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diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst new file mode 100644 index 0000000000..e27a1c3f63 --- /dev/null +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -0,0 +1,1662 @@ +=========================== +ThinkPad ACPI Extras Driver +=========================== + +Version 0.25 + +October 16th, 2013 + +- Borislav Deianov <borislav@users.sf.net> +- Henrique de Moraes Holschuh <hmh@hmh.eng.br> + +http://ibm-acpi.sf.net/ + +This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It +supports various features of these laptops which are accessible +through the ACPI and ACPI EC framework, but not otherwise fully +supported by the generic Linux ACPI drivers. + +This driver used to be named ibm-acpi until kernel 2.6.21 and release +0.13-20070314. It used to be in the drivers/acpi tree, but it was +moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel +2.6.22, and release 0.14. It was moved to drivers/platform/x86 for +kernel 2.6.29 and release 0.22. + +The driver is named "thinkpad-acpi". In some places, like module +names and log messages, "thinkpad_acpi" is used because of userspace +issues. + +"tpacpi" is used as a shorthand where "thinkpad-acpi" would be too +long due to length limitations on some Linux kernel versions. + +Status +------ + +The features currently supported are the following (see below for +detailed description): + + - Fn key combinations + - Bluetooth enable and disable + - video output switching, expansion control + - ThinkLight on and off + - CMOS/UCMS control + - LED control + - ACPI sounds + - temperature sensors + - Experimental: embedded controller register dump + - LCD brightness control + - Volume control + - Fan control and monitoring: fan speed, fan enable/disable + - WAN enable and disable + - UWB enable and disable + - LCD Shadow (PrivacyGuard) enable and disable + - Lap mode sensor + - Setting keyboard language + - WWAN Antenna type + +A compatibility table by model and feature is maintained on the web +site, http://ibm-acpi.sf.net/. I appreciate any success or failure +reports, especially if they add to or correct the compatibility table. +Please include the following information in your report: + + - ThinkPad model name + - a copy of your ACPI tables, using the "acpidump" utility + - a copy of the output of dmidecode, with serial numbers + and UUIDs masked off + - which driver features work and which don't + - the observed behavior of non-working features + +Any other comments or patches are also more than welcome. + + +Installation +------------ + +If you are compiling this driver as included in the Linux kernel +sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. +It is located on the menu path: "Device Drivers" -> "X86 Platform +Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". + + +Features +-------- + +The driver exports two different interfaces to userspace, which can be +used to access the features it provides. One is a legacy procfs-based +interface, which will be removed at some time in the future. The other +is a new sysfs-based interface which is not complete yet. + +The procfs interface creates the /proc/acpi/ibm directory. There is a +file under that directory for each feature it supports. The procfs +interface is mostly frozen, and will change very little if at all: it +will not be extended to add any new functionality in the driver, instead +all new functionality will be implemented on the sysfs interface. + +The sysfs interface tries to blend in the generic Linux sysfs subsystems +and classes as much as possible. Since some of these subsystems are not +yet ready or stabilized, it is expected that this interface will change, +and any and all userspace programs must deal with it. + + +Notes about the sysfs interface +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Unlike what was done with the procfs interface, correctness when talking +to the sysfs interfaces will be enforced, as will correctness in the +thinkpad-acpi's implementation of sysfs interfaces. + +Also, any bugs in the thinkpad-acpi sysfs driver code or in the +thinkpad-acpi's implementation of the sysfs interfaces will be fixed for +maximum correctness, even if that means changing an interface in +non-compatible ways. As these interfaces mature both in the kernel and +in thinkpad-acpi, such changes should become quite rare. + +Applications interfacing to the thinkpad-acpi sysfs interfaces must +follow all sysfs guidelines and correctly process all errors (the sysfs +interface makes extensive use of errors). File descriptors and open / +close operations to the sysfs inodes must also be properly implemented. + +The version of thinkpad-acpi's sysfs interface is exported by the driver +as a driver attribute (see below). + +Sysfs driver attributes are on the driver's sysfs attribute space, +for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and +/sys/bus/platform/drivers/thinkpad_hwmon/ + +Sysfs device attributes are on the thinkpad_acpi device sysfs attribute +space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. + +Sysfs device attributes for the sensors and fan are on the +thinkpad_hwmon device's sysfs attribute space, but you should locate it +looking for a hwmon device with the name attribute of "thinkpad", or +better yet, through libsensors. For 4.14+ sysfs attributes were moved to the +hwmon device (/sys/bus/platform/devices/thinkpad_hwmon/hwmon/hwmon? or +/sys/class/hwmon/hwmon?). + +Driver version +-------------- + +procfs: /proc/acpi/ibm/driver + +sysfs driver attribute: version + +The driver name and version. No commands can be written to this file. + + +Sysfs interface version +----------------------- + +sysfs driver attribute: interface_version + +Version of the thinkpad-acpi sysfs interface, as an unsigned long +(output in hex format: 0xAAAABBCC), where: + + AAAA + - major revision + BB + - minor revision + CC + - bugfix revision + +The sysfs interface version changelog for the driver can be found at the +end of this document. Changes to the sysfs interface done by the kernel +subsystems are not documented here, nor are they tracked by this +attribute. + +Changes to the thinkpad-acpi sysfs interface are only considered +non-experimental when they are submitted to Linux mainline, at which +point the changes in this interface are documented and interface_version +may be updated. If you are using any thinkpad-acpi features not yet +sent to mainline for merging, you do so on your own risk: these features +may disappear, or be implemented in a different and incompatible way by +the time they are merged in Linux mainline. + +Changes that are backwards-compatible by nature (e.g. the addition of +attributes that do not change the way the other attributes work) do not +always warrant an update of interface_version. Therefore, one must +expect that an attribute might not be there, and deal with it properly +(an attribute not being there *is* a valid way to make it clear that a +feature is not available in sysfs). + + +Hot keys +-------- + +procfs: /proc/acpi/ibm/hotkey + +sysfs device attribute: hotkey_* + +In a ThinkPad, the ACPI HKEY handler is responsible for communicating +some important events and also keyboard hot key presses to the operating +system. Enabling the hotkey functionality of thinkpad-acpi signals the +firmware that such a driver is present, and modifies how the ThinkPad +firmware will behave in many situations. + +The driver enables the HKEY ("hot key") event reporting automatically +when loaded, and disables it when it is removed. + +The driver will report HKEY events in the following format:: + + ibm/hotkey