1 /*
2  * Copyright 2007-8 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors: Dave Airlie
24  *          Alex Deucher
25  *          Jerome Glisse
26  */
27 #include <drm/drmP.h>
28 #include <drm/amdgpu_drm.h>
29 #include "amdgpu.h"
30 
31 #include "atom.h"
32 #include "atom-bits.h"
33 #include "atombios_encoders.h"
34 #include "atombios_dp.h"
35 #include "amdgpu_connectors.h"
36 #include "amdgpu_atombios.h"
37 #include <drm/drm_dp_helper.h>
38 
39 /* move these to drm_dp_helper.c/h */
40 #define DP_LINK_CONFIGURATION_SIZE 9
41 #define DP_DPCD_SIZE DP_RECEIVER_CAP_SIZE
42 
43 static char *voltage_names[] = {
44 	"0.4V", "0.6V", "0.8V", "1.2V"
45 };
46 static char *pre_emph_names[] = {
47 	"0dB", "3.5dB", "6dB", "9.5dB"
48 };
49 
50 /***** amdgpu AUX functions *****/
51 
52 union aux_channel_transaction {
53 	PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
54 	PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
55 };
56 
57 static int amdgpu_atombios_dp_process_aux_ch(struct amdgpu_i2c_chan *chan,
58 				      u8 *send, int send_bytes,
59 				      u8 *recv, int recv_size,
60 				      u8 delay, u8 *ack)
61 {
62 	struct drm_device *dev = chan->dev;
63 	struct amdgpu_device *adev = dev->dev_private;
64 	union aux_channel_transaction args;
65 	int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
66 	unsigned char *base;
67 	int recv_bytes;
68 	int r = 0;
69 
70 	memset(&args, 0, sizeof(args));
71 
72 	mutex_lock(&chan->mutex);
73 
74 	base = (unsigned char *)(adev->mode_info.atom_context->scratch + 1);
75 
76 	amdgpu_atombios_copy_swap(base, send, send_bytes, true);
77 
78 	args.v2.lpAuxRequest = cpu_to_le16((u16)(0 + 4));
79 	args.v2.lpDataOut = cpu_to_le16((u16)(16 + 4));
80 	args.v2.ucDataOutLen = 0;
81 	args.v2.ucChannelID = chan->rec.i2c_id;
82 	args.v2.ucDelay = delay / 10;
83 	args.v2.ucHPD_ID = chan->rec.hpd;
84 
85 	amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
86 
87 	*ack = args.v2.ucReplyStatus;
88 
89 	/* timeout */
90 	if (args.v2.ucReplyStatus == 1) {
91 		DRM_DEBUG_KMS("dp_aux_ch timeout\n");
92 		r = -ETIMEDOUT;
93 		goto done;
94 	}
95 
96 	/* flags not zero */
97 	if (args.v2.ucReplyStatus == 2) {
98 		DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
99 		r = -EIO;
100 		goto done;
101 	}
102 
103 	/* error */
104 	if (args.v2.ucReplyStatus == 3) {
105 		DRM_DEBUG_KMS("dp_aux_ch error\n");
106 		r = -EIO;
107 		goto done;
108 	}
109 
110 	recv_bytes = args.v1.ucDataOutLen;
111 	if (recv_bytes > recv_size)
112 		recv_bytes = recv_size;
113 
114 	if (recv && recv_size)
115 		amdgpu_atombios_copy_swap(recv, base + 16, recv_bytes, false);
116 
117 	r = recv_bytes;
118 done:
119 	mutex_unlock(&chan->mutex);
120 
121 	return r;
122 }
123 
124 #define BARE_ADDRESS_SIZE 3
125 #define HEADER_SIZE (BARE_ADDRESS_SIZE + 1)
126 
127 static ssize_t
128 amdgpu_atombios_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
129 {
130 	struct amdgpu_i2c_chan *chan =
131 		container_of(aux, struct amdgpu_i2c_chan, aux);
132 	int ret;
133 	u8 tx_buf[20];
134 	size_t tx_size;
135 	u8 ack, delay = 0;
136 
137 	if (WARN_ON(msg->size > 16))
138 		return -E2BIG;
139 
140 	tx_buf[0] = msg->address & 0xff;
141 	tx_buf[1] = msg->address >> 8;
142 	tx_buf[2] = msg->request << 4;
143 	tx_buf[3] = msg->size ? (msg->size - 1) : 0;
144 
145 	switch (msg->request & ~DP_AUX_I2C_MOT) {
146 	case DP_AUX_NATIVE_WRITE:
147 	case DP_AUX_I2C_WRITE:
148 		/* tx_size needs to be 4 even for bare address packets since the atom
149 		 * table needs the info in tx_buf[3].
