drivers/usb/gadget/function/uvc_v4l2.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *      uvc_v4l2.c  --  USB Video Class Gadget driver
   4  *
   5  *      Copyright (C) 2009-2010
   6  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/list.h>
  13 #include <linux/usb/g_uvc.h>
  14 #include <linux/usb/uvc.h>
  15 #include <linux/videodev2.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/wait.h>
  18
  19 #include <media/v4l2-dev.h>
  20 #include <media/v4l2-event.h>
  21 #include <media/v4l2-ioctl.h>
  22
  23 #include "f_uvc.h"
  24 #include "uvc.h"
  25 #include "uvc_queue.h"
  26 #include "uvc_video.h"
  27 #include "uvc_v4l2.h"
  28 #include "uvc_configfs.h"
  29
  30 static const struct uvc_format_desc *to_uvc_format(struct uvcg_format *uformat)
  31 {
  32         char guid[16] = UVC_GUID_FORMAT_MJPEG;
  33         const struct uvc_format_desc *format;
  34         struct uvcg_uncompressed *unc;
  35
  36         if (uformat->type == UVCG_UNCOMPRESSED) {
  37                 unc = to_uvcg_uncompressed(&uformat->group.cg_item);
  38                 if (!unc)
  39                         return ERR_PTR(-EINVAL);
  40
  41                 memcpy(guid, unc->desc.guidFormat, sizeof(guid));
  42         }
  43
  44         format = uvc_format_by_guid(guid);
  45         if (!format)
  46                 return ERR_PTR(-EINVAL);
  47
  48         return format;
  49 }
  50
  51 static int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,
  52                               struct uvcg_frame *uframe)
  53 {
  54         struct uvcg_uncompressed *u;
  55
  56         if (uformat->type == UVCG_UNCOMPRESSED) {
  57                 u = to_uvcg_uncompressed(&uformat->group.cg_item);
  58                 if (!u)
  59                         return 0;
  60
  61                 return u->desc.bBitsPerPixel * uframe->frame.w_width / 8;
  62         }
  63
  64         return 0;
  65 }
  66
  67 static int uvc_get_frame_size(struct uvcg_format *uformat,
  68                        struct uvcg_frame *uframe)
  69 {
  70         unsigned int bpl = uvc_v4l2_get_bytesperline(uformat, uframe);
  71
  72         return bpl ? bpl * uframe->frame.w_height :
  73                 uframe->frame.dw_max_video_frame_buffer_size;
  74 }
  75
  76 static struct uvcg_format *find_format_by_index(struct uvc_device *uvc, int index)
  77 {
  78         struct uvcg_format_ptr *format;
  79         struct uvcg_format *uformat = NULL;
  80         int i = 1;
  81
  82         list_for_each_entry(format, &uvc->header->formats, entry) {
  83                 if (index == i) {
  84                         uformat = format->fmt;
  85                         break;
  86                 }
  87                 i++;
  88         }
  89
  90         return uformat;
  91 }
  92
  93 static struct uvcg_frame *find_frame_by_index(struct uvc_device *uvc,
  94                                        struct uvcg_format *uformat,
  95                                        int index)
  96 {
  97         struct uvcg_format_ptr *format;
  98         struct uvcg_frame_ptr *frame;
  99         struct uvcg_frame *uframe = NULL;
 100
 101         list_for_each_entry(format, &uvc->header->formats, entry) {
 102                 if (format->fmt->type != uformat->type)
 103                         continue;
 104                 list_for_each_entry(frame, &format->fmt->frames, entry) {
 105                         if (index == frame->frm->frame.b_frame_index) {
 106                                 uframe = frame->frm;
 107                                 break;
 108                         }
 109                 }
 110         }
 111
 112         return uframe;
 113 }
 114
 115 static struct uvcg_format *find_format_by_pix(struct uvc_device *uvc,
 116                                               u32 pixelformat)
 117 {
 118         struct uvcg_format_ptr *format;
 119         struct uvcg_format *uformat = NULL;
 120
 121         list_for_each_entry(format, &uvc->header->formats, entry) {
 122                 const struct uvc_format_desc *fmtdesc = to_uvc_format(format->fmt);
 123
 124                 if (fmtdesc->fcc == pixelformat) {
 125                         uformat = format->fmt;
 126                         break;
 127                 }
 128         }
 129
 130         return uformat;
 131 }
 132
 133 static struct uvcg_frame *find_closest_frame_by_size(struct uvc_device *uvc,
 134                                            struct uvcg_format *uformat,
 135                                            u16 rw, u16 rh)
 136 {
 137         struct uvc_video *video = &uvc->video;
 138         struct uvcg_format_ptr *format;
 139         struct uvcg_frame_ptr *frame;
 140         struct uvcg_frame *uframe = NULL;
 141         unsigned int d, maxd;
 142
 143         /* Find the closest image size. The distance between image sizes is
 144          * the size in pixels of the non-overlapping regions between the
 145          * requested size and the frame-specified size.
 146          */
 147         maxd = (unsigned int)-1;
 148
 149         list_for_each_entry(format, &uvc->header->formats, entry) {
 150                 if (format->fmt->type != uformat->type)
 151                         continue;
 152
 153                 list_for_each_entry(frame, &format->fmt->frames, entry) {
 154                         u16 w, h;
 155
 156                         w = frame->frm->frame.w_width;
 157                         h = frame->frm->frame.w_height;
 158
 159                         d = min(w, rw) * min(h, rh);
 160                         d = w*h + rw*rh - 2*d;
 161                         if (d < maxd) {
 162                                 maxd = d;
 163                                 uframe = frame->frm;
 164                         }
 165
 166                         if (maxd == 0)
 167                                 break;
 168                 }
 169         }
 170
 171         if (!uframe)
 172                 uvcg_dbg(&video->uvc->func, "Unsupported size %ux%u\n", rw, rh);
 173
 174         return uframe;
 175 }
 176
 177 /* --------------------------------------------------------------------------
 178  * Requests handling
 179  */
 180
 181 static int
 182 uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
 183 {
 184         struct usb_composite_dev *cdev = uvc->func.config->cdev;
 185         struct usb_request *req = uvc->control_req;
 186
 187         if (data->length < 0)
 188                 return usb_ep_set_halt(cdev->gadget->ep0);
 189
 190         req->length = min_t(unsigned int, uvc->event_length, data->length);
 191         req->zero = data->length < uvc->event_length;
 192
 193         memcpy(req->buf, data->data, req->length);
 194
 195         return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
 196 }
 197
 198 /* --------------------------------------------------------------------------
 199  * V4L2 ioctls
 200  */
 201
 202 static int
 203 uvc_v4l2_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
 204 {
 205         struct video_device *vdev = video_devdata(file);
 206         struct uvc_device *uvc = video_get_drvdata(vdev);
 207         struct usb_composite_dev *cdev = uvc->func.config->cdev;
 208
 209         strscpy(cap->driver, "g_uvc", sizeof(cap->driver));
 210         strscpy(cap->card, cdev->gadget->name, sizeof(cap->card));
 211         strscpy(cap->bus_info, dev_name(&cdev->gadget->dev),
 212                 sizeof(cap->bus_info));
 213         return 0;
 214 }
 215
 216 static int
 217 uvc_v4l2_get_format(struct file *file, void *fh, struct v4l2_format *fmt)
 218 {
 219         struct video_device *vdev = video_devdata(file);
 220         struct uvc_device *uvc = video_get_drvdata(vdev);
 221         struct uvc_video *video = &uvc->video;
 222
 223         fmt->fmt.pix.pixelformat = video->fcc;
 224         fmt->fmt.pix.width = video->width;
 225         fmt->fmt.pix.height = video->height;
 226         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 227         fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
 228         fmt->fmt.pix.sizeimage = video->imagesize;
 229         fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
 230         fmt->fmt.pix.priv = 0;
 231
 232         return 0;
 233 }
 234
 235 static int
 236 uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)
 237 {
 238         struct video_device *vdev = video_devdata(file);
 239         struct uvc_device *uvc = video_get_drvdata(vdev);
 240         struct uvc_video *video = &uvc->video;
 241         struct uvcg_format *uformat;
 242         struct uvcg_frame *uframe;
 243         u8 *fcc;
 244
 245         if (fmt->type != video->queue.queue.type)
 246                 return -EINVAL;
 247
