How do I get a PS3 Sixasis Controller working via USB?
Solution 1:
I have read something about it and I think it would be better to connect PS3 controller using bluetooth directly. Take a look of this.
I have read your limitations, and I still think that you need to use bluetooth. you could Buy a Bluetooth USB dongle, they are cheap (dealextreme.com/p/…).
Solution 2:
I'm not sure if this will help, but when I set up my PS2 controller to play emulators I used jstest-gtk.
It took a little bit of time to get it set up between jstest-gtk and the emulator (I use ZSNES). After getting the controller to read properly through jstest-gtk I had to go into my emulator and assign all the buttons. (I had thought it would auto-detect the controller but it didn't.) It works great; I've not had any problems with it.
Like I said, I don't know if it will work for a PS3 controller though, but it might be worth the try.