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 		((msg->address >> 16) & 0xf);
144 	tx_buf[3] = msg->size ? (msg->size - 1) : 0;
145 
146 	switch (msg->request & ~DP_AUX_I2C_MOT) {
147 	case DP_AUX_NATIVE_WRITE:
148 	case DP_AUX_I2C_WRITE:
149 		/* tx_size needs to be 4 even for bare address packets since the atom
150 		 * table needs the info in tx_buf[3].
151 		 */
152 		tx_size = HEADER_SIZE + msg->size;
153 		if (msg->size == 0)
154 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
155 		else
156 			tx_buf[3] |= tx_size << 4;
157 		memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
158 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
159 						 tx_buf, tx_size, NULL, 0, delay, &ack);
160 		if (ret >= 0)
161 			/* Return payload size. */
162 			ret = msg->size;
163 		break;
164 	case DP_AUX_NATIVE_READ:
165 	case DP_AUX_I2C_READ:
166 		/* tx_size needs to be 4 even for bare address packets since the atom
167 		 * table needs the info in tx_buf[3].
168 		 */
169 		tx_size = HEADER_SIZE;
170 		if (msg->size == 0)
171 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
172 		else
173 			tx_buf[3] |= tx_size << 4;
174 		ret = amdgpu_atombios_dp_process_aux_ch(chan,
175 						 tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
176 		break;
177 	default:
178 		ret = -EINVAL;
179 		break;
180 	}
181 
182 	if (ret >= 0)
183 		msg->reply = ack >> 4;
184 
185 	return ret;
186 }
187 
188 void amdgpu_atombios_dp_aux_init(struct amdgpu_connector *amdgpu_connector)
189 {
190 	int ret;
191 
192 	amdgpu_connector->ddc_bus->rec.hpd = amdgpu_connector->hpd.hpd;
193 	amdgpu_connector->ddc_bus->aux.dev = amdgpu_connector->base.kdev;
194 	amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;
195 	ret = drm_dp_aux_register(&amdgpu_connector->ddc_bus->aux);
196 	if (!ret)
197 		amdgpu_connector->ddc_bus->has_aux = true;
198 
199 	WARN(ret, "drm_dp_aux_register_i2c_bus() failed with error %d\n", ret);
200 }
201 
202 /***** general DP utility functions *****/
203 
204 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_LEVEL_3
205 #define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPH_LEVEL_3
206 
207 static void amdgpu_atombios_dp_get_adjust_train(const u8 link_status[DP_LINK_STATUS_SIZE],
208 						int lane_count,
209 						u8 train_set[4])
210 {
211 	u8 v = 0;
212 	u8 p = 0;
213 	int lane;
214 
215 	for (lane = 0; lane < lane_count; lane++) {
216 		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
217 		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
218 
219 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
220 			  lane,
221 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
222 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
223 
224 		if (this_v > v)
225 			v = this_v;
226 		if (this_p > p)
227 			p = this_p;
228 	}
229 
230 	if (v >= DP_VOLTAGE_MAX)
231 		v |= DP_TRAIN_MAX_SWING_REACHED;
232 
233 	if (p >= DP_PRE_EMPHASIS_MAX)
234 		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
235 
236 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
237 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
238 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
239 
240 	for (lane = 0; lane < 4; lane++)
241 		train_set[lane] = v | p;
242 }
243 
244 /* convert bits per color to bits per pixel */
245 /* get bpc from the EDID */
246 static int amdgpu_atombios_dp_convert_bpc_to_bpp(int bpc)
247 {
248 	if (bpc == 0)
249 		return 24;
250 	else
251 		return bpc * 3;
252 }
253 
254 /* get the max pix clock supported by the link rate and lane num */
255 static int amdgpu_atombios_dp_get_max_dp_pix_clock(int link_rate,
256 					    int lane_num,
257 					    int bpp)
258 {
259 	return (link_rate * lane_num * 8) / bpp;
260 }
261 
262 /***** amdgpu specific DP functions *****/
263 
264 /* First get the min lane# when low rate is used according to pixel clock
265  * (prefer low rate), second check max lane# supported by DP panel,
266  * if the max lane# < low rate lane# then use max lane# instead.
