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848a2d0e1233908c051d87a9338e29c3835563fd
[deliverable/linux.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/slab.h>
20 #include <linux/interrupt.h>
21
22 #include <media/videobuf-core.h>
23
24 #define MAGIC_BUFFER 0x20070728
25 #define MAGIC_CHECK(is, should) do { \
26 if (unlikely((is) != (should))) { \
27 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
28 BUG(); } } while (0)
29
30 static int debug;
31 module_param(debug, int, 0644);
32
33 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
34 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
35 MODULE_LICENSE("GPL");
36
37 #define dprintk(level, fmt, arg...) do { \
38 if (debug >= level) \
39 printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
40
41 /* --------------------------------------------------------------------- */
42
43 #define CALL(q, f, arg...) \
44 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
45
46 void *videobuf_alloc(struct videobuf_queue *q)
47 {
48 struct videobuf_buffer *vb;
49
50 BUG_ON(q->msize < sizeof(*vb));
51
52 if (!q->int_ops || !q->int_ops->alloc) {
53 printk(KERN_ERR "No specific ops defined!\n");
54 BUG();
55 }
56
57 vb = q->int_ops->alloc(q->msize);
58
59 if (NULL != vb) {
60 init_waitqueue_head(&vb->done);
61 vb->magic = MAGIC_BUFFER;
62 }
63
64 return vb;
65 }
66
67 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
68 vb->state != VIDEOBUF_QUEUED)
69 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
70 {
71 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
72
73 if (non_blocking) {
74 if (WAITON_CONDITION)
75 return 0;
76 else
77 return -EAGAIN;
78 }
79
80 if (intr)
81 return wait_event_interruptible(vb->done, WAITON_CONDITION);
82 else
83 wait_event(vb->done, WAITON_CONDITION);
84
85 return 0;
86 }
87
88 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
89 struct v4l2_framebuffer *fbuf)
90 {
91 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
92 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
93
94 return CALL(q, iolock, q, vb, fbuf);
95 }
96
97 /* --------------------------------------------------------------------- */
98
99
100 void videobuf_queue_core_init(struct videobuf_queue *q,
101 struct videobuf_queue_ops *ops,
102 struct device *dev,
103 spinlock_t *irqlock,
104 enum v4l2_buf_type type,
105 enum v4l2_field field,
106 unsigned int msize,
107 void *priv,
108 struct videobuf_qtype_ops *int_ops)
109 {
110 memset(q, 0, sizeof(*q));
111 q->irqlock = irqlock;
112 q->dev = dev;
113 q->type = type;
114 q->field = field;
115 q->msize = msize;
116 q->ops = ops;
117 q->priv_data = priv;
118 q->int_ops = int_ops;
119
120 /* All buffer operations are mandatory */
121 BUG_ON(!q->ops->buf_setup);
122 BUG_ON(!q->ops->buf_prepare);
123 BUG_ON(!q->ops->buf_queue);
124 BUG_ON(!q->ops->buf_release);
125
126 /* Lock is mandatory for queue_cancel to work */
127 BUG_ON(!irqlock);
128
129 /* Having implementations for abstract methods are mandatory */
130 BUG_ON(!q->int_ops);
131
132 mutex_init(&q->vb_lock);
133 init_waitqueue_head(&q->wait);
134 INIT_LIST_HEAD(&q->stream);
135 }
136
137 /* Locking: Only usage in bttv unsafe find way to remove */
138 int videobuf_queue_is_busy(struct videobuf_queue *q)
139 {
140 int i;
141
142 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
143
144 if (q->streaming) {
145 dprintk(1, "busy: streaming active\n");
146 return 1;
147 }
