/*
* 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 \
link->ctx->logger
void dp_fixed_vs_pe_read_lane_adjust(
struct dc_link *link,
union dpcd_training_lane dpcd_lane_adjust[LANE_COUNT_DP_MAX])
{
const uint8_t vendor_lttpr_write_data_vs[3] = {0x0, 0x53, 0x63};
const uint8_t vendor_lttpr_write_data_pe[3] = {0x0, 0x54, 0x63};
uint8_t dprx_vs = 0;
uint8_t dprx_pe = 0;
uint8_t lane;
/* W/A to read lane settings requested by DPRX */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_vs[0], sizeof(vendor_lttpr_write_data_vs));
link_query_fixed_vs_pe_retimer(link->ddc, &dprx_vs, 1);
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_pe[0], sizeof(vendor_lttpr_write_data_pe));
link_query_fixed_vs_pe_retimer(link->ddc, &dprx_pe, 1);
for (lane = 0; lane < LANE_COUNT_DP_MAX; lane++) {
dpcd_lane_adjust[lane].bits.VOLTAGE_SWING_SET = (dprx_vs >> (2 * lane)) & 0x3;
dpcd_lane_adjust[lane].bits.PRE_EMPHASIS_SET = (dprx_pe >> (2 * lane)) & 0x3;
}
}
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)
{
const uint8_t vendor_lttpr_write_data_reset[4] = {0x1, 0x50, 0x63, 0xFF};
uint8_t vendor_lttpr_write_data_vs[4] = {0x1, 0x51, 0x63, 0x0};
uint8_t vendor_lttpr_write_data_pe[4] = {0x1, 0x52, 0x63, 0x0};
uint8_t lane = 0;
for (lane = 0; lane < lane_count; lane++) {
vendor_lttpr_write_data_vs[3] |=
dpcd_lane_adjust[lane].bits.VOLTAGE_SWING_SET << (2 * lane);
vendor_lttpr_write_data_pe[3] |=
dpcd_lane_adjust[lane].bits.PRE_EMPHASIS_SET << (2 * lane);
}
/* Force LTTPR to output desired VS and PE */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_reset[0], sizeof(vendor_lttpr_write_data_reset));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_vs[0], sizeof(vendor_lttpr_write_data_vs));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_pe[0], sizeof(vendor_lttpr_write_data_pe));
}
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 status = LINK_TRAINING_SUCCESS;
uint8_t lane = 0;
uint8_t toggle_rate = 0x6;
uint8_t target_rate = 0x6;
bool apply_toggle_rate_wa = false;
uint8_t repeater_cnt;
uint8_t repeater_id;
/* Fixed VS/PE specific: Force CR AUX RD Interval to at least 16ms */
if (lt_settings->cr_pattern_time < 16000)
lt_settings->cr_pattern_time = 16000;
/* Fixed VS/PE specific: Toggle link rate */
apply_toggle_rate_wa = ((link->vendor_specific_lttpr_link_rate_wa == target_rate) || (link->vendor_specific_lttpr_link_rate_wa == 0));
target_rate = get_dpcd_link_rate(<_settings->link_settings);
toggle_rate = (target_rate == 0x6) ? 0xA : 0x6;
if (apply_toggle_rate_wa)
lt_settings->link_settings.link_rate = toggle_rate;
if (link->ctx->dc->work_arounds.lt_early_cr_pattern)
start_clock_recovery_pattern_early(link, link_res, lt_settings, DPRX);
/* 1. set link rate, lane count and spread. */
dpcd_set_link_settings(link, lt_settings);
/* Fixed VS/PE specific: Toggle link rate back*/
if (apply_toggle_rate_wa) {
core_link_write_dpcd(
link,
DP_LINK_BW_SET,
&target_rate,
1);
}
link->vendor_specific_lttpr_link_rate_wa = target_rate;
if (lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) {
/* 2. perform link training (set link training done
* to false is done as well)
*/
repeater_cnt = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
for (repeater_id = repeater_cnt; (repeater_id > 0 && status == LINK_TRAINING_SUCCESS);
repeater_id--) {
status = perform_8b_10b_clock_recovery_sequence(link, link_res, lt_settings, repeater_id);
if (status != LINK_TRAINING_SUCCESS) {
repeater_training_done(link, repeater_id);
break;
}
status = perform_8b_10b_channel_equalization_sequence(link,
link_res,
lt_settings,
repeater_id);
repeater_training_done(link, repeater_id);
if (status != LINK_TRAINING_SUCCESS)
break;
