// SPDX-License-Identifier: GPL-2.0
/*
 * OMAP OTG controller driver
 *
 * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
 *
 * Copyright (C) 2005-2006 Nokia Corporation
 * Copyright (C) 2004 Texas Instruments
 * Copyright (C) 2004 David Brownell
 */

#include <linux/io.h>
#include <linux/err.h>
#include <linux/extcon.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/platform_data/usb-omap1.h>

struct otg_device {
        void __iomem                    *base;
        bool                            id;
        bool                            vbus;
        struct extcon_dev               *extcon;
        struct notifier_block           vbus_nb;
        struct notifier_block           id_nb;
};

#define OMAP_OTG_CTRL           0x0c
#define OMAP_OTG_ASESSVLD       (1 << 20)
#define OMAP_OTG_BSESSEND       (1 << 19)
#define OMAP_OTG_BSESSVLD       (1 << 18)
#define OMAP_OTG_VBUSVLD        (1 << 17)
#define OMAP_OTG_ID             (1 << 16)
#define OMAP_OTG_XCEIV_OUTPUTS \
        (OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
         OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)

static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
{
        u32 l;

        l = readl(otg_dev->base + OMAP_OTG_CTRL);
        l &= ~OMAP_OTG_XCEIV_OUTPUTS;
        l |= outputs;
        writel(l, otg_dev->base + OMAP_OTG_CTRL);
}

static void omap_otg_set_mode(struct otg_device *otg_dev)
{
        if (!otg_dev->id && otg_dev->vbus)
                /* Set B-session valid. */
                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
        else if (otg_dev->vbus)
                /* Set A-session valid. */
                omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
        else if (!otg_dev->id)
                /* Set B-session end to indicate no VBUS. */
                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
}

static int omap_otg_id_notifier(struct notifier_block *nb,
                                unsigned long event, void *ptr)
{
        struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);

        otg_dev->id = event;
        omap_otg_set_mode(otg_dev);

        return NOTIFY_DONE;
}

static int omap_otg_vbus_notifier(struct notifier_block *nb,
                                  unsigned long event, void *ptr)
{
        struct otg_device *otg_dev = container_of(nb, struct otg_device,
                                                  vbus_nb);

        otg_dev->vbus = event;
        omap_otg_set_mode(otg_dev);

        return NOTIFY_DONE;
}

static int omap_otg_probe(struct platform_device *pdev)
{
        const struct omap_usb_config *config = pdev->dev.platform_data;
        struct otg_device *otg_dev;
        struct extcon_dev *extcon;
        int ret;
        u32 rev;

        if (!config || !config->extcon)
                return -ENODEV;

        extcon = extcon_get_extcon_dev(config->extcon);
        if (IS_ERR(extcon))
                return PTR_ERR(extcon);

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

        otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
        if (IS_ERR(otg_dev->base))
                return PTR_ERR(otg_dev->base);

        otg_dev->extcon = extcon;
        otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
        otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;

        ret = devm_extcon_register_notifier(&pdev->dev, extcon,
                                        EXTCON_USB_HOST, &otg_dev->id_nb);
        if (ret)
                return ret;

        ret = devm_extcon_register_notifier(&pdev->dev, extcon,
                                        EXTCON_USB, &otg_dev->vbus_nb);
        if (ret) {
                return ret;
        }

        otg_dev->id = extcon_get_state(extcon, EXTCON_USB_HOST);
        otg_dev->vbus = extcon_get_state(extcon, EXTCON_USB);
        omap_otg_set_mode(otg_dev);

        rev = readl(otg_dev->base);

        dev_info(&pdev->dev,
                 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
                 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
                 otg_dev->vbus);

        platform_set_drvdata(pdev, otg_dev);

        return 0;
}

static struct platform_driver omap_otg_driver = {
        .probe          = omap_otg_probe,
        .driver         = {
                .name   = "omap_otg",
        },
};
module_platform_driver(omap_otg_driver);

MODULE_DESCRIPTION("OMAP USB OTG controller driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");