DW3XXX API dwt_probe fails

I´m trying to use the API. Calling dwt_probe((struct dwt_probe_s *)&dw3000_probe_interf) returns -1 (the device answers over SPI 0x02 0x03 0xCA 0xDE).
The dw_driver section is inserted in the Linker script.

What could be the problem?

Regards,
Achim

What is the dw_driver section you inserted into your linker script ? Might be incorrect