// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017 Pengutronix, Juergen Borleis <kernel@pengutronix.de>
 *
 * Partially based on a patch from
 * Copyright (c) 2014 Stefan Roese <sr@denx.de>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mdio.h>
#include <linux/phy.h>
#include <linux/of.h>

#include "lan9303.h"

/* Generate phy-addr and -reg from the input address */
#define PHY_ADDR(x) ((((x) >> 6) + 0x10) & 0x1f)
#define PHY_REG(x) (((x) >> 1) & 0x1f)

struct lan9303_mdio {
        struct mdio_device *device;
        struct lan9303 chip;
};

static void lan9303_mdio_real_write(struct mdio_device *mdio, int reg, u16 val)
{
        mdio->bus->write(mdio->bus, PHY_ADDR(reg), PHY_REG(reg), val);
}

static int lan9303_mdio_write(void *ctx, uint32_t reg, uint32_t val)
{
        struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;

        reg <<= 2; /* reg num to offset */
        mutex_lock_nested(&sw_dev->device->bus->mdio_lock, MDIO_MUTEX_NESTED);
        lan9303_mdio_real_write(sw_dev->device, reg, val & 0xffff);
        lan9303_mdio_real_write(sw_dev->device, reg + 2, (val >> 16) & 0xffff);
        mutex_unlock(&sw_dev->device->bus->mdio_lock);

        return 0;
}

static u16 lan9303_mdio_real_read(struct mdio_device *mdio, int reg)
{
        return mdio->bus->read(mdio->bus, PHY_ADDR(reg), PHY_REG(reg));
}

static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
{
        struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;

        reg <<= 2; /* reg num to offset */
        mutex_lock_nested(&sw_dev->device->bus->mdio_lock, MDIO_MUTEX_NESTED);
        *val = lan9303_mdio_real_read(sw_dev->device, reg);
        *val |= (lan9303_mdio_real_read(sw_dev->device, reg + 2) << 16);
        mutex_unlock(&sw_dev->device->bus->mdio_lock);

        return 0;
}

static int lan9303_mdio_phy_write(struct lan9303 *chip, int addr, int reg,
                                  u16 val)
{
        struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);

        return mdiobus_write_nested(sw_dev->device->bus, addr, reg, val);
}

static int lan9303_mdio_phy_read(struct lan9303 *chip, int addr, int reg)
{
        struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);

        return mdiobus_read_nested(sw_dev->device->bus, addr, reg);
}

static const struct lan9303_phy_ops lan9303_mdio_phy_ops = {
        .phy_read = lan9303_mdio_phy_read,
        .phy_write = lan9303_mdio_phy_write,
};

static const struct regmap_config lan9303_mdio_regmap_config = {
        .reg_bits = 8,
        .val_bits = 32,
        .reg_stride = 1,
        .can_multi_write = true,
        .max_register = 0x0ff, /* address bits 0..1 are not used */
        .reg_format_endian = REGMAP_ENDIAN_LITTLE,

        .volatile_table = &lan9303_register_set,
        .wr_table = &lan9303_register_set,
        .rd_table = &lan9303_register_set,

        .reg_read = lan9303_mdio_read,
        .reg_write = lan9303_mdio_write,

        .cache_type = REGCACHE_NONE,
};

static int lan9303_mdio_probe(struct mdio_device *mdiodev)
{
        struct lan9303_mdio *sw_dev;
        int ret;

        sw_dev = devm_kzalloc(&mdiodev->dev, sizeof(struct lan9303_mdio),
                              GFP_KERNEL);
        if (!sw_dev)
                return -ENOMEM;

        sw_dev->chip.regmap = devm_regmap_init(&mdiodev->dev, NULL, sw_dev,
                                               &lan9303_mdio_regmap_config);
        if (IS_ERR(sw_dev->chip.regmap)) {
                ret = PTR_ERR(sw_dev->chip.regmap);
                dev_err(&mdiodev->dev, "regmap init failed: %d\n", ret);
                return ret;
        }

        /* link forward and backward */
        sw_dev->device = mdiodev;
        dev_set_drvdata(&mdiodev->dev, sw_dev);
        sw_dev->chip.dev = &mdiodev->dev;

        sw_dev->chip.ops = &lan9303_mdio_phy_ops;

        ret = lan9303_probe(&sw_dev->chip, mdiodev->dev.of_node);
        if (ret != 0)
                return ret;

        dev_info(&mdiodev->dev, "LAN9303 MDIO driver loaded successfully\n");

        return 0;
}

static void lan9303_mdio_remove(struct mdio_device *mdiodev)
{
        struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);

        if (!sw_dev)
                return;

        lan9303_remove(&sw_dev->chip);
}

static void lan9303_mdio_shutdown(struct mdio_device *mdiodev)
{
        struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);

        if (!sw_dev)
                return;

        lan9303_shutdown(&sw_dev->chip);

        dev_set_drvdata(&mdiodev->dev, NULL);
}

/*-------------------------------------------------------------------------*/

static const struct of_device_id lan9303_mdio_of_match[] = {
        { .compatible = "smsc,lan9303-mdio" },
        { .compatible = "microchip,lan9354-mdio" },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, lan9303_mdio_of_match);

static struct mdio_driver lan9303_mdio_driver = {
        .mdiodrv.driver = {
                .name = "LAN9303_MDIO",
                .of_match_table = lan9303_mdio_of_match,
        },
        .probe  = lan9303_mdio_probe,
        .remove = lan9303_mdio_remove,
        .shutdown = lan9303_mdio_shutdown,
};
mdio_module_driver(lan9303_mdio_driver);

MODULE_AUTHOR("Stefan Roese <sr@denx.de>, Juergen Borleis <kernel@pengutronix.de>");
MODULE_DESCRIPTION("Driver for SMSC/Microchip LAN9303 three port ethernet switch in MDIO managed mode");
MODULE_LICENSE("GPL v2");