1 files changed, 976 insertions, 0 deletions

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
new file mode 100644
index 00000000000..256501384af
--- /dev/null
+++ b/drivers/media/video/videobuf-core.c
@@ -0,0 +1,976 @@
+/*
+ * generic helper functions for handling video4linux capture buffers
+ *
+ * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ *
+ * Highly based on video-buf written originally by:
+ * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
+ * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ * (c) 2006 Ted Walther and John Sokol
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+
+#include <media/videobuf-core.h>
+
+#define MAGIC_BUFFER 0x20070728
+#define MAGIC_CHECK(is,should)	if (unlikely((is) != (should))) \
+	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
+
+static int debug = 0;
+module_param(debug, int, 0644);
+
+MODULE_DESCRIPTION("helper module to manage video4linux buffers");
+MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
+MODULE_LICENSE("GPL");
+
+#define dprintk(level, fmt, arg...)	if (debug >= level) \
+	printk(KERN_DEBUG "vbuf: " fmt , ## arg)
+
+/* --------------------------------------------------------------------- */
+
+#define CALL(q, f, arg...)						\
+	( (q->int_ops->f)? q->int_ops->f(arg) : 0)
+
+void* videobuf_alloc(struct videobuf_queue* q)
+{
+	struct videobuf_buffer *vb;
+
+	BUG_ON (q->msize<sizeof(*vb));
+
+	if (!q->int_ops || !q->int_ops->alloc) {
+		printk(KERN_ERR "No specific ops defined!\n");
+		BUG();
+	}
+
+	vb = q->int_ops->alloc(q->msize);
+
+	if (NULL != vb) {
+		init_waitqueue_head(&vb->done);
+		vb->magic     = MAGIC_BUFFER;
+	}
+
+	return vb;
+}
+
+int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
+{
+	int retval = 0;
+	DECLARE_WAITQUEUE(wait, current);
+
+	MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
+	add_wait_queue(&vb->done, &wait);
+	while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
+		if (non_blocking) {
+			retval = -EAGAIN;
+			break;
+		}
+		set_current_state(intr  ? TASK_INTERRUPTIBLE
+					: TASK_UNINTERRUPTIBLE);
+		if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
+			schedule();
+		set_current_state(TASK_RUNNING);
+		if (intr && signal_pending(current)) {
+			dprintk(1,"buffer waiton: -EINTR\n");
+			retval = -EINTR;
+			break;
+		}
+	}
+	remove_wait_queue(&vb->done, &wait);
+	return retval;
+}
+
+int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
+		    struct v4l2_framebuffer *fbuf)
+{
+	MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	return CALL(q,iolock,q,vb,fbuf);
+}
+
+/* --------------------------------------------------------------------- */
+
+
+void videobuf_queue_init(struct videobuf_queue* q,
+			 struct videobuf_queue_ops *ops,
+			 void *dev,
+			 spinlock_t *irqlock,
+			 enum v4l2_buf_type type,
+			 enum v4l2_field field,
+			 unsigned int msize,
+			 void *priv)
+{
+	memset(q,0,sizeof(*q));
+	q->irqlock = irqlock;
+	q->dev     = dev;
+	q->type    = type;
+	q->field   = field;
+	q->msize   = msize;
+	q->ops     = ops;
+	q->priv_data = priv;
+
+	/* All buffer operations are mandatory */
+	BUG_ON (!q->ops->buf_setup);
+	BUG_ON (!q->ops->buf_prepare);
