net: phy: fixed-phy: Drop GPIO from fixed_phy_add()

All users of the fixed_phy_add() pass -1 as GPIO number
to the fixed phy driver, and all users of fixed_phy_register()
pass -1 as GPIO number as well, except for the device
tree MDIO bus.

Any new users should create a proper device and pass the
GPIO as a descriptor associated with the device so delete
the GPIO argument from the calls and drop the code looking
requesting a GPIO in fixed_phy_add().

In fixed phy_register(), investigate the "fixed-link"
node and pick the GPIO descriptor from "link-gpios" if
this property exists. Move the corresponding code out
of of_mdio.c as the fixed phy code anyways requires
OF to be in use.

Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/fixed_phy.c

@@ -18,7 +18,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/of.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/seqlock.h>
 #include <linux/idr.h>
 #include <linux/netdevice.h>
@@ -38,7 +38,7 @@ struct fixed_phy {
 	bool no_carrier;
 	int (*link_update)(struct net_device *, struct fixed_phy_status *);
 	struct list_head node;
-	int link_gpio;
+	struct gpio_desc *link_gpiod;
 };
 
 static struct platform_device *pdev;
@@ -67,8 +67,8 @@ EXPORT_SYMBOL_GPL(fixed_phy_change_carrier);
 
 static void fixed_phy_update(struct fixed_phy *fp)
 {
-	if (!fp->no_carrier && gpio_is_valid(fp->link_gpio))
-		fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
+	if (!fp->no_carrier && fp->link_gpiod)
+		fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod);
 }
 
 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
@@ -133,9 +133,9 @@ int fixed_phy_set_link_update(struct phy_device *phydev,
 }
 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 
-int fixed_phy_add(unsigned int irq, int phy_addr,
-		  struct fixed_phy_status *status,
-		  int link_gpio)
+static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr,
+			       struct fixed_phy_status *status,
+			       struct gpio_desc *gpiod)
 {
 	int ret;
 	struct fixed_mdio_bus *fmb = &platform_fmb;
@@ -156,24 +156,19 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
 
 	fp->addr = phy_addr;
 	fp->status = *status;
-	fp->link_gpio = link_gpio;
-
-	if (gpio_is_valid(fp->link_gpio)) {
-		ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
-				       "fixed-link-gpio-link");
-		if (ret)
-			goto err_regs;
-	}
+	fp->link_gpiod = gpiod;
 
 	fixed_phy_update(fp);
 
 	list_add_tail(&fp->node, &fmb->phys);
 
 	return 0;
+}
 
-err_regs:
-	kfree(fp);
-	return ret;
+int fixed_phy_add(unsigned int irq, int phy_addr,
+		  struct fixed_phy_status *status) {
+
+	return fixed_phy_add_gpiod(irq, phy_addr, status, NULL);
 }
 EXPORT_SYMBOL_GPL(fixed_phy_add);
 
@@ -187,8 +182,8 @@ static void fixed_phy_del(int phy_addr)
 	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 		if (fp->addr == phy_addr) {
 			list_del(&fp->node);
-			if (gpio_is_valid(fp->link_gpio))
-				gpio_free(fp->link_gpio);
+			if (fp->link_gpiod)
+				gpiod_put(fp->link_gpiod);
 			kfree(fp);
 			ida_simple_remove(&phy_fixed_ida, phy_addr);
 			return;
@@ -196,12 +191,50 @@ static void fixed_phy_del(int phy_addr)
 	}
 }
 
+#ifdef CONFIG_OF_GPIO
+static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
+{
+	struct device_node *fixed_link_node;
+	struct gpio_desc *gpiod;
+
+	if (!np)
+		return NULL;
+
+	fixed_link_node = of_get_child_by_name(np, "fixed-link");
+	if (!fixed_link_node)
+		return NULL;
+
+	/*
+	 * As the fixed link is just a device tree node without any
+	 * Linux device associated with it, we simply have obtain
+	 * the GPIO descriptor from the device tree like this.
+	 */
+	gpiod = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0,
+				       GPIOD_IN, "mdio");
+	of_node_put(fixed_link_node);
+	if (IS_ERR(gpiod)) {
+		if (PTR_ERR(gpiod) == -EPROBE_DEFER)
+			return gpiod;
+		pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
+		       fixed_link_node);
+		gpiod = NULL;
+	}
+
+	return gpiod;
+}
+#else
+static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
+{
+	return NULL;
+}
+#endif
+
 struct phy_device *fixed_phy_register(unsigned int irq,
 				      struct fixed_phy_status *status,
-				      int link_gpio,
 				      struct device_node *np)
 {
 	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct gpio_desc *gpiod = NULL;
 	struct phy_device *phy;
 	int phy_addr;
 	int ret;
@@ -209,12 +242,17 @@ struct phy_device *fixed_phy_register(unsigned int irq,
 	if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
 		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);
+
 	/* 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);
 	if (phy_addr < 0)
 		return ERR_PTR(phy_addr);
 
-	ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
+	ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
 	if (ret < 0) {
 		ida_simple_remove(&phy_fixed_ida, phy_addr);
 		return ERR_PTR(ret);