ehci-spear.c

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/*
* Driver for EHCI HCD on SPEAR SOC
*
* Copyright (C) 2010 ST Micro Electronics,
* Deepak Sikri <[email protected]>
*
* Based on various ehci-*.c drivers
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*/

#include <linux/clk.h>
#include <linux/jiffies.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>

struct spear_ehci {
    struct ehci_hcd ehci;
    struct clk *clk;
};

#define to_spear_ehci(hcd)  (struct spear_ehci *)hcd_to_ehci(hcd)

static void spear_start_ehci(struct spear_ehci *ehci)
{
    clk_prepare_enable(ehci->clk);
}

static void spear_stop_ehci(struct spear_ehci *ehci)
{
    clk_disable_unprepare(ehci->clk);
}

static int ehci_spear_setup(struct usb_hcd *hcd)
{
    struct ehci_hcd *ehci = hcd_to_ehci(hcd);
    int retval = 0;

    /* registers start at offset 0x0 */
    ehci->caps = hcd->regs;

    retval = ehci_setup(hcd);
    if (retval)
        return retval;

    ehci_port_power(ehci, 0);

    return retval;
}

static const struct hc_driver ehci_spear_hc_driver = {
    .description            = hcd_name,
    .product_desc           = "SPEAr EHCI",
    .hcd_priv_size          = sizeof(struct spear_ehci),

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

    /* basic lifecycle operations */
    .reset              = ehci_spear_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,
};

#ifdef CONFIG_PM
static int ehci_spear_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_spear_drv_resume(struct device *dev)
{
    struct usb_hcd *hcd = dev_get_drvdata(dev);

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

static SIMPLE_DEV_PM_OPS(ehci_spear_pm_ops, ehci_spear_drv_suspend,
        ehci_spear_drv_resume);

static u64 spear_ehci_dma_mask = DMA_BIT_MASK(32);

static int spear_ehci_hcd_drv_probe(struct platform_device *pdev)
{
    struct usb_hcd *hcd ;
    struct spear_ehci *ehci;
    struct resource *res;
    struct clk *usbh_clk;
    const struct hc_driver *driver = &ehci_spear_hc_driver;
    int irq, retval;
    char clk_name[20] = "usbh_clk";
    static int instance = -1;

    if (usb_disabled())
        return -ENODEV;

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

    /*
     * 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.
     */
    if (!pdev->dev.dma_mask)
        pdev->dev.dma_mask = &spear_ehci_dma_mask;

    /*
     * Increment the device instance, when probing via device-tree
     */
    if (pdev->id < 0)
        instance++;
    else
        instance = pdev->id;
    sprintf(clk_name, "usbh.%01d_clk", instance);

    usbh_clk = clk_get(NULL, clk_name);
    if (IS_ERR(usbh_clk)) {
        dev_err(&pdev->dev, "Error getting interface clock\n");
        retval = PTR_ERR(usbh_clk);
        goto fail_get_usbh_clk;
    }

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

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        retval = -ENODEV;
        goto fail_request_resource;
    }

    hcd->rsrc_start = res->start;
    hcd->rsrc_len = resource_size(res);
    if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
                driver->description)) {
        retval = -EBUSY;
        goto fail_request_resource;
    }

    hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
    if (hcd->regs == NULL) {
        dev_dbg(&pdev->dev, "error mapping memory\n");
        retval = -ENOMEM;
        goto fail_ioremap;
    }

    ehci = (struct spear_ehci *)hcd_to_ehci(hcd);
    ehci->clk = usbh_clk;

    spear_start_ehci(ehci);
    retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
    if (retval)
        goto fail_add_hcd;

    return retval;

fail_add_hcd:
    spear_stop_ehci(ehci);
    iounmap(hcd->regs);
fail_ioremap:
    release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
fail_request_resource:
    usb_put_hcd(hcd);
fail_create_hcd:
    clk_put(usbh_clk);
fail_get_usbh_clk:
fail_irq_get:
    dev_err(&pdev->dev, "init fail, %d\n", retval);

    return retval ;
}

static int spear_ehci_hcd_drv_remove(struct platform_device *pdev)
{
    struct usb_hcd *hcd = platform_get_drvdata(pdev);
    struct spear_ehci *ehci_p = to_spear_ehci(hcd);

    if (!hcd)
        return 0;
    if (in_interrupt())
        BUG();
    usb_remove_hcd(hcd);

    if (ehci_p->clk)
        spear_stop_ehci(ehci_p);
    iounmap(hcd->regs);
    release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
    usb_put_hcd(hcd);

    if (ehci_p->clk)
        clk_put(ehci_p->clk);

    return 0;
}

static struct of_device_id spear_ehci_id_table[] __devinitdata = {
    { .compatible = "st,spear600-ehci", },
    { },
};

static struct platform_driver spear_ehci_hcd_driver = {
    .probe      = spear_ehci_hcd_drv_probe,
    .remove     = spear_ehci_hcd_drv_remove,
    .shutdown   = usb_hcd_platform_shutdown,
    .driver     = {
        .name = "spear-ehci",
        .bus = &platform_bus_type,
        .pm = &ehci_spear_pm_ops,
        .of_match_table = of_match_ptr(spear_ehci_id_table),
    }
};

MODULE_ALIAS("platform:spear-ehci");