--- /dev/null
+/*
+ * Configurable Composite Gadget
+ *
+ * Initially contributed as "Android Composite Gdaget" by:
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *         Benoit Goby <benoit@android.com>
+ *
+ * Tailoring it to become a generic Configurable Composite Gadget is
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+#include <linux/platform_device.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/gadget.h>
+
+#include "gadget_chips.h"
+
+/*
+ * Kbuild is not very cooperative with respect to linking separately
+ * compiled library objects into one module.  So for now we won't use
+ * separate compilation ... ensuring init/exit sections work to shrink
+ * the runtime footprint, and giving us at least some parts of what
+ * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
+ */
+#include "../../usb/gadget/usbstring.c"
+#include "../../usb/gadget/config.c"
+#include "../../usb/gadget/epautoconf.c"
+#include "../../usb/gadget/composite.c"
+
+#include "../../usb/gadget/f_mass_storage.c"
+#include "../../usb/gadget/u_serial.c"
+#include "../../usb/gadget/f_acm.c"
+#define USB_ETH_RNDIS y
+#include "../../usb/gadget/f_rndis.c"
+#include "../../usb/gadget/rndis.c"
+#include "../../usb/gadget/u_ether.c"
+#include "../../usb/gadget/f_fs.c"
+
+MODULE_AUTHOR("Mike Lockwood");
+MODULE_DESCRIPTION("Configurable Composite USB Gadget");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+
+static const char longname[] = "Configurable Composite Gadget";
+
+/* Default vendor and product IDs, overridden by userspace */
+#define VENDOR_ID              0x1d6b /* Linux Foundation */
+#define PRODUCT_ID             0x0107
+
+struct ccg_usb_function {
+       char *name;
+       void *config;
+
+       struct device *dev;
+       char *dev_name;
+       struct device_attribute **attributes;
+
+       /* for ccg_dev.enabled_functions */
+       struct list_head enabled_list;
+
+       /* Optional: initialization during gadget bind */
+       int (*init)(struct ccg_usb_function *, struct usb_composite_dev *);
+       /* Optional: cleanup during gadget unbind */
+       void (*cleanup)(struct ccg_usb_function *);
+
+       int (*bind_config)(struct ccg_usb_function *,
+                          struct usb_configuration *);
+
+       /* Optional: called when the configuration is removed */
+       void (*unbind_config)(struct ccg_usb_function *,
+                             struct usb_configuration *);
+       /* Optional: handle ctrl requests before the device is configured */
+       int (*ctrlrequest)(struct ccg_usb_function *,
+                          struct usb_composite_dev *,
+                          const struct usb_ctrlrequest *);
+};
+
+struct ccg_dev {
+       struct ccg_usb_function **functions;
+       struct list_head enabled_functions;
+       struct usb_composite_dev *cdev;
+       struct device *dev;
+
+       bool enabled;
+       struct mutex mutex;
+       bool connected;
+       bool sw_connected;
+       struct work_struct work;
+};
+
+static struct class *ccg_class;
+static struct ccg_dev *_ccg_dev;
+static int ccg_bind_config(struct usb_configuration *c);
+static void ccg_unbind_config(struct usb_configuration *c);
+
+
+static struct usb_device_descriptor device_desc = {
+       .bLength              = sizeof(device_desc),
+       .bDescriptorType      = USB_DT_DEVICE,
+       .bcdUSB               = __constant_cpu_to_le16(0x0200),
+       .bDeviceClass         = USB_CLASS_PER_INTERFACE,
+       .idVendor             = __constant_cpu_to_le16(VENDOR_ID),
+       .idProduct            = __constant_cpu_to_le16(PRODUCT_ID),
+       .bcdDevice            = __constant_cpu_to_le16(0xffff),
+       .bNumConfigurations   = 1,
+};
+
+static struct usb_configuration ccg_config_driver = {
+       .label          = "ccg",
+       .unbind         = ccg_unbind_config,
+       .bConfigurationValue = 1,
+       .bmAttributes   = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
+       .bMaxPower      = 0xFA, /* 500ma */
+};
+
+static void ccg_work(struct work_struct *data)
+{
+       struct ccg_dev *dev = container_of(data, struct ccg_dev, work);
+       struct usb_composite_dev *cdev = dev->cdev;
