/*
 * drivers/net/phy/phy.c
 *
 * 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/atomic.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.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->dev),
                        phydev->speed,
                        DUPLEX_FULL == phydev->duplex ? "Full" : "Half");
        else
                pr_info("%s - Link is Down\n", dev_name(&phydev->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)
{
        int err = 0;

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

        return err;
}

/**
 * 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)
{
        int err = 0;

        phydev->interrupts = interrupts;
        if (phydev->drv->config_intr)
                err = phydev->drv->config_intr(phydev);

        return err;
}


/**
 * phy_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.
 */
static inline int phy_aneg_done(struct phy_device *phydev)
{
        int retval;

        retval = phy_read(phydev, MII_BMSR);

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

/* 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->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;

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

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_sset);

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

        cmd->advertising = phydev->advertising;

        ethtool_cmd_speed_set(cmd, phydev->speed);
        cmd->duplex = phydev->duplex;
        cmd->port = PORT_MII;
        cmd->phy_address = phydev->addr;
        cmd->transceiver = XCVR_EXTERNAL;
        cmd->autoneg = phydev->autoneg;

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_gset);

/**
 * 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->addr;
                /* fall through */

        case SIOCGMIIREG:
                mii_data->val_out = mdiobus_read(phydev->bus, mii_data->phy_id,
                                                 mii_data->reg_num);
                break;

        case SIOCSMIIREG:
                if (mii_data->phy_id == phydev->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->bus, mii_data->phy_id,
                              mii_data->reg_num, val);

                if (mii_data->reg_num == MII_BMCR &&
                    val & BMCR_RESET &&
                    phydev->drv->config_init) {
                        phy_scan_fixups(phydev);
                        phydev->drv->config_init(phydev);
                }
                break;

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

        default:
                return -EOPNOTSUPP;
        }

        return 0;
}
EXPORT_SYMBOL(phy_mii_ioctl);

/**
 * 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;

        mutex_lock(&phydev->lock);

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

        err = phydev->drv->config_aneg(phydev);

        if (err < 0)
                goto out_unlock;

        if (phydev->state != PHY_HALTED) {
                if (AUTONEG_ENABLE == phydev->autoneg) {
                        phydev->state = PHY_AN;
                        phydev->link_timeout = PHY_AN_TIMEOUT;
                } else {
                        phydev->state = PHY_FORCING;
                        phydev->link_timeout = PHY_FORCE_TIMEOUT;
                }
        }

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


static void phy_change(struct work_struct *work);

/**
 * phy_start_machine - start PHY state machine tracking
 * @phydev: the phy_device struct
 * @handler: callback function for state change notifications
 *
 * 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 be notified when the state changes,
 *   pass in the callback @handler, otherwise, pass NULL.  If you
 *   want to maintain your own state machine, do not call this
 *   function.
 */
void phy_start_machine(struct phy_device *phydev,
                void (*handler)(struct net_device *))
{
        phydev->adjust_state = handler;

        schedule_delayed_work(&phydev->state_queue, HZ);
}

/**
 * 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);

        phydev->adjust_state = NULL;
}

/**
 * phy_force_reduction - reduce PHY speed/duplex settings by one step
 * @phydev: target phy_device struct
 *
 * Description: Reduces the speed/duplex settings by one notch,
 *   in this order--
 *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
 *   The function bottoms out at 10/HALF.
 */
static void phy_force_reduction(struct phy_device *phydev)
{
        int idx;

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

        idx = phy_find_valid(idx, phydev->supported);

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

        pr_info("Trying %d/%s\n",
                phydev->speed, DUPLEX_FULL == phydev->duplex ? "FULL" : "HALF");
}


/**
 * phy_error - 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_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);

        schedule_work(&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;

        err = phy_clear_interrupt(phydev);

        if (err < 0)
                return err;

        err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);

        return err;
}

/**
 * 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)
{
        int err = 0;

        INIT_WORK(&phydev->phy_queue, phy_change);

        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->bus->name, phydev->irq);
                phydev->irq = PHY_POLL;
                return 0;
        }

        err = phy_enable_interrupts(phydev);

        return err;
}
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;

        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
 */
static void phy_change(struct work_struct *work)
{
        int err;
        struct phy_device *phydev =
                container_of(work, struct phy_device, phy_queue);

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

        err = phy_disable_interrupts(phydev);

        if (err)
                goto phy_err;

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

        atomic_dec(&phydev->irq_disable);
        enable_irq(phydev->irq);

        /* Reenable interrupts */
        if (PHY_HALTED != phydev->state)
                err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);

        if (err)
                goto irq_enable_err;

        /* reschedule state queue work to run as soon as possible */
        cancel_delayed_work_sync(&phydev->state_queue);
        schedule_delayed_work(&phydev->state_queue, 0);

        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 (phydev->irq != PHY_POLL) {
                /* 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.
         */
}


