On Thu, Mar 05, 2020 at 06:26:43PM +0530, Amit Kucheria wrote: > As part of moving the thermal bindings to YAML, split it up into 3 > bindings: thermal sensors, cooling devices and thermal zones. > > The thermal-zone binding is a software abstraction to capture the > properties of each zone - how often they should be checked, the > temperature thresholds (trips) at which mitigation actions need to be > taken and the level of mitigation needed at those thresholds. > > Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx> > --- > .../bindings/thermal/thermal-zones.yaml | 325 ++++++++++++++++++ > 1 file changed, 325 insertions(+) > create mode 100644 Documentation/devicetree/bindings/thermal/thermal-zones.yaml > > diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml > new file mode 100644 > index 0000000000000..f8f3b72bc3119 > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml > @@ -0,0 +1,325 @@ > +# SPDX-License-Identifier: (GPL-2.0) > +# Copyright 2020 Linaro Ltd. > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/thermal/thermal-zones.yaml# > +$schema: http://devicetree.org/meta-schemas/base.yaml# > + > +title: Thermal zone binding > + > +maintainers: > + - Amit Kucheria <amitk@xxxxxxxxxx> > + > +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 overloads. > + > + 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 actively > + - thermal-zones: a container of the following node types used to describe all > + thermal data for the platform > + > + This binding describes the thermal-zones. > + > + The polling-delay properties of a thermal-zone are bound to the maximum dT/dt > + (temperature derivative over time) in two situations for a thermal zone: > + 1. when passive cooling is activated (polling-delay-passive) > + 2. 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. > + > +properties: > + thermal-zones: > + type: object > + description: > + A /thermal-zones node is required in order to use the thermal framework to > + manage input from the various thermal zones in the system in order to > + mitigate thermal overload conditions. It does not represent a real device > + in the system, but acts as a container to link thermal sensor devices, > + platform-data regarding temperature thresholds and the mitigation actions > + to take when the temperature crosses those thresholds. > + > + properties: > + $nodename: > + pattern: "^[a-zA-Z][a-zA-Z0-9,\\-]{1,12}-thermal$" These 3 lines should be: patternProperties: "^[a-zA-Z][a-zA-Z0-9,\\-]{1,12}-thermal$": Though we should drop ',' as well. $nodename is only needed at the top level where it's kind of special. > + type: object > + description: > + Each thermal zone node contains information about how frequently it > + must be checked, the sensor responsible for reporting temperature for > + this zone, one sub-node containing the various trip points for this > + zone and one sub-node containing all the zone cooling-maps. > + > + properties: > + polling-delay: > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 0 The type is unsigned, so the min is already 0. > + description: > + The maximum number of milliseconds to wait between polls when > + checking this thermal zone. Setting this to 0 disables the polling > + timers setup by the thermal framework and assumes that the thermal > + sensors in this zone support interrupts. > + > + polling-delay-passive: > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 0 > + description: > + The maximum number of milliseconds to wait between polls when > + checking this thermal zone while doing passive cooling. Setting > + this to 0 disables the polling timers setup by the thermal > + framework and assumes that the thermal sensors in this zone > + support interrupts. > + > + thermal-sensors: > + $ref: /schemas/types.yaml#/definitions/phandle-array > + description: > + A list of thermal sensor phandles and sensor specifiers used to > + monitor this thermal zone. > + > + trips: > + type: object > + description: > + This node describes a set of points in the temperature domain at > + which the thermal framework needs to takes action. The actions to > + be taken are defined in another node called cooling-maps. > + > + patternProperties: > + "^[a-zA-Z][a-zA-Z0-9,+\\._]{0,63}$": Drop ',', '+', '.', and ideally '_'. Probably need to add '-'. > + type: object > + > + properties: > + temperature: > + $ref: /schemas/types.yaml#/definitions/int32 > + minimum: -273000 > + maximum: 200000 > + description: > + An integer expressing the trip temperature in millicelsius. > + > + hysteresis: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: > + An unsigned integer expressing the hysteresis delta with > + respect to the trip temperature property above, also in > + millicelsius. > + > + type: Needs a type reference (string). > + enum: > + # active: enable active cooling e.g. fans > + - active Wrong indentation. Should be 2 less. Also, I think this would be more readable: - active # enable active cooling e.g. fans > + # passive: enable passive cooling e.g. throttling cpu > + - passive > + # hot: send notification to driver if .notify > + # callback registered > + - hot > + # critical: send notification to driver if .notify > + # callback registered and trigger a shutdown > + - critical > + description: | > + There are four valid trip types: active, passive, hot, > + critical. > + > + The critical trip type is used to set the maximum > + temperature threshold above which the HW becomes > + unstable and underlying firmware might even trigger a > + reboot. Hitting the critical threshold triggers a system > + shutdown. > + > + The hot trip type can be used to send a notification to > + the thermal driver (if a .notify callback is registered). > + The action to be taken is left to the driver. > + > + The passive trip type can be used to slow down HW e.g. run > + the CPU, GPU, bus at a lower frequency. > + > + The active trip type can be used to control other HW to > + help in cooling e.g. fans can be sped up or slowed down > + > + required: > + - temperature > + - hysteresis > + - type > + > + additionalProperties: false You need 'additionalProperties' on the child nodes too, or are there vendor specific properties allowed? > + > + cooling-maps: > + type: object > + description: > + This node describes the action to be taken when a thermal zone > + crosses one of the temperature thresholds described in the trips > + node. The action takes the form of a mapping relation between a > + trip and the target cooling device state. > + > + patternProperties: > + "^map[0-9][-a-zA-Z0-9]*$": > + type: object > + > + properties: > + trip: > + $ref: /schemas/types.yaml#/definitions/phandle > + description: > + A phandle of a trip point node within this thermal zone. > + > + cooling-device: > + $ref: /schemas/types.yaml#/definitions/phandle-array > + description: > + A list of cooling device phandles along with the minimum > + and maximum cooling state specifiers for each cooling > + device. Using the THERMAL_NO_LIMIT (-1UL) constant in the > + cooling-device phandle limit specifier lets the framework > + use the minimum and maximum cooling state for that cooling > + device automatically. > + > + contribution: > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 0 > + maximum: 100 > + description: > + The contribution of the cooling devices at the trip > + temperature, both referenced in this map, to this thermal > + zone as a percentage. > + > + required: > + - trip > + - cooling-device > + 'additionalProperties' for map* nodes? > + additionalProperties: false > + > +examples: > + - | > + #include <dt-bindings/interrupt-controller/arm-gic.h> > + #include <dt-bindings/thermal/thermal.h> > + > + // Example 1: SDM845 TSENS > + soc: soc@0 { > + #address-cells = <2>; > + #size-cells = <2>; > + > + /* ... */ > + > + tsens0: thermal-sensor@c263000 { > + compatible = "qcom,sdm845-tsens", "qcom,tsens-v2"; > + reg = <0 0x0c263000 0 0x1ff>, /* TM */ > + <0 0x0c222000 0 0x1ff>; /* SROT */ > + #qcom,sensors = <13>; > + interrupts = <GIC_SPI 506 IRQ_TYPE_LEVEL_HIGH>, > + <GIC_SPI 508 IRQ_TYPE_LEVEL_HIGH>; > + interrupt-names = "uplow", "critical"; > + #thermal-sensor-cells = <1>; > + }; > + > + tsens1: thermal-sensor@c265000 { > + compatible = "qcom,sdm845-tsens", "qcom,tsens-v2"; > + reg = <0 0x0c265000 0 0x1ff>, /* TM */ > + <0 0x0c223000 0 0x1ff>; /* SROT */ > + #qcom,sensors = <8>; > + interrupts = <GIC_SPI 507 IRQ_TYPE_LEVEL_HIGH>, > + <GIC_SPI 509 IRQ_TYPE_LEVEL_HIGH>; > + interrupt-names = "uplow", "critical"; > + #thermal-sensor-cells = <1>; > + }; > + }; > + > + /* ... */ > + > + 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"; > + }; > + > + cpu0_alert1: trip-point1 { > + temperature = <95000>; > + hysteresis = <2000>; > + type = "passive"; > + }; > + > + cpu0_crit: cpu_crit { > + temperature = <110000>; > + hysteresis = <1000>; > + type = "critical"; > + }; > + }; > + > + cooling-maps { > + map0 { > + trip = <&cpu0_alert0>; > + cooling-device = <&CPU0 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU1 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU2 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU3 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>; > + }; > + > + map1 { > + trip = <&cpu0_alert1>; > + cooling-device = <&CPU0 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU1 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU2 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>, > + <&CPU3 THERMAL_NO_LIMIT > + THERMAL_NO_LIMIT>; > + }; > + }; > + }; > + > + /* ... */ > + > + cluster0-thermal { > + polling-delay-passive = <250>; > + polling-delay = <1000>; > + > + thermal-sensors = <&tsens0 5>; > + > + trips { > + cluster0_alert0: trip-point0 { > + temperature = <90000>; > + hysteresis = <2000>; > + type = "hot"; > + }; > + cluster0_crit: cluster0_crit { > + temperature = <110000>; > + hysteresis = <2000>; > + type = "critical"; > + }; > + }; > + }; > + > + /* ... */ > + > + gpu-thermal-top { This one is not going to match (which should cause an error). > + polling-delay-passive = <250>; > + polling-delay = <1000>; > + > + thermal-sensors = <&tsens0 11>; > + > + trips { > + gpu1_alert0: trip-point0 { > + temperature = <90000>; > + hysteresis = <2000>; > + type = "hot"; > + }; > + }; > + }; > + }; > +... > -- > 2.20.1 >
