Add qemu 2.4.0
[kvmfornfv.git] / qemu / roms / u-boot / drivers / usb / gadget / composite.c
diff --git a/qemu/roms/u-boot/drivers/usb/gadget/composite.c b/qemu/roms/u-boot/drivers/usb/gadget/composite.c
new file mode 100644 (file)
index 0000000..7bd2562
--- /dev/null
@@ -0,0 +1,1091 @@
+/*
+ * composite.c - infrastructure for Composite USB Gadgets
+ *
+ * Copyright (C) 2006-2008 David Brownell
+ * U-boot porting: Lukasz Majewski <l.majewski@samsung.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+#undef DEBUG
+
+#include <linux/bitops.h>
+#include <linux/usb/composite.h>
+
+#define USB_BUFSIZ     4096
+
+static struct usb_composite_driver *composite;
+
+/**
+ * usb_add_function() - add a function to a configuration
+ * @config: the configuration
+ * @function: the function being added
+ * Context: single threaded during gadget setup
+ *
+ * After initialization, each configuration must have one or more
+ * functions added to it.  Adding a function involves calling its @bind()
+ * method to allocate resources such as interface and string identifiers
+ * and endpoints.
+ *
+ * This function returns the value of the function's bind(), which is
+ * zero for success else a negative errno value.
+ */
+int usb_add_function(struct usb_configuration *config,
+               struct usb_function *function)
+{
+       int     value = -EINVAL;
+
+       debug("adding '%s'/%p to config '%s'/%p\n",
+                       function->name, function,
+                       config->label, config);
+
+       if (!function->set_alt || !function->disable)
+               goto done;
+
+       function->config = config;
+       list_add_tail(&function->list, &config->functions);
+
+       if (function->bind) {
+               value = function->bind(config, function);
+               if (value < 0) {
+                       list_del(&function->list);
+                       function->config = NULL;
+               }
+       } else
+               value = 0;
+
+       if (!config->fullspeed && function->descriptors)
+               config->fullspeed = 1;
+       if (!config->highspeed && function->hs_descriptors)
+               config->highspeed = 1;
+
+done:
+       if (value)
+               debug("adding '%s'/%p --> %d\n",
+                               function->name, function, value);
+       return value;
+}
+
+/**
+ * usb_function_deactivate - prevent function and gadget enumeration
+ * @function: the function that isn't yet ready to respond
+ *
+ * Blocks response of the gadget driver to host enumeration by
+ * preventing the data line pullup from being activated.  This is
+ * normally called during @bind() processing to change from the
+ * initial "ready to respond" state, or when a required resource
+ * becomes available.
+ *
+ * For example, drivers that serve as a passthrough to a userspace
+ * daemon can block enumeration unless that daemon (such as an OBEX,
+ * MTP, or print server) is ready to handle host requests.
+ *
+ * Not all systems support software control of their USB peripheral
+ * data pullups.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_function_deactivate(struct usb_function *function)
+{
+       struct usb_composite_dev        *cdev = function->config->cdev;
+       int                             status = 0;
+
+       if (cdev->deactivations == 0)
+               status = usb_gadget_disconnect(cdev->gadget);
+       if (status == 0)
+               cdev->deactivations++;
+
+       return status;
+}
+
+/**
+ * usb_function_activate - allow function and gadget enumeration
+ * @function: function on which usb_function_activate() was called
+ *
+ * Reverses effect of usb_function_deactivate().  If no more functions
+ * are delaying their activation, the gadget driver will respond to
+ * host enumeration procedures.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_function_activate(struct usb_function *function)
+{
+       struct usb_composite_dev        *cdev = function->config->cdev;
+       int                             status = 0;
+
+       if (cdev->deactivations == 0)
+               status = -EINVAL;
+       else {
+               cdev->deactivations--;
+               if (cdev->deactivations == 0)
+                       status = usb_gadget_connect(cdev->gadget);
+       }
+
+       return status;
+}
+
+/**
+ * usb_interface_id() - allocate an unused interface ID
+ * @config: configuration associated with the interface
+ * @function: function handling the interface
+ * Context: single threaded during gadget setup
+ *
+ * usb_interface_id() is called from usb_function.bind() callbacks to
+ * allocate new interface IDs.  The function driver will then store that
+ * ID in interface, association, CDC union, and other descriptors.  It
+ * will also handle any control requests targetted at that interface,
+ * particularly changing its altsetting via set_alt().  There may
+ * also be class-specific or vendor-specific requests to handle.
