/* Framework for finding and configuring PHYs.
 * Also contains generic PHY driver
 *
 * 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/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/mdio.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/of.h>

#include <asm/irq.h>

MODULE_DESCRIPTION("PHY library");
MODULE_AUTHOR("Andy Fleming");
MODULE_LICENSE("GPL");

void phy_device_free(struct phy_device *phydev)
{
        put_device(&phydev->mdio_dev);
}
EXPORT_SYMBOL(phy_device_free);

static void phy_device_release(struct device *dev)
{
        kfree(to_phy_device(dev));
}

enum genphy_driver {
        GENPHY_DRV_1G,
        GENPHY_DRV_10G,
        GENPHY_DRV_MAX
};

static struct phy_driver genphy_driver[GENPHY_DRV_MAX];

static LIST_HEAD(phy_fixup_list);
static DEFINE_MUTEX(phy_fixup_lock);

#ifdef CONFIG_PM
static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
{
        struct device_driver *drv = phydev->mdio_dev.driver;
        struct phy_driver *phydrv = to_phy_driver(drv);
        struct net_device *netdev = phydev->attached_dev;

        if (!drv || !phydrv->suspend)
                return false;

        /* PHY not attached? May suspend if the PHY has not already been
         * suspended as part of a prior call to phy_disconnect() ->
         * phy_detach() -> phy_suspend() because the parent netdev might be the
         * MDIO bus driver and clock gated at this point.
         */
        if (!netdev)
                return !phydev->suspended;

        /* Don't suspend PHY if the attached netdev parent may wakeup.
         * The parent may point to a PCI device, as in tg3 driver.
         */
        if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
                return false;

        /* Also don't suspend PHY if the netdev itself may wakeup. This
         * is the case for devices w/o underlaying pwr. mgmt. aware bus,
         * e.g. SoC devices.
         */
        if (device_may_wakeup(&netdev->dev))
                return false;

        return true;
}

static int mdio_bus_phy_suspend(struct device *dev)
{
        struct phy_device *phydev = to_phy_device(dev);

        /* We must stop the state machine manually, otherwise it stops out of
         * control, possibly with the phydev->lock held. Upon resume, netdev
         * may call phy routines that try to grab the same lock, and that may
         * lead to a deadlock.
         */
        if (phydev->attached_dev && phydev->adjust_link)
                phy_stop_machine(phydev);

        if (!mdio_bus_phy_may_suspend(phydev))
                return 0;

        return phy_suspend(phydev);
}

static int mdio_bus_phy_resume(struct device *dev)
{
        struct phy_device *phydev = to_phy_device(dev);
        int ret;

        if (!mdio_bus_phy_may_suspend(phydev))
                goto no_resume;

        ret = phy_resume(phydev);
        if (ret < 0)
                return ret;

no_resume:
        if (phydev->attached_dev && phydev->adjust_link)
                phy_start_machine(phydev);

        return 0;
}

static int mdio_bus_phy_restore(struct device *dev)
{
        struct phy_device *phydev = to_phy_device(dev);
        struct net_device *netdev = phydev->attached_dev;
        int ret;

        if (!netdev)
                return 0;

        ret = phy_init_hw(phydev);
        if (ret < 0)
                return ret;

        if (phydev->attached_dev && phydev->adjust_link)
                phy_start_machine(phydev);

        return 0;
}

static const struct dev_pm_ops mdio_bus_phy_pm_ops = {
        .suspend = mdio_bus_phy_suspend,
        .resume = mdio_bus_phy_resume,
        .freeze = mdio_bus_phy_suspend,
        .thaw = mdio_bus_phy_resume,
        .restore = mdio_bus_phy_restore,
};

#define MDIO_BUS_PHY_PM_OPS (&mdio_bus_phy_pm_ops)

#else

#define MDIO_BUS_PHY_PM_OPS NULL

#endif /* CONFIG_PM */

/**
 * phy_register_fixup - creates a new phy_fixup and adds it to the list
 * @bus_id: A string which matches phydev->mdio_dev.bus_id (or PHY_ANY_ID)
 * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY)
 *      It can also be PHY_ANY_UID
 * @phy_uid_mask: Applied to phydev->phy_id and fixup->phy_uid before
 *      comparison
 * @run: The actual code to be run when a matching PHY is found
 */
int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
                       int (*run)(struct phy_device *))
{
        struct phy_fixup *fixup = kzalloc(sizeof(*fixup), GFP_KERNEL);

        if (!fixup)
                return -ENOMEM;

        strlcpy(fixup->bus_id, bus_id, sizeof(fixup->bus_id));
        fixup->phy_uid = phy_uid;
        fixup->phy_uid_mask = phy_uid_mask;
        fixup->run = run;

        mutex_lock(&phy_fixup_lock);
        list_add_tail(&fixup->list, &phy_fixup_list);
        mutex_unlock(&phy_fixup_lock);

        return 0;
}
EXPORT_SYMBOL(phy_register_fixup);

/* Registers a fixup to be run on any PHY with the UID in phy_uid */
int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
                               int (*run)(struct phy_device *))
{
        return phy_register_fixup(PHY_ANY_ID, phy_uid, phy_uid_mask, run);
}
EXPORT_SYMBOL(phy_register_fixup_for_uid);

/* Registers a fixup to be run on the PHY with id string bus_id */
int phy_register_fixup_for_id(const char *bus_id,
                              int (*run)(struct phy_device *))
{
        return phy_register_fixup(bus_id, PHY_ANY_UID, 0xffffffff, run);
}
EXPORT_SYMBOL(phy_register_fixup_for_id);

/* Returns 1 if fixup matches phydev in bus_id and phy_uid.
 * Fixups can be set to match any in one or more fields.
 */
static int phy_needs_fixup(struct phy_device *phydev, struct phy_fixup *fixup)
{
        if (strcmp(fixup->bus_id, phydev_name(phydev)) != 0)
                if (strcmp(fixup->bus_id, PHY_ANY_ID) != 0)
                        return 0;

        if ((fixup->phy_uid & fixup->phy_uid_mask) !=
            (phydev->phy_id & fixup->phy_uid_mask))
                if (fixup->phy_uid != PHY_ANY_UID)
                        return 0;

        return 1;
}

/* Runs any matching fixups for this phydev */
static int phy_scan_fixups(struct phy_device *phydev)
{
        struct phy_fixup *fixup;

        mutex_lock(&phy_fixup_lock);
        list_for_each_entry(fixup, &phy_fixup_list, list) {
                if (phy_needs_fixup(phydev, fixup)) {
                        int err = fixup->run(phydev);

                        if (err < 0) {
                                mutex_unlock(&phy_fixup_lock);
                                return err;
                        }
                }
        }
        mutex_unlock(&phy_fixup_lock);

        return 0;
}

struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
                                     bool is_c45,
                                     struct phy_c45_device_ids *c45_ids)
{
        struct phy_device *dev;

        /* We allocate the device, and initialize the default values */
        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (NULL == dev)
                return (struct phy_device *)PTR_ERR((void *)-ENOMEM);

        dev->mdio_dev.release = phy_device_release;
        dev->mdio_dev.parent = &bus->dev;
        dev->mdio_dev.bus = &mdio_bus_type;
        dev->mdio_bus = bus;
        dev->mdio_pm_ops = MDIO_BUS_PHY_PM_OPS;
        dev->mdio_addr = addr;
        dev->mdio_flags = MDIO_DEVICE_FLAG_PHY;

        dev->speed = 0;
        dev->duplex = -1;
        dev->pause = 0;
        dev->asym_pause = 0;
        dev->link = 1;
        dev->interface = PHY_INTERFACE_MODE_GMII;

        dev->autoneg = AUTONEG_ENABLE;

        dev->is_c45 = is_c45;
        dev->phy_id = phy_id;
        if (c45_ids)
                dev->c45_ids = *c45_ids;
        dev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
        dev_set_name(&dev->mdio_dev, PHY_ID_FMT, bus->id, addr);

        dev->state = PHY_DOWN;

        mutex_init(&dev->lock);
        INIT_DELAYED_WORK(&dev->state_queue, phy_state_machine);
        INIT_WORK(&dev->phy_queue, phy_change);

        /* Request the appropriate module unconditionally; don't
         * bother trying to do so only if it isn't already loaded,
         * because that gets complicated. A hotplug event would have
         * done an unconditional modprobe anyway.
         * We don't do normal hotplug because it won't work for MDIO
         * -- because it relies on the device staying around for long
         * enough for the driver to get loaded. With MDIO, the NIC
         * driver will get bored and give up as soon as it finds that
         * there's no driver _already_ loaded.
         */
        request_module(MDIO_MODULE_PREFIX MDIO_ID_FMT, MDIO_ID_ARGS(phy_id));

        device_initialize(&dev->mdio_dev);

        return dev;
}
EXPORT_SYMBOL(phy_device_create);

/**
 * get_phy_c45_ids - reads the specified addr for its 802.3-c45 IDs.
 * @bus: the target MII bus
 * @addr: PHY address on the MII bus
 * @phy_id: where to store the ID retrieved.
 * @c45_ids: where to store the c45 ID information.
 *
 *   If the PHY devices-in-package appears to be valid, it and the
 *   corresponding identifiers are stored in @c45_ids, zero is stored
 *   in @phy_id.  Otherwise 0xffffffff is stored in @phy_id.  Returns
 *   zero on success.
 *
 */
static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
                           struct phy_c45_device_ids *c45_ids) {
        int phy_reg;
        int i, reg_addr;
        const int num_ids = ARRAY_SIZE(c45_ids->device_ids);

        /* Find first non-zero Devices In package.  Device
         * zero is reserved, so don't probe it.
         */
        for (i = 1;
             i < num_ids && c45_ids->devices_in_package == 0;
             i++) {
                reg_addr = MII_ADDR_C45 | i << 16 | 6;
                phy_reg = mdiobus_read(bus, addr, reg_addr);
                if (phy_reg < 0)
                        return -EIO;
                c45_ids->devices_in_package = (phy_reg & 0xffff) << 16;

                reg_addr = MII_ADDR_C45 | i << 16 | 5;
                phy_reg = mdiobus_read(bus, addr, reg_addr);
                if (phy_reg < 0)
                        return -EIO;
                c45_ids->devices_in_package |= (phy_reg & 0xffff);

                /* If mostly Fs, there is no device there,
                 * let's get out of here.
                 */
                if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
                        *phy_id = 0xffffffff;
                        return 0;
                }
        }

        /* Now probe Device Identifiers for each device present. */
        for (i = 1; i < num_ids; i++) {
                if (!(c45_ids->devices_in_package & (1 << i)))
                        continue;

                reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID1;
                phy_reg = mdiobus_read(bus, addr, reg_addr);
                if (phy_reg < 0)
                        return -EIO;
                c45_ids->device_ids[i] = (phy_reg & 0xffff) << 16;

                reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID2;
                phy_reg = mdiobus_read(bus, addr, reg_addr);
                if (phy_reg < 0)
                        return -EIO;
                c45_ids->device_ids[i] |= (phy_reg & 0xffff);
        }
        *phy_id = 0;
        return 0;
}

