xref: /openbmc/linux/Documentation/devicetree/bindings/net/mctp-i2c-controller.yaml (revision 84e85359)

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/net/mctp-i2c-controller.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: MCTP I2C transport

maintainers:
  - Matt Johnston <matt@codeconstruct.com.au>

description: |
  An mctp-i2c-controller defines a local MCTP endpoint on an I2C controller.
  MCTP I2C is specified by DMTF DSP0237.

  An mctp-i2c-controller must be attached to an I2C adapter which supports
  slave functionality. I2C busses (either directly or as subordinate mux
  busses) are attached to the mctp-i2c-controller with a 'mctp-controller'
  property on each used bus. Each mctp-controller I2C bus will be presented
  to the host system as a separate MCTP I2C instance.

properties:
  compatible:
    const: mctp-i2c-controller

  reg:
    minimum: 0x40000000
    maximum: 0x4000007f
    description: |
      7 bit I2C address of the local endpoint.
      I2C_OWN_SLAVE_ADDRESS (1<<30) flag must be set.

additionalProperties: false

required:
  - compatible
  - reg

examples:
  - |
    // Basic case of a single I2C bus
    #include <dt-bindings/i2c/i2c.h>

    i2c {
      #address-cells = <1>;
      #size-cells = <0>;
      mctp-controller;

      mctp@30 {
        compatible = "mctp-i2c-controller";
        reg = <(0x30 | I2C_OWN_SLAVE_ADDRESS)>;
      };
    };

  - |
    // Mux topology with multiple MCTP-handling busses under
    // a single mctp-i2c-controller.
    // i2c1 and i2c6 can have MCTP devices, i2c5 does not.
    #include <dt-bindings/i2c/i2c.h>

    i2c1: i2c {
      #address-cells = <1>;
      #size-cells = <0>;
      mctp-controller;

      mctp@50 {
        compatible = "mctp-i2c-controller";
        reg = <(0x50 | I2C_OWN_SLAVE_ADDRESS)>;
      };
    };

    i2c-mux {
      #address-cells = <1>;
      #size-cells = <0>;
      i2c-parent = <&i2c1>;

      i2c5: i2c@0 {
        #address-cells = <1>;
        #size-cells = <0>;
        reg = <0>;
        eeprom@33 {
          reg = <0x33>;
        };
      };

      i2c6: i2c@1 {
        #address-cells = <1>;
        #size-cells = <0>;
        reg = <1>;
        mctp-controller;
      };
    };