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1 ThinkPad ACPI Extras Driver
3 Version 0.23
4 April 10th, 2009
6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
8 http://ibm-acpi.sf.net/
11 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
12 supports various features of these laptops which are accessible
13 through the ACPI and ACPI EC framework, but not otherwise fully
14 supported by the generic Linux ACPI drivers.
16 This driver used to be named ibm-acpi until kernel 2.6.21 and release
17 0.13-20070314. It used to be in the drivers/acpi tree, but it was
18 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
19 2.6.22, and release 0.14. It was moved to drivers/platform/x86 for
20 kernel 2.6.29 and release 0.22.
22 The driver is named "thinkpad-acpi". In some places, like module
23 names and log messages, "thinkpad_acpi" is used because of userspace
24 issues.
26 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
27 long due to length limitations on some Linux kernel versions.
29 Status
30 ------
32 The features currently supported are the following (see below for
33 detailed description):
35 - Fn key combinations
36 - Bluetooth enable and disable
37 - video output switching, expansion control
38 - ThinkLight on and off
39 - limited docking and undocking
40 - UltraBay eject
41 - CMOS/UCMS control
42 - LED control
43 - ACPI sounds
44 - temperature sensors
45 - Experimental: embedded controller register dump
46 - LCD brightness control
47 - Volume control
48 - Fan control and monitoring: fan speed, fan enable/disable
49 - WAN enable and disable
50 - UWB enable and disable
52 A compatibility table by model and feature is maintained on the web
53 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
54 reports, especially if they add to or correct the compatibility table.
55 Please include the following information in your report:
57 - ThinkPad model name
58 - a copy of your ACPI tables, using the "acpidump" utility
59 - a copy of the output of dmidecode, with serial numbers
60 and UUIDs masked off
61 - which driver features work and which don't
62 - the observed behavior of non-working features
64 Any other comments or patches are also more than welcome.
67 Installation
68 ------------
70 If you are compiling this driver as included in the Linux kernel
71 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
72 It is located on the menu path: "Device Drivers" -> "X86 Platform
73 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
76 Features
77 --------
79 The driver exports two different interfaces to userspace, which can be
80 used to access the features it provides. One is a legacy procfs-based
81 interface, which will be removed at some time in the future. The other
82 is a new sysfs-based interface which is not complete yet.
84 The procfs interface creates the /proc/acpi/ibm directory. There is a
85 file under that directory for each feature it supports. The procfs
86 interface is mostly frozen, and will change very little if at all: it
87 will not be extended to add any new functionality in the driver, instead
88 all new functionality will be implemented on the sysfs interface.
90 The sysfs interface tries to blend in the generic Linux sysfs subsystems
91 and classes as much as possible. Since some of these subsystems are not
92 yet ready or stabilized, it is expected that this interface will change,
93 and any and all userspace programs must deal with it.
96 Notes about the sysfs interface:
98 Unlike what was done with the procfs interface, correctness when talking
99 to the sysfs interfaces will be enforced, as will correctness in the
100 thinkpad-acpi's implementation of sysfs interfaces.
102 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
103 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
104 maximum correctness, even if that means changing an interface in
105 non-compatible ways. As these interfaces mature both in the kernel and
106 in thinkpad-acpi, such changes should become quite rare.
108 Applications interfacing to the thinkpad-acpi sysfs interfaces must
109 follow all sysfs guidelines and correctly process all errors (the sysfs
110 interface makes extensive use of errors). File descriptors and open /
111 close operations to the sysfs inodes must also be properly implemented.
113 The version of thinkpad-acpi's sysfs interface is exported by the driver
114 as a driver attribute (see below).
116 Sysfs driver attributes are on the driver's sysfs attribute space,
117 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
118 /sys/bus/platform/drivers/thinkpad_hwmon/
120 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
121 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
123 Sysfs device attributes for the sensors and fan are on the
124 thinkpad_hwmon device's sysfs attribute space, but you should locate it
125 looking for a hwmon device with the name attribute of "thinkpad", or
126 better yet, through libsensors.
129 Driver version
130 --------------
132 procfs: /proc/acpi/ibm/driver
133 sysfs driver attribute: version
135 The driver name and version. No commands can be written to this file.
138 Sysfs interface version
139 -----------------------
141 sysfs driver attribute: interface_version
143 Version of the thinkpad-acpi sysfs interface, as an unsigned long
144 (output in hex format: 0xAAAABBCC), where:
145 AAAA - major revision
146 BB - minor revision
147 CC - bugfix revision
149 The sysfs interface version changelog for the driver can be found at the
150 end of this document. Changes to the sysfs interface done by the kernel
151 subsystems are not documented here, nor are they tracked by this
152 attribute.
154 Changes to the thinkpad-acpi sysfs interface are only considered
155 non-experimental when they are submitted to Linux mainline, at which
156 point the changes in this interface are documented and interface_version
157 may be updated. If you are using any thinkpad-acpi features not yet
158 sent to mainline for merging, you do so on your own risk: these features
159 may disappear, or be implemented in a different and incompatible way by
160 the time they are merged in Linux mainline.
162 Changes that are backwards-compatible by nature (e.g. the addition of
163 attributes that do not change the way the other attributes work) do not
164 always warrant an update of interface_version. Therefore, one must
165 expect that an attribute might not be there, and deal with it properly
166 (an attribute not being there *is* a valid way to make it clear that a
167 feature is not available in sysfs).
170 Hot keys
171 --------
173 procfs: /proc/acpi/ibm/hotkey
174 sysfs device attribute: hotkey_*
176 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
177 some important events and also keyboard hot key presses to the operating
178 system. Enabling the hotkey functionality of thinkpad-acpi signals the
179 firmware that such a driver is present, and modifies how the ThinkPad
180 firmware will behave in many situations.
182 The driver enables the HKEY ("hot key") event reporting automatically
183 when loaded, and disables it when it is removed.
185 The driver will report HKEY events in the following format:
187 ibm/hotkey HKEY 00000080 0000xxxx
189 Some of these events refer to hot key presses, but not all of them.
191 The driver will generate events over the input layer for hot keys and
192 radio switches, and over the ACPI netlink layer for other events. The
193 input layer support accepts the standard IOCTLs to remap the keycodes
194 assigned to each hot key.
196 The hot key bit mask allows some control over which hot keys generate
197 events. If a key is "masked" (bit set to 0 in the mask), the firmware
198 will handle it. If it is "unmasked", it signals the firmware that
199 thinkpad-acpi would prefer to handle it, if the firmware would be so
200 kind to allow it (and it often doesn't!).
