dt-bindings: pinctrl: Add support for canaan,k230 SoC

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/pinctrl/canaan,k230-pinctrl.yaml#

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

title: Canaan Kendryte K230 Pin Controller

maintainers:

  - Ze Huang <18771902331@163.com>

description:

  The Canaan Kendryte K230 platform includes 64 IO pins, each capable of

  multiplexing up to 5 different functions. Pin function configuration is

  performed on a per-pin basis.

properties:

  compatible:

    const: canaan,k230-pinctrl

  reg:

    maxItems: 1

patternProperties:

  '-pins$':

    type: object

    additionalProperties: false

    description:

      A pinctrl node should contain at least one subnode representing the

      pinctrl groups available on the machine.

    patternProperties:

      '-cfg$':

        type: object

        allOf:

          - $ref: /schemas/pinctrl/pincfg-node.yaml

          - $ref: /schemas/pinctrl/pinmux-node.yaml

        additionalProperties: false

        description:

          Each subnode will list the pins it needs, and how they should

          be configured, with regard to muxer configuration, bias, input

          enable/disable, input schmitt trigger, slew-rate enable/disable,

          slew-rate, drive strength.

        properties:

          pinmux:

            description:

              The list of GPIOs and their mux settings that properties in

              the node apply to. This should be set with the macro

              'K230_PINMUX(pin, mode)'

          bias-disable: true

          bias-pull-up: true

          bias-pull-down: true

          drive-strength:

            minimum: 0

            maximum: 15

          input-enable: true

          output-enable: true

          input-schmitt-enable: true

          slew-rate:

            description: |

              slew rate control enable

              0: disable

              1: enable

            enum: [0, 1]

          power-source:

            description: |

              Specifies the power source voltage for the IO bank that the

              pin belongs to. Each bank of IO pins operate at a specific,

              fixed voltage levels. Incorrect voltage configuration can

              damage the chip. The defined constants represent the

              possible voltage configurations:

              - K230_MSC_3V3 (value 0): 3.3V power supply

              - K230_MSC_1V8 (value 1): 1.8V power supply

              The following banks have the corresponding voltage

              configurations:

              - bank IO0 to IO1: Fixed at 1.8V

              - bank IO2 to IO13: Fixed at 1.8V

              - bank IO14 to IO25: Fixed at 1.8V

              - bank IO26 to IO37: Fixed at 1.8V

              - bank IO38 to IO49: Fixed at 1.8V

              - bank IO50 to IO61: Fixed at 3.3V

              - bank IO62 to IO63: Fixed at 1.8V

            enum: [0, 1]

        required:

          - pinmux

required:

  - compatible

  - reg

additionalProperties: false

examples:

  - |

    pinctrl@91105000 {

        compatible = "canaan,k230-pinctrl";

        reg = <0x91105000 0x100>;

        uart2-pins {

            uart2-pins-cfg {

                pinmux = <0x503>, /* uart2 txd */

                         <0x603>; /* uart2 rxd */

                slew-rate = <0>;

                drive-strength = <4>;

                power-source = <1>;

                input-enable;

                output-enable;

                bias-disable;

            };

        };

    };