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>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
22 #include <media/videobuf-core.h>
24 #define MAGIC_BUFFER 0x20070728
25 #define MAGIC_CHECK(is,should) if (unlikely((is) != (should))) \
26 { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
29 module_param(debug, int, 0644);
31 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
32 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
33 MODULE_LICENSE("GPL");
35 #define dprintk(level, fmt, arg...) if (debug >= level) \
36 printk(KERN_DEBUG "vbuf: " fmt , ## arg)
38 /* --------------------------------------------------------------------- */
40 #define CALL(q, f, arg...) \
41 ( (q->int_ops->f)? q->int_ops->f(arg) : 0)
43 void* videobuf_alloc(struct videobuf_queue* q)
45 struct videobuf_buffer *vb;
47 BUG_ON (q->msize<sizeof(*vb));
49 if (!q->int_ops || !q->int_ops->alloc) {
50 printk(KERN_ERR "No specific ops defined!\n");
54 vb = q->int_ops->alloc(q->msize);
57 init_waitqueue_head(&vb->done);
58 vb->magic = MAGIC_BUFFER;
64 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
67 DECLARE_WAITQUEUE(wait, current);
69 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
70 add_wait_queue(&vb->done, &wait);
71 while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
76 set_current_state(intr ? TASK_INTERRUPTIBLE
77 : TASK_UNINTERRUPTIBLE);
78 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
80 set_current_state(TASK_RUNNING);
81 if (intr && signal_pending(current)) {
82 dprintk(1,"buffer waiton: -EINTR\n");
87 remove_wait_queue(&vb->done, &wait);
91 int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
92 struct v4l2_framebuffer *fbuf)
94 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
95 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
97 return CALL(q,iolock,q,vb,fbuf);
100 /* --------------------------------------------------------------------- */
103 void videobuf_queue_init(struct videobuf_queue* q,
104 struct videobuf_queue_ops *ops,
107 enum v4l2_buf_type type,
108 enum v4l2_field field,
112 memset(q,0,sizeof(*q));
113 q->irqlock = irqlock;
121 /* All buffer operations are mandatory */
122 BUG_ON (!q->ops->buf_setup);
123 BUG_ON (!q->ops->buf_prepare);
124 BUG_ON (!q->ops->buf_queue);
125 BUG_ON (!q->ops->buf_release);
127 mutex_init(&q->lock);
128 INIT_LIST_HEAD(&q->stream);
131 int videobuf_queue_is_busy(struct videobuf_queue *q)
135 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
138 dprintk(1,"busy: streaming active\n");
142 dprintk(1,"busy: pending read #1\n");
146 dprintk(1,"busy: pending read #2\n");
149 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
150 if (NULL == q->bufs[i])
152 if (q->bufs[i]->map) {
153 dprintk(1,"busy: buffer #%d mapped\n",i);
156 if (q->bufs[i]->state == STATE_QUEUED) {
157 dprintk(1,"busy: buffer #%d queued\n",i);
160 if (q->bufs[i]->state == STATE_ACTIVE) {
161 dprintk(1,"busy: buffer #%d avtive\n",i);
168 void videobuf_queue_cancel(struct videobuf_queue *q)
170 unsigned long flags=0;
173 /* remove queued buffers from list */
175 spin_lock_irqsave(q->irqlock,flags);
176 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
177 if (NULL == q->bufs[i])
179 if (q->bufs[i]->state == STATE_QUEUED) {
180 list_del(&q->bufs[i]->queue);
181 q->bufs[i]->state = STATE_ERROR;
185 spin_unlock_irqrestore(q->irqlock,flags);
187 /* free all buffers + clear queue */
