Documentation/devicetree/bindings/hwmon/microchip,emc1812.yaml

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hwmon/microchip,emc1812.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Microchip EMC1812/13/14/15/33 multichannel temperature sensor

maintainers:
  - Marius Cristea <marius.cristea@microchip.com>

description: |
  The Microchip EMC1812/13/14/15/33 is a high-accuracy 2-wire multichannel
  low-voltage remote diode temperature monitor.

  The datasheet can be found here:
    https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/EMC1812-3-4-5-33-Data-Sheet-DS20005751.pdf

  EMC1812 has one external remote temperature monitoring channel
  EMC1813 has two external remote temperature monitoring channels
  EMC1814 has three external remote temperature monitoring channels and
    channels 2 and 3 support anti parallel diode
  EMC1815 has four external remote temperature monitoring channels and
    channels 1/2 and 3/4 support anti parallel diode
  EMC1833 has two external remote temperature monitoring channels and
    channels 1 and 2 support anti parallel diode

properties:
  compatible:
    enum:
      - microchip,emc1812
      - microchip,emc1813
      - microchip,emc1814
      - microchip,emc1815
      - microchip,emc1833

  reg:
    maxItems: 1

  interrupts:
    items:
      - description: alert-therm2 asserts when the ALERT limit is exceeded.
      - description: therm-addr asserts when the THERM limit is exceeded.
    minItems: 1

  interrupt-names:
    items:
      - const: alert-therm2
      - const: therm-addr
    minItems: 1

  "#address-cells":
    const: 1

  "#size-cells":
    const: 0

  microchip,enable-anti-parallel:
    description:
      Enable anti-parallel diode mode operation. EMC1814, EMC1815 and EMC1833
      support reading two external diodes in anti-parallel connection on the
      same set of pins. Disabling APD functionality to implement substrate
      diodes on devices that support APD eliminates the benefit of APD
      (two diodes on one channel).
    type: boolean

  microchip,parasitic-res-on-channel1-2:
    description:
      Indicates that the chip and the diodes/transistors are sufficiently
      far apart that a parasitic resistance is added to the wires, which can
      affect the measurements. Due to the availability of only a single
      configuration bit in hardware, channels 1 and 2 are affected together.
      If channel 2 is not available in hardware, this setting affects only
      channel 1.
    type: boolean

  microchip,parasitic-res-on-channel3-4:
    description:
      Indicates that the chip and the diodes/transistors are sufficiently
      far apart that a parasitic resistance is added to the wires, which can
      affect the measurements. Due to the availability of only a single
      configuration bit in hardware, channels 3 and 4 are affected together.
      If channel 4 is not available in hardware, this setting affects only
      channel 3.
    type: boolean

  vdd-supply: true

patternProperties:
  "^channel@[0-4]$":
    description: |
      Represents the temperature channels.
      0: Internal sensor
      1-4: External remote diodes
    type: object

    properties:
      reg:
        maxItems: 1

      label:
        description: Unique name to identify which channel this is.

    required:
      - reg

    additionalProperties: false

required:
  - compatible
  - reg
  - vdd-supply

allOf:
  # EMC1812: 1 Internal, 1 External Channels, No APD,
  # parasitic-res-on-channel1-2: for channel 1
  - if:
      properties:
        compatible:
          const: microchip,emc1812
    then:
      properties:
        microchip,enable-anti-parallel: false
        microchip,parasitic-res-on-channel3-4: false
      patternProperties:
        "^channel@[2-4]$": false

  # EMC1813: 1 Internal, 2 External Channels, No APD,
  # parasitic-res-on-channel1-2: on both channel 1 & 2
  - if:
      properties:
        compatible:
          const: microchip,emc1813
    then:
      properties:
        microchip,enable-anti-parallel: false
        microchip,parasitic-res-on-channel3-4: false
      patternProperties:
        "^channel@[3-4]$": false

  # EMC1833: 1 Internal, 2 External Channels, Supports APD,
  # parasitic-res-on-channel1-2: on both channel 1 & 2
  - if:
      properties:
        compatible:
          const: microchip,emc1833
    then:
      properties:
        microchip,parasitic-res-on-channel3-4: false
      patternProperties:
        "^channel@[3-4]$": false

  # EMC1814: 1 Internal, 3 External Channels, Supports APD,
  # parasitic-res-on-channel1-2: on both channel 1 & 2
  # parasitic-res-on-channel3-4: for channel 3
  - if:
      properties:
        compatible:
          const: microchip,emc1814
    then:
      properties:
        channel@4: false

unevaluatedProperties: false

examples:
  - |
    i2c {
        #address-cells = <1>;
        #size-cells = <0>;

        temperature-sensor@4c {
            compatible = "microchip,emc1813";
            reg = <0x4c>;

            #address-cells = <1>;
            #size-cells = <0>;

            microchip,parasitic-res-on-channel1-2;

            vdd-supply = <&vdd>;

            channel@1 {
                reg = <1>;
                label = "External CH1 Temperature";
            };

            channel@2 {
                reg = <2>;
                label = "External CH2 Temperature";
            };
        };
    };