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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 which uses a single volume up or volume down hotkey
296 press to unmute, as per the ThinkPad volume mixer user
297 interface. When in ACPI event mode, volume up/down/mute
298 events are reported by the firmware and can behave
299 differently (and that behaviour changes with firmware
300 version -- not just with firmware models -- as well as
301 OSI(Linux) state).
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 may 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 -
401 0x1002 0x01 FN+F2 IBM: battery (rare)
402 Lenovo: Screen lock
404 0x1003 0x02 FN+F3 Many IBM models always report
405 this hot key, even with hot keys
406 disabled or with Fn+F3 masked
407 off
408 IBM: screen lock, often turns
409 off the ThinkLight as side-effect
410 Lenovo: battery
412 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
413 semantics, i.e. sleep-to-RAM).
414 It is always generate some kind
415 of event, either the hot key
416 event or a ACPI sleep button
417 event. The firmware may
418 refuse to generate further FN+F4
419 key presses until a S3 or S4 ACPI
420 sleep cycle is performed or some
421 time passes.
423 0x1005 0x04 FN+F5 Radio. Enables/disables
424 the internal Bluetooth hardware
425 and W-WAN card if left in control
426 of the firmware. Does not affect
427 the WLAN card.
428 Should be used to turn on/off all
429 radios (Bluetooth+W-WAN+WLAN),
430 really.
432 0x1006 0x05 FN+F6 -
434 0x1007 0x06 FN+F7 Video output cycle.
435 Do you feel lucky today?
437 0x1008 0x07 FN+F8 IBM: toggle screen expand
438 Lenovo: configure UltraNav,
439 or toggle screen expand
441 0x1009 0x08 FN+F9 -
442 .. .. ..
443 0x100B 0x0A FN+F11 -
445 0x100C 0x0B FN+F12 Sleep to disk. You are always
446 supposed to handle it yourself,
447 either through the ACPI event,
448 or through a hotkey event.
449 The firmware may refuse to
450 generate further FN+F12 key
451 press events until a S3 or S4
452 ACPI sleep cycle is performed,
453 or some time passes.
455 0x100D 0x0C FN+BACKSPACE -
456 0x100E 0x0D FN+INSERT -
457 0x100F 0x0E FN+DELETE -
459 0x1010 0x0F FN+HOME Brightness up. This key is
460 always handled by the firmware
461 in IBM ThinkPads, even when
462 unmasked. Just leave it alone.
463 For Lenovo ThinkPads with a new
464 BIOS, it has to be handled either
465 by the ACPI OSI, or by userspace.
466 The driver does the right thing,
467 never mess with this.
468 0x1011 0x10 FN+END Brightness down. See brightness
469 up for details.
471 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is
472 always handled by the firmware,
473 even when unmasked.
475 0x1013 0x12 FN+PGDOWN -
477 0x1014 0x13 FN+SPACE Zoom key
479 0x1015 0x14 VOLUME UP Internal mixer volume up. This
480 key is always handled by the
481 firmware, even when unmasked.
482 NOTE: Lenovo seems to be changing
483 this.
484 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
485 key is always handled by the
486 firmware, even when unmasked.
487 NOTE: Lenovo seems to be changing
488 this.
489 0x1017 0x16 MUTE Mute internal mixer. This
490 key is always handled by the
491 firmware, even when unmasked.
493 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key
495 0x1019 0x18 unknown
496 .. .. ..
497 0x1020 0x1F unknown
499 The ThinkPad firmware does not allow one to differentiate when most hot
500 keys are pressed or released (either that, or we don't know how to, yet).
501 For these keys, the driver generates a set of events for a key press and
502 immediately issues the same set of events for a key release. It is
503 unknown by the driver if the ThinkPad firmware triggered these events on
504 hot key press or release, but the firmware will do it for either one, not
505 both.
507 If a key is mapped to KEY_RESERVED, it generates no input events at all.
508 If a key is mapped to KEY_UNKNOWN, it generates an input event that
509 includes an scan code. If a key is mapped to anything else, it will
510 generate input device EV_KEY events.
512 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
513 events for switches:
515 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch
516 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A
518 Non hotkey ACPI HKEY event map:
519 -------------------------------
521 Events that are not propagated by the driver, except for legacy
522 compatibility purposes when hotkey_report_mode is set to 1:
524 0x5001 Lid closed
525 0x5002 Lid opened
526 0x5009 Tablet swivel: switched to tablet mode
527 0x500A Tablet swivel: switched to normal mode
528 0x7000 Radio Switch may have changed state
530 Events that are never propagated by the driver:
532 0x2304 System is waking up from suspend to undock
533 0x2305 System is waking up from suspend to eject bay
534 0x2404 System is waking up from hibernation to undock
535 0x2405 System is waking up from hibernation to eject bay
536 0x5010 Brightness level changed/control event
538 Events that are propagated by the driver to userspace:
540 0x2313 ALARM: System is waking up from suspend because
541 the battery is nearly empty
542 0x2413 ALARM: System is waking up from hibernation because
543 the battery is nearly empty
544 0x3003 Bay ejection (see 0x2x05) complete, can sleep again
545 0x3006 Bay hotplug request (hint to power up SATA link when
546 the optical drive tray is ejected)
547 0x4003 Undocked (see 0x2x04), can sleep again
548 0x500B Tablet pen inserted into its storage bay
549 0x500C Tablet pen removed from its storage bay
550 0x6011 ALARM: battery is too hot
551 0x6012 ALARM: battery is extremely hot
552 0x6021 ALARM: a sensor is too hot
553 0x6022 ALARM: a sensor is extremely hot
554 0x6030 System thermal table changed
556 Battery nearly empty alarms are a last resort attempt to get the
557 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
558 cleanly (0x2413) before power is lost. They must be acted upon, as the
559 wake up caused by the firmware will have negated most safety nets...
