summaryrefslogtreecommitdiffstats
path: root/drivers/tty/amiserial.c
blob: 8330fd809a05f330ab17f82da1c968e8bcf12b9f (plain) (blame)
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
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
// SPDX-License-Identifier: GPL-2.0
/*
 * Serial driver for the amiga builtin port.
 *
 * This code was created by taking serial.c version 4.30 from kernel
 * release 2.3.22, replacing all hardware related stuff with the
 * corresponding amiga hardware actions, and removing all irrelevant
 * code. As a consequence, it uses many of the constants and names
 * associated with the registers and bits of 16550 compatible UARTS -
 * but only to keep track of status, etc in the state variables. It
 * was done this was to make it easier to keep the code in line with
 * (non hardware specific) changes to serial.c.
 *
 * The port is registered with the tty driver as minor device 64, and
 * therefore other ports should should only use 65 upwards.
 *
 * Richard Lucock 28/12/99
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 
 * 		1998, 1999  Theodore Ts'o
 *
 */

/*
 * Serial driver configuration section.  Here are the various options:
 *
 * SERIAL_PARANOIA_CHECK
 * 		Check the magic number for the async_structure where
 * 		ever possible.
 */

#include <linux/delay.h>

#undef SERIAL_PARANOIA_CHECK

/* Set of debugging defines */

#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT

/* Sanity checks */

#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
 tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
#else
#define DBG_CNT(s)
#endif

/*
 * End of serial driver configuration section.
 */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
static char *serial_version = "4.30";

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/circ_buf.h>
#include <linux/console.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>

#include <asm/setup.h>


#include <asm/irq.h>

#include <asm/amigahw.h>
#include <asm/amigaints.h>

struct serial_state {
	struct tty_port		tport;
	struct circ_buf		xmit;
	struct async_icount	icount;

	unsigned long		port;
	int			baud_base;
	int			xmit_fifo_size;
	int			custom_divisor;
	int			read_status_mask;
	int			ignore_status_mask;
	int			timeout;
	int			quot;
	int			IER; 	/* Interrupt Enable Register */
	int			MCR; 	/* Modem control register */
	int			x_char;	/* xon/xoff character */
};

#define custom amiga_custom
static char *serial_name = "Amiga-builtin serial driver";

static struct tty_driver *serial_driver;

/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256

static unsigned char current_ctl_bits;

static void change_speed(struct tty_struct *tty, struct serial_state *info,
		struct ktermios *old);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);


static struct serial_state rs_table[1];

#define NR_PORTS ARRAY_SIZE(rs_table)

#include <linux/uaccess.h>

#define serial_isroot()	(capable(CAP_SYS_ADMIN))


static inline int serial_paranoia_check(struct serial_state *info,
					char *name, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
	static const char *badmagic =
		"Warning: bad magic number for serial struct (%s) in %s\n";
	static const char *badinfo =
		"Warning: null async_struct for (%s) in %s\n";

	if (!info) {
		printk(badinfo, name, routine);
		return 1;
	}
	if (info->magic != SERIAL_MAGIC) {
		printk(badmagic, name, routine);
		return 1;
	}
#endif
	return 0;
}

/* some serial hardware definitions */
#define SDR_OVRUN   (1<<15)
#define SDR_RBF     (1<<14)
#define SDR_TBE     (1<<13)
#define SDR_TSRE    (1<<12)

#define SERPER_PARENB    (1<<15)

#define AC_SETCLR   (1<<15)
#define AC_UARTBRK  (1<<11)

#define SER_DTR     (1<<7)
#define SER_RTS     (1<<6)
#define SER_DCD     (1<<5)
#define SER_CTS     (1<<4)
#define SER_DSR     (1<<3)

static __inline__ void rtsdtr_ctrl(int bits)
{
    ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
}

/*
 * ------------------------------------------------------------
 * rs_stop() and rs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void rs_stop(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_stop"))
		return;

	local_irq_save(flags);
	if (info->IER & UART_IER_THRI) {
		info->IER &= ~UART_IER_THRI;
		/* disable Tx interrupt and remove any pending interrupts */
		custom.intena = IF_TBE;
		mb();
		custom.intreq = IF_TBE;
		mb();
	}
	local_irq_restore(flags);
}

static void rs_start(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_start"))
		return;

	local_irq_save(flags);
	if (info->xmit.head != info->xmit.tail
	    && info->xmit.buf
	    && !(info->IER & UART_IER_THRI)) {
		info->IER |= UART_IER_THRI;
		custom.intena = IF_SETCLR | IF_TBE;
		mb();
		/* set a pending Tx Interrupt, transmitter should restart now */
		custom.intreq = IF_SETCLR | IF_TBE;
		mb();
	}
	local_irq_restore(flags);
}

/*
 * ----------------------------------------------------------------------
 *
 * Here starts the interrupt handling routines.  All of the following
 * subroutines are declared as inline and are folded into
 * rs_interrupt().  They were separated out for readability's sake.
 *
 * Note: rs_interrupt() is a "fast" interrupt, which means that it
 * runs with interrupts turned off.  People who may want to modify
 * rs_interrupt() should try to keep the interrupt handler as fast as
 * possible.  After you are done making modifications, it is not a bad
 * idea to do:
 * 
 * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
 *
 * and look at the resulting assemble code in serial.s.
 *
 * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
 * -----------------------------------------------------------------------
 */

static void receive_chars(struct serial_state *info)
{
        int status;
	int serdatr;
	unsigned char ch, flag;
	struct	async_icount *icount;
	int oe = 0;

	icount = &info->icount;

	status = UART_LSR_DR; /* We obviously have a character! */
	serdatr = custom.serdatr;
	mb();
	custom.intreq = IF_RBF;
	mb();

	if((serdatr & 0x1ff) == 0)
	    status |= UART_LSR_BI;
	if(serdatr & SDR_OVRUN)
	    status |= UART_LSR_OE;

	ch = serdatr & 0xff;
	icount->rx++;

