and how to write that application . i mean how to configure usb to work under fedora-qt
Jacek has answered your question.
You need to read how to program usb devices under linux.
Jacek provided you with good links to start with.
Using it with Qt is not an issue - since Qt will have nothing to do with the hardware.
Or, ask a more specific questions.
"How to write a USB device driver" is a bit out of the scope of this forum, or any forum.
For that there are tutorials, and howto's.
I would start with libusb docs.