From mboxrd@z Thu Jan 1 00:00:00 1970 From: Punit Agrawal Subject: [PATCH v5 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Date: Tue, 17 Nov 2015 12:06:21 +0000 Message-ID: <1447761983-12415-2-git-send-email-punit.agrawal@arm.com> References: <1447761983-12415-1-git-send-email-punit.agrawal@arm.com> Return-path: In-Reply-To: <1447761983-12415-1-git-send-email-punit.agrawal@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-pm@vger.kernel.org Cc: Punit Agrawal , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, edubezval@gmail.com, dawei.chien@mediatek.com, javi.merino@arm.com, viresh.kumar@linaro.org, rjw@rjwysocki.net, Mark Rutland List-Id: devicetree@vger.kernel.org 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 Acked-by: Rob Herring Reviewed-by: Viresh Kumar Cc: Mark Rutland --- 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 3a07a87..6aca64f 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: + 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 { -- 2.6.2