+	BUG_ON (!q->ops->buf_queue);
+	BUG_ON (!q->ops->buf_release);
+
+	mutex_init(&q->lock);
+	INIT_LIST_HEAD(&q->stream);
+}
+
+int videobuf_queue_is_busy(struct videobuf_queue *q)
+{
+	int i;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	if (q->streaming) {
+		dprintk(1,"busy: streaming active\n");
+		return 1;
+	}
+	if (q->reading) {
+		dprintk(1,"busy: pending read #1\n");
+		return 1;
+	}
+	if (q->read_buf) {
+		dprintk(1,"busy: pending read #2\n");
+		return 1;
+	}
+	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+		if (NULL == q->bufs[i])
+			continue;
+		if (CALL(q,is_mmapped,q->bufs[i])) {
+			dprintk(1,"busy: buffer #%d mapped\n",i);
+			return 1;
+		}
+		if (q->bufs[i]->state == STATE_QUEUED) {
+			dprintk(1,"busy: buffer #%d queued\n",i);
+			return 1;
+		}
+		if (q->bufs[i]->state == STATE_ACTIVE) {
+			dprintk(1,"busy: buffer #%d avtive\n",i);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+void videobuf_queue_cancel(struct videobuf_queue *q)
+{
+	unsigned long flags=0;
+	int i;
+
+	/* remove queued buffers from list */
+	if (q->irqlock)
+		spin_lock_irqsave(q->irqlock,flags);
+	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+		if (NULL == q->bufs[i])
+			continue;
+		if (q->bufs[i]->state == STATE_QUEUED) {
+			list_del(&q->bufs[i]->queue);
+			q->bufs[i]->state = STATE_ERROR;
+		}
+	}
+	if (q->irqlock)
+		spin_unlock_irqrestore(q->irqlock,flags);
+
+	/* free all buffers + clear queue */
+	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+		if (NULL == q->bufs[i])
+			continue;
+		q->ops->buf_release(q,q->bufs[i]);
+	}
+	INIT_LIST_HEAD(&q->stream);
+}
+
+/* --------------------------------------------------------------------- */
+
+enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
+{
+	enum v4l2_field field = q->field;
+
+	BUG_ON(V4L2_FIELD_ANY == field);
+
+	if (V4L2_FIELD_ALTERNATE == field) {
+		if (V4L2_FIELD_TOP == q->last) {
+			field   = V4L2_FIELD_BOTTOM;
+			q->last = V4L2_FIELD_BOTTOM;
+		} else {
+			field   = V4L2_FIELD_TOP;
+			q->last = V4L2_FIELD_TOP;
+		}
+	}
+	return field;
+}
+
+static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
+			    struct videobuf_buffer *vb, enum v4l2_buf_type type)
+{
+	MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	b->index    = vb->i;
+	b->type     = type;
+
+	b->memory   = vb->memory;
+	switch (b->memory) {
+	case V4L2_MEMORY_MMAP:
+		b->m.offset  = vb->boff;
+		b->length    = vb->bsize;
+		break;
+	case V4L2_MEMORY_USERPTR:
+		b->m.userptr = vb->baddr;
+		b->length    = vb->bsize;
+		break;
+	case V4L2_MEMORY_OVERLAY:
+		b->m.offset  = vb->boff;
+		break;
+	}
+
+	b->flags    = 0;
+	if (CALL(q,is_mmapped,vb))
+		b->flags |= V4L2_BUF_FLAG_MAPPED;
+
+	switch (vb->state) {
+	case STATE_PREPARED:
+	case STATE_QUEUED:
+	case STATE_ACTIVE:
+		b->flags |= V4L2_BUF_FLAG_QUEUED;
+		break;
+	case STATE_DONE:
+	case STATE_ERROR:
+		b->flags |= V4L2_BUF_FLAG_DONE;
+		break;
+	case STATE_NEEDS_INIT:
+	case STATE_IDLE:
+		/* nothing */
+		break;
+	}
+
+	if (vb->input != UNSET) {
+		b->flags |= V4L2_BUF_FLAG_INPUT;
+		b->input  = vb->input;
+	}
+
+	b->field     = vb->field;
+	b->timestamp = vb->ts;
+	b->bytesused = vb->size;
+	b->sequence  = vb->field_count >> 1;
