1#
2# Copyright (c) 2023 Jamie McCrae
3#
4# SPDX-License-Identifier: Apache-2.0
5#
6
7description: Hitachi HD44780 LCD
8
9compatible: "hit,hd44780"
10
11include: [auxdisplay-device.yaml]
12
13properties:
14  mode:
15    type: int
16    required: true
17    description: Operating mode of display, 8-bit or 4 for 4-bit mode
18    enum:
19      - 4
20      - 8
21
22  register-select-gpios:
23    type: phandle-array
24    required: true
25    description: GPIO connected to Register Select (RS) of LCD
26
27  read-write-gpios:
28    type: phandle-array
29    description: Optional GPIO used for selecting read or write mode
30
31  enable-gpios:
32    type: phandle-array
33    required: true
34    description: GPIO used for enabling commands to be sent
35
36  data-bus-gpios:
37    type: phandle-array
38    required: true
39    description: |
40      Array of GPIOs connected to the DB lines of the display, this must
41      contain 8 entries ascending from DB0 to DB7, for 4-bit interface
42      displays, the first 4 must be set as `<0>`
43
44  brightness-gpios:
45    type: phandle-array
46    description: Optional GPIO used for controlling the brightness (contrast)
47
48  backlight-gpios:
49    type: phandle-array
50    description: Optional GPIO used for enabling the backlight
51
52  line-addresses:
53    type: uint8-array
54    default: [0x00, 0x40, 0x14, 0x54]
55    description: |
56      Array of addresses for each row, will use defaults if not provided.
57      Default is as per Hitachi HD44780 specification.
58
59  enable-line-rise-delay-us:
60    type: int
61    default: 800
62    description: |
63      Delay time (in us) to wait after enable line rises before setting low.
64      Default is as per Hitachi HD44780 specification.
65
66  enable-line-fall-delay-us:
67    type: int
68    default: 100
69    description: |
70      Delay time (in us) to wait after enable line falls before sending
71      another command. Default is as per Hitachi HD44780 specification.
72
73  clear-command-delay-us:
74    type: int
75    default: 5000
76    description: |
77      Delay time (in us) to wait after issuing a clear command before sending
78      another command. Default is as per Hitachi HD44780 specification.
79
80  boot-delay-ms:
81    type: int
82    default: 0
83    description: |
84      Delay time (in ms) to wait at boot time before sending a command (note:
85      this will delay startup of the whole application by this time, this
86      should only be used when time is needed for the display device to be
87      ready before it can be configured which without any delay would cause
88      the display to not function properly).
89