Documentation/thinkpad-acpi.txt

   1                      ThinkPad ACPI Extras Driver
   2
   3                             Version 0.15
   4                            July 1st, 2007
   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
  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.
  15
  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.
  20
  21
  22 Status
  23 ------
  24
  25 The features currently supported are the following (see below for
  26 detailed 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
  44 A compatibility table by model and feature is maintained on the web
  45 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
  46 reports, especially if they add to or correct the compatibility table.
  47 Please 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
  56 Any other comments or patches are also more than welcome.
  57
  58
  59 Installation
  60 ------------
  61
  62 If you are compiling this driver as included in the Linux kernel
  63 sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
  64 enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
  65 thinkpad-specific bay functionality.
  66
  67 Features
  68 --------
  69
  70 The driver exports two different interfaces to userspace, which can be
  71 used to access the features it provides.  One is a legacy procfs-based
  72 interface, which will be removed at some time in the distant future.
  73 The other is a new sysfs-based interface which is not complete yet.
  74
  75 The procfs interface creates the /proc/acpi/ibm directory.  There is a
  76 file under that directory for each feature it supports.  The procfs
  77 interface is mostly frozen, and will change very little if at all: it
  78 will not be extended to add any new functionality in the driver, instead
  79 all new functionality will be implemented on the sysfs interface.
  80
  81 The sysfs interface tries to blend in the generic Linux sysfs subsystems
  82 and classes as much as possible.  Since some of these subsystems are not
  83 yet ready or stabilized, it is expected that this interface will change,
  84 and any and all userspace programs must deal with it.
  85
  86
  87 Notes about the sysfs interface:
  88
  89 Unlike what was done with the procfs interface, correctness when talking
  90 to the sysfs interfaces will be enforced, as will correctness in the
  91 thinkpad-acpi's implementation of sysfs interfaces.
  92
  93 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
  94 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
  95 maximum correctness, even if that means changing an interface in
  96 non-compatible ways.  As these interfaces mature both in the kernel and
  97 in thinkpad-acpi, such changes should become quite rare.
  98
  99 Applications interfacing to the thinkpad-acpi sysfs interfaces must
 100 follow all sysfs guidelines and correctly process all errors (the sysfs
 101 interface makes extensive use of errors).  File descriptors and open /
 102 close operations to the sysfs inodes must also be properly implemented.
 103
 104 The version of thinkpad-acpi's sysfs interface is exported by the driver
 105 as a driver attribute (see below).
 106
 107 Sysfs driver attributes are on the driver's sysfs attribute space,
 108 for 2.6.20 this is /sys/bus/platform/drivers/thinkpad-acpi/.
 109
 110 Sysfs device attributes are on the driver's sysfs attribute space,
 111 for 2.6.20 this is /sys/devices/platform/thinkpad-acpi/.
 112
 113 Driver version
 114 --------------
 115
 116 procfs: /proc/acpi/ibm/driver
 117 sysfs driver attribute: version
 118
 119 The driver name and version. No commands can be written to this file.
 120
 121 Sysfs interface version
 122 -----------------------
 123
 124 sysfs driver attribute: interface_version
 125
 126 Version of the thinkpad-acpi sysfs interface, as an unsigned long
 127 (output in hex format: 0xAAAABBCC), where:
 128         AAAA - major revision
 129         BB - minor revision
 130         CC - bugfix revision
 131
 132 The sysfs interface version changelog for the driver can be found at the
 133 end of this document.  Changes to the sysfs interface done by the kernel
 134 subsystems are not documented here, nor are they tracked by this
 135 attribute.
 136
 137 Changes to the thinkpad-acpi sysfs interface are only considered
 138 non-experimental when they are submitted to Linux mainline, at which
 139 point the changes in this interface are documented and interface_version
 140 may be updated.  If you are using any thinkpad-acpi features not yet
 141 sent to mainline for merging, you do so on your own risk: these features
 142 may disappear, or be implemented in a different and incompatible way by
 143 the time they are merged in Linux mainline.
 144
 145 Changes that are backwards-compatible by nature (e.g. the addition of
 146 attributes that do not change the way the other attributes work) do not
 147 always warrant an update of interface_version.  Therefore, one must
 148 expect that an attribute might not be there, and deal with it properly
 149 (an attribute not being there *is* a valid way to make it clear that a
 150 feature is not available in sysfs).
 151
 152 Hot keys
 153 --------
 154
 155 procfs: /proc/acpi/ibm/hotkey
 156 sysfs device attribute: hotkey_*
 157
 158 In a ThinkPad, the ACPI HKEY handler is responsible for comunicating
 159 some important events and also keyboard hot key presses to the operating
 160 system.  Enabling the hotkey functionality of thinkpad-acpi signals the
 161 firmware that such a driver is present, and modifies how the ThinkPad
 162 firmware will behave in many situations.
 163
 164 When the hotkey feature is enabled and the hot key mask is set (see
 165 below), the various hot keys either generate ACPI events in the
 166 following format:
 167
 168         ibm/hotkey HKEY 00000080 0000xxxx
 169
 170 or events over the input layer.  The input layer support accepts the
 171 standard IOCTLs to remap the keycodes assigned to each hotkey.
 172
 173 When the input device is open, the driver will suppress any ACPI hot key
 174 events that get translated into a meaningful input layer event, in order
 175 to avoid sending duplicate events to userspace.  Hot keys that are
 176 mapped to KEY_RESERVED in the keymap are not translated, and will always
 177 generate an ACPI ibm/hotkey HKEY event, and no input layer events.
 178
 179 The hot key bit mask allows some control over which hot keys generate
 180 events.  If a key is "masked" (bit set to 0 in the mask), the firmware
 181 will handle it.  If it is "unmasked", it signals the firmware that
 182 thinkpad-acpi would prefer to handle it, if the firmware would be so
 183 kind to allow it (and it often doesn't!).
 184
 185 Not all bits in the mask can be modified.  Not all bits that can be
 186 modified do anything.  Not all hot keys can be individually controlled
 187 by the mask.  Some models do not support the mask at all, and in those
 188 models, hot keys cannot be controlled individually.  The behaviour of
 189 the mask is, therefore, higly dependent on the ThinkPad model.
 190
 191 Note that unmasking some keys prevents their default behavior.  For
 192 example, if Fn+F5 is unmasked, that key will no longer enable/disable
 193 Bluetooth by itself.
 194
 195 Note also that not all Fn key combinations are supported through ACPI.
 196 For example, on the X40, the brightness, volume and "Access IBM" buttons
 197 do not generate ACPI events even with this driver.  They *can* be used
 198 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
 199
 200 procfs notes:
 201
 202 The following commands can be written to the /proc/acpi/ibm/hotkey file:
 203
 204         echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
 205         echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
 206         echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
 207         echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
 208         ... any other 8-hex-digit mask ...
 209         echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
 210
 211 sysfs notes:
 212
 213         hotkey_bios_enabled:
 214                 Returns the status of the hot keys feature when
 215                 thinkpad-acpi was loaded.  Upon module unload, the hot
 216                 key feature status will be restored to this value.
 217
 218                 0: hot keys were disabled
 219                 1: hot keys were enabled (unusual)
 220
 221         hotkey_bios_mask:
 222                 Returns the hot keys mask when thinkpad-acpi was loaded.
 223                 Upon module unload, the hot keys mask will be restored
 224                 to this value.
 225
 226         hotkey_enable:
 227                 Enables/disables the hot keys feature, and reports
 228                 current status of the hot keys feature.
 229
 230                 0: disables the hot keys feature / feature disabled
 231                 1: enables the hot keys feature / feature enabled
 232
 233         hotkey_mask:
 234                 bit mask to enable driver-handling and ACPI event
 235                 generation for each hot key (see above).  Returns the
 236                 current status of the hot keys mask, and allows one to
 237                 modify it.
 238
 239         hotkey_all_mask:
 240                 bit mask that should enable event reporting for all
 241                 supported hot keys, when echoed to hotkey_mask above.
 242                 Unless you know which events need to be handled
 243                 passively (because the firmware *will* handle them
 244                 anyway), do *not* use hotkey_all_mask.  Use
 245                 hotkey_recommended_mask, instead. You have been warned.
 246
 247         hotkey_recommended_mask:
 248                 bit mask that should enable event reporting for all
 249                 supported hot keys, except those which are always
 250                 handled by the firmware anyway.  Echo it to
 251                 hotkey_mask above, to use.
 252
 253         hotkey_radio_sw:
 254                 if the ThinkPad has a hardware radio switch, this
 255                 attribute will read 0 if the switch is in the "radios
 256                 disabled" postition, and 1 if the switch is in the
 257                 "radios enabled" position.
 258
 259 input layer notes:
 260
 261 A Hot key is mapped to a single input layer EV_KEY event, possibly
 262 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
 263 code.  An EV_SYN event will always be generated to mark the end of the
 264 event block.
 265
 266 Do not use the EV_MSC MSC_SCAN events to process keys.  They are to be
 267 used as a helper to remap keys, only.  They are particularly useful when
 268 remapping KEY_UNKNOWN keys.
 269
 270 The events are available in an input device, with the following id:
 271
 272         Bus:            BUS_HOST
 273         vendor:         0x1014 (PCI_VENDOR_ID_IBM)  or
 274                         0x17aa (PCI_VENDOR_ID_LENOVO)
 275         product:        0x5054 ("TP")
 276         version:        0x4101
 277
 278 The version will have its LSB incremented if the keymap changes in a
 279 backwards-compatible way.  The MSB shall always be 0x41 for this input
 280 device.  If the MSB is not 0x41, do not use the device as described in
 281 this section, as it is either something else (e.g. another input device
 282 exported by a thinkpad driver, such as HDAPS) or its functionality has
 283 been changed in a non-backwards compatible way.
 284
 285 Adding other event types for other functionalities shall be considered a
 286 backwards-compatible change for this input device.
 287
 288 Thinkpad-acpi Hot Key event map (version 0x4101):
 289
 290 ACPI    Scan
 291 event   code    Key             Notes
 292
 293 0x1001  0x00    FN+F1           -
 294 0x1002  0x01    FN+F2           IBM: battery (rare)
 295                                 Lenovo: Screen lock
 296
 297 0x1003  0x02    FN+F3           Many IBM models always report
 298                                 this hot key, even with hot keys
 299                                 disabled or with Fn+F3 masked
 300                                 off
 301                                 IBM: screen lock
 302                                 Lenovo: battery
 303
 304 0x1004  0x03    FN+F4           Sleep button (ACPI sleep button
 305                                 semanthics, i.e. sleep-to-RAM).
 306                                 It is always generate some kind
 307                                 of event, either the hot key
 308                                 event or a ACPI sleep button
 309                                 event. The firmware may
 310                                 refuse to generate further FN+F4
 311                                 key presses until a S3 or S4 ACPI
 312                                 sleep cycle is performed or some
 313                                 time passes.
 314
 315 0x1005  0x04    FN+F5           Radio.  Enables/disables
 316                                 the internal BlueTooth hardware
 317                                 and W-WAN card if left in control
 318                                 of the firmware.  Does not affect
 319                                 the WLAN card.
 320                                 Should be used to turn on/off all
 321                                 radios (bluetooth+W-WAN+WLAN),
 322                                 really.
