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authorCarlos Corbacho <carlos@strangeworlds.co.uk>2008-02-08 20:32:09 -0500
committerLen Brown <len.brown@intel.com>2008-02-09 04:15:23 -0500
commitf191dc6b55cf92eb8e1f48b41533ecf4d6161569 (patch)
tree0e2fe73b8b8e0daa59f38c3c3ee01d3b26199915 /Documentation/laptops
parentd6ff3655773a1810b15da942c40478bf5217e390 (diff)
thinkpad-acpi - Move thinkpad-acpi.txt to Documentation/laptops
Also update references to thinkpad-acpi.txt in Kconfig. Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> CC: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation/laptops')
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-rw-r--r--Documentation/laptops/thinkpad-acpi.txt1365
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diff --git a/Documentation/laptops/00-INDEX b/Documentation/laptops/00-INDEX
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@@ -1,2 +1,4 @@
100-INDEX 100-INDEX
2 - This file 2 - This file
3thinkpad-acpi.txt
4 - information on the (IBM and Lenovo) ThinkPad ACPI Extras driver.
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
new file mode 100644
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@@ -0,0 +1,1365 @@
1 ThinkPad ACPI Extras Driver
2
3 Version 0.19
4 January 06th, 2008
5
6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
8 http://ibm-acpi.sf.net/
9
10
11This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
12supports various features of these laptops which are accessible
13through the ACPI and ACPI EC framework, but not otherwise fully
14supported by the generic Linux ACPI drivers.
15
16This driver used to be named ibm-acpi until kernel 2.6.21 and release
170.13-20070314. It used to be in the drivers/acpi tree, but it was
18moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
192.6.22, and release 0.14.
20
21
22Status
23------
24
25The features currently supported are the following (see below for
26detailed description):
27
28 - Fn key combinations
29 - Bluetooth enable and disable
30 - video output switching, expansion control
31 - ThinkLight on and off
32 - limited docking and undocking
33 - UltraBay eject
34 - CMOS control
35 - LED control
36 - ACPI sounds
37 - temperature sensors
38 - Experimental: embedded controller register dump
39 - LCD brightness control
40 - Volume control
41 - Fan control and monitoring: fan speed, fan enable/disable
42 - Experimental: WAN enable and disable
43
44A compatibility table by model and feature is maintained on the web
45site, http://ibm-acpi.sf.net/. I appreciate any success or failure
46reports, especially if they add to or correct the compatibility table.
47Please include the following information in your report:
48
49 - ThinkPad model name
50 - a copy of your DSDT, from /proc/acpi/dsdt
51 - a copy of the output of dmidecode, with serial numbers
52 and UUIDs masked off
53 - which driver features work and which don't
54 - the observed behavior of non-working features
55
56Any other comments or patches are also more than welcome.
57
58
59Installation
60------------
61
62If you are compiling this driver as included in the Linux kernel
63sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
64enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
65thinkpad-specific bay functionality.
66
67Features
68--------
69
70The driver exports two different interfaces to userspace, which can be
71used to access the features it provides. One is a legacy procfs-based
72interface, which will be removed at some time in the distant future.
73The other is a new sysfs-based interface which is not complete yet.
74
75The procfs interface creates the /proc/acpi/ibm directory. There is a
76file under that directory for each feature it supports. The procfs
77interface is mostly frozen, and will change very little if at all: it
78will not be extended to add any new functionality in the driver, instead
79all new functionality will be implemented on the sysfs interface.
80
81The sysfs interface tries to blend in the generic Linux sysfs subsystems
82and classes as much as possible. Since some of these subsystems are not
83yet ready or stabilized, it is expected that this interface will change,
84and any and all userspace programs must deal with it.
85
86
87Notes about the sysfs interface:
88
89Unlike what was done with the procfs interface, correctness when talking
90to the sysfs interfaces will be enforced, as will correctness in the
91thinkpad-acpi's implementation of sysfs interfaces.
92
93Also, any bugs in the thinkpad-acpi sysfs driver code or in the
94thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
95maximum correctness, even if that means changing an interface in
96non-compatible ways. As these interfaces mature both in the kernel and
97in thinkpad-acpi, such changes should become quite rare.
98
99Applications interfacing to the thinkpad-acpi sysfs interfaces must
100follow all sysfs guidelines and correctly process all errors (the sysfs
101interface makes extensive use of errors). File descriptors and open /
102close operations to the sysfs inodes must also be properly implemented.
103
104The version of thinkpad-acpi's sysfs interface is exported by the driver
105as a driver attribute (see below).
106
107Sysfs driver attributes are on the driver's sysfs attribute space,
108for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
109/sys/bus/platform/drivers/thinkpad_hwmon/
110
111Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
112space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
113
114Sysfs device attributes for the sensors and fan are on the
115thinkpad_hwmon device's sysfs attribute space, but you should locate it
116looking for a hwmon device with the name attribute of "thinkpad".
117
118Driver version
119--------------
120
121procfs: /proc/acpi/ibm/driver
122sysfs driver attribute: version
123
124The driver name and version. No commands can be written to this file.
125
126Sysfs interface version
127-----------------------
128
129sysfs driver attribute: interface_version
130
131Version of the thinkpad-acpi sysfs interface, as an unsigned long
132(output in hex format: 0xAAAABBCC), where:
133 AAAA - major revision
134 BB - minor revision
135 CC - bugfix revision
136
137The sysfs interface version changelog for the driver can be found at the
138end of this document. Changes to the sysfs interface done by the kernel
139subsystems are not documented here, nor are they tracked by this
140attribute.
141
142Changes to the thinkpad-acpi sysfs interface are only considered
143non-experimental when they are submitted to Linux mainline, at which
144point the changes in this interface are documented and interface_version
145may be updated. If you are using any thinkpad-acpi features not yet
146sent to mainline for merging, you do so on your own risk: these features
147may disappear, or be implemented in a different and incompatible way by
148the time they are merged in Linux mainline.
149
150Changes that are backwards-compatible by nature (e.g. the addition of
151attributes that do not change the way the other attributes work) do not
152always warrant an update of interface_version. Therefore, one must
153expect that an attribute might not be there, and deal with it properly
154(an attribute not being there *is* a valid way to make it clear that a
155feature is not available in sysfs).
156
157Hot keys
158--------
159
160procfs: /proc/acpi/ibm/hotkey
161sysfs device attribute: hotkey_*
162
163In a ThinkPad, the ACPI HKEY handler is responsible for comunicating
164some important events and also keyboard hot key presses to the operating
165system. Enabling the hotkey functionality of thinkpad-acpi signals the
166firmware that such a driver is present, and modifies how the ThinkPad
167firmware will behave in many situations.
168
169The driver enables the hot key feature automatically when loaded. The
170feature can later be disabled and enabled back at runtime. The driver
171will also restore the hot key feature to its previous state and mask
172when it is unloaded.
173
174When the hotkey feature is enabled and the hot key mask is set (see
175below), the driver will report HKEY events in the following format:
176
177 ibm/hotkey HKEY 00000080 0000xxxx
178
179Some of these events refer to hot key presses, but not all.
180
181The driver will generate events over the input layer for hot keys and
182radio switches, and over the ACPI netlink layer for other events. The
183input layer support accepts the standard IOCTLs to remap the keycodes
184assigned to each hot key.
185
186The hot key bit mask allows some control over which hot keys generate
187events. If a key is "masked" (bit set to 0 in the mask), the firmware
188will handle it. If it is "unmasked", it signals the firmware that
189thinkpad-acpi would prefer to handle it, if the firmware would be so
190kind to allow it (and it often doesn't!).
191
192Not all bits in the mask can be modified. Not all bits that can be
193modified do anything. Not all hot keys can be individually controlled
194by the mask. Some models do not support the mask at all, and in those
195models, hot keys cannot be controlled individually. The behaviour of
196the mask is, therefore, higly dependent on the ThinkPad model.
197
198Note that unmasking some keys prevents their default behavior. For
199example, if Fn+F5 is unmasked, that key will no longer enable/disable
200Bluetooth by itself.
201
202Note also that not all Fn key combinations are supported through ACPI.
203For example, on the X40, the brightness, volume and "Access IBM" buttons
204do not generate ACPI events even with this driver. They *can* be used
205through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
206
207procfs notes:
208
209The following commands can be written to the /proc/acpi/ibm/hotkey file:
210
211 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
212 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
213 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
214 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
215 ... any other 8-hex-digit mask ...
216 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
217
218The procfs interface does not support NVRAM polling control. So as to
219maintain maximum bug-to-bug compatibility, it does not report any masks,
220nor does it allow one to manipulate the hot key mask when the firmware
221does not support masks at all, even if NVRAM polling is in use.
222
223sysfs notes:
224
225 hotkey_bios_enabled:
226 Returns the status of the hot keys feature when
227 thinkpad-acpi was loaded. Upon module unload, the hot
228 key feature status will be restored to this value.
229
230 0: hot keys were disabled
231 1: hot keys were enabled (unusual)
232
233 hotkey_bios_mask:
234 Returns the hot keys mask when thinkpad-acpi was loaded.
235 Upon module unload, the hot keys mask will be restored
236 to this value.
237
238 hotkey_enable:
239 Enables/disables the hot keys feature in the ACPI
240 firmware, and reports current status of the hot keys
241 feature. Has no effect on the NVRAM hot key polling
242 functionality.
243
244 0: disables the hot keys feature / feature disabled
245 1: enables the hot keys feature / feature enabled
246
247 hotkey_mask:
248 bit mask to enable driver-handling (and depending on
249 the firmware, ACPI event generation) for each hot key
250 (see above). Returns the current status of the hot keys
251 mask, and allows one to modify it.
252
253 Note: when NVRAM polling is active, the firmware mask
254 will be different from the value returned by
255 hotkey_mask. The driver will retain enabled bits for
256 hotkeys that are under NVRAM polling even if the
257 firmware refuses them, and will not set these bits on
258 the firmware hot key mask.
259
260 hotkey_all_mask:
261 bit mask that should enable event reporting for all
262 supported hot keys, when echoed to hotkey_mask above.
263 Unless you know which events need to be handled
264 passively (because the firmware *will* handle them
265 anyway), do *not* use hotkey_all_mask. Use
266 hotkey_recommended_mask, instead. You have been warned.
267
268 hotkey_recommended_mask:
269 bit mask that should enable event reporting for all
270 supported hot keys, except those which are always
271 handled by the firmware anyway. Echo it to
272 hotkey_mask above, to use.
273
274 hotkey_source_mask:
275 bit mask that selects which hot keys will the driver
276 poll the NVRAM for. This is auto-detected by the driver
277 based on the capabilities reported by the ACPI firmware,
278 but it can be overridden at runtime.
279
280 Hot keys whose bits are set in both hotkey_source_mask
281 and also on hotkey_mask are polled for in NVRAM. Only a
282 few hot keys are available through CMOS NVRAM polling.
283
284 Warning: when in NVRAM mode, the volume up/down/mute
285 keys are synthesized according to changes in the mixer,
286 so you have to use volume up or volume down to unmute,
287 as per the ThinkPad volume mixer user interface. When
288 in ACPI event mode, volume up/down/mute are reported as
289 separate events, but this behaviour may be corrected in
290 future releases of this driver, in which case the
291 ThinkPad volume mixer user interface semanthics will be
292 enforced.
293
294 hotkey_poll_freq:
295 frequency in Hz for hot key polling. It must be between
296 0 and 25 Hz. Polling is only carried out when strictly
297 needed.
298
299 Setting hotkey_poll_freq to zero disables polling, and
300 will cause hot key presses that require NVRAM polling
301 to never be reported.
302
303 Setting hotkey_poll_freq too low will cause repeated
304 pressings of the same hot key to be misreported as a
305 single key press, or to not even be detected at all.
306 The recommended polling frequency is 10Hz.
307
308 hotkey_radio_sw:
309 if the ThinkPad has a hardware radio switch, this
310 attribute will read 0 if the switch is in the "radios
311 disabled" postition, and 1 if the switch is in the
312 "radios enabled" position.
313
314 This attribute has poll()/select() support.
315
316 hotkey_report_mode:
317 Returns the state of the procfs ACPI event report mode
318 filter for hot keys. If it is set to 1 (the default),
319 all hot key presses are reported both through the input
320 layer and also as ACPI events through procfs (but not
321 through netlink). If it is set to 2, hot key presses
322 are reported only through the input layer.
