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/drmP.h>
26 #include <drm/drm_dp_helper.h>
27 
28 #include "nouveau_drm.h"
29 #include "nouveau_connector.h"
30 #include "nouveau_encoder.h"
31 #include "nouveau_crtc.h"
32 
33 #include <subdev/gpio.h>
34 #include <subdev/i2c.h>
35 
36 u8 *
37 nouveau_dp_bios_data(struct drm_device *dev, struct dcb_output *dcb, u8 **entry)
38 {
39 	struct nouveau_drm *drm = nouveau_drm(dev);
40 	struct bit_entry d;
41 	u8 *table;
42 	int i;
43 
44 	if (bit_table(dev, 'd', &d)) {
45 		NV_ERROR(drm, "BIT 'd' table not found\n");
46 		return NULL;
47 	}
48 
49 	if (d.version != 1) {
50 		NV_ERROR(drm, "BIT 'd' table version %d unknown\n", d.version);
51 		return NULL;
52 	}
53 
54 	table = ROMPTR(dev, d.data[0]);
55 	if (!table) {
56 		NV_ERROR(drm, "displayport table pointer invalid\n");
57 		return NULL;
58 	}
59 
60 	switch (table[0]) {
61 	case 0x20:
62 	case 0x21:
63 	case 0x30:
64 	case 0x40:
65 		break;
66 	default:
67 		NV_ERROR(drm, "displayport table 0x%02x unknown\n", table[0]);
68 		return NULL;
69 	}
70 
71 	for (i = 0; i < table[3]; i++) {
72 		*entry = ROMPTR(dev, table[table[1] + (i * table[2])]);
73 		if (*entry && bios_encoder_match(dcb, ROM32((*entry)[0])))
74 			return table;
75 	}
76 
77 	NV_ERROR(drm, "displayport encoder table not found\n");
78 	return NULL;
79 }
80 
81 /******************************************************************************
82  * link training
83  *****************************************************************************/
84 struct dp_state {
85 	struct nouveau_i2c_port *auxch;
86 	struct dp_train_func *func;
87 	struct dcb_output *dcb;
88 	int crtc;
89 	u8 *dpcd;
90 	int link_nr;
91 	u32 link_bw;
92 	u8  stat[6];
93 	u8  conf[4];
94 };
95 
96 static void
97 dp_set_link_config(struct drm_device *dev, struct dp_state *dp)
98 {
99 	struct nouveau_drm *drm = nouveau_drm(dev);
100 	u8 sink[2];
101 
102 	NV_DEBUG(drm, "%d lanes at %d KB/s\n", dp->link_nr, dp->link_bw);
103 
104 	/* set desired link configuration on the source */
105 	dp->func->link_set(dev, dp->dcb, dp->crtc, dp->link_nr, dp->link_bw,
106 			   dp->dpcd[2] & DP_ENHANCED_FRAME_CAP);
107 
108 	/* inform the sink of the new configuration */
109 	sink[0] = dp->link_bw / 27000;
110 	sink[1] = dp->link_nr;
111 	if (dp->dpcd[2] & DP_ENHANCED_FRAME_CAP)
112 		sink[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
113 
114 	nv_wraux(dp->auxch, DP_LINK_BW_SET, sink, 2);
115 }
116 
117 static void
118 dp_set_training_pattern(struct drm_device *dev, struct dp_state *dp, u8 pattern)
119 {
120 	struct nouveau_drm *drm = nouveau_drm(dev);
121 	u8 sink_tp;
122 
123 	NV_DEBUG(drm, "training pattern %d\n", pattern);
124 
125 	dp->func->train_set(dev, dp->dcb, pattern);
126 
127 	nv_rdaux(dp->auxch, DP_TRAINING_PATTERN_SET, &sink_tp, 1);
128 	sink_tp &= ~DP_TRAINING_PATTERN_MASK;
129 	sink_tp |= pattern;
