sdm: Add support for hybrid composition

- Add interface for hybrid composition where some part
  of layer is composed by blit engine and rest by SDE.
- Use BlitEngine interface for the blit composition
- Allocate blit target buffers in Commit and use Reconfig to
  re-validate the Hybrid composition
- Add C2D as a BlitEngine to get layers composed on the blit
  target.

Change-Id: I849da73055920ab13c1a260c9511478457e6894b

1 files changed, 3 insertions, 2 deletions

diff --git a/sdm/libs/core/strategy.cpp b/sdm/libs/core/strategy.cpp
index 183384ec6..f009d3afa 100644
--- a/sdm/libs/core/strategy.cpp
+++ b/sdm/libs/core/strategy.cpp
@@ -128,16 +128,17 @@ DisplayError Strategy::GetNextStrategy(StrategyConstraints *constraints) {
     return kErrorUndefined;
   }
 
-  // Mark all layers for GPU composition. Find GPU target buffer and store its index for
+  // Mark all application layers for GPU composition. Find GPU target buffer and store its index for
   // programming the hardware.
   LayerStack *layer_stack = hw_layers_info_->stack;
   uint32_t &hw_layer_count = hw_layers_info_->count;
   hw_layer_count = 0;
+
   for (uint32_t i = 0; i < layer_stack->layer_count; i++) {
     LayerComposition &composition = layer_stack->layers[i].composition;
     if (composition == kCompositionGPUTarget) {
       hw_layers_info_->index[hw_layer_count++] = i;
-    } else {
+    } else if (composition != kCompositionBlitTarget) {
       composition = kCompositionGPU;
     }
   }