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
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
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
/*
 * drivers/usb/usb.c
 *
 * (C) Copyright Linus Torvalds 1999
 * (C) Copyright Johannes Erdfelt 1999-2001
 * (C) Copyright Andreas Gal 1999
 * (C) Copyright Gregory P. Smith 1999
 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
 	more docs, etc)
 * (C) Copyright Yggdrasil Computing, Inc. 2000
 *     (usb_device_id matching changes by Adam J. Richter)
 * (C) Copyright Greg Kroah-Hartman 2002
 *
 * NOTE! This is not actually a driver at all, rather this is
 * just a collection of helper routines that implement the
 * generic USB things that the real drivers can use..
 *
 * Think of this as a "USB library" rather than anything else.
 * It should be considered a slave, with no callbacks. Callbacks
 * are evil.
 */

#include <linux/config.h>

#ifdef CONFIG_USB_DEBUG
	#define DEBUG
#else
	#undef DEBUG
#endif

#include <linux/module.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/interrupt.h>  /* for in_interrupt() */
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/usb.h>

#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>

#include "hcd.h"
#include "usb.h"

extern int  usb_hub_init(void);
extern void usb_hub_cleanup(void);
extern int usb_major_init(void);
extern void usb_major_cleanup(void);


int nousb;		/* Disable USB when built into kernel image */
			/* Not honored on modular build */


static int generic_probe (struct device *dev)
{
	return 0;
}
static int generic_remove (struct device *dev)
{
	return 0;
}

static struct device_driver usb_generic_driver = {
	.name =	"usb",
	.bus = &usb_bus_type,
	.probe = generic_probe,
	.remove = generic_remove,
};

/* needs to be called with BKL held */
int usb_device_probe(struct device *dev)
{
	struct usb_interface * intf = to_usb_interface(dev);
	struct usb_driver * driver = to_usb_driver(dev->driver);
	const struct usb_device_id *id;
	int error = -ENODEV;

	dev_dbg(*dev, "%s\n", __FUNCTION__);

	if (!driver->probe)
		return error;

	if (!try_module_get(driver->owner)) {
		dev_err (*dev, "Can't get a module reference for %s\n", driver->name);
		return error;
	}

	id = usb_match_id (intf, driver->id_table);
	if (id) {
		dev_dbg (*dev, "%s - got id\n", __FUNCTION__);
		down (&driver->serialize);
		error = driver->probe (intf, id);
		up (&driver->serialize);
	}
	if (!error)
		intf->driver = driver;

	module_put(driver->owner);

	return error;
}

int usb_device_remove(struct device *dev)
{
	struct usb_interface *intf;
	struct usb_driver *driver;

	intf = list_entry(dev,struct usb_interface,dev);
	driver = to_usb_driver(dev->driver);

	if (!driver) {
		dev_err(*dev, "%s does not have a valid driver to work with!",
		    __FUNCTION__);
		return -ENODEV;
	}

	if (!try_module_get(driver->owner)) {
		// FIXME this happens even when we just rmmod
		// drivers that aren't in active use...
		dev_err(*dev, "Dieing driver still bound to device.\n");
		return -EIO;
	}

	/* if we sleep here on an umanaged driver 
	 * the holder of the lock guards against 
	 * module unload */
	down(&driver->serialize);

	if (intf->driver && intf->driver->disconnect)
		intf->driver->disconnect(intf);

	/* if driver->disconnect didn't release the interface */
	if (intf->driver)
		usb_driver_release_interface(driver, intf);

	up(&driver->serialize);
	module_put(driver->owner);

	return 0;
}

/**
 * usb_register - register a USB driver
 * @new_driver: USB operations for the driver
 *
 * Registers a USB driver with the USB core.  The list of unattached
 * interfaces will be rescanned whenever a new driver is added, allowing
 * the new driver to attach to any recognized devices.
 * Returns a negative error code on failure and 0 on success.
 * 
 * NOTE: if you want your driver to use the USB major number, you must call
 * usb_register_dev() to enable that functionality.  This function no longer
 * takes care of that.
 */
int usb_register(struct usb_driver *new_driver)
{
	int retval = 0;

	if (nousb)
		return -ENODEV;

	new_driver->driver.name = (char *)new_driver->name;
	new_driver->driver.bus = &usb_bus_type;
	new_driver->driver.probe = usb_device_probe;
	new_driver->driver.remove = usb_device_remove;

	init_MUTEX(&new_driver->serialize);

	retval = driver_register(&new_driver->driver);

	if (!retval) {
		info("registered new driver %s", new_driver->name);
		usbfs_update_special();
	} else {
		err("problem %d when registering driver %s",
			retval, new_driver->name);
	}

	return retval;
}

/**
 * usb_deregister - unregister a USB driver
 * @driver: USB operations of the driver to unregister
 * Context: !in_interrupt (), must be called with BKL held
 *
 * Unlinks the specified driver from the internal USB driver list.
 * 
 * NOTE: If you called usb_register_dev(), you still need to call
 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
 * this * call will no longer do it for you.
 */
void usb_deregister(struct usb_driver *driver)
{
	info("deregistering driver %s", driver->name);

	driver_unregister (&driver->driver);

	usbfs_update_special();
}

/**
 * usb_ifnum_to_if - get the interface object with a given interface number (usbcore-internal)
 * @dev: the device whose current configuration is considered
 * @ifnum: the desired interface
 *
 * This walks the device descriptor for the currently active configuration
 * and returns a pointer to the interface with that particular interface
 * number, or null.
 *
 * Note that configuration descriptors are not required to assign interface
 * numbers sequentially, so that it would be incorrect to assume that
 * the first interface in that descriptor corresponds to interface zero.
 * This routine helps device drivers avoid such mistakes.
 * However, you should make sure that you do the right thing with any
 * alternate settings available for this interfaces.
 */
struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum)
{
	int i;

	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
		if (dev->actconfig->interface[i].altsetting[0]
				.desc.bInterfaceNumber == ifnum)
			return &dev->actconfig->interface[i];

	return NULL;
}

/**
 * usb_epnum_to_ep_desc - get the endpoint object with a given endpoint number
 * @dev: the device whose current configuration is considered
 * @epnum: the desired endpoint
 *
 * This walks the device descriptor for the currently active configuration,
 * and returns a pointer to the endpoint with that particular endpoint
 * number, or null.
 *
 * Note that interface descriptors are not required to assign endpont
 * numbers sequentially, so that it would be incorrect to assume that
 * the first endpoint in that descriptor corresponds to interface zero.
 * This routine helps device drivers avoid such mistakes.
 */
struct usb_endpoint_descriptor *
usb_epnum_to_ep_desc(struct usb_device *dev, unsigned epnum)
{
	int i, j, k;

	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
		for (j = 0; j < dev->actconfig->interface[i].num_altsetting; j++)
			for (k = 0; k < dev->actconfig->interface[i]
				.altsetting[j].desc.bNumEndpoints; k++)
				if (epnum == dev->actconfig->interface[i]
						.altsetting[j].endpoint[k]
						.desc.bEndpointAddress)
					return &dev->actconfig->interface[i]
						.altsetting[j].endpoint[k]
						.desc;

	return NULL;
}

/**
 * usb_driver_claim_interface - bind a driver to an interface
 * @driver: the driver to be bound
 * @iface: the interface to which it will be bound
 * @priv: driver data associated with that interface
 *
 * This is used by usb device drivers that need to claim more than one
 * interface on a device when probing (audio and acm are current examples).
 * No device driver should directly modify internal usb_interface or
 * usb_device structure members.
 *
 * Few drivers should need to use this routine, since the most natural
 * way to bind to an interface is to return the private data from
 * the driver's probe() method.  Any driver that does use this must
 * first be sure that no other driver has claimed the interface, by
 * checking with usb_interface_claimed().
 */
void usb_driver_claim_interface(struct usb_driver *driver, struct usb_interface *iface, void* priv)
{
	if (!iface || !driver)
		return;

	// FIXME change API to report an error in this case
	if (iface->driver)
	    err ("%s driver booted %s off interface %p",
	    	driver->name, iface->driver->name, iface);
	else
	    dbg("%s driver claimed interface %p", driver->name, iface);

	iface->driver = driver;
	usb_set_intfdata(iface, priv);
}

/**
 * usb_interface_claimed - returns true iff an interface is claimed
 * @iface: the interface being checked
 *
 * This should be used by drivers to check other interfaces to see if
 * they are available or not.  If another driver has claimed the interface,
 * they may not claim it.  Otherwise it's OK to claim it using
 * usb_driver_claim_interface().
 *
 * Returns true (nonzero) iff the interface is claimed, else false (zero).
 */
int usb_interface_claimed(struct usb_interface *iface)
{
	if (!iface)
		return 0;

	return (iface->driver != NULL);
} /* usb_interface_claimed() */

/**
 * usb_driver_release_interface - unbind a driver from an interface
 * @driver: the driver to be unbound
 * @iface: the interface from which it will be unbound
 * 
 * This should be used by drivers to release their claimed interfaces.
 * It is normally called in their disconnect() methods, and only for
 * drivers that bound to more than one interface in their probe().
 *
 * When the USB subsystem disconnect()s a driver from some interface,
 * it automatically invokes this method for that interface.  That
 * means that even drivers that used usb_driver_claim_interface()
 * usually won't need to call this.
 */
void usb_driver_release_interface(struct usb_driver *driver, struct usb_interface *iface)
{
	/* this should never happen, don't release something that's not ours */
	if (!iface || iface->driver != driver)
		return;

	iface->driver = NULL;
	usb_set_intfdata(iface, NULL);
}

/**
 * usb_match_id - find first usb_device_id matching device or interface
 * @interface: the interface of interest
 * @id: array of usb_device_id structures, terminated by zero entry
 *
 * usb_match_id searches an array of usb_device_id's and returns
 * the first one matching the device or interface, or null.
 * This is used when binding (or rebinding) a driver to an interface.
 * Most USB device drivers will use this indirectly, through the usb core,
 * but some layered driver frameworks use it directly.
 * These device tables are exported with MODULE_DEVICE_TABLE, through
 * modutils and "modules.usbmap", to support the driver loading
 * functionality of USB hotplugging.
 *
 * What Matches:
 *
 * The "match_flags" element in a usb_device_id controls which
 * members are used.  If the corresponding bit is set, the
 * value in the device_id must match its corresponding member
 * in the device or interface descriptor, or else the device_id
 * does not match.
 *
 * "driver_info" is normally used only by device drivers,
 * but you can create a wildcard "matches anything" usb_device_id
 * as a driver's "modules.usbmap" entry if you provide an id with
 * only a nonzero "driver_info" field.  If you do this, the USB device
 * driver's probe() routine should use additional intelligence to
 * decide whether to bind to the specified interface.
 * 
 * What Makes Good usb_device_id Tables:
 *
 * The match algorithm is very simple, so that intelligence in
 * driver selection must come from smart driver id records.
 * Unless you have good reasons to use another selection policy,
 * provide match elements only in related groups, and order match
 * specifiers from specific to general.  Use the macros provided
 * for that purpose if you can.
 *
 * The most specific match specifiers use device descriptor
 * data.  These are commonly used with product-specific matches;
 * the USB_DEVICE macro lets you provide vendor and product IDs,
 * and you can also match against ranges of product revisions.
 * These are widely used for devices with application or vendor
 * specific bDeviceClass values.
 *
 * Matches based on device class/subclass/protocol specifications
 * are slightly more general; use the USB_DEVICE_INFO macro, or
 * its siblings.  These are used with single-function devices
 * where bDeviceClass doesn't specify that each interface has
 * its own class. 
 *
 * Matches based on interface class/subclass/protocol are the
 * most general; they let drivers bind to any interface on a
 * multiple-function device.  Use the USB_INTERFACE_INFO
 * macro, or its siblings, to match class-per-interface style 
 * devices (as recorded in bDeviceClass).
 *  
 * Within those groups, remember that not all combinations are
 * meaningful.  For example, don't give a product version range
 * without vendor and product IDs; or specify a protocol without
 * its associated class and subclass.
 */   
const struct usb_device_id *
usb_match_id(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_host_interface *intf;
	struct usb_device *dev;

	/* proc_connectinfo in devio.c may call us with id == NULL. */
	if (id == NULL)
		return NULL;

	intf = &interface->altsetting [interface->act_altsetting];
	dev = interface_to_usbdev(interface);

	/* It is important to check that id->driver_info is nonzero,
	   since an entry that is all zeroes except for a nonzero
	   id->driver_info is the way to create an entry that
	   indicates that the driver want to examine every
	   device and interface. */
	for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass ||
	       id->driver_info; id++) {

		if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
		    id->idVendor != dev->descriptor.idVendor)
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
		    id->idProduct != dev->descriptor.idProduct)
			continue;

		/* No need to test id->bcdDevice_lo != 0, since 0 is never
		   greater than any unsigned number. */
		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
		    (id->bcdDevice_lo > dev->descriptor.bcdDevice))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
		    (id->bcdDevice_hi < dev->descriptor.bcdDevice))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
		    (id->bDeviceClass != dev->descriptor.bDeviceClass))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
		    (id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
		    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
		    (id->bInterfaceClass != intf->desc.bInterfaceClass))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
		    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
			continue;

		if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
		    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
			continue;

		return id;
	}

	return NULL;
}

/**
 * usb_find_interface - find usb_interface pointer for driver and device
 * @drv: the driver whose current configuration is considered
 * @kdev: the desired device
 *
 * This walks the driver device list and returns a pointer to the interface 
 * with the matching kdev_t.
 */
struct usb_interface *usb_find_interface(struct usb_driver *drv, kdev_t kdev)
{
	struct list_head *entry;
	struct device *dev;
	struct usb_interface *intf;

	list_for_each(entry, &drv->driver.devices) {
		dev = container_of(entry, struct device, driver_list);

		/* can't look at usb devices, only interfaces */
		if (dev->driver == &usb_generic_driver)
			continue;

		intf = to_usb_interface(dev);
		if (!intf)
			continue;

		if (kdev_same(intf->kdev,kdev)) {
			return intf;
		}
	}

	/* no device found that matches */
	return NULL;	
}

static int usb_device_match (struct device *dev, struct device_driver *drv)
{
	struct usb_interface *intf;
	struct usb_driver *usb_drv;
	const struct usb_device_id *id;

	/* check for generic driver, which we don't match any device with */
	if (drv == &usb_generic_driver)
		return 0;

	intf = to_usb_interface(dev);

	usb_drv = to_usb_driver(drv);
	id = usb_drv->id_table;
	
	id = usb_match_id (intf, usb_drv->id_table);
	if (id)
		return 1;

	return 0;
}


#ifdef	CONFIG_HOTPLUG

/*
 * USB hotplugging invokes what /proc/sys/kernel/hotplug says
 * (normally /sbin/hotplug) when USB devices get added or removed.
 *
 * This invokes a user mode policy agent, typically helping to load driver
 * or other modules, configure the device, and more.  Drivers can provide
 * a MODULE_DEVICE_TABLE to help with module loading subtasks.
 *
 * We're called either from khubd (the typical case) or from root hub
 * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle
 * delays in event delivery.  Use sysfs (and DEVPATH) to make sure the
 * device (and this configuration!) are still present.
 */
static int usb_hotplug (struct device *dev, char **envp, int num_envp,
			char *buffer, int buffer_size)
{
	struct usb_interface *intf;
	struct usb_device *usb_dev;
	char *scratch;
	int i = 0;
	int length = 0;

	dbg ("%s", __FUNCTION__);

	if (!dev)
		return -ENODEV;

	if (dev->driver == &usb_generic_driver)
		return 0;

	intf = to_usb_interface(dev);
	if (!intf)
		return -ENODEV;

	usb_dev = interface_to_usbdev (intf);
	if (!usb_dev)
		return -ENODEV;
	
	if (usb_dev->devnum < 0) {
		dbg ("device already deleted ??");
		return -ENODEV;
	}
	if (!usb_dev->bus) {
		dbg ("bus already removed?");
		return -ENODEV;
	}

	scratch = buffer;

#ifdef	CONFIG_USB_DEVICEFS
	/* If this is available, userspace programs can directly read
	 * all the device descriptors we don't tell them about.  Or
	 * even act as usermode drivers.
	 *
	 * FIXME reduce hardwired intelligence here
	 */
	envp [i++] = scratch;
	length += snprintf (scratch, buffer_size - length,
			    "DEVICE=/proc/bus/usb/%03d/%03d",
			    usb_dev->bus->busnum, usb_dev->devnum);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	scratch += length;
#endif

	/* per-device configurations are common */
	envp [i++] = scratch;
	length += snprintf (scratch, buffer_size - length, "PRODUCT=%x/%x/%x",
			    usb_dev->descriptor.idVendor,
			    usb_dev->descriptor.idProduct,
			    usb_dev->descriptor.bcdDevice);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	scratch += length;

	/* class-based driver binding models */
	envp [i++] = scratch;
	length += snprintf (scratch, buffer_size - length, "TYPE=%d/%d/%d",
			    usb_dev->descriptor.bDeviceClass,
			    usb_dev->descriptor.bDeviceSubClass,
			    usb_dev->descriptor.bDeviceProtocol);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	scratch += length;

	if (usb_dev->descriptor.bDeviceClass == 0) {
		int alt = intf->act_altsetting;

		/* 2.4 only exposed interface zero.  in 2.5, hotplug
		 * agents are called for all interfaces, and can use
		 * $DEVPATH/bInterfaceNumber if necessary.
		 */
		envp [i++] = scratch;
		length += snprintf (scratch, buffer_size - length,
			    "INTERFACE=%d/%d/%d",
			    intf->altsetting[alt].desc.bInterfaceClass,
			    intf->altsetting[alt].desc.bInterfaceSubClass,
			    intf->altsetting[alt].desc.bInterfaceProtocol);
		if ((buffer_size - length <= 0) || (i >= num_envp))
			return -ENOMEM;
		++length;
		scratch += length;

	}
	envp [i++] = 0;

	return 0;
}

#else

static int usb_hotplug (struct device *dev, char **envp,
			int num_envp, char *buffer, int buffer_size)
{
	return -ENODEV;
}

#endif	/* CONFIG_HOTPLUG */

/**
 * usb_alloc_dev - allocate a usb device structure (usbcore-internal)
 * @parent: hub to which device is connected
 * @bus: bus used to access the device
 * Context: !in_interrupt ()
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 */
struct usb_device *usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus)
{
	struct usb_device *dev;

	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	memset(dev, 0, sizeof(*dev));

	device_initialize(&dev->dev);

	usb_bus_get(bus);

	if (!parent)
		dev->devpath [0] = '0';
	dev->bus = bus;
	dev->parent = parent;
	INIT_LIST_HEAD(&dev->filelist);

	init_MUTEX(&dev->serialize);

	if (dev->bus->op->allocate)
		dev->bus->op->allocate(dev);

	return dev;
}

/**
 * usb_get_dev - increments the reference count of the usb device structure
 * @dev: the device being referenced
 *
 * Each live reference to a device should be refcounted.
 *
 * Drivers for USB interfaces should normally record such references in
 * their probe() methods, when they bind to an interface, and release
 * them by calling usb_put_dev(), in their disconnect() methods.
 *
 * A pointer to the device with the incremented reference counter is returned.
 */
struct usb_device *usb_get_dev (struct usb_device *dev)
{
	struct device *tmp;

	if (!dev)
		return NULL;

	tmp = get_device(&dev->dev);
	if (tmp)        
		return to_usb_device(tmp);
	else
		return NULL;
}

/**
 * usb_put_dev - release a use of the usb device structure
 * @dev: device that's been disconnected
 *
 * Must be called when a user of a device is finished with it.  When the last
 * user of the device calls this function, the memory of the device is freed.
 */
void usb_put_dev(struct usb_device *dev)
{
	if (dev)
		put_device(&dev->dev);
}

/**
 * usb_release_dev - free a usb device structure when all users of it are finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this usb device are
 * done.
 */
static void usb_release_dev(struct device *dev)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	if (!udev)
		return;

	if (udev->bus && udev->bus->op && udev->bus->op->deallocate)
		udev->bus->op->deallocate(udev);
	usb_destroy_configuration (udev);
	usb_bus_put (udev->bus);
	kfree (udev);
}


/**
 * usb_get_current_frame_number - return current bus frame number
 * @dev: the device whose bus is being queried
 *
 * Returns the current frame number for the USB host controller
 * used with the given USB device.  This can be used when scheduling
 * isochronous requests.
 *
 * Note that different kinds of host controller have different
 * "scheduling horizons".  While one type might support scheduling only
 * 32 frames into the future, others could support scheduling up to
 * 1024 frames into the future.
 */
int usb_get_current_frame_number(struct usb_device *dev)
{
	return dev->bus->op->get_frame_number (dev);
}

/*-------------------------------------------------------------------*/
/*
 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
 * extra field of the interface and endpoint descriptor structs.
 */

int __usb_get_extra_descriptor(char *buffer, unsigned size, unsigned char type, void **ptr)
{
	struct usb_descriptor_header *header;

	while (size >= sizeof(struct usb_descriptor_header)) {
		header = (struct usb_descriptor_header *)buffer;

		if (header->bLength < 2) {
			err("invalid descriptor length of %d", header->bLength);
			return -1;
		}

		if (header->bDescriptorType == type) {
			*ptr = header;
			return 0;
		}

		buffer += header->bLength;
		size -= header->bLength;
	}
	return -1;
}

/**
 * usb_disconnect - disconnect a device (usbcore-internal)
 * @pdev: pointer to device being disconnected
 * Context: !in_interrupt ()
 *
 * Something got disconnected. Get rid of it, and all of its children.
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 */
void usb_disconnect(struct usb_device **pdev)
{
	struct usb_device * dev = *pdev;
	int i;

	if (!dev)
		return;

	*pdev = NULL;

	dev_info (dev->dev, "USB disconnect, address %d\n", dev->devnum);

	/* Free up all the children before we remove this device */
	for (i = 0; i < USB_MAXCHILDREN; i++) {
		struct usb_device **child = dev->children + i;
		if (*child)
			usb_disconnect(child);
	}

	dev_dbg (dev->dev, "unregistering interfaces\n");
	if (dev->actconfig) {
		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
			struct usb_interface *interface = &dev->actconfig->interface[i];

			/* remove this interface */
			device_unregister(&interface->dev);
		}
	}

	dev_dbg (dev->dev, "unregistering device\n");
	/* Free the device number and remove the /proc/bus/usb entry */
	if (dev->devnum > 0) {
		clear_bit(dev->devnum, dev->bus->devmap.devicemap);
		usbfs_remove_device(dev);
	}
	device_unregister(&dev->dev);

	/* Decrement the reference count, it'll auto free everything when */
	/* it hits 0 which could very well be now */
	usb_put_dev(dev);
}

/**
 * usb_connect - connects a new device during enumeration (usbcore-internal)
 * @dev: partially enumerated device
 *
 * Connect a new USB device. This basically just initializes
 * the USB device information and sets up the topology - it's
 * up to the low-level driver to reset the port and actually
 * do the setup (the upper levels don't know how to do that).
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 */
void usb_connect(struct usb_device *dev)
{
	int devnum;
	// FIXME needs locking for SMP!!
	/* why? this is called only from the hub thread, 
	 * which hopefully doesn't run on multiple CPU's simultaneously 8-)
	 * ... it's also called from modprobe/rmmod/apmd threads as part
	 * of virtual root hub init/reinit.  In the init case, the hub code 
	 * won't have seen this, but not so for reinit ... 
	 */
	dev->descriptor.bMaxPacketSize0 = 8;  /* Start off at 8 bytes  */

	/* Try to allocate the next devnum beginning at bus->devnum_next. */
	devnum = find_next_zero_bit(dev->bus->devmap.devicemap, 128, dev->bus->devnum_next);
	if (devnum >= 128)
		devnum = find_next_zero_bit(dev->bus->devmap.devicemap, 128, 1);

	dev->bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);

	if (devnum < 128) {
		set_bit(devnum, dev->bus->devmap.devicemap);
		dev->devnum = devnum;
	}
}


// hub-only!! ... and only exported for reset/reinit path.
// otherwise used internally, for usb_new_device()
int usb_set_address(struct usb_device *dev)
{
	return usb_control_msg(dev, usb_snddefctrl(dev), USB_REQ_SET_ADDRESS,
		// FIXME USB_CTRL_SET_TIMEOUT
		0, dev->devnum, 0, NULL, 0, HZ * USB_CTRL_GET_TIMEOUT);
}


/* improve on the default device description, if we can ... and
 * while we're at it, maybe show the vendor and product strings.
 */
static void set_device_description (struct usb_device *dev)
{
	void    *buf;
	int	mfgr = dev->descriptor.iManufacturer;
	int	prod = dev->descriptor.iProduct;
	int	vendor_id = dev->descriptor.idVendor;
	int	product_id = dev->descriptor.idProduct;
	char	*mfgr_str, *prod_str;

	/* set default; keep it if there are no strings, or kmalloc fails */
	sprintf (dev->dev.name, "USB device %04x:%04x",
		 vendor_id, product_id);

	if (!(buf = kmalloc(256 * 2, GFP_KERNEL)))
		return;
	
	prod_str = (char *) buf;
	mfgr_str = (char *) buf + 256;

	if (prod && usb_string (dev, prod, prod_str, 256) > 0) {
#ifdef DEBUG
		dev_printk (KERN_INFO, dev->dev, "Product: %s\n", prod_str);
#endif
	} else {
		prod_str = 0;
	}

	if (mfgr && usb_string (dev, mfgr, mfgr_str, 256) > 0) {
#ifdef DEBUG
		dev_printk (KERN_INFO, dev->dev, "Manufacturer: %s\n", mfgr_str);
#endif
	} else {
		mfgr_str = 0;
	}

	/* much like pci ... describe as either:
	 * - both strings:   'product descr (vendor descr)'
	 * - product only:   'product descr (USB device vvvv:pppp)'
	 * - vendor only:    'USB device vvvv:pppp (vendor descr)'
	 * - neither string: 'USB device vvvv:pppp'
	 */

	if (prod_str && mfgr_str) {
		snprintf(dev->dev.name, sizeof dev->dev.name,
			 "%s (%s)", prod_str, mfgr_str);
	} else if (prod_str) {
		snprintf(dev->dev.name, sizeof dev->dev.name,
			 "%s (USB device %04x:%04x)",
			 prod_str, vendor_id, product_id);
	} else if (mfgr_str) {
		snprintf(dev->dev.name, sizeof dev->dev.name,
			 "USB device %04x:%04x (%s)",
			 vendor_id, product_id, mfgr_str);
	}

	kfree(buf);
}

/*
 * By the time we get here, the device has gotten a new device ID
 * and is in the default state. We need to identify the thing and
 * get the ball rolling..
 *
 * Returns 0 for success, != 0 for error.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 */
#define NEW_DEVICE_RETRYS	2
#define SET_ADDRESS_RETRYS	2
int usb_new_device(struct usb_device *dev, struct device *parent)
{
	int err = 0;
	int i;
	int j;

	/*
	 * Set the driver for the usb device to point to the "generic" driver.
	 * This prevents the main usb device from being sent to the usb bus
	 * probe function.  Yes, it's a hack, but a nice one :)
	 *
	 * Do it asap, so more driver model stuff (like the device.h message
	 * utilities) can be used in hcd submit/unlink code paths.
	 */
	usb_generic_driver.bus = &usb_bus_type;
	dev->dev.parent = parent;
	dev->dev.driver = &usb_generic_driver;
	dev->dev.bus = &usb_bus_type;
	dev->dev.release = usb_release_dev;
	usb_get_dev(dev);
	if (dev->dev.bus_id[0] == 0)
		sprintf (&dev->dev.bus_id[0], "%d-%s",
			 dev->bus->busnum, dev->devpath);

	/* dma masks come from the controller; readonly, except to hcd */
	dev->dev.dma_mask = parent->dma_mask;

	/* USB device state == default ... it's not usable yet */

	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
	 * it's fixed size except for full speed devices.
	 */
	switch (dev->speed) {
	case USB_SPEED_HIGH:		/* fixed at 64 */
		i = 64;
		break;
	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
		/* to determine the ep0 maxpacket size, read the first 8
		 * bytes from the device descriptor to get bMaxPacketSize0;
		 * then correct our initial (small) guess.
		 */
		// FALLTHROUGH
	case USB_SPEED_LOW:		/* fixed at 8 */
		i = 8;
		break;
	default:
		return -EINVAL;
	}
	dev->epmaxpacketin [0] = i;
	dev->epmaxpacketout[0] = i;

	for (i = 0; i < NEW_DEVICE_RETRYS; ++i) {

		for (j = 0; j < SET_ADDRESS_RETRYS; ++j) {
			err = usb_set_address(dev);
			if (err >= 0)
				break;
			wait_ms(200);
		}
		if (err < 0) {
			dev_err(dev->dev, "USB device not accepting new address=%d (error=%d)\n",
				dev->devnum, err);
			clear_bit(dev->devnum, dev->bus->devmap.devicemap);
			dev->devnum = -1;
			return 1;
		}

		wait_ms(10);	/* Let the SET_ADDRESS settle */

		/* high and low speed devices don't need this... */
		err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
		if (err >= 8)
			break;
		wait_ms(100);
	}

	if (err < 8) {
		if (err < 0)
			dev_err(dev->dev, "USB device not responding, giving up (error=%d)\n", err);
		else
			dev_err(dev->dev, "USB device descriptor short read (expected %i, got %i)\n", 8, err);
		clear_bit(dev->devnum, dev->bus->devmap.devicemap);
		dev->devnum = -1;
		return 1;
	}
	if (dev->speed == USB_SPEED_FULL) {
		dev->epmaxpacketin [0] = dev->descriptor.bMaxPacketSize0;
		dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
	}

	/* USB device state == addressed ... still not usable */

	err = usb_get_device_descriptor(dev);
	if (err < (signed)sizeof(dev->descriptor)) {
		if (err < 0)
			dev_err(dev->dev, "unable to get device descriptor (error=%d)\n", err);
		else
			dev_err(dev->dev, "USB device descriptor short read (expected %Zi, got %i)\n",
				sizeof(dev->descriptor), err);
	
		clear_bit(dev->devnum, dev->bus->devmap.devicemap);
		dev->devnum = -1;
		return 1;
	}

	err = usb_get_configuration(dev);
	if (err < 0) {
		dev_err(dev->dev, "unable to get device %d configuration (error=%d)\n",
			dev->devnum, err);
		clear_bit(dev->devnum, dev->bus->devmap.devicemap);
		dev->devnum = -1;
		return 1;
	}

	/* we set the default configuration here */
	err = usb_set_configuration(dev, dev->config[0].desc.bConfigurationValue);
	if (err) {
		dev_err(dev->dev, "failed to set device %d default configuration (error=%d)\n",
			dev->devnum, err);
		clear_bit(dev->devnum, dev->bus->devmap.devicemap);
		dev->devnum = -1;
		return 1;
	}

	/* USB device state == configured ... tell the world! */

	dev_dbg(dev->dev, "new device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
		dev->descriptor.iManufacturer, dev->descriptor.iProduct, dev->descriptor.iSerialNumber);
	set_device_description (dev);

#ifdef DEBUG
	if (dev->descriptor.iSerialNumber)
		usb_show_string(dev, "SerialNumber", dev->descriptor.iSerialNumber);
#endif

	/* put into sysfs, with device and config specific files */
	err = device_add (&dev->dev);
	if (err)
		return err;
	usb_create_driverfs_dev_files (dev);

	/* Register all of the interfaces for this device with the driver core.
	 * Remember, interfaces get bound to drivers, not devices. */
	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
		struct usb_interface *interface = &dev->actconfig->interface[i];
		struct usb_interface_descriptor *desc;

		desc = &interface->altsetting [interface->act_altsetting].desc;
		interface->dev.parent = &dev->dev;
		interface->dev.driver = NULL;
		interface->dev.bus = &usb_bus_type;
		interface->dev.dma_mask = parent->dma_mask;
		sprintf (&interface->dev.bus_id[0], "%d-%s:%d",
			 dev->bus->busnum, dev->devpath,
			 desc->bInterfaceNumber);
		if (!desc->iInterface
				|| usb_string (dev, desc->iInterface,
					interface->dev.name,
					sizeof interface->dev.name) <= 0) {
			/* typically devices won't bother with interface
			 * descriptions; this is the normal case.  an
			 * interface's driver might describe it better.
			 * (also: iInterface is per-altsetting ...)
			 */
			sprintf (&interface->dev.name[0],
				"usb-%s-%s interface %d",
				dev->bus->bus_name, dev->devpath,
				desc->bInterfaceNumber);
		}
		dev_dbg (dev->dev, "%s - registering interface %s\n", __FUNCTION__, interface->dev.bus_id);
		device_add (&interface->dev);
		usb_create_driverfs_intf_files (interface);
	}

	/* add a /proc/bus/usb entry */
	usbfs_add_device(dev);

	return 0;
}

/**
 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_DMA_MAP
 * @dev: device the buffer will be used with
 * @size: requested buffer size
 * @mem_flags: affect whether allocation may block
 * @dma: used to return DMA address of buffer
 *
 * Return value is either null (indicating no buffer could be allocated), or
 * the cpu-space pointer to a buffer that may be used to perform DMA to the
 * specified device.  Such cpu-space buffers are returned along with the DMA
 * address (through the pointer provided).
 *
 * These buffers are used with URB_NO_DMA_MAP set in urb->transfer_flags to
 * avoid behaviors like using "DMA bounce buffers", or tying down I/O mapping
 * hardware for long idle periods.  The implementation varies between
 * platforms, depending on details of how DMA will work to this device.
 * Using these buffers also helps prevent cacheline sharing problems on
 * architectures where CPU caches are not DMA-coherent.
 *
 * When the buffer is no longer used, free it with usb_buffer_free().
 */
void *usb_buffer_alloc (
	struct usb_device *dev,
	size_t size,
	int mem_flags,
	dma_addr_t *dma
)
{
	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc)
		return 0;
	return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma);
}

/**
 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
 * @dev: device the buffer was used with
 * @size: requested buffer size
 * @addr: CPU address of buffer
 * @dma: DMA address of buffer
 *
 * This reclaims an I/O buffer, letting it be reused.  The memory must have
 * been allocated using usb_buffer_alloc(), and the parameters must match
 * those provided in that allocation request. 
 */
void usb_buffer_free (
	struct usb_device *dev,
	size_t size,
	void *addr,
	dma_addr_t dma
)
{
	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free)
	    	return;
	dev->bus->op->buffer_free (dev->bus, size, addr, dma);
}

/**
 * usb_buffer_map - create DMA mapping(s) for an urb
 * @urb: urb whose transfer_buffer will be mapped
 *
 * Return value is either null (indicating no buffer could be mapped), or
 * the parameter.  URB_NO_DMA_MAP is added to urb->transfer_flags if the
 * operation succeeds.
 *
 * This call would normally be used for an urb which is reused, perhaps
 * as the target of a large periodic transfer, with usb_buffer_dmasync()
 * calls to synchronize memory and dma state.  It may not be used for
 * control requests.
 *
 * Reverse the effect of this call with usb_buffer_unmap().
 */
struct urb *usb_buffer_map (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| usb_pipecontrol (urb->pipe)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return 0;

	urb->transfer_dma = dma_map_single (controller,
			urb->transfer_buffer, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
	// FIXME generic api broken like pci, can't report errors
	// if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
	urb->transfer_flags |= URB_NO_DMA_MAP;
	return urb;
}

/**
 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
 * @urb: urb whose transfer_buffer will be synchronized
 */
void usb_buffer_dmasync (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return;

	dma_sync_single (controller,
			urb->transfer_dma, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_unmap - free DMA mapping(s) for an urb
 * @urb: urb whose transfer_buffer will be unmapped
 *
 * Reverses the effect of usb_buffer_map().
 */
void usb_buffer_unmap (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return;

	dma_unmap_single (controller,
			urb->transfer_dma, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to map
 * @nents: the number of entries in the scatterlist
 *
 * Return value is either < 0 (indicating no buffers could be mapped), or
 * the number of DMA mapping array entries in the scatterlist.
 *
 * The caller is responsible for placing the resulting DMA addresses from
 * the scatterlist into URB transfer buffer pointers, and for setting the
 * URB_NO_DMA_MAP transfer flag in each of those URBs.
 *
 * Top I/O rates come from queuing URBs, instead of waiting for each one
 * to complete before starting the next I/O.   This is particularly easy
 * to do with scatterlists.  Just allocate and submit one URB for each DMA
 * mapping entry returned, stopping on the first error or when all succeed.
 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
 *
 * This call would normally be used when translating scatterlist requests,
 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
 * may be able to coalesce mappings for improved I/O efficiency.
 *
 * Reverse the effect of this call with usb_buffer_unmap_sg().
 */
int usb_buffer_map_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int nents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| usb_pipecontrol (pipe)
			|| !(bus = dev->bus)
			|| !(controller = bus->controller))
		return -1;

	// FIXME generic api broken like pci, can't report errors
	return dma_map_sg (controller, sg, nents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to synchronize
 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 *
 * Use this when you are re-using a scatterlist's data buffers for
 * another USB request.
 */
void usb_buffer_dmasync_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int n_hw_ents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| !(bus = dev->bus)
			|| !(controller = bus->controller))
		return;

	dma_sync_sg (controller, sg, n_hw_ents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to unmap
 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 *
 * Reverses the effect of usb_buffer_map_sg().
 */
void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int n_hw_ents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| !(bus = dev->bus)
			|| !(controller = bus->controller))
		return;

	dma_unmap_sg (controller, sg, n_hw_ents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}


struct bus_type usb_bus_type = {
	.name =		"usb",
	.match =	usb_device_match,
	.hotplug =	usb_hotplug,
};

#ifndef MODULE

static int __init usb_setup_disable(char *str)
{
	nousb = 1;
	return 1;
}

/* format to disable USB on kernel command line is: nousb */
__setup("nousb", usb_setup_disable);

#endif

/*
 * for external read access to <nousb>
 */
int usb_disabled(void)
{
	return nousb;
}

/*
 * Init
 */
static int __init usb_init(void)
{
	if (nousb) {
		info("USB support disabled\n");
		return 0;
	}

	bus_register(&usb_bus_type);
	usb_major_init();
	usbfs_init();
	usb_hub_init();

	driver_register(&usb_generic_driver);

	return 0;
}

/*
 * Cleanup
 */
static void __exit usb_exit(void)
{
	/* This will matter if shutdown/reboot does exitcalls. */
	if (nousb)
		return;

	driver_unregister(&usb_generic_driver);
	usb_major_cleanup();
	usbfs_cleanup();
	usb_hub_cleanup();
	bus_unregister(&usb_bus_type);
}

subsys_initcall(usb_init);
module_exit(usb_exit);

/*
 * USB may be built into the kernel or be built as modules.
 * These symbols are exported for device (or host controller)
 * driver modules to use.
 */
EXPORT_SYMBOL(usb_epnum_to_ep_desc);

EXPORT_SYMBOL(usb_register);
EXPORT_SYMBOL(usb_deregister);
EXPORT_SYMBOL(usb_disabled);

EXPORT_SYMBOL(usb_device_probe);
EXPORT_SYMBOL(usb_device_remove);

EXPORT_SYMBOL(usb_alloc_dev);
EXPORT_SYMBOL(usb_put_dev);
EXPORT_SYMBOL(usb_get_dev);
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);

EXPORT_SYMBOL(usb_driver_claim_interface);
EXPORT_SYMBOL(usb_interface_claimed);
EXPORT_SYMBOL(usb_driver_release_interface);
EXPORT_SYMBOL(usb_match_id);
EXPORT_SYMBOL(usb_find_interface);

EXPORT_SYMBOL(usb_new_device);
EXPORT_SYMBOL(usb_reset_device);
EXPORT_SYMBOL(usb_connect);
EXPORT_SYMBOL(usb_disconnect);

EXPORT_SYMBOL(__usb_get_extra_descriptor);

EXPORT_SYMBOL(usb_get_current_frame_number);

EXPORT_SYMBOL (usb_buffer_alloc);
EXPORT_SYMBOL (usb_buffer_free);

EXPORT_SYMBOL (usb_buffer_map);
EXPORT_SYMBOL (usb_buffer_dmasync);
EXPORT_SYMBOL (usb_buffer_unmap);

EXPORT_SYMBOL (usb_buffer_map_sg);
EXPORT_SYMBOL (usb_buffer_dmasync_sg);
EXPORT_SYMBOL (usb_buffer_unmap_sg);

MODULE_LICENSE("GPL");