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 }
339
340 b->flags = 0;
341 if (vb->map)
342 b->flags |= V4L2_BUF_FLAG_MAPPED;
343
344 switch (vb->state) {
345 case VIDEOBUF_PREPARED:
346 case VIDEOBUF_QUEUED:
347 case VIDEOBUF_ACTIVE:
348 b->flags |= V4L2_BUF_FLAG_QUEUED;
349 break;
350 case VIDEOBUF_ERROR:
351 b->flags |= V4L2_BUF_FLAG_ERROR;
352 /* fall through */
353 case VIDEOBUF_DONE:
354 b->flags |= V4L2_BUF_FLAG_DONE;
355 break;
356 case VIDEOBUF_NEEDS_INIT:
357 case VIDEOBUF_IDLE:
358 /* nothing */
359 break;
360 }
361
362 if (vb->input != UNSET) {
363 b->flags |= V4L2_BUF_FLAG_INPUT;
364 b->input = vb->input;
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
videobuf_mmap_free(struct videobuf_queue * q)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 */
__videobuf_mmap_setup(struct videobuf_queue * q,unsigned int bcount,unsigned int bsize,enum v4l2_memory memory)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]->input = UNSET;
406 q->bufs[i]->memory = memory;
407 q->bufs[i]->bsize = bsize;
408 switch (memory) {
409 case V4L2_MEMORY_MMAP:
410 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
411 break;
412 case V4L2_MEMORY_USERPTR:
413 case V4L2_MEMORY_OVERLAY:
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
videobuf_mmap_setup(struct videobuf_queue * q,unsigned int bcount,unsigned int bsize,enum v4l2_memory memory)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
videobuf_reqbufs(struct videobuf_queue * q,struct v4l2_requestbuffers * req)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->count < 1) {
447 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
448 return -EINVAL;
449 }
450
451 if (req->memory != V4L2_MEMORY_MMAP &&
452 req->memory != V4L2_MEMORY_USERPTR &&
453 req->memory != V4L2_MEMORY_OVERLAY) {
454 dprintk(1, "reqbufs: memory type invalid\n");
455 return -EINVAL;
456 }
457
458 videobuf_queue_lock(q);
459 if (req->type != q->type) {
460 dprintk(1, "reqbufs: queue type invalid\n");
461 retval = -EINVAL;
462 goto done;
463 }
464
465 if (q->streaming) {
466 dprintk(1, "reqbufs: streaming already exists\n");
467 retval = -EBUSY;
468 goto done;
469 }
470 if (!list_empty(&q->stream)) {
471 dprintk(1, "reqbufs: stream running\n");
472 retval = -EBUSY;
473 goto done;
474 }
475
476 count = req->count;
477 if (count > VIDEO_MAX_FRAME)
478 count = VIDEO_MAX_FRAME;
479 size = 0;
480 q->ops->buf_setup(q, &count, &size);
481 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
482 count, size,
483 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
484
485 retval = __videobuf_mmap_setup(q, count, size, req->memory);
486 if (retval < 0) {
487 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
488 goto done;
489 }
490
491 req->count = retval;
492 retval = 0;
493
494 done:
495 videobuf_queue_unlock(q);
496 return retval;
497 }
498 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
499
videobuf_querybuf(struct videobuf_queue * q,struct v4l2_buffer * b)500 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
501 {
502 int ret = -EINVAL;
503
504 videobuf_queue_lock(q);
505 if (unlikely(b->type != q->type)) {
506 dprintk(1, "querybuf: Wrong type.\n");
507 goto done;
508 }
509 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
510 dprintk(1, "querybuf: index out of range.\n");
511 goto done;
512 }
513 if (unlikely(NULL == q->bufs[b->index])) {
514 dprintk(1, "querybuf: buffer is null.\n");
515 goto done;
516 }
517
518 videobuf_status(q, b, q->bufs[b->index], q->type);
519
520 ret = 0;
521 done:
522 videobuf_queue_unlock(q);
523 return ret;
524 }
525 EXPORT_SYMBOL_GPL(videobuf_querybuf);
526
