diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 7e96f67c60ba8635362df41f572895fe43ce6676..2988bb38ceb18e279091a94822368ef80426e293 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -939,6 +939,20 @@ void vb2_queue_release(struct vb2_queue *q) } EXPORT_SYMBOL_GPL(vb2_queue_release); +int vb2_queue_change_type(struct vb2_queue *q, unsigned int type) +{ + if (type == q->type) + return 0; + + if (vb2_is_busy(q)) + return -EBUSY; + + q->type = type; + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_queue_change_type); + __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) { struct video_device *vfd = video_devdata(file); diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index c203047eb83409afd712716d2a3ebf683fc8b1ae..b66585e304e26a0101658399dde52dc4d59200a9 100644 --- a/include/media/videobuf2-v4l2.h +++ b/include/media/videobuf2-v4l2.h @@ -261,6 +261,22 @@ int __must_check vb2_queue_init_name(struct vb2_queue *q, const char *name); */ void vb2_queue_release(struct vb2_queue *q); +/** + * vb2_queue_change_type() - change the type of an inactive vb2_queue + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @type: the type to change to (V4L2_BUF_TYPE_VIDEO_*) + * + * This function changes the type of the vb2_queue. This is only possible + * if the queue is not busy (i.e. no buffers have been allocated). + * + * vb2_queue_change_type() can be used to support multiple buffer types using + * the same queue. The driver can implement v4l2_ioctl_ops.vidioc_reqbufs and + * v4l2_ioctl_ops.vidioc_create_bufs functions and call vb2_queue_change_type() + * before calling vb2_ioctl_reqbufs() or vb2_ioctl_create_bufs(), and thus + * "lock" the buffer type until the buffers have been released. + */ +int vb2_queue_change_type(struct vb2_queue *q, unsigned int type); + /** * vb2_poll() - implements poll userspace operation * @q: pointer to &struct vb2_queue with videobuf2 queue.