cec-ctl

kernel CEC device control tool

TLDR

List the CEC adapters the kernel knows about

$ cec-ctl --list-devices

Show the topology of the HDMI bus

$ cec-ctl --show-topology

$ sudo cec-ctl --playback --osd-name [MyPC]

Set the physical address by hand

$ sudo cec-ctl --phys-addr [1.0.0.0]

Wake the TV and have it switch to this input

$ cec-ctl --to 0 --image-view-on

Announce this device as the active source

$ cec-ctl --active-source phys-addr=[1.0.0.0]

Put the TV into standby

$ cec-ctl --to 0 --standby

Ask the TV for its power state

$ cec-ctl --to 0 --give-device-power-status

Watch the traffic addressed to this adapter

$ sudo cec-ctl --monitor

Watch every message on the bus, addressed to us or not

$ sudo cec-ctl --monitor-all

Work with a specific adapter

$ cec-ctl -d [/dev/cec1] --show-topology

Clear the adapter's configuration

$ sudo cec-ctl --clear

cec-ctl controls kernel CEC (Consumer Electronics Control) devices through the Linux kernel's native CEC framework. It provides low-level access to the CEC subsystem for monitoring traffic, configuring adapters, and sending commands directly via the kernel driver.Unlike cec-client which relies on the userspace libCEC library and requires a USB CEC adapter, cec-ctl works with CEC hardware integrated into graphics cards and SoCs that expose `/dev/cecN` device nodes. This makes it the preferred tool on platforms with built-in CEC support, such as many ARM-based media players and modern Intel GPUs.The monitor mode (`-m`) is particularly useful for debugging CEC communication issues, as it displays all CEC traffic on the bus in real time.