drm/amd/display: Add stub to get DPIA tunneling device data

[why & how]
1. Add stub for getting tunneling device data
2. Add check for phy_repeater_cnt < 0xff to LTTPR check
3. Add two more bits of information to DPIA links
Reviewed-by: NJun Lei <Jun.Lei@amd.com>
Acked-by: NWayne Lin <Wayne.Lin@amd.com>
Acked-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NJimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/Makefile

@@ -59,7 +59,7 @@ include $(AMD_DC)
 
 DISPLAY_CORE = dc.o  dc_stat.o dc_link.o dc_resource.o dc_hw_sequencer.o dc_sink.o \
 dc_surface.o dc_link_hwss.o dc_link_dp.o dc_link_ddc.o dc_debug.o dc_stream.o \
-dc_link_enc_cfg.o dc_link_dpcd.o
+dc_link_enc_cfg.o dc_link_dpia.o dc_link_dpcd.o
 
 ifdef CONFIG_DRM_AMD_DC_DCN
 DISPLAY_CORE += dc_vm_helper.o

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -1726,6 +1726,7 @@ static bool dc_link_construct_dpia(struct dc_link *link,
 	/* Dummy Init for linkid */
 	link->link_id.type = OBJECT_TYPE_CONNECTOR;
 	link->link_id.id = CONNECTOR_ID_DISPLAY_PORT;
+	link->link_id.enum_id = ENUM_ID_1 + init_params->connector_index;
 	link->is_internal_display = false;
 	link->connector_signal = SIGNAL_TYPE_DISPLAY_PORT;
 	LINK_INFO("Connector[%d] description:signal %d\n",
@@ -1733,6 +1734,7 @@ static bool dc_link_construct_dpia(struct dc_link *link,
 		  link->connector_signal);
 
 	link->ep_type = DISPLAY_ENDPOINT_USB4_DPIA;
+	link->is_dig_mapping_flexible = true;
 
 	/* TODO: Initialize link : funcs->link_init */
 

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -36,6 +36,7 @@
 #include "dpcd_defs.h"
 #include "dc_dmub_srv.h"
 #include "dce/dmub_hw_lock_mgr.h"
+#include "inc/dc_link_dpia.h"
 #include "inc/link_enc_cfg.h"
 
 /*Travis*/
@@ -4580,6 +4581,7 @@ bool dp_retrieve_lttpr_cap(struct dc_link *link)
 
 		/* Attempt to train in LTTPR transparent mode if repeater count exceeds 8. */
 		is_lttpr_present = (dp_convert_to_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt) != 0 &&
+				link->dpcd_caps.lttpr_caps.phy_repeater_cnt < 0xff &&
 				link->dpcd_caps.lttpr_caps.max_lane_count > 0 &&
 				link->dpcd_caps.lttpr_caps.max_lane_count <= 4 &&
 				link->dpcd_caps.lttpr_caps.revision.raw >= 0x14);
@@ -4628,6 +4630,8 @@ static bool retrieve_link_cap(struct dc_link *link)
 			LINK_AUX_DEFAULT_LTTPR_TIMEOUT_PERIOD);
 
 	is_lttpr_present = dp_retrieve_lttpr_cap(link);
+	/* Read DP tunneling information. */
+	status = dpcd_get_tunneling_device_data(link);
 
 	status = core_link_read_dpcd(link, DP_SET_POWER,
 			&dpcd_power_state, sizeof(dpcd_power_state));

drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c

+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2021 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#include "dc_link_dpia.h"
+#include "inc/core_status.h"
+#include "dc_link.h"
+
+enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link)
+{
+	/** @todo Read corresponding DPCD region and update link caps. */
+	return DC_OK;
+}

drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright 2021 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __DC_LINK_DPIA_H__
+#define __DC_LINK_DPIA_H__
+
+/* This module implements functionality for training DPIA links. */
+
+struct dc_link;
+
+/* Read tunneling device capability from DPCD and update link capability
+ * accordingly.
+ */
+enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link);
+
+#endif /* __DC_LINK_DPIA_H__ */