Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/thermal/nvidia,tegra124-soctherm.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: NVIDIA Tegra124 SOCTHERM Thermal Management System

maintainers:
  - Thierry Reding <thierry.reding@gmail.com>
  - Jon Hunter <jonathanh@nvidia.com>

description: The SOCTHERM IP block contains thermal sensors, support for
  polled or interrupt-based thermal monitoring, CPU and GPU throttling based
  on temperature trip points, and handling external overcurrent notifications.
  It is also used to manage emergency shutdown in an overheating situation.

properties:
  compatible:
    enum:
      - nvidia,tegra124-soctherm
      - nvidia,tegra132-soctherm
      - nvidia,tegra210-soctherm

  reg:
    maxItems: 2

  reg-names:
    maxItems: 2

  interrupts:
    items:
      - description: module interrupt
      - description: EDP interrupt

  interrupt-names:
    items:
      - const: thermal
      - const: edp

  clocks:
    items:
      - description: thermal sensor clock
      - description: module clock

  clock-names:
    items:
      - const: tsensor
      - const: soctherm

  resets:
    items:
      - description: module reset

  reset-names:
    items:
      - const: soctherm

  "#thermal-sensor-cells":
    const: 1

  throttle-cfgs:
    $ref: thermal-cooling-devices.yaml
    description: A sub-node which is a container of configuration for each
      hardware throttle events. These events can be set as cooling devices.
      Throttle event sub-nodes must be named as "light" or "heavy".
    unevaluatedProperties: false
    patternProperties:
      "^(light|heavy|oc1)$":
        type: object
        additionalProperties: false

        properties:
          "#cooling-cells":
            const: 2

          nvidia,priority:
            $ref: /schemas/types.yaml#/definitions/uint32
            minimum: 1
            maximum: 100
            description: Each throttles has its own throttle settings, so the
              SW need to set priorities for various throttle, the HW arbiter
              can select the final throttle settings. Bigger value indicates
              higher priority, In general, higher priority translates to lower
              target frequency. SW needs to ensure that critical thermal
              alarms are given higher priority, and ensure that there is no
              race if priority of two vectors is set to the same value.

          nvidia,cpu-throt-percent:
            description: This property is for Tegra124 and Tegra210. It is the
              throttling depth of pulse skippers, it's the percentage
              throttling.
            minimum: 0
            maximum: 100

          nvidia,cpu-throt-level:
            $ref: /schemas/types.yaml#/definitions/uint32
            description: This property is only for Tegra132, it is the level
              of pulse skippers, which used to throttle clock frequencies. It
              indicates cpu clock throttling depth, and the depth can be
              programmed.
            enum:
              # none (TEGRA_SOCTHERM_THROT_LEVEL_NONE)
              - 0
              # low (TEGRA_SOCTHERM_THROT_LEVEL_LOW)
              - 1
              # medium (TEGRA_SOCTHERM_THROT_LEVEL_MED)
              - 2
              # high (TEGRA_SOCTHERM_THROT_LEVEL_HIGH)
              - 3

          nvidia,gpu-throt-level:
            $ref: /schemas/types.yaml#/definitions/uint32
            description: This property is for Tegra124 and Tegra210. It is the
              level of pulse skippers, which used to throttle clock
              frequencies. It indicates gpu clock throttling depth and can be
              programmed to any of the following values which represent a
              throttling percentage.
            enum:
              # none (0%, TEGRA_SOCTHERM_THROT_LEVEL_NONE)
              - 0
              # low (50%, TEGRA_SOCTHERM_THROT_LEVEL_LOW)
              - 1
              # medium (75%, TEGRA_SOCTHERM_THROT_LEVEL_MED)
              - 2
              # high (85%, TEGRA_SOCTHERM_THROT_LEVEL_HIGH)
              - 3

          # optional
          # Tegra210 specific and valid only for OCx throttle events
          nvidia,count-threshold:
            $ref: /schemas/types.yaml#/definitions/uint32
            description: Specifies the number of OC events that are required
              for triggering an interrupt. Interrupts are not triggered if the
              property is missing. A value of 0 will interrupt on every OC
              alarm.

          nvidia,polarity-active-low:
            $ref: /schemas/types.yaml#/definitions/flag
            description: Configures the polarity of the OC alaram signal. If
              present, this means assert low, otherwise assert high.

          nvidia,alarm-filter:
            $ref: /schemas/types.yaml#/definitions/uint32
            description: Number of clocks to filter event. When the filter
              expires (which means the OC event has not occurred for a long
              time), the counter is cleared and filter is rearmed.
            default: 0

          nvidia,throttle-period-us:
            description: Specifies the number of microseconds for which
              throttling is engaged after the OC event is deasserted.
            default: 0

  # optional
  nvidia,thermtrips:
    $ref: /schemas/types.yaml#/definitions/uint32-matrix
    description: |
      When present, this property specifies the temperature at which the
      SOCTHERM hardware will assert the thermal trigger signal to the Power
      Management IC, which can be configured to reset or shutdown the device.
      It is an array of pairs where each pair represents a tsensor ID followed
      by a temperature in milli Celcius. In the absence of this property the
      critical trip point will be used for thermtrip temperature.

      Note:
      - the "critical" type trip points will be used to set the temperature at
        which the SOCTHERM hardware will assert a thermal trigger if the
        "nvidia,thermtrips" property is missing.  When the thermtrips property
        is present, the breach of a critical trip point is reported back to
        the thermal framework to implement software shutdown.

