Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   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
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
/*
 *  ec.c - ACPI Embedded Controller Driver (v2.1)
 *
 *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
 *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

/* Uncomment next line to get verbose printout */
/* #define DEBUG */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <linux/dmi.h>

#define ACPI_EC_CLASS			"embedded_controller"
#define ACPI_EC_DEVICE_NAME		"Embedded Controller"
#define ACPI_EC_FILE_INFO		"info"

#define PREFIX				"ACPI: EC: "

/* EC status register */
#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */

/* EC commands */
enum ec_command {
	ACPI_EC_COMMAND_READ = 0x80,
	ACPI_EC_COMMAND_WRITE = 0x81,
	ACPI_EC_BURST_ENABLE = 0x82,
	ACPI_EC_BURST_DISABLE = 0x83,
	ACPI_EC_COMMAND_QUERY = 0x84,
};

#define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
#define ACPI_EC_CDELAY		10	/* Wait 10us before polling EC */
#define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */

#define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
					   per one transaction */

enum {
	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
					 * OpReg are installed */
};

/* If we find an EC via the ECDT, we need to keep a ptr to its context */
/* External interfaces use first EC only, so remember */
typedef int (*acpi_ec_query_func) (void *data);

struct acpi_ec_query_handler {
	struct list_head node;
	acpi_ec_query_func func;
	acpi_handle handle;
	void *data;
	u8 query_bit;
};

struct transaction {
	const u8 *wdata;
	u8 *rdata;
	unsigned short irq_count;
	u8 command;
	u8 wi;
	u8 ri;
	u8 wlen;
	u8 rlen;
	bool done;
};

static struct acpi_ec {
	acpi_handle handle;
	unsigned long gpe;
	unsigned long command_addr;
	unsigned long data_addr;
	unsigned long global_lock;
	unsigned long flags;
	struct mutex lock;
	wait_queue_head_t wait;
	struct list_head list;
	struct transaction *curr;
	spinlock_t curr_lock;
} *boot_ec, *first_ec;

static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */

/* --------------------------------------------------------------------------
                             Transaction Management
   -------------------------------------------------------------------------- */

static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
{
	u8 x = inb(ec->command_addr);
	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
	return x;
}

static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
{
	u8 x = inb(ec->data_addr);
	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
	return x;
}

static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
{
	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
	outb(command, ec->command_addr);
}

static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
{
	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
	outb(data, ec->data_addr);
}

static int ec_transaction_done(struct acpi_ec *ec)
{
	unsigned long flags;
	int ret = 0;
	spin_lock_irqsave(&ec->curr_lock, flags);
	if (!ec->curr || ec->curr->done)
		ret = 1;
	spin_unlock_irqrestore(&ec->curr_lock, flags);
	return ret;
}

static void start_transaction(struct acpi_ec *ec)
{
	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
	ec->curr->done = false;
	acpi_ec_write_cmd(ec, ec->curr->command);
}

static void advance_transaction(struct acpi_ec *ec, u8 status)
{
	unsigned long flags;
	spin_lock_irqsave(&ec->curr_lock, flags);
	if (!ec->curr)
		goto unlock;
	if (ec->curr->wlen > ec->curr->wi) {
		if ((status & ACPI_EC_FLAG_IBF) == 0)
			acpi_ec_write_data(ec,
				ec->curr->wdata[ec->curr->wi++]);
		else
			goto err;
	} else if (ec->curr->rlen > ec->curr->ri) {
		if ((status & ACPI_EC_FLAG_OBF) == 1) {
			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
			if (ec->curr->rlen == ec->curr->ri)
				ec->curr->done = true;
		} else
			goto err;
	} else if (ec->curr->wlen == ec->curr->wi &&
		   (status & ACPI_EC_FLAG_IBF) == 0)
		ec->curr->done = true;
	goto unlock;
err:
	/* false interrupt, state didn't change */
	if (in_interrupt())
		++ec->curr->irq_count;
unlock:
	spin_unlock_irqrestore(&ec->curr_lock, flags);
}

static void acpi_ec_gpe_query(void *ec_cxt);

static int ec_check_sci(struct acpi_ec *ec, u8 state)
{
	if (state & ACPI_EC_FLAG_SCI) {
		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
			return acpi_os_execute(OSL_EC_BURST_HANDLER,
				acpi_ec_gpe_query, ec);
	}
	return 0;
}

