drm/radeon/kms: add support for DP modesetting

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 488 insertions, 53 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 76eb5c8..ebaf3f8 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -31,9 +31,20 @@
 #include "atom-bits.h"
 #include "drm_dp_helper.h"
 
-#define DP_LINK_STATUS_SIZE	6
-
 /* move these to drm_dp_helper.c/h */
+#define DP_LINK_CONFIGURATION_SIZE 9
+#define DP_LINK_STATUS_SIZE	   6
+#define DP_DPCD_SIZE	           8
+
+static char *voltage_names[] = {
+        "0.4V", "0.6V", "0.8V", "1.2V"
+};
+static char *pre_emph_names[] = {
+        "0dB", "3.5dB", "6dB", "9.5dB"
+};
+static char *link_train_names[] = {
+        "pattern 1", "pattern 2", "idle", "off"
+};
 
 static const int dp_clocks[] = {
 	54000,  // 1 lane, 1.62 Ghz
@@ -46,9 +57,18 @@ static const int dp_clocks[] = {
 
 static const int num_dp_clocks = sizeof(dp_clocks) / sizeof(int);
 
-int dp_lanes_for_mode_clock(int max_link_bw, int mode_clock)
+/* common helper functions */
+static int dp_lanes_for_mode_clock(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
 {
 	int i;
+	u8 max_link_bw;
+	u8 max_lane_count;
+
+	if (!dpcd)
+		return 0;
+
+	max_link_bw = dpcd[DP_MAX_LINK_RATE];
+	max_lane_count = dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
 
 	switch (max_link_bw) {
 	case DP_LINK_BW_1_62:
@@ -56,6 +76,19 @@ int dp_lanes_for_mode_clock(int max_link_bw, int mode_clock)
 		for (i = 0; i < num_dp_clocks; i++) {
 			if (i % 2)
 				continue;
+			switch (max_lane_count) {
+			case 1:
+				if (i > 1)
+					return 0;
+				break;
+			case 2:
+				if (i > 3)
+					return 0;
+				break;
+			case 4:
+			default:
+				break;
+			}
 			if (dp_clocks[i] > mode_clock) {
 				if (i < 2)
 					return 1;
@@ -68,6 +101,19 @@ int dp_lanes_for_mode_clock(int max_link_bw, int mode_clock)
 		break;
 	case DP_LINK_BW_2_7:
 		for (i = 0; i < num_dp_clocks; i++) {
+			switch (max_lane_count) {
+			case 1:
+				if (i > 1)
+					return 0;
+				break;
+			case 2:
+				if (i > 3)
+					return 0;
+				break;
+			case 4:
+			default:
+				break;
+			}
 			if (dp_clocks[i] > mode_clock) {
 				if (i < 2)
 					return 1;
@@ -83,17 +129,56 @@ int dp_lanes_for_mode_clock(int max_link_bw, int mode_clock)
 	return 0;
 }
 
-int dp_link_clock_for_mode_clock(int max_link_bw, int mode_clock)
+static int dp_link_clock_for_mode_clock(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
 {
 	int i;
+	u8 max_link_bw;
+	u8 max_lane_count;
+
+	if (!dpcd)
+		return 0;
+
+	max_link_bw = dpcd[DP_MAX_LINK_RATE];
+	max_lane_count = dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
 
 	switch (max_link_bw) {
 	case DP_LINK_BW_1_62:
 	default:
-		return 162000;
+		for (i = 0; i < num_dp_clocks; i++) {
+			if (i % 2)
+				continue;
+			switch (max_lane_count) {
+			case 1:
+				if (i > 1)
+					return 0;
+				break;
+			case 2:
+				if (i > 3)
+					return 0;
+				break;
+			case 4:
+			default:
+				break;
+			}
+			if (dp_clocks[i] > mode_clock)
+				return 162000;
+		}
 		break;
 	case DP_LINK_BW_2_7:
 		for (i = 0; i < num_dp_clocks; i++) {
+			switch (max_lane_count) {
+			case 1:
+				if (i > 1)
+					return 0;
+				break;
+			case 2:
+				if (i > 3)
+					return 0;
+				break;
+			case 4:
+			default:
+				break;
+			}
 			if (dp_clocks[i] > mode_clock)
 				return (i % 2) ? 270000 : 162000;
 		}
@@ -102,6 +187,145 @@ int dp_link_clock_for_mode_clock(int max_link_bw, int mode_clock)
 	return 0;
 }
 
+int dp_mode_valid(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
+{
+	int lanes = dp_lanes_for_mode_clock(dpcd, mode_clock);
+	int bw = dp_lanes_for_mode_clock(dpcd, mode_clock);
+
+	if ((lanes == 0) || (bw == 0))
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
+static u8 dp_link_status(u8 link_status[DP_LINK_STATUS_SIZE], int r)
+{
+	return link_status[r - DP_LANE0_1_STATUS];
+}
+
+static u8 dp_get_lane_status(u8 link_status[DP_LINK_STATUS_SIZE],
+			     int lane)
+{
+	int i = DP_LANE0_1_STATUS + (lane >> 1);
+	int s = (lane & 1) * 4;
+	u8 l = dp_link_status(link_status, i);
+	return (l >> s) & 0xf;
+}
+
+static bool dp_clock_recovery_ok(u8 link_status[DP_LINK_STATUS_SIZE],
+				 int lane_count)
+{
+	int lane;
+	u8 lane_status;
+
+	for (lane = 0; lane < lane_count; lane++) {
+		lane_status = dp_get_lane_status(link_status, lane);
+		if ((lane_status & DP_LANE_CR_DONE) == 0)
+			return false;
+	}
+	return true;
+}
+
+static bool dp_channel_eq_ok(u8 link_status[DP_LINK_STATUS_SIZE],
+			     int lane_count)
+{
+	u8 lane_align;
+	u8 lane_status;
+	int lane;
+
+	lane_align = dp_link_status(link_status,
+				    DP_LANE_ALIGN_STATUS_UPDATED);
+	if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
+		return false;
+	for (lane = 0; lane < lane_count; lane++) {
+		lane_status = dp_get_lane_status(link_status, lane);
+		if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
+			return false;
+	}
+	return true;
+}
+
+static u8 dp_get_adjust_request_voltage(uint8_t link_status[DP_LINK_STATUS_SIZE],
+					int lane)
+
+{
+	int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
+	int s = ((lane & 1) ?
+		 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
+		 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
+	u8 l = dp_link_status(link_status, i);
+
+	return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
+}
+
+static u8 dp_get_adjust_request_pre_emphasis(uint8_t link_status[DP_LINK_STATUS_SIZE],
+					     int lane)
+{
+	int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
+	int s = ((lane & 1) ?
+		 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
+		 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
+	u8 l = dp_link_status(link_status, i);
+
+	return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
+}
+
+/* XXX fix me -- chip specific */
+#define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_1200
+static u8 dp_pre_emphasis_max(u8 voltage_swing)
+{
+	switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+	case DP_TRAIN_VOLTAGE_SWING_400:
+		return DP_TRAIN_PRE_EMPHASIS_6;
+	case DP_TRAIN_VOLTAGE_SWING_600:
+		return DP_TRAIN_PRE_EMPHASIS_6;
+	case DP_TRAIN_VOLTAGE_SWING_800:
+		return DP_TRAIN_PRE_EMPHASIS_3_5;
+	case DP_TRAIN_VOLTAGE_SWING_1200:
+	default:
+		return DP_TRAIN_PRE_EMPHASIS_0;
+	}
+}
+
+static void dp_get_adjust_train(u8 link_status[DP_LINK_STATUS_SIZE],
+				int lane_count,
+				u8 train_set[4])
+{
+	u8 v = 0;
+	u8 p = 0;
+	int lane;
+
+	for (lane = 0; lane < lane_count; lane++) {
+		u8 this_v = dp_get_adjust_request_voltage(link_status, lane);
+		u8 this_p = dp_get_adjust_request_pre_emphasis(link_status, lane);
+
+		DRM_INFO("requested signal parameters: lane %d voltage %s pre_emph %s\n",
+			 lane,
+			 voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
+			 pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
+
+		if (this_v > v)
+			v = this_v;
+		if (this_p > p)
+			p = this_p;
+	}
+
+	if (v >= DP_VOLTAGE_MAX)
+		v = DP_VOLTAGE_MAX | DP_TRAIN_MAX_SWING_REACHED;
+
+	if (p >= dp_pre_emphasis_max(v))
+		p = dp_pre_emphasis_max(v) | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
+
+	DRM_INFO("using signal parameters: voltage %s pre_emph %s\n",
+		 voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
+		 pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
+
+	for (lane = 0; lane < 4; lane++)
+		train_set[lane] = v | p;
+}
+
+
+/* radeon aux chan functions */
 bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
 			   int num_bytes, u8 *read_byte,
 			   u8 read_buf_len, u8 delay)
@@ -147,44 +371,10 @@ bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
 	return true;
 }
 
-static u8 radeon_dp_encoder_service(struct radeon_device *rdev, int action, int dp_clock,
-				    uint8_t ucconfig, uint8_t lane_num)
-{
-	DP_ENCODER_SERVICE_PARAMETERS args;
-	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
-
-	memset(&args, 0, sizeof(args));
-	args.ucLinkClock = dp_clock / 10;
-	args.ucConfig = ucconfig;
-	args.ucAction = action;
-	args.ucLaneNum = lane_num;
-	args.ucStatus = 0;
-
-	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
-	return args.ucStatus;
-}
-
-u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
-{
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
-	struct drm_device *dev = radeon_connector->base.dev;
-	struct radeon_device *rdev = dev->dev_private;
-
-	return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
-					 radeon_dig_connector->dp_i2c_bus->rec.i2c_id, 0);
-}
-
-union dig_transmitter_control {
-	DIG_TRANSMITTER_CONTROL_PS_ALLOCATION v1;
-	DIG_TRANSMITTER_CONTROL_PARAMETERS_V2 v2;
-};
-
 bool radeon_dp_aux_native_write(struct radeon_connector *radeon_connector, uint16_t address,
 				uint8_t send_bytes, uint8_t *send)
 {
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
-	struct drm_device *dev = radeon_connector->base.dev;
-	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
 	u8 msg[20];
 	u8 msg_len, dp_msg_len;
 	bool ret;
@@ -201,7 +391,7 @@ bool radeon_dp_aux_native_write(struct radeon_connector *radeon_connector, uint1
 
 	memcpy(&msg[4], send, send_bytes);
 	msg_len = 4 + send_bytes;
-	ret = radeon_process_aux_ch(radeon_dig_connector->dp_i2c_bus, msg, msg_len, NULL, 0, 0);
+	ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, NULL, 0, 0);
 	return ret;
 }
 
@@ -209,9 +399,7 @@ bool radeon_dp_aux_native_read(struct radeon_connector *radeon_connector, uint16
 			       uint8_t delay, uint8_t expected_bytes,
 			       uint8_t *read_p)
 {
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
-	struct drm_device *dev = radeon_connector->base.dev;
-	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
 	u8 msg[20];
 	u8 msg_len, dp_msg_len;
 	bool ret = false;
@@ -223,19 +411,47 @@ bool radeon_dp_aux_native_read(struct radeon_connector *radeon_connector, uint16
 	msg[3] = (dp_msg_len) << 4;
 	msg[3] |= expected_bytes - 1;
 
-	ret = radeon_process_aux_ch(radeon_dig_connector->dp_i2c_bus, msg, msg_len, read_p, expected_bytes, delay);
+	ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, read_p, expected_bytes, delay);
 	return ret;
 }
 
+/* radeon dp functions */
+static u8 radeon_dp_encoder_service(struct radeon_device *rdev, int action, int dp_clock,
+				    uint8_t ucconfig, uint8_t lane_num)
+{
+	DP_ENCODER_SERVICE_PARAMETERS args;
+	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
+
+	memset(&args, 0, sizeof(args));
+	args.ucLinkClock = dp_clock / 10;
+	args.ucConfig = ucconfig;
+	args.ucAction = action;
+	args.ucLaneNum = lane_num;
+	args.ucStatus = 0;
+
+	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+	return args.ucStatus;
+}
+
+u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
+{
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+	struct drm_device *dev = radeon_connector->base.dev;
+	struct radeon_device *rdev = dev->dev_private;
+
+	return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
+					 dig_connector->dp_i2c_bus->rec.i2c_id, 0);
+}
+
 void radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
 {
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
 	u8 msg[25];
 	int ret;
 
 	ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, 0, 8, msg);
 	if (ret) {
-		memcpy(radeon_dig_connector->dpcd, msg, 8);
+		memcpy(dig_connector->dpcd, msg, 8);
 		{
 			int i;
 			printk("DPCD: ");
@@ -244,10 +460,38 @@ void radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
 			printk("\n");
 		}
 	}
-	radeon_dig_connector->dpcd[0] = 0;
+	dig_connector->dpcd[0] = 0;
 	return;
 }
 
+void radeon_dp_set_link_config(struct drm_connector *connector,
+			       struct drm_display_mode *mode)
+{
+	struct radeon_connector *radeon_connector;
+	struct radeon_connector_atom_dig *dig_connector;
+
+	if (connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort)
+		return;
+
+	radeon_connector = to_radeon_connector(connector);
+	if (!radeon_connector->con_priv)
+		return;
+	dig_connector = radeon_connector->con_priv;
+
+	dig_connector->dp_clock =
+		dp_link_clock_for_mode_clock(dig_connector->dpcd, mode->clock);
+	dig_connector->dp_lane_count =
+		dp_lanes_for_mode_clock(dig_connector->dpcd, mode->clock);
+}
+
+int radeon_dp_mode_valid_helper(struct radeon_connector *radeon_connector,
+				struct drm_display_mode *mode)
+{
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+
+	return dp_mode_valid(dig_connector->dpcd, mode->clock);
+}
+
 static bool atom_dp_get_link_status(struct radeon_connector *radeon_connector,
 				    u8 link_status[DP_LINK_STATUS_SIZE])
 {
@@ -267,21 +511,41 @@ static bool atom_dp_get_link_status(struct radeon_connector *radeon_connector,
 
 static void dp_set_power(struct radeon_connector *radeon_connector, u8 power_state)
 {
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
-	if (radeon_dig_connector->dpcd[0] >= 0x11) {
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+
+	if (dig_connector->dpcd[0] >= 0x11) {
 		radeon_dp_aux_native_write(radeon_connector, DP_SET_POWER, 1,
 					   &power_state);
 	}
 }
 
+static void dp_set_downspread(struct radeon_connector *radeon_connector, u8 downspread)
+{
+	radeon_dp_aux_native_write(radeon_connector, DP_DOWNSPREAD_CTRL, 1,
+				   &downspread);
+}
+
+static void dp_set_link_bw_lanes(struct radeon_connector *radeon_connector,
+				 u8 link_configuration[DP_LINK_CONFIGURATION_SIZE])
+{
+	radeon_dp_aux_native_write(radeon_connector, DP_LINK_BW_SET, 2,
+				   link_configuration);
+}
+
 static void dp_update_dpvs_emph(struct radeon_connector *radeon_connector,
+				struct drm_encoder *encoder,
 				u8 train_set[4])
 {
-	struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+	int i;
+
+	for (i = 0; i < dig_connector->dp_lane_count; i++)
+		atombios_dig_transmitter_setup(encoder,
+					       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
+					       i, train_set[i]);
 
-//	radeon_dp_digtransmitter_setup_vsemph();
 	radeon_dp_aux_native_write(radeon_connector, DP_TRAINING_LANE0_SET,
-				   0/* lc */, train_set);
+				   dig_connector->dp_lane_count, train_set);
 }
 
 static void dp_set_training(struct radeon_connector *radeon_connector,
@@ -291,6 +555,176 @@ static void dp_set_training(struct radeon_connector *radeon_connector,
 				   1, &training);
 }
 
+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)
+		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 (ASIC_IS_DCE32(rdev)) {
+		if (dig->dig_block)
+			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;
+	} else {
+		if (dig_connector->linkb)
+			enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER | ATOM_DP_CONFIG_LINK_B;
+		else
+			enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER | 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);
+	dp_update_dpvs_emph(radeon_connector, encoder, train_set);
+	udelay(400);
+	/* set training pattern 1 on the sink */
+	dp_set_training(radeon_connector, DP_TRAINING_PATTERN_1);
+
+	/* 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_INFO("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_INFO("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);
+}
+
 int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 			 uint8_t write_byte, uint8_t *read_byte)
 {
@@ -342,3 +776,4 @@ int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 	}
 	return -EREMOTEIO;
 }
+