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V4L/DVB (13377): make struct videobuf_queue_ops constant
[mirror_ubuntu-hirsute-kernel.git] / drivers / media / video / videobuf-core.c
1 /*
2 * generic helper functions for handling video4linux capture buffers
3 *
4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
5 *
6 * Highly based on video-buf written originally by:
7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
8 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
9 * (c) 2006 Ted Walther and John Sokol
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2
14 */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/mm.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
23
24 #include <media/videobuf-core.h>
25
26 #define MAGIC_BUFFER 0x20070728
27 #define MAGIC_CHECK(is, should) do { \
28 if (unlikely((is) != (should))) { \
29 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
30 BUG(); } } while (0)
31
32 static int debug;
33 module_param(debug, int, 0644);
34
35 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
36 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
37 MODULE_LICENSE("GPL");
38
39 #define dprintk(level, fmt, arg...) do { \
40 if (debug >= level) \
41 printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
42
43 /* --------------------------------------------------------------------- */
44
45 #define CALL(q, f, arg...) \
46 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
47
48 void *videobuf_alloc(struct videobuf_queue *q)
49 {
50 struct videobuf_buffer *vb;
51
52 BUG_ON(q->msize < sizeof(*vb));
53
54 if (!q->int_ops || !q->int_ops->alloc) {
55 printk(KERN_ERR "No specific ops defined!\n");
56 BUG();
57 }
58
59 vb = q->int_ops->alloc(q->msize);
60
61 if (NULL != vb) {
62 init_waitqueue_head(&vb->done);
63 vb->magic = MAGIC_BUFFER;
64 }
65
66 return vb;
67 }
68
69 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
70 vb->state != VIDEOBUF_QUEUED)
71 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
72 {
73 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
74
75 if (non_blocking) {
76 if (WAITON_CONDITION)
77 return 0;
78 else
79 return -EAGAIN;
80 }
81
82 if (intr)
83 return wait_event_interruptible(vb->done, WAITON_CONDITION);
84 else
85 wait_event(vb->done, WAITON_CONDITION);
86
87 return 0;
88 }
89
90 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
91 struct v4l2_framebuffer *fbuf)
92 {
93 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
94 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
95
96 return CALL(q, iolock, q, vb, fbuf);
97 }
98
99 void *videobuf_queue_to_vmalloc (struct videobuf_queue *q,
100 struct videobuf_buffer *buf)
101 {
102 if (q->int_ops->vmalloc)
103 return q->int_ops->vmalloc(buf);
104 else
105 return NULL;
106 }
107 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
108
109 /* --------------------------------------------------------------------- */
110
111
112 void videobuf_queue_core_init(struct videobuf_queue *q,
113 const struct videobuf_queue_ops *ops,
114 struct device *dev,
115 spinlock_t *irqlock,
116 enum v4l2_buf_type type,
117 enum v4l2_field field,
118 unsigned int msize,
119 void *priv,
120 struct videobuf_qtype_ops *int_ops)
121 {
122 BUG_ON(!q);
123 memset(q, 0, sizeof(*q));
124 q->irqlock = irqlock;
125 q->dev = dev;
126 q->type = type;
127 q->field = field;
128 q->msize = msize;
129 q->ops = ops;
130 q->priv_data = priv;
131 q->int_ops = int_ops;
132
133 /* All buffer operations are mandatory */
134 BUG_ON(!q->ops->buf_setup);
