drivers/usb/gadget/f_uvc.c

   1 /*
   2  *      uvc_gadget.c  --  USB Video Class Gadget driver
   3  *
   4  *      Copyright (C) 2009-2010
   5  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   6  *
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation; either version 2 of the License, or
  10  *      (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/device.h>
  16 #include <linux/errno.h>
  17 #include <linux/fs.h>
  18 #include <linux/list.h>
  19 #include <linux/mutex.h>
  20 #include <linux/usb/ch9.h>
  21 #include <linux/usb/gadget.h>
  22 #include <linux/usb/video.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/wait.h>
  25
  26 #include <media/v4l2-dev.h>
  27 #include <media/v4l2-event.h>
  28
  29 #include "uvc.h"
  30
  31 unsigned int uvc_gadget_trace_param;
  32
  33 /* --------------------------------------------------------------------------
  34  * Function descriptors
  35  */
  36
  37 /* string IDs are assigned dynamically */
  38
  39 #define UVC_STRING_ASSOCIATION_IDX              0
  40 #define UVC_STRING_CONTROL_IDX                  1
  41 #define UVC_STRING_STREAMING_IDX                2
  42
  43 static struct usb_string uvc_en_us_strings[] = {
  44         [UVC_STRING_ASSOCIATION_IDX].s = "UVC Camera",
  45         [UVC_STRING_CONTROL_IDX].s = "Video Control",
  46         [UVC_STRING_STREAMING_IDX].s = "Video Streaming",
  47         {  }
  48 };
  49
  50 static struct usb_gadget_strings uvc_stringtab = {
  51         .language = 0x0409,     /* en-us */
  52         .strings = uvc_en_us_strings,
  53 };
  54
  55 static struct usb_gadget_strings *uvc_function_strings[] = {
  56         &uvc_stringtab,
  57         NULL,
  58 };
  59
  60 #define UVC_INTF_VIDEO_CONTROL                  0
  61 #define UVC_INTF_VIDEO_STREAMING                1
  62
  63 static struct usb_interface_assoc_descriptor uvc_iad __initdata = {
  64         .bLength                = sizeof(uvc_iad),
  65         .bDescriptorType        = USB_DT_INTERFACE_ASSOCIATION,
  66         .bFirstInterface        = 0,
  67         .bInterfaceCount        = 2,
  68         .bFunctionClass         = USB_CLASS_VIDEO,
  69         .bFunctionSubClass      = UVC_SC_VIDEO_INTERFACE_COLLECTION,
  70         .bFunctionProtocol      = 0x00,
  71         .iFunction              = 0,
  72 };
  73
  74 static struct usb_interface_descriptor uvc_control_intf __initdata = {
  75         .bLength                = USB_DT_INTERFACE_SIZE,
  76         .bDescriptorType        = USB_DT_INTERFACE,
  77         .bInterfaceNumber       = UVC_INTF_VIDEO_CONTROL,
  78         .bAlternateSetting      = 0,
  79         .bNumEndpoints          = 1,
  80         .bInterfaceClass        = USB_CLASS_VIDEO,
  81         .bInterfaceSubClass     = UVC_SC_VIDEOCONTROL,
  82         .bInterfaceProtocol     = 0x00,
  83         .iInterface             = 0,
  84 };
  85
  86 static struct usb_endpoint_descriptor uvc_control_ep __initdata = {
  87         .bLength                = USB_DT_ENDPOINT_SIZE,
  88         .bDescriptorType        = USB_DT_ENDPOINT,
  89         .bEndpointAddress       = USB_DIR_IN,
  90         .bmAttributes           = USB_ENDPOINT_XFER_INT,
  91         .wMaxPacketSize         = cpu_to_le16(16),
  92         .bInterval              = 8,
  93 };
  94
  95 static struct uvc_control_endpoint_descriptor uvc_control_cs_ep __initdata = {
  96         .bLength                = UVC_DT_CONTROL_ENDPOINT_SIZE,
  97         .bDescriptorType        = USB_DT_CS_ENDPOINT,
  98         .bDescriptorSubType     = UVC_EP_INTERRUPT,
  99         .wMaxTransferSize       = cpu_to_le16(16),
 100 };
 101
 102 static struct usb_interface_descriptor uvc_streaming_intf_alt0 __initdata = {
 103         .bLength                = USB_DT_INTERFACE_SIZE,
 104         .bDescriptorType        = USB_DT_INTERFACE,
 105         .bInterfaceNumber       = UVC_INTF_VIDEO_STREAMING,
 106         .bAlternateSetting      = 0,
 107         .bNumEndpoints          = 0,
 108         .bInterfaceClass        = USB_CLASS_VIDEO,
 109         .bInterfaceSubClass     = UVC_SC_VIDEOSTREAMING,
