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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 - CMOS/UCMS control
40 - LED control
41 - ACPI sounds
42 - temperature sensors
43 - Experimental: embedded controller register dump
44 - LCD brightness control
45 - Volume control
46 - Fan control and monitoring: fan speed, fan enable/disable
47 - WAN enable and disable
48 - UWB enable and disable
50 A compatibility table by model and feature is maintained on the web
51 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
52 reports, especially if they add to or correct the compatibility table.
53 Please include the following information in your report:
55 - ThinkPad model name
56 - a copy of your ACPI tables, using the "acpidump" utility
57 - a copy of the output of dmidecode, with serial numbers
58 and UUIDs masked off
59 - which driver features work and which don't
60 - the observed behavior of non-working features
62 Any other comments or patches are also more than welcome.
65 Installation
66 ------------
68 If you are compiling this driver as included in the Linux kernel
69 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
70 It is located on the menu path: "Device Drivers" -> "X86 Platform
71 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".
74 Features
75 --------
77 The driver exports two different interfaces to userspace, which can be
78 used to access the features it provides. One is a legacy procfs-based
79 interface, which will be removed at some time in the future. The other
80 is a new sysfs-based interface which is not complete yet.
82 The procfs interface creates the /proc/acpi/ibm directory. There is a
83 file under that directory for each feature it supports. The procfs
84 interface is mostly frozen, and will change very little if at all: it
85 will not be extended to add any new functionality in the driver, instead
86 all new functionality will be implemented on the sysfs interface.
88 The sysfs interface tries to blend in the generic Linux sysfs subsystems
89 and classes as much as possible. Since some of these subsystems are not
90 yet ready or stabilized, it is expected that this interface will change,
91 and any and all userspace programs must deal with it.
94 Notes about the sysfs interface:
96 Unlike what was done with the procfs interface, correctness when talking
97 to the sysfs interfaces will be enforced, as will correctness in the
98 thinkpad-acpi's implementation of sysfs interfaces.
100 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
101 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
102 maximum correctness, even if that means changing an interface in
103 non-compatible ways. As these interfaces mature both in the kernel and
104 in thinkpad-acpi, such changes should become quite rare.
106 Applications interfacing to the thinkpad-acpi sysfs interfaces must
107 follow all sysfs guidelines and correctly process all errors (the sysfs
108 interface makes extensive use of errors). File descriptors and open /
109 close operations to the sysfs inodes must also be properly implemented.
111 The version of thinkpad-acpi's sysfs interface is exported by the driver
112 as a driver attribute (see below).
114 Sysfs driver attributes are on the driver's sysfs attribute space,
115 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
116 /sys/bus/platform/drivers/thinkpad_hwmon/
118 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
119 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
121 Sysfs device attributes for the sensors and fan are on the
122 thinkpad_hwmon device's sysfs attribute space, but you should locate it
123 looking for a hwmon device with the name attribute of "thinkpad", or
124 better yet, through libsensors.
127 Driver version
128 --------------
130 procfs: /proc/acpi/ibm/driver
131 sysfs driver attribute: version
133 The driver name and version. No commands can be written to this file.
136 Sysfs interface version
137 -----------------------
139 sysfs driver attribute: interface_version
141 Version of the thinkpad-acpi sysfs interface, as an unsigned long
142 (output in hex format: 0xAAAABBCC), where:
143 AAAA - major revision
144 BB - minor revision
145 CC - bugfix revision
147 The sysfs interface version changelog for the driver can be found at the
148 end of this document. Changes to the sysfs interface done by the kernel
149 subsystems are not documented here, nor are they tracked by this
150 attribute.
152 Changes to the thinkpad-acpi sysfs interface are only considered
153 non-experimental when they are submitted to Linux mainline, at which
154 point the changes in this interface are documented and interface_version
155 may be updated. If you are using any thinkpad-acpi features not yet
156 sent to mainline for merging, you do so on your own risk: these features
157 may disappear, or be implemented in a different and incompatible way by
158 the time they are merged in Linux mainline.
160 Changes that are backwards-compatible by nature (e.g. the addition of
161 attributes that do not change the way the other attributes work) do not
162 always warrant an update of interface_version. Therefore, one must
163 expect that an attribute might not be there, and deal with it properly
164 (an attribute not being there *is* a valid way to make it clear that a
165 feature is not available in sysfs).
168 Hot keys
169 --------
171 procfs: /proc/acpi/ibm/hotkey
172 sysfs device attribute: hotkey_*
174 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
175 some important events and also keyboard hot key presses to the operating
176 system. Enabling the hotkey functionality of thinkpad-acpi signals the
177 firmware that such a driver is present, and modifies how the ThinkPad
178 firmware will behave in many situations.
180 The driver enables the HKEY ("hot key") event reporting automatically
181 when loaded, and disables it when it is removed.
183 The driver will report HKEY events in the following format:
185 ibm/hotkey HKEY 00000080 0000xxxx
187 Some of these events refer to hot key presses, but not all of them.
189 The driver will generate events over the input layer for hot keys and
190 radio switches, and over the ACPI netlink layer for other events. The
191 input layer support accepts the standard IOCTLs to remap the keycodes
192 assigned to each hot key.
194 The hot key bit mask allows some control over which hot keys generate
195 events. If a key is "masked" (bit set to 0 in the mask), the firmware
196 will handle it. If it is "unmasked", it signals the firmware that
197 thinkpad-acpi would prefer to handle it, if the firmware would be so
198 kind to allow it (and it often doesn't!).
200 Not all bits in the mask can be modified. Not all bits that can be
201 modified do anything. Not all hot keys can be individually controlled
202 by the mask. Some models do not support the mask at all, and in those
203 models, hot keys cannot be controlled individually. The behaviour of
204 the mask is, therefore, highly dependent on the ThinkPad model.