561 When any of the "too hot" alarms happen, according to Lenovo the user
562 should suspend or hibernate the laptop (and in the case of battery
563 alarms, unplug the AC adapter) to let it cool down. These alarms do
564 signal that something is wrong, they should never happen on normal
565 operating conditions.
567 The "extremely hot" alarms are emergencies. According to Lenovo, the
568 operating system is to force either an immediate suspend or hibernate
569 cycle, or a system shutdown. Obviously, something is very wrong if this
570 happens.
572 Compatibility notes:
574 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
575 supported the input layer, and sent events over the procfs ACPI event
576 interface.
578 To avoid sending duplicate events over the input layer and the ACPI
579 event interface, thinkpad-acpi 0.16 implements a module parameter
580 (hotkey_report_mode), and also a sysfs device attribute with the same
581 name.
583 Make no mistake here: userspace is expected to switch to using the input
584 layer interface of thinkpad-acpi, together with the ACPI netlink event
585 interface in kernels 2.6.23 and later, or with the ACPI procfs event
586 interface in kernels 2.6.22 and earlier.
588 If no hotkey_report_mode module parameter is specified (or it is set to
589 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
590 and earlier, also allows one to change the hotkey_report_mode through
591 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
592 interface is available, hotkey_report_mode cannot be changed through
593 sysfs (it is read-only).
595 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
596 be changed later through sysfs (any writes will return -EPERM to signal
597 that hotkey_report_mode was locked. On 2.6.23 and later, where
598 hotkey_report_mode cannot be changed at all, writes will return -EACCES).
600 hotkey_report_mode set to 1 makes the driver export through the procfs
601 ACPI event interface all hot key presses (which are *also* sent to the
602 input layer). This is a legacy compatibility behaviour, and it is also
603 the default mode of operation for the driver.
605 hotkey_report_mode set to 2 makes the driver filter out the hot key
606 presses from the procfs ACPI event interface, so these events will only
607 be sent through the input layer. Userspace that has been updated to use
608 the thinkpad-acpi input layer interface should set hotkey_report_mode to
609 2.
611 Hot key press events are never sent to the ACPI netlink event interface.
612 Really up-to-date userspace under kernel 2.6.23 and later is to use the
613 netlink interface and the input layer interface, and don't bother at all
614 with hotkey_report_mode.
617 Brightness hotkey notes:
619 Don't mess with the brightness hotkeys in a Thinkpad. If you want
620 notifications for OSD, use the sysfs backlight class event support.
622 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
623 automatically for the cases were userspace has to do something to
624 implement brightness changes. When you override these events, you will
625 either fail to handle properly the ThinkPads that require explicit
626 action to change backlight brightness, or the ThinkPads that require
627 that no action be taken to work properly.
630 Bluetooth
631 ---------
633 procfs: /proc/acpi/ibm/bluetooth
634 sysfs device attribute: bluetooth_enable (deprecated)
635 sysfs rfkill class: switch "tpacpi_bluetooth_sw"
637 This feature shows the presence and current state of a ThinkPad
638 Bluetooth device in the internal ThinkPad CDC slot.
640 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
641 so it is kept across reboots and power-off.
643 Procfs notes:
645 If Bluetooth is installed, the following commands can be used:
647 echo enable > /proc/acpi/ibm/bluetooth
648 echo disable > /proc/acpi/ibm/bluetooth
650 Sysfs notes:
652 If the Bluetooth CDC card is installed, it can be enabled /
653 disabled through the "bluetooth_enable" thinkpad-acpi device
654 attribute, and its current status can also be queried.
656 enable:
657 0: disables Bluetooth / Bluetooth is disabled
658 1: enables Bluetooth / Bluetooth is enabled.
660 Note: this interface has been superseded by the generic rfkill
661 class. It has been deprecated, and it will be removed in year
662 2010.