videobuf_qbuf(struct videobuf_queue * q,struct v4l2_buffer * b)527 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
528 {
529 struct videobuf_buffer *buf;
530 enum v4l2_field field;
531 unsigned long flags = 0;
532 int retval;
533
534 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
535
536 if (b->memory == V4L2_MEMORY_MMAP)
537 down_read(¤t->mm->mmap_sem);
538
539 videobuf_queue_lock(q);
540 retval = -EBUSY;
541 if (q->reading) {
542 dprintk(1, "qbuf: Reading running...\n");
543 goto done;
544 }
545 retval = -EINVAL;
546 if (b->type != q->type) {
547 dprintk(1, "qbuf: Wrong type.\n");
548 goto done;
549 }
550 if (b->index >= VIDEO_MAX_FRAME) {
551 dprintk(1, "qbuf: index out of range.\n");
552 goto done;
553 }
554 buf = q->bufs[b->index];
555 if (NULL == buf) {
556 dprintk(1, "qbuf: buffer is null.\n");
557 goto done;
558 }
559 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
560 if (buf->memory != b->memory) {
561 dprintk(1, "qbuf: memory type is wrong.\n");
562 goto done;
563 }
564 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
565 dprintk(1, "qbuf: buffer is already queued or active.\n");
566 goto done;
567 }
568
569 if (b->flags & V4L2_BUF_FLAG_INPUT) {
570 if (b->input >= q->inputs) {
571 dprintk(1, "qbuf: wrong input.\n");
572 goto done;
573 }
574 buf->input = b->input;
575 } else {
576 buf->input = UNSET;
577 }
578
579 switch (b->memory) {
580 case V4L2_MEMORY_MMAP:
581 if (0 == buf->baddr) {
582 dprintk(1, "qbuf: mmap requested "
583 "but buffer addr is zero!\n");
584 goto done;
585 }
586 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
587 || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
588 || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
589 buf->size = b->bytesused;
590 buf->field = b->field;
591 buf->ts = b->timestamp;
592 }
593 break;
594 case V4L2_MEMORY_USERPTR:
595 if (b->length < buf->bsize) {
596 dprintk(1, "qbuf: buffer length is not enough\n");
597 goto done;
598 }
599 if (VIDEOBUF_NEEDS_INIT != buf->state &&
600 buf->baddr != b->m.userptr)
601 q->ops->buf_release(q, buf);
602 buf->baddr = b->m.userptr;
603 break;
604 case V4L2_MEMORY_OVERLAY:
605 buf->boff = b->m.offset;
606 break;
607 default:
608 dprintk(1, "qbuf: wrong memory type\n");
609 goto done;
610 }
611
612 dprintk(1, "qbuf: requesting next field\n");
613 field = videobuf_next_field(q);
614 retval = q->ops->buf_prepare(q, buf, field);
615 if (0 != retval) {
616 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
617 goto done;
618 }
619
620 list_add_tail(&buf->stream, &q->stream);
621 if (q->streaming) {
622 spin_lock_irqsave(q->irqlock, flags);
623 q->ops->buf_queue(q, buf);
624 spin_unlock_irqrestore(q->irqlock, flags);
625 }
626 dprintk(1, "qbuf: succeeded\n");
627 retval = 0;
628 wake_up_interruptible_sync(&q->wait);
629
630 done:
631 videobuf_queue_unlock(q);
632
633 if (b->memory == V4L2_MEMORY_MMAP)
634 up_read(¤t->mm->mmap_sem);
635
636 return retval;
637 }
638 EXPORT_SYMBOL_GPL(videobuf_qbuf);
639
640 /* Locking: Caller holds q->vb_lock */
stream_next_buffer_check_queue(struct videobuf_queue * q,int noblock)641 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
642 {
643 int retval;
644
645 checks:
646 if (!q->streaming) {
647 dprintk(1, "next_buffer: Not streaming\n");
648 retval = -EINVAL;
649 goto done;
650 }
651
652 if (list_empty(&q->stream)) {
653 if (noblock) {
654 retval = -EAGAIN;
655 dprintk(2, "next_buffer: no buffers to dequeue\n");
656 goto done;
657 } else {
658 dprintk(2, "next_buffer: waiting on buffer\n");
659
660 /* Drop lock to avoid deadlock with qbuf */
661 videobuf_queue_unlock(q);
662
663 /* Checking list_empty and streaming is safe without
664 * locks because we goto checks to validate while
665 * holding locks before proceeding */
666 retval = wait_event_interruptible(q->wait,
667 !list_empty(&q->stream) || !q->streaming);
668 videobuf_queue_lock(q);
669
670 if (retval)
671 goto done;
672
673 goto checks;
674 }
675 }
676
677 retval = 0;
678
679 done:
680 return retval;
681 }
682
683 /* Locking: Caller holds q->vb_lock */
stream_next_buffer(struct videobuf_queue * q,struct videobuf_buffer ** vb,int nonblocking)684 static int stream_next_buffer(struct videobuf_queue *q,
685 struct videobuf_buffer **vb, int nonblocking)
686 {
687 int retval;
688 struct videobuf_buffer *buf = NULL;
689
690 retval = stream_next_buffer_check_queue(q, nonblocking);
691 if (retval)
692 goto done;
693
694 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
695 retval = videobuf_waiton(q, buf, nonblocking, 1);
696 if (retval < 0)
697 goto done;
698
699 *vb = buf;
700 done:
701 return retval;
702 }
703
videobuf_dqbuf(struct videobuf_queue * q,struct v4l2_buffer * b,int nonblocking)704 int videobuf_dqbuf(struct videobuf_queue *q,
705 struct v4l2_buffer *b, int nonblocking)
706 {
707 struct videobuf_buffer *buf = NULL;
708 int retval;
709
710 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
711
712 memset(b, 0, sizeof(*b));
713 videobuf_queue_lock(q);
714
715 retval = stream_next_buffer(q, &buf, nonblocking);
716 if (retval < 0) {
717 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
718 goto done;
719 }
720
721 switch (buf->state) {
722 case VIDEOBUF_ERROR:
723 dprintk(1, "dqbuf: state is error\n");
724 break;
725 case VIDEOBUF_DONE:
726 dprintk(1, "dqbuf: state is done\n");
727 break;
728 default:
729 dprintk(1, "dqbuf: state invalid\n");
730 retval = -EINVAL;
731 goto done;
732 }
733 CALL(q, sync, q, buf);
734 videobuf_status(q, b, buf, q->type);
735 list_del(&buf->stream);
736 buf->state = VIDEOBUF_IDLE;
737 b->flags &= ~V4L2_BUF_FLAG_DONE;
738 done:
739 videobuf_queue_unlock(q);
740 return retval;
741 }
742 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
743
videobuf_streamon(struct videobuf_queue * q)744 int videobuf_streamon(struct videobuf_queue *q)
745 {
746 struct videobuf_buffer *buf;
747 unsigned long flags = 0;
748 int retval;
749
750 videobuf_queue_lock(q);
751 retval = -EBUSY;
752 if (q->reading)
753 goto done;
754 retval = 0;
755 if (q->streaming)
756 goto done;
757 q->streaming = 1;
758 spin_lock_irqsave(q->irqlock, flags);
759 list_for_each_entry(buf, &q->stream, stream)
760 if (buf->state == VIDEOBUF_PREPARED)
761 q->ops->buf_queue(q, buf);
762 spin_unlock_irqrestore(q->irqlock, flags);
763
764 wake_up_interruptible_sync(&q->wait);
765 done:
766 videobuf_queue_unlock(q);
767 return retval;
768 }
769 EXPORT_SYMBOL_GPL(videobuf_streamon);
770
771 /* Locking: Caller holds q->vb_lock */
__videobuf_streamoff(struct videobuf_queue * q)772 static int __videobuf_streamoff(struct videobuf_queue *q)
773 {
774 if (!q->streaming)
775 return -EINVAL;
776
777 videobuf_queue_cancel(q);
778
779 return 0;
780 }
781
videobuf_streamoff(struct videobuf_queue * q)782 int videobuf_streamoff(struct videobuf_queue *q)
783 {
784 int retval;
785
786 videobuf_queue_lock(q);
787 retval = __videobuf_streamoff(q);
788 videobuf_queue_unlock(q);
789
790 return retval;
791 }
792 EXPORT_SYMBOL_GPL(videobuf_streamoff);
793
794 /* Locking: Caller holds q->vb_lock */
videobuf_read_zerocopy(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos)795 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
796 char __user *data,
797 size_t count, loff_t *ppos)
798 {
799 enum v4l2_field field;
800 unsigned long flags = 0;
801 int retval;
802
803 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
804
805 /* setup stuff */
