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;
338 case V4L2_MEMORY_DMABUF:
339 /* DMABUF is not handled in videobuf framework */
343 b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
345 b->flags |= V4L2_BUF_FLAG_MAPPED;
348 case VIDEOBUF_PREPARED:
349 case VIDEOBUF_QUEUED:
350 case VIDEOBUF_ACTIVE:
351 b->flags |= V4L2_BUF_FLAG_QUEUED;
354 b->flags |= V4L2_BUF_FLAG_ERROR;
357 b->flags |= V4L2_BUF_FLAG_DONE;
359 case VIDEOBUF_NEEDS_INIT:
365 b->field = vb->field;
366 b->timestamp = vb->ts;
367 b->bytesused = vb->size;
368 b->sequence = vb->field_count >> 1;
371 int videobuf_mmap_free(struct videobuf_queue *q)
374 videobuf_queue_lock(q);
375 ret = __videobuf_free(q);
376 videobuf_queue_unlock(q);
379 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
381 /* Locking: Caller holds q->vb_lock */
382 int __videobuf_mmap_setup(struct videobuf_queue *q,
383 unsigned int bcount, unsigned int bsize,
384 enum v4l2_memory memory)
389 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
391 err = __videobuf_free(q);
395 /* Allocate and initialize buffers */
396 for (i = 0; i < bcount; i++) {
397 q->bufs[i] = videobuf_alloc_vb(q);
399 if (NULL == q->bufs[i])
403 q->bufs[i]->memory = memory;
404 q->bufs[i]->bsize = bsize;
406 case V4L2_MEMORY_MMAP:
407 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
409 case V4L2_MEMORY_USERPTR:
410 case V4L2_MEMORY_OVERLAY:
411 case V4L2_MEMORY_DMABUF:
420 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
424 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
426 int videobuf_mmap_setup(struct videobuf_queue *q,
427 unsigned int bcount, unsigned int bsize,
428 enum v4l2_memory memory)
431 videobuf_queue_lock(q);
432 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
433 videobuf_queue_unlock(q);
436 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
438 int videobuf_reqbufs(struct videobuf_queue *q,
439 struct v4l2_requestbuffers *req)
441 unsigned int size, count;
444 if (req->count < 1) {
445 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
449 if (req->memory != V4L2_MEMORY_MMAP &&
450 req->memory != V4L2_MEMORY_USERPTR &&
451 req->memory != V4L2_MEMORY_OVERLAY) {
452 dprintk(1, "reqbufs: memory type invalid\n");
456 videobuf_queue_lock(q);
457 if (req->type != q->type) {
458 dprintk(1, "reqbufs: queue type invalid\n");
464 dprintk(1, "reqbufs: streaming already exists\n");
468 if (!list_empty(&q->stream)) {
469 dprintk(1, "reqbufs: stream running\n");
475 if (count > VIDEO_MAX_FRAME)
476 count = VIDEO_MAX_FRAME;
478 q->ops->buf_setup(q, &count, &size);
479 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
481 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
483 retval = __videobuf_mmap_setup(q, count, size, req->memory);
485 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
493 videobuf_queue_unlock(q);
496 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
498 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
502 videobuf_queue_lock(q);
503 if (unlikely(b->type != q->type)) {
504 dprintk(1, "querybuf: Wrong type.\n");
507 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
508 dprintk(1, "querybuf: index out of range.\n");
511 if (unlikely(NULL == q->bufs[b->index])) {
512 dprintk(1, "querybuf: buffer is null.\n");
516 videobuf_status(q, b, q->bufs[b->index], q->type);
520 videobuf_queue_unlock(q);
523 EXPORT_SYMBOL_GPL(videobuf_querybuf);
525 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
527 struct videobuf_buffer *buf;
528 enum v4l2_field field;
529 unsigned long flags = 0;
532 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
533 if (b->memory == V4L2_MEMORY_MMAP)
534 down_read(¤t->mm->mmap_sem);
535 videobuf_queue_lock(q);
538 dprintk(1, "qbuf: Reading running...\n");
542 if (b->type != q->type) {
543 dprintk(1, "qbuf: Wrong type.\n");
546 if (b->index >= VIDEO_MAX_FRAME) {
547 dprintk(1, "qbuf: index out of range.\n");
550 buf = q->bufs[b->index];
552 dprintk(1, "qbuf: buffer is null.\n");
555 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
556 if (buf->memory != b->memory) {
557 dprintk(1, "qbuf: memory type is wrong.\n");
560 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
561 dprintk(1, "qbuf: buffer is already queued or active.\n");
566 case V4L2_MEMORY_MMAP:
567 if (0 == buf->baddr) {
568 dprintk(1, "qbuf: mmap requested "
569 "but buffer addr is zero!\n");
572 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
573 || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
574 || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
575 buf->size = b->bytesused;
576 buf->field = b->field;
577 buf->ts = b->timestamp;
580 case V4L2_MEMORY_USERPTR:
581 if (b->length < buf->bsize) {
582 dprintk(1, "qbuf: buffer length is not enough\n");
585 if (VIDEOBUF_NEEDS_INIT != buf->state &&
586 buf->baddr != b->m.userptr)
587 q->ops->buf_release(q, buf);
588 buf->baddr = b->m.userptr;
590 case V4L2_MEMORY_OVERLAY:
591 buf->boff = b->m.offset;
594 dprintk(1, "qbuf: wrong memory type\n");
598 dprintk(1, "qbuf: requesting next field\n");
599 field = videobuf_next_field(q);
601 retval = q->ops->buf_prepare(q, buf, field);
603 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
606 list_add_tail(&buf->stream, &q->stream);
608 spin_lock_irqsave(q->irqlock, flags);
609 q->ops->buf_queue(q, buf);
610 spin_unlock_irqrestore(q->irqlock, flags);
612 dprintk(1, "qbuf: succeeded\n");
614 wake_up_interruptible_sync(&q->wait);
617 videobuf_queue_unlock(q);
618 if (b->memory == V4L2_MEMORY_MMAP)
619 up_read(¤t->mm->mmap_sem);
622 EXPORT_SYMBOL_GPL(videobuf_qbuf);
624 /* Locking: Caller holds q->vb_lock */
625 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
632 dprintk(1, "next_buffer: Not streaming\n");
637 if (list_empty(&q->stream)) {
640 dprintk(2, "next_buffer: no buffers to dequeue\n");
643 dprintk(2, "next_buffer: waiting on buffer\n");
645 /* Drop lock to avoid deadlock with qbuf */
646 videobuf_queue_unlock(q);
647 /*ddl@rock-chips.com */
648 is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
650 /* Release vdev lock to prevent this wait from blocking outside access to
653 mutex_unlock(q->ext_lock);
656 /* Checking list_empty and streaming is safe without
657 * locks because we goto checks to validate while
658 * holding locks before proceeding */
659 retval = wait_event_interruptible(q->wait,
660 !list_empty(&q->stream) || !q->streaming);
662 videobuf_queue_lock(q);
663 /*ddl@rock-chips.com */
665 mutex_lock(q->ext_lock);
679 /* Locking: Caller holds q->vb_lock */
680 static int stream_next_buffer(struct videobuf_queue *q,
681 struct videobuf_buffer **vb, int nonblocking)
684 struct videobuf_buffer *buf = NULL;
686 retval = stream_next_buffer_check_queue(q, nonblocking);
690 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
691 retval = videobuf_waiton(q, buf, nonblocking, 1);
700 int videobuf_dqbuf(struct videobuf_queue *q,
701 struct v4l2_buffer *b, int nonblocking)
703 struct videobuf_buffer *buf = NULL;
706 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
708 memset(b, 0, sizeof(*b));
709 videobuf_queue_lock(q);
711 retval = stream_next_buffer(q, &buf, nonblocking);
713 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
717 switch (buf->state) {
719 dprintk(1, "dqbuf: state is error\n");
722 dprintk(1, "dqbuf: state is done\n");
725 dprintk(1, "dqbuf: state invalid\n");
729 CALL(q, sync, q, buf);
730 videobuf_status(q, b, buf, q->type);
731 list_del(&buf->stream);
732 buf->state = VIDEOBUF_IDLE;
733 b->flags &= ~V4L2_BUF_FLAG_DONE;
735 videobuf_queue_unlock(q);
738 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
740 int videobuf_streamon(struct videobuf_queue *q)
742 struct videobuf_buffer *buf;
743 unsigned long flags = 0;
746 videobuf_queue_lock(q);
754 spin_lock_irqsave(q->irqlock, flags);
755 list_for_each_entry(buf, &q->stream, stream)
756 if (buf->state == VIDEOBUF_PREPARED)
757 q->ops->buf_queue(q, buf);
758 spin_unlock_irqrestore(q->irqlock, flags);
760 wake_up_interruptible_sync(&q->wait);
762 videobuf_queue_unlock(q);
765 EXPORT_SYMBOL_GPL(videobuf_streamon);
767 /* Locking: Caller holds q->vb_lock */
