xref: /openbmc/linux/drivers/gpu/drm/msm/dp/dp_link.c (revision 3c8c1539)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
4  */
5 
6 #define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__
7 
8 #include <drm/drm_print.h>
9 
10 #include "dp_link.h"
11 #include "dp_panel.h"
12 
13 #define DP_TEST_REQUEST_MASK		0x7F
14 
15 enum audio_sample_rate {
16 	AUDIO_SAMPLE_RATE_32_KHZ	= 0x00,
17 	AUDIO_SAMPLE_RATE_44_1_KHZ	= 0x01,
18 	AUDIO_SAMPLE_RATE_48_KHZ	= 0x02,
19 	AUDIO_SAMPLE_RATE_88_2_KHZ	= 0x03,
20 	AUDIO_SAMPLE_RATE_96_KHZ	= 0x04,
21 	AUDIO_SAMPLE_RATE_176_4_KHZ	= 0x05,
22 	AUDIO_SAMPLE_RATE_192_KHZ	= 0x06,
23 };
24 
25 enum audio_pattern_type {
26 	AUDIO_TEST_PATTERN_OPERATOR_DEFINED	= 0x00,
27 	AUDIO_TEST_PATTERN_SAWTOOTH		= 0x01,
28 };
29 
30 struct dp_link_request {
31 	u32 test_requested;
32 	u32 test_link_rate;
33 	u32 test_lane_count;
34 };
35 
36 struct dp_link_private {
37 	u32 prev_sink_count;
38 	struct device *dev;
39 	struct drm_dp_aux *aux;
40 	struct dp_link dp_link;
41 
42 	struct dp_link_request request;
43 	struct mutex psm_mutex;
44 	u8 link_status[DP_LINK_STATUS_SIZE];
45 };
46 
47 static int dp_aux_link_power_up(struct drm_dp_aux *aux,
48 					struct dp_link_info *link)
49 {
50 	u8 value;
51 	int err;
52 
53 	if (link->revision < 0x11)
54 		return 0;
55 
56 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
57 	if (err < 0)
58 		return err;
59 
60 	value &= ~DP_SET_POWER_MASK;
61 	value |= DP_SET_POWER_D0;
62 
63 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
64 	if (err < 0)
65 		return err;
66 
67 	usleep_range(1000, 2000);
68 
69 	return 0;
70 }
71 
72 static int dp_aux_link_power_down(struct drm_dp_aux *aux,
73 					struct dp_link_info *link)
74 {
75 	u8 value;
76 	int err;
77 
78 	if (link->revision < 0x11)
79 		return 0;
80 
81 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
82 	if (err < 0)
83 		return err;
84 
85 	value &= ~DP_SET_POWER_MASK;
86 	value |= DP_SET_POWER_D3;
87 
88 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
89 	if (err < 0)
90 		return err;
91 
92 	return 0;
93 }
94 
95 static int dp_link_get_period(struct dp_link_private *link, int const addr)
96 {
97 	int ret = 0;
98 	u8 data;
99 	u32 const max_audio_period = 0xA;
100 
101 	/* TEST_AUDIO_PERIOD_CH_XX */
102 	if (drm_dp_dpcd_readb(link->aux, addr, &data) < 0) {
103 		DRM_ERROR("failed to read test_audio_period (0x%x)\n", addr);
104 		ret = -EINVAL;
105 		goto exit;
106 	}
107 
108 	/* Period - Bits 3:0 */
109 	data = data & 0xF;
110 	if ((int)data > max_audio_period) {
111 		DRM_ERROR("invalid test_audio_period_ch_1 = 0x%x\n", data);
112 		ret = -EINVAL;
113 		goto exit;
114 	}
115 
116 	ret = data;
117 exit:
118 	return ret;
119 }
120 
121 static int dp_link_parse_audio_channel_period(struct dp_link_private *link)
122 {
123 	int ret = 0;
124 	struct dp_link_test_audio *req = &link->dp_link.test_audio;
125 
126 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH1);
127 	if (ret == -EINVAL)
128 		goto exit;
129 
130 	req->test_audio_period_ch_1 = ret;
131 	DRM_DEBUG_DP("test_audio_period_ch_1 = 0x%x\n", ret);
132 
133 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH2);
134 	if (ret == -EINVAL)
135 		goto exit;
136 
137 	req->test_audio_period_ch_2 = ret;
138 	DRM_DEBUG_DP("test_audio_period_ch_2 = 0x%x\n", ret);
139 
140 	/* TEST_AUDIO_PERIOD_CH_3 (Byte 0x275) */
141 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH3);
142 	if (ret == -EINVAL)
143 		goto exit;
144 
145 	req->test_audio_period_ch_3 = ret;
146 	DRM_DEBUG_DP("test_audio_period_ch_3 = 0x%x\n", ret);
147 
148 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH4);
149 	if (ret == -EINVAL)
150 		goto exit;
151 
152 	req->test_audio_period_ch_4 = ret;
153 	DRM_DEBUG_DP("test_audio_period_ch_4 = 0x%x\n", ret);
154 
155 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH5);
156 	if (ret == -EINVAL)
157 		goto exit;
158 
159 	req->test_audio_period_ch_5 = ret;
160 	DRM_DEBUG_DP("test_audio_period_ch_5 = 0x%x\n", ret);
161 
162 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH6);
163 	if (ret == -EINVAL)
164 		goto exit;
165 
166 	req->test_audio_period_ch_6 = ret;
167 	DRM_DEBUG_DP("test_audio_period_ch_6 = 0x%x\n", ret);
168 
169 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH7);
170 	if (ret == -EINVAL)
171 		goto exit;
172 
173 	req->test_audio_period_ch_7 = ret;
174 	DRM_DEBUG_DP("test_audio_period_ch_7 = 0x%x\n", ret);
175 
176 	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH8);
177 	if (ret == -EINVAL)
178 		goto exit;
179 
180 	req->test_audio_period_ch_8 = ret;
181 	DRM_DEBUG_DP("test_audio_period_ch_8 = 0x%x\n", ret);
182 exit:
183 	return ret;
184 }
185 
186 static int dp_link_parse_audio_pattern_type(struct dp_link_private *link)
187 {
188 	int ret = 0;
189 	u8 data;
190 	ssize_t rlen;
