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1 ThinkPad ACPI Extras Driver
3 Version 0.20
4 April 09th, 2008
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.
21 The driver is named "thinkpad-acpi". In some places, like module
22 names, "thinkpad_acpi" is used because of userspace issues.
24 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
25 long due to length limitations on some Linux kernel versions.
27 Status
28 ------
30 The features currently supported are the following (see below for
31 detailed description):
33 - Fn key combinations
34 - Bluetooth enable and disable
35 - video output switching, expansion control
36 - ThinkLight on and off
37 - limited docking and undocking
38 - UltraBay eject
39 - CMOS 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 - Experimental: WAN enable and disable
49 A compatibility table by model and feature is maintained on the web
50 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
51 reports, especially if they add to or correct the compatibility table.
52 Please include the following information in your report:
54 - ThinkPad model name
55 - a copy of your DSDT, from /proc/acpi/dsdt
56 - a copy of the output of dmidecode, with serial numbers
57 and UUIDs masked off
58 - which driver features work and which don't
59 - the observed behavior of non-working features
61 Any other comments or patches are also more than welcome.
64 Installation
65 ------------
67 If you are compiling this driver as included in the Linux kernel
68 sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
69 enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
70 thinkpad-specific bay functionality.
72 Features
73 --------
75 The driver exports two different interfaces to userspace, which can be
76 used to access the features it provides. One is a legacy procfs-based
77 interface, which will be removed at some time in the distant future.
78 The other is a new sysfs-based interface which is not complete yet.
80 The procfs interface creates the /proc/acpi/ibm directory. There is a
81 file under that directory for each feature it supports. The procfs
82 interface is mostly frozen, and will change very little if at all: it
83 will not be extended to add any new functionality in the driver, instead
84 all new functionality will be implemented on the sysfs interface.
86 The sysfs interface tries to blend in the generic Linux sysfs subsystems
87 and classes as much as possible. Since some of these subsystems are not
88 yet ready or stabilized, it is expected that this interface will change,
89 and any and all userspace programs must deal with it.
92 Notes about the sysfs interface:
94 Unlike what was done with the procfs interface, correctness when talking
95 to the sysfs interfaces will be enforced, as will correctness in the
96 thinkpad-acpi's implementation of sysfs interfaces.
98 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
99 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
100 maximum correctness, even if that means changing an interface in
101 non-compatible ways. As these interfaces mature both in the kernel and
102 in thinkpad-acpi, such changes should become quite rare.
104 Applications interfacing to the thinkpad-acpi sysfs interfaces must
105 follow all sysfs guidelines and correctly process all errors (the sysfs
106 interface makes extensive use of errors). File descriptors and open /
107 close operations to the sysfs inodes must also be properly implemented.
109 The version of thinkpad-acpi's sysfs interface is exported by the driver
110 as a driver attribute (see below).
112 Sysfs driver attributes are on the driver's sysfs attribute space,
113 for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
114 /sys/bus/platform/drivers/thinkpad_hwmon/
116 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
117 space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
119 Sysfs device attributes for the sensors and fan are on the
120 thinkpad_hwmon device's sysfs attribute space, but you should locate it
121 looking for a hwmon device with the name attribute of "thinkpad".
123 Driver version
124 --------------
126 procfs: /proc/acpi/ibm/driver
127 sysfs driver attribute: version
129 The driver name and version. No commands can be written to this file.
131 Sysfs interface version
132 -----------------------
134 sysfs driver attribute: interface_version
136 Version of the thinkpad-acpi sysfs interface, as an unsigned long
137 (output in hex format: 0xAAAABBCC), where:
138 AAAA - major revision
139 BB - minor revision
140 CC - bugfix revision
142 The sysfs interface version changelog for the driver can be found at the
143 end of this document. Changes to the sysfs interface done by the kernel
144 subsystems are not documented here, nor are they tracked by this
145 attribute.
147 Changes to the thinkpad-acpi sysfs interface are only considered
148 non-experimental when they are submitted to Linux mainline, at which
149 point the changes in this interface are documented and interface_version
150 may be updated. If you are using any thinkpad-acpi features not yet
151 sent to mainline for merging, you do so on your own risk: these features
152 may disappear, or be implemented in a different and incompatible way by
153 the time they are merged in Linux mainline.
155 Changes that are backwards-compatible by nature (e.g. the addition of
156 attributes that do not change the way the other attributes work) do not
157 always warrant an update of interface_version. Therefore, one must
158 expect that an attribute might not be there, and deal with it properly
159 (an attribute not being there *is* a valid way to make it clear that a
160 feature is not available in sysfs).
162 Hot keys
163 --------
165 procfs: /proc/acpi/ibm/hotkey
166 sysfs device attribute: hotkey_*
168 In a ThinkPad, the ACPI HKEY handler is responsible for communicating
169 some important events and also keyboard hot key presses to the operating
170 system. Enabling the hotkey functionality of thinkpad-acpi signals the
171 firmware that such a driver is present, and modifies how the ThinkPad
172 firmware will behave in many situations.
174 The driver enables the hot key feature automatically when loaded. The
175 feature can later be disabled and enabled back at runtime. The driver
176 will also restore the hot key feature to its previous state and mask
177 when it is unloaded.
179 When the hotkey feature is enabled and the hot key mask is set (see
180 below), the driver will report HKEY events in the following format:
182 ibm/hotkey HKEY 00000080 0000xxxx
184 Some of these events refer to hot key presses, but not all.
186 The driver will generate events over the input layer for hot keys and
187 radio switches, and over the ACPI netlink layer for other events. The
188 input layer support accepts the standard IOCTLs to remap the keycodes
189 assigned to each hot key.
191 The hot key bit mask allows some control over which hot keys generate
192 events. If a key is "masked" (bit set to 0 in the mask), the firmware
193 will handle it. If it is "unmasked", it signals the firmware that
194 thinkpad-acpi would prefer to handle it, if the firmware would be so
195 kind to allow it (and it often doesn't!).
197 Not all bits in the mask can be modified. Not all bits that can be
198 modified do anything. Not all hot keys can be individually controlled
199 by the mask. Some models do not support the mask at all, and in those
200 models, hot keys cannot be controlled individually. The behaviour of
201 the mask is, therefore, highly dependent on the ThinkPad model.
