drivers/media/video/uvc/uvc_v4l2.c

   1 /*
   2  *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
   3  *
   4  *      Copyright (C) 2005-2010
   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/version.h>
  16 #include <linux/list.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/usb.h>
  20 #include <linux/videodev2.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/mm.h>
  23 #include <linux/wait.h>
  24 #include <linux/atomic.h>
  25
  26 #include <media/v4l2-common.h>
  27 #include <media/v4l2-ioctl.h>
  28
  29 #include "uvcvideo.h"
  30
  31 /* ------------------------------------------------------------------------
  32  * UVC ioctls
  33  */
  34 static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
  35         struct uvc_xu_control_mapping *xmap)
  36 {
  37         struct uvc_control_mapping *map;
  38         unsigned int size;
  39         int ret;
  40
  41         map = kzalloc(sizeof *map, GFP_KERNEL);
  42         if (map == NULL)
  43                 return -ENOMEM;
  44
  45         map->id = xmap->id;
  46         memcpy(map->name, xmap->name, sizeof map->name);
  47         memcpy(map->entity, xmap->entity, sizeof map->entity);
  48         map->selector = xmap->selector;
  49         map->size = xmap->size;
  50         map->offset = xmap->offset;
  51         map->v4l2_type = xmap->v4l2_type;
  52         map->data_type = xmap->data_type;
  53
  54         switch (xmap->v4l2_type) {
  55         case V4L2_CTRL_TYPE_INTEGER:
  56         case V4L2_CTRL_TYPE_BOOLEAN:
  57         case V4L2_CTRL_TYPE_BUTTON:
  58                 break;
  59
  60         case V4L2_CTRL_TYPE_MENU:
  61                 /* Prevent excessive memory consumption, as well as integer
  62                  * overflows.
  63                  */
  64                 if (xmap->menu_count == 0 ||
  65                     xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
  66                         ret = -EINVAL;
  67                         goto done;
  68                 }
  69
  70                 size = xmap->menu_count * sizeof(*map->menu_info);
  71                 map->menu_info = kmalloc(size, GFP_KERNEL);
  72                 if (map->menu_info == NULL) {
  73                         ret = -ENOMEM;
  74                         goto done;
  75                 }
  76
  77                 if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
  78                         ret = -EFAULT;
  79                         goto done;
  80                 }
  81
  82                 map->menu_count = xmap->menu_count;
  83                 break;
  84
  85         default:
  86                 uvc_trace(UVC_TRACE_CONTROL, "Unsupported V4L2 control type "
  87                           "%u.\n", xmap->v4l2_type);
  88                 ret = -ENOTTY;
  89                 goto done;
  90         }
  91
  92         ret = uvc_ctrl_add_mapping(chain, map);
  93
  94 done:
  95         kfree(map->menu_info);
  96         kfree(map);
  97
  98         return ret;
  99 }
 100
 101 /* ------------------------------------------------------------------------
 102  * V4L2 interface
 103  */
 104
 105 /*
 106  * Find the frame interval closest to the requested frame interval for the
 107  * given frame format and size. This should be done by the device as part of
 108  * the Video Probe and Commit negotiation, but some hardware don't implement
 109  * that feature.
 110  */
 111 static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
 112 {
 113         unsigned int i;
 114
 115         if (frame->bFrameIntervalType) {
 116                 __u32 best = -1, dist;
 117
 118                 for (i = 0; i < frame->bFrameIntervalType; ++i) {
 119                         dist = interval > frame->dwFrameInterval[i]
 120                              ? interval - frame->dwFrameInterval[i]
 121                              : frame->dwFrameInterval[i] - interval;
 122
 123                         if (dist > best)
 124                                 break;
 125
 126                         best = dist;
 127                 }
 128
 129                 interval = frame->dwFrameInterval[i-1];
 130         } else {
 131                 const __u32 min = frame->dwFrameInterval[0];
 132                 const __u32 max = frame->dwFrameInterval[1];
 133                 const __u32 step = frame->dwFrameInterval[2];
 134
 135                 interval = min + (interval - min + step/2) / step * step;
 136                 if (interval > max)
 137                         interval = max;
 138         }
 139
 140         return interval;
 141 }
 142
 143 static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 144         struct v4l2_format *fmt, struct uvc_streaming_control *probe,
 145         struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
 146 {
 147         struct uvc_format *format = NULL;
 148         struct uvc_frame *frame = NULL;
 149         __u16 rw, rh;
 150         unsigned int d, maxd;
 151         unsigned int i;
 152         __u32 interval;
 153         int ret = 0;
 154         __u8 *fcc;
 155
 156         if (fmt->type != stream->type)
 157                 return -EINVAL;
 158
 159         fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
 160         uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
 161                         fmt->fmt.pix.pixelformat,
 162                         fcc[0], fcc[1], fcc[2], fcc[3],
 163                         fmt->fmt.pix.width, fmt->fmt.pix.height);
 164
 165         /* Check if the hardware supports the requested format. */
 166         for (i = 0; i < stream->nformats; ++i) {
 167                 format = &stream->format[i];
 168                 if (format->fcc == fmt->fmt.pix.pixelformat)
 169                         break;
 170         }
 171
 172         if (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
 173                 uvc_trace(UVC_TRACE_FORMAT, "Unsupported format 0x%08x.\n",
 174                                 fmt->fmt.pix.pixelformat);
 175                 return -EINVAL;
 176         }
 177
 178         /* Find the closest image size. The distance between image sizes is
 179          * the size in pixels of the non-overlapping regions between the
 180          * requested size and the frame-specified size.
