xref: /kernel/linux/linux-6.6/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/dma/brcm,bcm2835-dma.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: BCM2835 DMA controller

maintainers:
  - Nicolas Saenz Julienne <nsaenz@kernel.org>

description:
  The BCM2835 DMA controller has 16 channels in total. Only the lower
  13 channels have an associated IRQ. Some arbitrary channels are used by the
  VideoCore firmware (1,3,6,7 in the current firmware version). The channels
  0, 2 and 3 have special functionality and should not be used by the driver.

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

properties:
  compatible:
    const: brcm,bcm2835-dma

  reg:
    maxItems: 1

  interrupts:
    description:
      Should contain the DMA interrupts associated to the DMA channels in
      ascending order.
    minItems: 1
    maxItems: 16

  interrupt-names:
    minItems: 1
    maxItems: 16

  '#dma-cells':
    description: The single cell represents the DREQ number.
    const: 1

  brcm,dma-channel-mask:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Bitmask of available DMA channels in ascending order that are
      not reserved by firmware and are available to the
      kernel. i.e. first channel corresponds to LSB.

unevaluatedProperties: false

required:
  - compatible
  - reg
  - interrupts
  - "#dma-cells"
  - brcm,dma-channel-mask

examples:
  - |
    dma-controller@7e007000 {
      compatible = "brcm,bcm2835-dma";
      reg = <0x7e007000 0xf00>;
      interrupts = <1 16>,
                   <1 17>,
                   <1 18>,
                   <1 19>,
                   <1 20>,
                   <1 21>,
                   <1 22>,
                   <1 23>,
                   <1 24>,
                   <1 25>,
                   <1 26>,
                   /* dma channel 11-14 share one irq */
                   <1 27>,
                   <1 27>,
                   <1 27>,
                   <1 27>,
                   /* unused shared irq for all channels */
                   <1 28>;
      interrupt-names = "dma0",
                        "dma1",
                        "dma2",
                        "dma3",
                        "dma4",
                        "dma5",
                        "dma6",
                        "dma7",
                        "dma8",
                        "dma9",
                        "dma10",
                        "dma11",
                        "dma12",
                        "dma13",
                        "dma14",
                        "dma-shared-all";
        #dma-cells = <1>;
        brcm,dma-channel-mask = <0x7f35>;
    };

...