ddcutil

Usage:

Show info:

ddcutil detect --verbose

Show availbable settings:

ddcutil getvcp known --bus 8

Show available options for settings, i.e. for Feature: 60 (Input Source):

$ ddcutil capabilities --display 1 --verbose
…
Feature: 60 (Input Source)
  Values (unparsed): 11 12 0F 10
  Values (  parsed):
      11: HDMI-1
      12: HDMI-2
      0f: DisplayPort-1
      10: DisplayPort-2

Dump VCP:

ddcutil dumpvcp --display 1 ~/.config/ddcutil/profiles/GSM-LG_HDR_5K-30495-hdmi1.cfg

LG HDR 5K

Issue: Unable to switch input source

$ ddcutil --display 1 getvcp 60
VCP code 0x60 (Input Source                  ): Invalid value (sl=0x00)

Switching input source on LG monitors
- Also doesn't work

Tools / wrappers

ddctui
- ddctui AUR package
- I.e. Brightness control
ddcui
- Only displays information, pretty useless