135 BUG_ON(!q->ops->buf_prepare);
136 BUG_ON(!q->ops->buf_queue);
137 BUG_ON(!q->ops->buf_release);
138
139 /* Lock is mandatory for queue_cancel to work */
140 BUG_ON(!irqlock);
141
142 /* Having implementations for abstract methods are mandatory */
143 BUG_ON(!q->int_ops);
144
145 mutex_init(&q->vb_lock);
146 init_waitqueue_head(&q->wait);
147 INIT_LIST_HEAD(&q->stream);
148 }
149
150 /* Locking: Only usage in bttv unsafe find way to remove */
151 int videobuf_queue_is_busy(struct videobuf_queue *q)
152 {
153 int i;
154
155 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
156
157 if (q->streaming) {
158 dprintk(1, "busy: streaming active\n");
159 return 1;
160 }
161 if (q->reading) {
162 dprintk(1, "busy: pending read #1\n");
163 return 1;
164 }
165 if (q->read_buf) {
166 dprintk(1, "busy: pending read #2\n");
167 return 1;
168 }
169 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
170 if (NULL == q->bufs[i])
171 continue;
172 if (q->bufs[i]->map) {
173 dprintk(1, "busy: buffer #%d mapped\n", i);
174 return 1;
175 }
176 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
177 dprintk(1, "busy: buffer #%d queued\n", i);
178 return 1;
179 }
180 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
181 dprintk(1, "busy: buffer #%d avtive\n", i);
182 return 1;
183 }
184 }
185 return 0;
186 }
187
188 /* Locking: Caller holds q->vb_lock */
189 void videobuf_queue_cancel(struct videobuf_queue *q)
190 {
191 unsigned long flags = 0;
192 int i;
193
194 q->streaming = 0;
195 q->reading = 0;
196 wake_up_interruptible_sync(&q->wait);
197
198 /* remove queued buffers from list */
199 spin_lock_irqsave(q->irqlock, flags);
200 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
201 if (NULL == q->bufs[i])
202 continue;
203 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
204 list_del(&q->bufs[i]->queue);
205 q->bufs[i]->state = VIDEOBUF_ERROR;
206 wake_up_all(&q->bufs[i]->done);
207 }
208 }
209 spin_unlock_irqrestore(q->irqlock, flags);
210
211 /* free all buffers + clear queue */
212 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
213 if (NULL == q->bufs[i])
214 continue;
215 q->ops->buf_release(q, q->bufs[i]);
216 }
217 INIT_LIST_HEAD(&q->stream);
218 }
219
220 /* --------------------------------------------------------------------- */
221
222 /* Locking: Caller holds q->vb_lock */
223 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
224 {
225 enum v4l2_field field = q->field;
226
227 BUG_ON(V4L2_FIELD_ANY == field);
228
229 if (V4L2_FIELD_ALTERNATE == field) {
230 if (V4L2_FIELD_TOP == q->last) {
231 field = V4L2_FIELD_BOTTOM;
232 q->last = V4L2_FIELD_BOTTOM;
233 } else {
234 field = V4L2_FIELD_TOP;
235 q->last = V4L2_FIELD_TOP;
236 }
237 }
238 return field;
239 }
240
241 /* Locking: Caller holds q->vb_lock */
242 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
243 struct videobuf_buffer *vb, enum v4l2_buf_type type)
244 {
245 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
246 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
247
248 b->index = vb->i;
249 b->type = type;
250
251 b->memory = vb->memory;
252 switch (b->memory) {
253 case V4L2_MEMORY_MMAP:
254 b->m.offset = vb->boff;
255 b->length = vb->bsize;
256 break;
257 case V4L2_MEMORY_USERPTR:
258 b->m.userptr = vb->baddr;
259 b->length = vb->bsize;
260 break;
261 case V4L2_MEMORY_OVERLAY:
262 b->m.offset = vb->boff;
263 break;
264 }
265
266 b->flags = 0;
267 if (vb->map)
268 b->flags |= V4L2_BUF_FLAG_MAPPED;
269
270 switch (vb->state) {
271 case VIDEOBUF_PREPARED:
