Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  ISA Plug & Play support
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *  Changelog:
 *  2000-01-01	Added quirks handling for buggy hardware
 *		Peter Denison <peterd@pnd-pc.demon.co.uk>
 *  2000-06-14	Added isapnp_probe_devs() and isapnp_activate_dev()
 *		Christoph Hellwig <hch@infradead.org>
 *  2001-06-03  Added release_region calls to correspond with
 *		request_region calls when a failure occurs.  Also
 *		added KERN_* constants to printk() calls.
 *  2001-11-07  Added isapnp_{,un}register_driver calls along the lines
 *              of the pci driver interface
 *              Kai Germaschewski <kai.germaschewski@gmx.de>
 *  2002-06-06  Made the use of dma channel 0 configurable
 *              Gerald Teschl <gerald.teschl@univie.ac.at>
 *  2002-10-06  Ported to PnP Layer - Adam Belay <ambx1@neo.rr.com>
 *  2003-08-11	Resource Management Updates - Adam Belay <ambx1@neo.rr.com>
 */

#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/isapnp.h>
#include <linux/mutex.h>
#include <asm/io.h>

#include "../base.h"

#if 0
#define ISAPNP_REGION_OK
#endif

int isapnp_disable;		/* Disable ISA PnP */
static int isapnp_rdp;		/* Read Data Port */
static int isapnp_reset = 1;	/* reset all PnP cards (deactivate) */
static int isapnp_verbose = 1;	/* verbose mode */

module_param(isapnp_disable, int, 0);
MODULE_PARM_DESC(isapnp_disable, "ISA Plug & Play disable");
module_param(isapnp_rdp, int, 0);
MODULE_PARM_DESC(isapnp_rdp, "ISA Plug & Play read data port");
module_param(isapnp_reset, int, 0);
MODULE_PARM_DESC(isapnp_reset, "ISA Plug & Play reset all cards");
module_param(isapnp_verbose, int, 0);
MODULE_PARM_DESC(isapnp_verbose, "ISA Plug & Play verbose mode");

#define _PIDXR		0x279
#define _PNPWRP		0xa79

/* short tags */
#define _STAG_PNPVERNO		0x01
#define _STAG_LOGDEVID		0x02
#define _STAG_COMPATDEVID	0x03
#define _STAG_IRQ		0x04
#define _STAG_DMA		0x05
#define _STAG_STARTDEP		0x06
#define _STAG_ENDDEP		0x07
#define _STAG_IOPORT		0x08
#define _STAG_FIXEDIO		0x09
#define _STAG_VENDOR		0x0e
#define _STAG_END		0x0f
/* long tags */
#define _LTAG_MEMRANGE		0x81
#define _LTAG_ANSISTR		0x82
#define _LTAG_UNICODESTR	0x83
#define _LTAG_VENDOR		0x84
#define _LTAG_MEM32RANGE	0x85
#define _LTAG_FIXEDMEM32RANGE	0x86

/* Logical device control and configuration registers */

#define ISAPNP_CFG_ACTIVATE	0x30	/* byte */
#define ISAPNP_CFG_MEM		0x40	/* 4 * dword */
#define ISAPNP_CFG_PORT		0x60	/* 8 * word */
#define ISAPNP_CFG_IRQ		0x70	/* 2 * word */
#define ISAPNP_CFG_DMA		0x74	/* 2 * byte */

/*
 * Sizes of ISAPNP logical device configuration register sets.
 * See PNP-ISA-v1.0a.pdf, Appendix A.
 */
#define ISAPNP_MAX_MEM		4
#define ISAPNP_MAX_PORT		8
#define ISAPNP_MAX_IRQ		2
#define ISAPNP_MAX_DMA		2

static unsigned char isapnp_checksum_value;
static DEFINE_MUTEX(isapnp_cfg_mutex);
static int isapnp_csn_count;

/* some prototypes */

static inline void write_data(unsigned char x)
{
	outb(x, _PNPWRP);
}

static inline void write_address(unsigned char x)
{
	outb(x, _PIDXR);
	udelay(20);
}

static inline unsigned char read_data(void)
{
	unsigned char val = inb(isapnp_rdp);
	return val;
}

unsigned char isapnp_read_byte(unsigned char idx)
{
	write_address(idx);
	return read_data();
}

static unsigned short isapnp_read_word(unsigned char idx)
{
	unsigned short val;

	val = isapnp_read_byte(idx);
	val = (val << 8) + isapnp_read_byte(idx + 1);
	return val;
}

void isapnp_write_byte(unsigned char idx, unsigned char val)
{
	write_address(idx);
	write_data(val);
}

static void isapnp_write_word(unsigned char idx, unsigned short val)
{
	isapnp_write_byte(idx, val >> 8);
	isapnp_write_byte(idx + 1, val);
}

static void isapnp_key(void)
{
	unsigned char code = 0x6a, msb;
	int i;

	mdelay(1);
	write_address(0x00);
	write_address(0x00);

	write_address(code);

	for (i = 1; i < 32; i++) {
		msb = ((code & 0x01) ^ ((code & 0x02) >> 1)) << 7;
		code = (code >> 1) | msb;
		write_address(code);
	}
}

/* place all pnp cards in wait-for-key state */
static void isapnp_wait(void)
{
	isapnp_write_byte(0x02, 0x02);
}

static void isapnp_wake(unsigned char csn)
{
	isapnp_write_byte(0x03, csn);
}

static void isapnp_device(unsigned char logdev)
{
	isapnp_write_byte(0x07, logdev);
}

static void isapnp_activate(unsigned char logdev)
{
	isapnp_device(logdev);
	isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 1);
	udelay(250);
}

static void isapnp_deactivate(unsigned char logdev)
{
	isapnp_device(logdev);
	isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 0);
	udelay(500);
}

static void __init isapnp_peek(unsigned char *data, int bytes)
{
	int i, j;
	unsigned char d = 0;

	for (i = 1; i <= bytes; i++) {
		for (j = 0; j < 20; j++) {
			d = isapnp_read_byte(0x05);
			if (d & 1)
				break;
			udelay(100);
		}
		if (!(d & 1)) {
			if (data != NULL)
				*data++ = 0xff;
			continue;
		}
		d = isapnp_read_byte(0x04);	/* PRESDI */
		isapnp_checksum_value += d;
		if (data != NULL)
			*data++ = d;
	}
}

#define RDP_STEP	32	/* minimum is 4 */

static int isapnp_next_rdp(void)
{
	int rdp = isapnp_rdp;
	static int old_rdp = 0;

	if (old_rdp) {
		release_region(old_rdp, 1);
		old_rdp = 0;
	}
	while (rdp <= 0x3ff) {
		/*
		 *      We cannot use NE2000 probe spaces for ISAPnP or we
		 *      will lock up machines.
		 */
		if ((rdp < 0x280 || rdp > 0x380)
		    && request_region(rdp, 1, "ISAPnP")) {
			isapnp_rdp = rdp;
			old_rdp = rdp;
			return 0;
		}
		rdp += RDP_STEP;
	}
	return -1;
}

/* Set read port address */
static inline void isapnp_set_rdp(void)
{
	isapnp_write_byte(0x00, isapnp_rdp >> 2);
	udelay(100);
}

/*
 *	Perform an isolation. The port selection code now tries to avoid
 *	"dangerous to read" ports.
 */
static int __init isapnp_isolate_rdp_select(void)
{
	isapnp_wait();
	isapnp_key();

	/* Control: reset CSN and conditionally everything else too */
	isapnp_write_byte(0x02, isapnp_reset ? 0x05 : 0x04);
	mdelay(2);

	isapnp_wait();
	isapnp_key();
	isapnp_wake(0x00);

	if (isapnp_next_rdp() < 0) {
		isapnp_wait();
		return -1;
	}

	isapnp_set_rdp();
	udelay(1000);
	write_address(0x01);
	udelay(1000);
	return 0;
}

/*
 *  Isolate (assign uniqued CSN) to all ISA PnP devices.
 */
static int __init isapnp_isolate(void)
{
	unsigned char checksum = 0x6a;
	unsigned char chksum = 0x00;
	unsigned char bit = 0x00;
	int data;
	int csn = 0;
	int i;
	int iteration = 1;

	isapnp_rdp = 0x213;
	if (isapnp_isolate_rdp_select() < 0)
		return -1;

	while (1) {
		for (i = 1; i <= 64; i++) {
			data = read_data() << 8;
			udelay(250);
			data = data | read_data();
			udelay(250);
			if (data == 0x55aa)
				bit = 0x01;
			checksum =
			    ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
			    | (checksum >> 1);
			bit = 0x00;
		}
		for (i = 65; i <= 72; i++) {
			data = read_data() << 8;
			udelay(250);
			data = data | read_data();
			udelay(250);
			if (data == 0x55aa)
				chksum |= (1 << (i - 65));
		}
		if (checksum != 0x00 && checksum == chksum) {
			csn++;

			isapnp_write_byte(0x06, csn);
			udelay(250);
			iteration++;
			isapnp_wake(0x00);
			isapnp_set_rdp();
			udelay(1000);
			write_address(0x01);
			udelay(1000);
			goto __next;
		}
		if (iteration == 1) {
			isapnp_rdp += RDP_STEP;
			if (isapnp_isolate_rdp_select() < 0)
				return -1;
		} else if (iteration > 1) {
			break;
		}
__next:
		if (csn == 255)
			break;
		checksum = 0x6a;
		chksum = 0x00;
		bit = 0x00;
	}
	isapnp_wait();
	isapnp_csn_count = csn;
	return csn;
}

/*
 *  Read one tag from stream.
 */
static int __init isapnp_read_tag(unsigned char *type, unsigned short *size)
{
	unsigned char tag, tmp[2];

	isapnp_peek(&tag, 1);
	if (tag == 0)		/* invalid tag */
		return -1;
	if (tag & 0x80) {	/* large item */
		*type = tag;
		isapnp_peek(tmp, 2);
		*size = (tmp[1] << 8) | tmp[0];
	} else {
		*type = (tag >> 3) & 0x0f;
		*size = tag & 0x07;
	}
	if (*type == 0xff && *size == 0xffff)	/* probably invalid data */
		return -1;
	return 0;
}

/*
 *  Skip specified number of bytes from stream.
 */
static void __init isapnp_skip_bytes(int count)
{
	isapnp_peek(NULL, count);
}

/*
 *  Parse logical device tag.
 */
static struct pnp_dev *__init isapnp_parse_device(struct pnp_card *card,
						  int size, int number)
{
	unsigned char tmp[6];
	struct pnp_dev *dev;
	u32 eisa_id;
	char id[8];

	isapnp_peek(tmp, size);
	eisa_id = tmp[0] | tmp[1] << 8 | tmp[2] << 16 | tmp[3] << 24;
	pnp_eisa_id_to_string(eisa_id, id);

	dev = pnp_alloc_dev(&isapnp_protocol, number, id);
	if (!dev)
		return NULL;

	dev->card = card;
	dev->capabilities |= PNP_CONFIGURABLE;
	dev->capabilities |= PNP_READ;
	dev->capabilities |= PNP_WRITE;
	dev->capabilities |= PNP_DISABLE;
	pnp_init_resources(dev);
	return dev;
}

/*
 *  Add IRQ resource to resources list.
 */
static void __init isapnp_parse_irq_resource(struct pnp_dev *dev,
					     unsigned int option_flags,
					     int size)
{
	unsigned char tmp[3];
	unsigned long bits;
	pnp_irq_mask_t map;
	unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;

	isapnp_peek(tmp, size);
	bits = (tmp[1] << 8) | tmp[0];

	bitmap_zero(map.bits, PNP_IRQ_NR);
	bitmap_copy(map.bits, &bits, 16);

	if (size > 2)
		flags = tmp[2];

	pnp_register_irq_resource(dev, option_flags, &map, flags);
}

/*
 *  Add DMA resource to resources list.
 */
static void __init isapnp_parse_dma_resource(struct pnp_dev *dev,
					     unsigned int option_flags,
					     int size)
{
	unsigned char tmp[2];

	isapnp_peek(tmp, size);
	pnp_register_dma_resource(dev, option_flags, tmp[0], tmp[1]);
}

/*
 *  Add port resource to resources list.
 */
static void __init isapnp_parse_port_resource(struct pnp_dev *dev,
					      unsigned int option_flags,
					      int size)
{
	unsigned char tmp[7];
	resource_size_t min, max, align, len;
	unsigned char flags;

	isapnp_peek(tmp, size);
	min = (tmp[2] << 8) | tmp[1];
	max = (tmp[4] << 8) | tmp[3];
	align = tmp[5];
	len = tmp[6];
	flags = tmp[0] ? IORESOURCE_IO_16BIT_ADDR : 0;
	pnp_register_port_resource(dev, option_flags,
				   min, max, align, len, flags);
}

/*
 *  Add fixed port resource to resources list.
 */
static void __init isapnp_parse_fixed_port_resource(struct pnp_dev *dev,
						    unsigned int option_flags,
						    int size)
{
	unsigned char tmp[3];
	resource_size_t base, len;

	isapnp_peek(tmp, size);
	base = (tmp[1] << 8) | tmp[0];
	len = tmp[2];
	pnp_register_port_resource(dev, option_flags, base, base, 0, len,
				   IORESOURCE_IO_FIXED);
}

/*
 *  Add memory resource to resources list.
 */
static void __init isapnp_parse_mem_resource(struct pnp_dev *dev,
					     unsigned int option_flags,
					     int size)
{
	unsigned char tmp[9];
	resource_size_t min, max, align, len;
	unsigned char flags;

	isapnp_peek(tmp, size);
	min = ((tmp[2] << 8) | tmp[1]) << 8;
	max = ((tmp[4] << 8) | tmp[3]) << 8;
	align = (tmp[6] << 8) | tmp[5];
	len = ((tmp[8] << 8) | tmp[7]) << 8;
	flags = tmp[0];
	pnp_register_mem_resource(dev, option_flags,
				  min, max, align, len, flags);
}

/*
 *  Add 32-bit memory resource to resources list.
 */
static void __init isapnp_parse_mem32_resource(struct pnp_dev *dev,
					       unsigned int option_flags,
					       int size)
{
	unsigned char tmp[17];
	resource_size_t min, max, align, len;
	unsigned char flags;

	isapnp_peek(tmp, size);
	min = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
	max = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
	align = (tmp[12] << 24) | (tmp[11] << 16) | (tmp[10] << 8) | tmp[9];
	len = (tmp[16] << 24) | (tmp[15] << 16) | (tmp[14] << 8) | tmp[13];
	flags = tmp[0];
	pnp_register_mem_resource(dev, option_flags,
				  min, max, align, len, flags);
}

/*
 *  Add 32-bit fixed memory resource to resources list.
 */
static void __init isapnp_parse_fixed_mem32_resource(struct pnp_dev *dev,
						     unsigned int option_flags,
						     int size)
{
	unsigned char tmp[9];
	resource_size_t base, len;
	unsigned char flags;

	isapnp_peek(tmp, size);
	base = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
	len = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
	flags = tmp[0];
	pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
}

/*
 *  Parse card name for ISA PnP device.
 */
static void __init
isapnp_parse_name(char *name, unsigned int name_max, unsigned short *size)
{
	if (name[0] == '\0') {
		unsigned short size1 =
		    *size >= name_max ? (name_max - 1) : *size;
		isapnp_peek(name, size1);
		name[size1] = '\0';
		*size -= size1;

		/* clean whitespace from end of string */
		while (size1 > 0 && name[--size1] == ' ')
			name[size1] = '\0';
	}
}

/*
 *  Parse resource map for logical device.
 */
static int __init isapnp_create_device(struct pnp_card *card,
				       unsigned short size)
{
	int number = 0, skip = 0, priority, compat = 0;
	unsigned char type, tmp[17];
	unsigned int option_flags;
	struct pnp_dev *dev;
	u32 eisa_id;
	char id[8];

	if ((dev = isapnp_parse_device(card, size, number++)) == NULL)
		return 1;
	option_flags = 0;
	pnp_add_card_device(card, dev);

	while (1) {
		if (isapnp_read_tag(&type, &size) < 0)
			return 1;
		if (skip && type != _STAG_LOGDEVID && type != _STAG_END)
			goto __skip;
		switch (type) {
		case _STAG_LOGDEVID:
			if (size >= 5 && size <= 6) {
				if ((dev =
				     isapnp_parse_device(card, size,
							 number++)) == NULL)
					return 1;
				size = 0;
				skip = 0;
				option_flags = 0;
				pnp_add_card_device(card, dev);
			} else {
				skip = 1;
			}
			compat = 0;
			break;
		case _STAG_COMPATDEVID:
			if (size == 4 && compat < DEVICE_COUNT_COMPATIBLE) {
				isapnp_peek(tmp, 4);
				eisa_id = tmp[0] | tmp[1] << 8 |
					  tmp[2] << 16 | tmp[3] << 24;
				pnp_eisa_id_to_string(eisa_id, id);
				pnp_add_id(dev, id);
				compat++;
				size = 0;
			}
			break;
		case _STAG_IRQ:
			if (size < 2 || size > 3)
				goto __skip;
			isapnp_parse_irq_resource(dev, option_flags, size);
			size = 0;
			break;
		case _STAG_DMA:
			if (size != 2)
				goto __skip;
			isapnp_parse_dma_resource(dev, option_flags, size);
			size = 0;
			break;
		case _STAG_STARTDEP:
			if (size > 1)
				goto __skip;
			priority = PNP_RES_PRIORITY_ACCEPTABLE;
			if (size > 0) {
				isapnp_peek(tmp, size);
				priority = tmp[0];
				size = 0;
			}
			option_flags = pnp_new_dependent_set(dev, priority);
			break;
		case _STAG_ENDDEP:
			if (size != 0)
				goto __skip;
			option_flags = 0;
			break;
		case _STAG_IOPORT:
			if (size != 7)
				goto __skip;
			isapnp_parse_port_resource(dev, option_flags, size);
			size = 0;
			break;
		case _STAG_FIXEDIO:
			if (size != 3)
				goto __skip;
			isapnp_parse_fixed_port_resource(dev, option_flags,
							 size);
			size = 0;
			break;
		case _STAG_VENDOR:
			break;
		case _LTAG_MEMRANGE:
			if (size != 9)
				goto __skip;
			isapnp_parse_mem_resource(dev, option_flags, size);
			size = 0;
			break;
		case _LTAG_ANSISTR:
			isapnp_parse_name(dev->name, sizeof(dev->name), &size);
			break;
		case _LTAG_UNICODESTR:
			/* silently ignore */
			/* who use unicode for hardware identification? */
			break;
		case _LTAG_VENDOR:
			break;
		case _LTAG_MEM32RANGE:
			if (size != 17)
				goto __skip;
			isapnp_parse_mem32_resource(dev, option_flags, size);
			size = 0;
			break;
		case _LTAG_FIXEDMEM32RANGE:
			if (size != 9)
				goto __skip;
			isapnp_parse_fixed_mem32_resource(dev, option_flags,
							  size);
			size = 0;
			break;
		case _STAG_END:
			if (size > 0)
				isapnp_skip_bytes(size);
			return 1;
		default:
			dev_err(&dev->dev, "unknown tag %#x (card %i), "
				"ignored\n", type, card->number);
		}
__skip:
		if (size > 0)
			isapnp_skip_bytes(size);
	}
	return 0;
}

/*
 *  Parse resource map for ISA PnP card.
 */
static void __init isapnp_parse_resource_map(struct pnp_card *card)
{
	unsigned char type, tmp[17];
	unsigned short size;

	while (1) {
		if (isapnp_read_tag(&type, &size) < 0)
			return;
		switch (type) {
		case _STAG_PNPVERNO:
			if (size != 2)
				goto __skip;
			isapnp_peek(tmp, 2);
			card->pnpver = tmp[0];
			card->productver = tmp[1];
			size = 0;
			break;
		case _STAG_LOGDEVID:
			if (size >= 5 && size <= 6) {
				if (isapnp_create_device(card, size) == 1)
					return;
				size = 0;
			}
			break;
		case _STAG_VENDOR:
			break;
		case _LTAG_ANSISTR:
			isapnp_parse_name(card->name, sizeof(card->name),
					  &size);
			break;
		case _LTAG_UNICODESTR:
			/* silently ignore */
			/* who use unicode for hardware identification? */
			break;
		case _LTAG_VENDOR:
			break;
		case _STAG_END:
			if (size > 0)
				isapnp_skip_bytes(size);
			return;
		default:
			dev_err(&card->dev, "unknown tag %#x, ignored\n",
			       type);
		}
__skip:
		if (size > 0)
			isapnp_skip_bytes(size);
	}
}

/*
 *  Compute ISA PnP checksum for first eight bytes.
 */
static unsigned char __init isapnp_checksum(unsigned char *data)
{
	int i, j;
	unsigned char checksum = 0x6a, bit, b;

	for (i = 0; i < 8; i++) {
		b = data[i];
		for (j = 0; j < 8; j++) {
			bit = 0;
			if (b & (1 << j))
				bit = 1;
			checksum =
			    ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
			    | (checksum >> 1);
		}
	}
	return checksum;
}

/*
 *  Build device list for all present ISA PnP devices.
 */
static int __init isapnp_build_device_list(void)
{
	int csn;
	unsigned char header[9], checksum;
	struct pnp_card *card;
	u32 eisa_id;
	char id[8];

	isapnp_wait();
	isapnp_key();
	for (csn = 1; csn <= isapnp_csn_count; csn++) {
		isapnp_wake(csn);
		isapnp_peek(header, 9);
		checksum = isapnp_checksum(header);
		eisa_id = header[0] | header[1] << 8 |
			  header[2] << 16 | header[3] << 24;
		pnp_eisa_id_to_string(eisa_id, id);
		card = pnp_alloc_card(&isapnp_protocol, csn, id);
		if (!card)
			continue;

		INIT_LIST_HEAD(&card->devices);
		card->serial =
		    (header[7] << 24) | (header[6] << 16) | (header[5] << 8) |
		    header[4];
		isapnp_checksum_value = 0x00;
		isapnp_parse_resource_map(card);
		if (isapnp_checksum_value != 0x00)
			dev_err(&card->dev, "invalid checksum %#x\n",
				isapnp_checksum_value);
		card->checksum = isapnp_checksum_value;

		pnp_add_card(card);
	}
	isapnp_wait();
	return 0;
}

/*
 *  Basic configuration routines.
 */

int isapnp_present(void)
{
	struct pnp_card *card;

	pnp_for_each_card(card) {
		if (card->protocol == &isapnp_protocol)
			return 1;
	}
	return 0;
}

int isapnp_cfg_begin(int csn, int logdev)
{
	if (csn < 1 || csn > isapnp_csn_count || logdev > 10)
		return -EINVAL;
	mutex_lock(&isapnp_cfg_mutex);
	isapnp_wait();
	isapnp_key();
	isapnp_wake(csn);
#if 0
	/* to avoid malfunction when the isapnptools package is used */
	/* we must set RDP to our value again */
	/* it is possible to set RDP only in the isolation phase */
	/*   Jens Thoms Toerring <Jens.Toerring@physik.fu-berlin.de> */
	isapnp_write_byte(0x02, 0x04);	/* clear CSN of card */
	mdelay(2);		/* is this necessary? */
	isapnp_wake(csn);	/* bring card into sleep state */
	isapnp_wake(0);		/* bring card into isolation state */
	isapnp_set_rdp();	/* reset the RDP port */
	udelay(1000);		/* delay 1000us */
	isapnp_write_byte(0x06, csn);	/* reset CSN to previous value */
	udelay(250);		/* is this necessary? */
#endif
	if (logdev >= 0)
		isapnp_device(logdev);
	return 0;
}

int isapnp_cfg_end(void)
{
	isapnp_wait();
	mutex_unlock(&isapnp_cfg_mutex);
	return 0;
}

/*
 *  Initialization.
 */

EXPORT_SYMBOL(isapnp_protocol);
EXPORT_SYMBOL(isapnp_present);
EXPORT_SYMBOL(isapnp_cfg_begin);
EXPORT_SYMBOL(isapnp_cfg_end);
EXPORT_SYMBOL(isapnp_write_byte);

static int isapnp_get_resources(struct pnp_dev *dev)
{
	int i, ret;

	pnp_dbg(&dev->dev, "get resources\n");
	pnp_init_resources(dev);
	isapnp_cfg_begin(dev->card->number, dev->number);
	dev->active = isapnp_read_byte(ISAPNP_CFG_ACTIVATE);
	if (!dev->active)
		goto __end;

	for (i = 0; i < ISAPNP_MAX_PORT; i++) {
		ret = isapnp_read_word(ISAPNP_CFG_PORT + (i << 1));
		pnp_add_io_resource(dev, ret, ret,
				    ret == 0 ? IORESOURCE_DISABLED : 0);
	}
	for (i = 0; i < ISAPNP_MAX_MEM; i++) {
		ret = isapnp_read_word(ISAPNP_CFG_MEM + (i << 3)) << 8;
		pnp_add_mem_resource(dev, ret, ret,
				     ret == 0 ? IORESOURCE_DISABLED : 0);
	}
	for (i = 0; i < ISAPNP_MAX_IRQ; i++) {
		ret = isapnp_read_word(ISAPNP_CFG_IRQ + (i << 1)) >> 8;
		pnp_add_irq_resource(dev, ret,
				     ret == 0 ? IORESOURCE_DISABLED : 0);
	}
	for (i = 0; i < ISAPNP_MAX_DMA; i++) {
		ret = isapnp_read_byte(ISAPNP_CFG_DMA + i);
		pnp_add_dma_resource(dev, ret,
				     ret == 4 ? IORESOURCE_DISABLED : 0);
	}

__end:
	isapnp_cfg_end();
	return 0;
}

static int isapnp_set_resources(struct pnp_dev *dev)
{
	struct resource *res;
	int tmp;

	pnp_dbg(&dev->dev, "set resources\n");
	isapnp_cfg_begin(dev->card->number, dev->number);
	dev->active = 1;
	for (tmp = 0; tmp < ISAPNP_MAX_PORT; tmp++) {
		res = pnp_get_resource(dev, IORESOURCE_IO, tmp);
		if (pnp_resource_enabled(res)) {
			pnp_dbg(&dev->dev, "  set io  %d to %#llx\n",
				tmp, (unsigned long long) res->start);
			isapnp_write_word(ISAPNP_CFG_PORT + (tmp << 1),
					  res->start);
		}
	}
	for (tmp = 0; tmp < ISAPNP_MAX_IRQ; tmp++) {
		res = pnp_get_resource(dev, IORESOURCE_IRQ, tmp);
		if (pnp_resource_enabled(res)) {
			int irq = res->start;
			if (irq == 2)
				irq = 9;
			pnp_dbg(&dev->dev, "  set irq %d to %d\n", tmp, irq);
			isapnp_write_byte(ISAPNP_CFG_IRQ + (tmp << 1), irq);
		}
	}
	for (tmp = 0; tmp < ISAPNP_MAX_DMA; tmp++) {
		res = pnp_get_resource(dev, IORESOURCE_DMA, tmp);
		if (pnp_resource_enabled(res)) {
			pnp_dbg(&dev->dev, "  set dma %d to %lld\n",
				tmp, (unsigned long long) res->start);
			isapnp_write_byte(ISAPNP_CFG_DMA + tmp, res->start);
		}
	}
	for (tmp = 0; tmp < ISAPNP_MAX_MEM; tmp++) {
		res = pnp_get_resource(dev, IORESOURCE_MEM, tmp);
		if (pnp_resource_enabled(res)) {
			pnp_dbg(&dev->dev, "  set mem %d to %#llx\n",
				tmp, (unsigned long long) res->start);
			isapnp_write_word(ISAPNP_CFG_MEM + (tmp << 3),
					  (res->start >> 8) & 0xffff);
		}
	}
	/* FIXME: We aren't handling 32bit mems properly here */
	isapnp_activate(dev->number);
	isapnp_cfg_end();
	return 0;
}

static int isapnp_disable_resources(struct pnp_dev *dev)
{
	if (!dev->active)
		return -EINVAL;
	isapnp_cfg_begin(dev->card->number, dev->number);
	isapnp_deactivate(dev->number);
	dev->active = 0;
	isapnp_cfg_end();
	return 0;
}

struct pnp_protocol isapnp_protocol = {
	.name = "ISA Plug and Play",
	.get = isapnp_get_resources,
	.set = isapnp_set_resources,
	.disable = isapnp_disable_resources,
};

static int __init isapnp_init(void)
{
	int cards;
	struct pnp_card *card;
	struct pnp_dev *dev;

	if (isapnp_disable) {
		printk(KERN_INFO "isapnp: ISA Plug & Play support disabled\n");
		return 0;
	}
#ifdef CONFIG_PPC
	if (check_legacy_ioport(_PIDXR) || check_legacy_ioport(_PNPWRP))
		return -EINVAL;
#endif
#ifdef ISAPNP_REGION_OK
	if (!request_region(_PIDXR, 1, "isapnp index")) {
		printk(KERN_ERR "isapnp: Index Register 0x%x already used\n",
		       _PIDXR);
		return -EBUSY;
	}
#endif
	if (!request_region(_PNPWRP, 1, "isapnp write")) {
		printk(KERN_ERR
		       "isapnp: Write Data Register 0x%x already used\n",
		       _PNPWRP);
#ifdef ISAPNP_REGION_OK
		release_region(_PIDXR, 1);
#endif
		return -EBUSY;
	}

	if (pnp_register_protocol(&isapnp_protocol) < 0)
		return -EBUSY;

	/*
	 *      Print a message. The existing ISAPnP code is hanging machines
	 *      so let the user know where.
	 */

	printk(KERN_INFO "isapnp: Scanning for PnP cards...\n");
	if (isapnp_rdp >= 0x203 && isapnp_rdp <= 0x3ff) {
		isapnp_rdp |= 3;
		if (!request_region(isapnp_rdp, 1, "isapnp read")) {
			printk(KERN_ERR
			       "isapnp: Read Data Register 0x%x already used\n",
			       isapnp_rdp);
#ifdef ISAPNP_REGION_OK
			release_region(_PIDXR, 1);
#endif
			release_region(_PNPWRP, 1);
			return -EBUSY;
		}
		isapnp_set_rdp();
	}
	if (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff) {
		cards = isapnp_isolate();
		if (cards < 0 || (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff)) {
#ifdef ISAPNP_REGION_OK
			release_region(_PIDXR, 1);
#endif
			release_region(_PNPWRP, 1);
			printk(KERN_INFO
			       "isapnp: No Plug & Play device found\n");
			return 0;
		}
		request_region(isapnp_rdp, 1, "isapnp read");
	}
	isapnp_build_device_list();
	cards = 0;

	protocol_for_each_card(&isapnp_protocol, card) {
		cards++;
		if (isapnp_verbose) {
			dev_info(&card->dev, "card '%s'\n",
			       card->name[0] ? card->name : "unknown");
			if (isapnp_verbose < 2)
				continue;
			card_for_each_dev(card, dev) {
				dev_info(&card->dev, "device '%s'\n",
				       dev->name[0] ? dev->name : "unknown");
			}
		}
	}
	if (cards)
		printk(KERN_INFO
		       "isapnp: %i Plug & Play card%s detected total\n", cards,
		       cards > 1 ? "s" : "");
	else
		printk(KERN_INFO "isapnp: No Plug & Play card found\n");

	isapnp_proc_init();
	return 0;
}

device_initcall(isapnp_init);

/* format is: noisapnp */

static int __init isapnp_setup_disable(char *str)
{
	isapnp_disable = 1;
	return 1;
}

__setup("noisapnp", isapnp_setup_disable);

/* format is: isapnp=rdp,reset,skip_pci_scan,verbose */

static int __init isapnp_setup_isapnp(char *str)
{
	(void)((get_option(&str, &isapnp_rdp) == 2) &&
	       (get_option(&str, &isapnp_reset) == 2) &&
	       (get_option(&str, &isapnp_verbose) == 2));
	return 1;
}

__setup("isapnp=", isapnp_setup_isapnp);