[RFC PATCH 11/40] drm/amd/display: add plane degamma TF driver-private property

[Melissa Wen]

From: Joshua Ashton <joshua@xxxxxxxxx>

Allow userspace to tell the kernel driver the input space and,
therefore, uses correct predefined transfer function (TF) to delinearize
content with or without LUT (using hardcoded curve caps).

Signed-off-by: Joshua Ashton <joshua@xxxxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c   |  9 ++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h      |  5 ++++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 +++++
 .../amd/display/amdgpu_dm/amdgpu_dm_plane.c   | 28 +++++++++++++++++++
 4 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 996c9c3fd471..24595906dab1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -1317,6 +1317,15 @@ amdgpu_display_create_color_properties(struct amdgpu_device *adev)
 		return -ENOMEM;
 	adev->mode_info.plane_degamma_lut_size_property = prop;
 
+	prop = drm_property_create_enum(adev_to_drm(adev),
+					DRM_MODE_PROP_ENUM,
+					"AMD_PLANE_DEGAMMA_TF",
+					drm_transfer_function_enum_list,
+					ARRAY_SIZE(drm_transfer_function_enum_list));
+	if (!prop)
+		return -ENOMEM;
+	adev->mode_info.plane_degamma_tf_property = prop;
+
 	return 0;
 }
 #endif
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
index d4e609a8b67e..ab9ce6f26c90 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -382,6 +382,11 @@ struct amdgpu_mode_info {
 	 * size of degamma LUT as supported by the driver (read-only).
 	 */
 	struct drm_property *plane_degamma_lut_size_property;
+	/**
+	 * @plane_degamma_tf_property: Predefined transfer function to
+	 * linearize content with or without LUT.
+	 */
+	struct drm_property *plane_degamma_tf_property;
 #endif
 };
 
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 b1d0c65d821d..005632c1c9ec 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -729,6 +729,13 @@ struct dm_plane_state {
 	 * The blob (if not NULL) is an array of &struct drm_color_lut.
 	 */
 	struct drm_property_blob *degamma_lut;
+	/**
+	 * @degamma_tf:
+	 *
+	 * Predefined transfer function to tell DC driver the input space to
+	 * linearize.
+	 */
+	enum drm_transfer_function degamma_tf;
 #endif
 };
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 7b9d62c70b30..5b458cc0781c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -1319,6 +1319,11 @@ static void dm_drm_plane_reset(struct drm_plane *plane)
 
 	if (amdgpu_state)
 		__drm_atomic_helper_plane_reset(plane, &amdgpu_state->base);
+
+#ifdef CONFIG_STEAM_DECK
+	if (amdgpu_state)
+		amdgpu_state->degamma_tf = DRM_TRANSFER_FUNCTION_DEFAULT;
+#endif
 }
 
 static struct drm_plane_state *
@@ -1450,6 +1455,19 @@ amdgpu_dm_replace_property_blob_from_id(struct drm_device *dev,
 	return 0;
 }
 
+static const struct drm_prop_enum_list drm_transfer_function_enum_list[] = {
+	{ DRM_TRANSFER_FUNCTION_DEFAULT, "Default" },
+	{ DRM_TRANSFER_FUNCTION_SRGB, "sRGB" },
+	{ DRM_TRANSFER_FUNCTION_BT709, "BT.709" },
+	{ DRM_TRANSFER_FUNCTION_PQ, "PQ (Perceptual Quantizer)" },
+	{ DRM_TRANSFER_FUNCTION_LINEAR, "Linear" },
+	{ DRM_TRANSFER_FUNCTION_UNITY, "Unity" },
+	{ DRM_TRANSFER_FUNCTION_HLG, "HLG (Hybrid Log Gamma)" },
+	{ DRM_TRANSFER_FUNCTION_GAMMA22, "Gamma 2.2" },
+	{ DRM_TRANSFER_FUNCTION_GAMMA24, "Gamma 2.4" },
+	{ DRM_TRANSFER_FUNCTION_GAMMA26, "Gamma 2.6" },
+};
+
 static void
 dm_plane_attach_color_mgmt_properties(struct amdgpu_display_manager *dm,
 				      struct drm_plane *plane)
@@ -1460,6 +1478,9 @@ dm_plane_attach_color_mgmt_properties(struct amdgpu_display_manager *dm,
 		drm_object_attach_property(&plane->base,
 					   dm->adev->mode_info.plane_degamma_lut_size_property,
 					   MAX_COLOR_LUT_ENTRIES);
+		drm_object_attach_property(&plane->base,
+					   dm->adev->mode_info.plane_degamma_tf_property,
+					   DRM_TRANSFER_FUNCTION_DEFAULT);
 	}
 }
 
@@ -1481,6 +1502,11 @@ dm_atomic_plane_set_property(struct drm_plane *plane,
 					&replaced);
 		dm_plane_state->base.color_mgmt_changed |= replaced;
 		return ret;
+	} else if (property == adev->mode_info.plane_degamma_tf_property) {
+		if (dm_plane_state->degamma_tf != val) {
+			dm_plane_state->degamma_tf = val;
+			dm_plane_state->base.color_mgmt_changed = 1;
+		}
 	} else {
 		drm_dbg_atomic(plane->dev,
 			       "[PLANE:%d:%s] unknown property [PROP:%d:%s]]\n",
@@ -1505,6 +1531,8 @@ dm_atomic_plane_get_property(struct drm_plane *plane,
 	if (property == adev->mode_info.plane_degamma_lut_property) {
 		*val = (dm_plane_state->degamma_lut) ?
 			dm_plane_state->degamma_lut->base.id : 0;
+	} else if (property == adev->mode_info.plane_degamma_tf_property) {
+		*val = dm_plane_state->degamma_tf;
 	} else {
 		return -EINVAL;
 	}
-- 
2.39.2