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/radeon_drm.h>
29 #include "radeon.h"
30 
31 #include "atom.h"
32 #include "atom-bits.h"
33 #include <drm/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
49  * so swap as appropriate when copying data to
50  * or from atom. Note that atom operates on
51  * dw units.
52  */
53 void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le)
54 {
55 #ifdef __BIG_ENDIAN
56 	u8 src_tmp[20], dst_tmp[20]; /* used for byteswapping */
57 	u32 *dst32, *src32;
58 	int i;
59 
60 	memcpy(src_tmp, src, num_bytes);
61 	src32 = (u32 *)src_tmp;
62 	dst32 = (u32 *)dst_tmp;
63 	if (to_le) {
64 		for (i = 0; i < ((num_bytes + 3) / 4); i++)
65 			dst32[i] = cpu_to_le32(src32[i]);
66 		memcpy(dst, dst_tmp, num_bytes);
67 	} else {
68 		u8 dws = num_bytes & ~3;
69 		for (i = 0; i < ((num_bytes + 3) / 4); i++)
70 			dst32[i] = le32_to_cpu(src32[i]);
71 		memcpy(dst, dst_tmp, dws);
72 		if (num_bytes % 4) {
73 			for (i = 0; i < (num_bytes % 4); i++)
74 				dst[dws+i] = dst_tmp[dws+i];
75 		}
76 	}
77 #else
78 	memcpy(dst, src, num_bytes);
79 #endif
80 }
81 
82 union aux_channel_transaction {
83 	PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
84 	PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
85 };
86 
87 static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
88 				 u8 *send, int send_bytes,
89 				 u8 *recv, int recv_size,
90 				 u8 delay, u8 *ack)
91 {
92 	struct drm_device *dev = chan->dev;
93 	struct radeon_device *rdev = dev->dev_private;
94 	union aux_channel_transaction args;
95 	int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
96 	unsigned char *base;
97 	int recv_bytes;
98 
99 	memset(&args, 0, sizeof(args));
100 
101 	base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
102 
103 	radeon_atom_copy_swap(base, send, send_bytes, true);
104 
105 	args.v1.lpAuxRequest = cpu_to_le16((u16)(0 + 4));
106 	args.v1.lpDataOut = cpu_to_le16((u16)(16 + 4));
107 	args.v1.ucDataOutLen = 0;
108 	args.v1.ucChannelID = chan->rec.i2c_id;
109 	args.v1.ucDelay = delay / 10;
110 	if (ASIC_IS_DCE4(rdev))
111 		args.v2.ucHPD_ID = chan->rec.hpd;
112 
113 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
114 
115 	*ack = args.v1.ucReplyStatus;
116 
117 	/* timeout */
118 	if (args.v1.ucReplyStatus == 1) {
119 		DRM_DEBUG_KMS("dp_aux_ch timeout\n");
120 		return -ETIMEDOUT;
121 	}
122 
123 	/* flags not zero */
124 	if (args.v1.ucReplyStatus == 2) {
125 		DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
126 		return -EBUSY;
127 	}
128 
129 	/* error */
130 	if (args.v1.ucReplyStatus == 3) {
131 		DRM_DEBUG_KMS("dp_aux_ch error\n");
132 		return -EIO;
133 	}
134 
135 	recv_bytes = args.v1.ucDataOutLen;
136 	if (recv_bytes > recv_size)
137 		recv_bytes = recv_size;
138 
139 	if (recv && recv_size)
140 		radeon_atom_copy_swap(recv, base + 16, recv_bytes, false);
141 
142 	return recv_bytes;
143 }
144 
145 static int radeon_dp_aux_native_write(struct radeon_connector *radeon_connector,
146 				      u16 address, u8 *send, u8 send_bytes, u8 delay)
147 {
148 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
149 	int ret;
150 	u8 msg[20];
151 	int msg_bytes = send_bytes + 4;
152 	u8 ack;
153 	unsigned retry;
154 
155 	if (send_bytes > 16)
156 		return -1;
157 
158 	msg[0] = address;
159 	msg[1] = address >> 8;
160 	msg[2] = AUX_NATIVE_WRITE << 4;
161 	msg[3] = (msg_bytes << 4) | (send_bytes - 1);
