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 - Hardware damage detection capability 58 59A compatibility table by model and feature is maintained on the web 60site, http://ibm-acpi.sf.net/. I appreciate any success or failure 61reports, especially if they add to or correct the compatibility table. 62Please include the following information in your report: 63 64 - ThinkPad model name 65 - a copy of your ACPI tables, using the "acpidump" utility 66 - a copy of the output of dmidecode, with serial numbers 67 and UUIDs masked off 68 - which driver features work and which don't 69 - the observed behavior of non-working features 70 71Any other comments or patches are also more than welcome. 72 73 74Installation 75------------ 76 77If you are compiling this driver as included in the Linux kernel 78sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. 79It is located on the menu path: "Device Drivers" -> "X86 Platform 80Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". 81 82 83Features 84-------- 85 86The driver exports two different interfaces to userspace, which can be 87used to access the features it provides. One is a legacy procfs-based 88interface, which will be removed at some time in the future. The other 89is a new sysfs-based interface which is not complete yet. 90 91The procfs interface creates the /proc/acpi/ibm directory. There is a 92file under that directory for each feature it supports. The procfs 93interface is mostly frozen, and will change very little if at all: it 94will not be extended to add any new functionality in the driver, instead 95all new functionality will be implemented on the sysfs interface. 96 97The sysfs interface tries to blend in the generic Linux sysfs subsystems 98and classes as much as possible. Since some of these subsystems are not 99yet ready or stabilized, it is expected that this interface will change, 100and any and all userspace programs must deal with it. 101 102 103Notes about the sysfs interface 104^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 105 106Unlike what was done with the procfs interface, correctness when talking 107to the sysfs interfaces will be enforced, as will correctness in the 108thinkpad-acpi's implementation of sysfs interfaces. 109 110Also, any bugs in the thinkpad-acpi sysfs driver code or in the 111thinkpad-acpi's implementation of the sysfs interfaces will be fixed for 112maximum correctness, even if that means changing an interface in 113non-compatible ways. As these interfaces mature both in the kernel and 114in thinkpad-acpi, such changes should become quite rare. 115 116Applications interfacing to the thinkpad-acpi sysfs interfaces must 117follow all sysfs guidelines and correctly process all errors (the sysfs 118interface makes extensive use of errors). File descriptors and open / 119close operations to the sysfs inodes must also be properly implemented. 120 121The version of thinkpad-acpi's sysfs interface is exported by the driver 122as a driver attribute (see below). 123 124Sysfs driver attributes are on the driver's sysfs attribute space, 125for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and 126/sys/bus/platform/drivers/thinkpad_hwmon/ 127 128Sysfs device attributes are on the thinkpad_acpi device sysfs attribute 129space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. 130 131Sysfs device attributes for the sensors and fan are on the 132thinkpad_hwmon device's sysfs attribute space, but you should locate it 133looking for a hwmon device with the name attribute of "thinkpad", or 134better yet, through libsensors. For 4.14+ sysfs attributes were moved to the 135hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or 136/sys/class/hwmon/hwmon?). 137 138Driver version 139-------------- 140 141procfs: /proc/acpi/ibm/driver 142 143sysfs driver attribute: version 144 145The driver name and version. No commands can be written to this file. 146 147 148Sysfs interface version 149----------------------- 150 151sysfs driver attribute: interface_version 152 153Version of the thinkpad-acpi sysfs interface, as an unsigned long 154(output in hex format: 0xAAAABBCC), where: 155 156 AAAA 157 - major revision 158 BB 159 - minor revision 160 CC 161 - bugfix revision 162 163The sysfs interface version changelog for the driver can be found at the 164end of this document. Changes to the sysfs interface done by the kernel 165subsystems are not documented here, nor are they tracked by this 166attribute. 167 168Changes to the thinkpad-acpi sysfs interface are only considered 169non-experimental when they are submitted to Linux mainline, at which 170point the changes in this interface are documented and interface_version 171may be updated. If you are using any thinkpad-acpi features not yet 172sent to mainline for merging, you do so on your own risk: these features 173may disappear, or be implemented in a different and incompatible way by 174the time they are merged in Linux mainline. 175 176Changes that are backwards-compatible by nature (e.g. the addition of 177attributes that do not change the way the other attributes work) do not 178always warrant an update of interface_version. Therefore, one must 179expect that an attribute might not be there, and deal with it properly 180(an attribute not being there *is* a valid way to make it clear that a 181feature is not available in sysfs). 182 183 184Hot keys 185-------- 186 187procfs: /proc/acpi/ibm/hotkey 188 189sysfs device attribute: hotkey_* 190 191In a ThinkPad, the ACPI HKEY handler is responsible for communicating 192some important events and also keyboard hot key presses to the operating 193system. Enabling the hotkey functionality of thinkpad-acpi signals the 194firmware that such a driver is present, and modifies how the ThinkPad 195firmware will behave in many situations. 196 197The driver enables the HKEY ("hot key") event reporting automatically 198when loaded, and disables it when it is removed. 199 200The driver will report HKEY events in the following format:: 201 202 ibm/hotkey HKEY 00000080 0000xxxx 203 204Some of these events refer to hot key presses, but not all of them. 205 206The driver will generate events over the input layer for hot keys and 207radio switches, and over the ACPI netlink layer for other events. The 208input layer support accepts the standard IOCTLs to remap the keycodes 209assigned to each hot key. 210 211The hot key bit mask allows some control over which hot keys generate 212events. If a key is "masked" (bit set to 0 in the mask), the firmware 213will handle it. If it is "unmasked", it signals the firmware that 214thinkpad-acpi would prefer to handle it, if the firmware would be so 215kind to allow it (and it often doesn't!). 216 217Not all bits in the mask can be modified. Not all bits that can be 218modified do anything. Not all hot keys can be individually controlled 219by the mask. Some models do not support the mask at all. The behaviour 220of the mask is, therefore, highly dependent on the ThinkPad model. 221 222The driver will filter out any unmasked hotkeys, so even if the firmware 223doesn't allow disabling an specific hotkey, the driver will not report 224events for unmasked hotkeys. 225 226Note that unmasking some keys prevents their default behavior. For 227example, if Fn+F5 is unmasked, that key will no longer enable/disable 228Bluetooth by itself in firmware. 229 230Note also that not all Fn key combinations are supported through ACPI 231depending on the ThinkPad model and firmware version. On those 232ThinkPads, it is still possible to support some extra hotkeys by 233polling the "CMOS NVRAM" at least 10 times per second. The driver 234attempts to enables this functionality automatically when required. 235 236procfs notes 237^^^^^^^^^^^^ 238 239The following commands can be written to the /proc/acpi/ibm/hotkey file:: 240 241 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys 242 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys 243 ... any other 8-hex-digit mask ... 