aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/class/usblp.c
blob: 80ec1039d670c928159652e9c3f18fd6210ea674 (plain)
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
/*
 * usblp.c
 *
 * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
 * Copyright (c) 1999 Pavel Machek	<pavel@suse.cz>
 * Copyright (c) 2000 Randy Dunlap	<rdunlap@xenotime.net>
 * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
 # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
 # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
 * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>
 *
 * USB Printer Device Class driver for USB printers and printer cables
 *
 * Sponsored by SuSE
 *
 * ChangeLog:
 *	v0.1 - thorough cleaning, URBification, almost a rewrite
 *	v0.2 - some more cleanups
 *	v0.3 - cleaner again, waitqueue fixes
 *	v0.4 - fixes in unidirectional mode
 *	v0.5 - add DEVICE_ID string support
 *	v0.6 - never time out
 *	v0.7 - fixed bulk-IN read and poll (David Paschal)
 *	v0.8 - add devfs support
 *	v0.9 - fix unplug-while-open paths
 *	v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
 *	v0.11 - add proto_bias option (Pete Zaitcev)
 *	v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
 *	v0.13 - alloc space for statusbuf (<status> not on stack);
 *		use usb_buffer_alloc() for read buf & write buf;
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/lp.h>
#include <linux/mutex.h>
#undef DEBUG
#include <linux/usb.h>

/*
 * Version Information
 */
#define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
#define DRIVER_DESC "USB Printer Device Class driver"

#define USBLP_BUF_SIZE		8192
#define USBLP_BUF_SIZE_IN	1024
#define USBLP_DEVICE_ID_SIZE	1024

/* ioctls: */
#define LPGETSTATUS		0x060b		/* same as in drivers/char/lp.c */
#define IOCNR_GET_DEVICE_ID		1
#define IOCNR_GET_PROTOCOLS		2
#define IOCNR_SET_PROTOCOL		3
#define IOCNR_HP_SET_CHANNEL		4
#define IOCNR_GET_BUS_ADDRESS		5
#define IOCNR_GET_VID_PID		6
#define IOCNR_SOFT_RESET		7
/* Get device_id string: */
#define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
/* The following ioctls were added for http://hpoj.sourceforge.net: */
/* Get two-int array:
 * [0]=current protocol (1=7/1/1, 2=7/1/2, 3=7/1/3),
 * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
#define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
/* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
#define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
/* Set channel number (HP Vendor-specific command): */
#define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
/* Get two-int array: [0]=bus number, [1]=device address: */
#define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
/* Get two-int array: [0]=vendor ID, [1]=product ID: */
#define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
/* Perform class specific soft reset */
#define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);

/*
 * A DEVICE_ID string may include the printer's serial number.
 * It should end with a semi-colon (';').
 * An example from an HP 970C DeskJet printer is (this is one long string,
 * with the serial number changed):
MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
 */

/*
 * USB Printer Requests
 */

#define USBLP_REQ_GET_ID			0x00
#define USBLP_REQ_GET_STATUS			0x01
#define USBLP_REQ_RESET				0x02
#define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST	0x00	/* HP Vendor-specific */

#define USBLP_MINORS		16
#define USBLP_MINOR_BASE	0

#define USBLP_WRITE_TIMEOUT	(5000)			/* 5 seconds */

#define USBLP_FIRST_PROTOCOL	1
#define USBLP_LAST_PROTOCOL	3
#define USBLP_MAX_PROTOCOLS	(USBLP_LAST_PROTOCOL+1)

/*
 * some arbitrary status buffer size;
 * need a status buffer that is allocated via kmalloc(), not on stack
 */
#define STATUS_BUF_SIZE		8

/*
 * Locks down the locking order:
 * ->wmut locks wstatus.
 * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
 * [rw]status. We only touch status when we know the side idle.
 * ->lock locks what interrupt accesses.
 */
struct usblp {
	struct usb_device 	*dev;			/* USB device */
	struct mutex		wmut;
	struct mutex		mut;
	spinlock_t		lock;		/* locks rcomplete, wcomplete */
	char			*readbuf;		/* read transfer_buffer */
	char			*statusbuf;		/* status transfer_buffer */
	struct usb_anchor	urbs;
	wait_queue_head_t	rwait, wwait;
	int			readcount;		/* Counter for reads */
	int			ifnum;			/* Interface number */
	struct usb_interface	*intf;			/* The interface */
	/* Alternate-setting numbers and endpoints for each protocol
	 * (7/1/{index=1,2,3}) that the device supports: */
	struct {
		int				alt_setting;
		struct usb_endpoint_descriptor	*epwrite;
		struct usb_endpoint_descriptor	*epread;
	}			protocol[USBLP_MAX_PROTOCOLS];
	int			current_protocol;
	int			minor;			/* minor number of device */
	int			wcomplete, rcomplete;
	int			wstatus;	/* bytes written or error */
	int			rstatus;	/* bytes ready or error */
	unsigned int		quirks;			/* quirks flags */
	unsigned char		used;			/* True if open */
	unsigned char		present;		/* True if not disconnected */
	unsigned char		bidir;			/* interface is bidirectional */
	unsigned char		sleeping;		/* interface is suspended */
	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
							/* first 2 bytes are (big-endian) length */
};

#ifdef DEBUG
static void usblp_dump(struct usblp *usblp) {
	int p;

	dbg("usblp=0x%p", usblp);
	dbg("dev=0x%p", usblp->dev);
	dbg("present=%d", usblp->present);
	dbg("readbuf=0x%p", usblp->readbuf);
	dbg("readcount=%d", usblp->readcount);
	dbg("ifnum=%d", usblp->ifnum);
    for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
	dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
	dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
	dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
    }
	dbg("current_protocol=%d", usblp->current_protocol);
	dbg("minor=%d", usblp->minor);
	dbg("wstatus=%d", usblp->wstatus);
	dbg("rstatus=%d", usblp->rstatus);
	dbg("quirks=%d", usblp->quirks);
	dbg("used=%d", usblp->used);
	dbg("bidir=%d", usblp->bidir);
	dbg("sleeping=%d", usblp->sleeping);
	dbg("device_id_string=\"%s\"",
		usblp->device_id_string ?
			usblp->device_id_string + 2 :
			(unsigned char *)"(null)");
}
#endif

/* Quirks: various printer quirks are handled by this table & its flags. */

struct quirk_printer_struct {
	__u16 vendorId;
	__u16 productId;
	unsigned int quirks;
};

#define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
#define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
#define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */

static const struct quirk_printer_struct quirk_printers[] = {
	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */   
	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */   
	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
	{ 0, 0 }
};

static int usblp_wwait(struct usblp *usblp, int nonblock);
static int usblp_wtest(struct usblp *usblp, int nonblock);
static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
static int usblp_rtest(struct usblp *usblp, int nonblock);
static int usblp_submit_read(struct usblp *usblp);
static int usblp_select_alts(struct usblp *usblp);
static int usblp_set_protocol(struct usblp *usblp, int protocol);
static int usblp_cache_device_id_string(struct usblp *usblp);

/* forward reference to make our lives easier */
static struct usb_driver usblp_driver;
static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */

/*
 * Functions for usblp control messages.
 */

static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
{
	int retval;
	int index = usblp->ifnum;

	/* High byte has the interface index.
	   Low byte has the alternate setting.
	 */
	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS)) {
	  index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
	}

	retval = usb_control_msg(usblp->dev,
		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
		request, type | dir | recip, value, index, buf, len, USBLP_WRITE_TIMEOUT);
	dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
		request, !!dir, recip, value, index, len, retval);
	return retval < 0 ? retval : 0;
}

#define usblp_read_status(usblp, status)\
	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
#define usblp_get_id(usblp, config, id, maxlen)\
	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
#define usblp_reset(usblp)\
	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)

#define usblp_hp_channel_change_request(usblp, channel, buffer) \
	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)

/*
 * See the description for usblp_select_alts() below for the usage
 * explanation.  Look into your /proc/bus/usb/devices and dmesg in
 * case of any trouble.
 */
static int proto_bias = -1;

/*
 * URB callback.
 */

static void usblp_bulk_read(struct urb *urb)
{
	struct usblp *usblp = urb->context;

	if (usblp->present && usblp->used) {
		if (urb->status)
			printk(KERN_WARNING "usblp%d: "
			    "nonzero read bulk status received: %d\n",
			    usblp->minor, urb->status);
	}
	spin_lock(&usblp->lock);
	if (urb->status < 0)
		usblp->rstatus = urb->status;
	else
		usblp->rstatus = urb->actual_length;
	usblp->rcomplete = 1;
	wake_up(&usblp->rwait);
	spin_unlock(&usblp->lock);

	usb_free_urb(urb);
}

static void usblp_bulk_write(struct urb *urb)
{
	struct usblp *usblp = urb->context;

	if (usblp->present && usblp->used) {
		if (urb->status)
			printk(KERN_WARNING "usblp%d: "
			    "nonzero write bulk status received: %d\n",
			    usblp->minor, urb->status);
	}
	spin_lock(&usblp->lock);
	if (urb->status < 0)
		usblp->wstatus = urb->status;
	else
		usblp->wstatus = urb->actual_length;
	usblp->wcomplete = 1;
	wake_up(&usblp->wwait);
	spin_unlock(&usblp->lock);

	/* XXX Use usb_setup_bulk_urb when available. Talk to Marcel. */
	kfree(urb->transfer_buffer);
	urb->transfer_buffer = NULL;	/* Not refcounted, so to be safe... */
	usb_free_urb(urb);
}

/*
 * Get and print printer errors.
 */

static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };

static int usblp_check_status(struct usblp *usblp, int err)
{
	unsigned char status, newerr = 0;
	int error;

	error = usblp_read_status (usblp, usblp->statusbuf);
	if (error < 0) {
		if (printk_ratelimit())
			printk(KERN_ERR
				"usblp%d: error %d reading printer status\n",
				usblp->minor, error);
		return 0;
	}

	status = *usblp->statusbuf;

	if (~status & LP_PERRORP)
		newerr = 3;
	if (status & LP_POUTPA)
		newerr = 1;
	if (~status & LP_PSELECD)
		newerr = 2;

	if (newerr != err) {
		printk(KERN_INFO "usblp%d: %s\n",
		   usblp->minor, usblp_messages[newerr]);
	}

	return newerr;
}

static int handle_bidir (struct usblp *usblp)
{
	if (usblp->bidir && usblp->used && !usblp->sleeping) {
		if (usblp_submit_read(usblp) < 0)
			return -EIO;
	}
	return 0;
}

/*
 * File op functions.
 */

static int usblp_open(struct inode *inode, struct file *file)
{
	int minor = iminor(inode);
	struct usblp *usblp;
	struct usb_interface *intf;
	int retval;

	if (minor < 0)
		return -ENODEV;

	mutex_lock (&usblp_mutex);

	retval = -ENODEV;
	intf = usb_find_interface(&usblp_driver, minor);
	if (!intf) {
		goto out;
	}
	usblp = usb_get_intfdata (intf);
	if (!usblp || !usblp->dev || !usblp->present)
		goto out;

	retval = -EBUSY;
	if (usblp->used)
		goto out;

	/*
	 * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
	 * This is #if 0-ed because we *don't* want to fail an open
	 * just because the printer is off-line.
	 */
#if 0
	if ((retval = usblp_check_status(usblp, 0))) {
		retval = retval > 1 ? -EIO : -ENOSPC;
		goto out;
	}
#else
	retval = 0;
#endif

	retval = usb_autopm_get_interface(intf);
	if (retval < 0)
		goto out;
	usblp->used = 1;
	file->private_data = usblp;

	usblp->wcomplete = 1; /* we begin writeable */
	usblp->wstatus = 0;
	usblp->rcomplete = 0;

	if (handle_bidir(usblp) < 0) {
		usblp->used = 0;
		file->private_data = NULL;
		retval = -EIO;
	}
out:
	mutex_unlock (&usblp_mutex);
	return retval;
}

static void usblp_cleanup (struct usblp *usblp)
{
	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);

	kfree(usblp->readbuf);
	kfree (usblp->device_id_string);
	kfree (usblp->statusbuf);
	kfree (usblp);
}

static void usblp_unlink_urbs(struct usblp *usblp)
{
	usb_kill_anchored_urbs(&usblp->urbs);
}

static int usblp_release(struct inode *inode, struct file *file)
{
	struct usblp *usblp = file->private_data;

	mutex_lock (&usblp_mutex);
	usblp->used = 0;
	if (usblp->present) {
		usblp_unlink_urbs(usblp);
		usb_autopm_put_interface(usblp->intf);
	} else 		/* finish cleanup from disconnect */
		usblp_cleanup (usblp);
	mutex_unlock (&usblp_mutex);
	return 0;
}

/* No kernel lock - fine */
static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
{
	int ret;
	unsigned long flags;

	struct usblp *usblp = file->private_data;
	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
	poll_wait(file, &usblp->rwait, wait);
	poll_wait(file, &usblp->wwait, wait);
	spin_lock_irqsave(&usblp->lock, flags);
	ret = ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
 			       | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
	spin_unlock_irqrestore(&usblp->lock, flags);
	return ret;
}

static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usblp *usblp = file->private_data;
	int length, err, i;
	unsigned char newChannel;
	int status;
	int twoints[2];
	int retval = 0;

	mutex_lock (&usblp->mut);
	if (!usblp->present) {
		retval = -ENODEV;
		goto done;
	}

	if (usblp->sleeping) {
		retval = -ENODEV;
		goto done;
	}

	dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", cmd, _IOC_TYPE(cmd),
		_IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd) );

