drivers/media/platform/vsp1/vsp1_histo.c

   1 /*
   2  * vsp1_histo.c  --  R-Car VSP1 Histogram API
   3  *
   4  * Copyright (C) 2016 Renesas Electronics Corporation
   5  * Copyright (C) 2016 Laurent Pinchart
   6  *
   7  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/gfp.h>
  17
  18 #include <media/v4l2-ioctl.h>
  19 #include <media/v4l2-subdev.h>
  20 #include <media/videobuf2-vmalloc.h>
  21
  22 #include "vsp1.h"
  23 #include "vsp1_histo.h"
  24 #include "vsp1_pipe.h"
  25
  26 #define HISTO_MIN_SIZE                          4U
  27 #define HISTO_MAX_SIZE                          8192U
  28
  29 /* -----------------------------------------------------------------------------
  30  * Buffer Operations
  31  */
  32
  33 static inline struct vsp1_histogram_buffer *
  34 to_vsp1_histogram_buffer(struct vb2_v4l2_buffer *vbuf)
  35 {
  36         return container_of(vbuf, struct vsp1_histogram_buffer, buf);
  37 }
  38
  39 struct vsp1_histogram_buffer *
  40 vsp1_histogram_buffer_get(struct vsp1_histogram *histo)
  41 {
  42         struct vsp1_histogram_buffer *buf = NULL;
  43         unsigned long flags;
  44
  45         spin_lock_irqsave(&histo->irqlock, flags);
  46
  47         if (list_empty(&histo->irqqueue))
  48                 goto done;
  49
  50         buf = list_first_entry(&histo->irqqueue, struct vsp1_histogram_buffer,
  51                                queue);
  52         list_del(&buf->queue);
  53         histo->readout = true;
  54
  55 done:
  56         spin_unlock_irqrestore(&histo->irqlock, flags);
  57         return buf;
  58 }
  59
  60 void vsp1_histogram_buffer_complete(struct vsp1_histogram *histo,
  61                                     struct vsp1_histogram_buffer *buf,
  62                                     size_t size)
  63 {
  64         struct vsp1_pipeline *pipe = histo->pipe;
  65         unsigned long flags;
  66
  67         /*
  68          * The pipeline pointer is guaranteed to be valid as this function is
  69          * called from the frame completion interrupt handler, which can only
  70          * occur when video streaming is active.
  71          */
  72         buf->buf.sequence = pipe->sequence;
  73         buf->buf.vb2_buf.timestamp = ktime_get_ns();
  74         vb2_set_plane_payload(&buf->buf.vb2_buf, 0, size);
  75         vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
  76
  77         spin_lock_irqsave(&histo->irqlock, flags);
  78         histo->readout = false;
  79         wake_up(&histo->wait_queue);
  80         spin_unlock_irqrestore(&histo->irqlock, flags);
  81 }
  82
  83 /* -----------------------------------------------------------------------------
  84  * videobuf2 Queue Operations
  85  */
  86
  87 static int histo_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
  88                              unsigned int *nplanes, unsigned int sizes[],
  89                              struct device *alloc_devs[])
  90 {
  91         struct vsp1_histogram *histo = vb2_get_drv_priv(vq);
  92
  93         if (*nplanes) {
  94                 if (*nplanes != 1)
  95                         return -EINVAL;
  96
  97                 if (sizes[0] < histo->data_size)
  98                         return -EINVAL;
  99
 100                 return 0;
 101         }
 102
 103         *nplanes = 1;
 104         sizes[0] = histo->data_size;
 105
 106         return 0;
 107 }
 108
 109 static int histo_buffer_prepare(struct vb2_buffer *vb)
 110 {
 111         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 112         struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
 113         struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);
 114
 115         if (vb->num_planes != 1)
 116                 return -EINVAL;
 117
 118         if (vb2_plane_size(vb, 0) < histo->data_size)
 119                 return -EINVAL;
 120
 121         buf->addr = vb2_plane_vaddr(vb, 0);
 122
 123         return 0;
 124 }
 125
