Messages in this thread Patch in this message | | | Date | Mon, 16 Nov 2015 17:23:01 -0600 | From | Rob Herring <> | Subject | Re: [PATCH v4 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property |
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On Mon, Nov 16, 2015 at 07:30:23PM +0000, Punit Agrawal wrote: > The dynamic power consumption of a device is proportional to the > square of voltage (V) and the clock frequency (f). It can be expressed as > > Pdyn = dynamic-power-coefficient * V^2 * f. > > The coefficient represents the running time dynamic power consumption in > units of mw/MHz/uVolt^2 and can be used in the above formula to > calculate the dynamic power in mW. > > Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
> --- > Documentation/devicetree/bindings/arm/cpus.txt | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt > index 3a07a87..6aca64f 100644 > --- a/Documentation/devicetree/bindings/arm/cpus.txt > +++ b/Documentation/devicetree/bindings/arm/cpus.txt > @@ -242,6 +242,23 @@ nodes to be present and contain the properties described below. > Definition: Specifies the syscon node controlling the cpu core > power domains. > > + - dynamic-power-coefficient > + Usage: optional > + Value type: <prop-encoded-array> > + Definition: A u32 value that represents the running time dynamic > + power coefficient in units of mW/MHz/uVolt^2. The > + coefficient can either be calculated from power > + measurements or derived by analysis. > + > + The dynamic power consumption of the CPU is > + proportional to the square of the Voltage (V) and > + the clock frequency (f). The coefficient is used to > + calculate the dynamic power as below - > + > + Pdyn = dynamic-power-coefficient * V^2 * f > + > + where voltage is in uV, frequency is in MHz. > + > Example 1 (dual-cluster big.LITTLE system 32-bit): > > cpus { > -- > 2.6.2 >
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