I can not speak to the hardware aspect of all this. Gerald would probably know better than anyone else anyhow.
However, there are tools such as universal IO https://github.com/cdsteinkuehler/beaglebone-universal-io that can be used to configure pins from user space. I've yet to use it myself but it stands to reason that this could be used to help solve your problem. Now . . . how well the adafruit BBIO library / driver plays with universal IO, I'm not sure . . . One other caveat that I can think of that perhaps you already know. Is that with kernels 3.8.x it is not ( or was not ) possible to unload a device tree blobs once the kernel is loaded and running. 3.14.x has no capemgr, and I'm not sure how well along 4.1.x is as far as ready for "prime time". 4.1.x seemed fairly decent when I tested it, but it is still a work in progress . . .and I did not test SPI ( only CANBus + ethernet ). On Mon, Jul 6, 2015 at 5:18 PM, Gerald Coley <[email protected]> wrote: > The AM3358 does not support tri-state on GPIO pins. > > Gerald > > > On Mon, Jul 6, 2015 at 4:24 PM, <[email protected]> wrote: > >> Hello All, >> >> I've have a BeagleBone Black connected with SPI0 to an FPGA and also to >> it's configuration flash memory device on a cape we are developing. On >> power up, the FPGA will configure correctly from the serial. (SPIDEV0 is >> not enabled in the device tree). I can also reprogram the flash with SPI0 >> at this point. The idea is that either the BBB or the FPGA will talk to >> the flash and the other will be tri-stated. >> >> I'm using the Adafruit_BBIO driver to communicate with the FPGA over SPI0 >> (using Python). >> >> The issue I have is that when I exit the Python program, the SPI0 pins >> are still configured for SPI (even after using the SPI.close() function in >> the program). I'm looking at the cape manager slots after the program >> exits and SPIDEV0 is now loaded. After that, I'm not able to >> re-configure the FPGA because the SPI lines are being driven by the BBB. >> >> The question is: Is it possible to tri-state the SPI0 lines or switch >> the SPI0 lines back to GPIO inputs before I exit the python program? >> >> Any insight is appreciated. >> >> Thanks, >> Dave >> >> David Hunter >> Sr. Electrical Engineer >> SkuTek Instrumentation >> W. Henrietta, NY >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Gerald > > [email protected] > http://beagleboard.org/ > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
