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");
292 mutex_lock(&q->lock);
294 dprintk(1,"reqbufs: streaming already exists\n");
298 if (!list_empty(&q->stream)) {
299 dprintk(1,"reqbufs: stream running\n");
305 if (count > VIDEO_MAX_FRAME)
306 count = VIDEO_MAX_FRAME;
308 q->ops->buf_setup(q,&count,&size);
309 size = PAGE_ALIGN(size);
310 dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
311 count, size, (count*size)>>PAGE_SHIFT);
313 retval = videobuf_mmap_setup(q,count,size,req->memory);
315 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
322 mutex_unlock(&q->lock);
326 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
328 if (unlikely(b->type != q->type)) {
329 dprintk(1,"querybuf: Wrong type.\n");
332 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
333 dprintk(1,"querybuf: index out of range.\n");
336 if (unlikely(NULL == q->bufs[b->index])) {
337 dprintk(1,"querybuf: buffer is null.\n");
340 videobuf_status(q,b,q->bufs[b->index],q->type);
344 int videobuf_qbuf(struct videobuf_queue *q,
345 struct v4l2_buffer *b)
347 struct videobuf_buffer *buf;
348 enum v4l2_field field;
349 unsigned long flags=0;
352 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
354 if (b->memory == V4L2_MEMORY_MMAP)
355 down_read(¤t->mm->mmap_sem);
357 mutex_lock(&q->lock);
360 dprintk(1,"qbuf: Reading running...\n");
364 if (b->type != q->type) {
365 dprintk(1,"qbuf: Wrong type.\n");
368 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
369 dprintk(1,"qbuf: index out of range.\n");
372 buf = q->bufs[b->index];
374 dprintk(1,"qbuf: buffer is null.\n");
377 MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
378 if (buf->memory != b->memory) {
379 dprintk(1,"qbuf: memory type is wrong.\n");
382 if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
383 dprintk(1,"qbuf: buffer is already queued or active.\n");
387 if (b->flags & V4L2_BUF_FLAG_INPUT) {
388 if (b->input >= q->inputs) {
389 dprintk(1,"qbuf: wrong input.\n");
392 buf->input = b->input;
398 case V4L2_MEMORY_MMAP:
399 if (0 == buf->baddr) {
400 dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
404 case V4L2_MEMORY_USERPTR:
405 if (b->length < buf->bsize) {
406 dprintk(1,"qbuf: buffer length is not enough\n");
409 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
410 q->ops->buf_release(q,buf);
411 buf->baddr = b->m.userptr;
413 case V4L2_MEMORY_OVERLAY:
414 buf->boff = b->m.offset;
417 dprintk(1,"qbuf: wrong memory type\n");
421 dprintk(1,"qbuf: requesting next field\n");
422 field = videobuf_next_field(q);
423 retval = q->ops->buf_prepare(q,buf,field);
425 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
429 list_add_tail(&buf->stream,&q->stream);
432 spin_lock_irqsave(q->irqlock,flags);
433 q->ops->buf_queue(q,buf);
435 spin_unlock_irqrestore(q->irqlock,flags);
437 dprintk(1,"qbuf: succeded\n");
441 mutex_unlock(&q->lock);
443 if (b->memory == V4L2_MEMORY_MMAP)
444 up_read(¤t->mm->mmap_sem);
449 int videobuf_dqbuf(struct videobuf_queue *q,
450 struct v4l2_buffer *b, int nonblocking)
452 struct videobuf_buffer *buf;
455 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
457 mutex_lock(&q->lock);
460 dprintk(1,"dqbuf: Reading running...\n");
464 if (b->type != q->type) {
465 dprintk(1,"dqbuf: Wrong type.\n");
468 if (list_empty(&q->stream)) {
469 dprintk(1,"dqbuf: stream running\n");
472 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
473 retval = videobuf_waiton(buf, nonblocking, 1);
475 dprintk(1,"dqbuf: waiton returned %d\n",retval);
478 switch (buf->state) {
480 dprintk(1,"dqbuf: state is error\n");
483 buf->state = STATE_IDLE;
486 dprintk(1,"dqbuf: state is done\n");
488 buf->state = STATE_IDLE;
491 dprintk(1,"dqbuf: state invalid\n");
495 list_del(&buf->stream);
496 memset(b,0,sizeof(*b));
497 videobuf_status(q,b,buf,q->type);
500 mutex_unlock(&q->lock);
504 int videobuf_streamon(struct videobuf_queue *q)
506 struct videobuf_buffer *buf;
507 struct list_head *list;
508 unsigned long flags=0;
511 mutex_lock(&q->lock);
520 spin_lock_irqsave(q->irqlock,flags);
521 list_for_each(list,&q->stream) {
522 buf = list_entry(list, struct videobuf_buffer, stream);
523 if (buf->state == STATE_PREPARED)
524 q->ops->buf_queue(q,buf);
527 spin_unlock_irqrestore(q->irqlock,flags);
530 mutex_unlock(&q->lock);
534 int videobuf_streamoff(struct videobuf_queue *q)
536 int retval = -EINVAL;
538 mutex_lock(&q->lock);
541 videobuf_queue_cancel(q);
546 mutex_unlock(&q->lock);
550 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
552 size_t count, loff_t *ppos)
554 enum v4l2_field field;
555 unsigned long flags=0;
558 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
561 q->read_buf = videobuf_alloc(q);
562 if (NULL == q->read_buf)
565 q->read_buf->memory = V4L2_MEMORY_USERPTR;
566 q->read_buf->baddr = (unsigned long)data;
567 q->read_buf->bsize = count;
569 field = videobuf_next_field(q);
570 retval = q->ops->buf_prepare(q,q->read_buf,field);
574 /* start capture & wait */
576 spin_lock_irqsave(q->irqlock,flags);
577 q->ops->buf_queue(q,q->read_buf);
579 spin_unlock_irqrestore(q->irqlock,flags);
580 retval = videobuf_waiton(q->read_buf,0,0);
582 CALL(q,sync,q,q->read_buf);
583 if (STATE_ERROR == q->read_buf->state)
586 retval = q->read_buf->size;
591 q->ops->buf_release(q,q->read_buf);
597 ssize_t videobuf_read_one(struct videobuf_queue *q,
598 char __user *data, size_t count, loff_t *ppos,
601 enum v4l2_field field;
602 unsigned long flags=0;
603 unsigned size, nbufs;
606 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
608 mutex_lock(&q->lock);
611 q->ops->buf_setup(q,&nbufs,&size);
613 if (NULL == q->read_buf &&
616 retval = videobuf_read_zerocopy(q,data,count,ppos);
617 if (retval >= 0 || retval == -EIO)
620 /* fallback to kernel bounce buffer on failures */
623 if (NULL == q->read_buf) {
624 /* need to capture a new frame */
626 q->read_buf = videobuf_alloc(q);
628 dprintk(1,"video alloc=0x%p\n", q->read_buf);
629 if (NULL == q->read_buf)
631 q->read_buf->memory = V4L2_MEMORY_USERPTR;
632 q->read_buf->bsize = count; /* preferred size */
633 field = videobuf_next_field(q);
634 retval = q->ops->buf_prepare(q,q->read_buf,field);
642 spin_lock_irqsave(q->irqlock,flags);
644 q->ops->buf_queue(q,q->read_buf);
646 spin_unlock_irqrestore(q->irqlock,flags);
650 /* wait until capture is done */
651 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
655 CALL(q,sync,q,q->read_buf);
657 if (STATE_ERROR == q->read_buf->state) {
658 /* catch I/O errors */
659 q->ops->buf_release(q,q->read_buf);
666 /* Copy to userspace */
667 retval=CALL(q,copy_to_user,q,data,count,nonblocking);
671 q->read_off += retval;
672 if (q->read_off == q->read_buf->size) {
673 /* all data copied, cleanup */
674 q->ops->buf_release(q,q->read_buf);
680 mutex_unlock(&q->lock);
684 int videobuf_read_start(struct videobuf_queue *q)
686 enum v4l2_field field;
687 unsigned long flags=0;
688 int count = 0, size = 0;
691 q->ops->buf_setup(q,&count,&size);
694 if (count > VIDEO_MAX_FRAME)
695 count = VIDEO_MAX_FRAME;
696 size = PAGE_ALIGN(size);
698 err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
702 for (i = 0; i < count; i++) {
703 field = videobuf_next_field(q);
704 err = q->ops->buf_prepare(q,q->bufs[i],field);
707 list_add_tail(&q->bufs[i]->stream, &q->stream);
710 spin_lock_irqsave(q->irqlock,flags);
711 for (i = 0; i < count; i++)
712 q->ops->buf_queue(q,q->bufs[i]);
714 spin_unlock_irqrestore(q->irqlock,flags);
719 void videobuf_read_stop(struct videobuf_queue *q)
723 videobuf_queue_cancel(q);
724 videobuf_mmap_free(q);
725 INIT_LIST_HEAD(&q->stream);
726 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
727 if (NULL == q->bufs[i])
736 ssize_t videobuf_read_stream(struct videobuf_queue *q,
737 char __user *data, size_t count, loff_t *ppos,
738 int vbihack, int nonblocking)
741 unsigned long flags=0;
743 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
745 dprintk(2,"%s\n",__FUNCTION__);
746 mutex_lock(&q->lock);
751 retval = videobuf_read_start(q);
758 /* get / wait for data */
759 if (NULL == q->read_buf) {
760 q->read_buf = list_entry(q->stream.next,
761 struct videobuf_buffer,
763 list_del(&q->read_buf->stream);
766 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
773 if (q->read_buf->state == STATE_DONE) {
774 rc = CALL (q,copy_stream, q, data, count,
775 retval, vbihack, nonblocking);
785 q->read_off = q->read_buf->size;
790 /* requeue buffer when done with copying */
791 if (q->read_off == q->read_buf->size) {
792 list_add_tail(&q->read_buf->stream,
795 spin_lock_irqsave(q->irqlock,flags);
796 q->ops->buf_queue(q,q->read_buf);
798 spin_unlock_irqrestore(q->irqlock,flags);
806 mutex_unlock(&q->lock);
810 unsigned int videobuf_poll_stream(struct file *file,
811 struct videobuf_queue *q,
814 struct videobuf_buffer *buf = NULL;
817 mutex_lock(&q->lock);
819 if (!list_empty(&q->stream))
820 buf = list_entry(q->stream.next,
821 struct videobuf_buffer, stream);
824 videobuf_read_start(q);
827 } else if (NULL == q->read_buf) {
828 q->read_buf = list_entry(q->stream.next,
829 struct videobuf_buffer,
831 list_del(&q->read_buf->stream);
840 poll_wait(file, &buf->done, wait);
841 if (buf->state == STATE_DONE ||
842 buf->state == STATE_ERROR)
843 rc = POLLIN|POLLRDNORM;
845 mutex_unlock(&q->lock);
849 int videobuf_mmap_setup(struct videobuf_queue *q,
850 unsigned int bcount, unsigned int bsize,
851 enum v4l2_memory memory)
856 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
858 err = videobuf_mmap_free(q);
862 /* Allocate and initialize buffers */
863 for (i = 0; i < bcount; i++) {
864 q->bufs[i] = videobuf_alloc(q);
867 q->bufs[i]->input = UNSET;
868 q->bufs[i]->memory = memory;
869 q->bufs[i]->bsize = bsize;
871 case V4L2_MEMORY_MMAP:
872 q->bufs[i]->boff = bsize * i;
874 case V4L2_MEMORY_USERPTR:
875 case V4L2_MEMORY_OVERLAY:
881 dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
887 int videobuf_mmap_free(struct videobuf_queue *q)
895 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
897 rc = CALL(q,mmap_free,q);
901 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
902 if (NULL == q->bufs[i])
904 q->ops->buf_release(q,q->bufs[i]);
912 int videobuf_mmap_mapper(struct videobuf_queue *q,
913 struct vm_area_struct *vma)
917 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
919 mutex_lock(&q->lock);
920 retval=CALL(q,mmap_mapper,q,vma);
921 mutex_unlock(&q->lock);
926 #ifdef CONFIG_VIDEO_V4L1_COMPAT
927 int videobuf_cgmbuf(struct videobuf_queue *q,
928 struct video_mbuf *mbuf, int count)
930 struct v4l2_requestbuffers req;
933 MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
935 memset(&req,0,sizeof(req));
938 req.memory = V4L2_MEMORY_MMAP;
939 rc = videobuf_reqbufs(q,&req);
943 mbuf->frames = req.count;
945 for (i = 0; i < mbuf->frames; i++) {
946 mbuf->offsets[i] = q->bufs[i]->boff;
947 mbuf->size += q->bufs[i]->bsize;
954 /* --------------------------------------------------------------------- */
956 EXPORT_SYMBOL_GPL(videobuf_waiton);
957 EXPORT_SYMBOL_GPL(videobuf_iolock);
959 EXPORT_SYMBOL_GPL(videobuf_alloc);
961 EXPORT_SYMBOL_GPL(videobuf_queue_init);
962 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
963 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
965 EXPORT_SYMBOL_GPL(videobuf_next_field);
966 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
967 EXPORT_SYMBOL_GPL(videobuf_querybuf);
968 EXPORT_SYMBOL_GPL(videobuf_qbuf);
969 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
970 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
971 EXPORT_SYMBOL_GPL(videobuf_streamon);
972 EXPORT_SYMBOL_GPL(videobuf_streamoff);
974 EXPORT_SYMBOL_GPL(videobuf_read_start);
975 EXPORT_SYMBOL_GPL(videobuf_read_stop);
976 EXPORT_SYMBOL_GPL(videobuf_read_stream);
977 EXPORT_SYMBOL_GPL(videobuf_read_one);
978 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
980 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
981 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
982 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);