148 if (q->reading) {
149 dprintk(1, "busy: pending read #1\n");
150 return 1;
151 }
152 if (q->read_buf) {
153 dprintk(1, "busy: pending read #2\n");
154 return 1;
155 }
156 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
157 if (NULL == q->bufs[i])
158 continue;
159 if (q->bufs[i]->map) {
160 dprintk(1, "busy: buffer #%d mapped\n", i);
161 return 1;
162 }
163 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
164 dprintk(1, "busy: buffer #%d queued\n", i);
165 return 1;
166 }
167 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
168 dprintk(1, "busy: buffer #%d avtive\n", i);
169 return 1;
170 }
171 }
172 return 0;
173 }
174
175 /* Locking: Caller holds q->vb_lock */
176 void videobuf_queue_cancel(struct videobuf_queue *q)
177 {
178 unsigned long flags = 0;
179 int i;
180
181 q->streaming = 0;
182 q->reading = 0;
183 wake_up_interruptible_sync(&q->wait);
184
185 /* remove queued buffers from list */
186 spin_lock_irqsave(q->irqlock, flags);
187 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
188 if (NULL == q->bufs[i])
189 continue;
190 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
191 list_del(&q->bufs[i]->queue);
192 q->bufs[i]->state = VIDEOBUF_ERROR;
193 wake_up_all(&q->bufs[i]->done);
194 }
195 }
196 spin_unlock_irqrestore(q->irqlock, flags);
197
198 /* free all buffers + clear queue */
199 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
200 if (NULL == q->bufs[i])
201 continue;
202 q->ops->buf_release(q, q->bufs[i]);
203 }
204 INIT_LIST_HEAD(&q->stream);
205 }
206
207 /* --------------------------------------------------------------------- */
208
209 /* Locking: Caller holds q->vb_lock */
210 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
211 {
212 enum v4l2_field field = q->field;
213
214 BUG_ON(V4L2_FIELD_ANY == field);
215
216 if (V4L2_FIELD_ALTERNATE == field) {
217 if (V4L2_FIELD_TOP == q->last) {
218 field = V4L2_FIELD_BOTTOM;
219 q->last = V4L2_FIELD_BOTTOM;
220 } else {
221 field = V4L2_FIELD_TOP;
222 q->last = V4L2_FIELD_TOP;
223 }
224 }
225 return field;
226 }
227
228 /* Locking: Caller holds q->vb_lock */
229 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
230 struct videobuf_buffer *vb, enum v4l2_buf_type type)
231 {
232 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
233 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
234
235 b->index = vb->i;
236 b->type = type;
237
238 b->memory = vb->memory;
239 switch (b->memory) {
240 case V4L2_MEMORY_MMAP:
241 b->m.offset = vb->boff;
242 b->length = vb->bsize;
243 break;
244 case V4L2_MEMORY_USERPTR:
245 b->m.userptr = vb->baddr;
246 b->length = vb->bsize;
247 break;
248 case V4L2_MEMORY_OVERLAY:
249 b->m.offset = vb->boff;
250 break;
251 }
252
253 b->flags = 0;
254 if (vb->map)
255 b->flags |= V4L2_BUF_FLAG_MAPPED;
256
257 switch (vb->state) {
258 case VIDEOBUF_PREPARED:
259 case VIDEOBUF_QUEUED:
260 case VIDEOBUF_ACTIVE:
261 b->flags |= V4L2_BUF_FLAG_QUEUED;
262 break;
263 case VIDEOBUF_DONE:
264 case VIDEOBUF_ERROR:
265 b->flags |= V4L2_BUF_FLAG_DONE;
266 break;
267 case VIDEOBUF_NEEDS_INIT:
268 case VIDEOBUF_IDLE:
269 /* nothing */
270 break;
271 }
272
273 if (vb->input != UNSET) {
274 b->flags |= V4L2_BUF_FLAG_INPUT;
275 b->input = vb->input;
276 }
277
278 b->field = vb->field;
279 b->timestamp = vb->ts;
280 b->bytesused = vb->size;
281 b->sequence = vb->field_count >> 1;
282 }
283
284 /* Locking: Caller holds q->vb_lock */