 110         .bInterfaceProtocol     = 0x00,
 111         .iInterface             = 0,
 112 };
 113
 114 static struct usb_interface_descriptor uvc_streaming_intf_alt1 __initdata = {
 115         .bLength                = USB_DT_INTERFACE_SIZE,
 116         .bDescriptorType        = USB_DT_INTERFACE,
 117         .bInterfaceNumber       = UVC_INTF_VIDEO_STREAMING,
 118         .bAlternateSetting      = 1,
 119         .bNumEndpoints          = 1,
 120         .bInterfaceClass        = USB_CLASS_VIDEO,
 121         .bInterfaceSubClass     = UVC_SC_VIDEOSTREAMING,
 122         .bInterfaceProtocol     = 0x00,
 123         .iInterface             = 0,
 124 };
 125
 126 static struct usb_endpoint_descriptor uvc_streaming_ep = {
 127         .bLength                = USB_DT_ENDPOINT_SIZE,
 128         .bDescriptorType        = USB_DT_ENDPOINT,
 129         .bEndpointAddress       = USB_DIR_IN,
 130         .bmAttributes           = USB_ENDPOINT_XFER_ISOC,
 131         .wMaxPacketSize         = cpu_to_le16(512),
 132         .bInterval              = 1,
 133 };
 134
 135 static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
 136         (struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
 137         (struct usb_descriptor_header *) &uvc_streaming_ep,
 138         NULL,
 139 };
 140
 141 static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
 142         (struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
 143         (struct usb_descriptor_header *) &uvc_streaming_ep,
 144         NULL,
 145 };
 146
 147 /* --------------------------------------------------------------------------
 148  * Control requests
 149  */
 150
 151 static void
 152 uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 153 {
 154         struct uvc_device *uvc = req->context;
 155         struct v4l2_event v4l2_event;
 156         struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 157
 158         if (uvc->event_setup_out) {
 159                 uvc->event_setup_out = 0;
 160
 161                 memset(&v4l2_event, 0, sizeof(v4l2_event));
 162                 v4l2_event.type = UVC_EVENT_DATA;
 163                 uvc_event->data.length = req->actual;
 164                 memcpy(&uvc_event->data.data, req->buf, req->actual);
 165                 v4l2_event_queue(uvc->vdev, &v4l2_event);
 166         }
 167 }
 168
 169 static int
 170 uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 171 {
 172         struct uvc_device *uvc = to_uvc(f);
 173         struct v4l2_event v4l2_event;
 174         struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 175
 176         /* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
 177          *      ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
 178          *      le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
 179          */
 180
 181         if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
 182                 INFO(f->config->cdev, "invalid request type\n");
 183                 return -EINVAL;
 184         }
 185
 186         /* Stall too big requests. */
 187         if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
 188                 return -EINVAL;
 189
 190         memset(&v4l2_event, 0, sizeof(v4l2_event));
 191         v4l2_event.type = UVC_EVENT_SETUP;
 192         memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
 193         v4l2_event_queue(uvc->vdev, &v4l2_event);
 194
 195         return 0;
 196 }
 197
 198 static int
 199 uvc_function_get_alt(struct usb_function *f, unsigned interface)
 200 {
 201         struct uvc_device *uvc = to_uvc(f);
 202
 203         INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);
 204
 205         if (interface == uvc->control_intf)
 206                 return 0;
 207         else if (interface != uvc->streaming_intf)
 208                 return -EINVAL;
 209         else
 210                 return uvc->state == UVC_STATE_STREAMING ? 1 : 0;
 211 }
 212
 213 static int
 214 uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 215 {
 216         struct uvc_device *uvc = to_uvc(f);