HKEY 00000080 0000xxxx + +Some of these events refer to hot key presses, but not all of them. + +The driver will generate events over the input layer for hot keys and +radio switches, and over the ACPI netlink layer for other events. The +input layer support accepts the standard IOCTLs to remap the keycodes +assigned to each hot key. + +The hot key bit mask allows some control over which hot keys generate +events. If a key is "masked" (bit set to 0 in the mask), the firmware +will handle it. If it is "unmasked", it signals the firmware that +thinkpad-acpi would prefer to handle it, if the firmware would be so +kind to allow it (and it often doesn't!). + +Not all bits in the mask can be modified. Not all bits that can be +modified do anything. Not all hot keys can be individually controlled +by the mask. Some models do not support the mask at all. The behaviour +of the mask is, therefore, highly dependent on the ThinkPad model. + +The driver will filter out any unmasked hotkeys, so even if the firmware +doesn't allow disabling an specific hotkey, the driver will not report +events for unmasked hotkeys. + +Note that unmasking some keys prevents their default behavior. For +example, if Fn+F5 is unmasked, that key will no longer enable/disable +Bluetooth by itself in firmware. + +Note also that not all Fn key combinations are supported through ACPI +depending on the ThinkPad model and firmware version. On those +ThinkPads, it is still possible to support some extra hotkeys by +polling the "CMOS NVRAM" at least 10 times per second. The driver +attempts to enables this functionality automatically when required. + +procfs notes +^^^^^^^^^^^^ + +The following commands can be written to the /proc/acpi/ibm/hotkey file:: + + echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys + echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys + ... any other 8-hex-digit mask ... + echo reset > /proc/acpi/ibm/hotkey -- restore the recommended mask + +The following commands have been deprecated and will cause the kernel +to log a warning:: + + echo enable > /proc/acpi/ibm/hotkey -- does nothing + echo disable > /proc/acpi/ibm/hotkey -- returns an error + +The procfs interface does not support NVRAM polling control. So as to +maintain maximum bug-to-bug compatibility, it does not report any masks, +nor does it allow one to manipulate the hot key mask when the firmware +does not support masks at all, even if NVRAM polling is in use. + +sysfs notes +^^^^^^^^^^^ + + hotkey_bios_enabled: + DEPRECATED, WILL BE REMOVED SOON. + + Returns 0. + + hotkey_bios_mask: + DEPRECATED, DON'T USE, WILL BE REMOVED IN THE FUTURE. + + Returns the hot keys mask when thinkpad-acpi was loaded. + Upon module unload, the hot keys mask will be restored + to this value. This is always 0x80c, because those are + the hotkeys that were supported by ancient firmware + without mask support. + + hotkey_enable: + DEPRECATED, WILL BE REMOVED SOON. + + 0: returns -EPERM + 1: does nothing + + hotkey_mask: + bit mask to enable reporting (and depending on + the firmware, ACPI event generation) for each hot key + (see above). Returns the current status of the hot keys + mask, and allows one to modify it. + + hotkey_all_mask: + bit mask that should enable event reporting for all + supported hot keys, when echoed to hotkey_mask above. + Unless you know which events need to be handled + passively (because the firmware *will* handle them + anyway), do *not* use hotkey_all_mask. Use + hotkey_recommended_mask, instead. You have been warned. + + hotkey_recommended_mask: + bit mask that should enable event reporting for all + supported hot keys, except those which are always + handled by the firmware anyway. Echo it to + hotkey_mask above, to use. This is the default mask + used by the driver. + + hotkey_source_mask: + bit mask that selects which hot keys will the driver + poll the NVRAM for. This is auto-detected by the driver + based on the capabilities reported by the ACPI firmware, + but it can be overridden at runtime. + + Hot keys whose bits are set in hotkey_source_mask are + polled for in NVRAM, and reported as hotkey events if + enabled in hotkey_mask. Only a few hot keys are + available through CMOS NVRAM polling. + + Warning: when in NVRAM mode, the volume up/down/mute + keys are synthesized according to changes in the mixer, + which uses a single volume up or volume down hotkey + press to unmute, as per the ThinkPad volume mixer user + interface. When in ACPI event mode, volume up/down/mute + events are reported by the firmware and can behave + differently (and that behaviour changes with firmware + version -- not just with firmware models -- as well as + OSI(Linux) state). + + hotkey_poll_freq: + frequency in Hz for hot key polling. It must be between + 0 and 25 Hz. Polling is only carried out when strictly + needed. + + Setting hotkey_poll_freq to zero disables polling, and + will cause hot key presses that require NVRAM polling + to never be reported. + + Setting hotkey_poll_freq too low may cause repeated + pressings of the same hot key to be misreported as a + single key press, or to not even be detected at all. + The recommended polling frequency is 10Hz. + + hotkey_radio_sw: + If the ThinkPad has a hardware radio switch, this + attribute will read 0 if the switch is in the "radios + disabled" position, and 1 if the switch is in the + "radios enabled" position. + + This attribute has poll()/select() support. + + hotkey_tablet_mode: + If the ThinkPad has tablet capabilities, this attribute + will read 0 if the ThinkPad is in normal mode, and + 1 if the ThinkPad is in tablet mode. + + This attribute has poll()/select() support. + + wakeup_reason: + Set to 1 if the system is waking up because the user + requested a bay ejection. Set to 2 if the system is + waking up because the user requested the system to + undock. Set to zero for normal wake-ups or wake-ups + due to unknown reasons. + + This attribute has poll()/select() support. + + wakeup_hotunplug_complete: + Set to 1 if the system was waken up because of an + undock or bay ejection request, and that request + was successfully completed. At this point, it might + be useful to send the system back to sleep, at the + user's choice. Refer to HKEY events 0x4003 and + 0x3003, below. + + This attribute has poll()/select() support. + +input layer notes +^^^^^^^^^^^^^^^^^ + +A Hot key is mapped to a single input layer EV_KEY event, possibly +followed by an EV_MSC MSC_SCAN event that shall contain that key's scan +code. An EV_SYN event will always be generated to mark the end of the +event block. + +Do not use the EV_MSC MSC_SCAN events to process keys. They are to be +used as a helper to remap keys, only. They are particularly useful when +remapping KEY_UNKNOWN keys. + +The events are available in an input device, with the following id: + + ============== ============================== + Bus BUS_HOST + vendor 0x1014 (PCI_VENDOR_ID_IBM) or + 0x17aa (PCI_VENDOR_ID_LENOVO) + product 0x5054 ("TP") + version 0x4101 + ============== ============================== + +The version will have its LSB incremented if the keymap changes in a +backwards-compatible way. The MSB shall always be 0x41 for this input +device. If the MSB is not 0x41, do not use the device as described in +this section, as it is either something else (e.g. another input device +exported by a thinkpad driver, such as HDAPS) or its functionality has +been changed in a non-backwards compatible way. + +Adding other event types for other functionalities shall be considered a +backwards-compatible change for this input device. + +Thinkpad-acpi Hot Key event map (version 0x4101): + +======= ======= ============== ============================================== +ACPI Scan +event code Key Notes +======= ======= ============== ============================================== +0x1001 0x00 FN+F1 - + +0x1002 0x01 FN+F2 IBM: battery (rare) + Lenovo: Screen lock + +0x1003 0x02 FN+F3 Many IBM models always report + this hot key, even with hot keys + disabled or with Fn+F3 masked + off + IBM: screen lock, often turns + off the ThinkLight as side-effect + Lenovo: battery + +0x1004 0x03 FN+F4 Sleep button (ACPI sleep button + semantics, i.e. sleep-to-RAM). + It always generates some kind + of event, either the hot key + event or an ACPI sleep button + event. The firmware may + refuse to generate further FN+F4 + key presses until a S3 or S4 ACPI + sleep cycle is performed or some + time passes. + +0x1005 0x04 FN+F5 Radio. Enables/disables + the internal Bluetooth hardware + and W-WAN card if left in control + of the firmware. Does not affect + the WLAN card. + Should be used to turn on/off all + radios (Bluetooth+W-WAN+WLAN), + really. + +0x1006 0x05 FN+F6 - + +0x1007 0x06 FN+F7 Video output cycle. + Do you feel lucky today? + +0x1008 0x07 FN+F8 IBM: toggle screen expand + Lenovo: configure UltraNav, + or toggle screen expand + +0x1009 0x08 FN+F9 - + +... ... ... ... + +0x100B 0x0A FN+F11 - + +0x100C 0x0B FN+F12 Sleep to disk. You are always + supposed to handle it yourself, + either through the ACPI event, + or through a hotkey event. + The firmware may refuse to + generate further FN+F12 key + press events until a S3 or S4 + ACPI sleep cycle is performed, + or some time passes. + +0x100D 0x0C FN+BACKSPACE - +0x100E 0x0D FN+INSERT - +0x100F 0x0E FN+DELETE - + +0x1010 0x0F FN+HOME Brightness up. This key is + always handled by the firmware + in IBM ThinkPads, even when + unmasked. Just leave it alone. + For Lenovo ThinkPads with a new + BIOS, it has to be handled either + by the ACPI OSI, or by userspace. + The driver does the right thing, + never mess with this. +0x1011 0x10 FN+END Brightness down. See brightness + up for details. + +0x1012 0x11 FN+PGUP ThinkLight toggle. This key is + always handled by the firmware, + even when unmasked. + +0x1013 0x12 FN+PGDOWN - + +0x1014 0x13 FN+SPACE Zoom key + +0x1015 0x14 VOLUME UP Internal mixer volume up. This + key is always handled by the + firmware, even when unmasked. + NOTE: Lenovo seems to be changing + this. +0x1016 0x15 VOLUME DOWN Internal mixer volume up. This + key is always handled by the + firmware, even when unmasked. + NOTE: Lenovo seems to be changing + this. +0x1017 0x16 MUTE Mute internal mixer. This + key is always handled by the + firmware, even when unmasked. + +0x1018 0x17 THINKPAD ThinkPad/Access IBM/Lenovo key + +0x1019 0x18 unknown + +... ... ... + +0x1020 0x1F unknown +======= ======= ============== ============================================== + +The ThinkPad firmware does not allow one to differentiate when most hot +keys are pressed or released (either that, or we don't know how to, yet). +For these keys, the driver generates a set of events for a key press and +immediately issues the same set of events for a key release. It is +unknown by the driver if the ThinkPad firmware triggered these events on +hot key press or release, but the firmware will do it for either one, not +both. + +If a key is mapped to KEY_RESERVED, it generates no input events at all. +If a key is mapped to KEY_UNKNOWN, it generates an input event that +includes an scan code. If a key is mapped to anything else, it will +generate input device EV_KEY events. + +In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW +events for switches: + +============== ============================================== +SW_RFKILL_ALL T60 and later hardware rfkill rocker switch +SW_TABLET_MODE Tablet ThinkPads HKEY events 0x5009 and 0x500A +============== ============================================== + +Non hotkey ACPI HKEY event map +------------------------------ + +Events that are never propagated by the driver: + +====== ================================================== +0x2304 System is waking up from suspend to undock +0x2305 System is waking up from suspend to eject bay +0x2404 System is waking up from hibernation to undock +0x2405 System is waking up from hibernation to eject bay +0x5001 Lid closed +0x5002 Lid opened +0x5009 Tablet swivel: switched to tablet mode +0x500A Tablet swivel: switched to normal mode +0x5010 Brightness level changed/control event +0x6000 KEYBOARD: Numlock key pressed +0x6005 KEYBOARD: Fn key pressed (TO BE VERIFIED) +0x7000 Radio Switch may have changed state +====== ================================================== + + +Events that are propagated by the driver to userspace: + +====== ===================================================== +0x2313 ALARM: System is waking up from suspend because + the battery is nearly empty +0x2413 ALARM: System is waking up from hibernation because + the battery is nearly empty +0x3003 Bay ejection (see 0x2x05) complete, can sleep again +0x3006 Bay hotplug request (hint to power up SATA link when + the optical drive tray is ejected) +0x4003 Undocked (see 0x2x04), can sleep again +0x4010 Docked into hotplug port replicator (non-ACPI dock) +0x4011 Undocked from hotplug port replicator (non-ACPI dock) +0x500B Tablet pen inserted into its storage bay +0x500C Tablet pen removed from its storage bay +0x6011 ALARM: battery is too hot +0x6012 ALARM: battery is extremely hot +0x6021 ALARM: a sensor is too hot +0x6022 ALARM: a sensor is extremely hot +0x6030 System thermal table changed +0x6032 Thermal Control command set completion (DYTC, Windows) +0x6040 Nvidia Optimus/AC adapter related (TO BE VERIFIED) +0x60C0 X1 Yoga 2016, Tablet mode status changed +0x60F0 Thermal Transformation changed (GMTS, Windows) +====== ===================================================== + +Battery nearly empty alarms are a last resort attempt to get the +operating system to hibernate or shutdown cleanly (0x2313), or shutdown +cleanly (0x2413) before power is lost. They must be acted upon, as the +wake up caused by the firmware will have negated most safety nets... + +When any of the "too hot" alarms happen, according to Lenovo the user +should suspend or hibernate the laptop (and in the case of battery +alarms, unplug the AC adapter) to let it cool down. These alarms do +signal that something is wrong, they should never happen on normal +operating conditions. + +The "extremely hot" alarms are emergencies. According to Lenovo, the +operating system is to force either an immediate suspend or hibernate +cycle, or a system shutdown. Obviously, something is very wrong if this +happens. + + +Brightness hotkey notes +^^^^^^^^^^^^^^^^^^^^^^^ + +Don't mess with the brightness hotkeys in a Thinkpad. If you want +notifications for OSD, use the sysfs backlight class event support. + +The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events +automatically for the cases were userspace has to do something to +implement brightness changes. When you override these events, you will +either fail to handle properly the ThinkPads that require explicit +action to change backlight brightness, or the ThinkPads that require +that no action be taken to work properly. + + +Bluetooth +--------- + +procfs: /proc/acpi/ibm/bluetooth + +sysfs device attribute: bluetooth_enable (deprecated) + +sysfs rfkill class: switch "tpacpi_bluetooth_sw" + +This feature shows the presence and current state of a ThinkPad +Bluetooth device in the internal ThinkPad CDC slot. + +If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, +so it is kept across reboots and power-off. + +Procfs