// SPDX-License-Identifier: GPL-2.0-only
/*
 * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
 *
 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* USB OTG PHY register offset and bit in CREG */
#define LPC18XX_CREG_CREG0              0x004
#define LPC18XX_CREG_CREG0_USB0PHY      BIT(5)

struct lpc18xx_usb_otg_phy {
        struct phy *phy;
        struct clk *clk;
        struct regmap *reg;
};

static int lpc18xx_usb_otg_phy_init(struct phy *phy)
{
        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
        int ret;

        /* The PHY must be clocked at 480 MHz */
        ret = clk_set_rate(lpc->clk, 480000000);
        if (ret)
                return ret;

        return clk_prepare(lpc->clk);
}

static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
{
        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);

        clk_unprepare(lpc->clk);

        return 0;
}

static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
{
        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
        int ret;

        ret = clk_enable(lpc->clk);
        if (ret)
                return ret;

        /* The bit in CREG is cleared to enable the PHY */
        ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
                                  LPC18XX_CREG_CREG0_USB0PHY, 0);
        if (ret) {
                clk_disable(lpc->clk);
                return ret;
        }

        return 0;
}

static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
{
        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
        int ret;

        ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
                                 LPC18XX_CREG_CREG0_USB0PHY,
                                 LPC18XX_CREG_CREG0_USB0PHY);
        if (ret)
                return ret;

        clk_disable(lpc->clk);

        return 0;
}

static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
        .init           = lpc18xx_usb_otg_phy_init,
        .exit           = lpc18xx_usb_otg_phy_exit,
        .power_on       = lpc18xx_usb_otg_phy_power_on,
        .power_off      = lpc18xx_usb_otg_phy_power_off,
        .owner          = THIS_MODULE,
};

static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
{
        struct phy_provider *phy_provider;
        struct lpc18xx_usb_otg_phy *lpc;

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

        lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
        if (IS_ERR(lpc->reg)) {
                dev_err(&pdev->dev, "failed to get syscon\n");
                return PTR_ERR(lpc->reg);
        }

        lpc->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(lpc->clk)) {
                dev_err(&pdev->dev, "failed to get clock\n");
                return PTR_ERR(lpc->clk);
        }

        lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
        if (IS_ERR(lpc->phy)) {
                dev_err(&pdev->dev, "failed to create PHY\n");
                return PTR_ERR(lpc->phy);
        }

        phy_set_drvdata(lpc->phy, lpc);

        phy_provider = devm_of_phy_provider_register(&pdev->dev,
                                                     of_phy_simple_xlate);

        return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
        { .compatible = "nxp,lpc1850-usb-otg-phy" },
        { }
};
MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);

static struct platform_driver lpc18xx_usb_otg_phy_driver = {
        .probe          = lpc18xx_usb_otg_phy_probe,
        .driver         = {
                .name   = "lpc18xx-usb-otg-phy",
                .of_match_table = lpc18xx_usb_otg_phy_match,
        },
};
module_platform_driver(lpc18xx_usb_otg_phy_driver);

MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
MODULE_LICENSE("GPL v2");