summaryrefslogtreecommitdiff
path: root/drivers/media/dvb-core/dvb_ca_en50221.c
blob: b462ebc0c544d47d56e341004f1f0e6870bf9204 (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
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
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
/*
 * dvb_ca.c: generic DVB functions for EN50221 CAM interfaces
 *
 * Copyright (C) 2004 Andrew de Quincey
 *
 * Parts of this file were based on sources as follows:
 *
 * Copyright (C) 2003 Ralph Metzler <rjkm@metzlerbros.de>
 *
 * based on code:
 *
 * Copyright (C) 1999-2002 Ralph  Metzler
 *                       & Marcus Metzler for convergence integrated media GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * To obtain the license, point your browser to
 * http://www.gnu.org/copyleft/gpl.html
 */

#define pr_fmt(fmt) "dvb_ca_en50221: " fmt

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/sched/signal.h>
#include <linux/kthread.h>

#include <media/dvb_ca_en50221.h>
#include <media/dvb_ringbuffer.h>

static int dvb_ca_en50221_debug;

module_param_named(cam_debug, dvb_ca_en50221_debug, int, 0644);
MODULE_PARM_DESC(cam_debug, "enable verbose debug messages");

#define dprintk(fmt, arg...) do {					\
	if (dvb_ca_en50221_debug)					\
		printk(KERN_DEBUG pr_fmt("%s: " fmt), __func__, ##arg);\
} while (0)

#define INIT_TIMEOUT_SECS 10

#define HOST_LINK_BUF_SIZE 0x200

#define RX_BUFFER_SIZE 65535

#define MAX_RX_PACKETS_PER_ITERATION 10

#define CTRLIF_DATA      0
#define CTRLIF_COMMAND   1
#define CTRLIF_STATUS    1
#define CTRLIF_SIZE_LOW  2
#define CTRLIF_SIZE_HIGH 3

#define CMDREG_HC        1	/* Host control */
#define CMDREG_SW        2	/* Size write */
#define CMDREG_SR        4	/* Size read */
#define CMDREG_RS        8	/* Reset interface */
#define CMDREG_FRIE   0x40	/* Enable FR interrupt */
#define CMDREG_DAIE   0x80	/* Enable DA interrupt */
#define IRQEN (CMDREG_DAIE)

#define STATUSREG_RE     1	/* read error */
#define STATUSREG_WE     2	/* write error */
#define STATUSREG_FR  0x40	/* module free */
#define STATUSREG_DA  0x80	/* data available */

#define DVB_CA_SLOTSTATE_NONE           0
#define DVB_CA_SLOTSTATE_UNINITIALISED  1
#define DVB_CA_SLOTSTATE_RUNNING        2
#define DVB_CA_SLOTSTATE_INVALID        3
#define DVB_CA_SLOTSTATE_WAITREADY      4
#define DVB_CA_SLOTSTATE_VALIDATE       5
#define DVB_CA_SLOTSTATE_WAITFR         6
#define DVB_CA_SLOTSTATE_LINKINIT       7

/* Information on a CA slot */
struct dvb_ca_slot {
	/* current state of the CAM */
	int slot_state;

	/* mutex used for serializing access to one CI slot */
	struct mutex slot_lock;

	/* Number of CAMCHANGES that have occurred since last processing */
	atomic_t camchange_count;

	/* Type of last CAMCHANGE */
	int camchange_type;

	/* base address of CAM config */
	u32 config_base;

	/* value to write into Config Control register */
	u8 config_option;

	/* if 1, the CAM supports DA IRQs */
	u8 da_irq_supported:1;

	/* size of the buffer to use when talking to the CAM */
	int link_buf_size;

	/* buffer for incoming packets */
	struct dvb_ringbuffer rx_buffer;

	/* timer used during various states of the slot */
	unsigned long timeout;
};

/* Private CA-interface information */
struct dvb_ca_private {
	struct kref refcount;

	/* pointer back to the public data structure */
	struct dvb_ca_en50221 *pub;

	/* the DVB device */
	struct dvb_device *dvbdev;

	/* Flags describing the interface (DVB_CA_FLAG_*) */
	u32 flags;

	/* number of slots supported by this CA interface */
	unsigned int slot_count;

	/* information on each slot */
	struct dvb_ca_slot *slot_info;

	/* wait queues for read() and write() operations */
	wait_queue_head_t wait_queue;

	/* PID of the monitoring thread */
	struct task_struct *thread;

	/* Flag indicating if the CA device is open */
	unsigned int open:1;

	/* Flag indicating the thread should wake up now */
	unsigned int wakeup:1;

	/* Delay the main thread should use */
	unsigned long delay;

	/*
	 * Slot to start looking for data to read from in the next user-space
	 * read operation
	 */
	int next_read_slot;

	/* mutex serializing ioctls */
	struct mutex ioctl_mutex;
};

static void dvb_ca_private_free(struct dvb_ca_private *ca)
{
	unsigned int i;

	dvb_free_device(ca->dvbdev);
	for (i = 0; i < ca->slot_count; i++)
		vfree(ca->slot_info[i].rx_buffer.data);

	kfree(ca->slot_info);
	kfree(ca);
}

static void dvb_ca_private_release(struct kref *ref)
{
	struct dvb_ca_private *ca;

	ca = container_of(ref, struct dvb_ca_private, refcount);
	dvb_ca_private_free(ca);
}

static void dvb_ca_private_get(struct dvb_ca_private *ca)
{
	kref_get(&ca->refcount);
}

static void dvb_ca_private_put(struct dvb_ca_private *ca)
{
	kref_put(&ca->refcount, dvb_ca_private_release);
}

static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca);
static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
				    u8 *ebuf, int ecount);
static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
				     u8 *ebuf, int ecount);

/**
 * Safely find needle in haystack.
 *
 * @haystack: Buffer to look in.
 * @hlen: Number of bytes in haystack.
 * @needle: Buffer to find.
 * @nlen: Number of bytes in needle.
 * return: Pointer into haystack needle was found at, or NULL if not found.
 */
static char *findstr(char *haystack, int hlen, char *needle, int nlen)
{
	int i;

	if (hlen < nlen)
		return NULL;

	for (i = 0; i <= hlen - nlen; i++) {
		if (!strncmp(haystack + i, needle, nlen))
			return haystack + i;
	}

	return NULL;
}

/* ************************************************************************** */
/* EN50221 physical interface functions */

/*
 * dvb_ca_en50221_check_camstatus - Check CAM status.
 */
static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private *ca, int slot)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int slot_status;
	int cam_present_now;
	int cam_changed;

