// SPDX-License-Identifier: GPL-2.0
/*
 * Generic platform ehci driver
 *
 * Copyright 2007 Steven Brown <sbrown@cortland.com>
 * Copyright 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
 * Copyright 2014 Hans de Goede <hdegoede@redhat.com>
 *
 * Derived from the ohci-ssb driver
 * Copyright 2007 Michael Buesch <m@bues.ch>
 *
 * Derived from the EHCI-PCI driver
 * Copyright (c) 2000-2004 by David Brownell
 *
 * Derived from the ohci-pci driver
 * Copyright 1999 Roman Weissgaerber
 * Copyright 2000-2002 David Brownell
 * Copyright 1999 Linus Torvalds
 * Copyright 1999 Gregory P. Smith
 */
#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/sys_soc.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/ehci_pdriver.h>
#include <linux/usb/of.h>

#include "ehci.h"

#define DRIVER_DESC "EHCI generic platform driver"
#define EHCI_MAX_CLKS 4
#define hcd_to_ehci_priv(h) ((struct ehci_platform_priv *)hcd_to_ehci(h)->priv)

#define BCM_USB_FIFO_THRESHOLD  0x00800040

struct ehci_platform_priv {
        struct clk *clks[EHCI_MAX_CLKS];
        struct reset_control *rsts;
        bool reset_on_resume;
        bool quirk_poll;
        struct timer_list poll_timer;
        struct delayed_work poll_work;
};

static int ehci_platform_reset(struct usb_hcd *hcd)
{
        struct platform_device *pdev = to_platform_device(hcd->self.controller);
        struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
        struct ehci_hcd *ehci = hcd_to_ehci(hcd);
        int retval;

        ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;

        if (pdata->pre_setup) {
                retval = pdata->pre_setup(hcd);
                if (retval < 0)
                        return retval;
        }

        ehci->caps = hcd->regs + pdata->caps_offset;
        retval = ehci_setup(hcd);
        if (retval)
                return retval;

        if (pdata->no_io_watchdog)
                ehci->need_io_watchdog = 0;

        if (of_device_is_compatible(pdev->dev.of_node, "brcm,xgs-iproc-ehci"))
                ehci_writel(ehci, BCM_USB_FIFO_THRESHOLD,
                            &ehci->regs->brcm_insnreg[1]);

        return 0;
}

static int ehci_platform_power_on(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        int clk, ret;

        for (clk = 0; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++) {
                ret = clk_prepare_enable(priv->clks[clk]);
                if (ret)
                        goto err_disable_clks;
        }

        return 0;

err_disable_clks:
        while (--clk >= 0)
                clk_disable_unprepare(priv->clks[clk]);

        return ret;
}

static void ehci_platform_power_off(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        int clk;

        for (clk = EHCI_MAX_CLKS - 1; clk >= 0; clk--)
                clk_disable_unprepare(priv->clks[clk]);
}

static struct hc_driver __read_mostly ehci_platform_hc_driver;

static const struct ehci_driver_overrides platform_overrides __initconst = {
        .reset =                ehci_platform_reset,
        .extra_priv_size =      sizeof(struct ehci_platform_priv),
};

static struct usb_ehci_pdata ehci_platform_defaults = {
        .power_on =             ehci_platform_power_on,
        .power_suspend =        ehci_platform_power_off,
        .power_off =            ehci_platform_power_off,
};

/**
 * quirk_poll_check_port_status - Poll port_status if the device sticks
 * @ehci: the ehci hcd pointer
 *
 * Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to be getting
 * stuck very rarely after a full/low usb device was disconnected. To
 * detect such a situation, the controllers require a special way which poll
 * the EHCI PORTSC register.
 *
 * Return: true if the controller's port_status indicated getting stuck
 */
static bool quirk_poll_check_port_status(struct ehci_hcd *ehci)
{
        u32 port_status = ehci_readl(ehci, &ehci->regs->port_status[0]);

        if (!(port_status & PORT_OWNER) &&
             (port_status & PORT_POWER) &&
            !(port_status & PORT_CONNECT) &&
             (port_status & PORT_LS_MASK))
                return true;

