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 2.6.20 this is /sys/bus/platform/drivers/thinkpad_acpi/.
110 Sysfs device attributes are on the driver's sysfs attribute space,
111 for 2.6.20 this is /sys/devices/platform/thinkpad_acpi/.
116 procfs: /proc/acpi/ibm/driver
117 sysfs driver attribute: version
119 The driver name and version. No commands can be written to this file.
121 Sysfs interface version
122 -----------------------
124 sysfs driver attribute: interface_version
126 Version of the thinkpad-acpi sysfs interface, as an unsigned long
127 (output in hex format: 0xAAAABBCC), where:
128 AAAA - major revision
132 The sysfs interface version changelog for the driver can be found at the
133 end of this document. Changes to the sysfs interface done by the kernel
134 subsystems are not documented here, nor are they tracked by this
137 Changes to the thinkpad-acpi sysfs interface are only considered
138 non-experimental when they are submitted to Linux mainline, at which
139 point the changes in this interface are documented and interface_version
140 may be updated. If you are using any thinkpad-acpi features not yet
141 sent to mainline for merging, you do so on your own risk: these features
142 may disappear, or be implemented in a different and incompatible way by
143 the time they are merged in Linux mainline.
145 Changes that are backwards-compatible by nature (e.g. the addition of
146 attributes that do not change the way the other attributes work) do not
147 always warrant an update of interface_version. Therefore, one must
148 expect that an attribute might not be there, and deal with it properly
149 (an attribute not being there *is* a valid way to make it clear that a
150 feature is not available in sysfs).
155 procfs: /proc/acpi/ibm/hotkey
156 sysfs device attribute: hotkey_*
158 In a ThinkPad, the ACPI HKEY handler is responsible for comunicating
159 some important events and also keyboard hot key presses to the operating
160 system. Enabling the hotkey functionality of thinkpad-acpi signals the
161 firmware that such a driver is present, and modifies how the ThinkPad
162 firmware will behave in many situations.
164 The driver enables the hot key feature automatically when loaded. The
165 feature can later be disabled and enabled back at runtime. The driver
166 will also restore the hot key feature to its previous state and mask
169 When the hotkey feature is enabled and the hot key mask is set (see
170 below), the driver will report HKEY events in the following format:
172 ibm/hotkey HKEY 00000080 0000xxxx
174 Some of these events refer to hot key presses, but not all.
176 The driver will generate events over the input layer for hot keys and
177 radio switches, and over the ACPI netlink layer for other events. The
178 input layer support accepts the standard IOCTLs to remap the keycodes
179 assigned to each hot key.
181 The hot key bit mask allows some control over which hot keys generate
182 events. If a key is "masked" (bit set to 0 in the mask), the firmware
183 will handle it. If it is "unmasked", it signals the firmware that
184 thinkpad-acpi would prefer to handle it, if the firmware would be so
185 kind to allow it (and it often doesn't!).
187 Not all bits in the mask can be modified. Not all bits that can be
188 modified do anything. Not all hot keys can be individually controlled
189 by the mask. Some models do not support the mask at all, and in those
190 models, hot keys cannot be controlled individually. The behaviour of
191 the mask is, therefore, higly dependent on the ThinkPad model.
193 Note that unmasking some keys prevents their default behavior. For
194 example, if Fn+F5 is unmasked, that key will no longer enable/disable
197 Note also that not all Fn key combinations are supported through ACPI.
198 For example, on the X40, the brightness, volume and "Access IBM" buttons
199 do not generate ACPI events even with this driver. They *can* be used
200 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
204 The following commands can be written to the /proc/acpi/ibm/hotkey file:
206 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
207 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
208 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
209 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
210 ... any other 8-hex-digit mask ...
211 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
216 Returns the status of the hot keys feature when
217 thinkpad-acpi was loaded. Upon module unload, the hot
218 key feature status will be restored to this value.
220 0: hot keys were disabled
221 1: hot keys were enabled (unusual)
224 Returns the hot keys mask when thinkpad-acpi was loaded.
225 Upon module unload, the hot keys mask will be restored
229 Enables/disables the hot keys feature, and reports
230 current status of the hot keys feature.
232 0: disables the hot keys feature / feature disabled
233 1: enables the hot keys feature / feature enabled
236 bit mask to enable driver-handling and ACPI event
237 generation for each hot key (see above). Returns the
238 current status of the hot keys mask, and allows one to
242 bit mask that should enable event reporting for all
243 supported hot keys, when echoed to hotkey_mask above.