notes +^^^^^^^^^^^^ + +If Bluetooth is installed, the following commands can be used:: + + echo enable > /proc/acpi/ibm/bluetooth + echo disable > /proc/acpi/ibm/bluetooth + +Sysfs notes +^^^^^^^^^^^ + + If the Bluetooth CDC card is installed, it can be enabled / + disabled through the "bluetooth_enable" thinkpad-acpi device + attribute, and its current status can also be queried. + + enable: + + - 0: disables Bluetooth / Bluetooth is disabled + - 1: enables Bluetooth / Bluetooth is enabled. + + Note: this interface has been superseded by the generic rfkill + class. It has been deprecated, and it will be removed in year + 2010. + + rfkill controller switch "tpacpi_bluetooth_sw": refer to + Documentation/driver-api/rfkill.rst for details. + + +Video output control -- /proc/acpi/ibm/video +-------------------------------------------- + +This feature allows control over the devices used for video output - +LCD, CRT or DVI (if available). The following commands are available:: + + echo lcd_enable > /proc/acpi/ibm/video + echo lcd_disable > /proc/acpi/ibm/video + echo crt_enable > /proc/acpi/ibm/video + echo crt_disable > /proc/acpi/ibm/video + echo dvi_enable > /proc/acpi/ibm/video + echo dvi_disable > /proc/acpi/ibm/video + echo auto_enable > /proc/acpi/ibm/video + echo auto_disable > /proc/acpi/ibm/video + echo expand_toggle > /proc/acpi/ibm/video + echo video_switch > /proc/acpi/ibm/video + +NOTE: + Access to this feature is restricted to processes owning the + CAP_SYS_ADMIN capability for safety reasons, as it can interact badly + enough with some versions of X.org to crash it. + +Each video output device can be enabled or disabled individually. +Reading /proc/acpi/ibm/video shows the status of each device. + +Automatic video switching can be enabled or disabled. When automatic +video switching is enabled, certain events (e.g. opening the lid, +docking or undocking) cause the video output device to change +automatically. While this can be useful, it also causes flickering +and, on the X40, video corruption. By disabling automatic switching, +the flickering or video corruption can be avoided. + +The video_switch command cycles through the available video outputs +(it simulates the behavior of Fn-F7). + +Video expansion can be toggled through this feature. This controls +whether the display is expanded to fill the entire LCD screen when a +mode with less than full resolution is used. Note that the current +video expansion status cannot be determined through this feature. + +Note that on many models (particularly those using Radeon graphics +chips) the X driver configures the video card in a way which prevents +Fn-F7 from working. This also disables the video output switching +features of this driver, as it uses the same ACPI methods as +Fn-F7. Video switching on the console should still work. + +UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 + + +ThinkLight control +------------------ + +procfs: /proc/acpi/ibm/light + +sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED + +procfs notes +^^^^^^^^^^^^ + +The ThinkLight status can be read and set through the procfs interface. A +few models which do not make the status available will show the ThinkLight +status as "unknown". The available commands are:: + + echo on > /proc/acpi/ibm/light + echo off > /proc/acpi/ibm/light + +sysfs notes +^^^^^^^^^^^ + +The ThinkLight sysfs interface is documented by the LED class +documentation, in Documentation/leds/leds-class.rst. The ThinkLight LED name +is "tpacpi::thinklight". + +Due to limitations in the sysfs LED class, if the status of the ThinkLight +cannot be read or if it is unknown, thinkpad-acpi will report it as "off". +It is impossible to know if the status returned through sysfs is valid. + + +CMOS/UCMS control +----------------- + +procfs: /proc/acpi/ibm/cmos + +sysfs device attribute: cmos_command + +This feature is mostly used internally by the ACPI firmware to keep the legacy +CMOS NVRAM bits in sync with the current machine state, and to record this +state so that the ThinkPad will retain such settings across reboots. + +Some of these commands actually perform actions in some ThinkPad models, but +this is expected to disappear more and more in newer models. As an example, in +a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for +real, but commands 0 to 2 don't control the mixer anymore (they have been +phased out) and just update the NVRAM. + +The range of valid cmos command numbers is 0 to 21, but not all have an +effect and the behavior varies from model to model. Here is the behavior +on the X40 (tpb is the ThinkPad Buttons utility): + + - 0 - Related to "Volume down" key press + - 1 - Related to "Volume up" key press + - 2 - Related to "Mute on" key press + - 3 - Related to "Access IBM" key press + - 4 - Related to "LCD brightness up" key press + - 5 - Related to "LCD brightness down" key press + - 11 - Related to "toggle screen expansion" key press/function + - 12 - Related to "ThinkLight on" + - 13 - Related to "ThinkLight off" + - 14 - Related to "ThinkLight" key press (toggle ThinkLight) + +The cmos command interface is prone to firmware split-brain problems, as +in newer ThinkPads it is just a compatibility layer. Do not use it, it is +exported just as a debug tool. + + +LED control +----------- + +procfs: /proc/acpi/ibm/led +sysfs attributes: as per LED class, see below for names + +Some of the LED indicators can be controlled through this feature. On +some older ThinkPad models, it is possible to query the status of the +LED indicators as well. Newer ThinkPads cannot query the real status +of the LED indicators. + +Because misuse of the LEDs could induce an unaware user to perform +dangerous actions (like undocking or ejecting a bay device while the +buses are still active), or mask an important alarm (such as a nearly +empty battery, or a broken battery), access to most LEDs is +restricted. + +Unrestricted access to all LEDs requires that thinkpad-acpi be +compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. +Distributions must never enable this option. Individual users that +are aware of the consequences are welcome to enabling it. + +Audio mute and microphone mute LEDs are supported, but currently not +visible to userspace. They are used by the snd-hda-intel audio driver. + +procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo '<LED number> on' >/proc/acpi/ibm/led + echo '<LED number> off' >/proc/acpi/ibm/led + echo '<LED number> blink' >/proc/acpi/ibm/led + +The <LED number> range is 0 to 15. The set of LEDs that can be +controlled varies from model to model. Here is the common ThinkPad +mapping: + + - 0 - power + - 1 - battery (orange) + - 2 - battery (green) + - 3 - UltraBase/dock + - 4 - UltraBay + - 5 - UltraBase battery slot + - 6 - (unknown) + - 7 - standby + - 8 - dock status 1 + - 9 - dock status 2 + - 10, 11 - (unknown) + - 12 - thinkvantage + - 13, 14, 15 - (unknown) + +All of the above can be turned on and off and can be made to blink. + +sysfs notes +^^^^^^^^^^^ + +The ThinkPad LED sysfs interface is described in detail by the LED class +documentation, in Documentation/leds/leds-class.rst. + +The LEDs are named (in LED ID order, from 0 to 12): +"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", +"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", +"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", +"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", +"tpacpi::thinkvantage". + +Due to limitations in the sysfs LED class, if the status of the LED +indicators cannot be read due to an error, thinkpad-acpi will report it as +a brightness of zero (same as LED off). + +If the thinkpad firmware doesn't support reading the current status, +trying to read the current LED brightness will just return whatever +brightness was last written to that attribute. + +These LEDs can blink using hardware acceleration. To request that a +ThinkPad indicator LED should blink in hardware accelerated mode, use the +"timer" trigger, and leave the delay_on and delay_off parameters set to +zero (to request hardware acceleration autodetection). + +LEDs that are known not to exist in a given ThinkPad model are not +made available through the sysfs interface. If you have a dock and you +notice there are LEDs listed for your ThinkPad that do not exist (and +are not in the dock), or if you notice that there are missing LEDs, +a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. + + +ACPI sounds -- /proc/acpi/ibm/beep +---------------------------------- + +The BEEP method is used internally by the ACPI firmware to provide +audible alerts in various situations. This feature allows the same +sounds to be triggered manually. + +The commands are non-negative integer numbers:: + + echo <number> >/proc/acpi/ibm/beep + +The valid <number> range is 0 to 17. Not all numbers trigger sounds +and the sounds vary from model to model. Here is the behavior on the +X40: + + - 0 - stop a sound in progress (but use 17 to stop 16) + - 2 - two beeps, pause, third beep ("low battery") + - 3 - single beep + - 4 - high, followed by low-pitched beep ("unable") + - 5 - single beep + - 6 - very high, followed by high-pitched beep ("AC/DC") + - 7 - high-pitched beep + - 9 - three short beeps + - 10 - very long beep + - 12 - low-pitched beep + - 15 - three high-pitched beeps repeating constantly, stop with 0 + - 16 - one medium-pitched beep repeating constantly, stop with 17 + - 17 - stop 16 + + +Temperature sensors +------------------- + +procfs: /proc/acpi/ibm/thermal + +sysfs device attributes: (hwmon "thinkpad") temp*_input + +Most ThinkPads include six or more separate temperature sensors but only +expose the CPU temperature through the standard ACPI methods. This +feature shows readings from up to eight different sensors on older +ThinkPads, and up to sixteen different sensors on newer ThinkPads. + +For example, on the X40, a typical output may be: + +temperatures: + 42 42 45 41 36 -128 33 -128 + +On the T43/p, a typical output may be: + +temperatures: + 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 + +The mapping of thermal sensors to physical locations varies depending on +system-board model (and thus, on ThinkPad model). + +https://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that +tries to track down these locations for various models. + +Most (newer?) models seem to follow this pattern: + +- 1: CPU +- 2: (depends on model) +- 3: (depends on model) +- 4: GPU +- 5: Main battery: main sensor +- 6: Bay battery: main sensor +- 7: Main battery: secondary sensor +- 8: Bay battery: secondary sensor +- 9-15: (depends on model) + +For the R51 (source: Thomas Gruber): + +- 2: Mini-PCI +- 3: Internal HDD + +For the T43, T43/p (source: Shmidoax/Thinkwiki.org) +https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p + +- 2: System board, left side (near PCMCIA slot), reported as HDAPS temp +- 3: PCMCIA slot +- 9: MCH (northbridge) to DRAM Bus +- 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI + card, under touchpad +- 11: Power regulator, underside of system board, below F2 key + +The A31 has a very atypical layout for the thermal sensors +(source: Milos Popovic, https://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) + +- 1: CPU +- 2: Main Battery: main sensor +- 3: Power Converter +- 4: Bay Battery: main sensor +- 5: MCH (northbridge) +- 6: PCMCIA/ambient +- 7: Main Battery: secondary sensor +- 8: Bay Battery: secondary sensor + + +Procfs notes +^^^^^^^^^^^^ + + Readings from sensors that are not available return -128. + No commands can be written to this file. + +Sysfs notes +^^^^^^^^^^^ + + Sensors that are not available return the ENXIO error. This + status may change at runtime, as there are hotplug thermal + sensors, like those inside the batteries and docks. + + thinkpad-acpi thermal sensors are reported through the hwmon + subsystem, and follow all of the hwmon guidelines at + Documentation/hwmon. + +EXPERIMENTAL: Embedded controller register dump +----------------------------------------------- + +This feature is not included in the thinkpad driver anymore. +Instead the EC can be accessed through /sys/kernel/debug/ec with +a userspace tool which can be found here: +ftp://ftp.suse.com/pub/people/trenn/sources/ec + +Use it to determine the register holding the fan +speed on some models. To do that, do the following: + + - make sure the battery is fully charged + - make sure the fan is running + - use above mentioned tool to read out the EC + +Often fan and temperature values vary between +readings. Since temperatures don't change vary fast, you can take +several quick dumps to eliminate them. + +You can use a similar method to figure out the meaning of other +embedded controller registers - e.g. make sure nothing else changes +except the charging or discharging battery to determine which +registers contain the current battery capacity, etc. If you experiment +with this, do send me your results (including some complete dumps with +a description of the conditions when they were taken.) + + +LCD brightness control +---------------------- + +procfs: /proc/acpi/ibm/brightness + +sysfs backlight device "thinkpad_screen" + +This feature allows software control of the LCD brightness on ThinkPad +models which don't have a hardware brightness slider. + +It has some limitations: the LCD backlight cannot be actually turned +on or off by this interface, it just controls the backlight brightness +level. + +On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control +has eight brightness levels, ranging from 0 to 7. Some of the levels +may not be distinct. Later Lenovo models that implement the ACPI +display backlight brightness control methods have 16 levels, ranging +from 0 to 15. + +For IBM ThinkPads, there are two interfaces to the firmware for direct +brightness control, EC and UCMS (or CMOS). To select which one should be +used, use the brightness_mode module parameter: brightness_mode=1 selects +EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC +mode with NVRAM backing (so that brightness changes are remembered across +shutdown/reboot). + +The driver tries to select which interface to use from a table of +defaults for each ThinkPad model. If it makes a wrong choice, please +report this as a bug, so that we can fix it. + +Lenovo ThinkPads only support brightness_mode=2 (UCMS). + +When display backlight brightness controls are available through the +standard ACPI interface, it is best to use it instead of this direct +ThinkPad-specific interface. The driver will disable its native +backlight brightness control interface if it detects that the standard +ACPI interface is available in the ThinkPad. + +If you want to use the thinkpad-acpi backlight brightness control +instead of the generic ACPI video backlight brightness control for some +reason, you should use the acpi_backlight=vendor kernel parameter. + +The brightness_enable module parameter can be used to control whether +the LCD brightness control feature will be enabled when available. +brightness_enable=0 forces it to be disabled. brightness_enable=1 +forces it to be enabled when available, even if the standard ACPI +interface is also available. + +Procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo up >/proc/acpi/ibm/brightness + echo down >/proc/acpi/ibm/brightness + echo 'level <level>' >/proc/acpi/ibm/brightness + +Sysfs notes +^^^^^^^^^^^ + +The interface is implemented through the backlight sysfs class, which is +poorly documented at this time. + +Locate the thinkpad_screen device under /sys/class/backlight, and inside +it there will be the following attributes: + + max_brightness: + Reads the maximum brightness the hardware can be set to. + The minimum is always zero. + + actual_brightness: + Reads what brightness the screen is set to at this instant. + + brightness: + Writes request the driver to change brightness to the + given value. Reads will tell you what brightness the + driver is trying to set the display to when "power" is set + to zero and the display has not been dimmed by a kernel + power management event. + + power: + power management mode, where 0 is "display on", and 1 to 3 + will dim the display backlight to brightness level 0 + because thinkpad-acpi cannot really turn the backlight + off. Kernel power management events can temporarily + increase the current power management level, i.e. they can + dim the display. + + +WARNING: + + Whatever you do, do NOT ever call thinkpad-acpi backlight-level change + interface and the ACPI-based backlight level change interface + (available on newer BIOSes, and driven by the Linux ACPI video driver) + at the same time. The two will interact in bad ways, do funny things, + and maybe reduce the life of the backlight lamps by needlessly kicking + its level up and down at every change. + + +Volume control (Console Audio control) +-------------------------------------- + +procfs: /proc/acpi/ibm/volume + +ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" + +NOTE: by default, the volume control interface operates in read-only +mode, as it is supposed to be used for on-screen-display purposes. +The read/write mode can be enabled through the use of the +"volume_control=1" module parameter. + +NOTE: distros are urged to not enable volume_control by default, this +should be done by the local admin only. The ThinkPad UI is for the +console audio control to be done through the volume keys only, and for +the desktop environment to just provide on-screen-display feedback. +Software volume control should be done only in the main AC97/HDA +mixer. + + +About the ThinkPad Console Audio control +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +ThinkPads have a built-in amplifier and muting circuit that drives the +console headphone and speakers. This circuit is after the main AC97 +or HDA mixer in the audio path, and under exclusive control of the +firmware. + +ThinkPads have three special hotkeys to interact with the console +audio control: volume up, volume down and mute. + +It is worth noting that the normal way the mute function works (on +ThinkPads that do not have a "mute LED") is: + +1. Press mute to mute. It will *always* mute, you can press it as + many times as you want, and the sound will remain mute. + +2. Press either volume key to unmute the ThinkPad (it will _not_ + change the volume, it will just unmute). + +This is a very superior design when compared to the cheap software-only +mute-toggle solution found on normal consumer laptops: you can be +absolutely sure the ThinkPad will not make noise if you press the mute +button, no matter the previous state. + +The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain +amplifiers driving the speakers and headphone output, and the firmware +also handles volume control for the headphone and speakers on these +ThinkPads without any help from the operating system (this volume +control stage exists after the main AC97 or HDA mixer in the audio +path). + +The newer Lenovo models only have firmware mute control, and depend on +the main HDA mixer to do volume control (which is done by the operating +system). In this case, the volume keys are filtered out for unmute +key press (there are some firmware bugs in this area) and delivered as +normal key presses to the operating system (thinkpad-acpi is not +involved). + + +The ThinkPad-ACPI volume control +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The preferred way to interact with the Console Audio control is the +ALSA interface. + +The legacy procfs interface allows one to read the current state, +and if volume control is enabled, accepts the following commands:: + + echo up >/proc/acpi/ibm/volume + echo down >/proc/acpi/ibm/volume + echo mute >/proc/acpi/ibm/volume + echo unmute >/proc/acpi/ibm/volume + echo 'level <level>' >/proc/acpi/ibm/volume + +The <level> number range is 0 to 14 although not all of them may be +distinct. To unmute the volume after the mute command, use either the +up or down command (the level command will not unmute the volume), or +the unmute command. + +You can use the volume_capabilities parameter to tell the driver +whether your thinkpad has volume control or mute-only control: +volume_capabilities=1 for mixers with mute and volume control, +volume_capabilities=2 for mixers with only mute control. + +If the driver misdetects the capabilities for your ThinkPad model, +please report this to ibm-acpi-devel@lists.sourceforge.net, so that we +can update the driver. + +There are two strategies for volume control. To select which one +should be used, use the volume_mode module parameter: volume_mode=1 +selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing +(so that volume/mute changes are remembered across shutdown/reboot). + +The driver will operate in volume_mode=3 by default. If that does not +work well on your ThinkPad model, please report this to +ibm-acpi-devel@lists.sourceforge.net. + +The driver supports the standard ALSA module parameters. If the ALSA +mixer is disabled, the driver will disable all volume functionality. + + +Fan control and monitoring: fan speed, fan enable/disable +--------------------------------------------------------- + +procfs: /proc/acpi/ibm/fan + +sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, pwm1_enable, fan2_input + +sysfs hwmon driver attributes: fan_watchdog + +NOTE NOTE NOTE: + fan control operations are disabled by default for + safety reasons. To enable them, the module parameter "fan_control=1" + must be given to thinkpad-acpi. + +This feature attempts to show the current fan speed, control mode and +other fan data that might be available. The speed is read directly +from the hardware registers of the embedded controller. This is known +to work on later R, T, X and Z series ThinkPads but may show a bogus +value on other models. + +Some Lenovo ThinkPads support a secondary fan. This fan cannot be +controlled separately, it shares the main fan control. + +Fan levels +^^^^^^^^^^ + +Most ThinkPad fans work in "levels" at the firmware interface. Level 0 +stops the fan. The higher the level, the higher the fan speed, although +adjacent levels often map to the same fan speed. 