1 /*
2  * Copyright 2014 Red Hat 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: Ben Skeggs
23  */
24 #include "dp.h"
25 #include "conn.h"
26 #include "head.h"
27 #include "ior.h"
28 
29 #include <subdev/bios.h>
30 #include <subdev/bios/init.h>
31 #include <subdev/gpio.h>
32 #include <subdev/i2c.h>
33 
34 #include <nvif/event.h>
35 
36 struct lt_state {
37 	struct nvkm_dp *dp;
38 	u8  stat[6];
39 	u8  conf[4];
40 	bool pc2;
41 	u8  pc2stat;
42 	u8  pc2conf[2];
43 };
44 
45 static int
46 nvkm_dp_train_sense(struct lt_state *lt, bool pc, u32 delay)
47 {
48 	struct nvkm_dp *dp = lt->dp;
49 	int ret;
50 
51 	if (dp->dpcd[DPCD_RC0E_AUX_RD_INTERVAL])
52 		mdelay(dp->dpcd[DPCD_RC0E_AUX_RD_INTERVAL] * 4);
53 	else
54 		udelay(delay);
55 
56 	ret = nvkm_rdaux(dp->aux, DPCD_LS02, lt->stat, 6);
57 	if (ret)
58 		return ret;
59 
60 	if (pc) {
61 		ret = nvkm_rdaux(dp->aux, DPCD_LS0C, &lt->pc2stat, 1);
62 		if (ret)
63 			lt->pc2stat = 0x00;
64 		OUTP_TRACE(&dp->outp, "status %6ph pc2 %02x",
65 			   lt->stat, lt->pc2stat);
66 	} else {
67 		OUTP_TRACE(&dp->outp, "status %6ph", lt->stat);
68 	}
69 
70 	return 0;
71 }
72 
73 static int
74 nvkm_dp_train_drive(struct lt_state *lt, bool pc)
75 {
76 	struct nvkm_dp *dp = lt->dp;
77 	struct nvkm_ior *ior = dp->outp.ior;
78 	struct nvkm_bios *bios = ior->disp->engine.subdev.device->bios;
79 	struct nvbios_dpout info;
80 	struct nvbios_dpcfg ocfg;
81 	u8  ver, hdr, cnt, len;
82 	u32 data;
83 	int ret, i;
84 
85 	for (i = 0; i < ior->dp.nr; i++) {
86 		u8 lane = (lt->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
87 		u8 lpc2 = (lt->pc2stat >> (i * 2)) & 0x3;
88 		u8 lpre = (lane & 0x0c) >> 2;
89 		u8 lvsw = (lane & 0x03) >> 0;
90 		u8 hivs = 3 - lpre;
91 		u8 hipe = 3;
92 		u8 hipc = 3;
93 
94 		if (lpc2 >= hipc)
95 			lpc2 = hipc | DPCD_LC0F_LANE0_MAX_POST_CURSOR2_REACHED;
96 		if (lpre >= hipe) {
97 			lpre = hipe | DPCD_LC03_MAX_SWING_REACHED; /* yes. */
98 			lvsw = hivs = 3 - (lpre & 3);
99 		} else
100 		if (lvsw >= hivs) {
101 			lvsw = hivs | DPCD_LC03_MAX_SWING_REACHED;
102 		}
103 
104 		lt->conf[i] = (lpre << 3) | lvsw;
105 		lt->pc2conf[i >> 1] |= lpc2 << ((i & 1) * 4);
106 
107 		OUTP_TRACE(&dp->outp, "config lane %d %02x %02x",
108 			   i, lt->conf[i], lpc2);
109 
110 		data = nvbios_dpout_match(bios, dp->outp.info.hasht,
111 						dp->outp.info.hashm,
112 					  &ver, &hdr, &cnt, &len, &info);
113 		if (!data)
114 			continue;
115 
116 		data = nvbios_dpcfg_match(bios, data, lpc2 & 3, lvsw & 3,
117 					  lpre & 3, &ver, &hdr, &cnt, &len,
118 					  &ocfg);
119 		if (!data)
120 			continue;
121 
122 		ior->func->dp.drive(ior, i, ocfg.pc, ocfg.dc,
123 					    ocfg.pe, ocfg.tx_pu);
124 	}
125 
126 	ret = nvkm_wraux(dp->aux, DPCD_LC03(0), lt->conf, 4);
127 	if (ret)
128 		return ret;
129 
130 	if (pc) {
131 		ret = nvkm_wraux(dp->aux, DPCD_LC0F, lt->pc2conf, 2);
132 		if (ret)
133 			return ret;
134 	}
135 
136 	return 0;
137 }
138 
139 static void
140 nvkm_dp_train_pattern(struct lt_state *lt, u8 pattern)
141 {
142 	struct nvkm_dp *dp = lt->dp;
143 	u8 sink_tp;
144 
145 	OUTP_TRACE(&dp->outp, "training pattern %d", pattern);
146 	dp->outp.ior->func->dp.pattern(dp->outp.ior, pattern);
147 
148 	nvkm_rdaux(dp->aux, DPCD_LC02, &sink_tp, 1);
149 	sink_tp &= ~DPCD_LC02_TRAINING_PATTERN_SET;
150 	sink_tp |= pattern;
151 	nvkm_wraux(dp->aux, DPCD_LC02, &sink_tp, 1);
152 }
153 
154 static int
155 nvkm_dp_train_eq(struct lt_state *lt)
156 {
157 	bool eq_done = false, cr_done = true;
158 	int tries = 0, i;
159 
160 	if (lt->dp->dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED)
161 		nvkm_dp_train_pattern(lt, 3);
162 	else
163 		nvkm_dp_train_pattern(lt, 2);
164 
165 	do {
166 		if ((tries &&
167 		    nvkm_dp_train_drive(lt, lt->pc2)) ||
168 		    nvkm_dp_train_sense(lt, lt->pc2, 400))
169 			break;
170 
171 		eq_done = !!(lt->stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE);
172 		for (i = 0; i < lt->dp->outp.ior->dp.nr && eq_done; i++) {
173 			u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
174 			if (!(lane & DPCD_LS02_LANE0_CR_DONE))
175 				cr_done = false;
176 			if (!(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
177 			    !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED))
178 				eq_done = false;
179 		}
180 	} while (!eq_done && cr_done && ++tries <= 5);
181 
182 	return eq_done ? 0 : -1;
183 }
184 
185 static int
186 nvkm_dp_train_cr(struct lt_state *lt)
187 {
188 	bool cr_done = false, abort = false;
189 	int voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
190 	int tries = 0, i;
191 
192 	nvkm_dp_train_pattern(lt, 1);
193 
194 	do {
195 		if (nvkm_dp_train_drive(lt, false) ||
196 		    nvkm_dp_train_sense(lt, false, 100))
197 			break;
198 
199 		cr_done = true;
200 		for (i = 0; i < lt->dp->outp.ior->dp.nr; i++) {
201 			u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
202 			if (!(lane & DPCD_LS02_LANE0_CR_DONE)) {
203 				cr_done = false;
204 				if (lt->conf[i] & DPCD_LC03_MAX_SWING_REACHED)
205 					abort = true;
206 				break;
207 			}
208 		}
209 
210 		if ((lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET) != voltage) {
211 			voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
212 			tries = 0;
213 		}
214 	} while (!cr_done && !abort && ++tries < 5);
215 
216 	return cr_done ? 0 : -1;
217 }
218 
219 static int
220 nvkm_dp_train_links(struct nvkm_dp *dp)
221 {
222 	struct nvkm_ior *ior = dp->outp.ior;
223 	struct nvkm_disp *disp = dp->outp.disp;
224 	struct nvkm_subdev *subdev = &disp->engine.subdev;
225 	struct nvkm_bios *bios = subdev->device->bios;
226 	struct lt_state lt = {
227 		.dp = dp,
228 	};
229 	u32 lnkcmp;
230 	u8 sink[2];
231 	int ret;
232 
233 	OUTP_DBG(&dp->outp, "training %d x %d MB/s",
234 		 ior->dp.nr, ior->dp.bw * 27);
235 
236 	/* Intersect misc. capabilities of the OR and sink. */
237 	if (disp->engine.subdev.device->chipset < 0xd0)
238 		dp->dpcd[DPCD_RC02] &= ~DPCD_RC02_TPS3_SUPPORTED;
239 	lt.pc2 = dp->dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED;
240 
241 	/* Set desired link configuration on the source. */
242 	if ((lnkcmp = lt.dp->info.lnkcmp)) {
243 		if (dp->version < 0x30) {
244 			while ((ior->dp.bw * 2700) < nvbios_rd16(bios, lnkcmp))
245 				lnkcmp += 4;
246 			lnkcmp = nvbios_rd16(bios, lnkcmp + 2);
247 		} else {
248 			while (ior->dp.bw < nvbios_rd08(bios, lnkcmp))
249 				lnkcmp += 3;
250 			lnkcmp = nvbios_rd16(bios, lnkcmp + 1);
251 		}
252 
253 		nvbios_init(subdev, lnkcmp,
254 			init.outp = &dp->outp.info;
255 			init.or   = ior->id;
256 			init.link = ior->asy.link;
257 		);
258 	}
259 
260 	ret = ior->func->dp.links(ior, dp->aux);
261 	if (ret) {
262 		if (ret < 0) {
263 			OUTP_ERR(&dp->outp, "train failed with %d", ret);
264 			return ret;
265 		}
266 		return 0;
267 	}
268 
269 	ior->func->dp.power(ior, ior->dp.nr);
270 
271 	/* Set desired link configuration on the sink. */
272 	sink[0] = ior->dp.bw;
273 	sink[1] = ior->dp.nr;
274 	if (ior->dp.ef)
275 		sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;
276 
277 	ret = nvkm_wraux(dp->aux, DPCD_LC00_LINK_BW_SET, sink, 2);
278 	if (ret)
279 		return ret;
280 
281 	/* Attempt to train the link in this configuration. */
282 	memset(lt.stat, 0x00, sizeof(lt.stat));
283 	ret = nvkm_dp_train_cr(&lt);
284 	if (ret == 0)
285 		ret = nvkm_dp_train_eq(&lt);
286 	nvkm_dp_train_pattern(&lt, 0);
287 	return ret;
288 }
289 
290 static void
291 nvkm_dp_train_fini(struct nvkm_dp *dp)
292 {
293 	/* Execute AfterLinkTraining script from DP Info table. */
294 	nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[1],
295 		init.outp = &dp->outp.info;
296 		init.or   = dp->outp.ior->id;
297 		init.link = dp->outp.ior->asy.link;
298 	);
299 }
300 
301 static void
302 nvkm_dp_train_init(struct nvkm_dp *dp)
303 {
304 	/* Execute EnableSpread/DisableSpread script from DP Info table. */
305 	if (dp->dpcd[DPCD_RC03] & DPCD_RC03_MAX_DOWNSPREAD) {
306 		nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[2],
307 			init.outp = &dp->outp.info;
308 			init.or   = dp->outp.ior->id;
309 			init.link = dp->outp.ior->asy.link;
310 		);
311 	} else {
312 		nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[3],
313 			init.outp = &dp->outp.info;
314 			init.or   = dp->outp.ior->id;
315 			init.link = dp->outp.ior->asy.link;
316 		);
317 	}
318 
319 	/* Execute BeforeLinkTraining script from DP Info table. */
320 	nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[0],
321 		init.outp = &dp->outp.info;
322 		init.or   = dp->outp.ior->id;
323 		init.link = dp->outp.ior->asy.link;
324 	);
325 }
326 
327 static const struct dp_rates {
328 	u32 rate;
329 	u8  bw;
330 	u8  nr;
331 } nvkm_dp_rates[] = {
332 	{ 2160000, 0x14, 4 },
333 	{ 1080000, 0x0a, 4 },
334 	{ 1080000, 0x14, 2 },
335 	{  648000, 0x06, 4 },
336 	{  540000, 0x0a, 2 },
337 	{  540000, 0x14, 1 },
338 	{  324000, 0x06, 2 },
339 	{  270000, 0x0a, 1 },
340 	{  162000, 0x06, 1 },
341 	{}
342 };
343 
344 static int
345 nvkm_dp_train(struct nvkm_dp *dp, u32 dataKBps)
346 {
347 	struct nvkm_ior *ior = dp->outp.ior;
348 	const u8 sink_nr = dp->dpcd[DPCD_RC02] & DPCD_RC02_MAX_LANE_COUNT;
349 	const u8 sink_bw = dp->dpcd[DPCD_RC01_MAX_LINK_RATE];
350 	const u8 outp_nr = dp->outp.info.dpconf.link_nr;
351 	const u8 outp_bw = dp->outp.info.dpconf.link_bw;
352 	const struct dp_rates *failsafe = NULL, *cfg;
353 	int ret = -EINVAL;
354 	u8  pwr;
355 
356 	/* Find the lowest configuration of the OR that can support
357 	 * the required link rate.
358 	 *
359 	 * We will refuse to program the OR to lower rates, even if
360 	 * link training fails at higher rates (or even if the sink
361 	 * can't support the rate at all, though the DD is supposed
362 	 * to prevent such situations from happening).
363 	 *
364 	 * Attempting to do so can cause the entire display to hang,
365 	 * and it's better to have a failed modeset than that.
366 	 */
367 	for (cfg = nvkm_dp_rates; cfg->rate; cfg++) {
368 		if (cfg->nr <= outp_nr && cfg->bw <= outp_bw) {
369 			/* Try to respect sink limits too when selecting
370 			 * lowest link configuration.
371 			 */
372 			if (!failsafe ||
373 			    (cfg->nr <= sink_nr && cfg->bw <= sink_bw))
374 				failsafe = cfg;
375 		}
376 
377 		if (failsafe && cfg[1].rate < dataKBps)
378 			break;
379 	}
380 
381 	if (WARN_ON(!failsafe))
382 		return ret;
383 
384 	/* Ensure sink is not in a low-power state. */
385 	if (!nvkm_rdaux(dp->aux, DPCD_SC00, &pwr, 1)) {
386 		if ((pwr & DPCD_SC00_SET_POWER) != DPCD_SC00_SET_POWER_D0) {
387 			pwr &= ~DPCD_SC00_SET_POWER;
388 			pwr |=  DPCD_SC00_SET_POWER_D0;
389 			nvkm_wraux(dp->aux, DPCD_SC00, &pwr, 1);
390 		}
391 	}
392 
393 	/* Link training. */
394 	OUTP_DBG(&dp->outp, "training (min: %d x %d MB/s)",
395 		 failsafe->nr, failsafe->bw * 27);
396 	nvkm_dp_train_init(dp);
397 	for (cfg = nvkm_dp_rates; ret < 0 && cfg <= failsafe; cfg++) {
398 		/* Skip configurations not supported by both OR and sink. */
399 		if ((cfg->nr > outp_nr || cfg->bw > outp_bw ||
400 		     cfg->nr > sink_nr || cfg->bw > sink_bw)) {
401 			if (cfg != failsafe)
402 				continue;
403 			OUTP_ERR(&dp->outp, "link rate unsupported by sink");
404 		}
405 		ior->dp.mst = dp->lt.mst;
406 		ior->dp.ef = dp->dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP;
407 		ior->dp.bw = cfg->bw;
408 		ior->dp.nr = cfg->nr;
409 
410 		/* Program selected link configuration. */
411 		ret = nvkm_dp_train_links(dp);
412 	}
413 	nvkm_dp_train_fini(dp);
414 	if (ret < 0)
415 		OUTP_ERR(&dp->outp, "training failed");
416 	else
417 		OUTP_DBG(&dp->outp, "training done");
418 	atomic_set(&dp->lt.done, 1);
419 	return ret;
420 }
421 
422 static void
423 nvkm_dp_disable(struct nvkm_outp *outp, struct nvkm_ior *ior)
424 {
425 	struct nvkm_dp *dp = nvkm_dp(outp);
426 
427 	/* Execute DisableLT script from DP Info Table. */
428 	nvbios_init(&ior->disp->engine.subdev, dp->info.script[4],
429 		init.outp = &dp->outp.info;
430 		init.or   = ior->id;
431 		init.link = ior->arm.link;
432 	);
433 }
434 
435 static void
436 nvkm_dp_release(struct nvkm_outp *outp)
437 {
438 	struct nvkm_dp *dp = nvkm_dp(outp);
439 
440 	/* Prevent link from being retrained if sink sends an IRQ. */
441 	atomic_set(&dp->lt.done, 0);
442 	dp->outp.ior->dp.nr = 0;
443 }
444 
445 static int
446 nvkm_dp_acquire(struct nvkm_outp *outp)
447 {
448 	struct nvkm_dp *dp = nvkm_dp(outp);
449 	struct nvkm_ior *ior = dp->outp.ior;
450 	struct nvkm_head *head;
451 	bool retrain = true;
452 	u32 datakbps = 0;
453 	u32 dataKBps;
454 	u32 linkKBps;
455 	u8  stat[3];
456 	int ret, i;
457 
458 	mutex_lock(&dp->mutex);
459 
460 	/* Check that link configuration meets current requirements. */
461 	list_for_each_entry(head, &outp->disp->head, head) {
462 		if (ior->asy.head & (1 << head->id)) {
463 			u32 khz = (head->asy.hz >> ior->asy.rgdiv) / 1000;
464 			datakbps += khz * head->asy.or.depth;
465 		}
466 	}
467 
468 	linkKBps = ior->dp.bw * 27000 * ior->dp.nr;
469 	dataKBps = DIV_ROUND_UP(datakbps, 8);
470 	OUTP_DBG(&dp->outp, "data %d KB/s link %d KB/s mst %d->%d",
471 		 dataKBps, linkKBps, ior->dp.mst, dp->lt.mst);
472 	if (linkKBps < dataKBps || ior->dp.mst != dp->lt.mst) {
473 		OUTP_DBG(&dp->outp, "link requirements changed");
474 		goto done;
475 	}
476 
477 	/* Check that link is still trained. */
478 	ret = nvkm_rdaux(dp->aux, DPCD_LS02, stat, 3);
479 	if (ret) {
480 		OUTP_DBG(&dp->outp,
481 			 "failed to read link status, assuming no sink");
482 		goto done;
483 	}
484 
485 	if (stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE) {
486 		for (i = 0; i < ior->dp.nr; i++) {
487 			u8 lane = (stat[i >> 1] >> ((i & 1) * 4)) & 0x0f;
488 			if (!(lane & DPCD_LS02_LANE0_CR_DONE) ||
489 			    !(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
490 			    !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED)) {
491 				OUTP_DBG(&dp->outp,
492 					 "lane %d not equalised", lane);
493 				goto done;
494 			}
495 		}
496 		retrain = false;
497 	} else {
498 		OUTP_DBG(&dp->outp, "no inter-lane alignment");
499 	}
500 
501 done:
502 	if (retrain || !atomic_read(&dp->lt.done))
503 		ret = nvkm_dp_train(dp, dataKBps);
504 	mutex_unlock(&dp->mutex);
505 	return ret;
506 }
507 
508 static bool
509 nvkm_dp_enable(struct nvkm_dp *dp, bool enable)
510 {
511 	struct nvkm_i2c_aux *aux = dp->aux;
512 
513 	if (enable) {
514 		if (!dp->present) {
515 			OUTP_DBG(&dp->outp, "aux power -> always");
516 			nvkm_i2c_aux_monitor(aux, true);
517 			dp->present = true;
518 		}
519 
520 		if (!nvkm_rdaux(aux, DPCD_RC00_DPCD_REV, dp->dpcd,
521 				sizeof(dp->dpcd)))
522 			return true;
523 	}
524 
525 	if (dp->present) {
526 		OUTP_DBG(&dp->outp, "aux power -> demand");
527 		nvkm_i2c_aux_monitor(aux, false);
528 		dp->present = false;
529 	}
530 
531 	atomic_set(&dp->lt.done, 0);
532 	return false;
533 }
534 
535 static int
536 nvkm_dp_hpd(struct nvkm_notify *notify)
537 {
538 	const struct nvkm_i2c_ntfy_rep *line = notify->data;
539 	struct nvkm_dp *dp = container_of(notify, typeof(*dp), hpd);
540 	struct nvkm_conn *conn = dp->outp.conn;
541 	struct nvkm_disp *disp = dp->outp.disp;
542 	struct nvif_notify_conn_rep_v0 rep = {};
543 
544 	OUTP_DBG(&dp->outp, "HPD: %d", line->mask);
545 	if (line->mask & NVKM_I2C_IRQ) {
546 		if (atomic_read(&dp->lt.done))
547 			dp->outp.func->acquire(&dp->outp);
548 		rep.mask |= NVIF_NOTIFY_CONN_V0_IRQ;
549 	} else {
550 		nvkm_dp_enable(dp, true);
551 	}
552 
553 	if (line->mask & NVKM_I2C_UNPLUG)
554 		rep.mask |= NVIF_NOTIFY_CONN_V0_UNPLUG;
555 	if (line->mask & NVKM_I2C_PLUG)
556 		rep.mask |= NVIF_NOTIFY_CONN_V0_PLUG;
557 
558 	nvkm_event_send(&disp->hpd, rep.mask, conn->index, &rep, sizeof(rep));
559 	return NVKM_NOTIFY_KEEP;
560 }
561 
562 static void
563 nvkm_dp_fini(struct nvkm_outp *outp)
564 {
565 	struct nvkm_dp *dp = nvkm_dp(outp);
566 	nvkm_notify_put(&dp->hpd);
567 	nvkm_dp_enable(dp, false);
568 }
569 
570 static void
571 nvkm_dp_init(struct nvkm_outp *outp)
572 {
573 	struct nvkm_gpio *gpio = outp->disp->engine.subdev.device->gpio;
574 	struct nvkm_dp *dp = nvkm_dp(outp);
575 
576 	nvkm_notify_put(&dp->outp.conn->hpd);
577 
578 	/* eDP panels need powering on by us (if the VBIOS doesn't default it
579 	 * to on) before doing any AUX channel transactions.  LVDS panel power
580 	 * is handled by the SOR itself, and not required for LVDS DDC.
581 	 */
582 	if (dp->outp.conn->info.type == DCB_CONNECTOR_eDP) {
583 		int power = nvkm_gpio_get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);
584 		if (power == 0)
585 			nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);
586 
587 		/* We delay here unconditionally, even if already powered,
588 		 * because some laptop panels having a significant resume
589 		 * delay before the panel begins responding.
590 		 *
591 		 * This is likely a bit of a hack, but no better idea for
592 		 * handling this at the moment.
593 		 */
594 		msleep(300);
595 
596 		/* If the eDP panel can't be detected, we need to restore
597 		 * the panel power GPIO to avoid breaking another output.
598 		 */
599 		if (!nvkm_dp_enable(dp, true) && power == 0)
600 			nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 0);
601 	} else {
602 		nvkm_dp_enable(dp, true);
603 	}
604 
605 	nvkm_notify_get(&dp->hpd);
606 }
607 
608 static void *
609 nvkm_dp_dtor(struct nvkm_outp *outp)
610 {
611 	struct nvkm_dp *dp = nvkm_dp(outp);
612 	nvkm_notify_fini(&dp->hpd);
613 	return dp;
614 }
615 
616 static const struct nvkm_outp_func
617 nvkm_dp_func = {
618 	.dtor = nvkm_dp_dtor,
619 	.init = nvkm_dp_init,
620 	.fini = nvkm_dp_fini,
621 	.acquire = nvkm_dp_acquire,
622 	.release = nvkm_dp_release,
623 	.disable = nvkm_dp_disable,
624 };
625 
626 static int
627 nvkm_dp_ctor(struct nvkm_disp *disp, int index, struct dcb_output *dcbE,
628 	     struct nvkm_i2c_aux *aux, struct nvkm_dp *dp)
629 {
630 	struct nvkm_device *device = disp->engine.subdev.device;
631 	struct nvkm_bios *bios = device->bios;
632 	struct nvkm_i2c *i2c = device->i2c;
633 	u8  hdr, cnt, len;
634 	u32 data;
635 	int ret;
636 
637 	ret = nvkm_outp_ctor(&nvkm_dp_func, disp, index, dcbE, &dp->outp);
638 	if (ret)
639 		return ret;
640 
641 	dp->aux = aux;
642 	if (!dp->aux) {
643 		OUTP_ERR(&dp->outp, "no aux");
644 		return -EINVAL;
645 	}
646 
647 	/* bios data is not optional */
648 	data = nvbios_dpout_match(bios, dp->outp.info.hasht,
649 				  dp->outp.info.hashm, &dp->version,
650 				  &hdr, &cnt, &len, &dp->info);
651 	if (!data) {
652 		OUTP_ERR(&dp->outp, "no bios dp data");
653 		return -EINVAL;
654 	}
655 
656 	OUTP_DBG(&dp->outp, "bios dp %02x %02x %02x %02x",
657 		 dp->version, hdr, cnt, len);
658 
659 	/* hotplug detect, replaces gpio-based mechanism with aux events */
660 	ret = nvkm_notify_init(NULL, &i2c->event, nvkm_dp_hpd, true,
661 			       &(struct nvkm_i2c_ntfy_req) {
662 				.mask = NVKM_I2C_PLUG | NVKM_I2C_UNPLUG |
663 					NVKM_I2C_IRQ,
664 				.port = dp->aux->id,
665 			       },
666 			       sizeof(struct nvkm_i2c_ntfy_req),
667 			       sizeof(struct nvkm_i2c_ntfy_rep),
668 			       &dp->hpd);
669 	if (ret) {
670 		OUTP_ERR(&dp->outp, "error monitoring aux hpd: %d", ret);
671 		return ret;
672 	}
673 
674 	mutex_init(&dp->mutex);
675 	atomic_set(&dp->lt.done, 0);
676 	return 0;
677 }
678 
679 int
680 nvkm_dp_new(struct nvkm_disp *disp, int index, struct dcb_output *dcbE,
681 	    struct nvkm_outp **poutp)
682 {
683 	struct nvkm_i2c *i2c = disp->engine.subdev.device->i2c;
684 	struct nvkm_i2c_aux *aux;
685 	struct nvkm_dp *dp;
686 
687 	if (dcbE->location == 0)
688 		aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_CCB(dcbE->i2c_index));
689 	else
690 		aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_EXT(dcbE->extdev));
691 
692 	if (!(dp = kzalloc(sizeof(*dp), GFP_KERNEL)))
693 		return -ENOMEM;
694 	*poutp = &dp->outp;
695 
696 	return nvkm_dp_ctor(disp, index, dcbE, aux, dp);
697 }
698