162 	memcpy(&msg[4], send, send_bytes);
163 
164 	for (retry = 0; retry < 4; retry++) {
165 		ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
166 					    msg, msg_bytes, NULL, 0, delay, &ack);
167 		if (ret == -EBUSY)
168 			continue;
169 		else if (ret < 0)
170 			return ret;
171 		if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
172 			return send_bytes;
173 		else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
174 			udelay(400);
175 		else
176 			return -EIO;
177 	}
178 
179 	return -EIO;
180 }
181 
182 static int radeon_dp_aux_native_read(struct radeon_connector *radeon_connector,
183 				     u16 address, u8 *recv, int recv_bytes, u8 delay)
184 {
185 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
186 	u8 msg[4];
187 	int msg_bytes = 4;
188 	u8 ack;
189 	int ret;
190 	unsigned retry;
191 
192 	msg[0] = address;
193 	msg[1] = address >> 8;
194 	msg[2] = AUX_NATIVE_READ << 4;
195 	msg[3] = (msg_bytes << 4) | (recv_bytes - 1);
196 
197 	for (retry = 0; retry < 4; retry++) {
198 		ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
199 					    msg, msg_bytes, recv, recv_bytes, delay, &ack);
200 		if (ret == -EBUSY)
201 			continue;
202 		else if (ret < 0)
203 			return ret;
204 		if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
205 			return ret;
206 		else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
207 			udelay(400);
208 		else if (ret == 0)
209 			return -EPROTO;
210 		else
211 			return -EIO;
212 	}
213 
214 	return -EIO;
215 }
216 
217 static void radeon_write_dpcd_reg(struct radeon_connector *radeon_connector,
218 				 u16 reg, u8 val)
219 {
220 	radeon_dp_aux_native_write(radeon_connector, reg, &val, 1, 0);
221 }
222 
223 static u8 radeon_read_dpcd_reg(struct radeon_connector *radeon_connector,
224 			       u16 reg)
225 {
226 	u8 val = 0;
227 
228 	radeon_dp_aux_native_read(radeon_connector, reg, &val, 1, 0);
229 
230 	return val;
231 }
232 
233 int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
234 			 u8 write_byte, u8 *read_byte)
235 {
236 	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
237 	struct radeon_i2c_chan *auxch = (struct radeon_i2c_chan *)adapter;
238 	u16 address = algo_data->address;
239 	u8 msg[5];
240 	u8 reply[2];
241 	unsigned retry;
242 	int msg_bytes;
243 	int reply_bytes = 1;
244 	int ret;
245 	u8 ack;
246 
247 	/* Set up the command byte */
248 	if (mode & MODE_I2C_READ)
249 		msg[2] = AUX_I2C_READ << 4;
250 	else
251 		msg[2] = AUX_I2C_WRITE << 4;
252 
253 	if (!(mode & MODE_I2C_STOP))
254 		msg[2] |= AUX_I2C_MOT << 4;
255 
256 	msg[0] = address;
257 	msg[1] = address >> 8;
258 
259 	switch (mode) {
260 	case MODE_I2C_WRITE:
261 		msg_bytes = 5;
262 		msg[3] = msg_bytes << 4;
263 		msg[4] = write_byte;
264 		break;
265 	case MODE_I2C_READ:
266 		msg_bytes = 4;
267 		msg[3] = msg_bytes << 4;
268 		break;
269 	default:
270 		msg_bytes = 4;
271 		msg[3] = 3 << 4;
272 		break;
273 	}
274 
275 	for (retry = 0; retry < 4; retry++) {
276 		ret = radeon_process_aux_ch(auxch,
277 					    msg, msg_bytes, reply, reply_bytes, 0, &ack);
278 		if (ret == -EBUSY)
279 			continue;
280 		else if (ret < 0) {
281 			DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
282 			return ret;
283 		}
284 
285 		switch (ack & AUX_NATIVE_REPLY_MASK) {
286 		case AUX_NATIVE_REPLY_ACK:
287 			/* I2C-over-AUX Reply field is only valid
288 			 * when paired with AUX ACK.
289 			 */
290 			break;
291 		case AUX_NATIVE_REPLY_NACK:
292 			DRM_DEBUG_KMS("aux_ch native nack\n");
293 			return -EREMOTEIO;
294 		case AUX_NATIVE_REPLY_DEFER:
295 			DRM_DEBUG_KMS("aux_ch native defer\n");
296 			udelay(400);
297 			continue;
298 		default:
299 			DRM_ERROR("aux_ch invalid native reply 0x%02x\n", ack);
300 			return -EREMOTEIO;
301 		}
302 
303 		switch (ack & AUX_I2C_REPLY_MASK) {
304 		case AUX_I2C_REPLY_ACK:
305 			if (mode == MODE_I2C_READ)
306 				*read_byte = reply[0];
307 			return ret;
308 		case AUX_I2C_REPLY_NACK:
309 			DRM_DEBUG_KMS("aux_i2c nack\n");
310 			return -EREMOTEIO;
311 		case AUX_I2C_REPLY_DEFER:
312 			DRM_DEBUG_KMS("aux_i2c defer\n");
313 			udelay(400);
314 			break;
315 		default:
316 			DRM_ERROR("aux_i2c invalid reply 0x%02x\n", ack);
317 			return -EREMOTEIO;
318 		}
319 	}
320 
321 	DRM_DEBUG_KMS("aux i2c too many retries, giving up\n");
322 	return -EREMOTEIO;
323 }
324 
325 /***** general DP utility functions *****/
326 
327 #define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_1200
328 #define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPHASIS_9_5
329 
330 static void dp_get_adjust_train(u8 link_status[DP_LINK_STATUS_SIZE],
331 				int lane_count,
332 				u8 train_set[4])
333 {
334 	u8 v = 0;
335 	u8 p = 0;
336 	int lane;
337 
338 	for (lane = 0; lane < lane_count; lane++) {
339 		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
340 		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
341 
342 		DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
343 			  lane,
344 			  voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
345 			  pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
346 
347 		if (this_v > v)
348 			v = this_v;
349 		if (this_p > p)
350 			p = this_p;
351 	}
352 
353 	if (v >= DP_VOLTAGE_MAX)
354 		v |= DP_TRAIN_MAX_SWING_REACHED;
355 
356 	if (p >= DP_PRE_EMPHASIS_MAX)
357 		p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
358 
359 	DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
360 		  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
361 		  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);
362 
363 	for (lane = 0; lane < 4; lane++)
364 		train_set[lane] = v | p;
365 }
366 
367 /* convert bits per color to bits per pixel */
368 /* get bpc from the EDID */
369 static int convert_bpc_to_bpp(int bpc)
370 {
371 	if (bpc == 0)
372 		return 24;
373 	else
374 		return bpc * 3;
375 }
376 
377 /* get the max pix clock supported by the link rate and lane num */
378 static int dp_get_max_dp_pix_clock(int link_rate,
379 				   int lane_num,
380 				   int bpp)
381 {
382 	return (link_rate * lane_num * 8) / bpp;
383 }
384 
385 /***** radeon specific DP functions *****/
386 
387 /* First get the min lane# when low rate is used according to pixel clock
388  * (prefer low rate), second check max lane# supported by DP panel,
389  * if the max lane# < low rate lane# then use max lane# instead.
