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_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;
}
