// SPDX-License-Identifier: GPL-2.0
/*
 * Microchip KSZ8863 series register access through SMI
 *
 * Copyright (C) 2019 Pengutronix, Michael Grzeschik <kernel@pengutronix.de>
 */

#include <linux/property.h>

#include "ksz8.h"
#include "ksz_common.h"

/* Serial Management Interface (SMI) uses the following frame format:
 *
 *       preamble|start|Read/Write|  PHY   |  REG  |TA|   Data bits      | Idle
 *               |frame| OP code  |address |address|  |                  |
 * read | 32x1´s | 01  |    00    | 1xRRR  | RRRRR |Z0| 00000000DDDDDDDD |  Z
 * write| 32x1´s | 01  |    00    | 0xRRR  | RRRRR |10| xxxxxxxxDDDDDDDD |  Z
 *
 */

#define SMI_KSZ88XX_READ_PHY    BIT(4)

static int ksz8863_mdio_read(void *ctx, const void *reg_buf, size_t reg_len,
                             void *val_buf, size_t val_len)
{
        struct ksz_device *dev = ctx;
        struct mdio_device *mdev;
        u8 reg = *(u8 *)reg_buf;
        u8 *val = val_buf;
        int i, ret = 0;

        mdev = dev->priv;

        mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
        for (i = 0; i < val_len; i++) {
                int tmp = reg + i;

                ret = __mdiobus_read(mdev->bus, ((tmp & 0xE0) >> 5) |
                                     SMI_KSZ88XX_READ_PHY, tmp);
                if (ret < 0)
                        goto out;

                val[i] = ret;
        }
        ret = 0;

 out:
        mutex_unlock(&mdev->bus->mdio_lock);

        return ret;
}

static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
{
        struct ksz_device *dev = ctx;
        struct mdio_device *mdev;
        int i, ret = 0;
        u32 reg;
        u8 *val;

        mdev = dev->priv;

        val = (u8 *)(data + 4);
        reg = *(u32 *)data;

        mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
        for (i = 0; i < (count - 4); i++) {
                int tmp = reg + i;

                ret = __mdiobus_write(mdev->bus, ((tmp & 0xE0) >> 5),
                                      tmp, val[i]);
                if (ret < 0)
                        goto out;
        }

 out:
        mutex_unlock(&mdev->bus->mdio_lock);

        return ret;
}

static const struct regmap_bus regmap_smi[] = {
        {
                .read = ksz8863_mdio_read,
                .write = ksz8863_mdio_write,
        },
        {
                .read = ksz8863_mdio_read,
                .write = ksz8863_mdio_write,
                .val_format_endian_default = REGMAP_ENDIAN_BIG,
        },
        {
                .read = ksz8863_mdio_read,
                .write = ksz8863_mdio_write,
                .val_format_endian_default = REGMAP_ENDIAN_BIG,
        }
};

static const struct regmap_config ksz8863_regmap_config[] = {
        {
                .name = "#8",
                .reg_bits = 8,
                .pad_bits = 24,
                .val_bits = 8,
                .cache_type = REGCACHE_NONE,
                .lock = ksz_regmap_lock,
                .unlock = ksz_regmap_unlock,
                .max_register = U8_MAX,
        },
        {
                .name = "#16",
                .reg_bits = 8,
                .pad_bits = 24,
                .val_bits = 16,
                .cache_type = REGCACHE_NONE,
                .lock = ksz_regmap_lock,
                .unlock = ksz_regmap_unlock,
                .max_register = U8_MAX,
        },
        {
                .name = "#32",
                .reg_bits = 8,
                .pad_bits = 24,
                .val_bits = 32,
                .cache_type = REGCACHE_NONE,
                .lock = ksz_regmap_lock,
                .unlock = ksz_regmap_unlock,
                .max_register = U8_MAX,
        }
};

static int ksz8863_smi_probe(struct mdio_device *mdiodev)
{
        struct device *ddev = &mdiodev->dev;
        const struct ksz_chip_data *chip;
        struct regmap_config rc;
        struct ksz_device *dev;
        int ret;
        int i;

        chip = device_get_match_data(ddev);
        if (!chip)
                return -EINVAL;

        dev = ksz_switch_alloc(&mdiodev->dev, chip, mdiodev);
        if (!dev)
                return -ENOMEM;

        for (i = 0; i < __KSZ_NUM_REGMAPS; i++) {
                rc = ksz8863_regmap_config[i];
                rc.lock_arg = &dev->regmap_mutex;
                rc.wr_table = chip->wr_table;
                rc.rd_table = chip->rd_table;
                dev->regmap[i] = devm_regmap_init(&mdiodev->dev,
                                                  &regmap_smi[i], dev,
                                                  &rc);
                if (IS_ERR(dev->regmap[i])) {
                        return dev_err_probe(&mdiodev->dev,
                                             PTR_ERR(dev->regmap[i]),
                                             "Failed to initialize regmap%i\n",
                                             ksz8863_regmap_config[i].val_bits);
                }
        }

        if (mdiodev->dev.platform_data)
                dev->pdata = mdiodev->dev.platform_data;

        ret = ksz_switch_register(dev);

        /* Main DSA driver may not be started yet. */
        if (ret)
                return ret;

        dev_set_drvdata(&mdiodev->dev, dev);

        return 0;
}

static void ksz8863_smi_remove(struct mdio_device *mdiodev)
{
        struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);

        if (dev)
                ksz_switch_remove(dev);
}

static void ksz8863_smi_shutdown(struct mdio_device *mdiodev)
{
        struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);

        if (dev)
                dsa_switch_shutdown(dev->ds);

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

static const struct of_device_id ksz8863_dt_ids[] = {
        {
                .compatible = "microchip,ksz8863",
                .data = &ksz_switch_chips[KSZ88X3]
        },
        {
                .compatible = "microchip,ksz8873",
                .data = &ksz_switch_chips[KSZ88X3]
        },
        { },
};
MODULE_DEVICE_TABLE(of, ksz8863_dt_ids);

static struct mdio_driver ksz8863_driver = {
        .probe  = ksz8863_smi_probe,
        .remove = ksz8863_smi_remove,
        .shutdown = ksz8863_smi_shutdown,
        .mdiodrv.driver = {
                .name   = "ksz8863-switch",
                .of_match_table = ksz8863_dt_ids,
        },
};

mdio_module_driver(ksz8863_driver);

MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
MODULE_DESCRIPTION("Microchip KSZ8863 SMI Switch driver");
MODULE_LICENSE("GPL v2");