Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756175Ab3JGUva (ORCPT ); Mon, 7 Oct 2013 16:51:30 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:53657 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754368Ab3JGUv1 (ORCPT ); Mon, 7 Oct 2013 16:51:27 -0400 Date: Mon, 7 Oct 2013 21:51:21 +0100 From: Mark Rutland To: Eduardo Valentin , "swarren@wwwdotorg.org" , Pawel Moll , "ian.campbell@citrix.com" , "rob.herring@calxeda.com" , "grant.likely@linaro.org" Cc: "linux@roeck-us.net" , "rui.zhang@intel.com" , "wni@nvidia.com" , "durgadoss.r@intel.com" , "linux-pm@vger.kernel.org" , "devicetree@vger.kernel.org" , "lm-sensors@lm-sensors.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCHv8 03/18] thermal: introduce device tree parser Message-ID: <20131007205120.GA2330@kartoffel> References: <1380251605-3804-4-git-send-email-eduardo.valentin@ti.com> <1380595166-13807-1-git-send-email-eduardo.valentin@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1380595166-13807-1-git-send-email-eduardo.valentin@ti.com> Thread-Topic: [PATCHv8 03/18] thermal: introduce device tree parser Accept-Language: en-GB, en-US Content-Language: en-US acceptlanguage: en-GB, en-US User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 66016 Lines: 1769 Hi all, Given that this is a complex new class of binding, I'd appreciate if at least one other device tree maintainer could also take a look over this and voice any concerns or suggestions. I've left the entire patch context for this. Apologies for the munged whitespace -- my mail server appears to have helpfully and irreparably replaced all tabs with spaces. On Tue, Oct 01, 2013 at 03:39:26AM +0100, Eduardo Valentin wrote: > This patch introduces a device tree bindings for > describing the hardware thermal behavior and limits. > Also a parser to read and interpret the data and feed > it in the thermal framework is presented. > > This patch introduces a thermal data parser for device > tree. The parsed data is used to build thermal zones > and thermal binding parameters. The output data > can then be used to deploy thermal policies. > > This patch adds also documentation regarding this > API and how to define tree nodes to use > this infrastructure. > > Note that, in order to be able to have control > on the sensor registration on the DT thermal zone, > it was required to allow changing the thermal zone > .get_temp callback. For this reason, this patch > also removes the 'const' modifier from the .ops > field of thermal zone devices. > > Cc: Zhang Rui > Cc: linux-pm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Eduardo Valentin > --- > Hello Mark, folks, > > So, here is v8. Pretty small changes. Most are better > English phrasing in the binding document. It follows changelog: > - Several rephrasing in the binding document, including > spelling, grammar and better phrasing. > - Removed WiP warning from binding document. > - Several spacing and formatting changes in the binding document > - Used the '-specifier' nomenclature properly in the binding doc > - Removed the optional property 'thermal-sensors-names', because > it does not provide useful runtime information > - Fixed description of 'polling-delay-passive' > - Improved examples by adding comments and better explanation > - s/fw/framework/g > - Added a WARN when sensors specifiers are greater and 1. > > All best, > > Eduardo > > --- > .../devicetree/bindings/thermal/thermal.txt | 587 ++++++++++++++ > drivers/thermal/Kconfig | 13 + > drivers/thermal/Makefile | 1 + > drivers/thermal/of-thermal.c | 849 +++++++++++++++++++++ > drivers/thermal/thermal_core.c | 9 +- > drivers/thermal/thermal_core.h | 9 + > include/dt-bindings/thermal/thermal.h | 27 + > include/linux/thermal.h | 28 +- > 8 files changed, 1520 insertions(+), 3 deletions(-) > create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt > create mode 100644 drivers/thermal/of-thermal.c > create mode 100644 include/dt-bindings/thermal/thermal.h > > diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt > new file mode 100644 > index 0000000..ad06a8d > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/thermal.txt > @@ -0,0 +1,587 @@ > +* Thermal Framework Device Tree descriptor > + > +This file describes a generic binding to provide a way of > +defining hardware thermal structure using device tree. s/defining/describing/ > +A thermal structure includes thermal zones and their components, > +such as trip points, polling intervals, sensors and cooling devices > +binding descriptors. > + > +The target of device tree thermal descriptors is to describe only > +the hardware thermal aspects. The thermal device tree bindings are > +not about how the system must control or which algorithm or policy > +must be taken in place. I'm not quite sure what this is saying -- it seems to contradict the design of the binding where trip points get linked to cooling device configuration, and thus we're defining a policy along the lines of "when sensor $W hits temperature $X, configure cooling device $Y with value $Z". I don't see how that can't be considered policy. At best, we can say that policy is being defined because describing the physical properties of a device and dealing with this at runtime is not feasible. > + > +There are five types of nodes involved to describe thermal bindings: > +- sensors: used to describe the device source of temperature sensing; - thermal sensors: devices which may be used to take temperature measurements. > +- cooling devices: used to describe devices source of power dissipation control; - cooling devices: devices which may be used to dissipate heat. > +- trip points: used to describe points in temperature domain defined to > +make the system aware of hardware limits; - trip points: describe key temperatures at which cooling is recommended. The set of points should be chosen based on hardware limits. > +- cooling maps: used to describe links between trip points and cooling devices; > +- thermal zones: used to describe thermal data within the hardware; > + > +It follows a description of each type of these device tree nodes. How about: The following is a description of each of these node types. > + > +* Thermal sensor devices > + > +Thermal sensor devices are nodes providing temperature sensing capabilities on > +thermal zones. Typical devices are I2C ADC converters and bandgaps. These are > +nodes providing temperature data to thermal zones. Thermal sensor devices may > +control one or more internal sensors. > + > +Required property: > +- #thermal-sensor-cells: Used to provide