 248         fcc = (u8 *)&fmt->fmt.pix.pixelformat;
 249         uvcg_dbg(&uvc->func, "Trying format 0x%08x (%c%c%c%c): %ux%u\n",
 250                 fmt->fmt.pix.pixelformat,
 251                 fcc[0], fcc[1], fcc[2], fcc[3],
 252                 fmt->fmt.pix.width, fmt->fmt.pix.height);
 253
 254         uformat = find_format_by_pix(uvc, fmt->fmt.pix.pixelformat);
 255         if (!uformat)
 256                 return -EINVAL;
 257
 258         uframe = find_closest_frame_by_size(uvc, uformat,
 259                                 fmt->fmt.pix.width, fmt->fmt.pix.height);
 260         if (!uframe)
 261                 return -EINVAL;
 262
 263         fmt->fmt.pix.width = uframe->frame.w_width;
 264         fmt->fmt.pix.height = uframe->frame.w_height;
 265         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 266         fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(uformat, uframe);
 267         fmt->fmt.pix.sizeimage = uvc_get_frame_size(uformat, uframe);
 268         fmt->fmt.pix.pixelformat = to_uvc_format(uformat)->fcc;
 269         fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
 270         fmt->fmt.pix.priv = 0;
 271
 272         return 0;
 273 }
 274
 275 static int
 276 uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
 277 {
 278         struct video_device *vdev = video_devdata(file);
 279         struct uvc_device *uvc = video_get_drvdata(vdev);
 280         struct uvc_video *video = &uvc->video;
 281         int ret;
 282
 283         ret = uvc_v4l2_try_format(file, fh, fmt);
 284         if (ret)
 285                 return ret;
 286
 287         video->fcc = fmt->fmt.pix.pixelformat;
 288         video->bpp = fmt->fmt.pix.bytesperline * 8 / video->width;
 289         video->width = fmt->fmt.pix.width;
 290         video->height = fmt->fmt.pix.height;
 291         video->imagesize = fmt->fmt.pix.sizeimage;
 292
 293         return ret;
 294 }
 295
 296 static int
 297 uvc_v4l2_enum_frameintervals(struct file *file, void *fh,
 298                 struct v4l2_frmivalenum *fival)
 299 {
 300         struct video_device *vdev = video_devdata(file);
 301         struct uvc_device *uvc = video_get_drvdata(vdev);
 302         struct uvcg_format *uformat = NULL;
 303         struct uvcg_frame *uframe = NULL;
 304         struct uvcg_frame_ptr *frame;
 305
 306         uformat = find_format_by_pix(uvc, fival->pixel_format);
 307         if (!uformat)
 308                 return -EINVAL;
 309
 310         list_for_each_entry(frame, &uformat->frames, entry) {
 311                 if (frame->frm->frame.w_width == fival->width &&
 312                     frame->frm->frame.w_height == fival->height) {
 313                         uframe = frame->frm;
 314                         break;
 315                 }
 316         }
 317         if (!uframe)
 318                 return -EINVAL;
 319
 320         if (fival->index >= uframe->frame.b_frame_interval_type)
 321                 return -EINVAL;
 322
 323         fival->discrete.numerator =
 324                 uframe->dw_frame_interval[fival->index];
 325
 326         /* TODO: handle V4L2_FRMIVAL_TYPE_STEPWISE */
 327         fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 328         fival->discrete.denominator = 10000000;
 329         v4l2_simplify_fraction(&fival->discrete.numerator,
 330                 &fival->discrete.denominator, 8, 333);
 331
 332         return 0;
 333 }
 334
 335 static int
 336 uvc_v4l2_enum_framesizes(struct file *file, void *fh,
 337                 struct v4l2_frmsizeenum *fsize)
 338 {
 339         struct video_device *vdev = video_devdata(file);
 340         struct uvc_device *uvc = video_get_drvdata(vdev);
 341         struct uvcg_format *uformat = NULL;
 342         struct uvcg_frame *uframe = NULL;
 343
 344         uformat = find_format_by_pix(uvc, fsize->pixel_format);
 345         if (!uformat)
 346                 return -EINVAL;
 347
 348         if (fsize->index >= uformat->num_frames)
 349                 return -EINVAL;
 350
 351         uframe = find_frame_by_index(uvc, uformat, fsize->index + 1);
 352         if (!uframe)
 353                 return -EINVAL;
 354
 355         fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 356         fsize->discrete.width = uframe->frame.w_width;
 357         fsize->discrete.height = uframe->frame.w_height;
 358
 359         return 0;
 360 }
 361
 362 static int
 363 uvc_v4l2_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
 364 {
 365         struct video_device *vdev = video_devdata(file);
 366         struct uvc_device *uvc = video_get_drvdata(vdev);
 367         const struct uvc_format_desc *fmtdesc;
 368         struct uvcg_format *uformat;
 369
 370         if (f->index >= uvc->header->num_fmt)
 371                 return -EINVAL;
 372
 373         uformat = find_format_by_index(uvc, f->index + 1);
 374         if (!uformat)
 375                 return -EINVAL;
 376
 377         fmtdesc = to_uvc_format(uformat);
 378         f->pixelformat = fmtdesc->fcc;
 379
 380         return 0;
 381 }
 382
 383 static int
 384 uvc_v4l2_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b)
 385 {
 386         struct video_device *vdev = video_devdata(file);
 387         struct uvc_device *uvc = video_get_drvdata(vdev);
 388         struct uvc_video *video = &uvc->video;
 389
 390         if (b->type != video->queue.queue.type)
 391                 return -EINVAL;
 392
 393         return uvcg_alloc_buffers(&video->queue, b);
 394 }
 395
 396 static int
 397 uvc_v4l2_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
 398 {
 399         struct video_device *vdev = video_devdata(file);
 400         struct uvc_device *uvc = video_get_drvdata(vdev);
 401         struct uvc_video *video = &uvc->video;
 402
 403         return uvcg_query_buffer(&video->queue, b);
 404 }
 405
 406 static int
 407 uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 408 {
 409         struct video_device *vdev = video_devdata(file);
 410         struct uvc_device *uvc = video_get_drvdata(vdev);
 411         struct uvc_video *video = &uvc->video;
 412         int ret;
 413
 414         ret = uvcg_queue_buffer(&video->queue, b);
 415         if (ret < 0)
 416                 return ret;
 417
 418         if (uvc->state == UVC_STATE_STREAMING)
 419                 queue_work(video->async_wq, &video->pump);
 420
 421         return ret;
 422 }
 423
 424 static int
 425 uvc_v4l2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 426 {
 427         struct video_device *vdev = video_devdata(file);
 428         struct uvc_device *uvc = video_get_drvdata(vdev);
 429         struct uvc_video *video = &uvc->video;
 430
 431         return uvcg_dequeue_buffer(&video->queue, b, file->f_flags & O_NONBLOCK);
 432 }
 433
 434 static int
 435 uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
 436 {
 437         struct video_device *vdev = video_devdata(file);
 438         struct uvc_device *uvc = video_get_drvdata(vdev);
 439         struct uvc_video *video = &uvc->video;
 440         int ret;
 441
 442         if (type != video->queue.queue.type)
 443                 return -EINVAL;
 444
 445         /* Enable UVC video. */
 446         ret = uvcg_video_enable(video, 1);
 447         if (ret < 0)
 448                 return ret;
 449
 450         /*
 451          * Complete the alternate setting selection setup phase now that
 452          * userspace is ready to provide video frames.
 453          */
 454         uvc_function_setup_continue(uvc);
 455         uvc->state = UVC_STATE_STREAMING;
 456
 457         return 0;
 458 }
 459
 460 static int
 461 uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
 462 {
 463         struct video_device *vdev = video_devdata(file);
 464         struct uvc_device *uvc = video_get_drvdata(vdev);
 465         struct uvc_video *video = &uvc->video;
 466
 467         if (type != video->queue.queue.type)
 468                 return -EINVAL;
 469
 470         return uvcg_video_enable(video, 0);
 471 }
 472
 473 static int
 474 uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
 475                          const struct v4l2_event_subscription *sub)
 476 {
 477         struct uvc_device *uvc = video_get_drvdata(fh->vdev);
 478         struct uvc_file_handle *handle = to_uvc_file_handle(fh);
 479         int ret;
 480
 481         if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
 482                 return -EINVAL;
 483
 484         if (sub->type == UVC_EVENT_SETUP && uvc->func_connected)
 485                 return -EBUSY;
 486
 487         ret = v4l2_event_subscribe(fh, sub, 2, NULL);
 488         if (ret < 0)
 489                 return ret;
 490
 491         if (sub->type == UVC_EVENT_SETUP) {
 492                 uvc->func_connected = true;
 493                 handle->is_uvc_app_handle = true;
 494                 uvc_function_connect(uvc);
 495         }
 496
 497         return 0;
 498 }
 499
 500 static void uvc_v4l2_disable(struct uvc_device *uvc)
 501 {
 502         uvc_function_disconnect(uvc);
 503         uvcg_video_enable(&uvc->video, 0);
 504         uvcg_free_buffers(&uvc->video.queue);
 505         uvc->func_connected = false;
 506         wake_up_interruptible(&uvc->func_connected_queue);
 507 }
 508
 509 static int
 510 uvc_v4l2_unsubscribe_event(struct v4l2_fh *fh,
 511                            const struct v4l2_event_subscription *sub)
 512 {
 513         struct uvc_device *uvc = video_get_drvdata(fh->vdev);
 514         struct uvc_file_handle *handle = to_uvc_file_handle(fh);
 515         int ret;
 516
 517         ret = v4l2_event_unsubscribe(fh, sub);
 518         if (ret < 0)
 519                 return ret;
 520
 521         if (sub->type == UVC_EVENT_SETUP && handle->is_uvc_app_handle) {
 522                 uvc_v4l2_disable(uvc);
 523                 handle->is_uvc_app_handle = false;
 524         }
 525
 526         return 0;
 527 }
 528
 529 static long
 530 uvc_v4l2_ioctl_default(struct file *file, void *fh, bool valid_prio,
 531                        unsigned int cmd, void *arg)
 532 {
 533         struct video_device *vdev = video_devdata(file);
 534         struct uvc_device *uvc = video_get_drvdata(vdev);
 535
 536         switch (cmd) {
 537         case UVCIOC_SEND_RESPONSE:
 538                 return uvc_send_response(uvc, arg);
 539
 540         default:
 541                 return -ENOIOCTLCMD;
 542         }
 543 }
 544
 545 const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {
 546         .vidioc_querycap = uvc_v4l2_querycap,
 547         .vidioc_try_fmt_vid_out = uvc_v4l2_try_format,
 548         .vidioc_g_fmt_vid_out = uvc_v4l2_get_format,
 549         .vidioc_s_fmt_vid_out = uvc_v4l2_set_format,
 550         .vidioc_enum_frameintervals = uvc_v4l2_enum_frameintervals,
 551         .vidioc_enum_framesizes = uvc_v4l2_enum_framesizes,