206 Note that unmasking some keys prevents their default behavior. For
207 example, if Fn+F5 is unmasked, that key will no longer enable/disable
208 Bluetooth by itself.
210 Note also that not all Fn key combinations are supported through ACPI.
211 For example, on the X40, the brightness, volume and "Access IBM" buttons
212 do not generate ACPI events even with this driver. They *can* be used
213 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
215 procfs notes:
217 The following commands can be written to the /proc/acpi/ibm/hotkey file:
219 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
220 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
221 ... any other 8-hex-digit mask ...
222 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
224 The following commands have been deprecated and will cause the kernel
225 to log a warning:
227 echo enable > /proc/acpi/ibm/hotkey -- does nothing
228 echo disable > /proc/acpi/ibm/hotkey -- returns an error
230 The procfs interface does not support NVRAM polling control. So as to
231 maintain maximum bug-to-bug compatibility, it does not report any masks,
232 nor does it allow one to manipulate the hot key mask when the firmware
233 does not support masks at all, even if NVRAM polling is in use.
235 sysfs notes:
237 hotkey_bios_enabled:
238 DEPRECATED, WILL BE REMOVED SOON.
240 Returns 0.
242 hotkey_bios_mask:
243 Returns the hot keys mask when thinkpad-acpi was loaded.
244 Upon module unload, the hot keys mask will be restored
245 to this value.
247 hotkey_enable:
248 DEPRECATED, WILL BE REMOVED SOON.
250 0: returns -EPERM
251 1: does nothing
253 hotkey_mask:
254 bit mask to enable driver-handling (and depending on
255 the firmware, ACPI event generation) for each hot key
256 (see above). Returns the current status of the hot keys
257 mask, and allows one to modify it.
259 Note: when NVRAM polling is active, the firmware mask
260 will be different from the value returned by
261 hotkey_mask. The driver will retain enabled bits for
262 hotkeys that are under NVRAM polling even if the
263 firmware refuses them, and will not set these bits on
264 the firmware hot key mask.
266 hotkey_all_mask:
267 bit mask that should enable event reporting for all
268 supported hot keys, when echoed to hotkey_mask above.
269 Unless you know which events need to be handled
270 passively (because the firmware *will* handle them
271 anyway), do *not* use hotkey_all_mask. Use
272 hotkey_recommended_mask, instead. You have been warned.
274 hotkey_recommended_mask:
275 bit mask that should enable event reporting for all
276 supported hot keys, except those which are always
277 handled by the firmware anyway. Echo it to
278 hotkey_mask above, to use.
280 hotkey_source_mask:
281 bit mask that selects which hot keys will the driver
282 poll the NVRAM for. This is auto-detected by the driver
283 based on the capabilities reported by the ACPI firmware,
284 but it can be overridden at runtime.
286 Hot keys whose bits are set in both hotkey_source_mask
287 and also on hotkey_mask are polled for in NVRAM. Only a
288 few hot keys are available through CMOS NVRAM polling.
290 Warning: when in NVRAM mode, the volume up/down/mute
291 keys are synthesized according to changes in the mixer,
292 so you have to use volume up or volume down to unmute,
293 as per the ThinkPad volume mixer user interface. When
294 in ACPI event mode, volume up/down/mute are reported as
295 separate events, but this behaviour may be corrected in
296 future releases of this driver, in which case the
297 ThinkPad volume mixer user interface semantics will be
298 enforced.
300 hotkey_poll_freq:
301 frequency in Hz for hot key polling. It must be between
302 0 and 25 Hz. Polling is only carried out when strictly
303 needed.
305 Setting hotkey_poll_freq to zero disables polling, and
306 will cause hot key presses that require NVRAM polling
307 to never be reported.
309 Setting hotkey_poll_freq too low will cause repeated
310 pressings of the same hot key to be misreported as a
311 single key press, or to not even be detected at all.
312 The recommended polling frequency is 10Hz.
314 hotkey_radio_sw:
315 If the ThinkPad has a hardware radio switch, this
316 attribute will read 0 if the switch is in the "radios
317 disabled" position, and 1 if the switch is in the
318 "radios enabled" position.
320 This attribute has poll()/select() support.
322 hotkey_tablet_mode:
323 If the ThinkPad has tablet capabilities, this attribute
324 will read 0 if the ThinkPad is in normal mode, and
325 1 if the ThinkPad is in tablet mode.
327 This attribute has poll()/select() support.
329 hotkey_report_mode:
330 Returns the state of the procfs ACPI event report mode
331 filter for hot keys. If it is set to 1 (the default),
332 all hot key presses are reported both through the input
333 layer and also as ACPI events through procfs (but not
334 through netlink). If it is set to 2, hot key presses
335 are reported only through the input layer.
337 This attribute is read-only in kernels 2.6.23 or later,
338 and read-write on earlier kernels.
340 May return -EPERM (write access locked out by module
341 parameter) or -EACCES (read-only).
343 wakeup_reason:
344 Set to 1 if the system is waking up because the user
345 requested a bay ejection. Set to 2 if the system is
346 waking up because the user requested the system to
347 undock. Set to zero for normal wake-ups or wake-ups
348 due to unknown reasons.
350 This attribute has poll()/select() support.
352 wakeup_hotunplug_complete:
353 Set to 1 if the system was waken up because of an
354 undock or bay ejection request, and that request
355 was successfully completed. At this point, it might
356 be useful to send the system back to sleep, at the
357 user's choice. Refer to HKEY events 0x4003 and
358 0x3003, below.
360 This attribute has poll()/select() support.
362 input layer notes:
364 A Hot key is mapped to a single input layer EV_KEY event, possibly
365 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
366 code. An EV_SYN event will always be generated to mark the end of the
367 event block.
369 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
370 used as a helper to remap keys, only. They are particularly useful when
371 remapping KEY_UNKNOWN keys.
373 The events are available in an input device, with the following id:
375 Bus: BUS_HOST
376 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
377 0x17aa (PCI_VENDOR_ID_LENOVO)
378 product: 0x5054 ("TP")
379 version: 0x4101
381 The version will have its LSB incremented if the keymap changes in a
382 backwards-compatible way. The MSB shall always be 0x41 for this input
383 device. If the MSB is not 0x41, do not use the device as described in
384 this section, as it is either something else (e.g. another input device
385 exported by a thinkpad driver, such as HDAPS) or its functionality has
386 been changed in a non-backwards compatible way.
388 Adding other event types for other functionalities shall be considered a
389 backwards-compatible change for this input device.
391 Thinkpad-acpi Hot Key event map (version 0x4101):
393 ACPI Scan
394 event code Key Notes
396 0x1001 0x00 FN+F1 -
397 0x1002 0x01 FN+F2 IBM: battery (rare)
398 Lenovo: Screen lock
400 0x1003 0x02 FN+F3 Many IBM models always report
401 this hot key, even with hot keys
402 disabled or with Fn+F3 masked
403 off
404 IBM: screen lock
405 Lenovo: battery
407 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
408 semantics, i.e. sleep-to-RAM).
409 It is always generate some kind
410 of event, either the hot key
411 event or a ACPI sleep button
412 event. The firmware may
413 refuse to generate further FN+F4
414 key presses until a S3 or S4 ACPI
415 sleep cycle is performed or some
416 time passes.
418 0x1005 0x04 FN+F5 Radio. Enables/disables
419 the internal Bluetooth hardware
420 and W-WAN card if left in control
421 of the firmware. Does not affect
422 the WLAN card.
423 Should be used to turn on/off all
424 radios (Bluetooth+W-WAN+WLAN),
425 really.
427 0x1006 0x05 FN+F6 -
429 0x1007 0x06 FN+F7 Video output cycle.
430 Do you feel lucky today?
432 0x1008 0x07 FN+F8 IBM: toggle screen expand
433 Lenovo: configure UltraNav
435 0x1009 0x08 FN+F9 -
436 .. .. ..
437 0x100B 0x0A FN+F11 -
439 0x100C 0x0B FN+F12 Sleep to disk. You are always
440 supposed to handle it yourself,
441 either through the ACPI event,
442 or through a hotkey event.
443 The firmware may refuse to
444 generate further FN+F4 key
445 press events until a S3 or S4
446 ACPI sleep cycle is performed,
447 or some time passes.
449 0x100D 0x0C FN+BACKSPACE -
450 0x100E 0x0D FN+INSERT -
451 0x100F 0x0E FN+DELETE -
453 0x1010 0x0F FN+HOME Brightness up. This key is
454 always handled by the firmware
455 in IBM ThinkPads, even when
456 unmasked. Just leave it alone.
457 For Lenovo ThinkPads with a new
458 BIOS, it has to be handled either
459 by the ACPI OSI, or by userspace.
460 0x1011 0x10 FN+END Brightness down. See brightness
461 up for details.
463 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
464 always handled by the firmware,
465 even when unmasked.
467 0x1013 0x12 FN+PGDOWN -
469 0x1014 0x13 FN+SPACE Zoom key
471 0x1015 0x14 VOLUME UP Internal mixer volume up. This
472 key is always handled by the
473 firmware, even when unmasked.
474 NOTE: Lenovo seems to be changing
475 this.
476 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
477 key is always handled by the
478 firmware, even when unmasked.
479 NOTE: Lenovo seems to be changing
480 this.
481 0x1017 0x16 MUTE Mute internal mixer. This
482 key is always handled by the
483 firmware, even when unmasked.
485 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
487 0x1019 0x18 unknown
488 .. .. ..
489 0x1020 0x1F unknown
491 The ThinkPad firmware does not allow one to differentiate when most hot
492 keys are pressed or released (either that, or we don't know how to, yet).
493 For these keys, the driver generates a set of events for a key press and
494 immediately issues the same set of events for a key release. It is
495 unknown by the driver if the ThinkPad firmware triggered these events on
496 hot key press or release, but the firmware will do it for either one, not
497 both.
499 If a key is mapped to KEY_RESERVED, it generates no input events at all.
500 If a key is mapped to KEY_UNKNOWN, it generates an input event that
501 includes an scan code. If a key is mapped to anything else, it will
502 generate input device EV_KEY events.
504 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
505 events for switches:
507 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
508 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
510 Non hot-key ACPI HKEY event map:
511 0x5001 Lid closed
512 0x5002 Lid opened
513 0x5009 Tablet swivel: switched to tablet mode
514 0x500A Tablet swivel: switched to normal mode
515 0x7000 Radio Switch may have changed state
517 The above events are not propagated by the driver, except for legacy
518 compatibility purposes when hotkey_report_mode is set to 1.
520 0x2304 System is waking up from suspend to undock
521 0x2305 System is waking up from suspend to eject bay
522 0x2404 System is waking up from hibernation to undock
523 0x2405 System is waking up from hibernation to eject bay
525 The above events are never propagated by the driver.
527 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
528 0x4003 Undocked (see 0x2x04), can sleep again
529 0x500B Tablet pen inserted into its storage bay
530 0x500C Tablet pen removed from its storage bay
531 0x5010 Brightness level changed (newer Lenovo BIOSes)
533 The above events are propagated by the driver.
535 Compatibility notes:
537 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
538 supported the input layer, and sent events over the procfs ACPI event
539 interface.
541 To avoid sending duplicate events over the input layer and the ACPI
542 event interface, thinkpad-acpi 0.16 implements a module parameter
543 (hotkey_report_mode), and also a sysfs device attribute with the same
544 name.
546 Make no mistake here: userspace is expected to switch to using the input
547 layer interface of thinkpad-acpi, together with the ACPI netlink event
548 interface in kernels 2.6.23 and later, or with the ACPI procfs event
549 interface in kernels 2.6.22 and earlier.
551 If no hotkey_report_mode module parameter is specified (or it is set to
552 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
553 and earlier, also allows one to change the hotkey_report_mode through
554 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
555 interface is available, hotkey_report_mode cannot be changed through
556 sysfs (it is read-only).
