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

Message ID 1438615378-14241-2-git-send-email-punit.agrawal@arm.com (mailing list archive)
State Not Applicable, archived
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Commit Message

Punit Agrawal Aug. 3, 2015, 3:22 p.m. UTC 
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(+)
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Patch

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 {