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 
28 #include <drm/radeon_drm.h>
29 #include "radeon.h"
30 
31 #include "atom.h"
32 #include "atom-bits.h"
33 #include <drm/display/drm_dp_helper.h>
34 
35 /* move these to drm_dp_helper.c/h */
36 #define DP_LINK_CONFIGURATION_SIZE 9
37 #define DP_DPCD_SIZE DP_RECEIVER_CAP_SIZE
38 
39 static char *voltage_names[] = {
40 	"0.4V", "0.6V", "0.8V", "1.2V"
41 };
42 static char *pre_emph_names[] = {
43 	"0dB", "3.5dB", "6dB", "9.5dB"
44 };
45 
46 /***** radeon AUX functions *****/
47 
48 /* Atom needs data in little endian format so swap as appropriate when copying
49  * data to or from atom. Note that atom operates on dw units.
50  *
51  * Use to_le=true when sending data to atom and provide at least
52  * ALIGN(num_bytes,4) bytes in the dst buffer.
53  *
54  * Use to_le=false when receiving data from atom and provide ALIGN(num_bytes,4)
55  * byes in the src buffer.
56  */
57 void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le)
58 {
59 #ifdef __BIG_ENDIAN
60 	u32 src_tmp[5], dst_tmp[5];
61 	int i;
62 	u8 align_num_bytes = ALIGN(num_bytes, 4);
63 
64 	if (to_le) {
65 		memcpy(src_tmp, src, num_bytes);
66 		for (i = 0; i < align_num_bytes / 4; i++)
67 			dst_tmp[i] = cpu_to_le32(src_tmp[i]);
68 		memcpy(dst, dst_tmp, align_num_bytes);
69 	} else {
70 		memcpy(src_tmp, src, align_num_bytes);
71 		for (i = 0; i < align_num_bytes / 4; i++)
72 			dst_tmp[i] = le32_to_cpu(src_tmp[i]);
73 		memcpy(dst, dst_tmp, num_bytes);
74 	}
75 #else
76 	memcpy(dst, src, num_bytes);
77 #endif
78 }
79 
80 union aux_channel_transaction {
81 	PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
82 	PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
83 };
84 
85 static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
86 				 u8 *send, int send_bytes,
87 				 u8 *recv, int recv_size,
88 				 u8 delay, u8 *ack)
89 {
90 	struct drm_device *dev = chan->dev;
91 	struct radeon_device *rdev = dev->dev_private;
92 	union aux_channel_transaction args;
93 	int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
94 	unsigned char *base;
95 	int recv_bytes;
96 	int r = 0;
97 
98 	memset(&args, 0, sizeof(args));
99 
100 	mutex_lock(&chan->mutex);
101 	mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
102 
103 	base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
104 
105 	radeon_atom_copy_swap(base, send, send_bytes, true);
106 
107 	args.v1.lpAuxRequest = cpu_to_le16((u16)(0 + 4));
108 	args.v1.lpDataOut = cpu_to_le16((u16)(16 + 4));
109 	args.v1.ucDataOutLen = 0;
110 	args.v1.ucChannelID = chan->rec.i2c_id;
111 	args.v1.ucDelay = delay / 10;
112 	if (ASIC_IS_DCE4(rdev))
113 		args.v2.ucHPD_ID = chan->rec.hpd;
114 
115 	atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
116 
117 	*ack = args.v1.ucReplyStatus;
118 
119 	/* timeout */
120 	if (args.v1.ucReplyStatus == 1) {
121 		DRM_DEBUG_KMS("dp_aux_ch timeout\n");
122 		r = -ETIMEDOUT;
123 		goto done;
124 	}
125 
126 	/* flags not zero */
127 	if (args.v1.ucReplyStatus == 2) {
128 		DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
129 		r = -EIO;
130 		goto done;
131 	}
132 
133 	/* error */
134 	if (args.v1.ucReplyStatus == 3) {
135 		DRM_DEBUG_KMS("dp_aux_ch error\n");
136 		r = -EIO;
137 		goto done;
138 	}
139 
140 	recv_bytes = args.v1.ucDataOutLen;
141 	if (recv_bytes > recv_size)
142 		recv_bytes = recv_size;
143 
144 	if (recv && recv_size)
145 		radeon_atom_copy_swap(recv, base + 16, recv_bytes, false);
146 
147 	r = recv_bytes;
148 done:
149 	mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
150 	mutex_unlock(&chan->mutex);
151 
152 	return r;
153 }
154 
155 #define BARE_ADDRESS_SIZE 3
156 #define HEADER_SIZE (BARE_ADDRESS_SIZE + 1)
157 
158 static ssize_t
159 radeon_dp_aux_transfer_atom(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
160 {
161 	struct radeon_i2c_chan *chan =
162 		container_of(aux, struct radeon_i2c_chan, aux);
163 	int ret;
164 	u8 tx_buf[20];
165 	size_t tx_size;
166 	u8 ack, delay = 0;
167 
168 	if (WARN_ON(msg->size > 16))
169 		return -E2BIG;
170 
171 	tx_buf[0] = msg->address & 0xff;
172 	tx_buf[1] = (msg->address >> 8) & 0xff;
173 	tx_buf[2] = (msg->request << 4) |
174 		((msg->address >> 16) & 0xf);
175 	tx_buf[3] = msg->size ? (msg->size - 1) : 0;
176 
177 	switch (msg->request & ~DP_AUX_I2C_MOT) {
178 	case DP_AUX_NATIVE_WRITE:
179 	case DP_AUX_I2C_WRITE:
180 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
181 		/* The atom implementation only supports writes with a max payload of
182 		 * 12 bytes since it uses 4 bits for the total count (header + payload)
183 		 * in the parameter space.  The atom interface supports 16 byte
184 		 * payloads for reads. The hw itself supports up to 16 bytes of payload.
185 		 */
186 		if (WARN_ON_ONCE(msg->size > 12))
187 			return -E2BIG;
188 		/* tx_size needs to be 4 even for bare address packets since the atom
189 		 * table needs the info in tx_buf[3].
190 		 */
191 		tx_size = HEADER_SIZE + msg->size;
192 		if (msg->size == 0)
193 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
194 		else
195 			tx_buf[3] |= tx_size << 4;
196 		memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
197 		ret = radeon_process_aux_ch(chan,
198 					    tx_buf, tx_size, NULL, 0, delay, &ack);
199 		if (ret >= 0)
200 			/* Return payload size. */
201 			ret = msg->size;
202 		break;
203 	case DP_AUX_NATIVE_READ:
204 	case DP_AUX_I2C_READ:
205 		/* tx_size needs to be 4 even for bare address packets since the atom
206 		 * table needs the info in tx_buf[3].
207 		 */
208 		tx_size = HEADER_SIZE;
209 		if (msg->size == 0)
210 			tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
211 		else
212 			tx_buf[3] |= tx_size << 4;
213 		ret = radeon_process_aux_ch(chan,
214 					    tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
215 		break;
216 	default:
217 		ret = -EINVAL;
218 		break;
219 	}
220 
221 	if (ret >= 0)
222 		msg->reply = ack >> 4;
223 
224 	return ret;
225 }
226 
227 void radeon_dp_aux_init(struct radeon_connector *radeon_connector)
228 {
229 	struct drm_device *dev = radeon_connector->base.dev;
230 	struct radeon_device *rdev = dev->dev_private;
231 	int ret;
232 
233 	radeon_connector->ddc_bus->rec.hpd = radeon_connector->hpd.hpd;
234 	radeon_connector->ddc_bus->aux.dev = radeon_connector->base.kdev;
235 	radeon_connector->ddc_bus->aux.drm_dev = radeon_connector->base.dev;
236 	if (ASIC_IS_DCE5(rdev)) {
237 		if (radeon_auxch)
238 			radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_native;
239 		else
240 			radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_atom;
241 	} else {
242 		radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_atom;
243 	}
244 
245 	ret = drm_dp_aux_register(&radeon_connector->ddc_bus->aux);
246 	if (!ret)
247 		radeon_connector->ddc_bus->has_aux = true;
248 
249 	WARN(ret, "drm_dp_aux_register() failed with error %d\n", ret);
250 }
251 
252 /***** general DP utility functions *****/
253 
254 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_LEVEL_3
255 #define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPH_LEVEL_3
256 
257 static void dp_get_adjust_train(const u8 link_status[DP_LINK_STATUS_SIZE],
258 				int lane_count,
259 				u8 train_set[4])
260 {
261 	u8 v = 0;
262 	u8 p = 0;
263 	int lane;
264 
265 	for (lane = 0; lane < lane_count; lane++) {
266 		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
267 		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
268 
269 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
270 			  lane,
271 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
272 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
273 
274 		if (this_v > v)
275 			v = this_v;
276 		if (this_p > p)
277 			p = this_p;
278 	}
279 
280 	if (v >= DP_VOLTAGE_MAX)
281 		v |= DP_TRAIN_MAX_SWING_REACHED;
282 
283 	if (p >= DP_PRE_EMPHASIS_MAX)
284 		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
285 
286 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
287 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
288 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
289 
290 	for (lane = 0; lane < 4; lane++)
291 		train_set[lane] = v | p;
292 }
293 
294 /* convert bits per color to bits per pixel */
295 /* get bpc from the EDID */
296 static int convert_bpc_to_bpp(int bpc)
297 {
298 	if (bpc == 0)
299 		return 24;
300 	else
301 		return bpc * 3;
302 }
303 
304 /***** radeon specific DP functions *****/
305 
306 static int radeon_dp_get_dp_link_config(struct drm_connector *connector,
307 					const u8 dpcd[DP_DPCD_SIZE],
308 					unsigned pix_clock,
309 					unsigned *dp_lanes, unsigned *dp_rate)
310 {
311 	int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
