// SPDX-License-Identifier: GPL-2.0+
/* 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
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/interrupt.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/phy_led_triggers.h>
#include <linux/workqueue.h>
#include <linux/mdio.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>

#define PHY_STATE_STR(_state)                   \
        case PHY_##_state:                      \
                return __stringify(_state);     \

static const char *phy_state_to_str(enum phy_state st)
{
        switch (st) {
        PHY_STATE_STR(DOWN)
        PHY_STATE_STR(READY)
        PHY_STATE_STR(UP)
        PHY_STATE_STR(RUNNING)
        PHY_STATE_STR(NOLINK)
        PHY_STATE_STR(FORCING)
        PHY_STATE_STR(HALTED)
        }

        return NULL;
}

static void phy_link_up(struct phy_device *phydev)
{
        phydev->phy_link_change(phydev, true, true);
        phy_led_trigger_change_speed(phydev);
}

static void phy_link_down(struct phy_device *phydev, bool do_carrier)
{
        phydev->phy_link_change(phydev, false, do_carrier);
        phy_led_trigger_change_speed(phydev);
}

static const char *phy_pause_str(struct phy_device *phydev)
{
        bool local_pause, local_asym_pause;

        if (phydev->autoneg == AUTONEG_DISABLE)
                goto no_pause;

        local_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
                                        phydev->advertising);
        local_asym_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
                                             phydev->advertising);

        if (local_pause && phydev->pause)
                return "rx/tx";

        if (local_asym_pause && phydev->asym_pause) {
                if (local_pause)
                        return "rx";
                if (phydev->pause)
                        return "tx";
        }

no_pause:
        return "off";
}

/**
 * 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) {
                netdev_info(phydev->attached_dev,
                        "Link is Up - %s/%s - flow control %s\n",
                        phy_speed_to_str(phydev->speed),
                        phy_duplex_to_str(phydev->duplex),
                        phy_pause_str(phydev));
        } else  {
                netdev_info(phydev->attached_dev, "Link is Down\n");
        }
}
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 or < 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 or < 0 on error.
 */
static int phy_config_interrupt(struct phy_device *phydev, bool interrupts)
{
        phydev->interrupts = interrupts ? 1 : 0;
        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);
        else if (phydev->is_c45)
                return genphy_c45_aneg_done(phydev);
        else
                return genphy_aneg_done(phydev);
}
EXPORT_SYMBOL(phy_aneg_done);

/**
 * phy_find_valid - find a PHY setting that matches the requested parameters
 * @speed: desired speed
 * @duplex: desired duplex
 * @supported: mask of supported link modes
 *
 * Locate a supported phy setting that is, in priority order:
 * - an exact match for the specified speed and duplex mode
 * - a match for the specified speed, or slower speed
 * - the slowest supported speed
 * Returns the matched phy_setting entry, or %NULL if no supported phy
 * settings were found.
 */
static const struct phy_setting *
phy_find_valid(int speed, int duplex, unsigned long *supported)
{
        return phy_lookup_setting(speed, duplex, supported, false);
}

/**
 * phy_supported_speeds - return all speeds currently supported by a phy device
 * @phy: The phy device to return supported speeds of.
 * @speeds: buffer to store supported speeds in.
 * @size:   size of speeds buffer.
 *
 * Description: Returns the number of supported speeds, and fills the speeds
 * buffer with the supported speeds. If speeds buffer is too small to contain
 * all currently supported speeds, will return as many speeds as can fit.
 */
unsigned int phy_supported_speeds(struct phy_device *phy,
                                  unsigned int *speeds,
                                  unsigned int size)
{
        return phy_speeds(speeds, size, phy->supported);
}

/**
 * phy_check_valid - check if there is a valid PHY setting which matches
 *                   speed, duplex, and feature mask
 * @speed: speed to match
 * @duplex: duplex to match
 * @features: A mask of the valid settings
 *
 * Description: Returns true if there is a valid setting, false otherwise.
 */
static inline bool phy_check_valid(int speed, int duplex,
                                   unsigned long *features)
{
        return !!phy_lookup_setting(speed, duplex, features, true);
}

/**
 * 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)
{
        const struct phy_setting *setting;

        setting = phy_find_valid(phydev->speed, phydev->duplex,
                                 phydev->supported);
        if (setting) {
                phydev->speed = setting->speed;
                phydev->duplex = setting->duplex;
        } else {
                /* We failed to find anything (no supported speeds?) */
                phydev->speed = SPEED_UNKNOWN;
                phydev->duplex = DUPLEX_UNKNOWN;
        }
}

/**
 * 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)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(advertising);
        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 */
        ethtool_convert_legacy_u32_to_link_mode(advertising, cmd->advertising);
        linkmode_and(advertising, 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;

        linkmode_copy(phydev->advertising, advertising);

        if (AUTONEG_ENABLE == cmd->autoneg)
                linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                 phydev->advertising);
        else
                linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                   phydev->advertising);

        phydev->duplex = cmd->duplex;

        phydev->mdix_ctrl = 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)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(advertising);
        u8 autoneg = cmd->base.autoneg;
        u8 duplex = cmd->base.duplex;
        u32 speed = cmd->base.speed;

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

        linkmode_copy(advertising, cmd->link_modes.advertising);

        /* We make sure that we don't pass unsupported values in to the PHY */
        linkmode_and(advertising, advertising, phydev->supported);

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

        if (autoneg == AUTONEG_ENABLE && linkmode_empty(advertising))
                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;

        linkmode_copy(phydev->advertising, advertising);

        if (autoneg == AUTONEG_ENABLE)
                linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                 phydev->advertising);
        else
                linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                   phydev->advertising);

        phydev->duplex = duplex;

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

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

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_ksettings_set);

void phy_ethtool_ksettings_get(struct phy_device *phydev,
                               struct ethtool_link_ksettings *cmd)
{
        linkmode_copy(cmd->link_modes.supported, phydev->supported);
        linkmode_copy(cmd->link_modes.advertising, phydev->advertising);
        linkmode_copy(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_ctrl;
        cmd->base.eth_tp_mdix = phydev->mdix;
}
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;
        bool change_autoneg = false;

        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) {
                                        if (phydev->autoneg == AUTONEG_ENABLE)
                                                change_autoneg = true;
                                        phydev->autoneg = AUTONEG_DISABLE;
                                        if (val & BMCR_FULLDPLX)
                                                phydev->duplex = DUPLEX_FULL;
                                        else
                                                phydev->duplex = DUPLEX_HALF;
                                        if (val & BMCR_SPEED1000)
                                                phydev->speed = SPEED_1000;
                                        else if (val & BMCR_SPEED100)
                                                phydev->speed = SPEED_100;
                                        else phydev->speed = SPEED_10;
                                }
                                else {
                                        if (phydev->autoneg == AUTONEG_DISABLE)
                                                change_autoneg = true;
                                        phydev->autoneg = AUTONEG_ENABLE;
                                }
                                break;
                        case MII_ADVERTISE:
                                mii_adv_mod_linkmode_adv_t(phydev->advertising,
                                                           val);
                                change_autoneg = true;
                                break;
                        case MII_CTRL1000:
                                mii_ctrl1000_mod_linkmode_adv_t(phydev->advertising,
                                                                val);
                                change_autoneg = true;
                                break;
                        default:
                                /* do nothing */
                                break;
                        }
                }

                mdiobus_write(phydev->mdio.bus, mii_data->phy_id,
                              mii_data->reg_num, val);

                if (mii_data->phy_id == phydev->mdio.addr &&
                    mii_data->reg_num == MII_BMCR &&
                    val & BMCR_RESET)
                        return phy_init_hw(phydev);

                if (change_autoneg)
                        return phy_start_aneg(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 void phy_queue_state_machine(struct phy_device *phydev,
                                    unsigned int secs)
{
        mod_delayed_work(system_power_efficient_wq, &phydev->state_queue,
                         secs * HZ);
}

static void phy_trigger_machine(struct phy_device *phydev)
{
        phy_queue_state_machine(phydev, 0);
}

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

        /* Clause 45 PHYs that don't implement Clause 22 registers are not
         * allowed to call genphy_config_aneg()
         */
        if (phydev->is_c45 && !(phydev->c45_ids.devices_in_package & BIT(0)))
                return genphy_c45_config_aneg(phydev);

        return genphy_config_aneg(phydev);
}

/**
 * phy_check_link_status - check link status and set state accordingly
 * @phydev: the phy_device struct
 *
 * Description: Check for link and whether autoneg was triggered / is running
 * and set state accordingly
 */
static int phy_check_link_status(struct phy_device *phydev)
{
        int err;

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

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

        if (phydev->link && phydev->state != PHY_RUNNING) {
                phydev->state = PHY_RUNNING;
                phy_link_up(phydev);
        } else if (!phydev->link && phydev->state != PHY_NOLINK) {
                phydev->state = PHY_NOLINK;
                phy_link_down(phydev, true);
        }

        return 0;
}

/**
 * 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 */
        linkmode_zero(phydev->lp_advertising);

        err = phy_config_aneg(phydev);
        if (err < 0)
                goto out_unlock;

        if (phy_is_started(phydev)) {
                if (phydev->autoneg == AUTONEG_ENABLE) {
                        err = phy_check_link_status(phydev);
                } 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)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(adv_old);
        __ETHTOOL_DECLARE_LINK_MODE_MASK(adv);
        int ret;

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

        linkmode_copy(adv_old, phydev->advertising);
        linkmode_copy(adv, phydev->lp_advertising);
        linkmode_and(adv, adv, phydev->supported);

        if (linkmode_test_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, adv) ||
            linkmode_test_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, adv)) {
                linkmode_clear_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
                                   phydev->advertising);
                linkmode_clear_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
                                   phydev->advertising);
                linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
                                   phydev->advertising);
                linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
                                   phydev->advertising);
        } else if (linkmode_test_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
                                     adv) ||
                   linkmode_test_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
                                     adv)) {
                linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
                                   phydev->advertising);
                linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
                                   phydev->advertising);
        }

        if (linkmode_equal(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)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(all_speeds) = { 0, };
        __ETHTOOL_DECLARE_LINK_MODE_MASK(not_speeds);
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
        __ETHTOOL_DECLARE_LINK_MODE_MASK(adv_old);
        __ETHTOOL_DECLARE_LINK_MODE_MASK(speeds);

        linkmode_copy(adv_old, phydev->advertising);

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

        linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, all_speeds);
        linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, all_speeds);
        linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, all_speeds);
        linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, all_speeds);
        linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, all_speeds);
        linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, all_speeds);

        linkmode_andnot(not_speeds, adv_old, all_speeds);
        linkmode_copy(supported, phydev->supported);
        linkmode_and(speeds, supported, all_speeds);
        linkmode_or(phydev->advertising, not_speeds, speeds);

        if (linkmode_equal(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 delayed workqueue 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)
{
        phy_trigger_machine(phydev);
}
EXPORT_SYMBOL_GPL(phy_start_machine);

/**
 * phy_stop_machine - stop the PHY state machine tracking
 * @phydev: target phy_device struct
 *
 * Description: Stops the state machine delayed workqueue, 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 (phy_is_started(phydev))
                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)
{
        WARN_ON(1);

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

        phy_trigger_machine(phydev);
}

/**
 * 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)
                return err;

        /* Clear the interrupt */
        return phy_clear_interrupt(phydev);
}

/**
 * phy_interrupt - PHY interrupt handler
 * @irq: interrupt line
 * @phy_dat: phy_device pointer
 *
 * Description: Handle PHY interrupt
 */
static irqreturn_t phy_interrupt(int irq, void *phy_dat)
{
        struct phy_device *phydev = phy_dat;

        if (phydev->drv->did_interrupt && !phydev->drv->did_interrupt(phydev))
                return IRQ_NONE;

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

        if (phy_clear_interrupt(phydev))
                goto phy_err;
        return IRQ_HANDLED;

phy_err:
        phy_error(phydev);
        return IRQ_NONE;
}

/**
 * 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_request_interrupt - request interrupt 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.
 *   This should only be called with a valid IRQ number.
 */
void phy_request_interrupt(struct phy_device *phydev)
{
        int err;

        err = request_threaded_irq(phydev->irq, NULL, phy_interrupt,
                                   IRQF_ONESHOT | IRQF_SHARED,
                                   phydev_name(phydev), phydev);
        if (err) {
                phydev_warn(phydev, "Error %d requesting IRQ %d, falling back to polling\n",
                            err, phydev->irq);
                phydev->irq = PHY_POLL;
        }
}
EXPORT_SYMBOL(phy_request_interrupt);

/**
 * phy_stop - Bring down the PHY link, and stop checking the status
 * @phydev: target phy_device struct
 */
void phy_stop(struct phy_device *phydev)
{
        if (!phy_is_started(phydev)) {
                WARN(1, "called from state %s\n",
                     phy_state_to_str(phydev->state));
                return;
        }

        mutex_lock(&phydev->lock);

        if (phy_interrupt_is_valid(phydev))
                phy_disable_interrupts(phydev);

        phydev->state = PHY_HALTED;

        mutex_unlock(&phydev->lock);

        phy_state_machine(&phydev->state_queue.work);
        phy_stop_machine(phydev);

        /* Cannot call flush_scheduled_work() here as desired because
         * of rtnl_lock(), but PHY_HALTED shall guarantee irq handler
         * 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;

        mutex_lock(&phydev->lock);

        if (phydev->state != PHY_READY && phydev->state != PHY_HALTED) {
                WARN(1, "called from state %s\n",
                     phy_state_to_str(phydev->state));
                goto out;
        }

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

        /* make sure interrupts are enabled for the PHY */
        if (phy_interrupt_is_valid(phydev)) {
                err = phy_enable_interrupts(phydev);
                if (err < 0)
                        goto out;
        }

        phydev->state = PHY_UP;

        phy_start_machine(phydev);
out:
        mutex_unlock(&phydev->lock);
}
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;
        enum phy_state old_state;
        int err = 0;

        mutex_lock(&phydev->lock);

        old_state = phydev->state;

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

                break;
        case PHY_NOLINK:
        case PHY_RUNNING:
                err = phy_check_link_status(phydev);
                break;
        case PHY_FORCING:
                err = genphy_update_link(phydev);
                if (err)
                        break;

                if (phydev->link) {
                        phydev->state = PHY_RUNNING;
                        phy_link_up(phydev);
                } else {
                        if (0 == phydev->link_timeout--)
                                needs_aneg = true;
                        phy_link_down(phydev, false);
                }
                break;
        case PHY_HALTED:
                if (phydev->link) {
                        phydev->link = 0;
                        phy_link_down(phydev, true);
                        do_suspend = true;
                }
                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);

        if (old_state != phydev->state) {
                phydev_dbg(phydev, "PHY state change %s -> %s\n",
                           phy_state_to_str(old_state),
                           phy_state_to_str(phydev->state));
                if (phydev->drv && phydev->drv->link_change_notify)
                        phydev->drv->link_change_notify(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().
         *
         * In state PHY_HALTED the PHY gets suspended, so rescheduling the
         * state machine would be pointless and possibly error prone when
         * called from phy_disconnect() synchronously.
         */
        mutex_lock(&phydev->lock);
        if (phy_polling_mode(phydev) && phy_is_started(phydev))
                phy_queue_state_machine(phydev, PHY_STATE_TIME);
        mutex_unlock(&phydev->lock);
}

/**
 * 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 */
        phy_trigger_machine(phydev);
}
EXPORT_SYMBOL(phy_mac_interrupt);

static void mmd_eee_adv_to_linkmode(unsigned long *advertising, u16 eee_adv)
{
        linkmode_zero(advertising);

        if (eee_adv & MDIO_EEE_100TX)
                linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
                                 advertising);
        if (eee_adv & MDIO_EEE_1000T)
                linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
                                 advertising);
        if (eee_adv & MDIO_EEE_10GT)
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseT_Full_BIT,
                                 advertising);
        if (eee_adv & MDIO_EEE_1000KX)
                linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseKX_Full_BIT,
                                 advertising);
        if (eee_adv & MDIO_EEE_10GKX4)
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT,
                                 advertising);
        if (eee_adv & MDIO_EEE_10GKR)
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseKR_Full_BIT,
                                 advertising);
}

/**
 * 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.
         */
        if (phydev->duplex == DUPLEX_FULL) {
                __ETHTOOL_DECLARE_LINK_MODE_MASK(common);
                __ETHTOOL_DECLARE_LINK_MODE_MASK(lp);
                __ETHTOOL_DECLARE_LINK_MODE_MASK(adv);
                int eee_lp, eee_cap, eee_adv;
                int status;
                u32 cap;

                /* 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;

                mmd_eee_adv_to_linkmode(adv, eee_adv);
                mmd_eee_adv_to_linkmode(lp, eee_lp);
                linkmode_and(common, adv, lp);

                if (!phy_check_valid(phydev->speed, phydev->duplex, common))
                        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);
        data->eee_enabled = !!data->advertised;

        /* 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);

        data->eee_active = !!(data->advertised & data->lp_advertised);

        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 = 0, 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;

        if (data->eee_enabled) {
                adv = !data->advertised ? cap :
                      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;

        phy_ethtool_ksettings_get(phydev, cmd);

        return 0;
}
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);