150 		 */
151 		tx_size = HEADER_SIZE + msg->size;
152 		if (msg->size == 0)
153 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
154 		else
155 			tx_buf[3] |= tx_size << 4;
156 		memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
157 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
158 						 tx_buf, tx_size, NULL, 0, delay, &ack);
159 		if (ret >= 0)
160 			/* Return payload size. */
161 			ret = msg->size;
162 		break;
163 	case DP_AUX_NATIVE_READ:
164 	case DP_AUX_I2C_READ:
165 		/* tx_size needs to be 4 even for bare address packets since the atom
166 		 * table needs the info in tx_buf[3].
167 		 */
168 		tx_size = HEADER_SIZE;
169 		if (msg->size == 0)
170 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
171 		else
172 			tx_buf[3] |= tx_size << 4;
173 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
174 						 tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
175 		break;
176 	default:
177 		ret = -EINVAL;
178 		break;
179 	}
180 
181 	if (ret >= 0)
182 		msg->reply = ack >> 4;
183 
184 	return ret;
185 }
186 
187 void amdgpu_atombios_dp_aux_init(struct amdgpu_connector *amdgpu_connector)
188 {
189 	int ret;
190 
191 	amdgpu_connector->ddc_bus->rec.hpd = amdgpu_connector->hpd.hpd;
192 	amdgpu_connector->ddc_bus->aux.dev = amdgpu_connector->base.kdev;
193 	amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;
194 	ret = drm_dp_aux_register(&amdgpu_connector->ddc_bus->aux);
195 	if (!ret)
196 		amdgpu_connector->ddc_bus->has_aux = true;
197 
198 	WARN(ret, "drm_dp_aux_register_i2c_bus() failed with error %d\n", ret);
199 }
200 
201 /***** general DP utility functions *****/
202 
203 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_LEVEL_3
204 #define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPH_LEVEL_3
205 
206 static void amdgpu_atombios_dp_get_adjust_train(const u8 link_status[DP_LINK_STATUS_SIZE],
207 						int lane_count,
208 						u8 train_set[4])
209 {
210 	u8 v = 0;
211 	u8 p = 0;
212 	int lane;
213 
214 	for (lane = 0; lane < lane_count; lane++) {
215 		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
216 		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
217 
218 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
219 			  lane,
220 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
221 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
222 
223 		if (this_v > v)
224 			v = this_v;
225 		if (this_p > p)
226 			p = this_p;
227 	}
228 
229 	if (v >= DP_VOLTAGE_MAX)
230 		v |= DP_TRAIN_MAX_SWING_REACHED;
231 
232 	if (p >= DP_PRE_EMPHASIS_MAX)
233 		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
234 
235 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
236 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
237 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
238 
239 	for (lane = 0; lane < 4; lane++)
240 		train_set[lane] = v | p;
241 }
242 
243 /* convert bits per color to bits per pixel */
244 /* get bpc from the EDID */
245 static int amdgpu_atombios_dp_convert_bpc_to_bpp(int bpc)
246 {
247 	if (bpc == 0)
248 		return 24;
249 	else
250 		return bpc * 3;
251 }
252 
253 /* get the max pix clock supported by the link rate and lane num */
254 static int amdgpu_atombios_dp_get_max_dp_pix_clock(int link_rate,
255 					    int lane_num,
256 					    int bpp)
257 {
258 	return (link_rate * lane_num * 8) / bpp;
259 }
260 
261 /***** amdgpu specific DP functions *****/
262 
263 /* First get the min lane# when low rate is used according to pixel clock
264  * (prefer low rate), second check max lane# supported by DP panel,
265  * if the max lane# < low rate lane# then use max lane# instead.
