/* Framework for configuring and reading PHY devices
 * Based on code in sungem_phy.c and gianfar_phy.c
 *
 * Author: Andy Fleming
 *
 * Copyright (c) 2004 Freescale Semiconductor, Inc.
 * Copyright (c) 2006, 2007  Maciej W. Rozycki
 *
 * 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/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/timer.h>
#include <linux/workqueue.h>
#include <linux/mdio.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>

#include <asm/irq.h>

/**
 * phy_print_status - Convenience function to print out the current phy status
 * @phydev: the phy_device struct
 */
void phy_print_status(struct phy_device *phydev)
{
        if (phydev->link) {
                pr_info("%s - Link is Up - %d/%s\n",
                        dev_name(&phydev->mdio_dev),
                        phydev->speed,
                        DUPLEX_FULL == phydev->duplex ? "Full" : "Half");
        } else  {
                pr_info("%s - Link is Down\n", dev_name(&phydev->mdio_dev));
        }
}
EXPORT_SYMBOL(phy_print_status);

/**
 * phy_clear_interrupt - Ack the phy device's interrupt
 * @phydev: the phy_device struct
 *
 * If the @phydev driver has an ack_interrupt function, call it to
 * ack and clear the phy device's interrupt.
 *
 * Returns 0 on success on < 0 on error.
 */
static int phy_clear_interrupt(struct phy_device *phydev)
{
        if (phydev->drv->ack_interrupt)
                return phydev->drv->ack_interrupt(phydev);

        return 0;
}

/**
 * phy_config_interrupt - configure the PHY device for the requested interrupts
 * @phydev: the phy_device struct
 * @interrupts: interrupt flags to configure for this @phydev
 *
 * Returns 0 on success on < 0 on error.
 */
static int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
{
        phydev->interrupts = interrupts;
        if (phydev->drv->config_intr)
                return phydev->drv->config_intr(phydev);

        return 0;
}

/**
 * phy_restart_aneg - restart auto-negotiation
 * @phydev: target phy_device struct
 *
 * Restart the autonegotiation on @phydev.  Returns >= 0 on success or
 * negative errno on error.
 */
int phy_restart_aneg(struct phy_device *phydev)
{
        int ret;

        if (phydev->is_c45 && !(phydev->c45_ids.devices_in_package & BIT(0)))
                ret = genphy_c45_restart_aneg(phydev);
        else
                ret = genphy_restart_aneg(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_restart_aneg);

/**
 * phy_aneg_done - return auto-negotiation status
 * @phydev: target phy_device struct
 *
 * Description: Return the auto-negotiation status from this @phydev
 * Returns > 0 on success or < 0 on error. 0 means that auto-negotiation
 * is still pending.
 */
int phy_aneg_done(struct phy_device *phydev)
{
        if (phydev->drv && phydev->drv->aneg_done)
                return phydev->drv->aneg_done(phydev);

        /* Avoid genphy_aneg_done() if the Clause 45 PHY does not
         * implement Clause 22 registers
         */
        if (phydev->is_c45 && !(phydev->c45_ids.devices_in_package & BIT(0)))
                return -EINVAL;

        return genphy_aneg_done(phydev);
}
EXPORT_SYMBOL(phy_aneg_done);

/* A structure for mapping a particular speed and duplex
 * combination to a particular SUPPORTED and ADVERTISED value
 */
struct phy_setting {
        int speed;
        int duplex;
        u32 setting;
};

/* A mapping of all SUPPORTED settings to speed/duplex */
static const struct phy_setting settings[] = {
        {
                .speed = 10000,
                .duplex = DUPLEX_FULL,
                .setting = SUPPORTED_10000baseT_Full,
        },
        {
                .speed = SPEED_1000,
                .duplex = DUPLEX_FULL,
                .setting = SUPPORTED_1000baseT_Full,
        },
        {
                .speed = SPEED_1000,
                .duplex = DUPLEX_HALF,
                .setting = SUPPORTED_1000baseT_Half,
        },
        {
                .speed = SPEED_100,
                .duplex = DUPLEX_FULL,
                .setting = SUPPORTED_100baseT_Full,
        },
        {
                .speed = SPEED_100,
                .duplex = DUPLEX_HALF,
                .setting = SUPPORTED_100baseT_Half,
        },
        {
                .speed = SPEED_10,
                .duplex = DUPLEX_FULL,
                .setting = SUPPORTED_10baseT_Full,
        },
        {
                .speed = SPEED_10,
                .duplex = DUPLEX_HALF,
                .setting = SUPPORTED_10baseT_Half,
        },
};

