diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 02ff850278b1..ef8114720c73 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -216,6 +216,9 @@ config USB_F_PRINTER
 config USB_F_TCM
 	tristate
 
+config USB_F_ACC
+	tristate
+
 # this first set of drivers all depend on bulk-capable hardware.
 
 config USB_CONFIGFS
@@ -369,6 +372,13 @@ config USB_CONFIGFS_F_FS
 	  implemented in kernel space (for instance Ethernet, serial or
 	  mass storage) and other are implemented in user space.
 
+config USB_CONFIGFS_F_ACC
+	bool "Accessory gadget"
+	depends on USB_CONFIGFS
+	select USB_F_ACC
+	help
+	  USB gadget Accessory support
+
 config USB_CONFIGFS_F_UAC1
 	bool "Audio Class 1.0"
 	depends on USB_CONFIGFS
diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile
index 5d3a6cf02218..2305360e5f22 100644
--- a/drivers/usb/gadget/function/Makefile
+++ b/drivers/usb/gadget/function/Makefile
@@ -50,3 +50,5 @@ usb_f_printer-y			:= f_printer.o
 obj-$(CONFIG_USB_F_PRINTER)	+= usb_f_printer.o
 usb_f_tcm-y			:= f_tcm.o
 obj-$(CONFIG_USB_F_TCM)		+= usb_f_tcm.o
+usb_f_accessory-y		:= f_accessory.o
+obj-$(CONFIG_USB_F_ACC)		+= usb_f_accessory.o
diff --git a/drivers/usb/gadget/function/f_accessory.c b/drivers/usb/gadget/function/f_accessory.c
new file mode 100644
index 000000000000..514eadee1793
--- /dev/null
+++ b/drivers/usb/gadget/function/f_accessory.c
@@ -0,0 +1,1352 @@
+/*
+ * Gadget Function Driver for Android USB accessories
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+/* #define DEBUG */
+/* #define VERBOSE_DEBUG */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+
+#include <linux/types.h>
+#include <linux/file.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+
+#include <linux/hid.h>
+#include <linux/hiddev.h>
+#include <linux/usb.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/f_accessory.h>
+
+#include <linux/configfs.h>
+#include <linux/usb/composite.h>
+
+#define MAX_INST_NAME_LEN        40
+#define BULK_BUFFER_SIZE    16384
+#define ACC_STRING_SIZE     256
+
+#define PROTOCOL_VERSION    2
+
+/* String IDs */
+#define INTERFACE_STRING_INDEX	0
+
+/* number of tx and rx requests to allocate */
+#define TX_REQ_MAX 4
+#define RX_REQ_MAX 2
+
+struct acc_hid_dev {
+	struct list_head	list;
+	struct hid_device *hid;
+	struct acc_dev *dev;
+	/* accessory defined ID */
+	int id;
+	/* HID report descriptor */
+	u8 *report_desc;
+	/* length of HID report descriptor */
+	int report_desc_len;
+	/* number of bytes of report_desc we have received so far */
+	int report_desc_offset;
+};
+
+struct acc_dev {
+	struct usb_function function;
+	struct usb_composite_dev *cdev;
+	spinlock_t lock;
+
+	struct usb_ep *ep_in;
+	struct usb_ep *ep_out;
+
+	/* online indicates state of function_set_alt & function_unbind
+	 * set to 1 when we connect
+	 */
+	int online:1;
+
+	/* disconnected indicates state of open & release
+	 * Set to 1 when we disconnect.
+	 * Not cleared until our file is closed.
+	 */
+	int disconnected:1;
+
+	/* strings sent by the host */
+	char manufacturer[ACC_STRING_SIZE];
+	char model[ACC_STRING_SIZE];
+	char description[ACC_STRING_SIZE];
+	char version[ACC_STRING_SIZE];
+	char uri[ACC_STRING_SIZE];
+	char serial[ACC_STRING_SIZE];
+
+	/* for acc_complete_set_string */
+	int string_index;
+
+	/* set to 1 if we have a pending start request */
+	int start_requested;
+
+	int audio_mode;
+
+	/* synchronize access to our device file */
+	atomic_t open_excl;
+
+	struct list_head tx_idle;
+
+	wait_queue_head_t read_wq;
+	wait_queue_head_t write_wq;
+	struct usb_request *rx_req[RX_REQ_MAX];
+	int rx_done;
+
+	/* delayed work for handling ACCESSORY_START */
+	struct delayed_work start_work;
+
+	/* worker for registering and unregistering hid devices */
+	struct work_struct hid_work;
+
+	/* list of active HID devices */
+	struct list_head	hid_list;
+
+	/* list of new HID devices to register */
+	struct list_head	new_hid_list;
+
+	/* list of dead HID devices to unregister */
+	struct list_head	dead_hid_list;
+};
+
+static struct usb_interface_descriptor acc_interface_desc = {
+	.bLength                = USB_DT_INTERFACE_SIZE,
+	.bDescriptorType        = USB_DT_INTERFACE,
+	.bInterfaceNumber       = 0,
+	.bNumEndpoints          = 2,
+	.bInterfaceClass        = USB_CLASS_VENDOR_SPEC,
+	.bInterfaceSubClass     = USB_SUBCLASS_VENDOR_SPEC,
+	.bInterfaceProtocol     = 0,
+};
+
+static struct usb_endpoint_descriptor acc_highspeed_in_desc = {
+	.bLength                = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType        = USB_DT_ENDPOINT,
+	.bEndpointAddress       = USB_DIR_IN,
+	.bmAttributes           = USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize         = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor acc_highspeed_out_desc = {
+	.bLength                = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType        = USB_DT_ENDPOINT,
+	.bEndpointAddress       = USB_DIR_OUT,
+	.bmAttributes           = USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize         = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor acc_fullspeed_in_desc = {
+	.bLength                = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType        = USB_DT_ENDPOINT,
+	.bEndpointAddress       = USB_DIR_IN,
+	.bmAttributes           = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor acc_fullspeed_out_desc = {
+	.bLength                = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType        = USB_DT_ENDPOINT,
+	.bEndpointAddress       = USB_DIR_OUT,
+	.bmAttributes           = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_acc_descs[] = {
+	(struct usb_descriptor_header *) &acc_interface_desc,
+	(struct usb_descriptor_header *) &acc_fullspeed_in_desc,
+	(struct usb_descriptor_header *) &acc_fullspeed_out_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *hs_acc_descs[] = {
+	(struct usb_descriptor_header *) &acc_interface_desc,
+	(struct usb_descriptor_header *) &acc_highspeed_in_desc,
+	(struct usb_descriptor_header *) &acc_highspeed_out_desc,
+	NULL,
+};
+
+static struct usb_string acc_string_defs[] = {
+	[INTERFACE_STRING_INDEX].s	= "Android Accessory Interface",
+	{  },	/* end of list */
+};
+
+static struct usb_gadget_strings acc_string_table = {
+	.language		= 0x0409,	/* en-US */
+	.strings		= acc_string_defs,
+};
+
+static struct usb_gadget_strings *acc_strings[] = {
+	&acc_string_table,
+	NULL,
+};
+
+/* temporary variable used between acc_open() and acc_gadget_bind() */
+static struct acc_dev *_acc_dev;
+
+struct acc_instance {
+	struct usb_function_instance func_inst;
+	const char *name;
+};
+
+static inline struct acc_dev *func_to_dev(struct usb_function *f)
+{
+	return container_of(f, struct acc_dev, function);
+}
+
+static struct usb_request *acc_request_new(struct usb_ep *ep, int buffer_size)
+{
+	struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
+
+	if (!req)
+		return NULL;
+
+	/* now allocate buffers for the requests */
+	req->buf = kmalloc(buffer_size, GFP_KERNEL);
+	if (!req->buf) {
+		usb_ep_free_request(ep, req);
+		return NULL;
+	}
+
+	return req;
+}
+
+static void acc_request_free(struct usb_request *req, struct usb_ep *ep)
+{
+	if (req) {
+		kfree(req->buf);
+		usb_ep_free_request(ep, req);
+	}
+}
+
+/* add a request to the tail of a list */
+static void req_put(struct acc_dev *dev, struct list_head *head,
+		struct usb_request *req)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	list_add_tail(&req->list, head);
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/* remove a request from the head of a list */
+static struct usb_request *req_get(struct acc_dev *dev, struct list_head *head)
+{
+	unsigned long flags;
+	struct usb_request *req;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	if (list_empty(head)) {
+		req = 0;
+	} else {
+		req = list_first_entry(head, struct usb_request, list);
+		list_del(&req->list);
+	}
+	spin_unlock_irqrestore(&dev->lock, flags);
+	return req;
+}
+
+static void acc_set_disconnected(struct acc_dev *dev)
+{
+	dev->disconnected = 1;
+}
+
+static void acc_complete_in(struct usb_ep *ep, struct usb_request *req)
+{
+	struct acc_dev *dev = _acc_dev;
+
+	if (req->status == -ESHUTDOWN) {
+		pr_debug("acc_complete_in set disconnected");
+		acc_set_disconnected(dev);
+	}
+
+	req_put(dev, &dev->tx_idle, req);
+
+	wake_up(&dev->write_wq);
+}
+
+static void acc_complete_out(struct usb_ep *ep, struct usb_request *req)
+{
+	struct acc_dev *dev = _acc_dev;
+
+	dev->rx_done = 1;
+	if (req->status == -ESHUTDOWN) {
+		pr_debug("acc_complete_out set disconnected");
+		acc_set_disconnected(dev);
+	}
+
+	wake_up(&dev->read_wq);
+}
+
+static void acc_complete_set_string(struct usb_ep *ep, struct usb_request *req)
+{
+	struct acc_dev	*dev = ep->driver_data;
+	char *string_dest = NULL;
+	int length = req->actual;
+
+	if (req->status != 0) {
+		pr_err("acc_complete_set_string, err %d\n", req->status);
+		return;
+	}
+
+	switch (dev->string_index) {
+	case ACCESSORY_STRING_MANUFACTURER:
+		string_dest = dev->manufacturer;
+		break;
+	case ACCESSORY_STRING_MODEL:
+		string_dest = dev->model;
+		break;
+	case ACCESSORY_STRING_DESCRIPTION:
+		string_dest = dev->description;
+		break;
+	case ACCESSORY_STRING_VERSION:
+		string_dest = dev->version;
+		break;
+	case ACCESSORY_STRING_URI:
+		string_dest = dev->uri;
+		break;
+	case ACCESSORY_STRING_SERIAL:
+		string_dest = dev->serial;
+		break;
+	}
+	if (string_dest) {
+		unsigned long flags;
+
+		if (length >= ACC_STRING_SIZE)
+			length = ACC_STRING_SIZE - 1;
+
+		spin_lock_irqsave(&dev->lock, flags);
+		memcpy(string_dest, req->buf, length);
+		/* ensure zero termination */
+		string_dest[length] = 0;
+		spin_unlock_irqrestore(&dev->lock, flags);
+	} else {
+		pr_err("unknown accessory string index %d\n",
+			dev->string_index);
+	}
+}
+
+static void acc_complete_set_hid_report_desc(struct usb_ep *ep,
+		struct usb_request *req)
+{
+	struct acc_hid_dev *hid = req->context;
+	struct acc_dev *dev = hid->dev;
+	int length = req->actual;
+
+	if (req->status != 0) {
+		pr_err("acc_complete_set_hid_report_desc, err %d\n",
+			req->status);
+		return;
+	}
+
+	memcpy(hid->report_desc + hid->report_desc_offset, req->buf, length);
+	hid->report_desc_offset += length;
+	if (hid->report_desc_offset == hid->report_desc_len) {
+		/* After we have received the entire report descriptor
+		 * we schedule work to initialize the HID device
+		 */
+		schedule_work(&dev->hid_work);
+	}
+}
+
+static void acc_complete_send_hid_event(struct usb_ep *ep,
