Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752255AbbKIRaN (ORCPT ); Mon, 9 Nov 2015 12:30:13 -0500 Received: from fw-tnat.cambridge.arm.com ([217.140.96.140]:19923 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751353AbbKIRaH (ORCPT ); Mon, 9 Nov 2015 12:30:07 -0500 From: Punit Agrawal To: devicetree@vger.kernel.org Cc: viresh.kumar@linaro.org, Punit Agrawal , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, edubezval@gmail.com, dawei.chien@mediatek.com, Rob Herring , Mark Rutland Subject: [PATCH v3 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Date: Mon, 9 Nov 2015 17:29:21 +0000 Message-Id: <1447090163-13700-2-git-send-email-punit.agrawal@arm.com> X-Mailer: git-send-email 2.5.3 In-Reply-To: <1447090163-13700-1-git-send-email-punit.agrawal@arm.com> References: <1447090163-13700-1-git-send-email-punit.agrawal@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1980 Lines: 52 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 Cc: Rob Herring 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 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: + 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/