/**
 * get_phy_id - reads the specified addr for its ID.
 * @bus: the target MII bus
 * @addr: PHY address on the MII bus
 * @phy_id: where to store the ID retrieved.
 * @is_c45: If true the PHY uses the 802.3 clause 45 protocol
 * @c45_ids: where to store the c45 ID information.
 *
 * Description: In the case of a 802.3-c22 PHY, reads the ID registers
 *   of the PHY at @addr on the @bus, stores it in @phy_id and returns
 *   zero on success.
 *
 *   In the case of a 802.3-c45 PHY, get_phy_c45_ids() is invoked, and
 *   its return value is in turn returned.
 *
 */
static int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id,
                      bool is_c45, struct phy_c45_device_ids *c45_ids)
{
        int phy_reg;

        if (is_c45)
                return get_phy_c45_ids(bus, addr, phy_id, c45_ids);

        /* Grab the bits from PHYIR1, and put them in the upper half */
        phy_reg = mdiobus_read(bus, addr, MII_PHYSID1);
        if (phy_reg < 0) {
                /* if there is no device, return without an error so scanning
                 * the bus works properly
                 */
                if (phy_reg == -EIO || phy_reg == -ENODEV) {
                        *phy_id = 0xffffffff;
                        return 0;
                }

                return -EIO;
        }

        *phy_id = (phy_reg & 0xffff) << 16;

        /* Grab the bits from PHYIR2, and put them in the lower half */
        phy_reg = mdiobus_read(bus, addr, MII_PHYSID2);
        if (phy_reg < 0)
                return -EIO;

        *phy_id |= (phy_reg & 0xffff);

        return 0;
}

/**
 * get_phy_device - reads the specified PHY device and returns its @phy_device
 *                  struct
 * @bus: the target MII bus
 * @addr: PHY address on the MII bus
 * @is_c45: If true the PHY uses the 802.3 clause 45 protocol
 *
 * Description: Reads the ID registers of the PHY at @addr on the
 *   @bus, then allocates and returns the phy_device to represent it.
 */
struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45)
{
        struct phy_c45_device_ids c45_ids = {0};
        u32 phy_id = 0;
        int r;

        r = get_phy_id(bus, addr, &phy_id, is_c45, &c45_ids);
        if (r)
                return ERR_PTR(r);

        /* If the phy_id is mostly Fs, there is no device there */
        if ((phy_id & 0x1fffffff) == 0x1fffffff)
                return ERR_PTR(-ENODEV);

        return phy_device_create(bus, addr, phy_id, is_c45, &c45_ids);
}
EXPORT_SYMBOL(get_phy_device);

/**
 * phy_device_register - Register the phy device on the MDIO bus
 * @phydev: phy_device structure to be added to the MDIO bus
 */
int phy_device_register(struct phy_device *phydev)
{
        int err;

        err = mdiobus_register_device(phydev);
        if (err)
                return err;

        /* Run all of the fixups for this PHY */
        err = phy_scan_fixups(phydev);
        if (err) {
                pr_err("PHY %d failed to initialize\n", phydev->mdio_addr);
                goto out;
        }

        err = device_add(&phydev->mdio_dev);
        if (err) {
                pr_err("PHY %d failed to add\n", phydev->mdio_addr);
                goto out;
        }

        return 0;

 out:
        mdiobus_unregister_device(phydev);
        return err;
}
EXPORT_SYMBOL(phy_device_register);

/**
 * phy_device_remove - Remove a previously registered phy device from the MDIO bus
 * @phydev: phy_device structure to remove
 *
 * This doesn't free the phy_device itself, it merely reverses the effects
 * of phy_device_register(). Use phy_device_free() to free the device
 * after calling this function.
 */
void phy_device_remove(struct phy_device *phydev)
{
        device_del(&phydev->mdio_dev);
        mdiobus_unregister_device(phydev);
}
EXPORT_SYMBOL(phy_device_remove);

/**
 * phy_find_first - finds the first PHY device on the bus
 * @bus: the target MII bus
 */
struct phy_device *phy_find_first(struct mii_bus *bus)
{
        struct phy_device *phydev;
        int addr;

        for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
                phydev = mdiobus_get_phy(bus, addr);
                if (phydev)
                        return phydev;
        }
        return NULL;
}
EXPORT_SYMBOL(phy_find_first);

/**
 * phy_prepare_link - prepares the PHY layer to monitor link status
 * @phydev: target phy_device struct
 * @handler: callback function for link status change notifications
 *
 * Description: Tells the PHY infrastructure to handle the
 *   gory details on monitoring link status (whether through
 *   polling or an interrupt), and to call back to the
 *   connected device driver when the link status changes.
 *   If you want to monitor your own link state, don't call
 *   this function.
 */
static void phy_prepare_link(struct phy_device *phydev,
                             void (*handler)(struct net_device *))
{
        phydev->adjust_link = handler;
}

/**
 * phy_connect_direct - connect an ethernet device to a specific phy_device
 * @dev: the network device to connect
 * @phydev: the pointer to the phy device
 * @handler: callback function for state change notifications
 * @interface: PHY device's interface
 */
int phy_connect_direct(struct net_device *dev, struct phy_device *phydev,
                       void (*handler)(struct net_device *),
                       phy_interface_t interface)
{
        int rc;

        rc = phy_attach_direct(dev, phydev, phydev->dev_flags, interface);
        if (rc)
                return rc;

        phy_prepare_link(phydev, handler);
        phy_start_machine(phydev);
        if (phydev->irq > 0)
                phy_start_interrupts(phydev);

        return 0;
}
EXPORT_SYMBOL(phy_connect_direct);

