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1 ThinkPad ACPI Extras Driver
3 Version 0.24
4 December 11th, 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. The behaviour
203 of the mask is, therefore, highly dependent on the ThinkPad model.
205 The driver will filter out any unmasked hotkeys, so even if the firmware
206 doesn't allow disabling an specific hotkey, the driver will not report
207 events for unmasked hotkeys.
209 Note that unmasking some keys prevents their default behavior. For
210 example, if Fn+F5 is unmasked, that key will no longer enable/disable
211 Bluetooth by itself in firmware.
213 Note also that not all Fn key combinations are supported through ACPI
214 depending on the ThinkPad model and firmware version. On those
215 ThinkPads, it is still possible to support some extra hotkeys by
216 polling the "CMOS NVRAM" at least 10 times per second. The driver
217 attempts to enables this functionality automatically when required.
219 procfs notes:
221 The following commands can be written to the /proc/acpi/ibm/hotkey file:
223 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
224 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
225 ... any other 8-hex-digit mask ...
226 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask
228 The following commands have been deprecated and will cause the kernel
229 to log a warning:
231 echo enable > /proc/acpi/ibm/hotkey -- does nothing
232 echo disable > /proc/acpi/ibm/hotkey -- returns an error
234 The procfs interface does not support NVRAM polling control. So as to
235 maintain maximum bug-to-bug compatibility, it does not report any masks,
236 nor does it allow one to manipulate the hot key mask when the firmware
237 does not support masks at all, even if NVRAM polling is in use.
239 sysfs notes:
241 hotkey_bios_enabled:
242 DEPRECATED, WILL BE REMOVED SOON.
244 Returns 0.
246 hotkey_bios_mask:
247 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE.
249 Returns the hot keys mask when thinkpad-acpi was loaded.
250 Upon module unload, the hot keys mask will be restored
251 to this value. This is always 0x80c, because those are
252 the hotkeys that were supported by ancient firmware
253 without mask support.
255 hotkey_enable:
256 DEPRECATED, WILL BE REMOVED SOON.
258 0: returns -EPERM
259 1: does nothing
261 hotkey_mask:
262 bit mask to enable reporting (and depending on
263 the firmware, ACPI event generation) for each hot key
264 (see above). Returns the current status of the hot keys
265 mask, and allows one to modify it.
267 hotkey_all_mask:
268 bit mask that should enable event reporting for all
269 supported hot keys, when echoed to hotkey_mask above.
270 Unless you know which events need to be handled
271 passively (because the firmware *will* handle them
272 anyway), do *not* use hotkey_all_mask. Use
273 hotkey_recommended_mask, instead. You have been warned.
275 hotkey_recommended_mask:
276 bit mask that should enable event reporting for all
277 supported hot keys, except those which are always
278 handled by the firmware anyway. Echo it to
279 hotkey_mask above, to use. This is the default mask
280 used by the driver.
282 hotkey_source_mask:
283 bit mask that selects which hot keys will the driver
284 poll the NVRAM for. This is auto-detected by the driver
285 based on the capabilities reported by the ACPI firmware,
286 but it can be overridden at runtime.
288 Hot keys whose bits are set in hotkey_source_mask are
289 polled for in NVRAM, and reported as hotkey events if
290 enabled in hotkey_mask. Only a few hot keys are
291 available through CMOS NVRAM polling.
293 Warning: when in NVRAM mode, the volume up/down/mute
294 keys are synthesized according to changes in the mixer,
295 so you have to use volume up or volume down to unmute,
296 as per the ThinkPad volume mixer user interface. When
297 in ACPI event mode, volume up/down/mute are reported as
298 separate events, but this behaviour may be corrected in
299 future releases of this driver, in which case the
300 ThinkPad volume mixer user interface semantics will be
301 enforced.
303 hotkey_poll_freq:
304 frequency in Hz for hot key polling. It must be between
305 0 and 25 Hz. Polling is only carried out when strictly
306 needed.
308 Setting hotkey_poll_freq to zero disables polling, and
309 will cause hot key presses that require NVRAM polling
310 to never be reported.
312 Setting hotkey_poll_freq too low will cause repeated
313 pressings of the same hot key to be misreported as a
314 single key press, or to not even be detected at all.
315 The recommended polling frequency is 10Hz.
317 hotkey_radio_sw:
318 If the ThinkPad has a hardware radio switch, this
319 attribute will read 0 if the switch is in the "radios
320 disabled" position, and 1 if the switch is in the
321 "radios enabled" position.
323 This attribute has poll()/select() support.
325 hotkey_tablet_mode:
326 If the ThinkPad has tablet capabilities, this attribute
327 will read 0 if the ThinkPad is in normal mode, and
328 1 if the ThinkPad is in tablet mode.
330 This attribute has poll()/select() support.
332 hotkey_report_mode:
333 Returns the state of the procfs ACPI event report mode
334 filter for hot keys. If it is set to 1 (the default),
335 all hot key presses are reported both through the input
336 layer and also as ACPI events through procfs (but not
337 through netlink). If it is set to 2, hot key presses
338 are reported only through the input layer.
340 This attribute is read-only in kernels 2.6.23 or later,
341 and read-write on earlier kernels.
343 May return -EPERM (write access locked out by module
344 parameter) or -EACCES (read-only).
346 wakeup_reason:
347 Set to 1 if the system is waking up because the user
348 requested a bay ejection. Set to 2 if the system is
349 waking up because the user requested the system to
350 undock. Set to zero for normal wake-ups or wake-ups
351 due to unknown reasons.