285 static int __videobuf_mmap_free(struct videobuf_queue *q)
286 {
287 int i;
288 int rc;
289
290 if (!q)
291 return 0;
292
293 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
294
295
296 rc = CALL(q, mmap_free, q);
297
298 q->is_mmapped = 0;
299
300 if (rc < 0)
301 return rc;
302
303 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
304 if (NULL == q->bufs[i])
305 continue;
306 q->ops->buf_release(q, q->bufs[i]);
307 kfree(q->bufs[i]);
308 q->bufs[i] = NULL;
309 }
310
311 return rc;
312 }
313
314 int videobuf_mmap_free(struct videobuf_queue *q)
315 {
316 int ret;
317 mutex_lock(&q->vb_lock);
318 ret = __videobuf_mmap_free(q);
319 mutex_unlock(&q->vb_lock);
320 return ret;
321 }
322
323 /* Locking: Caller holds q->vb_lock */
324 static int __videobuf_mmap_setup(struct videobuf_queue *q,
325 unsigned int bcount, unsigned int bsize,
326 enum v4l2_memory memory)
327 {
328 unsigned int i;
329 int err;
330
331 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
332
333 err = __videobuf_mmap_free(q);
334 if (0 != err)
335 return err;
336
337 /* Allocate and initialize buffers */
338 for (i = 0; i < bcount; i++) {
339 q->bufs[i] = videobuf_alloc(q);
340
341 if (q->bufs[i] == NULL)
342 break;
343
344 q->bufs[i]->i = i;
345 q->bufs[i]->input = UNSET;
346 q->bufs[i]->memory = memory;
347 q->bufs[i]->bsize = bsize;
348 switch (memory) {
349 case V4L2_MEMORY_MMAP:
350 q->bufs[i]->boff = bsize * i;
351 break;
352 case V4L2_MEMORY_USERPTR:
353 case V4L2_MEMORY_OVERLAY:
354 /* nothing */
355 break;
356 }
357 }
358
359 if (!i)
360 return -ENOMEM;
361
362 dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
363 i, bsize);
364
365 return i;
366 }
367
368 int videobuf_mmap_setup(struct videobuf_queue *q,
369 unsigned int bcount, unsigned int bsize,
370 enum v4l2_memory memory)
371 {
372 int ret;
373 mutex_lock(&q->vb_lock);
374 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
375 mutex_unlock(&q->vb_lock);
376 return ret;
377 }
378
379 int videobuf_reqbufs(struct videobuf_queue *q,
380 struct v4l2_requestbuffers *req)
381 {
382 unsigned int size, count;
383 int retval;
384
385 if (req->count < 1) {
386 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
387 return -EINVAL;
388 }
389
390 if (req->memory != V4L2_MEMORY_MMAP &&
391 req->memory != V4L2_MEMORY_USERPTR &&
392 req->memory != V4L2_MEMORY_OVERLAY) {
393 dprintk(1, "reqbufs: memory type invalid\n");
394 return -EINVAL;
395 }
396
397 mutex_lock(&q->vb_lock);
398 if (req->type != q->type) {
399 dprintk(1, "reqbufs: queue type invalid\n");
400 retval = -EINVAL;
401 goto done;
402 }
403
404 if (q->streaming) {
405 dprintk(1, "reqbufs: streaming already exists\n");
406 retval = -EBUSY;
407 goto done;
408 }
409 if (!list_empty(&q->stream)) {
410 dprintk(1, "reqbufs: stream running\n");
411 retval = -EBUSY;
412 goto done;
413 }
414
415 count = req->count;
416 if (count > VIDEO_MAX_FRAME)
417 count = VIDEO_MAX_FRAME;
418 size = 0;
419 q->ops->buf_setup(q, &count, &size);
420 size = PAGE_ALIGN(size);
421 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
422 count, size, (count*size)>>PAGE_SHIFT);
423
424 retval = __videobuf_mmap_setup(q, count, size, req->memory);
425 if (retval < 0) {
426 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
427 goto done;
428 }
429
430 req->count = retval;
431
432 done:
433 mutex_unlock(&q->vb_lock);
434 return retval;
435 }
436
437 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