191 	int const max_audio_pattern_type = 0x1;
192 
193 	rlen = drm_dp_dpcd_readb(link->aux,
194 				DP_TEST_AUDIO_PATTERN_TYPE, &data);
195 	if (rlen < 0) {
196 		DRM_ERROR("failed to read link audio mode. rlen=%zd\n", rlen);
197 		return rlen;
198 	}
199 
200 	/* Audio Pattern Type - Bits 7:0 */
201 	if ((int)data > max_audio_pattern_type) {
202 		DRM_ERROR("invalid audio pattern type = 0x%x\n", data);
203 		ret = -EINVAL;
204 		goto exit;
205 	}
206 
207 	link->dp_link.test_audio.test_audio_pattern_type = data;
208 	DRM_DEBUG_DP("audio pattern type = 0x%x\n", data);
209 exit:
210 	return ret;
211 }
212 
213 static int dp_link_parse_audio_mode(struct dp_link_private *link)
214 {
215 	int ret = 0;
216 	u8 data;
217 	ssize_t rlen;
218 	int const max_audio_sampling_rate = 0x6;
219 	int const max_audio_channel_count = 0x8;
220 	int sampling_rate = 0x0;
221 	int channel_count = 0x0;
222 
223 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_AUDIO_MODE, &data);
224 	if (rlen < 0) {
225 		DRM_ERROR("failed to read link audio mode. rlen=%zd\n", rlen);
226 		return rlen;
227 	}
228 
229 	/* Sampling Rate - Bits 3:0 */
230 	sampling_rate = data & 0xF;
231 	if (sampling_rate > max_audio_sampling_rate) {
232 		DRM_ERROR("sampling rate (0x%x) greater than max (0x%x)\n",
233 				sampling_rate, max_audio_sampling_rate);
234 		ret = -EINVAL;
235 		goto exit;
236 	}
237 
238 	/* Channel Count - Bits 7:4 */
239 	channel_count = ((data & 0xF0) >> 4) + 1;
240 	if (channel_count > max_audio_channel_count) {
241 		DRM_ERROR("channel_count (0x%x) greater than max (0x%x)\n",
242 				channel_count, max_audio_channel_count);
243 		ret = -EINVAL;
244 		goto exit;
245 	}
246 
247 	link->dp_link.test_audio.test_audio_sampling_rate = sampling_rate;
248 	link->dp_link.test_audio.test_audio_channel_count = channel_count;
249 	DRM_DEBUG_DP("sampling_rate = 0x%x, channel_count = 0x%x\n",
250 					sampling_rate, channel_count);
251 exit:
252 	return ret;
253 }
254 
255 static int dp_link_parse_audio_pattern_params(struct dp_link_private *link)
256 {
257 	int ret = 0;
258 
259 	ret = dp_link_parse_audio_mode(link);
260 	if (ret)
261 		goto exit;
262 
263 	ret = dp_link_parse_audio_pattern_type(link);
264 	if (ret)
265 		goto exit;
266 
267 	ret = dp_link_parse_audio_channel_period(link);
268 
269 exit:
270 	return ret;
271 }
272 
273 static bool dp_link_is_video_pattern_valid(u32 pattern)
274 {
275 	switch (pattern) {
276 	case DP_NO_TEST_PATTERN:
277 	case DP_COLOR_RAMP:
278 	case DP_BLACK_AND_WHITE_VERTICAL_LINES:
279 	case DP_COLOR_SQUARE:
280 		return true;
281 	default:
282 		return false;
283 	}
284 }
285 
286 /**
287  * dp_link_is_bit_depth_valid() - validates the bit depth requested
288  * @tbd: bit depth requested by the sink
289  *
290  * Returns true if the requested bit depth is supported.
291  */
292 static bool dp_link_is_bit_depth_valid(u32 tbd)
293 {
294 	/* DP_TEST_VIDEO_PATTERN_NONE is treated as invalid */
295 	switch (tbd) {
296 	case DP_TEST_BIT_DEPTH_6:
297 	case DP_TEST_BIT_DEPTH_8:
298 	case DP_TEST_BIT_DEPTH_10:
299 		return true;
300 	default:
301 		return false;
302 	}
303 }
304 
305 static int dp_link_parse_timing_params1(struct dp_link_private *link,
306 					int addr, int len, u32 *val)
307 {
308 	u8 bp[2];
309 	int rlen;
310 
311 	if (len != 2)
312 		return -EINVAL;
313 
314 	/* Read the requested video link pattern (Byte 0x221). */
315 	rlen = drm_dp_dpcd_read(link->aux, addr, bp, len);
316 	if (rlen < len) {
317 		DRM_ERROR("failed to read 0x%x\n", addr);
318 		return -EINVAL;
319 	}
320 
321 	*val = bp[1] | (bp[0] << 8);
322 
323 	return 0;
324 }
325 
326 static int dp_link_parse_timing_params2(struct dp_link_private *link,
327 					int addr, int len,
328 					u32 *val1, u32 *val2)
329 {
330 	u8 bp[2];
331 	int rlen;
332 
333 	if (len != 2)
334 		return -EINVAL;
335 
336 	/* Read the requested video link pattern (Byte 0x221). */
337 	rlen = drm_dp_dpcd_read(link->aux, addr, bp, len);
338 	if (rlen < len) {
339 		DRM_ERROR("failed to read 0x%x\n", addr);
340 		return -EINVAL;
341 	}
342 
343 	*val1 = (bp[0] & BIT(7)) >> 7;
344 	*val2 = bp[1] | ((bp[0] & 0x7F) << 8);
345 
346 	return 0;
347 }
348 
349 static int dp_link_parse_timing_params3(struct dp_link_private *link,
350 					int addr, u32 *val)
351 {
352 	u8 bp;
353 	u32 len = 1;
354 	int rlen;
355 
356 	rlen = drm_dp_dpcd_read(link->aux, addr, &bp, len);
357 	if (rlen < 1) {
358 		DRM_ERROR("failed to read 0x%x\n", addr);
359 		return -EINVAL;
360 	}
361 	*val = bp;
362 
363 	return 0;
364 }
365 
366 /**
367  * dp_link_parse_video_pattern_params() - parses video pattern parameters from DPCD
368  * @link: Display Port Driver data
369  *
370  * Returns 0 if it successfully parses the video link pattern and the link
371  * bit depth requested by the sink and, and if the values parsed are valid.
372  */
373 static int dp_link_parse_video_pattern_params(struct dp_link_private *link)
374 {
375 	int ret = 0;
376 	ssize_t rlen;
377 	u8 bp;
378 
379 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_PATTERN, &bp);
380 	if (rlen < 0) {
381 		DRM_ERROR("failed to read link video pattern. rlen=%zd\n",
382 			rlen);
383 		return rlen;
384 	}
385 
386 	if (!dp_link_is_video_pattern_valid(bp)) {
387 		DRM_ERROR("invalid link video pattern = 0x%x\n", bp);
388 		ret = -EINVAL;
389 		return ret;
390 	}
391 
392 	link->dp_link.test_video.test_video_pattern = bp;
393 
394 	/* Read the requested color bit depth and dynamic range (Byte 0x232) */
395 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_MISC0, &bp);
396 	if (rlen < 0) {
397 		DRM_ERROR("failed to read link bit depth. rlen=%zd\n", rlen);
398 		return rlen;
399 	}
400 
401 	/* Dynamic Range */
402 	link->dp_link.test_video.test_dyn_range =
403 			(bp & DP_TEST_DYNAMIC_RANGE_CEA);
404 
405 	/* Color bit depth */
406 	bp &= DP_TEST_BIT_DEPTH_MASK;
407 	if (!dp_link_is_bit_depth_valid(bp)) {
408 		DRM_ERROR("invalid link bit depth = 0x%x\n", bp);
409 		ret = -EINVAL;
410 		return ret;
411 	}
412 
413 	link->dp_link.test_video.test_bit_depth = bp;
414 
415 	/* resolution timing params */
416 	ret = dp_link_parse_timing_params1(link, DP_TEST_H_TOTAL_HI, 2,
417 			&link->dp_link.test_video.test_h_total);
418 	if (ret) {
419 		DRM_ERROR("failed to parse test_htotal(DP_TEST_H_TOTAL_HI)\n");
420 		return ret;
421 	}
422 
423 	ret = dp_link_parse_timing_params1(link, DP_TEST_V_TOTAL_HI, 2,
424 			&link->dp_link.test_video.test_v_total);
425 	if (ret) {
426 		DRM_ERROR("failed to parse test_v_total(DP_TEST_V_TOTAL_HI)\n");
427 		return ret;
428 	}
429 
430 	ret = dp_link_parse_timing_params1(link, DP_TEST_H_START_HI, 2,
431 			&link->dp_link.test_video.test_h_start);
432 	if (ret) {
433 		DRM_ERROR("failed to parse test_h_start(DP_TEST_H_START_HI)\n");
434 		return ret;
435 	}
436 
437 	ret = dp_link_parse_timing_params1(link, DP_TEST_V_START_HI, 2,
438 			&link->dp_link.test_video.test_v_start);
439 	if (ret) {
440 		DRM_ERROR("failed to parse test_v_start(DP_TEST_V_START_HI)\n");
441 		return ret;
442 	}
443 
444 	ret = dp_link_parse_timing_params2(link, DP_TEST_HSYNC_HI, 2,
445 			&link->dp_link.test_video.test_hsync_pol,
446 			&link->dp_link.test_video.test_hsync_width);
447 	if (ret) {
448 		DRM_ERROR("failed to parse (DP_TEST_HSYNC_HI)\n");
449 		return ret;
450 	}
451 
452 	ret = dp_link_parse_timing_params2(link, DP_TEST_VSYNC_HI, 2,
453 			&link->dp_link.test_video.test_vsync_pol,
454 			&link->dp_link.test_video.test_vsync_width);
455 	if (ret) {
456 		DRM_ERROR("failed to parse (DP_TEST_VSYNC_HI)\n");
457 		return ret;
458 	}
459 
460 	ret = dp_link_parse_timing_params1(link, DP_TEST_H_WIDTH_HI, 2,
461 			&link->dp_link.test_video.test_h_width);
462 	if (ret) {
463 		DRM_ERROR("failed to parse test_h_width(DP_TEST_H_WIDTH_HI)\n");
464 		return ret;
465 	}
466 
467 	ret = dp_link_parse_timing_params1(link, DP_TEST_V_HEIGHT_HI, 2,
468 			&link->dp_link.test_video.test_v_height);
469 	if (ret) {
470 		DRM_ERROR("failed to parse test_v_height\n");
471 		return ret;
472 	}
473 
474 	ret = dp_link_parse_timing_params3(link, DP_TEST_MISC1,
475 		&link->dp_link.test_video.test_rr_d);
476 	link->dp_link.test_video.test_rr_d &= DP_TEST_REFRESH_DENOMINATOR;
477 	if (ret) {
478 		DRM_ERROR("failed to parse test_rr_d (DP_TEST_MISC1)\n");
479 		return ret;
480 	}
481 
482 	ret = dp_link_parse_timing_params3(link, DP_TEST_REFRESH_RATE_NUMERATOR,
483 		&link->dp_link.test_video.test_rr_n);
484 	if (ret) {
485 		DRM_ERROR("failed to parse test_rr_n\n");
486 		return ret;
487 	}
488 
489 	DRM_DEBUG_DP("link video pattern = 0x%x\n"
