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  *          Jerome Glisse
26  */
27 
28 #include <drm/amdgpu_drm.h>
29 #include "amdgpu.h"
30 
31 #include "atom.h"
32 #include "atom-bits.h"
33 #include "atombios_encoders.h"
34 #include "atombios_dp.h"
35 #include "amdgpu_connectors.h"
36 #include "amdgpu_atombios.h"
37 #include <drm/drm_dp_helper.h>
38 
39 /* move these to drm_dp_helper.c/h */
40 #define DP_LINK_CONFIGURATION_SIZE 9
41 #define DP_DPCD_SIZE DP_RECEIVER_CAP_SIZE
42 
43 static char *voltage_names[] = {
44 	"0.4V", "0.6V", "0.8V", "1.2V"
45 };
46 static char *pre_emph_names[] = {
47 	"0dB", "3.5dB", "6dB", "9.5dB"
48 };
49 
50 /***** amdgpu AUX functions *****/
51 
52 union aux_channel_transaction {
53 	PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
54 	PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
55 };
56 
57 static int amdgpu_atombios_dp_process_aux_ch(struct amdgpu_i2c_chan *chan,
58 				      u8 *send, int send_bytes,
59 				      u8 *recv, int recv_size,
60 				      u8 delay, u8 *ack)
61 {
62 	struct drm_device *dev = chan->dev;
63 	struct amdgpu_device *adev = dev->dev_private;
64 	union aux_channel_transaction args;
65 	int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
66 	unsigned char *base;
67 	int recv_bytes;
68 	int r = 0;
69 
70 	memset(&args, 0, sizeof(args));
71 
72 	mutex_lock(&chan->mutex);
73 
74 	base = (unsigned char *)(adev->mode_info.atom_context->scratch + 1);
75 
76 	amdgpu_atombios_copy_swap(base, send, send_bytes, true);
77 
78 	args.v2.lpAuxRequest = cpu_to_le16((u16)(0 + 4));
79 	args.v2.lpDataOut = cpu_to_le16((u16)(16 + 4));
80 	args.v2.ucDataOutLen = 0;
81 	args.v2.ucChannelID = chan->rec.i2c_id;
82 	args.v2.ucDelay = delay / 10;
83 	args.v2.ucHPD_ID = chan->rec.hpd;
84 
85 	amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
86 
87 	*ack = args.v2.ucReplyStatus;
88 
89 	/* timeout */
90 	if (args.v2.ucReplyStatus == 1) {
91 		r = -ETIMEDOUT;
92 		goto done;
93 	}
94 
95 	/* flags not zero */
96 	if (args.v2.ucReplyStatus == 2) {
97 		DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
98 		r = -EIO;
99 		goto done;
100 	}
101 
102 	/* error */
103 	if (args.v2.ucReplyStatus == 3) {
104 		DRM_DEBUG_KMS("dp_aux_ch error\n");
105 		r = -EIO;
106 		goto done;
107 	}
108 
109 	recv_bytes = args.v1.ucDataOutLen;
110 	if (recv_bytes > recv_size)
111 		recv_bytes = recv_size;
112 
113 	if (recv && recv_size)
114 		amdgpu_atombios_copy_swap(recv, base + 16, recv_bytes, false);
115 
116 	r = recv_bytes;
117 done:
118 	mutex_unlock(&chan->mutex);
119 
120 	return r;
121 }
122 
123 #define BARE_ADDRESS_SIZE 3
124 #define HEADER_SIZE (BARE_ADDRESS_SIZE + 1)
125 
126 static ssize_t
127 amdgpu_atombios_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
128 {
129 	struct amdgpu_i2c_chan *chan =
130 		container_of(aux, struct amdgpu_i2c_chan, aux);
131 	int ret;
132 	u8 tx_buf[20];
133 	size_t tx_size;
134 	u8 ack, delay = 0;
135 
136 	if (WARN_ON(msg->size > 16))
137 		return -E2BIG;
138 
139 	tx_buf[0] = msg->address & 0xff;
140 	tx_buf[1] = msg->address >> 8;
141 	tx_buf[2] = (msg->request << 4) |
142 		((msg->address >> 16) & 0xf);
143 	tx_buf[3] = msg->size ? (msg->size - 1) : 0;
144 
145 	switch (msg->request & ~DP_AUX_I2C_MOT) {
146 	case DP_AUX_NATIVE_WRITE:
147 	case DP_AUX_I2C_WRITE:
148 		/* tx_size needs to be 4 even for bare address packets since the atom
149 		 * table needs the info in tx_buf[3].
150 		 */
151 		tx_size = HEADER_SIZE + msg->size;
152 		if (msg->size == 0)
153 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
154 		else
155 			tx_buf[3] |= tx_size << 4;
156 		memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
157 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
158 						 tx_buf, tx_size, NULL, 0, delay, &ack);
159 		if (ret >= 0)
160 			/* Return payload size. */
161 			ret = msg->size;
162 		break;
163 	case DP_AUX_NATIVE_READ:
164 	case DP_AUX_I2C_READ:
165 		/* tx_size needs to be 4 even for bare address packets since the atom
166 		 * table needs the info in tx_buf[3].
167 		 */
168 		tx_size = HEADER_SIZE;
169 		if (msg->size == 0)
170 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
171 		else
172 			tx_buf[3] |= tx_size << 4;
173 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
174 						 tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
175 		break;
176 	default:
177 		ret = -EINVAL;
178 		break;
179 	}
180 
181 	if (ret >= 0)
182 		msg->reply = ack >> 4;
183 
184 	return ret;
185 }
186 
187 void amdgpu_atombios_dp_aux_init(struct amdgpu_connector *amdgpu_connector)
188 {
189 	int ret;
190 
191 	amdgpu_connector->ddc_bus->rec.hpd = amdgpu_connector->hpd.hpd;
192 	amdgpu_connector->ddc_bus->aux.dev = amdgpu_connector->base.kdev;
193 	amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;
194 	ret = drm_dp_aux_register(&amdgpu_connector->ddc_bus->aux);
195 	if (!ret)
196 		amdgpu_connector->ddc_bus->has_aux = true;
197 
198 	WARN(ret, "drm_dp_aux_register_i2c_bus() failed with error %d\n", ret);
199 }
200 
201 /***** general DP utility functions *****/
202 
203 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_LEVEL_3
204 #define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPH_LEVEL_3
205 
206 static void amdgpu_atombios_dp_get_adjust_train(const u8 link_status[DP_LINK_STATUS_SIZE],
207 						int lane_count,
208 						u8 train_set[4])
209 {
210 	u8 v = 0;
211 	u8 p = 0;
212 	int lane;
213 
214 	for (lane = 0; lane < lane_count; lane++) {
215 		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
216 		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
217 
218 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
219 			  lane,
220 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
221 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
222 
223 		if (this_v > v)
224 			v = this_v;
225 		if (this_p > p)
226 			p = this_p;
227 	}
228 
229 	if (v >= DP_VOLTAGE_MAX)
230 		v |= DP_TRAIN_MAX_SWING_REACHED;
231 
232 	if (p >= DP_PRE_EMPHASIS_MAX)
233 		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
234 
235 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
236 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
237 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
238 
239 	for (lane = 0; lane < 4; lane++)
240 		train_set[lane] = v | p;
241 }
242 
243 /* convert bits per color to bits per pixel */
244 /* get bpc from the EDID */
245 static unsigned amdgpu_atombios_dp_convert_bpc_to_bpp(int bpc)
246 {
247 	if (bpc == 0)
248 		return 24;
249 	else
250 		return bpc * 3;
251 }
252 
253 /***** amdgpu specific DP functions *****/
254 
255 static int amdgpu_atombios_dp_get_dp_link_config(struct drm_connector *connector,
256 						 const u8 dpcd[DP_DPCD_SIZE],
257 						 unsigned pix_clock,
258 						 unsigned *dp_lanes, unsigned *dp_rate)
259 {
260 	unsigned bpp =
261 		amdgpu_atombios_dp_convert_bpc_to_bpp(amdgpu_connector_get_monitor_bpc(connector));
262 	static const unsigned link_rates[3] = { 162000, 270000, 540000 };
263 	unsigned max_link_rate = drm_dp_max_link_rate(dpcd);
264 	unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
265 	unsigned lane_num, i, max_pix_clock;
266 
267 	if (amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector) ==
268 	    ENCODER_OBJECT_ID_NUTMEG) {
269 		for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
270 			max_pix_clock = (lane_num * 270000 * 8) / bpp;
271 			if (max_pix_clock >= pix_clock) {
272 				*dp_lanes = lane_num;
273 				*dp_rate = 270000;
274 				return 0;
275 			}
276 		}
277 	} else {
278 		for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
279 			for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
280 				max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
281 				if (max_pix_clock >= pix_clock) {
282 					*dp_lanes = lane_num;
283 					*dp_rate = link_rates[i];
284 					return 0;
285 				}
286 			}
287 		}
288 	}
289 
290 	return -EINVAL;
291 }
292 
293 static u8 amdgpu_atombios_dp_encoder_service(struct amdgpu_device *adev,
294 				      int action, int dp_clock,
295 				      u8 ucconfig, u8 lane_num)
296 {
297 	DP_ENCODER_SERVICE_PARAMETERS args;
298 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
299 
300 	memset(&args, 0, sizeof(args));
301 	args.ucLinkClock = dp_clock / 10;
302 	args.ucConfig = ucconfig;
303 	args.ucAction = action;
304 	args.ucLaneNum = lane_num;
305 	args.ucStatus = 0;
306 
307 	amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
308 	return args.ucStatus;
309 }
310 
311 u8 amdgpu_atombios_dp_get_sinktype(struct amdgpu_connector *amdgpu_connector)
312 {
313 	struct drm_device *dev = amdgpu_connector->base.dev;
314 	struct amdgpu_device *adev = dev->dev_private;
315 
316 	return amdgpu_atombios_dp_encoder_service(adev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
317 					   amdgpu_connector->ddc_bus->rec.i2c_id, 0);
318 }
319 
320 static void amdgpu_atombios_dp_probe_oui(struct amdgpu_connector *amdgpu_connector)
321 {
322 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
323 	u8 buf[3];
324 
325 	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
326 		return;
327 
328 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3)
329 		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
330 			      buf[0], buf[1], buf[2]);
331 
332 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3)
333 		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
334 			      buf[0], buf[1], buf[2]);
335 }
336 
337 int amdgpu_atombios_dp_get_dpcd(struct amdgpu_connector *amdgpu_connector)
338 {
339 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
340 	u8 msg[DP_DPCD_SIZE];
341 	int ret;
342 
343 	ret = drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_DPCD_REV,
344 			       msg, DP_DPCD_SIZE);
345 	if (ret == DP_DPCD_SIZE) {
346 		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
347 
348 		DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
349 			      dig_connector->dpcd);
350 
351 		amdgpu_atombios_dp_probe_oui(amdgpu_connector);
352 
353 		return 0;
354 	}
355 
356 	dig_connector->dpcd[0] = 0;
357 	return -EINVAL;
358 }
359 
360 int amdgpu_atombios_dp_get_panel_mode(struct drm_encoder *encoder,
361 			       struct drm_connector *connector)
362 {
363 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
364 	struct amdgpu_connector_atom_dig *dig_connector;
365 	int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
366 	u16 dp_bridge = amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector);
367 	u8 tmp;
368 
369 	if (!amdgpu_connector->con_priv)
370 		return panel_mode;
371 
372 	dig_connector = amdgpu_connector->con_priv;
373 
374 	if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
375 		/* DP bridge chips */
376 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
377 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
378 			if (tmp & 1)
379 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
380 			else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
381 				 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
382 				panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
383 			else
384 				panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
385 		}
386 	} else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
387 		/* eDP */
388 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
389 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
390 			if (tmp & 1)
391 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
392 		}
393 	}
394 
395 	return panel_mode;
396 }
397 
398 void amdgpu_atombios_dp_set_link_config(struct drm_connector *connector,
399 				 const struct drm_display_mode *mode)
400 {
401 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
402 	struct amdgpu_connector_atom_dig *dig_connector;
403 	int ret;
404 
405 	if (!amdgpu_connector->con_priv)
406 		return;
407 	dig_connector = amdgpu_connector->con_priv;
408 
409 	if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
410 	    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
411 		ret = amdgpu_atombios_dp_get_dp_link_config(connector, dig_connector->dpcd,
412 							    mode->clock,
413 							    &dig_connector->dp_lane_count,
414 							    &dig_connector->dp_clock);
415 		if (ret) {
416 			dig_connector->dp_clock = 0;
417 			dig_connector->dp_lane_count = 0;
418 		}
419 	}
420 }
421 
422 int amdgpu_atombios_dp_mode_valid_helper(struct drm_connector *connector,
423 				  struct drm_display_mode *mode)
424 {
425 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
426 	struct amdgpu_connector_atom_dig *dig_connector;
427 	unsigned dp_lanes, dp_clock;
428 	int ret;
429 
430 	if (!amdgpu_connector->con_priv)
431 		return MODE_CLOCK_HIGH;
432 	dig_connector = amdgpu_connector->con_priv;
433 
434 	ret = amdgpu_atombios_dp_get_dp_link_config(connector, dig_connector->dpcd,
435 						    mode->clock, &dp_lanes, &dp_clock);
436 	if (ret)
437 		return MODE_CLOCK_HIGH;
438 
439 	if ((dp_clock == 540000) &&
440 	    (!amdgpu_connector_is_dp12_capable(connector)))
441 		return MODE_CLOCK_HIGH;
442 
443 	return MODE_OK;
444 }
445 
446 bool amdgpu_atombios_dp_needs_link_train(struct amdgpu_connector *amdgpu_connector)
447 {
448 	u8 link_status[DP_LINK_STATUS_SIZE];
449 	struct amdgpu_connector_atom_dig *dig = amdgpu_connector->con_priv;
450 
451 	if (drm_dp_dpcd_read_link_status(&amdgpu_connector->ddc_bus->aux, link_status)
452 	    <= 0)
453 		return false;
454 	if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
455 		return false;
456 	return true;
457 }
458 
459 void amdgpu_atombios_dp_set_rx_power_state(struct drm_connector *connector,
460 				    u8 power_state)
461 {
462 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
463 	struct amdgpu_connector_atom_dig *dig_connector;
464 
465 	if (!amdgpu_connector->con_priv)
466 		return;
467 
468 	dig_connector = amdgpu_connector->con_priv;
469 
470 	/* power up/down the sink */
471 	if (dig_connector->dpcd[0] >= 0x11) {
472 		drm_dp_dpcd_writeb(&amdgpu_connector->ddc_bus->aux,
473 				   DP_SET_POWER, power_state);
474 		usleep_range(1000, 2000);
475 	}
476 }
477 
478 struct amdgpu_atombios_dp_link_train_info {
479 	struct amdgpu_device *adev;
480 	struct drm_encoder *encoder;
481 	struct drm_connector *connector;
482 	int dp_clock;
483 	int dp_lane_count;
484 	bool tp3_supported;
485 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
486 	u8 train_set[4];
487 	u8 link_status[DP_LINK_STATUS_SIZE];
488 	u8 tries;
489 	struct drm_dp_aux *aux;
490 };
491 
492 static void
493 amdgpu_atombios_dp_update_vs_emph(struct amdgpu_atombios_dp_link_train_info *dp_info)
494 {
495 	/* set the initial vs/emph on the source */
496 	amdgpu_atombios_encoder_setup_dig_transmitter(dp_info->encoder,
497 					       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
498 					       0, dp_info->train_set[0]); /* sets all lanes at once */
499 
500 	/* set the vs/emph on the sink */
501 	drm_dp_dpcd_write(dp_info->aux, DP_TRAINING_LANE0_SET,
502 			  dp_info->train_set, dp_info->dp_lane_count);
503 }
504 
505 static void
506 amdgpu_atombios_dp_set_tp(struct amdgpu_atombios_dp_link_train_info *dp_info, int tp)
507 {
508 	int rtp = 0;
509 
510 	/* set training pattern on the source */
511 	switch (tp) {
512 	case DP_TRAINING_PATTERN_1:
513 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
514 		break;
515 	case DP_TRAINING_PATTERN_2:
516 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
517 		break;
518 	case DP_TRAINING_PATTERN_3:
519 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
520 			break;
521 	}
522 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder, rtp, 0);
523 
524 	/* enable training pattern on the sink */
525 	drm_dp_dpcd_writeb(dp_info->aux, DP_TRAINING_PATTERN_SET, tp);
526 }
527 
528 static int
529 amdgpu_atombios_dp_link_train_init(struct amdgpu_atombios_dp_link_train_info *dp_info)
530 {
531 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(dp_info->encoder);
532 	struct amdgpu_encoder_atom_dig *dig = amdgpu_encoder->enc_priv;
533 	u8 tmp;
534 
535 	/* power up the sink */
536 	amdgpu_atombios_dp_set_rx_power_state(dp_info->connector, DP_SET_POWER_D0);
537 
538 	/* possibly enable downspread on the sink */
539 	if (dp_info->dpcd[3] & 0x1)
540 		drm_dp_dpcd_writeb(dp_info->aux,
541 				   DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
542 	else
543 		drm_dp_dpcd_writeb(dp_info->aux,
544 				   DP_DOWNSPREAD_CTRL, 0);
545 
546 	if (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)
547 		drm_dp_dpcd_writeb(dp_info->aux, DP_EDP_CONFIGURATION_SET, 1);
548 
549 	/* set the lane count on the sink */
550 	tmp = dp_info->dp_lane_count;
551 	if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
552 		tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
553 	drm_dp_dpcd_writeb(dp_info->aux, DP_LANE_COUNT_SET, tmp);
554 
555 	/* set the link rate on the sink */
556 	tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
557 	drm_dp_dpcd_writeb(dp_info->aux, DP_LINK_BW_SET, tmp);
558 
559 	/* start training on the source */
560 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
561 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
562 
563 	/* disable the training pattern on the sink */
564 	drm_dp_dpcd_writeb(dp_info->aux,
565 			   DP_TRAINING_PATTERN_SET,
566 			   DP_TRAINING_PATTERN_DISABLE);
567 
568 	return 0;
569 }
570 
571 static int
572 amdgpu_atombios_dp_link_train_finish(struct amdgpu_atombios_dp_link_train_info *dp_info)
573 {
574 	udelay(400);
575 
576 	/* disable the training pattern on the sink */
577 	drm_dp_dpcd_writeb(dp_info->aux,
578 			   DP_TRAINING_PATTERN_SET,
579 			   DP_TRAINING_PATTERN_DISABLE);
580 
581 	/* disable the training pattern on the source */
582 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
583 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
584 
585 	return 0;
586 }
587 
588 static int
589 amdgpu_atombios_dp_link_train_cr(struct amdgpu_atombios_dp_link_train_info *dp_info)
590 {
591 	bool clock_recovery;
592 	u8 voltage;
593 	int i;
594 
595 	amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
596 	memset(dp_info->train_set, 0, 4);
597 	amdgpu_atombios_dp_update_vs_emph(dp_info);
598 
599 	udelay(400);
600 
601 	/* clock recovery loop */
602 	clock_recovery = false;
603 	dp_info->tries = 0;
604 	voltage = 0xff;
605 	while (1) {
606 		drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);
607 
608 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
609 						 dp_info->link_status) <= 0) {
610 			DRM_ERROR("displayport link status failed\n");
611 			break;
612 		}
613 
614 		if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
615 			clock_recovery = true;
616 			break;
617 		}
618 
619 		for (i = 0; i < dp_info->dp_lane_count; i++) {
620 			if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
621 				break;
622 		}
623 		if (i == dp_info->dp_lane_count) {
624 			DRM_ERROR("clock recovery reached max voltage\n");
625 			break;
626 		}
627 
628 		if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
629 			++dp_info->tries;
630 			if (dp_info->tries == 5) {
631 				DRM_ERROR("clock recovery tried 5 times\n");
632 				break;
633 			}
634 		} else
635 			dp_info->tries = 0;
636 
637 		voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
638 
639 		/* Compute new train_set as requested by sink */
640 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
641 					     dp_info->train_set);
642 
643 		amdgpu_atombios_dp_update_vs_emph(dp_info);
644 	}
645 	if (!clock_recovery) {
646 		DRM_ERROR("clock recovery failed\n");
647 		return -1;
648 	} else {
649 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
650 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
651 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
652 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
653 		return 0;
654 	}
655 }
656 
657 static int
658 amdgpu_atombios_dp_link_train_ce(struct amdgpu_atombios_dp_link_train_info *dp_info)
659 {
660 	bool channel_eq;
661 
662 	if (dp_info->tp3_supported)
663 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
664 	else
665 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
666 
667 	/* channel equalization loop */
668 	dp_info->tries = 0;
669 	channel_eq = false;
670 	while (1) {
671 		drm_dp_link_train_channel_eq_delay(dp_info->dpcd);
672 
673 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
674 						 dp_info->link_status) <= 0) {
675 			DRM_ERROR("displayport link status failed\n");
676 			break;
677 		}
678 
679 		if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
680 			channel_eq = true;
681 			break;
682 		}
683 
684 		/* Try 5 times */
685 		if (dp_info->tries > 5) {
686 			DRM_ERROR("channel eq failed: 5 tries\n");
687 			break;
688 		}
689 
690 		/* Compute new train_set as requested by sink */
691 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
692 					     dp_info->train_set);
693 
694 		amdgpu_atombios_dp_update_vs_emph(dp_info);
695 		dp_info->tries++;
696 	}
697 
698 	if (!channel_eq) {
699 		DRM_ERROR("channel eq failed\n");
700 		return -1;
701 	} else {
702 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
703 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
704 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
705 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
706 		return 0;
707 	}
708 }
709 
710 void amdgpu_atombios_dp_link_train(struct drm_encoder *encoder,
711 			    struct drm_connector *connector)
712 {
713 	struct drm_device *dev = encoder->dev;
714 	struct amdgpu_device *adev = dev->dev_private;
715 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(encoder);
716 	struct amdgpu_encoder_atom_dig *dig;
717 	struct amdgpu_connector *amdgpu_connector;
718 	struct amdgpu_connector_atom_dig *dig_connector;
719 	struct amdgpu_atombios_dp_link_train_info dp_info;
720 	u8 tmp;
721 
722 	if (!amdgpu_encoder->enc_priv)
723 		return;
724 	dig = amdgpu_encoder->enc_priv;
725 
726 	amdgpu_connector = to_amdgpu_connector(connector);
727 	if (!amdgpu_connector->con_priv)
728 		return;
729 	dig_connector = amdgpu_connector->con_priv;
730 
731 	if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
732 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
733 		return;
734 
735 	if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp)
736 	    == 1) {
737 		if (tmp & DP_TPS3_SUPPORTED)
738 			dp_info.tp3_supported = true;
739 		else
740 			dp_info.tp3_supported = false;
741 	} else {
742 		dp_info.tp3_supported = false;
743 	}
744 
745 	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
746 	dp_info.adev = adev;
747 	dp_info.encoder = encoder;
748 	dp_info.connector = connector;
749 	dp_info.dp_lane_count = dig_connector->dp_lane_count;
750 	dp_info.dp_clock = dig_connector->dp_clock;
751 	dp_info.aux = &amdgpu_connector->ddc_bus->aux;
752 
753 	if (amdgpu_atombios_dp_link_train_init(&dp_info))
754 		goto done;
755 	if (amdgpu_atombios_dp_link_train_cr(&dp_info))
756 		goto done;
757 	if (amdgpu_atombios_dp_link_train_ce(&dp_info))
758 		goto done;
759 done:
760 	if (amdgpu_atombios_dp_link_train_finish(&dp_info))
761 		return;
762 }
763