558 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
559 be changed later through sysfs (any writes will return -EPERM to signal
560 that hotkey_report_mode was locked. On 2.6.23 and later, where
561 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
563 hotkey_report_mode set to 1 makes the driver export through the procfs
564 ACPI event interface all hot key presses (which are *also* sent to the
565 input layer). This is a legacy compatibility behaviour, and it is also
566 the default mode of operation for the driver.
568 hotkey_report_mode set to 2 makes the driver filter out the hot key
569 presses from the procfs ACPI event interface, so these events will only
570 be sent through the input layer. Userspace that has been updated to use
571 the thinkpad-acpi input layer interface should set hotkey_report_mode to
572 2.
574 Hot key press events are never sent to the ACPI netlink event interface.
575 Really up-to-date userspace under kernel 2.6.23 and later is to use the
576 netlink interface and the input layer interface, and don't bother at all
577 with hotkey_report_mode.
580 Brightness hotkey notes:
582 These are the current sane choices for brightness key mapping in
583 thinkpad-acpi:
585 For IBM and Lenovo models *without* ACPI backlight control (the ones on
586 which thinkpad-acpi will autoload its backlight interface by default,
587 and on which ACPI video does not export a backlight interface):
589 1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as
590 these older firmware versions unfortunately won't respect the hotkey
591 mask for brightness keys anyway, and always reacts to them. This
592 usually work fine, unless X.org drivers are doing something to block
593 the BIOS. In that case, use (3) below. This is the default mode of
594 operation.
596 2. Enable the hotkeys, but map them to something else that is NOT
597 KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause
598 userspace to try to change the backlight level, and use that as an
599 on-screen-display hint.
601 3. IF AND ONLY IF X.org drivers find a way to block the firmware from
602 automatically changing the brightness, enable the hotkeys and map
603 them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to
604 something that calls xbacklight. thinkpad-acpi will not be able to
605 change brightness in that case either, so you should disable its
606 backlight interface.
608 For Lenovo models *with* ACPI backlight control:
610 1. Load up ACPI video and use that. ACPI video will report ACPI
611 events for brightness change keys. Do not mess with thinkpad-acpi
612 defaults in this case. thinkpad-acpi should not have anything to do
613 with backlight events in a scenario where ACPI video is loaded:
614 brightness hotkeys must be disabled, and the backlight interface is
615 to be kept disabled as well. This is the default mode of operation.
617 2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
618 and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN. Process
619 these keys on userspace somehow (e.g. by calling xbacklight).
622 Bluetooth
623 ---------
625 procfs: /proc/acpi/ibm/bluetooth
626 sysfs device attribute: bluetooth_enable (deprecated)
627 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
629 This feature shows the presence and current state of a ThinkPad
630 Bluetooth device in the internal ThinkPad CDC slot.
632 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
633 so it is kept across reboots and power-off.
635 Procfs notes:
637 If Bluetooth is installed, the following commands can be used:
639 echo enable > /proc/acpi/ibm/bluetooth
640 echo disable > /proc/acpi/ibm/bluetooth
642 Sysfs notes:
644 If the Bluetooth CDC card is installed, it can be enabled /
645 disabled through the "bluetooth_enable" thinkpad-acpi device
646 attribute, and its current status can also be queried.
648 enable:
649 0: disables Bluetooth / Bluetooth is disabled
650 1: enables Bluetooth / Bluetooth is enabled.
652 Note: this interface has been superseded by the generic rfkill
653 class. It has been deprecated, and it will be removed in year
654 2010.
656 rfkill controller switch "tpacpi_bluetooth_sw": refer to
657 Documentation/rfkill.txt for details.
660 Video output control -- /proc/acpi/ibm/video
661 --------------------------------------------
663 This feature allows control over the devices used for video output -
664 LCD, CRT or DVI (if available). The following commands are available:
666 echo lcd_enable > /proc/acpi/ibm/video
667 echo lcd_disable > /proc/acpi/ibm/video
668 echo crt_enable > /proc/acpi/ibm/video
669 echo crt_disable > /proc/acpi/ibm/video
670 echo dvi_enable > /proc/acpi/ibm/video
671 echo dvi_disable > /proc/acpi/ibm/video
672 echo auto_enable > /proc/acpi/ibm/video
673 echo auto_disable > /proc/acpi/ibm/video
674 echo expand_toggle > /proc/acpi/ibm/video
675 echo video_switch > /proc/acpi/ibm/video
677 Each video output device can be enabled or disabled individually.
678 Reading /proc/acpi/ibm/video shows the status of each device.
680 Automatic video switching can be enabled or disabled. When automatic
681 video switching is enabled, certain events (e.g. opening the lid,
682 docking or undocking) cause the video output device to change
683 automatically. While this can be useful, it also causes flickering
684 and, on the X40, video corruption. By disabling automatic switching,
685 the flickering or video corruption can be avoided.
687 The video_switch command cycles through the available video outputs
688 (it simulates the behavior of Fn-F7).
690 Video expansion can be toggled through this feature. This controls
691 whether the display is expanded to fill the entire LCD screen when a
692 mode with less than full resolution is used. Note that the current
693 video expansion status cannot be determined through this feature.
695 Note that on many models (particularly those using Radeon graphics
696 chips) the X driver configures the video card in a way which prevents
697 Fn-F7 from working. This also disables the video output switching
698 features of this driver, as it uses the same ACPI methods as
699 Fn-F7. Video switching on the console should still work.
701 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
704 ThinkLight control
705 ------------------
707 procfs: /proc/acpi/ibm/light
708 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
710 procfs notes:
712 The ThinkLight status can be read and set through the procfs interface. A
713 few models which do not make the status available will show the ThinkLight
714 status as "unknown". The available commands are:
716 echo on > /proc/acpi/ibm/light
717 echo off > /proc/acpi/ibm/light
719 sysfs notes:
721 The ThinkLight sysfs interface is documented by the LED class
722 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
723 is "tpacpi::thinklight".
