// SPDX-License-Identifier: GPL-2.0
/*
 * phylink models the MAC to optional PHY connection, supporting
 * technologies such as SFP cages where the PHY is hot-pluggable.
 *
 * Copyright (C) 2015 Russell King
 */
#include <linux/ethtool.h>
#include <linux/export.h>
#include <linux/gpio/consumer.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/phylink.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/workqueue.h>

#include "sfp.h"
#include "swphy.h"

#define SUPPORTED_INTERFACES \
        (SUPPORTED_TP | SUPPORTED_MII | SUPPORTED_FIBRE | \
         SUPPORTED_BNC | SUPPORTED_AUI | SUPPORTED_Backplane)
#define ADVERTISED_INTERFACES \
        (ADVERTISED_TP | ADVERTISED_MII | ADVERTISED_FIBRE | \
         ADVERTISED_BNC | ADVERTISED_AUI | ADVERTISED_Backplane)

enum {
        PHYLINK_DISABLE_STOPPED,
        PHYLINK_DISABLE_LINK,
};

/**
 * struct phylink - internal data type for phylink
 */
struct phylink {
        /* private: */
        struct net_device *netdev;
        const struct phylink_mac_ops *ops;

        unsigned long phylink_disable_state; /* bitmask of disables */
        struct phy_device *phydev;
        phy_interface_t link_interface; /* PHY_INTERFACE_xxx */
        u8 link_an_mode;                /* MLO_AN_xxx */
        u8 link_port;                   /* The current non-phy ethtool port */
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported);

        /* The link configuration settings */
        struct phylink_link_state link_config;
        struct gpio_desc *link_gpio;
        struct timer_list link_poll;
        void (*get_fixed_state)(struct net_device *dev,
                                struct phylink_link_state *s);

        struct mutex state_mutex;
        struct phylink_link_state phy_state;
        struct work_struct resolve;

        bool mac_link_dropped;

        struct sfp_bus *sfp_bus;
};

/**
 * phylink_set_port_modes() - set the port type modes in the ethtool mask
 * @mask: ethtool link mode mask
 *
 * Sets all the port type modes in the ethtool mask.  MAC drivers should
 * use this in their 'validate' callback.
 */
void phylink_set_port_modes(unsigned long *mask)
{
        phylink_set(mask, TP);
        phylink_set(mask, AUI);
        phylink_set(mask, MII);
        phylink_set(mask, FIBRE);
        phylink_set(mask, BNC);
        phylink_set(mask, Backplane);
}
EXPORT_SYMBOL_GPL(phylink_set_port_modes);

static int phylink_is_empty_linkmode(const unsigned long *linkmode)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(tmp) = { 0, };

        phylink_set_port_modes(tmp);
        phylink_set(tmp, Autoneg);
        phylink_set(tmp, Pause);
        phylink_set(tmp, Asym_Pause);

        bitmap_andnot(tmp, linkmode, tmp, __ETHTOOL_LINK_MODE_MASK_NBITS);

        return linkmode_empty(tmp);
}

static const char *phylink_an_mode_str(unsigned int mode)
{
        static const char *modestr[] = {
                [MLO_AN_PHY] = "phy",
                [MLO_AN_FIXED] = "fixed",
                [MLO_AN_INBAND] = "inband",
        };

        return mode < ARRAY_SIZE(modestr) ? modestr[mode] : "unknown";
}

static int phylink_validate(struct phylink *pl, unsigned long *supported,
                            struct phylink_link_state *state)
{
        pl->ops->validate(pl->netdev, supported, state);

        return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
}

static int phylink_parse_fixedlink(struct phylink *pl,
                                   struct fwnode_handle *fwnode)
{
        struct fwnode_handle *fixed_node;
        const struct phy_setting *s;
        struct gpio_desc *desc;
        u32 speed;
        int ret;

        fixed_node = fwnode_get_named_child_node(fwnode, "fixed-link");
        if (fixed_node) {
                ret = fwnode_property_read_u32(fixed_node, "speed", &speed);

                pl->link_config.speed = speed;
                pl->link_config.duplex = DUPLEX_HALF;

                if (fwnode_property_read_bool(fixed_node, "full-duplex"))
                        pl->link_config.duplex = DUPLEX_FULL;

                /* We treat the "pause" and "asym-pause" terminology as
                 * defining the link partner's ability. */
                if (fwnode_property_read_bool(fixed_node, "pause"))
                        pl->link_config.pause |= MLO_PAUSE_SYM;
                if (fwnode_property_read_bool(fixed_node, "asym-pause"))
                        pl->link_config.pause |= MLO_PAUSE_ASYM;

                if (ret == 0) {
                        desc = fwnode_get_named_gpiod(fixed_node, "link-gpios",
                                                      0, GPIOD_IN, "?");

                        if (!IS_ERR(desc))
                                pl->link_gpio = desc;
                        else if (desc == ERR_PTR(-EPROBE_DEFER))
                                ret = -EPROBE_DEFER;
                }
                fwnode_handle_put(fixed_node);

                if (ret)
                        return ret;
        } else {
                u32 prop[5];

                ret = fwnode_property_read_u32_array(fwnode, "fixed-link",
                                                     NULL, 0);
                if (ret != ARRAY_SIZE(prop)) {
                        netdev_err(pl->netdev, "broken fixed-link?\n");
                        return -EINVAL;
                }

                ret = fwnode_property_read_u32_array(fwnode, "fixed-link",
                                                     prop, ARRAY_SIZE(prop));
                if (!ret) {
                        pl->link_config.duplex = prop[1] ?
                                                DUPLEX_FULL : DUPLEX_HALF;
                        pl->link_config.speed = prop[2];
                        if (prop[3])
                                pl->link_config.pause |= MLO_PAUSE_SYM;
                        if (prop[4])
                                pl->link_config.pause |= MLO_PAUSE_ASYM;
                }
        }

        if (pl->link_config.speed > SPEED_1000 &&
            pl->link_config.duplex != DUPLEX_FULL)
                netdev_warn(pl->netdev, "fixed link specifies half duplex for %dMbps link?\n",
                            pl->link_config.speed);

        bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
        linkmode_copy(pl->link_config.advertising, pl->supported);
        phylink_validate(pl, pl->supported, &pl->link_config);

        s = phy_lookup_setting(pl->link_config.speed, pl->link_config.duplex,
                               pl->supported, true);
        linkmode_zero(pl->supported);
        phylink_set(pl->supported, MII);
        if (s) {
                __set_bit(s->bit, pl->supported);
        } else {
                netdev_warn(pl->netdev, "fixed link %s duplex %dMbps not recognised\n",
                            pl->link_config.duplex == DUPLEX_FULL ? "full" : "half",
                            pl->link_config.speed);
        }

        linkmode_and(pl->link_config.advertising, pl->link_config.advertising,
                     pl->supported);

        pl->link_config.link = 1;
        pl->link_config.an_complete = 1;

