Reading and Writing to GPIO over PCIe

[zwilcox]

Hey All!

I'm attempting to read and write some bytes in Python to GPIO over PCIe on my AC701.

I've done this same task with the same Python code and it worked.  I have since recreated the Project in Vivado and now it doesn't work.  Thus I suspect there's something up with my Vivado stuff.

Here's my block diagram and addressing

The device enumerates.   When I run the lspci -vv I get the following:

My python code:

import os
import mmap

os.system('setpci -s "01:00.0" COMMAND=0x02')
resource0 = os.open("/sys/bus/pci/devices/0000:01:00.0/resource0", os.O_RDWR | os.O_SYNC)

memFile = os.open("/dev/mem",  os.O_RDWR | os.O_SYNC)

startAddr = 0xe0000000;

resourceSize = os.fstat(resource0).st_size

print 'size is ' + str(resourceSize) + ' bytes'
mem1 = mmap.mmap(memFile, resourceSize, flags=mmap.MAP_SHARED, prot=mmap.PROT_WRITE|mmap.PROT_READ, offset = startAddr)
mem2 = mmap.mmap(resource0, resourceSize, flags=mmap.MAP_SHARED, prot=mmap.PROT_WRITE|mmap.PROT_READ, offset = 0)

mem1[0] = '\xFF'
mem2[0] = '\xFF' #this used to work!!

Writing either mem1[0] and mem2[0] does nothing.

I get an error when I read either mem1 or mem2.

[  180.156142] nwl-pcie fd0e0000.pcie: Non-Fatal Error Detected

[zwilcox · Accepted solution]

Ugh!

My reset was wrong.  *sigh*