mdio_bus: Add comment to mdiobus_scan() and __mdiobus_register()
Make it clear that mdiobus_scan () will only find devices which have a
vendor/product ID in registers 2 and 3. These are typically PHY
devices. Other sort of MDIO devices, such as switches, are not
expected to be found during the scan.
Similarly, __mdiobus_register(), which calls mdiobus_scan() will only
find PHY devices, and other sorts of MDIO devices are expected to be
instantiated from device tree.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 0d369ad..6f9ca51 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -291,7 +291,9 @@
* 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.
*/
@@ -394,6 +396,18 @@
}
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;