thinkpad-acpi.txt 59.2 KB
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		     ThinkPad ACPI Extras Driver
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                            Version 0.23
                          April 10th, 2009
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               Borislav Deianov <borislav@users.sf.net>
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             Henrique de Moraes Holschuh <hmh@hmh.eng.br>
                      http://ibm-acpi.sf.net/
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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
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2.6.22, and release 0.14.  It was moved to drivers/platform/x86 for
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kernel 2.6.29 and release 0.22.
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The driver is named "thinkpad-acpi".  In some places, like module
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names and log messages, "thinkpad_acpi" is used because of userspace
issues.
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"tpacpi" is used as a shorthand where "thinkpad-acpi" would be too
long due to length limitations on some Linux kernel versions.
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Status
------

The features currently supported are the following (see below for
detailed description):

	- Fn key combinations
	- Bluetooth enable and disable
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	- video output switching, expansion control
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	- ThinkLight on and off
	- limited docking and undocking
	- UltraBay eject
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	- CMOS/UCMS control
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	- LED control
	- ACPI sounds
	- temperature sensors
	- Experimental: embedded controller register dump
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	- LCD brightness control
	- Volume control
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	- Fan control and monitoring: fan speed, fan enable/disable
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	- WAN enable and disable
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	- UWB enable and disable
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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
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	- a copy of your ACPI tables, using the "acpidump" utility
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	- a copy of the output of dmidecode, with serial numbers
	  and UUIDs masked off
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	- 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
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sources, look for the CONFIG_THINKPAD_ACPI Kconfig option.
It is located on the menu path: "Device Drivers" -> "X86 Platform
Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras".

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Features
--------

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The driver exports two different interfaces to userspace, which can be
used to access the features it provides.  One is a legacy procfs-based
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interface, which will be removed at some time in the future.  The other
is a new sysfs-based interface which is not complete yet.
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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.
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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,
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for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and
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/sys/bus/platform/drivers/thinkpad_hwmon/
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Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
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space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/.
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Sysfs device attributes for the sensors and fan are on the
thinkpad_hwmon device's sysfs attribute space, but you should locate it
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looking for a hwmon device with the name attribute of "thinkpad", or
better yet, through libsensors.

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Driver version
--------------

procfs: /proc/acpi/ibm/driver
sysfs driver attribute: version
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The driver name and version. No commands can be written to this file.

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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.

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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).

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Hot keys
--------

procfs: /proc/acpi/ibm/hotkey
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sysfs device attribute: hotkey_*
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In a ThinkPad, the ACPI HKEY handler is responsible for communicating
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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.

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The driver enables the HKEY ("hot key") event reporting automatically
when loaded, and disables it when it is removed.
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The driver will report HKEY events in the following format:
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	ibm/hotkey HKEY 00000080 0000xxxx

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Some of these events refer to hot key presses, but not all of them.
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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.
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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
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the mask is, therefore, highly dependent on the ThinkPad model.
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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/
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procfs notes:

The following commands can be written to the /proc/acpi/ibm/hotkey file:

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	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 ...
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	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask

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The following commands have been deprecated and will cause the kernel
to log a warning:

	echo enable > /proc/acpi/ibm/hotkey -- does nothing
	echo disable > /proc/acpi/ibm/hotkey -- returns an error

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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.

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sysfs notes:

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	hotkey_bios_enabled:
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		DEPRECATED, WILL BE REMOVED SOON.
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		Returns 0.
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	hotkey_bios_mask:
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		Returns the hot keys mask when thinkpad-acpi was loaded.
		Upon module unload, the hot keys mask will be restored
		to this value.

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	hotkey_enable:
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		DEPRECATED, WILL BE REMOVED SOON.
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		0: returns -EPERM
		1: does nothing
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	hotkey_mask:
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		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.
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	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
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		supported hot keys, except those which are always
		handled by the firmware anyway.  Echo it to
		hotkey_mask above, to use.
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	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
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		ThinkPad volume mixer user interface semantics will be
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		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.