+ *
+ * All interface identifier should be allocated using this routine, to
+ * ensure that for example different functions don't wrongly assign
+ * different meanings to the same identifier.  Note that since interface
+ * identifers are configuration-specific, functions used in more than
+ * one configuration (or more than once in a given configuration) need
+ * multiple versions of the relevant descriptors.
+ *
+ * Returns the interface ID which was allocated; or -ENODEV if no
+ * more interface IDs can be allocated.
+ */
+int usb_interface_id(struct usb_configuration *config,
+               struct usb_function *function)
+{
+       unsigned char id = config->next_interface_id;
+
+       if (id < MAX_CONFIG_INTERFACES) {
+               config->interface[id] = function;
+               config->next_interface_id = id + 1;
+               return id;
+       }
+       return -ENODEV;
+}
+
+static int config_buf(struct usb_configuration *config,
+               enum usb_device_speed speed, void *buf, u8 type)
+{
+       int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
+       void                            *next = buf + USB_DT_CONFIG_SIZE;
+       struct usb_descriptor_header    **descriptors;
+       struct usb_config_descriptor    *c = buf;
+       int                             status;
+       struct usb_function             *f;
+
+       /* write the config descriptor */
+       c = buf;
+       c->bLength = USB_DT_CONFIG_SIZE;
+       c->bDescriptorType = type;
+
+       c->bNumInterfaces = config->next_interface_id;
+       c->bConfigurationValue = config->bConfigurationValue;
+       c->iConfiguration = config->iConfiguration;
+       c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
+       c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
+
+       /* There may be e.g. OTG descriptors */
+       if (config->descriptors) {
+               status = usb_descriptor_fillbuf(next, len,
+                               config->descriptors);
+               if (status < 0)
+                       return status;
+               len -= status;
+               next += status;
+       }
+
+       /* add each function's descriptors */
+       list_for_each_entry(f, &config->functions, list) {
+               if (speed == USB_SPEED_HIGH)
+                       descriptors = f->hs_descriptors;
+               else
+                       descriptors = f->descriptors;
+               if (!descriptors)
+                       continue;
+               status = usb_descriptor_fillbuf(next, len,
+                       (const struct usb_descriptor_header **) descriptors);
+               if (status < 0)
+                       return status;
+               len -= status;
+               next += status;
+       }
+
+       len = next - buf;
+       c->wTotalLength = cpu_to_le16(len);
+       return len;
+}
+
+static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
+{
+       enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
+       struct usb_gadget               *gadget = cdev->gadget;
+       u8                              type = w_value >> 8;
+       int                             hs = 0;
+       struct usb_configuration        *c;
+
+       if (gadget_is_dualspeed(gadget)) {
+               if (gadget->speed == USB_SPEED_HIGH)
+                       hs = 1;
+               if (type == USB_DT_OTHER_SPEED_CONFIG)
+                       hs = !hs;
+               if (hs)
+                       speed = USB_SPEED_HIGH;
+       }
+
+       w_value &= 0xff;
+       list_for_each_entry(c, &cdev->configs, list) {
+               if (speed == USB_SPEED_HIGH) {
+                       if (!c->highspeed)
+                               continue;
+               } else {
+                       if (!c->fullspeed)
+                               continue;
+               }
+               if (w_value == 0)
+                       return config_buf(c, speed, cdev->req->buf, type);
+               w_value--;
+       }
+       return -EINVAL;
+}
+
+static int count_configs(struct usb_composite_dev *cdev, unsigned type)
+{
+       struct usb_gadget               *gadget = cdev->gadget;
+       unsigned                        count = 0;
+       int                             hs = 0;
+       struct usb_configuration        *c;
+
+       if (gadget_is_dualspeed(gadget)) {
+               if (gadget->speed == USB_SPEED_HIGH)
+                       hs = 1;
+               if (type == USB_DT_DEVICE_QUALIFIER)
+                       hs = !hs;
+       }
+       list_for_each_entry(c, &cdev->configs, list) {
+               /* ignore configs that won't work at this speed */
+               if (hs) {
+                       if (!c->highspeed)
+                               continue;
+               } else {
+                       if (!c->fullspeed)
+                               continue;
+               }
+               count++;
+       }
+       return count;
+}
+
