summaryrefslogtreecommitdiff
path: root/drivers/auxdisplay/panel.c
blob: 1c82d824ae0078ea57d1cf3810f04bfd4e682dc0 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Front panel driver for Linux
 * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu>
 * Copyright (C) 2016-2017 Glider bvba
 *
 * This code drives an LCD module (/dev/lcd), and a keypad (/dev/keypad)
 * connected to a parallel printer port.
 *
 * The LCD module may either be an HD44780-like 8-bit parallel LCD, or a 1-bit
 * serial module compatible with Samsung's KS0074. The pins may be connected in
 * any combination, everything is programmable.
 *
 * The keypad consists in a matrix of push buttons connecting input pins to
 * data output pins or to the ground. The combinations have to be hard-coded
 * in the driver, though several profiles exist and adding new ones is easy.
 *
 * Several profiles are provided for commonly found LCD+keypad modules on the
 * market, such as those found in Nexcom's appliances.
 *
 * FIXME:
 *      - the initialization/deinitialization process is very dirty and should
 *        be rewritten. It may even be buggy.
 *
 * TODO:
 *	- document 24 keys keyboard (3 rows of 8 cols, 32 diodes + 2 inputs)
 *      - make the LCD a part of a virtual screen of Vx*Vy
 *	- make the inputs list smp-safe
 *      - change the keyboard to a double mapping : signals -> key_id -> values
 *        so that applications can change values without knowing signals
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/parport.h>
#include <linux/list.h>

#include <linux/io.h>
#include <linux/uaccess.h>

#include "charlcd.h"

#define LCD_MAXBYTES		256	/* max burst write */

#define KEYPAD_BUFFER		64

/* poll the keyboard this every second */
#define INPUT_POLL_TIME		(HZ / 50)
/* a key starts to repeat after this times INPUT_POLL_TIME */
#define KEYPAD_REP_START	(10)
/* a key repeats this times INPUT_POLL_TIME */
#define KEYPAD_REP_DELAY	(2)

/* converts an r_str() input to an active high, bits string : 000BAOSE */
#define PNL_PINPUT(a)		((((unsigned char)(a)) ^ 0x7F) >> 3)

#define PNL_PBUSY		0x80	/* inverted input, active low */
#define PNL_PACK		0x40	/* direct input, active low */
#define PNL_POUTPA		0x20	/* direct input, active high */
#define PNL_PSELECD		0x10	/* direct input, active high */
#define PNL_PERRORP		0x08	/* direct input, active low */

#define PNL_PBIDIR		0x20	/* bi-directional ports */
/* high to read data in or-ed with data out */
#define PNL_PINTEN		0x10
#define PNL_PSELECP		0x08	/* inverted output, active low */
#define PNL_PINITP		0x04	/* direct output, active low */
#define PNL_PAUTOLF		0x02	/* inverted output, active low */
#define PNL_PSTROBE		0x01	/* inverted output */

#define PNL_PD0			0x01
#define PNL_PD1			0x02
#define PNL_PD2			0x04
#define PNL_PD3			0x08
#define PNL_PD4			0x10
#define PNL_PD5			0x20
#define PNL_PD6			0x40
#define PNL_PD7			0x80

#define PIN_NONE		0
#define PIN_STROBE		1
#define PIN_D0			2
#define PIN_D1			3
#define PIN_D2			4
#define PIN_D3			5
#define PIN_D4			6
#define PIN_D5			7
#define PIN_D6			8
#define PIN_D7			9
#define PIN_AUTOLF		14
#define PIN_INITP		16
#define PIN_SELECP		17
#define PIN_NOT_SET		127

#define NOT_SET			-1

/* macros to simplify use of the parallel port */
#define r_ctr(x)        (parport_read_control((x)->port))
#define r_dtr(x)        (parport_read_data((x)->port))
#define r_str(x)        (parport_read_status((x)->port))
#define w_ctr(x, y)     (parport_write_control((x)->port, (y)))
#define w_dtr(x, y)     (parport_write_data((x)->port, (y)))

/* this defines which bits are to be used and which ones to be ignored */
/* logical or of the output bits involved in the scan matrix */
static __u8 scan_mask_o;
/* logical or of the input bits involved in the scan matrix */
static __u8 scan_mask_i;

enum input_type {
	INPUT_TYPE_STD,
	INPUT_TYPE_KBD,
};

enum input_state {
	INPUT_ST_LOW,
	INPUT_ST_RISING,
	INPUT_ST_HIGH,
	INPUT_ST_FALLING,
};

struct logical_input {
	struct list_head list;
	__u64 mask;
	__u64 value;
	enum input_type type;
	enum input_state state;
	__u8 rise_time, fall_time;
	__u8 rise_timer, fall_timer, high_timer;

	union {
		struct {	/* valid when type == INPUT_TYPE_STD */
			void (*press_fct)(int);
			void (*release_fct)(int);
			int press_data;
			int release_data;
		} std;
		struct {	/* valid when type == INPUT_TYPE_KBD */
			char press_str[sizeof(void *) + sizeof(int)] __nonstring;
			char repeat_str[sizeof(void *) + sizeof(int)] __nonstring;
			char release_str[sizeof(void *) + sizeof(int)] __nonstring;
		} kbd;
	} u;
};

static LIST_HEAD(logical_inputs);	/* list of all defined logical inputs */

/* physical contacts history
 * Physical contacts are a 45 bits string of 9 groups of 5 bits each.
 * The 8 lower groups correspond to output bits 0 to 7, and the 9th group
 * corresponds to the ground.
 * Within each group, bits are stored in the same order as read on the port :
 * BAPSE (busy=4, ack=3, paper empty=2, select=1, error=0).
 * So, each __u64 is represented like this :
 * 0000000000000000000BAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSE
 * <-----unused------><gnd><d07><d06><d05><d04><d03><d02><d01><d00>
 */

/* what has just been read from the I/O ports */
static __u64 phys_read;
/* previous phys_read */
static __u64 phys_read_prev;
/* stabilized phys_read (phys_read|phys_read_prev) */
static __u64 phys_curr;
/* previous phys_curr */
static __u64 phys_prev;
/* 0 means that at least one logical signal needs be computed */
static char inputs_stable;

/* these variables are specific to the keypad */
static struct {
	bool enabled;
} keypad;

static char keypad_buffer[KEYPAD_BUFFER];
static int keypad_buflen;
static int keypad_start;
static char keypressed;
static wait_queue_head_t keypad_read_wait;

/* lcd-specific variables */
static struct {
	bool enabled;
	bool initialized;

	int charset;
	int proto;

	/* TODO: use union here? */
	struct {
		int e;
		int rs;
		int rw;
		int cl;
		int da;
		int bl;
	} pins;

	struct charlcd *charlcd;
} lcd;

/* Needed only for init */
static int selected_lcd_type = NOT_SET;

/*
 * Bit masks to convert LCD signals to parallel port outputs.
 * _d_ are values for data port, _c_ are for control port.
 * [0] = signal OFF, [1] = signal ON, [2] = mask
 */
#define BIT_CLR		0
#define BIT_SET		1
#define BIT_MSK		2
#define BIT_STATES	3
/*
 * one entry for each bit on the LCD
 */
#define LCD_BIT_E	0
#define LCD_BIT_RS	1
#define LCD_BIT_RW	2
#define LCD_BIT_BL	3
#define LCD_BIT_CL	4
#define LCD_BIT_DA	5
#define LCD_BITS	6

/*
 * each bit can be either connected to a DATA or CTRL port
 */
#define LCD_PORT_C	0
#define LCD_PORT_D	1
#define LCD_PORTS	2

static unsigned char lcd_bits[LCD_PORTS][LCD_BITS][BIT_STATES];

/*
 * LCD protocols
 */
#define LCD_PROTO_PARALLEL      0
#define LCD_PROTO_SERIAL        1
#define LCD_PROTO_TI_DA8XX_LCD	2

/*
 * LCD character sets
 */
#define LCD_CHARSET_NORMAL      0
#define LCD_CHARSET_KS0074      1

/*
 * LCD types
 */
#define LCD_TYPE_NONE		0
#define LCD_TYPE_CUSTOM		1
#define LCD_TYPE_OLD		2
#define LCD_TYPE_KS0074		3
#define LCD_TYPE_HANTRONIX	4
#define LCD_TYPE_NEXCOM		5

/*
 * keypad types
 */
#define KEYPAD_TYPE_NONE	0
#define KEYPAD_TYPE_OLD		1
#define KEYPAD_TYPE_NEW		2
#define KEYPAD_TYPE_NEXCOM	3

/*
 * panel profiles
 */
#define PANEL_PROFILE_CUSTOM	0
#define PANEL_PROFILE_OLD	1
#define PANEL_PROFILE_NEW	2
#define PANEL_PROFILE_HANTRONIX	3
#define PANEL_PROFILE_NEXCOM	4
#define PANEL_PROFILE_LARGE	5