244 Unless you know which events need to be handled
245 passively (because the firmware *will* handle them
246 anyway), do *not* use hotkey_all_mask. Use
247 hotkey_recommended_mask, instead. You have been warned.
249 hotkey_recommended_mask:
250 bit mask that should enable event reporting for all
251 supported hot keys, except those which are always
252 handled by the firmware anyway. Echo it to
253 hotkey_mask above, to use.
256 if the ThinkPad has a hardware radio switch, this
257 attribute will read 0 if the switch is in the "radios
258 disabled" postition, and 1 if the switch is in the
259 "radios enabled" position.
262 Returns the state of the procfs ACPI event report mode
263 filter for hot keys. If it is set to 1 (the default),
264 all hot key presses are reported both through the input
265 layer and also as ACPI events through procfs (but not
266 through netlink). If it is set to 2, hot key presses
267 are reported only through the input layer.
269 This attribute is read-only in kernels 2.6.23 or later,
270 and read-write on earlier kernels.
272 May return -EPERM (write access locked out by module
273 parameter) or -EACCES (read-only).
277 A Hot key is mapped to a single input layer EV_KEY event, possibly
278 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
279 code. An EV_SYN event will always be generated to mark the end of the
282 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
283 used as a helper to remap keys, only. They are particularly useful when
284 remapping KEY_UNKNOWN keys.
286 The events are available in an input device, with the following id:
289 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
290 0x17aa (PCI_VENDOR_ID_LENOVO)
291 product: 0x5054 ("TP")
294 The version will have its LSB incremented if the keymap changes in a
295 backwards-compatible way. The MSB shall always be 0x41 for this input
296 device. If the MSB is not 0x41, do not use the device as described in
297 this section, as it is either something else (e.g. another input device
298 exported by a thinkpad driver, such as HDAPS) or its functionality has
299 been changed in a non-backwards compatible way.
301 Adding other event types for other functionalities shall be considered a
302 backwards-compatible change for this input device.
304 Thinkpad-acpi Hot Key event map (version 0x4101):
310 0x1002 0x01 FN+F2 IBM: battery (rare)
313 0x1003 0x02 FN+F3 Many IBM models always report
314 this hot key, even with hot keys
315 disabled or with Fn+F3 masked
320 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
321 semanthics, i.e. sleep-to-RAM).
322 It is always generate some kind
323 of event, either the hot key
324 event or a ACPI sleep button
325 event. The firmware may
326 refuse to generate further FN+F4
327 key presses until a S3 or S4 ACPI
328 sleep cycle is performed or some
331 0x1005 0x04 FN+F5 Radio. Enables/disables
332 the internal BlueTooth hardware
333 and W-WAN card if left in control
334 of the firmware. Does not affect
336 Should be used to turn on/off all
337 radios (bluetooth+W-WAN+WLAN),
342 0x1007 0x06 FN+F7 Video output cycle.
343 Do you feel lucky today?
345 0x1008 0x07 FN+F8 IBM: toggle screen expand
346 Lenovo: configure ultranav
352 0x100C 0x0B FN+F12 Sleep to disk. You are always
353 supposed to handle it yourself,
354 either through the ACPI event,
355 or through a hotkey event.
356 The firmware may refuse to
357 generate further FN+F4 key
358 press events until a S3 or S4
359 ACPI sleep cycle is performed,
362 0x100D 0x0C FN+BACKSPACE -
363 0x100E 0x0D FN+INSERT -
364 0x100F 0x0E FN+DELETE -
366 0x1010 0x0F FN+HOME Brightness up. This key is
367 always handled by the firmware
368 in IBM ThinkPads, even when
369 unmasked. Just leave it alone.
370 For Lenovo ThinkPads with a new
371 BIOS, it has to be handled either
372 by the ACPI OSI, or by userspace.
373 0x1011 0x10 FN+END Brightness down. See brightness
376 0x1012 0x11 FN+PGUP Thinklight toggle. This key is
377 always handled by the firmware,
380 0x1013 0x12 FN+PGDOWN -
382 0x1014 0x13 FN+SPACE Zoom key
384 0x1015 0x14 VOLUME UP Internal mixer volume up. This
385 key is always handled by the
386 firmware, even when unmasked.
387 NOTE: Lenovo seems to be changing
389 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
390 key is always handled by the
391 firmware, even when unmasked.
392 NOTE: Lenovo seems to be changing
394 0x1017 0x16 MUTE Mute internal mixer. This
395 key is always handled by the
396 firmware, even when unmasked.