+		struct usb_request *req)
+{
+	struct acc_hid_dev *hid = req->context;
+	int length = req->actual;
+
+	if (req->status != 0) {
+		pr_err("acc_complete_send_hid_event, err %d\n", req->status);
+		return;
+	}
+
+	hid_report_raw_event(hid->hid, HID_INPUT_REPORT, req->buf, length, 1);
+}
+
+static int acc_hid_parse(struct hid_device *hid)
+{
+	struct acc_hid_dev *hdev = hid->driver_data;
+
+	hid_parse_report(hid, hdev->report_desc, hdev->report_desc_len);
+	return 0;
+}
+
+static int acc_hid_start(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void acc_hid_stop(struct hid_device *hid)
+{
+}
+
+static int acc_hid_open(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void acc_hid_close(struct hid_device *hid)
+{
+}
+
+static int acc_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
+	__u8 *buf, size_t len, unsigned char rtype, int reqtype)
+{
+	return 0;
+}
+
+static struct hid_ll_driver acc_hid_ll_driver = {
+	.parse = acc_hid_parse,
+	.start = acc_hid_start,
+	.stop = acc_hid_stop,
+	.open = acc_hid_open,
+	.close = acc_hid_close,
+	.raw_request = acc_hid_raw_request,
+};
+
+static struct acc_hid_dev *acc_hid_new(struct acc_dev *dev,
+		int id, int desc_len)
+{
+	struct acc_hid_dev *hdev;
+
+	hdev = kzalloc(sizeof(*hdev), GFP_ATOMIC);
+	if (!hdev)
+		return NULL;
+	hdev->report_desc = kzalloc(desc_len, GFP_ATOMIC);
+	if (!hdev->report_desc) {
+		kfree(hdev);
+		return NULL;
+	}
+	hdev->dev = dev;
+	hdev->id = id;
+	hdev->report_desc_len = desc_len;
+
+	return hdev;
+}
+
+static struct acc_hid_dev *acc_hid_get(struct list_head *list, int id)
+{
+	struct acc_hid_dev *hid;
+
+	list_for_each_entry(hid, list, list) {
+		if (hid->id == id)
+			return hid;
+	}
+	return NULL;
+}
+
+static int acc_register_hid(struct acc_dev *dev, int id, int desc_length)
+{
+	struct acc_hid_dev *hid;
+	unsigned long flags;
+
+	/* report descriptor length must be > 0 */
+	if (desc_length <= 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	/* replace HID if one already exists with this ID */
+	hid = acc_hid_get(&dev->hid_list, id);
+	if (!hid)
+		hid = acc_hid_get(&dev->new_hid_list, id);
+	if (hid)
+		list_move(&hid->list, &dev->dead_hid_list);
+
+	hid = acc_hid_new(dev, id, desc_length);
+	if (!hid) {
+		spin_unlock_irqrestore(&dev->lock, flags);
+		return -ENOMEM;
+	}
+
+	list_add(&hid->list, &dev->new_hid_list);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	/* schedule work to register the HID device */
+	schedule_work(&dev->hid_work);
+	return 0;
+}
+
+static int acc_unregister_hid(struct acc_dev *dev, int id)
+{
+	struct acc_hid_dev *hid;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	hid = acc_hid_get(&dev->hid_list, id);
+	if (!hid)
+		hid = acc_hid_get(&dev->new_hid_list, id);
+	if (!hid) {
+		spin_unlock_irqrestore(&dev->lock, flags);
+		return -EINVAL;
+	}
+
+	list_move(&hid->list, &dev->dead_hid_list);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	schedule_work(&dev->hid_work);
+	return 0;
+}
+
+static int create_bulk_endpoints(struct acc_dev *dev,
+				struct usb_endpoint_descriptor *in_desc,
+				struct usb_endpoint_descriptor *out_desc)
+{
+	struct usb_composite_dev *cdev = dev->cdev;
+	struct usb_request *req;
+	struct usb_ep *ep;
+	int i;
+
+	DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
+
+	ep = usb_ep_autoconfig(cdev->gadget, in_desc);
+	if (!ep) {
+		DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
+		return -ENODEV;
+	}
+	DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
+	ep->driver_data = dev;		/* claim the endpoint */
+	dev->ep_in = ep;
+
+	ep = usb_ep_autoconfig(cdev->gadget, out_desc);
+	if (!ep) {
+		DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
+		return -ENODEV;
+	}
+	DBG(cdev, "usb_ep_autoconfig for ep_out got %s\n", ep->name);
+	ep->driver_data = dev;		/* claim the endpoint */
+	dev->ep_out = ep;
+
+	/* now allocate requests for our endpoints */
+	for (i = 0; i < TX_REQ_MAX; i++) {
+		req = acc_request_new(dev->ep_in, BULK_BUFFER_SIZE);
+		if (!req)
+			goto fail;
+		req->complete = acc_complete_in;
+		req_put(dev, &dev->tx_idle, req);
+	}
+	for (i = 0; i < RX_REQ_MAX; i++) {
+		req = acc_request_new(dev->ep_out, BULK_BUFFER_SIZE);
+		if (!req)
+			goto fail;
+		req->complete = acc_complete_out;
+		dev->rx_req[i] = req;
+	}
+
+	return 0;
+
+fail:
+	pr_err("acc_bind() could not allocate requests\n");
+	while ((req = req_get(dev, &dev->tx_idle)))
+		acc_request_free(req, dev->ep_in);
+	for (i = 0; i < RX_REQ_MAX; i++)
+		acc_request_free(dev->rx_req[i], dev->ep_out);
+	return -1;
+}
+
+static ssize_t acc_read(struct file *fp, char __user *buf,
+	size_t count, loff_t *pos)
+{
+	struct acc_dev *dev = fp->private_data;
+	struct usb_request *req;
+	ssize_t r = count;
+	unsigned xfer;
+	int ret = 0;
+
+	pr_debug("acc_read(%zu)\n", count);
+
+	if (dev->disconnected) {
+		pr_debug("acc_read disconnected");
+		return -ENODEV;
+	}
+
+	if (count > BULK_BUFFER_SIZE)
+		count = BULK_BUFFER_SIZE;
+
+	/* we will block until we're online */
+	pr_debug("acc_read: waiting for online\n");
+	ret = wait_event_interruptible(dev->read_wq, dev->online);
+	if (ret < 0) {
+		r = ret;
+		goto done;
+	}
+
+	if (dev->rx_done) {
+		// last req cancelled. try to get it.
