Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

7 files changed, 3047 insertions, 0 deletions

diff --git a/Documentation/laptops/00-INDEX b/Documentation/laptops/00-INDEX
new file mode 100644
index 0000000..ee5692b
--- /dev/null
+++ b/Documentation/laptops/00-INDEX
@@ -0,0 +1,12 @@
+00-INDEX
+	- This file
+acer-wmi.txt
+	- information on the Acer Laptop WMI Extras driver.
+laptop-mode.txt
+	- how to conserve battery power using laptop-mode.
+sony-laptop.txt
+	- Sony Notebook Control Driver (SNC) Readme.
+sonypi.txt
+	- info on Linux Sony Programmable I/O Device support.
+thinkpad-acpi.txt
+	- information on the (IBM and Lenovo) ThinkPad ACPI Extras driver.
diff --git a/Documentation/laptops/acer-wmi.txt b/Documentation/laptops/acer-wmi.txt
new file mode 100644
index 0000000..2b3a6b5
--- /dev/null
+++ b/Documentation/laptops/acer-wmi.txt
@@ -0,0 +1,180 @@
+Acer Laptop WMI Extras Driver
+http://code.google.com/p/aceracpi
+Version 0.2
+18th August 2008
+
+Copyright 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
+
+acer-wmi is a driver to allow you to control various parts of your Acer laptop
+hardware under Linux which are exposed via ACPI-WMI.
+
+This driver completely replaces the old out-of-tree acer_acpi, which I am
+currently maintaining for bug fixes only on pre-2.6.25 kernels. All development
+work is now focused solely on acer-wmi.
+
+Disclaimer
+**********
+
+Acer and Wistron have provided nothing towards the development acer_acpi or
+acer-wmi. All information we have has been through the efforts of the developers
+and the users to discover as much as possible about the hardware.
+
+As such, I do warn that this could break your hardware - this is extremely
+unlikely of course, but please bear this in mind.
+
+Background
+**********
+
+acer-wmi is derived from acer_acpi, originally developed by Mark
+Smith in 2005, then taken over by Carlos Corbacho in 2007, in order to activate
+the wireless LAN card under a 64-bit version of Linux, as acerhk[1] (the
+previous solution to the problem) relied on making 32 bit BIOS calls which are
+not possible in kernel space from a 64 bit OS.
+
+[1] acerhk: http://www.cakey.de/acerhk/
+
+Supported Hardware
+******************
+
+Please see the website for the current list of known working hardare:
+
+http://code.google.com/p/aceracpi/wiki/SupportedHardware
+
+If your laptop is not listed, or listed as unknown, and works with acer-wmi,
+please contact me with a copy of the DSDT.
+
+If your Acer laptop doesn't work with acer-wmi, I would also like to see the
+DSDT.
+
+To send me the DSDT, as root/sudo:
+
+cat /sys/firmware/acpi/tables/DSDT > dsdt
+
+And send me the resulting 'dsdt' file.
+
+Usage
+*****
+
+On Acer laptops, acer-wmi should already be autoloaded based on DMI matching.
+For non-Acer laptops, until WMI based autoloading support is added, you will
+need to manually load acer-wmi.
+
+acer-wmi creates /sys/devices/platform/acer-wmi, and fills it with various
+files whose usage is detailed below, which enables you to control some of the
+following (varies between models):
+
+* the wireless LAN card radio
+* inbuilt Bluetooth adapter
+* inbuilt 3G card
+* mail LED of your laptop
+* brightness of the LCD panel
+
+Wireless
+********
+
+With regards to wireless, all acer-wmi does is enable the radio on the card. It
+is not responsible for the wireless LED - once the radio is enabled, this is
+down to the wireless driver for your card. So the behaviour of the wireless LED,
+once you enable the radio, will depend on your hardware and driver combination.
+
+e.g. With the BCM4318 on the Acer Aspire 5020 series:
+
+ndiswrapper: Light blinks on when transmitting
+b43: Solid light, blinks off when transmitting
+
+Wireless radio control is unconditionally enabled - all Acer laptops that support
+acer-wmi come with built-in wireless. However, should you feel so inclined to
+ever wish to remove the card, or swap it out at some point, please get in touch
+with me, as we may well be able to gain some data on wireless card detection.
