MAC_CON0_GMAC2IO_TX_DL_CFG_MASK
tx = ((reg >> MAC_CON0_GMAC2IO_TX_DL_CFG_SHIFT) & MAC_CON0_GMAC2IO_TX_DL_CFG_MASK);
reg |= ((sc->tx_delay & MAC_CON0_GMAC2IO_TX_DL_CFG_MASK) <<
reg |= ((sc->rx_delay & MAC_CON0_GMAC2IO_TX_DL_CFG_MASK) <<