[PATCH] PHY Layer fixup

This patch adds back the code that was taken out, thus re-enabling:

* The PHY Layer to initialize without crashing
* Drivers to actually connect to PHYs
* The entire PHY Control Layer

This patch is used by the gianfar driver, and other drivers which are in
development.

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

5 files changed, 493 insertions, 102 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 6450bd71deb4..6a2fe3583478 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -12,6 +12,14 @@ config PHYLIB
           devices.  This option provides infrastructure for
           managing PHY devices.
 
+config PHYCONTROL
+        bool "  Support for automatically handling PHY state changes"
+        depends on PHYLIB
+        help
+          Adds code to perform all the work for keeping PHY link
+          state (speed/duplex/etc) up-to-date.  Also handles
+          interrupts.
+
 comment "MII PHY device drivers"
         depends on PHYLIB
 
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index fb7cb385a659..e4116a5fbb4c 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -2,8 +2,9 @@
 
 libphy-objs                     := phy.o phy_device.o mdio_bus.o
 
-obj-$(CONFIG_MARVELL_PHY)       += libphy.o marvell.o
-obj-$(CONFIG_DAVICOM_PHY)       += libphy.o davicom.o
-obj-$(CONFIG_CICADA_PHY)        += libphy.o cicada.o
-obj-$(CONFIG_LXT_PHY)           += libphy.o lxt.o
-obj-$(CONFIG_QSEMI_PHY)         += libphy.o qsemi.o
+obj-$(CONFIG_PHYLIB)            += libphy.o
+obj-$(CONFIG_MARVELL_PHY)       += marvell.o
+obj-$(CONFIG_DAVICOM_PHY)       += davicom.o
+obj-$(CONFIG_CICADA_PHY)        += cicada.o
+obj-$(CONFIG_LXT_PHY)           += lxt.o
+obj-$(CONFIG_QSEMI_PHY)         += qsemi.o
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index d5a05be28818..41f62c0c5fcb 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -38,6 +38,80 @@
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
+/* mdiobus_register 
+ *
+ * description: Called by a bus driver to bring up all the PHYs
+ *   on a given bus, and attach them to the bus
+ */
+int mdiobus_register(struct mii_bus *bus)
+{
+        int i;
+        int err = 0;
+
+        spin_lock_init(&bus->mdio_lock);
+
+        if (NULL == bus || NULL == bus->name ||
+                        NULL == bus->read ||
+                        NULL == bus->write)
+                return -EINVAL;
+
+        if (bus->reset)
+                bus->reset(bus);
+
+        for (i = 0; i < PHY_MAX_ADDR; i++) {
+                struct phy_device *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;
+                        sprintf(phydev->dev.bus_id, "phy%d:%d", bus->id, i);
+
+                        phydev->bus = bus;
+
+                        err = device_register(&phydev->dev);
+
+                        if (err)
+                                printk(KERN_ERR "phy %d failed to register\n",
+                                                i);
+                }
+
+                bus->phy_map[i] = phydev;
+        }
+
+        pr_info("%s: probed\n", bus->name);
+
+        return err;
+}
+EXPORT_SYMBOL(mdiobus_register);
+
+void mdiobus_unregister(struct mii_bus *bus)
+{
+        int i;
+
+        for (i = 0; i < PHY_MAX_ADDR; i++) {
+                if (bus->phy_map[i]) {
+                        device_unregister(&bus->phy_map[i]->dev);
+                        kfree(bus->phy_map[i]);
+                }
+        }
+}
+EXPORT_SYMBOL(mdiobus_unregister);
+
 /* mdio_bus_match
  *
  * description: Given a PHY device, and a PHY driver, return 1 if
@@ -96,4 +170,7 @@ int __init mdio_bus_init(void)
         return bus_register(&mdio_bus_type);
 }
 