203 Note that unmasking some keys prevents their default behavior. For
204 example, if Fn+F5 is unmasked, that key will no longer enable/disable
205 Bluetooth by itself.
207 Note also that not all Fn key combinations are supported through ACPI.
208 For example, on the X40, the brightness, volume and "Access IBM" buttons
209 do not generate ACPI events even with this driver. They *can* be used
210 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
212 procfs notes:
214 The following commands can be written to the /proc/acpi/ibm/hotkey file:
216 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
217 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
218 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
219 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
220 ... any other 8-hex-digit mask ...
221 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
223 The procfs interface does not support NVRAM polling control. So as to
224 maintain maximum bug-to-bug compatibility, it does not report any masks,
225 nor does it allow one to manipulate the hot key mask when the firmware
226 does not support masks at all, even if NVRAM polling is in use.
228 sysfs notes:
230 hotkey_bios_enabled:
231 Returns the status of the hot keys feature when
232 thinkpad-acpi was loaded. Upon module unload, the hot
233 key feature status will be restored to this value.
235 0: hot keys were disabled
236 1: hot keys were enabled (unusual)
238 hotkey_bios_mask:
239 Returns the hot keys mask when thinkpad-acpi was loaded.
240 Upon module unload, the hot keys mask will be restored
241 to this value.
243 hotkey_enable:
244 Enables/disables the hot keys feature in the ACPI
245 firmware, and reports current status of the hot keys
246 feature. Has no effect on the NVRAM hot key polling
247 functionality.
249 0: disables the hot keys feature / feature disabled
250 1: enables the hot keys feature / feature enabled
252 hotkey_mask:
253 bit mask to enable driver-handling (and depending on
254 the firmware, ACPI event generation) for each hot key
255 (see above). Returns the current status of the hot keys
256 mask, and allows one to modify it.
258 Note: when NVRAM polling is active, the firmware mask
259 will be different from the value returned by
260 hotkey_mask. The driver will retain enabled bits for
261 hotkeys that are under NVRAM polling even if the
262 firmware refuses them, and will not set these bits on
263 the firmware hot key mask.
265 hotkey_all_mask:
266 bit mask that should enable event reporting for all
267 supported hot keys, when echoed to hotkey_mask above.
268 Unless you know which events need to be handled
269 passively (because the firmware *will* handle them
270 anyway), do *not* use hotkey_all_mask. Use
271 hotkey_recommended_mask, instead. You have been warned.
273 hotkey_recommended_mask:
274 bit mask that should enable event reporting for all
275 supported hot keys, except those which are always
276 handled by the firmware anyway. Echo it to
277 hotkey_mask above, to use.
279 hotkey_source_mask:
280 bit mask that selects which hot keys will the driver
281 poll the NVRAM for. This is auto-detected by the driver
282 based on the capabilities reported by the ACPI firmware,
283 but it can be overridden at runtime.
285 Hot keys whose bits are set in both hotkey_source_mask
286 and also on hotkey_mask are polled for in NVRAM. Only a
287 few hot keys are available through CMOS NVRAM polling.
289 Warning: when in NVRAM mode, the volume up/down/mute
290 keys are synthesized according to changes in the mixer,
291 so you have to use volume up or volume down to unmute,
292 as per the ThinkPad volume mixer user interface. When
293 in ACPI event mode, volume up/down/mute are reported as
294 separate events, but this behaviour may be corrected in
295 future releases of this driver, in which case the
296 ThinkPad volume mixer user interface semantics will be
297 enforced.
299 hotkey_poll_freq:
300 frequency in Hz for hot key polling. It must be between
301 0 and 25 Hz. Polling is only carried out when strictly
302 needed.
304 Setting hotkey_poll_freq to zero disables polling, and
305 will cause hot key presses that require NVRAM polling
306 to never be reported.
308 Setting hotkey_poll_freq too low will cause repeated
309 pressings of the same hot key to be misreported as a
310 single key press, or to not even be detected at all.
311 The recommended polling frequency is 10Hz.
313 hotkey_radio_sw:
314 If the ThinkPad has a hardware radio switch, this
315 attribute will read 0 if the switch is in the "radios
316 disabled" position, and 1 if the switch is in the
317 "radios enabled" position.
319 This attribute has poll()/select() support.
321 hotkey_tablet_mode:
322 If the ThinkPad has tablet capabilities, this attribute
323 will read 0 if the ThinkPad is in normal mode, and
324 1 if the ThinkPad is in tablet mode.
326 This attribute has poll()/select() support.
328 hotkey_report_mode:
329 Returns the state of the procfs ACPI event report mode
330 filter for hot keys. If it is set to 1 (the default),
331 all hot key presses are reported both through the input
332 layer and also as ACPI events through procfs (but not
333 through netlink). If it is set to 2, hot key presses
334 are reported only through the input layer.
336 This attribute is read-only in kernels 2.6.23 or later,
337 and read-write on earlier kernels.
339 May return -EPERM (write access locked out by module
340 parameter) or -EACCES (read-only).
342 wakeup_reason:
343 Set to 1 if the system is waking up because the user
344 requested a bay ejection. Set to 2 if the system is
345 waking up because the user requested the system to
346 undock. Set to zero for normal wake-ups or wake-ups
347 due to unknown reasons.
349 This attribute has poll()/select() support.
351 wakeup_hotunplug_complete:
352 Set to 1 if the system was waken up because of an
353 undock or bay ejection request, and that request
354 was successfully completed. At this point, it might
355 be useful to send the system back to sleep, at the
356 user's choice. Refer to HKEY events 0x4003 and
357 0x3003, below.
359 This attribute has poll()/select() support.
361 input layer notes:
363 A Hot key is mapped to a single input layer EV_KEY event, possibly
364 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
365 code. An EV_SYN event will always be generated to mark the end of the
366 event block.
368 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
369 used as a helper to remap keys, only. They are particularly useful when
370 remapping KEY_UNKNOWN keys.
372 The events are available in an input device, with the following id:
374 Bus: BUS_HOST
375 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
376 0x17aa (PCI_VENDOR_ID_LENOVO)
377 product: 0x5054 ("TP")
378 version: 0x4101
380 The version will have its LSB incremented if the keymap changes in a
381 backwards-compatible way. The MSB shall always be 0x41 for this input
382 device. If the MSB is not 0x41, do not use the device as described in
383 this section, as it is either something else (e.g. another input device
384 exported by a thinkpad driver, such as HDAPS) or its functionality has
385 been changed in a non-backwards compatible way.