#define MAX_NUM_SETTINGS ARRAY_SIZE(settings)

/**
 * phy_find_setting - find a PHY settings array entry that matches speed & duplex
 * @speed: speed to match
 * @duplex: duplex to match
 *
 * Description: Searches the settings array for the setting which
 *   matches the desired speed and duplex, and returns the index
 *   of that setting.  Returns the index of the last setting if
 *   none of the others match.
 */
static inline int phy_find_setting(int speed, int duplex)
{
        int idx = 0;

        while (idx < ARRAY_SIZE(settings) &&
               (settings[idx].speed != speed || settings[idx].duplex != duplex))
                idx++;

        return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
}

/**
 * phy_find_valid - find a PHY setting that matches the requested features mask
 * @idx: The first index in settings[] to search
 * @features: A mask of the valid settings
 *
 * Description: Returns the index of the first valid setting less
 *   than or equal to the one pointed to by idx, as determined by
 *   the mask in features.  Returns the index of the last setting
 *   if nothing else matches.
 */
static inline int phy_find_valid(int idx, u32 features)
{
        while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
                idx++;

        return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
}

/**
 * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
 * @phydev: the target phy_device struct
 *
 * Description: Make sure the PHY is set to supported speeds and
 *   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)
{
        u32 features = phydev->supported;
        int idx;

        /* Sanitize settings based on PHY capabilities */
        if ((features & SUPPORTED_Autoneg) == 0)
                phydev->autoneg = AUTONEG_DISABLE;

        idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
                        features);

        phydev->speed = settings[idx].speed;
        phydev->duplex = settings[idx].duplex;
}

/**
 * phy_ethtool_sset - generic ethtool sset function, handles all the details
 * @phydev: target phy_device struct
 * @cmd: ethtool_cmd
 *
 * A few notes about parameter checking:
 * - We don't set port or transceiver, so we don't care what they
 *   were set to.
 * - 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.
 */
int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
{
        u32 speed = ethtool_cmd_speed(cmd);

        if (cmd->phy_address != phydev->mdio_addr)
                return -EINVAL;

        /* We make sure that we don't pass unsupported values in to the PHY */
        cmd->advertising &= phydev->supported;

        /* Verify the settings we care about. */
        if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
                return -EINVAL;

        if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
                return -EINVAL;

        if (cmd->autoneg == AUTONEG_DISABLE &&
            ((speed != SPEED_1000 &&
              speed != SPEED_100 &&
              speed != SPEED_10) ||
             (cmd->duplex != DUPLEX_HALF &&
              cmd->duplex != DUPLEX_FULL)))
                return -EINVAL;

        phydev->autoneg = cmd->autoneg;

        phydev->speed = speed;

        phydev->advertising = cmd->advertising;

        if (AUTONEG_ENABLE == cmd->autoneg)
                phydev->advertising |= ADVERTISED_Autoneg;
        else
                phydev->advertising &= ~ADVERTISED_Autoneg;

        phydev->duplex = cmd->duplex;

        phydev->mdix = cmd->eth_tp_mdix_ctrl;

        /* Restart the PHY */
        phy_start_aneg(phydev);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_sset);

int phy_ethtool_ksettings_set(struct phy_device *phydev,
                              const struct ethtool_link_ksettings *cmd)
{
        u8 autoneg = cmd->base.autoneg;
        u8 duplex = cmd->base.duplex;
        u32 speed = cmd->base.speed;
        u32 advertising;

        if (cmd->base.phy_address != phydev->mdio_addr)
                return -EINVAL;

        ethtool_convert_link_mode_to_legacy_u32(&advertising,
                                                cmd->link_modes.advertising);

        /* We make sure that we don't pass unsupported values in to the PHY */
        advertising &= phydev->supported;

        /* Verify the settings we care about. */
        if (autoneg != AUTONEG_ENABLE && autoneg != AUTONEG_DISABLE)
                return -EINVAL;

        if (autoneg == AUTONEG_ENABLE && advertising == 0)
                return -EINVAL;

        if (autoneg == AUTONEG_DISABLE &&
            ((speed != SPEED_1000 &&
              speed != SPEED_100 &&
              speed != SPEED_10) ||
             (duplex != DUPLEX_HALF &&
              duplex != DUPLEX_FULL)))
                return -EINVAL;

        phydev->autoneg = autoneg;

        phydev->speed = speed;

        phydev->advertising = advertising;

        if (autoneg == AUTONEG_ENABLE)
                phydev->advertising |= ADVERTISED_Autoneg;
        else
                phydev->advertising &= ~ADVERTISED_Autoneg;

        phydev->duplex = duplex;

        phydev->mdix = cmd->base.eth_tp_mdix_ctrl;

        /* Restart the PHY */
        phy_start_aneg(phydev);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_ksettings_set);

int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
{
        cmd->supported = phydev->supported;

        cmd->advertising = phydev->advertising;
        cmd->lp_advertising = phydev->lp_advertising;

        ethtool_cmd_speed_set(cmd, phydev->speed);
        cmd->duplex = phydev->duplex;
        if (phydev->interface == PHY_INTERFACE_MODE_MOCA)
                cmd->port = PORT_BNC;
        else
                cmd->port = PORT_MII;
        cmd->phy_address = phydev->mdio_addr;
        cmd->transceiver = phy_is_internal(phydev) ?
                XCVR_INTERNAL : XCVR_EXTERNAL;
        cmd->autoneg = phydev->autoneg;
        cmd->eth_tp_mdix_ctrl = phydev->mdix;

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_gset);

int phy_ethtool_ksettings_get(struct phy_device *phydev,
                              struct ethtool_link_ksettings *cmd)
{
        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
                                                phydev->supported);

        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
                                                phydev->advertising);

        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.lp_advertising,
                                                phydev->lp_advertising);

        cmd->base.speed = phydev->speed;
        cmd->base.duplex = phydev->duplex;
        if (phydev->interface == PHY_INTERFACE_MODE_MOCA)
                cmd->base.port = PORT_BNC;
        else
                cmd->base.port = PORT_MII;
        cmd->base.transceiver = phy_is_internal(phydev) ?
                                XCVR_INTERNAL : XCVR_EXTERNAL;
        cmd->base.phy_address = phydev->mdio_addr;
        cmd->base.autoneg = phydev->autoneg;
        cmd->base.eth_tp_mdix_ctrl = phydev->mdix;

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_ksettings_get);

/**
 * phy_mii_ioctl - generic PHY MII ioctl interface
 * @phydev: the phy_device struct
 * @ifr: &struct ifreq for socket ioctl's
 * @cmd: ioctl cmd to execute
 *
 * Note that this function is currently incompatible with the
 * PHYCONTROL layer.  It changes registers without regard to
 * current state.  Use at own risk.
 */
int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd)
{
        struct mii_ioctl_data *mii_data = if_mii(ifr);
        u16 val = mii_data->val_in;

        switch (cmd) {
        case SIOCGMIIPHY:
                mii_data->phy_id = phydev->mdio_addr;
                /* fall through */

        case SIOCGMIIREG:
                mii_data->val_out = mdiobus_read(phydev->mdio_bus,
                                                 mii_data->phy_id,
                                                 mii_data->reg_num);
                return 0;

        case SIOCSMIIREG:
                if (mii_data->phy_id == phydev->mdio_addr) {
                        switch (mii_data->reg_num) {
                        case MII_BMCR:
                                if ((val & (BMCR_RESET | BMCR_ANENABLE)) == 0)
                                        phydev->autoneg = AUTONEG_DISABLE;
                                else
                                        phydev->autoneg = AUTONEG_ENABLE;
                                if (!phydev->autoneg && (val & BMCR_FULLDPLX))
                                        phydev->duplex = DUPLEX_FULL;
                                else
                                        phydev->duplex = DUPLEX_HALF;
                                if (!phydev->autoneg && (val & BMCR_SPEED1000))
                                        phydev->speed = SPEED_1000;
                                else if (!phydev->autoneg &&
                                         (val & BMCR_SPEED100))
                                        phydev->speed = SPEED_100;
                                break;
                        case MII_ADVERTISE:
                                phydev->advertising = val;
                                break;
                        default:
                                /* do nothing */
                                break;
                        }
                }

                mdiobus_write(phydev->mdio_bus, mii_data->phy_id,
                              mii_data->reg_num, val);

                if (mii_data->reg_num == MII_BMCR &&
                    val & BMCR_RESET)
                        return phy_init_hw(phydev);
                return 0;

        case SIOCSHWTSTAMP:
                if (phydev->drv && phydev->drv->hwtstamp)
                        return phydev->drv->hwtstamp(phydev, ifr);
                /* fall through */

        default:
                return -EOPNOTSUPP;
        }
}
EXPORT_SYMBOL(phy_mii_ioctl);

static int phy_config_aneg(struct phy_device *phydev)
{
        if (phydev->drv->config_aneg)
                return phydev->drv->config_aneg(phydev);
        else
                return genphy_config_aneg(phydev);
}

