From patchwork Wed Apr 1 11:15:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Kucheria X-Patchwork-Id: 11468979 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7374592A for ; Wed, 1 Apr 2020 11:15:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4839320857 for ; Wed, 1 Apr 2020 11:15:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="J9p4I7ha" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732426AbgDALPo (ORCPT ); Wed, 1 Apr 2020 07:15:44 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:36780 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732417AbgDALPn (ORCPT ); Wed, 1 Apr 2020 07:15:43 -0400 Received: by mail-pg1-f194.google.com with SMTP id c23so3576828pgj.3 for ; Wed, 01 Apr 2020 04:15:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iutfgAEMr3aVnETDGpH220S0Jcsh/zdk3Pb7ajXb/+Q=; b=J9p4I7ha9Kr4aCnjJUEmfgDuGIMxLJY57FMqgMrTxiyzl4NanfRaPU5YcNjC4r/WZL nk2/D0Tl7uXpOTYHkSP5WxMpGJk2c+vA+h23xv22k8NUNFpj50vfIIcD4gAJwOLIgx6a WS4B9SZwKrKwNUA+Bav04kd86EchZ0bJIdzsCORhN/TzCwYzny04tcFljyo8xk6IHdFP ev3xUa+1LKjHyvJrF75V+clg0uTz+3kBSb2zF9NHUwx1y1bB1Z15Xfh/dwudjdpdM0Uy Pu084v+RsFqNBd8Bu7PhOUvbd74pHJ026APLoYLdApY+mEFmewbWzx6YF/6Q8Vp7KoYa u5LA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=iutfgAEMr3aVnETDGpH220S0Jcsh/zdk3Pb7ajXb/+Q=; b=PX5QmyL+LnsLck0QEcIaOnnbEn2sO7Ly41dm7XDrN7eThYvQXjRH+cP3ezHfSbBXCA 0gGSL2KCGjEandG55zNSecErW0/MPw/wup6eH8bmnmyoUe/2CNHrSUytctcAbwAswfTZ hbAFF4uWhY59PmkYKgsYjFqlEazgA1TZEhzINzXCMomfPnIX8HzgeQ49Z6uRno8Qswet YZ6pYIox8qee8NG8NjBY8KUutRHLHFijcz6/4NGIjO5renoREQaa5hBaqRH/AoXDckip QbNyVoNd0liZdoj6Q3rLtdniuY7KK7GfdpPm33dCm4Fi6s2jLg1q5dS0MJg/pHXs2ViV jysg== X-Gm-Message-State: ANhLgQ3+oDm7XjAVzwz3zMdP5qOcueciGrhW/F06zi7g9LeAdrtbciN7 NBuoIwy0YOGnd0/VjfbNmFocvA== X-Google-Smtp-Source: ADFU+vszJlCQlH8uGs6tDDPH5jgNe2yuSVEB+jC8VaV64tQe6uSeKkPTUlv574C/T6c1WCdCf8PiKQ== X-Received: by 2002:a65:5b49:: with SMTP id y9mr21836208pgr.153.1585739742212; Wed, 01 Apr 2020 04:15:42 -0700 (PDT) Received: from localhost ([103.195.202.232]) by smtp.gmail.com with ESMTPSA id u41sm1277117pgn.8.2020.04.01.04.15.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Apr 2020 04:15:41 -0700 (PDT) From: Amit Kucheria To: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, swboyd@chromium.org, lukasz.luba@arm.com, mka@chromium.org, daniel.lezcano@linaro.org, Amit Kucheria , Zhang Rui Cc: Rob Herring , linux-pm@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH v4 2/3] dt-bindings: thermal: Add yaml bindings for thermal cooling-devices Date: Wed, 1 Apr 2020 16:45:26 +0530 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org As part of moving the thermal bindings to YAML, split it up into 3 bindings: thermal sensors, cooling devices and thermal zones. The property #cooling-cells is required in each device that acts as a cooling device - whether active or passive. So any device that can throttle its performance to passively reduce heat dissipation (e.g. cpus, gpus) and any device that can actively dissipate heat at different levels (e.g. fans) will contain this property. Signed-off-by: Amit Kucheria Reviewed-by: Rob Herring Reviewed-by: Lukasz Luba --- Changes since v3: - Clarify example by using cooling state numbers and a comment .../thermal/thermal-cooling-devices.yaml | 116 ++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml diff --git a/Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml b/Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml new file mode 100644 index 0000000000000..0dc4a743a1351 --- /dev/null +++ b/Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml @@ -0,0 +1,116 @@ +# SPDX-License-Identifier: (GPL-2.0) +# Copyright 2020 Linaro Ltd. +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/thermal/thermal-cooling-devices.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Thermal cooling device binding + +maintainers: + - Amit Kucheria + +description: | + Thermal management is achieved in devicetree by describing the sensor hardware + and the software abstraction of cooling devices and thermal zones required to + take appropriate action to mitigate thermal overload. + + The following node types are used to completely describe a thermal management + system in devicetree: + - thermal-sensor: device that measures temperature, has SoC-specific bindings + - cooling-device: device used to dissipate heat either passively or artively + - thermal-zones: a container of the following node types used to describe all + thermal data for the platform + + This binding describes the cooling devices. + + There are essentially two ways to provide control on power dissipation: + - Passive cooling: by means of regulating device performance. A typical + passive cooling mechanism is a CPU that has dynamic voltage and frequency + scaling (DVFS), and uses lower frequencies as cooling states. + - Active cooling: by means of activating devices in order to remove the + dissipated heat, e.g. regulating fan speeds. + + Any cooling device has a range of cooling states (i.e. different levels of + heat dissipation). They also have a way to determine the state of cooling in + which the device is. For example, a fan's cooling states correspond to the + different fan speeds possible. Cooling states are referred to by single + unsigned integers, where larger numbers mean greater heat dissipation. The + precise set of cooling states associated with a device should be defined in + a particular device's binding. + +select: true + +properties: + "#cooling-cells": + description: + Must be 2, in order to specify minimum and maximum cooling state used in + the cooling-maps reference. The first cell is the minimum cooling state + and the second cell is the maximum cooling state requested. + const: 2 + +examples: + - | + #include + #include + + // Example 1: Cpufreq cooling device on CPU0 + cpus { + #address-cells = <2>; + #size-cells = <0>; + + CPU0: cpu@0 { + device_type = "cpu"; + compatible = "qcom,kryo385"; + reg = <0x0 0x0>; + enable-method = "psci"; + cpu-idle-states = <&LITTLE_CPU_SLEEP_0 + &LITTLE_CPU_SLEEP_1 + &CLUSTER_SLEEP_0>; + capacity-dmips-mhz = <607>; + dynamic-power-coefficient = <100>; + qcom,freq-domain = <&cpufreq_hw 0>; + #cooling-cells = <2>; + next-level-cache = <&L2_0>; + L2_0: l2-cache { + compatible = "cache"; + next-level-cache = <&L3_0>; + L3_0: l3-cache { + compatible = "cache"; + }; + }; + }; + + /* ... */ + + }; + + /* ... */ + + thermal-zones { + cpu0-thermal { + polling-delay-passive = <250>; + polling-delay = <1000>; + + thermal-sensors = <&tsens0 1>; + + trips { + cpu0_alert0: trip-point0 { + temperature = <90000>; + hysteresis = <2000>; + type = "passive"; + }; + }; + + cooling-maps { + map0 { + trip = <&cpu0_alert0>; + /* Corresponds to 1000MHz in OPP table */ + cooling-device = <&CPU0 5 5>; + }; + }; + }; + + /* ... */ + }; +...