phylib: allow incremental scanning of an mii bus

This patch splits the bus scanning code in mdiobus_register() off
into a separate function, and makes this function available for
calling from external code.  This allows incrementally scanning an
mii bus, e.g. as information about which addresses are 'safe' to
scan becomes available.

Signed-off-by: Lennert Buytenhek <[email protected]>
Acked-by: Andy Fleming <[email protected]>

Author: buytenh

drivers/net/phy/mdio_bus.c

@@ -60,49 +60,14 @@ int mdiobus_register(struct mii_bus *bus)
 		bus->reset(bus);
 
 	for (i = 0; i < PHY_MAX_ADDR; i++) {
-		struct phy_device *phydev;
+		bus->phy_map[i] = NULL;
+		if ((bus->phy_mask & (1 << i)) == 0) {
+			struct phy_device *phydev;
 
-		if (bus->phy_mask & (1 << i)) {
-			bus->phy_map[i] = NULL;
-			continue;
+			phydev = mdiobus_scan(bus, i);
+			if (IS_ERR(phydev))
+				err = PTR_ERR(phydev);
 		}
-
-		phydev = get_phy_device(bus, i);
-
-		if (IS_ERR(phydev))
-			return PTR_ERR(phydev);
-
-		/* There's a PHY at this address
-		 * We need to set:
-		 * 1) IRQ
-		 * 2) bus_id
-		 * 3) parent
-		 * 4) bus
-		 * 5) mii_bus
-		 * And, we need to register it */
-		if (phydev) {
-			phydev->irq = bus->irq[i];
-
-			phydev->dev.parent = bus->dev;
-			phydev->dev.bus = &mdio_bus_type;
-			snprintf(phydev->dev.bus_id, BUS_ID_SIZE, PHY_ID_FMT, bus->id, i);
-
-			phydev->bus = bus;
-
-			/* Run all of the fixups for this PHY */
-			phy_scan_fixups(phydev);
-
-			err = device_register(&phydev->dev);
-
-			if (err) {
-				printk(KERN_ERR "phy %d failed to register\n",
-						i);
-				phy_device_free(phydev);
-				phydev = NULL;
-			}
-		}
-
-		bus->phy_map[i] = phydev;
 	}
 
 	pr_info("%s: probed\n", bus->name);
@@ -122,6 +87,48 @@ void mdiobus_unregister(struct mii_bus *bus)
 }
 EXPORT_SYMBOL(mdiobus_unregister);
 
+struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
+{
+	struct phy_device *phydev;
+	int err;
+
+	phydev = get_phy_device(bus, addr);
+	if (IS_ERR(phydev) || phydev == NULL)
+		return phydev;
+
+	/* There's a PHY at this address
+	 * We need to set:
+	 * 1) IRQ
+	 * 2) bus_id
+	 * 3) parent
+	 * 4) bus
+	 * 5) mii_bus
+	 * And, we need to register it */
+
+	phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
+
+	phydev->dev.parent = bus->dev;
+	phydev->dev.bus = &mdio_bus_type;
+	snprintf(phydev->dev.bus_id, BUS_ID_SIZE, PHY_ID_FMT, bus->id, addr);
+
+	phydev->bus = bus;
+
+	/* Run all of the fixups for this PHY */
+	phy_scan_fixups(phydev);
+
+	err = device_register(&phydev->dev);
+	if (err) {
+		printk(KERN_ERR "phy %d failed to register\n", addr);
+		phy_device_free(phydev);
+		phydev = NULL;
+	}
+
+	bus->phy_map[addr] = phydev;
+
+	return phydev;
+}
+EXPORT_SYMBOL(mdiobus_scan);
+
 /**
  * mdio_bus_match - determine if given PHY driver supports the given PHY device
  * @dev: target PHY device

include/linux/phy.h

@@ -410,6 +410,8 @@ int phy_start_aneg(struct phy_device *phydev);
 
 int mdiobus_register(struct mii_bus *bus);
 void mdiobus_unregister(struct mii_bus *bus);
+struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
+
 void phy_sanitize_settings(struct phy_device *phydev);
 int phy_stop_interrupts(struct phy_device *phydev);
 int phy_enable_interrupts(struct phy_device *phydev);