+       static char *disconnected[2] = { "USB_STATE=DISCONNECTED", NULL };
+       static char *connected[2]    = { "USB_STATE=CONNECTED", NULL };
+       static char *configured[2]   = { "USB_STATE=CONFIGURED", NULL };
+       char **uevent_envp = NULL;
+       unsigned long flags;
+
+       spin_lock_irqsave(&cdev->lock, flags);
+       if (cdev->config)
+               uevent_envp = configured;
+       else if (dev->connected != dev->sw_connected)
+               uevent_envp = dev->connected ? connected : disconnected;
+       dev->sw_connected = dev->connected;
+       spin_unlock_irqrestore(&cdev->lock, flags);
+
+       if (uevent_envp) {
+               kobject_uevent_env(&dev->dev->kobj, KOBJ_CHANGE, uevent_envp);
+               pr_info("%s: sent uevent %s\n", __func__, uevent_envp[0]);
+       } else {
+               pr_info("%s: did not send uevent (%d %d %p)\n", __func__,
+                        dev->connected, dev->sw_connected, cdev->config);
+       }
+}
+
+
+/*-------------------------------------------------------------------------*/
+/* Supported functions initialization */
+
+#define MAX_ACM_INSTANCES 4
+struct acm_function_config {
+       int instances;
+};
+
+static int
+acm_function_init(struct ccg_usb_function *f, struct usb_composite_dev *cdev)
+{
+       f->config = kzalloc(sizeof(struct acm_function_config), GFP_KERNEL);
+       if (!f->config)
+               return -ENOMEM;
+
+       return gserial_setup(cdev->gadget, MAX_ACM_INSTANCES);
+}
+
+static void acm_function_cleanup(struct ccg_usb_function *f)
+{
+       gserial_cleanup();
+       kfree(f->config);
+       f->config = NULL;
+}
+
+static int
+acm_function_bind_config(struct ccg_usb_function *f,
+               struct usb_configuration *c)
+{
+       int i;
+       int ret = 0;
+       struct acm_function_config *config = f->config;
+
+       for (i = 0; i < config->instances; i++) {
+               ret = acm_bind_config(c, i);
+               if (ret) {
+                       pr_err("Could not bind acm%u config\n", i);
+                       break;
+               }
+       }
+
+       return ret;
+}
+
+static ssize_t acm_instances_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct acm_function_config *config = f->config;
+       return sprintf(buf, "%d\n", config->instances);
+}
+
+static ssize_t acm_instances_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct acm_function_config *config = f->config;
+       int value;
+       int ret = 0;
+
+       ret = kstrtoint(buf, 10, &value);
+       if (ret)
+               return ret;
+
+       if (value > MAX_ACM_INSTANCES)
+               return -EINVAL;
+
+       config->instances = value;
+
+       return size;
+}
+
+static DEVICE_ATTR(instances, S_IRUGO | S_IWUSR, acm_instances_show,
+                                                acm_instances_store);
+static struct device_attribute *acm_function_attributes[] = {
+       &dev_attr_instances,
+       NULL
+};
+
+static struct ccg_usb_function acm_function = {
+       .name           = "acm",
+       .init           = acm_function_init,
+       .cleanup        = acm_function_cleanup,
+       .bind_config    = acm_function_bind_config,
+       .attributes     = acm_function_attributes,
+};
+
+struct rndis_function_config {
+       u8      ethaddr[ETH_ALEN];
+       u32     vendorID;
+       char    manufacturer[256];
+       /* "Wireless" RNDIS; auto-detected by Windows */
+       bool    wceis;
+};
+
+static int rndis_function_init(struct ccg_usb_function *f,
+                              struct usb_composite_dev *cdev)
+{
+       f->config = kzalloc(sizeof(struct rndis_function_config), GFP_KERNEL);
+       if (!f->config)
+               return -ENOMEM;
+       return 0;
+}
+
+static void rndis_function_cleanup(struct ccg_usb_function *f)
+{
+       kfree(f->config);
+       f->config = NULL;
+}
+
+static int rndis_function_bind_config(struct ccg_usb_function *f,
+                                     struct usb_configuration *c)
+{
+       int ret;
+       struct rndis_function_config *rndis = f->config;
+
+       if (!rndis) {
+               pr_err("%s: rndis_pdata\n", __func__);
+               return -1;