202 Not all bits in the mask can be modified. Not all bits that can be
203 modified do anything. Not all hot keys can be individually controlled
204 by the mask. Some models do not support the mask at all, and in those
205 models, hot keys cannot be controlled individually. The behaviour of
206 the mask is, therefore, highly dependent on the ThinkPad model.
208 Note that unmasking some keys prevents their default behavior. For
209 example, if Fn+F5 is unmasked, that key will no longer enable/disable
210 Bluetooth by itself.
212 Note also that not all Fn key combinations are supported through ACPI.
213 For example, on the X40, the brightness, volume and "Access IBM" buttons
214 do not generate ACPI events even with this driver. They *can* be used
215 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
217 procfs notes:
219 The following commands can be written to the /proc/acpi/ibm/hotkey file:
221 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
222 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
223 ... any other 8-hex-digit mask ...
224 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
226 The following commands have been deprecated and will cause the kernel
227 to log a warning:
229 echo enable > /proc/acpi/ibm/hotkey -- does nothing
230 echo disable > /proc/acpi/ibm/hotkey -- returns an error
232 The procfs interface does not support NVRAM polling control. So as to
233 maintain maximum bug-to-bug compatibility, it does not report any masks,
234 nor does it allow one to manipulate the hot key mask when the firmware
235 does not support masks at all, even if NVRAM polling is in use.
237 sysfs notes:
239 hotkey_bios_enabled:
240 DEPRECATED, WILL BE REMOVED SOON.
242 Returns 0.
244 hotkey_bios_mask:
245 Returns the hot keys mask when thinkpad-acpi was loaded.
246 Upon module unload, the hot keys mask will be restored
247 to this value.
249 hotkey_enable:
250 DEPRECATED, WILL BE REMOVED SOON.
252 0: returns -EPERM
253 1: does nothing
255 hotkey_mask:
256 bit mask to enable driver-handling (and depending on
257 the firmware, ACPI event generation) for each hot key
258 (see above). Returns the current status of the hot keys
259 mask, and allows one to modify it.
261 Note: when NVRAM polling is active, the firmware mask
262 will be different from the value returned by
263 hotkey_mask. The driver will retain enabled bits for
264 hotkeys that are under NVRAM polling even if the
265 firmware refuses them, and will not set these bits on
266 the firmware hot key mask.
268 hotkey_all_mask:
269 bit mask that should enable event reporting for all
270 supported hot keys, when echoed to hotkey_mask above.
271 Unless you know which events need to be handled
272 passively (because the firmware *will* handle them
273 anyway), do *not* use hotkey_all_mask. Use
274 hotkey_recommended_mask, instead. You have been warned.
276 hotkey_recommended_mask:
277 bit mask that should enable event reporting for all
278 supported hot keys, except those which are always
279 handled by the firmware anyway. Echo it to
280 hotkey_mask above, to use.
282 hotkey_source_mask:
283 bit mask that selects which hot keys will the driver
284 poll the NVRAM for. This is auto-detected by the driver
285 based on the capabilities reported by the ACPI firmware,
286 but it can be overridden at runtime.
288 Hot keys whose bits are set in both hotkey_source_mask
289 and also on hotkey_mask are polled for in NVRAM. Only a
290 few hot keys are available through CMOS NVRAM polling.
292 Warning: when in NVRAM mode, the volume up/down/mute
293 keys are synthesized according to changes in the mixer,
294 so you have to use volume up or volume down to unmute,
295 as per the ThinkPad volume mixer user interface. When
296 in ACPI event mode, volume up/down/mute are reported as
297 separate events, but this behaviour may be corrected in
298 future releases of this driver, in which case the
299 ThinkPad volume mixer user interface semantics will be
300 enforced.
302 hotkey_poll_freq:
303 frequency in Hz for hot key polling. It must be between
304 0 and 25 Hz. Polling is only carried out when strictly
305 needed.
307 Setting hotkey_poll_freq to zero disables polling, and
308 will cause hot key presses that require NVRAM polling
309 to never be reported.
311 Setting hotkey_poll_freq too low will cause repeated
312 pressings of the same hot key to be misreported as a
313 single key press, or to not even be detected at all.
314 The recommended polling frequency is 10Hz.
316 hotkey_radio_sw:
317 If the ThinkPad has a hardware radio switch, this
318 attribute will read 0 if the switch is in the "radios
319 disabled" position, and 1 if the switch is in the
320 "radios enabled" position.
322 This attribute has poll()/select() support.
324 hotkey_tablet_mode:
325 If the ThinkPad has tablet capabilities, this attribute
326 will read 0 if the ThinkPad is in normal mode, and
327 1 if the ThinkPad is in tablet mode.
329 This attribute has poll()/select() support.
331 hotkey_report_mode:
332 Returns the state of the procfs ACPI event report mode
333 filter for hot keys. If it is set to 1 (the default),
334 all hot key presses are reported both through the input
335 layer and also as ACPI events through procfs (but not
336 through netlink). If it is set to 2, hot key presses
337 are reported only through the input layer.
339 This attribute is read-only in kernels 2.6.23 or later,
340 and read-write on earlier kernels.
342 May return -EPERM (write access locked out by module
343 parameter) or -EACCES (read-only).
345 wakeup_reason:
346 Set to 1 if the system is waking up because the user
347 requested a bay ejection. Set to 2 if the system is
348 waking up because the user requested the system to
349 undock. Set to zero for normal wake-ups or wake-ups
350 due to unknown reasons.
352 This attribute has poll()/select() support.
354 wakeup_hotunplug_complete:
355 Set to 1 if the system was waken up because of an
356 undock or bay ejection request, and that request
357 was successfully completed. At this point, it might
358 be useful to send the system back to sleep, at the
359 user's choice. Refer to HKEY events 0x4003 and
360 0x3003, below.
362 This attribute has poll()/select() support.
364 input layer notes:
366 A Hot key is mapped to a single input layer EV_KEY event, possibly
367 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
368 code. An EV_SYN event will always be generated to mark the end of the
369 event block.
371 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
372 used as a helper to remap keys, only. They are particularly useful when
373 remapping KEY_UNKNOWN keys.
375 The events are available in an input device, with the following id:
377 Bus: BUS_HOST
378 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
379 0x17aa (PCI_VENDOR_ID_LENOVO)
380 product: 0x5054 ("TP")
381 version: 0x4101
383 The version will have its LSB incremented if the keymap changes in a
384 backwards-compatible way. The MSB shall always be 0x41 for this input
385 device. If the MSB is not 0x41, do not use the device as described in
386 this section, as it is either something else (e.g. another input device
387 exported by a thinkpad driver, such as HDAPS) or its functionality has
388 been changed in a non-backwards compatible way.
390 Adding other event types for other functionalities shall be considered a
391 backwards-compatible change for this input device.