806 q->read_buf = videobuf_alloc_vb(q);
807 if (NULL == q->read_buf)
808 return -ENOMEM;
809
810 q->read_buf->memory = V4L2_MEMORY_USERPTR;
811 q->read_buf->baddr = (unsigned long)data;
812 q->read_buf->bsize = count;
813
814 field = videobuf_next_field(q);
815 retval = q->ops->buf_prepare(q, q->read_buf, field);
816 if (0 != retval)
817 goto done;
818
819 /* start capture & wait */
820 spin_lock_irqsave(q->irqlock, flags);
821 q->ops->buf_queue(q, q->read_buf);
822 spin_unlock_irqrestore(q->irqlock, flags);
823 retval = videobuf_waiton(q, q->read_buf, 0, 0);
824 if (0 == retval) {
825 CALL(q, sync, q, q->read_buf);
826 if (VIDEOBUF_ERROR == q->read_buf->state)
827 retval = -EIO;
828 else
829 retval = q->read_buf->size;
830 }
831
832 done:
833 /* cleanup */
834 q->ops->buf_release(q, q->read_buf);
835 kfree(q->read_buf);
836 q->read_buf = NULL;
837 return retval;
838 }
839
__videobuf_copy_to_user(struct videobuf_queue * q,struct videobuf_buffer * buf,char __user * data,size_t count,int nonblocking)840 static int __videobuf_copy_to_user(struct videobuf_queue *q,
841 struct videobuf_buffer *buf,
842 char __user *data, size_t count,
843 int nonblocking)
844 {
845 void *vaddr = CALL(q, vaddr, buf);
846
847 /* copy to userspace */
848 if (count > buf->size - q->read_off)
849 count = buf->size - q->read_off;
850
851 if (copy_to_user(data, vaddr + q->read_off, count))
852 return -EFAULT;
853
854 return count;
855 }
856
__videobuf_copy_stream(struct videobuf_queue * q,struct videobuf_buffer * buf,char __user * data,size_t count,size_t pos,int vbihack,int nonblocking)857 static int __videobuf_copy_stream(struct videobuf_queue *q,
858 struct videobuf_buffer *buf,
859 char __user *data, size_t count, size_t pos,
860 int vbihack, int nonblocking)
861 {
862 unsigned int *fc = CALL(q, vaddr, buf);
863
864 if (vbihack) {
865 /* dirty, undocumented hack -- pass the frame counter
866 * within the last four bytes of each vbi data block.
867 * We need that one to maintain backward compatibility
868 * to all vbi decoding software out there ... */
869 fc += (buf->size >> 2) - 1;
870 *fc = buf->field_count >> 1;
871 dprintk(1, "vbihack: %d\n", *fc);
872 }
873
874 /* copy stuff using the common method */
875 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
876
877 if ((count == -EFAULT) && (pos == 0))
878 return -EFAULT;
879
880 return count;
881 }
882
videobuf_read_one(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos,int nonblocking)883 ssize_t videobuf_read_one(struct videobuf_queue *q,
884 char __user *data, size_t count, loff_t *ppos,
885 int nonblocking)
886 {
887 enum v4l2_field field;
888 unsigned long flags = 0;
889 unsigned size = 0, nbufs = 1;
890 int retval;
891
892 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
893
894 videobuf_queue_lock(q);
895
896 q->ops->buf_setup(q, &nbufs, &size);
897
898 if (NULL == q->read_buf &&
899 count >= size &&
900 !nonblocking) {
901 retval = videobuf_read_zerocopy(q, data, count, ppos);
902 if (retval >= 0 || retval == -EIO)
903 /* ok, all done */
904 goto done;
905 /* fallback to kernel bounce buffer on failures */
906 }
907
908 if (NULL == q->read_buf) {
909 /* need to capture a new frame */
910 retval = -ENOMEM;
911 q->read_buf = videobuf_alloc_vb(q);
912
913 dprintk(1, "video alloc=0x%p\n", q->read_buf);
914 if (NULL == q->read_buf)
915 goto done;
916 q->read_buf->memory = V4L2_MEMORY_USERPTR;
917 q->read_buf->bsize = count; /* preferred size */
918 field = videobuf_next_field(q);
919 retval = q->ops->buf_prepare(q, q->read_buf, field);
920
921 if (0 != retval) {
922 kfree(q->read_buf);
923 q->read_buf = NULL;
924 goto done;
925 }
926
927 spin_lock_irqsave(q->irqlock, flags);
