diff --git a/tools/usb/ffs-test.c b/tools/usb/ffs-test.c
new file mode 100644
index 0000000..bbe2e3a
--- /dev/null
+++ b/tools/usb/ffs-test.c
@@ -0,0 +1,554 @@
+/*
+ * ffs-test.c.c -- user mode filesystem api for usb composite function
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ *
+ * 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
+ */
+
+/* $(CROSS_COMPILE)cc -Wall -Wextra -g -o ffs-test ffs-test.c -lpthread */
+
+
+#define _BSD_SOURCE /* for endian.h */
+
+#include <endian.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <linux/usb/functionfs.h>
+
+
+/******************** Little Endian Handling ********************************/
+
+#define cpu_to_le16(x)  htole16(x)
+#define cpu_to_le32(x)  htole32(x)
+#define le32_to_cpu(x)  le32toh(x)
+#define le16_to_cpu(x)  le16toh(x)
+
+static inline __u16 get_unaligned_le16(const void *_ptr)
+{
+	const __u8 *ptr = _ptr;
+	return ptr[0] | (ptr[1] << 8);
+}
+
+static inline __u32 get_unaligned_le32(const void *_ptr)
+{
+	const __u8 *ptr = _ptr;
+	return ptr[0] | (ptr[1] << 8) | (ptr[2] << 16) | (ptr[3] << 24);
+}
+
+static inline void put_unaligned_le16(__u16 val, void *_ptr)
+{
+	__u8 *ptr = _ptr;
+	*ptr++ = val;
+	*ptr++ = val >> 8;
+}
+
+static inline void put_unaligned_le32(__u32 val, void *_ptr)
+{
+	__u8 *ptr = _ptr;
+	*ptr++ = val;
+	*ptr++ = val >>  8;
+	*ptr++ = val >> 16;
+	*ptr++ = val >> 24;
+}
+
+
+/******************** Messages and Errors ***********************************/
+
+static const char argv0[] = "ffs-test";
+
+static unsigned verbosity = 7;
+
+static void _msg(unsigned level, const char *fmt, ...)
+{
+	if (level < 2)
+		level = 2;
+	else if (level > 7)
+		level = 7;
+
+	if (level <= verbosity) {
+		static const char levels[8][6] = {
+			[2] = "crit:",
+			[3] = "err: ",
+			[4] = "warn:",
+			[5] = "note:",
+			[6] = "info:",
+			[7] = "dbg: "
+		};
+
+		int _errno = errno;
+		va_list ap;
+
+		fprintf(stderr, "%s: %s ", argv0, levels[level]);
+		va_start(ap, fmt);
+		vfprintf(stderr, fmt, ap);
+		va_end(ap);
+
+		if (fmt[strlen(fmt) - 1] != '\n') {
+			char buffer[128];
+			strerror_r(_errno, buffer, sizeof buffer);
+			fprintf(stderr, ": (-%d) %s\n", _errno, buffer);
+		}
+
+		fflush(stderr);
+	}
+}
+
+#define die(...)  (_msg(2, __VA_ARGS__), exit(1))
+#define err(...)   _msg(3, __VA_ARGS__)
+#define warn(...)  _msg(4, __VA_ARGS__)
+#define note(...)  _msg(5, __VA_ARGS__)
+#define info(...)  _msg(6, __VA_ARGS__)
+#define debug(...) _msg(7, __VA_ARGS__)
+
+#define die_on(cond, ...) do { \
+	if (cond) \
+		die(__VA_ARGS__); \
+	} while (0)
+
+
+/******************** Descriptors and Strings *******************************/
+
+static const struct {
+	struct usb_functionfs_descs_head header;
+	struct {
+		struct usb_interface_descriptor intf;
+		struct usb_endpoint_descriptor_no_audio sink;
+		struct usb_endpoint_descriptor_no_audio source;
+	} __attribute__((packed)) fs_descs, hs_descs;
+} __attribute__((packed)) descriptors = {
+	.header = {
+		.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC),
+		.length = cpu_to_le32(sizeof descriptors),
+		.fs_count = 3,
+		.hs_count = 3,
+	},
+	.fs_descs = {
+		.intf = {
+			.bLength = sizeof descriptors.fs_descs.intf,
+			.bDescriptorType = USB_DT_INTERFACE,
+			.bNumEndpoints = 2,
+			.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+			.iInterface = 1,
+		},
+		.sink = {
+			.bLength = sizeof descriptors.fs_descs.sink,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 1 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			/* .wMaxPacketSize = autoconfiguration (kernel) */
+		},
+		.source = {
+			.bLength = sizeof descriptors.fs_descs.source,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 2 | USB_DIR_OUT,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			/* .wMaxPacketSize = autoconfiguration (kernel) */
+		},
+	},
+	.hs_descs = {
+		.intf = {
+			.bLength = sizeof descriptors.fs_descs.intf,
+			.bDescriptorType = USB_DT_INTERFACE,
+			.bNumEndpoints = 2,
+			.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+			.iInterface = 1,
+		},
+		.sink = {
+			.bLength = sizeof descriptors.hs_descs.sink,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 1 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = cpu_to_le16(512),
+		},
+		.source = {
+			.bLength = sizeof descriptors.hs_descs.source,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 2 | USB_DIR_OUT,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = cpu_to_le16(512),
+			.bInterval = 1, /* NAK every 1 uframe */
+		},
+	},
+};
+
+
+#define STR_INTERFACE_ "Source/Sink"
+
+static const struct {
+	struct usb_functionfs_strings_head header;
+	struct {
+		__le16 code;
+		const char str1[sizeof STR_INTERFACE_];
+	} __attribute__((packed)) lang0;
+} __attribute__((packed)) strings = {
+	.header = {
+		.magic = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
+		.length = cpu_to_le32(sizeof strings),
+		.str_count = cpu_to_le32(1),
+		.lang_count = cpu_to_le32(1),
+	},
+	.lang0 = {
+		cpu_to_le16(0x0409), /* en-us */
+		STR_INTERFACE_,
+	},
+};
+
+#define STR_INTERFACE strings.lang0.str1
+
+
+/******************** Files and Threads Handling ****************************/
+
+struct thread;
+
+static ssize_t read_wrap(struct thread *t, void *buf, size_t nbytes);
+static ssize_t write_wrap(struct thread *t, const void *buf, size_t nbytes);
+static ssize_t ep0_consume(struct thread *t, const void *buf, size_t nbytes);
+static ssize_t fill_in_buf(struct thread *t, void *buf, size_t nbytes);
+static ssize_t empty_out_buf(struct thread *t, const void *buf, size_t nbytes);
+
+
+static struct thread {
+	const char *const filename;
+	size_t buf_size;
+
+	ssize_t (*in)(struct thread *, void *, size_t);
+	const char *const in_name;
+
+	ssize_t (*out)(struct thread *, const void *, size_t);
+	const char *const out_name;
+
+	int fd;
+	pthread_t id;
+	void *buf;
+	ssize_t status;
+} threads[] = {
+	{
+		"ep0", 4 * sizeof(struct usb_functionfs_event),
+		read_wrap, NULL,
+		ep0_consume, "<consume>",
+		0, 0, NULL, 0
+	},
+	{
+		"ep1", 8 * 1024,
+		fill_in_buf, "<in>",
+		write_wrap, NULL,
+		0, 0, NULL, 0
+	},
+	{
+		"ep2", 8 * 1024,
+		read_wrap, NULL,
+		empty_out_buf, "<out>",
+		0, 0, NULL, 0
+	},
+};
+
+
