Does ADI's Linux SPI Engine driver (spi-axi-spi-engine) support 3-wire operation? I have had a lot of success accessing a 4-wire device using this engine, but initiating a transfer in 3-wire mode results in error code -22. I am using ADI's 2016_R1 branch of the kernel and I see some references to things like "SPI_ENGINE_CONFIG_3WIRE" and "SPI_3WIRE" in spi-axi-spi-engine.c but it is not clear to me if this functionality is fully implemented. Once I can confirm 3-wire mode is supported, I can provide some extra diagnostic information so we can hopefully find a solution. I am also eager to supply more documentation for the wiki once my design is working.