summaryrefslogtreecommitdiff
path: root/include/linux/cpu_cooling.h
AgeCommit message (Collapse)AuthorFilesLines
2012-11-22thermal: cpu cooling: allow module buildsEduardo Valentin1-1/+1
As thermal drivers can be built as modules and also the thermal framework itself, building cpu cooling only as built-in can cause linking errors. For instance: * Generic Thermal sysfs driver * Generic Thermal sysfs driver (THERMAL) [M/n/y/?] m generic cpu cooling support (CPU_THERMAL) [N/y/?] (NEW) y with the following drive: CONFIG_OMAP_BANDGAP=m generates: ERROR: "cpufreq_cooling_unregister" [drivers/staging/omap-thermal/omap-thermal.ko] undefined! ERROR: "cpufreq_cooling_register" [drivers/staging/omap-thermal/omap-thermal.ko] undefined! This patch changes cpu cooling driver to allow it to be built as module. Reported-by: Enric Balletbo i Serra <eballetbo@gmail.com> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> Reviewed-by: Durgadoss R <durgadoss.r@intel.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2012-11-22thermal: cpu cooling: use const parameter while registeringEduardo Valentin1-2/+2
There are predefined cpu_masks that are const data structures. This patch changes the cpu cooling register function so that those const cpu_masks can be used, without compilation warnings. include/linux/cpumask.h * The following particular system cpumasks and operations manage * possible, present, active and online cpus. * * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable * cpu_present_mask - has bit 'cpu' set iff cpu is populated * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler * cpu_active_mask - has bit 'cpu' set iff cpu available to migration * Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2012-09-24thermal: add generic cpufreq cooling implementationAmit Daniel Kachhap1-0/+58
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>