drm/amd/display: add debug option for dramclk_change_latency in apu

[Why & How]
Support dramclk change latency change via debug option and add some
code isolation.
Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c

@@ -379,6 +379,11 @@ void dcn301_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
 	dcn3_01_soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
 	dc->dml.soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
 
+	if ((int)(dcn3_01_soc.dram_clock_change_latency_us * 1000)
+				!= dc->debug.dram_clock_change_latency_ns
+			&& dc->debug.dram_clock_change_latency_ns) {
+		dcn3_01_soc.dram_clock_change_latency_us = dc->debug.dram_clock_change_latency_ns / 1000.0;
+	}
 	dml_init_instance(&dc->dml, &dcn3_01_soc, &dcn3_01_ip, DML_PROJECT_DCN30);
 }
 

drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c

@@ -667,6 +667,12 @@ void dcn31_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params
 	dcn3_1_soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
 	dc->dml.soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
 
+	if ((int)(dcn3_1_soc.dram_clock_change_latency_us * 1000)
+				!= dc->debug.dram_clock_change_latency_ns
+			&& dc->debug.dram_clock_change_latency_ns) {
+		dcn3_1_soc.dram_clock_change_latency_us = dc->debug.dram_clock_change_latency_ns / 1000;
+	}
+
 	if (!IS_FPGA_MAXIMUS_DC(dc->ctx->dce_environment))
 		dml_init_instance(&dc->dml, &dcn3_1_soc, &dcn3_1_ip, DML_PROJECT_DCN31);
 	else
@@ -721,6 +727,12 @@ void dcn315_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
 	 */
 	dcn3_15_soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
 
+	if ((int)(dcn3_15_soc.dram_clock_change_latency_us * 1000)
+				!= dc->debug.dram_clock_change_latency_ns
+			&& dc->debug.dram_clock_change_latency_ns) {
+		dcn3_15_soc.dram_clock_change_latency_us = dc->debug.dram_clock_change_latency_ns / 1000;
+	}
+
 	if (!IS_FPGA_MAXIMUS_DC(dc->ctx->dce_environment))
 		dml_init_instance(&dc->dml, &dcn3_15_soc, &dcn3_15_ip, DML_PROJECT_DCN31);
 	else
@@ -813,6 +825,11 @@ void dcn316_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
 		dcn3_16_soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
 		dc->dml.soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
 	}
+	if ((int)(dcn3_16_soc.dram_clock_change_latency_us * 1000)
+				!= dc->debug.dram_clock_change_latency_ns
+			&& dc->debug.dram_clock_change_latency_ns) {
+		dcn3_16_soc.dram_clock_change_latency_us = dc->debug.dram_clock_change_latency_ns / 1000;
+	}
 
 	if (!IS_FPGA_MAXIMUS_DC(dc->ctx->dce_environment))
 		dml_init_instance(&dc->dml, &dcn3_16_soc, &dcn3_16_ip, DML_PROJECT_DCN31);

drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c

@@ -264,6 +264,11 @@ void dcn314_update_bw_bounding_box_fpu(struct dc *dc, struct clk_bw_params *bw_p
 		dc->dml.soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
 	}
 
+	if ((int)(dcn3_14_soc.dram_clock_change_latency_us * 1000)
+				!= dc->debug.dram_clock_change_latency_ns
+			&& dc->debug.dram_clock_change_latency_ns) {
+		dcn3_14_soc.dram_clock_change_latency_us = dc->debug.dram_clock_change_latency_ns / 1000;
+	}
 	if (!IS_FPGA_MAXIMUS_DC(dc->ctx->dce_environment))
 		dml_init_instance(&dc->dml, &dcn3_14_soc, &dcn3_14_ip, DML_PROJECT_DCN314);
 	else