text: /*
   * dummy_hcd.c -- Dummy/Loopback USB host and device emulator driver.
   *
   * Maintainer: Alan Stern <stern@rowland.harvard.edu>
   *
   * Copyright (C) 2003 David Brownell
   * Copyright (C) 2003-2005 Alan Stern
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  
  /*
   * This exposes a device side "USB gadget" API, driven by requests to a
   * Linux-USB host controller driver.  USB traffic is simulated; there's
   * no need for USB hardware.  Use this with two other drivers:
   *
   *  - Gadget driver, responding to requests (slave);
   *  - Host-side device driver, as already familiar in Linux.
   *
   * Having this all in one kernel can help some stages of development,
   * bypassing some hardware (and driver) issues.  UML could help too.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/ioport.h>
  #include <linux/slab.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/timer.h>
  #include <linux/list.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  #include <linux/usb.h>
  #include <linux/usb/gadget.h>
  #include <linux/usb/hcd.h>
  #include <linux/scatterlist.h>
  
  #include <asm/byteorder.h>
  #include <linux/io.h>
  #include <asm/irq.h>
  #include <asm/unaligned.h>
  
  #define DRIVER_DESC	"USB Host+Gadget Emulator"
  #define DRIVER_VERSION	"02 May 2005"
  
  #define POWER_BUDGET	500	/* in mA; use 8 for low-power port testing */
  
  static const char	driver_name[] = "dummy_hcd";
  static const char	driver_desc[] = "USB Host+Gadget Emulator";
  
  static const char	gadget_name[] = "dummy_udc";
  
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_AUTHOR("David Brownell");
  MODULE_LICENSE("GPL");
  
  struct dummy_hcd_module_parameters {
  	bool is_super_speed;
  	bool is_high_speed;
  	unsigned int num;
  };
  
  static struct dummy_hcd_module_parameters mod_data = {
  	.is_super_speed = false,
  	.is_high_speed = true,
  	.num = 1,
  };
  module_param_named(is_super_speed, mod_data.is_super_speed, bool, S_IRUGO);
  MODULE_PARM_DESC(is_super_speed, "true to simulate SuperSpeed connection");
  module_param_named(is_high_speed, mod_data.is_high_speed, bool, S_IRUGO);
  MODULE_PARM_DESC(is_high_speed, "true to simulate HighSpeed connection");
  module_param_named(num, mod_data.num, uint, S_IRUGO);
  MODULE_PARM_DESC(num, "number of emulated controllers");
  /*-------------------------------------------------------------------------*/
  
  /* gadget side driver data structres */
  struct dummy_ep {
  	struct list_head		queue;
  	unsigned long			last_io;	/* jiffies timestamp */
  	struct usb_gadget		*gadget;
  	const struct usb_endpoint_descriptor *desc;
  	struct usb_ep			ep;
  	unsigned			halted:1;
  	unsigned			wedged:1;
  	unsigned			already_seen:1;
  	unsigned			setup_stage:1;
  	unsigned			stream_en:1;
  };
  
  struct dummy_request {
  	struct list_head		queue;		/* ep's requests */
  	struct usb_request		req;
  };
  
  static inline struct dummy_ep *usb_ep_to_dummy_ep(struct usb_ep *_ep)
  {
  	return container_of(_ep, struct dummy_ep, ep);
  }
  
  static inline struct dummy_request *usb_request_to_dummy_request
  		(struct usb_request *_req)
  {
  	return container_of(_req, struct dummy_request, req);
  }
  
  /*-------------------------------------------------------------------------*/
  
  /*
   * Every device has ep0 for control requests, plus up to 30 more endpoints,
   * in one of two types:
   *
   *   - Configurable:  direction (in/out), type (bulk, iso, etc), and endpoint
   *     number can be changed.  Names like "ep-a" are used for this type.
   *
   *   - Fixed Function:  in other cases.  some characteristics may be mutable;
   *     that'd be hardware-specific.  Names like "ep12out-bulk" are used.
   *
   * Gadget drivers are responsible for not setting up conflicting endpoint
   * configurations, illegal or unsupported packet lengths, and so on.
   */
  
  static const char ep0name[] = "ep0";
  
  static const struct {
  	const char *name;
  	const struct usb_ep_caps caps;
  } ep_info[] = {
  #define EP_INFO(_name, _caps) \
  	{ \
  		.name = _name, \
  		.caps = _caps, \
  	}
  
  	/* everyone has ep0 */
  	EP_INFO(ep0name,
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
  	/* act like a pxa250: fifteen fixed function endpoints */
  	EP_INFO("ep1in-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep2out-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep3in-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep4out-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep5in-int",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep6in-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep7out-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep8in-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep9out-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep10in-int",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep11in-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep12out-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep13in-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep14out-iso",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep15in-int",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
  	/* or like sa1100: two fixed function endpoints */
  	EP_INFO("ep1out-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep2in-bulk",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
  	/* and now some generic EPs so we have enough in multi config */
  	EP_INFO("ep3out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep4in",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep5out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep6out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep7in",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep8out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep9in",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep10out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep11out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep12in",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep13out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  	EP_INFO("ep14in",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
  	EP_INFO("ep15out",
  		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
  
  #undef EP_INFO
  };
  
  #define DUMMY_ENDPOINTS	ARRAY_SIZE(ep_info)
  
  /*-------------------------------------------------------------------------*/
  
  #define FIFO_SIZE		64
  
  struct urbp {
  	struct urb		*urb;
  	struct list_head	urbp_list;
  	struct sg_mapping_iter	miter;
  	u32			miter_started;
  };
  
  
  enum dummy_rh_state {
  	DUMMY_RH_RESET,
  	DUMMY_RH_SUSPENDED,
  	DUMMY_RH_RUNNING
  };
  
  struct dummy_hcd {
  	struct dummy			*dum;
  	enum dummy_rh_state		rh_state;
  	struct timer_list		timer;
  	u32				port_status;
  	u32				old_status;
  	unsigned long			re_timeout;
  
  	struct usb_device		*udev;
  	struct list_head		urbp_list;
  	u32				stream_en_ep;
  	u8				num_stream[30 / 2];
  
  	unsigned			active:1;
  	unsigned			old_active:1;
  	unsigned			resuming:1;
  };
  
  struct dummy {
  	spinlock_t			lock;
  
  	/*
  	 * SLAVE/GADGET side support
  	 */
  	struct dummy_ep			ep[DUMMY_ENDPOINTS];
  	int				address;
  	struct usb_gadget		gadget;
  	struct usb_gadget_driver	*driver;
  	struct dummy_request		fifo_req;
  	u8				fifo_buf[FIFO_SIZE];
  	u16				devstatus;
  	unsigned			udc_suspended:1;
  	unsigned			pullup:1;
  
  	/*
  	 * MASTER/HOST side support
  	 */
  	struct dummy_hcd		*hs_hcd;
  	struct dummy_hcd		*ss_hcd;
  };
  
  static inline struct dummy_hcd *hcd_to_dummy_hcd(struct usb_hcd *hcd)
  {
  	return (struct dummy_hcd *) (hcd->hcd_priv);
  }
  
  static inline struct usb_hcd *dummy_hcd_to_hcd(struct dummy_hcd *dum)
  {
  	return container_of((void *) dum, struct usb_hcd, hcd_priv);
  }
  
  static inline struct device *dummy_dev(struct dummy_hcd *dum)
  {
  	return dummy_hcd_to_hcd(dum)->self.controller;
  }
  
  static inline struct device *udc_dev(struct dummy *dum)
  {
  	return dum->gadget.dev.parent;
  }
  
  static inline struct dummy *ep_to_dummy(struct dummy_ep *ep)
  {
  	return container_of(ep->gadget, struct dummy, gadget);
  }
  
  static inline struct dummy_hcd *gadget_to_dummy_hcd(struct usb_gadget *gadget)
  {
  	struct dummy *dum = container_of(gadget, struct dummy, gadget);
  	if (dum->gadget.speed == USB_SPEED_SUPER)
  		return dum->ss_hcd;
  	else
  		return dum->hs_hcd;
  }
  
  static inline struct dummy *gadget_dev_to_dummy(struct device *dev)
  {
  	return container_of(dev, struct dummy, gadget.dev);
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* SLAVE/GADGET SIDE UTILITY ROUTINES */
  
  /* called with spinlock held */
  static void nuke(struct dummy *dum, struct dummy_ep *ep)
  {
  	while (!list_empty(&ep->queue)) {
  		struct dummy_request	*req;
  
  		req = list_entry(ep->queue.next, struct dummy_request, queue);
  		list_del_init(&req->queue);
  		req->req.status = -ESHUTDOWN;
  
  		spin_unlock(&dum->lock);
  		usb_gadget_giveback_request(&ep->ep, &req->req);
  		spin_lock(&dum->lock);
  	}
  }
  
  /* caller must hold lock */
  static void stop_activity(struct dummy *dum)
  {
  	int i;
  
  	/* prevent any more requests */
  	dum->address = 0;
  
  	/* The timer is left running so that outstanding URBs can fail */
  
  	/* nuke any pending requests first, so driver i/o is quiesced */
  	for (i = 0; i < DUMMY_ENDPOINTS; ++i)
  		nuke(dum, &dum->ep[i]);
  
  	/* driver now does any non-usb quiescing necessary */
  }
  
  /**
   * set_link_state_by_speed() - Sets the current state of the link according to
   *	the hcd speed
   * @dum_hcd: pointer to the dummy_hcd structure to update the link state for
   *
   * This function updates the port_status according to the link state and the
   * speed of the hcd.
   */
  static void set_link_state_by_speed(struct dummy_hcd *dum_hcd)
  {
  	struct dummy *dum = dum_hcd->dum;
  
  	if (dummy_hcd_to_hcd(dum_hcd)->speed == HCD_USB3) {
  		if ((dum_hcd->port_status & USB_SS_PORT_STAT_POWER) == 0) {
  			dum_hcd->port_status = 0;
  		} else if (!dum->pullup || dum->udc_suspended) {
  			/* UDC suspend must cause a disconnect */
  			dum_hcd->port_status &= ~(USB_PORT_STAT_CONNECTION |
  						USB_PORT_STAT_ENABLE);
  			if ((dum_hcd->old_status &
  			     USB_PORT_STAT_CONNECTION) != 0)
  				dum_hcd->port_status |=
  					(USB_PORT_STAT_C_CONNECTION << 16);
  		} else {
  			/* device is connected and not suspended */
  			dum_hcd->port_status |= (USB_PORT_STAT_CONNECTION |
  						 USB_PORT_STAT_SPEED_5GBPS) ;
  			if ((dum_hcd->old_status &
  			     USB_PORT_STAT_CONNECTION) == 0)
  				dum_hcd->port_status |=
  					(USB_PORT_STAT_C_CONNECTION << 16);
  			if ((dum_hcd->port_status &
  			     USB_PORT_STAT_ENABLE) == 1 &&
  				(dum_hcd->port_status &
  				 USB_SS_PORT_LS_U0) == 1 &&
  				dum_hcd->rh_state != DUMMY_RH_SUSPENDED)
  				dum_hcd->active = 1;
  		}
  	} else {
  		if ((dum_hcd->port_status & USB_PORT_STAT_POWER) == 0) {
  			dum_hcd->port_status = 0;
  		} else if (!dum->pullup || dum->udc_suspended) {
  			/* UDC suspend must cause a disconnect */
  			dum_hcd->port_status &= ~(USB_PORT_STAT_CONNECTION |
  						USB_PORT_STAT_ENABLE |
  						USB_PORT_STAT_LOW_SPEED |
  						USB_PORT_STAT_HIGH_SPEED |
  						USB_PORT_STAT_SUSPEND);
  			if ((dum_hcd->old_status &
  			     USB_PORT_STAT_CONNECTION) != 0)
  				dum_hcd->port_status |=
  					(USB_PORT_STAT_C_CONNECTION << 16);
  		} else {
  			dum_hcd->port_status |= USB_PORT_STAT_CONNECTION;
  			if ((dum_hcd->old_status &
  			     USB_PORT_STAT_CONNECTION) == 0)
  				dum_hcd->port_status |=
  					(USB_PORT_STAT_C_CONNECTION << 16);
  			if ((dum_hcd->port_status & USB_PORT_STAT_ENABLE) == 0)
  				dum_hcd->port_status &= ~USB_PORT_STAT_SUSPEND;
  			else if ((dum_hcd->port_status &
  				  USB_PORT_STAT_SUSPEND) == 0 &&
  					dum_hcd->rh_state != DUMMY_RH_SUSPENDED)
  				dum_hcd->active = 1;
  		}
  	}
  }
  
