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