244 echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask 245 246The following commands have been deprecated and will cause the kernel 247to log a warning:: 248 249 echo enable > /proc/acpi/ibm/hotkey -- does nothing 250 echo disable > /proc/acpi/ibm/hotkey -- returns an error 251 252The procfs interface does not support NVRAM polling control. So as to 253maintain maximum bug-to-bug compatibility, it does not report any masks, 254nor does it allow one to manipulate the hot key mask when the firmware 255does not support masks at all, even if NVRAM polling is in use. 256 257sysfs notes 258^^^^^^^^^^^ 259 260 hotkey_bios_enabled: 261 DEPRECATED, WILL BE REMOVED SOON. 262 263 Returns 0. 264 265 hotkey_bios_mask: 266 DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE. 267 268 Returns the hot keys mask when thinkpad-acpi was loaded. 269 Upon module unload, the hot keys mask will be restored 270 to this value. This is always 0x80c, because those are 271 the hotkeys that were supported by ancient firmware 272 without mask support. 273 274 hotkey_enable: 275 DEPRECATED, WILL BE REMOVED SOON. 276 277 0: returns -EPERM 278 1: does nothing 279 280 hotkey_mask: 281 bit mask to enable reporting (and depending on 282 the firmware, ACPI event generation) for each hot key 283 (see above). Returns the current status of the hot keys 284 mask, and allows one to modify it. 285 286 hotkey_all_mask: 287 bit mask that should enable event reporting for all 288 supported hot keys, when echoed to hotkey_mask above. 289 Unless you know which events need to be handled 290 passively (because the firmware *will* handle them 291 anyway), do *not* use hotkey_all_mask. Use 292 hotkey_recommended_mask, instead. You have been warned. 293 294 hotkey_recommended_mask: 295 bit mask that should enable event reporting for all 296 supported hot keys, except those which are always 297 handled by the firmware anyway. Echo it to 298 hotkey_mask above, to use. This is the default mask 299 used by the driver. 300 301 hotkey_source_mask: 302 bit mask that selects which hot keys will the driver 303 poll the NVRAM for. This is auto-detected by the driver 304 based on the capabilities reported by the ACPI firmware, 305 but it can be overridden at runtime. 306 307 Hot keys whose bits are set in hotkey_source_mask are 308 polled for in NVRAM, and reported as hotkey events if 309 enabled in hotkey_mask. Only a few hot keys are 310 available through CMOS NVRAM polling. 311 312 Warning: when in NVRAM mode, the volume up/down/mute 313 keys are synthesized according to changes in the mixer, 314 which uses a single volume up or volume down hotkey 315 press to unmute, as per the ThinkPad volume mixer user 316 interface. When in ACPI event mode, volume up/down/mute 317 events are reported by the firmware and can behave 318 differently (and that behaviour changes with firmware 319 version -- not just with firmware models -- as well as 320 OSI(Linux) state). 321 322 hotkey_poll_freq: 323 frequency in Hz for hot key polling. It must be between 324 0 and 25 Hz. Polling is only carried out when strictly 325 needed. 326 327 Setting hotkey_poll_freq to zero disables polling, and 328 will cause hot key presses that require NVRAM polling 329 to never be reported. 330 331 Setting hotkey_poll_freq too low may cause repeated 332 pressings of the same hot key to be misreported as a 333 single key press, or to not even be detected at all. 334 The recommended polling frequency is 10Hz. 335 336 hotkey_radio_sw: 337 If the ThinkPad has a hardware radio switch, this 338 attribute will read 0 if the switch is in the "radios 339 disabled" position, and 1 if the switch is in the 340 "radios enabled" position. 341 342 This attribute has poll()/select() support. 343 344 hotkey_tablet_mode: 345 If the ThinkPad has tablet capabilities, this attribute 346 will read 0 if the ThinkPad is in normal mode, and 347 1 if the ThinkPad is in tablet mode. 348 349 This attribute has poll()/select() support. 350 351 wakeup_reason: 352 Set to 1 if the system is waking up because the user 353 requested a bay ejection. Set to 2 if the system is 354 waking up because the user requested the system to 355 undock. Set to zero for normal wake-ups or wake-ups 356 due to unknown reasons. 357 358 This attribute has poll()/select() support. 359 360 wakeup_hotunplug_complete: 361 Set to 1 if the system was waken up because of an 362 undock or bay ejection request, and that request 363 was successfully completed. At this point, it might 364 be useful to send the system back to sleep, at the 365 user's choice. Refer to HKEY events 0x4003 and 366 0x3003, below. 367 368 This attribute has poll()/select() support. 369 370input layer notes 371^^^^^^^^^^^^^^^^^ 372 373A Hot key is mapped to a single input layer EV_KEY event, possibly 374followed by an EV_MSC MSC_SCAN event that shall contain that key's scan 375code. An EV_SYN event will always be generated to mark the end of the 376event block. 377 378Do not use the EV_MSC MSC_SCAN events to process keys. They are to be 379used as a helper to remap keys, only. They are particularly useful when 380remapping KEY_UNKNOWN keys. 381 382The events are available in an input device, with the following id: 383 384 ============== ============================== 385 Bus BUS_HOST 386 vendor 0x1014 (PCI_VENDOR_ID_IBM) or 387 0x17aa (PCI_VENDOR_ID_LENOVO) 388 product 0x5054 ("TP") 389 version 0x4101 390 ============== ============================== 391 392The version will have its LSB incremented if the keymap changes in a 393backwards-compatible way. The MSB shall always be 0x41 for this input 394device. If the MSB is not 0x41, do not use the device as described in 395this section, as it is either something else (e.g. another input device 396exported by a thinkpad driver, such as HDAPS) or its functionality has 397been changed in a non-backwards compatible way. 398 399Adding other event types for other functionalities shall be considered a 400backwards-compatible change for this input device. 401 402Thinkpad-acpi Hot Key event map (version 0x4101): 403 404======= ======= ============== ============================================== 405ACPI Scan 406event code Key Notes 407======= ======= ============== ============================================== 4080x1001 0x00 FN+F1 - 409 4100x1002 0x01 FN+F2 IBM: battery (rare) 411 Lenovo: Screen lock 412 4130x1003 0x02 FN+F3 Many IBM models always report 414 this hot key, even with hot keys 415 disabled or with Fn+F3 masked 416 off 417 IBM: screen lock, often turns 418 off the ThinkLight as side-effect 419 Lenovo: battery 420 4210x1004 0x03 FN+F4 Sleep button (ACPI sleep button 422 semantics, i.e. sleep-to-RAM). 423 It always generates some kind 424 of event, either the hot key 425 event or an ACPI sleep button 426 event. The firmware may 427 refuse to generate further FN+F4 428 key presses until a S3 or S4 ACPI 429 sleep cycle is performed or some 430 time passes. 431 4320x1005 0x04 FN+F5 Radio. Enables/disables 433 the internal Bluetooth hardware 434 and W-WAN card if left in control 435 of the firmware. Does not affect 436 the WLAN card. 437 Should be used to turn on/off all 438 radios (Bluetooth+W-WAN+WLAN), 439 really. 440 4410x1006 0x05 FN+F6 - 442 4430x1007 0x06 FN+F7 Video output cycle. 444 Do you feel lucky today? 445 4460x1008 0x07 FN+F8 IBM: toggle screen expand 447 Lenovo: configure UltraNav, 448 or toggle screen expand. 449 On 2024 platforms replaced by 450 0x131f (see below) and on newer 451 platforms (2025 +) keycode is 452 replaced by 0x1401 (see below). 453 4540x1009 0x08 FN+F9 - 455 456... ... ... ... 457 4580x100B 0x0A FN+F11 - 459 4600x100C 0x0B FN+F12 Sleep to disk. You are always 461 supposed to handle it yourself, 462 either through the ACPI event, 463 or through a hotkey event. 464 The firmware may refuse to 465 generate further FN+F12 key 466 press events until a S3 or S4 467 ACPI sleep cycle is performed, 468 or some time passes. 469 4700x100D 0x0C FN+BACKSPACE - 4710x100E 0x0D FN+INSERT - 4720x100F 0x0E FN+DELETE - 473 4740x1010 0x0F FN+HOME Brightness up. This key is 475 always handled by the firmware 476 in IBM ThinkPads, even when 477 unmasked. Just leave it alone. 