bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
{
u8 link_status[DP_LINK_STATUS_SIZE];
struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
if (!radeon_dp_get_link_status(radeon_connector, link_status))
return false;
if (dp_channel_eq_ok(link_status, dig->dp_lane_count))
return false;
return true;
}
static int radeon_dp_link_train_ce(struct radeon_dp_link_train_info *dp_info)
{
bool channel_eq;
if (dp_info->tp3_supported)
radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
else
radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
/* channel equalization loop */
dp_info->tries = 0;
channel_eq = false;
while (1) {
if (dp_info->rd_interval == 0)
udelay(400);
else
mdelay(dp_info->rd_interval * 4);
if (!radeon_dp_get_link_status(dp_info->radeon_connector, dp_info->link_status)) {
DRM_ERROR("displayport link status failed\n");
break;
}
if (dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
channel_eq = true;
break;
}
/* Try 5 times */
if (dp_info->tries > 5) {
DRM_ERROR("channel eq failed: 5 tries\n");
break;
}
/* Compute new train_set as requested by sink */
dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);
radeon_dp_update_vs_emph(dp_info);
dp_info->tries++;
}
if (!channel_eq) {
DRM_ERROR("channel eq failed\n");
return -1;
} else {
DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
(dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
>> DP_TRAIN_PRE_EMPHASIS_SHIFT);
return 0;
}
}
void dp_link_train(struct drm_encoder *encoder,
struct drm_connector *connector)
{
struct drm_device *dev = encoder->dev;
struct radeon_device *rdev = dev->dev_private;
struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
struct radeon_encoder_atom_dig *dig;
struct radeon_connector *radeon_connector;
struct radeon_connector_atom_dig *dig_connector;
int enc_id = 0;
bool clock_recovery, channel_eq;
u8 link_status[DP_LINK_STATUS_SIZE];
u8 link_configuration[DP_LINK_CONFIGURATION_SIZE];
u8 tries, voltage;
u8 train_set[4];
int i;
if ((connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort) &&
(connector->connector_type != DRM_MODE_CONNECTOR_eDP))
return;
if (!radeon_encoder->enc_priv)
return;
dig = radeon_encoder->enc_priv;
radeon_connector = to_radeon_connector(connector);
if (!radeon_connector->con_priv)
return;
dig_connector = radeon_connector->con_priv;
if (dig->dig_encoder)
enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;
else
enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER;
if (dig_connector->linkb)
enc_id |= ATOM_DP_CONFIG_LINK_B;
else
enc_id |= ATOM_DP_CONFIG_LINK_A;
memset(link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
if (dig_connector->dp_clock == 270000)
link_configuration[0] = DP_LINK_BW_2_7;
else
link_configuration[0] = DP_LINK_BW_1_62;
link_configuration[1] = dig_connector->dp_lane_count;
if (dig_connector->dpcd[0] >= 0x11)
link_configuration[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
/* power up the sink */
dp_set_power(radeon_connector, DP_SET_POWER_D0);
/* disable the training pattern on the sink */
dp_set_training(radeon_connector, DP_TRAINING_PATTERN_DISABLE);
/* set link bw and lanes on the sink */
dp_set_link_bw_lanes(radeon_connector, link_configuration);
/* disable downspread on the sink */
dp_set_downspread(radeon_connector, 0);
/* start training on the source */
radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_START,
dig_connector->dp_clock, enc_id, 0);
/* set training pattern 1 on the source */
radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
dig_connector->dp_clock, enc_id, 0);
/* set initial vs/emph */
memset(train_set, 0, 4);
udelay(400);
/* set training pattern 1 on the sink */
dp_set_training(radeon_connector, DP_TRAINING_PATTERN_1);
dp_update_dpvs_emph(radeon_connector, encoder, train_set);
/* clock recovery loop */
clock_recovery = false;
tries = 0;
voltage = 0xff;
for (;;) {
udelay(100);
if (!atom_dp_get_link_status(radeon_connector, link_status))
break;
if (dp_clock_recovery_ok(link_status, dig_connector->dp_lane_count)) {
clock_recovery = true;
break;
}
for (i = 0; i < dig_connector->dp_lane_count; i++) {
if ((train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
break;
}
if (i == dig_connector->dp_lane_count) {
DRM_ERROR("clock recovery reached max voltage\n");
break;
}
if ((train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
++tries;
if (tries == 5) {
DRM_ERROR("clock recovery tried 5 times\n");
break;
}
} else
tries = 0;
voltage = train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
/* Compute new train_set as requested by sink */
dp_get_adjust_train(link_status, dig_connector->dp_lane_count, train_set);
dp_update_dpvs_emph(radeon_connector, encoder, train_set);
}
if (!clock_recovery)
DRM_ERROR("clock recovery failed\n");
else
DRM_DEBUG("clock recovery at voltage %d pre-emphasis %d\n",
train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
(train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
DP_TRAIN_PRE_EMPHASIS_SHIFT);
/* set training pattern 2 on the sink */
dp_set_training(radeon_connector, DP_TRAINING_PATTERN_2);
/* set training pattern 2 on the source */
radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
dig_connector->dp_clock, enc_id, 1);
/* channel equalization loop */
tries = 0;
channel_eq = false;
for (;;) {
udelay(400);
if (!atom_dp_get_link_status(radeon_connector, link_status))
break;
if (dp_channel_eq_ok(link_status, dig_connector->dp_lane_count)) {
channel_eq = true;
break;
}
/* Try 5 times */
if (tries > 5) {
DRM_ERROR("channel eq failed: 5 tries\n");
break;
}
/* Compute new train_set as requested by sink */
dp_get_adjust_train(link_status, dig_connector->dp_lane_count, train_set);
dp_update_dpvs_emph(radeon_connector, encoder, train_set);
tries++;
}
if (!channel_eq)
DRM_ERROR("channel eq failed\n");
else
DRM_DEBUG("channel eq at voltage %d pre-emphasis %d\n",
train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
(train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
>> DP_TRAIN_PRE_EMPHASIS_SHIFT);
/* disable the training pattern on the sink */
dp_set_training(radeon_connector, DP_TRAINING_PATTERN_DISABLE);
radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_COMPLETE,
dig_connector->dp_clock, enc_id, 0);
}
