diff options
Diffstat (limited to 'include/media/videobuf2-v4l2.h')
| -rw-r--r-- | include/media/videobuf2-v4l2.h | 81 |
1 files changed, 70 insertions, 11 deletions
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index 59bf33a12648..5a845887850b 100644 --- a/include/media/videobuf2-v4l2.h +++ b/include/media/videobuf2-v4l2.h @@ -23,6 +23,8 @@ #error VB2_MAX_PLANES != VIDEO_MAX_PLANES #endif +struct video_device; + /** * struct vb2_v4l2_buffer - video buffer information for v4l2. * @@ -61,20 +63,14 @@ struct vb2_v4l2_buffer { container_of(vb, struct vb2_v4l2_buffer, vb2_buf) /** - * vb2_find_timestamp() - Find buffer with given timestamp in the queue + * vb2_find_buffer() - Find a buffer with given timestamp * * @q: pointer to &struct vb2_queue with videobuf2 queue. * @timestamp: the timestamp to find. - * @start_idx: the start index (usually 0) in the buffer array to start - * searching from. Note that there may be multiple buffers - * with the same timestamp value, so you can restart the search - * by setting @start_idx to the previously found index + 1. * - * Returns the buffer index of the buffer with the given @timestamp, or - * -1 if no buffer with @timestamp was found. + * Returns the buffer with the given @timestamp, or NULL if not found. */ -int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp, - unsigned int start_idx); +struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp); int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b); @@ -237,6 +233,19 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type); int __must_check vb2_queue_init(struct vb2_queue *q); /** + * vb2_queue_init_name() - initialize a videobuf2 queue with a name + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @name: the queue name + * + * This function initializes the vb2_queue exactly like vb2_queue_init(), + * and additionally sets the queue name. The queue name is used for logging + * purpose, and should uniquely identify the queue within the context of the + * device it belongs to. This is useful to attribute kernel log messages to the + * right queue for m2m devices or other devices that handle multiple queues. + */ +int __must_check vb2_queue_init_name(struct vb2_queue *q, const char *name); + +/** * vb2_queue_release() - stop streaming, release the queue and free memory * @q: pointer to &struct vb2_queue with videobuf2 queue. * @@ -247,6 +256,22 @@ int __must_check vb2_queue_init(struct vb2_queue *q); 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. * @file: file argument passed to the poll file operation handler @@ -271,10 +296,29 @@ __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); * The following functions are not part of the vb2 core API, but are simple * helper functions that you can use in your struct v4l2_file_operations, * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock - * or video_device->lock is set, and they will set and test vb2_queue->owner - * to check if the calling filehandle is permitted to do the queuing operation. + * or video_device->lock is set, and they will set and test the queue owner + * (vb2_queue->owner) to check if the calling filehandle is permitted to do the + * queuing operation. */ +/** + * vb2_queue_is_busy() - check if the queue is busy + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @file: file through which the vb2 queue access is performed + * + * The queue is considered busy if it has an owner and the owner is not the + * @file. + * + * Queue ownership is acquired and checked by some of the v4l2_ioctl_ops helpers + * below. Drivers can also use this function directly when they need to + * open-code ioctl handlers, for instance to add additional checks between the + * queue ownership test and the call to the corresponding vb2 operation. + */ +static inline bool vb2_queue_is_busy(struct vb2_queue *q, struct file *file) +{ + return q->owner && q->owner != file->private_data; +} + /* struct v4l2_ioctl_ops helpers */ int vb2_ioctl_reqbufs(struct file *file, void *priv, @@ -307,6 +351,21 @@ unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, #endif /** + * vb2_video_unregister_device - unregister the video device and release queue + * + * @vdev: pointer to &struct video_device + * + * If the driver uses vb2_fop_release()/_vb2_fop_release(), then it should use + * vb2_video_unregister_device() instead of video_unregister_device(). + * + * This function will call video_unregister_device() and then release the + * vb2_queue if streaming is in progress. This will stop streaming and + * this will simplify the unbind sequence since after this call all subdevs + * will have stopped streaming as well. + */ +void vb2_video_unregister_device(struct video_device *vdev); + +/** * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue * * @vq: pointer to &struct vb2_queue |