664 rfkill controller switch "tpacpi_bluetooth_sw": refer to
665 Documentation/rfkill.txt for details.
668 Video output control -- /proc/acpi/ibm/video
669 --------------------------------------------
671 This feature allows control over the devices used for video output -
672 LCD, CRT or DVI (if available). The following commands are available:
674 echo lcd_enable > /proc/acpi/ibm/video
675 echo lcd_disable > /proc/acpi/ibm/video
676 echo crt_enable > /proc/acpi/ibm/video
677 echo crt_disable > /proc/acpi/ibm/video
678 echo dvi_enable > /proc/acpi/ibm/video
679 echo dvi_disable > /proc/acpi/ibm/video
680 echo auto_enable > /proc/acpi/ibm/video
681 echo auto_disable > /proc/acpi/ibm/video
682 echo expand_toggle > /proc/acpi/ibm/video
683 echo video_switch > /proc/acpi/ibm/video
685 NOTE: Access to this feature is restricted to processes owning the
686 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly
687 enough with some versions of X.org to crash it.
689 Each video output device can be enabled or disabled individually.
690 Reading /proc/acpi/ibm/video shows the status of each device.
692 Automatic video switching can be enabled or disabled. When automatic
693 video switching is enabled, certain events (e.g. opening the lid,
694 docking or undocking) cause the video output device to change
695 automatically. While this can be useful, it also causes flickering
696 and, on the X40, video corruption. By disabling automatic switching,
697 the flickering or video corruption can be avoided.
699 The video_switch command cycles through the available video outputs
700 (it simulates the behavior of Fn-F7).
702 Video expansion can be toggled through this feature. This controls
703 whether the display is expanded to fill the entire LCD screen when a
704 mode with less than full resolution is used. Note that the current
705 video expansion status cannot be determined through this feature.
707 Note that on many models (particularly those using Radeon graphics
708 chips) the X driver configures the video card in a way which prevents
709 Fn-F7 from working. This also disables the video output switching
710 features of this driver, as it uses the same ACPI methods as
711 Fn-F7. Video switching on the console should still work.
713 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
716 ThinkLight control
717 ------------------
719 procfs: /proc/acpi/ibm/light
720 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
722 procfs notes:
724 The ThinkLight status can be read and set through the procfs interface. A
725 few models which do not make the status available will show the ThinkLight
726 status as "unknown". The available commands are:
728 echo on > /proc/acpi/ibm/light
729 echo off > /proc/acpi/ibm/light
731 sysfs notes:
733 The ThinkLight sysfs interface is documented by the LED class
734 documentation, in Documentation/leds-class.txt. The ThinkLight LED name
735 is "tpacpi::thinklight".
737 Due to limitations in the sysfs LED class, if the status of the ThinkLight
738 cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
739 It is impossible to know if the status returned through sysfs is valid.
742 CMOS/UCMS control
743 -----------------
745 procfs: /proc/acpi/ibm/cmos
746 sysfs device attribute: cmos_command
748 This feature is mostly used internally by the ACPI firmware to keep the legacy
749 CMOS NVRAM bits in sync with the current machine state, and to record this
750 state so that the ThinkPad will retain such settings across reboots.
752 Some of these commands actually perform actions in some ThinkPad models, but
753 this is expected to disappear more and more in newer models. As an example, in
754 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
755 real, but commands 0 to 2 don't control the mixer anymore (they have been
756 phased out) and just update the NVRAM.
758 The range of valid cmos command numbers is 0 to 21, but not all have an
759 effect and the behavior varies from model to model. Here is the behavior
760 on the X40 (tpb is the ThinkPad Buttons utility):
762 0 - Related to "Volume down" key press
763 1 - Related to "Volume up" key press
764 2 - Related to "Mute on" key press
765 3 - Related to "Access IBM" key press
766 4 - Related to "LCD brightness up" key press
767 5 - Related to "LCD brightness down" key press
768 11 - Related to "toggle screen expansion" key press/function
769 12 - Related to "ThinkLight on"
770 13 - Related to "ThinkLight off"
771 14 - Related to "ThinkLight" key press (toggle ThinkLight)
773 The cmos command interface is prone to firmware split-brain problems, as
774 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
775 exported just as a debug tool.
778 LED control
779 -----------
781 procfs: /proc/acpi/ibm/led
782 sysfs attributes: as per LED class, see below for names
784 Some of the LED indicators can be controlled through this feature. On
785 some older ThinkPad models, it is possible to query the status of the
786 LED indicators as well. Newer ThinkPads cannot query the real status
787 of the LED indicators.
789 Because misuse of the LEDs could induce an unaware user to perform
790 dangerous actions (like undocking or ejecting a bay device while the
791 buses are still active), or mask an important alarm (such as a nearly
792 empty battery, or a broken battery), access to most LEDs is
793 restricted.
795 Unrestricted access to all LEDs requires that thinkpad-acpi be
796 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
797 Distributions must never enable this option. Individual users that
798 are aware of the consequences are welcome to enabling it.
800 procfs notes:
802 The available commands are:
804 echo '<LED number> on' >/proc/acpi/ibm/led
805 echo '<LED number> off' >/proc/acpi/ibm/led
806 echo '<LED number> blink' >/proc/acpi/ibm/led
808 The <LED number> range is 0 to 15. The set of LEDs that can be
809 controlled varies from model to model. Here is the common ThinkPad
810 mapping:
812 0 - power
813 1 - battery (orange)
814 2 - battery (green)
815 3 - UltraBase/dock
816 4 - UltraBay
817 5 - UltraBase battery slot
818 6 - (unknown)
819 7 - standby
820 8 - dock status 1
821 9 - dock status 2
822 10, 11 - (unknown)
823 12 - thinkvantage
824 13, 14, 15 - (unknown)
826 All of the above can be turned on and off and can be made to blink.
828 sysfs notes:
830 The ThinkPad LED sysfs interface is described in detail by the LED class
831 documentation, in Documentation/leds-class.txt.
