drm/amd/display: add HDR multiplier support

With `dc_fixpt_from_s3132()` translation, we can just use it to set
hdr_mult.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -8268,6 +8268,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 			bundle->surface_updates[planes_count].gamma = dc_plane->gamma_correction;
 			bundle->surface_updates[planes_count].in_transfer_func = dc_plane->in_transfer_func;
 			bundle->surface_updates[planes_count].gamut_remap_matrix = &dc_plane->gamut_remap_matrix;
+			bundle->surface_updates[planes_count].hdr_mult = dc_plane->hdr_mult;
 		}
 
 		amdgpu_dm_plane_fill_dc_scaling_info(dm->adev, new_plane_state,

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c

@@ -927,6 +927,7 @@ int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc,
 				      struct drm_plane_state *plane_state,
 				      struct dc_plane_state *dc_plane_state)
 {
+	struct dm_plane_state *dm_plane_state = to_dm_plane_state(plane_state);
 	bool has_crtc_cm_degamma;
 	int ret;
 
@@ -937,6 +938,8 @@ int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc,
 	/* After, we start to update values according to color props */
 	has_crtc_cm_degamma = (crtc->cm_has_degamma || crtc->cm_is_degamma_srgb);
 
+	dc_plane_state->hdr_mult = dc_fixpt_from_s3132(dm_plane_state->hdr_mult);
+
 	ret = __set_dm_plane_degamma(plane_state, dc_plane_state);
 	if (ret == -ENOMEM)
 		return ret;