 323
 324 0x1006  0x05    FN+F6           -
 325
 326 0x1007  0x06    FN+F7           Video output cycle.
 327                                 Do you feel lucky today?
 328
 329 0x1008  0x07    FN+F8           IBM: toggle screen expand
 330                                 Lenovo: configure ultranav
 331
 332 0x1009  0x08    FN+F9           -
 333         ..      ..              ..
 334 0x100B  0x0A    FN+F11          -
 335
 336 0x100C  0x0B    FN+F12          Sleep to disk.  You are always
 337                                 supposed to handle it yourself,
 338                                 either through the ACPI event,
 339                                 or through a hotkey event.
 340                                 The firmware may refuse to
 341                                 generate further FN+F4 key
 342                                 press events until a S3 or S4
 343                                 ACPI sleep cycle is performed,
 344                                 or some time passes.
 345
 346 0x100D  0x0C    FN+BACKSPACE    -
 347 0x100E  0x0D    FN+INSERT       -
 348 0x100F  0x0E    FN+DELETE       -
 349
 350 0x1010  0x0F    FN+HOME         Brightness up.  This key is
 351                                 always handled by the firmware
 352                                 in IBM ThinkPads, even when
 353                                 unmasked.  Just leave it alone.
 354                                 For Lenovo ThinkPads with a new
 355                                 BIOS, it has to be handled either
 356                                 by the ACPI OSI, or by userspace.
 357 0x1011  0x10    FN+END          Brightness down.  See brightness
 358                                 up for details.
 359
 360 0x1012  0x11    FN+PGUP         Thinklight toggle.  This key is
 361                                 always handled by the firmware,
 362                                 even when unmasked.
 363
 364 0x1013  0x12    FN+PGDOWN       -
 365
 366 0x1014  0x13    FN+SPACE        Zoom key
 367
 368 0x1015  0x14    VOLUME UP       Internal mixer volume up. This
 369                                 key is always handled by the
 370                                 firmware, even when unmasked.
 371                                 NOTE: Lenovo seems to be changing
 372                                 this.
 373 0x1016  0x15    VOLUME DOWN     Internal mixer volume up. This
 374                                 key is always handled by the
 375                                 firmware, even when unmasked.
 376                                 NOTE: Lenovo seems to be changing
 377                                 this.
 378 0x1017  0x16    MUTE            Mute internal mixer. This
 379                                 key is always handled by the
 380                                 firmware, even when unmasked.
 381
 382 0x1018  0x17    THINKPAD        Thinkpad/Access IBM/Lenovo key
 383
 384 0x1019  0x18    unknown
 385 ..      ..      ..
 386 0x1020  0x1F    unknown
 387
 388 The ThinkPad firmware does not allow one to differentiate when most hot
 389 keys are pressed or released (either that, or we don't know how to, yet).
 390 For these keys, the driver generates a set of events for a key press and
 391 immediately issues the same set of events for a key release.  It is
 392 unknown by the driver if the ThinkPad firmware triggered these events on
 393 hot key press or release, but the firmware will do it for either one, not
 394 both.
 395
 396 If a key is mapped to KEY_RESERVED, it generates no input events at all,
 397 and it may generate a legacy thinkpad-acpi ACPI hotkey event.
 398
 399 If a key is mapped to KEY_UNKNOWN, it generates an input event that
 400 includes an scan code, and it may also generate a legacy thinkpad-acpi
 401 ACPI hotkey event.
 402
 403 If a key is mapped to anything else, it will only generate legacy
 404 thinkpad-acpi ACPI hotkey events if nobody has opened the input device.
 405
 406 Non hot-key ACPI HKEY event map:
 407 0x5001          Lid closed
 408 0x5002          Lid opened
 409 0x7000          Radio Switch may have changed state
 410
 411
 412 Bluetooth
 413 ---------
 414
 415 procfs: /proc/acpi/ibm/bluetooth
 416 sysfs device attribute: bluetooth_enable
 417
 418 This feature shows the presence and current state of a ThinkPad
 419 Bluetooth device in the internal ThinkPad CDC slot.
 420
 421 Procfs notes:
 422
 423 If Bluetooth is installed, the following commands can be used:
 424
 425         echo enable > /proc/acpi/ibm/bluetooth
 426         echo disable > /proc/acpi/ibm/bluetooth
 427
 428 Sysfs notes:
 429
 430         If the Bluetooth CDC card is installed, it can be enabled /
 431         disabled through the "bluetooth_enable" thinkpad-acpi device
 432         attribute, and its current status can also be queried.
 433
 434         enable:
 435                 0: disables Bluetooth / Bluetooth is disabled
 436                 1: enables Bluetooth / Bluetooth is enabled.
 437
 438         Note: this interface will be probably be superseeded by the
 439         generic rfkill class, so it is NOT to be considered stable yet.
 440
 441 Video output control -- /proc/acpi/ibm/video
 442 --------------------------------------------
 443
 444 This feature allows control over the devices used for video output -
 445 LCD, CRT or DVI (if available). The following commands are available:
 446
 447         echo lcd_enable > /proc/acpi/ibm/video
 448         echo lcd_disable > /proc/acpi/ibm/video
 449         echo crt_enable > /proc/acpi/ibm/video
 450         echo crt_disable > /proc/acpi/ibm/video
 451         echo dvi_enable > /proc/acpi/ibm/video
 452         echo dvi_disable > /proc/acpi/ibm/video
 453         echo auto_enable > /proc/acpi/ibm/video
 454         echo auto_disable > /proc/acpi/ibm/video
 455         echo expand_toggle > /proc/acpi/ibm/video
 456         echo video_switch > /proc/acpi/ibm/video
 457
 458 Each video output device can be enabled or disabled individually.
 459 Reading /proc/acpi/ibm/video shows the status of each device.
 460
 461 Automatic video switching can be enabled or disabled.  When automatic
 462 video switching is enabled, certain events (e.g. opening the lid,
 463 docking or undocking) cause the video output device to change
 464 automatically. While this can be useful, it also causes flickering
 465 and, on the X40, video corruption. By disabling automatic switching,
 466 the flickering or video corruption can be avoided.
