2 * generic helper functions for handling video4linux capture buffers
4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
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
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
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
24 #include <media/videobuf-core.h>
26 #define MAGIC_BUFFER 0x20070728
27 #define MAGIC_CHECK(is, should) \
29 if (unlikely((is) != (should))) { \
31 "magic mismatch: %x (expected %x)\n", \
38 module_param(debug, int, 0644);
40 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
41 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
42 MODULE_LICENSE("GPL");
44 #define dprintk(level, fmt, arg...) \
47 printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
50 /* --------------------------------------------------------------------- */
52 #define CALL(q, f, arg...) \
53 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
55 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
57 struct videobuf_buffer *vb;
59 BUG_ON(q->msize < sizeof(*vb));
61 if (!q->int_ops || !q->int_ops->alloc_vb) {
62 printk(KERN_ERR "No specific ops defined!\n");
66 vb = q->int_ops->alloc_vb(q->msize);
68 init_waitqueue_head(&vb->done);
69 vb->magic = MAGIC_BUFFER;
74 EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
76 static int is_state_active_or_queued(struct videobuf_queue *q, struct videobuf_buffer *vb)
81 spin_lock_irqsave(q->irqlock, flags);
82 rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
83 spin_unlock_irqrestore(q->irqlock, flags);
87 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
88 int non_blocking, int intr)
93 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
96 if (is_state_active_or_queued(q, vb))
101 is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
103 /* Release vdev lock to prevent this wait from blocking outside access to
106 mutex_unlock(q->ext_lock);
108 ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb));
110 wait_event(vb->done, is_state_active_or_queued(q, vb));
113 mutex_lock(q->ext_lock);
117 EXPORT_SYMBOL_GPL(videobuf_waiton);
119 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
120 struct v4l2_framebuffer *fbuf)
122 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
123 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
125 return CALL(q, iolock, q, vb, fbuf);
127 EXPORT_SYMBOL_GPL(videobuf_iolock);
129 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
130 struct videobuf_buffer *buf)
132 if (q->int_ops->vaddr)
133 return q->int_ops->vaddr(buf);
136 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
138 /* --------------------------------------------------------------------- */
141 void videobuf_queue_core_init(struct videobuf_queue *q,
142 const struct videobuf_queue_ops *ops,
145 enum v4l2_buf_type type,
146 enum v4l2_field field,
149 struct videobuf_qtype_ops *int_ops,
150 struct mutex *ext_lock)
153 memset(q, 0, sizeof(*q));
154 q->irqlock = irqlock;
155 q->ext_lock = ext_lock;
162 q->int_ops = int_ops;
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);
170 /* Lock is mandatory for queue_cancel to work */
173 /* Having implementations for abstract methods are mandatory */
176 mutex_init(&q->vb_lock);
177 init_waitqueue_head(&q->wait);
178 INIT_LIST_HEAD(&q->stream);
180 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
182 /* Locking: Only usage in bttv unsafe find way to remove */
183 int videobuf_queue_is_busy(struct videobuf_queue *q)
187 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
190 dprintk(1, "busy: streaming active\n");
194 dprintk(1, "busy: pending read #1\n");
198 dprintk(1, "busy: pending read #2\n");
201 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
202 if (NULL == q->bufs[i])
204 if (q->bufs[i]->map) {
205 dprintk(1, "busy: buffer #%d mapped\n", i);
208 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
209 dprintk(1, "busy: buffer #%d queued\n", i);
212 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
213 dprintk(1, "busy: buffer #%d avtive\n", i);
219 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
222 * __videobuf_free() - free all the buffers and their control structures
224 * This function can only be called if streaming/reading is off, i.e. no buffers
225 * are under control of the driver.
