It isn't documented. I figured it out by looking at the github you linked and th...

ali1234 on Feb 8, 2015 | parent | context | favorite | on: Teletext for Raspberry Pi

It isn't documented. I figured it out by looking at the github you linked and then looking at register values and trying to guess what they mean.

About the pixel valves.

The chip has three pixel valves. One is for DSI0, one is for DSI1, and the final one (pixel valve 2) is shared between HDMI and composite.

lovelearning on Feb 9, 2015 [–]

Thank you for the info, Alistair! Nice work.