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authorPunit Agrawal <punit.agrawal@arm.com>2015-11-17 12:06:21 +0000
committerGuodong Xu <guodong.xu@linaro.org>2017-06-06 14:23:37 +0800
commit983c1807b398f5909bd8fd25ae987dc36e655946 (patch)
treef6a80e88824f77d40103d532fb890db57a1dce94
parentddabc5287edc70da82c75a26bff88a93fcb0e275 (diff)
downloadarm64-stable-rc-983c1807b398f5909bd8fd25ae987dc36e655946.tar.gz
devicetree: bindings: Add optional dynamic-power-coefficient property
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> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--Documentation/devicetree/bindings/arm/cpus.txt17
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index 3a07a87fef20..6aca64f289b6 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 {