398 0x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
404 The ThinkPad firmware does not allow one to differentiate when most hot
405 keys are pressed or released (either that, or we don't know how to, yet).
406 For these keys, the driver generates a set of events for a key press and
407 immediately issues the same set of events for a key release. It is
408 unknown by the driver if the ThinkPad firmware triggered these events on
409 hot key press or release, but the firmware will do it for either one, not
412 If a key is mapped to KEY_RESERVED, it generates no input events at all.
413 If a key is mapped to KEY_UNKNOWN, it generates an input event that
414 includes an scan code. If a key is mapped to anything else, it will
415 generate input device EV_KEY events.
417 Non hot-key ACPI HKEY event map:
420 0x7000 Radio Switch may have changed state
422 The above events are not propagated by the driver, except for legacy
423 compatibility purposes when hotkey_report_mode is set to 1.
427 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
428 supported the input layer, and sent events over the procfs ACPI event
431 To avoid sending duplicate events over the input layer and the ACPI
432 event interface, thinkpad-acpi 0.16 implements a module parameter
433 (hotkey_report_mode), and also a sysfs device attribute with the same
436 Make no mistake here: userspace is expected to switch to using the input
437 layer interface of thinkpad-acpi, together with the ACPI netlink event
438 interface in kernels 2.6.23 and later, or with the ACPI procfs event
439 interface in kernels 2.6.22 and earlier.
441 If no hotkey_report_mode module parameter is specified (or it is set to
442 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
443 and earlier, also allows one to change the hotkey_report_mode through
444 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
445 interface is available, hotkey_report_mode cannot be changed through
446 sysfs (it is read-only).
448 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
449 be changed later through sysfs (any writes will return -EPERM to signal
450 that hotkey_report_mode was locked. On 2.6.23 and later, where
451 hotkey_report_mode cannot be changed at all, writes will return -EACES).
453 hotkey_report_mode set to 1 makes the driver export through the procfs
454 ACPI event interface all hot key presses (which are *also* sent to the
455 input layer). This is a legacy compatibility behaviour, and it is also
456 the default mode of operation for the driver.
458 hotkey_report_mode set to 2 makes the driver filter out the hot key
459 presses from the procfs ACPI event interface, so these events will only
460 be sent through the input layer. Userspace that has been updated to use
461 the thinkpad-acpi input layer interface should set hotkey_report_mode to
464 Hot key press events are never sent to the ACPI netlink event interface.
465 Really up-to-date userspace under kernel 2.6.23 and later is to use the
466 netlink interface and the input layer interface, and don't bother at all
467 with hotkey_report_mode.
473 procfs: /proc/acpi/ibm/bluetooth
474 sysfs device attribute: bluetooth_enable
476 This feature shows the presence and current state of a ThinkPad
477 Bluetooth device in the internal ThinkPad CDC slot.
481 If Bluetooth is installed, the following commands can be used:
483 echo enable > /proc/acpi/ibm/bluetooth
484 echo disable > /proc/acpi/ibm/bluetooth
488 If the Bluetooth CDC card is installed, it can be enabled /
489 disabled through the "bluetooth_enable" thinkpad-acpi device
490 attribute, and its current status can also be queried.
493 0: disables Bluetooth / Bluetooth is disabled
494 1: enables Bluetooth / Bluetooth is enabled.
496 Note: this interface will be probably be superseeded by the
497 generic rfkill class, so it is NOT to be considered stable yet.
499 Video output control -- /proc/acpi/ibm/video
500 --------------------------------------------
502 This feature allows control over the devices used for video output -
503 LCD, CRT or DVI (if available). The following commands are available:
505 echo lcd_enable > /proc/acpi/ibm/video
506 echo lcd_disable > /proc/acpi/ibm/video
507 echo crt_enable > /proc/acpi/ibm/video
508 echo crt_disable > /proc/acpi/ibm/video
509 echo dvi_enable > /proc/acpi/ibm/video
510 echo dvi_disable > /proc/acpi/ibm/video
511 echo auto_enable > /proc/acpi/ibm/video
512 echo auto_disable > /proc/acpi/ibm/video
513 echo expand_toggle > /proc/acpi/ibm/video
514 echo video_switch > /proc/acpi/ibm/video
516 Each video output device can be enabled or disabled individually.
517 Reading /proc/acpi/ibm/video shows the status of each device.
519 Automatic video switching can be enabled or disabled. When automatic
520 video switching is enabled, certain events (e.g. opening the lid,
521 docking or undocking) cause the video output device to change
522 automatically. While this can be useful, it also causes flickering
523 and, on the X40, video corruption. By disabling automatic switching,
524 the flickering or video corruption can be avoided.
