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
34MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
35static int nouveau_mst = 1;
36module_param_named(mst, nouveau_mst, int, 0400);
37
38static bool
39nouveau_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
45static bool
46nouveau_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
60static enum drm_connector_status
61nouveau_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);
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;
208out:
209	if (status != connector_status_connected) {
210		/* Clear any cached info */
211		outp->dp.sink_count = 0;
212	}
213	return status;
214}
215
216int
217nouveau_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
298out:
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
313void
314nouveau_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
333static bool
334nouveau_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
344retry:
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
417bool
418nouveau_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;
457done:
458	mutex_unlock(&outp->dp.hpd_irq_lock);
459	return ret;
460}
461
462static bool
463nouveau_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
479bool
480nouveau_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
495void
496nouveau_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 */
539enum drm_mode_status
540nv50_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