+static void device_qual(struct usb_composite_dev *cdev)
+{
+       struct usb_qualifier_descriptor *qual = cdev->req->buf;
+
+       qual->bLength = sizeof(*qual);
+       qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
+       /* POLICY: same bcdUSB and device type info at both speeds */
+       qual->bcdUSB = cdev->desc.bcdUSB;
+       qual->bDeviceClass = cdev->desc.bDeviceClass;
+       qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
+       qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
+       /* ASSUME same EP0 fifo size at both speeds */
+       qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
+       qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
+       qual->bRESERVED = 0;
+}
+
+static void reset_config(struct usb_composite_dev *cdev)
+{
+       struct usb_function             *f;
+
+       debug("%s:\n", __func__);
+
+       list_for_each_entry(f, &cdev->config->functions, list) {
+               if (f->disable)
+                       f->disable(f);
+
+               bitmap_zero(f->endpoints, 32);
+       }
+       cdev->config = NULL;
+}
+
+static int set_config(struct usb_composite_dev *cdev,
+               const struct usb_ctrlrequest *ctrl, unsigned number)
+{
+       struct usb_gadget       *gadget = cdev->gadget;
+       unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
+       struct usb_descriptor_header **descriptors;
+       int                     result = -EINVAL;
+       struct usb_endpoint_descriptor *ep;
+       struct usb_configuration *c = NULL;
+       int                     addr;
+       int                     tmp;
+       struct usb_function     *f;
+
+       if (cdev->config)
+               reset_config(cdev);
+
+       if (number) {
+               list_for_each_entry(c, &cdev->configs, list) {
+                       if (c->bConfigurationValue == number) {
+                               result = 0;
+                               break;
+                       }
+               }
+               if (result < 0)
+                       goto done;
+       } else
+               result = 0;
+
+       debug("%s: %s speed config #%d: %s\n", __func__,
+            ({ char *speed;
+                    switch (gadget->speed) {
+                    case USB_SPEED_LOW:
+                            speed = "low";
+                            break;
+                    case USB_SPEED_FULL:
+                            speed = "full";
+                            break;
+                    case USB_SPEED_HIGH:
+                            speed = "high";
+                            break;
+                    default:
+                            speed = "?";
+                            break;
+                    };
+                    speed;
+            }), number, c ? c->label : "unconfigured");
+
+       if (!c)
+               goto done;
+
+       cdev->config = c;
+
+       /* Initialize all interfaces by setting them to altsetting zero. */
+       for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
+               f = c->interface[tmp];
+               if (!f)
+                       break;
+
+               /*
+                * Record which endpoints are used by the function. This is used
+                * to dispatch control requests targeted at that endpoint to the
+                * function's setup callback instead of the current
+                * configuration's setup callback.
+                */
+               if (gadget->speed == USB_SPEED_HIGH)
+                       descriptors = f->hs_descriptors;
+               else
+                       descriptors = f->descriptors;
+
+               for (; *descriptors; ++descriptors) {
+                       if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
+                               continue;
+
+                       ep = (struct usb_endpoint_descriptor *)*descriptors;
+                       addr = ((ep->bEndpointAddress & 0x80) >> 3)
+                            |  (ep->bEndpointAddress & 0x0f);
+                       __set_bit(addr, f->endpoints);
+               }
+
+               result = f->set_alt(f, tmp, 0);
+               if (result < 0) {
+                       debug("interface %d (%s/%p) alt 0 --> %d\n",
+                                       tmp, f->name, f, result);
+
+                       reset_config(cdev);
+                       goto done;
+               }
+       }
+
+       /* when we return, be sure our power usage is valid */
+       power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
+done:
+       usb_gadget_vbus_draw(gadget, power);
+       return result;
+}
+
+/**
+ * usb_add_config() - add a configuration to a device.
+ * @cdev: wraps the USB gadget
+ * @config: the configuration, with bConfigurationValue assigned
+ * Context: single threaded during gadget setup
+ *
+ * One of the main tasks of a composite driver's bind() routine is to
+ * add each of the configurations it supports, using this routine.
