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From: "Chen-Yu Tsai (Moxa)" <wens@csie.org>
To: nobuhiro1.iwamatsu@toshiba.co.jp, pavel@denx.de
Cc: cip-dev@lists.cip-project.org, JohnsonCH.Chen@moxa.com
Subject: [cip-dev] [PATCH 4.4.y-cip v3 11/14] devicetree: bindings: Add optional dynamic-power-coefficient property
Date: Tue,  9 Jun 2020 12:09:23 +0800	[thread overview]
Message-ID: <20200609040926.8910-12-wens@csie.org> (raw)
In-Reply-To: <20200609040926.8910-1-wens@csie.org>

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From: Punit Agrawal <punit.agrawal@arm.com>

commit 3be3f8f36e7349006f19c8c8f0d686e98462a993 upstream.

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>
Signed-off-by: Chen-Yu Tsai (Moxa) <wens@csie.org>
---
 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 9ef9a2089a5e7..6b1d8ebb94b7b 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -243,6 +243,23 @@ 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 {
-- 
2.27.0.rc0


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  parent reply	other threads:[~2020-06-09  4:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-09  4:09 [cip-dev] [PATCH 4.4.y-cip v3 00/14] PM / OPP v2 & cpufreq backports part 1 Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 01/14] PM / OPP: Add debugfs support Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 02/14] PM / OPP: Add "opp-supported-hw" binding Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 03/14] PM / OPP: Add {opp-microvolt|opp-microamp}-<name> binding Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 04/14] PM / OPP: Remove 'operating-points-names' binding Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 05/14] PM / OPP: Rename OPP nodes as opp@<opp-hz> Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 06/14] PM / OPP: Add missing doc comments Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 07/14] PM / OPP: Parse 'opp-supported-hw' binding Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 08/14] PM / OPP: Parse 'opp-<prop>-<name>' bindings Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 09/14] PM / OPP: Set cpu_dev->id in cpumask first Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 10/14] PM / OPP: Use snprintf() instead of sprintf() Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` Chen-Yu Tsai (Moxa) [this message]
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 12/14] cpufreq-dt: Supply power coefficient when registering cooling devices Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 13/14] cpufreq-dt: fix handling regulator_get_voltage() result Chen-Yu Tsai (Moxa)
2020-06-09  4:09 ` [cip-dev] [PATCH 4.4.y-cip v3 14/14] cpufreq: cpufreq-dt: avoid uninitialized variable warnings: Chen-Yu Tsai (Moxa)
2020-06-09 11:01 ` [cip-dev] [PATCH 4.4.y-cip v3 00/14] PM / OPP v2 & cpufreq backports part 1 Pavel Machek

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