/*
 * Copyright 2012 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

/*
 * Tilera TILE-Gx USB EHCI host controller driver.
 */

#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/usb/tilegx.h>
#include <linux/usb.h>

#include <asm/homecache.h>

#include <gxio/iorpc_usb_host.h>
#include <gxio/usb_host.h>

static void tilegx_start_ehc(void)
{
}

static void tilegx_stop_ehc(void)
{
}

static int tilegx_ehci_setup(struct usb_hcd *hcd)
{
        int ret = ehci_init(hcd);

        /*
         * Some drivers do:
         *
         *   struct ehci_hcd *ehci = hcd_to_ehci(hcd);
         *   ehci->need_io_watchdog = 0;
         *
         * here, but since this is a new driver we're going to leave the
         * watchdog enabled.  Later we may try to turn it off and see
         * whether we run into any problems.
         */

        return ret;
}

static const struct hc_driver ehci_tilegx_hc_driver = {
        .description            = hcd_name,
        .product_desc           = "Tile-Gx EHCI",
        .hcd_priv_size          = sizeof(struct ehci_hcd),

        /*
         * Generic hardware linkage.
         */
        .irq                    = ehci_irq,
        .flags                  = HCD_MEMORY | HCD_USB2 | HCD_BH,

        /*
         * Basic lifecycle operations.
         */
        .reset                  = tilegx_ehci_setup,
        .start                  = ehci_run,
        .stop                   = ehci_stop,
        .shutdown               = ehci_shutdown,

        /*
         * Managing I/O requests and associated device resources.
         */
        .urb_enqueue            = ehci_urb_enqueue,
        .urb_dequeue            = ehci_urb_dequeue,
        .endpoint_disable       = ehci_endpoint_disable,
        .endpoint_reset         = ehci_endpoint_reset,

        /*
         * Scheduling support.
         */
        .get_frame_number       = ehci_get_frame,

        /*
         * Root hub support.
         */
        .hub_status_data        = ehci_hub_status_data,
        .hub_control            = ehci_hub_control,
        .bus_suspend            = ehci_bus_suspend,
        .bus_resume             = ehci_bus_resume,
        .relinquish_port        = ehci_relinquish_port,
        .port_handed_over       = ehci_port_handed_over,

        .clear_tt_buffer_complete       = ehci_clear_tt_buffer_complete,
};

static int ehci_hcd_tilegx_drv_probe(struct platform_device *pdev)
{
        struct usb_hcd *hcd;
        struct ehci_hcd *ehci;
        struct tilegx_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
        pte_t pte = { 0 };
        int my_cpu = smp_processor_id();
        int ret;

        if (usb_disabled())
                return -ENODEV;

        /*
         * Try to initialize our GXIO context; if we can't, the device
         * doesn't exist.
         */
        if (gxio_usb_host_init(&pdata->usb_ctx, pdata->dev_index, 1) != 0)
                return -ENXIO;

        hcd = usb_create_hcd(&ehci_tilegx_hc_driver, &pdev->dev,
                             dev_name(&pdev->dev));
        if (!hcd) {
          ret = -ENOMEM;
          goto err_hcd;
        }

        /*
         * We don't use rsrc_start to map in our registers, but seems like
         * we ought to set it to something, so we use the register VA.
         */
        hcd->rsrc_start =
                (ulong) gxio_usb_host_get_reg_start(&pdata->usb_ctx);
        hcd->rsrc_len = gxio_usb_host_get_reg_len(&pdata->usb_ctx);
        hcd->regs = gxio_usb_host_get_reg_start(&pdata->usb_ctx);

        tilegx_start_ehc();

        ehci = hcd_to_ehci(hcd);
        ehci->caps = hcd->regs;
        ehci->regs =
                hcd->regs + HC_LENGTH(ehci, readl(&ehci->caps->hc_capbase));
        /* cache this readonly data; minimize chip reads */
        ehci->hcs_params = readl(&ehci->caps->hcs_params);

        /* Create our IRQs and register them. */
        pdata->irq = irq_alloc_hwirq(-1);
        if (!pdata->irq) {
                ret = -ENXIO;
                goto err_no_irq;
        }

        tile_irq_activate(pdata->irq, TILE_IRQ_PERCPU);

        /* Configure interrupts. */
        ret = gxio_usb_host_cfg_interrupt(&pdata->usb_ctx,
                                          cpu_x(my_cpu), cpu_y(my_cpu),
                                          KERNEL_PL, pdata->irq);
        if (ret) {
                ret = -ENXIO;
                goto err_have_irq;
        }

        /* Register all of our memory. */
        pte = pte_set_home(pte, PAGE_HOME_HASH);
        ret = gxio_usb_host_register_client_memory(&pdata->usb_ctx, pte, 0);
        if (ret) {
                ret = -ENXIO;
                goto err_have_irq;
        }

        ret = usb_add_hcd(hcd, pdata->irq, IRQF_SHARED);
        if (ret == 0) {
                platform_set_drvdata(pdev, hcd);
                device_wakeup_enable(hcd->self.controller);
                return ret;
        }

err_have_irq:
        irq_free_hwirq(pdata->irq);
err_no_irq:
        tilegx_stop_ehc();
        usb_put_hcd(hcd);
err_hcd:
        gxio_usb_host_destroy(&pdata->usb_ctx);
        return ret;
}

static int ehci_hcd_tilegx_drv_remove(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct tilegx_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);

        usb_remove_hcd(hcd);
        usb_put_hcd(hcd);
        tilegx_stop_ehc();
        gxio_usb_host_destroy(&pdata->usb_ctx);
        irq_free_hwirq(pdata->irq);

        return 0;
}

static void ehci_hcd_tilegx_drv_shutdown(struct platform_device *pdev)
{
        usb_hcd_platform_shutdown(pdev);
        ehci_hcd_tilegx_drv_remove(pdev);
}

static struct platform_driver ehci_hcd_tilegx_driver = {
        .probe          = ehci_hcd_tilegx_drv_probe,
        .remove         = ehci_hcd_tilegx_drv_remove,
        .shutdown       = ehci_hcd_tilegx_drv_shutdown,
        .driver = {
                .name   = "tilegx-ehci",
        }
};

MODULE_ALIAS("platform:tilegx-ehci");