+}
+
+int videobuf_reqbufs(struct videobuf_queue *q,
+		 struct v4l2_requestbuffers *req)
+{
+	unsigned int size,count;
+	int retval;
+
+	if (req->type != q->type) {
+		dprintk(1,"reqbufs: queue type invalid\n");
+		return -EINVAL;
+	}
+	if (req->count < 1) {
+		dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
+		return -EINVAL;
+	}
+	if (req->memory != V4L2_MEMORY_MMAP     &&
+	    req->memory != V4L2_MEMORY_USERPTR  &&
+	    req->memory != V4L2_MEMORY_OVERLAY) {
+		dprintk(1,"reqbufs: memory type invalid\n");
+		return -EINVAL;
+	}
+
+	if (q->streaming) {
+		dprintk(1,"reqbufs: streaming already exists\n");
+		return -EBUSY;
+	}
+	if (!list_empty(&q->stream)) {
+		dprintk(1,"reqbufs: stream running\n");
+		return -EBUSY;
+	}
+
+	mutex_lock(&q->lock);
+	count = req->count;
+	if (count > VIDEO_MAX_FRAME)
+		count = VIDEO_MAX_FRAME;
+	size = 0;
+	q->ops->buf_setup(q,&count,&size);
+	size = PAGE_ALIGN(size);
+	dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
+		count, size, (count*size)>>PAGE_SHIFT);
+
+	retval = videobuf_mmap_setup(q,count,size,req->memory);
+	if (retval < 0) {
+		dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
+		goto done;
+	}
+
+	req->count = count;
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
+{
+	if (unlikely(b->type != q->type)) {
+		dprintk(1,"querybuf: Wrong type.\n");
+		return -EINVAL;
+	}
+	if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
+		dprintk(1,"querybuf: index out of range.\n");
+		return -EINVAL;
+	}
+	if (unlikely(NULL == q->bufs[b->index])) {
+		dprintk(1,"querybuf: buffer is null.\n");
+		return -EINVAL;
+	}
+	videobuf_status(q,b,q->bufs[b->index],q->type);
+	return 0;
+}
+
+int videobuf_qbuf(struct videobuf_queue *q,
+	      struct v4l2_buffer *b)
+{
+	struct videobuf_buffer *buf;
+	enum v4l2_field field;
+	unsigned long flags=0;
+	int retval;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	mutex_lock(&q->lock);
+	retval = -EBUSY;
+	if (q->reading) {
+		dprintk(1,"qbuf: Reading running...\n");
+		goto done;
+	}
+	retval = -EINVAL;
+	if (b->type != q->type) {
+		dprintk(1,"qbuf: Wrong type.\n");
+		goto done;
+	}
+	if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
+		dprintk(1,"qbuf: index out of range.\n");
+		goto done;
+	}
+	buf = q->bufs[b->index];
+	if (NULL == buf) {
+		dprintk(1,"qbuf: buffer is null.\n");
+		goto done;
+	}
+	MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
+	if (buf->memory != b->memory) {
+		dprintk(1,"qbuf: memory type is wrong.\n");
+		goto done;
+	}
+	if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
+		dprintk(1,"qbuf: buffer is already queued or active.\n");
+		goto done;
+	}
+
+	if (b->flags & V4L2_BUF_FLAG_INPUT) {
+		if (b->input >= q->inputs) {
+			dprintk(1,"qbuf: wrong input.\n");
+			goto done;
+		}
+		buf->input = b->input;
+	} else {
+		buf->input = UNSET;
+	}
+
+	switch (b->memory) {
+	case V4L2_MEMORY_MMAP:
+		if (0 == buf->baddr) {
+			dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
+			goto done;
+		}
+		break;
+	case V4L2_MEMORY_USERPTR:
+		if (b->length < buf->bsize) {
+			dprintk(1,"qbuf: buffer length is not enough\n");
+			goto done;
+		}
+		if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
+			q->ops->buf_release(q,buf);
+		buf->baddr = b->m.userptr;
+		break;
+	case V4L2_MEMORY_OVERLAY:
+		buf->boff = b->m.offset;
+		break;
+	default:
+		dprintk(1,"qbuf: wrong memory type\n");
+		goto done;
+	}
+
+	dprintk(1,"qbuf: requesting next field\n");
+	field = videobuf_next_field(q);
+	retval = q->ops->buf_prepare(q,buf,field);
+	if (0 != retval) {
+		dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
+		goto done;
+	}
+
+	list_add_tail(&buf->stream,&q->stream);
+	if (q->streaming) {
+		if (q->irqlock)
+			spin_lock_irqsave(q->irqlock,flags);
+		q->ops->buf_queue(q,buf);
+		if (q->irqlock)
+			spin_unlock_irqrestore(q->irqlock,flags);
+	}
+	dprintk(1,"qbuf: succeded\n");
+	retval = 0;
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+int videobuf_dqbuf(struct videobuf_queue *q,
+	       struct v4l2_buffer *b, int nonblocking)
+{
+	struct videobuf_buffer *buf;
+	int retval;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	mutex_lock(&q->lock);
+	retval = -EBUSY;
+	if (q->reading) {
+		dprintk(1,"dqbuf: Reading running...\n");
+		goto done;
+	}
+	retval = -EINVAL;
+	if (b->type != q->type) {
+		dprintk(1,"dqbuf: Wrong type.\n");
+		goto done;
+	}
+	if (list_empty(&q->stream)) {
+		dprintk(1,"dqbuf: stream running\n");
+		goto done;
+	}
+	buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
+	retval = videobuf_waiton(buf, nonblocking, 1);
+	if (retval < 0) {
+		dprintk(1,"dqbuf: waiton returned %d\n",retval);
+		goto done;
+	}
+	switch (buf->state) {
+	case STATE_ERROR:
+		dprintk(1,"dqbuf: state is error\n");
+		retval = -EIO;
+		CALL(q,sync,q, buf);
+		buf->state = STATE_IDLE;
+		break;
+	case STATE_DONE:
+		dprintk(1,"dqbuf: state is done\n");
+		CALL(q,sync,q, buf);
+		buf->state = STATE_IDLE;
+		break;
+	default:
+		dprintk(1,"dqbuf: state invalid\n");
+		retval = -EINVAL;
+		goto done;
+	}
+	list_del(&buf->stream);
+	memset(b,0,sizeof(*b));
+	videobuf_status(q,b,buf,q->type);
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+int videobuf_streamon(struct videobuf_queue *q)
+{
+	struct videobuf_buffer *buf;
+	struct list_head *list;
+	unsigned long flags=0;
+	int retval;
+
+	mutex_lock(&q->lock);
+	retval = -EBUSY;
+	if (q->reading)
+		goto done;
+	retval = 0;
+	if (q->streaming)
+		goto done;
+	q->streaming = 1;
+	if (q->irqlock)
+		spin_lock_irqsave(q->irqlock,flags);
+	list_for_each(list,&q->stream) {
+		buf = list_entry(list, struct videobuf_buffer, stream);
+		if (buf->state == STATE_PREPARED)
+			q->ops->buf_queue(q,buf);
+	}
+	if (q->irqlock)
+		spin_unlock_irqrestore(q->irqlock,flags);
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+int videobuf_streamoff(struct videobuf_queue *q)
+{
+	int retval = -EINVAL;
+
+	mutex_lock(&q->lock);
+	if (!q->streaming)
+		goto done;
+	videobuf_queue_cancel(q);
+	q->streaming = 0;
+	retval = 0;
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
+				      char __user *data,
+				      size_t count, loff_t *ppos)
+{
+	enum v4l2_field field;
+	unsigned long flags=0;
+	int retval;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	/* setup stuff */
+	q->read_buf = videobuf_alloc(q);
+	if (NULL == q->read_buf)