+		req = dev->rx_req[0];
+		goto copy_data;
+	}
+
+requeue_req:
+	/* queue a request */
+	req = dev->rx_req[0];
+	req->length = count;
+	dev->rx_done = 0;
+	ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
+	if (ret < 0) {
+		r = -EIO;
+		goto done;
+	} else {
+		pr_debug("rx %p queue\n", req);
+	}
+
+	/* wait for a request to complete */
+	ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
+	if (ret < 0) {
+		r = ret;
+		ret = usb_ep_dequeue(dev->ep_out, req);
+		if (ret != 0) {
+			// cancel failed. There can be a data already received.
+			// it will be retrieved in the next read.
+			pr_debug("acc_read: cancelling failed %d", ret);
+		}
+		goto done;
+	}
+
+copy_data:
+	dev->rx_done = 0;
+	if (dev->online) {
+		/* If we got a 0-len packet, throw it back and try again. */
+		if (req->actual == 0)
+			goto requeue_req;
+
+		pr_debug("rx %p %u\n", req, req->actual);
+		xfer = (req->actual < count) ? req->actual : count;
+		r = xfer;
+		if (copy_to_user(buf, req->buf, xfer))
+			r = -EFAULT;
+	} else
+		r = -EIO;
+
+done:
+	pr_debug("acc_read returning %zd\n", r);
+	return r;
+}
+
+static ssize_t acc_write(struct file *fp, const char __user *buf,
+	size_t count, loff_t *pos)
+{
+	struct acc_dev *dev = fp->private_data;
+	struct usb_request *req = 0;
+	ssize_t r = count;
+	unsigned xfer;
+	int ret;
+
+	pr_debug("acc_write(%zu)\n", count);
+
+	if (!dev->online || dev->disconnected) {
+		pr_debug("acc_write disconnected or not online");
+		return -ENODEV;
+	}
+
+	while (count > 0) {
+		if (!dev->online) {
+			pr_debug("acc_write dev->error\n");
+			r = -EIO;
+			break;
+		}
+
+		/* get an idle tx request to use */
+		req = 0;
+		ret = wait_event_interruptible(dev->write_wq,
+			((req = req_get(dev, &dev->tx_idle)) || !dev->online));
+		if (!req) {
+			r = ret;
+			break;
+		}
+
+		if (count > BULK_BUFFER_SIZE) {
+			xfer = BULK_BUFFER_SIZE;
+			/* ZLP, They will be more TX requests so not yet. */
+			req->zero = 0;
+		} else {
+			xfer = count;
+			/* If the data length is a multple of the
+			 * maxpacket size then send a zero length packet(ZLP).
+			*/
+			req->zero = ((xfer % dev->ep_in->maxpacket) == 0);
+		}
+		if (copy_from_user(req->buf, buf, xfer)) {
+			r = -EFAULT;
+			break;
+		}
+
+		req->length = xfer;
+		ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
+		if (ret < 0) {
+			pr_debug("acc_write: xfer error %d\n", ret);
+			r = -EIO;
+			break;
+		}
+
+		buf += xfer;
+		count -= xfer;
+
+		/* zero this so we don't try to free it on error exit */
+		req = 0;
+	}
+
+	if (req)
+		req_put(dev, &dev->tx_idle, req);
+
+	pr_debug("acc_write returning %zd\n", r);
+	return r;
+}
+
+static long acc_ioctl(struct file *fp, unsigned code, unsigned long value)
+{
+	struct acc_dev *dev = fp->private_data;
+	char *src = NULL;
+	int ret;
+
+	switch (code) {
+	case ACCESSORY_GET_STRING_MANUFACTURER:
+		src = dev->manufacturer;
+		break;
+	case ACCESSORY_GET_STRING_MODEL:
+		src = dev->model;
+		break;
+	case ACCESSORY_GET_STRING_DESCRIPTION:
+		src = dev->description;
+		break;
+	case ACCESSORY_GET_STRING_VERSION:
+		src = dev->version;
+		break;
+	case ACCESSORY_GET_STRING_URI:
+		src = dev->uri;
+		break;
+	case ACCESSORY_GET_STRING_SERIAL:
+		src = dev->serial;
+		break;
+	case ACCESSORY_IS_START_REQUESTED:
+		return dev->start_requested;
+	case ACCESSORY_GET_AUDIO_MODE:
+		return dev->audio_mode;
+	}
+	if (!src)
+		return -EINVAL;
+
+	ret = strlen(src) + 1;
+	if (copy_to_user((void __user *)value, src, ret))
+		ret = -EFAULT;
+	return ret;
+}
+
+static int acc_open(struct inode *ip, struct file *fp)
+{
+	printk(KERN_INFO "acc_open\n");
+	if (atomic_xchg(&_acc_dev->open_excl, 1))
+		return -EBUSY;
+
+	_acc_dev->disconnected = 0;
+	fp->private_data = _acc_dev;
+	return 0;
+}
+
+static int acc_release(struct inode *ip, struct file *fp)
+{
+	printk(KERN_INFO "acc_release\n");
+
+	WARN_ON(!atomic_xchg(&_acc_dev->open_excl, 0));
+	/* indicate that we are disconnected
+	 * still could be online so don't touch online flag
+	 */
+	_acc_dev->disconnected = 1;
+	return 0;
+}
+
+/* file operations for /dev/usb_accessory */
+static const struct file_operations acc_fops = {
+	.owner = THIS_MODULE,
+	.read = acc_read,
+	.write = acc_write,
+	.unlocked_ioctl = acc_ioctl,
+	.open = acc_open,
+	.release = acc_release,
+};
+
+static int acc_hid_probe(struct hid_device *hdev,
+		const struct hid_device_id *id)
+{
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+}
+
+static struct miscdevice acc_device = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "usb_accessory",
+	.fops = &acc_fops,
+};
+
+static const struct hid_device_id acc_hid_table[] = {
+	{ HID_USB_DEVICE(HID_ANY_ID, HID_ANY_ID) },
+	{ }
+};
+
+static struct hid_driver acc_hid_driver = {
+	.name = "USB accessory",
+	.id_table = acc_hid_table,
+	.probe = acc_hid_probe,
+};
+
+static void acc_complete_setup_noop(struct usb_ep *ep, struct usb_request *req)