227 /* Locking: Caller holds q->vb_lock */
228 static int __videobuf_free(struct videobuf_queue *q)
232 dprintk(1, "%s\n", __func__);
236 if (q->streaming || q->reading) {
237 dprintk(1, "Cannot free buffers when streaming or reading\n");
241 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
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");
249 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
250 if (NULL == q->bufs[i])
252 q->ops->buf_release(q, q->bufs[i]);
260 /* Locking: Caller holds q->vb_lock */
261 void videobuf_queue_cancel(struct videobuf_queue *q)
263 unsigned long flags = 0;
268 wake_up_interruptible_sync(&q->wait);
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])
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);
281 spin_unlock_irqrestore(q->irqlock, flags);
283 /* free all buffers + clear queue */
284 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
285 if (NULL == q->bufs[i])
287 q->ops->buf_release(q, q->bufs[i]);
289 INIT_LIST_HEAD(&q->stream);
291 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
293 /* --------------------------------------------------------------------- */
295 /* Locking: Caller holds q->vb_lock */
296 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
298 enum v4l2_field field = q->field;
300 BUG_ON(V4L2_FIELD_ANY == field);
302 if (V4L2_FIELD_ALTERNATE == field) {
303 if (V4L2_FIELD_TOP == q->last) {
304 field = V4L2_FIELD_BOTTOM;
305 q->last = V4L2_FIELD_BOTTOM;
307 field = V4L2_FIELD_TOP;
308 q->last = V4L2_FIELD_TOP;
313 EXPORT_SYMBOL_GPL(videobuf_next_field);
315 /* Locking: Caller holds q->vb_lock */
316 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
317 struct videobuf_buffer *vb, enum v4l2_buf_type type)
319 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
320 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
325 b->memory = vb->memory;
327 case V4L2_MEMORY_MMAP:
328 b->m.offset = vb->boff;
329 b->length = vb->bsize;
331 case V4L2_MEMORY_USERPTR:
332 b->m.userptr = vb->baddr;
333 b->length = vb->bsize;
335 case V4L2_MEMORY_OVERLAY:
336 b->m.offset = vb->boff;
342 b->flags |= V4L2_BUF_FLAG_MAPPED;
345 case VIDEOBUF_PREPARED:
346 case VIDEOBUF_QUEUED:
347 case VIDEOBUF_ACTIVE:
348 b->flags |= V4L2_BUF_FLAG_QUEUED;
351 b->flags |= V4L2_BUF_FLAG_ERROR;
354 b->flags |= V4L2_BUF_FLAG_DONE;
356 case VIDEOBUF_NEEDS_INIT:
362 if (vb->input != UNSET) {
363 b->flags |= V4L2_BUF_FLAG_INPUT;
364 b->input = vb->input;
367 b->field = vb->field;
368 b->timestamp = vb->ts;
369 b->bytesused = vb->size;
370 b->sequence = vb->field_count >> 1;
373 int videobuf_mmap_free(struct videobuf_queue *q)
376 videobuf_queue_lock(q);
377 ret = __videobuf_free(q);
378 videobuf_queue_unlock(q);
381 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
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)
391 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
393 err = __videobuf_free(q);
397 /* Allocate and initialize buffers */
398 for (i = 0; i < bcount; i++) {
399 q->bufs[i] = videobuf_alloc_vb(q);
401 if (NULL == q->bufs[i])
405 q->bufs[i]->input = UNSET;
406 q->bufs[i]->memory = memory;
407 q->bufs[i]->bsize = bsize;
409 case V4L2_MEMORY_MMAP:
410 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
412 case V4L2_MEMORY_USERPTR:
413 case V4L2_MEMORY_OVERLAY:
422 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
426 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
428 int videobuf_mmap_setup(struct videobuf_queue *q,
429 unsigned int bcount, unsigned int bsize,
430 enum v4l2_memory memory)
433 videobuf_queue_lock(q);
434 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
435 videobuf_queue_unlock(q);
438 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
440 int videobuf_reqbufs(struct videobuf_queue *q,
441 struct v4l2_requestbuffers *req)
443 unsigned int size, count;
446 if (req->count < 1) {
447 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
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");
458 videobuf_queue_lock(q);
459 if (req->type != q->type) {
460 dprintk(1, "reqbufs: queue type invalid\n");
