Cypress FX2 Source Code for the DIGIO
This repo contains the uVision project and all associated source files to build the DIGIO USB .hex and .iic files. You'll need to install the Cypress development tools (http://www.cypress.com/?rID=14319) to create the .iic file and load the firmware. The source itself uses a very simple opcode then data protocol via endpoint 1. The opcodes cover both I2C and SPI programming, as well as some information on version, FPGA enable/disable, etc.
This project currently uses a Cypress VID (0x04b4) and random PID, but will hopefully be updated to use an open source VID/PID pair.