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V4L/DVB (6251): Replace video-buf to a more generic approach
[linux-2.6-block.git] / drivers / media / video / videobuf-core.c
CommitLineData
7a7d9a89
MCC		 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) if (unlikely((is) != (should))) \
26 { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
27
28static int debug = 0;
29module_param(debug, int, 0644);
30
31MODULE_DESCRIPTION("helper module to manage video4linux buffers");
32MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
33MODULE_LICENSE("GPL");
34
35#define dprintk(level, fmt, arg...) if (debug >= level) \
36 printk(KERN_DEBUG "vbuf: " fmt , ## arg)
37
38/* --------------------------------------------------------------------- */
39
40#define CALL(q, f, arg...) \
41 ( (q->int_ops->f)? q->int_ops->f(arg) : 0)
42
43void* videobuf_alloc(struct videobuf_queue* q)
44{
45 struct videobuf_buffer *vb;
46
47 BUG_ON (q->msize<sizeof(*vb));
48
49 if (!q->int_ops || !q->int_ops->alloc) {
50 printk(KERN_ERR "No specific ops defined!\n");
51 BUG();
52 }
53
54 vb = q->int_ops->alloc(q->msize);
55
56 if (NULL != vb) {
57 init_waitqueue_head(&vb->done);
58 vb->magic = MAGIC_BUFFER;
59 }
60
61 return vb;
62}
63
64int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
65{
66 int retval = 0;
67 DECLARE_WAITQUEUE(wait, current);
68
69 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
70 add_wait_queue(&vb->done, &wait);
71 while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
72 if (non_blocking) {
73 retval = -EAGAIN;
74 break;
75 }
76 set_current_state(intr ? TASK_INTERRUPTIBLE
77 : TASK_UNINTERRUPTIBLE);
78 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
79 schedule();
80 set_current_state(TASK_RUNNING);
81 if (intr && signal_pending(current)) {
82 dprintk(1,"buffer waiton: -EINTR\n");
83 retval = -EINTR;
84 break;
85 }
86 }
87 remove_wait_queue(&vb->done, &wait);
88 return retval;
89}
90
91int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
92 struct v4l2_framebuffer *fbuf)
93{
94 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
95 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
96
97 return CALL(q,iolock,q,vb,fbuf);
98}
99
100/* --------------------------------------------------------------------- */
101
102
103void videobuf_queue_init(struct videobuf_queue* q,
104 struct videobuf_queue_ops *ops,
105 void *dev,
106 spinlock_t *irqlock,
107 enum v4l2_buf_type type,
108 enum v4l2_field field,
109 unsigned int msize,
110 void *priv)
111{
112 memset(q,0,sizeof(*q));
113 q->irqlock = irqlock;
114 q->dev = dev;
115 q->type = type;
116 q->field = field;
117 q->msize = msize;
118 q->ops = ops;
119 q->priv_data = priv;
120
121 /* All buffer operations are mandatory */
122 BUG_ON (!q->ops->buf_setup);
123 BUG_ON (!q->ops->buf_prepare);
124 BUG_ON (!q->ops->buf_queue);
125 BUG_ON (!q->ops->buf_release);
126
127 mutex_init(&q->lock);
128 INIT_LIST_HEAD(&q->stream);
129}
130
131int videobuf_queue_is_busy(struct videobuf_queue *q)
132{
133 int i;
134
135 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
136
137 if (q->streaming) {
138 dprintk(1,"busy: streaming active\n");
139 return 1;
140 }
141 if (q->reading) {
142 dprintk(1,"busy: pending read #1\n");
143 return 1;
144 }
145 if (q->read_buf) {
146 dprintk(1,"busy: pending read #2\n");
147 return 1;
148 }
