pps_ioctl
error = pps_ioctl(cmd, data, &sc->sc_pps);
return (pps_ioctl(ap->a_cmd, ap->a_data, &sc->pps));
error = pps_ioctl(ap->a_cmd, data, &com->pps);
int pps_ioctl (u_long cmd, caddr_t data, struct pps_state *pps);