v4.19.13 snapshot.
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
new file mode 100644
index 0000000..98f4b1f
--- /dev/null
+++ b/drivers/net/phy/mdio_bus.c
@@ -0,0 +1,754 @@
+/* MDIO Bus interface
+ *
+ * Author: Andy Fleming
+ *
+ * Copyright (c) 2004 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/of_gpio.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/ethtool.h>
+#include <linux/phy.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/gpio/consumer.h>
+
+#include <asm/irq.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/mdio.h>
+
+#include "mdio-boardinfo.h"
+
+static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
+{
+ struct gpio_desc *gpiod = NULL;
+
+ /* Deassert the optional reset signal */
+ if (mdiodev->dev.of_node)
+ gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
+ "reset-gpios", 0, GPIOD_OUT_LOW,
+ "PHY reset");
+ if (PTR_ERR(gpiod) == -ENOENT ||
+ PTR_ERR(gpiod) == -ENOSYS)
+ gpiod = NULL;
+ else if (IS_ERR(gpiod))
+ return PTR_ERR(gpiod);
+
+ mdiodev->reset = gpiod;
+
+ /* Assert the reset signal again */
+ mdio_device_reset(mdiodev, 1);
+
+ return 0;
+}
+
+int mdiobus_register_device(struct mdio_device *mdiodev)
+{
+ int err;
+
+ if (mdiodev->bus->mdio_map[mdiodev->addr])
+ return -EBUSY;
+
+ if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
+ err = mdiobus_register_gpiod(mdiodev);
+ if (err)
+ return err;
+ }
+
+ mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
+
+ return 0;
+}
+EXPORT_SYMBOL(mdiobus_register_device);
+
+int mdiobus_unregister_device(struct mdio_device *mdiodev)
+{
+ if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
+ return -EINVAL;
+
+ mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
+
+ return 0;
+}
+EXPORT_SYMBOL(mdiobus_unregister_device);
+
+struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
+{
+ struct mdio_device *mdiodev = bus->mdio_map[addr];
+
+ if (!mdiodev)
+ return NULL;
+
+ if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
+ return NULL;
+
+ return container_of(mdiodev, struct phy_device, mdio);
+}
+EXPORT_SYMBOL(mdiobus_get_phy);
+
+bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
+{
+ return bus->mdio_map[addr];
+}
+EXPORT_SYMBOL(mdiobus_is_registered_device);
+
+/**
+ * mdiobus_alloc_size - allocate a mii_bus structure
+ * @size: extra amount of memory to allocate for private storage.
+ * If non-zero, then bus->priv is points to that memory.
+ *
+ * Description: called by a bus driver to allocate an mii_bus
+ * structure to fill in.
+ */
+struct mii_bus *mdiobus_alloc_size(size_t size)
+{
+ struct mii_bus *bus;
+ size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
+ size_t alloc_size;
+ int i;
+
+ /* If we alloc extra space, it should be aligned */
+ if (size)
+ alloc_size = aligned_size + size;
+ else
+ alloc_size = sizeof(*bus);
+
+ bus = kzalloc(alloc_size, GFP_KERNEL);
+ if (!bus)
+ return NULL;
+
+ bus->state = MDIOBUS_ALLOCATED;
+ if (size)
+ bus->priv = (void *)bus + aligned_size;
+
+ /* Initialise the interrupts to polling */
+ for (i = 0; i < PHY_MAX_ADDR; i++)
+ bus->irq[i] = PHY_POLL;
+
+ return bus;
+}
+EXPORT_SYMBOL(mdiobus_alloc_size);
+
+static void _devm_mdiobus_free(struct device *dev, void *res)
+{
+ mdiobus_free(*(struct mii_bus **)res);
+}
+
+static int devm_mdiobus_match(struct device *dev, void *res, void *data)
+{
+ struct mii_bus **r = res;
+
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ return *r == data;
+}
+
+/**
+ * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
+ * @dev: Device to allocate mii_bus for
+ * @sizeof_priv: Space to allocate for private structure.
+ *
+ * Managed mdiobus_alloc_size. mii_bus allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * If an mii_bus allocated with this function needs to be freed separately,
+ * devm_mdiobus_free() must be used.
+ *
+ * RETURNS:
+ * Pointer to allocated mii_bus on success, NULL on failure.
+ */
+struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
+{
+ struct mii_bus **ptr, *bus;
+
+ ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ /* use raw alloc_dr for kmalloc caller tracing */
+ bus = mdiobus_alloc_size(sizeof_priv);
+ if (bus) {
+ *ptr = bus;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return bus;
+}
+EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
+
+/**
+ * devm_mdiobus_free - Resource-managed mdiobus_free()
+ * @dev: Device this mii_bus belongs to
+ * @bus: the mii_bus associated with the device
+ *
+ * Free mii_bus allocated with devm_mdiobus_alloc_size().