725 Due to limitations in the sysfs LED class, if the status of the ThinkLight
726 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
727 It is impossible to know if the status returned through sysfs is valid.
730 CMOS/UCMS control
731 -----------------
733 procfs: /proc/acpi/ibm/cmos
734 sysfs device attribute: cmos_command
736 This feature is mostly used internally by the ACPI firmware to keep the legacy
737 CMOS NVRAM bits in sync with the current machine state, and to record this
738 state so that the ThinkPad will retain such settings across reboots.
740 Some of these commands actually perform actions in some ThinkPad models, but
741 this is expected to disappear more and more in newer models. As an example, in
742 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
743 real, but commands 0 to 2 don't control the mixer anymore (they have been
744 phased out) and just update the NVRAM.
746 The range of valid cmos command numbers is 0 to 21, but not all have an
747 effect and the behavior varies from model to model. Here is the behavior
748 on the X40 (tpb is the ThinkPad Buttons utility):
750 0 - Related to "Volume down" key press
751 1 - Related to "Volume up" key press
752 2 - Related to "Mute on" key press
753 3 - Related to "Access IBM" key press
754 4 - Related to "LCD brightness up" key press
755 5 - Related to "LCD brightness down" key press
756 11 - Related to "toggle screen expansion" key press/function
757 12 - Related to "ThinkLight on"
758 13 - Related to "ThinkLight off"
759 14 - Related to "ThinkLight" key press (toggle ThinkLight)
761 The cmos command interface is prone to firmware split-brain problems, as
762 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
763 exported just as a debug tool.
766 LED control
767 -----------
769 procfs: /proc/acpi/ibm/led
770 sysfs attributes: as per LED class, see below for names
772 Some of the LED indicators can be controlled through this feature. On
773 some older ThinkPad models, it is possible to query the status of the
774 LED indicators as well. Newer ThinkPads cannot query the real status
775 of the LED indicators.
777 Because misuse of the LEDs could induce an unaware user to perform
778 dangerous actions (like undocking or ejecting a bay device while the
779 buses are still active), or mask an important alarm (such as a nearly
780 empty battery, or a broken battery), access to most LEDs is
781 restricted.
783 Unrestricted access to all LEDs requires that thinkpad-acpi be
784 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
785 Distributions must never enable this option. Individual users that
786 are aware of the consequences are welcome to enabling it.
788 procfs notes:
790 The available commands are:
792 echo '<LED number> on' >/proc/acpi/ibm/led
793 echo '<LED number> off' >/proc/acpi/ibm/led
794 echo '<LED number> blink' >/proc/acpi/ibm/led
796 The <LED number> range is 0 to 15. The set of LEDs that can be
797 controlled varies from model to model. Here is the common ThinkPad
798 mapping:
800 0 - power
801 1 - battery (orange)
802 2 - battery (green)
803 3 - UltraBase/dock
804 4 - UltraBay
805 5 - UltraBase battery slot
806 6 - (unknown)
807 7 - standby
808 8 - dock status 1
809 9 - dock status 2
810 10, 11 - (unknown)
811 12 - thinkvantage
812 13, 14, 15 - (unknown)
814 All of the above can be turned on and off and can be made to blink.
816 sysfs notes:
818 The ThinkPad LED sysfs interface is described in detail by the LED class
819 documentation, in Documentation/leds-class.txt.
821 The LEDs are named (in LED ID order, from 0 to 12):
822 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
823 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
824 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
825 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
826 "tpacpi::thinkvantage".
828 Due to limitations in the sysfs LED class, if the status of the LED
829 indicators cannot be read due to an error, thinkpad-acpi will report it as
830 a brightness of zero (same as LED off).
832 If the thinkpad firmware doesn't support reading the current status,
833 trying to read the current LED brightness will just return whatever
834 brightness was last written to that attribute.
836 These LEDs can blink using hardware acceleration. To request that a
837 ThinkPad indicator LED should blink in hardware accelerated mode, use the
838 "timer" trigger, and leave the delay_on and delay_off parameters set to
839 zero (to request hardware acceleration autodetection).
841 LEDs that are known not to exist in a given ThinkPad model are not
842 made available through the sysfs interface. If you have a dock and you
843 notice there are LEDs listed for your ThinkPad that do not exist (and
844 are not in the dock), or if you notice that there are missing LEDs,
845 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
848 ACPI sounds -- /proc/acpi/ibm/beep
849 ----------------------------------
851 The BEEP method is used internally by the ACPI firmware to provide
852 audible alerts in various situations. This feature allows the same
853 sounds to be triggered manually.
855 The commands are non-negative integer numbers:
857 echo <number> >/proc/acpi/ibm/beep
859 The valid <number> range is 0 to 17. Not all numbers trigger sounds
860 and the sounds vary from model to model. Here is the behavior on the
861 X40:
863 0 - stop a sound in progress (but use 17 to stop 16)
864 2 - two beeps, pause, third beep ("low battery")
865 3 - single beep
866 4 - high, followed by low-pitched beep ("unable")
867 5 - single beep
868 6 - very high, followed by high-pitched beep ("AC/DC")
869 7 - high-pitched beep
870 9 - three short beeps
871 10 - very long beep
872 12 - low-pitched beep
873 15 - three high-pitched beeps repeating constantly, stop with 0
874 16 - one medium-pitched beep repeating constantly, stop with 17
875 17 - stop 16
878 Temperature sensors
879 -------------------
881 procfs: /proc/acpi/ibm/thermal
882 sysfs device attributes: (hwmon "thinkpad") temp*_input
884 Most ThinkPads include six or more separate temperature sensors but only
885 expose the CPU temperature through the standard ACPI methods. This
886 feature shows readings from up to eight different sensors on older
887 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
889 For example, on the X40, a typical output may be:
890 temperatures: 42 42 45 41 36 -128 33 -128
892 On the T43/p, a typical output may be:
893 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
895 The mapping of thermal sensors to physical locations varies depending on
896 system-board model (and thus, on ThinkPad model).
898 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
899 tries to track down these locations for various models.