+       }
+
+       pr_info("%s MAC: %02X:%02X:%02X:%02X:%02X:%02X\n", __func__,
+               rndis->ethaddr[0], rndis->ethaddr[1], rndis->ethaddr[2],
+               rndis->ethaddr[3], rndis->ethaddr[4], rndis->ethaddr[5]);
+
+       ret = gether_setup_name(c->cdev->gadget, rndis->ethaddr, "rndis");
+       if (ret) {
+               pr_err("%s: gether_setup failed\n", __func__);
+               return ret;
+       }
+
+       if (rndis->wceis) {
+               /* "Wireless" RNDIS; auto-detected by Windows */
+               rndis_iad_descriptor.bFunctionClass =
+                                               USB_CLASS_WIRELESS_CONTROLLER;
+               rndis_iad_descriptor.bFunctionSubClass = 0x01;
+               rndis_iad_descriptor.bFunctionProtocol = 0x03;
+               rndis_control_intf.bInterfaceClass =
+                                               USB_CLASS_WIRELESS_CONTROLLER;
+               rndis_control_intf.bInterfaceSubClass =  0x01;
+               rndis_control_intf.bInterfaceProtocol =  0x03;
+       }
+
+       return rndis_bind_config_vendor(c, rndis->ethaddr, rndis->vendorID,
+                                          rndis->manufacturer);
+}
+
+static void rndis_function_unbind_config(struct ccg_usb_function *f,
+                                               struct usb_configuration *c)
+{
+       gether_cleanup();
+}
+
+static ssize_t rndis_manufacturer_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+       return sprintf(buf, "%s\n", config->manufacturer);
+}
+
+static ssize_t rndis_manufacturer_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+
+       if (size >= sizeof(config->manufacturer))
+               return -EINVAL;
+       memcpy(config->manufacturer, buf, size);
+       config->manufacturer[size] = 0;
+
+       return size;
+}
+
+static DEVICE_ATTR(manufacturer, S_IRUGO | S_IWUSR, rndis_manufacturer_show,
+                                                   rndis_manufacturer_store);
+
+static ssize_t rndis_wceis_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+       return sprintf(buf, "%d\n", config->wceis);
+}
+
+static ssize_t rndis_wceis_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+       int value;
+       int ret;
+
+       ret = kstrtoint(buf, 10, &value);
+       if (ret)
+               return ret;
+
+       config->wceis = value;
+
+       return size;
+}
+
+static DEVICE_ATTR(wceis, S_IRUGO | S_IWUSR, rndis_wceis_show,
+                                            rndis_wceis_store);
+
+static ssize_t rndis_ethaddr_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *rndis = f->config;
+       return sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+               rndis->ethaddr[0], rndis->ethaddr[1], rndis->ethaddr[2],
+               rndis->ethaddr[3], rndis->ethaddr[4], rndis->ethaddr[5]);
+}
+
+static ssize_t rndis_ethaddr_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *rndis = f->config;
+       unsigned char tmp[6];
+
+       if (sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+                  tmp + 0, tmp + 1, tmp + 2, tmp + 3, tmp + 4, tmp + 5) !=
+           ETH_ALEN)
+               return -EINVAL;
+
+       memcpy(rndis->ethaddr, tmp, ETH_ALEN);
+
+       return ETH_ALEN;
+
+}
+
+static DEVICE_ATTR(ethaddr, S_IRUGO | S_IWUSR, rndis_ethaddr_show,
+                                              rndis_ethaddr_store);
+
+static ssize_t rndis_vendorID_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+       return sprintf(buf, "%04x\n", config->vendorID);
+}
+
+static ssize_t rndis_vendorID_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct ccg_usb_function *f = dev_get_drvdata(dev);
+       struct rndis_function_config *config = f->config;
+       int value;
+       int ret;
+
+       ret = kstrtou32(buf, 16, &value);
+       if (ret)
+               return ret;
+
+       config->vendorID = value;
+
+       return size;
+}
+
+static DEVICE_ATTR(vendorID, S_IRUGO | S_IWUSR, rndis_vendorID_show,
+                                               rndis_vendorID_store);
+
+static struct device_attribute *rndis_function_attributes[] = {
+       &dev_attr_manufacturer,
+       &dev_attr_wceis,
