// SPDX-License-Identifier: GPL-2.0+
/*
 * dwmac-renesas-gbeth.c - DWMAC Specific Glue layer for Renesas GBETH
 *
 * The Rx and Tx clocks are supplied as follows for the GBETH IP.
 *
 *                         Rx / Tx
 *   -------+------------- on / off -------
 *          |
 *          |            Rx-180 / Tx-180
 *          +---- not ---- on / off -------
 *
 * Copyright (C) 2025 Renesas Electronics Corporation
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pcs-rzn1-miic.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/types.h>

#include "stmmac_platform.h"

/**
 * struct renesas_gbeth_of_data - OF data for Renesas GBETH
 *
 * @clks: Array of clock names
 * @num_clks: Number of clocks
 * @stmmac_flags: Flags for the stmmac driver
 * @handle_reset: Flag to indicate if reset control is
 *                handled by the glue driver or core driver.
 * @set_clk_tx_rate: Flag to indicate if Tx clock is fixed or
 *                   set_clk_tx_rate is needed.
 * @has_pcs: Flag to indicate if the MAC has a PCS
 */
struct renesas_gbeth_of_data {
        const char * const *clks;
        u8 num_clks;
        u32 stmmac_flags;
        bool handle_reset;
        bool set_clk_tx_rate;
        bool has_pcs;
};

struct renesas_gbeth {
        const struct renesas_gbeth_of_data *of_data;
        struct plat_stmmacenet_data *plat_dat;
        struct reset_control *rstc;
        struct device *dev;
};

static const char *const renesas_gbeth_clks[] = {
        "tx", "tx-180", "rx", "rx-180",
};

static const char *const renesas_gmac_clks[] = {
        "tx",
};

static int renesas_gmac_pcs_init(struct stmmac_priv *priv)
{
        struct device_node *np = priv->device->of_node;
        struct device_node *pcs_node;
        struct phylink_pcs *pcs;

        pcs_node = of_parse_phandle(np, "pcs-handle", 0);
        if (pcs_node) {
                pcs = miic_create(priv->device, pcs_node);
                of_node_put(pcs_node);
                if (IS_ERR(pcs))
                        return PTR_ERR(pcs);

                priv->hw->phylink_pcs = pcs;
        }

        return 0;
}

static void renesas_gmac_pcs_exit(struct stmmac_priv *priv)
{
        if (priv->hw->phylink_pcs)
                miic_destroy(priv->hw->phylink_pcs);
}

static struct phylink_pcs *renesas_gmac_select_pcs(struct stmmac_priv *priv,
                                                   phy_interface_t interface)
{
        return priv->hw->phylink_pcs;
}

static int renesas_gbeth_init(struct device *dev, void *priv)
{
        struct plat_stmmacenet_data *plat_dat;
        struct renesas_gbeth *gbeth = priv;
        int ret;

        plat_dat = gbeth->plat_dat;

        ret = reset_control_deassert(gbeth->rstc);
        if (ret) {
                dev_err(gbeth->dev, "Reset deassert failed\n");
                return ret;
        }

        ret = clk_bulk_prepare_enable(plat_dat->num_clks,
                                      plat_dat->clks);
        if (ret)
                reset_control_assert(gbeth->rstc);

        return ret;
}

static void renesas_gbeth_exit(struct device *dev, void *priv)
{
        struct plat_stmmacenet_data *plat_dat;
        struct renesas_gbeth *gbeth = priv;
        int ret;

        plat_dat = gbeth->plat_dat;

        clk_bulk_disable_unprepare(plat_dat->num_clks, plat_dat->clks);

        ret = reset_control_assert(gbeth->rstc);
        if (ret)
                dev_err(gbeth->dev, "Reset assert failed\n");
}

static int renesas_gbeth_probe(struct platform_device *pdev)
{
        const struct renesas_gbeth_of_data *of_data;
        struct plat_stmmacenet_data *plat_dat;
        struct stmmac_resources stmmac_res;
        struct device *dev = &pdev->dev;
        struct renesas_gbeth *gbeth;
        unsigned int i;
        int err;