901 Most (newer?) models seem to follow this pattern:
903 1: CPU
904 2: (depends on model)
905 3: (depends on model)
906 4: GPU
907 5: Main battery: main sensor
908 6: Bay battery: main sensor
909 7: Main battery: secondary sensor
910 8: Bay battery: secondary sensor
911 9-15: (depends on model)
913 For the R51 (source: Thomas Gruber):
914 2: Mini-PCI
915 3: Internal HDD
917 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
918 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
919 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
920 3: PCMCIA slot
921 9: MCH (northbridge) to DRAM Bus
922 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
923 card, under touchpad
924 11: Power regulator, underside of system board, below F2 key
926 The A31 has a very atypical layout for the thermal sensors
927 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
928 1: CPU
929 2: Main Battery: main sensor
930 3: Power Converter
931 4: Bay Battery: main sensor
932 5: MCH (northbridge)
933 6: PCMCIA/ambient
934 7: Main Battery: secondary sensor
935 8: Bay Battery: secondary sensor
938 Procfs notes:
939 Readings from sensors that are not available return -128.
940 No commands can be written to this file.
942 Sysfs notes:
943 Sensors that are not available return the ENXIO error. This
944 status may change at runtime, as there are hotplug thermal
945 sensors, like those inside the batteries and docks.
947 thinkpad-acpi thermal sensors are reported through the hwmon
948 subsystem, and follow all of the hwmon guidelines at
949 Documentation/hwmon.
952 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
953 ------------------------------------------------------------------------
955 This feature is marked EXPERIMENTAL because the implementation
956 directly accesses hardware registers and may not work as expected. USE
957 WITH CAUTION! To use this feature, you need to supply the
958 experimental=1 parameter when loading the module.
960 This feature dumps the values of 256 embedded controller
961 registers. Values which have changed since the last time the registers
962 were dumped are marked with a star:
964 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
965 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
966 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
967 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
968 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
969 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
970 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
971 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
972 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
973 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
974 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
975 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
976 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
977 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
978 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
979 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
980 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
981 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
983 This feature can be used to determine the register holding the fan
984 speed on some models. To do that, do the following:
986 - make sure the battery is fully charged
987 - make sure the fan is running
988 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
990 The first step makes sure various charging-related values don't
991 vary. The second ensures that the fan-related values do vary, since
992 the fan speed fluctuates a bit. The third will (hopefully) mark the
993 fan register with a star:
995 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
996 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
997 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
998 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
999 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1000 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
1001 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1002 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
1003 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
1004 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
1005 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
1006 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1007 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
1008 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1009 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1010 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1011 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1012 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1014 Another set of values that varies often is the temperature
1015 readings. Since temperatures don't change vary fast, you can take
1016 several quick dumps to eliminate them.
1018 You can use a similar method to figure out the meaning of other
1019 embedded controller registers - e.g. make sure nothing else changes
1020 except the charging or discharging battery to determine which
1021 registers contain the current battery capacity, etc. If you experiment
1022 with this, do send me your results (including some complete dumps with
1023 a description of the conditions when they were taken.)
1026 LCD brightness control
1027 ----------------------
1029 procfs: /proc/acpi/ibm/brightness
1030 sysfs backlight device "thinkpad_screen"
1032 This feature allows software control of the LCD brightness on ThinkPad
1033 models which don't have a hardware brightness slider.
1035 It has some limitations: the LCD backlight cannot be actually turned
1036 on or off by this interface, it just controls the backlight brightness
1037 level.
1039 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1040 has eight brightness levels, ranging from 0 to 7. Some of the levels
1041 may not be distinct. Later Lenovo models that implement the ACPI
1042 display backlight brightness control methods have 16 levels, ranging
1043 from 0 to 15.
1045 For IBM ThinkPads, there are two interfaces to the firmware for direct
1046 brightness control, EC and UCMS (or CMOS). To select which one should be
1047 used, use the brightness_mode module parameter: brightness_mode=1 selects
1048 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1049 mode with NVRAM backing (so that brightness changes are remembered across
1050 shutdown/reboot).
1052 The driver tries to select which interface to use from a table of
1053 defaults for each ThinkPad model. If it makes a wrong choice, please
1054 report this as a bug, so that we can fix it.
1056 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1058 When display backlight brightness controls are available through the
1059 standard ACPI interface, it is best to use it instead of this direct
1060 ThinkPad-specific interface. The driver will disable its native
1061 backlight brightness control interface if it detects that the standard
1062 ACPI interface is available in the ThinkPad.
1064 The brightness_enable module parameter can be used to control whether
1065 the LCD brightness control feature will be enabled when available.
1066 brightness_enable=0 forces it to be disabled. brightness_enable=1
1067 forces it to be enabled when available, even if the standard ACPI
1068 interface is also available.
1070 Procfs notes:
1072 The available commands are:
1074 echo up >/proc/acpi/ibm/brightness
1075 echo down >/proc/acpi/ibm/brightness
1076 echo 'level <level>' >/proc/acpi/ibm/brightness
1078 Sysfs notes:
1080 The interface is implemented through the backlight sysfs class, which is
1081 poorly documented at this time.
1083 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1084 it there will be the following attributes:
1086 max_brightness:
1087 Reads the maximum brightness the hardware can be set to.
1088 The minimum is always zero.
1090 actual_brightness:
1091 Reads what brightness the screen is set to at this instant.
1093 brightness:
1094 Writes request the driver to change brightness to the
1095 given value. Reads will tell you what brightness the
1096 driver is trying to set the display to when "power" is set
1097 to zero and the display has not been dimmed by a kernel
1098 power management event.
1100 power:
1101 power management mode, where 0 is "display on", and 1 to 3
1102 will dim the display backlight to brightness level 0
1103 because thinkpad-acpi cannot really turn the backlight
1104 off. Kernel power management events can temporarily
1105 increase the current power management level, i.e. they can
1106 dim the display.
1109 WARNING:
1111 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1112 interface and the ACPI-based backlight level change interface
1113 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1114 at the same time. The two will interact in bad ways, do funny things,
1115 and maybe reduce the life of the backlight lamps by needlessly kicking
1116 its level up and down at every change.