438 {
439 int ret = -EINVAL;
440
441 mutex_lock(&q->vb_lock);
442 if (unlikely(b->type != q->type)) {
443 dprintk(1, "querybuf: Wrong type.\n");
444 goto done;
445 }
446 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
447 dprintk(1, "querybuf: index out of range.\n");
448 goto done;
449 }
450 if (unlikely(NULL == q->bufs[b->index])) {
451 dprintk(1, "querybuf: buffer is null.\n");
452 goto done;
453 }
454
455 videobuf_status(q, b, q->bufs[b->index], q->type);
456
457 ret = 0;
458 done:
459 mutex_unlock(&q->vb_lock);
460 return ret;
461 }
462
463 int videobuf_qbuf(struct videobuf_queue *q,
464 struct v4l2_buffer *b)
465 {
466 struct videobuf_buffer *buf;
467 enum v4l2_field field;
468 unsigned long flags = 0;
469 int retval;
470
471 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
472
473 if (b->memory == V4L2_MEMORY_MMAP)
474 down_read(&current->mm->mmap_sem);
475
476 mutex_lock(&q->vb_lock);
477 retval = -EBUSY;
478 if (q->reading) {
479 dprintk(1, "qbuf: Reading running...\n");
480 goto done;
481 }
482 retval = -EINVAL;
483 if (b->type != q->type) {
484 dprintk(1, "qbuf: Wrong type.\n");
485 goto done;
486 }
487 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
488 dprintk(1, "qbuf: index out of range.\n");
489 goto done;
490 }
491 buf = q->bufs[b->index];
492 if (NULL == buf) {
493 dprintk(1, "qbuf: buffer is null.\n");
494 goto done;
495 }
496 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
497 if (buf->memory != b->memory) {
498 dprintk(1, "qbuf: memory type is wrong.\n");
499 goto done;
500 }
501 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
502 dprintk(1, "qbuf: buffer is already queued or active.\n");
503 goto done;
504 }
505
506 if (b->flags & V4L2_BUF_FLAG_INPUT) {
507 if (b->input >= q->inputs) {
508 dprintk(1, "qbuf: wrong input.\n");
509 goto done;
510 }
511 buf->input = b->input;
512 } else {
513 buf->input = UNSET;
514 }
515
516 switch (b->memory) {
517 case V4L2_MEMORY_MMAP:
518 if (0 == buf->baddr) {
519 dprintk(1, "qbuf: mmap requested "
520 "but buffer addr is zero!\n");
521 goto done;
522 }
523 break;
524 case V4L2_MEMORY_USERPTR:
525 if (b->length < buf->bsize) {
526 dprintk(1, "qbuf: buffer length is not enough\n");
527 goto done;
528 }
529 if (VIDEOBUF_NEEDS_INIT != buf->state &&
530 buf->baddr != b->m.userptr)
531 q->ops->buf_release(q, buf);
532 buf->baddr = b->m.userptr;
533 break;
534 case V4L2_MEMORY_OVERLAY:
535 buf->boff = b->m.offset;
536 break;
537 default:
538 dprintk(1, "qbuf: wrong memory type\n");
539 goto done;
540 }
541
542 dprintk(1, "qbuf: requesting next field\n");
543 field = videobuf_next_field(q);
544 retval = q->ops->buf_prepare(q, buf, field);
545 if (0 != retval) {
546 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
547 goto done;
548 }
549
550 list_add_tail(&buf->stream, &q->stream);
551 if (q->streaming) {
552 spin_lock_irqsave(q->irqlock, flags);
553 q->ops->buf_queue(q, buf);
554 spin_unlock_irqrestore(q->irqlock, flags);
555 }
556 dprintk(1, "qbuf: succeded\n");
557 retval = 0;
558 wake_up_interruptible_sync(&q->wait);
559
560 done:
561 mutex_unlock(&q->vb_lock);
562
563 if (b->memory == V4L2_MEMORY_MMAP)
564 up_read(&current->mm->mmap_sem);
565
566 return retval;
567 }
568
569
570 /* Locking: Caller holds q->vb_lock */
571 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
572 {
573 int retval;
574
575 checks:
576 if (!q->streaming) {
