// SPDX-License-Identifier: GPL-2.0-only
/*
 * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
 *
 * Copyright (C) 2013 Linaro Limited
 * Matt Porter <mporter@linaro.org>
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>

#define OTGCTL                  (0)
#define OTGCTL_OTGSTAT2         BIT(31)
#define OTGCTL_OTGSTAT1         BIT(30)
#define OTGCTL_PRST_N_SW        BIT(11)
#define OTGCTL_HRESET_N         BIT(10)
#define OTGCTL_UTMI_LINE_STATE1 BIT(9)
#define OTGCTL_UTMI_LINE_STATE0 BIT(8)

#define P1CTL                   (8)
#define P1CTL_SOFT_RESET        BIT(1)
#define P1CTL_NON_DRIVING       BIT(0)

struct bcm_kona_usb {
        void __iomem *regs;
};

static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
{
        u32 val;

        val = readl(phy->regs + OTGCTL);
        if (on) {
                /* Configure and power PHY */
                val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
                         OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
                val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
        } else {
                val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
        }
        writel(val, phy->regs + OTGCTL);
}

static int bcm_kona_usb_phy_init(struct phy *gphy)
{
        struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
        u32 val;

        /* Soft reset PHY */
        val = readl(phy->regs + P1CTL);
        val &= ~P1CTL_NON_DRIVING;
        val |= P1CTL_SOFT_RESET;
        writel(val, phy->regs + P1CTL);
        writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
        /* Reset needs to be asserted for 2ms */
        mdelay(2);
        writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);

        return 0;
}

static int bcm_kona_usb_phy_power_on(struct phy *gphy)
{
        struct bcm_kona_usb *phy = phy_get_drvdata(gphy);

        bcm_kona_usb_phy_power(phy, 1);

        return 0;
}

static int bcm_kona_usb_phy_power_off(struct phy *gphy)
{
        struct bcm_kona_usb *phy = phy_get_drvdata(gphy);

        bcm_kona_usb_phy_power(phy, 0);

        return 0;
}

static const struct phy_ops ops = {
        .init           = bcm_kona_usb_phy_init,
        .power_on       = bcm_kona_usb_phy_power_on,
        .power_off      = bcm_kona_usb_phy_power_off,
        .owner          = THIS_MODULE,
};

static int bcm_kona_usb2_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct bcm_kona_usb *phy;
        struct phy *gphy;
        struct phy_provider *phy_provider;

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

        phy->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(phy->regs))
                return PTR_ERR(phy->regs);

        platform_set_drvdata(pdev, phy);

        gphy = devm_phy_create(dev, NULL, &ops);
        if (IS_ERR(gphy))
                return PTR_ERR(gphy);

        /* The Kona PHY supports an 8-bit wide UTMI interface */
        phy_set_bus_width(gphy, 8);

        phy_set_drvdata(gphy, phy);

        phy_provider = devm_of_phy_provider_register(dev,
                        of_phy_simple_xlate);

        return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
        { .compatible = "brcm,kona-usb2-phy" },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);

static struct platform_driver bcm_kona_usb2_driver = {
        .probe          = bcm_kona_usb2_probe,
        .driver         = {
                .name   = "bcm-kona-usb2",
                .of_match_table = bcm_kona_usb2_dt_ids,
        },
};

module_platform_driver(bcm_kona_usb2_driver);

MODULE_ALIAS("platform:bcm-kona-usb2");
MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
MODULE_LICENSE("GPL v2");