usb: gadget: Gadget directory cleanup - group usb functions

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 0 insertions, 3347 deletions

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
deleted file mode 100644
index fe45060e0a7a..000000000000
--- a/drivers/usb/gadget/f_fs.c
+++ /dev/null
@@ -1,3347 +0,0 @@
-/*
- * f_fs.c -- user mode file system API for USB composite function controllers
- *
- * Copyright (C) 2010 Samsung Electronics
- * Author: Michal Nazarewicz <mina86@mina86.com>
- *
- * Based on inode.c (GadgetFS) which was:
- * Copyright (C) 2003-2004 David Brownell
- * Copyright (C) 2003 Agilent Technologies
- *
- * 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.
- */
-
-
-/* #define DEBUG */
-/* #define VERBOSE_DEBUG */
-
-#include <linux/blkdev.h>
-#include <linux/pagemap.h>
-#include <linux/export.h>
-#include <linux/hid.h>
-#include <linux/module.h>
-#include <asm/unaligned.h>
-
-#include <linux/usb/composite.h>
-#include <linux/usb/functionfs.h>
-
-#include <linux/aio.h>
-#include <linux/mmu_context.h>
-#include <linux/poll.h>
-
-#include "u_fs.h"
-#include "u_f.h"
-#include "u_os_desc.h"
-#include "configfs.h"
-
-#define FUNCTIONFS_MAGIC	0xa647361 /* Chosen by a honest dice roll ;) */
-
-/* Reference counter handling */
-static void ffs_data_get(struct ffs_data *ffs);
-static void ffs_data_put(struct ffs_data *ffs);
-/* Creates new ffs_data object. */
-static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
-
-/* Opened counter handling. */
-static void ffs_data_opened(struct ffs_data *ffs);
-static void ffs_data_closed(struct ffs_data *ffs);
-
-/* Called with ffs->mutex held; take over ownership of data. */
-static int __must_check
-__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
-static int __must_check
-__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
-
-
-/* The function structure ***************************************************/
-
-struct ffs_ep;
-
-struct ffs_function {
-	struct usb_configuration	*conf;
-	struct usb_gadget		*gadget;
-	struct ffs_data			*ffs;
-
-	struct ffs_ep			*eps;
-	u8				eps_revmap[16];
-	short				*interfaces_nums;
-
-	struct usb_function		function;
-};
-
-
-static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
-{
-	return container_of(f, struct ffs_function, function);
-}
-
-
-static inline enum ffs_setup_state
-ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
-{
-	return (enum ffs_setup_state)
-		cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
-}
-
-
-static void ffs_func_eps_disable(struct ffs_function *func);
-static int __must_check ffs_func_eps_enable(struct ffs_function *func);
-
-static int ffs_func_bind(struct usb_configuration *,
-			 struct usb_function *);
-static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
-static void ffs_func_disable(struct usb_function *);
-static int ffs_func_setup(struct usb_function *,
-			  const struct usb_ctrlrequest *);
-static void ffs_func_suspend(struct usb_function *);
-static void ffs_func_resume(struct usb_function *);
-
-
-static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
-static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
-
-
-/* The endpoints structures *************************************************/
-
-struct ffs_ep {
-	struct usb_ep			*ep;	/* P: ffs->eps_lock */
-	struct usb_request		*req;	/* P: epfile->mutex */
-
-	/* [0]: full speed, [1]: high speed, [2]: super speed */
-	struct usb_endpoint_descriptor	*descs[3];
-
-	u8				num;
-
-	int				status;	/* P: epfile->mutex */
-};
-
-struct ffs_epfile {
-	/* Protects ep->ep and ep->req. */
-	struct mutex			mutex;
-	wait_queue_head_t		wait;
-
-	struct ffs_data			*ffs;
-	struct ffs_ep			*ep;	/* P: ffs->eps_lock */
-
-	struct dentry			*dentry;
-
-	char				name[5];
-
-	unsigned char			in;	/* P: ffs->eps_lock */
-	unsigned char			isoc;	/* P: ffs->eps_lock */
-
-	unsigned char			_pad;
-};
-
-/*  ffs_io_data structure ***************************************************/
-
-struct ffs_io_data {
-	bool aio;
-	bool read;
-
-	struct kiocb *kiocb;
-	const struct iovec *iovec;
-	unsigned long nr_segs;
-	char __user *buf;
-	size_t len;
-
-	struct mm_struct *mm;
-	struct work_struct work;
-
-	struct usb_ep *ep;
-	struct usb_request *req;
-};
-
-static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
-static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
-
-static struct inode *__must_check
-ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
-		   const struct file_operations *fops,
-		   struct dentry **dentry_p);
-
-/* Devices management *******************************************************/
-
-DEFINE_MUTEX(ffs_lock);
-EXPORT_SYMBOL_GPL(ffs_lock);
-
-static struct ffs_dev *_ffs_find_dev(const char *name);
-static struct ffs_dev *_ffs_alloc_dev(void);
-static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
-static void _ffs_free_dev(struct ffs_dev *dev);
-static void *ffs_acquire_dev(const char *dev_name);
-static void ffs_release_dev(struct ffs_data *ffs_data);
-static int ffs_ready(struct ffs_data *ffs);
-static void ffs_closed(struct ffs_data *ffs);
-
-/* Misc helper functions ****************************************************/
-
-static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
-	__attribute__((warn_unused_result, nonnull));
-static char *ffs_prepare_buffer(const char __user *buf, size_t len)
-	__attribute__((warn_unused_result, nonnull));
-
-
-/* Control file aka ep0 *****************************************************/
-
-static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
-{
-	struct ffs_data *ffs = req->context;
-
-	complete_all(&ffs->ep0req_completion);
-}
-
-static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
-{
-	struct usb_request *req = ffs->ep0req;
-	int ret;
-
-	req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
-
-	spin_unlock_irq(&ffs->ev.waitq.lock);
-
-	req->buf      = data;
-	req->length   = len;
-
-	/*
-	 * UDC layer requires to provide a buffer even for ZLP, but should
-	 * not use it at all. Let's provide some poisoned pointer to catch
-	 * possible bug in the driver.
-	 */
-	if (req->buf == NULL)
-		req->buf = (void *)0xDEADBABE;
-
-	reinit_completion(&ffs->ep0req_completion);
-
-	ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
-	if (unlikely(ret < 0))
-		return ret;
-
-	ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
-	if (unlikely(ret)) {
-		usb_ep_dequeue(ffs->gadget->ep0, req);
-		return -EINTR;
-	}
-
-	ffs->setup_state = FFS_NO_SETUP;
-	return req->status ? req->status : req->actual;
-}
-
-static int __ffs_ep0_stall(struct ffs_data *ffs)
-{
-	if (ffs->ev.can_stall) {
-		pr_vdebug("ep0 stall\n");
-		usb_ep_set_halt(ffs->gadget->ep0);
-		ffs->setup_state = FFS_NO_SETUP;
-		return -EL2HLT;
-	} else {
-		pr_debug("bogus ep0 stall!\n");
-		return -ESRCH;
-	}
-}
-
-static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
-			     size_t len, loff_t *ptr)
-{
-	struct ffs_data *ffs = file->private_data;
-	ssize_t ret;
-	char *data;
-
-	ENTER();
-
-	/* Fast check if setup was canceled */
-	if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
-		return -EIDRM;
-
-	/* Acquire mutex */
-	ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
-	if (unlikely(ret < 0))
-		return ret;
-
-	/* Check state */
-	switch (ffs->state) {
-	case FFS_READ_DESCRIPTORS:
-	case FFS_READ_STRINGS:
-		/* Copy data */
-		if (unlikely(len < 16)) {
-			ret = -EINVAL;
-			break;
-		}
-
-		data = ffs_prepare_buffer(buf, len);
-		if (IS_ERR(data)) {
-			ret = PTR_ERR(data);
-			break;
-		}
-
-		/* Handle data */
-		if (ffs->state == FFS_READ_DESCRIPTORS) {
-			pr_info("read descriptors\n");
-			ret = __ffs_data_got_descs(ffs, data, len);
-			if (unlikely(ret < 0))
-				break;
-
-			ffs->state = FFS_READ_STRINGS;
-			ret = len;
-		} else {
-			pr_info("read strings\n");
-			ret = __ffs_data_got_strings(ffs, data, len);
-			if (unlikely(ret < 0))
-				break;
-
-			ret = ffs_epfiles_create(ffs);
-			if (unlikely(ret)) {
-				ffs->state = FFS_CLOSING;
-				break;
-			}
-
-			ffs->state = FFS_ACTIVE;
-			mutex_unlock(&ffs->mutex);
-
-			ret = ffs_ready(ffs);
-			if (unlikely(ret < 0)) {
-				ffs->state = FFS_CLOSING;
-				return ret;
-			}
-
-			set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
-			return len;
-		}
-		break;
-
-	case FFS_ACTIVE:
-		data = NULL;
-		/*
-		 * We're called from user space, we can use _irq
-		 * rather then _irqsave
-		 */
-		spin_lock_irq(&ffs->ev.waitq.lock);
-		switch (ffs_setup_state_clear_cancelled(ffs)) {
-		case FFS_SETUP_CANCELLED:
-			ret = -EIDRM;
-			goto done_spin;
-
-		case FFS_NO_SETUP:
-			ret = -ESRCH;
-			goto done_spin;
-
-		case FFS_SETUP_PENDING:
-			break;
-		}
-
-		/* FFS_SETUP_PENDING */
-		if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
-			spin_unlock_irq(&ffs->ev.waitq.lock);
-			ret = __ffs_ep0_stall(ffs);
-			break;
-		}
-
-		/* FFS_SETUP_PENDING and not stall */
-		len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
-
-		spin_unlock_irq(&ffs->ev.waitq.lock);
-
-		data = ffs_prepare_buffer(buf, len);
-		if (IS_ERR(data)) {
-			ret = PTR_ERR(data);
-			break;
-		}
-
-		spin_lock_irq(&ffs->ev.waitq.lock);
-
-		/*
-		 * We are guaranteed to be still in FFS_ACTIVE state
-		 * but the state of setup could have changed from
-		 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
-		 * to check for that.  If that happened we copied data
-		 * from user space in vain but it's unlikely.
-		 *
-		 * For sure we are not in FFS_NO_SETUP since this is
-		 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
-		 * transition can be performed and it's protected by
-		 * mutex.
-		 */
-		if (ffs_setup_state_clear_cancelled(ffs) ==
-		    FFS_SETUP_CANCELLED) {
-			ret = -EIDRM;
-done_spin:
-			spin_unlock_irq(&ffs->ev.waitq.lock);
-		} else {
-			/* unlocks spinlock */
-			ret = __ffs_ep0_queue_wait(ffs, data, len);
-		}
-		kfree(data);
-		break;
-
-	default:
-		ret = -EBADFD;
-		break;
-	}
-
-	mutex_unlock(&ffs->mutex);
-	return ret;
-}
-
-static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
-				     size_t n)
-{
-	/*
-	 * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
-	 * to release them.
-	 */
-	struct usb_functionfs_event events[n];
-	unsigned i = 0;
-
-	memset(events, 0, sizeof events);
-
-	do {
-		events[i].type = ffs->ev.types[i];
-		if (events[i].type == FUNCTIONFS_SETUP) {
-			events[i].u.setup = ffs->ev.setup;
-			ffs->setup_state = FFS_SETUP_PENDING;
-		}
-	} while (++i < n);
-
-	if (n < ffs->ev.count) {
-		ffs->ev.count -= n;
-		memmove(ffs->ev.types, ffs->ev.types + n,
-			ffs->ev.count * sizeof *ffs->ev.types);
-	} else {
-		ffs->ev.count = 0;
-	}
-
-	spin_unlock_irq(&ffs->ev.waitq.lock);
-	mutex_unlock(&ffs->mutex);
-
-	return unlikely(__copy_to_user(buf, events, sizeof events))
-		? -EFAULT : sizeof events;
-}
-
-static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
-			    size_t len, loff_t *ptr)
-{
-	struct ffs_data *ffs = file->private_data;
-	char *data = NULL;
-	size_t n;
-	int ret;
-
-	ENTER();
-
-	/* Fast check if setup was canceled */
-	if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
-		return -EIDRM;
-
-	/* Acquire mutex */
-	ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
-	if (unlikely(ret < 0))
-		return ret;
-
-	/* Check state */
-	if (ffs->state != FFS_ACTIVE) {
-		ret = -EBADFD;
-		goto done_mutex;
-	}
-
-	/*
-	 * We're called from user space, we can use _irq rather then
-	 * _irqsave
-	 */
-	spin_lock_irq(&ffs->ev.waitq.lock);
-
-	switch (ffs_setup_state_clear_cancelled(ffs)) {
-	case FFS_SETUP_CANCELLED:
-		ret = -EIDRM;
-		break;
-
-	case FFS_NO_SETUP:
-		n = len / sizeof(struct usb_functionfs_event);
-		if (unlikely(!n)) {
-			ret = -EINVAL;
-			break;
-		}
-
-		if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
-			ret = -EAGAIN;
-			break;
-		}
-
-		if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
-							ffs->ev.count)) {
-			ret = -EINTR;
-			break;
-		}
-
-		return __ffs_ep0_read_events(ffs, buf,
-					     min(n, (size_t)ffs->ev.count));
-
-	case FFS_SETUP_PENDING:
-		if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
-			spin_unlock_irq(&ffs->ev.waitq.lock);
-			ret = __ffs_ep0_stall(ffs);
-			goto done_mutex;
-		}
-
-		len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
-
-		spin_unlock_irq(&ffs->ev.waitq.lock);
-
-		if (likely(len)) {
-			data = kmalloc(len, GFP_KERNEL);
-			if (unlikely(!data)) {
-				ret = -ENOMEM;
-				goto done_mutex;
-			}
-		}
-
-		spin_lock_irq(&ffs->ev.waitq.lock);
-
-		/* See ffs_ep0_write() */
-		if (ffs_setup_state_clear_cancelled(ffs) ==
-		    FFS_SETUP_CANCELLED) {
-			ret = -EIDRM;
-			break;
-		}
-
-		/* unlocks spinlock */
-		ret = __ffs_ep0_queue_wait(ffs, data, len);
-		if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
-			ret = -EFAULT;
-		goto done_mutex;
-
-	default:
-		ret = -EBADFD;
-		break;
-	}
-
-	spin_unlock_irq(&ffs->ev.waitq.lock);
-done_mutex:
-	mutex_unlock(&ffs->mutex);
-	kfree(data);
-	return ret;
-}
-
-static int ffs_ep0_open(struct inode *inode, struct file *file)
-{
-	struct ffs_data *ffs = inode->i_private;
-
-	ENTER();
-
-	if (unlikely(ffs->state == FFS_CLOSING))
-		return -EBUSY;
-
-	file->private_data = ffs;
-	ffs_data_opened(ffs);
-
-	return 0;
-}
-
-static int ffs_ep0_release(struct inode *inode, struct file *file)
-{
-	struct ffs_data *ffs = file->private_data;
-
-	ENTER();
-
-	ffs_data_closed(ffs);
-
-	return 0;
-}
-
-static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
-{
-	struct ffs_data *ffs = file->private_data;
-	struct usb_gadget *gadget = ffs->gadget;
-	long ret;
-
-	ENTER();
-
-	if (code == FUNCTIONFS_INTERFACE_REVMAP) {
-		struct ffs_function *func = ffs->func;
-		ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
-	} else if (gadget && gadget->ops->ioctl) {
-		ret = gadget->ops->ioctl(gadget, code, value);
-	} else {
-		ret = -ENOTTY;
-	}
-
-	return ret;
-}
-
-static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
-{
-	struct ffs_data *ffs = file->private_data;
-	unsigned int mask = POLLWRNORM;
-	int ret;
-
-	poll_wait(file, &ffs->ev.waitq, wait);
-
-	ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
-	if (unlikely(ret < 0))
-		return mask;
-
-	switch (ffs->state) {
-	case FFS_READ_DESCRIPTORS:
-	case FFS_READ_STRINGS:
-		mask |= POLLOUT;
-		break;
-
-	case FFS_ACTIVE:
-		switch (ffs->setup_state) {
-		case FFS_NO_SETUP:
-			if (ffs->ev.count)
-				mask |= POLLIN;
-			break;
-
-		case FFS_SETUP_PENDING:
-		case FFS_SETUP_CANCELLED:
-			mask |= (POLLIN | POLLOUT);
-			break;
-		}
-	case FFS_CLOSING:
-		break;
-	}
-
-	mutex_unlock(&ffs->mutex);
-
-	return mask;
-}
-
-static const struct file_operations ffs_ep0_operations = {
-	.llseek =	no_llseek,
-
-	.open =		ffs_ep0_open,
-	.write =	ffs_ep0_write,
-	.read =		ffs_ep0_read,
-	.release =	ffs_ep0_release,
-	.unlocked_ioctl =	ffs_ep0_ioctl,
-	.poll =		ffs_ep0_poll,
-};
-
-
-/* "Normal" endpoints operations ********************************************/
-
-static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
-{
-	ENTER();
-	if (likely(req->context)) {
-		struct ffs_ep *ep = _ep->driver_data;
-		ep->status = req->status ? req->status : req->actual;
-		complete(req->context);
-	}
-}
-
-static void ffs_user_copy_worker(struct work_struct *work)
-{
-	struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
-						   work);
-	int ret = io_data->req->status ? io_data->req->status :
-					 io_data->req->actual;
-
-	if (io_data->read && ret > 0) {
-		int i;
-		size_t pos = 0;
-		use_mm(io_data->mm);
-		for (i = 0; i < io_data->nr_segs; i++) {
-			if (unlikely(copy_to_user(io_data->iovec[i].iov_base,
-						 &io_data->buf[pos],
-						 io_data->iovec[i].iov_len))) {
-				ret = -EFAULT;
-				break;
-			}
-			pos += io_data->iovec[i].iov_len;
-		}
-		unuse_mm(io_data->mm);
-	}
-
-	aio_complete(io_data->kiocb, ret, ret);
-
-	usb_ep_free_request(io_data->ep, io_data->req);
-
-	io_data->kiocb->private = NULL;
-	if (io_data->read)
-		kfree(io_data->iovec);
-	kfree(io_data->buf);
-	kfree(io_data);
-}
-
-static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
-					 struct usb_request *req)
-{
-	struct ffs_io_data *io_data = req->context;
-
-	ENTER();
-
-	INIT_WORK(&io_data->work, ffs_user_copy_worker);
-	schedule_work(&io_data->work);
-}
-
-static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
-{
-	struct ffs_epfile *epfile = file->private_data;
-	struct ffs_ep *ep;
-	char *data = NULL;
-	ssize_t ret, data_len;
-	int halt;
-
-	/* Are we still active? */
-	if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
-		ret = -ENODEV;
-		goto error;
-	}
-
-	/* Wait for endpoint to be enabled */
-	ep = epfile->ep;
-	if (!ep) {
-		if (file->f_flags & O_NONBLOCK) {
-			ret = -EAGAIN;
-			goto error;
-		}
-
-		ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
-		if (ret) {
-			ret = -EINTR;
-			goto error;
-		}
-	}
-
-	/* Do we halt? */
-	halt = (!io_data->read == !epfile->in);
-	if (halt && epfile->isoc) {
-		ret = -EINVAL;
-		goto error;
-	}
-
-	/* Allocate & copy */
-	if (!halt) {
-		/*
-		 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
-		 * before the waiting completes, so do not assign to 'gadget' earlier
-		 */
-		struct usb_gadget *gadget = epfile->ffs->gadget;
-
-		spin_lock_irq(&epfile->ffs->eps_lock);
-		/* In the meantime, endpoint got disabled or changed. */
-		if (epfile->ep != ep) {
-			spin_unlock_irq(&epfile->ffs->eps_lock);
-			return -ESHUTDOWN;
-		}
-		/*
-		 * Controller may require buffer size to be aligned to
-		 * maxpacketsize of an out endpoint.
-		 */
-		data_len = io_data->read ?
-			   usb_ep_align_maybe(gadget, ep->ep, io_data->len) :
-			   io_data->len;
-		spin_unlock_irq(&epfile->ffs->eps_lock);
-
-		data = kmalloc(data_len, GFP_KERNEL);
-		if (unlikely(!data))
-			return -ENOMEM;
-		if (io_data->aio && !io_data->read) {
-			int i;
-			size_t pos = 0;
-			for (i = 0; i < io_data->nr_segs; i++) {
-				if (unlikely(copy_from_user(&data[pos],
-					     io_data->iovec[i].iov_base,
-					     io_data->iovec[i].iov_len))) {
-					ret = -EFAULT;
-					goto error;
-				}
-				pos += io_data->iovec[i].iov_len;
-			}
-		} else {
-			if (!io_data->read &&
-			    unlikely(__copy_from_user(data, io_data->buf,
-						      io_data->len))) {
-				ret = -EFAULT;
-				goto error;
-			}
-		}
-	}
-
-	/* We will be using request */
-	ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
-	if (unlikely(ret))
-		goto error;
-
-	spin_lock_irq(&epfile->ffs->eps_lock);
-
-	if (epfile->ep != ep) {
-		/* In the meantime, endpoint got disabled or changed. */
-		ret = -ESHUTDOWN;
-		spin_unlock_irq(&epfile->ffs->eps_lock);
-	} else if (halt) {
-		/* Halt */
-		if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
-			usb_ep_set_halt(ep->ep);
-		spin_unlock_irq(&epfile->ffs->eps_lock);
-		ret = -EBADMSG;
-	} else {
-		/* Fire the request */
-		struct usb_request *req;
-
-		if (io_data->aio) {
-			req = usb_ep_alloc_request(ep->ep, GFP_KERNEL);
-			if (unlikely(!req))
-				goto error_lock;
-
-			req->buf      = data;
-			req->length   = io_data->len;
-
-			io_data->buf = data;
-			io_data->ep = ep->ep;
-			io_data->req = req;
-
-			req->context  = io_data;
-			req->complete = ffs_epfile_async_io_complete;
-
-			ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
-			if (unlikely(ret)) {
-				usb_ep_free_request(ep->ep, req);
-				goto error_lock;
-			}
-			ret = -EIOCBQUEUED;
-
-			spin_unlock_irq(&epfile->ffs->eps_lock);
-		} else {
-			DECLARE_COMPLETION_ONSTACK(done);
-
-			req = ep->req;
-			req->buf      = data;
-			req->length   = io_data->len;
-
-			req->context  = &done;
-			req->complete = ffs_epfile_io_complete;
-
-			ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
-
-			spin_unlock_irq(&epfile->ffs->eps_lock);
-
-			if (unlikely(ret < 0)) {
-				/* nop */
-			} else if (unlikely(
-				   wait_for_completion_interruptible(&done))) {
-				ret = -EINTR;
-				usb_ep_dequeue(ep->ep, req);
-			} else {
-				/*
-				 * XXX We may end up silently droping data
-				 * here.  Since data_len (i.e. req->length) may
-				 * be bigger than len (after being rounded up
-				 * to maxpacketsize), we may end up with more
-				 * data then user space has space for.
-				 */
-				ret = ep->status;
-				if (io_data->read && ret > 0) {
-					ret = min_t(size_t, ret, io_data->len);
-
-					if (unlikely(copy_to_user(io_data->buf,
-						data, ret)))
-						ret = -EFAULT;
-				}
-			}
-			kfree(data);
-		}
-	}
-
-	mutex_unlock(&epfile->mutex);
-	return ret;
-
-error_lock:
-	spin_unlock_irq(&epfile->ffs->eps_lock);
-	mutex_unlock(&epfile->mutex);
-error:
-	kfree(data);
-	return ret;
-}
-
-static ssize_t
-ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
-		 loff_t *ptr)
-{
-	struct ffs_io_data io_data;
-
-	ENTER();
-
-	io_data.aio = false;
-	io_data.read = false;
-	io_data.buf = (char * __user)buf;
-	io_data.len = len;
-
-	return ffs_epfile_io(file, &io_data);
-}
-
-static ssize_t
-ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
-{
-	struct ffs_io_data io_data;
-
-	ENTER();
-
-	io_data.aio = false;
-	io_data.read = true;
-	io_data.buf = buf;
-	io_data.len = len;
-
-	return ffs_epfile_io(file, &io_data);
-}
-
-static int
-ffs_epfile_open(struct inode *inode, struct file *file)
-{
-	struct ffs_epfile *epfile = inode->i_private;
-
-	ENTER();
-
-	if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
-		return -ENODEV;
-
-	file->private_data = epfile;
-	ffs_data_opened(epfile->ffs);
-
-	return 0;
-}
-
-static int ffs_aio_cancel(struct kiocb *kiocb)
-{
-	struct ffs_io_data *io_data = kiocb->private;
-	struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
-	int value;
-
-	ENTER();
-
-	spin_lock_irq(&epfile->ffs->eps_lock);
-
-	if (likely(io_data && io_data->ep && io_data->req))
-		value = usb_ep_dequeue(io_data->ep, io_data->req);
-	else
-		value = -EINVAL;
-
-	spin_unlock_irq(&epfile->ffs->eps_lock);
-
-	return value;
-}
-
-static ssize_t ffs_epfile_aio_write(struct kiocb *kiocb,
-				    const struct iovec *iovec,
-				    unsigned long nr_segs, loff_t loff)
-{
-	struct ffs_io_data *io_data;
-
-	ENTER();
-
-	io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
-	if (unlikely(!io_data))
-		return -ENOMEM;
-
-	io_data->aio = true;
-	io_data->read = false;
-	io_data->kiocb = kiocb;
-	io_data->iovec = iovec;
-	io_data->nr_segs = nr_segs;
-	io_data->len = kiocb->ki_nbytes;
-	io_data->mm = current->mm;
-
-	kiocb->private = io_data;
-
-	kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
-
-	return ffs_epfile_io(kiocb->ki_filp, io_data);
-}
-
-static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
-				   const struct iovec *iovec,
-				   unsigned long nr_segs, loff_t loff)
-{
-	struct ffs_io_data *io_data;
-	struct iovec *iovec_copy;
-
-	ENTER();
-
-	iovec_copy = kmalloc_array(nr_segs, sizeof(*iovec_copy), GFP_KERNEL);
-	if (unlikely(!iovec_copy))
-		return -ENOMEM;
-
-	memcpy(iovec_copy, iovec, sizeof(struct iovec)*nr_segs);
-
-	io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
-	if (unlikely(!io_data)) {
-		kfree(iovec_copy);
-		return -ENOMEM;
-	}
-
-	io_data->aio = true;
-	io_data->read = true;
-	io_data->kiocb = kiocb;
-	io_data->iovec = iovec_copy;
-	io_data->nr_segs = nr_segs;
-	io_data->len = kiocb->ki_nbytes;
-	io_data->mm = current->mm;
-
-	kiocb->private = io_data;
-
-	kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
-
-	return ffs_epfile_io(kiocb->ki_filp, io_data);
-}
-
-static int
-ffs_epfile_release(struct inode *inode, struct file *file)
-{
-	struct ffs_epfile *epfile = inode->i_private;
-
-	ENTER();
-
-	ffs_data_closed(epfile->ffs);
-
-	return 0;
-}
-
-static long ffs_epfile_ioctl(struct file *file, unsigned code,
-			     unsigned long value)
-{
-	struct ffs_epfile *epfile = file->private_data;
-	int ret;
-
-	ENTER();
-
-	if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
-		return -ENODEV;
-
-	spin_lock_irq(&epfile->ffs->eps_lock);
-	if (likely(epfile->ep)) {
-		switch (code) {
-		case FUNCTIONFS_FIFO_STATUS:
-			ret = usb_ep_fifo_status(epfile->ep->ep);
-			break;
-		case FUNCTIONFS_FIFO_FLUSH:
-			usb_ep_fifo_flush(epfile->ep->ep);
-			ret = 0;
-			break;
-		case FUNCTIONFS_CLEAR_HALT:
-			ret = usb_ep_clear_halt(epfile->ep->ep);
-			break;
-		case FUNCTIONFS_ENDPOINT_REVMAP:
-			ret = epfile->ep->num;
-			break;
-		default:
-			ret = -ENOTTY;
-		}
-	} else {
-		ret = -ENODEV;
-	}
-	spin_unlock_irq(&epfile->ffs->eps_lock);
-
-	return ret;
-}
-
-static const struct file_operations ffs_epfile_operations = {
-	.llseek =	no_llseek,
-
-	.open =		ffs_epfile_open,
-	.write =	ffs_epfile_write,
-	.read =		ffs_epfile_read,
-	.aio_write =	ffs_epfile_aio_write,
-	.aio_read =	ffs_epfile_aio_read,
-	.release =	ffs_epfile_release,
-	.unlocked_ioctl =	ffs_epfile_ioctl,
-};
-
-
-/* File system and super block operations ***********************************/
-
-/*
- * Mounting the file system creates a controller file, used first for
- * function configuration then later for event monitoring.
- */
-
-static struct inode *__must_check
-ffs_sb_make_inode(struct super_block *sb, void *data,
-		  const struct file_operations *fops,
-		  const struct inode_operations *iops,
-		  struct ffs_file_perms *perms)
-{
-	struct inode *inode;
-
-	ENTER();
-
-	inode = new_inode(sb);
-
-	if (likely(inode)) {
-		struct timespec current_time = CURRENT_TIME;
-
-		inode->i_ino	 = get_next_ino();
-		inode->i_mode    = perms->mode;
-		inode->i_uid     = perms->uid;
-		inode->i_gid     = perms->gid;
-		inode->i_atime   = current_time;
-		inode->i_mtime   = current_time;
-		inode->i_ctime   = current_time;
-		inode->i_private = data;
-		if (fops)
-			inode->i_fop = fops;
-		if (iops)
-			inode->i_op  = iops;
-	}
-
-	return inode;
-}
-
-/* Create "regular" file */
-static struct inode *ffs_sb_create_file(struct super_block *sb,
-					const char *name, void *data,
-					const struct file_operations *fops,
-					struct dentry **dentry_p)
-{
-	struct ffs_data	*ffs = sb->s_fs_info;
-	struct dentry	*dentry;
-	struct inode	*inode;
-
-	ENTER();
-
-	dentry = d_alloc_name(sb->s_root, name);
-	if (unlikely(!dentry))
-		return NULL;
-
-	inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
-	if (unlikely(!inode)) {
-		dput(dentry);
-		return NULL;
-	}
-
-	d_add(dentry, inode);
-	if (dentry_p)
-		*dentry_p = dentry;
-
-	return inode;
-}
-
-/* Super block */
-static const struct super_operations ffs_sb_operations = {
-	.statfs =	simple_statfs,
-	.drop_inode =	generic_delete_inode,
-};
-
-struct ffs_sb_fill_data {
-	struct ffs_file_perms perms;
-	umode_t root_mode;
-	const char *dev_name;
-	struct ffs_data *ffs_data;
-};
-
-static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
-{
-	struct ffs_sb_fill_data *data = _data;
-	struct inode	*inode;
-	struct ffs_data	*ffs = data->ffs_data;
-
-	ENTER();
-
-	ffs->sb              = sb;
-	data->ffs_data       = NULL;
-	sb->s_fs_info        = ffs;
-	sb->s_blocksize      = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
-	sb->s_magic          = FUNCTIONFS_MAGIC;
-	sb->s_op             = &ffs_sb_operations;
-	sb->s_time_gran      = 1;
-
-	/* Root inode */
-	data->perms.mode = data->root_mode;
-	inode = ffs_sb_make_inode(sb, NULL,
-				  &simple_dir_operations,
-				  &simple_dir_inode_operations,
-				  &data->perms);
-	sb->s_root = d_make_root(inode);
-	if (unlikely(!sb->s_root))
-		return -ENOMEM;
-
-	/* EP0 file */
-	if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
-					 &ffs_ep0_operations, NULL)))
-		return -ENOMEM;
-
-	return 0;
-}
-
-static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
-{
-	ENTER();
-
-	if (!opts || !*opts)
-		return 0;
-
-	for (;;) {
-		unsigned long value;
-		char *eq, *comma;
-
-		/* Option limit */
-		comma = strchr(opts, ',');
-		if (comma)
-			*comma = 0;
-
-		/* Value limit */
-		eq = strchr(opts, '=');
-		if (unlikely(!eq)) {
-			pr_err("'=' missing in %s\n", opts);
-			return -EINVAL;
-		}
-		*eq = 0;
-
-		/* Parse value */
-		if (kstrtoul(eq + 1, 0, &value)) {
-			pr_err("%s: invalid value: %s\n", opts, eq + 1);
-			return -EINVAL;
-		}
-
-		/* Interpret option */
-		switch (eq - opts) {
-		case 5:
-			if (!memcmp(opts, "rmode", 5))
-				data->root_mode  = (value & 0555) | S_IFDIR;
-			else if (!memcmp(opts, "fmode", 5))
-				data->perms.mode = (value & 0666) | S_IFREG;
-			else
-				goto invalid;
-			break;
-
-		case 4:
-			if (!memcmp(opts, "mode", 4)) {
-				data->root_mode  = (value & 0555) | S_IFDIR;
-				data->perms.mode = (value & 0666) | S_IFREG;
-			} else {
-				goto invalid;
-			}
-			break;
-
-		case 3:
-			if (!memcmp(opts, "uid", 3)) {
-				data->perms.uid = make_kuid(current_user_ns(), value);
-				if (!uid_valid(data->perms.uid)) {
-					pr_err("%s: unmapped value: %lu\n", opts, value);
-					return -EINVAL;
-				}
-			} else if (!memcmp(opts, "gid", 3)) {
-				data->perms.gid = make_kgid(current_user_ns(), value);
-				if (!gid_valid(data->perms.gid)) {
-					pr_err("%s: unmapped value: %lu\n", opts, value);
-					return -EINVAL;
-				}
-			} else {
-				goto invalid;
-			}
-			break;
-
-		default:
-invalid:
-			pr_err("%s: invalid option\n", opts);
-			return -EINVAL;
-		}
-
-		/* Next iteration */
-		if (!comma)
-			break;
-		opts = comma + 1;
-	}
-
-	return 0;
-}
-
-/* "mount -t functionfs dev_name /dev/function" ends up here */
-
-static struct dentry *
-ffs_fs_mount(struct file_system_type *t, int flags,
-	      const char *dev_name, void *opts)
-{
-	struct ffs_sb_fill_data data = {
-		.perms = {
-			.mode = S_IFREG | 0600,
-			.uid = GLOBAL_ROOT_UID,
-			.gid = GLOBAL_ROOT_GID,
-		},
-		.root_mode = S_IFDIR | 0500,
-	};
-	struct dentry *rv;
-	int ret;
-	void *ffs_dev;
-	struct ffs_data	*ffs;
-
-	ENTER();
-
-	ret = ffs_fs_parse_opts(&data, opts);
-	if (unlikely(ret < 0))
-		return ERR_PTR(ret);
-
-	ffs = ffs_data_new();
-	if (unlikely(!ffs))
-		return ERR_PTR(-ENOMEM);
-	ffs->file_perms = data.perms;
-
-	ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
-	if (unlikely(!ffs->dev_name)) {
-		ffs_data_put(ffs);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	ffs_dev = ffs_acquire_dev(dev_name);
-	if (IS_ERR(ffs_dev)) {
-		ffs_data_put(ffs);
-		return ERR_CAST(ffs_dev);
-	}
-	ffs->private_data = ffs_dev;
-	data.ffs_data = ffs;
-
-	rv = mount_nodev(t, flags, &data, ffs_sb_fill);
-	if (IS_ERR(rv) && data.ffs_data) {
-		ffs_release_dev(data.ffs_data);
-		ffs_data_put(data.ffs_data);
-	}
-	return rv;
-}
-
-static void
-ffs_fs_kill_sb(struct super_block *sb)
-{
-	ENTER();
-
-	kill_litter_super(sb);
-	if (sb->s_fs_info) {
-		ffs_release_dev(sb->s_fs_info);
-		ffs_data_put(sb->s_fs_info);
-	}
-}
-
-static struct file_system_type ffs_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "functionfs",
-	.mount		= ffs_fs_mount,
-	.kill_sb	= ffs_fs_kill_sb,
-};
-MODULE_ALIAS_FS("functionfs");
-
-
-/* Driver's main init/cleanup functions *************************************/
-
-static int functionfs_init(void)
-{
-	int ret;
-
-	ENTER();
-
-	ret = register_filesystem(&ffs_fs_type);
-	if (likely(!ret))
-		pr_info("file system registered\n");
-	else
-		pr_err("failed registering file system (%d)\n", ret);
-
-	return ret;
-}
-
-static void functionfs_cleanup(void)
-{
-	ENTER();
-
-	pr_info("unloading\n");
-	unregister_filesystem(&ffs_fs_type);
-}
-
-
-/* ffs_data and ffs_function construction and destruction code **************/
-
-static void ffs_data_clear(struct ffs_data *ffs);
-static void ffs_data_reset(struct ffs_data *ffs);
-
-static void ffs_data_get(struct ffs_data *ffs)
-{
-	ENTER();
-
-	atomic_inc(&ffs->ref);
-}
-
-static void ffs_data_opened(struct ffs_data *ffs)
-{
-	ENTER();
-
-	atomic_inc(&ffs->ref);
-	atomic_inc(&ffs->opened);
-}
-
-static void ffs_data_put(struct ffs_data *ffs)
-{
-	ENTER();
-
-	if (unlikely(atomic_dec_and_test(&ffs->ref))) {
-		pr_info("%s(): freeing\n", __func__);
-		ffs_data_clear(ffs);
-		BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
-		       waitqueue_active(&ffs->ep0req_completion.wait));
-		kfree(ffs->dev_name);
-		kfree(ffs);
-	}
-}
-
-static void ffs_data_closed(struct ffs_data *ffs)
-{
-	ENTER();
-
-	if (atomic_dec_and_test(&ffs->opened)) {
-		ffs->state = FFS_CLOSING;
-		ffs_data_reset(ffs);
-	}
-
-	ffs_data_put(ffs);
-}
-
-static struct ffs_data *ffs_data_new(void)
-{
-	struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
-	if (unlikely(!ffs))
-		return NULL;
-
-	ENTER();
-
-	atomic_set(&ffs->ref, 1);
-	atomic_set(&ffs->opened, 0);
-	ffs->state = FFS_READ_DESCRIPTORS;
-	mutex_init(&ffs->mutex);
-	spin_lock_init(&ffs->eps_lock);
-	init_waitqueue_head(&ffs->ev.waitq);
-	init_completion(&ffs->ep0req_completion);
-
-	/* XXX REVISIT need to update it in some places, or do we? */
-	ffs->ev.can_stall = 1;
-
-	return ffs;
-}
-
-static void ffs_data_clear(struct ffs_data *ffs)
-{
-	ENTER();
-
-	if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
-		ffs_closed(ffs);
-
-	BUG_ON(ffs->gadget);
-
-	if (ffs->epfiles)
-		ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
-
-	kfree(ffs->raw_descs_data);
-	kfree(ffs->raw_strings);
-	kfree(ffs->stringtabs);
-}
-
-static void ffs_data_reset(struct ffs_data *ffs)
-{
-	ENTER();
-
-	ffs_data_clear(ffs);
-
-	ffs->epfiles = NULL;
-	ffs->raw_descs_data = NULL;
-	ffs->raw_descs = NULL;
-	ffs->raw_strings = NULL;
-	ffs->stringtabs = NULL;
-
-	ffs->raw_descs_length = 0;
-	ffs->fs_descs_count = 0;
-	ffs->hs_descs_count = 0;
-	ffs->ss_descs_count = 0;
-
-	ffs->strings_count = 0;
-	ffs->interfaces_count = 0;
-	ffs->eps_count = 0;
-
-	ffs->ev.count = 0;
-
-	ffs->state = FFS_READ_DESCRIPTORS;
-	ffs->setup_state = FFS_NO_SETUP;
-	ffs->flags = 0;
-}
-
-
-static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
-{
-	struct usb_gadget_strings **lang;
-	int first_id;
-
-	ENTER();
-
-	if (WARN_ON(ffs->state != FFS_ACTIVE
-		 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
-		return -EBADFD;
-
-	first_id = usb_string_ids_n(cdev, ffs->strings_count);
-	if (unlikely(first_id < 0))
-		return first_id;
-
-	ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
-	if (unlikely(!ffs->ep0req))
-		return -ENOMEM;
-	ffs->ep0req->complete = ffs_ep0_complete;
-	ffs->ep0req->context = ffs;
-
-	lang = ffs->stringtabs;
-	for (lang = ffs->stringtabs; *lang; ++lang) {
-		struct usb_string *str = (*lang)->strings;
-		int id = first_id;
-		for (; str->s; ++id, ++str)
-			str->id = id;
-	}
-
-	ffs->gadget = cdev->gadget;
-	ffs_data_get(ffs);
-	return 0;
-}
-
-static void functionfs_unbind(struct ffs_data *ffs)
-{
-	ENTER();
-
-	if (!WARN_ON(!ffs->gadget)) {
-		usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
-		ffs->ep0req = NULL;
-		ffs->gadget = NULL;
-		clear_bit(FFS_FL_BOUND, &ffs->flags);
-		ffs_data_put(ffs);
-	}
-}
-
-static int ffs_epfiles_create(struct ffs_data *ffs)
-{
-	struct ffs_epfile *epfile, *epfiles;
-	unsigned i, count;
-
-	ENTER();
-
-	count = ffs->eps_count;
-	epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
-	if (!epfiles)
-		return -ENOMEM;
-
-	epfile = epfiles;
-	for (i = 1; i <= count; ++i, ++epfile) {
-		epfile->ffs = ffs;
-		mutex_init(&epfile->mutex);
-		init_waitqueue_head(&epfile->wait);
-		sprintf(epfiles->name, "ep%u",  i);
-		if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
-						 &ffs_epfile_operations,
-						 &epfile->dentry))) {
-			ffs_epfiles_destroy(epfiles, i - 1);
-			return -ENOMEM;
-		}
-	}
-
-	ffs->epfiles = epfiles;
-	return 0;
-}
-
-static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
-{
-	struct ffs_epfile *epfile = epfiles;
-
-	ENTER();
-
-	for (; count; --count, ++epfile) {
-		BUG_ON(mutex_is_locked(&epfile->mutex) ||
-		       waitqueue_active(&epfile->wait));
-		if (epfile->dentry) {
-			d_delete(epfile->dentry);
-			dput(epfile->dentry);
-			epfile->dentry = NULL;
-		}
-	}
-
-	kfree(epfiles);
-}
-
-
-static void ffs_func_eps_disable(struct ffs_function *func)
-{
-	struct ffs_ep *ep         = func->eps;
-	struct ffs_epfile *epfile = func->ffs->epfiles;
-	unsigned count            = func->ffs->eps_count;
-	unsigned long flags;
-
-	spin_lock_irqsave(&func->ffs->eps_lock, flags);
-	do {
-		/* pending requests get nuked */
-		if (likely(ep->ep))
-			usb_ep_disable(ep->ep);
-		epfile->ep = NULL;
-
-		++ep;
-		++epfile;
-	} while (--count);
-	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
-}
-
-static int ffs_func_eps_enable(struct ffs_function *func)
-{
-	struct ffs_data *ffs      = func->ffs;
-	struct ffs_ep *ep         = func->eps;
-	struct ffs_epfile *epfile = ffs->epfiles;
-	unsigned count            = ffs->eps_count;
-	unsigned long flags;
-	int ret = 0;
-
-	spin_lock_irqsave(&func->ffs->eps_lock, flags);
-	do {
-		struct usb_endpoint_descriptor *ds;
-		int desc_idx;
-
-		if (ffs->gadget->speed == USB_SPEED_SUPER)
-			desc_idx = 2;
-		else if (ffs->gadget->speed == USB_SPEED_HIGH)
-			desc_idx = 1;
-		else
-			desc_idx = 0;
-
-		/* fall-back to lower speed if desc missing for current speed */
-		do {
-			ds = ep->descs[desc_idx];
-		} while (!ds && --desc_idx >= 0);
-
-		if (!ds) {
-			ret = -EINVAL;
-			break;
-		}
-
-		ep->ep->driver_data = ep;
-		ep->ep->desc = ds;
-		ret = usb_ep_enable(ep->ep);
-		if (likely(!ret)) {
-			epfile->ep = ep;
-			epfile->in = usb_endpoint_dir_in(ds);
-			epfile->isoc = usb_endpoint_xfer_isoc(ds);
-		} else {
-			break;
-		}
-
-		wake_up(&epfile->wait);
-
-		++ep;
-		++epfile;
-	} while (--count);
-	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
-
-	return ret;
-}
-
-
-/* Parsing and building descriptors and strings *****************************/
-
-/*
- * This validates if data pointed by data is a valid USB descriptor as
- * well as record how many interfaces, endpoints and strings are
- * required by given configuration.  Returns address after the
- * descriptor or NULL if data is invalid.
- */
-
-enum ffs_entity_type {
-	FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
-};
-
-enum ffs_os_desc_type {
-	FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
-};
-
-typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
-				   u8 *valuep,
-				   struct usb_descriptor_header *desc,
-				   void *priv);
-
-typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
-				    struct usb_os_desc_header *h, void *data,
-				    unsigned len, void *priv);
-
-static int __must_check ffs_do_single_desc(char *data, unsigned len,
-					   ffs_entity_callback entity,
-					   void *priv)
-{
-	struct usb_descriptor_header *_ds = (void *)data;
-	u8 length;
-	int ret;
-
-	ENTER();
-
-	/* At least two bytes are required: length and type */
-	if (len < 2) {
-		pr_vdebug("descriptor too short\n");
-		return -EINVAL;
-	}
-
-	/* If we have at least as many bytes as the descriptor takes? */
-	length = _ds->bLength;
-	if (len < length) {
-		pr_vdebug("descriptor longer then available data\n");
-		return -EINVAL;
-	}
-
-#define __entity_check_INTERFACE(val)  1
-#define __entity_check_STRING(val)     (val)
-#define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
-#define __entity(type, val) do {					\
-		pr_vdebug("entity " #type "(%02x)\n", (val));		\
-		if (unlikely(!__entity_check_ ##type(val))) {		\
-			pr_vdebug("invalid entity's value\n");		\
-			return -EINVAL;					\
-		}							\
-		ret = entity(FFS_ ##type, &val, _ds, priv);		\
-		if (unlikely(ret < 0)) {				\
-			pr_debug("entity " #type "(%02x); ret = %d\n",	\
-				 (val), ret);				\
-			return ret;					\
-		}							\
-	} while (0)
-
-	/* Parse descriptor depending on type. */
-	switch (_ds->bDescriptorType) {
-	case USB_DT_DEVICE:
-	case USB_DT_CONFIG:
-	case USB_DT_STRING:
-	case USB_DT_DEVICE_QUALIFIER:
-		/* function can't have any of those */
-		pr_vdebug("descriptor reserved for gadget: %d\n",
-		      _ds->bDescriptorType);
-		return -EINVAL;
-
-	case USB_DT_INTERFACE: {
-		struct usb_interface_descriptor *ds = (void *)_ds;
-		pr_vdebug("interface descriptor\n");
-		if (length != sizeof *ds)
-			goto inv_length;
-
-		__entity(INTERFACE, ds->bInterfaceNumber);
-		if (ds->iInterface)
-			__entity(STRING, ds->iInterface);
-	}
-		break;
-
-	case USB_DT_ENDPOINT: {
-		struct usb_endpoint_descriptor *ds = (void *)_ds;
-		pr_vdebug("endpoint descriptor\n");
-		if (length != USB_DT_ENDPOINT_SIZE &&
-		    length != USB_DT_ENDPOINT_AUDIO_SIZE)
-			goto inv_length;
-		__entity(ENDPOINT, ds->bEndpointAddress);
-	}
-		break;
-
-	case HID_DT_HID:
-		pr_vdebug("hid descriptor\n");
-		if (length != sizeof(struct hid_descriptor))
-			goto inv_length;
-		break;
-
-	case USB_DT_OTG:
-		if (length != sizeof(struct usb_otg_descriptor))
-			goto inv_length;
-		break;
-
-	case USB_DT_INTERFACE_ASSOCIATION: {
-		struct usb_interface_assoc_descriptor *ds = (void *)_ds;
-		pr_vdebug("interface association descriptor\n");
-		if (length != sizeof *ds)
-			goto inv_length;
-		if (ds->iFunction)
-			__entity(STRING, ds->iFunction);
-	}
-		break;
-
-	case USB_DT_SS_ENDPOINT_COMP:
-		pr_vdebug("EP SS companion descriptor\n");
-		if (length != sizeof(struct usb_ss_ep_comp_descriptor))
-			goto inv_length;
-		break;
-
-	case USB_DT_OTHER_SPEED_CONFIG:
-	case USB_DT_INTERFACE_POWER:
-	case USB_DT_DEBUG:
-	case USB_DT_SECURITY:
-	case USB_DT_CS_RADIO_CONTROL:
-		/* TODO */
-		pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
-		return -EINVAL;
-
-	default:
-		/* We should never be here */
-		pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
-		return -EINVAL;
-
-inv_length:
-		pr_vdebug("invalid length: %d (descriptor %d)\n",
-			  _ds->bLength, _ds->bDescriptorType);
-		return -EINVAL;
-	}
-
-#undef __entity
-#undef __entity_check_DESCRIPTOR
-#undef __entity_check_INTERFACE
-#undef __entity_check_STRING
-#undef __entity_check_ENDPOINT
-
-	return length;
-}
-
-static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
-				     ffs_entity_callback entity, void *priv)
-{
-	const unsigned _len = len;
-	unsigned long num = 0;
-
-	ENTER();
-
-	for (;;) {
-		int ret;
-
-		if (num == count)
-			data = NULL;
-
-		/* Record "descriptor" entity */
-		ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
-		if (unlikely(ret < 0)) {
-			pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
-				 num, ret);
-			return ret;
-		}
-
-		if (!data)
-			return _len - len;
-
-		ret = ffs_do_single_desc(data, len, entity, priv);
-		if (unlikely(ret < 0)) {
-			pr_debug("%s returns %d\n", __func__, ret);
-			return ret;
-		}
-
-		len -= ret;
-		data += ret;
-		++num;
-	}
-}
-
-static int __ffs_data_do_entity(enum ffs_entity_type type,
-				u8 *valuep, struct usb_descriptor_header *desc,
-				void *priv)
-{
-	struct ffs_data *ffs = priv;
-
-	ENTER();
-
-	switch (type) {
-	case FFS_DESCRIPTOR:
-		break;
-
-	case FFS_INTERFACE:
-		/*
-		 * Interfaces are indexed from zero so if we
-		 * encountered interface "n" then there are at least
-		 * "n+1" interfaces.
-		 */
-		if (*valuep >= ffs->interfaces_count)
-			ffs->interfaces_count = *valuep + 1;
-		break;
-
-	case FFS_STRING:
-		/*
-		 * Strings are indexed from 1 (0 is magic ;) reserved
-		 * for languages list or some such)
-		 */
-		if (*valuep > ffs->strings_count)
-			ffs->strings_count = *valuep;
-		break;
-
-	case FFS_ENDPOINT:
-		/* Endpoints are indexed from 1 as well. */
-		if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
-			ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
-		break;
-	}
-
-	return 0;
-}
-
-static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
-				   struct usb_os_desc_header *desc)
-{
-	u16 bcd_version = le16_to_cpu(desc->bcdVersion);
-	u16 w_index = le16_to_cpu(desc->wIndex);
-
-	if (bcd_version != 1) {
-		pr_vdebug("unsupported os descriptors version: %d",
-			  bcd_version);
-		return -EINVAL;
-	}
-	switch (w_index) {
-	case 0x4:
-		*next_type = FFS_OS_DESC_EXT_COMPAT;
-		break;
-	case 0x5:
-		*next_type = FFS_OS_DESC_EXT_PROP;
-		break;
-	default:
-		pr_vdebug("unsupported os descriptor type: %d", w_index);
-		return -EINVAL;
-	}
-
-	return sizeof(*desc);
-}
-
-/*
- * Process all extended compatibility/extended property descriptors
- * of a feature descriptor
- */
-static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
-					      enum ffs_os_desc_type type,
-					      u16 feature_count,
-					      ffs_os_desc_callback entity,
-					      void *priv,
-					      struct usb_os_desc_header *h)
-{
-	int ret;
-	const unsigned _len = len;
-
-	ENTER();
-
-	/* loop over all ext compat/ext prop descriptors */
-	while (feature_count--) {
-		ret = entity(type, h, data, len, priv);
-		if (unlikely(ret < 0)) {
-			pr_debug("bad OS descriptor, type: %d\n", type);
-			return ret;
-		}
-		data += ret;
-		len -= ret;
-	}
-	return _len - len;
-}
-
-/* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
-static int __must_check ffs_do_os_descs(unsigned count,
-					char *data, unsigned len,
-					ffs_os_desc_callback entity, void *priv)
-{
-	const unsigned _len = len;
-	unsigned long num = 0;
-
-	ENTER();
-
-	for (num = 0; num < count; ++num) {
-		int ret;
-		enum ffs_os_desc_type type;
-		u16 feature_count;
-		struct usb_os_desc_header *desc = (void *)data;
-
-		if (len < sizeof(*desc))
-			return -EINVAL;
-
-		/*
-		 * Record "descriptor" entity.
-		 * Process dwLength, bcdVersion, wIndex, get b/wCount.
-		 * Move the data pointer to the beginning of extended
-		 * compatibilities proper or extended properties proper
-		 * portions of the data
-		 */
-		if (le32_to_cpu(desc->dwLength) > len)
-			return -EINVAL;
-
-		ret = __ffs_do_os_desc_header(&type, desc);
-		if (unlikely(ret < 0)) {
-			pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
-				 num, ret);
-			return ret;
-		}
-		/*
-		 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
-		 */
-		feature_count = le16_to_cpu(desc->wCount);
-		if (type == FFS_OS_DESC_EXT_COMPAT &&
-		    (feature_count > 255 || desc->Reserved))
-				return -EINVAL;
-		len -= ret;
-		data += ret;
-
-		/*
-		 * Process all function/property descriptors
-		 * of this Feature Descriptor
-		 */
-		ret = ffs_do_single_os_desc(data, len, type,
-					    feature_count, entity, priv, desc);
-		if (unlikely(ret < 0)) {
-			pr_debug("%s returns %d\n", __func__, ret);
-			return ret;
-		}
-
-		len -= ret;
-		data += ret;
-	}
-	return _len - len;
-}
-
-/**
- * Validate contents of the buffer from userspace related to OS descriptors.
- */
-static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
-				 struct usb_os_desc_header *h, void *data,
-				 unsigned len, void *priv)
-{
-	struct ffs_data *ffs = priv;
-	u8 length;
-
-	ENTER();
-
-	switch (type) {
-	case FFS_OS_DESC_EXT_COMPAT: {
-		struct usb_ext_compat_desc *d = data;
-		int i;
-
-		if (len < sizeof(*d) ||
-		    d->bFirstInterfaceNumber >= ffs->interfaces_count ||
-		    d->Reserved1)
-			return -EINVAL;
-		for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
-			if (d->Reserved2[i])
-				return -EINVAL;
-
-		length = sizeof(struct usb_ext_compat_desc);
-	}
-		break;
-	case FFS_OS_DESC_EXT_PROP: {
-		struct usb_ext_prop_desc *d = data;
-		u32 type, pdl;
-		u16 pnl;
-
-		if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
-			return -EINVAL;
-		length = le32_to_cpu(d->dwSize);
-		type = le32_to_cpu(d->dwPropertyDataType);
-		if (type < USB_EXT_PROP_UNICODE ||
-		    type > USB_EXT_PROP_UNICODE_MULTI) {
-			pr_vdebug("unsupported os descriptor property type: %d",
-				  type);
-			return -EINVAL;
-		}
-		pnl = le16_to_cpu(d->wPropertyNameLength);
-		pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
-		if (length != 14 + pnl + pdl) {
-			pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
-				  length, pnl, pdl, type);
-			return -EINVAL;
-		}
-		++ffs->ms_os_descs_ext_prop_count;
-		/* property name reported to the host as "WCHAR"s */
-		ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
-		ffs->ms_os_descs_ext_prop_data_len += pdl;
-	}
-		break;
-	default:
-		pr_vdebug("unknown descriptor: %d\n", type);
-		return -EINVAL;
-	}
-	return length;
-}
-
-static int __ffs_data_got_descs(struct ffs_data *ffs,
-				char *const _data, size_t len)
-{
-	char *data = _data, *raw_descs;
-	unsigned os_descs_count = 0, counts[3], flags;
-	int ret = -EINVAL, i;
-
-	ENTER();
-
-	if (get_unaligned_le32(data + 4) != len)
-		goto error;
-
-	switch (get_unaligned_le32(data)) {
-	case FUNCTIONFS_DESCRIPTORS_MAGIC:
-		flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
-		data += 8;
-		len  -= 8;
-		break;
-	case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
-		flags = get_unaligned_le32(data + 8);
-		if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
-			      FUNCTIONFS_HAS_HS_DESC |
-			      FUNCTIONFS_HAS_SS_DESC |
-			      FUNCTIONFS_HAS_MS_OS_DESC)) {
-			ret = -ENOSYS;
-			goto error;
-		}
-		data += 12;
-		len  -= 12;
-		break;
-	default:
-		goto error;
-	}
-
-	/* Read fs_count, hs_count and ss_count (if present) */
-	for (i = 0; i < 3; ++i) {
-		if (!(flags & (1 << i))) {
-			counts[i] = 0;
-		} else if (len < 4) {
-			goto error;
-		} else {
-			counts[i] = get_unaligned_le32(data);
-			data += 4;
-			len  -= 4;
-		}
-	}
-	if (flags & (1 << i)) {
-		os_descs_count = get_unaligned_le32(data);
-		data += 4;
-		len -= 4;
-	};
-
-	/* Read descriptors */
-	raw_descs = data;
-	for (i = 0; i < 3; ++i) {
-		if (!counts[i])
-			continue;
-		ret = ffs_do_descs(counts[i], data, len,
-				   __ffs_data_do_entity, ffs);
-		if (ret < 0)
-			goto error;
-		data += ret;
-		len  -= ret;
-	}
-	if (os_descs_count) {
-		ret = ffs_do_os_descs(os_descs_count, data, len,
-				      __ffs_data_do_os_desc, ffs);
-		if (ret < 0)
-			goto error;
-		data += ret;
-		len -= ret;
-	}
-
-	if (raw_descs == data || len) {
-		ret = -EINVAL;
-		goto error;
-	}
-
-	ffs->raw_descs_data	= _data;
-	ffs->raw_descs		= raw_descs;
-	ffs->raw_descs_length	= data - raw_descs;
-	ffs->fs_descs_count	= counts[0];
-	ffs->hs_descs_count	= counts[1];
-	ffs->ss_descs_count	= counts[2];
-	ffs->ms_os_descs_count	= os_descs_count;
-
-	return 0;
-
-error:
-	kfree(_data);
-	return ret;
-}
-
-static int __ffs_data_got_strings(struct ffs_data *ffs,
-				  char *const _data, size_t len)
-{
-	u32 str_count, needed_count, lang_count;
-	struct usb_gadget_strings **stringtabs, *t;
-	struct usb_string *strings, *s;
-	const char *data = _data;
-
-	ENTER();
-
-	if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
-		     get_unaligned_le32(data + 4) != len))
-		goto error;
-	str_count  = get_unaligned_le32(data + 8);
-	lang_count = get_unaligned_le32(data + 12);
-
-	/* if one is zero the other must be zero */
-	if (unlikely(!str_count != !lang_count))
-		goto error;
-
-	/* Do we have at least as many strings as descriptors need? */
-	needed_count = ffs->strings_count;
-	if (unlikely(str_count < needed_count))
-		goto error;
-
-	/*
-	 * If we don't need any strings just return and free all
-	 * memory.
-	 */
-	if (!needed_count) {
-		kfree(_data);
-		return 0;
-	}
-
-	/* Allocate everything in one chunk so there's less maintenance. */
-	{
-		unsigned i = 0;
-		vla_group(d);
-		vla_item(d, struct usb_gadget_strings *, stringtabs,
-			lang_count + 1);
-		vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
-		vla_item(d, struct usb_string, strings,
-			lang_count*(needed_count+1));
-
-		char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
-
-		if (unlikely(!vlabuf)) {
-			kfree(_data);
-			return -ENOMEM;
-		}
-
-		/* Initialize the VLA pointers */
-		stringtabs = vla_ptr(vlabuf, d, stringtabs);
-		t = vla_ptr(vlabuf, d, stringtab);
-		i = lang_count;
-		do {
-			*stringtabs++ = t++;
-		} while (--i);
-		*stringtabs = NULL;
-
-		/* stringtabs = vlabuf = d_stringtabs for later kfree */
-		stringtabs = vla_ptr(vlabuf, d, stringtabs);
-		t = vla_ptr(vlabuf, d, stringtab);
-		s = vla_ptr(vlabuf, d, strings);
-		strings = s;
-	}
-
-	/* For each language */
-	data += 16;
-	len -= 16;
-
-	do { /* lang_count > 0 so we can use do-while */
-		unsigned needed = needed_count;
-
-		if (unlikely(len < 3))
-			goto error_free;
-		t->language = get_unaligned_le16(data);
-		t->strings  = s;
-		++t;
-
-		data += 2;
-		len -= 2;
-
-		/* For each string */
-		do { /* str_count > 0 so we can use do-while */
-			size_t length = strnlen(data, len);
-
-			if (unlikely(length == len))
-				goto error_free;
-
-			/*
-			 * User may provide more strings then we need,
-			 * if that's the case we simply ignore the
-			 * rest
-			 */
-			if (likely(needed)) {
-				/*
-				 * s->id will be set while adding
-				 * function to configuration so for
-				 * now just leave garbage here.
-				 */
-				s->s = data;
-				--needed;
-				++s;
-			}
-
-			data += length + 1;
-			len -= length + 1;
-		} while (--str_count);
-
-		s->id = 0;   /* terminator */
-		s->s = NULL;
-		++s;
-
-	} while (--lang_count);
-
-	/* Some garbage left? */
-	if (unlikely(len))
-		goto error_free;
-
-	/* Done! */
-	ffs->stringtabs = stringtabs;
-	ffs->raw_strings = _data;
-
-	return 0;
-
-error_free:
-	kfree(stringtabs);
-error:
-	kfree(_data);
-	return -EINVAL;
-}
-
-
-/* Events handling and management *******************************************/
-
-static void __ffs_event_add(struct ffs_data *ffs,
-			    enum usb_functionfs_event_type type)
-{
-	enum usb_functionfs_event_type rem_type1, rem_type2 = type;
-	int neg = 0;
-
-	/*
-	 * Abort any unhandled setup
-	 *
-	 * We do not need to worry about some cmpxchg() changing value
-	 * of ffs->setup_state without holding the lock because when
-	 * state is FFS_SETUP_PENDING cmpxchg() in several places in
-	 * the source does nothing.
-	 */
-	if (ffs->setup_state == FFS_SETUP_PENDING)
-		ffs->setup_state = FFS_SETUP_CANCELLED;
-
-	switch (type) {
-	case FUNCTIONFS_RESUME:
-		rem_type2 = FUNCTIONFS_SUSPEND;
-		/* FALL THROUGH */
-	case FUNCTIONFS_SUSPEND:
-	case FUNCTIONFS_SETUP:
-		rem_type1 = type;
-		/* Discard all similar events */
-		break;
-
-	case FUNCTIONFS_BIND:
-	case FUNCTIONFS_UNBIND:
-	case FUNCTIONFS_DISABLE:
-	case FUNCTIONFS_ENABLE:
-		/* Discard everything other then power management. */
-		rem_type1 = FUNCTIONFS_SUSPEND;
-		rem_type2 = FUNCTIONFS_RESUME;
-		neg = 1;
-		break;
-
-	default:
-		BUG();
-	}
-
-	{
-		u8 *ev  = ffs->ev.types, *out = ev;
-		unsigned n = ffs->ev.count;
-		for (; n; --n, ++ev)
-			if ((*ev == rem_type1 || *ev == rem_type2) == neg)
-				*out++ = *ev;
-			else
-				pr_vdebug("purging event %d\n", *ev);
-		ffs->ev.count = out - ffs->ev.types;
-	}
-
-	pr_vdebug("adding event %d\n", type);
-	ffs->ev.types[ffs->ev.count++] = type;
-	wake_up_locked(&ffs->ev.waitq);
-}
-
-static void ffs_event_add(struct ffs_data *ffs,
-			  enum usb_functionfs_event_type type)
-{
-	unsigned long flags;
-	spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
-	__ffs_event_add(ffs, type);
-	spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
-}
-
-
-/* Bind/unbind USB function hooks *******************************************/
-
-static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
-				    struct usb_descriptor_header *desc,
-				    void *priv)
-{
-	struct usb_endpoint_descriptor *ds = (void *)desc;
-	struct ffs_function *func = priv;
-	struct ffs_ep *ffs_ep;
-	unsigned ep_desc_id, idx;
-	static const char *speed_names[] = { "full", "high", "super" };
-
-	if (type != FFS_DESCRIPTOR)
-		return 0;
-
-	/*
-	 * If ss_descriptors is not NULL, we are reading super speed
-	 * descriptors; if hs_descriptors is not NULL, we are reading high
-	 * speed descriptors; otherwise, we are reading full speed
-	 * descriptors.
-	 */
-	if (func->function.ss_descriptors) {
-		ep_desc_id = 2;
-		func->function.ss_descriptors[(long)valuep] = desc;
-	} else if (func->function.hs_descriptors) {
-		ep_desc_id = 1;
-		func->function.hs_descriptors[(long)valuep] = desc;
-	} else {
-		ep_desc_id = 0;
-		func->function.fs_descriptors[(long)valuep]    = desc;
-	}
-
-	if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
-		return 0;
-
-	idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
-	ffs_ep = func->eps + idx;
-
-	if (unlikely(ffs_ep->descs[ep_desc_id])) {
-		pr_err("two %sspeed descriptors for EP %d\n",
-			  speed_names[ep_desc_id],
-			  ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
-		return -EINVAL;
-	}
-	ffs_ep->descs[ep_desc_id] = ds;
-
-	ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
-	if (ffs_ep->ep) {
-		ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
-		if (!ds->wMaxPacketSize)
-			ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
-	} else {
-		struct usb_request *req;
-		struct usb_ep *ep;
-
-		pr_vdebug("autoconfig\n");
-		ep = usb_ep_autoconfig(func->gadget, ds);
-		if (unlikely(!ep))
-			return -ENOTSUPP;
-		ep->driver_data = func->eps + idx;
-
-		req = usb_ep_alloc_request(ep, GFP_KERNEL);
-		if (unlikely(!req))
-			return -ENOMEM;
-
-		ffs_ep->ep  = ep;
-		ffs_ep->req = req;
-		func->eps_revmap[ds->bEndpointAddress &
-				 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
-	}
-	ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
-
-	return 0;
-}
-
-static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
-				   struct usb_descriptor_header *desc,
-				   void *priv)
-{
-	struct ffs_function *func = priv;
-	unsigned idx;
-	u8 newValue;
-
-	switch (type) {
-	default:
-	case FFS_DESCRIPTOR:
-		/* Handled in previous pass by __ffs_func_bind_do_descs() */
-		return 0;
-
-	case FFS_INTERFACE:
-		idx = *valuep;
-		if (func->interfaces_nums[idx] < 0) {
-			int id = usb_interface_id(func->conf, &func->function);
-			if (unlikely(id < 0))
-				return id;
-			func->interfaces_nums[idx] = id;
-		}
-		newValue = func->interfaces_nums[idx];
-		break;
-
-	case FFS_STRING:
-		/* String' IDs are allocated when fsf_data is bound to cdev */
-		newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
-		break;
-
-	case FFS_ENDPOINT:
-		/*
-		 * USB_DT_ENDPOINT are handled in
-		 * __ffs_func_bind_do_descs().
-		 */
-		if (desc->bDescriptorType == USB_DT_ENDPOINT)
-			return 0;
-
-		idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
-		if (unlikely(!func->eps[idx].ep))
-			return -EINVAL;
-
-		{
-			struct usb_endpoint_descriptor **descs;
-			descs = func->eps[idx].descs;
-			newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
-		}
-		break;
-	}
-
-	pr_vdebug("%02x -> %02x\n", *valuep, newValue);
-	*valuep = newValue;
-	return 0;
-}
-
-static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
-				      struct usb_os_desc_header *h, void *data,
-				      unsigned len, void *priv)
-{
-	struct ffs_function *func = priv;
-	u8 length = 0;
-
-	switch (type) {
-	case FFS_OS_DESC_EXT_COMPAT: {
-		struct usb_ext_compat_desc *desc = data;
-		struct usb_os_desc_table *t;
-
-		t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
-		t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
-		memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
-		       ARRAY_SIZE(desc->CompatibleID) +
-		       ARRAY_SIZE(desc->SubCompatibleID));
-		length = sizeof(*desc);
-	}
-		break;
-	case FFS_OS_DESC_EXT_PROP: {
-		struct usb_ext_prop_desc *desc = data;
-		struct usb_os_desc_table *t;
-		struct usb_os_desc_ext_prop *ext_prop;
-		char *ext_prop_name;
-		char *ext_prop_data;
-
-		t = &func->function.os_desc_table[h->interface];
-		t->if_id = func->interfaces_nums[h->interface];
-
-		ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
-		func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
-
-		ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
-		ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
-		ext_prop->data_len = le32_to_cpu(*(u32 *)
-			usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
-		length = ext_prop->name_len + ext_prop->data_len + 14;
-
-		ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
-		func->ffs->ms_os_descs_ext_prop_name_avail +=
-			ext_prop->name_len;
-
-		ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
-		func->ffs->ms_os_descs_ext_prop_data_avail +=
-			ext_prop->data_len;
-		memcpy(ext_prop_data,
-		       usb_ext_prop_data_ptr(data, ext_prop->name_len),
-		       ext_prop->data_len);
-		/* unicode data reported to the host as "WCHAR"s */
-		switch (ext_prop->type) {
-		case USB_EXT_PROP_UNICODE:
-		case USB_EXT_PROP_UNICODE_ENV:
-		case USB_EXT_PROP_UNICODE_LINK:
-		case USB_EXT_PROP_UNICODE_MULTI:
-			ext_prop->data_len *= 2;
-			break;
-		}
-		ext_prop->data = ext_prop_data;
-
-		memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
-		       ext_prop->name_len);
-		/* property name reported to the host as "WCHAR"s */
-		ext_prop->name_len *= 2;
-		ext_prop->name = ext_prop_name;
-
-		t->os_desc->ext_prop_len +=
-			ext_prop->name_len + ext_prop->data_len + 14;
-		++t->os_desc->ext_prop_count;
-		list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
-	}
-		break;
-	default:
-		pr_vdebug("unknown descriptor: %d\n", type);
-	}
-
-	return length;
-}
-
-static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
-						struct usb_configuration *c)
-{
-	struct ffs_function *func = ffs_func_from_usb(f);
-	struct f_fs_opts *ffs_opts =
-		container_of(f->fi, struct f_fs_opts, func_inst);
-	int ret;
-
-	ENTER();
-
-	/*
-	 * Legacy gadget triggers binding in functionfs_ready_callback,
-	 * which already uses locking; taking the same lock here would
-	 * cause a deadlock.
-	 *
-	 * Configfs-enabled gadgets however do need ffs_dev_lock.
-	 */
-	if (!ffs_opts->no_configfs)
-		ffs_dev_lock();
-	ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
-	func->ffs = ffs_opts->dev->ffs_data;
-	if (!ffs_opts->no_configfs)
-		ffs_dev_unlock();
-	if (ret)
-		return ERR_PTR(ret);
-
-	func->conf = c;
-	func->gadget = c->cdev->gadget;
-
-	ffs_data_get(func->ffs);
-
-	/*
-	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
-	 * configurations are bound in sequence with list_for_each_entry,
-	 * in each configuration its functions are bound in sequence
-	 * with list_for_each_entry, so we assume no race condition
-	 * with regard to ffs_opts->bound access
-	 */
-	if (!ffs_opts->refcnt) {
-		ret = functionfs_bind(func->ffs, c->cdev);
-		if (ret)
-			return ERR_PTR(ret);
-	}
-	ffs_opts->refcnt++;
-	func->function.strings = func->ffs->stringtabs;
-
-	return ffs_opts;
-}
-
-static int _ffs_func_bind(struct usb_configuration *c,
-			  struct usb_function *f)
-{
-	struct ffs_function *func = ffs_func_from_usb(f);
-	struct ffs_data *ffs = func->ffs;
-
-	const int full = !!func->ffs->fs_descs_count;
-	const int high = gadget_is_dualspeed(func->gadget) &&
-		func->ffs->hs_descs_count;
-	const int super = gadget_is_superspeed(func->gadget) &&
-		func->ffs->ss_descs_count;
-
-	int fs_len, hs_len, ss_len, ret, i;
-
-	/* Make it a single chunk, less management later on */
-	vla_group(d);
-	vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
-	vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
-		full ? ffs->fs_descs_count + 1 : 0);
-	vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
-		high ? ffs->hs_descs_count + 1 : 0);
-	vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
-		super ? ffs->ss_descs_count + 1 : 0);
-	vla_item_with_sz(d, short, inums, ffs->interfaces_count);
-	vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
-			 c->cdev->use_os_string ? ffs->interfaces_count : 0);
-	vla_item_with_sz(d, char[16], ext_compat,
-			 c->cdev->use_os_string ? ffs->interfaces_count : 0);
-	vla_item_with_sz(d, struct usb_os_desc, os_desc,
-			 c->cdev->use_os_string ? ffs->interfaces_count : 0);
-	vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
-			 ffs->ms_os_descs_ext_prop_count);
-	vla_item_with_sz(d, char, ext_prop_name,
-			 ffs->ms_os_descs_ext_prop_name_len);
-	vla_item_with_sz(d, char, ext_prop_data,
-			 ffs->ms_os_descs_ext_prop_data_len);
-	vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
-	char *vlabuf;
-
-	ENTER();
-
-	/* Has descriptors only for speeds gadget does not support */
-	if (unlikely(!(full | high | super)))
-		return -ENOTSUPP;
-
-	/* Allocate a single chunk, less management later on */
-	vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
-	if (unlikely(!vlabuf))
-		return -ENOMEM;
-
-	ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
-	ffs->ms_os_descs_ext_prop_name_avail =
-		vla_ptr(vlabuf, d, ext_prop_name);
-	ffs->ms_os_descs_ext_prop_data_avail =
-		vla_ptr(vlabuf, d, ext_prop_data);
-
-	/* Copy descriptors  */
-	memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
-	       ffs->raw_descs_length);
-
-	memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
-	for (ret = ffs->eps_count; ret; --ret) {
-		struct ffs_ep *ptr;
-
-		ptr = vla_ptr(vlabuf, d, eps);
-		ptr[ret].num = -1;
-	}
-
-	/* Save pointers
-	 * d_eps == vlabuf, func->eps used to kfree vlabuf later
-	*/
-	func->eps             = vla_ptr(vlabuf, d, eps);
-	func->interfaces_nums = vla_ptr(vlabuf, d, inums);
-
-	/*
-	 * Go through all the endpoint descriptors and allocate
-	 * endpoints first, so that later we can rewrite the endpoint
-	 * numbers without worrying that it may be described later on.
-	 */
-	if (likely(full)) {
-		func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
-		fs_len = ffs_do_descs(ffs->fs_descs_count,
-				      vla_ptr(vlabuf, d, raw_descs),
-				      d_raw_descs__sz,
-				      __ffs_func_bind_do_descs, func);
-		if (unlikely(fs_len < 0)) {
-			ret = fs_len;
-			goto error;
-		}
-	} else {
-		fs_len = 0;
-	}
-
-	if (likely(high)) {
-		func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
-		hs_len = ffs_do_descs(ffs->hs_descs_count,
-				      vla_ptr(vlabuf, d, raw_descs) + fs_len,
-				      d_raw_descs__sz - fs_len,
-				      __ffs_func_bind_do_descs, func);
-		if (unlikely(hs_len < 0)) {
-			ret = hs_len;
-			goto error;
-		}
-	} else {
-		hs_len = 0;
-	}
-
-	if (likely(super)) {
-		func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
-		ss_len = ffs_do_descs(ffs->ss_descs_count,
-				vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
-				d_raw_descs__sz - fs_len - hs_len,
-				__ffs_func_bind_do_descs, func);
-		if (unlikely(ss_len < 0)) {
-			ret = ss_len;
-			goto error;
-		}
-	} else {
-		ss_len = 0;
-	}
-
-	/*
-	 * Now handle interface numbers allocation and interface and
-	 * endpoint numbers rewriting.  We can do that in one go
-	 * now.
-	 */
-	ret = ffs_do_descs(ffs->fs_descs_count +
-			   (high ? ffs->hs_descs_count : 0) +
-			   (super ? ffs->ss_descs_count : 0),
-			   vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
-			   __ffs_func_bind_do_nums, func);
-	if (unlikely(ret < 0))
-		goto error;
-
-	func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
-	if (c->cdev->use_os_string)
-		for (i = 0; i < ffs->interfaces_count; ++i) {
-			struct usb_os_desc *desc;
-
-			desc = func->function.os_desc_table[i].os_desc =
-				vla_ptr(vlabuf, d, os_desc) +
-				i * sizeof(struct usb_os_desc);
-			desc->ext_compat_id =
-				vla_ptr(vlabuf, d, ext_compat) + i * 16;
-			INIT_LIST_HEAD(&desc->ext_prop);
-		}
-	ret = ffs_do_os_descs(ffs->ms_os_descs_count,
-			      vla_ptr(vlabuf, d, raw_descs) +
-			      fs_len + hs_len + ss_len,
-			      d_raw_descs__sz - fs_len - hs_len - ss_len,
-			      __ffs_func_bind_do_os_desc, func);
-	if (unlikely(ret < 0))
-		goto error;
-	func->function.os_desc_n =
-		c->cdev->use_os_string ? ffs->interfaces_count : 0;
-
-	/* And we're done */
-	ffs_event_add(ffs, FUNCTIONFS_BIND);
-	return 0;
-
-error:
-	/* XXX Do we need to release all claimed endpoints here? */
-	return ret;
-}
-
-static int ffs_func_bind(struct usb_configuration *c,
-			 struct usb_function *f)
-{
-	struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
-
-	if (IS_ERR(ffs_opts))
-		return PTR_ERR(ffs_opts);
-
-	return _ffs_func_bind(c, f);
-}
-
-
-/* Other USB function hooks *************************************************/
-
-static int ffs_func_set_alt(struct usb_function *f,
-			    unsigned interface, unsigned alt)
-{
-	struct ffs_function *func = ffs_func_from_usb(f);
-	struct ffs_data *ffs = func->ffs;
-	int ret = 0, intf;
-
-	if (alt != (unsigned)-1) {
-		intf = ffs_func_revmap_intf(func, interface);
-		if (unlikely(intf < 0))
-			return intf;
-	}
-
-	if (ffs->func)
-		ffs_func_eps_disable(ffs->func);
-
-	if (ffs->state != FFS_ACTIVE)
-		return -ENODEV;
-
-	if (alt == (unsigned)-1) {
-		ffs->func = NULL;
-		ffs_event_add(ffs, FUNCTIONFS_DISABLE);
-		return 0;
-	}
-
-	ffs->func = func;
-	ret = ffs_func_eps_enable(func);
-	if (likely(ret >= 0))
-		ffs_event_add(ffs, FUNCTIONFS_ENABLE);
-	return ret;
-}
-
-static void ffs_func_disable(struct usb_function *f)
-{
-	ffs_func_set_alt(f, 0, (unsigned)-1);
-}
-
-static int ffs_func_setup(struct usb_function *f,
-			  const struct usb_ctrlrequest *creq)
-{
-	struct ffs_function *func = ffs_func_from_usb(f);
-	struct ffs_data *ffs = func->ffs;
-	unsigned long flags;
-	int ret;
-
-	ENTER();
-
-	pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
-	pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
-	pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
-	pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
-	pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
-
-	/*
-	 * Most requests directed to interface go through here
-	 * (notable exceptions are set/get interface) so we need to
-	 * handle them.  All other either handled by composite or
-	 * passed to usb_configuration->setup() (if one is set).  No
-	 * matter, we will handle requests directed to endpoint here
-	 * as well (as it's straightforward) but what to do with any
-	 * other request?
-	 */
-	if (ffs->state != FFS_ACTIVE)
-		return -ENODEV;
-
-	switch (creq->bRequestType & USB_RECIP_MASK) {
-	case USB_RECIP_INTERFACE:
-		ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
-		if (unlikely(ret < 0))
-			return ret;
-		break;
-
-	case USB_RECIP_ENDPOINT:
-		ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
-		if (unlikely(ret < 0))
-			return ret;
-		break;
-
-	default:
-		return -EOPNOTSUPP;
-	}
-
-	spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
-	ffs->ev.setup = *creq;
-	ffs->ev.setup.wIndex = cpu_to_le16(ret);
-	__ffs_event_add(ffs, FUNCTIONFS_SETUP);
-	spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
-
-	return 0;
-}
-
-static void ffs_func_suspend(struct usb_function *f)
-{
-	ENTER();
-	ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
-}
-
-static void ffs_func_resume(struct usb_function *f)
-{
-	ENTER();
-	ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
-}
-
-
-/* Endpoint and interface numbers reverse mapping ***************************/
-
-static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
-{
-	num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
-	return num ? num : -EDOM;
-}
-
-static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
-{
-	short *nums = func->interfaces_nums;
-	unsigned count = func->ffs->interfaces_count;
-
-	for (; count; --count, ++nums) {
-		if (*nums >= 0 && *nums == intf)
-			return nums - func->interfaces_nums;
-	}
-
-	return -EDOM;
-}
-
-
-/* Devices management *******************************************************/
-
-static LIST_HEAD(ffs_devices);
-
-static struct ffs_dev *_ffs_do_find_dev(const char *name)
-{
-	struct ffs_dev *dev;
-
-	list_for_each_entry(dev, &ffs_devices, entry) {
-		if (!dev->name || !name)
-			continue;
-		if (strcmp(dev->name, name) == 0)
-			return dev;
-	}
-
-	return NULL;
-}
-
-/*
- * ffs_lock must be taken by the caller of this function
- */
-static struct ffs_dev *_ffs_get_single_dev(void)
-{
-	struct ffs_dev *dev;
-
-	if (list_is_singular(&ffs_devices)) {
-		dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
-		if (dev->single)
-			return dev;
-	}
-
-	return NULL;
-}
-
-/*
- * ffs_lock must be taken by the caller of this function
- */
-static struct ffs_dev *_ffs_find_dev(const char *name)
-{
-	struct ffs_dev *dev;
-
-	dev = _ffs_get_single_dev();
-	if (dev)
-		return dev;
-
-	return _ffs_do_find_dev(name);
-}
-
-/* Configfs support *********************************************************/
-
-static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
-{
-	return container_of(to_config_group(item), struct f_fs_opts,
-			    func_inst.group);
-}
-
-static void ffs_attr_release(struct config_item *item)
-{
-	struct f_fs_opts *opts = to_ffs_opts(item);
-
-	usb_put_function_instance(&opts->func_inst);
-}
-
-static struct configfs_item_operations ffs_item_ops = {
-	.release	= ffs_attr_release,
-};
-
-static struct config_item_type ffs_func_type = {
-	.ct_item_ops	= &ffs_item_ops,
-	.ct_owner	= THIS_MODULE,
-};
-
-
-/* Function registration interface ******************************************/
-
-static void ffs_free_inst(struct usb_function_instance *f)
-{
-	struct f_fs_opts *opts;
-
-	opts = to_f_fs_opts(f);
-	ffs_dev_lock();
-	_ffs_free_dev(opts->dev);
-	ffs_dev_unlock();
-	kfree(opts);
-}
-
-#define MAX_INST_NAME_LEN	40
-
-static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
-{
-	struct f_fs_opts *opts;
-	char *ptr;
-	const char *tmp;
-	int name_len, ret;
-
-	name_len = strlen(name) + 1;
-	if (name_len > MAX_INST_NAME_LEN)
-		return -ENAMETOOLONG;
-
-	ptr = kstrndup(name, name_len, GFP_KERNEL);
-	if (!ptr)
-		return -ENOMEM;
-
-	opts = to_f_fs_opts(fi);
-	tmp = NULL;
-
-	ffs_dev_lock();
-
-	tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
-	ret = _ffs_name_dev(opts->dev, ptr);
-	if (ret) {
-		kfree(ptr);
-		ffs_dev_unlock();
-		return ret;
-	}
-	opts->dev->name_allocated = true;
-
-	ffs_dev_unlock();
-
-	kfree(tmp);
-
-	return 0;
-}
-
-static struct usb_function_instance *ffs_alloc_inst(void)
-{
-	struct f_fs_opts *opts;
-	struct ffs_dev *dev;
-
-	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
-	if (!opts)
-		return ERR_PTR(-ENOMEM);
-
-	opts->func_inst.set_inst_name = ffs_set_inst_name;
-	opts->func_inst.free_func_inst = ffs_free_inst;
-	ffs_dev_lock();
-	dev = _ffs_alloc_dev();
-	ffs_dev_unlock();
-	if (IS_ERR(dev)) {
-		kfree(opts);
-		return ERR_CAST(dev);
-	}
-	opts->dev = dev;
-	dev->opts = opts;
-
-	config_group_init_type_name(&opts->func_inst.group, "",
-				    &ffs_func_type);
-	return &opts->func_inst;
-}
-
-static void ffs_free(struct usb_function *f)
-{
-	kfree(ffs_func_from_usb(f));
-}
-
-static void ffs_func_unbind(struct usb_configuration *c,
-			    struct usb_function *f)
-{
-	struct ffs_function *func = ffs_func_from_usb(f);
-	struct ffs_data *ffs = func->ffs;
-	struct f_fs_opts *opts =
-		container_of(f->fi, struct f_fs_opts, func_inst);
-	struct ffs_ep *ep = func->eps;
-	unsigned count = ffs->eps_count;
-	unsigned long flags;
-
-	ENTER();
-	if (ffs->func == func) {
-		ffs_func_eps_disable(func);
-		ffs->func = NULL;
-	}
-
-	if (!--opts->refcnt)
-		functionfs_unbind(ffs);
-
-	/* cleanup after autoconfig */
-	spin_lock_irqsave(&func->ffs->eps_lock, flags);
-	do {
-		if (ep->ep && ep->req)
-			usb_ep_free_request(ep->ep, ep->req);
-		ep->req = NULL;
-		++ep;
-	} while (--count);
-	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
-	kfree(func->eps);
-	func->eps = NULL;
-	/*
-	 * eps, descriptors and interfaces_nums are allocated in the
-	 * same chunk so only one free is required.
-	 */
-	func->function.fs_descriptors = NULL;
-	func->function.hs_descriptors = NULL;
-	func->function.ss_descriptors = NULL;
-	func->interfaces_nums = NULL;
-
-	ffs_event_add(ffs, FUNCTIONFS_UNBIND);
-}
-
-static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
-{
-	struct ffs_function *func;
-
-	ENTER();
-
-	func = kzalloc(sizeof(*func), GFP_KERNEL);
-	if (unlikely(!func))
-		return ERR_PTR(-ENOMEM);
-
-	func->function.name    = "Function FS Gadget";
-
-	func->function.bind    = ffs_func_bind;
-	func->function.unbind  = ffs_func_unbind;
-	func->function.set_alt = ffs_func_set_alt;
-	func->function.disable = ffs_func_disable;
-	func->function.setup   = ffs_func_setup;
-	func->function.suspend = ffs_func_suspend;
-	func->function.resume  = ffs_func_resume;
-	func->function.free_func = ffs_free;
-
-	return &func->function;
-}
-
-/*
- * ffs_lock must be taken by the caller of this function
- */
-static struct ffs_dev *_ffs_alloc_dev(void)
-{
-	struct ffs_dev *dev;
-	int ret;
-
-	if (_ffs_get_single_dev())
-			return ERR_PTR(-EBUSY);
-
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
-		return ERR_PTR(-ENOMEM);
-
-	if (list_empty(&ffs_devices)) {
-		ret = functionfs_init();
-		if (ret) {
-			kfree(dev);
-			return ERR_PTR(ret);
-		}
-	}
-
-	list_add(&dev->entry, &ffs_devices);
-
-	return dev;
-}
-
-/*
- * ffs_lock must be taken by the caller of this function
- * The caller is responsible for "name" being available whenever f_fs needs it
- */
-static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
-{
-	struct ffs_dev *existing;
-
-	existing = _ffs_do_find_dev(name);
-	if (existing)
-		return -EBUSY;
-
-	dev->name = name;
-
-	return 0;
-}
-
-/*
- * The caller is responsible for "name" being available whenever f_fs needs it
- */
-int ffs_name_dev(struct ffs_dev *dev, const char *name)
-{
-	int ret;
-
-	ffs_dev_lock();
-	ret = _ffs_name_dev(dev, name);
-	ffs_dev_unlock();
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(ffs_name_dev);
-
-int ffs_single_dev(struct ffs_dev *dev)
-{
-	int ret;
-
-	ret = 0;
-	ffs_dev_lock();
-
-	if (!list_is_singular(&ffs_devices))
-		ret = -EBUSY;
-	else
-		dev->single = true;
-
-	ffs_dev_unlock();
-	return ret;
-}
-EXPORT_SYMBOL_GPL(ffs_single_dev);
-
-/*
- * ffs_lock must be taken by the caller of this function
- */
-static void _ffs_free_dev(struct ffs_dev *dev)
-{
-	list_del(&dev->entry);
-	if (dev->name_allocated)
-		kfree(dev->name);
-	kfree(dev);
-	if (list_empty(&ffs_devices))
-		functionfs_cleanup();
-}
-
-static void *ffs_acquire_dev(const char *dev_name)
-{
-	struct ffs_dev *ffs_dev;
-
-	ENTER();
-	ffs_dev_lock();
-
-	ffs_dev = _ffs_find_dev(dev_name);
-	if (!ffs_dev)
-		ffs_dev = ERR_PTR(-ENOENT);
-	else if (ffs_dev->mounted)
-		ffs_dev = ERR_PTR(-EBUSY);
-	else if (ffs_dev->ffs_acquire_dev_callback &&
-	    ffs_dev->ffs_acquire_dev_callback(ffs_dev))
-		ffs_dev = ERR_PTR(-ENOENT);
-	else
-		ffs_dev->mounted = true;
-
-	ffs_dev_unlock();
-	return ffs_dev;
-}
-
-static void ffs_release_dev(struct ffs_data *ffs_data)
-{
-	struct ffs_dev *ffs_dev;
-
-	ENTER();
-	ffs_dev_lock();
-
-	ffs_dev = ffs_data->private_data;
-	if (ffs_dev) {
-		ffs_dev->mounted = false;
-
-		if (ffs_dev->ffs_release_dev_callback)
-			ffs_dev->ffs_release_dev_callback(ffs_dev);
-	}
-
-	ffs_dev_unlock();
-}
-
-static int ffs_ready(struct ffs_data *ffs)
-{
-	struct ffs_dev *ffs_obj;
-	int ret = 0;
-
-	ENTER();
-	ffs_dev_lock();
-
-	ffs_obj = ffs->private_data;
-	if (!ffs_obj) {
-		ret = -EINVAL;
-		goto done;
-	}
-	if (WARN_ON(ffs_obj->desc_ready)) {
-		ret = -EBUSY;
-		goto done;
-	}
-
-	ffs_obj->desc_ready = true;
-	ffs_obj->ffs_data = ffs;
-
-	if (ffs_obj->ffs_ready_callback)
-		ret = ffs_obj->ffs_ready_callback(ffs);
-
-done:
-	ffs_dev_unlock();
-	return ret;
-}
-
-static void ffs_closed(struct ffs_data *ffs)
-{
-	struct ffs_dev *ffs_obj;
-
-	ENTER();
-	ffs_dev_lock();
-
-	ffs_obj = ffs->private_data;
-	if (!ffs_obj)
-		goto done;
-
-	ffs_obj->desc_ready = false;
-
-	if (ffs_obj->ffs_closed_callback)
-		ffs_obj->ffs_closed_callback(ffs);
-
-	if (!ffs_obj->opts || ffs_obj->opts->no_configfs
-	    || !ffs_obj->opts->func_inst.group.cg_item.ci_parent)
-		goto done;
-
-	unregister_gadget_item(ffs_obj->opts->
-			       func_inst.group.cg_item.ci_parent->ci_parent);
-done:
-	ffs_dev_unlock();
-}
-
-/* Misc helper functions ****************************************************/
-
-static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
-{
-	return nonblock
-		? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
-		: mutex_lock_interruptible(mutex);
-}
-
-static char *ffs_prepare_buffer(const char __user *buf, size_t len)
-{
-	char *data;
-
-	if (unlikely(!len))
-		return NULL;
-
-	data = kmalloc(len, GFP_KERNEL);
-	if (unlikely(!data))
-		return ERR_PTR(-ENOMEM);
-
-	if (unlikely(__copy_from_user(data, buf, len))) {
-		kfree(data);
-		return ERR_PTR(-EFAULT);
-	}
-
-	pr_vdebug("Buffer from user space:\n");
-	ffs_dump_mem("", data, len);
-
-	return data;
-}
-
-DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Michal Nazarewicz");