dt-bindings: bus: Add Baikal-T1 AXI-bus binding

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

# Copyright (C) 2020 BAIKAL ELECTRONICS, JSC

%YAML 1.2

---

$id: http://devicetree.org/schemas/bus/baikal,bt1-axi.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Baikal-T1 AXI-bus

maintainers:

  - Serge Semin <fancer.lancer@gmail.com>

description: |

  AXI3-bus is the main communication bus of Baikal-T1 SoC connecting all

  high-speed peripheral IP-cores with RAM controller and with MIPS P5600

  cores. Traffic arbitration is done by means of DW AXI Interconnect (so

  called AXI Main Interconnect) routing IO requests from one block to

  another: from CPU to SoC peripherals and between some SoC peripherals

  (mostly between peripheral devices and RAM, but also between DMA and

  some peripherals). In case of any protocol error, device not responding

  an IRQ is raised and a faulty situation is reported to the AXI EHB

  (Errors Handler Block) embedded on top of the DW AXI Interconnect and

  accessible by means of the Baikal-T1 System Controller.

allOf:

 - $ref: /schemas/simple-bus.yaml#

properties:

  compatible:

    contains:

      const: baikal,bt1-axi

  reg:

    minItems: 1

    items:

      - description: Synopsys DesignWare AXI Interconnect QoS registers

      - description: AXI EHB MMIO system controller registers

  reg-names:

    minItems: 1

    items:

      - const: qos

      - const: ehb

  '#interconnect-cells':

    const: 1

  syscon:

    $ref: /schemas/types.yaml#definitions/phandle

    description: Phandle to the Baikal-T1 System Controller DT node

  interrupts:

    maxItems: 1

  clocks:

    items:

      - description: Main Interconnect uplink reference clock

  clock-names:

    items:

      - const: aclk

  resets:

    items:

      - description: Main Interconnect reset line

  reset-names:

    items:

      - const: arst

unevaluatedProperties: false

required:

  - compatible

  - reg

  - reg-names

  - syscon

  - interrupts

  - clocks

  - clock-names

examples:

  - |

    #include <dt-bindings/interrupt-controller/mips-gic.h>

    bus@1f05a000 {

      compatible = "baikal,bt1-axi", "simple-bus";

      reg = <0 0x1f05a000 0 0x1000>,

            <0 0x1f04d110 0 0x8>;

      reg-names = "qos", "ehb";

      #address-cells = <1>;

      #size-cells = <1>;

      #interconnect-cells = <1>;

      syscon = <&syscon>;

      ranges;

      interrupts = <GIC_SHARED 127 IRQ_TYPE_LEVEL_HIGH>;

      clocks = <&ccu_axi 0>;

      clock-names = "aclk";

      resets = <&ccu_axi 0>;

      reset-names = "arst";

    };

...