spi-controller.yaml 3.95 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/spi/spi-controller.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: SPI Controller Generic Binding

maintainers:
  - Mark Brown <broonie@kernel.org>

description: |
  SPI busses can be described with a node for the SPI controller device
  and a set of child nodes for each SPI slave on the bus. The system SPI
  controller may be described for use in SPI master mode or in SPI slave mode,
  but not for both at the same time.

properties:
  $nodename:
    pattern: "^spi(@.*|-[0-9a-f])*$"

  "#address-cells":
    const: 1

  "#size-cells":
    const: 0

  cs-gpios:
    description: |
      GPIOs used as chip selects.
      If that property is used, the number of chip selects will be
      increased automatically with max(cs-gpios, hardware chip selects).

34
      So if, for example, the controller has 4 CS lines, and the
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
      cs-gpios looks like this
        cs-gpios = <&gpio1 0 0>, <0>, <&gpio1 1 0>, <&gpio1 2 0>;

      Then it should be configured so that num_chipselect = 4, with
      the following mapping
        cs0 : &gpio1 0 0
        cs1 : native
        cs2 : &gpio1 1 0
        cs3 : &gpio1 2 0

  num-cs:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Total number of chip selects.

  spi-slave:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The SPI controller acts as a slave, instead of a master.

patternProperties:
  "^slave$":
    type: object

    properties:
      compatible:
        description:
          Compatible of the SPI device.

    required:
      - compatible

  "^.*@[0-9a-f]+$":
    type: object

    properties:
      compatible:
        description:
          Compatible of the SPI device.

      reg:
        minimum: 0
        maximum: 256
        description:
          Chip select used by the device.

      spi-3wire:
        $ref: /schemas/types.yaml#/definitions/flag
        description:
          The device requires 3-wire mode.

      spi-cpha:
        $ref: /schemas/types.yaml#/definitions/flag
        description:
          The device requires shifted clock phase (CPHA) mode.

      spi-cpol:
        $ref: /schemas/types.yaml#/definitions/flag
        description:
          The device requires inverse clock polarity (CPOL) mode.

      spi-cs-high:
        $ref: /schemas/types.yaml#/definitions/flag
        description:
          The device requires the chip select active high.

      spi-lsb-first:
        $ref: /schemas/types.yaml#/definitions/flag
        description:
          The device requires the LSB first mode.

      spi-max-frequency:
        $ref: /schemas/types.yaml#/definitions/uint32
        description:
          Maximum SPI clocking speed of the device in Hz.

      spi-rx-bus-width:
        allOf:
          - $ref: /schemas/types.yaml#/definitions/uint32
          - enum: [ 1, 2, 4 ]
          - default: 1
        description:
          Bus width to the SPI bus used for MISO.

      spi-rx-delay-us:
        description:
          Delay, in microseconds, after a read transfer.

      spi-tx-bus-width:
        allOf:
          - $ref: /schemas/types.yaml#/definitions/uint32
          - enum: [ 1, 2, 4 ]
          - default: 1
        description:
          Bus width to the SPI bus used for MOSI.

      spi-tx-delay-us:
        description:
          Delay, in microseconds, after a write transfer.

    required:
      - compatible
      - reg

examples:
  - |
    spi@f00 {
        #address-cells = <1>;
        #size-cells = <0>;
        compatible = "fsl,mpc5200b-spi","fsl,mpc5200-spi";
        reg = <0xf00 0x20>;
        interrupts = <2 13 0 2 14 0>;
        interrupt-parent = <&mpc5200_pic>;

        ethernet-switch@0 {
            compatible = "micrel,ks8995m";
            spi-max-frequency = <1000000>;
            reg = <0>;
        };

        codec@1 {
            compatible = "ti,tlv320aic26";
            spi-max-frequency = <100000>;
            reg = <1>;
        };
    };