272 case VIDEOBUF_QUEUED:
273 case VIDEOBUF_ACTIVE:
274 b->flags |= V4L2_BUF_FLAG_QUEUED;
275 break;
276 case VIDEOBUF_DONE:
277 case VIDEOBUF_ERROR:
278 b->flags |= V4L2_BUF_FLAG_DONE;
279 break;
280 case VIDEOBUF_NEEDS_INIT:
281 case VIDEOBUF_IDLE:
282 /* nothing */
283 break;
284 }
285
286 if (vb->input != UNSET) {
287 b->flags |= V4L2_BUF_FLAG_INPUT;
288 b->input = vb->input;
289 }
290
291 b->field = vb->field;
292 b->timestamp = vb->ts;
293 b->bytesused = vb->size;
294 b->sequence = vb->field_count >> 1;
295 }
296
297 /* Locking: Caller holds q->vb_lock */
298 static int __videobuf_mmap_free(struct videobuf_queue *q)
299 {
300 int i;
301 int rc;
302
303 if (!q)
304 return 0;
305
306 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
307
308
309 rc = CALL(q, mmap_free, q);
310
311 q->is_mmapped = 0;
312
313 if (rc < 0)
314 return rc;
315
316 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
317 if (NULL == q->bufs[i])
318 continue;
319 q->ops->buf_release(q, q->bufs[i]);
320 kfree(q->bufs[i]);
321 q->bufs[i] = NULL;
322 }
323
324 return rc;
325 }
326
327 int videobuf_mmap_free(struct videobuf_queue *q)
328 {
329 int ret;
330 mutex_lock(&q->vb_lock);
331 ret = __videobuf_mmap_free(q);
332 mutex_unlock(&q->vb_lock);
333 return ret;
334 }
335
336 /* Locking: Caller holds q->vb_lock */
337 int __videobuf_mmap_setup(struct videobuf_queue *q,
338 unsigned int bcount, unsigned int bsize,
339 enum v4l2_memory memory)
340 {
341 unsigned int i;
342 int err;
343
344 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
345
346 err = __videobuf_mmap_free(q);
347 if (0 != err)
348 return err;
349
350 /* Allocate and initialize buffers */
351 for (i = 0; i < bcount; i++) {
352 q->bufs[i] = videobuf_alloc(q);
353
354 if (q->bufs[i] == NULL)
355 break;
356
357 q->bufs[i]->i = i;
358 q->bufs[i]->input = UNSET;
359 q->bufs[i]->memory = memory;
360 q->bufs[i]->bsize = bsize;
361 switch (memory) {
362 case V4L2_MEMORY_MMAP:
363 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
364 break;
365 case V4L2_MEMORY_USERPTR:
366 case V4L2_MEMORY_OVERLAY:
367 /* nothing */
368 break;
369 }
370 }
371
372 if (!i)
373 return -ENOMEM;
374
375 dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
376 i, bsize);
377
378 return i;
379 }
380
381 int videobuf_mmap_setup(struct videobuf_queue *q,
382 unsigned int bcount, unsigned int bsize,
383 enum v4l2_memory memory)
384 {
385 int ret;
386 mutex_lock(&q->vb_lock);
387 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
388 mutex_unlock(&q->vb_lock);
389 return ret;
390 }
391
392 int videobuf_reqbufs(struct videobuf_queue *q,
393 struct v4l2_requestbuffers *req)
394 {
395 unsigned int size, count;
396 int retval;
397
398 if (req->count < 1) {
399 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
400 return -EINVAL;
401 }
402
403 if (req->memory != V4L2_MEMORY_MMAP &&
404 req->memory != V4L2_MEMORY_USERPTR &&
405 req->memory != V4L2_MEMORY_OVERLAY) {
406 dprintk(1, "reqbufs: memory type invalid\n");
407 return -EINVAL;
408 }
409
410 mutex_lock(&q->vb_lock);
411 if (req->type != q->type) {
412 dprintk(1, "reqbufs: queue type invalid\n");
413 retval = -EINVAL;
414 goto done;
415 }
416
417 if (q->streaming) {
418 dprintk(1, "reqbufs: streaming already exists\n");
419 retval = -EBUSY;
420 goto done;
421 }
422 if (!list_empty(&q->stream)) {
423 dprintk(1, "reqbufs: stream running\n");
424 retval = -EBUSY;
425 goto done;
426 }
427
428 count = req->count;
429 if (count > VIDEO_MAX_FRAME)
430 count = VIDEO_MAX_FRAME;
431 size = 0;
