1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2012 Samsung Electronics
4  *
5  * Author: Donghwa Lee <dh09.lee@samsung.com>
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <common.h>
11 #include <display.h>
12 #include <fdtdec.h>
13 #include <linux/libfdt.h>
14 #include <malloc.h>
15 #include <video_bridge.h>
16 #include <linux/compat.h>
17 #include <linux/err.h>
18 #include <asm/arch/clk.h>
19 #include <asm/arch/cpu.h>
20 #include <asm/arch/dp_info.h>
21 #include <asm/arch/dp.h>
22 #include <asm/arch/pinmux.h>
23 #include <asm/arch/power.h>
24 
25 #include "exynos_dp_lowlevel.h"
26 
27 DECLARE_GLOBAL_DATA_PTR;
28 
29 static void exynos_dp_disp_info(struct edp_disp_info *disp_info)
30 {
31 	disp_info->h_total = disp_info->h_res + disp_info->h_sync_width +
32 		disp_info->h_back_porch + disp_info->h_front_porch;
33 	disp_info->v_total = disp_info->v_res + disp_info->v_sync_width +
34 		disp_info->v_back_porch + disp_info->v_front_porch;
35 
36 	return;
37 }
38 
39 static int exynos_dp_init_dp(struct exynos_dp *regs)
40 {
41 	int ret;
42 	exynos_dp_reset(regs);
43 
44 	/* SW defined function Normal operation */
45 	exynos_dp_enable_sw_func(regs, DP_ENABLE);
46 
47 	ret = exynos_dp_init_analog_func(regs);
48 	if (ret != EXYNOS_DP_SUCCESS)
49 		return ret;
50 
51 	exynos_dp_init_hpd(regs);
52 	exynos_dp_init_aux(regs);
53 
54 	return ret;
55 }
56 
57 static unsigned char exynos_dp_calc_edid_check_sum(unsigned char *edid_data)
58 {
59 	int i;
60 	unsigned char sum = 0;
61 
62 	for (i = 0; i < EDID_BLOCK_LENGTH; i++)
63 		sum = sum + edid_data[i];
64 
65 	return sum;
66 }
67 
68 static unsigned int exynos_dp_read_edid(struct exynos_dp *regs)
69 {
70 	unsigned char edid[EDID_BLOCK_LENGTH * 2];
71 	unsigned int extend_block = 0;
72 	unsigned char sum;
73 	unsigned char test_vector;
74 	int retval;
75 
76 	/*
77 	 * EDID device address is 0x50.
78 	 * However, if necessary, you must have set upper address
79 	 * into E-EDID in I2C device, 0x30.
80 	 */
81 
82 	/* Read Extension Flag, Number of 128-byte EDID extension blocks */
83 	exynos_dp_read_byte_from_i2c(regs, I2C_EDID_DEVICE_ADDR,
84 				     EDID_EXTENSION_FLAG, &extend_block);
85 
86 	if (extend_block > 0) {
87 		printf("DP EDID data includes a single extension!\n");
88 
89 		/* Read EDID data */
90 		retval = exynos_dp_read_bytes_from_i2c(regs,
91 						I2C_EDID_DEVICE_ADDR,
92 						EDID_HEADER_PATTERN,
93 						EDID_BLOCK_LENGTH,
94 						&edid[EDID_HEADER_PATTERN]);
95 		if (retval != 0) {
96 			printf("DP EDID Read failed!\n");
97 			return -1;
98 		}
99 		sum = exynos_dp_calc_edid_check_sum(edid);
100 		if (sum != 0) {
101 			printf("DP EDID bad checksum!\n");
102 			return -1;
103 		}
104 
105 		/* Read additional EDID data */
106 		retval = exynos_dp_read_bytes_from_i2c(regs,
107 				I2C_EDID_DEVICE_ADDR,
108 				EDID_BLOCK_LENGTH,
109 				EDID_BLOCK_LENGTH,
110 				&edid[EDID_BLOCK_LENGTH]);
111 		if (retval != 0) {
112 			printf("DP EDID Read failed!\n");
113 			return -1;
114 		}
115 		sum = exynos_dp_calc_edid_check_sum(&edid[EDID_BLOCK_LENGTH]);
116 		if (sum != 0) {
117 			printf("DP EDID bad checksum!\n");
118 			return -1;
119 		}
120 
121 		exynos_dp_read_byte_from_dpcd(regs, DPCD_TEST_REQUEST,
122 					      &test_vector);
123 		if (test_vector & DPCD_TEST_EDID_READ) {
124 			exynos_dp_write_byte_to_dpcd(regs,
125 				DPCD_TEST_EDID_CHECKSUM,
126 				edid[EDID_BLOCK_LENGTH + EDID_CHECKSUM]);
127 			exynos_dp_write_byte_to_dpcd(regs,
128 				DPCD_TEST_RESPONSE,
129 				DPCD_TEST_EDID_CHECKSUM_WRITE);
130 		}
131 	} else {
132 		debug("DP EDID data does not include any extensions.\n");
133 
134 		/* Read EDID data */
135 		retval = exynos_dp_read_bytes_from_i2c(regs,
136 				I2C_EDID_DEVICE_ADDR,
137 				EDID_HEADER_PATTERN,
138 				EDID_BLOCK_LENGTH,
139 				&edid[EDID_HEADER_PATTERN]);
140 
141 		if (retval != 0) {
142 			printf("DP EDID Read failed!\n");
143 			return -1;
144 		}
145 		sum = exynos_dp_calc_edid_check_sum(edid);
146 		if (sum != 0) {
147 			printf("DP EDID bad checksum!\n");
148 			return -1;
149 		}
150 
151 		exynos_dp_read_byte_from_dpcd(regs, DPCD_TEST_REQUEST,
152 			&test_vector);
153 		if (test_vector & DPCD_TEST_EDID_READ) {
154 			exynos_dp_write_byte_to_dpcd(regs,
155 				DPCD_TEST_EDID_CHECKSUM, edid[EDID_CHECKSUM]);
156 			exynos_dp_write_byte_to_dpcd(regs,
157 				DPCD_TEST_RESPONSE,
158 				DPCD_TEST_EDID_CHECKSUM_WRITE);
159 		}
160 	}
161 
162 	debug("DP EDID Read success!\n");
163 
164 	return 0;
165 }
166 
167 static unsigned int exynos_dp_handle_edid(struct exynos_dp *regs,
168 					  struct exynos_dp_priv *priv)
169 {
170 	unsigned char buf[12];
171 	unsigned int ret;
172 	unsigned char temp;
173 	unsigned char retry_cnt;
174 	unsigned char dpcd_rev[16];
175 	unsigned char lane_bw[16];
176 	unsigned char lane_cnt[16];
177 
178 	memset(dpcd_rev, 0, 16);
179 	memset(lane_bw, 0, 16);
180 	memset(lane_cnt, 0, 16);
181 	memset(buf, 0, 12);
182 
183 	retry_cnt = 5;
184 	while (retry_cnt) {
185 		/* Read DPCD 0x0000-0x000b */
186 		ret = exynos_dp_read_bytes_from_dpcd(regs, DPCD_DPCD_REV, 12,
187 						     buf);
188 		if (ret != EXYNOS_DP_SUCCESS) {
189 			if (retry_cnt == 0) {
190 				printf("DP read_byte_from_dpcd() failed\n");
191 				return ret;
192 			}
193 			retry_cnt--;
194 		} else
195 			break;
196 	}
197 
198 	/* */
199 	temp = buf[DPCD_DPCD_REV];
200 	if (temp == DP_DPCD_REV_10 || temp == DP_DPCD_REV_11)
201 		priv->dpcd_rev = temp;
202 	else {
203 		printf("DP Wrong DPCD Rev : %x\n", temp);
204 		return -ENODEV;
205 	}
206 
207 	temp = buf[DPCD_MAX_LINK_RATE];
208 	if (temp == DP_LANE_BW_1_62 || temp == DP_LANE_BW_2_70)
209 		priv->lane_bw = temp;
210 	else {
211 		printf("DP Wrong MAX LINK RATE : %x\n", temp);
212 		return -EINVAL;
213 	}
214 
215 	/* Refer VESA Display Port Standard Ver1.1a Page 120 */
216 	if (priv->dpcd_rev == DP_DPCD_REV_11) {
217 		temp = buf[DPCD_MAX_LANE_COUNT] & 0x1f;
218 		if (buf[DPCD_MAX_LANE_COUNT] & 0x80)
219 			priv->dpcd_efc = 1;
220 		else
221 			priv->dpcd_efc = 0;
222 	} else {
223 		temp = buf[DPCD_MAX_LANE_COUNT];
224 		priv->dpcd_efc = 0;
225 	}
226 
227 	if (temp == DP_LANE_CNT_1 || temp == DP_LANE_CNT_2 ||
228 			temp == DP_LANE_CNT_4) {
229 		priv->lane_cnt = temp;
230 	} else {
231 		printf("DP Wrong MAX LANE COUNT : %x\n", temp);
232 		return -EINVAL;
233 	}
234 
235 	ret = exynos_dp_read_edid(regs);
236 	if (ret != EXYNOS_DP_SUCCESS) {
237 		printf("DP exynos_dp_read_edid() failed\n");
238 		return -EINVAL;
239 	}
240 
241 	return ret;
242 }
243 
244 static void exynos_dp_init_training(struct exynos_dp *regs)
245 {
246 	/*
247 	 * MACRO_RST must be applied after the PLL_LOCK to avoid
248 	 * the DP inter pair skew issue for at least 10 us
249 	 */
250 	exynos_dp_reset_macro(regs);
251 
252 	/* All DP analog module power up */
253 	exynos_dp_set_analog_power_down(regs, POWER_ALL, 0);
254 }
255 
256 static unsigned int exynos_dp_link_start(struct exynos_dp *regs,
257 					 struct exynos_dp_priv *priv)
258 {
259 	unsigned char buf[5];
260 	unsigned int ret = 0;
261 
262 	debug("DP: %s was called\n", __func__);
263 
264 	priv->lt_info.lt_status = DP_LT_CR;
265 	priv->lt_info.ep_loop = 0;
266 	priv->lt_info.cr_loop[0] = 0;
267 	priv->lt_info.cr_loop[1] = 0;
268 	priv->lt_info.cr_loop[2] = 0;
269 	priv->lt_info.cr_loop[3] = 0;
270 
271 		/* Set sink to D0 (Sink Not Ready) mode. */
272 	ret = exynos_dp_write_byte_to_dpcd(regs, DPCD_SINK_POWER_STATE,
273 					   DPCD_SET_POWER_STATE_D0);
274 	if (ret != EXYNOS_DP_SUCCESS) {
275 		printf("DP write_dpcd_byte failed\n");
276 		return ret;
277 	}
278 
279 	/* Set link rate and count as you want to establish */
280 	exynos_dp_set_link_bandwidth(regs, priv->lane_bw);
281 	exynos_dp_set_lane_count(regs, priv->lane_cnt);
282 
283 	/* Setup RX configuration */
284 	buf[0] = priv->lane_bw;
285 	buf[1] = priv->lane_cnt;
286 
287 	ret = exynos_dp_write_bytes_to_dpcd(regs, DPCD_LINK_BW_SET, 2, buf);
288 	if (ret != EXYNOS_DP_SUCCESS) {
289 		printf("DP write_dpcd_byte failed\n");
290 		return ret;
291 	}
292 
293 	exynos_dp_set_lane_pre_emphasis(regs, PRE_EMPHASIS_LEVEL_0,
294 			priv->lane_cnt);
295 
296 	/* Set training pattern 1 */
297 	exynos_dp_set_training_pattern(regs, TRAINING_PTN1);
298 
299 	/* Set RX training pattern */
300 	buf[0] = DPCD_SCRAMBLING_DISABLED | DPCD_TRAINING_PATTERN_1;
301 
302 	buf[1] = DPCD_PRE_EMPHASIS_SET_PATTERN_2_LEVEL_0 |
303 		DPCD_VOLTAGE_SWING_SET_PATTERN_1_LEVEL_0;
304 	buf[2] = DPCD_PRE_EMPHASIS_SET_PATTERN_2_LEVEL_0 |
305 		DPCD_VOLTAGE_SWING_SET_PATTERN_1_LEVEL_0;
306 	buf[3] = DPCD_PRE_EMPHASIS_SET_PATTERN_2_LEVEL_0 |
307 		DPCD_VOLTAGE_SWING_SET_PATTERN_1_LEVEL_0;
308 	buf[4] = DPCD_PRE_EMPHASIS_SET_PATTERN_2_LEVEL_0 |
309 		DPCD_VOLTAGE_SWING_SET_PATTERN_1_LEVEL_0;
310 
311 	ret = exynos_dp_write_bytes_to_dpcd(regs, DPCD_TRAINING_PATTERN_SET,
312 					    5, buf);
313 	if (ret != EXYNOS_DP_SUCCESS) {
314 		printf("DP write_dpcd_byte failed\n");
315 		return ret;
316 	}
317 
318 	return ret;
319 }
320 
321 static unsigned int exynos_dp_training_pattern_dis(struct exynos_dp *regs)
322 {
323 	unsigned int ret;
324 
325 	exynos_dp_set_training_pattern(regs, DP_NONE);
326 
327 	ret = exynos_dp_write_byte_to_dpcd(regs, DPCD_TRAINING_PATTERN_SET,
328 					   DPCD_TRAINING_PATTERN_DISABLED);
329 	if (ret != EXYNOS_DP_SUCCESS) {
330 		printf("DP request_link_training_req failed\n");
331 		return -EAGAIN;
332 	}
333 
334 	return ret;
335 }
336 
337 static unsigned int exynos_dp_enable_rx_to_enhanced_mode(
338 		struct exynos_dp *regs, unsigned char enable)
339 {
340 	unsigned char data;
341 	unsigned int ret;
342 
343 	ret = exynos_dp_read_byte_from_dpcd(regs, DPCD_LANE_COUNT_SET,
344 					    &data);
345 	if (ret != EXYNOS_DP_SUCCESS) {
346 		printf("DP read_from_dpcd failed\n");
347 		return -EAGAIN;
348 	}
349 
350 	if (enable)
351 		data = DPCD_ENHANCED_FRAME_EN | DPCD_LN_COUNT_SET(data);
352 	else
353 		data = DPCD_LN_COUNT_SET(data);
354 
355 	ret = exynos_dp_write_byte_to_dpcd(regs, DPCD_LANE_COUNT_SET, data);
356 	if (ret != EXYNOS_DP_SUCCESS) {
357 			printf("DP write_to_dpcd failed\n");
358 			return -EAGAIN;
359 
360 	}
361 
362 	return ret;
363 }
364 
365 static unsigned int exynos_dp_set_enhanced_mode(struct exynos_dp *regs,
366 						unsigned char enhance_mode)
367 {
368 	unsigned int ret;
369 
370 	ret = exynos_dp_enable_rx_to_enhanced_mode(regs, enhance_mode);
371 	if (ret != EXYNOS_DP_SUCCESS) {
372 		printf("DP rx_enhance_mode failed\n");
373 		return -EAGAIN;
374 	}
375 
376 	exynos_dp_enable_enhanced_mode(regs, enhance_mode);
377 
378 	return ret;
379 }
380 
381 static int exynos_dp_read_dpcd_lane_stat(struct exynos_dp *regs,
382 					 struct exynos_dp_priv *priv,
383 					 unsigned char *status)
384 {
385 	unsigned int ret, i;
386 	unsigned char buf[2];
387 	unsigned char lane_stat[DP_LANE_CNT_4] = {0,};
388 	unsigned char shift_val[DP_LANE_CNT_4] = {0,};
389 
390 	shift_val[0] = 0;
391 	shift_val[1] = 4;
392 	shift_val[2] = 0;
393 	shift_val[3] = 4;
394 
395 	ret = exynos_dp_read_bytes_from_dpcd(regs, DPCD_LANE0_1_STATUS, 2,
396 					     buf);
397 	if (ret != EXYNOS_DP_SUCCESS) {
398 		printf("DP read lane status failed\n");
399 		return ret;
400 	}
401 
402 	for (i = 0; i < priv->lane_cnt; i++) {
403 		lane_stat[i] = (buf[(i / 2)] >> shift_val[i]) & 0x0f;
404 		if (lane_stat[0] != lane_stat[i]) {
405 			printf("Wrong lane status\n");
406 			return -EINVAL;
407 		}
408 	}
409 
410 	*status = lane_stat[0];
411 
412 	return ret;
413 }
414 
415 static unsigned int exynos_dp_read_dpcd_adj_req(struct exynos_dp *regs,
416 		unsigned char lane_num, unsigned char *sw, unsigned char *em)
417 {
418 	unsigned int ret;
419 	unsigned char buf;
420 	unsigned int dpcd_addr;
421 	unsigned char shift_val[DP_LANE_CNT_4] = {0, 4, 0, 4};
422 
423 	/* lane_num value is used as array index, so this range 0 ~ 3 */
424 	dpcd_addr = DPCD_ADJUST_REQUEST_LANE0_1 + (lane_num / 2);
425 
426 	ret = exynos_dp_read_byte_from_dpcd(regs, dpcd_addr, &buf);
427 	if (ret != EXYNOS_DP_SUCCESS) {
428 		printf("DP read adjust request failed\n");
429 		return -EAGAIN;
430 	}
431 
432 	*sw = ((buf >> shift_val[lane_num]) & 0x03);
433 	*em = ((buf >> shift_val[lane_num]) & 0x0c) >> 2;
434 
435 	return ret;
436 }
437 
438 static int exynos_dp_equalizer_err_link(struct exynos_dp *regs,
439 					struct exynos_dp_priv *priv)
440 {
441 	int ret;
442 
443 	ret = exynos_dp_training_pattern_dis(regs);
444 	if (ret != EXYNOS_DP_SUCCESS) {
445 		printf("DP training_pattern_disable() failed\n");
446 		priv->lt_info.lt_status = DP_LT_FAIL;
447 	}
448 
449 	ret = exynos_dp_set_enhanced_mode(regs, priv->dpcd_efc);
450 	if (ret != EXYNOS_DP_SUCCESS) {
451 		printf("DP set_enhanced_mode() failed\n");
452 		priv->lt_info.lt_status = DP_LT_FAIL;
453 	}
454 
455 	return ret;
456 }
457 
458 static int exynos_dp_reduce_link_rate(struct exynos_dp *regs,
459 				      struct exynos_dp_priv *priv)
460 {
461 	int ret;
462 
463 	if (priv->lane_bw == DP_LANE_BW_2_70) {
464 		priv->lane_bw = DP_LANE_BW_1_62;
465 		printf("DP Change lane bw to 1.62Gbps\n");
466 		priv->lt_info.lt_status = DP_LT_START;
467 		ret = EXYNOS_DP_SUCCESS;
468 	} else {
469 		ret = exynos_dp_training_pattern_dis(regs);
470 		if (ret != EXYNOS_DP_SUCCESS)
471 			printf("DP training_patter_disable() failed\n");
472 
473 		ret = exynos_dp_set_enhanced_mode(regs, priv->dpcd_efc);
474 		if (ret != EXYNOS_DP_SUCCESS)
475 			printf("DP set_enhanced_mode() failed\n");
476 
477 		priv->lt_info.lt_status = DP_LT_FAIL;
478 	}
479 
480 	return ret;
481 }
482 
483 static unsigned int exynos_dp_process_clock_recovery(struct exynos_dp *regs,
484 					struct exynos_dp_priv *priv)
485 {
486 	unsigned int ret;
487 	unsigned char lane_stat;
488 	unsigned char lt_ctl_val[DP_LANE_CNT_4] = {0, };
489 	unsigned int i;
490 	unsigned char adj_req_sw;
491 	unsigned char adj_req_em;
492 	unsigned char buf[5];
493 
494 	debug("DP: %s was called\n", __func__);
495 	mdelay(1);
496 
497 	ret = exynos_dp_read_dpcd_lane_stat(regs, priv, &lane_stat);
498 	if (ret != EXYNOS_DP_SUCCESS) {
499 			printf("DP read lane status failed\n");
500 			priv->lt_info.lt_status = DP_LT_FAIL;
501 			return ret;
502 	}
503 
504 	if (lane_stat & DP_LANE_STAT_CR_DONE) {
505 		debug("DP clock Recovery training succeed\n");
506 		exynos_dp_set_training_pattern(regs, TRAINING_PTN2);
507 
508 		for (i = 0; i < priv->lane_cnt; i++) {
509 			ret = exynos_dp_read_dpcd_adj_req(regs, i,
510 						&adj_req_sw, &adj_req_em);
511 			if (ret != EXYNOS_DP_SUCCESS) {
512 				priv->lt_info.lt_status = DP_LT_FAIL;
513 				return ret;
514 			}
515 
516 			lt_ctl_val[i] = 0;
517 			lt_ctl_val[i] = adj_req_em << 3 | adj_req_sw;
518 
519 			if ((adj_req_sw == VOLTAGE_LEVEL_3)
520 				|| (adj_req_em == PRE_EMPHASIS_LEVEL_3)) {
521 				lt_ctl_val[i] |= MAX_DRIVE_CURRENT_REACH_3 |
522 					MAX_PRE_EMPHASIS_REACH_3;
523 			}
524 			exynos_dp_set_lanex_pre_emphasis(regs,
525 							 lt_ctl_val[i], i);
526 		}
527 
528 		buf[0] =  DPCD_SCRAMBLING_DISABLED | DPCD_TRAINING_PATTERN_2;
529 		buf[1] = lt_ctl_val[0];
530 		buf[2] = lt_ctl_val[1];
531 		buf[3] = lt_ctl_val[2];
532 		buf[4] = lt_ctl_val[3];
533 
534 		ret = exynos_dp_write_bytes_to_dpcd(regs,
535 				DPCD_TRAINING_PATTERN_SET, 5, buf);
536 		if (ret != EXYNOS_DP_SUCCESS) {
537 			printf("DP write training pattern1 failed\n");
538 			priv->lt_info.lt_status = DP_LT_FAIL;
539 			return ret;
540 		} else
541 			priv->lt_info.lt_status = DP_LT_ET;
542 	} else {
543 		for (i = 0; i < priv->lane_cnt; i++) {
544 			lt_ctl_val[i] = exynos_dp_get_lanex_pre_emphasis(
545 						regs, i);
546 				ret = exynos_dp_read_dpcd_adj_req(regs, i,
547 						&adj_req_sw, &adj_req_em);
548 			if (ret != EXYNOS_DP_SUCCESS) {
549 				printf("DP read adj req failed\n");
550 				priv->lt_info.lt_status = DP_LT_FAIL;
551 				return ret;
552 			}
553 
554 			if ((adj_req_sw == VOLTAGE_LEVEL_3) ||
555 					(adj_req_em == PRE_EMPHASIS_LEVEL_3))
556 				ret = exynos_dp_reduce_link_rate(regs,
557 								 priv);
558 
559 			if ((DRIVE_CURRENT_SET_0_GET(lt_ctl_val[i]) ==
560 						adj_req_sw) &&
561 				(PRE_EMPHASIS_SET_0_GET(lt_ctl_val[i]) ==
562 						adj_req_em)) {
563 				priv->lt_info.cr_loop[i]++;
564 				if (priv->lt_info.cr_loop[i] == MAX_CR_LOOP)
565 					ret = exynos_dp_reduce_link_rate(
566 							regs, priv);
567 			}
568 
569 			lt_ctl_val[i] = 0;
570 			lt_ctl_val[i] = adj_req_em << 3 | adj_req_sw;
571 
572 			if ((adj_req_sw == VOLTAGE_LEVEL_3) ||
573 					(adj_req_em == PRE_EMPHASIS_LEVEL_3)) {
574 				lt_ctl_val[i] |= MAX_DRIVE_CURRENT_REACH_3 |
575 					MAX_PRE_EMPHASIS_REACH_3;
576 			}
577 			exynos_dp_set_lanex_pre_emphasis(regs,
578 							 lt_ctl_val[i], i);
579 		}
580 
581 		ret = exynos_dp_write_bytes_to_dpcd(regs,
582 				DPCD_TRAINING_LANE0_SET, 4, lt_ctl_val);
583 		if (ret != EXYNOS_DP_SUCCESS) {
584 			printf("DP write training pattern2 failed\n");
585 			priv->lt_info.lt_status = DP_LT_FAIL;
586 			return ret;
587 		}
588 	}
589 
590 	return ret;
591 }
592 
593 static unsigned int exynos_dp_process_equalizer_training(
594 		struct exynos_dp *regs, struct exynos_dp_priv *priv)
595 {
596 	unsigned int ret;
597 	unsigned char lane_stat, adj_req_sw, adj_req_em, i;
598 	unsigned char lt_ctl_val[DP_LANE_CNT_4] = {0,};
599 	unsigned char interlane_aligned = 0;
600 	unsigned char f_bw;
601 	unsigned char f_lane_cnt;
602 	unsigned char sink_stat;
603 
604 	mdelay(1);
605 
606 	ret = exynos_dp_read_dpcd_lane_stat(regs, priv, &lane_stat);
607 	if (ret != EXYNOS_DP_SUCCESS) {
608 		printf("DP read lane status failed\n");
609 		priv->lt_info.lt_status = DP_LT_FAIL;
610 		return ret;
611 	}
612 
613 	debug("DP lane stat : %x\n", lane_stat);
614 
615 	if (lane_stat & DP_LANE_STAT_CR_DONE) {
616 		ret = exynos_dp_read_byte_from_dpcd(regs,
617 						    DPCD_LN_ALIGN_UPDATED,
618 						    &sink_stat);
619 		if (ret != EXYNOS_DP_SUCCESS) {
620 			priv->lt_info.lt_status = DP_LT_FAIL;
621 
622 			return ret;
623 		}
624 
625 		interlane_aligned = (sink_stat & DPCD_INTERLANE_ALIGN_DONE);
626 
627 		for (i = 0; i < priv->lane_cnt; i++) {
628 			ret = exynos_dp_read_dpcd_adj_req(regs, i,
629 					&adj_req_sw, &adj_req_em);
630 			if (ret != EXYNOS_DP_SUCCESS) {
631 				printf("DP read adj req 1 failed\n");
632 				priv->lt_info.lt_status = DP_LT_FAIL;
633 
634 				return ret;
635 			}
636 
637 			lt_ctl_val[i] = 0;
638 			lt_ctl_val[i] = adj_req_em << 3 | adj_req_sw;
639 
640 			if ((adj_req_sw == VOLTAGE_LEVEL_3) ||
641 				(adj_req_em == PRE_EMPHASIS_LEVEL_3)) {
642 				lt_ctl_val[i] |= MAX_DRIVE_CURRENT_REACH_3;
643 				lt_ctl_val[i] |= MAX_PRE_EMPHASIS_REACH_3;
644 			}
645 		}
646 
647 		if (((lane_stat&DP_LANE_STAT_CE_DONE) &&
648 			(lane_stat&DP_LANE_STAT_SYM_LOCK))
649 			&& (interlane_aligned == DPCD_INTERLANE_ALIGN_DONE)) {
650 			debug("DP Equalizer training succeed\n");
651 
652 			f_bw = exynos_dp_get_link_bandwidth(regs);
653 			f_lane_cnt = exynos_dp_get_lane_count(regs);
654 
655 			debug("DP final BandWidth : %x\n", f_bw);
656 			debug("DP final Lane Count : %x\n", f_lane_cnt);
657 
658 			priv->lt_info.lt_status = DP_LT_FINISHED;
659 
660 			exynos_dp_equalizer_err_link(regs, priv);
661 
662 		} else {
663 			priv->lt_info.ep_loop++;
664 
665 			if (priv->lt_info.ep_loop > MAX_EQ_LOOP) {
666 				if (priv->lane_bw == DP_LANE_BW_2_70) {
667 					ret = exynos_dp_reduce_link_rate(
668 							regs, priv);
669 				} else {
670 					priv->lt_info.lt_status =
671 								DP_LT_FAIL;
672 					exynos_dp_equalizer_err_link(regs,
673 								     priv);
674 				}
675 			} else {
676 				for (i = 0; i < priv->lane_cnt; i++)
677 					exynos_dp_set_lanex_pre_emphasis(
678 						regs, lt_ctl_val[i], i);
679 
680 				ret = exynos_dp_write_bytes_to_dpcd(regs,
681 						DPCD_TRAINING_LANE0_SET,
682 						4, lt_ctl_val);
683 				if (ret != EXYNOS_DP_SUCCESS) {
684 					printf("DP set lt pattern failed\n");
685 					priv->lt_info.lt_status =
686 								DP_LT_FAIL;
687 					exynos_dp_equalizer_err_link(regs,
688 								     priv);
689 				}
690 			}
691 		}
692 	} else if (priv->lane_bw == DP_LANE_BW_2_70) {
693 		ret = exynos_dp_reduce_link_rate(regs, priv);
694 	} else {
695 		priv->lt_info.lt_status = DP_LT_FAIL;
696 		exynos_dp_equalizer_err_link(regs, priv);
697 	}
698 
699 	return ret;
700 }
701 
702 static unsigned int exynos_dp_sw_link_training(struct exynos_dp *regs,
703 					       struct exynos_dp_priv *priv)
704 {
705 	unsigned int ret = 0;
706 	int training_finished;
707 
708 	/* Turn off unnecessary lane */
709 	if (priv->lane_cnt == 1)
710 		exynos_dp_set_analog_power_down(regs, CH1_BLOCK, 1);
711 
712 	training_finished = 0;
713 
714 	priv->lt_info.lt_status = DP_LT_START;
715 
716 	/* Process here */
717 	while (!training_finished) {
718 		switch (priv->lt_info.lt_status) {
719 		case DP_LT_START:
720 			ret = exynos_dp_link_start(regs, priv);
721 			if (ret != EXYNOS_DP_SUCCESS) {
722 				printf("DP LT:link start failed\n");
723 				return ret;
724 			}
725 			break;
726 		case DP_LT_CR:
727 			ret = exynos_dp_process_clock_recovery(regs,
728 							       priv);
729 			if (ret != EXYNOS_DP_SUCCESS) {
730 				printf("DP LT:clock recovery failed\n");
731 				return ret;
732 			}
733 			break;
734 		case DP_LT_ET:
735 			ret = exynos_dp_process_equalizer_training(regs,
736 								   priv);
737 			if (ret != EXYNOS_DP_SUCCESS) {
738 				printf("DP LT:equalizer training failed\n");
739 				return ret;
740 			}
741 			break;
742 		case DP_LT_FINISHED:
743 			training_finished = 1;
744 			break;
745 		case DP_LT_FAIL:
746 			return -1;
747 		}
748 	}
749 
750 	return ret;
751 }
752 
753 static unsigned int exynos_dp_set_link_train(struct exynos_dp *regs,
754 					     struct exynos_dp_priv *priv)
755 {
756 	unsigned int ret;
757 
758 	exynos_dp_init_training(regs);
759 
760 	ret = exynos_dp_sw_link_training(regs, priv);
761 	if (ret != EXYNOS_DP_SUCCESS)
762 		printf("DP dp_sw_link_training() failed\n");
763 
764 	return ret;
765 }
766 
767 static void exynos_dp_enable_scramble(struct exynos_dp *regs,
768 				      unsigned int enable)
769 {
770 	unsigned char data;
771 
772 	if (enable) {
773 		exynos_dp_enable_scrambling(regs, DP_ENABLE);
774 
775 		exynos_dp_read_byte_from_dpcd(regs,
776 					      DPCD_TRAINING_PATTERN_SET, &data);
777 		exynos_dp_write_byte_to_dpcd(regs, DPCD_TRAINING_PATTERN_SET,
778 			(u8)(data & ~DPCD_SCRAMBLING_DISABLED));
779 	} else {
780 		exynos_dp_enable_scrambling(regs, DP_DISABLE);
781 		exynos_dp_read_byte_from_dpcd(regs,
782 					      DPCD_TRAINING_PATTERN_SET, &data);
783 		exynos_dp_write_byte_to_dpcd(regs, DPCD_TRAINING_PATTERN_SET,
784 			(u8)(data | DPCD_SCRAMBLING_DISABLED));
785 	}
786 }
787 
788 static unsigned int exynos_dp_config_video(struct exynos_dp *regs,
789 					   struct exynos_dp_priv *priv)
790 {
791 	unsigned int ret = 0;
792 	unsigned int retry_cnt;
793 
794 	mdelay(1);
795 
796 	if (priv->video_info.master_mode) {
797 		printf("DP does not support master mode\n");
798 		return -ENODEV;
799 	} else {
800 		/* debug slave */
801 		exynos_dp_config_video_slave_mode(regs,
802 						  &priv->video_info);
803 	}
804 
805 	exynos_dp_set_video_color_format(regs, &priv->video_info);
806 
807 	if (priv->video_info.bist_mode) {
808 		if (exynos_dp_config_video_bist(regs, priv) != 0)
809 			return -1;
810 	}
811 
812 	ret = exynos_dp_get_pll_lock_status(regs);
813 	if (ret != PLL_LOCKED) {
814 		printf("DP PLL is not locked yet\n");
815 		return -EIO;
816 	}
817 
818 	if (priv->video_info.master_mode == 0) {
819 		retry_cnt = 10;
820 		while (retry_cnt) {
821 			ret = exynos_dp_is_slave_video_stream_clock_on(regs);
822 			if (ret != EXYNOS_DP_SUCCESS) {
823 				if (retry_cnt == 0) {
824 					printf("DP stream_clock_on failed\n");
825 					return ret;
826 				}
827 				retry_cnt--;
828 				mdelay(1);
829 			} else
830 				break;
831 		}
832 	}
833 
834 	/* Set to use the register calculated M/N video */
835 	exynos_dp_set_video_cr_mn(regs, CALCULATED_M, 0, 0);
836 
837 	/* For video bist, Video timing must be generated by register */
838 	exynos_dp_set_video_timing_mode(regs, VIDEO_TIMING_FROM_CAPTURE);
839 
840 	/* Enable video bist */
841 	if (priv->video_info.bist_pattern != COLOR_RAMP &&
842 		priv->video_info.bist_pattern != BALCK_WHITE_V_LINES &&