833 The LEDs are named (in LED ID order, from 0 to 12):
834 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
835 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
836 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
837 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
838 "tpacpi::thinkvantage".
840 Due to limitations in the sysfs LED class, if the status of the LED
841 indicators cannot be read due to an error, thinkpad-acpi will report it as
842 a brightness of zero (same as LED off).
844 If the thinkpad firmware doesn't support reading the current status,
845 trying to read the current LED brightness will just return whatever
846 brightness was last written to that attribute.
848 These LEDs can blink using hardware acceleration. To request that a
849 ThinkPad indicator LED should blink in hardware accelerated mode, use the
850 "timer" trigger, and leave the delay_on and delay_off parameters set to
851 zero (to request hardware acceleration autodetection).
853 LEDs that are known not to exist in a given ThinkPad model are not
854 made available through the sysfs interface. If you have a dock and you
855 notice there are LEDs listed for your ThinkPad that do not exist (and
856 are not in the dock), or if you notice that there are missing LEDs,
857 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.
860 ACPI sounds -- /proc/acpi/ibm/beep
861 ----------------------------------
863 The BEEP method is used internally by the ACPI firmware to provide
864 audible alerts in various situations. This feature allows the same
865 sounds to be triggered manually.
867 The commands are non-negative integer numbers:
869 echo <number> >/proc/acpi/ibm/beep
871 The valid <number> range is 0 to 17. Not all numbers trigger sounds
872 and the sounds vary from model to model. Here is the behavior on the
873 X40:
875 0 - stop a sound in progress (but use 17 to stop 16)
876 2 - two beeps, pause, third beep ("low battery")
877 3 - single beep
878 4 - high, followed by low-pitched beep ("unable")
879 5 - single beep
880 6 - very high, followed by high-pitched beep ("AC/DC")
881 7 - high-pitched beep
882 9 - three short beeps
883 10 - very long beep
884 12 - low-pitched beep
885 15 - three high-pitched beeps repeating constantly, stop with 0
886 16 - one medium-pitched beep repeating constantly, stop with 17
887 17 - stop 16
890 Temperature sensors
891 -------------------
893 procfs: /proc/acpi/ibm/thermal
894 sysfs device attributes: (hwmon "thinkpad") temp*_input
896 Most ThinkPads include six or more separate temperature sensors but only
897 expose the CPU temperature through the standard ACPI methods. This
898 feature shows readings from up to eight different sensors on older
899 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
901 For example, on the X40, a typical output may be:
902 temperatures: 42 42 45 41 36 -128 33 -128
904 On the T43/p, a typical output may be:
905 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
907 The mapping of thermal sensors to physical locations varies depending on
908 system-board model (and thus, on ThinkPad model).
910 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
911 tries to track down these locations for various models.
913 Most (newer?) models seem to follow this pattern:
915 1: CPU
916 2: (depends on model)
917 3: (depends on model)
918 4: GPU
919 5: Main battery: main sensor
920 6: Bay battery: main sensor
921 7: Main battery: secondary sensor
922 8: Bay battery: secondary sensor
923 9-15: (depends on model)
925 For the R51 (source: Thomas Gruber):
926 2: Mini-PCI
927 3: Internal HDD
929 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
930 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
931 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
932 3: PCMCIA slot
933 9: MCH (northbridge) to DRAM Bus
934 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
935 card, under touchpad
936 11: Power regulator, underside of system board, below F2 key
938 The A31 has a very atypical layout for the thermal sensors
939 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
940 1: CPU
941 2: Main Battery: main sensor
942 3: Power Converter
943 4: Bay Battery: main sensor
944 5: MCH (northbridge)
945 6: PCMCIA/ambient
946 7: Main Battery: secondary sensor
947 8: Bay Battery: secondary sensor
950 Procfs notes:
951 Readings from sensors that are not available return -128.
952 No commands can be written to this file.
954 Sysfs notes:
955 Sensors that are not available return the ENXIO error. This
956 status may change at runtime, as there are hotplug thermal
957 sensors, like those inside the batteries and docks.
959 thinkpad-acpi thermal sensors are reported through the hwmon
960 subsystem, and follow all of the hwmon guidelines at
961 Documentation/hwmon.
964 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
965 ------------------------------------------------------------------------
967 This feature is marked EXPERIMENTAL because the implementation
968 directly accesses hardware registers and may not work as expected. USE
969 WITH CAUTION! To use this feature, you need to supply the
970 experimental=1 parameter when loading the module.
