Yes, I agree that it’s rather complex to follow. Looking at the schematics from the board schematics document, you can see the line-in jack connections and follow them via the labels into RAUX and LAUX as I did in the diagram below.
I then circled the connections between the CODEC and the names of the various connections to the Zynq device on the left side of the diagram. The trick I found for figuring out which pin each is connected to on the Zynq is to search for the name of each line, such as “AU_DOUT”. Searching for that name will show that it’s connected to “F17” on page 11. One can do the same for the other relevant lines.