 467
 468 The video_switch command cycles through the available video outputs
 469 (it simulates the behavior of Fn-F7).
 470
 471 Video expansion can be toggled through this feature. This controls
 472 whether the display is expanded to fill the entire LCD screen when a
 473 mode with less than full resolution is used. Note that the current
 474 video expansion status cannot be determined through this feature.
 475
 476 Note that on many models (particularly those using Radeon graphics
 477 chips) the X driver configures the video card in a way which prevents
 478 Fn-F7 from working. This also disables the video output switching
 479 features of this driver, as it uses the same ACPI methods as
 480 Fn-F7. Video switching on the console should still work.
 481
 482 UPDATE: There's now a patch for the X.org Radeon driver which
 483 addresses this issue. Some people are reporting success with the patch
 484 while others are still having problems. For more information:
 485
 486 https://bugs.freedesktop.org/show_bug.cgi?id=2000
 487
 488 ThinkLight control -- /proc/acpi/ibm/light
 489 ------------------------------------------
 490
 491 The current status of the ThinkLight can be found in this file. A few
 492 models which do not make the status available will show it as
 493 "unknown". The available commands are:
 494
 495         echo on  > /proc/acpi/ibm/light
 496         echo off > /proc/acpi/ibm/light
 497
 498 Docking / undocking -- /proc/acpi/ibm/dock
 499 ------------------------------------------
 500
 501 Docking and undocking (e.g. with the X4 UltraBase) requires some
 502 actions to be taken by the operating system to safely make or break
 503 the electrical connections with the dock.
 504
 505 The docking feature of this driver generates the following ACPI events:
 506
 507         ibm/dock GDCK 00000003 00000001 -- eject request
 508         ibm/dock GDCK 00000003 00000002 -- undocked
 509         ibm/dock GDCK 00000000 00000003 -- docked
 510
 511 NOTE: These events will only be generated if the laptop was docked
 512 when originally booted. This is due to the current lack of support for
 513 hot plugging of devices in the Linux ACPI framework. If the laptop was
 514 booted while not in the dock, the following message is shown in the
 515 logs:
 516
 517         Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
 518
 519 In this case, no dock-related events are generated but the dock and
 520 undock commands described below still work. They can be executed
 521 manually or triggered by Fn key combinations (see the example acpid
 522 configuration files included in the driver tarball package available
 523 on the web site).
 524
 525 When the eject request button on the dock is pressed, the first event
 526 above is generated. The handler for this event should issue the
 527 following command:
 528
 529         echo undock > /proc/acpi/ibm/dock
 530
 531 After the LED on the dock goes off, it is safe to eject the laptop.
 532 Note: if you pressed this key by mistake, go ahead and eject the
 533 laptop, then dock it back in. Otherwise, the dock may not function as
 534 expected.
 535
 536 When the laptop is docked, the third event above is generated. The
 537 handler for this event should issue the following command to fully
 538 enable the dock:
 539
 540         echo dock > /proc/acpi/ibm/dock
 541
 542 The contents of the /proc/acpi/ibm/dock file shows the current status
 543 of the dock, as provided by the ACPI framework.
 544
 545 The docking support in this driver does not take care of enabling or
 546 disabling any other devices you may have attached to the dock. For
 547 example, a CD drive plugged into the UltraBase needs to be disabled or
 548 enabled separately. See the provided example acpid configuration files
 549 for how this can be accomplished.
 550
 551 There is no support yet for PCI devices that may be attached to a
 552 docking station, e.g. in the ThinkPad Dock II. The driver currently
 553 does not recognize, enable or disable such devices. This means that
 554 the only docking stations currently supported are the X-series
 555 UltraBase docks and "dumb" port replicators like the Mini Dock (the
 556 latter don't need any ACPI support, actually).
 557
 558 UltraBay eject -- /proc/acpi/ibm/bay
 559 ------------------------------------
 560
 561 Inserting or ejecting an UltraBay device requires some actions to be
 562 taken by the operating system to safely make or break the electrical
 563 connections with the device.
 564
 565 This feature generates the following ACPI events:
 566
 567         ibm/bay MSTR 00000003 00000000 -- eject request
 568         ibm/bay MSTR 00000001 00000000 -- eject lever inserted
 569
 570 NOTE: These events will only be generated if the UltraBay was present
 571 when the laptop was originally booted (on the X series, the UltraBay
 572 is in the dock, so it may not be present if the laptop was undocked).
 573 This is due to the current lack of support for hot plugging of devices
 574 in the Linux ACPI framework. If the laptop was booted without the
 575 UltraBay, the following message is shown in the logs:
 576
 577         Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
 578
 579 In this case, no bay-related events are generated but the eject
 580 command described below still works. It can be executed manually or
 581 triggered by a hot key combination.
 582
 583 Sliding the eject lever generates the first event shown above. The
 584 handler for this event should take whatever actions are necessary to
 585 shut down the device in the UltraBay (e.g. call idectl), then issue
 586 the following command:
 587
 588         echo eject > /proc/acpi/ibm/bay
 589
 590 After the LED on the UltraBay goes off, it is safe to pull out the
 591 device.
 592
 593 When the eject lever is inserted, the second event above is
 594 generated. The handler for this event should take whatever actions are
 595 necessary to enable the UltraBay device (e.g. call idectl).
