xref: /linux/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c (revision f9bff0e31881d03badf191d3b0005839391f5f2b)
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 /* IED scripts are no longer used by UEFI/RM from Ampere, but have been updated for
37  * the x86 option ROM.  However, the relevant VBIOS table versions weren't modified,
38  * so we're unable to detect this in a nice way.
39  */
40 #define AMPERE_IED_HACK(disp) ((disp)->engine.subdev.device->card_type >= GA100)
41 
42 struct lt_state {
43 	struct nvkm_outp *outp;
44 
45 	int repeaters;
46 	int repeater;
47 
48 	u8  stat[6];
49 	u8  conf[4];
50 	bool pc2;
51 	u8  pc2stat;
52 	u8  pc2conf[2];
53 };
54 
55 static int
56 nvkm_dp_train_sense(struct lt_state *lt, bool pc, u32 delay)
57 {
58 	struct nvkm_outp *outp = lt->outp;
59 	u32 addr;
60 	int ret;
61 
62 	usleep_range(delay, delay * 2);
63 
64 	if (lt->repeater)
65 		addr = DPCD_LTTPR_LANE0_1_STATUS(lt->repeater);
66 	else
67 		addr = DPCD_LS02;
68 
69 	ret = nvkm_rdaux(outp->dp.aux, addr, &lt->stat[0], 3);
70 	if (ret)
71 		return ret;
72 
73 	if (lt->repeater)
74 		addr = DPCD_LTTPR_LANE0_1_ADJUST(lt->repeater);
75 	else
76 		addr = DPCD_LS06;
77 
78 	ret = nvkm_rdaux(outp->dp.aux, addr, &lt->stat[4], 2);
79 	if (ret)
80 		return ret;
81 
82 	if (pc) {
83 		ret = nvkm_rdaux(outp->dp.aux, DPCD_LS0C, &lt->pc2stat, 1);
84 		if (ret)
85 			lt->pc2stat = 0x00;
86 
87 		OUTP_TRACE(outp, "status %6ph pc2 %02x", lt->stat, lt->pc2stat);
88 	} else {
89 		OUTP_TRACE(outp, "status %6ph", lt->stat);
90 	}
91 
92 	return 0;
93 }
94 
95 static int
96 nvkm_dp_train_drive(struct lt_state *lt, bool pc)
97 {
98 	struct nvkm_outp *outp = lt->outp;
99 	struct nvkm_ior *ior = outp->ior;
100 	struct nvkm_bios *bios = ior->disp->engine.subdev.device->bios;
101 	struct nvbios_dpout info;
102 	struct nvbios_dpcfg ocfg;
103 	u8  ver, hdr, cnt, len;
104 	u32 addr;
105 	u32 data;
106 	int ret, i;
107 
108 	for (i = 0; i < ior->dp.nr; i++) {
109 		u8 lane = (lt->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
110 		u8 lpc2 = (lt->pc2stat >> (i * 2)) & 0x3;
111 		u8 lpre = (lane & 0x0c) >> 2;
112 		u8 lvsw = (lane & 0x03) >> 0;
113 		u8 hivs = 3 - lpre;
114 		u8 hipe = 3;
115 		u8 hipc = 3;
116 
117 		if (lpc2 >= hipc)
118 			lpc2 = hipc | DPCD_LC0F_LANE0_MAX_POST_CURSOR2_REACHED;
119 		if (lpre >= hipe) {
120 			lpre = hipe | DPCD_LC03_MAX_SWING_REACHED; /* yes. */
121 			lvsw = hivs = 3 - (lpre & 3);
122 		} else
123 		if (lvsw >= hivs) {
124 			lvsw = hivs | DPCD_LC03_MAX_SWING_REACHED;
125 		}
126 
127 		lt->conf[i] = (lpre << 3) | lvsw;
128 		lt->pc2conf[i >> 1] |= lpc2 << ((i & 1) * 4);
129 
130 		OUTP_TRACE(outp, "config lane %d %02x %02x", i, lt->conf[i], lpc2);
131 
132 		if (lt->repeater != lt->repeaters)
133 			continue;
134 
135 		data = nvbios_dpout_match(bios, outp->info.hasht, outp->info.hashm,
136 					  &ver, &hdr, &cnt, &len, &info);
137 		if (!data)
138 			continue;
139 
140 		data = nvbios_dpcfg_match(bios, data, lpc2 & 3, lvsw & 3, lpre & 3,
141 					  &ver, &hdr, &cnt, &len, &ocfg);
142 		if (!data)
143 			continue;
144 
145 		ior->func->dp->drive(ior, i, ocfg.pc, ocfg.dc, ocfg.pe, ocfg.tx_pu);
146 	}
147 
148 	if (lt->repeater)
149 		addr = DPCD_LTTPR_LANE0_SET(lt->repeater);
150 	else
151 		addr = DPCD_LC03(0);
152 
153 	ret = nvkm_wraux(outp->dp.aux, addr, lt->conf, 4);
154 	if (ret)
155 		return ret;
156 
157 	if (pc) {
158 		ret = nvkm_wraux(outp->dp.aux, DPCD_LC0F, lt->pc2conf, 2);
159 		if (ret)
160 			return ret;
161 	}
162 
163 	return 0;
164 }
165 
166 static void
167 nvkm_dp_train_pattern(struct lt_state *lt, u8 pattern)
168 {
169 	struct nvkm_outp *outp = lt->outp;
170 	u32 addr;
171 	u8 sink_tp;
172 
173 	OUTP_TRACE(outp, "training pattern %d", pattern);
174 	outp->ior->func->dp->pattern(outp->ior, pattern);
175 
176 	if (lt->repeater)
177 		addr = DPCD_LTTPR_PATTERN_SET(lt->repeater);
178 	else
179 		addr = DPCD_LC02;
180 
181 	nvkm_rdaux(outp->dp.aux, addr, &sink_tp, 1);
182 	sink_tp &= ~DPCD_LC02_TRAINING_PATTERN_SET;
183 	sink_tp |= (pattern != 4) ? pattern : 7;
184 
185 	if (pattern != 0)
186 		sink_tp |=  DPCD_LC02_SCRAMBLING_DISABLE;
187 	else
188 		sink_tp &= ~DPCD_LC02_SCRAMBLING_DISABLE;
189 	nvkm_wraux(outp->dp.aux, addr, &sink_tp, 1);
190 }
191 
192 static int
193 nvkm_dp_train_eq(struct lt_state *lt)
194 {
195 	struct nvkm_i2c_aux *aux = lt->outp->dp.aux;
196 	bool eq_done = false, cr_done = true;
197 	int tries = 0, usec = 0, i;
198 	u8 data;
199 
200 	if (lt->repeater) {
201 		if (!nvkm_rdaux(aux, DPCD_LTTPR_AUX_RD_INTERVAL(lt->repeater), &data, sizeof(data)))
202 			usec = (data & DPCD_RC0E_AUX_RD_INTERVAL) * 4000;
203 
204 		nvkm_dp_train_pattern(lt, 4);
205 	} else {
206 		if (lt->outp->dp.dpcd[DPCD_RC00_DPCD_REV] >= 0x14 &&
207 		    lt->outp->dp.dpcd[DPCD_RC03] & DPCD_RC03_TPS4_SUPPORTED)
208 			nvkm_dp_train_pattern(lt, 4);
209 		else
210 		if (lt->outp->dp.dpcd[DPCD_RC00_DPCD_REV] >= 0x12 &&
211 		    lt->outp->dp.dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED)
212 			nvkm_dp_train_pattern(lt, 3);
213 		else
214 			nvkm_dp_train_pattern(lt, 2);
215 
216 		usec = (lt->outp->dp.dpcd[DPCD_RC0E] & DPCD_RC0E_AUX_RD_INTERVAL) * 4000;
217 	}
218 
219 	do {
220 		if ((tries &&
221 		    nvkm_dp_train_drive(lt, lt->pc2)) ||
222 		    nvkm_dp_train_sense(lt, lt->pc2, usec ? usec : 400))
223 			break;
224 
225 		eq_done = !!(lt->stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE);
226 		for (i = 0; i < lt->outp->ior->dp.nr && eq_done; i++) {
227 			u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
228 			if (!(lane & DPCD_LS02_LANE0_CR_DONE))
229 				cr_done = false;
230 			if (!(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
231 			    !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED))
232 				eq_done = false;
233 		}
234 	} while (!eq_done && cr_done && ++tries <= 5);
235 
236 	return eq_done ? 0 : -1;
237 }
238 
239 static int
240 nvkm_dp_train_cr(struct lt_state *lt)
241 {
242 	bool cr_done = false, abort = false;
243 	int voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
244 	int tries = 0, usec = 0, i;
245 
246 	nvkm_dp_train_pattern(lt, 1);
247 
248 	if (lt->outp->dp.dpcd[DPCD_RC00_DPCD_REV] < 0x14 && !lt->repeater)
249 		usec = (lt->outp->dp.dpcd[DPCD_RC0E] & DPCD_RC0E_AUX_RD_INTERVAL) * 4000;
250 
251 	do {
252 		if (nvkm_dp_train_drive(lt, false) ||
253 		    nvkm_dp_train_sense(lt, false, usec ? usec : 100))
254 			break;
255 
256 		cr_done = true;
257 		for (i = 0; i < lt->outp->ior->dp.nr; i++) {
258 			u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
259 			if (!(lane & DPCD_LS02_LANE0_CR_DONE)) {
260 				cr_done = false;
261 				if (lt->conf[i] & DPCD_LC03_MAX_SWING_REACHED)
262 					abort = true;
263 				break;
264 			}
265 		}
266 
267 		if ((lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET) != voltage) {
268 			voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
269 			tries = 0;
270 		}
271 	} while (!cr_done && !abort && ++tries < 5);
272 
273 	return cr_done ? 0 : -1;
274 }
275 
276 static int
277 nvkm_dp_train_link(struct nvkm_outp *outp, int rate)
278 {
279 	struct nvkm_ior *ior = outp->ior;
280 	struct lt_state lt = {
281 		.outp = outp,
282 		.pc2 = outp->dp.dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED,
283 	};
284 	u8 sink[2], data;
285 	int ret;
286 
287 	OUTP_DBG(outp, "training %dx%02x", ior->dp.nr, ior->dp.bw);
288 
289 	/* Select LTTPR non-transparent mode if we have a valid configuration,
290 	 * use transparent mode otherwise.
291 	 */
292 	if (outp->dp.lttpr[0] >= 0x14) {
293 		data = DPCD_LTTPR_MODE_TRANSPARENT;
294 		nvkm_wraux(outp->dp.aux, DPCD_LTTPR_MODE, &data, sizeof(data));
295 
296 		if (outp->dp.lttprs) {
297 			data = DPCD_LTTPR_MODE_NON_TRANSPARENT;
298 			nvkm_wraux(outp->dp.aux, DPCD_LTTPR_MODE, &data, sizeof(data));
299 			lt.repeaters = outp->dp.lttprs;
300 		}
301 	}
302 
303 	/* Set desired link configuration on the sink. */
304 	sink[0] = (outp->dp.rate[rate].dpcd < 0) ? ior->dp.bw : 0;
305 	sink[1] = ior->dp.nr;
306 	if (ior->dp.ef)
307 		sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;
308 
309 	ret = nvkm_wraux(outp->dp.aux, DPCD_LC00_LINK_BW_SET, sink, 2);
310 	if (ret)
311 		return ret;
312 
313 	if (outp->dp.rate[rate].dpcd >= 0) {
314 		ret = nvkm_rdaux(outp->dp.aux, DPCD_LC15_LINK_RATE_SET, &sink[0], sizeof(sink[0]));
315 		if (ret)
316 			return ret;
317 
318 		sink[0] &= ~DPCD_LC15_LINK_RATE_SET_MASK;
319 		sink[0] |= outp->dp.rate[rate].dpcd;
320 
321 		ret = nvkm_wraux(outp->dp.aux, DPCD_LC15_LINK_RATE_SET, &sink[0], sizeof(sink[0]));
322 		if (ret)
323 			return ret;
324 	}
325 
326 	/* Attempt to train the link in this configuration. */
327 	for (lt.repeater = lt.repeaters; lt.repeater >= 0; lt.repeater--) {
328 		if (lt.repeater)
329 			OUTP_DBG(outp, "training LTTPR%d", lt.repeater);
330 		else
331 			OUTP_DBG(outp, "training sink");
332 
333 		memset(lt.stat, 0x00, sizeof(lt.stat));
334 		ret = nvkm_dp_train_cr(&lt);
335 		if (ret == 0)
336 			ret = nvkm_dp_train_eq(&lt);
337 		nvkm_dp_train_pattern(&lt, 0);
338 	}
339 
340 	return ret;
341 }
342 
343 static int
344 nvkm_dp_train_links(struct nvkm_outp *outp, int rate)
345 {
346 	struct nvkm_ior *ior = outp->ior;
347 	struct nvkm_disp *disp = outp->disp;
348 	struct nvkm_subdev *subdev = &disp->engine.subdev;
349 	struct nvkm_bios *bios = subdev->device->bios;
350 	u32 lnkcmp;
351 	int ret;
352 
353 	OUTP_DBG(outp, "programming link for %dx%02x", ior->dp.nr, ior->dp.bw);
354 
355 	/* Intersect misc. capabilities of the OR and sink. */
356 	if (disp->engine.subdev.device->chipset < 0x110)
357 		outp->dp.dpcd[DPCD_RC03] &= ~DPCD_RC03_TPS4_SUPPORTED;
358 	if (disp->engine.subdev.device->chipset < 0xd0)
359 		outp->dp.dpcd[DPCD_RC02] &= ~DPCD_RC02_TPS3_SUPPORTED;
360 
361 	if (AMPERE_IED_HACK(disp) && (lnkcmp = outp->dp.info.script[0])) {
362 		/* Execute BeforeLinkTraining script from DP Info table. */
363 		while (ior->dp.bw < nvbios_rd08(bios, lnkcmp))
364 			lnkcmp += 3;
365 		lnkcmp = nvbios_rd16(bios, lnkcmp + 1);
366 
367 		nvbios_init(&outp->disp->engine.subdev, lnkcmp,
368 			init.outp = &outp->info;
369 			init.or   = ior->id;
370 			init.link = ior->asy.link;
371 		);
372 	}
373 
374 	/* Set desired link configuration on the source. */
375 	if ((lnkcmp = outp->dp.info.lnkcmp)) {
376 		if (outp->dp.version < 0x30) {
377 			while ((ior->dp.bw * 2700) < nvbios_rd16(bios, lnkcmp))
378 				lnkcmp += 4;
379 			lnkcmp = nvbios_rd16(bios, lnkcmp + 2);
380 		} else {
381 			while (ior->dp.bw < nvbios_rd08(bios, lnkcmp))
382 				lnkcmp += 3;
383 			lnkcmp = nvbios_rd16(bios, lnkcmp + 1);
384 		}
385 
386 		nvbios_init(subdev, lnkcmp,
387 			init.outp = &outp->info;
388 			init.or   = ior->id;
389 			init.link = ior->asy.link;
390 		);
391 	}
392 
393 	ret = ior->func->dp->links(ior, outp->dp.aux);
394 	if (ret) {
395 		if (ret < 0) {
396 			OUTP_ERR(outp, "train failed with %d", ret);
397 			return ret;
398 		}
399 		return 0;
400 	}
401 
402 	ior->func->dp->power(ior, ior->dp.nr);
403 
404 	/* Attempt to train the link in this configuration. */
405 	return nvkm_dp_train_link(outp, rate);
406 }
407 
408 static void
409 nvkm_dp_train_fini(struct nvkm_outp *outp)
410 {
411 	/* Execute AfterLinkTraining script from DP Info table. */
412 	nvbios_init(&outp->disp->engine.subdev, outp->dp.info.script[1],
413 		init.outp = &outp->info;
414 		init.or   = outp->ior->id;
415 		init.link = outp->ior->asy.link;
416 	);
417 }
418 
419 static void
420 nvkm_dp_train_init(struct nvkm_outp *outp)
421 {
422 	/* Execute EnableSpread/DisableSpread script from DP Info table. */
423 	if (outp->dp.dpcd[DPCD_RC03] & DPCD_RC03_MAX_DOWNSPREAD) {
424 		nvbios_init(&outp->disp->engine.subdev, outp->dp.info.script[2],
425 			init.outp = &outp->info;
426 			init.or   = outp->ior->id;
427 			init.link = outp->ior->asy.link;
428 		);
429 	} else {
430 		nvbios_init(&outp->disp->engine.subdev, outp->dp.info.script[3],
431 			init.outp = &outp->info;
432 			init.or   = outp->ior->id;
433 			init.link = outp->ior->asy.link;
434 		);
435 	}
436 
437 	if (!AMPERE_IED_HACK(outp->disp)) {
438 		/* Execute BeforeLinkTraining script from DP Info table. */
439 		nvbios_init(&outp->disp->engine.subdev, outp->dp.info.script[0],
440 			init.outp = &outp->info;
441 			init.or   = outp->ior->id;
442 			init.link = outp->ior->asy.link;
443 		);
444 	}
445 }
446 
447 static int
448 nvkm_dp_train(struct nvkm_outp *outp, u32 dataKBps)
449 {
450 	struct nvkm_ior *ior = outp->ior;
451 	int ret = -EINVAL, nr, rate;
452 	u8  pwr;
453 
454 	/* Retraining link?  Skip source configuration, it can mess up the active modeset. */
455 	if (atomic_read(&outp->dp.lt.done)) {
456 		for (rate = 0; rate < outp->dp.rates; rate++) {
457 			if (outp->dp.rate[rate].rate == ior->dp.bw * 27000)
458 				return nvkm_dp_train_link(outp, ret);
459 		}
460 		WARN_ON(1);
461 		return -EINVAL;
462 	}
463 
464 	/* Ensure sink is not in a low-power state. */
465 	if (!nvkm_rdaux(outp->dp.aux, DPCD_SC00, &pwr, 1)) {
466 		if ((pwr & DPCD_SC00_SET_POWER) != DPCD_SC00_SET_POWER_D0) {
467 			pwr &= ~DPCD_SC00_SET_POWER;
468 			pwr |=  DPCD_SC00_SET_POWER_D0;
469 			nvkm_wraux(outp->dp.aux, DPCD_SC00, &pwr, 1);
470 		}
471 	}
472 
473 	ior->dp.mst = outp->dp.lt.mst;
474 	ior->dp.ef = outp->dp.dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP;
475 	ior->dp.nr = 0;
476 
477 	/* Link training. */
478 	OUTP_DBG(outp, "training");
479 	nvkm_dp_train_init(outp);
480 
481 	/* Validate and train at configuration requested (if any) on ACQUIRE. */
482 	if (outp->dp.lt.nr) {
483 		for (nr = outp->dp.links; ret < 0 && nr; nr >>= 1) {
484 			for (rate = 0; nr == outp->dp.lt.nr && rate < outp->dp.rates; rate++) {
485 				if (outp->dp.rate[rate].rate / 27000 == outp->dp.lt.bw) {
486 					ior->dp.bw = outp->dp.rate[rate].rate / 27000;
487 					ior->dp.nr = nr;
488 					ret = nvkm_dp_train_links(outp, rate);
489 				}
490 			}
491 		}
492 	}
493 
494 	/* Otherwise, loop through all valid link configurations that support the data rate. */
495 	for (nr = outp->dp.links; ret < 0 && nr; nr >>= 1) {
496 		for (rate = 0; ret < 0 && rate < outp->dp.rates; rate++) {
497 			if (outp->dp.rate[rate].rate * nr >= dataKBps || WARN_ON(!ior->dp.nr)) {
498 				/* Program selected link configuration. */
499 				ior->dp.bw = outp->dp.rate[rate].rate / 27000;
500 				ior->dp.nr = nr;
501 				ret = nvkm_dp_train_links(outp, rate);
502 			}
503 		}
504 	}
505 
506 	/* Finish up. */
507 	nvkm_dp_train_fini(outp);
508 	if (ret < 0)
509 		OUTP_ERR(outp, "training failed");
510 	else
511 		OUTP_DBG(outp, "training done");
512 	atomic_set(&outp->dp.lt.done, 1);
513 	return ret;
514 }
515 
516 void
517 nvkm_dp_disable(struct nvkm_outp *outp, struct nvkm_ior *ior)
518 {
519 	/* Execute DisableLT script from DP Info Table. */
520 	nvbios_init(&ior->disp->engine.subdev, outp->dp.info.script[4],
521 		init.outp = &outp->info;
522 		init.or   = ior->id;
523 		init.link = ior->arm.link;
524 	);
525 }
526 
527 static void
528 nvkm_dp_release(struct nvkm_outp *outp)
529 {
530 	/* Prevent link from being retrained if sink sends an IRQ. */
531 	atomic_set(&outp->dp.lt.done, 0);
532 	outp->ior->dp.nr = 0;
533 }
534 
535 static int
536 nvkm_dp_acquire(struct nvkm_outp *outp)
537 {
538 	struct nvkm_ior *ior = outp->ior;
539 	struct nvkm_head *head;
540 	bool retrain = true;
541 	u32 datakbps = 0;
542 	u32 dataKBps;
543 	u32 linkKBps;
544 	u8  stat[3];
545 	int ret, i;
546 
547 	mutex_lock(&outp->dp.mutex);
548 
549 	/* Check that link configuration meets current requirements. */
550 	list_for_each_entry(head, &outp->disp->heads, head) {
551 		if (ior->asy.head & (1 << head->id)) {
552 			u32 khz = (head->asy.hz >> ior->asy.rgdiv) / 1000;
553 			datakbps += khz * head->asy.or.depth;
554 		}
555 	}
556 
557 	linkKBps = ior->dp.bw * 27000 * ior->dp.nr;
558 	dataKBps = DIV_ROUND_UP(datakbps, 8);
559 	OUTP_DBG(outp, "data %d KB/s link %d KB/s mst %d->%d",
560 		 dataKBps, linkKBps, ior->dp.mst, outp->dp.lt.mst);
561 	if (linkKBps < dataKBps || ior->dp.mst != outp->dp.lt.mst) {
562 		OUTP_DBG(outp, "link requirements changed");
563 		goto done;
564 	}
565 
566 	/* Check that link is still trained. */
567 	ret = nvkm_rdaux(outp->dp.aux, DPCD_LS02, stat, 3);
568 	if (ret) {
569 		OUTP_DBG(outp, "failed to read link status, assuming no sink");
570 		goto done;
571 	}
572 
573 	if (stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE) {
574 		for (i = 0; i < ior->dp.nr; i++) {
575 			u8 lane = (stat[i >> 1] >> ((i & 1) * 4)) & 0x0f;
576 			if (!(lane & DPCD_LS02_LANE0_CR_DONE) ||
577 			    !(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
578 			    !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED)) {
579 				OUTP_DBG(outp, "lane %d not equalised", lane);
580 				goto done;
581 			}
582 		}
583 		retrain = false;
584 	} else {
585 		OUTP_DBG(outp, "no inter-lane alignment");
586 	}
587 
588 done:
589 	if (retrain || !atomic_read(&outp->dp.lt.done))
590 		ret = nvkm_dp_train(outp, dataKBps);
591 	mutex_unlock(&outp->dp.mutex);
592 	return ret;
593 }
594 
595 static bool
596 nvkm_dp_enable_supported_link_rates(struct nvkm_outp *outp)
597 {
598 	u8 sink_rates[DPCD_RC10_SUPPORTED_LINK_RATES__SIZE];
599 	int i, j, k;
600 
601 	if (outp->conn->info.type != DCB_CONNECTOR_eDP ||
602 	    outp->dp.dpcd[DPCD_RC00_DPCD_REV] < 0x13 ||
603 	    nvkm_rdaux(outp->dp.aux, DPCD_RC10_SUPPORTED_LINK_RATES(0),
604 		       sink_rates, sizeof(sink_rates)))
605 		return false;
606 
607 	for (i = 0; i < ARRAY_SIZE(sink_rates); i += 2) {
608 		const u32 rate = ((sink_rates[i + 1] << 8) | sink_rates[i]) * 200 / 10;
609 
610 		if (!rate || WARN_ON(outp->dp.rates == ARRAY_SIZE(outp->dp.rate)))
611 			break;
612 
613 		if (rate > outp->info.dpconf.link_bw * 27000) {
614 			OUTP_DBG(outp, "rate %d !outp", rate);
615 			continue;
616 		}
617 
618 		for (j = 0; j < outp->dp.rates; j++) {
619 			if (rate > outp->dp.rate[j].rate) {
620 				for (k = outp->dp.rates; k > j; k--)
621 					outp->dp.rate[k] = outp->dp.rate[k - 1];
622 				break;
623 			}
624 		}
625 
626 		outp->dp.rate[j].dpcd = i / 2;
627 		outp->dp.rate[j].rate = rate;
628 		outp->dp.rates++;
629 	}
630 
631 	for (i = 0; i < outp->dp.rates; i++)
632 		OUTP_DBG(outp, "link_rate[%d] = %d", outp->dp.rate[i].dpcd, outp->dp.rate[i].rate);
633 
634 	return outp->dp.rates != 0;
635 }
636 
637 void
638 nvkm_dp_enable(struct nvkm_outp *outp, bool auxpwr)
639 {
640 	struct nvkm_gpio *gpio = outp->disp->engine.subdev.device->gpio;
641 	struct nvkm_i2c_aux *aux = outp->dp.aux;
642 
643 	if (auxpwr && !outp->dp.aux_pwr) {
644 		/* eDP panels need powering on by us (if the VBIOS doesn't default it
645 		 * to on) before doing any AUX channel transactions.  LVDS panel power
646 		 * is handled by the SOR itself, and not required for LVDS DDC.
647 		 */
648 		if (outp->conn->info.type == DCB_CONNECTOR_eDP) {
649 			int power = nvkm_gpio_get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);
650 			if (power == 0) {
651 				nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);
652 				outp->dp.aux_pwr_pu = true;
653 			}
654 
655 			/* We delay here unconditionally, even if already powered,
656 			 * because some laptop panels having a significant resume
657 			 * delay before the panel begins responding.
658 			 *
659 			 * This is likely a bit of a hack, but no better idea for
660 			 * handling this at the moment.
661 			 */
662 			msleep(300);
663 		}
664 
665 		OUTP_DBG(outp, "aux power -> always");
666 		nvkm_i2c_aux_monitor(aux, true);
667 		outp->dp.aux_pwr = true;
668 
669 		/* Detect any LTTPRs before reading DPCD receiver caps. */
670 		if (!nvkm_rdaux(aux, DPCD_LTTPR_REV, outp->dp.lttpr, sizeof(outp->dp.lttpr)) &&
671 		    outp->dp.lttpr[0] >= 0x14 && outp->dp.lttpr[2]) {
672 			switch (outp->dp.lttpr[2]) {
673 			case 0x80: outp->dp.lttprs = 1; break;
674 			case 0x40: outp->dp.lttprs = 2; break;
675 			case 0x20: outp->dp.lttprs = 3; break;
676 			case 0x10: outp->dp.lttprs = 4; break;
677 			case 0x08: outp->dp.lttprs = 5; break;
678 			case 0x04: outp->dp.lttprs = 6; break;
679 			case 0x02: outp->dp.lttprs = 7; break;
680 			case 0x01: outp->dp.lttprs = 8; break;
681 			default:
682 				/* Unknown LTTPR count, we'll switch to transparent mode. */
683 				WARN_ON(1);
684 				outp->dp.lttprs = 0;
685 				break;
686 			}
687 		} else {
688 			/* No LTTPR support, or zero LTTPR count - don't touch it at all. */
689 			memset(outp->dp.lttpr, 0x00, sizeof(outp->dp.lttpr));
690 		}
691 
692 		if (!nvkm_rdaux(aux, DPCD_RC00_DPCD_REV, outp->dp.dpcd, sizeof(outp->dp.dpcd))) {
693 			const u8 rates[] = { 0x1e, 0x14, 0x0a, 0x06, 0 };
694 			const u8 *rate;
695 			int rate_max;
696 
697 			outp->dp.rates = 0;
698 			outp->dp.links = outp->dp.dpcd[DPCD_RC02] & DPCD_RC02_MAX_LANE_COUNT;
699 			outp->dp.links = min(outp->dp.links, outp->info.dpconf.link_nr);
700 			if (outp->dp.lttprs && outp->dp.lttpr[4])
701 				outp->dp.links = min_t(int, outp->dp.links, outp->dp.lttpr[4]);
702 
703 			rate_max = outp->dp.dpcd[DPCD_RC01_MAX_LINK_RATE];
704 			rate_max = min(rate_max, outp->info.dpconf.link_bw);
705 			if (outp->dp.lttprs && outp->dp.lttpr[1])
706 				rate_max = min_t(int, rate_max, outp->dp.lttpr[1]);
707 
708 			if (!nvkm_dp_enable_supported_link_rates(outp)) {
709 				for (rate = rates; *rate; rate++) {
710 					if (*rate > rate_max)
711 						continue;
712 
713 					if (WARN_ON(outp->dp.rates == ARRAY_SIZE(outp->dp.rate)))
714 						break;
715 
716 					outp->dp.rate[outp->dp.rates].dpcd = -1;
717 					outp->dp.rate[outp->dp.rates].rate = *rate * 27000;
718 					outp->dp.rates++;
719 				}
720 			}
721 		}
722 	} else
723 	if (!auxpwr && outp->dp.aux_pwr) {
724 		OUTP_DBG(outp, "aux power -> demand");
725 		nvkm_i2c_aux_monitor(aux, false);
726 		outp->dp.aux_pwr = false;
727 		atomic_set(&outp->dp.lt.done, 0);
728 
729 		/* Restore eDP panel GPIO to its prior state if we changed it, as
730 		 * it could potentially interfere with other outputs.
731 		 */
732 		if (outp->conn->info.type == DCB_CONNECTOR_eDP) {
733 			if (outp->dp.aux_pwr_pu) {
734 				nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 0);
735 				outp->dp.aux_pwr_pu = false;
736 			}
737 		}
738 	}
739 }
740 
741 static void
742 nvkm_dp_fini(struct nvkm_outp *outp)
743 {
744 	nvkm_dp_enable(outp, false);
745 }
746 
747 static void
748 nvkm_dp_init(struct nvkm_outp *outp)
749 {
750 	nvkm_dp_enable(outp, outp->dp.enabled);
751 }
752 
753 static void *
754 nvkm_dp_dtor(struct nvkm_outp *outp)
755 {
756 	return outp;
757 }
758 
759 static const struct nvkm_outp_func
760 nvkm_dp_func = {
761 	.dtor = nvkm_dp_dtor,
762 	.init = nvkm_dp_init,
763 	.fini = nvkm_dp_fini,
764 	.acquire = nvkm_dp_acquire,
765 	.release = nvkm_dp_release,
766 	.disable = nvkm_dp_disable,
767 };
768 
769 int
770 nvkm_dp_new(struct nvkm_disp *disp, int index, struct dcb_output *dcbE, struct nvkm_outp **poutp)
771 {
772 	struct nvkm_device *device = disp->engine.subdev.device;
773 	struct nvkm_bios *bios = device->bios;
774 	struct nvkm_i2c *i2c = device->i2c;
775 	struct nvkm_outp *outp;
776 	u8  hdr, cnt, len;
777 	u32 data;
778 	int ret;
779 
780 	ret = nvkm_outp_new_(&nvkm_dp_func, disp, index, dcbE, poutp);
781 	outp = *poutp;
782 	if (ret)
783 		return ret;
784 
785 	if (dcbE->location == 0)
786 		outp->dp.aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_CCB(dcbE->i2c_index));
787 	else
788 		outp->dp.aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_EXT(dcbE->extdev));
789 	if (!outp->dp.aux) {
790 		OUTP_ERR(outp, "no aux");
791 		return -EINVAL;
792 	}
793 
794 	/* bios data is not optional */
795 	data = nvbios_dpout_match(bios, outp->info.hasht, outp->info.hashm,
796 				  &outp->dp.version, &hdr, &cnt, &len, &outp->dp.info);
797 	if (!data) {
798 		OUTP_ERR(outp, "no bios dp data");
799 		return -EINVAL;
800 	}
801 
802 	OUTP_DBG(outp, "bios dp %02x %02x %02x %02x", outp->dp.version, hdr, cnt, len);
803 
804 	mutex_init(&outp->dp.mutex);
805 	atomic_set(&outp->dp.lt.done, 0);
806 	return 0;
807 }
808