+ *
+ * This function returns the value of the configuration's bind(), which
+ * is zero for success else a negative errno value.  Binding configurations
+ * assigns global resources including string IDs, and per-configuration
+ * resources such as interface IDs and endpoints.
+ */
+int usb_add_config(struct usb_composite_dev *cdev,
+               struct usb_configuration *config)
+{
+       int                             status = -EINVAL;
+       struct usb_configuration        *c;
+       struct usb_function             *f;
+       unsigned int                    i;
+
+       debug("%s: adding config #%u '%s'/%p\n", __func__,
+                       config->bConfigurationValue,
+                       config->label, config);
+
+       if (!config->bConfigurationValue || !config->bind)
+               goto done;
+
+       /* Prevent duplicate configuration identifiers */
+       list_for_each_entry(c, &cdev->configs, list) {
+               if (c->bConfigurationValue == config->bConfigurationValue) {
+                       status = -EBUSY;
+                       goto done;
+               }
+       }
+
+       config->cdev = cdev;
+       list_add_tail(&config->list, &cdev->configs);
+
+       INIT_LIST_HEAD(&config->functions);
+       config->next_interface_id = 0;
+
+       status = config->bind(config);
+       if (status < 0) {
+               list_del(&config->list);
+               config->cdev = NULL;
+       } else {
+               debug("cfg %d/%p speeds:%s%s\n",
+                       config->bConfigurationValue, config,
+                       config->highspeed ? " high" : "",
+                       config->fullspeed
+                               ? (gadget_is_dualspeed(cdev->gadget)
+                                       ? " full"
+                                       : " full/low")
+                               : "");
+
+               for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
+                       f = config->interface[i];
+                       if (!f)
+                               continue;
+                       debug("%s: interface %d = %s/%p\n",
+                             __func__, i, f->name, f);
+               }
+       }
+
+       usb_ep_autoconfig_reset(cdev->gadget);
+
+done:
+       if (status)
+               debug("added config '%s'/%u --> %d\n", config->label,
+                               config->bConfigurationValue, status);
+       return status;
+}
+
+/*
+ * We support strings in multiple languages ... string descriptor zero
+ * says which languages are supported. The typical case will be that
+ * only one language (probably English) is used, with I18N handled on
+ * the host side.
+ */
+
+static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
+{
+       const struct usb_gadget_strings *s;
+       u16                             language;
+       __le16                          *tmp;
+
+       while (*sp) {
+               s = *sp;
+               language = cpu_to_le16(s->language);
+               for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
+                       if (*tmp == language)
+                               goto repeat;
+               }
+               *tmp++ = language;
+repeat:
+               sp++;
+       }
+}
+
+static int lookup_string(
+       struct usb_gadget_strings       **sp,
+       void                            *buf,
+       u16                             language,
+       int                             id
+)
+{
+       int                             value;
+       struct usb_gadget_strings       *s;
+
+       while (*sp) {
+               s = *sp++;
+               if (s->language != language)
+                       continue;
+               value = usb_gadget_get_string(s, id, buf);
+               if (value > 0)
+                       return value;
+       }
+       return -EINVAL;
+}
+
+static int get_string(struct usb_composite_dev *cdev,
+               void *buf, u16 language, int id)
+{
+       struct usb_string_descriptor    *s = buf;
+       struct usb_gadget_strings       **sp;
+       int                             len;
+       struct usb_configuration        *c;
+       struct usb_function             *f;
+
+       /*
+        * Yes, not only is USB's I18N support probably more than most
+        * folk will ever care about ... also, it's all supported here.
+        * (Except for UTF8 support for Unicode's "Astral Planes".)