928 q->ops->buf_queue(q, q->read_buf);
929 spin_unlock_irqrestore(q->irqlock, flags);
930
931 q->read_off = 0;
932 }
933
934 /* wait until capture is done */
935 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
936 if (0 != retval)
937 goto done;
938
939 CALL(q, sync, q, q->read_buf);
940
941 if (VIDEOBUF_ERROR == q->read_buf->state) {
942 /* catch I/O errors */
943 q->ops->buf_release(q, q->read_buf);
944 kfree(q->read_buf);
945 q->read_buf = NULL;
946 retval = -EIO;
947 goto done;
948 }
949
950 /* Copy to userspace */
951 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
952 if (retval < 0)
953 goto done;
954
955 q->read_off += retval;
956 if (q->read_off == q->read_buf->size) {
957 /* all data copied, cleanup */
958 q->ops->buf_release(q, q->read_buf);
959 kfree(q->read_buf);
960 q->read_buf = NULL;
961 }
962
963 done:
964 videobuf_queue_unlock(q);
965 return retval;
966 }
967 EXPORT_SYMBOL_GPL(videobuf_read_one);
968
969 /* Locking: Caller holds q->vb_lock */
__videobuf_read_start(struct videobuf_queue * q)970 static int __videobuf_read_start(struct videobuf_queue *q)
971 {
972 enum v4l2_field field;
973 unsigned long flags = 0;
974 unsigned int count = 0, size = 0;
975 int err, i;
976
977 q->ops->buf_setup(q, &count, &size);
978 if (count < 2)
979 count = 2;
980 if (count > VIDEO_MAX_FRAME)
981 count = VIDEO_MAX_FRAME;
982 size = PAGE_ALIGN(size);
983
984 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
985 if (err < 0)
986 return err;
987
988 count = err;
989
990 for (i = 0; i < count; i++) {
991 field = videobuf_next_field(q);
992 err = q->ops->buf_prepare(q, q->bufs[i], field);
993 if (err)
994 return err;
995 list_add_tail(&q->bufs[i]->stream, &q->stream);
996 }
997 spin_lock_irqsave(q->irqlock, flags);
998 for (i = 0; i < count; i++)
999 q->ops->buf_queue(q, q->bufs[i]);
1000 spin_unlock_irqrestore(q->irqlock, flags);
1001 q->reading = 1;
1002 return 0;
1003 }
1004
__videobuf_read_stop(struct videobuf_queue * q)1005 static void __videobuf_read_stop(struct videobuf_queue *q)
1006 {
1007 int i;
1008
1009 videobuf_queue_cancel(q);
1010 __videobuf_free(q);
1011 INIT_LIST_HEAD(&q->stream);
1012 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1013 if (NULL == q->bufs[i])
1014 continue;
1015 kfree(q->bufs[i]);
1016 q->bufs[i] = NULL;
1017 }
1018 q->read_buf = NULL;
1019 }
1020
videobuf_read_start(struct videobuf_queue * q)1021 int videobuf_read_start(struct videobuf_queue *q)
1022 {
1023 int rc;
1024
1025 videobuf_queue_lock(q);
1026 rc = __videobuf_read_start(q);
1027 videobuf_queue_unlock(q);
1028
1029 return rc;
1030 }
1031 EXPORT_SYMBOL_GPL(videobuf_read_start);
1032
videobuf_read_stop(struct videobuf_queue * q)1033 void videobuf_read_stop(struct videobuf_queue *q)
1034 {
1035 videobuf_queue_lock(q);
1036 __videobuf_read_stop(q);
1037 videobuf_queue_unlock(q);
1038 }
1039 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1040
videobuf_stop(struct videobuf_queue * q)1041 void videobuf_stop(struct videobuf_queue *q)
1042 {
1043 videobuf_queue_lock(q);
1044
1045 if (q->streaming)
1046 __videobuf_streamoff(q);
1047
1048 if (q->reading)
1049 __videobuf_read_stop(q);
1050
1051 videobuf_queue_unlock(q);
1052 }
1053 EXPORT_SYMBOL_GPL(videobuf_stop);
1054
videobuf_read_stream(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos,int vbihack,int nonblocking)1055 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1056 char __user *data, size_t count, loff_t *ppos,
1057 int vbihack, int nonblocking)
1058 {
1059 int rc, retval;
1060 unsigned long flags = 0;
1061
1062 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1063
1064 dprintk(2, "%s\n", __func__);
1065 videobuf_queue_lock(q);
