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pvclock: introduce seqcount-like API
[linux/fpc-iii.git] / drivers / media / v4l2-core / videobuf-core.c
blobdef84753c4c32a41230237aa686a89ccd03143f7
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 #define CALLPTR(q, f, arg...) \
55 ((q->int_ops->f) ? q->int_ops->f(arg) : NULL)
56
57 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
58 {
59 struct videobuf_buffer *vb;
60
61 BUG_ON(q->msize < sizeof(*vb));
62
63 if (!q->int_ops || !q->int_ops->alloc_vb) {
64 printk(KERN_ERR "No specific ops defined!\n");
65 BUG();
66 }
67
68 vb = q->int_ops->alloc_vb(q->msize);
69 if (NULL != vb) {
70 init_waitqueue_head(&vb->done);
71 vb->magic = MAGIC_BUFFER;
72 }
73
74 return vb;
75 }
76 EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
77
78 static int state_neither_active_nor_queued(struct videobuf_queue *q,
79 struct videobuf_buffer *vb)
80 {
81 unsigned long flags;
82 bool rc;
83
84 spin_lock_irqsave(q->irqlock, flags);
85 rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
86 spin_unlock_irqrestore(q->irqlock, flags);
87 return rc;
88 };
89
90 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
91 int non_blocking, int intr)
92 {
93 bool is_ext_locked;
94 int ret = 0;
95
96 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
97
98 if (non_blocking) {
99 if (state_neither_active_nor_queued(q, vb))
100 return 0;
101 return -EAGAIN;
102 }
103
104 is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
105
106 /* Release vdev lock to prevent this wait from blocking outside access to
107 the device. */
108 if (is_ext_locked)
109 mutex_unlock(q->ext_lock);
110 if (intr)
111 ret = wait_event_interruptible(vb->done,
112 state_neither_active_nor_queued(q, vb));
113 else
114 wait_event(vb->done, state_neither_active_nor_queued(q, vb));
115 /* Relock */
116 if (is_ext_locked)
117 mutex_lock(q->ext_lock);
118
119 return ret;
120 }
121 EXPORT_SYMBOL_GPL(videobuf_waiton);
122
123 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
124 struct v4l2_framebuffer *fbuf)
125 {
126 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
127 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
128
129 return CALL(q, iolock, q, vb, fbuf);
130 }
131 EXPORT_SYMBOL_GPL(videobuf_iolock);
132
133 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
134 struct videobuf_buffer *buf)
135 {
136 if (q->int_ops->vaddr)
137 return q->int_ops->vaddr(buf);
138 return NULL;
139 }
140 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
141
142 /* --------------------------------------------------------------------- */
143
144
145 void videobuf_queue_core_init(struct videobuf_queue *q,
146 const struct videobuf_queue_ops *ops,
147 struct device *dev,
148 spinlock_t *irqlock,
149 enum v4l2_buf_type type,
150 enum v4l2_field field,
151 unsigned int msize,
152 void *priv,
153 struct videobuf_qtype_ops *int_ops,
154 struct mutex *ext_lock)
155 {
156 BUG_ON(!q);
157 memset(q, 0, sizeof(*q));
158 q->irqlock = irqlock;
159 q->ext_lock = ext_lock;
160 q->dev = dev;
161 q->type = type;
162 q->field = field;
163 q->msize = msize;
164 q->ops = ops;
165 q->priv_data = priv;
166 q->int_ops = int_ops;
167
168 /* All buffer operations are mandatory */
169 BUG_ON(!q->ops->buf_setup);
170 BUG_ON(!q->ops->buf_prepare);
171 BUG_ON(!q->ops->buf_queue);
172 BUG_ON(!q->ops->buf_release);
173
174 /* Lock is mandatory for queue_cancel to work */
175 BUG_ON(!irqlock);
176
177 /* Having implementations for abstract methods are mandatory */
178 BUG_ON(!q->int_ops);
179
180 mutex_init(&q->vb_lock);
181 init_waitqueue_head(&q->wait);
182 INIT_LIST_HEAD(&q->stream);
183 }
184 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
185
186 /* Locking: Only usage in bttv unsafe find way to remove */
187 int videobuf_queue_is_busy(struct videobuf_queue *q)
188 {
189 int i;
190
191 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
192
193 if (q->streaming) {
194 dprintk(1, "busy: streaming active\n");
195 return 1;
196 }
197 if (q->reading) {
198 dprintk(1, "busy: pending read #1\n");
199 return 1;
200 }
201 if (q->read_buf) {
202 dprintk(1, "busy: pending read #2\n");
203 return 1;
204 }
205 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
206 if (NULL == q->bufs[i])
207 continue;
208 if (q->bufs[i]->map) {
209 dprintk(1, "busy: buffer #%d mapped\n", i);
210 return 1;
211 }
212 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
213 dprintk(1, "busy: buffer #%d queued\n", i);
214 return 1;
215 }
216 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
217 dprintk(1, "busy: buffer #%d avtive\n", i);
218 return 1;
219 }
220 }
221 return 0;
222 }
223 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
224
225 /**
226 * __videobuf_free() - free all the buffers and their control structures
227 *
228 * This function can only be called if streaming/reading is off, i.e. no buffers
229 * are under control of the driver.
