Boot Linux faster!

Check our new training course

Boot Linux faster!

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

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
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
/* cm206.c. A linux-driver for the cm206 cdrom player with cm260 adapter card.
   Copyright (c) 1995--1997 David A. van Leeuwen.
   $Id: cm206.c,v 1.5 1997/12/26 11:02:51 david Exp $
   
     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., 675 Mass Ave, Cambridge, MA 02139, USA.

History:
 Started 25 jan 1994. Waiting for documentation...
 22 feb 1995: 0.1a first reasonably safe polling driver.
	      Two major bugs, one in read_sector and one in 
	      do_cm206_request, happened to cancel!
 25 feb 1995: 0.2a first reasonable interrupt driven version of above.
              uart writes are still done in polling mode. 
 25 feb 1995: 0.21a writes also in interrupt mode, still some
	      small bugs to be found... Larger buffer. 
  2 mrt 1995: 0.22 Bug found (cd-> nowhere, interrupt was called in
              initialization), read_ahead of 16. Timeouts implemented.
	      unclear if they do something...
  7 mrt 1995: 0.23 Start of background read-ahead.
 18 mrt 1995: 0.24 Working background read-ahead. (still problems)
 26 mrt 1995: 0.25 Multi-session ioctl added (kernel v1.2).
              Statistics implemented, though separate stats206.h.
	      Accessible trough ioctl 0x1000 (just a number).
	      Hard to choose between v1.2 development and 1.1.75.
	      Bottom-half doesn't work with 1.2...
	      0.25a: fixed... typo. Still problems...
  1 apr 1995: 0.26 Module support added. Most bugs found. Use kernel 1.2.n.
  5 apr 1995: 0.27 Auto-probe for the adapter card base address.
              Auto-probe for the adaptor card irq line.
  7 apr 1995: 0.28 Added lilo setup support for base address and irq.
              Use major number 32 (not in this source), officially
	      assigned to this driver.
  9 apr 1995: 0.29 Added very limited audio support. Toc_header, stop, pause,
              resume, eject. Play_track ignores track info, because we can't 
	      read a table-of-contents entry. Toc_entry is implemented
	      as a `placebo' function: always returns start of disc. 
  3 may 1995: 0.30 Audio support completed. The get_toc_entry function
              is implemented as a binary search. 
 15 may 1995: 0.31 More work on audio stuff. Workman is not easy to 
              satisfy; changed binary search into linear search.
	      Auto-probe for base address somewhat relaxed.
  1 jun 1995: 0.32 Removed probe_irq_on/off for module version.
 10 jun 1995: 0.33 Workman still behaves funny, but you should be
              able to eject and substitute another disc.

 An adaptation of 0.33 is included in linux-1.3.7 by Eberhard Moenkeberg

 18 jul 1995: 0.34 Patch by Heiko Eissfeldt included, mainly considering 
              verify_area's in the ioctls. Some bugs introduced by 
	      EM considering the base port and irq fixed. 

 18 dec 1995: 0.35 Add some code for error checking... no luck...

 We jump to reach our goal: version 1.0 in the next stable linux kernel.

 19 mar 1996: 0.95 Different implementation of CDROM_GET_UPC, on
	      request of Thomas Quinot. 
 25 mar 1996: 0.96 Interpretation of opening with O_WRONLY or O_RDWR:
	      open only for ioctl operation, e.g., for operation of
	      tray etc.
 4 apr 1996:  0.97 First implementation of layer between VFS and cdrom
              driver, a generic interface. Much of the functionality
	      of cm206_open() and cm206_ioctl() is transferred to a
	      new file cdrom.c and its header ucdrom.h. 

	      Upgrade to Linux kernel 1.3.78. 

 11 apr 1996  0.98 Upgrade to Linux kernel 1.3.85
              More code moved to cdrom.c
 
 	      0.99 Some more small changes to decrease number
 	      of oopses at module load; 
 
 27 jul 1996  0.100 Many hours of debugging, kernel change from 1.2.13
	      to 2.0.7 seems to have introduced some weird behavior
	      in (interruptible_)sleep_on(&cd->data): the process
	      seems to be woken without any explicit wake_up in my own
	      code. Patch to try 100x in case such untriggered wake_up's 
	      occur. 

 28 jul 1996  0.101 Rewriting of the code that receives the command echo,
	      using a fifo to store echoed bytes. 

 	      Branch from 0.99:
 
 	      0.99.1.0 Update to kernel release 2.0.10 dev_t -> kdev_t
 	      (emoenke) various typos found by others.  extra
 	      module-load oops protection.
 
 	      0.99.1.1 Initialization constant cdrom_dops.speed
 	      changed from float (2.0) to int (2); Cli()-sti() pair
 	      around cm260_reset() in module initialization code.
 
 	      0.99.1.2 Changes literally as proposed by Scott Snyder
 	      <snyder@d0sgif.fnal.gov> for the 2.1 kernel line, which
 	      have to do mainly with the poor minor support i had. The
 	      major new concept is to change a cdrom driver's
 	      operations struct from the capabilities struct. This
 	      reflects the fact that there is one major for a driver,
 	      whilst there can be many minors whith completely
 	      different capabilities.

	      0.99.1.3 More changes for operations/info separation.

	      0.99.1.4 Added speed selection (someone had to do this
	      first).

  23 jan 1997 0.99.1.5 MODULE_PARMS call added.

  23 jan 1997 0.100.1.2--0.100.1.5 following similar lines as 
  	      0.99.1.1--0.99.1.5. I get too many complaints about the
	      drive making read errors. What't wrong with the 2.0+
	      kernel line? Why get i (and othe cm206 owners) weird
	      results? Why were things good in the good old 1.1--1.2 
	      era? Why don't i throw away the drive?

 2 feb 1997   0.102 Added `volatile' to values in cm206_struct. Seems to 
 	      reduce many of the problems. Rewrote polling routines
	      to use fixed delays between polls. 
	      0.103 Changed printk behavior. 
	      0.104 Added a 0.100 -> 0.100.1.1 change

11 feb 1997   0.105 Allow auto_probe during module load, disable
              with module option "auto_probe=0". Moved some debugging
	      statements to lower priority. Implemented select_speed()
	      function. 

13 feb 1997   1.0 Final version for 2.0 kernel line. 

	      All following changes will be for the 2.1 kernel line. 

15 feb 1997   1.1 Keep up with kernel 2.1.26, merge in changes from 
              cdrom.c 0.100.1.1--1.0. Add some more MODULE_PARMS. 

14 sep 1997   1.2 Upgrade to Linux 2.1.55.  Added blksize_size[], patch
              sent by James Bottomley <James.Bottomley@columbiasc.ncr.com>.

21 dec 1997   1.4 Upgrade to Linux 2.1.72.  

