[PATCH v2 1/3] v4l: vsp1: extend VSP1 module API to allow DRM callbacks

[Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>]

To be able to perform page flips in DRM without flicker we need to be
able to notify the rcar-du module when the VSP has completed its
processing.

We must not have bidirectional dependencies on the two components to
maintain support for loadable modules, thus we extend the API to allow
a callback to be registered within the VSP DRM interface.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

---
v2:
 - vsp1_du_setup_lif() uses config structure to set callbacks
 - vsp1_du_pipeline_frame_end() moved to interrupt section
 - vsp1_du_pipeline_frame_end registered in vsp1_drm_init()
   meaning of any NULL values
 - removed unnecessary 'private data' variables

 drivers/media/platform/vsp1/vsp1_drm.c | 20 ++++++++++++++++++++
 drivers/media/platform/vsp1/vsp1_drm.h | 10 ++++++++++
 include/media/vsp1.h                   |  3 +++
 3 files changed, 33 insertions(+)

diff --git a/drivers/media/platform/vsp1/vsp1_drm.c b/drivers/media/platform/vsp1/vsp1_drm.c
index 7dce55043379..85e5ebca82a5 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/vsp1/vsp1_drm.c
@@ -36,6 +36,16 @@ void vsp1_drm_display_start(struct vsp1_device *vsp1)
 	vsp1_dlm_irq_display_start(vsp1->drm->pipe.output->dlm);
 }
 
+static void vsp1_du_pipeline_frame_end(struct vsp1_pipeline *pipe)
+{
+	struct vsp1_drm *drm = to_vsp1_drm(pipe);
+
+	if (drm->du_complete && drm->du_pending) {
+		drm->du_complete(drm->du_private);
+		drm->du_pending = false;
+	}
+}
+
 /* -----------------------------------------------------------------------------
  * DU Driver API
  */
@@ -95,6 +105,7 @@ int vsp1_du_setup_lif(struct device *dev, const struct vsp1_du_lif_config *cfg)
 		}
 
 		pipe->num_inputs = 0;
+		vsp1->drm->du_complete = NULL;
 
 		vsp1_dlm_reset(pipe->output->dlm);
 		vsp1_device_put(vsp1);
@@ -196,6 +207,13 @@ int vsp1_du_setup_lif(struct device *dev, const struct vsp1_du_lif_config *cfg)
 	if (ret < 0)
 		return ret;
 
+	/*
+	 * Register a callback to allow us to notify the DRM framework of frame
+	 * completion events.
+	 */
+	vsp1->drm->du_complete = cfg->callback;
+	vsp1->drm->du_private = cfg->callback_data;
+
 	ret = media_pipeline_start(&pipe->output->entity.subdev.entity,
 					  &pipe->pipe);
 	if (ret < 0) {
@@ -504,6 +522,7 @@ void vsp1_du_atomic_flush(struct device *dev)
 
 	vsp1_dl_list_commit(pipe->dl);
 	pipe->dl = NULL;
+	vsp1->drm->du_pending = true;
 
 	/* Start or stop the pipeline if needed. */
 	if (!vsp1->drm->num_inputs && pipe->num_inputs) {
@@ -597,6 +616,7 @@ int vsp1_drm_init(struct vsp1_device *vsp1)
 	pipe->lif = &vsp1->lif->entity;
 	pipe->output = vsp1->wpf[0];
 	pipe->output->pipe = pipe;
+	pipe->frame_end = vsp1_du_pipeline_frame_end;
 
 	return 0;
 }
diff --git a/drivers/media/platform/vsp1/vsp1_drm.h b/drivers/media/platform/vsp1/vsp1_drm.h
index 9e28ab9254ba..3a53e9a60c73 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.h
+++ b/drivers/media/platform/vsp1/vsp1_drm.h
@@ -33,8 +33,18 @@ struct vsp1_drm {
 		struct v4l2_rect compose;
 		unsigned int zpos;
 	} inputs[VSP1_MAX_RPF];
+
+	/* Frame syncronisation */
+	void (*du_complete)(void *);
+	void *du_private;
+	bool du_pending;
 };
 
+static inline struct vsp1_drm *to_vsp1_drm(struct vsp1_pipeline *pipe)
+{
+	return container_of(pipe, struct vsp1_drm, pipe);
+}
+
 int vsp1_drm_init(struct vsp1_device *vsp1);
 void vsp1_drm_cleanup(struct vsp1_device *vsp1);
 int vsp1_drm_create_links(struct vsp1_device *vsp1);
diff --git a/include/media/vsp1.h b/include/media/vsp1.h
index bfc701f04f3f..f6629f19f209 100644
--- a/include/media/vsp1.h
+++ b/include/media/vsp1.h
@@ -23,6 +23,9 @@ int vsp1_du_init(struct device *dev);
 struct vsp1_du_lif_config {
 	unsigned int width;
 	unsigned int height;
+
+	void (*callback)(void *);
+	void *callback_data;
 };
 
 int vsp1_du_setup_lif(struct device *dev, const struct vsp1_du_lif_config *cfg);
-- 
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