323
324 This attribute is read-only in kernels 2.6.23 or later,
325 and read-write on earlier kernels.
326
327 May return -EPERM (write access locked out by module
328 parameter) or -EACCES (read-only).
329
330 wakeup_reason:
331 Set to 1 if the system is waking up because the user
332 requested a bay ejection. Set to 2 if the system is
333 waking up because the user requested the system to
334 undock. Set to zero for normal wake-ups or wake-ups
335 due to unknown reasons.
336
337 This attribute has poll()/select() support.
338
339 wakeup_hotunplug_complete:
340 Set to 1 if the system was waken up because of an
341 undock or bay ejection request, and that request
342 was sucessfully completed. At this point, it might
343 be useful to send the system back to sleep, at the
344 user's choice. Refer to HKEY events 0x4003 and
345 0x3003, below.
346
347 This attribute has poll()/select() support.
348
349input layer notes:
350
351A Hot key is mapped to a single input layer EV_KEY event, possibly
352followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
353code. An EV_SYN event will always be generated to mark the end of the
354event block.
355
356Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
357used as a helper to remap keys, only. They are particularly useful when
358remapping KEY_UNKNOWN keys.
359
360The events are available in an input device, with the following id:
361
362 Bus: BUS_HOST
363 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
364 0x17aa (PCI_VENDOR_ID_LENOVO)
365 product: 0x5054 ("TP")
366 version: 0x4101
367
368The version will have its LSB incremented if the keymap changes in a
369backwards-compatible way. The MSB shall always be 0x41 for this input
370device. If the MSB is not 0x41, do not use the device as described in
371this section, as it is either something else (e.g. another input device
372exported by a thinkpad driver, such as HDAPS) or its functionality has
373been changed in a non-backwards compatible way.
374
375Adding other event types for other functionalities shall be considered a
376backwards-compatible change for this input device.
377
378Thinkpad-acpi Hot Key event map (version 0x4101):
379
380ACPI Scan
381event code Key Notes
382
3830x1001 0x00 FN+F1 -
3840x1002 0x01 FN+F2 IBM: battery (rare)
385 Lenovo: Screen lock
386
3870x1003 0x02 FN+F3 Many IBM models always report
388 this hot key, even with hot keys
389 disabled or with Fn+F3 masked
390 off
391 IBM: screen lock
392 Lenovo: battery
393
3940x1004 0x03 FN+F4 Sleep button (ACPI sleep button
395 semanthics, i.e. sleep-to-RAM).
396 It is always generate some kind
397 of event, either the hot key
398 event or a ACPI sleep button
399 event. The firmware may
400 refuse to generate further FN+F4
401 key presses until a S3 or S4 ACPI
402 sleep cycle is performed or some
403 time passes.
404
4050x1005 0x04 FN+F5 Radio. Enables/disables
406 the internal BlueTooth hardware
407 and W-WAN card if left in control
408 of the firmware. Does not affect
409 the WLAN card.
410 Should be used to turn on/off all
411 radios (bluetooth+W-WAN+WLAN),
412 really.
413
4140x1006 0x05 FN+F6 -
415
4160x1007 0x06 FN+F7 Video output cycle.
417 Do you feel lucky today?
418
4190x1008 0x07 FN+F8 IBM: toggle screen expand
420 Lenovo: configure ultranav
421
4220x1009 0x08 FN+F9 -
423 .. .. ..
4240x100B 0x0A FN+F11 -
425
4260x100C 0x0B FN+F12 Sleep to disk. You are always
427 supposed to handle it yourself,
428 either through the ACPI event,
429 or through a hotkey event.
430 The firmware may refuse to
431 generate further FN+F4 key
432 press events until a S3 or S4
433 ACPI sleep cycle is performed,
434 or some time passes.
435
4360x100D 0x0C FN+BACKSPACE -
4370x100E 0x0D FN+INSERT -
4380x100F 0x0E FN+DELETE -
439
4400x1010 0x0F FN+HOME Brightness up. This key is
441 always handled by the firmware
442 in IBM ThinkPads, even when
443 unmasked. Just leave it alone.
444 For Lenovo ThinkPads with a new
445 BIOS, it has to be handled either
446 by the ACPI OSI, or by userspace.
4470x1011 0x10 FN+END Brightness down. See brightness
448 up for details.
449
4500x1012 0x11 FN+PGUP Thinklight toggle. This key is
451 always handled by the firmware,
452 even when unmasked.
453
4540x1013 0x12 FN+PGDOWN -
455
4560x1014 0x13 FN+SPACE Zoom key
457
4580x1015 0x14 VOLUME UP Internal mixer volume up. This
459 key is always handled by the
460 firmware, even when unmasked.
461 NOTE: Lenovo seems to be changing
462 this.
4630x1016 0x15 VOLUME DOWN Internal mixer volume up. This
464 key is always handled by the
465 firmware, even when unmasked.
466 NOTE: Lenovo seems to be changing
467 this.
4680x1017 0x16 MUTE Mute internal mixer. This
469 key is always handled by the
470 firmware, even when unmasked.
471
4720x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
473
4740x1019 0x18 unknown
475.. .. ..
4760x1020 0x1F unknown
477
478The ThinkPad firmware does not allow one to differentiate when most hot
479keys are pressed or released (either that, or we don't know how to, yet).
480For these keys, the driver generates a set of events for a key press and
481immediately issues the same set of events for a key release. It is
482unknown by the driver if the ThinkPad firmware triggered these events on
483hot key press or release, but the firmware will do it for either one, not
484both.
485
486If a key is mapped to KEY_RESERVED, it generates no input events at all.
487If a key is mapped to KEY_UNKNOWN, it generates an input event that
488includes an scan code. If a key is mapped to anything else, it will
489generate input device EV_KEY events.
490
491Non hot-key ACPI HKEY event map:
4920x5001 Lid closed
4930x5002 Lid opened
4940x7000 Radio Switch may have changed state
495
496The above events are not propagated by the driver, except for legacy
497compatibility purposes when hotkey_report_mode is set to 1.