393 Thinkpad-acpi Hot Key event map (version 0x4101):
395 ACPI Scan
396 event code Key Notes
398 0x1001 0x00 FN+F1 -
399 0x1002 0x01 FN+F2 IBM: battery (rare)
400 Lenovo: Screen lock
402 0x1003 0x02 FN+F3 Many IBM models always report
403 this hot key, even with hot keys
404 disabled or with Fn+F3 masked
405 off
406 IBM: screen lock
407 Lenovo: battery
409 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
410 semantics, i.e. sleep-to-RAM).
411 It is always generate some kind
412 of event, either the hot key
413 event or a ACPI sleep button
414 event. The firmware may
415 refuse to generate further FN+F4
416 key presses until a S3 or S4 ACPI
417 sleep cycle is performed or some
418 time passes.
420 0x1005 0x04 FN+F5 Radio. Enables/disables
421 the internal Bluetooth hardware
422 and W-WAN card if left in control
423 of the firmware. Does not affect
424 the WLAN card.
425 Should be used to turn on/off all
426 radios (Bluetooth+W-WAN+WLAN),
427 really.
429 0x1006 0x05 FN+F6 -
431 0x1007 0x06 FN+F7 Video output cycle.
432 Do you feel lucky today?
434 0x1008 0x07 FN+F8 IBM: toggle screen expand
435 Lenovo: configure UltraNav
437 0x1009 0x08 FN+F9 -
438 .. .. ..
439 0x100B 0x0A FN+F11 -
441 0x100C 0x0B FN+F12 Sleep to disk. You are always
442 supposed to handle it yourself,
443 either through the ACPI event,
444 or through a hotkey event.
445 The firmware may refuse to
446 generate further FN+F4 key
447 press events until a S3 or S4
448 ACPI sleep cycle is performed,
449 or some time passes.
451 0x100D 0x0C FN+BACKSPACE -
452 0x100E 0x0D FN+INSERT -
453 0x100F 0x0E FN+DELETE -
455 0x1010 0x0F FN+HOME Brightness up. This key is
456 always handled by the firmware
457 in IBM ThinkPads, even when
458 unmasked. Just leave it alone.
459 For Lenovo ThinkPads with a new
460 BIOS, it has to be handled either
461 by the ACPI OSI, or by userspace.
462 0x1011 0x10 FN+END Brightness down. See brightness
463 up for details.
465 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
466 always handled by the firmware,
467 even when unmasked.
469 0x1013 0x12 FN+PGDOWN -
471 0x1014 0x13 FN+SPACE Zoom key
473 0x1015 0x14 VOLUME UP Internal mixer volume up. This
474 key is always handled by the
475 firmware, even when unmasked.
476 NOTE: Lenovo seems to be changing
477 this.
478 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
479 key is always handled by the
480 firmware, even when unmasked.
481 NOTE: Lenovo seems to be changing
482 this.
483 0x1017 0x16 MUTE Mute internal mixer. This
484 key is always handled by the
485 firmware, even when unmasked.
487 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
489 0x1019 0x18 unknown
490 .. .. ..
491 0x1020 0x1F unknown
493 The ThinkPad firmware does not allow one to differentiate when most hot
494 keys are pressed or released (either that, or we don't know how to, yet).
495 For these keys, the driver generates a set of events for a key press and
496 immediately issues the same set of events for a key release. It is
497 unknown by the driver if the ThinkPad firmware triggered these events on
498 hot key press or release, but the firmware will do it for either one, not
499 both.
501 If a key is mapped to KEY_RESERVED, it generates no input events at all.
502 If a key is mapped to KEY_UNKNOWN, it generates an input event that
503 includes an scan code. If a key is mapped to anything else, it will
504 generate input device EV_KEY events.
506 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
507 events for switches:
509 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
510 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
512 Non hot-key ACPI HKEY event map:
513 0x5001 Lid closed
514 0x5002 Lid opened
515 0x5009 Tablet swivel: switched to tablet mode
516 0x500A Tablet swivel: switched to normal mode
517 0x7000 Radio Switch may have changed state
519 The above events are not propagated by the driver, except for legacy
520 compatibility purposes when hotkey_report_mode is set to 1.
522 0x2304 System is waking up from suspend to undock
523 0x2305 System is waking up from suspend to eject bay
524 0x2404 System is waking up from hibernation to undock
525 0x2405 System is waking up from hibernation to eject bay
527 The above events are never propagated by the driver.
529 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
530 0x4003 Undocked (see 0x2x04), can sleep again
531 0x500B Tablet pen inserted into its storage bay
532 0x500C Tablet pen removed from its storage bay
533 0x5010 Brightness level changed (newer Lenovo BIOSes)
535 The above events are propagated by the driver.
537 Compatibility notes:
539 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
540 supported the input layer, and sent events over the procfs ACPI event
541 interface.
543 To avoid sending duplicate events over the input layer and the ACPI
544 event interface, thinkpad-acpi 0.16 implements a module parameter
545 (hotkey_report_mode), and also a sysfs device attribute with the same
546 name.
548 Make no mistake here: userspace is expected to switch to using the input
549 layer interface of thinkpad-acpi, together with the ACPI netlink event
550 interface in kernels 2.6.23 and later, or with the ACPI procfs event
551 interface in kernels 2.6.22 and earlier.
553 If no hotkey_report_mode module parameter is specified (or it is set to
554 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
555 and earlier, also allows one to change the hotkey_report_mode through
556 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
557 interface is available, hotkey_report_mode cannot be changed through
558 sysfs (it is read-only).
560 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
561 be changed later through sysfs (any writes will return -EPERM to signal
562 that hotkey_report_mode was locked. On 2.6.23 and later, where
563 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
565 hotkey_report_mode set to 1 makes the driver export through the procfs
566 ACPI event interface all hot key presses (which are *also* sent to the
567 input layer). This is a legacy compatibility behaviour, and it is also
568 the default mode of operation for the driver.
570 hotkey_report_mode set to 2 makes the driver filter out the hot key
571 presses from the procfs ACPI event interface, so these events will only
572 be sent through the input layer. Userspace that has been updated to use
573 the thinkpad-acpi input layer interface should set hotkey_report_mode to
574 2.
576 Hot key press events are never sent to the ACPI netlink event interface.
577 Really up-to-date userspace under kernel 2.6.23 and later is to use the
578 netlink interface and the input layer interface, and don't bother at all
579 with hotkey_report_mode.