+{
+	/*
+	 * Default no-op function when nothing needs to be done for the
+	 * setup request
+	 */
+}
+
+int acc_ctrlrequest(struct usb_composite_dev *cdev,
+				const struct usb_ctrlrequest *ctrl)
+{
+	struct acc_dev	*dev = _acc_dev;
+	int	value = -EOPNOTSUPP;
+	struct acc_hid_dev *hid;
+	int offset;
+	u8 b_requestType = ctrl->bRequestType;
+	u8 b_request = ctrl->bRequest;
+	u16	w_index = le16_to_cpu(ctrl->wIndex);
+	u16	w_value = le16_to_cpu(ctrl->wValue);
+	u16	w_length = le16_to_cpu(ctrl->wLength);
+	unsigned long flags;
+
+/*
+	printk(KERN_INFO "acc_ctrlrequest "
+			"%02x.%02x v%04x i%04x l%u\n",
+			b_requestType, b_request,
+			w_value, w_index, w_length);
+*/
+
+	if (b_requestType == (USB_DIR_OUT | USB_TYPE_VENDOR)) {
+		if (b_request == ACCESSORY_START) {
+			dev->start_requested = 1;
+			schedule_delayed_work(
+				&dev->start_work, msecs_to_jiffies(10));
+			value = 0;
+			cdev->req->complete = acc_complete_setup_noop;
+		} else if (b_request == ACCESSORY_SEND_STRING) {
+			dev->string_index = w_index;
+			cdev->gadget->ep0->driver_data = dev;
+			cdev->req->complete = acc_complete_set_string;
+			value = w_length;
+		} else if (b_request == ACCESSORY_SET_AUDIO_MODE &&
+				w_index == 0 && w_length == 0) {
+			dev->audio_mode = w_value;
+			cdev->req->complete = acc_complete_setup_noop;
+			value = 0;
+		} else if (b_request == ACCESSORY_REGISTER_HID) {
+			cdev->req->complete = acc_complete_setup_noop;
+			value = acc_register_hid(dev, w_value, w_index);
+		} else if (b_request == ACCESSORY_UNREGISTER_HID) {
+			cdev->req->complete = acc_complete_setup_noop;
+			value = acc_unregister_hid(dev, w_value);
+		} else if (b_request == ACCESSORY_SET_HID_REPORT_DESC) {
+			spin_lock_irqsave(&dev->lock, flags);
+			hid = acc_hid_get(&dev->new_hid_list, w_value);
+			spin_unlock_irqrestore(&dev->lock, flags);
+			if (!hid) {
+				value = -EINVAL;
+				goto err;
+			}
+			offset = w_index;
+			if (offset != hid->report_desc_offset
+				|| offset + w_length > hid->report_desc_len) {
+				value = -EINVAL;
+				goto err;
+			}
+			cdev->req->context = hid;
+			cdev->req->complete = acc_complete_set_hid_report_desc;
+			value = w_length;
+		} else if (b_request == ACCESSORY_SEND_HID_EVENT) {
+			spin_lock_irqsave(&dev->lock, flags);
+			hid = acc_hid_get(&dev->hid_list, w_value);
+			spin_unlock_irqrestore(&dev->lock, flags);
+			if (!hid) {
+				value = -EINVAL;
+				goto err;
+			}
+			cdev->req->context = hid;
+			cdev->req->complete = acc_complete_send_hid_event;
+			value = w_length;
+		}
+	} else if (b_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) {
+		if (b_request == ACCESSORY_GET_PROTOCOL) {
+			*((u16 *)cdev->req->buf) = PROTOCOL_VERSION;
+			value = sizeof(u16);
+			cdev->req->complete = acc_complete_setup_noop;
+			/* clear any string left over from a previous session */
+			memset(dev->manufacturer, 0, sizeof(dev->manufacturer));
+			memset(dev->model, 0, sizeof(dev->model));
+			memset(dev->description, 0, sizeof(dev->description));
+			memset(dev->version, 0, sizeof(dev->version));
+			memset(dev->uri, 0, sizeof(dev->uri));
+			memset(dev->serial, 0, sizeof(dev->serial));
+			dev->start_requested = 0;
+			dev->audio_mode = 0;
+		}
+	}
+
+	if (value >= 0) {
+		cdev->req->zero = 0;
+		cdev->req->length = value;
+		value = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
+		if (value < 0)
+			ERROR(cdev, "%s setup response queue error\n",
+				__func__);
+	}
+
+err:
+	if (value == -EOPNOTSUPP)
+		VDBG(cdev,
+			"unknown class-specific control req "
+			"%02x.%02x v%04x i%04x l%u\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+	return value;
+}
+EXPORT_SYMBOL_GPL(acc_ctrlrequest);
+
+static int
+__acc_function_bind(struct usb_configuration *c,
+			struct usb_function *f, bool configfs)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct acc_dev	*dev = func_to_dev(f);
+	int			id;
+	int			ret;
+
+	DBG(cdev, "acc_function_bind dev: %p\n", dev);
+
+	if (configfs) {
+		if (acc_string_defs[INTERFACE_STRING_INDEX].id == 0) {
+			ret = usb_string_id(c->cdev);
+			if (ret < 0)
+				return ret;
+			acc_string_defs[INTERFACE_STRING_INDEX].id = ret;
+			acc_interface_desc.iInterface = ret;
+		}
+		dev->cdev = c->cdev;
+	}
+	ret = hid_register_driver(&acc_hid_driver);
+	if (ret)
+		return ret;
+
+	dev->start_requested = 0;
+
+	/* allocate interface ID(s) */
+	id = usb_interface_id(c, f);
+	if (id < 0)
+		return id;
+	acc_interface_desc.bInterfaceNumber = id;
+
+	/* allocate endpoints */
+	ret = create_bulk_endpoints(dev, &acc_fullspeed_in_desc,
+			&acc_fullspeed_out_desc);
+	if (ret)
+		return ret;
+
+	/* support high speed hardware */
+	if (gadget_is_dualspeed(c->cdev->gadget)) {
+		acc_highspeed_in_desc.bEndpointAddress =
+			acc_fullspeed_in_desc.bEndpointAddress;
+		acc_highspeed_out_desc.bEndpointAddress =
