net: fixed-phy: Add fixed_phy_register_with_gpiod() API

Add fixed_phy_register_with_gpiod() API. It lets users create a
fixed_phy instance that uses a GPIO descriptor which was obtained
externally e.g. through platform data.
This enables platform devices (non-DT based) to use GPIOs for link
status.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index d810f91..b0d1368c3 100644
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -229,12 +229,12 @@ static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
 }
 #endif
 
-struct phy_device *fixed_phy_register(unsigned int irq,
-				      struct fixed_phy_status *status,
-				      struct device_node *np)
+static struct phy_device *__fixed_phy_register(unsigned int irq,
+					       struct fixed_phy_status *status,
+					       struct device_node *np,
+					       struct gpio_desc *gpiod)
 {
 	struct fixed_mdio_bus *fmb = &platform_fmb;
-	struct gpio_desc *gpiod = NULL;
 	struct phy_device *phy;
 	int phy_addr;
 	int ret;
@@ -243,9 +243,11 @@ struct phy_device *fixed_phy_register(unsigned int irq,
 		return ERR_PTR(-EPROBE_DEFER);
 
 	/* Check if we have a GPIO associated with this fixed phy */
-	gpiod = fixed_phy_get_gpiod(np);
-	if (IS_ERR(gpiod))
-		return ERR_CAST(gpiod);
+	if (!gpiod) {
+		gpiod = fixed_phy_get_gpiod(np);
+		if (IS_ERR(gpiod))
+			return ERR_CAST(gpiod);
+	}
 
 	/* Get the next available PHY address, up to PHY_MAX_ADDR */
 	phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
@@ -308,8 +310,24 @@ struct phy_device *fixed_phy_register(unsigned int irq,
 
 	return phy;
 }
+
+struct phy_device *fixed_phy_register(unsigned int irq,
+				      struct fixed_phy_status *status,
+				      struct device_node *np)
+{
+	return __fixed_phy_register(irq, status, np, NULL);
+}
 EXPORT_SYMBOL_GPL(fixed_phy_register);
 
+struct phy_device *
+fixed_phy_register_with_gpiod(unsigned int irq,
+			      struct fixed_phy_status *status,
+			      struct gpio_desc *gpiod)
+{
+	return __fixed_phy_register(irq, status, NULL, gpiod);
+}
+EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
+
 void fixed_phy_unregister(struct phy_device *phy)
 {
 	phy_device_remove(phy);
diff --git a/include/linux/phy_fixed.h b/include/linux/phy_fixed.h
index c78fc20..1e5d86e 100644
--- a/include/linux/phy_fixed.h
+++ b/include/linux/phy_fixed.h
@@ -19,6 +19,12 @@ extern int fixed_phy_add(unsigned int irq, int phy_id,
 extern struct phy_device *fixed_phy_register(unsigned int irq,
 					     struct fixed_phy_status *status,
 					     struct device_node *np);
+
+extern struct phy_device *
+fixed_phy_register_with_gpiod(unsigned int irq,
+			      struct fixed_phy_status *status,
+			      struct gpio_desc *gpiod);
+
 extern void fixed_phy_unregister(struct phy_device *phydev);
 extern int fixed_phy_set_link_update(struct phy_device *phydev,
 			int (*link_update)(struct net_device *,
@@ -35,6 +41,15 @@ static inline struct phy_device *fixed_phy_register(unsigned int irq,
 {
 	return ERR_PTR(-ENODEV);
 }
+
+static inline struct phy_device *
+fixed_phy_register_with_gpiod(unsigned int irq,
+			      struct fixed_phy_status *status,
+			      struct gpio_desc *gpiod)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void fixed_phy_unregister(struct phy_device *phydev)
 {
 }