-
+void __exit mdio_bus_exit(void)
+{
+        bus_unregister(&mdio_bus_type);
+}
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index d3e43631b89b..d9e11f93bf3a 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -39,10 +39,20 @@
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
-static void phy_timer(unsigned long data);
-static int phy_disable_interrupts(struct phy_device *phydev);
-static void phy_sanitize_settings(struct phy_device *phydev);
-static int phy_stop_interrupts(struct phy_device *phydev);
+/* Convenience function to print out the current phy status
+ */
+void phy_print_status(struct phy_device *phydev)
+{
+        pr_info("%s: Link is %s", phydev->dev.bus_id,
+                        phydev->link ? "Up" : "Down");
+        if (phydev->link)
+                printk(" - %d/%s", phydev->speed,
+                                DUPLEX_FULL == phydev->duplex ?
+                                "Full" : "Half");
+
+        printk("\n");
+}
+EXPORT_SYMBOL(phy_print_status);
 
 
 /* Convenience functions for reading/writing a given PHY
@@ -114,42 +124,6 @@ static inline int phy_aneg_done(struct phy_device *phydev)
         return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
 }
 
-/* phy_start_aneg
- *
- * description: Calls the PHY driver's config_aneg, and then
- *   sets the PHY state to PHY_AN if auto-negotiation is enabled,
- *   and to PHY_FORCING if auto-negotiation is disabled. Unless
- *   the PHY is currently HALTED.
- */
-static int phy_start_aneg(struct phy_device *phydev)
-{
-        int err;
-
-        spin_lock(&phydev->lock);
-
-        if (AUTONEG_DISABLE == phydev->autoneg)
-                phy_sanitize_settings(phydev);
-
-        err = phydev->drv->config_aneg(phydev);
-
-        if (err < 0)
-                goto out_unlock;
-
-        if (phydev->state != PHY_HALTED) {
-                if (AUTONEG_ENABLE == phydev->autoneg) {
-                        phydev->state = PHY_AN;
-                        phydev->link_timeout = PHY_AN_TIMEOUT;
-                } else {
-                        phydev->state = PHY_FORCING;
-                        phydev->link_timeout = PHY_FORCE_TIMEOUT;
-                }
-        }
-
-out_unlock:
-        spin_unlock(&phydev->lock);
-        return err;
-}
-
 /* A structure for mapping a particular speed and duplex
  * combination to a particular SUPPORTED and ADVERTISED value */
 struct phy_setting {
@@ -241,7 +215,7 @@ static inline int phy_find_valid(int idx, u32 features)
  *   duplexes.  Drop down by one in this order:  1000/FULL,
  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF
  */
-static void phy_sanitize_settings(struct phy_device *phydev)
+void phy_sanitize_settings(struct phy_device *phydev)
 {
         u32 features = phydev->supported;
         int idx;
@@ -256,31 +230,7 @@ static void phy_sanitize_settings(struct phy_device *phydev)
         phydev->speed = settings[idx].speed;
         phydev->duplex = settings[idx].duplex;
 }
-
-/* phy_force_reduction
- *
- * description: Reduces the speed/duplex settings by
- *   one notch.  The order is so:
- *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF,
- *   10/FULL, 10/HALF.  The function bottoms out at 10/HALF.
- */
-static void phy_force_reduction(struct phy_device *phydev)
-{
-        int idx;
-
-        idx = phy_find_setting(phydev->speed, phydev->duplex);
-        
-        idx++;
-
-        idx = phy_find_valid(idx, phydev->supported);
-
-        phydev->speed = settings[idx].speed;
-        phydev->duplex = settings[idx].duplex;
-
-        pr_info("Trying %d/%s\n", phydev->speed,
-                        DUPLEX_FULL == phydev->duplex ?
-                        "FULL" : "HALF");
-}
+EXPORT_SYMBOL(phy_sanitize_settings);
 