+			acc_fullspeed_out_desc.bEndpointAddress;
+	}
+
+	DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			f->name, dev->ep_in->name, dev->ep_out->name);
+	return 0;
+}
+
+static int
+acc_function_bind_configfs(struct usb_configuration *c, struct usb_function *f)
+{
+	return __acc_function_bind(c, f, true);
+}
+
+static void
+kill_all_hid_devices(struct acc_dev *dev)
+{
+	struct acc_hid_dev *hid;
+	struct list_head *entry, *temp;
+	unsigned long flags;
+
+	/* do nothing if usb accessory device doesn't exist */
+	if (!dev)
+		return;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	list_for_each_safe(entry, temp, &dev->hid_list) {
+		hid = list_entry(entry, struct acc_hid_dev, list);
+		list_del(&hid->list);
+		list_add(&hid->list, &dev->dead_hid_list);
+	}
+	list_for_each_safe(entry, temp, &dev->new_hid_list) {
+		hid = list_entry(entry, struct acc_hid_dev, list);
+		list_del(&hid->list);
+		list_add(&hid->list, &dev->dead_hid_list);
+	}
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	schedule_work(&dev->hid_work);
+}
+
+static void
+acc_hid_unbind(struct acc_dev *dev)
+{
+	hid_unregister_driver(&acc_hid_driver);
+	kill_all_hid_devices(dev);
+}
+
+static void
+acc_function_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct acc_dev	*dev = func_to_dev(f);
+	struct usb_request *req;
+	int i;
+
+	dev->online = 0;		/* clear online flag */
+	wake_up(&dev->read_wq);		/* unblock reads on closure */
+	wake_up(&dev->write_wq);	/* likewise for writes */
+
+	while ((req = req_get(dev, &dev->tx_idle)))
+		acc_request_free(req, dev->ep_in);
+	for (i = 0; i < RX_REQ_MAX; i++)
+		acc_request_free(dev->rx_req[i], dev->ep_out);
+
+	acc_hid_unbind(dev);
+}
+
+static void acc_start_work(struct work_struct *data)
+{
+	char *envp[2] = { "ACCESSORY=START", NULL };
+
+	kobject_uevent_env(&acc_device.this_device->kobj, KOBJ_CHANGE, envp);
+}
+
+static int acc_hid_init(struct acc_hid_dev *hdev)
+{
+	struct hid_device *hid;
+	int ret;
+
+	hid = hid_allocate_device();
+	if (IS_ERR(hid))
+		return PTR_ERR(hid);
+
+	hid->ll_driver = &acc_hid_ll_driver;
+	hid->dev.parent = acc_device.this_device;
+
+	hid->bus = BUS_USB;
+	hid->vendor = HID_ANY_ID;
+	hid->product = HID_ANY_ID;
+	hid->driver_data = hdev;
+	ret = hid_add_device(hid);
+	if (ret) {
+		pr_err("can't add hid device: %d\n", ret);
+		hid_destroy_device(hid);
+		return ret;
+	}
+
+	hdev->hid = hid;
+	return 0;
+}
+
+static void acc_hid_delete(struct acc_hid_dev *hid)
+{
+	kfree(hid->report_desc);
+	kfree(hid);
+}
+
+static void acc_hid_work(struct work_struct *data)
+{
+	struct acc_dev *dev = _acc_dev;
+	struct list_head	*entry, *temp;
+	struct acc_hid_dev *hid;
+	struct list_head	new_list, dead_list;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&new_list);
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* copy hids that are ready for initialization to new_list */
+	list_for_each_safe(entry, temp, &dev->new_hid_list) {
+		hid = list_entry(entry, struct acc_hid_dev, list);
+		if (hid->report_desc_offset == hid->report_desc_len)
+			list_move(&hid->list, &new_list);
+	}
+
+	if (list_empty(&dev->dead_hid_list)) {
+		INIT_LIST_HEAD(&dead_list);
+	} else {
+		/* move all of dev->dead_hid_list to dead_list */
+		dead_list.prev = dev->dead_hid_list.prev;
+		dead_list.next = dev->dead_hid_list.next;
+		dead_list.next->prev = &dead_list;
+		dead_list.prev->next = &dead_list;
+		INIT_LIST_HEAD(&dev->dead_hid_list);
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	/* register new HID devices */
+	list_for_each_safe(entry, temp, &new_list) {
+		hid = list_entry(entry, struct acc_hid_dev, list);
+		if (acc_hid_init(hid)) {
+			pr_err("can't add HID device %p\n", hid);
+			acc_hid_delete(hid);
+		} else {
+			spin_lock_irqsave(&dev->lock, flags);
+			list_move(&hid->list, &dev->hid_list);
+			spin_unlock_irqrestore(&dev->lock, flags);
+		}
+	}
+
+	/* remove dead HID devices */
+	list_for_each_safe(entry, temp, &dead_list) {
+		hid = list_entry(entry, struct acc_hid_dev, list);
+		list_del(&hid->list);
+		if (hid->hid)
+			hid_destroy_device(hid->hid);
+		acc_hid_delete(hid);
+	}
+}
+
+static int acc_function_set_alt(struct usb_function *f,
+		unsigned intf, unsigned alt)
+{
+	struct acc_dev	*dev = func_to_dev(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	int ret;
+
+	DBG(cdev, "acc_function_set_alt intf: %d alt: %d\n", intf, alt);
+
+	ret = config_ep_by_speed(cdev->gadget, f, dev->ep_in);
+	if (ret)
+		return ret;
+
+	ret = usb_ep_enable(dev->ep_in);
+	if (ret)
+		return ret;
+
+	ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
+	if (ret)
+		return ret;
+
+	ret = usb_ep_enable(dev->ep_out);
+	if (ret) {
+		usb_ep_disable(dev->ep_in);
+		return ret;
+	}
+
+	dev->online = 1;
+	dev->disconnected = 0; /* if online then not disconnected */
+
+	/* readers may be blocked waiting for us to go online */
+	wake_up(&dev->read_wq);
+	return 0;
+}