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	hotkey_radio_sw:
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		If the ThinkPad has a hardware radio switch, this
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		attribute will read 0 if the switch is in the "radios
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		disabled" position, and 1 if the switch is in the
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		"radios enabled" position.

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		This attribute has poll()/select() support.

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	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.

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	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).

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	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.

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		This attribute has poll()/select() support.

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	wakeup_hotunplug_complete:
		Set to 1 if the system was waken up because of an
		undock or bay ejection request, and that request
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		was successfully completed.  At this point, it might
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		be useful to send the system back to sleep, at the
		user's choice.  Refer to HKEY events 0x4003 and
		0x3003, below.

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		This attribute has poll()/select() support.

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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
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	vendor:		0x1014 (PCI_VENDOR_ID_IBM)  or
			0x17aa (PCI_VENDOR_ID_LENOVO)
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	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		-
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0x1002	0x01	FN+F2		IBM: battery (rare)
				Lenovo: Screen lock
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0x1003	0x02	FN+F3		Many IBM models always report
				this hot key, even with hot keys
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				disabled or with Fn+F3 masked
				off
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				IBM: screen lock
				Lenovo: battery
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0x1004	0x03	FN+F4		Sleep button (ACPI sleep button
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				semantics, i.e. sleep-to-RAM).
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				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
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				the internal Bluetooth hardware
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				and W-WAN card if left in control
				of the firmware.  Does not affect
				the WLAN card.
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				Should be used to turn on/off all
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				radios (Bluetooth+W-WAN+WLAN),
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				really.
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0x1006	0x05	FN+F6		-

0x1007	0x06	FN+F7		Video output cycle.
				Do you feel lucky today?

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0x1008	0x07	FN+F8		IBM: toggle screen expand
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				Lenovo: configure UltraNav
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0x1009	0x08	FN+F9		-
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	..	..		..
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
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				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.

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0x1012	0x11	FN+PGUP		ThinkLight toggle.  This key is
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				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.
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				NOTE: Lenovo seems to be changing
				this.
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0x1016	0x15	VOLUME DOWN	Internal mixer volume up. This
				key is always handled by the
				firmware, even when unmasked.
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				NOTE: Lenovo seems to be changing
				this.
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0x1017	0x16	MUTE		Mute internal mixer. This
				key is always handled by the
				firmware, even when unmasked.

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0x1018	0x17	THINKPAD	ThinkPad/Access IBM/Lenovo key
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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.

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If a key is mapped to KEY_RESERVED, it generates no input events at all.
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If a key is mapped to KEY_UNKNOWN, it generates an input event that
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includes an scan code.  If a key is mapped to anything else, it will
generate input device EV_KEY events.
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In addition to the EV_KEY events, thinkpad-acpi may also issue EV_SW
events for switches:

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SW_RFKILL_ALL	T60 and later hardare rfkill rocker switch
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SW_TABLET_MODE	Tablet ThinkPads HKEY events 0x5009 and 0x500A

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Non hot-key ACPI HKEY event map:
0x5001		Lid closed
0x5002		Lid opened
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0x5009		Tablet swivel: switched to tablet mode
0x500A		Tablet swivel: switched to normal mode
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0x7000		Radio Switch may have changed state

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The above events are not propagated by the driver, except for legacy
compatibility purposes when hotkey_report_mode is set to 1.

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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
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0x500B		Tablet pen inserted into its storage bay
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0x500C		Tablet pen removed from its storage bay
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0x5010		Brightness level changed (newer Lenovo BIOSes)

The above events are propagated by the driver.

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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
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hotkey_report_mode cannot be changed at all, writes will return -EACCES).
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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.

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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).

623

624 625
Bluetooth
---------
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627
procfs: /proc/acpi/ibm/bluetooth
628 629
sysfs device attribute: bluetooth_enable (deprecated)
sysfs rfkill class: switch "tpacpi_bluetooth_sw"
630 631 632 633

This feature shows the presence and current state of a ThinkPad
Bluetooth device in the internal ThinkPad CDC slot.