582 Brightness hotkey notes:
584 These are the current sane choices for brightness key mapping in
585 thinkpad-acpi:
587 For IBM and Lenovo models *without* ACPI backlight control (the ones on
588 which thinkpad-acpi will autoload its backlight interface by default,
589 and on which ACPI video does not export a backlight interface):
591 1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as
592 these older firmware versions unfortunately won't respect the hotkey
593 mask for brightness keys anyway, and always reacts to them. This
594 usually work fine, unless X.org drivers are doing something to block
595 the BIOS. In that case, use (3) below. This is the default mode of
596 operation.
598 2. Enable the hotkeys, but map them to something else that is NOT
599 KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause
600 userspace to try to change the backlight level, and use that as an
601 on-screen-display hint.
603 3. IF AND ONLY IF X.org drivers find a way to block the firmware from
604 automatically changing the brightness, enable the hotkeys and map
605 them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to
606 something that calls xbacklight. thinkpad-acpi will not be able to
607 change brightness in that case either, so you should disable its
608 backlight interface.
610 For Lenovo models *with* ACPI backlight control:
612 1. Load up ACPI video and use that. ACPI video will report ACPI
613 events for brightness change keys. Do not mess with thinkpad-acpi
614 defaults in this case. thinkpad-acpi should not have anything to do
615 with backlight events in a scenario where ACPI video is loaded:
616 brightness hotkeys must be disabled, and the backlight interface is
617 to be kept disabled as well. This is the default mode of operation.
619 2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
620 and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN. Process
621 these keys on userspace somehow (e.g. by calling xbacklight).
624 Bluetooth
625 ---------
627 procfs: /proc/acpi/ibm/bluetooth
628 sysfs device attribute: bluetooth_enable (deprecated)
629 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
631 This feature shows the presence and current state of a ThinkPad
632 Bluetooth device in the internal ThinkPad CDC slot.
634 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
635 so it is kept across reboots and power-off.
637 Procfs notes:
639 If Bluetooth is installed, the following commands can be used:
641 echo enable > /proc/acpi/ibm/bluetooth
642 echo disable > /proc/acpi/ibm/bluetooth
644 Sysfs notes:
646 If the Bluetooth CDC card is installed, it can be enabled /
647 disabled through the "bluetooth_enable" thinkpad-acpi device
648 attribute, and its current status can also be queried.
650 enable:
651 0: disables Bluetooth / Bluetooth is disabled
652 1: enables Bluetooth / Bluetooth is enabled.
654 Note: this interface has been superseded by the generic rfkill
655 class. It has been deprecated, and it will be removed in year
656 2010.
658 rfkill controller switch "tpacpi_bluetooth_sw": refer to
659 Documentation/rfkill.txt for details.
662 Video output control -- /proc/acpi/ibm/video
663 --------------------------------------------
665 This feature allows control over the devices used for video output -
666 LCD, CRT or DVI (if available). The following commands are available:
668 echo lcd_enable > /proc/acpi/ibm/video
669 echo lcd_disable > /proc/acpi/ibm/video
670 echo crt_enable > /proc/acpi/ibm/video
671 echo crt_disable > /proc/acpi/ibm/video
672 echo dvi_enable > /proc/acpi/ibm/video
673 echo dvi_disable > /proc/acpi/ibm/video
674 echo auto_enable > /proc/acpi/ibm/video
675 echo auto_disable > /proc/acpi/ibm/video
676 echo expand_toggle > /proc/acpi/ibm/video
677 echo video_switch > /proc/acpi/ibm/video
679 Each video output device can be enabled or disabled individually.
680 Reading /proc/acpi/ibm/video shows the status of each device.
682 Automatic video switching can be enabled or disabled. When automatic
683 video switching is enabled, certain events (e.g. opening the lid,
684 docking or undocking) cause the video output device to change
685 automatically. While this can be useful, it also causes flickering
686 and, on the X40, video corruption. By disabling automatic switching,
687 the flickering or video corruption can be avoided.
689 The video_switch command cycles through the available video outputs
690 (it simulates the behavior of Fn-F7).
692 Video expansion can be toggled through this feature. This controls
693 whether the display is expanded to fill the entire LCD screen when a
694 mode with less than full resolution is used. Note that the current
695 video expansion status cannot be determined through this feature.
697 Note that on many models (particularly those using Radeon graphics
698 chips) the X driver configures the video card in a way which prevents
699 Fn-F7 from working. This also disables the video output switching
700 features of this driver, as it uses the same ACPI methods as
701 Fn-F7. Video switching on the console should still work.
703 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
706 ThinkLight control
707 ------------------
709 procfs: /proc/acpi/ibm/light
710 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
712 procfs notes:
714 The ThinkLight status can be read and set through the procfs interface. A
715 few models which do not make the status available will show the ThinkLight
716 status as "unknown". The available commands are:
718 echo on > /proc/acpi/ibm/light
719 echo off > /proc/acpi/ibm/light
721 sysfs notes:
723 The ThinkLight sysfs interface is documented by the LED class
724 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
725 is "tpacpi::thinklight".
727 Due to limitations in the sysfs LED class, if the status of the ThinkLight
728 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
729 It is impossible to know if the status returned through sysfs is valid.
732 Docking / undocking -- /proc/acpi/ibm/dock
733 ------------------------------------------
735 Docking and undocking (e.g. with the X4 UltraBase) requires some
736 actions to be taken by the operating system to safely make or break
737 the electrical connections with the dock.
739 The docking feature of this driver generates the following ACPI events:
741 ibm/dock GDCK 00000003 00000001 -- eject request
742 ibm/dock GDCK 00000003 00000002 -- undocked
743 ibm/dock GDCK 00000000 00000003 -- docked
745 NOTE: These events will only be generated if the laptop was docked
746 when originally booted. This is due to the current lack of support for
747 hot plugging of devices in the Linux ACPI framework. If the laptop was
748 booted while not in the dock, the following message is shown in the
749 logs:
751 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
753 In this case, no dock-related events are generated but the dock and
754 undock commands described below still work. They can be executed
755 manually or triggered by Fn key combinations (see the example acpid
756 configuration files included in the driver tarball package available
757 on the web site).
759 When the eject request button on the dock is pressed, the first event
760 above is generated. The handler for this event should issue the
761 following command:
763 echo undock > /proc/acpi/ibm/dock
765 After the LED on the dock goes off, it is safe to eject the laptop.
766 Note: if you pressed this key by mistake, go ahead and eject the
767 laptop, then dock it back in. Otherwise, the dock may not function as
768 expected.
770 When the laptop is docked, the third event above is generated. The
771 handler for this event should issue the following command to fully
772 enable the dock:
774 echo dock > /proc/acpi/ibm/dock
776 The contents of the /proc/acpi/ibm/dock file shows the current status
777 of the dock, as provided by the ACPI framework.