149 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
150 if (NULL == q->bufs[i])
151 continue;
152 if (CALL(q,is_mmapped,q->bufs[i])) {
153 dprintk(1,"busy: buffer #%d mapped\n",i);
154 return 1;
155 }
156 if (q->bufs[i]->state == STATE_QUEUED) {
157 dprintk(1,"busy: buffer #%d queued\n",i);
158 return 1;
159 }
160 if (q->bufs[i]->state == STATE_ACTIVE) {
161 dprintk(1,"busy: buffer #%d avtive\n",i);
162 return 1;
163 }
164 }
165 return 0;
166}
167
168void videobuf_queue_cancel(struct videobuf_queue *q)
169{
170 unsigned long flags=0;
171 int i;
172
173 /* remove queued buffers from list */
174 if (q->irqlock)
175 spin_lock_irqsave(q->irqlock,flags);
176 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
177 if (NULL == q->bufs[i])
178 continue;
179 if (q->bufs[i]->state == STATE_QUEUED) {
180 list_del(&q->bufs[i]->queue);
181 q->bufs[i]->state = STATE_ERROR;
182 }
183 }
184 if (q->irqlock)
185 spin_unlock_irqrestore(q->irqlock,flags);
186
187 /* free all buffers + clear queue */
188 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
189 if (NULL == q->bufs[i])
190 continue;
191 q->ops->buf_release(q,q->bufs[i]);
192 }
193 INIT_LIST_HEAD(&q->stream);
194}
195
196/* --------------------------------------------------------------------- */
197
198enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
199{
200 enum v4l2_field field = q->field;
201
202 BUG_ON(V4L2_FIELD_ANY == field);
203
204 if (V4L2_FIELD_ALTERNATE == field) {
205 if (V4L2_FIELD_TOP == q->last) {
206 field = V4L2_FIELD_BOTTOM;
207 q->last = V4L2_FIELD_BOTTOM;
208 } else {
209 field = V4L2_FIELD_TOP;
210 q->last = V4L2_FIELD_TOP;
211 }
212 }
213 return field;
214}
215
216static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
217 struct videobuf_buffer *vb, enum v4l2_buf_type type)
218{
219 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
220 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
221
222 b->index = vb->i;
223 b->type = type;
224
225 b->memory = vb->memory;
226 switch (b->memory) {
227 case V4L2_MEMORY_MMAP:
228 b->m.offset = vb->boff;
229 b->length = vb->bsize;
230 break;
231 case V4L2_MEMORY_USERPTR:
232 b->m.userptr = vb->baddr;
233 b->length = vb->bsize;
234 break;
235 case V4L2_MEMORY_OVERLAY:
236 b->m.offset = vb->boff;
237 break;
238 }
239
240 b->flags = 0;
241 if (CALL(q,is_mmapped,vb))
242 b->flags |= V4L2_BUF_FLAG_MAPPED;
243
244 switch (vb->state) {
245 case STATE_PREPARED:
246 case STATE_QUEUED:
247 case STATE_ACTIVE:
248 b->flags |= V4L2_BUF_FLAG_QUEUED;
249 break;
250 case STATE_DONE:
251 case STATE_ERROR:
252 b->flags |= V4L2_BUF_FLAG_DONE;
253 break;
254 case STATE_NEEDS_INIT:
255 case STATE_IDLE:
256 /* nothing */
257 break;
258 }
259
260 if (vb->input != UNSET) {
261 b->flags |= V4L2_BUF_FLAG_INPUT;
262 b->input = vb->input;
263 }
264
265 b->field = vb->field;
266 b->timestamp = vb->ts;
267 b->bytesused = vb->size;
268 b->sequence = vb->field_count >> 1;
269}
270
271int videobuf_reqbufs(struct videobuf_queue *q,
272 struct v4l2_requestbuffers *req)
273{
274 unsigned int size,count;
275 int retval;
276
277 if (req->type != q->type) {
278 dprintk(1,"reqbufs: queue type invalid\n");
279 return -EINVAL;
280 }
281 if (req->count < 1) {
282 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
283 return -EINVAL;
284 }
285 if (req->memory != V4L2_MEMORY_MMAP &&