+
+static void acc_function_disable(struct usb_function *f)
+{
+	struct acc_dev	*dev = func_to_dev(f);
+	struct usb_composite_dev	*cdev = dev->cdev;
+
+	DBG(cdev, "acc_function_disable\n");
+	acc_set_disconnected(dev); /* this now only sets disconnected */
+	dev->online = 0; /* so now need to clear online flag here too */
+	usb_ep_disable(dev->ep_in);
+	usb_ep_disable(dev->ep_out);
+
+	/* readers may be blocked waiting for us to go online */
+	wake_up(&dev->read_wq);
+
+	VDBG(cdev, "%s disabled\n", dev->function.name);
+}
+
+static int acc_setup(void)
+{
+	struct acc_dev *dev;
+	int ret;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	spin_lock_init(&dev->lock);
+	init_waitqueue_head(&dev->read_wq);
+	init_waitqueue_head(&dev->write_wq);
+	atomic_set(&dev->open_excl, 0);
+	INIT_LIST_HEAD(&dev->tx_idle);
+	INIT_LIST_HEAD(&dev->hid_list);
+	INIT_LIST_HEAD(&dev->new_hid_list);
+	INIT_LIST_HEAD(&dev->dead_hid_list);
+	INIT_DELAYED_WORK(&dev->start_work, acc_start_work);
+	INIT_WORK(&dev->hid_work, acc_hid_work);
+
+	/* _acc_dev must be set before calling usb_gadget_register_driver */
+	_acc_dev = dev;
+
+	ret = misc_register(&acc_device);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	kfree(dev);
+	pr_err("USB accessory gadget driver failed to initialize\n");
+	return ret;
+}
+
+void acc_disconnect(void)
+{
+	/* unregister all HID devices if USB is disconnected */
+	kill_all_hid_devices(_acc_dev);
+}
+EXPORT_SYMBOL_GPL(acc_disconnect);
+
+static void acc_cleanup(void)
+{
+	misc_deregister(&acc_device);
+	kfree(_acc_dev);
+	_acc_dev = NULL;
+}
+static struct acc_instance *to_acc_instance(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct acc_instance,
+		func_inst.group);
+}
+
+static void acc_attr_release(struct config_item *item)
+{
+	struct acc_instance *fi_acc = to_acc_instance(item);
+
+	usb_put_function_instance(&fi_acc->func_inst);
+}
+
+static struct configfs_item_operations acc_item_ops = {
+	.release        = acc_attr_release,
+};
+
+static struct config_item_type acc_func_type = {
+	.ct_item_ops    = &acc_item_ops,
+	.ct_owner       = THIS_MODULE,
+};
+
+static struct acc_instance *to_fi_acc(struct usb_function_instance *fi)
+{
+	return container_of(fi, struct acc_instance, func_inst);
+}
+
+static int acc_set_inst_name(struct usb_function_instance *fi, const char *name)
+{
+	struct acc_instance *fi_acc;
+	char *ptr;
+	int name_len;
+
+	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;
+
+	fi_acc = to_fi_acc(fi);
+	fi_acc->name = ptr;
+	return 0;
+}
+
+static void acc_free_inst(struct usb_function_instance *fi)
+{
+	struct acc_instance *fi_acc;
+
+	fi_acc = to_fi_acc(fi);
+	kfree(fi_acc->name);
+	acc_cleanup();
+}
+
+static struct usb_function_instance *acc_alloc_inst(void)
+{
+	struct acc_instance *fi_acc;
+	struct acc_dev *dev;
+	int err;
+
+	fi_acc = kzalloc(sizeof(*fi_acc), GFP_KERNEL);
+	if (!fi_acc)
+		return ERR_PTR(-ENOMEM);
+	fi_acc->func_inst.set_inst_name = acc_set_inst_name;
+	fi_acc->func_inst.free_func_inst = acc_free_inst;
+
+	err = acc_setup();
+	if (err) {
+		kfree(fi_acc);
+		pr_err("Error setting ACCESSORY\n");
+		return ERR_PTR(err);
+	}
+
+	config_group_init_type_name(&fi_acc->func_inst.group,
+					"", &acc_func_type);
+	dev = _acc_dev;
+	return  &fi_acc->func_inst;
+}
+
+static void acc_free(struct usb_function *f)
+{
+/*NO-OP: no function specific resource allocation in mtp_alloc*/
+}
+
+int acc_ctrlrequest_configfs(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+	if (f->config != NULL && f->config->cdev != NULL)
+		return acc_ctrlrequest(f->config->cdev, ctrl);
+	else
+		return -1;
+}
+
+static struct usb_function *acc_alloc(struct usb_function_instance *fi)
+{
+	struct acc_dev *dev = _acc_dev;
+
+	pr_info("acc_alloc\n");
+
+	dev->function.name = "accessory";
+	dev->function.strings = acc_strings,
+	dev->function.fs_descriptors = fs_acc_descs;
+	dev->function.hs_descriptors = hs_acc_descs;
+	dev->function.bind = acc_function_bind_configfs;
+	dev->function.unbind = acc_function_unbind;
+	dev->function.set_alt = acc_function_set_alt;
+	dev->function.disable = acc_function_disable;
+	dev->function.free_func = acc_free;
+	dev->function.setup = acc_ctrlrequest_configfs;
+
+	return &dev->function;
+}
+DECLARE_USB_FUNCTION_INIT(accessory, acc_alloc_inst, acc_alloc);
+MODULE_LICENSE("GPL");
diff --git a/include/linux/usb/f_accessory.h b/include/linux/usb/f_accessory.h
new file mode 100644
index 000000000000..ebe3c4d59309
--- /dev/null
+++ b/include/linux/usb/f_accessory.h
@@ -0,0 +1,23 @@
+/*
+ * Gadget Function Driver for Android USB accessories
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __LINUX_USB_F_ACCESSORY_H
+#define __LINUX_USB_F_ACCESSORY_H
+
+#include <uapi/linux/usb/f_accessory.h>
+
+#endif /* __LINUX_USB_F_ACCESSORY_H */
diff --git a/include/uapi/linux/usb/f_accessory.h b/include/uapi/linux/usb/f_accessory.h