312 	static const unsigned link_rates[3] = { 162000, 270000, 540000 };
313 	unsigned max_link_rate = drm_dp_max_link_rate(dpcd);
314 	unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
315 	unsigned lane_num, i, max_pix_clock;
316 
317 	if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) ==
318 	    ENCODER_OBJECT_ID_NUTMEG) {
319 		for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
320 			max_pix_clock = (lane_num * 270000 * 8) / bpp;
321 			if (max_pix_clock >= pix_clock) {
322 				*dp_lanes = lane_num;
323 				*dp_rate = 270000;
324 				return 0;
325 			}
326 		}
327 	} else {
328 		for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
329 			for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
330 				max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
331 				if (max_pix_clock >= pix_clock) {
332 					*dp_lanes = lane_num;
333 					*dp_rate = link_rates[i];
334 					return 0;
335 				}
336 			}
337 		}
338 	}
339 
340 	return -EINVAL;
341 }
342 
343 static u8 radeon_dp_encoder_service(struct radeon_device *rdev,
344 				    int action, int dp_clock,
345 				    u8 ucconfig, u8 lane_num)
346 {
347 	DP_ENCODER_SERVICE_PARAMETERS args;
348 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
349 
350 	memset(&args, 0, sizeof(args));
351 	args.ucLinkClock = dp_clock / 10;
352 	args.ucConfig = ucconfig;
353 	args.ucAction = action;
354 	args.ucLaneNum = lane_num;
355 	args.ucStatus = 0;
356 
357 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
358 	return args.ucStatus;
359 }
360 
361 u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
362 {
363 	struct drm_device *dev = radeon_connector->base.dev;
364 	struct radeon_device *rdev = dev->dev_private;
365 
366 	return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
367 					 radeon_connector->ddc_bus->rec.i2c_id, 0);
368 }
369 
370 static void radeon_dp_probe_oui(struct radeon_connector *radeon_connector)
371 {
372 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
373 	u8 buf[3];
374 
375 	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
376 		return;
377 
378 	if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3)
379 		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
380 			      buf[0], buf[1], buf[2]);
381 
382 	if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3)
383 		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
384 			      buf[0], buf[1], buf[2]);
385 }
386 
387 bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
388 {
389 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
390 	u8 msg[DP_DPCD_SIZE];
391 	int ret;
392 
393 	ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
394 			       DP_DPCD_SIZE);
395 	if (ret == DP_DPCD_SIZE) {
396 		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
397 
398 		DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
399 			      dig_connector->dpcd);
400 
401 		radeon_dp_probe_oui(radeon_connector);
402 
403 		return true;
404 	}
405 
406 	dig_connector->dpcd[0] = 0;
407 	return false;
408 }
409 
410 int radeon_dp_get_panel_mode(struct drm_encoder *encoder,
411 			     struct drm_connector *connector)
412 {
413 	struct drm_device *dev = encoder->dev;
414 	struct radeon_device *rdev = dev->dev_private;
415 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
416 	int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
417 	u16 dp_bridge = radeon_connector_encoder_get_dp_bridge_encoder_id(connector);
418 	u8 tmp;
419 
420 	if (!ASIC_IS_DCE4(rdev))
421 		return panel_mode;
422 
423 	if (!radeon_connector->con_priv)
424 		return panel_mode;
425 
426 	if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
427 		/* DP bridge chips */
428 		if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux,
429 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
430 			if (tmp & 1)
431 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
432 			else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
433 				 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
434 				panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
435 			else
436 				panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
437 		}
438 	} else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
439 		/* eDP */
440 		if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux,
441 				      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