#ifdef SERIAL_DEBUG_INTR
	printk("DR%02x:%02x...", ch, status);
#endif
	flag = TTY_NORMAL;

	/*
	 * We don't handle parity or frame errors - but I have left
	 * the code in, since I'm not sure that the errors can't be
	 * detected.
	 */

	if (status & (UART_LSR_BI | UART_LSR_PE |
		      UART_LSR_FE | UART_LSR_OE)) {
	  /*
	   * For statistics only
	   */
	  if (status & UART_LSR_BI) {
	    status &= ~(UART_LSR_FE | UART_LSR_PE);
	    icount->brk++;
	  } else if (status & UART_LSR_PE)
	    icount->parity++;
	  else if (status & UART_LSR_FE)
	    icount->frame++;
	  if (status & UART_LSR_OE)
	    icount->overrun++;

	  /*
	   * Now check to see if character should be
	   * ignored, and mask off conditions which
	   * should be ignored.
	   */
	  if (status & info->ignore_status_mask)
	    goto out;

	  status &= info->read_status_mask;

	  if (status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
	    printk("handling break....");
#endif
	    flag = TTY_BREAK;
	    if (info->tport.flags & ASYNC_SAK)
	      do_SAK(info->tport.tty);
	  } else if (status & UART_LSR_PE)
	    flag = TTY_PARITY;
	  else if (status & UART_LSR_FE)
	    flag = TTY_FRAME;
	  if (status & UART_LSR_OE) {
	    /*
	     * Overrun is special, since it's
	     * reported immediately, and doesn't
	     * affect the current character
	     */
	     oe = 1;
	  }
	}
	tty_insert_flip_char(&info->tport, ch, flag);
	if (oe == 1)
		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
	tty_flip_buffer_push(&info->tport);
out:
	return;
}

static void transmit_chars(struct serial_state *info)
{
	custom.intreq = IF_TBE;
	mb();
	if (info->x_char) {
	        custom.serdat = info->x_char | 0x100;
		mb();
		info->icount.tx++;
		info->x_char = 0;
		return;
	}
	if (info->xmit.head == info->xmit.tail
	    || info->tport.tty->stopped
	    || info->tport.tty->hw_stopped) {
		info->IER &= ~UART_IER_THRI;
	        custom.intena = IF_TBE;
		mb();
		return;
	}

	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
	mb();
	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
	info->icount.tx++;

	if (CIRC_CNT(info->xmit.head,
		     info->xmit.tail,
		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
		tty_wakeup(info->tport.tty);

#ifdef SERIAL_DEBUG_INTR
	printk("THRE...");
#endif
	if (info->xmit.head == info->xmit.tail) {
	        custom.intena = IF_TBE;
		mb();
		info->IER &= ~UART_IER_THRI;
	}
}

static void check_modem_status(struct serial_state *info)
{
	struct tty_port *port = &info->tport;
	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
	unsigned char dstatus;
	struct	async_icount *icount;

	/* Determine bits that have changed */
	dstatus = status ^ current_ctl_bits;
	current_ctl_bits = status;

	if (dstatus) {
		icount = &info->icount;
		/* update input line counters */
		if (dstatus & SER_DSR)
			icount->dsr++;
		if (dstatus & SER_DCD) {
			icount->dcd++;
		}
		if (dstatus & SER_CTS)
			icount->cts++;
		wake_up_interruptible(&port->delta_msr_wait);
	}

	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
		printk("ttyS%d CD now %s...", info->line,
		       (!(status & SER_DCD)) ? "on" : "off");
#endif
		if (!(status & SER_DCD))
			wake_up_interruptible(&port->open_wait);
		else {
#ifdef SERIAL_DEBUG_OPEN
			printk("doing serial hangup...");
#endif
			if (port->tty)
				tty_hangup(port->tty);
		}
	}
	if (tty_port_cts_enabled(port)) {
		if (port->tty->hw_stopped) {
			if (!(status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
				printk("CTS tx start...");
#endif
				port->tty->hw_stopped = 0;
				info->IER |= UART_IER_THRI;
				custom.intena = IF_SETCLR | IF_TBE;
				mb();
				/* set a pending Tx Interrupt, transmitter should restart now */
				custom.intreq = IF_SETCLR | IF_TBE;
				mb();
				tty_wakeup(port->tty);
				return;
			}
		} else {
			if ((status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
				printk("CTS tx stop...");
#endif
				port->tty->hw_stopped = 1;
				info->IER &= ~UART_IER_THRI;
				/* disable Tx interrupt and remove any pending interrupts */
				custom.intena = IF_TBE;
				mb();
				custom.intreq = IF_TBE;
				mb();
			}
		}
	}
}

static irqreturn_t ser_vbl_int( int irq, void *data)
{
        /* vbl is just a periodic interrupt we tie into to update modem status */
	struct serial_state *info = data;
	/*
	 * TBD - is it better to unregister from this interrupt or to
	 * ignore it if MSI is clear ?
	 */
	if(info->IER & UART_IER_MSI)
	  check_modem_status(info);
	return IRQ_HANDLED;
}

static irqreturn_t ser_rx_int(int irq, void *dev_id)
{
	struct serial_state *info = dev_id;

