aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/digi_acceleport.c
blob: efbc4035410c63fce87d572dbcea18c8990ba30b (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
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
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
/*
*  Digi AccelePort USB-4 and USB-2 Serial Converters
*
*  Copyright 2000 by Digi International
*
*  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.
*
*  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
*  usb-serial driver.
*
*  Peter Berger (pberger@brimson.com)
*  Al Borchers (borchers@steinerpoint.com)
*/

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/wait.h>
#include <linux/usb/serial.h>

/* Defines */

#define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
#define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"

/* port output buffer length -- must be <= transfer buffer length - 2 */
/* so we can be sure to send the full buffer in one urb */
#define DIGI_OUT_BUF_SIZE		8

/* port input buffer length -- must be >= transfer buffer length - 3 */
/* so we can be sure to hold at least one full buffer from one urb */
#define DIGI_IN_BUF_SIZE		64

/* retry timeout while sleeping */
#define DIGI_RETRY_TIMEOUT		(HZ/10)

/* timeout while waiting for tty output to drain in close */
/* this delay is used twice in close, so the total delay could */
/* be twice this value */
#define DIGI_CLOSE_TIMEOUT		(5*HZ)


/* AccelePort USB Defines */

/* ids */
#define DIGI_VENDOR_ID			0x05c5
#define DIGI_2_ID			0x0002	/* USB-2 */
#define DIGI_4_ID			0x0004	/* USB-4 */

/* commands
 * "INB": can be used on the in-band endpoint
 * "OOB": can be used on the out-of-band endpoint
 */
#define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
#define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
#define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
#define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
#define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
#define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
#define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
#define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
#define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
#define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
#define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
#define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
#define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
#define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
#define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
#define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
#define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
#define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
#define DIGI_CMD_SEND_DATA			18	/* INB      */
#define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
#define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
#define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */

/* baud rates */
#define DIGI_BAUD_50				0
#define DIGI_BAUD_75				1
#define DIGI_BAUD_110				2
#define DIGI_BAUD_150				3
#define DIGI_BAUD_200				4
#define DIGI_BAUD_300				5
#define DIGI_BAUD_600				6
#define DIGI_BAUD_1200				7
#define DIGI_BAUD_1800				8
#define DIGI_BAUD_2400				9
#define DIGI_BAUD_4800				10
#define DIGI_BAUD_7200				11
#define DIGI_BAUD_9600				12
#define DIGI_BAUD_14400				13
#define DIGI_BAUD_19200				14
#define DIGI_BAUD_28800				15
#define DIGI_BAUD_38400				16
#define DIGI_BAUD_57600				17
#define DIGI_BAUD_76800				18
#define DIGI_BAUD_115200			19
#define DIGI_BAUD_153600			20
#define DIGI_BAUD_230400			21
#define DIGI_BAUD_460800			22

/* arguments */
#define DIGI_WORD_SIZE_5			0
#define DIGI_WORD_SIZE_6			1
#define DIGI_WORD_SIZE_7			2
#define DIGI_WORD_SIZE_8			3

#define DIGI_PARITY_NONE			0
#define DIGI_PARITY_ODD				1
#define DIGI_PARITY_EVEN			2
#define DIGI_PARITY_MARK			3
#define DIGI_PARITY_SPACE			4

#define DIGI_STOP_BITS_1			0
#define DIGI_STOP_BITS_2			1

#define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
#define DIGI_INPUT_FLOW_CONTROL_RTS		2
#define DIGI_INPUT_FLOW_CONTROL_DTR		4

#define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
#define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
#define DIGI_OUTPUT_FLOW_CONTROL_DSR		4

#define DIGI_DTR_INACTIVE			0
#define DIGI_DTR_ACTIVE				1
#define DIGI_DTR_INPUT_FLOW_CONTROL		2

#define DIGI_RTS_INACTIVE			0
#define DIGI_RTS_ACTIVE				1
#define DIGI_RTS_INPUT_FLOW_CONTROL		2
#define DIGI_RTS_TOGGLE				3

#define DIGI_FLUSH_TX				1
#define DIGI_FLUSH_RX				2
#define DIGI_RESUME_TX				4 /* clears xoff condition */

#define DIGI_TRANSMIT_NOT_IDLE			0
#define DIGI_TRANSMIT_IDLE			1

#define DIGI_DISABLE				0
#define DIGI_ENABLE				1

#define DIGI_DEASSERT				0
#define DIGI_ASSERT				1

/* in band status codes */
#define DIGI_OVERRUN_ERROR			4
#define DIGI_PARITY_ERROR			8
#define DIGI_FRAMING_ERROR			16
#define DIGI_BREAK_ERROR			32

/* out of band status */
#define DIGI_NO_ERROR				0
#define DIGI_BAD_FIRST_PARAMETER		1
#define DIGI_BAD_SECOND_PARAMETER		2
#define DIGI_INVALID_LINE			3
#define DIGI_INVALID_OPCODE			4

/* input signals */
#define DIGI_READ_INPUT_SIGNALS_SLOT		1
#define DIGI_READ_INPUT_SIGNALS_ERR		2
#define DIGI_READ_INPUT_SIGNALS_BUSY		4
#define DIGI_READ_INPUT_SIGNALS_PE		8
#define DIGI_READ_INPUT_SIGNALS_CTS		16
#define DIGI_READ_INPUT_SIGNALS_DSR		32
#define DIGI_READ_INPUT_SIGNALS_RI		64
#define DIGI_READ_INPUT_SIGNALS_DCD		128


