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:
		This attribute contains the boolean value whether a given PHY
		device has had any "fixup" workaround running on it, encoded as
		a boolean. This information is provided to help troubleshooting
		PHY configurations.

What:		/sys/class/mdio_bus/<bus>/<device>/phy_id
Date:		November 2012
KernelVersion:	3.8
Contact:	netdev@vger.kernel.org
Description:
		This attribute contains the 32-bit PHY Identifier as reported
		by the device during bus enumeration, encoded in hexadecimal.
		This ID is used to match the device with the appropriate
		driver.

What:		/sys/class/mdio_bus/<bus>/<device>/phy_interface
Date:		February 2014
KernelVersion:	3.15
Contact:	netdev@vger.kernel.org
Description:
		This attribute contains the PHY interface as configured by the
		Ethernet driver during bus enumeration, encoded in string.
		This interface mode is used to configure the Ethernet MAC with the
		appropriate mode for its data lines to the PHY hardware.
		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

What:		/sys/class/mdio_bus/<bus>/<device>/phy_standalone
Date:		May 2019
KernelVersion:	5.3
Contact:	netdev@vger.kernel.org
Description:
		Boolean value indicating whether the PHY device is used in
		standalone mode, without a net_device associated, by PHYLINK.
		Attribute created only when this is the case.