 552         .vidioc_enum_fmt_vid_out = uvc_v4l2_enum_format,
 553         .vidioc_reqbufs = uvc_v4l2_reqbufs,
 554         .vidioc_querybuf = uvc_v4l2_querybuf,
 555         .vidioc_qbuf = uvc_v4l2_qbuf,
 556         .vidioc_dqbuf = uvc_v4l2_dqbuf,
 557         .vidioc_streamon = uvc_v4l2_streamon,
 558         .vidioc_streamoff = uvc_v4l2_streamoff,
 559         .vidioc_subscribe_event = uvc_v4l2_subscribe_event,
 560         .vidioc_unsubscribe_event = uvc_v4l2_unsubscribe_event,
 561         .vidioc_default = uvc_v4l2_ioctl_default,
 562 };
 563
 564 /* --------------------------------------------------------------------------
 565  * V4L2
 566  */
 567
 568 static int
 569 uvc_v4l2_open(struct file *file)
 570 {
 571         struct video_device *vdev = video_devdata(file);
 572         struct uvc_device *uvc = video_get_drvdata(vdev);
 573         struct uvc_file_handle *handle;
 574
 575         handle = kzalloc(sizeof(*handle), GFP_KERNEL);
 576         if (handle == NULL)
 577                 return -ENOMEM;
 578
 579         v4l2_fh_init(&handle->vfh, vdev);
 580         v4l2_fh_add(&handle->vfh);
 581
 582         handle->device = &uvc->video;
 583         file->private_data = &handle->vfh;
 584
 585         return 0;
 586 }
 587
 588 static int
 589 uvc_v4l2_release(struct file *file)
 590 {
 591         struct video_device *vdev = video_devdata(file);
 592         struct uvc_device *uvc = video_get_drvdata(vdev);
 593         struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
 594         struct uvc_video *video = handle->device;
 595
 596         mutex_lock(&video->mutex);
 597         if (handle->is_uvc_app_handle)
 598                 uvc_v4l2_disable(uvc);
 599         mutex_unlock(&video->mutex);
 600
 601         file->private_data = NULL;
 602         v4l2_fh_del(&handle->vfh);
 603         v4l2_fh_exit(&handle->vfh);
 604         kfree(handle);
 605
 606         return 0;
 607 }
 608
 609 static int
 610 uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
 611 {
 612         struct video_device *vdev = video_devdata(file);
 613         struct uvc_device *uvc = video_get_drvdata(vdev);
 614
 615         return uvcg_queue_mmap(&uvc->video.queue, vma);
 616 }
 617
 618 static __poll_t
 619 uvc_v4l2_poll(struct file *file, poll_table *wait)
 620 {
 621         struct video_device *vdev = video_devdata(file);
 622         struct uvc_device *uvc = video_get_drvdata(vdev);
 623
 624         return uvcg_queue_poll(&uvc->video.queue, file, wait);
 625 }
 626
 627 #ifndef CONFIG_MMU
 628 static unsigned long uvcg_v4l2_get_unmapped_area(struct file *file,
 629                 unsigned long addr, unsigned long len, unsigned long pgoff,
 630                 unsigned long flags)
 631 {
 632         struct video_device *vdev = video_devdata(file);
 633         struct uvc_device *uvc = video_get_drvdata(vdev);
 634
 635         return uvcg_queue_get_unmapped_area(&uvc->video.queue, pgoff);
 636 }
 637 #endif
 638
 639 const struct v4l2_file_operations uvc_v4l2_fops = {
 640         .owner          = THIS_MODULE,
 641         .open           = uvc_v4l2_open,
 642         .release        = uvc_v4l2_release,
 643         .unlocked_ioctl = video_ioctl2,
 644         .mmap           = uvc_v4l2_mmap,
 645         .poll           = uvc_v4l2_poll,
 646 #ifndef CONFIG_MMU
 647         .get_unmapped_area = uvcg_v4l2_get_unmapped_area,
 648 #endif
 649 };
 650