	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */

		switch (_IOC_NR(cmd)) {

			case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
				if (_IOC_DIR(cmd) != _IOC_READ) {
					retval = -EINVAL;
					goto done;
				}

				length = usblp_cache_device_id_string(usblp);
				if (length < 0) {
					retval = length;
					goto done;
				}
				if (length > _IOC_SIZE(cmd))
					length = _IOC_SIZE(cmd); /* truncate */

				if (copy_to_user((void __user *) arg,
						usblp->device_id_string,
						(unsigned long) length)) {
					retval = -EFAULT;
					goto done;
				}

				break;

			case IOCNR_GET_PROTOCOLS:
				if (_IOC_DIR(cmd) != _IOC_READ ||
				    _IOC_SIZE(cmd) < sizeof(twoints)) {
					retval = -EINVAL;
					goto done;
				}

				twoints[0] = usblp->current_protocol;
				twoints[1] = 0;
				for (i = USBLP_FIRST_PROTOCOL;
				     i <= USBLP_LAST_PROTOCOL; i++) {
					if (usblp->protocol[i].alt_setting >= 0)
						twoints[1] |= (1<<i);
				}

				if (copy_to_user((void __user *)arg,
						(unsigned char *)twoints,
						sizeof(twoints))) {
					retval = -EFAULT;
					goto done;
				}

				break;

			case IOCNR_SET_PROTOCOL:
				if (_IOC_DIR(cmd) != _IOC_WRITE) {
					retval = -EINVAL;
					goto done;
				}

#ifdef DEBUG
				if (arg == -10) {
					usblp_dump(usblp);
					break;
				}
#endif

				usblp_unlink_urbs(usblp);
				retval = usblp_set_protocol(usblp, arg);
				if (retval < 0) {
					usblp_set_protocol(usblp,
						usblp->current_protocol);
				}
				break;

			case IOCNR_HP_SET_CHANNEL:
				if (_IOC_DIR(cmd) != _IOC_WRITE ||
				    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
				    usblp->quirks & USBLP_QUIRK_BIDIR) {
					retval = -EINVAL;
					goto done;
				}

				err = usblp_hp_channel_change_request(usblp,
					arg, &newChannel);
				if (err < 0) {
					err("usblp%d: error = %d setting "
						"HP channel",
						usblp->minor, err);
					retval = -EIO;
					goto done;
				}

				dbg("usblp%d requested/got HP channel %ld/%d",
					usblp->minor, arg, newChannel);
				break;

			case IOCNR_GET_BUS_ADDRESS:
				if (_IOC_DIR(cmd) != _IOC_READ ||
				    _IOC_SIZE(cmd) < sizeof(twoints)) {
					retval = -EINVAL;
					goto done;
				}

				twoints[0] = usblp->dev->bus->busnum;
				twoints[1] = usblp->dev->devnum;
				if (copy_to_user((void __user *)arg,
						(unsigned char *)twoints,
						sizeof(twoints))) {
					retval = -EFAULT;
					goto done;
				}

				dbg("usblp%d is bus=%d, device=%d",
					usblp->minor, twoints[0], twoints[1]);
				break;

			case IOCNR_GET_VID_PID:
				if (_IOC_DIR(cmd) != _IOC_READ ||
				    _IOC_SIZE(cmd) < sizeof(twoints)) {
					retval = -EINVAL;
					goto done;
				}

				twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
				twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
				if (copy_to_user((void __user *)arg,
						(unsigned char *)twoints,
						sizeof(twoints))) {
					retval = -EFAULT;
					goto done;
				}

				dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
					usblp->minor, twoints[0], twoints[1]);
				break;

			case IOCNR_SOFT_RESET:
				if (_IOC_DIR(cmd) != _IOC_NONE) {
					retval = -EINVAL;
					goto done;
				}
				retval = usblp_reset(usblp);
				break;
			default:
				retval = -ENOTTY;
		}
	else	/* old-style ioctl value */
		switch (cmd) {

			case LPGETSTATUS:
				if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
					if (printk_ratelimit())
						printk(KERN_ERR "usblp%d:"
						    "failed reading printer status (%d)\n",
						    usblp->minor, retval);
					retval = -EIO;
					goto done;
				}
				status = *usblp->statusbuf;
				if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
					retval = -EFAULT;
				break;

			default:
				retval = -ENOTTY;
		}

done:
	mutex_unlock (&usblp->mut);
	return retval;
}

static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	struct usblp *usblp = file->private_data;
	char *writebuf;
	struct urb *writeurb;
	int rv;
	int transfer_length;
	ssize_t writecount = 0;

	if (mutex_lock_interruptible(&usblp->wmut)) {
		rv = -EINTR;
		goto raise_biglock;
	}
	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
		goto raise_wait;

	while (writecount < count) {
		/*
		 * Step 1: Submit next block.
		 */
		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
			transfer_length = USBLP_BUF_SIZE;

		rv = -ENOMEM;
		if ((writebuf = kmalloc(USBLP_BUF_SIZE, GFP_KERNEL)) == NULL)
			goto raise_buf;
		if ((writeurb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
			goto raise_urb;
		usb_fill_bulk_urb(writeurb, usblp->dev,
			usb_sndbulkpipe(usblp->dev,
			  usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
			writebuf, transfer_length, usblp_bulk_write, usblp);
		usb_anchor_urb(writeurb, &usblp->urbs);

		if (copy_from_user(writebuf,
				   buffer + writecount, transfer_length)) {
			rv = -EFAULT;
			goto raise_badaddr;
		}

		spin_lock_irq(&usblp->lock);
		usblp->wcomplete = 0;
		spin_unlock_irq(&usblp->lock);
		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
			usblp->wstatus = 0;
			spin_lock_irq(&usblp->lock);
			usblp->wcomplete = 1;
			wake_up(&usblp->wwait);
			spin_unlock_irq(&usblp->lock);
			if (rv != -ENOMEM)
				rv = -EIO;
			goto raise_submit;
		}

		/*
		 * Step 2: Wait for transfer to end, collect results.
		 */
		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
		if (rv < 0) {
			if (rv == -EAGAIN) {
				/* Presume that it's going to complete well. */
				writecount += transfer_length;
			}
			/* Leave URB dangling, to be cleaned on close. */
			goto collect_error;
		}

		if (usblp->wstatus < 0) {
			usblp_check_status(usblp, 0);
			rv = -EIO;
			goto collect_error;
		}
		/*
		 * This is critical: it must be our URB, not other writer's.
		 * The wmut exists mainly to cover us here.
		 */
		writecount += usblp->wstatus;
	}

	mutex_unlock(&usblp->wmut);
	return writecount;

raise_submit:
raise_badaddr:
	usb_unanchor_urb(writeurb);
	usb_free_urb(writeurb);
raise_urb:
	kfree(writebuf);
raise_buf:
raise_wait:
collect_error:		/* Out of raise sequence */
	mutex_unlock(&usblp->wmut);
raise_biglock:
	return writecount ? writecount : rv;
}

/*
 * Notice that we fail to restart in a few cases: on EFAULT, on restart
 * error, etc. This is the historical behaviour. In all such cases we return
 * EIO, and applications loop in order to get the new read going.
 */
static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
{
	struct usblp *usblp = file->private_data;
	ssize_t count;
	ssize_t avail;
	int rv;

	if (!usblp->bidir)
		return -EINVAL;

	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
	if (rv < 0)
		return rv;

	if ((avail = usblp->rstatus) < 0) {
		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
		    usblp->minor, (int)avail);
		usblp_submit_read(usblp);
		count = -EIO;
		goto done;
	}

	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
	if (count != 0 &&
	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
		count = -EFAULT;
		goto done;
	}

	if ((usblp->readcount += count) == avail) {
		if (usblp_submit_read(usblp) < 0) {
			/* We don't want to leak USB return codes into errno. */
			if (count == 0)
				count = -EIO;
			goto done;
		}
	}

done:
	mutex_unlock (&usblp->mut);
	return count;
}

/*
 * Wait for the write path to come idle.
 * This is called under the ->wmut, so the idle path stays idle.
 *
 * Our write path has a peculiar property: it does not buffer like a tty,
 * but waits for the write to succeed. This allows our ->release to bug out
 * without waiting for writes to drain. But it obviously does not work
 * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
 * select(2) or poll(2) to wait for the buffer to drain before closing.
 * Alternatively, set blocking mode with fcntl and issue a zero-size write.
 *
 * Old v0.13 code had a non-functional timeout for wait_event(). Someone forgot
 * to check the return code for timeout expiration, so it had no effect.
 * Apparently, it was intended to check for error conditons, such as out
 * of paper. It is going to return when we settle things with CUPS. XXX
 */
static int usblp_wwait(struct usblp *usblp, int nonblock)
{
	DECLARE_WAITQUEUE(waita, current);
	int rc;

	add_wait_queue(&usblp->wwait, &waita);
	for (;;) {
		if (mutex_lock_interruptible(&usblp->mut)) {
			rc = -EINTR;
			break;
		}
		set_current_state(TASK_INTERRUPTIBLE);
		if ((rc = usblp_wtest(usblp, nonblock)) < 0) {
			mutex_unlock(&usblp->mut);
			break;
		}
		mutex_unlock(&usblp->mut);
		if (rc == 0)
			break;
		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&usblp->wwait, &waita);
	return rc;
}

static int usblp_wtest(struct usblp *usblp, int nonblock)
{
	unsigned long flags;

	if (!usblp->present)
		return -ENODEV;
	if (signal_pending(current))
		return -EINTR;
	spin_lock_irqsave(&usblp->lock, flags);
	if (usblp->wcomplete) {
		spin_unlock_irqrestore(&usblp->lock, flags);
		return 0;
	}
	spin_unlock_irqrestore(&usblp->lock, flags);
	if (usblp->sleeping)
		return -ENODEV;
	if (nonblock)
		return -EAGAIN;
	return 1;
}

/*
 * Wait for read bytes to become available. This probably should have been
 * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
 * name for functions which lock and return.
 *
 * We do not use wait_event_interruptible because it makes locking iffy.
 */
static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
{
	DECLARE_WAITQUEUE(waita, current);
	int rc;

	add_wait_queue(&usblp->rwait, &waita);
	for (;;) {
		if (mutex_lock_interruptible(&usblp->mut)) {
			rc = -EINTR;
			break;
		}
		set_current_state(TASK_INTERRUPTIBLE);
		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
			mutex_unlock(&usblp->mut);
			break;
		}
		if (rc == 0)	/* Keep it locked */
			break;
		mutex_unlock(&usblp->mut);
		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&usblp->rwait, &waita);
	return rc;
}

static int usblp_rtest(struct usblp *usblp, int nonblock)
{
	unsigned long flags;

	if (!usblp->present)
		return -ENODEV;
	if (signal_pending(current))
		return -EINTR;
	spin_lock_irqsave(&usblp->lock, flags);
	if (usblp->rcomplete) {
		spin_unlock_irqrestore(&usblp->lock, flags);
		return 0;
	}
	spin_unlock_irqrestore(&usblp->lock, flags);
	if (usblp->sleeping)
		return -ENODEV;
	if (nonblock)
		return -EAGAIN;
	return 1;
}

/*
 * Please check ->bidir and other such things outside for now.
 */
static int usblp_submit_read(struct usblp *usblp)
{
	struct urb *urb;
	unsigned long flags;
	int rc;

	rc = -ENOMEM;
	if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == NULL)
		goto raise_urb;

	usb_fill_bulk_urb(urb, usblp->dev,
		usb_rcvbulkpipe(usblp->dev,
		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
		usblp->readbuf, USBLP_BUF_SIZE_IN,
		usblp_bulk_read, usblp);
	usb_anchor_urb(urb, &usblp->urbs);

	spin_lock_irqsave(&usblp->lock, flags);
	usblp->readcount = 0; /* XXX Why here? */
	usblp->rcomplete = 0;
	spin_unlock_irqrestore(&usblp->lock, flags);
	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
		dbg("error submitting urb (%d)", rc);
		spin_lock_irqsave(&usblp->lock, flags);
		usblp->rstatus = rc;
		usblp->rcomplete = 1;
		spin_unlock_irqrestore(&usblp->lock, flags);
		goto raise_submit;
	}

	return 0;

raise_submit:
	usb_unanchor_urb(urb);
	usb_free_urb(urb);
raise_urb:
	return rc;
}

/*
 * Checks for printers that have quirks, such as requiring unidirectional
 * communication but reporting bidirectional; currently some HP printers
 * have this flaw (HP 810, 880, 895, etc.), or needing an init string
 * sent at each open (like some Epsons).
 * Returns 1 if found, 0 if not found.
 *
 * HP recommended that we use the bidirectional interface but
 * don't attempt any bulk IN transfers from the IN endpoint.
 * Here's some more detail on the problem:
 * The problem is not that it isn't bidirectional though. The problem
 * is that if you request a device ID, or status information, while
 * the buffers are full, the return data will end up in the print data
 * buffer. For example if you make sure you never request the device ID
 * while you are sending print data, and you don't try to query the
 * printer status every couple of milliseconds, you will probably be OK.
 */
static unsigned int usblp_quirks (__u16 vendor, __u16 product)
{
	int i;

	for (i = 0; quirk_printers[i].vendorId; i++) {
		if (vendor == quirk_printers[i].vendorId &&
		    product == quirk_printers[i].productId)
			return quirk_printers[i].quirks;
 	}
	return 0;
}

static const struct file_operations usblp_fops = {
	.owner =	THIS_MODULE,
	.read =		usblp_read,
	.write =	usblp_write,
	.poll =		usblp_poll,
	.unlocked_ioctl =	usblp_ioctl,
	.compat_ioctl =		usblp_ioctl,
	.open =		usblp_open,
	.release =	usblp_release,
};

static struct usb_class_driver usblp_class = {
	.name =		"lp%d",
	.fops =		&usblp_fops,
	.minor_base =	USBLP_MINOR_BASE,
};

static ssize_t usblp_show_ieee1284_id(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct usblp *usblp = usb_get_intfdata (intf);

	if (usblp->device_id_string[0] == 0 &&
	    usblp->device_id_string[1] == 0)
		return 0;

	return sprintf(buf, "%s", usblp->device_id_string+2);
}

static DEVICE_ATTR(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);

static int usblp_probe(struct usb_interface *intf,
		       const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev (intf);
	struct usblp *usblp = NULL;
	int protocol;
	int retval;

	/* Malloc and start initializing usblp structure so we can use it
	 * directly. */
	if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
		retval = -ENOMEM;
		goto abort;
	}
	usblp->dev = dev;
	mutex_init(&usblp->wmut);
	mutex_init (&usblp->mut);
	spin_lock_init(&usblp->lock);
	init_waitqueue_head(&usblp->rwait);
	init_waitqueue_head(&usblp->wwait);
	init_usb_anchor(&usblp->urbs);
	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
	usblp->intf = intf;

	/* Malloc device ID string buffer to the largest expected length,
	 * since we can re-query it on an ioctl and a dynamic string
	 * could change in length. */
	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
		retval = -ENOMEM;
		goto abort;
	}

	/*
	 * Allocate read buffer. We somewhat wastefully
	 * malloc both regardless of bidirectionality, because the
	 * alternate setting can be changed later via an ioctl.
	 */
	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
		retval = -ENOMEM;
		goto abort;
	}

	/* Allocate buffer for printer status */
	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
	if (!usblp->statusbuf) {
		retval = -ENOMEM;
		goto abort;
	}

	/* Lookup quirks for this printer. */
	usblp->quirks = usblp_quirks(
		le16_to_cpu(dev->descriptor.idVendor),
		le16_to_cpu(dev->descriptor.idProduct));

	/* Analyze and pick initial alternate settings and endpoints. */
	protocol = usblp_select_alts(usblp);
	if (protocol < 0) {
		dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
			le16_to_cpu(dev->descriptor.idVendor),
			le16_to_cpu(dev->descriptor.idProduct));
		retval = -ENODEV;
		goto abort;
	}

	/* Setup the selected alternate setting and endpoints. */
	if (usblp_set_protocol(usblp, protocol) < 0) {
		retval = -ENODEV;	/* ->probe isn't ->ioctl */
		goto abort;
	}

	/* Retrieve and store the device ID string. */
	usblp_cache_device_id_string(usblp);
	retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
	if (retval)
		goto abort_intfdata;

#ifdef DEBUG
	usblp_check_status(usblp, 0);
#endif

	usb_set_intfdata (intf, usblp);

	usblp->present = 1;

	retval = usb_register_dev(intf, &usblp_class);
	if (retval) {
		printk(KERN_ERR "usblp: Not able to get a minor"
		    " (base %u, slice default): %d\n",
		    USBLP_MINOR_BASE, retval);
		goto abort_intfdata;
	}
	usblp->minor = intf->minor;
	printk(KERN_INFO "usblp%d: USB %sdirectional printer dev %d "
		"if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
		usblp->ifnum,
		usblp->protocol[usblp->current_protocol].alt_setting,
		usblp->current_protocol,
		le16_to_cpu(usblp->dev->descriptor.idVendor),
		le16_to_cpu(usblp->dev->descriptor.idProduct));

	return 0;

abort_intfdata:
	usb_set_intfdata (intf, NULL);
	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
abort:
	if (usblp) {
		kfree(usblp->readbuf);
		kfree(usblp->statusbuf);
		kfree(usblp->device_id_string);
		kfree(usblp);
	}
	return retval;
}

/*
 * We are a "new" style driver with usb_device_id table,
 * but our requirements are too intricate for simple match to handle.
 *
 * The "proto_bias" option may be used to specify the preferred protocol
 * for all USB printers (1=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
 * supports the preferred protocol, then we bind to it.
 *
 * The best interface for us is 7/1/2, because it is compatible
 * with a stream of characters. If we find it, we bind to it.
 *
 * Note that the people from hpoj.sourceforge.net need to be able to
 * bind to 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
 *
 * Failing 7/1/2, we look for 7/1/3, even though it's probably not
 * stream-compatible, because this matches the behaviour of the old code.
 *
 * If nothing else, we bind to 7/1/1 - the unidirectional interface.
 */
static int usblp_select_alts(struct usblp *usblp)
{
	struct usb_interface *if_alt;
	struct usb_host_interface *ifd;
	struct usb_endpoint_descriptor *epd, *epwrite, *epread;
	int p, i, e;

	if_alt = usblp->intf;

	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
		usblp->protocol[p].alt_setting = -1;

	/* Find out what we have. */
	for (i = 0; i < if_alt->num_altsetting; i++) {
		ifd = &if_alt->altsetting[i];

		if (ifd->desc.bInterfaceClass != 7 || ifd->desc.bInterfaceSubClass != 1)
			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
				continue;

		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
			continue;

		/* Look for bulk OUT and IN endpoints. */
		epwrite = epread = NULL;
		for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
			epd = &ifd->endpoint[e].desc;

			if (usb_endpoint_is_bulk_out(epd))
				if (!epwrite)
					epwrite = epd;

			if (usb_endpoint_is_bulk_in(epd))
				if (!epread)
					epread = epd;
		}

		/* Ignore buggy hardware without the right endpoints. */
		if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
			continue;

		/* Turn off reads for 7/1/1 (unidirectional) interfaces
		 * and buggy bidirectional printers. */
		if (ifd->desc.bInterfaceProtocol == 1) {
			epread = NULL;
		} else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
			printk(KERN_INFO "usblp%d: Disabling reads from "
			    "problematic bidirectional printer\n",
			    usblp->minor);
			epread = NULL;
		}

		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
				ifd->desc.bAlternateSetting;
		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
	}

	/* If our requested protocol is supported, then use it. */
	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
	    proto_bias <= USBLP_LAST_PROTOCOL &&
	    usblp->protocol[proto_bias].alt_setting != -1)
		return proto_bias;

	/* Ordering is important here. */
	if (usblp->protocol[2].alt_setting != -1)
		return 2;
	if (usblp->protocol[1].alt_setting != -1)
		return 1;
	if (usblp->protocol[3].alt_setting != -1)
		return 3;

	/* If nothing is available, then don't bind to this device. */
	return -1;
}

static int usblp_set_protocol(struct usblp *usblp, int protocol)
{
	int r, alts;

	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
		return -EINVAL;

	alts = usblp->protocol[protocol].alt_setting;
	if (alts < 0)
		return -EINVAL;
	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
	if (r < 0) {
		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
			alts, usblp->ifnum);
		return r;
	}

	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
	usblp->current_protocol = protocol;
	dbg("usblp%d set protocol %d", usblp->minor, protocol);
	return 0;
}

/* Retrieves and caches device ID string.
 * Returns length, including length bytes but not null terminator.
 * On error, returns a negative errno value. */
static int usblp_cache_device_id_string(struct usblp *usblp)
{
	int err, length;

	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
	if (err < 0) {
		dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
			usblp->minor, err);
		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
		return -EIO;
	}

	/* First two bytes are length in big-endian.
	 * They count themselves, and we copy them into
	 * the user's buffer. */
	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
	if (length < 2)
		length = 2;
	else if (length >= USBLP_DEVICE_ID_SIZE)
		length = USBLP_DEVICE_ID_SIZE - 1;
	usblp->device_id_string[length] = '\0';

	dbg("usblp%d Device ID string [len=%d]=\"%s\"",
		usblp->minor, length, &usblp->device_id_string[2]);

	return length;
}

static void usblp_disconnect(struct usb_interface *intf)
{
	struct usblp *usblp = usb_get_intfdata (intf);

	usb_deregister_dev(intf, &usblp_class);

	if (!usblp || !usblp->dev) {
		err("bogus disconnect");
		BUG ();
	}

	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);

	mutex_lock (&usblp_mutex);
	mutex_lock (&usblp->mut);
	usblp->present = 0;
	wake_up(&usblp->wwait);
	wake_up(&usblp->rwait);
	usb_set_intfdata (intf, NULL);

	usblp_unlink_urbs(usblp);
	mutex_unlock (&usblp->mut);

	if (!usblp->used)
		usblp_cleanup (usblp);
	mutex_unlock (&usblp_mutex);
}

static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
{
	struct usblp *usblp = usb_get_intfdata (intf);

	/* we take no more IO */
	usblp->sleeping = 1;
	usblp_unlink_urbs(usblp);
#if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
	/* not strictly necessary, but just in case */
	wake_up(&usblp->wwait);
	wake_up(&usblp->rwait);
#endif

	return 0;
}

static int usblp_resume (struct usb_interface *intf)
{
	struct usblp *usblp = usb_get_intfdata (intf);
	int r;

	usblp->sleeping = 0;
	r = handle_bidir (usblp);

	return r;
}

static struct usb_device_id usblp_ids [] = {
	{ USB_DEVICE_INFO(7, 1, 1) },
	{ USB_DEVICE_INFO(7, 1, 2) },
	{ USB_DEVICE_INFO(7, 1, 3) },
	{ USB_INTERFACE_INFO(7, 1, 1) },
	{ USB_INTERFACE_INFO(7, 1, 2) },
	{ USB_INTERFACE_INFO(7, 1, 3) },
	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, usblp_ids);

static struct usb_driver usblp_driver = {
	.name =		"usblp",
	.probe =	usblp_probe,
	.disconnect =	usblp_disconnect,
	.suspend =	usblp_suspend,
	.resume =	usblp_resume,
	.id_table =	usblp_ids,
	.supports_autosuspend =	1,
};

static int __init usblp_init(void)
{
	return usb_register(&usblp_driver);
}

static void __exit usblp_exit(void)
{
	usb_deregister(&usblp_driver);
}

module_init(usblp_init);
module_exit(usblp_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
module_param(proto_bias, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
MODULE_LICENSE("GPL");