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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * vsp1_histo.c  --  R-Car VSP1 Histogram API
4  *
5  * Copyright (C) 2016 Renesas Electronics Corporation
6  * Copyright (C) 2016 Laurent Pinchart
7  *
8  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
9  */
10 
11 #include <linux/device.h>
12 #include <linux/gfp.h>
13 
14 #include <media/v4l2-ioctl.h>
15 #include <media/v4l2-subdev.h>
16 #include <media/videobuf2-vmalloc.h>
17 
18 #include "vsp1.h"
19 #include "vsp1_histo.h"
20 #include "vsp1_pipe.h"
21 
22 #define HISTO_MIN_SIZE				4U
23 #define HISTO_MAX_SIZE				8192U
24 
25 /* -----------------------------------------------------------------------------
26  * Buffer Operations
27  */
28 
29 static inline struct vsp1_histogram_buffer *
to_vsp1_histogram_buffer(struct vb2_v4l2_buffer * vbuf)30 to_vsp1_histogram_buffer(struct vb2_v4l2_buffer *vbuf)
31 {
32 	return container_of(vbuf, struct vsp1_histogram_buffer, buf);
33 }
34 
35 struct vsp1_histogram_buffer *
vsp1_histogram_buffer_get(struct vsp1_histogram * histo)36 vsp1_histogram_buffer_get(struct vsp1_histogram *histo)
37 {
38 	struct vsp1_histogram_buffer *buf = NULL;
39 	unsigned long flags;
40 
41 	spin_lock_irqsave(&histo->irqlock, flags);
42 
43 	if (list_empty(&histo->irqqueue))
44 		goto done;
45 
46 	buf = list_first_entry(&histo->irqqueue, struct vsp1_histogram_buffer,
47 			       queue);
48 	list_del(&buf->queue);
49 	histo->readout = true;
50 
51 done:
52 	spin_unlock_irqrestore(&histo->irqlock, flags);
53 	return buf;
54 }
55 
vsp1_histogram_buffer_complete(struct vsp1_histogram * histo,struct vsp1_histogram_buffer * buf,size_t size)56 void vsp1_histogram_buffer_complete(struct vsp1_histogram *histo,
57 				    struct vsp1_histogram_buffer *buf,
58 				    size_t size)
59 {
60 	struct vsp1_pipeline *pipe = histo->entity.pipe;
61 	unsigned long flags;
62 
63 	/*
64 	 * The pipeline pointer is guaranteed to be valid as this function is
65 	 * called from the frame completion interrupt handler, which can only
66 	 * occur when video streaming is active.
67 	 */
68 	buf->buf.sequence = pipe->sequence;
69 	buf->buf.vb2_buf.timestamp = ktime_get_ns();
70 	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, size);
71 	vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
72 
73 	spin_lock_irqsave(&histo->irqlock, flags);
74 	histo->readout = false;
75 	wake_up(&histo->wait_queue);
76 	spin_unlock_irqrestore(&histo->irqlock, flags);
77 }
78 
79 /* -----------------------------------------------------------------------------
80  * videobuf2 Queue Operations
81  */
82 
histo_queue_setup(struct vb2_queue * vq,unsigned int * nbuffers,unsigned int * nplanes,unsigned int sizes[],struct device * alloc_devs[])83 static int histo_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
84 			     unsigned int *nplanes, unsigned int sizes[],
85 			     struct device *alloc_devs[])
86 {
87 	struct vsp1_histogram *histo = vb2_get_drv_priv(vq);
88 
89 	if (*nplanes) {
90 		if (*nplanes != 1)
91 			return -EINVAL;
92 
93 		if (sizes[0] < histo->data_size)
94 			return -EINVAL;
95 
96 		return 0;
97 	}
98 
99 	*nplanes = 1;
100 	sizes[0] = histo->data_size;
101 
102 	return 0;
103 }
104 
histo_buffer_prepare(struct vb2_buffer * vb)105 static int histo_buffer_prepare(struct vb2_buffer *vb)
106 {
107 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
108 	struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
109 	struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);
110 
111 	if (vb->num_planes != 1)
112 		return -EINVAL;
113 
114 	if (vb2_plane_size(vb, 0) < histo->data_size)
115 		return -EINVAL;
116 
117 	buf->addr = vb2_plane_vaddr(vb, 0);
118 
119 	return 0;
120 }
121 
histo_buffer_queue(struct vb2_buffer * vb)122 static void histo_buffer_queue(struct vb2_buffer *vb)
123 {
124 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
125 	struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
126 	struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);
127 	unsigned long flags;
128 
129 	spin_lock_irqsave(&histo->irqlock, flags);
130 	list_add_tail(&buf->queue, &histo->irqqueue);
131 	spin_unlock_irqrestore(&histo->irqlock, flags);
132 }
133 
histo_start_streaming(struct vb2_queue * vq,unsigned int count)134 static int histo_start_streaming(struct vb2_queue *vq, unsigned int count)
135 {
136 	return 0;
137 }
138 
histo_stop_streaming(struct vb2_queue * vq)139 static void histo_stop_streaming(struct vb2_queue *vq)
140 {
141 	struct vsp1_histogram *histo = vb2_get_drv_priv(vq);
142 	struct vsp1_histogram_buffer *buffer;
143 	unsigned long flags;
144 
145 	spin_lock_irqsave(&histo->irqlock, flags);
146 
147 	/* Remove all buffers from the IRQ queue. */
148 	list_for_each_entry(buffer, &histo->irqqueue, queue)
149 		vb2_buffer_done(&buffer->buf.vb2_buf, VB2_BUF_STATE_ERROR);
150 	INIT_LIST_HEAD(&histo->irqqueue);
151 
152 	/* Wait for the buffer being read out (if any) to complete. */
153 	wait_event_lock_irq(histo->wait_queue, !histo->readout, histo->irqlock);
154 
155 	spin_unlock_irqrestore(&histo->irqlock, flags);
156 }
157 
158 static const struct vb2_ops histo_video_queue_qops = {
159 	.queue_setup = histo_queue_setup,
160 	.buf_prepare = histo_buffer_prepare,
161 	.buf_queue = histo_buffer_queue,
162 	.wait_prepare = vb2_ops_wait_prepare,
163 	.wait_finish = vb2_ops_wait_finish,
164 	.start_streaming = histo_start_streaming,
165 	.stop_streaming = histo_stop_streaming,
166 };
167 
168 /* -----------------------------------------------------------------------------
169  * V4L2 Subdevice Operations
170  */
171 
histo_enum_mbus_code(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_mbus_code_enum * code)172 static int histo_enum_mbus_code(struct v4l2_subdev *subdev,
173 				struct v4l2_subdev_pad_config *cfg,
174 				struct v4l2_subdev_mbus_code_enum *code)
175 {
176 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
177 
178 	if (code->pad == HISTO_PAD_SOURCE) {
179 		code->code = MEDIA_BUS_FMT_FIXED;
180 		return 0;
181 	}
182 
183 	return vsp1_subdev_enum_mbus_code(subdev, cfg, code, histo->formats,
184 					  histo->num_formats);
185 }
186 
histo_enum_frame_size(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_frame_size_enum * fse)187 static int histo_enum_frame_size(struct v4l2_subdev *subdev,
188 				 struct v4l2_subdev_pad_config *cfg,
189 				 struct v4l2_subdev_frame_size_enum *fse)
190 {
191 	if (fse->pad != HISTO_PAD_SINK)
192 		return -EINVAL;
193 
194 	return vsp1_subdev_enum_frame_size(subdev, cfg, fse, HISTO_MIN_SIZE,
195 					   HISTO_MIN_SIZE, HISTO_MAX_SIZE,
196 					   HISTO_MAX_SIZE);
197 }
198 
histo_get_selection(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_selection * sel)199 static int histo_get_selection(struct v4l2_subdev *subdev,
200 			       struct v4l2_subdev_pad_config *cfg,
201 			       struct v4l2_subdev_selection *sel)
202 {
203 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
204 	struct v4l2_subdev_pad_config *config;
205 	struct v4l2_mbus_framefmt *format;
206 	struct v4l2_rect *crop;
207 	int ret = 0;
208 
209 	if (sel->pad != HISTO_PAD_SINK)
210 		return -EINVAL;
211 
212 	mutex_lock(&histo->entity.lock);
213 
214 	config = vsp1_entity_get_pad_config(&histo->entity, cfg, sel->which);
215 	if (!config) {
216 		ret = -EINVAL;
217 		goto done;
218 	}
219 
220 	switch (sel->target) {
221 	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
222 	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
223 		crop = vsp1_entity_get_pad_selection(&histo->entity, config,
224 						     HISTO_PAD_SINK,
225 						     V4L2_SEL_TGT_CROP);
226 		sel->r.left = 0;
227 		sel->r.top = 0;
228 		sel->r.width = crop->width;
229 		sel->r.height = crop->height;
230 		break;
231 
232 	case V4L2_SEL_TGT_CROP_BOUNDS:
233 	case V4L2_SEL_TGT_CROP_DEFAULT:
234 		format = vsp1_entity_get_pad_format(&histo->entity, config,
235 						    HISTO_PAD_SINK);
236 		sel->r.left = 0;
237 		sel->r.top = 0;
238 		sel->r.width = format->width;
239 		sel->r.height = format->height;
240 		break;
241 
242 	case V4L2_SEL_TGT_COMPOSE:
243 	case V4L2_SEL_TGT_CROP:
244 		sel->r = *vsp1_entity_get_pad_selection(&histo->entity, config,
245 							sel->pad, sel->target);
246 		break;
247 
248 	default:
249 		ret = -EINVAL;
250 		break;
251 	}
252 
253 done:
254 	mutex_unlock(&histo->entity.lock);
255 	return ret;
256 }
257 
histo_set_crop(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * config,struct v4l2_subdev_selection * sel)258 static int histo_set_crop(struct v4l2_subdev *subdev,
259 			  struct v4l2_subdev_pad_config *config,
260 			 struct v4l2_subdev_selection *sel)
261 {
262 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
263 	struct v4l2_mbus_framefmt *format;
264 	struct v4l2_rect *selection;
265 
266 	/* The crop rectangle must be inside the input frame. */
267 	format = vsp1_entity_get_pad_format(&histo->entity, config,
268 					    HISTO_PAD_SINK);
269 	sel->r.left = clamp_t(unsigned int, sel->r.left, 0, format->width - 1);
270 	sel->r.top = clamp_t(unsigned int, sel->r.top, 0, format->height - 1);
271 	sel->r.width = clamp_t(unsigned int, sel->r.width, HISTO_MIN_SIZE,
272 			       format->width - sel->r.left);
273 	sel->r.height = clamp_t(unsigned int, sel->r.height, HISTO_MIN_SIZE,
274 				format->height - sel->r.top);
275 
276 	/* Set the crop rectangle and reset the compose rectangle. */
277 	selection = vsp1_entity_get_pad_selection(&histo->entity, config,
278 						  sel->pad, V4L2_SEL_TGT_CROP);
279 	*selection = sel->r;
280 
281 	selection = vsp1_entity_get_pad_selection(&histo->entity, config,
282 						  sel->pad,
283 						  V4L2_SEL_TGT_COMPOSE);
284 	*selection = sel->r;
285 
286 	return 0;
287 }
288 
histo_set_compose(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * config,struct v4l2_subdev_selection * sel)289 static int histo_set_compose(struct v4l2_subdev *subdev,
290 			     struct v4l2_subdev_pad_config *config,
291 			     struct v4l2_subdev_selection *sel)
292 {
293 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
294 	struct v4l2_rect *compose;
295 	struct v4l2_rect *crop;
296 	unsigned int ratio;
297 
298 	/*
299 	 * The compose rectangle is used to configure downscaling, the top left
300 	 * corner is fixed to (0,0) and the size to 1/2 or 1/4 of the crop
301 	 * rectangle.
302 	 */
303 	sel->r.left = 0;
304 	sel->r.top = 0;
305 
306 	crop = vsp1_entity_get_pad_selection(&histo->entity, config, sel->pad,
307 					     V4L2_SEL_TGT_CROP);
308 
309 	/*
310 	 * Clamp the width and height to acceptable values first and then
311 	 * compute the closest rounded dividing ratio.
312 	 *
313 	 * Ratio	Rounded ratio
314 	 * --------------------------
315 	 * [1.0 1.5[	1
316 	 * [1.5 3.0[	2
317 	 * [3.0 4.0]	4
318 	 *
319 	 * The rounded ratio can be computed using
320 	 *
321 	 * 1 << (ceil(ratio * 2) / 3)
322 	 */
323 	sel->r.width = clamp(sel->r.width, crop->width / 4, crop->width);
324 	ratio = 1 << (crop->width * 2 / sel->r.width / 3);
325 	sel->r.width = crop->width / ratio;
326 
327 
328 	sel->r.height = clamp(sel->r.height, crop->height / 4, crop->height);
329 	ratio = 1 << (crop->height * 2 / sel->r.height / 3);
330 	sel->r.height = crop->height / ratio;
331 
332 	compose = vsp1_entity_get_pad_selection(&histo->entity, config,
333 						sel->pad,
334 						V4L2_SEL_TGT_COMPOSE);
335 	*compose = sel->r;
336 
337 	return 0;
338 }
339 
histo_set_selection(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_selection * sel)340 static int histo_set_selection(struct v4l2_subdev *subdev,
341 			       struct v4l2_subdev_pad_config *cfg,
342 			       struct v4l2_subdev_selection *sel)
343 {
344 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
345 	struct v4l2_subdev_pad_config *config;
346 	int ret;
347 
348 	if (sel->pad != HISTO_PAD_SINK)
349 		return -EINVAL;
350 
351 	mutex_lock(&histo->entity.lock);
352 
353 	config = vsp1_entity_get_pad_config(&histo->entity, cfg, sel->which);
354 	if (!config) {
355 		ret = -EINVAL;
356 		goto done;
357 	}
358 
359 	if (sel->target == V4L2_SEL_TGT_CROP)
360 		ret = histo_set_crop(subdev, config, sel);
361 	else if (sel->target == V4L2_SEL_TGT_COMPOSE)
362 		ret = histo_set_compose(subdev, config, sel);
363 	else
364 		ret = -EINVAL;
365 
366 done:
367 	mutex_unlock(&histo->entity.lock);
368 	return ret;
369 }
370 
histo_get_format(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_format * fmt)371 static int histo_get_format(struct v4l2_subdev *subdev,
372 			    struct v4l2_subdev_pad_config *cfg,
373 			    struct v4l2_subdev_format *fmt)
374 {
375 	if (fmt->pad == HISTO_PAD_SOURCE) {
376 		fmt->format.code = MEDIA_BUS_FMT_FIXED;
377 		fmt->format.width = 0;
378 		fmt->format.height = 0;
379 		fmt->format.field = V4L2_FIELD_NONE;
380 		fmt->format.colorspace = V4L2_COLORSPACE_RAW;
381 		return 0;
382 	}
383 
384 	return vsp1_subdev_get_pad_format(subdev, cfg, fmt);
385 }
386 
histo_set_format(struct v4l2_subdev * subdev,struct v4l2_subdev_pad_config * cfg,struct v4l2_subdev_format * fmt)387 static int histo_set_format(struct v4l2_subdev *subdev,
388 			    struct v4l2_subdev_pad_config *cfg,
389 			    struct v4l2_subdev_format *fmt)
390 {
391 	struct vsp1_histogram *histo = subdev_to_histo(subdev);
392 
393 	if (fmt->pad != HISTO_PAD_SINK)
394 		return histo_get_format(subdev, cfg, fmt);
395 
396 	return vsp1_subdev_set_pad_format(subdev, cfg, fmt,
397 					  histo->formats, histo->num_formats,
398 					  HISTO_MIN_SIZE, HISTO_MIN_SIZE,
399 					  HISTO_MAX_SIZE, HISTO_MAX_SIZE);
400 }
401 
402 static const struct v4l2_subdev_pad_ops histo_pad_ops = {
403 	.enum_mbus_code = histo_enum_mbus_code,
404 	.enum_frame_size = histo_enum_frame_size,
405 	.get_fmt = histo_get_format,
406 	.set_fmt = histo_set_format,
407 	.get_selection = histo_get_selection,
408 	.set_selection = histo_set_selection,
409 };
410 
411 static const struct v4l2_subdev_ops histo_ops = {
412 	.pad    = &histo_pad_ops,
413 };
414 
415 /* -----------------------------------------------------------------------------
416  * V4L2 ioctls
417  */
418 
histo_v4l2_querycap(struct file * file,void * fh,struct v4l2_capability * cap)419 static int histo_v4l2_querycap(struct file *file, void *fh,
420 			       struct v4l2_capability *cap)
421 {
422 	struct v4l2_fh *vfh = file->private_data;
423 	struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
424 
425 	cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
426 			  | V4L2_CAP_VIDEO_CAPTURE_MPLANE
427 			  | V4L2_CAP_VIDEO_OUTPUT_MPLANE
428 			  | V4L2_CAP_META_CAPTURE;
429 
430 	strscpy(cap->driver, "vsp1", sizeof(cap->driver));
431 	strscpy(cap->card, histo->video.name, sizeof(cap->card));
432 	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
433 		 dev_name(histo->entity.vsp1->dev));
434 
435 	return 0;
436 }
437 
histo_v4l2_enum_format(struct file * file,void * fh,struct v4l2_fmtdesc * f)438 static int histo_v4l2_enum_format(struct file *file, void *fh,
439 				  struct v4l2_fmtdesc *f)
440 {
441 	struct v4l2_fh *vfh = file->private_data;
442 	struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
443 
444 	if (f->index > 0 || f->type != histo->queue.type)
445 		return -EINVAL;
446 
447 	f->pixelformat = histo->meta_format;
448 
449 	return 0;
450 }
451 
histo_v4l2_get_format(struct file * file,void * fh,struct v4l2_format * format)452 static int histo_v4l2_get_format(struct file *file, void *fh,
453 				 struct v4l2_format *format)
454 {
455 	struct v4l2_fh *vfh = file->private_data;
456 	struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
457 	struct v4l2_meta_format *meta = &format->fmt.meta;
458 
459 	if (format->type != histo->queue.type)
460 		return -EINVAL;
461 
462 	memset(meta, 0, sizeof(*meta));
463 
464 	meta->dataformat = histo->meta_format;
465 	meta->buffersize = histo->data_size;
466 
467 	return 0;
468 }
469 
470 static const struct v4l2_ioctl_ops histo_v4l2_ioctl_ops = {
471 	.vidioc_querycap		= histo_v4l2_querycap,
472 	.vidioc_enum_fmt_meta_cap	= histo_v4l2_enum_format,
473 	.vidioc_g_fmt_meta_cap		= histo_v4l2_get_format,
474 	.vidioc_s_fmt_meta_cap		= histo_v4l2_get_format,
475 	.vidioc_try_fmt_meta_cap	= histo_v4l2_get_format,
476 	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
477 	.vidioc_querybuf		= vb2_ioctl_querybuf,
478 	.vidioc_qbuf			= vb2_ioctl_qbuf,
479 	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
480 	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
481 	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
482 	.vidioc_streamon		= vb2_ioctl_streamon,
483 	.vidioc_streamoff		= vb2_ioctl_streamoff,
484 };
485 
486 /* -----------------------------------------------------------------------------
487  * V4L2 File Operations
488  */
489 
490 static const struct v4l2_file_operations histo_v4l2_fops = {
491 	.owner = THIS_MODULE,
492 	.unlocked_ioctl = video_ioctl2,
493 	.open = v4l2_fh_open,
494 	.release = vb2_fop_release,
495 	.poll = vb2_fop_poll,
496 	.mmap = vb2_fop_mmap,
497 };
498 
vsp1_histogram_cleanup(struct vsp1_histogram * histo)499 static void vsp1_histogram_cleanup(struct vsp1_histogram *histo)
500 {
501 	if (video_is_registered(&histo->video))
502 		video_unregister_device(&histo->video);
503 
504 	media_entity_cleanup(&histo->video.entity);
505 }
506 
vsp1_histogram_destroy(struct vsp1_entity * entity)507 void vsp1_histogram_destroy(struct vsp1_entity *entity)
508 {
509 	struct vsp1_histogram *histo = subdev_to_histo(&entity->subdev);
510 
511 	vsp1_histogram_cleanup(histo);
512 }
513 
vsp1_histogram_init(struct vsp1_device * vsp1,struct vsp1_histogram * histo,enum vsp1_entity_type type,const char * name,const struct vsp1_entity_operations * ops,const unsigned int * formats,unsigned int num_formats,size_t data_size,u32 meta_format)514 int vsp1_histogram_init(struct vsp1_device *vsp1, struct vsp1_histogram *histo,
515 			enum vsp1_entity_type type, const char *name,
516 			const struct vsp1_entity_operations *ops,
517 			const unsigned int *formats, unsigned int num_formats,
518 			size_t data_size, u32 meta_format)
519 {
520 	int ret;
521 
522 	histo->formats = formats;
523 	histo->num_formats = num_formats;
524 	histo->data_size = data_size;
525 	histo->meta_format = meta_format;
526 
527 	histo->pad.flags = MEDIA_PAD_FL_SINK;
528 	histo->video.vfl_dir = VFL_DIR_RX;
529 
530 	mutex_init(&histo->lock);
531 	spin_lock_init(&histo->irqlock);
532 	INIT_LIST_HEAD(&histo->irqqueue);
533 	init_waitqueue_head(&histo->wait_queue);
534 
535 	/* Initialize the VSP entity... */
536 	histo->entity.ops = ops;
537 	histo->entity.type = type;
538 
539 	ret = vsp1_entity_init(vsp1, &histo->entity, name, 2, &histo_ops,
540 			       MEDIA_ENT_F_PROC_VIDEO_STATISTICS);
541 	if (ret < 0)
542 		return ret;
543 
544 	/* ... and the media entity... */
545 	ret = media_entity_pads_init(&histo->video.entity, 1, &histo->pad);
546 	if (ret < 0)
547 		return ret;
548 
549 	/* ... and the video node... */
550 	histo->video.v4l2_dev = &vsp1->v4l2_dev;
551 	histo->video.fops = &histo_v4l2_fops;
552 	snprintf(histo->video.name, sizeof(histo->video.name),
553 		 "%s histo", histo->entity.subdev.name);
554 	histo->video.vfl_type = VFL_TYPE_VIDEO;
555 	histo->video.release = video_device_release_empty;
556 	histo->video.ioctl_ops = &histo_v4l2_ioctl_ops;
557 	histo->video.device_caps = V4L2_CAP_META_CAPTURE | V4L2_CAP_STREAMING;
558 
559 	video_set_drvdata(&histo->video, histo);
560 
561 	/* ... and the buffers queue... */
562 	histo->queue.type = V4L2_BUF_TYPE_META_CAPTURE;
563 	histo->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
564 	histo->queue.lock = &histo->lock;
565 	histo->queue.drv_priv = histo;
566 	histo->queue.buf_struct_size = sizeof(struct vsp1_histogram_buffer);
567 	histo->queue.ops = &histo_video_queue_qops;
568 	histo->queue.mem_ops = &vb2_vmalloc_memops;
569 	histo->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
570 	histo->queue.dev = vsp1->dev;
571 	ret = vb2_queue_init(&histo->queue);
572 	if (ret < 0) {
573 		dev_err(vsp1->dev, "failed to initialize vb2 queue\n");
574 		goto error;
575 	}
576 
577 	/* ... and register the video device. */
578 	histo->video.queue = &histo->queue;
579 	ret = video_register_device(&histo->video, VFL_TYPE_VIDEO, -1);
580 	if (ret < 0) {
581 		dev_err(vsp1->dev, "failed to register video device\n");
582 		goto error;
583 	}
584 
585 	return 0;
586 
587 error:
588 	vsp1_histogram_cleanup(histo);
589 	return ret;
590 }
591