+        */
+
+       /* 0 == report all available language codes */
+       if (id == 0) {
+               memset(s, 0, 256);
+               s->bDescriptorType = USB_DT_STRING;
+
+               sp = composite->strings;
+               if (sp)
+                       collect_langs(sp, s->wData);
+
+               list_for_each_entry(c, &cdev->configs, list) {
+                       sp = c->strings;
+                       if (sp)
+                               collect_langs(sp, s->wData);
+
+                       list_for_each_entry(f, &c->functions, list) {
+                               sp = f->strings;
+                               if (sp)
+                                       collect_langs(sp, s->wData);
+                       }
+               }
+
+               for (len = 0; len <= 126 && s->wData[len]; len++)
+                       continue;
+               if (!len)
+                       return -EINVAL;
+
+               s->bLength = 2 * (len + 1);
+               return s->bLength;
+       }
+
+       /*
+        * Otherwise, look up and return a specified string.  String IDs
+        * are device-scoped, so we look up each string table we're told
+        * about.  These lookups are infrequent; simpler-is-better here.
+        */
+       if (composite->strings) {
+               len = lookup_string(composite->strings, buf, language, id);
+               if (len > 0)
+                       return len;
+       }
+       list_for_each_entry(c, &cdev->configs, list) {
+               if (c->strings) {
+                       len = lookup_string(c->strings, buf, language, id);
+                       if (len > 0)
+                               return len;
+               }
+               list_for_each_entry(f, &c->functions, list) {
+                       if (!f->strings)
+                               continue;
+                       len = lookup_string(f->strings, buf, language, id);
+                       if (len > 0)
+                               return len;
+               }
+       }
+       return -EINVAL;
+}
+
+/**
+ * usb_string_id() - allocate an unused string ID
+ * @cdev: the device whose string descriptor IDs are being allocated
+ * Context: single threaded during gadget setup
+ *
+ * @usb_string_id() is called from bind() callbacks to allocate
+ * string IDs. Drivers for functions, configurations, or gadgets will
+ * then store that ID in the appropriate descriptors and string table.
+ *
+ * All string identifier should be allocated using this,
+ * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
+ * that for example different functions don't wrongly assign different
+ * meanings to the same identifier.
+ */
+int usb_string_id(struct usb_composite_dev *cdev)
+{
+       if (cdev->next_string_id < 254) {
+               /*
+                * string id 0 is reserved by USB spec for list of
+                * supported languages
+                * 255 reserved as well? -- mina86
+                */
+               cdev->next_string_id++;
+               return cdev->next_string_id;
+       }
+       return -ENODEV;
+}
+
+/**
+ * usb_string_ids() - allocate unused string IDs in batch
+ * @cdev: the device whose string descriptor IDs are being allocated
+ * @str: an array of usb_string objects to assign numbers to
+ * Context: single threaded during gadget setup
+ *
+ * @usb_string_ids() is called from bind() callbacks to allocate
+ * string IDs. Drivers for functions, configurations, or gadgets will
+ * then copy IDs from the string table to the appropriate descriptors
+ * and string table for other languages.
+ *
+ * All string identifier should be allocated using this,
+ * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
+ * example different functions don't wrongly assign different meanings
+ * to the same identifier.
+ */
+int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
+{
+       u8 next = cdev->next_string_id;
+
+       for (; str->s; ++str) {
+               if (next >= 254)
+                       return -ENODEV;
+               str->id = ++next;
+       }
+
+       cdev->next_string_id = next;
+
+       return 0;
+}
+
+/**
+ * usb_string_ids_n() - allocate unused string IDs in batch
+ * @c: the device whose string descriptor IDs are being allocated
+ * @n: number of string IDs to allocate
+ * Context: single threaded during gadget setup
+ *
+ * Returns the first requested ID.  This ID and next @n-1 IDs are now
+ * valid IDs.  At least provided that @n is non-zero because if it
+ * is, returns last requested ID which is now very useful information.
+ *
+ * @usb_string_ids_n() is called from bind() callbacks to allocate
+ * string IDs. Drivers for functions, configurations, or gadgets will
+ * then store that ID in the appropriate descriptors and string table.
+ *
+ * All string identifier should be allocated using this,
+ * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
+ * example different functions don't wrongly assign different meanings
+ * to the same identifier.
+ */
+int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
+{
+       u8 next = c->next_string_id;
+
+       if (n > 254 || next + n > 254)
+               return -ENODEV;
+
+       c->next_string_id += n;
+       return next + 1;
+}
+
+static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       if (req->status || req->actual != req->length)
+               debug("%s: setup complete --> %d, %d/%d\n", __func__,
+                               req->status, req->actual, req->length);
+}
+
+/*
+ * The setup() callback implements all the ep0 functionality that's
+ * not handled lower down, in hardware or the hardware driver(like
+ * device and endpoint feature flags, and their status).  It's all
+ * housekeeping for the gadget function we're implementing.  Most of
+ * the work is in config and function specific setup.