/**
 * phy_connect - connect an ethernet device to a PHY device
 * @dev: the network device to connect
 * @bus_id: the id string of the PHY device to connect
 * @handler: callback function for state change notifications
 * @interface: PHY device's interface
 *
 * 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 *bus_id,
                               void (*handler)(struct net_device *),
                               phy_interface_t interface)
{
        struct phy_device *phydev;
        struct device *d;
        int rc;

        /* Search the list of PHY devices on the mdio bus for the
         * PHY with the requested name
         */
        d = bus_find_device_by_name(&mdio_bus_type, NULL, bus_id);
        if (!d) {
                pr_err("PHY %s not found\n", bus_id);
                return ERR_PTR(-ENODEV);
        }
        phydev = to_phy_device(d);

        rc = phy_connect_direct(dev, phydev, handler, interface);
        if (rc)
                return ERR_PTR(rc);

        return phydev;
}
EXPORT_SYMBOL(phy_connect);

/**
 * phy_disconnect - disable interrupts, stop state machine, and detach a PHY
 *                  device
 * @phydev: target phy_device struct
 */
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);

/**
 * phy_poll_reset - Safely wait until a PHY reset has properly completed
 * @phydev: The PHY device to poll
 *
 * Description: According to IEEE 802.3, Section 2, Subsection 22.2.4.1.1, as
 *   published in 2008, a PHY reset may take up to 0.5 seconds.  The MII BMCR
 *   register must be polled until the BMCR_RESET bit clears.
 *
 *   Furthermore, any attempts to write to PHY registers may have no effect
 *   or even generate MDIO bus errors until this is complete.
 *
 *   Some PHYs (such as the Marvell 88E1111) don't entirely conform to the
 *   standard and do not fully reset after the BMCR_RESET bit is set, and may
 *   even *REQUIRE* a soft-reset to properly restart autonegotiation.  In an
 *   effort to support such broken PHYs, this function is separate from the
 *   standard phy_init_hw() which will zero all the other bits in the BMCR
 *   and reapply all driver-specific and board-specific fixups.
 */
static int phy_poll_reset(struct phy_device *phydev)
{
        /* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
        unsigned int retries = 12;
        int ret;

        do {
                msleep(50);
                ret = phy_read(phydev, MII_BMCR);
                if (ret < 0)
                        return ret;
        } while (ret & BMCR_RESET && --retries);
        if (ret & BMCR_RESET)
                return -ETIMEDOUT;

        /* Some chips (smsc911x) may still need up to another 1ms after the
         * BMCR_RESET bit is cleared before they are usable.
         */
        msleep(1);
        return 0;
}

int phy_init_hw(struct phy_device *phydev)
{
        int ret;

        if (!phydev->drv || !phydev->drv->config_init)
                return 0;

        ret = genphy_soft_reset(phydev);
        if (ret < 0)
                return ret;

        ret = phy_scan_fixups(phydev);
        if (ret < 0)
                return ret;

        return phydev->drv->config_init(phydev);
}
EXPORT_SYMBOL(phy_init_hw);

void phy_attached_info(struct phy_device *phydev)
{
        phy_attached_print(phydev, NULL);
}
EXPORT_SYMBOL(phy_attached_info);

#define ATTACHED_FMT "attached PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)"
void phy_attached_print(struct phy_device *phydev, const char *fmt, ...)
{
        if (!fmt) {
                dev_info(&phydev->mdio_dev, ATTACHED_FMT "\n",
                         phydev->drv->name, phydev_name(phydev),
                         phydev->irq);
        } else {
                va_list ap;

                dev_info(&phydev->mdio_dev, ATTACHED_FMT,
                         phydev->drv->name, phydev_name(phydev),
                         phydev->irq);

                va_start(ap, fmt);
                vprintk(fmt, ap);
                va_end(ap);
        }
}
EXPORT_SYMBOL(phy_attached_print);

/**
 * phy_attach_direct - attach a network device to a given PHY device pointer
 * @dev: network device to attach
 * @phydev: Pointer to phy_device to attach
 * @flags: PHY device's dev_flags
 * @interface: PHY device's interface
 *
 * 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 a
 *     generic 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.
 *     This function takes a reference on the phy device.
 */
int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
                      u32 flags, phy_interface_t interface)
{
        struct module *ndev_owner = dev->dev.parent->driver->owner;
        struct mii_bus *bus = phydev->mdio_bus;
        struct device *d = &phydev->mdio_dev;
        int err;

        /* For Ethernet device drivers that register their own MDIO bus, we
         * will have bus->owner match ndev_mod, so we do not want to increment
         * our own module->refcnt here, otherwise we would not be able to
         * unload later on.
         */
        if (ndev_owner != bus->owner && !try_module_get(bus->owner)) {
                dev_err(&dev->dev, "failed to get the bus module\n");
                return -EIO;
        }

        get_device(d);

        /* Assume that if there is no driver, that it doesn't
         * exist, and we should use the genphy driver.
         */
        if (NULL == d->driver) {
                if (phydev->is_c45)
                        d->driver = &genphy_driver[GENPHY_DRV_10G].driver;
                else
                        d->driver = &genphy_driver[GENPHY_DRV_1G].driver;

                err = d->driver->probe(d);
                if (err >= 0)
                        err = device_bind_driver(d);

                if (err)
                        goto error;
        }

        if (phydev->attached_dev) {
                dev_err(&dev->dev, "PHY already attached\n");
                err = -EBUSY;
                goto error;
        }

        phydev->attached_dev = dev;
        dev->phydev = phydev;

        phydev->dev_flags = flags;

        phydev->interface = interface;

        phydev->state = PHY_READY;

        /* Initial carrier state is off as the phy is about to be
         * (re)initialized.
         */
        netif_carrier_off(phydev->attached_dev);