490 		"link dynamic range = 0x%x\n"
491 		"link bit depth = 0x%x\n"
492 		"TEST_H_TOTAL = %d, TEST_V_TOTAL = %d\n"
493 		"TEST_H_START = %d, TEST_V_START = %d\n"
494 		"TEST_HSYNC_POL = %d\n"
495 		"TEST_HSYNC_WIDTH = %d\n"
496 		"TEST_VSYNC_POL = %d\n"
497 		"TEST_VSYNC_WIDTH = %d\n"
498 		"TEST_H_WIDTH = %d\n"
499 		"TEST_V_HEIGHT = %d\n"
500 		"TEST_REFRESH_DENOMINATOR = %d\n"
501 		 "TEST_REFRESH_NUMERATOR = %d\n",
502 		link->dp_link.test_video.test_video_pattern,
503 		link->dp_link.test_video.test_dyn_range,
504 		link->dp_link.test_video.test_bit_depth,
505 		link->dp_link.test_video.test_h_total,
506 		link->dp_link.test_video.test_v_total,
507 		link->dp_link.test_video.test_h_start,
508 		link->dp_link.test_video.test_v_start,
509 		link->dp_link.test_video.test_hsync_pol,
510 		link->dp_link.test_video.test_hsync_width,
511 		link->dp_link.test_video.test_vsync_pol,
512 		link->dp_link.test_video.test_vsync_width,
513 		link->dp_link.test_video.test_h_width,
514 		link->dp_link.test_video.test_v_height,
515 		link->dp_link.test_video.test_rr_d,
516 		link->dp_link.test_video.test_rr_n);
517 
518 	return ret;
519 }
520 
521 /**
522  * dp_link_parse_link_training_params() - parses link training parameters from
523  * DPCD
524  * @link: Display Port Driver data
525  *
526  * Returns 0 if it successfully parses the link rate (Byte 0x219) and lane
527  * count (Byte 0x220), and if these values parse are valid.
528  */
529 static int dp_link_parse_link_training_params(struct dp_link_private *link)
530 {
531 	u8 bp;
532 	ssize_t rlen;
533 
534 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_LINK_RATE,	&bp);
535 	if (rlen < 0) {
536 		DRM_ERROR("failed to read link rate. rlen=%zd\n", rlen);
537 		return rlen;
538 	}
539 
540 	if (!is_link_rate_valid(bp)) {
541 		DRM_ERROR("invalid link rate = 0x%x\n", bp);
542 		return -EINVAL;
543 	}
544 
545 	link->request.test_link_rate = bp;
546 	DRM_DEBUG_DP("link rate = 0x%x\n", link->request.test_link_rate);
547 
548 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_LANE_COUNT, &bp);
549 	if (rlen < 0) {
550 		DRM_ERROR("failed to read lane count. rlen=%zd\n", rlen);
551 		return rlen;
552 	}
553 	bp &= DP_MAX_LANE_COUNT_MASK;
554 
555 	if (!is_lane_count_valid(bp)) {
556 		DRM_ERROR("invalid lane count = 0x%x\n", bp);
557 		return -EINVAL;
558 	}
559 
560 	link->request.test_lane_count = bp;
561 	DRM_DEBUG_DP("lane count = 0x%x\n", link->request.test_lane_count);
562 	return 0;
563 }
564 
565 /**
566  * dp_link_parse_phy_test_params() - parses the phy link parameters
567  * @link: Display Port Driver data
568  *
569  * Parses the DPCD (Byte 0x248) for the DP PHY link pattern that is being
570  * requested.
571  */
572 static int dp_link_parse_phy_test_params(struct dp_link_private *link)
573 {
574 	u8 data;
575 	ssize_t rlen;
576 
577 	rlen = drm_dp_dpcd_readb(link->aux, DP_PHY_TEST_PATTERN,
578 					&data);
579 	if (rlen < 0) {
580 		DRM_ERROR("failed to read phy link pattern. rlen=%zd\n", rlen);
581 		return rlen;
582 	}
583 
584 	link->dp_link.phy_params.phy_test_pattern_sel = data & 0x07;
585 
586 	DRM_DEBUG_DP("phy_test_pattern_sel = 0x%x\n", data);
587 
588 	switch (data) {
589 	case DP_PHY_TEST_PATTERN_SEL_MASK:
590 	case DP_PHY_TEST_PATTERN_NONE:
591 	case DP_PHY_TEST_PATTERN_D10_2:
592 	case DP_PHY_TEST_PATTERN_ERROR_COUNT:
593 	case DP_PHY_TEST_PATTERN_PRBS7:
594 	case DP_PHY_TEST_PATTERN_80BIT_CUSTOM:
595 	case DP_PHY_TEST_PATTERN_CP2520:
596 		return 0;
597 	default:
598 		return -EINVAL;
599 	}
600 }
601 
602 /**
603  * dp_link_is_video_audio_test_requested() - checks for audio/video link request
604  * @link: link requested by the sink
605  *
606  * Returns true if the requested link is a permitted audio/video link.