 181          */
 182         rw = fmt->fmt.pix.width;
 183         rh = fmt->fmt.pix.height;
 184         maxd = (unsigned int)-1;
 185
 186         for (i = 0; i < format->nframes; ++i) {
 187                 __u16 w = format->frame[i].wWidth;
 188                 __u16 h = format->frame[i].wHeight;
 189
 190                 d = min(w, rw) * min(h, rh);
 191                 d = w*h + rw*rh - 2*d;
 192                 if (d < maxd) {
 193                         maxd = d;
 194                         frame = &format->frame[i];
 195                 }
 196
 197                 if (maxd == 0)
 198                         break;
 199         }
 200
 201         if (frame == NULL) {
 202                 uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
 203                                 fmt->fmt.pix.width, fmt->fmt.pix.height);
 204                 return -EINVAL;
 205         }
 206
 207         /* Use the default frame interval. */
 208         interval = frame->dwDefaultFrameInterval;
 209         uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
 210                 "(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
 211                 (100000000/interval)%10);
 212
 213         /* Set the format index, frame index and frame interval. */
 214         memset(probe, 0, sizeof *probe);
 215         probe->bmHint = 1;      /* dwFrameInterval */
 216         probe->bFormatIndex = format->index;
 217         probe->bFrameIndex = frame->bFrameIndex;
 218         probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
 219         /* Some webcams stall the probe control set request when the
 220          * dwMaxVideoFrameSize field is set to zero. The UVC specification
 221          * clearly states that the field is read-only from the host, so this
 222          * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
 223          * the webcam to work around the problem.
 224          *
 225          * The workaround could probably be enabled for all webcams, so the
 226          * quirk can be removed if needed. It's currently useful to detect
 227          * webcam bugs and fix them before they hit the market (providing
 228          * developers test their webcams with the Linux driver as well as with
 229          * the Windows driver).
 230          */
 231         mutex_lock(&stream->mutex);
 232         if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
 233                 probe->dwMaxVideoFrameSize =
 234                         stream->ctrl.dwMaxVideoFrameSize;
 235
 236         /* Probe the device. */
 237         ret = uvc_probe_video(stream, probe);
 238         mutex_unlock(&stream->mutex);
 239         if (ret < 0)
 240                 goto done;
 241
 242         fmt->fmt.pix.width = frame->wWidth;
 243         fmt->fmt.pix.height = frame->wHeight;
 244         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 245         fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
 246         fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
 247         fmt->fmt.pix.colorspace = format->colorspace;
 248         fmt->fmt.pix.priv = 0;
 249
 250         if (uvc_format != NULL)
 251                 *uvc_format = format;
 252         if (uvc_frame != NULL)
 253                 *uvc_frame = frame;
 254
 255 done:
 256         return ret;
 257 }
 258
 259 static int uvc_v4l2_get_format(struct uvc_streaming *stream,
 260         struct v4l2_format *fmt)
 261 {
 262         struct uvc_format *format;
 263         struct uvc_frame *frame;
 264         int ret = 0;
 265
 266         if (fmt->type != stream->type)
 267                 return -EINVAL;
 268
 269         mutex_lock(&stream->mutex);
 270         format = stream->cur_format;
 271         frame = stream->cur_frame;
 272
 273         if (format == NULL || frame == NULL) {
 274                 ret = -EINVAL;
 275                 goto done;
 276         }
 277
 278         fmt->fmt.pix.pixelformat = format->fcc;
 279         fmt->fmt.pix.width = frame->wWidth;
 280         fmt->fmt.pix.height = frame->wHeight;
 281         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 282         fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
 283         fmt->fmt.pix.sizeimage = stream->ctrl.dwMaxVideoFrameSize;
 284         fmt->fmt.pix.colorspace = format->colorspace;
 285         fmt->fmt.pix.priv = 0;
 286
 287 done:
 288         mutex_unlock(&stream->mutex);
 289         return ret;
 290 }
 291
 292 static int uvc_v4l2_set_format(struct uvc_streaming *stream,
 293         struct v4l2_format *fmt)
 294 {
 295         struct uvc_streaming_control probe;
 296         struct uvc_format *format;
 297         struct uvc_frame *frame;
 298         int ret;
 299
 300         if (fmt->type != stream->type)
 301                 return -EINVAL;
 302
 303         ret = uvc_v4l2_try_format(stream, fmt, &probe, &format, &frame);
 304         if (ret < 0)
 305                 return ret;
 306
 307         mutex_lock(&stream->mutex);
 308
 309         if (uvc_queue_allocated(&stream->queue)) {
 310                 ret = -EBUSY;
 311                 goto done;
 312         }
 313
 314         memcpy(&stream->ctrl, &probe, sizeof probe);
 315         stream->cur_format = format;
 316         stream->cur_frame = frame;
 317
 318 done:
 319         mutex_unlock(&stream->mutex);
 320         return ret;
 321 }
 322
 323 static int uvc_v4l2_get_streamparm(struct uvc_streaming *stream,
 324                 struct v4l2_streamparm *parm)
 325 {
 326         uint32_t numerator, denominator;
 327
 328         if (parm->type != stream->type)
 329                 return -EINVAL;
 330
 331         mutex_lock(&stream->mutex);
 332         numerator = stream->ctrl.dwFrameInterval;
 333         mutex_unlock(&stream->mutex);
 334
 335         denominator = 10000000;
 336         uvc_simplify_fraction(&numerator, &denominator, 8, 333);
 337
 338         memset(parm, 0, sizeof *parm);
 339         parm->type = stream->type;
 340
 341         if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
 342                 parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
 343                 parm->parm.capture.capturemode = 0;
 344                 parm->parm.capture.timeperframe.numerator = numerator;
 345                 parm->parm.capture.timeperframe.denominator = denominator;
 346                 parm->parm.capture.extendedmode = 0;
 347                 parm->parm.capture.readbuffers = 0;
 348         } else {
 349                 parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
 350                 parm->parm.output.outputmode = 0;
 351                 parm->parm.output.timeperframe.numerator = numerator;
 352                 parm->parm.output.timeperframe.denominator = denominator;
 353         }
 354
 355         return 0;
 356 }
 357
 358 static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
 359                 struct v4l2_streamparm *parm)
 360 {
 361         struct uvc_streaming_control probe;
 362         struct v4l2_fract timeperframe;
 363         uint32_t interval;
 364         int ret;
 365
 366         if (parm->type != stream->type)
 367                 return -EINVAL;
 368
 369         if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 370                 timeperframe = parm->parm.capture.timeperframe;
 371         else
 372                 timeperframe = parm->parm.output.timeperframe;
 373
 374         interval = uvc_fraction_to_interval(timeperframe.numerator,
 375                 timeperframe.denominator);
 376         uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
 377                 timeperframe.numerator, timeperframe.denominator, interval);
 378
 379         mutex_lock(&stream->mutex);
 380
 381         if (uvc_queue_streaming(&stream->queue)) {
 382                 mutex_unlock(&stream->mutex);
 383                 return -EBUSY;
 384         }
 385
 386         memcpy(&probe, &stream->ctrl, sizeof probe);
 387         probe.dwFrameInterval =
 388                 uvc_try_frame_interval(stream->cur_frame, interval);
 389
 390         /* Probe the device with the new settings. */
 391         ret = uvc_probe_video(stream, &probe);
 392         if (ret < 0) {
 393                 mutex_unlock(&stream->mutex);
 394                 return ret;
 395         }
 396
 397         memcpy(&stream->ctrl, &probe, sizeof probe);
 398         mutex_unlock(&stream->mutex);
 399
 400         /* Return the actual frame period. */
 401         timeperframe.numerator = probe.dwFrameInterval;
 402         timeperframe.denominator = 10000000;
 403         uvc_simplify_fraction(&timeperframe.numerator,
 404                 &timeperframe.denominator, 8, 333);
 405
 406         if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 407                 parm->parm.capture.timeperframe = timeperframe;
 408         else
 409                 parm->parm.output.timeperframe = timeperframe;
 410
 411         return 0;
 412 }
 413
 414 /* ------------------------------------------------------------------------
 415  * Privilege management
 416  */
 417
 418 /*
 419  * Privilege management is the multiple-open implementation basis. The current
 420  * implementation is completely transparent for the end-user and doesn't
 421  * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
 422  * Those ioctls enable finer control on the device (by making possible for a
 423  * user to request exclusive access to a device), but are not mature yet.
