Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 3372 insertions, 0 deletions

diff --git a/Documentation/admin-guide/laptops/asus-laptop.rst b/Documentation/admin-guide/laptops/asus-laptop.rst
new file mode 100644
index 000000000..95176321a
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@@ -0,0 +1,271 @@
+==================
+Asus Laptop Extras
+==================
+
+Version 0.1
+
+August 6, 2009
+
+Corentin Chary <corentincj@iksaif.net>
+http://acpi4asus.sf.net/
+
+ This driver provides support for extra features of ACPI-compatible ASUS laptops.
+ It may also support some MEDION, JVC or VICTOR laptops (such as MEDION 9675 or
+ VICTOR XP7210 for example). It makes all the extra buttons generate input
+ events (like keyboards).
+
+ On some models adds support for changing the display brightness and output,
+ switching the LCD backlight on and off, and most importantly, allows you to
+ blink those fancy LEDs intended for reporting mail and wireless status.
+
+This driver supersedes the old asus_acpi driver.
+
+Requirements
+------------
+
+  Kernel 2.6.X sources, configured for your computer, with ACPI support.
+  You also need CONFIG_INPUT and CONFIG_ACPI.
+
+Status
+------
+
+ The features currently supported are the following (see below for
+ detailed description):
+
+ - Fn key combinations
+ - Bluetooth enable and disable
+ - Wlan enable and disable
+ - GPS enable and disable
+ - Video output switching
+ - Ambient Light Sensor on and off
+ - LED control
+ - LED Display control
+ - LCD brightness control
+ - LCD on and off
+
+ A compatibility table by model and feature is maintained on the web
+ site, http://acpi4asus.sf.net/.
+
+Usage
+-----
+
+  Try "modprobe asus-laptop". Check your dmesg (simply type dmesg). You should
+  see some lines like this :
+
+      Asus Laptop Extras version 0.42
+        - L2D model detected.
+
+  If it is not the output you have on your laptop, send it (and the laptop's
+  DSDT) to me.
+
+  That's all, now, all the events generated by the hotkeys of your laptop
+  should be reported via netlink events. You can check with
+  "acpi_genl monitor" (part of the acpica project).
+
+  Hotkeys are also reported as input keys (like keyboards) you can check
+  which key are supported using "xev" under X11.
+
+  You can get information on the version of your DSDT table by reading the
+  /sys/devices/platform/asus-laptop/infos entry. If you have a question or a
+  bug report to do, please include the output of this entry.
+
+LEDs
+----
+
+  You can modify LEDs be echoing values to `/sys/class/leds/asus/*/brightness`::
+
+    echo 1 >  /sys/class/leds/asus::mail/brightness
+
+  will switch the mail LED on.
+
+  You can also know if they are on/off by reading their content and use
+  kernel triggers like disk-activity or heartbeat.
+
+Backlight
+---------
+
+  You can control lcd backlight power and brightness with
+  /sys/class/backlight/asus-laptop/. Brightness Values are between 0 and 15.
+
+Wireless devices
+----------------
+
+  You can turn the internal Bluetooth adapter on/off with the bluetooth entry
+  (only on models with Bluetooth). This usually controls the associated LED.
+  Same for Wlan adapter.
+
+Display switching
+-----------------
+
+  Note: the display switching code is currently considered EXPERIMENTAL.
+
+  Switching works for the following models:
+
+    - L3800C
+    - A2500H
+    - L5800C
+    - M5200N
+    - W1000N (albeit with some glitches)
+    - M6700R
+    - A6JC
+    - F3J
+
+  Switching doesn't work for the following:
+
+    - M3700N
+    - L2X00D (locks the laptop under certain conditions)
+
+  To switch the displays, echo values from 0 to 15 to
+  /sys/devices/platform/asus-laptop/display. The significance of those values
+  is as follows:
+
+  +-------+-----+-----+-----+-----+-----+
+  | Bin   | Val | DVI | TV  | CRT | LCD |
+  +-------+-----+-----+-----+-----+-----+
+  | 0000  |   0 |     |     |     |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 0001  |   1 |     |     |     |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 0010  |   2 |     |     |  X  |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 0011  |   3 |     |     |  X  |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 0100  |   4 |     |  X  |     |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 0101  |   5 |     |  X  |     | X   |
+  +-------+-----+-----+-----+-----+-----+
+  | 0110  |   6 |     |  X  |  X  |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 0111  |   7 |     |  X  |  X  |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 1000  |   8 |  X  |     |     |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 1001  |   9 |  X  |     |     |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 1010  |  10 |  X  |     |  X  |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 1011  |  11 |  X  |     |  X  |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 1100  |  12 |  X  |  X  |     |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 1101  |  13 |  X  |  X  |     |  X  |
+  +-------+-----+-----+-----+-----+-----+
+  | 1110  |  14 |  X  |  X  |  X  |     |
+  +-------+-----+-----+-----+-----+-----+
+  | 1111  |  15 |  X  |  X  |  X  |  X  |
+  +-------+-----+-----+-----+-----+-----+
+
+  In most cases, the appropriate displays must be plugged in for the above
+  combinations to work. TV-Out may need to be initialized at boot time.
+
+  Debugging:
+
+  1) Check whether the Fn+F8 key:
+
+     a) does not lock the laptop (try a boot with noapic / nolapic if it does)
+     b) generates events (0x6n, where n is the value corresponding to the
+        configuration above)
+     c) actually works
+
+     Record the disp value at every configuration.
+  2) Echo values from 0 to 15 to /sys/devices/platform/asus-laptop/display.
+     Record its value, note any change. If nothing changes, try a broader range,
+     up to 65535.
+  3) Send ANY output (both positive and negative reports are needed, unless your
+     machine is already listed above) to the acpi4asus-user mailing list.
+
+  Note: on some machines (e.g. L3C), after the module has been loaded, only 0x6n
+  events are generated and no actual switching occurs. In such a case, a line
+  like::
+
+    echo $((10#$arg-60)) > /sys/devices/platform/asus-laptop/display
+
+  will usually do the trick ($arg is the 0000006n-like event passed to acpid).
+
+  Note: there is currently no reliable way to read display status on xxN
+  (Centrino) models.
+
+LED display
+-----------
+
+  Some models like the W1N have a LED display that can be used to display
+  several items of information.
+
+  LED display works for the following models:
+
+    - W1000N
+    - W1J
+
+  To control the LED display, use the following::
+
+    echo 0x0T000DDD > /sys/devices/platform/asus-laptop/
+
+  where T control the 3 letters display, and DDD the 3 digits display,
+  according to the tables below::
+
+         DDD (digits)
+         000 to 999 = display digits
+         AAA        = ---
+         BBB to FFF = turn-off
+
+         T  (type)
+         0 = off
+         1 = dvd
+         2 = vcd
+         3 = mp3
+         4 = cd
+         5 = tv
+         6 = cpu
+         7 = vol
+
+  For example "echo 0x01000001 >/sys/devices/platform/asus-laptop/ledd"
+  would display "DVD001".
+
+Driver options
+--------------
+
+ Options can be passed to the asus-laptop driver using the standard
+ module argument syntax (<param>=<value> when passing the option to the
+ module or asus-laptop.<param>=<value> on the kernel boot line when
+ asus-laptop is statically linked into the kernel).
+
+	     wapf: WAPF defines the behavior of the Fn+Fx wlan key
+		   The significance of values is yet to be found, but
+		   most of the time:
+
+		   - 0x0 should do nothing
+		   - 0x1 should allow to control the device with Fn+Fx key.
+		   - 0x4 should send an ACPI event (0x88) while pressing the Fn+Fx key
+		   - 0x5 like 0x1 or 0x4
+
+ The default value is 0x1.
+
+Unsupported models
+------------------
+
+ These models will never be supported by this module, as they use a completely
+ different mechanism to handle LEDs and extra stuff (meaning we have no clue
+ how it works):
+
+ - ASUS A1300 (A1B), A1370D
+ - ASUS L7300G
+ - ASUS L8400
+
+Patches, Errors, Questions
+--------------------------
+
+ 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:
+
+ - Asus model name
+ - a copy of your ACPI tables, using the "acpidump" utility
+ - a copy of /sys/devices/platform/asus-laptop/infos
+ - 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.
+
+ acpi4asus-user@lists.sourceforge.net
+
+ http://sourceforge.net/projects/acpi4asus
diff --git a/Documentation/admin-guide/laptops/disk-shock-protection.rst b/Documentation/admin-guide/laptops/disk-shock-protection.rst
new file mode 100644
index 000000000..22c7ec3e8
--- /dev/null
+++ b/Documentation/admin-guide/laptops/disk-shock-protection.rst
@@ -0,0 +1,151 @@
+==========================
+Hard disk shock protection
+==========================
+
+Author: Elias Oltmanns <eo@nebensachen.de>
+
+Last modified: 2008-10-03
+
+
+.. 0. Contents
+
+   1. Intro
+   2. The interface
+   3. References
+   4. CREDITS
+
+
+1. Intro
+--------
+
+ATA/ATAPI-7 specifies the IDLE IMMEDIATE command with unload feature.
+Issuing this command should cause the drive to switch to idle mode and
+unload disk heads. This feature is being used in modern laptops in
+conjunction with accelerometers and appropriate software to implement
+a shock protection facility. The idea is to stop all I/O operations on
+the internal hard drive and park its heads on the ramp when critical
+situations are anticipated. The desire to have such a feature
+available on GNU/Linux systems has been the original motivation to
+implement a generic disk head parking interface in the Linux kernel.
+Please note, however, that other components have to be set up on your
+system in order to get disk shock protection working (see
+section 3. References below for pointers to more information about
+that).
+
+
+2. The interface
+----------------
+
+For each ATA device, the kernel exports the file
+`block/*/device/unload_heads` in sysfs (here assumed to be mounted under
+/sys). Access to `/sys/block/*/device/unload_heads` is denied with
+-EOPNOTSUPP if the device does not support the unload feature.
+Otherwise, writing an integer value to this file will take the heads
+of the respective drive off the platter and block all I/O operations
+for the specified number of milliseconds. When the timeout expires and
+no further disk head park request has been issued in the meantime,
+normal operation will be resumed. The maximal value accepted for a
+timeout is 30000 milliseconds. Exceeding this limit will return
+-EOVERFLOW, but heads will be parked anyway and the timeout will be
+set to 30 seconds. However, you can always change a timeout to any
+value between 0 and 30000 by issuing a subsequent head park request
+before the timeout of the previous one has expired. In particular, the
+total timeout can exceed 30 seconds and, more importantly, you can
+cancel a previously set timeout and resume normal operation
+immediately by specifying a timeout of 0. Values below -2 are rejected
+with -EINVAL (see below for the special meaning of -1 and -2). If the
+timeout specified for a recent head park request has not yet expired,
+reading from `/sys/block/*/device/unload_heads` will report the number
+of milliseconds remaining until normal operation will be resumed;
+otherwise, reading the unload_heads attribute will return 0.
+
+For example, do the following in order to park the heads of drive
+/dev/sda and stop all I/O operations for five seconds::
+
+	# echo 5000 > /sys/block/sda/device/unload_heads
+
+A simple::
+
+	# cat /sys/block/sda/device/unload_heads
+
+will show you how many milliseconds are left before normal operation
+will be resumed.
+
+A word of caution: The fact that the interface operates on a basis of
+milliseconds may raise expectations that cannot be satisfied in
+reality. In fact, the ATA specs clearly state that the time for an
+unload operation to complete is vendor specific. The hint in ATA-7
+that this will typically be within 500 milliseconds apparently has
+been dropped in ATA-8.
+
+There is a technical detail of this implementation that may cause some
+confusion and should be discussed here. When a head park request has
+been issued to a device successfully, all I/O operations on the
+controller port this device is attached to will be deferred. That is
+to say, any other device that may be connected to the same port will
+be affected too. The only exception is that a subsequent head unload
+request to that other device will be executed immediately. Further
+operations on that port will be deferred until the timeout specified
+for either device on the port has expired. As far as PATA (old style
+IDE) configurations are concerned, there can only be two devices
+attached to any single port. In SATA world we have port multipliers
+which means that a user-issued head parking request to one device may
+actually result in stopping I/O to a whole bunch of devices. However,
+since this feature is supposed to be used on laptops and does not seem
+to be very useful in any other environment, there will be mostly one
+device per port. Even if the CD/DVD writer happens to be connected to
+the same port as the hard drive, it generally *should* recover just
+fine from the occasional buffer under-run incurred by a head park
+request to the HD. Actually, when you are using an ide driver rather
+than its libata counterpart (i.e. your disk is called /dev/hda
+instead of /dev/sda), then parking the heads of one drive (drive X)
+will generally not affect the mode of operation of another drive
+(drive Y) on the same port as described above. It is only when a port
+reset is required to recover from an exception on drive Y that further
+I/O operations on that drive (and the reset itself) will be delayed
+until drive X is no longer in the parked state.
+
+Finally, there are some hard drives that only comply with an earlier
+version of the ATA standard than ATA-7, but do support the unload
+feature nonetheless. Unfortunately, there is no safe way Linux can
+detect these devices, so you won't be able to write to the
+unload_heads attribute. If you know that your device really does
+support the unload feature (for instance, because the vendor of your
+laptop or the hard drive itself told you so), then you can tell the
+kernel to enable the usage of this feature for that drive by writing
+the special value -1 to the unload_heads attribute::
+
+	# echo -1 > /sys/block/sda/device/unload_heads
+
+will enable the feature for /dev/sda, and giving -2 instead of -1 will
+disable it again.
+
+
+3. References
+-------------
+
+There are several laptops from different vendors featuring shock
+protection capabilities. As manufacturers have refused to support open
+source development of the required software components so far, Linux
+support for shock protection varies considerably between different
+hardware implementations. Ideally, this section should contain a list
+of pointers at different projects aiming at an implementation of shock
+protection on different systems. Unfortunately, I only know of a
+single project which, although still considered experimental, is fit
+for use. Please feel free to add projects that have been the victims
+of my ignorance.
+
+- https://www.thinkwiki.org/wiki/HDAPS
+
+  See this page for information about Linux support of the hard disk
+  active protection system as implemented in IBM/Lenovo Thinkpads.
+
+
+4. CREDITS
+----------
+
+This implementation of disk head parking has been inspired by a patch
+originally published by Jon Escombe <lists@dresco.co.uk>. My efforts
+to develop an implementation of this feature that is fit to be merged
+into mainline have been aided by various kernel developers, in
+particular by Tejun Heo and Bartlomiej Zolnierkiewicz.
diff --git a/Documentation/admin-guide/laptops/index.rst b/Documentation/admin-guide/laptops/index.rst
new file mode 100644
index 000000000..cd9a1c269
--- /dev/null
+++ b/Documentation/admin-guide/laptops/index.rst
@@ -0,0 +1,17 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+Laptop Drivers
+==============
+
+.. toctree::
+   :maxdepth: 1
+
+   asus-laptop
+   disk-shock-protection
+   laptop-mode
+   lg-laptop
+   sony-laptop
+   sonypi
+   thinkpad-acpi
+   toshiba_haps
diff --git a/Documentation/admin-guide/laptops/laptop-mode.rst b/Documentation/admin-guide/laptops/laptop-mode.rst
new file mode 100644
index 000000000..b61cc601d
--- /dev/null
+++ b/Documentation/admin-guide/laptops/laptop-mode.rst
@@ -0,0 +1,770 @@
+===============================================
+How to conserve battery power using laptop-mode
+===============================================
+
+Document Author: Bart Samwel (bart@samwel.tk)
+
+Date created: January 2, 2004
+
+Last modified: December 06, 2004
+
+Introduction
+------------
+
+Laptop mode is used to minimize the time that the hard disk needs to be spun up,
+to conserve battery power on laptops. It has been reported to cause significant
+power savings.
