090 a hardware volume knob. The available commands are:
1092 echo up >/proc/acpi/ibm/volume
1093 echo down >/proc/acpi/ibm/volume
1094 echo mute >/proc/acpi/ibm/volume
1095 echo 'level <level>' >/proc/acpi/ibm/volume
1097 The <level> number range is 0 to 15 although not all of them may be
1098 distinct. The unmute the volume after the mute command, use either the
1099 up or down command (the level command will not unmute the volume).
1100 The current volume level and mute state is shown in the file.
1102 Fan control and monitoring: fan speed, fan enable/disable
1103 ---------------------------------------------------------
1105 procfs: /proc/acpi/ibm/fan
1106 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1108 sysfs hwmon driver attributes: fan_watchdog
1110 NOTE NOTE NOTE: fan control operations are disabled by default for
1111 safety reasons. To enable them, the module parameter "fan_control=1"
1112 must be given to thinkpad-acpi.
1114 This feature attempts to show the current fan speed, control mode and
1115 other fan data that might be available. The speed is read directly
1116 from the hardware registers of the embedded controller. This is known
1117 to work on later R, T, X and Z series ThinkPads but may show a bogus
1118 value on other models.
1122 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1123 stops the fan. The higher the level, the higher the fan speed, although
1124 adjacent levels often map to the same fan speed. 7 is the highest
1125 level, where the fan reaches the maximum recommended speed.
1127 Level "auto" means the EC changes the fan level according to some
1128 internal algorithm, usually based on readings from the thermal sensors.
1130 There is also a "full-speed" level, also known as "disengaged" level.
1131 In this level, the EC disables the speed-locked closed-loop fan control,
1132 and drives the fan as fast as it can go, which might exceed hardware
1133 limits, so use this level with caution.
1135 The fan usually ramps up or down slowly from one speed to another, and
1136 it is normal for the EC to take several seconds to react to fan
1137 commands. The full-speed level may take up to two minutes to ramp up to
1138 maximum speed, and in some ThinkPads, the tachometer readings go stale
1139 while the EC is transitioning to the full-speed level.
1141 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1142 monitoring all of the temperature sensor readings and you are ready to
1143 enable it if necessary to avoid overheating.
1145 An enabled fan in level "auto" may stop spinning if the EC decides the
1146 ThinkPad is cool enough and doesn't need the extra airflow. This is
1147 normal, and the EC will spin the fan up if the various thermal readings
1150 On the X40, this seems to depend on the CPU and HDD temperatures.
1151 Specifically, the fan is turned on when either the CPU temperature
1152 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1153 fan is turned off when the CPU temperature drops to 49 degrees and the
1154 HDD temperature drops to 41 degrees. These thresholds cannot
1155 currently be controlled.
1157 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1158 certain conditions are met. It will override any fan programming done
1159 through thinkpad-acpi.
1161 The thinkpad-acpi kernel driver can be programmed to revert the fan
1162 level to a safe setting if userspace does not issue one of the procfs
1163 fan commands: "enable", "disable", "level" or "watchdog", or if there
1164 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1165 set to 1, manual mode) within a configurable amount of time of up to
1166 120 seconds. This functionality is called fan safety watchdog.
1168 Note that the watchdog timer stops after it enables the fan. It will be
1169 rearmed again automatically (using the same interval) when one of the
1170 above mentioned fan commands is received. The fan watchdog is,
1171 therefore, not suitable to protect against fan mode changes made through
1172 means other than the "enable", "disable", and "level" procfs fan
1173 commands, or the hwmon fan control sysfs interface.
1177 The fan may be enabled or disabled with the following commands:
1179 echo enable >/proc/acpi/ibm/fan
1180 echo disable >/proc/acpi/ibm/fan
1182 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1183 will try to place it in a safe level if it is too slow or disabled.
1185 The fan level can be controlled with the command:
1187 echo 'level <level>' > /proc/acpi/ibm/fan
1189 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1190 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1191 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1192 "full-speed", and reports it as "disengaged" for backwards
1195 On the X31 and X40 (and ONLY on those models), the fan speed can be
1196 controlled to a certain degree. Once the fan is running, it can be
1197 forced to run faster or slower with the following command:
1199 echo 'speed <speed>' > /proc/acpi/ibm/fan
1201 The sustainable range of fan speeds on the X40 appears to be from about
1202 3700 to about 7350. Values outside this range either do not have any
1203 effect or the fan speed eventually settles somewhere in that range. The
1204 fan cannot be stopped or started with this command. This functionality
1205 is incomplete, and not available through the sysfs interface.
1207 To program the safety watchdog, use the "watchdog" command.
1209 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1211 If you want to disable the watchdog, use 0 as the interval.
1215 The sysfs interface follows the hwmon subsystem guidelines for the most
1216 part, and the exception is the fan safety watchdog.