 217         struct v4l2_event v4l2_event;
 218         struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 219
 220         INFO(f->config->cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);
 221
 222         if (interface == uvc->control_intf) {
 223                 if (alt)
 224                         return -EINVAL;
 225
 226                 if (uvc->state == UVC_STATE_DISCONNECTED) {
 227                         memset(&v4l2_event, 0, sizeof(v4l2_event));
 228                         v4l2_event.type = UVC_EVENT_CONNECT;
 229                         uvc_event->speed = f->config->cdev->gadget->speed;
 230                         v4l2_event_queue(uvc->vdev, &v4l2_event);
 231
 232                         uvc->state = UVC_STATE_CONNECTED;
 233                 }
 234
 235                 return 0;
 236         }
 237
 238         if (interface != uvc->streaming_intf)
 239                 return -EINVAL;
 240
 241         /* TODO
 242         if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
 243                 return alt ? -EINVAL : 0;
 244         */
 245
 246         switch (alt) {
 247         case 0:
 248                 if (uvc->state != UVC_STATE_STREAMING)
 249                         return 0;
 250
 251                 if (uvc->video.ep)
 252                         usb_ep_disable(uvc->video.ep);
 253
 254                 memset(&v4l2_event, 0, sizeof(v4l2_event));
 255                 v4l2_event.type = UVC_EVENT_STREAMOFF;
 256                 v4l2_event_queue(uvc->vdev, &v4l2_event);
 257
 258                 uvc->state = UVC_STATE_CONNECTED;
 259                 break;
 260
 261         case 1:
 262                 if (uvc->state != UVC_STATE_CONNECTED)
 263                         return 0;
 264
 265                 if (uvc->video.ep) {
 266                         uvc->video.ep->desc = &uvc_streaming_ep;
 267                         usb_ep_enable(uvc->video.ep);
 268                 }
 269
 270                 memset(&v4l2_event, 0, sizeof(v4l2_event));
 271                 v4l2_event.type = UVC_EVENT_STREAMON;
 272                 v4l2_event_queue(uvc->vdev, &v4l2_event);
 273
 274                 uvc->state = UVC_STATE_STREAMING;
 275                 break;
 276
 277         default:
 278                 return -EINVAL;
 279         }
 280
 281         return 0;
 282 }
 283
 284 static void
 285 uvc_function_disable(struct usb_function *f)
 286 {
 287         struct uvc_device *uvc = to_uvc(f);
 288         struct v4l2_event v4l2_event;
 289
 290         INFO(f->config->cdev, "uvc_function_disable\n");
 291
 292         memset(&v4l2_event, 0, sizeof(v4l2_event));
 293         v4l2_event.type = UVC_EVENT_DISCONNECT;
 294         v4l2_event_queue(uvc->vdev, &v4l2_event);
 295
 296         uvc->state = UVC_STATE_DISCONNECTED;
 297 }
 298
 299 /* --------------------------------------------------------------------------
 300  * Connection / disconnection
 301  */
 302
 303 void
 304 uvc_function_connect(struct uvc_device *uvc)
 305 {
 306         struct usb_composite_dev *cdev = uvc->func.config->cdev;
 307         int ret;
 308
 309         if ((ret = usb_function_activate(&uvc->func)) < 0)
 310                 INFO(cdev, "UVC connect failed with %d\n", ret);
 311 }
 312
 313 void
 314 uvc_function_disconnect(struct uvc_device *uvc)
 315 {
 316         struct usb_composite_dev *cdev = uvc->func.config->cdev;
 317         int ret;
 318
 319         if ((ret = usb_function_deactivate(&uvc->func)) < 0)
 320                 INFO(cdev, "UVC disconnect failed with %d\n", ret);
 321 }
 322
 323 /* --------------------------------------------------------------------------
 324  * USB probe and disconnect
 325  */
 326
 327 static int
 328 uvc_register_video(struct uvc_device *uvc)
 329 {
 330         struct usb_composite_dev *cdev = uvc->func.config->cdev;
 331         struct video_device *video;
 332
 333         /* TODO reference counting. */
 334         video = video_device_alloc();
 335         if (video == NULL)
 336                 return -ENOMEM;
 337
 338         video->parent = &cdev->gadget->dev;
