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Groups > linux.kernel > #1265891
| From | Punit Agrawal <punit.agrawal@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v3 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property |
| Date | 2015-11-09 18:40 +0100 |
| Message-ID | <qsYA9-123-11@gated-at.bofh.it> (permalink) |
| References | <qsYqt-YN-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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>
---
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
--
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[PATCH v3 0/3] Dynamic power model from device tree Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 18:30 +0100
[PATCH v3 2/3] cpufreq-dt: Supply power coefficient when registering cooling devices Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 18:40 +0100
Re: [PATCH v3 2/3] cpufreq-dt: Supply power coefficient when registering cooling devices Javi Merino <javi.merino@arm.com> - 2015-11-10 13:30 +0100
[PATCH v3 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 18:40 +0100
Re: [PATCH v3 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Rob Herring <robh@kernel.org> - 2015-11-09 18:50 +0100
Re: [PATCH v3 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 19:50 +0100
[PATCH v3 3/3] cpufreq: arm_big_little: Add support to register a cpufreq cooling device Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 18:40 +0100
Re: [PATCH v3 3/3] cpufreq: arm_big_little: Add support to register a cpufreq cooling device Javi Merino <javi.merino@arm.com> - 2015-11-10 13:40 +0100
Re: [PATCH v3 3/3] cpufreq: arm_big_little: Add support to register a cpufreq cooling device Viresh Kumar <viresh.kumar@linaro.org> - 2015-11-13 06:00 +0100
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