  /* caller must hold lock */
  static void set_link_state(struct dummy_hcd *dum_hcd)
  {
  	struct dummy *dum = dum_hcd->dum;
  
  	dum_hcd->active = 0;
  	if (dum->pullup)
  		if ((dummy_hcd_to_hcd(dum_hcd)->speed == HCD_USB3 &&
  		     dum->gadget.speed != USB_SPEED_SUPER) ||
  		    (dummy_hcd_to_hcd(dum_hcd)->speed != HCD_USB3 &&
  		     dum->gadget.speed == USB_SPEED_SUPER))
  			return;
  
  	set_link_state_by_speed(dum_hcd);
  
  	if ((dum_hcd->port_status & USB_PORT_STAT_ENABLE) == 0 ||
  	     dum_hcd->active)
  		dum_hcd->resuming = 0;
  
  	/* Currently !connected or in reset */
  	if ((dum_hcd->port_status & USB_PORT_STAT_CONNECTION) == 0 ||
  			(dum_hcd->port_status & USB_PORT_STAT_RESET) != 0) {
  		unsigned disconnect = USB_PORT_STAT_CONNECTION &
  				dum_hcd->old_status & (~dum_hcd->port_status);
  		unsigned reset = USB_PORT_STAT_RESET &
  				(~dum_hcd->old_status) & dum_hcd->port_status;
  
  		/* Report reset and disconnect events to the driver */
  		if (dum->driver && (disconnect || reset)) {
  			stop_activity(dum);
  			spin_unlock(&dum->lock);
  			if (reset)
  				usb_gadget_udc_reset(&dum->gadget, dum->driver);
  			else
  				dum->driver->disconnect(&dum->gadget);
  			spin_lock(&dum->lock);
  		}
  	} else if (dum_hcd->active != dum_hcd->old_active) {
  		if (dum_hcd->old_active && dum->driver->suspend) {
  			spin_unlock(&dum->lock);
  			dum->driver->suspend(&dum->gadget);
  			spin_lock(&dum->lock);
  		} else if (!dum_hcd->old_active &&  dum->driver->resume) {
  			spin_unlock(&dum->lock);
  			dum->driver->resume(&dum->gadget);
  			spin_lock(&dum->lock);
  		}
  	}
  
  	dum_hcd->old_status = dum_hcd->port_status;
  	dum_hcd->old_active = dum_hcd->active;
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* SLAVE/GADGET SIDE DRIVER
   *
   * This only tracks gadget state.  All the work is done when the host
   * side tries some (emulated) i/o operation.  Real device controller
   * drivers would do real i/o using dma, fifos, irqs, timers, etc.
   */
  
  #define is_enabled(dum) \
  	(dum->port_status & USB_PORT_STAT_ENABLE)
  
  static int dummy_enable(struct usb_ep *_ep,
  		const struct usb_endpoint_descriptor *desc)
  {
  	struct dummy		*dum;
  	struct dummy_hcd	*dum_hcd;
  	struct dummy_ep		*ep;
  	unsigned		max;
  	int			retval;
  
  	ep = usb_ep_to_dummy_ep(_ep);
  	if (!_ep || !desc || ep->desc || _ep->name == ep0name
  			|| desc->bDescriptorType != USB_DT_ENDPOINT)
  		return -EINVAL;
  	dum = ep_to_dummy(ep);
  	if (!dum->driver)
  		return -ESHUTDOWN;
  
  	dum_hcd = gadget_to_dummy_hcd(&dum->gadget);
  	if (!is_enabled(dum_hcd))
  		return -ESHUTDOWN;
  
  	/*
  	 * For HS/FS devices only bits 0..10 of the wMaxPacketSize represent the
  	 * maximum packet size.
  	 * For SS devices the wMaxPacketSize is limited by 1024.
  	 */
  	max = usb_endpoint_maxp(desc) & 0x7ff;
  
  	/* drivers must not request bad settings, since lower levels
  	 * (hardware or its drivers) may not check.  some endpoints
  	 * can't do iso, many have maxpacket limitations, etc.
  	 *
  	 * since this "hardware" driver is here to help debugging, we
  	 * have some extra sanity checks.  (there could be more though,
  	 * especially for "ep9out" style fixed function ones.)
  	 */
  	retval = -EINVAL;
  	switch (usb_endpoint_type(desc)) {
  	case USB_ENDPOINT_XFER_BULK:
  		if (strstr(ep->ep.name, "-iso")
  				|| strstr(ep->ep.name, "-int")) {
  			goto done;
  		}
  		switch (dum->gadget.speed) {
  		case USB_SPEED_SUPER:
  			if (max == 1024)
  				break;
  			goto done;
  		case USB_SPEED_HIGH:
  			if (max == 512)
  				break;
  			goto done;
  		case USB_SPEED_FULL:
  			if (max == 8 || max == 16 || max == 32 || max == 64)
  				/* we'll fake any legal size */
  				break;
  			/* save a return statement */
  		default:
  			goto done;
  		}
  		break;
  	case USB_ENDPOINT_XFER_INT:
  		if (strstr(ep->ep.name, "-iso")) /* bulk is ok */
  			goto done;
  		/* real hardware might not handle all packet sizes */
  		switch (dum->gadget.speed) {
  		case USB_SPEED_SUPER:
  		case USB_SPEED_HIGH:
  			if (max <= 1024)
  				break;
  			/* save a return statement */
  		case USB_SPEED_FULL:
  			if (max <= 64)
  				break;
  			/* save a return statement */
  		default:
  			if (max <= 8)
  				break;
  			goto done;
  		}
  		break;
  	case USB_ENDPOINT_XFER_ISOC:
  		if (strstr(ep->ep.name, "-bulk")
  				|| strstr(ep->ep.name, "-int"))
  			goto done;
  		/* real hardware might not handle all packet sizes */
  		switch (dum->gadget.speed) {
  		case USB_SPEED_SUPER:
  		case USB_SPEED_HIGH:
  			if (max <= 1024)
  				break;
  			/* save a return statement */
  		case USB_SPEED_FULL:
  			if (max <= 1023)
  				break;
  			/* save a return statement */
  		default:
  			goto done;
  		}
  		break;
  	default:
  		/* few chips support control except on ep0 */
  		goto done;
  	}
  
  	_ep->maxpacket = max;
  	if (usb_ss_max_streams(_ep->comp_desc)) {
  		if (!usb_endpoint_xfer_bulk(desc)) {
  			dev_err(udc_dev(dum), "Can't enable stream support on "
  					"non-bulk ep %s\n", _ep->name);
  			return -EINVAL;
  		}
  		ep->stream_en = 1;
  	}
  	ep->desc = desc;
  
  	dev_dbg(udc_dev(dum), "enabled %s (ep%d%s-%s) maxpacket %d stream %s\n",
  		_ep->name,
  		desc->bEndpointAddress & 0x0f,
  		(desc->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
  		({ char *val;
  		 switch (usb_endpoint_type(desc)) {
  		 case USB_ENDPOINT_XFER_BULK:
  			 val = "bulk";
  			 break;
  		 case USB_ENDPOINT_XFER_ISOC:
  			 val = "iso";
  			 break;
  		 case USB_ENDPOINT_XFER_INT:
  			 val = "intr";
  			 break;
  		 default:
  			 val = "ctrl";
  			 break;
  		 } val; }),
  		max, ep->stream_en ? "enabled" : "disabled");
  
  	/* at this point real hardware should be NAKing transfers
  	 * to that endpoint, until a buffer is queued to it.
  	 */
  	ep->halted = ep->wedged = 0;
  	retval = 0;
  done:
  	return retval;
  }
  
  static int dummy_disable(struct usb_ep *_ep)
  {
  	struct dummy_ep		*ep;
  	struct dummy		*dum;
  	unsigned long		flags;
  
  	ep = usb_ep_to_dummy_ep(_ep);
  	if (!_ep || !ep->desc || _ep->name == ep0name)
  		return -EINVAL;
  	dum = ep_to_dummy(ep);
  
  	spin_lock_irqsave(&dum->lock, flags);
  	ep->desc = NULL;
  	ep->stream_en = 0;
  	nuke(dum, ep);
  	spin_unlock_irqrestore(&dum->lock, flags);
  
  	dev_dbg(udc_dev(dum), "disabled %s\n", _ep->name);
  	return 0;
  }
  
  static struct usb_request *dummy_alloc_request(struct usb_ep *_ep,
  		gfp_t mem_flags)
  {
  	struct dummy_request	*req;
  
  	if (!_ep)
  		return NULL;
  
  	req = kzalloc(sizeof(*req), mem_flags);
  	if (!req)
  		return NULL;
  	INIT_LIST_HEAD(&req->queue);
  	return &req->req;
  }
  
  static void dummy_free_request(struct usb_ep *_ep, struct usb_request *_req)
  {
  	struct dummy_request	*req;
  
  	if (!_ep || !_req) {
  		WARN_ON(1);
  		return;
  	}
  
  	req = usb_request_to_dummy_request(_req);
  	WARN_ON(!list_empty(&req->queue));
  	kfree(req);
  }
  
  static void fifo_complete(struct usb_ep *ep, struct usb_request *req)
  {
  }
  
  static int dummy_queue(struct usb_ep *_ep, struct usb_request *_req,
  		gfp_t mem_flags)
  {
  	struct dummy_ep		*ep;
  	struct dummy_request	*req;
  	struct dummy		*dum;
  	struct dummy_hcd	*dum_hcd;
  	unsigned long		flags;
  
  	req = usb_request_to_dummy_request(_req);
  	if (!_req || !list_empty(&req->queue) || !_req->complete)
  		return -EINVAL;
  
  	ep = usb_ep_to_dummy_ep(_ep);
  	if (!_ep || (!ep->desc && _ep->name != ep0name))
  		return -EINVAL;
  
  	dum = ep_to_dummy(ep);
  	dum_hcd = gadget_to_dummy_hcd(&dum->gadget);
  	if (!dum->driver || !is_enabled(dum_hcd))
  		return -ESHUTDOWN;
  
  #if 0
  	dev_dbg(udc_dev(dum), "ep %p queue req %p to %s, len %d buf %p\n",
  			ep, _req, _ep->name, _req->length, _req->buf);
  #endif
  	_req->status = -EINPROGRESS;
  	_req->actual = 0;
  	spin_lock_irqsave(&dum->lock, flags);
  
  	/* implement an emulated single-request FIFO */
  	if (ep->desc && (ep->desc->bEndpointAddress & USB_DIR_IN) &&
  			list_empty(&dum->fifo_req.queue) &&
  			list_empty(&ep->queue) &&
  			_req->length <= FIFO_SIZE) {
  		req = &dum->fifo_req;
  		req->req = *_req;
  		req->req.buf = dum->fifo_buf;
  		memcpy(dum->fifo_buf, _req->buf, _req->length);
  		req->req.context = dum;
  		req->req.complete = fifo_complete;
  
  		list_add_tail(&req->queue, &ep->queue);
  		spin_unlock(&dum->lock);
  		_req->actual = _req->length;
  		_req->status = 0;
  		usb_gadget_giveback_request(_ep, _req);
  		spin_lock(&dum->lock);
  	}  else
  		list_add_tail(&req->queue, &ep->queue);
  	spin_unlock_irqrestore(&dum->lock, flags);
  
  	/* real hardware would likely enable transfers here, in case
  	 * it'd been left NAKing.
  	 */
  	return 0;
  }
  
  static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
  {
  	struct dummy_ep		*ep;
  	struct dummy		*dum;
  	int			retval = -EINVAL;
  	unsigned long		flags;
  	struct dummy_request	*req = NULL;
  
  	if (!_ep || !_req)
  		return retval;
  	ep = usb_ep_to_dummy_ep(_ep);
  	dum = ep_to_dummy(ep);
  
  	if (!dum->driver)
  		return -ESHUTDOWN;
  
  	local_irq_save(flags);
  	spin_lock(&dum->lock);
  	list_for_each_entry(req, &ep->queue, queue) {
  		if (&req->req == _req) {
  			list_del_init(&req->queue);
  			_req->status = -ECONNRESET;
  			retval = 0;
  			break;
  		}
  	}
  	spin_unlock(&dum->lock);
  
  	if (retval == 0) {
  		dev_dbg(udc_dev(dum),
  				"dequeued req %p from %s, len %d buf %p\n",
  				req, _ep->name, _req->length, _req->buf);
  		usb_gadget_giveback_request(_ep, _req);
  	}
  	local_irq_restore(flags);
  	return retval;
  }
  
  static int
  dummy_set_halt_and_wedge(struct usb_ep *_ep, int value, int wedged)
  {
  	struct dummy_ep		*ep;
  	struct dummy		*dum;
  
  	if (!_ep)
  		return -EINVAL;
  	ep = usb_ep_to_dummy_ep(_ep);
  	dum = ep_to_dummy(ep);
  	if (!dum->driver)
  		return -ESHUTDOWN;
  	if (!value)
  		ep->halted = ep->wedged = 0;
  	else if (ep->desc && (ep->desc->bEndpointAddress & USB_DIR_IN) &&
  			!list_empty(&ep->queue))
  		return -EAGAIN;
  	else {
  		ep->halted = 1;
  		if (wedged)
  			ep->wedged = 1;
  	}
  	/* FIXME clear emulated data toggle too */
  	return 0;
  }
  
  static int
  dummy_set_halt(struct usb_ep *_ep, int value)
  {
  	return dummy_set_halt_and_wedge(_ep, value, 0);
  }
  
  static int dummy_set_wedge(struct usb_ep *_ep)
  {
  	if (!_ep || _ep->name == ep0name)
  		return -EINVAL;
  	return dummy_set_halt_and_wedge(_ep, 1, 1);
  }
  
  static const struct usb_ep_ops dummy_ep_ops = {
  	.enable		= dummy_enable,
  	.disable	= dummy_disable,
  
  	.alloc_request	= dummy_alloc_request,
  	.free_request	= dummy_free_request,
  
  	.queue		= dummy_queue,
  	.dequeue	= dummy_dequeue,
  
  	.set_halt	= dummy_set_halt,
  	.set_wedge	= dummy_set_wedge,
  };
  
  /*-------------------------------------------------------------------------*/
  
  /* there are both host and device side versions of this call ... */
  static int dummy_g_get_frame(struct usb_gadget *_gadget)
  {
  	struct timespec64 ts64;
  
  	ktime_get_ts64(&ts64);
  	return ts64.tv_nsec / NSEC_PER_MSEC;
  }
  
  static int dummy_wakeup(struct usb_gadget *_gadget)
  {
  	struct dummy_hcd *dum_hcd;
  
  	dum_hcd = gadget_to_dummy_hcd(_gadget);
  	if (!(dum_hcd->dum->devstatus & ((1 << USB_DEVICE_B_HNP_ENABLE)
  				| (1 << USB_DEVICE_REMOTE_WAKEUP))))
  		return -EINVAL;
  	if ((dum_hcd->port_status & USB_PORT_STAT_CONNECTION) == 0)
  		return -ENOLINK;
  	if ((dum_hcd->port_status & USB_PORT_STAT_SUSPEND) == 0 &&
  			 dum_hcd->rh_state != DUMMY_RH_SUSPENDED)
  		return -EIO;
  
  	/* FIXME: What if the root hub is suspended but the port isn't? */
  
  	/* hub notices our request, issues downstream resume, etc */
  	dum_hcd->resuming = 1;
  	dum_hcd->re_timeout = jiffies + msecs_to_jiffies(20);
  	mod_timer(&dummy_hcd_to_hcd(dum_hcd)->rh_timer, dum_hcd->re_timeout);
  	return 0;
  }
  
  static int dummy_set_selfpowered(struct usb_gadget *_gadget, int value)
  {
  	struct dummy	*dum;
  
  	_gadget->is_selfpowered = (value != 0);
  	dum = gadget_to_dummy_hcd(_gadget)->dum;
  	if (value)
  		dum->devstatus |= (1 << USB_DEVICE_SELF_POWERED);
  	else
  		dum->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
  	return 0;
  }
  
  static void dummy_udc_update_ep0(struct dummy *dum)
  {
  	if (dum->gadget.speed == USB_SPEED_SUPER)
  		dum->ep[0].ep.maxpacket = 9;
  	else
  		dum->ep[0].ep.maxpacket = 64;
  }
  
  static int dummy_pullup(struct usb_gadget *_gadget, int value)
  {
  	struct dummy_hcd *dum_hcd;
  	struct dummy	*dum;
  	unsigned long	flags;
  
  	dum = gadget_dev_to_dummy(&_gadget->dev);
  
  	if (value && dum->driver) {
  		if (mod_data.is_super_speed)
  			dum->gadget.speed = dum->driver->max_speed;
  		else if (mod_data.is_high_speed)
  			dum->gadget.speed = min_t(u8, USB_SPEED_HIGH,
  					dum->driver->max_speed);
  		else
  			dum->gadget.speed = USB_SPEED_FULL;
  		dummy_udc_update_ep0(dum);
  
  		if (dum->gadget.speed < dum->driver->max_speed)
  			dev_dbg(udc_dev(dum), "This device can perform faster"
  				" if you connect it to a %s port...\n",
  				usb_speed_string(dum->driver->max_speed));
  	}
  	dum_hcd = gadget_to_dummy_hcd(_gadget);
  
  	spin_lock_irqsave(&dum->lock, flags);
  	dum->pullup = (value != 0);
  	set_link_state(dum_hcd);
  	spin_unlock_irqrestore(&dum->lock, flags);
  
  	usb_hcd_poll_rh_status(dummy_hcd_to_hcd(dum_hcd));
  	return 0;
  }
  
  static int dummy_udc_start(struct usb_gadget *g,
  		struct usb_gadget_driver *driver);
  static int dummy_udc_stop(struct usb_gadget *g);
  
  static const struct usb_gadget_ops dummy_ops = {
  	.get_frame	= dummy_g_get_frame,
  	.wakeup		= dummy_wakeup,
  	.set_selfpowered = dummy_set_selfpowered,
  	.pullup		= dummy_pullup,
  	.udc_start	= dummy_udc_start,
  	.udc_stop	= dummy_udc_stop,
  };
  
  /*-------------------------------------------------------------------------*/
  
  /* "function" sysfs attribute */
  static ssize_t function_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct dummy	*dum = gadget_dev_to_dummy(dev);
  
  	if (!dum->driver || !dum->driver->function)
  		return 0;
  	return scnprintf(buf, PAGE_SIZE, "%s\n", dum->driver->function);
  }
  static DEVICE_ATTR_RO(function);
  
  /*-------------------------------------------------------------------------*/
  
  /*
   * Driver registration/unregistration.
   *
   * This is basically hardware-specific; there's usually only one real USB
   * device (not host) controller since that's how USB devices are intended
   * to work.  So most implementations of these api calls will rely on the
   * fact that only one driver will ever bind to the hardware.  But curious
   * hardware can be built with discrete components, so the gadget API doesn't
   * require that assumption.
   *
   * For this emulator, it might be convenient to create a usb slave device
   * for each driver that registers:  just add to a big root hub.
   */
  
  static int dummy_udc_start(struct usb_gadget *g,
  		struct usb_gadget_driver *driver)
  {
  	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(g);
  	struct dummy		*dum = dum_hcd->dum;
  
  	if (driver->max_speed == USB_SPEED_UNKNOWN)
  		return -EINVAL;
  
  	/*
  	 * SLAVE side init ... the layer above hardware, which
  	 * can't enumerate without help from the driver we're binding.
  	 */
  
  	dum->devstatus = 0;
  	dum->driver = driver;
  
  	return 0;
  }
  
  static int dummy_udc_stop(struct usb_gadget *g)
  {
  	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(g);
  	struct dummy		*dum = dum_hcd->dum;
  
  	dum->driver = NULL;
  
  	return 0;
  }
  
  #undef is_enabled
  
  /* The gadget structure is stored inside the hcd structure and will be
   * released along with it. */
  static void init_dummy_udc_hw(struct dummy *dum)
  {
  	int i;
  
  	INIT_LIST_HEAD(&dum->gadget.ep_list);
  	for (i = 0; i < DUMMY_ENDPOINTS; i++) {
  		struct dummy_ep	*ep = &dum->ep[i];
  
  		if (!ep_info[i].name)
  			break;
  		ep->ep.name = ep_info[i].name;
  		ep->ep.caps = ep_info[i].caps;
  		ep->ep.ops = &dummy_ep_ops;
  		list_add_tail(&ep->ep.ep_list, &dum->gadget.ep_list);
  		ep->halted = ep->wedged = ep->already_seen =
  				ep->setup_stage = 0;
  		usb_ep_set_maxpacket_limit(&ep->ep, ~0);
  		ep->ep.max_streams = 16;
  		ep->last_io = jiffies;
  		ep->gadget = &dum->gadget;
  		ep->desc = NULL;
  		INIT_LIST_HEAD(&ep->queue);
  	}
  
  	dum->gadget.ep0 = &dum->ep[0].ep;
  	list_del_init(&dum->ep[0].ep.ep_list);
  	INIT_LIST_HEAD(&dum->fifo_req.queue);
  
  #ifdef CONFIG_USB_OTG
  	dum->gadget.is_otg = 1;
  #endif
  }
  
  static int dummy_udc_probe(struct platform_device *pdev)
  {
  	struct dummy	*dum;
  	int		rc;
  
  	dum = *((void **)dev_get_platdata(&pdev->dev));
  	dum->gadget.name = gadget_name;
  	dum->gadget.ops = &dummy_ops;
  	dum->gadget.max_speed = USB_SPEED_SUPER;
  
  	dum->gadget.dev.parent = &pdev->dev;
  	init_dummy_udc_hw(dum);
  
  	rc = usb_add_gadget_udc(&pdev->dev, &dum->gadget);
  	if (rc < 0)
  		goto err_udc;
  
  	rc = device_create_file(&dum->gadget.dev, &dev_attr_function);
  	if (rc < 0)
  		goto err_dev;
  	platform_set_drvdata(pdev, dum);
  	return rc;
  
  err_dev:
  	usb_del_gadget_udc(&dum->gadget);
  err_udc:
  	return rc;
  }
  
  static int dummy_udc_remove(struct platform_device *pdev)
  {
  	struct dummy	*dum = platform_get_drvdata(pdev);
  
  	device_remove_file(&dum->gadget.dev, &dev_attr_function);
  	usb_del_gadget_udc(&dum->gadget);
  	return 0;
  }
  
  static void dummy_udc_pm(struct dummy *dum, struct dummy_hcd *dum_hcd,
  		int suspend)
  {
  	spin_lock_irq(&dum->lock);
  	dum->udc_suspended = suspend;
  	set_link_state(dum_hcd);
  	spin_unlock_irq(&dum->lock);
  }
  
  static int dummy_udc_suspend(struct platform_device *pdev, pm_message_t state)
  {
  	struct dummy		*dum = platform_get_drvdata(pdev);
  	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(&dum->gadget);
  
  	dev_dbg(&pdev->dev, "%s\n", __func__);
  	dummy_udc_pm(dum, dum_hcd, 1);
  	usb_hcd_poll_rh_status(dummy_hcd_to_hcd(dum_hcd));
  	return 0;
  }
  
  static int dummy_udc_resume(struct platform_device *pdev)
  {
  	struct dummy		*dum = platform_get_drvdata(pdev);
  	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(&dum->gadget);
  
  	dev_dbg(&pdev->dev, "%s\n", __func__);
  	dummy_udc_pm(dum, dum_hcd, 0);
  	usb_hcd_poll_rh_status(dummy_hcd_to_hcd(dum_hcd));
  	return 0;
  }
  
  static struct platform_driver dummy_udc_driver = {
  	.probe		= dummy_udc_probe,
  	.remove		= dummy_udc_remove,
  	.suspend	= dummy_udc_suspend,
  	.resume		= dummy_udc_resume,
  	.driver		= {
  		.name	= (char *) gadget_name,
  	},
  };
  