1218 Writes to any of the sysfs attributes may return the EINVAL error if
1219 that operation is not supported in a given ThinkPad or if the parameter
1220 is out-of-bounds, and EPERM if it is forbidden. They may also return
1221 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1224 Features not yet implemented by the driver return ENOSYS.
1226 hwmon device attribute pwm1_enable:
1227 0: PWM offline (fan is set to full-speed mode)
1228 1: Manual PWM control (use pwm1 to set fan level)
1229 2: Hardware PWM control (EC "auto" mode)
1230 3: reserved (Software PWM control, not implemented yet)
1232 Modes 0 and 2 are not supported by all ThinkPads, and the
1233 driver is not always able to detect this. If it does know a
1234 mode is unsupported, it will return -EINVAL.
1236 hwmon device attribute pwm1:
1237 Fan level, scaled from the firmware values of 0-7 to the hwmon
1238 scale of 0-255. 0 means fan stopped, 255 means highest normal
1241 This attribute only commands the fan if pmw1_enable is set to 1
1242 (manual PWM control).
1244 hwmon device attribute fan1_input:
1245 Fan tachometer reading, in RPM. May go stale on certain
1246 ThinkPads while the EC transitions the PWM to offline mode,
1247 which can take up to two minutes. May return rubbish on older
1250 hwmon driver attribute fan_watchdog:
1251 Fan safety watchdog timer interval, in seconds. Minimum is
1252 1 second, maximum is 120 seconds. 0 disables the watchdog.
1254 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1256 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1257 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1258 would be the safest choice, though).
1264 procfs: /proc/acpi/ibm/wan
1265 sysfs device attribute: wwan_enable
1267 This feature is marked EXPERIMENTAL because the implementation
1268 directly accesses hardware registers and may not work as expected. USE
1269 WITH CAUTION! To use this feature, you need to supply the
1270 experimental=1 parameter when loading the module.
1272 This feature shows the presence and current state of a W-WAN (Sierra
1273 Wireless EV-DO) device.
1275 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1276 ThinkPad models which come with this module installed.
1280 If the W-WAN card is installed, the following commands can be used:
1282 echo enable > /proc/acpi/ibm/wan
1283 echo disable > /proc/acpi/ibm/wan
1287 If the W-WAN card is installed, it can be enabled /
1288 disabled through the "wwan_enable" thinkpad-acpi device
1289 attribute, and its current status can also be queried.
1292 0: disables WWAN card / WWAN card is disabled
1293 1: enables WWAN card / WWAN card is enabled.
1295 Note: this interface will be probably be superseded by the
1296 generic rfkill class, so it is NOT to be considered stable yet.
1298 Multiple Commands, Module Parameters
1299 ------------------------------------
1301 Multiple commands can be written to the proc files in one shot by
1302 separating them with commas, for example:
1304 echo enable,0xffff > /proc/acpi/ibm/hotkey
1305 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1307 Commands can also be specified when loading the thinkpad-acpi module,
1310 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1312 Enabling debugging output
1313 -------------------------
1315 The module takes a debug parameter which can be used to selectively
1316 enable various classes of debugging output, for example:
1318 modprobe thinkpad_acpi debug=0xffff
1320 will enable all debugging output classes. It takes a bitmask, so
1321 to enable more than one output class, just add their values.
1323 Debug bitmask Description
1324 0x0001 Initialization and probing
1327 There is also a kernel build option to enable more debugging
1328 information, which may be necessary to debug driver problems.
1330 The level of debugging information output by the driver can be changed
1331 at runtime through sysfs, using the driver attribute debug_level. The
1332 attribute takes the same bitmask as the debug module parameter above.
1334 Force loading of module
1335 -----------------------
1337 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1338 the module parameter force_load=1. Regardless of whether this works or
1339 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1342 Sysfs interface changelog:
1344 0x000100: Initial sysfs support, as a single platform driver and
1346 0x000200: Hot key support for 32 hot keys, and radio slider switch
1348 0x010000: Hot keys are now handled by default over the input
1349 layer, the radio switch generates input event EV_RADIO,
1350 and the driver enables hot key handling by default in
1353 0x020000: ABI fix: added a separate hwmon platform device and
1354 driver, which must be located by name (thinkpad)
1355 and the hwmon class for libsensors4 (lm-sensors 3)
1356 compatibility. Moved all hwmon attributes to this
1357 new platform device.
1359 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1360 support. If you must, use it to know you should not
1361 start an userspace NVRAM poller (allows to detect when
1362 NVRAM is compiled out by the user because it is
1363 unneeded/undesired in the first place).
1364 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1365 and proper hotkey_mask semantics (version 8 of the
1366 NVRAM polling patch). Some development snapshots of
1367 0.18 had an earlier version that did strange things
1370 0x020200: Add poll()/select() support to the following attributes:
1371 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
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