MPC52xx_PSC_IMR_RXRDY
out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
& MPC52xx_PSC_IMR_RXRDY;
port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;