230 */
231 /* Locking: Caller holds q->vb_lock */
232 static int __videobuf_free(struct videobuf_queue *q)
233 {
234 int i;
235
236 dprintk(1, "%s\n", __func__);
237 if (!q)
238 return 0;
239
240 if (q->streaming || q->reading) {
241 dprintk(1, "Cannot free buffers when streaming or reading\n");
242 return -EBUSY;
243 }
244
245 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
246
247 for (i = 0; i < VIDEO_MAX_FRAME; i++)
248 if (q->bufs[i] && q->bufs[i]->map) {
249 dprintk(1, "Cannot free mmapped buffers\n");
250 return -EBUSY;
251 }
252
253 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
254 if (NULL == q->bufs[i])
255 continue;
256 q->ops->buf_release(q, q->bufs[i]);
257 kfree(q->bufs[i]);
258 q->bufs[i] = NULL;
259 }
260
261 return 0;
262 }
263
264 /* Locking: Caller holds q->vb_lock */
265 void videobuf_queue_cancel(struct videobuf_queue *q)
266 {
267 unsigned long flags = 0;
268 int i;
269
270 q->streaming = 0;
271 q->reading = 0;
272 wake_up_interruptible_sync(&q->wait);
273
274 /* remove queued buffers from list */
275 spin_lock_irqsave(q->irqlock, flags);
276 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
277 if (NULL == q->bufs[i])
278 continue;
279 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
280 list_del(&q->bufs[i]->queue);
281 q->bufs[i]->state = VIDEOBUF_ERROR;
282 wake_up_all(&q->bufs[i]->done);
283 }
284 }
285 spin_unlock_irqrestore(q->irqlock, flags);
286
287 /* free all buffers + clear queue */
288 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
289 if (NULL == q->bufs[i])
290 continue;
291 q->ops->buf_release(q, q->bufs[i]);
292 }
293 INIT_LIST_HEAD(&q->stream);
294 }
295 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
296
297 /* --------------------------------------------------------------------- */
298
299 /* Locking: Caller holds q->vb_lock */
300 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
301 {
302 enum v4l2_field field = q->field;
303
304 BUG_ON(V4L2_FIELD_ANY == field);
305
306 if (V4L2_FIELD_ALTERNATE == field) {
307 if (V4L2_FIELD_TOP == q->last) {
308 field = V4L2_FIELD_BOTTOM;
309 q->last = V4L2_FIELD_BOTTOM;
310 } else {
311 field = V4L2_FIELD_TOP;
312 q->last = V4L2_FIELD_TOP;
313 }
314 }
315 return field;
316 }
317 EXPORT_SYMBOL_GPL(videobuf_next_field);
318
319 /* Locking: Caller holds q->vb_lock */
320 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
321 struct videobuf_buffer *vb, enum v4l2_buf_type type)
322 {
323 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
324 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
325
326 b->index = vb->i;
327 b->type = type;
328
329 b->memory = vb->memory;
330 switch (b->memory) {
331 case V4L2_MEMORY_MMAP:
332 b->m.offset = vb->boff;
333 b->length = vb->bsize;
334 break;
335 case V4L2_MEMORY_USERPTR:
336 b->m.userptr = vb->baddr;
337 b->length = vb->bsize;
338 break;
339 case V4L2_MEMORY_OVERLAY:
340 b->m.offset = vb->boff;
341 break;
342 case V4L2_MEMORY_DMABUF:
343 /* DMABUF is not handled in videobuf framework */
344 break;
345 }
346
347 b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
348 if (vb->map)
349 b->flags |= V4L2_BUF_FLAG_MAPPED;
350
351 switch (vb->state) {
352 case VIDEOBUF_PREPARED:
353 case VIDEOBUF_QUEUED:
354 case VIDEOBUF_ACTIVE:
355 b->flags |= V4L2_BUF_FLAG_QUEUED;
356 break;
357 case VIDEOBUF_ERROR:
358 b->flags |= V4L2_BUF_FLAG_ERROR;
359 /* fall through */
360 case VIDEOBUF_DONE:
361 b->flags |= V4L2_BUF_FLAG_DONE;
362 break;
363 case VIDEOBUF_NEEDS_INIT:
364 case VIDEOBUF_IDLE:
365 /* nothing */
366 break;
367 }
368
369 b->field = vb->field;
370 b->timestamp = vb->ts;
371 b->bytesused = vb->size;
372 b->sequence = vb->field_count >> 1;
373 }
374
375 int videobuf_mmap_free(struct videobuf_queue *q)
376 {
377 int ret;
378 videobuf_queue_lock(q);
379 ret = __videobuf_free(q);
380 videobuf_queue_unlock(q);
381 return ret;
382 }
383 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
384
385 /* Locking: Caller holds q->vb_lock */
386 int __videobuf_mmap_setup(struct videobuf_queue *q,
387 unsigned int bcount, unsigned int bsize,
388 enum v4l2_memory memory)
389 {
390 unsigned int i;
391 int err;
392
393 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
394
395 err = __videobuf_free(q);
396 if (0 != err)
397 return err;
398
399 /* Allocate and initialize buffers */
400 for (i = 0; i < bcount; i++) {
401 q->bufs[i] = videobuf_alloc_vb(q);
402
403 if (NULL == q->bufs[i])
404 break;
405
406 q->bufs[i]->i = i;
407 q->bufs[i]->memory = memory;
408 q->bufs[i]->bsize = bsize;
409 switch (memory) {
410 case V4L2_MEMORY_MMAP:
411 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
412 break;
413 case V4L2_MEMORY_USERPTR:
414 case V4L2_MEMORY_OVERLAY:
415 case V4L2_MEMORY_DMABUF:
416 /* nothing */
417 break;
418 }
419 }
420
421 if (!i)
422 return -ENOMEM;
423
424 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
425
426 return i;
427 }
428 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
429
430 int videobuf_mmap_setup(struct videobuf_queue *q,
431 unsigned int bcount, unsigned int bsize,
432 enum v4l2_memory memory)
433 {
434 int ret;
435 videobuf_queue_lock(q);
436 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
437 videobuf_queue_unlock(q);
438 return ret;
439 }
440 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
441
442 int videobuf_reqbufs(struct videobuf_queue *q,
443 struct v4l2_requestbuffers *req)
444 {
445 unsigned int size, count;
446 int retval;
447
448 if (req->memory != V4L2_MEMORY_MMAP &&
449 req->memory != V4L2_MEMORY_USERPTR &&
450 req->memory != V4L2_MEMORY_OVERLAY) {
451 dprintk(1, "reqbufs: memory type invalid\n");
452 return -EINVAL;
453 }
454
455 videobuf_queue_lock(q);
456 if (req->type != q->type) {
457 dprintk(1, "reqbufs: queue type invalid\n");
458 retval = -EINVAL;
459 goto done;
460 }
461
462 if (q->streaming) {
463 dprintk(1, "reqbufs: streaming already exists\n");
464 retval = -EBUSY;
465 goto done;
466 }
467 if (!list_empty(&q->stream)) {
468 dprintk(1, "reqbufs: stream running\n");
469 retval = -EBUSY;
470 goto done;
471 }
472
473 if (req->count == 0) {
474 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
475 retval = __videobuf_free(q);
476 goto done;
477 }
478
479 count = req->count;
480 if (count > VIDEO_MAX_FRAME)
481 count = VIDEO_MAX_FRAME;
482 size = 0;
483 q->ops->buf_setup(q, &count, &size);
484 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
485 count, size,
486 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
487
488 retval = __videobuf_mmap_setup(q, count, size, req->memory);
489 if (retval < 0) {
490 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
491 goto done;
492 }
493
494 req->count = retval;
495 retval = 0;
496
497 done:
498 videobuf_queue_unlock(q);
499 return retval;
500 }
501 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
502
503 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
504 {
505 int ret = -EINVAL;
506
507 videobuf_queue_lock(q);
508 if (unlikely(b->type != q->type)) {
509 dprintk(1, "querybuf: Wrong type.\n");