387 Adding other event types for other functionalities shall be considered a
388 backwards-compatible change for this input device.
390 Thinkpad-acpi Hot Key event map (version 0x4101):
392 ACPI Scan
393 event code Key Notes
395 0x1001 0x00 FN+F1 -
396 0x1002 0x01 FN+F2 IBM: battery (rare)
397 Lenovo: Screen lock
399 0x1003 0x02 FN+F3 Many IBM models always report
400 this hot key, even with hot keys
401 disabled or with Fn+F3 masked
402 off
403 IBM: screen lock
404 Lenovo: battery
406 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
407 semantics, i.e. sleep-to-RAM).
408 It is always generate some kind
409 of event, either the hot key
410 event or a ACPI sleep button
411 event. The firmware may
412 refuse to generate further FN+F4
413 key presses until a S3 or S4 ACPI
414 sleep cycle is performed or some
415 time passes.
417 0x1005 0x04 FN+F5 Radio. Enables/disables
418 the internal Bluetooth hardware
419 and W-WAN card if left in control
420 of the firmware. Does not affect
421 the WLAN card.
422 Should be used to turn on/off all
423 radios (Bluetooth+W-WAN+WLAN),
424 really.
426 0x1006 0x05 FN+F6 -
428 0x1007 0x06 FN+F7 Video output cycle.
429 Do you feel lucky today?
431 0x1008 0x07 FN+F8 IBM: toggle screen expand
432 Lenovo: configure UltraNav
434 0x1009 0x08 FN+F9 -
435 .. .. ..
436 0x100B 0x0A FN+F11 -
438 0x100C 0x0B FN+F12 Sleep to disk. You are always
439 supposed to handle it yourself,
440 either through the ACPI event,
441 or through a hotkey event.
442 The firmware may refuse to
443 generate further FN+F4 key
444 press events until a S3 or S4
445 ACPI sleep cycle is performed,
446 or some time passes.
448 0x100D 0x0C FN+BACKSPACE -
449 0x100E 0x0D FN+INSERT -
450 0x100F 0x0E FN+DELETE -
452 0x1010 0x0F FN+HOME Brightness up. This key is
453 always handled by the firmware
454 in IBM ThinkPads, even when
455 unmasked. Just leave it alone.
456 For Lenovo ThinkPads with a new
457 BIOS, it has to be handled either
458 by the ACPI OSI, or by userspace.
459 0x1011 0x10 FN+END Brightness down. See brightness
460 up for details.
462 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
463 always handled by the firmware,
464 even when unmasked.
466 0x1013 0x12 FN+PGDOWN -
468 0x1014 0x13 FN+SPACE Zoom key
470 0x1015 0x14 VOLUME UP Internal mixer volume up. This
471 key is always handled by the
472 firmware, even when unmasked.
473 NOTE: Lenovo seems to be changing
474 this.
475 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
476 key is always handled by the
477 firmware, even when unmasked.
478 NOTE: Lenovo seems to be changing
479 this.
480 0x1017 0x16 MUTE Mute internal mixer. This
481 key is always handled by the
482 firmware, even when unmasked.
484 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
486 0x1019 0x18 unknown
487 .. .. ..
488 0x1020 0x1F unknown
490 The ThinkPad firmware does not allow one to differentiate when most hot
491 keys are pressed or released (either that, or we don't know how to, yet).
492 For these keys, the driver generates a set of events for a key press and
493 immediately issues the same set of events for a key release. It is
494 unknown by the driver if the ThinkPad firmware triggered these events on
495 hot key press or release, but the firmware will do it for either one, not
496 both.
498 If a key is mapped to KEY_RESERVED, it generates no input events at all.
499 If a key is mapped to KEY_UNKNOWN, it generates an input event that
500 includes an scan code. If a key is mapped to anything else, it will
501 generate input device EV_KEY events.
503 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
504 events for switches:
506 SW_RFKILL_ALL T60 and later hardare rfkill rocker switch
507 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
509 Non hot-key ACPI HKEY event map:
510 0x5001 Lid closed
511 0x5002 Lid opened
512 0x5009 Tablet swivel: switched to tablet mode
513 0x500A Tablet swivel: switched to normal mode
514 0x7000 Radio Switch may have changed state
516 The above events are not propagated by the driver, except for legacy
517 compatibility purposes when hotkey_report_mode is set to 1.
519 0x2304 System is waking up from suspend to undock
520 0x2305 System is waking up from suspend to eject bay
521 0x2404 System is waking up from hibernation to undock
522 0x2405 System is waking up from hibernation to eject bay
524 The above events are never propagated by the driver.
526 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
527 0x4003 Undocked (see 0x2x04), can sleep again
528 0x500B Tablet pen inserted into its storage bay
529 0x500C Tablet pen removed from its storage bay
530 0x5010 Brightness level changed (newer Lenovo BIOSes)
532 The above events are propagated by the driver.
534 Compatibility notes:
536 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
537 supported the input layer, and sent events over the procfs ACPI event
538 interface.
540 To avoid sending duplicate events over the input layer and the ACPI
541 event interface, thinkpad-acpi 0.16 implements a module parameter
542 (hotkey_report_mode), and also a sysfs device attribute with the same
543 name.
545 Make no mistake here: userspace is expected to switch to using the input
546 layer interface of thinkpad-acpi, together with the ACPI netlink event
547 interface in kernels 2.6.23 and later, or with the ACPI procfs event
548 interface in kernels 2.6.22 and earlier.
550 If no hotkey_report_mode module parameter is specified (or it is set to
551 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
552 and earlier, also allows one to change the hotkey_report_mode through
553 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
554 interface is available, hotkey_report_mode cannot be changed through
555 sysfs (it is read-only).
557 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
558 be changed later through sysfs (any writes will return -EPERM to signal
559 that hotkey_report_mode was locked. On 2.6.23 and later, where
560 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
562 hotkey_report_mode set to 1 makes the driver export through the procfs
563 ACPI event interface all hot key presses (which are *also* sent to the
564 input layer). This is a legacy compatibility behaviour, and it is also
565 the default mode of operation for the driver.
