ehci-atmel.c

Go to the documentation of this file.

/*
 * Driver for EHCI UHP on Atmel chips
 *
 *  Copyright (C) 2009 Atmel Corporation,
 *                     Nicolas Ferre <[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/platform_device.h>
#include <linux/of.h>
#include <linux/of_platform.h>

/* interface and function clocks */
static struct clk *iclk, *fclk;
static int clocked;

/*-------------------------------------------------------------------------*/

static void atmel_start_clock(void)
{
    clk_enable(iclk);
    clk_enable(fclk);
    clocked = 1;
}

static void atmel_stop_clock(void)
{
    clk_disable(fclk);
    clk_disable(iclk);
    clocked = 0;
}

static void atmel_start_ehci(struct platform_device *pdev)
{
    dev_dbg(&pdev->dev, "start\n");
    atmel_start_clock();
}

static void atmel_stop_ehci(struct platform_device *pdev)
{
    dev_dbg(&pdev->dev, "stop\n");
    atmel_stop_clock();
}

/*-------------------------------------------------------------------------*/

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

    /* 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_atmel_hc_driver = {
    .description        = hcd_name,
    .product_desc       = "Atmel EHCI UHP HS",
    .hcd_priv_size      = sizeof(struct ehci_hcd),

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

    /* basic lifecycle operations */
    .reset          = ehci_atmel_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 u64 at91_ehci_dma_mask = DMA_BIT_MASK(32);

static int __devinit ehci_atmel_drv_probe(struct platform_device *pdev)
{
    struct usb_hcd *hcd;
    const struct hc_driver *driver = &ehci_atmel_hc_driver;
    struct resource *res;
    int irq;
    int retval;

    if (usb_disabled())
        return -ENODEV;

    pr_debug("Initializing Atmel-SoC USB Host Controller\n");

    irq = platform_get_irq(pdev, 0);
    if (irq <= 0) {
        dev_err(&pdev->dev,
            "Found HC with no IRQ. Check %s setup!\n",
            dev_name(&pdev->dev));
        retval = -ENODEV;
        goto fail_create_hcd;
    }

    /* 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 = &at91_ehci_dma_mask;

    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) {
        dev_err(&pdev->dev,
            "Found HC with no register addr. Check %s setup!\n",
            dev_name(&pdev->dev));
        retval = -ENODEV;
        goto fail_request_resource;
    }
    hcd->rsrc_start = res->start;
    hcd->rsrc_len = resource_size(res);

    hcd->regs = devm_request_and_ioremap(&pdev->dev, res);
    if (hcd->regs == NULL) {
        dev_dbg(&pdev->dev, "error mapping memory\n");
        retval = -EFAULT;
        goto fail_request_resource;
    }

    iclk = devm_clk_get(&pdev->dev, "ehci_clk");
    if (IS_ERR(iclk)) {
        dev_err(&pdev->dev, "Error getting interface clock\n");
        retval = -ENOENT;
        goto fail_request_resource;
    }
    fclk = devm_clk_get(&pdev->dev, "uhpck");
    if (IS_ERR(fclk)) {
        dev_err(&pdev->dev, "Error getting function clock\n");
        retval = -ENOENT;
        goto fail_request_resource;
    }

    atmel_start_ehci(pdev);

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

    return retval;

fail_add_hcd:
    atmel_stop_ehci(pdev);
fail_request_resource:
    usb_put_hcd(hcd);
fail_create_hcd:
    dev_err(&pdev->dev, "init %s fail, %d\n",
        dev_name(&pdev->dev), retval);

    return retval;
}

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

    ehci_shutdown(hcd);
    usb_remove_hcd(hcd);
    usb_put_hcd(hcd);

    atmel_stop_ehci(pdev);
    fclk = iclk = NULL;

    return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id atmel_ehci_dt_ids[] = {
    { .compatible = "atmel,at91sam9g45-ehci" },
    { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
#endif

static struct platform_driver ehci_atmel_driver = {
    .probe      = ehci_atmel_drv_probe,
    .remove     = __devexit_p(ehci_atmel_drv_remove),
    .shutdown   = usb_hcd_platform_shutdown,
    .driver     = {
        .name   = "atmel-ehci",
        .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
    },
};