442 			if (tmp & 1)
443 				panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
444 		}
445 	}
446 
447 	return panel_mode;
448 }
449 
450 void radeon_dp_set_link_config(struct drm_connector *connector,
451 			       const struct drm_display_mode *mode)
452 {
453 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
454 	struct radeon_connector_atom_dig *dig_connector;
455 	int ret;
456 
457 	if (!radeon_connector->con_priv)
458 		return;
459 	dig_connector = radeon_connector->con_priv;
460 
461 	if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
462 	    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
463 		ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd,
464 						   mode->clock,
465 						   &dig_connector->dp_lane_count,
466 						   &dig_connector->dp_clock);
467 		if (ret) {
468 			dig_connector->dp_clock = 0;
469 			dig_connector->dp_lane_count = 0;
470 		}
471 	}
472 }
473 
474 int radeon_dp_mode_valid_helper(struct drm_connector *connector,
475 				struct drm_display_mode *mode)
476 {
477 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
478 	struct radeon_connector_atom_dig *dig_connector;
479 	unsigned dp_clock, dp_lanes;
480 	int ret;
481 
482 	if ((mode->clock > 340000) &&
483 	    (!radeon_connector_is_dp12_capable(connector)))
484 		return MODE_CLOCK_HIGH;
485 
486 	if (!radeon_connector->con_priv)
487 		return MODE_CLOCK_HIGH;
488 	dig_connector = radeon_connector->con_priv;
489 
490 	ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd,
491 					   mode->clock,
492 					   &dp_lanes,
493 					   &dp_clock);
494 	if (ret)
495 		return MODE_CLOCK_HIGH;
496 
497 	if ((dp_clock == 540000) &&
498 	    (!radeon_connector_is_dp12_capable(connector)))
499 		return MODE_CLOCK_HIGH;
500 
501 	return MODE_OK;
502 }
503 
504 bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
505 {
506 	u8 link_status[DP_LINK_STATUS_SIZE];
507 	struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
508 
509 	if (drm_dp_dpcd_read_link_status(&radeon_connector->ddc_bus->aux, link_status)
510 	    <= 0)
511 		return false;
512 	if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
513 		return false;
514 	return true;
515 }
516 
517 void radeon_dp_set_rx_power_state(struct drm_connector *connector,
518 				  u8 power_state)
519 {
520 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
521 	struct radeon_connector_atom_dig *dig_connector;
522 
523 	if (!radeon_connector->con_priv)
524 		return;
525 
526 	dig_connector = radeon_connector->con_priv;
527 
528 	/* power up/down the sink */
529 	if (dig_connector->dpcd[0] >= 0x11) {
530 		drm_dp_dpcd_writeb(&radeon_connector->ddc_bus->aux,
531 				   DP_SET_POWER, power_state);
532 		usleep_range(1000, 2000);
533 	}
534 }
535 
536 
537 struct radeon_dp_link_train_info {
538 	struct radeon_device *rdev;
539 	struct drm_encoder *encoder;
540 	struct drm_connector *connector;
541 	int enc_id;
542 	int dp_clock;
543 	int dp_lane_count;
544 	bool tp3_supported;
545 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
546 	u8 train_set[4];
547 	u8 link_status[DP_LINK_STATUS_SIZE];
548 	u8 tries;
549 	bool use_dpencoder;
550 	struct drm_dp_aux *aux;
551 };
552 
553 static void radeon_dp_update_vs_emph(struct radeon_dp_link_train_info *dp_info)
554 {
555 	/* set the initial vs/emph on the source */
556 	atombios_dig_transmitter_setup(dp_info->encoder,
557 				       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
558 				       0, dp_info->train_set[0]); /* sets all lanes at once */
559 
560 	/* set the vs/emph on the sink */
561 	drm_dp_dpcd_write(dp_info->aux, DP_TRAINING_LANE0_SET,
562 			  dp_info->train_set, dp_info->dp_lane_count);
563 }
564 
565 static void radeon_dp_set_tp(struct radeon_dp_link_train_info *dp_info, int tp)
566 {
567 	int rtp = 0;
568 
569 	/* set training pattern on the source */
570 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder) {
571 		switch (tp) {
572 		case DP_TRAINING_PATTERN_1:
573 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
574 			break;
575 		case DP_TRAINING_PATTERN_2:
576 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
577 			break;
578 		case DP_TRAINING_PATTERN_3:
579 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
580 			break;
581 		}
582 		atombios_dig_encoder_setup(dp_info->encoder, rtp, 0);
583 	} else {
584 		switch (tp) {
