/*
* Driver for EHCI HCD on SPEAr SOC
*
* Copyright (C) 2010 ST Micro Electronics,
* Deepak Sikri <deepak.sikri@st.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/dma-mapping.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "ehci.h"

#define DRIVER_DESC "EHCI SPEAr driver"

static const char hcd_name[] = "SPEAr-ehci";

struct spear_ehci {
        struct clk *clk;
};

#define to_spear_ehci(hcd)      (struct spear_ehci *)(hcd_to_ehci(hcd)->priv)

static struct hc_driver __read_mostly ehci_spear_hc_driver;

#ifdef CONFIG_PM_SLEEP
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_SLEEP */

static SIMPLE_DEV_PM_OPS(ehci_spear_pm_ops, ehci_spear_drv_suspend,
                ehci_spear_drv_resume);

static int spear_ehci_hcd_drv_probe(struct platform_device *pdev)
{
        struct usb_hcd *hcd ;
        struct spear_ehci *sehci;
        struct resource *res;
        struct clk *usbh_clk;
        const struct hc_driver *driver = &ehci_spear_hc_driver;
        int irq, retval;

        if (usb_disabled())
                return -ENODEV;

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

        /*
         * 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 = &pdev->dev.coherent_dma_mask;
        if (!pdev->dev.coherent_dma_mask)
                pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

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

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

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

        hcd->rsrc_start = res->start;
        hcd->rsrc_len = resource_size(res);
        if (!devm_request_mem_region(&pdev->dev, hcd->rsrc_start, hcd->rsrc_len,
                                driver->description)) {
                retval = -EBUSY;
                goto err_put_hcd;
        }

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

        sehci = to_spear_ehci(hcd);
        sehci->clk = usbh_clk;

        /* registers start at offset 0x0 */
        hcd_to_ehci(hcd)->caps = hcd->regs;

        clk_prepare_enable(sehci->clk);
        retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (retval)
                goto err_stop_ehci;

        return retval;

err_stop_ehci:
        clk_disable_unprepare(sehci->clk);
err_put_hcd:
        usb_put_hcd(hcd);
fail:
        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 *sehci = to_spear_ehci(hcd);

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

        if (sehci->clk)
                clk_disable_unprepare(sehci->clk);
        usb_put_hcd(hcd);

        return 0;
}

static struct of_device_id spear_ehci_id_table[] = {
        { .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),
        }
};

static const struct ehci_driver_overrides spear_overrides __initdata = {
        .extra_priv_size = sizeof(struct spear_ehci),
};

static int __init ehci_spear_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        pr_info("%s: " DRIVER_DESC "\n", hcd_name);

        ehci_init_driver(&ehci_spear_hc_driver, &spear_overrides);
        return platform_driver_register(&spear_ehci_hcd_driver);
}
module_init(ehci_spear_init);

static void __exit ehci_spear_cleanup(void)
{
        platform_driver_unregister(&spear_ehci_hcd_driver);
}
module_exit(ehci_spear_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_ALIAS("platform:spear-ehci");
MODULE_AUTHOR("Deepak Sikri");
MODULE_LICENSE("GPL");