drm/komeda: Add slave pipeline support

One crtc can use two komeda_pipeline, and one works as master and as
slave. the slave pipeline doesn't have its own output and timing
ctrlr, but pre-composite the input layer data flow and then feed the
result to master. the pipeline configuration like:

slave-layer-0 \
...            slave->CU
slave-layer-4 /         \
                        \
master-layer-0 --------> master->CU -> ...
 ...                  /
master-layer-4 ------>

Since komeda Compiz doesn't output alpha, so the slave->CU result
only can be used as bottom input when blend it with master input data
flows.

Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
index f6a4a51cb5f7..2a67c8aa9fb6 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
@@ -452,6 +452,8 @@ komeda_pipeline_add(struct komeda_dev *mdev, size_t size,
 		    const struct komeda_pipeline_funcs *funcs);
 void komeda_pipeline_destroy(struct komeda_dev *mdev,
 			     struct komeda_pipeline *pipe);
+struct komeda_pipeline *
+komeda_pipeline_get_slave(struct komeda_pipeline *master);
 int komeda_assemble_pipelines(struct komeda_dev *mdev);
 struct komeda_component *
 komeda_pipeline_get_component(struct komeda_pipeline *pipe, int id);