/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
 * (C) Copyright 2002 Hewlett-Packard Company
 *
 * USB Bus Glue for Samsung S3C2410
 *
 * Written by Christopher Hoover <ch@hpl.hp.com>
 * Based on fragments of previous driver by Russell King et al.
 *
 * Modified for S3C2410 from ohci-sa1111.c, ohci-omap.c and ohci-lh7a40.c
 *      by Ben Dooks, <ben@simtec.co.uk>
 *      Copyright (C) 2004 Simtec Electronics
 *
 * Thanks to basprog@mail.ru for updates to newer kernels
 *
 * This file is licenced under the GPL.
*/

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/platform_data/usb-ohci-s3c2410.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "ohci.h"


#define valid_port(idx) ((idx) == 1 || (idx) == 2)

/* clock device associated with the hcd */


#define DRIVER_DESC "OHCI S3C2410 driver"

static const char hcd_name[] = "ohci-s3c2410";

static struct clk *clk;
static struct clk *usb_clk;

/* forward definitions */

static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
                        u16 wValue, u16 wIndex, char *buf, u16 wLength);
static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);

static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc);

/* conversion functions */

static struct s3c2410_hcd_info *to_s3c2410_info(struct usb_hcd *hcd)
{
        return dev_get_platdata(hcd->self.controller);
}

static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd)
{
        struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

        dev_dbg(&dev->dev, "s3c2410_start_hc:\n");

        clk_prepare_enable(usb_clk);
        mdelay(2);                      /* let the bus clock stabilise */

        clk_prepare_enable(clk);

        if (info != NULL) {
                info->hcd       = hcd;
                info->report_oc = s3c2410_hcd_oc;

                if (info->enable_oc != NULL)
                        (info->enable_oc)(info, 1);
        }
}

static void s3c2410_stop_hc(struct platform_device *dev)
{
        struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

        dev_dbg(&dev->dev, "s3c2410_stop_hc:\n");

        if (info != NULL) {
                info->report_oc = NULL;
                info->hcd       = NULL;

                if (info->enable_oc != NULL)
                        (info->enable_oc)(info, 0);
        }

        clk_disable_unprepare(clk);
        clk_disable_unprepare(usb_clk);
}

/* ohci_s3c2410_hub_status_data
 *
 * update the status data from the hub with anything that
 * has been detected by our system
*/

static int
ohci_s3c2410_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
        struct s3c2410_hcd_port *port;
        int orig;
        int portno;

        orig = orig_ohci_hub_status_data(hcd, buf);

        if (info == NULL)
                return orig;

        port = &info->port[0];

        /* mark any changed port as changed */

        for (portno = 0; portno < 2; port++, portno++) {
                if (port->oc_changed == 1 &&
                    port->flags & S3C_HCDFLG_USED) {
                        dev_dbg(hcd->self.controller,
                                "oc change on port %d\n", portno);

                        if (orig < 1)
                                orig = 1;

                        buf[0] |= 1<<(portno+1);
                }
        }

        return orig;
}

/* s3c2410_usb_set_power
 *
 * configure the power on a port, by calling the platform device
 * routine registered with the platform device
*/

static void s3c2410_usb_set_power(struct s3c2410_hcd_info *info,
                                  int port, int to)
{
        if (info == NULL)
                return;

        if (info->power_control != NULL) {
                info->port[port-1].power = to;
                (info->power_control)(port-1, to);
        }
}

/* ohci_s3c2410_hub_control
 *
 * look at control requests to the hub, and see if we need
 * to take any action or over-ride the results from the
 * request.
*/

static int ohci_s3c2410_hub_control(
        struct usb_hcd  *hcd,
        u16             typeReq,
        u16             wValue,
        u16             wIndex,
        char            *buf,
        u16             wLength)
{
        struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
        struct usb_hub_descriptor *desc;
        int ret = -EINVAL;
        u32 *data = (u32 *)buf;

        dev_dbg(hcd->self.controller,
                "s3c2410_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
                hcd, typeReq, wValue, wIndex, buf, wLength);

        /* if we are only an humble host without any special capabilities
         * process the request straight away and exit */

        if (info == NULL) {
                ret = orig_ohci_hub_control(hcd, typeReq, wValue,
                                       wIndex, buf, wLength);
                goto out;
        }

        /* check the request to see if it needs handling */

        switch (typeReq) {
        case SetPortFeature:
                if (wValue == USB_PORT_FEAT_POWER) {
                        dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
                        s3c2410_usb_set_power(info, wIndex, 1);
                        goto out;
                }
                break;

        case ClearPortFeature:
                switch (wValue) {
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: C_OVER_CURRENT\n");

                        if (valid_port(wIndex)) {
                                info->port[wIndex-1].oc_changed = 0;
                                info->port[wIndex-1].oc_status = 0;
                        }

                        goto out;

                case USB_PORT_FEAT_OVER_CURRENT:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: OVER_CURRENT\n");

                        if (valid_port(wIndex))
                                info->port[wIndex-1].oc_status = 0;

                        goto out;

                case USB_PORT_FEAT_POWER:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: POWER\n");

                        if (valid_port(wIndex)) {
                                s3c2410_usb_set_power(info, wIndex, 0);
                                return 0;
                        }
                }
                break;
        }

        ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
        if (ret)
                goto out;

        switch (typeReq) {
        case GetHubDescriptor:

                /* update the hub's descriptor */

                desc = (struct usb_hub_descriptor *)buf;

                if (info->power_control == NULL)
                        return ret;

                dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
                        desc->wHubCharacteristics);

                /* remove the old configurations for power-switching, and
                 * over-current protection, and insert our new configuration
                 */

                desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
                desc->wHubCharacteristics |= cpu_to_le16(0x0001);

                if (info->enable_oc) {
                        desc->wHubCharacteristics &= ~cpu_to_le16(
                                HUB_CHAR_OCPM);
                        desc->wHubCharacteristics |=  cpu_to_le16(
                                0x0008 |
                                0x0001);
                }

                dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
                        desc->wHubCharacteristics);

                return ret;

        case GetPortStatus:
                /* check port status */

                dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);

                if (valid_port(wIndex)) {
                        if (info->port[wIndex-1].oc_changed)
                                *data |= cpu_to_le32(RH_PS_OCIC);

                        if (info->port[wIndex-1].oc_status)
                                *data |= cpu_to_le32(RH_PS_POCI);
                }
        }

 out:
        return ret;
}

/* s3c2410_hcd_oc
 *
 * handle an over-current report
*/

static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc)
{
        struct s3c2410_hcd_port *port;
        struct usb_hcd *hcd;
        unsigned long flags;
        int portno;

        if (info == NULL)
                return;

        port = &info->port[0];
        hcd = info->hcd;

        local_irq_save(flags);

        for (portno = 0; portno < 2; port++, portno++) {
                if (port_oc & (1<<portno) &&
                    port->flags & S3C_HCDFLG_USED) {
                        port->oc_status = 1;
                        port->oc_changed = 1;

                        /* ok, once over-current is detected,
                           the port needs to be powered down */
                        s3c2410_usb_set_power(info, portno+1, 0);
                }
        }

        local_irq_restore(flags);
}

/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */

/*
 * usb_hcd_s3c2410_remove - shutdown processing for HCD
 * @dev: USB Host Controller being removed
 * Context: !in_interrupt()
 *
 * Reverses the effect of usb_hcd_3c2410_probe(), first invoking
 * the HCD's stop() method.  It is always called from a thread
 * context, normally "rmmod", "apmd", or something similar.
 *
*/

static void
usb_hcd_s3c2410_remove(struct usb_hcd *hcd, struct platform_device *dev)
{
        usb_remove_hcd(hcd);
        s3c2410_stop_hc(dev);
        usb_put_hcd(hcd);
}

