linux-stable/include
Quentin Perret a4f342b960 PM / OPP: Introduce a power estimation helper
The Energy Model (EM) framework provides an API to let drivers register
the active power of CPUs. The drivers are expected to provide a callback
method which estimates the power consumed by a CPU at each available
performance levels. How exactly this should be implemented, however,
depends on the platform.

On some systems, PM_OPP knows the voltage and frequency at which CPUs
can run. When coupled with the CPU 'capacitance' (as provided by the
'dynamic-power-coefficient' devicetree binding), it is possible to
estimate the dynamic power consumption of a CPU as P = C * V^2 * f, with
C its capacitance and V and f respectively the voltage and frequency of
the OPP. The Intelligent Power Allocator (IPA) thermal governor already
implements that estimation method, in the thermal framework.

However, this power estimation method can be applied to any platform
where all the parameters are known (C, V and f), and not only those
suffering thermal issues. As such, the code implementing this feature
can be re-used to also populate the EM framework now used by EAS.

As a first step, introduce in PM_OPP a helper function which CPUFreq
drivers can use to register into the EM framework. This duplicates the
power estimation done in IPA until it can be migrated to using the EM
framework. This will be done later, once the EM framework has support
for at least all platforms currently supported by IPA.

Signed-off-by: Quentin Perret <quentin.perret@arm.com>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-07 09:55:11 +05:30
..
acpi Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 17:03:51 -08:00
asm-generic Merge branch 'akpm' (patches from Andrew) 2019-01-05 09:16:18 -08:00
clocksource
crypto crypto: skcipher - remove remnants of internal IV generators 2018-12-23 11:52:45 +08:00
drm
dt-bindings Merge branch 'next/drivers' into next/late 2019-01-04 14:31:38 -08:00
keys
kvm
linux PM / OPP: Introduce a power estimation helper 2019-02-07 09:55:11 +05:30
math-emu
media media fixes for v4.20-rc8 2018-12-25 13:11:30 -08:00
memory
misc
net Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
pcmcia
ras
rdma
scsi 4.21 merge window pull request 2018-12-28 14:57:10 -08:00
soc ARM: SoC driver updates 2018-12-31 17:32:35 -08:00
sound
target
trace NFS client updates for Linux 4.21 2019-01-02 16:35:23 -08:00
uapi Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
video
xen