// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Adaptrum Anarion DWMAC glue layer
 *
 * Copyright (C) 2017, Adaptrum, Inc.
 * (Written by Alexandru Gagniuc <alex.g at adaptrum.com> for Adaptrum, Inc.)
 */

#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <linux/stmmac.h>

#include "stmmac.h"
#include "stmmac_platform.h"

#define GMAC_RESET_CONTROL_REG          0
#define GMAC_SW_CONFIG_REG              4
#define  GMAC_CONFIG_INTF_SEL_MASK      (0x7 << 0)
#define  GMAC_CONFIG_INTF_RGMII         (0x1 << 0)

struct anarion_gmac {
        void __iomem *ctl_block;
        uint32_t phy_intf_sel;
};

static uint32_t gmac_read_reg(struct anarion_gmac *gmac, uint8_t reg)
{
        return readl(gmac->ctl_block + reg);
};

static void gmac_write_reg(struct anarion_gmac *gmac, uint8_t reg, uint32_t val)
{
        writel(val, gmac->ctl_block + reg);
}

static int anarion_gmac_init(struct device *dev, void *priv)
{
        uint32_t sw_config;
        struct anarion_gmac *gmac = priv;

        /* Reset logic, configure interface mode, then release reset. SIMPLE! */
        gmac_write_reg(gmac, GMAC_RESET_CONTROL_REG, 1);

        sw_config = gmac_read_reg(gmac, GMAC_SW_CONFIG_REG);
        sw_config &= ~GMAC_CONFIG_INTF_SEL_MASK;
        sw_config |= (gmac->phy_intf_sel & GMAC_CONFIG_INTF_SEL_MASK);
        gmac_write_reg(gmac, GMAC_SW_CONFIG_REG, sw_config);

        gmac_write_reg(gmac, GMAC_RESET_CONTROL_REG, 0);

        return 0;
}

static void anarion_gmac_exit(struct device *dev, void *priv)
{
        struct anarion_gmac *gmac = priv;

        gmac_write_reg(gmac, GMAC_RESET_CONTROL_REG, 1);
}

static struct anarion_gmac *
anarion_config_dt(struct platform_device *pdev,
                  struct plat_stmmacenet_data *plat_dat)
{
        struct anarion_gmac *gmac;
        void __iomem *ctl_block;

        ctl_block = devm_platform_ioremap_resource(pdev, 1);
        if (IS_ERR(ctl_block)) {
                dev_err(&pdev->dev, "Cannot get reset region (%pe)!\n",
                        ctl_block);
                return ERR_CAST(ctl_block);
        }

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

        gmac->ctl_block = ctl_block;

        if (phy_interface_mode_is_rgmii(plat_dat->phy_interface)) {
                gmac->phy_intf_sel = GMAC_CONFIG_INTF_RGMII;
        } else {
                dev_err(&pdev->dev, "Unsupported phy-mode (%s)\n",
                        phy_modes(plat_dat->phy_interface));
                return ERR_PTR(-ENOTSUPP);
        }

        return gmac;
}

static int anarion_dwmac_probe(struct platform_device *pdev)
{
        int ret;
        struct anarion_gmac *gmac;
        struct plat_stmmacenet_data *plat_dat;
        struct stmmac_resources stmmac_res;

        ret = stmmac_get_platform_resources(pdev, &stmmac_res);
        if (ret)
                return ret;

        plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
        if (IS_ERR(plat_dat))
                return PTR_ERR(plat_dat);

        gmac = anarion_config_dt(pdev, plat_dat);
        if (IS_ERR(gmac))
                return PTR_ERR(gmac);

        plat_dat->init = anarion_gmac_init;
        plat_dat->exit = anarion_gmac_exit;
        plat_dat->bsp_priv = gmac;

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

static const struct of_device_id anarion_dwmac_match[] = {
        { .compatible = "adaptrum,anarion-gmac" },
        { }
};
MODULE_DEVICE_TABLE(of, anarion_dwmac_match);

static struct platform_driver anarion_dwmac_driver = {
        .probe  = anarion_dwmac_probe,
        .driver = {
                .name           = "anarion-dwmac",
                .pm             = &stmmac_pltfr_pm_ops,
                .of_match_table = anarion_dwmac_match,
        },
};
module_platform_driver(anarion_dwmac_driver);

MODULE_DESCRIPTION("Adaptrum Anarion DWMAC specific glue layer");
MODULE_AUTHOR("Alexandru Gagniuc <mr.nuke.me@gmail.com>");
MODULE_LICENSE("GPL v2");