pl011_maybe_set_bit
pl011_maybe_set_bit(status & UART01x_FR_DCD, &result, TIOCM_CAR);
pl011_maybe_set_bit(status & uap->vendor->fr_dsr, &result, TIOCM_DSR);
pl011_maybe_set_bit(status & uap->vendor->fr_cts, &result, TIOCM_CTS);
pl011_maybe_set_bit(status & uap->vendor->fr_ri, &result, TIOCM_RNG);