/**
 * phy_start_aneg - start auto-negotiation for this PHY device
 * @phydev: the phy_device struct
 *
 * 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;

        if (!phydev->drv)
                return -EIO;

        mutex_lock(&phydev->lock);

        if (AUTONEG_DISABLE == phydev->autoneg)
                phy_sanitize_settings(phydev);

        /* Invalidate LP advertising flags */
        phydev->lp_advertising = 0;

        err = phy_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:
        mutex_unlock(&phydev->lock);
        return err;
}
EXPORT_SYMBOL(phy_start_aneg);

static int phy_poll_aneg_done(struct phy_device *phydev)
{
        unsigned int retries = 100;
        int ret;

        do {
                msleep(100);
                ret = phy_aneg_done(phydev);
        } while (!ret && --retries);

        if (!ret)
                return -ETIMEDOUT;

        return ret < 0 ? ret : 0;
}

/**
 * phy_speed_down - set speed to lowest speed supported by both link partners
 * @phydev: the phy_device struct
 * @sync: perform action synchronously
 *
 * Description: Typically used to save energy when waiting for a WoL packet
 *
 * WARNING: Setting sync to false may cause the system being unable to suspend
 * in case the PHY generates an interrupt when finishing the autonegotiation.
 * This interrupt may wake up the system immediately after suspend.
 * Therefore use sync = false only if you're sure it's safe with the respective
 * network chip.
 */
int phy_speed_down(struct phy_device *phydev, bool sync)
{
        u32 adv = phydev->lp_advertising & phydev->supported;
        u32 adv_old = phydev->advertising;
        int ret;

        if (phydev->autoneg != AUTONEG_ENABLE)
                return 0;

        if (adv & PHY_10BT_FEATURES)
                phydev->advertising &= ~(PHY_100BT_FEATURES |
                                         PHY_1000BT_FEATURES);
        else if (adv & PHY_100BT_FEATURES)
                phydev->advertising &= ~PHY_1000BT_FEATURES;

        if (phydev->advertising == adv_old)
                return 0;

        ret = phy_config_aneg(phydev);
        if (ret)
                return ret;

        return sync ? phy_poll_aneg_done(phydev) : 0;
}
EXPORT_SYMBOL_GPL(phy_speed_down);

/**
 * phy_speed_up - (re)set advertised speeds to all supported speeds
 * @phydev: the phy_device struct
 *
 * Description: Used to revert the effect of phy_speed_down
 */
int phy_speed_up(struct phy_device *phydev)
{
        u32 mask = PHY_10BT_FEATURES | PHY_100BT_FEATURES | PHY_1000BT_FEATURES;
        u32 adv_old = phydev->advertising;

        if (phydev->autoneg != AUTONEG_ENABLE)
                return 0;

        phydev->advertising = (adv_old & ~mask) | (phydev->supported & mask);

        if (phydev->advertising == adv_old)
                return 0;

        return phy_config_aneg(phydev);
}
EXPORT_SYMBOL_GPL(phy_speed_up);

/**
 * phy_start_machine - start PHY state machine tracking
 * @phydev: the phy_device struct
 *
 * Description: The PHY infrastructure can run a state machine
 *   which tracks whether the PHY is starting up, negotiating,
 *   etc.  This function starts the timer which tracks the state
 *   of the PHY.  If you want to maintain your own state machine,
 *   do not call this function.
 */
void phy_start_machine(struct phy_device *phydev)
{
        queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, HZ);
}

/**
 * phy_trigger_machine - trigger the state machine to run
 *
 * @phydev: the phy_device struct
 * @sync: indicate whether we should wait for the workqueue cancelation
 *
 * Description: There has been a change in state which requires that the
 *   state machine runs.
 */

static void phy_trigger_machine(struct phy_device *phydev, bool sync)
{
        if (sync)
                cancel_delayed_work_sync(&phydev->state_queue);
        else
                cancel_delayed_work(&phydev->state_queue);
        queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, 0);
}

/**
 * phy_stop_machine - stop the PHY state machine tracking
 * @phydev: target phy_device struct
 *
 * Description: Stops the state machine timer, sets the state to UP
 *   (unless it wasn't up yet). This function must be called BEFORE
 *   phy_detach.
 */
void phy_stop_machine(struct phy_device *phydev)
{
        cancel_delayed_work_sync(&phydev->state_queue);

        mutex_lock(&phydev->lock);
        if (phydev->state > PHY_UP)
                phydev->state = PHY_UP;
        mutex_unlock(&phydev->lock);
}