510 goto done;
511 }
512 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
513 dprintk(1, "querybuf: index out of range.\n");
514 goto done;
515 }
516 if (unlikely(NULL == q->bufs[b->index])) {
517 dprintk(1, "querybuf: buffer is null.\n");
518 goto done;
519 }
520
521 videobuf_status(q, b, q->bufs[b->index], q->type);
522
523 ret = 0;
524 done:
525 videobuf_queue_unlock(q);
526 return ret;
527 }
528 EXPORT_SYMBOL_GPL(videobuf_querybuf);
529
530 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
531 {
532 struct videobuf_buffer *buf;
533 enum v4l2_field field;
534 unsigned long flags = 0;
535 int retval;
536
537 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
538
539 if (b->memory == V4L2_MEMORY_MMAP)
540 down_read(&current->mm->mmap_sem);
541
542 videobuf_queue_lock(q);
543 retval = -EBUSY;
544 if (q->reading) {
545 dprintk(1, "qbuf: Reading running...\n");
546 goto done;
547 }
548 retval = -EINVAL;
549 if (b->type != q->type) {
550 dprintk(1, "qbuf: Wrong type.\n");
551 goto done;
552 }
553 if (b->index >= VIDEO_MAX_FRAME) {
554 dprintk(1, "qbuf: index out of range.\n");
555 goto done;
556 }
557 buf = q->bufs[b->index];
558 if (NULL == buf) {
559 dprintk(1, "qbuf: buffer is null.\n");
560 goto done;
561 }
562 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
563 if (buf->memory != b->memory) {
564 dprintk(1, "qbuf: memory type is wrong.\n");
565 goto done;
566 }
567 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
568 dprintk(1, "qbuf: buffer is already queued or active.\n");
569 goto done;
570 }
571
572 switch (b->memory) {
573 case V4L2_MEMORY_MMAP:
574 if (0 == buf->baddr) {
575 dprintk(1, "qbuf: mmap requested "
576 "but buffer addr is zero!\n");
577 goto done;
578 }
579 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
580 || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
581 || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT
582 || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) {
583 buf->size = b->bytesused;
584 buf->field = b->field;
585 buf->ts = b->timestamp;
586 }
587 break;
588 case V4L2_MEMORY_USERPTR:
589 if (b->length < buf->bsize) {
590 dprintk(1, "qbuf: buffer length is not enough\n");
591 goto done;
592 }
593 if (VIDEOBUF_NEEDS_INIT != buf->state &&
594 buf->baddr != b->m.userptr)
595 q->ops->buf_release(q, buf);
596 buf->baddr = b->m.userptr;
597 break;
598 case V4L2_MEMORY_OVERLAY:
599 buf->boff = b->m.offset;
600 break;
601 default:
602 dprintk(1, "qbuf: wrong memory type\n");
603 goto done;
604 }
605
606 dprintk(1, "qbuf: requesting next field\n");
607 field = videobuf_next_field(q);
608 retval = q->ops->buf_prepare(q, buf, field);
609 if (0 != retval) {
610 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
611 goto done;
612 }
613
614 list_add_tail(&buf->stream, &q->stream);
615 if (q->streaming) {
616 spin_lock_irqsave(q->irqlock, flags);
617 q->ops->buf_queue(q, buf);
618 spin_unlock_irqrestore(q->irqlock, flags);
619 }
620 dprintk(1, "qbuf: succeeded\n");
621 retval = 0;
622 wake_up_interruptible_sync(&q->wait);
623
624 done:
625 videobuf_queue_unlock(q);
626
627 if (b->memory == V4L2_MEMORY_MMAP)
628 up_read(&current->mm->mmap_sem);
629
630 return retval;
631 }
632 EXPORT_SYMBOL_GPL(videobuf_qbuf);
633
634 /* Locking: Caller holds q->vb_lock */
635 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
636 {
637 int retval;
638
639 checks:
640 if (!q->streaming) {
641 dprintk(1, "next_buffer: Not streaming\n");
642 retval = -EINVAL;
643 goto done;
644 }
645
