xref: /openbmc/linux/drivers/gpu/drm/radeon/atombios_dp.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Copyright 2007-8 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors: Dave Airlie
24  *          Alex Deucher
25  */
26 #include "drmP.h"
27 #include "radeon_drm.h"
28 #include "radeon.h"
29 
30 #include "atom.h"
31 #include "atom-bits.h"
32 #include "drm_dp_helper.h"
33 
34 /* move these to drm_dp_helper.c/h */
35 #define DP_LINK_CONFIGURATION_SIZE 9
36 #define DP_LINK_STATUS_SIZE	   6
37 #define DP_DPCD_SIZE	           8
38 
39 static char *voltage_names[] = {
40         "0.4V", "0.6V", "0.8V", "1.2V"
41 };
42 static char *pre_emph_names[] = {
43         "0dB", "3.5dB", "6dB", "9.5dB"
44 };
45 
46 static const int dp_clocks[] = {
47 	54000,  /* 1 lane, 1.62 Ghz */
48 	90000,  /* 1 lane, 2.70 Ghz */
49 	108000, /* 2 lane, 1.62 Ghz */
50 	180000, /* 2 lane, 2.70 Ghz */
51 	216000, /* 4 lane, 1.62 Ghz */
52 	360000, /* 4 lane, 2.70 Ghz */
53 };
54 
55 static const int num_dp_clocks = sizeof(dp_clocks) / sizeof(int);
56 
57 /* common helper functions */
58 static int dp_lanes_for_mode_clock(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
59 {
60 	int i;
61 	u8 max_link_bw;
62 	u8 max_lane_count;
63 
64 	if (!dpcd)
65 		return 0;
66 
67 	max_link_bw = dpcd[DP_MAX_LINK_RATE];
68 	max_lane_count = dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
69 
70 	switch (max_link_bw) {
71 	case DP_LINK_BW_1_62:
72 	default:
73 		for (i = 0; i < num_dp_clocks; i++) {
74 			if (i % 2)
75 				continue;
76 			switch (max_lane_count) {
77 			case 1:
78 				if (i > 1)
79 					return 0;
80 				break;
81 			case 2:
82 				if (i > 3)
83 					return 0;
84 				break;
85 			case 4:
86 			default:
87 				break;
88 			}
89 			if (dp_clocks[i] > mode_clock) {
90 				if (i < 2)
91 					return 1;
92 				else if (i < 4)
93 					return 2;
94 				else
95 					return 4;
96 			}
97 		}
98 		break;
99 	case DP_LINK_BW_2_7:
100 		for (i = 0; i < num_dp_clocks; i++) {
101 			switch (max_lane_count) {
102 			case 1:
103 				if (i > 1)
104 					return 0;
105 				break;
106 			case 2:
107 				if (i > 3)
108 					return 0;
109 				break;
110 			case 4:
111 			default:
112 				break;
113 			}
114 			if (dp_clocks[i] > mode_clock) {
115 				if (i < 2)
116 					return 1;
117 				else if (i < 4)
118 					return 2;
119 				else
120 					return 4;
121 			}
122 		}
123 		break;
124 	}
125 
126 	return 0;
127 }
128 
129 static int dp_link_clock_for_mode_clock(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
130 {
131 	int i;
132 	u8 max_link_bw;
133 	u8 max_lane_count;
134 
135 	if (!dpcd)
136 		return 0;
137 
138 	max_link_bw = dpcd[DP_MAX_LINK_RATE];
139 	max_lane_count = dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
140 
141 	switch (max_link_bw) {
142 	case DP_LINK_BW_1_62:
143 	default:
144 		for (i = 0; i < num_dp_clocks; i++) {
145 			if (i % 2)
146 				continue;
147 			switch (max_lane_count) {
148 			case 1:
149 				if (i > 1)
150 					return 0;
151 				break;
152 			case 2:
153 				if (i > 3)
154 					return 0;
155 				break;
156 			case 4:
157 			default:
158 				break;
159 			}
160 			if (dp_clocks[i] > mode_clock)
161 				return 162000;
162 		}
163 		break;
164 	case DP_LINK_BW_2_7:
165 		for (i = 0; i < num_dp_clocks; i++) {
166 			switch (max_lane_count) {
167 			case 1:
168 				if (i > 1)
169 					return 0;
170 				break;
171 			case 2:
172 				if (i > 3)
173 					return 0;
174 				break;
175 			case 4:
176 			default:
177 				break;
178 			}
179 			if (dp_clocks[i] > mode_clock)
180 				return (i % 2) ? 270000 : 162000;
181 		}
182 	}
183 
184 	return 0;
185 }
186 
187 int dp_mode_valid(u8 dpcd[DP_DPCD_SIZE], int mode_clock)
188 {
189 	int lanes = dp_lanes_for_mode_clock(dpcd, mode_clock);
190 	int dp_clock = dp_link_clock_for_mode_clock(dpcd, mode_clock);
191 
192 	if ((lanes == 0) || (dp_clock == 0))
193 		return MODE_CLOCK_HIGH;
194 
195 	return MODE_OK;
196 }
197 
198 static u8 dp_link_status(u8 link_status[DP_LINK_STATUS_SIZE], int r)
199 {
200 	return link_status[r - DP_LANE0_1_STATUS];
201 }
202 
203 static u8 dp_get_lane_status(u8 link_status[DP_LINK_STATUS_SIZE],
204 			     int lane)
205 {
206 	int i = DP_LANE0_1_STATUS + (lane >> 1);
207 	int s = (lane & 1) * 4;
208 	u8 l = dp_link_status(link_status, i);
209 	return (l >> s) & 0xf;
210 }
211 
212 static bool dp_clock_recovery_ok(u8 link_status[DP_LINK_STATUS_SIZE],
213 				 int lane_count)
214 {
215 	int lane;
216 	u8 lane_status;
217 
218 	for (lane = 0; lane < lane_count; lane++) {
219 		lane_status = dp_get_lane_status(link_status, lane);
220 		if ((lane_status & DP_LANE_CR_DONE) == 0)
221 			return false;
222 	}
223 	return true;
224 }
225 
226 static bool dp_channel_eq_ok(u8 link_status[DP_LINK_STATUS_SIZE],
227 			     int lane_count)
228 {
229 	u8 lane_align;
230 	u8 lane_status;
231 	int lane;
232 
233 	lane_align = dp_link_status(link_status,
234 				    DP_LANE_ALIGN_STATUS_UPDATED);
235 	if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
236 		return false;
237 	for (lane = 0; lane < lane_count; lane++) {
238 		lane_status = dp_get_lane_status(link_status, lane);
239 		if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
240 			return false;
241 	}
242 	return true;
243 }
244 
245 static u8 dp_get_adjust_request_voltage(uint8_t link_status[DP_LINK_STATUS_SIZE],
246 					int lane)
247 
248 {
249 	int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
250 	int s = ((lane & 1) ?
251 		 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
252 		 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
253 	u8 l = dp_link_status(link_status, i);
254 
255 	return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
256 }
257 
258 static u8 dp_get_adjust_request_pre_emphasis(uint8_t link_status[DP_LINK_STATUS_SIZE],
259 					     int lane)
260 {
261 	int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
262 	int s = ((lane & 1) ?
263 		 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
264 		 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
265 	u8 l = dp_link_status(link_status, i);
266 
267 	return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
268 }
269 
270 /* XXX fix me -- chip specific */
271 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_1200
272 static u8 dp_pre_emphasis_max(u8 voltage_swing)
273 {
274 	switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
275 	case DP_TRAIN_VOLTAGE_SWING_400:
276 		return DP_TRAIN_PRE_EMPHASIS_6;
277 	case DP_TRAIN_VOLTAGE_SWING_600:
278 		return DP_TRAIN_PRE_EMPHASIS_6;
279 	case DP_TRAIN_VOLTAGE_SWING_800:
280 		return DP_TRAIN_PRE_EMPHASIS_3_5;
281 	case DP_TRAIN_VOLTAGE_SWING_1200:
282 	default:
283 		return DP_TRAIN_PRE_EMPHASIS_0;
284 	}
285 }
286 
287 static void dp_get_adjust_train(u8 link_status[DP_LINK_STATUS_SIZE],
288 				int lane_count,
289 				u8 train_set[4])
290 {
291 	u8 v = 0;
292 	u8 p = 0;
293 	int lane;
294 
295 	for (lane = 0; lane < lane_count; lane++) {
296 		u8 this_v = dp_get_adjust_request_voltage(link_status, lane);
297 		u8 this_p = dp_get_adjust_request_pre_emphasis(link_status, lane);
298 
299 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
300 			  lane,
301 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
302 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
303 
304 		if (this_v > v)
305 			v = this_v;
306 		if (this_p > p)
307 			p = this_p;
308 	}
309 
310 	if (v >= DP_VOLTAGE_MAX)
311 		v = DP_VOLTAGE_MAX | DP_TRAIN_MAX_SWING_REACHED;
312 
313 	if (p >= dp_pre_emphasis_max(v))
314 		p = dp_pre_emphasis_max(v) | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
315 
316 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
317 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
318 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
319 
320 	for (lane = 0; lane < 4; lane++)
321 		train_set[lane] = v | p;
322 }
323 
324 union aux_channel_transaction {
325 	PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
326 	PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
327 };
328 
329 /* radeon aux chan functions */
330 bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
331 			   int num_bytes, u8 *read_byte,
332 			   u8 read_buf_len, u8 delay)
333 {
334 	struct drm_device *dev = chan->dev;
335 	struct radeon_device *rdev = dev->dev_private;
336 	union aux_channel_transaction args;
337 	int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
338 	unsigned char *base;
339 	int retry_count = 0;
340 
341 	memset(&args, 0, sizeof(args));
342 
343 	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
344 
345 retry:
346 	memcpy(base, req_bytes, num_bytes);
347 
348 	args.v1.lpAuxRequest = 0;
349 	args.v1.lpDataOut = 16;
350 	args.v1.ucDataOutLen = 0;
351 	args.v1.ucChannelID = chan->rec.i2c_id;
352 	args.v1.ucDelay = delay / 10;
353 	if (ASIC_IS_DCE4(rdev))
354 		args.v2.ucHPD_ID = chan->rec.hpd;
355 
356 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
357 
358 	if (args.v1.ucReplyStatus && !args.v1.ucDataOutLen) {
359 		if (args.v1.ucReplyStatus == 0x20 && retry_count++ < 10)
360 			goto retry;
361 		DRM_DEBUG_KMS("failed to get auxch %02x%02x %02x %02x 0x%02x %02x after %d retries\n",
362 			  req_bytes[1], req_bytes[0], req_bytes[2], req_bytes[3],
363 			  chan->rec.i2c_id, args.v1.ucReplyStatus, retry_count);
364 		return false;
365 	}
366 
367 	if (args.v1.ucDataOutLen && read_byte && read_buf_len) {
368 		if (read_buf_len < args.v1.ucDataOutLen) {
369 			DRM_ERROR("Buffer to small for return answer %d %d\n",
370 				  read_buf_len, args.v1.ucDataOutLen);
371 			return false;
372 		}
373 		{
374 			int len = min(read_buf_len, args.v1.ucDataOutLen);
375 			memcpy(read_byte, base + 16, len);
376 		}
377 	}
378 	return true;
379 }
380 
381 bool radeon_dp_aux_native_write(struct radeon_connector *radeon_connector, uint16_t address,
382 				uint8_t send_bytes, uint8_t *send)
383 {
384 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
385 	u8 msg[20];
386 	u8 msg_len, dp_msg_len;
387 	bool ret;
388 
389 	dp_msg_len = 4;
390 	msg[0] = address;
391 	msg[1] = address >> 8;
392 	msg[2] = AUX_NATIVE_WRITE << 4;
393 	dp_msg_len += send_bytes;
394 	msg[3] = (dp_msg_len << 4) | (send_bytes - 1);
395 
396 	if (send_bytes > 16)
397 		return false;
398 
399 	memcpy(&msg[4], send, send_bytes);
400 	msg_len = 4 + send_bytes;
401 	ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, NULL, 0, 0);
402 	return ret;
403 }
404 
405 bool radeon_dp_aux_native_read(struct radeon_connector *radeon_connector, uint16_t address,
406 			       uint8_t delay, uint8_t expected_bytes,
407 			       uint8_t *read_p)
408 {
409 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
410 	u8 msg[20];
411 	u8 msg_len, dp_msg_len;
412 	bool ret = false;
413 	msg_len = 4;
414 	dp_msg_len = 4;
415 	msg[0] = address;
416 	msg[1] = address >> 8;
417 	msg[2] = AUX_NATIVE_READ << 4;
418 	msg[3] = (dp_msg_len) << 4;
419 	msg[3] |= expected_bytes - 1;
420 
421 	ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_len, read_p, expected_bytes, delay);
422 	return ret;
423 }
424 
425 /* radeon dp functions */
426 static u8 radeon_dp_encoder_service(struct radeon_device *rdev, int action, int dp_clock,
427 				    uint8_t ucconfig, uint8_t lane_num)
428 {
429 	DP_ENCODER_SERVICE_PARAMETERS args;
430 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
431 
432 	memset(&args, 0, sizeof(args));
433 	args.ucLinkClock = dp_clock / 10;
434 	args.ucConfig = ucconfig;
435 	args.ucAction = action;
436 	args.ucLaneNum = lane_num;
437 	args.ucStatus = 0;
438 
439 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
440 	return args.ucStatus;
441 }
442 
443 u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
444 {
445 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
446 	struct drm_device *dev = radeon_connector->base.dev;
447 	struct radeon_device *rdev = dev->dev_private;
448 
449 	return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
450 					 dig_connector->dp_i2c_bus->rec.i2c_id, 0);
451 }
452 
453 bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
454 {
455 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
456 	u8 msg[25];
457 	int ret;
458 
459 	ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, 0, 8, msg);
460 	if (ret) {
461 		memcpy(dig_connector->dpcd, msg, 8);
462 		{
463 			int i;
464 			DRM_DEBUG_KMS("DPCD: ");
465 			for (i = 0; i < 8; i++)
466 				DRM_DEBUG_KMS("%02x ", msg[i]);
467 			DRM_DEBUG_KMS("\n");
468 		}
469 		return true;
470 	}
471 	dig_connector->dpcd[0] = 0;
472 	return false;
473 }
474 
475 void radeon_dp_set_link_config(struct drm_connector *connector,
476 			       struct drm_display_mode *mode)
477 {
478 	struct radeon_connector *radeon_connector;
479 	struct radeon_connector_atom_dig *dig_connector;
480 
481 	if ((connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort) &&
482 	    (connector->connector_type != DRM_MODE_CONNECTOR_eDP))
483 		return;
484 
485 	radeon_connector = to_radeon_connector(connector);
486 	if (!radeon_connector->con_priv)
487 		return;
488 	dig_connector = radeon_connector->con_priv;
489 
490 	dig_connector->dp_clock =
491 		dp_link_clock_for_mode_clock(dig_connector->dpcd, mode->clock);
492 	dig_connector->dp_lane_count =
493 		dp_lanes_for_mode_clock(dig_connector->dpcd, mode->clock);
494 }
495 
496 int radeon_dp_mode_valid_helper(struct radeon_connector *radeon_connector,
497 				struct drm_display_mode *mode)
498 {
499 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
500 
501 	return dp_mode_valid(dig_connector->dpcd, mode->clock);
502 }
503 
504 static bool atom_dp_get_link_status(struct radeon_connector *radeon_connector,
505 				    u8 link_status[DP_LINK_STATUS_SIZE])
506 {
507 	int ret;
508 	ret = radeon_dp_aux_native_read(radeon_connector, DP_LANE0_1_STATUS, 100,
509 					DP_LINK_STATUS_SIZE, link_status);
510 	if (!ret) {
511 		DRM_ERROR("displayport link status failed\n");
512 		return false;
513 	}
514 
515 	DRM_DEBUG_KMS("link status %02x %02x %02x %02x %02x %02x\n",
516 		  link_status[0], link_status[1], link_status[2],
517 		  link_status[3], link_status[4], link_status[5]);
518 	return true;
519 }
520 
521 bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
522 {
523 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
524 	u8 link_status[DP_LINK_STATUS_SIZE];
525 
526 	if (!atom_dp_get_link_status(radeon_connector, link_status))
527 		return false;
528 	if (dp_channel_eq_ok(link_status, dig_connector->dp_lane_count))
529 		return false;
530 	return true;
531 }
532 
533 static void dp_set_power(struct radeon_connector *radeon_connector, u8 power_state)
534 {
535 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
536 
537 	if (dig_connector->dpcd[0] >= 0x11) {
538 		radeon_dp_aux_native_write(radeon_connector, DP_SET_POWER, 1,
539 					   &power_state);
540 	}
541 }
542 
543 static void dp_set_downspread(struct radeon_connector *radeon_connector, u8 downspread)
544 {
545 	radeon_dp_aux_native_write(radeon_connector, DP_DOWNSPREAD_CTRL, 1,
546 				   &downspread);
547 }
548 
549 static void dp_set_link_bw_lanes(struct radeon_connector *radeon_connector,
550 				 u8 link_configuration[DP_LINK_CONFIGURATION_SIZE])
551 {
552 	radeon_dp_aux_native_write(radeon_connector, DP_LINK_BW_SET, 2,
553 				   link_configuration);
554 }
555 
556 static void dp_update_dpvs_emph(struct radeon_connector *radeon_connector,
557 				struct drm_encoder *encoder,
558 				u8 train_set[4])
559 {
560 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
561 	int i;
562 
563 	for (i = 0; i < dig_connector->dp_lane_count; i++)
564 		atombios_dig_transmitter_setup(encoder,
565 					       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
566 					       i, train_set[i]);
567 
568 	radeon_dp_aux_native_write(radeon_connector, DP_TRAINING_LANE0_SET,
569 				   dig_connector->dp_lane_count, train_set);
570 }
571 
572 static void dp_set_training(struct radeon_connector *radeon_connector,
573 			    u8 training)
574 {
575 	radeon_dp_aux_native_write(radeon_connector, DP_TRAINING_PATTERN_SET,
576 				   1, &training);
577 }
578 
579 void dp_link_train(struct drm_encoder *encoder,
580 		   struct drm_connector *connector)
581 {
582 	struct drm_device *dev = encoder->dev;
583 	struct radeon_device *rdev = dev->dev_private;
584 	struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
585 	struct radeon_encoder_atom_dig *dig;
586 	struct radeon_connector *radeon_connector;
587 	struct radeon_connector_atom_dig *dig_connector;
588 	int enc_id = 0;
589 	bool clock_recovery, channel_eq;
590 	u8 link_status[DP_LINK_STATUS_SIZE];
591 	u8 link_configuration[DP_LINK_CONFIGURATION_SIZE];
592 	u8 tries, voltage;
593 	u8 train_set[4];
594 	int i;
595 
596 	if ((connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort) &&
597 	    (connector->connector_type != DRM_MODE_CONNECTOR_eDP))
598 		return;
599 
600 	if (!radeon_encoder->enc_priv)
601 		return;
602 	dig = radeon_encoder->enc_priv;
603 
604 	radeon_connector = to_radeon_connector(connector);
605 	if (!radeon_connector->con_priv)
606 		return;
607 	dig_connector = radeon_connector->con_priv;
608 
609 	if (dig->dig_encoder)
610 		enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;
611 	else
612 		enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER;
613 	if (dig->linkb)
614 		enc_id |= ATOM_DP_CONFIG_LINK_B;
615 	else
616 		enc_id |= ATOM_DP_CONFIG_LINK_A;
617 
618 	memset(link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
619 	if (dig_connector->dp_clock == 270000)
620 		link_configuration[0] = DP_LINK_BW_2_7;
621 	else
622 		link_configuration[0] = DP_LINK_BW_1_62;
623 	link_configuration[1] = dig_connector->dp_lane_count;
624 	if (dig_connector->dpcd[0] >= 0x11)
625 		link_configuration[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
626 
627 	/* power up the sink */
628 	dp_set_power(radeon_connector, DP_SET_POWER_D0);
629 	/* disable the training pattern on the sink */
630 	dp_set_training(radeon_connector, DP_TRAINING_PATTERN_DISABLE);
631 	/* set link bw and lanes on the sink */
632 	dp_set_link_bw_lanes(radeon_connector, link_configuration);
633 	/* disable downspread on the sink */
634 	dp_set_downspread(radeon_connector, 0);
635 	if (ASIC_IS_DCE4(rdev)) {
636 		/* start training on the source */
637 		atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_LINK_TRAINING_START);
638 		/* set training pattern 1 on the source */
639 		atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1);
640 	} else {
641 		/* start training on the source */
642 		radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_START,
643 					  dig_connector->dp_clock, enc_id, 0);
644 		/* set training pattern 1 on the source */
645 		radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
646 					  dig_connector->dp_clock, enc_id, 0);
647 	}
648 
649 	/* set initial vs/emph */
650 	memset(train_set, 0, 4);
651 	udelay(400);
652 	/* set training pattern 1 on the sink */
653 	dp_set_training(radeon_connector, DP_TRAINING_PATTERN_1);
654 
655 	dp_update_dpvs_emph(radeon_connector, encoder, train_set);
656 
657 	/* clock recovery loop */
658 	clock_recovery = false;
659 	tries = 0;
660 	voltage = 0xff;
661 	for (;;) {
662 		udelay(100);
663 		if (!atom_dp_get_link_status(radeon_connector, link_status))
664 			break;
665 
666 		if (dp_clock_recovery_ok(link_status, dig_connector->dp_lane_count)) {
667 			clock_recovery = true;
668 			break;
669 		}
670 
671 		for (i = 0; i < dig_connector->dp_lane_count; i++) {
672 			if ((train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
673 				break;
674 		}
675 		if (i == dig_connector->dp_lane_count) {
676 			DRM_ERROR("clock recovery reached max voltage\n");
677 			break;
678 		}
679 
680 		if ((train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
681 			++tries;
682 			if (tries == 5) {
683 				DRM_ERROR("clock recovery tried 5 times\n");
684 				break;
685 			}
686 		} else
687 			tries = 0;
688 
689 		voltage = train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
690 
691 		/* Compute new train_set as requested by sink */
692 		dp_get_adjust_train(link_status, dig_connector->dp_lane_count, train_set);
693 		dp_update_dpvs_emph(radeon_connector, encoder, train_set);
694 	}
695 	if (!clock_recovery)
696 		DRM_ERROR("clock recovery failed\n");
697 	else
698 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
699 			  train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
700 			  (train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
701 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
702 
703 
704 	/* set training pattern 2 on the sink */
705 	dp_set_training(radeon_connector, DP_TRAINING_PATTERN_2);
706 	/* set training pattern 2 on the source */
707 	if (ASIC_IS_DCE4(rdev))
708 		atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2);
709 	else
710 		radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
711 					  dig_connector->dp_clock, enc_id, 1);
712 
713 	/* channel equalization loop */
714 	tries = 0;
715 	channel_eq = false;
716 	for (;;) {
717 		udelay(400);
718 		if (!atom_dp_get_link_status(radeon_connector, link_status))
719 			break;
720 
721 		if (dp_channel_eq_ok(link_status, dig_connector->dp_lane_count)) {
722 			channel_eq = true;
723 			break;
724 		}
725 
726 		/* Try 5 times */
727 		if (tries > 5) {
728 			DRM_ERROR("channel eq failed: 5 tries\n");
729 			break;
730 		}
731 
732 		/* Compute new train_set as requested by sink */
733 		dp_get_adjust_train(link_status, dig_connector->dp_lane_count, train_set);
734 		dp_update_dpvs_emph(radeon_connector, encoder, train_set);
735 
736 		tries++;
737 	}
738 
739 	if (!channel_eq)
740 		DRM_ERROR("channel eq failed\n");
741 	else
742 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
743 			  train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
744 			  (train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
745 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
746 
747 	/* disable the training pattern on the sink */
748 	dp_set_training(radeon_connector, DP_TRAINING_PATTERN_DISABLE);
749 
750 	/* disable the training pattern on the source */
751 	if (ASIC_IS_DCE4(rdev))
752 		atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE);
753 	else
754 		radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_TRAINING_COMPLETE,
755 					  dig_connector->dp_clock, enc_id, 0);
756 }
757 
758 int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
759 			 uint8_t write_byte, uint8_t *read_byte)
760 {
761 	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
762 	struct radeon_i2c_chan *auxch = (struct radeon_i2c_chan *)adapter;
763 	int ret = 0;
764 	uint16_t address = algo_data->address;
765 	uint8_t msg[5];
766 	uint8_t reply[2];
767 	int msg_len, dp_msg_len;
768 	int reply_bytes;
769 
770 	/* Set up the command byte */
771 	if (mode & MODE_I2C_READ)
772 		msg[2] = AUX_I2C_READ << 4;
773 	else
774 		msg[2] = AUX_I2C_WRITE << 4;
775 
776 	if (!(mode & MODE_I2C_STOP))
777 		msg[2] |= AUX_I2C_MOT << 4;
778 
779 	msg[0] = address;
780 	msg[1] = address >> 8;
781 
782 	reply_bytes = 1;
783 
784 	msg_len = 4;
785 	dp_msg_len = 3;
786 	switch (mode) {
787 	case MODE_I2C_WRITE:
788 		msg[4] = write_byte;
789 		msg_len++;
790 		dp_msg_len += 2;
791 		break;
792 	case MODE_I2C_READ:
793 		dp_msg_len += 1;
794 		break;
795 	default:
796 		break;
797 	}
798 
799 	msg[3] = (dp_msg_len) << 4;
800 	ret = radeon_process_aux_ch(auxch, msg, msg_len, reply, reply_bytes, 0);
801 
802 	if (ret) {
803 		if (read_byte)
804 			*read_byte = reply[0];
805 		return reply_bytes;
806 	}
807 	return -EREMOTEIO;
808 }
809 
810