// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Marvell 88E6352 family SERDES PCS support
 *
 * Copyright (c) 2008 Marvell Semiconductor
 *
 * Copyright (c) 2017 Andrew Lunn <andrew@lunn.ch>
 */
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/mii.h>
#include <linux/string_choices.h>

#include "chip.h"
#include "global2.h"
#include "phy.h"
#include "port.h"
#include "serdes.h"

struct mv88e639x_pcs {
        struct mdio_device mdio;
        struct phylink_pcs sgmii_pcs;
        struct phylink_pcs xg_pcs;
        bool erratum_3_14;
        bool supports_5g;
        phy_interface_t interface;
        unsigned int irq;
        char name[64];
        irqreturn_t (*handle_irq)(struct mv88e639x_pcs *mpcs);
};

static int mv88e639x_read(struct mv88e639x_pcs *mpcs, u16 regnum, u16 *val)
{
        int err;

        err = mdiodev_c45_read(&mpcs->mdio, MDIO_MMD_PHYXS, regnum);
        if (err < 0)
                return err;

        *val = err;

        return 0;
}

static int mv88e639x_write(struct mv88e639x_pcs *mpcs, u16 regnum, u16 val)
{
        return mdiodev_c45_write(&mpcs->mdio, MDIO_MMD_PHYXS, regnum, val);
}

static int mv88e639x_modify(struct mv88e639x_pcs *mpcs, u16 regnum, u16 mask,
                            u16 val)
{
        return mdiodev_c45_modify(&mpcs->mdio, MDIO_MMD_PHYXS, regnum, mask,
                                  val);
}

static int mv88e639x_modify_changed(struct mv88e639x_pcs *mpcs, u16 regnum,
                                    u16 mask, u16 set)
{
        return mdiodev_c45_modify_changed(&mpcs->mdio, MDIO_MMD_PHYXS, regnum,
                                          mask, set);
}

static struct mv88e639x_pcs *
mv88e639x_pcs_alloc(struct device *dev, struct mii_bus *bus, unsigned int addr,
                    int port)
{
        struct mv88e639x_pcs *mpcs;

        mpcs = kzalloc_obj(*mpcs);
        if (!mpcs)
                return NULL;

        mpcs->mdio.dev.parent = dev;
        mpcs->mdio.bus = bus;
        mpcs->mdio.addr = addr;

        snprintf(mpcs->name, sizeof(mpcs->name),
                 "mv88e6xxx-%s-serdes-%d", dev_name(dev), port);

        return mpcs;
}

static irqreturn_t mv88e639x_pcs_handle_irq(int irq, void *dev_id)
{
        struct mv88e639x_pcs *mpcs = dev_id;
        irqreturn_t (*handler)(struct mv88e639x_pcs *);

        handler = READ_ONCE(mpcs->handle_irq);
        if (!handler)
                return IRQ_NONE;

        return handler(mpcs);
}

static int mv88e639x_pcs_setup_irq(struct mv88e639x_pcs *mpcs,
                                   struct mv88e6xxx_chip *chip, int port)
{
        unsigned int irq;

        irq = mv88e6xxx_serdes_irq_mapping(chip, port);
        if (!irq) {
                /* Use polling mode */
                mpcs->sgmii_pcs.poll = true;
                mpcs->xg_pcs.poll = true;
                return 0;
        }

        mpcs->irq = irq;

        return request_threaded_irq(irq, NULL, mv88e639x_pcs_handle_irq,
                                    IRQF_ONESHOT, mpcs->name, mpcs);
}

static void mv88e639x_pcs_teardown(struct mv88e6xxx_chip *chip, int port)
{
        struct mv88e639x_pcs *mpcs = chip->ports[port].pcs_private;

        if (!mpcs)
                return;

        if (mpcs->irq)
                free_irq(mpcs->irq, mpcs);

        kfree(mpcs);

        chip->ports[port].pcs_private = NULL;
}

static struct mv88e639x_pcs *sgmii_pcs_to_mv88e639x_pcs(struct phylink_pcs *pcs)
{
        return container_of(pcs, struct mv88e639x_pcs, sgmii_pcs);
}