390  */
391 static int radeon_dp_get_dp_lane_number(struct drm_connector *connector,
392 					u8 dpcd[DP_DPCD_SIZE],
393 					int pix_clock)
394 {
395 	int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
396 	int max_link_rate = drm_dp_max_link_rate(dpcd);
397 	int max_lane_num = drm_dp_max_lane_count(dpcd);
398 	int lane_num;
399 	int max_dp_pix_clock;
400 
401 	for (lane_num = 1; lane_num < max_lane_num; lane_num <<= 1) {
402 		max_dp_pix_clock = dp_get_max_dp_pix_clock(max_link_rate, lane_num, bpp);
403 		if (pix_clock <= max_dp_pix_clock)
404 			break;
405 	}
406 
407 	return lane_num;
408 }
409 
410 static int radeon_dp_get_dp_link_clock(struct drm_connector *connector,
411 				       u8 dpcd[DP_DPCD_SIZE],
412 				       int pix_clock)
413 {
414 	int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
415 	int lane_num, max_pix_clock;
416 
417 	if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) ==
418 	    ENCODER_OBJECT_ID_NUTMEG)
419 		return 270000;
420 
421 	lane_num = radeon_dp_get_dp_lane_number(connector, dpcd, pix_clock);
422 	max_pix_clock = dp_get_max_dp_pix_clock(162000, lane_num, bpp);
423 	if (pix_clock <= max_pix_clock)
424 		return 162000;
425 	max_pix_clock = dp_get_max_dp_pix_clock(270000, lane_num, bpp);
426 	if (pix_clock <= max_pix_clock)
427 		return 270000;
428 	if (radeon_connector_is_dp12_capable(connector)) {
429 		max_pix_clock = dp_get_max_dp_pix_clock(540000, lane_num, bpp);
430 		if (pix_clock <= max_pix_clock)
431 			return 540000;
432 	}
433 
434 	return drm_dp_max_link_rate(dpcd);
435 }
436 
437 static u8 radeon_dp_encoder_service(struct radeon_device *rdev,
438 				    int action, int dp_clock,
439 				    u8 ucconfig, u8 lane_num)
440 {
441 	DP_ENCODER_SERVICE_PARAMETERS args;
442 	int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
443 
444 	memset(&args, 0, sizeof(args));
445 	args.ucLinkClock = dp_clock / 10;
446 	args.ucConfig = ucconfig;
447 	args.ucAction = action;
448 	args.ucLaneNum = lane_num;
449 	args.ucStatus = 0;
450 
451 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
452 	return args.ucStatus;
453 }
454 
455 u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
456 {
457 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
458 	struct drm_device *dev = radeon_connector->base.dev;
459 	struct radeon_device *rdev = dev->dev_private;
460 
461 	return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
462 					 dig_connector->dp_i2c_bus->rec.i2c_id, 0);
463 }
464 
465 static void radeon_dp_probe_oui(struct radeon_connector *radeon_connector)
466 {
467 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
468 	u8 buf[3];
469 
470 	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
471 		return;
472 
473 	if (radeon_dp_aux_native_read(radeon_connector, DP_SINK_OUI, buf, 3, 0))
474 		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
475 			      buf[0], buf[1], buf[2]);
476 
477 	if (radeon_dp_aux_native_read(radeon_connector, DP_BRANCH_OUI, buf, 3, 0))
478 		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
479 			      buf[0], buf[1], buf[2]);
480 }
481 
482 bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
483 {
484 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
485 	u8 msg[DP_DPCD_SIZE];
486 	int ret, i;
487 
488 	ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, msg,
489 					DP_DPCD_SIZE, 0);
490 	if (ret > 0) {
491 		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
492 		DRM_DEBUG_KMS("DPCD: ");
493 		for (i = 0; i < DP_DPCD_SIZE; i++)
494 			DRM_DEBUG_KMS("%02x ", msg[i]);
495 		DRM_DEBUG_KMS("\n");
496 
497 		radeon_dp_probe_oui(radeon_connector);
498 
499 		return true;
500 	}
501 	dig_connector->dpcd[0] = 0;
502 	return false;
503 }
504 
505 int radeon_dp_get_panel_mode(struct drm_encoder *encoder,
506 			     struct drm_connector *connector)
507 {
508 	struct drm_device *dev = encoder->dev;
509 	struct radeon_device *rdev = dev->dev_private;
510 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
511 	int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
512 	u16 dp_bridge = radeon_connector_encoder_get_dp_bridge_encoder_id(connector);
513 	u8 tmp;
514 
515 	if (!ASIC_IS_DCE4(rdev))
516 		return panel_mode;
517 
518 	if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
519 		/* DP bridge chips */
520 		tmp = radeon_read_dpcd_reg(radeon_connector, DP_EDP_CONFIGURATION_CAP);
521 		if (tmp & 1)
