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 <asm/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, int old)
  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                 if (old) {
  62                         uvc_trace(UVC_TRACE_CONTROL, "V4L2_CTRL_TYPE_MENU not "
  63                                   "supported for UVCIOC_CTRL_MAP_OLD.\n");
  64                         ret = -EINVAL;
  65                         goto done;
  66                 }
  67
  68                 size = xmap->menu_count * sizeof(*map->menu_info);
  69                 map->menu_info = kmalloc(size, GFP_KERNEL);
  70                 if (map->menu_info == NULL) {
  71                         ret = -ENOMEM;
  72                         goto done;
  73                 }
  74
  75                 if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
  76                         ret = -EFAULT;
  77                         goto done;
  78                 }
  79
  80                 map->menu_count = xmap->menu_count;
  81                 break;
  82
  83         default:
  84                 uvc_trace(UVC_TRACE_CONTROL, "Unsupported V4L2 control type "
  85                           "%u.\n", xmap->v4l2_type);
  86                 ret = -EINVAL;
  87                 goto done;
  88         }
  89
  90         ret = uvc_ctrl_add_mapping(chain, map);
  91
  92 done:
  93         kfree(map->menu_info);
  94         kfree(map);
  95
  96         return ret;
  97 }
  98
  99 /* ------------------------------------------------------------------------
 100  * V4L2 interface
 101  */
 102
 103 /*
 104  * Mapping V4L2 controls to UVC controls can be straighforward if done well.
 105  * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
 106  * must be grouped (for instance the Red Balance, Blue Balance and Do White
 107  * Balance V4L2 controls use the White Balance Component UVC control) or
 108  * otherwise translated. The approach we take here is to use a translation
 109  * table for the controls that can be mapped directly, and handle the others
 110  * manually.
 111  */
 112 static int uvc_v4l2_query_menu(struct uvc_video_chain *chain,
 113         struct v4l2_querymenu *query_menu)
 114 {
 115         struct uvc_menu_info *menu_info;
 116         struct uvc_control_mapping *mapping;
 117         struct uvc_control *ctrl;
 118         u32 index = query_menu->index;
 119         u32 id = query_menu->id;
 120
 121         ctrl = uvc_find_control(chain, query_menu->id, &mapping);
 122         if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
 123                 return -EINVAL;
 124
 125         if (query_menu->index >= mapping->menu_count)
 126                 return -EINVAL;
 127
 128         memset(query_menu, 0, sizeof(*query_menu));
 129         query_menu->id = id;
 130         query_menu->index = index;
 131
 132         menu_info = &mapping->menu_info[query_menu->index];
 133         strlcpy(query_menu->name, menu_info->name, sizeof query_menu->name);
 134         return 0;
 135 }
 136
 137 /*
 138  * Find the frame interval closest to the requested frame interval for the
 139  * given frame format and size. This should be done by the device as part of
 140  * the Video Probe and Commit negotiation, but some hardware don't implement
 141  * that feature.
 142  */
 143 static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
 144 {
 145         unsigned int i;
 146
 147         if (frame->bFrameIntervalType) {
 148                 __u32 best = -1, dist;
 149
 150                 for (i = 0; i < frame->bFrameIntervalType; ++i) {
 151                         dist = interval > frame->dwFrameInterval[i]
 152                              ? interval - frame->dwFrameInterval[i]
 153                              : frame->dwFrameInterval[i] - interval;
 154
 155                         if (dist > best)
 156                                 break;
 157
 158                         best = dist;
 159                 }
 160
 161                 interval = frame->dwFrameInterval[i-1];
 162         } else {
 163                 const __u32 min = frame->dwFrameInterval[0];
 164                 const __u32 max = frame->dwFrameInterval[1];
 165                 const __u32 step = frame->dwFrameInterval[2];
 166
 167                 interval = min + (interval - min + step/2) / step * step;
 168                 if (interval > max)
 169                         interval = max;
 170         }
 171
 172         return interval;
 173 }
 174
 175 static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 176         struct v4l2_format *fmt, struct uvc_streaming_control *probe,
 177         struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
 178 {
 179         struct uvc_format *format = NULL;
 180         struct uvc_frame *frame = NULL;
 181         __u16 rw, rh;
 182         unsigned int d, maxd;
 183         unsigned int i;
 184         __u32 interval;
 185         int ret = 0;
 186         __u8 *fcc;
 187
 188         if (fmt->type != stream->type)
 189                 return -EINVAL;
 190
 191         fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
 192         uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
 193                         fmt->fmt.pix.pixelformat,
 194                         fcc[0], fcc[1], fcc[2], fcc[3],
 195                         fmt->fmt.pix.width, fmt->fmt.pix.height);
 196
 197         /* Check if the hardware supports the requested format. */
 198         for (i = 0; i < stream->nformats; ++i) {
 199                 format = &stream->format[i];
 200                 if (format->fcc == fmt->fmt.pix.pixelformat)
 201                         break;
 202         }
 203
 204         if (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
 205                 uvc_trace(UVC_TRACE_FORMAT, "Unsupported format 0x%08x.\n",
 206                                 fmt->fmt.pix.pixelformat);
 207                 return -EINVAL;
 208         }
 209
 210         /* Find the closest image size. The distance between image sizes is
 211          * the size in pixels of the non-overlapping regions between the
 212          * requested size and the frame-specified size.