 /* phy_ethtool_sset:
  * A generic ethtool sset function.  Handles all the details
@@ -291,6 +241,11 @@ static void phy_force_reduction(struct phy_device *phydev)
  * - phy_start_aneg() will make sure forced settings are sane, and
  *   choose the next best ones from the ones selected, so we don't
  *   care if ethtool tries to give us bad values
+ *
+ * A note about the PHYCONTROL Layer.  If you turn off
+ * CONFIG_PHYCONTROL, you will need to read the PHY status
+ * registers after this function completes, and update your
+ * controller manually.
  */
 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 {
@@ -406,6 +361,51 @@ int phy_mii_ioctl(struct phy_device *phydev,
         return 0;
 }
 
+/* phy_start_aneg
+ *
+ * description: Sanitizes the settings (if we're not
+ *   autonegotiating them), and then calls the driver's
+ *   config_aneg function.  If the PHYCONTROL Layer is operating,
+ *   we change the state to reflect the beginning of
+ *   Auto-negotiation or forcing.
+ */
+int phy_start_aneg(struct phy_device *phydev)
+{
+        int err;
+
+        spin_lock(&phydev->lock);
+
+        if (AUTONEG_DISABLE == phydev->autoneg)
+                phy_sanitize_settings(phydev);
+
+        err = phydev->drv->config_aneg(phydev);
+
+#ifdef CONFIG_PHYCONTROL
+        if (err < 0)
+                goto out_unlock;
+
+        if (phydev->state != PHY_HALTED) {
+                if (AUTONEG_ENABLE == phydev->autoneg) {
+                        phydev->state = PHY_AN;
+                        phydev->link_timeout = PHY_AN_TIMEOUT;
+                } else {
+                        phydev->state = PHY_FORCING;
+                        phydev->link_timeout = PHY_FORCE_TIMEOUT;
+                }
+        }
+
+out_unlock:
+#endif
+        spin_unlock(&phydev->lock);
+        return err;
+}
+EXPORT_SYMBOL(phy_start_aneg);
+
+
+#ifdef CONFIG_PHYCONTROL
+static void phy_change(void *data);
+static void phy_timer(unsigned long data);
+
 /* phy_start_machine:
  *
  * description: The PHY infrastructure can run a state machine
@@ -448,6 +448,32 @@ void phy_stop_machine(struct phy_device *phydev)
         phydev->adjust_state = NULL;
 }
 
+/* phy_force_reduction
+ *
+ * description: Reduces the speed/duplex settings by
+ *   one notch.  The order is so:
+ *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF,
+ *   10/FULL, 10/HALF.  The function bottoms out at 10/HALF.
+ */
+static void phy_force_reduction(struct phy_device *phydev)
+{
+        int idx;
+
+        idx = phy_find_setting(phydev->speed, phydev->duplex);
+        
+        idx++;
+
+        idx = phy_find_valid(idx, phydev->supported);
+
+        phydev->speed = settings[idx].speed;
+        phydev->duplex = settings[idx].duplex;
+
+        pr_info("Trying %d/%s\n", phydev->speed,
+                        DUPLEX_FULL == phydev->duplex ?
+                        "FULL" : "HALF");
+}
+
+
 /* phy_error:
  *
  * Moves the PHY to the HALTED state in response to a read
@@ -462,22 +488,44 @@ void phy_error(struct phy_device *phydev)
         spin_unlock(&phydev->lock);
 }
 
-static int phy_stop_interrupts(struct phy_device *phydev)
+/* phy_interrupt
+ *
+ * description: When a PHY interrupt occurs, the handler disables
+ * interrupts, and schedules a work task to clear the interrupt.
+ */
+static irqreturn_t phy_interrupt(int irq, void *phy_dat, struct pt_regs *regs)
+{
+        struct phy_device *phydev = phy_dat;
+
+        /* The MDIO bus is not allowed to be written in interrupt
+         * context, so we need to disable the irq here.  A work
+         * queue will write the PHY to disable and clear the
+         * interrupt, and then reenable the irq line. */
+        disable_irq_nosync(irq);
+
+        schedule_work(&phydev->phy_queue);
+
+        return IRQ_HANDLED;
+}
+
+/* Enable the interrupts from the PHY side */
+int phy_enable_interrupts(struct phy_device *phydev)
 {
         int err;
 
