From patchwork Mon Feb 24 07:20:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Kucheria X-Patchwork-Id: 11399457 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 43C52924 for ; Mon, 24 Feb 2020 07:20:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16FB52080D for ; Mon, 24 Feb 2020 07:20:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="tX4PPsoA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727281AbgBXHUm (ORCPT ); Mon, 24 Feb 2020 02:20:42 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:42553 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727268AbgBXHUk (ORCPT ); Mon, 24 Feb 2020 02:20:40 -0500 Received: by mail-pf1-f193.google.com with SMTP id 4so4880178pfz.9 for ; Sun, 23 Feb 2020 23:20:39 -0800 (PST) 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=d17BUbT9BeIhozRgLya99QrlVVsu5JDoV05HFzpYDyI=; b=tX4PPsoAZ93qYdTGJqfLDnzMCWiEL3N5LumrMh2+TNF6m+7oLL1F/EyrLxp8necb50 lRiepTn9LHb9aWKxBomyH/Iaa5/v51oKIB//XnqfstKAsBTut8pSKd8fdWs8xwQHuUzg 8o8wlUgtf2HJvHwcJejj/aPFf+g3iMDcY0O67nMuaj7aUtWswClNLW6mdlG5ThzeAwGH 0hDVabld3B5XHbNQebcc4dJ/nHLD0T+lP0B+OHv/3fY0gKFH+tcRw0zKkySPCCZ5OM9d f8Z8PibHVvKo9ab7zuC/u8JhdzJ33I3KimAGvdJenvKTatQ6EbleVbIYNofJR8XYYF1O FALw== 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=d17BUbT9BeIhozRgLya99QrlVVsu5JDoV05HFzpYDyI=; b=KBMOWPHX/zRHiP396WhJHKavocAySsyLmE9oMHpUTpgpWtK25nIgkrHO+ai5vzFLg4 HAtisslG27lX5bHKDv5SNH/0PstwH6q4orTs5RsHVDyQk/Q/lIpme2lzt32IrF7oLOtg mazIH5iCyeJ3OIiLzd4b/Ec3mfRWntoNRZGp7NUqMptPYEpwVNZIq4FA0lZ6ZRO5NQzw yMrWk8Jo4H4GWY24i9/+Z8S2u2wj3EZHZ6kZQc3gYWFEb5S09TEEGlpo3NeRNyIwgmWb wb3IOnjFH5y9CFXFUCVndsEoCBptHoJ0dkRWRJHU2qEagk0K4vb8O6Zao/9JDti3bYvt JZxw== X-Gm-Message-State: APjAAAUspqq4j4DqEPXxUFFFucuvAd8+2/0cuEb6lrqsjPwdndxt64sh EZ1c6IvGeuWgjp6q+UBrVjrCiw== X-Google-Smtp-Source: APXvYqzkJT+9NfIMSJwyBdAUhvFLgxMSJMdeZTpH6ySLbj3mVts+tjLm4Pji5DqLD/oefGUw4ie0hg== X-Received: by 2002:aa7:86c2:: with SMTP id h2mr50096222pfo.45.1582528839386; Sun, 23 Feb 2020 23:20:39 -0800 (PST) Received: from localhost ([45.127.44.57]) by smtp.gmail.com with ESMTPSA id p24sm11375421pff.69.2020.02.23.23.20.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 23 Feb 2020 23:20:38 -0800 (PST) From: Amit Kucheria To: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, swboyd@chromium.org, mka@chromium.org, daniel.lezcano@linaro.org, Amit Kucheria , Zhang Rui Cc: linux-pm@vger.kernel.org, devicetree@vger.kernel.org Subject: [RFC PATCH v5 2/3] dt-bindings: thermal: Add yaml bindings for thermal cooling-devices Date: Mon, 24 Feb 2020 12:50:26 +0530 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@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 --- .../thermal/thermal-cooling-devices.yaml | 114 ++++++++++++++++++ 1 file changed, 114 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 000000000000..6aafca25af9b --- /dev/null +++ b/Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml @@ -0,0 +1,114 @@ +# SPDX-License-Identifier: (GPL-2.0 OR MIT) +# 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. + +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>; + cooling-device = <&CPU0 THERMAL_NO_LIMIT + THERMAL_NO_LIMIT>; + }; + }; + }; + + /* ... */ + }; +...