omap3isp: Add transparent buffer pools support

Buffers pools can be inserted in a pipeline between a video capture
device and a video output device. They will automatically relay buffers
from the capture device to the output device in a transparent way.

One use case of buffer pools is to work around hardware issues. When the
CCDC is directly connected to the preview engine, any ESD-induce noise
on the HS or VS signals will make the preview engine loose sync, is it
only relies on line counts. Introducing a buffer pool between the CCDC
and preview engine work around the issue.

This patch only implements buffer pool creation during pipeline build.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/isp/omap3isp-priv.h b/isp/omap3isp-priv.h
index b4d2114..9706ba8 100644
--- a/isp/omap3isp-priv.h
+++ b/isp/omap3isp-priv.h
@@ -40,6 +40,7 @@ struct omap3_isp_pad {
 
 enum omap3_isp_entity_type {
 	OMAP3_ISP_ENTITY_ENTITY,
+	OMAP3_ISP_ENTITY_POOL,
 	OMAP3_ISP_ENTITY_VIDEO,
 };
 
@@ -82,14 +83,34 @@ struct omap3_isp_video {
 #define to_omap3_isp_video(e)	container_of(e, struct omap3_isp_video, entity)
 
 /*
+ * struct omap3_isp_pool - OMAP3 buffers pool
+ * @entity: OMAP3 entity
+ * @list: Pools list
+ * @input: Capture video device
+ * @output: Output video device
+ * @pool: Buffers pool
+ */
+struct omap3_isp_pool {
+	struct omap3_isp_entity entity;
+	struct list_entry list;
+	struct omap3_isp_video *input;
+	struct omap3_isp_video *output;
+	struct v4l2_buffers_pool *pool;
+};
+
+#define to_omap3_isp_pool(e)	container_of(e, struct omap3_isp_pool, entity)
+
+/*
  * struct omap3_isp_pipeline - OMAP3 pipeline
  * @entitites: Entities in the pipeline
  * @scaler: Whether scaling should be performed on the ISP or the sensor
+ * @pools: Pools in the pipeline
  * @output: Video device at the output of the pipeline
  */
 struct omap3_isp_pipeline {
 	struct list_entry entities;
 	enum omap3_isp_scaler scaler;
+	struct list_entry pools;
 	struct omap3_isp_video *output;
 };