I haven't followed this discussion at all so perhaps you were aware
but this introduces a Sparse warning in linux-next.

drivers/dma/timb_dma.c:168:17: warning: mixing different enum types
drivers/dma/timb_dma.c:168:17:     int enum dma_transfer_direction  versus
drivers/dma/timb_dma.c:168:17:     int enum dma_data_direction 
drivers/dma/timb_dma.c:172:32: warning: mixing different enum types
drivers/dma/timb_dma.c:172:32:     int enum dma_transfer_direction  versus
drivers/dma/timb_dma.c:172:32:     int enum dma_data_direction 

regards,
dan carpenter