130 	nv_wraux(dp->auxch, DP_TRAINING_PATTERN_SET, &sink_tp, 1);
131 }
132 
133 static int
134 dp_link_train_commit(struct drm_device *dev, struct dp_state *dp)
135 {
136 	struct nouveau_drm *drm = nouveau_drm(dev);
137 	int i;
138 
139 	for (i = 0; i < dp->link_nr; i++) {
140 		u8 lane = (dp->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
141 		u8 lpre = (lane & 0x0c) >> 2;
142 		u8 lvsw = (lane & 0x03) >> 0;
143 
144 		dp->conf[i] = (lpre << 3) | lvsw;
145 		if (lvsw == DP_TRAIN_VOLTAGE_SWING_1200)
146 			dp->conf[i] |= DP_TRAIN_MAX_SWING_REACHED;
147 		if ((lpre << 3) == DP_TRAIN_PRE_EMPHASIS_9_5)
148 			dp->conf[i] |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
149 
150 		NV_DEBUG(drm, "config lane %d %02x\n", i, dp->conf[i]);
151 		dp->func->train_adj(dev, dp->dcb, i, lvsw, lpre);
152 	}
153 
154 	return nv_wraux(dp->auxch, DP_TRAINING_LANE0_SET, dp->conf, 4);
155 }
156 
157 static int
158 dp_link_train_update(struct drm_device *dev, struct dp_state *dp, u32 delay)
159 {
160 	struct nouveau_drm *drm = nouveau_drm(dev);
161 	int ret;
162 
163 	udelay(delay);
164 
165 	ret = nv_rdaux(dp->auxch, DP_LANE0_1_STATUS, dp->stat, 6);
166 	if (ret)
167 		return ret;
168 
169 	NV_DEBUG(drm, "status %*ph\n", 6, dp->stat);
170 	return 0;
171 }
172 
173 static int
174 dp_link_train_cr(struct drm_device *dev, struct dp_state *dp)
175 {
176 	bool cr_done = false, abort = false;
177 	int voltage = dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
178 	int tries = 0, i;
179 
180 	dp_set_training_pattern(dev, dp, DP_TRAINING_PATTERN_1);
181 
182 	do {
183 		if (dp_link_train_commit(dev, dp) ||
184 		    dp_link_train_update(dev, dp, 100))
185 			break;
186 
187 		cr_done = true;
188 		for (i = 0; i < dp->link_nr; i++) {
189 			u8 lane = (dp->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
190 			if (!(lane & DP_LANE_CR_DONE)) {
191 				cr_done = false;
192 				if (dp->conf[i] & DP_TRAIN_MAX_SWING_REACHED)
193 					abort = true;
194 				break;
195 			}
196 		}
197 
198 		if ((dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK) != voltage) {
199 			voltage = dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
200 			tries = 0;
201 		}
202 	} while (!cr_done && !abort && ++tries < 5);
203 
204 	return cr_done ? 0 : -1;
205 }
206 
207 static int
208 dp_link_train_eq(struct drm_device *dev, struct dp_state *dp)
209 {
210 	bool eq_done, cr_done = true;
211 	int tries = 0, i;
212 
213 	dp_set_training_pattern(dev, dp, DP_TRAINING_PATTERN_2);
214 
215 	do {
216 		if (dp_link_train_update(dev, dp, 400))
217 			break;
218 
219 		eq_done = !!(dp->stat[2] & DP_INTERLANE_ALIGN_DONE);
220 		for (i = 0; i < dp->link_nr && eq_done; i++) {
221 			u8 lane = (dp->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
222 			if (!(lane & DP_LANE_CR_DONE))
223 				cr_done = false;
224 			if (!(lane & DP_LANE_CHANNEL_EQ_DONE) ||
225 			    !(lane & DP_LANE_SYMBOL_LOCKED))