585 		case DP_TRAINING_PATTERN_1:
586 			rtp = 0;
587 			break;
588 		case DP_TRAINING_PATTERN_2:
589 			rtp = 1;
590 			break;
591 		}
592 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
593 					  dp_info->dp_clock, dp_info->enc_id, rtp);
594 	}
595 
596 	/* enable training pattern on the sink */
597 	drm_dp_dpcd_writeb(dp_info->aux, DP_TRAINING_PATTERN_SET, tp);
598 }
599 
600 static int radeon_dp_link_train_init(struct radeon_dp_link_train_info *dp_info)
601 {
602 	struct radeon_encoder *radeon_encoder = to_radeon_encoder(dp_info->encoder);
603 	struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
604 	u8 tmp;
605 
606 	/* power up the sink */
607 	radeon_dp_set_rx_power_state(dp_info->connector, DP_SET_POWER_D0);
608 
609 	/* possibly enable downspread on the sink */
610 	if (dp_info->dpcd[3] & 0x1)
611 		drm_dp_dpcd_writeb(dp_info->aux,
612 				   DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
613 	else
614 		drm_dp_dpcd_writeb(dp_info->aux,
615 				   DP_DOWNSPREAD_CTRL, 0);
616 
617 	if (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)
618 		drm_dp_dpcd_writeb(dp_info->aux, DP_EDP_CONFIGURATION_SET, 1);
619 
620 	/* set the lane count on the sink */
621 	tmp = dp_info->dp_lane_count;
622 	if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
623 		tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
624 	drm_dp_dpcd_writeb(dp_info->aux, DP_LANE_COUNT_SET, tmp);
625 
626 	/* set the link rate on the sink */
627 	tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
628 	drm_dp_dpcd_writeb(dp_info->aux, DP_LINK_BW_SET, tmp);
629 
630 	/* start training on the source */
631 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
632 		atombios_dig_encoder_setup(dp_info->encoder,
633 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
634 	else
635 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_START,
636 					  dp_info->dp_clock, dp_info->enc_id, 0);
637 
638 	/* disable the training pattern on the sink */
639 	drm_dp_dpcd_writeb(dp_info->aux,
640 			   DP_TRAINING_PATTERN_SET,
641 			   DP_TRAINING_PATTERN_DISABLE);
642 
643 	return 0;
644 }
645 
646 static int radeon_dp_link_train_finish(struct radeon_dp_link_train_info *dp_info)
647 {
648 	udelay(400);
649 
650 	/* disable the training pattern on the sink */
651 	drm_dp_dpcd_writeb(dp_info->aux,
652 			   DP_TRAINING_PATTERN_SET,
653 			   DP_TRAINING_PATTERN_DISABLE);
654 
655 	/* disable the training pattern on the source */
656 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
657 		atombios_dig_encoder_setup(dp_info->encoder,
658 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
659 	else
660 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_COMPLETE,
661 					  dp_info->dp_clock, dp_info->enc_id, 0);
662 
663 	return 0;
664 }
665 
666 static int radeon_dp_link_train_cr(struct radeon_dp_link_train_info *dp_info)
667 {
668 	bool clock_recovery;
669  	u8 voltage;
670 	int i;
671 
672 	radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
673 	memset(dp_info->train_set, 0, 4);
674 	radeon_dp_update_vs_emph(dp_info);
675 
676 	udelay(400);
677 
678 	/* clock recovery loop */
679 	clock_recovery = false;
680 	dp_info->tries = 0;
681 	voltage = 0xff;
682 	while (1) {
683 		drm_dp_link_train_clock_recovery_delay(dp_info->aux, dp_info->dpcd);
684 
685 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
686 						 dp_info->link_status) <= 0) {
687 			DRM_ERROR("displayport link status failed\n");
688 			break;
689 		}
690 
691 		if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
692 			clock_recovery = true;
693 			break;
694 		}
695 
696 		for (i = 0; i < dp_info->dp_lane_count; i++) {
697 			if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
698 				break;
699 		}
700 		if (i == dp_info->dp_lane_count) {
701 			DRM_ERROR("clock recovery reached max voltage\n");
702 			break;
703 		}
704 
705 		if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
706 			++dp_info->tries;
707 			if (dp_info->tries == 5) {
708 				DRM_ERROR("clock recovery tried 5 times\n");
709 				break;
710 			}
711 		} else
712 			dp_info->tries = 0;
713 
714 		voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
715 
716 		/* Compute new train_set as requested by sink */
717 		dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);
718 
719 		radeon_dp_update_vs_emph(dp_info);
720 	}