-        err = phy_disable_interrupts(phydev);
+        err = phy_clear_interrupt(phydev);
 
-        if (err)
-                phy_error(phydev);
+        if (err < 0)
+                return err;
 
-        free_irq(phydev->irq, phydev);
+        err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 
         return err;
 }
+EXPORT_SYMBOL(phy_enable_interrupts);
 
 /* Disable the PHY interrupts from the PHY side */
-static int phy_disable_interrupts(struct phy_device *phydev)
+int phy_disable_interrupts(struct phy_device *phydev)
 {
         int err;
 
@@ -500,6 +548,138 @@ phy_err:
 
         return err;
 }
+EXPORT_SYMBOL(phy_disable_interrupts);
+
+/* phy_start_interrupts
+ *
+ * description: Request the interrupt for the given PHY.  If
+ *   this fails, then we set irq to PHY_POLL.
+ *   Otherwise, we enable the interrupts in the PHY.
+ *   Returns 0 on success.
+ *   This should only be called with a valid IRQ number.
+ */
+int phy_start_interrupts(struct phy_device *phydev)
+{
+        int err = 0;
+
+        INIT_WORK(&phydev->phy_queue, phy_change, phydev);
+
+        if (request_irq(phydev->irq, phy_interrupt,
+                                SA_SHIRQ,
+                                "phy_interrupt",
+                                phydev) < 0) {
+                printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
+                                phydev->bus->name,
+                                phydev->irq);
+                phydev->irq = PHY_POLL;
+                return 0;
+        }
+
+        err = phy_enable_interrupts(phydev);
+
+        return err;
+}
+EXPORT_SYMBOL(phy_start_interrupts);
+
+int phy_stop_interrupts(struct phy_device *phydev)
+{
+        int err;
+
+        err = phy_disable_interrupts(phydev);
+
+        if (err)
+                phy_error(phydev);
+
+        free_irq(phydev->irq, phydev);
+
+        return err;
+}
+EXPORT_SYMBOL(phy_stop_interrupts);
+
+
+/* Scheduled by the phy_interrupt/timer to handle PHY changes */
+static void phy_change(void *data)
+{
+        int err;
+        struct phy_device *phydev = data;
+
+        err = phy_disable_interrupts(phydev);
+
+        if (err)
+                goto phy_err;
+
+        spin_lock(&phydev->lock);
+        if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
+                phydev->state = PHY_CHANGELINK;
+        spin_unlock(&phydev->lock);
+
+        enable_irq(phydev->irq);
+
+        /* Reenable interrupts */
+        err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
+
+        if (err)
+                goto irq_enable_err;
+
+        return;
+
+irq_enable_err:
+        disable_irq(phydev->irq);
+phy_err:
+        phy_error(phydev);
+}
+
+/* Bring down the PHY link, and stop checking the status. */
+void phy_stop(struct phy_device *phydev)
+{
+        spin_lock(&phydev->lock);
+
+        if (PHY_HALTED == phydev->state)
+                goto out_unlock;
+
+        if (phydev->irq != PHY_POLL) {
+                /* Clear any pending interrupts */
+                phy_clear_interrupt(phydev);
+
+                /* Disable PHY Interrupts */
+                phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
+        }
+
+        phydev->state = PHY_HALTED;
+
+out_unlock:
+        spin_unlock(&phydev->lock);
+}
+
+
+/* phy_start
+ *
+ * description: Indicates the attached device's readiness to
+ *   handle PHY-related work.  Used during startup to start the
+ *   PHY, and after a call to phy_stop() to resume operation.
+ *   Also used to indicate the MDIO bus has cleared an error
+ *   condition.
+ */
+void phy_start(struct phy_device *phydev)
+{
+        spin_lock(&phydev->lock);
+
+        switch (phydev->state) {
+                case PHY_STARTING:
+                        phydev->state = PHY_PENDING;
+                        break;
+                case PHY_READY:
+                        phydev->state = PHY_UP;
+                        break;
+                case PHY_HALTED:
+                        phydev->state = PHY_RESUMING;
+                default:
+                        break;
+        }
+        spin_unlock(&phydev->lock);
+}
+EXPORT_SYMBOL(phy_stop);
+EXPORT_SYMBOL(phy_start);
 