+static void init_thread(struct thread *t)
+{
+	t->buf = malloc(t->buf_size);
+	die_on(!t->buf, "malloc");
+
+	t->fd = open(t->filename, O_RDWR);
+	die_on(t->fd < 0, "%s", t->filename);
+}
+
+static void cleanup_thread(void *arg)
+{
+	struct thread *t = arg;
+	int ret, fd;
+
+	fd = t->fd;
+	if (t->fd < 0)
+		return;
+	t->fd = -1;
+
+	/* test the FIFO ioctls (non-ep0 code paths) */
+	if (t != threads) {
+		ret = ioctl(fd, FUNCTIONFS_FIFO_STATUS);
+		if (ret < 0) {
+			/* ENODEV reported after disconnect */
+			if (errno != ENODEV)
+				err("%s: get fifo status", t->filename);
+		} else if (ret) {
+			warn("%s: unclaimed = %d\n", t->filename, ret);
+			if (ioctl(fd, FUNCTIONFS_FIFO_FLUSH) < 0)
+				err("%s: fifo flush", t->filename);
+		}
+	}
+
+	if (close(fd) < 0)
+		err("%s: close", t->filename);
+
+	free(t->buf);
+	t->buf = NULL;
+}
+
+static void *start_thread_helper(void *arg)
+{
+	const char *name, *op, *in_name, *out_name;
+	struct thread *t = arg;
+	ssize_t ret;
+
+	info("%s: starts\n", t->filename);
+	in_name = t->in_name ? t->in_name : t->filename;
+	out_name = t->out_name ? t->out_name : t->filename;
+
+	pthread_cleanup_push(cleanup_thread, arg);
+
+	for (;;) {
+		pthread_testcancel();
+
+		ret = t->in(t, t->buf, t->buf_size);
+		if (ret > 0) {
+			ret = t->out(t, t->buf, t->buf_size);
+			name = out_name;
+			op = "write";
+		} else {
+			name = in_name;
+			op = "read";
+		}
+
+		if (ret > 0) {
+			/* nop */
+		} else if (!ret) {
+			debug("%s: %s: EOF", name, op);
+			break;
+		} else if (errno == EINTR || errno == EAGAIN) {
+			debug("%s: %s", name, op);
+		} else {
+			warn("%s: %s", name, op);
+			break;
+		}
+	}
+
+	pthread_cleanup_pop(1);
+
+	t->status = ret;
+	info("%s: ends\n", t->filename);
+	return NULL;
+}
+
+static void start_thread(struct thread *t)
+{
+	debug("%s: starting\n", t->filename);
+
+	die_on(pthread_create(&t->id, NULL, start_thread_helper, t) < 0,
+	       "pthread_create(%s)", t->filename);
+}
+
+static void join_thread(struct thread *t)
+{
+	int ret = pthread_join(t->id, NULL);
+
+	if (ret < 0)
+		err("%s: joining thread", t->filename);
+	else
+		debug("%s: joined\n", t->filename);
+}
+
+
+static ssize_t read_wrap(struct thread *t, void *buf, size_t nbytes)
+{
+	return read(t->fd, buf, nbytes);
+}
+
+static ssize_t write_wrap(struct thread *t, const void *buf, size_t nbytes)
+{
+	return write(t->fd, buf, nbytes);
+}
+
+
+/******************** Empty/Fill buffer routines ****************************/
+
+/* 0 -- stream of zeros, 1 -- i % 63, 2 -- pipe */
+enum pattern { PAT_ZERO, PAT_SEQ, PAT_PIPE };
+static enum pattern pattern;
+
+static ssize_t
+fill_in_buf(struct thread *ignore, void *buf, size_t nbytes)
+{
+	size_t i;
+	__u8 *p;
+
+	(void)ignore;
+
+	switch (pattern) {
+	case PAT_ZERO:
+		memset(buf, 0, nbytes);
+		break;
+
+	case PAT_SEQ:
+		for (p = buf, i = 0; i < nbytes; ++i, ++p)
+			*p = i % 63;
+		break;
+
+	case PAT_PIPE:
+		return fread(buf, 1, nbytes, stdin);
+	}
+
+	return nbytes;
+}
+
+static ssize_t
+empty_out_buf(struct thread *ignore, const void *buf, size_t nbytes)
+{
+	const __u8 *p;
+	__u8 expected;
+	ssize_t ret;
+	size_t len;
+
+	(void)ignore;
+
+	switch (pattern) {
+	case PAT_ZERO:
+		expected = 0;
+		for (p = buf, len = 0; len < nbytes; ++p, ++len)
+			if (*p)
+				goto invalid;
+		break;
+
+	case PAT_SEQ:
+		for (p = buf, len = 0; len < nbytes; ++p, ++len)
+			if (*p != len % 63) {
+				expected = len % 63;
+				goto invalid;
+			}
+		break;
+
+	case PAT_PIPE:
+		ret = fwrite(buf, nbytes, 1, stdout);
+		if (ret > 0)
+			fflush(stdout);
+		break;
+
+invalid:
+		err("bad OUT byte %zd, expected %02x got %02x\n",
+		    len, expected, *p);
+		for (p = buf, len = 0; len < nbytes; ++p, ++len) {
+			if (0 == (len % 32))
+				fprintf(stderr, "%4d:", len);
+			fprintf(stderr, " %02x", *p);
+			if (31 == (len % 32))
+				fprintf(stderr, "\n");
+		}
+		fflush(stderr);
+		errno = EILSEQ;
+		return -1;
+	}
+
+	return len;
+}
+
+
+/******************** Endpoints routines ************************************/
+
+static void handle_setup(const struct usb_ctrlrequest *setup)
+{
+	printf("bRequestType = %d\n", setup->bRequestType);
+	printf("bRequest     = %d\n", setup->bRequest);
+	printf("wValue       = %d\n", le16_to_cpu(setup->wValue));
+	printf("wIndex       = %d\n", le16_to_cpu(setup->wIndex));
+	printf("wLength      = %d\n", le16_to_cpu(setup->wLength));
+}
+
+static ssize_t
+ep0_consume(struct thread *ignore, const void *buf, size_t nbytes)
+{
+	static const char *const names[] = {
+		[FUNCTIONFS_BIND] = "BIND",
+		[FUNCTIONFS_UNBIND] = "UNBIND",
+		[FUNCTIONFS_ENABLE] = "ENABLE",
+		[FUNCTIONFS_DISABLE] = "DISABLE",
+		[FUNCTIONFS_SETUP] = "SETUP",
+		[FUNCTIONFS_SUSPEND] = "SUSPEND",
+		[FUNCTIONFS_RESUME] = "RESUME",
+	};
+
+	const struct usb_functionfs_event *event = buf;
+	size_t n;
+
+	(void)ignore;
+
+	for (n = nbytes / sizeof *event; n; --n, ++event)
+		switch (event->type) {
+		case FUNCTIONFS_BIND:
+		case FUNCTIONFS_UNBIND:
+		case FUNCTIONFS_ENABLE:
+		case FUNCTIONFS_DISABLE:
+		case FUNCTIONFS_SETUP:
+		case FUNCTIONFS_SUSPEND:
+		case FUNCTIONFS_RESUME:
+			printf("Event %s\n", names[event->type]);
+			if (event->type == FUNCTIONFS_SETUP)
+				handle_setup(&event->u.setup);
+			break;
+
+		default:
+			printf("Event %03u (unknown)\n", event->type);
+		}
+
+	return nbytes;
+}
+
+static void ep0_init(struct thread *t)
+{
+	ssize_t ret;
+
+	info("%s: writing descriptors\n", t->filename);
+	ret = write(t->fd, &descriptors, sizeof descriptors);
+	die_on(ret < 0, "%s: write: descriptors", t->filename);
+
+	info("%s: writing strings\n", t->filename);
+	ret = write(t->fd, &strings, sizeof strings);
+	die_on(ret < 0, "%s: write: strings", t->filename);
+}
+
+
+/******************** Main **************************************************/
+
+int main(void)
+{
+	unsigned i;
+
+	/* XXX TODO: Argument parsing missing */
+
+	init_thread(threads);
+	ep0_init(threads);
+
+	for (i = 1; i < sizeof threads / sizeof *threads; ++i)
+		init_thread(threads + i);
+
+	for (i = 1; i < sizeof threads / sizeof *threads; ++i)
+		start_thread(threads + i);
+
+	start_thread_helper(threads);
+
+	for (i = 1; i < sizeof threads / sizeof *threads; ++i)
+		join_thread(threads + i);
+
+	return 0;
+}