188 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
189 if (NULL == q->bufs[i])
191 q->ops->buf_release(q,q->bufs[i]);
193 INIT_LIST_HEAD(&q->stream);
196 /* --------------------------------------------------------------------- */
198 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
200 enum v4l2_field field = q->field;
202 BUG_ON(V4L2_FIELD_ANY == field);
204 if (V4L2_FIELD_ALTERNATE == field) {
205 if (V4L2_FIELD_TOP == q->last) {
206 field = V4L2_FIELD_BOTTOM;
207 q->last = V4L2_FIELD_BOTTOM;
209 field = V4L2_FIELD_TOP;
210 q->last = V4L2_FIELD_TOP;
216 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
217 struct videobuf_buffer *vb, enum v4l2_buf_type type)
219 MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
220 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
225 b->memory = vb->memory;
227 case V4L2_MEMORY_MMAP:
228 b->m.offset = vb->boff;
229 b->length = vb->bsize;
231 case V4L2_MEMORY_USERPTR:
232 b->m.userptr = vb->baddr;
233 b->length = vb->bsize;
235 case V4L2_MEMORY_OVERLAY:
236 b->m.offset = vb->boff;
242 b->flags |= V4L2_BUF_FLAG_MAPPED;
248 b->flags |= V4L2_BUF_FLAG_QUEUED;
252 b->flags |= V4L2_BUF_FLAG_DONE;
254 case STATE_NEEDS_INIT:
260 if (vb->input != UNSET) {
261 b->flags |= V4L2_BUF_FLAG_INPUT;
262 b->input = vb->input;
265 b->field = vb->field;
266 b->timestamp = vb->ts;
267 b->bytesused = vb->size;
268 b->sequence = vb->field_count >> 1;
271 int videobuf_reqbufs(struct videobuf_queue *q,
272 struct v4l2_requestbuffers *req)
274 unsigned int size,count;
277 if (req->type != q->type) {
278 dprintk(1,"reqbufs: queue type invalid\n");
281 if (req->count < 1) {
282 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
285 if (req->memory != V4L2_MEMORY_MMAP &&
286 req->memory != V4L2_MEMORY_USERPTR &&
287 req->memory != V4L2_MEMORY_OVERLAY) {
288 dprintk(1,"reqbufs: memory type invalid\n");
293 dprintk(1,"reqbufs: streaming already exists\n");
296 if (!list_empty(&q->stream)) {
297 dprintk(1,"reqbufs: stream running\n");
301 mutex_lock(&q->lock);
303 if (count > VIDEO_MAX_FRAME)
304 count = VIDEO_MAX_FRAME;
306 q->ops->buf_setup(q,&count,&size);
307 size = PAGE_ALIGN(size);
308 dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
309 count, size, (count*size)>>PAGE_SHIFT);
311 retval = videobuf_mmap_setup(q,count,size,req->memory);
313 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
320 mutex_unlock(&q->lock);
324 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
326 if (unlikely(b->type != q->type)) {
327 dprintk(1,"querybuf: Wrong type.\n");
330 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
331 dprintk(1,"querybuf: index out of range.\n");
334 if (unlikely(NULL == q->bufs[b->index])) {
335 dprintk(1,"querybuf: buffer is null.\n");
338 videobuf_status(q,b,q->bufs[b->index],q->type);
342 int videobuf_qbuf(struct videobuf_queue *q,
343 struct v4l2_buffer *b)
345 struct videobuf_buffer *buf;
346 enum v4l2_field field;
347 unsigned long flags=0;
350 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
352 mutex_lock(&q->lock);
355 dprintk(1,"qbuf: Reading running...\n");
359 if (b->type != q->type) {
360 dprintk(1,"qbuf: Wrong type.\n");
363 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
364 dprintk(1,"qbuf: index out of range.\n");
367 buf = q->bufs[b->index];
369 dprintk(1,"qbuf: buffer is null.\n");
372 MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
373 if (buf->memory != b->memory) {
374 dprintk(1,"qbuf: memory type is wrong.\n");
377 if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
378 dprintk(1,"qbuf: buffer is already queued or active.\n");
382 if (b->flags & V4L2_BUF_FLAG_INPUT) {
383 if (b->input >= q->inputs) {
384 dprintk(1,"qbuf: wrong input.\n");
387 buf->input = b->input;
393 case V4L2_MEMORY_MMAP:
394 if (0 == buf->baddr) {
395 dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
399 case V4L2_MEMORY_USERPTR:
400 if (b->length < buf->bsize) {
401 dprintk(1,"qbuf: buffer length is not enough\n");
404 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
405 q->ops->buf_release(q,buf);
406 buf->baddr = b->m.userptr;
408 case V4L2_MEMORY_OVERLAY:
409 buf->boff = b->m.offset;
412 dprintk(1,"qbuf: wrong memory type\n");
416 dprintk(1,"qbuf: requesting next field\n");
417 field = videobuf_next_field(q);
418 retval = q->ops->buf_prepare(q,buf,field);
420 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
424 list_add_tail(&buf->stream,&q->stream);
427 spin_lock_irqsave(q->irqlock,flags);
428 q->ops->buf_queue(q,buf);
430 spin_unlock_irqrestore(q->irqlock,flags);
432 dprintk(1,"qbuf: succeded\n");
436 mutex_unlock(&q->lock);
440 int videobuf_dqbuf(struct videobuf_queue *q,
441 struct v4l2_buffer *b, int nonblocking)
443 struct videobuf_buffer *buf;
446 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
448 mutex_lock(&q->lock);
451 dprintk(1,"dqbuf: Reading running...\n");
455 if (b->type != q->type) {
456 dprintk(1,"dqbuf: Wrong type.\n");
459 if (list_empty(&q->stream)) {
460 dprintk(1,"dqbuf: stream running\n");
463 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
464 retval = videobuf_waiton(buf, nonblocking, 1);
466 dprintk(1,"dqbuf: waiton returned %d\n",retval);
469 switch (buf->state) {
471 dprintk(1,"dqbuf: state is error\n");
474 buf->state = STATE_IDLE;
477 dprintk(1,"dqbuf: state is done\n");
479 buf->state = STATE_IDLE;
482 dprintk(1,"dqbuf: state invalid\n");
486 list_del(&buf->stream);
487 memset(b,0,sizeof(*b));
488 videobuf_status(q,b,buf,q->type);
491 mutex_unlock(&q->lock);
495 int videobuf_streamon(struct videobuf_queue *q)
497 struct videobuf_buffer *buf;
498 struct list_head *list;
499 unsigned long flags=0;
502 mutex_lock(&q->lock);
511 spin_lock_irqsave(q->irqlock,flags);
512 list_for_each(list,&q->stream) {
513 buf = list_entry(list, struct videobuf_buffer, stream);
514 if (buf->state == STATE_PREPARED)
515 q->ops->buf_queue(q,buf);
518 spin_unlock_irqrestore(q->irqlock,flags);
521 mutex_unlock(&q->lock);
525 int videobuf_streamoff(struct videobuf_queue *q)
527 int retval = -EINVAL;
529 mutex_lock(&q->lock);
532 videobuf_queue_cancel(q);
537 mutex_unlock(&q->lock);
541 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
543 size_t count, loff_t *ppos)
545 enum v4l2_field field;
546 unsigned long flags=0;
549 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
552 q->read_buf = videobuf_alloc(q);
553 if (NULL == q->read_buf)
556 q->read_buf->memory = V4L2_MEMORY_USERPTR;
557 q->read_buf->baddr = (unsigned long)data;
558 q->read_buf->bsize = count;
560 field = videobuf_next_field(q);
561 retval = q->ops->buf_prepare(q,q->read_buf,field);
565 /* start capture & wait */
567 spin_lock_irqsave(q->irqlock,flags);
568 q->ops->buf_queue(q,q->read_buf);
570 spin_unlock_irqrestore(q->irqlock,flags);
571 retval = videobuf_waiton(q->read_buf,0,0);
573 CALL(q,sync,q,q->read_buf);
