/*
 * Driver for EHCI UHP on Atmel chips
 *
 *  Copyright (C) 2009 Atmel Corporation,
 *                     Nicolas Ferre <nicolas.ferre@atmel.com>
 *
 *  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);

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

        return ehci_setup(hcd);
}

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 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_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(hcd->regs)) {
                retval = PTR_ERR(hcd->regs);
                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 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         = ehci_atmel_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .name   = "atmel-ehci",
                .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
        },
};