577 dprintk(1, "next_buffer: Not streaming\n");
578 retval = -EINVAL;
579 goto done;
580 }
581
582 if (list_empty(&q->stream)) {
583 if (noblock) {
584 retval = -EAGAIN;
585 dprintk(2, "next_buffer: no buffers to dequeue\n");
586 goto done;
587 } else {
588 dprintk(2, "next_buffer: waiting on buffer\n");
589
590 /* Drop lock to avoid deadlock with qbuf */
591 mutex_unlock(&q->vb_lock);
592
593 /* Checking list_empty and streaming is safe without
594 * locks because we goto checks to validate while
595 * holding locks before proceeding */
596 retval = wait_event_interruptible(q->wait,
597 !list_empty(&q->stream) || !q->streaming);
598 mutex_lock(&q->vb_lock);
599
600 if (retval)
601 goto done;
602
603 goto checks;
604 }
605 }
606
607 retval = 0;
608
609 done:
610 return retval;
611 }
612
613
614 /* Locking: Caller holds q->vb_lock */
615 static int stream_next_buffer(struct videobuf_queue *q,
616 struct videobuf_buffer **vb, int nonblocking)
617 {
618 int retval;
619 struct videobuf_buffer *buf = NULL;
620
621 retval = stream_next_buffer_check_queue(q, nonblocking);
622 if (retval)
623 goto done;
624
625 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
626 retval = videobuf_waiton(buf, nonblocking, 1);
627 if (retval < 0)
628 goto done;
629
630 *vb = buf;
631 done:
632 return retval;
633 }
634
635 int videobuf_dqbuf(struct videobuf_queue *q,
636 struct v4l2_buffer *b, int nonblocking)
637 {
638 struct videobuf_buffer *buf = NULL;
639 int retval;
640
641 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
642
643 mutex_lock(&q->vb_lock);
644
645 retval = stream_next_buffer(q, &buf, nonblocking);
646 if (retval < 0) {
647 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
648 goto done;
649 }
650
651 switch (buf->state) {
652 case VIDEOBUF_ERROR:
653 dprintk(1, "dqbuf: state is error\n");
654 retval = -EIO;
655 CALL(q, sync, q, buf);
656 buf->state = VIDEOBUF_IDLE;
657 break;
658 case VIDEOBUF_DONE:
659 dprintk(1, "dqbuf: state is done\n");
660 CALL(q, sync, q, buf);
661 buf->state = VIDEOBUF_IDLE;
662 break;
663 default:
664 dprintk(1, "dqbuf: state invalid\n");
665 retval = -EINVAL;
666 goto done;
667 }
668 list_del(&buf->stream);
669 memset(b, 0, sizeof(*b));
670 videobuf_status(q, b, buf, q->type);
671
672 done:
673 mutex_unlock(&q->vb_lock);
674 return retval;
675 }
676
677 int videobuf_streamon(struct videobuf_queue *q)
678 {
679 struct videobuf_buffer *buf;
680 unsigned long flags = 0;
681 int retval;
682
683 mutex_lock(&q->vb_lock);
684 retval = -EBUSY;
685 if (q->reading)
686 goto done;
687 retval = 0;
688 if (q->streaming)
689 goto done;
690 q->streaming = 1;
691 spin_lock_irqsave(q->irqlock, flags);
692 list_for_each_entry(buf, &q->stream, stream)
693 if (buf->state == VIDEOBUF_PREPARED)
694 q->ops->buf_queue(q, buf);
695 spin_unlock_irqrestore(q->irqlock, flags);
696
697 wake_up_interruptible_sync(&q->wait);
698 done:
699 mutex_unlock(&q->vb_lock);
700 return retval;
701 }
702
703 /* Locking: Caller holds q->vb_lock */
704 static int __videobuf_streamoff(struct videobuf_queue *q)
705 {
706 if (!q->streaming)
707 return -EINVAL;
708
709 videobuf_queue_cancel(q);
710
711 return 0;
712 }
713
714 int videobuf_streamoff(struct videobuf_queue *q)
715 {
716 int retval;
717
718 mutex_lock(&q->vb_lock);
719 retval = __videobuf_streamoff(q);
720 mutex_unlock(&q->vb_lock);
721
722 return retval;
723 }
724
725 /* Locking: Caller holds q->vb_lock */
