1/*
2 * videobuf2-v4l2.c - V4L2 driver helper framework
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
8 *
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
15 */
16
17#include <linux/device.h>
18#include <linux/err.h>
19#include <linux/freezer.h>
20#include <linux/kernel.h>
21#include <linux/kthread.h>
22#include <linux/mm.h>
23#include <linux/module.h>
24#include <linux/poll.h>
25#include <linux/sched.h>
26#include <linux/slab.h>
27
28#include <media/v4l2-common.h>
29#include <media/v4l2-dev.h>
30#include <media/v4l2-device.h>
31#include <media/v4l2-event.h>
32#include <media/v4l2-fh.h>
33
34#include <media/videobuf2-v4l2.h>
35
36static int debug;
37module_param(debug, int, 0644);
38
39#define dprintk(q, level, fmt, arg...) \
40 do { \
41 if (debug >= level) \
42 pr_info("vb2-v4l2: [%p] %s: " fmt, \
43 (q)->name, __func__, ## arg); \
44 } while (0)
45
46/* Flags that are set by us */
47#define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
48 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
49 V4L2_BUF_FLAG_PREPARED | \
50 V4L2_BUF_FLAG_IN_REQUEST | \
51 V4L2_BUF_FLAG_REQUEST_FD | \
52 V4L2_BUF_FLAG_TIMESTAMP_MASK)
53/* Output buffer flags that should be passed on to the driver */
54#define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | \
55 V4L2_BUF_FLAG_BFRAME | \
56 V4L2_BUF_FLAG_KEYFRAME | \
57 V4L2_BUF_FLAG_TIMECODE | \
58 V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)
59
60/*
61 * __verify_planes_array() - verify that the planes array passed in struct
62 * v4l2_buffer from userspace can be safely used
63 */
64static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
65{
66 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
67 return 0;
68
69 /* Is memory for copying plane information present? */
70 if (b->m.planes == NULL) {
71 dprintk(vb->vb2_queue, 1,
72 "multi-planar buffer passed but planes array not provided\n");
73 return -EINVAL;
74 }
75
76 if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
77 dprintk(vb->vb2_queue, 1,
78 "incorrect planes array length, expected %d, got %d\n",
79 vb->num_planes, b->length);
80 return -EINVAL;
81 }
82
83 return 0;
84}
85
86static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
87{
88 return __verify_planes_array(vb, b: pb);
89}
90
91/*
92 * __verify_length() - Verify that the bytesused value for each plane fits in
93 * the plane length and that the data offset doesn't exceed the bytesused value.
94 */
95static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
96{
97 unsigned int length;
98 unsigned int bytesused;
99 unsigned int plane;
100
101 if (V4L2_TYPE_IS_CAPTURE(b->type))
102 return 0;
103
104 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
105 for (plane = 0; plane < vb->num_planes; ++plane) {
106 length = (b->memory == VB2_MEMORY_USERPTR ||
107 b->memory == VB2_MEMORY_DMABUF)
108 ? b->m.planes[plane].length
109 : vb->planes[plane].length;
110 bytesused = b->m.planes[plane].bytesused
111 ? b->m.planes[plane].bytesused : length;
112
113 if (b->m.planes[plane].bytesused > length)
114 return -EINVAL;
115
116 if (b->m.planes[plane].data_offset > 0 &&
117 b->m.planes[plane].data_offset >= bytesused)
118 return -EINVAL;
119 }
120 } else {
121 length = (b->memory == VB2_MEMORY_USERPTR)
122 ? b->length : vb->planes[0].length;
123
124 if (b->bytesused > length)
125 return -EINVAL;
126 }
127
128 return 0;
129}
130
131/*
132 * __init_vb2_v4l2_buffer() - initialize the vb2_v4l2_buffer struct
133 */
134static void __init_vb2_v4l2_buffer(struct vb2_buffer *vb)
135{
136 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
137
138 vbuf->request_fd = -1;
139}
140
141static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
142{
143 const struct v4l2_buffer *b = pb;
144 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
145 struct vb2_queue *q = vb->vb2_queue;
146
147 if (q->is_output) {
148 /*
149 * For output buffers copy the timestamp if needed,
150 * and the timecode field and flag if needed.
151 */
152 if (q->copy_timestamp)
153 vb->timestamp = v4l2_buffer_get_timestamp(buf: b);
154 vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
155 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
156 vbuf->timecode = b->timecode;
157 }
158};
159
160static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
161{
162 static bool check_once;
163
164 if (check_once)
165 return;
166
167 check_once = true;
168
169 pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
170 if (vb->vb2_queue->allow_zero_bytesused)
171 pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
172 else
173 pr_warn("use the actual size instead.\n");
174}
175
176static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
177{
178 struct vb2_queue *q = vb->vb2_queue;
179 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
180 struct vb2_plane *planes = vbuf->planes;
181 unsigned int plane;
182 int ret;
183
184 ret = __verify_length(vb, b);
185 if (ret < 0) {
186 dprintk(q, 1, "plane parameters verification failed: %d\n", ret);
187 return ret;
188 }
189 if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
190 /*
191 * If the format's field is ALTERNATE, then the buffer's field
192 * should be either TOP or BOTTOM, not ALTERNATE since that
193 * makes no sense. The driver has to know whether the
194 * buffer represents a top or a bottom field in order to
195 * program any DMA correctly. Using ALTERNATE is wrong, since
196 * that just says that it is either a top or a bottom field,
197 * but not which of the two it is.
