FT2232H_D2XX_linux
minimalist example of full duplex SPI on an FT2232H chip, at USB2.0 speeds.
Update 1/19/21 - tested on OSX 10.14.6 using D2XX 1.14.16 , and Ubuntu Linux.
Based on AN_114.pdf from FTDI
See: http://www.ftdichip.com/Support/Documents/AppNotes/AN_114_FTDI_Hi_Speed_USB_To_SPI_Example.pdf
To use download the drivers and follow the instructions at :
https://ftdichip.com/drivers/d2xx-drivers/
add this in to the example projects and compile it!
Background:
I had a hell of a time trying to find any examples of a working driver for an FT2232H chip. The example in Application Note 114, was designed for D2XX on windows, so I set out re writing it line by line for linux. This is a copy of my file before it got much more complicated. It might not be perfect, but its a working example, simple , and a lot closer than the PDF is to getting you up and running.
I was told D2XX doesnt work on linux and to use LIBFTDI instead, but I actually got it working and its FAST!. D2XX is FTDI's native- closed source library with windows compatibility , so be aware it may not be the first option for your design.
The defualt driver is the Virtual Com Port driver , it starts automatically when the device is plugged in. To develop d2xx drivers you have to temporarily remove VCP (until device is reset or power cycled):
sudo rmmod ftdi_sio; sudo rmmod usbserial;