        return 0;
}

static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
{
        struct fwnode_handle *dn;
        const char *managed;

        dn = fwnode_get_named_child_node(fwnode, "fixed-link");
        if (dn || fwnode_property_present(fwnode, "fixed-link"))
                pl->link_an_mode = MLO_AN_FIXED;
        fwnode_handle_put(dn);

        if (fwnode_property_read_string(fwnode, "managed", &managed) == 0 &&
            strcmp(managed, "in-band-status") == 0) {
                if (pl->link_an_mode == MLO_AN_FIXED) {
                        netdev_err(pl->netdev,
                                   "can't use both fixed-link and in-band-status\n");
                        return -EINVAL;
                }

                linkmode_zero(pl->supported);
                phylink_set(pl->supported, MII);
                phylink_set(pl->supported, Autoneg);
                phylink_set(pl->supported, Asym_Pause);
                phylink_set(pl->supported, Pause);
                pl->link_config.an_enabled = true;
                pl->link_an_mode = MLO_AN_INBAND;

                switch (pl->link_config.interface) {
                case PHY_INTERFACE_MODE_SGMII:
                        phylink_set(pl->supported, 10baseT_Half);
                        phylink_set(pl->supported, 10baseT_Full);
                        phylink_set(pl->supported, 100baseT_Half);
                        phylink_set(pl->supported, 100baseT_Full);
                        phylink_set(pl->supported, 1000baseT_Half);
                        phylink_set(pl->supported, 1000baseT_Full);
                        break;

                case PHY_INTERFACE_MODE_1000BASEX:
                        phylink_set(pl->supported, 1000baseX_Full);
                        break;

                case PHY_INTERFACE_MODE_2500BASEX:
                        phylink_set(pl->supported, 2500baseX_Full);
                        break;

                case PHY_INTERFACE_MODE_10GKR:
                        phylink_set(pl->supported, 10baseT_Half);
                        phylink_set(pl->supported, 10baseT_Full);
                        phylink_set(pl->supported, 100baseT_Half);
                        phylink_set(pl->supported, 100baseT_Full);
                        phylink_set(pl->supported, 1000baseT_Half);
                        phylink_set(pl->supported, 1000baseT_Full);
                        phylink_set(pl->supported, 1000baseX_Full);
                        phylink_set(pl->supported, 10000baseKR_Full);
                        phylink_set(pl->supported, 10000baseCR_Full);
                        phylink_set(pl->supported, 10000baseSR_Full);
                        phylink_set(pl->supported, 10000baseLR_Full);
                        phylink_set(pl->supported, 10000baseLRM_Full);
                        phylink_set(pl->supported, 10000baseER_Full);
                        break;

                default:
                        netdev_err(pl->netdev,
                                   "incorrect link mode %s for in-band status\n",
                                   phy_modes(pl->link_config.interface));
                        return -EINVAL;
                }

                linkmode_copy(pl->link_config.advertising, pl->supported);

                if (phylink_validate(pl, pl->supported, &pl->link_config)) {
                        netdev_err(pl->netdev,
                                   "failed to validate link configuration for in-band status\n");
                        return -EINVAL;
                }
        }

        return 0;
}

static void phylink_mac_config(struct phylink *pl,
                               const struct phylink_link_state *state)
{
        netdev_dbg(pl->netdev,
                   "%s: mode=%s/%s/%s/%s adv=%*pb pause=%02x link=%u an=%u\n",
                   __func__, phylink_an_mode_str(pl->link_an_mode),
                   phy_modes(state->interface),
                   phy_speed_to_str(state->speed),
                   phy_duplex_to_str(state->duplex),
                   __ETHTOOL_LINK_MODE_MASK_NBITS, state->advertising,
                   state->pause, state->link, state->an_enabled);

        pl->ops->mac_config(pl->netdev, pl->link_an_mode, state);
}

static void phylink_mac_config_up(struct phylink *pl,
                                  const struct phylink_link_state *state)
{
        if (state->link)
                phylink_mac_config(pl, state);
}

static void phylink_mac_an_restart(struct phylink *pl)
{
        if (pl->link_config.an_enabled &&
            phy_interface_mode_is_8023z(pl->link_config.interface))
                pl->ops->mac_an_restart(pl->netdev);
}

static int phylink_get_mac_state(struct phylink *pl, struct phylink_link_state *state)
{
        struct net_device *ndev = pl->netdev;

        linkmode_copy(state->advertising, pl->link_config.advertising);
        linkmode_zero(state->lp_advertising);
        state->interface = pl->link_config.interface;
        state->an_enabled = pl->link_config.an_enabled;
        state->speed = SPEED_UNKNOWN;
        state->duplex = DUPLEX_UNKNOWN;
        state->pause = MLO_PAUSE_NONE;
        state->an_complete = 0;
        state->link = 1;

        return pl->ops->mac_link_state(ndev, state);
}

/* The fixed state is... fixed except for the link state,
 * which may be determined by a GPIO or a callback.
 */
static void phylink_get_fixed_state(struct phylink *pl, struct phylink_link_state *state)
{
        *state = pl->link_config;
        if (pl->get_fixed_state)
                pl->get_fixed_state(pl->netdev, state);
        else if (pl->link_gpio)
                state->link = !!gpiod_get_value_cansleep(pl->link_gpio);
}

/* Flow control is resolved according to our and the link partners
 * advertisements using the following drawn from the 802.3 specs:
 *  Local device  Link partner
 *  Pause AsymDir Pause AsymDir Result
 *    1     X       1     X     TX+RX
 *    0     1       1     1     RX
 *    1     1       0     1     TX
 */
static void phylink_resolve_flow(struct phylink *pl,
                                 struct phylink_link_state *state)
{
        int new_pause = 0;

        if (pl->link_config.pause & MLO_PAUSE_AN) {
                int pause = 0;

                if (phylink_test(pl->link_config.advertising, Pause))
                        pause |= MLO_PAUSE_SYM;
                if (phylink_test(pl->link_config.advertising, Asym_Pause))
                        pause |= MLO_PAUSE_ASYM;

                pause &= state->pause;

                if (pause & MLO_PAUSE_SYM)
                        new_pause = MLO_PAUSE_TX | MLO_PAUSE_RX;
                else if (pause & MLO_PAUSE_ASYM)
                        new_pause = state->pause & MLO_PAUSE_SYM ?
                                 MLO_PAUSE_RX : MLO_PAUSE_TX;
        } else {
                new_pause = pl->link_config.pause & MLO_PAUSE_TXRX_MASK;
        }

        state->pause &= ~MLO_PAUSE_TXRX_MASK;
        state->pause |= new_pause;
}

static const char *phylink_pause_to_str(int pause)
{
        switch (pause & MLO_PAUSE_TXRX_MASK) {
        case MLO_PAUSE_TX | MLO_PAUSE_RX:
                return "rx/tx";
        case MLO_PAUSE_TX:
                return "tx";
        case MLO_PAUSE_RX:
                return "rx";
        default:
                return "off";
        }
}

static void phylink_resolve(struct work_struct *w)
{
        struct phylink *pl = container_of(w, struct phylink, resolve);
        struct phylink_link_state link_state;
        struct net_device *ndev = pl->netdev;

        mutex_lock(&pl->state_mutex);
        if (pl->phylink_disable_state) {
                pl->mac_link_dropped = false;
                link_state.link = false;
        } else if (pl->mac_link_dropped) {
                link_state.link = false;
        } else {
                switch (pl->link_an_mode) {
                case MLO_AN_PHY:
                        link_state = pl->phy_state;
                        phylink_resolve_flow(pl, &link_state);
                        phylink_mac_config_up(pl, &link_state);
                        break;

                case MLO_AN_FIXED:
                        phylink_get_fixed_state(pl, &link_state);
                        phylink_mac_config_up(pl, &link_state);
                        break;

                case MLO_AN_INBAND:
                        phylink_get_mac_state(pl, &link_state);
                        if (pl->phydev) {
                                bool changed = false;