24 jan 1998   Removed the cm206_disc_status() function, as it was now dead
              code.  The Uniform CDROM driver now provides this functionality.
	      
9 Nov. 1999   Make kernel-parameter implementation work with 2.3.x 
	      Removed init_module & cleanup_module in favor of 
	      module_init & module_exit.
	      Torben Mathiasen <tmm@image.dk>
 * 
 * Parts of the code are based upon lmscd.c written by Kai Petzke,
 * sbpcd.c written by Eberhard Moenkeberg, and mcd.c by Martin
 * Harriss, but any off-the-shelf dynamic programming algorithm won't
 * be able to find them.
 *
 * The cm206 drive interface and the cm260 adapter card seem to be 
 * sufficiently different from their cm205/cm250 counterparts
 * in order to write a complete new driver.
 * 
 * I call all routines connected to the Linux kernel something
 * with `cm206' in it, as this stuff is too series-dependent. 
 * 
 * Currently, my limited knowledge is based on:
 * - The Linux Kernel Hacker's guide, v. 0.5, by Michael K. Johnson
 * - Linux Kernel Programmierung, by Michael Beck and others
 * - Philips/LMS cm206 and cm226 product specification
 * - Philips/LMS cm260 product specification
 *
 * David van Leeuwen, david@tm.tno.nl.  */
#define REVISION "$Revision: 1.5 $"

#include <linux/module.h>	

#include <linux/errno.h>	/* These include what we really need */
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/cdrom.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/malloc.h>
#include <linux/init.h>

/* #include <linux/ucdrom.h> */

#include <asm/io.h>

#define MAJOR_NR CM206_CDROM_MAJOR
#include <linux/blk.h>

#undef DEBUG
#define STATISTICS		/* record times and frequencies of events */
#define AUTO_PROBE_MODULE
#define USE_INSW

#include "cm206.h"

/* This variable defines whether or not to probe for adapter base port 
   address and interrupt request. It can be overridden by the boot 
   parameter `auto'.
*/
static int auto_probe=1;	/* Yes, why not? */

static int cm206_base = CM206_BASE;
static int cm206_irq = CM206_IRQ; 
static int cm206[2] = {0,0};	/* for compatible `insmod' parameter passing */

MODULE_PARM(cm206_base, "i");	/* base */
MODULE_PARM(cm206_irq, "i");	/* irq */
MODULE_PARM(cm206, "1-2i");	/* base,irq or irq,base */
MODULE_PARM(auto_probe, "i");	/* auto probe base and irq */

#define POLLOOP 100		/* milliseconds */
#define READ_AHEAD 1		/* defines private buffer, waste! */
#define BACK_AHEAD 1		/* defines adapter-read ahead */
#define DATA_TIMEOUT (3*HZ)	/* measured in jiffies (10 ms) */
#define UART_TIMEOUT (5*HZ/100)
#define DSB_TIMEOUT (7*HZ)	/* time for the slowest command to finish */
#define UR_SIZE 4		/* uart receive buffer fifo size */

#define LINUX_BLOCK_SIZE 512	/* WHERE is this defined? */
#define RAW_SECTOR_SIZE 2352	/* ok, is also defined in cdrom.h */
#define ISO_SECTOR_SIZE 2048
#define BLOCKS_ISO (ISO_SECTOR_SIZE/LINUX_BLOCK_SIZE) /* 4 */
#define CD_SYNC_HEAD 16		/* CD_SYNC + CD_HEAD */

#ifdef STATISTICS		/* keep track of errors in counters */
#define stats(i) { ++cd->stats[st_ ## i]; \
		     cd->last_stat[st_ ## i] = cd->stat_counter++; \
		 }
#else
#define stats(i) (void) 0;
#endif

#define Debug(a) {printk (KERN_DEBUG); printk a;}
#ifdef DEBUG
#define debug(a) Debug(a)
#else
#define debug(a) (void) 0;
#endif

typedef unsigned char uch;	/* 8-bits */
typedef unsigned short ush;	/* 16-bits */

struct toc_struct{		/* private copy of Table of Contents */
  uch track, fsm[3], q0;
};

static int cm206_blocksizes[1] = { 2048 };

struct cm206_struct {
  volatile ush intr_ds;		/* data status read on last interrupt */
  volatile ush intr_ls;		/* uart line status read on last interrupt*/
  volatile uch ur[UR_SIZE];	/* uart receive buffer fifo */
  volatile uch ur_w, ur_r;	/* write/read buffer index */
  volatile uch dsb, cc;	 /* drive status byte and condition (error) code */
  int command;			/* command to be written to the uart */
  int openfiles;
  ush sector[READ_AHEAD*RAW_SECTOR_SIZE/2]; /* buffered cd-sector */
  int sector_first, sector_last; /* range of these sectors */
  wait_queue_head_t uart;	/* wait queues for interrupt */
  wait_queue_head_t data;
  struct timer_list timer;	/* time-out */
  char timed_out;
  signed char max_sectors;	/* number of sectors that fit in adapter mem */
  char wait_back;		/* we're waiting for a background-read */
  char background;		/* is a read going on in the background? */
  int adapter_first;		/* if so, that's the starting sector */
  int adapter_last;
  char fifo_overflowed;
  uch disc_status[7];		/* result of get_disc_status command */
#ifdef STATISTICS
  int stats[NR_STATS];
  int last_stat[NR_STATS];	/* `time' at which stat was stat */
  int stat_counter;
#endif  
  struct toc_struct toc[101];	/* The whole table of contents + lead-out */
  uch q[10];			/* Last read q-channel info */
  uch audio_status[5];		/* last read position on pause */
  uch media_changed;		/* record if media changed */
};

#define DISC_STATUS cd->disc_status[0]
#define FIRST_TRACK cd->disc_status[1]
#define LAST_TRACK cd->disc_status[2]
#define PAUSED cd->audio_status[0] /* misuse this memory byte! */
#define PLAY_TO cd->toc[0]	/* toc[0] records end-time in play */

static struct cm206_struct * cd; /* the main memory structure */

/* First, we define some polling functions. These are actually
   only being used in the initialization. */

void send_command_polled(int command)
{
  int loop=POLLOOP;
  while (!(inw(r_line_status) & ls_transmitter_buffer_empty) && loop>0) {
    mdelay(1);		/* one millisec delay */
    --loop;
  }
  outw(command, r_uart_transmit);
}

uch receive_echo_polled(void)
{
  int loop=POLLOOP;
  while (!(inw(r_line_status) & ls_receive_buffer_full) && loop>0) {
    mdelay(1);
    --loop;
  }
  return ((uch) inw(r_uart_receive));
}

uch send_receive_polled(int command)
{
  send_command_polled(command);
  return receive_echo_polled();
}

inline void clear_ur(void) {
  if (cd->ur_r != cd->ur_w) {
    debug(("Deleting bytes from fifo:"));
    for(;cd->ur_r != cd->ur_w; cd->ur_r++, cd->ur_r %= UR_SIZE)
      debug((" 0x%x", cd->ur[cd->ur_r]));
    debug(("\n"));
  }
}

/* The interrupt handler. When the cm260 generates an interrupt, very
   much care has to be taken in reading out the registers in the right
   order; in case of a receive_buffer_full interrupt, first the
   uart_receive must be read, and then the line status again to
   de-assert the interrupt line. It took me a couple of hours to find
   this out:-( 

   The function reset_cm206 appears to cause an interrupt, because
   pulling up the INIT line clears both the uart-write-buffer /and/
   the uart-write-buffer-empty mask. We call this a `lost interrupt,'
   as there seems so reason for this to happen.
*/

static void cm206_interrupt(int sig, void *dev_id, struct pt_regs * regs) 
/* you rang? */
{
  volatile ush fool;
  cd->intr_ds = inw(r_data_status); /* resets data_ready, data_error,
				       crc_error, sync_error, toc_ready 
				       interrupts */
  cd->intr_ls = inw(r_line_status); /* resets overrun bit */
  debug(("Intr, 0x%x 0x%x, %d\n", cd->intr_ds, cd->intr_ls, cd->background));
  if (cd->intr_ls & ls_attention) stats(attention);
  /* receive buffer full? */
  if (cd->intr_ls & ls_receive_buffer_full) {	
    cd->ur[cd->ur_w] = inb(r_uart_receive); /* get order right! */
    cd->intr_ls = inw(r_line_status); /* resets rbf interrupt */
    debug(("receiving #%d: 0x%x\n", cd->ur_w, cd->ur[cd->ur_w]));
    cd->ur_w++; cd->ur_w %= UR_SIZE;
    if (cd->ur_w == cd->ur_r) debug(("cd->ur overflow!\n"));
    if (waitqueue_active(&cd->uart) && cd->background < 2) { 
      del_timer(&cd->timer);
      wake_up_interruptible(&cd->uart);
    }
  }
  /* data ready in fifo? */
  else if (cd->intr_ds & ds_data_ready) { 
    if (cd->background) ++cd->adapter_last;
    if (waitqueue_active(&cd->data) && (cd->wait_back || !cd->background)) {
      del_timer(&cd->timer);
      wake_up_interruptible(&cd->data);
    }
    stats(data_ready);
  }
  /* ready to issue a write command? */
  else if (cd->command && cd->intr_ls & ls_transmitter_buffer_empty) {
    outw(dc_normal | (inw(r_data_status) & 0x7f), r_data_control);
    outw(cd->command, r_uart_transmit);
    cd->command=0;
    if (!cd->background) wake_up_interruptible(&cd->uart);
  }
  /* now treat errors (at least, identify them for debugging) */
  else if (cd->intr_ds & ds_fifo_overflow) {
    debug(("Fifo overflow at sectors 0x%x\n", cd->sector_first));
    fool = inw(r_fifo_output_buffer);	/* de-assert the interrupt */
    cd->fifo_overflowed=1;	/* signal one word less should be read */
    stats(fifo_overflow);
  }
  else if (cd->intr_ds & ds_data_error) {
    debug(("Data error at sector 0x%x\n", cd->sector_first));
    stats(data_error);
  }
  else if (cd->intr_ds & ds_crc_error) {
    debug(("CRC error at sector 0x%x\n", cd->sector_first));
    stats(crc_error);
  }
  else if (cd->intr_ds & ds_sync_error) {
    debug(("Sync at sector 0x%x\n", cd->sector_first));
    stats(sync_error);
  }
  else if (cd->intr_ds & ds_toc_ready) {
    /* do something appropriate */
  }
  /* couldn't see why this interrupt, maybe due to init */
  else {			
    outw(dc_normal | READ_AHEAD, r_data_control);
    stats(lost_intr);
  }
  if (cd->background && (cd->adapter_last-cd->adapter_first == cd->max_sectors
			 || cd->fifo_overflowed))
    mark_bh(CM206_BH);	/* issue a stop read command */
  stats(interrupt);
}

/* we have put the address of the wait queue in who */
void cm206_timeout(unsigned long who)
{
  cd->timed_out = 1;
  debug(("Timing out\n"));
  wake_up_interruptible((wait_queue_head_t *)who);
}

/* This function returns 1 if a timeout occurred, 0 if an interrupt
   happened */
int sleep_or_timeout(wait_queue_head_t *wait, int timeout)
{
  cd->timed_out=0;
  cd->timer.data=(unsigned long) wait;
  cd->timer.expires = jiffies + timeout;
  add_timer(&cd->timer);
  debug(("going to sleep\n"));
  interruptible_sleep_on(wait);
  del_timer(&cd->timer);
  if (cd->timed_out) {
    cd->timed_out = 0;
    return 1;
  }
  else return 0;
}

void cm206_delay(int nr_jiffies) 
{
  DECLARE_WAIT_QUEUE_HEAD(wait);
  sleep_or_timeout(&wait, nr_jiffies);
}

void send_command(int command)
{
  debug(("Sending 0x%x\n", command));
  if (!(inw(r_line_status) & ls_transmitter_buffer_empty)) {
    cd->command = command;
    cli();			/* don't interrupt before sleep */
    outw(dc_mask_sync_error | dc_no_stop_on_error | 
	 (inw(r_data_status) & 0x7f), r_data_control);
    /* interrupt routine sends command */
    if (sleep_or_timeout(&cd->uart, UART_TIMEOUT)) {
      debug(("Time out on write-buffer\n"));
      stats(write_timeout);
      outw(command, r_uart_transmit);
    }
    debug(("Write commmand delayed\n"));
  }
  else outw(command, r_uart_transmit);
}

uch receive_byte(int timeout)
{
  uch ret;
  cli();
  debug(("cli\n"));
  ret = cd->ur[cd->ur_r];
  if (cd->ur_r != cd->ur_w) {
    sti();
    debug(("returning #%d: 0x%x\n", cd->ur_r, cd->ur[cd->ur_r]));
    cd->ur_r++; cd->ur_r %= UR_SIZE;
    return ret;
  } 
  else if (sleep_or_timeout(&cd->uart, timeout)) { /* does sti() */
    debug(("Time out on receive-buffer\n"));
#ifdef STATISTICS
    if (timeout==UART_TIMEOUT) stats(receive_timeout) /* no `;'! */
    else stats(dsb_timeout);
#endif
    return 0xda;
  }
  ret = cd->ur[cd->ur_r];  
  debug(("slept; returning #%d: 0x%x\n", cd->ur_r, cd->ur[cd->ur_r]));
  cd->ur_r++; cd->ur_r %= UR_SIZE;
  return ret;
}

inline uch receive_echo(void)
{
  return receive_byte(UART_TIMEOUT);
}

inline uch send_receive(int command)
{
  send_command(command);
  return receive_echo();
}

inline uch wait_dsb(void)
{
  return receive_byte(DSB_TIMEOUT);
}

int type_0_command(int command, int expect_dsb)
{
  int e;
  clear_ur();
  if (command != (e=send_receive(command))) {
    debug(("command 0x%x echoed as 0x%x\n", command, e));
    stats(echo);
    return -1;
  }
  if (expect_dsb) {
    cd->dsb = wait_dsb();	/* wait for command to finish */
  }
  return 0;
}

int type_1_command(int command, int bytes, uch * status) /* returns info */
{
  int i;
  if (type_0_command(command,0)) return -1;
  for(i=0; i<bytes; i++) 
    status[i] = send_receive(c_gimme);
  return 0;
}  

/* This function resets the adapter card. We'd better not do this too
 * often, because it tends to generate `lost interrupts.' */
void reset_cm260(void)
{
  outw(dc_normal | dc_initialize | READ_AHEAD, r_data_control);
  udelay(10);			/* 3.3 mu sec minimum */
  outw(dc_normal | READ_AHEAD, r_data_control);
}

/* fsm: frame-sec-min from linear address; one of many */
void fsm(int lba, uch * fsm) 
{
  fsm[0] = lba % 75;
  lba /= 75; lba += 2;
  fsm[1] = lba % 60; fsm[2] = lba / 60;
}

inline int fsm2lba(uch * fsm) 
{
  return fsm[0] + 75*(fsm[1]-2 + 60*fsm[2]);
}

inline int f_s_m2lba(uch f, uch s, uch m)
{
  return f + 75*(s-2 + 60*m);
}

int start_read(int start) 
{
  uch read_sector[4] = {c_read_data, };
  int i, e;

  fsm(start, &read_sector[1]);
  clear_ur();
  for (i=0; i<4; i++) 
    if (read_sector[i] != (e=send_receive(read_sector[i]))) {
      debug(("read_sector: %x echoes %x\n", read_sector[i], e));
      stats(echo);
      if (e==0xff) {		/* this seems to happen often */
	e = receive_echo();
	debug(("Second try %x\n", e));
	if (e!=read_sector[i]) return -1;
      }
    }
  return 0;
}

int stop_read(void)
{
  int e;
  type_0_command(c_stop,0);
  if((e=receive_echo()) != 0xff) {
    debug(("c_stop didn't send 0xff, but 0x%x\n", e));
    stats(stop_0xff);
    return -1;
  }
  return 0;
}  

/* This function starts to read sectors in adapter memory, the
   interrupt routine should stop the read. In fact, the bottom_half
   routine takes care of this. Set a flag `background' in the cd
   struct to indicate the process. */

int read_background(int start, int reading)
{
  if (cd->background) return -1; /* can't do twice */
  outw(dc_normal | BACK_AHEAD, r_data_control);
  if (!reading && start_read(start)) return -2;
  cd->adapter_first = cd->adapter_last = start; 
  cd->background = 1;		/* flag a read is going on */
  return 0;
}

#ifdef USE_INSW
#define transport_data insw
#else
/* this routine implements insw(,,). There was a time i had the
   impression that there would be any difference in error-behaviour. */
void transport_data(int port, ush * dest, int count) 
{
  int i;
  ush * d;
  for (i=0, d=dest; i<count; i++, d++) 
    *d = inw(port);
}
#endif


#define MAX_TRIES 100
int read_sector(int start)
{
  int tries=0;
  if (cd->background) {
    cd->background=0;
    cd->adapter_last = -1;	/* invalidate adapter memory */
    stop_read();
  }
  cd->fifo_overflowed=0;
  reset_cm260();		/* empty fifo etc. */
  if (start_read(start)) return -1;
  do {
    if (sleep_or_timeout(&cd->data, DATA_TIMEOUT)) {
      debug(("Read timed out sector 0x%x\n", start));
      stats(read_timeout);
      stop_read();
      return -3;		
    } 
    tries++;
  } while (cd->intr_ds & ds_fifo_empty && tries < MAX_TRIES);
  if (tries>1) debug(("Took me some tries\n"))
  else if (tries == MAX_TRIES) 
    debug(("MAX_TRIES tries for read sector\n"));
  transport_data(r_fifo_output_buffer, cd->sector, 
		 READ_AHEAD*RAW_SECTOR_SIZE/2);
  if (read_background(start+READ_AHEAD,1)) stats(read_background);
  cd->sector_first = start; cd->sector_last = start+READ_AHEAD;
  stats(read_restarted);
  return 0;
}

/* The function of bottom-half is to send a stop command to the drive
   This isn't easy because the routine is not `owned' by any process;
   we can't go to sleep! The variable cd->background gives the status:
   0 no read pending
   1 a read is pending
   2 c_stop waits for write_buffer_empty
   3 c_stop waits for receive_buffer_full: echo
   4 c_stop waits for receive_buffer_full: 0xff
*/

void cm206_bh(void)
{
  debug(("bh: %d\n", cd->background));
  switch (cd->background) {
  case 1:
    stats(bh);
    if (!(cd->intr_ls & ls_transmitter_buffer_empty)) {
      cd->command = c_stop;
      outw(dc_mask_sync_error | dc_no_stop_on_error | 
	   (inw(r_data_status) & 0x7f), r_data_control);
      cd->background=2;
      break;			/* we'd better not time-out here! */
    }
    else outw(c_stop, r_uart_transmit);
    /* fall into case 2: */
  case 2:			
    /* the write has been satisfied by interrupt routine */
    cd->background=3;
    break;
  case 3:
    if (cd->ur_r != cd->ur_w) {
      if (cd->ur[cd->ur_r] != c_stop) {
	debug(("cm206_bh: c_stop echoed 0x%x\n", cd->ur[cd->ur_r]));
	stats(echo);
      }
      cd->ur_r++; cd->ur_r %= UR_SIZE;
    }
    cd->background++;
    break;
  case 4:
    if (cd->ur_r != cd->ur_w) {
      if (cd->ur[cd->ur_r] != 0xff) {
	debug(("cm206_bh: c_stop reacted with 0x%x\n", cd->ur[cd->ur_r]));
	stats(stop_0xff);
      }
      cd->ur_r++; cd->ur_r %= UR_SIZE;
    }
    cd->background=0;
  }
}

/* This command clears the dsb_possible_media_change flag, so we must 
 * retain it.
 */
void get_drive_status(void)
{
  uch status[2];
  type_1_command(c_drive_status, 2, status); /* this might be done faster */
  cd->dsb=status[0];
  cd->cc=status[1];
  cd->media_changed |= 
    !!(cd->dsb & (dsb_possible_media_change | 
		  dsb_drive_not_ready | dsb_tray_not_closed));
}

void get_disc_status(void)
{
  if (type_1_command(c_disc_status, 7, cd->disc_status)) {
    debug(("get_disc_status: error\n"));
  }
}

/* The new open. The real opening strategy is defined in cdrom.c. */

static int cm206_open(struct cdrom_device_info * cdi, int purpose) 
{
  MOD_INC_USE_COUNT;
  if (!cd->openfiles) {		/* reset only first time */
    cd->background=0;
    reset_cm260();
    cd->adapter_last = -1;	/* invalidate adapter memory */
    cd->sector_last = -1;
  }
  ++cd->openfiles;
  stats(open);
  return 0;
}

static void cm206_release(struct cdrom_device_info * cdi)
{
  if (cd->openfiles==1) {
    if (cd->background) {
      cd->background=0;
      stop_read();
    }
    cd->sector_last = -1;	/* Make our internal buffer invalid */
    FIRST_TRACK = 0;		/* No valid disc status */
  }
  --cd->openfiles;
  MOD_DEC_USE_COUNT;
}

/* Empty buffer empties $sectors$ sectors of the adapter card buffer,
 * and then reads a sector in kernel memory.  */
void empty_buffer(int sectors) 
{
  while (sectors>=0) {
    transport_data(r_fifo_output_buffer, cd->sector + cd->fifo_overflowed, 
	 RAW_SECTOR_SIZE/2 - cd->fifo_overflowed);
    --sectors;
    ++cd->adapter_first;	/* update the current adapter sector */
    cd->fifo_overflowed=0;	/* reset overflow bit */
    stats(sector_transferred);
  } 
  cd->sector_first=cd->adapter_first-1;
  cd->sector_last=cd->adapter_first; /* update the buffer sector */
}

/* try_adapter. This function determines if the requested sector is
   in adapter memory, or will appear there soon. Returns 0 upon
   success */
int try_adapter(int sector)
{
  if (cd->adapter_first <= sector && sector < cd->adapter_last) { 
    /* sector is in adapter memory */
    empty_buffer(sector - cd->adapter_first);
    return 0;
  }
  else if (cd->background==1 && cd->adapter_first <= sector
	   && sector < cd->adapter_first+cd->max_sectors) {
    /* a read is going on, we can wait for it */
    cd->wait_back=1;
    while (sector >= cd->adapter_last) {
      if (sleep_or_timeout(&cd->data, DATA_TIMEOUT)) {
	debug(("Timed out during background wait: %d %d %d %d\n", sector, 
	       cd->adapter_last, cd->adapter_first, cd->background));
	stats(back_read_timeout);
	cd->wait_back=0;
	return -1;
      }
    }
    cd->wait_back=0;
    empty_buffer(sector - cd->adapter_first);
    return 0;
  }
  else return -2;
}

/* This is not a very smart implementation. We could optimize for 
   consecutive block numbers. I'm not convinced this would really
   bring down the processor load. */
static void do_cm206_request(request_queue_t * q)
{
  long int i, cd_sec_no;
  int quarter, error; 
  uch * source, * dest;
  
  while(1) {	 /* repeat until all requests have been satisfied */
    INIT_REQUEST;
    if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE)
      return;
    if (CURRENT->cmd != READ) {
      debug(("Non-read command %d on cdrom\n", CURRENT->cmd));
      end_request(0);
      continue;
    }
    spin_unlock_irq(&io_request_lock);
    error=0;
    for (i=0; i<CURRENT->nr_sectors; i++) {
      int e1, e2;
      cd_sec_no = (CURRENT->sector+i)/BLOCKS_ISO; /* 4 times 512 bytes */
      quarter = (CURRENT->sector+i) % BLOCKS_ISO; 
      dest = CURRENT->buffer + i*LINUX_BLOCK_SIZE;
      /* is already in buffer memory? */
      if (cd->sector_first <= cd_sec_no && cd_sec_no < cd->sector_last) {
	source = ((uch *) cd->sector) + 16 + quarter*LINUX_BLOCK_SIZE 
	  + (cd_sec_no-cd->sector_first)*RAW_SECTOR_SIZE;
 	memcpy(dest, source, LINUX_BLOCK_SIZE); 
      }
      else if (!(e1=try_adapter(cd_sec_no)) || 
	       !(e2=read_sector(cd_sec_no))) {
	source =  ((uch *) cd->sector)+16+quarter*LINUX_BLOCK_SIZE;
	memcpy(dest, source, LINUX_BLOCK_SIZE); 
      }
      else {
	error=1;
	debug(("cm206_request: %d %d\n", e1, e2));
      }
    }
    spin_lock_irq(&io_request_lock);
    end_request(!error);
  }
}

/* Audio support. I've tried very hard, but the cm206 drive doesn't 
   seem to have a get_toc (table-of-contents) function, while i'm
   pretty sure it must read the toc upon disc insertion. Therefore
   this function has been implemented through a binary search 
   strategy. All track starts that happen to be found are stored in
   cd->toc[], for future use. 

   I've spent a whole day on a bug that only shows under Workman---
   I don't get it. Tried everything, nothing works. If workman asks
   for track# 0xaa, it'll get the wrong time back. Any other program
   receives the correct value. I'm stymied.
*/

/* seek seeks to address lba. It does wait to arrive there. */
void seek(int lba)
{
  int i;
  uch seek_command[4]={c_seek, };
  
  fsm(lba, &seek_command[1]);
  for (i=0; i<4; i++) type_0_command(seek_command[i], 0);
  cd->dsb = wait_dsb();
}

uch bcdbin(unsigned char bcd)	/* stolen from mcd.c! */
{
  return (bcd >> 4)*10 + (bcd & 0xf);
} 

inline uch normalize_track(uch track) 
{
  if (track<1) return 1;
  if (track>LAST_TRACK) return LAST_TRACK+1;
  return track;
}

/* This function does a binary search for track start. It records all
 * tracks seen in the process. Input $track$ must be between 1 and
 * #-of-tracks+1.  Note that the start of the disc must be in toc[1].fsm. 
 */
int get_toc_lba(uch track)
{
  int max=74*60*75-150, min=fsm2lba(cd->toc[1].fsm);
  int i, lba, l, old_lba=0;
  uch * q = cd->q;
  uch ct;			/* current track */
  int binary=0;
  const int skip = 3*60*75;		/* 3 minutes */

  for (i=track; i>0; i--) if (cd->toc[i].track) {
    min = fsm2lba(cd->toc[i].fsm);
    break;
  }
  lba = min + skip;
  do {
    seek(lba); 
    type_1_command(c_read_current_q, 10, q);
    ct = normalize_track(q[1]);
    if (!cd->toc[ct].track) {
      l = q[9]-bcdbin(q[5]) + 75*(q[8]-bcdbin(q[4])-2 + 
				  60*(q[7]-bcdbin(q[3])));
      cd->toc[ct].track=q[1];	/* lead out still 0xaa */
      fsm(l, cd->toc[ct].fsm);
      cd->toc[ct].q0 = q[0];	/* contains adr and ctrl info */
      if (ct==track) return l;
    }
    old_lba=lba;
    if (binary) {
      if (ct < track) min = lba; else max = lba;
      lba = (min+max)/2; 
    } else {
      if(ct < track) lba += skip;
      else {
	binary=1;
	max = lba; min = lba - skip;
	lba = (min+max)/2;
      }
    }
  } while (lba!=old_lba);
  return lba;
}

void update_toc_entry(uch track) 
{
  track = normalize_track(track);
  if (!cd->toc[track].track) get_toc_lba(track);
}

/* return 0 upon success */
int read_toc_header(struct cdrom_tochdr * hp)
{
  if (!FIRST_TRACK) get_disc_status();
  if (hp) { 
    int i;
    hp->cdth_trk0 = FIRST_TRACK;
    hp->cdth_trk1 = LAST_TRACK; 
				/* fill in first track position */
    for (i=0; i<3; i++) cd->toc[1].fsm[i] = cd->disc_status[3+i];
    update_toc_entry(LAST_TRACK+1);		/* find most entries */
    return 0;
  }
  return -1;
}  

void play_from_to_msf(struct cdrom_msf* msfp)
{
  uch play_command[] = {c_play, 
	   msfp->cdmsf_frame0, msfp->cdmsf_sec0, msfp->cdmsf_min0,
	   msfp->cdmsf_frame1, msfp->cdmsf_sec1, msfp->cdmsf_min1, 2, 2};
  int i;
  for (i=0; i<9; i++) type_0_command(play_command[i], 0);
  for (i=0; i<3; i++) 
    PLAY_TO.fsm[i] = play_command[i+4];
  PLAY_TO.track = 0;		/* say no track end */
  cd->dsb = wait_dsb();
}  

void play_from_to_track(int from, int to)
{
  uch play_command[8] = {c_play, };
  int i;

  if (from==0) {		/* continue paused play */
    for (i=0; i<3; i++) { 
      play_command[i+1] = cd->audio_status[i+2];
      play_command[i+4] = PLAY_TO.fsm[i];
    }
  } else {
    update_toc_entry(from); update_toc_entry(to+1);
    for (i=0; i<3; i++) {
      play_command[i+1] = cd->toc[from].fsm[i];
      PLAY_TO.fsm[i] = play_command[i+4] = cd->toc[to+1].fsm[i];
    }
    PLAY_TO.track = to; 
  }
  for (i=0; i<7; i++) type_0_command(play_command[i],0);
  for (i=0; i<2; i++) type_0_command(0x2, 0); /* volume */
  cd->dsb = wait_dsb();
}

int get_current_q(struct cdrom_subchnl * qp)
{
  int i;
  uch * q = cd->q;
  if (type_1_command(c_read_current_q, 10, q)) return 0;
/*  q[0] = bcdbin(q[0]); Don't think so! */
  for (i=2; i<6; i++) q[i]=bcdbin(q[i]); 
  qp->cdsc_adr = q[0] & 0xf; qp->cdsc_ctrl = q[0] >> 4;	/* from mcd.c */
  qp->cdsc_trk = q[1];  qp->cdsc_ind = q[2];
  if (qp->cdsc_format == CDROM_MSF) {
    qp->cdsc_reladdr.msf.minute = q[3];
    qp->cdsc_reladdr.msf.second = q[4];
    qp->cdsc_reladdr.msf.frame = q[5];
    qp->cdsc_absaddr.msf.minute = q[7];
    qp->cdsc_absaddr.msf.second = q[8];
    qp->cdsc_absaddr.msf.frame = q[9];
  } else {
    qp->cdsc_reladdr.lba = f_s_m2lba(q[5], q[4], q[3]);
    qp->cdsc_absaddr.lba = f_s_m2lba(q[9], q[8], q[7]);
  }
  get_drive_status();
  if (cd->dsb & dsb_play_in_progress) 
    qp->cdsc_audiostatus = CDROM_AUDIO_PLAY ;
  else if (PAUSED) 
    qp->cdsc_audiostatus = CDROM_AUDIO_PAUSED;
  else qp->cdsc_audiostatus = CDROM_AUDIO_NO_STATUS;
  return 0;
}

void invalidate_toc(void)
{
  memset(cd->toc, 0, sizeof(cd->toc));
  memset(cd->disc_status, 0, sizeof(cd->disc_status));
}

/* cdrom.c guarantees that cdte_format == CDROM_MSF */
void get_toc_entry(struct cdrom_tocentry * ep)
{
  uch track = normalize_track(ep->cdte_track);
  update_toc_entry(track);
  ep->cdte_addr.msf.frame = cd->toc[track].fsm[0];
  ep->cdte_addr.msf.second = cd->toc[track].fsm[1];
  ep->cdte_addr.msf.minute = cd->toc[track].fsm[2];
  ep->cdte_adr = cd->toc[track].q0 & 0xf; 
  ep->cdte_ctrl = cd->toc[track].q0 >> 4;
  ep->cdte_datamode=0;
}

/* Audio ioctl.  Ioctl commands connected to audio are in such an
 * idiosyncratic i/o format, that we leave these untouched. Return 0
 * upon success. Memory checking has been done by cdrom_ioctl(), the
 * calling function, as well as LBA/MSF sanitization.
*/
int cm206_audio_ioctl(struct cdrom_device_info * cdi, unsigned int cmd, 
		      void * arg)  
{
  switch (cmd) {
  case CDROMREADTOCHDR: 
    return read_toc_header((struct cdrom_tochdr *) arg);
  case CDROMREADTOCENTRY: 	
    get_toc_entry((struct cdrom_tocentry *) arg);
    return 0;
  case CDROMPLAYMSF: 
    play_from_to_msf((struct cdrom_msf *) arg);
    return 0;
  case CDROMPLAYTRKIND:		/* admittedly, not particularly beautiful */
    play_from_to_track(((struct cdrom_ti *)arg)->cdti_trk0, 
		       ((struct cdrom_ti *)arg)->cdti_trk1);
    return 0;
  case CDROMSTOP: 
    PAUSED=0;
    if (cd->dsb & dsb_play_in_progress) return type_0_command(c_stop, 1);
    else return 0;
  case CDROMPAUSE: 
    get_drive_status();
    if (cd->dsb & dsb_play_in_progress) {
      type_0_command(c_stop, 1);
      type_1_command(c_audio_status, 5, cd->audio_status);
      PAUSED=1;	/* say we're paused */
    }
    return 0;
  case CDROMRESUME:
    if (PAUSED) play_from_to_track(0,0);
    PAUSED=0;
    return 0;
  case CDROMSTART:
  case CDROMVOLCTRL:
    return 0;
  case CDROMSUBCHNL: 
    return get_current_q((struct cdrom_subchnl *)arg);
  default:
    return -EINVAL;
  }
}

/* Ioctl. These ioctls are specific to the cm206 driver. I have made
   some driver statistics accessible through ioctl calls.
 */

static int cm206_ioctl(struct cdrom_device_info * cdi, unsigned int cmd, 
		       unsigned long arg)
{
  switch (cmd) {
#ifdef STATISTICS
  case CM206CTL_GET_STAT:
    if (arg >= NR_STATS) return -EINVAL;
    else return cd->stats[arg];
  case CM206CTL_GET_LAST_STAT:
    if (arg >= NR_STATS) return -EINVAL;
    else return cd->last_stat[arg];
#endif    
  default:
    debug(("Unknown ioctl call 0x%x\n", cmd));
    return -EINVAL;
  }
}     

int cm206_media_changed(struct cdrom_device_info * cdi, int disc_nr) 
{
  if (cd != NULL) {
    int r;
    get_drive_status();		/* ensure cd->media_changed OK */
    r = cd->media_changed;
    cd->media_changed = 0;	/* clear bit */
    return r;
  }
  else return -EIO;
}

/* The new generic cdrom support. Routines should be concise, most of
   the logic should be in cdrom.c */

/* returns number of times device is in use */
int cm206_open_files(struct cdrom_device_info * cdi)	
{
  if (cd) return cd->openfiles;
  return -1;
}

/* controls tray movement */
int cm206_tray_move(struct cdrom_device_info * cdi, int position) 
{
  if (position) {		/* 1: eject */
    type_0_command(c_open_tray,1);
    invalidate_toc();
  } 
  else type_0_command(c_close_tray, 1);	/* 0: close */
  return 0;
}

/* gives current state of the drive */
int cm206_drive_status(struct cdrom_device_info * cdi, int slot_nr)
{
  get_drive_status();
  if (cd->dsb & dsb_tray_not_closed) return CDS_TRAY_OPEN;
  if (!(cd->dsb & dsb_disc_present)) return CDS_NO_DISC; 
  if (cd->dsb & dsb_drive_not_ready) return CDS_DRIVE_NOT_READY;
  return CDS_DISC_OK;
}
 
/* locks or unlocks door lock==1: lock; return 0 upon success */
int cm206_lock_door(struct cdrom_device_info * cdi, int lock)
{
  uch command = (lock) ? c_lock_tray : c_unlock_tray;
  type_0_command(command, 1);	/* wait and get dsb */
  /* the logic calculates the success, 0 means successful */
  return lock ^ ((cd->dsb & dsb_tray_locked) != 0);
}
  
/* Although a session start should be in LBA format, we return it in 
   MSF format because it is slightly easier, and the new generic ioctl
   will take care of the necessary conversion. */
int cm206_get_last_session(struct cdrom_device_info * cdi, 
			   struct cdrom_multisession * mssp) 
{
  if (!FIRST_TRACK) get_disc_status();
  if (mssp != NULL) {
    if (DISC_STATUS & cds_multi_session) { /* multi-session */
      mssp->addr.msf.frame = cd->disc_status[3];
      mssp->addr.msf.second = cd->disc_status[4];
      mssp->addr.msf.minute = cd->disc_status[5];
      mssp->addr_format = CDROM_MSF;
      mssp->xa_flag = 1;
    } else {
      mssp->xa_flag = 0;
    }
    return 1;
  }
  return 0;
}

int cm206_get_upc(struct cdrom_device_info * cdi, struct cdrom_mcn * mcn)
{
  uch upc[10];
  char * ret = mcn->medium_catalog_number;
  int i;
  
  if (type_1_command(c_read_upc, 10, upc)) return -EIO;
  for (i=0; i<13; i++) {
    int w=i/2+1, r=i%2;
    if (r) ret[i] = 0x30 | (upc[w] & 0x0f);
    else ret[i] = 0x30 | ((upc[w] >> 4) & 0x0f);
  }
  ret[13] = '\0';
  return 0;
} 

int cm206_reset(struct cdrom_device_info * cdi)
{
  stop_read();
  reset_cm260();
  outw(dc_normal | dc_break | READ_AHEAD, r_data_control);
  mdelay(1);			/* 750 musec minimum */
  outw(dc_normal | READ_AHEAD, r_data_control);
  cd->sector_last = -1;		/* flag no data buffered */
  cd->adapter_last = -1;    
  invalidate_toc();
  return 0;
}

int cm206_select_speed(struct cdrom_device_info * cdi, int speed)
{
  int r;
  switch (speed) {
  case 0: 
    r = type_0_command(c_auto_mode, 1);
    break;
  case 1:
    r = type_0_command(c_force_1x, 1);
    break;
  case 2:
    r = type_0_command(c_force_2x, 1);
    break;
  default:
    return -1;
  }
  if (r<0) return r;
  else return 1;
}

static struct cdrom_device_ops cm206_dops = {
	open:			cm206_open,
	release:		cm206_release,
	drive_status:		cm206_drive_status,
	media_changed:		cm206_media_changed,
	tray_move:		cm206_tray_move,
	lock_door:		cm206_lock_door,
	select_speed:		cm206_select_speed,
	get_last_session:	cm206_get_last_session,
	get_mcn:		cm206_get_upc,
	reset:			cm206_reset,
	audio_ioctl:		cm206_audio_ioctl,
	dev_ioctl:		cm206_ioctl,
	capability:		CDC_CLOSE_TRAY | CDC_OPEN_TRAY | CDC_LOCK |
				CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
				CDC_MCN | CDC_PLAY_AUDIO | CDC_SELECT_SPEED |
				CDC_IOCTLS | CDC_DRIVE_STATUS, 
	n_minors:		1,
};


static struct cdrom_device_info cm206_info = {
	ops:		&cm206_dops,
	speed:		2,
	capacity:	1,
	name:		"cm206",
};

/* This routine gets called during initialization if things go wrong,
 * can be used in cleanup_module as well. */
static void cleanup(int level)
{
  switch (level) {
  case 4: 
    if (unregister_cdrom(&cm206_info)) {
      printk("Can't unregister cdrom cm206\n");
      return;
    }
    if (devfs_unregister_blkdev(MAJOR_NR, "cm206")) {
      printk("Can't unregister major cm206\n");
      return;
    }
    blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
  case 3: 
    free_irq(cm206_irq, NULL);
  case 2: 
  case 1: 
    kfree(cd);
    release_region(cm206_base, 16);
  default:
  }
}

/* This function probes for the adapter card. It returns the base
   address if it has found the adapter card. One can specify a base 
   port to probe specifically, or 0 which means span all possible
   bases. 

   Linus says it is too dangerous to use writes for probing, so we
   stick with pure reads for a while. Hope that 8 possible ranges,
   check_region, 15 bits of one port and 6 of another make things
   likely enough to accept the region on the first hit...
 */
int __init probe_base_port(int base)
{
  int b=0x300, e=0x370;		/* this is the range of start addresses */
  volatile int fool, i;

  if (base) b=e=base;
  for (base=b; base<=e; base += 0x10) {
    if (check_region(base, 0x10)) continue;
    for (i=0; i<3; i++) 
      fool = inw(base+2); /* empty possibly uart_receive_buffer */
    if((inw(base+6) & 0xffef) != 0x0001 || /* line_status */
       (inw(base) & 0xad00) != 0) /* data status */
      continue;
    return(base);
  }
  return 0;
}

#if !defined(MODULE) || defined(AUTO_PROBE_MODULE)
/* Probe for irq# nr. If nr==0, probe for all possible irq's. */
int __init probe_irq(int nr){
  int irqs, irq;
  outw(dc_normal | READ_AHEAD, r_data_control);	/* disable irq-generation */
  sti(); 
  irqs = probe_irq_on();
  reset_cm260();		/* causes interrupt */
  udelay(100);			/* wait for it */
  irq = probe_irq_off(irqs);
  outw(dc_normal | READ_AHEAD, r_data_control);	/* services interrupt */
  if (nr && irq!=nr && irq>0) return 0;	/* wrong interrupt happened */
  else return irq;
}
#endif

int __init cm206_init(void)
{
  uch e=0;
  long int size=sizeof(struct cm206_struct);

  printk(KERN_INFO "cm206 cdrom driver " REVISION);
  cm206_base = probe_base_port(auto_probe ? 0 : cm206_base);
  if (!cm206_base) {
    printk(" can't find adapter!\n");
    return -EIO;
  }
  printk(" adapter at 0x%x", cm206_base);
  request_region(cm206_base, 16, "cm206");
  cd = (struct cm206_struct *) kmalloc(size, GFP_KERNEL);
  if (!cd) return -EIO;
  /* Now we have found the adaptor card, try to reset it. As we have
   * found out earlier, this process generates an interrupt as well,
   * so we might just exploit that fact for irq probing! */
#if !defined(MODULE) || defined(AUTO_PROBE_MODULE)
  cm206_irq = probe_irq(auto_probe ? 0 : cm206_irq);	
  if (cm206_irq<=0) {
    printk("can't find IRQ!\n");
    cleanup(1);
    return -EIO;
  }
  else printk(" IRQ %d found\n", cm206_irq);
#else
  cli();
  reset_cm260();
  /* Now, the problem here is that reset_cm260 can generate an
     interrupt. It seems that this can cause a kernel oops some time
     later. So we wait a while and `service' this interrupt. */
  mdelay(1);
  outw(dc_normal | READ_AHEAD, r_data_control);
  sti();
  printk(" using IRQ %d\n", cm206_irq);
#endif
  if (send_receive_polled(c_drive_configuration) != c_drive_configuration) 
    {
      printk(KERN_INFO " drive not there\n");
      cleanup(1);
      return -EIO;
    }
  e = send_receive_polled(c_gimme);
  printk(KERN_INFO "Firmware revision %d", e & dcf_revision_code);
  if (e & dcf_transfer_rate) printk(" double");
  else printk(" single");
  printk(" speed drive");
  if (e & dcf_motorized_tray) printk(", motorized tray");
  if (request_irq(cm206_irq, cm206_interrupt, 0, "cm206", NULL)) {
    printk("\nUnable to reserve IRQ---aborted\n");
    cleanup(2);
    return -EIO;
  }
  printk(".\n");
  if (devfs_register_blkdev(MAJOR_NR, "cm206", &cdrom_fops) != 0) {
    printk(KERN_INFO "Cannot register for major %d!\n", MAJOR_NR);
    cleanup(3);
    return -EIO;
  }
  cm206_info.dev = MKDEV(MAJOR_NR,0);
  if (register_cdrom(&cm206_info) != 0) {
    printk(KERN_INFO "Cannot register for cdrom %d!\n", MAJOR_NR);
    cleanup(3);
    return -EIO;
  }    
  blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
  blksize_size[MAJOR_NR] = cm206_blocksizes;
  read_ahead[MAJOR_NR] = 16;	/* reads ahead what? */
  init_bh(CM206_BH, cm206_bh);

  memset(cd, 0, sizeof(*cd));	/* give'm some reasonable value */
  cd->sector_last = -1;		/* flag no data buffered */
  cd->adapter_last = -1;
  cd->timer.function = cm206_timeout;
  cd->max_sectors = (inw(r_data_status) & ds_ram_size) ? 24 : 97;
  printk(KERN_INFO "%d kB adapter memory available, "  
	 " %ld bytes kernel memory used.\n", cd->max_sectors*2, size);
  return 0;
}

#ifdef MODULE


static void __init parse_options(void)
{
  int i;
  for (i=0; i<2; i++) {
    if (0x300 <= cm206[i] && i<= 0x370 && cm206[i] % 0x10 == 0) {
      cm206_base = cm206[i];
      auto_probe=0;
    }
    else if (3 <= cm206[i] && cm206[i] <= 15) {
      cm206_irq = cm206[i];
      auto_probe=0;
    }
  }
}

int __cm206_init(void)
{
	parse_options();
#if !defined(AUTO_PROBE_MODULE)
	auto_probe=0;
#endif
	return cm206_init();
}

void __exit cm206_exit(void)
{
  cleanup(4);
  printk(KERN_INFO "cm206 removed\n");
}

module_init(__cm206_init);
module_exit(cm206_exit);
      
#else /* !MODULE */

/* This setup function accepts either `auto' or numbers in the range
 * 3--11 (for irq) or 0x300--0x370 (for base port) or both. */

static int __init cm206_setup(char *s)
{
  int i, p[4];
  
  (void)get_options(s, ARRAY_SIZE(p), p);
  
  if (!strcmp(s, "auto")) auto_probe=1;
  for(i=1; i<=p[0]; i++) {
    if (0x300 <= p[i] && i<= 0x370 && p[i] % 0x10 == 0) {
      cm206_base = p[i];
      auto_probe = 0;
    }
    else if (3 <= p[i] && p[i] <= 15) {
      cm206_irq = p[i];
      auto_probe = 0;
    }
  }
 return 1;
}

__setup("cm206=", cm206_setup);

#endif /* !MODULE */
/*
 * Local variables:
 * compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -fno-strength-reduce -m486 -DMODULE -DMODVERSIONS -include /usr/src/linux/include/linux/modversions.h  -c -o cm206.o cm206.c"
 * End:
 */