phylib: factor out get_phy_id from within get_phy_device

We were already doing what amounts to a get_phy_id from within
get_phy_device, and rather than duplicate this for the TBIPA
probing, we might as well just factor it out and make it available
instead.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/phy/phy_device.c

@@ -86,35 +86,55 @@ struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
 EXPORT_SYMBOL(phy_device_create);
 
 /**
- * get_phy_device - reads the specified PHY device and returns its @phy_device struct
+ * get_phy_id - reads the specified addr for its ID.
  * @bus: the target MII bus
  * @addr: PHY address on the MII bus
+ * @phy_id: where to store the ID retrieved.
  *
  * Description: Reads the ID registers of the PHY at @addr on the
- *   @bus, then allocates and returns the phy_device to represent it.
+ *   @bus, stores it in @phy_id and returns zero on success.
  */
-struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
+int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id)
 {
 	int phy_reg;
-	u32 phy_id;
-	struct phy_device *dev = NULL;
 
 	/* Grab the bits from PHYIR1, and put them
 	 * in the upper half */
 	phy_reg = bus->read(bus, addr, MII_PHYSID1);
 
 	if (phy_reg < 0)
-		return ERR_PTR(phy_reg);
+		return -EIO;
 
-	phy_id = (phy_reg & 0xffff) << 16;
+	*phy_id = (phy_reg & 0xffff) << 16;
 
 	/* Grab the bits from PHYIR2, and put them in the lower half */
 	phy_reg = bus->read(bus, addr, MII_PHYSID2);
 
 	if (phy_reg < 0)
-		return ERR_PTR(phy_reg);
+		return -EIO;
+
+	*phy_id |= (phy_reg & 0xffff);
+
+	return 0;
+}
+
+/**
+ * get_phy_device - reads the specified PHY device and returns its @phy_device struct
+ * @bus: the target MII bus
+ * @addr: PHY address on the MII bus
+ *
+ * Description: Reads the ID registers of the PHY at @addr on the
+ *   @bus, then allocates and returns the phy_device to represent it.
+ */
+struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
+{
+	struct phy_device *dev = NULL;
+	u32 phy_id;
+	int r;
 
-	phy_id |= (phy_reg & 0xffff);
+	r = get_phy_id(bus, addr, &phy_id);
+	if (r)
+		return ERR_PTR(r);
 
 	/* If the phy_id is all Fs, there is no device there */
 	if (0xffffffff == phy_id)

include/linux/phy.h

@@ -381,6 +381,7 @@ struct phy_driver {
 
 int phy_read(struct phy_device *phydev, u16 regnum);
 int phy_write(struct phy_device *phydev, u16 regnum, u16 val);
+int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id);
 struct phy_device* get_phy_device(struct mii_bus *bus, int addr);
 int phy_clear_interrupt(struct phy_device *phydev);
 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts);