ehci-tilegx.c

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/*
 * 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,

    /*
     * 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 = pdev->dev.platform_data;
    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)
        return -ENOMEM;

    /*
     * 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 = create_irq();
    if (pdata->irq < 0) {
        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);
        return ret;
    }

err_have_irq:
    destroy_irq(pdata->irq);
err_no_irq:
    tilegx_stop_ehc();
    usb_put_hcd(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 = pdev->dev.platform_data;

    usb_remove_hcd(hcd);
    usb_put_hcd(hcd);
    tilegx_stop_ehc();
    gxio_usb_host_destroy(&pdata->usb_ctx);
    destroy_irq(pdata->irq);
    platform_set_drvdata(pdev, NULL);

    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",
        .owner  = THIS_MODULE,
    }
};

MODULE_ALIAS("platform:tilegx-ehci");