#define USB_REQ_GET_STATUS 0
and in enum
USB_REQ_GET_STATUS = 0;
Presumably you have an enum somewhere:
enum usb_commands {
USB_REQ_GET_STATUS = 0;
... more
};
This is two separate ways of defining constants. Note that you don't REALLY have a problem, since both values are the same; pick one and get rid of the other. Offhand, I'd say that the "webcam" file has no business defining primitive USB constants, and should simply be including the USB_protocol.h file to get those definitions.