sensor device specific information > + Type: unsigned while referring to it. Typically 0 on thermal sensor > + Size: one cell nodes with only one sensor, and at least 1 on nodes > + with several internal sensors, in order > + to identify uniquely the sensor instances within > + the IC. See thermal zone binding for more details > + on how consumers refer to sensor devices. > + > +* Cooling device nodes > + > +Cooling devices are nodes providing control on power dissipation. There > +are essentially two ways to provide control on power dissipation. First > +is by means of regulating device performance, which is known as passive > +cooling. A typical passive cooling is a CPU that has dynamic voltage and > +frequency scaling (DVFS), and uses lower frequencies as cooling states. > +Second is by means of activating devices in order to remove > +the dissipated heat, which is known as active cooling, e.g. regulating > +fan speeds. In both cases, cooling devices shall have a way to determine > +the state of cooling in which the device is. I'd probably say "heat dissipation" rather than "power dissipation", unless this is a technical term I am not aware of? Why is the determination of the state of the cooling device important? > + > +Required properties: > +- cooling-min-state: An integer indicating the smallest > + Type: unsigned cooling state accepted. Typically 0. > + Size: one cell > + > +- cooling-max-state: An integer indicating the largest > + Type: unsigned cooling state accepted. > + Size: one cell > + > +- #cooling-cells: Used to provide cooling device specific information > + Type: unsigned while referring to it. Must be at least 2, in order > + Size: one cell to specify minimum and maximum cooling state used > + in the reference. The first cell is the minimum > + cooling state requested and the second cell is > + the maximum cooling state requested in the reference. > + See Cooling device maps section below for more details > + on how consumers refer to cooling devices. Is it assumed that all the values between min and max are valid, or might this be a sparse set of cooling values? > + > +* Trip points > + > +The trip node is a node to describe a point in the temperature domain > +in which the system takes an action. This node describes just the point, > +not the action. > + > +Required properties: > +- temperature: An integer indicating the trip temperature level, > + Type: signed in millicelsius. > + Size: one cell > + > +- hysteresis: a (low) hysteresis value on 'temperature'. This is a > + Type: unsigned relative value, in millicelsius. > + Size: one cell What is it relative to? Why is 'temperature' in quotes? > + > +- type: a string containing the trip type. Supported values are: > + "active": A trip point to enable active cooling > + "passive": A trip point to enable passive cooling > + "hot": A trip point to notify emergency > + "critical": Hardware not reliable. > + Type: string > + > +There are also string constants defined at > +include/dt-bindings/thermal/thermal.h. Why? > + > +* Cooling device maps > + > +The cooling device maps node is a node to describe how cooling devices > +get assigned to trip points of the zone. The cooling devices are expected > +to be loaded in the target system. > + > +Required properties: > +- cooling-device: A phandle of a cooling device with its specifier, > + Type: phandle of referring to which cooling device is used in this > + cooling device binding. In the cooling specifier, the first cell > + is the minimum cooling state and the second cell > + is the maximum cooling state used in this map. The type is wrong here -- it's a phandle + cooling-cells, not just a phandle. > +- trip: A phandle of a trip point node within the same thermal > + Type: phandle of zone. > + trip point node > + > +Optional property: > +- contribution: The cooling contribution to the thermal zone of the > + Type: unsigned referred cooling device at the referred trip point. > + Size: one cell The contribution is a ratio of the sum > + of all cooling contributions within a thermal zone. > + > +Note: Using the THERMAL_NO_LIMIT (-1UL) constant in the cooling-device phandle > +limit specifier means: > +(i) - minimum state allowed for minimum cooling state used in the reference. > +(ii) - maximum state allowed for maximum cooling state used in the reference. > +Refer to include/dt-bindings/thermal/thermal.h for definition of this constant. > + > +* Thermal zone nodes > + > +The thermal zone node is the node containing all the required info > +for describing a thermal zone, including its cooling device bindings. The > +thermal zone node must contain, apart from its own properties, one sub-node > +containing trip nodes and one sub-node containing all the zone cooling maps. > + > +Required properties: > +- polling-delay: The maximum number of milliseconds to wait between polls > + Type: unsigned when checking this thermal zone. > + Size: one cell > + > +- polling-delay-passive: The maximum number of milliseconds to wait > + Type: unsigned between polls when performing passive cooling. > + Size: one cell > + > +- thermal-sensors: A list of thermal sensor phandles and sensor specifier > + Type: list of used while monitoring the thermal zone. > + sensor phandles The type is wrong here. A list of phandle + sensor specifiers. > + > +- trips: A sub-node which is a container of only trip point nodes > + Type: sub-node required to describe the thermal zone. > + > +- cooling-maps: A sub-node which is a container of only cooling device > + Type: sub-node map nodes, used to describe the relation between trips > + and cooling devices. > + > +Optional property: > +- coefficients: An array of integers (one signed cell) containing > + Type: array coefficients to compose a linear relation between > + Elem size: one cell the sensors listed in the thermal-sensors property. > + Elem type: signed Coefficients defaults to 1, in case this property > + is not specified. A simple linear polynomial is used: > + Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn. > + > + The coefficients are ordered and they match with sensors > + by means of sensor ID. Additional coefficients are > + interpreted as constant offset. > + > +Note: The delay properties are bound to the maximum dT/dt (temperature > +derivative over time) in two situations for a thermal zone: > +(i) - when passive cooling is activated (polling-delay-passive); and > +(ii) - when the zone just needs to be monitored (polling-delay) or > +when active cooling is activated. > + > +The maximum dT/dt is