[PATCH 0/3] acpi: improvements for Documentation/thermal/sysfs-api.txt

[PATCH 0/3] acpi: improvements for Documentation/thermal/sysfs-api.txt

[Frans Pop]

(Resend adding CC to lkml.)

Here's three patches for your consideration:
1/3: reformat for improved readability
2/3: document passive attribute for thermal zones
3/3: move to acpi directory

The first patch mainly reduces the width of the text to make it fit better 
in normal windows, but also has a number of consistency improvements.

The second patch is the only one that really changes content. It documents 
an attribute that is currently missing in the document.
Note that I've not checked whether the description of the API still 
matches the driver code.

The third patch moves the document to an IMO more logical location and
removes the thermal directory from the top Documentation level.

Cheers,
FJP

[PATCH 1/3] acpi: thermal/sysfs-api.txt: reformat for improved readability

[Frans Pop]

The document currently uses large indentations which make the text
too wide for easy readability. Also improve general consistency.

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 70d68ce..48e9c5c 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -1,5 +1,5 @@
 Generic Thermal Sysfs driver How To
-=========================
+===================================
 
 Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
 
@@ -10,20 +10,20 @@ Copyright (c)  2008 Intel Corporation
 
 0. Introduction
 
-The generic thermal sysfs provides a set of interfaces for thermal zone devices (sensors)
-and thermal cooling devices (fan, processor...) to register with the thermal management
-solution and to be a part of it.
+The generic thermal sysfs provides a set of interfaces for thermal zone
+devices (sensors) and thermal cooling devices (fan, processor...) to register
+with the thermal management solution and to be a part of it.
 
-This how-to focuses on enabling new thermal zone and cooling devices to participate
-in thermal management.
-This solution is platform independent and any type of thermal zone devices and
-cooling devices should be able to make use of the infrastructure.
+This how-to focuses on enabling new thermal zone and cooling devices to
+participate in thermal management.
+This solution is platform independent and any type of thermal zone devices
+and cooling devices should be able to make use of the infrastructure.
 
-The main task of the thermal sysfs driver is to expose thermal zone attributes as well
-as cooling device attributes to the user space.
-An intelligent thermal management application can make decisions based on inputs
-from thermal zone attributes (the current temperature and trip point temperature)
-and throttle appropriate devices.
+The main task of the thermal sysfs driver is to expose thermal zone attributes
+as well as cooling device attributes to the user space.
+An intelligent thermal management application can make decisions based on
+inputs from thermal zone attributes (the current temperature and trip point
+temperature) and throttle appropriate devices.
 
 [0-*]	denotes any positive number starting from 0
 [1-*]	denotes any positive number starting from 1
@@ -31,77 +31,77 @@ and throttle appropriate devices.
 1. thermal sysfs driver interface functions
 
 1.1 thermal zone device interface
-1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name, int trips,
-				void *devdata, struct thermal_zone_device_ops *ops)
-
-	This interface function adds a new thermal zone device (sensor) to
-	/sys/class/thermal folder as thermal_zone[0-*].
-	It tries to bind all the thermal cooling devices registered at the same time.
-
-	name: the thermal zone name.
-	trips: the total number of trip points this thermal zone supports.
-	devdata: device private data
-	ops: thermal zone device call-backs.
-		.bind: bind the thermal zone device with a thermal cooling device.
-		.unbind: unbind the thermal zone device with a thermal cooling device.
-		.get_temp: get the current temperature of the thermal zone.
-		.get_mode: get the current mode (user/kernel) of the thermal zone.
-			   "kernel" means thermal management is done in kernel.
-			   "user" will prevent kernel thermal driver actions upon trip points
-			   so that user applications can take charge of thermal management.
-		.set_mode: set the mode (user/kernel) of the thermal zone.
-		.get_trip_type: get the type of certain trip point.
-		.get_trip_temp: get the temperature above which the certain trip point
-				will be fired.
+1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
+		int trips, void *devdata, struct thermal_zone_device_ops *ops)
+
+    This interface function adds a new thermal zone device (sensor) to
+    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
+    thermal cooling devices registered at the same time.
+
+    name: the thermal zone name.
+    trips: the total number of trip points this thermal zone supports.
+    devdata: device private data
+    ops: thermal zone device call-backs.
+	.bind: bind the thermal zone device with a thermal cooling device.
+	.unbind: unbind the thermal zone device with a thermal cooling device.
+	.get_temp: get the current temperature of the thermal zone.
+	.get_mode: get the current mode (user/kernel) of the thermal zone.
+	    - "kernel" means thermal management is done in kernel.
+	    - "user" will prevent kernel thermal driver actions upon trip points
+	      so that user applications can take charge of thermal management.
+	.set_mode: set the mode (user/kernel) of the thermal zone.
+	.get_trip_type: get the type of certain trip point.
+	.get_trip_temp: get the temperature above which the certain trip point
+			will be fired.
 
 1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 
-	This interface function removes the thermal zone device.
-	It deletes the corresponding entry form /sys/class/thermal folder and unbind all
-	the thermal cooling devices it uses.
+    This interface function removes the thermal zone device.
+    It deletes the corresponding entry form /sys/class/thermal folder and
+    unbind all the thermal cooling devices it uses.
 
 1.2 thermal cooling device interface
 1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
-					void *devdata, struct thermal_cooling_device_ops *)
-
-	This interface function adds a new thermal cooling device (fan/processor/...) to
-	/sys/class/thermal/ folder as cooling_device[0-*].
-	It tries to bind itself to all the thermal zone devices register at the same time.
-	name: the cooling device name.
-	devdata: device private data.
-	ops: thermal cooling devices call-backs.
-		.get_max_state: get the Maximum throttle state of the cooling device.
-		.get_cur_state: get the Current throttle state of the cooling device.
-		.set_cur_state: set the Current throttle state of the cooling device.
+		void *devdata, struct thermal_cooling_device_ops *)
+
+    This interface function adds a new thermal cooling device (fan/processor/...)
+    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+    to all the thermal zone devices register at the same time.
+    name: the cooling device name.
+    devdata: device private data.
+    ops: thermal cooling devices call-backs.
+	.get_max_state: get the Maximum throttle state of the cooling device.
+	.get_cur_state: get the Current throttle state of the cooling device.
+	.set_cur_state: set the Current throttle state of the cooling device.
 
 1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
 
-	This interface function remove the thermal cooling device.
-	It deletes the corresponding entry form /sys/class/thermal folder and unbind
-	itself from all	the thermal zone devices using it.
+    This interface function remove the thermal cooling device.
+    It deletes the corresponding entry form /sys/class/thermal folder and
+    unbind itself from all the thermal zone devices using it.
 
 1.3 interface for binding a thermal zone device with a thermal cooling device
 1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
-			int trip, struct thermal_cooling_device *cdev);
+		int trip, struct thermal_cooling_device *cdev);
 
-	This interface function bind a thermal cooling device to the certain trip point
-	of a thermal zone device.
-	This function is usually called in the thermal zone device .bind callback.
-	tz: the thermal zone device
-	cdev: thermal cooling device
-	trip: indicates which trip point the cooling devices is associated with
-		 in this thermal zone.
+    This interface function bind a thermal cooling device to the certain trip
+    point of a thermal zone device.
+    This function is usually called in the thermal zone device .bind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point the cooling devices is associated with
+	  in this thermal zone.
 
 1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
-				int trip, struct thermal_cooling_device *cdev);
+		int trip, struct thermal_cooling_device *cdev);
 
-	This interface function unbind a thermal cooling device from the certain trip point
-	of a thermal zone device.
-	This function is usually called in the thermal zone device .unbind callback.
-	tz: the thermal zone device
-	cdev: thermal cooling device
-	trip: indicates which trip point the cooling devices is associated with
-		in this thermal zone.
+    This interface function unbind a thermal cooling device from the certain
+    trip point of a thermal zone device. This function is usually called in
+    the thermal zone device .unbind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point the cooling devices is associated with
+	  in this thermal zone.
 
 2. sysfs attributes structure
 
@@ -114,153 +114,157 @@ if hwmon is compiled in or built as a module.
 