	/* IRQ mode */
	if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
		return (atomic_read(&sl->camchange_count) != 0);

	/* poll mode */
	slot_status = ca->pub->poll_slot_status(ca->pub, slot, ca->open);

	cam_present_now = (slot_status & DVB_CA_EN50221_POLL_CAM_PRESENT) ? 1 : 0;
	cam_changed = (slot_status & DVB_CA_EN50221_POLL_CAM_CHANGED) ? 1 : 0;
	if (!cam_changed) {
		int cam_present_old = (sl->slot_state != DVB_CA_SLOTSTATE_NONE);

		cam_changed = (cam_present_now != cam_present_old);
	}

	if (cam_changed) {
		if (!cam_present_now)
			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
		else
			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
		atomic_set(&sl->camchange_count, 1);
	} else {
		if ((sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
		    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
			/* move to validate state if reset is completed */
			sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
		}
	}

	return cam_changed;
}

/**
 * dvb_ca_en50221_wait_if_status - Wait for flags to become set on the STATUS
 *	 register on a CAM interface, checking for errors and timeout.
 *
 * @ca: CA instance.
 * @slot: Slot on interface.
 * @waitfor: Flags to wait for.
 * @timeout_hz: Timeout in milliseconds.
 *
 * return: 0 on success, nonzero on error.
 */
static int dvb_ca_en50221_wait_if_status(struct dvb_ca_private *ca, int slot,
					 u8 waitfor, int timeout_hz)
{
	unsigned long timeout;
	unsigned long start;

	dprintk("%s\n", __func__);

	/* loop until timeout elapsed */
	start = jiffies;
	timeout = jiffies + timeout_hz;
	while (1) {
		int res;

		/* read the status and check for error */
		res = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
		if (res < 0)
			return -EIO;

		/* if we got the flags, it was successful! */
		if (res & waitfor) {
			dprintk("%s succeeded timeout:%lu\n",
				__func__, jiffies - start);
			return 0;
		}

		/* check for timeout */
		if (time_after(jiffies, timeout))
			break;

		/* wait for a bit */
		usleep_range(1000, 1100);
	}

	dprintk("%s failed timeout:%lu\n", __func__, jiffies - start);

	/* if we get here, we've timed out */
	return -ETIMEDOUT;
}

/**
 * dvb_ca_en50221_link_init - Initialise the link layer connection to a CAM.
 *
 * @ca: CA instance.
 * @slot: Slot id.
 *
 * return: 0 on success, nonzero on failure.
 */
static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int ret;
	int buf_size;
	u8 buf[2];

	dprintk("%s\n", __func__);

	/* we'll be determining these during this function */
	sl->da_irq_supported = 0;

	/*
	 * set the host link buffer size temporarily. it will be overwritten
	 * with the real negotiated size later.
	 */
	sl->link_buf_size = 2;

	/* read the buffer size from the CAM */
	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
					 IRQEN | CMDREG_SR);
	if (ret)
		return ret;
	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ);
	if (ret)
		return ret;
	ret = dvb_ca_en50221_read_data(ca, slot, buf, 2);
	if (ret != 2)
		return -EIO;
	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
	if (ret)
		return ret;

	/*
	 * store it, and choose the minimum of our buffer and the CAM's buffer
	 * size
	 */
	buf_size = (buf[0] << 8) | buf[1];
	if (buf_size > HOST_LINK_BUF_SIZE)
		buf_size = HOST_LINK_BUF_SIZE;
	sl->link_buf_size = buf_size;
	buf[0] = buf_size >> 8;
	buf[1] = buf_size & 0xff;
	dprintk("Chosen link buffer size of %i\n", buf_size);

	/* write the buffer size to the CAM */
	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
					 IRQEN | CMDREG_SW);
	if (ret)
		return ret;
	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10);
	if (ret)
		return ret;
	ret = dvb_ca_en50221_write_data(ca, slot, buf, 2);
	if (ret != 2)
		return -EIO;
	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
	if (ret)
		return ret;

	/* success */
	return 0;
}

/**
 * dvb_ca_en50221_read_tuple - Read a tuple from attribute memory.
 *
 * @ca: CA instance.
 * @slot: Slot id.
 * @address: Address to read from. Updated.
 * @tuple_type: Tuple id byte. Updated.
 * @tuple_length: Tuple length. Updated.
 * @tuple: Dest buffer for tuple (must be 256 bytes). Updated.
 *
 * return: 0 on success, nonzero on error.
 */
static int dvb_ca_en50221_read_tuple(struct dvb_ca_private *ca, int slot,
				     int *address, int *tuple_type,
				     int *tuple_length, u8 *tuple)
{
	int i;
	int _tuple_type;
	int _tuple_length;
	int _address = *address;

	/* grab the next tuple length and type */
	_tuple_type = ca->pub->read_attribute_mem(ca->pub, slot, _address);
	if (_tuple_type < 0)
		return _tuple_type;
	if (_tuple_type == 0xff) {
		dprintk("END OF CHAIN TUPLE type:0x%x\n", _tuple_type);
		*address += 2;
		*tuple_type = _tuple_type;
		*tuple_length = 0;
		return 0;
	}
	_tuple_length = ca->pub->read_attribute_mem(ca->pub, slot,
						    _address + 2);
	if (_tuple_length < 0)
		return _tuple_length;
	_address += 4;

	dprintk("TUPLE type:0x%x length:%i\n", _tuple_type, _tuple_length);

	/* read in the whole tuple */
	for (i = 0; i < _tuple_length; i++) {
		tuple[i] = ca->pub->read_attribute_mem(ca->pub, slot,
						       _address + (i * 2));
		dprintk("  0x%02x: 0x%02x %c\n",
			i, tuple[i] & 0xff,
			((tuple[i] > 31) && (tuple[i] < 127)) ? tuple[i] : '.');
	}
	_address += (_tuple_length * 2);

	/* success */
	*tuple_type = _tuple_type;
	*tuple_length = _tuple_length;
	*address = _address;
	return 0;
}

/**
 * dvb_ca_en50221_parse_attributes - Parse attribute memory of a CAM module,
 *	extracting Config register, and checking it is a DVB CAM module.
 *
 * @ca: CA instance.
 * @slot: Slot id.
 *
 * return: 0 on success, <0 on failure.
 */
static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private *ca, int slot)
{
	struct dvb_ca_slot *sl;
	int address = 0;
	int tuple_length;
	int tuple_type;
	u8 tuple[257];
	char *dvb_str;
	int rasz;
	int status;
	int got_cftableentry = 0;
	int end_chain = 0;
	int i;
	u16 manfid = 0;
	u16 devid = 0;

	/* CISTPL_DEVICE_0A */
	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
					   &tuple_length, tuple);
	if (status < 0)
		return status;
	if (tuple_type != 0x1D)
		return -EINVAL;

	/* CISTPL_DEVICE_0C */
	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
					   &tuple_length, tuple);
	if (status < 0)
		return status;
	if (tuple_type != 0x1C)
		return -EINVAL;

	/* CISTPL_VERS_1 */
	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
					   &tuple_length, tuple);
	if (status < 0)
		return status;
	if (tuple_type != 0x15)
		return -EINVAL;

	/* CISTPL_MANFID */
	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
					   &tuple_length, tuple);
	if (status < 0)
		return status;
	if (tuple_type != 0x20)
		return -EINVAL;
	if (tuple_length != 4)
		return -EINVAL;
	manfid = (tuple[1] << 8) | tuple[0];
	devid = (tuple[3] << 8) | tuple[2];

	/* CISTPL_CONFIG */
	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
					   &tuple_length, tuple);
	if (status < 0)
		return status;
	if (tuple_type != 0x1A)
		return -EINVAL;
	if (tuple_length < 3)
		return -EINVAL;

	/* extract the configbase */
	rasz = tuple[0] & 3;
	if (tuple_length < (3 + rasz + 14))
		return -EINVAL;
	sl = &ca->slot_info[slot];
	sl->config_base = 0;
	for (i = 0; i < rasz + 1; i++)
		sl->config_base |= (tuple[2 + i] << (8 * i));

	/* check it contains the correct DVB string */
	dvb_str = findstr((char *)tuple, tuple_length, "DVB_CI_V", 8);
	if (!dvb_str)
		return -EINVAL;
	if (tuple_length < ((dvb_str - (char *)tuple) + 12))
		return -EINVAL;

	/* is it a version we support? */
	if (strncmp(dvb_str + 8, "1.00", 4)) {
		pr_err("dvb_ca adapter %d: Unsupported DVB CAM module version %c%c%c%c\n",
		       ca->dvbdev->adapter->num, dvb_str[8], dvb_str[9],
		       dvb_str[10], dvb_str[11]);
		return -EINVAL;
	}

	/* process the CFTABLE_ENTRY tuples, and any after those */
	while ((!end_chain) && (address < 0x1000)) {
		status = dvb_ca_en50221_read_tuple(ca, slot, &address,
						   &tuple_type, &tuple_length,
						   tuple);
		if (status < 0)
			return status;
		switch (tuple_type) {
		case 0x1B:	/* CISTPL_CFTABLE_ENTRY */
			if (tuple_length < (2 + 11 + 17))
				break;

			/* if we've already parsed one, just use it */
			if (got_cftableentry)
				break;

			/* get the config option */
			sl->config_option = tuple[0] & 0x3f;

			/* OK, check it contains the correct strings */
			if (!findstr((char *)tuple, tuple_length,
				     "DVB_HOST", 8) ||
			    !findstr((char *)tuple, tuple_length,
				     "DVB_CI_MODULE", 13))
				break;

			got_cftableentry = 1;
			break;

		case 0x14:	/* CISTPL_NO_LINK */
			break;

		case 0xFF:	/* CISTPL_END */
			end_chain = 1;
			break;

		default:	/* Unknown tuple type - just skip this tuple */
			dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n",
				tuple_type, tuple_length);
			break;
		}
	}

	if ((address > 0x1000) || (!got_cftableentry))
		return -EINVAL;

	dprintk("Valid DVB CAM detected MANID:%x DEVID:%x CONFIGBASE:0x%x CONFIGOPTION:0x%x\n",
		manfid, devid, sl->config_base, sl->config_option);

	/* success! */
	return 0;
}

/**
 * dvb_ca_en50221_set_configoption - Set CAM's configoption correctly.
 *
 * @ca: CA instance.
 * @slot: Slot containing the CAM.
 */
static int dvb_ca_en50221_set_configoption(struct dvb_ca_private *ca, int slot)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int configoption;

	dprintk("%s\n", __func__);

	/* set the config option */
	ca->pub->write_attribute_mem(ca->pub, slot, sl->config_base,
				     sl->config_option);

	/* check it */
	configoption = ca->pub->read_attribute_mem(ca->pub, slot,
						   sl->config_base);
	dprintk("Set configoption 0x%x, read configoption 0x%x\n",
		sl->config_option, configoption & 0x3f);

	/* fine! */
	return 0;
}

/**
 * dvb_ca_en50221_read_data - This function talks to an EN50221 CAM control
 *	interface. It reads a buffer of data from the CAM. The data can either
 *	be stored in a supplied buffer, or automatically be added to the slot's
 *	rx_buffer.
 *
 * @ca: CA instance.
 * @slot: Slot to read from.
 * @ebuf: If non-NULL, the data will be written to this buffer. If NULL,
 *	  the data will be added into the buffering system as a normal
 *	  fragment.
 * @ecount: Size of ebuf. Ignored if ebuf is NULL.
 *
 * return: Number of bytes read, or < 0 on error
 */
static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
				    u8 *ebuf, int ecount)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int bytes_read;
	int status;
	u8 buf[HOST_LINK_BUF_SIZE];
	int i;

	dprintk("%s\n", __func__);

	/* check if we have space for a link buf in the rx_buffer */
	if (!ebuf) {
		int buf_free;

		if (!sl->rx_buffer.data) {
			status = -EIO;
			goto exit;
		}
		buf_free = dvb_ringbuffer_free(&sl->rx_buffer);

		if (buf_free < (sl->link_buf_size +
				DVB_RINGBUFFER_PKTHDRSIZE)) {
			status = -EAGAIN;
			goto exit;
		}
	}

	if (ca->pub->read_data &&
	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT)) {
		if (!ebuf)
			status = ca->pub->read_data(ca->pub, slot, buf,
						    sizeof(buf));
		else
			status = ca->pub->read_data(ca->pub, slot, buf, ecount);
		if (status < 0)
			return status;
		bytes_read =  status;
		if (status == 0)
			goto exit;
	} else {
		/* check if there is data available */
		status = ca->pub->read_cam_control(ca->pub, slot,
						   CTRLIF_STATUS);
		if (status < 0)
			goto exit;
		if (!(status & STATUSREG_DA)) {
			/* no data */
			status = 0;
			goto exit;
		}