+
+.. Contents
+
+   * Introduction
+   * Installation
+   * Caveats
+   * The Details
+   * Tips & Tricks
+   * Control script
+   * ACPI integration
+   * Monitoring tool
+
+
+Installation
+------------
+
+To use laptop mode, you don't need to set any kernel configuration options
+or anything. Simply install all the files included in this document, and
+laptop mode will automatically be started when you're on battery. For
+your convenience, a tarball containing an installer can be downloaded at:
+
+	http://www.samwel.tk/laptop_mode/laptop_mode/
+
+To configure laptop mode, you need to edit the configuration file, which is
+located in /etc/default/laptop-mode on Debian-based systems, or in
+/etc/sysconfig/laptop-mode on other systems.
+
+Unfortunately, automatic enabling of laptop mode does not work for
+laptops that don't have ACPI. On those laptops, you need to start laptop
+mode manually. To start laptop mode, run "laptop_mode start", and to
+stop it, run "laptop_mode stop". (Note: The laptop mode tools package now
+has experimental support for APM, you might want to try that first.)
+
+
+Caveats
+-------
+
+* The downside of laptop mode is that you have a chance of losing up to 10
+  minutes of work. If you cannot afford this, don't use it! The supplied ACPI
+  scripts automatically turn off laptop mode when the battery almost runs out,
+  so that you won't lose any data at the end of your battery life.
+
+* Most desktop hard drives have a very limited lifetime measured in spindown
+  cycles, typically about 50.000 times (it's usually listed on the spec sheet).
+  Check your drive's rating, and don't wear down your drive's lifetime if you
+  don't need to.
+
+* If you mount some of your ext3/reiserfs filesystems with the -n option, then
+  the control script will not be able to remount them correctly. You must set
+  DO_REMOUNTS=0 in the control script, otherwise it will remount them with the
+  wrong options -- or it will fail because it cannot write to /etc/mtab.
+
+* If you have your filesystems listed as type "auto" in fstab, like I did, then
+  the control script will not recognize them as filesystems that need remounting.
+  You must list the filesystems with their true type instead.
+
+* It has been reported that some versions of the mutt mail client use file access
+  times to determine whether a folder contains new mail. If you use mutt and
+  experience this, you must disable the noatime remounting by setting the option
+  DO_REMOUNT_NOATIME to 0 in the configuration file.
+
+
+The Details
+-----------
+
+Laptop mode is controlled by the knob /proc/sys/vm/laptop_mode. This knob is
+present for all kernels that have the laptop mode patch, regardless of any
+configuration options. When the knob is set, any physical disk I/O (that might
+have caused the hard disk to spin up) causes Linux to flush all dirty blocks. The
+result of this is that after a disk has spun down, it will not be spun up
+anymore to write dirty blocks, because those blocks had already been written
+immediately after the most recent read operation. The value of the laptop_mode
+knob determines the time between the occurrence of disk I/O and when the flush
+is triggered. A sensible value for the knob is 5 seconds. Setting the knob to
+0 disables laptop mode.
+
+To increase the effectiveness of the laptop_mode strategy, the laptop_mode
+control script increases dirty_expire_centisecs and dirty_writeback_centisecs in
+/proc/sys/vm to about 10 minutes (by default), which means that pages that are
+dirtied are not forced to be written to disk as often. The control script also
+changes the dirty background ratio, so that background writeback of dirty pages
+is not done anymore. Combined with a higher commit value (also 10 minutes) for
+ext3 or ReiserFS filesystems (also done automatically by the control script),
+this results in concentration of disk activity in a small time interval which
+occurs only once every 10 minutes, or whenever the disk is forced to spin up by
+a cache miss. The disk can then be spun down in the periods of inactivity.
+
+
+Configuration
+-------------
+
+The laptop mode configuration file is located in /etc/default/laptop-mode on
+Debian-based systems, or in /etc/sysconfig/laptop-mode on other systems. It
+contains the following options:
+
+MAX_AGE:
+
+Maximum time, in seconds, of hard drive spindown time that you are
+comfortable with. Worst case, it's possible that you could lose this
+amount of work if your battery fails while you're in laptop mode.
+
+MINIMUM_BATTERY_MINUTES:
+
+Automatically disable laptop mode if the remaining number of minutes of
+battery power is less than this value. Default is 10 minutes.
+
+AC_HD/BATT_HD:
+
+The idle timeout that should be set on your hard drive when laptop mode
+is active (BATT_HD) and when it is not active (AC_HD). The defaults are
+20 seconds (value 4) for BATT_HD  and 2 hours (value 244) for AC_HD. The
+possible values are those listed in the manual page for "hdparm" for the
+"-S" option.
+
+HD:
+
+The devices for which the spindown timeout should be adjusted by laptop mode.
+Default is /dev/hda. If you specify multiple devices, separate them by a space.
+
+READAHEAD:
+
+Disk readahead, in 512-byte sectors, while laptop mode is active. A large
+readahead can prevent disk accesses for things like executable pages (which are
+loaded on demand while the application executes) and sequentially accessed data
+(MP3s).
+
+DO_REMOUNTS:
+
+The control script automatically remounts any mounted journaled filesystems
+with appropriate commit interval options. When this option is set to 0, this
+feature is disabled.
+
+DO_REMOUNT_NOATIME:
+
+When remounting, should the filesystems be remounted with the noatime option?
+Normally, this is set to "1" (enabled), but there may be programs that require
+access time recording.
+
+DIRTY_RATIO:
+
+The percentage of memory that is allowed to contain "dirty" or unsaved data
+before a writeback is forced, while laptop mode is active. Corresponds to
+the /proc/sys/vm/dirty_ratio sysctl.
+
+DIRTY_BACKGROUND_RATIO:
+
+The percentage of memory that is allowed to contain "dirty" or unsaved data
+after a forced writeback is done due to an exceeding of DIRTY_RATIO. Set
+this nice and low. This corresponds to the /proc/sys/vm/dirty_background_ratio
+sysctl.
+
+Note that the behaviour of dirty_background_ratio is quite different
+when laptop mode is active and when it isn't. When laptop mode is inactive,
+dirty_background_ratio is the threshold percentage at which background writeouts
+start taking place. When laptop mode is active, however, background writeouts
+are disabled, and the dirty_background_ratio only determines how much writeback
+is done when dirty_ratio is reached.
+
+DO_CPU:
+
+Enable CPU frequency scaling when in laptop mode. (Requires CPUFreq to be setup.
+See Documentation/admin-guide/pm/cpufreq.rst for more info. Disabled by default.)
+
+CPU_MAXFREQ:
+
+When on battery, what is the maximum CPU speed that the system should use? Legal
+values are "slowest" for the slowest speed that your CPU is able to operate at,
+or a value listed in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies.
+
+
+Tips & Tricks
+-------------
+
+* Bartek Kania reports getting up to 50 minutes of extra battery life (on top
+  of his regular 3 to 3.5 hours) using a spindown time of 5 seconds (BATT_HD=1).
+
+* You can spin down the disk while playing MP3, by setting disk readahead
+  to 8MB (READAHEAD=16384). Effectively, the disk will read a complete MP3 at
+  once, and will then spin down while the MP3 is playing. (Thanks to Bartek
+  Kania.)
+
+* Drew Scott Daniels observed: "I don't know why, but when I decrease the number
+  of colours that my display uses it consumes less battery power. I've seen
+  this on powerbooks too. I hope that this is a piece of information that
+  might be useful to the Laptop Mode patch or its users."
+
+* In syslog.conf, you can prefix entries with a dash `-` to omit syncing the
+  file after every logging. When you're using laptop-mode and your disk doesn't
+  spin down, this is a likely culprit.
+
+* Richard Atterer observed that laptop mode does not work well with noflushd
+  (http://noflushd.sourceforge.net/), it seems that noflushd prevents laptop-mode
+  from doing its thing.