779 The docking support in this driver does not take care of enabling or
780 disabling any other devices you may have attached to the dock. For
781 example, a CD drive plugged into the UltraBase needs to be disabled or
782 enabled separately. See the provided example acpid configuration files
783 for how this can be accomplished.
785 There is no support yet for PCI devices that may be attached to a
786 docking station, e.g. in the ThinkPad Dock II. The driver currently
787 does not recognize, enable or disable such devices. This means that
788 the only docking stations currently supported are the X-series
789 UltraBase docks and "dumb" port replicators like the Mini Dock (the
790 latter don't need any ACPI support, actually).
793 UltraBay eject -- /proc/acpi/ibm/bay
794 ------------------------------------
796 Inserting or ejecting an UltraBay device requires some actions to be
797 taken by the operating system to safely make or break the electrical
798 connections with the device.
800 This feature generates the following ACPI events:
802 ibm/bay MSTR 00000003 00000000 -- eject request
803 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
805 NOTE: These events will only be generated if the UltraBay was present
806 when the laptop was originally booted (on the X series, the UltraBay
807 is in the dock, so it may not be present if the laptop was undocked).
808 This is due to the current lack of support for hot plugging of devices
809 in the Linux ACPI framework. If the laptop was booted without the
810 UltraBay, the following message is shown in the logs:
812 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
814 In this case, no bay-related events are generated but the eject
815 command described below still works. It can be executed manually or
816 triggered by a hot key combination.
818 Sliding the eject lever generates the first event shown above. The
819 handler for this event should take whatever actions are necessary to
820 shut down the device in the UltraBay (e.g. call idectl), then issue
821 the following command:
823 echo eject > /proc/acpi/ibm/bay
825 After the LED on the UltraBay goes off, it is safe to pull out the
826 device.
828 When the eject lever is inserted, the second event above is
829 generated. The handler for this event should take whatever actions are
830 necessary to enable the UltraBay device (e.g. call idectl).
832 The contents of the /proc/acpi/ibm/bay file shows the current status
833 of the UltraBay, as provided by the ACPI framework.
835 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
836 this feature, you need to supply the experimental=1 parameter when
837 loading the module):
839 These models do not have a button near the UltraBay device to request
840 a hot eject but rather require the laptop to be put to sleep
841 (suspend-to-ram) before the bay device is ejected or inserted).
842 The sequence of steps to eject the device is as follows:
844 echo eject > /proc/acpi/ibm/bay
845 put the ThinkPad to sleep
846 remove the drive
847 resume from sleep
848 cat /proc/acpi/ibm/bay should show that the drive was removed
850 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
851 supported. Use "eject2" instead of "eject" for the second bay.
853 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
854 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
857 CMOS/UCMS control
858 -----------------
860 procfs: /proc/acpi/ibm/cmos
861 sysfs device attribute: cmos_command
863 This feature is mostly used internally by the ACPI firmware to keep the legacy
864 CMOS NVRAM bits in sync with the current machine state, and to record this
865 state so that the ThinkPad will retain such settings across reboots.
867 Some of these commands actually perform actions in some ThinkPad models, but
868 this is expected to disappear more and more in newer models. As an example, in
869 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
870 real, but commands 0 to 2 don't control the mixer anymore (they have been
871 phased out) and just update the NVRAM.
873 The range of valid cmos command numbers is 0 to 21, but not all have an
874 effect and the behavior varies from model to model. Here is the behavior
875 on the X40 (tpb is the ThinkPad Buttons utility):
877 0 - Related to "Volume down" key press
878 1 - Related to "Volume up" key press
879 2 - Related to "Mute on" key press
880 3 - Related to "Access IBM" key press
881 4 - Related to "LCD brightness up" key press
882 5 - Related to "LCD brightness down" key press
883 11 - Related to "toggle screen expansion" key press/function
884 12 - Related to "ThinkLight on"
885 13 - Related to "ThinkLight off"
886 14 - Related to "ThinkLight" key press (toggle ThinkLight)
888 The cmos command interface is prone to firmware split-brain problems, as
889 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
890 exported just as a debug tool.
893 LED control
894 -----------
896 procfs: /proc/acpi/ibm/led
897 sysfs attributes: as per LED class, see below for names
899 Some of the LED indicators can be controlled through this feature. On
900 some older ThinkPad models, it is possible to query the status of the
901 LED indicators as well. Newer ThinkPads cannot query the real status
902 of the LED indicators.
904 Because misuse of the LEDs could induce an unaware user to perform
905 dangerous actions (like undocking or ejecting a bay device while the
906 buses are still active), or mask an important alarm (such as a nearly
907 empty battery, or a broken battery), access to most LEDs is
908 restricted.
910 Unrestricted access to all LEDs requires that thinkpad-acpi be
911 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
912 Distributions must never enable this option. Individual users that
913 are aware of the consequences are welcome to enabling it.
915 procfs notes:
917 The available commands are:
919 echo '<LED number> on' >/proc/acpi/ibm/led
920 echo '<LED number> off' >/proc/acpi/ibm/led
921 echo '<LED number> blink' >/proc/acpi/ibm/led
923 The <LED number> range is 0 to 15. The set of LEDs that can be
924 controlled varies from model to model. Here is the common ThinkPad
925 mapping:
927 0 - power
928 1 - battery (orange)
929 2 - battery (green)
930 3 - UltraBase/dock
931 4 - UltraBay
932 5 - UltraBase battery slot
933 6 - (unknown)
934 7 - standby
935 8 - dock status 1
936 9 - dock status 2
937 10, 11 - (unknown)
938 12 - thinkvantage
939 13, 14, 15 - (unknown)
941 All of the above can be turned on and off and can be made to blink.
943 sysfs notes:
945 The ThinkPad LED sysfs interface is described in detail by the LED class
946 documentation, in Documentation/leds-class.txt.
948 The LEDs are named (in LED ID order, from 0 to 12):
949 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
950 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
951 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
952 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
953 "tpacpi::thinkvantage".
955 Due to limitations in the sysfs LED class, if the status of the LED
956 indicators cannot be read due to an error, thinkpad-acpi will report it as
957 a brightness of zero (same as LED off).
959 If the thinkpad firmware doesn't support reading the current status,
960 trying to read the current LED brightness will just return whatever
961 brightness was last written to that attribute.
963 These LEDs can blink using hardware acceleration. To request that a
964 ThinkPad indicator LED should blink in hardware accelerated mode, use the
965 "timer" trigger, and leave the delay_on and delay_off parameters set to
966 zero (to request hardware acceleration autodetection).