198 */
199 dprintk(q, 1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
200 return -EINVAL;
201 }
202 vbuf->sequence = 0;
203 vbuf->request_fd = -1;
204 vbuf->is_held = false;
205
206 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
207 switch (b->memory) {
208 case VB2_MEMORY_USERPTR:
209 for (plane = 0; plane < vb->num_planes; ++plane) {
210 planes[plane].m.userptr =
211 b->m.planes[plane].m.userptr;
212 planes[plane].length =
213 b->m.planes[plane].length;
214 }
215 break;
216 case VB2_MEMORY_DMABUF:
217 for (plane = 0; plane < vb->num_planes; ++plane) {
218 planes[plane].m.fd =
219 b->m.planes[plane].m.fd;
220 planes[plane].length =
221 b->m.planes[plane].length;
222 }
223 break;
224 default:
225 for (plane = 0; plane < vb->num_planes; ++plane) {
226 planes[plane].m.offset =
227 vb->planes[plane].m.offset;
228 planes[plane].length =
229 vb->planes[plane].length;
230 }
231 break;
232 }
233
234 /* Fill in driver-provided information for OUTPUT types */
235 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
236 /*
237 * Will have to go up to b->length when API starts
238 * accepting variable number of planes.
239 *
240 * If bytesused == 0 for the output buffer, then fall
241 * back to the full buffer size. In that case
242 * userspace clearly never bothered to set it and
243 * it's a safe assumption that they really meant to
244 * use the full plane sizes.
245 *
246 * Some drivers, e.g. old codec drivers, use bytesused == 0
247 * as a way to indicate that streaming is finished.
248 * In that case, the driver should use the
249 * allow_zero_bytesused flag to keep old userspace
250 * applications working.
251 */
252 for (plane = 0; plane < vb->num_planes; ++plane) {
253 struct vb2_plane *pdst = &planes[plane];
254 struct v4l2_plane *psrc = &b->m.planes[plane];
255
256 if (psrc->bytesused == 0)
257 vb2_warn_zero_bytesused(vb);
258
259 if (vb->vb2_queue->allow_zero_bytesused)
260 pdst->bytesused = psrc->bytesused;
261 else
262 pdst->bytesused = psrc->bytesused ?
263 psrc->bytesused : pdst->length;
264 pdst->data_offset = psrc->data_offset;
265 }
266 }
267 } else {
268 /*
269 * Single-planar buffers do not use planes array,
270 * so fill in relevant v4l2_buffer struct fields instead.
271 * In vb2 we use our internal V4l2_planes struct for
272 * single-planar buffers as well, for simplicity.
273 *
274 * If bytesused == 0 for the output buffer, then fall back
275 * to the full buffer size as that's a sensible default.
276 *
277 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
278 * a way to indicate that streaming is finished. In that case,
279 * the driver should use the allow_zero_bytesused flag to keep
280 * old userspace applications working.
281 */
282 switch (b->memory) {
283 case VB2_MEMORY_USERPTR:
284 planes[0].m.userptr = b->m.userptr;
285 planes[0].length = b->length;
286 break;
287 case VB2_MEMORY_DMABUF:
288 planes[0].m.fd = b->m.fd;
289 planes[0].length = b->length;
290 break;
291 default:
292 planes[0].m.offset = vb->planes[0].m.offset;
293 planes[0].length = vb->planes[0].length;
294 break;
295 }
296
297 planes[0].data_offset = 0;
298 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
299 if (b->bytesused == 0)
300 vb2_warn_zero_bytesused(vb);
301
302 if (vb->vb2_queue->allow_zero_bytesused)
303 planes[0].bytesused = b->bytesused;
304 else
305 planes[0].bytesused = b->bytesused ?
306 b->bytesused : planes[0].length;
307 } else
308 planes[0].bytesused = 0;
309
310 }
311
312 /* Zero flags that we handle */
313 vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
314 if (!vb->vb2_queue->copy_timestamp || V4L2_TYPE_IS_CAPTURE(b->type)) {
315 /*
316 * Non-COPY timestamps and non-OUTPUT queues will get
317 * their timestamp and timestamp source flags from the
318 * queue.
319 */
320 vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
321 }
322
323 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
324 /*
325 * For output buffers mask out the timecode flag:
326 * this will be handled later in vb2_qbuf().
327 * The 'field' is valid metadata for this output buffer
328 * and so that needs to be copied here.
329 */
330 vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
331 vbuf->field = b->field;
332 if (!(q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF))
333 vbuf->flags &= ~V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;
334 } else {
335 /* Zero any output buffer flags as this is a capture buffer */
336 vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
337 /* Zero last flag, this is a signal from driver to userspace */
338 vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
339 }
340
341 return 0;
342}
343
344static void set_buffer_cache_hints(struct vb2_queue *q,
345 struct vb2_buffer *vb,
346 struct v4l2_buffer *b)
347{
348 if (!vb2_queue_allows_cache_hints(q)) {
349 /*
350 * Clear buffer cache flags if queue does not support user
351 * space hints. That's to indicate to userspace that these
352 * flags won't work.
