Pull thinkpad into release branch

Conflicts:

	drivers/misc/Kconfig

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 419 insertions, 166 deletions

diff --git a/Documentation/ibm-acpi.txt b/Documentation/thinkpad-acpi.txt
index 0132d363feb..2d4803359a0 100644
--- a/Documentation/ibm-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -1,16 +1,22 @@
-		    IBM ThinkPad ACPI Extras Driver
+		     ThinkPad ACPI Extras Driver
 
-                            Version 0.12
-                           17 August 2005
+                            Version 0.14
+                          April 21st, 2007
 
                Borislav Deianov <borislav@users.sf.net>
+	     Henrique de Moraes Holschuh <hmh@hmh.eng.br>
 		      http://ibm-acpi.sf.net/
 
 
-This is a Linux ACPI driver for the IBM ThinkPad laptops. It supports
-various features of these laptops which are accessible through the
-ACPI framework but not otherwise supported by the generic Linux ACPI
-drivers.
+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.
 
 
 Status
@@ -21,7 +27,7 @@ detailed description):
 
 	- Fn key combinations
 	- Bluetooth enable and disable
-	- video output switching, expansion control	
+	- video output switching, expansion control
 	- ThinkLight on and off
 	- limited docking and undocking
 	- UltraBay eject
@@ -32,7 +38,7 @@ detailed description):
 	- Experimental: embedded controller register dump
 	- LCD brightness control
 	- Volume control
-	- Experimental: fan speed, fan enable/disable
+	- Fan control and monitoring: fan speed, fan enable/disable
 	- Experimental: WAN enable and disable
 
 A compatibility table by model and feature is maintained on the web
@@ -42,6 +48,8 @@ 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
 
@@ -52,25 +60,85 @@ Installation
 ------------
 
 If you are compiling this driver as included in the Linux kernel
-sources, simply enable the CONFIG_ACPI_IBM option (Power Management /
-ACPI / IBM ThinkPad Laptop Extras).
+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 creates the /proc/acpi/ibm directory. There is a file under
-that directory for each feature described below. Note that while the
-driver is still in the alpha stage, the exact proc file format and
-commands supported by the various features is guaranteed to change
-frequently.
+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.
 
-Driver version -- /proc/acpi/ibm/driver
----------------------------------------
+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 2.6.20 this is /sys/bus/platform/drivers/thinkpad-acpi/.
+
+Sysfs device attributes are on the driver's sysfs attribute space,
+for 2.6.20 this is /sys/devices/platform/thinkpad-acpi/.
+
+Driver version
+--------------
+
+procfs: /proc/acpi/ibm/driver
+sysfs driver attribute: version
 
 The driver name and version. No commands can be written to this file.
 
-Hot keys -- /proc/acpi/ibm/hotkey
----------------------------------
+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.
+
+Hot keys
+--------
+
+procfs: /proc/acpi/ibm/hotkey
+sysfs device attribute: hotkey/*
 
 Without this driver, only the Fn-F4 key (sleep button) generates an
 ACPI event. With the driver loaded, the hotkey feature enabled and the
@@ -84,15 +152,6 @@ All labeled Fn-Fx key combinations generate distinct events. In
 addition, the lid microswitch and some docking station buttons may
 also generate such events.
 
-The following commands can be written to this file:
-
-	echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
-	echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
-	echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys
-	echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
-	... any other 4-hex-digit mask ...
-	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
-
 The bit mask allows some control over which hot keys generate ACPI
 events. 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
@@ -124,15 +183,77 @@ 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/
 
-Bluetooth -- /proc/acpi/ibm/bluetooth
--------------------------------------
+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 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys
+	echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
+	... any other 4-hex-digit mask ...
+	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
+
+sysfs notes:
+
+	The hot keys attributes are in a hotkey/ subdirectory off the
+	thinkpad device.
+
+	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
+
+	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.
+
+	enable:
+		Enables/disables the hot keys feature, and reports
+		current status of the hot keys feature.
+
+		0: disables the hot keys feature / feature disabled
+		1: enables the hot keys feature / feature enabled
+
+	mask:
+		bit mask to enable ACPI event generation for each hot
+		key (see above).  Returns the current status of the hot
+		keys mask, and allows one to modify it.
+
 
-This feature shows the presence and current state of a Bluetooth
-device. If Bluetooth is installed, the following commands can be used:
+Bluetooth
+---------
+
+procfs: /proc/acpi/ibm/bluetooth
+sysfs device attribute: bluetooth/enable
+
+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 will be probably be superseeded by the
+	generic rfkill class.
+
 Video output control -- /proc/acpi/ibm/video
 --------------------------------------------
 
@@ -209,7 +330,7 @@ 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: ibm_acpi: dock device not present
+	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
@@ -269,7 +390,7 @@ 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: ibm_acpi: bay device not present
+	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
@@ -313,23 +434,19 @@ 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 -- /proc/acpi/ibm/cmos
------------------------------------
+CMOS control
+------------
+
+procfs: /proc/acpi/ibm/cmos
+sysfs device attribute: cmos_command
 
 This feature is used internally by the ACPI firmware to control the
 ThinkLight on most newer ThinkPad models. It may also control LCD
 brightness, sounds volume and more, but only on some models.
 
-The commands are non-negative integer numbers:
-
-	echo 0 >/proc/acpi/ibm/cmos
-	echo 1 >/proc/acpi/ibm/cmos
-	echo 2 >/proc/acpi/ibm/cmos
-	...
-
-The range of valid 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):
+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 - no effect but tpb reports "Volume down"
 	1 - no effect but tpb reports "Volume up"
@@ -342,6 +459,9 @@ X40 (tpb is the ThinkPad Buttons utility):
 	13 - ThinkLight off
 	14 - no effect but tpb reports ThinkLight status change
 
+The cmos command interface is prone to firmware split-brain problems, as
+in newer ThinkPads it is just a compatibility layer.
+
 LED control -- /proc/acpi/ibm/led
 ---------------------------------
 
@@ -393,17 +513,17 @@ X40:
 	16 - one medium-pitched beep repeating constantly, stop with 17
 	17 - stop 16
 
-Temperature sensors -- /proc/acpi/ibm/thermal
----------------------------------------------
+Temperature sensors
+-------------------
+
+procfs: /proc/acpi/ibm/thermal
+sysfs device attributes: (hwmon) 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 it has experimental support for up to sixteen different
-sensors on newer ThinkPads.  Readings from sensors that are not available
-return -128.
-
-No commands can be written to this file.
+sensors on newer ThinkPads.
 
 EXPERIMENTAL: The 16-sensors feature is marked EXPERIMENTAL because the
 implementation directly accesses hardware registers and may not work as
@@ -460,6 +580,20 @@ The A31 has a very atypical layout for the thermal sensors
 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
 ------------------------------------------------------------------------
 
@@ -472,7 +606,7 @@ 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 
+[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
@@ -503,7 +637,7 @@ 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 
+[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
@@ -533,19 +667,59 @@ 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 -- /proc/acpi/ibm/brightness
----------------------------------------------------
+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. The available
-commands are:
+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.
+
+The backlight control has eight levels, ranging from 0 to 7.  Some of the
+levels may not be distinct.
+
+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
 
-The <level> number range is 0 to 7, although not all of them may be
-distinct. The current brightness level is shown in the file.
+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.
+
 
 Volume control -- /proc/acpi/ibm/volume
 ---------------------------------------
@@ -563,41 +737,42 @@ 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.
 
-EXPERIMENTAL: fan speed, fan enable/disable -- /proc/acpi/ibm/fan
------------------------------------------------------------------
+Fan control and monitoring: fan speed, fan enable/disable
+---------------------------------------------------------
 
-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.
+procfs: /proc/acpi/ibm/fan
+sysfs device attributes: (hwmon) fan_input, pwm1, pwm1_enable
+
+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 and X series ThinkPads but may show a bogus
+to work on later R, T, X and Z series ThinkPads but may show a bogus
 value on other models.
 
-Most ThinkPad fans work in "levels".  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.  Level "disengaged" means 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.
+Fan levels:
 
-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.
+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.
 
