mdio_bus: Add comment to mdiobus_scan() and __mdiobus_register()

 * Description: Called by a bus driver to bring up all the PHYs

 *   on a given bus, and attach them to the bus. Drivers should use

 *   mdiobus_register() rather than __mdiobus_register() unless they

 *   need to pass a specific owner module.

 *   need to pass a specific owner module. MDIO devices which are not

 *   PHYs will not be brought up by this function. They are expected to

 *   to be explicitly listed in DT and instantiated by of_mdiobus_register().

 *

 * Returns 0 on success or < 0 on error.

 */

}

EXPORT_SYMBOL(mdiobus_free);

/**

 * mdiobus_scan - scan a bus for MDIO devices.

 * @bus: mii_bus to scan

 * @addr: address on bus to scan

 *

 * This function scans the MDIO bus, looking for devices which can be

 * identified using a vendor/product ID in registers 2 and 3. Not all

 * MDIO devices have such registers, but PHY devices typically

 * do. Hence this function assumes anything found is a PHY, or can be

 * treated as a PHY. Other MDIO devices, such as switches, will

 * probably not be found during the scan.

 */

struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)

{

	struct phy_device *phydev;