+
+* If you're worried about your data, you might want to consider using a USB
+  memory stick or something like that as a "working area". (Be aware though
+  that flash memory can only handle a limited number of writes, and overuse
+  may wear out your memory stick pretty quickly. Do _not_ use journalling
+  filesystems on flash memory sticks.)
+
+
+Configuration file for control and ACPI battery scripts
+-------------------------------------------------------
+
+This allows the tunables to be changed for the scripts via an external
+configuration file
+
+It should be installed as /etc/default/laptop-mode on Debian, and as
+/etc/sysconfig/laptop-mode on Red Hat, SUSE, Mandrake, and other work-alikes.
+
+Config file::
+
+  # Maximum time, in seconds, of hard drive spindown time that you are
+  # comfortable with. Worst case, it's possible that you could lose this
+  # amount of work if your battery fails you while in laptop mode.
+  #MAX_AGE=600
+
+  # Automatically disable laptop mode when the number of minutes of battery
+  # that you have left goes below this threshold.
+  MINIMUM_BATTERY_MINUTES=10
+
+  # Read-ahead, in 512-byte sectors. You can spin down the disk while playing MP3/OGG
+  # by setting the disk readahead to 8MB (READAHEAD=16384). Effectively, the disk
+  # will read a complete MP3 at once, and will then spin down while the MP3/OGG is
+  # playing.
+  #READAHEAD=4096
+
+  # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
+  #DO_REMOUNTS=1
+
+  # And shall we add the "noatime" option to that as well? (1=yes)
+  #DO_REMOUNT_NOATIME=1
+
+  # Dirty synchronous ratio.  At this percentage of dirty pages the process
+  # which
+  # calls write() does its own writeback
+  #DIRTY_RATIO=40
+
+  #
+  # Allowed dirty background ratio, in percent.  Once DIRTY_RATIO has been
+  # exceeded, the kernel will wake flusher threads which will then reduce the
+  # amount of dirty memory to dirty_background_ratio.  Set this nice and low,
+  # so once some writeout has commenced, we do a lot of it.
+  #
+  #DIRTY_BACKGROUND_RATIO=5
+
+  # kernel default dirty buffer age
+  #DEF_AGE=30
+  #DEF_UPDATE=5
+  #DEF_DIRTY_BACKGROUND_RATIO=10
+  #DEF_DIRTY_RATIO=40
+  #DEF_XFS_AGE_BUFFER=15
+  #DEF_XFS_SYNC_INTERVAL=30
+  #DEF_XFS_BUFD_INTERVAL=1
+
+  # This must be adjusted manually to the value of HZ in the running kernel
+  # on 2.4, until the XFS people change their 2.4 external interfaces to work in
+  # centisecs. This can be automated, but it's a work in progress that still
+  # needs# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for
+  # external interfaces, and that is currently always set to 100. So you don't
+  # need to change this on 2.6.
+  #XFS_HZ=100
+
+  # Should the maximum CPU frequency be adjusted down while on battery?
+  # Requires CPUFreq to be setup.
+  # See Documentation/admin-guide/pm/cpufreq.rst for more info
+  #DO_CPU=0
+
+  # When on battery what is the maximum CPU speed that the system should
+  # use? Legal values are "slowest" for the slowest speed that your
+  # CPU is able to operate at, or a value listed in:
+  # /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
+  # Only applicable if DO_CPU=1.
+  #CPU_MAXFREQ=slowest
+
+  # Idle timeout for your hard drive (man hdparm for valid values, -S option)
+  # Default is 2 hours on AC (AC_HD=244) and 20 seconds for battery (BATT_HD=4).
+  #AC_HD=244
+  #BATT_HD=4
+
+  # The drives for which to adjust the idle timeout. Separate them by a space,
+  # e.g. HD="/dev/hda /dev/hdb".
+  #HD="/dev/hda"
+
+  # Set the spindown timeout on a hard drive?
+  #DO_HD=1
+
+
+Control script
+--------------
+
+Please note that this control script works for the Linux 2.4 and 2.6 series (thanks
+to Kiko Piris).
+
+Control script::
+
+  #!/bin/bash
+
+  # start or stop laptop_mode, best run by a power management daemon when
+  # ac gets connected/disconnected from a laptop
+  #
+  # install as /sbin/laptop_mode
+  #
+  # Contributors to this script:   Kiko Piris
+  #				 Bart Samwel
+  #				 Micha Feigin
+  #				 Andrew Morton
+  #				 Herve Eychenne
+  #				 Dax Kelson
+  #
+  # Original Linux 2.4 version by: Jens Axboe
+
+  #############################################################################
+
+  # Source config
+  if [ -f /etc/default/laptop-mode ] ; then
+	# Debian
+	. /etc/default/laptop-mode
+  elif [ -f /etc/sysconfig/laptop-mode ] ; then
+	# Others
+          . /etc/sysconfig/laptop-mode
+  fi
+
+  # Don't raise an error if the config file is incomplete
+  # set defaults instead:
+
+  # Maximum time, in seconds, of hard drive spindown time that you are
+  # comfortable with. Worst case, it's possible that you could lose this
+  # amount of work if your battery fails you while in laptop mode.
+  MAX_AGE=${MAX_AGE:-'600'}
+
+  # Read-ahead, in kilobytes
+  READAHEAD=${READAHEAD:-'4096'}
+
+  # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
+  DO_REMOUNTS=${DO_REMOUNTS:-'1'}
+
+  # And shall we add the "noatime" option to that as well? (1=yes)
+  DO_REMOUNT_NOATIME=${DO_REMOUNT_NOATIME:-'1'}
+
+  # Shall we adjust the idle timeout on a hard drive?
+  DO_HD=${DO_HD:-'1'}
+
+  # Adjust idle timeout on which hard drive?
+  HD="${HD:-'/dev/hda'}"
+
+  # spindown time for HD (hdparm -S values)
+  AC_HD=${AC_HD:-'244'}
+  BATT_HD=${BATT_HD:-'4'}
+
+  # Dirty synchronous ratio.  At this percentage of dirty pages the process which
+  # calls write() does its own writeback
+  DIRTY_RATIO=${DIRTY_RATIO:-'40'}
+
+  # cpu frequency scaling
+  # See Documentation/admin-guide/pm/cpufreq.rst for more info
+  DO_CPU=${CPU_MANAGE:-'0'}
+  CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'}
+
+  #
+  # Allowed dirty background ratio, in percent.  Once DIRTY_RATIO has been
+  # exceeded, the kernel will wake flusher threads which will then reduce the
+  # amount of dirty memory to dirty_background_ratio.  Set this nice and low,
+  # so once some writeout has commenced, we do a lot of it.
+  #
+  DIRTY_BACKGROUND_RATIO=${DIRTY_BACKGROUND_RATIO:-'5'}
+
+  # kernel default dirty buffer age
+  DEF_AGE=${DEF_AGE:-'30'}
+  DEF_UPDATE=${DEF_UPDATE:-'5'}
+  DEF_DIRTY_BACKGROUND_RATIO=${DEF_DIRTY_BACKGROUND_RATIO:-'10'}
+  DEF_DIRTY_RATIO=${DEF_DIRTY_RATIO:-'40'}
+  DEF_XFS_AGE_BUFFER=${DEF_XFS_AGE_BUFFER:-'15'}
+  DEF_XFS_SYNC_INTERVAL=${DEF_XFS_SYNC_INTERVAL:-'30'}
+  DEF_XFS_BUFD_INTERVAL=${DEF_XFS_BUFD_INTERVAL:-'1'}
+
+  # This must be adjusted manually to the value of HZ in the running kernel
+  # on 2.4, until the XFS people change their 2.4 external interfaces to work in
+  # centisecs. This can be automated, but it's a work in progress that still needs
+  # some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external
+  # interfaces, and that is currently always set to 100. So you don't need to
+  # change this on 2.6.