432 q->ops->buf_setup(q, &count, &size);
433 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
434 count, size, (count*PAGE_ALIGN(size))>>PAGE_SHIFT);
435
436 retval = __videobuf_mmap_setup(q, count, size, req->memory);
437 if (retval < 0) {
438 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
439 goto done;
440 }
441
442 req->count = retval;
443 retval = 0;
444
445 done:
446 mutex_unlock(&q->vb_lock);
447 return retval;
448 }
449
450 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
451 {
452 int ret = -EINVAL;
453
454 mutex_lock(&q->vb_lock);
455 if (unlikely(b->type != q->type)) {
456 dprintk(1, "querybuf: Wrong type.\n");
457 goto done;
458 }
459 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
460 dprintk(1, "querybuf: index out of range.\n");
461 goto done;
462 }
463 if (unlikely(NULL == q->bufs[b->index])) {
464 dprintk(1, "querybuf: buffer is null.\n");
465 goto done;
466 }
467
468 videobuf_status(q, b, q->bufs[b->index], q->type);
469
470 ret = 0;
471 done:
472 mutex_unlock(&q->vb_lock);
473 return ret;
474 }
475
476 int videobuf_qbuf(struct videobuf_queue *q,
477 struct v4l2_buffer *b)
478 {
479 struct videobuf_buffer *buf;
480 enum v4l2_field field;
481 unsigned long flags = 0;
482 int retval;
483
484 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
485
486 if (b->memory == V4L2_MEMORY_MMAP)
487 down_read(&current->mm->mmap_sem);
488
489 mutex_lock(&q->vb_lock);
490 retval = -EBUSY;
491 if (q->reading) {
492 dprintk(1, "qbuf: Reading running...\n");
493 goto done;
494 }
495 retval = -EINVAL;
496 if (b->type != q->type) {
497 dprintk(1, "qbuf: Wrong type.\n");
498 goto done;
499 }
500 if (b->index >= VIDEO_MAX_FRAME) {
501 dprintk(1, "qbuf: index out of range.\n");
502 goto done;
503 }
504 buf = q->bufs[b->index];
505 if (NULL == buf) {
506 dprintk(1, "qbuf: buffer is null.\n");
507 goto done;
508 }
509 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
510 if (buf->memory != b->memory) {
511 dprintk(1, "qbuf: memory type is wrong.\n");
512 goto done;
513 }
514 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
515 dprintk(1, "qbuf: buffer is already queued or active.\n");
516 goto done;
517 }
518
519 if (b->flags & V4L2_BUF_FLAG_INPUT) {
520 if (b->input >= q->inputs) {
521 dprintk(1, "qbuf: wrong input.\n");
522 goto done;
523 }
524 buf->input = b->input;
525 } else {
526 buf->input = UNSET;
527 }
528
529 switch (b->memory) {
530 case V4L2_MEMORY_MMAP:
531 if (0 == buf->baddr) {
532 dprintk(1, "qbuf: mmap requested "
533 "but buffer addr is zero!\n");
534 goto done;
535 }
536 break;
537 case V4L2_MEMORY_USERPTR:
538 if (b->length < buf->bsize) {
539 dprintk(1, "qbuf: buffer length is not enough\n");
540 goto done;
541 }
542 if (VIDEOBUF_NEEDS_INIT != buf->state &&
543 buf->baddr != b->m.userptr)
544 q->ops->buf_release(q, buf);
545 buf->baddr = b->m.userptr;
546 break;
547 case V4L2_MEMORY_OVERLAY:
548 buf->boff = b->m.offset;
549 break;
550 default:
551 dprintk(1, "qbuf: wrong memory type\n");
552 goto done;
553 }
554
555 dprintk(1, "qbuf: requesting next field\n");
556 field = videobuf_next_field(q);
557 retval = q->ops->buf_prepare(q, buf, field);
558 if (0 != retval) {
559 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
560 goto done;
561 }
562
563 list_add_tail(&buf->stream, &q->stream);
564 if (q->streaming) {
565 spin_lock_irqsave(q->irqlock, flags);
566 q->ops->buf_queue(q, buf);
567 spin_unlock_irqrestore(q->irqlock, flags);
568 }
569 dprintk(1, "qbuf: succeded\n");
570 retval = 0;