968 LEDs that are known not to exist in a given ThinkPad model are not
969 made available through the sysfs interface. If you have a dock and you
970 notice there are LEDs listed for your ThinkPad that do not exist (and
971 are not in the dock), or if you notice that there are missing LEDs,
972 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
975 ACPI sounds -- /proc/acpi/ibm/beep
976 ----------------------------------
978 The BEEP method is used internally by the ACPI firmware to provide
979 audible alerts in various situations. This feature allows the same
980 sounds to be triggered manually.
982 The commands are non-negative integer numbers:
984 echo <number> >/proc/acpi/ibm/beep
986 The valid <number> range is 0 to 17. Not all numbers trigger sounds
987 and the sounds vary from model to model. Here is the behavior on the
988 X40:
990 0 - stop a sound in progress (but use 17 to stop 16)
991 2 - two beeps, pause, third beep ("low battery")
992 3 - single beep
993 4 - high, followed by low-pitched beep ("unable")
994 5 - single beep
995 6 - very high, followed by high-pitched beep ("AC/DC")
996 7 - high-pitched beep
997 9 - three short beeps
998 10 - very long beep
999 12 - low-pitched beep
1000 15 - three high-pitched beeps repeating constantly, stop with 0
1001 16 - one medium-pitched beep repeating constantly, stop with 17
1002 17 - stop 16
1005 Temperature sensors
1006 -------------------
1008 procfs: /proc/acpi/ibm/thermal
1009 sysfs device attributes: (hwmon "thinkpad") temp*_input
1011 Most ThinkPads include six or more separate temperature sensors but only
1012 expose the CPU temperature through the standard ACPI methods. This
1013 feature shows readings from up to eight different sensors on older
1014 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
1016 For example, on the X40, a typical output may be:
1017 temperatures: 42 42 45 41 36 -128 33 -128
1019 On the T43/p, a typical output may be:
1020 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
1022 The mapping of thermal sensors to physical locations varies depending on
1023 system-board model (and thus, on ThinkPad model).
1025 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
1026 tries to track down these locations for various models.
1028 Most (newer?) models seem to follow this pattern:
1030 1: CPU
1031 2: (depends on model)
1032 3: (depends on model)
1033 4: GPU
1034 5: Main battery: main sensor
1035 6: Bay battery: main sensor
1036 7: Main battery: secondary sensor
1037 8: Bay battery: secondary sensor
1038 9-15: (depends on model)
1040 For the R51 (source: Thomas Gruber):
1041 2: Mini-PCI
1042 3: Internal HDD
1044 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
1045 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
1046 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
1047 3: PCMCIA slot
1048 9: MCH (northbridge) to DRAM Bus
1049 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
1050 card, under touchpad
1051 11: Power regulator, underside of system board, below F2 key
1053 The A31 has a very atypical layout for the thermal sensors
1054 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
1055 1: CPU
1056 2: Main Battery: main sensor
1057 3: Power Converter
1058 4: Bay Battery: main sensor
1059 5: MCH (northbridge)
1060 6: PCMCIA/ambient
1061 7: Main Battery: secondary sensor
1062 8: Bay Battery: secondary sensor
1065 Procfs notes:
1066 Readings from sensors that are not available return -128.
1067 No commands can be written to this file.
1069 Sysfs notes:
1070 Sensors that are not available return the ENXIO error. This
1071 status may change at runtime, as there are hotplug thermal
1072 sensors, like those inside the batteries and docks.
1074 thinkpad-acpi thermal sensors are reported through the hwmon
1075 subsystem, and follow all of the hwmon guidelines at
1076 Documentation/hwmon.
1079 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
1080 ------------------------------------------------------------------------
1082 This feature is marked EXPERIMENTAL because the implementation
1083 directly accesses hardware registers and may not work as expected. USE
1084 WITH CAUTION! To use this feature, you need to supply the
1085 experimental=1 parameter when loading the module.
1087 This feature dumps the values of 256 embedded controller
1088 registers. Values which have changed since the last time the registers
1089 were dumped are marked with a star:
1091 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1092 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
1093 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
1094 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
1095 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1096 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
1097 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1098 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
1099 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
1100 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
1101 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
1102 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1103 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
1104 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1105 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1106 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1107 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1108 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1110 This feature can be used to determine the register holding the fan
1111 speed on some models. To do that, do the following:
1113 - make sure the battery is fully charged
1114 - make sure the fan is running
1115 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
1117 The first step makes sure various charging-related values don't
1118 vary. The second ensures that the fan-related values do vary, since
1119 the fan speed fluctuates a bit. The third will (hopefully) mark the
1120 fan register with a star:
1122 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1123 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
1124 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
1125 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
1126 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1127 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
1128 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1129 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
1130 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
1131 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
1132 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
1133 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1134 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
1135 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1136 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1137 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1138 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1139 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1141 Another set of values that varies often is the temperature
1142 readings. Since temperatures don't change vary fast, you can take
1143 several quick dumps to eliminate them.
1145 You can use a similar method to figure out the meaning of other
1146 embedded controller registers - e.g. make sure nothing else changes
1147 except the charging or discharging battery to determine which
1148 registers contain the current battery capacity, etc. If you experiment
1149 with this, do send me your results (including some complete dumps with
1150 a description of the conditions when they were taken.)
1153 LCD brightness control
1154 ----------------------
1156 procfs: /proc/acpi/ibm/brightness
1157 sysfs backlight device "thinkpad_screen"
1159 This feature allows software control of the LCD brightness on ThinkPad
1160 models which don't have a hardware brightness slider.
1162 It has some limitations: the LCD backlight cannot be actually turned
1163 on or off by this interface, it just controls the backlight brightness
1164 level.
1166 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1167 has eight brightness levels, ranging from 0 to 7. Some of the levels
1168 may not be distinct. Later Lenovo models that implement the ACPI
1169 display backlight brightness control methods have 16 levels, ranging
1170 from 0 to 15.
1172 For IBM ThinkPads, there are two interfaces to the firmware for direct
1173 brightness control, EC and UCMS (or CMOS). To select which one should be
1174 used, use the brightness_mode module parameter: brightness_mode=1 selects
1175 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1176 mode with NVRAM backing (so that brightness changes are remembered across
1177 shutdown/reboot).
1179 The driver tries to select which interface to use from a table of
1180 defaults for each ThinkPad model. If it makes a wrong choice, please
1181 report this as a bug, so that we can fix it.
1183 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1185 When display backlight brightness controls are available through the
1186 standard ACPI interface, it is best to use it instead of this direct
1187 ThinkPad-specific interface. The driver will disable its native
1188 backlight brightness control interface if it detects that the standard
1189 ACPI interface is available in the ThinkPad.
1191 The brightness_enable module parameter can be used to control whether
1192 the LCD brightness control feature will be enabled when available.
1193 brightness_enable=0 forces it to be disabled. brightness_enable=1
1194 forces it to be enabled when available, even if the standard ACPI
1195 interface is also available.
1197 Procfs notes:
1199 The available commands are:
1201 echo up >/proc/acpi/ibm/brightness
1202 echo down >/proc/acpi/ibm/brightness
1203 echo 'level <level>' >/proc/acpi/ibm/brightness
1205 Sysfs notes:
1207 The interface is implemented through the backlight sysfs class, which is
1208 poorly documented at this time.
1210 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1211 it there will be the following attributes:
1213 max_brightness:
1214 Reads the maximum brightness the hardware can be set to.
1215 The minimum is always zero.
1217 actual_brightness:
1218 Reads what brightness the screen is set to at this instant.
1220 brightness:
1221 Writes request the driver to change brightness to the
1222 given value. Reads will tell you what brightness the
1223 driver is trying to set the display to when "power" is set
1224 to zero and the display has not been dimmed by a kernel
1225 power management event.
1227 power:
1228 power management mode, where 0 is "display on", and 1 to 3
1229 will dim the display backlight to brightness level 0
1230 because thinkpad-acpi cannot really turn the backlight
1231 off. Kernel power management events can temporarily
1232 increase the current power management level, i.e. they can
1233 dim the display.
1236 WARNING:
1238 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1239 interface and the ACPI-based backlight level change interface
1240 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1241 at the same time. The two will interact in bad ways, do funny things,
1242 and maybe reduce the life of the backlight lamps by needlessly kicking
1243 its level up and down at every change.
1246 Volume control -- /proc/acpi/ibm/volume
1247 ---------------------------------------
1249 This feature allows volume control on ThinkPad models which don't have
1250 a hardware volume knob. The available commands are:
1252 echo up >/proc/acpi/ibm/volume
1253 echo down >/proc/acpi/ibm/volume
1254 echo mute >/proc/acpi/ibm/volume
1255 echo 'level <level>' >/proc/acpi/ibm/volume
1257 The <level> number range is 0 to 15 although not all of them may be
1258 distinct. The unmute the volume after the mute command, use either the
1259 up or down command (the level command will not unmute the volume).
1260 The current volume level and mute state is shown in the file.
1262 The ALSA mixer interface to this feature is still missing, but patches
1263 to add it exist. That problem should be addressed in the not so
1264 distant future.
1267 Fan control and monitoring: fan speed, fan enable/disable
1268 ---------------------------------------------------------
1270 procfs: /proc/acpi/ibm/fan
1271 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1272 pwm1_enable, fan2_input
1273 sysfs hwmon driver attributes: fan_watchdog
1275 NOTE NOTE NOTE: fan control operations are disabled by default for
1276 safety reasons. To enable them, the module parameter "fan_control=1"
1277 must be given to thinkpad-acpi.
1279 This feature attempts to show the current fan speed, control mode and
1280 other fan data that might be available. The speed is read directly
1281 from the hardware registers of the embedded controller. This is known
1282 to work on later R, T, X and Z series ThinkPads but may show a bogus
1283 value on other models.
1285 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1286 controlled separately, it shares the main fan control.
1288 Fan levels:
1290 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1291 stops the fan. The higher the level, the higher the fan speed, although
1292 adjacent levels often map to the same fan speed. 7 is the highest
1293 level, where the fan reaches the maximum recommended speed.
1295 Level "auto" means the EC changes the fan level according to some
1296 internal algorithm, usually based on readings from the thermal sensors.
1298 There is also a "full-speed" level, also known as "disengaged" level.
1299 In this level, the EC disables the speed-locked closed-loop fan control,
1300 and drives the fan as fast as it can go, which might exceed hardware
1301 limits, so use this level with caution.
1303 The fan usually ramps up or down slowly from one speed to another, and
1304 it is normal for the EC to take several seconds to react to fan
1305 commands. The full-speed level may take up to two minutes to ramp up to
1306 maximum speed, and in some ThinkPads, the tachometer readings go stale
1307 while the EC is transitioning to the full-speed level.
1309 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1310 monitoring all of the temperature sensor readings and you are ready to
1311 enable it if necessary to avoid overheating.
1313 An enabled fan in level "auto" may stop spinning if the EC decides the
1314 ThinkPad is cool enough and doesn't need the extra airflow. This is
1315 normal, and the EC will spin the fan up if the various thermal readings
1316 rise too much.
1318 On the X40, this seems to depend on the CPU and HDD temperatures.
1319 Specifically, the fan is turned on when either the CPU temperature
1320 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1321 fan is turned off when the CPU temperature drops to 49 degrees and the
1322 HDD temperature drops to 41 degrees. These thresholds cannot
1323 currently be controlled.
1325 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1326 certain conditions are met. It will override any fan programming done
1327 through thinkpad-acpi.
1329 The thinkpad-acpi kernel driver can be programmed to revert the fan
1330 level to a safe setting if userspace does not issue one of the procfs
1331 fan commands: "enable", "disable", "level" or "watchdog", or if there
1332 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1333 set to 1, manual mode) within a configurable amount of time of up to
1334 120 seconds. This functionality is called fan safety watchdog.
1336 Note that the watchdog timer stops after it enables the fan. It will be
1337 rearmed again automatically (using the same interval) when one of the
1338 above mentioned fan commands is received. The fan watchdog is,
1339 therefore, not suitable to protect against fan mode changes made through
1340 means other than the "enable", "disable", and "level" procfs fan
1341 commands, or the hwmon fan control sysfs interface.
1343 Procfs notes:
1345 The fan may be enabled or disabled with the following commands:
1347 echo enable >/proc/acpi/ibm/fan
1348 echo disable >/proc/acpi/ibm/fan
1350 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1351 will try to place it in a safe level if it is too slow or disabled.
1353 The fan level can be controlled with the command:
1355 echo 'level <level>' > /proc/acpi/ibm/fan
1357 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1358 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1359 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1360 "full-speed", and reports it as "disengaged" for backwards
1361 compatibility.
1363 On the X31 and X40 (and ONLY on those models), the fan speed can be
1364 controlled to a certain degree. Once the fan is running, it can be
1365 forced to run faster or slower with the following command:
1367 echo 'speed <speed>' > /proc/acpi/ibm/fan
1369 The sustainable range of fan speeds on the X40 appears to be from about
1370 3700 to about 7350. Values outside this range either do not have any
1371 effect or the fan speed eventually settles somewhere in that range. The
1372 fan cannot be stopped or started with this command. This functionality
1373 is incomplete, and not available through the sysfs interface.
1375 To program the safety watchdog, use the "watchdog" command.
1377 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1379 If you want to disable the watchdog, use 0 as the interval.
1381 Sysfs notes:
1383 The sysfs interface follows the hwmon subsystem guidelines for the most
1384 part, and the exception is the fan safety watchdog.
1386 Writes to any of the sysfs attributes may return the EINVAL error if
1387 that operation is not supported in a given ThinkPad or if the parameter
1388 is out-of-bounds, and EPERM if it is forbidden. They may also return
1389 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1390 to the firmware).
1392 Features not yet implemented by the driver return ENOSYS.
1394 hwmon device attribute pwm1_enable:
1395 0: PWM offline (fan is set to full-speed mode)
1396 1: Manual PWM control (use pwm1 to set fan level)
1397 2: Hardware PWM control (EC "auto" mode)
1398 3: reserved (Software PWM control, not implemented yet)
1400 Modes 0 and 2 are not supported by all ThinkPads, and the
1401 driver is not always able to detect this. If it does know a
1402 mode is unsupported, it will return -EINVAL.
1404 hwmon device attribute pwm1:
1405 Fan level, scaled from the firmware values of 0-7 to the hwmon
1406 scale of 0-255. 0 means fan stopped, 255 means highest normal
1407 speed (level 7).
1409 This attribute only commands the fan if pmw1_enable is set to 1
1410 (manual PWM control).
1412 hwmon device attribute fan1_input:
1413 Fan tachometer reading, in RPM. May go stale on certain
1414 ThinkPads while the EC transitions the PWM to offline mode,
1415 which can take up to two minutes. May return rubbish on older
1416 ThinkPads.
1418 hwmon device attribute fan2_input:
1419 Fan tachometer reading, in RPM, for the secondary fan.
1420 Available only on some ThinkPads. If the secondary fan is
1421 not installed, will always read 0.
1423 hwmon driver attribute fan_watchdog:
1424 Fan safety watchdog timer interval, in seconds. Minimum is
1425 1 second, maximum is 120 seconds. 0 disables the watchdog.
1427 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1429 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1430 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1431 would be the safest choice, though).
1434 WAN
1435 ---
1437 procfs: /proc/acpi/ibm/wan
1438 sysfs device attribute: wwan_enable (deprecated)
1439 sysfs rfkill class: switch "tpacpi_wwan_sw"
1441 This feature shows the presence and current state of the built-in
1442 Wireless WAN device.
1444 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1445 so it is kept across reboots and power-off.
1447 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1448 ThinkPad models which come with this module installed.
1450 Procfs notes:
1452 If the W-WAN card is installed, the following commands can be used:
1454 echo enable > /proc/acpi/ibm/wan
1455 echo disable > /proc/acpi/ibm/wan
1457 Sysfs notes:
1459 If the W-WAN card is installed, it can be enabled /
1460 disabled through the "wwan_enable" thinkpad-acpi device
1461 attribute, and its current status can also be queried.
1463 enable:
1464 0: disables WWAN card / WWAN card is disabled
1465 1: enables WWAN card / WWAN card is enabled.
1467 Note: this interface has been superseded by the generic rfkill
1468 class. It has been deprecated, and it will be removed in year
1469 2010.
1471 rfkill controller switch "tpacpi_wwan_sw": refer to
1472 Documentation/rfkill.txt for details.
1475 EXPERIMENTAL: UWB
1476 -----------------
1478 This feature is marked EXPERIMENTAL because it has not been extensively
1479 tested and validated in various ThinkPad models yet. The feature may not
1480 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1481 the experimental=1 parameter when loading the module.
1483 sysfs rfkill class: switch "tpacpi_uwb_sw"
1485 This feature exports an rfkill controller for the UWB device, if one is
1486 present and enabled in the BIOS.
1488 Sysfs notes:
1490 rfkill controller switch "tpacpi_uwb_sw": refer to
1491 Documentation/rfkill.txt for details.
1494 Multiple Commands, Module Parameters
1495 ------------------------------------
1497 Multiple commands can be written to the proc files in one shot by
1498 separating them with commas, for example:
1500 echo enable,0xffff > /proc/acpi/ibm/hotkey
1501 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1503 Commands can also be specified when loading the thinkpad-acpi module,
1504 for example:
1506 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1509 Enabling debugging output
1510 -------------------------
1512 The module takes a debug parameter which can be used to selectively
1513 enable various classes of debugging output, for example:
1515 modprobe thinkpad_acpi debug=0xffff
1517 will enable all debugging output classes. It takes a bitmask, so
1518 to enable more than one output class, just add their values.
1520 Debug bitmask Description
1521 0x8000 Disclose PID of userspace programs
1522 accessing some functions of the driver
1523 0x0001 Initialization and probing
1524 0x0002 Removal
1525 0x0004 RF Transmitter control (RFKILL)
1526 (bluetooth, WWAN, UWB...)
1527 0x0008 HKEY event interface, hotkeys
1528 0x0010 Fan control
1529 0x0020 Backlight brightness
1531 There is also a kernel build option to enable more debugging
1532 information, which may be necessary to debug driver problems.
1534 The level of debugging information output by the driver can be changed
1535 at runtime through sysfs, using the driver attribute debug_level. The
1536 attribute takes the same bitmask as the debug module parameter above.
1539 Force loading of module
1540 -----------------------
1542 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1543 the module parameter force_load=1. Regardless of whether this works or
1544 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1547 Sysfs interface changelog:
1549 0x000100: Initial sysfs support, as a single platform driver and
1550 device.
1551 0x000200: Hot key support for 32 hot keys, and radio slider switch
1552 support.
1553 0x010000: Hot keys are now handled by default over the input
1554 layer, the radio switch generates input event EV_RADIO,
1555 and the driver enables hot key handling by default in
1556 the firmware.
1558 0x020000: ABI fix: added a separate hwmon platform device and
1559 driver, which must be located by name (thinkpad)
1560 and the hwmon class for libsensors4 (lm-sensors 3)
1561 compatibility. Moved all hwmon attributes to this
1562 new platform device.
1564 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1565 support. If you must, use it to know you should not
1566 start a userspace NVRAM poller (allows to detect when
1567 NVRAM is compiled out by the user because it is
1568 unneeded/undesired in the first place).
1569 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1570 and proper hotkey_mask semantics (version 8 of the
1571 NVRAM polling patch). Some development snapshots of
1572 0.18 had an earlier version that did strange things
1573 to hotkey_mask.
1575 0x020200: Add poll()/select() support to the following attributes:
1576 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1578 0x020300: hotkey enable/disable support removed, attributes
1579 hotkey_bios_enabled and hotkey_enable deprecated and
1580 marked for removal.
1582 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1583 to not exist in a given model are not registered with
1584 the LED sysfs class anymore.