Hi,
I'm trying to write a bare metal SPI driver using DMA for my DM8148 processor. I have a non-DMA version working fine with an NVSRAM device connected to SPI2 on the processor but I'm having problems modifying it to use DMA.
I cannot seem to get the SPI device to actually generate DMA Synchronization Events even after setting the DMAR and DMAW bits in the MCSPI_CH2CONF register. I think I am monitoring the correct DMA events but I have found the TRM slightly confusing here. Section 22.2.6 states that there are 2 DMA request lines per channel but table 1-102 in section 1.7.5 shows 4 events with SPI2 as the source?
As these are multiplexed events I have used the EDMA3CC_EVTMUX_8_11 / 12_15 registers to map all 4 to events 9, 10, 11 and 12 but I never see any of these being asserted.
Is there anything I need to do or should be aware of to get the SPI device to issue the Events?