Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.yaml

   1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 %YAML 1.2
   3 ---
   4 $id: http://devicetree.org/schemas/dma/brcm,bcm2835-dma.yaml#
   5 $schema: http://devicetree.org/meta-schemas/core.yaml#
   6
   7 title: BCM2835 DMA controller
   8
   9 maintainers:
  10   - Nicolas Saenz Julienne <nsaenz@kernel.org>
  11
  12 description:
  13   The BCM2835 DMA controller has 16 channels in total. Only the lower
  14   13 channels have an associated IRQ. Some arbitrary channels are used by the
  15   VideoCore firmware (1,3,6,7 in the current firmware version). The channels
  16   0, 2 and 3 have special functionality and should not be used by the driver.
  17
  18 allOf:
  19   - $ref: dma-controller.yaml#
  20
  21 properties:
  22   compatible:
  23     const: brcm,bcm2835-dma
  24
  25   reg:
  26     maxItems: 1
  27
  28   interrupts:
  29     description:
  30       Should contain the DMA interrupts associated to the DMA channels in
  31       ascending order.
  32     minItems: 1
  33     maxItems: 16
  34
  35   interrupt-names:
  36     minItems: 1
  37     maxItems: 16
  38
  39   '#dma-cells':
  40     description: The single cell represents the DREQ number.
  41     const: 1
  42
  43   brcm,dma-channel-mask:
  44     $ref: /schemas/types.yaml#/definitions/uint32
  45     description:
  46       Bitmask of available DMA channels in ascending order that are
  47       not reserved by firmware and are available to the
  48       kernel. i.e. first channel corresponds to LSB.
  49
  50 unevaluatedProperties: false
  51
  52 required:
  53   - compatible
  54   - reg
  55   - interrupts
  56   - "#dma-cells"
  57   - brcm,dma-channel-mask
  58
  59 examples:
  60   - |
  61     dma-controller@7e007000 {
  62       compatible = "brcm,bcm2835-dma";
  63       reg = <0x7e007000 0xf00>;
  64       interrupts = <1 16>,
  65                    <1 17>,
  66                    <1 18>,
  67                    <1 19>,
  68                    <1 20>,
  69                    <1 21>,
  70                    <1 22>,
  71                    <1 23>,
  72                    <1 24>,
  73                    <1 25>,
  74                    <1 26>,
  75                    /* dma channel 11-14 share one irq */
  76                    <1 27>,
  77                    <1 27>,
  78                    <1 27>,
  79                    <1 27>,
  80                    /* unused shared irq for all channels */
  81                    <1 28>;
  82       interrupt-names = "dma0",
  83                         "dma1",
  84                         "dma2",
  85                         "dma3",
  86                         "dma4",
  87                         "dma5",
  88                         "dma6",
  89                         "dma7",
  90                         "dma8",
  91                         "dma9",
  92                         "dma10",
  93                         "dma11",
  94                         "dma12",
  95                         "dma13",
  96                         "dma14",
  97                         "dma-shared-all";
  98         #dma-cells = <1>;
  99         brcm,dma-channel-mask = <0x7f35>;
 100     };
 101
 102 ...