Documentation/devicetree/bindings/soc/aspeed/xdma.yaml

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

title: Aspeed AST25XX and AST26XX XDMA Engine

maintainers:
 - Eddie James <eajames@linux.ibm.com>

description: |
  This binding describes the XDMA Engine embedded in the AST2500 and AST2600
  SOCs. The XDMA engine can perform automatic DMA operations over PCI between
  the SOC (acting as a BMC) and a host processor.

properties:
  compatible:
    enum:
      - aspeed,ast2500-xdma
      - aspeed,ast2600-xdma

  reg:
    maxItems: 1

  clocks:
    maxItems: 1

  resets:
    minItems: 1
    maxItems: 2

  reset-names:
    maxItems: 2
    items:
      - const: device
      - const: root-complex

  interrupts:
    maxItems: 2
    items:
      - description: global interrupt for the XDMA engine
      - description: PCI-E reset or PERST interrupt

  aspeed,scu:
    description: a reference to the System Control Unit node of the Aspeed SOC.
    allOf:
      - $ref: /schemas/types.yaml#/definitions/phandle

  aspeed,pcie-device:
    description: describes which PCI-E device the XDMA engine should use
    allOf:
      - $ref: /schemas/types.yaml#/definitions/string
      - enum: [ bmc, vga ]

required:
  - compatible
  - reg
  - clocks
  - resets
  - interrupts-extended
  - aspeed,scu
  - memory-region

if:
  properties:
    compatible:
      contains:
        const: aspeed,ast2600-xdma
then:
  required:
    - reset-names

examples:
  - |
    #include <dt-bindings/clock/ast2600-clock.h>
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/interrupt-controller/aspeed-scu-ic.h>
    syscon: syscon@1e6e2000 {
        reg = <0x1e6e2000 0x1000>;
        ranges = <0 0x1e6e2000 0x1000>;
        #address-cells = <1>;
        #size-cells = <1>;
        #clock-cells = <1>;
        #reset-cells = <1>;
        scu_ic0: interrupt-controller@560 {
            reg = <0x560 0x4>;
            interrupt-controller;
            #interrupt-cells = <1>;
        };
    };
    xdma@1e6e7000 {
        compatible = "aspeed,ast2600-xdma";
        reg = <0x1e6e7000 0x100>;
        clocks = <&syscon ASPEED_CLK_GATE_BCLK>;
        resets = <&syscon ASPEED_RESET_DEV_XDMA>, <&syscon ASPEED_RESET_RC_XDMA>;
        reset-names = "device", "root-complex";
        interrupts-extended = <&gic GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
                              <&scu_ic0 ASPEED_AST2600_SCU_IC0_PCIE_PERST_LO_TO_HI>;
        aspeed,scu = <&syscon>;
        aspeed,pcie-device = "bmc";
        memory-region = <&vga_memory>;
    };