 339         video->minor = -1;
 340         video->fops = &uvc_v4l2_fops;
 341         video->release = video_device_release;
 342         strncpy(video->name, cdev->gadget->name, sizeof(video->name));
 343
 344         uvc->vdev = video;
 345         video_set_drvdata(video, uvc);
 346
 347         return video_register_device(video, VFL_TYPE_GRABBER, -1);
 348 }
 349
 350 #define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
 351         do { \
 352                 memcpy(mem, desc, (desc)->bLength); \
 353                 *(dst)++ = mem; \
 354                 mem += (desc)->bLength; \
 355         } while (0);
 356
 357 #define UVC_COPY_DESCRIPTORS(mem, dst, src) \
 358         do { \
 359                 const struct usb_descriptor_header * const *__src; \
 360                 for (__src = src; *__src; ++__src) { \
 361                         memcpy(mem, *__src, (*__src)->bLength); \
 362                         *dst++ = mem; \
 363                         mem += (*__src)->bLength; \
 364                 } \
 365         } while (0)
 366
 367 static struct usb_descriptor_header ** __init
 368 uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
 369 {
 370         struct uvc_input_header_descriptor *uvc_streaming_header;
 371         struct uvc_header_descriptor *uvc_control_header;
 372         const struct uvc_descriptor_header * const *uvc_streaming_cls;
 373         const struct usb_descriptor_header * const *uvc_streaming_std;
 374         const struct usb_descriptor_header * const *src;
 375         struct usb_descriptor_header **dst;
 376         struct usb_descriptor_header **hdr;
 377         unsigned int control_size;
 378         unsigned int streaming_size;
 379         unsigned int n_desc;
 380         unsigned int bytes;
 381         void *mem;
 382
 383         uvc_streaming_cls = (speed == USB_SPEED_FULL)
 384                           ? uvc->desc.fs_streaming : uvc->desc.hs_streaming;
 385         uvc_streaming_std = (speed == USB_SPEED_FULL)
 386                           ? uvc_fs_streaming : uvc_hs_streaming;
 387
 388         /* Descriptors layout
 389          *
 390          * uvc_iad
 391          * uvc_control_intf
 392          * Class-specific UVC control descriptors
 393          * uvc_control_ep
 394          * uvc_control_cs_ep
 395          * uvc_streaming_intf_alt0
 396          * Class-specific UVC streaming descriptors
 397          * uvc_{fs|hs}_streaming
 398          */
 399
 400         /* Count descriptors and compute their size. */
 401         control_size = 0;
 402         streaming_size = 0;
 403         bytes = uvc_iad.bLength + uvc_control_intf.bLength
 404               + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
 405               + uvc_streaming_intf_alt0.bLength;
 406         n_desc = 5;
 407
 408         for (src = (const struct usb_descriptor_header**)uvc->desc.control; *src; ++src) {
 409                 control_size += (*src)->bLength;
 410                 bytes += (*src)->bLength;
 411                 n_desc++;
 412         }
 413         for (src = (const struct usb_descriptor_header**)uvc_streaming_cls; *src; ++src) {
 414                 streaming_size += (*src)->bLength;
 415                 bytes += (*src)->bLength;
 416                 n_desc++;
 417         }
 418         for (src = uvc_streaming_std; *src; ++src) {
 419                 bytes += (*src)->bLength;
 420                 n_desc++;
 421         }
 422
 423         mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
 424         if (mem == NULL)
 425                 return NULL;
 426
 427         hdr = mem;
 428         dst = mem;
 429         mem += (n_desc + 1) * sizeof(*src);
 430
 431         /* Copy the descriptors. */
 432         UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
 433         UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
 434
 435         uvc_control_header = mem;
 436         UVC_COPY_DESCRIPTORS(mem, dst,
 437                 (const struct usb_descriptor_header**)uvc->desc.control);
 438         uvc_control_header->wTotalLength = cpu_to_le16(control_size);
 439         uvc_control_header->bInCollection = 1;
 440         uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
 441
 442         UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
 443         UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
 444         UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
 445
 446         uvc_streaming_header = mem;
 447         UVC_COPY_DESCRIPTORS(mem, dst,
 448                 (const struct usb_descriptor_header**)uvc_streaming_cls);
 449         uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
 450         uvc_streaming_header->bEndpointAddress = uvc_streaming_ep.bEndpointAddress;
 451
 452         UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
 453
 454         *dst = NULL;
 455         return hdr;
 456 }
 457
 458 static void
 459 uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)
 460 {
 461         struct usb_composite_dev *cdev = c->cdev;
 462         struct uvc_device *uvc = to_uvc(f);
 463
 464         INFO(cdev, "uvc_function_unbind\n");
 465
 466         if (uvc->vdev) {
 467                 if (uvc->vdev->minor == -1)
 468                         video_device_release(uvc->vdev);
 469                 else
 470                         video_unregister_device(uvc->vdev);
 471                 uvc->vdev = NULL;
 472         }
 473
 474         if (uvc->control_ep)
 475                 uvc->control_ep->driver_data = NULL;
 476         if (uvc->video.ep)
 477                 uvc->video.ep->driver_data = NULL;
 478
 479         if (uvc->control_req) {
 480                 usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
 481                 kfree(uvc->control_buf);
 482         }
 483
 484         kfree(f->descriptors);
 485         kfree(f->hs_descriptors);
 486
 487         kfree(uvc);
 488 }
 489
 490 static int __init
 491 uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 492 {
 493         struct usb_composite_dev *cdev = c->cdev;
 494         struct uvc_device *uvc = to_uvc(f);
 495         struct usb_ep *ep;
 496         int ret = -EINVAL;
 497
 498         INFO(cdev, "uvc_function_bind\n");
 499
 500         /* Allocate endpoints. */
 501         ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
 502         if (!ep) {
 503                 INFO(cdev, "Unable to allocate control EP\n");
 504                 goto error;
 505         }
 506         uvc->control_ep = ep;
 507         ep->driver_data = uvc;
 508
 509         ep = usb_ep_autoconfig(cdev->gadget, &uvc_streaming_ep);
 510         if (!ep) {
 511                 INFO(cdev, "Unable to allocate streaming EP\n");
 512                 goto error;
 513         }
 514         uvc->video.ep = ep;
 515         ep->driver_data = uvc;
 516
 517         /* Allocate interface IDs. */
 518         if ((ret = usb_interface_id(c, f)) < 0)
 519                 goto error;
 520         uvc_iad.bFirstInterface = ret;
 521         uvc_control_intf.bInterfaceNumber = ret;
 522         uvc->control_intf = ret;
 523
 524         if ((ret = usb_interface_id(c, f)) < 0)
 525                 goto error;
 526         uvc_streaming_intf_alt0.bInterfaceNumber = ret;
 527         uvc_streaming_intf_alt1.bInterfaceNumber = ret;
 528         uvc->streaming_intf = ret;
 529
 530         /* Copy descriptors. */
 531         f->descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
 532         f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
 533
 534         /* Preallocate control endpoint request. */
 535         uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
 536         uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
 537         if (uvc->control_req == NULL || uvc->control_buf == NULL) {
 538                 ret = -ENOMEM;
 539                 goto error;
 540         }
 541
 542         uvc->control_req->buf = uvc->control_buf;
 543         uvc->control_req->complete = uvc_function_ep0_complete;
 544         uvc->control_req->context = uvc;
 545
 546         /* Avoid letting this gadget enumerate until the userspace server is
 547          * active.