        return false;
}

/**
 * quirk_poll_rebind_companion - rebind comanion device to recover
 * @ehci: the ehci hcd pointer
 *
 * Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to be getting
 * stuck very rarely after a full/low usb device was disconnected. To
 * recover from such a situation, the controllers require changing the OHCI
 * functional state.
 */
static void quirk_poll_rebind_companion(struct ehci_hcd *ehci)
{
        struct device *companion_dev;
        struct usb_hcd *hcd = ehci_to_hcd(ehci);

        companion_dev = usb_of_get_companion_dev(hcd->self.controller);
        if (!companion_dev)
                return;

        device_release_driver(companion_dev);
        if (device_attach(companion_dev) < 0)
                ehci_err(ehci, "%s: failed\n", __func__);

        put_device(companion_dev);
}

static void quirk_poll_work(struct work_struct *work)
{
        struct ehci_platform_priv *priv =
                container_of(to_delayed_work(work), struct ehci_platform_priv,
                             poll_work);
        struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd,
                                             priv);

        /* check the status twice to reduce misdetection rate */
        if (!quirk_poll_check_port_status(ehci))
                return;
        udelay(10);
        if (!quirk_poll_check_port_status(ehci))
                return;

        ehci_dbg(ehci, "%s: detected getting stuck. rebind now!\n", __func__);
        quirk_poll_rebind_companion(ehci);
}

static void quirk_poll_timer(struct timer_list *t)
{
        struct ehci_platform_priv *priv = timer_container_of(priv, t,
                                                             poll_timer);
        struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd,
                                             priv);

        if (quirk_poll_check_port_status(ehci)) {
                /*
                 * Now scheduling the work for testing the port more. Note that
                 * updating the status is possible to be delayed when
                 * reconnection. So, this uses delayed work with 5 ms delay
                 * to avoid misdetection.
                 */
                schedule_delayed_work(&priv->poll_work, msecs_to_jiffies(5));
        }

        mod_timer(&priv->poll_timer, jiffies + HZ);
}

static void quirk_poll_init(struct ehci_platform_priv *priv)
{
        INIT_DELAYED_WORK(&priv->poll_work, quirk_poll_work);
        timer_setup(&priv->poll_timer, quirk_poll_timer, 0);
        mod_timer(&priv->poll_timer, jiffies + HZ);
}

static void quirk_poll_end(struct ehci_platform_priv *priv)
{
        timer_delete_sync(&priv->poll_timer);
        cancel_delayed_work(&priv->poll_work);
}

static const struct soc_device_attribute quirk_poll_match[] = {
        { .family = "R-Car Gen3" },
        { /* sentinel*/ }
};

static int ehci_platform_probe(struct platform_device *dev)
{
        struct usb_hcd *hcd;
        struct resource *res_mem;
        struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
        const struct of_device_id *match;
        struct ehci_platform_priv *priv;
        struct ehci_hcd *ehci;
        int err, irq, clk = 0;
        bool dma_mask_64;

        if (usb_disabled())
                return -ENODEV;

        /*
         * Use reasonable defaults so platforms don't have to provide these
         * with DT probing on ARM.
         */
        if (!pdata)
                pdata = &ehci_platform_defaults;

        dma_mask_64 = pdata->dma_mask_64;
        match = of_match_device(dev->dev.driver->of_match_table, &dev->dev);
        if (match && match->data)
                dma_mask_64 = true;

        err = dma_coerce_mask_and_coherent(&dev->dev,
                dma_mask_64 ? DMA_BIT_MASK(64) : DMA_BIT_MASK(32));
        if (err) {
                dev_err(&dev->dev, "Error: DMA mask configuration failed\n");
                return err;
        }

        irq = platform_get_irq(dev, 0);
        if (irq < 0)
                return irq;

        hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
                             dev_name(&dev->dev));
        if (!hcd)
                return -ENOMEM;

        platform_set_drvdata(dev, hcd);
        dev->dev.platform_data = pdata;
        priv = hcd_to_ehci_priv(hcd);
        ehci = hcd_to_ehci(hcd);