-The fan may be enabled or disabled with the following commands:
+Level "auto" means the EC changes the fan level according to some
+internal algorithm, usually based on readings from the thermal sensors.
 
-	echo enable  >/proc/acpi/ibm/fan
-	echo disable >/proc/acpi/ibm/fan
+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.
 
-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 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
@@ -615,46 +790,146 @@ 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/thermal
+	echo 'level <level>' > /proc/acpi/ibm/fan
 
-Where <level> is an integer from 0 to 7, or one of the words "auto"
-or "disengaged" (without the quotes).  Not all ThinkPads support the
-"auto" and "disengaged" levels.
+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
+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/thermal
+	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.
+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.
 
-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 ibm-acpi.
+To program the safety watchdog, use the "watchdog" command.
 
-EXPERIMENTAL: WAN -- /proc/acpi/ibm/wan
----------------------------------------
+	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.
+
+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).
+
+
+EXPERIMENTAL: WAN
+-----------------
+
+procfs: /proc/acpi/ibm/wan
+sysfs device attribute: wwan/enable
 
 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 shows the presence and current state of a WAN (Sierra
-Wireless EV-DO) device. If WAN is installed, the following commands can
-be used:
+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
 
-It was tested on a Lenovo Thinkpad X60. It should probably work on other
-Thinkpad models which come with this module installed.
+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 will be probably be superseeded by the
+	generic rfkill class.
 
 Multiple Commands, Module Parameters
 ------------------------------------
@@ -665,64 +940,42 @@ 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 ibm_acpi module, for
-example:
-
-	modprobe ibm_acpi hotkey=enable,0xffff video=auto_disable
-
-The ibm-acpi kernel driver can be programmed to revert the fan level
-to a safe setting if userspace does not issue one of the fan commands:
-"enable", "disable", "level" or "watchdog" within a configurable
-ammount of time.  To do this, use the "watchdog" command.
-
-	echo 'watchdog <interval>' > /proc/acpi/ibm/fan
-
-Interval is the ammount of time in seconds to wait for one of the
-above mentioned fan commands before reseting the fan level to a safe
-one.  If set to zero, the watchdog is disabled (default).  When the
-watchdog timer runs out, it does the exact equivalent of the "enable"
-fan command.
-
-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" fan
-commands.
-
-
-Example Configuration
----------------------
-
-The ACPI support in the kernel is intended to be used in conjunction
-with a user-space daemon, acpid. The configuration files for this
-daemon control what actions are taken in response to various ACPI
-events. An example set of configuration files are included in the
-config/ directory of the tarball package available on the web
-site. Note that these are provided for illustration purposes only and
-may need to be adapted to your particular setup.
-
-The following utility scripts are used by the example action
-scripts (included with ibm-acpi for completeness):
-
-	/usr/local/sbin/idectl -- from the hdparm source distribution,
-		see http://www.ibiblio.org/pub/Linux/system/hardware
-	/usr/local/sbin/laptop_mode -- from the Linux kernel source
-		distribution, see Documentation/laptop-mode.txt
-	/sbin/service -- comes with Redhat/Fedora distributions
-	/usr/sbin/hibernate -- from the Software Suspend 2 distribution,
-		see http://softwaresuspend.berlios.de/
-
-Toan T Nguyen <ntt@physics.ucla.edu> notes that Suse uses the
-powersave program to suspend ('powersave --suspend-to-ram') or
-hibernate ('powersave --suspend-to-disk'). This means that the
-hibernate script is not needed on that distribution.
-
-Henrik Brix Andersen <brix@gentoo.org> has written a Gentoo ACPI event
-handler script for the X31. You can get the latest version from
-http://dev.gentoo.org/~brix/files/x31.sh
-
-David Schweikert <dws@ee.eth.ch> has written an alternative blank.sh
-script which works on Debian systems. This scripts has now been
-extended to also work on Fedora systems and included as the default
-blank.sh in the distribution.
+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 paramater which can be used to selectively
+enable various classes of debugging output, for example:
+
+	 modprobe ibm_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.