1119 Volume control -- /proc/acpi/ibm/volume
1120 ---------------------------------------
1122 This feature allows volume control on ThinkPad models which don't have
1123 a hardware volume knob. The available commands are:
1125 echo up >/proc/acpi/ibm/volume
1126 echo down >/proc/acpi/ibm/volume
1127 echo mute >/proc/acpi/ibm/volume
1128 echo 'level <level>' >/proc/acpi/ibm/volume
1130 The <level> number range is 0 to 15 although not all of them may be
1131 distinct. The unmute the volume after the mute command, use either the
1132 up or down command (the level command will not unmute the volume).
1133 The current volume level and mute state is shown in the file.
1135 The ALSA mixer interface to this feature is still missing, but patches
1136 to add it exist. That problem should be addressed in the not so
1137 distant future.
1140 Fan control and monitoring: fan speed, fan enable/disable
1141 ---------------------------------------------------------
1143 procfs: /proc/acpi/ibm/fan
1144 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1145 pwm1_enable, fan2_input
1146 sysfs hwmon driver attributes: fan_watchdog
1148 NOTE NOTE NOTE: fan control operations are disabled by default for
1149 safety reasons. To enable them, the module parameter "fan_control=1"
1150 must be given to thinkpad-acpi.
1152 This feature attempts to show the current fan speed, control mode and
1153 other fan data that might be available. The speed is read directly
1154 from the hardware registers of the embedded controller. This is known
1155 to work on later R, T, X and Z series ThinkPads but may show a bogus
1156 value on other models.
1158 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1159 controlled separately, it shares the main fan control.
1161 Fan levels:
1163 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1164 stops the fan. The higher the level, the higher the fan speed, although
1165 adjacent levels often map to the same fan speed. 7 is the highest
1166 level, where the fan reaches the maximum recommended speed.
1168 Level "auto" means the EC changes the fan level according to some
1169 internal algorithm, usually based on readings from the thermal sensors.
1171 There is also a "full-speed" level, also known as "disengaged" level.
1172 In this level, the EC disables the speed-locked closed-loop fan control,
1173 and drives the fan as fast as it can go, which might exceed hardware
1174 limits, so use this level with caution.
1176 The fan usually ramps up or down slowly from one speed to another, and
1177 it is normal for the EC to take several seconds to react to fan
1178 commands. The full-speed level may take up to two minutes to ramp up to
1179 maximum speed, and in some ThinkPads, the tachometer readings go stale
1180 while the EC is transitioning to the full-speed level.
1182 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1183 monitoring all of the temperature sensor readings and you are ready to
1184 enable it if necessary to avoid overheating.
1186 An enabled fan in level "auto" may stop spinning if the EC decides the
1187 ThinkPad is cool enough and doesn't need the extra airflow. This is
1188 normal, and the EC will spin the fan up if the various thermal readings
1189 rise too much.
1191 On the X40, this seems to depend on the CPU and HDD temperatures.
1192 Specifically, the fan is turned on when either the CPU temperature
1193 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1194 fan is turned off when the CPU temperature drops to 49 degrees and the
1195 HDD temperature drops to 41 degrees. These thresholds cannot
1196 currently be controlled.
1198 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1199 certain conditions are met. It will override any fan programming done
1200 through thinkpad-acpi.
1202 The thinkpad-acpi kernel driver can be programmed to revert the fan
1203 level to a safe setting if userspace does not issue one of the procfs
1204 fan commands: "enable", "disable", "level" or "watchdog", or if there
1205 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1206 set to 1, manual mode) within a configurable amount of time of up to
1207 120 seconds. This functionality is called fan safety watchdog.
1209 Note that the watchdog timer stops after it enables the fan. It will be
1210 rearmed again automatically (using the same interval) when one of the
1211 above mentioned fan commands is received. The fan watchdog is,
1212 therefore, not suitable to protect against fan mode changes made through
1213 means other than the "enable", "disable", and "level" procfs fan
1214 commands, or the hwmon fan control sysfs interface.
1216 Procfs notes:
1218 The fan may be enabled or disabled with the following commands:
1220 echo enable >/proc/acpi/ibm/fan
1221 echo disable >/proc/acpi/ibm/fan
1223 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1224 will try to place it in a safe level if it is too slow or disabled.
1226 The fan level can be controlled with the command:
1228 echo 'level <level>' > /proc/acpi/ibm/fan
1230 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1231 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1232 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1233 "full-speed", and reports it as "disengaged" for backwards
1234 compatibility.
1236 On the X31 and X40 (and ONLY on those models), the fan speed can be
1237 controlled to a certain degree. Once the fan is running, it can be
1238 forced to run faster or slower with the following command:
1240 echo 'speed <speed>' > /proc/acpi/ibm/fan
1242 The sustainable range of fan speeds on the X40 appears to be from about
1243 3700 to about 7350. Values outside this range either do not have any
1244 effect or the fan speed eventually settles somewhere in that range. The
1245 fan cannot be stopped or started with this command. This functionality
1246 is incomplete, and not available through the sysfs interface.
1248 To program the safety watchdog, use the "watchdog" command.
1250 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1252 If you want to disable the watchdog, use 0 as the interval.
1254 Sysfs notes:
1256 The sysfs interface follows the hwmon subsystem guidelines for the most
1257 part, and the exception is the fan safety watchdog.
1259 Writes to any of the sysfs attributes may return the EINVAL error if
1260 that operation is not supported in a given ThinkPad or if the parameter
1261 is out-of-bounds, and EPERM if it is forbidden. They may also return
1262 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1263 to the firmware).
1265 Features not yet implemented by the driver return ENOSYS.
1267 hwmon device attribute pwm1_enable:
1268 0: PWM offline (fan is set to full-speed mode)
1269 1: Manual PWM control (use pwm1 to set fan level)
1270 2: Hardware PWM control (EC "auto" mode)
1271 3: reserved (Software PWM control, not implemented yet)
1273 Modes 0 and 2 are not supported by all ThinkPads, and the
1274 driver is not always able to detect this. If it does know a
1275 mode is unsupported, it will return -EINVAL.