286 req->memory != V4L2_MEMORY_USERPTR &&
287 req->memory != V4L2_MEMORY_OVERLAY) {
288 dprintk(1,"reqbufs: memory type invalid\n");
289 return -EINVAL;
290 }
291
292 if (q->streaming) {
293 dprintk(1,"reqbufs: streaming already exists\n");
294 return -EBUSY;
295 }
296 if (!list_empty(&q->stream)) {
297 dprintk(1,"reqbufs: stream running\n");
298 return -EBUSY;
299 }
300
301 mutex_lock(&q->lock);
302 count = req->count;
303 if (count > VIDEO_MAX_FRAME)
304 count = VIDEO_MAX_FRAME;
305 size = 0;
306 q->ops->buf_setup(q,&count,&size);
307 size = PAGE_ALIGN(size);
308 dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
309 count, size, (count*size)>>PAGE_SHIFT);
310
311 retval = videobuf_mmap_setup(q,count,size,req->memory);
312 if (retval < 0) {
313 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
314 goto done;
315 }
316
317 req->count = count;
318
319 done:
320 mutex_unlock(&q->lock);
321 return retval;
322}
323
324int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
325{
326 if (unlikely(b->type != q->type)) {
327 dprintk(1,"querybuf: Wrong type.\n");
328 return -EINVAL;
329 }
330 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
331 dprintk(1,"querybuf: index out of range.\n");
332 return -EINVAL;
333 }
334 if (unlikely(NULL == q->bufs[b->index])) {
335 dprintk(1,"querybuf: buffer is null.\n");
336 return -EINVAL;
337 }
338 videobuf_status(q,b,q->bufs[b->index],q->type);
339 return 0;
340}
341
342int videobuf_qbuf(struct videobuf_queue *q,
343 struct v4l2_buffer *b)
344{
345 struct videobuf_buffer *buf;
346 enum v4l2_field field;
347 unsigned long flags=0;
348 int retval;
349
350 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
351
352 mutex_lock(&q->lock);
353 retval = -EBUSY;
354 if (q->reading) {
355 dprintk(1,"qbuf: Reading running...\n");
356 goto done;
357 }
358 retval = -EINVAL;
359 if (b->type != q->type) {
360 dprintk(1,"qbuf: Wrong type.\n");
361 goto done;
362 }
363 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
364 dprintk(1,"qbuf: index out of range.\n");
365 goto done;
366 }
367 buf = q->bufs[b->index];
368 if (NULL == buf) {
369 dprintk(1,"qbuf: buffer is null.\n");
370 goto done;
371 }
372 MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
373 if (buf->memory != b->memory) {
374 dprintk(1,"qbuf: memory type is wrong.\n");
375 goto done;
376 }
377 if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
378 dprintk(1,"qbuf: buffer is already queued or active.\n");
379 goto done;
380 }
381
382 if (b->flags & V4L2_BUF_FLAG_INPUT) {
383 if (b->input >= q->inputs) {
384 dprintk(1,"qbuf: wrong input.\n");
385 goto done;
386 }
387 buf->input = b->input;
388 } else {
389 buf->input = UNSET;
390 }
391
392 switch (b->memory) {
393 case V4L2_MEMORY_MMAP:
394 if (0 == buf->baddr) {
395 dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
396 goto done;
397 }
398 break;
399 case V4L2_MEMORY_USERPTR:
400 if (b->length < buf->bsize) {
401 dprintk(1,"qbuf: buffer length is not enough\n");
402 goto done;
403 }
404 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
405 q->ops->buf_release(q,buf);
406 buf->baddr = b->m.userptr;
407 break;
408 case V4L2_MEMORY_OVERLAY:
409 buf->boff = b->m.offset;
410 break;
411 default:
412 dprintk(1,"qbuf: wrong memory type\n");
413 goto done;
414 }
415
416 dprintk(1,"qbuf: requesting next field\n");
417 field = videobuf_next_field(q);