 596
 597 The contents of the /proc/acpi/ibm/bay file shows the current status
 598 of the UltraBay, as provided by the ACPI framework.
 599
 600 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
 601 this feature, you need to supply the experimental=1 parameter when
 602 loading the module):
 603
 604 These models do not have a button near the UltraBay device to request
 605 a hot eject but rather require the laptop to be put to sleep
 606 (suspend-to-ram) before the bay device is ejected or inserted).
 607 The sequence of steps to eject the device is as follows:
 608
 609         echo eject > /proc/acpi/ibm/bay
 610         put the ThinkPad to sleep
 611         remove the drive
 612         resume from sleep
 613         cat /proc/acpi/ibm/bay should show that the drive was removed
 614
 615 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
 616 supported. Use "eject2" instead of "eject" for the second bay.
 617
 618 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
 619 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
 620
 621 CMOS control
 622 ------------
 623
 624 procfs: /proc/acpi/ibm/cmos
 625 sysfs device attribute: cmos_command
 626
 627 This feature is mostly used internally by the ACPI firmware to keep the legacy
 628 CMOS NVRAM bits in sync with the current machine state, and to record this
 629 state so that the ThinkPad will retain such settings across reboots.
 630
 631 Some of these commands actually perform actions in some ThinkPad models, but
 632 this is expected to disappear more and more in newer models.  As an example, in
 633 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
 634 real, but commands 0 to 2 don't control the mixer anymore (they have been
 635 phased out) and just update the NVRAM.
 636
 637 The range of valid cmos command numbers is 0 to 21, but not all have an
 638 effect and the behavior varies from model to model.  Here is the behavior
 639 on the X40 (tpb is the ThinkPad Buttons utility):
 640
 641         0 - Related to "Volume down" key press
 642         1 - Related to "Volume up" key press
 643         2 - Related to "Mute on" key press
 644         3 - Related to "Access IBM" key press
 645         4 - Related to "LCD brightness up" key pess
 646         5 - Related to "LCD brightness down" key press
 647         11 - Related to "toggle screen expansion" key press/function
 648         12 - Related to "ThinkLight on"
 649         13 - Related to "ThinkLight off"
 650         14 - Related to "ThinkLight" key press (toggle thinklight)
 651
 652 The cmos command interface is prone to firmware split-brain problems, as
 653 in newer ThinkPads it is just a compatibility layer.  Do not use it, it is
 654 exported just as a debug tool.
 655
 656 LED control -- /proc/acpi/ibm/led
 657 ---------------------------------
 658
 659 Some of the LED indicators can be controlled through this feature. The
 660 available commands are:
 661
 662         echo '<led number> on' >/proc/acpi/ibm/led
 663         echo '<led number> off' >/proc/acpi/ibm/led
 664         echo '<led number> blink' >/proc/acpi/ibm/led
 665
 666 The <led number> range is 0 to 7. The set of LEDs that can be
 667 controlled varies from model to model. Here is the mapping on the X40:
 668
 669         0 - power
 670         1 - battery (orange)
 671         2 - battery (green)
 672         3 - UltraBase
 673         4 - UltraBay
 674         7 - standby
 675
 676 All of the above can be turned on and off and can be made to blink.
 677
 678 ACPI sounds -- /proc/acpi/ibm/beep
 679 ----------------------------------
 680
 681 The BEEP method is used internally by the ACPI firmware to provide
 682 audible alerts in various situations. This feature allows the same
 683 sounds to be triggered manually.
 684
 685 The commands are non-negative integer numbers:
 686
 687         echo <number> >/proc/acpi/ibm/beep
 688
 689 The valid <number> range is 0 to 17. Not all numbers trigger sounds
 690 and the sounds vary from model to model. Here is the behavior on the
 691 X40:
 692
 693         0 - stop a sound in progress (but use 17 to stop 16)
 694         2 - two beeps, pause, third beep ("low battery")
 695         3 - single beep
 696         4 - high, followed by low-pitched beep ("unable")
 697         5 - single beep
 698         6 - very high, followed by high-pitched beep ("AC/DC")
 699         7 - high-pitched beep
 700         9 - three short beeps
 701         10 - very long beep
 702         12 - low-pitched beep
 703         15 - three high-pitched beeps repeating constantly, stop with 0
 704         16 - one medium-pitched beep repeating constantly, stop with 17
 705         17 - stop 16
 706
 707 Temperature sensors
 708 -------------------
 709
 710 procfs: /proc/acpi/ibm/thermal
 711 sysfs device attributes: (hwmon) temp*_input
 712
 713 Most ThinkPads include six or more separate temperature sensors but only
 714 expose the CPU temperature through the standard ACPI methods.  This
 715 feature shows readings from up to eight different sensors on older
 716 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
 717
 718 For example, on the X40, a typical output may be:
 719 temperatures:   42 42 45 41 36 -128 33 -128
 720
 721 On the T43/p, a typical output may be:
 722 temperatures:   48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
 723
 724 The mapping of thermal sensors to physical locations varies depending on
 725 system-board model (and thus, on ThinkPad model).
 726
 727 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
 728 tries to track down these locations for various models.
