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