drm/amd/display: Cleanup DML DSC input bpc validation

[Why & How]
Pipe input DSC bpc has a type mismatch with maximum DSC
input bpc - align the maximum with the pipe input type,
unsigned integer.

When checking the type we shoudl also check for an
implicit value of 0 and align with what the spreadsheet
does - default to max.

Rename output_bpc to dsc_input_bpc to reflect what the
field is actually used for.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -2216,7 +2216,7 @@ int dcn20_populate_dml_pipes_from_context(
 			pipes[pipe_cnt].dout.output_bpp = res_ctx->pipe_ctx[i].stream->timing.dsc_cfg.bits_per_pixel / 16.0;
 
 		/* todo: default max for now, until there is logic reflecting this in dc*/
-		pipes[pipe_cnt].dout.output_bpc = 12;
+		pipes[pipe_cnt].dout.dsc_input_bpc = 12;
 		/*fill up the audio sample rate (unit in kHz)*/
 		get_audio_check(&res_ctx->pipe_ctx[i].stream->audio_info, &aud_check);
 		pipes[pipe_cnt].dout.max_audio_sample_rate = aud_check.max_audiosample_rate / 1000;

drivers/gpu/drm/amd/display/dc/dml/display_mode_lib.c

@@ -226,7 +226,7 @@ void dml_log_pipe_params(
 		dml_print("DML PARAMS: PIPE [%d] DISPLAY OUTPUT PARAMS:\n", i);
 		dml_print("DML PARAMS:     output_type                = %d\n", dout->output_type);
 		dml_print("DML PARAMS:     output_format              = %d\n", dout->output_format);
-		dml_print("DML PARAMS:     output_bpc                 = %d\n", dout->output_bpc);
+		dml_print("DML PARAMS:     dsc_input_bpc              = %d\n", dout->dsc_input_bpc);
 		dml_print("DML PARAMS:     output_bpp                 = %3.4f\n", dout->output_bpp);
 		dml_print("DML PARAMS:     dp_lanes                   = %d\n", dout->dp_lanes);
 		dml_print("DML PARAMS:     dsc_enable                 = %d\n", dout->dsc_enable);

drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h

@@ -164,7 +164,7 @@ struct _vcs_dpi_ip_params_st {
 	double writeback_max_vscl_ratio;
 	double writeback_min_hscl_ratio;
 	double writeback_min_vscl_ratio;
-	double maximum_dsc_bits_per_component;
+	unsigned int maximum_dsc_bits_per_component;
 	unsigned int writeback_max_hscl_taps;
 	unsigned int writeback_max_vscl_taps;
 	unsigned int writeback_line_buffer_luma_buffer_size;
@@ -292,10 +292,10 @@ struct writeback_st {
 struct _vcs_dpi_display_output_params_st {
 	int dp_lanes;
 	double output_bpp;
+	unsigned int dsc_input_bpc;
 	int dsc_enable;
 	int wb_enable;
 	int num_active_wb;
-	int output_bpc;
 	int output_type;
 	int is_virtual;
 	int output_format;

drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c

@@ -471,7 +471,13 @@ static void fetch_pipe_params(struct display_mode_lib *mode_lib)
 		mode_lib->vba.DSCEnable[mode_lib->vba.NumberOfActivePlanes] = dout->dsc_enable;
 		mode_lib->vba.NumberOfDSCSlices[mode_lib->vba.NumberOfActivePlanes] =
 				dout->dsc_slices;
-		mode_lib->vba.DSCInputBitPerComponent[mode_lib->vba.NumberOfActivePlanes] = dout->output_bpc;
+		if (!dout->dsc_input_bpc) {
+			mode_lib->vba.DSCInputBitPerComponent[mode_lib->vba.NumberOfActivePlanes] =
+				ip->maximum_dsc_bits_per_component;
+		} else {
+			mode_lib->vba.DSCInputBitPerComponent[mode_lib->vba.NumberOfActivePlanes] =
+				dout->dsc_input_bpc;
+		}
 		mode_lib->vba.WritebackEnable[mode_lib->vba.NumberOfActivePlanes] = dout->wb_enable;
 		mode_lib->vba.ActiveWritebacksPerPlane[mode_lib->vba.NumberOfActivePlanes] =
 				dout->num_active_wb;