Documentation/devicetree/bindings/spi/spi-controller.yaml

# 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).

      So if, for example, the controller has 4 CS lines, and the
      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.

oneOf:
  - required:
      - "#address-cells"
  - required:
      - spi-slave

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:
        description:
          Bus width to the SPI bus used for read transfers.
        $ref: /schemas/types.yaml#/definitions/uint32
        enum: [1, 2, 4, 8]
        default: 1

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

      spi-tx-bus-width:
        description:
          Bus width to the SPI bus used for write transfers.
        $ref: /schemas/types.yaml#/definitions/uint32
        enum: [1, 2, 4, 8]
        default: 1

      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>;
        };
    };