xref: /linux/drivers/gpu/drm/nouveau/nouveau_dp.c (revision db5d28c0bfe566908719bec8e25443aabecbb802)
1 /*
2  * Copyright 2009 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 
25 #include <drm/display/drm_dp_helper.h>
26 
27 #include "nouveau_drv.h"
28 #include "nouveau_connector.h"
29 #include "nouveau_encoder.h"
30 #include "nouveau_crtc.h"
31 
32 #include <nvif/if0011.h>
33 
34 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
35 static int nouveau_mst = 1;
36 module_param_named(mst, nouveau_mst, int, 0400);
37 
38 static bool
nouveau_dp_has_sink_count(struct drm_connector * connector,struct nouveau_encoder * outp)39 nouveau_dp_has_sink_count(struct drm_connector *connector,
40 			  struct nouveau_encoder *outp)
41 {
42 	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
43 }
44 
45 static bool
nouveau_dp_probe_lttpr(struct nouveau_encoder * outp)46 nouveau_dp_probe_lttpr(struct nouveau_encoder *outp)
47 {
48 	u8 rev, size = sizeof(rev);
49 	int ret;
50 
51 	ret = nvif_outp_dp_aux_xfer(&outp->outp, DP_AUX_NATIVE_READ, &size,
52 				    DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV,
53 				    &rev);
54 	if (ret || size < sizeof(rev) || rev < 0x14)
55 		return false;
56 
57 	return true;
58 }
59 
60 static enum drm_connector_status
nouveau_dp_probe_dpcd(struct nouveau_connector * nv_connector,struct nouveau_encoder * outp)61 nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
62 		      struct nouveau_encoder *outp)
63 {
64 	struct drm_connector *connector = &nv_connector->base;
65 	struct drm_dp_aux *aux = &nv_connector->aux;
66 	struct nv50_mstm *mstm = NULL;
67 	enum drm_connector_status status = connector_status_disconnected;
68 	int ret;
69 	u8 *dpcd = outp->dp.dpcd;
70 
71 	outp->dp.lttpr.nr = 0;
72 	outp->dp.rate_nr  = 0;
73 	outp->dp.link_nr  = 0;
74 	outp->dp.link_bw  = 0;
75 
76 	if (connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
77 	    nouveau_dp_probe_lttpr(outp) &&
78 	    !drm_dp_read_dpcd_caps(aux, dpcd) &&
79 	    !drm_dp_read_lttpr_common_caps(aux, dpcd, outp->dp.lttpr.caps)) {
80 		int nr = drm_dp_lttpr_count(outp->dp.lttpr.caps);
81 
82 		if (nr) {
83 			drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE,
84 						DP_PHY_REPEATER_MODE_TRANSPARENT);
85 
86 			if (nr > 0) {
87 				ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE,
88 							      DP_PHY_REPEATER_MODE_NON_TRANSPARENT);
89 				if (ret != 1) {
90 					drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE,
91 								DP_PHY_REPEATER_MODE_TRANSPARENT);
92 				} else {
93 					outp->dp.lttpr.nr = nr;
94 				}
95 			}
96 		}
97 	}
98 
99 	ret = drm_dp_read_dpcd_caps(aux, dpcd);
100 	if (ret < 0)
101 		goto out;
102 
103 	outp->dp.link_nr = dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
104 	if (outp->dcb->dpconf.link_nr < outp->dp.link_nr)
105 		outp->dp.link_nr = outp->dcb->dpconf.link_nr;
106 
107 	if (outp->dp.lttpr.nr) {
108 		int links = drm_dp_lttpr_max_lane_count(outp->dp.lttpr.caps);
109 
110 		if (links && links < outp->dp.link_nr)
111 			outp->dp.link_nr = links;
112 	}
113 
114 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP && dpcd[DP_DPCD_REV] >= 0x13) {
115 		__le16 rates[DP_MAX_SUPPORTED_RATES];
116 
117 		ret = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES, rates, sizeof(rates));
118 		if (ret == sizeof(rates)) {
119 			for (int i = 0; i < ARRAY_SIZE(rates); i++) {
120 				u32 rate = (le16_to_cpu(rates[i]) * 200) / 10;
121 				int j;
122 
123 				if (!rate)
124 					break;
125 
126 				for (j = 0; j < outp->dp.rate_nr; j++) {
127 					if (rate > outp->dp.rate[j].rate) {