  /*-------------------------------------------------------------------------*/
  
  static unsigned int dummy_get_ep_idx(const struct usb_endpoint_descriptor *desc)
  {
  	unsigned int index;
  
  	index = usb_endpoint_num(desc) << 1;
  	if (usb_endpoint_dir_in(desc))
  		index |= 1;
  	return index;
  }
  
  /* MASTER/HOST SIDE DRIVER
   *
   * this uses the hcd framework to hook up to host side drivers.
   * its root hub will only have one device, otherwise it acts like
   * a normal host controller.
   *
   * when urbs are queued, they're just stuck on a list that we
   * scan in a timer callback.  that callback connects writes from
   * the host with reads from the device, and so on, based on the
   * usb 2.0 rules.
   */
  
  static int dummy_ep_stream_en(struct dummy_hcd *dum_hcd, struct urb *urb)
  {
  	const struct usb_endpoint_descriptor *desc = &urb->ep->desc;
  	u32 index;
  
  	if (!usb_endpoint_xfer_bulk(desc))
  		return 0;
  
  	index = dummy_get_ep_idx(desc);
  	return (1 << index) & dum_hcd->stream_en_ep;
  }
  
  /*
   * The max stream number is saved as a nibble so for the 30 possible endpoints
   * we only 15 bytes of memory. Therefore we are limited to max 16 streams (0
   * means we use only 1 stream). The maximum according to the spec is 16bit so
   * if the 16 stream limit is about to go, the array size should be incremented
   * to 30 elements of type u16.
   */
  static int get_max_streams_for_pipe(struct dummy_hcd *dum_hcd,
  		unsigned int pipe)
  {
  	int max_streams;
  
  	max_streams = dum_hcd->num_stream[usb_pipeendpoint(pipe)];
  	if (usb_pipeout(pipe))
  		max_streams >>= 4;
  	else
  		max_streams &= 0xf;
  	max_streams++;
  	return max_streams;
  }
  
  static void set_max_streams_for_pipe(struct dummy_hcd *dum_hcd,
  		unsigned int pipe, unsigned int streams)
  {
  	int max_streams;
  
  	streams--;
  	max_streams = dum_hcd->num_stream[usb_pipeendpoint(pipe)];
  	if (usb_pipeout(pipe)) {
  		streams <<= 4;
  		max_streams &= 0xf;
  	} else {
  		max_streams &= 0xf0;
  	}
  	max_streams |= streams;
  	dum_hcd->num_stream[usb_pipeendpoint(pipe)] = max_streams;
  }
  
  static int dummy_validate_stream(struct dummy_hcd *dum_hcd, struct urb *urb)
  {
  	unsigned int max_streams;
  	int enabled;
  
  	enabled = dummy_ep_stream_en(dum_hcd, urb);
  	if (!urb->stream_id) {
  		if (enabled)
  			return -EINVAL;
  		return 0;
  	}
  	if (!enabled)
  		return -EINVAL;
  
  	max_streams = get_max_streams_for_pipe(dum_hcd,
  			usb_pipeendpoint(urb->pipe));
  	if (urb->stream_id > max_streams) {
  		dev_err(dummy_dev(dum_hcd), "Stream id %d is out of range.\n",
  				urb->stream_id);
  		BUG();
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static int dummy_urb_enqueue(
  	struct usb_hcd			*hcd,
  	struct urb			*urb,
  	gfp_t				mem_flags
  ) {
  	struct dummy_hcd *dum_hcd;
  	struct urbp	*urbp;
  	unsigned long	flags;
  	int		rc;
  
  	urbp = kmalloc(sizeof *urbp, mem_flags);
  	if (!urbp)
  		return -ENOMEM;
  	urbp->urb = urb;
  	urbp->miter_started = 0;
  
  	dum_hcd = hcd_to_dummy_hcd(hcd);
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  
  	rc = dummy_validate_stream(dum_hcd, urb);
  	if (rc) {
  		kfree(urbp);
  		goto done;
  	}
  
  	rc = usb_hcd_link_urb_to_ep(hcd, urb);
  	if (rc) {
  		kfree(urbp);
  		goto done;
  	}
  
  	if (!dum_hcd->udev) {
  		dum_hcd->udev = urb->dev;
  		usb_get_dev(dum_hcd->udev);
  	} else if (unlikely(dum_hcd->udev != urb->dev))
  		dev_err(dummy_dev(dum_hcd), "usb_device address has changed!\n");
  
  	list_add_tail(&urbp->urbp_list, &dum_hcd->urbp_list);
  	urb->hcpriv = urbp;
  	if (usb_pipetype(urb->pipe) == PIPE_CONTROL)
  		urb->error_count = 1;		/* mark as a new urb */
  
  	/* kick the scheduler, it'll do the rest */
  	if (!timer_pending(&dum_hcd->timer))
  		mod_timer(&dum_hcd->timer, jiffies + 1);
  
   done:
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  	return rc;
  }
  
  static int dummy_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
  {
  	struct dummy_hcd *dum_hcd;
  	unsigned long	flags;
  	int		rc;
  
  	/* giveback happens automatically in timer callback,
  	 * so make sure the callback happens */
  	dum_hcd = hcd_to_dummy_hcd(hcd);
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  
  	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
  	if (!rc && dum_hcd->rh_state != DUMMY_RH_RUNNING &&
  			!list_empty(&dum_hcd->urbp_list))
  		mod_timer(&dum_hcd->timer, jiffies);
  
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  	return rc;
  }
  
  static int dummy_perform_transfer(struct urb *urb, struct dummy_request *req,
  		u32 len)
  {
  	void *ubuf, *rbuf;
  	struct urbp *urbp = urb->hcpriv;
  	int to_host;
  	struct sg_mapping_iter *miter = &urbp->miter;
  	u32 trans = 0;
  	u32 this_sg;
  	bool next_sg;
  
  	to_host = usb_pipein(urb->pipe);
  	rbuf = req->req.buf + req->req.actual;
  
  	if (!urb->num_sgs) {
  		ubuf = urb->transfer_buffer + urb->actual_length;
  		if (to_host)
  			memcpy(ubuf, rbuf, len);
  		else
  			memcpy(rbuf, ubuf, len);
  		return len;
  	}
  
  	if (!urbp->miter_started) {
  		u32 flags = SG_MITER_ATOMIC;
  
  		if (to_host)
  			flags |= SG_MITER_TO_SG;
  		else
  			flags |= SG_MITER_FROM_SG;
  
  		sg_miter_start(miter, urb->sg, urb->num_sgs, flags);
  		urbp->miter_started = 1;
  	}
  	next_sg = sg_miter_next(miter);
  	if (next_sg == false) {
  		WARN_ON_ONCE(1);
  		return -EINVAL;
  	}
  	do {
  		ubuf = miter->addr;
  		this_sg = min_t(u32, len, miter->length);
  		miter->consumed = this_sg;
  		trans += this_sg;
  
  		if (to_host)
  			memcpy(ubuf, rbuf, this_sg);
  		else
  			memcpy(rbuf, ubuf, this_sg);
  		len -= this_sg;
  
  		if (!len)
  			break;
  		next_sg = sg_miter_next(miter);
  		if (next_sg == false) {
  			WARN_ON_ONCE(1);
  			return -EINVAL;
  		}
  
  		rbuf += this_sg;
  	} while (1);
  
  	sg_miter_stop(miter);
  	return trans;
  }
  
  /* transfer up to a frame's worth; caller must own lock */
  static int transfer(struct dummy_hcd *dum_hcd, struct urb *urb,
  		struct dummy_ep *ep, int limit, int *status)
  {
  	struct dummy		*dum = dum_hcd->dum;
  	struct dummy_request	*req;
  	int			sent = 0;
  
  top:
  	/* if there's no request queued, the device is NAKing; return */
  	list_for_each_entry(req, &ep->queue, queue) {
  		unsigned	host_len, dev_len, len;
  		int		is_short, to_host;
  		int		rescan = 0;
  
  		if (dummy_ep_stream_en(dum_hcd, urb)) {
  			if ((urb->stream_id != req->req.stream_id))
  				continue;
  		}
  
  		/* 1..N packets of ep->ep.maxpacket each ... the last one
  		 * may be short (including zero length).
  		 *
  		 * writer can send a zlp explicitly (length 0) or implicitly
  		 * (length mod maxpacket zero, and 'zero' flag); they always
  		 * terminate reads.
  		 */
  		host_len = urb->transfer_buffer_length - urb->actual_length;
  		dev_len = req->req.length - req->req.actual;
  		len = min(host_len, dev_len);
  
  		/* FIXME update emulated data toggle too */
  
  		to_host = usb_pipein(urb->pipe);
  		if (unlikely(len == 0))
  			is_short = 1;
  		else {
  			/* not enough bandwidth left? */
  			if (limit < ep->ep.maxpacket && limit < len)
  				break;
  			len = min_t(unsigned, len, limit);
  			if (len == 0)
  				break;
  
  			/* send multiple of maxpacket first, then remainder */
  			if (len >= ep->ep.maxpacket) {
  				is_short = 0;
  				if (len % ep->ep.maxpacket)
  					rescan = 1;
  				len -= len % ep->ep.maxpacket;
  			} else {
  				is_short = 1;
  			}
  
  			len = dummy_perform_transfer(urb, req, len);
  
  			ep->last_io = jiffies;
  			if ((int)len < 0) {
  				req->req.status = len;
  			} else {
  				limit -= len;
  				sent += len;
  				urb->actual_length += len;
  				req->req.actual += len;
  			}
  		}
  
  		/* short packets terminate, maybe with overflow/underflow.
  		 * it's only really an error to write too much.
  		 *
  		 * partially filling a buffer optionally blocks queue advances
  		 * (so completion handlers can clean up the queue) but we don't
  		 * need to emulate such data-in-flight.
  		 */
  		if (is_short) {
  			if (host_len == dev_len) {
  				req->req.status = 0;
  				*status = 0;
  			} else if (to_host) {
  				req->req.status = 0;
  				if (dev_len > host_len)
  					*status = -EOVERFLOW;
  				else
  					*status = 0;
  			} else {
  				*status = 0;
  				if (host_len > dev_len)
  					req->req.status = -EOVERFLOW;
  				else
  					req->req.status = 0;
  			}
  
  		/*
  		 * many requests terminate without a short packet.
  		 * send a zlp if demanded by flags.
  		 */
  		} else {
  			if (req->req.length == req->req.actual) {
  				if (req->req.zero && to_host)
  					rescan = 1;
  				else
  					req->req.status = 0;
  			}
  			if (urb->transfer_buffer_length == urb->actual_length) {
  				if (urb->transfer_flags & URB_ZERO_PACKET &&
  				    !to_host)
  					rescan = 1;
  				else
  					*status = 0;
  			}
  		}
  
  		/* device side completion --> continuable */
  		if (req->req.status != -EINPROGRESS) {
  			list_del_init(&req->queue);
  
  			spin_unlock(&dum->lock);
  			usb_gadget_giveback_request(&ep->ep, &req->req);
  			spin_lock(&dum->lock);
  
  			/* requests might have been unlinked... */
  			rescan = 1;
  		}
  
  		/* host side completion --> terminate */
  		if (*status != -EINPROGRESS)
  			break;
  
  		/* rescan to continue with any other queued i/o */
  		if (rescan)
  			goto top;
  	}
  	return sent;
  }
  
  static int periodic_bytes(struct dummy *dum, struct dummy_ep *ep)
  {
  	int	limit = ep->ep.maxpacket;
  
  	if (dum->gadget.speed == USB_SPEED_HIGH) {
  		int	tmp;
  