571 wake_up_interruptible_sync(&q->wait);
572
573 done:
574 mutex_unlock(&q->vb_lock);
575
576 if (b->memory == V4L2_MEMORY_MMAP)
577 up_read(&current->mm->mmap_sem);
578
579 return retval;
580 }
581
582
583 /* Locking: Caller holds q->vb_lock */
584 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
585 {
586 int retval;
587
588 checks:
589 if (!q->streaming) {
590 dprintk(1, "next_buffer: Not streaming\n");
591 retval = -EINVAL;
592 goto done;
593 }
594
595 if (list_empty(&q->stream)) {
596 if (noblock) {
597 retval = -EAGAIN;
598 dprintk(2, "next_buffer: no buffers to dequeue\n");
599 goto done;
600 } else {
601 dprintk(2, "next_buffer: waiting on buffer\n");
602
603 /* Drop lock to avoid deadlock with qbuf */
604 mutex_unlock(&q->vb_lock);
605
606 /* Checking list_empty and streaming is safe without
607 * locks because we goto checks to validate while
608 * holding locks before proceeding */
609 retval = wait_event_interruptible(q->wait,
610 !list_empty(&q->stream) || !q->streaming);
611 mutex_lock(&q->vb_lock);
612
613 if (retval)
614 goto done;
615
616 goto checks;
617 }
618 }
619
620 retval = 0;
621
622 done:
623 return retval;
624 }
625
626
627 /* Locking: Caller holds q->vb_lock */
628 static int stream_next_buffer(struct videobuf_queue *q,
629 struct videobuf_buffer **vb, int nonblocking)
630 {
631 int retval;
632 struct videobuf_buffer *buf = NULL;
633
634 retval = stream_next_buffer_check_queue(q, nonblocking);
635 if (retval)
636 goto done;
637
638 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
639 retval = videobuf_waiton(buf, nonblocking, 1);
640 if (retval < 0)
641 goto done;
642
643 *vb = buf;
644 done:
645 return retval;
646 }
647
648 int videobuf_dqbuf(struct videobuf_queue *q,
649 struct v4l2_buffer *b, int nonblocking)
650 {
651 struct videobuf_buffer *buf = NULL;
652 int retval;
653
654 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
655
656 mutex_lock(&q->vb_lock);
657
658 retval = stream_next_buffer(q, &buf, nonblocking);
659 if (retval < 0) {
660 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
661 goto done;
662 }
663
664 switch (buf->state) {
665 case VIDEOBUF_ERROR:
666 dprintk(1, "dqbuf: state is error\n");
667 retval = -EIO;
668 CALL(q, sync, q, buf);
669 buf->state = VIDEOBUF_IDLE;
670 break;
671 case VIDEOBUF_DONE:
672 dprintk(1, "dqbuf: state is done\n");
673 CALL(q, sync, q, buf);
674 buf->state = VIDEOBUF_IDLE;
675 break;
676 default:
677 dprintk(1, "dqbuf: state invalid\n");
678 retval = -EINVAL;
679 goto done;
680 }
681 list_del(&buf->stream);
682 memset(b, 0, sizeof(*b));
683 videobuf_status(q, b, buf, q->type);
684
685 done:
686 mutex_unlock(&q->vb_lock);
687 return retval;
688 }
689
690 int videobuf_streamon(struct videobuf_queue *q)
691 {
692 struct videobuf_buffer *buf;
693 unsigned long flags = 0;
694 int retval;
695
696 mutex_lock(&q->vb_lock);
697 retval = -EBUSY;
698 if (q->reading)
699 goto done;
700 retval = 0;
701 if (q->streaming)
702 goto done;
703 q->streaming = 1;
704 spin_lock_irqsave(q->irqlock, flags);
705 list_for_each_entry(buf, &q->stream, stream)
706 if (buf->state == VIDEOBUF_PREPARED)
707 q->ops->buf_queue(q, buf);
708 spin_unlock_irqrestore(q->irqlock, flags);
709
710 wake_up_interruptible_sync(&q->wait);
711 done:
712 mutex_unlock(&q->vb_lock);
713 return retval;
714 }
715
716 /* Locking: Caller holds q->vb_lock */
717 static int __videobuf_streamoff(struct videobuf_queue *q)
718 {
719 if (!q->streaming)
720 return -EINVAL;
721
722 videobuf_queue_cancel(q);
723
724 return 0;
725 }
726
