// 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/netlink.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/ethtool_netlink.h>
#include <linux/phy.h>
#include <linux/phy_led_triggers.h>
#include <linux/sfp.h>
#include <linux/workqueue.h>
#include <linux/mdio.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
#include <linux/suspend.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/sock.h>

#include "phylib-internal.h"
#include "phy-caps.h"

#define PHY_STATE_TIME  HZ

#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(CABLETEST)
        PHY_STATE_STR(HALTED)
        PHY_STATE_STR(ERROR)
        }

        return NULL;
}

static void phy_process_state_change(struct phy_device *phydev,
                                     enum phy_state old_state)
{
        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);
        }
}

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

static void phy_link_down(struct phy_device *phydev)
{
        phydev->phy_link_change(phydev, false);
        phy_led_trigger_change_speed(phydev);
        WRITE_ONCE(phydev->link_down_events, phydev->link_down_events + 1);
}

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 %s- flow control %s\n",
                        phy_speed_to_str(phydev->speed),
                        phy_duplex_to_str(phydev->duplex),
                        phydev->downshifted_rate ? "(downshifted) " : "",
                        phy_pause_str(phydev));
        } else  {
                netdev_info(phydev->attached_dev, "Link is Down\n");
        }
}
EXPORT_SYMBOL(phy_print_status);

/**
 * phy_get_rate_matching - determine if rate matching is supported
 * @phydev: The phy device to return rate matching for
 * @iface: The interface mode to use
 *
 * This determines the type of rate matching (if any) that @phy supports
 * using @iface. @iface may be %PHY_INTERFACE_MODE_NA to determine if any
 * interface supports rate matching.
 *
 * Return: The type of rate matching @phy supports for @iface, or
 *         %RATE_MATCH_NONE.
 */
int phy_get_rate_matching(struct phy_device *phydev,
                          phy_interface_t iface)
{
        int ret = RATE_MATCH_NONE;

        if (phydev->drv->get_rate_matching) {
                mutex_lock(&phydev->lock);
                ret = phydev->drv->get_rate_matching(phydev, iface);
                mutex_unlock(&phydev->lock);
        }

        return ret;
}
EXPORT_SYMBOL_GPL(phy_get_rate_matching);

/**
 * 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_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_caps_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.
 */
bool phy_check_valid(int speed, int duplex, unsigned long *features)
{
        return phy_caps_valid(speed, duplex, features);
}
EXPORT_SYMBOL(phy_check_valid);

/**
 * 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 link_capabilities *c;

        c = phy_caps_lookup(phydev->speed, phydev->duplex, phydev->supported,
                            false);

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

void phy_ethtool_ksettings_get(struct phy_device *phydev,
                               struct ethtool_link_ksettings *cmd)
{
        mutex_lock(&phydev->lock);
        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;
        cmd->base.master_slave_cfg = phydev->master_slave_get;
        cmd->base.master_slave_state = phydev->master_slave_state;
        cmd->base.rate_matching = phydev->rate_matching;
        if (phydev->interface == PHY_INTERFACE_MODE_MOCA)
                cmd->base.port = PORT_BNC;
        else
                cmd->base.port = phydev->port;
        cmd->base.transceiver = phydev->is_internal ?
                                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;
        mutex_unlock(&phydev->lock);
}
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);
        struct kernel_hwtstamp_config kernel_cfg;
        struct netlink_ext_ack extack = {};
        u16 val = mii_data->val_in;
        bool change_autoneg = false;
        struct hwtstamp_config cfg;
        int prtad, devad;
        int ret;

        switch (cmd) {
        case SIOCGMIIPHY:
                mii_data->phy_id = phydev->mdio.addr;
                fallthrough;

        case SIOCGMIIREG:
                if (mdio_phy_id_is_c45(mii_data->phy_id)) {
                        prtad = mdio_phy_id_prtad(mii_data->phy_id);
                        devad = mdio_phy_id_devad(mii_data->phy_id);
                        ret = mdiobus_c45_read(phydev->mdio.bus, prtad, devad,
                                               mii_data->reg_num);

                } else {
                        ret = mdiobus_read(phydev->mdio.bus, mii_data->phy_id,
                                           mii_data->reg_num);
                }

                if (ret < 0)
                        return ret;

                mii_data->val_out = ret;

                return 0;

        case SIOCSMIIREG:
                if (mdio_phy_id_is_c45(mii_data->phy_id)) {
                        prtad = mdio_phy_id_prtad(mii_data->phy_id);
                        devad = mdio_phy_id_devad(mii_data->phy_id);
                } else {
                        prtad = mii_data->phy_id;
                        devad = mii_data->reg_num;
                }
                if (prtad == phydev->mdio.addr) {
                        switch (devad) {
                        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;
                        }
                }

                if (mdio_phy_id_is_c45(mii_data->phy_id))
                        mdiobus_c45_write(phydev->mdio.bus, prtad, devad,
                                          mii_data->reg_num, val);
                else
                        mdiobus_write(phydev->mdio.bus, prtad, devad, val);

                if (prtad == phydev->mdio.addr &&
                    devad == MII_BMCR &&
                    val & BMCR_RESET)
                        return phy_init_hw(phydev);

                if (change_autoneg)
                        return phy_start_aneg(phydev);

                return 0;

        case SIOCSHWTSTAMP:
                if (phydev->mii_ts && phydev->mii_ts->hwtstamp_set) {
                        if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
                                return -EFAULT;

                        hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
                        ret = phydev->mii_ts->hwtstamp_set(phydev->mii_ts,
                                                           &kernel_cfg,
                                                           &extack);
                        if (ret)
                                return ret;

                        hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
                        if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
                                return -EFAULT;

                        return 0;
                }
                fallthrough;

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

/**
 * phy_do_ioctl - generic ndo_eth_ioctl implementation
 * @dev: the net_device struct
 * @ifr: &struct ifreq for socket ioctl's
 * @cmd: ioctl cmd to execute
 */
int phy_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        if (!dev->phydev)
                return -ENODEV;

        return phy_mii_ioctl(dev->phydev, ifr, cmd);
}
EXPORT_SYMBOL(phy_do_ioctl);

/**
 * phy_do_ioctl_running - generic ndo_eth_ioctl implementation but test first
 *
 * @dev: the net_device struct
 * @ifr: &struct ifreq for socket ioctl's
 * @cmd: ioctl cmd to execute
 *
 * Same as phy_do_ioctl, but ensures that net_device is running before
 * handling the ioctl.
 */
int phy_do_ioctl_running(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        if (!netif_running(dev))
                return -ENODEV;

        return phy_do_ioctl(dev, ifr, cmd);
}
EXPORT_SYMBOL(phy_do_ioctl_running);

/**
 * __phy_hwtstamp_get - Get hardware timestamping configuration from PHY
 *
 * @phydev: the PHY device structure
 * @config: structure holding the timestamping configuration
 *
 * Query the PHY device for its current hardware timestamping configuration.
 */
int __phy_hwtstamp_get(struct phy_device *phydev,
                       struct kernel_hwtstamp_config *config)
{
        if (!phydev)
                return -ENODEV;

        if (phydev->mii_ts && phydev->mii_ts->hwtstamp_get)
                return phydev->mii_ts->hwtstamp_get(phydev->mii_ts, config);

        return -EOPNOTSUPP;
}

/**
 * __phy_hwtstamp_set - Modify PHY hardware timestamping configuration
 *
 * @phydev: the PHY device structure
 * @config: structure holding the timestamping configuration
 * @extack: netlink extended ack structure, for error reporting
 */
int __phy_hwtstamp_set(struct phy_device *phydev,
                       struct kernel_hwtstamp_config *config,
                       struct netlink_ext_ack *extack)
{
        if (!phydev)
                return -ENODEV;

        if (phydev->mii_ts && phydev->mii_ts->hwtstamp_set)
                return phydev->mii_ts->hwtstamp_set(phydev->mii_ts, config,
                                                    extack);

        return -EOPNOTSUPP;
}

/**
 * phy_queue_state_machine - Trigger the state machine to run soon
 *
 * @phydev: the phy_device struct
 * @jiffies: Run the state machine after these jiffies
 */
static void phy_queue_state_machine(struct phy_device *phydev,
                                    unsigned long jiffies)
{
        mod_delayed_work(system_power_efficient_wq, &phydev->state_queue,
                         jiffies);
}

/**
 * phy_trigger_machine - Trigger the state machine to run now
 *
 * @phydev: the phy_device struct
 */
void phy_trigger_machine(struct phy_device *phydev)
{
        phy_queue_state_machine(phydev, 0);
}
EXPORT_SYMBOL(phy_trigger_machine);

static void phy_abort_cable_test(struct phy_device *phydev)
{
        int err;

        ethnl_cable_test_finished(phydev);

        err = phy_init_hw(phydev);
        if (err)
                phydev_err(phydev, "Error while aborting cable test");
}

/**
 * phy_ethtool_get_strings - Get the statistic counter names
 *
 * @phydev: the phy_device struct
 * @data: Where to put the strings
 */
int phy_ethtool_get_strings(struct phy_device *phydev, u8 *data)
{
        if (!phydev->drv)
                return -EIO;

        mutex_lock(&phydev->lock);
        phydev->drv->get_strings(phydev, data);
        mutex_unlock(&phydev->lock);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_get_strings);

/**
 * phy_ethtool_get_sset_count - Get the number of statistic counters
 *
 * @phydev: the phy_device struct
 */
int phy_ethtool_get_sset_count(struct phy_device *phydev)
{
        int ret;

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

        if (phydev->drv->get_sset_count &&
            phydev->drv->get_strings &&
            phydev->drv->get_stats) {
                mutex_lock(&phydev->lock);
                ret = phydev->drv->get_sset_count(phydev);
                mutex_unlock(&phydev->lock);

                return ret;
        }

        return -EOPNOTSUPP;
}
EXPORT_SYMBOL(phy_ethtool_get_sset_count);

/**
 * phy_ethtool_get_stats - Get the statistic counters
 *
 * @phydev: the phy_device struct
 * @stats: What counters to get
 * @data: Where to store the counters
 */
int phy_ethtool_get_stats(struct phy_device *phydev,
                          struct ethtool_stats *stats, u64 *data)
{
        if (!phydev->drv)
                return -EIO;

        mutex_lock(&phydev->lock);
        phydev->drv->get_stats(phydev, stats, data);
        mutex_unlock(&phydev->lock);

        return 0;
}
EXPORT_SYMBOL(phy_ethtool_get_stats);

/**
 * __phy_ethtool_get_phy_stats - Retrieve standardized PHY statistics
 * @phydev: Pointer to the PHY device
 * @phy_stats: Pointer to ethtool_eth_phy_stats structure
 * @phydev_stats: Pointer to ethtool_phy_stats structure
 *
 * Fetches PHY statistics using a kernel-defined interface for consistent
 * diagnostics. Unlike phy_ethtool_get_stats(), which allows custom stats,
 * this function enforces a standardized format for better interoperability.
 */
void __phy_ethtool_get_phy_stats(struct phy_device *phydev,
                                 struct ethtool_eth_phy_stats *phy_stats,
                                 struct ethtool_phy_stats *phydev_stats)
{
        if (!phydev->drv || !phydev->drv->get_phy_stats)
                return;

        mutex_lock(&phydev->lock);
        phydev->drv->get_phy_stats(phydev, phy_stats, phydev_stats);
        mutex_unlock(&phydev->lock);
}

/**
 * __phy_ethtool_get_link_ext_stats - Retrieve extended link statistics for a PHY
 * @phydev: Pointer to the PHY device
 * @link_stats: Pointer to the structure to store extended link statistics
 *
 * Populates the ethtool_link_ext_stats structure with link down event counts
 * and additional driver-specific link statistics, if available.
 */
void __phy_ethtool_get_link_ext_stats(struct phy_device *phydev,
                                      struct ethtool_link_ext_stats *link_stats)
{
        link_stats->link_down_events = READ_ONCE(phydev->link_down_events);

        if (!phydev->drv || !phydev->drv->get_link_stats)
                return;

        mutex_lock(&phydev->lock);
        phydev->drv->get_link_stats(phydev, link_stats);
        mutex_unlock(&phydev->lock);
}

/**
 * phy_ethtool_get_plca_cfg - Get PLCA RS configuration
 * @phydev: the phy_device struct
 * @plca_cfg: where to store the retrieved configuration
 *
 * Retrieve the PLCA configuration from the PHY. Return 0 on success or a
 * negative value if an error occurred.
 */
int phy_ethtool_get_plca_cfg(struct phy_device *phydev,
                             struct phy_plca_cfg *plca_cfg)
{
        int ret;

        if (!phydev->drv) {
                ret = -EIO;
                goto out;
        }

        if (!phydev->drv->get_plca_cfg) {
                ret = -EOPNOTSUPP;
                goto out;
        }

        mutex_lock(&phydev->lock);
        ret = phydev->drv->get_plca_cfg(phydev, plca_cfg);

        mutex_unlock(&phydev->lock);
out:
        return ret;
}

/**
 * plca_check_valid - Check PLCA configuration before enabling
 * @phydev: the phy_device struct
 * @plca_cfg: current PLCA configuration
 * @extack: extack for reporting useful error messages
 *
 * Checks whether the PLCA and PHY configuration are consistent and it is safe
 * to enable PLCA. Returns 0 on success or a negative value if the PLCA or PHY
 * configuration is not consistent.
 */
static int plca_check_valid(struct phy_device *phydev,
                            const struct phy_plca_cfg *plca_cfg,
                            struct netlink_ext_ack *extack)
{
        int ret = 0;

        if (!linkmode_test_bit(ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT,
                               phydev->advertising)) {
                ret = -EOPNOTSUPP;
                NL_SET_ERR_MSG(extack,
                               "Point to Multi-Point mode is not enabled");
        } else if (plca_cfg->node_id >= 255) {
                NL_SET_ERR_MSG(extack, "PLCA node ID is not set");
                ret = -EINVAL;
        }

        return ret;
}

/**
 * phy_ethtool_set_plca_cfg - Set PLCA RS configuration
 * @phydev: the phy_device struct
 * @plca_cfg: new PLCA configuration to apply
 * @extack: extack for reporting useful error messages
 *
 * Sets the PLCA configuration in the PHY. Return 0 on success or a
 * negative value if an error occurred.
 */
int phy_ethtool_set_plca_cfg(struct phy_device *phydev,
                             const struct phy_plca_cfg *plca_cfg,
                             struct netlink_ext_ack *extack)
{
        struct phy_plca_cfg *curr_plca_cfg;
        int ret;

        if (!phydev->drv) {
                ret = -EIO;
                goto out;
        }

        if (!phydev->drv->set_plca_cfg ||
            !phydev->drv->get_plca_cfg) {
                ret = -EOPNOTSUPP;
                goto out;
        }

        curr_plca_cfg = kmalloc_obj(*curr_plca_cfg);
        if (!curr_plca_cfg) {
                ret = -ENOMEM;
                goto out;
        }

        mutex_lock(&phydev->lock);

        ret = phydev->drv->get_plca_cfg(phydev, curr_plca_cfg);
        if (ret)
                goto out_drv;

        if (curr_plca_cfg->enabled < 0 && plca_cfg->enabled >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'enable' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        if (curr_plca_cfg->node_id < 0 && plca_cfg->node_id >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'local node ID' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        if (curr_plca_cfg->node_cnt < 0 && plca_cfg->node_cnt >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'node count' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        if (curr_plca_cfg->to_tmr < 0 && plca_cfg->to_tmr >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'TO timer' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        if (curr_plca_cfg->burst_cnt < 0 && plca_cfg->burst_cnt >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'burst count' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        if (curr_plca_cfg->burst_tmr < 0 && plca_cfg->burst_tmr >= 0) {
                NL_SET_ERR_MSG(extack,
                               "PHY does not support changing the PLCA 'burst timer' attribute");
                ret = -EINVAL;
                goto out_drv;
        }

        // if enabling PLCA, perform a few sanity checks
        if (plca_cfg->enabled > 0) {
                // allow setting node_id concurrently with enabled
                if (plca_cfg->node_id >= 0)
                        curr_plca_cfg->node_id = plca_cfg->node_id;

                ret = plca_check_valid(phydev, curr_plca_cfg, extack);
                if (ret)
                        goto out_drv;
        }

        ret = phydev->drv->set_plca_cfg(phydev, plca_cfg);

out_drv:
        kfree(curr_plca_cfg);
        mutex_unlock(&phydev->lock);
out:
        return ret;
}

/**
 * phy_ethtool_get_plca_status - Get PLCA RS status information
 * @phydev: the phy_device struct
 * @plca_st: where to store the retrieved status information
 *
 * Retrieve the PLCA status information from the PHY. Return 0 on success or a
 * negative value if an error occurred.
 */
int phy_ethtool_get_plca_status(struct phy_device *phydev,
                                struct phy_plca_status *plca_st)
{
        int ret;

        if (!phydev->drv) {
                ret = -EIO;
                goto out;
        }

        if (!phydev->drv->get_plca_status) {
                ret = -EOPNOTSUPP;
                goto out;
        }

        mutex_lock(&phydev->lock);
        ret = phydev->drv->get_plca_status(phydev, plca_st);

        mutex_unlock(&phydev->lock);
out:
        return ret;
}

/**
 * phy_start_cable_test - Start a cable test
 *
 * @phydev: the phy_device struct
 * @extack: extack for reporting useful error messages
 */
int phy_start_cable_test(struct phy_device *phydev,
                         struct netlink_ext_ack *extack)
{
        struct net_device *dev = phydev->attached_dev;
        int err = -ENOMEM;

        if (!(phydev->drv &&
              phydev->drv->cable_test_start &&
              phydev->drv->cable_test_get_status)) {
                NL_SET_ERR_MSG(extack,
                               "PHY driver does not support cable testing");
                return -EOPNOTSUPP;
        }

        mutex_lock(&phydev->lock);
        if (phydev->state == PHY_CABLETEST) {
                NL_SET_ERR_MSG(extack,
                               "PHY already performing a test");
                err = -EBUSY;
                goto out;
        }

        if (phydev->state < PHY_UP ||
            phydev->state > PHY_CABLETEST) {
                NL_SET_ERR_MSG(extack,
                               "PHY not configured. Try setting interface up");
                err = -EBUSY;
                goto out;
        }

        err = ethnl_cable_test_alloc(phydev, ETHTOOL_MSG_CABLE_TEST_NTF);
        if (err)
                goto out;

        /* Mark the carrier down until the test is complete */
        phy_link_down(phydev);

        netif_testing_on(dev);
        err = phydev->drv->cable_test_start(phydev);
        if (err) {
                netif_testing_off(dev);
                phy_link_up(phydev);
                goto out_free;
        }

        phydev->state = PHY_CABLETEST;

        if (phy_polling_mode(phydev))
                phy_trigger_machine(phydev);

        mutex_unlock(&phydev->lock);

        return 0;

out_free:
        ethnl_cable_test_free(phydev);
out:
        mutex_unlock(&phydev->lock);

        return err;
}
EXPORT_SYMBOL(phy_start_cable_test);

/**
 * phy_start_cable_test_tdr - Start a raw TDR cable test
 *
 * @phydev: the phy_device struct
 * @extack: extack for reporting useful error messages
 * @config: Configuration of the test to run
 */
int phy_start_cable_test_tdr(struct phy_device *phydev,
                             struct netlink_ext_ack *extack,
                             const struct phy_tdr_config *config)
{
        struct net_device *dev = phydev->attached_dev;
        int err = -ENOMEM;

        if (!(phydev->drv &&
              phydev->drv->cable_test_tdr_start &&
              phydev->drv->cable_test_get_status)) {
                NL_SET_ERR_MSG(extack,
                               "PHY driver does not support cable test TDR");
                return -EOPNOTSUPP;
        }

        mutex_lock(&phydev->lock);
        if (phydev->state == PHY_CABLETEST) {
                NL_SET_ERR_MSG(extack,
                               "PHY already performing a test");
                err = -EBUSY;
                goto out;
        }

        if (phydev->state < PHY_UP ||
            phydev->state > PHY_CABLETEST) {
                NL_SET_ERR_MSG(extack,
                               "PHY not configured. Try setting interface up");
                err = -EBUSY;
                goto out;
        }

        err = ethnl_cable_test_alloc(phydev, ETHTOOL_MSG_CABLE_TEST_TDR_NTF);
        if (err)
                goto out;

        /* Mark the carrier down until the test is complete */
        phy_link_down(phydev);

        netif_testing_on(dev);
        err = phydev->drv->cable_test_tdr_start(phydev, config);
        if (err) {
                netif_testing_off(dev);
                phy_link_up(phydev);
                goto out_free;
        }

        phydev->state = PHY_CABLETEST;

        if (phy_polling_mode(phydev))
                phy_trigger_machine(phydev);

        mutex_unlock(&phydev->lock);

        return 0;

out_free:
        ethnl_cable_test_free(phydev);
out:
        mutex_unlock(&phydev->lock);

        return err;
}
EXPORT_SYMBOL(phy_start_cable_test_tdr);

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);
}
EXPORT_SYMBOL(phy_config_aneg);

/**
 * 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;

        lockdep_assert_held(&phydev->lock);

        /* Keep previous state if loopback is enabled because some PHYs
         * report that Link is Down when loopback is enabled.
         */
        if (phydev->loopback_enabled)
                return 0;

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

        if (phydev->link && phydev->state != PHY_RUNNING) {
                phy_check_downshift(phydev);
                phydev->state = PHY_RUNNING;
                err = genphy_c45_eee_is_active(phydev, NULL);
                phydev->eee_active = err > 0;
                phydev->enable_tx_lpi = phydev->eee_cfg.tx_lpi_enabled &&
                                        phydev->eee_active;

                phy_link_up(phydev);
        } else if (!phydev->link && phydev->state != PHY_NOLINK) {
                phydev->state = PHY_NOLINK;
                phydev->eee_active = false;
                phydev->enable_tx_lpi = false;
                phy_link_down(phydev);
        }

        return 0;
}

/**
 * phy_inband_caps - query which in-band signalling modes are supported
 * @phydev: a pointer to a &struct phy_device
 * @interface: the interface mode for the PHY
 *
 * Returns zero if it is unknown what in-band signalling is supported by the
 * PHY (e.g. because the PHY driver doesn't implement the method.) Otherwise,
 * returns a bit mask of the LINK_INBAND_* values from
 * &enum link_inband_signalling to describe which inband modes are supported
 * by the PHY for this interface mode.
 */
unsigned int phy_inband_caps(struct phy_device *phydev,
                             phy_interface_t interface)
{
        if (phydev->drv && phydev->drv->inband_caps)
                return phydev->drv->inband_caps(phydev, interface);

        return 0;
}
EXPORT_SYMBOL_GPL(phy_inband_caps);

/**
 * phy_config_inband - configure the desired PHY in-band mode
 * @phydev: the phy_device struct
 * @modes: in-band modes to configure
 *
 * Description: disables, enables or enables-with-bypass in-band signalling
 *   between the PHY and host system.
 *
 * Returns: zero on success, or negative errno value.
 */
int phy_config_inband(struct phy_device *phydev, unsigned int modes)
{
        lockdep_assert_held(&phydev->lock);

        if (!!(modes & LINK_INBAND_DISABLE) +
            !!(modes & LINK_INBAND_ENABLE) +
            !!(modes & LINK_INBAND_BYPASS) != 1)
                return -EINVAL;

        if (!phydev->drv)
                return -EIO;
        else if (!phydev->drv->config_inband)
                return -EOPNOTSUPP;

        return phydev->drv->config_inband(phydev, modes);
}
EXPORT_SYMBOL(phy_config_inband);

/**
 * _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;

        lockdep_assert_held(&phydev->lock);

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

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

        err = phy_config_aneg(phydev);
        if (err < 0)
                return err;

        if (phy_is_started(phydev))
                err = phy_check_link_status(phydev);

        return err;
}
EXPORT_SYMBOL(_phy_start_aneg);

/**
 * 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);
        err = _phy_start_aneg(phydev);
        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;
}

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) ||
             !linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                phydev->supported)))
                return -EINVAL;

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

        mutex_lock(&phydev->lock);
        phydev->autoneg = autoneg;

        if (autoneg == AUTONEG_DISABLE) {
                phydev->speed = speed;
                phydev->duplex = duplex;
        }

        linkmode_copy(phydev->advertising, advertising);

        linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                         phydev->advertising, autoneg == AUTONEG_ENABLE);

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

        /* Restart the PHY */
        if (phy_is_started(phydev)) {
                phydev->state = PHY_UP;
                phy_trigger_machine(phydev);
        } else {
                _phy_start_aneg(phydev);
        }

        mutex_unlock(&phydev->lock);
        return 0;
}
EXPORT_SYMBOL(phy_ethtool_ksettings_set);

/**
 * 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_tmp);
        int ret = 0;

        mutex_lock(&phydev->lock);

        if (phydev->autoneg != AUTONEG_ENABLE)
                goto out;

        linkmode_copy(adv_tmp, phydev->advertising);

        ret = phy_speed_down_core(phydev);
        if (ret)
                goto out;

        linkmode_copy(phydev->adv_old, adv_tmp);

        if (linkmode_equal(phydev->advertising, adv_tmp)) {
                ret = 0;
                goto out;
        }

        ret = phy_config_aneg(phydev);
        if (ret)
                goto out;

        ret = sync ? phy_poll_aneg_done(phydev) : 0;
out:
        mutex_unlock(&phydev->lock);

        return ret;
}
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(adv_tmp);
        int ret = 0;

        mutex_lock(&phydev->lock);

        if (phydev->autoneg != AUTONEG_ENABLE)
                goto out;

        if (linkmode_empty(phydev->adv_old))
                goto out;

        linkmode_copy(adv_tmp, phydev->advertising);
        linkmode_copy(phydev->advertising, phydev->adv_old);
        linkmode_zero(phydev->adv_old);

        if (linkmode_equal(phydev->advertising, adv_tmp))
                goto out;

        ret = phy_config_aneg(phydev);
out:
        mutex_unlock(&phydev->lock);

        return ret;
}
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);
}

static void phy_process_error(struct phy_device *phydev)
{
        /* phydev->lock must be held for the state change to be safe */
        if (!mutex_is_locked(&phydev->lock))
                phydev_err(phydev, "PHY-device data unsafe context\n");

        phydev->state = PHY_ERROR;

        phy_trigger_machine(phydev);
}

static void phy_error_precise(struct phy_device *phydev,
                              const void *func, int err)
{
        WARN(1, "%pS: returned: %d\n", func, err);
        phy_process_error(phydev);
}

/**
 * phy_error - enter ERROR state for this PHY device
 * @phydev: target phy_device struct
 *
 * Moves the PHY to the ERROR state in response to a read
 * or write error, and tells the controller the link is down.
 * Must be called with phydev->lock held.
 */
void phy_error(struct phy_device *phydev)
{
        WARN_ON(1);
        phy_process_error(phydev);
}
EXPORT_SYMBOL(phy_error);

/**
 * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
 * @phydev: target phy_device struct
 */
int phy_disable_interrupts(struct phy_device *phydev)
{
        /* Disable PHY interrupts */
        return phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
}

/**
 * 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;
        irqreturn_t ret;

        /* Wakeup interrupts may occur during a system sleep transition.
         * Postpone handling until the PHY has resumed.
         */
        if (IS_ENABLED(CONFIG_PM_SLEEP) && phydev->irq_suspended) {
                struct net_device *netdev = phydev->attached_dev;

                if (netdev) {
                        struct device *parent = netdev->dev.parent;

                        if (netdev->ethtool->wol_enabled)
                                pm_system_wakeup();
                        else if (device_may_wakeup(&netdev->dev))
                                pm_wakeup_dev_event(&netdev->dev, 0, true);
                        else if (parent && device_may_wakeup(parent))
                                pm_wakeup_dev_event(parent, 0, true);
                }

                phydev->irq_rerun = 1;
                disable_irq_nosync(irq);
                return IRQ_HANDLED;
        }

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

        return ret;
}

/**
 * phy_enable_interrupts - Enable the interrupts from the PHY side
 * @phydev: target phy_device struct
 */
static int phy_enable_interrupts(struct phy_device *phydev)
{
        return phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
}

/**
 * phy_update_stats - Update PHY device statistics if supported.
 * @phydev: Pointer to the PHY device structure.
 *
 * If the PHY driver provides an update_stats callback, this function
 * invokes it to update the PHY statistics. If not, it returns 0.
 *
 * Return: 0 on success, or a negative error code if the callback fails.
 */
static int phy_update_stats(struct phy_device *phydev)
{
        if (!phydev->drv->update_stats)
                return 0;

        return phydev->drv->update_stats(phydev);
}

/**
 * phy_request_interrupt - request and enable interrupt for a PHY device
 * @phydev: target phy_device struct
 *
 * Description: Request and enable 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;
        } else {
                if (phy_enable_interrupts(phydev)) {
                        phydev_warn(phydev, "Can't enable interrupt, falling back to polling\n");
                        phy_free_interrupt(phydev);
                        phydev->irq = PHY_POLL;
                }
        }
}
EXPORT_SYMBOL(phy_request_interrupt);

/**
 * phy_free_interrupt - disable and free interrupt for a PHY device
 * @phydev: target phy_device struct
 *
 * Description: Disable and free the interrupt for the given PHY.
 *   This should only be called with a valid IRQ number.
 */
void phy_free_interrupt(struct phy_device *phydev)
{
        phy_disable_interrupts(phydev);
        free_irq(phydev->irq, phydev);
}
EXPORT_SYMBOL(phy_free_interrupt);

/**
 * phy_get_next_update_time - Determine the next PHY update time
 * @phydev: Pointer to the phy_device structure
 *
 * This function queries the PHY driver to get the time for the next polling
 * event. If the driver does not implement the callback, a default value is
 * used.
 *
 * Return: The time for the next polling event in jiffies
 */
static unsigned int phy_get_next_update_time(struct phy_device *phydev)
{
        if (phydev->drv && phydev->drv->get_next_update_time)
                return phydev->drv->get_next_update_time(phydev);

        return PHY_STATE_TIME;
}

enum phy_state_work {
        PHY_STATE_WORK_NONE,
        PHY_STATE_WORK_ANEG,
        PHY_STATE_WORK_SUSPEND,
};

static enum phy_state_work _phy_state_machine(struct phy_device *phydev)
{
        enum phy_state_work state_work = PHY_STATE_WORK_NONE;
        struct net_device *dev = phydev->attached_dev;
        enum phy_state old_state = phydev->state;
        const void *func = NULL;
        bool finished = false;
        int err = 0;

        switch (phydev->state) {
        case PHY_DOWN:
        case PHY_READY:
                break;
        case PHY_UP:
                state_work = PHY_STATE_WORK_ANEG;
                break;
        case PHY_NOLINK:
        case PHY_RUNNING:
                err = phy_check_link_status(phydev);
                func = &phy_check_link_status;

                if (!err)
                        err = phy_update_stats(phydev);
                break;
        case PHY_CABLETEST:
                err = phydev->drv->cable_test_get_status(phydev, &finished);
                if (err) {
                        phy_abort_cable_test(phydev);
                        netif_testing_off(dev);
                        state_work = PHY_STATE_WORK_ANEG;
                        phydev->state = PHY_UP;
                        break;
                }

                if (finished) {
                        ethnl_cable_test_finished(phydev);
                        netif_testing_off(dev);
                        state_work = PHY_STATE_WORK_ANEG;
                        phydev->state = PHY_UP;
                }
                break;
        case PHY_HALTED:
                if (phydev->link) {
                        if (phydev->autoneg == AUTONEG_ENABLE) {
                                phydev->speed = SPEED_UNKNOWN;
                                phydev->duplex = DUPLEX_UNKNOWN;
                        }
                        if (phydev->master_slave_state !=
                                                MASTER_SLAVE_STATE_UNSUPPORTED)
                                phydev->master_slave_state =
                                                MASTER_SLAVE_STATE_UNKNOWN;
                        phydev->mdix = ETH_TP_MDI_INVALID;
                        linkmode_zero(phydev->lp_advertising);
                }
                fallthrough;
        case PHY_ERROR:
                if (phydev->link) {
                        phydev->link = 0;
                        phydev->eee_active = false;
                        phydev->enable_tx_lpi = false;
                        phy_link_down(phydev);
                }
                state_work = PHY_STATE_WORK_SUSPEND;
                break;
        }

        if (state_work == PHY_STATE_WORK_ANEG) {
                err = _phy_start_aneg(phydev);
                func = &_phy_start_aneg;
        }

        if (err == -ENODEV)
                return state_work;

        if (err < 0)
                phy_error_precise(phydev, func, err);

        phy_process_state_change(phydev, old_state);

        /* Only re-schedule a PHY state machine change if we are polling the
         * PHY, if PHY_MAC_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.
         */
        if (phy_polling_mode(phydev) && phy_is_started(phydev))
                phy_queue_state_machine(phydev,
                                        phy_get_next_update_time(phydev));

        return state_work;
}

/* unlocked part of the PHY state machine */
static void _phy_state_machine_post_work(struct phy_device *phydev,
                                         enum phy_state_work state_work)
{
        if (state_work == PHY_STATE_WORK_SUSPEND)
                phy_suspend(phydev);
}

/**
 * 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);
        enum phy_state_work state_work;

        mutex_lock(&phydev->lock);
        state_work = _phy_state_machine(phydev);
        mutex_unlock(&phydev->lock);

        _phy_state_machine_post_work(phydev, state_work);
}

/**
 * phy_stop - Bring down the PHY link, and stop checking the status
 * @phydev: target phy_device struct
 */
void phy_stop(struct phy_device *phydev)
{
        struct net_device *dev = phydev->attached_dev;
        enum phy_state_work state_work;
        enum phy_state old_state;

        if (!phy_is_started(phydev) && phydev->state != PHY_DOWN &&
            phydev->state != PHY_ERROR) {
                WARN(1, "called from state %s\n",
                     phy_state_to_str(phydev->state));
                return;
        }

        mutex_lock(&phydev->lock);
        old_state = phydev->state;

        if (phydev->state == PHY_CABLETEST) {
                phy_abort_cable_test(phydev);
                netif_testing_off(dev);
        }

        if (phydev->sfp_bus)
                sfp_upstream_stop(phydev->sfp_bus);

        phydev->state = PHY_HALTED;
        phy_process_state_change(phydev, old_state);

        state_work = _phy_state_machine(phydev);
        mutex_unlock(&phydev->lock);

        _phy_state_machine_post_work(phydev, state_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)
{
        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 (phydev->sfp_bus)
                sfp_upstream_start(phydev->sfp_bus);

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

        phydev->state = PHY_UP;

        phy_start_machine(phydev);
out:
        mutex_unlock(&phydev->lock);
}
EXPORT_SYMBOL(phy_start);

/**
 * 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);

/**
 * phy_loopback - Configure loopback mode of PHY
 * @phydev: target phy_device struct
 * @enable: enable or disable loopback mode
 * @speed: enable loopback mode with speed
 *
 * Configure loopback mode of PHY and signal link down and link up if speed is
 * changing.
 *
 * Return: 0 on success, negative error code on failure.
 */
int phy_loopback(struct phy_device *phydev, bool enable, int speed)
{
        bool link_up = false;
        int ret = 0;

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

        mutex_lock(&phydev->lock);

        if (enable && phydev->loopback_enabled) {
                ret = -EBUSY;
                goto out;
        }

        if (!enable && !phydev->loopback_enabled) {
                ret = -EINVAL;
                goto out;
        }

        if (enable) {
                /*
                 * Link up is signaled with a defined speed. If speed changes,
                 * then first link down and after that link up needs to be
                 * signaled.
                 */
                if (phydev->link && phydev->state == PHY_RUNNING) {
                        /* link is up and signaled */
                        if (speed && phydev->speed != speed) {
                                /* signal link down and up for new speed */
                                phydev->link = false;
                                phydev->state = PHY_NOLINK;
                                phy_link_down(phydev);

                                link_up = true;
                        }
                } else {
                        /* link is not signaled */
                        if (speed) {
                                /* signal link up for new speed */
                                link_up = true;
                        }
                }
        }

        if (phydev->drv->set_loopback)
                ret = phydev->drv->set_loopback(phydev, enable, speed);
        else
                ret = genphy_loopback(phydev, enable, speed);

        if (ret) {
                if (enable) {
                        /* try to restore link if enabling loopback fails */
                        if (phydev->drv->set_loopback)
                                phydev->drv->set_loopback(phydev, false, 0);
                        else
                                genphy_loopback(phydev, false, 0);
                }

                goto out;
        }

        if (link_up) {
                phydev->link = true;
                phydev->state = PHY_RUNNING;
                phy_link_up(phydev);
        }

        phydev->loopback_enabled = enable;

out:
        mutex_unlock(&phydev->lock);
        return ret;
}
EXPORT_SYMBOL(phy_loopback);

/**
 * phy_eee_tx_clock_stop_capable() - indicate whether the MAC can stop tx clock
 * @phydev: target phy_device struct
 *
 * Indicate whether the MAC can disable the transmit xMII clock while in LPI
 * state. Returns 1 if the MAC may stop the transmit clock, 0 if the MAC must
 * not stop the transmit clock, or negative error.
 */
int phy_eee_tx_clock_stop_capable(struct phy_device *phydev)
{
        int stat1;

        stat1 = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_STAT1);
        if (stat1 < 0)
                return stat1;

        return !!(stat1 & MDIO_PCS_STAT1_CLKSTOP_CAP);
}
EXPORT_SYMBOL_GPL(phy_eee_tx_clock_stop_capable);

/**
 * phy_eee_rx_clock_stop() - configure PHY receive clock in LPI
 * @phydev: target phy_device struct
 * @clk_stop_enable: flag to indicate whether the clock can be stopped
 *
 * Configure whether the PHY can disable its receive clock during LPI mode,
 * See IEEE 802.3 sections 22.2.2.2, 35.2.2.10, and 45.2.3.1.4.
 *
 * Returns: 0 or negative error.
 */
int phy_eee_rx_clock_stop(struct phy_device *phydev, bool clk_stop_enable)
{
        /* Configure the PHY to stop receiving xMII
         * clock while it is signaling LPI.
         */
        return phy_modify_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
                              MDIO_PCS_CTRL1_CLKSTOP_EN,
                              clk_stop_enable ? MDIO_PCS_CTRL1_CLKSTOP_EN : 0);
}
EXPORT_SYMBOL_GPL(phy_eee_rx_clock_stop);

/**
 * 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;

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

        ret = genphy_c45_eee_is_active(phydev, NULL);
        if (ret < 0)
                return ret;
        if (!ret)
                return -EPROTONOSUPPORT;

        if (clk_stop_enable)
                ret = phy_eee_rx_clock_stop(phydev, true);

        return ret < 0 ? ret : 0;
}
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)
{
        int ret;

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

        mutex_lock(&phydev->lock);
        ret = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_WK_ERR);
        mutex_unlock(&phydev->lock);

        return ret;
}
EXPORT_SYMBOL(phy_get_eee_err);

/**
 * phy_ethtool_get_eee - get EEE supported and status
 * @phydev: target phy_device struct
 * @data: ethtool_keee data
 *
 * Description: get the current EEE settings, filling in all members of
 * @data.
 */
int phy_ethtool_get_eee(struct phy_device *phydev, struct ethtool_keee *data)
{
        int ret;

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

        mutex_lock(&phydev->lock);
        ret = genphy_c45_ethtool_get_eee(phydev, data);
        eeecfg_to_eee(data, &phydev->eee_cfg);
        mutex_unlock(&phydev->lock);

        return ret;
}
EXPORT_SYMBOL(phy_ethtool_get_eee);

/**
 * phy_ethtool_set_eee_noneg - Adjusts MAC LPI configuration without PHY
 *                             renegotiation
 * @phydev: pointer to the target PHY device structure
 * @old_cfg: pointer to the eee_config structure containing the old EEE settings
 *
 * This function updates the Energy Efficient Ethernet (EEE) configuration
 * for cases where only the MAC's Low Power Idle (LPI) configuration changes,
 * without triggering PHY renegotiation. It ensures that the MAC is properly
 * informed of the new LPI settings by cycling the link down and up, which
 * is necessary for the MAC to adopt the new configuration. This adjustment
 * is done only if there is a change in the tx_lpi_enabled or tx_lpi_timer
 * configuration.
 */
static void phy_ethtool_set_eee_noneg(struct phy_device *phydev,
                                      const struct eee_config *old_cfg)
{
        bool enable_tx_lpi;

        if (!phydev->link)
                return;

        enable_tx_lpi = phydev->eee_cfg.tx_lpi_enabled && phydev->eee_active;

        if (phydev->enable_tx_lpi != enable_tx_lpi ||
            phydev->eee_cfg.tx_lpi_timer != old_cfg->tx_lpi_timer) {
                phydev->enable_tx_lpi = false;
                phydev->link = false;
                phy_link_down(phydev);
                phydev->enable_tx_lpi = enable_tx_lpi;
                phydev->link = true;
                phy_link_up(phydev);
        }
}

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

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

        mutex_lock(&phydev->lock);

        old_cfg = phydev->eee_cfg;
        eee_to_eeecfg(&phydev->eee_cfg, data);

        ret = genphy_c45_ethtool_set_eee(phydev, data);
        if (ret == 0)
                phy_ethtool_set_eee_noneg(phydev, &old_cfg);
        else if (ret < 0)
                phydev->eee_cfg = old_cfg;

        mutex_unlock(&phydev->lock);

        return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL(phy_ethtool_set_eee);

/**
 * phy_ethtool_set_wol - Configure Wake On LAN
 *
 * @phydev: target phy_device struct
 * @wol: Configuration requested
 */
int phy_ethtool_set_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol)
{
        int ret;

        if (phydev->drv && phydev->drv->set_wol) {
                mutex_lock(&phydev->lock);
                ret = phydev->drv->set_wol(phydev, wol);
                mutex_unlock(&phydev->lock);

                return ret;
        }

        return -EOPNOTSUPP;
}
EXPORT_SYMBOL(phy_ethtool_set_wol);

/**
 * phy_ethtool_get_wol - Get the current Wake On LAN configuration
 *
 * @phydev: target phy_device struct
 * @wol: Store the current configuration here
 */
void phy_ethtool_get_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol)
{
        if (phydev->drv && phydev->drv->get_wol) {
                mutex_lock(&phydev->lock);
                phydev->drv->get_wol(phydev, wol);
                mutex_unlock(&phydev->lock);
        }
}
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);

/**
 * phy_ethtool_nway_reset - Restart auto negotiation
 * @ndev: Network device to restart autoneg for
 */
int phy_ethtool_nway_reset(struct net_device *ndev)
{
        struct phy_device *phydev = ndev->phydev;
        int ret;

        if (!phydev)
                return -ENODEV;

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

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

        return ret;
}
EXPORT_SYMBOL(phy_ethtool_nway_reset);