+
+The wireless radio is exposed through rfkill.
+
+Bluetooth
+*********
+
+For bluetooth, this is an internal USB dongle, so once enabled, you will get
+a USB device connection event, and a new USB device appears. When you disable
+bluetooth, you get the reverse - a USB device disconnect event, followed by the
+device disappearing again.
+
+Bluetooth is autodetected by acer-wmi, so if you do not have a bluetooth module
+installed in your laptop, this file won't exist (please be aware that it is
+quite common for Acer not to fit bluetooth to their laptops - so just because
+you have a bluetooth button on the laptop, doesn't mean that bluetooth is
+installed).
+
+For the adventurously minded - if you want to buy an internal bluetooth
+module off the internet that is compatible with your laptop and fit it, then
+it will work just fine with acer-wmi.
+
+Bluetooth is exposed through rfkill.
+
+3G
+**
+
+3G is currently not autodetected, so the 'threeg' file is always created under
+sysfs. So far, no-one in possession of an Acer laptop with 3G built-in appears to
+have tried Linux, or reported back, so we don't have any information on this.
+
+If you have an Acer laptop that does have a 3G card in, please contact me so we
+can properly detect these, and find out a bit more about them.
+
+To read the status of the 3G card (0=off, 1=on):
+cat /sys/devices/platform/acer-wmi/threeg
+
+To enable the 3G card:
+echo 1 > /sys/devices/platform/acer-wmi/threeg
+
+To disable the 3G card:
+echo 0 > /sys/devices/platform/acer-wmi/threeg
+
+To set the state of the 3G card when loading acer-wmi, pass:
+threeg=X (where X is 0 or 1)
+
+Mail LED
+********
+
+This can be found in most older Acer laptops supported by acer-wmi, and many
+newer ones - it is built into the 'mail' button, and blinks when active.
+
+On newer (WMID) laptops though, we have no way of detecting the mail LED. If
+your laptop identifies itself in dmesg as a WMID model, then please try loading
+acer_acpi with:
+
+force_series=2490
+
+This will use a known alternative method of reading/ writing the mail LED. If
+it works, please report back to me with the DMI data from your laptop so this
+can be added to acer-wmi.
+
+The LED is exposed through the LED subsystem, and can be found in:
+
+/sys/devices/platform/acer-wmi/leds/acer-wmi::mail/
+
+The mail LED is autodetected, so if you don't have one, the LED device won't
+be registered.
+
+Backlight
+*********
+
+The backlight brightness control is available on all acer-wmi supported
+hardware. The maximum brightness level is usually 15, but on some newer laptops
+it's 10 (this is again autodetected).
+
+The backlight is exposed through the backlight subsystem, and can be found in:
+
+/sys/devices/platform/acer-wmi/backlight/acer-wmi/
+
+Credits
+*******
+
+Olaf Tauber, who did the real hard work when he developed acerhk
+http://www.informatik.hu-berlin.de/~tauber/acerhk
+All the authors of laptop ACPI modules in the kernel, whose work
+was an inspiration in the early days of acer_acpi
+Mathieu Segaud, who solved the problem with having to modprobe the driver
+twice in acer_acpi 0.2.
+Jim Ramsay, who added support for the WMID interface
+Mark Smith, who started the original acer_acpi
+
+And the many people who have used both acer_acpi and acer-wmi.
diff --git a/Documentation/laptops/disk-shock-protection.txt b/Documentation/laptops/disk-shock-protection.txt
new file mode 100644
index 0000000..0e6ba26
--- /dev/null
+++ b/Documentation/laptops/disk-shock-protection.txt
@@ -0,0 +1,149 @@
+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.
+
+- http://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/laptops/laptop-mode.txt b/Documentation/laptops/laptop-mode.txt
new file mode 100644
index 0000000..eeedee1
--- /dev/null
+++ b/Documentation/laptops/laptop-mode.txt
@@ -0,0 +1,950 @@
+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.
+
+If you want to find out which process caused the disk to spin up, you can
+gather information by setting the flag /proc/sys/vm/block_dump. When this flag
+is set, Linux reports all disk read and write operations that take place, and
+all block dirtyings done to files. This makes it possible to debug why a disk
+needs to spin up, and to increase battery life even more. The output of
+block_dump is written to the kernel output, and it can be retrieved using
+"dmesg". When you use block_dump and your kernel logging level also includes
+kernel debugging messages, you probably want to turn off klogd, otherwise
+the output of block_dump will be logged, causing disk activity that is not
+normally there.