353 */
354 b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;
355 b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;
356 return;
357 }
358
359 if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
360 vb->skip_cache_sync_on_finish = 1;
361
362 if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
363 vb->skip_cache_sync_on_prepare = 1;
364}
365
366static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
367 struct vb2_buffer *vb, struct v4l2_buffer *b,
368 bool is_prepare, struct media_request **p_req)
369{
370 const char *opname = is_prepare ? "prepare_buf" : "qbuf";
371 struct media_request *req;
372 struct vb2_v4l2_buffer *vbuf;
373 int ret;
374
375 if (b->type != q->type) {
376 dprintk(q, 1, "%s: invalid buffer type\n", opname);
377 return -EINVAL;
378 }
379
380 if (b->memory != q->memory) {
381 dprintk(q, 1, "%s: invalid memory type\n", opname);
382 return -EINVAL;
383 }
384
385 vbuf = to_vb2_v4l2_buffer(vb);
386 ret = __verify_planes_array(vb, b);
387 if (ret)
388 return ret;
389
390 if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&
391 vb->state != VB2_BUF_STATE_DEQUEUED) {
392 dprintk(q, 1, "%s: buffer is not in dequeued state\n", opname);
393 return -EINVAL;
394 }
395
396 if (!vb->prepared) {
397 set_buffer_cache_hints(q, vb, b);
398 /* Copy relevant information provided by the userspace */
399 memset(vbuf->planes, 0,
400 sizeof(vbuf->planes[0]) * vb->num_planes);
401 ret = vb2_fill_vb2_v4l2_buffer(vb, b);
402 if (ret)
403 return ret;
404 }
405
406 if (is_prepare)
407 return 0;
408
409 if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
410 if (q->requires_requests) {
411 dprintk(q, 1, "%s: queue requires requests\n", opname);
412 return -EBADR;
413 }
414 if (q->uses_requests) {
415 dprintk(q, 1, "%s: queue uses requests\n", opname);
416 return -EBUSY;
417 }
418 return 0;
419 } else if (!q->supports_requests) {
420 dprintk(q, 1, "%s: queue does not support requests\n", opname);
421 return -EBADR;
422 } else if (q->uses_qbuf) {
423 dprintk(q, 1, "%s: queue does not use requests\n", opname);
424 return -EBUSY;
425 }
426
427 /*
428 * For proper locking when queueing a request you need to be able
429 * to lock access to the vb2 queue, so check that there is a lock
430 * that we can use. In addition p_req must be non-NULL.
431 */
432 if (WARN_ON(!q->lock || !p_req))
433 return -EINVAL;
434
435 /*
436 * Make sure this op is implemented by the driver. It's easy to forget
437 * this callback, but is it important when canceling a buffer in a
438 * queued request.
439 */
440 if (WARN_ON(!q->ops->buf_request_complete))
441 return -EINVAL;
442 /*
443 * Make sure this op is implemented by the driver for the output queue.
444 * It's easy to forget this callback, but is it important to correctly
445 * validate the 'field' value at QBUF time.
446 */
447 if (WARN_ON((q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||
448 q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) &&
449 !q->ops->buf_out_validate))
450 return -EINVAL;
451
452 req = media_request_get_by_fd(mdev, request_fd: b->request_fd);
453 if (IS_ERR(ptr: req)) {
454 dprintk(q, 1, "%s: invalid request_fd\n", opname);
455 return PTR_ERR(ptr: req);
456 }
457
458 /*
459 * Early sanity check. This is checked again when the buffer
460 * is bound to the request in vb2_core_qbuf().
461 */
462 if (req->state != MEDIA_REQUEST_STATE_IDLE &&
463 req->state != MEDIA_REQUEST_STATE_UPDATING) {
464 dprintk(q, 1, "%s: request is not idle\n", opname);
465 media_request_put(req);
466 return -EBUSY;
467 }
468
469 *p_req = req;
470 vbuf->request_fd = b->request_fd;
471
472 return 0;
473}
474
475/*
476 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
477 * returned to userspace
478 */
479static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
480{
481 struct v4l2_buffer *b = pb;
482 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
483 struct vb2_queue *q = vb->vb2_queue;
484 unsigned int plane;
485
486 /* Copy back data such as timestamp, flags, etc. */
487 b->index = vb->index;
488 b->type = vb->type;
489 b->memory = vb->memory;
490 b->bytesused = 0;
491
492 b->flags = vbuf->flags;
493 b->field = vbuf->field;
494 v4l2_buffer_set_timestamp(buf: b, timestamp: vb->timestamp);
495 b->timecode = vbuf->timecode;
496 b->sequence = vbuf->sequence;
497 b->reserved2 = 0;
498 b->request_fd = 0;
499
500 if (q->is_multiplanar) {
501 /*
502 * Fill in plane-related data if userspace provided an array
503 * for it. The caller has already verified memory and size.
504 */
505 b->length = vb->num_planes;
506 for (plane = 0; plane < vb->num_planes; ++plane) {
507 struct v4l2_plane *pdst = &b->m.planes[plane];
508 struct vb2_plane *psrc = &vb->planes[plane];
509
510 pdst->bytesused = psrc->bytesused;
511 pdst->length = psrc->length;
512 if (q->memory == VB2_MEMORY_MMAP)
513 pdst->m.mem_offset = psrc->m.offset;
514 else if (q->memory == VB2_MEMORY_USERPTR)
515 pdst->m.userptr = psrc->m.userptr;
516 else if (q->memory == VB2_MEMORY_DMABUF)
517 pdst->m.fd = psrc->m.fd;
518 pdst->data_offset = psrc->data_offset;
519 memset(pdst->reserved, 0, sizeof(pdst->reserved));
520 }
521 } else {
522 /*
523 * We use length and offset in v4l2_planes array even for
524 * single-planar buffers, but userspace does not.
525 */
526 b->length = vb->planes[0].length;
527 b->bytesused = vb->planes[0].bytesused;
528 if (q->memory == VB2_MEMORY_MMAP)
529 b->m.offset = vb->planes[0].m.offset;
530 else if (q->memory == VB2_MEMORY_USERPTR)
531 b->m.userptr = vb->planes[0].m.userptr;
532 else if (q->memory == VB2_MEMORY_DMABUF)
533 b->m.fd = vb->planes[0].m.fd;
534 }
535
536 /*
537 * Clear any buffer state related flags.
538 */
539 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
540 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
541 if (!q->copy_timestamp) {
542 /*
543 * For non-COPY timestamps, drop timestamp source bits
544 * and obtain the timestamp source from the queue.
545 */
546 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
547 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
548 }
549
550 switch (vb->state) {
551 case VB2_BUF_STATE_QUEUED:
552 case VB2_BUF_STATE_ACTIVE:
553 b->flags |= V4L2_BUF_FLAG_QUEUED;
554 break;
555 case VB2_BUF_STATE_IN_REQUEST:
556 b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
557 break;
558 case VB2_BUF_STATE_ERROR:
559 b->flags |= V4L2_BUF_FLAG_ERROR;
560 fallthrough;
561 case VB2_BUF_STATE_DONE:
562 b->flags |= V4L2_BUF_FLAG_DONE;
563 break;
564 case VB2_BUF_STATE_PREPARING:
565 case VB2_BUF_STATE_DEQUEUED:
566 /* nothing */
567 break;
568 }
569
570 if ((vb->state == VB2_BUF_STATE_DEQUEUED ||
571 vb->state == VB2_BUF_STATE_IN_REQUEST) &&
572 vb->synced && vb->prepared)
573 b->flags |= V4L2_BUF_FLAG_PREPARED;
574
575 if (vb2_buffer_in_use(q, vb))
576 b->flags |= V4L2_BUF_FLAG_MAPPED;
577 if (vbuf->request_fd >= 0) {
578 b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
579 b->request_fd = vbuf->request_fd;
580 }
581}
582
583/*
584 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
585 * v4l2_buffer by the userspace. It also verifies that struct
586 * v4l2_buffer has a valid number of planes.
587 */
588static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
589{
590 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
591 unsigned int plane;
592
593 if (!vb->vb2_queue->copy_timestamp)
594 vb->timestamp = 0;
595
596 for (plane = 0; plane < vb->num_planes; ++plane) {
597 if (vb->vb2_queue->memory != VB2_MEMORY_MMAP) {
598 planes[plane].m = vbuf->planes[plane].m;
599 planes[plane].length = vbuf->planes[plane].length;
600 }
601 planes[plane].bytesused = vbuf->planes[plane].bytesused;
602 planes[plane].data_offset = vbuf->planes[plane].data_offset;
603 }
604 return 0;
605}
606
607static const struct vb2_buf_ops v4l2_buf_ops = {
608 .verify_planes_array = __verify_planes_array_core,
609 .init_buffer = __init_vb2_v4l2_buffer,
610 .fill_user_buffer = __fill_v4l2_buffer,
611 .fill_vb2_buffer = __fill_vb2_buffer,
612 .copy_timestamp = __copy_timestamp,
613};
614
615struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)
616{
617 unsigned int i;
618 struct vb2_buffer *vb2;
619
620 /*
621 * This loop doesn't scale if there is a really large number of buffers.
622 * Maybe something more efficient will be needed in this case.
623 */
624 for (i = 0; i < q->max_num_buffers; i++) {
625 vb2 = vb2_get_buffer(q, index: i);
626
627 if (!vb2)
628 continue;
629
630 if (vb2->copied_timestamp &&
631 vb2->timestamp == timestamp)
632 return vb2;
633 }
634 return NULL;
635}
636EXPORT_SYMBOL_GPL(vb2_find_buffer);
637
638/*
639 * vb2_querybuf() - query video buffer information
640 * @q: vb2 queue
641 * @b: buffer struct passed from userspace to vidioc_querybuf handler
642 * in driver
643 *
644 * Should be called from vidioc_querybuf ioctl handler in driver.
645 * This function will verify the passed v4l2_buffer structure and fill the
646 * relevant information for the userspace.
647 *
648 * The return values from this function are intended to be directly returned
649 * from vidioc_querybuf handler in driver.
650 */
651int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
652{
653 struct vb2_buffer *vb;
654 int ret;
655
656 if (b->type != q->type) {
657 dprintk(q, 1, "wrong buffer type\n");
658 return -EINVAL;
659 }
660
661 vb = vb2_get_buffer(q, index: b->index);
662 if (!vb) {
663 dprintk(q, 1, "can't find the requested buffer %u\n", b->index);
664 return -EINVAL;
665 }
666
667 ret = __verify_planes_array(vb, b);
668 if (!ret)
669 vb2_core_querybuf(q, vb, pb: b);
670 return ret;
671}
672EXPORT_SYMBOL(vb2_querybuf);
673
674static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
675 u32 *flags, u32 *caps, u32 *max_num_bufs)
676{
677 if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) {
678 /*
679 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only,
680 * but in order to avoid bugs we zero out all bits.
681 */
682 *flags = 0;
683 } else {
684 /* Clear all unknown flags. */
685 *flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
686 }
687
688 *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
689 if (q->io_modes & VB2_MMAP)
690 *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP;
691 if (q->io_modes & VB2_USERPTR)
692 *caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;
693 if (q->io_modes & VB2_DMABUF)
694 *caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
695 if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)
696 *caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
697 if (q->allow_cache_hints && q->io_modes & VB2_MMAP)
698 *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
699 if (q->supports_requests)
700 *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
701 if (max_num_bufs) {
702 *max_num_bufs = q->max_num_buffers;
703 *caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;
704 }
705}
706
707int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
708{
709 int ret = vb2_verify_memory_type(q, memory: req->memory, type: req->type);
710 u32 flags = req->flags;
711
712 vb2_set_flags_and_caps(q, memory: req->memory, flags: &flags,
713 caps: &req->capabilities, NULL);
714 req->flags = flags;
715 return ret ? ret : vb2_core_reqbufs(q, memory: req->memory,
716 flags: req->flags, count: &req->count);
717}
718EXPORT_SYMBOL_GPL(vb2_reqbufs);
719
720int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
721 struct v4l2_buffer *b)
722{
723 struct vb2_buffer *vb;
724 int ret;
725
726 if (vb2_fileio_is_active(q)) {
727 dprintk(q, 1, "file io in progress\n");
728 return -EBUSY;
729 }
730
731 if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)
732 return -EINVAL;
733
734 vb = vb2_get_buffer(q, index: b->index);
735 if (!vb) {
736 dprintk(q, 1, "can't find the requested buffer %u\n", b->index);
737 return -EINVAL;
738 }
739
740 ret = vb2_queue_or_prepare_buf(q, mdev, vb, b, is_prepare: true, NULL);
741
742 return ret ? ret : vb2_core_prepare_buf(q, vb, pb: b);
743}
744EXPORT_SYMBOL_GPL(vb2_prepare_buf);
745
746int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
747{
748 unsigned requested_planes = 1;
749 unsigned requested_sizes[VIDEO_MAX_PLANES];
750 struct v4l2_format *f = &create->format;
751 int ret = vb2_verify_memory_type(q, memory: create->memory, type: f->type);
752 unsigned i;
753
754 create->index = vb2_get_num_buffers(q);
755 vb2_set_flags_and_caps(q, memory: create->memory, flags: &create->flags,
756 caps: &create->capabilities, max_num_bufs: &create->max_num_buffers);
757 if (create->count == 0)
758 return ret != -EBUSY ? ret : 0;
759
760 switch (f->type) {
761 case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
762 case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
763 requested_planes = f->fmt.pix_mp.num_planes;
764 if (requested_planes == 0 ||
765 requested_planes > VIDEO_MAX_PLANES)
766 return -EINVAL;
767 for (i = 0; i < requested_planes; i++)
768 requested_sizes[i] =
769 f->fmt.pix_mp.plane_fmt[i].sizeimage;
770 break;
771 case V4L2_BUF_TYPE_VIDEO_CAPTURE:
772 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
773 requested_sizes[0] = f->fmt.pix.sizeimage;
774 break;
775 case V4L2_BUF_TYPE_VBI_CAPTURE:
776 case V4L2_BUF_TYPE_VBI_OUTPUT:
777 requested_sizes[0] = f->fmt.vbi.samples_per_line *
778 (f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);
779 break;
780 case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
781 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
782 requested_sizes[0] = f->fmt.sliced.io_size;
783 break;
784 case V4L2_BUF_TYPE_SDR_CAPTURE:
785 case V4L2_BUF_TYPE_SDR_OUTPUT:
786 requested_sizes[0] = f->fmt.sdr.buffersize;
787 break;
788 case V4L2_BUF_TYPE_META_CAPTURE:
789 case V4L2_BUF_TYPE_META_OUTPUT:
790 requested_sizes[0] = f->fmt.meta.buffersize;
791 break;
792 default:
793 return -EINVAL;
794 }
795 for (i = 0; i < requested_planes; i++)
796 if (requested_sizes[i] == 0)
797 return -EINVAL;
798 return ret ? ret : vb2_core_create_bufs(q, memory: create->memory,
799 flags: create->flags,
800 count: &create->count,
801 requested_planes,
802 requested_sizes);
803}
804EXPORT_SYMBOL_GPL(vb2_create_bufs);
805
806int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
807 struct v4l2_buffer *b)
808{
809 struct media_request *req = NULL;
810 struct vb2_buffer *vb;
811 int ret;
812
813 if (vb2_fileio_is_active(q)) {
814 dprintk(q, 1, "file io in progress\n");
815 return -EBUSY;
816 }
817
818 vb = vb2_get_buffer(q, index: b->index);
819 if (!vb) {
820 dprintk(q, 1, "can't find the requested buffer %u\n", b->index);
821 return -EINVAL;
822 }
823
824 ret = vb2_queue_or_prepare_buf(q, mdev, vb, b, is_prepare: false, p_req: &req);
825 if (ret)
826 return ret;
827 ret = vb2_core_qbuf(q, vb, pb: b, req);
828 if (req)
829 media_request_put(req);
830 return ret;
831}
832EXPORT_SYMBOL_GPL(vb2_qbuf);
833
834int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
835{
836 int ret;
837
838 if (vb2_fileio_is_active(q)) {
839 dprintk(q, 1, "file io in progress\n");
840 return -EBUSY;
841 }
842
843 if (b->type != q->type) {
844 dprintk(q, 1, "invalid buffer type\n");
845 return -EINVAL;
846 }
847
848 ret = vb2_core_dqbuf(q, NULL, pb: b, nonblocking);
849
850 if (!q->is_output &&
851 b->flags & V4L2_BUF_FLAG_DONE &&
852 b->flags & V4L2_BUF_FLAG_LAST)
853 q->last_buffer_dequeued = true;
854
855 /*
856 * After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
857 * cleared.
858 */
859 b->flags &= ~V4L2_BUF_FLAG_DONE;
860
861 return ret;
862}
863EXPORT_SYMBOL_GPL(vb2_dqbuf);
864
865int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
866{
867 if (vb2_fileio_is_active(q)) {
868 dprintk(q, 1, "file io in progress\n");
869 return -EBUSY;
870 }
871 return vb2_core_streamon(q, type);
872}
873EXPORT_SYMBOL_GPL(vb2_streamon);
874
875int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
876{
877 if (vb2_fileio_is_active(q)) {
878 dprintk(q, 1, "file io in progress\n");
879 return -EBUSY;
880 }
881 return vb2_core_streamoff(q, type);
882}
883EXPORT_SYMBOL_GPL(vb2_streamoff);
884
885int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
886{
887 struct vb2_buffer *vb;
888
889 vb = vb2_get_buffer(q, index: eb->index);
890 if (!vb) {
891 dprintk(q, 1, "can't find the requested buffer %u\n", eb->index);
892 return -EINVAL;
893 }
894
895 return vb2_core_expbuf(q, fd: &eb->fd, type: eb->type, vb,
896 plane: eb->plane, flags: eb->flags);
897}
898EXPORT_SYMBOL_GPL(vb2_expbuf);
899
900int vb2_queue_init_name(struct vb2_queue *q, const char *name)
901{
902 /*
903 * Sanity check
904 */
905 if (WARN_ON(!q) ||
906 WARN_ON(q->timestamp_flags &
907 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
908 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
909 return -EINVAL;
910
911 /* Warn that the driver should choose an appropriate timestamp type */
912 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
913 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
914
915 /* Warn that vb2_memory should match with v4l2_memory */
916 if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
917 || WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
918 || WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
919 return -EINVAL;
920
921 if (q->buf_struct_size == 0)
922 q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
923
924 q->buf_ops = &v4l2_buf_ops;
925 q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
926 q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
927 q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
928 == V4L2_BUF_FLAG_TIMESTAMP_COPY;
929 /*
930 * For compatibility with vb1: if QBUF hasn't been called yet, then
931 * return EPOLLERR as well. This only affects capture queues, output
932 * queues will always initialize waiting_for_buffers to false.
933 */
934 q->quirk_poll_must_check_waiting_for_buffers = true;
935
936 if (name)
937 strscpy(q->name, name, sizeof(q->name));
938 else
939 q->name[0] = '\0';
940
941 return vb2_core_queue_init(q);
942}
943EXPORT_SYMBOL_GPL(vb2_queue_init_name);
944
945int vb2_queue_init(struct vb2_queue *q)
946{
947 return vb2_queue_init_name(q, NULL);
948}
949EXPORT_SYMBOL_GPL(vb2_queue_init);
950
951void vb2_queue_release(struct vb2_queue *q)
952{
953 vb2_core_queue_release(q);
954}
955EXPORT_SYMBOL_GPL(vb2_queue_release);
956
957int vb2_queue_change_type(struct vb2_queue *q, unsigned int type)
958{
959 if (type == q->type)
960 return 0;
961
962 if (vb2_is_busy(q))
963 return -EBUSY;
964
965 q->type = type;
966
967 return 0;
968}
969EXPORT_SYMBOL_GPL(vb2_queue_change_type);
970
971__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
972{
973 struct video_device *vfd = video_devdata(file);
974 __poll_t res;
975
976 res = vb2_core_poll(q, file, wait);
977
978 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
979 struct v4l2_fh *fh = file->private_data;
980
981 poll_wait(filp: file, wait_address: &fh->wait, p: wait);
982 if (v4l2_event_pending(fh))
983 res |= EPOLLPRI;
984 }
985
986 return res;
987}
988EXPORT_SYMBOL_GPL(vb2_poll);
989
990/*
991 * The following functions are not part of the vb2 core API, but are helper
992 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
993 * and struct vb2_ops.
994 * They contain boilerplate code that most if not all drivers have to do
995 * and so they simplify the driver code.
996 */
997
998/* vb2 ioctl helpers */
999
1000int vb2_ioctl_reqbufs(struct file *file, void *priv,
1001 struct v4l2_requestbuffers *p)
1002{
1003 struct video_device *vdev = video_devdata(file);
1004 int res = vb2_verify_memory_type(q: vdev->queue, memory: p->memory, type: p->type);
1005 u32 flags = p->flags;
1006
1007 vb2_set_flags_and_caps(q: vdev->queue, memory: p->memory, flags: &flags,
1008 caps: &p->capabilities, NULL);
1009 p->flags = flags;
1010 if (res)
1011 return res;
1012 if (vb2_queue_is_busy(q: vdev->queue, file))
1013 return -EBUSY;
1014 res = vb2_core_reqbufs(q: vdev->queue, memory: p->memory, flags: p->flags, count: &p->count);
1015 /* If count == 0, then the owner has released all buffers and he
1016 is no longer owner of the queue. Otherwise we have a new owner. */
1017 if (res == 0)
1018 vdev->queue->owner = p->count ? file->private_data : NULL;
1019 return res;
1020}
1021EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
1022
1023int vb2_ioctl_create_bufs(struct file *file, void *priv,
1024 struct v4l2_create_buffers *p)
1025{
1026 struct video_device *vdev = video_devdata(file);
1027 int res = vb2_verify_memory_type(q: vdev->queue, memory: p->memory, type: p->format.type);
1028
1029 p->index = vb2_get_num_buffers(q: vdev->queue);
1030 vb2_set_flags_and_caps(q: vdev->queue, memory: p->memory, flags: &p->flags,
1031 caps: &p->capabilities, max_num_bufs: &p->max_num_buffers);
1032 /*
1033 * If count == 0, then just check if memory and type are valid.
