// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Marvell 88e6xxx Ethernet switch PHY and PPU support
 *
 * Copyright (c) 2008 Marvell Semiconductor
 *
 * Copyright (c) 2017 Andrew Lunn <andrew@lunn.ch>
 */

#include <linux/mdio.h>
#include <linux/module.h>

#include "chip.h"
#include "phy.h"

int mv88e6165_phy_read(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
                       int addr, int reg, u16 *val)
{
        return mv88e6xxx_read(chip, addr, reg, val);
}

int mv88e6165_phy_write(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
                        int addr, int reg, u16 val)
{
        return mv88e6xxx_write(chip, addr, reg, val);
}

int mv88e6xxx_phy_read(struct mv88e6xxx_chip *chip, int phy, int reg, u16 *val)
{
        int addr = phy; /* PHY devices addresses start at 0x0 */
        struct mii_bus *bus;

        bus = mv88e6xxx_default_mdio_bus(chip);
        if (!bus)
                return -EOPNOTSUPP;

        if (!chip->info->ops->phy_read)
                return -EOPNOTSUPP;

        return chip->info->ops->phy_read(chip, bus, addr, reg, val);
}

int mv88e6xxx_phy_write(struct mv88e6xxx_chip *chip, int phy, int reg, u16 val)
{
        int addr = phy; /* PHY devices addresses start at 0x0 */
        struct mii_bus *bus;

        bus = mv88e6xxx_default_mdio_bus(chip);
        if (!bus)
                return -EOPNOTSUPP;

        if (!chip->info->ops->phy_write)
                return -EOPNOTSUPP;

        return chip->info->ops->phy_write(chip, bus, addr, reg, val);
}

static int mv88e6xxx_phy_page_get(struct mv88e6xxx_chip *chip, int phy, u8 page)
{
        return mv88e6xxx_phy_write(chip, phy, MV88E6XXX_PHY_PAGE, page);
}

static void mv88e6xxx_phy_page_put(struct mv88e6xxx_chip *chip, int phy)
{
        int err;

        /* Restore PHY page Copper 0x0 for access via the registered
         * MDIO bus
         */
        err = mv88e6xxx_phy_write(chip, phy, MV88E6XXX_PHY_PAGE,
                                  MV88E6XXX_PHY_PAGE_COPPER);
        if (unlikely(err)) {
                dev_err(chip->dev,
                        "failed to restore PHY %d page Copper (%d)\n",
                        phy, err);
        }
}

int mv88e6xxx_phy_page_read(struct mv88e6xxx_chip *chip, int phy,
                            u8 page, int reg, u16 *val)
{
        int err;

        /* There is no paging for registers 22 */
        if (reg == MV88E6XXX_PHY_PAGE)
                return -EINVAL;

        err = mv88e6xxx_phy_page_get(chip, phy, page);
        if (!err) {
                err = mv88e6xxx_phy_read(chip, phy, reg, val);
                mv88e6xxx_phy_page_put(chip, phy);
        }

        return err;
}

int mv88e6xxx_phy_page_write(struct mv88e6xxx_chip *chip, int phy,
                             u8 page, int reg, u16 val)
{
        int err;

        /* There is no paging for registers 22 */
        if (reg == MV88E6XXX_PHY_PAGE)
                return -EINVAL;

        err = mv88e6xxx_phy_page_get(chip, phy, page);
        if (!err) {
                err = mv88e6xxx_phy_write(chip, phy, MV88E6XXX_PHY_PAGE, page);
                if (!err)
                        err = mv88e6xxx_phy_write(chip, phy, reg, val);

                mv88e6xxx_phy_page_put(chip, phy);
        }

        return err;
}

static int mv88e6xxx_phy_ppu_disable(struct mv88e6xxx_chip *chip)
{
        if (!chip->info->ops->ppu_disable)
                return 0;

        return chip->info->ops->ppu_disable(chip);
}

static int mv88e6xxx_phy_ppu_enable(struct mv88e6xxx_chip *chip)
{
        if (!chip->info->ops->ppu_enable)
                return 0;

        return chip->info->ops->ppu_enable(chip);
}

static void mv88e6xxx_phy_ppu_reenable_work(struct work_struct *ugly)
{
        struct mv88e6xxx_chip *chip;

        chip = container_of(ugly, struct mv88e6xxx_chip, ppu_work);

        mv88e6xxx_reg_lock(chip);

        if (mutex_trylock(&chip->ppu_mutex)) {
                if (mv88e6xxx_phy_ppu_enable(chip) == 0)
                        chip->ppu_disabled = 0;
                mutex_unlock(&chip->ppu_mutex);
        }

        mv88e6xxx_reg_unlock(chip);
}

static void mv88e6xxx_phy_ppu_reenable_timer(struct timer_list *t)
{
        struct mv88e6xxx_chip *chip = from_timer(chip, t, ppu_timer);

        schedule_work(&chip->ppu_work);
}

static int mv88e6xxx_phy_ppu_access_get(struct mv88e6xxx_chip *chip)
{
        int ret;

        mutex_lock(&chip->ppu_mutex);

        /* If the PHY polling unit is enabled, disable it so that
         * we can access the PHY registers.  If it was already
         * disabled, cancel the timer that is going to re-enable
         * it.
         */
        if (!chip->ppu_disabled) {
                ret = mv88e6xxx_phy_ppu_disable(chip);
                if (ret < 0) {
                        mutex_unlock(&chip->ppu_mutex);
                        return ret;
                }
                chip->ppu_disabled = 1;
        } else {
                del_timer(&chip->ppu_timer);
                ret = 0;
        }

        return ret;
}

static void mv88e6xxx_phy_ppu_access_put(struct mv88e6xxx_chip *chip)
{
        /* Schedule a timer to re-enable the PHY polling unit. */
        mod_timer(&chip->ppu_timer, jiffies + msecs_to_jiffies(10));
        mutex_unlock(&chip->ppu_mutex);
}

static void mv88e6xxx_phy_ppu_state_init(struct mv88e6xxx_chip *chip)
{
        mutex_init(&chip->ppu_mutex);
        INIT_WORK(&chip->ppu_work, mv88e6xxx_phy_ppu_reenable_work);
        timer_setup(&chip->ppu_timer, mv88e6xxx_phy_ppu_reenable_timer, 0);
}

static void mv88e6xxx_phy_ppu_state_destroy(struct mv88e6xxx_chip *chip)
{
        del_timer_sync(&chip->ppu_timer);
}

int mv88e6185_phy_ppu_read(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
                           int addr, int reg, u16 *val)
{
        int err;

        err = mv88e6xxx_phy_ppu_access_get(chip);
        if (!err) {
                err = mv88e6xxx_read(chip, addr, reg, val);
                mv88e6xxx_phy_ppu_access_put(chip);
        }

        return err;
}

int mv88e6185_phy_ppu_write(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
                            int addr, int reg, u16 val)
{
        int err;

        err = mv88e6xxx_phy_ppu_access_get(chip);
        if (!err) {
                err = mv88e6xxx_write(chip, addr, reg, val);
                mv88e6xxx_phy_ppu_access_put(chip);
        }

        return err;
}

void mv88e6xxx_phy_init(struct mv88e6xxx_chip *chip)
{
        if (chip->info->ops->ppu_enable && chip->info->ops->ppu_disable)
                mv88e6xxx_phy_ppu_state_init(chip);
}

void mv88e6xxx_phy_destroy(struct mv88e6xxx_chip *chip)
{
        if (chip->info->ops->ppu_enable && chip->info->ops->ppu_disable)
                mv88e6xxx_phy_ppu_state_destroy(chip);
}

int mv88e6xxx_phy_setup(struct mv88e6xxx_chip *chip)
{
        return mv88e6xxx_phy_ppu_enable(chip);
}