/*
 * Construct custom config from the kernel's configuration
 */
#define DEFAULT_PARPORT         0
#define DEFAULT_PROFILE         PANEL_PROFILE_LARGE
#define DEFAULT_KEYPAD_TYPE     KEYPAD_TYPE_OLD
#define DEFAULT_LCD_TYPE        LCD_TYPE_OLD
#define DEFAULT_LCD_HEIGHT      2
#define DEFAULT_LCD_WIDTH       40
#define DEFAULT_LCD_BWIDTH      40
#define DEFAULT_LCD_HWIDTH      64
#define DEFAULT_LCD_CHARSET     LCD_CHARSET_NORMAL
#define DEFAULT_LCD_PROTO       LCD_PROTO_PARALLEL

#define DEFAULT_LCD_PIN_E       PIN_AUTOLF
#define DEFAULT_LCD_PIN_RS      PIN_SELECP
#define DEFAULT_LCD_PIN_RW      PIN_INITP
#define DEFAULT_LCD_PIN_SCL     PIN_STROBE
#define DEFAULT_LCD_PIN_SDA     PIN_D0
#define DEFAULT_LCD_PIN_BL      PIN_NOT_SET

#ifdef CONFIG_PANEL_PARPORT
#undef DEFAULT_PARPORT
#define DEFAULT_PARPORT CONFIG_PANEL_PARPORT
#endif

#ifdef CONFIG_PANEL_PROFILE
#undef DEFAULT_PROFILE
#define DEFAULT_PROFILE CONFIG_PANEL_PROFILE
#endif

#if DEFAULT_PROFILE == 0	/* custom */
#ifdef CONFIG_PANEL_KEYPAD
#undef DEFAULT_KEYPAD_TYPE
#define DEFAULT_KEYPAD_TYPE CONFIG_PANEL_KEYPAD
#endif

#ifdef CONFIG_PANEL_LCD
#undef DEFAULT_LCD_TYPE
#define DEFAULT_LCD_TYPE CONFIG_PANEL_LCD
#endif

#ifdef CONFIG_PANEL_LCD_HEIGHT
#undef DEFAULT_LCD_HEIGHT
#define DEFAULT_LCD_HEIGHT CONFIG_PANEL_LCD_HEIGHT
#endif

#ifdef CONFIG_PANEL_LCD_WIDTH
#undef DEFAULT_LCD_WIDTH
#define DEFAULT_LCD_WIDTH CONFIG_PANEL_LCD_WIDTH
#endif

#ifdef CONFIG_PANEL_LCD_BWIDTH
#undef DEFAULT_LCD_BWIDTH
#define DEFAULT_LCD_BWIDTH CONFIG_PANEL_LCD_BWIDTH
#endif

#ifdef CONFIG_PANEL_LCD_HWIDTH
#undef DEFAULT_LCD_HWIDTH
#define DEFAULT_LCD_HWIDTH CONFIG_PANEL_LCD_HWIDTH
#endif

#ifdef CONFIG_PANEL_LCD_CHARSET
#undef DEFAULT_LCD_CHARSET
#define DEFAULT_LCD_CHARSET CONFIG_PANEL_LCD_CHARSET
#endif

#ifdef CONFIG_PANEL_LCD_PROTO
#undef DEFAULT_LCD_PROTO
#define DEFAULT_LCD_PROTO CONFIG_PANEL_LCD_PROTO
#endif

#ifdef CONFIG_PANEL_LCD_PIN_E
#undef DEFAULT_LCD_PIN_E
#define DEFAULT_LCD_PIN_E CONFIG_PANEL_LCD_PIN_E
#endif

#ifdef CONFIG_PANEL_LCD_PIN_RS
#undef DEFAULT_LCD_PIN_RS
#define DEFAULT_LCD_PIN_RS CONFIG_PANEL_LCD_PIN_RS
#endif

#ifdef CONFIG_PANEL_LCD_PIN_RW
#undef DEFAULT_LCD_PIN_RW
#define DEFAULT_LCD_PIN_RW CONFIG_PANEL_LCD_PIN_RW
#endif

#ifdef CONFIG_PANEL_LCD_PIN_SCL
#undef DEFAULT_LCD_PIN_SCL
#define DEFAULT_LCD_PIN_SCL CONFIG_PANEL_LCD_PIN_SCL
#endif

#ifdef CONFIG_PANEL_LCD_PIN_SDA
#undef DEFAULT_LCD_PIN_SDA
#define DEFAULT_LCD_PIN_SDA CONFIG_PANEL_LCD_PIN_SDA
#endif

#ifdef CONFIG_PANEL_LCD_PIN_BL
#undef DEFAULT_LCD_PIN_BL
#define DEFAULT_LCD_PIN_BL CONFIG_PANEL_LCD_PIN_BL
#endif

#endif /* DEFAULT_PROFILE == 0 */

/* global variables */

/* Device single-open policy control */
static atomic_t keypad_available = ATOMIC_INIT(1);

static struct pardevice *pprt;

static int keypad_initialized;

static DEFINE_SPINLOCK(pprt_lock);
static struct timer_list scan_timer;

MODULE_DESCRIPTION("Generic parallel port LCD/Keypad driver");

static int parport = DEFAULT_PARPORT;
module_param(parport, int, 0000);
MODULE_PARM_DESC(parport, "Parallel port index (0=lpt1, 1=lpt2, ...)");

static int profile = DEFAULT_PROFILE;
module_param(profile, int, 0000);
MODULE_PARM_DESC(profile,
		 "1=16x2 old kp; 2=serial 16x2, new kp; 3=16x2 hantronix; "
		 "4=16x2 nexcom; default=40x2, old kp");

static int keypad_type = NOT_SET;
module_param(keypad_type, int, 0000);
MODULE_PARM_DESC(keypad_type,
		 "Keypad type: 0=none, 1=old 6 keys, 2=new 6+1 keys, 3=nexcom 4 keys");

static int lcd_type = NOT_SET;
module_param(lcd_type, int, 0000);
MODULE_PARM_DESC(lcd_type,
		 "LCD type: 0=none, 1=compiled-in, 2=old, 3=serial ks0074, 4=hantronix, 5=nexcom");

static int lcd_height = NOT_SET;
module_param(lcd_height, int, 0000);
MODULE_PARM_DESC(lcd_height, "Number of lines on the LCD");

static int lcd_width = NOT_SET;
module_param(lcd_width, int, 0000);
MODULE_PARM_DESC(lcd_width, "Number of columns on the LCD");

static int lcd_bwidth = NOT_SET;	/* internal buffer width (usually 40) */
module_param(lcd_bwidth, int, 0000);
MODULE_PARM_DESC(lcd_bwidth, "Internal LCD line width (40)");

static int lcd_hwidth = NOT_SET;	/* hardware buffer width (usually 64) */
module_param(lcd_hwidth, int, 0000);
MODULE_PARM_DESC(lcd_hwidth, "LCD line hardware address (64)");

static int lcd_charset = NOT_SET;
module_param(lcd_charset, int, 0000);
MODULE_PARM_DESC(lcd_charset, "LCD character set: 0=standard, 1=KS0074");

static int lcd_proto = NOT_SET;
module_param(lcd_proto, int, 0000);
MODULE_PARM_DESC(lcd_proto,
		 "LCD communication: 0=parallel (//), 1=serial, 2=TI LCD Interface");

/*
 * These are the parallel port pins the LCD control signals are connected to.
 * Set this to 0 if the signal is not used. Set it to its opposite value
 * (negative) if the signal is negated. -MAXINT is used to indicate that the
 * pin has not been explicitly specified.
 *
 * WARNING! no check will be performed about collisions with keypad !
 */

static int lcd_e_pin  = PIN_NOT_SET;
module_param(lcd_e_pin, int, 0000);
MODULE_PARM_DESC(lcd_e_pin,
		 "# of the // port pin connected to LCD 'E' signal, with polarity (-17..17)");

static int lcd_rs_pin = PIN_NOT_SET;
module_param(lcd_rs_pin, int, 0000);
MODULE_PARM_DESC(lcd_rs_pin,
		 "# of the // port pin connected to LCD 'RS' signal, with polarity (-17..17)");

static int lcd_rw_pin = PIN_NOT_SET;
module_param(lcd_rw_pin, int, 0000);
MODULE_PARM_DESC(lcd_rw_pin,
		 "# of the // port pin connected to LCD 'RW' signal, with polarity (-17..17)");

static int lcd_cl_pin = PIN_NOT_SET;
module_param(lcd_cl_pin, int, 0000);
MODULE_PARM_DESC(lcd_cl_pin,
		 "# of the // port pin connected to serial LCD 'SCL' signal, with polarity (-17..17)");

static int lcd_da_pin = PIN_NOT_SET;
module_param(lcd_da_pin, int, 0000);
MODULE_PARM_DESC(lcd_da_pin,
		 "# of the // port pin connected to serial LCD 'SDA' signal, with polarity (-17..17)");

static int lcd_bl_pin = PIN_NOT_SET;
module_param(lcd_bl_pin, int, 0000);
MODULE_PARM_DESC(lcd_bl_pin,
		 "# of the // port pin connected to LCD backlight, with polarity (-17..17)");

/* Deprecated module parameters - consider not using them anymore */

static int lcd_enabled = NOT_SET;
module_param(lcd_enabled, int, 0000);
MODULE_PARM_DESC(lcd_enabled, "Deprecated option, use lcd_type instead");

static int keypad_enabled = NOT_SET;
module_param(keypad_enabled, int, 0000);
MODULE_PARM_DESC(keypad_enabled, "Deprecated option, use keypad_type instead");

/* for some LCD drivers (ks0074) we need a charset conversion table. */
static const unsigned char lcd_char_conv_ks0074[256] = {
	/*          0|8   1|9   2|A   3|B   4|C   5|D   6|E   7|F */
	/* 0x00 */ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
	/* 0x08 */ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
	/* 0x10 */ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
	/* 0x18 */ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
	/* 0x20 */ 0x20, 0x21, 0x22, 0x23, 0xa2, 0x25, 0x26, 0x27,
	/* 0x28 */ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	/* 0x30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	/* 0x38 */ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	/* 0x40 */ 0xa0, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	/* 0x48 */ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	/* 0x50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
	/* 0x58 */ 0x58, 0x59, 0x5a, 0xfa, 0xfb, 0xfc, 0x1d, 0xc4,
	/* 0x60 */ 0x96, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	/* 0x68 */ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	/* 0x70 */ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
	/* 0x78 */ 0x78, 0x79, 0x7a, 0xfd, 0xfe, 0xff, 0xce, 0x20,
	/* 0x80 */ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
	/* 0x88 */ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
	/* 0x90 */ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
	/* 0x98 */ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
	/* 0xA0 */ 0x20, 0x40, 0xb1, 0xa1, 0x24, 0xa3, 0xfe, 0x5f,
	/* 0xA8 */ 0x22, 0xc8, 0x61, 0x14, 0x97, 0x2d, 0xad, 0x96,
	/* 0xB0 */ 0x80, 0x8c, 0x82, 0x83, 0x27, 0x8f, 0x86, 0xdd,
	/* 0xB8 */ 0x2c, 0x81, 0x6f, 0x15, 0x8b, 0x8a, 0x84, 0x60,
	/* 0xC0 */ 0xe2, 0xe2, 0xe2, 0x5b, 0x5b, 0xae, 0xbc, 0xa9,
	/* 0xC8 */ 0xc5, 0xbf, 0xc6, 0xf1, 0xe3, 0xe3, 0xe3, 0xe3,
	/* 0xD0 */ 0x44, 0x5d, 0xa8, 0xe4, 0xec, 0xec, 0x5c, 0x78,
	/* 0xD8 */ 0xab, 0xa6, 0xe5, 0x5e, 0x5e, 0xe6, 0xaa, 0xbe,
	/* 0xE0 */ 0x7f, 0xe7, 0xaf, 0x7b, 0x7b, 0xaf, 0xbd, 0xc8,
	/* 0xE8 */ 0xa4, 0xa5, 0xc7, 0xf6, 0xa7, 0xe8, 0x69, 0x69,
	/* 0xF0 */ 0xed, 0x7d, 0xa8, 0xe4, 0xec, 0x5c, 0x5c, 0x25,
	/* 0xF8 */ 0xac, 0xa6, 0xea, 0xef, 0x7e, 0xeb, 0xb2, 0x79,
};

static const char old_keypad_profile[][4][9] = {
	{"S0", "Left\n", "Left\n", ""},
	{"S1", "Down\n", "Down\n", ""},
	{"S2", "Up\n", "Up\n", ""},
	{"S3", "Right\n", "Right\n", ""},
	{"S4", "Esc\n", "Esc\n", ""},
	{"S5", "Ret\n", "Ret\n", ""},
	{"", "", "", ""}
};

/* signals, press, repeat, release */
static const char new_keypad_profile[][4][9] = {
	{"S0", "Left\n", "Left\n", ""},
	{"S1", "Down\n", "Down\n", ""},
	{"S2", "Up\n", "Up\n", ""},
	{"S3", "Right\n", "Right\n", ""},
	{"S4s5", "", "Esc\n", "Esc\n"},
	{"s4S5", "", "Ret\n", "Ret\n"},
	{"S4S5", "Help\n", "", ""},
	/* add new signals above this line */
	{"", "", "", ""}
};