466 dprintk(1, "reqbufs: streaming already exists\n");
470 if (!list_empty(&q->stream)) {
471 dprintk(1, "reqbufs: stream running\n");
477 if (count > VIDEO_MAX_FRAME)
478 count = VIDEO_MAX_FRAME;
480 q->ops->buf_setup(q, &count, &size);
481 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
483 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
485 retval = __videobuf_mmap_setup(q, count, size, req->memory);
487 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
495 videobuf_queue_unlock(q);
498 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
500 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
504 videobuf_queue_lock(q);
505 if (unlikely(b->type != q->type)) {
506 dprintk(1, "querybuf: Wrong type.\n");
509 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
510 dprintk(1, "querybuf: index out of range.\n");
513 if (unlikely(NULL == q->bufs[b->index])) {
514 dprintk(1, "querybuf: buffer is null.\n");
518 videobuf_status(q, b, q->bufs[b->index], q->type);
522 videobuf_queue_unlock(q);
525 EXPORT_SYMBOL_GPL(videobuf_querybuf);
527 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
529 struct videobuf_buffer *buf;
530 enum v4l2_field field;
531 unsigned long flags = 0;
534 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
536 if (b->memory == V4L2_MEMORY_MMAP)
537 down_read(¤t->mm->mmap_sem);
539 videobuf_queue_lock(q);
542 dprintk(1, "qbuf: Reading running...\n");
546 if (b->type != q->type) {
547 dprintk(1, "qbuf: Wrong type.\n");
550 if (b->index >= VIDEO_MAX_FRAME) {
551 dprintk(1, "qbuf: index out of range.\n");
554 buf = q->bufs[b->index];
556 dprintk(1, "qbuf: buffer is null.\n");
559 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
560 if (buf->memory != b->memory) {
561 dprintk(1, "qbuf: memory type is wrong.\n");
564 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
565 dprintk(1, "qbuf: buffer is already queued or active.\n");
569 if (b->flags & V4L2_BUF_FLAG_INPUT) {
570 if (b->input >= q->inputs) {
571 dprintk(1, "qbuf: wrong input.\n");
574 buf->input = b->input;
580 case V4L2_MEMORY_MMAP:
581 if (0 == buf->baddr) {
582 dprintk(1, "qbuf: mmap requested "
583 "but buffer addr is zero!\n");
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;
594 case V4L2_MEMORY_USERPTR:
595 if (b->length < buf->bsize) {
596 dprintk(1, "qbuf: buffer length is not enough\n");
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;
604 case V4L2_MEMORY_OVERLAY:
605 buf->boff = b->m.offset;
608 dprintk(1, "qbuf: wrong memory type\n");
612 dprintk(1, "qbuf: requesting next field\n");
613 field = videobuf_next_field(q);
614 retval = q->ops->buf_prepare(q, buf, field);
616 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
620 list_add_tail(&buf->stream, &q->stream);
622 spin_lock_irqsave(q->irqlock, flags);
623 q->ops->buf_queue(q, buf);
624 spin_unlock_irqrestore(q->irqlock, flags);
626 dprintk(1, "qbuf: succeeded\n");
628 wake_up_interruptible_sync(&q->wait);
631 videobuf_queue_unlock(q);
633 if (b->memory == V4L2_MEMORY_MMAP)
634 up_read(¤t->mm->mmap_sem);
638 EXPORT_SYMBOL_GPL(videobuf_qbuf);
640 /* Locking: Caller holds q->vb_lock */
641 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
647 dprintk(1, "next_buffer: Not streaming\n");
652 if (list_empty(&q->stream)) {
655 dprintk(2, "next_buffer: no buffers to dequeue\n");
658 dprintk(2, "next_buffer: waiting on buffer\n");
660 /* Drop lock to avoid deadlock with qbuf */
661 videobuf_queue_unlock(q);
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);
683 /* Locking: Caller holds q->vb_lock */
684 static int stream_next_buffer(struct videobuf_queue *q,
685 struct videobuf_buffer **vb, int nonblocking)
688 struct videobuf_buffer *buf = NULL;
690 retval = stream_next_buffer_check_queue(q, nonblocking);
694 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
695 retval = videobuf_waiton(q, buf, nonblocking, 1);
704 int videobuf_dqbuf(struct videobuf_queue *q,
705 struct v4l2_buffer *b, int nonblocking)
707 struct videobuf_buffer *buf = NULL;
710 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
712 memset(b, 0, sizeof(*b));
713 videobuf_queue_lock(q);
715 retval = stream_next_buffer(q, &buf, nonblocking);
717 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
721 switch (buf->state) {
723 dprintk(1, "dqbuf: state is error\n");
726 dprintk(1, "dqbuf: state is done\n");
729 dprintk(1, "dqbuf: state invalid\n");
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;
739 videobuf_queue_unlock(q);
742 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
744 int videobuf_streamon(struct videobuf_queue *q)
746 struct videobuf_buffer *buf;
747 unsigned long flags = 0;
750 videobuf_queue_lock(q);
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);
764 wake_up_interruptible_sync(&q->wait);
766 videobuf_queue_unlock(q);
769 EXPORT_SYMBOL_GPL(videobuf_streamon);
771 /* Locking: Caller holds q->vb_lock */
772 static int __videobuf_streamoff(struct videobuf_queue *q)
777 videobuf_queue_cancel(q);
782 int videobuf_streamoff(struct videobuf_queue *q)
786 videobuf_queue_lock(q);
787 retval = __videobuf_streamoff(q);
788 videobuf_queue_unlock(q);
792 EXPORT_SYMBOL_GPL(videobuf_streamoff);
794 /* Locking: Caller holds q->vb_lock */
795 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
797 size_t count, loff_t *ppos)
799 enum v4l2_field field;
800 unsigned long flags = 0;
803 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
806 q->read_buf = videobuf_alloc_vb(q);
807 if (NULL == q->read_buf)
810 q->read_buf->memory = V4L2_MEMORY_USERPTR;
811 q->read_buf->baddr = (unsigned long)data;
812 q->read_buf->bsize = count;
814 field = videobuf_next_field(q);
815 retval = q->ops->buf_prepare(q, q->read_buf, field);
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);
825 CALL(q, sync, q, q->read_buf);
826 if (VIDEOBUF_ERROR == q->read_buf->state)
829 retval = q->read_buf->size;
834 q->ops->buf_release(q, q->read_buf);
840 static int __videobuf_copy_to_user(struct videobuf_queue *q,
841 struct videobuf_buffer *buf,
842 char __user *data, size_t count,
845 void *vaddr = CALL(q, vaddr, buf);
847 /* copy to userspace */
848 if (count > buf->size - q->read_off)
849 count = buf->size - q->read_off;
851 if (copy_to_user(data, vaddr + q->read_off, count))
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)
862 unsigned int *fc = CALL(q, vaddr, buf);
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);
874 /* copy stuff using the common method */
875 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
877 if ((count == -EFAULT) && (pos == 0))
883 ssize_t videobuf_read_one(struct videobuf_queue *q,
884 char __user *data, size_t count, loff_t *ppos,
887 enum v4l2_field field;
888 unsigned long flags = 0;
889 unsigned size = 0, nbufs = 1;
892 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
894 videobuf_queue_lock(q);
896 q->ops->buf_setup(q, &nbufs, &size);
898 if (NULL == q->read_buf &&
901 retval = videobuf_read_zerocopy(q, data, count, ppos);
902 if (retval >= 0 || retval == -EIO)
905 /* fallback to kernel bounce buffer on failures */
908 if (NULL == q->read_buf) {
909 /* need to capture a new frame */
911 q->read_buf = videobuf_alloc_vb(q);
913 dprintk(1, "video alloc=0x%p\n", q->read_buf);
914 if (NULL == q->read_buf)
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);
927 spin_lock_irqsave(q->irqlock, flags);
928 q->ops->buf_queue(q, q->read_buf);
929 spin_unlock_irqrestore(q->irqlock, flags);
934 /* wait until capture is done */
935 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
939 CALL(q, sync, q, q->read_buf);
941 if (VIDEOBUF_ERROR == q->read_buf->state) {
942 /* catch I/O errors */
943 q->ops->buf_release(q, q->read_buf);
950 /* Copy to userspace */
951 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
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);
964 videobuf_queue_unlock(q);
967 EXPORT_SYMBOL_GPL(videobuf_read_one);
969 /* Locking: Caller holds q->vb_lock */
970 static int __videobuf_read_start(struct videobuf_queue *q)
972 enum v4l2_field field;
973 unsigned long flags = 0;
974 unsigned int count = 0, size = 0;