+  XFS_HZ=${XFS_HZ:-'100'}
+
+  #############################################################################
+
+  KLEVEL="$(uname -r |
+               {
+	       IFS='.' read a b c
+	       echo $a.$b
+	     }
+  )"
+  case "$KLEVEL" in
+	"2.4"|"2.6")
+		;;
+	*)
+		echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2
+		exit 1
+		;;
+  esac
+
+  if [ ! -e /proc/sys/vm/laptop_mode ] ; then
+	echo "Kernel is not patched with laptop_mode patch." >&2
+	exit 1
+  fi
+
+  if [ ! -w /proc/sys/vm/laptop_mode ] ; then
+	echo "You do not have enough privileges to enable laptop_mode." >&2
+	exit 1
+  fi
+
+  # Remove an option (the first parameter) of the form option=<number> from
+  # a mount options string (the rest of the parameters).
+  parse_mount_opts () {
+	OPT="$1"
+	shift
+	echo ",$*," | sed		\
+	 -e 's/,'"$OPT"'=[0-9]*,/,/g'	\
+	 -e 's/,,*/,/g'			\
+	 -e 's/^,//'			\
+	 -e 's/,$//'
+  }
+
+  # Remove an option (the first parameter) without any arguments from
+  # a mount option string (the rest of the parameters).
+  parse_nonumber_mount_opts () {
+	OPT="$1"
+	shift
+	echo ",$*," | sed		\
+	 -e 's/,'"$OPT"',/,/g'		\
+	 -e 's/,,*/,/g'			\
+	 -e 's/^,//'			\
+	 -e 's/,$//'
+  }
+
+  # Find out the state of a yes/no option (e.g. "atime"/"noatime") in
+  # fstab for a given filesystem, and use this state to replace the
+  # value of the option in another mount options string. The device
+  # is the first argument, the option name the second, and the default
+  # value the third. The remainder is the mount options string.
+  #
+  # Example:
+  # parse_yesno_opts_wfstab /dev/hda1 atime atime defaults,noatime
+  #
+  # If fstab contains, say, "rw" for this filesystem, then the result
+  # will be "defaults,atime".
+  parse_yesno_opts_wfstab () {
+	L_DEV="$1"
+	OPT="$2"
+	DEF_OPT="$3"
+	shift 3
+	L_OPTS="$*"
+	PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
+	PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
+	# Watch for a default atime in fstab
+	FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
+	if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then
+		# option specified in fstab: extract the value and use it
+		if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then
+			echo "$PARSEDOPTS1,no$OPT"
+		else
+			# no$OPT not found -- so we must have $OPT.
+			echo "$PARSEDOPTS1,$OPT"
+		fi
+	else
+		# option not specified in fstab -- choose the default.
+		echo "$PARSEDOPTS1,$DEF_OPT"
+	fi
+  }
+
+  # Find out the state of a numbered option (e.g. "commit=NNN") in
+  # fstab for a given filesystem, and use this state to replace the
+  # value of the option in another mount options string. The device
+  # is the first argument, and the option name the second. The
+  # remainder is the mount options string in which the replacement
+  # must be done.
+  #
+  # Example:
+  # parse_mount_opts_wfstab /dev/hda1 commit defaults,commit=7
+  #
+  # If fstab contains, say, "commit=3,rw" for this filesystem, then the
+  # result will be "rw,commit=3".
+  parse_mount_opts_wfstab () {
+	L_DEV="$1"
+	OPT="$2"
+	shift 2
+	L_OPTS="$*"
+	PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
+	# Watch for a default commit in fstab
+	FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
+	if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then
+		# option specified in fstab: extract the value, and use it
+		echo -n "$PARSEDOPTS1,$OPT="
+		echo ",$FSTAB_OPTS," | sed \
+		 -e 's/.*,'"$OPT"'=//'	\
+		 -e 's/,.*//'
+	else
+		# option not specified in fstab: set it to 0
+		echo "$PARSEDOPTS1,$OPT=0"
+	fi
+  }
+
+  deduce_fstype () {
+	MP="$1"
+	# My root filesystem unfortunately has
+	# type "unknown" in /etc/mtab. If we encounter
+	# "unknown", we try to get the type from fstab.
+	cat /etc/fstab |
+	grep -v '^#' |
+	while read FSTAB_DEV FSTAB_MP FSTAB_FST FSTAB_OPTS FSTAB_DUMP FSTAB_DUMP ; do
+		if [ "$FSTAB_MP" = "$MP" ]; then
+			echo $FSTAB_FST
+			exit 0
+		fi
+	done
+  }
+
+  if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then
+	NOATIME_OPT=",noatime"
+  fi
+
+  case "$1" in
+	start)
+		AGE=$((100*$MAX_AGE))
+		XFS_AGE=$(($XFS_HZ*$MAX_AGE))
+		echo -n "Starting laptop_mode"
+
+		if [ -d /proc/sys/vm/pagebuf ] ; then
+			# (For 2.4 and early 2.6.)
+			# This only needs to be set, not reset -- it is only used when
+			# laptop mode is enabled.
+			echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age
+			echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
+		elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
+			# (A couple of early 2.6 laptop mode patches had these.)
+			# The same goes for these.
+			echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer
+			echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
+		elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then
+			# (2.6.6)
+			# But not for these -- they are also used in normal
+			# operation.
+			echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer
+			echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval
+		elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
+			# (2.6.7 upwards)
+			# And not for these either. These are in centisecs,
+			# not USER_HZ, so we have to use $AGE, not $XFS_AGE.
+			echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs
+			echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs
+			echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs
+		fi
+
+		case "$KLEVEL" in
+			"2.4")
+				echo 1					> /proc/sys/vm/laptop_mode
+				echo "30 500 0 0 $AGE $AGE 60 20 0"	> /proc/sys/vm/bdflush
+				;;
+			"2.6")
+				echo 5					> /proc/sys/vm/laptop_mode
+				echo "$AGE"				> /proc/sys/vm/dirty_writeback_centisecs
+				echo "$AGE"				> /proc/sys/vm/dirty_expire_centisecs
+				echo "$DIRTY_RATIO"			> /proc/sys/vm/dirty_ratio
+				echo "$DIRTY_BACKGROUND_RATIO"		> /proc/sys/vm/dirty_background_ratio
+				;;
+		esac
+		if [ $DO_REMOUNTS -eq 1 ]; then
+			cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
+				PARSEDOPTS="$(parse_mount_opts "$OPTS")"
+				if [ "$FST" = 'unknown' ]; then
+					FST=$(deduce_fstype $MP)
+				fi
+				case "$FST" in
+					"ext3"|"reiserfs")
+						PARSEDOPTS="$(parse_mount_opts commit "$OPTS")"
+						mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT
+						;;
+					"xfs")
+						mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT
+						;;
+				esac
+				if [ -b $DEV ] ; then
+					blockdev --setra $(($READAHEAD * 2)) $DEV
+				fi
+			done
+		fi
+		if [ $DO_HD -eq 1 ] ; then
+			for THISHD in $HD ; do
+				/sbin/hdparm -S $BATT_HD $THISHD > /dev/null 2>&1
+				/sbin/hdparm -B 1 $THISHD > /dev/null 2>&1
+			done
+		fi
+		if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
+			if [ $CPU_MAXFREQ = 'slowest' ]; then
+				CPU_MAXFREQ=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq`
+			fi
+			echo $CPU_MAXFREQ > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
+		fi
+		echo "."
+		;;
+	stop)
+		U_AGE=$((100*$DEF_UPDATE))
+		B_AGE=$((100*$DEF_AGE))
+		echo -n "Stopping laptop_mode"
+		echo 0 > /proc/sys/vm/laptop_mode
+		if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
+			# These need to be restored, if there are no lm_*.
+			echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER))	 	> /proc/sys/fs/xfs/age_buffer
+			echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) 	> /proc/sys/fs/xfs/sync_interval
+		elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
+			# These need to be restored as well.