418 retval = q->ops->buf_prepare(q,buf,field);
419 if (0 != retval) {
420 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
421 goto done;
422 }
423
424 list_add_tail(&buf->stream,&q->stream);
425 if (q->streaming) {
426 if (q->irqlock)
427 spin_lock_irqsave(q->irqlock,flags);
428 q->ops->buf_queue(q,buf);
429 if (q->irqlock)
430 spin_unlock_irqrestore(q->irqlock,flags);
431 }
432 dprintk(1,"qbuf: succeded\n");
433 retval = 0;
434
435 done:
436 mutex_unlock(&q->lock);
437 return retval;
438}
439
440int videobuf_dqbuf(struct videobuf_queue *q,
441 struct v4l2_buffer *b, int nonblocking)
442{
443 struct videobuf_buffer *buf;
444 int retval;
445
446 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
447
448 mutex_lock(&q->lock);
449 retval = -EBUSY;
450 if (q->reading) {
451 dprintk(1,"dqbuf: Reading running...\n");
452 goto done;
453 }
454 retval = -EINVAL;
455 if (b->type != q->type) {
456 dprintk(1,"dqbuf: Wrong type.\n");
457 goto done;
458 }
459 if (list_empty(&q->stream)) {
460 dprintk(1,"dqbuf: stream running\n");
461 goto done;
462 }
463 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
464 retval = videobuf_waiton(buf, nonblocking, 1);
465 if (retval < 0) {
466 dprintk(1,"dqbuf: waiton returned %d\n",retval);
467 goto done;
468 }
469 switch (buf->state) {
470 case STATE_ERROR:
471 dprintk(1,"dqbuf: state is error\n");
472 retval = -EIO;
473 CALL(q,sync,q, buf);
474 buf->state = STATE_IDLE;
475 break;
476 case STATE_DONE:
477 dprintk(1,"dqbuf: state is done\n");
478 CALL(q,sync,q, buf);
479 buf->state = STATE_IDLE;
480 break;
481 default:
482 dprintk(1,"dqbuf: state invalid\n");
483 retval = -EINVAL;
484 goto done;
485 }
486 list_del(&buf->stream);
487 memset(b,0,sizeof(*b));
488 videobuf_status(q,b,buf,q->type);
489
490 done:
491 mutex_unlock(&q->lock);
492 return retval;
493}
494
495int videobuf_streamon(struct videobuf_queue *q)
496{
497 struct videobuf_buffer *buf;
498 struct list_head *list;
499 unsigned long flags=0;
500 int retval;
501
502 mutex_lock(&q->lock);
503 retval = -EBUSY;
504 if (q->reading)
505 goto done;
506 retval = 0;
507 if (q->streaming)
508 goto done;
509 q->streaming = 1;
510 if (q->irqlock)
511 spin_lock_irqsave(q->irqlock,flags);
512 list_for_each(list,&q->stream) {
513 buf = list_entry(list, struct videobuf_buffer, stream);
514 if (buf->state == STATE_PREPARED)
515 q->ops->buf_queue(q,buf);
516 }
517 if (q->irqlock)
518 spin_unlock_irqrestore(q->irqlock,flags);
519
520 done:
521 mutex_unlock(&q->lock);
522 return retval;
523}
524
525int videobuf_streamoff(struct videobuf_queue *q)
526{
527 int retval = -EINVAL;
528
529 mutex_lock(&q->lock);
530 if (!q->streaming)
531 goto done;
532 videobuf_queue_cancel(q);
533 q->streaming = 0;
534 retval = 0;
535
536 done:
537 mutex_unlock(&q->lock);
538 return retval;
539}
540
541static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
542 char __user *data,
543 size_t count, loff_t *ppos)
544{
545 enum v4l2_field field;
546 unsigned long flags=0;
547 int retval;
548
549 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
550
551 /* setup stuff */
552 q->read_buf = videobuf_alloc(q);
553 if (NULL == q->read_buf)
554 return -ENOMEM;
555
556 q->read_buf->memory = V4L2_MEMORY_USERPTR;
557 q->read_buf->baddr = (unsigned long)data;
558 q->read_buf->bsize = count;
559
560 field = videobuf_next_field(q);
