Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 2442 insertions, 0 deletions

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
new file mode 100644
index 00000000000..d69eccf5f19
--- /dev/null
+++ b/drivers/usb/gadget/f_fs.c
@@ -0,0 +1,2442 @@
+/*
+ * f_fs.c -- user mode filesystem api for usb composite funtcion controllers
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ *
+ * Based on inode.c (GadgetFS):
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+/* #define DEBUG */
+/* #define VERBOSE_DEBUG */
+
+#include <linux/blkdev.h>
+#include <linux/pagemap.h>
+#include <asm/unaligned.h>
+#include <linux/smp_lock.h>
+
+#include <linux/usb/composite.h>
+#include <linux/usb/functionfs.h>
+
+
+#define FUNCTIONFS_MAGIC	0xa647361 /* Chosen by a honest dice roll ;) */
+
+
+/* Debuging *****************************************************************/
+
+#define ffs_printk(level, fmt, args...) printk(level "f_fs: " fmt "\n", ## args)
+
+#define FERR(...)  ffs_printk(KERN_ERR,  __VA_ARGS__)
+#define FINFO(...) ffs_printk(KERN_INFO, __VA_ARGS__)
+
+#ifdef DEBUG
+#  define FDBG(...) ffs_printk(KERN_DEBUG, __VA_ARGS__)
+#else
+#  define FDBG(...) do { } while (0)
+#endif /* DEBUG */
+
+#ifdef VERBOSE_DEBUG
+#  define FVDBG FDBG
+#else
+#  define FVDBG(...) do { } while (0)
+#endif /* VERBOSE_DEBUG */
+
+#define ENTER()    FVDBG("%s()", __func__)
+
+#ifdef VERBOSE_DEBUG
+#  define ffs_dump_mem(prefix, ptr, len) \
+	print_hex_dump_bytes("f_fs" prefix ": ", DUMP_PREFIX_NONE, ptr, len)
+#else
+#  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
+#endif
+
+
+/* The data structure and setup file ****************************************/
+
+enum ffs_state {
+	/* Waiting for descriptors and strings. */
+	/* In this state no open(2), read(2) or write(2) on epfiles
+	 * may succeed (which should not be the problem as there
+	 * should be no such files opened in the firts place). */
+	FFS_READ_DESCRIPTORS,
+	FFS_READ_STRINGS,
+
+	/* We've got descriptors and strings.  We are or have called
+	 * functionfs_ready_callback().  functionfs_bind() may have
+	 * been called but we don't know. */
+	/* This is the only state in which operations on epfiles may
+	 * succeed. */
+	FFS_ACTIVE,
+
+	/* All endpoints have been closed.  This state is also set if
+	 * we encounter an unrecoverable error.  The only
+	 * unrecoverable error is situation when after reading strings
+	 * from user space we fail to initialise EP files or
+	 * functionfs_ready_callback() returns with error (<0). */
+	/* In this state no open(2), read(2) or write(2) (both on ep0
+	 * as well as epfile) may succeed (at this point epfiles are
+	 * unlinked and all closed so this is not a problem; ep0 is
+	 * also closed but ep0 file exists and so open(2) on ep0 must
+	 * fail). */
+	FFS_CLOSING
+};
+
+
+enum ffs_setup_state {
+	/* There is no setup request pending. */
+	FFS_NO_SETUP,
+	/* User has read events and there was a setup request event
+	 * there.  The next read/write on ep0 will handle the
+	 * request. */
+	FFS_SETUP_PENDING,
+	/* There was event pending but before user space handled it
+	 * some other event was introduced which canceled existing
+	 * setup.  If this state is set read/write on ep0 return
+	 * -EIDRM.  This state is only set when adding event. */
+	FFS_SETUP_CANCELED
+};
+
+
+
+struct ffs_epfile;
+struct ffs_function;
+
+struct ffs_data {
+	struct usb_gadget		*gadget;
+
+	/* Protect access read/write operations, only one read/write
+	 * at a time.  As a consequence protects ep0req and company.
+	 * While setup request is being processed (queued) this is
+	 * held. */
+	struct mutex			mutex;
+
+	/* Protect access to enpoint related structures (basically
+	 * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
+	 * endpint zero. */
+	spinlock_t			eps_lock;
+
+	/* XXX REVISIT do we need our own request? Since we are not
+	 * handling setup requests immidiatelly user space may be so
+	 * slow that another setup will be sent to the gadget but this
+	 * time not to us but another function and then there could be
+	 * a race.  Is taht the case? Or maybe we can use cdev->req
+	 * after all, maybe we just need some spinlock for that? */
+	struct usb_request		*ep0req;		/* P: mutex */
+	struct completion		ep0req_completion;	/* P: mutex */
+	int				ep0req_status;		/* P: mutex */
+
+	/* reference counter */
+	atomic_t			ref;
+	/* how many files are opened (EP0 and others) */
+	atomic_t			opened;
+
+	/* EP0 state */
+	enum ffs_state			state;
+
+	/*
+	 * Possible transations:
+	 * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
+	 *               happens only in ep0 read which is P: mutex
+	 * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
+	 *               happens only in ep0 i/o  which is P: mutex
+	 * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
+	 * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
+	 */
+	enum ffs_setup_state		setup_state;
+
+#define FFS_SETUP_STATE(ffs)					\
+	((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,	\
+				       FFS_SETUP_CANCELED, FFS_NO_SETUP))
+
+	/* Events & such. */
+	struct {
+		u8				types[4];
+		unsigned short			count;
+		/* XXX REVISIT need to update it in some places, or do we? */
+		unsigned short			can_stall;
+		struct usb_ctrlrequest		setup;
+
+		wait_queue_head_t		waitq;
+	} ev; /* the whole structure, P: ev.waitq.lock */
+
+	/* Flags */
+	unsigned long			flags;
+#define FFS_FL_CALL_CLOSED_CALLBACK 0
+#define FFS_FL_BOUND                1
+
+	/* Active function */
+	struct ffs_function		*func;
+
+	/* Device name, write once when file system is mounted.
+	 * Intendet for user to read if she wants. */
+	const char			*dev_name;
+	/* Private data for our user (ie. gadget).  Managed by
+	 * user. */
+	void				*private_data;
+
+	/* filled by __ffs_data_got_descs() */
+	/* real descriptors are 16 bytes after raw_descs (so you need
+	 * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
+	 * first full speed descriptor).  raw_descs_length and
+	 * raw_fs_descs_length do not have those 16 bytes added. */
+	const void			*raw_descs;
+	unsigned			raw_descs_length;
+	unsigned			raw_fs_descs_length;
+	unsigned			fs_descs_count;
+	unsigned			hs_descs_count;
+
+	unsigned short			strings_count;
+	unsigned short			interfaces_count;
+	unsigned short			eps_count;
+	unsigned short			_pad1;
+
+	/* filled by __ffs_data_got_strings() */
+	/* ids in stringtabs are set in functionfs_bind() */
+	const void			*raw_strings;
+	struct usb_gadget_strings	**stringtabs;
+
+	/* File system's super block, write once when file system is mounted. */
+	struct super_block		*sb;
+
+	/* File permissions, written once when fs is mounted*/
+	struct ffs_file_perms {
+		umode_t				mode;
+		uid_t				uid;
+		gid_t				gid;
+	}				file_perms;
+
+	/* The endpoint files, filled by ffs_epfiles_create(),
+	 * destroyed by ffs_epfiles_destroy(). */
+	struct ffs_epfile		*epfiles;
+};
+
+/* 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 ownerrship 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 void ffs_func_free(struct ffs_function *func);
+
+
+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 void ffs_func_unbind(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 */
+	struct usb_endpoint_descriptor	*descs[2];
+
+	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;
+};
+
+
+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);