 548          */
 549         if ((ret = usb_function_deactivate(f)) < 0)
 550                 goto error;
 551
 552         /* Initialise video. */
 553         ret = uvc_video_init(&uvc->video);
 554         if (ret < 0)
 555                 goto error;
 556
 557         /* Register a V4L2 device. */
 558         ret = uvc_register_video(uvc);
 559         if (ret < 0) {
 560                 printk(KERN_INFO "Unable to register video device\n");
 561                 goto error;
 562         }
 563
 564         return 0;
 565
 566 error:
 567         uvc_function_unbind(c, f);
 568         return ret;
 569 }
 570
 571 /* --------------------------------------------------------------------------
 572  * USB gadget function
 573  */
 574
 575 /**
 576  * uvc_bind_config - add a UVC function to a configuration
 577  * @c: the configuration to support the UVC instance
 578  * Context: single threaded during gadget setup
 579  *
 580  * Returns zero on success, else negative errno.
 581  *
 582  * Caller must have called @uvc_setup(). Caller is also responsible for
 583  * calling @uvc_cleanup() before module unload.
 584  */
 585 int __init
 586 uvc_bind_config(struct usb_configuration *c,
 587                 const struct uvc_descriptor_header * const *control,
 588                 const struct uvc_descriptor_header * const *fs_streaming,
 589                 const struct uvc_descriptor_header * const *hs_streaming)
 590 {
 591         struct uvc_device *uvc;
 592         int ret = 0;
 593
 594         /* TODO Check if the USB device controller supports the required
 595          * features.
 596          */
 597         if (!gadget_is_dualspeed(c->cdev->gadget))
 598                 return -EINVAL;
 599
 600         uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
 601         if (uvc == NULL)
 602                 return -ENOMEM;
 603
 604         uvc->state = UVC_STATE_DISCONNECTED;
 605
 606         /* Validate the descriptors. */
 607         if (control == NULL || control[0] == NULL ||
 608             control[0]->bDescriptorSubType != UVC_VC_HEADER)
 609                 goto error;
 610
 611         if (fs_streaming == NULL || fs_streaming[0] == NULL ||
 612             fs_streaming[0]->bDescriptorSubType != UVC_VS_INPUT_HEADER)
 613                 goto error;
 614
 615         if (hs_streaming == NULL || hs_streaming[0] == NULL ||
 616             hs_streaming[0]->bDescriptorSubType != UVC_VS_INPUT_HEADER)
 617                 goto error;
 618
 619         uvc->desc.control = control;
 620         uvc->desc.fs_streaming = fs_streaming;
 621         uvc->desc.hs_streaming = hs_streaming;
 622
 623         /* Allocate string descriptor numbers. */
 624         if ((ret = usb_string_id(c->cdev)) < 0)
 625                 goto error;
 626         uvc_en_us_strings[UVC_STRING_ASSOCIATION_IDX].id = ret;
 627         uvc_iad.iFunction = ret;
 628
 629         if ((ret = usb_string_id(c->cdev)) < 0)
 630                 goto error;
 631         uvc_en_us_strings[UVC_STRING_CONTROL_IDX].id = ret;
 632         uvc_control_intf.iInterface = ret;
 633
 634         if ((ret = usb_string_id(c->cdev)) < 0)
 635                 goto error;
 636         uvc_en_us_strings[UVC_STRING_STREAMING_IDX].id = ret;
 637         uvc_streaming_intf_alt0.iInterface = ret;
 638         uvc_streaming_intf_alt1.iInterface = ret;
 639
 640         /* Register the function. */
 641         uvc->func.name = "uvc";
 642         uvc->func.strings = uvc_function_strings;
 643         uvc->func.bind = uvc_function_bind;
 644         uvc->func.unbind = uvc_function_unbind;
 645         uvc->func.get_alt = uvc_function_get_alt;
 646         uvc->func.set_alt = uvc_function_set_alt;
 647         uvc->func.disable = uvc_function_disable;
 648         uvc->func.setup = uvc_function_setup;
 649
 650         ret = usb_add_function(c, &uvc->func);
 651         if (ret)
 652                 kfree(uvc);
 653
 654         return ret;
 655
 656 error:
 657         kfree(uvc);
 658         return ret;
 659 }
 660
 661 module_param_named(trace, uvc_gadget_trace_param, uint, S_IRUGO|S_IWUSR);
 662 MODULE_PARM_DESC(trace, "Trace level bitmask");
 663