Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2909 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
new file mode 100644
index 000000000..899ac9f9c
--- /dev/null
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -0,0 +1,2909 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 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 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 (device);
+ *  - 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.
+ *
+ * Note: The emulation does not include isochronous transfers!
+ */
+
+#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 */
+#define POWER_BUDGET_3	900	/* in mA */
+
+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, \
+	}
+
+/* we don't provide isochronous endpoints since we don't support them */
+#define TYPE_BULK_OR_INT	(USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
+
+	/* 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("ep-aout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-bin",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
+	EP_INFO("ep-cout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-dout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-ein",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
+	EP_INFO("ep-fout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-gin",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
+	EP_INFO("ep-hout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-iout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-jin",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
+	EP_INFO("ep-kout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
+	EP_INFO("ep-lin",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
+	EP_INFO("ep-mout",
+		USB_EP_CAPS(TYPE_BULK_OR_INT, 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;
+	struct urbp			*next_frame_urbp;
+
+	u32				stream_en_ep;
+	u8				num_stream[30 / 2];
+
+	unsigned			active:1;
+	unsigned			old_active:1;
+	unsigned			resuming:1;
+};
+
+struct dummy {
+	spinlock_t			lock;
+
+	/*
+	 * DEVICE/GADGET side support
+	 */
+	struct dummy_ep			ep[DUMMY_ENDPOINTS];
+	int				address;
+	int				callback_usage;
+	struct usb_gadget		gadget;
+	struct usb_gadget_driver	*driver;
+	struct dummy_request		fifo_req;
+	u8				fifo_buf[FIFO_SIZE];
+	u16				devstatus;
+	unsigned			ints_enabled:1;
+	unsigned			udc_suspended:1;
+	unsigned			pullup:1;
+
+	/*
+	 * 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);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* DEVICE/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) &&
+			    (dum_hcd->port_status &
+			     USB_PORT_STAT_LINK_STATE) == USB_SS_PORT_LS_U0 &&
+			    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)
+	__must_hold(&dum->lock)
+{
+	struct dummy *dum = dum_hcd->dum;
+	unsigned int power_bit;
+
+	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);
+	power_bit = (dummy_hcd_to_hcd(dum_hcd)->speed == HCD_USB3 ?
+			USB_SS_PORT_STAT_POWER : USB_PORT_STAT_POWER);
+
+	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 & power_bit) == 0 ||
+			(dum_hcd->port_status & USB_PORT_STAT_RESET) != 0) {
+		unsigned int disconnect = power_bit &
+				dum_hcd->old_status & (~dum_hcd->port_status);
+		unsigned int reset = USB_PORT_STAT_RESET &
+				(~dum_hcd->old_status) & dum_hcd->port_status;
+
+		/* Report reset and disconnect events to the driver */
+		if (dum->ints_enabled && (disconnect || reset)) {
+			stop_activity(dum);
+			++dum->callback_usage;
+			spin_unlock(&dum->lock);
+			if (reset)
+				usb_gadget_udc_reset(&dum->gadget, dum->driver);
+			else
+				dum->driver->disconnect(&dum->gadget);
+			spin_lock(&dum->lock);
+			--dum->callback_usage;
+		}
+	} else if (dum_hcd->active != dum_hcd->old_active &&
+			dum->ints_enabled) {
+		++dum->callback_usage;
+		spin_unlock(&dum->lock);
+		if (dum_hcd->old_active && dum->driver->suspend)
+			dum->driver->suspend(&dum->gadget);
+		else if (!dum_hcd->old_active &&  dum->driver->resume)
+			dum->driver->resume(&dum->gadget);
+		spin_lock(&dum->lock);
+		--dum->callback_usage;
+	}
+
+	dum_hcd->old_status = dum_hcd->port_status;
+	dum_hcd->old_active = dum_hcd->active;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* DEVICE/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);
+
+	/* 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 */
+			fallthrough;
+		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 */
+			fallthrough;
+		case USB_SPEED_FULL:
+			if (max <= 64)
+				break;
+			/* save a return statement */
+			fallthrough;
+		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 */
+			fallthrough;
+		case USB_SPEED_FULL:
+			if (max <= 1023)
+				break;
+			/* save a return statement */
+			fallthrough;
+		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",
+		usb_ep_type_string(usb_endpoint_type(desc)),
+		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, *iter;
+
+	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(iter, &ep->queue, queue) {
+		if (&iter->req != _req)
+			continue;
+		list_del_init(&iter->queue);
+		_req->status = -ECONNRESET;
+		req = iter;
+		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);
+	dum_hcd = gadget_to_dummy_hcd(_gadget);
+
+	spin_lock_irqsave(&dum->lock, flags);
+	dum->pullup = (value != 0);
+	set_link_state(dum_hcd);
+	if (value == 0) {
+		/*
+		 * Emulate synchronize_irq(): wait for callbacks to finish.