972 This feature dumps the values of 256 embedded controller
973 registers. Values which have changed since the last time the registers
974 were dumped are marked with a star:
976 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
977 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
978 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
979 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
980 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
981 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
982 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
983 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
984 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
985 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
986 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
987 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
988 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
989 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
990 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
991 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
992 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
993 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
995 This feature can be used to determine the register holding the fan
996 speed on some models. To do that, do the following:
998 - make sure the battery is fully charged
999 - make sure the fan is running
1000 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
1002 The first step makes sure various charging-related values don't
1003 vary. The second ensures that the fan-related values do vary, since
1004 the fan speed fluctuates a bit. The third will (hopefully) mark the
1005 fan register with a star:
1007 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1008 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
1009 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
1010 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
1011 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
1012 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
1013 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
1014 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
1015 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
1016 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
1017 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
1018 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1019 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
1020 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1021 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1022 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1023 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
1024 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
1026 Another set of values that varies often is the temperature
1027 readings. Since temperatures don't change vary fast, you can take
1028 several quick dumps to eliminate them.
1030 You can use a similar method to figure out the meaning of other
1031 embedded controller registers - e.g. make sure nothing else changes
1032 except the charging or discharging battery to determine which
1033 registers contain the current battery capacity, etc. If you experiment
1034 with this, do send me your results (including some complete dumps with
1035 a description of the conditions when they were taken.)
1038 LCD brightness control
1039 ----------------------
1041 procfs: /proc/acpi/ibm/brightness
1042 sysfs backlight device "thinkpad_screen"
1044 This feature allows software control of the LCD brightness on ThinkPad
1045 models which don't have a hardware brightness slider.
1047 It has some limitations: the LCD backlight cannot be actually turned
1048 on or off by this interface, it just controls the backlight brightness
1049 level.
1051 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1052 has eight brightness levels, ranging from 0 to 7. Some of the levels
1053 may not be distinct. Later Lenovo models that implement the ACPI
1054 display backlight brightness control methods have 16 levels, ranging
1055 from 0 to 15.
1057 For IBM ThinkPads, there are two interfaces to the firmware for direct
1058 brightness control, EC and UCMS (or CMOS). To select which one should be
1059 used, use the brightness_mode module parameter: brightness_mode=1 selects
1060 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
1061 mode with NVRAM backing (so that brightness changes are remembered across
1062 shutdown/reboot).
1064 The driver tries to select which interface to use from a table of
1065 defaults for each ThinkPad model. If it makes a wrong choice, please
1066 report this as a bug, so that we can fix it.
1068 Lenovo ThinkPads only support brightness_mode=2 (UCMS).
1070 When display backlight brightness controls are available through the
1071 standard ACPI interface, it is best to use it instead of this direct
1072 ThinkPad-specific interface. The driver will disable its native
1073 backlight brightness control interface if it detects that the standard
1074 ACPI interface is available in the ThinkPad.
1076 The brightness_enable module parameter can be used to control whether
1077 the LCD brightness control feature will be enabled when available.
1078 brightness_enable=0 forces it to be disabled. brightness_enable=1
1079 forces it to be enabled when available, even if the standard ACPI
1080 interface is also available.
1082 Procfs notes:
1084 The available commands are:
1086 echo up >/proc/acpi/ibm/brightness
1087 echo down >/proc/acpi/ibm/brightness
1088 echo 'level <level>' >/proc/acpi/ibm/brightness
1090 Sysfs notes:
1092 The interface is implemented through the backlight sysfs class, which is
1093 poorly documented at this time.
1095 Locate the thinkpad_screen device under /sys/class/backlight, and inside
1096 it there will be the following attributes:
1098 max_brightness:
1099 Reads the maximum brightness the hardware can be set to.
1100 The minimum is always zero.
1102 actual_brightness:
1103 Reads what brightness the screen is set to at this instant.
1105 brightness:
1106 Writes request the driver to change brightness to the
1107 given value. Reads will tell you what brightness the
1108 driver is trying to set the display to when "power" is set
1109 to zero and the display has not been dimmed by a kernel
1110 power management event.
1112 power:
1113 power management mode, where 0 is "display on", and 1 to 3
1114 will dim the display backlight to brightness level 0
1115 because thinkpad-acpi cannot really turn the backlight
1116 off. Kernel power management events can temporarily
1117 increase the current power management level, i.e. they can
1118 dim the display.
1121 WARNING:
1123 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change
1124 interface and the ACPI-based backlight level change interface
1125 (available on newer BIOSes, and driven by the Linux ACPI video driver)
1126 at the same time. The two will interact in bad ways, do funny things,
1127 and maybe reduce the life of the backlight lamps by needlessly kicking
1128 its level up and down at every change.
1131 Volume control (Console Audio control)
1132 --------------------------------------
1134 procfs: /proc/acpi/ibm/volume
1135 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
1137 NOTE: by default, the volume control interface operates in read-only
1138 mode, as it is supposed to be used for on-screen-display purposes.
1139 The read/write mode can be enabled through the use of the
1140 "volume_control=1" module parameter.
1142 NOTE: distros are urged to not enable volume_control by default, this
1143 should be done by the local admin only. The ThinkPad UI is for the
1144 console audio control to be done through the volume keys only, and for
1145 the desktop environment to just provide on-screen-display feedback.
