MTP DT Bindings (draft)

apple,dockchannel-hid.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/input/apple,dockchannel-hid.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Apple DockChannel HID Transport

maintainers:
  - Michael Reeves <[email protected]>

description: |
  Transport layer for HID devices (keyboard, trackpad) connected via the
  DockChannel FIFO interface on Apple Silicon SoCs.

properties:
  compatible:
    const: apple,dockchannel-hid

  reg:
    items:
      - description: Configuration registers
      - description: Data FIFO registers
      - description: Remote configuration registers
      - description: Remote data FIFO registers

  reg-names:
    items:
      - const: config
      - const: data
      - const: rmt-config
      - const: rmt-data

  interrupts:
    items:
      - description: TX interrupt
      - description: RX interrupt

  interrupt-names:
    items:
      - const: tx
      - const: rx

  mboxes:
    maxItems: 1

  iommus:
    maxItems: 1

  apple,mtp:
    $ref: /schemas/types.yaml#/definitions/phandle
    description: Phandle to the co-processor (MTP) node.

  keyboard:
    type: object
    description: |
      Optional properties for the internal keyboard.
    properties:
      hid-country-code:
        $ref: /schemas/types.yaml#/definitions/uint32
        description: The USB HID country code for the keyboard layout.
    additionalProperties: false

required:
  - compatible
  - reg
  - reg-names
  - interrupts
  - interrupt-names
  - mboxes
  - iommus
  - apple,mtp

additionalProperties: false

examples:
  - |
    #include <dt-bindings/interrupt-controller/irq.h>
    input@8000 {
        compatible = "apple,dockchannel-hid";
        reg = <0x8000 0x4000>, <0xc000 0x4000>,
              <0x0000 0x4000>, <0x4000 0x4000>;
        reg-names = "config", "data", "rmt-config", "rmt-data";
        mboxes = <&mtp_mbox>;
        iommus = <&mtp_dart 1>;
        apple,mtp = <&mtp>;
        interrupts = <2 IRQ_TYPE_LEVEL_HIGH>, <3 IRQ_TYPE_LEVEL_HIGH>;
        interrupt-names = "tx", "rx";

        keyboard {
            hid-country-code = <0>;
        };
    };

apple,dockchannel.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (c) 2025 The Asahi Linux contributors
%YAML 1.2
---
$id: http://devicetree.org/schemas/soc/apple/apple,dockchannel.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Apple DockChannel FIFO

maintainers:
  - Michael Reeves <[email protected]>

description: |
  DockChannel is a hardware FIFO and interrupt controller used on Apple SoCs
  for low-latency communication with co-processors.

properties:
  compatible:
    items:
      - enum:
          - apple,t6020-dockchannel
          - apple,t8112-dockchannel
      - const: apple,dockchannel

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  interrupt-controller: true

  "#interrupt-cells":
    const: 2

  ranges: true

  nonposted-mmio: true

  "#address-cells":
    const: 1

  "#size-cells":
    const: 1

required:
  - compatible
  - reg
  - interrupts
  - interrupt-controller
  - "#interrupt-cells"
  - ranges
  - "#address-cells"
  - "#size-cells"

additionalProperties:
  type: object

examples:
  - |
    #include <dt-bindings/interrupt-controller/apple-aic.h>
    #include <dt-bindings/interrupt-controller/irq.h>
    mtp_dockchannel: fifo@2a9b14000 {
        compatible = "apple,t6020-dockchannel", "apple,dockchannel";
        reg = <0x2 0xa9b14000 0x0 0x4000>;
        interrupt-parent = <&aic>;
        interrupts = <AIC_IRQ 677 IRQ_TYPE_LEVEL_HIGH>;
        ranges = <0 0x2 0xa9b28000 0x20000>;
        nonposted-mmio;
        #address-cells = <1>;
        #size-cells = <1>;
        interrupt-controller;
        #interrupt-cells = <2>;
    };

apple,mtp.yaml

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

title: Apple MTP Co-processor

maintainers:
  - Michael Reeves <[email protected]>

description: |
  The MTP (Multi-Touch Processor) is an ARM-based co-processor
  used for managing internal human interface devices on M2
  and later Apple Silicon laptops.

properties:
  compatible:
    items:
      - enum:
          - apple,t6020-mtp
          - apple,t8112-mtp
      - const: apple,mtp

  reg:
    items:
      - description: ASC control registers
      - description: SRAM/Shared memory region

  reg-names:
    items:
      - const: asc
      - const: sram

required:
  - compatible
  - reg
  - reg-names

additionalProperties: false

examples:
  - |
    mtp: mtp@2a9400000 {
        compatible = "apple,t6020-mtp", "apple,mtp";
        reg = <0x2 0xa9400000 0x0 0x4000>,
              <0x2 0xa9c00000 0x0 0x100000>;
        reg-names = "asc", "sram";
    };