+       &dev_attr_ethaddr,
+       &dev_attr_vendorID,
+       NULL
+};
+
+static struct ccg_usb_function rndis_function = {
+       .name           = "rndis",
+       .init           = rndis_function_init,
+       .cleanup        = rndis_function_cleanup,
+       .bind_config    = rndis_function_bind_config,
+       .unbind_config  = rndis_function_unbind_config,
+       .attributes     = rndis_function_attributes,
+};
+
+static int mass_storage_function_init(struct ccg_usb_function *f,
+                                       struct usb_composite_dev *cdev)
+{
+       struct fsg_config fsg;
+       struct fsg_common *common;
+       int err;
+
+       memset(&fsg, 0, sizeof fsg);
+       fsg.nluns = 1;
+       fsg.luns[0].removable = 1;
+       fsg.vendor_name = iManufacturer;
+       fsg.product_name = iProduct;
+
+       common = fsg_common_init(NULL, cdev, &fsg);
+       if (IS_ERR(common))
+               return PTR_ERR(common);
+
+       err = sysfs_create_link(&f->dev->kobj,
+                               &common->luns[0].dev.kobj,
+                               "lun");
+       if (err) {
+               fsg_common_put(common);
+               return err;
+       }
+
+       f->config = common;
+       return 0;
+}
+
+static void mass_storage_function_cleanup(struct ccg_usb_function *f)
+{
+       fsg_common_put(f->config);
+       f->config = NULL;
+}
+
+static int mass_storage_function_bind_config(struct ccg_usb_function *f,
+                                            struct usb_configuration *c)
+{
+       struct fsg_common *common = f->config;
+       return fsg_bind_config(c->cdev, c, common);
+}
+
+static struct ccg_usb_function mass_storage_function = {
+       .name           = "mass_storage",
+       .init           = mass_storage_function_init,
+       .cleanup        = mass_storage_function_cleanup,
+       .bind_config    = mass_storage_function_bind_config,
+};
+
+static struct ccg_usb_function *supported_functions[] = {
+       &acm_function,
+       &rndis_function,
+       &mass_storage_function,
+       NULL
+};
+
+
+static int ccg_init_functions(struct ccg_usb_function **functions,
+                                 struct usb_composite_dev *cdev)
+{
+       struct ccg_dev *dev = _ccg_dev;
+       struct ccg_usb_function *f;
+       struct device_attribute **attrs;
+       struct device_attribute *attr;
+       int err;
+       int index = 0;
+
+       for (; (f = *functions++); index++) {
+               f->dev_name = kasprintf(GFP_KERNEL, "f_%s", f->name);
+               if (!f->dev_name) {
+                       pr_err("%s: Failed to alloc name %s", __func__,
+                              f->name);
+                       err = -ENOMEM;
+                       goto err_alloc;
+               }
+               f->dev = device_create(ccg_class, dev->dev,
+                               MKDEV(0, index), f, f->dev_name);
+               if (IS_ERR(f->dev)) {
+                       pr_err("%s: Failed to create dev %s", __func__,
+                                                       f->dev_name);
+                       err = PTR_ERR(f->dev);
+                       f->dev = NULL;
+                       goto err_create;
+               }
+
+               if (f->init) {
+                       err = f->init(f, cdev);
+                       if (err) {
+                               pr_err("%s: Failed to init %s", __func__,
+                                                               f->name);
+                               goto err_out;
+                       }
+               }
+
+               attrs = f->attributes;
+               if (attrs) {
+                       while ((attr = *attrs++) && !err)
+                               err = device_create_file(f->dev, attr);
+               }
+               if (err) {
+                       pr_err("%s: Failed to create function %s attributes",
+                                       __func__, f->name);
+                       goto err_uninit;
+               }
+       }
+       return 0;
+
+err_uninit:
+       if (f->cleanup)
+               f->cleanup(f);
+err_out:
+       device_destroy(ccg_class, f->dev->devt);
+       f->dev = NULL;
