dt-bindings: soc: microchip: document PolarFire SoC's gpio interrupt mux

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/soc/microchip/microchip,mpfs-irqmux.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Microchip Polarfire SoC GPIO Interrupt Mux

maintainers:

  - Conor Dooley <conor.dooley@microchip.com>

description: |

  There are 3 GPIO controllers on this SoC, of which:

  - GPIO controller 0 has 14 GPIOs

  - GPIO controller 1 has 24 GPIOs

  - GPIO controller 2 has 32 GPIOs

  All GPIOs are capable of generating interrupts, for a total of 70.

  There are only 41 IRQs available however, so a configurable mux is used to

  ensure all GPIOs can be used for interrupt generation.

  38 of the 41 interrupts are in what the documentation calls "direct mode",

  as they provide an exclusive connection from a GPIO to the PLIC.

  Lines 18 to 23 on GPIO controller 1 are always in "direct mode".

  The 3 remaining interrupts are used to mux the interrupts which do not have

  a exclusive connection, one for each GPIO controller.

properties:

  compatible:

    const: microchip,mpfs-irqmux

  reg:

    maxItems: 1

  "#address-cells":

    const: 0

  "#interrupt-cells":

    const: 1

  interrupt-map-mask:

    items:

      - const: 0x7f

  interrupt-map:

    description: |

      Specifies the mapping from GPIO interrupt lines to plic interrupts.

      The child interrupt number set in arrays items is computed using the

      following formula:

          gpio_bank * 32 + gpio_number

      with:

        - gpio_bank: The GPIO bank number

            - 0 for GPIO0,

            - 1 for GPIO1,

            - 2 for GPIO2

        - gpio_number: Number of the gpio in the bank (0..31)

    maxItems: 70

required:

  - compatible

  - reg

  - "#address-cells"

  - "#interrupt-cells"

  - interrupt-map-mask

  - interrupt-map

additionalProperties: false

examples:

  - |

    interrupt-controller@54 {

        compatible = "microchip,mpfs-irqmux";

        reg = <0x54 0x4>;

        #address-cells = <0>;

        #interrupt-cells = <1>;

        interrupt-map-mask = <0x7f>;

        interrupt-map = <0 &plic 13>, <1 &plic 14>, <2 &plic 15>,

                        <3 &plic 16>, <4 &plic 17>, <5 &plic 18>,

                        <6 &plic 19>, <7 &plic 20>, <8 &plic 21>,

                        <9 &plic 22>, <10 &plic 23>, <11 &plic 24>,

                        <12 &plic 25>, <13 &plic 26>,

                        <32 &plic 27>, <33 &plic 28>, <34 &plic 29>,

                        <35 &plic 30>, <36 &plic 31>, <37 &plic 32>,

                        <38 &plic 33>, <39 &plic 34>, <40 &plic 35>,

                        <41 &plic 36>, <42 &plic 37>, <43 &plic 38>,

                        <44 &plic 39>, <45 &plic 40>, <46 &plic 41>,

                        <47 &plic 42>, <48 &plic 43>, <49 &plic 44>,

                        <50 &plic 45>, <51 &plic 46>, <52 &plic 47>,

                        <53 &plic 48>, <54 &plic 49>, <55 &plic 50>,

                        <64 &plic 53>, <65 &plic 53>, <66 &plic 53>,

                        <67 &plic 53>, <68 &plic 53>, <69 &plic 53>,

                        <70 &plic 53>, <71 &plic 53>, <72 &plic 53>,

                        <73 &plic 53>, <74 &plic 53>, <75 &plic 53>,

                        <76 &plic 53>, <77 &plic 53>, <78 &plic 53>,

                        <79 &plic 53>, <80 &plic 53>, <81 &plic 53>,

                        <82 &plic 53>, <83 &plic 53>, <84 &plic 53>,

                        <85 &plic 53>, <86 &plic 53>, <87 &plic 53>,

                        <88 &plic 53>, <89 &plic 53>, <90 &plic 53>,

                        <91 &plic 53>, <92 &plic 53>, <93 &plic 53>,

                        <94 &plic 53>, <95 &plic 53>;

    };

      of PolarFire clock/reset IDs.

    const: 1

  interrupt-controller@54:

    type: object

    $ref: /schemas/soc/microchip/microchip,mpfs-irqmux.yaml

  pinctrl@200:

    type: object

    $ref: /schemas/pinctrl/microchip,mpfs-pinctrl-iomux0.yaml