353 This attribute has poll()/select() support.
355 wakeup_hotunplug_complete:
356 Set to 1 if the system was waken up because of an
357 undock or bay ejection request, and that request
358 was successfully completed. At this point, it might
359 be useful to send the system back to sleep, at the
360 user's choice. Refer to HKEY events 0x4003 and
361 0x3003, below.
363 This attribute has poll()/select() support.
365 input layer notes:
367 A Hot key is mapped to a single input layer EV_KEY event, possibly
368 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
369 code. An EV_SYN event will always be generated to mark the end of the
370 event block.
372 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
373 used as a helper to remap keys, only. They are particularly useful when
374 remapping KEY_UNKNOWN keys.
376 The events are available in an input device, with the following id:
378 Bus: BUS_HOST
379 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
380 0x17aa (PCI_VENDOR_ID_LENOVO)
381 product: 0x5054 ("TP")
382 version: 0x4101
384 The version will have its LSB incremented if the keymap changes in a
385 backwards-compatible way. The MSB shall always be 0x41 for this input
386 device. If the MSB is not 0x41, do not use the device as described in
387 this section, as it is either something else (e.g. another input device
388 exported by a thinkpad driver, such as HDAPS) or its functionality has
389 been changed in a non-backwards compatible way.
391 Adding other event types for other functionalities shall be considered a
392 backwards-compatible change for this input device.
394 Thinkpad-acpi Hot Key event map (version 0x4101):
396 ACPI Scan
397 event code Key Notes
399 0x1001 0x00 FN+F1 -
400 0x1002 0x01 FN+F2 IBM: battery (rare)
401 Lenovo: Screen lock
403 0x1003 0x02 FN+F3 Many IBM models always report
404 this hot key, even with hot keys
405 disabled or with Fn+F3 masked
406 off
407 IBM: screen lock
408 Lenovo: battery
410 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
411 semantics, i.e. sleep-to-RAM).
412 It is always generate some kind
413 of event, either the hot key
414 event or a ACPI sleep button
415 event. The firmware may
416 refuse to generate further FN+F4
417 key presses until a S3 or S4 ACPI
418 sleep cycle is performed or some
419 time passes.
421 0x1005 0x04 FN+F5 Radio. Enables/disables
422 the internal Bluetooth hardware
423 and W-WAN card if left in control
424 of the firmware. Does not affect
425 the WLAN card.
426 Should be used to turn on/off all
427 radios (Bluetooth+W-WAN+WLAN),
428 really.
430 0x1006 0x05 FN+F6 -
432 0x1007 0x06 FN+F7 Video output cycle.
433 Do you feel lucky today?
435 0x1008 0x07 FN+F8 IBM: toggle screen expand
436 Lenovo: configure UltraNav
438 0x1009 0x08 FN+F9 -
439 .. .. ..
440 0x100B 0x0A FN+F11 -
442 0x100C 0x0B FN+F12 Sleep to disk. You are always
443 supposed to handle it yourself,
444 either through the ACPI event,
445 or through a hotkey event.
446 The firmware may refuse to
447 generate further FN+F4 key
448 press events until a S3 or S4
449 ACPI sleep cycle is performed,
450 or some time passes.
452 0x100D 0x0C FN+BACKSPACE -
453 0x100E 0x0D FN+INSERT -
454 0x100F 0x0E FN+DELETE -
456 0x1010 0x0F FN+HOME Brightness up. This key is
457 always handled by the firmware
458 in IBM ThinkPads, even when
459 unmasked. Just leave it alone.
460 For Lenovo ThinkPads with a new
461 BIOS, it has to be handled either
462 by the ACPI OSI, or by userspace.
463 The driver does the right thing,
464 never mess with this.
465 0x1011 0x10 FN+END Brightness down. See brightness
466 up for details.
468 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
469 always handled by the firmware,
470 even when unmasked.
472 0x1013 0x12 FN+PGDOWN -
474 0x1014 0x13 FN+SPACE Zoom key
476 0x1015 0x14 VOLUME UP 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 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
482 key is always handled by the
483 firmware, even when unmasked.
484 NOTE: Lenovo seems to be changing
485 this.
486 0x1017 0x16 MUTE Mute internal mixer. This
487 key is always handled by the
488 firmware, even when unmasked.
490 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
492 0x1019 0x18 unknown
493 .. .. ..
494 0x1020 0x1F unknown
496 The ThinkPad firmware does not allow one to differentiate when most hot
497 keys are pressed or released (either that, or we don't know how to, yet).
498 For these keys, the driver generates a set of events for a key press and
499 immediately issues the same set of events for a key release. It is
500 unknown by the driver if the ThinkPad firmware triggered these events on
501 hot key press or release, but the firmware will do it for either one, not
502 both.
504 If a key is mapped to KEY_RESERVED, it generates no input events at all.
505 If a key is mapped to KEY_UNKNOWN, it generates an input event that
506 includes an scan code. If a key is mapped to anything else, it will
507 generate input device EV_KEY events.
509 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
510 events for switches:
512 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
513 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
515 Non hot-key ACPI HKEY event map:
516 0x5001 Lid closed
517 0x5002 Lid opened
518 0x5009 Tablet swivel: switched to tablet mode
519 0x500A Tablet swivel: switched to normal mode
520 0x7000 Radio Switch may have changed state
522 The above events are not propagated by the driver, except for legacy
523 compatibility purposes when hotkey_report_mode is set to 1.
