drm/amd/display: Implement DePQ for DCN1

[Why]
Need support for more color management in 10bit
surface.

[How]
Provide support for DePQ for 10bit surface
Signed-off-by: Reza Amini <Reza.Amini@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp_cm.c

@@ -628,6 +628,9 @@ void dpp1_set_degamma(
 	case IPP_DEGAMMA_MODE_HW_xvYCC:
 		REG_UPDATE(CM_DGAM_CONTROL, CM_DGAM_LUT_MODE, 2);
 			break;
+	case IPP_DEGAMMA_MODE_USER_PWL:
+		REG_UPDATE(CM_DGAM_CONTROL, CM_DGAM_LUT_MODE, 3);
+		break;
 	default:
 		BREAK_TO_DEBUGGER();
 		break;

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -1465,6 +1465,11 @@ bool dcn10_set_input_transfer_func(struct dc *dc, struct pipe_ctx *pipe_ctx,
 			dpp_base->funcs->dpp_set_degamma(dpp_base, IPP_DEGAMMA_MODE_BYPASS);
 			break;
 		case TRANSFER_FUNCTION_PQ:
+			dpp_base->funcs->dpp_set_degamma(dpp_base, IPP_DEGAMMA_MODE_USER_PWL);
+			cm_helper_translate_curve_to_degamma_hw_format(tf, &dpp_base->degamma_params);
+			dpp_base->funcs->dpp_program_degamma_pwl(dpp_base, &dpp_base->degamma_params);
+			result = true;
+			break;
 		default:
 			result = false;
 			break;

drivers/gpu/drm/amd/display/modules/color/color_gamma.c

@@ -154,6 +154,7 @@ static void compute_de_pq(struct fixed31_32 in_x, struct fixed31_32 *out_y)
 
 	struct fixed31_32 l_pow_m1;
 	struct fixed31_32 base, div;
+	struct fixed31_32 base2;
 
 
 	if (dc_fixpt_lt(in_x, dc_fixpt_zero))
@@ -163,13 +164,15 @@ static void compute_de_pq(struct fixed31_32 in_x, struct fixed31_32 *out_y)
 			dc_fixpt_div(dc_fixpt_one, m2));
 	base = dc_fixpt_sub(l_pow_m1, c1);
 
-	if (dc_fixpt_lt(base, dc_fixpt_zero))
-		base = dc_fixpt_zero;
-
 	div = dc_fixpt_sub(c2, dc_fixpt_mul(c3, l_pow_m1));
 
-	*out_y = dc_fixpt_pow(dc_fixpt_div(base, div),
-			dc_fixpt_div(dc_fixpt_one, m1));
+	base2 = dc_fixpt_div(base, div);
+	//avoid complex numbers
+	if (dc_fixpt_lt(base2, dc_fixpt_zero))
+		base2 = dc_fixpt_sub(dc_fixpt_zero, base2);
+
+
+	*out_y = dc_fixpt_pow(base2, dc_fixpt_div(dc_fixpt_one, m1));
 
 }
 
@@ -1998,10 +2001,28 @@ bool mod_color_calculate_degamma_params(struct dc_transfer_func *input_tf,
 	tf_pts->x_point_at_y1_green = 1;
 	tf_pts->x_point_at_y1_blue = 1;
 
+	if (input_tf->tf == TRANSFER_FUNCTION_PQ) {
+		/* just copy current rgb_regamma into  tf_pts */
+		struct pwl_float_data_ex *curvePt = curve;
+		int i = 0;
+
+		while (i <= MAX_HW_POINTS) {
+			tf_pts->red[i]   = curvePt->r;
+			tf_pts->green[i] = curvePt->g;
+			tf_pts->blue[i]  = curvePt->b;
+			++curvePt;
+			++i;
+		}
+	} else {
+		//clamps to 0-1
 		map_regamma_hw_to_x_user(ramp, coeff, rgb_user,
 				coordinates_x, axis_x, curve,
 				MAX_HW_POINTS, tf_pts,
 				mapUserRamp && ramp && ramp->type == GAMMA_RGB_256);
+	}
+
+
+
 	if (ramp->type == GAMMA_CUSTOM)
 		apply_lut_1d(ramp, MAX_HW_POINTS, tf_pts);