526 The video_switch command cycles through the available video outputs
527 (it simulates the behavior of Fn-F7).
529 Video expansion can be toggled through this feature. This controls
530 whether the display is expanded to fill the entire LCD screen when a
531 mode with less than full resolution is used. Note that the current
532 video expansion status cannot be determined through this feature.
534 Note that on many models (particularly those using Radeon graphics
535 chips) the X driver configures the video card in a way which prevents
536 Fn-F7 from working. This also disables the video output switching
537 features of this driver, as it uses the same ACPI methods as
538 Fn-F7. Video switching on the console should still work.
540 UPDATE: There's now a patch for the X.org Radeon driver which
541 addresses this issue. Some people are reporting success with the patch
542 while others are still having problems. For more information:
544 https://bugs.freedesktop.org/show_bug.cgi?id=2000
546 ThinkLight control -- /proc/acpi/ibm/light
547 ------------------------------------------
549 The current status of the ThinkLight can be found in this file. A few
550 models which do not make the status available will show it as
551 "unknown". The available commands are:
553 echo on > /proc/acpi/ibm/light
554 echo off > /proc/acpi/ibm/light
556 Docking / undocking -- /proc/acpi/ibm/dock
557 ------------------------------------------
559 Docking and undocking (e.g. with the X4 UltraBase) requires some
560 actions to be taken by the operating system to safely make or break
561 the electrical connections with the dock.
563 The docking feature of this driver generates the following ACPI events:
565 ibm/dock GDCK 00000003 00000001 -- eject request
566 ibm/dock GDCK 00000003 00000002 -- undocked
567 ibm/dock GDCK 00000000 00000003 -- docked
569 NOTE: These events will only be generated if the laptop was docked
570 when originally booted. This is due to the current lack of support for
571 hot plugging of devices in the Linux ACPI framework. If the laptop was
572 booted while not in the dock, the following message is shown in the
575 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
577 In this case, no dock-related events are generated but the dock and
578 undock commands described below still work. They can be executed
579 manually or triggered by Fn key combinations (see the example acpid
580 configuration files included in the driver tarball package available
583 When the eject request button on the dock is pressed, the first event
584 above is generated. The handler for this event should issue the
587 echo undock > /proc/acpi/ibm/dock
589 After the LED on the dock goes off, it is safe to eject the laptop.
590 Note: if you pressed this key by mistake, go ahead and eject the
591 laptop, then dock it back in. Otherwise, the dock may not function as
594 When the laptop is docked, the third event above is generated. The
595 handler for this event should issue the following command to fully
598 echo dock > /proc/acpi/ibm/dock
600 The contents of the /proc/acpi/ibm/dock file shows the current status
601 of the dock, as provided by the ACPI framework.
603 The docking support in this driver does not take care of enabling or
604 disabling any other devices you may have attached to the dock. For
605 example, a CD drive plugged into the UltraBase needs to be disabled or
606 enabled separately. See the provided example acpid configuration files
607 for how this can be accomplished.
609 There is no support yet for PCI devices that may be attached to a
610 docking station, e.g. in the ThinkPad Dock II. The driver currently
611 does not recognize, enable or disable such devices. This means that
612 the only docking stations currently supported are the X-series
613 UltraBase docks and "dumb" port replicators like the Mini Dock (the
614 latter don't need any ACPI support, actually).
616 UltraBay eject -- /proc/acpi/ibm/bay
617 ------------------------------------
619 Inserting or ejecting an UltraBay device requires some actions to be
620 taken by the operating system to safely make or break the electrical
621 connections with the device.
623 This feature generates the following ACPI events:
625 ibm/bay MSTR 00000003 00000000 -- eject request
626 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
628 NOTE: These events will only be generated if the UltraBay was present
629 when the laptop was originally booted (on the X series, the UltraBay
630 is in the dock, so it may not be present if the laptop was undocked).
631 This is due to the current lack of support for hot plugging of devices
632 in the Linux ACPI framework. If the laptop was booted without the
633 UltraBay, the following message is shown in the logs:
635 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
637 In this case, no bay-related events are generated but the eject
638 command described below still works. It can be executed manually or
639 triggered by a hot key combination.
