Guys,
I am working with a Cypress EZ-USB FX2 prototyping board connected to an Omnivision camera chip that spits out data far faster than the GPIF's Endpoint buffers are programmed to handle. The Keil uVision compiler is used for the firmware and libusb 0.1.12.0 for enumerating the USB devices at the PC end.
I am using Control Requests, (or Vendor Requests in GPIF parlance) to communicate with the development board and the Camera chip. These work find for turning LEDs on and off and sending the Camera chip to sleep etc. However, when I attempt the bulk read transer below, I get the following error message:
Bulk Read Vendor Request failed (-22). usb_submit_async: submitting request failed, win error: The parameter is incorrect.
I have checked the parameters of the usb_bulk_read() call and I don't find any obvious discrepancies, so I assume that there is a problem with my firmware.
Could someone please offer me a code snippet for buffering Camera output on the GPIF chip, (if that is what the problem is).
Thank you for your time, Gavin Brewer.