522 			panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
523 		else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
524 			 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
525 			panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
526 		else
527 			panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
528 	} else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
529 		/* eDP */
530 		tmp = radeon_read_dpcd_reg(radeon_connector, DP_EDP_CONFIGURATION_CAP);
531 		if (tmp & 1)
532 			panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
533 	}
534 
535 	return panel_mode;
536 }
537 
538 void radeon_dp_set_link_config(struct drm_connector *connector,
539 			       const struct drm_display_mode *mode)
540 {
541 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
542 	struct radeon_connector_atom_dig *dig_connector;
543 
544 	if (!radeon_connector->con_priv)
545 		return;
546 	dig_connector = radeon_connector->con_priv;
547 
548 	if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
549 	    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
550 		dig_connector->dp_clock =
551 			radeon_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
552 		dig_connector->dp_lane_count =
553 			radeon_dp_get_dp_lane_number(connector, dig_connector->dpcd, mode->clock);
554 	}
555 }
556 
557 int radeon_dp_mode_valid_helper(struct drm_connector *connector,
558 				struct drm_display_mode *mode)
559 {
560 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
561 	struct radeon_connector_atom_dig *dig_connector;
562 	int dp_clock;
563 
564 	if (!radeon_connector->con_priv)
565 		return MODE_CLOCK_HIGH;
566 	dig_connector = radeon_connector->con_priv;
567 
568 	dp_clock =
569 		radeon_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock);
570 
571 	if ((dp_clock == 540000) &&
572 	    (!radeon_connector_is_dp12_capable(connector)))
573 		return MODE_CLOCK_HIGH;
574 
575 	return MODE_OK;
576 }
577 
578 static bool radeon_dp_get_link_status(struct radeon_connector *radeon_connector,
579 				      u8 link_status[DP_LINK_STATUS_SIZE])
580 {
581 	int ret;
582 	ret = radeon_dp_aux_native_read(radeon_connector, DP_LANE0_1_STATUS,
583 					link_status, DP_LINK_STATUS_SIZE, 100);
584 	if (ret <= 0) {
585 		return false;
586 	}
587 
588 	DRM_DEBUG_KMS("link status %6ph\n", link_status);
589 	return true;
590 }
591 
592 bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
593 {
594 	u8 link_status[DP_LINK_STATUS_SIZE];
595 	struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
596 
597 	if (!radeon_dp_get_link_status(radeon_connector, link_status))
598 		return false;
599 	if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
600 		return false;
601 	return true;
602 }
603 
604 struct radeon_dp_link_train_info {
605 	struct radeon_device *rdev;
606 	struct drm_encoder *encoder;
607 	struct drm_connector *connector;
608 	struct radeon_connector *radeon_connector;
609 	int enc_id;
610 	int dp_clock;
611 	int dp_lane_count;
612 	bool tp3_supported;
613 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
614 	u8 train_set[4];
615 	u8 link_status[DP_LINK_STATUS_SIZE];
616 	u8 tries;
617 	bool use_dpencoder;
618 };
619 
620 static void radeon_dp_update_vs_emph(struct radeon_dp_link_train_info *dp_info)
621 {
622 	/* set the initial vs/emph on the source */
623 	atombios_dig_transmitter_setup(dp_info->encoder,
624 				       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
625 				       0, dp_info->train_set[0]); /* sets all lanes at once */
626 
627 	/* set the vs/emph on the sink */
628 	radeon_dp_aux_native_write(dp_info->radeon_connector, DP_TRAINING_LANE0_SET,
629 				   dp_info->train_set, dp_info->dp_lane_count, 0);
630 }
631 
632 static void radeon_dp_set_tp(struct radeon_dp_link_train_info *dp_info, int tp)
633 {
634 	int rtp = 0;
635 
636 	/* set training pattern on the source */
637 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder) {
638 		switch (tp) {
639 		case DP_TRAINING_PATTERN_1:
640 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
641 			break;
642 		case DP_TRAINING_PATTERN_2:
643 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
644 			break;
645 		case DP_TRAINING_PATTERN_3:
646 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
647 			break;
648 		}
649 		atombios_dig_encoder_setup(dp_info->encoder, rtp, 0);
650 	} else {
651 		switch (tp) {
652 		case DP_TRAINING_PATTERN_1:
653 			rtp = 0;
654 			break;