567 hotkey_report_mode set to 2 makes the driver filter out the hot key
568 presses from the procfs ACPI event interface, so these events will only
569 be sent through the input layer. Userspace that has been updated to use
570 the thinkpad-acpi input layer interface should set hotkey_report_mode to
571 2.
573 Hot key press events are never sent to the ACPI netlink event interface.
574 Really up-to-date userspace under kernel 2.6.23 and later is to use the
575 netlink interface and the input layer interface, and don't bother at all
576 with hotkey_report_mode.
579 Brightness hotkey notes:
581 These are the current sane choices for brightness key mapping in
582 thinkpad-acpi:
584 For IBM and Lenovo models *without* ACPI backlight control (the ones on
585 which thinkpad-acpi will autoload its backlight interface by default,
586 and on which ACPI video does not export a backlight interface):
588 1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as
589 these older firmware versions unfortunately won't respect the hotkey
590 mask for brightness keys anyway, and always reacts to them. This
591 usually work fine, unless X.org drivers are doing something to block
592 the BIOS. In that case, use (3) below. This is the default mode of
593 operation.
595 2. Enable the hotkeys, but map them to something else that is NOT
596 KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause
597 userspace to try to change the backlight level, and use that as an
598 on-screen-display hint.
600 3. IF AND ONLY IF X.org drivers find a way to block the firmware from
601 automatically changing the brightness, enable the hotkeys and map
602 them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to
603 something that calls xbacklight. thinkpad-acpi will not be able to
604 change brightness in that case either, so you should disable its
605 backlight interface.
607 For Lenovo models *with* ACPI backlight control:
609 1. Load up ACPI video and use that. ACPI video will report ACPI
610 events for brightness change keys. Do not mess with thinkpad-acpi
611 defaults in this case. thinkpad-acpi should not have anything to do
612 with backlight events in a scenario where ACPI video is loaded:
613 brightness hotkeys must be disabled, and the backlight interface is
614 to be kept disabled as well. This is the default mode of operation.
616 2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
617 and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN. Process
618 these keys on userspace somehow (e.g. by calling xbacklight).
620 Bluetooth
621 ---------
623 procfs: /proc/acpi/ibm/bluetooth
624 sysfs device attribute: bluetooth_enable
626 This feature shows the presence and current state of a ThinkPad
627 Bluetooth device in the internal ThinkPad CDC slot.
629 Procfs notes:
631 If Bluetooth is installed, the following commands can be used:
633 echo enable > /proc/acpi/ibm/bluetooth
634 echo disable > /proc/acpi/ibm/bluetooth
636 Sysfs notes:
638 If the Bluetooth CDC card is installed, it can be enabled /
639 disabled through the "bluetooth_enable" thinkpad-acpi device
640 attribute, and its current status can also be queried.
642 enable:
643 0: disables Bluetooth / Bluetooth is disabled
644 1: enables Bluetooth / Bluetooth is enabled.
646 Note: this interface will be probably be superseded by the
647 generic rfkill class, so it is NOT to be considered stable yet.
649 Video output control -- /proc/acpi/ibm/video
650 --------------------------------------------
652 This feature allows control over the devices used for video output -
653 LCD, CRT or DVI (if available). The following commands are available:
655 echo lcd_enable > /proc/acpi/ibm/video
656 echo lcd_disable > /proc/acpi/ibm/video
657 echo crt_enable > /proc/acpi/ibm/video
658 echo crt_disable > /proc/acpi/ibm/video
659 echo dvi_enable > /proc/acpi/ibm/video
660 echo dvi_disable > /proc/acpi/ibm/video
661 echo auto_enable > /proc/acpi/ibm/video
662 echo auto_disable > /proc/acpi/ibm/video
663 echo expand_toggle > /proc/acpi/ibm/video
664 echo video_switch > /proc/acpi/ibm/video
666 Each video output device can be enabled or disabled individually.
667 Reading /proc/acpi/ibm/video shows the status of each device.
669 Automatic video switching can be enabled or disabled. When automatic
670 video switching is enabled, certain events (e.g. opening the lid,
671 docking or undocking) cause the video output device to change
672 automatically. While this can be useful, it also causes flickering
673 and, on the X40, video corruption. By disabling automatic switching,
674 the flickering or video corruption can be avoided.
676 The video_switch command cycles through the available video outputs
677 (it simulates the behavior of Fn-F7).
679 Video expansion can be toggled through this feature. This controls
680 whether the display is expanded to fill the entire LCD screen when a
681 mode with less than full resolution is used. Note that the current
682 video expansion status cannot be determined through this feature.
684 Note that on many models (particularly those using Radeon graphics
685 chips) the X driver configures the video card in a way which prevents
686 Fn-F7 from working. This also disables the video output switching
687 features of this driver, as it uses the same ACPI methods as
688 Fn-F7. Video switching on the console should still work.
690 UPDATE: There's now a patch for the X.org Radeon driver which
691 addresses this issue. Some people are reporting success with the patch
692 while others are still having problems. For more information:
694 https://bugs.freedesktop.org/show_bug.cgi?id=2000
696 ThinkLight control
697 ------------------
699 procfs: /proc/acpi/ibm/light
700 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
702 procfs notes:
704 The ThinkLight status can be read and set through the procfs interface. A
705 few models which do not make the status available will show the ThinkLight
706 status as "unknown". The available commands are:
708 echo on > /proc/acpi/ibm/light
709 echo off > /proc/acpi/ibm/light
711 sysfs notes:
713 The ThinkLight sysfs interface is documented by the LED class
714 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
715 is "tpacpi::thinklight".
717 Due to limitations in the sysfs LED class, if the status of the thinklight
718 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
719 It is impossible to know if the status returned through sysfs is valid.
721 Docking / undocking -- /proc/acpi/ibm/dock
722 ------------------------------------------
724 Docking and undocking (e.g. with the X4 UltraBase) requires some
725 actions to be taken by the operating system to safely make or break
726 the electrical connections with the dock.
728 The docking feature of this driver generates the following ACPI events:
730 ibm/dock GDCK 00000003 00000001 -- eject request
731 ibm/dock GDCK 00000003 00000002 -- undocked
732 ibm/dock GDCK 00000000 00000003 -- docked
734 NOTE: These events will only be generated if the laptop was docked
735 when originally booted. This is due to the current lack of support for
736 hot plugging of devices in the Linux ACPI framework. If the laptop was
737 booted while not in the dock, the following message is shown in the
738 logs:
740 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
742 In this case, no dock-related events are generated but the dock and
743 undock commands described below still work. They can be executed
744 manually or triggered by Fn key combinations (see the example acpid
745 configuration files included in the driver tarball package available
746 on the web site).
748 When the eject request button on the dock is pressed, the first event
749 above is generated. The handler for this event should issue the
750 following command:
752 echo undock > /proc/acpi/ibm/dock
754 After the LED on the dock goes off, it is safe to eject the laptop.
755 Note: if you pressed this key by mistake, go ahead and eject the
756 laptop, then dock it back in. Otherwise, the dock may not function as
757 expected.
759 When the laptop is docked, the third event above is generated. The
760 handler for this event should issue the following command to fully
761 enable the dock:
763 echo dock > /proc/acpi/ibm/dock
765 The contents of the /proc/acpi/ibm/dock file shows the current status
766 of the dock, as provided by the ACPI framework.
768 The docking support in this driver does not take care of enabling or
769 disabling any other devices you may have attached to the dock. For
770 example, a CD drive plugged into the UltraBase needs to be disabled or
771 enabled separately. See the provided example acpid configuration files
772 for how this can be accomplished.
774 There is no support yet for PCI devices that may be attached to a
775 docking station, e.g. in the ThinkPad Dock II. The driver currently
776 does not recognize, enable or disable such devices. This means that
777 the only docking stations currently supported are the X-series
778 UltraBase docks and "dumb" port replicators like the Mini Dock (the
779 latter don't need any ACPI support, actually).
781 UltraBay eject -- /proc/acpi/ibm/bay
782 ------------------------------------
784 Inserting or ejecting an UltraBay device requires some actions to be
785 taken by the operating system to safely make or break the electrical
786 connections with the device.
788 This feature generates the following ACPI events:
790 ibm/bay MSTR 00000003 00000000 -- eject request
791 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
793 NOTE: These events will only be generated if the UltraBay was present
794 when the laptop was originally booted (on the X series, the UltraBay
795 is in the dock, so it may not be present if the laptop was undocked).
796 This is due to the current lack of support for hot plugging of devices
797 in the Linux ACPI framework. If the laptop was booted without the
798 UltraBay, the following message is shown in the logs:
800 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
802 In this case, no bay-related events are generated but the eject
803 command described below still works. It can be executed manually or
804 triggered by a hot key combination.
806 Sliding the eject lever generates the first event shown above. The
807 handler for this event should take whatever actions are necessary to
808 shut down the device in the UltraBay (e.g. call idectl), then issue
809 the following command:
811 echo eject > /proc/acpi/ibm/bay
813 After the LED on the UltraBay goes off, it is safe to pull out the
814 device.
816 When the eject lever is inserted, the second event above is
817 generated. The handler for this event should take whatever actions are
818 necessary to enable the UltraBay device (e.g. call idectl).
820 The contents of the /proc/acpi/ibm/bay file shows the current status
821 of the UltraBay, as provided by the ACPI framework.
823 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
824 this feature, you need to supply the experimental=1 parameter when
825 loading the module):
827 These models do not have a button near the UltraBay device to request
828 a hot eject but rather require the laptop to be put to sleep
829 (suspend-to-ram) before the bay device is ejected or inserted).
830 The sequence of steps to eject the device is as follows:
832 echo eject > /proc/acpi/ibm/bay
833 put the ThinkPad to sleep
834 remove the drive
835 resume from sleep
836 cat /proc/acpi/ibm/bay should show that the drive was removed
838 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
839 supported. Use "eject2" instead of "eject" for the second bay.
841 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
842 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
844 CMOS control
845 ------------
847 procfs: /proc/acpi/ibm/cmos
848 sysfs device attribute: cmos_command
850 This feature is mostly used internally by the ACPI firmware to keep the legacy
851 CMOS NVRAM bits in sync with the current machine state, and to record this
852 state so that the ThinkPad will retain such settings across reboots.
854 Some of these commands actually perform actions in some ThinkPad models, but
855 this is expected to disappear more and more in newer models. As an example, in
856 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
857 real, but commands 0 to 2 don't control the mixer anymore (they have been
858 phased out) and just update the NVRAM.
860 The range of valid cmos command numbers is 0 to 21, but not all have an
861 effect and the behavior varies from model to model. Here is the behavior
862 on the X40 (tpb is the ThinkPad Buttons utility):
864 0 - Related to "Volume down" key press
865 1 - Related to "Volume up" key press
866 2 - Related to "Mute on" key press
867 3 - Related to "Access IBM" key press
868 4 - Related to "LCD brightness up" key press
869 5 - Related to "LCD brightness down" key press
870 11 - Related to "toggle screen expansion" key press/function
871 12 - Related to "ThinkLight on"
872 13 - Related to "ThinkLight off"
873 14 - Related to "ThinkLight" key press (toggle ThinkLight)
875 The cmos command interface is prone to firmware split-brain problems, as
876 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
877 exported just as a debug tool.
879 LED control
880 -----------
882 procfs: /proc/acpi/ibm/led
883 sysfs attributes: as per LED class, see below for names
885 Some of the LED indicators can be controlled through this feature. On
886 some older ThinkPad models, it is possible to query the status of the
887 LED indicators as well. Newer ThinkPads cannot query the real status
888 of the LED indicators.
890 procfs notes:
892 The available commands are:
894 echo '<LED number> on' >/proc/acpi/ibm/led
895 echo '<LED number> off' >/proc/acpi/ibm/led
896 echo '<LED number> blink' >/proc/acpi/ibm/led
898 The <LED number> range is 0 to 7. The set of LEDs that can be
899 controlled varies from model to model. Here is the common ThinkPad
900 mapping:
902 0 - power
903 1 - battery (orange)
904 2 - battery (green)
905 3 - UltraBase/dock
906 4 - UltraBay
907 5 - UltraBase battery slot
908 6 - (unknown)
909 7 - standby
911 All of the above can be turned on and off and can be made to blink.
913 sysfs notes:
915 The ThinkPad LED sysfs interface is described in detail by the LED class
916 documentation, in Documentation/leds-class.txt.