267  */
268 static int amdgpu_atombios_dp_get_dp_lane_number(struct drm_connector *connector,
269 						 const u8 dpcd[DP_DPCD_SIZE],
270 						 int pix_clock)
271 {
272 	int bpp = amdgpu_atombios_dp_convert_bpc_to_bpp(amdgpu_connector_get_monitor_bpc(connector));
273 	int max_link_rate = drm_dp_max_link_rate(dpcd);
274 	int max_lane_num = drm_dp_max_lane_count(dpcd);
275 	int lane_num;
276 	int max_dp_pix_clock;
277 
278 	for (lane_num = 1; lane_num < max_lane_num; lane_num <<= 1) {
279 		max_dp_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(max_link_rate, lane_num, bpp);
280 		if (pix_clock <= max_dp_pix_clock)
281 			break;
282 	}
283 
284 	return lane_num;
285 }
286 
287 static int amdgpu_atombios_dp_get_dp_link_clock(struct drm_connector *connector,
288 						const u8 dpcd[DP_DPCD_SIZE],
289 						int pix_clock)
290 {
291 	int bpp = amdgpu_atombios_dp_convert_bpc_to_bpp(amdgpu_connector_get_monitor_bpc(connector));
292 	int lane_num, max_pix_clock;
293 
294 	if (amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector) ==
295 	    ENCODER_OBJECT_ID_NUTMEG)
296 		return 270000;
297 
298 	lane_num = amdgpu_atombios_dp_get_dp_lane_number(connector, dpcd, pix_clock);
299 	max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(162000, lane_num, bpp);
300 	if (pix_clock <= max_pix_clock)
301 		return 162000;
302 	max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(270000, lane_num, bpp);
303 	if (pix_clock <= max_pix_clock)
304 		return 270000;
305 	if (amdgpu_connector_is_dp12_capable(connector)) {
306 		max_pix_clock = amdgpu_atombios_dp_get_max_dp_pix_clock(540000, lane_num, bpp);
307 		if (pix_clock <= max_pix_clock)
308 			return 540000;
309 	}
310 
311 	return drm_dp_max_link_rate(dpcd);
312 }
313 
314 static u8 amdgpu_atombios_dp_encoder_service(struct amdgpu_device *adev,
315 				      int action, int dp_clock,
316 				      u8 ucconfig, u8 lane_num)
317 {
318 	DP_ENCODER_SERVICE_PARAMETERS args;
319 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
320 
321 	memset(&args, 0, sizeof(args));
322 	args.ucLinkClock = dp_clock / 10;
323 	args.ucConfig = ucconfig;
324 	args.ucAction = action;
325 	args.ucLaneNum = lane_num;
326 	args.ucStatus = 0;
327 
328 	amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
329 	return args.ucStatus;
330 }
331 
332 u8 amdgpu_atombios_dp_get_sinktype(struct amdgpu_connector *amdgpu_connector)
333 {
334 	struct drm_device *dev = amdgpu_connector->base.dev;
335 	struct amdgpu_device *adev = dev->dev_private;
336 
337 	return amdgpu_atombios_dp_encoder_service(adev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
338 					   amdgpu_connector->ddc_bus->rec.i2c_id, 0);
339 }
340 
341 static void amdgpu_atombios_dp_probe_oui(struct amdgpu_connector *amdgpu_connector)
342 {
343 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
344 	u8 buf[3];
345 
346 	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
347 		return;
348 
349 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3)
350 		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
351 			      buf[0], buf[1], buf[2]);
352 
353 	if (drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3)
354 		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
355 			      buf[0], buf[1], buf[2]);
356 }
357 
358 int amdgpu_atombios_dp_get_dpcd(struct amdgpu_connector *amdgpu_connector)
359 {
360 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
361 	u8 msg[DP_DPCD_SIZE];
362 	int ret, i;
363 
364 	for (i = 0; i < 7; i++) {
365 		ret = drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_DPCD_REV, msg,
366 				       DP_DPCD_SIZE);
367 		if (ret == DP_DPCD_SIZE) {
368 			memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
369 
370 			DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
371 				      dig_connector->dpcd);
372 
373 			amdgpu_atombios_dp_probe_oui(amdgpu_connector);
374 
375 			return 0;
376 		}
377 	}
378 	dig_connector->dpcd[0] = 0;
379 	return -EINVAL;
380 }
381 
382 int amdgpu_atombios_dp_get_panel_mode(struct drm_encoder *encoder,
383 			       struct drm_connector *connector)
384 {
385 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
386 	struct amdgpu_connector_atom_dig *dig_connector;