1034 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
1035 */
1036 if (p->count == 0)
1037 return res != -EBUSY ? res : 0;
1038 if (res)
1039 return res;
1040 if (vb2_queue_is_busy(q: vdev->queue, file))
1041 return -EBUSY;
1042
1043 res = vb2_create_bufs(vdev->queue, p);
1044 if (res == 0)
1045 vdev->queue->owner = file->private_data;
1046 return res;
1047}
1048EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
1049
1050int vb2_ioctl_prepare_buf(struct file *file, void *priv,
1051 struct v4l2_buffer *p)
1052{
1053 struct video_device *vdev = video_devdata(file);
1054
1055 if (vb2_queue_is_busy(q: vdev->queue, file))
1056 return -EBUSY;
1057 return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
1058}
1059EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
1060
1061int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
1062{
1063 struct video_device *vdev = video_devdata(file);
1064
1065 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
1066 return vb2_querybuf(vdev->queue, p);
1067}
1068EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
1069
1070int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1071{
1072 struct video_device *vdev = video_devdata(file);
1073
1074 if (vb2_queue_is_busy(q: vdev->queue, file))
1075 return -EBUSY;
1076 return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
1077}
1078EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
1079
1080int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1081{
1082 struct video_device *vdev = video_devdata(file);
1083
1084 if (vb2_queue_is_busy(q: vdev->queue, file))
1085 return -EBUSY;
1086 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
1087}
1088EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
1089
1090int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
1091{
1092 struct video_device *vdev = video_devdata(file);
1093
1094 if (vb2_queue_is_busy(q: vdev->queue, file))
1095 return -EBUSY;
1096 return vb2_streamon(vdev->queue, i);
1097}
1098EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
1099
1100int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
1101{
1102 struct video_device *vdev = video_devdata(file);
1103
1104 if (vb2_queue_is_busy(q: vdev->queue, file))
1105 return -EBUSY;
1106 return vb2_streamoff(vdev->queue, i);
1107}
1108EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
1109
1110int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
1111{
1112 struct video_device *vdev = video_devdata(file);
1113
1114 if (vb2_queue_is_busy(q: vdev->queue, file))
1115 return -EBUSY;
1116 return vb2_expbuf(vdev->queue, p);
1117}
1118EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
1119
1120/* v4l2_file_operations helpers */
1121
1122int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
1123{
1124 struct video_device *vdev = video_devdata(file);
1125
1126 return vb2_mmap(q: vdev->queue, vma);
1127}
1128EXPORT_SYMBOL_GPL(vb2_fop_mmap);
1129
1130int _vb2_fop_release(struct file *file, struct mutex *lock)
1131{
1132 struct video_device *vdev = video_devdata(file);
1133
1134 if (lock)
1135 mutex_lock(lock);
1136 if (!vdev->queue->owner || file->private_data == vdev->queue->owner) {
1137 vb2_queue_release(vdev->queue);
1138 vdev->queue->owner = NULL;
1139 }
1140 if (lock)
1141 mutex_unlock(lock);
1142 return v4l2_fh_release(filp: file);
1143}
1144EXPORT_SYMBOL_GPL(_vb2_fop_release);
1145
1146int vb2_fop_release(struct file *file)
1147{
1148 struct video_device *vdev = video_devdata(file);
1149 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1150
1151 return _vb2_fop_release(file, lock);
1152}
1153EXPORT_SYMBOL_GPL(vb2_fop_release);
1154
1155ssize_t vb2_fop_write(struct file *file, const char __user *buf,
1156 size_t count, loff_t *ppos)
1157{
1158 struct video_device *vdev = video_devdata(file);
1159 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1160 int err = -EBUSY;
1161
1162 if (!(vdev->queue->io_modes & VB2_WRITE))
1163 return -EINVAL;
1164 if (lock && mutex_lock_interruptible(lock))
1165 return -ERESTARTSYS;
1166 if (vb2_queue_is_busy(q: vdev->queue, file))
1167 goto exit;
1168 err = vb2_write(q: vdev->queue, data: buf, count, ppos,
1169 nonblock: file->f_flags & O_NONBLOCK);
1170 if (vdev->queue->fileio)
1171 vdev->queue->owner = file->private_data;
1172exit:
1173 if (lock)
1174 mutex_unlock(lock);
1175 return err;
1176}
1177EXPORT_SYMBOL_GPL(vb2_fop_write);
1178
1179ssize_t vb2_fop_read(struct file *file, char __user *buf,
1180 size_t count, loff_t *ppos)
1181{
1182 struct video_device *vdev = video_devdata(file);
1183 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1184 int err = -EBUSY;
1185
1186 if (!(vdev->queue->io_modes & VB2_READ))
1187 return -EINVAL;
1188 if (lock && mutex_lock_interruptible(lock))
1189 return -ERESTARTSYS;
1190 if (vb2_queue_is_busy(q: vdev->queue, file))
1191 goto exit;
1192 vdev->queue->owner = file->private_data;
1193 err = vb2_read(q: vdev->queue, data: buf, count, ppos,
1194 nonblock: file->f_flags & O_NONBLOCK);
1195 if (!vdev->queue->fileio)
1196 vdev->queue->owner = NULL;
1197exit:
1198 if (lock)
1199 mutex_unlock(lock);
1200 return err;
1201}
1202EXPORT_SYMBOL_GPL(vb2_fop_read);
1203
1204__poll_t vb2_fop_poll(struct file *file, poll_table *wait)
1205{
1206 struct video_device *vdev = video_devdata(file);
1207 struct vb2_queue *q = vdev->queue;
1208 struct mutex *lock = q->lock ? q->lock : vdev->lock;
1209 __poll_t res;
1210 void *fileio;
1211
1212 /*
1213 * If this helper doesn't know how to lock, then you shouldn't be using
1214 * it but you should write your own.
1215 */
1216 WARN_ON(!lock);
1217
1218 if (lock && mutex_lock_interruptible(lock))
1219 return EPOLLERR;
1220
1221 fileio = q->fileio;
1222
1223 res = vb2_poll(vdev->queue, file, wait);
1224
1225 /* If fileio was started, then we have a new queue owner. */
1226 if (!fileio && q->fileio)
1227 q->owner = file->private_data;
1228 if (lock)
1229 mutex_unlock(lock);
1230 return res;
1231}
1232EXPORT_SYMBOL_GPL(vb2_fop_poll);
1233
1234#ifndef CONFIG_MMU
1235unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
1236 unsigned long len, unsigned long pgoff, unsigned long flags)
1237{
1238 struct video_device *vdev = video_devdata(file);
1239
1240 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
1241}
1242EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
1243#endif
1244
1245void vb2_video_unregister_device(struct video_device *vdev)
1246{
1247 /* Check if vdev was ever registered at all */
1248 if (!vdev || !video_is_registered(vdev))
1249 return;
1250
1251 /*
1252 * Calling this function only makes sense if vdev->queue is set.
1253 * If it is NULL, then just call video_unregister_device() instead.
1254 */
1255 WARN_ON(!vdev->queue);
1256
1257 /*
1258 * Take a reference to the device since video_unregister_device()
1259 * calls device_unregister(), but we don't want that to release
1260 * the device since we want to clean up the queue first.
1261 */
1262 get_device(dev: &vdev->dev);
1263 video_unregister_device(vdev);
1264 if (vdev->queue) {
1265 struct mutex *lock = vdev->queue->lock ?
1266 vdev->queue->lock : vdev->lock;
1267
1268 if (lock)
1269 mutex_lock(lock);
1270 vb2_queue_release(vdev->queue);
1271 vdev->queue->owner = NULL;
1272 if (lock)
1273 mutex_unlock(lock);
1274 }
1275 /*
1276 * Now we put the device, and in most cases this will release
1277 * everything.
1278 */
1279 put_device(dev: &vdev->dev);
1280}
1281EXPORT_SYMBOL_GPL(vb2_video_unregister_device);
1282
1283/* vb2_ops helpers. Only use if vq->lock is non-NULL. */
1284
1285void vb2_ops_wait_prepare(struct vb2_queue *vq)
1286{
1287 mutex_unlock(lock: vq->lock);
1288}
1289EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
1290
1291void vb2_ops_wait_finish(struct vb2_queue *vq)
1292{
1293 mutex_lock(vq->lock);
1294}
1295EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
1296
1297/*
1298 * Note that this function is called during validation time and
1299 * thus the req_queue_mutex is held to ensure no request objects
1300 * can be added or deleted while validating. So there is no need
1301 * to protect the objects list.
1302 */
1303int vb2_request_validate(struct media_request *req)
1304{
1305 struct media_request_object *obj;
1306 int ret = 0;
1307
1308 if (!vb2_request_buffer_cnt(req))
1309 return -ENOENT;
1310
1311 list_for_each_entry(obj, &req->objects, list) {
1312 if (!obj->ops->prepare)
1313 continue;
1314
1315 ret = obj->ops->prepare(obj);
1316 if (ret)
1317 break;
1318 }
1319
1320 if (ret) {
1321 list_for_each_entry_continue_reverse(obj, &req->objects, list)
1322 if (obj->ops->unprepare)
1323 obj->ops->unprepare(obj);
1324 return ret;
1325 }
1326 return 0;
1327}
1328EXPORT_SYMBOL_GPL(vb2_request_validate);
1329
1330void vb2_request_queue(struct media_request *req)
1331{
1332 struct media_request_object *obj, *obj_safe;
1333
1334 /*
1335 * Queue all objects. Note that buffer objects are at the end of the
1336 * objects list, after all other object types. Once buffer objects
1337 * are queued, the driver might delete them immediately (if the driver
1338 * processes the buffer at once), so we have to use
1339 * list_for_each_entry_safe() to handle the case where the object we
1340 * queue is deleted.
1341 */
1342 list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
1343 if (obj->ops->queue)
1344 obj->ops->queue(obj);
1345}
1346EXPORT_SYMBOL_GPL(vb2_request_queue);
1347
1348MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
1349MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
1350MODULE_LICENSE("GPL");
1351

source code of linux/drivers/media/common/videobuf2/videobuf2-v4l2.c