static irqreturn_t mv88e639x_sgmii_handle_irq(struct mv88e639x_pcs *mpcs)
{
        u16 int_status;
        int err;

        err = mv88e639x_read(mpcs, MV88E6390_SGMII_INT_STATUS, &int_status);
        if (err)
                return IRQ_NONE;

        if (int_status & (MV88E6390_SGMII_INT_LINK_DOWN |
                          MV88E6390_SGMII_INT_LINK_UP)) {
                phylink_pcs_change(&mpcs->sgmii_pcs,
                                   int_status & MV88E6390_SGMII_INT_LINK_UP);

                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}

static int mv88e639x_sgmii_pcs_control_irq(struct mv88e639x_pcs *mpcs,
                                           bool enable)
{
        u16 val = 0;

        if (enable)
                val |= MV88E6390_SGMII_INT_LINK_DOWN |
                       MV88E6390_SGMII_INT_LINK_UP;

        return mv88e639x_modify(mpcs, MV88E6390_SGMII_INT_ENABLE,
                                MV88E6390_SGMII_INT_LINK_DOWN |
                                MV88E6390_SGMII_INT_LINK_UP, val);
}

static int mv88e639x_sgmii_pcs_control_pwr(struct mv88e639x_pcs *mpcs,
                                           bool enable)
{
        u16 mask, val;

        if (enable) {
                mask = BMCR_RESET | BMCR_LOOPBACK | BMCR_PDOWN;
                val = 0;
        } else {
                mask = val = BMCR_PDOWN;
        }

        return mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR, mask, val);
}

static int mv88e639x_sgmii_pcs_enable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        /* power enable done in post_config */
        mpcs->handle_irq = mv88e639x_sgmii_handle_irq;

        return mv88e639x_sgmii_pcs_control_irq(mpcs, !!mpcs->irq);
}

static void mv88e639x_sgmii_pcs_disable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_sgmii_pcs_control_irq(mpcs, false);
        mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
}

static void mv88e639x_sgmii_pcs_pre_config(struct phylink_pcs *pcs,
                                           phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
}

static int mv88e6390_erratum_3_14(struct mv88e639x_pcs *mpcs)
{
        static const int lanes[] = { MV88E6390_PORT9_LANE0, MV88E6390_PORT9_LANE1,
                MV88E6390_PORT9_LANE2, MV88E6390_PORT9_LANE3,
                MV88E6390_PORT10_LANE0, MV88E6390_PORT10_LANE1,
                MV88E6390_PORT10_LANE2, MV88E6390_PORT10_LANE3 };
        int err, i;

        /* 88e6190x and 88e6390x errata 3.14:
         * After chip reset, SERDES reconfiguration or SERDES core
         * Software Reset, the SERDES lanes may not be properly aligned
         * resulting in CRC errors
         */

        for (i = 0; i < ARRAY_SIZE(lanes); i++) {
                err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
                                        MDIO_MMD_PHYXS,
                                        0xf054, 0x400C);
                if (err)
                        return err;

                err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
                                        MDIO_MMD_PHYXS,
                                        0xf054, 0x4000);
                if (err)
                        return err;
        }

        return 0;
}

static int mv88e639x_sgmii_pcs_post_config(struct phylink_pcs *pcs,
                                           phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
        int err;

        mv88e639x_sgmii_pcs_control_pwr(mpcs, true);

        if (mpcs->erratum_3_14) {
                err = mv88e6390_erratum_3_14(mpcs);
                if (err)
                        dev_err(mpcs->mdio.dev.parent,
                                "failed to apply erratum 3.14: %pe\n",
                                ERR_PTR(err));
        }

        return 0;
}

static void mv88e639x_sgmii_pcs_get_state(struct phylink_pcs *pcs,
                                          unsigned int neg_mode,
                                          struct phylink_link_state *state)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
        u16 bmsr, lpa, status;
        int err;

        err = mv88e639x_read(mpcs, MV88E6390_SGMII_BMSR, &bmsr);
        if (err) {
                dev_err(mpcs->mdio.dev.parent,
                        "can't read Serdes PHY %s: %pe\n",
                        "BMSR", ERR_PTR(err));
                state->link = false;
                return;
        }

        err = mv88e639x_read(mpcs, MV88E6390_SGMII_LPA, &lpa);
        if (err) {
                dev_err(mpcs->mdio.dev.parent,
                        "can't read Serdes PHY %s: %pe\n",
                        "LPA", ERR_PTR(err));
                state->link = false;
                return;
        }

        err = mv88e639x_read(mpcs, MV88E6390_SGMII_PHY_STATUS, &status);
        if (err) {
                dev_err(mpcs->mdio.dev.parent,
                        "can't read Serdes PHY %s: %pe\n",
                        "status", ERR_PTR(err));
                state->link = false;
                return;
        }

        mv88e6xxx_pcs_decode_state(mpcs->mdio.dev.parent, bmsr, lpa, status,
                                   state);
}

static int mv88e639x_sgmii_pcs_config(struct phylink_pcs *pcs,
                                      unsigned int neg_mode,
                                      phy_interface_t interface,
                                      const unsigned long *advertising,
                                      bool permit_pause_to_mac)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
        u16 val, bmcr;
        bool changed;
        int adv, err;

        adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
        if (adv < 0)
                return 0;

        mpcs->interface = interface;

        err = mv88e639x_modify_changed(mpcs, MV88E6390_SGMII_ADVERTISE,
                                       0xffff, adv);
        if (err < 0)
                return err;

        changed = err > 0;

        err = mv88e639x_read(mpcs, MV88E6390_SGMII_BMCR, &val);
        if (err)
                return err;

        if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
                bmcr = val | BMCR_ANENABLE;
        else
                bmcr = val & ~BMCR_ANENABLE;

        /* setting ANENABLE triggers a restart of negotiation */
        if (bmcr == val)
                return changed;

        return mv88e639x_write(mpcs, MV88E6390_SGMII_BMCR, bmcr);
}

static void mv88e639x_sgmii_pcs_an_restart(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
                         BMCR_ANRESTART, BMCR_ANRESTART);
}

static void mv88e639x_sgmii_pcs_link_up(struct phylink_pcs *pcs,
                                        unsigned int mode,
                                        phy_interface_t interface,
                                        int speed, int duplex)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
        u16 bmcr;
        int err;

        if (phylink_autoneg_inband(mode))
                return;

        bmcr = mii_bmcr_encode_fixed(speed, duplex);

        err = mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
                               BMCR_SPEED1000 | BMCR_SPEED100 | BMCR_FULLDPLX,
                               bmcr);
        if (err)
                dev_err(mpcs->mdio.dev.parent,
                        "can't access Serdes PHY %s: %pe\n",
                        "BMCR", ERR_PTR(err));
}

static const struct phylink_pcs_ops mv88e639x_sgmii_pcs_ops = {
        .pcs_enable = mv88e639x_sgmii_pcs_enable,
        .pcs_disable = mv88e639x_sgmii_pcs_disable,
        .pcs_pre_config = mv88e639x_sgmii_pcs_pre_config,
        .pcs_post_config = mv88e639x_sgmii_pcs_post_config,
        .pcs_get_state = mv88e639x_sgmii_pcs_get_state,
        .pcs_an_restart = mv88e639x_sgmii_pcs_an_restart,
        .pcs_config = mv88e639x_sgmii_pcs_config,
        .pcs_link_up = mv88e639x_sgmii_pcs_link_up,
};

static struct mv88e639x_pcs *xg_pcs_to_mv88e639x_pcs(struct phylink_pcs *pcs)
{
        return container_of(pcs, struct mv88e639x_pcs, xg_pcs);
}

static int mv88e639x_xg_pcs_enable(struct mv88e639x_pcs *mpcs)
{
        return mv88e639x_modify(mpcs, MV88E6390_10G_CTRL1,
                                MDIO_CTRL1_RESET | MDIO_PCS_CTRL1_LOOPBACK |
                                MDIO_CTRL1_LPOWER, 0);
}

static void mv88e639x_xg_pcs_disable(struct mv88e639x_pcs *mpcs)
{
        mv88e639x_modify(mpcs, MV88E6390_10G_CTRL1, MDIO_CTRL1_LPOWER,
                         MDIO_CTRL1_LPOWER);
}

static void mv88e639x_xg_pcs_get_state(struct phylink_pcs *pcs,
                                       unsigned int neg_mode,
                                       struct phylink_link_state *state)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
        u16 status;
        int err;

        state->link = false;

        err = mv88e639x_read(mpcs, MV88E6390_10G_STAT1, &status);
        if (err) {
                dev_err(mpcs->mdio.dev.parent,
                        "can't read Serdes PHY %s: %pe\n",
                        "STAT1", ERR_PTR(err));
                return;
        }

        state->link = !!(status & MDIO_STAT1_LSTATUS);
        if (state->link) {
                switch (state->interface) {
                case PHY_INTERFACE_MODE_5GBASER:
                        state->speed = SPEED_5000;
                        break;

                case PHY_INTERFACE_MODE_10GBASER:
                case PHY_INTERFACE_MODE_RXAUI:
                case PHY_INTERFACE_MODE_XAUI:
                        state->speed = SPEED_10000;
                        break;

                default:
                        state->link = false;
                        return;
                }

                state->duplex = DUPLEX_FULL;
        }
}

static int mv88e639x_xg_pcs_config(struct phylink_pcs *pcs,
                                   unsigned int neg_mode,
                                   phy_interface_t interface,
                                   const unsigned long *advertising,
                                   bool permit_pause_to_mac)
{
        return 0;
}

static struct phylink_pcs *
mv88e639x_pcs_select(struct mv88e6xxx_chip *chip, int port,
                     phy_interface_t mode)
{
        struct mv88e639x_pcs *mpcs;

        mpcs = chip->ports[port].pcs_private;
        if (!mpcs)
                return NULL;

        switch (mode) {
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_1000BASEX:
        case PHY_INTERFACE_MODE_2500BASEX:
                return &mpcs->sgmii_pcs;

        case PHY_INTERFACE_MODE_5GBASER:
                if (!mpcs->supports_5g)
                        return NULL;
                fallthrough;
        case PHY_INTERFACE_MODE_10GBASER:
        case PHY_INTERFACE_MODE_XAUI:
        case PHY_INTERFACE_MODE_RXAUI:
        case PHY_INTERFACE_MODE_USXGMII:
                return &mpcs->xg_pcs;

        default:
                return NULL;
        }
}

/* Marvell 88E6390 Specific support */

static irqreturn_t mv88e6390_xg_handle_irq(struct mv88e639x_pcs *mpcs)
{
        u16 int_status;
        int err;

        err = mv88e639x_read(mpcs, MV88E6390_10G_INT_STATUS, &int_status);
        if (err)
                return IRQ_NONE;

        if (int_status & (MV88E6390_10G_INT_LINK_DOWN |
                          MV88E6390_10G_INT_LINK_UP)) {
                phylink_pcs_change(&mpcs->xg_pcs,
                                   int_status & MV88E6390_10G_INT_LINK_UP);

                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}

static int mv88e6390_xg_control_irq(struct mv88e639x_pcs *mpcs, bool enable)
{
        u16 val = 0;

        if (enable)
                val = MV88E6390_10G_INT_LINK_DOWN | MV88E6390_10G_INT_LINK_UP;

        return mv88e639x_modify(mpcs, MV88E6390_10G_INT_ENABLE,
                                MV88E6390_10G_INT_LINK_DOWN |
                                MV88E6390_10G_INT_LINK_UP, val);
}

static int mv88e6390_xg_pcs_enable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
        int err;

        err = mv88e639x_xg_pcs_enable(mpcs);
        if (err)
                return err;

        mpcs->handle_irq = mv88e6390_xg_handle_irq;

        return mv88e6390_xg_control_irq(mpcs, !!mpcs->irq);
}

static void mv88e6390_xg_pcs_disable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);

        mv88e6390_xg_control_irq(mpcs, false);
        mv88e639x_xg_pcs_disable(mpcs);
}

static const struct phylink_pcs_ops mv88e6390_xg_pcs_ops = {
        .pcs_enable = mv88e6390_xg_pcs_enable,
        .pcs_disable = mv88e6390_xg_pcs_disable,
        .pcs_get_state = mv88e639x_xg_pcs_get_state,
        .pcs_config = mv88e639x_xg_pcs_config,
};

static int mv88e6390_pcs_enable_checker(struct mv88e639x_pcs *mpcs)
{
        return mv88e639x_modify(mpcs, MV88E6390_PG_CONTROL,
                                MV88E6390_PG_CONTROL_ENABLE_PC,
                                MV88E6390_PG_CONTROL_ENABLE_PC);
}

static int mv88e6390_pcs_init(struct mv88e6xxx_chip *chip, int port)
{
        struct mv88e639x_pcs *mpcs;
        struct mii_bus *bus;
        struct device *dev;
        int lane, err;

        lane = mv88e6xxx_serdes_get_lane(chip, port);
        if (lane < 0)
                return 0;

        bus = mv88e6xxx_default_mdio_bus(chip);
        dev = chip->dev;

        mpcs = mv88e639x_pcs_alloc(dev, bus, lane, port);
        if (!mpcs)
                return -ENOMEM;

        mpcs->sgmii_pcs.ops = &mv88e639x_sgmii_pcs_ops;
        mpcs->xg_pcs.ops = &mv88e6390_xg_pcs_ops;

        if (chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6190X ||
            chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6390X)
                mpcs->erratum_3_14 = true;

        err = mv88e639x_pcs_setup_irq(mpcs, chip, port);
        if (err)
                goto err_free;

        /* 6390 and 6390x has the checker, 6393x doesn't appear to? */
        /* This is to enable gathering the statistics. Maybe this
         * should call out to a helper? Or we could do this at init time.
         */
        err = mv88e6390_pcs_enable_checker(mpcs);
        if (err)
                goto err_free;

        chip->ports[port].pcs_private = mpcs;

        return 0;

err_free:
        kfree(mpcs);
        return err;
}

const struct mv88e6xxx_pcs_ops mv88e6390_pcs_ops = {
        .pcs_init = mv88e6390_pcs_init,
        .pcs_teardown = mv88e639x_pcs_teardown,
        .pcs_select = mv88e639x_pcs_select,
};

/* Marvell 88E6393X Specific support */

static int mv88e6393x_power_lane(struct mv88e639x_pcs *mpcs, bool enable)
{
        u16 val = MV88E6393X_SERDES_CTRL1_TX_PDOWN |
                  MV88E6393X_SERDES_CTRL1_RX_PDOWN;

        return mv88e639x_modify(mpcs, MV88E6393X_SERDES_CTRL1, val,
                                enable ? 0 : val);
}

/* mv88e6393x family errata 4.6:
 * Cannot clear PwrDn bit on SERDES if device is configured CPU_MGD mode or
 * P0_mode is configured for [x]MII.
 * Workaround: Set SERDES register 4.F002 bit 5=0 and bit 15=1.
 *
 * It seems that after this workaround the SERDES is automatically powered up
 * (the bit is cleared), so power it down.
 */
static int mv88e6393x_erratum_4_6(struct mv88e639x_pcs *mpcs)
{
        int err;

        err = mv88e639x_modify(mpcs, MV88E6393X_SERDES_POC,
                               MV88E6393X_SERDES_POC_PDOWN |
                               MV88E6393X_SERDES_POC_RESET,
                               MV88E6393X_SERDES_POC_RESET);
        if (err)
                return err;

        err = mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
                               BMCR_PDOWN, BMCR_PDOWN);
        if (err)
                return err;

        err = mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
        if (err)
                return err;

        return mv88e6393x_power_lane(mpcs, false);
}

/* mv88e6393x family errata 4.8:
 * When a SERDES port is operating in 1000BASE-X or SGMII mode link may not
 * come up after hardware reset or software reset of SERDES core. Workaround
 * is to write SERDES register 4.F074.14=1 for only those modes and 0 in all
 * other modes.
 */
static int mv88e6393x_erratum_4_8(struct mv88e639x_pcs *mpcs)
{
        u16 reg, poc;
        int err;

        err = mv88e639x_read(mpcs, MV88E6393X_SERDES_POC, &poc);
        if (err)
                return err;

        poc &= MV88E6393X_SERDES_POC_PCS_MASK;
        if (poc == MV88E6393X_SERDES_POC_PCS_1000BASEX ||
            poc == MV88E6393X_SERDES_POC_PCS_SGMII_PHY ||
            poc == MV88E6393X_SERDES_POC_PCS_SGMII_MAC)
                reg = MV88E6393X_ERRATA_4_8_BIT;
        else
                reg = 0;

        return mv88e639x_modify(mpcs, MV88E6393X_ERRATA_4_8_REG,
                                MV88E6393X_ERRATA_4_8_BIT, reg);
}

/* mv88e6393x family errata 5.2:
 * For optimal signal integrity the following sequence should be applied to
 * SERDES operating in 10G mode. These registers only apply to 10G operation
 * and have no effect on other speeds.
 */
static int mv88e6393x_erratum_5_2(struct mv88e639x_pcs *mpcs)
{
        static const struct {
                u16 dev, reg, val, mask;
        } fixes[] = {
                { MDIO_MMD_VEND1, 0x8093, 0xcb5a, 0xffff },
                { MDIO_MMD_VEND1, 0x8171, 0x7088, 0xffff },
                { MDIO_MMD_VEND1, 0x80c9, 0x311a, 0xffff },
                { MDIO_MMD_VEND1, 0x80a2, 0x8000, 0xff7f },
                { MDIO_MMD_VEND1, 0x80a9, 0x0000, 0xfff0 },
                { MDIO_MMD_VEND1, 0x80a3, 0x0000, 0xf8ff },
                { MDIO_MMD_PHYXS, MV88E6393X_SERDES_POC,
                  MV88E6393X_SERDES_POC_RESET, MV88E6393X_SERDES_POC_RESET },
        };
        int err, i;

        for (i = 0; i < ARRAY_SIZE(fixes); ++i) {
                err = mdiodev_c45_modify(&mpcs->mdio, fixes[i].dev,
                                         fixes[i].reg, fixes[i].mask,
                                         fixes[i].val);
                if (err)
                        return err;
        }

        return 0;
}

/* Inband AN is broken on Amethyst in 2500base-x mode when set by standard
 * mechanism (via cmode).
 * We can get around this by configuring the PCS mode to 1000base-x and then
 * writing value 0x58 to register 1e.8000. (This must be done while SerDes
 * receiver and transmitter are disabled, which is, when this function is
 * called.)
 * It seem that when we do this configuration to 2500base-x mode (by changing
 * PCS mode to 1000base-x and frequency to 3.125 GHz from 1.25 GHz) and then
 * configure to sgmii or 1000base-x, the device thinks that it already has
 * SerDes at 1.25 GHz and does not change the 1e.8000 register, leaving SerDes
 * at 3.125 GHz.
 * To avoid this, change PCS mode back to 2500base-x when disabling SerDes from
 * 2500base-x mode.
 */
static int mv88e6393x_fix_2500basex_an(struct mv88e639x_pcs *mpcs, bool on)
{
        u16 reg;
        int err;

        if (on)
                reg = MV88E6393X_SERDES_POC_PCS_1000BASEX |
                      MV88E6393X_SERDES_POC_AN;
        else
                reg = MV88E6393X_SERDES_POC_PCS_2500BASEX;

        reg |= MV88E6393X_SERDES_POC_RESET;

        err = mv88e639x_modify(mpcs, MV88E6393X_SERDES_POC,
                               MV88E6393X_SERDES_POC_PCS_MASK |
                               MV88E6393X_SERDES_POC_AN |
                               MV88E6393X_SERDES_POC_RESET, reg);
        if (err)
                return err;

        return mdiodev_c45_write(&mpcs->mdio, MDIO_MMD_VEND1, 0x8000, 0x58);
}

static int mv88e6393x_sgmii_apply_2500basex_an(struct mv88e639x_pcs *mpcs,
                                               phy_interface_t interface,
                                               bool enable)
{
        int err;

        if (interface != PHY_INTERFACE_MODE_2500BASEX)
                return 0;

        err = mv88e6393x_fix_2500basex_an(mpcs, enable);
        if (err)
                dev_err(mpcs->mdio.dev.parent,
                        "failed to %s 2500basex fix: %pe\n",
                        str_enable_disable(enable), ERR_PTR(err));

        return err;
}

static void mv88e6393x_sgmii_pcs_disable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_sgmii_pcs_disable(pcs);
        mv88e6393x_power_lane(mpcs, false);
        mv88e6393x_sgmii_apply_2500basex_an(mpcs, mpcs->interface, false);
}

static void mv88e6393x_sgmii_pcs_pre_config(struct phylink_pcs *pcs,
                                            phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_sgmii_pcs_pre_config(pcs, interface);
        mv88e6393x_power_lane(mpcs, false);
        mv88e6393x_sgmii_apply_2500basex_an(mpcs, mpcs->interface, false);
}

static int mv88e6393x_sgmii_pcs_post_config(struct phylink_pcs *pcs,
                                            phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
        int err;

        err = mv88e6393x_erratum_4_8(mpcs);
        if (err)
                return err;

        err = mv88e6393x_sgmii_apply_2500basex_an(mpcs, interface, true);
        if (err)
                return err;

        err = mv88e6393x_power_lane(mpcs, true);
        if (err)
                return err;

        return mv88e639x_sgmii_pcs_post_config(pcs, interface);
}

static const struct phylink_pcs_ops mv88e6393x_sgmii_pcs_ops = {
        .pcs_enable = mv88e639x_sgmii_pcs_enable,
        .pcs_disable = mv88e6393x_sgmii_pcs_disable,
        .pcs_pre_config = mv88e6393x_sgmii_pcs_pre_config,
        .pcs_post_config = mv88e6393x_sgmii_pcs_post_config,
        .pcs_get_state = mv88e639x_sgmii_pcs_get_state,
        .pcs_an_restart = mv88e639x_sgmii_pcs_an_restart,
        .pcs_config = mv88e639x_sgmii_pcs_config,
        .pcs_link_up = mv88e639x_sgmii_pcs_link_up,
};

static irqreturn_t mv88e6393x_xg_handle_irq(struct mv88e639x_pcs *mpcs)
{
        u16 int_status, stat1;
        bool link_down;
        int err;

        err = mv88e639x_read(mpcs, MV88E6393X_10G_INT_STATUS, &int_status);
        if (err)
                return IRQ_NONE;

        if (int_status & MV88E6393X_10G_INT_LINK_CHANGE) {
                err = mv88e639x_read(mpcs, MV88E6390_10G_STAT1, &stat1);
                if (err)
                        return IRQ_NONE;

                link_down = !(stat1 & MDIO_STAT1_LSTATUS);

                phylink_pcs_change(&mpcs->xg_pcs, !link_down);

                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}

static int mv88e6393x_xg_control_irq(struct mv88e639x_pcs *mpcs, bool enable)
{
        u16 val = 0;

        if (enable)
                val = MV88E6393X_10G_INT_LINK_CHANGE;

        return mv88e639x_modify(mpcs, MV88E6393X_10G_INT_ENABLE,
                                MV88E6393X_10G_INT_LINK_CHANGE, val);
}

static int mv88e6393x_xg_pcs_enable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);

        mpcs->handle_irq = mv88e6393x_xg_handle_irq;

        return mv88e6393x_xg_control_irq(mpcs, !!mpcs->irq);
}

static void mv88e6393x_xg_pcs_disable(struct phylink_pcs *pcs)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);

        mv88e6393x_xg_control_irq(mpcs, false);
        mv88e639x_xg_pcs_disable(mpcs);
        mv88e6393x_power_lane(mpcs, false);
}