/**
 * phy_error - enter HALTED state for this PHY device
 * @phydev: target phy_device struct
 *
 * Moves the PHY to the HALTED state in response to a read
 * or write error, and tells the controller the link is down.
 * Must not be called from interrupt context, or while the
 * phydev->lock is held.
 */
static void phy_error(struct phy_device *phydev)
{
        mutex_lock(&phydev->lock);
        phydev->state = PHY_HALTED;
        mutex_unlock(&phydev->lock);

        phy_trigger_machine(phydev, false);
}

/**
 * phy_interrupt - PHY interrupt handler
 * @irq: interrupt line
 * @phy_dat: phy_device pointer
 *
 * 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 phy_device *phydev = phy_dat;

        if (PHY_HALTED == phydev->state)
                return IRQ_NONE;                /* It can't be ours.  */

        /* 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);
        atomic_inc(&phydev->irq_disable);

        queue_work(system_power_efficient_wq, &phydev->phy_queue);

        return IRQ_HANDLED;
}

/**
 * phy_enable_interrupts - Enable the interrupts from the PHY side
 * @phydev: target phy_device struct
 */
static int phy_enable_interrupts(struct phy_device *phydev)
{
        int err = phy_clear_interrupt(phydev);

        if (err < 0)
                return err;

        return phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
}

/**
 * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
 * @phydev: target phy_device struct
 */
static int phy_disable_interrupts(struct phy_device *phydev)
{
        int err;

        /* Disable PHY interrupts */
        err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
        if (err)
                goto phy_err;

        /* Clear the interrupt */
        err = phy_clear_interrupt(phydev);
        if (err)
                goto phy_err;

        return 0;

phy_err:
        phy_error(phydev);

        return err;
}

/**
 * phy_start_interrupts - request and enable interrupts for a PHY device
 * @phydev: target phy_device struct
 *
 * 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.
 *   This should only be called with a valid IRQ number.
 *   Returns 0 on success or < 0 on error.
 */
int phy_start_interrupts(struct phy_device *phydev)
{
        atomic_set(&phydev->irq_disable, 0);
        if (request_irq(phydev->irq, phy_interrupt,
                                IRQF_SHARED,
                                "phy_interrupt",
                                phydev) < 0) {
                pr_warn("%s: Can't get IRQ %d (PHY)\n",
                        phydev->mdio_bus->name, phydev->irq);
                phydev->irq = PHY_POLL;
                return 0;
        }

        return phy_enable_interrupts(phydev);
}
EXPORT_SYMBOL(phy_start_interrupts);

/**
 * phy_stop_interrupts - disable interrupts from a PHY device
 * @phydev: target phy_device struct
 */
int phy_stop_interrupts(struct phy_device *phydev)
{
        int err = phy_disable_interrupts(phydev);

        if (err)
                phy_error(phydev);

        free_irq(phydev->irq, phydev);

        /* Cannot call flush_scheduled_work() here as desired because
         * of rtnl_lock(), but we do not really care about what would
         * be done, except from enable_irq(), so cancel any work
         * possibly pending and take care of the matter below.
         */
        cancel_work_sync(&phydev->phy_queue);
        /* If work indeed has been cancelled, disable_irq() will have
         * been left unbalanced from phy_interrupt() and enable_irq()
         * has to be called so that other devices on the line work.
         */
        while (atomic_dec_return(&phydev->irq_disable) >= 0)
                enable_irq(phydev->irq);

        return err;
}
EXPORT_SYMBOL(phy_stop_interrupts);

/**
 * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
 * @work: work_struct that describes the work to be done
 */
void phy_change(struct work_struct *work)
{
        struct phy_device *phydev =
                container_of(work, struct phy_device, phy_queue);

        if (phy_interrupt_is_valid(phydev)) {
                if (phydev->drv->did_interrupt &&
                    !phydev->drv->did_interrupt(phydev))
                        goto ignore;

                if (phy_disable_interrupts(phydev))
                        goto phy_err;
        }

        mutex_lock(&phydev->lock);
        if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
                phydev->state = PHY_CHANGELINK;
        mutex_unlock(&phydev->lock);

        if (phy_interrupt_is_valid(phydev)) {
                atomic_dec(&phydev->irq_disable);
                enable_irq(phydev->irq);

                /* Reenable interrupts */
                if (PHY_HALTED != phydev->state &&
                    phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED))
                        goto irq_enable_err;
        }

        /* reschedule state queue work to run as soon as possible */
        phy_trigger_machine(phydev, true);
        return;

ignore:
        atomic_dec(&phydev->irq_disable);
        enable_irq(phydev->irq);
        return;

irq_enable_err:
        disable_irq(phydev->irq);
        atomic_inc(&phydev->irq_disable);
phy_err:
        phy_error(phydev);
}