      - the "hot" type trip points will be set to SOCTHERM hardware as the
        throttle temperature.  Once the temperature of this thermal zone is
        higher than it, it will trigger the HW throttle event.
    items:
      items:
        - description: sensor ID
          oneOf:
            - description: CPU sensor
              const: 0
            - description: MEM sensor
              const: 1
            - description: GPU sensor
              const: 2
            - description: PLLX sensor
              const: 3
        - description: temperature threshold (in millidegree Celsius)

required:
  - compatible
  - reg
  - reg-names
  - interrupts
  - interrupt-names
  - clocks
  - clock-names
  - resets
  - reset-names

allOf:
  - $ref: thermal-sensor.yaml
  - if:
      properties:
        compatible:
          contains:
            enum:
              - nvidia,tegra124-soctherm
              - nvidia,tegra210-soctherm
    then:
      properties:
        reg:
          items:
            - description: SOCTHERM register set
            - description: clock and reset controller registers

        reg-names:
          items:
            - const: soctherm-reg
            - const: car-reg

    else:
      properties:
        reg:
          items:
            - description: SOCTHERM register set
            - description: CCROC registers

        reg-names:
          items:
            - const: soctherm-reg
            - const: ccroc-reg

additionalProperties: false

examples:
  - |
    #include <dt-bindings/clock/tegra124-car.h>
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/thermal/tegra124-soctherm.h>

    soctherm@700e2000 {
        compatible = "nvidia,tegra124-soctherm";
        reg = <0x700e2000 0x600>, /* SOC_THERM reg_base */
              <0x60006000 0x400>; /* CAR reg_base */
        reg-names = "soctherm-reg", "car-reg";
        interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>,
                     <GIC_SPI 51 IRQ_TYPE_LEVEL_HIGH>;
        interrupt-names = "thermal", "edp";
        clocks = <&tegra_car TEGRA124_CLK_TSENSOR>,
                 <&tegra_car TEGRA124_CLK_SOC_THERM>;
        clock-names = "tsensor", "soctherm";
        resets = <&tegra_car 78>;
        reset-names = "soctherm";

        #thermal-sensor-cells = <1>;

        nvidia,thermtrips = <TEGRA124_SOCTHERM_SENSOR_CPU 102500>,
                            <TEGRA124_SOCTHERM_SENSOR_GPU 103000>;

        throttle-cfgs {
            /*
             * When the "heavy" cooling device triggered,
             * the HW will skip cpu clock's pulse in 85% depth,
             * skip gpu clock's pulse in 85% level
             */
            heavy {
                nvidia,priority = <100>;
                nvidia,cpu-throt-percent = <85>;
                nvidia,gpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_HIGH>;

                #cooling-cells = <2>;
            };

            /*
             * When the "light" cooling device triggered,
             * the HW will skip cpu clock's pulse in 50% depth,
             * skip gpu clock's pulse in 50% level
             */
            light {
                nvidia,priority = <80>;
                nvidia,cpu-throt-percent = <50>;
                nvidia,gpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_LOW>;

                #cooling-cells = <2>;
            };

            /*
             * If these two devices are triggered in same time, the HW throttle
             * arbiter will select the highest priority as the final throttle
             * settings to skip cpu pulse.
             */

            oc1 {
                nvidia,priority = <50>;
                nvidia,polarity-active-low;
                nvidia,count-threshold = <100>;
                nvidia,alarm-filter = <5100000>;
                nvidia,throttle-period-us = <0>;
                nvidia,cpu-throt-percent = <75>;
                nvidia,gpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_MED>;
            };
        };
    };

  # referring to Tegra132's "reg", "reg-names" and "throttle-cfgs"
  - |
    thermal-sensor@700e2000 {
        compatible = "nvidia,tegra132-soctherm";
        reg = <0x700e2000 0x600>, /* SOC_THERM reg_base */
              <0x70040000 0x200>; /* CCROC reg_base */
        reg-names = "soctherm-reg", "ccroc-reg";
        interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>,
                     <GIC_SPI 51 IRQ_TYPE_LEVEL_HIGH>;
        interrupt-names = "thermal", "edp";
        clocks = <&tegra_car TEGRA124_CLK_TSENSOR>,
                 <&tegra_car TEGRA124_CLK_SOC_THERM>;
        clock-names = "tsensor", "soctherm";
        resets = <&tegra_car 78>;
        reset-names = "soctherm";
        #thermal-sensor-cells = <1>;

        throttle-cfgs {
            /*
             * When the "heavy" cooling device triggered,
             * the HW will skip cpu clock's pulse in HIGH level
             */
            heavy {
                nvidia,priority = <100>;
                nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_HIGH>;

                #cooling-cells = <2>;
            };

            /*
             * When the "light" cooling device triggered,
             * the HW will skip cpu clock's pulse in MED level
             */
            light {
                nvidia,priority = <80>;
                nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_MED>;

                #cooling-cells = <2>;
            };

            /*
             * If these two devices are triggered in same time, the HW throttle
             * arbiter will select the highest priority as the final throttle
             * settings to skip cpu pulse.
             */
        };
    };

  # referring to thermal sensors
  - |
    thermal-zones {
        cpu-thermal {
            polling-delay-passive = <1000>;
            polling-delay = <1000>;

            thermal-sensors = <&soctherm TEGRA124_SOCTHERM_SENSOR_CPU>;

            trips {
                cpu_shutdown_trip: shutdown-trip {
                    temperature = <102500>;
                    hysteresis = <1000>;
                    type = "critical";
                };

                cpu_throttle_trip: throttle-trip {
                    temperature = <100000>;
                    hysteresis = <1000>;
                    type = "hot";
                };
            };

            cooling-maps {
                map0 {
                    trip = <&cpu_throttle_trip>;
                    cooling-device = <&throttle_heavy 1 1>;
                };
            };
        };
    };