+
+
+/* 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;
+
+	INIT_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 ffs->ep0req_status;
+}
+
+static int __ffs_ep0_stall(struct ffs_data *ffs)
+{
+	if (ffs->ev.can_stall) {
+		FVDBG("ep0 stall\n");
+		usb_ep_set_halt(ffs->gadget->ep0);
+		ffs->setup_state = FFS_NO_SETUP;
+		return -EL2HLT;
+	} else {
+		FDBG("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(ffs) == FFS_SETUP_CANCELED)
+		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 (unlikely(IS_ERR(data))) {
+			ret = PTR_ERR(data);
+			break;
+		}
+
+		/* Handle data */
+		if (ffs->state == FFS_READ_DESCRIPTORS) {
+			FINFO("read descriptors");
+			ret = __ffs_data_got_descs(ffs, data, len);
+			if (unlikely(ret < 0))
+				break;
+
+			ffs->state = FFS_READ_STRINGS;
+			ret = len;
+		} else {
+			FINFO("read strings");
+			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 = functionfs_ready_callback(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(ffs)) {
+		case FFS_SETUP_CANCELED:
+			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 (unlikely(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_CANCELED 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(ffs) == FFS_SETUP_CANCELED) {
+			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(ffs) == FFS_SETUP_CANCELED)
+		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(ffs)) {
+	case FFS_SETUP_CANCELED:
+		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 (unlikely(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(ffs) == FFS_SETUP_CANCELED) {
+			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->ops->ioctl) {
+		lock_kernel();
+		ret = gadget->ops->ioctl(gadget, code, value);
+		unlock_kernel();
+	} else {
+		ret = -ENOTTY;
+	}
+
+	return ret;
+}
+
+
+static const struct file_operations ffs_ep0_operations = {
+	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+
+	.open =		ffs_ep0_open,
+	.write =	ffs_ep0_write,
+	.read =		ffs_ep0_read,
+	.release =	ffs_ep0_release,
+	.unlocked_ioctl =	ffs_ep0_ioctl,
+};
+
+
+/* "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 ssize_t ffs_epfile_io(struct file *file,
+			     char __user *buf, size_t len, int read)
+{
+	struct ffs_epfile *epfile = file->private_data;
+	struct ffs_ep *ep;
+	char *data = NULL;
+	ssize_t ret;
+	int halt;
+
+	goto first_try;
+	do {
+		spin_unlock_irq(&epfile->ffs->eps_lock);
+		mutex_unlock(&epfile->mutex);
+
+first_try:
+		/* 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;
+			}
+
+			if (unlikely(wait_event_interruptible
+				     (epfile->wait, (ep = epfile->ep)))) {
+				ret = -EINTR;
+				goto error;
+			}
+		}
+
+		/* Do we halt? */
+		halt = !read == !epfile->in;
+		if (halt && epfile->isoc) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		/* Allocate & copy */
+		if (!halt && !data) {
+			data = kzalloc(len, GFP_KERNEL);
+			if (unlikely(!data))
+				return -ENOMEM;
+
+			if (!read &&
+			    unlikely(__copy_from_user(data, buf, 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;
+
+		/* We're called from user space, we can use _irq rather then
+		 * _irqsave */
+		spin_lock_irq(&epfile->ffs->eps_lock);
+
+		/* While we were acquiring mutex endpoint got disabled
+		 * or changed? */
+	} while (unlikely(epfile->ep != ep));
+
+	/* Halt */
+	if (unlikely(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 */
+		DECLARE_COMPLETION_ONSTACK(done);
+
+		struct usb_request *req = ep->req;
+		req->context  = &done;
+		req->complete = ffs_epfile_io_complete;
+		req->buf      = data;
+		req->length   = len;
+
+		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 {
+			ret = ep->status;
+			if (read && ret > 0 &&
+			    unlikely(copy_to_user(buf, data, ret)))
+				ret = -EFAULT;
+		}
+	}
+
+	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)