 213          */
 214         rw = fmt->fmt.pix.width;
 215         rh = fmt->fmt.pix.height;
 216         maxd = (unsigned int)-1;
 217
 218         for (i = 0; i < format->nframes; ++i) {
 219                 __u16 w = format->frame[i].wWidth;
 220                 __u16 h = format->frame[i].wHeight;
 221
 222                 d = min(w, rw) * min(h, rh);
 223                 d = w*h + rw*rh - 2*d;
 224                 if (d < maxd) {
 225                         maxd = d;
 226                         frame = &format->frame[i];
 227                 }
 228
 229                 if (maxd == 0)
 230                         break;
 231         }
 232
 233         if (frame == NULL) {
 234                 uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
 235                                 fmt->fmt.pix.width, fmt->fmt.pix.height);
 236                 return -EINVAL;
 237         }
 238
 239         /* Use the default frame interval. */
 240         interval = frame->dwDefaultFrameInterval;
 241         uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
 242                 "(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
 243                 (100000000/interval)%10);
 244
 245         /* Set the format index, frame index and frame interval. */
 246         memset(probe, 0, sizeof *probe);
 247         probe->bmHint = 1;      /* dwFrameInterval */
 248         probe->bFormatIndex = format->index;
 249         probe->bFrameIndex = frame->bFrameIndex;
 250         probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
 251         /* Some webcams stall the probe control set request when the
 252          * dwMaxVideoFrameSize field is set to zero. The UVC specification
 253          * clearly states that the field is read-only from the host, so this
 254          * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
 255          * the webcam to work around the problem.
 256          *
 257          * The workaround could probably be enabled for all webcams, so the
 258          * quirk can be removed if needed. It's currently useful to detect
 259          * webcam bugs and fix them before they hit the market (providing
 260          * developers test their webcams with the Linux driver as well as with
 261          * the Windows driver).
 262          */
 263         if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
 264                 probe->dwMaxVideoFrameSize =
 265                         stream->ctrl.dwMaxVideoFrameSize;
 266
 267         /* Probe the device. */
 268         ret = uvc_probe_video(stream, probe);
 269         if (ret < 0)
 270                 goto done;
 271
 272         fmt->fmt.pix.width = frame->wWidth;
 273         fmt->fmt.pix.height = frame->wHeight;
 274         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 275         fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
 276         fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
 277         fmt->fmt.pix.colorspace = format->colorspace;
 278         fmt->fmt.pix.priv = 0;
 279
 280         if (uvc_format != NULL)
 281                 *uvc_format = format;
 282         if (uvc_frame != NULL)
 283                 *uvc_frame = frame;
 284
 285 done:
 286         return ret;
 287 }
 288
 289 static int uvc_v4l2_get_format(struct uvc_streaming *stream,
 290         struct v4l2_format *fmt)
 291 {
 292         struct uvc_format *format = stream->cur_format;
 293         struct uvc_frame *frame = stream->cur_frame;
 294
 295         if (fmt->type != stream->type)
 296                 return -EINVAL;
 297
 298         if (format == NULL || frame == NULL)
 299                 return -EINVAL;
 300
 301         fmt->fmt.pix.pixelformat = format->fcc;
 302         fmt->fmt.pix.width = frame->wWidth;
 303         fmt->fmt.pix.height = frame->wHeight;
 304         fmt->fmt.pix.field = V4L2_FIELD_NONE;
 305         fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
 306         fmt->fmt.pix.sizeimage = stream->ctrl.dwMaxVideoFrameSize;
 307         fmt->fmt.pix.colorspace = format->colorspace;
 308         fmt->fmt.pix.priv = 0;
 309
 310         return 0;
 311 }
 312
 313 static int uvc_v4l2_set_format(struct uvc_streaming *stream,
 314         struct v4l2_format *fmt)
 315 {
 316         struct uvc_streaming_control probe;
 317         struct uvc_format *format;
 318         struct uvc_frame *frame;
 319         int ret;
 320
 321         if (fmt->type != stream->type)
 322                 return -EINVAL;
 323
 324         if (uvc_queue_allocated(&stream->queue))
 325                 return -EBUSY;
 326
 327         ret = uvc_v4l2_try_format(stream, fmt, &probe, &format, &frame);
 328         if (ret < 0)
 329                 return ret;
 330
 331         memcpy(&stream->ctrl, &probe, sizeof probe);
 332         stream->cur_format = format;
 333         stream->cur_frame = frame;
 334
 335         return 0;
 336 }
 337
 338 static int uvc_v4l2_get_streamparm(struct uvc_streaming *stream,
 339                 struct v4l2_streamparm *parm)
 340 {
 341         uint32_t numerator, denominator;
 342
 343         if (parm->type != stream->type)
 344                 return -EINVAL;
 345
 346         numerator = stream->ctrl.dwFrameInterval;
 347         denominator = 10000000;
 348         uvc_simplify_fraction(&numerator, &denominator, 8, 333);
 349
 350         memset(parm, 0, sizeof *parm);
 351         parm->type = stream->type;
 352
 353         if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
 354                 parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
 355                 parm->parm.capture.capturemode = 0;
 356                 parm->parm.capture.timeperframe.numerator = numerator;
 357                 parm->parm.capture.timeperframe.denominator = denominator;
 358                 parm->parm.capture.extendedmode = 0;
 359                 parm->parm.capture.readbuffers = 0;
 360         } else {
 361                 parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
 362                 parm->parm.output.outputmode = 0;
 363                 parm->parm.output.timeperframe.numerator = numerator;
 364                 parm->parm.output.timeperframe.denominator = denominator;
 365         }
 366
 367         return 0;
 368 }
 369
 370 static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
 371                 struct v4l2_streamparm *parm)
 372 {
 373         struct uvc_frame *frame = stream->cur_frame;
 374         struct uvc_streaming_control probe;
 375         struct v4l2_fract timeperframe;
 376         uint32_t interval;
 377         int ret;
 378
 379         if (parm->type != stream->type)
 380                 return -EINVAL;
 381
 382         if (uvc_queue_streaming(&stream->queue))
 383                 return -EBUSY;
 384
 385         if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 386                 timeperframe = parm->parm.capture.timeperframe;
 387         else
 388                 timeperframe = parm->parm.output.timeperframe;
 389
 390         memcpy(&probe, &stream->ctrl, sizeof probe);
 391         interval = uvc_fraction_to_interval(timeperframe.numerator,
 392                 timeperframe.denominator);
 393
 394         uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
 395                 timeperframe.numerator, timeperframe.denominator, interval);
 396         probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);
 397
 398         /* Probe the device with the new settings. */
 399         ret = uvc_probe_video(stream, &probe);
 400         if (ret < 0)
 401                 return ret;
 402
 403         memcpy(&stream->ctrl, &probe, sizeof probe);
 404
 405         /* Return the actual frame period. */
 406         timeperframe.numerator = probe.dwFrameInterval;
 407         timeperframe.denominator = 10000000;
 408         uvc_simplify_fraction(&timeperframe.numerator,
 409                 &timeperframe.denominator, 8, 333);
 410
 411         if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 412                 parm->parm.capture.timeperframe = timeperframe;
 413         else
 414                 parm->parm.output.timeperframe = timeperframe;
 415
 416         return 0;
 417 }
 418
 419 /* ------------------------------------------------------------------------
 420  * Privilege management
 421  */
 422
 423 /*
 424  * Privilege management is the multiple-open implementation basis. The current
 425  * implementation is completely transparent for the end-user and doesn't
 426  * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
 427  * Those ioctls enable finer control on the device (by making possible for a
 428  * user to request exclusive access to a device), but are not mature yet.
 429  * Switching to the V4L2 priority mechanism might be considered in the future
 430  * if this situation changes.
 431  *
 432  * Each open instance of a UVC device can either be in a privileged or
 433  * unprivileged state. Only a single instance can be in a privileged state at
 434  * a given time. Trying to perform an operation that requires privileges will
 435  * automatically acquire the required privileges if possible, or return -EBUSY
 436  * otherwise. Privileges are dismissed when closing the instance or when
 437  * freeing the video buffers using VIDIOC_REQBUFS.
 438  *
 439  * Operations that require privileges are:
 440  *
 441  * - VIDIOC_S_INPUT
 442  * - VIDIOC_S_PARM
 443  * - VIDIOC_S_FMT
 444  * - VIDIOC_REQBUFS
 445  */
 446 static int uvc_acquire_privileges(struct uvc_fh *handle)
 447 {
 448         /* Always succeed if the handle is already privileged. */
 449         if (handle->state == UVC_HANDLE_ACTIVE)
 450                 return 0;
 451
 452         /* Check if the device already has a privileged handle. */
 453         if (atomic_inc_return(&handle->stream->active) != 1) {
 454                 atomic_dec(&handle->stream->active);
 455                 return -EBUSY;
 456         }
 457
 458         handle->state = UVC_HANDLE_ACTIVE;
 459         return 0;
 460 }
 461
 462 static void uvc_dismiss_privileges(struct uvc_fh *handle)
 463 {
 464         if (handle->state == UVC_HANDLE_ACTIVE)
 465                 atomic_dec(&handle->stream->active);
 466
 467         handle->state = UVC_HANDLE_PASSIVE;
 468 }
 469
 470 static int uvc_has_privileges(struct uvc_fh *handle)
 471 {
 472         return handle->state == UVC_HANDLE_ACTIVE;
 473 }
 474
 475 /* ------------------------------------------------------------------------
 476  * V4L2 file operations
 477  */
 478
 479 static int uvc_v4l2_open(struct file *file)
 480 {
 481         struct uvc_streaming *stream;
 482         struct uvc_fh *handle;
 483         int ret = 0;
 484
 485         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
 486         stream = video_drvdata(file);
 487
 488         if (stream->dev->state & UVC_DEV_DISCONNECTED)
 489                 return -ENODEV;
 490
 491         ret = usb_autopm_get_interface(stream->dev->intf);
 492         if (ret < 0)
 493                 return ret;
 494
 495         /* Create the device handle. */
 496         handle = kzalloc(sizeof *handle, GFP_KERNEL);
 497         if (handle == NULL) {
 498                 usb_autopm_put_interface(stream->dev->intf);
 499                 return -ENOMEM;
 500         }
 501
 502         if (atomic_inc_return(&stream->dev->users) == 1) {
 503                 ret = uvc_status_start(stream->dev);
 504                 if (ret < 0) {
 505                         usb_autopm_put_interface(stream->dev->intf);
 506                         atomic_dec(&stream->dev->users);
 507                         kfree(handle);
 508                         return ret;
 509                 }
 510         }
 511
 512         handle->chain = stream->chain;
 513         handle->stream = stream;
 514         handle->state = UVC_HANDLE_PASSIVE;
 515         file->private_data = handle;
 516
 517         return 0;
 518 }
 519
 520 static int uvc_v4l2_release(struct file *file)
 521 {
 522         struct uvc_fh *handle = file->private_data;
 523         struct uvc_streaming *stream = handle->stream;
 524
 525         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");
 526
 527         /* Only free resources if this is a privileged handle. */
 528         if (uvc_has_privileges(handle)) {
 529                 uvc_video_enable(stream, 0);
 530
 531                 mutex_lock(&stream->queue.mutex);
 532                 if (uvc_free_buffers(&stream->queue) < 0)
 533                         uvc_printk(KERN_ERR, "uvc_v4l2_release: Unable to "
 534                                         "free buffers.\n");
 535                 mutex_unlock(&stream->queue.mutex);
 536         }
 537
 538         /* Release the file handle. */
 539         uvc_dismiss_privileges(handle);
 540         kfree(handle);
 541         file->private_data = NULL;
 542
 543         if (atomic_dec_return(&stream->dev->users) == 0)
 544                 uvc_status_stop(stream->dev);
 545
 546         usb_autopm_put_interface(stream->dev->intf);
 547         return 0;
 548 }
 549
 550 static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 551 {
 552         struct video_device *vdev = video_devdata(file);
 553         struct uvc_fh *handle = file->private_data;
 554         struct uvc_video_chain *chain = handle->chain;
 555         struct uvc_streaming *stream = handle->stream;
 556         long ret = 0;
 557
 558         switch (cmd) {
 559         /* Query capabilities */
 560         case VIDIOC_QUERYCAP:
 561         {
 562                 struct v4l2_capability *cap = arg;
 563
 564                 memset(cap, 0, sizeof *cap);
 565                 strlcpy(cap->driver, "uvcvideo", sizeof cap->driver);
 566                 strlcpy(cap->card, vdev->name, sizeof cap->card);
 567                 usb_make_path(stream->dev->udev,
 568                               cap->bus_info, sizeof(cap->bus_info));
 569                 cap->version = DRIVER_VERSION_NUMBER;
 570                 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 571                         cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
 572                                           | V4L2_CAP_STREAMING;
 573                 else
 574                         cap->capabilities = V4L2_CAP_VIDEO_OUTPUT
 575                                           | V4L2_CAP_STREAMING;
 576                 break;
 577         }
 578
 579         /* Get, Set & Query control */
 580         case VIDIOC_QUERYCTRL:
 581                 return uvc_query_v4l2_ctrl(chain, arg);
 582
 583         case VIDIOC_G_CTRL:
 584         {
 585                 struct v4l2_control *ctrl = arg;
 586                 struct v4l2_ext_control xctrl;
 587
 588                 memset(&xctrl, 0, sizeof xctrl);
 589                 xctrl.id = ctrl->id;
 590
 591                 ret = uvc_ctrl_begin(chain);
 592                 if (ret < 0)
 593                         return ret;
 594
 595                 ret = uvc_ctrl_get(chain, &xctrl);
 596                 uvc_ctrl_rollback(chain);
 597                 if (ret >= 0)
 598                         ctrl->value = xctrl.value;
 599                 break;
 600         }
 601
 602         case VIDIOC_S_CTRL:
 603         {
 604                 struct v4l2_control *ctrl = arg;
 605                 struct v4l2_ext_control xctrl;
 606
 607                 memset(&xctrl, 0, sizeof xctrl);
 608                 xctrl.id = ctrl->id;
 609                 xctrl.value = ctrl->value;
 610
 611                 ret = uvc_ctrl_begin(chain);
 612                 if (ret < 0)
 613                         return ret;
 614
 615                 ret = uvc_ctrl_set(chain, &xctrl);
 616                 if (ret < 0) {
 617                         uvc_ctrl_rollback(chain);
 618                         return ret;
 619                 }
 620                 ret = uvc_ctrl_commit(chain);
 621                 if (ret == 0)
 622                         ctrl->value = xctrl.value;
 623                 break;
 624         }
 625
 626         case VIDIOC_QUERYMENU:
 627                 return uvc_v4l2_query_menu(chain, arg);
 628
 629         case VIDIOC_G_EXT_CTRLS:
 630         {
 631                 struct v4l2_ext_controls *ctrls = arg;
 632                 struct v4l2_ext_control *ctrl = ctrls->controls;
 633                 unsigned int i;
 634
 635                 ret = uvc_ctrl_begin(chain);
 636                 if (ret < 0)
 637                         return ret;
 638
 639                 for (i = 0; i < ctrls->count; ++ctrl, ++i) {
 640                         ret = uvc_ctrl_get(chain, ctrl);
 641                         if (ret < 0) {
 642                                 uvc_ctrl_rollback(chain);
 643                                 ctrls->error_idx = i;
 644                                 return ret;
 645                         }
 646                 }
 647                 ctrls->error_idx = 0;
 648                 ret = uvc_ctrl_rollback(chain);
 649                 break;
 650         }
 651
 652         case VIDIOC_S_EXT_CTRLS:
 653         case VIDIOC_TRY_EXT_CTRLS:
 654         {
 655                 struct v4l2_ext_controls *ctrls = arg;
 656                 struct v4l2_ext_control *ctrl = ctrls->controls;
 657                 unsigned int i;
 658
 659                 ret = uvc_ctrl_begin(chain);
 660                 if (ret < 0)
 661                         return ret;
 662
 663                 for (i = 0; i < ctrls->count; ++ctrl, ++i) {
 664                         ret = uvc_ctrl_set(chain, ctrl);
 665                         if (ret < 0) {
 666                                 uvc_ctrl_rollback(chain);
 667                                 ctrls->error_idx = i;
 668                                 return ret;
 669                         }
 670                 }
 671
 672                 ctrls->error_idx = 0;
 673
 674                 if (cmd == VIDIOC_S_EXT_CTRLS)
 675                         ret = uvc_ctrl_commit(chain);
 676                 else
 677                         ret = uvc_ctrl_rollback(chain);
 678                 break;
 679         }
 680
 681         /* Get, Set & Enum input */
 682         case VIDIOC_ENUMINPUT:
 683         {
 684                 const struct uvc_entity *selector = chain->selector;
 685                 struct v4l2_input *input = arg;
 686                 struct uvc_entity *iterm = NULL;
 687                 u32 index = input->index;
 688                 int pin = 0;
 689
 690                 if (selector == NULL ||
 691                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 692                         if (index != 0)
 693                                 return -EINVAL;
 694                         list_for_each_entry(iterm, &chain->entities, chain) {
 695                                 if (UVC_ENTITY_IS_ITERM(iterm))
 696                                         break;
 697                         }
 698                         pin = iterm->id;
 699                 } else if (pin < selector->bNrInPins) {
 700                         pin = selector->baSourceID[index];
 701                         list_for_each_entry(iterm, &chain->entities, chain) {
 702                                 if (!UVC_ENTITY_IS_ITERM(iterm))
 703                                         continue;
 704                                 if (iterm->id == pin)
 705                                         break;
 706                         }
 707                 }
 708
 709                 if (iterm == NULL || iterm->id != pin)
 710                         return -EINVAL;
 711
 712                 memset(input, 0, sizeof *input);
 713                 input->index = index;
 714                 strlcpy(input->name, iterm->name, sizeof input->name);
 715                 if (UVC_ENTITY_TYPE(iterm) == UVC_ITT_CAMERA)
 716                         input->type = V4L2_INPUT_TYPE_CAMERA;
 717                 break;
 718         }
 719
 720         case VIDIOC_G_INPUT:
 721         {
 722                 u8 input;
 723
 724                 if (chain->selector == NULL ||
 725                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 726                         *(int *)arg = 0;
 727                         break;
 728                 }
 729
 730                 ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
 731                         chain->selector->id, chain->dev->intfnum,
 732                         UVC_SU_INPUT_SELECT_CONTROL, &input, 1);
 733                 if (ret < 0)
 734                         return ret;
 735
 736                 *(int *)arg = input - 1;
 737                 break;
 738         }
 739
 740         case VIDIOC_S_INPUT:
 741         {
 742                 u32 input = *(u32 *)arg + 1;
 743
 744                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 745                         return ret;
 746
 747                 if (chain->selector == NULL ||
 748                     (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 749                         if (input != 1)
 750                                 return -EINVAL;
 751                         break;
 752                 }
 753
 754                 if (input == 0 || input > chain->selector->bNrInPins)
 755                         return -EINVAL;
 756
 757                 return uvc_query_ctrl(chain->dev, UVC_SET_CUR,
 758                         chain->selector->id, chain->dev->intfnum,
 759                         UVC_SU_INPUT_SELECT_CONTROL, &input, 1);
 760         }
 761
 762         /* Try, Get, Set & Enum format */
 763         case VIDIOC_ENUM_FMT:
 764         {
 765                 struct v4l2_fmtdesc *fmt = arg;
 766                 struct uvc_format *format;
 767                 enum v4l2_buf_type type = fmt->type;
 768                 __u32 index = fmt->index;
 769
 770                 if (fmt->type != stream->type ||
 771                     fmt->index >= stream->nformats)
 772                         return -EINVAL;
 773
 774                 memset(fmt, 0, sizeof(*fmt));
 775                 fmt->index = index;
 776                 fmt->type = type;
 777
 778                 format = &stream->format[fmt->index];
 779                 fmt->flags = 0;
 780                 if (format->flags & UVC_FMT_FLAG_COMPRESSED)
 781                         fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
 782                 strlcpy(fmt->description, format->name,
 783                         sizeof fmt->description);
 784                 fmt->description[sizeof fmt->description - 1] = 0;
 785                 fmt->pixelformat = format->fcc;
 786                 break;
 787         }
 788
 789         case VIDIOC_TRY_FMT:
 790         {
 791                 struct uvc_streaming_control probe;
 792
 793                 return uvc_v4l2_try_format(stream, arg, &probe, NULL, NULL);
 794         }
 795
 796         case VIDIOC_S_FMT:
 797                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 798                         return ret;
 799
 800                 return uvc_v4l2_set_format(stream, arg);
 801
 802         case VIDIOC_G_FMT:
 803                 return uvc_v4l2_get_format(stream, arg);
 804
 805         /* Frame size enumeration */
 806         case VIDIOC_ENUM_FRAMESIZES:
 807         {
 808                 struct v4l2_frmsizeenum *fsize = arg;
 809                 struct uvc_format *format = NULL;
 810                 struct uvc_frame *frame;
 811                 int i;
 812
 813                 /* Look for the given pixel format */
 814                 for (i = 0; i < stream->nformats; i++) {
 815                         if (stream->format[i].fcc ==
 816                                         fsize->pixel_format) {
 817                                 format = &stream->format[i];
 818                                 break;
 819                         }
 820                 }
 821                 if (format == NULL)
 822                         return -EINVAL;
 823
 824                 if (fsize->index >= format->nframes)
 825                         return -EINVAL;
 826
 827                 frame = &format->frame[fsize->index];
 828                 fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 829                 fsize->discrete.width = frame->wWidth;
 830                 fsize->discrete.height = frame->wHeight;
 831                 break;
 832         }
 833
 834         /* Frame interval enumeration */
 835         case VIDIOC_ENUM_FRAMEINTERVALS:
 836         {
 837                 struct v4l2_frmivalenum *fival = arg;
 838                 struct uvc_format *format = NULL;
 839                 struct uvc_frame *frame = NULL;
 840                 int i;
 841
 842                 /* Look for the given pixel format and frame size */
 843                 for (i = 0; i < stream->nformats; i++) {
 844                         if (stream->format[i].fcc ==
 845                                         fival->pixel_format) {
 846                                 format = &stream->format[i];
 847                                 break;
 848                         }
 849                 }
 850                 if (format == NULL)
 851                         return -EINVAL;
 852
 853                 for (i = 0; i < format->nframes; i++) {
 854                         if (format->frame[i].wWidth == fival->width &&
 855                             format->frame[i].wHeight == fival->height) {
 856                                 frame = &format->frame[i];
 857                                 break;
 858                         }
 859                 }
 860                 if (frame == NULL)
 861                         return -EINVAL;
 862
 863                 if (frame->bFrameIntervalType) {