727 int videobuf_streamoff(struct videobuf_queue *q)
728 {
729 int retval;
730
731 mutex_lock(&q->vb_lock);
732 retval = __videobuf_streamoff(q);
733 mutex_unlock(&q->vb_lock);
734
735 return retval;
736 }
737
738 /* Locking: Caller holds q->vb_lock */
739 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
740 char __user *data,
741 size_t count, loff_t *ppos)
742 {
743 enum v4l2_field field;
744 unsigned long flags = 0;
745 int retval;
746
747 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
748
749 /* setup stuff */
750 q->read_buf = videobuf_alloc(q);
751 if (NULL == q->read_buf)
752 return -ENOMEM;
753
754 q->read_buf->memory = V4L2_MEMORY_USERPTR;
755 q->read_buf->baddr = (unsigned long)data;
756 q->read_buf->bsize = count;
757
758 field = videobuf_next_field(q);
759 retval = q->ops->buf_prepare(q, q->read_buf, field);
760 if (0 != retval)
761 goto done;
762
763 /* start capture & wait */
764 spin_lock_irqsave(q->irqlock, flags);
765 q->ops->buf_queue(q, q->read_buf);
766 spin_unlock_irqrestore(q->irqlock, flags);
767 retval = videobuf_waiton(q->read_buf, 0, 0);
768 if (0 == retval) {
769 CALL(q, sync, q, q->read_buf);
770 if (VIDEOBUF_ERROR == q->read_buf->state)
771 retval = -EIO;
772 else
773 retval = q->read_buf->size;
774 }
775
776 done:
777 /* cleanup */
778 q->ops->buf_release(q, q->read_buf);
779 kfree(q->read_buf);
780 q->read_buf = NULL;
781 return retval;
782 }
783
784 ssize_t videobuf_read_one(struct videobuf_queue *q,
785 char __user *data, size_t count, loff_t *ppos,
786 int nonblocking)
787 {
788 enum v4l2_field field;
789 unsigned long flags = 0;
790 unsigned size = 0, nbufs = 1;
791 int retval;
792
793 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
794
795 mutex_lock(&q->vb_lock);
796
797 q->ops->buf_setup(q, &nbufs, &size);
798
799 if (NULL == q->read_buf &&
800 count >= size &&
801 !nonblocking) {
802 retval = videobuf_read_zerocopy(q, data, count, ppos);
803 if (retval >= 0 || retval == -EIO)
804 /* ok, all done */
805 goto done;
806 /* fallback to kernel bounce buffer on failures */
807 }
808
809 if (NULL == q->read_buf) {
810 /* need to capture a new frame */
811 retval = -ENOMEM;
812 q->read_buf = videobuf_alloc(q);
813
814 dprintk(1, "video alloc=0x%p\n", q->read_buf);
815 if (NULL == q->read_buf)
816 goto done;
817 q->read_buf->memory = V4L2_MEMORY_USERPTR;
818 q->read_buf->bsize = count; /* preferred size */
819 field = videobuf_next_field(q);
820 retval = q->ops->buf_prepare(q, q->read_buf, field);
821
822 if (0 != retval) {
823 kfree(q->read_buf);
824 q->read_buf = NULL;
825 goto done;
826 }
827
828 spin_lock_irqsave(q->irqlock, flags);
829 q->ops->buf_queue(q, q->read_buf);
830 spin_unlock_irqrestore(q->irqlock, flags);
831
832 q->read_off = 0;
833 }
834
835 /* wait until capture is done */
836 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
837 if (0 != retval)
838 goto done;
839
840 CALL(q, sync, q, q->read_buf);
841
842 if (VIDEOBUF_ERROR == q->read_buf->state) {
843 /* catch I/O errors */
844 q->ops->buf_release(q, q->read_buf);
845 kfree(q->read_buf);
846 q->read_buf = NULL;
847 retval = -EIO;
848 goto done;
849 }
850
851 /* Copy to userspace */
852 retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
853 if (retval < 0)
854 goto done;
855
856 q->read_off += retval;
857 if (q->read_off == q->read_buf->size) {
858 /* all data copied, cleanup */
859 q->ops->buf_release(q, q->read_buf);
860 kfree(q->read_buf);
861 q->read_buf = NULL;
862 }
863
864 done:
865 mutex_unlock(&q->vb_lock);
866 return retval;