498
4990x2304 System is waking up from suspend to undock
5000x2305 System is waking up from suspend to eject bay
5010x2404 System is waking up from hibernation to undock
5020x2405 System is waking up from hibernation to eject bay
503
504The above events are never propagated by the driver.
505
5060x3003 Bay ejection (see 0x2x05) complete, can sleep again
5070x4003 Undocked (see 0x2x04), can sleep again
5080x5009 Tablet swivel: switched to tablet mode
5090x500A Tablet swivel: switched to normal mode
5100x500B Tablet pen insterted into its storage bay
5110x500C Tablet pen removed from its storage bay
5120x5010 Brightness level changed (newer Lenovo BIOSes)
513
514The above events are propagated by the driver.
515
516Compatibility notes:
517
518ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
519supported the input layer, and sent events over the procfs ACPI event
520interface.
521
522To avoid sending duplicate events over the input layer and the ACPI
523event interface, thinkpad-acpi 0.16 implements a module parameter
524(hotkey_report_mode), and also a sysfs device attribute with the same
525name.
526
527Make no mistake here: userspace is expected to switch to using the input
528layer interface of thinkpad-acpi, together with the ACPI netlink event
529interface in kernels 2.6.23 and later, or with the ACPI procfs event
530interface in kernels 2.6.22 and earlier.
531
532If no hotkey_report_mode module parameter is specified (or it is set to
533zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
534and earlier, also allows one to change the hotkey_report_mode through
535sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
536interface is available, hotkey_report_mode cannot be changed through
537sysfs (it is read-only).
538
539If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
540be changed later through sysfs (any writes will return -EPERM to signal
541that hotkey_report_mode was locked. On 2.6.23 and later, where
542hotkey_report_mode cannot be changed at all, writes will return -EACES).
543
544hotkey_report_mode set to 1 makes the driver export through the procfs
545ACPI event interface all hot key presses (which are *also* sent to the
546input layer). This is a legacy compatibility behaviour, and it is also
547the default mode of operation for the driver.
548
549hotkey_report_mode set to 2 makes the driver filter out the hot key
550presses from the procfs ACPI event interface, so these events will only
551be sent through the input layer. Userspace that has been updated to use
552the thinkpad-acpi input layer interface should set hotkey_report_mode to
5532.
554
555Hot key press events are never sent to the ACPI netlink event interface.
556Really up-to-date userspace under kernel 2.6.23 and later is to use the
557netlink interface and the input layer interface, and don't bother at all
558with hotkey_report_mode.
559
560
561Bluetooth
562---------
563
564procfs: /proc/acpi/ibm/bluetooth
565sysfs device attribute: bluetooth_enable
566
567This feature shows the presence and current state of a ThinkPad
568Bluetooth device in the internal ThinkPad CDC slot.
569
570Procfs notes:
571
572If Bluetooth is installed, the following commands can be used:
573
574 echo enable > /proc/acpi/ibm/bluetooth
575 echo disable > /proc/acpi/ibm/bluetooth
576
577Sysfs notes:
578
579 If the Bluetooth CDC card is installed, it can be enabled /
580 disabled through the "bluetooth_enable" thinkpad-acpi device
581 attribute, and its current status can also be queried.
582
583 enable:
584 0: disables Bluetooth / Bluetooth is disabled
585 1: enables Bluetooth / Bluetooth is enabled.
586
587 Note: this interface will be probably be superseeded by the
588 generic rfkill class, so it is NOT to be considered stable yet.
589
590Video output control -- /proc/acpi/ibm/video
591--------------------------------------------
592
593This feature allows control over the devices used for video output -
594LCD, CRT or DVI (if available). The following commands are available:
595
596 echo lcd_enable > /proc/acpi/ibm/video
597 echo lcd_disable > /proc/acpi/ibm/video
598 echo crt_enable > /proc/acpi/ibm/video
599 echo crt_disable > /proc/acpi/ibm/video
600 echo dvi_enable > /proc/acpi/ibm/video
601 echo dvi_disable > /proc/acpi/ibm/video
602 echo auto_enable > /proc/acpi/ibm/video
603 echo auto_disable > /proc/acpi/ibm/video
604 echo expand_toggle > /proc/acpi/ibm/video
605 echo video_switch > /proc/acpi/ibm/video
606
607Each video output device can be enabled or disabled individually.
608Reading /proc/acpi/ibm/video shows the status of each device.
609
610Automatic video switching can be enabled or disabled. When automatic
611video switching is enabled, certain events (e.g. opening the lid,
612docking or undocking) cause the video output device to change
613automatically. While this can be useful, it also causes flickering
614and, on the X40, video corruption. By disabling automatic switching,
615the flickering or video corruption can be avoided.
616
617The video_switch command cycles through the available video outputs
618(it simulates the behavior of Fn-F7).
619
620Video expansion can be toggled through this feature. This controls
621whether the display is expanded to fill the entire LCD screen when a
622mode with less than full resolution is used. Note that the current
623video expansion status cannot be determined through this feature.
624
625Note that on many models (particularly those using Radeon graphics
626chips) the X driver configures the video card in a way which prevents
627Fn-F7 from working. This also disables the video output switching
628features of this driver, as it uses the same ACPI methods as
629Fn-F7. Video switching on the console should still work.
630
631UPDATE: There's now a patch for the X.org Radeon driver which
632addresses this issue. Some people are reporting success with the patch
633while others are still having problems. For more information:
634
635https://bugs.freedesktop.org/show_bug.cgi?id=2000
636
637ThinkLight control -- /proc/acpi/ibm/light
638------------------------------------------
639
640The current status of the ThinkLight can be found in this file. A few
641models which do not make the status available will show it as
642"unknown". The available commands are:
643
644 echo on > /proc/acpi/ibm/light
645 echo off > /proc/acpi/ibm/light
646
647Docking / undocking -- /proc/acpi/ibm/dock
648------------------------------------------
649
650Docking and undocking (e.g. with the X4 UltraBase) requires some
651actions to be taken by the operating system to safely make or break
652the electrical connections with the dock.
