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V4L/DVB: v4l: videobuf: code cleanup
[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/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) \
28 do { \
29 if (unlikely((is) != (should))) { \
30 printk(KERN_ERR \
31 "magic mismatch: %x (expected %x)\n", \
32 is, should); \
33 BUG(); \
34 } \
35 } while (0)
36
37 static int debug;
38 module_param(debug, int, 0644);
39
40 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
41 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
42 MODULE_LICENSE("GPL");
43
44 #define dprintk(level, fmt, arg...) \
45 do { \
46 if (debug >= level) \
47 printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
48 } while (0)
49
50 /* --------------------------------------------------------------------- */
51
52 #define CALL(q, f, arg...) \
53 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
54
55 void *videobuf_alloc(struct videobuf_queue *q)
56 {
57 struct videobuf_buffer *vb;
58
59 BUG_ON(q->msize < sizeof(*vb));
60
61 if (!q->int_ops || !q->int_ops->alloc) {
62 printk(KERN_ERR "No specific ops defined!\n");
63 BUG();
64 }
65
66 vb = q->int_ops->alloc(q->msize);
67 if (NULL != vb) {
68 init_waitqueue_head(&vb->done);
69 vb->magic = MAGIC_BUFFER;
70 }
71
72 return vb;
73 }
74 EXPORT_SYMBOL_GPL(videobuf_alloc);
75
76 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
77 vb->state != VIDEOBUF_QUEUED)
78 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
79 {
80 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
81
82 if (non_blocking) {
83 if (WAITON_CONDITION)
84 return 0;
85 else
86 return -EAGAIN;
87 }
88
89 if (intr)
90 return wait_event_interruptible(vb->done, WAITON_CONDITION);
91 else
92 wait_event(vb->done, WAITON_CONDITION);
93
94 return 0;
95 }
96 EXPORT_SYMBOL_GPL(videobuf_waiton);
97
98 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
99 struct v4l2_framebuffer *fbuf)
100 {
101 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
102 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
103
104 return CALL(q, iolock, q, vb, fbuf);
105 }
106 EXPORT_SYMBOL_GPL(videobuf_iolock);
107
108 void *videobuf_queue_to_vmalloc(struct videobuf_queue *q,
109 struct videobuf_buffer *buf)
110 {
111 if (q->int_ops->vmalloc)
112 return q->int_ops->vmalloc(buf);
113 else
114 return NULL;
115 }
116 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
117
118 /* --------------------------------------------------------------------- */
119
120
121 void videobuf_queue_core_init(struct videobuf_queue *q,
122 const struct videobuf_queue_ops *ops,
123 struct device *dev,
124 spinlock_t *irqlock,
125 enum v4l2_buf_type type,
126 enum v4l2_field field,
127 unsigned int msize,
128 void *priv,
129 struct videobuf_qtype_ops *int_ops)
130 {
131 BUG_ON(!q);
132 memset(q, 0, sizeof(*q));
133 q->irqlock = irqlock;
134 q->dev = dev;
135 q->type = type;
136 q->field = field;
137 q->msize = msize;
138 q->ops = ops;
139 q->priv_data = priv;
140 q->int_ops = int_ops;
141
142 /* All buffer operations are mandatory */
143 BUG_ON(!q->ops->buf_setup);
144 BUG_ON(!q->ops->buf_prepare);
145 BUG_ON(!q->ops->buf_queue);
146 BUG_ON(!q->ops->buf_release);
147
148 /* Lock is mandatory for queue_cancel to work */
149 BUG_ON(!irqlock);
150
151 /* Having implementations for abstract methods are mandatory */
152 BUG_ON(!q->int_ops);
153
154 mutex_init(&q->vb_lock);
155 init_waitqueue_head(&q->wait);
