Hello,
I'm trying to use PCIe DMA - but I cannot gain access to DMA registers.
It's documented in Application Processor reference Manual chapter 20 HSIO Subsystem in "Figure 20-11. Controller Configuration Space Layout: (RC Mode)" the registers are not part of "Port Logic Registers".
It's documented to use CS2=1 and CDM/ELBI selector bit=1 - than DMA registers can be accessed with an offset 0x8_0000.
But how to select CS2 and CDM/ELBI selector bit?
I've searched a lot but without success.
What do I have to do for accessing DMA regaristers to take advantgae of the 8 DMA channels?
By the way I figured out the following by studying Port Logic Registers between offset 0x700 and 0xD00. At offset 0x970 it seems there are some DMA registers (DMA Global Registers: DMA Arbitration Scheme for TRGT1 Interface) and at offset (0x970 + 0x100) there are the Write Channel 1 Registers.
Additionally I wonder about the number of DMA channels supported: DMA Number of Channels Register (DMA_CTRL_OFF) - by reading this value and what a surprice: there is only 1 reda and 1 Write DMA channel supported.
Can this be true - AFAIK there should 8 Read and 8 Write-channels?
Or is this cause of the "wrong" access mode via unsupported "Port Logic Registers".
Please help ...
And hints are welcome ...
Kind regards
Heiko