 729
 730 Most (newer?) models seem to follow this pattern:
 731
 732 1:  CPU
 733 2:  (depends on model)
 734 3:  (depends on model)
 735 4:  GPU
 736 5:  Main battery: main sensor
 737 6:  Bay battery: main sensor
 738 7:  Main battery: secondary sensor
 739 8:  Bay battery: secondary sensor
 740 9-15: (depends on model)
 741
 742 For the R51 (source: Thomas Gruber):
 743 2:  Mini-PCI
 744 3:  Internal HDD
 745
 746 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
 747 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
 748 2:  System board, left side (near PCMCIA slot), reported as HDAPS temp
 749 3:  PCMCIA slot
 750 9:  MCH (northbridge) to DRAM Bus
 751 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
 752     card, under touchpad
 753 11: Power regulator, underside of system board, below F2 key
 754
 755 The A31 has a very atypical layout for the thermal sensors
 756 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
 757 1:  CPU
 758 2:  Main Battery: main sensor
 759 3:  Power Converter
 760 4:  Bay Battery: main sensor
 761 5:  MCH (northbridge)
 762 6:  PCMCIA/ambient
 763 7:  Main Battery: secondary sensor
 764 8:  Bay Battery: secondary sensor
 765
 766
 767 Procfs notes:
 768         Readings from sensors that are not available return -128.
 769         No commands can be written to this file.
 770
 771 Sysfs notes:
 772         Sensors that are not available return the ENXIO error.  This
 773         status may change at runtime, as there are hotplug thermal
 774         sensors, like those inside the batteries and docks.
 775
 776         thinkpad-acpi thermal sensors are reported through the hwmon
 777         subsystem, and follow all of the hwmon guidelines at
 778         Documentation/hwmon.
 779
 780
 781 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
 782 ------------------------------------------------------------------------
 783
 784 This feature is marked EXPERIMENTAL because the implementation
 785 directly accesses hardware registers and may not work as expected. USE
 786 WITH CAUTION! To use this feature, you need to supply the
 787 experimental=1 parameter when loading the module.
 788
 789 This feature dumps the values of 256 embedded controller
 790 registers. Values which have changed since the last time the registers
 791 were dumped are marked with a star:
 792
 793 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
 794 EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
 795 EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00
 796 EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00
 797 EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80
 798 EC 0x30:  01  07  1a  00  30  04  00  00 *85  00  00  10  00  50  00  00
 799 EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00
 800 EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03 *bc *02 *bc
 801 EC 0x60: *02 *bc *02  00  00  00  00  00  00  00  00  00  00  00  00  00
 802 EC 0x70:  00  00  00  00  00  12  30  40 *24 *26 *2c *27 *20  80 *1f  80
 803 EC 0x80:  00  00  00  06 *37 *0e  03  00  00  00  0e  07  00  00  00  00
 804 EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 805 EC 0xa0: *ff  09  ff  09  ff  ff *64  00 *00 *00 *a2  41 *ff *ff *e0  00
 806 EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 807 EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 808 EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 809 EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03
 810 EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a
 811
 812 This feature can be used to determine the register holding the fan
 813 speed on some models. To do that, do the following:
 814
 815         - make sure the battery is fully charged
 816         - make sure the fan is running
 817         - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
 818
 819 The first step makes sure various charging-related values don't
 820 vary. The second ensures that the fan-related values do vary, since
 821 the fan speed fluctuates a bit. The third will (hopefully) mark the
 822 fan register with a star:
 823
 824 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
 825 EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
 826 EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00
 827 EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00
 828 EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80
 829 EC 0x30:  01  07  1a  00  30  04  00  00  85  00  00  10  00  50  00  00
 830 EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00
 831 EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03  bc  02  bc
 832 EC 0x60:  02  bc  02  00  00  00  00  00  00  00  00  00  00  00  00  00
 833 EC 0x70:  00  00  00  00  00  12  30  40  24  27  2c  27  21  80  1f  80
 834 EC 0x80:  00  00  00  06 *be  0d  03  00  00  00  0e  07  00  00  00  00
 835 EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 836 EC 0xa0:  ff  09  ff  09  ff  ff  64  00  00  00  a2  41  ff  ff  e0  00
 837 EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 838 EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 839 EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
 840 EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03
 841 EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a
 842
 843 Another set of values that varies often is the temperature
 844 readings. Since temperatures don't change vary fast, you can take
 845 several quick dumps to eliminate them.
 846
 847 You can use a similar method to figure out the meaning of other
 848 embedded controller registers - e.g. make sure nothing else changes
 849 except the charging or discharging battery to determine which
 850 registers contain the current battery capacity, etc. If you experiment
 851 with this, do send me your results (including some complete dumps with
 852 a description of the conditions when they were taken.)
 853
 854 LCD brightness control
 855 ----------------------
 856
 857 procfs: /proc/acpi/ibm/brightness
 858 sysfs backlight device "thinkpad_screen"
 859
 860 This feature allows software control of the LCD brightness on ThinkPad
 861 models which don't have a hardware brightness slider.
 862
 863 It has some limitations: the LCD backlight cannot be actually turned on or off
 864 by this interface, and in many ThinkPad models, the "dim while on battery"
 865 functionality will be enabled by the BIOS when this interface is used, and
 866 cannot be controlled.
 867
 868 The backlight control has eight levels, ranging from 0 to 7.  Some of the
 869 levels may not be distinct.
 870
 871 There are two interfaces to the firmware for brightness control, EC and CMOS.
 872 To select which one should be used, use the brightness_mode module parameter:
 873 brightness_mode=1 selects EC mode, brightness_mode=2 selects CMOS mode,
 874 brightness_mode=3 selects both EC and CMOS.  The driver tries to autodetect
 875 which interface to use.
 876
 877 Procfs notes:
 878
 879         The available commands are:
 880
 881         echo up   >/proc/acpi/ibm/brightness
 882         echo down >/proc/acpi/ibm/brightness
 883         echo 'level <level>' >/proc/acpi/ibm/brightness
 884
 885 Sysfs notes:
 886
 887 The interface is implemented through the backlight sysfs class, which is poorly
 888 documented at this time.