        err = stmmac_get_platform_resources(pdev, &stmmac_res);
        if (err)
                return dev_err_probe(dev, err,
                                     "failed to get resources\n");

        plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
        if (IS_ERR(plat_dat))
                return dev_err_probe(dev, PTR_ERR(plat_dat),
                                     "dt configuration failed\n");

        gbeth = devm_kzalloc(dev, sizeof(*gbeth), GFP_KERNEL);
        if (!gbeth)
                return -ENOMEM;

        of_data = of_device_get_match_data(&pdev->dev);
        gbeth->of_data = of_data;

        plat_dat->num_clks = of_data->num_clks;
        plat_dat->clks = devm_kcalloc(dev, plat_dat->num_clks,
                                      sizeof(*plat_dat->clks), GFP_KERNEL);
        if (!plat_dat->clks)
                return -ENOMEM;

        for (i = 0; i < plat_dat->num_clks; i++)
                plat_dat->clks[i].id = of_data->clks[i];

        err = devm_clk_bulk_get(dev, plat_dat->num_clks, plat_dat->clks);
        if (err < 0)
                return err;

        plat_dat->clk_tx_i = stmmac_pltfr_find_clk(plat_dat, "tx");
        if (!plat_dat->clk_tx_i)
                return dev_err_probe(dev, -EINVAL,
                                     "error finding tx clock\n");

        if (of_data->handle_reset) {
                gbeth->rstc = devm_reset_control_get_exclusive(dev, NULL);
                if (IS_ERR(gbeth->rstc))
                        return PTR_ERR(gbeth->rstc);
        }

        gbeth->dev = dev;
        gbeth->plat_dat = plat_dat;
        plat_dat->bsp_priv = gbeth;
        if (of_data->set_clk_tx_rate)
                plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;
        plat_dat->init = renesas_gbeth_init;
        plat_dat->exit = renesas_gbeth_exit;
        plat_dat->flags |= STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |
                           gbeth->of_data->stmmac_flags;
        if (of_data->has_pcs) {
                plat_dat->pcs_init = renesas_gmac_pcs_init;
                plat_dat->pcs_exit = renesas_gmac_pcs_exit;
                plat_dat->select_pcs = renesas_gmac_select_pcs;
        }

        return devm_stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
}

static const struct renesas_gbeth_of_data renesas_gbeth_of_data = {
        .clks = renesas_gbeth_clks,
        .num_clks = ARRAY_SIZE(renesas_gbeth_clks),
        .handle_reset = true,
        .set_clk_tx_rate = true,
        .stmmac_flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
                        STMMAC_FLAG_SPH_DISABLE,
};

static const struct renesas_gbeth_of_data renesas_gmac_of_data = {
        .clks = renesas_gmac_clks,
        .num_clks = ARRAY_SIZE(renesas_gmac_clks),
        .stmmac_flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY,
        .has_pcs = true,
};

static const struct of_device_id renesas_gbeth_match[] = {
        { .compatible = "renesas,r9a08g046-gbeth", .data = &renesas_gbeth_of_data },
        { .compatible = "renesas,r9a09g077-gbeth", .data = &renesas_gmac_of_data },
        { .compatible = "renesas,rzv2h-gbeth", .data = &renesas_gbeth_of_data },
        { /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, renesas_gbeth_match);

static struct platform_driver renesas_gbeth_driver = {
        .probe  = renesas_gbeth_probe,
        .driver = {
                .name           = "renesas-gbeth",
                .pm             = &stmmac_pltfr_pm_ops,
                .of_match_table = renesas_gbeth_match,
        },
};
module_platform_driver(renesas_gbeth_driver);

MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
MODULE_DESCRIPTION("Renesas GBETH DWMAC Specific Glue layer");
MODULE_LICENSE("GPL");