diff options
| -rw-r--r-- | include/media/videobuf2-v4l2.h | 52 |
1 files changed, 33 insertions, 19 deletions
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index 01b1b71fc6fd..611d4f330a4c 100644 --- a/include/media/videobuf2-v4l2.h +++ b/include/media/videobuf2-v4l2.h @@ -25,11 +25,13 @@ /** * struct vb2_v4l2_buffer - video buffer information for v4l2 + * * @vb2_buf: video buffer 2 * @flags: buffer informational flags * @field: enum v4l2_field; field order of the image in the buffer * @timecode: frame timecode * @sequence: sequence count of this frame + * * Should contain enough information to be able to cover all the fields * of struct v4l2_buffer at videodev2.h */ @@ -53,6 +55,7 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies * the memory and type values. + * * @q: videobuf2 queue * @req: struct passed from userspace to vidioc_reqbufs handler * in driver @@ -62,6 +65,7 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req); /** * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies * the memory and type values. + * * @q: videobuf2 queue * @create: creation parameters, passed from userspace to vidioc_create_bufs * handler in driver @@ -70,15 +74,17 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); /** * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel + * * @q: videobuf2 queue * @b: buffer structure passed from userspace to vidioc_prepare_buf * handler in driver * * Should be called from vidioc_prepare_buf ioctl handler of a driver. * This function: - * 1) verifies the passed buffer, - * 2) calls buf_prepare callback in the driver (if provided), in which - * driver-specific buffer initialization can be performed, + * + * #) verifies the passed buffer, + * #) calls buf_prepare callback in the driver (if provided), in which + * driver-specific buffer initialization can be performed. * * The return values from this function are intended to be directly returned * from vidioc_prepare_buf handler in driver. @@ -88,53 +94,57 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_qbuf() - Queue a buffer from userspace * @q: videobuf2 queue - * @b: buffer structure passed from userspace to vidioc_qbuf handler + * @b: buffer structure passed from userspace to VIDIOC_QBUF() handler * in driver * - * Should be called from vidioc_qbuf ioctl handler of a driver. + * Should be called from VIDIOC_QBUF() ioctl handler of a driver. + * * This function: - * 1) verifies the passed buffer, - * 2) if necessary, calls buf_prepare callback in the driver (if provided), in + * + * #) verifies the passed buffer, + * #) if necessary, calls buf_prepare callback in the driver (if provided), in * which driver-specific buffer initialization can be performed, - * 3) if streaming is on, queues the buffer in driver by the means of buf_queue + * #) if streaming is on, queues the buffer in driver by the means of buf_queue * callback for processing. * * The return values from this function are intended to be directly returned - * from vidioc_qbuf handler in driver. + * from VIDIOC_QBUF() handler in driver. */ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_expbuf() - Export a buffer as a file descriptor * @q: videobuf2 queue - * @eb: export buffer structure passed from userspace to vidioc_expbuf + * @eb: export buffer structure passed from userspace to VIDIOC_EXPBUF() * handler in driver * * The return values from this function are intended to be directly returned - * from vidioc_expbuf handler in driver. + * from VIDIOC_EXPBUF() handler in driver. */ int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb); /** * vb2_dqbuf() - Dequeue a buffer to the userspace * @q: videobuf2 queue - * @b: buffer structure passed from userspace to vidioc_dqbuf handler + * @b: buffer structure passed from userspace to VIDIOC_DQBUF() handler * in driver * @nonblocking: if true, this call will not sleep waiting for a buffer if no * buffers ready for dequeuing are present. Normally the driver * would be passing (file->f_flags & O_NONBLOCK) here * - * Should be called from vidioc_dqbuf ioctl handler of a driver. + * Should be called from VIDIOC_DQBUF() ioctl handler of a driver. + * * This function: - * 1) verifies the passed buffer, - * 2) calls buf_finish callback in the driver (if provided), in which + * + * #) verifies the passed buffer, + * #) calls buf_finish callback in the driver (if provided), in which * driver can perform any additional operations that may be required before * returning the buffer to userspace, such as cache sync, - * 3) the buffer struct members are filled with relevant information for + * #) the buffer struct members are filled with relevant information for * the userspace. * * The return values from this function are intended to be directly returned - * from vidioc_dqbuf handler in driver. + * from VIDIOC_DQBUF() handler in driver. */ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking); @@ -144,7 +154,9 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking); * @type: type argument passed from userspace to vidioc_streamon handler * * Should be called from vidioc_streamon handler of a driver. + * * This function: + * * 1) verifies current state * 2) passes any previously queued buffers to the driver and starts streaming * @@ -159,9 +171,11 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type); * @type: type argument passed from userspace to vidioc_streamoff handler * * Should be called from vidioc_streamoff handler of a driver. + * * This function: - * 1) verifies current state, - * 2) stop streaming and dequeues any queued buffers, including those previously + * + * #) verifies current state, + * #) stop streaming and dequeues any queued buffers, including those previously * passed to the driver (after waiting for the driver to finish). * * This call can be used for pausing playback. |