+ */
+void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
+{
+ int rc;
+
+ rc = devres_release(dev, _devm_mdiobus_free,
+ devm_mdiobus_match, bus);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_mdiobus_free);
+
+/**
+ * mdiobus_release - mii_bus device release callback
+ * @d: the target struct device that contains the mii_bus
+ *
+ * Description: called when the last reference to an mii_bus is
+ * dropped, to free the underlying memory.
+ */
+static void mdiobus_release(struct device *d)
+{
+ struct mii_bus *bus = to_mii_bus(d);
+ BUG_ON(bus->state != MDIOBUS_RELEASED &&
+ /* for compatibility with error handling in drivers */
+ bus->state != MDIOBUS_ALLOCATED);
+ kfree(bus);
+}
+
+static struct class mdio_bus_class = {
+ .name = "mdio_bus",
+ .dev_release = mdiobus_release,
+};
+
+#if IS_ENABLED(CONFIG_OF_MDIO)
+/* Helper function for of_mdio_find_bus */
+static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
+{
+ return dev->of_node == mdio_bus_np;
+}
+/**
+ * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
+ * @mdio_bus_np: Pointer to the mii_bus.
+ *
+ * Returns a reference to the mii_bus, or NULL if none found. The
+ * embedded struct device will have its reference count incremented,
+ * and this must be put once the bus is finished with.
+ *
+ * Because the association of a device_node and mii_bus is made via
+ * of_mdiobus_register(), the mii_bus cannot be found before it is
+ * registered with of_mdiobus_register().
+ *
+ */
+struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
+{
+ struct device *d;
+
+ if (!mdio_bus_np)
+ return NULL;
+
+ d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
+ of_mdio_bus_match);
+
+ return d ? to_mii_bus(d) : NULL;
+}
+EXPORT_SYMBOL(of_mdio_find_bus);
+
+/* Walk the list of subnodes of a mdio bus and look for a node that
+ * matches the mdio device's address with its 'reg' property. If
+ * found, set the of_node pointer for the mdio device. This allows
+ * auto-probed phy devices to be supplied with information passed in
+ * via DT.
+ */
+static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
+ struct mdio_device *mdiodev)
+{
+ struct device *dev = &mdiodev->dev;
+ struct device_node *child;
+
+ if (dev->of_node || !bus->dev.of_node)
+ return;
+
+ for_each_available_child_of_node(bus->dev.of_node, child) {
+ int addr;
+
+ addr = of_mdio_parse_addr(dev, child);
+ if (addr < 0)
+ continue;
+
+ if (addr == mdiodev->addr) {
+ dev->of_node = child;
+ dev->fwnode = of_fwnode_handle(child);
+ return;
+ }
+ }
+}
+#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
+static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
+ struct mdio_device *mdiodev)
+{
+}
+#endif
+
+/**
+ * mdiobus_create_device_from_board_info - create a full MDIO device given
+ * a mdio_board_info structure
+ * @bus: MDIO bus to create the devices on
+ * @bi: mdio_board_info structure describing the devices
+ *
+ * Returns 0 on success or < 0 on error.
+ */
+static int mdiobus_create_device(struct mii_bus *bus,
+ struct mdio_board_info *bi)
+{
+ struct mdio_device *mdiodev;
+ int ret = 0;
+
+ mdiodev = mdio_device_create(bus, bi->mdio_addr);
+ if (IS_ERR(mdiodev))
+ return -ENODEV;
+
+ strncpy(mdiodev->modalias, bi->modalias,
+ sizeof(mdiodev->modalias));
+ mdiodev->bus_match = mdio_device_bus_match;
+ mdiodev->dev.platform_data = (void *)bi->platform_data;
+
+ ret = mdio_device_register(mdiodev);
+ if (ret)
+ mdio_device_free(mdiodev);
+
+ return ret;
+}
+
+/**
+ * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
+ * @bus: target mii_bus
+ * @owner: module containing bus accessor functions
+ *
+ * Description: Called by a bus driver to bring up all the PHYs
+ * on a given bus, and attach them to the bus. Drivers should use
+ * mdiobus_register() rather than __mdiobus_register() unless they
+ * need to pass a specific owner module. MDIO devices which are not
+ * PHYs will not be brought up by this function. They are expected to
+ * to be explicitly listed in DT and instantiated by of_mdiobus_register().
+ *
+ * Returns 0 on success or < 0 on error.