highly bound to hardware power consumption and dissipation > +capability. The delays should be chosen to account for said max dT/dt, > +such that a device does not cross several trip boundaries unexpectedly > +between polls. Choosing the right polling delays shall avoid having the > +device in temperature ranges that may damage the silicon structures and > +reduce silicon lifetime. > + > +* The thermal-zones node > + > +The "thermal-zones" node is a container for all thermal zone nodes. It shall > +contain only sub-nodes describing thermal zones as in the section > +"Thermal zone nodes". The "thermal-zones" node appears under "/". > + > +* Examples > + > +Below are several examples on how to use thermal data descriptors > +using device tree bindings: > + > +(a) - CPU thermal zone > + > +The CPU thermal zone example below describes how to setup one thermal zone > +using one single sensor as temperature source and many cooling devices and > +power dissipation control sources. > + > +#include > + > +cpus { > + /* > + * Here is an example of describing a cooling device for a DVFS > + * capable CPU. The CPU node describes its four OPPs. > + * The cooling states possible are 0..3, and they are > + * used as OPP indexes. The minimum cooling state is 0, which means > + * all four OPPs can be available to the system. The maximum > + * cooling state is 3, which means only the lowest OPPs (198MHz@0.85V) > + * can be available in the system. > + */ > + cpu0: cpu@0 { > + ... > + operating-points = < > + /* kHz uV */ > + 970000 1200000 > + 792000 1100000 > + 396000 950000 > + 198000 850000 > + >; > + cooling-min-state = <0>; > + cooling-max-state = <3>; > + #cooling-cells = <2>; /* min followed by max */ > + }; > + ... > +}; > + > +&i2c1 { > + ... > + /* > + * A simple fan controller which supports 10 speeds of operation > + * (represented as 0-9). > + */ > + fan0: fan@0x48 { > + ... > + cooling-min-state = <0>; > + cooling-max-state = <9>; > + #cooling-cells = <2>; /* min followed by max */ > + }; > +}; > + > +ocp { > + ... > + /* > + * A simple IC with a single bandgap temperature sensor. > + */ > + bandgap0: bandgap@0x0000ED00 { > + ... > + #thermal-sensor-cells = <0>; > + }; > +}; > + > +thermal-zones { > + cpu-thermal: cpu-thermal { > + polling-delay-passive = <250>; /* milliseconds */ > + polling-delay = <1000>; /* milliseconds */ > + > + thermal-sensors = <&bandgap0>; > + > + trips { > + cpu-alert0: cpu-alert { > + temperature = <90000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "active"; > + }; > + cpu-alert1: cpu-alert { > + temperature = <100000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + cpu-crit: cpu-crit { > + temperature = <125000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + map0 { > + trip = <&cpu-alert0>; > + cooling-device = <&fan0 THERMAL_NO_LIMITS 4>; > + }; > + map1 { > + trip = <&cpu-alert1>; > + cooling-device = <&fan0 5 THERMAL_NO_LIMITS>; > + }; > + map2 { > + trip = <&cpu-alert1>; > + cooling-device = > + <&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>; > + }; > + }; > + }; > +}; > + > +In the example above, the ADC sensor (bandgap0) at address 0x0000ED00 is > +used to monitor the zone 'cpu-thermal' using its sole sensor. A fan > +device (fan0) is controlled via I2C bus 1, at address 0x48, and has ten > +different cooling states 0-9. It is used to remove the heat out of > +the thermal zone 'cpu-thermal' using its cooling states > +from its minimum to 4, when it reaches trip point 'cpu-alert0' > +at 90C, as an example of active cooling. The same cooling device is used at > +'cpu-alert1', but from 5 to its maximum state. The cpu@0 device is also > +linked to the same thermal zone, 'cpu-thermal', as a passive cooling device, > +using all its cooling states at trip point 'cpu-alert1', > +which is a trip point at 100C. On the thermal zone 'cpu-thermal', at the > +temperature of 125C, represented by the trip point 'cpu-crit', the silicon > +is not reliable anymore. > + > +(b) - IC with several internal sensors > + > +The example below describes how to deploy several thermal zones based off a > +single sensor IC, assuming it has several internal sensors. This is a common > +case on SoC designs with several internal IPs that may need different thermal > +requirements, and thus may have their own sensor to monitor or detect internal > +hotspots in their silicon. > + > +#include > + > +ocp { > + ... > + /* > + * A simple IC with several bandgap temperature sensors. > + */ > + bandgap0: bandgap@0x0000ED00 { > + ... > + #thermal-sensor-cells = <1>; > + }; > +}; > + > +thermal-zones { > + cpu-thermal: cpu-thermal { > + polling-delay-passive = <250>; /* milliseconds */ > + polling-delay = <1000>; /* milliseconds */ > + > + /* sensor ID */ > + thermal-sensors = <&bandgap0 0>; > + > + trips { > + /* each zone within the SoC may have its own trips */ > + cpu-alert: cpu-alert { > + temperature = <100000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + cpu-crit: cpu-crit { > + temperature = <125000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + /* each zone within the SoC may have its own cooling */ > + ... > + }; > + }; > + > + gpu-thermal: gpu-thermal { > + polling-delay-passive = <120>; /* milliseconds */ > + polling-delay = <1000>; /* milliseconds */ > + > + /* sensor ID */ > + thermal-sensors = <&bandgap0 1>; > + > + trips { > + /* each zone within the SoC may have its own trips */ > + gpu-alert: gpu-alert { > + temperature = <90000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + gpu-crit: gpu-crit { > + temperature = <105000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + /* each zone within the SoC may have its own cooling */ > + ... > + }; > + }; > + > + dsp-thermal: dsp-thermal { > + polling-delay-passive = <50>; /* milliseconds */ > + polling-delay = <1000>; /* milliseconds */ > + > + /* sensor ID */ > + thermal-sensors = <&bandgap0 2>; > + > + trips { > + /* each zone within the SoC may have its own trips */ > + dsp-alert: gpu-alert { > + temperature = <90000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + dsp-crit: gpu-crit { > + temperature = <135000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + /* each zone within the SoC may have its own cooling */ > + ... > + }; > + }; > +}; > + > +In the example above, there is one bandgap IC which has the capability to > +monitor three sensors. The hardware has been designed so that sensors are > +placed on different places in the DIE to monitor different temperature > +hotspots: one for CPU thermal zone, one for GPU thermal zone