Hans Verkuil Most of the contents of this document has been moved to the linux kernel documentation's Admin Guide (see link below). CEC Documentation ================= Public API: https://www.linuxtv.org/downloads/v4l-dvb-apis-new/uapi/cec/cec-api.html Kernel API: https://www.linuxtv.org/downloads/v4l-dvb-apis-new/kapi/cec-core.html Admin Guide: https://linuxtv.org/downloads/v4l-dvb-apis-new/admin-guide/cec.html CEC Status ========== Core Framework: - Still to do: Media Controller integration. - Do something with devices that can wake up the main CPU. USB dongles support this, but also some SoC hardware. Basically the CEC part remains running while the everything else is in standby and it can wake up the main CPU when a IMAGE/TEXT_VIEW_ON message arrives. Currently this is only supported in the Pulse-Eight driver through a module option. But it would be nice to have a proper API to control this. Something to think about. - Support for a new CEC_ADAP_G_CONNECTOR_INFO ioctl arrived in kernel 5.5. This change prepares the way for a CEC_ADAP_S_CONNECTOR_INFO to associate a Pulse-Eight device (or a similar device) with an HDMI connector. And to allow for multiple CEC adapters to be associated with a single HDMI connector (one simple adapter for standby and another when powered on). Drivers in progress =================== - While DisplayPort CEC-Tunneling-over-AUX has been accepted for 4.19, it is not supported for MST scenarios. This is due to limitations of the MST implementations. Update: support for CEC in MST scenarios was added to DisplayPort 2.0, Errata 5. Patches adding support for this (based in part on my original experimental patches) were posted by Google but still need more testing. Work is being done (2023) to finally get this in. - A CEC implementation for the Toshiba tc358840 exists, but this driver hasn't been merged yet (still more work to be done). - omap5/am57xx/dra7xx: I got this to work except for the corner case where there is no HPD and you want to send a CEC message. I have not had the time to finalize this and I am currently waiting for a large reorg of the TI DSS code to be merged before continuing with this. This reorg is merged in 5.7, so I hope to be able to work on omap5 support.