        /* Do initial configuration here, now that
         * we have certain key parameters
         * (dev_flags and interface)
         */
        err = phy_init_hw(phydev);
        if (err)
                phy_detach(phydev);

        phy_resume(phydev);

        return err;

error:
        put_device(d);
        if (ndev_owner != bus->owner)
                module_put(bus->owner);
        return err;
}
EXPORT_SYMBOL(phy_attach_direct);

/**
 * phy_attach - attach a network device to a particular PHY device
 * @dev: network device to attach
 * @bus_id: Bus ID of PHY device to attach
 * @interface: PHY device's interface
 *
 * Description: Same as phy_attach_direct() except that a PHY bus_id
 *     string is passed instead of a pointer to a struct phy_device.
 */
struct phy_device *phy_attach(struct net_device *dev, const char *bus_id,
                              phy_interface_t interface)
{
        struct bus_type *bus = &mdio_bus_type;
        struct phy_device *phydev;
        struct device *d;
        int rc;

        /* Search the list of PHY devices on the mdio bus for the
         * PHY with the requested name
         */
        d = bus_find_device_by_name(bus, NULL, bus_id);
        if (!d) {
                pr_err("PHY %s not found\n", bus_id);
                return ERR_PTR(-ENODEV);
        }
        phydev = to_phy_device(d);

        rc = phy_attach_direct(dev, phydev, phydev->dev_flags, interface);
        if (rc)
                return ERR_PTR(rc);

        return phydev;
}
EXPORT_SYMBOL(phy_attach);

/**
 * phy_detach - detach a PHY device from its network device
 * @phydev: target phy_device struct
 *
 * This detaches the phy device from its network device and the phy
 * driver, and drops the reference count taken in phy_attach_direct().
 */
void phy_detach(struct phy_device *phydev)
{
        struct net_device *dev = phydev->attached_dev;
        struct module *ndev_owner = dev->dev.parent->driver->owner;
        struct mii_bus *bus;
        int i;

        phydev->attached_dev->phydev = NULL;
        phydev->attached_dev = NULL;
        phy_suspend(phydev);

        /* 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
         */
        for (i = 0; i < ARRAY_SIZE(genphy_driver); i++) {
                if (phydev->mdio_dev.driver == &genphy_driver[i].driver) {
                        device_release_driver(&phydev->mdio_dev);
                        break;
                }
        }

        /*
         * The phydev might go away on the put_device() below, so avoid
         * a use-after-free bug by reading the underlying bus first.
         */
        bus = phydev->mdio_bus;

        put_device(&phydev->mdio_dev);
        if (ndev_owner != bus->owner)
                module_put(bus->owner);
}
EXPORT_SYMBOL(phy_detach);

int phy_suspend(struct phy_device *phydev)
{
        struct phy_driver *phydrv = to_phy_driver(phydev->mdio_dev.driver);
        struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
        int ret = 0;

        /* If the device has WOL enabled, we cannot suspend the PHY */
        phy_ethtool_get_wol(phydev, &wol);
        if (wol.wolopts)
                return -EBUSY;

        if (phydev->drv && phydrv->suspend)
                ret = phydrv->suspend(phydev);

        if (ret)
                return ret;

        phydev->suspended = true;

        return ret;
}
EXPORT_SYMBOL(phy_suspend);

int __phy_resume(struct phy_device *phydev)
{
        struct phy_driver *phydrv = to_phy_driver(phydev->mdio_dev.driver);
        int ret = 0;

        WARN_ON(!mutex_is_locked(&phydev->lock));

        if (phydev->drv && phydrv->resume)
                ret = phydrv->resume(phydev);

        if (ret)
                return ret;

        phydev->suspended = false;

        return ret;
}
EXPORT_SYMBOL(__phy_resume);

int phy_resume(struct phy_device *phydev)
{
        int ret;

        mutex_lock(&phydev->lock);
        ret = __phy_resume(phydev);
        mutex_unlock(&phydev->lock);

        return ret;
}
EXPORT_SYMBOL(phy_resume);

/* Generic PHY support and helper functions */

/**
 * genphy_config_advert - sanitize and advertise auto-negotiation parameters
 * @phydev: target phy_device struct
 *
 * Description: Writes MII_ADVERTISE with the appropriate values,
 *   after sanitizing the values to make sure we only advertise
 *   what is supported.  Returns < 0 on error, 0 if the PHY's advertisement
 *   hasn't changed, and > 0 if it has changed.
 */
static int genphy_config_advert(struct phy_device *phydev)
{
        u32 advertise;
        int oldadv, adv;
        int err, changed = 0;

        /* Only allow advertising what this PHY supports */
        phydev->advertising &= phydev->supported;
        advertise = phydev->advertising;

        /* Setup standard advertisement */
        adv = phy_read(phydev, MII_ADVERTISE);
        if (adv < 0)
                return adv;

        oldadv = adv;
        adv &= ~(ADVERTISE_ALL | ADVERTISE_100BASE4 | ADVERTISE_PAUSE_CAP |
                 ADVERTISE_PAUSE_ASYM);
        adv |= ethtool_adv_to_mii_adv_t(advertise);

        if (adv != oldadv) {
                err = phy_write(phydev, MII_ADVERTISE, adv);

                if (err < 0)
                        return err;
                changed = 1;
        }

        /* Configure gigabit if it's supported */
        if (phydev->supported & (SUPPORTED_1000baseT_Half |
                                 SUPPORTED_1000baseT_Full)) {
                adv = phy_read(phydev, MII_CTRL1000);
                if (adv < 0)
                        return adv;

                oldadv = adv;
                adv &= ~(ADVERTISE_1000FULL | ADVERTISE_1000HALF);
                adv |= ethtool_adv_to_mii_ctrl1000_t(advertise);

                if (adv != oldadv) {
                        err = phy_write(phydev, MII_CTRL1000, adv);