/* Structures */

struct digi_serial {
	spinlock_t ds_serial_lock;
	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
	int ds_oob_port_num;			/* index of out-of-band port */
	int ds_device_started;
};

struct digi_port {
	spinlock_t dp_port_lock;
	int dp_port_num;
	int dp_out_buf_len;
	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
	int dp_write_urb_in_use;
	unsigned int dp_modem_signals;
	wait_queue_head_t dp_modem_change_wait;
	int dp_transmit_idle;
	wait_queue_head_t dp_transmit_idle_wait;
	int dp_throttled;
	int dp_throttle_restart;
	wait_queue_head_t dp_flush_wait;
	wait_queue_head_t dp_close_wait;	/* wait queue for close */
	struct work_struct dp_wakeup_work;
	struct usb_serial_port *dp_port;
};


/* Local Function Declarations */

static void digi_wakeup_write(struct usb_serial_port *port);
static void digi_wakeup_write_lock(struct work_struct *work);
static int digi_write_oob_command(struct usb_serial_port *port,
	unsigned char *buf, int count, int interruptible);
static int digi_write_inb_command(struct usb_serial_port *port,
	unsigned char *buf, int count, unsigned long timeout);
static int digi_set_modem_signals(struct usb_serial_port *port,
	unsigned int modem_signals, int interruptible);
static int digi_transmit_idle(struct usb_serial_port *port,
	unsigned long timeout);
static void digi_rx_throttle(struct tty_struct *tty);
static void digi_rx_unthrottle(struct tty_struct *tty);
static void digi_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios);
static void digi_break_ctl(struct tty_struct *tty, int break_state);
static int digi_tiocmget(struct tty_struct *tty);
static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
		unsigned int clear);
static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
		const unsigned char *buf, int count);
static void digi_write_bulk_callback(struct urb *urb);
static int digi_write_room(struct tty_struct *tty);
static int digi_chars_in_buffer(struct tty_struct *tty);
static int digi_open(struct tty_struct *tty, struct usb_serial_port *port);
static void digi_close(struct usb_serial_port *port);
static void digi_dtr_rts(struct usb_serial_port *port, int on);
static int digi_startup_device(struct usb_serial *serial);
static int digi_startup(struct usb_serial *serial);
static void digi_disconnect(struct usb_serial *serial);
static void digi_release(struct usb_serial *serial);
static int digi_port_probe(struct usb_serial_port *port);
static int digi_port_remove(struct usb_serial_port *port);
static void digi_read_bulk_callback(struct urb *urb);
static int digi_read_inb_callback(struct urb *urb);
static int digi_read_oob_callback(struct urb *urb);


static const struct usb_device_id id_table_combined[] = {
	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
	{ }						/* Terminating entry */
};

static const struct usb_device_id id_table_2[] = {
	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
	{ }						/* Terminating entry */
};

static const struct usb_device_id id_table_4[] = {
	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, id_table_combined);

/* device info needed for the Digi serial converter */

static struct usb_serial_driver digi_acceleport_2_device = {
	.driver = {
		.owner =		THIS_MODULE,
		.name =			"digi_2",
	},
	.description =			"Digi 2 port USB adapter",
	.id_table =			id_table_2,
	.num_ports =			3,
	.open =				digi_open,
	.close =			digi_close,
	.dtr_rts =			digi_dtr_rts,
	.write =			digi_write,
	.write_room =			digi_write_room,
	.write_bulk_callback = 		digi_write_bulk_callback,
	.read_bulk_callback =		digi_read_bulk_callback,
	.chars_in_buffer =		digi_chars_in_buffer,
	.throttle =			digi_rx_throttle,
	.unthrottle =			digi_rx_unthrottle,
	.set_termios =			digi_set_termios,
	.break_ctl =			digi_break_ctl,
	.tiocmget =			digi_tiocmget,
	.tiocmset =			digi_tiocmset,
	.attach =			digi_startup,
	.disconnect =			digi_disconnect,
	.release =			digi_release,
	.port_probe =			digi_port_probe,
	.port_remove =			digi_port_remove,
};

static struct usb_serial_driver digi_acceleport_4_device = {
	.driver = {
		.owner =		THIS_MODULE,
		.name =			"digi_4",
	},
	.description =			"Digi 4 port USB adapter",
	.id_table =			id_table_4,
	.num_ports =			4,
	.open =				digi_open,
	.close =			digi_close,
	.write =			digi_write,
	.write_room =			digi_write_room,
	.write_bulk_callback = 		digi_write_bulk_callback,
	.read_bulk_callback =		digi_read_bulk_callback,
	.chars_in_buffer =		digi_chars_in_buffer,
	.throttle =			digi_rx_throttle,
	.unthrottle =			digi_rx_unthrottle,
	.set_termios =			digi_set_termios,
	.break_ctl =			digi_break_ctl,
	.tiocmget =			digi_tiocmget,
	.tiocmset =			digi_tiocmset,
	.attach =			digi_startup,
	.disconnect =			digi_disconnect,
	.release =			digi_release,
	.port_probe =			digi_port_probe,
	.port_remove =			digi_port_remove,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&digi_acceleport_2_device, &digi_acceleport_4_device, NULL
};

/* Functions */

/*
 *  Cond Wait Interruptible Timeout Irqrestore
 *
 *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
 *  so that wake ups are not lost if they occur between the unlock
 *  and the sleep.  In other words, spin_unlock_irqrestore and
 *  interruptible_sleep_on_timeout are "atomic" with respect to
 *  wake ups.  This is used to implement condition variables.
 *
 *  interruptible_sleep_on_timeout is deprecated and has been replaced
 *  with the equivalent code.
 */

static long cond_wait_interruptible_timeout_irqrestore(
	wait_queue_head_t *q, long timeout,
	spinlock_t *lock, unsigned long flags)
__releases(lock)
{
	DEFINE_WAIT(wait);

