DDC/CI is a protocol designed by VESA to configure a monitor by software, using an I2C bus carried by display connectors such as VGA, DVI, HDMI, and DisplayPort.

DDCcontrol accesses that bus from userspace through the operating system's /dev/i2c-* devices. Legacy direct PCI memory access and AMD ADL backends have been removed. USB-connected DDC/CI displays are not supported yet.