 126 static void histo_buffer_queue(struct vb2_buffer *vb)
 127 {
 128         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 129         struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
 130         struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);
 131         unsigned long flags;
 132
 133         spin_lock_irqsave(&histo->irqlock, flags);
 134         list_add_tail(&buf->queue, &histo->irqqueue);
 135         spin_unlock_irqrestore(&histo->irqlock, flags);
 136 }
 137
 138 static int histo_start_streaming(struct vb2_queue *vq, unsigned int count)
 139 {
 140         return 0;
 141 }
 142
 143 static void histo_stop_streaming(struct vb2_queue *vq)
 144 {
 145         struct vsp1_histogram *histo = vb2_get_drv_priv(vq);
 146         struct vsp1_histogram_buffer *buffer;
 147         unsigned long flags;
 148
 149         spin_lock_irqsave(&histo->irqlock, flags);
 150
 151         /* Remove all buffers from the IRQ queue. */
 152         list_for_each_entry(buffer, &histo->irqqueue, queue)
 153                 vb2_buffer_done(&buffer->buf.vb2_buf, VB2_BUF_STATE_ERROR);
 154         INIT_LIST_HEAD(&histo->irqqueue);
 155
 156         /* Wait for the buffer being read out (if any) to complete. */
 157         wait_event_lock_irq(histo->wait_queue, !histo->readout, histo->irqlock);
 158
 159         spin_unlock_irqrestore(&histo->irqlock, flags);
 160 }
 161
 162 static const struct vb2_ops histo_video_queue_qops = {
 163         .queue_setup = histo_queue_setup,
 164         .buf_prepare = histo_buffer_prepare,
 165         .buf_queue = histo_buffer_queue,
 166         .wait_prepare = vb2_ops_wait_prepare,
 167         .wait_finish = vb2_ops_wait_finish,
 168         .start_streaming = histo_start_streaming,
 169         .stop_streaming = histo_stop_streaming,
 170 };
 171
 172 /* -----------------------------------------------------------------------------
 173  * V4L2 Subdevice Operations
 174  */
 175
 176 static int histo_enum_mbus_code(struct v4l2_subdev *subdev,
 177                                 struct v4l2_subdev_pad_config *cfg,
 178                                 struct v4l2_subdev_mbus_code_enum *code)
 179 {
 180         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 181
 182         if (code->pad == HISTO_PAD_SOURCE) {
 183                 code->code = MEDIA_BUS_FMT_FIXED;
 184                 return 0;
 185         }
 186
 187         return vsp1_subdev_enum_mbus_code(subdev, cfg, code, histo->formats,
 188                                           histo->num_formats);
 189 }
 190
 191 static int histo_enum_frame_size(struct v4l2_subdev *subdev,
 192                                  struct v4l2_subdev_pad_config *cfg,
 193                                  struct v4l2_subdev_frame_size_enum *fse)
 194 {
 195         if (fse->pad != HISTO_PAD_SINK)
 196                 return -EINVAL;
 197
 198         return vsp1_subdev_enum_frame_size(subdev, cfg, fse, HISTO_MIN_SIZE,
 199                                            HISTO_MIN_SIZE, HISTO_MAX_SIZE,
 200                                            HISTO_MAX_SIZE);
 201 }
 202
 203 static int histo_get_selection(struct v4l2_subdev *subdev,
 204                                struct v4l2_subdev_pad_config *cfg,
 205                                struct v4l2_subdev_selection *sel)
 206 {
 207         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 208         struct v4l2_subdev_pad_config *config;
 209         struct v4l2_mbus_framefmt *format;
 210         struct v4l2_rect *crop;
 211         int ret = 0;
 212
 213         if (sel->pad != HISTO_PAD_SINK)
 214                 return -EINVAL;
 215
 216         mutex_lock(&histo->entity.lock);
 217
 218         config = vsp1_entity_get_pad_config(&histo->entity, cfg, sel->which);
 219         if (!config) {
 220                 ret = -EINVAL;
 221                 goto done;
 222         }
 223
 224         switch (sel->target) {
 225         case V4L2_SEL_TGT_COMPOSE_BOUNDS:
 226         case V4L2_SEL_TGT_COMPOSE_DEFAULT:
 227                 crop = vsp1_entity_get_pad_selection(&histo->entity, config,
 228                                                      HISTO_PAD_SINK,
 229                                                      V4L2_SEL_TGT_CROP);
 230                 sel->r.left = 0;
 231                 sel->r.top = 0;
 232                 sel->r.width = crop->width;
 233                 sel->r.height = crop->height;
 234                 break;
 235
 236         case V4L2_SEL_TGT_CROP_BOUNDS:
 237         case V4L2_SEL_TGT_CROP_DEFAULT:
 238                 format = vsp1_entity_get_pad_format(&histo->entity, config,
 239                                                     HISTO_PAD_SINK);
 240                 sel->r.left = 0;
 241                 sel->r.top = 0;
 242                 sel->r.width = format->width;
 243                 sel->r.height = format->height;
 244                 break;
 245
 246         case V4L2_SEL_TGT_COMPOSE:
 247         case V4L2_SEL_TGT_CROP:
 248                 sel->r = *vsp1_entity_get_pad_selection(&histo->entity, config,
 249                                                         sel->pad, sel->target);
 250                 break;
 251
 252         default:
 253                 ret = -EINVAL;
 254                 break;
 255         }
 256
 257 done:
 258         mutex_unlock(&histo->entity.lock);
 259         return ret;
 260 }
 261
 262 static int histo_set_crop(struct v4l2_subdev *subdev,
 263                           struct v4l2_subdev_pad_config *config,
 264                          struct v4l2_subdev_selection *sel)
 265 {
 266         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 267         struct v4l2_mbus_framefmt *format;
 268         struct v4l2_rect *selection;
 269
 270         /* The crop rectangle must be inside the input frame. */
 271         format = vsp1_entity_get_pad_format(&histo->entity, config,
 272                                             HISTO_PAD_SINK);
 273         sel->r.left = clamp_t(unsigned int, sel->r.left, 0, format->width - 1);
 274         sel->r.top = clamp_t(unsigned int, sel->r.top, 0, format->height - 1);
 275         sel->r.width = clamp_t(unsigned int, sel->r.width, HISTO_MIN_SIZE,
 276                                format->width - sel->r.left);
 277         sel->r.height = clamp_t(unsigned int, sel->r.height, HISTO_MIN_SIZE,
 278                                 format->height - sel->r.top);
 279
 280         /* Set the crop rectangle and reset the compose rectangle. */
 281         selection = vsp1_entity_get_pad_selection(&histo->entity, config,
 282                                                   sel->pad, V4L2_SEL_TGT_CROP);
 283         *selection = sel->r;
 284
 285         selection = vsp1_entity_get_pad_selection(&histo->entity, config,
 286                                                   sel->pad,
 287                                                   V4L2_SEL_TGT_COMPOSE);
 288         *selection = sel->r;
 289
 290         return 0;
 291 }
 292
 293 static int histo_set_compose(struct v4l2_subdev *subdev,
 294                              struct v4l2_subdev_pad_config *config,
 295                              struct v4l2_subdev_selection *sel)
 296 {
 297         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 298         struct v4l2_rect *compose;
 299         struct v4l2_rect *crop;
 300         unsigned int ratio;
 301
 302         /*
 303          * The compose rectangle is used to configure downscaling, the top left
 304          * corner is fixed to (0,0) and the size to 1/2 or 1/4 of the crop
 305          * rectangle.
 306          */
 307         sel->r.left = 0;
 308         sel->r.top = 0;
 309
 310         crop = vsp1_entity_get_pad_selection(&histo->entity, config, sel->pad,
 311                                              V4L2_SEL_TGT_CROP);
 312
 313         /*
 314          * Clamp the width and height to acceptable values first and then
 315          * compute the closest rounded dividing ratio.
 316          *
 317          * Ratio        Rounded ratio
 318          * --------------------------
 319          * [1.0 1.5[    1
 320          * [1.5 3.0[    2
 321          * [3.0 4.0]    4
 322          *
 323          * The rounded ratio can be computed using
 324          *
 325          * 1 << (ceil(ratio * 2) / 3)
 326          */
 327         sel->r.width = clamp(sel->r.width, crop->width / 4, crop->width);
 328         ratio = 1 << (crop->width * 2 / sel->r.width / 3);
 329         sel->r.width = crop->width / ratio;
 330
 331
 332         sel->r.height = clamp(sel->r.height, crop->height / 4, crop->height);
 333         ratio = 1 << (crop->height * 2 / sel->r.height / 3);
 334         sel->r.height = crop->height / ratio;
 335
 336         compose = vsp1_entity_get_pad_selection(&histo->entity, config,
 337                                                 sel->pad,
 338                                                 V4L2_SEL_TGT_COMPOSE);
 339         *compose = sel->r;
 340
 341         return 0;
 342 }
 343
 344 static int histo_set_selection(struct v4l2_subdev *subdev,
 345                                struct v4l2_subdev_pad_config *cfg,
 346                                struct v4l2_subdev_selection *sel)
 347 {
 348         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 349         struct v4l2_subdev_pad_config *config;
 350         int ret;
 351
 352         if (sel->pad != HISTO_PAD_SINK)
 353                 return -EINVAL;
 354
 355         mutex_lock(&histo->entity.lock);
 356
 357         config = vsp1_entity_get_pad_config(&histo->entity, cfg, sel->which);
 358         if (!config) {
 359                 ret = -EINVAL;
 360                 goto done;
 361         }
 362
 363         if (sel->target == V4L2_SEL_TGT_CROP)
 364                 ret = histo_set_crop(subdev, config, sel);
 365         else if (sel->target == V4L2_SEL_TGT_COMPOSE)
 366                 ret = histo_set_compose(subdev, config, sel);
 367         else
 368                 ret = -EINVAL;
 369
 370 done:
 371         mutex_unlock(&histo->entity.lock);
 372         return ret;
 373 }
 374
 375 static int histo_get_format(struct v4l2_subdev *subdev,
 376                             struct v4l2_subdev_pad_config *cfg,
 377                             struct v4l2_subdev_format *fmt)
 378 {
 379         if (fmt->pad == HISTO_PAD_SOURCE) {
 380                 fmt->format.code = MEDIA_BUS_FMT_FIXED;
 381                 fmt->format.width = 0;
 382                 fmt->format.height = 0;
 383                 fmt->format.field = V4L2_FIELD_NONE;
 384                 fmt->format.colorspace = V4L2_COLORSPACE_RAW;
 385                 return 0;
 386         }
 387
 388         return vsp1_subdev_get_pad_format(subdev, cfg, fmt);
 389 }
 390
 391 static int histo_set_format(struct v4l2_subdev *subdev,
 392                             struct v4l2_subdev_pad_config *cfg,
 393                             struct v4l2_subdev_format *fmt)
 394 {
 395         struct vsp1_histogram *histo = subdev_to_histo(subdev);
 396         struct v4l2_subdev_pad_config *config;
 397         struct v4l2_mbus_framefmt *format;
 398         struct v4l2_rect *selection;
 399         unsigned int i;
 400         int ret = 0;
 401
 402         if (fmt->pad != HISTO_PAD_SINK)
 403                 return histo_get_format(subdev, cfg, fmt);
 404
 405         mutex_lock(&histo->entity.lock);
 406
 407         config = vsp1_entity_get_pad_config(&histo->entity, cfg, fmt->which);
 408         if (!config) {
 409                 ret = -EINVAL;
 410                 goto done;
 411         }
 412
 413         /*
 414          * Default to the first format if the requested format is not
 415          * supported.
 416          */
 417         for (i = 0; i < histo->num_formats; ++i) {
 418                 if (fmt->format.code == histo->formats[i])
 419                         break;
 420         }
 421         if (i == histo->num_formats)
 422                 fmt->format.code = histo->formats[0];
 423
 424         format = vsp1_entity_get_pad_format(&histo->entity, config, fmt->pad);
 425
 426         format->code = fmt->format.code;
 427         format->width = clamp_t(unsigned int, fmt->format.width,
 428                                 HISTO_MIN_SIZE, HISTO_MAX_SIZE);
 429         format->height = clamp_t(unsigned int, fmt->format.height,
 430                                  HISTO_MIN_SIZE, HISTO_MAX_SIZE);
 431         format->field = V4L2_FIELD_NONE;
 432         format->colorspace = V4L2_COLORSPACE_SRGB;
 433
 434         fmt->format = *format;
 435
 436         /* Reset the crop and compose rectangles */
 437         selection = vsp1_entity_get_pad_selection(&histo->entity, config,
 438                                                   fmt->pad, V4L2_SEL_TGT_CROP);
 439         selection->left = 0;
 440         selection->top = 0;
 441         selection->width = format->width;
 442         selection->height = format->height;
 443
 444         selection = vsp1_entity_get_pad_selection(&histo->entity, config,
 445                                                   fmt->pad,
 446                                                   V4L2_SEL_TGT_COMPOSE);
 447         selection->left = 0;
 448         selection->top = 0;
 449         selection->width = format->width;
 450         selection->height = format->height;
 451
 452 done:
 453         mutex_unlock(&histo->entity.lock);
 454         return ret;
 455 }
 456
 457 static const struct v4l2_subdev_pad_ops histo_pad_ops = {
 458         .enum_mbus_code = histo_enum_mbus_code,
 459         .enum_frame_size = histo_enum_frame_size,
 460         .get_fmt = histo_get_format,
 461         .set_fmt = histo_set_format,
 462         .get_selection = histo_get_selection,
 463         .set_selection = histo_set_selection,
 464 };
 465
 466 static const struct v4l2_subdev_ops histo_ops = {
 467         .pad    = &histo_pad_ops,
 468 };
 469
 470 /* -----------------------------------------------------------------------------
 471  * V4L2 ioctls
 472  */
 473
 474 static int histo_v4l2_querycap(struct file *file, void *fh,
 475                                struct v4l2_capability *cap)
 476 {
 477         struct v4l2_fh *vfh = file->private_data;
 478         struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
 479
 480         cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
 481                           | V4L2_CAP_VIDEO_CAPTURE_MPLANE
 482                           | V4L2_CAP_VIDEO_OUTPUT_MPLANE
 483                           | V4L2_CAP_META_CAPTURE;
 484         cap->device_caps = V4L2_CAP_META_CAPTURE
 485                          | V4L2_CAP_STREAMING;
 486
 487         strlcpy(cap->driver, "vsp1", sizeof(cap->driver));
 488         strlcpy(cap->card, histo->video.name, sizeof(cap->card));
 489         snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
 490                  dev_name(histo->entity.vsp1->dev));
 491
 492         return 0;
 493 }
 494
 495 static int histo_v4l2_enum_format(struct file *file, void *fh,
 496                                   struct v4l2_fmtdesc *f)
 497 {
 498         struct v4l2_fh *vfh = file->private_data;
 499         struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
 500
 501         if (f->index > 0 || f->type != histo->queue.type)
 502                 return -EINVAL;
 503
 504         f->pixelformat = histo->meta_format;
 505
 506         return 0;
 507 }
 508
 509 static int histo_v4l2_get_format(struct file *file, void *fh,
 510                                  struct v4l2_format *format)
 511 {
 512         struct v4l2_fh *vfh = file->private_data;
 513         struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
 514         struct v4l2_meta_format *meta = &format->fmt.meta;
 515
 516         if (format->type != histo->queue.type)
 517                 return -EINVAL;
 518
 519         memset(meta, 0, sizeof(*meta));
 520
 521         meta->dataformat = histo->meta_format;
 522         meta->buffersize = histo->data_size;
 523
 524         return 0;
 525 }
 526
 527 static const struct v4l2_ioctl_ops histo_v4l2_ioctl_ops = {
 528         .vidioc_querycap                = histo_v4l2_querycap,
 529         .vidioc_enum_fmt_meta_cap       = histo_v4l2_enum_format,
 530         .vidioc_g_fmt_meta_cap          = histo_v4l2_get_format,
 531         .vidioc_s_fmt_meta_cap          = histo_v4l2_get_format,
 532         .vidioc_try_fmt_meta_cap        = histo_v4l2_get_format,
 533         .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
 534         .vidioc_querybuf                = vb2_ioctl_querybuf,
 535         .vidioc_qbuf                    = vb2_ioctl_qbuf,
 536         .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
 537         .vidioc_create_bufs             = vb2_ioctl_create_bufs,
 538         .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
 539         .vidioc_streamon                = vb2_ioctl_streamon,
 540         .vidioc_streamoff               = vb2_ioctl_streamoff,
 541 };
 542
 543 /* -----------------------------------------------------------------------------
 544  * V4L2 File Operations
 545  */
 546
 547 static const struct v4l2_file_operations histo_v4l2_fops = {
 548         .owner = THIS_MODULE,
 549         .unlocked_ioctl = video_ioctl2,
 550         .open = v4l2_fh_open,
 551         .release = vb2_fop_release,
 552         .poll = vb2_fop_poll,
 553         .mmap = vb2_fop_mmap,
 554 };
 555
 556 static void vsp1_histogram_cleanup(struct vsp1_histogram *histo)
 557 {
 558         if (video_is_registered(&histo->video))
 559                 video_unregister_device(&histo->video);
 560
 561         media_entity_cleanup(&histo->video.entity);
 562 }
 563
 564 void vsp1_histogram_destroy(struct vsp1_entity *entity)
 565 {
 566         struct vsp1_histogram *histo = subdev_to_histo(&entity->subdev);
 567
 568         vsp1_histogram_cleanup(histo);
 569 }
 570
 571 int vsp1_histogram_init(struct vsp1_device *vsp1, struct vsp1_histogram *histo,
 572                         enum vsp1_entity_type type, const char *name,
 573                         const struct vsp1_entity_operations *ops,
 574                         const unsigned int *formats, unsigned int num_formats,
 575                         size_t data_size, u32 meta_format)
 576 {
 577         int ret;
 578
 579         histo->formats = formats;
 580         histo->num_formats = num_formats;
 581         histo->data_size = data_size;
 582         histo->meta_format = meta_format;
 583
 584         histo->pad.flags = MEDIA_PAD_FL_SINK;
 585         histo->video.vfl_dir = VFL_DIR_RX;
 586
 587         mutex_init(&histo->lock);
 588         spin_lock_init(&histo->irqlock);
 589         INIT_LIST_HEAD(&histo->irqqueue);
 590         init_waitqueue_head(&histo->wait_queue);
 591
 592         /* Initialize the VSP entity... */
 593         histo->entity.ops = ops;
 594         histo->entity.type = type;
 595
 596         ret = vsp1_entity_init(vsp1, &histo->entity, name, 2, &histo_ops,
 597                                MEDIA_ENT_F_PROC_VIDEO_STATISTICS);
 598         if (ret < 0)
 599                 return ret;
 600
 601         /* ... and the media entity... */
 602         ret = media_entity_pads_init(&histo->video.entity, 1, &histo->pad);
 603         if (ret < 0)
 604                 return ret;
 605
 606         /* ... and the video node... */
 607         histo->video.v4l2_dev = &vsp1->v4l2_dev;
 608         histo->video.fops = &histo_v4l2_fops;
 609         snprintf(histo->video.name, sizeof(histo->video.name),
 610                  "%s histo", histo->entity.subdev.name);
 611         histo->video.vfl_type = VFL_TYPE_GRABBER;
 612         histo->video.release = video_device_release_empty;
 613         histo->video.ioctl_ops = &histo_v4l2_ioctl_ops;
 614
 615         video_set_drvdata(&histo->video, histo);
 616
 617         /* ... and the buffers queue... */
 618         histo->queue.type = V4L2_BUF_TYPE_META_CAPTURE;
 619         histo->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
 620         histo->queue.lock = &histo->lock;
 621         histo->queue.drv_priv = histo;
 622         histo->queue.buf_struct_size = sizeof(struct vsp1_histogram_buffer);
 623         histo->queue.ops = &histo_video_queue_qops;
 624         histo->queue.mem_ops = &vb2_vmalloc_memops;
 625         histo->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
 626         histo->queue.dev = vsp1->dev;
 627         ret = vb2_queue_init(&histo->queue);
 628         if (ret < 0) {
 629                 dev_err(vsp1->dev, "failed to initialize vb2 queue\n");
 630                 goto error;
 631         }
 632
 633         /* ... and register the video device. */
 634         histo->video.queue = &histo->queue;
 635         ret = video_register_device(&histo->video, VFL_TYPE_GRABBER, -1);
 636         if (ret < 0) {
 637                 dev_err(vsp1->dev, "failed to register video device\n");
 638                 goto error;
 639         }
 640
 641         return 0;
 642
 643 error:
 644         vsp1_histogram_cleanup(histo);
 645         return ret;
 646 }