MDIO_PHY_ID_PRTAD 98 include/linux/mdio.h return (phy_id & MDIO_PHY_ID_PRTAD) >> 5; MDIO_PHY_ID_PRTAD 320 include/uapi/linux/mdio.h (MDIO_PHY_ID_C45 | MDIO_PHY_ID_PRTAD | MDIO_PHY_ID_DEVAD)