drm/amd/display: Decouple ABM init from dmcu

[Why]
With ABM implemented on DMUB the ABM enablement
shoudn't be solely rely on dmcu. Otherwise it won't work
if dmcu is disabled.

[How]
1. Decouple dmcub config copy from dmcu iram copy.
2. Set abm connector property if either dmcu or dmub enabled.
Signed-off-by: Roman Li <roman.li@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1376,7 +1376,7 @@ static int dm_late_init(void *handle)
 	unsigned int linear_lut[16];
 	int i;
 	struct dmcu *dmcu = NULL;
-	bool ret;
+	bool ret = true;
 
 	if (!adev->dm.fw_dmcu)
 		return detect_mst_link_for_all_connectors(adev->ddev);
@@ -1397,7 +1397,14 @@ static int dm_late_init(void *handle)
 	 */
 	params.min_abm_backlight = 0x28F;
 
-	ret = dmcu_load_iram(dmcu, params);
+	/* In the case where abm is implemented on dmcub,
+	 * dmcu object will be null.
+	 * ABM 2.4 and up are implemented on dmcub.
+	 */
+	if (dmcu)
+		ret = dmcu_load_iram(dmcu, params);
+	else if (adev->dm.dc->ctx->dmub_srv)
+		ret = dmub_init_abm_config(adev->dm.dc->res_pool->abm, params);
 
 	if (!ret)
 		return -EINVAL;
@@ -6226,7 +6233,7 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 	aconnector->base.state->max_requested_bpc = aconnector->base.state->max_bpc;
 
 	if (connector_type == DRM_MODE_CONNECTOR_eDP &&
-	    dc_is_dmcu_initialized(adev->dm.dc)) {
+	    (dc_is_dmcu_initialized(adev->dm.dc) || adev->dm.dc->ctx->dmub_srv)) {
 		drm_object_attach_property(&aconnector->base.base,
 				adev->mode_info.abm_level_property, 0);
 	}