1146 Software volume control should be done only in the main AC97/HDA
1147 mixer.
1150 About the ThinkPad Console Audio control:
1152 ThinkPads have a built-in amplifier and muting circuit that drives the
1153 console headphone and speakers. This circuit is after the main AC97
1154 or HDA mixer in the audio path, and under exclusive control of the
1155 firmware.
1157 ThinkPads have three special hotkeys to interact with the console
1158 audio control: volume up, volume down and mute.
1160 It is worth noting that the normal way the mute function works (on
1161 ThinkPads that do not have a "mute LED") is:
1163 1. Press mute to mute. It will *always* mute, you can press it as
1164 many times as you want, and the sound will remain mute.
1166 2. Press either volume key to unmute the ThinkPad (it will _not_
1167 change the volume, it will just unmute).
1169 This is a very superior design when compared to the cheap software-only
1170 mute-toggle solution found on normal consumer laptops: you can be
1171 absolutely sure the ThinkPad will not make noise if you press the mute
1172 button, no matter the previous state.
1174 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
1175 amplifiers driving the speakers and headphone output, and the firmware
1176 also handles volume control for the headphone and speakers on these
1177 ThinkPads without any help from the operating system (this volume
1178 control stage exists after the main AC97 or HDA mixer in the audio
1179 path).
1181 The newer Lenovo models only have firmware mute control, and depend on
1182 the main HDA mixer to do volume control (which is done by the operating
1183 system). In this case, the volume keys are filtered out for unmute
1184 key press (there are some firmware bugs in this area) and delivered as
1185 normal key presses to the operating system (thinkpad-acpi is not
1186 involved).
1189 The ThinkPad-ACPI volume control:
1191 The preferred way to interact with the Console Audio control is the
1192 ALSA interface.
1194 The legacy procfs interface allows one to read the current state,
1195 and if volume control is enabled, accepts the following commands:
1197 echo up >/proc/acpi/ibm/volume
1198 echo down >/proc/acpi/ibm/volume
1199 echo mute >/proc/acpi/ibm/volume
1200 echo unmute >/proc/acpi/ibm/volume
1201 echo 'level <level>' >/proc/acpi/ibm/volume
1203 The <level> number range is 0 to 14 although not all of them may be
1204 distinct. To unmute the volume after the mute command, use either the
1205 up or down command (the level command will not unmute the volume), or
1206 the unmute command.
1208 You can use the volume_capabilities parameter to tell the driver
1209 whether your thinkpad has volume control or mute-only control:
1210 volume_capabilities=1 for mixers with mute and volume control,
1211 volume_capabilities=2 for mixers with only mute control.
1213 If the driver misdetects the capabilities for your ThinkPad model,
1214 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
1215 can update the driver.
1217 There are two strategies for volume control. To select which one
1218 should be used, use the volume_mode module parameter: volume_mode=1
1219 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
1220 (so that volume/mute changes are remembered across shutdown/reboot).
1222 The driver will operate in volume_mode=3 by default. If that does not
1223 work well on your ThinkPad model, please report this to
1224 ibm-acpi-devel@lists.sourceforge.net.
1226 The driver supports the standard ALSA module parameters. If the ALSA
1227 mixer is disabled, the driver will disable all volume functionality.
1230 Fan control and monitoring: fan speed, fan enable/disable
1231 ---------------------------------------------------------
1233 procfs: /proc/acpi/ibm/fan
1234 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1235 pwm1_enable, fan2_input
1236 sysfs hwmon driver attributes: fan_watchdog
1238 NOTE NOTE NOTE: fan control operations are disabled by default for
1239 safety reasons. To enable them, the module parameter "fan_control=1"
1240 must be given to thinkpad-acpi.
1242 This feature attempts to show the current fan speed, control mode and
1243 other fan data that might be available. The speed is read directly
1244 from the hardware registers of the embedded controller. This is known
1245 to work on later R, T, X and Z series ThinkPads but may show a bogus
1246 value on other models.
1248 Some Lenovo ThinkPads support a secondary fan. This fan cannot be
1249 controlled separately, it shares the main fan control.
1251 Fan levels:
1253 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1254 stops the fan. The higher the level, the higher the fan speed, although
1255 adjacent levels often map to the same fan speed. 7 is the highest
1256 level, where the fan reaches the maximum recommended speed.
1258 Level "auto" means the EC changes the fan level according to some
1259 internal algorithm, usually based on readings from the thermal sensors.
1261 There is also a "full-speed" level, also known as "disengaged" level.
1262 In this level, the EC disables the speed-locked closed-loop fan control,
1263 and drives the fan as fast as it can go, which might exceed hardware
1264 limits, so use this level with caution.
1266 The fan usually ramps up or down slowly from one speed to another, and
1267 it is normal for the EC to take several seconds to react to fan
1268 commands. The full-speed level may take up to two minutes to ramp up to
1269 maximum speed, and in some ThinkPads, the tachometer readings go stale
1270 while the EC is transitioning to the full-speed level.
