I'm trying to configure an imx RT1020 board to do an audio transfer from 1 input to 2 outputs. All lines are mapped to SAI1 and I'm using channel 0 for RX and channels 1 and 2 for TX.
I've been trying for some time now to use the SDK sai_edma workflow, based on the evkmimxrt1020_sai_edma_transfer example. I can successfully setup 1 channel in and 1 channel out, however things get more complicated when I try to include the second TX channel. It appears that the SDK isn't designed for multi-channel SAI edma transfers (e.g. in the function SAI_TransferTxCreateHandleEDMA there's a private handle (s_edmaPrivateHandle) that's used for each TX handle, so I shouldn't really be using 2 different handles. And if I try to manually change the handle.channel value before calling SAI_TransferSendEDMA, I get weird behaviours in the outputs).
My guess is that I can't use a single edma handler for both channels, since each edma handler is naturally assigned to a dma channel.
My question is: is there a correct way to setup the SAI edma for multi-channel usage using the SDK or do I need to go around it?
Thank you for your time!