1066 retval = -EBUSY;
1067 if (q->streaming)
1068 goto done;
1069 if (!q->reading) {
1070 retval = __videobuf_read_start(q);
1071 if (retval < 0)
1072 goto done;
1073 }
1074
1075 retval = 0;
1076 while (count > 0) {
1077 /* get / wait for data */
1078 if (NULL == q->read_buf) {
1079 q->read_buf = list_entry(q->stream.next,
1080 struct videobuf_buffer,
1081 stream);
1082 list_del(&q->read_buf->stream);
1083 q->read_off = 0;
1084 }
1085 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1086 if (rc < 0) {
1087 if (0 == retval)
1088 retval = rc;
1089 break;
1090 }
1091
1092 if (q->read_buf->state == VIDEOBUF_DONE) {
1093 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1094 retval, vbihack, nonblocking);
1095 if (rc < 0) {
1096 retval = rc;
1097 break;
1098 }
1099 retval += rc;
1100 count -= rc;
1101 q->read_off += rc;
1102 } else {
1103 /* some error */
1104 q->read_off = q->read_buf->size;
1105 if (0 == retval)
1106 retval = -EIO;
1107 }
1108
1109 /* requeue buffer when done with copying */
1110 if (q->read_off == q->read_buf->size) {
1111 list_add_tail(&q->read_buf->stream,
1112 &q->stream);
1113 spin_lock_irqsave(q->irqlock, flags);
1114 q->ops->buf_queue(q, q->read_buf);
1115 spin_unlock_irqrestore(q->irqlock, flags);
1116 q->read_buf = NULL;
1117 }
1118 if (retval < 0)
1119 break;
1120 }
1121
1122 done:
1123 videobuf_queue_unlock(q);
1124 return retval;
1125 }
1126 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1127
videobuf_poll_stream(struct file * file,struct videobuf_queue * q,poll_table * wait)1128 unsigned int videobuf_poll_stream(struct file *file,
1129 struct videobuf_queue *q,
1130 poll_table *wait)
1131 {
1132 struct videobuf_buffer *buf = NULL;
1133 unsigned int rc = 0;
1134
1135 videobuf_queue_lock(q);
1136 if (q->streaming) {
1137 if (!list_empty(&q->stream))
1138 buf = list_entry(q->stream.next,
1139 struct videobuf_buffer, stream);
1140 } else {
1141 if (!q->reading)
1142 __videobuf_read_start(q);
1143 if (!q->reading) {
1144 rc = POLLERR;
1145 } else if (NULL == q->read_buf) {
1146 q->read_buf = list_entry(q->stream.next,
1147 struct videobuf_buffer,
1148 stream);
1149 list_del(&q->read_buf->stream);
1150 q->read_off = 0;
1151 }
1152 buf = q->read_buf;
1153 }
1154 if (!buf)
1155 rc = POLLERR;
1156
1157 if (0 == rc) {
1158 poll_wait(file, &buf->done, wait);
1159 if (buf->state == VIDEOBUF_DONE ||
1160 buf->state == VIDEOBUF_ERROR) {
1161 switch (q->type) {
1162 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1163 case V4L2_BUF_TYPE_VBI_OUTPUT:
1164 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1165 rc = POLLOUT | POLLWRNORM;
1166 break;
1167 default:
1168 rc = POLLIN | POLLRDNORM;
1169 break;
1170 }
1171 }
1172 }
1173 videobuf_queue_unlock(q);
1174 return rc;
1175 }
1176 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1177
videobuf_mmap_mapper(struct videobuf_queue * q,struct vm_area_struct * vma)1178 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1179 {
1180 int rc = -EINVAL;
1181 int i;
1182
1183 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1184
1185 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1186 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1187 return -EINVAL;
1188 }
1189
1190 videobuf_queue_lock(q);
1191 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1192 struct videobuf_buffer *buf = q->bufs[i];
1193
1194 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1195 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1196 rc = CALL(q, mmap_mapper, q, buf, vma);
1197 break;
1198 }
1199 }
1200 videobuf_queue_unlock(q);
1201
1202 return rc;
1203 }
1204 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1205