+ */
+int __mdiobus_register(struct mii_bus *bus, struct module *owner)
+{
+ struct mdio_device *mdiodev;
+ int i, err;
+ struct gpio_desc *gpiod;
+
+ if (NULL == bus || NULL == bus->name ||
+ NULL == bus->read || NULL == bus->write)
+ return -EINVAL;
+
+ BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
+ bus->state != MDIOBUS_UNREGISTERED);
+
+ bus->owner = owner;
+ bus->dev.parent = bus->parent;
+ bus->dev.class = &mdio_bus_class;
+ bus->dev.groups = NULL;
+ dev_set_name(&bus->dev, "%s", bus->id);
+
+ err = device_register(&bus->dev);
+ if (err) {
+ pr_err("mii_bus %s failed to register\n", bus->id);
+ put_device(&bus->dev);
+ return -EINVAL;
+ }
+
+ mutex_init(&bus->mdio_lock);
+
+ /* de-assert bus level PHY GPIO reset */
+ gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(gpiod)) {
+ dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
+ bus->id);
+ return PTR_ERR(gpiod);
+ } else if (gpiod) {
+ bus->reset_gpiod = gpiod;
+
+ gpiod_set_value_cansleep(gpiod, 1);
+ udelay(bus->reset_delay_us);
+ gpiod_set_value_cansleep(gpiod, 0);
+ }
+
+ if (bus->reset)
+ bus->reset(bus);
+
+ for (i = 0; i < PHY_MAX_ADDR; i++) {
+ if ((bus->phy_mask & (1 << i)) == 0) {
+ struct phy_device *phydev;
+
+ phydev = mdiobus_scan(bus, i);
+ if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
+ err = PTR_ERR(phydev);
+ goto error;
+ }
+ }
+ }
+
+ mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
+
+ bus->state = MDIOBUS_REGISTERED;
+ pr_info("%s: probed\n", bus->name);
+ return 0;
+
+error:
+ while (--i >= 0) {
+ mdiodev = bus->mdio_map[i];
+ if (!mdiodev)
+ continue;
+
+ mdiodev->device_remove(mdiodev);
+ mdiodev->device_free(mdiodev);
+ }
+
+ /* Put PHYs in RESET to save power */
+ if (bus->reset_gpiod)
+ gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+
+ device_del(&bus->dev);
+ return err;
+}
+EXPORT_SYMBOL(__mdiobus_register);
+
+void mdiobus_unregister(struct mii_bus *bus)
+{
+ struct mdio_device *mdiodev;
+ int i;
+
+ BUG_ON(bus->state != MDIOBUS_REGISTERED);
+ bus->state = MDIOBUS_UNREGISTERED;
+
+ for (i = 0; i < PHY_MAX_ADDR; i++) {
+ mdiodev = bus->mdio_map[i];
+ if (!mdiodev)
+ continue;
+
+ if (mdiodev->reset)
+ gpiod_put(mdiodev->reset);
+
+ mdiodev->device_remove(mdiodev);
+ mdiodev->device_free(mdiodev);
+ }
+
+ /* Put PHYs in RESET to save power */
+ if (bus->reset_gpiod)
+ gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+
+ device_del(&bus->dev);
+}
+EXPORT_SYMBOL(mdiobus_unregister);
+
+/**
+ * mdiobus_free - free a struct mii_bus
+ * @bus: mii_bus to free
+ *
+ * This function releases the reference to the underlying device
+ * object in the mii_bus. If this is the last reference, the mii_bus
+ * will be freed.
+ */
+void mdiobus_free(struct mii_bus *bus)
+{
+ /* For compatibility with error handling in drivers. */
+ if (bus->state == MDIOBUS_ALLOCATED) {
+ kfree(bus);
+ return;
+ }
+
+ BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
+ bus->state = MDIOBUS_RELEASED;
+
+ put_device(&bus->dev);
+}
+EXPORT_SYMBOL(mdiobus_free);
+
+/**
+ * mdiobus_scan - scan a bus for MDIO devices.
+ * @bus: mii_bus to scan
+ * @addr: address on bus to scan
+ *
+ * This function scans the MDIO bus, looking for devices which can be
+ * identified using a vendor/product ID in registers 2 and 3. Not all
+ * MDIO devices have such registers, but PHY devices typically
+ * do. Hence this function assumes anything found is a PHY, or can be
+ * treated as a PHY. Other MDIO devices, such as switches, will
+ * probably not be found during the scan.
+ */
+struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
+{
+ struct phy_device *phydev;
+ int err;
+
+ phydev = get_phy_device(bus, addr, false);
+ if (IS_ERR(phydev))
+ return phydev;
+
+ /*
+ * For DT, see if the auto-probed phy has a correspoding child
+ * in the bus node, and set the of_node pointer in this case.