768 static int __videobuf_streamoff(struct videobuf_queue *q)
773 videobuf_queue_cancel(q);
778 int videobuf_streamoff(struct videobuf_queue *q)
782 videobuf_queue_lock(q);
783 retval = __videobuf_streamoff(q);
784 videobuf_queue_unlock(q);
788 EXPORT_SYMBOL_GPL(videobuf_streamoff);
790 /* Locking: Caller holds q->vb_lock */
791 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
793 size_t count, loff_t *ppos)
795 enum v4l2_field field;
796 unsigned long flags = 0;
799 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
802 q->read_buf = videobuf_alloc_vb(q);
803 if (NULL == q->read_buf)
806 q->read_buf->memory = V4L2_MEMORY_USERPTR;
807 q->read_buf->baddr = (unsigned long)data;
808 q->read_buf->bsize = count;
810 field = videobuf_next_field(q);
811 retval = q->ops->buf_prepare(q, q->read_buf, field);
815 /* start capture & wait */
816 spin_lock_irqsave(q->irqlock, flags);
817 q->ops->buf_queue(q, q->read_buf);
818 spin_unlock_irqrestore(q->irqlock, flags);
819 retval = videobuf_waiton(q, q->read_buf, 0, 0);
821 CALL(q, sync, q, q->read_buf);
822 if (VIDEOBUF_ERROR == q->read_buf->state)
825 retval = q->read_buf->size;
830 q->ops->buf_release(q, q->read_buf);
836 static int __videobuf_copy_to_user(struct videobuf_queue *q,
837 struct videobuf_buffer *buf,
838 char __user *data, size_t count,
841 void *vaddr = CALL(q, vaddr, buf);
843 /* copy to userspace */
844 if (count > buf->size - q->read_off)
845 count = buf->size - q->read_off;
847 if (copy_to_user(data, vaddr + q->read_off, count))
853 static int __videobuf_copy_stream(struct videobuf_queue *q,
854 struct videobuf_buffer *buf,
855 char __user *data, size_t count, size_t pos,
856 int vbihack, int nonblocking)
858 unsigned int *fc = CALL(q, vaddr, buf);
861 /* dirty, undocumented hack -- pass the frame counter
862 * within the last four bytes of each vbi data block.
863 * We need that one to maintain backward compatibility
864 * to all vbi decoding software out there ... */
865 fc += (buf->size >> 2) - 1;
866 *fc = buf->field_count >> 1;
867 dprintk(1, "vbihack: %d\n", *fc);
870 /* copy stuff using the common method */
871 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
873 if ((count == -EFAULT) && (pos == 0))
879 ssize_t videobuf_read_one(struct videobuf_queue *q,
880 char __user *data, size_t count, loff_t *ppos,
883 enum v4l2_field field;
884 unsigned long flags = 0;
885 unsigned size = 0, nbufs = 1;
888 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
890 videobuf_queue_lock(q);
892 q->ops->buf_setup(q, &nbufs, &size);
894 if (NULL == q->read_buf &&
897 retval = videobuf_read_zerocopy(q, data, count, ppos);
898 if (retval >= 0 || retval == -EIO)
901 /* fallback to kernel bounce buffer on failures */
904 if (NULL == q->read_buf) {
905 /* need to capture a new frame */
907 q->read_buf = videobuf_alloc_vb(q);
909 dprintk(1, "video alloc=0x%p\n", q->read_buf);
910 if (NULL == q->read_buf)
912 q->read_buf->memory = V4L2_MEMORY_USERPTR;
913 q->read_buf->bsize = count; /* preferred size */
914 field = videobuf_next_field(q);
915 retval = q->ops->buf_prepare(q, q->read_buf, field);
923 spin_lock_irqsave(q->irqlock, flags);
924 q->ops->buf_queue(q, q->read_buf);
925 spin_unlock_irqrestore(q->irqlock, flags);
930 /* wait until capture is done */
931 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
935 CALL(q, sync, q, q->read_buf);
937 if (VIDEOBUF_ERROR == q->read_buf->state) {
938 /* catch I/O errors */
939 q->ops->buf_release(q, q->read_buf);
946 /* Copy to userspace */
947 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
951 q->read_off += retval;
952 if (q->read_off == q->read_buf->size) {
953 /* all data copied, cleanup */
954 q->ops->buf_release(q, q->read_buf);
960 videobuf_queue_unlock(q);
963 EXPORT_SYMBOL_GPL(videobuf_read_one);
965 /* Locking: Caller holds q->vb_lock */
966 static int __videobuf_read_start(struct videobuf_queue *q)
968 enum v4l2_field field;
969 unsigned long flags = 0;
970 unsigned int count = 0, size = 0;
973 q->ops->buf_setup(q, &count, &size);
