Free Electrons

Embedded Linux Experts

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
/*
 * Copyright (c) 2006-2008 Intel Corporation
 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
 *
 * DRM core CRTC related functions
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 *
 * Authors:
 *      Keith Packard
 *	Eric Anholt <eric@anholt.net>
 *      Dave Airlie <airlied@linux.ie>
 *      Jesse Barnes <jesse.barnes@intel.com>
 */

#include <linux/export.h>
#include <linux/moduleparam.h>

#include "drmP.h"
#include "drm_crtc.h"
#include "drm_fourcc.h"
#include "drm_crtc_helper.h"
#include "drm_fb_helper.h"
#include "drm_edid.h"

static bool drm_kms_helper_poll = true;
module_param_named(poll, drm_kms_helper_poll, bool, 0600);

static void drm_mode_validate_flag(struct drm_connector *connector,
				   int flags)
{
	struct drm_display_mode *mode;

	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE))
		return;

	list_for_each_entry(mode, &connector->modes, head) {
		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
				!(flags & DRM_MODE_FLAG_INTERLACE))
			mode->status = MODE_NO_INTERLACE;
		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
				!(flags & DRM_MODE_FLAG_DBLSCAN))
			mode->status = MODE_NO_DBLESCAN;
	}

	return;
}

/**
 * drm_helper_probe_single_connector_modes - get complete set of display modes
 * @dev: DRM device
 * @maxX: max width for modes
 * @maxY: max height for modes
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Based on @dev's mode_config layout, scan all the connectors and try to detect
 * modes on them.  Modes will first be added to the connector's probed_modes
 * list, then culled (based on validity and the @maxX, @maxY parameters) and
 * put into the normal modes list.
 *
 * Intended to be used either at bootup time or when major configuration
 * changes have occurred.
 *
 * FIXME: take into account monitor limits
 *
 * RETURNS:
 * Number of modes found on @connector.
 */
int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
					    uint32_t maxX, uint32_t maxY)
{
	struct drm_device *dev = connector->dev;
	struct drm_display_mode *mode;
	struct drm_connector_helper_funcs *connector_funcs =
		connector->helper_private;
	int count = 0;
	int mode_flags = 0;

	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
			drm_get_connector_name(connector));
	/* set all modes to the unverified state */
	list_for_each_entry(mode, &connector->modes, head)
		mode->status = MODE_UNVERIFIED;

	if (connector->force) {
		if (connector->force == DRM_FORCE_ON)
			connector->status = connector_status_connected;
		else
			connector->status = connector_status_disconnected;
		if (connector->funcs->force)
			connector->funcs->force(connector);
	} else {
		connector->status = connector->funcs->detect(connector, true);
		drm_kms_helper_poll_enable(dev);
	}

	if (connector->status == connector_status_disconnected) {
		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
			connector->base.id, drm_get_connector_name(connector));
		drm_mode_connector_update_edid_property(connector, NULL);
		goto prune;
	}

#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
	count = drm_load_edid_firmware(connector);
	if (count == 0)
#endif
		count = (*connector_funcs->get_modes)(connector);

	if (count == 0 && connector->status == connector_status_connected)
		count = drm_add_modes_noedid(connector, 1024, 768);
	if (count == 0)
		goto prune;

	drm_mode_connector_list_update(connector);

	if (maxX && maxY)
		drm_mode_validate_size(dev, &connector->modes, maxX,
				       maxY, 0);

	if (connector->interlace_allowed)
		mode_flags |= DRM_MODE_FLAG_INTERLACE;
	if (connector->doublescan_allowed)
		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
	drm_mode_validate_flag(connector, mode_flags);

	list_for_each_entry(mode, &connector->modes, head) {
		if (mode->status == MODE_OK)
			mode->status = connector_funcs->mode_valid(connector,
								   mode);
	}

prune:
	drm_mode_prune_invalid(dev, &connector->modes, true);

	if (list_empty(&connector->modes))
		return 0;

	drm_mode_sort(&connector->modes);

	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
			drm_get_connector_name(connector));
	list_for_each_entry(mode, &connector->modes, head) {
		mode->vrefresh = drm_mode_vrefresh(mode);

		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
		drm_mode_debug_printmodeline(mode);
	}

	return count;
}
EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);

/**
 * drm_helper_encoder_in_use - check if a given encoder is in use
 * @encoder: encoder to check
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Walk @encoders's DRM device's mode_config and see if it's in use.
 *
 * RETURNS:
 * True if @encoder is part of the mode_config, false otherwise.
 */
bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
{
	struct drm_connector *connector;
	struct drm_device *dev = encoder->dev;
	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
		if (connector->encoder == encoder)
			return true;
	return false;
}
EXPORT_SYMBOL(drm_helper_encoder_in_use);

/**
 * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 * @crtc: CRTC to check
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Walk @crtc's DRM device's mode_config and see if it's in use.
 *
 * RETURNS:
 * True if @crtc is part of the mode_config, false otherwise.
 */
bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
{
	struct drm_encoder *encoder;
	struct drm_device *dev = crtc->dev;
	/* FIXME: Locking around list access? */
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
		if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
			return true;
	return false;
}
EXPORT_SYMBOL(drm_helper_crtc_in_use);

static void
drm_encoder_disable(struct drm_encoder *encoder)
{
	struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;

	if (encoder_funcs->disable)
		(*encoder_funcs->disable)(encoder);
	else
		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
}

/**
 * drm_helper_disable_unused_functions - disable unused objects
 * @dev: DRM device
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * If an connector or CRTC isn't part of @dev's mode_config, it can be disabled
 * by calling its dpms function, which should power it off.
 */
void drm_helper_disable_unused_functions(struct drm_device *dev)
{
	struct drm_encoder *encoder;
	struct drm_connector *connector;
	struct drm_crtc *crtc;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		if (!connector->encoder)
			continue;
		if (connector->status == connector_status_disconnected)
			connector->encoder = NULL;
	}

	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
		if (!drm_helper_encoder_in_use(encoder)) {
			drm_encoder_disable(encoder);
			/* disconnector encoder from any connector */
			encoder->crtc = NULL;
		}
	}

	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
		struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
		crtc->enabled = drm_helper_crtc_in_use(crtc);
		if (!crtc->enabled) {
			if (crtc_funcs->disable)
				(*crtc_funcs->disable)(crtc);
			else
				(*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
			crtc->fb = NULL;
		}
	}
}
EXPORT_SYMBOL(drm_helper_disable_unused_functions);

/**
 * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
 * @encoder: encoder to test
 * @crtc: crtc to test
 *
 * Return false if @encoder can't be driven by @crtc, true otherwise.
 */
static bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
				struct drm_crtc *crtc)
{
	struct drm_device *dev;
	struct drm_crtc *tmp;
	int crtc_mask = 1;

	WARN(!crtc, "checking null crtc?\n");

	dev = crtc->dev;

	list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
		if (tmp == crtc)
			break;
		crtc_mask <<= 1;
	}

	if (encoder->possible_crtcs & crtc_mask)
		return true;
	return false;
}

/*
 * Check the CRTC we're going to map each output to vs. its current
 * CRTC.  If they don't match, we have to disable the output and the CRTC
 * since the driver will have to re-route things.
 */
static void
drm_crtc_prepare_encoders(struct drm_device *dev)
{
	struct drm_encoder_helper_funcs *encoder_funcs;
	struct drm_encoder *encoder;

	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
		encoder_funcs = encoder->helper_private;
		/* Disable unused encoders */
		if (encoder->crtc == NULL)
			drm_encoder_disable(encoder);
		/* Disable encoders whose CRTC is about to change */
		if (encoder_funcs->get_crtc &&
		    encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
			drm_encoder_disable(encoder);
	}
}

/**
 * drm_crtc_set_mode - set a mode
 * @crtc: CRTC to program
 * @mode: mode to use
 * @x: width of mode
 * @y: height of mode
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 * to fixup or reject the mode prior to trying to set it.
 *
 * RETURNS:
 * True if the mode was set successfully, or false otherwise.
 */
bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
			      struct drm_display_mode *mode,
			      int x, int y,
			      struct drm_framebuffer *old_fb)
{
	struct drm_device *dev = crtc->dev;
	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
	struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
	struct drm_encoder_helper_funcs *encoder_funcs;
	int saved_x, saved_y;
	struct drm_encoder *encoder;
	bool ret = true;

	crtc->enabled = drm_helper_crtc_in_use(crtc);
	if (!crtc->enabled)
		return true;

	adjusted_mode = drm_mode_duplicate(dev, mode);
	if (!adjusted_mode)
		return false;

	saved_hwmode = crtc->hwmode;
	saved_mode = crtc->mode;
	saved_x = crtc->x;
	saved_y = crtc->y;

	/* Update crtc values up front so the driver can rely on them for mode
	 * setting.
	 */
	crtc->mode = *mode;
	crtc->x = x;
	crtc->y = y;

	/* Pass our mode to the connectors and the CRTC to give them a chance to
	 * adjust it according to limitations or connector properties, and also
	 * a chance to reject the mode entirely.
	 */
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

		if (encoder->crtc != crtc)
			continue;
		encoder_funcs = encoder->helper_private;
		if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
						      adjusted_mode))) {
			DRM_DEBUG_KMS("Encoder fixup failed\n");
			goto done;
		}
	}

	if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
		DRM_DEBUG_KMS("CRTC fixup failed\n");
		goto done;
	}
	DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);

	/* Prepare the encoders and CRTCs before setting the mode. */
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

		if (encoder->crtc != crtc)
			continue;
		encoder_funcs = encoder->helper_private;
		/* Disable the encoders as the first thing we do. */
		encoder_funcs->prepare(encoder);
	}

	drm_crtc_prepare_encoders(dev);

	crtc_funcs->prepare(crtc);

	/* Set up the DPLL and any encoders state that needs to adjust or depend
	 * on the DPLL.
	 */
	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
	if (!ret)
	    goto done;

	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

		if (encoder->crtc != crtc)
			continue;

		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
			encoder->base.id, drm_get_encoder_name(encoder),
			mode->base.id, mode->name);
		encoder_funcs = encoder->helper_private;
		encoder_funcs->mode_set(encoder, mode, adjusted_mode);
	}

	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
	crtc_funcs->commit(crtc);

	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

		if (encoder->crtc != crtc)
			continue;

		encoder_funcs = encoder->helper_private;
		encoder_funcs->commit(encoder);

	}

	/* Store real post-adjustment hardware mode. */
	crtc->hwmode = *adjusted_mode;

	/* Calculate and store various constants which
	 * are later needed by vblank and swap-completion
	 * timestamping. They are derived from true hwmode.
	 */
	drm_calc_timestamping_constants(crtc);

	/* FIXME: add subpixel order */
done:
	drm_mode_destroy(dev, adjusted_mode);
	if (!ret) {
		crtc->hwmode = saved_hwmode;
		crtc->mode = saved_mode;
		crtc->x = saved_x;
		crtc->y = saved_y;
	}

	return ret;
}
EXPORT_SYMBOL(drm_crtc_helper_set_mode);


static int
drm_crtc_helper_disable(struct drm_crtc *crtc)
{
	struct drm_device *dev = crtc->dev;
	struct drm_connector *connector;
	struct drm_encoder *encoder;

	/* Decouple all encoders and their attached connectors from this crtc */
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
		if (encoder->crtc != crtc)
			continue;

		list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
			if (connector->encoder != encoder)
				continue;

			connector->encoder = NULL;
		}
	}

	drm_helper_disable_unused_functions(dev);
	return 0;
}

/**
 * drm_crtc_helper_set_config - set a new config from userspace
 * @crtc: CRTC to setup
 * @crtc_info: user provided configuration
 * @new_mode: new mode to set
 * @connector_set: set of connectors for the new config
 * @fb: new framebuffer
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Setup a new configuration, provided by the user in @crtc_info, and enable
 * it.
 *
 * RETURNS:
 * Zero. (FIXME)
 */
int drm_crtc_helper_set_config(struct drm_mode_set *set)
{
	struct drm_device *dev;
	struct drm_crtc *save_crtcs, *new_crtc, *crtc;
	struct drm_encoder *save_encoders, *new_encoder, *encoder;
	struct drm_framebuffer *old_fb = NULL;
	bool mode_changed = false; /* if true do a full mode set */
	bool fb_changed = false; /* if true and !mode_changed just do a flip */
	struct drm_connector *save_connectors, *connector;
	int count = 0, ro, fail = 0;
	struct drm_crtc_helper_funcs *crtc_funcs;
	struct drm_mode_set save_set;
	int ret = 0;
	int i;

	DRM_DEBUG_KMS("\n");

	if (!set)
		return -EINVAL;

	if (!set->crtc)
		return -EINVAL;

	if (!set->crtc->helper_private)
		return -EINVAL;

	crtc_funcs = set->crtc->helper_private;

	if (!set->mode)
		set->fb = NULL;

	if (set->fb) {
		DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
				set->crtc->base.id, set->fb->base.id,
				(int)set->num_connectors, set->x, set->y);
	} else {
		DRM_DEBUG_KMS("[CRTC:%d] [NOFB]\n", set->crtc->base.id);
		return drm_crtc_helper_disable(set->crtc);
	}

	dev = set->crtc->dev;

	/* Allocate space for the backup of all (non-pointer) crtc, encoder and
	 * connector data. */
	save_crtcs = kzalloc(dev->mode_config.num_crtc *
			     sizeof(struct drm_crtc), GFP_KERNEL);
	if (!save_crtcs)
		return -ENOMEM;

	save_encoders = kzalloc(dev->mode_config.num_encoder *
				sizeof(struct drm_encoder), GFP_KERNEL);
	if (!save_encoders) {
		kfree(save_crtcs);
		return -ENOMEM;
	}

	save_connectors = kzalloc(dev->mode_config.num_connector *
				sizeof(struct drm_connector), GFP_KERNEL);
	if (!save_connectors) {
		kfree(save_crtcs);
		kfree(save_encoders);
		return -ENOMEM;
	}

	/* Copy data. Note that driver private data is not affected.
	 * Should anything bad happen only the expected state is
	 * restored, not the drivers personal bookkeeping.
	 */
	count = 0;
	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
		save_crtcs[count++] = *crtc;
	}

	count = 0;
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
		save_encoders[count++] = *encoder;
	}

	count = 0;
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		save_connectors[count++] = *connector;
	}

	save_set.crtc = set->crtc;
	save_set.mode = &set->crtc->mode;
	save_set.x = set->crtc->x;
	save_set.y = set->crtc->y;
	save_set.fb = set->crtc->fb;

	/* We should be able to check here if the fb has the same properties
	 * and then just flip_or_move it */
	if (set->crtc->fb != set->fb) {
		/* If we have no fb then treat it as a full mode set */
		if (set->crtc->fb == NULL) {
			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
			mode_changed = true;
		} else if (set->fb == NULL) {
			mode_changed = true;
		} else if (set->fb->depth != set->crtc->fb->depth) {
			mode_changed = true;
		} else if (set->fb->bits_per_pixel !=
			   set->crtc->fb->bits_per_pixel) {
			mode_changed = true;
		} else
			fb_changed = true;
	}

	if (set->x != set->crtc->x || set->y != set->crtc->y)
		fb_changed = true;

	if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
		DRM_DEBUG_KMS("modes are different, full mode set\n");
		drm_mode_debug_printmodeline(&set->crtc->mode);
		drm_mode_debug_printmodeline(set->mode);
		mode_changed = true;
	}

	/* a) traverse passed in connector list and get encoders for them */
	count = 0;
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		struct drm_connector_helper_funcs *connector_funcs =
			connector->helper_private;
		new_encoder = connector->encoder;
		for (ro = 0; ro < set->num_connectors; ro++) {
			if (set->connectors[ro] == connector) {
				new_encoder = connector_funcs->best_encoder(connector);
				/* if we can't get an encoder for a connector
				   we are setting now - then fail */
				if (new_encoder == NULL)
					/* don't break so fail path works correct */
					fail = 1;
				break;
			}
		}

		if (new_encoder != connector->encoder) {
			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
			mode_changed = true;
			/* If the encoder is reused for another connector, then
			 * the appropriate crtc will be set later.
			 */
			if (connector->encoder)
				connector->encoder->crtc = NULL;
			connector->encoder = new_encoder;
		}
	}

	if (fail) {
		ret = -EINVAL;
		goto fail;
	}

	count = 0;
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		if (!connector->encoder)
			continue;

		if (connector->encoder->crtc == set->crtc)
			new_crtc = NULL;
		else
			new_crtc = connector->encoder->crtc;

		for (ro = 0; ro < set->num_connectors; ro++) {
			if (set->connectors[ro] == connector)
				new_crtc = set->crtc;
		}

		/* Make sure the new CRTC will work with the encoder */
		if (new_crtc &&
		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
			ret = -EINVAL;
			goto fail;
		}
		if (new_crtc != connector->encoder->crtc) {
			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
			mode_changed = true;
			connector->encoder->crtc = new_crtc;
		}
		if (new_crtc) {
			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
				connector->base.id, drm_get_connector_name(connector),
				new_crtc->base.id);
		} else {
			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
				connector->base.id, drm_get_connector_name(connector));
		}
	}

	/* mode_set_base is not a required function */
	if (fb_changed && !crtc_funcs->mode_set_base)
		mode_changed = true;

	if (mode_changed) {
		set->crtc->enabled = drm_helper_crtc_in_use(set->crtc);
		if (set->crtc->enabled) {
			DRM_DEBUG_KMS("attempting to set mode from"
					" userspace\n");
			drm_mode_debug_printmodeline(set->mode);
			old_fb = set->crtc->fb;
			set->crtc->fb = set->fb;
			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
						      set->x, set->y,
						      old_fb)) {
				DRM_ERROR("failed to set mode on [CRTC:%d]\n",
					  set->crtc->base.id);
				set->crtc->fb = old_fb;
				ret = -EINVAL;
				goto fail;
			}
			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
			for (i = 0; i < set->num_connectors; i++) {
				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
					      drm_get_connector_name(set->connectors[i]));
				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
			}
		}
		drm_helper_disable_unused_functions(dev);
	} else if (fb_changed) {
		set->crtc->x = set->x;
		set->crtc->y = set->y;

		old_fb = set->crtc->fb;
		if (set->crtc->fb != set->fb)
			set->crtc->fb = set->fb;
		ret = crtc_funcs->mode_set_base(set->crtc,
						set->x, set->y, old_fb);
		if (ret != 0) {
			set->crtc->fb = old_fb;
			goto fail;
		}
	}

	kfree(save_connectors);
	kfree(save_encoders);
	kfree(save_crtcs);
	return 0;

fail:
	/* Restore all previous data. */
	count = 0;
	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
		*crtc = save_crtcs[count++];
	}

	count = 0;
	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
		*encoder = save_encoders[count++];
	}

	count = 0;
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		*connector = save_connectors[count++];
	}

	/* Try to restore the config */
	if (mode_changed &&
	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
				      save_set.y, save_set.fb))
		DRM_ERROR("failed to restore config after modeset failure\n");

	kfree(save_connectors);
	kfree(save_encoders);
	kfree(save_crtcs);
	return ret;
}
EXPORT_SYMBOL(drm_crtc_helper_set_config);

static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
{
	int dpms = DRM_MODE_DPMS_OFF;
	struct drm_connector *connector;
	struct drm_device *dev = encoder->dev;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
		if (connector->encoder == encoder)
			if (connector->dpms < dpms)
				dpms = connector->dpms;
	return dpms;
}

static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
{
	int dpms = DRM_MODE_DPMS_OFF;
	struct drm_connector *connector;
	struct drm_device *dev = crtc->dev;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
		if (connector->encoder && connector->encoder->crtc == crtc)
			if (connector->dpms < dpms)
				dpms = connector->dpms;
	return dpms;
}

/**
 * drm_helper_connector_dpms
 * @connector affected connector
 * @mode DPMS mode
 *
 * Calls the low-level connector DPMS function, then
 * calls appropriate encoder and crtc DPMS functions as well
 */
void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
{
	struct drm_encoder *encoder = connector->encoder;
	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
	int old_dpms;

	if (mode == connector->dpms)
		return;

	old_dpms = connector->dpms;
	connector->dpms = mode;

	/* from off to on, do crtc then encoder */
	if (mode < old_dpms) {
		if (crtc) {
			struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
			if (crtc_funcs->dpms)
				(*crtc_funcs->dpms) (crtc,
						     drm_helper_choose_crtc_dpms(crtc));
		}
		if (encoder) {
			struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
			if (encoder_funcs->dpms)
				(*encoder_funcs->dpms) (encoder,
							drm_helper_choose_encoder_dpms(encoder));
		}
	}

	/* from on to off, do encoder then crtc */
	if (mode > old_dpms) {
		if (encoder) {
			struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
			if (encoder_funcs->dpms)
				(*encoder_funcs->dpms) (encoder,
							drm_helper_choose_encoder_dpms(encoder));
		}
		if (crtc) {
			struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
			if (crtc_funcs->dpms)
				(*crtc_funcs->dpms) (crtc,
						     drm_helper_choose_crtc_dpms(crtc));
		}
	}

	return;
}
EXPORT_SYMBOL(drm_helper_connector_dpms);

int drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
				   struct drm_mode_fb_cmd2 *mode_cmd)
{
	int i;

	fb->width = mode_cmd->width;
	fb->height = mode_cmd->height;
	for (i = 0; i < 4; i++) {
		fb->pitches[i] = mode_cmd->pitches[i];
		fb->offsets[i] = mode_cmd->offsets[i];
	}
	drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
				    &fb->bits_per_pixel);
	fb->pixel_format = mode_cmd->pixel_format;

	return 0;
}
EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);

int drm_helper_resume_force_mode(struct drm_device *dev)
{
	struct drm_crtc *crtc;
	struct drm_encoder *encoder;
	struct drm_encoder_helper_funcs *encoder_funcs;
	struct drm_crtc_helper_funcs *crtc_funcs;
	int ret;

	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {

		if (!crtc->enabled)
			continue;

		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
					       crtc->x, crtc->y, crtc->fb);

		if (ret == false)
			DRM_ERROR("failed to set mode on crtc %p\n", crtc);

		/* Turn off outputs that were already powered off */
		if (drm_helper_choose_crtc_dpms(crtc)) {
			list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

				if(encoder->crtc != crtc)
					continue;

				encoder_funcs = encoder->helper_private;
				if (encoder_funcs->dpms)
					(*encoder_funcs->dpms) (encoder,
								drm_helper_choose_encoder_dpms(encoder));
			}

			crtc_funcs = crtc->helper_private;
			if (crtc_funcs->dpms)
				(*crtc_funcs->dpms) (crtc,
						     drm_helper_choose_crtc_dpms(crtc));
		}
	}
	/* disable the unused connectors while restoring the modesetting */
	drm_helper_disable_unused_functions(dev);
	return 0;
}
EXPORT_SYMBOL(drm_helper_resume_force_mode);

#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
static void output_poll_execute(struct work_struct *work)
{
	struct delayed_work *delayed_work = to_delayed_work(work);
	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
	struct drm_connector *connector;
	enum drm_connector_status old_status;
	bool repoll = false, changed = false;

	if (!drm_kms_helper_poll)
		return;

	mutex_lock(&dev->mode_config.mutex);
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {

		/* if this is HPD or polled don't check it -
		   TV out for instance */
		if (!connector->polled)
			continue;

		else if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT))
			repoll = true;

		old_status = connector->status;
		/* if we are connected and don't want to poll for disconnect
		   skip it */
		if (old_status == connector_status_connected &&
		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT) &&
		    !(connector->polled & DRM_CONNECTOR_POLL_HPD))
			continue;

		connector->status = connector->funcs->detect(connector, false);
		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
			      connector->base.id,
			      drm_get_connector_name(connector),
			      old_status, connector->status);
		if (old_status != connector->status)
			changed = true;
	}

	mutex_unlock(&dev->mode_config.mutex);

	if (changed) {
		/* send a uevent + call fbdev */
		drm_sysfs_hotplug_event(dev);
		if (dev->mode_config.funcs->output_poll_changed)
			dev->mode_config.funcs->output_poll_changed(dev);
	}

	if (repoll)
		queue_delayed_work(system_nrt_wq, delayed_work, DRM_OUTPUT_POLL_PERIOD);
}

void drm_kms_helper_poll_disable(struct drm_device *dev)
{
	if (!dev->mode_config.poll_enabled)
		return;
	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
}
EXPORT_SYMBOL(drm_kms_helper_poll_disable);

void drm_kms_helper_poll_enable(struct drm_device *dev)
{
	bool poll = false;
	struct drm_connector *connector;

	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
		return;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		if (connector->polled)
			poll = true;
	}

	if (poll)
		queue_delayed_work(system_nrt_wq, &dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
}
EXPORT_SYMBOL(drm_kms_helper_poll_enable);

void drm_kms_helper_poll_init(struct drm_device *dev)
{
	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
	dev->mode_config.poll_enabled = true;

	drm_kms_helper_poll_enable(dev);
}
EXPORT_SYMBOL(drm_kms_helper_poll_init);

void drm_kms_helper_poll_fini(struct drm_device *dev)
{
	drm_kms_helper_poll_disable(dev);
}
EXPORT_SYMBOL(drm_kms_helper_poll_fini);

void drm_helper_hpd_irq_event(struct drm_device *dev)
{
	if (!dev->mode_config.poll_enabled)
		return;

	/* kill timer and schedule immediate execution, this doesn't block */
	cancel_delayed_work(&dev->mode_config.output_poll_work);
	if (drm_kms_helper_poll)
		queue_delayed_work(system_nrt_wq, &dev->mode_config.output_poll_work, 0);
}
EXPORT_SYMBOL(drm_helper_hpd_irq_event);


/**
 * drm_format_num_planes - get the number of planes for format
 * @format: pixel format (DRM_FORMAT_*)
 *
 * RETURNS:
 * The number of planes used by the specified pixel format.
 */
int drm_format_num_planes(uint32_t format)
{
	switch (format) {
	case DRM_FORMAT_YUV410:
	case DRM_FORMAT_YVU410:
	case DRM_FORMAT_YUV411:
	case DRM_FORMAT_YVU411:
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YUV422:
	case DRM_FORMAT_YVU422:
	case DRM_FORMAT_YUV444:
	case DRM_FORMAT_YVU444:
		return 3;
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
		return 2;
	default:
		return 1;
	}
}
EXPORT_SYMBOL(drm_format_num_planes);