641 Sliding the eject lever generates the first event shown above. The
642 handler for this event should take whatever actions are necessary to
643 shut down the device in the UltraBay (e.g. call idectl), then issue
644 the following command:
646 echo eject > /proc/acpi/ibm/bay
648 After the LED on the UltraBay goes off, it is safe to pull out the
651 When the eject lever is inserted, the second event above is
652 generated. The handler for this event should take whatever actions are
653 necessary to enable the UltraBay device (e.g. call idectl).
655 The contents of the /proc/acpi/ibm/bay file shows the current status
656 of the UltraBay, as provided by the ACPI framework.
658 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
659 this feature, you need to supply the experimental=1 parameter when
662 These models do not have a button near the UltraBay device to request
663 a hot eject but rather require the laptop to be put to sleep
664 (suspend-to-ram) before the bay device is ejected or inserted).
665 The sequence of steps to eject the device is as follows:
667 echo eject > /proc/acpi/ibm/bay
668 put the ThinkPad to sleep
671 cat /proc/acpi/ibm/bay should show that the drive was removed
673 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
674 supported. Use "eject2" instead of "eject" for the second bay.
676 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
677 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
682 procfs: /proc/acpi/ibm/cmos
683 sysfs device attribute: cmos_command
685 This feature is mostly used internally by the ACPI firmware to keep the legacy
686 CMOS NVRAM bits in sync with the current machine state, and to record this
687 state so that the ThinkPad will retain such settings across reboots.
689 Some of these commands actually perform actions in some ThinkPad models, but
690 this is expected to disappear more and more in newer models. As an example, in
691 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
692 real, but commands 0 to 2 don't control the mixer anymore (they have been
693 phased out) and just update the NVRAM.
695 The range of valid cmos command numbers is 0 to 21, but not all have an
696 effect and the behavior varies from model to model. Here is the behavior
697 on the X40 (tpb is the ThinkPad Buttons utility):
699 0 - Related to "Volume down" key press
700 1 - Related to "Volume up" key press
701 2 - Related to "Mute on" key press
702 3 - Related to "Access IBM" key press
703 4 - Related to "LCD brightness up" key pess
704 5 - Related to "LCD brightness down" key press
705 11 - Related to "toggle screen expansion" key press/function
706 12 - Related to "ThinkLight on"
707 13 - Related to "ThinkLight off"
708 14 - Related to "ThinkLight" key press (toggle thinklight)
710 The cmos command interface is prone to firmware split-brain problems, as
711 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
712 exported just as a debug tool.
714 LED control -- /proc/acpi/ibm/led
715 ---------------------------------
717 Some of the LED indicators can be controlled through this feature. The
718 available commands are:
720 echo '<led number> on' >/proc/acpi/ibm/led
721 echo '<led number> off' >/proc/acpi/ibm/led
722 echo '<led number> blink' >/proc/acpi/ibm/led
724 The <led number> range is 0 to 7. The set of LEDs that can be
725 controlled varies from model to model. Here is the mapping on the X40:
734 All of the above can be turned on and off and can be made to blink.
736 ACPI sounds -- /proc/acpi/ibm/beep
737 ----------------------------------
739 The BEEP method is used internally by the ACPI firmware to provide
740 audible alerts in various situations. This feature allows the same
741 sounds to be triggered manually.
743 The commands are non-negative integer numbers:
745 echo <number> >/proc/acpi/ibm/beep
747 The valid <number> range is 0 to 17. Not all numbers trigger sounds
748 and the sounds vary from model to model. Here is the behavior on the
751 0 - stop a sound in progress (but use 17 to stop 16)
752 2 - two beeps, pause, third beep ("low battery")
754 4 - high, followed by low-pitched beep ("unable")
756 6 - very high, followed by high-pitched beep ("AC/DC")
757 7 - high-pitched beep
758 9 - three short beeps
760 12 - low-pitched beep
761 15 - three high-pitched beeps repeating constantly, stop with 0
762 16 - one medium-pitched beep repeating constantly, stop with 17
768 procfs: /proc/acpi/ibm/thermal
769 sysfs device attributes: (hwmon) temp*_input
771 Most ThinkPads include six or more separate temperature sensors but only
772 expose the CPU temperature through the standard ACPI methods. This
773 feature shows readings from up to eight different sensors on older
774 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
776 For example, on the X40, a typical output may be:
777 temperatures: 42 42 45 41 36 -128 33 -128
779 On the T43/p, a typical output may be:
780 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
782 The mapping of thermal sensors to physical locations varies depending on
783 system-board model (and thus, on ThinkPad model).
785 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
786 tries to track down these locations for various models.