+ */
+ of_mdiobus_link_mdiodev(bus, &phydev->mdio);
+
+ err = phy_device_register(phydev);
+ if (err) {
+ phy_device_free(phydev);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return phydev;
+}
+EXPORT_SYMBOL(mdiobus_scan);
+
+/**
+ * __mdiobus_read - Unlocked version of the mdiobus_read function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * Read a MDIO bus register. Caller must hold the mdio bus lock.
+ *
+ * NOTE: MUST NOT be called from interrupt context.
+ */
+int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
+{
+ int retval;
+
+ WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+
+ retval = bus->read(bus, addr, regnum);
+
+ trace_mdio_access(bus, 1, addr, regnum, retval, retval);
+
+ return retval;
+}
+EXPORT_SYMBOL(__mdiobus_read);
+
+/**
+ * __mdiobus_write - Unlocked version of the mdiobus_write function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * Write a MDIO bus register. Caller must hold the mdio bus lock.
+ *
+ * NOTE: MUST NOT be called from interrupt context.
+ */
+int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
+{
+ int err;
+
+ WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+
+ err = bus->write(bus, addr, regnum, val);
+
+ trace_mdio_access(bus, 0, addr, regnum, val, err);
+
+ return err;
+}
+EXPORT_SYMBOL(__mdiobus_write);
+
+/**
+ * mdiobus_read_nested - Nested version of the mdiobus_read function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * In case of nested MDIO bus access avoid lockdep false positives by
+ * using mutex_lock_nested().
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
+{
+ int retval;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+ retval = __mdiobus_read(bus, addr, regnum);
+ mutex_unlock(&bus->mdio_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(mdiobus_read_nested);
+
+/**
+ * mdiobus_read - Convenience function for reading a given MII mgmt register
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
+{
+ int retval;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock(&bus->mdio_lock);
+ retval = __mdiobus_read(bus, addr, regnum);
+ mutex_unlock(&bus->mdio_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(mdiobus_read);
+
+/**
+ * mdiobus_write_nested - Nested version of the mdiobus_write function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * In case of nested MDIO bus access avoid lockdep false positives by
+ * using mutex_lock_nested().
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
+{
+ int err;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+ err = __mdiobus_write(bus, addr, regnum, val);
+ mutex_unlock(&bus->mdio_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(mdiobus_write_nested);
+
+/**
+ * mdiobus_write - Convenience function for writing a given MII mgmt register
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
+{
+ int err;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock(&bus->mdio_lock);
+ err = __mdiobus_write(bus, addr, regnum, val);
+ mutex_unlock(&bus->mdio_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(mdiobus_write);
+
+/**
+ * mdio_bus_match - determine if given MDIO driver supports the given
+ * MDIO device
+ * @dev: target MDIO device
+ * @drv: given MDIO driver
+ *
+ * Description: Given a MDIO device, and a MDIO driver, return 1 if
+ * the driver supports the device. Otherwise, return 0. This may
+ * require calling the devices own match function, since different classes
+ * of MDIO devices have different match criteria.
+ */
+static int mdio_bus_match(struct device *dev, struct device_driver *drv)
+{
+ struct mdio_device *mdio = to_mdio_device(dev);
+
+ if (of_driver_match_device(dev, drv))
+ return 1;
+
+ if (mdio->bus_match)
+ return mdio->bus_match(dev, drv);
+
+ return 0;
+}
+
+static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ int rc;
+
+ /* Some devices have extra OF data and an OF-style MODALIAS */
+ rc = of_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
+ return 0;
+}
+
+struct bus_type mdio_bus_type = {
+ .name = "mdio_bus",
+ .match = mdio_bus_match,
+ .uevent = mdio_uevent,
+};
+EXPORT_SYMBOL(mdio_bus_type);
+
+int __init mdio_bus_init(void)
+{
+ int ret;
+
+ ret = class_register(&mdio_bus_class);
+ if (!ret) {
+ ret = bus_register(&mdio_bus_type);
+ if (ret)
+ class_unregister(&mdio_bus_class);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mdio_bus_init);
+
+#if IS_ENABLED(CONFIG_PHYLIB)
+void mdio_bus_exit(void)
+{
+ class_unregister(&mdio_bus_class);
+ bus_unregister(&mdio_bus_type);
+}
+EXPORT_SYMBOL_GPL(mdio_bus_exit);
+#else
+module_init(mdio_bus_init);
+/* no module_exit, intentional */
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MDIO bus/device layer");
+#endif