/* The PCS has to be powered down while CMODE is changed */
static void mv88e6393x_xg_pcs_pre_config(struct phylink_pcs *pcs,
                                         phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);

        mv88e639x_xg_pcs_disable(mpcs);
        mv88e6393x_power_lane(mpcs, false);
}

static int mv88e6393x_xg_pcs_post_config(struct phylink_pcs *pcs,
                                         phy_interface_t interface)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
        int err;

        if (interface == PHY_INTERFACE_MODE_10GBASER ||
            interface == PHY_INTERFACE_MODE_USXGMII) {
                err = mv88e6393x_erratum_5_2(mpcs);
                if (err)
                        return err;
        }

        err = mv88e6393x_power_lane(mpcs, true);
        if (err)
                return err;

        return mv88e639x_xg_pcs_enable(mpcs);
}

static void mv88e6393x_xg_pcs_get_state(struct phylink_pcs *pcs,
                                        unsigned int neg_mode,
                                        struct phylink_link_state *state)
{
        struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
        u16 status, lp_status;
        int err;

        if (state->interface != PHY_INTERFACE_MODE_USXGMII)
                return mv88e639x_xg_pcs_get_state(pcs, neg_mode, state);

        state->link = false;

        err = mv88e639x_read(mpcs, MV88E6390_USXGMII_PHY_STATUS, &status);
        err = err ? : mv88e639x_read(mpcs, MV88E6390_USXGMII_LP_STATUS, &lp_status);
        if (err) {
                dev_err(mpcs->mdio.dev.parent,
                        "can't read USXGMII status: %pe\n", ERR_PTR(err));
                return;
        }

        state->link = !!(status & MDIO_USXGMII_LINK);
        state->an_complete = state->link;
        phylink_decode_usxgmii_word(state, lp_status);
}

static const struct phylink_pcs_ops mv88e6393x_xg_pcs_ops = {
        .pcs_enable = mv88e6393x_xg_pcs_enable,
        .pcs_disable = mv88e6393x_xg_pcs_disable,
        .pcs_pre_config = mv88e6393x_xg_pcs_pre_config,
        .pcs_post_config = mv88e6393x_xg_pcs_post_config,
        .pcs_get_state = mv88e6393x_xg_pcs_get_state,
        .pcs_config = mv88e639x_xg_pcs_config,
};

static int mv88e6393x_pcs_init(struct mv88e6xxx_chip *chip, int port)
{
        struct mv88e639x_pcs *mpcs;
        struct mii_bus *bus;
        struct device *dev;
        int lane, err;

        lane = mv88e6xxx_serdes_get_lane(chip, port);
        if (lane < 0)
                return 0;

        bus = mv88e6xxx_default_mdio_bus(chip);
        dev = chip->dev;

        mpcs = mv88e639x_pcs_alloc(dev, bus, lane, port);
        if (!mpcs)
                return -ENOMEM;

        mpcs->sgmii_pcs.ops = &mv88e6393x_sgmii_pcs_ops;
        mpcs->xg_pcs.ops = &mv88e6393x_xg_pcs_ops;
        mpcs->supports_5g = true;

        err = mv88e6393x_erratum_4_6(mpcs);
        if (err)
                goto err_free;

        err = mv88e639x_pcs_setup_irq(mpcs, chip, port);
        if (err)
                goto err_free;

        chip->ports[port].pcs_private = mpcs;

        return 0;

err_free:
        kfree(mpcs);
        return err;
}

const struct mv88e6xxx_pcs_ops mv88e6393x_pcs_ops = {
        .pcs_init = mv88e6393x_pcs_init,
        .pcs_teardown = mv88e639x_pcs_teardown,
        .pcs_select = mv88e639x_pcs_select,
};