What:		/sys/class/mdio_bus/<bus>/<device>/attached_dev
Date:		May 2017
KernelVersion:	4.13
Contact:	netdev@vger.kernel.org
Description:
		Symbolic link to the network device this PHY device is
		attached to.

What:		/sys/class/mdio_bus/<bus>/<device>/phy_has_fixups
Date:		February 2014
KernelVersion:	3.15
Contact:	netdev@vger.kernel.org
Description:
		Boolean value indicating whether the PHY device has
		any fixups registered against it (phy_register_fixup)

What:		/sys/class/mdio_bus/<bus>/<device>/phy_id
Date:		November 2012
KernelVersion:	3.8
Contact:	netdev@vger.kernel.org
Description:
		32-bit hexadecimal value corresponding to the PHY device's OUI,
		model and revision number.

What:		/sys/class/mdio_bus/<bus>/<device>/phy_interface
Date:		February 2014
KernelVersion:	3.15
Contact:	netdev@vger.kernel.org
Description:
		String value indicating the PHY interface, possible
		values are:.
		<empty> (not available), mii, gmii, sgmii, tbi, rev-mii,
		rmii, rgmii, rgmii-id, rgmii-rxid, rgmii-txid, rtbi, smii
		xgmii, moca, qsgmii, trgmii, 1000base-x, 2500base-x, rxaui,
		xaui, 10gbase-kr, unknown

