Message-Id: <6417aeca2f0c450545469b82f6b9bb615d1fa8ea.1632994837.git.mchehab+huawei@kernel.org>
Date:   Thu, 30 Sep 2021 11:44:48 +0200
From:   Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
To:     Linux Doc Mailing List <linux-doc@...r.kernel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        "Jonathan Corbet" <corbet@....net>,
        Amit Kucheria <amitk@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Zhang Rui <rui.zhang@...el.com>, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: [PATCH v2 1/7] ABI: sysfs-class-thermal: create a file with thermal_zone ABI

The thermal ABI is described, together with the internal
development details at:

	Documentation/driver-api/thermal/sysfs-api.rst

Move the sysfs API description to Documentation/ABI,
ensuring that scripts/get_abi.pl will properly parse it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
---

See [PATCH v2 0/7] at: https://lore.kernel.org/all/cover.1632994837.git.mchehab+huawei@kernel.org/

 Documentation/ABI/testing/sysfs-class-thermal | 259 ++++++++++++++++++
 .../driver-api/thermal/sysfs-api.rst          | 225 +--------------
 MAINTAINERS                                   |   2 +
 3 files changed, 264 insertions(+), 222 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-class-thermal

diff --git a/Documentation/ABI/testing/sysfs-class-thermal b/Documentation/ABI/testing/sysfs-class-thermal
new file mode 100644
index 000000000000..2c52bb1f864c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-thermal
@@ -0,0 +1,259 @@
+What:		/sys/class/thermal/thermal_zoneX/type
+Description:
+		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
+		shouldbe a short, lowercase string, not containing spaces nor
+		dashes.
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/temp
+Description:
+		Current temperature as reported by thermal zone (sensor).
+
+		Unit: millidegree Celsius
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/mode
+Description:
+		One of the predefined values in [enabled, disabled].
+		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.
+
+		enabled
+				enable Kernel Thermal management.
+		disabled
+				Preventing kernel thermal zone driver actions upon
+				trip points so that user application can take full
+				charge of the thermal management.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/policy
+Description:
+		One of the various thermal governors used for a particular zone.
+
+		RW, Required
+
+What:		/sys/class/thermal/thermal_zoneX/available_policies
+Description:
+		Available thermal governors which can be used for a
+		particular zone.
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_temp
+Description:
+		The temperature above which trip point will be fired.
+
+		Unit: millidegree Celsius
+
+		RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_type
+Description:
+		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
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_hyst
+Description:
+		The hysteresis value for a trip point, represented as an
+		integer.
+
+		Unit: Celsius
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY
+Description:
+	Sysfs link to the thermal cooling device node where the sys I/F
+	for cooling device throttling control represents.
+
+	RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY_trip_point
+Description:
+		The trip point in this thermal zone which `cdev[0-*]` is
+		associated with; -1 means the cooling device is not
+		associated with any trip point.
+
+		RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY_weight
+Description:
+		The influence of `cdev[0-*]` in this thermal zone. This value
+		is relative to the rest of cooling devices in the thermal
+		zone. For example, if a cooling device has a weight double
+		than that of other, it's twice as effective in cooling the
+		thermal zone.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/emul_temp
+Description:
+		Interface to set the emulated temperature method in thermal zone
+		(sensor). After setting this temperature, the thermal zone may
+		pass this temperature to platform emulation function if
+		registered or cache it locally. This is useful in debugging
+		different temperature threshold and its associated cooling
+		action. This is write only node and writing 0 on this node
+		should disable emulation.
+
+		Unit: millidegree Celsius
+
+		WO, Optional
+
+		WARNING:
+		    Be careful while enabling this option on production systems,
+		    because userland can easily disable the thermal policy by simply
+		    flooding this sysfs node with low temperature values.
+
+
+What:		/sys/class/thermal/thermal_zoneX/k_d
+Description:
+		The derivative term of the power allocator governor's PID
+		controller. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_i
+Description:
+		The integral term of the power allocator governor's PID
+		controller. This term allows the PID controller to compensate
+		for long term drift. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_po
+Description:
+		The proportional term of the power allocator governor's PID
+		controller during temperature overshoot. Temperature overshoot
+		is when the current temperature is above the "desired
+		temperature" trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_pu
+Description:
+		The proportional term of the power allocator governor's PID
+		controller during temperature undershoot. Temperature undershoot
+		is when the current temperature is below the "desired
+		temperature" trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/integral_cutoff
+Description:
+		Temperature offset from the desired temperature trip point
+		above which the integral term of the power allocator
+		governor's PID controller starts accumulating errors. For
+		example, if integral_cutoff is 0, then the integral term only
+		accumulates error when temperature is above the desired
+		temperature trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		Unit: millidegree Celsius
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/slope
+Description:
+		The slope constant used in a linear extrapolation model
+		to determine a hotspot temperature based off the sensor's
+		raw readings. It is up to the device driver to determine
+		the usage of these values.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/offset
+Description:
+		The offset constant used in a linear extrapolation model
+		to determine a hotspot temperature based off the sensor's
+		raw readings. It is up to the device driver to determine
+		the usage of these values.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/sustainable_power
+Description:
+		An estimate of the sustained power that can be dissipated by
+		the thermal zone. Used by the power allocator governor. For
+		more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		Unit: milliwatts
+
+		RW, Optional
+
+What:		/sys/class/thermal/cooling_deviceX/type
+Description:
+		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
+
+What:		/sys/class/thermal/cooling_deviceX/max_state
+Description:
+		The maximum permissible cooling state of this cooling device.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/cur_state
+Description:
+		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
+
+What:		/sys/class/thermal/cooling_deviceX/stats/reset
+Description:
+		Writing any value resets the cooling device's statistics.
+
+		WO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/time_in_state_ms:
+Description:
+		The amount of time spent by the cooling device in various
+		cooling states. The output will have "<state> <time>" pair
+		in each line, which will mean this cooling device spent <time>
+		msec of time at <state>.
+
+		Output will have one line for each of the supported states.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/total_trans
+Description:
+		A single positive value showing the total number of times
+		the state of a cooling device is changed.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/trans_table
+Description:
+		This gives fine grained information about all the cooling state
+		transitions. The cat output here is a two dimensional matrix,
+		where an entry <i,j> (row i, column j) represents the number
+		of transitions from State_i to State_j. If the transition
+		table is bigger than PAGE_SIZE, reading this will return
+		an -EFBIG error.
+
+		RO, Required
diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
index c93fa5e961a0..2e0f79a9e2ee 100644
--- a/Documentation/driver-api/thermal/sysfs-api.rst
+++ b/Documentation/driver-api/thermal/sysfs-api.rst
@@ -428,6 +428,9 @@ 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.
 
+Please read Documentation/ABI/testing/sysfs-class-thermal for thermal
+zone and cooling device attribute details.
+
 ::
 
   /sys/class/hwmon/hwmon[0-*]:
@@ -437,228 +440,6 @@ ACPI thermal zones.
 
 Please read Documentation/hwmon/sysfs-interface.rst 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 [enabled, disabled].
-	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.
-
-	enabled
-			  enable Kernel Thermal management.
-	disabled
-			  Preventing kernel thermal zone driver actions upon
-			  trip points so that user application can take full
-			  charge of the thermal management.
-
-	RW, Optional
-
-policy
-	One of the various thermal governors used for a particular zone.
-
-	RW, Required
-
-available_policies
-	Available thermal governors which can be used for a particular zone.
-
-	RO, Required
-
-`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
-
-`trip_point_[0-*]_hyst`
-	The hysteresis value for a trip point, represented as an integer
-	Unit: Celsius
-	RW, 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 in this thermal zone which `cdev[0-*]` is associated
-	with; -1 means the cooling device is not associated with any trip
-	point.
-
-	RO, Optional
-
-`cdev[0-*]_weight`
-	The influence of `cdev[0-*]` in this thermal zone. This value
-	is relative to the rest of cooling devices in the thermal
-	zone. For example, if a cooling device has a weight double
-	than that of other, it's twice as effective in cooling the
-	thermal zone.
-
-	RW, Optional
-
-emul_temp
-	Interface to set the emulated temperature method in thermal zone
-	(sensor). After setting this temperature, the thermal zone may pass
-	this temperature to platform emulation function if registered or
-	cache it locally. This is useful in debugging different temperature
-	threshold and its associated cooling action. This is write only node
-	and writing 0 on this node should disable emulation.
-	Unit: millidegree Celsius
-
-	WO, Optional
-
-	  WARNING:
-	    Be careful while enabling this option on production systems,
-	    because userland can easily disable the thermal policy by simply
-	    flooding this sysfs node with low temperature values.
-
-sustainable_power
-	An estimate of the sustained power that can be dissipated by
-	the thermal zone. Used by the power allocator governor. For
-	more information see Documentation/driver-api/thermal/power_allocator.rst
-
-	Unit: milliwatts
-
-	RW, Optional
-
-k_po
-	The proportional term of the power allocator governor's PID
-	controller during temperature overshoot. Temperature overshoot
-	is when the current temperature is above the "desired
-	temperature" trip point. For more information see
-	Documentation/driver-api/thermal/power_allocator.rst
-
-	RW, Optional
-
-k_pu
-	The proportional term of the power allocator governor's PID
-	controller during temperature undershoot. Temperature undershoot
-	is when the current temperature is below the "desired
-	temperature" trip point. For more information see
-	Documentation/driver-api/thermal/power_allocator.rst
-
-	RW, Optional
-
-k_i
-	The integral term of the power allocator governor's PID
-	controller. This term allows the PID controller to compensate
-	for long term drift. For more information see
-	Documentation/driver-api/thermal/power_allocator.rst
-
-	RW, Optional
-
-k_d
-	The derivative term of the power allocator governor's PID
-	controller. For more information see
-	Documentation/driver-api/thermal/power_allocator.rst
-
-	RW, Optional
-
-integral_cutoff
-	Temperature offset from the desired temperature trip point
-	above which the integral term of the power allocator
-	governor's PID controller starts accumulating errors. For
-	example, if integral_cutoff is 0, then the integral term only
-	accumulates error when temperature is above the desired
-	temperature trip point. For more information see
-	Documentation/driver-api/thermal/power_allocator.rst
-
-	Unit: millidegree Celsius
-
-	RW, Optional
-
-slope
-	The slope constant used in a linear extrapolation model
-	to determine a hotspot temperature based off the sensor's
-	raw readings. It is up to the device driver to determine
-	the usage of these values.
-
-	RW, Optional
-
-offset
-	The offset constant used in a linear extrapolation model
-	to determine a hotspot temperature based off the sensor's
-	raw readings. It is up to the device driver to determine
-	the usage of these values.
-
-	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
-
-stats/reset
-	Writing any value resets the cooling device's statistics.
-	WO, Required
-
-stats/time_in_state_ms:
-	The amount of time spent by the cooling device in various cooling
-	states. The output will have "<state> <time>" pair in each line, which
-	will mean this cooling device spent <time> msec of time at <state>.
-	Output will have one line for each of the supported states.
-	RO, Required
-
-
-stats/total_trans:
-	A single positive value showing the total number of times the state of a
-	cooling device is changed.
-
-	RO, Required
-
-stats/trans_table:
-	This gives fine grained information about all the cooling state
-	transitions. The cat output here is a two dimensional matrix, where an
-	entry <i,j> (row i, column j) represents the number of transitions from
-	State_i to State_j. If the transition table is bigger than PAGE_SIZE,
-	reading this will return an -EFBIG error.
-	RO, Required
-
 3. A simple implementation
 ==========================
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 9b765cbc90d1..179eadaebe76 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18653,7 +18653,9 @@ L:	linux-pm@...r.kernel.org
 S:	Supported
 Q:	https://patchwork.kernel.org/project/linux-pm/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git
+F:	Documentation/ABI/testing/sysfs-class-thermal
 F:	Documentation/devicetree/bindings/thermal/
+F:	Documentation/driver-api/thermal/
 F:	drivers/thermal/
 F:	include/linux/cpu_cooling.h
 F:	include/linux/thermal.h
-- 
2.31.1

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