drm/amd/display: Add dynamic link encoder selection.

[Why]
Some display endpoints may be programmably mapped to compatible link
encoders. The assignment of link encoders to links has to be dynamic to
accommodate the increased flexibility in comparison to conventional
display endpoints.

[How]
- Add link encoder assignment tracking variables.
- Execute link encoder assignment algorithm before enabling link and
release link encoders from links once they are disabled.

Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h b/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
index 7f5acd8fb918..80bc99500645 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
@@ -187,4 +187,17 @@ struct link_encoder_funcs {
 		struct link_encoder *enc);
 };
 
+/*
+ * Used to track assignments of links (display endpoints) to link encoders.
+ *
+ * Entry in link_enc_assignments table in struct resource_context.
+ * Entries only marked valid once encoder assigned to a link and invalidated once unassigned.
+ * Uses engine ID as identifier since PHY ID not relevant for USB4 DPIA endpoint.
+ */
+struct link_enc_assignment {
+	bool valid;
+	struct display_endpoint_id ep_id;
+	enum engine_id eng_id;
+};
+
 #endif /* LINK_ENCODER_H_ */