		/* read the amount of data */
		status = ca->pub->read_cam_control(ca->pub, slot,
						   CTRLIF_SIZE_HIGH);
		if (status < 0)
			goto exit;
		bytes_read = status << 8;
		status = ca->pub->read_cam_control(ca->pub, slot,
						   CTRLIF_SIZE_LOW);
		if (status < 0)
			goto exit;
		bytes_read |= status;

		/* check it will fit */
		if (!ebuf) {
			if (bytes_read > sl->link_buf_size) {
				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the link buffer size (%i > %i)!\n",
				       ca->dvbdev->adapter->num, bytes_read,
				       sl->link_buf_size);
				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
				status = -EIO;
				goto exit;
			}
			if (bytes_read < 2) {
				pr_err("dvb_ca adapter %d: CAM sent a buffer that was less than 2 bytes!\n",
				       ca->dvbdev->adapter->num);
				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
				status = -EIO;
				goto exit;
			}
		} else {
			if (bytes_read > ecount) {
				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the ecount size!\n",
				       ca->dvbdev->adapter->num);
				status = -EIO;
				goto exit;
			}
		}

		/* fill the buffer */
		for (i = 0; i < bytes_read; i++) {
			/* read byte and check */
			status = ca->pub->read_cam_control(ca->pub, slot,
							   CTRLIF_DATA);
			if (status < 0)
				goto exit;

			/* OK, store it in the buffer */
			buf[i] = status;
		}

		/* check for read error (RE should now be 0) */
		status = ca->pub->read_cam_control(ca->pub, slot,
						   CTRLIF_STATUS);
		if (status < 0)
			goto exit;
		if (status & STATUSREG_RE) {
			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
			status = -EIO;
			goto exit;
		}
	}

	/*
	 * OK, add it to the receive buffer, or copy into external buffer if
	 * supplied
	 */
	if (!ebuf) {
		if (!sl->rx_buffer.data) {
			status = -EIO;
			goto exit;
		}
		dvb_ringbuffer_pkt_write(&sl->rx_buffer, buf, bytes_read);
	} else {
		memcpy(ebuf, buf, bytes_read);
	}

	dprintk("Received CA packet for slot %i connection id 0x%x last_frag:%i size:0x%x\n", slot,
		buf[0], (buf[1] & 0x80) == 0, bytes_read);

	/* wake up readers when a last_fragment is received */
	if ((buf[1] & 0x80) == 0x00)
		wake_up_interruptible(&ca->wait_queue);

	status = bytes_read;

exit:
	return status;
}

/**
 * dvb_ca_en50221_write_data - This function talks to an EN50221 CAM control
 *				interface. It writes a buffer of data to a CAM.
 *
 * @ca: CA instance.
 * @slot: Slot to write to.
 * @buf: The data in this buffer is treated as a complete link-level packet to
 *	 be written.
 * @bytes_write: Size of ebuf.
 *
 * return: Number of bytes written, or < 0 on error.
 */
static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
				     u8 *buf, int bytes_write)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int status;
	int i;

	dprintk("%s\n", __func__);

	/* sanity check */
	if (bytes_write > sl->link_buf_size)
		return -EINVAL;

	if (ca->pub->write_data &&
	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT))
		return ca->pub->write_data(ca->pub, slot, buf, bytes_write);

	/*
	 * it is possible we are dealing with a single buffer implementation,
	 * thus if there is data available for read or if there is even a read
	 * already in progress, we do nothing but awake the kernel thread to
	 * process the data if necessary.
	 */
	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
	if (status < 0)
		goto exitnowrite;
	if (status & (STATUSREG_DA | STATUSREG_RE)) {
		if (status & STATUSREG_DA)
			dvb_ca_en50221_thread_wakeup(ca);

		status = -EAGAIN;
		goto exitnowrite;
	}

	/* OK, set HC bit */
	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
					    IRQEN | CMDREG_HC);
	if (status)
		goto exit;

	/* check if interface is still free */
	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
	if (status < 0)
		goto exit;
	if (!(status & STATUSREG_FR)) {
		/* it wasn't free => try again later */
		status = -EAGAIN;
		goto exit;
	}

	/*
	 * It may need some time for the CAM to settle down, or there might
	 * be a race condition between the CAM, writing HC and our last
	 * check for DA. This happens, if the CAM asserts DA, just after
	 * checking DA before we are setting HC. In this case it might be
	 * a bug in the CAM to keep the FR bit, the lower layer/HW
	 * communication requires a longer timeout or the CAM needs more
	 * time internally. But this happens in reality!
	 * We need to read the status from the HW again and do the same
	 * we did for the previous check for DA
	 */
	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
	if (status < 0)
		goto exit;

	if (status & (STATUSREG_DA | STATUSREG_RE)) {
		if (status & STATUSREG_DA)
			dvb_ca_en50221_thread_wakeup(ca);

		status = -EAGAIN;
		goto exit;
	}

	/* send the amount of data */
	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH,
					    bytes_write >> 8);
	if (status)
		goto exit;
	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW,
					    bytes_write & 0xff);
	if (status)
		goto exit;

	/* send the buffer */
	for (i = 0; i < bytes_write; i++) {
		status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA,
						    buf[i]);
		if (status)
			goto exit;
	}

	/* check for write error (WE should now be 0) */
	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
	if (status < 0)
		goto exit;
	if (status & STATUSREG_WE) {
		sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
		status = -EIO;
		goto exit;
	}
	status = bytes_write;

	dprintk("Wrote CA packet for slot %i, connection id 0x%x last_frag:%i size:0x%x\n", slot,
		buf[0], (buf[1] & 0x80) == 0, bytes_write);

exit:
	ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);

exitnowrite:
	return status;
}

/* ************************************************************************** */
/* EN50221 higher level functions */

/**
 * dvb_ca_en50221_slot_shutdown - A CAM has been removed => shut it down.
 *
 * @ca: CA instance.
 * @slot: Slot to shut down.
 */
static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private *ca, int slot)
{
	dprintk("%s\n", __func__);

	ca->pub->slot_shutdown(ca->pub, slot);
	ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;

	/*
	 * need to wake up all processes to check if they're now trying to
	 * write to a defunct CAM
	 */
	wake_up_interruptible(&ca->wait_queue);

	dprintk("Slot %i shutdown\n", slot);

