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: 7630311 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4EB159F1C2 for ; Mon, 16 Nov 2015 19:31:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6C94C205B6 for ; Mon, 16 Nov 2015 19:31:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85B4C20495 for ; Mon, 16 Nov 2015 19:31:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751881AbbKPTbC (ORCPT ); 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: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Acked-by: Rob Herring Reviewed-by: Viresh Kumar --- 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 {