226 				eq_done = false;
227 		}
228 
229 		if (dp_link_train_commit(dev, dp))
230 			break;
231 	} while (!eq_done && cr_done && ++tries <= 5);
232 
233 	return eq_done ? 0 : -1;
234 }
235 
236 static void
237 dp_set_downspread(struct drm_device *dev, struct dp_state *dp, bool enable)
238 {
239 	u16 script = 0x0000;
240 	u8 *entry, *table = nouveau_dp_bios_data(dev, dp->dcb, &entry);
241 	if (table) {
242 		if (table[0] >= 0x20 && table[0] <= 0x30) {
243 			if (enable) script = ROM16(entry[12]);
244 			else        script = ROM16(entry[14]);
245 		} else
246 		if (table[0] == 0x40) {
247 			if (enable) script = ROM16(entry[11]);
248 			else        script = ROM16(entry[13]);
249 		}
250 	}
251 
252 	nouveau_bios_run_init_table(dev, script, dp->dcb, dp->crtc);
253 }
254 
255 static void
256 dp_link_train_init(struct drm_device *dev, struct dp_state *dp)
257 {
258 	u16 script = 0x0000;
259 	u8 *entry, *table = nouveau_dp_bios_data(dev, dp->dcb, &entry);
260 	if (table) {
261 		if (table[0] >= 0x20 && table[0] <= 0x30)
262 			script = ROM16(entry[6]);
263 		else
264 		if (table[0] == 0x40)
265 			script = ROM16(entry[5]);
266 	}
267 
268 	nouveau_bios_run_init_table(dev, script, dp->dcb, dp->crtc);
269 }
270 
271 static void
272 dp_link_train_fini(struct drm_device *dev, struct dp_state *dp)
273 {
274 	u16 script = 0x0000;
275 	u8 *entry, *table = nouveau_dp_bios_data(dev, dp->dcb, &entry);
276 	if (table) {
277 		if (table[0] >= 0x20 && table[0] <= 0x30)
278 			script = ROM16(entry[8]);
279 		else
280 		if (table[0] == 0x40)
281 			script = ROM16(entry[7]);
282 	}
283 
284 	nouveau_bios_run_init_table(dev, script, dp->dcb, dp->crtc);
285 }
286 
287 static bool
288 nouveau_dp_link_train(struct drm_encoder *encoder, u32 datarate,
289 		      struct dp_train_func *func)
290 {
291 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
292 	struct nouveau_crtc *nv_crtc = nouveau_crtc(encoder->crtc);
293 	struct nouveau_connector *nv_connector =
294 		nouveau_encoder_connector_get(nv_encoder);
295 	struct drm_device *dev = encoder->dev;
296 	struct nouveau_drm *drm = nouveau_drm(dev);
297 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
298 	struct nouveau_gpio *gpio = nouveau_gpio(drm->device);
299 	const u32 bw_list[] = { 270000, 162000, 0 };
300 	const u32 *link_bw = bw_list;
301 	struct dp_state dp;
302 
303 	dp.auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
304 	if (!dp.auxch)
305 		return false;
306 
307 	dp.func = func;
308 	dp.dcb = nv_encoder->dcb;
309 	dp.crtc = nv_crtc->index;
310 	dp.dpcd = nv_encoder->dp.dpcd;
311 
312 	/* adjust required bandwidth for 8B/10B coding overhead */
313 	datarate = (datarate / 8) * 10;
314 
315 	/* some sinks toggle hotplug in response to some of the actions
316 	 * we take during link training (DP_SET_POWER is one), we need
317 	 * to ignore them for the moment to avoid races.
318 	 */
319 	gpio->irq(gpio, 0, nv_connector->hpd, 0xff, false);
320 
321 	/* enable down-spreading, if possible */
322 	dp_set_downspread(dev, &dp, nv_encoder->dp.dpcd[3] & 1);
323 
324 	/* execute pre-train script from vbios */
325 	dp_link_train_init(dev, &dp);
326 
327 	/* start off at highest link rate supported by encoder and display */
328 	while (*link_bw > nv_encoder->dp.link_bw)
329 		link_bw++;
330 
331 	while (link_bw[0]) {
332 		/* find minimum required lane count at this link rate */
333 		dp.link_nr = nv_encoder->dp.link_nr;
334 		while ((dp.link_nr >> 1) * link_bw[0] > datarate)
335 			dp.link_nr >>= 1;
336 
337 		/* drop link rate to minimum with this lane count */
338 		while ((link_bw[1] * dp.link_nr) > datarate)
339 			link_bw++;
340 		dp.link_bw = link_bw[0];
341 
342 		/* program selected link configuration */
343 		dp_set_link_config(dev, &dp);
344 
345 		/* attempt to train the link at this configuration */
346 		memset(dp.stat, 0x00, sizeof(dp.stat));
347 		if (!dp_link_train_cr(dev, &dp) &&
348 		    !dp_link_train_eq(dev, &dp))
349 			break;
350 
351 		/* retry at lower rate */
352 		link_bw++;
353 	}
354 
355 	/* finish link training */
356 	dp_set_training_pattern(dev, &dp, DP_TRAINING_PATTERN_DISABLE);
357 
358 	/* execute post-train script from vbios */
359 	dp_link_train_fini(dev, &dp);
360 
361 	/* re-enable hotplug detect */
362 	gpio->irq(gpio, 0, nv_connector->hpd, 0xff, true);
363 	return true;
364 }
365 
366 void
367 nouveau_dp_dpms(struct drm_encoder *encoder, int mode, u32 datarate,
368 		struct dp_train_func *func)
369 {
370 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
371 	struct nouveau_drm *drm = nouveau_drm(encoder->dev);
372 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
373 	struct nouveau_i2c_port *auxch;
374 	u8 status;
375 
376 	auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
377 	if (!auxch)
378 		return;
379 
380 	if (mode == DRM_MODE_DPMS_ON)
381 		status = DP_SET_POWER_D0;
382 	else
383 		status = DP_SET_POWER_D3;
384 
385 	nv_wraux(auxch, DP_SET_POWER, &status, 1);
386 
387 	if (mode == DRM_MODE_DPMS_ON)
388 		nouveau_dp_link_train(encoder, datarate, func);
389 }
390 
391 static void
392 nouveau_dp_probe_oui(struct drm_device *dev, struct nouveau_i2c_port *auxch,
393 		     u8 *dpcd)
394 {
395 	struct nouveau_drm *drm = nouveau_drm(dev);
396 	u8 buf[3];
397 
398 	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
399 		return;
400 
401 	if (!nv_rdaux(auxch, DP_SINK_OUI, buf, 3))
402 		NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
403 			     buf[0], buf[1], buf[2]);
404 
405 	if (!nv_rdaux(auxch, DP_BRANCH_OUI, buf, 3))
406 		NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
407 			     buf[0], buf[1], buf[2]);
408 
409 }
410 
411 bool
412 nouveau_dp_detect(struct drm_encoder *encoder)
413 {
414 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
415 	struct drm_device *dev = encoder->dev;
416 	struct nouveau_drm *drm = nouveau_drm(dev);
417 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
418 	struct nouveau_i2c_port *auxch;
419 	u8 *dpcd = nv_encoder->dp.dpcd;
420 	int ret;
421 
422 	auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
423 	if (!auxch)
424 		return false;
425 
426 	ret = nv_rdaux(auxch, DP_DPCD_REV, dpcd, 8);
427 	if (ret)
428 		return false;
429 
430 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
431 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
432 
433 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
434 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
435 	NV_DEBUG(drm, "encoder: %dx%d\n",
436 		     nv_encoder->dcb->dpconf.link_nr,
437 		     nv_encoder->dcb->dpconf.link_bw);
438 
439 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
440 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
441 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
442 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
443 
444 	NV_DEBUG(drm, "maximum: %dx%d\n",
445 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
446 
447 	nouveau_dp_probe_oui(dev, auxch, dpcd);
448 
449 	return true;
450 }
451