// SPDX-License-Identifier: GPL-2.0
/*
 * Nuvoton NPCM7xx driver for EHCI HCD
 *
 * Copyright (C) 2018 Nuvoton Technologies,
 * Avi Fishman <avi.fishman@nuvoton.com> <avifishman70@gmail.com>
 * Tomer Maimon <tomer.maimon@nuvoton.com> <tmaimon77@gmail.com>
 *
 * Based on various ehci-spear.c driver
 */


#include <linux/dma-mapping.h>

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "ehci.h"

#include <linux/regmap.h>
#include <linux/mfd/syscon.h>

#define DRIVER_DESC "EHCI npcm7xx driver"

static const char hcd_name[] = "npcm7xx-ehci";

#define  USB2PHYCTL_OFFSET 0x144

#define  IPSRST2_OFFSET 0x24
#define  IPSRST3_OFFSET 0x34


static struct hc_driver __read_mostly ehci_npcm7xx_hc_driver;

#ifdef CONFIG_PM_SLEEP
static int ehci_npcm7xx_drv_suspend(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        bool do_wakeup = device_may_wakeup(dev);

        return ehci_suspend(hcd, do_wakeup);
}

static int ehci_npcm7xx_drv_resume(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);

        ehci_resume(hcd, false);
        return 0;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(ehci_npcm7xx_pm_ops, ehci_npcm7xx_drv_suspend,
                ehci_npcm7xx_drv_resume);

static int npcm7xx_ehci_hcd_drv_probe(struct platform_device *pdev)
{
        struct usb_hcd *hcd;
        struct resource *res;
        struct regmap *gcr_regmap;
        struct regmap *rst_regmap;
        const struct hc_driver *driver = &ehci_npcm7xx_hc_driver;
        int irq;
        int retval;

        dev_dbg(&pdev->dev,     "initializing npcm7xx ehci USB Controller\n");

        gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
        if (IS_ERR(gcr_regmap)) {
                dev_err(&pdev->dev, "%s: failed to find nuvoton,npcm750-gcr\n",
                        __func__);
                return PTR_ERR(gcr_regmap);
        }

        rst_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-rst");
        if (IS_ERR(rst_regmap)) {
                dev_err(&pdev->dev, "%s: failed to find nuvoton,npcm750-rst\n",
                        __func__);
                return PTR_ERR(rst_regmap);
        }

        /********* phy init  ******/
        // reset usb host
        regmap_update_bits(rst_regmap, IPSRST2_OFFSET,
                        (0x1 << 26), (0x1 << 26));
        regmap_update_bits(rst_regmap, IPSRST3_OFFSET,
                        (0x1 << 25), (0x1 << 25));
        regmap_update_bits(gcr_regmap, USB2PHYCTL_OFFSET,
                        (0x1 << 28), 0);

        udelay(1);

        // enable phy
        regmap_update_bits(rst_regmap, IPSRST3_OFFSET,
                        (0x1 << 25), 0);

        udelay(50); // enable phy

        regmap_update_bits(gcr_regmap, USB2PHYCTL_OFFSET,
                        (0x1 << 28), (0x1 << 28));

        // enable host
        regmap_update_bits(rst_regmap, IPSRST2_OFFSET,
                        (0x1 << 26), 0);

        if (usb_disabled())
                return -ENODEV;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                retval = irq;
                goto fail;
        }

        /*
         * Right now device-tree probed devices don't get dma_mask set.
         * Since shared usb code relies on it, set it here for now.
         * Once we have dma capability bindings this can go away.
         */
        retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        if (retval)
                goto fail;

        hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
        if (!hcd) {
                retval = -ENOMEM;
                goto fail;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        hcd->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(hcd->regs)) {
                retval = PTR_ERR(hcd->regs);
                goto err_put_hcd;
        }
        hcd->rsrc_start = res->start;
        hcd->rsrc_len = resource_size(res);

        /* registers start at offset 0x0 */
        hcd_to_ehci(hcd)->caps = hcd->regs;

        retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (retval)
                goto err_put_hcd;

        device_wakeup_enable(hcd->self.controller);
        return retval;

err_put_hcd:
        usb_put_hcd(hcd);
fail:
        dev_err(&pdev->dev, "init fail, %d\n", retval);

        return retval;
}

static int npcm7xx_ehci_hcd_drv_remove(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);

        usb_remove_hcd(hcd);

        usb_put_hcd(hcd);

        return 0;
}

static const struct of_device_id npcm7xx_ehci_id_table[] = {
        { .compatible = "nuvoton,npcm750-ehci" },
        { },
};
MODULE_DEVICE_TABLE(of, npcm7xx_ehci_id_table);

static struct platform_driver npcm7xx_ehci_hcd_driver = {
        .probe          = npcm7xx_ehci_hcd_drv_probe,
        .remove         = npcm7xx_ehci_hcd_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .name = "npcm7xx-ehci",
                .bus = &platform_bus_type,
                .pm = &ehci_npcm7xx_pm_ops,
                .of_match_table = npcm7xx_ehci_id_table,
        }
};

static int __init ehci_npcm7xx_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        pr_info("%s: " DRIVER_DESC "\n", hcd_name);

        ehci_init_driver(&ehci_npcm7xx_hc_driver, NULL);
        return platform_driver_register(&npcm7xx_ehci_hcd_driver);
}
module_init(ehci_npcm7xx_init);

static void __exit ehci_npcm7xx_cleanup(void)
{
        platform_driver_unregister(&npcm7xx_ehci_hcd_driver);
}
module_exit(ehci_npcm7xx_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_ALIAS("platform:npcm7xx-ehci");
MODULE_AUTHOR("Avi Fishman");
MODULE_LICENSE("GPL v2");