+err_create:
+       kfree(f->dev_name);
+err_alloc:
+       return err;
+}
+
+static void ccg_cleanup_functions(struct ccg_usb_function **functions)
+{
+       struct ccg_usb_function *f;
+
+       while (*functions) {
+               f = *functions++;
+
+               if (f->dev) {
+                       if (f->cleanup)
+                               f->cleanup(f);
+                       device_destroy(ccg_class, f->dev->devt);
+                       kfree(f->dev_name);
+               }
+       }
+}
+
+static int ccg_bind_enabled_functions(struct ccg_dev *dev,
+                                     struct usb_configuration *c)
+{
+       struct ccg_usb_function *f;
+       int ret;
+
+       list_for_each_entry(f, &dev->enabled_functions, enabled_list) {
+               ret = f->bind_config(f, c);
+               if (ret) {
+                       pr_err("%s: %s failed", __func__, f->name);
+                       return ret;
+               }
+       }
+       return 0;
+}
+
+static void ccg_unbind_enabled_functions(struct ccg_dev *dev,
+                                        struct usb_configuration *c)
+{
+       struct ccg_usb_function *f;
+
+       list_for_each_entry(f, &dev->enabled_functions, enabled_list)
+               if (f->unbind_config)
+                       f->unbind_config(f, c);
+}
+
+static int ccg_enable_function(struct ccg_dev *dev, char *name)
+{
+       struct ccg_usb_function **functions = dev->functions;
+       struct ccg_usb_function *f;
+       while ((f = *functions++)) {
+               if (!strcmp(name, f->name)) {
+                       list_add_tail(&f->enabled_list,
+                                               &dev->enabled_functions);
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
+
+/*-------------------------------------------------------------------------*/
+/* /sys/class/ccg_usb/ccg%d/ interface */
+
+static ssize_t
+functions_show(struct device *pdev, struct device_attribute *attr, char *buf)
+{
+       struct ccg_dev *dev = dev_get_drvdata(pdev);
+       struct ccg_usb_function *f;
+       char *buff = buf;
+
+       mutex_lock(&dev->mutex);
+
+       list_for_each_entry(f, &dev->enabled_functions, enabled_list)
+               buff += sprintf(buff, "%s,", f->name);
+
+       mutex_unlock(&dev->mutex);
+
+       if (buff != buf)
+               *(buff-1) = '\n';
+       return buff - buf;
+}
+
+static ssize_t
+functions_store(struct device *pdev, struct device_attribute *attr,
+                              const char *buff, size_t size)
+{
+       struct ccg_dev *dev = dev_get_drvdata(pdev);
+       char *name;
+       char buf[256], *b;
+       int err;
+
+       buff = skip_spaces(buff);
+       if (!*buff)
+               return -EINVAL;
+
+       mutex_lock(&dev->mutex);
+
+       if (dev->enabled) {
+               mutex_unlock(&dev->mutex);
+               return -EBUSY;
+       }
+
+       INIT_LIST_HEAD(&dev->enabled_functions);
+
+       strlcpy(buf, buff, sizeof(buf));
+       b = strim(buf);
+
+       while (b) {
+               name = strsep(&b, ",");
+               if (name) {
+                       err = ccg_enable_function(dev, name);
+                       if (err)
+                               pr_err("ccg_usb: Cannot enable '%s'", name);
+               }
+       }
+
+       mutex_unlock(&dev->mutex);
+
+       return size;
+}
+
+static ssize_t enable_show(struct device *pdev, struct device_attribute *attr,
+                          char *buf)
+{
+       struct ccg_dev *dev = dev_get_drvdata(pdev);
+       return sprintf(buf, "%d\n", dev->enabled);
+}
+
+static ssize_t enable_store(struct device *pdev, struct device_attribute *attr,
+                           const char *buff, size_t size)
+{
+       struct ccg_dev *dev = dev_get_drvdata(pdev);
+       struct usb_composite_dev *cdev = dev->cdev;
+       int enabled = 0;
+
+       mutex_lock(&dev->mutex);
+
+       sscanf(buff, "%d", &enabled);
+       if (enabled && !dev->enabled) {
+               int ret;
+
+               cdev->next_string_id = 0;
+               /*
+                * Update values in composite driver's copy of
+                * device descriptor.
+                */
+               cdev->desc.bDeviceClass = device_desc.bDeviceClass;
+               cdev->desc.bDeviceSubClass = device_desc.bDeviceSubClass;
+               cdev->desc.bDeviceProtocol = device_desc.bDeviceProtocol;
+               cdev->desc.idVendor = idVendor;
+               cdev->desc.idProduct = idProduct;
+               cdev->desc.bcdDevice = bcdDevice;
+
+               usb_add_config(cdev, &ccg_config_driver, ccg_bind_config);
+               dev->enabled = true;
+               ret = usb_gadget_connect(cdev->gadget);
+               if (ret) {
+                       dev->enabled = false;
+                       usb_remove_config(cdev, &ccg_config_driver);
+               }
+       } else if (!enabled && dev->enabled) {
+               usb_gadget_disconnect(cdev->gadget);
+               /* Cancel pending control requests */
+               usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
+               usb_remove_config(cdev, &ccg_config_driver);
+               dev->enabled = false;
+       } else {
+               pr_err("ccg_usb: already %s\n",
+                       dev->enabled ? "enabled" : "disabled");
+       }
+
+       mutex_unlock(&dev->mutex);
+       return size;
+}
+
+static ssize_t state_show(struct device *pdev, struct device_attribute *attr,
+                          char *buf)
+{
+       struct ccg_dev *dev = dev_get_drvdata(pdev);
+       struct usb_composite_dev *cdev = dev->cdev;
+       char *state = "DISCONNECTED";
+       unsigned long flags;
+
+       if (!cdev)
+               goto out;
+
+       spin_lock_irqsave(&cdev->lock, flags);
+       if (cdev->config)
+               state = "CONFIGURED";
+       else if (dev->connected)
+               state = "CONNECTED";
+       spin_unlock_irqrestore(&cdev->lock, flags);
+out:
+       return sprintf(buf, "%s\n", state);
+}
+
+#define DESCRIPTOR_ATTR(field, format_string)                          \
+static ssize_t                                                         \
+field ## _show(struct device *dev, struct device_attribute *attr,      \
+               char *buf)                                              \
+{                                                                      \
+       return sprintf(buf, format_string, device_desc.field);          \
+}                                                                      \
+static ssize_t                                                         \
+field ## _store(struct device *dev, struct device_attribute *attr,     \
+               const char *buf, size_t size)                           \
+{                                                                      \
+       int value;                                                      \
+       if (sscanf(buf, format_string, &value) == 1) {                  \
+               device_desc.field = value;                              \
+               return size;                                            \
+       }                                                               \
+       return -1;                                                      \
+}                                                                      \
+static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, field ## _show, field ## _store);
+
+DESCRIPTOR_ATTR(bDeviceClass, "%d\n")
+DESCRIPTOR_ATTR(bDeviceSubClass, "%d\n")
+DESCRIPTOR_ATTR(bDeviceProtocol, "%d\n")
+
+static DEVICE_ATTR(functions, S_IRUGO | S_IWUSR, functions_show,
+                                                functions_store);
+static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, enable_show, enable_store);
+static DEVICE_ATTR(state, S_IRUGO, state_show, NULL);
+
+static struct device_attribute *ccg_usb_attributes[] = {
+       &dev_attr_bDeviceClass,
+       &dev_attr_bDeviceSubClass,
+       &dev_attr_bDeviceProtocol,
+       &dev_attr_functions,
+       &dev_attr_enable,
+       &dev_attr_state,
+       NULL
+};
+
+/*-------------------------------------------------------------------------*/
+/* Composite driver */
+
+static int ccg_bind_config(struct usb_configuration *c)
+{
+       struct ccg_dev *dev = _ccg_dev;
+       int ret = 0;
+
+       ret = ccg_bind_enabled_functions(dev, c);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static void ccg_unbind_config(struct usb_configuration *c)
+{
+       struct ccg_dev *dev = _ccg_dev;
+
+       ccg_unbind_enabled_functions(dev, c);
+
+       usb_ep_autoconfig_reset(dev->cdev->gadget);
+}
+
+static int ccg_bind(struct usb_composite_dev *cdev)
+{
+       struct ccg_dev *dev = _ccg_dev;
+       struct usb_gadget       *gadget = cdev->gadget;
+       int                     gcnum, ret;
+
+       /*
+        * Start disconnected. Userspace will connect the gadget once
+        * it is done configuring the functions.