/**
 * phy_stop - Bring down the PHY link, and stop checking the status
 * @phydev: target phy_device struct
 */
void phy_stop(struct phy_device *phydev)
{
        mutex_lock(&phydev->lock);

        if (PHY_HALTED == phydev->state)
                goto out_unlock;

        if (phy_interrupt_is_valid(phydev)) {
                /* Disable PHY Interrupts */
                phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);

                /* Clear any pending interrupts */
                phy_clear_interrupt(phydev);
        }

        phydev->state = PHY_HALTED;

out_unlock:
        mutex_unlock(&phydev->lock);

        /* Cannot call flush_scheduled_work() here as desired because
         * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
         * will not reenable interrupts.
         */
}
EXPORT_SYMBOL(phy_stop);

/**
 * phy_start - start or restart a PHY device
 * @phydev: target phy_device struct
 *
 * 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)
{
        int err = 0;

        mutex_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:
                /* if phy was suspended, bring the physical link up again */
                __phy_resume(phydev);

                /* make sure interrupts are re-enabled for the PHY */
                err = phy_enable_interrupts(phydev);
                if (err < 0)
                        break;

                phydev->state = PHY_RESUMING;
                break;
        default:
                break;
        }
        mutex_unlock(&phydev->lock);

        phy_trigger_machine(phydev, true);
}
EXPORT_SYMBOL(phy_start);

/**
 * phy_state_machine - Handle the state machine
 * @work: work_struct that describes the work to be done
 */
void phy_state_machine(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct phy_device *phydev =
                        container_of(dwork, struct phy_device, state_queue);
        bool needs_aneg = false, do_suspend = false;
        int err = 0;
        int old_link;

        mutex_lock(&phydev->lock);

        switch (phydev->state) {
        case PHY_DOWN:
        case PHY_STARTING:
        case PHY_READY:
        case PHY_PENDING:
                break;
        case PHY_UP:
                needs_aneg = true;

                phydev->link_timeout = PHY_AN_TIMEOUT;

                break;
        case PHY_AN:
                err = phy_read_status(phydev);
                if (err < 0)
                        break;

                /* If the link is down, give up on negotiation for now */
                if (!phydev->link) {
                        phydev->state = PHY_NOLINK;
                        netif_carrier_off(phydev->attached_dev);
                        phydev->adjust_link(phydev->attached_dev);
                        break;
                }

                /* Check if negotiation is done.  Break if there's an error */
                err = phy_aneg_done(phydev);
                if (err < 0)
                        break;

                /* If AN is done, we're running */
                if (err > 0) {
                        phydev->state = PHY_RUNNING;
                        netif_carrier_on(phydev->attached_dev);
                        phydev->adjust_link(phydev->attached_dev);

                } else if (0 == phydev->link_timeout--)
                        needs_aneg = true;
                break;
        case PHY_NOLINK:
                err = phy_read_status(phydev);
                if (err)
                        break;

                if (phydev->link) {
                        if (AUTONEG_ENABLE == phydev->autoneg) {
                                err = phy_aneg_done(phydev);
                                if (err < 0)
                                        break;

                                if (!err) {
                                        phydev->state = PHY_AN;
                                        phydev->link_timeout = PHY_AN_TIMEOUT;
                                        break;

                                }
                        }
                        phydev->state = PHY_RUNNING;
                        netif_carrier_on(phydev->attached_dev);
                        phydev->adjust_link(phydev->attached_dev);
                }
                break;
        case PHY_FORCING:
                err = genphy_update_link(phydev);
                if (err)
                        break;

                if (phydev->link) {
                        phydev->state = PHY_RUNNING;
                        netif_carrier_on(phydev->attached_dev);
                } else {
                        if (0 == phydev->link_timeout--)
                                needs_aneg = true;
                }

                phydev->adjust_link(phydev->attached_dev);
                break;
        case PHY_RUNNING:
                /* Only register a CHANGE if we are polling and link changed
                 * since latest checking.
                 */
                if (phydev->irq == PHY_POLL) {
                        old_link = phydev->link;
                        err = phy_read_status(phydev);
                        if (err)
                                break;

                        if (old_link != phydev->link)
                                phydev->state = PHY_CHANGELINK;
                }
                break;
        case PHY_CHANGELINK:
                err = phy_read_status(phydev);
                if (err)
                        break;

                if (phydev->link) {
                        phydev->state = PHY_RUNNING;
                        netif_carrier_on(phydev->attached_dev);
                } else {
                        phydev->state = PHY_NOLINK;
                        netif_carrier_off(phydev->attached_dev);
                }

                phydev->adjust_link(phydev->attached_dev);

                if (phy_interrupt_is_valid(phydev))
                        err = phy_config_interrupt(phydev,
                                                   PHY_INTERRUPT_ENABLED);
                break;
        case PHY_HALTED:
                if (phydev->link) {
                        phydev->link = 0;
                        netif_carrier_off(phydev->attached_dev);
                        phydev->adjust_link(phydev->attached_dev);
                        do_suspend = true;
                }
                break;
        case PHY_RESUMING:
                if (AUTONEG_ENABLE == phydev->autoneg) {
                        err = phy_aneg_done(phydev);
                        if (err < 0)
                                break;

                        /* err > 0 if AN is done.
                         * Otherwise, it's 0, and we're  still waiting for AN
                         */
                        if (err > 0) {
                                err = phy_read_status(phydev);
                                if (err)
                                        break;

                                if (phydev->link) {
                                        phydev->state = PHY_RUNNING;
                                        netif_carrier_on(phydev->attached_dev);
                                } else  {
                                        phydev->state = PHY_NOLINK;
                                }
                                phydev->adjust_link(phydev->attached_dev);
                        } else {
                                phydev->state = PHY_AN;
                                phydev->link_timeout = PHY_AN_TIMEOUT;
                        }
                } else {
                        err = phy_read_status(phydev);
                        if (err)
                                break;

                        if (phydev->link) {
                                phydev->state = PHY_RUNNING;
                                netif_carrier_on(phydev->attached_dev);
                        } else  {
                                phydev->state = PHY_NOLINK;
                        }
                        phydev->adjust_link(phydev->attached_dev);
                }
                break;
        }

        mutex_unlock(&phydev->lock);

        if (needs_aneg)
                err = phy_start_aneg(phydev);
        else if (do_suspend)
                phy_suspend(phydev);

        if (err < 0)
                phy_error(phydev);

        /* Only re-schedule a PHY state machine change if we are polling the
         * PHY, if PHY_IGNORE_INTERRUPT is set, then we will be moving
         * between states from phy_mac_interrupt()
         */
        if (phydev->irq == PHY_POLL)
                queue_delayed_work(system_power_efficient_wq, &phydev->state_queue,
                                   PHY_STATE_TIME * HZ);
}

/**
 * phy_mac_interrupt - MAC says the link has changed
 * @phydev: phy_device struct with changed link
 *
 * The MAC layer is able to indicate there has been a change in the PHY link
 * status. Trigger the state machine and work a work queue.
 */
void phy_mac_interrupt(struct phy_device *phydev)
{
        /* Trigger a state machine change */
        queue_work(system_power_efficient_wq, &phydev->phy_queue);
}
EXPORT_SYMBOL(phy_mac_interrupt);

/**
 * phy_init_eee - init and check the EEE feature
 * @phydev: target phy_device struct
 * @clk_stop_enable: PHY may stop the clock during LPI
 *
 * Description: it checks if the Energy-Efficient Ethernet (EEE)
 * is supported by looking at the MMD registers 3.20 and 7.60/61
 * and it programs the MMD register 3.0 setting the "Clock stop enable"
 * bit if required.
 */
int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
{
        if (!phydev->drv)
                return -EIO;

        /* According to 802.3az,the EEE is supported only in full duplex-mode.
         * Also EEE feature is active when core is operating with MII, GMII
         * or RGMII. Internal PHYs are also allowed to proceed and should
         * return an error if they do not support EEE.
         */
        if ((phydev->duplex == DUPLEX_FULL) &&
            ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
            (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
            (phydev->interface == PHY_INTERFACE_MODE_RGMII) ||
             phy_is_internal(phydev))) {
                int eee_lp, eee_cap, eee_adv;
                u32 lp, cap, adv;
                int idx, status;

                /* Read phy status to properly get the right settings */
                status = phy_read_status(phydev);
                if (status)
                        return status;

                /* First check if the EEE ability is supported */
                eee_cap = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_ABLE);
                if (eee_cap <= 0)
                        goto eee_exit_err;

                cap = mmd_eee_cap_to_ethtool_sup_t(eee_cap);
                if (!cap)
                        goto eee_exit_err;

                /* Check which link settings negotiated and verify it in
                 * the EEE advertising registers.
                 */
                eee_lp = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_LPABLE);
                if (eee_lp <= 0)
                        goto eee_exit_err;

                eee_adv = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
                if (eee_adv <= 0)
                        goto eee_exit_err;

                adv = mmd_eee_adv_to_ethtool_adv_t(eee_adv);
                lp = mmd_eee_adv_to_ethtool_adv_t(eee_lp);
                idx = phy_find_setting(phydev->speed, phydev->duplex);
                if (!(lp & adv & settings[idx].setting))
                        goto eee_exit_err;

                if (clk_stop_enable)
                        /* Configure the PHY to stop receiving xMII
                         * clock while it is signaling LPI.
                         */
                        phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
                                         MDIO_PCS_CTRL1_CLKSTOP_EN);

                return 0; /* EEE supported */
        }
eee_exit_err:
        return -EPROTONOSUPPORT;
}
EXPORT_SYMBOL(phy_init_eee);

/**
 * phy_get_eee_err - report the EEE wake error count
 * @phydev: target phy_device struct
 *
 * Description: it is to report the number of time where the PHY
 * failed to complete its normal wake sequence.
 */
int phy_get_eee_err(struct phy_device *phydev)
{
        if (!phydev->drv)
                return -EIO;

        return phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_WK_ERR);
}
EXPORT_SYMBOL(phy_get_eee_err);

/**
 * phy_ethtool_get_eee - get EEE supported and status
 * @phydev: target phy_device struct
 * @data: ethtool_eee data
 *
 * Description: it reportes the Supported/Advertisement/LP Advertisement
 * capabilities.
 */
int phy_ethtool_get_eee(struct phy_device *phydev, struct ethtool_eee *data)
{
        int val;

        if (!phydev->drv)
                return -EIO;

        /* Get Supported EEE */
        val = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_ABLE);
        if (val < 0)
                return val;
        data->supported = mmd_eee_cap_to_ethtool_sup_t(val);

        /* Get advertisement EEE */
        val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
        if (val < 0)
                return val;
        data->advertised = mmd_eee_adv_to_ethtool_adv_t(val);

        /* Get LP advertisement EEE */
        val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_LPABLE);
        if (val < 0)
                return val;
        data->lp_advertised = mmd_eee_adv_to_ethtool_adv_t(val);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_get_eee);

/**
 * phy_ethtool_set_eee - set EEE supported and status
 * @phydev: target phy_device struct
 * @data: ethtool_eee data
 *
 * Description: it is to program the Advertisement EEE register.
 */
int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
{
        int cap, old_adv, adv, ret;

        if (!phydev->drv)
                return -EIO;

        /* Get Supported EEE */
        cap = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_ABLE);
        if (cap < 0)
                return cap;

        old_adv = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
        if (old_adv < 0)
                return old_adv;

        adv = ethtool_adv_to_mmd_eee_adv_t(data->advertised) & cap;

        /* Mask prohibited EEE modes */
        adv &= ~phydev->eee_broken_modes;

        if (old_adv != adv) {
                ret = phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
                if (ret < 0)
                        return ret;

                /* Restart autonegotiation so the new modes get sent to the
                 * link partner.
                 */
                ret = phy_restart_aneg(phydev);
                if (ret < 0)
                        return ret;
        }

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_set_eee);

int phy_ethtool_set_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol)
{
        if (phydev->drv && phydev->drv->set_wol)
                return phydev->drv->set_wol(phydev, wol);

        return -EOPNOTSUPP;
}
EXPORT_SYMBOL(phy_ethtool_set_wol);

void phy_ethtool_get_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol)
{
        if (phydev->drv && phydev->drv->get_wol)
                phydev->drv->get_wol(phydev, wol);
}
EXPORT_SYMBOL(phy_ethtool_get_wol);

int phy_ethtool_get_link_ksettings(struct net_device *ndev,
                                   struct ethtool_link_ksettings *cmd)
{
        struct phy_device *phydev = ndev->phydev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_ksettings_get(phydev, cmd);
}
EXPORT_SYMBOL(phy_ethtool_get_link_ksettings);

int phy_ethtool_set_link_ksettings(struct net_device *ndev,
                                   const struct ethtool_link_ksettings *cmd)
{
        struct phy_device *phydev = ndev->phydev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_ksettings_set(phydev, cmd);
}
EXPORT_SYMBOL(phy_ethtool_set_link_ksettings);

int phy_ethtool_nway_reset(struct net_device *ndev)
{
        struct phy_device *phydev = ndev->phydev;

        if (!phydev)
                return -ENODEV;

        if (!phydev->drv)
                return -EIO;

        return phy_restart_aneg(phydev);
}
EXPORT_SYMBOL(phy_ethtool_nway_reset);