574 if (STATE_ERROR == q->read_buf->state)
577 retval = q->read_buf->size;
582 q->ops->buf_release(q,q->read_buf);
588 ssize_t videobuf_read_one(struct videobuf_queue *q,
589 char __user *data, size_t count, loff_t *ppos,
592 enum v4l2_field field;
593 unsigned long flags=0;
594 unsigned size, nbufs;
597 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
599 mutex_lock(&q->lock);
602 q->ops->buf_setup(q,&nbufs,&size);
604 if (NULL == q->read_buf &&
607 retval = videobuf_read_zerocopy(q,data,count,ppos);
608 if (retval >= 0 || retval == -EIO)
611 /* fallback to kernel bounce buffer on failures */
614 if (NULL == q->read_buf) {
615 /* need to capture a new frame */
617 q->read_buf = videobuf_alloc(q);
619 dprintk(1,"video alloc=0x%p\n", q->read_buf);
620 if (NULL == q->read_buf)
622 q->read_buf->memory = V4L2_MEMORY_USERPTR;
623 q->read_buf->bsize = count; /* preferred size */
624 field = videobuf_next_field(q);
625 retval = q->ops->buf_prepare(q,q->read_buf,field);
633 spin_lock_irqsave(q->irqlock,flags);
635 q->ops->buf_queue(q,q->read_buf);
637 spin_unlock_irqrestore(q->irqlock,flags);
641 /* wait until capture is done */
642 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
646 CALL(q,sync,q,q->read_buf);
648 if (STATE_ERROR == q->read_buf->state) {
649 /* catch I/O errors */
650 q->ops->buf_release(q,q->read_buf);
657 /* Copy to userspace */
658 retval=CALL(q,copy_to_user,q,data,count,nonblocking);
662 q->read_off += retval;
663 if (q->read_off == q->read_buf->size) {
664 /* all data copied, cleanup */
665 q->ops->buf_release(q,q->read_buf);
671 mutex_unlock(&q->lock);
675 int videobuf_read_start(struct videobuf_queue *q)
677 enum v4l2_field field;
678 unsigned long flags=0;
679 int count = 0, size = 0;
682 q->ops->buf_setup(q,&count,&size);
685 if (count > VIDEO_MAX_FRAME)
686 count = VIDEO_MAX_FRAME;
687 size = PAGE_ALIGN(size);
689 err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
693 for (i = 0; i < count; i++) {
694 field = videobuf_next_field(q);
695 err = q->ops->buf_prepare(q,q->bufs[i],field);
698 list_add_tail(&q->bufs[i]->stream, &q->stream);
701 spin_lock_irqsave(q->irqlock,flags);
702 for (i = 0; i < count; i++)
703 q->ops->buf_queue(q,q->bufs[i]);
705 spin_unlock_irqrestore(q->irqlock,flags);
710 void videobuf_read_stop(struct videobuf_queue *q)
714 videobuf_queue_cancel(q);
715 videobuf_mmap_free(q);
716 INIT_LIST_HEAD(&q->stream);
717 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
718 if (NULL == q->bufs[i])
727 ssize_t videobuf_read_stream(struct videobuf_queue *q,
728 char __user *data, size_t count, loff_t *ppos,
729 int vbihack, int nonblocking)
732 unsigned long flags=0;
734 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
736 dprintk(2,"%s\n",__FUNCTION__);
737 mutex_lock(&q->lock);
742 retval = videobuf_read_start(q);
749 /* get / wait for data */
750 if (NULL == q->read_buf) {
751 q->read_buf = list_entry(q->stream.next,
752 struct videobuf_buffer,
754 list_del(&q->read_buf->stream);
757 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
764 if (q->read_buf->state == STATE_DONE) {
765 rc = CALL (q,copy_stream, q, data, count,
766 retval, vbihack, nonblocking);
776 q->read_off = q->read_buf->size;
781 /* requeue buffer when done with copying */
782 if (q->read_off == q->read_buf->size) {
783 list_add_tail(&q->read_buf->stream,
786 spin_lock_irqsave(q->irqlock,flags);
787 q->ops->buf_queue(q,q->read_buf);
789 spin_unlock_irqrestore(q->irqlock,flags);
797 mutex_unlock(&q->lock);
801 unsigned int videobuf_poll_stream(struct file *file,
802 struct videobuf_queue *q,
805 struct videobuf_buffer *buf = NULL;
808 mutex_lock(&q->lock);
810 if (!list_empty(&q->stream))
811 buf = list_entry(q->stream.next,
812 struct videobuf_buffer, stream);
815 videobuf_read_start(q);
818 } else if (NULL == q->read_buf) {
819 q->read_buf = list_entry(q->stream.next,
820 struct videobuf_buffer,
822 list_del(&q->read_buf->stream);
831 poll_wait(file, &buf->done, wait);
832 if (buf->state == STATE_DONE ||
833 buf->state == STATE_ERROR)
834 rc = POLLIN|POLLRDNORM;
836 mutex_unlock(&q->lock);
840 int videobuf_mmap_setup(struct videobuf_queue *q,
841 unsigned int bcount, unsigned int bsize,
842 enum v4l2_memory memory)
847 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
849 err = videobuf_mmap_free(q);
853 /* Allocate and initialize buffers */
854 for (i = 0; i < bcount; i++) {
855 q->bufs[i] = videobuf_alloc(q);
858 q->bufs[i]->input = UNSET;
859 q->bufs[i]->memory = memory;
860 q->bufs[i]->bsize = bsize;
862 case V4L2_MEMORY_MMAP:
863 q->bufs[i]->boff = bsize * i;
865 case V4L2_MEMORY_USERPTR:
866 case V4L2_MEMORY_OVERLAY:
872 dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
878 int videobuf_mmap_free(struct videobuf_queue *q)
886 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
888 rc = CALL(q,mmap_free,q);
892 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
893 if (NULL == q->bufs[i])
895 q->ops->buf_release(q,q->bufs[i]);
903 int videobuf_mmap_mapper(struct videobuf_queue *q,
904 struct vm_area_struct *vma)
908 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
910 mutex_lock(&q->lock);
911 retval=CALL(q,mmap_mapper,q,vma);
912 mutex_unlock(&q->lock);
917 #ifdef CONFIG_VIDEO_V4L1_COMPAT
918 int videobuf_cgmbuf(struct videobuf_queue *q,
919 struct video_mbuf *mbuf, int count)
921 struct v4l2_requestbuffers req;
924 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
926 memset(&req,0,sizeof(req));
929 req.memory = V4L2_MEMORY_MMAP;
930 rc = videobuf_reqbufs(q,&req);
934 mbuf->frames = req.count;
936 for (i = 0; i < mbuf->frames; i++) {
937 mbuf->offsets[i] = q->bufs[i]->boff;
938 mbuf->size += q->bufs[i]->bsize;
945 /* --------------------------------------------------------------------- */
947 EXPORT_SYMBOL_GPL(videobuf_waiton);
948 EXPORT_SYMBOL_GPL(videobuf_iolock);
950 EXPORT_SYMBOL_GPL(videobuf_alloc);
952 EXPORT_SYMBOL_GPL(videobuf_queue_init);
953 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
954 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
956 EXPORT_SYMBOL_GPL(videobuf_next_field);
957 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
958 EXPORT_SYMBOL_GPL(videobuf_querybuf);
959 EXPORT_SYMBOL_GPL(videobuf_qbuf);
960 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
961 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
962 EXPORT_SYMBOL_GPL(videobuf_streamon);
963 EXPORT_SYMBOL_GPL(videobuf_streamoff);
965 EXPORT_SYMBOL_GPL(videobuf_read_start);
966 EXPORT_SYMBOL_GPL(videobuf_read_stop);
967 EXPORT_SYMBOL_GPL(videobuf_read_stream);
968 EXPORT_SYMBOL_GPL(videobuf_read_one);
969 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
971 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
972 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
973 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);