I am working on a custom board that is based on the ConnectCard i.mx28. I need to include drivers for the FT4222H USB-to-SPI bridge.
Initially, I cross-compiled the direct (D2XX) drivers and tried to test some of the basic functions, but the FTDI-provided examples exit with errors. Upon further investigation, the errors are related to invocation of the libusb libraries.
Taking a step back, I observe similar problems when running the lsusb utility on this board and also see the same problem on the Digi Jumpstart board (ccardimx28js) that was used for initial evaluation.
To recap, lsusb fails as follows. I set the libusb debug level to get insight into the "why" of the failure.
root@ccardimx28js:~# export LIBUSB_DEBUG=4
libusb: 0.000000 error [op_init] could not find usbfs
unable to initialize libusb: -99
I believe it has to do with the paths searched, but do not know how to reconcile where Digi's embedded Linux setup puts things w.r.t. where libusb is looking.
Any thoughts are sincerely appreciated.