From patchwork Mon Nov 16 19:30:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Punit Agrawal X-Patchwork-Id: 56683 Delivered-To: patch@linaro.org Received: by 10.112.155.196 with SMTP id vy4csp1509385lbb; Mon, 16 Nov 2015 11:31:04 -0800 (PST) X-Received: by 10.66.157.9 with SMTP id wi9mr16578774pab.98.1447702264119; Mon, 16 Nov 2015 11:31:04 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id nj10si52409941pbc.46.2015.11.16.11.31.03; Mon, 16 Nov 2015 11:31:04 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751882AbbKPTbC (ORCPT + 6 others); Mon, 16 Nov 2015 14:31:02 -0500 Received: from fw-tnat.cambridge.arm.com ([217.140.96.140]:34879 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751847AbbKPTbB (ORCPT ); Mon, 16 Nov 2015 14:31:01 -0500 Received: from e105922-lin.cambridge.arm.com (e105922-lin.cambridge.arm.com [10.1.207.164]) by cam-smtp0.cambridge.arm.com (8.13.8/8.13.8) with SMTP id tAGJUnqF020092; Mon, 16 Nov 2015 19:30:49 GMT Received: by e105922-lin.cambridge.arm.com (sSMTP sendmail emulation); Mon, 16 Nov 2015 19:30:49 +0000 From: Punit Agrawal To: devicetree@vger.kernel.org Cc: Punit Agrawal , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, edubezval@gmail.com, dawei.chien@mediatek.com, javi.merino@arm.com, Rob Herring , Mark Rutland Subject: [PATCH v4 1/3] devicetree: bindings: Add optional dynamic-power-coefficient property Date: Mon, 16 Nov 2015 19:30:23 +0000 Message-Id: <1447702225-13323-2-git-send-email-punit.agrawal@arm.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1447702225-13323-1-git-send-email-punit.agrawal@arm.com> References: <1447702225-13323-1-git-send-email-punit.agrawal@arm.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: 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 Cc: Rob Herring Cc: Mark Rutland --- Documentation/devicetree/bindings/arm/cpus.txt | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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 {