thermal: sysfs-api.txt - reformat for improved readability

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>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/thermal/sysfs-api.txt

 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