Documentation/devicetree/bindings/pinctrl/thead,th1520-pinctrl.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/pinctrl/thead,th1520-pinctrl.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: T-Head TH1520 SoC pin controller

maintainers:
  - Emil Renner Berthing <emil.renner.berthing@canonical.com>

description: |
  Pinmux and pinconf controller in the T-Head TH1520 RISC-V SoC.

  The TH1520 has 3 groups of pads each controlled from different memory ranges.
  Confusingly the memory ranges are named
    PADCTRL_AOSYS  -> PAD Group 1
    PADCTRL1_APSYS -> PAD Group 2
    PADCTRL0_APSYS -> PAD Group 3

  Each pad can be muxed individually to up to 6 different functions. For most
  pads only a few of those 6 configurations are valid though, and a few pads in
  group 1 does not support muxing at all.

  Pinconf is fairly regular except for a few pads in group 1 that either can't
  be configured or has some special functions. The rest have configurable drive
  strength, input enable, schmitt trigger, slew rate, pull-up and pull-down in
  addition to a special strong pull up.

  Certain pads in group 1 can be muxed to AUDIO_PA0 - AUDIO_PA30 functions and
  are then meant to be used by the audio co-processor. Each such pad can then
  be further muxed to either audio GPIO or one of 4 functions such as UART, I2C
  and I2S. If the audio pad is muxed to one of the 4 functions then pinconf is
  also configured in different registers. All of this is done from a different
  AUDIO_IOCTRL memory range and is left to the audio co-processor for now.

properties:
  compatible:
    enum:
      - thead,th1520-pinctrl
  reg:
    maxItems: 1

  clocks:
    maxItems: 1

  thead,pad-group:
    description: |
      Select the pad group that is associated with the pin controller instance.

        Base Address   Name           Group
        0xFF_FFF4_A000 PADCTRL_AOSYS  1
        0xFF_E7F3_C000 PADCTRL1_APSYS 2
        0xFF_EC00_7000 PADCTRL0_APSYS 3

    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [1, 2, 3]

required:
  - compatible
  - reg
  - clocks

patternProperties:
  '-[0-9]+$':
    type: object
    additionalProperties: false

    patternProperties:
      '-pins$':
        type: object
        allOf:
          - $ref: /schemas/pinctrl/pincfg-node.yaml#
          - $ref: /schemas/pinctrl/pinmux-node.yaml#

        additionalProperties: false

        description:
          A pinctrl node should contain at least one subnode describing one
          or more pads and their associated pinmux and pinconf settings.

        properties:
          pins:
            description: List of pads that properties in the node apply to.

          function:
            enum: [ gpio, pwm, uart, ir, i2c, spi, qspi, sdio, audio, i2s,
                    gmac0, gmac1, dpu0, dpu1, isp, hdmi, bootsel, debug,
                    clock, jtag, iso7816, efuse, reset ]
            description: The mux function to select for the given pins.

          bias-disable: true

          bias-pull-up:
            oneOf:
              - type: boolean
                description: Enable the regular 48kOhm pull-up
              - enum: [ 2100, 48000 ]
                description: Enable the strong 2.1kOhm pull-up or regular 48kOhm pull-up

          bias-pull-down:
            oneOf:
              - type: boolean
              - const: 44000
            description: Enable the regular 44kOhm pull-down

          drive-strength:
            enum: [ 1, 2, 3, 5, 7, 8, 10, 12, 13, 15, 16, 18, 20, 21, 23, 25 ]
            description: Drive strength in mA

          input-enable: true

          input-disable: true

          input-schmitt-enable: true

          input-schmitt-disable: true

          slew-rate:
            maximum: 1

        required:
          - pins

additionalProperties: false

examples:
  - |
    padctrl0_apsys: pinctrl@ec007000 {
        compatible = "thead,th1520-pinctrl";
        reg = <0xec007000 0x1000>;
        clocks = <&apb_clk>;
        thead,pad-group = <3>;

        uart0_pins: uart0-0 {
            tx-pins {
                pins = "UART0_TXD";
                function = "uart";
                bias-disable;
                drive-strength = <3>;
                input-disable;
                input-schmitt-disable;
                slew-rate = <0>;
            };

            rx-pins {
                pins = "UART0_RXD";
                function = "uart";
                bias-disable;
                drive-strength = <1>;
                input-enable;
                input-schmitt-enable;
                slew-rate = <0>;
            };
        };
    };

    padctrl1_apsys: pinctrl@e7f3c000 {
        compatible = "thead,th1520-pinctrl";
        reg = <0xe7f3c000 0x1000>;
        clocks = <&apb_clk>;
        thead,pad-group = <2>;

        i2c5_pins: i2c5-0 {
            i2c-pins {
                pins = "QSPI1_CSN0",    /* I2C5_SCL */
                       "QSPI1_D0_MOSI"; /* I2C5_SDA */
                function = "i2c";
                bias-pull-up = <2100>;
                drive-strength = <7>;
                input-enable;
                input-schmitt-enable;
                slew-rate = <0>;
            };
        };
    };