xref: /openbmc/linux/Documentation/devicetree/bindings/dma/intel,ldma.yaml (revision 10cafa2d)

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

title: Lightning Mountain centralized DMA controllers.

maintainers:
  - chuanhua.lei@intel.com
  - mallikarjunax.reddy@intel.com

allOf:
  - $ref: dma-controller.yaml#

properties:
  compatible:
    enum:
      - intel,lgm-cdma
      - intel,lgm-dma2tx
      - intel,lgm-dma1rx
      - intel,lgm-dma1tx
      - intel,lgm-dma0tx
      - intel,lgm-dma3
      - intel,lgm-toe-dma30
      - intel,lgm-toe-dma31

  reg:
    maxItems: 1

  "#dma-cells":
    const: 3
    description:
      The first cell is the peripheral's DMA request line.
      The second cell is the peripheral's (port) number corresponding to the channel.
      The third cell is the burst length of the channel.

  dma-channels:
    minimum: 1
    maximum: 16

  dma-channel-mask:
    maxItems: 1

  clocks:
    maxItems: 1

  resets:
    maxItems: 1

  reset-names:
    items:
      - const: ctrl

  interrupts:
    maxItems: 1

  intel,dma-poll-cnt:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      DMA descriptor polling counter is used to control the poling mechanism
      for the descriptor fetching for all channels.

  intel,dma-byte-en:
    type: boolean
    description:
      DMA byte enable is only valid for DMA write(RX).
      Byte enable(1) means DMA write will be based on the number of dwords
      instead of the whole burst.

  intel,dma-drb:
    type: boolean
    description:
      DMA descriptor read back to make sure data and desc synchronization.

  intel,dma-dburst-wr:
    type: boolean
    description:
      Enable RX dynamic burst write. When it is enabled, the DMA does RX dynamic burst;
      if it is disabled, the DMA RX will still support programmable fixed burst size of 2,4,8,16.
      It only applies to RX DMA and memcopy DMA.

required:
  - compatible
  - reg

additionalProperties: false

examples:
  - |
    dma0: dma-controller@e0e00000 {
      compatible = "intel,lgm-cdma";
      reg = <0xe0e00000 0x1000>;
      #dma-cells = <3>;
      dma-channels = <16>;
      dma-channel-mask = <0xFFFF>;
      interrupt-parent = <&ioapic1>;
      interrupts = <82 1>;
      resets = <&rcu0 0x30 0>;
      reset-names = "ctrl";
      clocks = <&cgu0 80>;
      intel,dma-poll-cnt = <4>;
      intel,dma-byte-en;
      intel,dma-drb;
    };
  - |
    dma3: dma-controller@ec800000 {
      compatible = "intel,lgm-dma3";
      reg = <0xec800000 0x1000>;
      clocks = <&cgu0 71>;
      resets = <&rcu0 0x10 9>;
      #dma-cells = <3>;
      intel,dma-poll-cnt = <16>;
      intel,dma-byte-en;
      intel,dma-dburst-wr;
    };