+
+
+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/cpu-freq/user-guide.txt 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 it's 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 BEGIN-------------------------------------------
+# 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 pdflush 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/cpu-freq/user-guide.txt 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
+
+--------------------CONFIG FILE END---------------------------------------------
+
+
+Control script
+--------------
+
+Please note that this control script works for the Linux 2.4 and 2.6 series (thanks
+to Kiko Piris).
+
+--------------------CONTROL SCRIPT BEGIN----------------------------------------
+#!/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=${DIRTY_RATIO:-'40'}
+
+# cpu frequency scaling
+# See Documentation/cpu-freq/user-guide.txt for more info
+DO_CPU=${CPU_MANAGE:-'0'}
+CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'}
+
+#
+# Allowed dirty background ratio, in percent.  Once DIRTY_RATIO has been
+# exceeded, the kernel will wake pdflush which will then reduce the amount
+# of dirty memory to dirty_background_ratio.  Set this nice and low, so once
+# some writeout has commenced, we do a lot of it.
+#
+DIRTY_BACKGROUND_RATIO=${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
+--------------------CONTROL SCRIPT END------------------------------------------
+
+
+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 BEGIN------------------------------
+event=ac_adapter
+action=/etc/acpi/actions/ac.sh %e
+----------------/etc/acpi/events/ac_adapter END---------------------------------
+
+
+-----------------/etc/acpi/events/battery BEGIN---------------------------------
+event=battery.*
+action=/etc/acpi/actions/battery.sh %e
+----------------/etc/acpi/events/battery END------------------------------------
+
+
+----------------/etc/acpi/actions/ac.sh BEGIN-----------------------------------
+#!/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/ac.sh END--------------------------
+
+
+---------------------------/etc/acpi/actions/battery.sh BEGIN-------------------
+#! /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
+---------------------------/etc/acpi/actions/battery.sh END--------------------
+
+
+Monitoring tool
+---------------
+
+Bartek Kania submitted this, it can be used to measure how much time your disk
+spends spun up/down.
+
+---------------------------dslm.c BEGIN-----------------------------------------
+/*
+ * Simple Disk Sleep Monitor
+ *  by Bartek Kania
+ * Licenced under the GPL
+ */
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <time.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <linux/hdreg.h>
+
+#ifdef DEBUG
+#define D(x) x
+#else
+#define D(x)
+#endif
+
+int endit = 0;
+
+/* Check if the disk is in powersave-mode
+ * Most of the code is stolen from hdparm.
+ * 1 = active, 0 = standby/sleep, -1 = unknown */
+int check_powermode(int fd)
+{
+    unsigned char args[4] = {WIN_CHECKPOWERMODE1,0,0,0};
+    int state;
+
+    if (ioctl(fd, HDIO_DRIVE_CMD, &args)
+	&& (args[0] = WIN_CHECKPOWERMODE2) /* try again with 0x98 */
+	&& ioctl(fd, HDIO_DRIVE_CMD, &args)) {
+	if (errno != EIO || args[0] != 0 || args[1] != 0) {
+	    state = -1; /* "unknown"; */
+	} else
+	    state = 0; /* "sleeping"; */
+    } else {
+	state = (args[2] == 255) ? 1 : 0;
+    }
+    D(printf(" drive state is:  %d\n", state));
+
+    return state;
+}
+
+char *state_name(int i)
+{
+    if (i == -1) return "unknown";
+    if (i == 0) return "sleeping";
+    if (i == 1) return "active";
+
+    return "internal error";
+}
+
+char *myctime(time_t time)
+{
+    char *ts = ctime(&time);
+    ts[strlen(ts) - 1] = 0;
+
+    return ts;
+}
+
+void measure(int fd)
+{
+    time_t start_time;
+    int last_state;
+    time_t last_time;
+    int curr_state;
+    time_t curr_time = 0;
+    time_t time_diff;
+    time_t active_time = 0;
+    time_t sleep_time = 0;
+    time_t unknown_time = 0;
+    time_t total_time = 0;
+    int changes = 0;