+		 * This seems to be the best place to emulate the call to
+		 * synchronize_irq() that's in usb_gadget_remove_driver().
+		 * Doing it in dummy_udc_stop() would be too late since it
+		 * is called after the unbind callback and unbind shouldn't
+		 * be invoked until all the other callbacks are finished.
+		 */
+		while (dum->callback_usage > 0) {
+			spin_unlock_irqrestore(&dum->lock, flags);
+			usleep_range(1000, 2000);
+			spin_lock_irqsave(&dum->lock, flags);
+		}
+	}
+	spin_unlock_irqrestore(&dum->lock, flags);
+
+	usb_hcd_poll_rh_status(dummy_hcd_to_hcd(dum_hcd));
+	return 0;
+}
+
+static void dummy_udc_set_speed(struct usb_gadget *_gadget,
+		enum usb_device_speed speed)
+{
+	struct dummy	*dum;
+
+	dum = gadget_dev_to_dummy(&_gadget->dev);
+	dum->gadget.speed = speed;
+	dummy_udc_update_ep0(dum);
+}
+
+static void dummy_udc_async_callbacks(struct usb_gadget *_gadget, bool enable)
+{
+	struct dummy	*dum = gadget_dev_to_dummy(&_gadget->dev);
+
+	spin_lock_irq(&dum->lock);
+	dum->ints_enabled = enable;
+	spin_unlock_irq(&dum->lock);
+}
+
+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,
+	.udc_set_speed	= dummy_udc_set_speed,
+	.udc_async_callbacks = dummy_udc_async_callbacks,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/* "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 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;
+
+	switch (g->speed) {
+	/* All the speeds we support */
+	case USB_SPEED_LOW:
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+	case USB_SPEED_SUPER:
+		break;
+	default:
+		dev_err(dummy_dev(dum_hcd), "Unsupported driver max speed %d\n",
+				driver->max_speed);
+		return -EINVAL;
+	}
+
+	/*
+	 * DEVICE side init ... the layer above hardware, which
+	 * can't enumerate without help from the driver we're binding.
+	 */
+
+	spin_lock_irq(&dum->lock);
+	dum->devstatus = 0;
+	dum->driver = driver;
+	spin_unlock_irq(&dum->lock);
+
+	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;
+
+	spin_lock_irq(&dum->lock);
+	dum->ints_enabled = 0;
+	stop_activity(dum);
+	dum->driver = NULL;
+	spin_unlock_irq(&dum->lock);
+
+	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));
+	/* Clear usb_gadget region for new registration to udc-core */
+	memzero_explicit(&dum->gadget, sizeof(struct usb_gadget));
+	dum->gadget.name = gadget_name;
+	dum->gadget.ops = &dummy_ops;
+	if (mod_data.is_super_speed)
+		dum->gadget.max_speed = USB_SPEED_SUPER;
+	else if (mod_data.is_high_speed)
+		dum->gadget.max_speed = USB_SPEED_HIGH;
+	else
+		dum->gadget.max_speed = USB_SPEED_FULL;
+
+	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	= 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;
+}
+
+/* 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 (!dum_hcd->next_frame_urbp)
+		dum_hcd->next_frame_urbp = 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_urb_dir_in(urb);
+	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_urb_dir_in(urb);
+		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_mult(ep->desc);
+		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 (!dum->ints_enabled)
+		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_hcd: 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 that the callbacks are invoked from soft interrupt
+ * context.
