videobuf-core.c

来自「linux 内核源代码」· C语言 代码 · 共 1,088 行 · 第 1/2 页

		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);

	if (b->memory == V4L2_MEMORY_MMAP)
		up_read(&current->mm->mmap_sem);

	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;
	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_entry(buf, &q->stream, 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;
}

/* Locking: Caller holds q->lock */
static int __videobuf_streamoff(struct videobuf_queue *q)
{
	if (!q->streaming)
		return -EINVAL;

	videobuf_queue_cancel(q);
	q->streaming = 0;

	return 0;
}

int videobuf_streamoff(struct videobuf_queue *q)
{
	int retval;

	mutex_lock(&q->lock);
	retval = __videobuf_streamoff(q);
	mutex_unlock(&q->lock);

	return retval;
}

/* Locking: Caller holds q->lock */
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,video_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;
}

/* Locking: Caller holds q->lock */
int __videobuf_read_start(struct videobuf_queue *q)
{
	enum v4l2_field field;
	unsigned long flags=0;
	unsigned 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 < 0)
		return err;

	count = 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;
}

static 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;
	
}

int videobuf_read_start(struct videobuf_queue *q)
{
	int rc;

	mutex_lock(&q->lock);
	rc = __videobuf_read_start(q);
	mutex_unlock(&q->lock);

	return rc;
}

void videobuf_read_stop(struct videobuf_queue *q)
{
	mutex_lock(&q->lock);
	__videobuf_read_stop(q);
	mutex_unlock(&q->lock);
}

void videobuf_stop(struct videobuf_queue *q)
{
	mutex_lock(&q->lock);

	if (q->streaming)
		__videobuf_streamoff(q);

	if (q->reading)
		__videobuf_read_stop(q);

	mutex_unlock(&q->lock);
}


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 + retval, 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_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;
}
EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
#endif

/* --------------------------------------------------------------------- */

EXPORT_SYMBOL_GPL(videobuf_waiton);
EXPORT_SYMBOL_GPL(videobuf_iolock);

EXPORT_SYMBOL_GPL(videobuf_alloc);

EXPORT_SYMBOL_GPL(videobuf_queue_core_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_streamon);
EXPORT_SYMBOL_GPL(videobuf_streamoff);

EXPORT_SYMBOL_GPL(videobuf_read_start);
EXPORT_SYMBOL_GPL(videobuf_read_stop);
EXPORT_SYMBOL_GPL(videobuf_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:
 */