[RFC PATCH 12/40] drm/amd/display: add plane HDR multiplier driver-private property

[Melissa Wen]

From: Joshua Ashton <joshua at froggi.es>

Multiplier to 'gain' the plane. When PQ is decoded using the fixed func
transfer function to the internal FP16 fb, 1.0 -> 80 nits (on AMD at
least) When sRGB is decoded, 1.0 -> 1.0.  Therefore, 1.0 multiplier = 80
nits for SDR content. So if you want, 203 nits for SDR content, pass in
(203.0 / 80.0).

Co-developed-by: Melissa Wen <mwen at igalia.com>
Signed-off-by: Melissa Wen <mwen at igalia.com>
Signed-off-by: Joshua Ashton <joshua at froggi.es>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c   |  6 +++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h      |  4 +++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 12 +++++++++
 .../amd/display/amdgpu_dm/amdgpu_dm_plane.c   | 25 ++++++++++++++-----
 4 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 24595906dab1..dd658f162f6f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -1326,6 +1326,12 @@ amdgpu_display_create_color_properties(struct amdgpu_device *adev)
 		return -ENOMEM;
 	adev->mode_info.plane_degamma_tf_property = prop;
 
+	prop = drm_property_create_range(adev_to_drm(adev),
+					 0, "AMD_PLANE_HDR_MULT", 0, UINT_MAX);
+	if (!prop)
+		return -ENOMEM;
+	adev->mode_info.plane_hdr_mult_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 ab9ce6f26c90..65a9d62ffbe4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -387,6 +387,10 @@ struct amdgpu_mode_info {
 	 * linearize content with or without LUT.
 	 */
 	struct drm_property *plane_degamma_tf_property;
+	/**
+	 * @plane_hdr_mult_property:
+	 */
+	struct drm_property *plane_hdr_mult_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 005632c1c9ec..bb7307b9cfd5 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -51,6 +51,7 @@
 
 #define AMDGPU_DMUB_NOTIFICATION_MAX 5
 
+#define AMDGPU_HDR_MULT_DEFAULT (0x100000000LL)
 /*
 #include "include/amdgpu_dal_power_if.h"
 #include "amdgpu_dm_irq.h"
@@ -736,6 +737,17 @@ struct dm_plane_state {
 	 * linearize.
 	 */
 	enum drm_transfer_function degamma_tf;
+	/**
+	 * @hdr_mult:
+	 *
+	 * Multiplier to 'gain' the plane.  When PQ is decoded using the fixed
+	 * func transfer function to the internal FP16 fb, 1.0 -> 80 nits (on
+	 * AMD at least). When sRGB is decoded, 1.0 -> 1.0, obviously.
+	 * Therefore, 1.0 multiplier = 80 nits for SDR content.  So if you
+	 * want, 203 nits for SDR content, pass in (203.0 / 80.0).  Format is
+	 * S31.32 sign-magnitude.
+	 */
+	__u64 hdr_mult;
 #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 5b458cc0781c..57169dae8b3d 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
@@ -1321,8 +1321,10 @@ static void dm_drm_plane_reset(struct drm_plane *plane)
 		__drm_atomic_helper_plane_reset(plane, &amdgpu_state->base);
 
 #ifdef CONFIG_STEAM_DECK
-	if (amdgpu_state)
+	if (amdgpu_state) {
 		amdgpu_state->degamma_tf = DRM_TRANSFER_FUNCTION_DEFAULT;
+		amdgpu_state->hdr_mult = AMDGPU_HDR_MULT_DEFAULT;
+	}
 #endif
 }
 
@@ -1424,11 +1426,11 @@ static void dm_drm_plane_destroy_state(struct drm_plane *plane,
 #ifdef CONFIG_STEAM_DECK
 int
 amdgpu_dm_replace_property_blob_from_id(struct drm_device *dev,
-					       struct drm_property_blob **blob,
-					       uint64_t blob_id,
-					       ssize_t expected_size,
-					       ssize_t expected_elem_size,
-					       bool *replaced)
+					struct drm_property_blob **blob,
+					uint64_t blob_id,
+					ssize_t expected_size,
+					ssize_t expected_elem_size,
+					bool *replaced)
 {
 	struct drm_property_blob *new_blob = NULL;
 
@@ -1482,6 +1484,10 @@ dm_plane_attach_color_mgmt_properties(struct amdgpu_display_manager *dm,
 					   dm->adev->mode_info.plane_degamma_tf_property,
 					   DRM_TRANSFER_FUNCTION_DEFAULT);
 	}
+	/* HDR MULT is always available */
+	drm_object_attach_property(&plane->base,
+				   dm->adev->mode_info.plane_hdr_mult_property,
+				   AMDGPU_HDR_MULT_DEFAULT);
 }
 
 static int
@@ -1507,6 +1513,11 @@ dm_atomic_plane_set_property(struct drm_plane *plane,
 			dm_plane_state->degamma_tf = val;
 			dm_plane_state->base.color_mgmt_changed = 1;
 		}
+	} else if (property == adev->mode_info.plane_hdr_mult_property) {
+		if (dm_plane_state->hdr_mult != val) {
+			dm_plane_state->hdr_mult = val;
+			dm_plane_state->base.color_mgmt_changed = 1;
+		}
 	} else {
 		drm_dbg_atomic(plane->dev,
 			       "[PLANE:%d:%s] unknown property [PROP:%d:%s]]\n",
@@ -1533,6 +1544,8 @@ dm_atomic_plane_get_property(struct drm_plane *plane,
 			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 if (property == adev->mode_info.plane_hdr_mult_property) {
+		*val = dm_plane_state->hdr_mult;
 	} else {
 		return -EINVAL;
 	}
-- 
2.39.2