 864                         if (fival->index >= frame->bFrameIntervalType)
 865                                 return -EINVAL;
 866
 867                         fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 868                         fival->discrete.numerator =
 869                                 frame->dwFrameInterval[fival->index];
 870                         fival->discrete.denominator = 10000000;
 871                         uvc_simplify_fraction(&fival->discrete.numerator,
 872                                 &fival->discrete.denominator, 8, 333);
 873                 } else {
 874                         fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
 875                         fival->stepwise.min.numerator =
 876                                 frame->dwFrameInterval[0];
 877                         fival->stepwise.min.denominator = 10000000;
 878                         fival->stepwise.max.numerator =
 879                                 frame->dwFrameInterval[1];
 880                         fival->stepwise.max.denominator = 10000000;
 881                         fival->stepwise.step.numerator =
 882                                 frame->dwFrameInterval[2];
 883                         fival->stepwise.step.denominator = 10000000;
 884                         uvc_simplify_fraction(&fival->stepwise.min.numerator,
 885                                 &fival->stepwise.min.denominator, 8, 333);
 886                         uvc_simplify_fraction(&fival->stepwise.max.numerator,
 887                                 &fival->stepwise.max.denominator, 8, 333);
 888                         uvc_simplify_fraction(&fival->stepwise.step.numerator,
 889                                 &fival->stepwise.step.denominator, 8, 333);
 890                 }
 891                 break;
 892         }
 893
 894         /* Get & Set streaming parameters */
 895         case VIDIOC_G_PARM:
 896                 return uvc_v4l2_get_streamparm(stream, arg);
 897
 898         case VIDIOC_S_PARM:
 899                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 900                         return ret;
 901
 902                 return uvc_v4l2_set_streamparm(stream, arg);
 903
 904         /* Cropping and scaling */
 905         case VIDIOC_CROPCAP:
 906         {
 907                 struct v4l2_cropcap *ccap = arg;
 908                 struct uvc_frame *frame = stream->cur_frame;
 909
 910                 if (ccap->type != stream->type)
 911                         return -EINVAL;
 912
 913                 ccap->bounds.left = 0;
 914                 ccap->bounds.top = 0;
 915                 ccap->bounds.width = frame->wWidth;
 916                 ccap->bounds.height = frame->wHeight;
 917
 918                 ccap->defrect = ccap->bounds;
 919
 920                 ccap->pixelaspect.numerator = 1;
 921                 ccap->pixelaspect.denominator = 1;
 922                 break;
 923         }
 924
 925         case VIDIOC_G_CROP:
 926         case VIDIOC_S_CROP:
 927                 return -EINVAL;
 928
 929         /* Buffers & streaming */
 930         case VIDIOC_REQBUFS:
 931         {
 932                 struct v4l2_requestbuffers *rb = arg;
 933                 unsigned int bufsize =
 934                         stream->ctrl.dwMaxVideoFrameSize;
 935
 936                 if (rb->type != stream->type ||
 937                     rb->memory != V4L2_MEMORY_MMAP)
 938                         return -EINVAL;
 939
 940                 if ((ret = uvc_acquire_privileges(handle)) < 0)
 941                         return ret;
 942
 943                 ret = uvc_alloc_buffers(&stream->queue, rb->count, bufsize);
 944                 if (ret < 0)
 945                         return ret;
 946
 947                 if (ret == 0)
 948                         uvc_dismiss_privileges(handle);
 949
 950                 rb->count = ret;
 951                 ret = 0;
 952                 break;
 953         }
 954
 955         case VIDIOC_QUERYBUF:
 956         {
 957                 struct v4l2_buffer *buf = arg;
 958
 959                 if (buf->type != stream->type)
 960                         return -EINVAL;
 961
 962                 if (!uvc_has_privileges(handle))
 963                         return -EBUSY;
 964
 965                 return uvc_query_buffer(&stream->queue, buf);
 966         }
 967
 968         case VIDIOC_QBUF:
 969                 if (!uvc_has_privileges(handle))
 970                         return -EBUSY;
 971
 972                 return uvc_queue_buffer(&stream->queue, arg);
 973
 974         case VIDIOC_DQBUF:
 975                 if (!uvc_has_privileges(handle))
 976                         return -EBUSY;
 977
 978                 return uvc_dequeue_buffer(&stream->queue, arg,
 979                         file->f_flags & O_NONBLOCK);
 980
 981         case VIDIOC_STREAMON:
 982         {
 983                 int *type = arg;
 984
 985                 if (*type != stream->type)
 986                         return -EINVAL;
 987
 988                 if (!uvc_has_privileges(handle))
 989                         return -EBUSY;
 990
 991                 ret = uvc_video_enable(stream, 1);
 992                 if (ret < 0)
 993                         return ret;
 994                 break;
 995         }
 996
 997         case VIDIOC_STREAMOFF:
 998         {
 999                 int *type = arg;
1000
1001                 if (*type != stream->type)
1002                         return -EINVAL;
1003
1004                 if (!uvc_has_privileges(handle))
1005                         return -EBUSY;
1006
1007                 return uvc_video_enable(stream, 0);
1008         }
1009
1010         /* Analog video standards make no sense for digital cameras. */
1011         case VIDIOC_ENUMSTD:
1012         case VIDIOC_QUERYSTD:
1013         case VIDIOC_G_STD:
1014         case VIDIOC_S_STD:
1015
1016         case VIDIOC_OVERLAY:
1017
1018         case VIDIOC_ENUMAUDIO:
1019         case VIDIOC_ENUMAUDOUT:
1020
1021         case VIDIOC_ENUMOUTPUT:
1022                 uvc_trace(UVC_TRACE_IOCTL, "Unsupported ioctl 0x%08x\n", cmd);
1023                 return -EINVAL;
1024
1025         /* Dynamic controls. */
1026         case UVCIOC_CTRL_ADD:
1027                 /* Legacy ioctl, kept for API compatibility reasons */
1028                 return -EEXIST;
1029
1030         case UVCIOC_CTRL_MAP_OLD:
1031         case UVCIOC_CTRL_MAP:
1032                 return uvc_ioctl_ctrl_map(chain, arg,
1033                                           cmd == UVCIOC_CTRL_MAP_OLD);
1034
1035         case UVCIOC_CTRL_GET:
1036                 return uvc_xu_ctrl_query(chain, arg, 0);
1037
1038         case UVCIOC_CTRL_SET:
1039                 return uvc_xu_ctrl_query(chain, arg, 1);
1040
1041         default:
1042                 if ((ret = v4l_compat_translate_ioctl(file, cmd, arg,
1043                         uvc_v4l2_do_ioctl)) == -ENOIOCTLCMD)
1044                         uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n",
1045                                   cmd);
1046                 return ret;
1047         }
1048
1049         return ret;
1050 }
1051
1052 static long uvc_v4l2_ioctl(struct file *file,
1053                      unsigned int cmd, unsigned long arg)
1054 {
1055         if (uvc_trace_param & UVC_TRACE_IOCTL) {
1056                 uvc_printk(KERN_DEBUG, "uvc_v4l2_ioctl(");
1057                 v4l_printk_ioctl(cmd);
1058                 printk(")\n");
1059         }
1060
1061         return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
1062 }
1063
1064 static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
1065                     size_t count, loff_t *ppos)
1066 {
1067         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
1068         return -EINVAL;
1069 }
1070
1071 /*
1072  * VMA operations.
1073  */
1074 static void uvc_vm_open(struct vm_area_struct *vma)
1075 {
1076         struct uvc_buffer *buffer = vma->vm_private_data;
1077         buffer->vma_use_count++;
1078 }
1079
1080 static void uvc_vm_close(struct vm_area_struct *vma)
1081 {
1082         struct uvc_buffer *buffer = vma->vm_private_data;
1083         buffer->vma_use_count--;
1084 }
1085
1086 static const struct vm_operations_struct uvc_vm_ops = {
1087         .open           = uvc_vm_open,
1088         .close          = uvc_vm_close,
1089 };
1090
1091 static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
1092 {
1093         struct uvc_fh *handle = file->private_data;
1094         struct uvc_streaming *stream = handle->stream;
1095         struct uvc_video_queue *queue = &stream->queue;
1096         struct uvc_buffer *uninitialized_var(buffer);
1097         struct page *page;
1098         unsigned long addr, start, size;
1099         unsigned int i;
1100         int ret = 0;
1101
1102         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");
1103
1104         start = vma->vm_start;
1105         size = vma->vm_end - vma->vm_start;
1106
1107         mutex_lock(&queue->mutex);
1108
1109         for (i = 0; i < queue->count; ++i) {
1110                 buffer = &queue->buffer[i];
1111                 if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
1112                         break;
1113         }
1114
1115         if (i == queue->count || size != queue->buf_size) {
1116                 ret = -EINVAL;
1117                 goto done;
1118         }
1119
1120         /*
1121          * VM_IO marks the area as being an mmaped region for I/O to a
1122          * device. It also prevents the region from being core dumped.
1123          */
1124         vma->vm_flags |= VM_IO;
1125
1126         addr = (unsigned long)queue->mem + buffer->buf.m.offset;
1127         while (size > 0) {
1128                 page = vmalloc_to_page((void *)addr);
1129                 if ((ret = vm_insert_page(vma, start, page)) < 0)
1130                         goto done;
1131
1132                 start += PAGE_SIZE;
1133                 addr += PAGE_SIZE;
1134                 size -= PAGE_SIZE;
1135         }
1136
1137         vma->vm_ops = &uvc_vm_ops;
1138         vma->vm_private_data = buffer;
1139         uvc_vm_open(vma);
1140
1141 done:
1142         mutex_unlock(&queue->mutex);
1143         return ret;
1144 }
1145
1146 static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
1147 {
1148         struct uvc_fh *handle = file->private_data;
1149         struct uvc_streaming *stream = handle->stream;
1150
1151         uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");
1152
1153         return uvc_queue_poll(&stream->queue, file, wait);
1154 }
1155
1156 const struct v4l2_file_operations uvc_fops = {
1157         .owner          = THIS_MODULE,
1158         .open           = uvc_v4l2_open,
1159         .release        = uvc_v4l2_release,
1160         .ioctl          = uvc_v4l2_ioctl,
1161         .read           = uvc_v4l2_read,
1162         .mmap           = uvc_v4l2_mmap,
1163         .poll           = uvc_v4l2_poll,
1164 };
1165