 889
 890 Locate the thinkpad_screen device under /sys/class/backlight, and inside it
 891 there will be the following attributes:
 892
 893         max_brightness:
 894                 Reads the maximum brightness the hardware can be set to.
 895                 The minimum is always zero.
 896
 897         actual_brightness:
 898                 Reads what brightness the screen is set to at this instant.
 899
 900         brightness:
 901                 Writes request the driver to change brightness to the given
 902                 value.  Reads will tell you what brightness the driver is trying
 903                 to set the display to when "power" is set to zero and the display
 904                 has not been dimmed by a kernel power management event.
 905
 906         power:
 907                 power management mode, where 0 is "display on", and 1 to 3 will
 908                 dim the display backlight to brightness level 0 because
 909                 thinkpad-acpi cannot really turn the backlight off.  Kernel
 910                 power management events can temporarily increase the current
 911                 power management level, i.e. they can dim the display.
 912
 913
 914 Volume control -- /proc/acpi/ibm/volume
 915 ---------------------------------------
 916
 917 This feature allows volume control on ThinkPad models which don't have
 918 a hardware volume knob. The available commands are:
 919
 920         echo up   >/proc/acpi/ibm/volume
 921         echo down >/proc/acpi/ibm/volume
 922         echo mute >/proc/acpi/ibm/volume
 923         echo 'level <level>' >/proc/acpi/ibm/volume
 924
 925 The <level> number range is 0 to 15 although not all of them may be
 926 distinct. The unmute the volume after the mute command, use either the
 927 up or down command (the level command will not unmute the volume).
 928 The current volume level and mute state is shown in the file.
 929
 930 Fan control and monitoring: fan speed, fan enable/disable
 931 ---------------------------------------------------------
 932
 933 procfs: /proc/acpi/ibm/fan
 934 sysfs device attributes: (hwmon) fan_input, pwm1, pwm1_enable
 935
 936 NOTE NOTE NOTE: fan control operations are disabled by default for
 937 safety reasons.  To enable them, the module parameter "fan_control=1"
 938 must be given to thinkpad-acpi.
 939
 940 This feature attempts to show the current fan speed, control mode and
 941 other fan data that might be available.  The speed is read directly
 942 from the hardware registers of the embedded controller.  This is known
 943 to work on later R, T, X and Z series ThinkPads but may show a bogus
 944 value on other models.
 945
 946 Fan levels:
 947
 948 Most ThinkPad fans work in "levels" at the firmware interface.  Level 0
 949 stops the fan.  The higher the level, the higher the fan speed, although
 950 adjacent levels often map to the same fan speed.  7 is the highest
 951 level, where the fan reaches the maximum recommended speed.
 952
 953 Level "auto" means the EC changes the fan level according to some
 954 internal algorithm, usually based on readings from the thermal sensors.
 955
 956 There is also a "full-speed" level, also known as "disengaged" level.
 957 In this level, the EC disables the speed-locked closed-loop fan control,
 958 and drives the fan as fast as it can go, which might exceed hardware
 959 limits, so use this level with caution.
 960
 961 The fan usually ramps up or down slowly from one speed to another, and
 962 it is normal for the EC to take several seconds to react to fan
 963 commands.  The full-speed level may take up to two minutes to ramp up to
 964 maximum speed, and in some ThinkPads, the tachometer readings go stale
 965 while the EC is transitioning to the full-speed level.
 966
 967 WARNING WARNING WARNING: do not leave the fan disabled unless you are
 968 monitoring all of the temperature sensor readings and you are ready to
 969 enable it if necessary to avoid overheating.
 970
 971 An enabled fan in level "auto" may stop spinning if the EC decides the
 972 ThinkPad is cool enough and doesn't need the extra airflow.  This is
 973 normal, and the EC will spin the fan up if the varios thermal readings
 974 rise too much.
 975
 976 On the X40, this seems to depend on the CPU and HDD temperatures.
 977 Specifically, the fan is turned on when either the CPU temperature
 978 climbs to 56 degrees or the HDD temperature climbs to 46 degrees.  The
 979 fan is turned off when the CPU temperature drops to 49 degrees and the
 980 HDD temperature drops to 41 degrees.  These thresholds cannot
 981 currently be controlled.
 982
 983 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
 984 certain conditions are met.  It will override any fan programming done
 985 through thinkpad-acpi.
 986
 987 The thinkpad-acpi kernel driver can be programmed to revert the fan
 988 level to a safe setting if userspace does not issue one of the procfs
 989 fan commands: "enable", "disable", "level" or "watchdog", or if there
 990 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
 991 set to 1, manual mode) within a configurable amount of time of up to
 992 120 seconds.  This functionality is called fan safety watchdog.
 993
 994 Note that the watchdog timer stops after it enables the fan.  It will be
 995 rearmed again automatically (using the same interval) when one of the
 996 above mentioned fan commands is received.  The fan watchdog is,
 997 therefore, not suitable to protect against fan mode changes made through
 998 means other than the "enable", "disable", and "level" procfs fan
 999 commands, or the hwmon fan control sysfs interface.
1000
1001 Procfs notes:
1002
1003 The fan may be enabled or disabled with the following commands:
1004
1005         echo enable  >/proc/acpi/ibm/fan
1006         echo disable >/proc/acpi/ibm/fan
1007
1008 Placing a fan on level 0 is the same as disabling it.  Enabling a fan
1009 will try to place it in a safe level if it is too slow or disabled.
1010
1011 The fan level can be controlled with the command:
1012
1013         echo 'level <level>' > /proc/acpi/ibm/fan
1014
1015 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1016 "full-speed" (without the quotes).  Not all ThinkPads support the "auto"
1017 and "full-speed" levels.  The driver accepts "disengaged" as an alias for
1018 "full-speed", and reports it as "disengaged" for backwards
1019 compatibility.
1020
1021 On the X31 and X40 (and ONLY on those models), the fan speed can be
1022 controlled to a certain degree.  Once the fan is running, it can be
1023 forced to run faster or slower with the following command:
1024
1025         echo 'speed <speed>' > /proc/acpi/ibm/fan
1026
1027 The sustainable range of fan speeds on the X40 appears to be from about
1028 3700 to about 7350. Values outside this range either do not have any
1029 effect or the fan speed eventually settles somewhere in that range.  The
1030 fan cannot be stopped or started with this command.  This functionality
1031 is incomplete, and not available through the sysfs interface.
1032
1033 To program the safety watchdog, use the "watchdog" command.
1034
1035         echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1036
1037 If you want to disable the watchdog, use 0 as the interval.
1038
1039 Sysfs notes:
1040
1041 The sysfs interface follows the hwmon subsystem guidelines for the most
1042 part, and the exception is the fan safety watchdog.
1043
1044 Writes to any of the sysfs attributes may return the EINVAL error if
1045 that operation is not supported in a given ThinkPad or if the parameter
1046 is out-of-bounds, and EPERM if it is forbidden.  They may also return
1047 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1048 to the firmware).
1049
1050 Features not yet implemented by the driver return ENOSYS.
1051
1052 hwmon device attribute pwm1_enable:
1053         0: PWM offline (fan is set to full-speed mode)
1054         1: Manual PWM control (use pwm1 to set fan level)
1055         2: Hardware PWM control (EC "auto" mode)
1056         3: reserved (Software PWM control, not implemented yet)
1057
1058         Modes 0 and 2 are not supported by all ThinkPads, and the
1059         driver is not always able to detect this.  If it does know a
1060         mode is unsupported, it will return -EINVAL.
1061
1062 hwmon device attribute pwm1:
1063         Fan level, scaled from the firmware values of 0-7 to the hwmon
1064         scale of 0-255.  0 means fan stopped, 255 means highest normal
1065         speed (level 7).
1066
1067         This attribute only commands the fan if pmw1_enable is set to 1
1068         (manual PWM control).
1069
1070 hwmon device attribute fan1_input:
1071         Fan tachometer reading, in RPM.  May go stale on certain
1072         ThinkPads while the EC transitions the PWM to offline mode,
1073         which can take up to two minutes.  May return rubbish on older
1074         ThinkPads.
1075
1076 driver attribute fan_watchdog:
1077         Fan safety watchdog timer interval, in seconds.  Minimum is
1078         1 second, maximum is 120 seconds.  0 disables the watchdog.
1079
1080 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1081
1082 To start the fan in a safe mode: set pwm1_enable to 2.  If that fails
1083 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1084 would be the safest choice, though).
1085
1086
1087 EXPERIMENTAL: WAN
1088 -----------------
1089
1090 procfs: /proc/acpi/ibm/wan
1091 sysfs device attribute: wwan_enable
1092
1093 This feature is marked EXPERIMENTAL because the implementation
1094 directly accesses hardware registers and may not work as expected. USE
1095 WITH CAUTION! To use this feature, you need to supply the
1096 experimental=1 parameter when loading the module.
1097
1098 This feature shows the presence and current state of a W-WAN (Sierra
1099 Wireless EV-DO) device.
1100
1101 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1102 Thinkpad models which come with this module installed.
1103
1104 Procfs notes:
1105
1106 If the W-WAN card is installed, the following commands can be used:
1107
1108         echo enable > /proc/acpi/ibm/wan
1109         echo disable > /proc/acpi/ibm/wan
1110
1111 Sysfs notes:
1112
1113         If the W-WAN card is installed, it can be enabled /
1114         disabled through the "wwan_enable" thinkpad-acpi device
1115         attribute, and its current status can also be queried.
1116
1117         enable:
1118                 0: disables WWAN card / WWAN card is disabled
1119                 1: enables WWAN card / WWAN card is enabled.
1120
1121         Note: this interface will be probably be superseeded by the
1122         generic rfkill class, so it is NOT to be considered stable yet.
1123
1124 Multiple Commands, Module Parameters
1125 ------------------------------------
1126
1127 Multiple commands can be written to the proc files in one shot by
1128 separating them with commas, for example:
1129
1130         echo enable,0xffff > /proc/acpi/ibm/hotkey
1131         echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1132
1133 Commands can also be specified when loading the thinkpad-acpi module,
1134 for example:
1135
1136         modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1137
1138 Enabling debugging output
1139 -------------------------
1140
1141 The module takes a debug paramater which can be used to selectively
1142 enable various classes of debugging output, for example:
1143
1144          modprobe ibm_acpi debug=0xffff
1145
1146 will enable all debugging output classes.  It takes a bitmask, so
1147 to enable more than one output class, just add their values.
1148
1149         Debug bitmask           Description
1150         0x0001                  Initialization and probing
1151         0x0002                  Removal
1152
1153 There is also a kernel build option to enable more debugging
1154 information, which may be necessary to debug driver problems.
1155
1156 The level of debugging information output by the driver can be changed
1157 at runtime through sysfs, using the driver attribute debug_level.  The
1158 attribute takes the same bitmask as the debug module parameter above.
1159
1160 Force loading of module
1161 -----------------------
1162
1163 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1164 the module parameter force_load=1.  Regardless of whether this works or
1165 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1166
1167
1168 Sysfs interface changelog:
1169
1170 0x000100:       Initial sysfs support, as a single platform driver and
1171                 device.
1172 0x000200:       Hot key support for 32 hot keys, and radio slider switch
1173                 support.
1174 0x010000:       Hot keys are now handled by default over the input
1175                 layer, the radio switch generates input event EV_RADIO,
1176                 and the driver enables hot key handling by default in
1177                 the firmware.