843 		priv->video_info.bist_pattern != COLOR_SQUARE)
844 		exynos_dp_enable_video_bist(regs,
845 					    priv->video_info.bist_mode);
846 	else
847 		exynos_dp_enable_video_bist(regs, DP_DISABLE);
848 
849 	/* Disable video mute */
850 	exynos_dp_enable_video_mute(regs, DP_DISABLE);
851 
852 	/* Configure video Master or Slave mode */
853 	exynos_dp_enable_video_master(regs,
854 				      priv->video_info.master_mode);
855 
856 	/* Enable video */
857 	exynos_dp_start_video(regs);
858 
859 	if (priv->video_info.master_mode == 0) {
860 		retry_cnt = 100;
861 		while (retry_cnt) {
862 			ret = exynos_dp_is_video_stream_on(regs);
863 			if (ret != EXYNOS_DP_SUCCESS) {
864 				if (retry_cnt == 0) {
865 					printf("DP Timeout of video stream\n");
866 					return ret;
867 				}
868 				retry_cnt--;
869 				mdelay(5);
870 			} else
871 				break;
872 		}
873 	}
874 
875 	return ret;
876 }
877 
878 static int exynos_dp_ofdata_to_platdata(struct udevice *dev)
879 {
880 	struct exynos_dp_priv *priv = dev_get_priv(dev);
881 	const void *blob = gd->fdt_blob;
882 	unsigned int node = dev_of_offset(dev);
883 	fdt_addr_t addr;
884 
885 	addr = devfdt_get_addr(dev);
886 	if (addr == FDT_ADDR_T_NONE) {
887 		debug("Can't get the DP base address\n");
888 		return -EINVAL;
889 	}
890 	priv->regs = (struct exynos_dp *)addr;
891 	priv->disp_info.h_res = fdtdec_get_int(blob, node,
892 							"samsung,h-res", 0);
893 	priv->disp_info.h_sync_width = fdtdec_get_int(blob, node,
894 						"samsung,h-sync-width", 0);
895 	priv->disp_info.h_back_porch = fdtdec_get_int(blob, node,
896 						"samsung,h-back-porch", 0);
897 	priv->disp_info.h_front_porch = fdtdec_get_int(blob, node,
898 						"samsung,h-front-porch", 0);
899 	priv->disp_info.v_res = fdtdec_get_int(blob, node,
900 						"samsung,v-res", 0);
901 	priv->disp_info.v_sync_width = fdtdec_get_int(blob, node,
902 						"samsung,v-sync-width", 0);
903 	priv->disp_info.v_back_porch = fdtdec_get_int(blob, node,
904 						"samsung,v-back-porch", 0);
905 	priv->disp_info.v_front_porch = fdtdec_get_int(blob, node,
906 						"samsung,v-front-porch", 0);
907 	priv->disp_info.v_sync_rate = fdtdec_get_int(blob, node,
908 						"samsung,v-sync-rate", 0);
909 
910 	priv->lt_info.lt_status = fdtdec_get_int(blob, node,
911 						"samsung,lt-status", 0);
912 
913 	priv->video_info.master_mode = fdtdec_get_int(blob, node,
914 						"samsung,master-mode", 0);
915 	priv->video_info.bist_mode = fdtdec_get_int(blob, node,
916 						"samsung,bist-mode", 0);
917 	priv->video_info.bist_pattern = fdtdec_get_int(blob, node,
918 						"samsung,bist-pattern", 0);
919 	priv->video_info.h_sync_polarity = fdtdec_get_int(blob, node,
920 						"samsung,h-sync-polarity", 0);
921 	priv->video_info.v_sync_polarity = fdtdec_get_int(blob, node,
922 						"samsung,v-sync-polarity", 0);
923 	priv->video_info.interlaced = fdtdec_get_int(blob, node,
924 						"samsung,interlaced", 0);
925 	priv->video_info.color_space = fdtdec_get_int(blob, node,
926 						"samsung,color-space", 0);
927 	priv->video_info.dynamic_range = fdtdec_get_int(blob, node,
928 						"samsung,dynamic-range", 0);
929 	priv->video_info.ycbcr_coeff = fdtdec_get_int(blob, node,
930 						"samsung,ycbcr-coeff", 0);
931 	priv->video_info.color_depth = fdtdec_get_int(blob, node,
932 						"samsung,color-depth", 0);
933 	return 0;
934 }
935 
936 static int exynos_dp_bridge_init(struct udevice *dev)
937 {
938 	const int max_tries = 10;
939 	int num_tries;
940 	int ret;
941 
942 	debug("%s\n", __func__);
943 	ret = video_bridge_attach(dev);
944 	if (ret) {
945 		debug("video bridge init failed: %d\n", ret);
946 		return ret;
947 	}
948 
949 	/*
950 	 * We need to wait for 90ms after bringing up the bridge since there
951 	 * is a phantom "high" on the HPD chip during its bootup.  The phantom
952 	 * high comes within 7ms of de-asserting PD and persists for at least
953 	 * 15ms.  The real high comes roughly 50ms after PD is de-asserted. The
954 	 * phantom high makes it hard for us to know when the NXP chip is up.
955 	 */
956 	mdelay(90);
957 
958 	for (num_tries = 0; num_tries < max_tries; num_tries++) {
959 		/* Check HPD. If it's high, or we don't have it, all is well */
960 		ret = video_bridge_check_attached(dev);
961 		if (!ret || ret == -ENOENT)
962 			return 0;
963 
964 		debug("%s: eDP bridge failed to come up; try %d of %d\n",
965 		      __func__, num_tries, max_tries);
966 	}
967 
968 	/* Immediately go into bridge reset if the hp line is not high */
969 	return -EIO;
970 }
971 
972 static int exynos_dp_bridge_setup(const void *blob)
973 {
974 	const int max_tries = 2;
975 	int num_tries;
976 	struct udevice *dev;
977 	int ret;
978 
979 	/* Configure I2C registers for Parade bridge */
980 	ret = uclass_get_device(UCLASS_VIDEO_BRIDGE, 0, &dev);
981 	if (ret) {
982 		debug("video bridge init failed: %d\n", ret);
983 		return ret;
984 	}
985 
986 	if (strncmp(dev->driver->name, "parade", 6)) {
987 		/* Mux HPHPD to the special hotplug detect mode */
988 		exynos_pinmux_config(PERIPH_ID_DPHPD, 0);
989 	}
990 
991 	for (num_tries = 0; num_tries < max_tries; num_tries++) {
992 		ret = exynos_dp_bridge_init(dev);
993 		if (!ret)
994 			return 0;
995 		if (num_tries == max_tries - 1)
996 			break;
997 
998 		/*
999 		* If we're here, the bridge chip failed to initialise.
1000 		* Power down the bridge in an attempt to reset.
1001 		*/
1002 		video_bridge_set_active(dev, false);
1003 
1004 		/*
1005 		* Arbitrarily wait 300ms here with DP_N low.  Don't know for
1006 		* sure how long we should wait, but we're being paranoid.
1007 		*/
1008 		mdelay(300);
1009 	}
1010 
1011 	return ret;
1012 }
1013 int exynos_dp_enable(struct udevice *dev, int panel_bpp,
1014 		     const struct display_timing *timing)
1015 {
1016 	struct exynos_dp_priv *priv = dev_get_priv(dev);
1017 	struct exynos_dp *regs = priv->regs;
1018 	unsigned int ret;
1019 
1020 	debug("%s: start\n", __func__);
1021 	exynos_dp_disp_info(&priv->disp_info);
1022 
1023 	ret = exynos_dp_bridge_setup(gd->fdt_blob);
1024 	if (ret && ret != -ENODEV)
1025 		printf("LCD bridge failed to enable: %d\n", ret);
1026 
1027 	exynos_dp_phy_ctrl(1);
1028 
1029 	ret = exynos_dp_init_dp(regs);
1030 	if (ret != EXYNOS_DP_SUCCESS) {
1031 		printf("DP exynos_dp_init_dp() failed\n");
1032 		return ret;
1033 	}
1034 
1035 	ret = exynos_dp_handle_edid(regs, priv);
1036 	if (ret != EXYNOS_DP_SUCCESS) {
1037 		printf("EDP handle_edid fail\n");
1038 		return ret;
1039 	}
1040 
1041 	ret = exynos_dp_set_link_train(regs, priv);
1042 	if (ret != EXYNOS_DP_SUCCESS) {
1043 		printf("DP link training fail\n");
1044 		return ret;
1045 	}
1046 
1047 	exynos_dp_enable_scramble(regs, DP_ENABLE);
1048 	exynos_dp_enable_rx_to_enhanced_mode(regs, DP_ENABLE);
1049 	exynos_dp_enable_enhanced_mode(regs, DP_ENABLE);
1050 
1051 	exynos_dp_set_link_bandwidth(regs, priv->lane_bw);
1052 	exynos_dp_set_lane_count(regs, priv->lane_cnt);
1053 
1054 	exynos_dp_init_video(regs);
1055 	ret = exynos_dp_config_video(regs, priv);
1056 	if (ret != EXYNOS_DP_SUCCESS) {
1057 		printf("Exynos DP init failed\n");
1058 		return ret;
1059 	}
1060 
1061 	debug("Exynos DP init done\n");
1062 
1063 	return ret;
1064 }
1065 
1066 
1067 static const struct dm_display_ops exynos_dp_ops = {
1068 	.enable = exynos_dp_enable,
1069 };
1070 
1071 static const struct udevice_id exynos_dp_ids[] = {
1072 	{ .compatible = "samsung,exynos5-dp" },
1073 	{ }
1074 };
1075 
1076 U_BOOT_DRIVER(exynos_dp) = {
1077 	.name	= "exynos_dp",
1078 	.id	= UCLASS_DISPLAY,
1079 	.of_match = exynos_dp_ids,
1080 	.ops	= &exynos_dp_ops,
1081 	.ofdata_to_platdata	= exynos_dp_ofdata_to_platdata,
1082 	.priv_auto_alloc_size	= sizeof(struct exynos_dp_priv),
1083 };
1084