1 files changed, 788 insertions, 0 deletions

diff --git a/drivers/usb/gadget/f_accessory.c b/drivers/usb/gadget/f_accessory.c
new file mode 100644
index 00000000000..ae65faaf3d7
--- /dev/null
+++ b/drivers/usb/gadget/f_accessory.c
@@ -0,0 +1,788 @@
+/*
+ * 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/usb.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/f_accessory.h>
+
+#define BULK_BUFFER_SIZE    16384
+#define ACC_STRING_SIZE     256
+
+#define PROTOCOL_VERSION    1
+
+/* 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_dev {
+        struct usb_function function;
+        struct usb_composite_dev *cdev;
+        spinlock_t lock;
+
+        struct usb_ep *ep_in;
+        struct usb_ep *ep_out;
+
+        /* set to 1 when we connect */
+        int online:1;
+        /* 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;
+
+        /* 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;
+        struct delayed_work work;
+};
+
+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;
+
+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->online = 0;
+        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 != 0)
+                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 != 0)
+                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 int __init 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;
+
+        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:
+        printk(KERN_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;
+        int r = count, xfer;
+        int ret = 0;
+
+        pr_debug("acc_read(%d)\n", count);
+
+        if (dev->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;
+        }
+
+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;
+                usb_ep_dequeue(dev->ep_out, req);
+                goto done;
+        }
+        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 %d\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 %d\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;
+        int r = count, xfer;
+        int ret;
+
+        pr_debug("acc_write(%d)\n", count);
+
+        if (!dev->online || dev->disconnected)
+                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;
+                else
+                        xfer = count;
+                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 %d\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;
+        }
+        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));
+        _acc_dev->disconnected = 0;
+        return 0;
+}
+
+/* file operations for /dev/acc_usb */
+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 struct miscdevice acc_device = {
+        .minor = MISC_DYNAMIC_MINOR,
+        .name = "usb_accessory",
+        .fops = &acc_fops,
+};
+
+
+static int acc_ctrlrequest(struct usb_composite_dev *cdev,
+                                const struct usb_ctrlrequest *ctrl)
+{
+        struct acc_dev  *dev = _acc_dev;
+        int     value = -EOPNOTSUPP;
+        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);
+
+/*
+        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->work, msecs_to_jiffies(10));
+                        value = 0;
+                } 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_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) {
+                if (b_request == ACCESSORY_GET_PROTOCOL) {
+                        *((u16 *)cdev->req->buf) = PROTOCOL_VERSION;
+                        value = sizeof(u16);
+
+                        /* clear any strings 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;
+                }
+        }
+
+        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__);
+        }
+
+        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;
+}
+
+static int
+acc_function_bind(struct usb_configuration *c, struct usb_function *f)
+{
+        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);
+
+        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 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;
+
+        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);
+}
+
+static void acc_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_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);
+        config_ep_by_speed(cdev->gadget, f, dev->ep_in);
+        ret = usb_ep_enable(dev->ep_in);
+        if (ret)
+                return ret;
+        config_ep_by_speed(cdev->gadget, f, dev->ep_out);
+        ret = usb_ep_enable(dev->ep_out);
+        if (ret) {
+                usb_ep_disable(dev->ep_in);
+                return ret;
+        }
+
+        dev->online = 1;
+
+        /* 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);
+        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_bind_config(struct usb_configuration *c)
+{
+        struct acc_dev *dev = _acc_dev;
+        int ret;
+
+        printk(KERN_INFO "acc_bind_config\n");
+
+        /* allocate a string ID for our interface */
+        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;
+        dev->function.name = "accessory";
+        dev->function.strings = acc_strings,
+        dev->function.descriptors = fs_acc_descs;
+        dev->function.hs_descriptors = hs_acc_descs;
+        dev->function.bind = acc_function_bind;
+        dev->function.unbind = acc_function_unbind;
+        dev->function.set_alt = acc_function_set_alt;
+        dev->function.disable = acc_function_disable;
+
+        return usb_add_function(c, &dev->function);
+}
+
+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_DELAYED_WORK(&dev->work, acc_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);
+        printk(KERN_ERR "USB accessory gadget driver failed to initialize\n");
+        return ret;
+}
+
+static void acc_cleanup(void)
+{
+        misc_deregister(&acc_device);
+        kfree(_acc_dev);
+        _acc_dev = NULL;
+}