[PATCH v2 01/10] devicetree: bindings: Add optional dynamic-power-coefficient property

Punit Agrawal
2015-08-03T15:23:58Z

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 dynamic-power-coefficient property represents an indicative
running time dynamic power coefficient in fundamental 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>
---
Documentation/devicetree/bindings/arm/cpus.txt | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index d6b794c..c32bfac 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -239,6 +239,21 @@ 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 an indicative
+ running time dynamic power coefficient in
+ fundamental units of mW/MHz/uVolt^2.
+
+ The dynamic energy consumption of the CPU
+ is proportional to the square of the
+ Voltage (V) and the clock frequency (f).
+
+ 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 {
--
2.1.4