634 635 636
If the ThinkPad supports it, the Bluetooth state is stored in NVRAM,
so it is kept across reboots and power-off.

637 638 639
Procfs notes:

If Bluetooth is installed, the following commands can be used:
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	echo enable > /proc/acpi/ibm/bluetooth
	echo disable > /proc/acpi/ibm/bluetooth

644 645 646
Sysfs notes:

	If the Bluetooth CDC card is installed, it can be enabled /
647
	disabled through the "bluetooth_enable" thinkpad-acpi device
648 649 650 651 652 653
	attribute, and its current status can also be queried.

	enable:
		0: disables Bluetooth / Bluetooth is disabled
		1: enables Bluetooth / Bluetooth is enabled.

654 655 656 657 658 659
	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.
660

661

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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
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(it simulates the behavior of Fn-F7).
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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.

703
UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000
704 705


706 707 708 709
ThinkLight control
------------------

procfs: /proc/acpi/ibm/light
710
sysfs attributes: as per LED class, for the "tpacpi::thinklight" LED
711 712

procfs notes:
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714 715 716
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:
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	echo on  > /proc/acpi/ibm/light
	echo off > /proc/acpi/ibm/light

721 722
sysfs notes:

723 724
The ThinkLight sysfs interface is documented by the LED class
documentation, in Documentation/leds-class.txt.  The ThinkLight LED name
725 726
is "tpacpi::thinklight".

727
Due to limitations in the sysfs LED class, if the status of the ThinkLight
728 729 730
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.

731

732
Docking / undocking -- /proc/acpi/ibm/dock
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------------------------------------------

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
749 750
logs:

751
	Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
752 753 754 755 756 757

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).
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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).

792

793
UltraBay eject -- /proc/acpi/ibm/bay
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------------------------------------

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
810 811
UltraBay, the following message is shown in the logs:

812
	Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
813 814

In this case, no bay-related events are generated but the eject
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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.

835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851
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.
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853 854
Note: the UltraBay eject support on the 600e/x, A22p and A3x is
EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
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856 857 858

CMOS/UCMS control
-----------------
859 860 861

procfs: /proc/acpi/ibm/cmos
sysfs device attribute: cmos_command
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863 864 865 866 867 868 869 870 871
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.
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873 874 875
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):
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877 878 879 880
	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
881
	4 - Related to "LCD brightness up" key press
882 883 884 885
	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"
886
	14 - Related to "ThinkLight" key press (toggle ThinkLight)
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888
The cmos command interface is prone to firmware split-brain problems, as
889 890
in newer ThinkPads it is just a compatibility layer.  Do not use it, it is
exported just as a debug tool.
891

892

893 894
LED control
-----------
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896
procfs: /proc/acpi/ibm/led
897
sysfs attributes: as per LED class, see below for names
898 899 900 901 902 903

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.

904 905 906 907 908 909 910 911 912 913 914
Because misuse of the LEDs could induce an unaware user to perform
dangerous actions (like undocking or ejecting a bay device while the
buses are still active), or mask an important alarm (such as a nearly
empty battery, or a broken battery), access to most LEDs is
restricted.

Unrestricted access to all LEDs requires that thinkpad-acpi be
compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled.
Distributions must never enable this option.  Individual users that
are aware of the consequences are welcome to enabling it.

915 916 917
procfs notes:

The available commands are:
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919 920 921
	echo '<LED number> on' >/proc/acpi/ibm/led
	echo '<LED number> off' >/proc/acpi/ibm/led
	echo '<LED number> blink' >/proc/acpi/ibm/led
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923
The <LED number> range is 0 to 15. The set of LEDs that can be
924 925
controlled varies from model to model. Here is the common ThinkPad
mapping:
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	0 - power
	1 - battery (orange)
	2 - battery (green)
930
	3 - UltraBase/dock
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	4 - UltraBay
932 933
	5 - UltraBase battery slot
	6 - (unknown)
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	7 - standby
935 936 937 938 939
	8 - dock status 1
	9 - dock status 2
	10, 11 - (unknown)
	12 - thinkvantage
	13, 14, 15 - (unknown)
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All of the above can be turned on and off and can be made to blink.