156 INIT_LIST_HEAD(&q->stream);
157 }
158 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
159
160 /* Locking: Only usage in bttv unsafe find way to remove */
161 int videobuf_queue_is_busy(struct videobuf_queue *q)
162 {
163 int i;
164
165 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
166
167 if (q->streaming) {
168 dprintk(1, "busy: streaming active\n");
169 return 1;
170 }
171 if (q->reading) {
172 dprintk(1, "busy: pending read #1\n");
173 return 1;
174 }
175 if (q->read_buf) {
176 dprintk(1, "busy: pending read #2\n");
177 return 1;
178 }
179 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
180 if (NULL == q->bufs[i])
181 continue;
182 if (q->bufs[i]->map) {
183 dprintk(1, "busy: buffer #%d mapped\n", i);
184 return 1;
185 }
186 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
187 dprintk(1, "busy: buffer #%d queued\n", i);
188 return 1;
189 }
190 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
191 dprintk(1, "busy: buffer #%d avtive\n", i);
192 return 1;
193 }
194 }
195 return 0;
196 }
197 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
198
199 /* Locking: Caller holds q->vb_lock */
200 void videobuf_queue_cancel(struct videobuf_queue *q)
201 {
202 unsigned long flags = 0;
203 int i;
204
205 q->streaming = 0;
206 q->reading = 0;
207 wake_up_interruptible_sync(&q->wait);
208
209 /* remove queued buffers from list */
210 spin_lock_irqsave(q->irqlock, flags);
211 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
212 if (NULL == q->bufs[i])
213 continue;
214 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
215 list_del(&q->bufs[i]->queue);
216 q->bufs[i]->state = VIDEOBUF_ERROR;
217 wake_up_all(&q->bufs[i]->done);
218 }
219 }
220 spin_unlock_irqrestore(q->irqlock, flags);
221
222 /* free all buffers + clear queue */
223 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
224 if (NULL == q->bufs[i])
225 continue;
226 q->ops->buf_release(q, q->bufs[i]);
227 }
228 INIT_LIST_HEAD(&q->stream);
229 }
230 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
231
232 /* --------------------------------------------------------------------- */
233
234 /* Locking: Caller holds q->vb_lock */
235 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
236 {
237 enum v4l2_field field = q->field;
238
239 BUG_ON(V4L2_FIELD_ANY == field);
240
241 if (V4L2_FIELD_ALTERNATE == field) {
242 if (V4L2_FIELD_TOP == q->last) {
243 field = V4L2_FIELD_BOTTOM;
244 q->last = V4L2_FIELD_BOTTOM;
245 } else {
246 field = V4L2_FIELD_TOP;
247 q->last = V4L2_FIELD_TOP;
248 }
249 }
250 return field;
251 }
252 EXPORT_SYMBOL_GPL(videobuf_next_field);
253
254 /* Locking: Caller holds q->vb_lock */
255 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
256 struct videobuf_buffer *vb, enum v4l2_buf_type type)
257 {
258 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
259 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
260
261 b->index = vb->i;
262 b->type = type;
263
264 b->memory = vb->memory;
265 switch (b->memory) {
266 case V4L2_MEMORY_MMAP:
267 b->m.offset = vb->boff;
268 b->length = vb->bsize;
269 break;
270 case V4L2_MEMORY_USERPTR:
271 b->m.userptr = vb->baddr;
272 b->length = vb->bsize;
273 break;
274 case V4L2_MEMORY_OVERLAY:
275 b->m.offset = vb->boff;
276 break;
277 }
278
279 b->flags = 0;
280 if (vb->map)
281 b->flags |= V4L2_BUF_FLAG_MAPPED;
282
283 switch (vb->state) {
284 case VIDEOBUF_PREPARED:
285 case VIDEOBUF_QUEUED:
286 case VIDEOBUF_ACTIVE:
287 b->flags |= V4L2_BUF_FLAG_QUEUED;
288 break;
289 case VIDEOBUF_DONE:
290 case VIDEOBUF_ERROR:
291 b->flags |= V4L2_BUF_FLAG_DONE;
292 break;
293 case VIDEOBUF_NEEDS_INIT:
294 case VIDEOBUF_IDLE:
295 /* nothing */
296 break;
297 }
298
299 if (vb->input != UNSET) {
300 b->flags |= V4L2_BUF_FLAG_INPUT;
301 b->input = vb->input;
302 }
303
304 b->field = vb->field;
305 b->timestamp = vb->ts;
306 b->bytesused = vb->size;
307 b->sequence = vb->field_count >> 1;
308 }
309
310 /* Locking: Caller holds q->vb_lock */
311 static int __videobuf_mmap_free(struct videobuf_queue *q)
312 {
313 int i;
314 int rc;
315
316 if (!q)
317 return 0;
318
319 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
320
321 rc = CALL(q, mmap_free, q);
322
323 q->is_mmapped = 0;
324
325 if (rc < 0)
326 return rc;
327
328 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
329 if (NULL == q->bufs[i])
330 continue;
331 q->ops->buf_release(q, q->bufs[i]);
332 kfree(q->bufs[i]);
333 q->bufs[i] = NULL;
334 }
335
336 return rc;
337 }
338
339 int videobuf_mmap_free(struct videobuf_queue *q)
340 {
341 int ret;
342 mutex_lock(&q->vb_lock);
343 ret = __videobuf_mmap_free(q);
344 mutex_unlock(&q->vb_lock);
345 return ret;
346 }
347 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
348
349 /* Locking: Caller holds q->vb_lock */
350 int __videobuf_mmap_setup(struct videobuf_queue *q,
351 unsigned int bcount, unsigned int bsize,
352 enum v4l2_memory memory)
353 {
354 unsigned int i;
355 int err;
356
357 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
358
359 err = __videobuf_mmap_free(q);
360 if (0 != err)
361 return err;
362
363 /* Allocate and initialize buffers */
364 for (i = 0; i < bcount; i++) {
365 q->bufs[i] = videobuf_alloc(q);
366
367 if (NULL == q->bufs[i])
368 break;
369
370 q->bufs[i]->i = i;
371 q->bufs[i]->input = UNSET;
372 q->bufs[i]->memory = memory;
373 q->bufs[i]->bsize = bsize;
374 switch (memory) {
375 case V4L2_MEMORY_MMAP:
376 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
377 break;
378 case V4L2_MEMORY_USERPTR:
379 case V4L2_MEMORY_OVERLAY:
380 /* nothing */
381 break;
382 }
383 }
384
385 if (!i)
386 return -ENOMEM;
387
388 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
389
390 return i;
391 }
392 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
393
394 int videobuf_mmap_setup(struct videobuf_queue *q,
395 unsigned int bcount, unsigned int bsize,
396 enum v4l2_memory memory)
397 {
398 int ret;
399 mutex_lock(&q->vb_lock);
400 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
401 mutex_unlock(&q->vb_lock);
402 return ret;
403 }
404 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
405
406 int videobuf_reqbufs(struct videobuf_queue *q,
407 struct v4l2_requestbuffers *req)
408 {
409 unsigned int size, count;
410 int retval;
411
412 if (req->count < 1) {
413 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
414 return -EINVAL;
415 }
416
417 if (req->memory != V4L2_MEMORY_MMAP &&
418 req->memory != V4L2_MEMORY_USERPTR &&
419 req->memory != V4L2_MEMORY_OVERLAY) {
420 dprintk(1, "reqbufs: memory type invalid\n");
421 return -EINVAL;
422 }
423
424 mutex_lock(&q->vb_lock);
425 if (req->type != q->type) {
426 dprintk(1, "reqbufs: queue type invalid\n");
427 retval = -EINVAL;
428 goto done;
429 }
430
431 if (q->streaming) {
432 dprintk(1, "reqbufs: streaming already exists\n");
433 retval = -EBUSY;
434 goto done;
435 }
436 if (!list_empty(&q->stream)) {
437 dprintk(1, "reqbufs: stream running\n");
438 retval = -EBUSY;
439 goto done;
440 }
441
442 count = req->count;
443 if (count > VIDEO_MAX_FRAME)
444 count = VIDEO_MAX_FRAME;
445 size = 0;
446 q->ops->buf_setup(q, &count, &size);
447 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
448 count, size,
449 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
450
451 retval = __videobuf_mmap_setup(q, count, size, req->memory);
452 if (retval < 0) {
453 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
454 goto done;
455 }
456
457 req->count = retval;
458 retval = 0;
459
460 done:
461 mutex_unlock(&q->vb_lock);
462 return retval;
463 }
464 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
465
466 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
467 {
468 int ret = -EINVAL;
469
470 mutex_lock(&q->vb_lock);
471 if (unlikely(b->type != q->type)) {
472 dprintk(1, "querybuf: Wrong type.\n");
473 goto done;
474 }
475 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
476 dprintk(1, "querybuf: index out of range.\n");
477 goto done;
478 }
479 if (unlikely(NULL == q->bufs[b->index])) {
480 dprintk(1, "querybuf: buffer is null.\n");
481 goto done;
482 }
483
484 videobuf_status(q, b, q->bufs[b->index], q->type);
485
486 ret = 0;
487 done:
488 mutex_unlock(&q->vb_lock);
489 return ret;
490 }
491 EXPORT_SYMBOL_GPL(videobuf_querybuf);
492
493 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
494 {
495 struct videobuf_buffer *buf;
496 enum v4l2_field field;
497 unsigned long flags = 0;
498 int retval;
499
500 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
501
502 if (b->memory == V4L2_MEMORY_MMAP)
503 down_read(&current->mm->mmap_sem);
504
505 mutex_lock(&q->vb_lock);
506 retval = -EBUSY;
507 if (q->reading) {
508 dprintk(1, "qbuf: Reading running...\n");
509 goto done;
510 }
511 retval = -EINVAL;
512 if (b->type != q->type) {
513 dprintk(1, "qbuf: Wrong type.\n");
514 goto done;
515 }
516 if (b->index >= VIDEO_MAX_FRAME) {
517 dprintk(1, "qbuf: index out of range.\n");
518 goto done;
519 }
520 buf = q->bufs[b->index];
521 if (NULL == buf) {
522 dprintk(1, "qbuf: buffer is null.\n");
523 goto done;
524 }
525 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
526 if (buf->memory != b->memory) {
527 dprintk(1, "qbuf: memory type is wrong.\n");
528 goto done;
529 }
530 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
531 dprintk(1, "qbuf: buffer is already queued or active.\n");
532 goto done;
533 }
534
535 if (b->flags & V4L2_BUF_FLAG_INPUT) {
536 if (b->input >= q->inputs) {
537 dprintk(1, "qbuf: wrong input.\n");
538 goto done;
539 }
540 buf->input = b->input;
541 } else {
542 buf->input = UNSET;
543 }
544
545 switch (b->memory) {
546 case V4L2_MEMORY_MMAP:
547 if (0 == buf->baddr) {
548 dprintk(1, "qbuf: mmap requested "
549 "but buffer addr is zero!\n");
550 goto done;
551 }
552 break;
553 case V4L2_MEMORY_USERPTR:
554 if (b->length < buf->bsize) {
555 dprintk(1, "qbuf: buffer length is not enough\n");
556 goto done;
557 }
558 if (VIDEOBUF_NEEDS_INIT != buf->state &&
559 buf->baddr != b->m.userptr)
560 q->ops->buf_release(q, buf);
561 buf->baddr = b->m.userptr;
562 break;
563 case V4L2_MEMORY_OVERLAY:
564 buf->boff = b->m.offset;
565 break;
566 default:
567 dprintk(1, "qbuf: wrong memory type\n");
568 goto done;
569 }
570
571 dprintk(1, "qbuf: requesting next field\n");
572 field = videobuf_next_field(q);
573 retval = q->ops->buf_prepare(q, buf, field);
574 if (0 != retval) {
575 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
576 goto done;
577 }
578
579 list_add_tail(&buf->stream, &q->stream);
580 if (q->streaming) {
581 spin_lock_irqsave(q->irqlock, flags);
582 q->ops->buf_queue(q, buf);
583 spin_unlock_irqrestore(q->irqlock, flags);
584 }
585 dprintk(1, "qbuf: succeeded\n");
586 retval = 0;
587 wake_up_interruptible_sync(&q->wait);
588
589 done:
590 mutex_unlock(&q->vb_lock);
591
592 if (b->memory == V4L2_MEMORY_MMAP)
593 up_read(&current->mm->mmap_sem);
594
595 return retval;
596 }
597 EXPORT_SYMBOL_GPL(videobuf_qbuf);
598
599 /* Locking: Caller holds q->vb_lock */
600 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
601 {
602 int retval;
603
604 checks:
605 if (!q->streaming) {
606 dprintk(1, "next_buffer: Not streaming\n");
607 retval = -EINVAL;
608 goto done;
609 }
610
611 if (list_empty(&q->stream)) {
612 if (noblock) {
613 retval = -EAGAIN;
614 dprintk(2, "next_buffer: no buffers to dequeue\n");
615 goto done;
616 } else {
617 dprintk(2, "next_buffer: waiting on buffer\n");
618
619 /* Drop lock to avoid deadlock with qbuf */
620 mutex_unlock(&q->vb_lock);
621
622 /* Checking list_empty and streaming is safe without
623 * locks because we goto checks to validate while
624 * holding locks before proceeding */
625 retval = wait_event_interruptible(q->wait,
626 !list_empty(&q->stream) || !q->streaming);
627 mutex_lock(&q->vb_lock);
628
629 if (retval)
630 goto done;
631
632 goto checks;
633 }
634 }
635
636 retval = 0;
637
638 done:
639 return retval;
640 }
641
642 /* Locking: Caller holds q->vb_lock */
643 static int stream_next_buffer(struct videobuf_queue *q,
644 struct videobuf_buffer **vb, int nonblocking)
645 {
646 int retval;
647 struct videobuf_buffer *buf = NULL;
648
649 retval = stream_next_buffer_check_queue(q, nonblocking);
650 if (retval)
651 goto done;
652
653 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
654 retval = videobuf_waiton(buf, nonblocking, 1);
655 if (retval < 0)
656 goto done;
657
658 *vb = buf;
659 done:
660 return retval;
661 }
662
663 int videobuf_dqbuf(struct videobuf_queue *q,
664 struct v4l2_buffer *b, int nonblocking)
665 {
666 struct videobuf_buffer *buf = NULL;
667 int retval;
668
669 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
670
671 mutex_lock(&q->vb_lock);
672
673 retval = stream_next_buffer(q, &buf, nonblocking);
674 if (retval < 0) {
675 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
676 goto done;
677 }
678
679 switch (buf->state) {
680 case VIDEOBUF_ERROR:
681 dprintk(1, "dqbuf: state is error\n");
682 retval = -EIO;
683 CALL(q, sync, q, buf);
684 buf->state = VIDEOBUF_IDLE;
685 break;
686 case VIDEOBUF_DONE:
687 dprintk(1, "dqbuf: state is done\n");
688 CALL(q, sync, q, buf);
689 buf->state = VIDEOBUF_IDLE;
690 break;
691 default:
692 dprintk(1, "dqbuf: state invalid\n");
693 retval = -EINVAL;
694 goto done;
695 }
696 list_del(&buf->stream);
697 memset(b, 0, sizeof(*b));
698 videobuf_status(q, b, buf, q->type);
699 done:
700 mutex_unlock(&q->vb_lock);
701 return retval;
702 }
703 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
704
705 int videobuf_streamon(struct videobuf_queue *q)
706 {
707 struct videobuf_buffer *buf;
708 unsigned long flags = 0;
709 int retval;
710
711 mutex_lock(&q->vb_lock);
712 retval = -EBUSY;
713 if (q->reading)
714 goto done;
715 retval = 0;
716 if (q->streaming)
717 goto done;
718 q->streaming = 1;
719 spin_lock_irqsave(q->irqlock, flags);
720 list_for_each_entry(buf, &q->stream, stream)
721 if (buf->state == VIDEOBUF_PREPARED)
722 q->ops->buf_queue(q, buf);
723 spin_unlock_irqrestore(q->irqlock, flags);
724
725 wake_up_interruptible_sync(&q->wait);
726 done:
727 mutex_unlock(&q->vb_lock);
728 return retval;
729 }
730 EXPORT_SYMBOL_GPL(videobuf_streamon);
731
732 /* Locking: Caller holds q->vb_lock */
733 static int __videobuf_streamoff(struct videobuf_queue *q)
734 {
735 if (!q->streaming)
736 return -EINVAL;
737
738 videobuf_queue_cancel(q);
739
740 return 0;
741 }
742
743 int videobuf_streamoff(struct videobuf_queue *q)
744 {
745 int retval;
746
747 mutex_lock(&q->vb_lock);
748 retval = __videobuf_streamoff(q);
749 mutex_unlock(&q->vb_lock);
750
751 return retval;
752 }
753 EXPORT_SYMBOL_GPL(videobuf_streamoff);
754
755 /* Locking: Caller holds q->vb_lock */
756 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
757 char __user *data,
758 size_t count, loff_t *ppos)
759 {
760 enum v4l2_field field;
761 unsigned long flags = 0;
762 int retval;
763
764 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
765
766 /* setup stuff */
767 q->read_buf = videobuf_alloc(q);
768 if (NULL == q->read_buf)
769 return -ENOMEM;
770
771 q->read_buf->memory = V4L2_MEMORY_USERPTR;
772 q->read_buf->baddr = (unsigned long)data;
773 q->read_buf->bsize = count;
774
775 field = videobuf_next_field(q);
776 retval = q->ops->buf_prepare(q, q->read_buf, field);
777 if (0 != retval)
778 goto done;
779
780 /* start capture & wait */
781 spin_lock_irqsave(q->irqlock, flags);
782 q->ops->buf_queue(q, q->read_buf);
783 spin_unlock_irqrestore(q->irqlock, flags);
784 retval = videobuf_waiton(q->read_buf, 0, 0);
785 if (0 == retval) {
786 CALL(q, sync, q, q->read_buf);
787 if (VIDEOBUF_ERROR == q->read_buf->state)
788 retval = -EIO;
789 else
790 retval = q->read_buf->size;
791 }
792
793 done:
794 /* cleanup */
795 q->ops->buf_release(q, q->read_buf);
796 kfree(q->read_buf);
797 q->read_buf = NULL;
798 return retval;
799 }
800
801 ssize_t videobuf_read_one(struct videobuf_queue *q,
802 char __user *data, size_t count, loff_t *ppos,
803 int nonblocking)
804 {
805 enum v4l2_field field;
806 unsigned long flags = 0;
807 unsigned size = 0, nbufs = 1;
808 int retval;
809
810 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
811
812 mutex_lock(&q->vb_lock);
813
814 q->ops->buf_setup(q, &nbufs, &size);
815
816 if (NULL == q->read_buf &&
817 count >= size &&
818 !nonblocking) {
819 retval = videobuf_read_zerocopy(q, data, count, ppos);
820 if (retval >= 0 || retval == -EIO)
821 /* ok, all done */
822 goto done;
823 /* fallback to kernel bounce buffer on failures */
824 }
825
826 if (NULL == q->read_buf) {
827 /* need to capture a new frame */
828 retval = -ENOMEM;
829 q->read_buf = videobuf_alloc(q);
830
831 dprintk(1, "video alloc=0x%p\n", q->read_buf);
832 if (NULL == q->read_buf)
833 goto done;
834 q->read_buf->memory = V4L2_MEMORY_USERPTR;
835 q->read_buf->bsize = count; /* preferred size */
836 field = videobuf_next_field(q);
837 retval = q->ops->buf_prepare(q, q->read_buf, field);
838
839 if (0 != retval) {
840 kfree(q->read_buf);
841 q->read_buf = NULL;
842 goto done;
843 }
844
845 spin_lock_irqsave(q->irqlock, flags);
846 q->ops->buf_queue(q, q->read_buf);
847 spin_unlock_irqrestore(q->irqlock, flags);
848
849 q->read_off = 0;
850 }
851
852 /* wait until capture is done */
853 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
854 if (0 != retval)
855 goto done;
856
857 CALL(q, sync, q, q->read_buf);
858
859 if (VIDEOBUF_ERROR == q->read_buf->state) {
860 /* catch I/O errors */
861 q->ops->buf_release(q, q->read_buf);
862 kfree(q->read_buf);
863 q->read_buf = NULL;
864 retval = -EIO;
865 goto done;
866 }
867
868 /* Copy to userspace */
869 retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
870 if (retval < 0)
871 goto done;
872
873 q->read_off += retval;
874 if (q->read_off == q->read_buf->size) {
875 /* all data copied, cleanup */
876 q->ops->buf_release(q, q->read_buf);
877 kfree(q->read_buf);
878 q->read_buf = NULL;
879 }
880
881 done:
882 mutex_unlock(&q->vb_lock);
883 return retval;
884 }
885 EXPORT_SYMBOL_GPL(videobuf_read_one);
886
887 /* Locking: Caller holds q->vb_lock */
888 static int __videobuf_read_start(struct videobuf_queue *q)
889 {
890 enum v4l2_field field;
891 unsigned long flags = 0;
892 unsigned int count = 0, size = 0;
893 int err, i;
894
895 q->ops->buf_setup(q, &count, &size);
896 if (count < 2)
897 count = 2;
898 if (count > VIDEO_MAX_FRAME)
899 count = VIDEO_MAX_FRAME;
900 size = PAGE_ALIGN(size);
901
902 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
903 if (err < 0)
904 return err;
905
906 count = err;
907
908 for (i = 0; i < count; i++) {
909 field = videobuf_next_field(q);
910 err = q->ops->buf_prepare(q, q->bufs[i], field);
911 if (err)
912 return err;
913 list_add_tail(&q->bufs[i]->stream, &q->stream);
914 }
915 spin_lock_irqsave(q->irqlock, flags);
916 for (i = 0; i < count; i++)
917 q->ops->buf_queue(q, q->bufs[i]);
918 spin_unlock_irqrestore(q->irqlock, flags);
919 q->reading = 1;
920 return 0;
921 }
922
923 static void __videobuf_read_stop(struct videobuf_queue *q)
924 {
925 int i;
926
927 videobuf_queue_cancel(q);
928 __videobuf_mmap_free(q);
929 INIT_LIST_HEAD(&q->stream);
930 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
931 if (NULL == q->bufs[i])
932 continue;
933 kfree(q->bufs[i]);
934 q->bufs[i] = NULL;
935 }
936 q->read_buf = NULL;
937 }
938
939 int videobuf_read_start(struct videobuf_queue *q)
940 {
941 int rc;
942
943 mutex_lock(&q->vb_lock);
944 rc = __videobuf_read_start(q);
945 mutex_unlock(&q->vb_lock);
946
947 return rc;
948 }
949 EXPORT_SYMBOL_GPL(videobuf_read_start);
950
951 void videobuf_read_stop(struct videobuf_queue *q)
952 {
953 mutex_lock(&q->vb_lock);
954 __videobuf_read_stop(q);
955 mutex_unlock(&q->vb_lock);
956 }
957 EXPORT_SYMBOL_GPL(videobuf_read_stop);
958
959 void videobuf_stop(struct videobuf_queue *q)
960 {
961 mutex_lock(&q->vb_lock);
962
963 if (q->streaming)
964 __videobuf_streamoff(q);
965
966 if (q->reading)
967 __videobuf_read_stop(q);
968
969 mutex_unlock(&q->vb_lock);
970 }
971 EXPORT_SYMBOL_GPL(videobuf_stop);
972
973 ssize_t videobuf_read_stream(struct videobuf_queue *q,
974 char __user *data, size_t count, loff_t *ppos,
975 int vbihack, int nonblocking)
976 {
977 int rc, retval;
978 unsigned long flags = 0;
979
980 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
981
982 dprintk(2, "%s\n", __func__);
983 mutex_lock(&q->vb_lock);
984 retval = -EBUSY;
985 if (q->streaming)
986 goto done;
987 if (!q->reading) {
988 retval = __videobuf_read_start(q);
989 if (retval < 0)
990 goto done;
991 }
992
993 retval = 0;
994 while (count > 0) {
995 /* get / wait for data */
996 if (NULL == q->read_buf) {
997 q->read_buf = list_entry(q->stream.next,
998 struct videobuf_buffer,
999 stream);
1000 list_del(&q->read_buf->stream);
1001 q->read_off = 0;
1002 }
1003 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
1004 if (rc < 0) {
1005 if (0 == retval)
1006 retval = rc;
1007 break;
1008 }
1009
1010 if (q->read_buf->state == VIDEOBUF_DONE) {
1011 rc = CALL(q, copy_stream, q, data + retval, count,
1012 retval, vbihack, nonblocking);
1013 if (rc < 0) {
1014 retval = rc;
1015 break;
1016 }
1017 retval += rc;
1018 count -= rc;
1019 q->read_off += rc;
1020 } else {
1021 /* some error */
1022 q->read_off = q->read_buf->size;
1023 if (0 == retval)
1024 retval = -EIO;
1025 }
1026
1027 /* requeue buffer when done with copying */
1028 if (q->read_off == q->read_buf->size) {
1029 list_add_tail(&q->read_buf->stream,
1030 &q->stream);
1031 spin_lock_irqsave(q->irqlock, flags);
1032 q->ops->buf_queue(q, q->read_buf);
1033 spin_unlock_irqrestore(q->irqlock, flags);
1034 q->read_buf = NULL;
1035 }
1036 if (retval < 0)
1037 break;
1038 }
1039
1040 done:
1041 mutex_unlock(&q->vb_lock);
1042 return retval;
1043 }
1044 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1045
1046 unsigned int videobuf_poll_stream(struct file *file,
1047 struct videobuf_queue *q,
1048 poll_table *wait)
1049 {
1050 struct videobuf_buffer *buf = NULL;
1051 unsigned int rc = 0;
1052
1053 mutex_lock(&q->vb_lock);
1054 if (q->streaming) {
1055 if (!list_empty(&q->stream))
1056 buf = list_entry(q->stream.next,
1057 struct videobuf_buffer, stream);
1058 } else {
1059 if (!q->reading)
1060 __videobuf_read_start(q);
1061 if (!q->reading) {
1062 rc = POLLERR;
1063 } else if (NULL == q->read_buf) {
1064 q->read_buf = list_entry(q->stream.next,
1065 struct videobuf_buffer,
1066 stream);
1067 list_del(&q->read_buf->stream);
1068 q->read_off = 0;
1069 }
1070 buf = q->read_buf;
1071 }
1072 if (!buf)
1073 rc = POLLERR;
1074
1075 if (0 == rc) {
1076 poll_wait(file, &buf->done, wait);
1077 if (buf->state == VIDEOBUF_DONE ||
1078 buf->state == VIDEOBUF_ERROR)
1079 rc = POLLIN|POLLRDNORM;
1080 }
1081 mutex_unlock(&q->vb_lock);
1082 return rc;
1083 }
1084 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1085
1086 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1087 {
1088 int retval;
1089
1090 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1091
1092 mutex_lock(&q->vb_lock);
1093 retval = CALL(q, mmap_mapper, q, vma);
1094 q->is_mmapped = 1;
1095 mutex_unlock(&q->vb_lock);
1096
1097 return retval;
1098 }
1099 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1100
1101 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1102 int videobuf_cgmbuf(struct videobuf_queue *q,
1103 struct video_mbuf *mbuf, int count)
1104 {
1105 struct v4l2_requestbuffers req;
1106 int rc, i;
1107
1108 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1109
1110 memset(&req, 0, sizeof(req));
1111 req.type = q->type;
1112 req.count = count;
1113 req.memory = V4L2_MEMORY_MMAP;
1114 rc = videobuf_reqbufs(q, &req);
1115 if (rc < 0)
1116 return rc;
1117
1118 mbuf->frames = req.count;
1119 mbuf->size = 0;
1120 for (i = 0; i < mbuf->frames; i++) {
1121 mbuf->offsets[i] = q->bufs[i]->boff;
1122 mbuf->size += PAGE_ALIGN(q->bufs[i]->bsize);
1123 }
1124
1125 return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1128 #endif
1129
Linux kernel - Deliverables
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