Add v4l2_subdev_get_frame_interval()

Add function to get frame interval.

Signed-off-by: Todor Tomov <ttomov@mm-sol.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/subdev.c b/subdev.c
index 3a8e82a..3960d05 100644
--- a/subdev.c
+++ b/subdev.c
@@ -145,6 +145,26 @@ int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
 	return 0;
 }
 
+int v4l2_subdev_get_frame_interval(struct media_entity *entity,
+				   struct v4l2_fract *interval)
+{
+	struct v4l2_subdev_frame_interval ival;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&ival, 0, sizeof(ival));
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_G_FRAME_INTERVAL, &ival);
+	if (ret < 0)
+		return -errno;
+
+	*interval = ival.interval;
+	return 0;
+}
+
 int v4l2_subdev_set_frame_interval(struct media_entity *entity,
 				   struct v4l2_fract *interval)
 {
diff --git a/subdev.h b/subdev.h
index 9451b12..b5772e0 100644
--- a/subdev.h
+++ b/subdev.h
@@ -125,6 +125,23 @@ int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
 	unsigned int pad, enum v4l2_subdev_format_whence which);
 
 /**
+ * @brief Retrieve the frame interval on a sub-device.
+ * @param entity - subdev-device media entity.
+ * @param interval - frame interval to be filled.
+ *
+ * Retrieve the current frame interval on subdev @a entity and store it in the
+ * @a interval structure.
+ *
+ * Frame interval retrieving is usually supported only on devices at the
+ * beginning of video pipelines, such as sensors.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+
+int v4l2_subdev_get_frame_interval(struct media_entity *entity,
+	struct v4l2_fract *interval);
+
+/**
  * @brief Set the frame interval on a sub-device.
  * @param entity - subdev-device media entity.
  * @param interval - frame interval.