943 944
sysfs notes:

945
The ThinkPad LED sysfs interface is described in detail by the LED class
946 947
documentation, in Documentation/leds-class.txt.

948
The LEDs are named (in LED ID order, from 0 to 12):
949 950
"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt",
"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt",
951 952 953
"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1",
"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3",
"tpacpi::thinkvantage".
954

955
Due to limitations in the sysfs LED class, if the status of the LED
956 957 958 959 960 961 962 963 964 965 966 967
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).

968 969 970 971 972 973
LEDs that are known not to exist in a given ThinkPad model are not
made available through the sysfs interface.  If you have a dock and you
notice there are LEDs listed for your ThinkPad that do not exist (and
are not in the dock), or if you notice that there are missing LEDs,
a report to ibm-acpi-devel@lists.sourceforge.net is appreciated.

974

975 976
ACPI sounds -- /proc/acpi/ibm/beep
----------------------------------
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The BEEP method is used internally by the ACPI firmware to provide
979
audible alerts in various situations. This feature allows the same
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sounds to be triggered manually.

The commands are non-negative integer numbers:

984
	echo <number> >/proc/acpi/ibm/beep
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986 987 988
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:
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990 991
	0 - stop a sound in progress (but use 17 to stop 16)
	2 - two beeps, pause, third beep ("low battery")
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	3 - single beep
993
	4 - high, followed by low-pitched beep ("unable")
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	5 - single beep
995
	6 - very high, followed by high-pitched beep ("AC/DC")
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	7 - high-pitched beep
	9 - three short beeps
	10 - very long beep
	12 - low-pitched beep
1000 1001 1002 1003
	15 - three high-pitched beeps repeating constantly, stop with 0
	16 - one medium-pitched beep repeating constantly, stop with 17
	17 - stop 16

1004

1005 1006 1007 1008
Temperature sensors
-------------------

procfs: /proc/acpi/ibm/thermal
1009
sysfs device attributes: (hwmon "thinkpad") temp*_input
1010

1011 1012 1013 1014
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.
1015 1016

For example, on the X40, a typical output may be:
1017 1018
temperatures:   42 42 45 41 36 -128 33 -128

1019
On the T43/p, a typical output may be:
1020 1021 1022 1023 1024 1025 1026 1027 1028
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:
1029 1030

1:  CPU
1031 1032
2:  (depends on model)
3:  (depends on model)
1033
4:  GPU
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
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
1049 1050
10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
    card, under touchpad
1051
11: Power regulator, underside of system board, below F2 key
1052

1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
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

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1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078
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.


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EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090
------------------------------------------------------------------------

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:

1091
[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
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:

1122
[root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
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.)

1152

1153 1154 1155 1156 1157
LCD brightness control
----------------------

procfs: /proc/acpi/ibm/brightness
sysfs backlight device "thinkpad_screen"
1158 1159

This feature allows software control of the LCD brightness on ThinkPad
1160 1161
models which don't have a hardware brightness slider.

1162 1163 1164
It has some limitations: the LCD backlight cannot be actually turned
on or off by this interface, it just controls the backlight brightness
level.
1165 1166 1167 1168 1169 1170 1171

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.

1172 1173 1174 1175 1176 1177
For IBM ThinkPads, there are two interfaces to the firmware for direct
brightness control, EC and UCMS (or CMOS).  To select which one should be
used, use the brightness_mode module parameter: brightness_mode=1 selects
EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC
mode with NVRAM backing (so that brightness changes are remembered across
shutdown/reboot).
1178 1179 1180 1181

The driver tries to select which interface to use from a table of
defaults for each ThinkPad model.  If it makes a wrong choice, please
report this as a bug, so that we can fix it.
1182

1183 1184
Lenovo ThinkPads only support brightness_mode=2 (UCMS).