726 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
727 char __user *data,
728 size_t count, loff_t *ppos)
729 {
730 enum v4l2_field field;
731 unsigned long flags = 0;
732 int retval;
733
734 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
735
736 /* setup stuff */
737 q->read_buf = videobuf_alloc(q);
738 if (NULL == q->read_buf)
739 return -ENOMEM;
740
741 q->read_buf->memory = V4L2_MEMORY_USERPTR;
742 q->read_buf->baddr = (unsigned long)data;
743 q->read_buf->bsize = count;
744
745 field = videobuf_next_field(q);
746 retval = q->ops->buf_prepare(q, q->read_buf, field);
747 if (0 != retval)
748 goto done;
749
750 /* start capture & wait */
751 spin_lock_irqsave(q->irqlock, flags);
752 q->ops->buf_queue(q, q->read_buf);
753 spin_unlock_irqrestore(q->irqlock, flags);
754 retval = videobuf_waiton(q->read_buf, 0, 0);
755 if (0 == retval) {
756 CALL(q, sync, q, q->read_buf);
757 if (VIDEOBUF_ERROR == q->read_buf->state)
758 retval = -EIO;
759 else
760 retval = q->read_buf->size;
761 }
762
763 done:
764 /* cleanup */
765 q->ops->buf_release(q, q->read_buf);
766 kfree(q->read_buf);
767 q->read_buf = NULL;
768 return retval;
769 }
770
771 ssize_t videobuf_read_one(struct videobuf_queue *q,
772 char __user *data, size_t count, loff_t *ppos,
773 int nonblocking)
774 {
775 enum v4l2_field field;
776 unsigned long flags = 0;
777 unsigned size = 0, nbufs = 1;
778 int retval;
779
780 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
781
782 mutex_lock(&q->vb_lock);
783
784 q->ops->buf_setup(q, &nbufs, &size);
785
786 if (NULL == q->read_buf &&
787 count >= size &&
788 !nonblocking) {
789 retval = videobuf_read_zerocopy(q, data, count, ppos);
790 if (retval >= 0 || retval == -EIO)
791 /* ok, all done */
792 goto done;
793 /* fallback to kernel bounce buffer on failures */
794 }
795
796 if (NULL == q->read_buf) {
797 /* need to capture a new frame */
798 retval = -ENOMEM;
799 q->read_buf = videobuf_alloc(q);
800
801 dprintk(1, "video alloc=0x%p\n", q->read_buf);
802 if (NULL == q->read_buf)
803 goto done;
804 q->read_buf->memory = V4L2_MEMORY_USERPTR;
805 q->read_buf->bsize = count; /* preferred size */
806 field = videobuf_next_field(q);
807 retval = q->ops->buf_prepare(q, q->read_buf, field);
808
809 if (0 != retval) {
810 kfree(q->read_buf);
811 q->read_buf = NULL;
812 goto done;
813 }
814
815 spin_lock_irqsave(q->irqlock, flags);
816 q->ops->buf_queue(q, q->read_buf);
817 spin_unlock_irqrestore(q->irqlock, flags);
818
819 q->read_off = 0;
820 }
821
822 /* wait until capture is done */
823 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
824 if (0 != retval)
825 goto done;
826
827 CALL(q, sync, q, q->read_buf);
828
829 if (VIDEOBUF_ERROR == q->read_buf->state) {
830 /* catch I/O errors */
831 q->ops->buf_release(q, q->read_buf);
832 kfree(q->read_buf);
833 q->read_buf = NULL;
834 retval = -EIO;
835 goto done;
836 }
837
838 /* Copy to userspace */
839 retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
840 if (retval < 0)
841 goto done;
842
843 q->read_off += retval;
844 if (q->read_off == q->read_buf->size) {
845 /* all data copied, cleanup */
846 q->ops->buf_release(q, q->read_buf);
847 kfree(q->read_buf);
848 q->read_buf = NULL;
849 }
850
851 done:
852 mutex_unlock(&q->vb_lock);
853 return retval;
854 }
855
856 /* Locking: Caller holds q->vb_lock */
857 static int __videobuf_read_start(struct videobuf_queue *q)
858 {
859 enum v4l2_field field;
