SPRD_STS1
if (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
while ((serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) &&
while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK)
while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
while (!(serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK))
while (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
status = serial_in(port, SPRD_STS1);