linux-toradex.git/Documentation/thermal/sysfs-api.txt, branch v4.2.6

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: export thermal_zone_parameters to sysfs

2015-05-05T04:27:54+00:00

It's useful for tuning to be able to edit thermal_zone_parameters from
userspace.  Export them to the thermal_zone sysfs so that they can be
easily changed.

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: export weight to sysfs

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

It's useful to have access to the weights for the cooling devices for
thermal zones and change them if needed.  Export them to sysfs.

Cc: Zhang Rui 
Cc: Eduardo Valentin 
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: thermal_core: allow binding with limits on bind_params

2013-09-03T13:10:24+00:00

When registering a thermal zone device using platform information
via bind_params, the thermal framework will always perform the
cdev binding using the lowest and highest limits (THERMAL_NO_LIMIT).

This patch changes the data structures so that it is possible
to inform what are the desired limits for each trip point
inside a bind_param. The way the binding is performed is also
changed so that it uses the new data structure.

Cc: Zhang Rui 
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin

drivers: thermal: make usage of CONFIG_THERMAL_HWMON optional

2013-09-03T13:10:11+00:00

When registering a new thermal_device, the thermal framework
will always add a hwmon sysfs interface.

This patch adds a flag to make this behavior optional. Now
when registering a new thermal device, the caller can
optionally inform if hwmon interface is desirable. This can
be done by means of passing a thermal_zone_params.no_hwmon == true.

In order to keep same behavior as of today, all current
calls will by default create the hwmon interface.

Cc: David Woodhouse 
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Zhang Rui 
Suggested-by: Wei Ni 
Signed-off-by: Eduardo Valentin

Thermal: update documentation for thermal_zone_device_register

2013-04-27T01:16:04+00:00

Update kernel Documentation for thermal_zone_device_register.

Signed-off-by: Zhang Rui

thermal: rename notify_thermal_framework to thermal_notify_framework

2013-04-24T16:56:16+00:00

To follow the prefix names used by the thermal functions,
this patch renames notify_thermal_framework to thermal_notify_framework.

Signed-off-by: Eduardo Valentin 
Signed-off-by: Zhang Rui

Thermal: build thermal governors into thermal_sys module

2013-04-14T15:28:43+00:00

The thermal governors are part of the thermal framework,
rather than a seperate feature/module.
Because the generic thermal layer can not work without
thermal governors, and it must load the thermal governors
during its initialization.

Build them into one module in this patch.

This also fix a problem that the generic thermal layer does not
work when CONFIG_THERMAL=m and CONFIG_THERMAL_GOV_XXX=y.

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