and the > +other to monitor a DSP thermal zone. > + > +Thus, there is a need to assign each sensor provided by the bandgap IC > +to different thermal zones. This is achieved by means of using the > +#thermal-sensor-cells property and using the first cell of the sensor > +specifier as sensor ID. In the example, then, is used to > +monitor CPU thermal zone, is used to monitor GPU thermal > +zone and is used to monitor DSP thermal zone. Each zone > +may be uncorrelated, having its own dT/dt requirements, trips > +and cooling maps. > + > + > +(c) - Several sensors within one single thermal zone > + > +The example below illustrates how to use more than one sensor within > +one thermal zone. > + > +#include > + > +&i2c1 { > + ... > + /* > + * A simple IC with a single temperature sensor. > + */ > + adc: sensor@0x49 { > + ... > + #thermal-sensor-cells = <0>; > + }; > +}; > + > +ocp { > + ... > + /* > + * A simple IC with a single bandgap temperature sensor. > + */ > + bandgap0: bandgap@0x0000ED00 { > + ... > + #thermal-sensor-cells = <0>; > + }; > +}; > + > +thermal-zones { > + cpu-thermal: cpu-thermal { > + polling-delay-passive = <250>; /* milliseconds */ > + polling-delay = <1000>; /* milliseconds */ > + > + thermal-sensors = <&bandgap0>, /* cpu */ > + <&adc>; /* pcb north */ > + > + /* hotspot = 100 * bandgap - 120 * adc + 484 */ > + coefficients = <100 -120 484>; > + > + trips { > + ... > + }; > + > + cooling-maps { > + ... > + }; > + }; > +}; > + > +In some cases, there is a need to use more than one sensor to extrapolate > +a thermal hotspot in the silicon. The above example illustrates this situation. > +For instance, it may be the case that a sensor external to CPU IP may be placed > +close to CPU hotspot and together with internal CPU sensor, it is used > +to determine the hotspot. Assuming this is the case for the above example, > +the hypothetical extrapolation rule would be: > + hotspot = 100 * bandgap - 120 * adc + 484 > + > +In other context, the same idea can be used to add fixed offset. For instance, > +consider the hotspot extrapolation rule below: > + hotspot = 1 * adc + 6000 > + > +In the above equation, the hotspot is always 6C higher than what is read > +from the ADC sensor. The binding would be then: > + thermal-sensors = <&adc>; > + > + /* hotspot = 1 * adc + 6000 */ > + coefficients = <1 6000>; > + > +(d) - Board thermal > + > +The board thermal example below illustrates how to setup one thermal zone > +with many sensors and many cooling devices. > + > +#include > + > +&i2c1 { > + ... > + /* > + * An IC with several temperature sensor. > + */ > + adc-dummy: sensor@0x50 { > + ... > + #thermal-sensor-cells = <1>; /* sensor internal ID */ > + }; > +}; > + > +thermal-zones { > + batt-thermal { > + polling-delay-passive = <500>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + /* sensor ID */ > + thermal-sensors = <&adc-dummy 4>; > + > + trips { > + ... > + }; > + > + cooling-maps { > + ... > + }; > + }; > + > + board-thermal: board-thermal { > + polling-delay-passive = <1000>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + /* sensor ID */ > + thermal-sensors = <&adc-dummy 0>, /* pcb top edge */ > + <&adc-dummy 1>, /* lcd */ > + <&adc-dymmy 2>; /* back cover */ > + /* > + * An array of coefficients describing the sensor > + * linear relation. E.g.: > + * z = c1*x1 + c2*x2 + c3*x3 > + */ > + coefficients = <1200 -345 890>; > + > + trips { > + /* Trips are based on resulting linear equation */ > + cpu-trip: cpu-trip { > + temperature = <60000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + gpu-trip: gpu-trip { > + temperature = <55000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + } > + lcd-trip: lcp-trip { > + temperature = <53000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + crit-trip: crit-trip { > + temperature = <68000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + map0 { > + trip = <&cpu-trip>; > + cooling-device = <&cpu0 0 2>; > + contribution = <55>; > + }; > + map1 { > + trip = <&gpu-trip>; > + cooling-device = <&gpu0 0 2>; > + contribution = <20>; > + }; > + map2 { > + trip = <&lcd-trip>; > + cooling-device = <&lcd0 5 10>; > + contribution = <15>; > + }; > + }; > + }; > +}; > + > +The above example is a mix of previous examples, a sensor IP with several internal > +sensors used to monitor different zones, one of them is composed by several sensors and > +with different cooling devices. > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index dbfc390..dd81eb8 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -29,6 +29,19 @@ config THERMAL_HWMON > Say 'Y' here if you want all thermal sensors to > have hwmon sysfs interface too. > > +config THERMAL_OF > + bool > + prompt "APIs to parse thermal data out of device tree" > + depends on OF > + default y > + help > + This options provides helpers to add the support to > + read and parse thermal data definitions out of the > + device tree blob. > + > + Say 'Y' here if you need to build thermal infrastructure > + based on device tree. > + > choice > prompt "Default Thermal governor" > default THERMAL_DEFAULT_GOV_STEP_WISE > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 584b363..4b03956 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -7,6 +7,7 @@ thermal_sys-y += thermal_core.o > > # interface to/from other layers providing sensors > thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o > +thermal_sys-$(CONFIG_THERMAL_OF) += of-thermal.o > > # governors > thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o > diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c > new file mode 100644 > index 0000000..66f9eb2 > --- /dev/null > +++ b/drivers/thermal/of-thermal.c > @@ -0,0 +1,849 @@ > +/* > + * of-thermal.c - Generic Thermal Management device tree support. > + * > + * Copyright (C) 2013 Texas Instruments > + * Copyright (C) 2013 Eduardo Valentin > + * > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, write to the Free Software Foundation, Inc., > + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "thermal_core.h" > + > +/*** Private data structures to represent thermal device tree data ***/ > + > +/** > + * struct __thermal_trip - representation of a point in temperature domain > + * @np: pointer to struct device_node that this trip point was created from > + * @temperature: temperature value in miliCelsius > + * @hysteresis: relative hysteresis in miliCelsius > + * @type: trip point type > + */ > + > +struct __thermal_trip { > + struct device_node *np; > + unsigned long int temperature; > + unsigned long int