new file mode 100644
index 000000000000..0baeb7d0d74c
--- /dev/null
+++ b/include/uapi/linux/usb/f_accessory.h
@@ -0,0 +1,146 @@
+/*
+ * Gadget Function Driver for Android USB accessories
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef _UAPI_LINUX_USB_F_ACCESSORY_H
+#define _UAPI_LINUX_USB_F_ACCESSORY_H
+
+/* Use Google Vendor ID when in accessory mode */
+#define USB_ACCESSORY_VENDOR_ID 0x18D1
+
+
+/* Product ID to use when in accessory mode */
+#define USB_ACCESSORY_PRODUCT_ID 0x2D00
+
+/* Product ID to use when in accessory mode and adb is enabled */
+#define USB_ACCESSORY_ADB_PRODUCT_ID 0x2D01
+
+/* Indexes for strings sent by the host via ACCESSORY_SEND_STRING */
+#define ACCESSORY_STRING_MANUFACTURER   0
+#define ACCESSORY_STRING_MODEL          1
+#define ACCESSORY_STRING_DESCRIPTION    2
+#define ACCESSORY_STRING_VERSION        3
+#define ACCESSORY_STRING_URI            4
+#define ACCESSORY_STRING_SERIAL         5
+
+/* Control request for retrieving device's protocol version
+ *
+ *	requestType:    USB_DIR_IN | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_GET_PROTOCOL
+ *	value:          0
+ *	index:          0
+ *	data            version number (16 bits little endian)
+ *                     1 for original accessory support
+ *                     2 adds HID and device to host audio support
+ */
+#define ACCESSORY_GET_PROTOCOL  51
+
+/* Control request for host to send a string to the device
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_SEND_STRING
+ *	value:          0
+ *	index:          string ID
+ *	data            zero terminated UTF8 string
+ *
+ *  The device can later retrieve these strings via the
+ *  ACCESSORY_GET_STRING_* ioctls
+ */
+#define ACCESSORY_SEND_STRING   52
+
+/* Control request for starting device in accessory mode.
+ * The host sends this after setting all its strings to the device.
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_START
+ *	value:          0
+ *	index:          0
+ *	data            none
+ */
+#define ACCESSORY_START         53
+
+/* Control request for registering a HID device.
+ * Upon registering, a unique ID is sent by the accessory in the
+ * value parameter. This ID will be used for future commands for
+ * the device
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_REGISTER_HID_DEVICE
+ *	value:          Accessory assigned ID for the HID device
+ *	index:          total length of the HID report descriptor
+ *	data            none
+ */
+#define ACCESSORY_REGISTER_HID         54
+
+/* Control request for unregistering a HID device.
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_REGISTER_HID
+ *	value:          Accessory assigned ID for the HID device
+ *	index:          0
+ *	data            none
+ */
+#define ACCESSORY_UNREGISTER_HID         55
+
+/* Control request for sending the HID report descriptor.
+ * If the HID descriptor is longer than the endpoint zero max packet size,
+ * the descriptor will be sent in multiple ACCESSORY_SET_HID_REPORT_DESC
+ * commands. The data for the descriptor must be sent sequentially
+ * if multiple packets are needed.
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_SET_HID_REPORT_DESC
+ *	value:          Accessory assigned ID for the HID device
+ *	index:          offset of data in descriptor
+ *                      (needed when HID descriptor is too big for one packet)
+ *	data            the HID report descriptor
+ */
+#define ACCESSORY_SET_HID_REPORT_DESC         56
+
+/* Control request for sending HID events.
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_SEND_HID_EVENT
+ *	value:          Accessory assigned ID for the HID device
+ *	index:          0
+ *	data            the HID report for the event
+ */
+#define ACCESSORY_SEND_HID_EVENT         57
+
+/* Control request for setting the audio mode.
+ *
+ *	requestType:	USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_SET_AUDIO_MODE
+ *	value:          0 - no audio
+ *                     1 - device to host, 44100 16-bit stereo PCM
+ *	index:          0
+ *	data            none
+ */
+#define ACCESSORY_SET_AUDIO_MODE         58
+
+/* ioctls for retrieving strings set by the host */
+#define ACCESSORY_GET_STRING_MANUFACTURER   _IOW('M', 1, char[256])
+#define ACCESSORY_GET_STRING_MODEL          _IOW('M', 2, char[256])
+#define ACCESSORY_GET_STRING_DESCRIPTION    _IOW('M', 3, char[256])
+#define ACCESSORY_GET_STRING_VERSION        _IOW('M', 4, char[256])
+#define ACCESSORY_GET_STRING_URI            _IOW('M', 5, char[256])
+#define ACCESSORY_GET_STRING_SERIAL         _IOW('M', 6, char[256])
+/* returns 1 if there is a start request pending */
+#define ACCESSORY_IS_START_REQUESTED        _IO('M', 7)
+/* returns audio mode (set via the ACCESSORY_SET_AUDIO_MODE control request) */
+#define ACCESSORY_GET_AUDIO_MODE            _IO('M', 8)
+
+#endif /* _UAPI_LINUX_USB_F_ACCESSORY_H */