                                link_state.link = link_state.link &&
                                                  pl->phy_state.link;

                                if (pl->phy_state.interface !=
                                    link_state.interface) {
                                        link_state.interface = pl->phy_state.interface;
                                        changed = true;
                                }

                                /* Propagate the flow control from the PHY
                                 * to the MAC. Also propagate the interface
                                 * if changed.
                                 */
                                if (pl->phy_state.link || changed) {
                                        link_state.pause |= pl->phy_state.pause;
                                        phylink_resolve_flow(pl, &link_state);

                                        phylink_mac_config(pl, &link_state);
                                }
                        }
                        break;
                }
        }

        if (link_state.link != netif_carrier_ok(ndev)) {
                if (!link_state.link) {
                        netif_carrier_off(ndev);
                        pl->ops->mac_link_down(ndev, pl->link_an_mode,
                                               pl->phy_state.interface);
                        netdev_info(ndev, "Link is Down\n");
                } else {
                        pl->ops->mac_link_up(ndev, pl->link_an_mode,
                                             pl->phy_state.interface,
                                             pl->phydev);

                        netif_carrier_on(ndev);

                        netdev_info(ndev,
                                    "Link is Up - %s/%s - flow control %s\n",
                                    phy_speed_to_str(link_state.speed),
                                    phy_duplex_to_str(link_state.duplex),
                                    phylink_pause_to_str(link_state.pause));
                }
        }
        if (!link_state.link && pl->mac_link_dropped) {
                pl->mac_link_dropped = false;
                queue_work(system_power_efficient_wq, &pl->resolve);
        }
        mutex_unlock(&pl->state_mutex);
}

static void phylink_run_resolve(struct phylink *pl)
{
        if (!pl->phylink_disable_state)
                queue_work(system_power_efficient_wq, &pl->resolve);
}

static void phylink_run_resolve_and_disable(struct phylink *pl, int bit)
{
        unsigned long state = pl->phylink_disable_state;

        set_bit(bit, &pl->phylink_disable_state);
        if (state == 0) {
                queue_work(system_power_efficient_wq, &pl->resolve);
                flush_work(&pl->resolve);
        }
}

static void phylink_fixed_poll(struct timer_list *t)
{
        struct phylink *pl = container_of(t, struct phylink, link_poll);

        mod_timer(t, jiffies + HZ);

        phylink_run_resolve(pl);
}

static const struct sfp_upstream_ops sfp_phylink_ops;

static int phylink_register_sfp(struct phylink *pl,
                                struct fwnode_handle *fwnode)
{
        struct fwnode_reference_args ref;
        int ret;

        if (!fwnode)
                return 0;

        ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
                                                 0, 0, &ref);
        if (ret < 0) {
                if (ret == -ENOENT)
                        return 0;

                netdev_err(pl->netdev, "unable to parse \"sfp\" node: %d\n",
                           ret);
                return ret;
        }

        pl->sfp_bus = sfp_register_upstream(ref.fwnode, pl->netdev, pl,
                                            &sfp_phylink_ops);
        if (!pl->sfp_bus)
                return -ENOMEM;

        return 0;
}

/**
 * phylink_create() - create a phylink instance
 * @ndev: a pointer to the &struct net_device
 * @fwnode: a pointer to a &struct fwnode_handle describing the network
 *      interface
 * @iface: the desired link mode defined by &typedef phy_interface_t
 * @ops: a pointer to a &struct phylink_mac_ops for the MAC.
 *
 * Create a new phylink instance, and parse the link parameters found in @np.
 * This will parse in-band modes, fixed-link or SFP configuration.
 *
 * Returns a pointer to a &struct phylink, or an error-pointer value. Users
 * must use IS_ERR() to check for errors from this function.
 */
struct phylink *phylink_create(struct net_device *ndev,
                               struct fwnode_handle *fwnode,
                               phy_interface_t iface,
                               const struct phylink_mac_ops *ops)
{
        struct phylink *pl;
        int ret;

        pl = kzalloc(sizeof(*pl), GFP_KERNEL);
        if (!pl)
                return ERR_PTR(-ENOMEM);

        mutex_init(&pl->state_mutex);
        INIT_WORK(&pl->resolve, phylink_resolve);
        pl->netdev = ndev;
        pl->phy_state.interface = iface;
        pl->link_interface = iface;
        if (iface == PHY_INTERFACE_MODE_MOCA)
                pl->link_port = PORT_BNC;
        else
                pl->link_port = PORT_MII;
        pl->link_config.interface = iface;
        pl->link_config.pause = MLO_PAUSE_AN;
        pl->link_config.speed = SPEED_UNKNOWN;
        pl->link_config.duplex = DUPLEX_UNKNOWN;
        pl->link_config.an_enabled = true;
        pl->ops = ops;
        __set_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
        timer_setup(&pl->link_poll, phylink_fixed_poll, 0);

        bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
        linkmode_copy(pl->link_config.advertising, pl->supported);
        phylink_validate(pl, pl->supported, &pl->link_config);

        ret = phylink_parse_mode(pl, fwnode);
        if (ret < 0) {
                kfree(pl);
                return ERR_PTR(ret);
        }

        if (pl->link_an_mode == MLO_AN_FIXED) {
                ret = phylink_parse_fixedlink(pl, fwnode);
                if (ret < 0) {
                        kfree(pl);
                        return ERR_PTR(ret);
                }
        }

        ret = phylink_register_sfp(pl, fwnode);
        if (ret < 0) {
                kfree(pl);
                return ERR_PTR(ret);
        }

        return pl;
}
EXPORT_SYMBOL_GPL(phylink_create);

/**
 * phylink_destroy() - cleanup and destroy the phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Destroy a phylink instance. Any PHY that has been attached must have been
 * cleaned up via phylink_disconnect_phy() prior to calling this function.
 */
void phylink_destroy(struct phylink *pl)
{
        if (pl->sfp_bus)
                sfp_unregister_upstream(pl->sfp_bus);
        if (!IS_ERR_OR_NULL(pl->link_gpio))
                gpiod_put(pl->link_gpio);

        cancel_work_sync(&pl->resolve);
        kfree(pl);
}
EXPORT_SYMBOL_GPL(phylink_destroy);

static void phylink_phy_change(struct phy_device *phydev, bool up,
                               bool do_carrier)
{
        struct phylink *pl = phydev->phylink;

        mutex_lock(&pl->state_mutex);
        pl->phy_state.speed = phydev->speed;
        pl->phy_state.duplex = phydev->duplex;
        pl->phy_state.pause = MLO_PAUSE_NONE;
        if (phydev->pause)
                pl->phy_state.pause |= MLO_PAUSE_SYM;
        if (phydev->asym_pause)
                pl->phy_state.pause |= MLO_PAUSE_ASYM;
        pl->phy_state.interface = phydev->interface;
        pl->phy_state.link = up;
        mutex_unlock(&pl->state_mutex);

        phylink_run_resolve(pl);

        netdev_dbg(pl->netdev, "phy link %s %s/%s/%s\n", up ? "up" : "down",
                   phy_modes(phydev->interface),
                   phy_speed_to_str(phydev->speed),
                   phy_duplex_to_str(phydev->duplex));
}

static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
{
        struct phylink_link_state config;
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
        int ret;

        memset(&config, 0, sizeof(config));
        linkmode_copy(supported, phy->supported);
        linkmode_copy(config.advertising, phy->advertising);
        config.interface = pl->link_config.interface;

        /*
         * This is the new way of dealing with flow control for PHYs,
         * as described by Timur Tabi in commit 529ed1275263 ("net: phy:
         * phy drivers should not set SUPPORTED_[Asym_]Pause") except
         * using our validate call to the MAC, we rely upon the MAC
         * clearing the bits from both supported and advertising fields.
         */
        if (phylink_test(supported, Pause))
                phylink_set(config.advertising, Pause);
        if (phylink_test(supported, Asym_Pause))
                phylink_set(config.advertising, Asym_Pause);

        ret = phylink_validate(pl, supported, &config);
        if (ret)
                return ret;

        phy->phylink = pl;
        phy->phy_link_change = phylink_phy_change;

        netdev_info(pl->netdev,
                    "PHY [%s] driver [%s]\n", dev_name(&phy->mdio.dev),
                    phy->drv->name);

        mutex_lock(&phy->lock);
        mutex_lock(&pl->state_mutex);
        pl->phydev = phy;
        linkmode_copy(pl->supported, supported);
        linkmode_copy(pl->link_config.advertising, config.advertising);

        /* Restrict the phy advertisement according to the MAC support. */
        linkmode_copy(phy->advertising, config.advertising);
        mutex_unlock(&pl->state_mutex);
        mutex_unlock(&phy->lock);

        netdev_dbg(pl->netdev,
                   "phy: setting supported %*pb advertising %*pb\n",
                   __ETHTOOL_LINK_MODE_MASK_NBITS, pl->supported,
                   __ETHTOOL_LINK_MODE_MASK_NBITS, phy->advertising);

        if (phy_interrupt_is_valid(phy))
                phy_request_interrupt(phy);

        return 0;
}

static int __phylink_connect_phy(struct phylink *pl, struct phy_device *phy,
                phy_interface_t interface)
{
        int ret;

        if (WARN_ON(pl->link_an_mode == MLO_AN_FIXED ||
                    (pl->link_an_mode == MLO_AN_INBAND &&
                     phy_interface_mode_is_8023z(interface))))
                return -EINVAL;

        if (pl->phydev)
                return -EBUSY;

        ret = phy_attach_direct(pl->netdev, phy, 0, interface);
        if (ret)
                return ret;

        ret = phylink_bringup_phy(pl, phy);
        if (ret)
                phy_detach(phy);

        return ret;
}

/**
 * phylink_connect_phy() - connect a PHY to the phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @phy: a pointer to a &struct phy_device.
 *
 * Connect @phy to the phylink instance specified by @pl by calling
 * phy_attach_direct(). Configure the @phy according to the MAC driver's
 * capabilities, start the PHYLIB state machine and enable any interrupts
 * that the PHY supports.
 *
 * This updates the phylink's ethtool supported and advertising link mode
 * masks.
 *
 * Returns 0 on success or a negative errno.
 */
int phylink_connect_phy(struct phylink *pl, struct phy_device *phy)
{
        /* Use PHY device/driver interface */
        if (pl->link_interface == PHY_INTERFACE_MODE_NA) {
                pl->link_interface = phy->interface;
                pl->link_config.interface = pl->link_interface;
        }

        return __phylink_connect_phy(pl, phy, pl->link_interface);
}
EXPORT_SYMBOL_GPL(phylink_connect_phy);

/**
 * phylink_of_phy_connect() - connect the PHY specified in the DT mode.
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @dn: a pointer to a &struct device_node.
 * @flags: PHY-specific flags to communicate to the PHY device driver
 *
 * Connect the phy specified in the device node @dn to the phylink instance
 * specified by @pl. Actions specified in phylink_connect_phy() will be
 * performed.
 *
 * Returns 0 on success or a negative errno.
 */
int phylink_of_phy_connect(struct phylink *pl, struct device_node *dn,
                           u32 flags)
{
        struct device_node *phy_node;
        struct phy_device *phy_dev;
        int ret;

        /* Fixed links and 802.3z are handled without needing a PHY */
        if (pl->link_an_mode == MLO_AN_FIXED ||
            (pl->link_an_mode == MLO_AN_INBAND &&
             phy_interface_mode_is_8023z(pl->link_interface)))
                return 0;

        phy_node = of_parse_phandle(dn, "phy-handle", 0);
        if (!phy_node)
                phy_node = of_parse_phandle(dn, "phy", 0);
        if (!phy_node)
                phy_node = of_parse_phandle(dn, "phy-device", 0);

        if (!phy_node) {
                if (pl->link_an_mode == MLO_AN_PHY)
                        return -ENODEV;
                return 0;
        }

        phy_dev = of_phy_attach(pl->netdev, phy_node, flags,
                                pl->link_interface);
        /* We're done with the phy_node handle */
        of_node_put(phy_node);

        if (!phy_dev)
                return -ENODEV;

        ret = phylink_bringup_phy(pl, phy_dev);
        if (ret)
                phy_detach(phy_dev);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_of_phy_connect);

/**
 * phylink_disconnect_phy() - disconnect any PHY attached to the phylink
 *   instance.
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Disconnect any current PHY from the phylink instance described by @pl.
 */
void phylink_disconnect_phy(struct phylink *pl)
{
        struct phy_device *phy;

        ASSERT_RTNL();

        phy = pl->phydev;
        if (phy) {
                mutex_lock(&phy->lock);
                mutex_lock(&pl->state_mutex);
                pl->phydev = NULL;
                mutex_unlock(&pl->state_mutex);
                mutex_unlock(&phy->lock);
                flush_work(&pl->resolve);

                phy_disconnect(phy);
        }
}
EXPORT_SYMBOL_GPL(phylink_disconnect_phy);

/**
 * phylink_fixed_state_cb() - allow setting a fixed link callback
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @cb: callback to execute to determine the fixed link state.
 *
 * The MAC driver should call this driver when the state of its link
 * can be determined through e.g: an out of band MMIO register.
 */
int phylink_fixed_state_cb(struct phylink *pl,
                           void (*cb)(struct net_device *dev,
                                      struct phylink_link_state *state))
{
        /* It does not make sense to let the link be overriden unless we use
         * MLO_AN_FIXED
         */
        if (pl->link_an_mode != MLO_AN_FIXED)
                return -EINVAL;

        mutex_lock(&pl->state_mutex);
        pl->get_fixed_state = cb;
        mutex_unlock(&pl->state_mutex);

        return 0;
}
EXPORT_SYMBOL_GPL(phylink_fixed_state_cb);

/**
 * phylink_mac_change() - notify phylink of a change in MAC state
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @up: indicates whether the link is currently up.
 *
 * The MAC driver should call this driver when the state of its link
 * changes (eg, link failure, new negotiation results, etc.)
 */
void phylink_mac_change(struct phylink *pl, bool up)
{
        if (!up)
                pl->mac_link_dropped = true;
        phylink_run_resolve(pl);
        netdev_dbg(pl->netdev, "mac link %s\n", up ? "up" : "down");
}
EXPORT_SYMBOL_GPL(phylink_mac_change);

/**
 * phylink_start() - start a phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Start the phylink instance specified by @pl, configuring the MAC for the
 * desired link mode(s) and negotiation style. This should be called from the
 * network device driver's &struct net_device_ops ndo_open() method.
 */
void phylink_start(struct phylink *pl)
{
        ASSERT_RTNL();

        netdev_info(pl->netdev, "configuring for %s/%s link mode\n",
                    phylink_an_mode_str(pl->link_an_mode),
                    phy_modes(pl->link_config.interface));

        /* Always set the carrier off */
        netif_carrier_off(pl->netdev);

        /* Apply the link configuration to the MAC when starting. This allows
         * a fixed-link to start with the correct parameters, and also
         * ensures that we set the appropriate advertisement for Serdes links.
         */
        phylink_resolve_flow(pl, &pl->link_config);
        phylink_mac_config(pl, &pl->link_config);

        /* Restart autonegotiation if using 802.3z to ensure that the link
         * parameters are properly negotiated.  This is necessary for DSA
         * switches using 802.3z negotiation to ensure they see our modes.
         */
        phylink_mac_an_restart(pl);

        clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
        phylink_run_resolve(pl);

        if (pl->link_an_mode == MLO_AN_FIXED && !IS_ERR(pl->link_gpio))
                mod_timer(&pl->link_poll, jiffies + HZ);
        if (pl->sfp_bus)
                sfp_upstream_start(pl->sfp_bus);
        if (pl->phydev)
                phy_start(pl->phydev);
}
EXPORT_SYMBOL_GPL(phylink_start);

/**
 * phylink_stop() - stop a phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Stop the phylink instance specified by @pl. This should be called from the
 * network device driver's &struct net_device_ops ndo_stop() method.  The
 * network device's carrier state should not be changed prior to calling this
 * function.
 */
void phylink_stop(struct phylink *pl)
{
        ASSERT_RTNL();

        if (pl->phydev)
                phy_stop(pl->phydev);
        if (pl->sfp_bus)
                sfp_upstream_stop(pl->sfp_bus);
        if (pl->link_an_mode == MLO_AN_FIXED && !IS_ERR(pl->link_gpio))
                del_timer_sync(&pl->link_poll);

        phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_STOPPED);
}
EXPORT_SYMBOL_GPL(phylink_stop);

/**
 * phylink_ethtool_get_wol() - get the wake on lan parameters for the PHY
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @wol: a pointer to &struct ethtool_wolinfo to hold the read parameters
 *
 * Read the wake on lan parameters from the PHY attached to the phylink
 * instance specified by @pl. If no PHY is currently attached, report no
 * support for wake on lan.
 */
void phylink_ethtool_get_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
{
        ASSERT_RTNL();

        wol->supported = 0;
        wol->wolopts = 0;

        if (pl->phydev)
                phy_ethtool_get_wol(pl->phydev, wol);
}
EXPORT_SYMBOL_GPL(phylink_ethtool_get_wol);

/**
 * phylink_ethtool_set_wol() - set wake on lan parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @wol: a pointer to &struct ethtool_wolinfo for the desired parameters
 *
 * Set the wake on lan parameters for the PHY attached to the phylink
 * instance specified by @pl. If no PHY is attached, returns %EOPNOTSUPP
 * error.
 *
 * Returns zero on success or negative errno code.
 */
int phylink_ethtool_set_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
{
        int ret = -EOPNOTSUPP;

        ASSERT_RTNL();

        if (pl->phydev)
                ret = phy_ethtool_set_wol(pl->phydev, wol);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_set_wol);

static void phylink_merge_link_mode(unsigned long *dst, const unsigned long *b)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(mask);

        linkmode_zero(mask);
        phylink_set_port_modes(mask);

        linkmode_and(dst, dst, mask);
        linkmode_or(dst, dst, b);
}

static void phylink_get_ksettings(const struct phylink_link_state *state,
                                  struct ethtool_link_ksettings *kset)
{
        phylink_merge_link_mode(kset->link_modes.advertising, state->advertising);
        linkmode_copy(kset->link_modes.lp_advertising, state->lp_advertising);
        kset->base.speed = state->speed;
        kset->base.duplex = state->duplex;
        kset->base.autoneg = state->an_enabled ? AUTONEG_ENABLE :
                                AUTONEG_DISABLE;
}

/**
 * phylink_ethtool_ksettings_get() - get the current link settings
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @kset: a pointer to a &struct ethtool_link_ksettings to hold link settings
 *
 * Read the current link settings for the phylink instance specified by @pl.
 * This will be the link settings read from the MAC, PHY or fixed link
 * settings depending on the current negotiation mode.
 */
int phylink_ethtool_ksettings_get(struct phylink *pl,
                                  struct ethtool_link_ksettings *kset)
{
        struct phylink_link_state link_state;

        ASSERT_RTNL();

        if (pl->phydev) {
                phy_ethtool_ksettings_get(pl->phydev, kset);
        } else {
                kset->base.port = pl->link_port;
        }

        linkmode_copy(kset->link_modes.supported, pl->supported);

        switch (pl->link_an_mode) {
        case MLO_AN_FIXED:
                /* We are using fixed settings. Report these as the
                 * current link settings - and note that these also
                 * represent the supported speeds/duplex/pause modes.
                 */
                phylink_get_fixed_state(pl, &link_state);
                phylink_get_ksettings(&link_state, kset);
                break;

        case MLO_AN_INBAND:
                /* If there is a phy attached, then use the reported
                 * settings from the phy with no modification.
                 */
                if (pl->phydev)
                        break;

                phylink_get_mac_state(pl, &link_state);

                /* The MAC is reporting the link results from its own PCS
                 * layer via in-band status. Report these as the current
                 * link settings.
                 */
                phylink_get_ksettings(&link_state, kset);
                break;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_get);

/**
 * phylink_ethtool_ksettings_set() - set the link settings
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @kset: a pointer to a &struct ethtool_link_ksettings for the desired modes
 */
int phylink_ethtool_ksettings_set(struct phylink *pl,
                                  const struct ethtool_link_ksettings *kset)
{
        struct ethtool_link_ksettings our_kset;
        struct phylink_link_state config;
        int ret;

        ASSERT_RTNL();

        if (kset->base.autoneg != AUTONEG_DISABLE &&
            kset->base.autoneg != AUTONEG_ENABLE)
                return -EINVAL;

        config = pl->link_config;

        /* Mask out unsupported advertisements */
        linkmode_and(config.advertising, kset->link_modes.advertising,
                     pl->supported);

        /* FIXME: should we reject autoneg if phy/mac does not support it? */
        if (kset->base.autoneg == AUTONEG_DISABLE) {
                const struct phy_setting *s;

                /* Autonegotiation disabled, select a suitable speed and
                 * duplex.
                 */
                s = phy_lookup_setting(kset->base.speed, kset->base.duplex,
                                       pl->supported, false);
                if (!s)
                        return -EINVAL;

                /* If we have a fixed link (as specified by firmware), refuse
                 * to change link parameters.
                 */
                if (pl->link_an_mode == MLO_AN_FIXED &&
                    (s->speed != pl->link_config.speed ||
                     s->duplex != pl->link_config.duplex))
                        return -EINVAL;

                config.speed = s->speed;
                config.duplex = s->duplex;
                config.an_enabled = false;

                __clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising);
        } else {
                /* If we have a fixed link, refuse to enable autonegotiation */
                if (pl->link_an_mode == MLO_AN_FIXED)
                        return -EINVAL;

                config.speed = SPEED_UNKNOWN;
                config.duplex = DUPLEX_UNKNOWN;
                config.an_enabled = true;

                __set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising);
        }

        if (phylink_validate(pl, pl->supported, &config))
                return -EINVAL;

        /* If autonegotiation is enabled, we must have an advertisement */
        if (config.an_enabled && phylink_is_empty_linkmode(config.advertising))
                return -EINVAL;

        our_kset = *kset;
        linkmode_copy(our_kset.link_modes.advertising, config.advertising);
        our_kset.base.speed = config.speed;
        our_kset.base.duplex = config.duplex;

        /* If we have a PHY, configure the phy */
        if (pl->phydev) {
                ret = phy_ethtool_ksettings_set(pl->phydev, &our_kset);
                if (ret)
                        return ret;
        }

        mutex_lock(&pl->state_mutex);
        /* Configure the MAC to match the new settings */
        linkmode_copy(pl->link_config.advertising, our_kset.link_modes.advertising);
        pl->link_config.interface = config.interface;
        pl->link_config.speed = our_kset.base.speed;
        pl->link_config.duplex = our_kset.base.duplex;
        pl->link_config.an_enabled = our_kset.base.autoneg != AUTONEG_DISABLE;

        if (!test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state)) {
                phylink_mac_config(pl, &pl->link_config);
                phylink_mac_an_restart(pl);
        }
        mutex_unlock(&pl->state_mutex);

        return 0;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_set);

/**
 * phylink_ethtool_nway_reset() - restart negotiation
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Restart negotiation for the phylink instance specified by @pl. This will
 * cause any attached phy to restart negotiation with the link partner, and
 * if the MAC is in a BaseX mode, the MAC will also be requested to restart
 * negotiation.
 *
 * Returns zero on success, or negative error code.
 */
int phylink_ethtool_nway_reset(struct phylink *pl)
{
        int ret = 0;

        ASSERT_RTNL();

        if (pl->phydev)
                ret = phy_restart_aneg(pl->phydev);
        phylink_mac_an_restart(pl);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_nway_reset);

/**
 * phylink_ethtool_get_pauseparam() - get the current pause parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pause: a pointer to a &struct ethtool_pauseparam
 */
void phylink_ethtool_get_pauseparam(struct phylink *pl,
                                    struct ethtool_pauseparam *pause)
{
        ASSERT_RTNL();

        pause->autoneg = !!(pl->link_config.pause & MLO_PAUSE_AN);
        pause->rx_pause = !!(pl->link_config.pause & MLO_PAUSE_RX);
        pause->tx_pause = !!(pl->link_config.pause & MLO_PAUSE_TX);
}
EXPORT_SYMBOL_GPL(phylink_ethtool_get_pauseparam);

/**
 * phylink_ethtool_set_pauseparam() - set the current pause parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pause: a pointer to a &struct ethtool_pauseparam
 */
int phylink_ethtool_set_pauseparam(struct phylink *pl,
                                   struct ethtool_pauseparam *pause)
{
        struct phylink_link_state *config = &pl->link_config;

        ASSERT_RTNL();

        if (!phylink_test(pl->supported, Pause) &&
            !phylink_test(pl->supported, Asym_Pause))
                return -EOPNOTSUPP;

        if (!phylink_test(pl->supported, Asym_Pause) &&
            !pause->autoneg && pause->rx_pause != pause->tx_pause)
                return -EINVAL;

        config->pause &= ~(MLO_PAUSE_AN | MLO_PAUSE_TXRX_MASK);

        if (pause->autoneg)
                config->pause |= MLO_PAUSE_AN;
        if (pause->rx_pause)
                config->pause |= MLO_PAUSE_RX;
        if (pause->tx_pause)
                config->pause |= MLO_PAUSE_TX;

        if (!test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state)) {
                switch (pl->link_an_mode) {
                case MLO_AN_PHY:
                        /* Silently mark the carrier down, and then trigger a resolve */
                        netif_carrier_off(pl->netdev);
                        phylink_run_resolve(pl);
                        break;

                case MLO_AN_FIXED:
                        /* Should we allow fixed links to change against the config? */
                        phylink_resolve_flow(pl, config);
                        phylink_mac_config(pl, config);
                        break;

                case MLO_AN_INBAND:
                        phylink_mac_config(pl, config);
                        phylink_mac_an_restart(pl);
                        break;
                }
        }

        return 0;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_set_pauseparam);

/**
 * phylink_ethtool_get_eee_err() - read the energy efficient ethernet error
 *   counter
 * @pl: a pointer to a &struct phylink returned from phylink_create().
 *
 * Read the Energy Efficient Ethernet error counter from the PHY associated
 * with the phylink instance specified by @pl.
 *
 * Returns positive error counter value, or negative error code.
 */
int phylink_get_eee_err(struct phylink *pl)
{
        int ret = 0;

        ASSERT_RTNL();

        if (pl->phydev)
                ret = phy_get_eee_err(pl->phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_get_eee_err);

/**
 * phylink_init_eee() - init and check the EEE features
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @clk_stop_enable: allow PHY to stop receive clock
 *
 * Must be called either with RTNL held or within mac_link_up()
 */
int phylink_init_eee(struct phylink *pl, bool clk_stop_enable)
{
        int ret = -EOPNOTSUPP;

        if (pl->phydev)
                ret = phy_init_eee(pl->phydev, clk_stop_enable);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_init_eee);

/**
 * phylink_ethtool_get_eee() - read the energy efficient ethernet parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @eee: a pointer to a &struct ethtool_eee for the read parameters
 */
int phylink_ethtool_get_eee(struct phylink *pl, struct ethtool_eee *eee)
{
        int ret = -EOPNOTSUPP;

        ASSERT_RTNL();

        if (pl->phydev)
                ret = phy_ethtool_get_eee(pl->phydev, eee);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_get_eee);

/**
 * phylink_ethtool_set_eee() - set the energy efficient ethernet parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @eee: a pointer to a &struct ethtool_eee for the desired parameters
 */
int phylink_ethtool_set_eee(struct phylink *pl, struct ethtool_eee *eee)
{
        int ret = -EOPNOTSUPP;

        ASSERT_RTNL();

        if (pl->phydev)
                ret = phy_ethtool_set_eee(pl->phydev, eee);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_set_eee);

/* This emulates MII registers for a fixed-mode phy operating as per the
 * passed in state. "aneg" defines if we report negotiation is possible.
 *
 * FIXME: should deal with negotiation state too.
 */
static int phylink_mii_emul_read(struct net_device *ndev, unsigned int reg,
                                 struct phylink_link_state *state, bool aneg)
{
        struct fixed_phy_status fs;
        int val;

        fs.link = state->link;
        fs.speed = state->speed;
        fs.duplex = state->duplex;
        fs.pause = state->pause & MLO_PAUSE_SYM;
        fs.asym_pause = state->pause & MLO_PAUSE_ASYM;

        val = swphy_read_reg(reg, &fs);
        if (reg == MII_BMSR) {
                if (!state->an_complete)
                        val &= ~BMSR_ANEGCOMPLETE;
                if (!aneg)
                        val &= ~BMSR_ANEGCAPABLE;
        }
        return val;
}

static int phylink_phy_read(struct phylink *pl, unsigned int phy_id,
                            unsigned int reg)
{
        struct phy_device *phydev = pl->phydev;
        int prtad, devad;

        if (mdio_phy_id_is_c45(phy_id)) {
                prtad = mdio_phy_id_prtad(phy_id);
                devad = mdio_phy_id_devad(phy_id);
                devad = MII_ADDR_C45 | devad << 16 | reg;
        } else if (phydev->is_c45) {
                switch (reg) {
                case MII_BMCR:
                case MII_BMSR:
                case MII_PHYSID1:
                case MII_PHYSID2:
                        devad = __ffs(phydev->c45_ids.devices_in_package);
                        break;
                case MII_ADVERTISE:
                case MII_LPA:
                        if (!(phydev->c45_ids.devices_in_package & MDIO_DEVS_AN))
                                return -EINVAL;
                        devad = MDIO_MMD_AN;
                        if (reg == MII_ADVERTISE)
                                reg = MDIO_AN_ADVERTISE;
                        else
                                reg = MDIO_AN_LPA;
                        break;
                default:
                        return -EINVAL;
                }
                prtad = phy_id;
                devad = MII_ADDR_C45 | devad << 16 | reg;
        } else {
                prtad = phy_id;
                devad = reg;
        }
        return mdiobus_read(pl->phydev->mdio.bus, prtad, devad);
}

static int phylink_phy_write(struct phylink *pl, unsigned int phy_id,
                             unsigned int reg, unsigned int val)
{
        struct phy_device *phydev = pl->phydev;
        int prtad, devad;

        if (mdio_phy_id_is_c45(phy_id)) {
                prtad = mdio_phy_id_prtad(phy_id);
                devad = mdio_phy_id_devad(phy_id);
                devad = MII_ADDR_C45 | devad << 16 | reg;
        } else if (phydev->is_c45) {
                switch (reg) {
                case MII_BMCR:
                case MII_BMSR:
                case MII_PHYSID1:
                case MII_PHYSID2:
                        devad = __ffs(phydev->c45_ids.devices_in_package);
                        break;
                case MII_ADVERTISE:
                case MII_LPA:
                        if (!(phydev->c45_ids.devices_in_package & MDIO_DEVS_AN))
                                return -EINVAL;
                        devad = MDIO_MMD_AN;
                        if (reg == MII_ADVERTISE)
                                reg = MDIO_AN_ADVERTISE;
                        else
                                reg = MDIO_AN_LPA;
                        break;
                default:
                        return -EINVAL;
                }
                prtad = phy_id;
                devad = MII_ADDR_C45 | devad << 16 | reg;
        } else {
                prtad = phy_id;
                devad = reg;
        }

        return mdiobus_write(phydev->mdio.bus, prtad, devad, val);
}

static int phylink_mii_read(struct phylink *pl, unsigned int phy_id,
                            unsigned int reg)
{
        struct phylink_link_state state;
        int val = 0xffff;

        switch (pl->link_an_mode) {
        case MLO_AN_FIXED:
                if (phy_id == 0) {
                        phylink_get_fixed_state(pl, &state);
                        val = phylink_mii_emul_read(pl->netdev, reg, &state,
                                                    true);
                }
                break;

        case MLO_AN_PHY:
                return -EOPNOTSUPP;

        case MLO_AN_INBAND:
                if (phy_id == 0) {
                        val = phylink_get_mac_state(pl, &state);
                        if (val < 0)
                                return val;

                        val = phylink_mii_emul_read(pl->netdev, reg, &state,
                                                    true);
                }
                break;
        }

        return val & 0xffff;
}

static int phylink_mii_write(struct phylink *pl, unsigned int phy_id,
                             unsigned int reg, unsigned int val)
{
        switch (pl->link_an_mode) {
        case MLO_AN_FIXED:
                break;

        case MLO_AN_PHY:
                return -EOPNOTSUPP;

        case MLO_AN_INBAND:
                break;
        }

        return 0;
}

/**
 * phylink_mii_ioctl() - generic mii ioctl interface
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @ifr: a pointer to a &struct ifreq for socket ioctls
 * @cmd: ioctl cmd to execute
 *
 * Perform the specified MII ioctl on the PHY attached to the phylink instance
 * specified by @pl. If no PHY is attached, emulate the presence of the PHY.
 *
 * Returns: zero on success or negative error code.
 *
 * %SIOCGMIIPHY:
 *  read register from the current PHY.
 * %SIOCGMIIREG:
 *  read register from the specified PHY.
 * %SIOCSMIIREG:
 *  set a register on the specified PHY.
 */
int phylink_mii_ioctl(struct phylink *pl, struct ifreq *ifr, int cmd)
{
        struct mii_ioctl_data *mii = if_mii(ifr);
        int  ret;

        ASSERT_RTNL();

        if (pl->phydev) {
                /* PHYs only exist for MLO_AN_PHY and SGMII */
                switch (cmd) {
                case SIOCGMIIPHY:
                        mii->phy_id = pl->phydev->mdio.addr;
                        /* fall through */

                case SIOCGMIIREG:
                        ret = phylink_phy_read(pl, mii->phy_id, mii->reg_num);
                        if (ret >= 0) {
                                mii->val_out = ret;
                                ret = 0;
                        }
                        break;

                case SIOCSMIIREG:
                        ret = phylink_phy_write(pl, mii->phy_id, mii->reg_num,
                                                mii->val_in);
                        break;

                default:
                        ret = phy_mii_ioctl(pl->phydev, ifr, cmd);
                        break;
                }
        } else {
                switch (cmd) {
                case SIOCGMIIPHY:
                        mii->phy_id = 0;
                        /* fall through */

                case SIOCGMIIREG:
                        ret = phylink_mii_read(pl, mii->phy_id, mii->reg_num);
                        if (ret >= 0) {
                                mii->val_out = ret;
                                ret = 0;
                        }
                        break;

                case SIOCSMIIREG:
                        ret = phylink_mii_write(pl, mii->phy_id, mii->reg_num,
                                                mii->val_in);
                        break;

                default:
                        ret = -EOPNOTSUPP;
                        break;
                }
        }

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_mii_ioctl);

static int phylink_sfp_module_insert(void *upstream,
                                     const struct sfp_eeprom_id *id)
{
        struct phylink *pl = upstream;
        __ETHTOOL_DECLARE_LINK_MODE_MASK(support) = { 0, };
        struct phylink_link_state config;
        phy_interface_t iface;
        int ret = 0;
        bool changed;
        u8 port;

        ASSERT_RTNL();

        sfp_parse_support(pl->sfp_bus, id, support);
        port = sfp_parse_port(pl->sfp_bus, id, support);

        memset(&config, 0, sizeof(config));
        linkmode_copy(config.advertising, support);
        config.interface = PHY_INTERFACE_MODE_NA;
        config.speed = SPEED_UNKNOWN;
        config.duplex = DUPLEX_UNKNOWN;
        config.pause = MLO_PAUSE_AN;
        config.an_enabled = pl->link_config.an_enabled;

        /* Ignore errors if we're expecting a PHY to attach later */
        ret = phylink_validate(pl, support, &config);
        if (ret) {
                netdev_err(pl->netdev, "validation with support %*pb failed: %d\n",
                           __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
                return ret;
        }

        iface = sfp_select_interface(pl->sfp_bus, id, config.advertising);
        if (iface == PHY_INTERFACE_MODE_NA) {
                netdev_err(pl->netdev,
                           "selection of interface failed, advertisement %*pb\n",
                           __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
                return -EINVAL;
        }

        config.interface = iface;
        ret = phylink_validate(pl, support, &config);
        if (ret) {
                netdev_err(pl->netdev, "validation of %s/%s with support %*pb failed: %d\n",
                           phylink_an_mode_str(MLO_AN_INBAND),
                           phy_modes(config.interface),
                           __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
                return ret;
        }

        netdev_dbg(pl->netdev, "requesting link mode %s/%s with support %*pb\n",
                   phylink_an_mode_str(MLO_AN_INBAND),
                   phy_modes(config.interface),
                   __ETHTOOL_LINK_MODE_MASK_NBITS, support);

        if (phy_interface_mode_is_8023z(iface) && pl->phydev)
                return -EINVAL;

        changed = !bitmap_equal(pl->supported, support,
                                __ETHTOOL_LINK_MODE_MASK_NBITS);
        if (changed) {
                linkmode_copy(pl->supported, support);
                linkmode_copy(pl->link_config.advertising, config.advertising);
        }

        if (pl->link_an_mode != MLO_AN_INBAND ||
            pl->link_config.interface != config.interface) {
                pl->link_config.interface = config.interface;
                pl->link_an_mode = MLO_AN_INBAND;

                changed = true;

                netdev_info(pl->netdev, "switched to %s/%s link mode\n",
                            phylink_an_mode_str(MLO_AN_INBAND),
                            phy_modes(config.interface));
        }

        pl->link_port = port;

        if (changed && !test_bit(PHYLINK_DISABLE_STOPPED,
                                 &pl->phylink_disable_state))
                phylink_mac_config(pl, &pl->link_config);

        return ret;
}

static void phylink_sfp_link_down(void *upstream)
{
        struct phylink *pl = upstream;

        ASSERT_RTNL();

        phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_LINK);
}

static void phylink_sfp_link_up(void *upstream)
{
        struct phylink *pl = upstream;

        ASSERT_RTNL();

        clear_bit(PHYLINK_DISABLE_LINK, &pl->phylink_disable_state);
        phylink_run_resolve(pl);
}

static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
{
        struct phylink *pl = upstream;

        return __phylink_connect_phy(upstream, phy, pl->link_config.interface);
}

static void phylink_sfp_disconnect_phy(void *upstream)
{
        phylink_disconnect_phy(upstream);
}

static const struct sfp_upstream_ops sfp_phylink_ops = {
        .module_insert = phylink_sfp_module_insert,
        .link_up = phylink_sfp_link_up,
        .link_down = phylink_sfp_link_down,
        .connect_phy = phylink_sfp_connect_phy,
        .disconnect_phy = phylink_sfp_disconnect_phy,
};

/* Helpers for MAC drivers */

/**
 * phylink_helper_basex_speed() - 1000BaseX/2500BaseX helper
 * @state: a pointer to a &struct phylink_link_state
 *
 * Inspect the interface mode, advertising mask or forced speed and
 * decide whether to run at 2.5Gbit or 1Gbit appropriately, switching
 * the interface mode to suit.  @state->interface is appropriately
 * updated, and the advertising mask has the "other" baseX_Full flag
 * cleared.
 */
void phylink_helper_basex_speed(struct phylink_link_state *state)
{
        if (phy_interface_mode_is_8023z(state->interface)) {
                bool want_2500 = state->an_enabled ?
                        phylink_test(state->advertising, 2500baseX_Full) :
                        state->speed == SPEED_2500;

                if (want_2500) {
                        phylink_clear(state->advertising, 1000baseX_Full);
                        state->interface = PHY_INTERFACE_MODE_2500BASEX;
                } else {
                        phylink_clear(state->advertising, 2500baseX_Full);
                        state->interface = PHY_INTERFACE_MODE_1000BASEX;
                }
        }
}
EXPORT_SYMBOL_GPL(phylink_helper_basex_speed);

MODULE_LICENSE("GPL v2");