                        if (err < 0)
                                return err;
                        changed = 1;
                }
        }

        return changed;
}

/**

 * genphy_config_eee_advert - disable unwanted eee mode advertisement
 * @phydev: target phy_device struct
 *
 * Description: Writes MDIO_AN_EEE_ADV after disabling unsupported energy
 *   efficent ethernet modes. Returns 0 if the PHY's advertisement hasn't
 *   changed, and 1 if it has changed.
 */
static int genphy_config_eee_advert(struct phy_device *phydev)
{
        int err;

        /* Nothing to disable */
        if (!phydev->eee_broken_modes)
                return 0;

        err = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV,
                                     phydev->eee_broken_modes, 0);
        /* If the call failed, we assume that EEE is not supported */
        return err < 0 ? 0 : err;
}

/**
 * genphy_setup_forced - configures/forces speed/duplex from @phydev
 * @phydev: target phy_device struct
 *
 * Description: Configures MII_BMCR to force speed/duplex
 *   to the values in phydev. Assumes that the values are valid.
 *   Please see phy_sanitize_settings().
 */
static int genphy_setup_forced(struct phy_device *phydev)
{
        u16 ctl = 0;

        phydev->pause = 0;
        phydev->asym_pause = 0;

        if (SPEED_1000 == phydev->speed)
                ctl |= BMCR_SPEED1000;
        else if (SPEED_100 == phydev->speed)
                ctl |= BMCR_SPEED100;

        if (DUPLEX_FULL == phydev->duplex)
                ctl |= BMCR_FULLDPLX;

        return phy_modify(phydev, MII_BMCR,
                          ~(BMCR_LOOPBACK | BMCR_ISOLATE | BMCR_PDOWN), ctl);
}


/**
 * genphy_restart_aneg - Enable and Restart Autonegotiation
 * @phydev: target phy_device struct
 */
int genphy_restart_aneg(struct phy_device *phydev)
{
        /* Don't isolate the PHY if we're negotiating */
        return phy_modify(phydev, MII_BMCR, BMCR_ISOLATE,
                          BMCR_ANENABLE | BMCR_ANRESTART);
}
EXPORT_SYMBOL(genphy_restart_aneg);

/**
 * genphy_config_aneg - restart auto-negotiation or write BMCR
 * @phydev: target phy_device struct
 *
 * Description: If auto-negotiation is enabled, we configure the
 *   advertising, and then restart auto-negotiation.  If it is not
 *   enabled, then we write the BMCR.
 */
int genphy_config_aneg(struct phy_device *phydev)
{
        int err, changed;

        changed = genphy_config_eee_advert(phydev);

        if (AUTONEG_ENABLE != phydev->autoneg)
                return genphy_setup_forced(phydev);

        err = genphy_config_advert(phydev);
        if (err < 0) /* error */
                return err;

        changed |= err;

        if (changed == 0) {
                /* Advertisement hasn't changed, but maybe aneg was never on to
                 * begin with?  Or maybe phy was isolated?
                 */
                int ctl = phy_read(phydev, MII_BMCR);

                if (ctl < 0)
                        return ctl;

                if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE))
                        changed = 1; /* do restart aneg */
        }

        /* Only restart aneg if we are advertising something different
         * than we were before.
         */
        if (changed > 0)
                return genphy_restart_aneg(phydev);

        return 0;
}
EXPORT_SYMBOL(genphy_config_aneg);

/**
 * genphy_aneg_done - return auto-negotiation status
 * @phydev: target phy_device struct
 *
 * Description: Reads the status register and returns 0 either if
 *   auto-negotiation is incomplete, or if there was an error.
 *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
 */
int genphy_aneg_done(struct phy_device *phydev)
{
        int retval = phy_read(phydev, MII_BMSR);

        return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
}
EXPORT_SYMBOL(genphy_aneg_done);

static int gen10g_config_aneg(struct phy_device *phydev)
{
        return 0;
}

/**
 * genphy_update_link - update link status in @phydev
 * @phydev: target phy_device struct
 *
 * Description: Update the value in phydev->link to reflect the
 *   current link value.  In order to do this, we need to read
 *   the status register twice, keeping the second value.
 */
int genphy_update_link(struct phy_device *phydev)
{
        int status;

        /* Do a fake read */
        status = phy_read(phydev, MII_BMSR);
        if (status < 0)
                return status;

        /* Read link and autonegotiation status */
        status = phy_read(phydev, MII_BMSR);
        if (status < 0)
                return status;

        if ((status & BMSR_LSTATUS) == 0)
                phydev->link = 0;
        else
                phydev->link = 1;

        return 0;
}
EXPORT_SYMBOL(genphy_update_link);

/**
 * genphy_read_status - check the link status and update current link state
 * @phydev: target phy_device struct
 *
 * Description: Check the link, then figure out the current state
 *   by comparing what we advertise with what the link partner
 *   advertises.  Start by checking the gigabit possibilities,
 *   then move on to 10/100.
 */
int genphy_read_status(struct phy_device *phydev)
{
        int adv;
        int err;
        int lpa;
        int lpagb = 0;

        /* Update the link, but return if there was an error */
        err = genphy_update_link(phydev);
        if (err)
                return err;

        phydev->lp_advertising = 0;

        if (AUTONEG_ENABLE == phydev->autoneg) {
                if (phydev->supported & (SUPPORTED_1000baseT_Half
                                        | SUPPORTED_1000baseT_Full)) {
                        lpagb = phy_read(phydev, MII_STAT1000);
                        if (lpagb < 0)
                                return lpagb;