+			echo $((100*$DEF_XFS_AGE_BUFFER))	> /proc/sys/fs/xfs/age_buffer_centisecs
+			echo $((100*$DEF_XFS_SYNC_INTERVAL))	> /proc/sys/fs/xfs/xfssyncd_centisecs
+			echo $((100*$DEF_XFS_BUFD_INTERVAL))	> /proc/sys/fs/xfs/xfsbufd_centisecs
+		fi
+		case "$KLEVEL" in
+			"2.4")
+				echo "30 500 0 0 $U_AGE $B_AGE 60 20 0"	> /proc/sys/vm/bdflush
+				;;
+			"2.6")
+				echo "$U_AGE"				> /proc/sys/vm/dirty_writeback_centisecs
+				echo "$B_AGE"				> /proc/sys/vm/dirty_expire_centisecs
+				echo "$DEF_DIRTY_RATIO"			> /proc/sys/vm/dirty_ratio
+				echo "$DEF_DIRTY_BACKGROUND_RATIO"	> /proc/sys/vm/dirty_background_ratio
+				;;
+		esac
+		if [ $DO_REMOUNTS -eq 1 ] ; then
+			cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
+				# Reset commit and atime options to defaults.
+				if [ "$FST" = 'unknown' ]; then
+					FST=$(deduce_fstype $MP)
+				fi
+				case "$FST" in
+					"ext3"|"reiserfs")
+						PARSEDOPTS="$(parse_mount_opts_wfstab $DEV commit $OPTS)"
+						PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $PARSEDOPTS)"
+						mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
+						;;
+					"xfs")
+						PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $OPTS)"
+						mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
+						;;
+				esac
+				if [ -b $DEV ] ; then
+					blockdev --setra 256 $DEV
+				fi
+			done
+		fi
+		if [ $DO_HD -eq 1 ] ; then
+			for THISHD in $HD ; do
+				/sbin/hdparm -S $AC_HD $THISHD > /dev/null 2>&1
+				/sbin/hdparm -B 255 $THISHD > /dev/null 2>&1
+			done
+		fi
+		if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
+			echo `cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq` > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
+		fi
+		echo "."
+		;;
+	*)
+		echo "Usage: $0 {start|stop}" 2>&1
+		exit 1
+		;;
+
+  esac
+
+  exit 0
+
+
+ACPI integration
+----------------
+
+Dax Kelson submitted this so that the ACPI acpid daemon will
+kick off the laptop_mode script and run hdparm. The part that
+automatically disables laptop mode when the battery is low was
+written by Jan Topinski.
+
+/etc/acpi/events/ac_adapter::
+
+	event=ac_adapter
+	action=/etc/acpi/actions/ac.sh %e
+
+/etc/acpi/events/battery::
+
+	event=battery.*
+	action=/etc/acpi/actions/battery.sh %e
+
+/etc/acpi/actions/ac.sh::
+
+  #!/bin/bash
+
+  # ac on/offline event handler
+
+  status=`awk '/^state: / { print $2 }' /proc/acpi/ac_adapter/$2/state`
+
+  case $status in
+          "on-line")
+                  /sbin/laptop_mode stop
+                  exit 0
+          ;;
+          "off-line")
+                  /sbin/laptop_mode start
+                  exit 0
+          ;;
+  esac
+
+
+/etc/acpi/actions/battery.sh::
+
+  #! /bin/bash
+
+  # Automatically disable laptop mode when the battery almost runs out.
+
+  BATT_INFO=/proc/acpi/battery/$2/state
+
+  if [[ -f /proc/sys/vm/laptop_mode ]]
+  then
+     LM=`cat /proc/sys/vm/laptop_mode`
+     if [[ $LM -gt 0 ]]
+     then
+       if [[ -f $BATT_INFO ]]
+       then
+          # Source the config file only now that we know we need
+          if [ -f /etc/default/laptop-mode ] ; then
+                  # Debian
+                  . /etc/default/laptop-mode
+          elif [ -f /etc/sysconfig/laptop-mode ] ; then
+                  # Others
+                  . /etc/sysconfig/laptop-mode
+          fi
+          MINIMUM_BATTERY_MINUTES=${MINIMUM_BATTERY_MINUTES:-'10'}
+
+          ACTION="`cat $BATT_INFO | grep charging | cut -c 26-`"
+          if [[ ACTION -eq "discharging" ]]
+          then
+             PRESENT_RATE=`cat $BATT_INFO | grep "present rate:" | sed  "s/.* \([0-9][0-9]* \).*/\1/" `
+             REMAINING=`cat $BATT_INFO | grep "remaining capacity:" | sed  "s/.* \([0-9][0-9]* \).*/\1/" `
+          fi
+          if (($REMAINING * 60 / $PRESENT_RATE < $MINIMUM_BATTERY_MINUTES))
+          then
+             /sbin/laptop_mode stop
+          fi
+       else
+         logger -p daemon.warning "You are using laptop mode and your battery interface $BATT_INFO is missing. This may lead to loss of data when the battery runs out. Check kernel ACPI support and /proc/acpi/battery folder, and edit /etc/acpi/battery.sh to set BATT_INFO to the correct path."
+       fi
+     fi
+  fi
+
+
+Monitoring tool
+---------------
+
+Bartek Kania submitted this, it can be used to measure how much time your disk
+spends spun up/down.  See tools/laptop/dslm/dslm.c
diff --git a/Documentation/admin-guide/laptops/lg-laptop.rst b/Documentation/admin-guide/laptops/lg-laptop.rst
new file mode 100644
index 000000000..67fd6932c
--- /dev/null
+++ b/Documentation/admin-guide/laptops/lg-laptop.rst
@@ -0,0 +1,82 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+
+LG Gram laptop extra features
+=============================
+
+By Matan Ziv-Av <matan@svgalib.org>
+
+
+Hotkeys
+-------
+
+The following FN keys are ignored by the kernel without this driver:
+
+- FN-F1 (LG control panel)   - Generates F15
+- FN-F5 (Touchpad toggle)    - Generates F21
+- FN-F6 (Airplane mode)      - Generates RFKILL
+- FN-F9 (Reader mode)        - Generates F14
+
+The rest of the FN keys work without a need for a special driver.
+
+
+Reader mode
+-----------
+
+Writing 0/1 to /sys/devices/platform/lg-laptop/reader_mode disables/enables
+reader mode. In this mode the screen colors change (blue color reduced),
+and the reader mode indicator LED (on F9 key) turns on.
+
+
+FN Lock
+-------
+
+Writing 0/1 to /sys/devices/platform/lg-laptop/fn_lock disables/enables
+FN lock.
+
+
+Battery care limit
+------------------
+
+Writing 80/100 to /sys/class/power_supply/CMB0/charge_control_end_threshold
+sets the maximum capacity to charge the battery. Limiting the charge
+reduces battery capacity loss over time.
+
+This value is reset to 100 when the kernel boots.
+
+
+Fan mode
+--------
+
+Writing 1/0 to /sys/devices/platform/lg-laptop/fan_mode disables/enables
+the fan silent mode.
+
+
+USB charge
+----------
+
+Writing 0/1 to /sys/devices/platform/lg-laptop/usb_charge disables/enables
+charging another device from the USB port while the device is turned off.
+
+This value is reset to 0 when the kernel boots.
+
+
+LEDs
+~~~~
+
+The are two LED devices supported by the driver:
+
+Keyboard backlight
+------------------
+
+A led device named kbd_led controls the keyboard backlight. There are three
+lighting level: off (0), low (127) and high (255).
+
+The keyboard backlight is also controlled by the key combination FN-F8
+which cycles through those levels.