655 		case DP_TRAINING_PATTERN_2:
656 			rtp = 1;
657 			break;
658 		}
659 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
660 					  dp_info->dp_clock, dp_info->enc_id, rtp);
661 	}
662 
663 	/* enable training pattern on the sink */
664 	radeon_write_dpcd_reg(dp_info->radeon_connector, DP_TRAINING_PATTERN_SET, tp);
665 }
666 
667 static int radeon_dp_link_train_init(struct radeon_dp_link_train_info *dp_info)
668 {
669 	struct radeon_encoder *radeon_encoder = to_radeon_encoder(dp_info->encoder);
670 	struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
671 	u8 tmp;
672 
673 	/* power up the sink */
674 	if (dp_info->dpcd[0] >= 0x11)
675 		radeon_write_dpcd_reg(dp_info->radeon_connector,
676 				      DP_SET_POWER, DP_SET_POWER_D0);
677 
678 	/* possibly enable downspread on the sink */
679 	if (dp_info->dpcd[3] & 0x1)
680 		radeon_write_dpcd_reg(dp_info->radeon_connector,
681 				      DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
682 	else
683 		radeon_write_dpcd_reg(dp_info->radeon_connector,
684 				      DP_DOWNSPREAD_CTRL, 0);
685 
686 	if ((dp_info->connector->connector_type == DRM_MODE_CONNECTOR_eDP) &&
687 	    (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)) {
688 		radeon_write_dpcd_reg(dp_info->radeon_connector, DP_EDP_CONFIGURATION_SET, 1);
689 	}
690 
691 	/* set the lane count on the sink */
692 	tmp = dp_info->dp_lane_count;
693 	if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
694 		tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
695 	radeon_write_dpcd_reg(dp_info->radeon_connector, DP_LANE_COUNT_SET, tmp);
696 
697 	/* set the link rate on the sink */
698 	tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
699 	radeon_write_dpcd_reg(dp_info->radeon_connector, DP_LINK_BW_SET, tmp);
700 
701 	/* start training on the source */
702 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
703 		atombios_dig_encoder_setup(dp_info->encoder,
704 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
705 	else
706 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_START,
707 					  dp_info->dp_clock, dp_info->enc_id, 0);
708 
709 	/* disable the training pattern on the sink */
710 	radeon_write_dpcd_reg(dp_info->radeon_connector,
711 			      DP_TRAINING_PATTERN_SET,
712 			      DP_TRAINING_PATTERN_DISABLE);
713 
714 	return 0;
715 }
716 
717 static int radeon_dp_link_train_finish(struct radeon_dp_link_train_info *dp_info)
718 {
719 	udelay(400);
720 
721 	/* disable the training pattern on the sink */
722 	radeon_write_dpcd_reg(dp_info->radeon_connector,
723 			      DP_TRAINING_PATTERN_SET,
724 			      DP_TRAINING_PATTERN_DISABLE);
725 
726 	/* disable the training pattern on the source */
727 	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
728 		atombios_dig_encoder_setup(dp_info->encoder,
729 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
730 	else
731 		radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_COMPLETE,
732 					  dp_info->dp_clock, dp_info->enc_id, 0);
733 
734 	return 0;
735 }
736 
737 static int radeon_dp_link_train_cr(struct radeon_dp_link_train_info *dp_info)
738 {
739 	bool clock_recovery;
740  	u8 voltage;
741 	int i;
742 
743 	radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
744 	memset(dp_info->train_set, 0, 4);
745 	radeon_dp_update_vs_emph(dp_info);
746 
747 	udelay(400);
748 
749 	/* clock recovery loop */
750 	clock_recovery = false;
751 	dp_info->tries = 0;
752 	voltage = 0xff;
753 	while (1) {
754 		drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);
755 
756 		if (!radeon_dp_get_link_status(dp_info->radeon_connector, dp_info->link_status)) {
757 			DRM_ERROR("displayport link status failed\n");
758 			break;
759 		}
760 
761 		if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
762 			clock_recovery = true;
763 			break;
764 		}
765 
766 		for (i = 0; i < dp_info->dp_lane_count; i++) {
767 			if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
768 				break;
769 		}
770 		if (i == dp_info->dp_lane_count) {
771 			DRM_ERROR("clock recovery reached max voltage\n");
772 			break;
773 		}
774 
775 		if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
776 			++dp_info->tries;
777 			if (dp_info->tries == 5) {
778 				DRM_ERROR("clock recovery tried 5 times\n");
779 				break;
780 			}
781 		} else
782 			dp_info->tries = 0;
783 
784 		voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
785 
