1 /*
2  * Copyright 2022 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: AMD
23  *
24  */
25 
26 /* FILE POLICY AND INTENDED USAGE:
27  * This file manages link detection states and receiver states by using various
28  * link protocols. It also provides helper functions to interpret certain
29  * capabilities or status based on the states it manages or retrieve them
30  * directly from connected receivers.
31  */
32 
33 #include "link_dpms.h"
34 #include "link_detection.h"
35 #include "link_hwss.h"
36 #include "protocols/link_edp_panel_control.h"
37 #include "protocols/link_ddc.h"
38 #include "protocols/link_hpd.h"
39 #include "protocols/link_dpcd.h"
40 #include "protocols/link_dp_capability.h"
41 #include "protocols/link_dp_dpia.h"
42 #include "protocols/link_dp_phy.h"
43 #include "protocols/link_dp_training.h"
44 #include "accessories/link_dp_trace.h"
45 
46 #include "link_enc_cfg.h"
47 #include "dm_helpers.h"
48 #include "clk_mgr.h"
49 
50 #define DC_LOGGER_INIT(logger)
51 
52 #define LINK_INFO(...) \
53 	DC_LOG_HW_HOTPLUG(  \
54 		__VA_ARGS__)
55 /*
56  * Some receivers fail to train on first try and are good
57  * on subsequent tries. 2 retries should be plenty. If we
58  * don't have a successful training then we don't expect to
59  * ever get one.
60  */
61 #define LINK_TRAINING_MAX_VERIFY_RETRY 2
62 
63 static enum ddc_transaction_type get_ddc_transaction_type(enum signal_type sink_signal)
64 {
65 	enum ddc_transaction_type transaction_type = DDC_TRANSACTION_TYPE_NONE;
66 
67 	switch (sink_signal) {
68 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
69 	case SIGNAL_TYPE_DVI_DUAL_LINK:
70 	case SIGNAL_TYPE_HDMI_TYPE_A:
71 	case SIGNAL_TYPE_LVDS:
72 	case SIGNAL_TYPE_RGB:
73 		transaction_type = DDC_TRANSACTION_TYPE_I2C;
74 		break;
75 
76 	case SIGNAL_TYPE_DISPLAY_PORT:
77 	case SIGNAL_TYPE_EDP:
78 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
79 		break;
80 
81 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
82 		/* MST does not use I2COverAux, but there is the
83 		 * SPECIAL use case for "immediate dwnstrm device
84 		 * access" (EPR#370830).
85 		 */
86 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
87 		break;
88 
89 	default:
90 		break;
91 	}
92 
93 	return transaction_type;
94 }
95 
96 static enum signal_type get_basic_signal_type(struct graphics_object_id encoder,
97 					      struct graphics_object_id downstream)
98 {
99 	if (downstream.type == OBJECT_TYPE_CONNECTOR) {
100 		switch (downstream.id) {
101 		case CONNECTOR_ID_SINGLE_LINK_DVII:
102 			switch (encoder.id) {
103 			case ENCODER_ID_INTERNAL_DAC1:
104 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
105 			case ENCODER_ID_INTERNAL_DAC2:
106 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
107 				return SIGNAL_TYPE_RGB;
108 			default:
109 				return SIGNAL_TYPE_DVI_SINGLE_LINK;
110 			}
111 		break;
112 		case CONNECTOR_ID_DUAL_LINK_DVII:
113 		{
114 			switch (encoder.id) {
115 			case ENCODER_ID_INTERNAL_DAC1:
116 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
117 			case ENCODER_ID_INTERNAL_DAC2:
118 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
119 				return SIGNAL_TYPE_RGB;
120 			default:
121 				return SIGNAL_TYPE_DVI_DUAL_LINK;
122 			}
123 		}
124 		break;
125 		case CONNECTOR_ID_SINGLE_LINK_DVID:
126 			return SIGNAL_TYPE_DVI_SINGLE_LINK;
127 		case CONNECTOR_ID_DUAL_LINK_DVID:
128 			return SIGNAL_TYPE_DVI_DUAL_LINK;
129 		case CONNECTOR_ID_VGA:
130 			return SIGNAL_TYPE_RGB;
131 		case CONNECTOR_ID_HDMI_TYPE_A:
132 			return SIGNAL_TYPE_HDMI_TYPE_A;
133 		case CONNECTOR_ID_LVDS:
134 			return SIGNAL_TYPE_LVDS;
135 		case CONNECTOR_ID_DISPLAY_PORT:
136 		case CONNECTOR_ID_USBC:
137 			return SIGNAL_TYPE_DISPLAY_PORT;
138 		case CONNECTOR_ID_EDP:
139 			return SIGNAL_TYPE_EDP;
140 		default:
141 			return SIGNAL_TYPE_NONE;
142 		}
143 	} else if (downstream.type == OBJECT_TYPE_ENCODER) {
144 		switch (downstream.id) {
145 		case ENCODER_ID_EXTERNAL_NUTMEG:
146 		case ENCODER_ID_EXTERNAL_TRAVIS:
147 			return SIGNAL_TYPE_DISPLAY_PORT;
148 		default:
149 			return SIGNAL_TYPE_NONE;
150 		}
151 	}
152 
153 	return SIGNAL_TYPE_NONE;
154 }
155 
156 /*
157  * @brief
158  * Detect output sink type
159  */
160 static enum signal_type link_detect_sink_signal_type(struct dc_link *link,
161 					 enum dc_detect_reason reason)
162 {
163 	enum signal_type result;
164 	struct graphics_object_id enc_id;
165 
166 	if (link->is_dig_mapping_flexible)
167 		enc_id = (struct graphics_object_id){.id = ENCODER_ID_UNKNOWN};
168 	else
169 		enc_id = link->link_enc->id;
170 	result = get_basic_signal_type(enc_id, link->link_id);
171 
172 	/* Use basic signal type for link without physical connector. */
173 	if (link->ep_type != DISPLAY_ENDPOINT_PHY)
174 		return result;
175 
176 	/* Internal digital encoder will detect only dongles
177 	 * that require digital signal
178 	 */
179 
180 	/* Detection mechanism is different
181 	 * for different native connectors.
182 	 * LVDS connector supports only LVDS signal;
183 	 * PCIE is a bus slot, the actual connector needs to be detected first;
184 	 * eDP connector supports only eDP signal;
185 	 * HDMI should check straps for audio
186 	 */
187 
188 	/* PCIE detects the actual connector on add-on board */
189 	if (link->link_id.id == CONNECTOR_ID_PCIE) {
190 		/* ZAZTODO implement PCIE add-on card detection */
191 	}
192 
193 	switch (link->link_id.id) {
194 	case CONNECTOR_ID_HDMI_TYPE_A: {
195 		/* check audio support:
196 		 * if native HDMI is not supported, switch to DVI
197 		 */
198 		struct audio_support *aud_support =
199 					&link->dc->res_pool->audio_support;
200 
201 		if (!aud_support->hdmi_audio_native)
202 			if (link->link_id.id == CONNECTOR_ID_HDMI_TYPE_A)
203 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
204 	}
205 	break;
206 	case CONNECTOR_ID_DISPLAY_PORT:
207 	case CONNECTOR_ID_USBC: {
208 		/* DP HPD short pulse. Passive DP dongle will not
209 		 * have short pulse
210 		 */
211 		if (reason != DETECT_REASON_HPDRX) {
212 			/* Check whether DP signal detected: if not -
213 			 * we assume signal is DVI; it could be corrected
214 			 * to HDMI after dongle detection
215 			 */
216 			if (!dm_helpers_is_dp_sink_present(link))
217 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
218 		}
219 	}
220 	break;
221 	default:
222 	break;
223 	}
224 
225 	return result;
226 }
227 
228 static enum signal_type decide_signal_from_strap_and_dongle_type(enum display_dongle_type dongle_type,
229 								 struct audio_support *audio_support)
230 {
231 	enum signal_type signal = SIGNAL_TYPE_NONE;
232 
233 	switch (dongle_type) {
234 	case DISPLAY_DONGLE_DP_HDMI_DONGLE:
235 		if (audio_support->hdmi_audio_on_dongle)
236 			signal = SIGNAL_TYPE_HDMI_TYPE_A;
237 		else
238 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
239 		break;
240 	case DISPLAY_DONGLE_DP_DVI_DONGLE:
241 		signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
242 		break;
243 	case DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE:
244 		if (audio_support->hdmi_audio_native)
245 			signal =  SIGNAL_TYPE_HDMI_TYPE_A;
246 		else
247 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
248 		break;
249 	default:
250 		signal = SIGNAL_TYPE_NONE;
251 		break;
252 	}
253 
254 	return signal;
255 }
256 
257 static void read_scdc_caps(struct ddc_service *ddc_service,
258 		struct dc_sink *sink)
259 {
260 	uint8_t slave_address = HDMI_SCDC_ADDRESS;
261 	uint8_t offset = HDMI_SCDC_MANUFACTURER_OUI;
262 
263 	link_query_ddc_data(ddc_service, slave_address, &offset,
264 			sizeof(offset), sink->scdc_caps.manufacturer_OUI.byte,
265 			sizeof(sink->scdc_caps.manufacturer_OUI.byte));
266 
267 	offset = HDMI_SCDC_DEVICE_ID;
268 
269 	link_query_ddc_data(ddc_service, slave_address, &offset,
270 			sizeof(offset), &(sink->scdc_caps.device_id.byte),
271 			sizeof(sink->scdc_caps.device_id.byte));
272 }
273 
274 static bool i2c_read(
275 	struct ddc_service *ddc,
276 	uint32_t address,
277 	uint8_t *buffer,
278 	uint32_t len)
279 {
280 	uint8_t offs_data = 0;
281 	struct i2c_payload payloads[2] = {
282 		{
283 		.write = true,
284 		.address = address,
285 		.length = 1,
286 		.data = &offs_data },
287 		{
288 		.write = false,
289 		.address = address,
290 		.length = len,
291 		.data = buffer } };
292 
293 	struct i2c_command command = {
294 		.payloads = payloads,
295 		.number_of_payloads = 2,
296 		.engine = DDC_I2C_COMMAND_ENGINE,
297 		.speed = ddc->ctx->dc->caps.i2c_speed_in_khz };
298 
299 	return dm_helpers_submit_i2c(
300 			ddc->ctx,
301 			ddc->link,
302 			&command);
303 }
304 
305 enum {
306 	DP_SINK_CAP_SIZE =
307 		DP_EDP_CONFIGURATION_CAP - DP_DPCD_REV + 1
308 };
309 
310 static void query_dp_dual_mode_adaptor(
311 	struct ddc_service *ddc,
312 	struct display_sink_capability *sink_cap)
313 {
314 	uint8_t i;
315 	bool is_valid_hdmi_signature;
316 	enum display_dongle_type *dongle = &sink_cap->dongle_type;
317 	uint8_t type2_dongle_buf[DP_ADAPTOR_TYPE2_SIZE];
318 	bool is_type2_dongle = false;
319 	int retry_count = 2;
320 	struct dp_hdmi_dongle_signature_data *dongle_signature;
321 
322 	/* Assume we have no valid DP passive dongle connected */
323 	*dongle = DISPLAY_DONGLE_NONE;
324 	sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_HDMI_SAFE_MAX_TMDS_CLK;
325 
326 	/* Read DP-HDMI dongle I2c (no response interpreted as DP-DVI dongle)*/
327 	if (!i2c_read(
328 		ddc,
329 		DP_HDMI_DONGLE_ADDRESS,
330 		type2_dongle_buf,
331 		sizeof(type2_dongle_buf))) {
332 		/* Passive HDMI dongles can sometimes fail here without retrying*/
333 		while (retry_count > 0) {
334 			if (i2c_read(ddc,
335 				DP_HDMI_DONGLE_ADDRESS,
336 				type2_dongle_buf,
337 				sizeof(type2_dongle_buf)))
338 				break;
339 			retry_count--;
340 		}
341 		if (retry_count == 0) {
342 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
343 			sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK;
344 
345 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf),
346 					"DP-DVI passive dongle %dMhz: ",
347 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
348 			return;
349 		}
350 	}
351 
352 	/* Check if Type 2 dongle.*/
353 	if (type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_ID] == DP_ADAPTOR_TYPE2_ID)
354 		is_type2_dongle = true;
355 
356 	dongle_signature =
357 		(struct dp_hdmi_dongle_signature_data *)type2_dongle_buf;
358 
359 	is_valid_hdmi_signature = true;
360 
361 	/* Check EOT */
362 	if (dongle_signature->eot != DP_HDMI_DONGLE_SIGNATURE_EOT) {
363 		is_valid_hdmi_signature = false;
364 	}
365 
366 	/* Check signature */
367 	for (i = 0; i < sizeof(dongle_signature->id); ++i) {
368 		/* If its not the right signature,
369 		 * skip mismatch in subversion byte.*/
370 		if (dongle_signature->id[i] !=
371 			dp_hdmi_dongle_signature_str[i] && i != 3) {
372 
373 			if (is_type2_dongle) {
374 				is_valid_hdmi_signature = false;
375 				break;
376 			}
377 
378 		}
379 	}
380 
381 	if (is_type2_dongle) {
382 		uint32_t max_tmds_clk =
383 			type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_MAX_TMDS_CLK];
384 
385 		max_tmds_clk = max_tmds_clk * 2 + max_tmds_clk / 2;
386 
387 		if (0 == max_tmds_clk ||
388 				max_tmds_clk < DP_ADAPTOR_TYPE2_MIN_TMDS_CLK ||
389 				max_tmds_clk > DP_ADAPTOR_TYPE2_MAX_TMDS_CLK) {
390 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
391 
392 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
393 					sizeof(type2_dongle_buf),
394 					"DP-DVI passive dongle %dMhz: ",
395 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
396 		} else {
397 			if (is_valid_hdmi_signature == true) {
398 				*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
399 
400 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
401 						sizeof(type2_dongle_buf),
402 						"Type 2 DP-HDMI passive dongle %dMhz: ",
403 						max_tmds_clk);
404 			} else {
405 				*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
406 
407 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
408 						sizeof(type2_dongle_buf),
409 						"Type 2 DP-HDMI passive dongle (no signature) %dMhz: ",
410 						max_tmds_clk);
411 
412 			}
413 
414 			/* Multiply by 1000 to convert to kHz. */
415 			sink_cap->max_hdmi_pixel_clock =
416 				max_tmds_clk * 1000;
417 		}
418 		sink_cap->is_dongle_type_one = false;
419 
420 	} else {
421 		if (is_valid_hdmi_signature == true) {
422 			*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
423 
424 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
425 					sizeof(type2_dongle_buf),
426 					"Type 1 DP-HDMI passive dongle %dMhz: ",
427 					sink_cap->max_hdmi_pixel_clock / 1000);
428 		} else {
429 			*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
430 
431 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
432 					sizeof(type2_dongle_buf),
433 					"Type 1 DP-HDMI passive dongle (no signature) %dMhz: ",
434 					sink_cap->max_hdmi_pixel_clock / 1000);
435 		}
436 		sink_cap->is_dongle_type_one = true;
437 	}
438 
439 	return;
440 }
441 
442 static enum signal_type dp_passive_dongle_detection(struct ddc_service *ddc,
443 						    struct display_sink_capability *sink_cap,
444 						    struct audio_support *audio_support)
445 {
446 	query_dp_dual_mode_adaptor(ddc, sink_cap);
447 
448 	return decide_signal_from_strap_and_dongle_type(sink_cap->dongle_type,
449 							audio_support);
450 }
451 
452 static void link_disconnect_sink(struct dc_link *link)
453 {
454 	if (link->local_sink) {
455 		dc_sink_release(link->local_sink);
456 		link->local_sink = NULL;
457 	}
458 
459 	link->dpcd_sink_count = 0;
460 	//link->dpcd_caps.dpcd_rev.raw = 0;
461 }
462 
463 static void link_disconnect_remap(struct dc_sink *prev_sink, struct dc_link *link)
464 {
465 	dc_sink_release(link->local_sink);
466 	link->local_sink = prev_sink;
467 }
468 
469 static void query_hdcp_capability(enum signal_type signal, struct dc_link *link)
470 {
471 	struct hdcp_protection_message msg22;
472 	struct hdcp_protection_message msg14;
473 
474 	memset(&msg22, 0, sizeof(struct hdcp_protection_message));
475 	memset(&msg14, 0, sizeof(struct hdcp_protection_message));
476 	memset(link->hdcp_caps.rx_caps.raw, 0,
477 		sizeof(link->hdcp_caps.rx_caps.raw));
478 
479 	if ((link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
480 			link->ddc->transaction_type ==
481 			DDC_TRANSACTION_TYPE_I2C_OVER_AUX) ||
482 			link->connector_signal == SIGNAL_TYPE_EDP) {
483 		msg22.data = link->hdcp_caps.rx_caps.raw;
484 		msg22.length = sizeof(link->hdcp_caps.rx_caps.raw);
485 		msg22.msg_id = HDCP_MESSAGE_ID_RX_CAPS;
486 	} else {
487 		msg22.data = &link->hdcp_caps.rx_caps.fields.version;
488 		msg22.length = sizeof(link->hdcp_caps.rx_caps.fields.version);
489 		msg22.msg_id = HDCP_MESSAGE_ID_HDCP2VERSION;
490 	}
491 	msg22.version = HDCP_VERSION_22;
492 	msg22.link = HDCP_LINK_PRIMARY;
493 	msg22.max_retries = 5;
494 	dc_process_hdcp_msg(signal, link, &msg22);
495 
496 	if (signal == SIGNAL_TYPE_DISPLAY_PORT || signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
497 		enum hdcp_message_status status = HDCP_MESSAGE_UNSUPPORTED;
498 
499 		msg14.data = &link->hdcp_caps.bcaps.raw;
500 		msg14.length = sizeof(link->hdcp_caps.bcaps.raw);
501 		msg14.msg_id = HDCP_MESSAGE_ID_READ_BCAPS;
502 		msg14.version = HDCP_VERSION_14;
503 		msg14.link = HDCP_LINK_PRIMARY;
504 		msg14.max_retries = 5;
505 
506 		status = dc_process_hdcp_msg(signal, link, &msg14);
507 	}
508 
509 }
510 static void read_current_link_settings_on_detect(struct dc_link *link)
511 {
512 	union lane_count_set lane_count_set = {0};
513 	uint8_t link_bw_set;
514 	uint8_t link_rate_set;
515 	uint32_t read_dpcd_retry_cnt = 10;
516 	enum dc_status status = DC_ERROR_UNEXPECTED;
517 	int i;
518 	union max_down_spread max_down_spread = {0};
519 
520 	// Read DPCD 00101h to find out the number of lanes currently set
521 	for (i = 0; i < read_dpcd_retry_cnt; i++) {
522 		status = core_link_read_dpcd(link,
523 					     DP_LANE_COUNT_SET,
524 					     &lane_count_set.raw,
525 					     sizeof(lane_count_set));
526 		/* First DPCD read after VDD ON can fail if the particular board
527 		 * does not have HPD pin wired correctly. So if DPCD read fails,
528 		 * which it should never happen, retry a few times. Target worst
529 		 * case scenario of 80 ms.
530 		 */
531 		if (status == DC_OK) {
532 			link->cur_link_settings.lane_count =
533 					lane_count_set.bits.LANE_COUNT_SET;
534 			break;
535 		}
536 
537 		msleep(8);
538 	}
539 
540 	// Read DPCD 00100h to find if standard link rates are set
541 	core_link_read_dpcd(link, DP_LINK_BW_SET,
542 			    &link_bw_set, sizeof(link_bw_set));
543 
544 	if (link_bw_set == 0) {
545 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
546 			/* If standard link rates are not being used,
547 			 * Read DPCD 00115h to find the edp link rate set used
548 			 */
549 			core_link_read_dpcd(link, DP_LINK_RATE_SET,
550 					    &link_rate_set, sizeof(link_rate_set));
551 
552 			// edp_supported_link_rates_count = 0 for DP
553 			if (link_rate_set < link->dpcd_caps.edp_supported_link_rates_count) {
554 				link->cur_link_settings.link_rate =
555 					link->dpcd_caps.edp_supported_link_rates[link_rate_set];
556 				link->cur_link_settings.link_rate_set = link_rate_set;
557 				link->cur_link_settings.use_link_rate_set = true;
558 			}
559 		} else {
560 			// Link Rate not found. Seamless boot may not work.
561 			ASSERT(false);
562 		}
563 	} else {
564 		link->cur_link_settings.link_rate = link_bw_set;
565 		link->cur_link_settings.use_link_rate_set = false;
566 	}
567 	// Read DPCD 00003h to find the max down spread.
568 	core_link_read_dpcd(link, DP_MAX_DOWNSPREAD,
569 			    &max_down_spread.raw, sizeof(max_down_spread));
570 	link->cur_link_settings.link_spread =
571 		max_down_spread.bits.MAX_DOWN_SPREAD ?
572 		LINK_SPREAD_05_DOWNSPREAD_30KHZ : LINK_SPREAD_DISABLED;
573 }
574 
575 static bool detect_dp(struct dc_link *link,
576 		      struct display_sink_capability *sink_caps,
577 		      enum dc_detect_reason reason)
578 {
579 	struct audio_support *audio_support = &link->dc->res_pool->audio_support;
580 
581 	sink_caps->signal = link_detect_sink_signal_type(link, reason);
582 	sink_caps->transaction_type =
583 		get_ddc_transaction_type(sink_caps->signal);
584 
585 	if (sink_caps->transaction_type == DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
586 		sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT;
587 		if (!detect_dp_sink_caps(link))
588 			return false;
589 
590 		if (is_dp_branch_device(link))
591 			/* DP SST branch */
592 			link->type = dc_connection_sst_branch;
593 	} else {
594 		/* DP passive dongles */
595 		sink_caps->signal = dp_passive_dongle_detection(link->ddc,
596 								sink_caps,
597 								audio_support);
598 		link->dpcd_caps.dongle_type = sink_caps->dongle_type;
599 		link->dpcd_caps.is_dongle_type_one = sink_caps->is_dongle_type_one;
600 		link->dpcd_caps.dpcd_rev.raw = 0;
601 	}
602 
603 	return true;
604 }
605 
606 static bool is_same_edid(struct dc_edid *old_edid, struct dc_edid *new_edid)
607 {
608 	if (old_edid->length != new_edid->length)
609 		return false;
610 
611 	if (new_edid->length == 0)
612 		return false;
613 
614 	return (memcmp(old_edid->raw_edid,
615 		       new_edid->raw_edid, new_edid->length) == 0);
616 }
617 
618 static bool wait_for_entering_dp_alt_mode(struct dc_link *link)
619 {
620 
621 	/**
622 	 * something is terribly wrong if time out is > 200ms. (5Hz)
623 	 * 500 microseconds * 400 tries us 200 ms
624 	 **/
625 	unsigned int sleep_time_in_microseconds = 500;
626 	unsigned int tries_allowed = 400;
627 	bool is_in_alt_mode;
628 	unsigned long long enter_timestamp;
629 	unsigned long long finish_timestamp;
630 	unsigned long long time_taken_in_ns;
631 	int tries_taken;
632 
633 	DC_LOGGER_INIT(link->ctx->logger);
634 
635 	/**
636 	 * this function will only exist if we are on dcn21 (is_in_alt_mode is a
637 	 *  function pointer, so checking to see if it is equal to 0 is the same
638 	 *  as checking to see if it is null
639 	 **/
640 	if (!link->link_enc->funcs->is_in_alt_mode)
641 		return true;
642 
643 	is_in_alt_mode = link->link_enc->funcs->is_in_alt_mode(link->link_enc);
644 	DC_LOG_DC("DP Alt mode state on HPD: %d\n", is_in_alt_mode);
645 
646 	if (is_in_alt_mode)
647 		return true;
648 
649 	enter_timestamp = dm_get_timestamp(link->ctx);
650 
651 	for (tries_taken = 0; tries_taken < tries_allowed; tries_taken++) {
652 		udelay(sleep_time_in_microseconds);
653 		/* ask the link if alt mode is enabled, if so return ok */
654 		if (link->link_enc->funcs->is_in_alt_mode(link->link_enc)) {
655 			finish_timestamp = dm_get_timestamp(link->ctx);
656 			time_taken_in_ns =
657 				dm_get_elapse_time_in_ns(link->ctx,
658 							 finish_timestamp,
659 							 enter_timestamp);
660 			DC_LOG_WARNING("Alt mode entered finished after %llu ms\n",
661 				       div_u64(time_taken_in_ns, 1000000));
662 			return true;
663 		}
664 	}
665 	finish_timestamp = dm_get_timestamp(link->ctx);
666 	time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp,
667 						    enter_timestamp);
668 	DC_LOG_WARNING("Alt mode has timed out after %llu ms\n",
669 			div_u64(time_taken_in_ns, 1000000));
670 	return false;
671 }
672 
673 static void apply_dpia_mst_dsc_always_on_wa(struct dc_link *link)
674 {
675 	/* Apply work around for tunneled MST on certain USB4 docks. Always use DSC if dock
676 	 * reports DSC support.
677 	 */
678 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
679 			link->type == dc_connection_mst_branch &&
680 			link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
681 			link->dpcd_caps.branch_hw_revision == DP_BRANCH_HW_REV_20 &&
682 			link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT &&
683 			!link->dc->debug.dpia_debug.bits.disable_mst_dsc_work_around)
684 		link->wa_flags.dpia_mst_dsc_always_on = true;
685 }
686 
687 static void revert_dpia_mst_dsc_always_on_wa(struct dc_link *link)
688 {
689 	/* Disable work around which keeps DSC on for tunneled MST on certain USB4 docks. */
690 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
691 		link->wa_flags.dpia_mst_dsc_always_on = false;
692 }
693 
694 static bool discover_dp_mst_topology(struct dc_link *link, enum dc_detect_reason reason)
695 {
696 	DC_LOGGER_INIT(link->ctx->logger);
697 
698 	LINK_INFO("link=%d, mst branch is now Connected\n",
699 		  link->link_index);
700 
701 	link->type = dc_connection_mst_branch;
702 	apply_dpia_mst_dsc_always_on_wa(link);
703 
704 	dm_helpers_dp_update_branch_info(link->ctx, link);
705 	if (dm_helpers_dp_mst_start_top_mgr(link->ctx,
706 			link, (reason == DETECT_REASON_BOOT || reason == DETECT_REASON_RESUMEFROMS3S4))) {
707 		link_disconnect_sink(link);
708 	} else {
709 		link->type = dc_connection_sst_branch;
710 	}
711 
712 	return link->type == dc_connection_mst_branch;
713 }
714 
715 bool link_reset_cur_dp_mst_topology(struct dc_link *link)
716 {
717 	DC_LOGGER_INIT(link->ctx->logger);
718 
719 	LINK_INFO("link=%d, mst branch is now Disconnected\n",
720 		  link->link_index);
721 
722 	revert_dpia_mst_dsc_always_on_wa(link);
723 	return dm_helpers_dp_mst_stop_top_mgr(link->ctx, link);
724 }
725 
726 static bool should_prepare_phy_clocks_for_link_verification(const struct dc *dc,
727 		enum dc_detect_reason reason)
728 {
729 	int i;
730 	bool can_apply_seamless_boot = false;
731 
732 	for (i = 0; i < dc->current_state->stream_count; i++) {
733 		if (dc->current_state->streams[i]->apply_seamless_boot_optimization) {
734 			can_apply_seamless_boot = true;
735 			break;
736 		}
737 	}
738 
739 	return !can_apply_seamless_boot && reason != DETECT_REASON_BOOT;
740 }
741 
742 static void prepare_phy_clocks_for_destructive_link_verification(const struct dc *dc)
743 {
744 	dc_z10_restore(dc);
745 	clk_mgr_exit_optimized_pwr_state(dc, dc->clk_mgr);
746 }
747 
748 static void restore_phy_clocks_for_destructive_link_verification(const struct dc *dc)
749 {
750 	clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
751 }
752 
753 static void verify_link_capability_destructive(struct dc_link *link,
754 		struct dc_sink *sink,
755 		enum dc_detect_reason reason)
756 {
757 	bool should_prepare_phy_clocks =
758 			should_prepare_phy_clocks_for_link_verification(link->dc, reason);
759 
760 	if (should_prepare_phy_clocks)
761 		prepare_phy_clocks_for_destructive_link_verification(link->dc);
762 
763 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
764 		struct dc_link_settings known_limit_link_setting =
765 				dp_get_max_link_cap(link);
766 		link_set_all_streams_dpms_off_for_link(link);
767 		dp_verify_link_cap_with_retries(
768 				link, &known_limit_link_setting,
769 				LINK_TRAINING_MAX_VERIFY_RETRY);
770 	} else {
771 		ASSERT(0);
772 	}
773 
774 	if (should_prepare_phy_clocks)
775 		restore_phy_clocks_for_destructive_link_verification(link->dc);
776 }
777 
778 static void verify_link_capability_non_destructive(struct dc_link *link)
779 {
780 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
781 		if (dc_is_embedded_signal(link->local_sink->sink_signal) ||
782 				link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
783 			/* TODO - should we check link encoder's max link caps here?
784 			 * How do we know which link encoder to check from?
785 			 */
786 			link->verified_link_cap = link->reported_link_cap;
787 		else
788 			link->verified_link_cap = dp_get_max_link_cap(link);
789 	}
790 }
791 
792 static bool should_verify_link_capability_destructively(struct dc_link *link,
793 		enum dc_detect_reason reason)
794 {
795 	bool destrictive = false;
796 	struct dc_link_settings max_link_cap;
797 	bool is_link_enc_unavailable = link->link_enc &&
798 			link->dc->res_pool->funcs->link_encs_assign &&
799 			!link_enc_cfg_is_link_enc_avail(
800 					link->ctx->dc,
801 					link->link_enc->preferred_engine,
802 					link);
803 
804 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
805 		max_link_cap = dp_get_max_link_cap(link);
806 		destrictive = true;
807 
808 		if (link->dc->debug.skip_detection_link_training ||
809 				dc_is_embedded_signal(link->local_sink->sink_signal) ||
810 				link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA) {
811 			destrictive = false;
812 		} else if (link_dp_get_encoding_format(&max_link_cap) ==
813 				DP_8b_10b_ENCODING) {
814 			if (link->dpcd_caps.is_mst_capable ||
815 					is_link_enc_unavailable) {
816 				destrictive = false;
817 			}
818 		}
819 	}
820 
821 	return destrictive;
822 }
823 
824 static void verify_link_capability(struct dc_link *link, struct dc_sink *sink,
825 		enum dc_detect_reason reason)
826 {
827 	if (should_verify_link_capability_destructively(link, reason))
828 		verify_link_capability_destructive(link, sink, reason);
829 	else
830 		verify_link_capability_non_destructive(link);
831 }
832 
833 /**
834  * detect_link_and_local_sink() - Detect if a sink is attached to a given link
835  *
836  * link->local_sink is created or destroyed as needed.
837  *
838  * This does not create remote sinks.
839  */
840 static bool detect_link_and_local_sink(struct dc_link *link,
841 				  enum dc_detect_reason reason)
842 {
843 	struct dc_sink_init_data sink_init_data = { 0 };
844 	struct display_sink_capability sink_caps = { 0 };
845 	uint32_t i;
846 	bool converter_disable_audio = false;
847 	struct audio_support *aud_support = &link->dc->res_pool->audio_support;
848 	bool same_edid = false;
849 	enum dc_edid_status edid_status;
850 	struct dc_context *dc_ctx = link->ctx;
851 	struct dc *dc = dc_ctx->dc;
852 	struct dc_sink *sink = NULL;
853 	struct dc_sink *prev_sink = NULL;
854 	struct dpcd_caps prev_dpcd_caps;
855 	enum dc_connection_type new_connection_type = dc_connection_none;
856 	const uint32_t post_oui_delay = 30; // 30ms
857 
858 	DC_LOGGER_INIT(link->ctx->logger);
859 
860 	if (dc_is_virtual_signal(link->connector_signal))
861 		return false;
862 
863 	if (((link->connector_signal == SIGNAL_TYPE_LVDS ||
864 		link->connector_signal == SIGNAL_TYPE_EDP) &&
865 		(!link->dc->config.allow_edp_hotplug_detection)) &&
866 		link->local_sink) {
867 		// need to re-write OUI and brightness in resume case
868 		if (link->connector_signal == SIGNAL_TYPE_EDP &&
869 			(link->dpcd_sink_ext_caps.bits.oled == 1)) {
870 			dpcd_set_source_specific_data(link);
871 			msleep(post_oui_delay);
872 			set_default_brightness_aux(link);
873 			//TODO: use cached
874 		}
875 
876 		return true;
877 	}
878 
879 	if (!dc_link_detect_connection_type(link, &new_connection_type)) {
880 		BREAK_TO_DEBUGGER();
881 		return false;
882 	}
883 
884 	prev_sink = link->local_sink;
885 	if (prev_sink) {
886 		dc_sink_retain(prev_sink);
887 		memcpy(&prev_dpcd_caps, &link->dpcd_caps, sizeof(struct dpcd_caps));
888 	}
889 
890 	link_disconnect_sink(link);
891 	if (new_connection_type != dc_connection_none) {
892 		link->type = new_connection_type;
893 		link->link_state_valid = false;
894 
895 		/* From Disconnected-to-Connected. */
896 		switch (link->connector_signal) {
897 		case SIGNAL_TYPE_HDMI_TYPE_A: {
898 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
899 			if (aud_support->hdmi_audio_native)
900 				sink_caps.signal = SIGNAL_TYPE_HDMI_TYPE_A;
901 			else
902 				sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
903 			break;
904 		}
905 
906 		case SIGNAL_TYPE_DVI_SINGLE_LINK: {
907 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
908 			sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
909 			break;
910 		}
911 
912 		case SIGNAL_TYPE_DVI_DUAL_LINK: {
913 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
914 			sink_caps.signal = SIGNAL_TYPE_DVI_DUAL_LINK;
915 			break;
916 		}
917 
918 		case SIGNAL_TYPE_LVDS: {
919 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
920 			sink_caps.signal = SIGNAL_TYPE_LVDS;
921 			break;
922 		}
923 
924 		case SIGNAL_TYPE_EDP: {
925 			detect_edp_sink_caps(link);
926 			read_current_link_settings_on_detect(link);
927 
928 			/* Disable power sequence on MIPI panel + converter
929 			 */
930 			if (dc->config.enable_mipi_converter_optimization &&
931 				dc_ctx->dce_version == DCN_VERSION_3_01 &&
932 				link->dpcd_caps.sink_dev_id == DP_BRANCH_DEVICE_ID_0022B9 &&
933 				memcmp(&link->dpcd_caps.branch_dev_name, DP_SINK_BRANCH_DEV_NAME_7580,
934 					sizeof(link->dpcd_caps.branch_dev_name)) == 0) {
935 				dc->config.edp_no_power_sequencing = true;
936 
937 				if (!link->dpcd_caps.set_power_state_capable_edp)
938 					link->wa_flags.dp_keep_receiver_powered = true;
939 			}
940 
941 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
942 			sink_caps.signal = SIGNAL_TYPE_EDP;
943 			break;
944 		}
945 
946 		case SIGNAL_TYPE_DISPLAY_PORT: {
947 
948 			/* wa HPD high coming too early*/
949 			if (link->ep_type == DISPLAY_ENDPOINT_PHY &&
950 			    link->link_enc->features.flags.bits.DP_IS_USB_C == 1) {
951 
952 				/* if alt mode times out, return false */
953 				if (!wait_for_entering_dp_alt_mode(link))
954 					return false;
955 			}
956 
957 			if (!detect_dp(link, &sink_caps, reason)) {
958 				if (prev_sink)
959 					dc_sink_release(prev_sink);
960 				return false;
961 			}
962 
963 			/* Active SST downstream branch device unplug*/
964 			if (link->type == dc_connection_sst_branch &&
965 			    link->dpcd_caps.sink_count.bits.SINK_COUNT == 0) {
966 				if (prev_sink)
967 					/* Downstream unplug */
968 					dc_sink_release(prev_sink);
969 				return true;
970 			}
971 
972 			/* disable audio for non DP to HDMI active sst converter */
973 			if (link->type == dc_connection_sst_branch &&
974 					is_dp_active_dongle(link) &&
975 					(link->dpcd_caps.dongle_type !=
976 							DISPLAY_DONGLE_DP_HDMI_CONVERTER))
977 				converter_disable_audio = true;
978 			break;
979 		}
980 
981 		default:
982 			DC_ERROR("Invalid connector type! signal:%d\n",
983 				 link->connector_signal);
984 			if (prev_sink)
985 				dc_sink_release(prev_sink);
986 			return false;
987 		} /* switch() */
988 
989 		if (link->dpcd_caps.sink_count.bits.SINK_COUNT)
990 			link->dpcd_sink_count =
991 				link->dpcd_caps.sink_count.bits.SINK_COUNT;
992 		else
993 			link->dpcd_sink_count = 1;
994 
995 		set_ddc_transaction_type(link->ddc,
996 						     sink_caps.transaction_type);
997 
998 		link->aux_mode =
999 			link_is_in_aux_transaction_mode(link->ddc);
1000 
1001 		sink_init_data.link = link;
1002 		sink_init_data.sink_signal = sink_caps.signal;
1003 
1004 		sink = dc_sink_create(&sink_init_data);
1005 		if (!sink) {
1006 			DC_ERROR("Failed to create sink!\n");
1007 			if (prev_sink)
1008 				dc_sink_release(prev_sink);
1009 			return false;
1010 		}
1011 
1012 		sink->link->dongle_max_pix_clk = sink_caps.max_hdmi_pixel_clock;
1013 		sink->converter_disable_audio = converter_disable_audio;
1014 
1015 		/* dc_sink_create returns a new reference */
1016 		link->local_sink = sink;
1017 
1018 		edid_status = dm_helpers_read_local_edid(link->ctx,
1019 							 link, sink);
1020 
1021 		switch (edid_status) {
1022 		case EDID_BAD_CHECKSUM:
1023 			DC_LOG_ERROR("EDID checksum invalid.\n");
1024 			break;
1025 		case EDID_PARTIAL_VALID:
1026 			DC_LOG_ERROR("Partial EDID valid, abandon invalid blocks.\n");
1027 			break;
1028 		case EDID_NO_RESPONSE:
1029 			DC_LOG_ERROR("No EDID read.\n");
1030 			/*
1031 			 * Abort detection for non-DP connectors if we have
1032 			 * no EDID
1033 			 *
1034 			 * DP needs to report as connected if HDP is high
1035 			 * even if we have no EDID in order to go to
1036 			 * fail-safe mode
1037 			 */
1038 			if (dc_is_hdmi_signal(link->connector_signal) ||
1039 			    dc_is_dvi_signal(link->connector_signal)) {
1040 				if (prev_sink)
1041 					dc_sink_release(prev_sink);
1042 
1043 				return false;
1044 			}
1045 
1046 			if (link->type == dc_connection_sst_branch &&
1047 					link->dpcd_caps.dongle_type ==
1048 						DISPLAY_DONGLE_DP_VGA_CONVERTER &&
1049 					reason == DETECT_REASON_HPDRX) {
1050 				/* Abort detection for DP-VGA adapters when EDID
1051 				 * can't be read and detection reason is VGA-side
1052 				 * hotplug
1053 				 */
1054 				if (prev_sink)
1055 					dc_sink_release(prev_sink);
1056 				link_disconnect_sink(link);
1057 
1058 				return true;
1059 			}
1060 
1061 			break;
1062 		default:
1063 			break;
1064 		}
1065 
1066 		// Check if edid is the same
1067 		if ((prev_sink) &&
1068 		    (edid_status == EDID_THE_SAME || edid_status == EDID_OK))
1069 			same_edid = is_same_edid(&prev_sink->dc_edid,
1070 						 &sink->dc_edid);
1071 
1072 		if (sink->edid_caps.panel_patch.skip_scdc_overwrite)
1073 			link->ctx->dc->debug.hdmi20_disable = true;
1074 
1075 		if (dc_is_hdmi_signal(link->connector_signal))
1076 			read_scdc_caps(link->ddc, link->local_sink);
1077 
1078 		if (link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
1079 		    sink_caps.transaction_type ==
1080 		    DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
1081 			/*
1082 			 * TODO debug why certain monitors don't like
1083 			 *  two link trainings
1084 			 */
1085 			query_hdcp_capability(sink->sink_signal, link);
1086 		} else {
1087 			// If edid is the same, then discard new sink and revert back to original sink
1088 			if (same_edid) {
1089 				link_disconnect_remap(prev_sink, link);
1090 				sink = prev_sink;
1091 				prev_sink = NULL;
1092 			}
1093 			query_hdcp_capability(sink->sink_signal, link);
1094 		}
1095 
1096 		/* HDMI-DVI Dongle */
1097 		if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A &&
1098 		    !sink->edid_caps.edid_hdmi)
1099 			sink->sink_signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
1100 
1101 		if (link->local_sink && dc_is_dp_signal(sink_caps.signal))
1102 			dp_trace_init(link);
1103 
1104 		/* Connectivity log: detection */
1105 		for (i = 0; i < sink->dc_edid.length / DC_EDID_BLOCK_SIZE; i++) {
1106 			CONN_DATA_DETECT(link,
1107 					 &sink->dc_edid.raw_edid[i * DC_EDID_BLOCK_SIZE],
1108 					 DC_EDID_BLOCK_SIZE,
1109 					 "%s: [Block %d] ", sink->edid_caps.display_name, i);
1110 		}
1111 
1112 		DC_LOG_DETECTION_EDID_PARSER("%s: "
1113 			"manufacturer_id = %X, "
1114 			"product_id = %X, "
1115 			"serial_number = %X, "
1116 			"manufacture_week = %d, "
1117 			"manufacture_year = %d, "
1118 			"display_name = %s, "
1119 			"speaker_flag = %d, "
1120 			"audio_mode_count = %d\n",
1121 			__func__,
1122 			sink->edid_caps.manufacturer_id,
1123 			sink->edid_caps.product_id,
1124 			sink->edid_caps.serial_number,
1125 			sink->edid_caps.manufacture_week,
1126 			sink->edid_caps.manufacture_year,
1127 			sink->edid_caps.display_name,
1128 			sink->edid_caps.speaker_flags,
1129 			sink->edid_caps.audio_mode_count);
1130 
1131 		for (i = 0; i < sink->edid_caps.audio_mode_count; i++) {
1132 			DC_LOG_DETECTION_EDID_PARSER("%s: mode number = %d, "
1133 				"format_code = %d, "
1134 				"channel_count = %d, "
1135 				"sample_rate = %d, "
1136 				"sample_size = %d\n",
1137 				__func__,
1138 				i,
1139 				sink->edid_caps.audio_modes[i].format_code,
1140 				sink->edid_caps.audio_modes[i].channel_count,
1141 				sink->edid_caps.audio_modes[i].sample_rate,
1142 				sink->edid_caps.audio_modes[i].sample_size);
1143 		}
1144 
1145 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
1146 			// Init dc_panel_config by HW config
1147 			if (dc_ctx->dc->res_pool->funcs->get_panel_config_defaults)
1148 				dc_ctx->dc->res_pool->funcs->get_panel_config_defaults(&link->panel_config);
1149 			// Pickup base DM settings
1150 			dm_helpers_init_panel_settings(dc_ctx, &link->panel_config, sink);
1151 			// Override dc_panel_config if system has specific settings
1152 			dm_helpers_override_panel_settings(dc_ctx, &link->panel_config);
1153 		}
1154 
1155 	} else {
1156 		/* From Connected-to-Disconnected. */
1157 		link->type = dc_connection_none;
1158 		sink_caps.signal = SIGNAL_TYPE_NONE;
1159 		memset(&link->hdcp_caps, 0, sizeof(struct hdcp_caps));
1160 		/* When we unplug a passive DP-HDMI dongle connection, dongle_max_pix_clk
1161 		 *  is not cleared. If we emulate a DP signal on this connection, it thinks
1162 		 *  the dongle is still there and limits the number of modes we can emulate.
1163 		 *  Clear dongle_max_pix_clk on disconnect to fix this
1164 		 */
1165 		link->dongle_max_pix_clk = 0;
1166 
1167 		dc_link_clear_dprx_states(link);
1168 		dp_trace_reset(link);
1169 	}
1170 
1171 	LINK_INFO("link=%d, dc_sink_in=%p is now %s prev_sink=%p edid same=%d\n",
1172 		  link->link_index, sink,
1173 		  (sink_caps.signal ==
1174 		   SIGNAL_TYPE_NONE ? "Disconnected" : "Connected"),
1175 		  prev_sink, same_edid);
1176 
1177 	if (prev_sink)
1178 		dc_sink_release(prev_sink);
1179 
1180 	return true;
1181 }
1182 
1183 /**
1184  * link_detect_connection_type() - Determine if there is a sink connected
1185  *
1186  * @type: Returned connection type
1187  * Does not detect downstream devices, such as MST sinks
1188  * or display connected through active dongles
1189  */
1190 bool link_detect_connection_type(struct dc_link *link, enum dc_connection_type *type)
1191 {
1192 	uint32_t is_hpd_high = 0;
1193 
1194 	if (link->connector_signal == SIGNAL_TYPE_LVDS) {
1195 		*type = dc_connection_single;
1196 		return true;
1197 	}
1198 
1199 	if (link->connector_signal == SIGNAL_TYPE_EDP) {
1200 		/*in case it is not on*/
1201 		if (!link->dc->config.edp_no_power_sequencing)
1202 			link->dc->hwss.edp_power_control(link, true);
1203 		link->dc->hwss.edp_wait_for_hpd_ready(link, true);
1204 	}
1205 
1206 	/* Link may not have physical HPD pin. */
1207 	if (link->ep_type != DISPLAY_ENDPOINT_PHY) {
1208 		if (link->is_hpd_pending || !dpia_query_hpd_status(link))
1209 			*type = dc_connection_none;
1210 		else
1211 			*type = dc_connection_single;
1212 
1213 		return true;
1214 	}
1215 
1216 
1217 	if (!query_hpd_status(link, &is_hpd_high))
1218 		goto hpd_gpio_failure;
1219 
1220 	if (is_hpd_high) {
1221 		*type = dc_connection_single;
1222 		/* TODO: need to do the actual detection */
1223 	} else {
1224 		*type = dc_connection_none;
1225 	}
1226 
1227 	return true;
1228 
1229 hpd_gpio_failure:
1230 	return false;
1231 }
1232 
1233 bool link_detect(struct dc_link *link, enum dc_detect_reason reason)
1234 {
1235 	bool is_local_sink_detect_success;
1236 	bool is_delegated_to_mst_top_mgr = false;
1237 	enum dc_connection_type pre_link_type = link->type;
1238 
1239 	is_local_sink_detect_success = detect_link_and_local_sink(link, reason);
1240 
1241 	if (is_local_sink_detect_success && link->local_sink)
1242 		verify_link_capability(link, link->local_sink, reason);
1243 
1244 	if (is_local_sink_detect_success && link->local_sink &&
1245 			dc_is_dp_signal(link->local_sink->sink_signal) &&
1246 			link->dpcd_caps.is_mst_capable)
1247 		is_delegated_to_mst_top_mgr = discover_dp_mst_topology(link, reason);
1248 
1249 	if (is_local_sink_detect_success &&
1250 			pre_link_type == dc_connection_mst_branch &&
1251 			link->type != dc_connection_mst_branch)
1252 		is_delegated_to_mst_top_mgr = link_reset_cur_dp_mst_topology(link);
1253 
1254 	return is_local_sink_detect_success && !is_delegated_to_mst_top_mgr;
1255 }
1256 
1257 void link_clear_dprx_states(struct dc_link *link)
1258 {
1259 	memset(&link->dprx_states, 0, sizeof(link->dprx_states));
1260 }
1261 
1262 bool link_is_hdcp14(struct dc_link *link, enum signal_type signal)
1263 {
1264 	bool ret = false;
1265 
1266 	switch (signal)	{
1267 	case SIGNAL_TYPE_DISPLAY_PORT:
1268 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1269 		ret = link->hdcp_caps.bcaps.bits.HDCP_CAPABLE;
1270 		break;
1271 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1272 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1273 	case SIGNAL_TYPE_HDMI_TYPE_A:
1274 	/* HDMI doesn't tell us its HDCP(1.4) capability, so assume to always be capable,
1275 	 * we can poll for bksv but some displays have an issue with this. Since its so rare
1276 	 * for a display to not be 1.4 capable, this assumtion is ok
1277 	 */
1278 		ret = true;
1279 		break;
1280 	default:
1281 		break;
1282 	}
1283 	return ret;
1284 }
1285 
1286 bool link_is_hdcp22(struct dc_link *link, enum signal_type signal)
1287 {
1288 	bool ret = false;
1289 
1290 	switch (signal)	{
1291 	case SIGNAL_TYPE_DISPLAY_PORT:
1292 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1293 		ret = (link->hdcp_caps.bcaps.bits.HDCP_CAPABLE &&
1294 				link->hdcp_caps.rx_caps.fields.byte0.hdcp_capable &&
1295 				(link->hdcp_caps.rx_caps.fields.version == 0x2)) ? 1 : 0;
1296 		break;
1297 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1298 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1299 	case SIGNAL_TYPE_HDMI_TYPE_A:
1300 		ret = (link->hdcp_caps.rx_caps.fields.version == 0x4) ? 1:0;
1301 		break;
1302 	default:
1303 		break;
1304 	}
1305 
1306 	return ret;
1307 }
1308 
1309 const struct dc_link_status *link_get_status(const struct dc_link *link)
1310 {
1311 	return &link->link_status;
1312 }
1313 
1314 
1315 static bool link_add_remote_sink_helper(struct dc_link *dc_link, struct dc_sink *sink)
1316 {
1317 	if (dc_link->sink_count >= MAX_SINKS_PER_LINK) {
1318 		BREAK_TO_DEBUGGER();
1319 		return false;
1320 	}
1321 
1322 	dc_sink_retain(sink);
1323 
1324 	dc_link->remote_sinks[dc_link->sink_count] = sink;
1325 	dc_link->sink_count++;
1326 
1327 	return true;
1328 }
1329 
1330 struct dc_sink *link_add_remote_sink(
1331 		struct dc_link *link,
1332 		const uint8_t *edid,
1333 		int len,
1334 		struct dc_sink_init_data *init_data)
1335 {
1336 	struct dc_sink *dc_sink;
1337 	enum dc_edid_status edid_status;
1338 
1339 	if (len > DC_MAX_EDID_BUFFER_SIZE) {
1340 		dm_error("Max EDID buffer size breached!\n");
1341 		return NULL;
1342 	}
1343 
1344 	if (!init_data) {
1345 		BREAK_TO_DEBUGGER();
1346 		return NULL;
1347 	}
1348 
1349 	if (!init_data->link) {
1350 		BREAK_TO_DEBUGGER();
1351 		return NULL;
1352 	}
1353 
1354 	dc_sink = dc_sink_create(init_data);
1355 
1356 	if (!dc_sink)
1357 		return NULL;
1358 
1359 	memmove(dc_sink->dc_edid.raw_edid, edid, len);
1360 	dc_sink->dc_edid.length = len;
1361 
1362 	if (!link_add_remote_sink_helper(
1363 			link,
1364 			dc_sink))
1365 		goto fail_add_sink;
1366 
1367 	edid_status = dm_helpers_parse_edid_caps(
1368 			link,
1369 			&dc_sink->dc_edid,
1370 			&dc_sink->edid_caps);
1371 
1372 	/*
1373 	 * Treat device as no EDID device if EDID
1374 	 * parsing fails
1375 	 */
1376 	if (edid_status != EDID_OK && edid_status != EDID_PARTIAL_VALID) {
1377 		dc_sink->dc_edid.length = 0;
1378 		dm_error("Bad EDID, status%d!\n", edid_status);
1379 	}
1380 
1381 	return dc_sink;
1382 
1383 fail_add_sink:
1384 	dc_sink_release(dc_sink);
1385 	return NULL;
1386 }
1387 
1388 void link_remove_remote_sink(struct dc_link *link, struct dc_sink *sink)
1389 {
1390 	int i;
1391 
1392 	if (!link->sink_count) {
1393 		BREAK_TO_DEBUGGER();
1394 		return;
1395 	}
1396 
1397 	for (i = 0; i < link->sink_count; i++) {
1398 		if (link->remote_sinks[i] == sink) {
1399 			dc_sink_release(sink);
1400 			link->remote_sinks[i] = NULL;
1401 
1402 			/* shrink array to remove empty place */
1403 			while (i < link->sink_count - 1) {
1404 				link->remote_sinks[i] = link->remote_sinks[i+1];
1405 				i++;
1406 			}
1407 			link->remote_sinks[i] = NULL;
1408 			link->sink_count--;
1409 			return;
1410 		}
1411 	}
1412 }
1413