/* signals, press, repeat, release */
static const char nexcom_keypad_profile[][4][9] = {
	{"a-p-e-", "Down\n", "Down\n", ""},
	{"a-p-E-", "Ret\n", "Ret\n", ""},
	{"a-P-E-", "Esc\n", "Esc\n", ""},
	{"a-P-e-", "Up\n", "Up\n", ""},
	/* add new signals above this line */
	{"", "", "", ""}
};

static const char (*keypad_profile)[4][9] = old_keypad_profile;

static DECLARE_BITMAP(bits, LCD_BITS);

static void lcd_get_bits(unsigned int port, int *val)
{
	unsigned int bit, state;

	for (bit = 0; bit < LCD_BITS; bit++) {
		state = test_bit(bit, bits) ? BIT_SET : BIT_CLR;
		*val &= lcd_bits[port][bit][BIT_MSK];
		*val |= lcd_bits[port][bit][state];
	}
}

/* sets data port bits according to current signals values */
static int set_data_bits(void)
{
	int val;

	val = r_dtr(pprt);
	lcd_get_bits(LCD_PORT_D, &val);
	w_dtr(pprt, val);
	return val;
}

/* sets ctrl port bits according to current signals values */
static int set_ctrl_bits(void)
{
	int val;

	val = r_ctr(pprt);
	lcd_get_bits(LCD_PORT_C, &val);
	w_ctr(pprt, val);
	return val;
}

/* sets ctrl & data port bits according to current signals values */
static void panel_set_bits(void)
{
	set_data_bits();
	set_ctrl_bits();
}

/*
 * Converts a parallel port pin (from -25 to 25) to data and control ports
 * masks, and data and control port bits. The signal will be considered
 * unconnected if it's on pin 0 or an invalid pin (<-25 or >25).
 *
 * Result will be used this way :
 *   out(dport, in(dport) & d_val[2] | d_val[signal_state])
 *   out(cport, in(cport) & c_val[2] | c_val[signal_state])
 */
static void pin_to_bits(int pin, unsigned char *d_val, unsigned char *c_val)
{
	int d_bit, c_bit, inv;

	d_val[0] = 0;
	c_val[0] = 0;
	d_val[1] = 0;
	c_val[1] = 0;
	d_val[2] = 0xFF;
	c_val[2] = 0xFF;

	if (pin == 0)
		return;

	inv = (pin < 0);
	if (inv)
		pin = -pin;

	d_bit = 0;
	c_bit = 0;

	switch (pin) {
	case PIN_STROBE:	/* strobe, inverted */
		c_bit = PNL_PSTROBE;
		inv = !inv;
		break;
	case PIN_D0...PIN_D7:	/* D0 - D7 = 2 - 9 */
		d_bit = 1 << (pin - 2);
		break;
	case PIN_AUTOLF:	/* autofeed, inverted */
		c_bit = PNL_PAUTOLF;
		inv = !inv;
		break;
	case PIN_INITP:		/* init, direct */
		c_bit = PNL_PINITP;
		break;
	case PIN_SELECP:	/* select_in, inverted */
		c_bit = PNL_PSELECP;
		inv = !inv;
		break;
	default:		/* unknown pin, ignore */
		break;
	}

	if (c_bit) {
		c_val[2] &= ~c_bit;
		c_val[!inv] = c_bit;
	} else if (d_bit) {
		d_val[2] &= ~d_bit;
		d_val[!inv] = d_bit;
	}
}

/*
 * send a serial byte to the LCD panel. The caller is responsible for locking
 * if needed.
 */
static void lcd_send_serial(int byte)
{
	int bit;

	/*
	 * the data bit is set on D0, and the clock on STROBE.
	 * LCD reads D0 on STROBE's rising edge.
	 */
	for (bit = 0; bit < 8; bit++) {
		clear_bit(LCD_BIT_CL, bits);	/* CLK low */
		panel_set_bits();
		if (byte & 1) {
			set_bit(LCD_BIT_DA, bits);
		} else {
			clear_bit(LCD_BIT_DA, bits);
		}

		panel_set_bits();
		udelay(2);  /* maintain the data during 2 us before CLK up */
		set_bit(LCD_BIT_CL, bits);	/* CLK high */
		panel_set_bits();
		udelay(1);  /* maintain the strobe during 1 us */
		byte >>= 1;
	}
}

