drm/amd/display: fix up reference clock abstractions

[why]
"reference clock" is a very overloaded variable in DC and causes confusion
as there are multiple sources of reference clock, which may be different values
incorrect input values to DML will cause DCHUB to be programmed improperly
and lead to hard to debug underflow issues

[how]
instead of using ref clock everywhere, specify WHICH ref clock:
- xtalin
- dccg refclk
- dchub refclk

these are all distinct values which may not be equal

Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 144440203316..79e760ac3600 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -31,6 +31,8 @@
 #include "opp.h"
 #include "timing_generator.h"
 #include "transform.h"
+#include "dccg.h"
+#include "dchubbub.h"
 #include "dpp.h"
 #include "core_types.h"
 #include "set_mode_types.h"
@@ -163,7 +165,28 @@ struct resource_pool *dc_create_resource_pool(
 
 		if (dc->ctx->dc_bios->funcs->get_firmware_info(
 				dc->ctx->dc_bios, &fw_info) == BP_RESULT_OK) {
-				res_pool->ref_clock_inKhz = fw_info.pll_info.crystal_frequency;
+				res_pool->ref_clocks.xtalin_clock_inKhz = fw_info.pll_info.crystal_frequency;
+
+				if (IS_FPGA_MAXIMUS_DC(dc->ctx->dce_environment)) {
+					// On FPGA these dividers are currently not configured by GDB
+					res_pool->ref_clocks.dccg_ref_clock_inKhz = res_pool->ref_clocks.xtalin_clock_inKhz;
+					res_pool->ref_clocks.dchub_ref_clock_inKhz = res_pool->ref_clocks.xtalin_clock_inKhz;
+				} else if (res_pool->dccg && res_pool->hubbub) {
+					// If DCCG reference frequency cannot be determined (usually means not set to xtalin) then this is a critical error
+					// as this value must be known for DCHUB programming
+					(res_pool->dccg->funcs->get_dccg_ref_freq)(res_pool->dccg,
+							fw_info.pll_info.crystal_frequency,
+							&res_pool->ref_clocks.dccg_ref_clock_inKhz);
+
+					// Similarly, if DCHUB reference frequency cannot be determined, then it is also a critical error
+					(res_pool->hubbub->funcs->get_dchub_ref_freq)(res_pool->hubbub,
+							res_pool->ref_clocks.dccg_ref_clock_inKhz,
+							&res_pool->ref_clocks.dchub_ref_clock_inKhz);
+				} else {
+					// Not all ASICs have DCCG sw component
+					res_pool->ref_clocks.dccg_ref_clock_inKhz = res_pool->ref_clocks.xtalin_clock_inKhz;
+					res_pool->ref_clocks.dchub_ref_clock_inKhz = res_pool->ref_clocks.xtalin_clock_inKhz;
+				}
 			} else
 				ASSERT_CRITICAL(false);
 	}