653
654The docking feature of this driver generates the following ACPI events:
655
656 ibm/dock GDCK 00000003 00000001 -- eject request
657 ibm/dock GDCK 00000003 00000002 -- undocked
658 ibm/dock GDCK 00000000 00000003 -- docked
659
660NOTE: These events will only be generated if the laptop was docked
661when originally booted. This is due to the current lack of support for
662hot plugging of devices in the Linux ACPI framework. If the laptop was
663booted while not in the dock, the following message is shown in the
664logs:
665
666 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
667
668In this case, no dock-related events are generated but the dock and
669undock commands described below still work. They can be executed
670manually or triggered by Fn key combinations (see the example acpid
671configuration files included in the driver tarball package available
672on the web site).
673
674When the eject request button on the dock is pressed, the first event
675above is generated. The handler for this event should issue the
676following command:
677
678 echo undock > /proc/acpi/ibm/dock
679
680After the LED on the dock goes off, it is safe to eject the laptop.
681Note: if you pressed this key by mistake, go ahead and eject the
682laptop, then dock it back in. Otherwise, the dock may not function as
683expected.
684
685When the laptop is docked, the third event above is generated. The
686handler for this event should issue the following command to fully
687enable the dock:
688
689 echo dock > /proc/acpi/ibm/dock
690
691The contents of the /proc/acpi/ibm/dock file shows the current status
692of the dock, as provided by the ACPI framework.
693
694The docking support in this driver does not take care of enabling or
695disabling any other devices you may have attached to the dock. For
696example, a CD drive plugged into the UltraBase needs to be disabled or
697enabled separately. See the provided example acpid configuration files
698for how this can be accomplished.
699
700There is no support yet for PCI devices that may be attached to a
701docking station, e.g. in the ThinkPad Dock II. The driver currently
702does not recognize, enable or disable such devices. This means that
703the only docking stations currently supported are the X-series
704UltraBase docks and "dumb" port replicators like the Mini Dock (the
705latter don't need any ACPI support, actually).
706
707UltraBay eject -- /proc/acpi/ibm/bay
708------------------------------------
709
710Inserting or ejecting an UltraBay device requires some actions to be
711taken by the operating system to safely make or break the electrical
712connections with the device.
713
714This feature generates the following ACPI events:
715
716 ibm/bay MSTR 00000003 00000000 -- eject request
717 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
718
719NOTE: These events will only be generated if the UltraBay was present
720when the laptop was originally booted (on the X series, the UltraBay
721is in the dock, so it may not be present if the laptop was undocked).
722This is due to the current lack of support for hot plugging of devices
723in the Linux ACPI framework. If the laptop was booted without the
724UltraBay, the following message is shown in the logs:
725
726 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
727
728In this case, no bay-related events are generated but the eject
729command described below still works. It can be executed manually or
730triggered by a hot key combination.
731
732Sliding the eject lever generates the first event shown above. The
733handler for this event should take whatever actions are necessary to
734shut down the device in the UltraBay (e.g. call idectl), then issue
735the following command:
736
737 echo eject > /proc/acpi/ibm/bay
738
739After the LED on the UltraBay goes off, it is safe to pull out the
740device.
741
742When the eject lever is inserted, the second event above is
743generated. The handler for this event should take whatever actions are
744necessary to enable the UltraBay device (e.g. call idectl).
745
746The contents of the /proc/acpi/ibm/bay file shows the current status
747of the UltraBay, as provided by the ACPI framework.
748
749EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
750this feature, you need to supply the experimental=1 parameter when
751loading the module):
752
753These models do not have a button near the UltraBay device to request
754a hot eject but rather require the laptop to be put to sleep
755(suspend-to-ram) before the bay device is ejected or inserted).
756The sequence of steps to eject the device is as follows:
757
758 echo eject > /proc/acpi/ibm/bay
759 put the ThinkPad to sleep
760 remove the drive
761 resume from sleep
762 cat /proc/acpi/ibm/bay should show that the drive was removed
763
764On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
765supported. Use "eject2" instead of "eject" for the second bay.
766
767Note: the UltraBay eject support on the 600e/x, A22p and A3x is
768EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
769
770CMOS control
771------------
772
773procfs: /proc/acpi/ibm/cmos
774sysfs device attribute: cmos_command
775
776This feature is mostly used internally by the ACPI firmware to keep the legacy
777CMOS NVRAM bits in sync with the current machine state, and to record this
778state so that the ThinkPad will retain such settings across reboots.
779
780Some of these commands actually perform actions in some ThinkPad models, but
781this is expected to disappear more and more in newer models. As an example, in
782a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
783real, but commands 0 to 2 don't control the mixer anymore (they have been
784phased out) and just update the NVRAM.
785
786The range of valid cmos command numbers is 0 to 21, but not all have an
787effect and the behavior varies from model to model. Here is the behavior
788on the X40 (tpb is the ThinkPad Buttons utility):
789
790 0 - Related to "Volume down" key press
791 1 - Related to "Volume up" key press
792 2 - Related to "Mute on" key press
793 3 - Related to "Access IBM" key press
794 4 - Related to "LCD brightness up" key pess
795 5 - Related to "LCD brightness down" key press
796 11 - Related to "toggle screen expansion" key press/function
797 12 - Related to "ThinkLight on"
798 13 - Related to "ThinkLight off"
799 14 - Related to "ThinkLight" key press (toggle thinklight)
800
801The cmos command interface is prone to firmware split-brain problems, as
802in newer ThinkPads it is just a compatibility layer. Do not use it, it is
803exported just as a debug tool.
804
805LED control -- /proc/acpi/ibm/led
806---------------------------------
807
808Some of the LED indicators can be controlled through this feature. The
809available commands are:
810
811 echo '<led number> on' >/proc/acpi/ibm/led
812 echo '<led number> off' >/proc/acpi/ibm/led
813 echo '<led number> blink' >/proc/acpi/ibm/led
814
815The <led number> range is 0 to 7. The set of LEDs that can be
816controlled varies from model to model. Here is the mapping on the X40:
817
818 0 - power
819 1 - battery (orange)
820 2 - battery (green)
821 3 - UltraBase
822 4 - UltraBay
823 7 - standby
824
825All of the above can be turned on and off and can be made to blink.
826
827ACPI sounds -- /proc/acpi/ibm/beep
828----------------------------------
829
830The BEEP method is used internally by the ACPI firmware to provide
831audible alerts in various situations. This feature allows the same
832sounds to be triggered manually.
833
834The commands are non-negative integer numbers:
835
836 echo <number> >/proc/acpi/ibm/beep
837
838The valid <number> range is 0 to 17. Not all numbers trigger sounds
839and the sounds vary from model to model. Here is the behavior on the
840X40:
841
842 0 - stop a sound in progress (but use 17 to stop 16)
843 2 - two beeps, pause, third beep ("low battery")
844 3 - single beep
845 4 - high, followed by low-pitched beep ("unable")
846 5 - single beep
847 6 - very high, followed by high-pitched beep ("AC/DC")
848 7 - high-pitched beep
849 9 - three short beeps
850 10 - very long beep
851 12 - low-pitched beep
852 15 - three high-pitched beeps repeating constantly, stop with 0
853 16 - one medium-pitched beep repeating constantly, stop with 17
854 17 - stop 16
855
856Temperature sensors
857-------------------
858
859procfs: /proc/acpi/ibm/thermal
860sysfs device attributes: (hwmon "thinkpad") temp*_input
861
862Most ThinkPads include six or more separate temperature sensors but only
863expose the CPU temperature through the standard ACPI methods. This
864feature shows readings from up to eight different sensors on older
865ThinkPads, and up to sixteen different sensors on newer ThinkPads.
866
867For example, on the X40, a typical output may be:
868temperatures: 42 42 45 41 36 -128 33 -128
869
870On the T43/p, a typical output may be:
871temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
872
873The mapping of thermal sensors to physical locations varies depending on
874system-board model (and thus, on ThinkPad model).
875
876http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
877tries to track down these locations for various models.
878
879Most (newer?) models seem to follow this pattern:
880
8811: CPU
8822: (depends on model)
8833: (depends on model)
8844: GPU
8855: Main battery: main sensor
8866: Bay battery: main sensor
8877: Main battery: secondary sensor
8888: Bay battery: secondary sensor
8899-15: (depends on model)
890
891For the R51 (source: Thomas Gruber):
8922: Mini-PCI
8933: Internal HDD
894
895For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
896http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
8972: System board, left side (near PCMCIA slot), reported as HDAPS temp
8983: PCMCIA slot
8999: MCH (northbridge) to DRAM Bus
90010: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
901 card, under touchpad
90211: Power regulator, underside of system board, below F2 key
903
904The A31 has a very atypical layout for the thermal sensors
905(source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
9061: CPU
9072: Main Battery: main sensor
9083: Power Converter
9094: Bay Battery: main sensor
9105: MCH (northbridge)
9116: PCMCIA/ambient
9127: Main Battery: secondary sensor
9138: Bay Battery: secondary sensor
914
915
916Procfs notes:
917 Readings from sensors that are not available return -128.
918 No commands can be written to this file.
919
920Sysfs notes:
921 Sensors that are not available return the ENXIO error. This
922 status may change at runtime, as there are hotplug thermal
923 sensors, like those inside the batteries and docks.
924
925 thinkpad-acpi thermal sensors are reported through the hwmon
926 subsystem, and follow all of the hwmon guidelines at
927 Documentation/hwmon.
928
929
930EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
931------------------------------------------------------------------------
932
933This feature is marked EXPERIMENTAL because the implementation
934directly accesses hardware registers and may not work as expected. USE
935WITH CAUTION! To use this feature, you need to supply the
936experimental=1 parameter when loading the module.
937
938This feature dumps the values of 256 embedded controller
939registers. Values which have changed since the last time the registers
940were dumped are marked with a star:
941
942[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
943EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
944EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
945EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
946EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
947EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
948EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
949EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
950EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
951EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
952EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
953EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
954EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
955EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
956EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
957EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
958EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
959EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
960
961This feature can be used to determine the register holding the fan
962speed on some models. To do that, do the following:
963
964 - make sure the battery is fully charged
965 - make sure the fan is running
966 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
967
968The first step makes sure various charging-related values don't
969vary. The second ensures that the fan-related values do vary, since
970the fan speed fluctuates a bit. The third will (hopefully) mark the
971fan register with a star:
972
973[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
974EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
975EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
976EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
977EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
978EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
979EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
980EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
981EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
982EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
983EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
984EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
985EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
986EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
987EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
988EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
989EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
990EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
991
992Another set of values that varies often is the temperature
993readings. Since temperatures don't change vary fast, you can take
994several quick dumps to eliminate them.
995
996You can use a similar method to figure out the meaning of other
997embedded controller registers - e.g. make sure nothing else changes
998except the charging or discharging battery to determine which
999registers contain the current battery capacity, etc. If you experiment
1000with this, do send me your results (including some complete dumps with
1001a description of the conditions when they were taken.)
1002
1003LCD brightness control
1004----------------------
1005
1006procfs: /proc/acpi/ibm/brightness
1007sysfs backlight device "thinkpad_screen"
1008
1009This feature allows software control of the LCD brightness on ThinkPad
1010models which don't have a hardware brightness slider.
1011
1012It has some limitations: the LCD backlight cannot be actually turned on or
1013off by this interface, and in many ThinkPad models, the "dim while on
1014battery" functionality will be enabled by the BIOS when this interface is
1015used, and cannot be controlled.
1016
1017On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
1018has eight brightness levels, ranging from 0 to 7. Some of the levels
1019may not be distinct. Later Lenovo models that implement the ACPI
1020display backlight brightness control methods have 16 levels, ranging
1021from 0 to 15.
1022
1023There are two interfaces to the firmware for direct brightness control,
1024EC and CMOS. To select which one should be used, use the
1025brightness_mode module parameter: brightness_mode=1 selects EC mode,
1026brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
1027and CMOS. The driver tries to autodetect which interface to use.
1028
1029When display backlight brightness controls are available through the
1030standard ACPI interface, it is best to use it instead of this direct
1031ThinkPad-specific interface. The driver will disable its native
1032backlight brightness control interface if it detects that the standard
1033ACPI interface is available in the ThinkPad.
1034
1035The brightness_enable module parameter can be used to control whether
1036the LCD brightness control feature will be enabled when available.
1037brightness_enable=0 forces it to be disabled. brightness_enable=1
1038forces it to be enabled when available, even if the standard ACPI
1039interface is also available.
1040
1041Procfs notes:
1042
1043 The available commands are:
1044
1045 echo up >/proc/acpi/ibm/brightness
1046 echo down >/proc/acpi/ibm/brightness
1047 echo 'level <level>' >/proc/acpi/ibm/brightness
1048
1049Sysfs notes:
1050
1051The interface is implemented through the backlight sysfs class, which is
1052poorly documented at this time.
1053
1054Locate the thinkpad_screen device under /sys/class/backlight, and inside
1055it there will be the following attributes:
1056
1057 max_brightness:
1058 Reads the maximum brightness the hardware can be set to.
1059 The minimum is always zero.
1060
1061 actual_brightness:
1062 Reads what brightness the screen is set to at this instant.
1063
1064 brightness:
1065 Writes request the driver to change brightness to the
1066 given value. Reads will tell you what brightness the
1067 driver is trying to set the display to when "power" is set
1068 to zero and the display has not been dimmed by a kernel
1069 power management event.
1070
1071 power:
1072 power management mode, where 0 is "display on", and 1 to 3
1073 will dim the display backlight to brightness level 0
1074 because thinkpad-acpi cannot really turn the backlight
1075 off. Kernel power management events can temporarily
1076 increase the current power management level, i.e. they can
1077 dim the display.
1078
1079
1080Volume control -- /proc/acpi/ibm/volume
1081---------------------------------------
1082
1083This feature allows volume control on ThinkPad models which don't have
1084a hardware volume knob. The available commands are:
1085
1086 echo up >/proc/acpi/ibm/volume
1087 echo down >/proc/acpi/ibm/volume
1088 echo mute >/proc/acpi/ibm/volume
1089 echo 'level <level>' >/proc/acpi/ibm/volume
1090
1091The <level> number range is 0 to 15 although not all of them may be
1092distinct. The unmute the volume after the mute command, use either the
1093up or down command (the level command will not unmute the volume).
1094The current volume level and mute state is shown in the file.
1095
1096Fan control and monitoring: fan speed, fan enable/disable
1097---------------------------------------------------------
1098
1099procfs: /proc/acpi/ibm/fan
1100sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1101 pwm1_enable
1102sysfs hwmon driver attributes: fan_watchdog
1103
1104NOTE NOTE NOTE: fan control operations are disabled by default for
1105safety reasons. To enable them, the module parameter "fan_control=1"
1106must be given to thinkpad-acpi.
1107
1108This feature attempts to show the current fan speed, control mode and
1109other fan data that might be available. The speed is read directly
1110from the hardware registers of the embedded controller. This is known
1111to work on later R, T, X and Z series ThinkPads but may show a bogus
1112value on other models.
1113
1114Fan levels:
1115
1116Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1117stops the fan. The higher the level, the higher the fan speed, although
1118adjacent levels often map to the same fan speed. 7 is the highest
1119level, where the fan reaches the maximum recommended speed.
1120
1121Level "auto" means the EC changes the fan level according to some
1122internal algorithm, usually based on readings from the thermal sensors.
1123
1124There is also a "full-speed" level, also known as "disengaged" level.
1125In this level, the EC disables the speed-locked closed-loop fan control,
1126and drives the fan as fast as it can go, which might exceed hardware
1127limits, so use this level with caution.
1128
1129The fan usually ramps up or down slowly from one speed to another, and
1130it is normal for the EC to take several seconds to react to fan
1131commands. The full-speed level may take up to two minutes to ramp up to
1132maximum speed, and in some ThinkPads, the tachometer readings go stale
1133while the EC is transitioning to the full-speed level.
1134
1135WARNING WARNING WARNING: do not leave the fan disabled unless you are
1136monitoring all of the temperature sensor readings and you are ready to
1137enable it if necessary to avoid overheating.
1138
1139An enabled fan in level "auto" may stop spinning if the EC decides the
1140ThinkPad is cool enough and doesn't need the extra airflow. This is
1141normal, and the EC will spin the fan up if the various thermal readings
1142rise too much.
1143
1144On the X40, this seems to depend on the CPU and HDD temperatures.
1145Specifically, the fan is turned on when either the CPU temperature
1146climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1147fan is turned off when the CPU temperature drops to 49 degrees and the
1148HDD temperature drops to 41 degrees. These thresholds cannot
1149currently be controlled.
1150
1151The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1152certain conditions are met. It will override any fan programming done
1153through thinkpad-acpi.
1154
1155The thinkpad-acpi kernel driver can be programmed to revert the fan
1156level to a safe setting if userspace does not issue one of the procfs
1157fan commands: "enable", "disable", "level" or "watchdog", or if there
1158are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1159set to 1, manual mode) within a configurable amount of time of up to
1160120 seconds. This functionality is called fan safety watchdog.
1161
1162Note that the watchdog timer stops after it enables the fan. It will be
1163rearmed again automatically (using the same interval) when one of the
1164above mentioned fan commands is received. The fan watchdog is,
1165therefore, not suitable to protect against fan mode changes made through
1166means other than the "enable", "disable", and "level" procfs fan
1167commands, or the hwmon fan control sysfs interface.
1168
1169Procfs notes:
1170
1171The fan may be enabled or disabled with the following commands:
1172
1173 echo enable >/proc/acpi/ibm/fan
1174 echo disable >/proc/acpi/ibm/fan
1175
1176Placing a fan on level 0 is the same as disabling it. Enabling a fan
1177will try to place it in a safe level if it is too slow or disabled.
1178
1179The fan level can be controlled with the command:
1180
1181 echo 'level <level>' > /proc/acpi/ibm/fan
1182
1183Where <level> is an integer from 0 to 7, or one of the words "auto" or
1184"full-speed" (without the quotes). Not all ThinkPads support the "auto"
1185and "full-speed" levels. The driver accepts "disengaged" as an alias for
1186"full-speed", and reports it as "disengaged" for backwards
1187compatibility.