977 q->ops->buf_setup(q, &count, &size);
980 if (count > VIDEO_MAX_FRAME)
981 count = VIDEO_MAX_FRAME;
982 size = PAGE_ALIGN(size);
984 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
990 for (i = 0; i < count; i++) {
991 field = videobuf_next_field(q);
992 err = q->ops->buf_prepare(q, q->bufs[i], field);
995 list_add_tail(&q->bufs[i]->stream, &q->stream);
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);
1005 static void __videobuf_read_stop(struct videobuf_queue *q)
1009 videobuf_queue_cancel(q);
1011 INIT_LIST_HEAD(&q->stream);
1012 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1013 if (NULL == q->bufs[i])
1021 int videobuf_read_start(struct videobuf_queue *q)
1025 videobuf_queue_lock(q);
1026 rc = __videobuf_read_start(q);
1027 videobuf_queue_unlock(q);
1031 EXPORT_SYMBOL_GPL(videobuf_read_start);
1033 void videobuf_read_stop(struct videobuf_queue *q)
1035 videobuf_queue_lock(q);
1036 __videobuf_read_stop(q);
1037 videobuf_queue_unlock(q);
1039 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1041 void videobuf_stop(struct videobuf_queue *q)
1043 videobuf_queue_lock(q);
1046 __videobuf_streamoff(q);
1049 __videobuf_read_stop(q);
1051 videobuf_queue_unlock(q);
1053 EXPORT_SYMBOL_GPL(videobuf_stop);
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)
1060 unsigned long flags = 0;
1062 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1064 dprintk(2, "%s\n", __func__);
1065 videobuf_queue_lock(q);
1070 retval = __videobuf_read_start(q);
1077 /* get / wait for data */
1078 if (NULL == q->read_buf) {
1079 q->read_buf = list_entry(q->stream.next,
1080 struct videobuf_buffer,
1082 list_del(&q->read_buf->stream);
1085 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1092 if (q->read_buf->state == VIDEOBUF_DONE) {
1093 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1094 retval, vbihack, nonblocking);
1104 q->read_off = q->read_buf->size;
1109 /* requeue buffer when done with copying */
1110 if (q->read_off == q->read_buf->size) {
1111 list_add_tail(&q->read_buf->stream,
1113 spin_lock_irqsave(q->irqlock, flags);
1114 q->ops->buf_queue(q, q->read_buf);
1115 spin_unlock_irqrestore(q->irqlock, flags);
1123 videobuf_queue_unlock(q);
1126 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1128 unsigned int videobuf_poll_stream(struct file *file,
1129 struct videobuf_queue *q,
1132 struct videobuf_buffer *buf = NULL;
1133 unsigned int rc = 0;
1135 videobuf_queue_lock(q);
1137 if (!list_empty(&q->stream))
1138 buf = list_entry(q->stream.next,
1139 struct videobuf_buffer, stream);
1142 __videobuf_read_start(q);
1145 } else if (NULL == q->read_buf) {
1146 q->read_buf = list_entry(q->stream.next,
1147 struct videobuf_buffer,
1149 list_del(&q->read_buf->stream);
1158 poll_wait(file, &buf->done, wait);
1159 if (buf->state == VIDEOBUF_DONE ||
1160 buf->state == VIDEOBUF_ERROR) {
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;
1168 rc = POLLIN | POLLRDNORM;
1173 videobuf_queue_unlock(q);
1176 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1178 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1183 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
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");
1190 videobuf_queue_lock(q);
1191 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1192 struct videobuf_buffer *buf = q->bufs[i];
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);
1200 videobuf_queue_unlock(q);
1204 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1206 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1207 int videobuf_cgmbuf(struct videobuf_queue *q,
1208 struct video_mbuf *mbuf, int count)
1210 struct v4l2_requestbuffers req;
1213 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1215 memset(&req, 0, sizeof(req));
1218 req.memory = V4L2_MEMORY_MMAP;
1219 rc = videobuf_reqbufs(q, &req);
1223 mbuf->frames = req.count;
1225 for (i = 0; i < mbuf->frames; i++) {
1226 mbuf->offsets[i] = q->bufs[i]->boff;
1227 mbuf->size += PAGE_ALIGN(q->bufs[i]->bsize);
1232 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);