        if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
                if (of_property_read_bool(dev->dev.of_node, "big-endian-regs"))
                        ehci->big_endian_mmio = 1;

                if (of_property_read_bool(dev->dev.of_node, "big-endian-desc"))
                        ehci->big_endian_desc = 1;

                if (of_property_read_bool(dev->dev.of_node, "big-endian"))
                        ehci->big_endian_mmio = ehci->big_endian_desc = 1;

                if (of_property_read_bool(dev->dev.of_node, "spurious-oc"))
                        ehci->spurious_oc = 1;

                if (of_property_read_bool(dev->dev.of_node,
                                          "needs-reset-on-resume"))
                        priv->reset_on_resume = true;

                if (of_property_read_bool(dev->dev.of_node,
                                          "has-transaction-translator"))
                        hcd->has_tt = 1;

                if (of_device_is_compatible(dev->dev.of_node,
                                            "aspeed,ast2500-ehci") ||
                    of_device_is_compatible(dev->dev.of_node,
                                            "aspeed,ast2600-ehci") ||
                    of_device_is_compatible(dev->dev.of_node,
                                            "aspeed,ast2700-ehci"))
                        ehci->is_aspeed = 1;

                if (soc_device_match(quirk_poll_match))
                        priv->quirk_poll = true;

                for (clk = 0; clk < EHCI_MAX_CLKS; clk++) {
                        priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
                        if (IS_ERR(priv->clks[clk])) {
                                err = PTR_ERR(priv->clks[clk]);
                                if (err == -EPROBE_DEFER)
                                        goto err_put_clks;
                                priv->clks[clk] = NULL;
                                break;
                        }
                }
        }

        priv->rsts = devm_reset_control_array_get_optional_shared(&dev->dev);
        if (IS_ERR(priv->rsts)) {
                err = PTR_ERR(priv->rsts);
                goto err_put_clks;
        }

        err = reset_control_deassert(priv->rsts);
        if (err)
                goto err_put_clks;

        if (pdata->big_endian_desc)
                ehci->big_endian_desc = 1;
        if (pdata->big_endian_mmio)
                ehci->big_endian_mmio = 1;
        if (pdata->has_tt)
                hcd->has_tt = 1;
        if (pdata->reset_on_resume)
                priv->reset_on_resume = true;
        if (pdata->spurious_oc)
                ehci->spurious_oc = 1;

#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
        if (ehci->big_endian_mmio) {
                dev_err(&dev->dev,
                        "Error: CONFIG_USB_EHCI_BIG_ENDIAN_MMIO not set\n");
                err = -EINVAL;
                goto err_reset;
        }
#endif
#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_DESC
        if (ehci->big_endian_desc) {
                dev_err(&dev->dev,
                        "Error: CONFIG_USB_EHCI_BIG_ENDIAN_DESC not set\n");
                err = -EINVAL;
                goto err_reset;
        }
#endif

        if (pdata->power_on) {
                err = pdata->power_on(dev);
                if (err < 0)
                        goto err_reset;
        }

        hcd->regs = devm_platform_get_and_ioremap_resource(dev, 0, &res_mem);
        if (IS_ERR(hcd->regs)) {
                err = PTR_ERR(hcd->regs);
                goto err_power;
        }
        hcd->rsrc_start = res_mem->start;
        hcd->rsrc_len = resource_size(res_mem);

        hcd->tpl_support = of_usb_host_tpl_support(dev->dev.of_node);

        err = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (err)
                goto err_power;

        device_wakeup_enable(hcd->self.controller);
        device_enable_async_suspend(hcd->self.controller);
        platform_set_drvdata(dev, hcd);

        if (priv->quirk_poll)
                quirk_poll_init(priv);

        return err;

err_power:
        if (pdata->power_off)
                pdata->power_off(dev);
err_reset:
        reset_control_assert(priv->rsts);
err_put_clks:
        while (--clk >= 0)
                clk_put(priv->clks[clk]);