/* turn the backlight on or off */
static void lcd_backlight(struct charlcd *charlcd, int on)
{
	if (lcd.pins.bl == PIN_NONE)
		return;

	/* The backlight is activated by setting the AUTOFEED line to +5V  */
	spin_lock_irq(&pprt_lock);
	if (on)
		set_bit(LCD_BIT_BL, bits);
	else
		clear_bit(LCD_BIT_BL, bits);
	panel_set_bits();
	spin_unlock_irq(&pprt_lock);
}

/* send a command to the LCD panel in serial mode */
static void lcd_write_cmd_s(struct charlcd *charlcd, int cmd)
{
	spin_lock_irq(&pprt_lock);
	lcd_send_serial(0x1F);	/* R/W=W, RS=0 */
	lcd_send_serial(cmd & 0x0F);
	lcd_send_serial((cmd >> 4) & 0x0F);
	udelay(40);		/* the shortest command takes at least 40 us */
	spin_unlock_irq(&pprt_lock);
}

/* send data to the LCD panel in serial mode */
static void lcd_write_data_s(struct charlcd *charlcd, int data)
{
	spin_lock_irq(&pprt_lock);
	lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
	lcd_send_serial(data & 0x0F);
	lcd_send_serial((data >> 4) & 0x0F);
	udelay(40);		/* the shortest data takes at least 40 us */
	spin_unlock_irq(&pprt_lock);
}

/* send a command to the LCD panel in 8 bits parallel mode */
static void lcd_write_cmd_p8(struct charlcd *charlcd, int cmd)
{
	spin_lock_irq(&pprt_lock);
	/* present the data to the data port */
	w_dtr(pprt, cmd);
	udelay(20);	/* maintain the data during 20 us before the strobe */

	set_bit(LCD_BIT_E, bits);
	clear_bit(LCD_BIT_RS, bits);
	clear_bit(LCD_BIT_RW, bits);
	set_ctrl_bits();

	udelay(40);	/* maintain the strobe during 40 us */

	clear_bit(LCD_BIT_E, bits);
	set_ctrl_bits();

	udelay(120);	/* the shortest command takes at least 120 us */
	spin_unlock_irq(&pprt_lock);
}

/* send data to the LCD panel in 8 bits parallel mode */
static void lcd_write_data_p8(struct charlcd *charlcd, int data)
{
	spin_lock_irq(&pprt_lock);
	/* present the data to the data port */
	w_dtr(pprt, data);
	udelay(20);	/* maintain the data during 20 us before the strobe */

	set_bit(LCD_BIT_E, bits);
	set_bit(LCD_BIT_RS, bits);
	clear_bit(LCD_BIT_RW, bits);
	set_ctrl_bits();

	udelay(40);	/* maintain the strobe during 40 us */

	clear_bit(LCD_BIT_E, bits);
	set_ctrl_bits();

	udelay(45);	/* the shortest data takes at least 45 us */
	spin_unlock_irq(&pprt_lock);
}

/* send a command to the TI LCD panel */
static void lcd_write_cmd_tilcd(struct charlcd *charlcd, int cmd)
{
	spin_lock_irq(&pprt_lock);
	/* present the data to the control port */
	w_ctr(pprt, cmd);
	udelay(60);
	spin_unlock_irq(&pprt_lock);
}

/* send data to the TI LCD panel */
static void lcd_write_data_tilcd(struct charlcd *charlcd, int data)
{
	spin_lock_irq(&pprt_lock);
	/* present the data to the data port */
	w_dtr(pprt, data);
	udelay(60);
	spin_unlock_irq(&pprt_lock);
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_s(struct charlcd *charlcd)
{
	int pos;

	spin_lock_irq(&pprt_lock);
	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
		lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
		lcd_send_serial(' ' & 0x0F);
		lcd_send_serial((' ' >> 4) & 0x0F);
		/* the shortest data takes at least 40 us */
		udelay(40);
	}
	spin_unlock_irq(&pprt_lock);
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_p8(struct charlcd *charlcd)
{
	int pos;

	spin_lock_irq(&pprt_lock);
	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
		/* present the data to the data port */
		w_dtr(pprt, ' ');

		/* maintain the data during 20 us before the strobe */
		udelay(20);

		set_bit(LCD_BIT_E, bits);
		set_bit(LCD_BIT_RS, bits);
		clear_bit(LCD_BIT_RW, bits);
		set_ctrl_bits();

