static int analogix_dp_link_start(struct analogix_dp_device *dp)
{
u8 buf[4];
int lane, lane_count, pll_tries, retval;
lane_count = dp->link_train.lane_count;
dp->link_train.lt_state = CLOCK_RECOVERY;
dp->link_train.eq_loop = 0;
for (lane = 0; lane < lane_count; lane++)
dp->link_train.cr_loop[lane] = 0;
/* Set link rate and count as you want to establish*/
analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
/* Setup RX configuration */
buf[0] = dp->link_train.link_rate;
buf[1] = dp->link_train.lane_count;
retval = analogix_dp_write_bytes_to_dpcd(dp, DP_LINK_BW_SET, 2, buf);
if (retval)
return retval;
/* Set TX pre-emphasis to minimum */
for (lane = 0; lane < lane_count; lane++)
analogix_dp_set_lane_lane_pre_emphasis(dp,
PRE_EMPHASIS_LEVEL_0, lane);
/* Wait for PLL lock */
pll_tries = 0;
while (analogix_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) {
if (pll_tries == DP_TIMEOUT_LOOP_COUNT) {
dev_err(dp->dev, "Wait for PLL lock timed out\n");
return -ETIMEDOUT;
}
pll_tries++;
usleep_range(90, 120);
}
/* Set training pattern 1 */
analogix_dp_set_training_pattern(dp, TRAINING_PTN1);
/* Set RX training pattern */
retval = analogix_dp_write_byte_to_dpcd(dp,
DP_TRAINING_PATTERN_SET,
DP_LINK_SCRAMBLING_DISABLE | DP_TRAINING_PATTERN_1);
if (retval)
return retval;
for (lane = 0; lane < lane_count; lane++)
buf[lane] = DP_TRAIN_PRE_EMPH_LEVEL_0 |
DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
retval = analogix_dp_write_bytes_to_dpcd(dp, DP_TRAINING_LANE0_SET,
lane_count, buf);
return retval;
}
static void analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
{
analogix_dp_set_training_pattern(dp, DP_NONE);
drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
DP_TRAINING_PATTERN_DISABLE);
}
static void analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
{
analogix_dp_set_training_pattern(dp, DP_NONE);
analogix_dp_write_byte_to_dpcd(dp, DP_TRAINING_PATTERN_SET,
DP_TRAINING_PATTERN_DISABLE);
}
static int analogix_dp_process_clock_recovery(struct analogix_dp_device *dp)
{
int lane, lane_count, retval;
u8 voltage_swing, pre_emphasis, training_lane;
u8 link_status[2], adjust_request[2];
usleep_range(100, 101);
lane_count = dp->link_train.lane_count;
retval = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status, 2);
if (retval < 0)
return retval;
retval = drm_dp_dpcd_read(&dp->aux, DP_ADJUST_REQUEST_LANE0_1,
adjust_request, 2);
if (retval < 0)
return retval;
if (analogix_dp_clock_recovery_ok(link_status, lane_count) == 0) {
/* set training pattern 2 for EQ */
analogix_dp_set_training_pattern(dp, TRAINING_PTN2);
retval = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
DP_LINK_SCRAMBLING_DISABLE |
DP_TRAINING_PATTERN_2);
if (retval < 0)
return retval;
dev_info(dp->dev, "Link Training Clock Recovery success\n");
dp->link_train.lt_state = EQUALIZER_TRAINING;
} else {
for (lane = 0; lane < lane_count; lane++) {
training_lane = analogix_dp_get_lane_link_training(
dp, lane);
voltage_swing = analogix_dp_get_adjust_request_voltage(
adjust_request, lane);
pre_emphasis = analogix_dp_get_adjust_request_pre_emphasis(
adjust_request, lane);
if (DPCD_VOLTAGE_SWING_GET(training_lane) ==
voltage_swing &&
DPCD_PRE_EMPHASIS_GET(training_lane) ==
pre_emphasis)
dp->link_train.cr_loop[lane]++;
if (dp->link_train.cr_loop[lane] == MAX_CR_LOOP ||
voltage_swing == VOLTAGE_LEVEL_3 ||
pre_emphasis == PRE_EMPHASIS_LEVEL_3) {
dev_err(dp->dev, "CR Max reached (%d,%d,%d)\n",
dp->link_train.cr_loop[lane],
voltage_swing, pre_emphasis);
analogix_dp_reduce_link_rate(dp);
return -EIO;
}
}
}
analogix_dp_get_adjust_training_lane(dp, adjust_request);
for (lane = 0; lane < lane_count; lane++)
analogix_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane], lane);
retval = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
dp->link_train.training_lane, lane_count);
if (retval < 0)
return retval;
return 0;
}