+		return -ENOMEM;
+
+	q->read_buf->memory = V4L2_MEMORY_USERPTR;
+	q->read_buf->baddr  = (unsigned long)data;
+	q->read_buf->bsize  = count;
+
+	field = videobuf_next_field(q);
+	retval = q->ops->buf_prepare(q,q->read_buf,field);
+	if (0 != retval)
+		goto done;
+
+	/* start capture & wait */
+	if (q->irqlock)
+		spin_lock_irqsave(q->irqlock,flags);
+	q->ops->buf_queue(q,q->read_buf);
+	if (q->irqlock)
+		spin_unlock_irqrestore(q->irqlock,flags);
+	retval = videobuf_waiton(q->read_buf,0,0);
+	if (0 == retval) {
+		CALL(q,sync,q,q->read_buf);
+		if (STATE_ERROR == q->read_buf->state)
+			retval = -EIO;
+		else
+			retval = q->read_buf->size;
+	}
+
+ done:
+	/* cleanup */
+	q->ops->buf_release(q,q->read_buf);
+	kfree(q->read_buf);
+	q->read_buf = NULL;
+	return retval;
+}
+
+ssize_t videobuf_read_one(struct videobuf_queue *q,
+			  char __user *data, size_t count, loff_t *ppos,
+			  int nonblocking)
+{
+	enum v4l2_field field;
+	unsigned long flags=0;
+	unsigned size, nbufs;
+	int retval;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	mutex_lock(&q->lock);
+
+	nbufs = 1; size = 0;
+	q->ops->buf_setup(q,&nbufs,&size);
+
+	if (NULL == q->read_buf  &&
+	    count >= size        &&
+	    !nonblocking) {
+		retval = videobuf_read_zerocopy(q,data,count,ppos);
+		if (retval >= 0  ||  retval == -EIO)
+			/* ok, all done */
+			goto done;
+		/* fallback to kernel bounce buffer on failures */
+	}
+
+	if (NULL == q->read_buf) {
+		/* need to capture a new frame */
+		retval = -ENOMEM;
+		q->read_buf = videobuf_alloc(q);
+
+		dprintk(1,"video alloc=0x%p\n", q->read_buf);
+		if (NULL == q->read_buf)
+			goto done;
+		q->read_buf->memory = V4L2_MEMORY_USERPTR;
+		q->read_buf->bsize = count; /* preferred size */
+		field = videobuf_next_field(q);
+		retval = q->ops->buf_prepare(q,q->read_buf,field);
+
+		if (0 != retval) {
+			kfree (q->read_buf);
+			q->read_buf = NULL;
+			goto done;
+		}
+		if (q->irqlock)
+			spin_lock_irqsave(q->irqlock,flags);
+
+		q->ops->buf_queue(q,q->read_buf);
+		if (q->irqlock)
+			spin_unlock_irqrestore(q->irqlock,flags);
+		q->read_off = 0;
+	}
+
+	/* wait until capture is done */
+	retval = videobuf_waiton(q->read_buf, nonblocking, 1);
+	if (0 != retval)
+		goto done;
+
+	CALL(q,sync,q,q->read_buf);
+
+	if (STATE_ERROR == q->read_buf->state) {
+		/* catch I/O errors */
+		q->ops->buf_release(q,q->read_buf);
+		kfree(q->read_buf);
+		q->read_buf = NULL;
+		retval = -EIO;
+		goto done;
+	}
+
+	/* Copy to userspace */
+	retval=CALL(q,copy_to_user,q,data,count,nonblocking);
+	if (retval<0)
+		goto done;
+
+	q->read_off += retval;
+	if (q->read_off == q->read_buf->size) {
+		/* all data copied, cleanup */
+		q->ops->buf_release(q,q->read_buf);
+		kfree(q->read_buf);
+		q->read_buf = NULL;
+	}
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+int videobuf_read_start(struct videobuf_queue *q)
+{
+	enum v4l2_field field;
+	unsigned long flags=0;
+	int count = 0, size = 0;
+	int err, i;
+
+	q->ops->buf_setup(q,&count,&size);
+	if (count < 2)
+		count = 2;
+	if (count > VIDEO_MAX_FRAME)
+		count = VIDEO_MAX_FRAME;
+	size = PAGE_ALIGN(size);
+
+	err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
+	if (err)
+		return err;
+
+	for (i = 0; i < count; i++) {
+		field = videobuf_next_field(q);
+		err = q->ops->buf_prepare(q,q->bufs[i],field);
+		if (err)
+			return err;
+		list_add_tail(&q->bufs[i]->stream, &q->stream);
+	}
+	if (q->irqlock)
+		spin_lock_irqsave(q->irqlock,flags);
+	for (i = 0; i < count; i++)
+		q->ops->buf_queue(q,q->bufs[i]);
+	if (q->irqlock)
+		spin_unlock_irqrestore(q->irqlock,flags);
+	q->reading = 1;
+	return 0;
+}
+
+void videobuf_read_stop(struct videobuf_queue *q)
+{
+	int i;
+
+	videobuf_queue_cancel(q);
+	videobuf_mmap_free(q);
+	INIT_LIST_HEAD(&q->stream);
+	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+		if (NULL == q->bufs[i])
+			continue;
+		kfree(q->bufs[i]);
+		q->bufs[i] = NULL;
+	}
+	q->read_buf = NULL;
+	q->reading  = 0;
+}
+
+ssize_t videobuf_read_stream(struct videobuf_queue *q,
+			     char __user *data, size_t count, loff_t *ppos,
+			     int vbihack, int nonblocking)
+{
+	int rc, retval;
+	unsigned long flags=0;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	dprintk(2,"%s\n",__FUNCTION__);
+	mutex_lock(&q->lock);
+	retval = -EBUSY;
+	if (q->streaming)
+		goto done;
+	if (!q->reading) {
+		retval = videobuf_read_start(q);
+		if (retval < 0)
+			goto done;
+	}
+
+	retval = 0;
+	while (count > 0) {
+		/* get / wait for data */
+		if (NULL == q->read_buf) {
+			q->read_buf = list_entry(q->stream.next,
+						 struct videobuf_buffer,
+						 stream);
+			list_del(&q->read_buf->stream);
+			q->read_off = 0;
+		}
+		rc = videobuf_waiton(q->read_buf, nonblocking, 1);
+		if (rc < 0) {
+			if (0 == retval)
+				retval = rc;
+			break;
+		}
+
+		if (q->read_buf->state == STATE_DONE) {
+			rc = CALL (q,copy_stream, q, data, count,
+					retval, vbihack, nonblocking);
+			if (rc < 0) {
+				retval = rc;
+				break;
+			}
+			retval      += rc;
+			count       -= rc;
+			q->read_off += rc;
+		} else {
+			/* some error */
+			q->read_off = q->read_buf->size;
+			if (0 == retval)
+				retval = -EIO;
+		}
+
+		/* requeue buffer when done with copying */
+		if (q->read_off == q->read_buf->size) {
+			list_add_tail(&q->read_buf->stream,
+				      &q->stream);
+			if (q->irqlock)
+				spin_lock_irqsave(q->irqlock,flags);
+			q->ops->buf_queue(q,q->read_buf);
+			if (q->irqlock)
+				spin_unlock_irqrestore(q->irqlock,flags);
+			q->read_buf = NULL;
+		}
+		if (retval < 0)
+			break;
+	}
+
+ done:
+	mutex_unlock(&q->lock);
+	return retval;
+}
+
+unsigned int videobuf_poll_stream(struct file *file,
+				  struct videobuf_queue *q,
+				  poll_table *wait)
+{
+	struct videobuf_buffer *buf = NULL;
+	unsigned int rc = 0;
+
+	mutex_lock(&q->lock);
+	if (q->streaming) {
+		if (!list_empty(&q->stream))
+			buf = list_entry(q->stream.next,
+					 struct videobuf_buffer, stream);
+	} else {
+		if (!q->reading)
+			videobuf_read_start(q);
+		if (!q->reading) {
+			rc = POLLERR;
+		} else if (NULL == q->read_buf) {
+			q->read_buf = list_entry(q->stream.next,
+						 struct videobuf_buffer,
+						 stream);
+			list_del(&q->read_buf->stream);
+			q->read_off = 0;
+		}
+		buf = q->read_buf;
+	}
+	if (!buf)
+		rc = POLLERR;
+
+	if (0 == rc) {
+		poll_wait(file, &buf->done, wait);
+		if (buf->state == STATE_DONE ||