+    float tmp;
+
+    printf("Starting measurements\n");
+
+    last_state = check_powermode(fd);
+    start_time = last_time = time(0);
+    printf("  System is in state %s\n\n", state_name(last_state));
+
+    while(!endit) {
+	sleep(1);
+	curr_state = check_powermode(fd);
+
+	if (curr_state != last_state || endit) {
+	    changes++;
+	    curr_time = time(0);
+	    time_diff = curr_time - last_time;
+
+	    if (last_state == 1) active_time += time_diff;
+	    else if (last_state == 0) sleep_time += time_diff;
+	    else unknown_time += time_diff;
+
+	    last_state = curr_state;
+	    last_time = curr_time;
+
+	    printf("%s: State-change to %s\n", myctime(curr_time),
+		   state_name(curr_state));
+	}
+    }
+    changes--; /* Compensate for SIGINT */
+
+    total_time = time(0) - start_time;
+    printf("\nTotal running time:  %lus\n", curr_time - start_time);
+    printf(" State changed %d times\n", changes);
+
+    tmp = (float)sleep_time / (float)total_time * 100;
+    printf(" Time in sleep state:   %lus (%.2f%%)\n", sleep_time, tmp);
+    tmp = (float)active_time / (float)total_time * 100;
+    printf(" Time in active state:  %lus (%.2f%%)\n", active_time, tmp);
+    tmp = (float)unknown_time / (float)total_time * 100;
+    printf(" Time in unknown state: %lus (%.2f%%)\n", unknown_time, tmp);
+}
+
+void ender(int s)
+{
+    endit = 1;
+}
+
+void usage()
+{
+    puts("usage: dslm [-w <time>] <disk>");
+    exit(0);
+}
+
+int main(int argc, char **argv)
+{
+    int fd;
+    char *disk = 0;
+    int settle_time = 60;
+
+    /* Parse the simple command-line */
+    if (argc == 2)
+	disk = argv[1];
+    else if (argc == 4) {
+	settle_time = atoi(argv[2]);
+	disk = argv[3];
+    } else
+	usage();
+
+    if (!(fd = open(disk, O_RDONLY|O_NONBLOCK))) {
+	printf("Can't open %s, because: %s\n", disk, strerror(errno));
+	exit(-1);
+    }
+
+    if (settle_time) {
+	printf("Waiting %d seconds for the system to settle down to "
+	       "'normal'\n", settle_time);
+	sleep(settle_time);
+    } else
+	puts("Not waiting for system to settle down");
+
+    signal(SIGINT, ender);
+
+    measure(fd);
+
+    close(fd);
+
+    return 0;
+}
+---------------------------dslm.c END-------------------------------------------
diff --git a/Documentation/laptops/sony-laptop.txt b/Documentation/laptops/sony-laptop.txt
new file mode 100644
index 0000000..8b2bc15
--- /dev/null
+++ b/Documentation/laptops/sony-laptop.txt
@@ -0,0 +1,116 @@
+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 acpid or /proc/acpi/event and
+/proc/bus/input/devices to find out what those events are and which input
+devices are created by the driver.
+
+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 iteger
+				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.
+
+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. You can see the GCDP/GCDP methods
+used to pwer on/off the CD drive, but there are others.
+
+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 could use sony-laptop to do (part of) its business.
+
+* spicctrl, which is the userspace tool used to communicate with the
+  sonypi driver (through /dev/sonypi) does not try to use the
+  sony-laptop driver. In the future, spicctrl could try sonypi first,
+  and if it isn't present, try sony-laptop instead.
diff --git a/Documentation/laptops/sonypi.txt b/Documentation/laptops/sonypi.txt
new file mode 100644
index 0000000..4857acf
--- /dev/null
+++ b/Documentation/laptops/sonypi.txt
@@ -0,0 +1,152 @@
+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 in your /etc/modprobe.conf file:
+
+	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
+	  http://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/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
new file mode 100644
index 0000000..71f0fe1
--- /dev/null
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -0,0 +1,1488 @@
+		     ThinkPad ACPI Extras Driver
+
+                            Version 0.21
+                           May 29th, 2008
+
+               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.
+
+The driver is named "thinkpad-acpi".  In some places, like module
+names, "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
+	- limited docking and undocking
+	- UltraBay eject
+	- CMOS 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
+
+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 DSDT, from /proc/acpi/dsdt
+	- 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, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
+enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
+thinkpad-specific bay functionality.
+
+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 distant 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".
+
+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 hot key feature automatically when loaded.  The
+feature can later be disabled and enabled back at runtime.  The driver
+will also restore the hot key feature to its previous state and mask
+when it is unloaded.
+
+When the hotkey feature is enabled and the hot key mask is set (see
+below), 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.
+
+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, and in those
+models, hot keys cannot be controlled individually.  The behaviour of
+the mask is, therefore, highly dependent on the ThinkPad model.
+
+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.
+
+Note also that not all Fn key combinations are supported through ACPI.
+For example, on the X40, the brightness, volume and "Access IBM" buttons
+do not generate ACPI events even with this driver.  They *can* be used
+through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
+
+procfs notes:
+
+The following commands can be written to the /proc/acpi/ibm/hotkey file:
+
+	echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
+	echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
+	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 original mask
+
+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:
+		Returns the status of the hot keys feature when
+		thinkpad-acpi was loaded.  Upon module unload, the hot
+		key feature status will be restored to this value.
+
+		0: hot keys were disabled
+		1: hot keys were enabled (unusual)
+
+	hotkey_bios_mask:
+		Returns the hot keys mask when thinkpad-acpi was loaded.
+		Upon module unload, the hot keys mask will be restored
+		to this value.
+
+	hotkey_enable:
+		Enables/disables the hot keys feature in the ACPI
+		firmware, and reports current status of the hot keys
+		feature.  Has no effect on the NVRAM hot key polling
+		functionality.
+
+		0: disables the hot keys feature / feature disabled
+		1: enables the hot keys feature / feature enabled
+
+	hotkey_mask:
+		bit mask to enable driver-handling (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.
+
+		Note: when NVRAM polling is active, the firmware mask
+		will be different from the value returned by
+		hotkey_mask.  The driver will retain enabled bits for
+		hotkeys that are under NVRAM polling even if the
+		firmware refuses them, and will not set these bits on
+		the firmware hot key mask.
+
+	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.
+
+	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 both hotkey_source_mask
+		and also on hotkey_mask are polled for in NVRAM.  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,
+		so you have to use volume up or volume down to unmute,
+		as per the ThinkPad volume mixer user interface.  When
+		in ACPI event mode, volume up/down/mute are reported as
+		separate events, but this behaviour may be corrected in
+		future releases of this driver, in which case the
+		ThinkPad volume mixer user interface semantics will be
+		enforced.
+
+	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 will 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.
+
+	hotkey_report_mode:
+		Returns the state of the procfs ACPI event report mode
+		filter for hot keys.  If it is set to 1 (the default),
+		all hot key presses are reported both through the input
+		layer and also as ACPI events through procfs (but not
+		through netlink).  If it is set to 2, hot key presses
+		are reported only through the input layer.
+
+		This attribute is read-only in kernels 2.6.23 or later,
+		and read-write on earlier kernels.
+
+		May return -EPERM (write access locked out by module
+		parameter) or -EACCES (read-only).
+
+	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
+				Lenovo: battery
+
+0x1004	0x03	FN+F4		Sleep button (ACPI sleep button
+				semantics, i.e. sleep-to-RAM).
+				It is always generate some kind
+				of event, either the hot key
+				event or a 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
+
+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+F4 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.
+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 hardare rfkill rocker switch
+SW_TABLET_MODE	Tablet ThinkPads HKEY events 0x5009 and 0x500A
+
+Non hot-key ACPI HKEY event map:
+0x5001		Lid closed
+0x5002		Lid opened
+0x5009		Tablet swivel: switched to tablet mode
+0x500A		Tablet swivel: switched to normal mode
+0x7000		Radio Switch may have changed state
+
+The above events are not propagated by the driver, except for legacy
+compatibility purposes when hotkey_report_mode is set to 1.
+
+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
+
+The above events are never propagated by the driver.
+
+0x3003		Bay ejection (see 0x2x05) complete, can sleep again
+0x4003		Undocked (see 0x2x04), can sleep again
+0x500B		Tablet pen inserted into its storage bay
+0x500C		Tablet pen removed from its storage bay
+0x5010		Brightness level changed (newer Lenovo BIOSes)
+
+The above events are propagated by the driver.
+
+Compatibility notes:
+
+ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
+supported the input layer, and sent events over the procfs ACPI event
+interface.
+
+To avoid sending duplicate events over the input layer and the ACPI
+event interface, thinkpad-acpi 0.16 implements a module parameter
+(hotkey_report_mode), and also a sysfs device attribute with the same
+name.
+
+Make no mistake here: userspace is expected to switch to using the input
+layer interface of thinkpad-acpi, together with the ACPI netlink event
+interface in kernels 2.6.23 and later, or with the ACPI procfs event
+interface in kernels 2.6.22 and earlier.
+
+If no hotkey_report_mode module parameter is specified (or it is set to
+zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
+and earlier, also allows one to change the hotkey_report_mode through
+sysfs.  In kernels 2.6.23 and later, where the netlink ACPI event
+interface is available, hotkey_report_mode cannot be changed through
+sysfs (it is read-only).
+
+If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
+be changed later through sysfs (any writes will return -EPERM to signal
+that hotkey_report_mode was locked.  On 2.6.23 and later, where
+hotkey_report_mode cannot be changed at all, writes will return -EACCES).
+
+hotkey_report_mode set to 1 makes the driver export through the procfs
+ACPI event interface all hot key presses (which are *also* sent to the
+input layer).  This is a legacy compatibility behaviour, and it is also
+the default mode of operation for the driver.
+
+hotkey_report_mode set to 2 makes the driver filter out the hot key
+presses from the procfs ACPI event interface, so these events will only
+be sent through the input layer.  Userspace that has been updated to use
+the thinkpad-acpi input layer interface should set hotkey_report_mode to
+2.
+
+Hot key press events are never sent to the ACPI netlink event interface.
+Really up-to-date userspace under kernel 2.6.23 and later is to use the
+netlink interface and the input layer interface, and don't bother at all
+with hotkey_report_mode.
+
+
+Brightness hotkey notes:
+
+These are the current sane choices for brightness key mapping in
+thinkpad-acpi:
+
+For IBM and Lenovo models *without* ACPI backlight control (the ones on
+which thinkpad-acpi will autoload its backlight interface by default,
+and on which ACPI video does not export a backlight interface):
+
+1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as
+   these older firmware versions unfortunately won't respect the hotkey
+   mask for brightness keys anyway, and always reacts to them.  This
+   usually work fine, unless X.org drivers are doing something to block
+   the BIOS.  In that case, use (3) below.  This is the default mode of
+   operation.
+
+2. Enable the hotkeys, but map them to something else that is NOT
+   KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause
+   userspace to try to change the backlight level, and use that as an
+   on-screen-display hint.
+
+3. IF AND ONLY IF X.org drivers find a way to block the firmware from
+   automatically changing the brightness, enable the hotkeys and map
+   them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to
+   something that calls xbacklight.  thinkpad-acpi will not be able to
+   change brightness in that case either, so you should disable its
+   backlight interface.
+
+For Lenovo models *with* ACPI backlight control:
+
+1. Load up ACPI video and use that.  ACPI video will report ACPI
+   events for brightness change keys.  Do not mess with thinkpad-acpi
+   defaults in this case.  thinkpad-acpi should not have anything to do
+   with backlight events in a scenario where ACPI video is loaded:
+   brightness hotkeys must be disabled, and the backlight interface is
+   to be kept disabled as well.  This is the default mode of operation.
+
+2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
+   and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN.  Process
+   these keys on userspace somehow (e.g. by calling xbacklight).
+
+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.
+
+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/rfkill.txt 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
+
+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: There's now a patch for the X.org Radeon driver which
+addresses this issue. Some people are reporting success with the patch
+while others are still having problems. For more information:
+
+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-class.txt.  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.
+
+Docking / undocking -- /proc/acpi/ibm/dock
+------------------------------------------
+
+Docking and undocking (e.g. with the X4 UltraBase) requires some
+actions to be taken by the operating system to safely make or break
+the electrical connections with the dock.
+
+The docking feature of this driver generates the following ACPI events:
+
+	ibm/dock GDCK 00000003 00000001 -- eject request
+	ibm/dock GDCK 00000003 00000002 -- undocked
+	ibm/dock GDCK 00000000 00000003 -- docked
+
+NOTE: These events will only be generated if the laptop was docked
+when originally booted. This is due to the current lack of support for
+hot plugging of devices in the Linux ACPI framework. If the laptop was
+booted while not in the dock, the following message is shown in the
+logs:
+
+	Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
+
+In this case, no dock-related events are generated but the dock and
+undock commands described below still work. They can be executed
+manually or triggered by Fn key combinations (see the example acpid
+configuration files included in the driver tarball package available
+on the web site).
+
+When the eject request button on the dock is pressed, the first event
+above is generated. The handler for this event should issue the
+following command:
+
+	echo undock > /proc/acpi/ibm/dock
+
+After the LED on the dock goes off, it is safe to eject the laptop.
+Note: if you pressed this key by mistake, go ahead and eject the
+laptop, then dock it back in. Otherwise, the dock may not function as
+expected.
+
+When the laptop is docked, the third event above is generated. The
+handler for this event should issue the following command to fully
+enable the dock:
+
+	echo dock > /proc/acpi/ibm/dock
+
+The contents of the /proc/acpi/ibm/dock file shows the current status
+of the dock, as provided by the ACPI framework.
+
+The docking support in this driver does not take care of enabling or
+disabling any other devices you may have attached to the dock. For
+example, a CD drive plugged into the UltraBase needs to be disabled or
+enabled separately. See the provided example acpid configuration files
+for how this can be accomplished.
+
+There is no support yet for PCI devices that may be attached to a
+docking station, e.g. in the ThinkPad Dock II. The driver currently
+does not recognize, enable or disable such devices. This means that
+the only docking stations currently supported are the X-series
+UltraBase docks and "dumb" port replicators like the Mini Dock (the
+latter don't need any ACPI support, actually).
+
+UltraBay eject -- /proc/acpi/ibm/bay
+------------------------------------
+
+Inserting or ejecting an UltraBay device requires some actions to be
+taken by the operating system to safely make or break the electrical
+connections with the device.
+
+This feature generates the following ACPI events:
+
+	ibm/bay MSTR 00000003 00000000 -- eject request
+	ibm/bay MSTR 00000001 00000000 -- eject lever inserted
+
+NOTE: These events will only be generated if the UltraBay was present
+when the laptop was originally booted (on the X series, the UltraBay
+is in the dock, so it may not be present if the laptop was undocked).
+This is due to the current lack of support for hot plugging of devices
+in the Linux ACPI framework. If the laptop was booted without the
+UltraBay, the following message is shown in the logs:
+
+	Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
+
+In this case, no bay-related events are generated but the eject
+command described below still works. It can be executed manually or
+triggered by a hot key combination.
+
+Sliding the eject lever generates the first event shown above. The
+handler for this event should take whatever actions are necessary to
+shut down the device in the UltraBay (e.g. call idectl), then issue
+the following command:
+
+	echo eject > /proc/acpi/ibm/bay
+
+After the LED on the UltraBay goes off, it is safe to pull out the
+device.
+
+When the eject lever is inserted, the second event above is
+generated. The handler for this event should take whatever actions are
+necessary to enable the UltraBay device (e.g. call idectl).
+
+The contents of the /proc/acpi/ibm/bay file shows the current status
+of the UltraBay, as provided by the ACPI framework.
+
+EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
+this feature, you need to supply the experimental=1 parameter when
+loading the module):
+
+These models do not have a button near the UltraBay device to request
+a hot eject but rather require the laptop to be put to sleep
+(suspend-to-ram) before the bay device is ejected or inserted).
+The sequence of steps to eject the device is as follows:
+
+	echo eject > /proc/acpi/ibm/bay
+	put the ThinkPad to sleep
+	remove the drive
+	resume from sleep
+	cat /proc/acpi/ibm/bay should show that the drive was removed
+
+On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
+supported. Use "eject2" instead of "eject" for the second bay.
+
+Note: the UltraBay eject support on the 600e/x, A22p and A3x is
+EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
+
+CMOS 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.
+
+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 7. 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
+
+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-class.txt.
+
+The leds are named (in LED ID order, from 0 to 7):
+"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
+"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
+"tpacpi::unknown_led", "tpacpi::standby".
+
+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).
+
+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).
+
+http://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)
+http://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, http://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 -- /proc/acpi/ibm/ecdump
+------------------------------------------------------------------------
+
+This feature is marked EXPERIMENTAL because the implementation
+directly accesses hardware registers and may not work as expected. USE
+WITH CAUTION! To use this feature, you need to supply the
+experimental=1 parameter when loading the module.
+
+This feature dumps the values of 256 embedded controller
+registers. Values which have changed since the last time the registers
+were dumped are marked with a star:
+
+[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
+EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
+EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00
+EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00
+EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80
+EC 0x30:  01  07  1a  00  30  04  00  00 *85  00  00  10  00  50  00  00
+EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00
+EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03 *bc *02 *bc
+EC 0x60: *02 *bc *02  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0x70:  00  00  00  00  00  12  30  40 *24 *26 *2c *27 *20  80 *1f  80
+EC 0x80:  00  00  00  06 *37 *0e  03  00  00  00  0e  07  00  00  00  00
+EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xa0: *ff  09  ff  09  ff  ff *64  00 *00 *00 *a2  41 *ff *ff *e0  00
+EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03
+EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a
+
+This feature can be used 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
+	- run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
+
+The first step makes sure various charging-related values don't
+vary. The second ensures that the fan-related values do vary, since
+the fan speed fluctuates a bit. The third will (hopefully) mark the
+fan register with a star:
+
+[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
+EC       +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
+EC 0x00:  a7  47  87  01  fe  96  00  08  01  00  cb  00  00  00  40  00
+EC 0x10:  00  00  ff  ff  f4  3c  87  09  01  ff  42  01  ff  ff  0d  00
+EC 0x20:  00  00  00  00  00  00  00  00  00  00  00  03  43  00  00  80
+EC 0x30:  01  07  1a  00  30  04  00  00  85  00  00  10  00  50  00  00
+EC 0x40:  00  00  00  00  00  00  14  01  00  04  00  00  00  00  00  00
+EC 0x50:  00  c0  02  0d  00  01  01  02  02  03  03  03  03  bc  02  bc
+EC 0x60:  02  bc  02  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0x70:  00  00  00  00  00  12  30  40  24  27  2c  27  21  80  1f  80
+EC 0x80:  00  00  00  06 *be  0d  03  00  00  00  0e  07  00  00  00  00
+EC 0x90:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xa0:  ff  09  ff  09  ff  ff  64  00  00  00  a2  41  ff  ff  e0  00
+EC 0xb0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xc0:  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xd0:  03  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+EC 0xe0:  00  00  00  00  00  00  00  00  11  20  49  04  24  06  55  03
+EC 0xf0:  31  55  48  54  35  38  57  57  08  2f  45  73  07  65  6c  1a
+
+Another set of values that varies often is the temperature
+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, and in many ThinkPad models, the "dim while on
+battery" functionality will be enabled by the BIOS when this interface is
+used, and cannot be controlled.
+
+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.
+
+There are two interfaces to the firmware for direct brightness control,
+EC and CMOS.  To select which one should be used, use the
+brightness_mode module parameter: brightness_mode=1 selects EC mode,
+brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
+and CMOS.  The driver tries to auto-detect which interface to use.
+
+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.
+
+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 -- /proc/acpi/ibm/volume
+---------------------------------------
+
+This feature allows volume control on ThinkPad models which don't have
+a hardware volume knob. The available commands are:
+
+	echo up   >/proc/acpi/ibm/volume
+	echo down >/proc/acpi/ibm/volume
+	echo mute >/proc/acpi/ibm/volume
+	echo 'level <level>' >/proc/acpi/ibm/volume
+
+The <level> number range is 0 to 15 although not all of them may be
+distinct. The unmute the volume after the mute command, use either the
+up or down command (the level command will not unmute the volume).
+The current volume level and mute state is shown in the file.
+
+Fan control and monitoring: fan speed, fan enable/disable
+---------------------------------------------------------
+
+procfs: /proc/acpi/ibm/fan
+sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
+			  pwm1_enable
+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.
+
+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 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 a W-WAN (Sierra
+Wireless EV-DO) device.
+
+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/rfkill.txt for details.
+
+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
+	0x0001			Initialization and probing
+	0x0002			Removal
+
+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 an 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