646 if (list_empty(&q->stream)) {
647 if (noblock) {
648 retval = -EAGAIN;
649 dprintk(2, "next_buffer: no buffers to dequeue\n");
650 goto done;
651 } else {
652 dprintk(2, "next_buffer: waiting on buffer\n");
653
654 /* Drop lock to avoid deadlock with qbuf */
655 videobuf_queue_unlock(q);
656
657 /* Checking list_empty and streaming is safe without
658 * locks because we goto checks to validate while
659 * holding locks before proceeding */
660 retval = wait_event_interruptible(q->wait,
661 !list_empty(&q->stream) || !q->streaming);
662 videobuf_queue_lock(q);
663
664 if (retval)
665 goto done;
666
667 goto checks;
668 }
669 }
670
671 retval = 0;
672
673 done:
674 return retval;
675 }
676
677 /* Locking: Caller holds q->vb_lock */
678 static int stream_next_buffer(struct videobuf_queue *q,
679 struct videobuf_buffer **vb, int nonblocking)
680 {
681 int retval;
682 struct videobuf_buffer *buf = NULL;
683
684 retval = stream_next_buffer_check_queue(q, nonblocking);
685 if (retval)
686 goto done;
687
688 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
689 retval = videobuf_waiton(q, buf, nonblocking, 1);
690 if (retval < 0)
691 goto done;
692
693 *vb = buf;
694 done:
695 return retval;
696 }
697
698 int videobuf_dqbuf(struct videobuf_queue *q,
699 struct v4l2_buffer *b, int nonblocking)
700 {
701 struct videobuf_buffer *buf = NULL;
702 int retval;
703
704 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
705
706 memset(b, 0, sizeof(*b));
707 videobuf_queue_lock(q);
708
709 retval = stream_next_buffer(q, &buf, nonblocking);
710 if (retval < 0) {
711 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
712 goto done;
713 }
714
715 switch (buf->state) {
716 case VIDEOBUF_ERROR:
717 dprintk(1, "dqbuf: state is error\n");
718 break;
719 case VIDEOBUF_DONE:
720 dprintk(1, "dqbuf: state is done\n");
721 break;
722 default:
723 dprintk(1, "dqbuf: state invalid\n");
724 retval = -EINVAL;
725 goto done;
726 }
727 CALL(q, sync, q, buf);
728 videobuf_status(q, b, buf, q->type);
729 list_del(&buf->stream);
730 buf->state = VIDEOBUF_IDLE;
731 b->flags &= ~V4L2_BUF_FLAG_DONE;
732 done:
733 videobuf_queue_unlock(q);
734 return retval;
735 }
736 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
737
738 int videobuf_streamon(struct videobuf_queue *q)
739 {
740 struct videobuf_buffer *buf;
741 unsigned long flags = 0;
742 int retval;
743
744 videobuf_queue_lock(q);
745 retval = -EBUSY;
746 if (q->reading)
747 goto done;
748 retval = 0;
749 if (q->streaming)
750 goto done;
751 q->streaming = 1;
752 spin_lock_irqsave(q->irqlock, flags);
753 list_for_each_entry(buf, &q->stream, stream)
754 if (buf->state == VIDEOBUF_PREPARED)
755 q->ops->buf_queue(q, buf);
756 spin_unlock_irqrestore(q->irqlock, flags);
757
758 wake_up_interruptible_sync(&q->wait);
759 done:
760 videobuf_queue_unlock(q);
761 return retval;
762 }
763 EXPORT_SYMBOL_GPL(videobuf_streamon);
764
765 /* Locking: Caller holds q->vb_lock */
766 static int __videobuf_streamoff(struct videobuf_queue *q)
767 {
768 if (!q->streaming)
769 return -EINVAL;
770
771 videobuf_queue_cancel(q);
772
773 return 0;
774 }
775
776 int videobuf_streamoff(struct videobuf_queue *q)
777 {
778 int retval;
779
780 videobuf_queue_lock(q);
781 retval = __videobuf_streamoff(q);
782 videobuf_queue_unlock(q);
783
784 return retval;
785 }
786 EXPORT_SYMBOL_GPL(videobuf_streamoff);
787
788 /* Locking: Caller holds q->vb_lock */
789 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
790 char __user *data,
791 size_t count, loff_t *ppos)
792 {
793 enum v4l2_field field;
794 unsigned long flags = 0;
795 int retval;
796
797 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
798
799 /* setup stuff */
800 q->read_buf = videobuf_alloc_vb(q);
801 if (NULL == q->read_buf)
802 return -ENOMEM;
803
804 q->read_buf->memory = V4L2_MEMORY_USERPTR;
805 q->read_buf->baddr = (unsigned long)data;
806 q->read_buf->bsize = count;
807
808 field = videobuf_next_field(q);
809 retval = q->ops->buf_prepare(q, q->read_buf, field);
810 if (0 != retval)
811 goto done;
812
813 /* start capture & wait */
814 spin_lock_irqsave(q->irqlock, flags);
815 q->ops->buf_queue(q, q->read_buf);
816 spin_unlock_irqrestore(q->irqlock, flags);
817 retval = videobuf_waiton(q, q->read_buf, 0, 0);
818 if (0 == retval) {
819 CALL(q, sync, q, q->read_buf);
820 if (VIDEOBUF_ERROR == q->read_buf->state)
821 retval = -EIO;
822 else
823 retval = q->read_buf->size;
824 }
825
826 done:
827 /* cleanup */
828 q->ops->buf_release(q, q->read_buf);
829 kfree(q->read_buf);
830 q->read_buf = NULL;
831 return retval;
832 }
833
834 static int __videobuf_copy_to_user(struct videobuf_queue *q,
835 struct videobuf_buffer *buf,
836 char __user *data, size_t count,
837 int nonblocking)
838 {
839 void *vaddr = CALLPTR(q, vaddr, buf);
840
841 /* copy to userspace */
842 if (count > buf->size - q->read_off)
843 count = buf->size - q->read_off;
844
845 if (copy_to_user(data, vaddr + q->read_off, count))
846 return -EFAULT;
847
848 return count;
849 }
850
851 static int __videobuf_copy_stream(struct videobuf_queue *q,
852 struct videobuf_buffer *buf,
853 char __user *data, size_t count, size_t pos,
854 int vbihack, int nonblocking)
855 {
856 unsigned int *fc = CALLPTR(q, vaddr, buf);
857
858 if (vbihack) {
859 /* dirty, undocumented hack -- pass the frame counter
860 * within the last four bytes of each vbi data block.
861 * We need that one to maintain backward compatibility
862 * to all vbi decoding software out there ... */
863 fc += (buf->size >> 2) - 1;
864 *fc = buf->field_count >> 1;
865 dprintk(1, "vbihack: %d\n", *fc);
866 }
867
868 /* copy stuff using the common method */
869 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
870
871 if ((count == -EFAULT) && (pos == 0))
872 return -EFAULT;
873
874 return count;
875 }
876
877 ssize_t videobuf_read_one(struct videobuf_queue *q,
878 char __user *data, size_t count, loff_t *ppos,
879 int nonblocking)
880 {
881 enum v4l2_field field;
882 unsigned long flags = 0;
883 unsigned size = 0, nbufs = 1;
884 int retval;
885
886 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
887
888 videobuf_queue_lock(q);
889
890 q->ops->buf_setup(q, &nbufs, &size);
891
892 if (NULL == q->read_buf &&
893 count >= size &&
894 !nonblocking) {
895 retval = videobuf_read_zerocopy(q, data, count, ppos);
896 if (retval >= 0 || retval == -EIO)
897 /* ok, all done */
898 goto done;
899 /* fallback to kernel bounce buffer on failures */
900 }
901
902 if (NULL == q->read_buf) {
903 /* need to capture a new frame */
904 retval = -ENOMEM;
905 q->read_buf = videobuf_alloc_vb(q);
906
907 dprintk(1, "video alloc=0x%p\n", q->read_buf);
908 if (NULL == q->read_buf)
909 goto done;
910 q->read_buf->memory = V4L2_MEMORY_USERPTR;
911 q->read_buf->bsize = count; /* preferred size */
912 field = videobuf_next_field(q);
913 retval = q->ops->buf_prepare(q, q->read_buf, field);
914
915 if (0 != retval) {
916 kfree(q->read_buf);
917 q->read_buf = NULL;
918 goto done;
919 }
920
921 spin_lock_irqsave(q->irqlock, flags);
922 q->ops->buf_queue(q, q->read_buf);
923 spin_unlock_irqrestore(q->irqlock, flags);
924
925 q->read_off = 0;
926 }
927
928 /* wait until capture is done */
929 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
930 if (0 != retval)
931 goto done;
932
933 CALL(q, sync, q, q->read_buf);
934
935 if (VIDEOBUF_ERROR == q->read_buf->state) {
936 /* catch I/O errors */
937 q->ops->buf_release(q, q->read_buf);
938 kfree(q->read_buf);
939 q->read_buf = NULL;
940 retval = -EIO;
941 goto done;
942 }
943
944 /* Copy to userspace */
945 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
946 if (retval < 0)
947 goto done;
948
949 q->read_off += retval;
950 if (q->read_off == q->read_buf->size) {
951 /* all data copied, cleanup */
952 q->ops->buf_release(q, q->read_buf);
953 kfree(q->read_buf);
954 q->read_buf = NULL;
955 }
956
957 done:
958 videobuf_queue_unlock(q);
959 return retval;
960 }
961 EXPORT_SYMBOL_GPL(videobuf_read_one);
962
963 /* Locking: Caller holds q->vb_lock */
964 static int __videobuf_read_start(struct videobuf_queue *q)
965 {
966 enum v4l2_field field;
967 unsigned long flags = 0;
968 unsigned int count = 0, size = 0;
969 int err, i;
970
971 q->ops->buf_setup(q, &count, &size);
972 if (count < 2)
973 count = 2;
974 if (count > VIDEO_MAX_FRAME)
975 count = VIDEO_MAX_FRAME;
976 size = PAGE_ALIGN(size);
977
978 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
979 if (err < 0)
980 return err;
981
982 count = err;
983
984 for (i = 0; i < count; i++) {
985 field = videobuf_next_field(q);
986 err = q->ops->buf_prepare(q, q->bufs[i], field);
987 if (err)
988 return err;
989 list_add_tail(&q->bufs[i]->stream, &q->stream);
990 }
991 spin_lock_irqsave(q->irqlock, flags);
992 for (i = 0; i < count; i++)
993 q->ops->buf_queue(q, q->bufs[i]);
994 spin_unlock_irqrestore(q->irqlock, flags);
995 q->reading = 1;
996 return 0;
997 }
998
999 static void __videobuf_read_stop(struct videobuf_queue *q)
1000 {
1001 int i;
1002
1003 videobuf_queue_cancel(q);
1004 __videobuf_free(q);
1005 INIT_LIST_HEAD(&q->stream);
1006 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1007 if (NULL == q->bufs[i])
1008 continue;
1009 kfree(q->bufs[i]);
1010 q->bufs[i] = NULL;
1011 }
1012 q->read_buf = NULL;
1013 }
1014
1015 int videobuf_read_start(struct videobuf_queue *q)
1016 {
1017 int rc;
1018
1019 videobuf_queue_lock(q);
1020 rc = __videobuf_read_start(q);
1021 videobuf_queue_unlock(q);
1022
1023 return rc;
1024 }
1025 EXPORT_SYMBOL_GPL(videobuf_read_start);
1026
1027 void videobuf_read_stop(struct videobuf_queue *q)
1028 {
1029 videobuf_queue_lock(q);
1030 __videobuf_read_stop(q);
1031 videobuf_queue_unlock(q);
1032 }
1033 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1034
1035 void videobuf_stop(struct videobuf_queue *q)
1036 {
1037 videobuf_queue_lock(q);
1038
1039 if (q->streaming)
1040 __videobuf_streamoff(q);
1041
1042 if (q->reading)
1043 __videobuf_read_stop(q);
1044
1045 videobuf_queue_unlock(q);
1046 }
1047 EXPORT_SYMBOL_GPL(videobuf_stop);
1048
1049 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1050 char __user *data, size_t count, loff_t *ppos,
1051 int vbihack, int nonblocking)
1052 {
1053 int rc, retval;
1054 unsigned long flags = 0;
1055
1056 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1057
1058 dprintk(2, "%s\n", __func__);
1059 videobuf_queue_lock(q);
1060 retval = -EBUSY;
1061 if (q->streaming)
1062 goto done;
1063 if (!q->reading) {
1064 retval = __videobuf_read_start(q);
1065 if (retval < 0)
1066 goto done;
1067 }
1068
1069 retval = 0;
1070 while (count > 0) {
1071 /* get / wait for data */
1072 if (NULL == q->read_buf) {
1073 q->read_buf = list_entry(q->stream.next,
1074 struct videobuf_buffer,
1075 stream);
1076 list_del(&q->read_buf->stream);
1077 q->read_off = 0;
1078 }
1079 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1080 if (rc < 0) {
1081 if (0 == retval)
1082 retval = rc;
1083 break;
1084 }
1085
1086 if (q->read_buf->state == VIDEOBUF_DONE) {
1087 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1088 retval, vbihack, nonblocking);
1089 if (rc < 0) {
1090 retval = rc;
1091 break;
1092 }
1093 retval += rc;
1094 count -= rc;
1095 q->read_off += rc;
1096 } else {
1097 /* some error */
1098 q->read_off = q->read_buf->size;
1099 if (0 == retval)
1100 retval = -EIO;
1101 }
1102
1103 /* requeue buffer when done with copying */
1104 if (q->read_off == q->read_buf->size) {
1105 list_add_tail(&q->read_buf->stream,
1106 &q->stream);
1107 spin_lock_irqsave(q->irqlock, flags);
1108 q->ops->buf_queue(q, q->read_buf);
1109 spin_unlock_irqrestore(q->irqlock, flags);
1110 q->read_buf = NULL;
1111 }
1112 if (retval < 0)
1113 break;
1114 }
1115
1116 done:
1117 videobuf_queue_unlock(q);
1118 return retval;
1119 }
1120 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1121
1122 unsigned int videobuf_poll_stream(struct file *file,
1123 struct videobuf_queue *q,
1124 poll_table *wait)
1125 {
1126 unsigned long req_events = poll_requested_events(wait);
1127 struct videobuf_buffer *buf = NULL;
1128 unsigned int rc = 0;
1129
1130 videobuf_queue_lock(q);
1131 if (q->streaming) {
1132 if (!list_empty(&q->stream))
1133 buf = list_entry(q->stream.next,
1134 struct videobuf_buffer, stream);
1135 } else if (req_events & (POLLIN | POLLRDNORM)) {
1136 if (!q->reading)
1137 __videobuf_read_start(q);
1138 if (!q->reading) {
1139 rc = POLLERR;
1140 } else if (NULL == q->read_buf) {
1141 q->read_buf = list_entry(q->stream.next,
1142 struct videobuf_buffer,
1143 stream);
1144 list_del(&q->read_buf->stream);
1145 q->read_off = 0;
1146 }
1147 buf = q->read_buf;
1148 }
1149 if (!buf)
1150 rc = POLLERR;
1151
1152 if (0 == rc) {
1153 poll_wait(file, &buf->done, wait);
1154 if (buf->state == VIDEOBUF_DONE ||
1155 buf->state == VIDEOBUF_ERROR) {
1156 switch (q->type) {
1157 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1158 case V4L2_BUF_TYPE_VBI_OUTPUT:
1159 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1160 case V4L2_BUF_TYPE_SDR_OUTPUT:
1161 rc = POLLOUT | POLLWRNORM;
1162 break;
1163 default:
1164 rc = POLLIN | POLLRDNORM;
1165 break;
1166 }
1167 }
1168 }
1169 videobuf_queue_unlock(q);
1170 return rc;
1171 }
1172 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1173
1174 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1175 {
1176 int rc = -EINVAL;
1177 int i;
1178
1179 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1180
1181 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1182 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1183 return -EINVAL;
1184 }
1185
1186 videobuf_queue_lock(q);
1187 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1188 struct videobuf_buffer *buf = q->bufs[i];
1189
1190 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1191 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1192 rc = CALL(q, mmap_mapper, q, buf, vma);
1193 break;
1194 }
1195 }
1196 videobuf_queue_unlock(q);
1197
1198 return rc;
1199 }
1200 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
Linux with added FPC-III support