/**
 * 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)
{
        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:
                        phydev->state = PHY_RESUMING;
                default:
                        break;
        }
        mutex_unlock(&phydev->lock);
}
EXPORT_SYMBOL(phy_stop);
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);
        int needs_aneg = 0;
        int err = 0;

        mutex_lock(&phydev->lock);

        if (phydev->adjust_state)
                phydev->adjust_state(phydev->attached_dev);

        switch(phydev->state) {
                case PHY_DOWN:
                case PHY_STARTING:
                case PHY_READY:
                case PHY_PENDING:
                        break;
                case PHY_UP:
                        needs_aneg = 1;

                        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--) {
                                int idx;

                                needs_aneg = 1;
                                /* If we have the magic_aneg bit,
                                 * we try again */
                                if (phydev->drv->flags & PHY_HAS_MAGICANEG)
                                        break;

                                /* The timer expired, and we still
                                 * don't have a setting, so we try
                                 * forcing it until we find one that
                                 * works, starting from the fastest speed,
                                 * and working our way down */
                                idx = phy_find_valid(0, phydev->supported);

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

                                phydev->autoneg = AUTONEG_DISABLE;

                                pr_info("Trying %d/%s\n",
                                        phydev->speed,
                                        DUPLEX_FULL == phydev->duplex ?
                                        "FULL" : "HALF");
                        }
                        break;
                case PHY_NOLINK:
                        err = phy_read_status(phydev);

                        if (err)
                                break;

                        if (phydev->link) {
                                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--) {
                                        phy_force_reduction(phydev);
                                        needs_aneg = 1;
                                }
                        }

                        phydev->adjust_link(phydev->attached_dev);
                        break;
                case PHY_RUNNING:
                        /* Only register a CHANGE if we are
                         * polling */
                        if (PHY_POLL == phydev->irq)
                                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_POLL != phydev->irq)
                                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);
                        }
                        break;
                case PHY_RESUMING:

                        err = phy_clear_interrupt(phydev);

                        if (err)
                                break;

                        err = phy_config_interrupt(phydev,
                                        PHY_INTERRUPT_ENABLED);

                        if (err)
                                break;

                        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);

        if (err < 0)
                phy_error(phydev);

        schedule_delayed_work(&phydev->state_queue, PHY_STATE_TIME * HZ);
}

static inline void mmd_phy_indirect(struct mii_bus *bus, int prtad, int devad,
                                    int addr)
{
        /* Write the desired MMD Devad */
        bus->write(bus, addr, MII_MMD_CTRL, devad);

        /* Write the desired MMD register address */
        bus->write(bus, addr, MII_MMD_DATA, prtad);

        /* Select the Function : DATA with no post increment */
        bus->write(bus, addr, MII_MMD_CTRL, (devad | MII_MMD_CTRL_NOINCR));
}

/**
 * phy_read_mmd_indirect - reads data from the MMD registers
 * @bus: the target MII bus
 * @prtad: MMD Address
 * @devad: MMD DEVAD
 * @addr: PHY address on the MII bus
 *
 * Description: it reads data from the MMD registers (clause 22 to access to
 * clause 45) of the specified phy address.
 * To read these register we have:
 * 1) Write reg 13 // DEVAD
 * 2) Write reg 14 // MMD Address
 * 3) Write reg 13 // MMD Data Command for MMD DEVAD
 * 3) Read  reg 14 // Read MMD data
 */
static int phy_read_mmd_indirect(struct mii_bus *bus, int prtad, int devad,

                                 int addr)
{
        u32 ret;

        mmd_phy_indirect(bus, prtad, devad, addr);

        /* Read the content of the MMD's selected register */
        ret = bus->read(bus, addr, MII_MMD_DATA);

        return ret;
}

/**
 * phy_write_mmd_indirect - writes data to the MMD registers
 * @bus: the target MII bus
 * @prtad: MMD Address
 * @devad: MMD DEVAD
 * @addr: PHY address on the MII bus
 * @data: data to write in the MMD register
 *
 * Description: Write data from the MMD registers of the specified
 * phy address.
 * To write these register we have:
 * 1) Write reg 13 // DEVAD
 * 2) Write reg 14 // MMD Address
 * 3) Write reg 13 // MMD Data Command for MMD DEVAD
 * 3) Write reg 14 // Write MMD data
 */
static void phy_write_mmd_indirect(struct mii_bus *bus, int prtad, int devad,
                                   int addr, u32 data)
{
        mmd_phy_indirect(bus, prtad, devad, addr);

        /* Write the data into MMD's selected register */
        bus->write(bus, addr, MII_MMD_DATA, data);
}

static u32 phy_eee_to_adv(u16 eee_adv)
{
        u32 adv = 0;

        if (eee_adv & MDIO_EEE_100TX)
                adv |= ADVERTISED_100baseT_Full;
        if (eee_adv & MDIO_EEE_1000T)
                adv |= ADVERTISED_1000baseT_Full;
        if (eee_adv & MDIO_EEE_10GT)
                adv |= ADVERTISED_10000baseT_Full;
        if (eee_adv & MDIO_EEE_1000KX)
                adv |= ADVERTISED_1000baseKX_Full;
        if (eee_adv & MDIO_EEE_10GKX4)
                adv |= ADVERTISED_10000baseKX4_Full;
        if (eee_adv & MDIO_EEE_10GKR)
                adv |= ADVERTISED_10000baseKR_Full;

        return adv;
}

static u32 phy_eee_to_supported(u16 eee_caported)
{
        u32 supported = 0;

        if (eee_caported & MDIO_EEE_100TX)
                supported |= SUPPORTED_100baseT_Full;
        if (eee_caported & MDIO_EEE_1000T)
                supported |= SUPPORTED_1000baseT_Full;
        if (eee_caported & MDIO_EEE_10GT)
                supported |= SUPPORTED_10000baseT_Full;
        if (eee_caported & MDIO_EEE_1000KX)
                supported |= SUPPORTED_1000baseKX_Full;
        if (eee_caported & MDIO_EEE_10GKX4)
                supported |= SUPPORTED_10000baseKX4_Full;
        if (eee_caported & MDIO_EEE_10GKR)
                supported |= SUPPORTED_10000baseKR_Full;

        return supported;
}

static u16 phy_adv_to_eee(u32 adv)
{
        u16 reg = 0;

        if (adv & ADVERTISED_100baseT_Full)
                reg |= MDIO_EEE_100TX;
        if (adv & ADVERTISED_1000baseT_Full)
                reg |= MDIO_EEE_1000T;
        if (adv & ADVERTISED_10000baseT_Full)
                reg |= MDIO_EEE_10GT;
        if (adv & ADVERTISED_1000baseKX_Full)
                reg |= MDIO_EEE_1000KX;
        if (adv & ADVERTISED_10000baseKX4_Full)
                reg |= MDIO_EEE_10GKX4;
        if (adv & ADVERTISED_10000baseKR_Full)
                reg |= MDIO_EEE_10GKR;

        return reg;
}

/**
 * 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)
{
        int ret = -EPROTONOSUPPORT;

        /* 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.
         */
        if ((phydev->duplex == DUPLEX_FULL) &&
            ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
            (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
            (phydev->interface == PHY_INTERFACE_MODE_RGMII))) {
                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_indirect(phydev->bus, MDIO_PCS_EEE_ABLE,
                                                MDIO_MMD_PCS, phydev->addr);
                if (eee_cap < 0)
                        return eee_cap;

                cap = phy_eee_to_supported(eee_cap);
                if (!cap)
                        goto eee_exit;

                /* Check which link settings negotiated and verify it in
                 * the EEE advertising registers.
                 */
                eee_lp = phy_read_mmd_indirect(phydev->bus, MDIO_AN_EEE_LPABLE,
                                               MDIO_MMD_AN, phydev->addr);
                if (eee_lp < 0)
                        return eee_lp;

                eee_adv = phy_read_mmd_indirect(phydev->bus, MDIO_AN_EEE_ADV,
                                                MDIO_MMD_AN, phydev->addr);
                if (eee_adv < 0)
                        return eee_adv;

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

                if (clk_stop_enable) {
                        /* Configure the PHY to stop receiving xMII
                         * clock while it is signaling LPI.
                         */
                        int val = phy_read_mmd_indirect(phydev->bus, MDIO_CTRL1,
                                                        MDIO_MMD_PCS,
                                                        phydev->addr);
                        if (val < 0)
                                return val;

                        val |= MDIO_PCS_CTRL1_CLKSTOP_EN;
                        phy_write_mmd_indirect(phydev->bus, MDIO_CTRL1,
                                               MDIO_MMD_PCS, phydev->addr, val);
                }

                ret = 0; /* EEE supported */
        }

eee_exit:
        return ret;
}
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)
{
        return phy_read_mmd_indirect(phydev->bus, MDIO_PCS_EEE_WK_ERR,
                                     MDIO_MMD_PCS, phydev->addr);

}
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;

        /* Get Supported EEE */
        val = phy_read_mmd_indirect(phydev->bus, MDIO_PCS_EEE_ABLE,
                                    MDIO_MMD_PCS, phydev->addr);
        if (val < 0)
                return val;
        data->supported = phy_eee_to_supported(val);

        /* Get advertisement EEE */
        val = phy_read_mmd_indirect(phydev->bus, MDIO_AN_EEE_ADV,
                                    MDIO_MMD_AN, phydev->addr);
        if (val < 0)
                return val;
        data->advertised = phy_eee_to_adv(val);

        /* Get LP advertisement EEE */
        val = phy_read_mmd_indirect(phydev->bus, MDIO_AN_EEE_LPABLE,
                                    MDIO_MMD_AN, phydev->addr);
        if (val < 0)
                return val;
        data->lp_advertised = phy_eee_to_adv(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 val;

        val = phy_adv_to_eee(data->advertised);
        phy_write_mmd_indirect(phydev->bus, MDIO_AN_EEE_ADV, MDIO_MMD_AN,
                               phydev->addr, val);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_set_eee);