Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 ThinkPad ACPI Extras Driver 2 3 Version 0.25 4 October 16th, 2013 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. It was moved to drivers/platform/x86 for 20 kernel 2.6.29 and release 0.22. 21 22 The driver is named "thinkpad-acpi". In some places, like module 23 names and log messages, "thinkpad_acpi" is used because of userspace 24 issues. 25 26 "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too 27 long due to length limitations on some Linux kernel versions. 28 29 Status 30 ------ 31 32 The features currently supported are the following (see below for 33 detailed description): 34 35 - Fn key combinations 36 - Bluetooth enable and disable 37 - video output switching, expansion control 38 - ThinkLight on and off 39 - CMOS/UCMS control 40 - LED control 41 - ACPI sounds 42 - temperature sensors 43 - Experimental: embedded controller register dump 44 - LCD brightness control 45 - Volume control 46 - Fan control and monitoring: fan speed, fan enable/disable 47 - WAN enable and disable 48 - UWB enable and disable 49 50 A compatibility table by model and feature is maintained on the web 51 site, http://ibm-acpi.sf.net/. I appreciate any success or failure 52 reports, especially if they add to or correct the compatibility table. 53 Please include the following information in your report: 54 55 - ThinkPad model name 56 - a copy of your ACPI tables, using the "acpidump" utility 57 - a copy of the output of dmidecode, with serial numbers 58 and UUIDs masked off 59 - which driver features work and which don't 60 - the observed behavior of non-working features 61 62 Any other comments or patches are also more than welcome. 63 64 65 Installation 66 ------------ 67 68 If you are compiling this driver as included in the Linux kernel 69 sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. 70 It is located on the menu path: "Device Drivers" -> "X86 Platform 71 Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". 72 73 74 Features 75 -------- 76 77 The driver exports two different interfaces to userspace, which can be 78 used to access the features it provides. One is a legacy procfs-based 79 interface, which will be removed at some time in the future. The other 80 is a new sysfs-based interface which is not complete yet. 81 82 The procfs interface creates the /proc/acpi/ibm directory. There is a 83 file under that directory for each feature it supports. The procfs 84 interface is mostly frozen, and will change very little if at all: it 85 will not be extended to add any new functionality in the driver, instead 86 all new functionality will be implemented on the sysfs interface. 87 88 The sysfs interface tries to blend in the generic Linux sysfs subsystems 89 and classes as much as possible. Since some of these subsystems are not 90 yet ready or stabilized, it is expected that this interface will change, 91 and any and all userspace programs must deal with it. 92 93 94 Notes about the sysfs interface: 95 96 Unlike what was done with the procfs interface, correctness when talking 97 to the sysfs interfaces will be enforced, as will correctness in the 98 thinkpad-acpi's implementation of sysfs interfaces. 99 100 Also, any bugs in the thinkpad-acpi sysfs driver code or in the 101 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for 102 maximum correctness, even if that means changing an interface in 103 non-compatible ways. As these interfaces mature both in the kernel and 104 in thinkpad-acpi, such changes should become quite rare. 105 106 Applications interfacing to the thinkpad-acpi sysfs interfaces must 107 follow all sysfs guidelines and correctly process all errors (the sysfs 108 interface makes extensive use of errors). File descriptors and open / 109 close operations to the sysfs inodes must also be properly implemented. 110 111 The version of thinkpad-acpi's sysfs interface is exported by the driver 112 as a driver attribute (see below). 113 114 Sysfs driver attributes are on the driver's sysfs attribute space, 115 for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and 116 /sys/bus/platform/drivers/thinkpad_hwmon/ 117 118 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute 119 space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. 120 121 Sysfs device attributes for the sensors and fan are on the 122 thinkpad_hwmon device's sysfs attribute space, but you should locate it 123 looking for a hwmon device with the name attribute of "thinkpad", or 124 better yet, through libsensors. For 4.14+ sysfs attributes were moved to the 125 hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or 126 /sys/class/hwmon/hwmon?). 127 128 Driver version 129 -------------- 130 131 procfs: /proc/acpi/ibm/driver 132 sysfs driver attribute: version 133 134 The driver name and version. No commands can be written to this file. 135 136 137 Sysfs interface version 138 ----------------------- 139 140 sysfs driver attribute: interface_version 141 142 Version of the thinkpad-acpi sysfs interface, as an unsigned long 143 (output in hex format: 0xAAAABBCC), where: 144 AAAA - major revision 145 BB - minor revision 146 CC - bugfix revision 147 148 The sysfs interface version changelog for the driver can be found at the 149 end of this document. Changes to the sysfs interface done by the kernel 150 subsystems are not documented here, nor are they tracked by this 151 attribute. 152 153 Changes to the thinkpad-acpi sysfs interface are only considered 154 non-experimental when they are submitted to Linux mainline, at which 155 point the changes in this interface are documented and interface_version 156 may be updated. If you are using any thinkpad-acpi features not yet 157 sent to mainline for merging, you do so on your own risk: these features 158 may disappear, or be implemented in a different and incompatible way by 159 the time they are merged in Linux mainline. 160 161 Changes that are backwards-compatible by nature (e.g. the addition of 162 attributes that do not change the way the other attributes work) do not 163 always warrant an update of interface_version. Therefore, one must 164 expect that an attribute might not be there, and deal with it properly 165 (an attribute not being there *is* a valid way to make it clear that a 166 feature is not available in sysfs). 167 168 169 Hot keys 170 -------- 171 172 procfs: /proc/acpi/ibm/hotkey 173 sysfs device attribute: hotkey_* 174 175 In a ThinkPad, the ACPI HKEY handler is responsible for communicating 176 some important events and also keyboard hot key presses to the operating 177 system. Enabling the hotkey functionality of thinkpad-acpi signals the 178 firmware that such a driver is present, and modifies how the ThinkPad 179 firmware will behave in many situations. 180 181 The driver enables the HKEY ("hot key") event reporting automatically 182 when loaded, and disables it when it is removed. 183 184 The driver will report HKEY events in the following format: 185 186 ibm/hotkey HKEY 00000080 0000xxxx 187 188 Some of these events refer to hot key presses, but not all of them. 189 190 The driver will generate events over the input layer for hot keys and 191 radio switches, and over the ACPI netlink layer for other events. The 192 input layer support accepts the standard IOCTLs to remap the keycodes 193 assigned to each hot key. 194 195 The hot key bit mask allows some control over which hot keys generate 196 events. If a key is "masked" (bit set to 0 in the mask), the firmware 197 will handle it. If it is "unmasked", it signals the firmware that 198 thinkpad-acpi would prefer to handle it, if the firmware would be so 199 kind to allow it (and it often doesn't!). 200 201 Not all bits in the mask can be modified. Not all bits that can be 202 modified do anything. Not all hot keys can be individually controlled 203 by the mask. Some models do not support the mask at all. The behaviour 204 of the mask is, therefore, highly dependent on the ThinkPad model. 205 206 The driver will filter out any unmasked hotkeys, so even if the firmware 207 doesn't allow disabling an specific hotkey, the driver will not report 208 events for unmasked hotkeys. 209 210 Note that unmasking some keys prevents their default behavior. For 211 example, if Fn+F5 is unmasked, that key will no longer enable/disable 212 Bluetooth by itself in firmware. 213 214 Note also that not all Fn key combinations are supported through ACPI 215 depending on the ThinkPad model and firmware version. On those 216 ThinkPads, it is still possible to support some extra hotkeys by 217 polling the "CMOS NVRAM" at least 10 times per second. The driver 218 attempts to enables this functionality automatically when required. 219 220 procfs notes: 221 222 The following commands can be written to the /proc/acpi/ibm/hotkey file: 223 224 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys 225 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys 226 ... any other 8-hex-digit mask ... 227 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask 228 229 The following commands have been deprecated and will cause the kernel 230 to log a warning: 231 232 echo enable > /proc/acpi/ibm/hotkey -- does nothing 233 echo disable > /proc/acpi/ibm/hotkey -- returns an error 234 235 The procfs interface does not support NVRAM polling control. So as to 236 maintain maximum bug-to-bug compatibility, it does not report any masks, 237 nor does it allow one to manipulate the hot key mask when the firmware 238 does not support masks at all, even if NVRAM polling is in use. 239 240 sysfs notes: 241 242 hotkey_bios_enabled: 243 DEPRECATED, WILL BE REMOVED SOON. 244 245 Returns 0. 246 247 hotkey_bios_mask: 248 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE. 249 250 Returns the hot keys mask when thinkpad-acpi was loaded. 251 Upon module unload, the hot keys mask will be restored 252 to this value. This is always 0x80c, because those are 253 the hotkeys that were supported by ancient firmware 254 without mask support. 255 256 hotkey_enable: 257 DEPRECATED, WILL BE REMOVED SOON. 258 259 0: returns -EPERM 260 1: does nothing 261 262 hotkey_mask: 263 bit mask to enable reporting (and depending on 264 the firmware, ACPI event generation) for each hot key 265 (see above). Returns the current status of the hot keys 266 mask, and allows one to modify it. 267 268 hotkey_all_mask: 269 bit mask that should enable event reporting for all 270 supported hot keys, when echoed to hotkey_mask above. 271 Unless you know which events need to be handled 272 passively (because the firmware *will* handle them 273 anyway), do *not* use hotkey_all_mask. Use 274 hotkey_recommended_mask, instead. You have been warned. 275 276 hotkey_recommended_mask: 277 bit mask that should enable event reporting for all 278 supported hot keys, except those which are always 279 handled by the firmware anyway. Echo it to 280 hotkey_mask above, to use. This is the default mask 281 used by the driver. 282 283 hotkey_source_mask: 284 bit mask that selects which hot keys will the driver 285 poll the NVRAM for. This is auto-detected by the driver 286 based on the capabilities reported by the ACPI firmware, 287 but it can be overridden at runtime. 288 289 Hot keys whose bits are set in hotkey_source_mask are 290 polled for in NVRAM, and reported as hotkey events if 291 enabled in hotkey_mask. Only a few hot keys are 292 available through CMOS NVRAM polling. 293 294 Warning: when in NVRAM mode, the volume up/down/mute 295 keys are synthesized according to changes in the mixer, 296 which uses a single volume up or volume down hotkey 297 press to unmute, as per the ThinkPad volume mixer user 298 interface. When in ACPI event mode, volume up/down/mute 299 events are reported by the firmware and can behave 300 differently (and that behaviour changes with firmware 301 version -- not just with firmware models -- as well as 302 OSI(Linux) state). 303 304 hotkey_poll_freq: 305 frequency in Hz for hot key polling. It must be between 306 0 and 25 Hz. Polling is only carried out when strictly 307 needed. 308 309 Setting hotkey_poll_freq to zero disables polling, and 310 will cause hot key presses that require NVRAM polling 311 to never be reported. 312 313 Setting hotkey_poll_freq too low may cause repeated 314 pressings of the same hot key to be misreported as a 315 single key press, or to not even be detected at all. 316 The recommended polling frequency is 10Hz. 317 318 hotkey_radio_sw: 319 If the ThinkPad has a hardware radio switch, this 320 attribute will read 0 if the switch is in the "radios 321 disabled" position, and 1 if the switch is in the 322 "radios enabled" position. 323 324 This attribute has poll()/select() support. 325 326 hotkey_tablet_mode: 327 If the ThinkPad has tablet capabilities, this attribute 328 will read 0 if the ThinkPad is in normal mode, and 329 1 if the ThinkPad is in tablet mode. 330 331 This attribute has poll()/select() support. 332 333 wakeup_reason: 334 Set to 1 if the system is waking up because the user 335 requested a bay ejection. Set to 2 if the system is 336 waking up because the user requested the system to 337 undock. Set to zero for normal wake-ups or wake-ups 338 due to unknown reasons. 339 340 This attribute has poll()/select() support. 341 342 wakeup_hotunplug_complete: 343 Set to 1 if the system was waken up because of an 344 undock or bay ejection request, and that request 345 was successfully completed. At this point, it might 346 be useful to send the system back to sleep, at the 347 user's choice. Refer to HKEY events 0x4003 and 348 0x3003, below. 349 350 This attribute has poll()/select() support. 351 352 input layer notes: 353 354 A Hot key is mapped to a single input layer EV_KEY event, possibly 355 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan 356 code. An EV_SYN event will always be generated to mark the end of the 357 event block. 358 359 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be 360 used as a helper to remap keys, only. They are particularly useful when 361 remapping KEY_UNKNOWN keys. 362 363 The events are available in an input device, with the following id: 364 365 Bus: BUS_HOST 366 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or 367 0x17aa (PCI_VENDOR_ID_LENOVO) 368 product: 0x5054 ("TP") 369 version: 0x4101 370 371 The version will have its LSB incremented if the keymap changes in a 372 backwards-compatible way. The MSB shall always be 0x41 for this input 373 device. If the MSB is not 0x41, do not use the device as described in 374 this section, as it is either something else (e.g. another input device 375 exported by a thinkpad driver, such as HDAPS) or its functionality has 376 been changed in a non-backwards compatible way. 377 378 Adding other event types for other functionalities shall be considered a 379 backwards-compatible change for this input device. 380 381 Thinkpad-acpi Hot Key event map (version 0x4101): 382 383 ACPI Scan 384 event code Key Notes 385 386 0x1001 0x00 FN+F1 - 387 388 0x1002 0x01 FN+F2 IBM: battery (rare) 389 Lenovo: Screen lock 390 391 0x1003 0x02 FN+F3 Many IBM models always report 392 this hot key, even with hot keys 393 disabled or with Fn+F3 masked 394 off 395 IBM: screen lock, often turns 396 off the ThinkLight as side-effect 397 Lenovo: battery 398 399 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button 400 semantics, i.e. sleep-to-RAM). 401 It always generates some kind 402 of event, either the hot key 403 event or an ACPI sleep button 404 event. The firmware may 405 refuse to generate further FN+F4 406 key presses until a S3 or S4 ACPI 407 sleep cycle is performed or some 408 time passes. 409 410 0x1005 0x04 FN+F5 Radio. Enables/disables 411 the internal Bluetooth hardware 412 and W-WAN card if left in control 413 of the firmware. Does not affect 414 the WLAN card. 415 Should be used to turn on/off all 416 radios (Bluetooth+W-WAN+WLAN), 417 really. 418 419 0x1006 0x05 FN+F6 - 420 421 0x1007 0x06 FN+F7 Video output cycle. 422 Do you feel lucky today? 423 424 0x1008 0x07 FN+F8 IBM: toggle screen expand 425 Lenovo: configure UltraNav, 426 or toggle screen expand 427 428 0x1009 0x08 FN+F9 - 429 .. .. .. 430 0x100B 0x0A FN+F11 - 431 432 0x100C 0x0B FN+F12 Sleep to disk. You are always 433 supposed to handle it yourself, 434 either through the ACPI event, 435 or through a hotkey event. 436 The firmware may refuse to 437 generate further FN+F12 key 438 press events until a S3 or S4 439 ACPI sleep cycle is performed, 440 or some time passes. 441 442 0x100D 0x0C FN+BACKSPACE - 443 0x100E 0x0D FN+INSERT - 444 0x100F 0x0E FN+DELETE - 445 446 0x1010 0x0F FN+HOME Brightness up. This key is 447 always handled by the firmware 448 in IBM ThinkPads, even when 449 unmasked. Just leave it alone. 450 For Lenovo ThinkPads with a new 451 BIOS, it has to be handled either 452 by the ACPI OSI, or by userspace. 453 The driver does the right thing, 454 never mess with this. 455 0x1011 0x10 FN+END Brightness down. See brightness 456 up for details. 457 458 0x1012 0x11 FN+PGUP ThinkLight toggle. This key is 459 always handled by the firmware, 460 even when unmasked. 461 462 0x1013 0x12 FN+PGDOWN - 463 464 0x1014 0x13 FN+SPACE Zoom key 465 466 0x1015 0x14 VOLUME UP Internal mixer volume up. This 467 key is always handled by the 468 firmware, even when unmasked. 469 NOTE: Lenovo seems to be changing 470 this. 471 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This 472 key is always handled by the 473 firmware, even when unmasked. 474 NOTE: Lenovo seems to be changing 475 this. 476 0x1017 0x16 MUTE Mute internal mixer. This 477 key is always handled by the 478 firmware, even when unmasked. 479 480 0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key 481 482 0x1019 0x18 unknown 483 .. .. .. 484 0x1020 0x1F unknown 485 486 The ThinkPad firmware does not allow one to differentiate when most hot 487 keys are pressed or released (either that, or we don't know how to, yet). 488 For these keys, the driver generates a set of events for a key press and 489 immediately issues the same set of events for a key release. It is 490 unknown by the driver if the ThinkPad firmware triggered these events on 491 hot key press or release, but the firmware will do it for either one, not 492 both. 493 494 If a key is mapped to KEY_RESERVED, it generates no input events at all. 495 If a key is mapped to KEY_UNKNOWN, it generates an input event that 496 includes an scan code. If a key is mapped to anything else, it will 497 generate input device EV_KEY events. 498 499 In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW 500 events for switches: 501 502 SW_RFKILL_ALL T60 and later hardware rfkill rocker switch 503 SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A 504 505 Non hotkey ACPI HKEY event map: 506 ------------------------------- 507 508 Events that are never propagated by the driver: 509 510 0x2304 System is waking up from suspend to undock 511 0x2305 System is waking up from suspend to eject bay 512 0x2404 System is waking up from hibernation to undock 513 0x2405 System is waking up from hibernation to eject bay 514 0x5001 Lid closed 515 0x5002 Lid opened 516 0x5009 Tablet swivel: switched to tablet mode 517 0x500A Tablet swivel: switched to normal mode 518 0x5010 Brightness level changed/control event 519 0x6000 KEYBOARD: Numlock key pressed 520 0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) 521 0x7000 Radio Switch may have changed state 522 523 524 Events that are propagated by the driver to userspace: 525 526 0x2313 ALARM: System is waking up from suspend because 527 the battery is nearly empty 528 0x2413 ALARM: System is waking up from hibernation because 529 the battery is nearly empty 530 0x3003 Bay ejection (see 0x2x05) complete, can sleep again 531 0x3006 Bay hotplug request (hint to power up SATA link when 532 the optical drive tray is ejected) 533 0x4003 Undocked (see 0x2x04), can sleep again 534 0x4010 Docked into hotplug port replicator (non-ACPI dock) 535 0x4011 Undocked from hotplug port replicator (non-ACPI dock) 536 0x500B Tablet pen inserted into its storage bay 537 0x500C Tablet pen removed from its storage bay 538 0x6011 ALARM: battery is too hot 539 0x6012 ALARM: battery is extremely hot 540 0x6021 ALARM: a sensor is too hot 541 0x6022 ALARM: a sensor is extremely hot 542 0x6030 System thermal table changed 543 0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) 544 0x60C0 X1 Yoga 2016, Tablet mode status changed 545 546 Battery nearly empty alarms are a last resort attempt to get the 547 operating system to hibernate or shutdown cleanly (0x2313), or shutdown 548 cleanly (0x2413) before power is lost. They must be acted upon, as the 549 wake up caused by the firmware will have negated most safety nets... 550 551 When any of the "too hot" alarms happen, according to Lenovo the user 552 should suspend or hibernate the laptop (and in the case of battery 553 alarms, unplug the AC adapter) to let it cool down. These alarms do 554 signal that something is wrong, they should never happen on normal 555 operating conditions. 556 557 The "extremely hot" alarms are emergencies. According to Lenovo, the 558 operating system is to force either an immediate suspend or hibernate 559 cycle, or a system shutdown. Obviously, something is very wrong if this 560 happens. 561 562 563 Brightness hotkey notes: 564 565 Don't mess with the brightness hotkeys in a Thinkpad. If you want 566 notifications for OSD, use the sysfs backlight class event support. 567 568 The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events 569 automatically for the cases were userspace has to do something to 570 implement brightness changes. When you override these events, you will 571 either fail to handle properly the ThinkPads that require explicit 572 action to change backlight brightness, or the ThinkPads that require 573 that no action be taken to work properly. 574 575 576 Bluetooth 577 --------- 578 579 procfs: /proc/acpi/ibm/bluetooth 580 sysfs device attribute: bluetooth_enable (deprecated) 581 sysfs rfkill class: switch "tpacpi_bluetooth_sw" 582 583 This feature shows the presence and current state of a ThinkPad 584 Bluetooth device in the internal ThinkPad CDC slot. 585 586 If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, 587 so it is kept across reboots and power-off. 588 589 Procfs notes: 590 591 If Bluetooth is installed, the following commands can be used: 592 593 echo enable > /proc/acpi/ibm/bluetooth 594 echo disable > /proc/acpi/ibm/bluetooth 595 596 Sysfs notes: 597 598 If the Bluetooth CDC card is installed, it can be enabled / 599 disabled through the "bluetooth_enable" thinkpad-acpi device 600 attribute, and its current status can also be queried. 601 602 enable: 603 0: disables Bluetooth / Bluetooth is disabled 604 1: enables Bluetooth / Bluetooth is enabled. 605 606 Note: this interface has been superseded by the generic rfkill 607 class. It has been deprecated, and it will be removed in year 608 2010. 609 610 rfkill controller switch "tpacpi_bluetooth_sw": refer to 611 Documentation/rfkill.txt for details. 612 613 614 Video output control -- /proc/acpi/ibm/video 615 -------------------------------------------- 616 617 This feature allows control over the devices used for video output - 618 LCD, CRT or DVI (if available). The following commands are available: 619 620 echo lcd_enable > /proc/acpi/ibm/video 621 echo lcd_disable > /proc/acpi/ibm/video 622 echo crt_enable > /proc/acpi/ibm/video 623 echo crt_disable > /proc/acpi/ibm/video 624 echo dvi_enable > /proc/acpi/ibm/video 625 echo dvi_disable > /proc/acpi/ibm/video 626 echo auto_enable > /proc/acpi/ibm/video 627 echo auto_disable > /proc/acpi/ibm/video 628 echo expand_toggle > /proc/acpi/ibm/video 629 echo video_switch > /proc/acpi/ibm/video 630 631 NOTE: Access to this feature is restricted to processes owning the 632 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly 633 enough with some versions of X.org to crash it. 634 635 Each video output device can be enabled or disabled individually. 636 Reading /proc/acpi/ibm/video shows the status of each device. 637 638 Automatic video switching can be enabled or disabled. When automatic 639 video switching is enabled, certain events (e.g. opening the lid, 640 docking or undocking) cause the video output device to change 641 automatically. While this can be useful, it also causes flickering 642 and, on the X40, video corruption. By disabling automatic switching, 643 the flickering or video corruption can be avoided. 644 645 The video_switch command cycles through the available video outputs 646 (it simulates the behavior of Fn-F7). 647 648 Video expansion can be toggled through this feature. This controls 649 whether the display is expanded to fill the entire LCD screen when a 650 mode with less than full resolution is used. Note that the current 651 video expansion status cannot be determined through this feature. 652 653 Note that on many models (particularly those using Radeon graphics 654 chips) the X driver configures the video card in a way which prevents 655 Fn-F7 from working. This also disables the video output switching 656 features of this driver, as it uses the same ACPI methods as 657 Fn-F7. Video switching on the console should still work. 658 659 UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 660 661 662 ThinkLight control 663 ------------------ 664 665 procfs: /proc/acpi/ibm/light 666 sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED 667 668 procfs notes: 669 670 The ThinkLight status can be read and set through the procfs interface. A 671 few models which do not make the status available will show the ThinkLight 672 status as "unknown". The available commands are: 673 674 echo on > /proc/acpi/ibm/light 675 echo off > /proc/acpi/ibm/light 676 677 sysfs notes: 678 679 The ThinkLight sysfs interface is documented by the LED class 680 documentation, in Documentation/leds/leds-class.txt. The ThinkLight LED name 681 is "tpacpi::thinklight". 682 683 Due to limitations in the sysfs LED class, if the status of the ThinkLight 684 cannot be read or if it is unknown, thinkpad-acpi will report it as "off". 685 It is impossible to know if the status returned through sysfs is valid. 686 687 688 CMOS/UCMS control 689 ----------------- 690 691 procfs: /proc/acpi/ibm/cmos 692 sysfs device attribute: cmos_command 693 694 This feature is mostly used internally by the ACPI firmware to keep the legacy 695 CMOS NVRAM bits in sync with the current machine state, and to record this 696 state so that the ThinkPad will retain such settings across reboots. 697 698 Some of these commands actually perform actions in some ThinkPad models, but 699 this is expected to disappear more and more in newer models. As an example, in 700 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for 701 real, but commands 0 to 2 don't control the mixer anymore (they have been 702 phased out) and just update the NVRAM. 703 704 The range of valid cmos command numbers is 0 to 21, but not all have an 705 effect and the behavior varies from model to model. Here is the behavior 706 on the X40 (tpb is the ThinkPad Buttons utility): 707 708 0 - Related to "Volume down" key press 709 1 - Related to "Volume up" key press 710 2 - Related to "Mute on" key press 711 3 - Related to "Access IBM" key press 712 4 - Related to "LCD brightness up" key press 713 5 - Related to "LCD brightness down" key press 714 11 - Related to "toggle screen expansion" key press/function 715 12 - Related to "ThinkLight on" 716 13 - Related to "ThinkLight off" 717 14 - Related to "ThinkLight" key press (toggle ThinkLight) 718 719 The cmos command interface is prone to firmware split-brain problems, as 720 in newer ThinkPads it is just a compatibility layer. Do not use it, it is 721 exported just as a debug tool. 722 723 724 LED control 725 ----------- 726 727 procfs: /proc/acpi/ibm/led 728 sysfs attributes: as per LED class, see below for names 729 730 Some of the LED indicators can be controlled through this feature. On 731 some older ThinkPad models, it is possible to query the status of the 732 LED indicators as well. Newer ThinkPads cannot query the real status 733 of the LED indicators. 734 735 Because misuse of the LEDs could induce an unaware user to perform 736 dangerous actions (like undocking or ejecting a bay device while the 737 buses are still active), or mask an important alarm (such as a nearly 738 empty battery, or a broken battery), access to most LEDs is 739 restricted. 740 741 Unrestricted access to all LEDs requires that thinkpad-acpi be 742 compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. 743 Distributions must never enable this option. Individual users that 744 are aware of the consequences are welcome to enabling it. 745 746 Audio mute and microphone mute LEDs are supported, but currently not 747 visible to userspace. They are used by the snd-hda-intel audio driver. 748 749 procfs notes: 750 751 The available commands are: 752 753 echo '<LED number> on' >/proc/acpi/ibm/led 754 echo '<LED number> off' >/proc/acpi/ibm/led 755 echo '<LED number> blink' >/proc/acpi/ibm/led 756 757 The <LED number> range is 0 to 15. The set of LEDs that can be 758 controlled varies from model to model. Here is the common ThinkPad 759 mapping: 760 761 0 - power 762 1 - battery (orange) 763 2 - battery (green) 764 3 - UltraBase/dock 765 4 - UltraBay 766 5 - UltraBase battery slot 767 6 - (unknown) 768 7 - standby 769 8 - dock status 1 770 9 - dock status 2 771 10, 11 - (unknown) 772 12 - thinkvantage 773 13, 14, 15 - (unknown) 774 775 All of the above can be turned on and off and can be made to blink. 776 777 sysfs notes: 778 779 The ThinkPad LED sysfs interface is described in detail by the LED class 780 documentation, in Documentation/leds/leds-class.txt. 781 782 The LEDs are named (in LED ID order, from 0 to 12): 783 "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", 784 "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", 785 "tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", 786 "tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", 787 "tpacpi::thinkvantage". 788 789 Due to limitations in the sysfs LED class, if the status of the LED 790 indicators cannot be read due to an error, thinkpad-acpi will report it as 791 a brightness of zero (same as LED off). 792 793 If the thinkpad firmware doesn't support reading the current status, 794 trying to read the current LED brightness will just return whatever 795 brightness was last written to that attribute. 796 797 These LEDs can blink using hardware acceleration. To request that a 798 ThinkPad indicator LED should blink in hardware accelerated mode, use the 799 "timer" trigger, and leave the delay_on and delay_off parameters set to 800 zero (to request hardware acceleration autodetection). 801 802 LEDs that are known not to exist in a given ThinkPad model are not 803 made available through the sysfs interface. If you have a dock and you 804 notice there are LEDs listed for your ThinkPad that do not exist (and 805 are not in the dock), or if you notice that there are missing LEDs, 806 a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. 807 808 809 ACPI sounds -- /proc/acpi/ibm/beep 810 ---------------------------------- 811 812 The BEEP method is used internally by the ACPI firmware to provide 813 audible alerts in various situations. This feature allows the same 814 sounds to be triggered manually. 815 816 The commands are non-negative integer numbers: 817 818 echo <number> >/proc/acpi/ibm/beep 819 820 The valid <number> range is 0 to 17. Not all numbers trigger sounds 821 and the sounds vary from model to model. Here is the behavior on the 822 X40: 823 824 0 - stop a sound in progress (but use 17 to stop 16) 825 2 - two beeps, pause, third beep ("low battery") 826 3 - single beep 827 4 - high, followed by low-pitched beep ("unable") 828 5 - single beep 829 6 - very high, followed by high-pitched beep ("AC/DC") 830 7 - high-pitched beep 831 9 - three short beeps 832 10 - very long beep 833 12 - low-pitched beep 834 15 - three high-pitched beeps repeating constantly, stop with 0 835 16 - one medium-pitched beep repeating constantly, stop with 17 836 17 - stop 16 837 838 839 Temperature sensors 840 ------------------- 841 842 procfs: /proc/acpi/ibm/thermal 843 sysfs device attributes: (hwmon "thinkpad") temp*_input 844 845 Most ThinkPads include six or more separate temperature sensors but only 846 expose the CPU temperature through the standard ACPI methods. This 847 feature shows readings from up to eight different sensors on older 848 ThinkPads, and up to sixteen different sensors on newer ThinkPads. 849 850 For example, on the X40, a typical output may be: 851 temperatures: 42 42 45 41 36 -128 33 -128 852 853 On the T43/p, a typical output may be: 854 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 855 856 The mapping of thermal sensors to physical locations varies depending on 857 system-board model (and thus, on ThinkPad model). 858 859 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that 860 tries to track down these locations for various models. 861 862 Most (newer?) models seem to follow this pattern: 863 864 1: CPU 865 2: (depends on model) 866 3: (depends on model) 867 4: GPU 868 5: Main battery: main sensor 869 6: Bay battery: main sensor 870 7: Main battery: secondary sensor 871 8: Bay battery: secondary sensor 872 9-15: (depends on model) 873 874 For the R51 (source: Thomas Gruber): 875 2: Mini-PCI 876 3: Internal HDD 877 878 For the T43, T43/p (source: Shmidoax/Thinkwiki.org) 879 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p 880 2: System board, left side (near PCMCIA slot), reported as HDAPS temp 881 3: PCMCIA slot 882 9: MCH (northbridge) to DRAM Bus 883 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI 884 card, under touchpad 885 11: Power regulator, underside of system board, below F2 key 886 887 The A31 has a very atypical layout for the thermal sensors 888 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) 889 1: CPU 890 2: Main Battery: main sensor 891 3: Power Converter 892 4: Bay Battery: main sensor 893 5: MCH (northbridge) 894 6: PCMCIA/ambient 895 7: Main Battery: secondary sensor 896 8: Bay Battery: secondary sensor 897 898 899 Procfs notes: 900 Readings from sensors that are not available return -128. 901 No commands can be written to this file. 902 903 Sysfs notes: 904 Sensors that are not available return the ENXIO error. This 905 status may change at runtime, as there are hotplug thermal 906 sensors, like those inside the batteries and docks. 907 908 thinkpad-acpi thermal sensors are reported through the hwmon 909 subsystem, and follow all of the hwmon guidelines at 910 Documentation/hwmon. 911 912 EXPERIMENTAL: Embedded controller register dump 913 ----------------------------------------------- 914 915 This feature is not included in the thinkpad driver anymore. 916 Instead the EC can be accessed through /sys/kernel/debug/ec with 917 a userspace tool which can be found here: 918 ftp://ftp.suse.com/pub/people/trenn/sources/ec 919 920 Use it to determine the register holding the fan 921 speed on some models. To do that, do the following: 922 - make sure the battery is fully charged 923 - make sure the fan is running 924 - use above mentioned tool to read out the EC 925 926 Often fan and temperature values vary between 927 readings. Since temperatures don't change vary fast, you can take 928 several quick dumps to eliminate them. 929 930 You can use a similar method to figure out the meaning of other 931 embedded controller registers - e.g. make sure nothing else changes 932 except the charging or discharging battery to determine which 933 registers contain the current battery capacity, etc. If you experiment 934 with this, do send me your results (including some complete dumps with 935 a description of the conditions when they were taken.) 936 937 938 LCD brightness control 939 ---------------------- 940 941 procfs: /proc/acpi/ibm/brightness 942 sysfs backlight device "thinkpad_screen" 943 944 This feature allows software control of the LCD brightness on ThinkPad 945 models which don't have a hardware brightness slider. 946 947 It has some limitations: the LCD backlight cannot be actually turned 948 on or off by this interface, it just controls the backlight brightness 949 level. 950 951 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control 952 has eight brightness levels, ranging from 0 to 7. Some of the levels 953 may not be distinct. Later Lenovo models that implement the ACPI 954 display backlight brightness control methods have 16 levels, ranging 955 from 0 to 15. 956 957 For IBM ThinkPads, there are two interfaces to the firmware for direct 958 brightness control, EC and UCMS (or CMOS). To select which one should be 959 used, use the brightness_mode module parameter: brightness_mode=1 selects 960 EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC 961 mode with NVRAM backing (so that brightness changes are remembered across 962 shutdown/reboot). 963 964 The driver tries to select which interface to use from a table of 965 defaults for each ThinkPad model. If it makes a wrong choice, please 966 report this as a bug, so that we can fix it. 967 968 Lenovo ThinkPads only support brightness_mode=2 (UCMS). 969 970 When display backlight brightness controls are available through the 971 standard ACPI interface, it is best to use it instead of this direct 972 ThinkPad-specific interface. The driver will disable its native 973 backlight brightness control interface if it detects that the standard 974 ACPI interface is available in the ThinkPad. 975 976 If you want to use the thinkpad-acpi backlight brightness control 977 instead of the generic ACPI video backlight brightness control for some 978 reason, you should use the acpi_backlight=vendor kernel parameter. 979 980 The brightness_enable module parameter can be used to control whether 981 the LCD brightness control feature will be enabled when available. 982 brightness_enable=0 forces it to be disabled. brightness_enable=1 983 forces it to be enabled when available, even if the standard ACPI 984 interface is also available. 985 986 Procfs notes: 987 988 The available commands are: 989 990 echo up >/proc/acpi/ibm/brightness 991 echo down >/proc/acpi/ibm/brightness 992 echo 'level <level>' >/proc/acpi/ibm/brightness 993 994 Sysfs notes: 995 996 The interface is implemented through the backlight sysfs class, which is 997 poorly documented at this time. 998 999 Locate the thinkpad_screen device under /sys/class/backlight, and inside 1000 it there will be the following attributes: 1001 1002 max_brightness: 1003 Reads the maximum brightness the hardware can be set to. 1004 The minimum is always zero. 1005 1006 actual_brightness: 1007 Reads what brightness the screen is set to at this instant. 1008 1009 brightness: 1010 Writes request the driver to change brightness to the 1011 given value. Reads will tell you what brightness the 1012 driver is trying to set the display to when "power" is set 1013 to zero and the display has not been dimmed by a kernel 1014 power management event. 1015 1016 power: 1017 power management mode, where 0 is "display on", and 1 to 3 1018 will dim the display backlight to brightness level 0 1019 because thinkpad-acpi cannot really turn the backlight 1020 off. Kernel power management events can temporarily 1021 increase the current power management level, i.e. they can 1022 dim the display. 1023 1024 1025 WARNING: 1026 1027 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change 1028 interface and the ACPI-based backlight level change interface 1029 (available on newer BIOSes, and driven by the Linux ACPI video driver) 1030 at the same time. The two will interact in bad ways, do funny things, 1031 and maybe reduce the life of the backlight lamps by needlessly kicking 1032 its level up and down at every change. 1033 1034 1035 Volume control (Console Audio control) 1036 -------------------------------------- 1037 1038 procfs: /proc/acpi/ibm/volume 1039 ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" 1040 1041 NOTE: by default, the volume control interface operates in read-only 1042 mode, as it is supposed to be used for on-screen-display purposes. 1043 The read/write mode can be enabled through the use of the 1044 "volume_control=1" module parameter. 1045 1046 NOTE: distros are urged to not enable volume_control by default, this 1047 should be done by the local admin only. The ThinkPad UI is for the 1048 console audio control to be done through the volume keys only, and for 1049 the desktop environment to just provide on-screen-display feedback. 1050 Software volume control should be done only in the main AC97/HDA 1051 mixer. 1052 1053 1054 About the ThinkPad Console Audio control: 1055 1056 ThinkPads have a built-in amplifier and muting circuit that drives the 1057 console headphone and speakers. This circuit is after the main AC97 1058 or HDA mixer in the audio path, and under exclusive control of the 1059 firmware. 1060 1061 ThinkPads have three special hotkeys to interact with the console 1062 audio control: volume up, volume down and mute. 1063 1064 It is worth noting that the normal way the mute function works (on 1065 ThinkPads that do not have a "mute LED") is: 1066 1067 1. Press mute to mute. It will *always* mute, you can press it as 1068 many times as you want, and the sound will remain mute. 1069 1070 2. Press either volume key to unmute the ThinkPad (it will _not_ 1071 change the volume, it will just unmute). 1072 1073 This is a very superior design when compared to the cheap software-only 1074 mute-toggle solution found on normal consumer laptops: you can be 1075 absolutely sure the ThinkPad will not make noise if you press the mute 1076 button, no matter the previous state. 1077 1078 The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain 1079 amplifiers driving the speakers and headphone output, and the firmware 1080 also handles volume control for the headphone and speakers on these 1081 ThinkPads without any help from the operating system (this volume 1082 control stage exists after the main AC97 or HDA mixer in the audio 1083 path). 1084 1085 The newer Lenovo models only have firmware mute control, and depend on 1086 the main HDA mixer to do volume control (which is done by the operating 1087 system). In this case, the volume keys are filtered out for unmute 1088 key press (there are some firmware bugs in this area) and delivered as 1089 normal key presses to the operating system (thinkpad-acpi is not 1090 involved). 1091 1092 1093 The ThinkPad-ACPI volume control: 1094 1095 The preferred way to interact with the Console Audio control is the 1096 ALSA interface. 1097 1098 The legacy procfs interface allows one to read the current state, 1099 and if volume control is enabled, accepts the following commands: 1100 1101 echo up >/proc/acpi/ibm/volume 1102 echo down >/proc/acpi/ibm/volume 1103 echo mute >/proc/acpi/ibm/volume 1104 echo unmute >/proc/acpi/ibm/volume 1105 echo 'level <level>' >/proc/acpi/ibm/volume 1106 1107 The <level> number range is 0 to 14 although not all of them may be 1108 distinct. To unmute the volume after the mute command, use either the 1109 up or down command (the level command will not unmute the volume), or 1110 the unmute command. 1111 1112 You can use the volume_capabilities parameter to tell the driver 1113 whether your thinkpad has volume control or mute-only control: 1114 volume_capabilities=1 for mixers with mute and volume control, 1115 volume_capabilities=2 for mixers with only mute control. 1116 1117 If the driver misdetects the capabilities for your ThinkPad model, 1118 please report this to ibm-acpi-devel@lists.sourceforge.net, so that we 1119 can update the driver. 1120 1121 There are two strategies for volume control. To select which one 1122 should be used, use the volume_mode module parameter: volume_mode=1 1123 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing 1124 (so that volume/mute changes are remembered across shutdown/reboot). 1125 1126 The driver will operate in volume_mode=3 by default. If that does not 1127 work well on your ThinkPad model, please report this to 1128 ibm-acpi-devel@lists.sourceforge.net. 1129 1130 The driver supports the standard ALSA module parameters. If the ALSA 1131 mixer is disabled, the driver will disable all volume functionality. 1132 1133 1134 Fan control and monitoring: fan speed, fan enable/disable 1135 --------------------------------------------------------- 1136 1137 procfs: /proc/acpi/ibm/fan 1138 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, 1139 pwm1_enable, fan2_input 1140 sysfs hwmon driver attributes: fan_watchdog 1141 1142 NOTE NOTE NOTE: fan control operations are disabled by default for 1143 safety reasons. To enable them, the module parameter "fan_control=1" 1144 must be given to thinkpad-acpi. 1145 1146 This feature attempts to show the current fan speed, control mode and 1147 other fan data that might be available. The speed is read directly 1148 from the hardware registers of the embedded controller. This is known 1149 to work on later R, T, X and Z series ThinkPads but may show a bogus 1150 value on other models. 1151 1152 Some Lenovo ThinkPads support a secondary fan. This fan cannot be 1153 controlled separately, it shares the main fan control. 1154 1155 Fan levels: 1156 1157 Most ThinkPad fans work in "levels" at the firmware interface. Level 0 1158 stops the fan. The higher the level, the higher the fan speed, although 1159 adjacent levels often map to the same fan speed. 7 is the highest 1160 level, where the fan reaches the maximum recommended speed. 1161 1162 Level "auto" means the EC changes the fan level according to some 1163 internal algorithm, usually based on readings from the thermal sensors. 1164 1165 There is also a "full-speed" level, also known as "disengaged" level. 1166 In this level, the EC disables the speed-locked closed-loop fan control, 1167 and drives the fan as fast as it can go, which might exceed hardware 1168 limits, so use this level with caution. 1169 1170 The fan usually ramps up or down slowly from one speed to another, and 1171 it is normal for the EC to take several seconds to react to fan 1172 commands. The full-speed level may take up to two minutes to ramp up to 1173 maximum speed, and in some ThinkPads, the tachometer readings go stale 1174 while the EC is transitioning to the full-speed level. 1175 1176 WARNING WARNING WARNING: do not leave the fan disabled unless you are 1177 monitoring all of the temperature sensor readings and you are ready to 1178 enable it if necessary to avoid overheating. 1179 1180 An enabled fan in level "auto" may stop spinning if the EC decides the 1181 ThinkPad is cool enough and doesn't need the extra airflow. This is 1182 normal, and the EC will spin the fan up if the various thermal readings 1183 rise too much. 1184 1185 On the X40, this seems to depend on the CPU and HDD temperatures. 1186 Specifically, the fan is turned on when either the CPU temperature 1187 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The 1188 fan is turned off when the CPU temperature drops to 49 degrees and the 1189 HDD temperature drops to 41 degrees. These thresholds cannot 1190 currently be controlled. 1191 1192 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when 1193 certain conditions are met. It will override any fan programming done 1194 through thinkpad-acpi. 1195 1196 The thinkpad-acpi kernel driver can be programmed to revert the fan 1197 level to a safe setting if userspace does not issue one of the procfs 1198 fan commands: "enable", "disable", "level" or "watchdog", or if there 1199 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is 1200 set to 1, manual mode) within a configurable amount of time of up to 1201 120 seconds. This functionality is called fan safety watchdog. 1202 1203 Note that the watchdog timer stops after it enables the fan. It will be 1204 rearmed again automatically (using the same interval) when one of the 1205 above mentioned fan commands is received. The fan watchdog is, 1206 therefore, not suitable to protect against fan mode changes made through 1207 means other than the "enable", "disable", and "level" procfs fan 1208 commands, or the hwmon fan control sysfs interface. 1209 1210 Procfs notes: 1211 1212 The fan may be enabled or disabled with the following commands: 1213 1214 echo enable >/proc/acpi/ibm/fan 1215 echo disable >/proc/acpi/ibm/fan 1216 1217 Placing a fan on level 0 is the same as disabling it. Enabling a fan 1218 will try to place it in a safe level if it is too slow or disabled. 1219 1220 The fan level can be controlled with the command: 1221 1222 echo 'level <level>' > /proc/acpi/ibm/fan 1223 1224 Where <level> is an integer from 0 to 7, or one of the words "auto" or 1225 "full-speed" (without the quotes). Not all ThinkPads support the "auto" 1226 and "full-speed" levels. The driver accepts "disengaged" as an alias for 1227 "full-speed", and reports it as "disengaged" for backwards 1228 compatibility. 1229 1230 On the X31 and X40 (and ONLY on those models), the fan speed can be 1231 controlled to a certain degree. Once the fan is running, it can be 1232 forced to run faster or slower with the following command: 1233 1234 echo 'speed <speed>' > /proc/acpi/ibm/fan 1235 1236 The sustainable range of fan speeds on the X40 appears to be from about 1237 3700 to about 7350. Values outside this range either do not have any 1238 effect or the fan speed eventually settles somewhere in that range. The 1239 fan cannot be stopped or started with this command. This functionality 1240 is incomplete, and not available through the sysfs interface. 1241 1242 To program the safety watchdog, use the "watchdog" command. 1243 1244 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan 1245 1246 If you want to disable the watchdog, use 0 as the interval. 1247 1248 Sysfs notes: 1249 1250 The sysfs interface follows the hwmon subsystem guidelines for the most 1251 part, and the exception is the fan safety watchdog. 1252 1253 Writes to any of the sysfs attributes may return the EINVAL error if 1254 that operation is not supported in a given ThinkPad or if the parameter 1255 is out-of-bounds, and EPERM if it is forbidden. They may also return 1256 EINTR (interrupted system call), and EIO (I/O error while trying to talk 1257 to the firmware). 1258 1259 Features not yet implemented by the driver return ENOSYS. 1260 1261 hwmon device attribute pwm1_enable: 1262 0: PWM offline (fan is set to full-speed mode) 1263 1: Manual PWM control (use pwm1 to set fan level) 1264 2: Hardware PWM control (EC "auto" mode) 1265 3: reserved (Software PWM control, not implemented yet) 1266 1267 Modes 0 and 2 are not supported by all ThinkPads, and the 1268 driver is not always able to detect this. If it does know a 1269 mode is unsupported, it will return -EINVAL. 1270 1271 hwmon device attribute pwm1: 1272 Fan level, scaled from the firmware values of 0-7 to the hwmon 1273 scale of 0-255. 0 means fan stopped, 255 means highest normal 1274 speed (level 7). 1275 1276 This attribute only commands the fan if pmw1_enable is set to 1 1277 (manual PWM control). 1278 1279 hwmon device attribute fan1_input: 1280 Fan tachometer reading, in RPM. May go stale on certain 1281 ThinkPads while the EC transitions the PWM to offline mode, 1282 which can take up to two minutes. May return rubbish on older 1283 ThinkPads. 1284 1285 hwmon device attribute fan2_input: 1286 Fan tachometer reading, in RPM, for the secondary fan. 1287 Available only on some ThinkPads. If the secondary fan is 1288 not installed, will always read 0. 1289 1290 hwmon driver attribute fan_watchdog: 1291 Fan safety watchdog timer interval, in seconds. Minimum is 1292 1 second, maximum is 120 seconds. 0 disables the watchdog. 1293 1294 To stop the fan: set pwm1 to zero, and pwm1_enable to 1. 1295 1296 To start the fan in a safe mode: set pwm1_enable to 2. If that fails 1297 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255 1298 would be the safest choice, though). 1299 1300 1301 WAN 1302 --- 1303 1304 procfs: /proc/acpi/ibm/wan 1305 sysfs device attribute: wwan_enable (deprecated) 1306 sysfs rfkill class: switch "tpacpi_wwan_sw" 1307 1308 This feature shows the presence and current state of the built-in 1309 Wireless WAN device. 1310 1311 If the ThinkPad supports it, the WWAN state is stored in NVRAM, 1312 so it is kept across reboots and power-off. 1313 1314 It was tested on a Lenovo ThinkPad X60. It should probably work on other 1315 ThinkPad models which come with this module installed. 1316 1317 Procfs notes: 1318 1319 If the W-WAN card is installed, the following commands can be used: 1320 1321 echo enable > /proc/acpi/ibm/wan 1322 echo disable > /proc/acpi/ibm/wan 1323 1324 Sysfs notes: 1325 1326 If the W-WAN card is installed, it can be enabled / 1327 disabled through the "wwan_enable" thinkpad-acpi device 1328 attribute, and its current status can also be queried. 1329 1330 enable: 1331 0: disables WWAN card / WWAN card is disabled 1332 1: enables WWAN card / WWAN card is enabled. 1333 1334 Note: this interface has been superseded by the generic rfkill 1335 class. It has been deprecated, and it will be removed in year 1336 2010. 1337 1338 rfkill controller switch "tpacpi_wwan_sw": refer to 1339 Documentation/rfkill.txt for details. 1340 1341 1342 EXPERIMENTAL: UWB 1343 ----------------- 1344 1345 This feature is considered EXPERIMENTAL because it has not been extensively 1346 tested and validated in various ThinkPad models yet. The feature may not 1347 work as expected. USE WITH CAUTION! To use this feature, you need to supply 1348 the experimental=1 parameter when loading the module. 1349 1350 sysfs rfkill class: switch "tpacpi_uwb_sw" 1351 1352 This feature exports an rfkill controller for the UWB device, if one is 1353 present and enabled in the BIOS. 1354 1355 Sysfs notes: 1356 1357 rfkill controller switch "tpacpi_uwb_sw": refer to 1358 Documentation/rfkill.txt for details. 1359 1360 Adaptive keyboard 1361 ----------------- 1362 1363 sysfs device attribute: adaptive_kbd_mode 1364 1365 This sysfs attribute controls the keyboard "face" that will be shown on the 1366 Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read 1367 and set. 1368 1369 1 = Home mode 1370 2 = Web-browser mode 1371 3 = Web-conference mode 1372 4 = Function mode 1373 5 = Layflat mode 1374 1375 For more details about which buttons will appear depending on the mode, please 1376 review the laptop's user guide: 1377 http://www.lenovo.com/shop/americas/content/user_guides/x1carbon_2_ug_en.pdf 1378 1379 Multiple Commands, Module Parameters 1380 ------------------------------------ 1381 1382 Multiple commands can be written to the proc files in one shot by 1383 separating them with commas, for example: 1384 1385 echo enable,0xffff > /proc/acpi/ibm/hotkey 1386 echo lcd_disable,crt_enable > /proc/acpi/ibm/video 1387 1388 Commands can also be specified when loading the thinkpad-acpi module, 1389 for example: 1390 1391 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable 1392 1393 1394 Enabling debugging output 1395 ------------------------- 1396 1397 The module takes a debug parameter which can be used to selectively 1398 enable various classes of debugging output, for example: 1399 1400 modprobe thinkpad_acpi debug=0xffff 1401 1402 will enable all debugging output classes. It takes a bitmask, so 1403 to enable more than one output class, just add their values. 1404 1405 Debug bitmask Description 1406 0x8000 Disclose PID of userspace programs 1407 accessing some functions of the driver 1408 0x0001 Initialization and probing 1409 0x0002 Removal 1410 0x0004 RF Transmitter control (RFKILL) 1411 (bluetooth, WWAN, UWB...) 1412 0x0008 HKEY event interface, hotkeys 1413 0x0010 Fan control 1414 0x0020 Backlight brightness 1415 0x0040 Audio mixer/volume control 1416 1417 There is also a kernel build option to enable more debugging 1418 information, which may be necessary to debug driver problems. 1419 1420 The level of debugging information output by the driver can be changed 1421 at runtime through sysfs, using the driver attribute debug_level. The 1422 attribute takes the same bitmask as the debug module parameter above. 1423 1424 1425 Force loading of module 1426 ----------------------- 1427 1428 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify 1429 the module parameter force_load=1. Regardless of whether this works or 1430 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report. 1431 1432 1433 Sysfs interface changelog: 1434 1435 0x000100: Initial sysfs support, as a single platform driver and 1436 device. 1437 0x000200: Hot key support for 32 hot keys, and radio slider switch 1438 support. 1439 0x010000: Hot keys are now handled by default over the input 1440 layer, the radio switch generates input event EV_RADIO, 1441 and the driver enables hot key handling by default in 1442 the firmware. 1443 1444 0x020000: ABI fix: added a separate hwmon platform device and 1445 driver, which must be located by name (thinkpad) 1446 and the hwmon class for libsensors4 (lm-sensors 3) 1447 compatibility. Moved all hwmon attributes to this 1448 new platform device. 1449 1450 0x020100: Marker for thinkpad-acpi with hot key NVRAM polling 1451 support. If you must, use it to know you should not 1452 start a userspace NVRAM poller (allows to detect when 1453 NVRAM is compiled out by the user because it is 1454 unneeded/undesired in the first place). 1455 0x020101: Marker for thinkpad-acpi with hot key NVRAM polling 1456 and proper hotkey_mask semantics (version 8 of the 1457 NVRAM polling patch). Some development snapshots of 1458 0.18 had an earlier version that did strange things 1459 to hotkey_mask. 1460 1461 0x020200: Add poll()/select() support to the following attributes: 1462 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason 1463 1464 0x020300: hotkey enable/disable support removed, attributes 1465 hotkey_bios_enabled and hotkey_enable deprecated and 1466 marked for removal. 1467 1468 0x020400: Marker for 16 LEDs support. Also, LEDs that are known 1469 to not exist in a given model are not registered with 1470 the LED sysfs class anymore. 1471 1472 0x020500: Updated hotkey driver, hotkey_mask is always available 1473 and it is always able to disable hot keys. Very old 1474 thinkpads are properly supported. hotkey_bios_mask 1475 is deprecated and marked for removal. 1476 1477 0x020600: Marker for backlight change event support. 1478 1479 0x020700: Support for mute-only mixers. 1480 Volume control in read-only mode by default. 1481 Marker for ALSA mixer support. 1482 1483 0x030000: Thermal and fan sysfs attributes were moved to the hwmon 1484 device instead of being attached to the backing platform 1485 device.