Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
   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
  15enum 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
  25enum audio_pattern_type {
  26	AUDIO_TEST_PATTERN_OPERATOR_DEFINED	= 0x00,
  27	AUDIO_TEST_PATTERN_SAWTOOTH		= 0x01,
  28};
  29
  30struct dp_link_request {
  31	u32 test_requested;
  32	u32 test_link_rate;
  33	u32 test_lane_count;
  34};
  35
  36struct dp_link_private {
  37	u32 prev_sink_count;
  38	struct device *dev;
  39	struct drm_device *drm_dev;
  40	struct drm_dp_aux *aux;
  41	struct dp_link dp_link;
  42
  43	struct dp_link_request request;
  44	struct mutex psm_mutex;
  45	u8 link_status[DP_LINK_STATUS_SIZE];
  46};
  47
  48static int dp_aux_link_power_up(struct drm_dp_aux *aux,
  49					struct dp_link_info *link)
  50{
  51	u8 value;
  52	ssize_t len;
  53	int i;
  54
  55	if (link->revision < 0x11)
  56		return 0;
  57
  58	len = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
  59	if (len < 0)
  60		return len;
  61
  62	value &= ~DP_SET_POWER_MASK;
  63	value |= DP_SET_POWER_D0;
  64
  65	/* retry for 1ms to give the sink time to wake up */
  66	for (i = 0; i < 3; i++) {
  67		len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
  68		usleep_range(1000, 2000);
  69		if (len == 1)
  70			break;
  71	}
  72
  73	return 0;
  74}
  75
  76static int dp_aux_link_power_down(struct drm_dp_aux *aux,
  77					struct dp_link_info *link)
  78{
  79	u8 value;
  80	int err;
  81
  82	if (link->revision < 0x11)
  83		return 0;
  84
  85	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
  86	if (err < 0)
  87		return err;
  88
  89	value &= ~DP_SET_POWER_MASK;
  90	value |= DP_SET_POWER_D3;
  91
  92	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
  93	if (err < 0)
  94		return err;
  95
  96	return 0;
  97}
  98
  99static int dp_link_get_period(struct dp_link_private *link, int const addr)
 100{
 101	int ret = 0;
 102	u8 data;
 103	u32 const max_audio_period = 0xA;
 104
 105	/* TEST_AUDIO_PERIOD_CH_XX */
 106	if (drm_dp_dpcd_readb(link->aux, addr, &data) < 0) {
 107		DRM_ERROR("failed to read test_audio_period (0x%x)\n", addr);
 108		ret = -EINVAL;
 109		goto exit;
 110	}
 111
 112	/* Period - Bits 3:0 */
 113	data = data & 0xF;
 114	if ((int)data > max_audio_period) {
 115		DRM_ERROR("invalid test_audio_period_ch_1 = 0x%x\n", data);
 116		ret = -EINVAL;
 117		goto exit;
 118	}
 119
 120	ret = data;
 121exit:
 122	return ret;
 123}
 124
 125static int dp_link_parse_audio_channel_period(struct dp_link_private *link)
 126{
 127	int ret = 0;
 128	struct dp_link_test_audio *req = &link->dp_link.test_audio;
 129
 130	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH1);
 131	if (ret == -EINVAL)
 132		goto exit;
 133
 134	req->test_audio_period_ch_1 = ret;
 135	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_1 = 0x%x\n", ret);
 136
 137	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH2);
 138	if (ret == -EINVAL)
 139		goto exit;
 140
 141	req->test_audio_period_ch_2 = ret;
 142	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_2 = 0x%x\n", ret);
 143
 144	/* TEST_AUDIO_PERIOD_CH_3 (Byte 0x275) */
 145	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH3);
 146	if (ret == -EINVAL)
 147		goto exit;
 148
 149	req->test_audio_period_ch_3 = ret;
 150	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_3 = 0x%x\n", ret);
 151
 152	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH4);
 153	if (ret == -EINVAL)
 154		goto exit;
 155
 156	req->test_audio_period_ch_4 = ret;
 157	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_4 = 0x%x\n", ret);
 158
 159	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH5);
 160	if (ret == -EINVAL)
 161		goto exit;
 162
 163	req->test_audio_period_ch_5 = ret;
 164	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_5 = 0x%x\n", ret);
 165
 166	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH6);
 167	if (ret == -EINVAL)
 168		goto exit;
 169
 170	req->test_audio_period_ch_6 = ret;
 171	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_6 = 0x%x\n", ret);
 172
 173	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH7);
 174	if (ret == -EINVAL)
 175		goto exit;
 176
 177	req->test_audio_period_ch_7 = ret;
 178	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_7 = 0x%x\n", ret);
 179
 180	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH8);
 181	if (ret == -EINVAL)
 182		goto exit;
 183
 184	req->test_audio_period_ch_8 = ret;
 185	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_8 = 0x%x\n", ret);
 186exit:
 187	return ret;
 188}
 189
 190static int dp_link_parse_audio_pattern_type(struct dp_link_private *link)
 191{
 192	int ret = 0;
 193	u8 data;
 194	ssize_t rlen;
 195	int const max_audio_pattern_type = 0x1;
 196
 197	rlen = drm_dp_dpcd_readb(link->aux,
 198				DP_TEST_AUDIO_PATTERN_TYPE, &data);
 199	if (rlen < 0) {
 200		DRM_ERROR("failed to read link audio mode. rlen=%zd\n", rlen);
 201		return rlen;
 202	}
 203
 204	/* Audio Pattern Type - Bits 7:0 */
 205	if ((int)data > max_audio_pattern_type) {
 206		DRM_ERROR("invalid audio pattern type = 0x%x\n", data);
 207		ret = -EINVAL;
 208		goto exit;
 209	}
 210
 211	link->dp_link.test_audio.test_audio_pattern_type = data;
 212	drm_dbg_dp(link->drm_dev, "audio pattern type = 0x%x\n", data);
 213exit:
 214	return ret;
 215}
 216
 217static int dp_link_parse_audio_mode(struct dp_link_private *link)
 218{
 219	int ret = 0;
 220	u8 data;
 221	ssize_t rlen;
 222	int const max_audio_sampling_rate = 0x6;
 223	int const max_audio_channel_count = 0x8;
 224	int sampling_rate = 0x0;
 225	int channel_count = 0x0;
 226
 227	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_AUDIO_MODE, &data);
 228	if (rlen < 0) {
 229		DRM_ERROR("failed to read link audio mode. rlen=%zd\n", rlen);
 230		return rlen;
 231	}
 232
 233	/* Sampling Rate - Bits 3:0 */
 234	sampling_rate = data & 0xF;
 235	if (sampling_rate > max_audio_sampling_rate) {
 236		DRM_ERROR("sampling rate (0x%x) greater than max (0x%x)\n",
 237				sampling_rate, max_audio_sampling_rate);
 238		ret = -EINVAL;
 239		goto exit;
 240	}
 241
 242	/* Channel Count - Bits 7:4 */
 243	channel_count = ((data & 0xF0) >> 4) + 1;
 244	if (channel_count > max_audio_channel_count) {
 245		DRM_ERROR("channel_count (0x%x) greater than max (0x%x)\n",
 246				channel_count, max_audio_channel_count);
 247		ret = -EINVAL;
 248		goto exit;
 249	}
 250
 251	link->dp_link.test_audio.test_audio_sampling_rate = sampling_rate;
 252	link->dp_link.test_audio.test_audio_channel_count = channel_count;
 253	drm_dbg_dp(link->drm_dev,
 254			"sampling_rate = 0x%x, channel_count = 0x%x\n",
 255			sampling_rate, channel_count);
 256exit:
 257	return ret;
 258}
 259
 260static int dp_link_parse_audio_pattern_params(struct dp_link_private *link)
 261{
 262	int ret = 0;
 263
 264	ret = dp_link_parse_audio_mode(link);
 265	if (ret)
 266		goto exit;
 267
 268	ret = dp_link_parse_audio_pattern_type(link);
 269	if (ret)
 270		goto exit;
 271
 272	ret = dp_link_parse_audio_channel_period(link);
 273
 274exit:
 275	return ret;
 276}
 277
 278static bool dp_link_is_video_pattern_valid(u32 pattern)
 279{
 280	switch (pattern) {
 281	case DP_NO_TEST_PATTERN:
 282	case DP_COLOR_RAMP:
 283	case DP_BLACK_AND_WHITE_VERTICAL_LINES:
 284	case DP_COLOR_SQUARE:
 285		return true;
 286	default:
 287		return false;
 288	}
 289}
 290
 291/**
 292 * dp_link_is_bit_depth_valid() - validates the bit depth requested
 293 * @tbd: bit depth requested by the sink
 294 *
 295 * Returns true if the requested bit depth is supported.
 296 */
 297static bool dp_link_is_bit_depth_valid(u32 tbd)
 298{
 299	/* DP_TEST_VIDEO_PATTERN_NONE is treated as invalid */
 300	switch (tbd) {
 301	case DP_TEST_BIT_DEPTH_6:
 302	case DP_TEST_BIT_DEPTH_8:
 303	case DP_TEST_BIT_DEPTH_10:
 304		return true;
 305	default:
 306		return false;
 307	}
 308}
 309
 310static int dp_link_parse_timing_params1(struct dp_link_private *link,
 311					int addr, int len, u32 *val)
 312{
 313	u8 bp[2];
 314	int rlen;
 315
 316	if (len != 2)
 317		return -EINVAL;
 318
 319	/* Read the requested video link pattern (Byte 0x221). */
 320	rlen = drm_dp_dpcd_read(link->aux, addr, bp, len);
 321	if (rlen < len) {
 322		DRM_ERROR("failed to read 0x%x\n", addr);
 323		return -EINVAL;
 324	}
 325
 326	*val = bp[1] | (bp[0] << 8);
 327
 328	return 0;
 329}
 330
 331static int dp_link_parse_timing_params2(struct dp_link_private *link,
 332					int addr, int len,
 333					u32 *val1, u32 *val2)
 334{
 335	u8 bp[2];
 336	int rlen;
 337
 338	if (len != 2)
 339		return -EINVAL;
 340
 341	/* Read the requested video link pattern (Byte 0x221). */
 342	rlen = drm_dp_dpcd_read(link->aux, addr, bp, len);
 343	if (rlen < len) {
 344		DRM_ERROR("failed to read 0x%x\n", addr);
 345		return -EINVAL;
 346	}
 347
 348	*val1 = (bp[0] & BIT(7)) >> 7;
 349	*val2 = bp[1] | ((bp[0] & 0x7F) << 8);
 350
 351	return 0;
 352}
 353
 354static int dp_link_parse_timing_params3(struct dp_link_private *link,
 355					int addr, u32 *val)
 356{
 357	u8 bp;
 358	u32 len = 1;
 359	int rlen;
 360
 361	rlen = drm_dp_dpcd_read(link->aux, addr, &bp, len);
 362	if (rlen < 1) {
 363		DRM_ERROR("failed to read 0x%x\n", addr);
 364		return -EINVAL;
 365	}
 366	*val = bp;
 367
 368	return 0;
 369}
 370
 371/**
 372 * dp_link_parse_video_pattern_params() - parses video pattern parameters from DPCD
 373 * @link: Display Port Driver data
 374 *
 375 * Returns 0 if it successfully parses the video link pattern and the link
 376 * bit depth requested by the sink and, and if the values parsed are valid.
 377 */
 378static int dp_link_parse_video_pattern_params(struct dp_link_private *link)
 379{
 380	int ret = 0;
 381	ssize_t rlen;
 382	u8 bp;
 383
 384	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_PATTERN, &bp);
 385	if (rlen < 0) {
 386		DRM_ERROR("failed to read link video pattern. rlen=%zd\n",
 387			rlen);
 388		return rlen;
 389	}
 390
 391	if (!dp_link_is_video_pattern_valid(bp)) {
 392		DRM_ERROR("invalid link video pattern = 0x%x\n", bp);
 393		ret = -EINVAL;
 394		return ret;
 395	}
 396
 397	link->dp_link.test_video.test_video_pattern = bp;
 398
 399	/* Read the requested color bit depth and dynamic range (Byte 0x232) */
 400	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_MISC0, &bp);
 401	if (rlen < 0) {
 402		DRM_ERROR("failed to read link bit depth. rlen=%zd\n", rlen);
 403		return rlen;
 404	}
 405
 406	/* Dynamic Range */
 407	link->dp_link.test_video.test_dyn_range =
 408			(bp & DP_TEST_DYNAMIC_RANGE_CEA);
 409
 410	/* Color bit depth */
 411	bp &= DP_TEST_BIT_DEPTH_MASK;
 412	if (!dp_link_is_bit_depth_valid(bp)) {
 413		DRM_ERROR("invalid link bit depth = 0x%x\n", bp);
 414		ret = -EINVAL;
 415		return ret;
 416	}
 417
 418	link->dp_link.test_video.test_bit_depth = bp;
 419
 420	/* resolution timing params */
 421	ret = dp_link_parse_timing_params1(link, DP_TEST_H_TOTAL_HI, 2,
 422			&link->dp_link.test_video.test_h_total);
 423	if (ret) {
 424		DRM_ERROR("failed to parse test_htotal(DP_TEST_H_TOTAL_HI)\n");
 425		return ret;
 426	}
 427
 428	ret = dp_link_parse_timing_params1(link, DP_TEST_V_TOTAL_HI, 2,
 429			&link->dp_link.test_video.test_v_total);
 430	if (ret) {
 431		DRM_ERROR("failed to parse test_v_total(DP_TEST_V_TOTAL_HI)\n");
 432		return ret;
 433	}
 434
 435	ret = dp_link_parse_timing_params1(link, DP_TEST_H_START_HI, 2,
 436			&link->dp_link.test_video.test_h_start);
 437	if (ret) {
 438		DRM_ERROR("failed to parse test_h_start(DP_TEST_H_START_HI)\n");
 439		return ret;
 440	}
 441
 442	ret = dp_link_parse_timing_params1(link, DP_TEST_V_START_HI, 2,
 443			&link->dp_link.test_video.test_v_start);
 444	if (ret) {
 445		DRM_ERROR("failed to parse test_v_start(DP_TEST_V_START_HI)\n");
 446		return ret;
 447	}
 448
 449	ret = dp_link_parse_timing_params2(link, DP_TEST_HSYNC_HI, 2,
 450			&link->dp_link.test_video.test_hsync_pol,
 451			&link->dp_link.test_video.test_hsync_width);
 452	if (ret) {
 453		DRM_ERROR("failed to parse (DP_TEST_HSYNC_HI)\n");
 454		return ret;
 455	}
 456
 457	ret = dp_link_parse_timing_params2(link, DP_TEST_VSYNC_HI, 2,
 458			&link->dp_link.test_video.test_vsync_pol,
 459			&link->dp_link.test_video.test_vsync_width);
 460	if (ret) {
 461		DRM_ERROR("failed to parse (DP_TEST_VSYNC_HI)\n");
 462		return ret;
 463	}
 464
 465	ret = dp_link_parse_timing_params1(link, DP_TEST_H_WIDTH_HI, 2,
 466			&link->dp_link.test_video.test_h_width);
 467	if (ret) {
 468		DRM_ERROR("failed to parse test_h_width(DP_TEST_H_WIDTH_HI)\n");
 469		return ret;
 470	}
 471
 472	ret = dp_link_parse_timing_params1(link, DP_TEST_V_HEIGHT_HI, 2,
 473			&link->dp_link.test_video.test_v_height);
 474	if (ret) {
 475		DRM_ERROR("failed to parse test_v_height\n");
 476		return ret;
 477	}
 478
 479	ret = dp_link_parse_timing_params3(link, DP_TEST_MISC1,
 480		&link->dp_link.test_video.test_rr_d);
 481	link->dp_link.test_video.test_rr_d &= DP_TEST_REFRESH_DENOMINATOR;
 482	if (ret) {
 483		DRM_ERROR("failed to parse test_rr_d (DP_TEST_MISC1)\n");
 484		return ret;
 485	}
 486
 487	ret = dp_link_parse_timing_params3(link, DP_TEST_REFRESH_RATE_NUMERATOR,
 488		&link->dp_link.test_video.test_rr_n);
 489	if (ret) {
 490		DRM_ERROR("failed to parse test_rr_n\n");
 491		return ret;
 492	}
 493
 494	drm_dbg_dp(link->drm_dev,
 495		"link video pattern = 0x%x\n"
 496		"link dynamic range = 0x%x\n"
 497		"link bit depth = 0x%x\n"
 498		"TEST_H_TOTAL = %d, TEST_V_TOTAL = %d\n"
 499		"TEST_H_START = %d, TEST_V_START = %d\n"
 500		"TEST_HSYNC_POL = %d\n"
 501		"TEST_HSYNC_WIDTH = %d\n"
 502		"TEST_VSYNC_POL = %d\n"
 503		"TEST_VSYNC_WIDTH = %d\n"
 504		"TEST_H_WIDTH = %d\n"
 505		"TEST_V_HEIGHT = %d\n"
 506		"TEST_REFRESH_DENOMINATOR = %d\n"
 507		 "TEST_REFRESH_NUMERATOR = %d\n",
 508		link->dp_link.test_video.test_video_pattern,
 509		link->dp_link.test_video.test_dyn_range,
 510		link->dp_link.test_video.test_bit_depth,
 511		link->dp_link.test_video.test_h_total,
 512		link->dp_link.test_video.test_v_total,
 513		link->dp_link.test_video.test_h_start,
 514		link->dp_link.test_video.test_v_start,
 515		link->dp_link.test_video.test_hsync_pol,
 516		link->dp_link.test_video.test_hsync_width,
 517		link->dp_link.test_video.test_vsync_pol,
 518		link->dp_link.test_video.test_vsync_width,
 519		link->dp_link.test_video.test_h_width,
 520		link->dp_link.test_video.test_v_height,
 521		link->dp_link.test_video.test_rr_d,
 522		link->dp_link.test_video.test_rr_n);
 523
 524	return ret;
 525}
 526
 527/**
 528 * dp_link_parse_link_training_params() - parses link training parameters from
 529 * DPCD
 530 * @link: Display Port Driver data
 531 *
 532 * Returns 0 if it successfully parses the link rate (Byte 0x219) and lane
 533 * count (Byte 0x220), and if these values parse are valid.
 534 */
 535static int dp_link_parse_link_training_params(struct dp_link_private *link)
 536{
 537	u8 bp;
 538	ssize_t rlen;
 539
 540	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_LINK_RATE,	&bp);
 541	if (rlen < 0) {
 542		DRM_ERROR("failed to read link rate. rlen=%zd\n", rlen);
 543		return rlen;
 544	}
 545
 546	if (!is_link_rate_valid(bp)) {
 547		DRM_ERROR("invalid link rate = 0x%x\n", bp);
 548		return -EINVAL;
 549	}
 550
 551	link->request.test_link_rate = bp;
 552	drm_dbg_dp(link->drm_dev, "link rate = 0x%x\n",
 553				link->request.test_link_rate);
 554
 555	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_LANE_COUNT, &bp);
 556	if (rlen < 0) {
 557		DRM_ERROR("failed to read lane count. rlen=%zd\n", rlen);
 558		return rlen;
 559	}
 560	bp &= DP_MAX_LANE_COUNT_MASK;
 561
 562	if (!is_lane_count_valid(bp)) {
 563		DRM_ERROR("invalid lane count = 0x%x\n", bp);
 564		return -EINVAL;
 565	}
 566
 567	link->request.test_lane_count = bp;
 568	drm_dbg_dp(link->drm_dev, "lane count = 0x%x\n",
 569				link->request.test_lane_count);
 570	return 0;
 571}
 572
 573/**
 574 * dp_link_parse_phy_test_params() - parses the phy link parameters
 575 * @link: Display Port Driver data
 576 *
 577 * Parses the DPCD (Byte 0x248) for the DP PHY link pattern that is being
 578 * requested.
 579 */
 580static int dp_link_parse_phy_test_params(struct dp_link_private *link)
 581{
 582	u8 data;
 583	ssize_t rlen;
 584
 585	rlen = drm_dp_dpcd_readb(link->aux, DP_PHY_TEST_PATTERN,
 586					&data);
 587	if (rlen < 0) {
 588		DRM_ERROR("failed to read phy link pattern. rlen=%zd\n", rlen);
 589		return rlen;
 590	}
 591
 592	link->dp_link.phy_params.phy_test_pattern_sel = data & 0x07;
 593
 594	drm_dbg_dp(link->drm_dev, "phy_test_pattern_sel = 0x%x\n", data);
 595
 596	switch (data) {
 597	case DP_PHY_TEST_PATTERN_SEL_MASK:
 598	case DP_PHY_TEST_PATTERN_NONE:
 599	case DP_PHY_TEST_PATTERN_D10_2:
 600	case DP_PHY_TEST_PATTERN_ERROR_COUNT:
 601	case DP_PHY_TEST_PATTERN_PRBS7:
 602	case DP_PHY_TEST_PATTERN_80BIT_CUSTOM:
 603	case DP_PHY_TEST_PATTERN_CP2520:
 604		return 0;
 605	default:
 606		return -EINVAL;
 607	}
 608}
 609
 610/**
 611 * dp_link_is_video_audio_test_requested() - checks for audio/video link request
 612 * @link: link requested by the sink
 613 *
 614 * Returns true if the requested link is a permitted audio/video link.
 615 */
 616static bool dp_link_is_video_audio_test_requested(u32 link)
 617{
 618	u8 video_audio_test = (DP_TEST_LINK_VIDEO_PATTERN |
 619				DP_TEST_LINK_AUDIO_PATTERN |
 620				DP_TEST_LINK_AUDIO_DISABLED_VIDEO);
 621
 622	return ((link & video_audio_test) &&
 623		!(link & ~video_audio_test));
 624}
 625
 626/**
 627 * dp_link_parse_request() - parses link request parameters from sink
 628 * @link: Display Port Driver data
 629 *
 630 * Parses the DPCD to check if an automated link is requested (Byte 0x201),
 631 * and what type of link automation is being requested (Byte 0x218).
 632 */
 633static int dp_link_parse_request(struct dp_link_private *link)
 634{
 635	int ret = 0;
 636	u8 data;
 637	ssize_t rlen;
 638
 639	/**
 640	 * Read the device service IRQ vector (Byte 0x201) to determine
 641	 * whether an automated link has been requested by the sink.
 642	 */
 643	rlen = drm_dp_dpcd_readb(link->aux,
 644				DP_DEVICE_SERVICE_IRQ_VECTOR, &data);
 645	if (rlen < 0) {
 646		DRM_ERROR("aux read failed. rlen=%zd\n", rlen);
 647		return rlen;
 648	}
 649
 650	drm_dbg_dp(link->drm_dev, "device service irq vector = 0x%x\n", data);
 651
 652	if (!(data & DP_AUTOMATED_TEST_REQUEST)) {
 653		drm_dbg_dp(link->drm_dev, "no test requested\n");
 654		return 0;
 655	}
 656
 657	/**
 658	 * Read the link request byte (Byte 0x218) to determine what type
 659	 * of automated link has been requested by the sink.
 660	 */
 661	rlen = drm_dp_dpcd_readb(link->aux, DP_TEST_REQUEST, &data);
 662	if (rlen < 0) {
 663		DRM_ERROR("aux read failed. rlen=%zd\n", rlen);
 664		return rlen;
 665	}
 666
 667	if (!data || (data == DP_TEST_LINK_FAUX_PATTERN)) {
 668		drm_dbg_dp(link->drm_dev, "link 0x%x not supported\n", data);
 669		goto end;
 670	}
 671
 672	drm_dbg_dp(link->drm_dev, "Test:(0x%x) requested\n", data);
 673	link->request.test_requested = data;
 674	if (link->request.test_requested == DP_TEST_LINK_PHY_TEST_PATTERN) {
 675		ret = dp_link_parse_phy_test_params(link);
 676		if (ret)
 677			goto end;
 678		ret = dp_link_parse_link_training_params(link);
 679		if (ret)
 680			goto end;
 681	}
 682
 683	if (link->request.test_requested == DP_TEST_LINK_TRAINING) {
 684		ret = dp_link_parse_link_training_params(link);
 685		if (ret)
 686			goto end;
 687	}
 688
 689	if (dp_link_is_video_audio_test_requested(
 690			link->request.test_requested)) {
 691		ret = dp_link_parse_video_pattern_params(link);
 692		if (ret)
 693			goto end;
 694
 695		ret = dp_link_parse_audio_pattern_params(link);
 696	}
 697end:
 698	/*
 699	 * Send a DP_TEST_ACK if all link parameters are valid, otherwise send
 700	 * a DP_TEST_NAK.
 701	 */
 702	if (ret) {
 703		link->dp_link.test_response = DP_TEST_NAK;
 704	} else {
 705		if (link->request.test_requested != DP_TEST_LINK_EDID_READ)
 706			link->dp_link.test_response = DP_TEST_ACK;
 707		else
 708			link->dp_link.test_response =
 709				DP_TEST_EDID_CHECKSUM_WRITE;
 710	}
 711
 712	return ret;
 713}
 714
 715/**
 716 * dp_link_parse_sink_count() - parses the sink count
 717 * @dp_link: pointer to link module data
 718 *
 719 * Parses the DPCD to check if there is an update to the sink count
 720 * (Byte 0x200), and whether all the sink devices connected have Content
 721 * Protection enabled.
 722 */
 723static int dp_link_parse_sink_count(struct dp_link *dp_link)
 724{
 725	ssize_t rlen;
 726	bool cp_ready;
 727
 728	struct dp_link_private *link = container_of(dp_link,
 729			struct dp_link_private, dp_link);
 730
 731	rlen = drm_dp_dpcd_readb(link->aux, DP_SINK_COUNT,
 732				 &link->dp_link.sink_count);
 733	if (rlen < 0) {
 734		DRM_ERROR("sink count read failed. rlen=%zd\n", rlen);
 735		return rlen;
 736	}
 737
 738	cp_ready = link->dp_link.sink_count & DP_SINK_CP_READY;
 739
 740	link->dp_link.sink_count =
 741		DP_GET_SINK_COUNT(link->dp_link.sink_count);
 742
 743	drm_dbg_dp(link->drm_dev, "sink_count = 0x%x, cp_ready = 0x%x\n",
 744				link->dp_link.sink_count, cp_ready);
 745	return 0;
 746}
 747
 748static int dp_link_parse_sink_status_field(struct dp_link_private *link)
 749{
 750	int len = 0;
 751
 752	link->prev_sink_count = link->dp_link.sink_count;
 753	len = dp_link_parse_sink_count(&link->dp_link);
 754	if (len < 0) {
 755		DRM_ERROR("DP parse sink count failed\n");
 756		return len;
 757	}
 758
 759	len = drm_dp_dpcd_read_link_status(link->aux,
 760		link->link_status);
 761	if (len < DP_LINK_STATUS_SIZE) {
 762		DRM_ERROR("DP link status read failed\n");
 763		return len;
 764	}
 765
 766	return dp_link_parse_request(link);
 767}
 768
 769/**
 770 * dp_link_process_link_training_request() - processes new training requests
 771 * @link: Display Port link data
 772 *
 773 * This function will handle new link training requests that are initiated by
 774 * the sink. In particular, it will update the requested lane count and link
 775 * rate, and then trigger the link retraining procedure.
 776 *
 777 * The function will return 0 if a link training request has been processed,
 778 * otherwise it will return -EINVAL.
 779 */
 780static int dp_link_process_link_training_request(struct dp_link_private *link)
 781{
 782	if (link->request.test_requested != DP_TEST_LINK_TRAINING)
 783		return -EINVAL;
 784
 785	drm_dbg_dp(link->drm_dev,
 786			"Test:0x%x link rate = 0x%x, lane count = 0x%x\n",
 787			DP_TEST_LINK_TRAINING,
 788			link->request.test_link_rate,
 789			link->request.test_lane_count);
 790
 791	link->dp_link.link_params.num_lanes = link->request.test_lane_count;
 792	link->dp_link.link_params.rate =
 793		drm_dp_bw_code_to_link_rate(link->request.test_link_rate);
 794
 795	return 0;
 796}
 797
 798bool dp_link_send_test_response(struct dp_link *dp_link)
 799{
 800	struct dp_link_private *link = NULL;
 801	int ret = 0;
 802
 803	if (!dp_link) {
 804		DRM_ERROR("invalid input\n");
 805		return false;
 806	}
 807
 808	link = container_of(dp_link, struct dp_link_private, dp_link);
 809
 810	ret = drm_dp_dpcd_writeb(link->aux, DP_TEST_RESPONSE,
 811			dp_link->test_response);
 812
 813	return ret == 1;
 814}
 815
 816int dp_link_psm_config(struct dp_link *dp_link,
 817			      struct dp_link_info *link_info, bool enable)
 818{
 819	struct dp_link_private *link = NULL;
 820	int ret = 0;
 821
 822	if (!dp_link) {
 823		DRM_ERROR("invalid params\n");
 824		return -EINVAL;
 825	}
 826
 827	link = container_of(dp_link, struct dp_link_private, dp_link);
 828
 829	mutex_lock(&link->psm_mutex);
 830	if (enable)
 831		ret = dp_aux_link_power_down(link->aux, link_info);
 832	else
 833		ret = dp_aux_link_power_up(link->aux, link_info);
 834
 835	if (ret)
 836		DRM_ERROR("Failed to %s low power mode\n", enable ?
 837							"enter" : "exit");
 838	else
 839		dp_link->psm_enabled = enable;
 840
 841	mutex_unlock(&link->psm_mutex);
 842	return ret;
 843}
 844
 845bool dp_link_send_edid_checksum(struct dp_link *dp_link, u8 checksum)
 846{
 847	struct dp_link_private *link = NULL;
 848	int ret = 0;
 849
 850	if (!dp_link) {
 851		DRM_ERROR("invalid input\n");
 852		return false;
 853	}
 854
 855	link = container_of(dp_link, struct dp_link_private, dp_link);
 856
 857	ret = drm_dp_dpcd_writeb(link->aux, DP_TEST_EDID_CHECKSUM,
 858						checksum);
 859	return ret == 1;
 860}
 861
 862static void dp_link_parse_vx_px(struct dp_link_private *link)
 863{
 864	drm_dbg_dp(link->drm_dev, "vx: 0=%d, 1=%d, 2=%d, 3=%d\n",
 865		drm_dp_get_adjust_request_voltage(link->link_status, 0),
 866		drm_dp_get_adjust_request_voltage(link->link_status, 1),
 867		drm_dp_get_adjust_request_voltage(link->link_status, 2),
 868		drm_dp_get_adjust_request_voltage(link->link_status, 3));
 869
 870	drm_dbg_dp(link->drm_dev, "px: 0=%d, 1=%d, 2=%d, 3=%d\n",
 871		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 0),
 872		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 1),
 873		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 2),
 874		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 3));
 875
 876	/**
 877	 * Update the voltage and pre-emphasis levels as per DPCD request
 878	 * vector.
 879	 */
 880	drm_dbg_dp(link->drm_dev,
 881			 "Current: v_level = 0x%x, p_level = 0x%x\n",
 882			link->dp_link.phy_params.v_level,
 883			link->dp_link.phy_params.p_level);
 884	link->dp_link.phy_params.v_level =
 885		drm_dp_get_adjust_request_voltage(link->link_status, 0);
 886	link->dp_link.phy_params.p_level =
 887		drm_dp_get_adjust_request_pre_emphasis(link->link_status, 0);
 888
 889	link->dp_link.phy_params.p_level >>= DP_TRAIN_PRE_EMPHASIS_SHIFT;
 890
 891	drm_dbg_dp(link->drm_dev,
 892			"Requested: v_level = 0x%x, p_level = 0x%x\n",
 893			link->dp_link.phy_params.v_level,
 894			link->dp_link.phy_params.p_level);
 895}
 896
 897/**
 898 * dp_link_process_phy_test_pattern_request() - process new phy link requests
 899 * @link: Display Port Driver data
 900 *
 901 * This function will handle new phy link pattern requests that are initiated
 902 * by the sink. The function will return 0 if a phy link pattern has been
 903 * processed, otherwise it will return -EINVAL.
 904 */
 905static int dp_link_process_phy_test_pattern_request(
 906		struct dp_link_private *link)
 907{
 908	if (!(link->request.test_requested & DP_TEST_LINK_PHY_TEST_PATTERN)) {
 909		drm_dbg_dp(link->drm_dev, "no phy test\n");
 910		return -EINVAL;
 911	}
 912
 913	if (!is_link_rate_valid(link->request.test_link_rate) ||
 914		!is_lane_count_valid(link->request.test_lane_count)) {
 915		DRM_ERROR("Invalid: link rate = 0x%x,lane count = 0x%x\n",
 916				link->request.test_link_rate,
 917				link->request.test_lane_count);
 918		return -EINVAL;
 919	}
 920
 921	drm_dbg_dp(link->drm_dev,
 922			"Current: rate = 0x%x, lane count = 0x%x\n",
 923			link->dp_link.link_params.rate,
 924			link->dp_link.link_params.num_lanes);
 925
 926	drm_dbg_dp(link->drm_dev,
 927			"Requested: rate = 0x%x, lane count = 0x%x\n",
 928			link->request.test_link_rate,
 929			link->request.test_lane_count);
 930
 931	link->dp_link.link_params.num_lanes = link->request.test_lane_count;
 932	link->dp_link.link_params.rate =
 933		drm_dp_bw_code_to_link_rate(link->request.test_link_rate);
 934
 935	dp_link_parse_vx_px(link);
 936
 937	return 0;
 938}
 939
 940static u8 get_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
 941{
 942	return link_status[r - DP_LANE0_1_STATUS];
 943}
 944
 945/**
 946 * dp_link_process_link_status_update() - processes link status updates
 947 * @link: Display Port link module data
 948 *
 949 * This function will check for changes in the link status, e.g. clock
 950 * recovery done on all lanes, and trigger link training if there is a
 951 * failure/error on the link.
 952 *
 953 * The function will return 0 if the a link status update has been processed,
 954 * otherwise it will return -EINVAL.
 955 */
 956static int dp_link_process_link_status_update(struct dp_link_private *link)
 957{
 958	bool channel_eq_done = drm_dp_channel_eq_ok(link->link_status,
 959			link->dp_link.link_params.num_lanes);
 960
 961	bool clock_recovery_done = drm_dp_clock_recovery_ok(link->link_status,
 962			link->dp_link.link_params.num_lanes);
 963
 964	drm_dbg_dp(link->drm_dev,
 965		       "channel_eq_done = %d, clock_recovery_done = %d\n",
 966                        channel_eq_done, clock_recovery_done);
 967
 968	if (channel_eq_done && clock_recovery_done)
 969		return -EINVAL;
 970
 971	return 0;
 972}
 973
 974/**
 975 * dp_link_process_ds_port_status_change() - process port status changes
 976 * @link: Display Port Driver data
 977 *
 978 * This function will handle downstream port updates that are initiated by
 979 * the sink. If the downstream port status has changed, the EDID is read via
 980 * AUX.
 981 *
 982 * The function will return 0 if a downstream port update has been
 983 * processed, otherwise it will return -EINVAL.
 984 */
 985static int dp_link_process_ds_port_status_change(struct dp_link_private *link)
 986{
 987	if (get_link_status(link->link_status, DP_LANE_ALIGN_STATUS_UPDATED) &
 988					DP_DOWNSTREAM_PORT_STATUS_CHANGED)
 989		goto reset;
 990
 991	if (link->prev_sink_count == link->dp_link.sink_count)
 992		return -EINVAL;
 993
 994reset:
 995	/* reset prev_sink_count */
 996	link->prev_sink_count = link->dp_link.sink_count;
 997
 998	return 0;
 999}
1000
1001static bool dp_link_is_video_pattern_requested(struct dp_link_private *link)
1002{
1003	return (link->request.test_requested & DP_TEST_LINK_VIDEO_PATTERN)
1004		&& !(link->request.test_requested &
1005		DP_TEST_LINK_AUDIO_DISABLED_VIDEO);
1006}
1007
1008static bool dp_link_is_audio_pattern_requested(struct dp_link_private *link)
1009{
1010	return (link->request.test_requested & DP_TEST_LINK_AUDIO_PATTERN);
1011}
1012
1013static void dp_link_reset_data(struct dp_link_private *link)
1014{
1015	link->request = (const struct dp_link_request){ 0 };
1016	link->dp_link.test_video = (const struct dp_link_test_video){ 0 };
1017	link->dp_link.test_video.test_bit_depth = DP_TEST_BIT_DEPTH_UNKNOWN;
1018	link->dp_link.test_audio = (const struct dp_link_test_audio){ 0 };
1019	link->dp_link.phy_params.phy_test_pattern_sel = 0;
1020	link->dp_link.sink_request = 0;
1021	link->dp_link.test_response = 0;
1022}
1023
1024/**
1025 * dp_link_process_request() - handle HPD IRQ transition to HIGH
1026 * @dp_link: pointer to link module data
1027 *
1028 * This function will handle the HPD IRQ state transitions from LOW to HIGH
1029 * (including cases when there are back to back HPD IRQ HIGH) indicating
1030 * the start of a new link training request or sink status update.
1031 */
1032int dp_link_process_request(struct dp_link *dp_link)
1033{
1034	int ret = 0;
1035	struct dp_link_private *link;
1036
1037	if (!dp_link) {
1038		DRM_ERROR("invalid input\n");
1039		return -EINVAL;
1040	}
1041
1042	link = container_of(dp_link, struct dp_link_private, dp_link);
1043
1044	dp_link_reset_data(link);
1045
1046	ret = dp_link_parse_sink_status_field(link);
1047	if (ret)
1048		return ret;
1049
1050	if (link->request.test_requested == DP_TEST_LINK_EDID_READ) {
1051		dp_link->sink_request |= DP_TEST_LINK_EDID_READ;
1052	} else if (!dp_link_process_ds_port_status_change(link)) {
1053		dp_link->sink_request |= DS_PORT_STATUS_CHANGED;
1054	} else if (!dp_link_process_link_training_request(link)) {
1055		dp_link->sink_request |= DP_TEST_LINK_TRAINING;
1056	} else if (!dp_link_process_phy_test_pattern_request(link)) {
1057		dp_link->sink_request |= DP_TEST_LINK_PHY_TEST_PATTERN;
1058	} else {
1059		ret = dp_link_process_link_status_update(link);
1060		if (!ret) {
1061			dp_link->sink_request |= DP_LINK_STATUS_UPDATED;
1062		} else {
1063			if (dp_link_is_video_pattern_requested(link)) {
1064				ret = 0;
1065				dp_link->sink_request |= DP_TEST_LINK_VIDEO_PATTERN;
1066			}
1067			if (dp_link_is_audio_pattern_requested(link)) {
1068				dp_link->sink_request |= DP_TEST_LINK_AUDIO_PATTERN;
1069				ret = -EINVAL;
1070			}
1071		}
1072	}
1073
1074	drm_dbg_dp(link->drm_dev, "sink request=%#x",
1075				dp_link->sink_request);
1076	return ret;
1077}
1078
1079int dp_link_get_colorimetry_config(struct dp_link *dp_link)
1080{
1081	u32 cc;
1082	struct dp_link_private *link;
1083
1084	if (!dp_link) {
1085		DRM_ERROR("invalid input\n");
1086		return -EINVAL;
1087	}
1088
1089	link = container_of(dp_link, struct dp_link_private, dp_link);
1090
1091	/*
1092	 * Unless a video pattern CTS test is ongoing, use RGB_VESA
1093	 * Only RGB_VESA and RGB_CEA supported for now
1094	 */
1095	if (dp_link_is_video_pattern_requested(link))
1096		cc = link->dp_link.test_video.test_dyn_range;
1097	else
1098		cc = DP_TEST_DYNAMIC_RANGE_VESA;
1099
1100	return cc;
1101}
1102
1103int dp_link_adjust_levels(struct dp_link *dp_link, u8 *link_status)
1104{
1105	int i;
1106	int v_max = 0, p_max = 0;
1107	struct dp_link_private *link;
1108
1109	if (!dp_link) {
1110		DRM_ERROR("invalid input\n");
1111		return -EINVAL;
1112	}
1113
1114	link = container_of(dp_link, struct dp_link_private, dp_link);
1115
1116	/* use the max level across lanes */
1117	for (i = 0; i < dp_link->link_params.num_lanes; i++) {
1118		u8 data_v = drm_dp_get_adjust_request_voltage(link_status, i);
1119		u8 data_p = drm_dp_get_adjust_request_pre_emphasis(link_status,
1120									 i);
1121		drm_dbg_dp(link->drm_dev,
1122				"lane=%d req_vol_swing=%d req_pre_emphasis=%d\n",
1123				i, data_v, data_p);
1124		if (v_max < data_v)
1125			v_max = data_v;
1126		if (p_max < data_p)
1127			p_max = data_p;
1128	}
1129
1130	dp_link->phy_params.v_level = v_max >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
1131	dp_link->phy_params.p_level = p_max >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
1132
1133	/**
1134	 * Adjust the voltage swing and pre-emphasis level combination to within
1135	 * the allowable range.
1136	 */
1137	if (dp_link->phy_params.v_level > DP_TRAIN_VOLTAGE_SWING_MAX) {
1138		drm_dbg_dp(link->drm_dev,
1139			"Requested vSwingLevel=%d, change to %d\n",
1140			dp_link->phy_params.v_level,
1141			DP_TRAIN_VOLTAGE_SWING_MAX);
1142		dp_link->phy_params.v_level = DP_TRAIN_VOLTAGE_SWING_MAX;
1143	}
1144
1145	if (dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_MAX) {
1146		drm_dbg_dp(link->drm_dev,
1147			"Requested preEmphasisLevel=%d, change to %d\n",
1148			dp_link->phy_params.p_level,
1149			DP_TRAIN_PRE_EMPHASIS_MAX);
1150		dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_MAX;
1151	}
1152
1153	if ((dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_LVL_1)
1154		&& (dp_link->phy_params.v_level ==
1155			DP_TRAIN_VOLTAGE_SWING_LVL_2)) {
1156		drm_dbg_dp(link->drm_dev,
1157			"Requested preEmphasisLevel=%d, change to %d\n",
1158			dp_link->phy_params.p_level,
1159			DP_TRAIN_PRE_EMPHASIS_LVL_1);
1160		dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_LVL_1;
1161	}
1162
1163	drm_dbg_dp(link->drm_dev, "adjusted: v_level=%d, p_level=%d\n",
1164		dp_link->phy_params.v_level, dp_link->phy_params.p_level);
1165
1166	return 0;
1167}
1168
1169void dp_link_reset_phy_params_vx_px(struct dp_link *dp_link)
1170{
1171	dp_link->phy_params.v_level = 0;
1172	dp_link->phy_params.p_level = 0;
1173}
1174
1175u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp)
1176{
1177	u32 tbd;
1178
1179	/*
1180	 * Few simplistic rules and assumptions made here:
1181	 *    1. Test bit depth is bit depth per color component
1182	 *    2. Assume 3 color components
1183	 */
1184	switch (bpp) {
1185	case 18:
1186		tbd = DP_TEST_BIT_DEPTH_6;
1187		break;
1188	case 24:
1189		tbd = DP_TEST_BIT_DEPTH_8;
1190		break;
1191	case 30:
1192		tbd = DP_TEST_BIT_DEPTH_10;
1193		break;
1194	default:
1195		tbd = DP_TEST_BIT_DEPTH_UNKNOWN;
1196		break;
1197	}
1198
1199	if (tbd != DP_TEST_BIT_DEPTH_UNKNOWN)
1200		tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT);
1201
1202	return tbd;
1203}
1204
1205struct dp_link *dp_link_get(struct device *dev, struct drm_dp_aux *aux)
1206{
1207	struct dp_link_private *link;
1208	struct dp_link *dp_link;
1209
1210	if (!dev || !aux) {
1211		DRM_ERROR("invalid input\n");
1212		return ERR_PTR(-EINVAL);
1213	}
1214
1215	link = devm_kzalloc(dev, sizeof(*link), GFP_KERNEL);
1216	if (!link)
1217		return ERR_PTR(-ENOMEM);
1218
1219	link->dev   = dev;
1220	link->aux   = aux;
1221
1222	mutex_init(&link->psm_mutex);
1223	dp_link = &link->dp_link;
1224
1225	return dp_link;
1226}