I've implemented basic gpsd support. Code is extremely dirty but maybe somebody will find it useful.
Usage:
cd OpenDMTP_client-c_1.2.3
patch -p1 < 0001-Added-basic-gpsd-support.patch
make dest=linux dmtp
./build_lin/dmtpd -gps gpsd
Also make sure you have libgps headers installed. Thanks.
Basic gpsd support