drm/amd/display: add plane 3D LUT driver-specific properties

Add 3D LUT property for plane color transformations using a 3D lookup
table. 3D LUT allows for highly accurate and complex color
transformations and is suitable to adjust the balance between color
channels. It's also more complex to manage and require more
computational resources.

Since a 3D LUT has a limited number of entries in each dimension we want
to use them in an optimal fashion. This means using the 3D LUT in a
colorspace that is optimized for human vision, such as sRGB, PQ, or
another non-linear space. Therefore, userpace may need one 1D LUT
(shaper) before it to delinearize content and another 1D LUT after 3D
LUT (blend) to linearize content again for blending. The next patches
add these 1D LUTs to the plane color mgmt pipeline.

v3:
- improve commit message about 3D LUT
- describe the 3D LUT entries and size (Harry)

v4:
- advertise 3D LUT max size as the size of a single-dimension

v5:
- get lut3d blob correctly (Joshua)
- fix doc about 3d-lut dimension size (Sebastian)

Signed-off-by: Melissa Wen <mwen@igalia.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index d36d68d517a8..0f78024ac0e5 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -784,6 +784,11 @@ struct dm_plane_state {
 	 * TF is needed for any subsequent linear-to-non-linear transforms.
 	 */
 	__u64 hdr_mult;
+	/**
+	 * @lut3d: 3D lookup table blob. The blob (if not NULL) is an array of
+	 * &struct drm_color_lut.
+	 */
+	struct drm_property_blob *lut3d;
 };
 
 struct dm_crtc_state {
@@ -869,6 +874,10 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
 
 void amdgpu_dm_trigger_timing_sync(struct drm_device *dev);
 
+/* 3D LUT max size is 17x17x17 (4913 entries) */
+#define MAX_COLOR_3DLUT_SIZE 17
+#define MAX_COLOR_3DLUT_BITDEPTH 12
+/* 1D LUT size */
 #define MAX_COLOR_LUT_ENTRIES 4096
 /* Legacy gamm LUT users such as X doesn't like large LUT sizes */
 #define MAX_COLOR_LEGACY_LUT_ENTRIES 256