                        adv = phy_read(phydev, MII_CTRL1000);
                        if (adv < 0)
                                return adv;

                        phydev->lp_advertising =
                                mii_stat1000_to_ethtool_lpa_t(lpagb);
                        lpagb &= adv << 2;
                }

                lpa = phy_read(phydev, MII_LPA);
                if (lpa < 0)
                        return lpa;

                phydev->lp_advertising |= mii_lpa_to_ethtool_lpa_t(lpa);

                adv = phy_read(phydev, MII_ADVERTISE);
                if (adv < 0)
                        return adv;

                lpa &= adv;

                phydev->speed = SPEED_10;
                phydev->duplex = DUPLEX_HALF;
                phydev->pause = 0;
                phydev->asym_pause = 0;

                if (lpagb & (LPA_1000FULL | LPA_1000HALF)) {
                        phydev->speed = SPEED_1000;

                        if (lpagb & LPA_1000FULL)
                                phydev->duplex = DUPLEX_FULL;
                } else if (lpa & (LPA_100FULL | LPA_100HALF)) {
                        phydev->speed = SPEED_100;

                        if (lpa & LPA_100FULL)
                                phydev->duplex = DUPLEX_FULL;
                } else
                        if (lpa & LPA_10FULL)
                                phydev->duplex = DUPLEX_FULL;

                if (phydev->duplex == DUPLEX_FULL) {
                        phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;
                        phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;
                }
        } else {
                int bmcr = phy_read(phydev, MII_BMCR);

                if (bmcr < 0)
                        return bmcr;

                if (bmcr & BMCR_FULLDPLX)
                        phydev->duplex = DUPLEX_FULL;
                else
                        phydev->duplex = DUPLEX_HALF;

                if (bmcr & BMCR_SPEED1000)
                        phydev->speed = SPEED_1000;
                else if (bmcr & BMCR_SPEED100)
                        phydev->speed = SPEED_100;
                else
                        phydev->speed = SPEED_10;

                phydev->pause = 0;
                phydev->asym_pause = 0;
        }

        return 0;
}
EXPORT_SYMBOL(genphy_read_status);

static int gen10g_read_status(struct phy_device *phydev)
{
        u32 mmd_mask = phydev->c45_ids.devices_in_package;
        int ret;

        /* For now just lie and say it's 10G all the time */
        phydev->speed = SPEED_10000;
        phydev->duplex = DUPLEX_FULL;

        /* Avoid reading the vendor MMDs */
        mmd_mask &= ~(BIT(MDIO_MMD_VEND1) | BIT(MDIO_MMD_VEND2));

        ret = genphy_c45_read_link(phydev, mmd_mask);

        phydev->link = ret > 0 ? 1 : 0;

        return 0;
}

/**
 * genphy_soft_reset - software reset the PHY via BMCR_RESET bit
 * @phydev: target phy_device struct
 *
 * Description: Perform a software PHY reset using the standard
 * BMCR_RESET bit and poll for the reset bit to be cleared.
 *
 * Returns: 0 on success, < 0 on failure
 */
int genphy_soft_reset(struct phy_device *phydev)
{
        int ret;

        ret = phy_write(phydev, MII_BMCR, BMCR_RESET);
        if (ret < 0)
                return ret;

        return phy_poll_reset(phydev);
}
EXPORT_SYMBOL(genphy_soft_reset);

int genphy_config_init(struct phy_device *phydev)
{
        int val;
        u32 features;

        /* For now, I'll claim that the generic driver supports
         * all possible port types
         */
        features = (SUPPORTED_TP | SUPPORTED_MII
                        | SUPPORTED_AUI | SUPPORTED_FIBRE |
                        SUPPORTED_BNC);

        /* Do we support autonegotiation? */
        val = phy_read(phydev, MII_BMSR);
        if (val < 0)
                return val;

        if (val & BMSR_ANEGCAPABLE)
                features |= SUPPORTED_Autoneg;

        if (val & BMSR_100FULL)
                features |= SUPPORTED_100baseT_Full;
        if (val & BMSR_100HALF)
                features |= SUPPORTED_100baseT_Half;
        if (val & BMSR_10FULL)
                features |= SUPPORTED_10baseT_Full;
        if (val & BMSR_10HALF)
                features |= SUPPORTED_10baseT_Half;

        if (val & BMSR_ESTATEN) {
                val = phy_read(phydev, MII_ESTATUS);
                if (val < 0)
                        return val;

                if (val & ESTATUS_1000_TFULL)
                        features |= SUPPORTED_1000baseT_Full;
                if (val & ESTATUS_1000_THALF)
                        features |= SUPPORTED_1000baseT_Half;
        }

        phydev->supported = features;
        phydev->advertising = features;

        return 0;
}
EXPORT_SYMBOL(genphy_config_init);

static int gen10g_config_init(struct phy_device *phydev)
{
        /* Temporarily just say we support everything */
        phydev->supported = SUPPORTED_10000baseT_Full;
        phydev->advertising = SUPPORTED_10000baseT_Full;

        return 0;
}

int genphy_suspend(struct phy_device *phydev)
{
        return phy_modify(phydev, MII_BMCR, 0, BMCR_PDOWN);
}
EXPORT_SYMBOL(genphy_suspend);

static int gen10g_suspend(struct phy_device *phydev)
{
        return 0;
}

int genphy_resume(struct phy_device *phydev)
{
        return phy_modify(phydev, MII_BMCR, BMCR_PDOWN, 0);
}
EXPORT_SYMBOL(genphy_resume);

static int gen10g_resume(struct phy_device *phydev)
{
        return 0;
}

static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
{
        phydev->supported &= ~(PHY_1000BT_FEATURES | PHY_100BT_FEATURES |
                               PHY_10BT_FEATURES);