266  */
267 static int amdgpu_atombios_dp_get_dp_lane_number(struct drm_connector *connector,
268 						 const u8 dpcd[DP_DPCD_SIZE],
269 						 int pix_clock)
270 {
271 	int bpp = amdgpu_atombios_dp_convert_bpc_to_bpp(amdgpu_connector_get_monitor_bpc(connector));
272 	int max_link_rate = drm_dp_max_link_rate(dpcd);
273 	int max_lane_num = drm_dp_max_lane_count(dpcd);
274 	int lane_num;
275 	int max_dp_pix_clock;
276 
277 	for (lane_num = 1; lane_num < max_lane_num; lane_num <<= 1) {
278 		max_dp_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(max_link_rate, lane_num, bpp);
279 		if (pix_clock <= max_dp_pix_clock)
280 			break;
281 	}
282 
283 	return lane_num;
284 }
285 
286 static int amdgpu_atombios_dp_get_dp_link_clock(struct drm_connector *connector,
287 						const u8 dpcd[DP_DPCD_SIZE],
288 						int pix_clock)
289 {
290 	int bpp = amdgpu_atombios_dp_convert_bpc_to_bpp(amdgpu_connector_get_monitor_bpc(connector));
291 	int lane_num, max_pix_clock;
292 
293 	if (amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector) ==
294 	    ENCODER_OBJECT_ID_NUTMEG)
295 		return 270000;
296 
297 	lane_num = amdgpu_atombios_dp_get_dp_lane_number(connector, dpcd, pix_clock);
298 	max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(162000, lane_num, bpp);
299 	if (pix_clock <= max_pix_clock)
300 		return 162000;
301 	max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(270000, lane_num, bpp);
302 	if (pix_clock <= max_pix_clock)
303 		return 270000;
304 	if (amdgpu_connector_is_dp12_capable(connector)) {
305 		max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(540000, lane_num, bpp);
306 		if (pix_clock <= max_pix_clock)
307 			return 540000;
308 	}
309 
310 	return drm_dp_max_link_rate(dpcd);
311 }
312 
313 static u8 amdgpu_atombios_dp_encoder_service(struct amdgpu_device *adev,
314 				      int action, int dp_clock,
315 				      u8 ucconfig, u8 lane_num)
316 {
317 	DP_ENCODER_SERVICE_PARAMETERS args;
318 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
319 
320 	memset(&args, 0, sizeof(args));
321 	args.ucLinkClock = dp_clock / 10;
322 	args.ucConfig = ucconfig;
323 	args.ucAction = action;
324 	args.ucLaneNum = lane_num;
325 	args.ucStatus = 0;
326 
327 	amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
328 	return args.ucStatus;
329 }
330 
331 u8 amdgpu_atombios_dp_get_sinktype(struct amdgpu_connector *amdgpu_connector)
332 {
333 	struct drm_device *dev = amdgpu_connector->base.dev;
334 	struct amdgpu_device *adev = dev->dev_private;
335 
336 	return amdgpu_atombios_dp_encoder_service(adev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
337 					   amdgpu_connector->ddc_bus->rec.i2c_id, 0);
338 }
339 
340 static void amdgpu_atombios_dp_probe_oui(struct amdgpu_connector *amdgpu_connector)
341 {
342 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
343 	u8 buf[3];
344 
345 	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
346 		return;
347 
348 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3)
349 		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
350 			      buf[0], buf[1], buf[2]);
351 
352 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3)
353 		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
354 			      buf[0], buf[1], buf[2]);
355 }
356 
357 int amdgpu_atombios_dp_get_dpcd(struct amdgpu_connector *amdgpu_connector)
358 {
359 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
360 	u8 msg[DP_DPCD_SIZE];
361 	int ret, i;
362 
363 	for (i = 0; i < 7; i++) {
364 		ret = drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_DPCD_REV, msg,
365 				       DP_DPCD_SIZE);
366 		if (ret == DP_DPCD_SIZE) {
367 			memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
368 
369 			DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
370 				      dig_connector->dpcd);
371 
372 			amdgpu_atombios_dp_probe_oui(amdgpu_connector);
373 
374 			return 0;
375 		}
376 	}
377 	dig_connector->dpcd[0] = 0;
378 	return -EINVAL;
379 }
380 
381 int amdgpu_atombios_dp_get_panel_mode(struct drm_encoder *encoder,
382 			       struct drm_connector *connector)
383 {
384 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
385 	struct amdgpu_connector_atom_dig *dig_connector;