561 retval = q->ops->buf_prepare(q,q->read_buf,field);
562 if (0 != retval)
563 goto done;
564
565 /* start capture & wait */
566 if (q->irqlock)
567 spin_lock_irqsave(q->irqlock,flags);
568 q->ops->buf_queue(q,q->read_buf);
569 if (q->irqlock)
570 spin_unlock_irqrestore(q->irqlock,flags);
571 retval = videobuf_waiton(q->read_buf,0,0);
572 if (0 == retval) {
573 CALL(q,sync,q,q->read_buf);
574 if (STATE_ERROR == q->read_buf->state)
575 retval = -EIO;
576 else
577 retval = q->read_buf->size;
578 }
579
580 done:
581 /* cleanup */
582 q->ops->buf_release(q,q->read_buf);
583 kfree(q->read_buf);
584 q->read_buf = NULL;
585 return retval;
586}
587
588ssize_t videobuf_read_one(struct videobuf_queue *q,
589 char __user *data, size_t count, loff_t *ppos,
590 int nonblocking)
591{
592 enum v4l2_field field;
593 unsigned long flags=0;
594 unsigned size, nbufs;
595 int retval;
596
597 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
598
599 mutex_lock(&q->lock);
600
601 nbufs = 1; size = 0;
602 q->ops->buf_setup(q,&nbufs,&size);
603
604 if (NULL == q->read_buf &&
605 count >= size &&
606 !nonblocking) {
607 retval = videobuf_read_zerocopy(q,data,count,ppos);
608 if (retval >= 0 || retval == -EIO)
609 /* ok, all done */
610 goto done;
611 /* fallback to kernel bounce buffer on failures */
612 }
613
614 if (NULL == q->read_buf) {
615 /* need to capture a new frame */
616 retval = -ENOMEM;
617 q->read_buf = videobuf_alloc(q);
618
619 dprintk(1,"video alloc=0x%p\n", q->read_buf);
620 if (NULL == q->read_buf)
621 goto done;
622 q->read_buf->memory = V4L2_MEMORY_USERPTR;
623 q->read_buf->bsize = count; /* preferred size */
624 field = videobuf_next_field(q);
625 retval = q->ops->buf_prepare(q,q->read_buf,field);
626
627 if (0 != retval) {
628 kfree (q->read_buf);
629 q->read_buf = NULL;
630 goto done;
631 }
632 if (q->irqlock)
633 spin_lock_irqsave(q->irqlock,flags);
634
635 q->ops->buf_queue(q,q->read_buf);
636 if (q->irqlock)
637 spin_unlock_irqrestore(q->irqlock,flags);
638 q->read_off = 0;
639 }
640
641 /* wait until capture is done */
642 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
643 if (0 != retval)
644 goto done;
645
646 CALL(q,sync,q,q->read_buf);
647
648 if (STATE_ERROR == q->read_buf->state) {
649 /* catch I/O errors */
650 q->ops->buf_release(q,q->read_buf);
651 kfree(q->read_buf);
652 q->read_buf = NULL;
653 retval = -EIO;
654 goto done;
655 }
656
657 /* Copy to userspace */
658 retval=CALL(q,copy_to_user,q,data,count,nonblocking);
659 if (retval<0)
660 goto done;
661
662 q->read_off += retval;
663 if (q->read_off == q->read_buf->size) {
664 /* all data copied, cleanup */
665 q->ops->buf_release(q,q->read_buf);
666 kfree(q->read_buf);
667 q->read_buf = NULL;
668 }
669
670 done:
671 mutex_unlock(&q->lock);
672 return retval;
673}
674
675int videobuf_read_start(struct videobuf_queue *q)
676{
677 enum v4l2_field field;
678 unsigned long flags=0;
679 int count = 0, size = 0;
680 int err, i;
681
682 q->ops->buf_setup(q,&count,&size);
683 if (count < 2)
684 count = 2;
685 if (count > VIDEO_MAX_FRAME)
686 count = VIDEO_MAX_FRAME;
687 size = PAGE_ALIGN(size);
688
689 err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
690 if (err)
691 return err;
692
693 for (i = 0; i < count; i++) {
694 field = videobuf_next_field(q);
695 err = q->ops->buf_prepare(q,q->bufs[i],field);