        switch (max_speed) {
        default:
                return -ENOTSUPP;
        case SPEED_1000:
                phydev->supported |= PHY_1000BT_FEATURES;
                /* fall through */
        case SPEED_100:
                phydev->supported |= PHY_100BT_FEATURES;
                /* fall through */
        case SPEED_10:
                phydev->supported |= PHY_10BT_FEATURES;
        }

        return 0;
}

int phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
{
        int err;

        err = __set_phy_supported(phydev, max_speed);
        if (err)
                return err;

        phydev->advertising = phydev->supported;

        return 0;
}
EXPORT_SYMBOL(phy_set_max_speed);

static void of_set_phy_eee_broken(struct phy_device *phydev)
{
        struct device_node *node = phydev->mdio_dev.of_node;
        u32 broken;

        if (!IS_ENABLED(CONFIG_OF_MDIO))
                return;

        if (!node)
                return;

        if (!of_property_read_u32(node, "eee-broken-modes", &broken))
                phydev->eee_broken_modes = broken;
}

/**
 * phy_probe - probe and init a PHY device
 * @dev: device to probe and init
 *
 * Description: Take care of setting up the phy_device structure,
 *   set the state to READY (the driver's init function should
 *   set it to STARTING if needed).
 */
static int phy_probe(struct device *dev)
{
        struct phy_device *phydev = to_phy_device(dev);
        struct device_driver *drv = phydev->mdio_dev.driver;
        struct phy_driver *phydrv = to_phy_driver(drv);
        int err = 0;

        phydev->drv = phydrv;

        /* Disable the interrupt if the PHY doesn't support it
         * but the interrupt is still a valid one
         */
        if (!(phydrv->flags & PHY_HAS_INTERRUPT) &&
            phy_interrupt_is_valid(phydev))
                phydev->irq = PHY_POLL;

        if (phydrv->flags & PHY_IS_INTERNAL)
                phydev->is_internal = true;

        mutex_lock(&phydev->lock);

        /* Start out supporting everything. Eventually,
         * a controller will attach, and may modify one
         * or both of these values
         */
        phydev->supported = phydrv->features;
        phydev->advertising = phydrv->features;

        /* Get the EEE modes we want to prohibit. We will ask
         * the PHY stop advertising these mode later on
         */
        of_set_phy_eee_broken(phydev);

        /* Set the state to READY by default */
        phydev->state = PHY_READY;

        if (phydev->drv->probe)
                err = phydev->drv->probe(phydev);

        mutex_unlock(&phydev->lock);

        return err;
}

static int phy_remove(struct device *dev)
{
        struct phy_device *phydev = to_phy_device(dev);

        cancel_delayed_work_sync(&phydev->state_queue);

        mutex_lock(&phydev->lock);
        phydev->state = PHY_DOWN;
        mutex_unlock(&phydev->lock);

        if (phydev->drv && phydev->drv->remove)
                phydev->drv->remove(phydev);
        phydev->drv = NULL;

        return 0;
}

/**
 * phy_driver_register - register a phy_driver with the PHY layer
 * @new_driver: new phy_driver to register
 */
int phy_driver_register(struct phy_driver *new_driver)
{
        int retval;

        new_driver->driver.name = new_driver->name;
        new_driver->driver.bus = &mdio_bus_type;
        new_driver->driver.probe = phy_probe;
        new_driver->driver.remove = phy_remove;

        retval = driver_register(&new_driver->driver);
        if (retval) {
                pr_err("%s: Error %d in registering driver\n",
                       new_driver->name, retval);

                return retval;
        }

        pr_debug("%s: Registered new driver\n", new_driver->name);

        return 0;
}
EXPORT_SYMBOL(phy_driver_register);

int phy_drivers_register(struct phy_driver *new_driver, int n)
{
        int i, ret = 0;

        for (i = 0; i < n; i++) {
                ret = phy_driver_register(new_driver + i);
                if (ret) {
                        while (i-- > 0)
                                phy_driver_unregister(new_driver + i);
                        break;
                }
        }
        return ret;
}
EXPORT_SYMBOL(phy_drivers_register);

void phy_driver_unregister(struct phy_driver *drv)
{
        driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(phy_driver_unregister);

void phy_drivers_unregister(struct phy_driver *drv, int n)
{
        int i;

        for (i = 0; i < n; i++)
                phy_driver_unregister(drv + i);
}
EXPORT_SYMBOL(phy_drivers_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,
        .aneg_done      = genphy_aneg_done,
        .read_status    = genphy_read_status,
        .suspend        = genphy_suspend,
        .resume         = genphy_resume,
        .driver         = { .owner = THIS_MODULE, },
}, {
        .phy_id         = 0xffffffff,
        .phy_id_mask    = 0xffffffff,
        .name           = "Generic 10G PHY",
        .config_init    = gen10g_config_init,
        .features       = 0,
        .config_aneg    = gen10g_config_aneg,
        .read_status    = gen10g_read_status,
        .suspend        = gen10g_suspend,
        .resume         = gen10g_resume,
        .driver         = {.owner = THIS_MODULE, },
} };

static int __init phy_init(void)
{
        int rc;

        rc = mdio_bus_init();
        if (rc)
                return rc;

        rc = phy_drivers_register(genphy_driver,
                                  ARRAY_SIZE(genphy_driver));
        if (rc)
                mdio_bus_exit();

        return rc;
}

static void __exit phy_exit(void)
{
        phy_drivers_unregister(genphy_driver,
                               ARRAY_SIZE(genphy_driver));
        mdio_bus_exit();
}

subsys_initcall(phy_init);
module_exit(phy_exit);