788 Most (newer?) models seem to follow this pattern:
791 2: (depends on model)
792 3: (depends on model)
794 5: Main battery: main sensor
795 6: Bay battery: main sensor
796 7: Main battery: secondary sensor
797 8: Bay battery: secondary sensor
798 9-15: (depends on model)
800 For the R51 (source: Thomas Gruber):
804 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
805 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
806 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
808 9: MCH (northbridge) to DRAM Bus
809 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
811 11: Power regulator, underside of system board, below F2 key
813 The A31 has a very atypical layout for the thermal sensors
814 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
816 2: Main Battery: main sensor
818 4: Bay Battery: main sensor
821 7: Main Battery: secondary sensor
822 8: Bay Battery: secondary sensor
826 Readings from sensors that are not available return -128.
827 No commands can be written to this file.
830 Sensors that are not available return the ENXIO error. This
831 status may change at runtime, as there are hotplug thermal
832 sensors, like those inside the batteries and docks.
834 thinkpad-acpi thermal sensors are reported through the hwmon
835 subsystem, and follow all of the hwmon guidelines at
839 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
840 ------------------------------------------------------------------------
842 This feature is marked EXPERIMENTAL because the implementation
843 directly accesses hardware registers and may not work as expected. USE
844 WITH CAUTION! To use this feature, you need to supply the
845 experimental=1 parameter when loading the module.
847 This feature dumps the values of 256 embedded controller
848 registers. Values which have changed since the last time the registers
849 were dumped are marked with a star:
851 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
852 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
853 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
854 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
855 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
856 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
857 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
858 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
859 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
860 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
861 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
862 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
863 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
864 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
865 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
866 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
867 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
868 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
870 This feature can be used to determine the register holding the fan
871 speed on some models. To do that, do the following:
873 - make sure the battery is fully charged
874 - make sure the fan is running
875 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
877 The first step makes sure various charging-related values don't
878 vary. The second ensures that the fan-related values do vary, since
879 the fan speed fluctuates a bit. The third will (hopefully) mark the
880 fan register with a star:
882 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
883 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
884 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
885 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
886 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
887 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
888 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
889 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
890 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
891 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
892 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
893 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
894 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
895 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
896 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
897 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
898 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
899 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
901 Another set of values that varies often is the temperature
902 readings. Since temperatures don't change vary fast, you can take
903 several quick dumps to eliminate them.
905 You can use a similar method to figure out the meaning of other
906 embedded controller registers - e.g. make sure nothing else changes
907 except the charging or discharging battery to determine which
908 registers contain the current battery capacity, etc. If you experiment
909 with this, do send me your results (including some complete dumps with
910 a description of the conditions when they were taken.)
912 LCD brightness control
913 ----------------------
915 procfs: /proc/acpi/ibm/brightness
916 sysfs backlight device "thinkpad_screen"
918 This feature allows software control of the LCD brightness on ThinkPad
919 models which don't have a hardware brightness slider.
921 It has some limitations: the LCD backlight cannot be actually turned on or off
922 by this interface, and in many ThinkPad models, the "dim while on battery"
923 functionality will be enabled by the BIOS when this interface is used, and
924 cannot be controlled.
926 The backlight control has eight levels, ranging from 0 to 7. Some of the
927 levels may not be distinct.
929 There are two interfaces to the firmware for brightness control, EC and CMOS.
930 To select which one should be used, use the brightness_mode module parameter:
931 brightness_mode=1 selects EC mode, brightness_mode=2 selects CMOS mode,
932 brightness_mode=3 selects both EC and CMOS. The driver tries to autodetect
933 which interface to use.
937 The available commands are:
939 echo up >/proc/acpi/ibm/brightness
940 echo down >/proc/acpi/ibm/brightness
941 echo 'level <level>' >/proc/acpi/ibm/brightness
945 The interface is implemented through the backlight sysfs class, which is poorly
946 documented at this time.
948 Locate the thinkpad_screen device under /sys/class/backlight, and inside it
949 there will be the following attributes:
952 Reads the maximum brightness the hardware can be set to.
953 The minimum is always zero.
956 Reads what brightness the screen is set to at this instant.
959 Writes request the driver to change brightness to the given
960 value. Reads will tell you what brightness the driver is trying
961 to set the display to when "power" is set to zero and the display
962 has not been dimmed by a kernel power management event.
965 power management mode, where 0 is "display on", and 1 to 3 will
966 dim the display backlight to brightness level 0 because
967 thinkpad-acpi cannot really turn the backlight off. Kernel
968 power management events can temporarily increase the current
969 power management level, i.e. they can dim the display.