+        */
+       usb_gadget_disconnect(gadget);
+
+       ret = ccg_init_functions(dev->functions, cdev);
+       if (ret)
+               return ret;
+
+       gcnum = usb_gadget_controller_number(gadget);
+       if (gcnum >= 0)
+               device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
+       else {
+               pr_warning("%s: controller '%s' not recognized\n",
+                       longname, gadget->name);
+               device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
+       }
+
+       usb_gadget_set_selfpowered(gadget);
+       dev->cdev = cdev;
+
+       return 0;
+}
+
+static int ccg_usb_unbind(struct usb_composite_dev *cdev)
+{
+       struct ccg_dev *dev = _ccg_dev;
+
+       cancel_work_sync(&dev->work);
+       ccg_cleanup_functions(dev->functions);
+       return 0;
+}
+
+static struct usb_composite_driver ccg_usb_driver = {
+       .name           = "configurable_usb",
+       .dev            = &device_desc,
+       .unbind         = ccg_usb_unbind,
+       .needs_serial   = true,
+       .iManufacturer  = "Linux Foundation",
+       .iProduct       = longname,
+       .iSerialNumber  = "1234567890123456",
+};
+
+static int ccg_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *c)
+{
+       struct ccg_dev          *dev = _ccg_dev;
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+       struct usb_request              *req = cdev->req;
+       struct ccg_usb_function *f;
+       int value = -EOPNOTSUPP;
+       unsigned long flags;
+
+       req->zero = 0;
+       req->complete = composite_setup_complete;
+       req->length = 0;
+       gadget->ep0->driver_data = cdev;
+
+       list_for_each_entry(f, &dev->enabled_functions, enabled_list) {
+               if (f->ctrlrequest) {
+                       value = f->ctrlrequest(f, cdev, c);
+                       if (value >= 0)
+                               break;
+               }
+       }
+
+       if (value < 0)
+               value = composite_setup(gadget, c);
+
+       spin_lock_irqsave(&cdev->lock, flags);
+       if (!dev->connected) {
+               dev->connected = 1;
+               schedule_work(&dev->work);
+       } else if (c->bRequest == USB_REQ_SET_CONFIGURATION &&
+                                               cdev->config) {
+               schedule_work(&dev->work);
+       }
+       spin_unlock_irqrestore(&cdev->lock, flags);
+
+       return value;
+}
+
+static void ccg_disconnect(struct usb_gadget *gadget)
+{
+       struct ccg_dev *dev = _ccg_dev;
+       struct usb_composite_dev *cdev = get_gadget_data(gadget);
+       unsigned long flags;
+
+       composite_disconnect(gadget);
+
+       spin_lock_irqsave(&cdev->lock, flags);
+       dev->connected = 0;
+       schedule_work(&dev->work);
+       spin_unlock_irqrestore(&cdev->lock, flags);
+}
+
+static int ccg_create_device(struct ccg_dev *dev)
+{
+       struct device_attribute **attrs = ccg_usb_attributes;
+       struct device_attribute *attr;
+       int err;
+
+       dev->dev = device_create(ccg_class, NULL, MKDEV(0, 0), NULL, "ccg0");
+       if (IS_ERR(dev->dev))
+               return PTR_ERR(dev->dev);
+
+       dev_set_drvdata(dev->dev, dev);
+
+       while ((attr = *attrs++)) {
+               err = device_create_file(dev->dev, attr);
+               if (err) {
+                       device_destroy(ccg_class, dev->dev->devt);
+                       return err;
+               }
+       }
+       return 0;
+}
+
+
+static int __init init(void)
+{
+       struct ccg_dev *dev;
+       int err;
+
+       ccg_class = class_create(THIS_MODULE, "ccg_usb");
+       if (IS_ERR(ccg_class))
+               return PTR_ERR(ccg_class);
+
+       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+
+       dev->functions = supported_functions;
+       INIT_LIST_HEAD(&dev->enabled_functions);
+       INIT_WORK(&dev->work, ccg_work);
+       mutex_init(&dev->mutex);
+
+       err = ccg_create_device(dev);
+       if (err) {
+               class_destroy(ccg_class);
+               kfree(dev);
+               return err;
+       }
+
+       _ccg_dev = dev;
+
+       /* Override composite driver functions */
+       composite_driver.setup = ccg_setup;
+       composite_driver.disconnect = ccg_disconnect;
+
+       err = usb_composite_probe(&ccg_usb_driver, ccg_bind);
+       if (err) {
+               class_destroy(ccg_class);
+               kfree(dev);
+       }
+
+       return err;
+}
+module_init(init);
+
+static void __exit cleanup(void)
+{
+       usb_composite_unregister(&ccg_usb_driver);
+       class_destroy(ccg_class);
+       kfree(_ccg_dev);
+       _ccg_dev = NULL;
+}
+module_exit(cleanup);