The documentation on the SPI peripheral says:
Two DMA channels are required, one to read from and one to write to the SPI.
Is this necessarily true? I have a device where I need to write a few bytes by SPI and then receive a very large amount of data (eg 32k) back over SPI.
Is it possible to do the write portion (ie sending a few bytes to the slave) by directly accessing the SPI peripheral, then setting up DMA to receive the response back? Or do I need to set up two DMA transfers, one of which writes a few significant bytes and then a big pile of junk, and the other receives a few bytes of junk and then 32k of interesting data?