972 Volume control -- /proc/acpi/ibm/volume
973 ---------------------------------------
975 This feature allows volume control on ThinkPad models which don't have
976 a hardware volume knob. The available commands are:
978 echo up >/proc/acpi/ibm/volume
979 echo down >/proc/acpi/ibm/volume
980 echo mute >/proc/acpi/ibm/volume
981 echo 'level <level>' >/proc/acpi/ibm/volume
983 The <level> number range is 0 to 15 although not all of them may be
984 distinct. The unmute the volume after the mute command, use either the
985 up or down command (the level command will not unmute the volume).
986 The current volume level and mute state is shown in the file.
988 Fan control and monitoring: fan speed, fan enable/disable
989 ---------------------------------------------------------
991 procfs: /proc/acpi/ibm/fan
992 sysfs device attributes: (hwmon) fan_input, pwm1, pwm1_enable
994 NOTE NOTE NOTE: fan control operations are disabled by default for
995 safety reasons. To enable them, the module parameter "fan_control=1"
996 must be given to thinkpad-acpi.
998 This feature attempts to show the current fan speed, control mode and
999 other fan data that might be available. The speed is read directly
1000 from the hardware registers of the embedded controller. This is known
1001 to work on later R, T, X and Z series ThinkPads but may show a bogus
1002 value on other models.
1006 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1007 stops the fan. The higher the level, the higher the fan speed, although
1008 adjacent levels often map to the same fan speed. 7 is the highest
1009 level, where the fan reaches the maximum recommended speed.
1011 Level "auto" means the EC changes the fan level according to some
1012 internal algorithm, usually based on readings from the thermal sensors.
1014 There is also a "full-speed" level, also known as "disengaged" level.
1015 In this level, the EC disables the speed-locked closed-loop fan control,
1016 and drives the fan as fast as it can go, which might exceed hardware
1017 limits, so use this level with caution.
1019 The fan usually ramps up or down slowly from one speed to another, and
1020 it is normal for the EC to take several seconds to react to fan
1021 commands. The full-speed level may take up to two minutes to ramp up to
1022 maximum speed, and in some ThinkPads, the tachometer readings go stale
1023 while the EC is transitioning to the full-speed level.
1025 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1026 monitoring all of the temperature sensor readings and you are ready to
1027 enable it if necessary to avoid overheating.
1029 An enabled fan in level "auto" may stop spinning if the EC decides the
1030 ThinkPad is cool enough and doesn't need the extra airflow. This is
1031 normal, and the EC will spin the fan up if the varios thermal readings
1034 On the X40, this seems to depend on the CPU and HDD temperatures.
1035 Specifically, the fan is turned on when either the CPU temperature
1036 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1037 fan is turned off when the CPU temperature drops to 49 degrees and the
1038 HDD temperature drops to 41 degrees. These thresholds cannot
1039 currently be controlled.
1041 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1042 certain conditions are met. It will override any fan programming done
1043 through thinkpad-acpi.
1045 The thinkpad-acpi kernel driver can be programmed to revert the fan
1046 level to a safe setting if userspace does not issue one of the procfs
1047 fan commands: "enable", "disable", "level" or "watchdog", or if there
1048 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1049 set to 1, manual mode) within a configurable amount of time of up to
1050 120 seconds. This functionality is called fan safety watchdog.
1052 Note that the watchdog timer stops after it enables the fan. It will be
1053 rearmed again automatically (using the same interval) when one of the
1054 above mentioned fan commands is received. The fan watchdog is,
1055 therefore, not suitable to protect against fan mode changes made through
1056 means other than the "enable", "disable", and "level" procfs fan
1057 commands, or the hwmon fan control sysfs interface.
1061 The fan may be enabled or disabled with the following commands:
1063 echo enable >/proc/acpi/ibm/fan
1064 echo disable >/proc/acpi/ibm/fan
1066 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1067 will try to place it in a safe level if it is too slow or disabled.
1069 The fan level can be controlled with the command:
1071 echo 'level <level>' > /proc/acpi/ibm/fan
1073 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1074 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1075 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1076 "full-speed", and reports it as "disengaged" for backwards
1079 On the X31 and X40 (and ONLY on those models), the fan speed can be
1080 controlled to a certain degree. Once the fan is running, it can be
1081 forced to run faster or slower with the following command:
1083 echo 'speed <speed>' > /proc/acpi/ibm/fan
1085 The sustainable range of fan speeds on the X40 appears to be from about
1086 3700 to about 7350. Values outside this range either do not have any
1087 effect or the fan speed eventually settles somewhere in that range. The
1088 fan cannot be stopped or started with this command. This functionality
1089 is incomplete, and not available through the sysfs interface.