1272 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1273 monitoring all of the temperature sensor readings and you are ready to
1274 enable it if necessary to avoid overheating.
1276 An enabled fan in level "auto" may stop spinning if the EC decides the
1277 ThinkPad is cool enough and doesn't need the extra airflow. This is
1278 normal, and the EC will spin the fan up if the various thermal readings
1279 rise too much.
1281 On the X40, this seems to depend on the CPU and HDD temperatures.
1282 Specifically, the fan is turned on when either the CPU temperature
1283 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1284 fan is turned off when the CPU temperature drops to 49 degrees and the
1285 HDD temperature drops to 41 degrees. These thresholds cannot
1286 currently be controlled.
1288 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1289 certain conditions are met. It will override any fan programming done
1290 through thinkpad-acpi.
1292 The thinkpad-acpi kernel driver can be programmed to revert the fan
1293 level to a safe setting if userspace does not issue one of the procfs
1294 fan commands: "enable", "disable", "level" or "watchdog", or if there
1295 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1296 set to 1, manual mode) within a configurable amount of time of up to
1297 120 seconds. This functionality is called fan safety watchdog.
1299 Note that the watchdog timer stops after it enables the fan. It will be
1300 rearmed again automatically (using the same interval) when one of the
1301 above mentioned fan commands is received. The fan watchdog is,
1302 therefore, not suitable to protect against fan mode changes made through
1303 means other than the "enable", "disable", and "level" procfs fan
1304 commands, or the hwmon fan control sysfs interface.
1306 Procfs notes:
1308 The fan may be enabled or disabled with the following commands:
1310 echo enable >/proc/acpi/ibm/fan
1311 echo disable >/proc/acpi/ibm/fan
1313 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1314 will try to place it in a safe level if it is too slow or disabled.
1316 The fan level can be controlled with the command:
1318 echo 'level <level>' > /proc/acpi/ibm/fan
1320 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1321 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1322 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1323 "full-speed", and reports it as "disengaged" for backwards
1324 compatibility.
1326 On the X31 and X40 (and ONLY on those models), the fan speed can be
1327 controlled to a certain degree. Once the fan is running, it can be
1328 forced to run faster or slower with the following command:
1330 echo 'speed <speed>' > /proc/acpi/ibm/fan
1332 The sustainable range of fan speeds on the X40 appears to be from about
1333 3700 to about 7350. Values outside this range either do not have any
1334 effect or the fan speed eventually settles somewhere in that range. The
1335 fan cannot be stopped or started with this command. This functionality
1336 is incomplete, and not available through the sysfs interface.
1338 To program the safety watchdog, use the "watchdog" command.
1340 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1342 If you want to disable the watchdog, use 0 as the interval.
1344 Sysfs notes:
1346 The sysfs interface follows the hwmon subsystem guidelines for the most
1347 part, and the exception is the fan safety watchdog.
1349 Writes to any of the sysfs attributes may return the EINVAL error if
1350 that operation is not supported in a given ThinkPad or if the parameter
1351 is out-of-bounds, and EPERM if it is forbidden. They may also return
1352 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1353 to the firmware).
1355 Features not yet implemented by the driver return ENOSYS.
1357 hwmon device attribute pwm1_enable:
1358 0: PWM offline (fan is set to full-speed mode)
1359 1: Manual PWM control (use pwm1 to set fan level)
1360 2: Hardware PWM control (EC "auto" mode)
1361 3: reserved (Software PWM control, not implemented yet)
1363 Modes 0 and 2 are not supported by all ThinkPads, and the
1364 driver is not always able to detect this. If it does know a
1365 mode is unsupported, it will return -EINVAL.
1367 hwmon device attribute pwm1:
1368 Fan level, scaled from the firmware values of 0-7 to the hwmon
1369 scale of 0-255. 0 means fan stopped, 255 means highest normal
1370 speed (level 7).
1372 This attribute only commands the fan if pmw1_enable is set to 1
1373 (manual PWM control).
1375 hwmon device attribute fan1_input:
1376 Fan tachometer reading, in RPM. May go stale on certain
1377 ThinkPads while the EC transitions the PWM to offline mode,
1378 which can take up to two minutes. May return rubbish on older
1379 ThinkPads.
1381 hwmon device attribute fan2_input:
1382 Fan tachometer reading, in RPM, for the secondary fan.
1383 Available only on some ThinkPads. If the secondary fan is
1384 not installed, will always read 0.
1386 hwmon driver attribute fan_watchdog:
1387 Fan safety watchdog timer interval, in seconds. Minimum is
1388 1 second, maximum is 120 seconds. 0 disables the watchdog.
1390 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1392 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1393 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1394 would be the safest choice, though).
1397 WAN
1398 ---
1400 procfs: /proc/acpi/ibm/wan
1401 sysfs device attribute: wwan_enable (deprecated)
1402 sysfs rfkill class: switch "tpacpi_wwan_sw"
1404 This feature shows the presence and current state of the built-in
1405 Wireless WAN device.
1407 If the ThinkPad supports it, the WWAN state is stored in NVRAM,
1408 so it is kept across reboots and power-off.