478 For Lenovo ThinkPads with a new 479 BIOS, it has to be handled either 480 by the ACPI OSI, or by userspace. 481 The driver does the right thing, 482 never mess with this. 4830x1011 0x10 FN+END Brightness down. See brightness 484 up for details. 485 4860x1012 0x11 FN+PGUP ThinkLight toggle. This key is 487 always handled by the firmware, 488 even when unmasked. 489 4900x1013 0x12 FN+PGDOWN - 491 4920x1014 0x13 FN+SPACE Zoom key 493 4940x1015 0x14 VOLUME UP 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. 4990x1016 0x15 VOLUME DOWN Internal mixer volume up. This 500 key is always handled by the 501 firmware, even when unmasked. 502 NOTE: Lenovo seems to be changing 503 this. 5040x1017 0x16 MUTE Mute internal mixer. This 505 key is always handled by the 506 firmware, even when unmasked. 507 5080x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key 509 5100x1019 0x18 unknown 511 5120x131f ... FN+F8 Platform Mode change (2024 systems). 513 Implemented in driver. 514 5150x1401 ... FN+F8 Platform Mode change (2025 + systems). 516 Implemented in driver. 517... ... ... 518 5190x1020 0x1F unknown 520======= ======= ============== ============================================== 521 522The ThinkPad firmware does not allow one to differentiate when most hot 523keys are pressed or released (either that, or we don't know how to, yet). 524For these keys, the driver generates a set of events for a key press and 525immediately issues the same set of events for a key release. It is 526unknown by the driver if the ThinkPad firmware triggered these events on 527hot key press or release, but the firmware will do it for either one, not 528both. 529 530If a key is mapped to KEY_RESERVED, it generates no input events at all. 531If a key is mapped to KEY_UNKNOWN, it generates an input event that 532includes an scan code. If a key is mapped to anything else, it will 533generate input device EV_KEY events. 534 535In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW 536events for switches: 537 538============== ============================================== 539SW_RFKILL_ALL T60 and later hardware rfkill rocker switch 540SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A 541============== ============================================== 542 543Non hotkey ACPI HKEY event map 544------------------------------ 545 546Events that are never propagated by the driver: 547 548====== ================================================== 5490x2304 System is waking up from suspend to undock 5500x2305 System is waking up from suspend to eject bay 5510x2404 System is waking up from hibernation to undock 5520x2405 System is waking up from hibernation to eject bay 5530x5001 Lid closed 5540x5002 Lid opened 5550x5009 Tablet swivel: switched to tablet mode 5560x500A Tablet swivel: switched to normal mode 5570x5010 Brightness level changed/control event 5580x6000 KEYBOARD: Numlock key pressed 5590x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) 5600x7000 Radio Switch may have changed state 561====== ================================================== 562 563 564Events that are propagated by the driver to userspace: 565 566====== ===================================================== 5670x2313 ALARM: System is waking up from suspend because 568 the battery is nearly empty 5690x2413 ALARM: System is waking up from hibernation because 570 the battery is nearly empty 5710x3003 Bay ejection (see 0x2x05) complete, can sleep again 5720x3006 Bay hotplug request (hint to power up SATA link when 573 the optical drive tray is ejected) 5740x4003 Undocked (see 0x2x04), can sleep again 5750x4010 Docked into hotplug port replicator (non-ACPI dock) 5760x4011 Undocked from hotplug port replicator (non-ACPI dock) 5770x500B Tablet pen inserted into its storage bay 5780x500C Tablet pen removed from its storage bay 5790x6011 ALARM: battery is too hot 5800x6012 ALARM: battery is extremely hot 5810x6021 ALARM: a sensor is too hot 5820x6022 ALARM: a sensor is extremely hot 5830x6030 System thermal table changed 5840x6032 Thermal Control command set completion (DYTC, Windows) 5850x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) 5860x60C0 X1 Yoga 2016, Tablet mode status changed 5870x60F0 Thermal Transformation changed (GMTS, Windows) 588====== ===================================================== 589 590Battery nearly empty alarms are a last resort attempt to get the 591operating system to hibernate or shutdown cleanly (0x2313), or shutdown 592cleanly (0x2413) before power is lost. They must be acted upon, as the 593wake up caused by the firmware will have negated most safety nets... 594 595When any of the "too hot" alarms happen, according to Lenovo the user 596should suspend or hibernate the laptop (and in the case of battery 597alarms, unplug the AC adapter) to let it cool down. These alarms do 598signal that something is wrong, they should never happen on normal 599operating conditions. 600 601The "extremely hot" alarms are emergencies. According to Lenovo, the 602operating system is to force either an immediate suspend or hibernate 603cycle, or a system shutdown. Obviously, something is very wrong if this 604happens. 605 606 607Brightness hotkey notes 608^^^^^^^^^^^^^^^^^^^^^^^ 609 610Don't mess with the brightness hotkeys in a Thinkpad. If you want 611notifications for OSD, use the sysfs backlight class event support. 612 613The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events 614automatically for the cases were userspace has to do something to 615implement brightness changes. When you override these events, you will 616either fail to handle properly the ThinkPads that require explicit 617action to change backlight brightness, or the ThinkPads that require 618that no action be taken to work properly. 619 620 621Bluetooth 622--------- 623 624procfs: /proc/acpi/ibm/bluetooth 625 626sysfs device attribute: bluetooth_enable (deprecated) 627 628sysfs rfkill class: switch "tpacpi_bluetooth_sw" 629 630This feature shows the presence and current state of a ThinkPad 631Bluetooth device in the internal ThinkPad CDC slot. 632 633If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, 634so it is kept across reboots and power-off. 635 636Procfs notes 637^^^^^^^^^^^^ 638 639If Bluetooth is installed, the following commands can be used:: 640 641 echo enable > /proc/acpi/ibm/bluetooth 642 echo disable > /proc/acpi/ibm/bluetooth 643 644Sysfs notes 645^^^^^^^^^^^ 646 647 If the Bluetooth CDC card is installed, it can be enabled / 648 disabled through the "bluetooth_enable" thinkpad-acpi device 649 attribute, and its current status can also be queried. 650 651 enable: 652 653 - 0: disables Bluetooth / Bluetooth is disabled 654 - 1: enables Bluetooth / Bluetooth is enabled. 655 656 Note: this interface has been superseded by the generic rfkill 657 class. It has been deprecated, and it will be removed in year 658 2010. 659 660 rfkill controller switch "tpacpi_bluetooth_sw": refer to 661 Documentation/driver-api/rfkill.rst for details. 662 663 664Video output control -- /proc/acpi/ibm/video 665-------------------------------------------- 666 667This feature allows control over the devices used for video output - 668LCD, CRT or DVI (if available). The following commands are available:: 669 670 echo lcd_enable > /proc/acpi/ibm/video 671 echo lcd_disable > /proc/acpi/ibm/video 672 echo crt_enable > /proc/acpi/ibm/video 673 echo crt_disable > /proc/acpi/ibm/video 674 echo dvi_enable > /proc/acpi/ibm/video 675 echo dvi_disable > /proc/acpi/ibm/video 676 echo auto_enable > /proc/acpi/ibm/video 677 echo auto_disable > /proc/acpi/ibm/video 678 echo expand_toggle > /proc/acpi/ibm/video 679 echo video_switch > /proc/acpi/ibm/video 680 681NOTE: 682 Access to this feature is restricted to processes owning the 683 CAP_SYS_ADMIN capability for safety reasons, as it can interact badly 684 enough with some versions of X.org to crash it. 685 686Each video output device can be enabled or disabled individually. 687Reading /proc/acpi/ibm/video shows the status of each device. 