	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
	spin_unlock_irqrestore(lock, flags);
	timeout = schedule_timeout(timeout);
	finish_wait(q, &wait);

	return timeout;
}


/*
 *  Digi Wakeup Write
 *
 *  Wake up port, line discipline, and tty processes sleeping
 *  on writes.
 */

static void digi_wakeup_write_lock(struct work_struct *work)
{
	struct digi_port *priv =
			container_of(work, struct digi_port, dp_wakeup_work);
	struct usb_serial_port *port = priv->dp_port;
	unsigned long flags;

	spin_lock_irqsave(&priv->dp_port_lock, flags);
	digi_wakeup_write(port);
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
}

static void digi_wakeup_write(struct usb_serial_port *port)
{
	struct tty_struct *tty = tty_port_tty_get(&port->port);
	if (tty) {
		tty_wakeup(tty);
		tty_kref_put(tty);
	}
}


/*
 *  Digi Write OOB Command
 *
 *  Write commands on the out of band port.  Commands are 4
 *  bytes each, multiple commands can be sent at once, and
 *  no command will be split across USB packets.  Returns 0
 *  if successful, -EINTR if interrupted while sleeping and
 *  the interruptible flag is true, or a negative error
 *  returned by usb_submit_urb.
 */

static int digi_write_oob_command(struct usb_serial_port *port,
	unsigned char *buf, int count, int interruptible)
{
	int ret = 0;
	int len;
	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
	unsigned long flags = 0;

	dev_dbg(&port->dev,
		"digi_write_oob_command: TOP: port=%d, count=%d\n",
		oob_priv->dp_port_num, count);

	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
	while (count > 0) {
		while (oob_priv->dp_write_urb_in_use) {
			cond_wait_interruptible_timeout_irqrestore(
				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
				&oob_priv->dp_port_lock, flags);
			if (interruptible && signal_pending(current))
				return -EINTR;
			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
		}

		/* len must be a multiple of 4, so commands are not split */
		len = min(count, oob_port->bulk_out_size);
		if (len > 4)
			len &= ~3;
		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
		oob_port->write_urb->transfer_buffer_length = len;
		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
		if (ret == 0) {
			oob_priv->dp_write_urb_in_use = 1;
			count -= len;
			buf += len;
		}
	}
	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
	if (ret)
		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
			__func__, ret);
	return ret;

}


/*
 *  Digi Write In Band Command
 *
 *  Write commands on the given port.  Commands are 4
 *  bytes each, multiple commands can be sent at once, and
 *  no command will be split across USB packets.  If timeout
 *  is non-zero, write in band command will return after
 *  waiting unsuccessfully for the URB status to clear for
 *  timeout ticks.  Returns 0 if successful, or a negative
 *  error returned by digi_write.
 */

static int digi_write_inb_command(struct usb_serial_port *port,
	unsigned char *buf, int count, unsigned long timeout)
{
	int ret = 0;
	int len;
	struct digi_port *priv = usb_get_serial_port_data(port);
	unsigned char *data = port->write_urb->transfer_buffer;
	unsigned long flags = 0;

	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
		priv->dp_port_num, count);

	if (timeout)
		timeout += jiffies;
	else
		timeout = ULONG_MAX;

	spin_lock_irqsave(&priv->dp_port_lock, flags);
	while (count > 0 && ret == 0) {
		while (priv->dp_write_urb_in_use &&
		       time_before(jiffies, timeout)) {
			cond_wait_interruptible_timeout_irqrestore(
				&port->write_wait, DIGI_RETRY_TIMEOUT,
				&priv->dp_port_lock, flags);
			if (signal_pending(current))
				return -EINTR;
			spin_lock_irqsave(&priv->dp_port_lock, flags);
		}

		/* len must be a multiple of 4 and small enough to */
		/* guarantee the write will send buffered data first, */
		/* so commands are in order with data and not split */
		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
		if (len > 4)
			len &= ~3;

		/* write any buffered data first */
		if (priv->dp_out_buf_len > 0) {
			data[0] = DIGI_CMD_SEND_DATA;
			data[1] = priv->dp_out_buf_len;
			memcpy(data + 2, priv->dp_out_buf,
				priv->dp_out_buf_len);
			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
			port->write_urb->transfer_buffer_length
				= priv->dp_out_buf_len + 2 + len;
		} else {
			memcpy(data, buf, len);
			port->write_urb->transfer_buffer_length = len;
		}

		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
		if (ret == 0) {
			priv->dp_write_urb_in_use = 1;
			priv->dp_out_buf_len = 0;
			count -= len;
			buf += len;
		}

	}
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);

	if (ret)
		dev_err(&port->dev,
			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
			__func__, ret, priv->dp_port_num);
	return ret;
}


/*
 *  Digi Set Modem Signals
 *
 *  Sets or clears DTR and RTS on the port, according to the
 *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
 *  for the modem_signals argument.  Returns 0 if successful,
 *  -EINTR if interrupted while sleeping, or a non-zero error
 *  returned by usb_submit_urb.
 */

static int digi_set_modem_signals(struct usb_serial_port *port,
	unsigned int modem_signals, int interruptible)
{

	int ret;
	struct digi_port *port_priv = usb_get_serial_port_data(port);
	struct usb_serial_port *oob_port = (struct usb_serial_port *) ((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
	unsigned char *data = oob_port->write_urb->transfer_buffer;
	unsigned long flags = 0;


	dev_dbg(&port->dev,
		"digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x\n",
		port_priv->dp_port_num, modem_signals);

	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
	spin_lock(&port_priv->dp_port_lock);

	while (oob_priv->dp_write_urb_in_use) {
		spin_unlock(&port_priv->dp_port_lock);
		cond_wait_interruptible_timeout_irqrestore(
			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
			&oob_priv->dp_port_lock, flags);
		if (interruptible && signal_pending(current))
			return -EINTR;
		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
		spin_lock(&port_priv->dp_port_lock);
	}
	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
	data[1] = port_priv->dp_port_num;
	data[2] = (modem_signals & TIOCM_DTR) ?
					DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
	data[3] = 0;
	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
	data[5] = port_priv->dp_port_num;
	data[6] = (modem_signals & TIOCM_RTS) ?
					DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
	data[7] = 0;

	oob_port->write_urb->transfer_buffer_length = 8;

	ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
	if (ret == 0) {
		oob_priv->dp_write_urb_in_use = 1;
		port_priv->dp_modem_signals =
			(port_priv->dp_modem_signals&~(TIOCM_DTR|TIOCM_RTS))
			| (modem_signals&(TIOCM_DTR|TIOCM_RTS));
	}
	spin_unlock(&port_priv->dp_port_lock);
	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
	if (ret)
		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
			__func__, ret);
	return ret;
}

/*
 *  Digi Transmit Idle
 *
 *  Digi transmit idle waits, up to timeout ticks, for the transmitter
 *  to go idle.  It returns 0 if successful or a negative error.
 *
 *  There are race conditions here if more than one process is calling
 *  digi_transmit_idle on the same port at the same time.  However, this
 *  is only called from close, and only one process can be in close on a
 *  port at a time, so its ok.
 */

static int digi_transmit_idle(struct usb_serial_port *port,
	unsigned long timeout)
{
	int ret;
	unsigned char buf[2];
	struct digi_port *priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;

	spin_lock_irqsave(&priv->dp_port_lock, flags);
	priv->dp_transmit_idle = 0;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);

	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
	buf[1] = 0;

	timeout += jiffies;

	ret = digi_write_inb_command(port, buf, 2, timeout - jiffies);
	if (ret != 0)
		return ret;

	spin_lock_irqsave(&priv->dp_port_lock, flags);

	while (time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
		cond_wait_interruptible_timeout_irqrestore(
			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
			&priv->dp_port_lock, flags);
		if (signal_pending(current))
			return -EINTR;
		spin_lock_irqsave(&priv->dp_port_lock, flags);
	}
	priv->dp_transmit_idle = 0;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	return 0;

}


static void digi_rx_throttle(struct tty_struct *tty)
{
	unsigned long flags;
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);

	/* stop receiving characters by not resubmitting the read urb */
	spin_lock_irqsave(&priv->dp_port_lock, flags);
	priv->dp_throttled = 1;
	priv->dp_throttle_restart = 0;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
}


static void digi_rx_unthrottle(struct tty_struct *tty)
{
	int ret = 0;
	unsigned long flags;
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);

	spin_lock_irqsave(&priv->dp_port_lock, flags);

	/* restart read chain */
	if (priv->dp_throttle_restart)
		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);

	/* turn throttle off */
	priv->dp_throttled = 0;
	priv->dp_throttle_restart = 0;

	spin_unlock_irqrestore(&priv->dp_port_lock, flags);

	if (ret)
		dev_err(&port->dev,
			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
			__func__, ret, priv->dp_port_num);
}


static void digi_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
	struct digi_port *priv = usb_get_serial_port_data(port);
	struct device *dev = &port->dev;
	unsigned int iflag = tty->termios.c_iflag;
	unsigned int cflag = tty->termios.c_cflag;
	unsigned int old_iflag = old_termios->c_iflag;
	unsigned int old_cflag = old_termios->c_cflag;
	unsigned char buf[32];
	unsigned int modem_signals;
	int arg, ret;
	int i = 0;
	speed_t baud;

	dev_dbg(dev,
		"digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x\n",
		priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);

	/* set baud rate */
	baud = tty_get_baud_rate(tty);
	if (baud != tty_termios_baud_rate(old_termios)) {
		arg = -1;

		/* reassert DTR and (maybe) RTS on transition from B0 */
		if ((old_cflag&CBAUD) == B0) {
			/* don't set RTS if using hardware flow control */
			/* and throttling input */
			modem_signals = TIOCM_DTR;
			if (!(tty->termios.c_cflag & CRTSCTS) ||
			    !test_bit(TTY_THROTTLED, &tty->flags))
				modem_signals |= TIOCM_RTS;
			digi_set_modem_signals(port, modem_signals, 1);
		}
		switch (baud) {
		/* drop DTR and RTS on transition to B0 */
		case 0: digi_set_modem_signals(port, 0, 1); break;
		case 50: arg = DIGI_BAUD_50; break;
		case 75: arg = DIGI_BAUD_75; break;
		case 110: arg = DIGI_BAUD_110; break;
		case 150: arg = DIGI_BAUD_150; break;
		case 200: arg = DIGI_BAUD_200; break;
		case 300: arg = DIGI_BAUD_300; break;
		case 600: arg = DIGI_BAUD_600; break;
		case 1200: arg = DIGI_BAUD_1200; break;
		case 1800: arg = DIGI_BAUD_1800; break;
		case 2400: arg = DIGI_BAUD_2400; break;
		case 4800: arg = DIGI_BAUD_4800; break;
		case 9600: arg = DIGI_BAUD_9600; break;
		case 19200: arg = DIGI_BAUD_19200; break;
		case 38400: arg = DIGI_BAUD_38400; break;
		case 57600: arg = DIGI_BAUD_57600; break;
		case 115200: arg = DIGI_BAUD_115200; break;
		case 230400: arg = DIGI_BAUD_230400; break;
		case 460800: arg = DIGI_BAUD_460800; break;
		default:
			arg = DIGI_BAUD_9600;
			baud = 9600;
			break;
		}
		if (arg != -1) {
			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
			buf[i++] = priv->dp_port_num;
			buf[i++] = arg;
			buf[i++] = 0;
		}
	}
	/* set parity */
	tty->termios.c_cflag &= ~CMSPAR;

	if ((cflag&(PARENB|PARODD)) != (old_cflag&(PARENB|PARODD))) {
		if (cflag&PARENB) {
			if (cflag&PARODD)
				arg = DIGI_PARITY_ODD;
			else
				arg = DIGI_PARITY_EVEN;
		} else {
			arg = DIGI_PARITY_NONE;
		}
		buf[i++] = DIGI_CMD_SET_PARITY;
		buf[i++] = priv->dp_port_num;
		buf[i++] = arg;
		buf[i++] = 0;
	}
	/* set word size */
	if ((cflag&CSIZE) != (old_cflag&CSIZE)) {
		arg = -1;
		switch (cflag&CSIZE) {
		case CS5: arg = DIGI_WORD_SIZE_5; break;
		case CS6: arg = DIGI_WORD_SIZE_6; break;
		case CS7: arg = DIGI_WORD_SIZE_7; break;
		case CS8: arg = DIGI_WORD_SIZE_8; break;
		default:
			dev_dbg(dev,
				"digi_set_termios: can't handle word size %d\n",
				(cflag&CSIZE));
			break;
		}

		if (arg != -1) {
			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
			buf[i++] = priv->dp_port_num;
			buf[i++] = arg;
			buf[i++] = 0;
		}

	}

	/* set stop bits */
	if ((cflag&CSTOPB) != (old_cflag&CSTOPB)) {

		if ((cflag&CSTOPB))
			arg = DIGI_STOP_BITS_2;
		else
			arg = DIGI_STOP_BITS_1;

		buf[i++] = DIGI_CMD_SET_STOP_BITS;
		buf[i++] = priv->dp_port_num;
		buf[i++] = arg;
		buf[i++] = 0;

	}

	/* set input flow control */
	if ((iflag&IXOFF) != (old_iflag&IXOFF)
	    || (cflag&CRTSCTS) != (old_cflag&CRTSCTS)) {
		arg = 0;
		if (iflag&IXOFF)
			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
		else
			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;

		if (cflag&CRTSCTS) {
			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;

			/* On USB-4 it is necessary to assert RTS prior */
			/* to selecting RTS input flow control.  */
			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
			buf[i++] = priv->dp_port_num;
			buf[i++] = DIGI_RTS_ACTIVE;
			buf[i++] = 0;

		} else {
			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
		}
		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
		buf[i++] = priv->dp_port_num;
		buf[i++] = arg;
		buf[i++] = 0;
	}

	/* set output flow control */
	if ((iflag & IXON) != (old_iflag & IXON)
	    || (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
		arg = 0;
		if (iflag & IXON)
			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
		else
			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;

		if (cflag & CRTSCTS) {
			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
		} else {
			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
			tty->hw_stopped = 0;
		}

		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
		buf[i++] = priv->dp_port_num;
		buf[i++] = arg;
		buf[i++] = 0;
	}

	/* set receive enable/disable */
	if ((cflag & CREAD) != (old_cflag & CREAD)) {
		if (cflag & CREAD)
			arg = DIGI_ENABLE;
		else
			arg = DIGI_DISABLE;

		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
		buf[i++] = priv->dp_port_num;
		buf[i++] = arg;
		buf[i++] = 0;
	}
	ret = digi_write_oob_command(port, buf, i, 1);
	if (ret != 0)
		dev_dbg(dev, "digi_set_termios: write oob failed, ret=%d\n", ret);
	tty_encode_baud_rate(tty, baud, baud);
}


static void digi_break_ctl(struct tty_struct *tty, int break_state)
{
	struct usb_serial_port *port = tty->driver_data;
	unsigned char buf[4];

	buf[0] = DIGI_CMD_BREAK_CONTROL;
	buf[1] = 2;				/* length */
	buf[2] = break_state ? 1 : 0;
	buf[3] = 0;				/* pad */
	digi_write_inb_command(port, buf, 4, 0);
}


static int digi_tiocmget(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);
	unsigned int val;
	unsigned long flags;

	spin_lock_irqsave(&priv->dp_port_lock, flags);
	val = priv->dp_modem_signals;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	return val;
}


static int digi_tiocmset(struct tty_struct *tty,
					unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);
	unsigned int val;
	unsigned long flags;

	spin_lock_irqsave(&priv->dp_port_lock, flags);
	val = (priv->dp_modem_signals & ~clear) | set;
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	return digi_set_modem_signals(port, val, 1);
}


static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
					const unsigned char *buf, int count)
{

	int ret, data_len, new_len;
	struct digi_port *priv = usb_get_serial_port_data(port);
	unsigned char *data = port->write_urb->transfer_buffer;
	unsigned long flags = 0;

	dev_dbg(&port->dev,
		"digi_write: TOP: port=%d, count=%d, in_interrupt=%ld\n",
		priv->dp_port_num, count, in_interrupt());

	/* copy user data (which can sleep) before getting spin lock */
	count = min(count, port->bulk_out_size-2);
	count = min(64, count);

	/* be sure only one write proceeds at a time */
	/* there are races on the port private buffer */
	spin_lock_irqsave(&priv->dp_port_lock, flags);

	/* wait for urb status clear to submit another urb */
	if (priv->dp_write_urb_in_use) {
		/* buffer data if count is 1 (probably put_char) if possible */
		if (count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE) {
			priv->dp_out_buf[priv->dp_out_buf_len++] = *buf;
			new_len = 1;
		} else {
			new_len = 0;
		}
		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
		return new_len;
	}

	/* allow space for any buffered data and for new data, up to */
	/* transfer buffer size - 2 (for command and length bytes) */
	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
	data_len = new_len + priv->dp_out_buf_len;

	if (data_len == 0) {
		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
		return 0;
	}

	port->write_urb->transfer_buffer_length = data_len+2;

	*data++ = DIGI_CMD_SEND_DATA;
	*data++ = data_len;

	/* copy in buffered data first */
	memcpy(data, priv->dp_out_buf, priv->dp_out_buf_len);
	data += priv->dp_out_buf_len;

	/* copy in new data */
	memcpy(data, buf, new_len);

	ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
	if (ret == 0) {
		priv->dp_write_urb_in_use = 1;
		ret = new_len;
		priv->dp_out_buf_len = 0;
	}

	/* return length of new data written, or error */
	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	if (ret < 0)
		dev_err_console(port,
			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
			__func__, ret, priv->dp_port_num);
	dev_dbg(&port->dev, "digi_write: returning %d\n", ret);
	return ret;

}

static void digi_write_bulk_callback(struct urb *urb)
{

	struct usb_serial_port *port = urb->context;
	struct usb_serial *serial;
	struct digi_port *priv;
	struct digi_serial *serial_priv;
	int ret = 0;
	int status = urb->status;

	/* port and serial sanity check */
	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
		pr_err("%s: port or port->private is NULL, status=%d\n",
			__func__, status);
		return;
	}
	serial = port->serial;
	if (serial == NULL || (serial_priv = usb_get_serial_data(serial)) == NULL) {
		dev_err(&port->dev,
			"%s: serial or serial->private is NULL, status=%d\n",
			__func__, status);
		return;
	}

	/* handle oob callback */
	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
		dev_dbg(&port->dev, "digi_write_bulk_callback: oob callback\n");
		spin_lock(&priv->dp_port_lock);
		priv->dp_write_urb_in_use = 0;
		wake_up_interruptible(&port->write_wait);
		spin_unlock(&priv->dp_port_lock);
		return;
	}

	/* try to send any buffered data on this port */
	spin_lock(&priv->dp_port_lock);
	priv->dp_write_urb_in_use = 0;
	if (priv->dp_out_buf_len > 0) {
		*((unsigned char *)(port->write_urb->transfer_buffer))
			= (unsigned char)DIGI_CMD_SEND_DATA;
		*((unsigned char *)(port->write_urb->transfer_buffer) + 1)
			= (unsigned char)priv->dp_out_buf_len;
		port->write_urb->transfer_buffer_length =
						priv->dp_out_buf_len + 2;
		memcpy(port->write_urb->transfer_buffer + 2, priv->dp_out_buf,
			priv->dp_out_buf_len);
		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
		if (ret == 0) {
			priv->dp_write_urb_in_use = 1;
			priv->dp_out_buf_len = 0;
		}
	}
	/* wake up processes sleeping on writes immediately */
	digi_wakeup_write(port);
	/* also queue up a wakeup at scheduler time, in case we */
	/* lost the race in write_chan(). */
	schedule_work(&priv->dp_wakeup_work);

	spin_unlock(&priv->dp_port_lock);
	if (ret && ret != -EPERM)
		dev_err_console(port,
			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
			__func__, ret, priv->dp_port_num);
}

static int digi_write_room(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);
	int room;
	unsigned long flags = 0;

	spin_lock_irqsave(&priv->dp_port_lock, flags);

	if (priv->dp_write_urb_in_use)
		room = 0;
	else
		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;

	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
	dev_dbg(&port->dev, "digi_write_room: port=%d, room=%d\n", priv->dp_port_num, room);
	return room;

}

static int digi_chars_in_buffer(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct digi_port *priv = usb_get_serial_port_data(port);

	if (priv->dp_write_urb_in_use) {
		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
			priv->dp_port_num, port->bulk_out_size - 2);
		/* return(port->bulk_out_size - 2); */
		return 256;
	} else {
		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
			priv->dp_port_num, priv->dp_out_buf_len);
		return priv->dp_out_buf_len;
	}

}

static void digi_dtr_rts(struct usb_serial_port *port, int on)
{
	/* Adjust DTR and RTS */
	digi_set_modem_signals(port, on * (TIOCM_DTR|TIOCM_RTS), 1);
}

static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	int ret;
	unsigned char buf[32];
	struct digi_port *priv = usb_get_serial_port_data(port);
	struct ktermios not_termios;

	/* be sure the device is started up */
	if (digi_startup_device(port->serial) != 0)
		return -ENXIO;

	/* read modem signals automatically whenever they change */
	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
	buf[1] = priv->dp_port_num;
	buf[2] = DIGI_ENABLE;
	buf[3] = 0;

	/* flush fifos */
	buf[4] = DIGI_CMD_IFLUSH_FIFO;
	buf[5] = priv->dp_port_num;
	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
	buf[7] = 0;

	ret = digi_write_oob_command(port, buf, 8, 1);
	if (ret != 0)
		dev_dbg(&port->dev, "digi_open: write oob failed, ret=%d\n", ret);

	/* set termios settings */
	if (tty) {
		not_termios.c_cflag = ~tty->termios.c_cflag;
		not_termios.c_iflag = ~tty->termios.c_iflag;
		digi_set_termios(tty, port, &not_termios);
	}
	return 0;
}


static void digi_close(struct usb_serial_port *port)
{
	DEFINE_WAIT(wait);
	int ret;
	unsigned char buf[32];
	struct digi_port *priv = usb_get_serial_port_data(port);

	mutex_lock(&port->serial->disc_mutex);
	/* if disconnected, just clear flags */
	if (port->serial->disconnected)
		goto exit;

	if (port->serial->dev) {
		/* FIXME: Transmit idle belongs in the wait_unti_sent path */
		digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);

		/* disable input flow control */
		buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
		buf[1] = priv->dp_port_num;
		buf[2] = DIGI_DISABLE;
		buf[3] = 0;

		/* disable output flow control */
		buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
		buf[5] = priv->dp_port_num;
		buf[6] = DIGI_DISABLE;
		buf[7] = 0;

		/* disable reading modem signals automatically */
		buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
		buf[9] = priv->dp_port_num;
		buf[10] = DIGI_DISABLE;
		buf[11] = 0;

		/* disable receive */
		buf[12] = DIGI_CMD_RECEIVE_ENABLE;
		buf[13] = priv->dp_port_num;
		buf[14] = DIGI_DISABLE;
		buf[15] = 0;

		/* flush fifos */
		buf[16] = DIGI_CMD_IFLUSH_FIFO;
		buf[17] = priv->dp_port_num;
		buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
		buf[19] = 0;

		ret = digi_write_oob_command(port, buf, 20, 0);
		if (ret != 0)
			dev_dbg(&port->dev, "digi_close: write oob failed, ret=%d\n", ret);

		/* wait for final commands on oob port to complete */
		prepare_to_wait(&priv->dp_flush_wait, &wait,
							TASK_INTERRUPTIBLE);
		schedule_timeout(DIGI_CLOSE_TIMEOUT);
		finish_wait(&priv->dp_flush_wait, &wait);

		/* shutdown any outstanding bulk writes */
		usb_kill_urb(port->write_urb);
	}
exit:
	spin_lock_irq(&priv->dp_port_lock);
	priv->dp_write_urb_in_use = 0;
	wake_up_interruptible(&priv->dp_close_wait);
	spin_unlock_irq(&priv->dp_port_lock);
	mutex_unlock(&port->serial->disc_mutex);
}


/*
 *  Digi Startup Device
 *
 *  Starts reads on all ports.  Must be called AFTER startup, with
 *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
 */

static int digi_startup_device(struct usb_serial *serial)
{
	int i, ret = 0;
	struct digi_serial *serial_priv = usb_get_serial_data(serial);
	struct usb_serial_port *port;

	/* be sure this happens exactly once */
	spin_lock(&serial_priv->ds_serial_lock);
	if (serial_priv->ds_device_started) {
		spin_unlock(&serial_priv->ds_serial_lock);
		return 0;
	}
	serial_priv->ds_device_started = 1;
	spin_unlock(&serial_priv->ds_serial_lock);

	/* start reading from each bulk in endpoint for the device */
	/* set USB_DISABLE_SPD flag for write bulk urbs */
	for (i = 0; i < serial->type->num_ports + 1; i++) {
		port = serial->port[i];
		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
		if (ret != 0) {
			dev_err(&port->dev,
				"%s: usb_submit_urb failed, ret=%d, port=%d\n",
				__func__, ret, i);
			break;
		}
	}
	return ret;
}

static int digi_port_init(struct usb_serial_port *port, unsigned port_num)
{
	struct digi_port *priv;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	spin_lock_init(&priv->dp_port_lock);
	priv->dp_port_num = port_num;
	init_waitqueue_head(&priv->dp_modem_change_wait);
	init_waitqueue_head(&priv->dp_transmit_idle_wait);
	init_waitqueue_head(&priv->dp_flush_wait);
	init_waitqueue_head(&priv->dp_close_wait);
	INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
	priv->dp_port = port;

	init_waitqueue_head(&port->write_wait);

	usb_set_serial_port_data(port, priv);

	return 0;
}

static int digi_startup(struct usb_serial *serial)
{
	struct digi_serial *serial_priv;
	int ret;

	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
	if (!serial_priv)
		return -ENOMEM;

	spin_lock_init(&serial_priv->ds_serial_lock);
	serial_priv->ds_oob_port_num = serial->type->num_ports;
	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];

	ret = digi_port_init(serial_priv->ds_oob_port,
						serial_priv->ds_oob_port_num);
	if (ret) {
		kfree(serial_priv);
		return ret;
	}

	usb_set_serial_data(serial, serial_priv);

	return 0;
}


static void digi_disconnect(struct usb_serial *serial)
{
	int i;

	/* stop reads and writes on all ports */
	for (i = 0; i < serial->type->num_ports + 1; i++) {
		usb_kill_urb(serial->port[i]->read_urb);
		usb_kill_urb(serial->port[i]->write_urb);
	}
}


static void digi_release(struct usb_serial *serial)
{
	struct digi_serial *serial_priv;
	struct digi_port *priv;

	serial_priv = usb_get_serial_data(serial);

	priv = usb_get_serial_port_data(serial_priv->ds_oob_port);
	kfree(priv);

	kfree(serial_priv);
}

static int digi_port_probe(struct usb_serial_port *port)
{
	unsigned port_num;

	port_num = port->number - port->serial->minor;

	return digi_port_init(port, port_num);
}

static int digi_port_remove(struct usb_serial_port *port)
{
	struct digi_port *priv;

	priv = usb_get_serial_port_data(port);
	kfree(priv);

	return 0;
}

static void digi_read_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	struct digi_port *priv;
	struct digi_serial *serial_priv;
	int ret;
	int status = urb->status;

	/* port sanity check, do not resubmit if port is not valid */
	if (port == NULL)
		return;
	priv = usb_get_serial_port_data(port);
	if (priv == NULL) {
		dev_err(&port->dev, "%s: port->private is NULL, status=%d\n",
			__func__, status);
		return;
	}
	if (port->serial == NULL ||
		(serial_priv = usb_get_serial_data(port->serial)) == NULL) {
		dev_err(&port->dev, "%s: serial is bad or serial->private "
			"is NULL, status=%d\n", __func__, status);
		return;
	}

	/* do not resubmit urb if it has any status error */
	if (status) {
		dev_err(&port->dev,
			"%s: nonzero read bulk status: status=%d, port=%d\n",
			__func__, status, priv->dp_port_num);
		return;
	}

	/* handle oob or inb callback, do not resubmit if error */
	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
		if (digi_read_oob_callback(urb) != 0)
			return;
	} else {
		if (digi_read_inb_callback(urb) != 0)
			return;
	}

	/* continue read */
	ret = usb_submit_urb(urb, GFP_ATOMIC);
	if (ret != 0 && ret != -EPERM) {
		dev_err(&port->dev,
			"%s: failed resubmitting urb, ret=%d, port=%d\n",
			__func__, ret, priv->dp_port_num);
	}

}

/*
 *  Digi Read INB Callback
 *
 *  Digi Read INB Callback handles reads on the in band ports, sending
 *  the data on to the tty subsystem.  When called we know port and
 *  port->private are not NULL and port->serial has been validated.
 *  It returns 0 if successful, 1 if successful but the port is
 *  throttled, and -1 if the sanity checks failed.
 */

static int digi_read_inb_callback(struct urb *urb)
{

	struct usb_serial_port *port = urb->context;
	struct tty_struct *tty;
	struct digi_port *priv = usb_get_serial_port_data(port);
	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
	int len = ((unsigned char *)urb->transfer_buffer)[1];
	int port_status = ((unsigned char *)urb->transfer_buffer)[2];
	unsigned char *data = ((unsigned char *)urb->transfer_buffer) + 3;
	int flag, throttled;
	int status = urb->status;

	/* do not process callbacks on closed ports */
	/* but do continue the read chain */
	if (urb->status == -ENOENT)
		return 0;

	/* short/multiple packet check */
	if (urb->actual_length != len + 2) {
		dev_err(&port->dev, "%s: INCOMPLETE OR MULTIPLE PACKET, "
			"status=%d, port=%d, opcode=%d, len=%d, "
			"actual_length=%d, status=%d\n", __func__, status,
			priv->dp_port_num, opcode, len, urb->actual_length,
			port_status);
		return -1;
	}

	tty = tty_port_tty_get(&port->port);
	spin_lock(&priv->dp_port_lock);

	/* check for throttle; if set, do not resubmit read urb */
	/* indicate the read chain needs to be restarted on unthrottle */
	throttled = priv->dp_throttled;
	if (throttled)
		priv->dp_throttle_restart = 1;

	/* receive data */
	if (tty && opcode == DIGI_CMD_RECEIVE_DATA) {
		/* get flag from port_status */
		flag = 0;

		/* overrun is special, not associated with a char */
		if (port_status & DIGI_OVERRUN_ERROR)
			tty_insert_flip_char(tty, 0, TTY_OVERRUN);

		/* break takes precedence over parity, */
		/* which takes precedence over framing errors */
		if (port_status & DIGI_BREAK_ERROR)
			flag = TTY_BREAK;
		else if (port_status & DIGI_PARITY_ERROR)
			flag = TTY_PARITY;
		else if (port_status & DIGI_FRAMING_ERROR)
			flag = TTY_FRAME;

		/* data length is len-1 (one byte of len is port_status) */
		--len;
		if (len > 0) {
			tty_insert_flip_string_fixed_flag(&port->port, data,
					flag, len);
			tty_flip_buffer_push(tty);
		}
	}
	spin_unlock(&priv->dp_port_lock);
	tty_kref_put(tty);

	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
		dev_dbg(&port->dev, "%s: got RECEIVE_DISABLE\n", __func__);
	else if (opcode != DIGI_CMD_RECEIVE_DATA)
		dev_dbg(&port->dev, "%s: unknown opcode: %d\n", __func__, opcode);

	return throttled ? 1 : 0;

}


/*
 *  Digi Read OOB Callback
 *
 *  Digi Read OOB Callback handles reads on the out of band port.
 *  When called we know port and port->private are not NULL and
 *  the port->serial is valid.  It returns 0 if successful, and
 *  -1 if the sanity checks failed.
 */

static int digi_read_oob_callback(struct urb *urb)
{

	struct usb_serial_port *port = urb->context;
	struct usb_serial *serial = port->serial;
	struct tty_struct *tty;
	struct digi_port *priv = usb_get_serial_port_data(port);
	int opcode, line, status, val;
	int i;
	unsigned int rts;

	/* handle each oob command */
	for (i = 0; i < urb->actual_length - 3;) {
		opcode = ((unsigned char *)urb->transfer_buffer)[i++];
		line = ((unsigned char *)urb->transfer_buffer)[i++];
		status = ((unsigned char *)urb->transfer_buffer)[i++];
		val = ((unsigned char *)urb->transfer_buffer)[i++];

		dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
			opcode, line, status, val);

		if (status != 0 || line >= serial->type->num_ports)
			continue;

		port = serial->port[line];

		priv = usb_get_serial_port_data(port);
		if (priv == NULL)
			return -1;

		tty = tty_port_tty_get(&port->port);

		rts = 0;
		if (tty)
			rts = tty->termios.c_cflag & CRTSCTS;
		
		if (tty && opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
			spin_lock(&priv->dp_port_lock);
			/* convert from digi flags to termiox flags */
			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
				priv->dp_modem_signals |= TIOCM_CTS;
				/* port must be open to use tty struct */
				if (rts) {
					tty->hw_stopped = 0;
					digi_wakeup_write(port);
				}
			} else {
				priv->dp_modem_signals &= ~TIOCM_CTS;
				/* port must be open to use tty struct */
				if (rts)
					tty->hw_stopped = 1;
			}
			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
				priv->dp_modem_signals |= TIOCM_DSR;
			else
				priv->dp_modem_signals &= ~TIOCM_DSR;
			if (val & DIGI_READ_INPUT_SIGNALS_RI)
				priv->dp_modem_signals |= TIOCM_RI;
			else
				priv->dp_modem_signals &= ~TIOCM_RI;
			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
				priv->dp_modem_signals |= TIOCM_CD;
			else
				priv->dp_modem_signals &= ~TIOCM_CD;

			wake_up_interruptible(&priv->dp_modem_change_wait);
			spin_unlock(&priv->dp_port_lock);
		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
			spin_lock(&priv->dp_port_lock);
			priv->dp_transmit_idle = 1;
			wake_up_interruptible(&priv->dp_transmit_idle_wait);
			spin_unlock(&priv->dp_port_lock);
		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
			wake_up_interruptible(&priv->dp_flush_wait);
		}
		tty_kref_put(tty);
	}
	return 0;

}

module_usb_serial_driver(serial_drivers, id_table_combined);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");