 /* PHY timer which handles the state machine */
 static void phy_timer(unsigned long data)
@@ -688,3 +868,4 @@ static void phy_timer(unsigned long data)
         mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
 }
 
+#endif /* CONFIG_PHYCONTROL */
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index c44d54f6310a..33f7bdb5857c 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -39,18 +39,9 @@
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
-static int genphy_config_init(struct phy_device *phydev);
-
-static struct phy_driver genphy_driver = {
-        .phy_id         = 0xffffffff,
-        .phy_id_mask    = 0xffffffff,
-        .name           = "Generic PHY",
-        .config_init    = genphy_config_init,
-        .features       = 0,
-        .config_aneg    = genphy_config_aneg,
-        .read_status    = genphy_read_status,
-        .driver =       {.owner = THIS_MODULE, },
-};
+static struct phy_driver genphy_driver;
+extern int mdio_bus_init(void);
+extern void mdio_bus_exit(void);
 
 /* get_phy_device
  *
@@ -110,6 +101,7 @@ struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
         return dev;
 }
 
+#ifdef CONFIG_PHYCONTROL
 /* phy_prepare_link:
  *
  * description: Tells the PHY infrastructure to handle the
@@ -124,6 +116,132 @@ void phy_prepare_link(struct phy_device *phydev,
         phydev->adjust_link = handler;
 }
 
+/* phy_connect:
+ *
+ * description: Convenience function for connecting ethernet
+ *   devices to PHY devices.  The default behavior is for
+ *   the PHY infrastructure to handle everything, and only notify
+ *   the connected driver when the link status changes.  If you
+ *   don't want, or can't use the provided functionality, you may
+ *   choose to call only the subset of functions which provide
+ *   the desired functionality.
+ */
+struct phy_device * phy_connect(struct net_device *dev, const char *phy_id,
+                void (*handler)(struct net_device *), u32 flags)
+{
+        struct phy_device *phydev;
+
+        phydev = phy_attach(dev, phy_id, flags);
+
+        if (IS_ERR(phydev))
+                return phydev;
+
+        phy_prepare_link(phydev, handler);
+
+        phy_start_machine(phydev, NULL);
+
+        if (phydev->irq > 0)
+                phy_start_interrupts(phydev);
+
+        return phydev;
+}
+EXPORT_SYMBOL(phy_connect);
+
+void phy_disconnect(struct phy_device *phydev)
+{
+        if (phydev->irq > 0)
+                phy_stop_interrupts(phydev);
+
+        phy_stop_machine(phydev);
+        
+        phydev->adjust_link = NULL;
+
+        phy_detach(phydev);
+}
+EXPORT_SYMBOL(phy_disconnect);
+
+#endif /* CONFIG_PHYCONTROL */
+
+/* phy_attach:
+ *
+ *   description: Called by drivers to attach to a particular PHY
+ *     device. The phy_device is found, and properly hooked up
+ *     to the phy_driver.  If no driver is attached, then the
+ *     genphy_driver is used.  The phy_device is given a ptr to
+ *     the attaching device, and given a callback for link status
+ *     change.  The phy_device is returned to the attaching
+ *     driver.
+ */
+static int phy_compare_id(struct device *dev, void *data)
+{
+        return strcmp((char *)data, dev->bus_id) ? 0 : 1;
+}
+
+struct phy_device *phy_attach(struct net_device *dev,
+                const char *phy_id, u32 flags)
+{
+        struct bus_type *bus = &mdio_bus_type;
+        struct phy_device *phydev;
+        struct device *d;
+
+        /* Search the list of PHY devices on the mdio bus for the
+         * PHY with the requested name */
+        d = bus_find_device(bus, NULL, (void *)phy_id, phy_compare_id);
+
+        if (d) {
+                phydev = to_phy_device(d);
+        } else {
+                printk(KERN_ERR "%s not found\n", phy_id);
+                return ERR_PTR(-ENODEV);
+        }
+
+        /* Assume that if there is no driver, that it doesn't
+         * exist, and we should use the genphy driver. */
+        if (NULL == d->driver) {
+                int err;
+                down_write(&d->bus->subsys.rwsem);
+                d->driver = &genphy_driver.driver;
+
+                err = d->driver->probe(d);
+
+                if (err < 0)
+                        return ERR_PTR(err);
+
+                device_bind_driver(d);
+                up_write(&d->bus->subsys.rwsem);
+        }
+
+        if (phydev->attached_dev) {
+                printk(KERN_ERR "%s: %s already attached\n",
+                                dev->name, phy_id);
+                return ERR_PTR(-EBUSY);
+        }
+
+        phydev->attached_dev = dev;
+
+        phydev->dev_flags = flags;
+
+        return phydev;
+}
+EXPORT_SYMBOL(phy_attach);
+
+void phy_detach(struct phy_device *phydev)
+{
+        phydev->attached_dev = NULL;
+
+        /* If the device had no specific driver before (i.e. - it
+         * was using the generic driver), we unbind the device
+         * from the generic driver so that there's a chance a
+         * real driver could be loaded */
+        if (phydev->dev.driver == &genphy_driver.driver) {
+                down_write(&phydev->dev.bus->subsys.rwsem);
+                device_release_driver(&phydev->dev);
+                up_write(&phydev->dev.bus->subsys.rwsem);
+        }
+}
+EXPORT_SYMBOL(phy_detach);
+
+
 /* Generic PHY support and helper functions */
 
 /* genphy_config_advert
@@ -132,7 +250,7 @@ void phy_prepare_link(struct phy_device *phydev,
  *   after sanitizing the values to make sure we only advertise
  *   what is supported
  */
-static int genphy_config_advert(struct phy_device *phydev)
+int genphy_config_advert(struct phy_device *phydev)
 {
         u32 advertise;
         int adv;
@@ -190,6 +308,7 @@ static int genphy_config_advert(struct phy_device *phydev)
 
         return adv;
 }
+EXPORT_SYMBOL(genphy_config_advert);
 
 /* genphy_setup_forced
  *
@@ -541,32 +660,37 @@ void phy_driver_unregister(struct phy_driver *drv)
 }
 EXPORT_SYMBOL(phy_driver_unregister);
 
+static struct phy_driver genphy_driver = {
+        .phy_id         = 0xffffffff,
+        .phy_id_mask    = 0xffffffff,
+        .name           = "Generic PHY",
+        .config_init    = genphy_config_init,
+        .features       = 0,
+        .config_aneg    = genphy_config_aneg,
+        .read_status    = genphy_read_status,
+        .driver         = {.owner= THIS_MODULE, },
+};
 
 static int __init phy_init(void)
 {
         int rc;
-        extern int mdio_bus_init(void);
-
-        rc = phy_driver_register(&genphy_driver);
-        if (rc)
-                goto out;
 
         rc = mdio_bus_init();
         if (rc)
-                goto out_unreg;
+                return rc;
 
-        return 0;
+        rc = phy_driver_register(&genphy_driver);
+        if (rc)
+                mdio_bus_exit();
 
-out_unreg:
-        phy_driver_unregister(&genphy_driver);
-out:
         return rc;
 }
 
 static void __exit phy_exit(void)
 {
         phy_driver_unregister(&genphy_driver);
+        mdio_bus_exit();
 }
 
-module_init(phy_init);
+subsys_initcall(phy_init);
 module_exit(phy_exit);