linux/drivers/thermal/Kconfig
Amit Daniel Kachhap 0236141837 thermal: add generic cpufreq cooling implementation
This patchset introduces a new generic cooling device based on cpufreq
that can be used on non-ACPI platforms.  As a proof of concept, we have
drivers for the following platforms using this mechanism now:

 * Samsung Exynos (Exynos4 and Exynos5) in the current patchset.
 * Freescale i.MX (git://git.linaro.org/people/amitdanielk/linux.git imx6q_thermal)

There is a small change in cpufreq cooling registration APIs, so a minor
change is needed for Freescale platforms.

Brief Description:

1) The generic cooling devices code is placed inside driver/thermal/*
   as placing inside acpi folder will need un-necessary enabling of acpi
   code.  This code is architecture independent.

2) This patchset adds generic cpu cooling low level implementation
   through frequency clipping.  In future, other cpu related cooling
   devices may be added here.  An ACPI version of this already exists
   (drivers/acpi/processor_thermal.c) .But this will be useful for
   platforms like ARM using the generic thermal interface along with the
   generic cpu cooling devices.  The cooling device registration API's
   return cooling device pointers which can be easily binded with the
   thermal zone trip points.  The important APIs exposed are,

   a) struct thermal_cooling_device *cpufreq_cooling_register(
        struct cpumask *clip_cpus)
   b) void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)

3) Samsung exynos platform thermal implementation is done using the
   generic cpu cooling APIs and the new trip type.  The temperature sensor
   driver present in the hwmon folder(registered as hwmon driver) is moved
   to thermal folder and registered as a thermal driver.

A simple data/control flow diagrams is shown below,

Core Linux thermal <----->  Exynos thermal interface <----- Temperature Sensor
          |                             |
         \|/                            |
  Cpufreq cooling device <---------------

TODO:
*Will send the DT enablement patches later after the driver is merged.

This patch:

Add support for generic cpu thermal cooling low level implementations
using frequency scaling up/down based on the registration parameters.
Different cpu related cooling devices can be registered by the user and
the binding of these cooling devices to the corresponding trip points can
be easily done as the registration APIs return the cooling device pointer.
The user of these APIs are responsible for passing clipping frequency .
The drivers can also register to recieve notification about any cooling
action called.

[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: SangWook Ju <sw.ju@samsung.com>
Cc: Durgadoss <durgadoss.r@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2012-09-24 14:44:38 +08:00

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#
# Generic thermal sysfs drivers configuration
#
menuconfig THERMAL
tristate "Generic Thermal sysfs driver"
help
Generic Thermal Sysfs driver offers a generic mechanism for
thermal management. Usually it's made up of one or more thermal
zone and cooling device.
Each thermal zone contains its own temperature, trip points,
cooling devices.
All platforms with ACPI thermal support can use this driver.
If you want this support, you should say Y or M here.
config THERMAL_HWMON
bool
depends on THERMAL
depends on HWMON=y || HWMON=THERMAL
default y
config CPU_THERMAL
bool "generic cpu cooling support"
depends on THERMAL && CPU_FREQ
help
This implements the generic cpu cooling mechanism through frequency
reduction, cpu hotplug and any other ways of reducing temperature. An
ACPI version of this already exists(drivers/acpi/processor_thermal.c).
This will be useful for platforms using the generic thermal interface
and not the ACPI interface.
If you want this support, you should say Y here.
config SPEAR_THERMAL
bool "SPEAr thermal sensor driver"
depends on THERMAL
depends on PLAT_SPEAR
depends on OF
help
Enable this to plug the SPEAr thermal sensor driver into the Linux
thermal framework
config RCAR_THERMAL
tristate "Renesas R-Car thermal driver"
depends on THERMAL
depends on ARCH_SHMOBILE
help
Enable this to plug the R-Car thermal sensor driver into the Linux
thermal framework