linux/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_fixed_vs_pe_retimer.c

/*
 * Copyright 2022 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
 *
 */

/* FILE POLICY AND INTENDED USAGE:
 * This file implements 8b/10b link training specially modified to support an
 * embedded retimer chip. This retimer chip is referred as fixed vs pe retimer.
 * Unlike native dp connection this chip requires a modified link training
 * protocol based on 8b/10b link training. Since this is a non standard sequence
 * and we must support this hardware, we decided to isolate it in its own
 * training sequence inside its own file.
 */
#include "link_dp_training_fixed_vs_pe_retimer.h"
#include "link_dp_training_8b_10b.h"
#include "link_dpcd.h"
#include "link_dp_phy.h"
#include "link_dp_capability.h"
#include "link_ddc.h"

#define DC_LOGGER …

void dp_fixed_vs_pe_read_lane_adjust(
	struct dc_link *link,
	union dpcd_training_lane dpcd_lane_adjust[LANE_COUNT_DP_MAX])
{ … }


void dp_fixed_vs_pe_set_retimer_lane_settings(
	struct dc_link *link,
	const union dpcd_training_lane dpcd_lane_adjust[LANE_COUNT_DP_MAX],
	uint8_t lane_count)
{ … }

static enum link_training_result perform_fixed_vs_pe_nontransparent_training_sequence(
		struct dc_link *link,
		const struct link_resource *link_res,
		struct link_training_settings *lt_settings)
{ … }

enum link_training_result dp_perform_fixed_vs_pe_training_sequence(
	struct dc_link *link,
	const struct link_resource *link_res,
	struct link_training_settings *lt_settings)
{ … }