721 	if (!clock_recovery) {
722 		DRM_ERROR("clock recovery failed\n");
723 		return -1;
724 	} else {
725 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
726 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
727 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
728 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
729 		return 0;
730 	}
731 }
732 
733 static int radeon_dp_link_train_ce(struct radeon_dp_link_train_info *dp_info)
734 {
735 	bool channel_eq;
736 
737 	if (dp_info->tp3_supported)
738 		radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
739 	else
740 		radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
741 
742 	/* channel equalization loop */
743 	dp_info->tries = 0;
744 	channel_eq = false;
745 	while (1) {
746 		drm_dp_link_train_channel_eq_delay(dp_info->aux, dp_info->dpcd);
747 
748 		if (drm_dp_dpcd_read_link_status(dp_info->aux,
749 						 dp_info->link_status) <= 0) {
750 			DRM_ERROR("displayport link status failed\n");
751 			break;
752 		}
753 
754 		if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
755 			channel_eq = true;
756 			break;
757 		}
758 
759 		/* Try 5 times */
760 		if (dp_info->tries > 5) {
761 			DRM_ERROR("channel eq failed: 5 tries\n");
762 			break;
763 		}
764 
765 		/* Compute new train_set as requested by sink */
766 		dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);
767 
768 		radeon_dp_update_vs_emph(dp_info);
769 		dp_info->tries++;
770 	}
771 
772 	if (!channel_eq) {
773 		DRM_ERROR("channel eq failed\n");
774 		return -1;
775 	} else {
776 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
777 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
778 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
779 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
780 		return 0;
781 	}
782 }
783 
784 void radeon_dp_link_train(struct drm_encoder *encoder,
785 			  struct drm_connector *connector)
786 {
787 	struct drm_device *dev = encoder->dev;
788 	struct radeon_device *rdev = dev->dev_private;
789 	struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
790 	struct radeon_encoder_atom_dig *dig;
791 	struct radeon_connector *radeon_connector;
792 	struct radeon_connector_atom_dig *dig_connector;
793 	struct radeon_dp_link_train_info dp_info;
794 	int index;
795 	u8 tmp, frev, crev;
796 
797 	if (!radeon_encoder->enc_priv)
798 		return;
799 	dig = radeon_encoder->enc_priv;
800 
801 	radeon_connector = to_radeon_connector(connector);
802 	if (!radeon_connector->con_priv)
803 		return;
804 	dig_connector = radeon_connector->con_priv;
805 
806 	if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
807 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
808 		return;
809 
810 	/* DPEncoderService newer than 1.1 can't program properly the
811 	 * training pattern. When facing such version use the
812 	 * DIGXEncoderControl (X== 1 | 2)
813 	 */
814 	dp_info.use_dpencoder = true;
815 	index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
816 	if (atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev)) {
817 		if (crev > 1)
818 			dp_info.use_dpencoder = false;
819 	}
820 
821 	dp_info.enc_id = 0;
822 	if (dig->dig_encoder)
823 		dp_info.enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;
824 	else
825 		dp_info.enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER;
826 	if (dig->linkb)
827 		dp_info.enc_id |= ATOM_DP_CONFIG_LINK_B;
828 	else
829 		dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A;
830 
831 	if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp)
832 	    == 1) {
833 		if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED))
834 			dp_info.tp3_supported = true;
835 		else
836 			dp_info.tp3_supported = false;
837 	} else {
838 		dp_info.tp3_supported = false;
839 	}
840 
841 	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
842 	dp_info.rdev = rdev;
843 	dp_info.encoder = encoder;
844 	dp_info.connector = connector;
845 	dp_info.dp_lane_count = dig_connector->dp_lane_count;
846 	dp_info.dp_clock = dig_connector->dp_clock;
847 	dp_info.aux = &radeon_connector->ddc_bus->aux;
848 
849 	if (radeon_dp_link_train_init(&dp_info))
850 		goto done;
851 	if (radeon_dp_link_train_cr(&dp_info))
852 		goto done;
853 	if (radeon_dp_link_train_ce(&dp_info))
854 		goto done;
855 done:
856 	if (radeon_dp_link_train_finish(&dp_info))
857 		return;
858 }
859