  		/* high bandwidth mode */
  		tmp = usb_endpoint_maxp(ep->desc);
  		tmp = (tmp >> 11) & 0x03;
  		tmp *= 8 /* applies to entire frame */;
  		limit += limit * tmp;
  	}
  	if (dum->gadget.speed == USB_SPEED_SUPER) {
  		switch (usb_endpoint_type(ep->desc)) {
  		case USB_ENDPOINT_XFER_ISOC:
  			/* Sec. 4.4.8.2 USB3.0 Spec */
  			limit = 3 * 16 * 1024 * 8;
  			break;
  		case USB_ENDPOINT_XFER_INT:
  			/* Sec. 4.4.7.2 USB3.0 Spec */
  			limit = 3 * 1024 * 8;
  			break;
  		case USB_ENDPOINT_XFER_BULK:
  		default:
  			break;
  		}
  	}
  	return limit;
  }
  
  #define is_active(dum_hcd)	((dum_hcd->port_status & \
  		(USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE | \
  			USB_PORT_STAT_SUSPEND)) \
  		== (USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE))
  
  static struct dummy_ep *find_endpoint(struct dummy *dum, u8 address)
  {
  	int		i;
  
  	if (!is_active((dum->gadget.speed == USB_SPEED_SUPER ?
  			dum->ss_hcd : dum->hs_hcd)))
  		return NULL;
  	if ((address & ~USB_DIR_IN) == 0)
  		return &dum->ep[0];
  	for (i = 1; i < DUMMY_ENDPOINTS; i++) {
  		struct dummy_ep	*ep = &dum->ep[i];
  
  		if (!ep->desc)
  			continue;
  		if (ep->desc->bEndpointAddress == address)
  			return ep;
  	}
  	return NULL;
  }
  
  #undef is_active
  
  #define Dev_Request	(USB_TYPE_STANDARD | USB_RECIP_DEVICE)
  #define Dev_InRequest	(Dev_Request | USB_DIR_IN)
  #define Intf_Request	(USB_TYPE_STANDARD | USB_RECIP_INTERFACE)
  #define Intf_InRequest	(Intf_Request | USB_DIR_IN)
  #define Ep_Request	(USB_TYPE_STANDARD | USB_RECIP_ENDPOINT)
  #define Ep_InRequest	(Ep_Request | USB_DIR_IN)
  
  
  /**
   * handle_control_request() - handles all control transfers
   * @dum: pointer to dummy (the_controller)
   * @urb: the urb request to handle
   * @setup: pointer to the setup data for a USB device control
   *	 request
   * @status: pointer to request handling status
   *
   * Return 0 - if the request was handled
   *	  1 - if the request wasn't handles
   *	  error code on error
   */
  static int handle_control_request(struct dummy_hcd *dum_hcd, struct urb *urb,
  				  struct usb_ctrlrequest *setup,
  				  int *status)
  {
  	struct dummy_ep		*ep2;
  	struct dummy		*dum = dum_hcd->dum;
  	int			ret_val = 1;
  	unsigned	w_index;
  	unsigned	w_value;
  
  	w_index = le16_to_cpu(setup->wIndex);
  	w_value = le16_to_cpu(setup->wValue);
  	switch (setup->bRequest) {
  	case USB_REQ_SET_ADDRESS:
  		if (setup->bRequestType != Dev_Request)
  			break;
  		dum->address = w_value;
  		*status = 0;
  		dev_dbg(udc_dev(dum), "set_address = %d\n",
  				w_value);
  		ret_val = 0;
  		break;
  	case USB_REQ_SET_FEATURE:
  		if (setup->bRequestType == Dev_Request) {
  			ret_val = 0;
  			switch (w_value) {
  			case USB_DEVICE_REMOTE_WAKEUP:
  				break;
  			case USB_DEVICE_B_HNP_ENABLE:
  				dum->gadget.b_hnp_enable = 1;
  				break;
  			case USB_DEVICE_A_HNP_SUPPORT:
  				dum->gadget.a_hnp_support = 1;
  				break;
  			case USB_DEVICE_A_ALT_HNP_SUPPORT:
  				dum->gadget.a_alt_hnp_support = 1;
  				break;
  			case USB_DEVICE_U1_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_U1_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			case USB_DEVICE_U2_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_U2_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			case USB_DEVICE_LTM_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_LTM_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			default:
  				ret_val = -EOPNOTSUPP;
  			}
  			if (ret_val == 0) {
  				dum->devstatus |= (1 << w_value);
  				*status = 0;
  			}
  		} else if (setup->bRequestType == Ep_Request) {
  			/* endpoint halt */
  			ep2 = find_endpoint(dum, w_index);
  			if (!ep2 || ep2->ep.name == ep0name) {
  				ret_val = -EOPNOTSUPP;
  				break;
  			}
  			ep2->halted = 1;
  			ret_val = 0;
  			*status = 0;
  		}
  		break;
  	case USB_REQ_CLEAR_FEATURE:
  		if (setup->bRequestType == Dev_Request) {
  			ret_val = 0;
  			switch (w_value) {
  			case USB_DEVICE_REMOTE_WAKEUP:
  				w_value = USB_DEVICE_REMOTE_WAKEUP;
  				break;
  			case USB_DEVICE_U1_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_U1_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			case USB_DEVICE_U2_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_U2_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			case USB_DEVICE_LTM_ENABLE:
  				if (dummy_hcd_to_hcd(dum_hcd)->speed ==
  				    HCD_USB3)
  					w_value = USB_DEV_STAT_LTM_ENABLED;
  				else
  					ret_val = -EOPNOTSUPP;
  				break;
  			default:
  				ret_val = -EOPNOTSUPP;
  				break;
  			}
  			if (ret_val == 0) {
  				dum->devstatus &= ~(1 << w_value);
  				*status = 0;
  			}
  		} else if (setup->bRequestType == Ep_Request) {
  			/* endpoint halt */
  			ep2 = find_endpoint(dum, w_index);
  			if (!ep2) {
  				ret_val = -EOPNOTSUPP;
  				break;
  			}
  			if (!ep2->wedged)
  				ep2->halted = 0;
  			ret_val = 0;
  			*status = 0;
  		}
  		break;
  	case USB_REQ_GET_STATUS:
  		if (setup->bRequestType == Dev_InRequest
  				|| setup->bRequestType == Intf_InRequest
  				|| setup->bRequestType == Ep_InRequest) {
  			char *buf;
  			/*
  			 * device: remote wakeup, selfpowered
  			 * interface: nothing
  			 * endpoint: halt
  			 */
  			buf = (char *)urb->transfer_buffer;
  			if (urb->transfer_buffer_length > 0) {
  				if (setup->bRequestType == Ep_InRequest) {
  					ep2 = find_endpoint(dum, w_index);
  					if (!ep2) {
  						ret_val = -EOPNOTSUPP;
  						break;
  					}
  					buf[0] = ep2->halted;
  				} else if (setup->bRequestType ==
  					   Dev_InRequest) {
  					buf[0] = (u8)dum->devstatus;
  				} else
  					buf[0] = 0;
  			}
  			if (urb->transfer_buffer_length > 1)
  				buf[1] = 0;
  			urb->actual_length = min_t(u32, 2,
  				urb->transfer_buffer_length);
  			ret_val = 0;
  			*status = 0;
  		}
  		break;
  	}
  	return ret_val;
  }
  
  /* drive both sides of the transfers; looks like irq handlers to
   * both drivers except the callbacks aren't in_irq().
   */
  static void dummy_timer(unsigned long _dum_hcd)
  {
  	struct dummy_hcd	*dum_hcd = (struct dummy_hcd *) _dum_hcd;
  	struct dummy		*dum = dum_hcd->dum;
  	struct urbp		*urbp, *tmp;
  	unsigned long		flags;
  	int			limit, total;
  	int			i;
  
  	/* simplistic model for one frame's bandwidth */
  	switch (dum->gadget.speed) {
  	case USB_SPEED_LOW:
  		total = 8/*bytes*/ * 12/*packets*/;
  		break;
  	case USB_SPEED_FULL:
  		total = 64/*bytes*/ * 19/*packets*/;
  		break;
  	case USB_SPEED_HIGH:
  		total = 512/*bytes*/ * 13/*packets*/ * 8/*uframes*/;
  		break;
  	case USB_SPEED_SUPER:
  		/* Bus speed is 500000 bytes/ms, so use a little less */
  		total = 490000;
  		break;
  	default:
  		dev_err(dummy_dev(dum_hcd), "bogus device speed\n");
  		return;
  	}
  
  	/* FIXME if HZ != 1000 this will probably misbehave ... */
  
  	/* look at each urb queued by the host side driver */
  	spin_lock_irqsave(&dum->lock, flags);
  
  	if (!dum_hcd->udev) {
  		dev_err(dummy_dev(dum_hcd),
  				"timer fired with no URBs pending?\n");
  		spin_unlock_irqrestore(&dum->lock, flags);
  		return;
  	}
  
  	for (i = 0; i < DUMMY_ENDPOINTS; i++) {
  		if (!ep_info[i].name)
  			break;
  		dum->ep[i].already_seen = 0;
  	}
  
  restart:
  	list_for_each_entry_safe(urbp, tmp, &dum_hcd->urbp_list, urbp_list) {
  		struct urb		*urb;
  		struct dummy_request	*req;
  		u8			address;
  		struct dummy_ep		*ep = NULL;
  		int			type;
  		int			status = -EINPROGRESS;
  
  		urb = urbp->urb;
  		if (urb->unlinked)
  			goto return_urb;
  		else if (dum_hcd->rh_state != DUMMY_RH_RUNNING)
  			continue;
  		type = usb_pipetype(urb->pipe);
  
  		/* used up this frame's non-periodic bandwidth?
  		 * FIXME there's infinite bandwidth for control and
  		 * periodic transfers ... unrealistic.
  		 */
  		if (total <= 0 && type == PIPE_BULK)
  			continue;
  
  		/* find the gadget's ep for this request (if configured) */
  		address = usb_pipeendpoint (urb->pipe);
  		if (usb_pipein(urb->pipe))
  			address |= USB_DIR_IN;
  		ep = find_endpoint(dum, address);
  		if (!ep) {
  			/* set_configuration() disagreement */
  			dev_dbg(dummy_dev(dum_hcd),
  				"no ep configured for urb %p\n",
  				urb);
  			status = -EPROTO;
  			goto return_urb;
  		}
  
  		if (ep->already_seen)
  			continue;
  		ep->already_seen = 1;
  		if (ep == &dum->ep[0] && urb->error_count) {
  			ep->setup_stage = 1;	/* a new urb */
  			urb->error_count = 0;
  		}
  		if (ep->halted && !ep->setup_stage) {
  			/* NOTE: must not be iso! */
  			dev_dbg(dummy_dev(dum_hcd), "ep %s halted, urb %p\n",
  					ep->ep.name, urb);
  			status = -EPIPE;
  			goto return_urb;
  		}
  		/* FIXME make sure both ends agree on maxpacket */
  
  		/* handle control requests */
  		if (ep == &dum->ep[0] && ep->setup_stage) {
  			struct usb_ctrlrequest		setup;
  			int				value = 1;
  
  			setup = *(struct usb_ctrlrequest *) urb->setup_packet;
  			/* paranoia, in case of stale queued data */
  			list_for_each_entry(req, &ep->queue, queue) {
  				list_del_init(&req->queue);
  				req->req.status = -EOVERFLOW;
  				dev_dbg(udc_dev(dum), "stale req = %p\n",
  						req);
  
  				spin_unlock(&dum->lock);
  				usb_gadget_giveback_request(&ep->ep, &req->req);
  				spin_lock(&dum->lock);
  				ep->already_seen = 0;
  				goto restart;
  			}
  
  			/* gadget driver never sees set_address or operations
  			 * on standard feature flags.  some hardware doesn't
  			 * even expose them.
  			 */
  			ep->last_io = jiffies;
  			ep->setup_stage = 0;
  			ep->halted = 0;
  
  			value = handle_control_request(dum_hcd, urb, &setup,
  						       &status);
  
  			/* gadget driver handles all other requests.  block
  			 * until setup() returns; no reentrancy issues etc.
  			 */
  			if (value > 0) {
  				spin_unlock(&dum->lock);
  				value = dum->driver->setup(&dum->gadget,
  						&setup);
  				spin_lock(&dum->lock);
  
  				if (value >= 0) {
  					/* no delays (max 64KB data stage) */
  					limit = 64*1024;
  					goto treat_control_like_bulk;
  				}
  				/* error, see below */
  			}
  
  			if (value < 0) {
  				if (value != -EOPNOTSUPP)
  					dev_dbg(udc_dev(dum),
  						"setup --> %d\n",
  						value);
  				status = -EPIPE;
  				urb->actual_length = 0;
  			}
  
  			goto return_urb;
  		}
  
  		/* non-control requests */
  		limit = total;
  		switch (usb_pipetype(urb->pipe)) {
  		case PIPE_ISOCHRONOUS:
  			/* FIXME is it urb->interval since the last xfer?
  			 * use urb->iso_frame_desc[i].
  			 * complete whether or not ep has requests queued.
  			 * report random errors, to debug drivers.
  			 */
  			limit = max(limit, periodic_bytes(dum, ep));
  			status = -ENOSYS;
  			break;
  
  		case PIPE_INTERRUPT:
  			/* FIXME is it urb->interval since the last xfer?
  			 * this almost certainly polls too fast.
  			 */
  			limit = max(limit, periodic_bytes(dum, ep));
  			/* FALLTHROUGH */
  
  		default:
  treat_control_like_bulk:
  			ep->last_io = jiffies;
  			total -= transfer(dum_hcd, urb, ep, limit, &status);
  			break;
  		}
  
  		/* incomplete transfer? */
  		if (status == -EINPROGRESS)
  			continue;
  
  return_urb:
  		list_del(&urbp->urbp_list);
  		kfree(urbp);
  		if (ep)
  			ep->already_seen = ep->setup_stage = 0;
  
  		usb_hcd_unlink_urb_from_ep(dummy_hcd_to_hcd(dum_hcd), urb);
  		spin_unlock(&dum->lock);
  		usb_hcd_giveback_urb(dummy_hcd_to_hcd(dum_hcd), urb, status);
  		spin_lock(&dum->lock);
  
  		goto restart;
  	}
  
  	if (list_empty(&dum_hcd->urbp_list)) {
  		usb_put_dev(dum_hcd->udev);
  		dum_hcd->udev = NULL;
  	} else if (dum_hcd->rh_state == DUMMY_RH_RUNNING) {
  		/* want a 1 msec delay here */
  		mod_timer(&dum_hcd->timer, jiffies + msecs_to_jiffies(1));
  	}
  
  	spin_unlock_irqrestore(&dum->lock, flags);
  }
  
  /*-------------------------------------------------------------------------*/
  
  #define PORT_C_MASK \
  	((USB_PORT_STAT_C_CONNECTION \
  	| USB_PORT_STAT_C_ENABLE \
  	| USB_PORT_STAT_C_SUSPEND \
  	| USB_PORT_STAT_C_OVERCURRENT \
  	| USB_PORT_STAT_C_RESET) << 16)
  
  static int dummy_hub_status(struct usb_hcd *hcd, char *buf)
  {
  	struct dummy_hcd	*dum_hcd;
  	unsigned long		flags;
  	int			retval = 0;
  
  	dum_hcd = hcd_to_dummy_hcd(hcd);
  
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  	if (!HCD_HW_ACCESSIBLE(hcd))
  		goto done;
  
  	if (dum_hcd->resuming && time_after_eq(jiffies, dum_hcd->re_timeout)) {
  		dum_hcd->port_status |= (USB_PORT_STAT_C_SUSPEND << 16);
  		dum_hcd->port_status &= ~USB_PORT_STAT_SUSPEND;
  		set_link_state(dum_hcd);
  	}
  
  	if ((dum_hcd->port_status & PORT_C_MASK) != 0) {
  		*buf = (1 << 1);
  		dev_dbg(dummy_dev(dum_hcd), "port status 0x%08x has changes\n",
  				dum_hcd->port_status);
  		retval = 1;
  		if (dum_hcd->rh_state == DUMMY_RH_SUSPENDED)
  			usb_hcd_resume_root_hub(hcd);
  	}
  done:
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  	return retval;
  }
  
  /* usb 3.0 root hub device descriptor */
  static struct {
  	struct usb_bos_descriptor bos;
  	struct usb_ss_cap_descriptor ss_cap;
  } __packed usb3_bos_desc = {
  
  	.bos = {
  		.bLength		= USB_DT_BOS_SIZE,
  		.bDescriptorType	= USB_DT_BOS,
  		.wTotalLength		= cpu_to_le16(sizeof(usb3_bos_desc)),
  		.bNumDeviceCaps		= 1,
  	},
  	.ss_cap = {
  		.bLength		= USB_DT_USB_SS_CAP_SIZE,
  		.bDescriptorType	= USB_DT_DEVICE_CAPABILITY,
  		.bDevCapabilityType	= USB_SS_CAP_TYPE,
  		.wSpeedSupported	= cpu_to_le16(USB_5GBPS_OPERATION),
  		.bFunctionalitySupport	= ilog2(USB_5GBPS_OPERATION),
  	},
  };
  
  static inline void
  ss_hub_descriptor(struct usb_hub_descriptor *desc)
  {
  	memset(desc, 0, sizeof *desc);
  	desc->bDescriptorType = USB_DT_SS_HUB;
  	desc->bDescLength = 12;
  	desc->wHubCharacteristics = cpu_to_le16(
  			HUB_CHAR_INDV_PORT_LPSM |
  			HUB_CHAR_COMMON_OCPM);
  	desc->bNbrPorts = 1;
  	desc->u.ss.bHubHdrDecLat = 0x04; /* Worst case: 0.4 micro sec*/
  	desc->u.ss.DeviceRemovable = 0xffff;
  }
  
  static inline void hub_descriptor(struct usb_hub_descriptor *desc)
  {
  	memset(desc, 0, sizeof *desc);
  	desc->bDescriptorType = USB_DT_HUB;
  	desc->bDescLength = 9;
  	desc->wHubCharacteristics = cpu_to_le16(
  			HUB_CHAR_INDV_PORT_LPSM |
  			HUB_CHAR_COMMON_OCPM);
  	desc->bNbrPorts = 1;
  	desc->u.hs.DeviceRemovable[0] = 0xff;
  	desc->u.hs.DeviceRemovable[1] = 0xff;
  }
  
  static int dummy_hub_control(
  	struct usb_hcd	*hcd,
  	u16		typeReq,
  	u16		wValue,
  	u16		wIndex,
  	char		*buf,
  	u16		wLength
  ) {
  	struct dummy_hcd *dum_hcd;
  	int		retval = 0;
  	unsigned long	flags;
  
  	if (!HCD_HW_ACCESSIBLE(hcd))
  		return -ETIMEDOUT;
  
  	dum_hcd = hcd_to_dummy_hcd(hcd);
  
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  	switch (typeReq) {
  	case ClearHubFeature:
  		break;
  	case ClearPortFeature:
  		switch (wValue) {
  		case USB_PORT_FEAT_SUSPEND:
  			if (hcd->speed == HCD_USB3) {
  				dev_dbg(dummy_dev(dum_hcd),
  					 "USB_PORT_FEAT_SUSPEND req not "
  					 "supported for USB 3.0 roothub\n");
  				goto error;
  			}
  			if (dum_hcd->port_status & USB_PORT_STAT_SUSPEND) {
  				/* 20msec resume signaling */
  				dum_hcd->resuming = 1;
  				dum_hcd->re_timeout = jiffies +
  						msecs_to_jiffies(20);
  			}
  			break;
  		case USB_PORT_FEAT_POWER:
  			if (hcd->speed == HCD_USB3) {
  				if (dum_hcd->port_status & USB_PORT_STAT_POWER)
  					dev_dbg(dummy_dev(dum_hcd),
  						"power-off\n");
  			} else
  				if (dum_hcd->port_status &
  							USB_SS_PORT_STAT_POWER)
  					dev_dbg(dummy_dev(dum_hcd),
  						"power-off\n");
  			/* FALLS THROUGH */
  		default:
  			dum_hcd->port_status &= ~(1 << wValue);
  			set_link_state(dum_hcd);
  		}
  		break;
  	case GetHubDescriptor:
  		if (hcd->speed == HCD_USB3 &&
  				(wLength < USB_DT_SS_HUB_SIZE ||
  				 wValue != (USB_DT_SS_HUB << 8))) {
  			dev_dbg(dummy_dev(dum_hcd),
  				"Wrong hub descriptor type for "
  				"USB 3.0 roothub.\n");
  			goto error;
  		}
  		if (hcd->speed == HCD_USB3)
  			ss_hub_descriptor((struct usb_hub_descriptor *) buf);
  		else
  			hub_descriptor((struct usb_hub_descriptor *) buf);
  		break;
  
  	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
  		if (hcd->speed != HCD_USB3)
  			goto error;
  
  		if ((wValue >> 8) != USB_DT_BOS)
  			goto error;
  
  		memcpy(buf, &usb3_bos_desc, sizeof(usb3_bos_desc));
  		retval = sizeof(usb3_bos_desc);
  		break;
  
  	case GetHubStatus:
  		*(__le32 *) buf = cpu_to_le32(0);
  		break;
  	case GetPortStatus:
  		if (wIndex != 1)
  			retval = -EPIPE;
  
  		/* whoever resets or resumes must GetPortStatus to
  		 * complete it!!
  		 */
  		if (dum_hcd->resuming &&
  				time_after_eq(jiffies, dum_hcd->re_timeout)) {
  			dum_hcd->port_status |= (USB_PORT_STAT_C_SUSPEND << 16);
  			dum_hcd->port_status &= ~USB_PORT_STAT_SUSPEND;
  		}
  		if ((dum_hcd->port_status & USB_PORT_STAT_RESET) != 0 &&
  				time_after_eq(jiffies, dum_hcd->re_timeout)) {
  			dum_hcd->port_status |= (USB_PORT_STAT_C_RESET << 16);
  			dum_hcd->port_status &= ~USB_PORT_STAT_RESET;
  			if (dum_hcd->dum->pullup) {
  				dum_hcd->port_status |= USB_PORT_STAT_ENABLE;
  
  				if (hcd->speed < HCD_USB3) {
  					switch (dum_hcd->dum->gadget.speed) {
  					case USB_SPEED_HIGH:
  						dum_hcd->port_status |=
  						      USB_PORT_STAT_HIGH_SPEED;
  						break;
  					case USB_SPEED_LOW:
  						dum_hcd->dum->gadget.ep0->
  							maxpacket = 8;
  						dum_hcd->port_status |=
  							USB_PORT_STAT_LOW_SPEED;
  						break;
  					default:
  						dum_hcd->dum->gadget.speed =
  							USB_SPEED_FULL;
  						break;
  					}
  				}
  			}
  		}
  		set_link_state(dum_hcd);
  		((__le16 *) buf)[0] = cpu_to_le16(dum_hcd->port_status);
  		((__le16 *) buf)[1] = cpu_to_le16(dum_hcd->port_status >> 16);
  		break;
  	case SetHubFeature:
  		retval = -EPIPE;
  		break;
  	case SetPortFeature:
  		switch (wValue) {
  		case USB_PORT_FEAT_LINK_STATE:
  			if (hcd->speed != HCD_USB3) {
  				dev_dbg(dummy_dev(dum_hcd),
  					 "USB_PORT_FEAT_LINK_STATE req not "
  					 "supported for USB 2.0 roothub\n");
  				goto error;
  			}
  			/*
  			 * Since this is dummy we don't have an actual link so
  			 * there is nothing to do for the SET_LINK_STATE cmd
  			 */
  			break;
  		case USB_PORT_FEAT_U1_TIMEOUT:
  		case USB_PORT_FEAT_U2_TIMEOUT:
  			/* TODO: add suspend/resume support! */
  			if (hcd->speed != HCD_USB3) {
  				dev_dbg(dummy_dev(dum_hcd),
  					 "USB_PORT_FEAT_U1/2_TIMEOUT req not "
  					 "supported for USB 2.0 roothub\n");
  				goto error;
  			}
  			break;
  		case USB_PORT_FEAT_SUSPEND:
  			/* Applicable only for USB2.0 hub */
  			if (hcd->speed == HCD_USB3) {
  				dev_dbg(dummy_dev(dum_hcd),
  					 "USB_PORT_FEAT_SUSPEND req not "
  					 "supported for USB 3.0 roothub\n");
  				goto error;
  			}
  			if (dum_hcd->active) {
  				dum_hcd->port_status |= USB_PORT_STAT_SUSPEND;
  
  				/* HNP would happen here; for now we
  				 * assume b_bus_req is always true.
  				 */
  				set_link_state(dum_hcd);
  				if (((1 << USB_DEVICE_B_HNP_ENABLE)
  						& dum_hcd->dum->devstatus) != 0)
  					dev_dbg(dummy_dev(dum_hcd),
  							"no HNP yet!\n");
  			}
  			break;
  		case USB_PORT_FEAT_POWER:
  			if (hcd->speed == HCD_USB3)
  				dum_hcd->port_status |= USB_SS_PORT_STAT_POWER;
  			else
  				dum_hcd->port_status |= USB_PORT_STAT_POWER;
  			set_link_state(dum_hcd);
  			break;
  		case USB_PORT_FEAT_BH_PORT_RESET:
  			/* Applicable only for USB3.0 hub */
  			if (hcd->speed != HCD_USB3) {
  				dev_dbg(dummy_dev(dum_hcd),
  					 "USB_PORT_FEAT_BH_PORT_RESET req not "
  					 "supported for USB 2.0 roothub\n");
  				goto error;
  			}
  			/* FALLS THROUGH */
  		case USB_PORT_FEAT_RESET:
  			/* if it's already enabled, disable */
  			if (hcd->speed == HCD_USB3) {
  				dum_hcd->port_status = 0;
  				dum_hcd->port_status =
  					(USB_SS_PORT_STAT_POWER |
  					 USB_PORT_STAT_CONNECTION |
  					 USB_PORT_STAT_RESET);
  			} else
  				dum_hcd->port_status &= ~(USB_PORT_STAT_ENABLE
  					| USB_PORT_STAT_LOW_SPEED
  					| USB_PORT_STAT_HIGH_SPEED);
  			/*
  			 * We want to reset device status. All but the
  			 * Self powered feature
  			 */
  			dum_hcd->dum->devstatus &=
  				(1 << USB_DEVICE_SELF_POWERED);
  			/*
  			 * FIXME USB3.0: what is the correct reset signaling
  			 * interval? Is it still 50msec as for HS?
  			 */
  			dum_hcd->re_timeout = jiffies + msecs_to_jiffies(50);
  			/* FALLS THROUGH */
  		default:
  			if (hcd->speed == HCD_USB3) {
  				if ((dum_hcd->port_status &
  				     USB_SS_PORT_STAT_POWER) != 0) {
  					dum_hcd->port_status |= (1 << wValue);
  					set_link_state(dum_hcd);
  				}
  			} else
  				if ((dum_hcd->port_status &
  				     USB_PORT_STAT_POWER) != 0) {
  					dum_hcd->port_status |= (1 << wValue);
  					set_link_state(dum_hcd);
  				}
  		}
  		break;
  	case GetPortErrorCount:
  		if (hcd->speed != HCD_USB3) {
  			dev_dbg(dummy_dev(dum_hcd),
  				 "GetPortErrorCount req not "
  				 "supported for USB 2.0 roothub\n");
  			goto error;
  		}
  		/* We'll always return 0 since this is a dummy hub */
  		*(__le32 *) buf = cpu_to_le32(0);
  		break;
  	case SetHubDepth:
  		if (hcd->speed != HCD_USB3) {
  			dev_dbg(dummy_dev(dum_hcd),
  				 "SetHubDepth req not supported for "
  				 "USB 2.0 roothub\n");
  			goto error;
  		}
  		break;
  	default:
  		dev_dbg(dummy_dev(dum_hcd),
  			"hub control req%04x v%04x i%04x l%d\n",
  			typeReq, wValue, wIndex, wLength);
  error:
  		/* "protocol stall" on error */
  		retval = -EPIPE;
  	}
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  
  	if ((dum_hcd->port_status & PORT_C_MASK) != 0)
  		usb_hcd_poll_rh_status(hcd);
  	return retval;
  }
  
  static int dummy_bus_suspend(struct usb_hcd *hcd)
  {
  	struct dummy_hcd *dum_hcd = hcd_to_dummy_hcd(hcd);
  
  	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
  
  	spin_lock_irq(&dum_hcd->dum->lock);
  	dum_hcd->rh_state = DUMMY_RH_SUSPENDED;
  	set_link_state(dum_hcd);
  	hcd->state = HC_STATE_SUSPENDED;
  	spin_unlock_irq(&dum_hcd->dum->lock);
  	return 0;
  }
  
  static int dummy_bus_resume(struct usb_hcd *hcd)
  {
  	struct dummy_hcd *dum_hcd = hcd_to_dummy_hcd(hcd);
  	int rc = 0;
  
  	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
  
  	spin_lock_irq(&dum_hcd->dum->lock);
  	if (!HCD_HW_ACCESSIBLE(hcd)) {
  		rc = -ESHUTDOWN;
  	} else {
  		dum_hcd->rh_state = DUMMY_RH_RUNNING;
  		set_link_state(dum_hcd);
  		if (!list_empty(&dum_hcd->urbp_list))
  			mod_timer(&dum_hcd->timer, jiffies);
  		hcd->state = HC_STATE_RUNNING;
  	}
  	spin_unlock_irq(&dum_hcd->dum->lock);
  	return rc;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static inline ssize_t show_urb(char *buf, size_t size, struct urb *urb)
  {
  	int ep = usb_pipeendpoint(urb->pipe);
  
  	return snprintf(buf, size,
  		"urb/%p %s ep%d%s%s len %d/%d\n",
  		urb,
  		({ char *s;
  		switch (urb->dev->speed) {
  		case USB_SPEED_LOW:
  			s = "ls";
  			break;
  		case USB_SPEED_FULL:
  			s = "fs";
  			break;
  		case USB_SPEED_HIGH:
  			s = "hs";
  			break;
  		case USB_SPEED_SUPER:
  			s = "ss";
  			break;
  		default:
  			s = "?";
  			break;
  		 } s; }),
  		ep, ep ? (usb_pipein(urb->pipe) ? "in" : "out") : "",
  		({ char *s; \
  		switch (usb_pipetype(urb->pipe)) { \
  		case PIPE_CONTROL: \
  			s = ""; \
  			break; \
  		case PIPE_BULK: \
  			s = "-bulk"; \
  			break; \
  		case PIPE_INTERRUPT: \
  			s = "-int"; \
  			break; \
  		default: \
  			s = "-iso"; \
  			break; \
  		} s; }),
  		urb->actual_length, urb->transfer_buffer_length);
  }
  
  static ssize_t urbs_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct usb_hcd		*hcd = dev_get_drvdata(dev);
  	struct dummy_hcd	*dum_hcd = hcd_to_dummy_hcd(hcd);
  	struct urbp		*urbp;
  	size_t			size = 0;
  	unsigned long		flags;
  
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  	list_for_each_entry(urbp, &dum_hcd->urbp_list, urbp_list) {
  		size_t		temp;
  
  		temp = show_urb(buf, PAGE_SIZE - size, urbp->urb);
  		buf += temp;
  		size += temp;
  	}
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  
  	return size;
  }
  static DEVICE_ATTR_RO(urbs);
  
  static int dummy_start_ss(struct dummy_hcd *dum_hcd)
  {
  	init_timer(&dum_hcd->timer);
  	dum_hcd->timer.function = dummy_timer;
  	dum_hcd->timer.data = (unsigned long)dum_hcd;
  	dum_hcd->rh_state = DUMMY_RH_RUNNING;
  	dum_hcd->stream_en_ep = 0;
  	INIT_LIST_HEAD(&dum_hcd->urbp_list);
  	dummy_hcd_to_hcd(dum_hcd)->power_budget = POWER_BUDGET;
  	dummy_hcd_to_hcd(dum_hcd)->state = HC_STATE_RUNNING;
  	dummy_hcd_to_hcd(dum_hcd)->uses_new_polling = 1;
  #ifdef CONFIG_USB_OTG
  	dummy_hcd_to_hcd(dum_hcd)->self.otg_port = 1;
  #endif
  	return 0;
  
  	/* FIXME 'urbs' should be a per-device thing, maybe in usbcore */
  	return device_create_file(dummy_dev(dum_hcd), &dev_attr_urbs);
  }
  
  static int dummy_start(struct usb_hcd *hcd)
  {
  	struct dummy_hcd	*dum_hcd = hcd_to_dummy_hcd(hcd);
  
  	/*
  	 * MASTER side init ... we emulate a root hub that'll only ever
  	 * talk to one device (the slave side).  Also appears in sysfs,
  	 * just like more familiar pci-based HCDs.
  	 */
  	if (!usb_hcd_is_primary_hcd(hcd))
  		return dummy_start_ss(dum_hcd);
  
  	spin_lock_init(&dum_hcd->dum->lock);
  	init_timer(&dum_hcd->timer);
  	dum_hcd->timer.function = dummy_timer;
  	dum_hcd->timer.data = (unsigned long)dum_hcd;
  	dum_hcd->rh_state = DUMMY_RH_RUNNING;
  
  	INIT_LIST_HEAD(&dum_hcd->urbp_list);
  
  	hcd->power_budget = POWER_BUDGET;
  	hcd->state = HC_STATE_RUNNING;
  	hcd->uses_new_polling = 1;
  
  #ifdef CONFIG_USB_OTG
  	hcd->self.otg_port = 1;
  #endif
  
  	/* FIXME 'urbs' should be a per-device thing, maybe in usbcore */
  	return device_create_file(dummy_dev(dum_hcd), &dev_attr_urbs);
  }
  
  static void dummy_stop(struct usb_hcd *hcd)
  {
  	device_remove_file(dummy_dev(hcd_to_dummy_hcd(hcd)), &dev_attr_urbs);
  	dev_info(dummy_dev(hcd_to_dummy_hcd(hcd)), "stopped\n");
  }
  
  /*-------------------------------------------------------------------------*/
  
  static int dummy_h_get_frame(struct usb_hcd *hcd)
  {
  	return dummy_g_get_frame(NULL);
  }
  
  static int dummy_setup(struct usb_hcd *hcd)
  {
  	struct dummy *dum;
  
  	dum = *((void **)dev_get_platdata(hcd->self.controller));
  	hcd->self.sg_tablesize = ~0;
  	if (usb_hcd_is_primary_hcd(hcd)) {
  		dum->hs_hcd = hcd_to_dummy_hcd(hcd);
  		dum->hs_hcd->dum = dum;
  		/*
  		 * Mark the first roothub as being USB 2.0.
  		 * The USB 3.0 roothub will be registered later by
  		 * dummy_hcd_probe()
  		 */
  		hcd->speed = HCD_USB2;
  		hcd->self.root_hub->speed = USB_SPEED_HIGH;
  	} else {
  		dum->ss_hcd = hcd_to_dummy_hcd(hcd);
  		dum->ss_hcd->dum = dum;
  		hcd->speed = HCD_USB3;
  		hcd->self.root_hub->speed = USB_SPEED_SUPER;
  	}
  	return 0;
  }
  
  /* Change a group of bulk endpoints to support multiple stream IDs */
  static int dummy_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev,
  	struct usb_host_endpoint **eps, unsigned int num_eps,
  	unsigned int num_streams, gfp_t mem_flags)
  {
  	struct dummy_hcd *dum_hcd = hcd_to_dummy_hcd(hcd);
  	unsigned long flags;
  	int max_stream;
  	int ret_streams = num_streams;
  	unsigned int index;
  	unsigned int i;
  
  	if (!num_eps)
  		return -EINVAL;
  
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  	for (i = 0; i < num_eps; i++) {
  		index = dummy_get_ep_idx(&eps[i]->desc);
  		if ((1 << index) & dum_hcd->stream_en_ep) {
  			ret_streams = -EINVAL;
  			goto out;
  		}
  		max_stream = usb_ss_max_streams(&eps[i]->ss_ep_comp);
  		if (!max_stream) {
  			ret_streams = -EINVAL;
  			goto out;
  		}
  		if (max_stream < ret_streams) {
  			dev_dbg(dummy_dev(dum_hcd), "Ep 0x%x only supports %u "
  					"stream IDs.\n",
  					eps[i]->desc.bEndpointAddress,
  					max_stream);
  			ret_streams = max_stream;
  		}
  	}
  
  	for (i = 0; i < num_eps; i++) {
  		index = dummy_get_ep_idx(&eps[i]->desc);
  		dum_hcd->stream_en_ep |= 1 << index;
  		set_max_streams_for_pipe(dum_hcd,
  				usb_endpoint_num(&eps[i]->desc), ret_streams);
  	}
  out:
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  	return ret_streams;
  }
  
  /* Reverts a group of bulk endpoints back to not using stream IDs. */
  static int dummy_free_streams(struct usb_hcd *hcd, struct usb_device *udev,
  	struct usb_host_endpoint **eps, unsigned int num_eps,
  	gfp_t mem_flags)
  {
  	struct dummy_hcd *dum_hcd = hcd_to_dummy_hcd(hcd);
  	unsigned long flags;
  	int ret;
  	unsigned int index;
  	unsigned int i;
  
  	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
  	for (i = 0; i < num_eps; i++) {
  		index = dummy_get_ep_idx(&eps[i]->desc);
  		if (!((1 << index) & dum_hcd->stream_en_ep)) {
  			ret = -EINVAL;
  			goto out;
  		}
  	}
  
  	for (i = 0; i < num_eps; i++) {
  		index = dummy_get_ep_idx(&eps[i]->desc);
  		dum_hcd->stream_en_ep &= ~(1 << index);
  		set_max_streams_for_pipe(dum_hcd,
  				usb_endpoint_num(&eps[i]->desc), 0);
  	}
  	ret = 0;
  out:
  	spin_unlock_irqrestore(&dum_hcd->dum->lock, flags);
  	return ret;
  }
  
  static struct hc_driver dummy_hcd = {
  	.description =		(char *) driver_name,
  	.product_desc =		"Dummy host controller",
  	.hcd_priv_size =	sizeof(struct dummy_hcd),
  
  	.flags =		HCD_USB3 | HCD_SHARED,
  
  	.reset =		dummy_setup,
  	.start =		dummy_start,
  	.stop =			dummy_stop,
  
  	.urb_enqueue =		dummy_urb_enqueue,
  	.urb_dequeue =		dummy_urb_dequeue,
  
  	.get_frame_number =	dummy_h_get_frame,
  
  	.hub_status_data =	dummy_hub_status,
  	.hub_control =		dummy_hub_control,
  	.bus_suspend =		dummy_bus_suspend,
  	.bus_resume =		dummy_bus_resume,
  
  	.alloc_streams =	dummy_alloc_streams,
  	.free_streams =		dummy_free_streams,
  };
  
  static int dummy_hcd_probe(struct platform_device *pdev)
  {
  	struct dummy		*dum;
  	struct usb_hcd		*hs_hcd;
  	struct usb_hcd		*ss_hcd;
  	int			retval;
  
  	dev_info(&pdev->dev, "%s, driver " DRIVER_VERSION "\n", driver_desc);
  	dum = *((void **)dev_get_platdata(&pdev->dev));
  
  	if (!mod_data.is_super_speed)
  		dummy_hcd.flags = HCD_USB2;
  	hs_hcd = usb_create_hcd(&dummy_hcd, &pdev->dev, dev_name(&pdev->dev));
  	if (!hs_hcd)
  		return -ENOMEM;
  	hs_hcd->has_tt = 1;
  
  	retval = usb_add_hcd(hs_hcd, 0, 0);
  	if (retval)
  		goto put_usb2_hcd;
  
  	if (mod_data.is_super_speed) {
  		ss_hcd = usb_create_shared_hcd(&dummy_hcd, &pdev->dev,
  					dev_name(&pdev->dev), hs_hcd);
  		if (!ss_hcd) {
  			retval = -ENOMEM;
  			goto dealloc_usb2_hcd;
  		}
  
  		retval = usb_add_hcd(ss_hcd, 0, 0);
  		if (retval)
  			goto put_usb3_hcd;
  	}
  	return 0;
  
  put_usb3_hcd:
  	usb_put_hcd(ss_hcd);
  dealloc_usb2_hcd:
  	usb_remove_hcd(hs_hcd);
  put_usb2_hcd:
  	usb_put_hcd(hs_hcd);
  	dum->hs_hcd = dum->ss_hcd = NULL;
  	return retval;
  }
  
  static int dummy_hcd_remove(struct platform_device *pdev)
  {
  	struct dummy		*dum;
  
  	dum = hcd_to_dummy_hcd(platform_get_drvdata(pdev))->dum;
  
  	if (dum->ss_hcd) {
  		usb_remove_hcd(dummy_hcd_to_hcd(dum->ss_hcd));
  		usb_put_hcd(dummy_hcd_to_hcd(dum->ss_hcd));
  	}
  
  	usb_remove_hcd(dummy_hcd_to_hcd(dum->hs_hcd));
  	usb_put_hcd(dummy_hcd_to_hcd(dum->hs_hcd));
  
  	dum->hs_hcd = NULL;
  	dum->ss_hcd = NULL;
  
  	return 0;
  }
  
  static int dummy_hcd_suspend(struct platform_device *pdev, pm_message_t state)
  {
  	struct usb_hcd		*hcd;
  	struct dummy_hcd	*dum_hcd;
  	int			rc = 0;
  
  	dev_dbg(&pdev->dev, "%s\n", __func__);
  
  	hcd = platform_get_drvdata(pdev);
  	dum_hcd = hcd_to_dummy_hcd(hcd);
  	if (dum_hcd->rh_state == DUMMY_RH_RUNNING) {
  		dev_warn(&pdev->dev, "Root hub isn't suspended!\n");
  		rc = -EBUSY;
  	} else
  		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
  	return rc;
  }
  
  static int dummy_hcd_resume(struct platform_device *pdev)
  {
  	struct usb_hcd		*hcd;
  
  	dev_dbg(&pdev->dev, "%s\n", __func__);
  
  	hcd = platform_get_drvdata(pdev);
  	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
  	usb_hcd_poll_rh_status(hcd);
  	return 0;
  }
  
  static struct platform_driver dummy_hcd_driver = {
  	.probe		= dummy_hcd_probe,
  	.remove		= dummy_hcd_remove,
  	.suspend	= dummy_hcd_suspend,
  	.resume		= dummy_hcd_resume,
  	.driver		= {
  		.name	= (char *) driver_name,
  	},
  };
  
  /*-------------------------------------------------------------------------*/
  #define MAX_NUM_UDC	2
  static struct platform_device *the_udc_pdev[MAX_NUM_UDC];
  static struct platform_device *the_hcd_pdev[MAX_NUM_UDC];
  
  static int __init init(void)
  {
  	int	retval = -ENOMEM;
  	int	i;
  	struct	dummy *dum[MAX_NUM_UDC];
  
  	if (usb_disabled())
  		return -ENODEV;
  
  	if (!mod_data.is_high_speed && mod_data.is_super_speed)
  		return -EINVAL;
  
  	if (mod_data.num < 1 || mod_data.num > MAX_NUM_UDC) {
  		pr_err("Number of emulated UDC must be in range of 1...%d\n",
  				MAX_NUM_UDC);
  		return -EINVAL;
  	}
  
  	for (i = 0; i < mod_data.num; i++) {
  		the_hcd_pdev[i] = platform_device_alloc(driver_name, i);
  		if (!the_hcd_pdev[i]) {
  			i--;
  			while (i >= 0)
  				platform_device_put(the_hcd_pdev[i--]);
  			return retval;
  		}
  	}
  	for (i = 0; i < mod_data.num; i++) {
  		the_udc_pdev[i] = platform_device_alloc(gadget_name, i);
  		if (!the_udc_pdev[i]) {
  			i--;
  			while (i >= 0)
  				platform_device_put(the_udc_pdev[i--]);
  			goto err_alloc_udc;
  		}
  	}
  	for (i = 0; i < mod_data.num; i++) {
  		dum[i] = kzalloc(sizeof(struct dummy), GFP_KERNEL);
  		if (!dum[i]) {
  			retval = -ENOMEM;
  			goto err_add_pdata;
  		}
  		retval = platform_device_add_data(the_hcd_pdev[i], &dum[i],
  				sizeof(void *));
  		if (retval)
  			goto err_add_pdata;
  		retval = platform_device_add_data(the_udc_pdev[i], &dum[i],
  				sizeof(void *));
  		if (retval)
  			goto err_add_pdata;
  	}
  
  	retval = platform_driver_register(&dummy_hcd_driver);
  	if (retval < 0)
  		goto err_add_pdata;
  	retval = platform_driver_register(&dummy_udc_driver);
  	if (retval < 0)
  		goto err_register_udc_driver;
  
  	for (i = 0; i < mod_data.num; i++) {
  		retval = platform_device_add(the_hcd_pdev[i]);
  		if (retval < 0) {
  			i--;
  			while (i >= 0)
  				platform_device_del(the_hcd_pdev[i--]);
  			goto err_add_hcd;
  		}
  	}
  	for (i = 0; i < mod_data.num; i++) {
  		if (!dum[i]->hs_hcd ||
  				(!dum[i]->ss_hcd && mod_data.is_super_speed)) {
  			/*
  			 * The hcd was added successfully but its probe
  			 * function failed for some reason.
  			 */
  			retval = -EINVAL;
  			goto err_add_udc;
  		}
  	}
  
  	for (i = 0; i < mod_data.num; i++) {
  		retval = platform_device_add(the_udc_pdev[i]);
  		if (retval < 0) {
  			i--;
  			while (i >= 0)
  				platform_device_del(the_udc_pdev[i]);
  			goto err_add_udc;
  		}
  	}
  
  	for (i = 0; i < mod_data.num; i++) {
  		if (!platform_get_drvdata(the_udc_pdev[i])) {
  			/*
  			 * The udc was added successfully but its probe
  			 * function failed for some reason.
  			 */
  			retval = -EINVAL;
  			goto err_probe_udc;
  		}
  	}
  	return retval;
  
  err_probe_udc:
  	for (i = 0; i < mod_data.num; i++)
  		platform_device_del(the_udc_pdev[i]);
  err_add_udc:
  	for (i = 0; i < mod_data.num; i++)
  		platform_device_del(the_hcd_pdev[i]);
  err_add_hcd:
  	platform_driver_unregister(&dummy_udc_driver);
  err_register_udc_driver:
  	platform_driver_unregister(&dummy_hcd_driver);
  err_add_pdata:
  	for (i = 0; i < mod_data.num; i++)
  		kfree(dum[i]);
  	for (i = 0; i < mod_data.num; i++)
  		platform_device_put(the_udc_pdev[i]);
  err_alloc_udc:
  	for (i = 0; i < mod_data.num; i++)
  		platform_device_put(the_hcd_pdev[i]);
  	return retval;
  }
  module_init(init);
  
  static void __exit cleanup(void)
  {
  	int i;
  
  	for (i = 0; i < mod_data.num; i++) {
  		struct dummy *dum;
  
  		dum = *((void **)dev_get_platdata(&the_udc_pdev[i]->dev));
  
  		platform_device_unregister(the_udc_pdev[i]);
  		platform_device_unregister(the_hcd_pdev[i]);
  		kfree(dum);
  	}
  	platform_driver_unregister(&dummy_udc_driver);
  	platform_driver_unregister(&dummy_hcd_driver);
  }
  module_exit(cleanup);
  