net: phy: adjust fixed_phy_register() return value

Adjust fixed_phy_register() to return struct phy_device *, so that
it becomes easy to use fixed PHYs without device tree support:

  phydev = fixed_phy_register(PHY_POLL, &fixed_phy_status, NULL);
  fixed_phy_set_link_update(phydev, fixed_phy_link_update);
  phy_connect_direct(netdev, phydev, handler_fn, phy_interface);

This change is a prerequisite for modifying bcmgenet driver to work
without a device tree on Broadcom's MIPS-based 7xxx platforms.
Signed-off-by: Petri Gynther <pgynther@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/fixed.c

@@ -233,7 +233,7 @@ EXPORT_SYMBOL_GPL(fixed_phy_del);
 static int phy_fixed_addr;
 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 
-int fixed_phy_register(unsigned int irq,
+struct phy_device *fixed_phy_register(unsigned int irq,
 				      struct fixed_phy_status *status,
 				      struct device_node *np)
 {
@@ -246,19 +246,19 @@ int fixed_phy_register(unsigned int irq,
 	spin_lock(&phy_fixed_addr_lock);
 	if (phy_fixed_addr == PHY_MAX_ADDR) {
 		spin_unlock(&phy_fixed_addr_lock);
-		return -ENOSPC;
+		return ERR_PTR(-ENOSPC);
 	}
 	phy_addr = phy_fixed_addr++;
 	spin_unlock(&phy_fixed_addr_lock);
 
 	ret = fixed_phy_add(PHY_POLL, phy_addr, status);
 	if (ret < 0)
-		return ret;
+		return ERR_PTR(ret);
 
 	phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 	if (!phy || IS_ERR(phy)) {
 		fixed_phy_del(phy_addr);
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	of_node_get(np);
@@ -269,10 +269,10 @@ int fixed_phy_register(unsigned int irq,
 		phy_device_free(phy);
 		of_node_put(np);
 		fixed_phy_del(phy_addr);
-		return ret;
+		return ERR_PTR(ret);
 	}
 
-	return 0;
+	return phy;
 }
 
 static int __init fixed_mdio_bus_init(void)

drivers/of/of_mdio.c

@@ -286,6 +286,7 @@ int of_phy_register_fixed_link(struct device_node *np)
 	struct device_node *fixed_link_node;
 	const __be32 *fixed_link_prop;
 	int len;
+	struct phy_device *phy;
 
 	/* New binding */
 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
@@ -299,7 +300,8 @@ int of_phy_register_fixed_link(struct device_node *np)
 		status.asym_pause = of_property_read_bool(fixed_link_node,
 							  "asym-pause");
 		of_node_put(fixed_link_node);
-		return fixed_phy_register(PHY_POLL, &status, np);
+		phy = fixed_phy_register(PHY_POLL, &status, np);
+		return IS_ERR(phy) ? PTR_ERR(phy) : 0;
 	}
 
 	/* Old binding */
@@ -310,7 +312,8 @@ int of_phy_register_fixed_link(struct device_node *np)
 		status.speed = be32_to_cpu(fixed_link_prop[2]);
 		status.pause = be32_to_cpu(fixed_link_prop[3]);
 		status.asym_pause = be32_to_cpu(fixed_link_prop[4]);
-		return fixed_phy_register(PHY_POLL, &status, np);
+		phy = fixed_phy_register(PHY_POLL, &status, np);
+		return IS_ERR(phy) ? PTR_ERR(phy) : 0;
 	}
 
 	return -ENODEV;

include/linux/phy_fixed.h

@@ -14,7 +14,7 @@ struct device_node;
 #ifdef CONFIG_FIXED_PHY
 extern int fixed_phy_add(unsigned int irq, int phy_id,
 			 struct fixed_phy_status *status);
-extern int fixed_phy_register(unsigned int irq,
+extern struct phy_device *fixed_phy_register(unsigned int irq,
 					     struct fixed_phy_status *status,
 					     struct device_node *np);
 extern void fixed_phy_del(int phy_addr);
@@ -27,11 +27,11 @@ static inline int fixed_phy_add(unsigned int irq, int phy_id,
 {
 	return -ENODEV;
 }
-static inline int fixed_phy_register(unsigned int irq,
+static inline struct phy_device *fixed_phy_register(unsigned int irq,
 						struct fixed_phy_status *status,
 						struct device_node *np)
 {
-	return -ENODEV;
+	return ERR_PTR(-ENODEV);
 }
 static inline int fixed_phy_del(int phy_addr)
 {