918 The leds are named (in LED ID order, from 0 to 7):
919 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
920 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
921 "tpacpi::unknown_led", "tpacpi::standby".
923 Due to limitations in the sysfs LED class, if the status of the LED
924 indicators cannot be read due to an error, thinkpad-acpi will report it as
925 a brightness of zero (same as LED off).
927 If the thinkpad firmware doesn't support reading the current status,
928 trying to read the current LED brightness will just return whatever
929 brightness was last written to that attribute.
931 These LEDs can blink using hardware acceleration. To request that a
932 ThinkPad indicator LED should blink in hardware accelerated mode, use the
933 "timer" trigger, and leave the delay_on and delay_off parameters set to
934 zero (to request hardware acceleration autodetection).
936 ACPI sounds -- /proc/acpi/ibm/beep
937 ----------------------------------
939 The BEEP method is used internally by the ACPI firmware to provide
940 audible alerts in various situations. This feature allows the same
941 sounds to be triggered manually.
943 The commands are non-negative integer numbers:
945 echo <number> >/proc/acpi/ibm/beep
947 The valid <number> range is 0 to 17. Not all numbers trigger sounds
948 and the sounds vary from model to model. Here is the behavior on the
949 X40:
951 0 - stop a sound in progress (but use 17 to stop 16)
952 2 - two beeps, pause, third beep ("low battery")
953 3 - single beep
954 4 - high, followed by low-pitched beep ("unable")
955 5 - single beep
956 6 - very high, followed by high-pitched beep ("AC/DC")
957 7 - high-pitched beep
958 9 - three short beeps
959 10 - very long beep
960 12 - low-pitched beep
961 15 - three high-pitched beeps repeating constantly, stop with 0
962 16 - one medium-pitched beep repeating constantly, stop with 17
963 17 - stop 16
965 Temperature sensors
966 -------------------
968 procfs: /proc/acpi/ibm/thermal
969 sysfs device attributes: (hwmon "thinkpad") temp*_input
971 Most ThinkPads include six or more separate temperature sensors but only
972 expose the CPU temperature through the standard ACPI methods. This
973 feature shows readings from up to eight different sensors on older
974 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
976 For example, on the X40, a typical output may be:
977 temperatures: 42 42 45 41 36 -128 33 -128
979 On the T43/p, a typical output may be:
980 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
982 The mapping of thermal sensors to physical locations varies depending on
983 system-board model (and thus, on ThinkPad model).
985 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
986 tries to track down these locations for various models.
988 Most (newer?) models seem to follow this pattern:
990 1: CPU
991 2: (depends on model)
992 3: (depends on model)
993 4: GPU
994 5: Main battery: main sensor
995 6: Bay battery: main sensor
996 7: Main battery: secondary sensor
997 8: Bay battery: secondary sensor
998 9-15: (depends on model)
1000 For the R51 (source: Thomas Gruber):
1001 2: Mini-PCI
1002 3: Internal HDD
1004 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
1005 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
1006 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
1007 3: PCMCIA slot
1008 9: MCH (northbridge) to DRAM Bus
1009 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
1010 card, under touchpad
1011 11: Power regulator, underside of system board, below F2 key
1013 The A31 has a very atypical layout for the thermal sensors
1014 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
1015 1: CPU
1016 2: Main Battery: main sensor
1017 3: Power Converter
1018 4: Bay Battery: main sensor
1019 5: MCH (northbridge)
1020 6: PCMCIA/ambient
1021 7: Main Battery: secondary sensor
1022 8: Bay Battery: secondary sensor
1025 Procfs notes:
1026 Readings from sensors that are not available return -128.
1027 No commands can be written to this file.
1029 Sysfs notes:
1030 Sensors that are not available return the ENXIO error. This
1031 status may change at runtime, as there are hotplug thermal
1032 sensors, like those inside the batteries and docks.
1034 thinkpad-acpi thermal sensors are reported through the hwmon
1035 subsystem, and follow all of the hwmon guidelines at
1036 Documentation/hwmon.
1039 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
1040 ------------------------------------------------------------------------
1042 This feature is marked EXPERIMENTAL because the implementation
1043 directly accesses hardware registers and may not work as expected. USE
1044 WITH CAUTION! To use this feature, you need to supply the
1045 experimental=1 parameter when loading the module.
1047 This feature dumps the values of 256 embedded controller
1048 registers. Values which have changed since the last time the registers
1049 were dumped are marked with a star:
1051 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1052 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
1053 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
1054 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
1055 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1056 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
1057 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1058 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
1059 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
1060 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
1061 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
1062 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1063 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
1064 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1065 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1066 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1067 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1068 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1070 This feature can be used to determine the register holding the fan
1071 speed on some models. To do that, do the following:
1073 - make sure the battery is fully charged
1074 - make sure the fan is running
1075 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
1077 The first step makes sure various charging-related values don't
1078 vary. The second ensures that the fan-related values do vary, since
1079 the fan speed fluctuates a bit. The third will (hopefully) mark the
1080 fan register with a star:
1082 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1083 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
1084 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
1085 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
1086 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1087 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
1088 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1089 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
1090 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
1091 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
1092 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
1093 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1094 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
1095 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1096 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1097 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1098 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1099 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1101 Another set of values that varies often is the temperature
1102 readings. Since temperatures don't change vary fast, you can take
1103 several quick dumps to eliminate them.
1105 You can use a similar method to figure out the meaning of other
1106 embedded controller registers - e.g. make sure nothing else changes
1107 except the charging or discharging battery to determine which
1108 registers contain the current battery capacity, etc. If you experiment
1109 with this, do send me your results (including some complete dumps with
1110 a description of the conditions when they were taken.)
1112 LCD brightness control
1113 ----------------------
1115 procfs: /proc/acpi/ibm/brightness
1116 sysfs backlight device "thinkpad_screen"
1118 This feature allows software control of the LCD brightness on ThinkPad
1119 models which don't have a hardware brightness slider.
1121 It has some limitations: the LCD backlight cannot be actually turned on or
1122 off by this interface, and in many ThinkPad models, the "dim while on
1123 battery" functionality will be enabled by the BIOS when this interface is
1124 used, and cannot be controlled.
1126 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1127 has eight brightness levels, ranging from 0 to 7. Some of the levels
1128 may not be distinct. Later Lenovo models that implement the ACPI
1129 display backlight brightness control methods have 16 levels, ranging
1130 from 0 to 15.
1132 There are two interfaces to the firmware for direct brightness control,
1133 EC and CMOS. To select which one should be used, use the
1134 brightness_mode module parameter: brightness_mode=1 selects EC mode,
1135 brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
1136 and CMOS. The driver tries to auto-detect which interface to use.
1138 When display backlight brightness controls are available through the
1139 standard ACPI interface, it is best to use it instead of this direct
1140 ThinkPad-specific interface. The driver will disable its native
1141 backlight brightness control interface if it detects that the standard
1142 ACPI interface is available in the ThinkPad.
1144 The brightness_enable module parameter can be used to control whether
1145 the LCD brightness control feature will be enabled when available.
1146 brightness_enable=0 forces it to be disabled. brightness_enable=1
1147 forces it to be enabled when available, even if the standard ACPI
1148 interface is also available.
1150 Procfs notes:
1152 The available commands are:
1154 echo up >/proc/acpi/ibm/brightness
1155 echo down >/proc/acpi/ibm/brightness
1156 echo 'level <level>' >/proc/acpi/ibm/brightness
1158 Sysfs notes:
1160 The interface is implemented through the backlight sysfs class, which is
1161 poorly documented at this time.
1163 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1164 it there will be the following attributes:
1166 max_brightness:
1167 Reads the maximum brightness the hardware can be set to.
1168 The minimum is always zero.
1170 actual_brightness:
1171 Reads what brightness the screen is set to at this instant.
1173 brightness:
1174 Writes request the driver to change brightness to the
1175 given value. Reads will tell you what brightness the
1176 driver is trying to set the display to when "power" is set
1177 to zero and the display has not been dimmed by a kernel
1178 power management event.
1180 power:
1181 power management mode, where 0 is "display on", and 1 to 3
1182 will dim the display backlight to brightness level 0
1183 because thinkpad-acpi cannot really turn the backlight
1184 off. Kernel power management events can temporarily
1185 increase the current power management level, i.e. they can
1186 dim the display.
1189 WARNING:
1191 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1192 interface and the ACPI-based backlight level change interface
1193 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1194 at the same time. The two will interact in bad ways, do funny things,
1195 and maybe reduce the life of the backlight lamps by needlessly kicking
1196 its level up and down at every change.
1198 Volume control -- /proc/acpi/ibm/volume
1199 ---------------------------------------
1201 This feature allows volume control on ThinkPad models which don't have
1202 a hardware volume knob. The available commands are:
1204 echo up >/proc/acpi/ibm/volume
1205 echo down >/proc/acpi/ibm/volume
1206 echo mute >/proc/acpi/ibm/volume
1207 echo 'level <level>' >/proc/acpi/ibm/volume
1209 The <level> number range is 0 to 15 although not all of them may be
1210 distinct. The unmute the volume after the mute command, use either the
1211 up or down command (the level command will not unmute the volume).
1212 The current volume level and mute state is shown in the file.
1214 Fan control and monitoring: fan speed, fan enable/disable
1215 ---------------------------------------------------------
1217 procfs: /proc/acpi/ibm/fan
1218 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1219 pwm1_enable
1220 sysfs hwmon driver attributes: fan_watchdog
1222 NOTE NOTE NOTE: fan control operations are disabled by default for
1223 safety reasons. To enable them, the module parameter "fan_control=1"
1224 must be given to thinkpad-acpi.
1226 This feature attempts to show the current fan speed, control mode and
1227 other fan data that might be available. The speed is read directly
1228 from the hardware registers of the embedded controller. This is known
1229 to work on later R, T, X and Z series ThinkPads but may show a bogus
1230 value on other models.
1232 Fan levels:
1234 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1235 stops the fan. The higher the level, the higher the fan speed, although
1236 adjacent levels often map to the same fan speed. 7 is the highest
1237 level, where the fan reaches the maximum recommended speed.
1239 Level "auto" means the EC changes the fan level according to some
1240 internal algorithm, usually based on readings from the thermal sensors.
1242 There is also a "full-speed" level, also known as "disengaged" level.
1243 In this level, the EC disables the speed-locked closed-loop fan control,
1244 and drives the fan as fast as it can go, which might exceed hardware
1245 limits, so use this level with caution.
1247 The fan usually ramps up or down slowly from one speed to another, and
1248 it is normal for the EC to take several seconds to react to fan
1249 commands. The full-speed level may take up to two minutes to ramp up to
1250 maximum speed, and in some ThinkPads, the tachometer readings go stale
1251 while the EC is transitioning to the full-speed level.
1253 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1254 monitoring all of the temperature sensor readings and you are ready to
1255 enable it if necessary to avoid overheating.
1257 An enabled fan in level "auto" may stop spinning if the EC decides the
1258 ThinkPad is cool enough and doesn't need the extra airflow. This is
1259 normal, and the EC will spin the fan up if the various thermal readings
1260 rise too much.
1262 On the X40, this seems to depend on the CPU and HDD temperatures.
1263 Specifically, the fan is turned on when either the CPU temperature
1264 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1265 fan is turned off when the CPU temperature drops to 49 degrees and the
1266 HDD temperature drops to 41 degrees. These thresholds cannot
1267 currently be controlled.
1269 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1270 certain conditions are met. It will override any fan programming done
1271 through thinkpad-acpi.
1273 The thinkpad-acpi kernel driver can be programmed to revert the fan
1274 level to a safe setting if userspace does not issue one of the procfs
1275 fan commands: "enable", "disable", "level" or "watchdog", or if there
1276 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1277 set to 1, manual mode) within a configurable amount of time of up to
1278 120 seconds. This functionality is called fan safety watchdog.
1280 Note that the watchdog timer stops after it enables the fan. It will be
1281 rearmed again automatically (using the same interval) when one of the
1282 above mentioned fan commands is received. The fan watchdog is,
1283 therefore, not suitable to protect against fan mode changes made through
1284 means other than the "enable", "disable", and "level" procfs fan
1285 commands, or the hwmon fan control sysfs interface.
1287 Procfs notes:
1289 The fan may be enabled or disabled with the following commands:
1291 echo enable >/proc/acpi/ibm/fan
1292 echo disable >/proc/acpi/ibm/fan
1294 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1295 will try to place it in a safe level if it is too slow or disabled.