525 0x2304 System is waking up from suspend to undock
526 0x2305 System is waking up from suspend to eject bay
527 0x2404 System is waking up from hibernation to undock
528 0x2405 System is waking up from hibernation to eject bay
529 0x5010 Brightness level changed/control event
531 The above events are never propagated by the driver.
533 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
534 0x4003 Undocked (see 0x2x04), can sleep again
535 0x500B Tablet pen inserted into its storage bay
536 0x500C Tablet pen removed from its storage bay
538 The above events are propagated by the driver.
540 Compatibility notes:
542 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
543 supported the input layer, and sent events over the procfs ACPI event
544 interface.
546 To avoid sending duplicate events over the input layer and the ACPI
547 event interface, thinkpad-acpi 0.16 implements a module parameter
548 (hotkey_report_mode), and also a sysfs device attribute with the same
549 name.
551 Make no mistake here: userspace is expected to switch to using the input
552 layer interface of thinkpad-acpi, together with the ACPI netlink event
553 interface in kernels 2.6.23 and later, or with the ACPI procfs event
554 interface in kernels 2.6.22 and earlier.
556 If no hotkey_report_mode module parameter is specified (or it is set to
557 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
558 and earlier, also allows one to change the hotkey_report_mode through
559 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
560 interface is available, hotkey_report_mode cannot be changed through
561 sysfs (it is read-only).
563 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
564 be changed later through sysfs (any writes will return -EPERM to signal
565 that hotkey_report_mode was locked. On 2.6.23 and later, where
566 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
568 hotkey_report_mode set to 1 makes the driver export through the procfs
569 ACPI event interface all hot key presses (which are *also* sent to the
570 input layer). This is a legacy compatibility behaviour, and it is also
571 the default mode of operation for the driver.
573 hotkey_report_mode set to 2 makes the driver filter out the hot key
574 presses from the procfs ACPI event interface, so these events will only
575 be sent through the input layer. Userspace that has been updated to use
576 the thinkpad-acpi input layer interface should set hotkey_report_mode to
577 2.
579 Hot key press events are never sent to the ACPI netlink event interface.
580 Really up-to-date userspace under kernel 2.6.23 and later is to use the
581 netlink interface and the input layer interface, and don't bother at all
582 with hotkey_report_mode.
585 Brightness hotkey notes:
587 Don't mess with the brightness hotkeys in a Thinkpad. If you want
588 notifications for OSD, use the sysfs backlight class event support.
590 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
591 automatically for the cases were userspace has to do something to
592 implement brightness changes. When you override these events, you will
593 either fail to handle properly the ThinkPads that require explicit
594 action to change backlight brightness, or the ThinkPads that require
595 that no action be taken to work properly.
598 Bluetooth
599 ---------
601 procfs: /proc/acpi/ibm/bluetooth
602 sysfs device attribute: bluetooth_enable (deprecated)
603 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
605 This feature shows the presence and current state of a ThinkPad
606 Bluetooth device in the internal ThinkPad CDC slot.
608 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
609 so it is kept across reboots and power-off.
611 Procfs notes:
613 If Bluetooth is installed, the following commands can be used:
615 echo enable > /proc/acpi/ibm/bluetooth
616 echo disable > /proc/acpi/ibm/bluetooth
618 Sysfs notes:
620 If the Bluetooth CDC card is installed, it can be enabled /
621 disabled through the "bluetooth_enable" thinkpad-acpi device
622 attribute, and its current status can also be queried.
624 enable:
625 0: disables Bluetooth / Bluetooth is disabled
626 1: enables Bluetooth / Bluetooth is enabled.
628 Note: this interface has been superseded by the generic rfkill
629 class. It has been deprecated, and it will be removed in year
630 2010.
632 rfkill controller switch "tpacpi_bluetooth_sw": refer to
633 Documentation/rfkill.txt for details.
636 Video output control -- /proc/acpi/ibm/video
637 --------------------------------------------
639 This feature allows control over the devices used for video output -
640 LCD, CRT or DVI (if available). The following commands are available:
642 echo lcd_enable > /proc/acpi/ibm/video
643 echo lcd_disable > /proc/acpi/ibm/video
644 echo crt_enable > /proc/acpi/ibm/video
645 echo crt_disable > /proc/acpi/ibm/video
646 echo dvi_enable > /proc/acpi/ibm/video
647 echo dvi_disable > /proc/acpi/ibm/video
648 echo auto_enable > /proc/acpi/ibm/video
649 echo auto_disable > /proc/acpi/ibm/video
650 echo expand_toggle > /proc/acpi/ibm/video
651 echo video_switch > /proc/acpi/ibm/video
653 NOTE: Access to this feature is restricted to processes owning the
654 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
655 enough with some versions of X.org to crash it.
657 Each video output device can be enabled or disabled individually.
658 Reading /proc/acpi/ibm/video shows the status of each device.
660 Automatic video switching can be enabled or disabled. When automatic
661 video switching is enabled, certain events (e.g. opening the lid,
662 docking or undocking) cause the video output device to change
663 automatically. While this can be useful, it also causes flickering
664 and, on the X40, video corruption. By disabling automatic switching,
665 the flickering or video corruption can be avoided.
667 The video_switch command cycles through the available video outputs
668 (it simulates the behavior of Fn-F7).
670 Video expansion can be toggled through this feature. This controls
671 whether the display is expanded to fill the entire LCD screen when a
672 mode with less than full resolution is used. Note that the current
673 video expansion status cannot be determined through this feature.