867 }
868
869 /* Locking: Caller holds q->vb_lock */
870 static int __videobuf_read_start(struct videobuf_queue *q)
871 {
872 enum v4l2_field field;
873 unsigned long flags = 0;
874 unsigned int count = 0, size = 0;
875 int err, i;
876
877 q->ops->buf_setup(q, &count, &size);
878 if (count < 2)
879 count = 2;
880 if (count > VIDEO_MAX_FRAME)
881 count = VIDEO_MAX_FRAME;
882 size = PAGE_ALIGN(size);
883
884 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
885 if (err < 0)
886 return err;
887
888 count = err;
889
890 for (i = 0; i < count; i++) {
891 field = videobuf_next_field(q);
892 err = q->ops->buf_prepare(q, q->bufs[i], field);
893 if (err)
894 return err;
895 list_add_tail(&q->bufs[i]->stream, &q->stream);
896 }
897 spin_lock_irqsave(q->irqlock, flags);
898 for (i = 0; i < count; i++)
899 q->ops->buf_queue(q, q->bufs[i]);
900 spin_unlock_irqrestore(q->irqlock, flags);
901 q->reading = 1;
902 return 0;
903 }
904
905 static void __videobuf_read_stop(struct videobuf_queue *q)
906 {
907 int i;
908
909 videobuf_queue_cancel(q);
910 __videobuf_mmap_free(q);
911 INIT_LIST_HEAD(&q->stream);
912 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
913 if (NULL == q->bufs[i])
914 continue;
915 kfree(q->bufs[i]);
916 q->bufs[i] = NULL;
917 }
918 q->read_buf = NULL;
919
920 }
921
922 int videobuf_read_start(struct videobuf_queue *q)
923 {
924 int rc;
925
926 mutex_lock(&q->vb_lock);
927 rc = __videobuf_read_start(q);
928 mutex_unlock(&q->vb_lock);
929
930 return rc;
931 }
932
933 void videobuf_read_stop(struct videobuf_queue *q)
934 {
935 mutex_lock(&q->vb_lock);
936 __videobuf_read_stop(q);
937 mutex_unlock(&q->vb_lock);
938 }
939
940 void videobuf_stop(struct videobuf_queue *q)
941 {
942 mutex_lock(&q->vb_lock);
943
944 if (q->streaming)
945 __videobuf_streamoff(q);
946
947 if (q->reading)
948 __videobuf_read_stop(q);
949
950 mutex_unlock(&q->vb_lock);
951 }
952
953
954 ssize_t videobuf_read_stream(struct videobuf_queue *q,
955 char __user *data, size_t count, loff_t *ppos,
956 int vbihack, int nonblocking)
957 {
958 int rc, retval;
959 unsigned long flags = 0;
960
961 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
962
963 dprintk(2, "%s\n", __func__);
964 mutex_lock(&q->vb_lock);
965 retval = -EBUSY;
966 if (q->streaming)
967 goto done;
968 if (!q->reading) {
969 retval = __videobuf_read_start(q);
970 if (retval < 0)
971 goto done;
972 }
973
974 retval = 0;
975 while (count > 0) {
976 /* get / wait for data */
977 if (NULL == q->read_buf) {
978 q->read_buf = list_entry(q->stream.next,
979 struct videobuf_buffer,
980 stream);
981 list_del(&q->read_buf->stream);
982 q->read_off = 0;
983 }
984 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
985 if (rc < 0) {
986 if (0 == retval)
987 retval = rc;
988 break;
989 }
990
991 if (q->read_buf->state == VIDEOBUF_DONE) {
992 rc = CALL(q, copy_stream, q, data + retval, count,
993 retval, vbihack, nonblocking);
994 if (rc < 0) {
995 retval = rc;
996 break;
997 }
998 retval += rc;
999 count -= rc;
1000 q->read_off += rc;
1001 } else {
1002 /* some error */
1003 q->read_off = q->read_buf->size;
1004 if (0 == retval)
1005 retval = -EIO;
1006 }
1007
1008 /* requeue buffer when done with copying */
1009 if (q->read_off == q->read_buf->size) {
1010 list_add_tail(&q->read_buf->stream,
1011 &q->stream);
1012 spin_lock_irqsave(q->irqlock, flags);
1013 q->ops->buf_queue(q, q->read_buf);
1014 spin_unlock_irqrestore(q->irqlock, flags);
1015 q->read_buf = NULL;
1016 }
1017 if (retval < 0)
1018 break;
1019 }
1020
