AM5728: Reading FPGA from linux

Stanley Wood

Part Number: AM5728

I have the device tree set up for gpmc. I have the pinmux defined for the FPGA. And the base address of chip select 0 is set to physical address 0x01000000. But how to I access the driver on the ARM side under linux. In otherwords what do I call to read or write to the fpga via the gpmc? An short little code snippet sure would be helpful

over 4 years ago

0 Keerthy J over 4 years ago

TI__Guru**** 166240 points

Hello Stanley,

I was going through some older E2E threads for AM43xx/AM335x & I see devmem2 as one of the most
commonly used tool from Linux to read write to FPGA based address space.

Check this link: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/793386/linux-am5728-gpmc-accessing-an-external-memory-fgpa/2945325#2945325

Since your mapped address is 0x01000000.

Can you try:

'devmem2 0x01000000 w'

Best Regards,
Keerthy

0 Stanley Wood over 4 years ago in reply to Keerthy J

Prodigy 40 points

Yes I was able to read 0x0100000 with devmem2. I guess I should just look at the source to devmem2.c to determine how to add the ability to read the fpga from the ARM.

+1 Keerthy J over 4 years ago in reply to Stanley Wood

TI__Guru**** 166240 points

Yes that is something that is widely suggested as a user space application from Linux. If no further questions please click on verify answer.

- Keerthy

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AM5728: Reading FPGA from linux