cd1400_compute_baud
cd1400_compute_baud(t->c_ospeed, cd->cd_clock, &tcor, &tbpr))
cd1400_compute_baud(t->c_ispeed, cd->cd_clock, &rcor, &rbpr))
cd1400_compute_baud(100000, cd->cd_clock, &rcor, &rbpr);
int cd1400_compute_baud(speed_t, int, int *, int *);