386 	int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
387 	u16 dp_bridge = amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector);
388 	u8 tmp;
389 
390 	if (!amdgpu_connector->con_priv)
391 		return panel_mode;
392 
393 	dig_connector = amdgpu_connector->con_priv;
394 
395 	if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
396 		/* DP bridge chips */
397 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
398 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
399 			if (tmp & 1)
400 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
401 			else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
402 				 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
403 				panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
404 			else
405 				panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
406 		}
407 	} else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
408 		/* eDP */
409 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
410 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
411 			if (tmp & 1)
412 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
413 		}
414 	}
415 
416 	return panel_mode;
417 }
418 
419 void amdgpu_atombios_dp_set_link_config(struct drm_connector *connector,
420 				 const struct drm_display_mode *mode)
421 {
422 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
423 	struct amdgpu_connector_atom_dig *dig_connector;
424 
425 	if (!amdgpu_connector->con_priv)
426 		return;
427 	dig_connector = amdgpu_connector->con_priv;
428 
429 	if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
430 	    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
431 		dig_connector->dp_clock =
432 			amdgpu_atombios_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
433 		dig_connector->dp_lane_count =
434 			amdgpu_atombios_dp_get_dp_lane_number(connector, dig_connector->dpcd, mode->clock);
435 	}
436 }
437 
438 int amdgpu_atombios_dp_mode_valid_helper(struct drm_connector *connector,
439 				  struct drm_display_mode *mode)
440 {
441 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
442 	struct amdgpu_connector_atom_dig *dig_connector;
443 	int dp_clock;
444 
445 	if (!amdgpu_connector->con_priv)
446 		return MODE_CLOCK_HIGH;
447 	dig_connector = amdgpu_connector->con_priv;
448 
449 	dp_clock =
450 		amdgpu_atombios_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
451 
452 	if ((dp_clock == 540000) &&
453 	    (!amdgpu_connector_is_dp12_capable(connector)))
454 		return MODE_CLOCK_HIGH;
455 
456 	return MODE_OK;
457 }
458 
459 bool amdgpu_atombios_dp_needs_link_train(struct amdgpu_connector *amdgpu_connector)
460 {
461 	u8 link_status[DP_LINK_STATUS_SIZE];
462 	struct amdgpu_connector_atom_dig *dig = amdgpu_connector->con_priv;
463 
464 	if (drm_dp_dpcd_read_link_status(&amdgpu_connector->ddc_bus->aux, link_status)
465 	    <= 0)
466 		return false;
467 	if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
468 		return false;
469 	return true;
470 }
471 
472 void amdgpu_atombios_dp_set_rx_power_state(struct drm_connector *connector,
473 				    u8 power_state)
474 {
475 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
476 	struct amdgpu_connector_atom_dig *dig_connector;
477 
478 	if (!amdgpu_connector->con_priv)
479 		return;
480 
481 	dig_connector = amdgpu_connector->con_priv;
482 
483 	/* power up/down the sink */
484 	if (dig_connector->dpcd[0] >= 0x11) {
485 		drm_dp_dpcd_writeb(&amdgpu_connector->ddc_bus->aux,
486 				   DP_SET_POWER, power_state);
487 		usleep_range(1000, 2000);
488 	}
489 }
490 
491 struct amdgpu_atombios_dp_link_train_info {
492 	struct amdgpu_device *adev;
493 	struct drm_encoder *encoder;
494 	struct drm_connector *connector;
495 	int dp_clock;
496 	int dp_lane_count;
497 	bool tp3_supported;
498 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
499 	u8 train_set[4];
500 	u8 link_status[DP_LINK_STATUS_SIZE];
501 	u8 tries;
502 	struct drm_dp_aux *aux;
503 };
504 
505 static void
506 amdgpu_atombios_dp_update_vs_emph(struct amdgpu_atombios_dp_link_train_info *dp_info)
507 {
508 	/* set the initial vs/emph on the source */
509 	amdgpu_atombios_encoder_setup_dig_transmitter(dp_info->encoder,
510 					       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
511 					       0, dp_info->train_set[0]); /* sets all lanes at once */
512 
513 	/* set the vs/emph on the sink */
514 	drm_dp_dpcd_write(dp_info->aux, DP_TRAINING_LANE0_SET,
515 			  dp_info->train_set, dp_info->dp_lane_count);
516 }
517 
518 static void
519 amdgpu_atombios_dp_set_tp(struct amdgpu_atombios_dp_link_train_info *dp_info, int tp)
520 {
521 	int rtp = 0;
522 
523 	/* set training pattern on the source */
524 	switch (tp) {
525 	case DP_TRAINING_PATTERN_1:
526 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
527 		break;
528 	case DP_TRAINING_PATTERN_2:
529 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
530 		break;
531 	case DP_TRAINING_PATTERN_3:
532 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
533 			break;
534 	}
535 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder, rtp, 0);
536 
537 	/* enable training pattern on the sink */
538 	drm_dp_dpcd_writeb(dp_info->aux, DP_TRAINING_PATTERN_SET, tp);
539 }
540 
541 static int
542 amdgpu_atombios_dp_link_train_init(struct amdgpu_atombios_dp_link_train_info *dp_info)
543 {
544 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(dp_info->encoder);
545 	struct amdgpu_encoder_atom_dig *dig = amdgpu_encoder->enc_priv;
546 	u8 tmp;
547 
548 	/* power up the sink */
549 	amdgpu_atombios_dp_set_rx_power_state(dp_info->connector, DP_SET_POWER_D0);
550 
551 	/* possibly enable downspread on the sink */
552 	if (dp_info->dpcd[3] & 0x1)
553 		drm_dp_dpcd_writeb(dp_info->aux,
554 				   DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
555 	else
556 		drm_dp_dpcd_writeb(dp_info->aux,
557 				   DP_DOWNSPREAD_CTRL, 0);
558 
559 	if (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)
560 		drm_dp_dpcd_writeb(dp_info->aux, DP_EDP_CONFIGURATION_SET, 1);
561 
562 	/* set the lane count on the sink */
563 	tmp = dp_info->dp_lane_count;
564 	if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
565 		tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
566 	drm_dp_dpcd_writeb(dp_info->aux, DP_LANE_COUNT_SET, tmp);
567 
568 	/* set the link rate on the sink */
569 	tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
570 	drm_dp_dpcd_writeb(dp_info->aux, DP_LINK_BW_SET, tmp);
571 
572 	/* start training on the source */
573 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
574 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
575 
576 	/* disable the training pattern on the sink */
577 	drm_dp_dpcd_writeb(dp_info->aux,
578 			   DP_TRAINING_PATTERN_SET,
579 			   DP_TRAINING_PATTERN_DISABLE);
580 
581 	return 0;
582 }
583 
584 static int
585 amdgpu_atombios_dp_link_train_finish(struct amdgpu_atombios_dp_link_train_info *dp_info)
586 {
587 	udelay(400);
588 
589 	/* disable the training pattern on the sink */
590 	drm_dp_dpcd_writeb(dp_info->aux,
591 			   DP_TRAINING_PATTERN_SET,
592 			   DP_TRAINING_PATTERN_DISABLE);
593 
594 	/* disable the training pattern on the source */
595 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
596 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
597 
598 	return 0;
599 }
600 
601 static int
602 amdgpu_atombios_dp_link_train_cr(struct amdgpu_atombios_dp_link_train_info *dp_info)
603 {
604 	bool clock_recovery;
605 	u8 voltage;
606 	int i;
607 
608 	amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
609 	memset(dp_info->train_set, 0, 4);
610 	amdgpu_atombios_dp_update_vs_emph(dp_info);
611 
612 	udelay(400);
613 
614 	/* clock recovery loop */
615 	clock_recovery = false;
616 	dp_info->tries = 0;
617 	voltage = 0xff;
618 	while (1) {
619 		drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);
620 
621 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
622 						 dp_info->link_status) <= 0) {
623 			DRM_ERROR("displayport link status failed\n");
624 			break;
625 		}
626 
627 		if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
628 			clock_recovery = true;
629 			break;
630 		}
631 
632 		for (i = 0; i < dp_info->dp_lane_count; i++) {
633 			if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
634 				break;
635 		}
636 		if (i == dp_info->dp_lane_count) {
637 			DRM_ERROR("clock recovery reached max voltage\n");
638 			break;
639 		}
640 
641 		if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
642 			++dp_info->tries;
643 			if (dp_info->tries == 5) {
644 				DRM_ERROR("clock recovery tried 5 times\n");
645 				break;
646 			}
647 		} else
648 			dp_info->tries = 0;
649 
650 		voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
651 
652 		/* Compute new train_set as requested by sink */
653 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
654 					     dp_info->train_set);
655 
656 		amdgpu_atombios_dp_update_vs_emph(dp_info);
657 	}
658 	if (!clock_recovery) {
659 		DRM_ERROR("clock recovery failed\n");
660 		return -1;
661 	} else {
662 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
663 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
664 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
665 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
666 		return 0;
667 	}
668 }
669 
670 static int
671 amdgpu_atombios_dp_link_train_ce(struct amdgpu_atombios_dp_link_train_info *dp_info)
672 {
673 	bool channel_eq;
674 
675 	if (dp_info->tp3_supported)
676 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
677 	else
678 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
679 
680 	/* channel equalization loop */
681 	dp_info->tries = 0;
682 	channel_eq = false;
683 	while (1) {
684 		drm_dp_link_train_channel_eq_delay(dp_info->dpcd);
685 
686 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
687 						 dp_info->link_status) <= 0) {
688 			DRM_ERROR("displayport link status failed\n");
689 			break;
690 		}
691 
692 		if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
693 			channel_eq = true;
694 			break;
695 		}
696 
697 		/* Try 5 times */
698 		if (dp_info->tries > 5) {
699 			DRM_ERROR("channel eq failed: 5 tries\n");
700 			break;
701 		}
702 
703 		/* Compute new train_set as requested by sink */
704 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
705 					     dp_info->train_set);
706 
707 		amdgpu_atombios_dp_update_vs_emph(dp_info);
708 		dp_info->tries++;
709 	}
710 
711 	if (!channel_eq) {
712 		DRM_ERROR("channel eq failed\n");
713 		return -1;
714 	} else {
715 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
716 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
717 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
718 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
719 		return 0;
720 	}
721 }
722 
723 void amdgpu_atombios_dp_link_train(struct drm_encoder *encoder,
724 			    struct drm_connector *connector)
725 {
726 	struct drm_device *dev = encoder->dev;
727 	struct amdgpu_device *adev = dev->dev_private;
728 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(encoder);
729 	struct amdgpu_encoder_atom_dig *dig;
730 	struct amdgpu_connector *amdgpu_connector;
731 	struct amdgpu_connector_atom_dig *dig_connector;
732 	struct amdgpu_atombios_dp_link_train_info dp_info;
733 	u8 tmp;
734 
735 	if (!amdgpu_encoder->enc_priv)
736 		return;
737 	dig = amdgpu_encoder->enc_priv;
738 
739 	amdgpu_connector = to_amdgpu_connector(connector);
740 	if (!amdgpu_connector->con_priv)
741 		return;
742 	dig_connector = amdgpu_connector->con_priv;
743 
744 	if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
745 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
746 		return;
747 
748 	if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp)
749 	    == 1) {
750 		if (tmp & DP_TPS3_SUPPORTED)
751 			dp_info.tp3_supported = true;
752 		else
753 			dp_info.tp3_supported = false;
754 	} else {
755 		dp_info.tp3_supported = false;
756 	}
757 
758 	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
759 	dp_info.adev = adev;
760 	dp_info.encoder = encoder;
761 	dp_info.connector = connector;
762 	dp_info.dp_lane_count = dig_connector->dp_lane_count;
763 	dp_info.dp_clock = dig_connector->dp_clock;
764 	dp_info.aux = &amdgpu_connector->ddc_bus->aux;
765 
766 	if (amdgpu_atombios_dp_link_train_init(&dp_info))
767 		goto done;
768 	if (amdgpu_atombios_dp_link_train_cr(&dp_info))
769 		goto done;
770 	if (amdgpu_atombios_dp_link_train_ce(&dp_info))
771 		goto done;
772 done:
773 	if (amdgpu_atombios_dp_link_train_finish(&dp_info))
774 		return;
775 }
776