static void exynos_dp_link_start(struct exynos_dp_device *dp)
{
u8 buf[5];
int lane;
int lane_count;
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 sink to D0 (Sink Not Ready) mode. */
exynos_dp_write_byte_to_dpcd(dp, DPCD_ADDR_SINK_POWER_STATE,
DPCD_SET_POWER_STATE_D0);
/* Set link rate and count as you want to establish*/
exynos_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
exynos_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;
exynos_dp_write_bytes_to_dpcd(dp, DPCD_ADDR_LINK_BW_SET,
2, buf);
/* Set TX pre-emphasis to minimum */
for (lane = 0; lane < lane_count; lane++)
exynos_dp_set_lane_lane_pre_emphasis(dp,
PRE_EMPHASIS_LEVEL_0, lane);
/* Set training pattern 1 */
exynos_dp_set_training_pattern(dp, TRAINING_PTN1);
/* Set RX training pattern */
buf[0] = DPCD_SCRAMBLING_DISABLED |
DPCD_TRAINING_PATTERN_1;
exynos_dp_write_byte_to_dpcd(dp,
DPCD_ADDR_TRAINING_PATTERN_SET, buf[0]);
for (lane = 0; lane < lane_count; lane++)
buf[lane] = DPCD_PRE_EMPHASIS_PATTERN2_LEVEL0 |
DPCD_VOLTAGE_SWING_PATTERN1_LEVEL0;
exynos_dp_write_bytes_to_dpcd(dp,
DPCD_ADDR_TRAINING_PATTERN_SET,
lane_count, buf);
}
static int exynos_dp_process_equalizer_training(struct exynos_dp_device *dp)
{
int lane, lane_count, retval;
u32 reg;
u8 link_align, link_status[2], adjust_request[2];
usleep_range(400, 401);
lane_count = dp->link_train.lane_count;
retval = exynos_dp_read_bytes_from_dpcd(dp,
DP_LANE0_1_STATUS, 2, link_status);
if (retval)
return retval;
if (exynos_dp_clock_recovery_ok(link_status, lane_count)) {
exynos_dp_reduce_link_rate(dp);
return -EIO;
}
retval = exynos_dp_read_bytes_from_dpcd(dp,
DP_ADJUST_REQUEST_LANE0_1, 2, adjust_request);
if (retval)
return retval;
retval = exynos_dp_read_byte_from_dpcd(dp,
DP_LANE_ALIGN_STATUS_UPDATED, &link_align);
if (retval)
return retval;
exynos_dp_get_adjust_training_lane(dp, adjust_request);
if (!exynos_dp_channel_eq_ok(link_status, link_align, lane_count)) {
/* traing pattern Set to Normal */
exynos_dp_training_pattern_dis(dp);
dev_info(dp->dev, "Link Training success!\n");
exynos_dp_get_link_bandwidth(dp, ®);
dp->link_train.link_rate = reg;
dev_dbg(dp->dev, "final bandwidth = %.2x\n",
dp->link_train.link_rate);
exynos_dp_get_lane_count(dp, ®);
dp->link_train.lane_count = reg;
dev_dbg(dp->dev, "final lane count = %.2x\n",
dp->link_train.lane_count);
/* set enhanced mode if available */
exynos_dp_set_enhanced_mode(dp);
dp->link_train.lt_state = FINISHED;
return 0;
}
/* not all locked */
dp->link_train.eq_loop++;
if (dp->link_train.eq_loop > MAX_EQ_LOOP) {
dev_err(dp->dev, "EQ Max loop\n");
exynos_dp_reduce_link_rate(dp);
return -EIO;
}
for (lane = 0; lane < lane_count; lane++)
exynos_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane], lane);
retval = exynos_dp_write_bytes_to_dpcd(dp, DP_TRAINING_LANE0_SET,
lane_count, dp->link_train.training_lane);
return retval;
}
static int exynos_dp_process_clock_recovery(struct exynos_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 = exynos_dp_read_bytes_from_dpcd(dp,
DP_LANE0_1_STATUS, 2, link_status);
if (retval)
return retval;
retval = exynos_dp_read_bytes_from_dpcd(dp,
DP_ADJUST_REQUEST_LANE0_1, 2, adjust_request);
if (retval)
return retval;
if (exynos_dp_clock_recovery_ok(link_status, lane_count) == 0) {
/* set training pattern 2 for EQ */
exynos_dp_set_training_pattern(dp, TRAINING_PTN2);
retval = exynos_dp_write_byte_to_dpcd(dp,
DP_TRAINING_PATTERN_SET,
DP_LINK_SCRAMBLING_DISABLE |
DP_TRAINING_PATTERN_2);
if (retval)
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 = exynos_dp_get_lane_link_training(
dp, lane);
voltage_swing = exynos_dp_get_adjust_request_voltage(
adjust_request, lane);
pre_emphasis = exynos_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);
exynos_dp_reduce_link_rate(dp);
return -EIO;
}
}
}
exynos_dp_get_adjust_training_lane(dp, adjust_request);
for (lane = 0; lane < lane_count; lane++)
exynos_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane], lane);
retval = exynos_dp_write_bytes_to_dpcd(dp,
DP_TRAINING_LANE0_SET, lane_count,
dp->link_train.training_lane);
if (retval)
return retval;
return retval;
}
static int exynos_dp_link_start(struct exynos_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*/
exynos_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
exynos_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 = exynos_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++)
exynos_dp_set_lane_lane_pre_emphasis(dp,
PRE_EMPHASIS_LEVEL_0, lane);
/* Wait for PLL lock */
pll_tries = 0;
while (exynos_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 */
exynos_dp_set_training_pattern(dp, TRAINING_PTN1);
/* Set RX training pattern */
retval = exynos_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 = exynos_dp_write_bytes_to_dpcd(dp, DP_TRAINING_LANE0_SET,
lane_count, buf);
return retval;
}
static int exynos_dp_process_equalizer_training(struct exynos_dp_device *dp)
{
u8 link_status[2];
u8 link_align[3];
int lane;
int lane_count;
u32 reg;
u8 adjust_request[2];
u8 voltage_swing;
u8 pre_emphasis;
u8 training_lane;
usleep_range(400, 401);
lane_count = dp->link_train.lane_count;
exynos_dp_read_bytes_from_dpcd(dp, DPCD_ADDR_LANE0_1_STATUS,
2, link_status);
if (exynos_dp_clock_recovery_ok(link_status, lane_count) == 0) {
link_align[0] = link_status[0];
link_align[1] = link_status[1];
exynos_dp_read_byte_from_dpcd(dp,
DPCD_ADDR_LANE_ALIGN_STATUS_UPDATED,
&link_align[2]);
for (lane = 0; lane < lane_count; lane++) {
exynos_dp_read_bytes_from_dpcd(dp,
DPCD_ADDR_ADJUST_REQUEST_LANE0_1,
2, adjust_request);
voltage_swing = exynos_dp_get_adjust_request_voltage(
adjust_request, lane);
pre_emphasis = exynos_dp_get_adjust_request_pre_emphasis(
adjust_request, lane);
training_lane = DPCD_VOLTAGE_SWING_SET(voltage_swing) |
DPCD_PRE_EMPHASIS_SET(pre_emphasis);
if (voltage_swing == VOLTAGE_LEVEL_3)
training_lane |= DPCD_MAX_SWING_REACHED;
if (pre_emphasis == PRE_EMPHASIS_LEVEL_3)
training_lane |= DPCD_MAX_PRE_EMPHASIS_REACHED;
dp->link_train.training_lane[lane] = training_lane;
}
if (exynos_dp_channel_eq_ok(link_align, lane_count) == 0) {
/* traing pattern Set to Normal */
exynos_dp_training_pattern_dis(dp);
dev_info(dp->dev, "Link Training success!\n");
exynos_dp_get_link_bandwidth(dp, ®);
dp->link_train.link_rate = reg;
dev_dbg(dp->dev, "final bandwidth = %.2x\n",
dp->link_train.link_rate);
exynos_dp_get_lane_count(dp, ®);
dp->link_train.lane_count = reg;
dev_dbg(dp->dev, "final lane count = %.2x\n",
dp->link_train.lane_count);
/* set enhanced mode if available */
exynos_dp_set_enhanced_mode(dp);
dp->link_train.lt_state = FINISHED;
} else {
/* not all locked */
dp->link_train.eq_loop++;
if (dp->link_train.eq_loop > MAX_EQ_LOOP) {
dev_err(dp->dev, "EQ Max loop\n");
goto reduce_link_rate;
}
for (lane = 0; lane < lane_count; lane++)
exynos_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane],
lane);
exynos_dp_write_bytes_to_dpcd(dp,
DPCD_ADDR_TRAINING_LANE0_SET,
lane_count,
dp->link_train.training_lane);
}
} else {
goto reduce_link_rate;
}
return 0;
reduce_link_rate:
exynos_dp_reduce_link_rate(dp);
return -EIO;
}
static int exynos_dp_process_clock_recovery(struct exynos_dp_device *dp)
{
u8 link_status[2];
int lane;
int lane_count;
u8 adjust_request[2];
u8 voltage_swing;
u8 pre_emphasis;
u8 training_lane;
usleep_range(100, 101);
lane_count = dp->link_train.lane_count;
exynos_dp_read_bytes_from_dpcd(dp, DPCD_ADDR_LANE0_1_STATUS,
2, link_status);
if (exynos_dp_clock_recovery_ok(link_status, lane_count) == 0) {
/* set training pattern 2 for EQ */
exynos_dp_set_training_pattern(dp, TRAINING_PTN2);
for (lane = 0; lane < lane_count; lane++) {
exynos_dp_read_bytes_from_dpcd(dp,
DPCD_ADDR_ADJUST_REQUEST_LANE0_1,
2, adjust_request);
voltage_swing = exynos_dp_get_adjust_request_voltage(
adjust_request, lane);
pre_emphasis = exynos_dp_get_adjust_request_pre_emphasis(
adjust_request, lane);
training_lane = DPCD_VOLTAGE_SWING_SET(voltage_swing) |
DPCD_PRE_EMPHASIS_SET(pre_emphasis);
if (voltage_swing == VOLTAGE_LEVEL_3)
training_lane |= DPCD_MAX_SWING_REACHED;
if (pre_emphasis == PRE_EMPHASIS_LEVEL_3)
training_lane |= DPCD_MAX_PRE_EMPHASIS_REACHED;
dp->link_train.training_lane[lane] = training_lane;
exynos_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane],
lane);
}
exynos_dp_write_byte_to_dpcd(dp,
DPCD_ADDR_TRAINING_PATTERN_SET,
DPCD_SCRAMBLING_DISABLED |
DPCD_TRAINING_PATTERN_2);
exynos_dp_write_bytes_to_dpcd(dp,
DPCD_ADDR_TRAINING_LANE0_SET,
lane_count,
dp->link_train.training_lane);
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 = exynos_dp_get_lane_link_training(
dp, lane);
exynos_dp_read_bytes_from_dpcd(dp,
DPCD_ADDR_ADJUST_REQUEST_LANE0_1,
2, adjust_request);
voltage_swing = exynos_dp_get_adjust_request_voltage(
adjust_request, lane);
pre_emphasis = exynos_dp_get_adjust_request_pre_emphasis(
adjust_request, lane);
if (voltage_swing == VOLTAGE_LEVEL_3 ||
pre_emphasis == PRE_EMPHASIS_LEVEL_3) {
dev_err(dp->dev, "voltage or pre emphasis reached max level\n");
goto reduce_link_rate;
}
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) {
dev_err(dp->dev, "CR Max loop\n");
goto reduce_link_rate;
}
}
training_lane = DPCD_VOLTAGE_SWING_SET(voltage_swing) |
DPCD_PRE_EMPHASIS_SET(pre_emphasis);
if (voltage_swing == VOLTAGE_LEVEL_3)
training_lane |= DPCD_MAX_SWING_REACHED;
if (pre_emphasis == PRE_EMPHASIS_LEVEL_3)
training_lane |= DPCD_MAX_PRE_EMPHASIS_REACHED;
dp->link_train.training_lane[lane] = training_lane;
exynos_dp_set_lane_link_training(dp,
dp->link_train.training_lane[lane], lane);
}
exynos_dp_write_bytes_to_dpcd(dp,
DPCD_ADDR_TRAINING_LANE0_SET,
lane_count,
dp->link_train.training_lane);
}
return 0;
reduce_link_rate:
exynos_dp_reduce_link_rate(dp);
return -EIO;
}
