linux-stable.git/include/linux/thermal.h, branch v4.3.5

thermal: Add a function to get the minimum power

2015-09-14T14:39:46+00:00

The thermal core already has a function to get the maximum power of a
cooling device: power_actor_get_max_power().  Add a function to get the
minimum power of a cooling device.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
Reviewed-by: Daniel Kurtz 
Signed-off-by: Javi Merino 
Signed-off-by: Eduardo Valentin

thermal: Fix thermal_zone_of_sensor_register to match documentation

2015-09-14T02:33:07+00:00

thermal_zone_of_sensor_register is documented as returning a pointer
to either a valid thermal_zone_device on success, or a corresponding
ERR_PTR() value.

In contrast, the function returns NULL when THERMAL_OF is configured
off. Fix this.

Signed-off-by: Punit Agrawal 
Acked-by: Guenter Roeck 
Cc: Eduardo Valentin 
Cc: Zhang Rui 
Signed-off-by: Eduardo Valentin

thermal: consistently use int for temperatures

2015-08-03T15:15:50+00:00

The thermal code uses int, long and unsigned long for temperatures
in different places.

Using an unsigned type limits the thermal framework to positive
temperatures without need. Also several drivers currently will report
temperatures near UINT_MAX for temperatures below 0°C. This will probably
immediately shut the machine down due to overtemperature if started below
0°C.

'long' is 64bit on several architectures. This is not needed since INT_MAX °mC
is above the melting point of all known materials.

Consistently use a plain 'int' for temperatures throughout the thermal code and
the drivers. This only changes the places in the drivers where the temperature
is passed around as pointer, when drivers internally use another type this is
not changed.

Signed-off-by: Sascha Hauer 
Acked-by: Geert Uytterhoeven 
Reviewed-by: Jean Delvare 
Reviewed-by: Lukasz Majewski 
Reviewed-by: Darren Hart 
Reviewed-by: Heiko Stuebner 
Reviewed-by: Peter Feuerer 
Cc: Punit Agrawal 
Cc: Zhang Rui 
Cc: Eduardo Valentin 
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Jean Delvare 
Cc: Peter Feuerer 
Cc: Heiko Stuebner 
Cc: Lukasz Majewski 
Cc: Stephen Warren 
Cc: Thierry Reding 
Cc: linux-acpi@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: Guenter Roeck 
Cc: Rafael J. Wysocki 
Cc: Maxime Ripard 
Cc: Darren Hart 
Cc: lm-sensors@lm-sensors.org
Signed-off-by: Zhang Rui

thermal: support slope and offset coefficients

2015-05-12T02:46:52+00:00

It is common to have a linear extrapolation from
the current sensor readings and the actual temperature
value. This is specially the case when the sensor
is in use to extrapolate hotspots.

This patch adds slope and offset constants for
single sensor linear extrapolation equation. Because
the same sensor can be use in different locations,
from board to board, these constants are added
as part of thermal_zone_params.

The constants are available through sysfs.

It is up to the device driver to determine
the usage of these values.

Signed-off-by: Eduardo Valentin

thermal: introduce the Power Allocator governor

2015-05-05T04:27:52+00:00

The power allocator governor is a thermal governor that controls system
and device power allocation to control temperature.  Conceptually, the
implementation divides the sustainable power of a thermal zone among
all the heat sources in that zone.

This governor relies on "power actors", entities that represent heat
sources.  They can report current and maximum power consumption and
can set a given maximum power consumption, usually via a cooling
device.

The governor uses a Proportional Integral Derivative (PID) controller
driven by the temperature of the thermal zone.  The output of the
controller is a power budget that is then allocated to each power
actor that can have bearing on the temperature we are trying to
control.  It decides how much power to give each cooling device based
on the performance they are requesting.  The PID controller ensures
that the total power budget does not exceed the control temperature.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
Signed-off-by: Punit Agrawal 
Signed-off-by: Javi Merino 
Signed-off-by: Eduardo Valentin

thermal: extend the cooling device API to include power information

2015-05-05T04:27:52+00:00

Add three optional callbacks to the cooling device interface to allow
them to express power.  In addition to the callbacks, add helpers to
identify cooling devices that implement the power cooling device API.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
Signed-off-by: Javi Merino 
Signed-off-by: Eduardo Valentin

thermal: let governors have private data for each thermal zone

2015-05-05T04:27:52+00:00

A governor may need to store its current state between calls to
throttle().  That state depends on the thermal zone, so store it as
private data in struct thermal_zone_device.

The governors may have two new ops: bind_to_tz() and unbind_from_tz().
When provided, these functions let governors do some initialization
and teardown when they are bound/unbound to a tz and possibly store that
information in the governor_data field of the struct
thermal_zone_device.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
Signed-off-by: Javi Merino 
Signed-off-by: Eduardo Valentin

thermal: fair_share: generalize the weight concept

2015-05-05T04:27:51+00:00

The fair share governor has the concept of weights, which is the
influence of each cooling device in a thermal zone.  The current
implementation forces the weights of all cooling devices in a thermal
zone to add up to a 100.  This complicates setups, as you need to know
in advance how many cooling devices you are going to have.  If you bind a
new cooling device, you have to modify all the other cooling devices
weights, which is error prone.  Furthermore, you can't specify a
"default" weight for platforms since that default value depends on the
number of cooling devices in the platform.

This patch generalizes the concept of weight by allowing any number to
be a "weight".  Weights are now relative to each other.  Platforms that
don't specify weights get the same default value for all their cooling
devices, so all their cdevs are considered to be equally influential.

It's important to note that previous users of the weights don't need to
alter the code: percentages continue to work as they used to.  This
patch just removes the constraint of all the weights in a thermal zone
having to add up to a 100.  If they do, you get the same behavior as
before.  If they don't, fair share now works for that platform.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
Cc: Durgadoss R 
Acked-by: Durgadoss R 
Signed-off-by: Javi Merino 
Signed-off-by: Eduardo Valentin

thermal: of: fix cooling device weights in device tree

2015-05-05T04:27:50+00:00

Currently you can specify the weight of the cooling device in the device
tree but that information is not populated to the
thermal_bind_params where the fair share governor expects it to
be.  The of thermal zone device doesn't have a thermal_bind_params
structure and arguably it's better to pass the weight inside the
thermal_instance as it is specific to the bind of a cooling device to a
thermal zone parameter.

Core thermal code is fixed to populate the weight in the instance from
the thermal_bind_params, so platform code that was passing the weight
inside the thermal_bind_params continue to work seamlessly.

While we are at it, create a default value for the weight parameter for
those thermal zones that currently don't define it and remove the
hardcoded default in of-thermal.

Cc: Zhang Rui 
Cc: "Rafael J. Wysocki" 
Cc: Len Brown 
Cc: Peter Feuerer 
Cc: Darren Hart 
Cc: Eduardo Valentin 
Cc: Kukjin Kim 
Cc: Durgadoss R 
Signed-off-by: Kapileshwar Singh 
Signed-off-by: Eduardo Valentin

thermal: Introduce dummy functions when thermal is not defined

2015-02-24T18:40:42+00:00

When CONFIG_THERMAL is not enabled, it is better to introduce
equivalent dummy functions in the exported header than to
introduce #ifdeffery in drivers using the function.

This will prevent issues such as that reported in:
http://www.spinics.net/lists/linux-next/msg31573.html

While at it switch over to IS_ENABLED for thermal macros
to allow for thermal framework to be built as framework
and relevant APIs be usable by relevant drivers as a result.

Reported-by: Guenter Roeck 
Signed-off-by: Nishanth Menon 
Signed-off-by: Eduardo Valentin