1185 1186
When display backlight brightness controls are available through the
standard ACPI interface, it is best to use it instead of this direct
1187 1188 1189
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.
1190

1191 1192
The brightness_enable module parameter can be used to control whether
the LCD brightness control feature will be enabled when available.
1193 1194 1195
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.
1196

1197 1198 1199
Procfs notes:

	The available commands are:
1200 1201 1202 1203 1204

	echo up   >/proc/acpi/ibm/brightness
	echo down >/proc/acpi/ibm/brightness
	echo 'level <level>' >/proc/acpi/ibm/brightness

1205 1206
Sysfs notes:

1207 1208
The interface is implemented through the backlight sysfs class, which is
poorly documented at this time.
1209

1210 1211
Locate the thinkpad_screen device under /sys/class/backlight, and inside
it there will be the following attributes:
1212 1213 1214 1215 1216 1217 1218 1219 1220

	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:
1221 1222 1223 1224 1225
		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.
1226 1227

	power:
1228 1229 1230 1231 1232 1233
		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.
1234

1235

1236 1237 1238 1239 1240 1241 1242 1243 1244
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.

1245

1246 1247
Volume control -- /proc/acpi/ibm/volume
---------------------------------------
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261

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.

1262 1263 1264 1265 1266
The ALSA mixer interface to this feature is still missing, but patches
to add it exist.  That problem should be addressed in the not so
distant future.


1267 1268
Fan control and monitoring: fan speed, fan enable/disable
---------------------------------------------------------
1269 1270

procfs: /proc/acpi/ibm/fan
1271
sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1272
			  pwm1_enable, fan2_input
1273
sysfs hwmon driver attributes: fan_watchdog
1274

1275 1276 1277
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.
1278

1279 1280 1281
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
1282
to work on later R, T, X and Z series ThinkPads but may show a bogus
1283 1284
value on other models.

1285 1286 1287
Some Lenovo ThinkPads support a secondary fan.  This fan cannot be
controlled separately, it shares the main fan control.

1288
Fan levels:
1289

1290 1291 1292 1293
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.
1294

1295 1296
Level "auto" means the EC changes the fan level according to some
internal algorithm, usually based on readings from the thermal sensors.
1297

1298 1299 1300 1301
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.
1302

1303 1304 1305 1306 1307
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.
1308

1309
WARNING WARNING WARNING: do not leave the fan disabled unless you are
1310 1311 1312 1313 1314
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
M
Matt LaPlante 已提交
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normal, and the EC will spin the fan up if the various thermal readings
1316 1317 1318 1319 1320 1321 1322 1323 1324
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.

1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352
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.

1353
The fan level can be controlled with the command:
1354

1355
	echo 'level <level>' > /proc/acpi/ibm/fan
1356

1357 1358 1359 1360 1361
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.
1362 1363

On the X31 and X40 (and ONLY on those models), the fan speed can be
1364
controlled to a certain degree.  Once the fan is running, it can be
1365 1366
forced to run faster or slower with the following command:

1367
	echo 'speed <speed>' > /proc/acpi/ibm/fan
1368

1369 1370 1371 1372 1373
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.
1374

1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385
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.

1386 1387 1388 1389 1390 1391 1392 1393
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.

1394 1395 1396 1397 1398 1399
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)

1400 1401 1402
	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.
1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417

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.

1418 1419 1420 1421 1422
hwmon device attribute fan2_input:
	Fan tachometer reading, in RPM, for the secondary fan.
	Available only on some ThinkPads.  If the secondary fan is
	not installed, will always read 0.

1423
hwmon driver attribute fan_watchdog:
1424 1425 1426 1427 1428 1429
	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
1430 1431
with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
would be the safest choice, though).
L
Linus Torvalds 已提交
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1433

1434 1435
WAN
---
1436 1437

procfs: /proc/acpi/ibm/wan
1438 1439
sysfs device attribute: wwan_enable (deprecated)
sysfs rfkill class: switch "tpacpi_wwan_sw"
1440

1441 1442 1443 1444 1445
This feature shows the presence and current state of the built-in
Wireless WAN device.