976 if (count > VIDEO_MAX_FRAME)
977 count = VIDEO_MAX_FRAME;
978 size = PAGE_ALIGN(size);
980 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
986 for (i = 0; i < count; i++) {
987 field = videobuf_next_field(q);
988 err = q->ops->buf_prepare(q, q->bufs[i], field);
991 list_add_tail(&q->bufs[i]->stream, &q->stream);
993 spin_lock_irqsave(q->irqlock, flags);
994 for (i = 0; i < count; i++)
995 q->ops->buf_queue(q, q->bufs[i]);
996 spin_unlock_irqrestore(q->irqlock, flags);
1001 static void __videobuf_read_stop(struct videobuf_queue *q)
1005 videobuf_queue_cancel(q);
1007 INIT_LIST_HEAD(&q->stream);
1008 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1009 if (NULL == q->bufs[i])
1017 int videobuf_read_start(struct videobuf_queue *q)
1021 videobuf_queue_lock(q);
1022 rc = __videobuf_read_start(q);
1023 videobuf_queue_unlock(q);
1027 EXPORT_SYMBOL_GPL(videobuf_read_start);
1029 void videobuf_read_stop(struct videobuf_queue *q)
1031 videobuf_queue_lock(q);
1032 __videobuf_read_stop(q);
1033 videobuf_queue_unlock(q);
1035 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1037 void videobuf_stop(struct videobuf_queue *q)
1039 videobuf_queue_lock(q);
1042 __videobuf_streamoff(q);
1045 __videobuf_read_stop(q);
1047 videobuf_queue_unlock(q);
1049 EXPORT_SYMBOL_GPL(videobuf_stop);
1051 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1052 char __user *data, size_t count, loff_t *ppos,
1053 int vbihack, int nonblocking)
1056 unsigned long flags = 0;
1058 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1060 dprintk(2, "%s\n", __func__);
1061 videobuf_queue_lock(q);
1066 retval = __videobuf_read_start(q);
1073 /* get / wait for data */
1074 if (NULL == q->read_buf) {
1075 q->read_buf = list_entry(q->stream.next,
1076 struct videobuf_buffer,
1078 list_del(&q->read_buf->stream);
1081 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1088 if (q->read_buf->state == VIDEOBUF_DONE) {
1089 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1090 retval, vbihack, nonblocking);
1100 q->read_off = q->read_buf->size;
1105 /* requeue buffer when done with copying */
1106 if (q->read_off == q->read_buf->size) {
1107 list_add_tail(&q->read_buf->stream,
1109 spin_lock_irqsave(q->irqlock, flags);
1110 q->ops->buf_queue(q, q->read_buf);
1111 spin_unlock_irqrestore(q->irqlock, flags);
1119 videobuf_queue_unlock(q);
1122 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1124 unsigned int videobuf_poll_stream(struct file *file,
1125 struct videobuf_queue *q,
1128 unsigned long req_events = poll_requested_events(wait);
1129 struct videobuf_buffer *buf = NULL;
1130 unsigned int rc = 0;
1132 videobuf_queue_lock(q);
1134 if (!list_empty(&q->stream))
1135 buf = list_entry(q->stream.next,
1136 struct videobuf_buffer, stream);
1137 } else if (req_events & (POLLIN | POLLRDNORM)) {
1139 __videobuf_read_start(q);
1142 } else if (NULL == q->read_buf) {
1143 q->read_buf = list_entry(q->stream.next,
1144 struct videobuf_buffer,
1146 list_del(&q->read_buf->stream);
1155 poll_wait(file, &buf->done, wait);
1156 if (buf->state == VIDEOBUF_DONE ||
1157 buf->state == VIDEOBUF_ERROR) {
1159 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1160 case V4L2_BUF_TYPE_VBI_OUTPUT:
1161 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1162 rc = POLLOUT | POLLWRNORM;
1165 rc = POLLIN | POLLRDNORM;
1170 videobuf_queue_unlock(q);
1173 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1175 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1180 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1182 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1183 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1187 videobuf_queue_lock(q);
1188 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1189 struct videobuf_buffer *buf = q->bufs[i];
1191 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1192 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1193 rc = CALL(q, mmap_mapper, q, buf, vma);
1197 videobuf_queue_unlock(q);
1201 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);