675 Note that on many models (particularly those using Radeon graphics
676 chips) the X driver configures the video card in a way which prevents
677 Fn-F7 from working. This also disables the video output switching
678 features of this driver, as it uses the same ACPI methods as
679 Fn-F7. Video switching on the console should still work.
681 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
684 ThinkLight control
685 ------------------
687 procfs: /proc/acpi/ibm/light
688 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
690 procfs notes:
692 The ThinkLight status can be read and set through the procfs interface. A
693 few models which do not make the status available will show the ThinkLight
694 status as "unknown". The available commands are:
696 echo on > /proc/acpi/ibm/light
697 echo off > /proc/acpi/ibm/light
699 sysfs notes:
701 The ThinkLight sysfs interface is documented by the LED class
702 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
703 is "tpacpi::thinklight".
705 Due to limitations in the sysfs LED class, if the status of the ThinkLight
706 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
707 It is impossible to know if the status returned through sysfs is valid.
710 CMOS/UCMS control
711 -----------------
713 procfs: /proc/acpi/ibm/cmos
714 sysfs device attribute: cmos_command
716 This feature is mostly used internally by the ACPI firmware to keep the legacy
717 CMOS NVRAM bits in sync with the current machine state, and to record this
718 state so that the ThinkPad will retain such settings across reboots.
720 Some of these commands actually perform actions in some ThinkPad models, but
721 this is expected to disappear more and more in newer models. As an example, in
722 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
723 real, but commands 0 to 2 don't control the mixer anymore (they have been
724 phased out) and just update the NVRAM.
726 The range of valid cmos command numbers is 0 to 21, but not all have an
727 effect and the behavior varies from model to model. Here is the behavior
728 on the X40 (tpb is the ThinkPad Buttons utility):
730 0 - Related to "Volume down" key press
731 1 - Related to "Volume up" key press
732 2 - Related to "Mute on" key press
733 3 - Related to "Access IBM" key press
734 4 - Related to "LCD brightness up" key press
735 5 - Related to "LCD brightness down" key press
736 11 - Related to "toggle screen expansion" key press/function
737 12 - Related to "ThinkLight on"
738 13 - Related to "ThinkLight off"
739 14 - Related to "ThinkLight" key press (toggle ThinkLight)
741 The cmos command interface is prone to firmware split-brain problems, as
742 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
743 exported just as a debug tool.
746 LED control
747 -----------
749 procfs: /proc/acpi/ibm/led
750 sysfs attributes: as per LED class, see below for names
752 Some of the LED indicators can be controlled through this feature. On
753 some older ThinkPad models, it is possible to query the status of the
754 LED indicators as well. Newer ThinkPads cannot query the real status
755 of the LED indicators.
757 Because misuse of the LEDs could induce an unaware user to perform
758 dangerous actions (like undocking or ejecting a bay device while the
759 buses are still active), or mask an important alarm (such as a nearly
760 empty battery, or a broken battery), access to most LEDs is
761 restricted.
763 Unrestricted access to all LEDs requires that thinkpad-acpi be
764 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
765 Distributions must never enable this option. Individual users that
766 are aware of the consequences are welcome to enabling it.
768 procfs notes:
770 The available commands are:
772 echo '<LED number> on' >/proc/acpi/ibm/led
773 echo '<LED number> off' >/proc/acpi/ibm/led
774 echo '<LED number> blink' >/proc/acpi/ibm/led
776 The <LED number> range is 0 to 15. The set of LEDs that can be
777 controlled varies from model to model. Here is the common ThinkPad
778 mapping:
780 0 - power
781 1 - battery (orange)
782 2 - battery (green)
783 3 - UltraBase/dock
784 4 - UltraBay
785 5 - UltraBase battery slot
786 6 - (unknown)
787 7 - standby
788 8 - dock status 1
789 9 - dock status 2
790 10, 11 - (unknown)
791 12 - thinkvantage
792 13, 14, 15 - (unknown)
794 All of the above can be turned on and off and can be made to blink.
796 sysfs notes:
798 The ThinkPad LED sysfs interface is described in detail by the LED class
799 documentation, in Documentation/leds-class.txt.
801 The LEDs are named (in LED ID order, from 0 to 12):
802 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
803 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
804 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
805 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
806 "tpacpi::thinkvantage".
808 Due to limitations in the sysfs LED class, if the status of the LED
809 indicators cannot be read due to an error, thinkpad-acpi will report it as
810 a brightness of zero (same as LED off).
812 If the thinkpad firmware doesn't support reading the current status,
813 trying to read the current LED brightness will just return whatever
814 brightness was last written to that attribute.
816 These LEDs can blink using hardware acceleration. To request that a
817 ThinkPad indicator LED should blink in hardware accelerated mode, use the
818 "timer" trigger, and leave the delay_on and delay_off parameters set to
819 zero (to request hardware acceleration autodetection).
821 LEDs that are known not to exist in a given ThinkPad model are not
822 made available through the sysfs interface. If you have a dock and you
823 notice there are LEDs listed for your ThinkPad that do not exist (and
824 are not in the dock), or if you notice that there are missing LEDs,
825 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
828 ACPI sounds -- /proc/acpi/ibm/beep
829 ----------------------------------
831 The BEEP method is used internally by the ACPI firmware to provide
832 audible alerts in various situations. This feature allows the same
833 sounds to be triggered manually.
835 The commands are non-negative integer numbers:
837 echo <number> >/proc/acpi/ibm/beep
839 The valid <number> range is 0 to 17. Not all numbers trigger sounds
840 and the sounds vary from model to model. Here is the behavior on the
841 X40:
843 0 - stop a sound in progress (but use 17 to stop 16)
844 2 - two beeps, pause, third beep ("low battery")
845 3 - single beep
846 4 - high, followed by low-pitched beep ("unable")
847 5 - single beep
848 6 - very high, followed by high-pitched beep ("AC/DC")
849 7 - high-pitched beep
850 9 - three short beeps
851 10 - very long beep
852 12 - low-pitched beep
853 15 - three high-pitched beeps repeating constantly, stop with 0
854 16 - one medium-pitched beep repeating constantly, stop with 17
855 17 - stop 16
858 Temperature sensors
859 -------------------
861 procfs: /proc/acpi/ibm/thermal
862 sysfs device attributes: (hwmon "thinkpad") temp*_input
864 Most ThinkPads include six or more separate temperature sensors but only
865 expose the CPU temperature through the standard ACPI methods. This
866 feature shows readings from up to eight different sensors on older
867 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
869 For example, on the X40, a typical output may be:
870 temperatures: 42 42 45 41 36 -128 33 -128
872 On the T43/p, a typical output may be:
873 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
875 The mapping of thermal sensors to physical locations varies depending on
876 system-board model (and thus, on ThinkPad model).
878 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
879 tries to track down these locations for various models.
881 Most (newer?) models seem to follow this pattern:
883 1: CPU
884 2: (depends on model)
885 3: (depends on model)
886 4: GPU
887 5: Main battery: main sensor
888 6: Bay battery: main sensor
889 7: Main battery: secondary sensor
890 8: Bay battery: secondary sensor
891 9-15: (depends on model)
893 For the R51 (source: Thomas Gruber):
894 2: Mini-PCI
895 3: Internal HDD
897 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
898 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
899 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
900 3: PCMCIA slot
901 9: MCH (northbridge) to DRAM Bus
902 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
903 card, under touchpad
904 11: Power regulator, underside of system board, below F2 key
906 The A31 has a very atypical layout for the thermal sensors
907 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
908 1: CPU
909 2: Main Battery: main sensor
910 3: Power Converter
911 4: Bay Battery: main sensor
912 5: MCH (northbridge)
913 6: PCMCIA/ambient
914 7: Main Battery: secondary sensor
915 8: Bay Battery: secondary sensor
918 Procfs notes:
919 Readings from sensors that are not available return -128.
920 No commands can be written to this file.
922 Sysfs notes:
923 Sensors that are not available return the ENXIO error. This
924 status may change at runtime, as there are hotplug thermal
925 sensors, like those inside the batteries and docks.
927 thinkpad-acpi thermal sensors are reported through the hwmon
928 subsystem, and follow all of the hwmon guidelines at
929 Documentation/hwmon.
932 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
933 ------------------------------------------------------------------------
935 This feature is marked EXPERIMENTAL because the implementation
936 directly accesses hardware registers and may not work as expected. USE
937 WITH CAUTION! To use this feature, you need to supply the
938 experimental=1 parameter when loading the module.
940 This feature dumps the values of 256 embedded controller
941 registers. Values which have changed since the last time the registers
942 were dumped are marked with a star:
944 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
945 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
946 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
947 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
948 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
949 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
950 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
951 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
952 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
953 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
954 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
955 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
956 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
957 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
958 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
959 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
960 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
961 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
963 This feature can be used to determine the register holding the fan
964 speed on some models. To do that, do the following:
966 - make sure the battery is fully charged
967 - make sure the fan is running
968 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
970 The first step makes sure various charging-related values don't
971 vary. The second ensures that the fan-related values do vary, since
972 the fan speed fluctuates a bit. The third will (hopefully) mark the
973 fan register with a star:
975 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
976 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
977 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
978 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
979 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
980 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
981 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
982 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
983 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
984 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
985 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
986 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
987 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
988 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
989 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
990 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
991 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
992 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
994 Another set of values that varies often is the temperature
995 readings. Since temperatures don't change vary fast, you can take
996 several quick dumps to eliminate them.
998 You can use a similar method to figure out the meaning of other
999 embedded controller registers - e.g. make sure nothing else changes
1000 except the charging or discharging battery to determine which
1001 registers contain the current battery capacity, etc. If you experiment
1002 with this, do send me your results (including some complete dumps with
1003 a description of the conditions when they were taken.)
1006 LCD brightness control
1007 ----------------------
1009 procfs: /proc/acpi/ibm/brightness
1010 sysfs backlight device "thinkpad_screen"
1012 This feature allows software control of the LCD brightness on ThinkPad
1013 models which don't have a hardware brightness slider.
1015 It has some limitations: the LCD backlight cannot be actually turned
1016 on or off by this interface, it just controls the backlight brightness
1017 level.
1019 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1020 has eight brightness levels, ranging from 0 to 7. Some of the levels
1021 may not be distinct. Later Lenovo models that implement the ACPI
1022 display backlight brightness control methods have 16 levels, ranging
1023 from 0 to 15.
1025 For IBM ThinkPads, there are two interfaces to the firmware for direct
1026 brightness control, EC and UCMS (or CMOS). To select which one should be
1027 used, use the brightness_mode module parameter: brightness_mode=1 selects
1028 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1029 mode with NVRAM backing (so that brightness changes are remembered across
1030 shutdown/reboot).
1032 The driver tries to select which interface to use from a table of
1033 defaults for each ThinkPad model. If it makes a wrong choice, please
1034 report this as a bug, so that we can fix it.
1036 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1038 When display backlight brightness controls are available through the
1039 standard ACPI interface, it is best to use it instead of this direct
1040 ThinkPad-specific interface. The driver will disable its native
1041 backlight brightness control interface if it detects that the standard
1042 ACPI interface is available in the ThinkPad.
1044 The brightness_enable module parameter can be used to control whether
1045 the LCD brightness control feature will be enabled when available.
1046 brightness_enable=0 forces it to be disabled. brightness_enable=1
1047 forces it to be enabled when available, even if the standard ACPI
1048 interface is also available.
1050 Procfs notes:
1052 The available commands are:
1054 echo up >/proc/acpi/ibm/brightness
1055 echo down >/proc/acpi/ibm/brightness
1056 echo 'level <level>' >/proc/acpi/ibm/brightness
1058 Sysfs notes:
1060 The interface is implemented through the backlight sysfs class, which is
1061 poorly documented at this time.
1063 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1064 it there will be the following attributes:
1066 max_brightness:
1067 Reads the maximum brightness the hardware can be set to.
1068 The minimum is always zero.
1070 actual_brightness:
1071 Reads what brightness the screen is set to at this instant.
1073 brightness:
1074 Writes request the driver to change brightness to the
1075 given value. Reads will tell you what brightness the
1076 driver is trying to set the display to when "power" is set
1077 to zero and the display has not been dimmed by a kernel
1078 power management event.
1080 power:
1081 power management mode, where 0 is "display on", and 1 to 3
1082 will dim the display backlight to brightness level 0
1083 because thinkpad-acpi cannot really turn the backlight
1084 off. Kernel power management events can temporarily
1085 increase the current power management level, i.e. they can
1086 dim the display.
1089 WARNING:
1091 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1092 interface and the ACPI-based backlight level change interface
1093 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1094 at the same time. The two will interact in bad ways, do funny things,
1095 and maybe reduce the life of the backlight lamps by needlessly kicking
1096 its level up and down at every change.
1099 Volume control (Console Audio control)
1100 --------------------------------------
1102 procfs: /proc/acpi/ibm/volume
1103 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1105 NOTE: by default, the volume control interface operates in read-only
1106 mode, as it is supposed to be used for on-screen-display purposes.
1107 The read/write mode can be enabled through the use of the
1108 "volume_control=1" module parameter.
1110 NOTE: distros are urged to not enable volume_control by default, this
1111 should be done by the local admin only. The ThinkPad UI is for the
1112 console audio control to be done through the volume keys only, and for
1113 the desktop environment to just provide on-screen-display feedback.
1114 Software volume control should be done only in the main AC97/HDA
1115 mixer.
1118 About the ThinkPad Console Audio control:
1120 ThinkPads have a built-in amplifier and muting circuit that drives the
1121 console headphone and speakers. This circuit is after the main AC97
1122 or HDA mixer in the audio path, and under exclusive control of the
1123 firmware.
1125 ThinkPads have three special hotkeys to interact with the console
1126 audio control: volume up, volume down and mute.
1128 It is worth noting that the normal way the mute function works (on
1129 ThinkPads that do not have a "mute LED") is:
1131 1. Press mute to mute. It will *always* mute, you can press it as
1132 many times as you want, and the sound will remain mute.
1134 2. Press either volume key to unmute the ThinkPad (it will _not_
1135 change the volume, it will just unmute).
1137 This is a very superior design when compared to the cheap software-only
1138 mute-toggle solution found on normal consumer laptops: you can be
1139 absolutely sure the ThinkPad will not make noise if you press the mute
1140 button, no matter the previous state.
1142 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1143 amplifiers driving the speakers and headphone output, and the firmware
1144 also handles volume control for the headphone and speakers on these
1145 ThinkPads without any help from the operating system (this volume
1146 control stage exists after the main AC97 or HDA mixer in the audio
1147 path).
1149 The newer Lenovo models only have firmware mute control, and depend on
1150 the main HDA mixer to do volume control (which is done by the operating
1151 system). In this case, the volume keys are filtered out for unmute
1152 key press (there are some firmware bugs in this area) and delivered as
1153 normal key presses to the operating system (thinkpad-acpi is not
1154 involved).
1157 The ThinkPad-ACPI volume control:
1159 The preferred way to interact with the Console Audio control is the
1160 ALSA interface.
1162 The legacy procfs interface allows one to read the current state,
1163 and if volume control is enabled, accepts the following commands:
1165 echo up >/proc/acpi/ibm/volume
1166 echo down >/proc/acpi/ibm/volume
1167 echo mute >/proc/acpi/ibm/volume
1168 echo unmute >/proc/acpi/ibm/volume
1169 echo 'level <level>' >/proc/acpi/ibm/volume
1171 The <level> number range is 0 to 14 although not all of them may be
1172 distinct. To unmute the volume after the mute command, use either the
1173 up or down command (the level command will not unmute the volume), or
1174 the unmute command.
1176 You can use the volume_capabilities parameter to tell the driver
1177 whether your thinkpad has volume control or mute-only control:
1178 volume_capabilities=1 for mixers with mute and volume control,
1179 volume_capabilities=2 for mixers with only mute control.
1181 If the driver misdetects the capabilities for your ThinkPad model,
1182 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1183 can update the driver.
1185 There are two strategies for volume control. To select which one
1186 should be used, use the volume_mode module parameter: volume_mode=1
1187 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1188 (so that volume/mute changes are remembered across shutdown/reboot).
1190 The driver will operate in volume_mode=3 by default. If that does not
1191 work well on your ThinkPad model, please report this to
1192 ibm-acpi-devel@lists.sourceforge.net.
1194 The driver supports the standard ALSA module parameters. If the ALSA
1195 mixer is disabled, the driver will disable all volume functionality.
1198 Fan control and monitoring: fan speed, fan enable/disable
1199 ---------------------------------------------------------
1201 procfs: /proc/acpi/ibm/fan
1202 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1203 pwm1_enable, fan2_input
1204 sysfs hwmon driver attributes: fan_watchdog
1206 NOTE NOTE NOTE: fan control operations are disabled by default for
1207 safety reasons. To enable them, the module parameter "fan_control=1"
1208 must be given to thinkpad-acpi.
1210 This feature attempts to show the current fan speed, control mode and
1211 other fan data that might be available. The speed is read directly
1212 from the hardware registers of the embedded controller. This is known
1213 to work on later R, T, X and Z series ThinkPads but may show a bogus
1214 value on other models.
1216 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1217 controlled separately, it shares the main fan control.
1219 Fan levels:
1221 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1222 stops the fan. The higher the level, the higher the fan speed, although
1223 adjacent levels often map to the same fan speed. 7 is the highest
1224 level, where the fan reaches the maximum recommended speed.
1226 Level "auto" means the EC changes the fan level according to some
1227 internal algorithm, usually based on readings from the thermal sensors.
1229 There is also a "full-speed" level, also known as "disengaged" level.
1230 In this level, the EC disables the speed-locked closed-loop fan control,
1231 and drives the fan as fast as it can go, which might exceed hardware
1232 limits, so use this level with caution.
1234 The fan usually ramps up or down slowly from one speed to another, and
1235 it is normal for the EC to take several seconds to react to fan
1236 commands. The full-speed level may take up to two minutes to ramp up to
1237 maximum speed, and in some ThinkPads, the tachometer readings go stale
1238 while the EC is transitioning to the full-speed level.
1240 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1241 monitoring all of the temperature sensor readings and you are ready to
1242 enable it if necessary to avoid overheating.
1244 An enabled fan in level "auto" may stop spinning if the EC decides the
1245 ThinkPad is cool enough and doesn't need the extra airflow. This is
1246 normal, and the EC will spin the fan up if the various thermal readings
1247 rise too much.
1249 On the X40, this seems to depend on the CPU and HDD temperatures.
1250 Specifically, the fan is turned on when either the CPU temperature
1251 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1252 fan is turned off when the CPU temperature drops to 49 degrees and the
1253 HDD temperature drops to 41 degrees. These thresholds cannot
1254 currently be controlled.
1256 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1257 certain conditions are met. It will override any fan programming done
1258 through thinkpad-acpi.
1260 The thinkpad-acpi kernel driver can be programmed to revert the fan
1261 level to a safe setting if userspace does not issue one of the procfs
1262 fan commands: "enable", "disable", "level" or "watchdog", or if there
1263 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1264 set to 1, manual mode) within a configurable amount of time of up to
1265 120 seconds. This functionality is called fan safety watchdog.
1267 Note that the watchdog timer stops after it enables the fan. It will be
1268 rearmed again automatically (using the same interval) when one of the
1269 above mentioned fan commands is received. The fan watchdog is,
1270 therefore, not suitable to protect against fan mode changes made through
1271 means other than the "enable", "disable", and "level" procfs fan
1272 commands, or the hwmon fan control sysfs interface.
1274 Procfs notes:
1276 The fan may be enabled or disabled with the following commands:
1278 echo enable >/proc/acpi/ibm/fan
1279 echo disable >/proc/acpi/ibm/fan
1281 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1282 will try to place it in a safe level if it is too slow or disabled.
1284 The fan level can be controlled with the command:
1286 echo 'level <level>' > /proc/acpi/ibm/fan
1288 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1289 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1290 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1291 "full-speed", and reports it as "disengaged" for backwards
1292 compatibility.
1294 On the X31 and X40 (and ONLY on those models), the fan speed can be
1295 controlled to a certain degree. Once the fan is running, it can be
1296 forced to run faster or slower with the following command:
1298 echo 'speed <speed>' > /proc/acpi/ibm/fan
1300 The sustainable range of fan speeds on the X40 appears to be from about
1301 3700 to about 7350. Values outside this range either do not have any
1302 effect or the fan speed eventually settles somewhere in that range. The
1303 fan cannot be stopped or started with this command. This functionality
1304 is incomplete, and not available through the sysfs interface.
1306 To program the safety watchdog, use the "watchdog" command.
1308 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1310 If you want to disable the watchdog, use 0 as the interval.
1312 Sysfs notes:
1314 The sysfs interface follows the hwmon subsystem guidelines for the most
1315 part, and the exception is the fan safety watchdog.
1317 Writes to any of the sysfs attributes may return the EINVAL error if
1318 that operation is not supported in a given ThinkPad or if the parameter
1319 is out-of-bounds, and EPERM if it is forbidden. They may also return
1320 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1321 to the firmware).
1323 Features not yet implemented by the driver return ENOSYS.
1325 hwmon device attribute pwm1_enable:
1326 0: PWM offline (fan is set to full-speed mode)
1327 1: Manual PWM control (use pwm1 to set fan level)
1328 2: Hardware PWM control (EC "auto" mode)
1329 3: reserved (Software PWM control, not implemented yet)
1331 Modes 0 and 2 are not supported by all ThinkPads, and the
1332 driver is not always able to detect this. If it does know a
1333 mode is unsupported, it will return -EINVAL.
1335 hwmon device attribute pwm1:
1336 Fan level, scaled from the firmware values of 0-7 to the hwmon
1337 scale of 0-255. 0 means fan stopped, 255 means highest normal
1338 speed (level 7).
1340 This attribute only commands the fan if pmw1_enable is set to 1
1341 (manual PWM control).
1343 hwmon device attribute fan1_input:
1344 Fan tachometer reading, in RPM. May go stale on certain
1345 ThinkPads while the EC transitions the PWM to offline mode,
1346 which can take up to two minutes. May return rubbish on older
1347 ThinkPads.
1349 hwmon device attribute fan2_input:
1350 Fan tachometer reading, in RPM, for the secondary fan.
1351 Available only on some ThinkPads. If the secondary fan is
1352 not installed, will always read 0.