1297 The fan level can be controlled with the command:
1299 echo 'level <level>' > /proc/acpi/ibm/fan
1301 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1302 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1303 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1304 "full-speed", and reports it as "disengaged" for backwards
1305 compatibility.
1307 On the X31 and X40 (and ONLY on those models), the fan speed can be
1308 controlled to a certain degree. Once the fan is running, it can be
1309 forced to run faster or slower with the following command:
1311 echo 'speed <speed>' > /proc/acpi/ibm/fan
1313 The sustainable range of fan speeds on the X40 appears to be from about
1314 3700 to about 7350. Values outside this range either do not have any
1315 effect or the fan speed eventually settles somewhere in that range. The
1316 fan cannot be stopped or started with this command. This functionality
1317 is incomplete, and not available through the sysfs interface.
1319 To program the safety watchdog, use the "watchdog" command.
1321 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1323 If you want to disable the watchdog, use 0 as the interval.
1325 Sysfs notes:
1327 The sysfs interface follows the hwmon subsystem guidelines for the most
1328 part, and the exception is the fan safety watchdog.
1330 Writes to any of the sysfs attributes may return the EINVAL error if
1331 that operation is not supported in a given ThinkPad or if the parameter
1332 is out-of-bounds, and EPERM if it is forbidden. They may also return
1333 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1334 to the firmware).
1336 Features not yet implemented by the driver return ENOSYS.
1338 hwmon device attribute pwm1_enable:
1339 0: PWM offline (fan is set to full-speed mode)
1340 1: Manual PWM control (use pwm1 to set fan level)
1341 2: Hardware PWM control (EC "auto" mode)
1342 3: reserved (Software PWM control, not implemented yet)
1344 Modes 0 and 2 are not supported by all ThinkPads, and the
1345 driver is not always able to detect this. If it does know a
1346 mode is unsupported, it will return -EINVAL.
1348 hwmon device attribute pwm1:
1349 Fan level, scaled from the firmware values of 0-7 to the hwmon
1350 scale of 0-255. 0 means fan stopped, 255 means highest normal
1351 speed (level 7).
1353 This attribute only commands the fan if pmw1_enable is set to 1
1354 (manual PWM control).
1356 hwmon device attribute fan1_input:
1357 Fan tachometer reading, in RPM. May go stale on certain
1358 ThinkPads while the EC transitions the PWM to offline mode,
1359 which can take up to two minutes. May return rubbish on older
1360 ThinkPads.
1362 hwmon driver attribute fan_watchdog:
1363 Fan safety watchdog timer interval, in seconds. Minimum is
1364 1 second, maximum is 120 seconds. 0 disables the watchdog.
1366 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1368 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1369 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1370 would be the safest choice, though).
1373 EXPERIMENTAL: WAN
1374 -----------------
1376 procfs: /proc/acpi/ibm/wan
1377 sysfs device attribute: wwan_enable
1379 This feature is marked EXPERIMENTAL because the implementation
1380 directly accesses hardware registers and may not work as expected. USE
1381 WITH CAUTION! To use this feature, you need to supply the
1382 experimental=1 parameter when loading the module.
1384 This feature shows the presence and current state of a W-WAN (Sierra
1385 Wireless EV-DO) device.
1387 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1388 ThinkPad models which come with this module installed.
1390 Procfs notes:
1392 If the W-WAN card is installed, the following commands can be used:
1394 echo enable > /proc/acpi/ibm/wan
1395 echo disable > /proc/acpi/ibm/wan
1397 Sysfs notes:
1399 If the W-WAN card is installed, it can be enabled /
1400 disabled through the "wwan_enable" thinkpad-acpi device
1401 attribute, and its current status can also be queried.
1403 enable:
1404 0: disables WWAN card / WWAN card is disabled
1405 1: enables WWAN card / WWAN card is enabled.
1407 Note: this interface will be probably be superseded by the
1408 generic rfkill class, so it is NOT to be considered stable yet.
1410 Multiple Commands, Module Parameters
1411 ------------------------------------
1413 Multiple commands can be written to the proc files in one shot by
1414 separating them with commas, for example:
1416 echo enable,0xffff > /proc/acpi/ibm/hotkey
1417 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1419 Commands can also be specified when loading the thinkpad-acpi module,
1420 for example:
1422 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1424 Enabling debugging output
1425 -------------------------
1427 The module takes a debug parameter which can be used to selectively
1428 enable various classes of debugging output, for example:
1430 modprobe thinkpad_acpi debug=0xffff
1432 will enable all debugging output classes. It takes a bitmask, so
1433 to enable more than one output class, just add their values.
1435 Debug bitmask Description
1436 0x0001 Initialization and probing
1437 0x0002 Removal
1439 There is also a kernel build option to enable more debugging
1440 information, which may be necessary to debug driver problems.
1442 The level of debugging information output by the driver can be changed
1443 at runtime through sysfs, using the driver attribute debug_level. The
1444 attribute takes the same bitmask as the debug module parameter above.
1446 Force loading of module
1447 -----------------------
1449 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1450 the module parameter force_load=1. Regardless of whether this works or
1451 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1454 Sysfs interface changelog:
1456 0x000100: Initial sysfs support, as a single platform driver and
1457 device.
1458 0x000200: Hot key support for 32 hot keys, and radio slider switch
1459 support.
1460 0x010000: Hot keys are now handled by default over the input
1461 layer, the radio switch generates input event EV_RADIO,
1462 and the driver enables hot key handling by default in
1463 the firmware.
1465 0x020000: ABI fix: added a separate hwmon platform device and
1466 driver, which must be located by name (thinkpad)
1467 and the hwmon class for libsensors4 (lm-sensors 3)
1468 compatibility. Moved all hwmon attributes to this
1469 new platform device.
1471 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1472 support. If you must, use it to know you should not
1473 start an userspace NVRAM poller (allows to detect when
1474 NVRAM is compiled out by the user because it is
1475 unneeded/undesired in the first place).
1476 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1477 and proper hotkey_mask semantics (version 8 of the
1478 NVRAM polling patch). Some development snapshots of
1479 0.18 had an earlier version that did strange things
1480 to hotkey_mask.
1482 0x020200: Add poll()/select() support to the following attributes:
1483 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason