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 <core/class.h>
34 
35 #include <subdev/gpio.h>
36 #include <subdev/i2c.h>
37 
38 /******************************************************************************
39  * link training
40  *****************************************************************************/
41 struct dp_state {
42 	struct nouveau_i2c_port *auxch;
43 	struct nouveau_object *core;
44 	struct dcb_output *dcb;
45 	int crtc;
46 	u8 *dpcd;
47 	int link_nr;
48 	u32 link_bw;
49 	u8  stat[6];
50 	u8  conf[4];
51 };
52 
53 static void
54 dp_set_link_config(struct drm_device *dev, struct dp_state *dp)
55 {
56 	struct nouveau_drm *drm = nouveau_drm(dev);
57 	struct dcb_output *dcb = dp->dcb;
58 	const u32 or = ffs(dcb->or) - 1, link = !(dcb->sorconf.link & 1);
59 	const u32 moff = (dp->crtc << 3) | (link << 2) | or;
60 	u8 sink[2];
61 	u32 data;
62 
63 	NV_DEBUG(drm, "%d lanes at %d KB/s\n", dp->link_nr, dp->link_bw);
64 
65 	/* set desired link configuration on the source */
66 	data = ((dp->link_bw / 27000) << 8) | dp->link_nr;
67 	if (dp->dpcd[2] & DP_ENHANCED_FRAME_CAP)
68 		data |= NV94_DISP_SOR_DP_LNKCTL_FRAME_ENH;
69 
70 	nv_call(dp->core, NV94_DISP_SOR_DP_LNKCTL + moff, data);
71 
72 	/* inform the sink of the new configuration */
73 	sink[0] = dp->link_bw / 27000;
74 	sink[1] = dp->link_nr;
75 	if (dp->dpcd[2] & DP_ENHANCED_FRAME_CAP)
76 		sink[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
77 
78 	nv_wraux(dp->auxch, DP_LINK_BW_SET, sink, 2);
79 }
80 
81 static void
82 dp_set_training_pattern(struct drm_device *dev, struct dp_state *dp, u8 pattern)
83 {
84 	struct nouveau_drm *drm = nouveau_drm(dev);
85 	struct dcb_output *dcb = dp->dcb;
86 	const u32 or = ffs(dcb->or) - 1, link = !(dcb->sorconf.link & 1);
87 	const u32 moff = (dp->crtc << 3) | (link << 2) | or;
88 	u8 sink_tp;
89 
90 	NV_DEBUG(drm, "training pattern %d\n", pattern);
91 
92 	nv_call(dp->core, NV94_DISP_SOR_DP_TRAIN + moff, pattern);
93 
94 	nv_rdaux(dp->auxch, DP_TRAINING_PATTERN_SET, &sink_tp, 1);
95 	sink_tp &= ~DP_TRAINING_PATTERN_MASK;
96 	sink_tp |= pattern;
97 	nv_wraux(dp->auxch, DP_TRAINING_PATTERN_SET, &sink_tp, 1);
98 }
99 
100 static int
101 dp_link_train_commit(struct drm_device *dev, struct dp_state *dp)
102 {
103 	struct nouveau_drm *drm = nouveau_drm(dev);
104 	struct dcb_output *dcb = dp->dcb;
105 	const u32 or = ffs(dcb->or) - 1, link = !(dcb->sorconf.link & 1);
106 	const u32 moff = (dp->crtc << 3) | (link << 2) | or;
107 	int i;
108 
109 	for (i = 0; i < dp->link_nr; i++) {
110 		u8 lane = (dp->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
111 		u8 lpre = (lane & 0x0c) >> 2;
112 		u8 lvsw = (lane & 0x03) >> 0;
113 
114 		dp->conf[i] = (lpre << 3) | lvsw;
115 		if (lvsw == DP_TRAIN_VOLTAGE_SWING_1200)
116 			dp->conf[i] |= DP_TRAIN_MAX_SWING_REACHED;
117 		if ((lpre << 3) == DP_TRAIN_PRE_EMPHASIS_9_5)
118 			dp->conf[i] |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
119 
120 		NV_DEBUG(drm, "config lane %d %02x\n", i, dp->conf[i]);
121 
122 		nv_call(dp->core, NV94_DISP_SOR_DP_DRVCTL(i) + moff, (lvsw << 8) | lpre);
123 	}
124 
125 	return nv_wraux(dp->auxch, DP_TRAINING_LANE0_SET, dp->conf, 4);
126 }
127 
128 static int
129 dp_link_train_update(struct drm_device *dev, struct dp_state *dp, u32 delay)
130 {
131 	struct nouveau_drm *drm = nouveau_drm(dev);
132 	int ret;
133 
134 	udelay(delay);
135 
136 	ret = nv_rdaux(dp->auxch, DP_LANE0_1_STATUS, dp->stat, 6);
137 	if (ret)
138 		return ret;
139 
140 	NV_DEBUG(drm, "status %*ph\n", 6, dp->stat);
141 	return 0;
142 }
143 
144 static int
145 dp_link_train_cr(struct drm_device *dev, struct dp_state *dp)
146 {
147 	bool cr_done = false, abort = false;
148 	int voltage = dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
149 	int tries = 0, i;
150 
151 	dp_set_training_pattern(dev, dp, DP_TRAINING_PATTERN_1);
152 
153 	do {
154 		if (dp_link_train_commit(dev, dp) ||
155 		    dp_link_train_update(dev, dp, 100))
156 			break;
157 
158 		cr_done = true;
159 		for (i = 0; i < dp->link_nr; i++) {
160 			u8 lane = (dp->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
161 			if (!(lane & DP_LANE_CR_DONE)) {
162 				cr_done = false;
163 				if (dp->conf[i] & DP_TRAIN_MAX_SWING_REACHED)
164 					abort = true;
165 				break;
166 			}
167 		}
168 
169 		if ((dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK) != voltage) {
170 			voltage = dp->conf[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
171 			tries = 0;
172 		}
173 	} while (!cr_done && !abort && ++tries < 5);
174 
175 	return cr_done ? 0 : -1;
176 }
177 
178 static int
179 dp_link_train_eq(struct drm_device *dev, struct dp_state *dp)
180 {
181 	bool eq_done, cr_done = true;
182 	int tries = 0, i;
183 
184 	dp_set_training_pattern(dev, dp, DP_TRAINING_PATTERN_2);
185 
186 	do {
187 		if (dp_link_train_update(dev, dp, 400))
188 			break;
189 
190 		eq_done = !!(dp->stat[2] & DP_INTERLANE_ALIGN_DONE);
191 		for (i = 0; i < dp->link_nr && eq_done; i++) {
192 			u8 lane = (dp->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
193 			if (!(lane & DP_LANE_CR_DONE))
194 				cr_done = false;
195 			if (!(lane & DP_LANE_CHANNEL_EQ_DONE) ||
196 			    !(lane & DP_LANE_SYMBOL_LOCKED))
197 				eq_done = false;
198 		}
199 
200 		if (dp_link_train_commit(dev, dp))
201 			break;
202 	} while (!eq_done && cr_done && ++tries <= 5);
203 
204 	return eq_done ? 0 : -1;
205 }
206 
207 static void
208 dp_link_train_init(struct drm_device *dev, struct dp_state *dp, bool spread)
209 {
210 	struct dcb_output *dcb = dp->dcb;
211 	const u32 or = ffs(dcb->or) - 1, link = !(dcb->sorconf.link & 1);
212 	const u32 moff = (dp->crtc << 3) | (link << 2) | or;
213 
214 	nv_call(dp->core, NV94_DISP_SOR_DP_TRAIN + moff, (spread ?
215 			  NV94_DISP_SOR_DP_TRAIN_INIT_SPREAD_ON :
216 			  NV94_DISP_SOR_DP_TRAIN_INIT_SPREAD_OFF) |
217 			  NV94_DISP_SOR_DP_TRAIN_OP_INIT);
218 }
219 
220 static void
221 dp_link_train_fini(struct drm_device *dev, struct dp_state *dp)
222 {
223 	struct dcb_output *dcb = dp->dcb;
224 	const u32 or = ffs(dcb->or) - 1, link = !(dcb->sorconf.link & 1);
225 	const u32 moff = (dp->crtc << 3) | (link << 2) | or;
226 
227 	nv_call(dp->core, NV94_DISP_SOR_DP_TRAIN + moff,
228 			  NV94_DISP_SOR_DP_TRAIN_OP_FINI);
229 }
230 
231 static bool
232 nouveau_dp_link_train(struct drm_encoder *encoder, u32 datarate,
233 		      struct nouveau_object *core)
234 {
235 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
236 	struct nouveau_crtc *nv_crtc = nouveau_crtc(encoder->crtc);
237 	struct nouveau_connector *nv_connector =
238 		nouveau_encoder_connector_get(nv_encoder);
239 	struct drm_device *dev = encoder->dev;
240 	struct nouveau_drm *drm = nouveau_drm(dev);
241 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
242 	struct nouveau_gpio *gpio = nouveau_gpio(drm->device);
243 	const u32 bw_list[] = { 270000, 162000, 0 };
244 	const u32 *link_bw = bw_list;
245 	struct dp_state dp;
246 
247 	dp.auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
248 	if (!dp.auxch)
249 		return false;
250 
251 	dp.core = core;
252 	dp.dcb = nv_encoder->dcb;
253 	dp.crtc = nv_crtc->index;
254 	dp.dpcd = nv_encoder->dp.dpcd;
255 
256 	/* adjust required bandwidth for 8B/10B coding overhead */
257 	datarate = (datarate / 8) * 10;
258 
259 	/* some sinks toggle hotplug in response to some of the actions
260 	 * we take during link training (DP_SET_POWER is one), we need
261 	 * to ignore them for the moment to avoid races.
262 	 */
263 	gpio->irq(gpio, 0, nv_connector->hpd, 0xff, false);
264 
265 	/* enable down-spreading and execute pre-train script from vbios */
266 	dp_link_train_init(dev, &dp, nv_encoder->dp.dpcd[3] & 1);
267 
268 	/* start off at highest link rate supported by encoder and display */
269 	while (*link_bw > nv_encoder->dp.link_bw)
270 		link_bw++;
271 
272 	while (link_bw[0]) {
273 		/* find minimum required lane count at this link rate */
274 		dp.link_nr = nv_encoder->dp.link_nr;
275 		while ((dp.link_nr >> 1) * link_bw[0] > datarate)
276 			dp.link_nr >>= 1;
277 
278 		/* drop link rate to minimum with this lane count */
279 		while ((link_bw[1] * dp.link_nr) > datarate)
280 			link_bw++;
281 		dp.link_bw = link_bw[0];
282 
283 		/* program selected link configuration */
284 		dp_set_link_config(dev, &dp);
285 
286 		/* attempt to train the link at this configuration */
287 		memset(dp.stat, 0x00, sizeof(dp.stat));
288 		if (!dp_link_train_cr(dev, &dp) &&
289 		    !dp_link_train_eq(dev, &dp))
290 			break;
291 
292 		/* retry at lower rate */
293 		link_bw++;
294 	}
295 
296 	/* finish link training */
297 	dp_set_training_pattern(dev, &dp, DP_TRAINING_PATTERN_DISABLE);
298 
299 	/* execute post-train script from vbios */
300 	dp_link_train_fini(dev, &dp);
301 
302 	/* re-enable hotplug detect */
303 	gpio->irq(gpio, 0, nv_connector->hpd, 0xff, true);
304 	return true;
305 }
306 
307 void
308 nouveau_dp_dpms(struct drm_encoder *encoder, int mode, u32 datarate,
309 		struct nouveau_object *core)
310 {
311 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
312 	struct nouveau_drm *drm = nouveau_drm(encoder->dev);
313 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
314 	struct nouveau_i2c_port *auxch;
315 	u8 status;
316 
317 	auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
318 	if (!auxch)
319 		return;
320 
321 	if (mode == DRM_MODE_DPMS_ON)
322 		status = DP_SET_POWER_D0;
323 	else
324 		status = DP_SET_POWER_D3;
325 
326 	nv_wraux(auxch, DP_SET_POWER, &status, 1);
327 
328 	if (mode == DRM_MODE_DPMS_ON)
329 		nouveau_dp_link_train(encoder, datarate, core);
330 }
331 
332 static void
333 nouveau_dp_probe_oui(struct drm_device *dev, struct nouveau_i2c_port *auxch,
334 		     u8 *dpcd)
335 {
336 	struct nouveau_drm *drm = nouveau_drm(dev);
337 	u8 buf[3];
338 
339 	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
340 		return;
341 
342 	if (!nv_rdaux(auxch, DP_SINK_OUI, buf, 3))
343 		NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
344 			     buf[0], buf[1], buf[2]);
345 
346 	if (!nv_rdaux(auxch, DP_BRANCH_OUI, buf, 3))
347 		NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
348 			     buf[0], buf[1], buf[2]);
349 
350 }
351 
352 bool
353 nouveau_dp_detect(struct drm_encoder *encoder)
354 {
355 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
356 	struct drm_device *dev = encoder->dev;
357 	struct nouveau_drm *drm = nouveau_drm(dev);
358 	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);
359 	struct nouveau_i2c_port *auxch;
360 	u8 *dpcd = nv_encoder->dp.dpcd;
361 	int ret;
362 
363 	auxch = i2c->find(i2c, nv_encoder->dcb->i2c_index);
364 	if (!auxch)
365 		return false;
366 
367 	ret = nv_rdaux(auxch, DP_DPCD_REV, dpcd, 8);
368 	if (ret)
369 		return false;
370 
371 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
372 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
373 
374 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
375 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
376 	NV_DEBUG(drm, "encoder: %dx%d\n",
377 		     nv_encoder->dcb->dpconf.link_nr,
378 		     nv_encoder->dcb->dpconf.link_bw);
379 
380 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
381 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
382 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
383 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
384 
385 	NV_DEBUG(drm, "maximum: %dx%d\n",
386 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
387 
388 	nouveau_dp_probe_oui(dev, auxch, dpcd);
389 
390 	return true;
391 }
392