 424  * Switching to the V4L2 priority mechanism might be considered in the future
 425  * if this situation changes.
 426  *
 427  * Each open instance of a UVC device can either be in a privileged or
 428  * unprivileged state. Only a single instance can be in a privileged state at
 429  * a given time. Trying to perform an operation that requires privileges will
 430  * automatically acquire the required privileges if possible, or return -EBUSY
 431  * otherwise. Privileges are dismissed when closing the instance or when
 432  * freeing the video buffers using VIDIOC_REQBUFS.
 433  *
 434  * Operations that require privileges are:
 435  *
 436  * - VIDIOC_S_INPUT
 437  * - VIDIOC_S_PARM
 438  * - VIDIOC_S_FMT
 439  * - VIDIOC_REQBUFS
 440  */
 441 static int uvc_acquire_privileges(struct uvc_fh *handle)
 442 {
 443         /* Always succeed if the handle is already privileged. */
 444         if (handle->state == UVC_HANDLE_ACTIVE)
 445                 return 0;
 446
 447         /* Check if the device already has a privileged handle. */
 448         if (atomic_inc_return(&handle->stream->active) != 1) {
 449                 atomic_dec(&handle->stream->active);
 450                 return -EBUSY;
 451         }
 452
 453         handle->state = UVC_HANDLE_ACTIVE;
 454         return 0;
 455 }
 456
 457 static void uvc_dismiss_privileges(struct uvc_fh *handle)
 458 {
 459         if (handle->state == UVC_HANDLE_ACTIVE)
 460                 atomic_dec(&handle->stream->active);
 461
 462         handle->state = UVC_HANDLE_PASSIVE;
 463 }
 464
 465 static int uvc_has_privileges(struct uvc_fh *handle)
 466 {
 467         return handle->state == UVC_HANDLE_ACTIVE;
 468 }
 469
 470 /* ------------------------------------------------------------------------
 471  * V4L2 file operations
 472  */
 473
 474 static int uvc_v4l2_open(struct file *file)
 475 {
 476         struct uvc_streaming *stream;
 477         struct uvc_fh *handle;
 478         int ret = 0;
 479
 480         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
 481         stream = video_drvdata(file);
 482
 483         if (stream->dev->state & UVC_DEV_DISCONNECTED)
 484                 return -ENODEV;
 485
 486         ret = usb_autopm_get_interface(stream->dev->intf);
 487         if (ret < 0)
 488                 return ret;
 489
 490         /* Create the device handle. */
 491         handle = kzalloc(sizeof *handle, GFP_KERNEL);
 492         if (handle == NULL) {
 493                 usb_autopm_put_interface(stream->dev->intf);
 494                 return -ENOMEM;
 495         }
 496
 497         if (atomic_inc_return(&stream->dev->users) == 1) {
 498                 ret = uvc_status_start(stream->dev);
 499                 if (ret < 0) {
 500                         usb_autopm_put_interface(stream->dev->intf);
 501                         atomic_dec(&stream->dev->users);
 502                         kfree(handle);
 503                         return ret;
 504                 }
 505         }
 506
 507         handle->chain = stream->chain;
 508         handle->stream = stream;
 509         handle->state = UVC_HANDLE_PASSIVE;
 510         file->private_data = handle;
 511
 512         return 0;
 513 }
 514
 515 static int uvc_v4l2_release(struct file *file)
 516 {
 517         struct uvc_fh *handle = file->private_data;
 518         struct uvc_streaming *stream = handle->stream;
 519
 520         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");
 521
 522         /* Only free resources if this is a privileged handle. */
 523         if (uvc_has_privileges(handle)) {
 524                 uvc_video_enable(stream, 0);
 525                 uvc_free_buffers(&stream->queue);
 526         }
 527
 528         /* Release the file handle. */
 529         uvc_dismiss_privileges(handle);
 530         kfree(handle);
 531         file->private_data = NULL;
 532
 533         if (atomic_dec_return(&stream->dev->users) == 0)
 534                 uvc_status_stop(stream->dev);
 535
 536         usb_autopm_put_interface(stream->dev->intf);
 537         return 0;
 538 }
 539
 540 static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 541 {
 542         struct video_device *vdev = video_devdata(file);
 543         struct uvc_fh *handle = file->private_data;
 544         struct uvc_video_chain *chain = handle->chain;
 545         struct uvc_streaming *stream = handle->stream;
 546         long ret = 0;
 547
 548         switch (cmd) {
 549         /* Query capabilities */
 550         case VIDIOC_QUERYCAP:
 551         {
 552                 struct v4l2_capability *cap = arg;
 553
 554                 memset(cap, 0, sizeof *cap);
 555                 strlcpy(cap->driver, "uvcvideo", sizeof cap->driver);
 556                 strlcpy(cap->card, vdev->name, sizeof cap->card);
 557                 usb_make_path(stream->dev->udev,
 558                               cap->bus_info, sizeof(cap->bus_info));
 559                 cap->version = LINUX_VERSION_CODE;
 560                 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 561                         cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
 562                                           | V4L2_CAP_STREAMING;
 563                 else
 564                         cap->capabilities = V4L2_CAP_VIDEO_OUTPUT
 565                                           | V4L2_CAP_STREAMING;
 566                 break;
 567         }
 568
 569         /* Get, Set & Query control */
 570         case VIDIOC_QUERYCTRL:
 571                 return uvc_query_v4l2_ctrl(chain, arg);
 572
 573         case VIDIOC_G_CTRL:
 574         {
 575                 struct v4l2_control *ctrl = arg;
 576                 struct v4l2_ext_control xctrl;
 577
 578                 memset(&xctrl, 0, sizeof xctrl);
 579                 xctrl.id = ctrl->id;
 580
 581                 ret = uvc_ctrl_begin(chain);
 582                 if (ret < 0)
 583                         return ret;
 584
 585                 ret = uvc_ctrl_get(chain, &xctrl);
 586                 uvc_ctrl_rollback(chain);
 587                 if (ret >= 0)
 588                         ctrl->value = xctrl.value;
 589                 break;
 590         }
 591
 592         case VIDIOC_S_CTRL:
 593         {
 594                 struct v4l2_control *ctrl = arg;
 595                 struct v4l2_ext_control xctrl;
 596
 597                 memset(&xctrl, 0, sizeof xctrl);
 598                 xctrl.id = ctrl->id;
 599                 xctrl.value = ctrl->value;
 600
 601                 ret = uvc_ctrl_begin(chain);
 602                 if (ret < 0)
 603                         return ret;
 604
 605                 ret = uvc_ctrl_set(chain, &xctrl);
 606                 if (ret < 0) {
 607                         uvc_ctrl_rollback(chain);
 608                         return ret;
 609                 }
 610                 ret = uvc_ctrl_commit(chain);
 611                 if (ret == 0)
 612                         ctrl->value = xctrl.value;
 613                 break;
 614         }
 615
 616         case VIDIOC_QUERYMENU:
 617                 return uvc_query_v4l2_menu(chain, arg);
 618
 619         case VIDIOC_G_EXT_CTRLS:
 620         {
 621                 struct v4l2_ext_controls *ctrls = arg;
 622                 struct v4l2_ext_control *ctrl = ctrls->controls;
 623                 unsigned int i;
 624
 625                 ret = uvc_ctrl_begin(chain);
 626                 if (ret < 0)
 627                         return ret;
 628
 629                 for (i = 0; i < ctrls->count; ++ctrl, ++i) {
 630                         ret = uvc_ctrl_get(chain, ctrl);
 631                         if (ret < 0) {
 632                                 uvc_ctrl_rollback(chain);
 633                                 ctrls->error_idx = i;
 634                                 return ret;
 635                         }
 636                 }
 637                 ctrls->error_idx = 0;
 638                 ret = uvc_ctrl_rollback(chain);
 639                 break;
 640         }
 641
 642         case VIDIOC_S_EXT_CTRLS:
 643         case VIDIOC_TRY_EXT_CTRLS:
 644         {
 645                 struct v4l2_ext_controls *ctrls = arg;
 646                 struct v4l2_ext_control *ctrl = ctrls->controls;
 647                 unsigned int i;
 648
 649                 ret = uvc_ctrl_begin(chain);
 650                 if (ret < 0)
 651                         return ret;
 652
 653                 for (i = 0; i < ctrls->count; ++ctrl, ++i) {
 654                         ret = uvc_ctrl_set(chain, ctrl);
 655                         if (ret < 0) {
 656                                 uvc_ctrl_rollback(chain);
 657                                 ctrls->error_idx = i;
 658                                 return ret;
 659                         }
 660                 }
 661
 662                 ctrls->error_idx = 0;
 663
 664                 if (cmd == VIDIOC_S_EXT_CTRLS)
 665                         ret = uvc_ctrl_commit(chain);
 666                 else
 667                         ret = uvc_ctrl_rollback(chain);
 668                 break;
 669         }
 670
 671         /* Get, Set & Enum input */
 672         case VIDIOC_ENUMINPUT:
 673         {
 674                 const struct uvc_entity *selector = chain->selector;
 675                 struct v4l2_input *input = arg;
 676                 struct uvc_entity *iterm = NULL;
 677                 u32 index = input->index;
 678                 int pin = 0;
 679
 680                 if (selector == NULL ||
 681                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 682                         if (index != 0)
 683                                 return -EINVAL;
 684                         list_for_each_entry(iterm, &chain->entities, chain) {
 685                                 if (UVC_ENTITY_IS_ITERM(iterm))
 686                                         break;
 687                         }
 688                         pin = iterm->id;
 689                 } else if (pin < selector->bNrInPins) {
 690                         pin = selector->baSourceID[index];
 691                         list_for_each_entry(iterm, &chain->entities, chain) {
 692                                 if (!UVC_ENTITY_IS_ITERM(iterm))
 693                                         continue;
 694                                 if (iterm->id == pin)
 695                                         break;
 696                         }
 697                 }
 698
 699                 if (iterm == NULL || iterm->id != pin)
 700                         return -EINVAL;
 701
 702                 memset(input, 0, sizeof *input);
 703                 input->index = index;
 704                 strlcpy(input->name, iterm->name, sizeof input->name);
 705                 if (UVC_ENTITY_TYPE(iterm) == UVC_ITT_CAMERA)
 706                         input->type = V4L2_INPUT_TYPE_CAMERA;
 707                 break;
 708         }
 709
 710         case VIDIOC_G_INPUT:
 711         {
 712                 u8 input;
 713
 714                 if (chain->selector == NULL ||
 715                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 716                         *(int *)arg = 0;
 717                         break;
 718                 }
 719
 720                 ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
 721                         chain->selector->id, chain->dev->intfnum,
 722                         UVC_SU_INPUT_SELECT_CONTROL, &input, 1);
 723                 if (ret < 0)
 724                         return ret;
 725
 726                 *(int *)arg = input - 1;
 727                 break;
 728         }
 729
 730         case VIDIOC_S_INPUT:
 731         {
 732                 u32 input = *(u32 *)arg + 1;
 733
 734                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 735                         return ret;
 736
 737                 if (chain->selector == NULL ||
 738                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 739                         if (input != 1)
 740                                 return -EINVAL;
 741                         break;
 742                 }
 743
 744                 if (input == 0 || input > chain->selector->bNrInPins)
 745                         return -EINVAL;
 746
 747                 return uvc_query_ctrl(chain->dev, UVC_SET_CUR,
 748                         chain->selector->id, chain->dev->intfnum,
 749                         UVC_SU_INPUT_SELECT_CONTROL, &input, 1);
 750         }
 751
 752         /* Try, Get, Set & Enum format */
 753         case VIDIOC_ENUM_FMT:
 754         {
 755                 struct v4l2_fmtdesc *fmt = arg;
 756                 struct uvc_format *format;
 757                 enum v4l2_buf_type type = fmt->type;
 758                 __u32 index = fmt->index;
 759
 760                 if (fmt->type != stream->type ||
 761                     fmt->index >= stream->nformats)
 762                         return -EINVAL;
 763
 764                 memset(fmt, 0, sizeof(*fmt));
 765                 fmt->index = index;
 766                 fmt->type = type;
 767
 768                 format = &stream->format[fmt->index];
 769                 fmt->flags = 0;
 770                 if (format->flags & UVC_FMT_FLAG_COMPRESSED)
 771                         fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
 772                 strlcpy(fmt->description, format->name,
 773                         sizeof fmt->description);
 774                 fmt->description[sizeof fmt->description - 1] = 0;
 775                 fmt->pixelformat = format->fcc;
 776                 break;
 777         }
 778
 779         case VIDIOC_TRY_FMT:
 780         {
 781                 struct uvc_streaming_control probe;
 782
 783                 return uvc_v4l2_try_format(stream, arg, &probe, NULL, NULL);
 784         }
 785
 786         case VIDIOC_S_FMT:
 787                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 788                         return ret;
 789
 790                 return uvc_v4l2_set_format(stream, arg);
 791
 792         case VIDIOC_G_FMT:
 793                 return uvc_v4l2_get_format(stream, arg);
 794
 795         /* Frame size enumeration */
 796         case VIDIOC_ENUM_FRAMESIZES:
 797         {
 798                 struct v4l2_frmsizeenum *fsize = arg;
 799                 struct uvc_format *format = NULL;
 800                 struct uvc_frame *frame;
 801                 int i;
 802
 803                 /* Look for the given pixel format */
 804                 for (i = 0; i < stream->nformats; i++) {
 805                         if (stream->format[i].fcc ==
 806                                         fsize->pixel_format) {
 807                                 format = &stream->format[i];
 808                                 break;
 809                         }
 810                 }
 811                 if (format == NULL)
 812                         return -EINVAL;
 813
 814                 if (fsize->index >= format->nframes)
 815                         return -EINVAL;
 816
 817                 frame = &format->frame[fsize->index];
 818                 fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 819                 fsize->discrete.width = frame->wWidth;
 820                 fsize->discrete.height = frame->wHeight;
 821                 break;
 822         }
 823
 824         /* Frame interval enumeration */
 825         case VIDIOC_ENUM_FRAMEINTERVALS:
 826         {
 827                 struct v4l2_frmivalenum *fival = arg;
 828                 struct uvc_format *format = NULL;
 829                 struct uvc_frame *frame = NULL;
 830                 int i;
 831
 832                 /* Look for the given pixel format and frame size */
 833                 for (i = 0; i < stream->nformats; i++) {
 834                         if (stream->format[i].fcc ==
 835                                         fival->pixel_format) {
 836                                 format = &stream->format[i];
 837                                 break;
 838                         }
 839                 }
 840                 if (format == NULL)
 841                         return -EINVAL;
 842
 843                 for (i = 0; i < format->nframes; i++) {
 844                         if (format->frame[i].wWidth == fival->width &&
 845                             format->frame[i].wHeight == fival->height) {
 846                                 frame = &format->frame[i];
 847                                 break;
 848                         }
 849                 }
 850                 if (frame == NULL)
 851                         return -EINVAL;
 852
 853                 if (frame->bFrameIntervalType) {
 854                         if (fival->index >= frame->bFrameIntervalType)
 855                                 return -EINVAL;
 856
 857                         fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 858                         fival->discrete.numerator =
 859                                 frame->dwFrameInterval[fival->index];
 860                         fival->discrete.denominator = 10000000;
 861                         uvc_simplify_fraction(&fival->discrete.numerator,
 862                                 &fival->discrete.denominator, 8, 333);
 863                 } else {
 864                         fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
 865                         fival->stepwise.min.numerator =
 866                                 frame->dwFrameInterval[0];
 867                         fival->stepwise.min.denominator = 10000000;
 868                         fival->stepwise.max.numerator =
 869                                 frame->dwFrameInterval[1];
 870                         fival->stepwise.max.denominator = 10000000;
 871                         fival->stepwise.step.numerator =
 872                                 frame->dwFrameInterval[2];
 873                         fival->stepwise.step.denominator = 10000000;
 874                         uvc_simplify_fraction(&fival->stepwise.min.numerator,
 875                                 &fival->stepwise.min.denominator, 8, 333);
 876                         uvc_simplify_fraction(&fival->stepwise.max.numerator,
 877                                 &fival->stepwise.max.denominator, 8, 333);
 878                         uvc_simplify_fraction(&fival->stepwise.step.numerator,
 879                                 &fival->stepwise.step.denominator, 8, 333);
 880                 }
 881                 break;
 882         }
 883
 884         /* Get & Set streaming parameters */
 885         case VIDIOC_G_PARM:
 886                 return uvc_v4l2_get_streamparm(stream, arg);
 887
 888         case VIDIOC_S_PARM:
 889                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 890                         return ret;
 891
 892                 return uvc_v4l2_set_streamparm(stream, arg);
 893
 894         /* Cropping and scaling */
 895         case VIDIOC_CROPCAP:
 896         {
 897                 struct v4l2_cropcap *ccap = arg;
 898
 899                 if (ccap->type != stream->type)
 900                         return -EINVAL;
 901
 902                 ccap->bounds.left = 0;
 903                 ccap->bounds.top = 0;
 904
 905                 mutex_lock(&stream->mutex);
 906                 ccap->bounds.width = stream->cur_frame->wWidth;
 907                 ccap->bounds.height = stream->cur_frame->wHeight;
 908                 mutex_unlock(&stream->mutex);
 909
 910                 ccap->defrect = ccap->bounds;
 911
 912                 ccap->pixelaspect.numerator = 1;
 913                 ccap->pixelaspect.denominator = 1;
 914                 break;
 915         }
 916
 917         case VIDIOC_G_CROP:
 918         case VIDIOC_S_CROP:
 919                 return -EINVAL;
 920
 921         /* Buffers & streaming */
 922         case VIDIOC_REQBUFS:
 923                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 924                         return ret;
 925
 926                 mutex_lock(&stream->mutex);
 927                 ret = uvc_alloc_buffers(&stream->queue, arg);
 928                 mutex_unlock(&stream->mutex);
 929                 if (ret < 0)
 930                         return ret;
 931
 932                 if (ret == 0)
 933                         uvc_dismiss_privileges(handle);
 934
 935                 ret = 0;
 936                 break;
 937
 938         case VIDIOC_QUERYBUF:
 939         {
 940                 struct v4l2_buffer *buf = arg;
 941
 942                 if (!uvc_has_privileges(handle))
 943                         return -EBUSY;
 944
 945                 return uvc_query_buffer(&stream->queue, buf);
 946         }
 947
 948         case VIDIOC_QBUF:
 949                 if (!uvc_has_privileges(handle))
 950                         return -EBUSY;
 951
 952                 return uvc_queue_buffer(&stream->queue, arg);
 953
 954         case VIDIOC_DQBUF:
 955                 if (!uvc_has_privileges(handle))
 956                         return -EBUSY;
 957
 958                 return uvc_dequeue_buffer(&stream->queue, arg,
 959                         file->f_flags & O_NONBLOCK);
 960
 961         case VIDIOC_STREAMON:
 962         {
 963                 int *type = arg;
 964
 965                 if (*type != stream->type)
 966                         return -EINVAL;
 967
 968                 if (!uvc_has_privileges(handle))
 969                         return -EBUSY;
 970
 971                 mutex_lock(&stream->mutex);
 972                 ret = uvc_video_enable(stream, 1);
 973                 mutex_unlock(&stream->mutex);
 974                 if (ret < 0)
 975                         return ret;
 976                 break;
 977         }
 978
 979         case VIDIOC_STREAMOFF:
 980         {
 981                 int *type = arg;
 982
 983                 if (*type != stream->type)
 984                         return -EINVAL;
 985
 986                 if (!uvc_has_privileges(handle))
 987                         return -EBUSY;
 988
 989                 return uvc_video_enable(stream, 0);
 990         }
 991
 992         /* Analog video standards make no sense for digital cameras. */
 993         case VIDIOC_ENUMSTD:
 994         case VIDIOC_QUERYSTD:
 995         case VIDIOC_G_STD:
 996         case VIDIOC_S_STD:
 997
 998         case VIDIOC_OVERLAY:
 999
1000         case VIDIOC_ENUMAUDIO:
1001         case VIDIOC_ENUMAUDOUT:
1002
1003         case VIDIOC_ENUMOUTPUT:
1004                 uvc_trace(UVC_TRACE_IOCTL, "Unsupported ioctl 0x%08x\n", cmd);
1005                 return -EINVAL;
1006
1007         case UVCIOC_CTRL_MAP:
1008                 return uvc_ioctl_ctrl_map(chain, arg);
1009
1010         case UVCIOC_CTRL_QUERY:
1011                 return uvc_xu_ctrl_query(chain, arg);
1012
1013         default:
1014                 uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n", cmd);
1015                 return -EINVAL;
1016         }
1017
1018         return ret;
1019 }
1020
1021 static long uvc_v4l2_ioctl(struct file *file,
1022                      unsigned int cmd, unsigned long arg)
1023 {
1024         if (uvc_trace_param & UVC_TRACE_IOCTL) {
1025                 uvc_printk(KERN_DEBUG, "uvc_v4l2_ioctl(");
1026                 v4l_printk_ioctl(cmd);
1027                 printk(")\n");
1028         }
1029
1030         return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
1031 }
1032
1033 static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
1034                     size_t count, loff_t *ppos)
1035 {
1036         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
1037         return -EINVAL;
1038 }
1039
1040 static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
1041 {
1042         struct uvc_fh *handle = file->private_data;
1043         struct uvc_streaming *stream = handle->stream;
1044
1045         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");
1046
1047         return uvc_queue_mmap(&stream->queue, vma);
1048 }
1049
1050 static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
1051 {
1052         struct uvc_fh *handle = file->private_data;
1053         struct uvc_streaming *stream = handle->stream;
1054
1055         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");
1056
1057         return uvc_queue_poll(&stream->queue, file, wait);
1058 }
1059
1060 #ifndef CONFIG_MMU
1061 static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
1062                 unsigned long addr, unsigned long len, unsigned long pgoff,
1063                 unsigned long flags)
1064 {
1065         struct uvc_fh *handle = file->private_data;
1066         struct uvc_streaming *stream = handle->stream;
1067
1068         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
1069
1070         return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
1071 }
1072 #endif
1073
1074 const struct v4l2_file_operations uvc_fops = {
1075         .owner          = THIS_MODULE,
1076         .open           = uvc_v4l2_open,
1077         .release        = uvc_v4l2_release,
1078         .unlocked_ioctl = uvc_v4l2_ioctl,
1079         .read           = uvc_v4l2_read,
1080         .mmap           = uvc_v4l2_mmap,
1081         .poll           = uvc_v4l2_poll,
1082 #ifndef CONFIG_MMU
1083         .get_unmapped_area = uvc_v4l2_get_unmapped_area,
1084 #endif
1085 };
1086