1354 hwmon driver attribute fan_watchdog:
1355 Fan safety watchdog timer interval, in seconds. Minimum is
1356 1 second, maximum is 120 seconds. 0 disables the watchdog.
1358 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1360 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1361 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1362 would be the safest choice, though).
1365 WAN
1366 ---
1368 procfs: /proc/acpi/ibm/wan
1369 sysfs device attribute: wwan_enable (deprecated)
1370 sysfs rfkill class: switch "tpacpi_wwan_sw"
1372 This feature shows the presence and current state of the built-in
1373 Wireless WAN device.
1375 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1376 so it is kept across reboots and power-off.
1378 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1379 ThinkPad models which come with this module installed.
1381 Procfs notes:
1383 If the W-WAN card is installed, the following commands can be used:
1385 echo enable > /proc/acpi/ibm/wan
1386 echo disable > /proc/acpi/ibm/wan
1388 Sysfs notes:
1390 If the W-WAN card is installed, it can be enabled /
1391 disabled through the "wwan_enable" thinkpad-acpi device
1392 attribute, and its current status can also be queried.
1394 enable:
1395 0: disables WWAN card / WWAN card is disabled
1396 1: enables WWAN card / WWAN card is enabled.
1398 Note: this interface has been superseded by the generic rfkill
1399 class. It has been deprecated, and it will be removed in year
1400 2010.
1402 rfkill controller switch "tpacpi_wwan_sw": refer to
1403 Documentation/rfkill.txt for details.
1406 EXPERIMENTAL: UWB
1407 -----------------
1409 This feature is marked EXPERIMENTAL because it has not been extensively
1410 tested and validated in various ThinkPad models yet. The feature may not
1411 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1412 the experimental=1 parameter when loading the module.
1414 sysfs rfkill class: switch "tpacpi_uwb_sw"
1416 This feature exports an rfkill controller for the UWB device, if one is
1417 present and enabled in the BIOS.
1419 Sysfs notes:
1421 rfkill controller switch "tpacpi_uwb_sw": refer to
1422 Documentation/rfkill.txt for details.
1425 Multiple Commands, Module Parameters
1426 ------------------------------------
1428 Multiple commands can be written to the proc files in one shot by
1429 separating them with commas, for example:
1431 echo enable,0xffff > /proc/acpi/ibm/hotkey
1432 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1434 Commands can also be specified when loading the thinkpad-acpi module,
1435 for example:
1437 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1440 Enabling debugging output
1441 -------------------------
1443 The module takes a debug parameter which can be used to selectively
1444 enable various classes of debugging output, for example:
1446 modprobe thinkpad_acpi debug=0xffff
1448 will enable all debugging output classes. It takes a bitmask, so
1449 to enable more than one output class, just add their values.
1451 Debug bitmask Description
1452 0x8000 Disclose PID of userspace programs
1453 accessing some functions of the driver
1454 0x0001 Initialization and probing
1455 0x0002 Removal
1456 0x0004 RF Transmitter control (RFKILL)
1457 (bluetooth, WWAN, UWB...)
1458 0x0008 HKEY event interface, hotkeys
1459 0x0010 Fan control
1460 0x0020 Backlight brightness
1461 0x0040 Audio mixer/volume control
1463 There is also a kernel build option to enable more debugging
1464 information, which may be necessary to debug driver problems.
1466 The level of debugging information output by the driver can be changed
1467 at runtime through sysfs, using the driver attribute debug_level. The
1468 attribute takes the same bitmask as the debug module parameter above.
1471 Force loading of module
1472 -----------------------
1474 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1475 the module parameter force_load=1. Regardless of whether this works or
1476 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1479 Sysfs interface changelog:
1481 0x000100: Initial sysfs support, as a single platform driver and
1482 device.
1483 0x000200: Hot key support for 32 hot keys, and radio slider switch
1484 support.
1485 0x010000: Hot keys are now handled by default over the input
1486 layer, the radio switch generates input event EV_RADIO,
1487 and the driver enables hot key handling by default in
1488 the firmware.
1490 0x020000: ABI fix: added a separate hwmon platform device and
1491 driver, which must be located by name (thinkpad)
1492 and the hwmon class for libsensors4 (lm-sensors 3)
1493 compatibility. Moved all hwmon attributes to this
1494 new platform device.
1496 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1497 support. If you must, use it to know you should not
1498 start a userspace NVRAM poller (allows to detect when
1499 NVRAM is compiled out by the user because it is
1500 unneeded/undesired in the first place).
1501 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1502 and proper hotkey_mask semantics (version 8 of the
1503 NVRAM polling patch). Some development snapshots of
1504 0.18 had an earlier version that did strange things
1505 to hotkey_mask.
1507 0x020200: Add poll()/select() support to the following attributes:
1508 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1510 0x020300: hotkey enable/disable support removed, attributes
1511 hotkey_bios_enabled and hotkey_enable deprecated and
1512 marked for removal.
1514 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1515 to not exist in a given model are not registered with
1516 the LED sysfs class anymore.
1518 0x020500: Updated hotkey driver, hotkey_mask is always available
1519 and it is always able to disable hot keys. Very old
1520 thinkpads are properly supported. hotkey_bios_mask
1521 is deprecated and marked for removal.
1523 0x020600: Marker for backlight change event support.
1525 0x020700: Support for mute-only mixers.
1526 Volume control in read-only mode by default.
1527 Marker for ALSA mixer support.