860 unsigned long flags = 0;
861 unsigned int count = 0, size = 0;
862 int err, i;
863
864 q->ops->buf_setup(q, &count, &size);
865 if (count < 2)
866 count = 2;
867 if (count > VIDEO_MAX_FRAME)
868 count = VIDEO_MAX_FRAME;
869 size = PAGE_ALIGN(size);
870
871 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
872 if (err < 0)
873 return err;
874
875 count = err;
876
877 for (i = 0; i < count; i++) {
878 field = videobuf_next_field(q);
879 err = q->ops->buf_prepare(q, q->bufs[i], field);
880 if (err)
881 return err;
882 list_add_tail(&q->bufs[i]->stream, &q->stream);
883 }
884 spin_lock_irqsave(q->irqlock, flags);
885 for (i = 0; i < count; i++)
886 q->ops->buf_queue(q, q->bufs[i]);
887 spin_unlock_irqrestore(q->irqlock, flags);
888 q->reading = 1;
889 return 0;
890 }
891
892 static void __videobuf_read_stop(struct videobuf_queue *q)
893 {
894 int i;
895
896 videobuf_queue_cancel(q);
897 __videobuf_mmap_free(q);
898 INIT_LIST_HEAD(&q->stream);
899 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
900 if (NULL == q->bufs[i])
901 continue;
902 kfree(q->bufs[i]);
903 q->bufs[i] = NULL;
904 }
905 q->read_buf = NULL;
906
907 }
908
909 int videobuf_read_start(struct videobuf_queue *q)
910 {
911 int rc;
912
913 mutex_lock(&q->vb_lock);
914 rc = __videobuf_read_start(q);
915 mutex_unlock(&q->vb_lock);
916
917 return rc;
918 }
919
920 void videobuf_read_stop(struct videobuf_queue *q)
921 {
922 mutex_lock(&q->vb_lock);
923 __videobuf_read_stop(q);
924 mutex_unlock(&q->vb_lock);
925 }
926
927 void videobuf_stop(struct videobuf_queue *q)
928 {
929 mutex_lock(&q->vb_lock);
930
931 if (q->streaming)
932 __videobuf_streamoff(q);
933
934 if (q->reading)
935 __videobuf_read_stop(q);
936
937 mutex_unlock(&q->vb_lock);
938 }
939
940
941 ssize_t videobuf_read_stream(struct videobuf_queue *q,
942 char __user *data, size_t count, loff_t *ppos,
943 int vbihack, int nonblocking)
944 {
945 int rc, retval;
946 unsigned long flags = 0;
947
948 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
949
950 dprintk(2, "%s\n", __func__);
951 mutex_lock(&q->vb_lock);
952 retval = -EBUSY;
953 if (q->streaming)
954 goto done;
955 if (!q->reading) {
956 retval = __videobuf_read_start(q);
957 if (retval < 0)
958 goto done;
959 }
960
961 retval = 0;
962 while (count > 0) {
963 /* get / wait for data */
964 if (NULL == q->read_buf) {
965 q->read_buf = list_entry(q->stream.next,
966 struct videobuf_buffer,
967 stream);
968 list_del(&q->read_buf->stream);
969 q->read_off = 0;
970 }
971 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
972 if (rc < 0) {
973 if (0 == retval)
974 retval = rc;
975 break;
976 }
977
978 if (q->read_buf->state == VIDEOBUF_DONE) {
979 rc = CALL(q, copy_stream, q, data + retval, count,
980 retval, vbihack, nonblocking);
981 if (rc < 0) {
982 retval = rc;
983 break;
984 }
985 retval += rc;
986 count -= rc;
987 q->read_off += rc;
988 } else {
989 /* some error */
990 q->read_off = q->read_buf->size;
991 if (0 == retval)
992 retval = -EIO;
993 }
994
995 /* requeue buffer when done with copying */
996 if (q->read_off == q->read_buf->size) {
997 list_add_tail(&q->read_buf->stream,
998 &q->stream);
999 spin_lock_irqsave(q->irqlock, flags);
1000 q->ops->buf_queue(q, q->read_buf);
1001 spin_unlock_irqrestore(q->irqlock, flags);
1002 q->read_buf = NULL;
1003 }
1004 if (retval < 0)
1005 break;
1006 }
1007
1008 done:
1009 mutex_unlock(&q->vb_lock);
