dts/bindings/gpio/gpio-controller.yaml

# Copyright (c) 2019, Linaro Limited
# SPDX-License-Identifier: Apache-2.0

# Common fields for GPIO controllers

properties:
  "gpio-controller":
    type: boolean
    required: true
    description: Convey's this node is a GPIO controller
  "#gpio-cells":
    type: int
    required: true
    description: Number of items to expect in a GPIO specifier
  ngpios:
    type: int
    default: 32
    description: |
        This property indicates the number of in-use slots of available slots
        for GPIOs. The typical example is something like this: the hardware
        register is 32 bits wide, but only 18 of the bits have a physical
        counterpart. The driver is generally written so that all 32 bits can
        be used, but the IP block is reused in a lot of designs, some using
        all 32 bits, some using 18 and some using 12. In this case, setting
        "ngpios = <18>;" informs the driver that only the first 18 GPIOs, at
        local offset 0 .. 17, are in use.  For cases in which there might be
        holes in the slot range, this value should be the max slot number-1.
  gpio-reserved-ranges:
    type: array
    description: |
        If not all the GPIOs at offsets 0...N-1 are usable for ngpios = <N>, then
        this property contains an additional set of tuples which specify which GPIOs
        are unusable. This property indicates the start and size of the GPIOs
        that can't be used.

        For example, setting "gpio-reserved-ranges = <3 2>, <10 1>;" means that
        GPIO offsets 3, 4, and 10 are not usable, even if ngpios = <18>.
  gpio-line-names:
    type: string-array
    description: |
        This is an array of strings defining the names of the GPIO lines
        going out of the GPIO controller

child-binding:
  description: |
    Optional GPIO hog configuration.

    Each GPIO controller may contain GPIO hog definitions. GPIO hogging is a mechanism for
    providing automatic GPIO configuration during driver initialization when Kconfig
    CONFIG_GPIO_HOGS is enabled.

    Each GPIO hog is represented as a child node of the GPIO controller.

    Example:
      &gpio1 {
        mux-hog {
          gpio-hog;
          gpios = <10 GPIO_ACTIVE_HIGH>, <11 GPIO_ACTIVE_HIGH>;
          output-high;
        };
      };

      &gpio2 {
        test-hog {
          gpio-hog;
          gpios = <26 GPIO_ACTIVE_HIGH>;
          output-low;
          line-name = "test";
      };
    };

  properties:
    gpio-hog:
      type: boolean
      required: true
      description: |
        Conveys this node is a GPIO hog.
    gpios:
      type: array
      required: true
      description: |
        This is an array of GPIO specifiers (e.g. pin, flags) to be hogged. The number of array
        entries must be an integer multiple of the number of GPIO specifier cells for the parent
        GPIO controller.
    input:
      type: boolean
      description: |
        If this property is set, the GPIO is configured as an input. This property takes
        precedence over the output-low and output-high properties.
    output-low:
      type: boolean
      description: |
        If this property is set, the GPIO is configured as an output set to logical low. This
        property takes precedence over the output-high property.
    output-high:
      type: boolean
      description: |
        If this property is set, the GPIO is configured as an output set to logical high.
    line-name:
      type: string
      description: |
        Optional GPIO line name.