1410 It was tested on a Lenovo ThinkPad X60. It should probably work on other
1411 ThinkPad models which come with this module installed.
1413 Procfs notes:
1415 If the W-WAN card is installed, the following commands can be used:
1417 echo enable > /proc/acpi/ibm/wan
1418 echo disable > /proc/acpi/ibm/wan
1420 Sysfs notes:
1422 If the W-WAN card is installed, it can be enabled /
1423 disabled through the "wwan_enable" thinkpad-acpi device
1424 attribute, and its current status can also be queried.
1426 enable:
1427 0: disables WWAN card / WWAN card is disabled
1428 1: enables WWAN card / WWAN card is enabled.
1430 Note: this interface has been superseded by the generic rfkill
1431 class. It has been deprecated, and it will be removed in year
1432 2010.
1434 rfkill controller switch "tpacpi_wwan_sw": refer to
1435 Documentation/rfkill.txt for details.
1438 EXPERIMENTAL: UWB
1439 -----------------
1441 This feature is marked EXPERIMENTAL because it has not been extensively
1442 tested and validated in various ThinkPad models yet. The feature may not
1443 work as expected. USE WITH CAUTION! To use this feature, you need to supply
1444 the experimental=1 parameter when loading the module.
1446 sysfs rfkill class: switch "tpacpi_uwb_sw"
1448 This feature exports an rfkill controller for the UWB device, if one is
1449 present and enabled in the BIOS.
1451 Sysfs notes:
1453 rfkill controller switch "tpacpi_uwb_sw": refer to
1454 Documentation/rfkill.txt for details.
1457 Multiple Commands, Module Parameters
1458 ------------------------------------
1460 Multiple commands can be written to the proc files in one shot by
1461 separating them with commas, for example:
1463 echo enable,0xffff > /proc/acpi/ibm/hotkey
1464 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1466 Commands can also be specified when loading the thinkpad-acpi module,
1467 for example:
1469 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1472 Enabling debugging output
1473 -------------------------
1475 The module takes a debug parameter which can be used to selectively
1476 enable various classes of debugging output, for example:
1478 modprobe thinkpad_acpi debug=0xffff
1480 will enable all debugging output classes. It takes a bitmask, so
1481 to enable more than one output class, just add their values.
1483 Debug bitmask Description
1484 0x8000 Disclose PID of userspace programs
1485 accessing some functions of the driver
1486 0x0001 Initialization and probing
1487 0x0002 Removal
1488 0x0004 RF Transmitter control (RFKILL)
1489 (bluetooth, WWAN, UWB...)
1490 0x0008 HKEY event interface, hotkeys
1491 0x0010 Fan control
1492 0x0020 Backlight brightness
1493 0x0040 Audio mixer/volume control
1495 There is also a kernel build option to enable more debugging
1496 information, which may be necessary to debug driver problems.
1498 The level of debugging information output by the driver can be changed
1499 at runtime through sysfs, using the driver attribute debug_level. The
1500 attribute takes the same bitmask as the debug module parameter above.
1503 Force loading of module
1504 -----------------------
1506 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1507 the module parameter force_load=1. Regardless of whether this works or
1508 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1511 Sysfs interface changelog:
1513 0x000100: Initial sysfs support, as a single platform driver and
1514 device.
1515 0x000200: Hot key support for 32 hot keys, and radio slider switch
1516 support.
1517 0x010000: Hot keys are now handled by default over the input
1518 layer, the radio switch generates input event EV_RADIO,
1519 and the driver enables hot key handling by default in
1520 the firmware.
1522 0x020000: ABI fix: added a separate hwmon platform device and
1523 driver, which must be located by name (thinkpad)
1524 and the hwmon class for libsensors4 (lm-sensors 3)
1525 compatibility. Moved all hwmon attributes to this
1526 new platform device.
1528 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1529 support. If you must, use it to know you should not
1530 start a userspace NVRAM poller (allows to detect when
1531 NVRAM is compiled out by the user because it is
1532 unneeded/undesired in the first place).
1533 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1534 and proper hotkey_mask semantics (version 8 of the
1535 NVRAM polling patch). Some development snapshots of
1536 0.18 had an earlier version that did strange things
1537 to hotkey_mask.
1539 0x020200: Add poll()/select() support to the following attributes:
1540 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1542 0x020300: hotkey enable/disable support removed, attributes
1543 hotkey_bios_enabled and hotkey_enable deprecated and
1544 marked for removal.
1546 0x020400: Marker for 16 LEDs support. Also, LEDs that are known
1547 to not exist in a given model are not registered with
1548 the LED sysfs class anymore.
1550 0x020500: Updated hotkey driver, hotkey_mask is always available
1551 and it is always able to disable hot keys. Very old
1552 thinkpads are properly supported. hotkey_bios_mask
1553 is deprecated and marked for removal.
1555 0x020600: Marker for backlight change event support.
1557 0x020700: Support for mute-only mixers.
1558 Volume control in read-only mode by default.
1559 Marker for ALSA mixer support.