387 	int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
388 	u16 dp_bridge = amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector);
389 	u8 tmp;
390 
391 	if (!amdgpu_connector->con_priv)
392 		return panel_mode;
393 
394 	dig_connector = amdgpu_connector->con_priv;
395 
396 	if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
397 		/* DP bridge chips */
398 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
399 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
400 			if (tmp & 1)
401 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
402 			else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
403 				 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
404 				panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
405 			else
406 				panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
407 		}
408 	} else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
409 		/* eDP */
410 		if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux,
411 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
412 			if (tmp & 1)
413 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
414 		}
415 	}
416 
417 	return panel_mode;
418 }
419 
420 void amdgpu_atombios_dp_set_link_config(struct drm_connector *connector,
421 				 const struct drm_display_mode *mode)
422 {
423 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
424 	struct amdgpu_connector_atom_dig *dig_connector;
425 
426 	if (!amdgpu_connector->con_priv)
427 		return;
428 	dig_connector = amdgpu_connector->con_priv;
429 
430 	if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
431 	    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
432 		dig_connector->dp_clock =
433 			amdgpu_atombios_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
434 		dig_connector->dp_lane_count =
435 			amdgpu_atombios_dp_get_dp_lane_number(connector, dig_connector->dpcd, mode->clock);
436 	}
437 }
438 
439 int amdgpu_atombios_dp_mode_valid_helper(struct drm_connector *connector,
440 				  struct drm_display_mode *mode)
441 {
442 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
443 	struct amdgpu_connector_atom_dig *dig_connector;
444 	int dp_clock;
445 
446 	if (!amdgpu_connector->con_priv)
447 		return MODE_CLOCK_HIGH;
448 	dig_connector = amdgpu_connector->con_priv;
449 
450 	dp_clock =
451 		amdgpu_atombios_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
452 
453 	if ((dp_clock == 540000) &&
454 	    (!amdgpu_connector_is_dp12_capable(connector)))
455 		return MODE_CLOCK_HIGH;
456 
457 	return MODE_OK;
458 }
459 
460 bool amdgpu_atombios_dp_needs_link_train(struct amdgpu_connector *amdgpu_connector)
461 {
462 	u8 link_status[DP_LINK_STATUS_SIZE];
463 	struct amdgpu_connector_atom_dig *dig = amdgpu_connector->con_priv;
464 
465 	if (drm_dp_dpcd_read_link_status(&amdgpu_connector->ddc_bus->aux, link_status)
466 	    <= 0)
467 		return false;
468 	if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
469 		return false;
470 	return true;
471 }
472 
473 void amdgpu_atombios_dp_set_rx_power_state(struct drm_connector *connector,
474 				    u8 power_state)
475 {
476 	struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
477 	struct amdgpu_connector_atom_dig *dig_connector;
478 
479 	if (!amdgpu_connector->con_priv)
480 		return;
481 
482 	dig_connector = amdgpu_connector->con_priv;
483 
484 	/* power up/down the sink */
485 	if (dig_connector->dpcd[0] >= 0x11) {
486 		drm_dp_dpcd_writeb(&amdgpu_connector->ddc_bus->aux,
487 				   DP_SET_POWER, power_state);
488 		usleep_range(1000, 2000);
489 	}
490 }
491 
492 struct amdgpu_atombios_dp_link_train_info {
493 	struct amdgpu_device *adev;
494 	struct drm_encoder *encoder;
495 	struct drm_connector *connector;
496 	int dp_clock;
497 	int dp_lane_count;
498 	bool tp3_supported;
499 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
500 	u8 train_set[4];
501 	u8 link_status[DP_LINK_STATUS_SIZE];
502 	u8 tries;
503 	struct drm_dp_aux *aux;
504 };
505 
506 static void
507 amdgpu_atombios_dp_update_vs_emph(struct amdgpu_atombios_dp_link_train_info *dp_info)
508 {
509 	/* set the initial vs/emph on the source */
510 	amdgpu_atombios_encoder_setup_dig_transmitter(dp_info->encoder,
511 					       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
512 					       0, dp_info->train_set[0]); /* sets all lanes at once */
513 
514 	/* set the vs/emph on the sink */
515 	drm_dp_dpcd_write(dp_info->aux, DP_TRAINING_LANE0_SET,
516 			  dp_info->train_set, dp_info->dp_lane_count);
517 }
518 
519 static void
520 amdgpu_atombios_dp_set_tp(struct amdgpu_atombios_dp_link_train_info *dp_info, int tp)
521 {
522 	int rtp = 0;
523 
524 	/* set training pattern on the source */
525 	switch (tp) {
526 	case DP_TRAINING_PATTERN_1:
527 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
528 		break;
529 	case DP_TRAINING_PATTERN_2:
530 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
531 		break;
532 	case DP_TRAINING_PATTERN_3:
533 		rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
534 			break;
535 	}
536 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder, rtp, 0);
537 
538 	/* enable training pattern on the sink */
539 	drm_dp_dpcd_writeb(dp_info->aux, DP_TRAINING_PATTERN_SET, tp);
540 }
541 
542 static int
543 amdgpu_atombios_dp_link_train_init(struct amdgpu_atombios_dp_link_train_info *dp_info)
544 {
545 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(dp_info->encoder);
546 	struct amdgpu_encoder_atom_dig *dig = amdgpu_encoder->enc_priv;
547 	u8 tmp;
548 
549 	/* power up the sink */
550 	amdgpu_atombios_dp_set_rx_power_state(dp_info->connector, DP_SET_POWER_D0);
551 
552 	/* possibly enable downspread on the sink */
553 	if (dp_info->dpcd[3] & 0x1)
554 		drm_dp_dpcd_writeb(dp_info->aux,
555 				   DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
556 	else
557 		drm_dp_dpcd_writeb(dp_info->aux,
558 				   DP_DOWNSPREAD_CTRL, 0);
559 
560 	if (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)
561 		drm_dp_dpcd_writeb(dp_info->aux, DP_EDP_CONFIGURATION_SET, 1);
562 
563 	/* set the lane count on the sink */
564 	tmp = dp_info->dp_lane_count;
565 	if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
566 		tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
567 	drm_dp_dpcd_writeb(dp_info->aux, DP_LANE_COUNT_SET, tmp);
568 
569 	/* set the link rate on the sink */
570 	tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
571 	drm_dp_dpcd_writeb(dp_info->aux, DP_LINK_BW_SET, tmp);
572 
573 	/* start training on the source */
574 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
575 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
576 
577 	/* disable the training pattern on the sink */
578 	drm_dp_dpcd_writeb(dp_info->aux,
579 			   DP_TRAINING_PATTERN_SET,
580 			   DP_TRAINING_PATTERN_DISABLE);
581 
582 	return 0;
583 }
584 
585 static int
586 amdgpu_atombios_dp_link_train_finish(struct amdgpu_atombios_dp_link_train_info *dp_info)
587 {
588 	udelay(400);
589 
590 	/* disable the training pattern on the sink */
591 	drm_dp_dpcd_writeb(dp_info->aux,
592 			   DP_TRAINING_PATTERN_SET,
593 			   DP_TRAINING_PATTERN_DISABLE);
594 
595 	/* disable the training pattern on the source */
596 	amdgpu_atombios_encoder_setup_dig_encoder(dp_info->encoder,
597 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
598 
599 	return 0;
600 }
601 
602 static int
603 amdgpu_atombios_dp_link_train_cr(struct amdgpu_atombios_dp_link_train_info *dp_info)
604 {
605 	bool clock_recovery;
606 	u8 voltage;
607 	int i;
608 
609 	amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
610 	memset(dp_info->train_set, 0, 4);
611 	amdgpu_atombios_dp_update_vs_emph(dp_info);
612 
613 	udelay(400);
614 
615 	/* clock recovery loop */
616 	clock_recovery = false;
617 	dp_info->tries = 0;
618 	voltage = 0xff;
619 	while (1) {
620 		drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);
621 
622 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
623 						 dp_info->link_status) <= 0) {
624 			DRM_ERROR("displayport link status failed\n");
625 			break;
626 		}
627 
628 		if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
629 			clock_recovery = true;
630 			break;
631 		}
632 
633 		for (i = 0; i < dp_info->dp_lane_count; i++) {
634 			if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
635 				break;
636 		}
637 		if (i == dp_info->dp_lane_count) {
638 			DRM_ERROR("clock recovery reached max voltage\n");
639 			break;
640 		}
641 
642 		if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
643 			++dp_info->tries;
644 			if (dp_info->tries == 5) {
645 				DRM_ERROR("clock recovery tried 5 times\n");
646 				break;
647 			}
648 		} else
649 			dp_info->tries = 0;
650 
651 		voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
652 
653 		/* Compute new train_set as requested by sink */
654 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
655 					     dp_info->train_set);
656 
657 		amdgpu_atombios_dp_update_vs_emph(dp_info);
658 	}
659 	if (!clock_recovery) {
660 		DRM_ERROR("clock recovery failed\n");
661 		return -1;
662 	} else {
663 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
664 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
665 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
666 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
667 		return 0;
668 	}
669 }
670 
671 static int
672 amdgpu_atombios_dp_link_train_ce(struct amdgpu_atombios_dp_link_train_info *dp_info)
673 {
674 	bool channel_eq;
675 
676 	if (dp_info->tp3_supported)
677 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
678 	else
679 		amdgpu_atombios_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
680 
681 	/* channel equalization loop */
682 	dp_info->tries = 0;
683 	channel_eq = false;
684 	while (1) {
685 		drm_dp_link_train_channel_eq_delay(dp_info->dpcd);
686 
687 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
688 						 dp_info->link_status) <= 0) {
689 			DRM_ERROR("displayport link status failed\n");
690 			break;
691 		}
692 
693 		if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
694 			channel_eq = true;
695 			break;
696 		}
697 
698 		/* Try 5 times */
699 		if (dp_info->tries > 5) {
700 			DRM_ERROR("channel eq failed: 5 tries\n");
701 			break;
702 		}
703 
704 		/* Compute new train_set as requested by sink */
705 		amdgpu_atombios_dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count,
706 					     dp_info->train_set);
707 
708 		amdgpu_atombios_dp_update_vs_emph(dp_info);
709 		dp_info->tries++;
710 	}
711 
712 	if (!channel_eq) {
713 		DRM_ERROR("channel eq failed\n");
714 		return -1;
715 	} else {
716 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
717 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
718 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
719 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
720 		return 0;
721 	}
722 }
723 
724 void amdgpu_atombios_dp_link_train(struct drm_encoder *encoder,
725 			    struct drm_connector *connector)
726 {
727 	struct drm_device *dev = encoder->dev;
728 	struct amdgpu_device *adev = dev->dev_private;
729 	struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(encoder);
730 	struct amdgpu_encoder_atom_dig *dig;
731 	struct amdgpu_connector *amdgpu_connector;
732 	struct amdgpu_connector_atom_dig *dig_connector;
733 	struct amdgpu_atombios_dp_link_train_info dp_info;
734 	u8 tmp;
735 
736 	if (!amdgpu_encoder->enc_priv)
737 		return;
738 	dig = amdgpu_encoder->enc_priv;
739 
740 	amdgpu_connector = to_amdgpu_connector(connector);
741 	if (!amdgpu_connector->con_priv)
742 		return;
743 	dig_connector = amdgpu_connector->con_priv;
744 
745 	if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
746 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
747 		return;
748 
749 	if (drm_dp_dpcd_readb(&amdgpu_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp)
750 	    == 1) {
751 		if (tmp & DP_TPS3_SUPPORTED)
752 			dp_info.tp3_supported = true;
753 		else
754 			dp_info.tp3_supported = false;
755 	} else {
756 		dp_info.tp3_supported = false;
757 	}
758 
759 	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
760 	dp_info.adev = adev;
761 	dp_info.encoder = encoder;
762 	dp_info.connector = connector;
763 	dp_info.dp_lane_count = dig_connector->dp_lane_count;
764 	dp_info.dp_clock = dig_connector->dp_clock;
765 	dp_info.aux = &amdgpu_connector->ddc_bus->aux;
766 
767 	if (amdgpu_atombios_dp_link_train_init(&dp_info))
768 		goto done;
769 	if (amdgpu_atombios_dp_link_train_cr(&dp_info))
770 		goto done;
771 	if (amdgpu_atombios_dp_link_train_ce(&dp_info))
772 		goto done;
773 done:
774 	if (amdgpu_atombios_dp_link_train_finish(&dp_info))
775 		return;
776 }
777