TDR
ADM8211_CSR_WRITE(TDR, 0);
__le32 TDR; /* 0x08 CSR1 */
spi_writel(as, TDR, DUMMY_MSG);
spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
spi_writel(as, TDR, (td1 << 16) | td0);
spi_writew(as, TDR, td0);
rsci_serial_out(port, TDR, c);
rsci_serial_out(port, TDR, c);
wr_reg16(info, TDR, 0);