+
+
+Touchpad indicator LED
+----------------------
+
+On the F5 key. Controlled by led device names tpad_led.
diff --git a/Documentation/admin-guide/laptops/sony-laptop.rst b/Documentation/admin-guide/laptops/sony-laptop.rst
new file mode 100644
index 000000000..9edcc7f66
--- /dev/null
+++ b/Documentation/admin-guide/laptops/sony-laptop.rst
@@ -0,0 +1,174 @@
+=========================================
+Sony Notebook Control Driver (SNC) Readme
+=========================================
+
+	- Copyright (C) 2004- 2005 Stelian Pop <stelian@popies.net>
+	- Copyright (C) 2007 Mattia Dongili <malattia@linux.it>
+
+This mini-driver drives the SNC and SPIC device present in the ACPI BIOS of the
+Sony Vaio laptops. This driver mixes both devices functions under the same
+(hopefully consistent) interface. This also means that the sonypi driver is
+obsoleted by sony-laptop now.
+
+Fn keys (hotkeys):
+------------------
+
+Some models report hotkeys through the SNC or SPIC devices, such events are
+reported both through the ACPI subsystem as acpi events and through the INPUT
+subsystem. See the logs of /proc/bus/input/devices to find out what those
+events are and which input devices are created by the driver.
+Additionally, loading the driver with the debug option will report all events
+in the kernel log.
+
+The "scancodes" passed to the input system (that can be remapped with udev)
+are indexes to the table "sony_laptop_input_keycode_map" in the sony-laptop.c
+module.  For example the "FN/E" key combination (EJECTCD on some models)
+generates the scancode 20 (0x14).
+
+Backlight control:
+------------------
+If your laptop model supports it, you will find sysfs files in the
+/sys/class/backlight/sony/
+directory. You will be able to query and set the current screen
+brightness:
+
+	======================	=========================================
+	brightness		get/set screen brightness (an integer
+				between 0 and 7)
+	actual_brightness	reading from this file will query the HW
+				to get real brightness value
+	max_brightness		the maximum brightness value
+	======================	=========================================
+
+
+Platform specific:
+------------------
+Loading the sony-laptop module will create a
+/sys/devices/platform/sony-laptop/
+directory populated with some files.
+
+You then read/write integer values from/to those files by using
+standard UNIX tools.
+
+The files are:
+
+	======================	==========================================
+	brightness_default	screen brightness which will be set
+				when the laptop will be rebooted
+	cdpower			power on/off the internal CD drive
+	audiopower		power on/off the internal sound card
+	lanpower		power on/off the internal ethernet card
+				(only in debug mode)
+	bluetoothpower		power on/off the internal bluetooth device
+	fanspeed		get/set the fan speed
+	======================	==========================================
+
+Note that some files may be missing if they are not supported
+by your particular laptop model.
+
+Example usage::
+
+	# echo "1" > /sys/devices/platform/sony-laptop/brightness_default
+
+sets the lowest screen brightness for the next and later reboots
+
+::
+
+	# echo "8" > /sys/devices/platform/sony-laptop/brightness_default
+
+sets the highest screen brightness for the next and later reboots
+
+::
+
+	# cat /sys/devices/platform/sony-laptop/brightness_default
+
+retrieves the value
+
+::
+
+	# echo "0" > /sys/devices/platform/sony-laptop/audiopower
+
+powers off the sound card
+
+::
+
+	# echo "1" > /sys/devices/platform/sony-laptop/audiopower
+
+powers on the sound card.
+
+
+RFkill control:
+---------------
+More recent Vaio models expose a consistent set of ACPI methods to
+control radio frequency emitting devices. If you are a lucky owner of
+such a laptop you will find the necessary rfkill devices under
+/sys/class/rfkill. Check those starting with sony-* in::
+
+	# grep . /sys/class/rfkill/*/{state,name}
+
+
+Development:
+------------
+
+If you want to help with the development of this driver (and
+you are not afraid of any side effects doing strange things with
+your ACPI BIOS could have on your laptop), load the driver and
+pass the option 'debug=1'.
+
+REPEAT:
+	**DON'T DO THIS IF YOU DON'T LIKE RISKY BUSINESS.**
+
+In your kernel logs you will find the list of all ACPI methods
+the SNC device has on your laptop.
+
+* For new models you will see a long list of meaningless method names,
+  reading the DSDT table source should reveal that:
+
+(1) the SNC device uses an internal capability lookup table
+(2) SN00 is used to find values in the lookup table
+(3) SN06 and SN07 are used to call into the real methods based on
+    offsets you can obtain iterating the table using SN00
+(4) SN02 used to enable events.
+
+Some values in the capability lookup table are more or less known, see
+the code for all sony_call_snc_handle calls, others are more obscure.
+
+* For old models you can see the GCDP/GCDP methods used to pwer on/off
+  the CD drive, but there are others and they are usually different from
+  model to model.
+
+**I HAVE NO IDEA WHAT THOSE METHODS DO.**
+
+The sony-laptop driver creates, for some of those methods (the most
+current ones found on several Vaio models), an entry under
+/sys/devices/platform/sony-laptop, just like the 'cdpower' one.
+You can create other entries corresponding to your own laptop methods by
+further editing the source (see the 'sony_nc_values' table, and add a new
+entry to this table with your get/set method names using the
+SNC_HANDLE_NAMES macro).
+
+Your mission, should you accept it, is to try finding out what
+those entries are for, by reading/writing random values from/to those
+files and find out what is the impact on your laptop.
+
+Should you find anything interesting, please report it back to me,
+I will not disavow all knowledge of your actions :)
+
+See also http://www.linux.it/~malattia/wiki/index.php/Sony_drivers for other
+useful info.
+
+Bugs/Limitations:
+-----------------
+
+* This driver is not based on official documentation from Sony
+  (because there is none), so there is no guarantee this driver
+  will work at all, or do the right thing. Although this hasn't
+  happened to me, this driver could do very bad things to your
+  laptop, including permanent damage.
+
+* The sony-laptop and sonypi drivers do not interact at all. In the
+  future, sonypi will be removed and replaced by sony-laptop.
+
+* spicctrl, which is the userspace tool used to communicate with the
+  sonypi driver (through /dev/sonypi) is deprecated as well since all
+  its features are now available under the sysfs tree via sony-laptop.
diff --git a/Documentation/admin-guide/laptops/sonypi.rst b/Documentation/admin-guide/laptops/sonypi.rst
new file mode 100644
index 000000000..190da1234
--- /dev/null
+++ b/Documentation/admin-guide/laptops/sonypi.rst
@@ -0,0 +1,158 @@
+==================================================
+Sony Programmable I/O Control Device Driver Readme
+==================================================
+
+	- Copyright (C) 2001-2004 Stelian Pop <stelian@popies.net>
+	- Copyright (C) 2001-2002 Alcôve <www.alcove.com>
+	- Copyright (C) 2001 Michael Ashley <m.ashley@unsw.edu.au>
+	- Copyright (C) 2001 Junichi Morita <jun1m@mars.dti.ne.jp>
+	- Copyright (C) 2000 Takaya Kinjo <t-kinjo@tc4.so-net.ne.jp>
+	- Copyright (C) 2000 Andrew Tridgell <tridge@samba.org>
+
+This driver enables access to the Sony Programmable I/O Control Device which
+can be found in many Sony Vaio laptops. Some newer Sony laptops (seems to be
+limited to new FX series laptops, at least the FX501 and the FX702) lack a
+sonypi device and are not supported at all by this driver.
+
+It will give access (through a user space utility) to some events those laptops
+generate, like:
+
+	- jogdial events (the small wheel on the side of Vaios)
+	- capture button events (only on Vaio Picturebook series)
+	- Fn keys
+	- bluetooth button (only on C1VR model)
+	- programmable keys, back, help, zoom, thumbphrase buttons, etc.
+	  (when available)
+
+Those events (see linux/sonypi.h) can be polled using the character device node
+/dev/sonypi (major 10, minor auto allocated or specified as a option).
+A simple daemon which translates the jogdial movements into mouse wheel events
+can be downloaded at: <http://popies.net/sonypi/>
+
+Another option to intercept the events is to get them directly through the
+input layer.
+
+This driver supports also some ioctl commands for setting the LCD screen
+brightness and querying the batteries charge information (some more
+commands may be added in the future).
