1=========================== 2ThinkPad ACPI Extras Driver 3=========================== 4 5Version 0.25 6 7October 16th, 2013 8 9- Borislav Deianov <borislav@users.sf.net> 10- Henrique de Moraes Holschuh <hmh@hmh.eng.br> 11 12http://ibm-acpi.sf.net/ 13 14This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It 15supports various features of these laptops which are accessible 16through the ACPI and ACPI EC framework, but not otherwise fully 17supported by the generic Linux ACPI drivers. 18 19This driver used to be named ibm-acpi until kernel 2.6.21 and release 200.13-20070314. It used to be in the drivers/acpi tree, but it was 21moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel 222.6.22, and release 0.14. It was moved to drivers/platform/x86 for 23kernel 2.6.29 and release 0.22. 24 25The driver is named "thinkpad-acpi". In some places, like module 26names and log messages, "thinkpad_acpi" is used because of userspace 27issues. 28 29"tpacpi" is used as a shorthand where "thinkpad-acpi" would be too 30long due to length limitations on some Linux kernel versions. 31 32Status 33------ 34 35The features currently supported are the following (see below for 36detailed description): 37 38 - Fn key combinations 39 - Bluetooth enable and disable 40 - video output switching, expansion control 41 - ThinkLight on and off 42 - CMOS/UCMS control 43 - LED control 44 - ACPI sounds 45 - temperature sensors 46 - Experimental: embedded controller register dump 47 - LCD brightness control 48 - Volume control 49 - Fan control and monitoring: fan speed, fan enable/disable 50 - WAN enable and disable 51 - UWB enable and disable 52 - LCD Shadow (PrivacyGuard) enable and disable 53 - Lap mode sensor 54 - Setting keyboard language 55 - WWAN Antenna type 56 - Auxmac 57 58A compatibility table by model and feature is maintained on the web 59site, http://ibm-acpi.sf.net/. I appreciate any success or failure 60reports, especially if they add to or correct the compatibility table. 61Please include the following information in your report: 62 63 - ThinkPad model name 64 - a copy of your ACPI tables, using the "acpidump" utility 65 - a copy of the output of dmidecode, with serial numbers 66 and UUIDs masked off 67 - which driver features work and which don't 68 - the observed behavior of non-working features 69 70Any other comments or patches are also more than welcome. 71 72 73Installation 74------------ 75 76If you are compiling this driver as included in the Linux kernel 77sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. 78It is located on the menu path: "Device Drivers" -> "X86 Platform 79Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". 80 81 82Features 83-------- 84 85The driver exports two different interfaces to userspace, which can be 86used to access the features it provides. One is a legacy procfs-based 87interface, which will be removed at some time in the future. The other 88is a new sysfs-based interface which is not complete yet. 89 90The procfs interface creates the /proc/acpi/ibm directory. There is a 91file under that directory for each feature it supports. The procfs 92interface is mostly frozen, and will change very little if at all: it 93will not be extended to add any new functionality in the driver, instead 94all new functionality will be implemented on the sysfs interface. 95 96The sysfs interface tries to blend in the generic Linux sysfs subsystems 97and classes as much as possible. Since some of these subsystems are not 98yet ready or stabilized, it is expected that this interface will change, 99and any and all userspace programs must deal with it. 100 101 102Notes about the sysfs interface 103^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 104 105Unlike what was done with the procfs interface, correctness when talking 106to the sysfs interfaces will be enforced, as will correctness in the 107thinkpad-acpi's implementation of sysfs interfaces. 108 109Also, any bugs in the thinkpad-acpi sysfs driver code or in the 110thinkpad-acpi's implementation of the sysfs interfaces will be fixed for 111maximum correctness, even if that means changing an interface in 112non-compatible ways. As these interfaces mature both in the kernel and 113in thinkpad-acpi, such changes should become quite rare. 114 115Applications interfacing to the thinkpad-acpi sysfs interfaces must 116follow all sysfs guidelines and correctly process all errors (the sysfs 117interface makes extensive use of errors). File descriptors and open / 118close operations to the sysfs inodes must also be properly implemented. 119 120The version of thinkpad-acpi's sysfs interface is exported by the driver 121as a driver attribute (see below). 122 123Sysfs driver attributes are on the driver's sysfs attribute space, 124for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and 125/sys/bus/platform/drivers/thinkpad_hwmon/ 126 127Sysfs device attributes are on the thinkpad_acpi device sysfs attribute 128space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. 129 130Sysfs device attributes for the sensors and fan are on the 131thinkpad_hwmon device's sysfs attribute space, but you should locate it 132looking for a hwmon device with the name attribute of "thinkpad", or 133better yet, through libsensors. For 4.14+ sysfs attributes were moved to the 134hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or 135/sys/class/hwmon/hwmon?). 136 137Driver version 138-------------- 139 140procfs: /proc/acpi/ibm/driver 141 142sysfs driver attribute: version 143 144The driver name and version. No commands can be written to this file. 145 146 147Sysfs interface version 148----------------------- 149 150sysfs driver attribute: interface_version 151 152Version of the thinkpad-acpi sysfs interface, as an unsigned long 153(output in hex format: 0xAAAABBCC), where: 154 155 AAAA 156 - major revision 157 BB 158 - minor revision 159 CC 160 - bugfix revision 161 162The sysfs interface version changelog for the driver can be found at the 163end of this document. Changes to the sysfs interface done by the kernel 164subsystems are not documented here, nor are they tracked by this 165attribute. 166 167Changes to the thinkpad-acpi sysfs interface are only considered 168non-experimental when they are submitted to Linux mainline, at which 169point the changes in this interface are documented and interface_version 170may be updated. If you are using any thinkpad-acpi features not yet 171sent to mainline for merging, you do so on your own risk: these features 172may disappear, or be implemented in a different and incompatible way by 173the time they are merged in Linux mainline. 174 175Changes that are backwards-compatible by nature (e.g. the addition of 176attributes that do not change the way the other attributes work) do not 177always warrant an update of interface_version. Therefore, one must 178expect that an attribute might not be there, and deal with it properly 179(an attribute not being there *is* a valid way to make it clear that a 180feature is not available in sysfs). 181 182 183Hot keys 184-------- 185 186procfs: /proc/acpi/ibm/hotkey 187 188sysfs device attribute: hotkey_* 189 190In a ThinkPad, the ACPI HKEY handler is responsible for communicating 191some important events and also keyboard hot key presses to the operating 192system. Enabling the hotkey functionality of thinkpad-acpi signals the 193firmware that such a driver is present, and modifies how the ThinkPad 194firmware will behave in many situations. 195 196The driver enables the HKEY ("hot key") event reporting automatically 197when loaded, and disables it when it is removed. 198 199The driver will report HKEY events in the following format:: 200 201 ibm/hotkey HKEY 00000080 0000xxxx 202 203Some of these events refer to hot key presses, but not all of them. 204 205The driver will generate events over the input layer for hot keys and 206radio switches, and over the ACPI netlink layer for other events. The 207input layer support accepts the standard IOCTLs to remap the keycodes 208assigned to each hot key. 209 210The hot key bit mask allows some control over which hot keys generate 211events. If a key is "masked" (bit set to 0 in the mask), the firmware 212will handle it. If it is "unmasked", it signals the firmware that 213thinkpad-acpi would prefer to handle it, if the firmware would be so 214kind to allow it (and it often doesn't!). 215 216Not all bits in the mask can be modified. Not all bits that can be 217modified do anything. Not all hot keys can be individually controlled 218by the mask. Some models do not support the mask at all. The behaviour 219of the mask is, therefore, highly dependent on the ThinkPad model. 220 221The driver will filter out any unmasked hotkeys, so even if the firmware 222doesn't allow disabling an specific hotkey, the driver will not report 223events for unmasked hotkeys. 224 225Note that unmasking some keys prevents their default behavior. For 226example, if Fn+F5 is unmasked, that key will no longer enable/disable 227Bluetooth by itself in firmware. 228 229Note also that not all Fn key combinations are supported through ACPI 230depending on the ThinkPad model and firmware version. On those 231ThinkPads, it is still possible to support some extra hotkeys by 232polling the "CMOS NVRAM" at least 10 times per second. The driver 233attempts to enables this functionality automatically when required. 234 235procfs notes 236^^^^^^^^^^^^ 237 238The following commands can be written to the /proc/acpi/ibm/hotkey file:: 239 240 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys 241 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys 242 ... any other 8-hex-digit mask ... 243 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask 244 245The following commands have been deprecated and will cause the kernel 246to log a warning:: 247 248 echo enable > /proc/acpi/ibm/hotkey -- does nothing 249 echo disable > /proc/acpi/ibm/hotkey -- returns an error 250 251The procfs interface does not support NVRAM polling control. So as to 252maintain maximum bug-to-bug compatibility, it does not report any masks, 253nor does it allow one to manipulate the hot key mask when the firmware 254does not support masks at all, even if NVRAM polling is in use. 255 256sysfs notes 257^^^^^^^^^^^ 258 259 hotkey_bios_enabled: 260 DEPRECATED, WILL BE REMOVED SOON. 261 262 Returns 0. 263 264 hotkey_bios_mask: 265 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE. 266 267 Returns the hot keys mask when thinkpad-acpi was loaded. 268 Upon module unload, the hot keys mask will be restored 269 to this value. This is always 0x80c, because those are 270 the hotkeys that were supported by ancient firmware 271 without mask support. 272 273 hotkey_enable: 274 DEPRECATED, WILL BE REMOVED SOON. 275 276 0: returns -EPERM 277 1: does nothing 278 279 hotkey_mask: 280 bit mask to enable reporting (and depending on 281 the firmware, ACPI event generation) for each hot key 282 (see above). Returns the current status of the hot keys 283 mask, and allows one to modify it. 284 285 hotkey_all_mask: 286 bit mask that should enable event reporting for all 287 supported hot keys, when echoed to hotkey_mask above. 288 Unless you know which events need to be handled 289 passively (because the firmware *will* handle them 290 anyway), do *not* use hotkey_all_mask. Use 291 hotkey_recommended_mask, instead. You have been warned. 292 293 hotkey_recommended_mask: 294 bit mask that should enable event reporting for all 295 supported hot keys, except those which are always 296 handled by the firmware anyway. Echo it to 297 hotkey_mask above, to use. This is the default mask 298 used by the driver. 299 300 hotkey_source_mask: 301 bit mask that selects which hot keys will the driver 302 poll the NVRAM for. This is auto-detected by the driver 303 based on the capabilities reported by the ACPI firmware, 304 but it can be overridden at runtime. 305 306 Hot keys whose bits are set in hotkey_source_mask are 307 polled for in NVRAM, and reported as hotkey events if 308 enabled in hotkey_mask. Only a few hot keys are 309 available through CMOS NVRAM polling. 310 311 Warning: when in NVRAM mode, the volume up/down/mute 312 keys are synthesized according to changes in the mixer, 313 which uses a single volume up or volume down hotkey 314 press to unmute, as per the ThinkPad volume mixer user 315 interface. When in ACPI event mode, volume up/down/mute 316 events are reported by the firmware and can behave 317 differently (and that behaviour changes with firmware 318 version -- not just with firmware models -- as well as 319 OSI(Linux) state). 320 321 hotkey_poll_freq: 322 frequency in Hz for hot key polling. It must be between 323 0 and 25 Hz. Polling is only carried out when strictly 324 needed. 325 326 Setting hotkey_poll_freq to zero disables polling, and 327 will cause hot key presses that require NVRAM polling 328 to never be reported. 329 330 Setting hotkey_poll_freq too low may cause repeated 331 pressings of the same hot key to be misreported as a 332 single key press, or to not even be detected at all. 333 The recommended polling frequency is 10Hz. 334 335 hotkey_radio_sw: 336 If the ThinkPad has a hardware radio switch, this 337 attribute will read 0 if the switch is in the "radios 338 disabled" position, and 1 if the switch is in the 339 "radios enabled" position. 340 341 This attribute has poll()/select() support. 342 343 hotkey_tablet_mode: 344 If the ThinkPad has tablet capabilities, this attribute 345 will read 0 if the ThinkPad is in normal mode, and 346 1 if the ThinkPad is in tablet mode. 347 348 This attribute has poll()/select() support. 349 350 wakeup_reason: 351 Set to 1 if the system is waking up because the user 352 requested a bay ejection. Set to 2 if the system is 353 waking up because the user requested the system to 354 undock. Set to zero for normal wake-ups or wake-ups 355 due to unknown reasons. 356 357 This attribute has poll()/select() support. 358 359 wakeup_hotunplug_complete: 360 Set to 1 if the system was waken up because of an 361 undock or bay ejection request, and that request 362 was successfully completed. At this point, it might 363 be useful to send the system back to sleep, at the 364 user's choice. Refer to HKEY events 0x4003 and 365 0x3003, below. 366 367 This attribute has poll()/select() support. 368 369input layer notes 370^^^^^^^^^^^^^^^^^ 371 372A Hot key is mapped to a single input layer EV_KEY event, possibly 373followed by an EV_MSC MSC_SCAN event that shall contain that key's scan 374code. An EV_SYN event will always be generated to mark the end of the 375event block. 376 377Do not use the EV_MSC MSC_SCAN events to process keys. They are to be 378used as a helper to remap keys, only. They are particularly useful when 379remapping KEY_UNKNOWN keys. 380 381The events are available in an input device, with the following id: 382 383 ============== ============================== 384 Bus BUS_HOST 385 vendor 0x1014 (PCI_VENDOR_ID_IBM) or 386 0x17aa (PCI_VENDOR_ID_LENOVO) 387 product 0x5054 ("TP") 388 version 0x4101 389 ============== ============================== 390 391The version will have its LSB incremented if the keymap changes in a 392backwards-compatible way. The MSB shall always be 0x41 for this input 393device. If the MSB is not 0x41, do not use the device as described in 394this section, as it is either something else (e.g. another input device 395exported by a thinkpad driver, such as HDAPS) or its functionality has 396been changed in a non-backwards compatible way. 397 398Adding other event types for other functionalities shall be considered a 399backwards-compatible change for this input device. 400 401Thinkpad-acpi Hot Key event map (version 0x4101): 402 403======= ======= ============== ============================================== 404ACPI Scan 405event code Key Notes 406======= ======= ============== ============================================== 4070x1001 0x00 FN+F1 - 408 4090x1002 0x01 FN+F2 IBM: battery (rare) 410 Lenovo: Screen lock 411 4120x1003 0x02 FN+F3 Many IBM models always report 413 this hot key, even with hot keys 414 disabled or with Fn+F3 masked 415 off 416 IBM: screen lock, often turns 417 off the ThinkLight as side-effect 418 Lenovo: battery 419 4200x1004 0x03 FN+F4 Sleep button (ACPI sleep button 421 semantics, i.e. sleep-to-RAM). 422 It always generates some kind 423 of event, either the hot key 424 event or an ACPI sleep button 425 event. The firmware may 426 refuse to generate further FN+F4 427 key presses until a S3 or S4 ACPI 428 sleep cycle is performed or some 429 time passes. 430 4310x1005 0x04 FN+F5 Radio. Enables/disables 432 the internal Bluetooth hardware 433 and W-WAN card if left in control 434 of the firmware. Does not affect 435 the WLAN card. 436 Should be used to turn on/off all 437 radios (Bluetooth+W-WAN+WLAN), 438 really. 439 4400x1006 0x05 FN+F6 - 441 4420x1007 0x06 FN+F7 Video output cycle. 443 Do you feel lucky today? 444 4450x1008 0x07 FN+F8 IBM: toggle screen expand 446 Lenovo: configure UltraNav, 447 or toggle screen expand 448 4490x1009 0x08 FN+F9 - 450 451... ... ... ... 452 4530x100B 0x0A FN+F11 - 454 4550x100C 0x0B FN+F12 Sleep to disk. You are always 456 supposed to handle it yourself, 457 either through the ACPI event, 458 or through a hotkey event. 459 The firmware may refuse to 460 generate further FN+F12 key 461 press events until a S3 or S4 462 ACPI sleep cycle is performed, 463 or some time passes. 464 4650x100D 0x0C FN+BACKSPACE - 4660x100E 0x0D FN+INSERT - 4670x100F 0x0E FN+DELETE - 468 4690x1010 0x0F FN+HOME Brightness up. This key is 470 always handled by the firmware 471 in IBM ThinkPads, even when 472 unmasked. Just leave it alone. 473 For Lenovo ThinkPads with a new 474 BIOS, it has to be handled either 475 by the ACPI OSI, or by userspace. 476 The driver does the right thing, 477 never mess with this. 4780x1011 0x10 FN+END Brightness down. See brightness 479 up for details. 480 4810x1012 0x11 FN+PGUP ThinkLight toggle. This key is 482 always handled by the firmware, 483 even when unmasked. 484 4850x1013 0x12 FN+PGDOWN - 486 4870x1014 0x13 FN+SPACE Zoom key 488 4890x1015 0x14 VOLUME UP Internal mixer volume up. This 490 key is always handled by the 491 firmware, even when unmasked. 492 NOTE: Lenovo seems to be changing 493 this. 4940x1016 0x15 VOLUME DOWN Internal mixer volume up. This 495 key is always handled by the 496 firmware, even when unmasked. 497 NOTE: Lenovo seems to be changing 498 this. 4990x1017 0x16 MUTE Mute internal mixer. This 500 key is always handled by the 501 firmware, even when unmasked. 502 5030x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key 504 5050x1019 0x18 unknown 506 507... ... ... 508 5090x1020 0x1F unknown 510======= ======= ============== ============================================== 511 512The ThinkPad firmware does not allow one to differentiate when most hot 513keys are pressed or released (either that, or we don't know how to, yet). 514For these keys, the driver generates a set of events for a key press and 515immediately issues the same set of events for a key release. It is 516unknown by the driver if the ThinkPad firmware triggered these events on 517hot key press or release, but the firmware will do it for either one, not 518both. 519 520If a key is mapped to KEY_RESERVED, it generates no input events at all. 521If a key is mapped to KEY_UNKNOWN, it generates an input event that 522includes an scan code. If a key is mapped to anything else, it will 523generate input device EV_KEY events. 524 525In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW 526events for switches: 527 528============== ============================================== 529SW_RFKILL_ALL T60 and later hardware rfkill rocker switch 530SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A 531============== ============================================== 532 533Non hotkey ACPI HKEY event map 534------------------------------ 535 536Events that are never propagated by the driver: 537 538====== ================================================== 5390x2304 System is waking up from suspend to undock 5400x2305 System is waking up from suspend to eject bay 5410x2404 System is waking up from hibernation to undock 5420x2405 System is waking up from hibernation to eject bay 5430x5001 Lid closed 5440x5002 Lid opened 5450x5009 Tablet swivel: switched to tablet mode 5460x500A Tablet swivel: switched to normal mode 5470x5010 Brightness level changed/control event 5480x6000 KEYBOARD: Numlock key pressed 5490x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) 5500x7000 Radio Switch may have changed state 551====== ================================================== 552 553 554Events that are propagated by the driver to userspace: 555 556====== ===================================================== 5570x2313 ALARM: System is waking up from suspend because 558 the battery is nearly empty 5590x2413 ALARM: System is waking up from hibernation because 560 the battery is nearly empty 5610x3003 Bay ejection (see 0x2x05) complete, can sleep again 5620x3006 Bay hotplug request (hint to power up SATA link when 563 the optical drive tray is ejected) 5640x4003 Undocked (see 0x2x04), can sleep again 5650x4010 Docked into hotplug port replicator (non-ACPI dock) 5660x4011 Undocked from hotplug port replicator (non-ACPI dock) 5670x500B Tablet pen inserted into its storage bay 5680x500C Tablet pen removed from its storage bay 5690x6011 ALARM: battery is too hot 5700x6012 ALARM: battery is extremely hot 5710x6021 ALARM: a sensor is too hot 5720x6022 ALARM: a sensor is extremely hot 5730x6030 System thermal table changed 5740x6032 Thermal Control command set completion (DYTC, Windows) 5750x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) 5760x60C0 X1 Yoga 2016, Tablet mode status changed 5770x60F0 Thermal Transformation changed (GMTS, Windows) 578====== ===================================================== 579 580Battery nearly empty alarms are a last resort attempt to get the 581operating system to hibernate or shutdown cleanly (0x2313), or shutdown 582cleanly (0x2413) before power is lost. They must be acted upon, as the 583wake up caused by the firmware will have negated most safety nets... 584 585When any of the "too hot" alarms happen, according to Lenovo the user 586should suspend or hibernate the laptop (and in the case of battery 587alarms, unplug the AC adapter) to let it cool down. These alarms do 588signal that something is wrong, they should never happen on normal 589operating conditions. 590 591The "extremely hot" alarms are emergencies. According to Lenovo, the 592operating system is to force either an immediate suspend or hibernate 593cycle, or a system shutdown. Obviously, something is very wrong if this 594happens. 595 596 597Brightness hotkey notes 598^^^^^^^^^^^^^^^^^^^^^^^ 599 600Don't mess with the brightness hotkeys in a Thinkpad. If you want 601notifications for OSD, use the sysfs backlight class event support. 602 603The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events 604automatically for the cases were userspace has to do something to 605implement brightness changes. When you override these events, you will 606either fail to handle properly the ThinkPads that require explicit 607action to change backlight brightness, or the ThinkPads that require 608that no action be taken to work properly. 609 610 611Bluetooth 612--------- 613 614procfs: /proc/acpi/ibm/bluetooth 615 616sysfs device attribute: bluetooth_enable (deprecated) 617 618sysfs rfkill class: switch "tpacpi_bluetooth_sw" 619 620This feature shows the presence and current state of a ThinkPad 621Bluetooth device in the internal ThinkPad CDC slot. 622 623If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, 624so it is kept across reboots and power-off. 625 626Procfs notes 627^^^^^^^^^^^^ 628 629If Bluetooth is installed, the following commands can be used:: 630 631 echo enable > /proc/acpi/ibm/bluetooth 632 echo disable > /proc/acpi/ibm/bluetooth 633 634Sysfs notes 635^^^^^^^^^^^ 636 637 If the Bluetooth CDC card is installed, it can be enabled / 638 disabled through the "bluetooth_enable" thinkpad-acpi device 639 attribute, and its current status can also be queried. 640 641 enable: 642 643 - 0: disables Bluetooth / Bluetooth is disabled 644 - 1: enables Bluetooth / Bluetooth is enabled. 645 646 Note: this interface has been superseded by the generic rfkill 647 class. It has been deprecated, and it will be removed in year 648 2010. 649 650 rfkill controller switch "tpacpi_bluetooth_sw": refer to 651 Documentation/driver-api/rfkill.rst for details. 652 653 654Video output control -- /proc/acpi/ibm/video 655-------------------------------------------- 656 657This feature allows control over the devices used for video output - 658LCD, CRT or DVI (if available). The following commands are available:: 659 660 echo lcd_enable > /proc/acpi/ibm/video 661 echo lcd_disable > /proc/acpi/ibm/video 662 echo crt_enable > /proc/acpi/ibm/video 663 echo crt_disable > /proc/acpi/ibm/video 664 echo dvi_enable > /proc/acpi/ibm/video 665 echo dvi_disable > /proc/acpi/ibm/video 666 echo auto_enable > /proc/acpi/ibm/video 667 echo auto_disable > /proc/acpi/ibm/video 668 echo expand_toggle > /proc/acpi/ibm/video 669 echo video_switch > /proc/acpi/ibm/video 670 671NOTE: 672 Access to this feature is restricted to processes owning the 673 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly 674 enough with some versions of X.org to crash it. 675 676Each video output device can be enabled or disabled individually. 677Reading /proc/acpi/ibm/video shows the status of each device. 678 679Automatic video switching can be enabled or disabled. When automatic 680video switching is enabled, certain events (e.g. opening the lid, 681docking or undocking) cause the video output device to change 682automatically. While this can be useful, it also causes flickering 683and, on the X40, video corruption. By disabling automatic switching, 684the flickering or video corruption can be avoided. 685 686The video_switch command cycles through the available video outputs 687(it simulates the behavior of Fn-F7). 688 689Video expansion can be toggled through this feature. This controls 690whether the display is expanded to fill the entire LCD screen when a 691mode with less than full resolution is used. Note that the current 692video expansion status cannot be determined through this feature. 693 694Note that on many models (particularly those using Radeon graphics 695chips) the X driver configures the video card in a way which prevents 696Fn-F7 from working. This also disables the video output switching 697features of this driver, as it uses the same ACPI methods as 698Fn-F7. Video switching on the console should still work. 699 700UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 701 702 703ThinkLight control 704------------------ 705 706procfs: /proc/acpi/ibm/light 707 708sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED 709 710procfs notes 711^^^^^^^^^^^^ 712 713The ThinkLight status can be read and set through the procfs interface. A 714few models which do not make the status available will show the ThinkLight 715status as "unknown". The available commands are:: 716 717 echo on > /proc/acpi/ibm/light 718 echo off > /proc/acpi/ibm/light 719 720sysfs notes 721^^^^^^^^^^^ 722 723The ThinkLight sysfs interface is documented by the LED class 724documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name 725is "tpacpi::thinklight". 726 727Due to limitations in the sysfs LED class, if the status of the ThinkLight 728cannot be read or if it is unknown, thinkpad-acpi will report it as "off". 729It is impossible to know if the status returned through sysfs is valid. 730 731 732CMOS/UCMS control 733----------------- 734 735procfs: /proc/acpi/ibm/cmos 736 737sysfs device attribute: cmos_command 738 739This feature is mostly used internally by the ACPI firmware to keep the legacy 740CMOS NVRAM bits in sync with the current machine state, and to record this 741state so that the ThinkPad will retain such settings across reboots. 742 743Some of these commands actually perform actions in some ThinkPad models, but 744this is expected to disappear more and more in newer models. As an example, in 745a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for 746real, but commands 0 to 2 don't control the mixer anymore (they have been 747phased out) and just update the NVRAM. 748 749The range of valid cmos command numbers is 0 to 21, but not all have an 750effect and the behavior varies from model to model. Here is the behavior 751on the X40 (tpb is the ThinkPad Buttons utility): 752 753 - 0 - Related to "Volume down" key press 754 - 1 - Related to "Volume up" key press 755 - 2 - Related to "Mute on" key press 756 - 3 - Related to "Access IBM" key press 757 - 4 - Related to "LCD brightness up" key press 758 - 5 - Related to "LCD brightness down" key press 759 - 11 - Related to "toggle screen expansion" key press/function 760 - 12 - Related to "ThinkLight on" 761 - 13 - Related to "ThinkLight off" 762 - 14 - Related to "ThinkLight" key press (toggle ThinkLight) 763 764The cmos command interface is prone to firmware split-brain problems, as 765in newer ThinkPads it is just a compatibility layer. Do not use it, it is 766exported just as a debug tool. 767 768 769LED control 770----------- 771 772procfs: /proc/acpi/ibm/led 773sysfs attributes: as per LED class, see below for names 774 775Some of the LED indicators can be controlled through this feature. On 776some older ThinkPad models, it is possible to query the status of the 777LED indicators as well. Newer ThinkPads cannot query the real status 778of the LED indicators. 779 780Because misuse of the LEDs could induce an unaware user to perform 781dangerous actions (like undocking or ejecting a bay device while the 782buses are still active), or mask an important alarm (such as a nearly 783empty battery, or a broken battery), access to most LEDs is 784restricted. 785 786Unrestricted access to all LEDs requires that thinkpad-acpi be 787compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. 788Distributions must never enable this option. Individual users that 789are aware of the consequences are welcome to enabling it. 790 791Audio mute and microphone mute LEDs are supported, but currently not 792visible to userspace. They are used by the snd-hda-intel audio driver. 793 794procfs notes 795^^^^^^^^^^^^ 796 797The available commands are:: 798 799 echo '<LED number> on' >/proc/acpi/ibm/led 800 echo '<LED number> off' >/proc/acpi/ibm/led 801 echo '<LED number> blink' >/proc/acpi/ibm/led 802 803The <LED number> range is 0 to 15. The set of LEDs that can be 804controlled varies from model to model. Here is the common ThinkPad 805mapping: 806 807 - 0 - power 808 - 1 - battery (orange) 809 - 2 - battery (green) 810 - 3 - UltraBase/dock 811 - 4 - UltraBay 812 - 5 - UltraBase battery slot 813 - 6 - (unknown) 814 - 7 - standby 815 - 8 - dock status 1 816 - 9 - dock status 2 817 - 10, 11 - (unknown) 818 - 12 - thinkvantage 819 - 13, 14, 15 - (unknown) 820 821All of the above can be turned on and off and can be made to blink. 822 823sysfs notes 824^^^^^^^^^^^ 825 826The ThinkPad LED sysfs interface is described in detail by the LED class 827documentation, in Documentation/leds/leds-class.rst. 828 829The LEDs are named (in LED ID order, from 0 to 12): 830"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", 831"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", 832"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", 833"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", 834"tpacpi::thinkvantage". 835 836Due to limitations in the sysfs LED class, if the status of the LED 837indicators cannot be read due to an error, thinkpad-acpi will report it as 838a brightness of zero (same as LED off). 839 840If the thinkpad firmware doesn't support reading the current status, 841trying to read the current LED brightness will just return whatever 842brightness was last written to that attribute. 843 844These LEDs can blink using hardware acceleration. To request that a 845ThinkPad indicator LED should blink in hardware accelerated mode, use the 846"timer" trigger, and leave the delay_on and delay_off parameters set to 847zero (to request hardware acceleration autodetection). 848 849LEDs that are known not to exist in a given ThinkPad model are not 850made available through the sysfs interface. If you have a dock and you 851notice there are LEDs listed for your ThinkPad that do not exist (and 852are not in the dock), or if you notice that there are missing LEDs, 853a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. 854 855 856ACPI sounds -- /proc/acpi/ibm/beep 857---------------------------------- 858 859The BEEP method is used internally by the ACPI firmware to provide 860audible alerts in various situations. This feature allows the same 861sounds to be triggered manually. 862 863The commands are non-negative integer numbers:: 864 865 echo <number> >/proc/acpi/ibm/beep 866 867The valid <number> range is 0 to 17. Not all numbers trigger sounds 868and the sounds vary from model to model. Here is the behavior on the 869X40: 870 871 - 0 - stop a sound in progress (but use 17 to stop 16) 872 - 2 - two beeps, pause, third beep ("low battery") 873 - 3 - single beep 874 - 4 - high, followed by low-pitched beep ("unable") 875 - 5 - single beep 876 - 6 - very high, followed by high-pitched beep ("AC/DC") 877 - 7 - high-pitched beep 878 - 9 - three short beeps 879 - 10 - very long beep 880 - 12 - low-pitched beep 881 - 15 - three high-pitched beeps repeating constantly, stop with 0 882 - 16 - one medium-pitched beep repeating constantly, stop with 17 883 - 17 - stop 16 884 885 886Temperature sensors 887------------------- 888 889procfs: /proc/acpi/ibm/thermal 890 891sysfs device attributes: (hwmon "thinkpad") temp*_input 892 893Most ThinkPads include six or more separate temperature sensors but only 894expose the CPU temperature through the standard ACPI methods. This 895feature shows readings from up to eight different sensors on older 896ThinkPads, and up to sixteen different sensors on newer ThinkPads. 897 898For example, on the X40, a typical output may be: 899 900temperatures: 901 42 42 45 41 36 -128 33 -128 902 903On the T43/p, a typical output may be: 904 905temperatures: 906 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 907 908The mapping of thermal sensors to physical locations varies depending on 909system-board model (and thus, on ThinkPad model). 910 911https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that 912tries to track down these locations for various models. 913 914Most (newer?) models seem to follow this pattern: 915 916- 1: CPU 917- 2: (depends on model) 918- 3: (depends on model) 919- 4: GPU 920- 5: Main battery: main sensor 921- 6: Bay battery: main sensor 922- 7: Main battery: secondary sensor 923- 8: Bay battery: secondary sensor 924- 9-15: (depends on model) 925 926For the R51 (source: Thomas Gruber): 927 928- 2: Mini-PCI 929- 3: Internal HDD 930 931For the T43, T43/p (source: Shmidoax/Thinkwiki.org) 932https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p 933 934- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp 935- 3: PCMCIA slot 936- 9: MCH (northbridge) to DRAM Bus 937- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI 938 card, under touchpad 939- 11: Power regulator, underside of system board, below F2 key 940 941The A31 has a very atypical layout for the thermal sensors 942(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) 943 944- 1: CPU 945- 2: Main Battery: main sensor 946- 3: Power Converter 947- 4: Bay Battery: main sensor 948- 5: MCH (northbridge) 949- 6: PCMCIA/ambient 950- 7: Main Battery: secondary sensor 951- 8: Bay Battery: secondary sensor 952 953 954Procfs notes 955^^^^^^^^^^^^ 956 957 Readings from sensors that are not available return -128. 958 No commands can be written to this file. 959 960Sysfs notes 961^^^^^^^^^^^ 962 963 Sensors that are not available return the ENXIO error. This 964 status may change at runtime, as there are hotplug thermal 965 sensors, like those inside the batteries and docks. 966 967 thinkpad-acpi thermal sensors are reported through the hwmon 968 subsystem, and follow all of the hwmon guidelines at 969 Documentation/hwmon. 970 971EXPERIMENTAL: Embedded controller register dump 972----------------------------------------------- 973 974This feature is not included in the thinkpad driver anymore. 975Instead the EC can be accessed through /sys/kernel/debug/ec with 976a userspace tool which can be found here: 977ftp://ftp.suse.com/pub/people/trenn/sources/ec 978 979Use it to determine the register holding the fan 980speed on some models. To do that, do the following: 981 982 - make sure the battery is fully charged 983 - make sure the fan is running 984 - use above mentioned tool to read out the EC 985 986Often fan and temperature values vary between 987readings. Since temperatures don't change vary fast, you can take 988several quick dumps to eliminate them. 989 990You can use a similar method to figure out the meaning of other 991embedded controller registers - e.g. make sure nothing else changes 992except the charging or discharging battery to determine which 993registers contain the current battery capacity, etc. If you experiment 994with this, do send me your results (including some complete dumps with 995a description of the conditions when they were taken.) 996 997 998LCD brightness control 999---------------------- 1000 1001procfs: /proc/acpi/ibm/brightness 1002 1003sysfs backlight device "thinkpad_screen" 1004 1005This feature allows software control of the LCD brightness on ThinkPad 1006models which don't have a hardware brightness slider. 1007 1008It has some limitations: the LCD backlight cannot be actually turned 1009on or off by this interface, it just controls the backlight brightness 1010level. 1011 1012On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control 1013has eight brightness levels, ranging from 0 to 7. Some of the levels 1014may not be distinct. Later Lenovo models that implement the ACPI 1015display backlight brightness control methods have 16 levels, ranging 1016from 0 to 15. 1017 1018For IBM ThinkPads, there are two interfaces to the firmware for direct 1019brightness control, EC and UCMS (or CMOS). To select which one should be 1020used, use the brightness_mode module parameter: brightness_mode=1 selects 1021EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC 1022mode with NVRAM backing (so that brightness changes are remembered across 1023shutdown/reboot). 1024 1025The driver tries to select which interface to use from a table of 1026defaults for each ThinkPad model. If it makes a wrong choice, please 1027report this as a bug, so that we can fix it. 1028 1029Lenovo ThinkPads only support brightness_mode=2 (UCMS). 1030 1031When display backlight brightness controls are available through the 1032standard ACPI interface, it is best to use it instead of this direct 1033ThinkPad-specific interface. The driver will disable its native 1034backlight brightness control interface if it detects that the standard 1035ACPI interface is available in the ThinkPad. 1036 1037If you want to use the thinkpad-acpi backlight brightness control 1038instead of the generic ACPI video backlight brightness control for some 1039reason, you should use the acpi_backlight=vendor kernel parameter. 1040 1041The brightness_enable module parameter can be used to control whether 1042the LCD brightness control feature will be enabled when available. 1043brightness_enable=0 forces it to be disabled. brightness_enable=1 1044forces it to be enabled when available, even if the standard ACPI 1045interface is also available. 1046 1047Procfs notes 1048^^^^^^^^^^^^ 1049 1050The available commands are:: 1051 1052 echo up >/proc/acpi/ibm/brightness 1053 echo down >/proc/acpi/ibm/brightness 1054 echo 'level <level>' >/proc/acpi/ibm/brightness 1055 1056Sysfs notes 1057^^^^^^^^^^^ 1058 1059The interface is implemented through the backlight sysfs class, which is 1060poorly documented at this time. 1061 1062Locate the thinkpad_screen device under /sys/class/backlight, and inside 1063it there will be the following attributes: 1064 1065 max_brightness: 1066 Reads the maximum brightness the hardware can be set to. 1067 The minimum is always zero. 1068 1069 actual_brightness: 1070 Reads what brightness the screen is set to at this instant. 1071 1072 brightness: 1073 Writes request the driver to change brightness to the 1074 given value. Reads will tell you what brightness the 1075 driver is trying to set the display to when "power" is set 1076 to zero and the display has not been dimmed by a kernel 1077 power management event. 1078 1079 power: 1080 power management mode, where 0 is "display on", and 1 to 3 1081 will dim the display backlight to brightness level 0 1082 because thinkpad-acpi cannot really turn the backlight 1083 off. Kernel power management events can temporarily 1084 increase the current power management level, i.e. they can 1085 dim the display. 1086 1087 1088WARNING: 1089 1090 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change 1091 interface and the ACPI-based backlight level change interface 1092 (available on newer BIOSes, and driven by the Linux ACPI video driver) 1093 at the same time. The two will interact in bad ways, do funny things, 1094 and maybe reduce the life of the backlight lamps by needlessly kicking 1095 its level up and down at every change. 1096 1097 1098Volume control (Console Audio control) 1099-------------------------------------- 1100 1101procfs: /proc/acpi/ibm/volume 1102 1103ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" 1104 1105NOTE: by default, the volume control interface operates in read-only 1106mode, as it is supposed to be used for on-screen-display purposes. 1107The read/write mode can be enabled through the use of the 1108"volume_control=1" module parameter. 1109 1110NOTE: distros are urged to not enable volume_control by default, this 1111should be done by the local admin only. The ThinkPad UI is for the 1112console audio control to be done through the volume keys only, and for 1113the desktop environment to just provide on-screen-display feedback. 1114Software volume control should be done only in the main AC97/HDA 1115mixer. 1116 1117 1118About the ThinkPad Console Audio control 1119^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1120 1121ThinkPads have a built-in amplifier and muting circuit that drives the 1122console headphone and speakers. This circuit is after the main AC97 1123or HDA mixer in the audio path, and under exclusive control of the 1124firmware. 1125 1126ThinkPads have three special hotkeys to interact with the console 1127audio control: volume up, volume down and mute. 1128 1129It is worth noting that the normal way the mute function works (on 1130ThinkPads that do not have a "mute LED") is: 1131 11321. Press mute to mute. It will *always* mute, you can press it as 1133 many times as you want, and the sound will remain mute. 1134 11352. Press either volume key to unmute the ThinkPad (it will _not_ 1136 change the volume, it will just unmute). 1137 1138This is a very superior design when compared to the cheap software-only 1139mute-toggle solution found on normal consumer laptops: you can be 1140absolutely sure the ThinkPad will not make noise if you press the mute 1141button, no matter the previous state. 1142 1143The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain 1144amplifiers driving the speakers and headphone output, and the firmware 1145also handles volume control for the headphone and speakers on these 1146ThinkPads without any help from the operating system (this volume 1147control stage exists after the main AC97 or HDA mixer in the audio 1148path). 1149 1150The newer Lenovo models only have firmware mute control, and depend on 1151the main HDA mixer to do volume control (which is done by the operating 1152system). In this case, the volume keys are filtered out for unmute 1153key press (there are some firmware bugs in this area) and delivered as 1154normal key presses to the operating system (thinkpad-acpi is not 1155involved). 1156 1157 1158The ThinkPad-ACPI volume control 1159^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1160 1161The preferred way to interact with the Console Audio control is the 1162ALSA interface. 1163 1164The legacy procfs interface allows one to read the current state, 1165and if volume control is enabled, accepts the following commands:: 1166 1167 echo up >/proc/acpi/ibm/volume 1168 echo down >/proc/acpi/ibm/volume 1169 echo mute >/proc/acpi/ibm/volume 1170 echo unmute >/proc/acpi/ibm/volume 1171 echo 'level <level>' >/proc/acpi/ibm/volume 1172 1173The <level> number range is 0 to 14 although not all of them may be 1174distinct. To unmute the volume after the mute command, use either the 1175up or down command (the level command will not unmute the volume), or 1176the unmute command. 1177 1178You can use the volume_capabilities parameter to tell the driver 1179whether your thinkpad has volume control or mute-only control: 1180volume_capabilities=1 for mixers with mute and volume control, 1181volume_capabilities=2 for mixers with only mute control. 1182 1183If the driver misdetects the capabilities for your ThinkPad model, 1184please report this to ibm-acpi-devel@lists.sourceforge.net, so that we 1185can update the driver. 1186 1187There are two strategies for volume control. To select which one 1188should be used, use the volume_mode module parameter: volume_mode=1 1189selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing 1190(so that volume/mute changes are remembered across shutdown/reboot). 1191 1192The driver will operate in volume_mode=3 by default. If that does not 1193work well on your ThinkPad model, please report this to 1194ibm-acpi-devel@lists.sourceforge.net. 1195 1196The driver supports the standard ALSA module parameters. If the ALSA 1197mixer is disabled, the driver will disable all volume functionality. 1198 1199 1200Fan control and monitoring: fan speed, fan enable/disable 1201--------------------------------------------------------- 1202 1203procfs: /proc/acpi/ibm/fan 1204 1205sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input 1206 1207sysfs hwmon driver attributes: fan_watchdog 1208 1209NOTE NOTE NOTE: 1210 fan control operations are disabled by default for 1211 safety reasons. To enable them, the module parameter "fan_control=1" 1212 must be given to thinkpad-acpi. 1213 1214This feature attempts to show the current fan speed, control mode and 1215other fan data that might be available. The speed is read directly 1216from the hardware registers of the embedded controller. This is known 1217to work on later R, T, X and Z series ThinkPads but may show a bogus 1218value on other models. 1219 1220Some Lenovo ThinkPads support a secondary fan. This fan cannot be 1221controlled separately, it shares the main fan control. 1222 1223Fan levels 1224^^^^^^^^^^ 1225 1226Most ThinkPad fans work in "levels" at the firmware interface. Level 0 1227stops the fan. The higher the level, the higher the fan speed, although 1228adjacent levels often map to the same fan speed. 7 is the highest 1229level, where the fan reaches the maximum recommended speed. 1230 1231Level "auto" means the EC changes the fan level according to some 1232internal algorithm, usually based on readings from the thermal sensors. 1233 1234There is also a "full-speed" level, also known as "disengaged" level. 1235In this level, the EC disables the speed-locked closed-loop fan control, 1236and drives the fan as fast as it can go, which might exceed hardware 1237limits, so use this level with caution. 1238 1239The fan usually ramps up or down slowly from one speed to another, and 1240it is normal for the EC to take several seconds to react to fan 1241commands. The full-speed level may take up to two minutes to ramp up to 1242maximum speed, and in some ThinkPads, the tachometer readings go stale 1243while the EC is transitioning to the full-speed level. 1244 1245WARNING WARNING WARNING: do not leave the fan disabled unless you are 1246monitoring all of the temperature sensor readings and you are ready to 1247enable it if necessary to avoid overheating. 1248 1249An enabled fan in level "auto" may stop spinning if the EC decides the 1250ThinkPad is cool enough and doesn't need the extra airflow. This is 1251normal, and the EC will spin the fan up if the various thermal readings 1252rise too much. 1253 1254On the X40, this seems to depend on the CPU and HDD temperatures. 1255Specifically, the fan is turned on when either the CPU temperature 1256climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The 1257fan is turned off when the CPU temperature drops to 49 degrees and the 1258HDD temperature drops to 41 degrees. These thresholds cannot 1259currently be controlled. 1260 1261The ThinkPad's ACPI DSDT code will reprogram the fan on its own when 1262certain conditions are met. It will override any fan programming done 1263through thinkpad-acpi. 1264 1265The thinkpad-acpi kernel driver can be programmed to revert the fan 1266level to a safe setting if userspace does not issue one of the procfs 1267fan commands: "enable", "disable", "level" or "watchdog", or if there 1268are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is 1269set to 1, manual mode) within a configurable amount of time of up to 1270120 seconds. This functionality is called fan safety watchdog. 1271 1272Note that the watchdog timer stops after it enables the fan. It will be 1273rearmed again automatically (using the same interval) when one of the 1274above mentioned fan commands is received. The fan watchdog is, 1275therefore, not suitable to protect against fan mode changes made through 1276means other than the "enable", "disable", and "level" procfs fan 1277commands, or the hwmon fan control sysfs interface. 1278 1279Procfs notes 1280^^^^^^^^^^^^ 1281 1282The fan may be enabled or disabled with the following commands:: 1283 1284 echo enable >/proc/acpi/ibm/fan 1285 echo disable >/proc/acpi/ibm/fan 1286 1287Placing a fan on level 0 is the same as disabling it. Enabling a fan 1288will try to place it in a safe level if it is too slow or disabled. 1289 1290The fan level can be controlled with the command:: 1291 1292 echo 'level <level>' > /proc/acpi/ibm/fan 1293 1294Where <level> is an integer from 0 to 7, or one of the words "auto" or 1295"full-speed" (without the quotes). Not all ThinkPads support the "auto" 1296and "full-speed" levels. The driver accepts "disengaged" as an alias for 1297"full-speed", and reports it as "disengaged" for backwards 1298compatibility. 1299 1300On the X31 and X40 (and ONLY on those models), the fan speed can be 1301controlled to a certain degree. Once the fan is running, it can be 1302forced to run faster or slower with the following command:: 1303 1304 echo 'speed <speed>' > /proc/acpi/ibm/fan 1305 1306The sustainable range of fan speeds on the X40 appears to be from about 13073700 to about 7350. Values outside this range either do not have any 1308effect or the fan speed eventually settles somewhere in that range. The 1309fan cannot be stopped or started with this command. This functionality 1310is incomplete, and not available through the sysfs interface. 1311 1312To program the safety watchdog, use the "watchdog" command:: 1313 1314 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan 1315 1316If you want to disable the watchdog, use 0 as the interval. 1317 1318Sysfs notes 1319^^^^^^^^^^^ 1320 1321The sysfs interface follows the hwmon subsystem guidelines for the most 1322part, and the exception is the fan safety watchdog. 1323 1324Writes to any of the sysfs attributes may return the EINVAL error if 1325that operation is not supported in a given ThinkPad or if the parameter 1326is out-of-bounds, and EPERM if it is forbidden. They may also return 1327EINTR (interrupted system call), and EIO (I/O error while trying to talk 1328to the firmware). 1329 1330Features not yet implemented by the driver return ENOSYS. 1331 1332hwmon device attribute pwm1_enable: 1333 - 0: PWM offline (fan is set to full-speed mode) 1334 - 1: Manual PWM control (use pwm1 to set fan level) 1335 - 2: Hardware PWM control (EC "auto" mode) 1336 - 3: reserved (Software PWM control, not implemented yet) 1337 1338 Modes 0 and 2 are not supported by all ThinkPads, and the 1339 driver is not always able to detect this. If it does know a 1340 mode is unsupported, it will return -EINVAL. 1341 1342hwmon device attribute pwm1: 1343 Fan level, scaled from the firmware values of 0-7 to the hwmon 1344 scale of 0-255. 0 means fan stopped, 255 means highest normal 1345 speed (level 7). 1346 1347 This attribute only commands the fan if pmw1_enable is set to 1 1348 (manual PWM control). 1349 1350hwmon device attribute fan1_input: 1351 Fan tachometer reading, in RPM. May go stale on certain 1352 ThinkPads while the EC transitions the PWM to offline mode, 1353 which can take up to two minutes. May return rubbish on older 1354 ThinkPads. 1355 1356hwmon device attribute fan2_input: 1357 Fan tachometer reading, in RPM, for the secondary fan. 1358 Available only on some ThinkPads. If the secondary fan is 1359 not installed, will always read 0. 1360 1361hwmon driver attribute fan_watchdog: 1362 Fan safety watchdog timer interval, in seconds. Minimum is 1363 1 second, maximum is 120 seconds. 0 disables the watchdog. 1364 1365To stop the fan: set pwm1 to zero, and pwm1_enable to 1. 1366 1367To start the fan in a safe mode: set pwm1_enable to 2. If that fails 1368with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255 1369would be the safest choice, though). 1370 1371 1372WAN 1373--- 1374 1375procfs: /proc/acpi/ibm/wan 1376 1377sysfs device attribute: wwan_enable (deprecated) 1378 1379sysfs rfkill class: switch "tpacpi_wwan_sw" 1380 1381This feature shows the presence and current state of the built-in 1382Wireless WAN device. 1383 1384If the ThinkPad supports it, the WWAN state is stored in NVRAM, 1385so it is kept across reboots and power-off. 1386 1387It was tested on a Lenovo ThinkPad X60. It should probably work on other 1388ThinkPad models which come with this module installed. 1389 1390Procfs notes 1391^^^^^^^^^^^^ 1392 1393If the W-WAN card is installed, the following commands can be used:: 1394 1395 echo enable > /proc/acpi/ibm/wan 1396 echo disable > /proc/acpi/ibm/wan 1397 1398Sysfs notes 1399^^^^^^^^^^^ 1400 1401 If the W-WAN card is installed, it can be enabled / 1402 disabled through the "wwan_enable" thinkpad-acpi device 1403 attribute, and its current status can also be queried. 1404 1405 enable: 1406 - 0: disables WWAN card / WWAN card is disabled 1407 - 1: enables WWAN card / WWAN card is enabled. 1408 1409 Note: this interface has been superseded by the generic rfkill 1410 class. It has been deprecated, and it will be removed in year 1411 2010. 1412 1413 rfkill controller switch "tpacpi_wwan_sw": refer to 1414 Documentation/driver-api/rfkill.rst for details. 1415 1416 1417LCD Shadow control 1418------------------ 1419 1420procfs: /proc/acpi/ibm/lcdshadow 1421 1422Some newer T480s and T490s ThinkPads provide a feature called 1423PrivacyGuard. By turning this feature on, the usable vertical and 1424horizontal viewing angles of the LCD can be limited (as if some privacy 1425screen was applied manually in front of the display). 1426 1427procfs notes 1428^^^^^^^^^^^^ 1429 1430The available commands are:: 1431 1432 echo '0' >/proc/acpi/ibm/lcdshadow 1433 echo '1' >/proc/acpi/ibm/lcdshadow 1434 1435The first command ensures the best viewing angle and the latter one turns 1436on the feature, restricting the viewing angles. 1437 1438 1439DYTC Lapmode sensor 1440------------------- 1441 1442sysfs: dytc_lapmode 1443 1444Newer thinkpads and mobile workstations have the ability to determine if 1445the device is in deskmode or lapmode. This feature is used by user space 1446to decide if WWAN transmission can be increased to maximum power and is 1447also useful for understanding the different thermal modes available as 1448they differ between desk and lap mode. 1449 1450The property is read-only. If the platform doesn't have support the sysfs 1451class is not created. 1452 1453EXPERIMENTAL: UWB 1454----------------- 1455 1456This feature is considered EXPERIMENTAL because it has not been extensively 1457tested and validated in various ThinkPad models yet. The feature may not 1458work as expected. USE WITH CAUTION! To use this feature, you need to supply 1459the experimental=1 parameter when loading the module. 1460 1461sysfs rfkill class: switch "tpacpi_uwb_sw" 1462 1463This feature exports an rfkill controller for the UWB device, if one is 1464present and enabled in the BIOS. 1465 1466Sysfs notes 1467^^^^^^^^^^^ 1468 1469 rfkill controller switch "tpacpi_uwb_sw": refer to 1470 Documentation/driver-api/rfkill.rst for details. 1471 1472 1473Setting keyboard language 1474------------------------- 1475 1476sysfs: keyboard_lang 1477 1478This feature is used to set keyboard language to ECFW using ASL interface. 1479Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(', 1480")" numeric keys, which are not displaying correctly, when keyboard language 1481is other than "english". This is because the default keyboard language in ECFW 1482is set as "english". Hence using this sysfs, user can set the correct keyboard 1483language to ECFW and then these key's will work correctly. 1484 1485Example of command to set keyboard language is mentioned below:: 1486 1487 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang 1488 1489Text corresponding to keyboard layout to be set in sysfs are: be(Belgian), 1490cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian), 1491fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan), 1492nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden), 1493tr(Turkey) 1494 1495WWAN Antenna type 1496----------------- 1497 1498sysfs: wwan_antenna_type 1499 1500On some newer Thinkpads we need to set SAR value based on the antenna 1501type. This interface will be used by userspace to get the antenna type 1502and set the corresponding SAR value, as is required for FCC certification. 1503 1504The available commands are:: 1505 1506 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type 1507 1508Currently 2 antenna types are supported as mentioned below: 1509- type a 1510- type b 1511 1512The property is read-only. If the platform doesn't have support the sysfs 1513class is not created. 1514 1515Auxmac 1516------ 1517 1518sysfs: auxmac 1519 1520Some newer Thinkpads have a feature called MAC Address Pass-through. This 1521feature is implemented by the system firmware to provide a system unique MAC, 1522that can override a dock or USB ethernet dongle MAC, when connected to a 1523network. This property enables user-space to easily determine the MAC address 1524if the feature is enabled. 1525 1526The values of this auxiliary MAC are: 1527 1528 cat /sys/devices/platform/thinkpad_acpi/auxmac 1529 1530If the feature is disabled, the value will be 'disabled'. 1531 1532This property is read-only. 1533 1534Adaptive keyboard 1535----------------- 1536 1537sysfs device attribute: adaptive_kbd_mode 1538 1539This sysfs attribute controls the keyboard "face" that will be shown on the 1540Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read 1541and set. 1542 1543- 0 = Home mode 1544- 1 = Web-browser mode 1545- 2 = Web-conference mode 1546- 3 = Function mode 1547- 4 = Layflat mode 1548 1549For more details about which buttons will appear depending on the mode, please 1550review the laptop's user guide: 1551https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf 1552 1553Battery charge control 1554---------------------- 1555 1556sysfs attributes: 1557/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold 1558 1559These two attributes are created for those batteries that are supported by the 1560driver. They enable the user to control the battery charge thresholds of the 1561given battery. Both values may be read and set. `charge_control_start_threshold` 1562accepts an integer between 0 and 99 (inclusive); this value represents a battery 1563percentage level, below which charging will begin. `charge_control_end_threshold` 1564accepts an integer between 1 and 100 (inclusive); this value represents a battery 1565percentage level, above which charging will stop. 1566 1567The exact semantics of the attributes may be found in 1568Documentation/ABI/testing/sysfs-class-power. 1569 1570Multiple Commands, Module Parameters 1571------------------------------------ 1572 1573Multiple commands can be written to the proc files in one shot by 1574separating them with commas, for example:: 1575 1576 echo enable,0xffff > /proc/acpi/ibm/hotkey 1577 echo lcd_disable,crt_enable > /proc/acpi/ibm/video 1578 1579Commands can also be specified when loading the thinkpad-acpi module, 1580for example:: 1581 1582 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable 1583 1584 1585Enabling debugging output 1586------------------------- 1587 1588The module takes a debug parameter which can be used to selectively 1589enable various classes of debugging output, for example:: 1590 1591 modprobe thinkpad_acpi debug=0xffff 1592 1593will enable all debugging output classes. It takes a bitmask, so 1594to enable more than one output class, just add their values. 1595 1596 ============= ====================================== 1597 Debug bitmask Description 1598 ============= ====================================== 1599 0x8000 Disclose PID of userspace programs 1600 accessing some functions of the driver 1601 0x0001 Initialization and probing 1602 0x0002 Removal 1603 0x0004 RF Transmitter control (RFKILL) 1604 (bluetooth, WWAN, UWB...) 1605 0x0008 HKEY event interface, hotkeys 1606 0x0010 Fan control 1607 0x0020 Backlight brightness 1608 0x0040 Audio mixer/volume control 1609 ============= ====================================== 1610 1611There is also a kernel build option to enable more debugging 1612information, which may be necessary to debug driver problems. 1613 1614The level of debugging information output by the driver can be changed 1615at runtime through sysfs, using the driver attribute debug_level. The 1616attribute takes the same bitmask as the debug module parameter above. 1617 1618 1619Force loading of module 1620----------------------- 1621 1622If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify 1623the module parameter force_load=1. Regardless of whether this works or 1624not, please contact ibm-acpi-devel@lists.sourceforge.net with a report. 1625 1626 1627Sysfs interface changelog 1628^^^^^^^^^^^^^^^^^^^^^^^^^ 1629 1630========= =============================================================== 16310x000100: Initial sysfs support, as a single platform driver and 1632 device. 16330x000200: Hot key support for 32 hot keys, and radio slider switch 1634 support. 16350x010000: Hot keys are now handled by default over the input 1636 layer, the radio switch generates input event EV_RADIO, 1637 and the driver enables hot key handling by default in 1638 the firmware. 1639 16400x020000: ABI fix: added a separate hwmon platform device and 1641 driver, which must be located by name (thinkpad) 1642 and the hwmon class for libsensors4 (lm-sensors 3) 1643 compatibility. Moved all hwmon attributes to this 1644 new platform device. 1645 16460x020100: Marker for thinkpad-acpi with hot key NVRAM polling 1647 support. If you must, use it to know you should not 1648 start a userspace NVRAM poller (allows to detect when 1649 NVRAM is compiled out by the user because it is 1650 unneeded/undesired in the first place). 16510x020101: Marker for thinkpad-acpi with hot key NVRAM polling 1652 and proper hotkey_mask semantics (version 8 of the 1653 NVRAM polling patch). Some development snapshots of 1654 0.18 had an earlier version that did strange things 1655 to hotkey_mask. 1656 16570x020200: Add poll()/select() support to the following attributes: 1658 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason 1659 16600x020300: hotkey enable/disable support removed, attributes 1661 hotkey_bios_enabled and hotkey_enable deprecated and 1662 marked for removal. 1663 16640x020400: Marker for 16 LEDs support. Also, LEDs that are known 1665 to not exist in a given model are not registered with 1666 the LED sysfs class anymore. 1667 16680x020500: Updated hotkey driver, hotkey_mask is always available 1669 and it is always able to disable hot keys. Very old 1670 thinkpads are properly supported. hotkey_bios_mask 1671 is deprecated and marked for removal. 1672 16730x020600: Marker for backlight change event support. 1674 16750x020700: Support for mute-only mixers. 1676 Volume control in read-only mode by default. 1677 Marker for ALSA mixer support. 1678 16790x030000: Thermal and fan sysfs attributes were moved to the hwmon 1680 device instead of being attached to the backing platform 1681 device. 1682========= =============================================================== 1683