1021 done:
1022 mutex_unlock(&q->vb_lock);
1023 return retval;
1024 }
1025
1026 unsigned int videobuf_poll_stream(struct file *file,
1027 struct videobuf_queue *q,
1028 poll_table *wait)
1029 {
1030 struct videobuf_buffer *buf = NULL;
1031 unsigned int rc = 0;
1032
1033 mutex_lock(&q->vb_lock);
1034 if (q->streaming) {
1035 if (!list_empty(&q->stream))
1036 buf = list_entry(q->stream.next,
1037 struct videobuf_buffer, stream);
1038 } else {
1039 if (!q->reading)
1040 __videobuf_read_start(q);
1041 if (!q->reading) {
1042 rc = POLLERR;
1043 } else if (NULL == q->read_buf) {
1044 q->read_buf = list_entry(q->stream.next,
1045 struct videobuf_buffer,
1046 stream);
1047 list_del(&q->read_buf->stream);
1048 q->read_off = 0;
1049 }
1050 buf = q->read_buf;
1051 }
1052 if (!buf)
1053 rc = POLLERR;
1054
1055 if (0 == rc) {
1056 poll_wait(file, &buf->done, wait);
1057 if (buf->state == VIDEOBUF_DONE ||
1058 buf->state == VIDEOBUF_ERROR)
1059 rc = POLLIN|POLLRDNORM;
1060 }
1061 mutex_unlock(&q->vb_lock);
1062 return rc;
1063 }
1064
1065 int videobuf_mmap_mapper(struct videobuf_queue *q,
1066 struct vm_area_struct *vma)
1067 {
1068 int retval;
1069
1070 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1071
1072 mutex_lock(&q->vb_lock);
1073 retval = CALL(q, mmap_mapper, q, vma);
1074 q->is_mmapped = 1;
1075 mutex_unlock(&q->vb_lock);
1076
1077 return retval;
1078 }
1079
1080 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1081 int videobuf_cgmbuf(struct videobuf_queue *q,
1082 struct video_mbuf *mbuf, int count)
1083 {
1084 struct v4l2_requestbuffers req;
1085 int rc, i;
1086
1087 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1088
1089 memset(&req, 0, sizeof(req));
1090 req.type = q->type;
1091 req.count = count;
1092 req.memory = V4L2_MEMORY_MMAP;
1093 rc = videobuf_reqbufs(q, &req);
1094 if (rc < 0)
1095 return rc;
1096
1097 mbuf->frames = req.count;
1098 mbuf->size = 0;
1099 for (i = 0; i < mbuf->frames; i++) {
1100 mbuf->offsets[i] = q->bufs[i]->boff;
1101 mbuf->size += PAGE_ALIGN(q->bufs[i]->bsize);
1102 }
1103
1104 return 0;
1105 }
1106 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1107 #endif
1108
1109 /* --------------------------------------------------------------------- */
1110
1111 EXPORT_SYMBOL_GPL(videobuf_waiton);
1112 EXPORT_SYMBOL_GPL(videobuf_iolock);
1113
1114 EXPORT_SYMBOL_GPL(videobuf_alloc);
1115
1116 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1117 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1118 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1119
1120 EXPORT_SYMBOL_GPL(videobuf_next_field);
1121 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1122 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1123 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1124 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1125 EXPORT_SYMBOL_GPL(videobuf_streamon);
1126 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1127
1128 EXPORT_SYMBOL_GPL(videobuf_read_start);
1129 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1130 EXPORT_SYMBOL_GPL(videobuf_stop);
1131 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1132 EXPORT_SYMBOL_GPL(videobuf_read_one);
1133 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1134
1135 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
1136 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1137 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1138 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
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