EXTERNAL
REASON: THE DATASHEET IS NOT CLEAR ABOUT HOW THE HDMI AUDIO CAN BE RECEIVED ON THE LOCAL I2S PINS
SOURCE: APP SUPPORT ENGINEERS
This use case shown by the illustration below is unfortunately not supported.
Only the forward channel supports audio source from HDMI .
The examples in the GMSL 2 general userguide are for HDMI audio forward channel setup only, i.e. the data is passed from HDMI over the GMSL link to the deserializer end where the HDMI audio can be received on the deserializer's I2S pins. gmsl2-general-user-guide.pdf (section 15.3.2.1)
However, the audio may be looped back from deserializer end to the serializer side once received, but a deserializer companion chip (e.g. MAX96752) is needed in this case.
A reverse audio channel from deserializer to serializer is also supported. The deserializer receives the audio on the I2S input pins and transmits the audio data back over the serial link. The serializer receives the audio data from the serial link, reconstructs the audio, and outputs the data to the local I2S pins.
For more details on setting up the forward and reverse audio channel, refer to Table 49 on the userguide. gmsl2-general-user-guide.pdf