688 689Automatic video switching can be enabled or disabled. When automatic 690video switching is enabled, certain events (e.g. opening the lid, 691docking or undocking) cause the video output device to change 692automatically. While this can be useful, it also causes flickering 693and, on the X40, video corruption. By disabling automatic switching, 694the flickering or video corruption can be avoided. 695 696The video_switch command cycles through the available video outputs 697(it simulates the behavior of Fn-F7). 698 699Video expansion can be toggled through this feature. This controls 700whether the display is expanded to fill the entire LCD screen when a 701mode with less than full resolution is used. Note that the current 702video expansion status cannot be determined through this feature. 703 704Note that on many models (particularly those using Radeon graphics 705chips) the X driver configures the video card in a way which prevents 706Fn-F7 from working. This also disables the video output switching 707features of this driver, as it uses the same ACPI methods as 708Fn-F7. Video switching on the console should still work. 709 710UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 711 712 713ThinkLight control 714------------------ 715 716procfs: /proc/acpi/ibm/light 717 718sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED 719 720procfs notes 721^^^^^^^^^^^^ 722 723The ThinkLight status can be read and set through the procfs interface. A 724few models which do not make the status available will show the ThinkLight 725status as "unknown". The available commands are:: 726 727 echo on > /proc/acpi/ibm/light 728 echo off > /proc/acpi/ibm/light 729 730sysfs notes 731^^^^^^^^^^^ 732 733The ThinkLight sysfs interface is documented by the LED class 734documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name 735is "tpacpi::thinklight". 736 737Due to limitations in the sysfs LED class, if the status of the ThinkLight 738cannot be read or if it is unknown, thinkpad-acpi will report it as "off". 739It is impossible to know if the status returned through sysfs is valid. 740 741 742CMOS/UCMS control 743----------------- 744 745procfs: /proc/acpi/ibm/cmos 746 747sysfs device attribute: cmos_command 748 749This feature is mostly used internally by the ACPI firmware to keep the legacy 750CMOS NVRAM bits in sync with the current machine state, and to record this 751state so that the ThinkPad will retain such settings across reboots. 752 753Some of these commands actually perform actions in some ThinkPad models, but 754this is expected to disappear more and more in newer models. As an example, in 755a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for 756real, but commands 0 to 2 don't control the mixer anymore (they have been 757phased out) and just update the NVRAM. 758 759The range of valid cmos command numbers is 0 to 21, but not all have an 760effect and the behavior varies from model to model. Here is the behavior 761on the X40 (tpb is the ThinkPad Buttons utility): 762 763 - 0 - Related to "Volume down" key press 764 - 1 - Related to "Volume up" key press 765 - 2 - Related to "Mute on" key press 766 - 3 - Related to "Access IBM" key press 767 - 4 - Related to "LCD brightness up" key press 768 - 5 - Related to "LCD brightness down" key press 769 - 11 - Related to "toggle screen expansion" key press/function 770 - 12 - Related to "ThinkLight on" 771 - 13 - Related to "ThinkLight off" 772 - 14 - Related to "ThinkLight" key press (toggle ThinkLight) 773 774The cmos command interface is prone to firmware split-brain problems, as 775in newer ThinkPads it is just a compatibility layer. Do not use it, it is 776exported just as a debug tool. 777 778 779LED control 780----------- 781 782procfs: /proc/acpi/ibm/led 783sysfs attributes: as per LED class, see below for names 784 785Some of the LED indicators can be controlled through this feature. On 786some older ThinkPad models, it is possible to query the status of the 787LED indicators as well. Newer ThinkPads cannot query the real status 788of the LED indicators. 789 790Because misuse of the LEDs could induce an unaware user to perform 791dangerous actions (like undocking or ejecting a bay device while the 792buses are still active), or mask an important alarm (such as a nearly 793empty battery, or a broken battery), access to most LEDs is 794restricted. 795 796Unrestricted access to all LEDs requires that thinkpad-acpi be 797compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. 798Distributions must never enable this option. Individual users that 799are aware of the consequences are welcome to enabling it. 800 801Audio mute and microphone mute LEDs are supported, but currently not 802visible to userspace. They are used by the snd-hda-intel audio driver. 803 804procfs notes 805^^^^^^^^^^^^ 806 807The available commands are:: 808 809 echo '<LED number> on' >/proc/acpi/ibm/led 810 echo '<LED number> off' >/proc/acpi/ibm/led 811 echo '<LED number> blink' >/proc/acpi/ibm/led 812 813The <LED number> range is 0 to 15. The set of LEDs that can be 814controlled varies from model to model. Here is the common ThinkPad 815mapping: 816 817 - 0 - power 818 - 1 - battery (orange) 819 - 2 - battery (green) 820 - 3 - UltraBase/dock 821 - 4 - UltraBay 822 - 5 - UltraBase battery slot 823 - 6 - (unknown) 824 - 7 - standby 825 - 8 - dock status 1 826 - 9 - dock status 2 827 - 10, 11 - (unknown) 828 - 12 - thinkvantage 829 - 13, 14, 15 - (unknown) 830 831All of the above can be turned on and off and can be made to blink. 832 833sysfs notes 834^^^^^^^^^^^ 835 836The ThinkPad LED sysfs interface is described in detail by the LED class 837documentation, in Documentation/leds/leds-class.rst. 838 839The LEDs are named (in LED ID order, from 0 to 12): 840"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", 841"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", 842"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", 843"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", 844"tpacpi::thinkvantage". 845 846Due to limitations in the sysfs LED class, if the status of the LED 847indicators cannot be read due to an error, thinkpad-acpi will report it as 848a brightness of zero (same as LED off). 849 850If the thinkpad firmware doesn't support reading the current status, 851trying to read the current LED brightness will just return whatever 852brightness was last written to that attribute. 853 854These LEDs can blink using hardware acceleration. To request that a 855ThinkPad indicator LED should blink in hardware accelerated mode, use the 856"timer" trigger, and leave the delay_on and delay_off parameters set to 857zero (to request hardware acceleration autodetection). 858 859LEDs that are known not to exist in a given ThinkPad model are not 860made available through the sysfs interface. If you have a dock and you 861notice there are LEDs listed for your ThinkPad that do not exist (and 862are not in the dock), or if you notice that there are missing LEDs, 863a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. 864 865 866ACPI sounds -- /proc/acpi/ibm/beep 867---------------------------------- 868 869The BEEP method is used internally by the ACPI firmware to provide 870audible alerts in various situations. This feature allows the same 871sounds to be triggered manually. 872 873The commands are non-negative integer numbers:: 874 875 echo <number> >/proc/acpi/ibm/beep 876 877The valid <number> range is 0 to 17. Not all numbers trigger sounds 878and the sounds vary from model to model. Here is the behavior on the 879X40: 880 881 - 0 - stop a sound in progress (but use 17 to stop 16) 882 - 2 - two beeps, pause, third beep ("low battery") 883 - 3 - single beep 884 - 4 - high, followed by low-pitched beep ("unable") 885 - 5 - single beep 886 - 6 - very high, followed by high-pitched beep ("AC/DC") 887 - 7 - high-pitched beep 888 - 9 - three short beeps 889 - 10 - very long beep 890 - 12 - low-pitched beep 891 - 15 - three high-pitched beeps repeating constantly, stop with 0 892 - 16 - one medium-pitched beep repeating constantly, stop with 17 893 - 17 - stop 16 894 895 896Temperature sensors 897------------------- 898 899procfs: /proc/acpi/ibm/thermal 900 901sysfs device attributes: (hwmon "thinkpad") temp*_input 902 903Most ThinkPads include six or more separate temperature sensors but only 904expose the CPU temperature through the standard ACPI methods. This 905feature shows readings from up to eight different sensors on older 906ThinkPads, and up to sixteen different sensors on newer ThinkPads. 907 908For example, on the X40, a typical output may be: 909 910temperatures: 911 42 42 45 41 36 -128 33 -128 912 913On the T43/p, a typical output may be: 914 915temperatures: 916 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 917 918The mapping of thermal sensors to physical locations varies depending on 919system-board model (and thus, on ThinkPad model). 920 921https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that 922tries to track down these locations for various models. 923 924Most (newer?) models seem to follow this pattern: 925 926- 1: CPU 927- 2: (depends on model) 928- 3: (depends on model) 929- 4: GPU 930- 5: Main battery: main sensor 931- 6: Bay battery: main sensor 932- 7: Main battery: secondary sensor 933- 8: Bay battery: secondary sensor 934- 9-15: (depends on model) 935 936For the R51 (source: Thomas Gruber): 937 938- 2: Mini-PCI 939- 3: Internal HDD 940 941For the T43, T43/p (source: Shmidoax/Thinkwiki.org) 942https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p 943 944- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp 945- 3: PCMCIA slot 946- 9: MCH (northbridge) to DRAM Bus 947- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI 948 card, under touchpad 949- 11: Power regulator, underside of system board, below F2 key 950 951The A31 has a very atypical layout for the thermal sensors 952(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) 953 954- 1: CPU 955- 2: Main Battery: main sensor 956- 3: Power Converter 957- 4: Bay Battery: main sensor 958- 5: MCH (northbridge) 959- 6: PCMCIA/ambient 960- 7: Main Battery: secondary sensor 961- 8: Bay Battery: secondary sensor 962 963 964Procfs notes 965^^^^^^^^^^^^ 966 967 Readings from sensors that are not available return -128. 968 No commands can be written to this file. 969 970Sysfs notes 971^^^^^^^^^^^ 972 973 Sensors that are not available return the ENXIO error. This 974 status may change at runtime, as there are hotplug thermal 975 sensors, like those inside the batteries and docks. 976 977 thinkpad-acpi thermal sensors are reported through the hwmon 978 subsystem, and follow all of the hwmon guidelines at 979 Documentation/hwmon. 980 981EXPERIMENTAL: Embedded controller register dump 982----------------------------------------------- 983 984This feature is not included in the thinkpad driver anymore. 985Instead the EC can be accessed through /sys/kernel/debug/ec with 986a userspace tool which can be found here: 987ftp://ftp.suse.com/pub/people/trenn/sources/ec 988 989Use it to determine the register holding the fan 990speed on some models. To do that, do the following: 991 992 - make sure the battery is fully charged 993 - make sure the fan is running 994 - use above mentioned tool to read out the EC 995 996Often fan and temperature values vary between 997readings. Since temperatures don't change vary fast, you can take 998several quick dumps to eliminate them. 999 1000You can use a similar method to figure out the meaning of other 1001embedded controller registers - e.g. make sure nothing else changes 1002except the charging or discharging battery to determine which 1003registers contain the current battery capacity, etc. If you experiment 1004with this, do send me your results (including some complete dumps with 1005a description of the conditions when they were taken.) 1006 1007 1008LCD brightness control 1009---------------------- 1010 1011procfs: /proc/acpi/ibm/brightness 1012 1013sysfs backlight device "thinkpad_screen" 1014 1015This feature allows software control of the LCD brightness on ThinkPad 1016models which don't have a hardware brightness slider. 1017 1018It has some limitations: the LCD backlight cannot be actually turned 1019on or off by this interface, it just controls the backlight brightness 1020level. 1021 1022On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control 1023has eight brightness levels, ranging from 0 to 7. Some of the levels 1024may not be distinct. Later Lenovo models that implement the ACPI 1025display backlight brightness control methods have 16 levels, ranging 1026from 0 to 15. 1027 1028For IBM ThinkPads, there are two interfaces to the firmware for direct 1029brightness control, EC and UCMS (or CMOS). To select which one should be 1030used, use the brightness_mode module parameter: brightness_mode=1 selects 1031EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC 1032mode with NVRAM backing (so that brightness changes are remembered across 1033shutdown/reboot). 1034 1035The driver tries to select which interface to use from a table of 1036defaults for each ThinkPad model. If it makes a wrong choice, please 1037report this as a bug, so that we can fix it. 1038 1039Lenovo ThinkPads only support brightness_mode=2 (UCMS). 1040 1041When display backlight brightness controls are available through the 1042standard ACPI interface, it is best to use it instead of this direct 1043ThinkPad-specific interface. The driver will disable its native 1044backlight brightness control interface if it detects that the standard 1045ACPI interface is available in the ThinkPad. 1046 1047If you want to use the thinkpad-acpi backlight brightness control 1048instead of the generic ACPI video backlight brightness control for some 1049reason, you should use the acpi_backlight=vendor kernel parameter. 1050 1051The brightness_enable module parameter can be used to control whether 1052the LCD brightness control feature will be enabled when available. 1053brightness_enable=0 forces it to be disabled. brightness_enable=1 1054forces it to be enabled when available, even if the standard ACPI 1055interface is also available. 1056 1057Procfs notes 1058^^^^^^^^^^^^ 1059 1060The available commands are:: 1061 1062 echo up >/proc/acpi/ibm/brightness 1063 echo down >/proc/acpi/ibm/brightness 1064 echo 'level <level>' >/proc/acpi/ibm/brightness 1065 1066Sysfs notes 1067^^^^^^^^^^^ 1068 1069The interface is implemented through the backlight sysfs class, which is 1070poorly documented at this time. 1071 1072Locate the thinkpad_screen device under /sys/class/backlight, and inside 1073it there will be the following attributes: 1074 1075 max_brightness: 1076 Reads the maximum brightness the hardware can be set to. 1077 The minimum is always zero. 1078 1079 actual_brightness: 1080 Reads what brightness the screen is set to at this instant. 1081 1082 brightness: 1083 Writes request the driver to change brightness to the 1084 given value. Reads will tell you what brightness the 1085 driver is trying to set the display to when "power" is set 1086 to zero and the display has not been dimmed by a kernel 1087 power management event. 1088 1089 power: 1090 power management mode, where 0 is "display on", and 1 to 3 1091 will dim the display backlight to brightness level 0 1092 because thinkpad-acpi cannot really turn the backlight 1093 off. Kernel power management events can temporarily 1094 increase the current power management level, i.e. they can 1095 dim the display. 1096 1097 1098WARNING: 1099 1100 Whatever you do, do NOT ever call thinkpad-acpi backlight-level change 1101 interface and the ACPI-based backlight level change interface 1102 (available on newer BIOSes, and driven by the Linux ACPI video driver) 1103 at the same time. The two will interact in bad ways, do funny things, 1104 and maybe reduce the life of the backlight lamps by needlessly kicking 1105 its level up and down at every change. 1106 1107 1108Volume control (Console Audio control) 1109-------------------------------------- 1110 1111procfs: /proc/acpi/ibm/volume 1112 1113ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" 1114 1115NOTE: by default, the volume control interface operates in read-only 1116mode, as it is supposed to be used for on-screen-display purposes. 