i2c-dev

• i2c-dev is the module to control external monitor brightness over I2C
• https://www.reddit.com/r/kde/comments/epgs13/kde_my_journey_to_get_a_brighness_slider_for_my/

modprobe i2c_dev # Manual one-time load

# /etc/modules-load.d/i2c_dev.conf
i2c_dev

• ddcutil packages contains a tools to manage the capabilities
• i2c-tools is necessary for a good integration with the module. Remember to set the correct permissions. (installed as dependency of ddcutil)