If the ThinkPad supports it, the WWAN state is stored in NVRAM,
so it is kept across reboots and power-off.
1446

1447 1448
It was tested on a Lenovo ThinkPad X60. It should probably work on other
ThinkPad models which come with this module installed.
1449 1450 1451 1452

Procfs notes:

If the W-WAN card is installed, the following commands can be used:
1453 1454 1455 1456

	echo enable > /proc/acpi/ibm/wan
	echo disable > /proc/acpi/ibm/wan

1457 1458 1459
Sysfs notes:

	If the W-WAN card is installed, it can be enabled /
1460
	disabled through the "wwan_enable" thinkpad-acpi device
1461 1462 1463 1464 1465 1466
	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.

1467 1468 1469 1470 1471 1472
	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.
L
Linus Torvalds 已提交
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1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
EXPERIMENTAL: UWB
-----------------

This feature is marked EXPERIMENTAL because it has not been extensively
tested and validated in various ThinkPad models yet.  The feature may not
work as expected. USE WITH CAUTION! To use this feature, you need to supply
the experimental=1 parameter when loading the module.

sysfs rfkill class: switch "tpacpi_uwb_sw"

This feature exports an rfkill controller for the UWB device, if one is
present and enabled in the BIOS.

Sysfs notes:

	rfkill controller switch "tpacpi_uwb_sw": refer to
	Documentation/rfkill.txt for details.

1493

1494 1495
Multiple Commands, Module Parameters
------------------------------------
L
Linus Torvalds 已提交
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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

1503 1504
Commands can also be specified when loading the thinkpad-acpi module,
for example:
L
Linus Torvalds 已提交
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1506
	modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
L
Linus Torvalds 已提交
1507

1508

1509 1510 1511
Enabling debugging output
-------------------------

S
Simon Arlott 已提交
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The module takes a debug parameter which can be used to selectively
1513 1514
enable various classes of debugging output, for example:

1515
	 modprobe thinkpad_acpi debug=0xffff
1516 1517 1518 1519

will enable all debugging output classes.  It takes a bitmask, so
to enable more than one output class, just add their values.

1520
	Debug bitmask		Description
1521 1522
	0x8000			Disclose PID of userspace programs
				accessing some functions of the driver
1523 1524
	0x0001			Initialization and probing
	0x0002			Removal
1525 1526
	0x0004			RF Transmitter control (RFKILL)
				(bluetooth, WWAN, UWB...)
1527
	0x0008			HKEY event interface, hotkeys
1528
	0x0010			Fan control
1529
	0x0020			Backlight brightness
1530

1531 1532
There is also a kernel build option to enable more debugging
information, which may be necessary to debug driver problems.
1533

1534 1535 1536 1537
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.

1538

1539 1540 1541 1542 1543 1544
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.
1545 1546 1547 1548 1549 1550


Sysfs interface changelog:

0x000100:	Initial sysfs support, as a single platform driver and
		device.
1551 1552
0x000200:	Hot key support for 32 hot keys, and radio slider switch
		support.
1553 1554 1555 1556
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.
1557 1558 1559 1560 1561 1562

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.
1563 1564 1565

0x020100:	Marker for thinkpad-acpi with hot key NVRAM polling
		support.  If you must, use it to know you should not
1566
		start a userspace NVRAM poller (allows to detect when
1567 1568 1569
		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
1570
		and proper hotkey_mask semantics (version 8 of the
1571 1572 1573
		NVRAM polling patch).  Some development snapshots of
		0.18 had an earlier version that did strange things
		to hotkey_mask.
1574 1575 1576

0x020200:	Add poll()/select() support to the following attributes:
		hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
1577 1578 1579 1580

0x020300:	hotkey enable/disable support removed, attributes
		hotkey_bios_enabled and hotkey_enable deprecated and
		marked for removal.
1581 1582 1583 1584

0x020400:	Marker for 16 LEDs support.  Also, LEDs that are known
		to not exist in a given model are not registered with
		the LED sysfs class anymore.