On Mon, Nov 09, 2015 at 05:29:21PM +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.
I have no issue with the binding, but I wonder if a single value is really sufficient to model this. Don't you also need a static component? Rob > > Signed-off-by: Punit Agrawal <[email protected]> > Cc: Rob Herring <[email protected]> > Cc: Mark Rutland <[email protected]> > --- > 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 91e6e5c..c33362d 100644 > --- a/Documentation/devicetree/bindings/arm/cpus.txt > +++ b/Documentation/devicetree/bindings/arm/cpus.txt > @@ -240,6 +240,23 @@ 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 { > -- > 2.5.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
