[media] v4l: vsp1: Support multiple partitions per frame

Adapt vsp1_video_pipeline_run() such that it can iterate each partition
required for constructing this frame's display list chain in the event
that multiple display lists are required to process in hardware.

The first display list is held as the head list object, whilst any
following parition display lists are linked to the head by means of
vsp1_dl_list_add_chain().

Linking the chained display list headers to process using the auto start
mechanism of the hardware is performed during the vsp1_dl_list_commit().

Signed-off-by: Kieran Bingham <kieran+renesas@bingham.xyz>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 118 insertions, 3 deletions

diff --git a/drivers/media/platform/vsp1/vsp1_video.c b/drivers/media/platform/vsp1/vsp1_video.c
index b903cc5471e0..15d08cb50bd1 100644
--- a/drivers/media/platform/vsp1/vsp1_video.c
+++ b/drivers/media/platform/vsp1/vsp1_video.c
@@ -205,6 +205,74 @@ static void vsp1_video_pipeline_setup_partitions(struct vsp1_pipeline *pipe)
 	pipe->partitions = DIV_ROUND_UP(format->width, div_size);
 }
 
+/*
+ * vsp1_video_partition - Calculate the active partition output window
+ *
+ * @div_size: pre-determined maximum partition division size
+ * @index: partition index
+ *
+ * Returns a v4l2_rect describing the partition window.
+ */
+static struct v4l2_rect vsp1_video_partition(struct vsp1_pipeline *pipe,
+					     unsigned int div_size,
+					     unsigned int index)
+{
+	const struct v4l2_mbus_framefmt *format;
+	struct v4l2_rect partition;
+	unsigned int modulus;
+
+	format = vsp1_entity_get_pad_format(&pipe->output->entity,
+					    pipe->output->entity.config,
+					    RWPF_PAD_SOURCE);
+
+	/* A single partition simply processes the output size in full. */
+	if (pipe->partitions <= 1) {
+		partition.left = 0;
+		partition.top = 0;
+		partition.width = format->width;
+		partition.height = format->height;
+		return partition;
+	}
+
+	/* Initialise the partition with sane starting conditions. */
+	partition.left = index * div_size;
+	partition.top = 0;
+	partition.width = div_size;
+	partition.height = format->height;
+
+	modulus = format->width % div_size;
+
+	/* We need to prevent the last partition from being smaller than the
+	 * *minimum* width of the hardware capabilities.
+	 *
+	 * If the modulus is less than half of the partition size,
+	 * the penultimate partition is reduced to half, which is added
+	 * to the final partition: |1234|1234|1234|12|341|
+	 * to prevents this:       |1234|1234|1234|1234|1|.
+	 */
+	if (modulus) {
+		/* pipe->partitions is 1 based, whilst index is a 0 based index.
+		 * Normalise this locally.
+		 */
+		unsigned int partitions = pipe->partitions - 1;
+
+		if (modulus < div_size / 2) {
+			if (index == partitions - 1) {
+				/* Halve the penultimate partition. */
+				partition.width = div_size / 2;
+			} else if (index == partitions) {
+				/* Increase the final partition. */
+				partition.width = (div_size / 2) + modulus;
+				partition.left -= div_size / 2;
+			}
+		} else if (index == partitions) {
+			partition.width = modulus;
+		}
+	}
+
+	return partition;
+}
+
 /* -----------------------------------------------------------------------------
  * Pipeline Management
  */
@@ -280,22 +348,69 @@ static void vsp1_video_frame_end(struct vsp1_pipeline *pipe,
 	pipe->buffers_ready |= 1 << video->pipe_index;
 }
 
+static void vsp1_video_pipeline_run_partition(struct vsp1_pipeline *pipe,
+					      struct vsp1_dl_list *dl)
+{
+	struct vsp1_entity *entity;
+
+	pipe->partition = vsp1_video_partition(pipe, pipe->div_size,
+					       pipe->current_partition);
+
+	list_for_each_entry(entity, &pipe->entities, list_pipe) {
+		if (entity->ops->configure)
+			entity->ops->configure(entity, pipe, dl,
+					       VSP1_ENTITY_PARAMS_PARTITION);
+	}
+}
+
 static void vsp1_video_pipeline_run(struct vsp1_pipeline *pipe)
 {
+	struct vsp1_device *vsp1 = pipe->output->entity.vsp1;
 	struct vsp1_entity *entity;
 
 	if (!pipe->dl)
 		pipe->dl = vsp1_dl_list_get(pipe->output->dlm);
 
+	/* Start with the runtime parameters as the configure operation can
+	 * compute/cache information needed when configuring partitions. This
+	 * is the case with flipping in the WPF.
+	 */
 	list_for_each_entry(entity, &pipe->entities, list_pipe) {
-		if (entity->ops->configure) {
+		if (entity->ops->configure)
 			entity->ops->configure(entity, pipe, pipe->dl,
 					       VSP1_ENTITY_PARAMS_RUNTIME);
-			entity->ops->configure(entity, pipe, pipe->dl,
-					       VSP1_ENTITY_PARAMS_PARTITION);
+	}
+
+	/* Run the first partition */
+	pipe->current_partition = 0;
+	vsp1_video_pipeline_run_partition(pipe, pipe->dl);
+
+	/* Process consecutive partitions as necessary */
+	for (pipe->current_partition = 1;
+	     pipe->current_partition < pipe->partitions;
+	     pipe->current_partition++) {
+		struct vsp1_dl_list *dl;
+
+		/* Partition configuration operations will utilise
+		 * the pipe->current_partition variable to determine
+		 * the work they should complete.
+		 */
+		dl = vsp1_dl_list_get(pipe->output->dlm);
+
+		/* An incomplete chain will still function, but output only
+		 * the partitions that had a dl available. The frame end
+		 * interrupt will be marked on the last dl in the chain.
+		 */
+		if (!dl) {
+			dev_err(vsp1->dev, "Failed to obtain a dl list. Frame will be incomplete\n");
+			break;
 		}
+
+		vsp1_video_pipeline_run_partition(pipe, dl);
+		vsp1_dl_list_add_chain(pipe->dl, dl);
 	}
 
+	/* Complete, and commit the head display list. */
 	vsp1_dl_list_commit(pipe->dl);
 	pipe->dl = NULL;