for (lane = 0; lane < LANE_COUNT_DP_MAX; lane++) {
lt_settings->dpcd_lane_settings[lane].raw = 0;
lt_settings->hw_lane_settings[lane].VOLTAGE_SWING = 0;
lt_settings->hw_lane_settings[lane].PRE_EMPHASIS = 0;
}
}
}
if (status == LINK_TRAINING_SUCCESS) {
status = perform_8b_10b_clock_recovery_sequence(link, link_res, lt_settings, DPRX);
if (status == LINK_TRAINING_SUCCESS) {
status = perform_8b_10b_channel_equalization_sequence(link,
link_res,
lt_settings,
DPRX);
}
}
return status;
}
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)
{
const uint8_t vendor_lttpr_write_data_reset[4] = {0x1, 0x50, 0x63, 0xFF};
const uint8_t offset = dp_parse_lttpr_repeater_count(
link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
const uint8_t vendor_lttpr_write_data_intercept_en[4] = {0x1, 0x55, 0x63, 0x0};
const uint8_t vendor_lttpr_write_data_intercept_dis[4] = {0x1, 0x55, 0x63, 0x6E};
const uint8_t vendor_lttpr_write_data_adicora_eq1[4] = {0x1, 0x55, 0x63, 0x2E};
const uint8_t vendor_lttpr_write_data_adicora_eq2[4] = {0x1, 0x55, 0x63, 0x01};
const uint8_t vendor_lttpr_write_data_adicora_eq3[4] = {0x1, 0x55, 0x63, 0x68};
uint32_t pre_disable_intercept_delay_ms = 0;
uint8_t vendor_lttpr_write_data_vs[4] = {0x1, 0x51, 0x63, 0x0};
uint8_t vendor_lttpr_write_data_pe[4] = {0x1, 0x52, 0x63, 0x0};
const uint8_t vendor_lttpr_write_data_4lane_1[4] = {0x1, 0x6E, 0xF2, 0x19};
const uint8_t vendor_lttpr_write_data_4lane_2[4] = {0x1, 0x6B, 0xF2, 0x01};
const uint8_t vendor_lttpr_write_data_4lane_3[4] = {0x1, 0x6D, 0xF2, 0x18};
const uint8_t vendor_lttpr_write_data_4lane_4[4] = {0x1, 0x6C, 0xF2, 0x03};
const uint8_t vendor_lttpr_write_data_4lane_5[4] = {0x1, 0x03, 0xF3, 0x06};
const uint8_t vendor_lttpr_write_data_dpmf[4] = {0x1, 0x6, 0x70, 0x87};
enum link_training_result status = LINK_TRAINING_SUCCESS;
uint8_t lane = 0;
union down_spread_ctrl downspread = {0};
union lane_count_set lane_count_set = {0};
uint8_t toggle_rate;
uint8_t rate;
/* Only 8b/10b is supported */
ASSERT(link_dp_get_encoding_format(<_settings->link_settings) ==
DP_8b_10b_ENCODING);
if (lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) {
status = perform_fixed_vs_pe_nontransparent_training_sequence(link, link_res, lt_settings);
return status;
}
if (offset != 0xFF) {
if (offset == 2) {
pre_disable_intercept_delay_ms = link->dc->debug.fixed_vs_aux_delay_config_wa;
/* Certain display and cable configuration require extra delay */
} else if (offset > 2) {
pre_disable_intercept_delay_ms = link->dc->debug.fixed_vs_aux_delay_config_wa * 2;
}
}
/* Vendor specific: Reset lane settings */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_reset[0], sizeof(vendor_lttpr_write_data_reset));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_vs[0], sizeof(vendor_lttpr_write_data_vs));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_pe[0], sizeof(vendor_lttpr_write_data_pe));
/* Vendor specific: Enable intercept */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_intercept_en[0], sizeof(vendor_lttpr_write_data_intercept_en));
/* 1. set link rate, lane count and spread. */
downspread.raw = (uint8_t)(lt_settings->link_settings.link_spread);
lane_count_set.bits.LANE_COUNT_SET =
lt_settings->link_settings.lane_count;
lane_count_set.bits.ENHANCED_FRAMING = lt_settings->enhanced_framing;
lane_count_set.bits.POST_LT_ADJ_REQ_GRANTED = 0;
if (lt_settings->pattern_for_eq < DP_TRAINING_PATTERN_SEQUENCE_4) {
lane_count_set.bits.POST_LT_ADJ_REQ_GRANTED =
link->dpcd_caps.max_ln_count.bits.POST_LT_ADJ_REQ_SUPPORTED;
}
core_link_write_dpcd(link, DP_DOWNSPREAD_CTRL,
&downspread.raw, sizeof(downspread));
core_link_write_dpcd(link, DP_LANE_COUNT_SET,
&lane_count_set.raw, 1);
rate = get_dpcd_link_rate(<_settings->link_settings);
if (!link->dpcd_caps.lttpr_caps.main_link_channel_coding.bits.DP_128b_132b_SUPPORTED) {
/* Vendor specific: Toggle link rate */
toggle_rate = (rate == 0x6) ? 0xA : 0x6;
if (link->vendor_specific_lttpr_link_rate_wa == rate || link->vendor_specific_lttpr_link_rate_wa == 0) {
core_link_write_dpcd(
link,
DP_LINK_BW_SET,
&toggle_rate,
1);
}
link->vendor_specific_lttpr_link_rate_wa = rate;
}
core_link_write_dpcd(link, DP_LINK_BW_SET, &rate, 1);
DC_LOG_HW_LINK_TRAINING("%s\n %x rate = %x\n %x lane = %x framing = %x\n %x spread = %x\n",
__func__,
DP_LINK_BW_SET,
lt_settings->link_settings.link_rate,
DP_LANE_COUNT_SET,
lt_settings->link_settings.lane_count,
lt_settings->enhanced_framing,
DP_DOWNSPREAD_CTRL,
lt_settings->link_settings.link_spread);
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_dpmf[0],
sizeof(vendor_lttpr_write_data_dpmf));
if (lt_settings->link_settings.lane_count == LANE_COUNT_FOUR) {
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_4lane_1[0], sizeof(vendor_lttpr_write_data_4lane_1));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_4lane_2[0], sizeof(vendor_lttpr_write_data_4lane_2));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_4lane_3[0], sizeof(vendor_lttpr_write_data_4lane_3));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_4lane_4[0], sizeof(vendor_lttpr_write_data_4lane_4));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_4lane_5[0], sizeof(vendor_lttpr_write_data_4lane_5));
}
/* 2. Perform link training */
/* Perform Clock Recovery Sequence */
if (status == LINK_TRAINING_SUCCESS) {
const uint8_t max_vendor_dpcd_retries = 10;
uint32_t retries_cr;
uint32_t retry_count;
uint32_t wait_time_microsec;
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX];
union lane_align_status_updated dpcd_lane_status_updated;
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
uint8_t i = 0;
retries_cr = 0;
retry_count = 0;
memset(&dpcd_lane_status, '\0', sizeof(dpcd_lane_status));
memset(&dpcd_lane_status_updated, '\0',
sizeof(dpcd_lane_status_updated));
while ((retries_cr < LINK_TRAINING_MAX_RETRY_COUNT) &&
(retry_count < LINK_TRAINING_MAX_CR_RETRY)) {
/* 1. call HWSS to set lane settings */
dp_set_hw_lane_settings(
link,
link_res,
lt_settings,
0);
/* 2. update DPCD of the receiver */
if (!retry_count) {
/* EPR #361076 - write as a 5-byte burst,
* but only for the 1-st iteration.
*/
dpcd_set_lt_pattern_and_lane_settings(
link,
lt_settings,
lt_settings->pattern_for_cr,
0);
/* Vendor specific: Disable intercept */
for (i = 0; i < max_vendor_dpcd_retries; i++) {
if (pre_disable_intercept_delay_ms != 0)
msleep(pre_disable_intercept_delay_ms);
if (link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_intercept_dis[0],
sizeof(vendor_lttpr_write_data_intercept_dis)))
break;
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_intercept_en[0],
sizeof(vendor_lttpr_write_data_intercept_en));
}
} else {
vendor_lttpr_write_data_vs[3] = 0;
vendor_lttpr_write_data_pe[3] = 0;
for (lane = 0; lane < lane_count; lane++) {
vendor_lttpr_write_data_vs[3] |=
lt_settings->dpcd_lane_settings[lane].bits.VOLTAGE_SWING_SET << (2 * lane);
vendor_lttpr_write_data_pe[3] |=
lt_settings->dpcd_lane_settings[lane].bits.PRE_EMPHASIS_SET << (2 * lane);
}
/* Vendor specific: Update VS and PE to DPRX requested value */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_vs[0], sizeof(vendor_lttpr_write_data_vs));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_pe[0], sizeof(vendor_lttpr_write_data_pe));
dpcd_set_lane_settings(
link,
lt_settings,
0);
}
/* 3. wait receiver to lock-on*/
wait_time_microsec = lt_settings->cr_pattern_time;
dp_wait_for_training_aux_rd_interval(
link,
wait_time_microsec);
/* 4. Read lane status and requested drive
* settings as set by the sink
*/
dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
0);
/* 5. check CR done*/
if (dp_is_cr_done(lane_count, dpcd_lane_status)) {
status = LINK_TRAINING_SUCCESS;
break;
}
/* 6. max VS reached*/
if (dp_is_max_vs_reached(lt_settings))
break;
/* 7. same lane settings */
/* Note: settings are the same for all lanes,
* so comparing first lane is sufficient
*/
if (lt_settings->dpcd_lane_settings[0].bits.VOLTAGE_SWING_SET ==
dpcd_lane_adjust[0].bits.VOLTAGE_SWING_LANE)
retries_cr++;
else
retries_cr = 0;
/* 8. update VS/PE/PC2 in lt_settings*/
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
retry_count++;
}
if (retry_count >= LINK_TRAINING_MAX_CR_RETRY) {
ASSERT(0);
DC_LOG_ERROR("%s: Link Training Error, could not get CR after %d tries. Possibly voltage swing issue",
__func__,
LINK_TRAINING_MAX_CR_RETRY);
}
status = dp_get_cr_failure(lane_count, dpcd_lane_status);
}
/* Perform Channel EQ Sequence */
if (status == LINK_TRAINING_SUCCESS) {
enum dc_dp_training_pattern tr_pattern;
uint32_t retries_ch_eq;
uint32_t wait_time_microsec;
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_align_status_updated dpcd_lane_status_updated = {0};
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = {0};
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_adicora_eq1[0],
sizeof(vendor_lttpr_write_data_adicora_eq1));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_adicora_eq2[0],
sizeof(vendor_lttpr_write_data_adicora_eq2));
/* Note: also check that TPS4 is a supported feature*/
tr_pattern = lt_settings->pattern_for_eq;
dp_set_hw_training_pattern(link, link_res, tr_pattern, 0);
status = LINK_TRAINING_EQ_FAIL_EQ;
for (retries_ch_eq = 0; retries_ch_eq <= LINK_TRAINING_MAX_RETRY_COUNT;
retries_ch_eq++) {
dp_set_hw_lane_settings(link, link_res, lt_settings, 0);
vendor_lttpr_write_data_vs[3] = 0;
vendor_lttpr_write_data_pe[3] = 0;
for (lane = 0; lane < lane_count; lane++) {
vendor_lttpr_write_data_vs[3] |=
lt_settings->dpcd_lane_settings[lane].bits.VOLTAGE_SWING_SET << (2 * lane);
vendor_lttpr_write_data_pe[3] |=
lt_settings->dpcd_lane_settings[lane].bits.PRE_EMPHASIS_SET << (2 * lane);
}
/* Vendor specific: Update VS and PE to DPRX requested value */
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_vs[0], sizeof(vendor_lttpr_write_data_vs));
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_pe[0], sizeof(vendor_lttpr_write_data_pe));
/* 2. update DPCD*/
if (!retries_ch_eq) {
/* EPR #361076 - write as a 5-byte burst,
* but only for the 1-st iteration
*/
dpcd_set_lt_pattern_and_lane_settings(
link,
lt_settings,
tr_pattern, 0);
link_configure_fixed_vs_pe_retimer(link->ddc,
&vendor_lttpr_write_data_adicora_eq3[0],
sizeof(vendor_lttpr_write_data_adicora_eq3));
} else
dpcd_set_lane_settings(link, lt_settings, 0);
/* 3. wait for receiver to lock-on*/
wait_time_microsec = lt_settings->eq_pattern_time;
dp_wait_for_training_aux_rd_interval(
link,
wait_time_microsec);
/* 4. Read lane status and requested
* drive settings as set by the sink
*/
dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
0);
/* 5. check CR done*/
if (!dp_is_cr_done(lane_count, dpcd_lane_status)) {
status = LINK_TRAINING_EQ_FAIL_CR;
break;
}
/* 6. check CHEQ done*/
if (dp_is_ch_eq_done(lane_count, dpcd_lane_status) &&
dp_is_symbol_locked(lane_count, dpcd_lane_status) &&
dp_is_interlane_aligned(dpcd_lane_status_updated)) {
status = LINK_TRAINING_SUCCESS;
break;
}
/* 7. update VS/PE/PC2 in lt_settings*/
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
}
}
return status;
}
Codebase Browser
linux