+{
+	ENTER();
+
+	return ffs_epfile_io(file, (char __user *)buf, len, 0);
+}
+
+static ssize_t
+ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
+{
+	ENTER();
+
+	return ffs_epfile_io(file, buf, len, 1);
+}
+
+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_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 = {
+	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+
+	.open =		ffs_epfile_open,
+	.write =	ffs_epfile_write,
+	.read =		ffs_epfile_read,
+	.release =	ffs_epfile_release,
+	.unlocked_ioctl =	ffs_epfile_ioctl,
+};
+
+
+
+/* File system and super block operations ***********************************/
+
+/*
+ * Mounting the filesystem 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_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;
+};
+
+static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
+{
+	struct ffs_sb_fill_data *data = _data;
+	struct inode	*inode;
+	struct dentry	*d;
+	struct ffs_data	*ffs;
+
+	ENTER();
+
+	/* Initialize data */
+	ffs = ffs_data_new();
+	if (unlikely(!ffs))
+		goto enomem0;
+
+	ffs->sb              = sb;
+	ffs->dev_name        = data->dev_name;
+	ffs->file_perms      = data->perms;
+
+	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);
+	if (unlikely(!inode))
+		goto enomem1;
+	d = d_alloc_root(inode);
+	if (unlikely(!d))
+		goto enomem2;
+	sb->s_root = d;
+
+	/* EP0 file */
+	if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
+					 &ffs_ep0_operations, NULL)))
+		goto enomem3;
+
+	return 0;
+
+enomem3:
+	dput(d);
+enomem2:
+	iput(inode);
+enomem1:
+	ffs_data_put(ffs);
+enomem0:
+	return -ENOMEM;
+}
+
+
+static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
+{
+	ENTER();
+
+	if (!opts || !*opts)
+		return 0;
+
+	for (;;) {
+		char *end, *eq, *comma;
+		unsigned long value;
+
+		/* Option limit */
+		comma = strchr(opts, ',');
+		if (comma)
+			*comma = 0;
+
+		/* Value limit */
+		eq = strchr(opts, '=');
+		if (unlikely(!eq)) {
+			FERR("'=' missing in %s", opts);
+			return -EINVAL;
+		}
+		*eq = 0;
+
+		/* Parse value */
+		value = simple_strtoul(eq + 1, &end, 0);
+		if (unlikely(*end != ',' && *end != 0)) {
+			FERR("%s: invalid value: %s", 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 = value;
+			else if (!memcmp(opts, "gid", 3))
+				data->perms.gid = value;
+			else
+				goto invalid;
+			break;
+
+		default:
+invalid:
+			FERR("%s: invalid option", opts);
+			return -EINVAL;
+		}
+
+		/* Next iteration */
+		if (!comma)
+			break;
+		opts = comma + 1;
+	}
+
+	return 0;
+}
+
+
+/* "mount -t functionfs dev_name /dev/function" ends up here */
+
+static int
+ffs_fs_get_sb(struct file_system_type *t, int flags,
+	      const char *dev_name, void *opts, struct vfsmount *mnt)
+{
+	struct ffs_sb_fill_data data = {
+		.perms = {
+			.mode = S_IFREG | 0600,
+			.uid = 0,
+			.gid = 0
+		},
+		.root_mode = S_IFDIR | 0500,
+	};
+	int ret;
+
+	ENTER();
+
+	ret = functionfs_check_dev_callback(dev_name);
+	if (unlikely(ret < 0))
+		return ret;
+
+	ret = ffs_fs_parse_opts(&data, opts);
+	if (unlikely(ret < 0))
+		return ret;
+
+	data.dev_name = dev_name;
+	return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
+}
+
+static void
+ffs_fs_kill_sb(struct super_block *sb)
+{
+	void *ptr;
+
+	ENTER();
+
+	kill_litter_super(sb);
+	ptr = xchg(&sb->s_fs_info, NULL);
+	if (ptr)
+		ffs_data_put(ptr);
+}
+
+static struct file_system_type ffs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "functionfs",
+	.get_sb		= ffs_fs_get_sb,
+	.kill_sb	= ffs_fs_kill_sb,
+};
+
+
+
+/* Driver's main init/cleanup functions *************************************/
+
+
+static int functionfs_init(void)
+{
+	int ret;
+
+	ENTER();
+
+	ret = register_filesystem(&ffs_fs_type);
+	if (likely(!ret))
+		FINFO("file system registered");
+	else
+		FERR("failed registering file system (%d)"