	/* success */
	return 0;
}

/**
 * dvb_ca_en50221_camchange_irq - A CAMCHANGE IRQ has occurred.
 *
 * @pubca: CA instance.
 * @slot: Slot concerned.
 * @change_type: One of the DVB_CA_CAMCHANGE_* values.
 */
void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221 *pubca, int slot,
				  int change_type)
{
	struct dvb_ca_private *ca = pubca->private;
	struct dvb_ca_slot *sl = &ca->slot_info[slot];

	dprintk("CAMCHANGE IRQ slot:%i change_type:%i\n", slot, change_type);

	switch (change_type) {
	case DVB_CA_EN50221_CAMCHANGE_REMOVED:
	case DVB_CA_EN50221_CAMCHANGE_INSERTED:
		break;

	default:
		return;
	}

	sl->camchange_type = change_type;
	atomic_inc(&sl->camchange_count);
	dvb_ca_en50221_thread_wakeup(ca);
}
EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);

/**
 * dvb_ca_en50221_camready_irq - A CAMREADY IRQ has occurred.
 *
 * @pubca: CA instance.
 * @slot: Slot concerned.
 */
void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 *pubca, int slot)
{
	struct dvb_ca_private *ca = pubca->private;
	struct dvb_ca_slot *sl = &ca->slot_info[slot];

	dprintk("CAMREADY IRQ slot:%i\n", slot);

	if (sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
		sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
		dvb_ca_en50221_thread_wakeup(ca);
	}
}
EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);

/**
 * dvb_ca_en50221_frda_irq - An FR or DA IRQ has occurred.
 *
 * @pubca: CA instance.
 * @slot: Slot concerned.
 */
void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
{
	struct dvb_ca_private *ca = pubca->private;
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int flags;

	dprintk("FR/DA IRQ slot:%i\n", slot);

	switch (sl->slot_state) {
	case DVB_CA_SLOTSTATE_LINKINIT:
		flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
		if (flags & STATUSREG_DA) {
			dprintk("CAM supports DA IRQ\n");
			sl->da_irq_supported = 1;
		}
		break;

	case DVB_CA_SLOTSTATE_RUNNING:
		if (ca->open)
			dvb_ca_en50221_thread_wakeup(ca);
		break;
	}
}
EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);

/* ************************************************************************** */
/* EN50221 thread functions */

/**
 * Wake up the DVB CA thread
 *
 * @ca: CA instance.
 */
static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca)
{
	dprintk("%s\n", __func__);

	ca->wakeup = 1;
	mb();
	wake_up_process(ca->thread);
}

/**
 * Update the delay used by the thread.
 *
 * @ca: CA instance.
 */
static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private *ca)
{
	int delay;
	int curdelay = 100000000;
	int slot;

	/*
	 * Beware of too high polling frequency, because one polling
	 * call might take several hundred milliseconds until timeout!
	 */
	for (slot = 0; slot < ca->slot_count; slot++) {
		struct dvb_ca_slot *sl = &ca->slot_info[slot];

		switch (sl->slot_state) {
		default:
		case DVB_CA_SLOTSTATE_NONE:
			delay = HZ * 60;  /* 60s */
			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
				delay = HZ * 5;  /* 5s */
			break;
		case DVB_CA_SLOTSTATE_INVALID:
			delay = HZ * 60;  /* 60s */
			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
				delay = HZ / 10;  /* 100ms */
			break;

		case DVB_CA_SLOTSTATE_UNINITIALISED:
		case DVB_CA_SLOTSTATE_WAITREADY:
		case DVB_CA_SLOTSTATE_VALIDATE:
		case DVB_CA_SLOTSTATE_WAITFR:
		case DVB_CA_SLOTSTATE_LINKINIT:
			delay = HZ / 10;  /* 100ms */
			break;

		case DVB_CA_SLOTSTATE_RUNNING:
			delay = HZ * 60;  /* 60s */
			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
				delay = HZ / 10;  /* 100ms */
			if (ca->open) {
				if ((!sl->da_irq_supported) ||
				    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA)))
					delay = HZ / 10;  /* 100ms */
			}
			break;
		}

		if (delay < curdelay)
			curdelay = delay;
	}

	ca->delay = curdelay;
}

/**
 * Poll if the CAM is gone.
 *
 * @ca: CA instance.
 * @slot: Slot to process.
 * return:: 0 .. no change
 *          1 .. CAM state changed
 */

static int dvb_ca_en50221_poll_cam_gone(struct dvb_ca_private *ca, int slot)
{
	int changed = 0;
	int status;

	/*
	 * we need this extra check for annoying interfaces like the
	 * budget-av
	 */
	if ((!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) &&
	    (ca->pub->poll_slot_status)) {
		status = ca->pub->poll_slot_status(ca->pub, slot, 0);
		if (!(status &
			DVB_CA_EN50221_POLL_CAM_PRESENT)) {
			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
			dvb_ca_en50221_thread_update_delay(ca);
			changed = 1;
		}
	}
	return changed;
}

/**
 * Thread state machine for one CA slot to perform the data transfer.
 *
 * @ca: CA instance.
 * @slot: Slot to process.
 */
static void dvb_ca_en50221_thread_state_machine(struct dvb_ca_private *ca,
						int slot)
{
	struct dvb_ca_slot *sl = &ca->slot_info[slot];
	int flags;
	int pktcount;
	void *rxbuf;

	mutex_lock(&sl->slot_lock);

	/* check the cam status + deal with CAMCHANGEs */
	while (dvb_ca_en50221_check_camstatus(ca, slot)) {
		/* clear down an old CI slot if necessary */
		if (sl->slot_state != DVB_CA_SLOTSTATE_NONE)
			dvb_ca_en50221_slot_shutdown(ca, slot);

		/* if a CAM is NOW present, initialise it */
		if (sl->camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED)
			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;

		/* we've handled one CAMCHANGE */
		dvb_ca_en50221_thread_update_delay(ca);
		atomic_dec(&sl->camchange_count);
	}

	/* CAM state machine */
	switch (sl->slot_state) {
	case DVB_CA_SLOTSTATE_NONE:
	case DVB_CA_SLOTSTATE_INVALID:
		/* no action needed */
		break;

	case DVB_CA_SLOTSTATE_UNINITIALISED:
		sl->slot_state = DVB_CA_SLOTSTATE_WAITREADY;
		ca->pub->slot_reset(ca->pub, slot);
		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
		break;

	case DVB_CA_SLOTSTATE_WAITREADY:
		if (time_after(jiffies, sl->timeout)) {
			pr_err("dvb_ca adaptor %d: PC card did not respond :(\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}
		/*
		 * no other action needed; will automatically change state when
		 * ready
		 */
		break;

	case DVB_CA_SLOTSTATE_VALIDATE:
		if (dvb_ca_en50221_parse_attributes(ca, slot) != 0) {
			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
				break;

			pr_err("dvb_ca adapter %d: Invalid PC card inserted :(\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}
		if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
			pr_err("dvb_ca adapter %d: Unable to initialise CAM :(\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}
		if (ca->pub->write_cam_control(ca->pub, slot,
					       CTRLIF_COMMAND,
					       CMDREG_RS) != 0) {
			pr_err("dvb_ca adapter %d: Unable to reset CAM IF\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}
		dprintk("DVB CAM validated successfully\n");

		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
		sl->slot_state = DVB_CA_SLOTSTATE_WAITFR;
		ca->wakeup = 1;
		break;

	case DVB_CA_SLOTSTATE_WAITFR:
		if (time_after(jiffies, sl->timeout)) {
			pr_err("dvb_ca adapter %d: DVB CAM did not respond :(\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}

		flags = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
		if (flags & STATUSREG_FR) {
			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
			ca->wakeup = 1;
		}
		break;

	case DVB_CA_SLOTSTATE_LINKINIT:
		if (dvb_ca_en50221_link_init(ca, slot) != 0) {
			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
				break;

			pr_err("dvb_ca adapter %d: DVB CAM link initialisation failed :(\n",
			       ca->dvbdev->adapter->num);
			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
			dvb_ca_en50221_thread_update_delay(ca);
			break;
		}

		if (!sl->rx_buffer.data) {
			rxbuf = vmalloc(RX_BUFFER_SIZE);
			if (!rxbuf) {
				pr_err("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n",
				       ca->dvbdev->adapter->num);
				sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
				dvb_ca_en50221_thread_update_delay(ca);
				break;
			}
			dvb_ringbuffer_init(&sl->rx_buffer, rxbuf,
					    RX_BUFFER_SIZE);
		}

		ca->pub->slot_ts_enable(ca->pub, slot);
		sl->slot_state = DVB_CA_SLOTSTATE_RUNNING;
		dvb_ca_en50221_thread_update_delay(ca);
		pr_err("dvb_ca adapter %d: DVB CAM detected and initialised successfully\n",
		       ca->dvbdev->adapter->num);
		break;

	case DVB_CA_SLOTSTATE_RUNNING:
		if (!ca->open)
			break;

		/* poll slots for data */
		pktcount = 0;
		while (dvb_ca_en50221_read_data(ca, slot, NULL, 0) > 0) {
			if (!ca->open)
				break;

			/*
			 * if a CAMCHANGE occurred at some point, do not do any
			 * more processing of this slot
			 */
			if (dvb_ca_en50221_check_camstatus(ca, slot)) {
				/*
				 * we don't want to sleep on the next iteration
				 * so we can handle the cam change
				 */
				ca->wakeup = 1;
				break;
			}

			/* check if we've hit our limit this time */
			if (++pktcount >= MAX_RX_PACKETS_PER_ITERATION) {
				/*
				 * don't sleep; there is likely to be more data
				 * to read
				 */
				ca->wakeup = 1;
				break;
			}
		}
		break;
	}

	mutex_unlock(&sl->slot_lock);
}

/*
 * Kernel thread which monitors CA slots for CAM changes, and performs data
 * transfers.
 */
static int dvb_ca_en50221_thread(void *data)
{
	struct dvb_ca_private *ca = data;
	int slot;

	dprintk("%s\n", __func__);

	/* choose the correct initial delay */
	dvb_ca_en50221_thread_update_delay(ca);

	/* main loop */
	while (!kthread_should_stop()) {
		/* sleep for a bit */
		if (!ca->wakeup) {
			set_current_state(TASK_INTERRUPTIBLE);
			schedule_timeout(ca->delay);
			if (kthread_should_stop())
				return 0;
		}
		ca->wakeup = 0;

		/* go through all the slots processing them */
		for (slot = 0; slot < ca->slot_count; slot++)
			dvb_ca_en50221_thread_state_machine(ca, slot);
	}

	return 0;
}

/* ************************************************************************** */
/* EN50221 IO interface functions */

/**
 * Real ioctl implementation.
 * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
 *
 * @file: File concerned.
 * @cmd: IOCTL command.
 * @parg: Associated argument.
 *
 * return: 0 on success, <0 on error.
 */
static int dvb_ca_en50221_io_do_ioctl(struct file *file,
				      unsigned int cmd, void *parg)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err = 0;
	int slot;

	dprintk("%s\n", __func__);

	if (mutex_lock_interruptible(&ca->ioctl_mutex))
		return -ERESTARTSYS;

	switch (cmd) {
	case CA_RESET:
		for (slot = 0; slot < ca->slot_count; slot++) {
			struct dvb_ca_slot *sl = &ca->slot_info[slot];

			mutex_lock(&sl->slot_lock);
			if (sl->slot_state != DVB_CA_SLOTSTATE_NONE) {
				dvb_ca_en50221_slot_shutdown(ca, slot);
				if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
					dvb_ca_en50221_camchange_irq(ca->pub,
								     slot,
								     DVB_CA_EN50221_CAMCHANGE_INSERTED);
			}
			mutex_unlock(&sl->slot_lock);
		}
		ca->next_read_slot = 0;
		dvb_ca_en50221_thread_wakeup(ca);
		break;

	case CA_GET_CAP: {
		struct ca_caps *caps = parg;

		caps->slot_num = ca->slot_count;
		caps->slot_type = CA_CI_LINK;
		caps->descr_num = 0;
		caps->descr_type = 0;
		break;
	}

	case CA_GET_SLOT_INFO: {
		struct ca_slot_info *info = parg;
		struct dvb_ca_slot *sl;

		slot = info->num;
		if ((slot > ca->slot_count) || (slot < 0)) {
			err = -EINVAL;
			goto out_unlock;
		}

		info->type = CA_CI_LINK;
		info->flags = 0;
		sl = &ca->slot_info[slot];
		if ((sl->slot_state != DVB_CA_SLOTSTATE_NONE) &&
		    (sl->slot_state != DVB_CA_SLOTSTATE_INVALID)) {
			info->flags = CA_CI_MODULE_PRESENT;
		}
		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING)
			info->flags |= CA_CI_MODULE_READY;
		break;
	}

	default:
		err = -EINVAL;
		break;
	}

out_unlock:
	mutex_unlock(&ca->ioctl_mutex);
	return err;
}

/**
 * Wrapper for ioctl implementation.
 *
 * @file: File concerned.
 * @cmd: IOCTL command.
 * @arg: Associated argument.
 *
 * return: 0 on success, <0 on error.
 */
static long dvb_ca_en50221_io_ioctl(struct file *file,
				    unsigned int cmd, unsigned long arg)
{
	return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
}

/**
 * Implementation of write() syscall.
 *
 * @file: File structure.
 * @buf: Source buffer.
 * @count: Size of source buffer.
 * @ppos: Position in file (ignored).
 *
 * return: Number of bytes read, or <0 on error.
 */
static ssize_t dvb_ca_en50221_io_write(struct file *file,
				       const char __user *buf, size_t count,
				       loff_t *ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	struct dvb_ca_slot *sl;
	u8 slot, connection_id;
	int status;
	u8 fragbuf[HOST_LINK_BUF_SIZE];
	int fragpos = 0;
	int fraglen;
	unsigned long timeout;
	int written;

	dprintk("%s\n", __func__);

	/*
	 * Incoming packet has a 2 byte header.
	 * hdr[0] = slot_id, hdr[1] = connection_id
	 */
	if (count < 2)
		return -EINVAL;

	/* extract slot & connection id */
	if (copy_from_user(&slot, buf, 1))
		return -EFAULT;
	if (copy_from_user(&connection_id, buf + 1, 1))
		return -EFAULT;
	buf += 2;
	count -= 2;

	if (slot >= ca->slot_count)
		return -EINVAL;
	sl = &ca->slot_info[slot];

	/* check if the slot is actually running */
	if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
		return -EINVAL;

	/* fragment the packets & store in the buffer */
	while (fragpos < count) {
		fraglen = sl->link_buf_size - 2;
		if (fraglen < 0)
			break;
		if (fraglen > HOST_LINK_BUF_SIZE - 2)
			fraglen = HOST_LINK_BUF_SIZE - 2;
		if ((count - fragpos) < fraglen)
			fraglen = count - fragpos;

		fragbuf[0] = connection_id;
		fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
		status = copy_from_user(fragbuf + 2, buf + fragpos, fraglen);
		if (status) {
			status = -EFAULT;
			goto exit;
		}

		timeout = jiffies + HZ / 2;
		written = 0;
		while (!time_after(jiffies, timeout)) {
			/*
			 * check the CAM hasn't been removed/reset in the
			 * meantime
			 */
			if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING) {
				status = -EIO;
				goto exit;
			}

			mutex_lock(&sl->slot_lock);
			status = dvb_ca_en50221_write_data(ca, slot, fragbuf,
							   fraglen + 2);
			mutex_unlock(&sl->slot_lock);
			if (status == (fraglen + 2)) {
				written = 1;
				break;
			}
			if (status != -EAGAIN)
				goto exit;

			usleep_range(1000, 1100);
		}
		if (!written) {
			status = -EIO;
			goto exit;
		}

		fragpos += fraglen;
	}
	status = count + 2;

exit:
	return status;
}

/*
 * Condition for waking up in dvb_ca_en50221_io_read_condition
 */
static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
					    int *result, int *_slot)
{
	int slot;
	int slot_count = 0;
	int idx;
	size_t fraglen;
	int connection_id = -1;
	int found = 0;
	u8 hdr[2];

	slot = ca->next_read_slot;
	while ((slot_count < ca->slot_count) && (!found)) {
		struct dvb_ca_slot *sl = &ca->slot_info[slot];

		if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
			goto nextslot;

		if (!sl->rx_buffer.data)
			return 0;

		idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
		while (idx != -1) {
			dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
			if (connection_id == -1)
				connection_id = hdr[0];
			if ((hdr[0] == connection_id) &&
			    ((hdr[1] & 0x80) == 0)) {
				*_slot = slot;
				found = 1;
				break;
			}

			idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx,
						      &fraglen);
		}

nextslot:
		slot = (slot + 1) % ca->slot_count;
		slot_count++;
	}

	ca->next_read_slot = slot;
	return found;
}

/**
 * Implementation of read() syscall.
 *
 * @file: File structure.
 * @buf: Destination buffer.
 * @count: Size of destination buffer.
 * @ppos: Position in file (ignored).
 *
 * return: Number of bytes read, or <0 on error.
 */
static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user *buf,
				      size_t count, loff_t *ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	struct dvb_ca_slot *sl;
	int status;
	int result = 0;
	u8 hdr[2];
	int slot;
	int connection_id = -1;
	size_t idx, idx2;
	int last_fragment = 0;
	size_t fraglen;
	int pktlen;
	int dispose = 0;

	dprintk("%s\n", __func__);

	/*
	 * Outgoing packet has a 2 byte header.
	 * hdr[0] = slot_id, hdr[1] = connection_id
	 */
	if (count < 2)
		return -EINVAL;

	/* wait for some data */
	status = dvb_ca_en50221_io_read_condition(ca, &result, &slot);
	if (status == 0) {
		/* if we're in nonblocking mode, exit immediately */
		if (file->f_flags & O_NONBLOCK)
			return -EWOULDBLOCK;

		/* wait for some data */
		status = wait_event_interruptible(ca->wait_queue,
						  dvb_ca_en50221_io_read_condition
						  (ca, &result, &slot));
	}
	if ((status < 0) || (result < 0)) {
		if (result)
			return result;
		return status;
	}

	sl = &ca->slot_info[slot];
	idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
	pktlen = 2;
	do {
		if (idx == -1) {
			pr_err("dvb_ca adapter %d: BUG: read packet ended before last_fragment encountered\n",
			       ca->dvbdev->adapter->num);
			status = -EIO;
			goto exit;
		}

		dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
		if (connection_id == -1)
			connection_id = hdr[0];
		if (hdr[0] == connection_id) {
			if (pktlen < count) {
				if ((pktlen + fraglen - 2) > count)
					fraglen = count - pktlen;
				else
					fraglen -= 2;

				status =
				   dvb_ringbuffer_pkt_read_user(&sl->rx_buffer,
								idx, 2,
								buf + pktlen,
								fraglen);
				if (status < 0)
					goto exit;

				pktlen += fraglen;
			}

			if ((hdr[1] & 0x80) == 0)
				last_fragment = 1;
			dispose = 1;
		}

		idx2 = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx, &fraglen);
		if (dispose)
			dvb_ringbuffer_pkt_dispose(&sl->rx_buffer, idx);
		idx = idx2;
		dispose = 0;
	} while (!last_fragment);

	hdr[0] = slot;
	hdr[1] = connection_id;
	status = copy_to_user(buf, hdr, 2);
	if (status) {
		status = -EFAULT;
		goto exit;
	}
	status = pktlen;

exit:
	return status;
}

/**
 * Implementation of file open syscall.
 *
 * @inode: Inode concerned.
 * @file: File concerned.
 *
 * return: 0 on success, <0 on failure.
 */
static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err;
	int i;

	dprintk("%s\n", __func__);

	if (!try_module_get(ca->pub->owner))
		return -EIO;

	err = dvb_generic_open(inode, file);
	if (err < 0) {
		module_put(ca->pub->owner);
		return err;
	}

	for (i = 0; i < ca->slot_count; i++) {
		struct dvb_ca_slot *sl = &ca->slot_info[i];

		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING) {
			if (!sl->rx_buffer.data) {
				/*
				 * it is safe to call this here without locks
				 * because ca->open == 0. Data is not read in
				 * this case
				 */
				dvb_ringbuffer_flush(&sl->rx_buffer);
			}
		}
	}

	ca->open = 1;
	dvb_ca_en50221_thread_update_delay(ca);
	dvb_ca_en50221_thread_wakeup(ca);

	dvb_ca_private_get(ca);

	return 0;
}

/**
 * Implementation of file close syscall.
 *
 * @inode: Inode concerned.
 * @file: File concerned.
 *
 * return: 0 on success, <0 on failure.
 */
static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err;

	dprintk("%s\n", __func__);

	/* mark the CA device as closed */
	ca->open = 0;
	dvb_ca_en50221_thread_update_delay(ca);

	err = dvb_generic_release(inode, file);

	module_put(ca->pub->owner);

	dvb_ca_private_put(ca);

	return err;
}

/**
 * Implementation of poll() syscall.
 *
 * @file: File concerned.
 * @wait: poll wait table.
 *
 * return: Standard poll mask.
 */
static __poll_t dvb_ca_en50221_io_poll(struct file *file, poll_table *wait)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	__poll_t mask = 0;
	int slot;
	int result = 0;

	dprintk("%s\n", __func__);

	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
		mask |= POLLIN;

	/* if there is something, return now */
	if (mask)
		return mask;

	/* wait for something to happen */
	poll_wait(file, &ca->wait_queue, wait);

	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
		mask |= POLLIN;

	return mask;
}

static const struct file_operations dvb_ca_fops = {
	.owner = THIS_MODULE,
	.read = dvb_ca_en50221_io_read,
	.write = dvb_ca_en50221_io_write,
	.unlocked_ioctl = dvb_ca_en50221_io_ioctl,
	.open = dvb_ca_en50221_io_open,
	.release = dvb_ca_en50221_io_release,
	.poll = dvb_ca_en50221_io_poll,
	.llseek = noop_llseek,
};

static const struct dvb_device dvbdev_ca = {
	.priv = NULL,
	.users = 1,
	.readers = 1,
	.writers = 1,
#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
	.name = "dvb-ca-en50221",
#endif
	.fops = &dvb_ca_fops,
};

/* ************************************************************************** */
/* Initialisation/shutdown functions */

/**
 * Initialise a new DVB CA EN50221 interface device.
 *
 * @dvb_adapter: DVB adapter to attach the new CA device to.
 * @pubca: The dvb_ca instance.
 * @flags: Flags describing the CA device (DVB_CA_FLAG_*).
 * @slot_count: Number of slots supported.
 *
 * return: 0 on success, nonzero on failure
 */
int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
			struct dvb_ca_en50221 *pubca, int flags, int slot_count)
{
	int ret;
	struct dvb_ca_private *ca = NULL;
	int i;

	dprintk("%s\n", __func__);

	if (slot_count < 1)
		return -EINVAL;

	/* initialise the system data */
	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
	if (!ca) {
		ret = -ENOMEM;
		goto exit;
	}
	kref_init(&ca->refcount);
	ca->pub = pubca;
	ca->flags = flags;
	ca->slot_count = slot_count;
	ca->slot_info = kcalloc(slot_count, sizeof(struct dvb_ca_slot),
				GFP_KERNEL);
	if (!ca->slot_info) {
		ret = -ENOMEM;
		goto free_ca;
	}
	init_waitqueue_head(&ca->wait_queue);
	ca->open = 0;
	ca->wakeup = 0;
	ca->next_read_slot = 0;
	pubca->private = ca;

	/* register the DVB device */
	ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca,
				  DVB_DEVICE_CA, 0);
	if (ret)
		goto free_slot_info;

	/* now initialise each slot */
	for (i = 0; i < slot_count; i++) {
		struct dvb_ca_slot *sl = &ca->slot_info[i];

		memset(sl, 0, sizeof(struct dvb_ca_slot));
		sl->slot_state = DVB_CA_SLOTSTATE_NONE;
		atomic_set(&sl->camchange_count, 0);
		sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
		mutex_init(&sl->slot_lock);
	}

	mutex_init(&ca->ioctl_mutex);

	if (signal_pending(current)) {
		ret = -EINTR;
		goto unregister_device;
	}
	mb();

	/* create a kthread for monitoring this CA device */
	ca->thread = kthread_run(dvb_ca_en50221_thread, ca, "kdvb-ca-%i:%i",
				 ca->dvbdev->adapter->num, ca->dvbdev->id);
	if (IS_ERR(ca->thread)) {
		ret = PTR_ERR(ca->thread);
		pr_err("dvb_ca_init: failed to start kernel_thread (%d)\n",
		       ret);
		goto unregister_device;
	}
	return 0;

unregister_device:
	dvb_unregister_device(ca->dvbdev);
free_slot_info:
	kfree(ca->slot_info);
free_ca:
	kfree(ca);
exit:
	pubca->private = NULL;
	return ret;
}
EXPORT_SYMBOL(dvb_ca_en50221_init);

/**
 * Release a DVB CA EN50221 interface device.
 *
 * @pubca: The associated dvb_ca instance.
 */
void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
{
	struct dvb_ca_private *ca = pubca->private;
	int i;

	dprintk("%s\n", __func__);

	/* shutdown the thread if there was one */
	kthread_stop(ca->thread);

	for (i = 0; i < ca->slot_count; i++)
		dvb_ca_en50221_slot_shutdown(ca, i);

	dvb_remove_device(ca->dvbdev);
	dvb_ca_private_put(ca);
	pubca->private = NULL;
}
EXPORT_SYMBOL(dvb_ca_en50221_release);