696 if (err)
697 return err;
698 list_add_tail(&q->bufs[i]->stream, &q->stream);
699 }
700 if (q->irqlock)
701 spin_lock_irqsave(q->irqlock,flags);
702 for (i = 0; i < count; i++)
703 q->ops->buf_queue(q,q->bufs[i]);
704 if (q->irqlock)
705 spin_unlock_irqrestore(q->irqlock,flags);
706 q->reading = 1;
707 return 0;
708}
709
710void videobuf_read_stop(struct videobuf_queue *q)
711{
712 int i;
713
714 videobuf_queue_cancel(q);
715 videobuf_mmap_free(q);
716 INIT_LIST_HEAD(&q->stream);
717 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
718 if (NULL == q->bufs[i])
719 continue;
720 kfree(q->bufs[i]);
721 q->bufs[i] = NULL;
722 }
723 q->read_buf = NULL;
724 q->reading = 0;
725}
726
727ssize_t videobuf_read_stream(struct videobuf_queue *q,
728 char __user *data, size_t count, loff_t *ppos,
729 int vbihack, int nonblocking)
730{
731 int rc, retval;
732 unsigned long flags=0;
733
734 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
735
736 dprintk(2,"%s\n",__FUNCTION__);
737 mutex_lock(&q->lock);
738 retval = -EBUSY;
739 if (q->streaming)
740 goto done;
741 if (!q->reading) {
742 retval = videobuf_read_start(q);
743 if (retval < 0)
744 goto done;
745 }
746
747 retval = 0;
748 while (count > 0) {
749 /* get / wait for data */
750 if (NULL == q->read_buf) {
751 q->read_buf = list_entry(q->stream.next,
752 struct videobuf_buffer,
753 stream);
754 list_del(&q->read_buf->stream);
755 q->read_off = 0;
756 }
757 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
758 if (rc < 0) {
759 if (0 == retval)
760 retval = rc;
761 break;
762 }
763
764 if (q->read_buf->state == STATE_DONE) {
765 rc = CALL (q,copy_stream, q, data, count,
766 retval, vbihack, nonblocking);
767 if (rc < 0) {
768 retval = rc;
769 break;
770 }
771 retval += rc;
772 count -= rc;
773 q->read_off += rc;
774 } else {
775 /* some error */
776 q->read_off = q->read_buf->size;
777 if (0 == retval)
778 retval = -EIO;
779 }
780
781 /* requeue buffer when done with copying */
782 if (q->read_off == q->read_buf->size) {
783 list_add_tail(&q->read_buf->stream,
784 &q->stream);
785 if (q->irqlock)
786 spin_lock_irqsave(q->irqlock,flags);
787 q->ops->buf_queue(q,q->read_buf);
788 if (q->irqlock)
789 spin_unlock_irqrestore(q->irqlock,flags);
790 q->read_buf = NULL;
791 }
792 if (retval < 0)
793 break;
794 }
795
796 done:
797 mutex_unlock(&q->lock);
798 return retval;
799}
800
801unsigned int videobuf_poll_stream(struct file *file,
802 struct videobuf_queue *q,
803 poll_table *wait)
804{
805 struct videobuf_buffer *buf = NULL;
806 unsigned int rc = 0;
807
808 mutex_lock(&q->lock);
809 if (q->streaming) {
810 if (!list_empty(&q->stream))
811 buf = list_entry(q->stream.next,
812 struct videobuf_buffer, stream);
813 } else {
814 if (!q->reading)
815 videobuf_read_start(q);
816 if (!q->reading) {
817 rc = POLLERR;
818 } else if (NULL == q->read_buf) {
819 q->read_buf = list_entry(q->stream.next,
820 struct videobuf_buffer,
821 stream);
822 list_del(&q->read_buf->stream);
823 q->read_off = 0;
824 }
825 buf = q->read_buf;
826 }
827 if (!buf)
828 rc = POLLERR;
829
830 if (0 == rc) {
831 poll_wait(file, &buf->done, wait);
832 if (buf->state == STATE_DONE ||
833 buf->state == STATE_ERROR)
834 rc = POLLIN|POLLRDNORM;
835 }
836 mutex_unlock(&q->lock);
837 return rc;
838}
839
840int videobuf_mmap_setup(struct videobuf_queue *q,