1117The read/write mode can be enabled through the use of the 1118"volume_control=1" module parameter. 1119 1120NOTE: distros are urged to not enable volume_control by default, this 1121should be done by the local admin only. The ThinkPad UI is for the 1122console audio control to be done through the volume keys only, and for 1123the desktop environment to just provide on-screen-display feedback. 1124Software volume control should be done only in the main AC97/HDA 1125mixer. 1126 1127 1128About the ThinkPad Console Audio control 1129^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1130 1131ThinkPads have a built-in amplifier and muting circuit that drives the 1132console headphone and speakers. This circuit is after the main AC97 1133or HDA mixer in the audio path, and under exclusive control of the 1134firmware. 1135 1136ThinkPads have three special hotkeys to interact with the console 1137audio control: volume up, volume down and mute. 1138 1139It is worth noting that the normal way the mute function works (on 1140ThinkPads that do not have a "mute LED") is: 1141 11421. Press mute to mute. It will *always* mute, you can press it as 1143 many times as you want, and the sound will remain mute. 1144 11452. Press either volume key to unmute the ThinkPad (it will _not_ 1146 change the volume, it will just unmute). 1147 1148This is a very superior design when compared to the cheap software-only 1149mute-toggle solution found on normal consumer laptops: you can be 1150absolutely sure the ThinkPad will not make noise if you press the mute 1151button, no matter the previous state. 1152 1153The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain 1154amplifiers driving the speakers and headphone output, and the firmware 1155also handles volume control for the headphone and speakers on these 1156ThinkPads without any help from the operating system (this volume 1157control stage exists after the main AC97 or HDA mixer in the audio 1158path). 1159 1160The newer Lenovo models only have firmware mute control, and depend on 1161the main HDA mixer to do volume control (which is done by the operating 1162system). In this case, the volume keys are filtered out for unmute 1163key press (there are some firmware bugs in this area) and delivered as 1164normal key presses to the operating system (thinkpad-acpi is not 1165involved). 1166 1167 1168The ThinkPad-ACPI volume control 1169^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1170 1171The preferred way to interact with the Console Audio control is the 1172ALSA interface. 1173 1174The legacy procfs interface allows one to read the current state, 1175and if volume control is enabled, accepts the following commands:: 1176 1177 echo up >/proc/acpi/ibm/volume 1178 echo down >/proc/acpi/ibm/volume 1179 echo mute >/proc/acpi/ibm/volume 1180 echo unmute >/proc/acpi/ibm/volume 1181 echo 'level <level>' >/proc/acpi/ibm/volume 1182 1183The <level> number range is 0 to 14 although not all of them may be 1184distinct. To unmute the volume after the mute command, use either the 1185up or down command (the level command will not unmute the volume), or 1186the unmute command. 1187 1188You can use the volume_capabilities parameter to tell the driver 1189whether your thinkpad has volume control or mute-only control: 1190volume_capabilities=1 for mixers with mute and volume control, 1191volume_capabilities=2 for mixers with only mute control. 1192 1193If the driver misdetects the capabilities for your ThinkPad model, 1194please report this to ibm-acpi-devel@lists.sourceforge.net, so that we 1195can update the driver. 1196 1197There are two strategies for volume control. To select which one 1198should be used, use the volume_mode module parameter: volume_mode=1 1199selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing 1200(so that volume/mute changes are remembered across shutdown/reboot). 1201 1202The driver will operate in volume_mode=3 by default. If that does not 1203work well on your ThinkPad model, please report this to 1204ibm-acpi-devel@lists.sourceforge.net. 1205 1206The driver supports the standard ALSA module parameters. If the ALSA 1207mixer is disabled, the driver will disable all volume functionality. 1208 1209 1210Fan control and monitoring: fan speed, fan enable/disable 1211--------------------------------------------------------- 1212 1213procfs: /proc/acpi/ibm/fan 1214 1215sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input 1216 1217sysfs hwmon driver attributes: fan_watchdog 1218 1219NOTE NOTE NOTE: 1220 fan control operations are disabled by default for 1221 safety reasons. To enable them, the module parameter "fan_control=1" 1222 must be given to thinkpad-acpi. 1223 1224This feature attempts to show the current fan speed, control mode and 1225other fan data that might be available. The speed is read directly 1226from the hardware registers of the embedded controller. This is known 1227to work on later R, T, X and Z series ThinkPads but may show a bogus 1228value on other models. 1229 1230Some Lenovo ThinkPads support a secondary fan. This fan cannot be 1231controlled separately, it shares the main fan control. 1232 1233Fan levels 1234^^^^^^^^^^ 1235 1236Most ThinkPad fans work in "levels" at the firmware interface. Level 0 1237stops the fan. The higher the level, the higher the fan speed, although 1238adjacent levels often map to the same fan speed. 7 is the highest 1239level, where the fan reaches the maximum recommended speed. 1240 1241Level "auto" means the EC changes the fan level according to some 1242internal algorithm, usually based on readings from the thermal sensors. 1243 1244There is also a "full-speed" level, also known as "disengaged" level. 1245In this level, the EC disables the speed-locked closed-loop fan control, 1246and drives the fan as fast as it can go, which might exceed hardware 1247limits, so use this level with caution. 1248 1249The fan usually ramps up or down slowly from one speed to another, and 1250it is normal for the EC to take several seconds to react to fan 1251commands. The full-speed level may take up to two minutes to ramp up to 1252maximum speed, and in some ThinkPads, the tachometer readings go stale 1253while the EC is transitioning to the full-speed level. 1254 1255WARNING WARNING WARNING: do not leave the fan disabled unless you are 1256monitoring all of the temperature sensor readings and you are ready to 1257enable it if necessary to avoid overheating. 1258 1259An enabled fan in level "auto" may stop spinning if the EC decides the 1260ThinkPad is cool enough and doesn't need the extra airflow. This is 1261normal, and the EC will spin the fan up if the various thermal readings 1262rise too much. 1263 1264On the X40, this seems to depend on the CPU and HDD temperatures. 1265Specifically, the fan is turned on when either the CPU temperature 1266climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The 1267fan is turned off when the CPU temperature drops to 49 degrees and the 1268HDD temperature drops to 41 degrees. These thresholds cannot 1269currently be controlled. 1270 1271The ThinkPad's ACPI DSDT code will reprogram the fan on its own when 1272certain conditions are met. It will override any fan programming done 1273through thinkpad-acpi. 1274 1275The thinkpad-acpi kernel driver can be programmed to revert the fan 1276level to a safe setting if userspace does not issue one of the procfs 1277fan commands: "enable", "disable", "level" or "watchdog", or if there 1278are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is 1279set to 1, manual mode) within a configurable amount of time of up to 1280120 seconds. This functionality is called fan safety watchdog. 1281 1282Note that the watchdog timer stops after it enables the fan. It will be 1283rearmed again automatically (using the same interval) when one of the 1284above mentioned fan commands is received. The fan watchdog is, 1285therefore, not suitable to protect against fan mode changes made through 1286means other than the "enable", "disable", and "level" procfs fan 1287commands, or the hwmon fan control sysfs interface. 