// SPDX-License-Identifier: GPL-2.0+
/*
 * StarFive DWMAC platform driver
 *
 * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
 * Copyright (C) 2022 StarFive Technology Co., Ltd.
 *
 */

#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#include "stmmac_platform.h"

#define STARFIVE_DWMAC_PHY_INFT_FIELD           0x7U

#define JH7100_SYSMAIN_REGISTER49_DLYCHAIN      0xc8

struct starfive_dwmac_data {
        unsigned int gtxclk_dlychain;
};

struct starfive_dwmac {
        struct device *dev;
        const struct starfive_dwmac_data *data;
};

static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
{
        struct starfive_dwmac *dwmac = plat_dat->bsp_priv;
        struct regmap *regmap;
        unsigned int args[2];
        int phy_intf_sel;
        int err;

        phy_intf_sel = stmmac_get_phy_intf_sel(plat_dat->phy_interface);
        if (phy_intf_sel != PHY_INTF_SEL_RGMII &&
            phy_intf_sel != PHY_INTF_SEL_RMII) {
                dev_err(dwmac->dev, "unsupported interface %s\n",
                        phy_modes(plat_dat->phy_interface));
                return phy_intf_sel < 0 ? phy_intf_sel : -EINVAL;
        }

        regmap = syscon_regmap_lookup_by_phandle_args(dwmac->dev->of_node,
                                                      "starfive,syscon",
                                                      2, args);
        if (IS_ERR(regmap))
                return dev_err_probe(dwmac->dev, PTR_ERR(regmap), "getting the regmap failed\n");

        /* args[0]:offset  args[1]: shift */
        err = regmap_update_bits(regmap, args[0],
                                 STARFIVE_DWMAC_PHY_INFT_FIELD << args[1],
                                 phy_intf_sel << args[1]);
        if (err)
                return dev_err_probe(dwmac->dev, err, "error setting phy mode\n");

        if (dwmac->data) {
                err = regmap_write(regmap, JH7100_SYSMAIN_REGISTER49_DLYCHAIN,
                                   dwmac->data->gtxclk_dlychain);
                if (err)
                        return dev_err_probe(dwmac->dev, err,
                                             "error selecting gtxclk delay chain\n");
        }

        return 0;
}

static int starfive_dwmac_probe(struct platform_device *pdev)
{
        struct plat_stmmacenet_data *plat_dat;
        struct stmmac_resources stmmac_res;
        struct starfive_dwmac *dwmac;
        struct clk *clk_gtx;
        int err;

        err = stmmac_get_platform_resources(pdev, &stmmac_res);
        if (err)
                return dev_err_probe(&pdev->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(&pdev->dev, PTR_ERR(plat_dat),
                                     "dt configuration failed\n");

        dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
        if (!dwmac)
                return -ENOMEM;

        dwmac->data = device_get_match_data(&pdev->dev);

        plat_dat->clk_tx_i = devm_clk_get_enabled(&pdev->dev, "tx");
        if (IS_ERR(plat_dat->clk_tx_i))
                return dev_err_probe(&pdev->dev, PTR_ERR(plat_dat->clk_tx_i),
                                     "error getting tx clock\n");

        clk_gtx = devm_clk_get_enabled(&pdev->dev, "gtx");
        if (IS_ERR(clk_gtx))
                return dev_err_probe(&pdev->dev, PTR_ERR(clk_gtx),
                                     "error getting gtx clock\n");

        /* Generally, the rgmii_tx clock is provided by the internal clock,
         * which needs to match the corresponding clock frequency according
         * to different speeds. If the rgmii_tx clock is provided by the
         * external rgmii_rxin, there is no need to configure the clock
         * internally, because rgmii_rxin will be adaptively adjusted.
         */
        if (!device_property_read_bool(&pdev->dev, "starfive,tx-use-rgmii-clk"))
                plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;

        dwmac->dev = &pdev->dev;
        plat_dat->flags |= STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP;
        plat_dat->bsp_priv = dwmac;
        plat_dat->dma_cfg->dche = true;

        err = starfive_dwmac_set_mode(plat_dat);
        if (err)
                return err;

        return stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
}

static const struct starfive_dwmac_data jh7100_data = {
        .gtxclk_dlychain = 4,
};

static const struct of_device_id starfive_dwmac_match[] = {
        { .compatible = "starfive,jh7100-dwmac", .data = &jh7100_data },
        { .compatible = "starfive,jh7110-dwmac" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, starfive_dwmac_match);

static struct platform_driver starfive_dwmac_driver = {
        .probe  = starfive_dwmac_probe,
        .remove = stmmac_pltfr_remove,
        .driver = {
                .name = "starfive-dwmac",
                .pm = &stmmac_pltfr_pm_ops,
                .of_match_table = starfive_dwmac_match,
        },
};
module_platform_driver(starfive_dwmac_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("StarFive DWMAC platform driver");
MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");
MODULE_AUTHOR("Samin Guo <samin.guo@starfivetech.com>");