+ */
+static int
+composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
+{
+       u16                             w_length = le16_to_cpu(ctrl->wLength);
+       u16                             w_index = le16_to_cpu(ctrl->wIndex);
+       u16                             w_value = le16_to_cpu(ctrl->wValue);
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+       u8                              intf = w_index & 0xFF;
+       int                             value = -EOPNOTSUPP;
+       struct usb_request              *req = cdev->req;
+       struct usb_function             *f = NULL;
+       int                             standard;
+       u8                              endp;
+       struct usb_configuration        *c;
+
+       /*
+        * partial re-init of the response message; the function or the
+        * gadget might need to intercept e.g. a control-OUT completion
+        * when we delegate to it.
+        */
+       req->zero = 0;
+       req->complete = composite_setup_complete;
+       req->length = USB_BUFSIZ;
+       gadget->ep0->driver_data = cdev;
+       standard = (ctrl->bRequestType & USB_TYPE_MASK)
+                                               == USB_TYPE_STANDARD;
+       if (!standard)
+               goto unknown;
+
+       switch (ctrl->bRequest) {
+
+       /* we handle all standard USB descriptors */
+       case USB_REQ_GET_DESCRIPTOR:
+               if (ctrl->bRequestType != USB_DIR_IN)
+                       goto unknown;
+               switch (w_value >> 8) {
+
+               case USB_DT_DEVICE:
+                       cdev->desc.bNumConfigurations =
+                               count_configs(cdev, USB_DT_DEVICE);
+                       value = min(w_length, (u16) sizeof cdev->desc);
+                       memcpy(req->buf, &cdev->desc, value);
+                       break;
+               case USB_DT_DEVICE_QUALIFIER:
+                       if (!gadget_is_dualspeed(gadget))
+                               break;
+                       device_qual(cdev);
+                       value = min(w_length,
+                               sizeof(struct usb_qualifier_descriptor));
+                       break;
+               case USB_DT_OTHER_SPEED_CONFIG:
+                       if (!gadget_is_dualspeed(gadget))
+                               break;
+
+               case USB_DT_CONFIG:
+                       value = config_desc(cdev, w_value);
+                       if (value >= 0)
+                               value = min(w_length, (u16) value);
+                       break;
+               case USB_DT_STRING:
+                       value = get_string(cdev, req->buf,
+                                       w_index, w_value & 0xff);
+                       if (value >= 0)
+                               value = min(w_length, (u16) value);
+                       break;
+               default:
+                       goto unknown;
+               }
+               break;
+
+       /* any number of configs can work */
+       case USB_REQ_SET_CONFIGURATION:
+               if (ctrl->bRequestType != 0)
+                       goto unknown;
+               if (gadget_is_otg(gadget)) {
+                       if (gadget->a_hnp_support)
+                               debug("HNP available\n");
+                       else if (gadget->a_alt_hnp_support)
+                               debug("HNP on another port\n");
+                       else
+                               debug("HNP inactive\n");
+               }
+
+               value = set_config(cdev, ctrl, w_value);
+               break;
+       case USB_REQ_GET_CONFIGURATION:
+               if (ctrl->bRequestType != USB_DIR_IN)
+                       goto unknown;
+               if (cdev->config)
+                       *(u8 *)req->buf = cdev->config->bConfigurationValue;
+               else
+                       *(u8 *)req->buf = 0;
+               value = min(w_length, (u16) 1);
+               break;
+
+       /*
+        * function drivers must handle get/set altsetting; if there's
+        * no get() method, we know only altsetting zero works.
+        */
+       case USB_REQ_SET_INTERFACE:
+               if (ctrl->bRequestType != USB_RECIP_INTERFACE)
+                       goto unknown;
+               if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
+                       break;
+               f = cdev->config->interface[intf];
+               if (!f)
+                       break;
+               if (w_value && !f->set_alt)
+                       break;
+               value = f->set_alt(f, w_index, w_value);
+               break;
+       case USB_REQ_GET_INTERFACE:
+               if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
+                       goto unknown;
+               if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
+                       break;
+               f = cdev->config->interface[intf];
+               if (!f)
+                       break;
+               /* lots of interfaces only need altsetting zero... */
+               value = f->get_alt ? f->get_alt(f, w_index) : 0;
+               if (value < 0)
+                       break;
+               *((u8 *)req->buf) = value;
+               value = min(w_length, (u16) 1);
+               break;
+       default:
+unknown:
+               debug("non-core control req%02x.%02x v%04x i%04x l%d\n",
+                       ctrl->bRequestType, ctrl->bRequest,
+                       w_value, w_index, w_length);
+
+               /*
+                * functions always handle their interfaces and endpoints...
+                * punt other recipients (other, WUSB, ...) to the current
+                * configuration code.
+                */
+               switch (ctrl->bRequestType & USB_RECIP_MASK) {
+               case USB_RECIP_INTERFACE:
+                       f = cdev->config->interface[intf];
+                       break;
+
+               case USB_RECIP_ENDPOINT:
+                       endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
+                       list_for_each_entry(f, &cdev->config->functions, list) {
+                               if (test_bit(endp, f->endpoints))
+                                       break;
+                       }
+                       if (&f->list == &cdev->config->functions)
+                               f = NULL;
+                       break;
+               /*
+                * dfu-util (version 0.5) sets bmRequestType.Receipent = Device
+                * for non-standard request (w_value = 0x21,
+                * bRequest = GET_DESCRIPTOR in this case).
+                * When only one interface is registered (as it is done now),
+                * then this request shall be handled as it was requested for
+                * interface.
+                *
+                * In the below code it is checked if only one interface is
+                * present and proper function for it is extracted. Due to that
+                * function's setup (f->setup) is called to handle this
+                * special non-standard request.
+                */
+               case USB_RECIP_DEVICE:
+                       debug("cdev->config->next_interface_id: %d intf: %d\n",
+                              cdev->config->next_interface_id, intf);
+                       if (cdev->config->next_interface_id == 1)
+                               f = cdev->config->interface[intf];
+                       break;
+               }
+
+               if (f && f->setup)
+                       value = f->setup(f, ctrl);
+               else {
+                       c = cdev->config;
+                       if (c && c->setup)
+                               value = c->setup(c, ctrl);
+               }
+
+               goto done;
+       }
+
+       /* respond with data transfer before status phase? */
+       if (value >= 0) {
+               req->length = value;
+               req->zero = value < w_length;
+               value = usb_ep_queue(gadget->ep0, req, GFP_KERNEL);
+               if (value < 0) {
+                       debug("ep_queue --> %d\n", value);
+                       req->status = 0;
+                       composite_setup_complete(gadget->ep0, req);
+               }
+       }
+
+done:
+       /* device either stalls (value < 0) or reports success */
+       return value;
+}
+
+static void composite_disconnect(struct usb_gadget *gadget)
+{
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+
+       if (cdev->config)
+               reset_config(cdev);
+       if (composite->disconnect)
+               composite->disconnect(cdev);
+}
+
+static void composite_unbind(struct usb_gadget *gadget)
+{
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+       struct usb_configuration        *c;
+       struct usb_function             *f;
+
+       /*
+        * composite_disconnect() must already have been called
+        * by the underlying peripheral controller driver!
+        * so there's no i/o concurrency that could affect the
+        * state protected by cdev->lock.
+        */
+       BUG_ON(cdev->config);
+
+       while (!list_empty(&cdev->configs)) {
+               c = list_first_entry(&cdev->configs,
+                               struct usb_configuration, list);
+               while (!list_empty(&c->functions)) {
+                       f = list_first_entry(&c->functions,
+                                       struct usb_function, list);
+                       list_del(&f->list);
+                       if (f->unbind) {
+                               debug("unbind function '%s'/%p\n",
+                                               f->name, f);
+                               f->unbind(c, f);
+                       }
+               }
+               list_del(&c->list);
+               if (c->unbind) {
+                       debug("unbind config '%s'/%p\n", c->label, c);
+                       c->unbind(c);
+               }
+       }
+       if (composite->unbind)
+               composite->unbind(cdev);
+
+       if (cdev->req) {
+               kfree(cdev->req->buf);
+               usb_ep_free_request(gadget->ep0, cdev->req);
+       }
+       kfree(cdev);
+       set_gadget_data(gadget, NULL);
+
+       composite = NULL;
+}
+
+static int composite_bind(struct usb_gadget *gadget)
+{
+       int                             status = -ENOMEM;
+       struct usb_composite_dev        *cdev;
+
+       cdev = calloc(sizeof *cdev, 1);
+       if (!cdev)
+               return status;
+
+       cdev->gadget = gadget;
+       set_gadget_data(gadget, cdev);
+       INIT_LIST_HEAD(&cdev->configs);
+
+       /* preallocate control response and buffer */
+       cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+       if (!cdev->req)
+               goto fail;
+       cdev->req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, USB_BUFSIZ);
+       if (!cdev->req->buf)
+               goto fail;
+       cdev->req->complete = composite_setup_complete;
+       gadget->ep0->driver_data = cdev;
+
+       cdev->bufsiz = USB_BUFSIZ;
+       cdev->driver = composite;
+
+       usb_gadget_set_selfpowered(gadget);
+       usb_ep_autoconfig_reset(cdev->gadget);
+
+       status = composite->bind(cdev);
+       if (status < 0)
+               goto fail;
+
+       memcpy(&cdev->desc, composite->dev,
+              sizeof(struct usb_device_descriptor));
+       cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
+
+       debug("%s: ready\n", composite->name);
+       return 0;
+
+fail:
+       composite_unbind(gadget);
+       return status;
+}
+
+static void
+composite_suspend(struct usb_gadget *gadget)
+{
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+       struct usb_function             *f;
+
+       debug("%s: suspend\n", __func__);
+       if (cdev->config) {
+               list_for_each_entry(f, &cdev->config->functions, list) {
+                       if (f->suspend)
+                               f->suspend(f);
+               }
+       }
+       if (composite->suspend)
+               composite->suspend(cdev);
+
+       cdev->suspended = 1;
+}
+
+static void
+composite_resume(struct usb_gadget *gadget)
+{
+       struct usb_composite_dev        *cdev = get_gadget_data(gadget);
+       struct usb_function             *f;
+
+       debug("%s: resume\n", __func__);
+       if (composite->resume)
+               composite->resume(cdev);
+       if (cdev->config) {
+               list_for_each_entry(f, &cdev->config->functions, list) {
+                       if (f->resume)
+                               f->resume(f);
+               }
+       }
+
+       cdev->suspended = 0;
+}
+
+static struct usb_gadget_driver composite_driver = {
+       .speed          = USB_SPEED_HIGH,
+
+       .bind           = composite_bind,
+       .unbind         = composite_unbind,
+
+       .setup          = composite_setup,
+       .disconnect     = composite_disconnect,
+
+       .suspend        = composite_suspend,
+       .resume         = composite_resume,
+};
+
+/**
+ * usb_composite_register() - register a composite driver
+ * @driver: the driver to register
+ * Context: single threaded during gadget setup
+ *
+ * This function is used to register drivers using the composite driver
+ * framework.  The return value is zero, or a negative errno value.
+ * Those values normally come from the driver's @bind method, which does
+ * all the work of setting up the driver to match the hardware.
+ *
+ * On successful return, the gadget is ready to respond to requests from
+ * the host, unless one of its components invokes usb_gadget_disconnect()
+ * while it was binding.  That would usually be done in order to wait for
+ * some userspace participation.
+ */
+int usb_composite_register(struct usb_composite_driver *driver)
+{
+       if (!driver || !driver->dev || !driver->bind || composite)
+               return -EINVAL;
+
+       if (!driver->name)
+               driver->name = "composite";
+       composite = driver;
+
+       return usb_gadget_register_driver(&composite_driver);
+}
+
+/**
+ * usb_composite_unregister() - unregister a composite driver
+ * @driver: the driver to unregister
+ *
+ * This function is used to unregister drivers using the composite
+ * driver framework.
+ */
+void usb_composite_unregister(struct usb_composite_driver *driver)
+{
+       if (composite != driver)
+               return;
+       usb_gadget_unregister_driver(&composite_driver);
+       composite = NULL;
+}