7 is the highest +level, where the fan reaches the maximum recommended speed. + +Level "auto" means the EC changes the fan level according to some +internal algorithm, usually based on readings from the thermal sensors. + +There is also a "full-speed" level, also known as "disengaged" level. +In this level, the EC disables the speed-locked closed-loop fan control, +and drives the fan as fast as it can go, which might exceed hardware +limits, so use this level with caution. + +The fan usually ramps up or down slowly from one speed to another, and +it is normal for the EC to take several seconds to react to fan +commands. The full-speed level may take up to two minutes to ramp up to +maximum speed, and in some ThinkPads, the tachometer readings go stale +while the EC is transitioning to the full-speed level. + +WARNING WARNING WARNING: do not leave the fan disabled unless you are +monitoring all of the temperature sensor readings and you are ready to +enable it if necessary to avoid overheating. + +An enabled fan in level "auto" may stop spinning if the EC decides the +ThinkPad is cool enough and doesn't need the extra airflow. This is +normal, and the EC will spin the fan up if the various thermal readings +rise too much. + +On the X40, this seems to depend on the CPU and HDD temperatures. +Specifically, the fan is turned on when either the CPU temperature +climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The +fan is turned off when the CPU temperature drops to 49 degrees and the +HDD temperature drops to 41 degrees. These thresholds cannot +currently be controlled. + +The ThinkPad's ACPI DSDT code will reprogram the fan on its own when +certain conditions are met. It will override any fan programming done +through thinkpad-acpi. + +The thinkpad-acpi kernel driver can be programmed to revert the fan +level to a safe setting if userspace does not issue one of the procfs +fan commands: "enable", "disable", "level" or "watchdog", or if there +are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is +set to 1, manual mode) within a configurable amount of time of up to +120 seconds. This functionality is called fan safety watchdog. + +Note that the watchdog timer stops after it enables the fan. It will be +rearmed again automatically (using the same interval) when one of the +above mentioned fan commands is received. The fan watchdog is, +therefore, not suitable to protect against fan mode changes made through +means other than the "enable", "disable", and "level" procfs fan +commands, or the hwmon fan control sysfs interface. + +Procfs notes +^^^^^^^^^^^^ + +The fan may be enabled or disabled with the following commands:: + + echo enable >/proc/acpi/ibm/fan + echo disable >/proc/acpi/ibm/fan + +Placing a fan on level 0 is the same as disabling it. Enabling a fan +will try to place it in a safe level if it is too slow or disabled. + +The fan level can be controlled with the command:: + + echo 'level <level>' > /proc/acpi/ibm/fan + +Where <level> is an integer from 0 to 7, or one of the words "auto" or +"full-speed" (without the quotes). Not all ThinkPads support the "auto" +and "full-speed" levels. The driver accepts "disengaged" as an alias for +"full-speed", and reports it as "disengaged" for backwards +compatibility. + +On the X31 and X40 (and ONLY on those models), the fan speed can be +controlled to a certain degree. Once the fan is running, it can be +forced to run faster or slower with the following command:: + + echo 'speed <speed>' > /proc/acpi/ibm/fan + +The sustainable range of fan speeds on the X40 appears to be from about +3700 to about 7350. Values outside this range either do not have any +effect or the fan speed eventually settles somewhere in that range. The +fan cannot be stopped or started with this command. This functionality +is incomplete, and not available through the sysfs interface. + +To program the safety watchdog, use the "watchdog" command:: + + echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan + +If you want to disable the watchdog, use 0 as the interval. + +Sysfs notes +^^^^^^^^^^^ + +The sysfs interface follows the hwmon subsystem guidelines for the most +part, and the exception is the fan safety watchdog. + +Writes to any of the sysfs attributes may return the EINVAL error if +that operation is not supported in a given ThinkPad or if the parameter +is out-of-bounds, and EPERM if it is forbidden. They may also return +EINTR (interrupted system call), and EIO (I/O error while trying to talk +to the firmware). + +Features not yet implemented by the driver return ENOSYS. + +hwmon device attribute pwm1_enable: + - 0: PWM offline (fan is set to full-speed mode) + - 1: Manual PWM control (use pwm1 to set fan level) + - 2: Hardware PWM control (EC "auto" mode) + - 3: reserved (Software PWM control, not implemented yet) + + Modes 0 and 2 are not supported by all ThinkPads, and the + driver is not always able to detect this. If it does know a + mode is unsupported, it will return -EINVAL. + +hwmon device attribute pwm1: + Fan level, scaled from the firmware values of 0-7 to the hwmon + scale of 0-255. 0 means fan stopped, 255 means highest normal + speed (level 7). + + This attribute only commands the fan if pmw1_enable is set to 1 + (manual PWM control). + +hwmon device attribute fan1_input: + Fan tachometer reading, in RPM. May go stale on certain + ThinkPads while the EC transitions the PWM to offline mode, + which can take up to two minutes. May return rubbish on older + ThinkPads. + +hwmon device attribute fan2_input: + Fan tachometer reading, in RPM, for the secondary fan. + Available only on some ThinkPads. If the secondary fan is + not installed, will always read 0. + +hwmon driver attribute fan_watchdog: + Fan safety watchdog timer interval, in seconds. Minimum is + 1 second, maximum is 120 seconds. 0 disables the watchdog. + +To stop the fan: set pwm1 to zero, and pwm1_enable to 1. + +To start the fan in a safe mode: set pwm1_enable to 2. If that fails +with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255 +would be the safest choice, though). + + +WAN +--- + +procfs: /proc/acpi/ibm/wan + +sysfs device attribute: wwan_enable (deprecated) + +sysfs rfkill class: switch "tpacpi_wwan_sw" + +This feature shows the presence and current state of the built-in +Wireless WAN device. + +If the ThinkPad supports it, the WWAN state is stored in NVRAM, +so it is kept across reboots and power-off. + +It was tested on a Lenovo ThinkPad X60. It should probably work on other +ThinkPad models which come with this module installed. + +Procfs notes +^^^^^^^^^^^^ + +If the W-WAN card is installed, the following commands can be used:: + + echo enable > /proc/acpi/ibm/wan + echo disable > /proc/acpi/ibm/wan + +Sysfs notes +^^^^^^^^^^^ + + If the W-WAN card is installed, it can be enabled / + disabled through the "wwan_enable" thinkpad-acpi device + attribute, and its current status can also be queried. + + enable: + - 0: disables WWAN card / WWAN card is disabled + - 1: enables WWAN card / WWAN card is enabled. + + Note: this interface has been superseded by the generic rfkill + class. It has been deprecated, and it will be removed in year + 2010. + + rfkill controller switch "tpacpi_wwan_sw": refer to + Documentation/driver-api/rfkill.rst for details. + + +LCD Shadow control +------------------ + +procfs: /proc/acpi/ibm/lcdshadow + +Some newer T480s and T490s ThinkPads provide a feature called +PrivacyGuard. By turning this feature on, the usable vertical and +horizontal viewing angles of the LCD can be limited (as if some privacy +screen was applied manually in front of the display). + +procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo '0' >/proc/acpi/ibm/lcdshadow + echo '1' >/proc/acpi/ibm/lcdshadow + +The first command ensures the best viewing angle and the latter one turns +on the feature, restricting the viewing angles. + + +DYTC Lapmode sensor +------------------- + +sysfs: dytc_lapmode + +Newer thinkpads and mobile workstations have the ability to determine if +the device is in deskmode or lapmode. This feature is used by user space +to decide if WWAN transmission can be increased to maximum power and is +also useful for understanding the different thermal modes available as +they differ between desk and lap mode. + +The property is read-only. If the platform doesn't have support the sysfs +class is not