1091 To program the safety watchdog, use the "watchdog" command.
1093 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1095 If you want to disable the watchdog, use 0 as the interval.
1099 The sysfs interface follows the hwmon subsystem guidelines for the most
1100 part, and the exception is the fan safety watchdog.
1102 Writes to any of the sysfs attributes may return the EINVAL error if
1103 that operation is not supported in a given ThinkPad or if the parameter
1104 is out-of-bounds, and EPERM if it is forbidden. They may also return
1105 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1108 Features not yet implemented by the driver return ENOSYS.
1110 hwmon device attribute pwm1_enable:
1111 0: PWM offline (fan is set to full-speed mode)
1112 1: Manual PWM control (use pwm1 to set fan level)
1113 2: Hardware PWM control (EC "auto" mode)
1114 3: reserved (Software PWM control, not implemented yet)
1116 Modes 0 and 2 are not supported by all ThinkPads, and the
1117 driver is not always able to detect this. If it does know a
1118 mode is unsupported, it will return -EINVAL.
1120 hwmon device attribute pwm1:
1121 Fan level, scaled from the firmware values of 0-7 to the hwmon
1122 scale of 0-255. 0 means fan stopped, 255 means highest normal
1125 This attribute only commands the fan if pmw1_enable is set to 1
1126 (manual PWM control).
1128 hwmon device attribute fan1_input:
1129 Fan tachometer reading, in RPM. May go stale on certain
1130 ThinkPads while the EC transitions the PWM to offline mode,
1131 which can take up to two minutes. May return rubbish on older
1134 driver attribute fan_watchdog:
1135 Fan safety watchdog timer interval, in seconds. Minimum is
1136 1 second, maximum is 120 seconds. 0 disables the watchdog.
1138 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1140 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1141 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1142 would be the safest choice, though).
1148 procfs: /proc/acpi/ibm/wan
1149 sysfs device attribute: wwan_enable
1151 This feature is marked EXPERIMENTAL because the implementation
1152 directly accesses hardware registers and may not work as expected. USE
1153 WITH CAUTION! To use this feature, you need to supply the
1154 experimental=1 parameter when loading the module.
1156 This feature shows the presence and current state of a W-WAN (Sierra
1157 Wireless EV-DO) device.
1159 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1160 Thinkpad models which come with this module installed.
1164 If the W-WAN card is installed, the following commands can be used:
1166 echo enable > /proc/acpi/ibm/wan
1167 echo disable > /proc/acpi/ibm/wan
1171 If the W-WAN card is installed, it can be enabled /
1172 disabled through the "wwan_enable" thinkpad-acpi device
1173 attribute, and its current status can also be queried.
1176 0: disables WWAN card / WWAN card is disabled
1177 1: enables WWAN card / WWAN card is enabled.
1179 Note: this interface will be probably be superseeded by the
1180 generic rfkill class, so it is NOT to be considered stable yet.
1182 Multiple Commands, Module Parameters
1183 ------------------------------------
1185 Multiple commands can be written to the proc files in one shot by
1186 separating them with commas, for example:
1188 echo enable,0xffff > /proc/acpi/ibm/hotkey
1189 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1191 Commands can also be specified when loading the thinkpad-acpi module,
1194 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1196 Enabling debugging output
1197 -------------------------
1199 The module takes a debug paramater which can be used to selectively
1200 enable various classes of debugging output, for example:
1202 modprobe ibm_acpi debug=0xffff
1204 will enable all debugging output classes. It takes a bitmask, so
1205 to enable more than one output class, just add their values.
1207 Debug bitmask Description
1208 0x0001 Initialization and probing
1211 There is also a kernel build option to enable more debugging
1212 information, which may be necessary to debug driver problems.
1214 The level of debugging information output by the driver can be changed
1215 at runtime through sysfs, using the driver attribute debug_level. The
1216 attribute takes the same bitmask as the debug module parameter above.
1218 Force loading of module
1219 -----------------------
1221 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1222 the module parameter force_load=1. Regardless of whether this works or
1223 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1226 Sysfs interface changelog:
1228 0x000100: Initial sysfs support, as a single platform driver and
1230 0x000200: Hot key support for 32 hot keys, and radio slider switch
1232 0x010000: Hot keys are now handled by default over the input
1233 layer, the radio switch generates input event EV_RADIO,
1234 and the driver enables hot key handling by default in
projects / linux-2.6 / blob