1188
1189On the X31 and X40 (and ONLY on those models), the fan speed can be
1190controlled to a certain degree. Once the fan is running, it can be
1191forced to run faster or slower with the following command:
1192
1193 echo 'speed <speed>' > /proc/acpi/ibm/fan
1194
1195The sustainable range of fan speeds on the X40 appears to be from about
11963700 to about 7350. Values outside this range either do not have any
1197effect or the fan speed eventually settles somewhere in that range. The
1198fan cannot be stopped or started with this command. This functionality
1199is incomplete, and not available through the sysfs interface.
1200
1201To program the safety watchdog, use the "watchdog" command.
1202
1203 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1204
1205If you want to disable the watchdog, use 0 as the interval.
1206
1207Sysfs notes:
1208
1209The sysfs interface follows the hwmon subsystem guidelines for the most
1210part, and the exception is the fan safety watchdog.
1211
1212Writes to any of the sysfs attributes may return the EINVAL error if
1213that operation is not supported in a given ThinkPad or if the parameter
1214is out-of-bounds, and EPERM if it is forbidden. They may also return
1215EINTR (interrupted system call), and EIO (I/O error while trying to talk
1216to the firmware).
1217
1218Features not yet implemented by the driver return ENOSYS.
1219
1220hwmon device attribute pwm1_enable:
1221 0: PWM offline (fan is set to full-speed mode)
1222 1: Manual PWM control (use pwm1 to set fan level)
1223 2: Hardware PWM control (EC "auto" mode)
1224 3: reserved (Software PWM control, not implemented yet)
1225
1226 Modes 0 and 2 are not supported by all ThinkPads, and the
1227 driver is not always able to detect this. If it does know a
1228 mode is unsupported, it will return -EINVAL.
1229
1230hwmon device attribute pwm1:
1231 Fan level, scaled from the firmware values of 0-7 to the hwmon
1232 scale of 0-255. 0 means fan stopped, 255 means highest normal
1233 speed (level 7).
1234
1235 This attribute only commands the fan if pmw1_enable is set to 1
1236 (manual PWM control).
1237
1238hwmon device attribute fan1_input:
1239 Fan tachometer reading, in RPM. May go stale on certain
1240 ThinkPads while the EC transitions the PWM to offline mode,
1241 which can take up to two minutes. May return rubbish on older
1242 ThinkPads.
1243
1244hwmon driver attribute fan_watchdog:
1245 Fan safety watchdog timer interval, in seconds. Minimum is
1246 1 second, maximum is 120 seconds. 0 disables the watchdog.
1247
1248To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1249
1250To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1251with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1252would be the safest choice, though).
1253
1254
1255EXPERIMENTAL: WAN
1256-----------------
1257
1258procfs: /proc/acpi/ibm/wan
1259sysfs device attribute: wwan_enable
1260
1261This feature is marked EXPERIMENTAL because the implementation
1262directly accesses hardware registers and may not work as expected. USE
1263WITH CAUTION! To use this feature, you need to supply the
1264experimental=1 parameter when loading the module.
1265
1266This feature shows the presence and current state of a W-WAN (Sierra
1267Wireless EV-DO) device.
1268
1269It was tested on a Lenovo Thinkpad X60. It should probably work on other
1270Thinkpad models which come with this module installed.
1271
1272Procfs notes:
1273
1274If the W-WAN card is installed, the following commands can be used:
1275
1276 echo enable > /proc/acpi/ibm/wan
1277 echo disable > /proc/acpi/ibm/wan
1278
1279Sysfs notes:
1280
1281 If the W-WAN card is installed, it can be enabled /
1282 disabled through the "wwan_enable" thinkpad-acpi device
1283 attribute, and its current status can also be queried.
1284
1285 enable:
1286 0: disables WWAN card / WWAN card is disabled
1287 1: enables WWAN card / WWAN card is enabled.
1288
1289 Note: this interface will be probably be superseeded by the
1290 generic rfkill class, so it is NOT to be considered stable yet.
1291
1292Multiple Commands, Module Parameters
1293------------------------------------
1294
1295Multiple commands can be written to the proc files in one shot by
1296separating them with commas, for example:
1297
1298 echo enable,0xffff > /proc/acpi/ibm/hotkey
1299 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1300
1301Commands can also be specified when loading the thinkpad-acpi module,
1302for example:
1303
1304 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1305
1306Enabling debugging output
1307-------------------------
1308
1309The module takes a debug parameter which can be used to selectively
1310enable various classes of debugging output, for example:
1311
1312 modprobe ibm_acpi debug=0xffff
1313
1314will enable all debugging output classes. It takes a bitmask, so
1315to enable more than one output class, just add their values.
1316
1317 Debug bitmask Description
1318 0x0001 Initialization and probing
1319 0x0002 Removal
1320
1321There is also a kernel build option to enable more debugging
1322information, which may be necessary to debug driver problems.
1323
1324The level of debugging information output by the driver can be changed
1325at runtime through sysfs, using the driver attribute debug_level. The
1326attribute takes the same bitmask as the debug module parameter above.
1327
1328Force loading of module
1329-----------------------
1330
1331If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1332the module parameter force_load=1. Regardless of whether this works or
1333not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1334
1335
1336Sysfs interface changelog:
1337
13380x000100: Initial sysfs support, as a single platform driver and
1339 device.
13400x000200: Hot key support for 32 hot keys, and radio slider switch
1341 support.
13420x010000: Hot keys are now handled by default over the input
1343 layer, the radio switch generates input event EV_RADIO,
1344 and the driver enables hot key handling by default in
1345 the firmware.
1346
13470x020000: ABI fix: added a separate hwmon platform device and
1348 driver, which must be located by name (thinkpad)
1349 and the hwmon class for libsensors4 (lm-sensors 3)
1350 compatibility. Moved all hwmon attributes to this
1351 new platform device.
1352
13530x020100: Marker for thinkpad-acpi with hot key NVRAM polling
1354 support. If you must, use it to know you should not
1355 start an userspace NVRAM poller (allows to detect when
1356 NVRAM is compiled out by the user because it is
1357 unneeded/undesired in the first place).
13580x020101: Marker for thinkpad-acpi with hot key NVRAM polling
1359 and proper hotkey_mask semanthics (version 8 of the
1360 NVRAM polling patch). Some development snapshots of
1361 0.18 had an earlier version that did strange things
1362 to hotkey_mask.
1363
13640x020200: Add poll()/select() support to the following attributes:
1365 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason