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 57A compatibility table by model and feature is maintained on the web 58site, http://ibm-acpi.sf.net/. I appreciate any success or failure 59reports, especially if they add to or correct the compatibility table. 60Please include the following information in your report: 61 62 - ThinkPad model name 63 - a copy of your ACPI tables, using the "acpidump" utility 64 - a copy of the output of dmidecode, with serial numbers 65 and UUIDs masked off 66 - which driver features work and which don't 67 - the observed behavior of non-working features 68 69Any other comments or patches are also more than welcome. 70 71 72Installation 73------------ 74 75If you are compiling this driver as included in the Linux kernel 76sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. 77It is located on the menu path: "Device Drivers" -> "X86 Platform 78Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". 79 80 81Features 82-------- 83 84The driver exports two different interfaces to userspace, which can be 85used to access the features it provides. One is a legacy procfs-based 86interface, which will be removed at some time in the future. The other 87is a new sysfs-based interface which is not complete yet. 88 89The procfs interface creates the /proc/acpi/ibm directory. There is a 90file under that directory for each feature it supports. The procfs 91interface is mostly frozen, and will change very little if at all: it 92will not be extended to add any new functionality in the driver, instead 93all new functionality will be implemented on the sysfs interface. 94 95The sysfs interface tries to blend in the generic Linux sysfs subsystems 96and classes as much as possible. Since some of these subsystems are not 97yet ready or stabilized, it is expected that this interface will change, 98and any and all userspace programs must deal with it. 99 100 101Notes about the sysfs interface 102^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 103 104Unlike what was done with the procfs interface, correctness when talking 105to the sysfs interfaces will be enforced, as will correctness in the 106thinkpad-acpi's implementation of sysfs interfaces. 107 108Also, any bugs in the thinkpad-acpi sysfs driver code or in the 109thinkpad-acpi's implementation of the sysfs interfaces will be fixed for 110maximum correctness, even if that means changing an interface in 111non-compatible ways. As these interfaces mature both in the kernel and 112in thinkpad-acpi, such changes should become quite rare. 113 114Applications interfacing to the thinkpad-acpi sysfs interfaces must 115follow all sysfs guidelines and correctly process all errors (the sysfs 116interface makes extensive use of errors). File descriptors and open / 117close operations to the sysfs inodes must also be properly implemented. 118 119The version of thinkpad-acpi's sysfs interface is exported by the driver 120as a driver attribute (see below). 121 122Sysfs driver attributes are on the driver's sysfs attribute space, 123for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and 124/sys/bus/platform/drivers/thinkpad_hwmon/ 125 126Sysfs device attributes are on the thinkpad_acpi device sysfs attribute 127space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. 128 129Sysfs device attributes for the sensors and fan are on the 130thinkpad_hwmon device's sysfs attribute space, but you should locate it 131looking for a hwmon device with the name attribute of "thinkpad", or 132better yet, through libsensors. For 4.14+ sysfs attributes were moved to the 133hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or 134/sys/class/hwmon/hwmon?). 135 136Driver version 137-------------- 138 139procfs: /proc/acpi/ibm/driver 140 141sysfs driver attribute: version 142 143The driver name and version. No commands can be written to this file. 144 145 146Sysfs interface version 147----------------------- 148 149sysfs driver attribute: interface_version 150 151Version of the thinkpad-acpi sysfs interface, as an unsigned long 152(output in hex format: 0xAAAABBCC), where: 153 154 AAAA 155 - major revision 156 BB 157 - minor revision 158 CC 159 - bugfix revision 160 161The sysfs interface version changelog for the driver can be found at the 162end of this document. Changes to the sysfs interface done by the kernel 163subsystems are not documented here, nor are they tracked by this 164attribute. 165 166Changes to the thinkpad-acpi sysfs interface are only considered 167non-experimental when they are submitted to Linux mainline, at which 168point the changes in this interface are documented and interface_version 169may be updated. If you are using any thinkpad-acpi features not yet 170sent to mainline for merging, you do so on your own risk: these features 171may disappear, or be implemented in a different and incompatible way by 172the time they are merged in Linux mainline. 173 174Changes that are backwards-compatible by nature (e.g. the addition of 175attributes that do not change the way the other attributes work) do not 176always warrant an update of interface_version. Therefore, one must 177expect that an attribute might not be there, and deal with it properly 178(an attribute not being there *is* a valid way to make it clear that a 179feature is not available in sysfs). 180 181 182Hot keys 183-------- 184 185procfs: /proc/acpi/ibm/hotkey 186 187sysfs device attribute: hotkey_* 188 189In a ThinkPad, the ACPI HKEY handler is responsible for communicating 190some important events and also keyboard hot key presses to the operating 191system. Enabling the hotkey functionality of thinkpad-acpi signals the 192firmware that such a driver is present, and modifies how the ThinkPad 193firmware will behave in many situations. 194 195The driver enables the HKEY ("hot key") event reporting automatically 196when loaded, and disables it when it is removed. 197 198The driver will report HKEY events in the following format:: 199 200 ibm/hotkey HKEY 00000080 0000xxxx 201 202Some of these events refer to hot key presses, but not all of them. 203 204The driver will generate events over the input layer for hot keys and 205radio switches, and over the ACPI netlink layer for other events. The 206input layer support accepts the standard IOCTLs to remap the keycodes 207assigned to each hot key. 208 209The hot key bit mask allows some control over which hot keys generate 210events. If a key is "masked" (bit set to 0 in the mask), the firmware 211will handle it. If it is "unmasked", it signals the firmware that 212thinkpad-acpi would prefer to handle it, if the firmware would be so 213kind to allow it (and it often doesn't!). 214 215Not all bits in the mask can be modified. Not all bits that can be 216modified do anything. Not all hot keys can be individually controlled 217by the mask. Some models do not support the mask at all. The behaviour 218of the mask is, therefore, highly dependent on the ThinkPad model. 219 220The driver will filter out any unmasked hotkeys, so even if the firmware 221doesn't allow disabling an specific hotkey, the driver will not report 222events for unmasked hotkeys. 223 224Note that unmasking some keys prevents their default behavior. For 225example, if Fn+F5 is unmasked, that key will no longer enable/disable 226Bluetooth by itself in firmware. 227 228Note also that not all Fn key combinations are supported through ACPI 229depending on the ThinkPad model and firmware version. On those 230ThinkPads, it is still possible to support some extra hotkeys by 231polling the "CMOS NVRAM" at least 10 times per second. The driver 232attempts to enables this functionality automatically when required. 233 234procfs notes 235^^^^^^^^^^^^ 236 237The following commands can be written to the /proc/acpi/ibm/hotkey file:: 238 239 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys 240 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys 241 ... any other 8-hex-digit mask ... 242 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask 243 244The following commands have been deprecated and will cause the kernel 245to log a warning:: 246 247 echo enable > /proc/acpi/ibm/hotkey -- does nothing 248 echo disable > /proc/acpi/ibm/hotkey -- returns an error 249 250The procfs interface does not support NVRAM polling control. So as to 251maintain maximum bug-to-bug compatibility, it does not report any masks, 252nor does it allow one to manipulate the hot key mask when the firmware 253does not support masks at all, even if NVRAM polling is in use. 254 255sysfs notes 256^^^^^^^^^^^ 257 258 hotkey_bios_enabled: 259 DEPRECATED, WILL BE REMOVED SOON. 260 261 Returns 0. 262 263 hotkey_bios_mask: 264 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE. 265 266 Returns the hot keys mask when thinkpad-acpi was loaded. 267 Upon module unload, the hot keys mask will be restored 268 to this value. This is always 0x80c, because those are 269 the hotkeys that were supported by ancient firmware 270 without mask support. 271 272 hotkey_enable: 273 DEPRECATED, WILL BE REMOVED SOON. 274 275 0: returns -EPERM 276 1: does nothing 277 278 hotkey_mask: 279 bit mask to enable reporting (and depending on 280 the firmware, ACPI event generation) for each hot key 281 (see above). Returns the current status of the hot keys 282 mask, and allows one to modify it. 283 284 hotkey_all_mask: 285 bit mask that should enable event reporting for all 286 supported hot keys, when echoed to hotkey_mask above. 287 Unless you know which events need to be handled 288 passively (because the firmware *will* handle them 289 anyway), do *not* use hotkey_all_mask. Use 290 hotkey_recommended_mask, instead. You have been warned. 291 292 hotkey_recommended_mask: 293 bit mask that should enable event reporting for all 294 supported hot keys, except those which are always 295 handled by the firmware anyway. Echo it to 296 hotkey_mask above, to use. This is the default mask 297 used by the driver. 298 299 hotkey_source_mask: 300 bit mask that selects which hot keys will the driver 301 poll the NVRAM for. This is auto-detected by the driver 302 based on the capabilities reported by the ACPI firmware, 303 but it can be overridden at runtime. 304 305 Hot keys whose bits are set in hotkey_source_mask are 306 polled for in NVRAM, and reported as hotkey events if 307 enabled in hotkey_mask. Only a few hot keys are 308 available through CMOS NVRAM polling. 309 310 Warning: when in NVRAM mode, the volume up/down/mute 311 keys are synthesized according to changes in the mixer, 312 which uses a single volume up or volume down hotkey 313 press to unmute, as per the ThinkPad volume mixer user 314 interface. When in ACPI event mode, volume up/down/mute 315 events are reported by the firmware and can behave 316 differently (and that behaviour changes with firmware 317 version -- not just with firmware models -- as well as 318 OSI(Linux) state). 319 320 hotkey_poll_freq: 321 frequency in Hz for hot key polling. It must be between 322 0 and 25 Hz. Polling is only carried out when strictly 323 needed. 324 325 Setting hotkey_poll_freq to zero disables polling, and 326 will cause hot key presses that require NVRAM polling 327 to never be reported. 328 329 Setting hotkey_poll_freq too low may cause repeated 330 pressings of the same hot key to be misreported as a 331 single key press, or to not even be detected at all. 332 The recommended polling frequency is 10Hz. 333 334 hotkey_radio_sw: 335 If the ThinkPad has a hardware radio switch, this 336 attribute will read 0 if the switch is in the "radios 337 disabled" position, and 1 if the switch is in the 338 "radios enabled" position. 339 340 This attribute has poll()/select() support. 341 342 hotkey_tablet_mode: 343 If the ThinkPad has tablet capabilities, this attribute 344 will read 0 if the ThinkPad is in normal mode, and 345 1 if the ThinkPad is in tablet mode. 346 347 This attribute has poll()/select() support. 348 349 wakeup_reason: 350 Set to 1 if the system is waking up because the user 351 requested a bay ejection. Set to 2 if the system is 352 waking up because the user requested the system to 353 undock. Set to zero for normal wake-ups or wake-ups 354 due to unknown reasons. 355 356 This attribute has poll()/select() support. 357 358 wakeup_hotunplug_complete: 359 Set to 1 if the system was waken up because of an 360 undock or bay ejection request, and that request 361 was successfully completed. At this point, it might 362 be useful to send the system back to sleep, at the 363 user's choice. Refer to HKEY events 0x4003 and 364 0x3003, below. 365 366 This attribute has poll()/select() support. 367 368input layer notes 369^^^^^^^^^^^^^^^^^ 370 371A Hot key is mapped to a single input layer EV_KEY event, possibly 372followed by an EV_MSC MSC_SCAN event that shall contain that key's scan 373code. An EV_SYN event will always be generated to mark the end of the 374event block. 375 376Do not use the EV_MSC MSC_SCAN events to process keys. They are to be 377used as a helper to remap keys, only. They are particularly useful when 378remapping KEY_UNKNOWN keys. 379 380The events are available in an input device, with the following id: 381 382 ============== ============================== 383 Bus BUS_HOST 384 vendor 0x1014 (PCI_VENDOR_ID_IBM) or 385 0x17aa (PCI_VENDOR_ID_LENOVO) 386 product 0x5054 ("TP") 387 version 0x4101 388 ============== ============================== 389 390The version will have its LSB incremented if the keymap changes in a 391backwards-compatible way. The MSB shall always be 0x41 for this input 392device. If the MSB is not 0x41, do not use the device as described in 393this section, as it is either something else (e.g. another input device 394exported by a thinkpad driver, such as HDAPS) or its functionality has 395been changed in a non-backwards compatible way. 396 397Adding other event types for other functionalities shall be considered a 398backwards-compatible change for this input device. 399 400Thinkpad-acpi Hot Key event map (version 0x4101): 401 402======= ======= ============== ============================================== 403ACPI Scan 404event code Key Notes 405======= ======= ============== ============================================== 4060x1001 0x00 FN+F1 - 407 4080x1002 0x01 FN+F2 IBM: battery (rare) 409 Lenovo: Screen lock 410 4110x1003 0x02 FN+F3 Many IBM models always report 412 this hot key, even with hot keys 413 disabled or with Fn+F3 masked 414 off 415 IBM: screen lock, often turns 416 off the ThinkLight as side-effect 417 Lenovo: battery 418 4190x1004 0x03 FN+F4 Sleep button (ACPI sleep button 420 semantics, i.e. sleep-to-RAM). 421 It always generates some kind 422 of event, either the hot key 423 event or an ACPI sleep button 424 event. The firmware may 425 refuse to generate further FN+F4 426 key presses until a S3 or S4 ACPI 427 sleep cycle is performed or some 428 time passes. 429 4300x1005 0x04 FN+F5 Radio. Enables/disables 431 the internal Bluetooth hardware 432 and W-WAN card if left in control 433 of the firmware. Does not affect 434 the WLAN card. 435 Should be used to turn on/off all 436 radios (Bluetooth+W-WAN+WLAN), 437 really. 438 4390x1006 0x05 FN+F6 - 440 4410x1007 0x06 FN+F7 Video output cycle. 442 Do you feel lucky today? 443 4440x1008 0x07 FN+F8 IBM: toggle screen expand 445 Lenovo: configure UltraNav, 446 or toggle screen expand 447 4480x1009 0x08 FN+F9 - 449 450... ... ... ... 451 4520x100B 0x0A FN+F11 - 453 4540x100C 0x0B FN+F12 Sleep to disk. You are always 455 supposed to handle it yourself, 456 either through the ACPI event, 457 or through a hotkey event. 458 The firmware may refuse to 459 generate further FN+F12 key 460 press events until a S3 or S4 461 ACPI sleep cycle is performed, 462 or some time passes. 463 4640x100D 0x0C FN+BACKSPACE - 4650x100E 0x0D FN+INSERT - 4660x100F 0x0E FN+DELETE - 467 4680x1010 0x0F FN+HOME Brightness up. This key is 469 always handled by the firmware 470 in IBM ThinkPads, even when 471 unmasked. Just leave it alone. 472 For Lenovo ThinkPads with a new 473 BIOS, it has to be handled either 474 by the ACPI OSI, or by userspace. 475 The driver does the right thing, 476 never mess with this. 4770x1011 0x10 FN+END Brightness down. See brightness 478 up for details. 479 4800x1012 0x11 FN+PGUP ThinkLight toggle. This key is 481 always handled by the firmware, 482 even when unmasked. 483 4840x1013 0x12 FN+PGDOWN - 485 4860x1014 0x13 FN+SPACE Zoom key 487 4880x1015 0x14 VOLUME UP Internal mixer volume up. This 489 key is always handled by the 490 firmware, even when unmasked. 491 NOTE: Lenovo seems to be changing 492 this. 4930x1016 0x15 VOLUME DOWN Internal mixer volume up. This 494 key is always handled by the 495 firmware, even when unmasked. 496 NOTE: Lenovo seems to be changing 497 this. 4980x1017 0x16 MUTE Mute internal mixer. This 499 key is always handled by the 500 firmware, even when unmasked. 501 5020x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key 503 5040x1019 0x18 unknown 505 506... ... ... 507 5080x1020 0x1F unknown 509======= ======= ============== ============================================== 510 511The ThinkPad firmware does not allow one to differentiate when most hot 512keys are pressed or released (either that, or we don't know how to, yet). 513For these keys, the driver generates a set of events for a key press and 514immediately issues the same set of events for a key release. It is 515unknown by the driver if the ThinkPad firmware triggered these events on 516hot key press or release, but the firmware will do it for either one, not 517both. 518 519If a key is mapped to KEY_RESERVED, it generates no input events at all. 520If a key is mapped to KEY_UNKNOWN, it generates an input event that 521includes an scan code. If a key is mapped to anything else, it will 522generate input device EV_KEY events. 523 524In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW 525events for switches: 526 527============== ============================================== 528SW_RFKILL_ALL T60 and later hardware rfkill rocker switch 529SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A 530============== ============================================== 531 532Non hotkey ACPI HKEY event map 533------------------------------ 534 535Events that are never propagated by the driver: 536 537====== ================================================== 5380x2304 System is waking up from suspend to undock 5390x2305 System is waking up from suspend to eject bay 5400x2404 System is waking up from hibernation to undock 5410x2405 System is waking up from hibernation to eject bay 5420x5001 Lid closed 5430x5002 Lid opened 5440x5009 Tablet swivel: switched to tablet mode 5450x500A Tablet swivel: switched to normal mode 5460x5010 Brightness level changed/control event 5470x6000 KEYBOARD: Numlock key pressed 5480x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) 5490x7000 Radio Switch may have changed state 550====== ================================================== 551 552 553Events that are propagated by the driver to userspace: 554 555====== ===================================================== 5560x2313 ALARM: System is waking up from suspend because 557 the battery is nearly empty 5580x2413 ALARM: System is waking up from hibernation because 559 the battery is nearly empty 5600x3003 Bay ejection (see 0x2x05) complete, can sleep again 5610x3006 Bay hotplug request (hint to power up SATA link when 562 the optical drive tray is ejected) 5630x4003 Undocked (see 0x2x04), can sleep again 5640x4010 Docked into hotplug port replicator (non-ACPI dock) 5650x4011 Undocked from hotplug port replicator (non-ACPI dock) 5660x500B Tablet pen inserted into its storage bay 5670x500C Tablet pen removed from its storage bay 5680x6011 ALARM: battery is too hot 5690x6012 ALARM: battery is extremely hot 5700x6021 ALARM: a sensor is too hot 5710x6022 ALARM: a sensor is extremely hot 5720x6030 System thermal table changed 5730x6032 Thermal Control command set completion (DYTC, Windows) 5740x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) 5750x60C0 X1 Yoga 2016, Tablet mode status changed 5760x60F0 Thermal Transformation changed (GMTS, Windows) 577====== ===================================================== 578 579Battery nearly empty alarms are a last resort attempt to get the 580operating system to hibernate or shutdown cleanly (0x2313), or shutdown 581cleanly (0x2413) before power is lost. They must be acted upon, as the 582wake up caused by the firmware will have negated most safety nets... 583 584When any of the "too hot" alarms happen, according to Lenovo the user 585should suspend or hibernate the laptop (and in the case of battery 586alarms, unplug the AC adapter) to let it cool down. These alarms do 587signal that something is wrong, they should never happen on normal 588operating conditions. 589 590The "extremely hot" alarms are emergencies. According to Lenovo, the 591operating system is to force either an immediate suspend or hibernate 592cycle, or a system shutdown. Obviously, something is very wrong if this 593happens. 594 595 596Brightness hotkey notes 597^^^^^^^^^^^^^^^^^^^^^^^ 598 599Don't mess with the brightness hotkeys in a Thinkpad. If you want 600notifications for OSD, use the sysfs backlight class event support. 601 602The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events 603automatically for the cases were userspace has to do something to 604implement brightness changes. When you override these events, you will 605either fail to handle properly the ThinkPads that require explicit 606action to change backlight brightness, or the ThinkPads that require 607that no action be taken to work properly. 608 609 610Bluetooth 611--------- 612 613procfs: /proc/acpi/ibm/bluetooth 614 615sysfs device attribute: bluetooth_enable (deprecated) 616 617sysfs rfkill class: switch "tpacpi_bluetooth_sw" 618 619This feature shows the presence and current state of a ThinkPad 620Bluetooth device in the internal ThinkPad CDC slot. 621 622If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, 623so it is kept across reboots and power-off. 624 625Procfs notes 626^^^^^^^^^^^^ 627 628If Bluetooth is installed, the following commands can be used:: 629 630 echo enable > /proc/acpi/ibm/bluetooth 631 echo disable > /proc/acpi/ibm/bluetooth 632 633Sysfs notes 634^^^^^^^^^^^ 635 636 If the Bluetooth CDC card is installed, it can be enabled / 637 disabled through the "bluetooth_enable" thinkpad-acpi device 638 attribute, and its current status can also be queried. 639 640 enable: 641 642 - 0: disables Bluetooth / Bluetooth is disabled 643 - 1: enables Bluetooth / Bluetooth is enabled. 644 645 Note: this interface has been superseded by the generic rfkill 646 class. It has been deprecated, and it will be removed in year 647 2010. 648 649 rfkill controller switch "tpacpi_bluetooth_sw": refer to 650 Documentation/driver-api/rfkill.rst for details. 651 652 653Video output control -- /proc/acpi/ibm/video 654-------------------------------------------- 655 656This feature allows control over the devices used for video output - 657LCD, CRT or DVI (if available). The following commands are available:: 658 659 echo lcd_enable > /proc/acpi/ibm/video 660 echo lcd_disable > /proc/acpi/ibm/video 661 echo crt_enable > /proc/acpi/ibm/video 662 echo crt_disable > /proc/acpi/ibm/video 663 echo dvi_enable > /proc/acpi/ibm/video 664 echo dvi_disable > /proc/acpi/ibm/video 665 echo auto_enable > /proc/acpi/ibm/video 666 echo auto_disable > /proc/acpi/ibm/video 667 echo expand_toggle > /proc/acpi/ibm/video 668 echo video_switch > /proc/acpi/ibm/video 669 670NOTE: 671 Access to this feature is restricted to processes owning the 672 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly 673 enough with some versions of X.org to crash it. 674 675Each video output device can be enabled or disabled individually. 676Reading /proc/acpi/ibm/video shows the status of each device. 677 678Automatic video switching can be enabled or disabled. When automatic 679video switching is enabled, certain events (e.g. opening the lid, 680docking or undocking) cause the video output device to change 681automatically. While this can be useful, it also causes flickering 682and, on the X40, video corruption. By disabling automatic switching, 683the flickering or video corruption can be avoided. 684 685The video_switch command cycles through the available video outputs 686(it simulates the behavior of Fn-F7). 687 688Video expansion can be toggled through this feature. This controls 689whether the display is expanded to fill the entire LCD screen when a 690mode with less than full resolution is used. Note that the current 691video expansion status cannot be determined through this feature. 692 693Note that on many models (particularly those using Radeon graphics 694chips) the X driver configures the video card in a way which prevents 695Fn-F7 from working. This also disables the video output switching 696features of this driver, as it uses the same ACPI methods as 697Fn-F7. Video switching on the console should still work. 698 699UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 700 701 702ThinkLight control 703------------------ 704 705procfs: /proc/acpi/ibm/light 706 707sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED 708 709procfs notes 710^^^^^^^^^^^^ 711 712The ThinkLight status can be read and set through the procfs interface. A 713few models which do not make the status available will show the ThinkLight 714status as "unknown". The available commands are:: 715 716 echo on > /proc/acpi/ibm/light 717 echo off > /proc/acpi/ibm/light 718 719sysfs notes 720^^^^^^^^^^^ 721 722The ThinkLight sysfs interface is documented by the LED class 723documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name 724is "tpacpi::thinklight". 725 726Due to limitations in the sysfs LED class, if the status of the ThinkLight 727cannot be read or if it is unknown, thinkpad-acpi will report it as "off". 728It is impossible to know if the status returned through sysfs is valid. 729 730 731CMOS/UCMS control 732----------------- 733 734procfs: /proc/acpi/ibm/cmos 735 736sysfs device attribute: cmos_command 737 738This feature is mostly used internally by the ACPI firmware to keep the legacy 739CMOS NVRAM bits in sync with the current machine state, and to record this 740state so that the ThinkPad will retain such settings across reboots. 741 742Some of these commands actually perform actions in some ThinkPad models, but 743this is expected to disappear more and more in newer models. As an example, in 744a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for 745real, but commands 0 to 2 don't control the mixer anymore (they have been 746phased out) and just update the NVRAM. 747 748The range of valid cmos command numbers is 0 to 21, but not all have an 749effect and the behavior varies from model to model. Here is the behavior 750on the X40 (tpb is the ThinkPad Buttons utility): 751 752 - 0 - Related to "Volume down" key press 753 - 1 - Related to "Volume up" key press 754 - 2 - Related to "Mute on" key press 755 - 3 - Related to "Access IBM" key press 756 - 4 - Related to "LCD brightness up" key press 757 - 5 - Related to "LCD brightness down" key press 758 - 11 - Related to "toggle screen expansion" key press/function 759 - 12 - Related to "ThinkLight on" 760 - 13 - Related to "ThinkLight off" 761 - 14 - Related to "ThinkLight" key press (toggle ThinkLight) 762 763The cmos command interface is prone to firmware split-brain problems, as 764in newer ThinkPads it is just a compatibility layer. Do not use it, it is 765exported just as a debug tool. 766 767 768LED control 769----------- 770 771procfs: /proc/acpi/ibm/led 772sysfs attributes: as per LED class, see below for names 773 774Some of the LED indicators can be controlled through this feature. On 775some older ThinkPad models, it is possible to query the status of the 776LED indicators as well. Newer ThinkPads cannot query the real status 777of the LED indicators. 778 779Because misuse of the LEDs could induce an unaware user to perform 780dangerous actions (like undocking or ejecting a bay device while the 781buses are still active), or mask an important alarm (such as a nearly 782empty battery, or a broken battery), access to most LEDs is 783restricted. 784 785Unrestricted access to all LEDs requires that thinkpad-acpi be 786compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. 787Distributions must never enable this option. Individual users that 788are aware of the consequences are welcome to enabling it. 789 790Audio mute and microphone mute LEDs are supported, but currently not 791visible to userspace. They are used by the snd-hda-intel audio driver. 792 793procfs notes 794^^^^^^^^^^^^ 795 796The available commands are:: 797 798 echo '<LED number> on' >/proc/acpi/ibm/led 799 echo '<LED number> off' >/proc/acpi/ibm/led 800 echo '<LED number> blink' >/proc/acpi/ibm/led 801 802The <LED number> range is 0 to 15. The set of LEDs that can be 803controlled varies from model to model. Here is the common ThinkPad 804mapping: 805 806 - 0 - power 807 - 1 - battery (orange) 808 - 2 - battery (green) 809 - 3 - UltraBase/dock 810 - 4 - UltraBay 811 - 5 - UltraBase battery slot 812 - 6 - (unknown) 813 - 7 - standby 814 - 8 - dock status 1 815 - 9 - dock status 2 816 - 10, 11 - (unknown) 817 - 12 - thinkvantage 818 - 13, 14, 15 - (unknown) 819 820All of the above can be turned on and off and can be made to blink. 821 822sysfs notes 823^^^^^^^^^^^ 824 825The ThinkPad LED sysfs interface is described in detail by the LED class 826documentation, in Documentation/leds/leds-class.rst. 827 828The LEDs are named (in LED ID order, from 0 to 12): 829"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", 830"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", 831"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", 832"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", 833"tpacpi::thinkvantage". 834 835Due to limitations in the sysfs LED class, if the status of the LED 836indicators cannot be read due to an error, thinkpad-acpi will report it as 837a brightness of zero (same as LED off). 838 839If the thinkpad firmware doesn't support reading the current status, 840trying to read the current LED brightness will just return whatever 841brightness was last written to that attribute. 842 843These LEDs can blink using hardware acceleration. To request that a 844ThinkPad indicator LED should blink in hardware accelerated mode, use the 845"timer" trigger, and leave the delay_on and delay_off parameters set to 846zero (to request hardware acceleration autodetection). 847 848LEDs that are known not to exist in a given ThinkPad model are not 849made available through the sysfs interface. If you have a dock and you 850notice there are LEDs listed for your ThinkPad that do not exist (and 851are not in the dock), or if you notice that there are missing LEDs, 852a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. 853 854 855ACPI sounds -- /proc/acpi/ibm/beep 856---------------------------------- 857 858The BEEP method is used internally by the ACPI firmware to provide 859audible alerts in various situations. This feature allows the same 860sounds to be triggered manually. 861 862The commands are non-negative integer numbers:: 863 864 echo <number> >/proc/acpi/ibm/beep 865 866The valid <number> range is 0 to 17. Not all numbers trigger sounds 867and the sounds vary from model to model. Here is the behavior on the 868X40: 869 870 - 0 - stop a sound in progress (but use 17 to stop 16) 871 - 2 - two beeps, pause, third beep ("low battery") 872 - 3 - single beep 873 - 4 - high, followed by low-pitched beep ("unable") 874 - 5 - single beep 875 - 6 - very high, followed by high-pitched beep ("AC/DC") 876 - 7 - high-pitched beep 877 - 9 - three short beeps 878 - 10 - very long beep 879 - 12 - low-pitched beep 880 - 15 - three high-pitched beeps repeating constantly, stop with 0 881 - 16 - one medium-pitched beep repeating constantly, stop with 17 882 - 17 - stop 16 883 884 885Temperature sensors 886------------------- 887 888procfs: /proc/acpi/ibm/thermal 889 890sysfs device attributes: (hwmon "thinkpad") temp*_input 891 892Most ThinkPads include six or more separate temperature sensors but only 893expose the CPU temperature through the standard ACPI methods. This 894feature shows readings from up to eight different sensors on older 895ThinkPads, and up to sixteen different sensors on newer ThinkPads. 896 897For example, on the X40, a typical output may be: 898 899temperatures: 900 42 42 45 41 36 -128 33 -128 901 902On the T43/p, a typical output may be: 903 904temperatures: 905 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 906 907The mapping of thermal sensors to physical locations varies depending on 908system-board model (and thus, on ThinkPad model). 909 910https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that 911tries to track down these locations for various models. 912 913Most (newer?) models seem to follow this pattern: 914 915- 1: CPU 916- 2: (depends on model) 917- 3: (depends on model) 918- 4: GPU 919- 5: Main battery: main sensor 920- 6: Bay battery: main sensor 921- 7: Main battery: secondary sensor 922- 8: Bay battery: secondary sensor 923- 9-15: (depends on model) 924 925For the R51 (source: Thomas Gruber): 926 927- 2: Mini-PCI 928- 3: Internal HDD 929 930For the T43, T43/p (source: Shmidoax/Thinkwiki.org) 931https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p 932 933- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp 934- 3: PCMCIA slot 935- 9: MCH (northbridge) to DRAM Bus 936- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI 937 card, under touchpad 938- 11: Power regulator, underside of system board, below F2 key 939 940The A31 has a very atypical layout for the thermal sensors 941(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) 942 943- 1: CPU 944- 2: Main Battery: main sensor 945- 3: Power Converter 946- 4: Bay Battery: main sensor 947- 5: MCH (northbridge) 948- 6: PCMCIA/ambient 949- 7: Main Battery: secondary sensor 950- 8: Bay Battery: secondary sensor 951 952 953Procfs notes 954^^^^^^^^^^^^ 955 956 Readings from sensors that are not available return -128. 957 No commands can be written to this file. 958 959Sysfs notes 960^^^^^^^^^^^ 961 962 Sensors that are not available return the ENXIO error. This 963 status may change at runtime, as there are hotplug thermal 964 sensors, like those inside the batteries and docks. 965 966 thinkpad-acpi thermal sensors are reported through the hwmon 967 subsystem, and follow all of the hwmon guidelines at 968 Documentation/hwmon. 969 970EXPERIMENTAL: Embedded controller register dump 971----------------------------------------------- 972 973This feature is not included in the thinkpad driver anymore. 974Instead the EC can be accessed through /sys/kernel/debug/ec with 975a userspace tool which can be found here: 976ftp://ftp.suse.com/pub/people/trenn/sources/ec 977 978Use it to determine the register holding the fan 979speed on some models. To do that, do the following: 980 981 - make sure the battery is fully charged 982 - make sure the fan is running 983 - use above mentioned tool to read out the EC 984 985Often fan and temperature values vary between 986readings. Since temperatures don't change vary fast, you can take 987several quick dumps to eliminate them. 988 989You can use a similar method to figure out the meaning of other 990embedded controller registers - e.g. make sure nothing else changes 991except the charging or discharging battery to determine which 992registers contain the current battery capacity, etc. If you experiment 993with this, do send me your results (including some complete dumps with 994a description of the conditions when they were taken.) 995 996 997LCD brightness control 998---------------------- 999 1000procfs: /proc/acpi/ibm/brightness 1001 1002sysfs backlight device "thinkpad_screen" 1003 1004This feature allows software control of the LCD brightness on ThinkPad 1005models which don't have a hardware brightness slider. 1006 1007It has some limitations: the LCD backlight cannot be actually turned 1008on or off by this interface, it just controls the backlight brightness 1009level. 1010 1011On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control 1012has eight brightness levels, ranging from 0 to 7. Some of the levels 1013may not be distinct. Later Lenovo models that implement the ACPI 1014display backlight brightness control methods have 16 levels, ranging 1015from 0 to 15. 1016 1017For IBM ThinkPads, there are two interfaces to the firmware for direct 1018brightness control, EC and UCMS (or CMOS). To select which one should be 1019used, use the brightness_mode module parameter: brightness_mode=1 selects 1020EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC 1021mode with NVRAM backing (so that brightness changes are remembered across 1022shutdown/reboot). 1023 1024The driver tries to select which interface to use from a table of 1025defaults for each ThinkPad model. If it makes a wrong choice, please 1026report this as a bug, so that we can fix it. 1027 1028Lenovo ThinkPads only support brightness_mode=2 (UCMS). 1029 1030When display backlight brightness controls are available through the 1031standard ACPI interface, it is best to use it instead of this direct 1032ThinkPad-specific interface. The driver will disable its native 1033backlight brightness control interface if it detects that the standard 1034ACPI interface is available in the ThinkPad. 1035 1036If you want to use the thinkpad-acpi backlight brightness control 1037instead of the generic ACPI video backlight brightness control for some 1038reason, you should use the acpi_backlight=vendor kernel parameter. 1039 1040The brightness_enable module parameter can be used to control whether 1041the LCD brightness control feature will be enabled when available. 1042brightness_enable=0 forces it to be disabled. brightness_enable=1 1043forces it to be enabled when available, even if the standard ACPI 1044interface is also available. 1045 1046Procfs notes 1047^^^^^^^^^^^^ 1048 1049The available commands are:: 1050 1051 echo up >/proc/acpi/ibm/brightness 1052 echo down >/proc/acpi/ibm/brightness 1053 echo 'level <level>' >/proc/acpi/ibm/brightness 1054 1055Sysfs notes 1056^^^^^^^^^^^ 1057 1058The interface is implemented through the backlight sysfs class, which is 1059poorly documented at this time. 1060 1061Locate the thinkpad_screen device under /sys/class/backlight, and inside 1062it there will be the following attributes: 1063 1064 max_brightness: 1065 Reads the maximum brightness the hardware can be set to. 1066 The minimum is always zero. 1067 1068 actual_brightness: 1069 Reads what brightness the screen is set to at this instant. 1070 1071 brightness: 1072 Writes request the driver to change brightness to the 1073 given value. Reads will tell you what brightness the 1074 driver is trying to set the display to when "power" is set 1075 to zero and the display has not been dimmed by a kernel 1076 power management event. 1077 1078 power: 1079 power management mode, where 0 is "display on", and 1 to 3 1080 will dim the display backlight to brightness level 0 1081 because thinkpad-acpi cannot really turn the backlight 1082 off. Kernel power management events can temporarily 1083 increase the current power management level, i.e. they can 1084 dim the display. 1085 1086 1087WARNING: 1088 1089 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change 1090 interface and the ACPI-based backlight level change interface 1091 (available on newer BIOSes, and driven by the Linux ACPI video driver) 1092 at the same time. The two will interact in bad ways, do funny things, 1093 and maybe reduce the life of the backlight lamps by needlessly kicking 1094 its level up and down at every change. 1095 1096 1097Volume control (Console Audio control) 1098-------------------------------------- 1099 1100procfs: /proc/acpi/ibm/volume 1101 1102ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" 1103 1104NOTE: by default, the volume control interface operates in read-only 1105mode, as it is supposed to be used for on-screen-display purposes. 1106The read/write mode can be enabled through the use of the 1107"volume_control=1" module parameter. 1108 1109NOTE: distros are urged to not enable volume_control by default, this 1110should be done by the local admin only. The ThinkPad UI is for the 1111console audio control to be done through the volume keys only, and for 1112the desktop environment to just provide on-screen-display feedback. 1113Software volume control should be done only in the main AC97/HDA 1114mixer. 1115 1116 1117About the ThinkPad Console Audio control 1118^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1119 1120ThinkPads have a built-in amplifier and muting circuit that drives the 1121console headphone and speakers. This circuit is after the main AC97 1122or HDA mixer in the audio path, and under exclusive control of the 1123firmware. 1124 1125ThinkPads have three special hotkeys to interact with the console 1126audio control: volume up, volume down and mute. 1127 1128It is worth noting that the normal way the mute function works (on 1129ThinkPads that do not have a "mute LED") is: 1130 11311. Press mute to mute. It will *always* mute, you can press it as 1132 many times as you want, and the sound will remain mute. 1133 11342. Press either volume key to unmute the ThinkPad (it will _not_ 1135 change the volume, it will just unmute). 1136 1137This is a very superior design when compared to the cheap software-only 1138mute-toggle solution found on normal consumer laptops: you can be 1139absolutely sure the ThinkPad will not make noise if you press the mute 1140button, no matter the previous state. 1141 1142The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain 1143amplifiers driving the speakers and headphone output, and the firmware 1144also handles volume control for the headphone and speakers on these 1145ThinkPads without any help from the operating system (this volume 1146control stage exists after the main AC97 or HDA mixer in the audio 1147path). 1148 1149The newer Lenovo models only have firmware mute control, and depend on 1150the main HDA mixer to do volume control (which is done by the operating 1151system). In this case, the volume keys are filtered out for unmute 1152key press (there are some firmware bugs in this area) and delivered as 1153normal key presses to the operating system (thinkpad-acpi is not 1154involved). 1155 1156 1157The ThinkPad-ACPI volume control 1158^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1159 1160The preferred way to interact with the Console Audio control is the 1161ALSA interface. 1162 1163The legacy procfs interface allows one to read the current state, 1164and if volume control is enabled, accepts the following commands:: 1165 1166 echo up >/proc/acpi/ibm/volume 1167 echo down >/proc/acpi/ibm/volume 1168 echo mute >/proc/acpi/ibm/volume 1169 echo unmute >/proc/acpi/ibm/volume 1170 echo 'level <level>' >/proc/acpi/ibm/volume 1171 1172The <level> number range is 0 to 14 although not all of them may be 1173distinct. To unmute the volume after the mute command, use either the 1174up or down command (the level command will not unmute the volume), or 1175the unmute command. 1176 1177You can use the volume_capabilities parameter to tell the driver 1178whether your thinkpad has volume control or mute-only control: 1179volume_capabilities=1 for mixers with mute and volume control, 1180volume_capabilities=2 for mixers with only mute control. 1181 1182If the driver misdetects the capabilities for your ThinkPad model, 1183please report this to ibm-acpi-devel@lists.sourceforge.net, so that we 1184can update the driver. 1185 1186There are two strategies for volume control. To select which one 1187should be used, use the volume_mode module parameter: volume_mode=1 1188selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing 1189(so that volume/mute changes are remembered across shutdown/reboot). 1190 1191The driver will operate in volume_mode=3 by default. If that does not 1192work well on your ThinkPad model, please report this to 1193ibm-acpi-devel@lists.sourceforge.net. 1194 1195The driver supports the standard ALSA module parameters. If the ALSA 1196mixer is disabled, the driver will disable all volume functionality. 1197 1198 1199Fan control and monitoring: fan speed, fan enable/disable 1200--------------------------------------------------------- 1201 1202procfs: /proc/acpi/ibm/fan 1203 1204sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input 1205 1206sysfs hwmon driver attributes: fan_watchdog 1207 1208NOTE NOTE NOTE: 1209 fan control operations are disabled by default for 1210 safety reasons. To enable them, the module parameter "fan_control=1" 1211 must be given to thinkpad-acpi. 1212 1213This feature attempts to show the current fan speed, control mode and 1214other fan data that might be available. The speed is read directly 1215from the hardware registers of the embedded controller. This is known 1216to work on later R, T, X and Z series ThinkPads but may show a bogus 1217value on other models. 1218 1219Some Lenovo ThinkPads support a secondary fan. This fan cannot be 1220controlled separately, it shares the main fan control. 1221 1222Fan levels 1223^^^^^^^^^^ 1224 1225Most ThinkPad fans work in "levels" at the firmware interface. Level 0 1226stops the fan. The higher the level, the higher the fan speed, although 1227adjacent levels often map to the same fan speed. 7 is the highest 1228level, where the fan reaches the maximum recommended speed. 1229 1230Level "auto" means the EC changes the fan level according to some 1231internal algorithm, usually based on readings from the thermal sensors. 1232 1233There is also a "full-speed" level, also known as "disengaged" level. 1234In this level, the EC disables the speed-locked closed-loop fan control, 1235and drives the fan as fast as it can go, which might exceed hardware 1236limits, so use this level with caution. 1237 1238The fan usually ramps up or down slowly from one speed to another, and 1239it is normal for the EC to take several seconds to react to fan 1240commands. The full-speed level may take up to two minutes to ramp up to 1241maximum speed, and in some ThinkPads, the tachometer readings go stale 1242while the EC is transitioning to the full-speed level. 1243 1244WARNING WARNING WARNING: do not leave the fan disabled unless you are 1245monitoring all of the temperature sensor readings and you are ready to 1246enable it if necessary to avoid overheating. 1247 1248An enabled fan in level "auto" may stop spinning if the EC decides the 1249ThinkPad is cool enough and doesn't need the extra airflow. This is 1250normal, and the EC will spin the fan up if the various thermal readings 1251rise too much. 1252 1253On the X40, this seems to depend on the CPU and HDD temperatures. 1254Specifically, the fan is turned on when either the CPU temperature 1255climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The 1256fan is turned off when the CPU temperature drops to 49 degrees and the 1257HDD temperature drops to 41 degrees. These thresholds cannot 1258currently be controlled. 1259 1260The ThinkPad's ACPI DSDT code will reprogram the fan on its own when 1261certain conditions are met. It will override any fan programming done 1262through thinkpad-acpi. 1263 1264The thinkpad-acpi kernel driver can be programmed to revert the fan 1265level to a safe setting if userspace does not issue one of the procfs 1266fan commands: "enable", "disable", "level" or "watchdog", or if there 1267are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is 1268set to 1, manual mode) within a configurable amount of time of up to 1269120 seconds. This functionality is called fan safety watchdog. 1270 1271Note that the watchdog timer stops after it enables the fan. It will be 1272rearmed again automatically (using the same interval) when one of the 1273above mentioned fan commands is received. The fan watchdog is, 1274therefore, not suitable to protect against fan mode changes made through 1275means other than the "enable", "disable", and "level" procfs fan 1276commands, or the hwmon fan control sysfs interface. 1277 1278Procfs notes 1279^^^^^^^^^^^^ 1280 1281The fan may be enabled or disabled with the following commands:: 1282 1283 echo enable >/proc/acpi/ibm/fan 1284 echo disable >/proc/acpi/ibm/fan 1285 1286Placing a fan on level 0 is the same as disabling it. Enabling a fan 1287will try to place it in a safe level if it is too slow or disabled. 1288 1289The fan level can be controlled with the command:: 1290 1291 echo 'level <level>' > /proc/acpi/ibm/fan 1292 1293Where <level> is an integer from 0 to 7, or one of the words "auto" or 1294"full-speed" (without the quotes). Not all ThinkPads support the "auto" 1295and "full-speed" levels. The driver accepts "disengaged" as an alias for 1296"full-speed", and reports it as "disengaged" for backwards 1297compatibility. 1298 1299On the X31 and X40 (and ONLY on those models), the fan speed can be 1300controlled to a certain degree. Once the fan is running, it can be 1301forced to run faster or slower with the following command:: 1302 1303 echo 'speed <speed>' > /proc/acpi/ibm/fan 1304 1305The sustainable range of fan speeds on the X40 appears to be from about 13063700 to about 7350. Values outside this range either do not have any 1307effect or the fan speed eventually settles somewhere in that range. The 1308fan cannot be stopped or started with this command. This functionality 1309is incomplete, and not available through the sysfs interface. 1310 1311To program the safety watchdog, use the "watchdog" command:: 1312 1313 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan 1314 1315If you want to disable the watchdog, use 0 as the interval. 1316 1317Sysfs notes 1318^^^^^^^^^^^ 1319 1320The sysfs interface follows the hwmon subsystem guidelines for the most 1321part, and the exception is the fan safety watchdog. 1322 1323Writes to any of the sysfs attributes may return the EINVAL error if 1324that operation is not supported in a given ThinkPad or if the parameter 1325is out-of-bounds, and EPERM if it is forbidden. They may also return 1326EINTR (interrupted system call), and EIO (I/O error while trying to talk 1327to the firmware). 1328 1329Features not yet implemented by the driver return ENOSYS. 1330 1331hwmon device attribute pwm1_enable: 1332 - 0: PWM offline (fan is set to full-speed mode) 1333 - 1: Manual PWM control (use pwm1 to set fan level) 1334 - 2: Hardware PWM control (EC "auto" mode) 1335 - 3: reserved (Software PWM control, not implemented yet) 1336 1337 Modes 0 and 2 are not supported by all ThinkPads, and the 1338 driver is not always able to detect this. If it does know a 1339 mode is unsupported, it will return -EINVAL. 1340 1341hwmon device attribute pwm1: 1342 Fan level, scaled from the firmware values of 0-7 to the hwmon 1343 scale of 0-255. 0 means fan stopped, 255 means highest normal 1344 speed (level 7). 1345 1346 This attribute only commands the fan if pmw1_enable is set to 1 1347 (manual PWM control). 1348 1349hwmon device attribute fan1_input: 1350 Fan tachometer reading, in RPM. May go stale on certain 1351 ThinkPads while the EC transitions the PWM to offline mode, 1352 which can take up to two minutes. May return rubbish on older 1353 ThinkPads. 1354 1355hwmon device attribute fan2_input: 1356 Fan tachometer reading, in RPM, for the secondary fan. 1357 Available only on some ThinkPads. If the secondary fan is 1358 not installed, will always read 0. 1359 1360hwmon driver attribute fan_watchdog: 1361 Fan safety watchdog timer interval, in seconds. Minimum is 1362 1 second, maximum is 120 seconds. 0 disables the watchdog. 1363 1364To stop the fan: set pwm1 to zero, and pwm1_enable to 1. 1365 1366To start the fan in a safe mode: set pwm1_enable to 2. If that fails 1367with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255 1368would be the safest choice, though). 1369 1370 1371WAN 1372--- 1373 1374procfs: /proc/acpi/ibm/wan 1375 1376sysfs device attribute: wwan_enable (deprecated) 1377 1378sysfs rfkill class: switch "tpacpi_wwan_sw" 1379 1380This feature shows the presence and current state of the built-in 1381Wireless WAN device. 1382 1383If the ThinkPad supports it, the WWAN state is stored in NVRAM, 1384so it is kept across reboots and power-off. 1385 1386It was tested on a Lenovo ThinkPad X60. It should probably work on other 1387ThinkPad models which come with this module installed. 1388 1389Procfs notes 1390^^^^^^^^^^^^ 1391 1392If the W-WAN card is installed, the following commands can be used:: 1393 1394 echo enable > /proc/acpi/ibm/wan 1395 echo disable > /proc/acpi/ibm/wan 1396 1397Sysfs notes 1398^^^^^^^^^^^ 1399 1400 If the W-WAN card is installed, it can be enabled / 1401 disabled through the "wwan_enable" thinkpad-acpi device 1402 attribute, and its current status can also be queried. 1403 1404 enable: 1405 - 0: disables WWAN card / WWAN card is disabled 1406 - 1: enables WWAN card / WWAN card is enabled. 1407 1408 Note: this interface has been superseded by the generic rfkill 1409 class. It has been deprecated, and it will be removed in year 1410 2010. 1411 1412 rfkill controller switch "tpacpi_wwan_sw": refer to 1413 Documentation/driver-api/rfkill.rst for details. 1414 1415 1416LCD Shadow control 1417------------------ 1418 1419procfs: /proc/acpi/ibm/lcdshadow 1420 1421Some newer T480s and T490s ThinkPads provide a feature called 1422PrivacyGuard. By turning this feature on, the usable vertical and 1423horizontal viewing angles of the LCD can be limited (as if some privacy 1424screen was applied manually in front of the display). 1425 1426procfs notes 1427^^^^^^^^^^^^ 1428 1429The available commands are:: 1430 1431 echo '0' >/proc/acpi/ibm/lcdshadow 1432 echo '1' >/proc/acpi/ibm/lcdshadow 1433 1434The first command ensures the best viewing angle and the latter one turns 1435on the feature, restricting the viewing angles. 1436 1437 1438DYTC Lapmode sensor 1439------------------- 1440 1441sysfs: dytc_lapmode 1442 1443Newer thinkpads and mobile workstations have the ability to determine if 1444the device is in deskmode or lapmode. This feature is used by user space 1445to decide if WWAN transmission can be increased to maximum power and is 1446also useful for understanding the different thermal modes available as 1447they differ between desk and lap mode. 1448 1449The property is read-only. If the platform doesn't have support the sysfs 1450class is not created. 1451 1452EXPERIMENTAL: UWB 1453----------------- 1454 1455This feature is considered EXPERIMENTAL because it has not been extensively 1456tested and validated in various ThinkPad models yet. The feature may not 1457work as expected. USE WITH CAUTION! To use this feature, you need to supply 1458the experimental=1 parameter when loading the module. 1459 1460sysfs rfkill class: switch "tpacpi_uwb_sw" 1461 1462This feature exports an rfkill controller for the UWB device, if one is 1463present and enabled in the BIOS. 1464 1465Sysfs notes 1466^^^^^^^^^^^ 1467 1468 rfkill controller switch "tpacpi_uwb_sw": refer to 1469 Documentation/driver-api/rfkill.rst for details. 1470 1471 1472Setting keyboard language 1473------------------------- 1474 1475sysfs: keyboard_lang 1476 1477This feature is used to set keyboard language to ECFW using ASL interface. 1478Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(', 1479")" numeric keys, which are not displaying correctly, when keyboard language 1480is other than "english". This is because the default keyboard language in ECFW 1481is set as "english". Hence using this sysfs, user can set the correct keyboard 1482language to ECFW and then these key's will work correctly. 1483 1484Example of command to set keyboard language is mentioned below:: 1485 1486 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang 1487 1488Text corresponding to keyboard layout to be set in sysfs are: be(Belgian), 1489cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian), 1490fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan), 1491nl(Dutch), nn(Norway), pl(Polish), pt(portugese), sl(Slovenian), sv(Sweden), 1492tr(Turkey) 1493 1494WWAN Antenna type 1495----------------- 1496 1497sysfs: wwan_antenna_type 1498 1499On some newer Thinkpads we need to set SAR value based on the antenna 1500type. This interface will be used by userspace to get the antenna type 1501and set the corresponding SAR value, as is required for FCC certification. 1502 1503The available commands are:: 1504 1505 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type 1506 1507Currently 2 antenna types are supported as mentioned below: 1508- type a 1509- type b 1510 1511The property is read-only. If the platform doesn't have support the sysfs 1512class is not created. 1513 1514Adaptive keyboard 1515----------------- 1516 1517sysfs device attribute: adaptive_kbd_mode 1518 1519This sysfs attribute controls the keyboard "face" that will be shown on the 1520Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read 1521and set. 1522 1523- 0 = Home mode 1524- 1 = Web-browser mode 1525- 2 = Web-conference mode 1526- 3 = Function mode 1527- 4 = Layflat mode 1528 1529For more details about which buttons will appear depending on the mode, please 1530review the laptop's user guide: 1531https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf 1532 1533Battery charge control 1534---------------------- 1535 1536sysfs attributes: 1537/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold 1538 1539These two attributes are created for those batteries that are supported by the 1540driver. They enable the user to control the battery charge thresholds of the 1541given battery. Both values may be read and set. `charge_control_start_threshold` 1542accepts an integer between 0 and 99 (inclusive); this value represents a battery 1543percentage level, below which charging will begin. `charge_control_end_threshold` 1544accepts an integer between 1 and 100 (inclusive); this value represents a battery 1545percentage level, above which charging will stop. 1546 1547The exact semantics of the attributes may be found in 1548Documentation/ABI/testing/sysfs-class-power. 1549 1550Multiple Commands, Module Parameters 1551------------------------------------ 1552 1553Multiple commands can be written to the proc files in one shot by 1554separating them with commas, for example:: 1555 1556 echo enable,0xffff > /proc/acpi/ibm/hotkey 1557 echo lcd_disable,crt_enable > /proc/acpi/ibm/video 1558 1559Commands can also be specified when loading the thinkpad-acpi module, 1560for example:: 1561 1562 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable 1563 1564 1565Enabling debugging output 1566------------------------- 1567 1568The module takes a debug parameter which can be used to selectively 1569enable various classes of debugging output, for example:: 1570 1571 modprobe thinkpad_acpi debug=0xffff 1572 1573will enable all debugging output classes. It takes a bitmask, so 1574to enable more than one output class, just add their values. 1575 1576 ============= ====================================== 1577 Debug bitmask Description 1578 ============= ====================================== 1579 0x8000 Disclose PID of userspace programs 1580 accessing some functions of the driver 1581 0x0001 Initialization and probing 1582 0x0002 Removal 1583 0x0004 RF Transmitter control (RFKILL) 1584 (bluetooth, WWAN, UWB...) 1585 0x0008 HKEY event interface, hotkeys 1586 0x0010 Fan control 1587 0x0020 Backlight brightness 1588 0x0040 Audio mixer/volume control 1589 ============= ====================================== 1590 1591There is also a kernel build option to enable more debugging 1592information, which may be necessary to debug driver problems. 1593 1594The level of debugging information output by the driver can be changed 1595at runtime through sysfs, using the driver attribute debug_level. The 1596attribute takes the same bitmask as the debug module parameter above. 1597 1598 1599Force loading of module 1600----------------------- 1601 1602If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify 1603the module parameter force_load=1. Regardless of whether this works or 1604not, please contact ibm-acpi-devel@lists.sourceforge.net with a report. 1605 1606 1607Sysfs interface changelog 1608^^^^^^^^^^^^^^^^^^^^^^^^^ 1609 1610========= =============================================================== 16110x000100: Initial sysfs support, as a single platform driver and 1612 device. 16130x000200: Hot key support for 32 hot keys, and radio slider switch 1614 support. 16150x010000: Hot keys are now handled by default over the input 1616 layer, the radio switch generates input event EV_RADIO, 1617 and the driver enables hot key handling by default in 1618 the firmware. 1619 16200x020000: ABI fix: added a separate hwmon platform device and 1621 driver, which must be located by name (thinkpad) 1622 and the hwmon class for libsensors4 (lm-sensors 3) 1623 compatibility. Moved all hwmon attributes to this 1624 new platform device. 1625 16260x020100: Marker for thinkpad-acpi with hot key NVRAM polling 1627 support. If you must, use it to know you should not 1628 start a userspace NVRAM poller (allows to detect when 1629 NVRAM is compiled out by the user because it is 1630 unneeded/undesired in the first place). 16310x020101: Marker for thinkpad-acpi with hot key NVRAM polling 1632 and proper hotkey_mask semantics (version 8 of the 1633 NVRAM polling patch). Some development snapshots of 1634 0.18 had an earlier version that did strange things 1635 to hotkey_mask. 1636 16370x020200: Add poll()/select() support to the following attributes: 1638 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason 1639 16400x020300: hotkey enable/disable support removed, attributes 1641 hotkey_bios_enabled and hotkey_enable deprecated and 1642 marked for removal. 1643 16440x020400: Marker for 16 LEDs support. Also, LEDs that are known 1645 to not exist in a given model are not registered with 1646 the LED sysfs class anymore. 1647 16480x020500: Updated hotkey driver, hotkey_mask is always available 1649 and it is always able to disable hot keys. Very old 1650 thinkpads are properly supported. hotkey_bios_mask 1651 is deprecated and marked for removal. 1652 16530x020600: Marker for backlight change event support. 1654 16550x020700: Support for mute-only mixers. 1656 Volume control in read-only mode by default. 1657 Marker for ALSA mixer support. 1658 16590x030000: Thermal and fan sysfs attributes were moved to the hwmon 1660 device instead of being attached to the backing platform 1661 device. 1662========= =============================================================== 1663