drm/i915/color: Create a transfer function color pipeline

Add a color pipeline with three colorops in the sequence

1D LUT - 3x4 CTM - 1D LUT

This pipeline can be used to do any color space conversion or HDR
tone mapping

v2: Change namespace to drm_plane_colorop*
v3: Use simpler/pre-existing colorops for first iteration
v4:
- s/*_tf_*/*_color_* (Jani)
- Refactor to separate files (Jani)
- Add missing space in comment (Suraj)
- Consolidate patch that adds/attaches pipeline property
v5:
- Limit MAX_COLOR_PIPELINES to 2.(Suraj)
Increase it as and when we add more pipelines.
- Remove redundant initialization code (Suraj)
v6:
- Use drm_plane_create_color_pipeline_property() (Arun)
Now MAX_COLOR_PIPELINES is 1

Reviewed-by: Suraj Kandpal <[e-mail]>
Signed-off-by: Uma Shankar <[e-mail]>
Signed-off-by: Chaitanya Kumar Borah <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jani Nikula <[e-mail]>

drivers/gpu/drm/i915/Makefile

···
 	display/intel_cmtg.o \
 	display/intel_color.o \
 	display/intel_colorop.o \
+	display/intel_color_pipeline.o \
 	display/intel_combo_phy.o \
 	display/intel_connector.o \
 	display/intel_crtc.o \

drivers/gpu/drm/i915/display/intel_color_pipeline.c

···
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+#include "intel_colorop.h"
+#include "intel_color_pipeline.h"
+#include "intel_de.h"
+#include "intel_display_types.h"
+#include "skl_universal_plane.h"
+
+#define MAX_COLOR_PIPELINES 1
+#define PLANE_DEGAMMA_SIZE 128
+#define PLANE_GAMMA_SIZE 32
+
+static
+int _intel_color_pipeline_plane_init(struct drm_plane *plane, struct drm_prop_enum_list *list)
+{
+	struct intel_colorop *colorop;
+	struct drm_device *dev = plane->dev;
+	int ret;
+	struct drm_colorop *prev_op;
+
+	colorop = intel_colorop_create(INTEL_PLANE_CB_PRE_CSC_LUT);
+
+	ret = drm_plane_colorop_curve_1d_lut_init(dev, &colorop->base, plane,
+						  PLANE_DEGAMMA_SIZE,
+						  DRM_COLOROP_LUT1D_INTERPOLATION_LINEAR,
+						  DRM_COLOROP_FLAG_ALLOW_BYPASS);
+
+	if (ret)
+		return ret;
+
+	list->type = colorop->base.base.id;
+	list->name = kasprintf(GFP_KERNEL, "Color Pipeline %d", colorop->base.base.id);
+
+	/* TODO: handle failures and clean up */
+	prev_op = &colorop->base;
+
+	colorop = intel_colorop_create(INTEL_PLANE_CB_CSC);
+	ret = drm_plane_colorop_ctm_3x4_init(dev, &colorop->base, plane,
+					     DRM_COLOROP_FLAG_ALLOW_BYPASS);
+	if (ret)
+		return ret;
+
+	drm_colorop_set_next_property(prev_op, &colorop->base);
+	prev_op = &colorop->base;
+
+	colorop = intel_colorop_create(INTEL_PLANE_CB_POST_CSC_LUT);
+	ret = drm_plane_colorop_curve_1d_lut_init(dev, &colorop->base, plane,
+						  PLANE_GAMMA_SIZE,
+						  DRM_COLOROP_LUT1D_INTERPOLATION_LINEAR,
+						  DRM_COLOROP_FLAG_ALLOW_BYPASS);
+	if (ret)
+		return ret;
+
+	drm_colorop_set_next_property(prev_op, &colorop->base);
+
+	return 0;
+}
+
+int intel_color_pipeline_plane_init(struct drm_plane *plane)
+{
+	struct drm_device *dev = plane->dev;
+	struct intel_display *display = to_intel_display(dev);
+	struct drm_prop_enum_list pipelines[MAX_COLOR_PIPELINES];
+	int len = 0;
+	int ret;
+
+	/* Currently expose pipeline only for HDR planes */
+	if (!icl_is_hdr_plane(display, to_intel_plane(plane)->id))
+		return 0;
+
+	/* Add pipeline consisting of transfer functions */
+	ret = _intel_color_pipeline_plane_init(plane, &pipelines[len]);
+	if (ret)
+		return ret;
+	len++;
+
+	return drm_plane_create_color_pipeline_property(plane, pipelines, len);
+}

drivers/gpu/drm/i915/display/intel_color_pipeline.h

···
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef __INTEL_COLOR_PIPELINE_H__
+#define __INTEL_COLOR_PIPELINE_H__
+
+struct drm_plane;
+
+int intel_color_pipeline_plane_init(struct drm_plane *plane);
+
+#endif /* __INTEL_COLOR_PIPELINE_H__ */

drivers/gpu/drm/xe/Makefile

···
 	i915-display/intel_cmtg.o \
 	i915-display/intel_color.o \
 	i915-display/intel_colorop.o \
+	i915-display/intel_color_pipeline.o \
 	i915-display/intel_combo_phy.o \
 	i915-display/intel_connector.o \
 	i915-display/intel_crtc.o \