 Thermal zone device sys I/F, created once it's registered:
 /sys/class/thermal/thermal_zone[0-*]:
-	|-----type:			Type of the thermal zone
-	|-----temp:			Current temperature
-	|-----mode:			Working mode of the thermal zone
-	|-----trip_point_[0-*]_temp:	Trip point temperature
-	|-----trip_point_[0-*]_type:	Trip point type
+    |---type:			Type of the thermal zone
+    |---temp:			Current temperature
+    |---mode:			Working mode of the thermal zone
+    |---trip_point_[0-*]_temp:	Trip point temperature
+    |---trip_point_[0-*]_type:	Trip point type
 
 Thermal cooling device sys I/F, created once it's registered:
 /sys/class/thermal/cooling_device[0-*]:
-	|-----type :			Type of the cooling device(processor/fan/...)
-	|-----max_state:		Maximum cooling state of the cooling device
-	|-----cur_state:		Current cooling state of the cooling device
+    |---type:			Type of the cooling device(processor/fan/...)
+    |---max_state:		Maximum cooling state of the cooling device
+    |---cur_state:		Current cooling state of the cooling device
 
 
-These two dynamic attributes are created/removed in pairs.
-They represent the relationship between a thermal zone and its associated cooling device.
-They are created/removed for each
-thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device successful execution.
+Then next two dynamic attributes are created/removed in pairs. They represent
+the relationship between a thermal zone and its associated cooling device.
+They are created/removed for each successful execution of
+thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
 
-/sys/class/thermal/thermal_zone[0-*]
-	|-----cdev[0-*]:		The [0-*]th cooling device in the current thermal zone
-	|-----cdev[0-*]_trip_point:	Trip point that cdev[0-*] is associated with
+/sys/class/thermal/thermal_zone[0-*]:
+    |---cdev[0-*]:		[0-*]th cooling device in current thermal zone
+    |---cdev[0-*]_trip_point:	Trip point that cdev[0-*] is associated with
 
 Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
-the generic thermal driver also creates a hwmon sysfs I/F for each _type_ of
-thermal zone device. E.g. the generic thermal driver registers one hwmon class device
-and build the associated hwmon sysfs I/F for all the registered ACPI thermal zones.
+the generic thermal driver also creates a hwmon sysfs I/F for each _type_
+of thermal zone device. E.g. the generic thermal driver registers one hwmon
+class device and build the associated hwmon sysfs I/F for all the registered
+ACPI thermal zones.
+
 /sys/class/hwmon/hwmon[0-*]:
-	|-----name:			The type of the thermal zone devices.
-	|-----temp[1-*]_input:		The current temperature of thermal zone [1-*].
-	|-----temp[1-*]_critical:	The critical trip point of thermal zone [1-*].
+    |---name:			The type of the thermal zone devices
+    |---temp[1-*]_input:	The current temperature of thermal zone [1-*]
+    |---temp[1-*]_critical:	The critical trip point of thermal zone [1-*]
+
 Please read Documentation/hwmon/sysfs-interface for additional information.
 
 ***************************
 * Thermal zone attributes *
 ***************************
 
-type				Strings which represent the thermal zone type.
-				This is given by thermal zone driver as part of registration.
-				Eg: "acpitz" indicates it's an ACPI thermal device.
-				In order to keep it consistent with hwmon sys attribute,
-				this should be a short, lowercase string,
-				not containing spaces nor dashes.
-				RO
-				Required
-
-temp				Current temperature as reported by thermal zone (sensor)
-				Unit: millidegree Celsius
-				RO
-				Required
-
-mode				One of the predefined values in [kernel, user]
-				This file gives information about the algorithm
-				that is currently managing the thermal zone.
-				It can be either default kernel based algorithm
-				or user space application.
-				RW
-				Optional
-				kernel	= Thermal management in kernel thermal zone driver.
-				user	= Preventing kernel thermal zone driver actions upon
-					  trip points so that user application can take full
-					  charge of the thermal management.
-
-trip_point_[0-*]_temp		The temperature above which trip point will be fired
-				Unit: millidegree Celsius
-				RO
-				Optional
-
-trip_point_[0-*]_type 		Strings which indicate the type of the trip point
-				E.g. it can be one of critical, hot, passive,
-				    active[0-*] for ACPI thermal zone.
-				RO
-				Optional
-
-cdev[0-*]			Sysfs link to the thermal cooling device node where the sys I/F
-				for cooling device throttling control represents.
-				RO
-				Optional
-
-cdev[0-*]_trip_point		The trip point with which cdev[0-*] is associated in this thermal zone
-				-1 means the cooling device is not associated with any trip point.
-				RO
-				Optional
-
-******************************
-* Cooling device  attributes *
-******************************
-
-type				String which represents the type of device
-				eg: For generic ACPI: this should be "Fan",
-				"Processor" or "LCD"
-				eg. For memory controller device on intel_menlow platform:
-				this should be "Memory controller"
-				RO
-				Required
-
-max_state			The maximum permissible cooling state of this cooling device.
-				RO
-				Required
-
-cur_state			The current cooling state of this cooling device.
-				the value can any integer numbers between 0 and max_state,
-				cur_state == 0 means no cooling
-				cur_state == max_state means the maximum cooling.
-				RW
-				Required
+type
+	Strings which represent the thermal zone type.
+	This is given by thermal zone driver as part of registration.
+	E.g: "acpitz" indicates it's an ACPI thermal device.
+	In order to keep it consistent with hwmon sys attribute; this should
+ 	be a short, lowercase string, not containing spaces nor dashes.
+	RO, Required
+
+temp
+	Current temperature as reported by thermal zone (sensor).
+	Unit: millidegree Celsius
+	RO, Required
+
+mode
+	One of the predefined values in [kernel, user].
+	This file gives information about the algorithm that is currently
+	managing the thermal zone. It can be either default kernel based
+	algorithm or user space application.
+	kernel	= Thermal management in kernel thermal zone driver.
+	user	= Preventing kernel thermal zone driver actions upon
+		  trip points so that user application can take full
+		  charge of the thermal management.
+	RW, Optional
+
+trip_point_[0-*]_temp
+	The temperature above which trip point will be fired.
+	Unit: millidegree Celsius
+	RO, Optional
+
+trip_point_[0-*]_type
+	Strings which indicate the type of the trip point.
+	E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
+	thermal zone.
+	RO, Optional
+
+cdev[0-*]
+	Sysfs link to the thermal cooling device node where the sys I/F
+	for cooling device throttling control represents.
+	RO, Optional
+
+cdev[0-*]_trip_point
+	The trip point with which cdev[0-*] is associated in this thermal
+	zone; -1 means the cooling device is not associated with any trip
+	point.
+	RO, Optional
+
+*****************************
+* Cooling device attributes *
+*****************************
+
+type
+	String which represents the type of device, e.g:
+	- for generic ACPI: should be "Fan", "Processor" or "LCD"
+	- for memory controller device on intel_menlow platform:
+	  should be "Memory controller".
+	RO, Required
+
+max_state
+	The maximum permissible cooling state of this cooling device.
+	RO, Required
+
+cur_state
+	The current cooling state of this cooling device.
+	The value can any integer numbers between 0 and max_state:
+	- cur_state == 0 means no cooling
+	- cur_state == max_state means the maximum cooling.
+	RW, Required
 
 3. A simple implementation
 
-ACPI thermal zone may support multiple trip points like critical/hot/passive/active.
-If an ACPI thermal zone supports critical, passive, active[0] and active[1] at the same time,
-it may register itself as a thermal_zone_device (thermal_zone1) with 4 trip points in all.
-It has one processor and one fan, which are both registered as thermal_cooling_device.
-If the processor is listed in _PSL method, and the fan is listed in _AL0 method,
-the sys I/F structure will be built like this:
+ACPI thermal zone may support multiple trip points like critical, hot,
+passive, active. If an ACPI thermal zone supports critical, passive,
+active[0] and active[1] at the same time, it may register itself as a
+thermal_zone_device (thermal_zone1) with 4 trip points in all.
+It has one processor and one fan, which are both registered as
+thermal_cooling_device.
+
+If the processor is listed in _PSL method, and the fan is listed in _AL0
+method, the sys I/F structure will be built like this:
 
 /sys/class/thermal:
 
 |thermal_zone1:
-	|-----type:			acpitz
-	|-----temp:			37000
-	|-----mode:			kernel
-	|-----trip_point_0_temp:	100000
-	|-----trip_point_0_type:	critical
-	|-----trip_point_1_temp:	80000
-	|-----trip_point_1_type:	passive
-	|-----trip_point_2_temp:	70000
-	|-----trip_point_2_type:	active0
-	|-----trip_point_3_temp:	60000
-	|-----trip_point_3_type:	active1
-	|-----cdev0:			--->/sys/class/thermal/cooling_device0
-	|-----cdev0_trip_point:		1	/* cdev0 can be used for passive */
-	|-----cdev1:			--->/sys/class/thermal/cooling_device3
-	|-----cdev1_trip_point:		2	/* cdev1 can be used for active[0]*/
+    |---type:			acpitz
+    |---temp:			37000
+    |---mode:			kernel
+    |---trip_point_0_temp:	100000
+    |---trip_point_0_type:	critical
+    |---trip_point_1_temp:	80000
+    |---trip_point_1_type:	passive
+    |---trip_point_2_temp:	70000
+    |---trip_point_2_type:	active0
+    |---trip_point_3_temp:	60000
+    |---trip_point_3_type:	active1
+    |---cdev0:			--->/sys/class/thermal/cooling_device0
+    |---cdev0_trip_point:	1	/* cdev0 can be used for passive */
+    |---cdev1:			--->/sys/class/thermal/cooling_device3
+    |---cdev1_trip_point:	2	/* cdev1 can be used for active[0]*/
 
 |cooling_device0:
-	|-----type:			Processor
-	|-----max_state:		8
-	|-----cur_state:		0
+    |---type:			Processor
+    |---max_state:		8
+    |---cur_state:		0
 
 |cooling_device3:
-	|-----type:			Fan
-	|-----max_state:		2
-	|-----cur_state:		0
+    |---type:			Fan
+    |---max_state:		2
+    |---cur_state:		0
 
 /sys/class/hwmon:
 
 |hwmon0:
-	|-----name:			acpitz
-	|-----temp1_input:		37000
-	|-----temp1_crit:		100000
+    |---name:			acpitz
+    |---temp1_input:		37000
+    |---temp1_crit:		100000

[PATCH 2/3] acpi: thermal/sysfs-api.txt: document passive attribute for thermal zones

[Frans Pop]

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 48e9c5c..52b63c4 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -3,7 +3,7 @@ Generic Thermal Sysfs driver How To
 
 Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
 
-Updated: 2 January 2008
+Updated: 21 August 2009
 
 Copyright (c)  2008 Intel Corporation
 
@@ -199,6 +199,16 @@ cdev[0-*]_trip_point
 	point.
 	RO, Optional
 
+passive
+	Attribute is only present for zones which do not have a passive
+	cooling policy (_PSV) defined in ACPI. Default is zero and can be
+	set to a temperature (in millidegrees) to enable a passive trip
+	point for the zone. Activation is done by polling (default interval:
+	10 seconds); the polling interval can be set in
+	/proc/acpi/thermal/TZN/polling_frequency.
+	Unit: millidegree Celsius
+	RW, Optional
+
 *****************************
 * Cooling device attributes *
 *****************************
@@ -230,8 +240,9 @@ thermal_zone_device (thermal_zone1) with 4 trip points in all.
 It has one processor and one fan, which are both registered as
 thermal_cooling_device.
 
-If the processor is listed in _PSL method, and the fan is listed in _AL0
-method, the sys I/F structure will be built like this:
+If the processor is listed in _PSL method, the fan is listed in _AL0
+method, and the zone has a _PSV method, the sys I/F structure will be
+built like this:
 
 /sys/class/thermal:
 

Re: [PATCH 2/3,v2] acpi: thermal/sysfs-api.txt: document passive attribute for thermal zones

[Frans Pop]

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
---

While working on some further patches I discovered that polling_delay does
not actually determine the polling interval for a forced passive trip
point. Instead a hardcoded interval of 1 second is used (passive_delay).

I also saw that the thermal_sys driver is somewhat independent of ACPI,
so the third patch in the series may not be appropriate.

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 48e9c5c..f6b3743 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -3,7 +3,7 @@ Generic Thermal Sysfs driver How To
 
 Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
 
-Updated: 2 January 2008
+Updated: 21 August 2009
 
 Copyright (c)  2008 Intel Corporation
 
@@ -199,6 +199,15 @@ cdev[0-*]_trip_point
 	point.
 	RO, Optional
 
+passive
+	Attribute is only present for zones which do not have a passive
+	cooling policy (_PSV) defined in ACPI. Default is zero and can be
+	set to a temperature (in millidegrees) to enable a passive trip
+	point for the zone. Activation is done by polling with an interval
+	of 1 second.
+	Unit: millidegrees Celsius
+	RW, Optional
+
 *****************************
 * Cooling device attributes *
 *****************************
@@ -230,8 +239,9 @@ thermal_zone_device (thermal_zone1) with 4 trip points in all.
 It has one processor and one fan, which are both registered as
 thermal_cooling_device.
 
-If the processor is listed in _PSL method, and the fan is listed in _AL0
-method, the sys I/F structure will be built like this:
+If the processor is listed in _PSL method, the fan is listed in _AL0
+method, and the zone has a _PSV method, the sys I/F structure will be
+built like this:
 
 /sys/class/thermal:
 

[PATCH 3/3] acpi: thermal/sysfs-api.txt: move to acpi directory

[Frans Pop]

It is a more logical place to look and reduces the clutter in
the Documentation directory as the thermal directory is now empty
and can be removed.

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>

diff --git a/Documentation/acpi/thermal-sysfs-api.txt b/Documentation/acpi/thermal-sysfs-api.txt
new file mode 100644
index 0000000..52b63c4
--- /dev/null
+++ b/Documentation/acpi/thermal-sysfs-api.txt
@@ -0,0 +1,281 @@
+Generic Thermal Sysfs driver How To
+===================================
+
+Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
+
+Updated: 21 August 2009
+
+Copyright (c)  2008 Intel Corporation
+
+
+0. Introduction
+
+The generic thermal sysfs provides a set of interfaces for thermal zone
+devices (sensors) and thermal cooling devices (fan, processor...) to register
+with the thermal management solution and to be a part of it.
+
+This how-to focuses on enabling new thermal zone and cooling devices to
+participate in thermal management.
+This solution is platform independent and any type of thermal zone devices
+and cooling devices should be able to make use of the infrastructure.
+
+The main task of the thermal sysfs driver is to expose thermal zone attributes
+as well as cooling device attributes to the user space.
+An intelligent thermal management application can make decisions based on
+inputs from thermal zone attributes (the current temperature and trip point
+temperature) and throttle appropriate devices.
+
+[0-*]	denotes any positive number starting from 0
+[1-*]	denotes any positive number starting from 1
+
+1. thermal sysfs driver interface functions
+
+1.1 thermal zone device interface
+1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
+		int trips, void *devdata, struct thermal_zone_device_ops *ops)
+
+    This interface function adds a new thermal zone device (sensor) to
+    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
+    thermal cooling devices registered at the same time.
+
+    name: the thermal zone name.
+    trips: the total number of trip points this thermal zone supports.
+    devdata: device private data
+    ops: thermal zone device call-backs.
+	.bind: bind the thermal zone device with a thermal cooling device.
+	.unbind: unbind the thermal zone device with a thermal cooling device.
+	.get_temp: get the current temperature of the thermal zone.
+	.get_mode: get the current mode (user/kernel) of the thermal zone.
+	    - "kernel" means thermal management is done in kernel.
+	    - "user" will prevent kernel thermal driver actions upon trip points
+	      so that user applications can take charge of thermal management.
+	.set_mode: set the mode (user/kernel) of the thermal zone.
+	.get_trip_type: get the type of certain trip point.
+	.get_trip_temp: get the temperature above which the certain trip point
+			will be fired.
+
+1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
+
+    This interface function removes the thermal zone device.
+    It deletes the corresponding entry form /sys/class/thermal folder and
+    unbind all the thermal cooling devices it uses.
+
+1.2 thermal cooling device interface
+1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
+		void *devdata, struct thermal_cooling_device_ops *)
+
+    This interface function adds a new thermal cooling device (fan/processor/...)
+    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+    to all the thermal zone devices register at the same time.
+    name: the cooling device name.
+    devdata: device private data.
+    ops: thermal cooling devices call-backs.
+	.get_max_state: get the Maximum throttle state of the cooling device.
+	.get_cur_state: get the Current throttle state of the cooling device.
+	.set_cur_state: set the Current throttle state of the cooling device.
+
+1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
+
+    This interface function remove the thermal cooling device.
+    It deletes the corresponding entry form /sys/class/thermal folder and
+    unbind itself from all the thermal zone devices using it.
+
+1.3 interface for binding a thermal zone device with a thermal cooling device
+1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
+		int trip, struct thermal_cooling_device *cdev);
+
+    This interface function bind a thermal cooling device to the certain trip
+    point of a thermal zone device.
+    This function is usually called in the thermal zone device .bind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point the cooling devices is associated with
+	  in this thermal zone.
+
+1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
+		int trip, struct thermal_cooling_device *cdev);
+
+    This interface function unbind a thermal cooling device from the certain
+    trip point of a thermal zone device. This function is usually called in
+    the thermal zone device .unbind callback.
+    tz: the thermal zone device
+    cdev: thermal cooling device
+    trip: indicates which trip point the cooling devices is associated with
+	  in this thermal zone.
+
+2. sysfs attributes structure
+
+RO	read only value
+RW	read/write value
+
+Thermal sysfs attributes will be represented under /sys/class/thermal.
+Hwmon sysfs I/F extension is also available under /sys/class/hwmon
+if hwmon is compiled in or built as a module.
+
+Thermal zone device sys I/F, created once it's registered:
+/sys/class/thermal/thermal_zone[0-*]:
+    |---type:			Type of the thermal zone
+    |---temp:			Current temperature
+    |---mode:			Working mode of the thermal zone
+    |---trip_point_[0-*]_temp:	Trip point temperature
+    |---trip_point_[0-*]_type:	Trip point type
+
+Thermal cooling device sys I/F, created once it's registered:
+/sys/class/thermal/cooling_device[0-*]:
+    |---type:			Type of the cooling device(processor/fan/...)
+    |---max_state:		Maximum cooling state of the cooling device
+    |---cur_state:		Current cooling state of the cooling device
+
+
+Then next two dynamic attributes are created/removed in pairs. They represent
+the relationship between a thermal zone and its associated cooling device.
+They are created/removed for each successful execution of
+thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
+
+/sys/class/thermal/thermal_zone[0-*]:
+    |---cdev[0-*]:		[0-*]th cooling device in current thermal zone
+    |---cdev[0-*]_trip_point:	Trip point that cdev[0-*] is associated with
+
+Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
+the generic thermal driver also creates a hwmon sysfs I/F for each _type_
+of thermal zone device. E.g. the generic thermal driver registers one hwmon
+class device and build the associated hwmon sysfs I/F for all the registered
+ACPI thermal zones.
+
+/sys/class/hwmon/hwmon[0-*]:
+    |---name:			The type of the thermal zone devices
+    |---temp[1-*]_input:	The current temperature of thermal zone [1-*]
+    |---temp[1-*]_critical:	The critical trip point of thermal zone [1-*]
+
+Please read Documentation/hwmon/sysfs-interface for additional information.
+
+***************************
+* Thermal zone attributes *
+***************************
+
+type
+	Strings which represent the thermal zone type.
+	This is given by thermal zone driver as part of registration.
+	E.g: "acpitz" indicates it's an ACPI thermal device.
+	In order to keep it consistent with hwmon sys attribute; this should
+ 	be a short, lowercase string, not containing spaces nor dashes.
+	RO, Required
+
+temp
+	Current temperature as reported by thermal zone (sensor).
+	Unit: millidegree Celsius
+	RO, Required
+
+mode
+	One of the predefined values in [kernel, user].
+	This file gives information about the algorithm that is currently
+	managing the thermal zone. It can be either default kernel based
+	algorithm or user space application.
+	kernel	= Thermal management in kernel thermal zone driver.
+	user	= Preventing kernel thermal zone driver actions upon
+		  trip points so that user application can take full
+		  charge of the thermal management.
+	RW, Optional
+
+trip_point_[0-*]_temp
+	The temperature above which trip point will be fired.
+	Unit: millidegree Celsius
+	RO, Optional
+
+trip_point_[0-*]_type
+	Strings which indicate the type of the trip point.
+	E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
+	thermal zone.
+	RO, Optional
+
+cdev[0-*]
+	Sysfs link to the thermal cooling device node where the sys I/F
+	for cooling device throttling control represents.
+	RO, Optional
+
+cdev[0-*]_trip_point
+	The trip point with which cdev[0-*] is associated in this thermal
+	zone; -1 means the cooling device is not associated with any trip
+	point.
+	RO, Optional
+
+passive
+	Attribute is only present for zones which do not have a passive
+	cooling policy (_PSV) defined in ACPI. Default is zero and can be
+	set to a temperature (in millidegrees) to enable a passive trip
+	point for the zone. Activation is done by polling (default interval:
+	10 seconds); the polling interval can be set in
+	/proc/acpi/thermal/TZN/polling_frequency.
+	Unit: millidegree Celsius
+	RW, Optional
+
+*****************************
+* Cooling device attributes *
+*****************************
+
+type
+	String which represents the type of device, e.g:
+	- for generic ACPI: should be "Fan", "Processor" or "LCD"
+	- for memory controller device on intel_menlow platform:
+	  should be "Memory controller".
+	RO, Required
+
+max_state
+	The maximum permissible cooling state of this cooling device.
+	RO, Required
+
+cur_state
+	The current cooling state of this cooling device.
+	The value can any integer numbers between 0 and max_state:
+	- cur_state == 0 means no cooling
+	- cur_state == max_state means the maximum cooling.
+	RW, Required
+
+3. A simple implementation
+
+ACPI thermal zone may support multiple trip points like critical, hot,
+passive, active. If an ACPI thermal zone supports critical, passive,
+active[0] and active[1] at the same time, it may register itself as a
+thermal_zone_device (thermal_zone1) with 4 trip points in all.
+It has one processor and one fan, which are both registered as
+thermal_cooling_device.
+
+If the processor is listed in _PSL method, the fan is listed in _AL0
+method, and the zone hase a _PSV method, the sys I/F structure will be
+built like this:
+
+/sys/class/thermal:
+
+|thermal_zone1:
+    |---type:			acpitz
+    |---temp:			37000
+    |---mode:			kernel
+    |---trip_point_0_temp:	100000
+    |---trip_point_0_type:	critical
+    |---trip_point_1_temp:	80000
+    |---trip_point_1_type:	passive
+    |---trip_point_2_temp:	70000
+    |---trip_point_2_type:	active0
+    |---trip_point_3_temp:	60000
+    |---trip_point_3_type:	active1
+    |---cdev0:			--->/sys/class/thermal/cooling_device0
+    |---cdev0_trip_point:	1	/* cdev0 can be used for passive */
+    |---cdev1:			--->/sys/class/thermal/cooling_device3
+    |---cdev1_trip_point:	2	/* cdev1 can be used for active[0]*/
+
+|cooling_device0:
+    |---type:			Processor
+    |---max_state:		8
+    |---cur_state:		0
+
+|cooling_device3:
+    |---type:			Fan
+    |---max_state:		2
+    |---cur_state:		0
+
+/sys/class/hwmon:
+
+|hwmon0:
+    |---name:			acpitz
+    |---temp1_input:		37000
+    |---temp1_crit:		100000
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
deleted file mode 100644
index 52b63c4..0000000
--- a/Documentation/thermal/sysfs-api.txt
+++ /dev/null
@@ -1,281 +0,0 @@
-Generic Thermal Sysfs driver How To
-===================================
-
-Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
-
-Updated: 21 August 2009
-
-Copyright (c)  2008 Intel Corporation
-
-
-0. Introduction
-
-The generic thermal sysfs provides a set of interfaces for thermal zone
-devices (sensors) and thermal cooling devices (fan, processor...) to register
-with the thermal management solution and to be a part of it.
-
-This how-to focuses on enabling new thermal zone and cooling devices to
-participate in thermal management.
-This solution is platform independent and any type of thermal zone devices
-and cooling devices should be able to make use of the infrastructure.
-
-The main task of the thermal sysfs driver is to expose thermal zone attributes
-as well as cooling device attributes to the user space.
-An intelligent thermal management application can make decisions based on
-inputs from thermal zone attributes (the current temperature and trip point
-temperature) and throttle appropriate devices.
-
-[0-*]	denotes any positive number starting from 0
-[1-*]	denotes any positive number starting from 1
-
-1. thermal sysfs driver interface functions
-
-1.1 thermal zone device interface
-1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
-		int trips, void *devdata, struct thermal_zone_device_ops *ops)
-
-    This interface function adds a new thermal zone device (sensor) to
-    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
-    thermal cooling devices registered at the same time.
-
-    name: the thermal zone name.
-    trips: the total number of trip points this thermal zone supports.
-    devdata: device private data
-    ops: thermal zone device call-backs.
-	.bind: bind the thermal zone device with a thermal cooling device.
-	.unbind: unbind the thermal zone device with a thermal cooling device.
-	.get_temp: get the current temperature of the thermal zone.
-	.get_mode: get the current mode (user/kernel) of the thermal zone.
-	    - "kernel" means thermal management is done in kernel.
-	    - "user" will prevent kernel thermal driver actions upon trip points
-	      so that user applications can take charge of thermal management.
-	.set_mode: set the mode (user/kernel) of the thermal zone.
-	.get_trip_type: get the type of certain trip point.
-	.get_trip_temp: get the temperature above which the certain trip point
-			will be fired.
-
-1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
-
-    This interface function removes the thermal zone device.
-    It deletes the corresponding entry form /sys/class/thermal folder and
-    unbind all the thermal cooling devices it uses.
-
-1.2 thermal cooling device interface
-1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
-		void *devdata, struct thermal_cooling_device_ops *)
-
-    This interface function adds a new thermal cooling device (fan/processor/...)
-    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
-    to all the thermal zone devices register at the same time.
-    name: the cooling device name.
-    devdata: device private data.
-    ops: thermal cooling devices call-backs.
-	.get_max_state: get the Maximum throttle state of the cooling device.
-	.get_cur_state: get the Current throttle state of the cooling device.
-	.set_cur_state: set the Current throttle state of the cooling device.
-
-1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
-
-    This interface function remove the thermal cooling device.
-    It deletes the corresponding entry form /sys/class/thermal folder and
-    unbind itself from all the thermal zone devices using it.
-
-1.3 interface for binding a thermal zone device with a thermal cooling device
-1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
-		int trip, struct thermal_cooling_device *cdev);
-
-    This interface function bind a thermal cooling device to the certain trip
-    point of a thermal zone device.
-    This function is usually called in the thermal zone device .bind callback.
-    tz: the thermal zone device
-    cdev: thermal cooling device
-    trip: indicates which trip point the cooling devices is associated with
-	  in this thermal zone.
-
-1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
-		int trip, struct thermal_cooling_device *cdev);
-
-    This interface function unbind a thermal cooling device from the certain
-    trip point of a thermal zone device. This function is usually called in
-    the thermal zone device .unbind callback.
-    tz: the thermal zone device
-    cdev: thermal cooling device
-    trip: indicates which trip point the cooling devices is associated with
-	  in this thermal zone.
-
-2. sysfs attributes structure
-
-RO	read only value
-RW	read/write value
-
-Thermal sysfs attributes will be represented under /sys/class/thermal.
-Hwmon sysfs I/F extension is also available under /sys/class/hwmon
-if hwmon is compiled in or built as a module.
-
-Thermal zone device sys I/F, created once it's registered:
-/sys/class/thermal/thermal_zone[0-*]:
-    |---type:			Type of the thermal zone
-    |---temp:			Current temperature
-    |---mode:			Working mode of the thermal zone
-    |---trip_point_[0-*]_temp:	Trip point temperature
-    |---trip_point_[0-*]_type:	Trip point type
-
-Thermal cooling device sys I/F, created once it's registered:
-/sys/class/thermal/cooling_device[0-*]:
-    |---type:			Type of the cooling device(processor/fan/...)
-    |---max_state:		Maximum cooling state of the cooling device
-    |---cur_state:		Current cooling state of the cooling device
-
-
-Then next two dynamic attributes are created/removed in pairs. They represent
-the relationship between a thermal zone and its associated cooling device.
-They are created/removed for each successful execution of
-thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
-
-/sys/class/thermal/thermal_zone[0-*]:
-    |---cdev[0-*]:		[0-*]th cooling device in current thermal zone
-    |---cdev[0-*]_trip_point:	Trip point that cdev[0-*] is associated with
-
-Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
-the generic thermal driver also creates a hwmon sysfs I/F for each _type_
-of thermal zone device. E.g. the generic thermal driver registers one hwmon
-class device and build the associated hwmon sysfs I/F for all the registered
-ACPI thermal zones.
-
-/sys/class/hwmon/hwmon[0-*]:
-    |---name:			The type of the thermal zone devices
-    |---temp[1-*]_input:	The current temperature of thermal zone [1-*]
-    |---temp[1-*]_critical:	The critical trip point of thermal zone [1-*]
-
-Please read Documentation/hwmon/sysfs-interface for additional information.
-
-***************************
-* Thermal zone attributes *
-***************************
-
-type
-	Strings which represent the thermal zone type.
-	This is given by thermal zone driver as part of registration.
-	E.g: "acpitz" indicates it's an ACPI thermal device.
-	In order to keep it consistent with hwmon sys attribute; this should
- 	be a short, lowercase string, not containing spaces nor dashes.
-	RO, Required
-
-temp
-	Current temperature as reported by thermal zone (sensor).
-	Unit: millidegree Celsius
-	RO, Required
-
-mode
-	One of the predefined values in [kernel, user].
-	This file gives information about the algorithm that is currently
-	managing the thermal zone. It can be either default kernel based
-	algorithm or user space application.
-	kernel	= Thermal management in kernel thermal zone driver.
-	user	= Preventing kernel thermal zone driver actions upon
-		  trip points so that user application can take full
-		  charge of the thermal management.
-	RW, Optional
-
-trip_point_[0-*]_temp
-	The temperature above which trip point will be fired.
-	Unit: millidegree Celsius
-	RO, Optional
-
-trip_point_[0-*]_type
-	Strings which indicate the type of the trip point.
-	E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
-	thermal zone.
-	RO, Optional
-
-cdev[0-*]
-	Sysfs link to the thermal cooling device node where the sys I/F
-	for cooling device throttling control represents.
-	RO, Optional
-
-cdev[0-*]_trip_point
-	The trip point with which cdev[0-*] is associated in this thermal
-	zone; -1 means the cooling device is not associated with any trip
-	point.
-	RO, Optional
-
-passive
-	Attribute is only present for zones which do not have a passive
-	cooling policy (_PSV) defined in ACPI. Default is zero and can be
-	set to a temperature (in millidegrees) to enable a passive trip
-	point for the zone. Activation is done by polling (default interval:
-	10 seconds); the polling interval can be set in
-	/proc/acpi/thermal/TZN/polling_frequency.
-	Unit: millidegree Celsius
-	RW, Optional
-
-*****************************
-* Cooling device attributes *
-*****************************
-
-type
-	String which represents the type of device, e.g:
-	- for generic ACPI: should be "Fan", "Processor" or "LCD"
-	- for memory controller device on intel_menlow platform:
-	  should be "Memory controller".
-	RO, Required
-
-max_state
-	The maximum permissible cooling state of this cooling device.
-	RO, Required
-
-cur_state
-	The current cooling state of this cooling device.
-	The value can any integer numbers between 0 and max_state:
-	- cur_state == 0 means no cooling
-	- cur_state == max_state means the maximum cooling.
-	RW, Required
-
-3. A simple implementation
-
-ACPI thermal zone may support multiple trip points like critical, hot,
-passive, active. If an ACPI thermal zone supports critical, passive,
-active[0] and active[1] at the same time, it may register itself as a
-thermal_zone_device (thermal_zone1) with 4 trip points in all.
-It has one processor and one fan, which are both registered as
-thermal_cooling_device.
-
-If the processor is listed in _PSL method, the fan is listed in _AL0
-method, and the zone hase a _PSV method, the sys I/F structure will be
-built like this:
-
-/sys/class/thermal:
-
-|thermal_zone1:
-    |---type:			acpitz
-    |---temp:			37000
-    |---mode:			kernel
-    |---trip_point_0_temp:	100000
-    |---trip_point_0_type:	critical
-    |---trip_point_1_temp:	80000
-    |---trip_point_1_type:	passive
-    |---trip_point_2_temp:	70000
-    |---trip_point_2_type:	active0
-    |---trip_point_3_temp:	60000
-    |---trip_point_3_type:	active1
-    |---cdev0:			--->/sys/class/thermal/cooling_device0
-    |---cdev0_trip_point:	1	/* cdev0 can be used for passive */
-    |---cdev1:			--->/sys/class/thermal/cooling_device3
-    |---cdev1_trip_point:	2	/* cdev1 can be used for active[0]*/
-
-|cooling_device0:
-    |---type:			Processor
-    |---max_state:		8
-    |---cur_state:		0
-
-|cooling_device3:
-    |---type:			Fan
-    |---max_state:		2
-    |---cur_state:		0
-
-/sys/class/hwmon:
-
-|hwmon0:
-    |---name:			acpitz
-    |---temp1_input:		37000
-    |---temp1_crit:		100000

Re: [PATCH 3/3] acpi: thermal/sysfs-api.txt: move to acpi directory

[Zhang Rui]

On Fri, 2009-08-21 at 17:02 +0800, Frans Pop wrote:
> It is a more logical place to look and reduces the clutter in
> the Documentation directory as the thermal directory is now empty
> and can be removed.
> 
> Signed-off-by: Frans Pop <elendil@planet.nl>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Sujith Thomas <sujith.thomas@intel.com>

NAK.

this document describes the sysfs I/F of the GENERIC thermal driver.
ACPI thermal driver is just the first user of this thermal sysfs driver.
More drivers than ACPI will use this framework in the future.

thanks,
rui

> 
> diff --git a/Documentation/acpi/thermal-sysfs-api.txt b/Documentation/acpi/thermal-sysfs-api.txt
> new file mode 100644
> index 0000000..52b63c4
> --- /dev/null
> +++ b/Documentation/acpi/thermal-sysfs-api.txt
> @@ -0,0 +1,281 @@
> +Generic Thermal Sysfs driver How To
> +===================================
> +
> +Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
> +
> +Updated: 21 August 2009
> +
> +Copyright (c)  2008 Intel Corporation
> +
> +
> +0. Introduction
> +
> +The generic thermal sysfs provides a set of interfaces for thermal zone
> +devices (sensors) and thermal cooling devices (fan, processor...) to register
> +with the thermal management solution and to be a part of it.
> +
> +This how-to focuses on enabling new thermal zone and cooling devices to
> +participate in thermal management.
> +This solution is platform independent and any type of thermal zone devices
> +and cooling devices should be able to make use of the infrastructure.
> +
> +The main task of the thermal sysfs driver is to expose thermal zone attributes
> +as well as cooling device attributes to the user space.
> +An intelligent thermal management application can make decisions based on
> +inputs from thermal zone attributes (the current temperature and trip point
> +temperature) and throttle appropriate devices.
> +
> +[0-*]  denotes any positive number starting from 0
> +[1-*]  denotes any positive number starting from 1
> +
> +1. thermal sysfs driver interface functions
> +
> +1.1 thermal zone device interface
> +1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
> +               int trips, void *devdata, struct thermal_zone_device_ops *ops)
> +
> +    This interface function adds a new thermal zone device (sensor) to
> +    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
> +    thermal cooling devices registered at the same time.
> +
> +    name: the thermal zone name.
> +    trips: the total number of trip points this thermal zone supports.
> +    devdata: device private data
> +    ops: thermal zone device call-backs.
> +       .bind: bind the thermal zone device with a thermal cooling device.
> +       .unbind: unbind the thermal zone device with a thermal cooling device.
> +       .get_temp: get the current temperature of the thermal zone.
> +       .get_mode: get the current mode (user/kernel) of the thermal zone.
> +           - "kernel" means thermal management is done in kernel.
> +           - "user" will prevent kernel thermal driver actions upon trip points
> +             so that user applications can take charge of thermal management.
> +       .set_mode: set the mode (user/kernel) of the thermal zone.
> +       .get_trip_type: get the type of certain trip point.
> +       .get_trip_temp: get the temperature above which the certain trip point
> +                       will be fired.
> +
> +1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
> +
> +    This interface function removes the thermal zone device.
> +    It deletes the corresponding entry form /sys/class/thermal folder and
> +    unbind all the thermal cooling devices it uses.
> +
> +1.2 thermal cooling device interface
> +1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
> +               void *devdata, struct thermal_cooling_device_ops *)
> +
> +    This interface function adds a new thermal cooling device (fan/processor/...)
> +    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
> +    to all the thermal zone devices register at the same time.
> +    name: the cooling device name.
> +    devdata: device private data.
> +    ops: thermal cooling devices call-backs.
> +       .get_max_state: get the Maximum throttle state of the cooling device.
> +       .get_cur_state: get the Current throttle state of the cooling device.
> +       .set_cur_state: set the Current throttle state of the cooling device.
> +
> +1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> +
> +    This interface function remove the thermal cooling device.
> +    It deletes the corresponding entry form /sys/class/thermal folder and
> +    unbind itself from all the thermal zone devices using it.
> +
> +1.3 interface for binding a thermal zone device with a thermal cooling device
> +1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
> +               int trip, struct thermal_cooling_device *cdev);
> +
> +    This interface function bind a thermal cooling device to the certain trip
> +    point of a thermal zone device.
> +    This function is usually called in the thermal zone device .bind callback.
> +    tz: the thermal zone device
> +    cdev: thermal cooling device
> +    trip: indicates which trip point the cooling devices is associated with
> +         in this thermal zone.
> +
> +1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
> +               int trip, struct thermal_cooling_device *cdev);
> +
> +    This interface function unbind a thermal cooling device from the certain
> +    trip point of a thermal zone device. This function is usually called in
> +    the thermal zone device .unbind callback.
> +    tz: the thermal zone device
> +    cdev: thermal cooling device
> +    trip: indicates which trip point the cooling devices is associated with
> +         in this thermal zone.
> +
> +2. sysfs attributes structure
> +
> +RO     read only value
> +RW     read/write value
> +
> +Thermal sysfs attributes will be represented under /sys/class/thermal.
> +Hwmon sysfs I/F extension is also available under /sys/class/hwmon
> +if hwmon is compiled in or built as a module.
> +
> +Thermal zone device sys I/F, created once it's registered:
> +/sys/class/thermal/thermal_zone[0-*]:
> +    |---type:                  Type of the thermal zone
> +    |---temp:                  Current temperature
> +    |---mode:                  Working mode of the thermal zone
> +    |---trip_point_[0-*]_temp: Trip point temperature
> +    |---trip_point_[0-*]_type: Trip point type
> +
> +Thermal cooling device sys I/F, created once it's registered:
> +/sys/class/thermal/cooling_device[0-*]:
> +    |---type:                  Type of the cooling device(processor/fan/...)
> +    |---max_state:             Maximum cooling state of the cooling device
> +    |---cur_state:             Current cooling state of the cooling device
> +
> +
> +Then next two dynamic attributes are created/removed in pairs. They represent
> +the relationship between a thermal zone and its associated cooling device.
> +They are created/removed for each successful execution of
> +thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
> +
> +/sys/class/thermal/thermal_zone[0-*]:
> +    |---cdev[0-*]:             [0-*]th cooling device in current thermal zone
> +    |---cdev[0-*]_trip_point:  Trip point that cdev[0-*] is associated with
> +
> +Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
> +the generic thermal driver also creates a hwmon sysfs I/F for each _type_
> +of thermal zone device. E.g. the generic thermal driver registers one hwmon
> +class device and build the associated hwmon sysfs I/F for all the registered
> +ACPI thermal zones.
> +
> +/sys/class/hwmon/hwmon[0-*]:
> +    |---name:                  The type of the thermal zone devices
> +    |---temp[1-*]_input:       The current temperature of thermal zone [1-*]
> +    |---temp[1-*]_critical:    The critical trip point of thermal zone [1-*]
> +
> +Please read Documentation/hwmon/sysfs-interface for additional information.
> +
> +***************************
> +* Thermal zone attributes *
> +***************************
> +
> +type
> +       Strings which represent the thermal zone type.
> +       This is given by thermal zone driver as part of registration.
> +       E.g: "acpitz" indicates it's an ACPI thermal device.
> +       In order to keep it consistent with hwmon sys attribute; this should
> +       be a short, lowercase string, not containing spaces nor dashes.
> +       RO, Required
> +
> +temp
> +       Current temperature as reported by thermal zone (sensor).
> +       Unit: millidegree Celsius
> +       RO, Required
> +
> +mode
> +       One of the predefined values in [kernel, user].
> +       This file gives information about the algorithm that is currently
> +       managing the thermal zone. It can be either default kernel based
> +       algorithm or user space application.
> +       kernel  = Thermal management in kernel thermal zone driver.
> +       user    = Preventing kernel thermal zone driver actions upon
> +                 trip points so that user application can take full
> +                 charge of the thermal management.
> +       RW, Optional
> +
> +trip_point_[0-*]_temp
> +       The temperature above which trip point will be fired.
> +       Unit: millidegree Celsius
> +       RO, Optional
> +
> +trip_point_[0-*]_type
> +       Strings which indicate the type of the trip point.
> +       E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
> +       thermal zone.
> +       RO, Optional
> +
> +cdev[0-*]
> +       Sysfs link to the thermal cooling device node where the sys I/F
> +       for cooling device throttling control represents.
> +       RO, Optional
> +
> +cdev[0-*]_trip_point
> +       The trip point with which cdev[0-*] is associated in this thermal
> +       zone; -1 means the cooling device is not associated with any trip
> +       point.
> +       RO, Optional
> +
> +passive
> +       Attribute is only present for zones which do not have a passive
> +       cooling policy (_PSV) defined in ACPI. Default is zero and can be
> +       set to a temperature (in millidegrees) to enable a passive trip
> +       point for the zone. Activation is done by polling (default interval:
> +       10 seconds); the polling interval can be set in
> +       /proc/acpi/thermal/TZN/polling_frequency.
> +       Unit: millidegree Celsius
> +       RW, Optional
> +
> +*****************************
> +* Cooling device attributes *
> +*****************************
> +
> +type
> +       String which represents the type of device, e.g:
> +       - for generic ACPI: should be "Fan", "Processor" or "LCD"
> +       - for memory controller device on intel_menlow platform:
> +         should be "Memory controller".
> +       RO, Required
> +
> +max_state
> +       The maximum permissible cooling state of this cooling device.
> +       RO, Required
> +
> +cur_state
> +       The current cooling state of this cooling device.
> +       The value can any integer numbers between 0 and max_state:
> +       - cur_state == 0 means no cooling
> +       - cur_state == max_state means the maximum cooling.
> +       RW, Required
> +
> +3. A simple implementation
> +
> +ACPI thermal zone may support multiple trip points like critical, hot,
> +passive, active. If an ACPI thermal zone supports critical, passive,
> +active[0] and active[1] at the same time, it may register itself as a
> +thermal_zone_device (thermal_zone1) with 4 trip points in all.
> +It has one processor and one fan, which are both registered as
> +thermal_cooling_device.
> +
> +If the processor is listed in _PSL method, the fan is listed in _AL0
> +method, and the zone hase a _PSV method, the sys I/F structure will be
> +built like this:
> +
> +/sys/class/thermal:
> +
> +|thermal_zone1:
> +    |---type:                  acpitz
> +    |---temp:                  37000
> +    |---mode:                  kernel
> +    |---trip_point_0_temp:     100000
> +    |---trip_point_0_type:     critical
> +    |---trip_point_1_temp:     80000
> +    |---trip_point_1_type:     passive
> +    |---trip_point_2_temp:     70000
> +    |---trip_point_2_type:     active0
> +    |---trip_point_3_temp:     60000
> +    |---trip_point_3_type:     active1
> +    |---cdev0:                 --->/sys/class/thermal/cooling_device0
> +    |---cdev0_trip_point:      1       /* cdev0 can be used for passive */
> +    |---cdev1:                 --->/sys/class/thermal/cooling_device3
> +    |---cdev1_trip_point:      2       /* cdev1 can be used for active[0]*/
> +
> +|cooling_device0:
> +    |---type:                  Processor
> +    |---max_state:             8
> +    |---cur_state:             0
> +
> +|cooling_device3:
> +    |---type:                  Fan
> +    |---max_state:             2
> +    |---cur_state:             0
> +
> +/sys/class/hwmon:
> +
> +|hwmon0:
> +    |---name:                  acpitz
> +    |---temp1_input:           37000
> +    |---temp1_crit:            100000
> diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
> deleted file mode 100644
> index 52b63c4..0000000
> --- a/Documentation/thermal/sysfs-api.txt
> +++ /dev/null
> @@ -1,281 +0,0 @@
> -Generic Thermal Sysfs driver How To
> -===================================
> -
> -Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
> -
> -Updated: 21 August 2009
> -
> -Copyright (c)  2008 Intel Corporation
> -
> -
> -0. Introduction
> -
> -The generic thermal sysfs provides a set of interfaces for thermal zone
> -devices (sensors) and thermal cooling devices (fan, processor...) to register
> -with the thermal management solution and to be a part of it.
> -
> -This how-to focuses on enabling new thermal zone and cooling devices to
> -participate in thermal management.
> -This solution is platform independent and any type of thermal zone devices
> -and cooling devices should be able to make use of the infrastructure.
> -
> -The main task of the thermal sysfs driver is to expose thermal zone attributes
> -as well as cooling device attributes to the user space.
> -An intelligent thermal management application can make decisions based on
> -inputs from thermal zone attributes (the current temperature and trip point
> -temperature) and throttle appropriate devices.
> -
> -[0-*]  denotes any positive number starting from 0
> -[1-*]  denotes any positive number starting from 1
> -
> -1. thermal sysfs driver interface functions
> -
> -1.1 thermal zone device interface
> -1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
> -               int trips, void *devdata, struct thermal_zone_device_ops *ops)
> -
> -    This interface function adds a new thermal zone device (sensor) to
> -    /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
> -    thermal cooling devices registered at the same time.
> -
> -    name: the thermal zone name.
> -    trips: the total number of trip points this thermal zone supports.
> -    devdata: device private data
> -    ops: thermal zone device call-backs.
> -       .bind: bind the thermal zone device with a thermal cooling device.
> -       .unbind: unbind the thermal zone device with a thermal cooling device.
> -       .get_temp: get the current temperature of the thermal zone.
> -       .get_mode: get the current mode (user/kernel) of the thermal zone.
> -           - "kernel" means thermal management is done in kernel.
> -           - "user" will prevent kernel thermal driver actions upon trip points
> -             so that user applications can take charge of thermal management.
> -       .set_mode: set the mode (user/kernel) of the thermal zone.
> -       .get_trip_type: get the type of certain trip point.
> -       .get_trip_temp: get the temperature above which the certain trip point
> -                       will be fired.
> -
> -1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
> -
> -    This interface function removes the thermal zone device.
> -    It deletes the corresponding entry form /sys/class/thermal folder and
> -    unbind all the thermal cooling devices it uses.
> -
> -1.2 thermal cooling device interface
> -1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
> -               void *devdata, struct thermal_cooling_device_ops *)
> -
> -    This interface function adds a new thermal cooling device (fan/processor/...)
> -    to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
> -    to all the thermal zone devices register at the same time.
> -    name: the cooling device name.
> -    devdata: device private data.
> -    ops: thermal cooling devices call-backs.
> -       .get_max_state: get the Maximum throttle state of the cooling device.
> -       .get_cur_state: get the Current throttle state of the cooling device.
> -       .set_cur_state: set the Current throttle state of the cooling device.
> -
> -1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> -
> -    This interface function remove the thermal cooling device.
> -    It deletes the corresponding entry form /sys/class/thermal folder and
> -    unbind itself from all the thermal zone devices using it.
> -
> -1.3 interface for binding a thermal zone device with a thermal cooling device
> -1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
> -               int trip, struct thermal_cooling_device *cdev);
> -
> -    This interface function bind a thermal cooling device to the certain trip
> -    point of a thermal zone device.
> -    This function is usually called in the thermal zone device .bind callback.
> -    tz: the thermal zone device
> -    cdev: thermal cooling device
> -    trip: indicates which trip point the cooling devices is associated with
> -         in this thermal zone.
> -
> -1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
> -               int trip, struct thermal_cooling_device *cdev);
> -
> -    This interface function unbind a thermal cooling device from the certain
> -    trip point of a thermal zone device. This function is usually called in
> -    the thermal zone device .unbind callback.
> -    tz: the thermal zone device
> -    cdev: thermal cooling device
> -    trip: indicates which trip point the cooling devices is associated with
> -         in this thermal zone.
> -
> -2. sysfs attributes structure
> -
> -RO     read only value
> -RW     read/write value
> -
> -Thermal sysfs attributes will be represented under /sys/class/thermal.
> -Hwmon sysfs I/F extension is also available under /sys/class/hwmon
> -if hwmon is compiled in or built as a module.
> -
> -Thermal zone device sys I/F, created once it's registered:
> -/sys/class/thermal/thermal_zone[0-*]:
> -    |---type:                  Type of the thermal zone
> -    |---temp:                  Current temperature
> -    |---mode:                  Working mode of the thermal zone
> -    |---trip_point_[0-*]_temp: Trip point temperature
> -    |---trip_point_[0-*]_type: Trip point type
> -
> -Thermal cooling device sys I/F, created once it's registered:
> -/sys/class/thermal/cooling_device[0-*]:
> -    |---type:                  Type of the cooling device(processor/fan/...)
> -    |---max_state:             Maximum cooling state of the cooling device
> -    |---cur_state:             Current cooling state of the cooling device
> -
> -
> -Then next two dynamic attributes are created/removed in pairs. They represent
> -the relationship between a thermal zone and its associated cooling device.
> -They are created/removed for each successful execution of
> -thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
> -
> -/sys/class/thermal/thermal_zone[0-*]:
> -    |---cdev[0-*]:             [0-*]th cooling device in current thermal zone
> -    |---cdev[0-*]_trip_point:  Trip point that cdev[0-*] is associated with
> -
> -Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
> -the generic thermal driver also creates a hwmon sysfs I/F for each _type_
> -of thermal zone device. E.g. the generic thermal driver registers one hwmon
> -class device and build the associated hwmon sysfs I/F for all the registered
> -ACPI thermal zones.
> -
> -/sys/class/hwmon/hwmon[0-*]:
> -    |---name:                  The type of the thermal zone devices
> -    |---temp[1-*]_input:       The current temperature of thermal zone [1-*]
> -    |---temp[1-*]_critical:    The critical trip point of thermal zone [1-*]
> -
> -Please read Documentation/hwmon/sysfs-interface for additional information.
> -
> -***************************
> -* Thermal zone attributes *
> -***************************
> -
> -type
> -       Strings which represent the thermal zone type.
> -       This is given by thermal zone driver as part of registration.
> -       E.g: "acpitz" indicates it's an ACPI thermal device.
> -       In order to keep it consistent with hwmon sys attribute; this should
> -       be a short, lowercase string, not containing spaces nor dashes.
> -       RO, Required
> -
> -temp
> -       Current temperature as reported by thermal zone (sensor).
> -       Unit: millidegree Celsius
> -       RO, Required
> -
> -mode
> -       One of the predefined values in [kernel, user].
> -       This file gives information about the algorithm that is currently
> -       managing the thermal zone. It can be either default kernel based
> -       algorithm or user space application.
> -       kernel  = Thermal management in kernel thermal zone driver.
> -       user    = Preventing kernel thermal zone driver actions upon
> -                 trip points so that user application can take full
> -                 charge of the thermal management.
> -       RW, Optional
> -
> -trip_point_[0-*]_temp
> -       The temperature above which trip point will be fired.
> -       Unit: millidegree Celsius
> -       RO, Optional
> -
> -trip_point_[0-*]_type
> -       Strings which indicate the type of the trip point.
> -       E.g. it can be one of critical, hot, passive, active[0-*] for ACPI
> -       thermal zone.
> -       RO, Optional
> -
> -cdev[0-*]
> -       Sysfs link to the thermal cooling device node where the sys I/F
> -       for cooling device throttling control represents.
> -       RO, Optional
> -
> -cdev[0-*]_trip_point
> -       The trip point with which cdev[0-*] is associated in this thermal
> -       zone; -1 means the cooling device is not associated with any trip
> -       point.
> -       RO, Optional
> -
> -passive
> -       Attribute is only present for zones which do not have a passive
> -       cooling policy (_PSV) defined in ACPI. Default is zero and can be
> -       set to a temperature (in millidegrees) to enable a passive trip
> -       point for the zone. Activation is done by polling (default interval:
> -       10 seconds); the polling interval can be set in
> -       /proc/acpi/thermal/TZN/polling_frequency.
> -       Unit: millidegree Celsius
> -       RW, Optional
> -
> -*****************************
> -* Cooling device attributes *
> -*****************************
> -
> -type
> -       String which represents the type of device, e.g:
> -       - for generic ACPI: should be "Fan", "Processor" or "LCD"
> -       - for memory controller device on intel_menlow platform:
> -         should be "Memory controller".
> -       RO, Required
> -
> -max_state
> -       The maximum permissible cooling state of this cooling device.
> -       RO, Required
> -
> -cur_state
> -       The current cooling state of this cooling device.
> -       The value can any integer numbers between 0 and max_state:
> -       - cur_state == 0 means no cooling
> -       - cur_state == max_state means the maximum cooling.
> -       RW, Required
> -
> -3. A simple implementation
> -
> -ACPI thermal zone may support multiple trip points like critical, hot,
> -passive, active. If an ACPI thermal zone supports critical, passive,
> -active[0] and active[1] at the same time, it may register itself as a
> -thermal_zone_device (thermal_zone1) with 4 trip points in all.
> -It has one processor and one fan, which are both registered as
> -thermal_cooling_device.
> -
> -If the processor is listed in _PSL method, the fan is listed in _AL0
> -method, and the zone hase a _PSV method, the sys I/F structure will be
> -built like this:
> -
> -/sys/class/thermal:
> -
> -|thermal_zone1:
> -    |---type:                  acpitz
> -    |---temp:                  37000
> -    |---mode:                  kernel
> -    |---trip_point_0_temp:     100000
> -    |---trip_point_0_type:     critical
> -    |---trip_point_1_temp:     80000
> -    |---trip_point_1_type:     passive
> -    |---trip_point_2_temp:     70000
> -    |---trip_point_2_type:     active0
> -    |---trip_point_3_temp:     60000
> -    |---trip_point_3_type:     active1
> -    |---cdev0:                 --->/sys/class/thermal/cooling_device0
> -    |---cdev0_trip_point:      1       /* cdev0 can be used for passive */
> -    |---cdev1:                 --->/sys/class/thermal/cooling_device3
> -    |---cdev1_trip_point:      2       /* cdev1 can be used for active[0]*/
> -
> -|cooling_device0:
> -    |---type:                  Processor
> -    |---max_state:             8
> -    |---cur_state:             0
> -
> -|cooling_device3:
> -    |---type:                  Fan
> -    |---max_state:             2
> -    |---cur_state:             0
> -
> -/sys/class/hwmon:
> -
> -|hwmon0:
> -    |---name:                  acpitz
> -    |---temp1_input:           37000
> -    |---temp1_crit:            100000

[PATCH 0/3] acpi: improvements for Documentation/thermal/sysfs-api.txt

[Frans Pop]

Here's three patches for your consideration:
1/3: reformat for improved readability
2/3: document passive attribute for thermal zones
3/3: move to acpi directory

The first patch mainly reduces the width of the text to make it fit better 
in normal windows, but also has a number of consistency improvements.

The second patch is the only one that really changes content. It documents 
an attribute that is currently missing in the document.
Note that I've not checked whether the description of the API still 
matches the driver code.

The third patch moves the document to an IMO more logical location and
removes the thermal directory from the top Documentation level.

Cheers,
FJP