786 		/* Compute new train_set as requested by sink */
787 		dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);
788 
789 		radeon_dp_update_vs_emph(dp_info);
790 	}
791 	if (!clock_recovery) {
792 		DRM_ERROR("clock recovery failed\n");
793 		return -1;
794 	} else {
795 		DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
796 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
797 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
798 			  DP_TRAIN_PRE_EMPHASIS_SHIFT);
799 		return 0;
800 	}
801 }
802 
803 static int radeon_dp_link_train_ce(struct radeon_dp_link_train_info *dp_info)
804 {
805 	bool channel_eq;
806 
807 	if (dp_info->tp3_supported)
808 		radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
809 	else
810 		radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);
811 
812 	/* channel equalization loop */
813 	dp_info->tries = 0;
814 	channel_eq = false;
815 	while (1) {
816 		drm_dp_link_train_channel_eq_delay(dp_info->dpcd);
817 
818 		if (!radeon_dp_get_link_status(dp_info->radeon_connector, dp_info->link_status)) {
819 			DRM_ERROR("displayport link status failed\n");
820 			break;
821 		}
822 
823 		if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
824 			channel_eq = true;
825 			break;
826 		}
827 
828 		/* Try 5 times */
829 		if (dp_info->tries > 5) {
830 			DRM_ERROR("channel eq failed: 5 tries\n");
831 			break;
832 		}
833 
834 		/* Compute new train_set as requested by sink */
835 		dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);
836 
837 		radeon_dp_update_vs_emph(dp_info);
838 		dp_info->tries++;
839 	}
840 
841 	if (!channel_eq) {
842 		DRM_ERROR("channel eq failed\n");
843 		return -1;
844 	} else {
845 		DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
846 			  dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
847 			  (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
848 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
849 		return 0;
850 	}
851 }
852 
853 void radeon_dp_link_train(struct drm_encoder *encoder,
854 			  struct drm_connector *connector)
855 {
856 	struct drm_device *dev = encoder->dev;
857 	struct radeon_device *rdev = dev->dev_private;
858 	struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
859 	struct radeon_encoder_atom_dig *dig;
860 	struct radeon_connector *radeon_connector;
861 	struct radeon_connector_atom_dig *dig_connector;
862 	struct radeon_dp_link_train_info dp_info;
863 	int index;
864 	u8 tmp, frev, crev;
865 
866 	if (!radeon_encoder->enc_priv)
867 		return;
868 	dig = radeon_encoder->enc_priv;
869 
870 	radeon_connector = to_radeon_connector(connector);
871 	if (!radeon_connector->con_priv)
872 		return;
873 	dig_connector = radeon_connector->con_priv;
874 
875 	if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
876 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
877 		return;
878 
879 	/* DPEncoderService newer than 1.1 can't program properly the
880 	 * training pattern. When facing such version use the
881 	 * DIGXEncoderControl (X== 1 | 2)
882 	 */
883 	dp_info.use_dpencoder = true;
884 	index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
885 	if (atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev)) {
886 		if (crev > 1) {
887 			dp_info.use_dpencoder = false;
888 		}
889 	}
890 
891 	dp_info.enc_id = 0;
892 	if (dig->dig_encoder)
893 		dp_info.enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;
894 	else
895 		dp_info.enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER;
896 	if (dig->linkb)
897 		dp_info.enc_id |= ATOM_DP_CONFIG_LINK_B;
898 	else
899 		dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A;
900 
901 	tmp = radeon_read_dpcd_reg(radeon_connector, DP_MAX_LANE_COUNT);
902 	if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED))
903 		dp_info.tp3_supported = true;
904 	else
905 		dp_info.tp3_supported = false;
906 
907 	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
908 	dp_info.rdev = rdev;
909 	dp_info.encoder = encoder;
910 	dp_info.connector = connector;
911 	dp_info.radeon_connector = radeon_connector;
912 	dp_info.dp_lane_count = dig_connector->dp_lane_count;
913 	dp_info.dp_clock = dig_connector->dp_clock;
914 
915 	if (radeon_dp_link_train_init(&dp_info))
916 		goto done;
917 	if (radeon_dp_link_train_cr(&dp_info))
918 		goto done;
919 	if (radeon_dp_link_train_ce(&dp_info))
920 		goto done;
921 done:
922 	if (radeon_dp_link_train_finish(&dp_info))
923 		return;
924 }
925