/**
 * usb_hcd_s3c2410_probe - initialize S3C2410-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_s3c2410_probe(const struct hc_driver *driver,
                                  struct platform_device *dev)
{
        struct usb_hcd *hcd = NULL;
        struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);
        int retval;

        s3c2410_usb_set_power(info, 1, 1);
        s3c2410_usb_set_power(info, 2, 1);

        hcd = usb_create_hcd(driver, &dev->dev, "s3c24xx");
        if (hcd == NULL)
                return -ENOMEM;

        hcd->rsrc_start = dev->resource[0].start;
        hcd->rsrc_len   = resource_size(&dev->resource[0]);

        hcd->regs = devm_ioremap_resource(&dev->dev, &dev->resource[0]);
        if (IS_ERR(hcd->regs)) {
                retval = PTR_ERR(hcd->regs);
                goto err_put;
        }

        clk = devm_clk_get(&dev->dev, "usb-host");
        if (IS_ERR(clk)) {
                dev_err(&dev->dev, "cannot get usb-host clock\n");
                retval = PTR_ERR(clk);
                goto err_put;
        }

        usb_clk = devm_clk_get(&dev->dev, "usb-bus-host");
        if (IS_ERR(usb_clk)) {
                dev_err(&dev->dev, "cannot get usb-bus-host clock\n");
                retval = PTR_ERR(usb_clk);
                goto err_put;
        }

        s3c2410_start_hc(dev, hcd);

        retval = usb_add_hcd(hcd, dev->resource[1].start, 0);
        if (retval != 0)
                goto err_ioremap;

        device_wakeup_enable(hcd->self.controller);
        return 0;

 err_ioremap:
        s3c2410_stop_hc(dev);

 err_put:
        usb_put_hcd(hcd);
        return retval;
}

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

static struct hc_driver __read_mostly ohci_s3c2410_hc_driver;

static int ohci_hcd_s3c2410_drv_probe(struct platform_device *pdev)
{
        return usb_hcd_s3c2410_probe(&ohci_s3c2410_hc_driver, pdev);
}

static int ohci_hcd_s3c2410_drv_remove(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);

        usb_hcd_s3c2410_remove(hcd, pdev);
        return 0;
}

#ifdef CONFIG_PM
static int ohci_hcd_s3c2410_drv_suspend(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct platform_device *pdev = to_platform_device(dev);
        bool do_wakeup = device_may_wakeup(dev);
        int rc = 0;

        rc = ohci_suspend(hcd, do_wakeup);
        if (rc)
                return rc;

        s3c2410_stop_hc(pdev);

        return rc;
}

static int ohci_hcd_s3c2410_drv_resume(struct device *dev)
{
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct platform_device *pdev = to_platform_device(dev);

        s3c2410_start_hc(pdev, hcd);

        ohci_resume(hcd, false);

        return 0;
}
#else
#define ohci_hcd_s3c2410_drv_suspend    NULL
#define ohci_hcd_s3c2410_drv_resume     NULL
#endif

static const struct dev_pm_ops ohci_hcd_s3c2410_pm_ops = {
        .suspend        = ohci_hcd_s3c2410_drv_suspend,
        .resume         = ohci_hcd_s3c2410_drv_resume,
};

static struct platform_driver ohci_hcd_s3c2410_driver = {
        .probe          = ohci_hcd_s3c2410_drv_probe,
        .remove         = ohci_hcd_s3c2410_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "s3c2410-ohci",
                .pm     = &ohci_hcd_s3c2410_pm_ops,
        },
};

static int __init ohci_s3c2410_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        pr_info("%s: " DRIVER_DESC "\n", hcd_name);
        ohci_init_driver(&ohci_s3c2410_hc_driver, NULL);

        /*
         * The Samsung HW has some unusual quirks, which require
         * Sumsung-specific workarounds. We override certain hc_driver
         * functions here to achieve that. We explicitly do not enhance
         * ohci_driver_overrides to allow this more easily, since this
         * is an unusual case, and we don't want to encourage others to
         * override these functions by making it too easy.
         */

        orig_ohci_hub_control = ohci_s3c2410_hc_driver.hub_control;
        orig_ohci_hub_status_data = ohci_s3c2410_hc_driver.hub_status_data;

        ohci_s3c2410_hc_driver.hub_status_data  = ohci_s3c2410_hub_status_data;
        ohci_s3c2410_hc_driver.hub_control      = ohci_s3c2410_hub_control;

        return platform_driver_register(&ohci_hcd_s3c2410_driver);
}
module_init(ohci_s3c2410_init);

static void __exit ohci_s3c2410_cleanup(void)
{
        platform_driver_unregister(&ohci_hcd_s3c2410_driver);
}
module_exit(ohci_s3c2410_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c2410-ohci");