+		    buf->state == STATE_ERROR)
+			rc = POLLIN|POLLRDNORM;
+	}
+	mutex_unlock(&q->lock);
+	return rc;
+}
+
+int videobuf_mmap_setup(struct videobuf_queue *q,
+			unsigned int bcount, unsigned int bsize,
+			enum v4l2_memory memory)
+{
+	unsigned int i;
+	int err;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	err = videobuf_mmap_free(q);
+	if (0 != err)
+		return err;
+
+	/* Allocate and initialize buffers */
+	for (i = 0; i < bcount; i++) {
+		q->bufs[i] = videobuf_alloc(q);
+
+		q->bufs[i]->i      = i;
+		q->bufs[i]->input  = UNSET;
+		q->bufs[i]->memory = memory;
+		q->bufs[i]->bsize  = bsize;
+		switch (memory) {
+		case V4L2_MEMORY_MMAP:
+			q->bufs[i]->boff  = bsize * i;
+			break;
+		case V4L2_MEMORY_USERPTR:
+		case V4L2_MEMORY_OVERLAY:
+			/* nothing */
+			break;
+		}
+	}
+
+	dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
+		bcount,bsize);
+
+	return 0;
+}
+
+int videobuf_mmap_free(struct videobuf_queue *q)
+{
+	int i;
+	int rc;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	rc  = CALL(q,mmap_free,q);
+	if (rc<0)
+		return rc;
+
+	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+		if (NULL == q->bufs[i])
+			continue;
+		q->ops->buf_release(q,q->bufs[i]);
+		kfree(q->bufs[i]);
+		q->bufs[i] = NULL;
+	}
+
+	return rc;
+}
+
+int videobuf_mmap_mapper(struct videobuf_queue *q,
+			 struct vm_area_struct *vma)
+{
+	int retval;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	mutex_lock(&q->lock);
+	retval=CALL(q,mmap_mapper,q,vma);
+	mutex_unlock(&q->lock);
+
+	return retval;
+}
+
+#ifdef CONFIG_VIDEO_V4L1_COMPAT
+int videobuf_cgmbuf(struct videobuf_queue *q,
+		    struct video_mbuf *mbuf, int count)
+{
+	struct v4l2_requestbuffers req;
+	int rc,i;
+
+	MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
+
+	memset(&req,0,sizeof(req));
+	req.type   = q->type;
+	req.count  = count;
+	req.memory = V4L2_MEMORY_MMAP;
+	rc = videobuf_reqbufs(q,&req);
+	if (rc < 0)
+		return rc;
+
+	mbuf->frames = req.count;
+	mbuf->size   = 0;
+	for (i = 0; i < mbuf->frames; i++) {
+		mbuf->offsets[i]  = q->bufs[i]->boff;
+		mbuf->size       += q->bufs[i]->bsize;
+	}
+
+	return 0;
+}
+#endif
+
+/* --------------------------------------------------------------------- */
+
+EXPORT_SYMBOL_GPL(videobuf_waiton);
+EXPORT_SYMBOL_GPL(videobuf_iolock);
+
+EXPORT_SYMBOL_GPL(videobuf_alloc);
+
+EXPORT_SYMBOL_GPL(videobuf_queue_init);
+EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
+EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
+
+EXPORT_SYMBOL_GPL(videobuf_next_field);
+EXPORT_SYMBOL_GPL(videobuf_reqbufs);
+EXPORT_SYMBOL_GPL(videobuf_querybuf);
+EXPORT_SYMBOL_GPL(videobuf_qbuf);
+EXPORT_SYMBOL_GPL(videobuf_dqbuf);
+EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
+EXPORT_SYMBOL_GPL(videobuf_streamon);
+EXPORT_SYMBOL_GPL(videobuf_streamoff);
+
+EXPORT_SYMBOL_GPL(videobuf_read_start);
+EXPORT_SYMBOL_GPL(videobuf_read_stop);
+EXPORT_SYMBOL_GPL(videobuf_read_stream);
+EXPORT_SYMBOL_GPL(videobuf_read_one);
+EXPORT_SYMBOL_GPL(videobuf_poll_stream);
+
+EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
+EXPORT_SYMBOL_GPL(videobuf_mmap_free);
+EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */