dts/bindings/fpga/lattice,ice40-fpga-bitbang.yaml

# Copyright (c) 2022 Meta
# Copyright (c) 2024 SILA Embedded Solutions GmbH
# SPDX-License-Identifier: Apache-2.0

description: Lattice iCE40 FPGA GPIO bitbang based driver

compatible: "lattice,ice40-fpga-bitbang"

include: lattice,ice40-fpga-base.yaml

properties:
  clk-gpios:
    type: phandle-array
    required: true
    description: |
      SPI Clock GPIO input on iCE40.
      Example usage:
      clk-gpios = <&gpio0 5 GPIO_PUSH_PULL>;
  pico-gpios:
    type: phandle-array
    required: true
    description: |
      Peripheral-In Controller-Out GPIO input on iCE40.
      Example usage:
      pico-gpios = <&gpio0 7 GPIO_PUSH_PULL>;
  gpios-set-reg:
    type: int
    required: true
    description: |
      Register address for setting a GPIO.
      Example usage:
      gpios-set-reg = <0x60004008>;
  gpios-clear-reg:
    type: int
    required: true
    description: |
      Register address for clearing a GPIO.
      Example usage:
      gpios-clear-reg = <0x6000400c>;
  mhz-delay-count:
    type: int
    default: 0
    description: |
      in order to create a 1 MHz square wave in the following
      process.
      while(true) {
        *gpios_set_reg |= BIT(n);
        for(int i = mhz_delay_count; i > 0; --i);
        *gpios_clear_reg |= BIT(n);
        for(int i = mhz_delay_count; i > 0; --i);
      }
      The default disables the delay.