dts/bindings/auxdisplay/hit,hd44780.yaml

#
# Copyright (c) 2023 Jamie McCrae
#
# SPDX-License-Identifier: Apache-2.0
#

description: Hitachi HD44780 LCD

compatible: "hit,hd44780"

include: [auxdisplay-device.yaml]

properties:
  mode:
    type: int
    required: true
    description: Operating mode of display, 8-bit or 4 for 4-bit mode
    enum:
      - 4
      - 8

  register-select-gpios:
    type: phandle-array
    required: true
    description: GPIO connected to Register Select (RS) of LCD

  read-write-gpios:
    type: phandle-array
    description: Optional GPIO used for selecting read or write mode

  enable-gpios:
    type: phandle-array
    required: true
    description: GPIO used for enabling commands to be sent

  data-bus-gpios:
    type: phandle-array
    required: true
    description: |
      Array of GPIOs connected to the DB lines of the display, this must
      contain 8 entries ascending from DB0 to DB7, for 4-bit interface
      displays, the first 4 must be set as `<0>`

  brightness-gpios:
    type: phandle-array
    description: Optional GPIO used for controlling the brightness (contrast)

  backlight-gpios:
    type: phandle-array
    description: Optional GPIO used for enabling the backlight

  line-addresses:
    type: uint8-array
    default: [0x00, 0x40, 0x14, 0x54]
    description: |
      Array of addresses for each row, will use defaults if not provided.
      Default is as per Hitachi HD44780 specification.

  enable-line-rise-delay-us:
    type: int
    default: 800
    description: |
      Delay time (in us) to wait after enable line rises before setting low.
      Default is as per Hitachi HD44780 specification.

  enable-line-fall-delay-us:
    type: int
    default: 100
    description: |
      Delay time (in us) to wait after enable line falls before sending
      another command. Default is as per Hitachi HD44780 specification.

  clear-command-delay-us:
    type: int
    default: 5000
    description: |
      Delay time (in us) to wait after issuing a clear command before sending
      another command. Default is as per Hitachi HD44780 specification.

  boot-delay-ms:
    type: int
    default: 0
    description: |
      Delay time (in ms) to wait at boot time before sending a command (note:
      this will delay startup of the whole application by this time, this
      should only be used when time is needed for the display device to be
      ready before it can be configured which without any delay would cause
      the display to not function properly).