hysteresis; > + enum thermal_trip_type type; > +}; > + > +/** > + * struct __thermal_bind_param - a match between trip and cooling device > + * @cooling_device: a pointer to identify the referred cooling device > + * @trip_id: the trip point index > + * @usage: the percentage (from 0 to 100) of cooling contribution > + * @min: minimum cooling state used at this trip point > + * @max: maximum cooling state used at this trip point > + */ > + > +struct __thermal_bind_params { > + struct device_node *cooling_device; > + unsigned int trip_id; > + unsigned int usage; > + unsigned long min; > + unsigned long max; > +}; > + > +/** > + * struct __thermal_zone - internal representation of a thermal zone > + * @mode: current thermal zone device mode (enabled/disabled) > + * @passive_delay: polling interval while passive cooling is activated > + * @polling_delay: zone polling interval > + * @ntrips: number of trip points > + * @trips: an array of trip points (0..ntrips - 1) > + * @num_tbps: number of thermal bind params > + * @tbps: an array of thermal bind params (0..num_tbps - 1) > + * @sensor_data: sensor private data used while reading temperature and trend > + * @get_temp: sensor callback to read temperature > + * @get_trend: sensor callback to read temperature trend > + */ > + > +struct __thermal_zone { > + enum thermal_device_mode mode; > + int passive_delay; > + int polling_delay; > + > + /* trip data */ > + int ntrips; > + struct __thermal_trip *trips; > + > + /* cooling binding data */ > + int num_tbps; > + struct __thermal_bind_params *tbps; > + > + /* sensor interface */ > + void *sensor_data; > + int (*get_temp)(void *, long *); > + int (*get_trend)(void *, long *); > +}; > + > +/*** DT thermal zone device callbacks ***/ > + > +static int of_thermal_get_temp(struct thermal_zone_device *tz, > + unsigned long *temp) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (!data->get_temp) > + return -EINVAL; > + > + return data->get_temp(data->sensor_data, temp); > +} > + > +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip, > + enum thermal_trend *trend) > +{ > + struct __thermal_zone *data = tz->devdata; > + long dev_trend; > + int r; > + > + if (!data->get_trend) > + return -EINVAL; > + > + r = data->get_trend(data->sensor_data, &dev_trend); > + if (r) > + return r; > + > + /* TODO: These intervals might have some thresholds, but in core code */ > + if (dev_trend > 0) > + *trend = THERMAL_TREND_RAISING; > + else if (dev_trend < 0) > + *trend = THERMAL_TREND_DROPPING; > + else > + *trend = THERMAL_TREND_STABLE; > + > + return 0; > +} > + > +static int of_thermal_bind(struct thermal_zone_device *thermal, > + struct thermal_cooling_device *cdev) > +{ > + struct __thermal_zone *data = thermal->devdata; > + int i; > + > + if (!data || IS_ERR(data)) > + return -ENODEV; > + > + /* find where to bind */ > + for (i = 0; i < data->num_tbps; i++) { > + struct __thermal_bind_params *tbp = data->tbps + i; > + > + if (tbp->cooling_device == cdev->np) { > + int ret; > + > + ret = thermal_zone_bind_cooling_device(thermal, > + tbp->trip_id, cdev, > + tbp->min, > + tbp->max); > + if (ret) > + return ret; > + } > + } > + > + return 0; > +} > + > +static int of_thermal_unbind(struct thermal_zone_device *thermal, > + struct thermal_cooling_device *cdev) > +{ > + struct __thermal_zone *data = thermal->devdata; > + int i; > + > + if (!data || IS_ERR(data)) > + return -ENODEV; > + > + /* find where to unbind */ > + for (i = 0; i < data->num_tbps; i++) { > + struct __thermal_bind_params *tbp = data->tbps + i; > + > + if (tbp->cooling_device == cdev->np) { > + int ret; > + > + ret = thermal_zone_unbind_cooling_device(thermal, > + tbp->trip_id, cdev); > + if (ret) > + return ret; > + } > + } > + > + return 0; > +} > + > +static int of_thermal_get_mode(struct thermal_zone_device *tz, > + enum thermal_device_mode *mode) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + *mode = data->mode; > + > + return 0; > +} > + > +static int of_thermal_set_mode(struct thermal_zone_device *tz, > + enum thermal_device_mode mode) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + mutex_lock(&tz->lock); > + > + if (mode == THERMAL_DEVICE_ENABLED) > + tz->polling_delay = data->polling_delay; > + else > + tz->polling_delay = 0; > + > + mutex_unlock(&tz->lock); > + > + data->mode = mode; > + thermal_zone_device_update(tz); > + > + return 0; > +} > + > +static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip, > + enum thermal_trip_type *type) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (trip >= data->ntrips || trip < 0) > + return -EDOM; > + > + *type = data->trips[trip].type; > + > + return 0; > +} > + > +static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip, > + unsigned long *temp) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (trip >= data->ntrips || trip < 0) > + return -EDOM; > + > + *temp = data->trips[trip].temperature; > + > + return 0; > +} > + > +static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip, > + unsigned long temp) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (trip >= data->ntrips || trip < 0) > + return -EDOM; > + > + /* thermal framework should take care of data->mask & (1 << trip) */ > + data->trips[trip].temperature = temp; > + > + return 0; > +} > + > +static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip, > + unsigned long *hyst) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (trip >= data->ntrips || trip < 0) > + return -EDOM; > + > + *hyst = data->trips[trip].hysteresis; > + > + return 0; > +} > + > +static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip, > + unsigned long hyst) > +{ > + struct __thermal_zone *data = tz->devdata; > + > + if (trip >= data->ntrips || trip < 0) > + return -EDOM; > + > + /* thermal framework should take care of data->mask & (1 << trip) */ > + data->trips[trip].hysteresis = hyst; > + > + return 0; > +} > + > +static int of_thermal_get_crit_temp(struct thermal_zone_device *tz, > + unsigned long *temp) > +{ > + struct __thermal_zone *data = tz->devdata; > + int i; > + > + for (i = 0; i < data->ntrips; i++) > + if (data->trips[i].type == THERMAL_TRIP_CRITICAL) { > + *temp = data->trips[i].temperature; > + return 0; > + } > + > + return -EINVAL; > +} > + > +static struct thermal_zone_device_ops of_thermal_ops = { > + .get_mode = of_thermal_get_mode, > + .set_mode = of_thermal_set_mode, > + > + .get_trip_type = of_thermal_get_trip_type, > + .get_trip_temp = of_thermal_get_trip_temp, > + .set_trip_temp = of_thermal_set_trip_temp, > + .get_trip_hyst = of_thermal_get_trip_hyst, > + .set_trip_hyst = of_thermal_set_trip_hyst, > + .get_crit_temp = of_thermal_get_crit_temp, > + > + .bind = of_thermal_bind, > + .unbind = of_thermal_unbind, > +}; > + > +/*** sensor API ***/ > + > +static struct thermal_zone_device * > +thermal_zone_of_add_sensor(struct device_node *zone, > + struct device_node *sensor, void *data, > + int (*get_temp)(void *, long *), > + int (*get_trend)(void *, long *)) > +{ > + struct thermal_zone_device *tzd; > + struct __thermal_zone *tz; > + > + tzd = thermal_zone_get_zone_by_name(zone->name); > + if (IS_ERR(tzd)) > + return ERR_PTR(-EPROBE_DEFER); > + > + tz = tzd->devdata; > + > + mutex_lock(&tzd->lock); > + tz->get_temp = get_temp; > + tz->get_trend = get_trend; > + tz->sensor_data = data; > + > + tzd->ops->get_temp = of_thermal_get_temp; > + tzd->ops->get_trend = of_thermal_get_trend; > + mutex_unlock(&tzd->lock); > + > + return tzd; > +} > + > +/** > + * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone > + * @dev: a valid struct device pointer of a sensor device. Must contain > + * a valid .of_node, for the sensor node. > + * @sensor_id: a sensor identifier, in case the sensor IP has more > + * than one sensors > + * @data: a private pointer (owned by the caller) that will be passed > + * back, when a temperature reading is needed. > + * @get_temp: a pointer to a function that reads the sensor temperature. > + * @get_trend: a pointer to a function that reads the sensor temperature trend. > + * > + * This function will search the list of thermal zones described in device > + * tree and look for the zone that refer to the sensor device pointed by > + * @dev->of_node as temperature providers. For the zone pointing to the > + * sensor node, the sensor will be added to the DT thermal zone device. > + * > + * The thermal zone temperature is provided by the @get_temp function > + * pointer. When called, it will have the private pointer @data back. > + * > + * The thermal zone temperature trend is provided by the @get_trend function > + * pointer. When called, it will have the private pointer @data back. > + * > + * TODO: > + * 01 - This function must enqueue the new sensor instead of using > + * it as the only source of temperature values. > + * > + * 02 - There must be a way to match the sensor with all thermal zones > + * that refer to it. > + * > + * Return: On success returns a valid struct thermal_zone_device, > + * otherwise, it returns a corresponding ERR_PTR(). Caller must > + * check the return value with help of IS_ERR() helper. > + */ > +struct thermal_zone_device * > +thermal_zone_of_sensor_register(struct device *dev, int sensor_id, > + void *data, int (*get_temp)(void *, long *), > + int (*get_trend)(void *, long *)) > +{ > + struct device_node *np, *child, *sensor_np; > + > + np = of_find_node_by_name(NULL, "thermal-zones"); > + if (!np) > + return ERR_PTR(-ENODEV); > + > + if (!dev || !dev->of_node) > + return ERR_PTR(-EINVAL); > + > + sensor_np = dev->of_node; > + > + for_each_child_of_node(np, child) { > + struct of_phandle_args sensor_specs; > + int ret, id; > + > + /* For now, thermal framework supports only 1 sensor per zone */ > + ret = of_parse_phandle_with_args(child, "thermal-sensors", > + "#thermal-sensor-cells", > + 0, &sensor_specs); > + if (ret) > + continue; > + > + if (sensor_specs.args_count >= 1) { > + id = sensor_specs.args[0]; > + WARN(sensor_specs.args_count > 1, > + "%s: too many cells in sensor specifier %d\n", > + sensor_specs.np->name, sensor_specs.args_count); > + } else { > + id = 0; > + } > + > + if (sensor_specs.np == sensor_np && id == sensor_id) { > + of_node_put(np); > + return thermal_zone_of_add_sensor(child, sensor_np, > + data, > + get_temp, > + get_trend); > + } > + } > + of_node_put(np); > + > + return ERR_PTR(-ENODEV); > +} > +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register); > + > +/** > + * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone > + * @dev: a valid struct device pointer of a sensor device. Must contain > + * a valid .of_node, for the sensor node. > + * @tzd: a pointer to struct thermal_zone_device where the sensor is registered. > + * > + * This function removes the sensor callbacks and private data from the > + * thermal zone device registered with thermal_zone_of_sensor_register() > + * API. It will also silent the zone by remove the .get_temp() and .get_trend() > + * thermal zone device callbacks. > + * > + * TODO: When the support to several sensors per zone is added, this > + * function must search the sensor list based on @dev parameter. > + * > + */ > +void thermal_zone_of_sensor_unregister(struct device *dev, > + struct thermal_zone_device *tzd) > +{ > + struct __thermal_zone *tz; > + > + if (!dev || !tzd || !tzd->devdata) > + return; > + > + tz = tzd->devdata; > + > + /* no __thermal_zone, nothing to be done */ > + if (!tz) > + return; > + > + mutex_lock(&tzd->lock); > + tzd->ops->get_temp = NULL; > + tzd->ops->get_trend = NULL; > + > + tz->get_temp = NULL; > + tz->get_trend = NULL; > + tz->sensor_data = NULL; > + mutex_unlock(&tzd->lock); > +} > +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister); > + > +/*** functions parsing device tree nodes ***/ > + > +/** > + * thermal_of_populate_bind_params - parse and fill cooling map data > + * @np: DT node containing a cooling-map node > + * @__tbp: data structure to be filled with cooling map info > + * @trips: array of thermal zone trip points > + * @ntrips: number of trip points inside trips. > + * > + * This function parses a cooling-map type of node represented by > + * @np parameter and fills the read data into @__tbp data structure. > + * It needs the already parsed array of trip points of the thermal zone > + * in consideration. > + * > + * Return: 0 on success, proper error code otherwise > + */ > +static int thermal_of_populate_bind_params(struct device_node *np, > + struct __thermal_bind_params *__tbp, > + struct __thermal_trip *trips, > + int ntrips) > +{ > + struct of_phandle_args cooling_spec; > + struct device_node *trip; > + int ret, i; > + u32 prop; > + > + /* Default weight. Usage is optional */ > + __tbp->usage = 0; > + ret = of_property_read_u32(np, "contribution", &prop); > + if (ret == 0) > + __tbp->usage = prop; > + > + trip = of_parse_phandle(np, "trip", 0); > + if (!trip) { > + pr_err("missing trip property\n"); > + return -ENODEV; > + } > + > + /* match using device_node */ > + for (i = 0; i < ntrips; i++) > + if (trip == trips[i].np) { > + __tbp->trip_id = i; > + break; > + } > + > + if (i == ntrips) { > + ret = -ENODEV; > + goto end; > + } > + > + ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells", > + 0, &cooling_spec); > + if (ret < 0) { > + pr_err("missing cooling_device property\n"); > + goto end; > + } > + __tbp->cooling_device = cooling_spec.np; > + if (cooling_spec.args_count >= 2) { /* at least min and max */ > + __tbp->min = cooling_spec.args[0]; > + __tbp->max = cooling_spec.args[1]; > + } else { > + pr_err("wrong reference to cooling device, missing limits\n"); > + } > + > +end: > + of_node_put(trip); > + > + return ret; > +} > + > +/** > + * It maps 'enum thermal_trip_type' found in include/linux/thermal.h > + * into the device tree binding of 'trip', property type. > + */ > +static const char * const trip_types[] = { > + [THERMAL_TRIP_ACTIVE] = "active", > + [THERMAL_TRIP_PASSIVE] = "passive", > + [THERMAL_TRIP_HOT] = "hot", > + [THERMAL_TRIP_CRITICAL] = "critical", > +}; > + > +/** > + * thermal_of_get_trip_type - Get phy mode for given device_node > + * @np: Pointer to the given device_node > + * @type: Pointer to resulting trip type > + * > + * The function gets trip type string from property 'type', > + * and store its index in trip_types table in @type, > + * > + * Return: 0 on success, or errno in error case. > + */ > +static int thermal_of_get_trip_type(struct device_node *np, > + enum thermal_trip_type *type) > +{ > + const char *t; > + int err, i; > + > + err = of_property_read_string(np, "type", &t); > + if (err < 0) > + return err; > + > + for (i = 0; i < ARRAY_SIZE(trip_types); i++) > + if (!strcasecmp(t, trip_types[i])) { > + *type = i; > + return 0; > + } > + > + return -ENODEV; > +} > + > +/** > + * thermal_of_populate_trip - parse and fill one trip point data > + * @np: DT node containing a trip point node > + * @trip: trip point data structure to be filled up > + * > + * This function parses a trip point type of node represented by > + * @np parameter and fills the read data into @trip data structure. > + * > + * Return: 0 on success, proper error code otherwise > + */ > +static int thermal_of_populate_trip(struct device_node *np, > + struct __thermal_trip *trip) > +{ > + int prop; > + int ret; > + > + ret = of_property_read_u32(np, "temperature", &prop); > + if (ret < 0) { > + pr_err("missing temperature property\n"); > + return ret; > + } > + trip->temperature = prop; > + > + ret = of_property_read_u32(np, "hysteresis", &prop); > + if (ret < 0) { > + pr_err("missing hysteresis property\n"); > + return ret; > + } > + trip->hysteresis = prop; > + > + ret = thermal_of_get_trip_type(np, &trip->type); > + if (ret < 0) { > + pr_err("wrong trip type property\n"); > + return ret; > + } > + > + /* Required for cooling map matching */ > + trip->np = np; > + > + return 0; > +} > + > +/** > + * thermal_of_build_thermal_zone - parse and fill one thermal zone data > + * @np: DT node containing a thermal zone node > + * > + * This function parses a thermal zone type of node represented by > + * @np parameter and fills the read data into a __thermal_zone data structure > + * and return this pointer. > + * > + * TODO: Missing properties to parse: thermal-sensor-names and coefficients > + * > + * Return: On success returns a valid struct __thermal_zone, > + * otherwise, it returns a corresponding ERR_PTR(). Caller must > + * check the return value with help of IS_ERR() helper. > + */ > +static struct __thermal_zone * > +thermal_of_build_thermal_zone(struct device_node *np) > +{ > + struct device_node *child = NULL, *gchild; > + struct __thermal_zone *tz; > + int ret, i; > + u32 prop; > + > + if (!np) { > + pr_err("no thermal zone np\n"); > + return ERR_PTR(-EINVAL); > + } > + > + tz = kzalloc(sizeof(*tz), GFP_KERNEL); > + if (!tz) > + return ERR_PTR(-ENOMEM); > + > + ret = of_property_read_u32(np, "polling-delay-passive", &prop); > + if (ret < 0) { > + pr_err("missing polling-delay-passive property\n"); > + goto free_tz; > + } > + tz->passive_delay = prop; > + > + ret = of_property_read_u32(np, "polling-delay", &prop); > + if (ret < 0) { > + pr_err("missing polling-delay property\n"); > + goto free_tz; > + } > + tz->polling_delay = prop; > + > + /* trips */ > + child = of_get_child_by_name(np, "trips"); > + > + /* No trips provided */ > + if (!child) > + goto finish; > + > + tz->ntrips = of_get_child_count(child); > + if (tz->ntrips == 0) /* must have at least one child */ > + goto finish; > + > + tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL); > + if (!tz->trips) { > + ret = -ENOMEM; > + goto free_tz; > + } > + > + i = 0; > + for_each_child_of_node(child, gchild) { > + ret = thermal_of_populate_trip(gchild, &tz->trips[i++]); > + if (ret) > + goto free_trips; > + } > + > + of_node_put(child); > + > + /* cooling-maps */ > + child = of_get_child_by_name(np, "cooling-maps"); > + > + /* cooling-maps not provided */ > + if (!child) > + goto finish; > + > + tz->num_tbps = of_get_child_count(child); > + if (tz->num_tbps == 0) > + goto finish; > + > + tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL); > + if (!tz->tbps) { > + ret = -ENOMEM; > + goto free_trips; > + } > + > + i = 0; > + for_each_child_of_node(child, gchild) > + ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++], > + tz->trips, tz->ntrips); > + if (ret) > + goto free_tbps; > + > +finish: > + of_node_put(child); > + tz->mode = THERMAL_DEVICE_DISABLED; > + > + return tz; > + > +free_tbps: > + kfree(tz->tbps); > +free_trips: > + kfree(tz->trips); > +free_tz: > + kfree(tz); > + of_node_put(child); > + > + return ERR_PTR(ret); > +} > + > +static inline void of_thermal_free_zone(struct __thermal_zone *tz) > +{ > + kfree(tz->tbps); > + kfree(tz->trips); > + kfree(tz); > +} > + > +/** > + * of_parse_thermal_zones - parse device tree thermal data > + * > + * Initialization function that can be called by machine initialization > + * code to parse thermal data and populate the thermal framework > + * with hardware thermal zones info. This function only parses thermal zones. > + * Cooling devices and sensor devices nodes are supposed to be parsed > + * by their respective drivers. > + * > + * Return: 0 on success, proper error code otherwise > + * > + */ > +int __init of_parse_thermal_zones(void) > +{ > + struct device_node *np, *child; > + struct __thermal_zone *tz; > + struct thermal_zone_device_ops *ops; > + > + np = of_find_node_by_name(NULL, "thermal-zones"); > + if (!np) { > + pr_debug("unable to find thermal zones\n"); > + return 0; /* Run successfully on systems without thermal DT */ > + } > + > + for_each_child_of_node(np, child) { > + struct thermal_zone_device *zone; > + struct thermal_zone_params *tzp; > + > + tz = thermal_of_build_thermal_zone(child); > + if (IS_ERR(tz)) { > + pr_err("failed to build thermal zone %s: %ld\n", > + child->name, > + PTR_ERR(tz)); > + continue; > + } > + > + ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL); > + if (!ops) > + goto exit_free; > + > + tzp = kzalloc(sizeof(*tzp), GFP_KERNEL); > + if (!tzp) { > + kfree(ops); > + goto exit_free; > + } > + > + /* No hwmon because there might be hwmon drivers registering */ > + tzp->no_hwmon = true; > + > + zone = thermal_zone_device_register(child->name, tz->ntrips, > + 0, tz, > + ops, tzp, > + tz->passive_delay, > + tz->polling_delay); > + if (IS_ERR(zone)) { > + pr_err("Failed to build %s zone %ld\n", child->name, > + PTR_ERR(zone)); > + kfree(tzp); > + kfree(ops); > + of_thermal_free_zone(tz); > + /* attempting to build remaining zones still */ > + } > + } > + > + return 0; > + > +exit_free: > + of_thermal_free_zone(tz); > + > + /* no memory available, so free what we have built */ > + of_thermal_destroy_zones(); > + > + return -ENOMEM; > +} > + > +/** > + * of_thermal_destroy_zones - remove all zones parsed and allocated resources > + * > + * Finds all zones parsed and added to the thermal framework and remove them > + * from the system, together with their resources. > + * > + */ > +void __exit of_thermal_destroy_zones(void) > +{ > + struct device_node *np, *child; > + > + np = of_find_node_by_name(NULL, "thermal-zones"); > + if (!np) { > + pr_err("unable to find thermal zones\n"); > + return; > + } > + > + for_each_child_of_node(np, child) { > + struct thermal_zone_device *zone; > + > + zone = thermal_zone_get_zone_by_name(child->name); > + if (IS_ERR(zone)) > + continue; > + > + thermal_zone_device_unregister(zone); > + kfree(zone->tzp); > + kfree(zone->ops); > + of_thermal_free_zone(zone->devdata); > + } > +} > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index f7a9f4f..fec3351 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz) > */ > struct thermal_zone_device *thermal_zone_device_register(const char *type, > int trips, int mask, void *devdata, > - const struct thermal_zone_device_ops *ops, > + struct thermal_zone_device_ops *ops, > const struct thermal_zone_params *tzp, > int passive_delay, int polling_delay) > { > @@ -1751,8 +1751,14 @@ static int __init thermal_init(void) > if (result) > goto unregister_class; > > + result = of_parse_thermal_zones(); > + if (result) > + goto exit_netlink; > + > return 0; > > +exit_netlink: > + genetlink_exit(); > unregister_governors: > thermal_unregister_governors(); > unregister_class: > @@ -1768,6 +1774,7 @@ error: > > static void __exit thermal_exit(void) > { > + of_thermal_destroy_zones(); > genetlink_exit(); > class_unregister(&thermal_class); > thermal_unregister_governors(); > diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h > index 7cf2f66..3db339f 100644 > --- a/drivers/thermal/thermal_core.h > +++ b/drivers/thermal/thermal_core.h > @@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; } > static inline void thermal_gov_user_space_unregister(void) {} > #endif /* CONFIG_THERMAL_GOV_USER_SPACE */ > > +/* device tree support */ > +#ifdef CONFIG_THERMAL_OF > +int of_parse_thermal_zones(void); > +void of_thermal_destroy_zones(void); > +#else > +static inline int of_parse_thermal_zones(void) { return 0; } > +static inline void of_thermal_destroy_zones(void) { } > +#endif > + > #endif /* __THERMAL_CORE_H__ */ > diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h > new file mode 100644 > index 0000000..59c4581 > --- /dev/null > +++ b/include/dt-bindings/thermal/thermal.h > @@ -0,0 +1,27 @@ > +/* > + * This header provides constants for most thermal bindings. > + * > + * Copyright (C) 2013 Texas Instruments > + * Eduardo Valentin > + * > + * GPLv2 only > + */ > + > +#ifndef _DT_BINDINGS_THERMAL_THERMAL_H > +#define _DT_BINDINGS_THERMAL_THERMAL_H > + > +/* > + * Here are the thermal trip types. This must > + * match with enum thermal_trip_type at > + * include/linux/thermal.h > + */ > +#define THERMAL_TRIP_ACTIVE "active" > +#define THERMAL_TRIP_PASSIVE "passive" > +#define THERMAL_TRIP_HOT "hot" > +#define THERMAL_TRIP_CRITICAL "critical" I don't like this. If someone wants to include this in a C file they can't do so at the same time as include/linux/thermal.h. The defined names are longer than the actual string values, and the comment makes it sound like these could be modified rather than being a fixed ABI. I do not see the point of these constants. Thanks, Mark. > + > +/* On cooling devices upper and lower limits */ > +#define THERMAL_NO_LIMIT (-1UL) > + > +#endif > + > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > index b268d3c..b780c5b 100644 > --- a/include/linux/thermal.h > +++ b/include/linux/thermal.h > @@ -143,6 +143,7 @@ struct thermal_cooling_device { > int id; > char type[THERMAL_NAME_LENGTH]; > struct device device; > + struct device_node *np; > void *devdata; > const struct thermal_cooling_device_ops *ops; > bool updated; /* true if the cooling device does not need update */ > @@ -172,7 +173,7 @@ struct thermal_zone_device { > int emul_temperature; > int passive; > unsigned int forced_passive; > - const struct thermal_zone_device_ops *ops; > + struct thermal_zone_device_ops *ops; > const struct thermal_zone_params *tzp; > struct thermal_governor *governor; > struct list_head thermal_instances; > @@ -242,8 +243,31 @@ struct thermal_genl_event { > }; > > /* Function declarations */ > +#ifdef CONFIG_THERMAL_OF > +struct thermal_zone_device * > +thermal_zone_of_sensor_register(struct device *dev, int id, > + void *data, int (*get_temp)(void *, long *), > + int (*get_trend)(void *, long *)); > +void thermal_zone_of_sensor_unregister(struct device *dev, > + struct thermal_zone_device *tz); > +#else > +static inline struct thermal_zone_device * > +thermal_zone_of_sensor_register(struct device *dev, int id, > + void *data, int (*get_temp)(void *, long *), > + int (*get_trend)(void *, long *)) > +{ > + return NULL; > +} > + > +static inline > +void thermal_zone_of_sensor_unregister(struct device *dev, > + struct thermal_zone_device *tz) > +{ > +} > + > +#endif > struct thermal_zone_device *thermal_zone_device_register(const char *, int, int, > - void *, const struct thermal_zone_device_ops *, > + void *, struct thermal_zone_device_ops *, > const struct thermal_zone_params *, int, int); > void thermal_zone_device_unregister(struct thermal_zone_device *); > > -- > 1.8.2.1.342.gfa7285d > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/