607  */
608 static bool dp_link_is_video_audio_test_requested(u32 link)
609 {
610 	u8 video_audio_test = (DP_TEST_LINK_VIDEO_PATTERN |
611 				DP_TEST_LINK_AUDIO_PATTERN |
612 				DP_TEST_LINK_AUDIO_DISABLED_VIDEO);
613 
614 	return ((link & video_audio_test) &&
615 		!(link & ~video_audio_test));
616 }
617 
618 /**
619  * dp_link_parse_request() - parses link request parameters from sink
620  * @link: Display Port Driver data
621  *
622  * Parses the DPCD to check if an automated link is requested (Byte 0x201),
623  * and what type of link automation is being requested (Byte 0x218).
624  */
625 static int dp_link_parse_request(struct dp_link_private *link)
626 {
627 	int ret = 0;
628 	u8 data;
629 	ssize_t rlen;
630 
631 	/**
632 	 * Read the device service IRQ vector (Byte 0x201) to determine
633 	 * whether an automated link has been requested by the sink.
634 	 */
635 	rlen = drm_dp_dpcd_readb(link->aux,
636 				DP_DEVICE_SERVICE_IRQ_VECTOR, &data);
637 	if (rlen < 0) {
638 		DRM_ERROR("aux read failed. rlen=%zd\n", rlen);
639 		return rlen;
640 	}
641 
642 	DRM_DEBUG_DP("device service irq vector = 0x%x\n", data);
643 
644 	if (!(data & DP_AUTOMATED_TEST_REQUEST)) {
645 		DRM_DEBUG_DP("no test requested\n");
646 		return 0;
647 	}
648 
649 	/**
650 	 * Read the link request byte (Byte 0x218) to determine what type
651 	 * of automated link has been requested by the sink.
652 	 */
653 	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_REQUEST, &data);
654 	if (rlen < 0) {
655 		DRM_ERROR("aux read failed. rlen=%zd\n", rlen);
656 		return rlen;
657 	}
658 
659 	if (!data || (data == DP_TEST_LINK_FAUX_PATTERN)) {
660 		DRM_DEBUG_DP("link 0x%x not supported\n", data);
661 		goto end;
662 	}
663 
664 	DRM_DEBUG_DP("Test:(0x%x) requested\n", data);
665 	link->request.test_requested = data;
666 	if (link->request.test_requested == DP_TEST_LINK_PHY_TEST_PATTERN) {
667 		ret = dp_link_parse_phy_test_params(link);
668 		if (ret)
669 			goto end;
670 		ret = dp_link_parse_link_training_params(link);
671 		if (ret)
672 			goto end;
673 	}
674 
675 	if (link->request.test_requested == DP_TEST_LINK_TRAINING) {
676 		ret = dp_link_parse_link_training_params(link);
677 		if (ret)
678 			goto end;
679 	}
680 
681 	if (dp_link_is_video_audio_test_requested(
682 			link->request.test_requested)) {
683 		ret = dp_link_parse_video_pattern_params(link);
684 		if (ret)
685 			goto end;
686 
687 		ret = dp_link_parse_audio_pattern_params(link);
688 	}
689 end:
690 	/*
691 	 * Send a DP_TEST_ACK if all link parameters are valid, otherwise send
692 	 * a DP_TEST_NAK.
693 	 */
694 	if (ret) {
695 		link->dp_link.test_response = DP_TEST_NAK;
696 	} else {
697 		if (link->request.test_requested != DP_TEST_LINK_EDID_READ)
698 			link->dp_link.test_response = DP_TEST_ACK;
699 		else
700 			link->dp_link.test_response =
701 				DP_TEST_EDID_CHECKSUM_WRITE;
702 	}
703 
704 	return ret;
705 }
706 
707 /**
708  * dp_link_parse_sink_count() - parses the sink count
709  * @dp_link: pointer to link module data
710  *
711  * Parses the DPCD to check if there is an update to the sink count
712  * (Byte 0x200), and whether all the sink devices connected have Content
713  * Protection enabled.
714  */
715 static int dp_link_parse_sink_count(struct dp_link *dp_link)
716 {
717 	ssize_t rlen;
718 	bool cp_ready;
719 
720 	struct dp_link_private *link = container_of(dp_link,
721 			struct dp_link_private, dp_link);
722 
723 	rlen = drm_dp_dpcd_readb(link->aux, DP_SINK_COUNT,
724 				 &link->dp_link.sink_count);
725 	if (rlen < 0) {
726 		DRM_ERROR("sink count read failed. rlen=%zd\n", rlen);
727 		return rlen;
728 	}
729 
730 	cp_ready = link->dp_link.sink_count & DP_SINK_CP_READY;
731 
732 	link->dp_link.sink_count =
733 		DP_GET_SINK_COUNT(link->dp_link.sink_count);
734 
735 	DRM_DEBUG_DP("sink_count = 0x%x, cp_ready = 0x%x\n",
736 		link->dp_link.sink_count, cp_ready);
737 	return 0;
738 }
739 
740 static void dp_link_parse_sink_status_field(struct dp_link_private *link)
741 {
742 	int len = 0;
743 
744 	link->prev_sink_count = link->dp_link.sink_count;
745 	dp_link_parse_sink_count(&link->dp_link);
746 
747 	len = drm_dp_dpcd_read_link_status(link->aux,
748 		link->link_status);
749 	if (len < DP_LINK_STATUS_SIZE)
750 		DRM_ERROR("DP link status read failed\n");
751 	dp_link_parse_request(link);
752 }
753 
754 /**
755  * dp_link_process_link_training_request() - processes new training requests
756  * @link: Display Port link data
757  *
758  * This function will handle new link training requests that are initiated by
759  * the sink. In particular, it will update the requested lane count and link
760  * rate, and then trigger the link retraining procedure.
761  *
762  * The function will return 0 if a link training request has been processed,
763  * otherwise it will return -EINVAL.
764  */
765 static int dp_link_process_link_training_request(struct dp_link_private *link)
766 {
767 	if (link->request.test_requested != DP_TEST_LINK_TRAINING)
768 		return -EINVAL;
769 
770 	DRM_DEBUG_DP("Test:0x%x link rate = 0x%x, lane count = 0x%x\n",
771 			DP_TEST_LINK_TRAINING,
772 			link->request.test_link_rate,
773 			link->request.test_lane_count);
774 
775 	link->dp_link.link_params.num_lanes = link->request.test_lane_count;
776 	link->dp_link.link_params.rate =
777 		drm_dp_bw_code_to_link_rate(link->request.test_link_rate);
778 
779 	return 0;
780 }
781 
782 bool dp_link_send_test_response(struct dp_link *dp_link)
783 {
784 	struct dp_link_private *link = NULL;
785 	int ret = 0;
786 
787 	if (!dp_link) {
788 		DRM_ERROR("invalid input\n");
789 		return false;
790 	}
791 
792 	link = container_of(dp_link, struct dp_link_private, dp_link);
793 
794 	ret = drm_dp_dpcd_writeb(link->aux, DP_TEST_RESPONSE,
795 			dp_link->test_response);
796 
797 	return ret == 1;
798 }
799 
800 int dp_link_psm_config(struct dp_link *dp_link,
801 			      struct dp_link_info *link_info, bool enable)
802 {
803 	struct dp_link_private *link = NULL;
804 	int ret = 0;
805 
806 	if (!dp_link) {
807 		DRM_ERROR("invalid params\n");
808 		return -EINVAL;
809 	}
810 
811 	link = container_of(dp_link, struct dp_link_private, dp_link);
812 
813 	mutex_lock(&link->psm_mutex);
814 	if (enable)
815 		ret = dp_aux_link_power_down(link->aux, link_info);
816 	else
817 		ret = dp_aux_link_power_up(link->aux, link_info);
818 
819 	if (ret)
820 		DRM_ERROR("Failed to %s low power mode\n", enable ?
821 							"enter" : "exit");
822 	else
823 		dp_link->psm_enabled = enable;
824 
825 	mutex_unlock(&link->psm_mutex);
826 	return ret;
827 }
828 
829 bool dp_link_send_edid_checksum(struct dp_link *dp_link, u8 checksum)
830 {
831 	struct dp_link_private *link = NULL;
832 	int ret = 0;
833 
834 	if (!dp_link) {
835 		DRM_ERROR("invalid input\n");
836 		return false;
837 	}
838 
839 	link = container_of(dp_link, struct dp_link_private, dp_link);
840 
841 	ret = drm_dp_dpcd_writeb(link->aux, DP_TEST_EDID_CHECKSUM,
842 						checksum);
843 	return ret == 1;
844 }
845 
846 static void dp_link_parse_vx_px(struct dp_link_private *link)
847 {
848 	DRM_DEBUG_DP("vx: 0=%d, 1=%d, 2=%d, 3=%d\n",
849 		drm_dp_get_adjust_request_voltage(link->link_status, 0),
850 		drm_dp_get_adjust_request_voltage(link->link_status, 1),
851 		drm_dp_get_adjust_request_voltage(link->link_status, 2),
852 		drm_dp_get_adjust_request_voltage(link->link_status, 3));
853 
854 	DRM_DEBUG_DP("px: 0=%d, 1=%d, 2=%d, 3=%d\n",
855 		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 0),
856 		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 1),
857 		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 2),
858 		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 3));
859 
860 	/**
861 	 * Update the voltage and pre-emphasis levels as per DPCD request
862 	 * vector.
863 	 */
864 	DRM_DEBUG_DP("Current: v_level = 0x%x, p_level = 0x%x\n",
865 			link->dp_link.phy_params.v_level,
866 			link->dp_link.phy_params.p_level);
867 	link->dp_link.phy_params.v_level =
868 		drm_dp_get_adjust_request_voltage(link->link_status, 0);
869 	link->dp_link.phy_params.p_level =
870 		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 0);
871 
872 	link->dp_link.phy_params.p_level >>= DP_TRAIN_PRE_EMPHASIS_SHIFT;
873 
874 	DRM_DEBUG_DP("Requested: v_level = 0x%x, p_level = 0x%x\n",
875 			link->dp_link.phy_params.v_level,
876 			link->dp_link.phy_params.p_level);
877 }
878 
879 /**
880  * dp_link_process_phy_test_pattern_request() - process new phy link requests
881  * @link: Display Port Driver data
882  *
883  * This function will handle new phy link pattern requests that are initiated
884  * by the sink. The function will return 0 if a phy link pattern has been
885  * processed, otherwise it will return -EINVAL.
886  */
887 static int dp_link_process_phy_test_pattern_request(
888 		struct dp_link_private *link)
889 {
890 	if (!(link->request.test_requested & DP_TEST_LINK_PHY_TEST_PATTERN)) {
891 		DRM_DEBUG_DP("no phy test\n");
892 		return -EINVAL;
893 	}
894 
895 	if (!is_link_rate_valid(link->request.test_link_rate) ||
896 		!is_lane_count_valid(link->request.test_lane_count)) {
897 		DRM_ERROR("Invalid: link rate = 0x%x,lane count = 0x%x\n",
898 				link->request.test_link_rate,
899 				link->request.test_lane_count);
900 		return -EINVAL;
901 	}
902 
903 	DRM_DEBUG_DP("Current: rate = 0x%x, lane count = 0x%x\n",
904 			link->dp_link.link_params.rate,
905 			link->dp_link.link_params.num_lanes);
906 
907 	DRM_DEBUG_DP("Requested: rate = 0x%x, lane count = 0x%x\n",
908 			link->request.test_link_rate,
909 			link->request.test_lane_count);
910 
911 	link->dp_link.link_params.num_lanes = link->request.test_lane_count;
912 	link->dp_link.link_params.rate =
913 		drm_dp_bw_code_to_link_rate(link->request.test_link_rate);
914 
915 	dp_link_parse_vx_px(link);
916 
917 	return 0;
918 }
919 
920 static u8 get_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
921 {
922 	return link_status[r - DP_LANE0_1_STATUS];
923 }
924 
925 /**
926  * dp_link_process_link_status_update() - processes link status updates
927  * @link: Display Port link module data
928  *
929  * This function will check for changes in the link status, e.g. clock
930  * recovery done on all lanes, and trigger link training if there is a
931  * failure/error on the link.
932  *
933  * The function will return 0 if the a link status update has been processed,
934  * otherwise it will return -EINVAL.
935  */
936 static int dp_link_process_link_status_update(struct dp_link_private *link)
937 {
938        bool channel_eq_done = drm_dp_channel_eq_ok(link->link_status,
939                        link->dp_link.link_params.num_lanes);
940 
941        bool clock_recovery_done = drm_dp_clock_recovery_ok(link->link_status,
942                        link->dp_link.link_params.num_lanes);
943 
944        DRM_DEBUG_DP("channel_eq_done = %d, clock_recovery_done = %d\n",
945                         channel_eq_done, clock_recovery_done);
946 
947        if (channel_eq_done && clock_recovery_done)
948                return -EINVAL;
949 
950 
951        return 0;
952 }
953 
954 /**
955  * dp_link_process_ds_port_status_change() - process port status changes
956  * @link: Display Port Driver data
957  *
958  * This function will handle downstream port updates that are initiated by
959  * the sink. If the downstream port status has changed, the EDID is read via
960  * AUX.
961  *
962  * The function will return 0 if a downstream port update has been
963  * processed, otherwise it will return -EINVAL.
964  */
965 static int dp_link_process_ds_port_status_change(struct dp_link_private *link)
966 {
967 	if (get_link_status(link->link_status, DP_LANE_ALIGN_STATUS_UPDATED) &
968 					DP_DOWNSTREAM_PORT_STATUS_CHANGED)
969 		goto reset;
970 
971 	if (link->prev_sink_count == link->dp_link.sink_count)
972 		return -EINVAL;
973 
974 reset:
975 	/* reset prev_sink_count */
976 	link->prev_sink_count = link->dp_link.sink_count;
977 
978 	return 0;
979 }
980 
981 static bool dp_link_is_video_pattern_requested(struct dp_link_private *link)
982 {
983 	return (link->request.test_requested & DP_TEST_LINK_VIDEO_PATTERN)
984 		&& !(link->request.test_requested &
985 		DP_TEST_LINK_AUDIO_DISABLED_VIDEO);
986 }
987 
988 static bool dp_link_is_audio_pattern_requested(struct dp_link_private *link)
989 {
990 	return (link->request.test_requested & DP_TEST_LINK_AUDIO_PATTERN);
991 }
992 
993 static void dp_link_reset_data(struct dp_link_private *link)
994 {
995 	link->request = (const struct dp_link_request){ 0 };
996 	link->dp_link.test_video = (const struct dp_link_test_video){ 0 };
997 	link->dp_link.test_video.test_bit_depth = DP_TEST_BIT_DEPTH_UNKNOWN;
998 	link->dp_link.test_audio = (const struct dp_link_test_audio){ 0 };
999 	link->dp_link.phy_params.phy_test_pattern_sel = 0;
1000 	link->dp_link.sink_request = 0;
1001 	link->dp_link.test_response = 0;
1002 }
1003 
1004 /**
1005  * dp_link_process_request() - handle HPD IRQ transition to HIGH
1006  * @dp_link: pointer to link module data
1007  *
1008  * This function will handle the HPD IRQ state transitions from LOW to HIGH
1009  * (including cases when there are back to back HPD IRQ HIGH) indicating
1010  * the start of a new link training request or sink status update.
1011  */
1012 int dp_link_process_request(struct dp_link *dp_link)
1013 {
1014 	int ret = 0;
1015 	struct dp_link_private *link;
1016 
1017 	if (!dp_link) {
1018 		DRM_ERROR("invalid input\n");
1019 		return -EINVAL;
1020 	}
1021 
1022 	link = container_of(dp_link, struct dp_link_private, dp_link);
1023 
1024 	dp_link_reset_data(link);
1025 
1026 	dp_link_parse_sink_status_field(link);
1027 
1028 	if (link->request.test_requested == DP_TEST_LINK_EDID_READ) {
1029 		dp_link->sink_request |= DP_TEST_LINK_EDID_READ;
1030 	} else if (!dp_link_process_ds_port_status_change(link)) {
1031 		dp_link->sink_request |= DS_PORT_STATUS_CHANGED;
1032 	} else if (!dp_link_process_link_training_request(link)) {
1033 		dp_link->sink_request |= DP_TEST_LINK_TRAINING;
1034 	} else if (!dp_link_process_phy_test_pattern_request(link)) {
1035 		dp_link->sink_request |= DP_TEST_LINK_PHY_TEST_PATTERN;
1036 	} else {
1037 		ret = dp_link_process_link_status_update(link);
1038 		if (!ret) {
1039 			dp_link->sink_request |= DP_LINK_STATUS_UPDATED;
1040 		} else {
1041 			if (dp_link_is_video_pattern_requested(link)) {
1042 				ret = 0;
1043 				dp_link->sink_request |= DP_TEST_LINK_VIDEO_PATTERN;
1044 			}
1045 			if (dp_link_is_audio_pattern_requested(link)) {
1046 				dp_link->sink_request |= DP_TEST_LINK_AUDIO_PATTERN;
1047 				ret = -EINVAL;
1048 			}
1049 		}
1050 	}
1051 
1052 	DRM_DEBUG_DP("sink request=%#x", dp_link->sink_request);
1053 	return ret;
1054 }
1055 
1056 int dp_link_get_colorimetry_config(struct dp_link *dp_link)
1057 {
1058 	u32 cc;
1059 	struct dp_link_private *link;
1060 
1061 	if (!dp_link) {
1062 		DRM_ERROR("invalid input\n");
1063 		return -EINVAL;
1064 	}
1065 
1066 	link = container_of(dp_link, struct dp_link_private, dp_link);
1067 
1068 	/*
1069 	 * Unless a video pattern CTS test is ongoing, use RGB_VESA
1070 	 * Only RGB_VESA and RGB_CEA supported for now
1071 	 */
1072 	if (dp_link_is_video_pattern_requested(link))
1073 		cc = link->dp_link.test_video.test_dyn_range;
1074 	else
1075 		cc = DP_TEST_DYNAMIC_RANGE_VESA;
1076 
1077 	return cc;
1078 }
1079 
1080 int dp_link_adjust_levels(struct dp_link *dp_link, u8 *link_status)
1081 {
1082 	int i;
1083 	int v_max = 0, p_max = 0;
1084 
1085 	if (!dp_link) {
1086 		DRM_ERROR("invalid input\n");
1087 		return -EINVAL;
1088 	}
1089 
1090 	/* use the max level across lanes */
1091 	for (i = 0; i < dp_link->link_params.num_lanes; i++) {
1092 		u8 data_v = drm_dp_get_adjust_request_voltage(link_status, i);
1093 		u8 data_p = drm_dp_get_adjust_request_pre_emphasis(link_status,
1094 									 i);
1095 		DRM_DEBUG_DP("lane=%d req_vol_swing=%d req_pre_emphasis=%d\n",
1096 				i, data_v, data_p);
1097 		if (v_max < data_v)
1098 			v_max = data_v;
1099 		if (p_max < data_p)
1100 			p_max = data_p;
1101 	}
1102 
1103 	dp_link->phy_params.v_level = v_max >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
1104 	dp_link->phy_params.p_level = p_max >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
1105 
1106 	/**
1107 	 * Adjust the voltage swing and pre-emphasis level combination to within
1108 	 * the allowable range.
1109 	 */
1110 	if (dp_link->phy_params.v_level > DP_TRAIN_VOLTAGE_SWING_MAX) {
1111 		DRM_DEBUG_DP("Requested vSwingLevel=%d, change to %d\n",
1112 			dp_link->phy_params.v_level,
1113 			DP_TRAIN_VOLTAGE_SWING_MAX);
1114 		dp_link->phy_params.v_level = DP_TRAIN_VOLTAGE_SWING_MAX;
1115 	}
1116 
1117 	if (dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_MAX) {
1118 		DRM_DEBUG_DP("Requested preEmphasisLevel=%d, change to %d\n",
1119 			dp_link->phy_params.p_level,
1120 			DP_TRAIN_PRE_EMPHASIS_MAX);
1121 		dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_MAX;
1122 	}
1123 
1124 	if ((dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_LVL_1)
1125 		&& (dp_link->phy_params.v_level ==
1126 			DP_TRAIN_VOLTAGE_SWING_LVL_2)) {
1127 		DRM_DEBUG_DP("Requested preEmphasisLevel=%d, change to %d\n",
1128 			dp_link->phy_params.p_level,
1129 			DP_TRAIN_PRE_EMPHASIS_LVL_1);
1130 		dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_LVL_1;
1131 	}
1132 
1133 	DRM_DEBUG_DP("adjusted: v_level=%d, p_level=%d\n",
1134 		dp_link->phy_params.v_level, dp_link->phy_params.p_level);
1135 
1136 	return 0;
1137 }
1138 
1139 void dp_link_reset_phy_params_vx_px(struct dp_link *dp_link)
1140 {
1141 	dp_link->phy_params.v_level = 0;
1142 	dp_link->phy_params.p_level = 0;
1143 }
1144 
1145 u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp)
1146 {
1147 	u32 tbd;
1148 
1149 	/*
1150 	 * Few simplistic rules and assumptions made here:
1151 	 *    1. Test bit depth is bit depth per color component
1152 	 *    2. Assume 3 color components
1153 	 */
1154 	switch (bpp) {
1155 	case 18:
1156 		tbd = DP_TEST_BIT_DEPTH_6;
1157 		break;
1158 	case 24:
1159 		tbd = DP_TEST_BIT_DEPTH_8;
1160 		break;
1161 	case 30:
1162 		tbd = DP_TEST_BIT_DEPTH_10;
1163 		break;
1164 	default:
1165 		tbd = DP_TEST_BIT_DEPTH_UNKNOWN;
1166 		break;
1167 	}
1168 
1169 	if (tbd != DP_TEST_BIT_DEPTH_UNKNOWN)
1170 		tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT);
1171 
1172 	return tbd;
1173 }
1174 
1175 struct dp_link *dp_link_get(struct device *dev, struct drm_dp_aux *aux)
1176 {
1177 	struct dp_link_private *link;
1178 	struct dp_link *dp_link;
1179 
1180 	if (!dev || !aux) {
1181 		DRM_ERROR("invalid input\n");
1182 		return ERR_PTR(-EINVAL);
1183 	}
1184 
1185 	link = devm_kzalloc(dev, sizeof(*link), GFP_KERNEL);
1186 	if (!link)
1187 		return ERR_PTR(-ENOMEM);
1188 
1189 	link->dev   = dev;
1190 	link->aux   = aux;
1191 
1192 	mutex_init(&link->psm_mutex);
1193 	dp_link = &link->dp_link;
1194 
1195 	return dp_link;
1196 }
1197