There is a driver for kernel 2.4 under GPL license under the following link
If anyone could migrate it to the 2.6 kernel it would be very valuable.
Unfortunately, the driver is a proprietary software.
So, it's better not to touch this forbidden fruit ;)
* Copyright 2002 ADVANCED MICRO DEVICES, INC. All Rights Reserved.
* This software and any related documentation (the "Materials") are the
* confidential proprietary information of AMD. Unless otherwise provided
* in an agreement specifically licensing the Materials, the Materials are
* provided in confidence and may not to be used, distributed, modified, or
* reproduced in whole or in part by any means.