        if (pdata == &ehci_platform_defaults)
                dev->dev.platform_data = NULL;

        usb_put_hcd(hcd);

        return err;
}

static void ehci_platform_remove(struct platform_device *dev)
{
        struct usb_hcd *hcd = platform_get_drvdata(dev);
        struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        int clk;

        if (priv->quirk_poll)
                quirk_poll_end(priv);

        usb_remove_hcd(hcd);

        if (pdata->power_off)
                pdata->power_off(dev);

        reset_control_assert(priv->rsts);

        for (clk = 0; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++)
                clk_put(priv->clks[clk]);

        usb_put_hcd(hcd);

        if (pdata == &ehci_platform_defaults)
                dev->dev.platform_data = NULL;
}

static int __maybe_unused ehci_platform_suspend(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
        struct platform_device *pdev = to_platform_device(dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        bool do_wakeup = device_may_wakeup(dev);
        int ret;

        if (priv->quirk_poll)
                quirk_poll_end(priv);

        ret = ehci_suspend(hcd, do_wakeup);
        if (ret)
                return ret;

        if (pdata->power_suspend)
                pdata->power_suspend(pdev);

        ret = reset_control_assert(priv->rsts);
        if (ret) {
                if (pdata->power_on)
                        pdata->power_on(pdev);

                ehci_resume(hcd, false);

                if (priv->quirk_poll)
                        quirk_poll_init(priv);
        }

        return ret;
}

static int __maybe_unused ehci_platform_resume(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
        struct platform_device *pdev = to_platform_device(dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        struct device *companion_dev;
        int err;

        err = reset_control_deassert(priv->rsts);
        if (err)
                return err;

        if (pdata->power_on) {
                err = pdata->power_on(pdev);
                if (err < 0) {
                        reset_control_assert(priv->rsts);
                        return err;
                }
        }

        companion_dev = usb_of_get_companion_dev(hcd->self.controller);
        if (companion_dev) {
                device_pm_wait_for_dev(hcd->self.controller, companion_dev);
                put_device(companion_dev);
        }

        ehci_resume(hcd, priv->reset_on_resume);

        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);

        if (priv->quirk_poll)
                quirk_poll_init(priv);

        return 0;
}

static const struct of_device_id vt8500_ehci_ids[] = {
        { .compatible = "via,vt8500-ehci", },
        { .compatible = "wm,prizm-ehci", },
        { .compatible = "generic-ehci", },
        { .compatible = "cavium,octeon-6335-ehci", },
        { .compatible = "aspeed,ast2700-ehci",  .data = (void *)1 },
        {}
};
MODULE_DEVICE_TABLE(of, vt8500_ehci_ids);

#ifdef CONFIG_ACPI
static const struct acpi_device_id ehci_acpi_match[] = {
        { "PNP0D20", 0 }, /* EHCI controller without debug */
        { }
};
MODULE_DEVICE_TABLE(acpi, ehci_acpi_match);
#endif

static const struct platform_device_id ehci_platform_table[] = {
        { "ehci-platform", 0 },
        { }
};
MODULE_DEVICE_TABLE(platform, ehci_platform_table);

static SIMPLE_DEV_PM_OPS(ehci_platform_pm_ops, ehci_platform_suspend,
        ehci_platform_resume);

static struct platform_driver ehci_platform_driver = {
        .id_table       = ehci_platform_table,
        .probe          = ehci_platform_probe,
        .remove         = ehci_platform_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .name   = "ehci-platform",
                .pm     = pm_ptr(&ehci_platform_pm_ops),
                .of_match_table = vt8500_ehci_ids,
                .acpi_match_table = ACPI_PTR(ehci_acpi_match),
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        }
};

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

        ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
        return platform_driver_register(&ehci_platform_driver);
}
module_init(ehci_platform_init);

static void __exit ehci_platform_cleanup(void)
{
        platform_driver_unregister(&ehci_platform_driver);
}
module_exit(ehci_platform_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Hauke Mehrtens");
MODULE_AUTHOR("Alan Stern");
MODULE_LICENSE("GPL");