Ejemplo n.º 1
0
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, &reg);
		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, &reg);
		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 
Ejemplo n.º 2
0
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;
}