+ */
+static void dummy_timer(struct timer_list *t)
+{
+	struct dummy_hcd	*dum_hcd = from_timer(dum_hcd, t, timer);
+	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 */
+	/* FIXME: account for transaction and packet overhead */
+	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:	/* Can't happen */
+		dev_err(dummy_dev(dum_hcd), "bogus device speed\n");
+		total = 0;
+		break;
+	}
+
+	/* 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;
+	}
+	dum_hcd->next_frame_urbp = NULL;
+
+	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			status = -EINPROGRESS;
+
+		/* stop when we reach URBs queued after the timer interrupt */
+		if (urbp == dum_hcd->next_frame_urbp)
+			break;
+
+		urb = urbp->urb;
+		if (urb->unlinked)
+			goto return_urb;
+		else if (dum_hcd->rh_state != DUMMY_RH_RUNNING)
+			continue;
+
+		/* Used up this frame's bandwidth? */
+		if (total <= 0)
+			continue;
+
+		/* find the gadget's ep for this request (if configured) */
+		address = usb_pipeendpoint (urb->pipe);
+		if (usb_urb_dir_in(urb))
+			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;
+
+			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) {
+				++dum->callback_usage;
+				spin_unlock(&dum->lock);
+				value = dum->driver->setup(&dum->gadget,
+						&setup);
+				spin_lock(&dum->lock);
+				--dum->callback_usage;
+
+				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:
+			/*
+			 * We don't support isochronous.  But if we did,
+			 * here are some of the issues we'd have to face:
+			 *
+			 * 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 = -EINVAL;	/* fail all xfers */
+			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 = 0;
+}
+
+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] = 0;
+	desc->u.hs.DeviceRemovable[1] = 0xff;	/* PortPwrCtrlMask */
+}
+
+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:
+			dev_dbg(dummy_dev(dum_hcd), "power-off\n");
+			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_ENABLE:
+		case USB_PORT_FEAT_C_ENABLE:
+		case USB_PORT_FEAT_C_SUSPEND:
+			/* Not allowed for USB-3 */
+			if (hcd->speed == HCD_USB3)
+				goto error;
+			fallthrough;
+		case USB_PORT_FEAT_C_CONNECTION:
+		case USB_PORT_FEAT_C_RESET:
+			dum_hcd->port_status &= ~(1 << wValue);
+			set_link_state(dum_hcd);
+			break;
+		default:
+		/* Disallow INDICATOR and C_OVER_CURRENT */
+			goto error;
+		}
+		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:
+						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;
+			}
+			fallthrough;
+		case USB_PORT_FEAT_RESET:
+			if (!(dum_hcd->port_status & USB_PORT_STAT_CONNECTION))
+				break;
+			/* if it's already enabled, disable */
+			if (hcd->speed == HCD_USB3) {
+				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);
+				dum_hcd->port_status |= USB_PORT_STAT_RESET;
+			}
+			/*
+			 * 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);
+			set_link_state(dum_hcd);
+			break;
+		case USB_PORT_FEAT_C_CONNECTION:
+		case USB_PORT_FEAT_C_RESET:
+		case USB_PORT_FEAT_C_ENABLE:
+		case USB_PORT_FEAT_C_SUSPEND:
+			/* Not allowed for USB-3, and ignored for USB-2 */
+			if (hcd->speed == HCD_USB3)
+				goto error;
+			break;
+		default:
+		/* Disallow TEST, INDICATOR, and C_OVER_CURRENT */
+			goto error;
+		}
+		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 scnprintf(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_urb_dir_in(urb) ? "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)
+{
+	timer_setup(&dum_hcd->timer, dummy_timer, 0);
+	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_3;
+	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);
+
+	/*
+	 * HOST side init ... we emulate a root hub that'll only ever
+	 * talk to one device (the gadget 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);
+	timer_setup(&dum_hcd->timer, dummy_timer, 0);
+	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),
+
+	.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_USB3 | HCD_SHARED;
+	else if (mod_data.is_high_speed)
+		dummy_hcd.flags = HCD_USB2;
+	else
+		dummy_hcd.flags = HCD_USB11;
+	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	= driver_name,
+	},
+};
+
+/*-------------------------------------------------------------------------*/
+#define MAX_NUM_UDC	32
+static struct platform_device *the_udc_pdev[MAX_NUM_UDC];
+static struct platform_device *the_hcd_pdev[MAX_NUM_UDC];
+
+static int __init dummy_hcd_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(dummy_hcd_init);
+
+static void __exit dummy_hcd_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(dummy_hcd_cleanup);