1288 1289Procfs notes 1290^^^^^^^^^^^^ 1291 1292The fan may be enabled or disabled with the following commands:: 1293 1294 echo enable >/proc/acpi/ibm/fan 1295 echo disable >/proc/acpi/ibm/fan 1296 1297Placing a fan on level 0 is the same as disabling it. Enabling a fan 1298will try to place it in a safe level if it is too slow or disabled. 1299 1300The fan level can be controlled with the command:: 1301 1302 echo 'level <level>' > /proc/acpi/ibm/fan 1303 1304Where <level> is an integer from 0 to 7, or one of the words "auto" or 1305"full-speed" (without the quotes). Not all ThinkPads support the "auto" 1306and "full-speed" levels. The driver accepts "disengaged" as an alias for 1307"full-speed", and reports it as "disengaged" for backwards 1308compatibility. 1309 1310On the X31 and X40 (and ONLY on those models), the fan speed can be 1311controlled to a certain degree. Once the fan is running, it can be 1312forced to run faster or slower with the following command:: 1313 1314 echo 'speed <speed>' > /proc/acpi/ibm/fan 1315 1316The sustainable range of fan speeds on the X40 appears to be from about 13173700 to about 7350. Values outside this range either do not have any 1318effect or the fan speed eventually settles somewhere in that range. The 1319fan cannot be stopped or started with this command. This functionality 1320is incomplete, and not available through the sysfs interface. 1321 1322To program the safety watchdog, use the "watchdog" command:: 1323 1324 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan 1325 1326If you want to disable the watchdog, use 0 as the interval. 1327 1328Sysfs notes 1329^^^^^^^^^^^ 1330 1331The sysfs interface follows the hwmon subsystem guidelines for the most 1332part, and the exception is the fan safety watchdog. 1333 1334Writes to any of the sysfs attributes may return the EINVAL error if 1335that operation is not supported in a given ThinkPad or if the parameter 1336is out-of-bounds, and EPERM if it is forbidden. They may also return 1337EINTR (interrupted system call), and EIO (I/O error while trying to talk 1338to the firmware). 1339 1340Features not yet implemented by the driver return ENOSYS. 1341 1342hwmon device attribute pwm1_enable: 1343 - 0: PWM offline (fan is set to full-speed mode) 1344 - 1: Manual PWM control (use pwm1 to set fan level) 1345 - 2: Hardware PWM control (EC "auto" mode) 1346 - 3: reserved (Software PWM control, not implemented yet) 1347 1348 Modes 0 and 2 are not supported by all ThinkPads, and the 1349 driver is not always able to detect this. If it does know a 1350 mode is unsupported, it will return -EINVAL. 1351 1352hwmon device attribute pwm1: 1353 Fan level, scaled from the firmware values of 0-7 to the hwmon 1354 scale of 0-255. 0 means fan stopped, 255 means highest normal 1355 speed (level 7). 1356 1357 This attribute only commands the fan if pmw1_enable is set to 1 1358 (manual PWM control). 1359 1360hwmon device attribute fan1_input: 1361 Fan tachometer reading, in RPM. May go stale on certain 1362 ThinkPads while the EC transitions the PWM to offline mode, 1363 which can take up to two minutes. May return rubbish on older 1364 ThinkPads. 1365 1366hwmon device attribute fan2_input: 1367 Fan tachometer reading, in RPM, for the secondary fan. 1368 Available only on some ThinkPads. If the secondary fan is 1369 not installed, will always read 0. 1370 1371hwmon driver attribute fan_watchdog: 1372 Fan safety watchdog timer interval, in seconds. Minimum is 1373 1 second, maximum is 120 seconds. 0 disables the watchdog. 1374 1375To stop the fan: set pwm1 to zero, and pwm1_enable to 1. 1376 1377To start the fan in a safe mode: set pwm1_enable to 2. If that fails 1378with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255 1379would be the safest choice, though). 1380 1381 1382WAN 1383--- 1384 1385procfs: /proc/acpi/ibm/wan 1386 1387sysfs device attribute: wwan_enable (deprecated) 1388 1389sysfs rfkill class: switch "tpacpi_wwan_sw" 1390 1391This feature shows the presence and current state of the built-in 1392Wireless WAN device. 1393 1394If the ThinkPad supports it, the WWAN state is stored in NVRAM, 1395so it is kept across reboots and power-off. 1396 1397It was tested on a Lenovo ThinkPad X60. It should probably work on other 1398ThinkPad models which come with this module installed. 1399 1400Procfs notes 1401^^^^^^^^^^^^ 1402 1403If the W-WAN card is installed, the following commands can be used:: 1404 1405 echo enable > /proc/acpi/ibm/wan 1406 echo disable > /proc/acpi/ibm/wan 1407 1408Sysfs notes 1409^^^^^^^^^^^ 1410 1411 If the W-WAN card is installed, it can be enabled / 1412 disabled through the "wwan_enable" thinkpad-acpi device 1413 attribute, and its current status can also be queried. 1414 1415 enable: 1416 - 0: disables WWAN card / WWAN card is disabled 1417 - 1: enables WWAN card / WWAN card is enabled. 1418 1419 Note: this interface has been superseded by the generic rfkill 1420 class. It has been deprecated, and it will be removed in year 1421 2010. 1422 1423 rfkill controller switch "tpacpi_wwan_sw": refer to 1424 Documentation/driver-api/rfkill.rst for details. 1425 1426 1427LCD Shadow control 1428------------------ 1429 1430procfs: /proc/acpi/ibm/lcdshadow 1431 1432Some newer T480s and T490s ThinkPads provide a feature called 1433PrivacyGuard. By turning this feature on, the usable vertical and 1434horizontal viewing angles of the LCD can be limited (as if some privacy 1435screen was applied manually in front of the display). 1436 1437procfs notes 1438^^^^^^^^^^^^ 1439 1440The available commands are:: 1441 1442 echo '0' >/proc/acpi/ibm/lcdshadow 1443 echo '1' >/proc/acpi/ibm/lcdshadow 1444 1445The first command ensures the best viewing angle and the latter one turns 1446on the feature, restricting the viewing angles. 1447 1448 1449DYTC Lapmode sensor 1450------------------- 1451 1452sysfs: dytc_lapmode 1453 1454Newer thinkpads and mobile workstations have the ability to determine if 1455the device is in deskmode or lapmode. This feature is used by user space 1456to decide if WWAN transmission can be increased to maximum power and is 1457also useful for understanding the different thermal modes available as 1458they differ between desk and lap mode. 1459 1460The property is read-only. If the platform doesn't have support the sysfs 1461class is not created. 1462 1463EXPERIMENTAL: UWB 1464----------------- 1465 1466This feature is considered EXPERIMENTAL because it has not been extensively 1467tested and validated in various ThinkPad models yet. The feature may not 1468work as expected. USE WITH CAUTION! To use this feature, you need to supply 1469the experimental=1 parameter when loading the module. 1470 1471sysfs rfkill class: switch "tpacpi_uwb_sw" 1472 1473This feature exports an rfkill controller for the UWB device, if one is 1474present and enabled in the BIOS. 1475 1476Sysfs notes 1477^^^^^^^^^^^ 1478 1479 rfkill controller switch "tpacpi_uwb_sw": refer to 1480 Documentation/driver-api/rfkill.rst for details. 1481 1482 1483Setting keyboard language 1484------------------------- 1485 1486sysfs: keyboard_lang 1487 1488This feature is used to set keyboard language to ECFW using ASL interface. 1489Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(', 1490")" numeric keys, which are not displaying correctly, when keyboard language 1491is other than "english". This is because the default keyboard language in ECFW 1492is set as "english". Hence using this sysfs, user can set the correct keyboard 1493language to ECFW and then these key's will work correctly. 1494 1495Example of command to set keyboard language is mentioned below:: 1496 1497 echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang 1498 1499Text corresponding to keyboard layout to be set in sysfs are: be(Belgian), 1500cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian), 1501fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan), 1502nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden), 1503tr(Turkey) 1504 1505WWAN Antenna type 1506----------------- 1507 1508sysfs: wwan_antenna_type 1509 1510On some newer Thinkpads we need to set SAR value based on the antenna 1511type. This interface will be used by userspace to get the antenna type 1512and set the corresponding SAR value, as is required for FCC certification. 1513 1514The available commands are:: 1515 1516 cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type 1517 1518Currently 2 antenna types are supported as mentioned below: 1519- type a 1520- type b 1521 1522The property is read-only. If the platform doesn't have support the sysfs 1523class is not created. 1524 1525Auxmac 1526------ 1527 1528sysfs: auxmac 1529 1530Some newer Thinkpads have a feature called MAC Address Pass-through. This 1531feature is implemented by the system firmware to provide a system unique MAC, 1532that can override a dock or USB ethernet dongle MAC, when connected to a 1533network. This property enables user-space to easily determine the MAC address 1534if the feature is enabled. 1535 1536The values of this auxiliary MAC are: 1537 1538 cat /sys/devices/platform/thinkpad_acpi/auxmac 1539 1540If the feature is disabled, the value will be 'disabled'. 1541 1542This property is read-only. 1543 1544Adaptive keyboard 1545----------------- 1546 1547sysfs device attribute: adaptive_kbd_mode 1548 1549This sysfs attribute controls the keyboard "face" that will be shown on the 1550Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read 1551and set. 1552 1553- 0 = Home mode 1554- 1 = Web-browser mode 1555- 2 = Web-conference mode 1556- 3 = Function mode 1557- 4 = Layflat mode 1558 1559For more details about which buttons will appear depending on the mode, please 1560review the laptop's user guide: 1561https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf 1562 1563Battery charge control 1564---------------------- 1565 1566sysfs attributes: 1567/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold 1568 1569These two attributes are created for those batteries that are supported by the 1570driver. They enable the user to control the battery charge thresholds of the 1571given battery. Both values may be read and set. `charge_control_start_threshold` 1572accepts an integer between 0 and 99 (inclusive); this value represents a battery 1573percentage level, below which charging will begin. `charge_control_end_threshold` 1574accepts an integer between 1 and 100 (inclusive); this value represents a battery 1575percentage level, above which charging will stop. 1576 1577The exact semantics of the attributes may be found in 1578Documentation/ABI/testing/sysfs-class-power. 1579 1580Hardware damage detection capability 1581------------------------------------ 1582 1583sysfs attributes: hwdd_status, hwdd_detail 1584 1585Thinkpads are adding the ability to detect and report hardware damage. 1586Add new sysfs interface to identify the damaged device status. 1587Initial support is available for the USB-C replaceable connector. 1588 1589The command to check device damaged status is:: 1590 1591 cat /sys/devices/platform/thinkpad_acpi/hwdd_status 1592 1593This value displays status of device damaged. 1594 1595- 0 = Not Damaged 1596- 1 = Damaged 1597 1598The command to check location of damaged device is:: 1599 1600 cat /sys/devices/platform/thinkpad_acpi/hwdd_detail 1601 1602This value displays location of damaged device having 1 line per damaged "item". 1603For example: 1604 1605if no damage is detected: 1606 1607- No damage detected 1608 1609if damage detected: 1610 1611- TYPE-C: Base, Right side, Center port 1612 1613The property is read-only. If feature is not supported then sysfs 1614attribute is not created. 1615 1616Multiple Commands, Module Parameters 1617------------------------------------ 1618 1619Multiple commands can be written to the proc files in one shot by 1620separating them with commas, for example:: 1621 1622 echo enable,0xffff > /proc/acpi/ibm/hotkey 1623 echo lcd_disable,crt_enable > /proc/acpi/ibm/video 1624 1625Commands can also be specified when loading the thinkpad-acpi module, 1626for example:: 1627 1628 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable 1629 1630 1631Enabling debugging output 1632------------------------- 1633 1634The module takes a debug parameter which can be used to selectively 1635enable various classes of debugging output, for example:: 1636 1637 modprobe thinkpad_acpi debug=0xffff 1638 1639will enable all debugging output classes. It takes a bitmask, so 1640to enable more than one output class, just add their values. 1641 1642 ============= ====================================== 1643 Debug bitmask Description 1644 ============= ====================================== 1645 0x8000 Disclose PID of userspace programs 1646 accessing some functions of the driver 1647 0x0001 Initialization and probing 1648 0x0002 Removal 1649 0x0004 RF Transmitter control (RFKILL) 1650 (bluetooth, WWAN, UWB...) 1651 0x0008 HKEY event interface, hotkeys 1652 0x0010 Fan control 1653 0x0020 Backlight brightness 1654 0x0040 Audio mixer/volume control 1655 ============= ====================================== 1656 1657There is also a kernel build option to enable more debugging 1658information, which may be necessary to debug driver problems. 1659 1660The level of debugging information output by the driver can be changed 1661at runtime through sysfs, using the driver attribute debug_level. The 1662attribute takes the same bitmask as the debug module parameter above. 1663 1664 1665Force loading of module 1666----------------------- 1667 1668If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify 1669the module parameter force_load=1. Regardless of whether this works or 1670not, please contact ibm-acpi-devel@lists.sourceforge.net with a report. 1671 1672 1673Sysfs interface changelog 1674^^^^^^^^^^^^^^^^^^^^^^^^^ 1675 1676========= =============================================================== 16770x000100: Initial sysfs support, as a single platform driver and 1678 device. 16790x000200: Hot key support for 32 hot keys, and radio slider switch 1680 support. 16810x010000: Hot keys are now handled by default over the input 1682 layer, the radio switch generates input event EV_RADIO, 1683 and the driver enables hot key handling by default in 1684 the firmware. 1685 16860x020000: ABI fix: added a separate hwmon platform device and 1687 driver, which must be located by name (thinkpad) 1688 and the hwmon class for libsensors4 (lm-sensors 3) 1689 compatibility. Moved all hwmon attributes to this 1690 new platform device. 1691 16920x020100: Marker for thinkpad-acpi with hot key NVRAM polling 1693 support. If you must, use it to know you should not 1694 start a userspace NVRAM poller (allows to detect when 1695 NVRAM is compiled out by the user because it is 1696 unneeded/undesired in the first place). 16970x020101: Marker for thinkpad-acpi with hot key NVRAM polling 1698 and proper hotkey_mask semantics (version 8 of the 1699 NVRAM polling patch). Some development snapshots of 1700 0.18 had an earlier version that did strange things 1701 to hotkey_mask. 1702 17030x020200: Add poll()/select() support to the following attributes: 1704 hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason 1705 17060x020300: hotkey enable/disable support removed, attributes 1707 hotkey_bios_enabled and hotkey_enable deprecated and 1708 marked for removal. 1709 17100x020400: Marker for 16 LEDs support. Also, LEDs that are known 1711 to not exist in a given model are not registered with 1712 the LED sysfs class anymore. 1713 17140x020500: Updated hotkey driver, hotkey_mask is always available 1715 and it is always able to disable hot keys. Very old 1716 thinkpads are properly supported. hotkey_bios_mask 1717 is deprecated and marked for removal. 1718 17190x020600: Marker for backlight change event support. 1720 17210x020700: Support for mute-only mixers. 1722 Volume control in read-only mode by default. 1723 Marker for ALSA mixer support. 1724 17250x030000: Thermal and fan sysfs attributes were moved to the hwmon 1726 device instead of being attached to the backing platform 1727 device. 1728========= =============================================================== 1729