128 						for (int k = outp->dp.rate_nr; k > j; k--)
129 							outp->dp.rate[k] = outp->dp.rate[k - 1];
130 						break;
131 					}
132 				}
133 
134 				outp->dp.rate[j].dpcd = i;
135 				outp->dp.rate[j].rate = rate;
136 				outp->dp.rate_nr++;
137 			}
138 		}
139 	}
140 
141 	if (!outp->dp.rate_nr) {
142 		const u32 rates[] = { 810000, 540000, 270000, 162000 };
143 		u32 max_rate = dpcd[DP_MAX_LINK_RATE] * 27000;
144 
145 		if (outp->dp.lttpr.nr) {
146 			int rate = drm_dp_lttpr_max_link_rate(outp->dp.lttpr.caps);
147 
148 			if (rate && rate < max_rate)
149 				max_rate = rate;
150 		}
151 
152 		max_rate = min_t(int, max_rate, outp->dcb->dpconf.link_bw);
153 
154 		for (int i = 0; i < ARRAY_SIZE(rates); i++) {
155 			if (rates[i] <= max_rate) {
156 				outp->dp.rate[outp->dp.rate_nr].dpcd = -1;
157 				outp->dp.rate[outp->dp.rate_nr].rate = rates[i];
158 				outp->dp.rate_nr++;
159 			}
160 		}
161 
162 		if (WARN_ON(!outp->dp.rate_nr))
163 			goto out;
164 	}
165 
166 	ret = nvif_outp_dp_rates(&outp->outp, outp->dp.rate, outp->dp.rate_nr);
167 	if (ret)
168 		goto out;
169 
170 	for (int i = 0; i < outp->dp.rate_nr; i++) {
171 		u32 link_bw = outp->dp.rate[i].rate;
172 
173 		if (link_bw > outp->dp.link_bw)
174 			outp->dp.link_bw = link_bw;
175 	}
176 
177 	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
178 	if (ret < 0)
179 		goto out;
180 
181 	if (nouveau_mst) {
182 		mstm = outp->dp.mstm;
183 		if (mstm)
184 			mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd) == DRM_DP_MST;
185 	}
186 
187 	if (nouveau_dp_has_sink_count(connector, outp)) {
188 		ret = drm_dp_read_sink_count(aux);
189 		if (ret < 0)
190 			goto out;
191 
192 		outp->dp.sink_count = ret;
193 
194 		/*
195 		 * Dongle connected, but no display. Don't bother reading
196 		 * downstream port info
197 		 */
198 		if (!outp->dp.sink_count)
199 			return connector_status_disconnected;
200 	}
201 
202 	ret = drm_dp_read_downstream_info(aux, dpcd,
203 					  outp->dp.downstream_ports);
204 	if (ret < 0)
205 		goto out;
206 
207 	status = connector_status_connected;
208 out:
209 	if (status != connector_status_connected) {
210 		/* Clear any cached info */
211 		outp->dp.sink_count = 0;
212 	}
213 	return status;
214 }
215 
216 int
nouveau_dp_detect(struct nouveau_connector * nv_connector,struct nouveau_encoder * nv_encoder)217 nouveau_dp_detect(struct nouveau_connector *nv_connector,
218 		  struct nouveau_encoder *nv_encoder)
219 {
220 	struct drm_device *dev = nv_encoder->base.base.dev;
221 	struct nouveau_drm *drm = nouveau_drm(dev);
222 	struct drm_connector *connector = &nv_connector->base;
223 	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
224 	enum drm_connector_status status;
225 	u8 *dpcd = nv_encoder->dp.dpcd;
226 	int ret = NOUVEAU_DP_NONE, hpd;
227 
228 	/* eDP ports don't support hotplugging - so there's no point in probing eDP ports unless we
229 	 * haven't probed them once before.
230 	 */
231 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
232 		if (connector->status == connector_status_connected)
233 			return NOUVEAU_DP_SST;
234 		else if (connector->status == connector_status_disconnected)
235 			return NOUVEAU_DP_NONE;
236 	}
237 
238 	// Ensure that the aux bus is enabled for probing
239 	drm_dp_dpcd_set_powered(&nv_connector->aux, true);
240 
241 	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
242 	if (mstm) {
243 		/* If we're not ready to handle MST state changes yet, just
244 		 * report the last status of the connector. We'll reprobe it
245 		 * once we've resumed.
246 		 */
247 		if (mstm->suspended) {
248 			if (mstm->is_mst)
249 				ret = NOUVEAU_DP_MST;
250 			else if (connector->status ==
251 				 connector_status_connected)
252 				ret = NOUVEAU_DP_SST;
253 
254 			goto out;
255 		}
256 	}
257 
258 	hpd = nvif_outp_detect(&nv_encoder->outp);
259 	if (hpd == NOT_PRESENT) {
260 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
261 		goto out;
262 	}
263 	nvif_outp_dp_aux_pwr(&nv_encoder->outp, true);
264 
265 	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
266 	if (status == connector_status_disconnected) {
267 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
268 		goto out;
269 	}
270 
271 	/* If we're in MST mode, we're done here */
272 	if (mstm && mstm->can_mst && mstm->is_mst) {
273 		ret = NOUVEAU_DP_MST;
274 		goto out;
275 	}
276 
277 	NV_DEBUG(drm, "sink dpcd version: 0x%02x\n", dpcd[DP_DPCD_REV]);
278 	for (int i = 0; i < nv_encoder->dp.rate_nr; i++)
279 		NV_DEBUG(drm, "sink rate %d: %d\n", i, nv_encoder->dp.rate[i].rate);
280 
281 	NV_DEBUG(drm, "encoder: %dx%d\n", nv_encoder->dcb->dpconf.link_nr,
282 					  nv_encoder->dcb->dpconf.link_bw);
283 	NV_DEBUG(drm, "maximum: %dx%d\n", nv_encoder->dp.link_nr,
284 					  nv_encoder->dp.link_bw);
285 
286 	if (mstm && mstm->can_mst) {
287 		ret = nv50_mstm_detect(nv_encoder);
288 		if (ret == 1) {
289 			ret = NOUVEAU_DP_MST;
290 			goto out;
291 		} else if (ret != 0) {
292 			nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
293 			goto out;
294 		}
295 	}
296 	ret = NOUVEAU_DP_SST;
297 
298 out:
299 	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
300 		nv50_mstm_remove(mstm);
301 
302 	/* GSP doesn't like when we try to do aux transactions on a port it considers disconnected,
303 	 * and since we don't really have a usecase for that anyway - just disable the aux bus here
304 	 * if we've decided the connector is disconnected
305 	 */
306 	if (ret == NOUVEAU_DP_NONE)
307 		drm_dp_dpcd_set_powered(&nv_connector->aux, false);
308 
309 	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
310 	return ret;
311 }
312 
313 void
nouveau_dp_power_down(struct nouveau_encoder * outp)314 nouveau_dp_power_down(struct nouveau_encoder *outp)
315 {
316 	struct drm_dp_aux *aux = &outp->conn->aux;
317 	int ret;
318 	u8 pwr;
319 
320 	mutex_lock(&outp->dp.hpd_irq_lock);
321 
322 	ret = drm_dp_dpcd_readb(aux, DP_SET_POWER, &pwr);
323 	if (ret == 1) {
324 		pwr &= ~DP_SET_POWER_MASK;
325 		pwr |=  DP_SET_POWER_D3;
326 		drm_dp_dpcd_writeb(aux, DP_SET_POWER, pwr);
327 	}
328 
329 	outp->dp.lt.nr = 0;
330 	mutex_unlock(&outp->dp.hpd_irq_lock);
331 }
332 
333 static bool
nouveau_dp_train_link(struct nouveau_encoder * outp,bool retrain)334 nouveau_dp_train_link(struct nouveau_encoder *outp, bool retrain)
335 {
336 	struct drm_dp_aux *aux = &outp->conn->aux;
337 	bool post_lt = false;
338 	int ret, retries = 0;
339 
340 	if ( (outp->dp.dpcd[DP_MAX_LANE_COUNT] & 0x20) &&
341 	    !(outp->dp.dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED))
342 	    post_lt = true;
343 
344 retry:
345 	ret = nvif_outp_dp_train(&outp->outp, outp->dp.dpcd,
346 					      outp->dp.lttpr.nr,
347 					      outp->dp.lt.nr,
348 					      outp->dp.lt.bw,
349 					      outp->dp.lt.mst,
350 					      post_lt,
351 					      retrain);
352 	if (ret)
353 		return false;
354 
355 	if (post_lt) {
356 		u8 stat[DP_LINK_STATUS_SIZE];
357 		u8 prev[2];
358 		u8 time = 0, adjusts = 0, tmp;
359 
360 		ret = drm_dp_dpcd_read_phy_link_status(aux, DP_PHY_DPRX, stat);
361 		if (ret)
362 			return false;
363 
364 		for (;;) {
365 			if (!drm_dp_channel_eq_ok(stat, outp->dp.lt.nr)) {
366 				ret = 1;
367 				break;
368 			}
369 
370 			if (!(stat[2] & 0x02))
371 				break;
372 
373 			msleep(5);
374 			time += 5;
375 
376 			memcpy(prev, &stat[4], sizeof(prev));
377 			ret = drm_dp_dpcd_read_phy_link_status(aux, DP_PHY_DPRX, stat);
378 			if (ret)
379 				break;
380 
381 			if (!memcmp(prev, &stat[4], sizeof(prev))) {
382 				if (time > 200)
383 					break;
384 			} else {
385 				u8 pe[4], vs[4];
386 
387 				if (adjusts++ == 6)
388 					break;
389 
390 				for (int i = 0; i < outp->dp.lt.nr; i++) {
391 					pe[i] = drm_dp_get_adjust_request_pre_emphasis(stat, i) >>
392 							DP_TRAIN_PRE_EMPHASIS_SHIFT;
393 					vs[i] = drm_dp_get_adjust_request_voltage(stat, i) >>
394 							DP_TRAIN_VOLTAGE_SWING_SHIFT;
395 				}
396 
397 				ret = nvif_outp_dp_drive(&outp->outp, outp->dp.lt.nr, pe, vs);
398 				if (ret)
399 					break;
400 
401 				time = 0;
402 			}
403 		}
404 
405 		if (drm_dp_dpcd_readb(aux, DP_LANE_COUNT_SET, &tmp) == 1) {
406 			tmp &= ~0x20;
407 			drm_dp_dpcd_writeb(aux, DP_LANE_COUNT_SET, tmp);
408 		}
409 	}
410 
411 	if (ret == 1 && retries++ < 3)
412 		goto retry;
413 
414 	return ret == 0;
415 }
416 
417 bool
nouveau_dp_train(struct nouveau_encoder * outp,bool mst,u32 khz,u8 bpc)418 nouveau_dp_train(struct nouveau_encoder *outp, bool mst, u32 khz, u8 bpc)
419 {
420 	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
421 	struct drm_dp_aux *aux = &outp->conn->aux;
422 	u32 min_rate;
423 	u8 pwr;
424 	bool ret = true;
425 
426 	if (mst)
427 		min_rate = outp->dp.link_nr * outp->dp.rate[0].rate;
428 	else
429 		min_rate = DIV_ROUND_UP(khz * bpc * 3, 8);
430 
431 	NV_DEBUG(drm, "%s link training (mst:%d min_rate:%d)\n",
432 		 outp->base.base.name, mst, min_rate);
433 
434 	mutex_lock(&outp->dp.hpd_irq_lock);
435 
436 	if (drm_dp_dpcd_readb(aux, DP_SET_POWER, &pwr) == 1) {
437 		if ((pwr & DP_SET_POWER_MASK) != DP_SET_POWER_D0) {
438 			pwr &= ~DP_SET_POWER_MASK;
439 			pwr |=  DP_SET_POWER_D0;
440 			drm_dp_dpcd_writeb(aux, DP_SET_POWER, pwr);
441 		}
442 	}
443 
444 	for (int nr = outp->dp.link_nr; nr; nr >>= 1) {
445 		for (int rate = 0; rate < outp->dp.rate_nr; rate++) {
446 			if (outp->dp.rate[rate].rate * nr >= min_rate) {
447 				outp->dp.lt.nr = nr;
448 				outp->dp.lt.bw = outp->dp.rate[rate].rate;
449 				outp->dp.lt.mst = mst;
450 				if (nouveau_dp_train_link(outp, false))
451 					goto done;
452 			}
453 		}
454 	}
455 
456 	ret = false;
457 done:
458 	mutex_unlock(&outp->dp.hpd_irq_lock);
459 	return ret;
460 }
461 
462 static bool
nouveau_dp_link_check_locked(struct nouveau_encoder * outp)463 nouveau_dp_link_check_locked(struct nouveau_encoder *outp)
464 {
465 	u8 link_status[DP_LINK_STATUS_SIZE];
466 
467 	if (!outp || !outp->dp.lt.nr)
468 		return true;
469 
470 	if (drm_dp_dpcd_read_phy_link_status(&outp->conn->aux, DP_PHY_DPRX, link_status) < 0)
471 		return false;
472 
473 	if (drm_dp_channel_eq_ok(link_status, outp->dp.lt.nr))
474 		return true;
475 
476 	return nouveau_dp_train_link(outp, true);
477 }
478 
479 bool
nouveau_dp_link_check(struct nouveau_connector * nv_connector)480 nouveau_dp_link_check(struct nouveau_connector *nv_connector)
481 {
482 	struct nouveau_encoder *outp = nv_connector->dp_encoder;
483 	bool link_ok = true;
484 
485 	if (outp) {
486 		mutex_lock(&outp->dp.hpd_irq_lock);
487 		if (outp->dp.lt.nr)
488 			link_ok = nouveau_dp_link_check_locked(outp);
489 		mutex_unlock(&outp->dp.hpd_irq_lock);
490 	}
491 
492 	return link_ok;
493 }
494 
495 void
nouveau_dp_irq(struct work_struct * work)496 nouveau_dp_irq(struct work_struct *work)
497 {
498 	struct nouveau_connector *nv_connector =
499 		container_of(work, typeof(*nv_connector), irq_work);
500 	struct drm_connector *connector = &nv_connector->base;
501 	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
502 	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
503 	struct nv50_mstm *mstm;
504 	u64 hpd = 0;
505 	int ret;
506 
507 	if (!outp)
508 		return;
509 
510 	mstm = outp->dp.mstm;
511 	NV_DEBUG(drm, "service %s\n", connector->name);
512 
513 	mutex_lock(&outp->dp.hpd_irq_lock);
514 
515 	if (mstm && mstm->is_mst) {
516 		if (!nv50_mstm_service(drm, nv_connector, mstm))
517 			hpd |= NVIF_CONN_EVENT_V0_UNPLUG;
518 	} else {
519 		drm_dp_cec_irq(&nv_connector->aux);
520 
521 		if (nouveau_dp_has_sink_count(connector, outp)) {
522 			ret = drm_dp_read_sink_count(&nv_connector->aux);
523 			if (ret != outp->dp.sink_count)
524 				hpd |= NVIF_CONN_EVENT_V0_PLUG;
525 			if (ret >= 0)
526 				outp->dp.sink_count = ret;
527 		}
528 	}
529 
530 	mutex_unlock(&outp->dp.hpd_irq_lock);
531 
532 	nouveau_connector_hpd(nv_connector, NVIF_CONN_EVENT_V0_IRQ | hpd);
533 }
534 
535 /* TODO:
536  * - Validate against the DP caps advertised by the GPU (we don't check these
537  *   yet)
538  */
539 enum drm_mode_status
nv50_dp_mode_valid(struct nouveau_encoder * outp,const struct drm_display_mode * mode,unsigned * out_clock)540 nv50_dp_mode_valid(struct nouveau_encoder *outp,
541 		   const struct drm_display_mode *mode,
542 		   unsigned *out_clock)
543 {
544 	const unsigned int min_clock = 25000;
545 	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
546 	/* Check with the minmum bpc always, so we can advertise better modes.
547 	 * In particlar not doing this causes modes to be dropped on HDR
548 	 * displays as we might check with a bpc of 16 even.
549 	 */
550 	const u8 bpp = 6 * 3;
551 
552 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
553 		return MODE_NO_INTERLACE;
554 
555 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
556 		clock *= 2;
557 
558 	max_rate = outp->dp.link_nr * outp->dp.link_bw;
559 	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
560 	if (mode_rate > max_rate)
561 		return MODE_CLOCK_HIGH;
562 
563 	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
564 	if (ds_max_dotclock && clock > ds_max_dotclock)
565 		return MODE_CLOCK_HIGH;
566 
567 	if (clock < min_clock)
568 		return MODE_CLOCK_LOW;
569 
570 	if (out_clock)
571 		*out_clock = clock;
572 
573 	return MODE_OK;
574 }
575