1277 hwmon device attribute pwm1:
1278 Fan level, scaled from the firmware values of 0-7 to the hwmon
1279 scale of 0-255. 0 means fan stopped, 255 means highest normal
1280 speed (level 7).
1282 This attribute only commands the fan if pmw1_enable is set to 1
1283 (manual PWM control).
1285 hwmon device attribute fan1_input:
1286 Fan tachometer reading, in RPM. May go stale on certain
1287 ThinkPads while the EC transitions the PWM to offline mode,
1288 which can take up to two minutes. May return rubbish on older
1289 ThinkPads.
1291 hwmon device attribute fan2_input:
1292 Fan tachometer reading, in RPM, for the secondary fan.
1293 Available only on some ThinkPads. If the secondary fan is
1294 not installed, will always read 0.
1296 hwmon driver attribute fan_watchdog:
1297 Fan safety watchdog timer interval, in seconds. Minimum is
1298 1 second, maximum is 120 seconds. 0 disables the watchdog.
1300 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1302 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1303 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1304 would be the safest choice, though).
1307 WAN
1308 ---
1310 procfs: /proc/acpi/ibm/wan
1311 sysfs device attribute: wwan_enable (deprecated)
1312 sysfs rfkill class: switch "tpacpi_wwan_sw"
1314 This feature shows the presence and current state of the built-in
1315 Wireless WAN device.
1317 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1318 so it is kept across reboots and power-off.
1320 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1321 ThinkPad models which come with this module installed.
1323 Procfs notes:
1325 If the W-WAN card is installed, the following commands can be used:
1327 echo enable > /proc/acpi/ibm/wan
1328 echo disable > /proc/acpi/ibm/wan
1330 Sysfs notes:
1332 If the W-WAN card is installed, it can be enabled /
1333 disabled through the "wwan_enable" thinkpad-acpi device
1334 attribute, and its current status can also be queried.
1336 enable:
1337 0: disables WWAN card / WWAN card is disabled
1338 1: enables WWAN card / WWAN card is enabled.
1340 Note: this interface has been superseded by the generic rfkill
1341 class. It has been deprecated, and it will be removed in year
1342 2010.
1344 rfkill controller switch "tpacpi_wwan_sw": refer to
1345 Documentation/rfkill.txt for details.
1348 EXPERIMENTAL: UWB
1349 -----------------
1351 This feature is marked EXPERIMENTAL because it has not been extensively
1352 tested and validated in various ThinkPad models yet. The feature may not
1353 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1354 the experimental=1 parameter when loading the module.
1356 sysfs rfkill class: switch "tpacpi_uwb_sw"
1358 This feature exports an rfkill controller for the UWB device, if one is
1359 present and enabled in the BIOS.
1361 Sysfs notes:
1363 rfkill controller switch "tpacpi_uwb_sw": refer to
1364 Documentation/rfkill.txt for details.
1367 Multiple Commands, Module Parameters
1368 ------------------------------------
1370 Multiple commands can be written to the proc files in one shot by
1371 separating them with commas, for example:
1373 echo enable,0xffff > /proc/acpi/ibm/hotkey
1374 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1376 Commands can also be specified when loading the thinkpad-acpi module,
1377 for example:
1379 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1382 Enabling debugging output
1383 -------------------------
1385 The module takes a debug parameter which can be used to selectively
1386 enable various classes of debugging output, for example:
1388 modprobe thinkpad_acpi debug=0xffff
1390 will enable all debugging output classes. It takes a bitmask, so
1391 to enable more than one output class, just add their values.
1393 Debug bitmask Description
1394 0x8000 Disclose PID of userspace programs
1395 accessing some functions of the driver
1396 0x0001 Initialization and probing
1397 0x0002 Removal
1398 0x0004 RF Transmitter control (RFKILL)
1399 (bluetooth, WWAN, UWB...)
1400 0x0008 HKEY event interface, hotkeys
1401 0x0010 Fan control
1402 0x0020 Backlight brightness
1404 There is also a kernel build option to enable more debugging
1405 information, which may be necessary to debug driver problems.
1407 The level of debugging information output by the driver can be changed
1408 at runtime through sysfs, using the driver attribute debug_level. The
1409 attribute takes the same bitmask as the debug module parameter above.
1412 Force loading of module
1413 -----------------------
1415 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1416 the module parameter force_load=1. Regardless of whether this works or
1417 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1420 Sysfs interface changelog:
1422 0x000100: Initial sysfs support, as a single platform driver and
1423 device.
1424 0x000200: Hot key support for 32 hot keys, and radio slider switch
1425 support.
1426 0x010000: Hot keys are now handled by default over the input
1427 layer, the radio switch generates input event EV_RADIO,
1428 and the driver enables hot key handling by default in
1429 the firmware.
1431 0x020000: ABI fix: added a separate hwmon platform device and
1432 driver, which must be located by name (thinkpad)
1433 and the hwmon class for libsensors4 (lm-sensors 3)
1434 compatibility. Moved all hwmon attributes to this
1435 new platform device.
1437 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1438 support. If you must, use it to know you should not
1439 start a userspace NVRAM poller (allows to detect when
1440 NVRAM is compiled out by the user because it is
1441 unneeded/undesired in the first place).
1442 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1443 and proper hotkey_mask semantics (version 8 of the
1444 NVRAM polling patch). Some development snapshots of
1445 0.18 had an earlier version that did strange things
1446 to hotkey_mask.
1448 0x020200: Add poll()/select() support to the following attributes:
1449 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1451 0x020300: hotkey enable/disable support removed, attributes
1452 hotkey_bios_enabled and hotkey_enable deprecated and
1453 marked for removal.
1455 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1456 to not exist in a given model are not registered with
1457 the LED sysfs class anymore.