841 unsigned int bcount, unsigned int bsize,
842 enum v4l2_memory memory)
843{
844 unsigned int i;
845 int err;
846
847 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
848
849 err = videobuf_mmap_free(q);
850 if (0 != err)
851 return err;
852
853 /* Allocate and initialize buffers */
854 for (i = 0; i < bcount; i++) {
855 q->bufs[i] = videobuf_alloc(q);
856
857 q->bufs[i]->i = i;
858 q->bufs[i]->input = UNSET;
859 q->bufs[i]->memory = memory;
860 q->bufs[i]->bsize = bsize;
861 switch (memory) {
862 case V4L2_MEMORY_MMAP:
863 q->bufs[i]->boff = bsize * i;
864 break;
865 case V4L2_MEMORY_USERPTR:
866 case V4L2_MEMORY_OVERLAY:
867 /* nothing */
868 break;
869 }
870 }
871
872 dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
873 bcount,bsize);
874
875 return 0;
876}
877
878int videobuf_mmap_free(struct videobuf_queue *q)
879{
880 int i;
881 int rc;
882
883 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
884
885 rc = CALL(q,mmap_free,q);
886 if (rc<0)
887 return rc;
888
889 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
890 if (NULL == q->bufs[i])
891 continue;
892 q->ops->buf_release(q,q->bufs[i]);
893 kfree(q->bufs[i]);
894 q->bufs[i] = NULL;
895 }
896
897 return rc;
898}
899
900int videobuf_mmap_mapper(struct videobuf_queue *q,
901 struct vm_area_struct *vma)
902{
903 int retval;
904
905 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
906
907 mutex_lock(&q->lock);
908 retval=CALL(q,mmap_mapper,q,vma);
909 mutex_unlock(&q->lock);
910
911 return retval;
912}
913
914#ifdef CONFIG_VIDEO_V4L1_COMPAT
915int videobuf_cgmbuf(struct videobuf_queue *q,
916 struct video_mbuf *mbuf, int count)
917{
918 struct v4l2_requestbuffers req;
919 int rc,i;
920
921 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
922
923 memset(&req,0,sizeof(req));
924 req.type = q->type;
925 req.count = count;
926 req.memory = V4L2_MEMORY_MMAP;
927 rc = videobuf_reqbufs(q,&req);
928 if (rc < 0)
929 return rc;
930
931 mbuf->frames = req.count;
932 mbuf->size = 0;
933 for (i = 0; i < mbuf->frames; i++) {
934 mbuf->offsets[i] = q->bufs[i]->boff;
935 mbuf->size += q->bufs[i]->bsize;
936 }
937
938 return 0;
939}
940#endif
941
942/* --------------------------------------------------------------------- */
943
944EXPORT_SYMBOL_GPL(videobuf_waiton);
945EXPORT_SYMBOL_GPL(videobuf_iolock);
946
947EXPORT_SYMBOL_GPL(videobuf_alloc);
948
949EXPORT_SYMBOL_GPL(videobuf_queue_init);
950EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
951EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
952
953EXPORT_SYMBOL_GPL(videobuf_next_field);
954EXPORT_SYMBOL_GPL(videobuf_reqbufs);
955EXPORT_SYMBOL_GPL(videobuf_querybuf);
956EXPORT_SYMBOL_GPL(videobuf_qbuf);
957EXPORT_SYMBOL_GPL(videobuf_dqbuf);
958EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
959EXPORT_SYMBOL_GPL(videobuf_streamon);
960EXPORT_SYMBOL_GPL(videobuf_streamoff);
961
962EXPORT_SYMBOL_GPL(videobuf_read_start);
963EXPORT_SYMBOL_GPL(videobuf_read_stop);
964EXPORT_SYMBOL_GPL(videobuf_read_stream);
965EXPORT_SYMBOL_GPL(videobuf_read_one);
966EXPORT_SYMBOL_GPL(videobuf_poll_stream);
967
968EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
969EXPORT_SYMBOL_GPL(videobuf_mmap_free);
970EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
971
972/*
973 * Local variables:
974 * c-basic-offset: 8
975 * End:
976 */
Linux 6.x block layer and io_uring tree(s)