// SPDX-License-Identifier: GPL-2.0+
/*
 * Core PHY library, taken from phy.c
 */
#include <linux/export.h>
#include <linux/phy.h>
#include <linux/phy_port.h>
#include <linux/of.h>

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

/**
 * phy_speed_to_str - Return a string representing the PHY link speed
 *
 * @speed: Speed of the link
 */
const char *phy_speed_to_str(int speed)
{
        BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 125,
                "Enum ethtool_link_mode_bit_indices and phylib are out of sync. "
                "If a speed or mode has been added please update phy_speed_to_str "
                "and the PHY settings array.\n");

        switch (speed) {
        case SPEED_10:
                return "10Mbps";
        case SPEED_100:
                return "100Mbps";
        case SPEED_1000:
                return "1Gbps";
        case SPEED_2500:
                return "2.5Gbps";
        case SPEED_5000:
                return "5Gbps";
        case SPEED_10000:
                return "10Gbps";
        case SPEED_14000:
                return "14Gbps";
        case SPEED_20000:
                return "20Gbps";
        case SPEED_25000:
                return "25Gbps";
        case SPEED_40000:
                return "40Gbps";
        case SPEED_50000:
                return "50Gbps";
        case SPEED_56000:
                return "56Gbps";
        case SPEED_80000:
                return "80Gbps";
        case SPEED_100000:
                return "100Gbps";
        case SPEED_200000:
                return "200Gbps";
        case SPEED_400000:
                return "400Gbps";
        case SPEED_800000:
                return "800Gbps";
        case SPEED_1600000:
                return "1600Gbps";
        case SPEED_UNKNOWN:
                return "Unknown";
        default:
                return "Unsupported (update phy-core.c)";
        }
}
EXPORT_SYMBOL_GPL(phy_speed_to_str);

/**
 * phy_duplex_to_str - Return string describing the duplex
 *
 * @duplex: Duplex setting to describe
 */
const char *phy_duplex_to_str(unsigned int duplex)
{
        if (duplex == DUPLEX_HALF)
                return "Half";
        if (duplex == DUPLEX_FULL)
                return "Full";
        if (duplex == DUPLEX_UNKNOWN)
                return "Unknown";
        return "Unsupported (update phy-core.c)";
}
EXPORT_SYMBOL_GPL(phy_duplex_to_str);

/**
 * phy_rate_matching_to_str - Return a string describing the rate matching
 *
 * @rate_matching: Type of rate matching to describe
 */
const char *phy_rate_matching_to_str(int rate_matching)
{
        switch (rate_matching) {
        case RATE_MATCH_NONE:
                return "none";
        case RATE_MATCH_PAUSE:
                return "pause";
        case RATE_MATCH_CRS:
                return "crs";
        case RATE_MATCH_OPEN_LOOP:
                return "open-loop";
        }
        return "Unsupported (update phy-core.c)";
}
EXPORT_SYMBOL_GPL(phy_rate_matching_to_str);

/**
 * phy_fix_phy_mode_for_mac_delays - Convenience function for fixing PHY
 * mode based on whether mac adds internal delay
 *
 * @interface: The current interface mode of the port
 * @mac_txid: True if the mac adds internal tx delay
 * @mac_rxid: True if the mac adds internal rx delay
 *
 * Return: fixed PHY mode, or PHY_INTERFACE_MODE_NA if the interface can
 * not apply the internal delay
 */
phy_interface_t phy_fix_phy_mode_for_mac_delays(phy_interface_t interface,
                                                bool mac_txid, bool mac_rxid)
{
        if (!phy_interface_mode_is_rgmii(interface))
                return interface;

        if (mac_txid && mac_rxid) {
                if (interface == PHY_INTERFACE_MODE_RGMII_ID)
                        return PHY_INTERFACE_MODE_RGMII;
                return PHY_INTERFACE_MODE_NA;
        }

        if (mac_txid) {
                if (interface == PHY_INTERFACE_MODE_RGMII_ID)
                        return PHY_INTERFACE_MODE_RGMII_RXID;
                if (interface == PHY_INTERFACE_MODE_RGMII_TXID)
                        return PHY_INTERFACE_MODE_RGMII;
                return PHY_INTERFACE_MODE_NA;
        }

        if (mac_rxid) {
                if (interface == PHY_INTERFACE_MODE_RGMII_ID)
                        return PHY_INTERFACE_MODE_RGMII_TXID;
                if (interface == PHY_INTERFACE_MODE_RGMII_RXID)
                        return PHY_INTERFACE_MODE_RGMII;
                return PHY_INTERFACE_MODE_NA;
        }

        return interface;
}
EXPORT_SYMBOL_GPL(phy_fix_phy_mode_for_mac_delays);

/**
 * phy_interface_num_ports - Return the number of links that can be carried by
 *                           a given MAC-PHY physical link. Returns 0 if this is
 *                           unknown, the number of links else.
 *
 * @interface: The interface mode we want to get the number of ports
 */
int phy_interface_num_ports(phy_interface_t interface)
{
        switch (interface) {
        case PHY_INTERFACE_MODE_NA:
                return 0;
        case PHY_INTERFACE_MODE_INTERNAL:
        case PHY_INTERFACE_MODE_MII:
        case PHY_INTERFACE_MODE_MIILITE:
        case PHY_INTERFACE_MODE_GMII:
        case PHY_INTERFACE_MODE_TBI:
        case PHY_INTERFACE_MODE_REVMII:
        case PHY_INTERFACE_MODE_RMII:
        case PHY_INTERFACE_MODE_REVRMII:
        case PHY_INTERFACE_MODE_RGMII:
        case PHY_INTERFACE_MODE_RGMII_ID:
        case PHY_INTERFACE_MODE_RGMII_RXID:
        case PHY_INTERFACE_MODE_RGMII_TXID:
        case PHY_INTERFACE_MODE_RTBI:
        case PHY_INTERFACE_MODE_XGMII:
        case PHY_INTERFACE_MODE_XLGMII:
        case PHY_INTERFACE_MODE_MOCA:
        case PHY_INTERFACE_MODE_TRGMII:
        case PHY_INTERFACE_MODE_USXGMII:
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_SMII:
        case PHY_INTERFACE_MODE_1000BASEX:
        case PHY_INTERFACE_MODE_2500BASEX:
        case PHY_INTERFACE_MODE_5GBASER:
        case PHY_INTERFACE_MODE_10GBASER:
        case PHY_INTERFACE_MODE_25GBASER:
        case PHY_INTERFACE_MODE_10GKR:
        case PHY_INTERFACE_MODE_100BASEX:
        case PHY_INTERFACE_MODE_RXAUI:
        case PHY_INTERFACE_MODE_XAUI:
        case PHY_INTERFACE_MODE_1000BASEKX:
        case PHY_INTERFACE_MODE_50GBASER:
        case PHY_INTERFACE_MODE_LAUI:
        case PHY_INTERFACE_MODE_100GBASEP:
                return 1;
        case PHY_INTERFACE_MODE_QSGMII:
        case PHY_INTERFACE_MODE_QUSGMII:
        case PHY_INTERFACE_MODE_10G_QXGMII:
                return 4;
        case PHY_INTERFACE_MODE_PSGMII:
                return 5;
        case PHY_INTERFACE_MODE_MAX:
                WARN_ONCE(1, "PHY_INTERFACE_MODE_MAX isn't a valid interface mode");
                return 0;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(phy_interface_num_ports);

static void __set_phy_supported(struct phy_device *phydev, u32 max_speed)
{
        struct phy_port *port;

        phy_caps_linkmode_max_speed(max_speed, phydev->supported);

        phy_for_each_port(phydev, port)
                phy_caps_linkmode_max_speed(max_speed, port->supported);
}

/**
 * phy_set_max_speed - Set the maximum speed the PHY should support
 *
 * @phydev: The phy_device struct
 * @max_speed: Maximum speed
 *
 * The PHY might be more capable than the MAC. For example a Fast Ethernet
 * is connected to a 1G PHY. This function allows the MAC to indicate its
 * maximum speed, and so limit what the PHY will advertise.
 */
void phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
{
        __set_phy_supported(phydev, max_speed);

        phy_advertise_supported(phydev);
}
EXPORT_SYMBOL(phy_set_max_speed);

void of_set_phy_supported(struct phy_device *phydev)
{
        struct device_node *node = phydev->mdio.dev.of_node;
        u32 max_speed;

        if (!IS_ENABLED(CONFIG_OF_MDIO))
                return;

        if (!node)
                return;

        if (!of_property_read_u32(node, "max-speed", &max_speed))
                __set_phy_supported(phydev, max_speed);
}

void of_set_phy_eee_broken(struct phy_device *phydev)
{
        struct device_node *node = phydev->mdio.dev.of_node;
        unsigned long *modes = phydev->eee_disabled_modes;

        if (!IS_ENABLED(CONFIG_OF_MDIO) || !node)
                return;

        linkmode_zero(modes);

        if (of_property_read_bool(node, "eee-broken-100tx"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, modes);
        if (of_property_read_bool(node, "eee-broken-1000t"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, modes);
        if (of_property_read_bool(node, "eee-broken-10gt"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseT_Full_BIT, modes);
        if (of_property_read_bool(node, "eee-broken-1000kx"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseKX_Full_BIT, modes);
        if (of_property_read_bool(node, "eee-broken-10gkx4"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT, modes);
        if (of_property_read_bool(node, "eee-broken-10gkr"))
                linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseKR_Full_BIT, modes);
}

/**
 * of_set_phy_timing_role - Set the master/slave mode of the PHY
 *
 * @phydev: The phy_device struct
 *
 * Set master/slave configuration of the PHY based on the device tree.
 */
void of_set_phy_timing_role(struct phy_device *phydev)
{
        struct device_node *node = phydev->mdio.dev.of_node;
        const char *master;

        if (!IS_ENABLED(CONFIG_OF_MDIO))
                return;

        if (!node)
                return;

        if (of_property_read_string(node, "timing-role", &master))
                return;

        if (strcmp(master, "forced-master") == 0)
                phydev->master_slave_set = MASTER_SLAVE_CFG_MASTER_FORCE;
        else if (strcmp(master, "forced-slave") == 0)
                phydev->master_slave_set = MASTER_SLAVE_CFG_SLAVE_FORCE;
        else if (strcmp(master, "preferred-master") == 0)
                phydev->master_slave_set = MASTER_SLAVE_CFG_MASTER_PREFERRED;
        else if (strcmp(master, "preferred-slave") == 0)
                phydev->master_slave_set = MASTER_SLAVE_CFG_SLAVE_PREFERRED;
        else
                phydev_warn(phydev, "Unknown master-slave mode %s\n", master);
}

/**
 * phy_resolve_aneg_pause - Determine pause autoneg results
 *
 * @phydev: The phy_device struct
 *
 * Once autoneg has completed the local pause settings can be
 * resolved.  Determine if pause and asymmetric pause should be used
 * by the MAC.
 */

void phy_resolve_aneg_pause(struct phy_device *phydev)
{
        if (phydev->duplex == DUPLEX_FULL) {
                phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
                                                  phydev->lp_advertising);
                phydev->asym_pause = linkmode_test_bit(
                        ETHTOOL_LINK_MODE_Asym_Pause_BIT,
                        phydev->lp_advertising);
        }
}
EXPORT_SYMBOL_GPL(phy_resolve_aneg_pause);

/**
 * phy_resolve_aneg_linkmode - resolve the advertisements into PHY settings
 * @phydev: The phy_device struct
 *
 * Resolve our and the link partner advertisements into their corresponding
 * speed and duplex. If full duplex was negotiated, extract the pause mode
 * from the link partner mask.
 */
void phy_resolve_aneg_linkmode(struct phy_device *phydev)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(common);
        const struct link_capabilities *c;

        linkmode_and(common, phydev->lp_advertising, phydev->advertising);

        c = phy_caps_lookup_by_linkmode(common);
        if (c) {
                phydev->speed = c->speed;
                phydev->duplex = c->duplex;
        }

        phy_resolve_aneg_pause(phydev);
}
EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);

/**
 * phy_check_downshift - check whether downshift occurred
 * @phydev: The phy_device struct
 *
 * Check whether a downshift to a lower speed occurred. If this should be the
 * case warn the user.
 * Prerequisite for detecting downshift is that PHY driver implements the
 * read_status callback and sets phydev->speed to the actual link speed.
 */
void phy_check_downshift(struct phy_device *phydev)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(common);
        const struct link_capabilities *c;
        int speed = SPEED_UNKNOWN;

        phydev->downshifted_rate = 0;

        if (phydev->autoneg == AUTONEG_DISABLE ||
            phydev->speed == SPEED_UNKNOWN)
                return;

        linkmode_and(common, phydev->lp_advertising, phydev->advertising);

        c = phy_caps_lookup_by_linkmode(common);
        if (c)
                speed = c->speed;

        if (speed == SPEED_UNKNOWN || phydev->speed >= speed)
                return;

        phydev_warn(phydev, "Downshift occurred from negotiated speed %s to actual speed %s, check cabling!\n",
                    phy_speed_to_str(speed), phy_speed_to_str(phydev->speed));

        phydev->downshifted_rate = 1;
}

static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(common);
        const struct link_capabilities *c;

        linkmode_and(common, phydev->lp_advertising, phydev->advertising);

        c = phy_caps_lookup_by_linkmode_rev(common, fdx_only);
        if (c)
                return c->speed;

        return SPEED_UNKNOWN;
}

int phy_speed_down_core(struct phy_device *phydev)
{
        int min_common_speed = phy_resolve_min_speed(phydev, true);

        if (min_common_speed == SPEED_UNKNOWN)
                return -EINVAL;

        phy_caps_linkmode_max_speed(min_common_speed, phydev->advertising);

        return 0;
}

static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
                             u16 regnum)
{
        /* Write the desired MMD Devad */
        __mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);

        /* Write the desired MMD register address */
        __mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);

        /* Select the Function : DATA with no post increment */
        __mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
                        devad | MII_MMD_CTRL_NOINCR);
}

int mmd_phy_read(struct mii_bus *bus, int phy_addr, bool is_c45,
                 int devad, u32 regnum)
{
        if (is_c45)
                return __mdiobus_c45_read(bus, phy_addr, devad, regnum);

        mmd_phy_indirect(bus, phy_addr, devad, regnum);
        /* Read the content of the MMD's selected register */
        return __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
}
EXPORT_SYMBOL_GPL(mmd_phy_read);

int mmd_phy_write(struct mii_bus *bus, int phy_addr, bool is_c45,
                  int devad, u32 regnum, u16 val)
{
        if (is_c45)
                return __mdiobus_c45_write(bus, phy_addr, devad, regnum, val);

        mmd_phy_indirect(bus, phy_addr, devad, regnum);
        /* Write the data into MMD's selected register */
        return __mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
}
EXPORT_SYMBOL_GPL(mmd_phy_write);

/**
 * __phy_read_mmd - Convenience function for reading a register
 * from an MMD on a given PHY.
 * @phydev: The phy_device struct
 * @devad: The MMD to read from (0..31)
 * @regnum: The register on the MMD to read (0..65535)
 *
 * Same rules as for __phy_read();
 */
int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
{
        if (regnum > (u16)~0 || devad > 32)
                return -EINVAL;

        if (phydev->drv && phydev->drv->read_mmd)
                return phydev->drv->read_mmd(phydev, devad, regnum);

        return mmd_phy_read(phydev->mdio.bus, phydev->mdio.addr,
                            phydev->is_c45, devad, regnum);
}
EXPORT_SYMBOL(__phy_read_mmd);

/**
 * phy_read_mmd - Convenience function for reading a register
 * from an MMD on a given PHY.
 * @phydev: The phy_device struct
 * @devad: The MMD to read from
 * @regnum: The register on the MMD to read
 *
 * Same rules as for phy_read();
 */
int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_read_mmd(phydev, devad, regnum);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL(phy_read_mmd);

/**
 * __phy_write_mmd - Convenience function for writing a register
 * on an MMD on a given PHY.
 * @phydev: The phy_device struct
 * @devad: The MMD to read from
 * @regnum: The register on the MMD to read
 * @val: value to write to @regnum
 *
 * Same rules as for __phy_write();
 */
int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
{
        if (regnum > (u16)~0 || devad > 32)
                return -EINVAL;

        if (phydev->drv && phydev->drv->write_mmd)
                return phydev->drv->write_mmd(phydev, devad, regnum, val);

        return mmd_phy_write(phydev->mdio.bus, phydev->mdio.addr,
                             phydev->is_c45, devad, regnum, val);
}
EXPORT_SYMBOL(__phy_write_mmd);

/**
 * phy_write_mmd - Convenience function for writing a register
 * on an MMD on a given PHY.
 * @phydev: The phy_device struct
 * @devad: The MMD to read from
 * @regnum: The register on the MMD to read
 * @val: value to write to @regnum
 *
 * Same rules as for phy_write();
 */
int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_write_mmd(phydev, devad, regnum, val);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL(phy_write_mmd);

/**
 * phy_modify_changed - Function for modifying a PHY register
 * @phydev: the phy_device struct
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 *
 * Returns negative errno, 0 if there was no change, and 1 in case of change
 */
int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_modify_changed(phydev, regnum, mask, set);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_modify_changed);

/**
 * __phy_modify - Convenience function for modifying a PHY register
 * @phydev: the phy_device struct
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
{
        int ret;

        ret = __phy_modify_changed(phydev, regnum, mask, set);

        return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(__phy_modify);

/**
 * phy_modify - Convenience function for modifying a given PHY register
 * @phydev: the phy_device struct
 * @regnum: register number to write
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_modify(phydev, regnum, mask, set);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_modify);

/**
 * __phy_modify_mmd_changed - Function for modifying a register on MMD
 * @phydev: the phy_device struct
 * @devad: the MMD containing register to modify
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * Unlocked helper function which allows a MMD register to be modified as
 * new register value = (old register value & ~mask) | set
 *
 * Returns negative errno, 0 if there was no change, and 1 in case of change
 */
int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
                             u16 mask, u16 set)
{
        int new, ret;

        ret = __phy_read_mmd(phydev, devad, regnum);
        if (ret < 0)
                return ret;

        new = (ret & ~mask) | set;
        if (new == ret)
                return 0;

        ret = __phy_write_mmd(phydev, devad, regnum, new);

        return ret < 0 ? ret : 1;
}
EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);

/**
 * phy_modify_mmd_changed - Function for modifying a register on MMD
 * @phydev: the phy_device struct
 * @devad: the MMD containing register to modify
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 *
 * Returns negative errno, 0 if there was no change, and 1 in case of change
 */
int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
                           u16 mask, u16 set)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);

/**
 * __phy_modify_mmd - Convenience function for modifying a register on MMD
 * @phydev: the phy_device struct
 * @devad: the MMD containing register to modify
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
                     u16 mask, u16 set)
{
        int ret;

        ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);

        return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(__phy_modify_mmd);

/**
 * phy_modify_mmd - Convenience function for modifying a register on MMD
 * @phydev: the phy_device struct
 * @devad: the MMD containing register to modify
 * @regnum: register number to modify
 * @mask: bit mask of bits to clear
 * @set: new value of bits set in mask to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
                   u16 mask, u16 set)
{
        int ret;

        phy_lock_mdio_bus(phydev);
        ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_modify_mmd);

static int __phy_read_page(struct phy_device *phydev)
{
        if (WARN_ONCE(!phydev->drv->read_page, "read_page callback not available, PHY driver not loaded?\n"))
                return -EOPNOTSUPP;

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

static int __phy_write_page(struct phy_device *phydev, int page)
{
        if (WARN_ONCE(!phydev->drv->write_page, "write_page callback not available, PHY driver not loaded?\n"))
                return -EOPNOTSUPP;

        return phydev->drv->write_page(phydev, page);
}

/**
 * phy_save_page() - take the bus lock and save the current page
 * @phydev: a pointer to a &struct phy_device
 *
 * Take the MDIO bus lock, and return the current page number. On error,
 * returns a negative errno. phy_restore_page() must always be called
 * after this, irrespective of success or failure of this call.
 */
int phy_save_page(struct phy_device *phydev)
{
        phy_lock_mdio_bus(phydev);
        return __phy_read_page(phydev);
}
EXPORT_SYMBOL_GPL(phy_save_page);

/**
 * phy_select_page() - take the bus lock, save the current page, and set a page
 * @phydev: a pointer to a &struct phy_device
 * @page: desired page
 *
 * Take the MDIO bus lock to protect against concurrent access, save the
 * current PHY page, and set the current page.  On error, returns a
 * negative errno, otherwise returns the previous page number.
 * phy_restore_page() must always be called after this, irrespective
 * of success or failure of this call.
 */
int phy_select_page(struct phy_device *phydev, int page)
{
        int ret, oldpage;

        oldpage = ret = phy_save_page(phydev);
        if (ret < 0)
                return ret;

        if (oldpage != page) {
                ret = __phy_write_page(phydev, page);
                if (ret < 0)
                        return ret;
        }

        return oldpage;
}
EXPORT_SYMBOL_GPL(phy_select_page);

/**
 * phy_restore_page() - restore the page register and release the bus lock
 * @phydev: a pointer to a &struct phy_device
 * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
 * @ret: operation's return code
 *
 * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
 * This function propagates the earliest error code from the group of
 * operations.
 *
 * Returns:
 *   @oldpage if it was a negative value, otherwise
 *   @ret if it was a negative errno value, otherwise
 *   phy_write_page()'s negative value if it were in error, otherwise
 *   @ret.
 */
int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
{
        int r;

        if (oldpage >= 0) {
                r = __phy_write_page(phydev, oldpage);

                /* Propagate the operation return code if the page write
                 * was successful.
                 */
                if (ret >= 0 && r < 0)
                        ret = r;
        } else {
                /* Propagate the phy page selection error code */
                ret = oldpage;
        }

        phy_unlock_mdio_bus(phydev);

        return ret;
}
EXPORT_SYMBOL_GPL(phy_restore_page);

/**
 * phy_read_paged() - Convenience function for reading a paged register
 * @phydev: a pointer to a &struct phy_device
 * @page: the page for the phy
 * @regnum: register number
 *
 * Same rules as for phy_read().
 */
int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
{
        int ret = 0, oldpage;

        oldpage = phy_select_page(phydev, page);
        if (oldpage >= 0)
                ret = __phy_read(phydev, regnum);

        return phy_restore_page(phydev, oldpage, ret);
}
EXPORT_SYMBOL(phy_read_paged);

/**
 * phy_write_paged() - Convenience function for writing a paged register
 * @phydev: a pointer to a &struct phy_device
 * @page: the page for the phy
 * @regnum: register number
 * @val: value to write
 *
 * Same rules as for phy_write().
 */
int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
{
        int ret = 0, oldpage;

        oldpage = phy_select_page(phydev, page);
        if (oldpage >= 0)
                ret = __phy_write(phydev, regnum, val);

        return phy_restore_page(phydev, oldpage, ret);
}
EXPORT_SYMBOL(phy_write_paged);

/**
 * phy_modify_paged_changed() - Function for modifying a paged register
 * @phydev: a pointer to a &struct phy_device
 * @page: the page for the phy
 * @regnum: register number
 * @mask: bit mask of bits to clear
 * @set: bit mask of bits to set
 *
 * Returns negative errno, 0 if there was no change, and 1 in case of change
 */
int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
                             u16 mask, u16 set)
{
        int ret = 0, oldpage;

        oldpage = phy_select_page(phydev, page);
        if (oldpage >= 0)
                ret = __phy_modify_changed(phydev, regnum, mask, set);

        return phy_restore_page(phydev, oldpage, ret);
}
EXPORT_SYMBOL(phy_modify_paged_changed);

/**
 * phy_modify_paged() - Convenience function for modifying a paged register
 * @phydev: a pointer to a &struct phy_device
 * @page: the page for the phy
 * @regnum: register number
 * @mask: bit mask of bits to clear
 * @set: bit mask of bits to set
 *
 * Same rules as for phy_read() and phy_write().
 */
int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
                     u16 mask, u16 set)
{
        int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);

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