I'm working with the demo_apps/sai example code. Specifically the recordplayback.c loop. This is a nice example to gain better familiarity with eDMA and SAI. I have a mic/headset plugged into the MIMXRT1060EVK and when I run the application I can tap on the on-board mic and I hear that noise in both headset channels; however, I do not hear anything coming from the headset microphone.
Digging a bit more I found that the initialized wm8960Config structure did not have the leftInputSource member configured (hence it defaults to 0, which is kWM8960_InputClosed). Based on the schematic it appears that it should be set to kWM8960_InputDifferentialMicInput3, but that didn't make any difference.
My guess is that this is a correct change, and that something else up the chain (SAI or eDMA) is causing the left/right mapping to get confused (I'm suspicious of this because the on-board mic is heard in both channels). I want both channels active in both directions so I can then get a better understanding of how SAI/eDMA and the Codec are working together.