/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 *  Copyright (C) 2004 SAN People (Pty) Ltd.
 *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
 *
 * AT91 Bus Glue
 *
 * Based on fragments of 2.4 driver by Rick Bronson.
 * Based on ohci-omap.c
 *
 * This file is licenced under the GPL.
 */

#include <linux/clk.h>
#include <linux/platform_device.h>

#include <mach/hardware.h>
#include <asm/gpio.h>

#include <mach/board.h>
#include <mach/cpu.h>

#ifndef CONFIG_ARCH_AT91
#error "CONFIG_ARCH_AT91 must be defined."
#endif

/* interface and function clocks; sometimes also an AHB clock */
static struct clk *iclk, *fclk, *hclk;
static int clocked;

extern int usb_disabled(void);

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

static void at91_start_clock(void)
{
        if (cpu_is_at91sam9261())
                clk_enable(hclk);
        clk_enable(iclk);
        clk_enable(fclk);
        clocked = 1;
}

static void at91_stop_clock(void)
{
        clk_disable(fclk);
        clk_disable(iclk);
        if (cpu_is_at91sam9261())
                clk_disable(hclk);
        clocked = 0;
}

static void at91_start_hc(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ohci_regs __iomem *regs = hcd->regs;

        dev_dbg(&pdev->dev, "start\n");

        /*
         * Start the USB clocks.
         */
        at91_start_clock();

        /*
         * The USB host controller must remain in reset.
         */
        writel(0, &regs->control);
}

static void at91_stop_hc(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ohci_regs __iomem *regs = hcd->regs;

        dev_dbg(&pdev->dev, "stop\n");

        /*
         * Put the USB host controller into reset.
         */
        writel(0, &regs->control);

        /*
         * Stop the USB clocks.
         */
        at91_stop_clock();
}


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

static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);

/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */


/**
 * usb_hcd_at91_probe - initialize AT91-based HCDs
 * Context: !in_interrupt()
 *
 * Allocates basic resources for this USB host controller, and
 * then invokes the start() method for the HCD associated with it
 * through the hotplug entry's driver_data.
 */
static int usb_hcd_at91_probe(const struct hc_driver *driver,
                        struct platform_device *pdev)
{
        int retval;
        struct usb_hcd *hcd = NULL;

        if (pdev->num_resources != 2) {
                pr_debug("hcd probe: invalid num_resources");
                return -ENODEV;
        }

        if ((pdev->resource[0].flags != IORESOURCE_MEM)
                        || (pdev->resource[1].flags != IORESOURCE_IRQ)) {
                pr_debug("hcd probe: invalid resource type\n");
                return -ENODEV;
        }

        hcd = usb_create_hcd(driver, &pdev->dev, "at91");
        if (!hcd)
                return -ENOMEM;
        hcd->rsrc_start = pdev->resource[0].start;
        hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;

        if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
                pr_debug("request_mem_region failed\n");
                retval = -EBUSY;
                goto err1;
        }

        hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
        if (!hcd->regs) {
                pr_debug("ioremap failed\n");
                retval = -EIO;
                goto err2;
        }

        iclk = clk_get(&pdev->dev, "ohci_clk");
        fclk = clk_get(&pdev->dev, "uhpck");
        if (cpu_is_at91sam9261())
                hclk = clk_get(&pdev->dev, "hck0");

        at91_start_hc(pdev);
        ohci_hcd_init(hcd_to_ohci(hcd));

        retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
        if (retval == 0)
                return retval;

        /* Error handling */
        at91_stop_hc(pdev);

        if (cpu_is_at91sam9261())
                clk_put(hclk);
        clk_put(fclk);
        clk_put(iclk);

        iounmap(hcd->regs);

 err2:
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);

 err1:
        usb_put_hcd(hcd);
        return retval;
}


/* may be called with controller, bus, and devices active */

/**
 * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 * @dev: USB Host Controller being removed
 * Context: !in_interrupt()
 *
 * Reverses the effect of usb_hcd_at91_probe(), first invoking
 * the HCD's stop() method.  It is always called from a thread
 * context, "rmmod" or something similar.
 *
 */
static void usb_hcd_at91_remove(struct usb_hcd *hcd,
                                struct platform_device *pdev)
{
        usb_remove_hcd(hcd);
        at91_stop_hc(pdev);
        iounmap(hcd->regs);
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
        usb_put_hcd(hcd);

        if (cpu_is_at91sam9261())
                clk_put(hclk);
        clk_put(fclk);
        clk_put(iclk);
        fclk = iclk = hclk = NULL;

        dev_set_drvdata(&pdev->dev, NULL);
}

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

static int __devinit
ohci_at91_start (struct usb_hcd *hcd)
{
        struct at91_usbh_data   *board = hcd->self.controller->platform_data;
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        int                     ret;

        if ((ret = ohci_init(ohci)) < 0)
                return ret;

        ohci->num_ports = board->ports;

        if ((ret = ohci_run(ohci)) < 0) {
                err("can't start %s", hcd->self.bus_name);
                ohci_stop(hcd);
                return ret;
        }
        return 0;
}

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

static const struct hc_driver ohci_at91_hc_driver = {
        .description =          hcd_name,
        .product_desc =         "AT91 OHCI",
        .hcd_priv_size =        sizeof(struct ohci_hcd),

        /*
         * generic hardware linkage
         */
        .irq =                  ohci_irq,
        .flags =                HCD_USB11 | HCD_MEMORY,

        /*
         * basic lifecycle operations
         */
        .start =                ohci_at91_start,
        .stop =                 ohci_stop,
        .shutdown =             ohci_shutdown,

        /*
         * managing i/o requests and associated device resources
         */
        .urb_enqueue =          ohci_urb_enqueue,
        .urb_dequeue =          ohci_urb_dequeue,
        .endpoint_disable =     ohci_endpoint_disable,

        /*
         * scheduling support
         */
        .get_frame_number =     ohci_get_frame,

        /*
         * root hub support
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
#ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,
#endif
        .start_port_reset =     ohci_start_port_reset,
};

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

static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
{
        struct at91_usbh_data   *pdata = pdev->dev.platform_data;
        int                     i;

        if (pdata) {
                /* REVISIT make the driver support per-port power switching,
                 * and also overcurrent detection.  Here we assume the ports
                 * are always powered while this driver is active, and use
                 * active-low power switches.
                 */
                for (i = 0; i < ARRAY_SIZE(pdata->vbus_pin); i++) {
                        if (pdata->vbus_pin[i] <= 0)
                                continue;
                        gpio_request(pdata->vbus_pin[i], "ohci_vbus");
                        gpio_direction_output(pdata->vbus_pin[i], 0);
                }
        }

        device_init_wakeup(&pdev->dev, 1);
        return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
}

static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
{
        struct at91_usbh_data   *pdata = pdev->dev.platform_data;
        int                     i;

        if (pdata) {
                for (i = 0; i < ARRAY_SIZE(pdata->vbus_pin); i++) {
                        if (pdata->vbus_pin[i] <= 0)
                                continue;
                        gpio_direction_output(pdata->vbus_pin[i], 1);
                        gpio_free(pdata->vbus_pin[i]);
                }
        }

        device_init_wakeup(&pdev->dev, 0);
        usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
        return 0;
}

#ifdef CONFIG_PM

static int
ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
{
        struct usb_hcd  *hcd = platform_get_drvdata(pdev);
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);

        if (device_may_wakeup(&pdev->dev))
                enable_irq_wake(hcd->irq);

        /*
         * The integrated transceivers seem unable to notice disconnect,
         * reconnect, or wakeup without the 48 MHz clock active.  so for
         * correctness, always discard connection state (using reset).
         *
         * REVISIT: some boards will be able to turn VBUS off...
         */
        if (at91_suspend_entering_slow_clock()) {
                ohci_usb_reset (ohci);
                at91_stop_clock();
        }

        return 0;
}

static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
{
        struct usb_hcd  *hcd = platform_get_drvdata(pdev);

        if (device_may_wakeup(&pdev->dev))
                disable_irq_wake(hcd->irq);

        if (!clocked)
                at91_start_clock();

        ohci_finish_controller_resume(hcd);
        return 0;
}
#else
#define ohci_hcd_at91_drv_suspend NULL
#define ohci_hcd_at91_drv_resume  NULL
#endif

MODULE_ALIAS("platform:at91_ohci");

static struct platform_driver ohci_hcd_at91_driver = {
        .probe          = ohci_hcd_at91_drv_probe,
        .remove         = ohci_hcd_at91_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .suspend        = ohci_hcd_at91_drv_suspend,
        .resume         = ohci_hcd_at91_drv_resume,
        .driver         = {
                .name   = "at91_ohci",
                .owner  = THIS_MODULE,
        },
};