created. + +EXPERIMENTAL: UWB +----------------- + +This feature is considered EXPERIMENTAL because it has not been extensively +tested and validated in various ThinkPad models yet. The feature may not +work as expected. USE WITH CAUTION! To use this feature, you need to supply +the experimental=1 parameter when loading the module. + +sysfs rfkill class: switch "tpacpi_uwb_sw" + +This feature exports an rfkill controller for the UWB device, if one is +present and enabled in the BIOS. + +Sysfs notes +^^^^^^^^^^^ + + rfkill controller switch "tpacpi_uwb_sw": refer to + Documentation/driver-api/rfkill.rst for details. + + +Setting keyboard language +------------------------- + +sysfs: keyboard_lang + +This feature is used to set keyboard language to ECFW using ASL interface. +Fewer thinkpads models like T580 , T590 , T15 Gen 1 etc.. has "=", "(', +")" numeric keys, which are not displaying correctly, when keyboard language +is other than "english". This is because the default keyboard language in ECFW +is set as "english". Hence using this sysfs, user can set the correct keyboard +language to ECFW and then these key's will work correctly. + +Example of command to set keyboard language is mentioned below:: + + echo jp > /sys/devices/platform/thinkpad_acpi/keyboard_lang + +Text corresponding to keyboard layout to be set in sysfs are: be(Belgian), +cz(Czech), da(Danish), de(German), en(English), es(Spain), et(Estonian), +fr(French), fr-ch(French(Switzerland)), hu(Hungarian), it(Italy), jp (Japan), +nl(Dutch), nn(Norway), pl(Polish), pt(portuguese), sl(Slovenian), sv(Sweden), +tr(Turkey) + +WWAN Antenna type +----------------- + +sysfs: wwan_antenna_type + +On some newer Thinkpads we need to set SAR value based on the antenna +type. This interface will be used by userspace to get the antenna type +and set the corresponding SAR value, as is required for FCC certification. + +The available commands are:: + + cat /sys/devices/platform/thinkpad_acpi/wwan_antenna_type + +Currently 2 antenna types are supported as mentioned below: +- type a +- type b + +The property is read-only. If the platform doesn't have support the sysfs +class is not created. + +Adaptive keyboard +----------------- + +sysfs device attribute: adaptive_kbd_mode + +This sysfs attribute controls the keyboard "face" that will be shown on the +Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read +and set. + +- 0 = Home mode +- 1 = Web-browser mode +- 2 = Web-conference mode +- 3 = Function mode +- 4 = Layflat mode + +For more details about which buttons will appear depending on the mode, please +review the laptop's user guide: +https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf + +Battery charge control +---------------------- + +sysfs attributes: +/sys/class/power_supply/BAT*/charge_control_{start,end}_threshold + +These two attributes are created for those batteries that are supported by the +driver. They enable the user to control the battery charge thresholds of the +given battery. Both values may be read and set. `charge_control_start_threshold` +accepts an integer between 0 and 99 (inclusive); this value represents a battery +percentage level, below which charging will begin. `charge_control_end_threshold` +accepts an integer between 1 and 100 (inclusive); this value represents a battery +percentage level, above which charging will stop. + +The exact semantics of the attributes may be found in +Documentation/ABI/testing/sysfs-class-power. + +Multiple Commands, Module Parameters +------------------------------------ + +Multiple commands can be written to the proc files in one shot by +separating them with commas, for example:: + + echo enable,0xffff > /proc/acpi/ibm/hotkey + echo lcd_disable,crt_enable > /proc/acpi/ibm/video + +Commands can also be specified when loading the thinkpad-acpi module, +for example:: + + modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable + + +Enabling debugging output +------------------------- + +The module takes a debug parameter which can be used to selectively +enable various classes of debugging output, for example:: + + modprobe thinkpad_acpi debug=0xffff + +will enable all debugging output classes. It takes a bitmask, so +to enable more than one output class, just add their values. + + ============= ====================================== + Debug bitmask Description + ============= ====================================== + 0x8000 Disclose PID of userspace programs + accessing some functions of the driver + 0x0001 Initialization and probing + 0x0002 Removal + 0x0004 RF Transmitter control (RFKILL) + (bluetooth, WWAN, UWB...) + 0x0008 HKEY event interface, hotkeys + 0x0010 Fan control + 0x0020 Backlight brightness + 0x0040 Audio mixer/volume control + ============= ====================================== + +There is also a kernel build option to enable more debugging +information, which may be necessary to debug driver problems. + +The level of debugging information output by the driver can be changed +at runtime through sysfs, using the driver attribute debug_level. The +attribute takes the same bitmask as the debug module parameter above. + + +Force loading of module +----------------------- + +If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify +the module parameter force_load=1. Regardless of whether this works or +not, please contact ibm-acpi-devel@lists.sourceforge.net with a report. + + +Sysfs interface changelog +^^^^^^^^^^^^^^^^^^^^^^^^^ + +========= =============================================================== +0x000100: Initial sysfs support, as a single platform driver and + device. +0x000200: Hot key support for 32 hot keys, and radio slider switch + support. +0x010000: Hot keys are now handled by default over the input + layer, the radio switch generates input event EV_RADIO, + and the driver enables hot key handling by default in + the firmware. + +0x020000: ABI fix: added a separate hwmon platform device and + driver, which must be located by name (thinkpad) + and the hwmon class for libsensors4 (lm-sensors 3) + compatibility. Moved all hwmon attributes to this + new platform device. + +0x020100: Marker for thinkpad-acpi with hot key NVRAM polling + support. If you must, use it to know you should not + start a userspace NVRAM poller (allows to detect when + NVRAM is compiled out by the user because it is + unneeded/undesired in the first place). +0x020101: Marker for thinkpad-acpi with hot key NVRAM polling + and proper hotkey_mask semantics (version 8 of the + NVRAM polling patch). Some development snapshots of + 0.18 had an earlier version that did strange things + to hotkey_mask. + +0x020200: Add poll()/select() support to the following attributes: + hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason + +0x020300: hotkey enable/disable support removed, attributes + hotkey_bios_enabled and hotkey_enable deprecated and + marked for removal. + +0x020400: Marker for 16 LEDs support. Also, LEDs that are known + to not exist in a given model are not registered with + the LED sysfs class anymore. + +0x020500: Updated hotkey driver, hotkey_mask is always available + and it is always able to disable hot keys. Very old + thinkpads are properly supported. hotkey_bios_mask + is deprecated and marked for removal. + +0x020600: Marker for backlight change event support. + +0x020700: Support for mute-only mixers. + Volume control in read-only mode by default. + Marker for ALSA mixer support. + +0x030000: Thermal and fan sysfs attributes were moved to the hwmon + device instead of being attached to the backing platform + device. +========= =============================================================== |