#ifdef SERIAL_DEBUG_INTR
	printk("ser_rx_int...");
#endif

	if (!info->tport.tty)
		return IRQ_NONE;

	receive_chars(info);
#ifdef SERIAL_DEBUG_INTR
	printk("end.\n");
#endif
	return IRQ_HANDLED;
}

static irqreturn_t ser_tx_int(int irq, void *dev_id)
{
	struct serial_state *info = dev_id;

	if (custom.serdatr & SDR_TBE) {
#ifdef SERIAL_DEBUG_INTR
	  printk("ser_tx_int...");
#endif

	  if (!info->tport.tty)
		return IRQ_NONE;

	  transmit_chars(info);
#ifdef SERIAL_DEBUG_INTR
	  printk("end.\n");
#endif
	}
	return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

/*
 * ---------------------------------------------------------------
 * Low level utility subroutines for the serial driver:  routines to
 * figure out the appropriate timeout for an interrupt chain, routines
 * to initialize and startup a serial port, and routines to shutdown a
 * serial port.  Useful stuff like that.
 * ---------------------------------------------------------------
 */

static int startup(struct tty_struct *tty, struct serial_state *info)
{
	struct tty_port *port = &info->tport;
	unsigned long flags;
	int	retval=0;
	unsigned long page;

	page = get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	local_irq_save(flags);

	if (tty_port_initialized(port)) {
		free_page(page);
		goto errout;
	}

	if (info->xmit.buf)
		free_page(page);
	else
		info->xmit.buf = (unsigned char *) page;

#ifdef SERIAL_DEBUG_OPEN
	printk("starting up ttys%d ...", info->line);
#endif

	/* Clear anything in the input buffer */

	custom.intreq = IF_RBF;
	mb();

	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
	if (retval) {
	  if (serial_isroot()) {
	      set_bit(TTY_IO_ERROR, &tty->flags);
	    retval = 0;
	  }
	  goto errout;
	}

	/* enable both Rx and Tx interrupts */
	custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
	mb();
	info->IER = UART_IER_MSI;

	/* remember current state of the DCD and CTS bits */
	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);

	info->MCR = 0;
	if (C_BAUD(tty))
	  info->MCR = SER_DTR | SER_RTS;
	rtsdtr_ctrl(info->MCR);

	clear_bit(TTY_IO_ERROR, &tty->flags);
	info->xmit.head = info->xmit.tail = 0;

	/*
	 * and set the speed of the serial port
	 */
	change_speed(tty, info, NULL);

	tty_port_set_initialized(port, 1);
	local_irq_restore(flags);
	return 0;

errout:
	local_irq_restore(flags);
	return retval;
}

/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(struct tty_struct *tty, struct serial_state *info)
{
	unsigned long	flags;
	struct serial_state *state;

	if (!tty_port_initialized(&info->tport))
		return;

	state = info;

#ifdef SERIAL_DEBUG_OPEN
	printk("Shutting down serial port %d ....\n", info->line);
#endif

	local_irq_save(flags); /* Disable interrupts */

	/*
	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
	 * here so the queue might never be waken up
	 */
	wake_up_interruptible(&info->tport.delta_msr_wait);

	/*
	 * Free the IRQ, if necessary
	 */
	free_irq(IRQ_AMIGA_VERTB, info);

	if (info->xmit.buf) {
		free_page((unsigned long) info->xmit.buf);
		info->xmit.buf = NULL;
	}

	info->IER = 0;
	custom.intena = IF_RBF | IF_TBE;
	mb();

	/* disable break condition */
	custom.adkcon = AC_UARTBRK;
	mb();

	if (C_HUPCL(tty))
		info->MCR &= ~(SER_DTR|SER_RTS);
	rtsdtr_ctrl(info->MCR);

	set_bit(TTY_IO_ERROR, &tty->flags);

	tty_port_set_initialized(&info->tport, 0);
	local_irq_restore(flags);
}


/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static void change_speed(struct tty_struct *tty, struct serial_state *info,
			 struct ktermios *old_termios)
{
	struct tty_port *port = &info->tport;
	int	quot = 0, baud_base, baud;
	unsigned cflag, cval = 0;
	int	bits;
	unsigned long	flags;

	cflag = tty->termios.c_cflag;

	/* Byte size is always 8 bits plus parity bit if requested */

	cval = 3; bits = 10;
	if (cflag & CSTOPB) {
		cval |= 0x04;
		bits++;
	}
	if (cflag & PARENB) {
		cval |= UART_LCR_PARITY;
		bits++;
	}
	if (!(cflag & PARODD))
		cval |= UART_LCR_EPAR;
#ifdef CMSPAR
	if (cflag & CMSPAR)
		cval |= UART_LCR_SPAR;
#endif

	/* Determine divisor based on baud rate */
	baud = tty_get_baud_rate(tty);
	if (!baud)
		baud = 9600;	/* B0 transition handled in rs_set_termios */
	baud_base = info->baud_base;
	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
		quot = info->custom_divisor;
	else {
		if (baud == 134)
			/* Special case since 134 is really 134.5 */
			quot = (2*baud_base / 269);
		else if (baud)
			quot = baud_base / baud;
	}
	/* If the quotient is zero refuse the change */
	if (!quot && old_termios) {
		/* FIXME: Will need updating for new tty in the end */
		tty->termios.c_cflag &= ~CBAUD;
		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
		baud = tty_get_baud_rate(tty);
		if (!baud)
			baud = 9600;
		if (baud == 38400 &&
		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
			quot = info->custom_divisor;
		else {
			if (baud == 134)
				/* Special case since 134 is really 134.5 */
				quot = (2*baud_base / 269);
			else if (baud)
				quot = baud_base / baud;
		}
	}
	/* As a last resort, if the quotient is zero, default to 9600 bps */
	if (!quot)
		quot = baud_base / 9600;
	info->quot = quot;
	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
	info->timeout += HZ/50;		/* Add .02 seconds of slop */

	/* CTS flow control flag and modem status interrupts */
	info->IER &= ~UART_IER_MSI;
	if (port->flags & ASYNC_HARDPPS_CD)
		info->IER |= UART_IER_MSI;
	tty_port_set_cts_flow(port, cflag & CRTSCTS);
	if (cflag & CRTSCTS)
		info->IER |= UART_IER_MSI;
	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
	if (~cflag & CLOCAL)
		info->IER |= UART_IER_MSI;
	/* TBD:
	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
	 */

	/*
	 * Set up parity check flag
	 */

	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
	if (I_INPCK(tty))
		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (I_BRKINT(tty) || I_PARMRK(tty))
		info->read_status_mask |= UART_LSR_BI;

	/*
	 * Characters to ignore
	 */
	info->ignore_status_mask = 0;
	if (I_IGNPAR(tty))
		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
	if (I_IGNBRK(tty)) {
		info->ignore_status_mask |= UART_LSR_BI;
		/*
		 * If we're ignore parity and break indicators, ignore 
		 * overruns too.  (For real raw support).
		 */
		if (I_IGNPAR(tty))
			info->ignore_status_mask |= UART_LSR_OE;
	}
	/*
	 * !!! ignore all characters if CREAD is not set
	 */
	if ((cflag & CREAD) == 0)
		info->ignore_status_mask |= UART_LSR_DR;
	local_irq_save(flags);

	{
	  short serper;

	/* Set up the baud rate */
	  serper = quot - 1;

	/* Enable or disable parity bit */

	if(cval & UART_LCR_PARITY)
	  serper |= (SERPER_PARENB);

	custom.serper = serper;
	mb();
	}

	local_irq_restore(flags);
}

static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct serial_state *info;
	unsigned long flags;

	info = tty->driver_data;

	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
		return 0;

	if (!info->xmit.buf)
		return 0;

	local_irq_save(flags);
	if (CIRC_SPACE(info->xmit.head,
		       info->xmit.tail,
		       SERIAL_XMIT_SIZE) == 0) {
		local_irq_restore(flags);
		return 0;
	}

	info->xmit.buf[info->xmit.head++] = ch;
	info->xmit.head &= SERIAL_XMIT_SIZE-1;
	local_irq_restore(flags);
	return 1;
}

static void rs_flush_chars(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
		return;

	if (info->xmit.head == info->xmit.tail
	    || tty->stopped
	    || tty->hw_stopped
	    || !info->xmit.buf)
		return;

	local_irq_save(flags);
	info->IER |= UART_IER_THRI;
	custom.intena = IF_SETCLR | IF_TBE;
	mb();
	/* set a pending Tx Interrupt, transmitter should restart now */
	custom.intreq = IF_SETCLR | IF_TBE;
	mb();
	local_irq_restore(flags);
}

static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
{
	int	c, ret = 0;
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_write"))
		return 0;

	if (!info->xmit.buf)
		return 0;

	local_irq_save(flags);
	while (1) {
		c = CIRC_SPACE_TO_END(info->xmit.head,
				      info->xmit.tail,
				      SERIAL_XMIT_SIZE);
		if (count < c)
			c = count;
		if (c <= 0) {
			break;
		}
		memcpy(info->xmit.buf + info->xmit.head, buf, c);
		info->xmit.head = ((info->xmit.head + c) &
				   (SERIAL_XMIT_SIZE-1));
		buf += c;
		count -= c;
		ret += c;
	}
	local_irq_restore(flags);

	if (info->xmit.head != info->xmit.tail
	    && !tty->stopped
	    && !tty->hw_stopped
	    && !(info->IER & UART_IER_THRI)) {
		info->IER |= UART_IER_THRI;
		local_irq_disable();
		custom.intena = IF_SETCLR | IF_TBE;
		mb();
		/* set a pending Tx Interrupt, transmitter should restart now */
		custom.intreq = IF_SETCLR | IF_TBE;
		mb();
		local_irq_restore(flags);
	}
	return ret;
}

static int rs_write_room(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
		return 0;
	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static int rs_chars_in_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
		return 0;
	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static void rs_flush_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
		return;
	local_irq_save(flags);
	info->xmit.head = info->xmit.tail = 0;
	local_irq_restore(flags);
	tty_wakeup(tty);
}

/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
	struct serial_state *info = tty->driver_data;
        unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_send_xchar"))
		return;

	info->x_char = ch;
	if (ch) {
		/* Make sure transmit interrupts are on */

	        /* Check this ! */
	        local_irq_save(flags);
		if(!(custom.intenar & IF_TBE)) {
		    custom.intena = IF_SETCLR | IF_TBE;
		    mb();
		    /* set a pending Tx Interrupt, transmitter should restart now */
		    custom.intreq = IF_SETCLR | IF_TBE;
		    mb();
		}
		local_irq_restore(flags);

		info->IER |= UART_IER_THRI;
	}
}

/*
 * ------------------------------------------------------------
 * rs_throttle()
 * 
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
	printk("throttle %s ....\n", tty_name(tty));
#endif

	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
		return;

	if (I_IXOFF(tty))
		rs_send_xchar(tty, STOP_CHAR(tty));

	if (C_CRTSCTS(tty))
		info->MCR &= ~SER_RTS;

	local_irq_save(flags);
	rtsdtr_ctrl(info->MCR);
	local_irq_restore(flags);
}

static void rs_unthrottle(struct tty_struct * tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
	printk("unthrottle %s ....\n", tty_name(tty));
#endif

	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
		return;

	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			rs_send_xchar(tty, START_CHAR(tty));
	}
	if (C_CRTSCTS(tty))
		info->MCR |= SER_RTS;
	local_irq_save(flags);
	rtsdtr_ctrl(info->MCR);
	local_irq_restore(flags);
}

/*
 * ------------------------------------------------------------
 * rs_ioctl() and friends
 * ------------------------------------------------------------
 */

static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
	struct serial_state *state = tty->driver_data;

	tty_lock(tty);
	ss->line = tty->index;
	ss->port = state->port;
	ss->flags = state->tport.flags;
	ss->xmit_fifo_size = state->xmit_fifo_size;
	ss->baud_base = state->baud_base;
	ss->close_delay = state->tport.close_delay;
	ss->closing_wait = state->tport.closing_wait;
	ss->custom_divisor = state->custom_divisor;
	tty_unlock(tty);
	return 0;
}

static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
	struct serial_state *state = tty->driver_data;
	struct tty_port *port = &state->tport;
	bool change_spd;
	int 			retval = 0;

	tty_lock(tty);
	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
		ss->custom_divisor != state->custom_divisor;
	if (ss->irq || ss->port != state->port ||
			ss->xmit_fifo_size != state->xmit_fifo_size) {
		tty_unlock(tty);
		return -EINVAL;
	}
  
	if (!serial_isroot()) {
		if ((ss->baud_base != state->baud_base) ||
		    (ss->close_delay != port->close_delay) ||
		    (ss->xmit_fifo_size != state->xmit_fifo_size) ||
		    ((ss->flags & ~ASYNC_USR_MASK) !=
		     (port->flags & ~ASYNC_USR_MASK))) {
			tty_unlock(tty);
			return -EPERM;
		}
		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
			       (ss->flags & ASYNC_USR_MASK));
		state->custom_divisor = ss->custom_divisor;
		goto check_and_exit;
	}

	if (ss->baud_base < 9600) {
		tty_unlock(tty);
		return -EINVAL;
	}

	/*
	 * OK, past this point, all the error checking has been done.
	 * At this point, we start making changes.....
	 */

	state->baud_base = ss->baud_base;
	port->flags = ((port->flags & ~ASYNC_FLAGS) |
			(ss->flags & ASYNC_FLAGS));
	state->custom_divisor = ss->custom_divisor;
	port->close_delay = ss->close_delay * HZ/100;
	port->closing_wait = ss->closing_wait * HZ/100;
	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

check_and_exit:
	if (tty_port_initialized(port)) {
		if (change_spd) {
			/* warn about deprecation unless clearing */
			if (ss->flags & ASYNC_SPD_MASK)
				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
			change_speed(tty, state, NULL);
		}
	} else
		retval = startup(tty, state);
	tty_unlock(tty);
	return retval;
}

/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 * 	    is emptied.  On bus types like RS485, the transmitter must
 * 	    release the bus after transmitting. This must be done when
 * 	    the transmit shift register is empty, not be done when the
 * 	    transmit holding register is empty.  This functionality
 * 	    allows an RS485 driver to be written in user space. 
 */
static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
{
	unsigned char status;
	unsigned int result;
	unsigned long flags;

	local_irq_save(flags);
	status = custom.serdatr;
	mb();
	local_irq_restore(flags);
	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
	if (copy_to_user(value, &result, sizeof(int)))
		return -EFAULT;
	return 0;
}


static int rs_tiocmget(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned char control, status;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
		return -ENODEV;
	if (tty_io_error(tty))
		return -EIO;

	control = info->MCR;
	local_irq_save(flags);
	status = ciab.pra;
	local_irq_restore(flags);
	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
		| ((control & SER_DTR) ? TIOCM_DTR : 0)
		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
}

static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
						unsigned int clear)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
		return -ENODEV;
	if (tty_io_error(tty))
		return -EIO;

	local_irq_save(flags);
	if (set & TIOCM_RTS)
		info->MCR |= SER_RTS;
	if (set & TIOCM_DTR)
		info->MCR |= SER_DTR;
	if (clear & TIOCM_RTS)
		info->MCR &= ~SER_RTS;
	if (clear & TIOCM_DTR)
		info->MCR &= ~SER_DTR;
	rtsdtr_ctrl(info->MCR);
	local_irq_restore(flags);
	return 0;
}

/*
 * rs_break() --- routine which turns the break handling on or off
 */
static int rs_break(struct tty_struct *tty, int break_state)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, "rs_break"))
		return -EINVAL;

	local_irq_save(flags);
	if (break_state == -1)
	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
	else
	  custom.adkcon = AC_UARTBRK;
	mb();
	local_irq_restore(flags);
	return 0;
}

/*
 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
 * Return: write counters to the user passed counter struct
 * NB: both 1->0 and 0->1 transitions are counted except for
 *     RI where only 0->1 is counted.
 */
static int rs_get_icount(struct tty_struct *tty,
				struct serial_icounter_struct *icount)
{
	struct serial_state *info = tty->driver_data;
	struct async_icount cnow;
	unsigned long flags;

	local_irq_save(flags);
	cnow = info->icount;
	local_irq_restore(flags);
	icount->cts = cnow.cts;
	icount->dsr = cnow.dsr;
	icount->rng = cnow.rng;
	icount->dcd = cnow.dcd;
	icount->rx = cnow.rx;
	icount->tx = cnow.tx;
	icount->frame = cnow.frame;
	icount->overrun = cnow.overrun;
	icount->parity = cnow.parity;
	icount->brk = cnow.brk;
	icount->buf_overrun = cnow.buf_overrun;

	return 0;
}

static int rs_ioctl(struct tty_struct *tty,
		    unsigned int cmd, unsigned long arg)
{
	struct serial_state *info = tty->driver_data;
	struct async_icount cprev, cnow;	/* kernel counter temps */
	void __user *argp = (void __user *)arg;
	unsigned long flags;
	DEFINE_WAIT(wait);
	int ret;

	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
		return -ENODEV;

	if ((cmd != TIOCSERCONFIG) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty_io_error(tty))
		    return -EIO;
	}

	switch (cmd) {
		case TIOCSERCONFIG:
			return 0;

		case TIOCSERGETLSR: /* Get line status register */
			return get_lsr_info(info, argp);

		/*
		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
		 * - mask passed in arg for lines of interest
 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
		 * Caller should use TIOCGICOUNT to see which one it was
		 */
		case TIOCMIWAIT:
			local_irq_save(flags);
			/* note the counters on entry */
			cprev = info->icount;
			local_irq_restore(flags);
			while (1) {
				prepare_to_wait(&info->tport.delta_msr_wait,
						&wait, TASK_INTERRUPTIBLE);
				local_irq_save(flags);
				cnow = info->icount; /* atomic copy */
				local_irq_restore(flags);
				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
					ret = -EIO; /* no change => error */
					break;
				}
				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
					ret = 0;
					break;
				}
				schedule();
				/* see if a signal did it */
				if (signal_pending(current)) {
					ret = -ERESTARTSYS;
					break;
				}
				cprev = cnow;
			}
			finish_wait(&info->tport.delta_msr_wait, &wait);
			return ret;

		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;
	unsigned int cflag = tty->termios.c_cflag;

	change_speed(tty, info, old_termios);

	/* Handle transition to B0 status */
	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
		info->MCR &= ~(SER_DTR|SER_RTS);
		local_irq_save(flags);
		rtsdtr_ctrl(info->MCR);
		local_irq_restore(flags);
	}

	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
		info->MCR |= SER_DTR;
		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
			info->MCR |= SER_RTS;
		local_irq_save(flags);
		rtsdtr_ctrl(info->MCR);
		local_irq_restore(flags);
	}

	/* Handle turning off CRTSCTS */
	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
		tty->hw_stopped = 0;
		rs_start(tty);
	}

#if 0
	/*
	 * No need to wake up processes in open wait, since they
	 * sample the CLOCAL flag once, and don't recheck it.
	 * XXX  It's not clear whether the current behavior is correct
	 * or not.  Hence, this may change.....
	 */
	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
		wake_up_interruptible(&info->open_wait);
#endif
}

/*
 * ------------------------------------------------------------
 * rs_close()
 * 
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * async structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 * ------------------------------------------------------------
 */
static void rs_close(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *state = tty->driver_data;
	struct tty_port *port = &state->tport;

	if (serial_paranoia_check(state, tty->name, "rs_close"))
		return;

	if (tty_port_close_start(port, tty, filp) == 0)
		return;

	/*
	 * At this point we stop accepting input.  To do this, we
	 * disable the receive line status interrupts, and tell the
	 * interrupt driver to stop checking the data ready bit in the
	 * line status register.
	 */
	state->read_status_mask &= ~UART_LSR_DR;
	if (tty_port_initialized(port)) {
	        /* disable receive interrupts */
	        custom.intena = IF_RBF;
		mb();
		/* clear any pending receive interrupt */
		custom.intreq = IF_RBF;
		mb();

		/*
		 * Before we drop DTR, make sure the UART transmitter
		 * has completely drained; this is especially
		 * important if there is a transmit FIFO!
		 */
		rs_wait_until_sent(tty, state->timeout);
	}
	shutdown(tty, state);
	rs_flush_buffer(tty);
		
	tty_ldisc_flush(tty);
	port->tty = NULL;

	tty_port_close_end(port, tty);
}

/*
 * rs_wait_until_sent() --- wait until the transmitter is empty
 */
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
	struct serial_state *info = tty->driver_data;
	unsigned long orig_jiffies, char_time;
	int lsr;

	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
		return;

	if (info->xmit_fifo_size == 0)
		return; /* Just in case.... */

	orig_jiffies = jiffies;

	/*
	 * Set the check interval to be 1/5 of the estimated time to
	 * send a single character, and make it at least 1.  The check
	 * interval should also be less than the timeout.
	 * 
	 * Note: we have to use pretty tight timings here to satisfy
	 * the NIST-PCTS.
	 */
	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
	char_time = char_time / 5;
	if (char_time == 0)
		char_time = 1;
	if (timeout)
	  char_time = min_t(unsigned long, char_time, timeout);
	/*
	 * If the transmitter hasn't cleared in twice the approximate
	 * amount of time to send the entire FIFO, it probably won't
	 * ever clear.  This assumes the UART isn't doing flow
	 * control, which is currently the case.  Hence, if it ever
	 * takes longer than info->timeout, this is probably due to a
	 * UART bug of some kind.  So, we clamp the timeout parameter at
	 * 2*info->timeout.
	 */
	if (!timeout || timeout > 2*info->timeout)
		timeout = 2*info->timeout;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
	printk("jiff=%lu...", jiffies);
#endif
	while(!((lsr = custom.serdatr) & SDR_TSRE)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
#endif
		msleep_interruptible(jiffies_to_msecs(char_time));
		if (signal_pending(current))
			break;
		if (timeout && time_after(jiffies, orig_jiffies + timeout))
			break;
	}
	__set_current_state(TASK_RUNNING);

#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
#endif
}

/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void rs_hangup(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
		return;

	rs_flush_buffer(tty);
	shutdown(tty, info);
	info->tport.count = 0;
	tty_port_set_active(&info->tport, 0);
	info->tport.tty = NULL;
	wake_up_interruptible(&info->tport.open_wait);
}

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int rs_open(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *info = rs_table + tty->index;
	struct tty_port *port = &info->tport;
	int retval;

	port->count++;
	port->tty = tty;
	tty->driver_data = info;
	tty->port = port;
	if (serial_paranoia_check(info, tty->name, "rs_open"))
		return -ENODEV;

	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	retval = startup(tty, info);
	if (retval) {
		return retval;
	}

	return tty_port_block_til_ready(port, tty, filp);
}

/*
 * /proc fs routines....
 */

static inline void line_info(struct seq_file *m, int line,
		struct serial_state *state)
{
	char	stat_buf[30], control, status;
	unsigned long flags;

	seq_printf(m, "%d: uart:amiga_builtin", line);

	local_irq_save(flags);
	status = ciab.pra;
	control = tty_port_initialized(&state->tport) ? state->MCR : status;
	local_irq_restore(flags);

	stat_buf[0] = 0;
	stat_buf[1] = 0;
	if(!(control & SER_RTS))
		strcat(stat_buf, "|RTS");
	if(!(status & SER_CTS))
		strcat(stat_buf, "|CTS");
	if(!(control & SER_DTR))
		strcat(stat_buf, "|DTR");
	if(!(status & SER_DSR))
		strcat(stat_buf, "|DSR");
	if(!(status & SER_DCD))
		strcat(stat_buf, "|CD");

	if (state->quot)
		seq_printf(m, " baud:%d", state->baud_base / state->quot);

	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);

	if (state->icount.frame)
		seq_printf(m, " fe:%d", state->icount.frame);

	if (state->icount.parity)
		seq_printf(m, " pe:%d", state->icount.parity);

	if (state->icount.brk)
		seq_printf(m, " brk:%d", state->icount.brk);

	if (state->icount.overrun)
		seq_printf(m, " oe:%d", state->icount.overrun);

	/*
	 * Last thing is the RS-232 status lines
	 */
	seq_printf(m, " %s\n", stat_buf+1);
}

static int rs_proc_show(struct seq_file *m, void *v)
{
	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
	line_info(m, 0, &rs_table[0]);
	return 0;
}

/*
 * ---------------------------------------------------------------------
 * rs_init() and friends
 *
 * rs_init() is called at boot-time to initialize the serial driver.
 * ---------------------------------------------------------------------
 */

/*
 * This routine prints out the appropriate serial driver version
 * number, and identifies which options were configured into this
 * driver.
 */
static void show_serial_version(void)
{
 	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
}


static const struct tty_operations serial_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.put_char = rs_put_char,
	.flush_chars = rs_flush_chars,
	.write_room = rs_write_room,
	.chars_in_buffer = rs_chars_in_buffer,
	.flush_buffer = rs_flush_buffer,
	.ioctl = rs_ioctl,
	.throttle = rs_throttle,
	.unthrottle = rs_unthrottle,
	.set_termios = rs_set_termios,
	.stop = rs_stop,
	.start = rs_start,
	.hangup = rs_hangup,
	.break_ctl = rs_break,
	.send_xchar = rs_send_xchar,
	.wait_until_sent = rs_wait_until_sent,
	.tiocmget = rs_tiocmget,
	.tiocmset = rs_tiocmset,
	.get_icount = rs_get_icount,
	.set_serial = set_serial_info,
	.get_serial = get_serial_info,
	.proc_show = rs_proc_show,
};

static int amiga_carrier_raised(struct tty_port *port)
{
	return !(ciab.pra & SER_DCD);
}

static void amiga_dtr_rts(struct tty_port *port, int raise)
{
	struct serial_state *info = container_of(port, struct serial_state,
			tport);
	unsigned long flags;

	if (raise)
		info->MCR |= SER_DTR|SER_RTS;
	else
		info->MCR &= ~(SER_DTR|SER_RTS);

	local_irq_save(flags);
	rtsdtr_ctrl(info->MCR);
	local_irq_restore(flags);
}

static const struct tty_port_operations amiga_port_ops = {
	.carrier_raised = amiga_carrier_raised,
	.dtr_rts = amiga_dtr_rts,
};

/*
 * The serial driver boot-time initialization code!
 */
static int __init amiga_serial_probe(struct platform_device *pdev)
{
	unsigned long flags;
	struct serial_state * state;
	int error;

	serial_driver = alloc_tty_driver(NR_PORTS);
	if (!serial_driver)
		return -ENOMEM;

	show_serial_version();

	/* Initialize the tty_driver structure */

	serial_driver->driver_name = "amiserial";
	serial_driver->name = "ttyS";
	serial_driver->major = TTY_MAJOR;
	serial_driver->minor_start = 64;
	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	serial_driver->subtype = SERIAL_TYPE_NORMAL;
	serial_driver->init_termios = tty_std_termios;
	serial_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	serial_driver->flags = TTY_DRIVER_REAL_RAW;
	tty_set_operations(serial_driver, &serial_ops);

	state = rs_table;
	state->port = (int)&custom.serdatr; /* Just to give it a value */
	state->custom_divisor = 0;
	state->icount.cts = state->icount.dsr = 
	  state->icount.rng = state->icount.dcd = 0;
	state->icount.rx = state->icount.tx = 0;
	state->icount.frame = state->icount.parity = 0;
	state->icount.overrun = state->icount.brk = 0;
	tty_port_init(&state->tport);
	state->tport.ops = &amiga_port_ops;
	tty_port_link_device(&state->tport, serial_driver, 0);

	error = tty_register_driver(serial_driver);
	if (error)
		goto fail_put_tty_driver;

	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");

	/* Hardware set up */

	state->baud_base = amiga_colorclock;
	state->xmit_fifo_size = 1;

	/* set ISRs, and then disable the rx interrupts */
	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
	if (error)
		goto fail_unregister;

	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
			    "serial RX", state);
	if (error)
		goto fail_free_irq;

	local_irq_save(flags);

	/* turn off Rx and Tx interrupts */
	custom.intena = IF_RBF | IF_TBE;
	mb();

	/* clear any pending interrupt */
	custom.intreq = IF_RBF | IF_TBE;
	mb();

	local_irq_restore(flags);

	/*
	 * set the appropriate directions for the modem control flags,
	 * and clear RTS and DTR
	 */
	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */

	platform_set_drvdata(pdev, state);

	return 0;

fail_free_irq:
	free_irq(IRQ_AMIGA_TBE, state);
fail_unregister:
	tty_unregister_driver(serial_driver);
fail_put_tty_driver:
	tty_port_destroy(&state->tport);
	put_tty_driver(serial_driver);
	return error;
}

static int __exit amiga_serial_remove(struct platform_device *pdev)
{
	int error;
	struct serial_state *state = platform_get_drvdata(pdev);

	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
	error = tty_unregister_driver(serial_driver);
	if (error)
		printk("SERIAL: failed to unregister serial driver (%d)\n",
		       error);
	put_tty_driver(serial_driver);
	tty_port_destroy(&state->tport);

	free_irq(IRQ_AMIGA_TBE, state);
	free_irq(IRQ_AMIGA_RBF, state);

	return error;
}

static struct platform_driver amiga_serial_driver = {
	.remove = __exit_p(amiga_serial_remove),
	.driver   = {
		.name	= "amiga-serial",
	},
};

module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);


#if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)

/*
 * ------------------------------------------------------------
 * Serial console driver
 * ------------------------------------------------------------
 */

static void amiga_serial_putc(char c)
{
	custom.serdat = (unsigned char)c | 0x100;
	while (!(custom.serdatr & 0x2000))
		barrier();
}

/*
 *	Print a string to the serial port trying not to disturb
 *	any possible real use of the port...
 *
 *	The console must be locked when we get here.
 */
static void serial_console_write(struct console *co, const char *s,
				unsigned count)
{
	unsigned short intena = custom.intenar;

	custom.intena = IF_TBE;

	while (count--) {
		if (*s == '\n')
			amiga_serial_putc('\r');
		amiga_serial_putc(*s++);
	}

	custom.intena = IF_SETCLR | (intena & IF_TBE);
}

static struct tty_driver *serial_console_device(struct console *c, int *index)
{
	*index = 0;
	return serial_driver;
}

static struct console sercons = {
	.name =		"ttyS",
	.write =	serial_console_write,
	.device =	serial_console_device,
	.flags =	CON_PRINTBUFFER,
	.index =	-1,
};

/*
 *	Register console.
 */
static int __init amiserial_console_init(void)
{
	if (!MACH_IS_AMIGA)
		return -ENODEV;

	register_console(&sercons);
	return 0;
}
console_initcall(amiserial_console_init);

#endif /* CONFIG_SERIAL_CONSOLE && !MODULE */

MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-serial");