fw_open_isodma
int (*fw_open_isodma)(struct firewire_comm *fc, int tx);
int fw_open_isodma(struct firewire_comm *, int);
fw_open_isodma,
i = gFirewire->fw_open_isodma(fc, /* tx */1);
i = gFirewire->fw_open_isodma(fc, /* tx */0);