+
+This driver can also be used to set the camera controls on Picturebook series
+(brightness, contrast etc), and is used by the video4linux driver for the
+Motion Eye camera.
+
+Please note that this driver was created by reverse engineering the Windows
+driver and the ACPI BIOS, because Sony doesn't agree to release any programming
+specs for its laptops. If someone convinces them to do so, drop me a note.
+
+Driver options:
+---------------
+
+Several options can be passed to the sonypi driver using the standard
+module argument syntax (<param>=<value> when passing the option to the
+module or sonypi.<param>=<value> on the kernel boot line when sonypi is
+statically linked into the kernel). Those options are:
+
+	=============== =======================================================
+	minor:		minor number of the misc device /dev/sonypi,
+			default is -1 (automatic allocation, see /proc/misc
+			or kernel logs)
+
+	camera:		if you have a PictureBook series Vaio (with the
+			integrated MotionEye camera), set this parameter to 1
+			in order to let the driver access to the camera
+
+	fnkeyinit:	on some Vaios (C1VE, C1VR etc), the Fn key events don't
+			get enabled unless you set this parameter to 1.
+			Do not use this option unless it's actually necessary,
+			some Vaio models don't deal well with this option.
+			This option is available only if the kernel is
+			compiled without ACPI support (since it conflicts
+			with it and it shouldn't be required anyway if
+			ACPI is already enabled).
+
+	verbose:	set to 1 to print unknown events received from the
+			sonypi device.
+			set to 2 to print all events received from the
+			sonypi device.
+
+	compat:		uses some compatibility code for enabling the sonypi
+			events. If the driver worked for you in the past
+			(prior to version 1.5) and does not work anymore,
+			add this option and report to the author.
+
+	mask:		event mask telling the driver what events will be
+			reported to the user. This parameter is required for
+			some Vaio models where the hardware reuses values
+			used in other Vaio models (like the FX series who does
+			not have a jogdial but reuses the jogdial events for
+			programmable keys events). The default event mask is
+			set to 0xffffffff, meaning that all possible events
+			will be tried. You can use the following bits to
+			construct your own event mask (from
+			drivers/char/sonypi.h)::
+
+				SONYPI_JOGGER_MASK		0x0001
+				SONYPI_CAPTURE_MASK		0x0002
+				SONYPI_FNKEY_MASK		0x0004
+				SONYPI_BLUETOOTH_MASK		0x0008
+				SONYPI_PKEY_MASK		0x0010
+				SONYPI_BACK_MASK		0x0020
+				SONYPI_HELP_MASK		0x0040
+				SONYPI_LID_MASK			0x0080
+				SONYPI_ZOOM_MASK		0x0100
+				SONYPI_THUMBPHRASE_MASK		0x0200
+				SONYPI_MEYE_MASK		0x0400
+				SONYPI_MEMORYSTICK_MASK		0x0800
+				SONYPI_BATTERY_MASK		0x1000
+				SONYPI_WIRELESS_MASK		0x2000
+
+	useinput:	if set (which is the default) two input devices are
+			created, one which interprets the jogdial events as
+			mouse events, the other one which acts like a
+			keyboard reporting the pressing of the special keys.
+	=============== =======================================================
+
+Module use:
+-----------
+
+In order to automatically load the sonypi module on use, you can put those
+lines a configuration file in /etc/modprobe.d/::
+
+	alias char-major-10-250 sonypi
+	options sonypi minor=250
+
+This supposes the use of minor 250 for the sonypi device::
+
+	# mknod /dev/sonypi c 10 250
+
+Bugs:
+-----
+
+	- several users reported that this driver disables the BIOS-managed
+	  Fn-keys which put the laptop in sleeping state, or switch the
+	  external monitor on/off. There is no workaround yet, since this
+	  driver disables all APM management for those keys, by enabling the
+	  ACPI management (and the ACPI core stuff is not complete yet). If
+	  you have one of those laptops with working Fn keys and want to
+	  continue to use them, don't use this driver.
+
+	- some users reported that the laptop speed is lower (dhrystone
+	  tested) when using the driver with the fnkeyinit parameter. I cannot
+	  reproduce it on my laptop and not all users have this problem.
+	  This happens because the fnkeyinit parameter enables the ACPI
+	  mode (but without additional ACPI control, like processor
+	  speed handling etc). Use ACPI instead of APM if it works on your
+	  laptop.
+
+	- sonypi lacks the ability to distinguish between certain key
+	  events on some models.
+
+	- some models with the nvidia card (geforce go 6200 tc) uses a
+	  different way to adjust the backlighting of the screen. There
+	  is a userspace utility to adjust the brightness on those models,
+	  which can be downloaded from
+	  https://www.acc.umu.se/~erikw/program/smartdimmer-0.1.tar.bz2
+
+	- since all development was done by reverse engineering, there is
+	  *absolutely no guarantee* that this driver will not crash your
+	  laptop. Permanently.
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
new file mode 100644
index 000000000..475eb0e81
--- /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(portugese), 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.
+=========	===============================================================
diff --git a/Documentation/admin-guide/laptops/toshiba_haps.rst b/Documentation/admin-guide/laptops/toshiba_haps.rst
new file mode 100644
index 000000000..d28b6c3f2
--- /dev/null
+++ b/Documentation/admin-guide/laptops/toshiba_haps.rst
@@ -0,0 +1,87 @@
+====================================
+Toshiba HDD Active Protection Sensor
+====================================
+
+Kernel driver: toshiba_haps
+
+Author: Azael Avalos <coproscefalo@gmail.com>
+
+
+.. 0. Contents
+
+   1. Description
+   2. Interface
+   3. Accelerometer axes
+   4. Supported devices
+   5. Usage
+
+
+1. Description
+--------------
+
+This driver provides support for the accelerometer found in various Toshiba
+laptops, being called "Toshiba HDD Protection - Shock Sensor" officially,
+and detects laptops automatically with this device.
+On Windows, Toshiba provided software monitors this device and provides
+automatic HDD protection (head unload) on sudden moves or harsh vibrations,
+however, this driver only provides a notification via a sysfs file to let
+userspace tools or daemons act accordingly, as well as providing a sysfs
+file to set the desired protection level or sensor sensibility.
+
+
+2. Interface
+------------
+
+This device comes with 3 methods:
+
+====	=====================================================================
+_STA    Checks existence of the device, returning Zero if the device does not
+	exists or is not supported.
+PTLV    Sets the desired protection level.
+RSSS    Shuts down the HDD protection interface for a few seconds,
+	then restores normal operation.
+====	=====================================================================
+
+Note:
+  The presence of Solid State Drives (SSD) can make this driver to fail loading,
+  given the fact that such drives have no movable parts, and thus, not requiring
+  any "protection" as well as failing during the evaluation of the _STA method
+  found under this device.
+
+
+3. Accelerometer axes
+---------------------
+
+This device does not report any axes, however, to query the sensor position
+a couple HCI (Hardware Configuration Interface) calls (0x6D and 0xA6) are
+provided to query such information, handled by the kernel module toshiba_acpi
+since kernel version 3.15.
+
+
+4. Supported devices
+--------------------
+
+This driver binds itself to the ACPI device TOS620A, and any Toshiba laptop
+with this device is supported, given the fact that they have the presence of
+conventional HDD and not only SSD, or a combination of both HDD and SSD.
+
+
+5. Usage
+--------
+
+The sysfs files under /sys/devices/LNXSYSTM:00/LNXSYBUS:00/TOS620A:00/ are:
+
+================   ============================================================
+protection_level   The protection_level is readable and writeable, and
+		   provides a way to let userspace query the current protection
+		   level, as well as set the desired protection level, the
+		   available protection levels are::
+
+		     ============   =======   ==========   ========
+		     0 - Disabled   1 - Low   2 - Medium   3 - High
+		     ============   =======   ==========   ========
+
+reset_protection   The reset_protection entry is writeable only, being "1"
+		   the only parameter it accepts, it is used to trigger
+		   a reset of the protection interface.
+================   ============================================================