static int ec_poll(struct acpi_ec *ec)
{
	unsigned long flags;
	int repeat = 2; /* number of command restarts */
	while (repeat--) {
		unsigned long delay = jiffies +
			msecs_to_jiffies(ACPI_EC_DELAY);
		do {
			/* don't sleep with disabled interrupts */
			if (EC_FLAGS_MSI || irqs_disabled()) {
				udelay(ACPI_EC_MSI_UDELAY);
				if (ec_transaction_done(ec))
					return 0;
			} else {
				if (wait_event_timeout(ec->wait,
						ec_transaction_done(ec),
						msecs_to_jiffies(1)))
					return 0;
			}
			advance_transaction(ec, acpi_ec_read_status(ec));
		} while (time_before(jiffies, delay));
		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
			break;
		pr_debug(PREFIX "controller reset, restart transaction\n");
		spin_lock_irqsave(&ec->curr_lock, flags);
		start_transaction(ec);
		spin_unlock_irqrestore(&ec->curr_lock, flags);
	}
	return -ETIME;
}

static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
					struct transaction *t)
{
	unsigned long tmp;
	int ret = 0;
	pr_debug(PREFIX "transaction start\n");
	/* disable GPE during transaction if storm is detected */
	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
		acpi_disable_gpe(NULL, ec->gpe);
	}
	if (EC_FLAGS_MSI)
		udelay(ACPI_EC_MSI_UDELAY);
	/* start transaction */
	spin_lock_irqsave(&ec->curr_lock, tmp);
	/* following two actions should be kept atomic */
	ec->curr = t;
	start_transaction(ec);
	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
	spin_unlock_irqrestore(&ec->curr_lock, tmp);
	ret = ec_poll(ec);
	pr_debug(PREFIX "transaction end\n");
	spin_lock_irqsave(&ec->curr_lock, tmp);
	ec->curr = NULL;
	spin_unlock_irqrestore(&ec->curr_lock, tmp);
	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
		/* check if we received SCI during transaction */
		ec_check_sci(ec, acpi_ec_read_status(ec));
		/* it is safe to enable GPE outside of transaction */
		acpi_enable_gpe(NULL, ec->gpe);
	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
		pr_info(PREFIX "GPE storm detected, "
			"transactions will use polling mode\n");
		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
	}
	return ret;
}

static int ec_check_ibf0(struct acpi_ec *ec)
{
	u8 status = acpi_ec_read_status(ec);
	return (status & ACPI_EC_FLAG_IBF) == 0;
}

static int ec_wait_ibf0(struct acpi_ec *ec)
{
	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
	/* interrupt wait manually if GPE mode is not active */
	while (time_before(jiffies, delay))
		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
					msecs_to_jiffies(1)))
			return 0;
	return -ETIME;
}

static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
{
	int status;
	u32 glk;
	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
		return -EINVAL;
	if (t->rdata)
		memset(t->rdata, 0, t->rlen);
	mutex_lock(&ec->lock);
	if (ec->global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status)) {
			status = -ENODEV;
			goto unlock;
		}
	}
	if (ec_wait_ibf0(ec)) {
		pr_err(PREFIX "input buffer is not empty, "
				"aborting transaction\n");
		status = -ETIME;
		goto end;
	}
	status = acpi_ec_transaction_unlocked(ec, t);
end:
	if (ec->global_lock)
		acpi_release_global_lock(glk);
unlock:
	mutex_unlock(&ec->lock);
	return status;
}

static int acpi_ec_burst_enable(struct acpi_ec *ec)
{
	u8 d;
	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
				.wdata = NULL, .rdata = &d,
				.wlen = 0, .rlen = 1};

	return acpi_ec_transaction(ec, &t);
}

static int acpi_ec_burst_disable(struct acpi_ec *ec)
{
	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
				.wdata = NULL, .rdata = NULL,
				.wlen = 0, .rlen = 0};

	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
				acpi_ec_transaction(ec, &t) : 0;
}

static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
{
	int result;
	u8 d;
	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
				.wdata = &address, .rdata = &d,
				.wlen = 1, .rlen = 1};

	result = acpi_ec_transaction(ec, &t);
	*data = d;
	return result;
}

static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
{
	u8 wdata[2] = { address, data };
	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
				.wdata = wdata, .rdata = NULL,
				.wlen = 2, .rlen = 0};

	return acpi_ec_transaction(ec, &t);
}

/*
 * Externally callable EC access functions. For now, assume 1 EC only
 */
int ec_burst_enable(void)
{
	if (!first_ec)
		return -ENODEV;
	return acpi_ec_burst_enable(first_ec);
}

EXPORT_SYMBOL(ec_burst_enable);

int ec_burst_disable(void)
{
	if (!first_ec)
		return -ENODEV;
	return acpi_ec_burst_disable(first_ec);
}

EXPORT_SYMBOL(ec_burst_disable);

int ec_read(u8 addr, u8 * val)
{
	int err;
	u8 temp_data;

	if (!first_ec)
		return -ENODEV;

	err = acpi_ec_read(first_ec, addr, &temp_data);

	if (!err) {
		*val = temp_data;
		return 0;
	} else
		return err;
}

EXPORT_SYMBOL(ec_read);

int ec_write(u8 addr, u8 val)
{
	int err;

	if (!first_ec)
		return -ENODEV;

	err = acpi_ec_write(first_ec, addr, val);

	return err;
}

EXPORT_SYMBOL(ec_write);

int ec_transaction(u8 command,
		   const u8 * wdata, unsigned wdata_len,
		   u8 * rdata, unsigned rdata_len,
		   int force_poll)
{
	struct transaction t = {.command = command,
				.wdata = wdata, .rdata = rdata,
				.wlen = wdata_len, .rlen = rdata_len};
	if (!first_ec)
		return -ENODEV;

	return acpi_ec_transaction(first_ec, &t);
}

EXPORT_SYMBOL(ec_transaction);

static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
{
	int result;
	u8 d;
	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
				.wdata = NULL, .rdata = &d,
				.wlen = 0, .rlen = 1};
	if (!ec || !data)
		return -EINVAL;

	/*
	 * Query the EC to find out which _Qxx method we need to evaluate.
	 * Note that successful completion of the query causes the ACPI_EC_SCI
	 * bit to be cleared (and thus clearing the interrupt source).
	 */

	result = acpi_ec_transaction(ec, &t);
	if (result)
		return result;

	if (!d)
		return -ENODATA;

	*data = d;
	return 0;
}

/* --------------------------------------------------------------------------
                                Event Management
   -------------------------------------------------------------------------- */
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
			      acpi_handle handle, acpi_ec_query_func func,
			      void *data)
{
	struct acpi_ec_query_handler *handler =
	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
	if (!handler)
		return -ENOMEM;

	handler->query_bit = query_bit;
	handler->handle = handle;
	handler->func = func;
	handler->data = data;
	mutex_lock(&ec->lock);
	list_add(&handler->node, &ec->list);
	mutex_unlock(&ec->lock);
	return 0;
}

EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);

void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
{
	struct acpi_ec_query_handler *handler, *tmp;
	mutex_lock(&ec->lock);
	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
		if (query_bit == handler->query_bit) {
			list_del(&handler->node);
			kfree(handler);
		}
	}
	mutex_unlock(&ec->lock);
}

EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);

static void acpi_ec_gpe_query(void *ec_cxt)
{
	struct acpi_ec *ec = ec_cxt;
	u8 value = 0;
	struct acpi_ec_query_handler *handler, copy;

	if (!ec || acpi_ec_query(ec, &value))
		return;
	mutex_lock(&ec->lock);
	list_for_each_entry(handler, &ec->list, node) {
		if (value == handler->query_bit) {
			/* have custom handler for this bit */
			memcpy(&copy, handler, sizeof(copy));
			mutex_unlock(&ec->lock);
			if (copy.func) {
				copy.func(copy.data);
			} else if (copy.handle) {
				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
			}
			return;
		}
	}
	mutex_unlock(&ec->lock);
}

static u32 acpi_ec_gpe_handler(void *data)
{
	struct acpi_ec *ec = data;
	u8 status;

	pr_debug(PREFIX "~~~> interrupt\n");
	status = acpi_ec_read_status(ec);

	advance_transaction(ec, status);
	if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
		wake_up(&ec->wait);
	ec_check_sci(ec, status);
	return ACPI_INTERRUPT_HANDLED;
}

/* --------------------------------------------------------------------------
                             Address Space Management
   -------------------------------------------------------------------------- */

static acpi_status
acpi_ec_space_handler(u32 function, acpi_physical_address address,
		      u32 bits, acpi_integer *value,
		      void *handler_context, void *region_context)
{
	struct acpi_ec *ec = handler_context;
	int result = 0, i;
	u8 temp = 0;

	if ((address > 0xFF) || !value || !handler_context)
		return AE_BAD_PARAMETER;

	if (function != ACPI_READ && function != ACPI_WRITE)
		return AE_BAD_PARAMETER;

	if (bits != 8 && acpi_strict)
		return AE_BAD_PARAMETER;

	if (EC_FLAGS_MSI)
		acpi_ec_burst_enable(ec);

	if (function == ACPI_READ) {
		result = acpi_ec_read(ec, address, &temp);
		*value = temp;
	} else {
		temp = 0xff & (*value);
		result = acpi_ec_write(ec, address, temp);
	}

	for (i = 8; unlikely(bits - i > 0); i += 8) {
		++address;
		if (function == ACPI_READ) {
			result = acpi_ec_read(ec, address, &temp);
			(*value) |= ((acpi_integer)temp) << i;
		} else {
			temp = 0xff & ((*value) >> i);
			result = acpi_ec_write(ec, address, temp);
		}
	}

	if (EC_FLAGS_MSI)
		acpi_ec_burst_disable(ec);

	switch (result) {
	case -EINVAL:
		return AE_BAD_PARAMETER;
		break;
	case -ENODEV:
		return AE_NOT_FOUND;
		break;
	case -ETIME:
		return AE_TIME;
		break;
	default:
		return AE_OK;
	}
}

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static struct proc_dir_entry *acpi_ec_dir;

static int acpi_ec_read_info(struct seq_file *seq, void *offset)
{
	struct acpi_ec *ec = seq->private;

	if (!ec)
		goto end;

	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
	seq_printf(seq, "use global lock:\t%s\n",
		   ec->global_lock ? "yes" : "no");
      end:
	return 0;
}

static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
}

static const struct file_operations acpi_ec_info_ops = {
	.open = acpi_ec_info_open_fs,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	.owner = THIS_MODULE,
};

static int acpi_ec_add_fs(struct acpi_device *device)
{
	struct proc_dir_entry *entry = NULL;

	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
						     acpi_ec_dir);
		if (!acpi_device_dir(device))
			return -ENODEV;
	}

	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
				 acpi_device_dir(device),
				 &acpi_ec_info_ops, acpi_driver_data(device));
	if (!entry)
		return -ENODEV;
	return 0;
}

static int acpi_ec_remove_fs(struct acpi_device *device)
{

	if (acpi_device_dir(device)) {
		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
		acpi_device_dir(device) = NULL;
	}

	return 0;
}

/* --------------------------------------------------------------------------
                               Driver Interface
   -------------------------------------------------------------------------- */
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context);

static struct acpi_ec *make_acpi_ec(void)
{
	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
	if (!ec)
		return NULL;
	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
	mutex_init(&ec->lock);
	init_waitqueue_head(&ec->wait);
	INIT_LIST_HEAD(&ec->list);
	spin_lock_init(&ec->curr_lock);
	return ec;
}

static acpi_status
acpi_ec_register_query_methods(acpi_handle handle, u32 level,
			       void *context, void **return_value)
{
	char node_name[5];
	struct acpi_buffer buffer = { sizeof(node_name), node_name };
	struct acpi_ec *ec = context;
	int value = 0;
	acpi_status status;

	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);

	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
	}
	return AE_OK;
}

static acpi_status
ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
{
	acpi_status status;
	unsigned long long tmp = 0;

	struct acpi_ec *ec = context;

	/* clear addr values, ec_parse_io_ports depend on it */
	ec->command_addr = ec->data_addr = 0;

	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
				     ec_parse_io_ports, ec);
	if (ACPI_FAILURE(status))
		return status;

	/* Get GPE bit assignment (EC events). */
	/* TODO: Add support for _GPE returning a package */
	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
	if (ACPI_FAILURE(status))
		return status;
	ec->gpe = tmp;
	/* Use the global lock for all EC transactions? */
	tmp = 0;
	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
	ec->global_lock = tmp;
	ec->handle = handle;
	return AE_CTRL_TERMINATE;
}

static int ec_install_handlers(struct acpi_ec *ec)
{
	acpi_status status;
	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
		return 0;
	status = acpi_install_gpe_handler(NULL, ec->gpe,
				  ACPI_GPE_EDGE_TRIGGERED,
				  &acpi_ec_gpe_handler, ec);
	if (ACPI_FAILURE(status))
		return -ENODEV;
	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
	acpi_enable_gpe(NULL, ec->gpe);
	status = acpi_install_address_space_handler(ec->handle,
						    ACPI_ADR_SPACE_EC,
						    &acpi_ec_space_handler,
						    NULL, ec);
	if (ACPI_FAILURE(status)) {
		if (status == AE_NOT_FOUND) {
			/*
			 * Maybe OS fails in evaluating the _REG object.
			 * The AE_NOT_FOUND error will be ignored and OS
			 * continue to initialize EC.
			 */
			printk(KERN_ERR "Fail in evaluating the _REG object"
				" of EC device. Broken bios is suspected.\n");
		} else {
			acpi_remove_gpe_handler(NULL, ec->gpe,
				&acpi_ec_gpe_handler);
			return -ENODEV;
		}
	}

	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
	return 0;
}

static void ec_remove_handlers(struct acpi_ec *ec)
{
	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
		pr_err(PREFIX "failed to remove space handler\n");
	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
				&acpi_ec_gpe_handler)))
		pr_err(PREFIX "failed to remove gpe handler\n");
	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
}

static int acpi_ec_add(struct acpi_device *device)
{
	struct acpi_ec *ec = NULL;
	int ret;

	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_EC_CLASS);

	/* Check for boot EC */
	if (boot_ec &&
	    (boot_ec->handle == device->handle ||
	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
		ec = boot_ec;
		boot_ec = NULL;
	} else {
		ec = make_acpi_ec();
		if (!ec)
			return -ENOMEM;
	}
	if (ec_parse_device(device->handle, 0, ec, NULL) !=
		AE_CTRL_TERMINATE) {
			kfree(ec);
			return -EINVAL;
	}

	ec->handle = device->handle;

	/* Find and register all query methods */
	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
			    acpi_ec_register_query_methods, ec, NULL);

	if (!first_ec)
		first_ec = ec;
	device->driver_data = ec;
	acpi_ec_add_fs(device);
	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
			  ec->gpe, ec->command_addr, ec->data_addr);

	ret = ec_install_handlers(ec);

	/* EC is fully operational, allow queries */
	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
	return ret;
}

static int acpi_ec_remove(struct acpi_device *device, int type)
{
	struct acpi_ec *ec;
	struct acpi_ec_query_handler *handler, *tmp;

	if (!device)
		return -EINVAL;

	ec = acpi_driver_data(device);
	ec_remove_handlers(ec);
	mutex_lock(&ec->lock);
	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
		list_del(&handler->node);
		kfree(handler);
	}
	mutex_unlock(&ec->lock);
	acpi_ec_remove_fs(device);
	device->driver_data = NULL;
	if (ec == first_ec)
		first_ec = NULL;
	kfree(ec);
	return 0;
}

static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context)
{
	struct acpi_ec *ec = context;

	if (resource->type != ACPI_RESOURCE_TYPE_IO)
		return AE_OK;

	/*
	 * The first address region returned is the data port, and
	 * the second address region returned is the status/command
	 * port.
	 */
	if (ec->data_addr == 0)
		ec->data_addr = resource->data.io.minimum;
	else if (ec->command_addr == 0)
		ec->command_addr = resource->data.io.minimum;
	else
		return AE_CTRL_TERMINATE;

	return AE_OK;
}

int __init acpi_boot_ec_enable(void)
{
	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
		return 0;
	if (!ec_install_handlers(boot_ec)) {
		first_ec = boot_ec;
		return 0;
	}
	return -EFAULT;
}

static const struct acpi_device_id ec_device_ids[] = {
	{"PNP0C09", 0},
	{"", 0},
};

/* Some BIOS do not survive early DSDT scan, skip it */
static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
{
	EC_FLAGS_SKIP_DSDT_SCAN = 1;
	return 0;
}

/* ASUStek often supplies us with broken ECDT, validate it */
static int ec_validate_ecdt(const struct dmi_system_id *id)
{
	EC_FLAGS_VALIDATE_ECDT = 1;
	return 0;
}

/* MSI EC needs special treatment, enable it */
static int ec_flag_msi(const struct dmi_system_id *id)
{
	EC_FLAGS_MSI = 1;
	EC_FLAGS_VALIDATE_ECDT = 1;
	return 0;
}

static struct dmi_system_id __initdata ec_dmi_table[] = {
	{
	ec_skip_dsdt_scan, "Compal JFL92", {
	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
	{
	ec_flag_msi, "MSI hardware", {
	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star"),
	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star") }, NULL},
	{
	ec_validate_ecdt, "ASUS hardware", {
	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
	{},
};


int __init acpi_ec_ecdt_probe(void)
{
	acpi_status status;
	struct acpi_ec *saved_ec = NULL;
	struct acpi_table_ecdt *ecdt_ptr;

	boot_ec = make_acpi_ec();
	if (!boot_ec)
		return -ENOMEM;
	/*
	 * Generate a boot ec context
	 */
	dmi_check_system(ec_dmi_table);
	status = acpi_get_table(ACPI_SIG_ECDT, 1,
				(struct acpi_table_header **)&ecdt_ptr);
	if (ACPI_SUCCESS(status)) {
		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
		boot_ec->command_addr = ecdt_ptr->control.address;
		boot_ec->data_addr = ecdt_ptr->data.address;
		boot_ec->gpe = ecdt_ptr->gpe;
		boot_ec->handle = ACPI_ROOT_OBJECT;
		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
		/* Don't trust ECDT, which comes from ASUSTek */
		if (!EC_FLAGS_VALIDATE_ECDT)
			goto install;
		saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
		if (!saved_ec)
			return -ENOMEM;
		memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
	/* fall through */
	}

	if (EC_FLAGS_SKIP_DSDT_SCAN)
		return -ENODEV;

	/* This workaround is needed only on some broken machines,
	 * which require early EC, but fail to provide ECDT */
	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
					boot_ec, NULL);
	/* Check that acpi_get_devices actually find something */
	if (ACPI_FAILURE(status) || !boot_ec->handle)
		goto error;
	if (saved_ec) {
		/* try to find good ECDT from ASUSTek */
		if (saved_ec->command_addr != boot_ec->command_addr ||
		    saved_ec->data_addr != boot_ec->data_addr ||
		    saved_ec->gpe != boot_ec->gpe ||
		    saved_ec->handle != boot_ec->handle)
			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
			"ECDT tables, which are very hard to workaround. "
			"Trying to use DSDT EC info instead. Please send "
			"output of acpidump to linux-acpi@vger.kernel.org\n");
		kfree(saved_ec);
		saved_ec = NULL;
	} else {
		/* We really need to limit this workaround, the only ASUS,
		* which needs it, has fake EC._INI method, so use it as flag.
		* Keep boot_ec struct as it will be needed soon.
		*/
		acpi_handle dummy;
		if (!dmi_name_in_vendors("ASUS") ||
		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
							&dummy)))
			return -ENODEV;
	}
install:
	if (!ec_install_handlers(boot_ec)) {
		first_ec = boot_ec;
		return 0;
	}
error:
	kfree(boot_ec);
	boot_ec = NULL;
	return -ENODEV;
}

static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
{
	struct acpi_ec *ec = acpi_driver_data(device);
	/* Stop using GPE */
	acpi_disable_gpe(NULL, ec->gpe);
	return 0;
}

static int acpi_ec_resume(struct acpi_device *device)
{
	struct acpi_ec *ec = acpi_driver_data(device);
	/* Enable use of GPE back */
	acpi_enable_gpe(NULL, ec->gpe);
	return 0;
}

static struct acpi_driver acpi_ec_driver = {
	.name = "ec",
	.class = ACPI_EC_CLASS,
	.ids = ec_device_ids,
	.ops = {
		.add = acpi_ec_add,
		.remove = acpi_ec_remove,
		.suspend = acpi_ec_suspend,
		.resume = acpi_ec_resume,
		},
};

int __init acpi_ec_init(void)
{
	int result = 0;

	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
	if (!acpi_ec_dir)
		return -ENODEV;

	/* Now register the driver for the EC */
	result = acpi_bus_register_driver(&acpi_ec_driver);
	if (result < 0) {
		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
		return -ENODEV;
	}

	return result;
}

/* EC driver currently not unloadable */
#if 0
static void __exit acpi_ec_exit(void)
{

	acpi_bus_unregister_driver(&acpi_ec_driver);

	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);

	return;
}
#endif	/* 0 */