From patchwork Mon Feb 24 07:25:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Kucheria X-Patchwork-Id: 11399475 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 1DF9614D5 for ; Mon, 24 Feb 2020 07:25:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E6D3C2082E for ; Mon, 24 Feb 2020 07:25:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="tjniMdRQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727329AbgBXHZz (ORCPT ); Mon, 24 Feb 2020 02:25:55 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:37674 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727310AbgBXHZw (ORCPT ); Mon, 24 Feb 2020 02:25:52 -0500 Received: by mail-pj1-f68.google.com with SMTP id m13so3772933pjb.2 for ; Sun, 23 Feb 2020 23:25:51 -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=tjniMdRQcswz61KyutEoTh6PTFVjC1qxxE8fl7j0YkHZ+Hx+tuPlXr/PwYw5oFsB7N g45d0Xqy3xjQdUKxgoTBYHCzA52ywyhVkMae3eEqCypYoYbyE3pgECywvbOl9B1jimB+ JFq/9qyI+7Af6dHHhU5DkGGcaec2O89jGT1gDtIOLL/WXrKbu9EQScDIBpMWl94WIrCK ao8ggp/NWmmcKB7CyZvD/gXmk1P0HzSwloeyX1qYDfBqzlVwSUqdm+IY4pzjuXuqPej8 ILb6Ui+EOX7VgkxCkYqgSl3sRsfDiFEtHgUMy+ILcxAn2b3MiL20ev7QL2f0ZdK75cUi re+Q== 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=fFut651lEPM7RZR/OThmj+U2RP40I5gEHXauazKTOT49qI98coignA9uvoGSQpZN0x mX22R3BVWtvl8zcfKPBRAXg6r24a1mC6UWy5heWaOqB1DMHIWPFkXrcPbaXyACj9hS2+ ifRAiysUce4w0bG1II4hmIMwF0+oyyFdPhvurlZVfq6v8u0ldpnX/33uxs20W5tsgMgW K8sUZBJ+7B40e12j5jJ+njlo7LCfZnglMIEpcC/CYJ98Q2VsZ//wbz7MdzFNpbMq36l7 dBfC4sUgWSoMTuDFT50X5R2X8DLbWBn4DjtdOWEacV9DQrrVYYbpO+eAIei82R2sfLw+ A5GQ== X-Gm-Message-State: APjAAAX9KP1xffrQQZgrxBgf3vo4oxh03jjBcdYRz3N2vLlFcCrvrXZj XFJdfTjLi6dPn0BEmFYU30JKAQ== X-Google-Smtp-Source: APXvYqzc/UxqWrw78Wyigaf18Y92PdErXwfLqoPnL2avooGuba1Fui3e6A0h0YKrb6IJKRUFAJUP9Q== X-Received: by 2002:a17:90a:8547:: with SMTP id a7mr19686083pjw.0.1582529150479; Sun, 23 Feb 2020 23:25:50 -0800 (PST) Received: from localhost ([45.127.44.57]) by smtp.gmail.com with ESMTPSA id 199sm11508299pfu.71.2020.02.23.23.25.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 23 Feb 2020 23:25:49 -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 v1 2/3] dt-bindings: thermal: Add yaml bindings for thermal cooling-devices Date: Mon, 24 Feb 2020 12:55:36 +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 --- .../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>; + }; + }; + }; + + /* ... */ + }; +...