1010 return retval;
1011 }
1012
1013 unsigned int videobuf_poll_stream(struct file *file,
1014 struct videobuf_queue *q,
1015 poll_table *wait)
1016 {
1017 struct videobuf_buffer *buf = NULL;
1018 unsigned int rc = 0;
1019
1020 mutex_lock(&q->vb_lock);
1021 if (q->streaming) {
1022 if (!list_empty(&q->stream))
1023 buf = list_entry(q->stream.next,
1024 struct videobuf_buffer, stream);
1025 } else {
1026 if (!q->reading)
1027 __videobuf_read_start(q);
1028 if (!q->reading) {
1029 rc = POLLERR;
1030 } else if (NULL == q->read_buf) {
1031 q->read_buf = list_entry(q->stream.next,
1032 struct videobuf_buffer,
1033 stream);
1034 list_del(&q->read_buf->stream);
1035 q->read_off = 0;
1036 }
1037 buf = q->read_buf;
1038 }
1039 if (!buf)
1040 rc = POLLERR;
1041
1042 if (0 == rc) {
1043 poll_wait(file, &buf->done, wait);
1044 if (buf->state == VIDEOBUF_DONE ||
1045 buf->state == VIDEOBUF_ERROR)
1046 rc = POLLIN|POLLRDNORM;
1047 }
1048 mutex_unlock(&q->vb_lock);
1049 return rc;
1050 }
1051
1052 int videobuf_mmap_mapper(struct videobuf_queue *q,
1053 struct vm_area_struct *vma)
1054 {
1055 int retval;
1056
1057 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1058
1059 mutex_lock(&q->vb_lock);
1060 retval = CALL(q, mmap_mapper, q, vma);
1061 q->is_mmapped = 1;
1062 mutex_unlock(&q->vb_lock);
1063
1064 return retval;
1065 }
1066
1067 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1068 int videobuf_cgmbuf(struct videobuf_queue *q,
1069 struct video_mbuf *mbuf, int count)
1070 {
1071 struct v4l2_requestbuffers req;
1072 int rc, i;
1073
1074 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1075
1076 memset(&req, 0, sizeof(req));
1077 req.type = q->type;
1078 req.count = count;
1079 req.memory = V4L2_MEMORY_MMAP;
1080 rc = videobuf_reqbufs(q, &req);
1081 if (rc < 0)
1082 return rc;
1083
1084 mbuf->frames = req.count;
1085 mbuf->size = 0;
1086 for (i = 0; i < mbuf->frames; i++) {
1087 mbuf->offsets[i] = q->bufs[i]->boff;
1088 mbuf->size += q->bufs[i]->bsize;
1089 }
1090
1091 return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1094 #endif
1095
1096 /* --------------------------------------------------------------------- */
1097
1098 EXPORT_SYMBOL_GPL(videobuf_waiton);
1099 EXPORT_SYMBOL_GPL(videobuf_iolock);
1100
1101 EXPORT_SYMBOL_GPL(videobuf_alloc);
1102
1103 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1104 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1105 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1106
1107 EXPORT_SYMBOL_GPL(videobuf_next_field);
1108 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1109 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1110 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1111 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1112 EXPORT_SYMBOL_GPL(videobuf_streamon);
1113 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1114
1115 EXPORT_SYMBOL_GPL(videobuf_read_start);
1116 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1117 EXPORT_SYMBOL_GPL(videobuf_stop);
1118 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1119 EXPORT_SYMBOL_GPL(videobuf_read_one);
1120 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1121
1122 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1123 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1124 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
Linux kernel - Deliverables
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