1 /*
2 * Analogix DP (Display Port) core interface driver.
3 *
4 * Copyright (C) 2012 Samsung Electronics Co., Ltd.
5 * Author: Jingoo Han <jg1.han@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 */
12 
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/err.h>
16 #include <linux/clk.h>
17 #include <linux/io.h>
18 #include <linux/iopoll.h>
19 #include <linux/interrupt.h>
20 #include <linux/of.h>
21 #include <linux/of_gpio.h>
22 #include <linux/gpio.h>
23 #include <linux/component.h>
24 #include <linux/phy/phy.h>
25 
26 #include <drm/drmP.h>
27 #include <drm/drm_atomic_helper.h>
28 #include <drm/drm_crtc.h>
29 #include <drm/drm_crtc_helper.h>
30 #include <drm/drm_panel.h>
31 
32 #include <drm/bridge/analogix_dp.h>
33 
34 #include "analogix_dp_core.h"
35 #include "analogix_dp_reg.h"
36 
37 #define to_dp(nm)	container_of(nm, struct analogix_dp_device, nm)
38 
39 static const bool verify_fast_training;
40 
41 struct bridge_init {
42 	struct i2c_client *client;
43 	struct device_node *node;
44 };
45 
46 static void analogix_dp_init_dp(struct analogix_dp_device *dp)
47 {
48 	analogix_dp_reset(dp);
49 
50 	analogix_dp_swreset(dp);
51 
52 	analogix_dp_init_analog_param(dp);
53 	analogix_dp_init_interrupt(dp);
54 
55 	/* SW defined function Normal operation */
56 	analogix_dp_enable_sw_function(dp);
57 
58 	analogix_dp_config_interrupt(dp);
59 	analogix_dp_init_analog_func(dp);
60 
61 	analogix_dp_init_hpd(dp);
62 	analogix_dp_init_aux(dp);
63 }
64 
65 static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
66 {
67 	int timeout_loop = 0;
68 
69 	while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
70 		if (analogix_dp_get_plug_in_status(dp) == 0)
71 			return 0;
72 
73 		timeout_loop++;
74 		usleep_range(10, 11);
75 	}
76 
77 	/*
78 	 * Some edp screen do not have hpd signal, so we can't just
79 	 * return failed when hpd plug in detect failed, DT property
80 	 * "force-hpd" would indicate whether driver need this.
81 	 */
82 	if (!dp->force_hpd)
83 		return -ETIMEDOUT;
84 
85 	/*
86 	 * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
87 	 * will not work, so we need to give a force hpd action to
88 	 * set HPD_STATUS manually.
89 	 */
90 	dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
91 
92 	analogix_dp_force_hpd(dp);
93 
94 	if (analogix_dp_get_plug_in_status(dp) != 0) {
95 		dev_err(dp->dev, "failed to get hpd plug in status\n");
96 		return -EINVAL;
97 	}
98 
99 	dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
100 
101 	return 0;
102 }
103 
104 int analogix_dp_psr_enabled(struct analogix_dp_device *dp)
105 {
106 
107 	return dp->psr_enable;
108 }
109 EXPORT_SYMBOL_GPL(analogix_dp_psr_enabled);
110 
111 int analogix_dp_enable_psr(struct analogix_dp_device *dp)
112 {
113 	struct edp_vsc_psr psr_vsc;
114 
115 	if (!dp->psr_enable)
116 		return 0;
117 
118 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
119 	memset(&psr_vsc, 0, sizeof(psr_vsc));
120 	psr_vsc.sdp_header.HB0 = 0;
121 	psr_vsc.sdp_header.HB1 = 0x7;
122 	psr_vsc.sdp_header.HB2 = 0x2;
123 	psr_vsc.sdp_header.HB3 = 0x8;
124 
125 	psr_vsc.DB0 = 0;
126 	psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
127 
128 	return analogix_dp_send_psr_spd(dp, &psr_vsc, true);
129 }
130 EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
131 
132 int analogix_dp_disable_psr(struct analogix_dp_device *dp)
133 {
134 	struct edp_vsc_psr psr_vsc;
135 	int ret;
136 
137 	if (!dp->psr_enable)
138 		return 0;
139 
140 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
141 	memset(&psr_vsc, 0, sizeof(psr_vsc));
142 	psr_vsc.sdp_header.HB0 = 0;
143 	psr_vsc.sdp_header.HB1 = 0x7;
144 	psr_vsc.sdp_header.HB2 = 0x2;
145 	psr_vsc.sdp_header.HB3 = 0x8;
146 
147 	psr_vsc.DB0 = 0;
148 	psr_vsc.DB1 = 0;
149 
150 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
151 	if (ret != 1)
152 		dev_err(dp->dev, "Failed to set DP Power0 %d\n", ret);
153 
154 	return analogix_dp_send_psr_spd(dp, &psr_vsc, false);
155 }
156 EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
157 
158 static bool analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
159 {
160 	unsigned char psr_version;
161 
162 	drm_dp_dpcd_readb(&dp->aux, DP_PSR_SUPPORT, &psr_version);
163 	dev_dbg(dp->dev, "Panel PSR version : %x\n", psr_version);
164 
165 	return (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
166 }
167 
168 static void analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
169 {
170 	unsigned char psr_en;
171 
172 	/* Disable psr function */
173 	drm_dp_dpcd_readb(&dp->aux, DP_PSR_EN_CFG, &psr_en);
174 	psr_en &= ~DP_PSR_ENABLE;
175 	drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
176 
177 	/* Main-Link transmitter remains active during PSR active states */
178 	psr_en = DP_PSR_MAIN_LINK_ACTIVE | DP_PSR_CRC_VERIFICATION;
179 	drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
180 
181 	/* Enable psr function */
182 	psr_en = DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE |
183 		 DP_PSR_CRC_VERIFICATION;
184 	drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
185 
186 	analogix_dp_enable_psr_crc(dp);
187 }
188 
189 static void
190 analogix_dp_enable_rx_to_enhanced_mode(struct analogix_dp_device *dp,
191 				       bool enable)
192 {
193 	u8 data;
194 
195 	drm_dp_dpcd_readb(&dp->aux, DP_LANE_COUNT_SET, &data);
196 
197 	if (enable)
198 		drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
199 				   DP_LANE_COUNT_ENHANCED_FRAME_EN |
200 					DPCD_LANE_COUNT_SET(data));
201 	else
202 		drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
203 				   DPCD_LANE_COUNT_SET(data));
204 }
205 
206 static int analogix_dp_is_enhanced_mode_available(struct analogix_dp_device *dp)
207 {
208 	u8 data;
209 	int retval;
210 
211 	drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
212 	retval = DPCD_ENHANCED_FRAME_CAP(data);
213 
214 	return retval;
215 }
216 
217 static void analogix_dp_set_enhanced_mode(struct analogix_dp_device *dp)
218 {
219 	u8 data;
220 
221 	data = analogix_dp_is_enhanced_mode_available(dp);
222 	analogix_dp_enable_rx_to_enhanced_mode(dp, data);
223 	analogix_dp_enable_enhanced_mode(dp, data);
224 }
225 
226 static void analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
227 {
228 	analogix_dp_set_training_pattern(dp, DP_NONE);
229 
230 	drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
231 			   DP_TRAINING_PATTERN_DISABLE);
232 }
233 
234 static void
235 analogix_dp_set_lane_lane_pre_emphasis(struct analogix_dp_device *dp,
236 				       int pre_emphasis, int lane)
237 {
238 	switch (lane) {
239 	case 0:
240 		analogix_dp_set_lane0_pre_emphasis(dp, pre_emphasis);
241 		break;
242 	case 1:
243 		analogix_dp_set_lane1_pre_emphasis(dp, pre_emphasis);
244 		break;
245 
246 	case 2:
247 		analogix_dp_set_lane2_pre_emphasis(dp, pre_emphasis);
248 		break;
249 
250 	case 3:
251 		analogix_dp_set_lane3_pre_emphasis(dp, pre_emphasis);
252 		break;
253 	}
254 }
255 
256 static int analogix_dp_link_start(struct analogix_dp_device *dp)
257 {
258 	u8 buf[4];
259 	int lane, lane_count, pll_tries, retval;
260 
261 	lane_count = dp->link_train.lane_count;
262 
263 	dp->link_train.lt_state = CLOCK_RECOVERY;
264 	dp->link_train.eq_loop = 0;
265 
266 	for (lane = 0; lane < lane_count; lane++)
267 		dp->link_train.cr_loop[lane] = 0;
268 
269 	/* Set link rate and count as you want to establish*/
270 	analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
271 	analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
272 
273 	/* Setup RX configuration */
274 	buf[0] = dp->link_train.link_rate;
275 	buf[1] = dp->link_train.lane_count;
276 	retval = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, 2);
277 	if (retval < 0)
278 		return retval;
279 
280 	/* Set TX pre-emphasis to minimum */
281 	for (lane = 0; lane < lane_count; lane++)
282 		analogix_dp_set_lane_lane_pre_emphasis(dp,
283 			PRE_EMPHASIS_LEVEL_0, lane);
284 
285 	/* Wait for PLL lock */
286 	pll_tries = 0;
287 	while (analogix_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) {
288 		if (pll_tries == DP_TIMEOUT_LOOP_COUNT) {
289 			dev_err(dp->dev, "Wait for PLL lock timed out\n");
290 			return -ETIMEDOUT;
291 		}
292 
293 		pll_tries++;
294 		usleep_range(90, 120);
295 	}
296 
297 	/* Set training pattern 1 */
298 	analogix_dp_set_training_pattern(dp, TRAINING_PTN1);
299 
300 	/* Set RX training pattern */
301 	retval = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
302 				    DP_LINK_SCRAMBLING_DISABLE |
303 					DP_TRAINING_PATTERN_1);
304 	if (retval < 0)
305 		return retval;
306 
307 	for (lane = 0; lane < lane_count; lane++)
308 		buf[lane] = DP_TRAIN_PRE_EMPH_LEVEL_0 |
309 			    DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
310 
311 	retval = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, buf,
312 				   lane_count);
313 	if (retval < 0)
314 		return retval;
315 
316 	return 0;
317 }
318 
319 static unsigned char analogix_dp_get_lane_status(u8 link_status[2], int lane)
320 {
321 	int shift = (lane & 1) * 4;
322 	u8 link_value = link_status[lane >> 1];
323 
324 	return (link_value >> shift) & 0xf;
325 }
326 
327 static int analogix_dp_clock_recovery_ok(u8 link_status[2], int lane_count)
328 {
329 	int lane;
330 	u8 lane_status;
331 
332 	for (lane = 0; lane < lane_count; lane++) {
333 		lane_status = analogix_dp_get_lane_status(link_status, lane);
334 		if ((lane_status & DP_LANE_CR_DONE) == 0)
335 			return -EINVAL;
336 	}
337 	return 0;
338 }
339 
340 static int analogix_dp_channel_eq_ok(u8 link_status[2], u8 link_align,
341 				     int lane_count)
342 {
343 	int lane;
344 	u8 lane_status;
345 
346 	if ((link_align & DP_INTERLANE_ALIGN_DONE) == 0)
347 		return -EINVAL;
348 
349 	for (lane = 0; lane < lane_count; lane++) {
350 		lane_status = analogix_dp_get_lane_status(link_status, lane);
351 		lane_status &= DP_CHANNEL_EQ_BITS;
352 		if (lane_status != DP_CHANNEL_EQ_BITS)
353 			return -EINVAL;
354 	}
355 
356 	return 0;
357 }
358 
359 static unsigned char
360 analogix_dp_get_adjust_request_voltage(u8 adjust_request[2], int lane)
361 {
362 	int shift = (lane & 1) * 4;
363 	u8 link_value = adjust_request[lane >> 1];
364 
365 	return (link_value >> shift) & 0x3;
366 }
367 
368 static unsigned char analogix_dp_get_adjust_request_pre_emphasis(
369 					u8 adjust_request[2],
370 					int lane)
371 {
372 	int shift = (lane & 1) * 4;
373 	u8 link_value = adjust_request[lane >> 1];
374 
375 	return ((link_value >> shift) & 0xc) >> 2;
376 }
377 
378 static void analogix_dp_set_lane_link_training(struct analogix_dp_device *dp,
379 					       u8 training_lane_set, int lane)
380 {
381 	switch (lane) {
382 	case 0:
383 		analogix_dp_set_lane0_link_training(dp, training_lane_set);
384 		break;
385 	case 1:
386 		analogix_dp_set_lane1_link_training(dp, training_lane_set);
387 		break;
388 
389 	case 2:
390 		analogix_dp_set_lane2_link_training(dp, training_lane_set);
391 		break;
392 
393 	case 3:
394 		analogix_dp_set_lane3_link_training(dp, training_lane_set);
395 		break;
396 	}
397 }
398 
399 static unsigned int
400 analogix_dp_get_lane_link_training(struct analogix_dp_device *dp,
401 				   int lane)
402 {
403 	u32 reg;
404 
405 	switch (lane) {
406 	case 0:
407 		reg = analogix_dp_get_lane0_link_training(dp);
408 		break;
409 	case 1:
410 		reg = analogix_dp_get_lane1_link_training(dp);
411 		break;
412 	case 2:
413 		reg = analogix_dp_get_lane2_link_training(dp);
414 		break;
415 	case 3:
416 		reg = analogix_dp_get_lane3_link_training(dp);
417 		break;
418 	default:
419 		WARN_ON(1);
420 		return 0;
421 	}
422 
423 	return reg;
424 }
425 
426 static void analogix_dp_reduce_link_rate(struct analogix_dp_device *dp)
427 {
428 	analogix_dp_training_pattern_dis(dp);
429 	analogix_dp_set_enhanced_mode(dp);
430 
431 	dp->link_train.lt_state = FAILED;
432 }
433 
434 static void analogix_dp_get_adjust_training_lane(struct analogix_dp_device *dp,
435 						 u8 adjust_request[2])
436 {
437 	int lane, lane_count;
438 	u8 voltage_swing, pre_emphasis, training_lane;
439 
440 	lane_count = dp->link_train.lane_count;
441 	for (lane = 0; lane < lane_count; lane++) {
442 		voltage_swing = analogix_dp_get_adjust_request_voltage(
443 						adjust_request, lane);
444 		pre_emphasis = analogix_dp_get_adjust_request_pre_emphasis(
445 						adjust_request, lane);
446 		training_lane = DPCD_VOLTAGE_SWING_SET(voltage_swing) |
447 				DPCD_PRE_EMPHASIS_SET(pre_emphasis);
448 
449 		if (voltage_swing == VOLTAGE_LEVEL_3)
450 			training_lane |= DP_TRAIN_MAX_SWING_REACHED;
451 		if (pre_emphasis == PRE_EMPHASIS_LEVEL_3)
452 			training_lane |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
453 
454 		dp->link_train.training_lane[lane] = training_lane;
455 	}
456 }
457 
458 static int analogix_dp_process_clock_recovery(struct analogix_dp_device *dp)
459 {
460 	int lane, lane_count, retval;
461 	u8 voltage_swing, pre_emphasis, training_lane;
462 	u8 link_status[2], adjust_request[2];
463 
464 	usleep_range(100, 101);
465 
466 	lane_count = dp->link_train.lane_count;
467 
468 	retval = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status, 2);
469 	if (retval < 0)
470 		return retval;
471 
472 	retval = drm_dp_dpcd_read(&dp->aux, DP_ADJUST_REQUEST_LANE0_1,
473 				  adjust_request, 2);
474 	if (retval < 0)
475 		return retval;
476 
477 	if (analogix_dp_clock_recovery_ok(link_status, lane_count) == 0) {
478 		/* set training pattern 2 for EQ */
479 		analogix_dp_set_training_pattern(dp, TRAINING_PTN2);
480 
481 		retval = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
482 					    DP_LINK_SCRAMBLING_DISABLE |
483 						DP_TRAINING_PATTERN_2);
484 		if (retval < 0)
485 			return retval;
486 
487 		dev_info(dp->dev, "Link Training Clock Recovery success\n");
488 		dp->link_train.lt_state = EQUALIZER_TRAINING;
489 	} else {
490 		for (lane = 0; lane < lane_count; lane++) {
491 			training_lane = analogix_dp_get_lane_link_training(
492 							dp, lane);
493 			voltage_swing = analogix_dp_get_adjust_request_voltage(
494 							adjust_request, lane);
495 			pre_emphasis = analogix_dp_get_adjust_request_pre_emphasis(
496 							adjust_request, lane);
497 
498 			if (DPCD_VOLTAGE_SWING_GET(training_lane) ==
499 					voltage_swing &&
500 			    DPCD_PRE_EMPHASIS_GET(training_lane) ==
501 					pre_emphasis)
502 				dp->link_train.cr_loop[lane]++;
503 
504 			if (dp->link_train.cr_loop[lane] == MAX_CR_LOOP ||
505 			    voltage_swing == VOLTAGE_LEVEL_3 ||
506 			    pre_emphasis == PRE_EMPHASIS_LEVEL_3) {
507 				dev_err(dp->dev, "CR Max reached (%d,%d,%d)\n",
508 					dp->link_train.cr_loop[lane],
509 					voltage_swing, pre_emphasis);
510 				analogix_dp_reduce_link_rate(dp);
511 				return -EIO;
512 			}
513 		}
514 	}
515 
516 	analogix_dp_get_adjust_training_lane(dp, adjust_request);
517 
518 	for (lane = 0; lane < lane_count; lane++)
519 		analogix_dp_set_lane_link_training(dp,
520 			dp->link_train.training_lane[lane], lane);
521 
522 	retval = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
523 				   dp->link_train.training_lane, lane_count);
524 	if (retval < 0)
525 		return retval;
526 
527 	return 0;
528 }
529 
530 static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
531 {
532 	int lane, lane_count, retval;
533 	u32 reg;
534 	u8 link_align, link_status[2], adjust_request[2], spread;
535 
536 	usleep_range(400, 401);
537 
538 	lane_count = dp->link_train.lane_count;
539 
540 	retval = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status, 2);
541 	if (retval < 0)
542 		return retval;
543 
544 	if (analogix_dp_clock_recovery_ok(link_status, lane_count)) {
545 		analogix_dp_reduce_link_rate(dp);
546 		return -EIO;
547 	}
548 
549 	retval = drm_dp_dpcd_read(&dp->aux, DP_ADJUST_REQUEST_LANE0_1,
550 				  adjust_request, 2);
551 	if (retval < 0)
552 		return retval;
553 
554 	retval = drm_dp_dpcd_readb(&dp->aux, DP_LANE_ALIGN_STATUS_UPDATED,
555 				   &link_align);
556 	if (retval < 0)
557 		return retval;
558 
559 	analogix_dp_get_adjust_training_lane(dp, adjust_request);
560 
561 	if (!analogix_dp_channel_eq_ok(link_status, link_align, lane_count)) {
562 		/* traing pattern Set to Normal */
563 		analogix_dp_training_pattern_dis(dp);
564 
565 		dev_info(dp->dev, "Link Training success!\n");
566 
567 		analogix_dp_get_link_bandwidth(dp, &reg);
568 		dp->link_train.link_rate = reg;
569 		dev_dbg(dp->dev, "final bandwidth = %.2x\n",
570 			dp->link_train.link_rate);
571 
572 		analogix_dp_get_lane_count(dp, &reg);
573 		dp->link_train.lane_count = reg;
574 		dev_dbg(dp->dev, "final lane count = %.2x\n",
575 			dp->link_train.lane_count);
576 
577 		retval = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD,
578 					   &spread);
579 		if (retval != 1) {
580 			dev_err(dp->dev, "failed to read downspread %d\n",
581 				retval);
582 			dp->fast_train_support = false;
583 		} else {
584 			dp->fast_train_support =
585 				(spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING) ?
586 					true : false;
587 		}
588 		dev_dbg(dp->dev, "fast link training %s\n",
589 			dp->fast_train_support ? "supported" : "unsupported");
590 
591 		/* set enhanced mode if available */
592 		analogix_dp_set_enhanced_mode(dp);
593 		dp->link_train.lt_state = FINISHED;
594 
595 		return 0;
596 	}
597 
598 	/* not all locked */
599 	dp->link_train.eq_loop++;
600 
601 	if (dp->link_train.eq_loop > MAX_EQ_LOOP) {
602 		dev_err(dp->dev, "EQ Max loop\n");
603 		analogix_dp_reduce_link_rate(dp);
604 		return -EIO;
605 	}
606 
607 	for (lane = 0; lane < lane_count; lane++)
608 		analogix_dp_set_lane_link_training(dp,
609 			dp->link_train.training_lane[lane], lane);
610 
611 	retval = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
612 				   dp->link_train.training_lane, lane_count);
613 	if (retval < 0)
614 		return retval;
615 
616 	return 0;
617 }
618 
619 static void analogix_dp_get_max_rx_bandwidth(struct analogix_dp_device *dp,
620 					     u8 *bandwidth)
621 {
622 	u8 data;
623 
624 	/*
625 	 * For DP rev.1.1, Maximum link rate of Main Link lanes
626 	 * 0x06 = 1.62 Gbps, 0x0a = 2.7 Gbps
627 	 * For DP rev.1.2, Maximum link rate of Main Link lanes
628 	 * 0x06 = 1.62 Gbps, 0x0a = 2.7 Gbps, 0x14 = 5.4Gbps
629 	 */
630 	drm_dp_dpcd_readb(&dp->aux, DP_MAX_LINK_RATE, &data);
631 	*bandwidth = data;
632 }
633 
634 static void analogix_dp_get_max_rx_lane_count(struct analogix_dp_device *dp,
635 					      u8 *lane_count)
636 {
637 	u8 data;
638 
639 	/*
640 	 * For DP rev.1.1, Maximum number of Main Link lanes
641 	 * 0x01 = 1 lane, 0x02 = 2 lanes, 0x04 = 4 lanes
642 	 */
643 	drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
644 	*lane_count = DPCD_MAX_LANE_COUNT(data);
645 }
646 
647 static int analogix_dp_full_link_train(struct analogix_dp_device *dp,
648 				       u32 max_lanes, u32 max_rate)
649 {
650 	int retval = 0;
651 	bool training_finished = false;
652 
653 	/*
654 	 * MACRO_RST must be applied after the PLL_LOCK to avoid
655 	 * the DP inter pair skew issue for at least 10 us
656 	 */
657 	analogix_dp_reset_macro(dp);
658 
659 	/* Initialize by reading RX's DPCD */
660 	analogix_dp_get_max_rx_bandwidth(dp, &dp->link_train.link_rate);
661 	analogix_dp_get_max_rx_lane_count(dp, &dp->link_train.lane_count);
662 
663 	if ((dp->link_train.link_rate != DP_LINK_BW_1_62) &&
664 	    (dp->link_train.link_rate != DP_LINK_BW_2_7) &&
665 	    (dp->link_train.link_rate != DP_LINK_BW_5_4)) {
666 		dev_err(dp->dev, "Rx Max Link Rate is abnormal :%x !\n",
667 			dp->link_train.link_rate);
668 		dp->link_train.link_rate = DP_LINK_BW_1_62;
669 	}
670 
671 	if (dp->link_train.lane_count == 0) {
672 		dev_err(dp->dev, "Rx Max Lane count is abnormal :%x !\n",
673 			dp->link_train.lane_count);
674 		dp->link_train.lane_count = (u8)LANE_COUNT1;
675 	}
676 
677 	/* Setup TX lane count & rate */
678 	if (dp->link_train.lane_count > max_lanes)
679 		dp->link_train.lane_count = max_lanes;
680 	if (dp->link_train.link_rate > max_rate)
681 		dp->link_train.link_rate = max_rate;
682 
683 	/* All DP analog module power up */
684 	analogix_dp_set_analog_power_down(dp, POWER_ALL, 0);
685 
686 	dp->link_train.lt_state = START;
687 
688 	/* Process here */
689 	while (!retval && !training_finished) {
690 		switch (dp->link_train.lt_state) {
691 		case START:
692 			retval = analogix_dp_link_start(dp);
693 			if (retval)
694 				dev_err(dp->dev, "LT link start failed!\n");
695 			break;
696 		case CLOCK_RECOVERY:
697 			retval = analogix_dp_process_clock_recovery(dp);
698 			if (retval)
699 				dev_err(dp->dev, "LT CR failed!\n");
700 			break;
701 		case EQUALIZER_TRAINING:
702 			retval = analogix_dp_process_equalizer_training(dp);
703 			if (retval)
704 				dev_err(dp->dev, "LT EQ failed!\n");
705 			break;
706 		case FINISHED:
707 			training_finished = 1;
708 			break;
709 		case FAILED:
710 			return -EREMOTEIO;
711 		}
712 	}
713 	if (retval)
714 		dev_err(dp->dev, "eDP link training failed (%d)\n", retval);
715 
716 	return retval;
717 }
718 
719 static int analogix_dp_fast_link_train(struct analogix_dp_device *dp)
720 {
721 	int i, ret;
722 	u8 link_align, link_status[2];
723 	enum pll_status status;
724 
725 	analogix_dp_reset_macro(dp);
726 
727 	analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
728 	analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
729 
730 	for (i = 0; i < dp->link_train.lane_count; i++) {
731 		analogix_dp_set_lane_link_training(dp,
732 			dp->link_train.training_lane[i], i);
733 	}
734 
735 	ret = readx_poll_timeout(analogix_dp_get_pll_lock_status, dp, status,
736 				 status != PLL_UNLOCKED, 120,
737 				 120 * DP_TIMEOUT_LOOP_COUNT);
738 	if (ret) {
739 		DRM_DEV_ERROR(dp->dev, "Wait for pll lock failed %d\n", ret);
740 		return ret;
741 	}
742 
743 	/* source Set training pattern 1 */
744 	analogix_dp_set_training_pattern(dp, TRAINING_PTN1);
745 	/* From DP spec, pattern must be on-screen for a minimum 500us */
746 	usleep_range(500, 600);
747 
748 	analogix_dp_set_training_pattern(dp, TRAINING_PTN2);
749 	/* From DP spec, pattern must be on-screen for a minimum 500us */
750 	usleep_range(500, 600);
751 
752 	/* TODO: enhanced_mode?*/
753 	analogix_dp_set_training_pattern(dp, DP_NONE);
754 
755 	/*
756 	 * Useful for debugging issues with fast link training, disable for more
757 	 * speed
758 	 */
759 	if (verify_fast_training) {
760 		ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_ALIGN_STATUS_UPDATED,
761 					&link_align);
762 		if (ret < 0) {
763 			DRM_DEV_ERROR(dp->dev, "Read align status failed %d\n",
764 				      ret);
765 			return ret;
766 		}
767 
768 		ret = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status,
769 				       2);
770 		if (ret < 0) {
771 			DRM_DEV_ERROR(dp->dev, "Read link status failed %d\n",
772 				      ret);
773 			return ret;
774 		}
775 
776 		if (analogix_dp_clock_recovery_ok(link_status,
777 						  dp->link_train.lane_count)) {
778 			DRM_DEV_ERROR(dp->dev, "Clock recovery failed\n");
779 			analogix_dp_reduce_link_rate(dp);
780 			return -EIO;
781 		}
782 
783 		if (analogix_dp_channel_eq_ok(link_status, link_align,
784 					      dp->link_train.lane_count)) {
785 			DRM_DEV_ERROR(dp->dev, "Channel EQ failed\n");
786 			analogix_dp_reduce_link_rate(dp);
787 			return -EIO;
788 		}
789 	}
790 
791 	return 0;
792 }
793 
794 static int analogix_dp_train_link(struct analogix_dp_device *dp)
795 {
796 	if (dp->fast_train_support)
797 		return analogix_dp_fast_link_train(dp);
798 
799 	return analogix_dp_full_link_train(dp, dp->video_info.max_lane_count,
800 					   dp->video_info.max_link_rate);
801 }
802 
803 static int analogix_dp_config_video(struct analogix_dp_device *dp)
804 {
805 	int timeout_loop = 0;
806 	int done_count = 0;
807 
808 	analogix_dp_config_video_slave_mode(dp);
809 
810 	analogix_dp_set_video_color_format(dp);
811 
812 	if (analogix_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) {
813 		dev_err(dp->dev, "PLL is not locked yet.\n");
814 		return -EINVAL;
815 	}
816 
817 	for (;;) {
818 		timeout_loop++;
819 		if (analogix_dp_is_slave_video_stream_clock_on(dp) == 0)
820 			break;
821 		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
822 			dev_err(dp->dev, "Timeout of video streamclk ok\n");
823 			return -ETIMEDOUT;
824 		}
825 
826 		usleep_range(1, 2);
827 	}
828 
829 	/* Set to use the register calculated M/N video */
830 	analogix_dp_set_video_cr_mn(dp, CALCULATED_M, 0, 0);
831 
832 	/* For video bist, Video timing must be generated by register */
833 	analogix_dp_set_video_timing_mode(dp, VIDEO_TIMING_FROM_CAPTURE);
834 
835 	/* Disable video mute */
836 	analogix_dp_enable_video_mute(dp, 0);
837 
838 	/* Configure video slave mode */
839 	analogix_dp_enable_video_master(dp, 0);
840 
841 	timeout_loop = 0;
842 
843 	for (;;) {
844 		timeout_loop++;
845 		if (analogix_dp_is_video_stream_on(dp) == 0) {
846 			done_count++;
847 			if (done_count > 10)
848 				break;
849 		} else if (done_count) {
850 			done_count = 0;
851 		}
852 		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
853 			dev_err(dp->dev, "Timeout of video streamclk ok\n");
854 			return -ETIMEDOUT;
855 		}
856 
857 		usleep_range(1000, 1001);
858 	}
859 
860 	return 0;
861 }
862 
863 static void analogix_dp_enable_scramble(struct analogix_dp_device *dp,
864 					bool enable)
865 {
866 	u8 data;
867 
868 	if (enable) {
869 		analogix_dp_enable_scrambling(dp);
870 
871 		drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
872 		drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
873 				   (u8)(data & ~DP_LINK_SCRAMBLING_DISABLE));
874 	} else {
875 		analogix_dp_disable_scrambling(dp);
876 
877 		drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
878 		drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
879 				   (u8)(data | DP_LINK_SCRAMBLING_DISABLE));
880 	}
881 }
882 
883 static irqreturn_t analogix_dp_hardirq(int irq, void *arg)
884 {
885 	struct analogix_dp_device *dp = arg;
886 	irqreturn_t ret = IRQ_NONE;
887 	enum dp_irq_type irq_type;
888 
889 	irq_type = analogix_dp_get_irq_type(dp);
890 	if (irq_type != DP_IRQ_TYPE_UNKNOWN) {
891 		analogix_dp_mute_hpd_interrupt(dp);
892 		ret = IRQ_WAKE_THREAD;
893 	}
894 
895 	return ret;
896 }
897 
898 static irqreturn_t analogix_dp_irq_thread(int irq, void *arg)
899 {
900 	struct analogix_dp_device *dp = arg;
901 	enum dp_irq_type irq_type;
902 
903 	irq_type = analogix_dp_get_irq_type(dp);
904 	if (irq_type & DP_IRQ_TYPE_HP_CABLE_IN ||
905 	    irq_type & DP_IRQ_TYPE_HP_CABLE_OUT) {
906 		dev_dbg(dp->dev, "Detected cable status changed!\n");
907 		if (dp->drm_dev)
908 			drm_helper_hpd_irq_event(dp->drm_dev);
909 	}
910 
911 	if (irq_type != DP_IRQ_TYPE_UNKNOWN) {
912 		analogix_dp_clear_hotplug_interrupts(dp);
913 		analogix_dp_unmute_hpd_interrupt(dp);
914 	}
915 
916 	return IRQ_HANDLED;
917 }
918 
919 static void analogix_dp_commit(struct analogix_dp_device *dp)
920 {
921 	int ret;
922 
923 	/* Keep the panel disabled while we configure video */
924 	if (dp->plat_data->panel) {
925 		if (drm_panel_disable(dp->plat_data->panel))
926 			DRM_ERROR("failed to disable the panel\n");
927 	}
928 
929 	ret = readx_poll_timeout(analogix_dp_train_link, dp, ret, !ret, 100,
930 				 DP_TIMEOUT_TRAINING_US * 5);
931 	if (ret) {
932 		dev_err(dp->dev, "unable to do link train, ret=%d\n", ret);
933 		return;
934 	}
935 
936 	analogix_dp_enable_scramble(dp, 1);
937 	analogix_dp_enable_rx_to_enhanced_mode(dp, 1);
938 	analogix_dp_enable_enhanced_mode(dp, 1);
939 
940 	analogix_dp_init_video(dp);
941 	ret = analogix_dp_config_video(dp);
942 	if (ret)
943 		dev_err(dp->dev, "unable to config video\n");
944 
945 	/* Safe to enable the panel now */
946 	if (dp->plat_data->panel) {
947 		if (drm_panel_enable(dp->plat_data->panel))
948 			DRM_ERROR("failed to enable the panel\n");
949 	}
950 
951 	/* Enable video */
952 	analogix_dp_start_video(dp);
953 
954 	dp->psr_enable = analogix_dp_detect_sink_psr(dp);
955 	if (dp->psr_enable)
956 		analogix_dp_enable_sink_psr(dp);
957 }
958 
959 /*
960  * This function is a bit of a catch-all for panel preparation, hopefully
961  * simplifying the logic of functions that need to prepare/unprepare the panel
962  * below.
963  *
964  * If @prepare is true, this function will prepare the panel. Conversely, if it
965  * is false, the panel will be unprepared.
966  *
967  * If @is_modeset_prepare is true, the function will disregard the current state
968  * of the panel and either prepare/unprepare the panel based on @prepare. Once
969  * it finishes, it will update dp->panel_is_modeset to reflect the current state
970  * of the panel.
971  */
972 static int analogix_dp_prepare_panel(struct analogix_dp_device *dp,
973 				     bool prepare, bool is_modeset_prepare)
974 {
975 	int ret = 0;
976 
977 	if (!dp->plat_data->panel)
978 		return 0;
979 
980 	mutex_lock(&dp->panel_lock);
981 
982 	/*
983 	 * Exit early if this is a temporary prepare/unprepare and we're already
984 	 * modeset (since we neither want to prepare twice or unprepare early).
985 	 */
986 	if (dp->panel_is_modeset && !is_modeset_prepare)
987 		goto out;
988 
989 	if (prepare)
990 		ret = drm_panel_prepare(dp->plat_data->panel);
991 	else
992 		ret = drm_panel_unprepare(dp->plat_data->panel);
993 
994 	if (ret)
995 		goto out;
996 
997 	if (is_modeset_prepare)
998 		dp->panel_is_modeset = prepare;
999 
1000 out:
1001 	mutex_unlock(&dp->panel_lock);
1002 	return ret;
1003 }
1004 
1005 static int analogix_dp_get_modes(struct drm_connector *connector)
1006 {
1007 	struct analogix_dp_device *dp = to_dp(connector);
1008 	struct edid *edid;
1009 	int ret, num_modes = 0;
1010 
1011 	if (dp->plat_data->panel) {
1012 		num_modes += drm_panel_get_modes(dp->plat_data->panel);
1013 	} else {
1014 		ret = analogix_dp_prepare_panel(dp, true, false);
1015 		if (ret) {
1016 			DRM_ERROR("Failed to prepare panel (%d)\n", ret);
1017 			return 0;
1018 		}
1019 
1020 		pm_runtime_get_sync(dp->dev);
1021 		edid = drm_get_edid(connector, &dp->aux.ddc);
1022 		pm_runtime_put(dp->dev);
1023 		if (edid) {
1024 			drm_mode_connector_update_edid_property(&dp->connector,
1025 								edid);
1026 			num_modes += drm_add_edid_modes(&dp->connector, edid);
1027 			kfree(edid);
1028 		}
1029 
1030 		ret = analogix_dp_prepare_panel(dp, false, false);
1031 		if (ret)
1032 			DRM_ERROR("Failed to unprepare panel (%d)\n", ret);
1033 	}
1034 
1035 	if (dp->plat_data->get_modes)
1036 		num_modes += dp->plat_data->get_modes(dp->plat_data, connector);
1037 
1038 	return num_modes;
1039 }
1040 
1041 static struct drm_encoder *
1042 analogix_dp_best_encoder(struct drm_connector *connector)
1043 {
1044 	struct analogix_dp_device *dp = to_dp(connector);
1045 
1046 	return dp->encoder;
1047 }
1048 
1049 static const struct drm_connector_helper_funcs analogix_dp_connector_helper_funcs = {
1050 	.get_modes = analogix_dp_get_modes,
1051 	.best_encoder = analogix_dp_best_encoder,
1052 };
1053 
1054 static enum drm_connector_status
1055 analogix_dp_detect(struct drm_connector *connector, bool force)
1056 {
1057 	struct analogix_dp_device *dp = to_dp(connector);
1058 	enum drm_connector_status status = connector_status_disconnected;
1059 	int ret;
1060 
1061 	if (dp->plat_data->panel)
1062 		return connector_status_connected;
1063 
1064 	ret = analogix_dp_prepare_panel(dp, true, false);
1065 	if (ret) {
1066 		DRM_ERROR("Failed to prepare panel (%d)\n", ret);
1067 		return connector_status_disconnected;
1068 	}
1069 
1070 	if (!analogix_dp_detect_hpd(dp))
1071 		status = connector_status_connected;
1072 
1073 	ret = analogix_dp_prepare_panel(dp, false, false);
1074 	if (ret)
1075 		DRM_ERROR("Failed to unprepare panel (%d)\n", ret);
1076 
1077 	return status;
1078 }
1079 
1080 static const struct drm_connector_funcs analogix_dp_connector_funcs = {
1081 	.fill_modes = drm_helper_probe_single_connector_modes,
1082 	.detect = analogix_dp_detect,
1083 	.destroy = drm_connector_cleanup,
1084 	.reset = drm_atomic_helper_connector_reset,
1085 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1086 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1087 };
1088 
1089 static int analogix_dp_bridge_attach(struct drm_bridge *bridge)
1090 {
1091 	struct analogix_dp_device *dp = bridge->driver_private;
1092 	struct drm_encoder *encoder = dp->encoder;
1093 	struct drm_connector *connector = NULL;
1094 	int ret = 0;
1095 
1096 	if (!bridge->encoder) {
1097 		DRM_ERROR("Parent encoder object not found");
1098 		return -ENODEV;
1099 	}
1100 
1101 	if (!dp->plat_data->skip_connector) {
1102 		connector = &dp->connector;
1103 		connector->polled = DRM_CONNECTOR_POLL_HPD;
1104 
1105 		ret = drm_connector_init(dp->drm_dev, connector,
1106 					 &analogix_dp_connector_funcs,
1107 					 DRM_MODE_CONNECTOR_eDP);
1108 		if (ret) {
1109 			DRM_ERROR("Failed to initialize connector with drm\n");
1110 			return ret;
1111 		}
1112 
1113 		drm_connector_helper_add(connector,
1114 					 &analogix_dp_connector_helper_funcs);
1115 		drm_mode_connector_attach_encoder(connector, encoder);
1116 	}
1117 
1118 	/*
1119 	 * NOTE: the connector registration is implemented in analogix
1120 	 * platform driver, that to say connector would be exist after
1121 	 * plat_data->attch return, that's why we record the connector
1122 	 * point after plat attached.
1123 	 */
1124 	 if (dp->plat_data->attach) {
1125 		 ret = dp->plat_data->attach(dp->plat_data, bridge, connector);
1126 		 if (ret) {
1127 			 DRM_ERROR("Failed at platform attch func\n");
1128 			 return ret;
1129 		 }
1130 	}
1131 
1132 	if (dp->plat_data->panel) {
1133 		ret = drm_panel_attach(dp->plat_data->panel, &dp->connector);
1134 		if (ret) {
1135 			DRM_ERROR("Failed to attach panel\n");
1136 			return ret;
1137 		}
1138 	}
1139 
1140 	return 0;
1141 }
1142 
1143 static void analogix_dp_bridge_pre_enable(struct drm_bridge *bridge)
1144 {
1145 	struct analogix_dp_device *dp = bridge->driver_private;
1146 	int ret;
1147 
1148 	ret = analogix_dp_prepare_panel(dp, true, true);
1149 	if (ret)
1150 		DRM_ERROR("failed to setup the panel ret = %d\n", ret);
1151 }
1152 
1153 static void analogix_dp_bridge_enable(struct drm_bridge *bridge)
1154 {
1155 	struct analogix_dp_device *dp = bridge->driver_private;
1156 
1157 	if (dp->dpms_mode == DRM_MODE_DPMS_ON)
1158 		return;
1159 
1160 	pm_runtime_get_sync(dp->dev);
1161 
1162 	if (dp->plat_data->power_on)
1163 		dp->plat_data->power_on(dp->plat_data);
1164 
1165 	phy_power_on(dp->phy);
1166 	analogix_dp_init_dp(dp);
1167 	enable_irq(dp->irq);
1168 	analogix_dp_commit(dp);
1169 
1170 	dp->dpms_mode = DRM_MODE_DPMS_ON;
1171 }
1172 
1173 static void analogix_dp_bridge_disable(struct drm_bridge *bridge)
1174 {
1175 	struct analogix_dp_device *dp = bridge->driver_private;
1176 	int ret;
1177 
1178 	if (dp->dpms_mode != DRM_MODE_DPMS_ON)
1179 		return;
1180 
1181 	if (dp->plat_data->panel) {
1182 		if (drm_panel_disable(dp->plat_data->panel)) {
1183 			DRM_ERROR("failed to disable the panel\n");
1184 			return;
1185 		}
1186 	}
1187 
1188 	disable_irq(dp->irq);
1189 	phy_power_off(dp->phy);
1190 
1191 	if (dp->plat_data->power_off)
1192 		dp->plat_data->power_off(dp->plat_data);
1193 
1194 	pm_runtime_put_sync(dp->dev);
1195 
1196 	ret = analogix_dp_prepare_panel(dp, false, true);
1197 	if (ret)
1198 		DRM_ERROR("failed to setup the panel ret = %d\n", ret);
1199 
1200 	dp->psr_enable = false;
1201 	dp->dpms_mode = DRM_MODE_DPMS_OFF;
1202 }
1203 
1204 static void analogix_dp_bridge_mode_set(struct drm_bridge *bridge,
1205 					struct drm_display_mode *orig_mode,
1206 					struct drm_display_mode *mode)
1207 {
1208 	struct analogix_dp_device *dp = bridge->driver_private;
1209 	struct drm_display_info *display_info = &dp->connector.display_info;
1210 	struct video_info *video = &dp->video_info;
1211 	struct device_node *dp_node = dp->dev->of_node;
1212 	int vic;
1213 
1214 	/* Input video interlaces & hsync pol & vsync pol */
1215 	video->interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
1216 	video->v_sync_polarity = !!(mode->flags & DRM_MODE_FLAG_NVSYNC);
1217 	video->h_sync_polarity = !!(mode->flags & DRM_MODE_FLAG_NHSYNC);
1218 
1219 	/* Input video dynamic_range & colorimetry */
1220 	vic = drm_match_cea_mode(mode);
1221 	if ((vic == 6) || (vic == 7) || (vic == 21) || (vic == 22) ||
1222 	    (vic == 2) || (vic == 3) || (vic == 17) || (vic == 18)) {
1223 		video->dynamic_range = CEA;
1224 		video->ycbcr_coeff = COLOR_YCBCR601;
1225 	} else if (vic) {
1226 		video->dynamic_range = CEA;
1227 		video->ycbcr_coeff = COLOR_YCBCR709;
1228 	} else {
1229 		video->dynamic_range = VESA;
1230 		video->ycbcr_coeff = COLOR_YCBCR709;
1231 	}
1232 
1233 	/* Input vide bpc and color_formats */
1234 	switch (display_info->bpc) {
1235 	case 12:
1236 		video->color_depth = COLOR_12;
1237 		break;
1238 	case 10:
1239 		video->color_depth = COLOR_10;
1240 		break;
1241 	case 8:
1242 		video->color_depth = COLOR_8;
1243 		break;
1244 	case 6:
1245 		video->color_depth = COLOR_6;
1246 		break;
1247 	default:
1248 		video->color_depth = COLOR_8;
1249 		break;
1250 	}
1251 	if (display_info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
1252 		video->color_space = COLOR_YCBCR444;
1253 	else if (display_info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
1254 		video->color_space = COLOR_YCBCR422;
1255 	else if (display_info->color_formats & DRM_COLOR_FORMAT_RGB444)
1256 		video->color_space = COLOR_RGB;
1257 	else
1258 		video->color_space = COLOR_RGB;
1259 
1260 	/*
1261 	 * NOTE: those property parsing code is used for providing backward
1262 	 * compatibility for samsung platform.
1263 	 * Due to we used the "of_property_read_u32" interfaces, when this
1264 	 * property isn't present, the "video_info" can keep the original
1265 	 * values and wouldn't be modified.
1266 	 */
1267 	of_property_read_u32(dp_node, "samsung,color-space",
1268 			     &video->color_space);
1269 	of_property_read_u32(dp_node, "samsung,dynamic-range",
1270 			     &video->dynamic_range);
1271 	of_property_read_u32(dp_node, "samsung,ycbcr-coeff",
1272 			     &video->ycbcr_coeff);
1273 	of_property_read_u32(dp_node, "samsung,color-depth",
1274 			     &video->color_depth);
1275 	if (of_property_read_bool(dp_node, "hsync-active-high"))
1276 		video->h_sync_polarity = true;
1277 	if (of_property_read_bool(dp_node, "vsync-active-high"))
1278 		video->v_sync_polarity = true;
1279 	if (of_property_read_bool(dp_node, "interlaced"))
1280 		video->interlaced = true;
1281 }
1282 
1283 static void analogix_dp_bridge_nop(struct drm_bridge *bridge)
1284 {
1285 	/* do nothing */
1286 }
1287 
1288 static const struct drm_bridge_funcs analogix_dp_bridge_funcs = {
1289 	.pre_enable = analogix_dp_bridge_pre_enable,
1290 	.enable = analogix_dp_bridge_enable,
1291 	.disable = analogix_dp_bridge_disable,
1292 	.post_disable = analogix_dp_bridge_nop,
1293 	.mode_set = analogix_dp_bridge_mode_set,
1294 	.attach = analogix_dp_bridge_attach,
1295 };
1296 
1297 static int analogix_dp_create_bridge(struct drm_device *drm_dev,
1298 				     struct analogix_dp_device *dp)
1299 {
1300 	struct drm_bridge *bridge;
1301 	int ret;
1302 
1303 	bridge = devm_kzalloc(drm_dev->dev, sizeof(*bridge), GFP_KERNEL);
1304 	if (!bridge) {
1305 		DRM_ERROR("failed to allocate for drm bridge\n");
1306 		return -ENOMEM;
1307 	}
1308 
1309 	dp->bridge = bridge;
1310 
1311 	bridge->driver_private = dp;
1312 	bridge->funcs = &analogix_dp_bridge_funcs;
1313 
1314 	ret = drm_bridge_attach(dp->encoder, bridge, NULL);
1315 	if (ret) {
1316 		DRM_ERROR("failed to attach drm bridge\n");
1317 		return -EINVAL;
1318 	}
1319 
1320 	return 0;
1321 }
1322 
1323 static int analogix_dp_dt_parse_pdata(struct analogix_dp_device *dp)
1324 {
1325 	struct device_node *dp_node = dp->dev->of_node;
1326 	struct video_info *video_info = &dp->video_info;
1327 
1328 	switch (dp->plat_data->dev_type) {
1329 	case RK3288_DP:
1330 	case RK3399_EDP:
1331 		/*
1332 		 * Like Rk3288 DisplayPort TRM indicate that "Main link
1333 		 * containing 4 physical lanes of 2.7/1.62 Gbps/lane".
1334 		 */
1335 		video_info->max_link_rate = 0x0A;
1336 		video_info->max_lane_count = 0x04;
1337 		break;
1338 	case EXYNOS_DP:
1339 		/*
1340 		 * NOTE: those property parseing code is used for
1341 		 * providing backward compatibility for samsung platform.
1342 		 */
1343 		of_property_read_u32(dp_node, "samsung,link-rate",
1344 				     &video_info->max_link_rate);
1345 		of_property_read_u32(dp_node, "samsung,lane-count",
1346 				     &video_info->max_lane_count);
1347 		break;
1348 	}
1349 
1350 	return 0;
1351 }
1352 
1353 static ssize_t analogix_dpaux_transfer(struct drm_dp_aux *aux,
1354 				       struct drm_dp_aux_msg *msg)
1355 {
1356 	struct analogix_dp_device *dp = to_dp(aux);
1357 
1358 	return analogix_dp_transfer(dp, msg);
1359 }
1360 
1361 struct analogix_dp_device *
1362 analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
1363 		 struct analogix_dp_plat_data *plat_data)
1364 {
1365 	struct platform_device *pdev = to_platform_device(dev);
1366 	struct analogix_dp_device *dp;
1367 	struct resource *res;
1368 	unsigned int irq_flags;
1369 	int ret;
1370 
1371 	if (!plat_data) {
1372 		dev_err(dev, "Invalided input plat_data\n");
1373 		return ERR_PTR(-EINVAL);
1374 	}
1375 
1376 	dp = devm_kzalloc(dev, sizeof(struct analogix_dp_device), GFP_KERNEL);
1377 	if (!dp)
1378 		return ERR_PTR(-ENOMEM);
1379 
1380 	dp->dev = &pdev->dev;
1381 	dp->dpms_mode = DRM_MODE_DPMS_OFF;
1382 
1383 	mutex_init(&dp->panel_lock);
1384 	dp->panel_is_modeset = false;
1385 
1386 	/*
1387 	 * platform dp driver need containor_of the plat_data to get
1388 	 * the driver private data, so we need to store the point of
1389 	 * plat_data, not the context of plat_data.
1390 	 */
1391 	dp->plat_data = plat_data;
1392 
1393 	ret = analogix_dp_dt_parse_pdata(dp);
1394 	if (ret)
1395 		return ERR_PTR(ret);
1396 
1397 	dp->phy = devm_phy_get(dp->dev, "dp");
1398 	if (IS_ERR(dp->phy)) {
1399 		dev_err(dp->dev, "no DP phy configured\n");
1400 		ret = PTR_ERR(dp->phy);
1401 		if (ret) {
1402 			/*
1403 			 * phy itself is not enabled, so we can move forward
1404 			 * assigning NULL to phy pointer.
1405 			 */
1406 			if (ret == -ENOSYS || ret == -ENODEV)
1407 				dp->phy = NULL;
1408 			else
1409 				return ERR_PTR(ret);
1410 		}
1411 	}
1412 
1413 	dp->clock = devm_clk_get(&pdev->dev, "dp");
1414 	if (IS_ERR(dp->clock)) {
1415 		dev_err(&pdev->dev, "failed to get clock\n");
1416 		return ERR_CAST(dp->clock);
1417 	}
1418 
1419 	clk_prepare_enable(dp->clock);
1420 
1421 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1422 
1423 	dp->reg_base = devm_ioremap_resource(&pdev->dev, res);
1424 	if (IS_ERR(dp->reg_base))
1425 		return ERR_CAST(dp->reg_base);
1426 
1427 	dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd");
1428 
1429 	dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
1430 	if (!gpio_is_valid(dp->hpd_gpio))
1431 		dp->hpd_gpio = of_get_named_gpio(dev->of_node,
1432 						 "samsung,hpd-gpio", 0);
1433 
1434 	if (gpio_is_valid(dp->hpd_gpio)) {
1435 		/*
1436 		 * Set up the hotplug GPIO from the device tree as an interrupt.
1437 		 * Simply specifying a different interrupt in the device tree
1438 		 * doesn't work since we handle hotplug rather differently when
1439 		 * using a GPIO.  We also need the actual GPIO specifier so
1440 		 * that we can get the current state of the GPIO.
1441 		 */
1442 		ret = devm_gpio_request_one(&pdev->dev, dp->hpd_gpio, GPIOF_IN,
1443 					    "hpd_gpio");
1444 		if (ret) {
1445 			dev_err(&pdev->dev, "failed to get hpd gpio\n");
1446 			return ERR_PTR(ret);
1447 		}
1448 		dp->irq = gpio_to_irq(dp->hpd_gpio);
1449 		irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
1450 	} else {
1451 		dp->hpd_gpio = -ENODEV;
1452 		dp->irq = platform_get_irq(pdev, 0);
1453 		irq_flags = 0;
1454 	}
1455 
1456 	if (dp->irq == -ENXIO) {
1457 		dev_err(&pdev->dev, "failed to get irq\n");
1458 		return ERR_PTR(-ENODEV);
1459 	}
1460 
1461 	ret = devm_request_threaded_irq(&pdev->dev, dp->irq,
1462 					analogix_dp_hardirq,
1463 					analogix_dp_irq_thread,
1464 					irq_flags, "analogix-dp", dp);
1465 	if (ret) {
1466 		dev_err(&pdev->dev, "failed to request irq\n");
1467 		goto err_disable_pm_runtime;
1468 	}
1469 	disable_irq(dp->irq);
1470 
1471 	dp->drm_dev = drm_dev;
1472 	dp->encoder = dp->plat_data->encoder;
1473 
1474 	dp->aux.name = "DP-AUX";
1475 	dp->aux.transfer = analogix_dpaux_transfer;
1476 	dp->aux.dev = &pdev->dev;
1477 
1478 	ret = drm_dp_aux_register(&dp->aux);
1479 	if (ret)
1480 		return ERR_PTR(ret);
1481 
1482 	pm_runtime_enable(dev);
1483 
1484 	ret = analogix_dp_create_bridge(drm_dev, dp);
1485 	if (ret) {
1486 		DRM_ERROR("failed to create bridge (%d)\n", ret);
1487 		goto err_disable_pm_runtime;
1488 	}
1489 
1490 	return dp;
1491 
1492 err_disable_pm_runtime:
1493 
1494 	pm_runtime_disable(dev);
1495 
1496 	return ERR_PTR(ret);
1497 }
1498 EXPORT_SYMBOL_GPL(analogix_dp_bind);
1499 
1500 void analogix_dp_unbind(struct analogix_dp_device *dp)
1501 {
1502 	analogix_dp_bridge_disable(dp->bridge);
1503 	dp->connector.funcs->destroy(&dp->connector);
1504 
1505 	if (dp->plat_data->panel) {
1506 		if (drm_panel_unprepare(dp->plat_data->panel))
1507 			DRM_ERROR("failed to turnoff the panel\n");
1508 		if (drm_panel_detach(dp->plat_data->panel))
1509 			DRM_ERROR("failed to detach the panel\n");
1510 	}
1511 
1512 	drm_dp_aux_unregister(&dp->aux);
1513 	pm_runtime_disable(dp->dev);
1514 	clk_disable_unprepare(dp->clock);
1515 }
1516 EXPORT_SYMBOL_GPL(analogix_dp_unbind);
1517 
1518 #ifdef CONFIG_PM
1519 int analogix_dp_suspend(struct analogix_dp_device *dp)
1520 {
1521 	clk_disable_unprepare(dp->clock);
1522 
1523 	if (dp->plat_data->panel) {
1524 		if (drm_panel_unprepare(dp->plat_data->panel))
1525 			DRM_ERROR("failed to turnoff the panel\n");
1526 	}
1527 
1528 	return 0;
1529 }
1530 EXPORT_SYMBOL_GPL(analogix_dp_suspend);
1531 
1532 int analogix_dp_resume(struct analogix_dp_device *dp)
1533 {
1534 	int ret;
1535 
1536 	ret = clk_prepare_enable(dp->clock);
1537 	if (ret < 0) {
1538 		DRM_ERROR("Failed to prepare_enable the clock clk [%d]\n", ret);
1539 		return ret;
1540 	}
1541 
1542 	if (dp->plat_data->panel) {
1543 		if (drm_panel_prepare(dp->plat_data->panel)) {
1544 			DRM_ERROR("failed to setup the panel\n");
1545 			return -EBUSY;
1546 		}
1547 	}
1548 
1549 	return 0;
1550 }
1551 EXPORT_SYMBOL_GPL(analogix_dp_resume);
1552 #endif
1553 
1554 int analogix_dp_start_crc(struct drm_connector *connector)
1555 {
1556 	struct analogix_dp_device *dp = to_dp(connector);
1557 
1558 	if (!connector->state->crtc) {
1559 		DRM_ERROR("Connector %s doesn't currently have a CRTC.\n",
1560 			  connector->name);
1561 		return -EINVAL;
1562 	}
1563 
1564 	return drm_dp_start_crc(&dp->aux, connector->state->crtc);
1565 }
1566 EXPORT_SYMBOL_GPL(analogix_dp_start_crc);
1567 
1568 int analogix_dp_stop_crc(struct drm_connector *connector)
1569 {
1570 	struct analogix_dp_device *dp = to_dp(connector);
1571 
1572 	return drm_dp_stop_crc(&dp->aux);
1573 }
1574 EXPORT_SYMBOL_GPL(analogix_dp_stop_crc);
1575 
1576 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
1577 MODULE_DESCRIPTION("Analogix DP Core Driver");
1578 MODULE_LICENSE("GPL v2");
1579