		/* maintain the strobe during 40 us */
		udelay(40);

		clear_bit(LCD_BIT_E, bits);
		set_ctrl_bits();

		/* the shortest data takes at least 45 us */
		udelay(45);
	}
	spin_unlock_irq(&pprt_lock);
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
{
	int pos;

	spin_lock_irq(&pprt_lock);
	for (pos = 0; pos < charlcd->height * charlcd->hwidth; pos++) {
		/* present the data to the data port */
		w_dtr(pprt, ' ');
		udelay(60);
	}

	spin_unlock_irq(&pprt_lock);
}

static const struct charlcd_ops charlcd_serial_ops = {
	.write_cmd	= lcd_write_cmd_s,
	.write_data	= lcd_write_data_s,
	.clear_fast	= lcd_clear_fast_s,
	.backlight	= lcd_backlight,
};

static const struct charlcd_ops charlcd_parallel_ops = {
	.write_cmd	= lcd_write_cmd_p8,
	.write_data	= lcd_write_data_p8,
	.clear_fast	= lcd_clear_fast_p8,
	.backlight	= lcd_backlight,
};

static const struct charlcd_ops charlcd_tilcd_ops = {
	.write_cmd	= lcd_write_cmd_tilcd,
	.write_data	= lcd_write_data_tilcd,
	.clear_fast	= lcd_clear_fast_tilcd,
	.backlight	= lcd_backlight,
};

/* initialize the LCD driver */
static void lcd_init(void)
{
	struct charlcd *charlcd;

	charlcd = charlcd_alloc(0);
	if (!charlcd)
		return;

	/*
	 * Init lcd struct with load-time values to preserve exact
	 * current functionality (at least for now).
	 */
	charlcd->height = lcd_height;
	charlcd->width = lcd_width;
	charlcd->bwidth = lcd_bwidth;
	charlcd->hwidth = lcd_hwidth;

	switch (selected_lcd_type) {
	case LCD_TYPE_OLD:
		/* parallel mode, 8 bits */
		lcd.proto = LCD_PROTO_PARALLEL;
		lcd.charset = LCD_CHARSET_NORMAL;
		lcd.pins.e = PIN_STROBE;
		lcd.pins.rs = PIN_AUTOLF;

		charlcd->width = 40;
		charlcd->bwidth = 40;
		charlcd->hwidth = 64;
		charlcd->height = 2;
		break;
	case LCD_TYPE_KS0074:
		/* serial mode, ks0074 */
		lcd.proto = LCD_PROTO_SERIAL;
		lcd.charset = LCD_CHARSET_KS0074;
		lcd.pins.bl = PIN_AUTOLF;
		lcd.pins.cl = PIN_STROBE;
		lcd.pins.da = PIN_D0;

		charlcd->width = 16;
		charlcd->bwidth = 40;
		charlcd->hwidth = 16;
		charlcd->height = 2;
		break;
	case LCD_TYPE_NEXCOM:
		/* parallel mode, 8 bits, generic */
		lcd.proto = LCD_PROTO_PARALLEL;
		lcd.charset = LCD_CHARSET_NORMAL;
		lcd.pins.e = PIN_AUTOLF;
		lcd.pins.rs = PIN_SELECP;
		lcd.pins.rw = PIN_INITP;

		charlcd->width = 16;
		charlcd->bwidth = 40;
		charlcd->hwidth = 64;
		charlcd->height = 2;
		break;
	case LCD_TYPE_CUSTOM:
		/* customer-defined */
		lcd.proto = DEFAULT_LCD_PROTO;
		lcd.charset = DEFAULT_LCD_CHARSET;
		/* default geometry will be set later */
		break;
	case LCD_TYPE_HANTRONIX:
		/* parallel mode, 8 bits, hantronix-like */
	default:
		lcd.proto = LCD_PROTO_PARALLEL;
		lcd.charset = LCD_CHARSET_NORMAL;
		lcd.pins.e = PIN_STROBE;
		lcd.pins.rs = PIN_SELECP;

		charlcd->width = 16;
		charlcd->bwidth = 40;
		charlcd->hwidth = 64;
		charlcd->height = 2;
		break;
	}

	/* Overwrite with module params set on loading */
	if (lcd_height != NOT_SET)
		charlcd->height = lcd_height;
	if (lcd_width != NOT_SET)
		charlcd->width = lcd_width;
	if (lcd_bwidth != NOT_SET)
		charlcd->bwidth = lcd_bwidth;
	if (lcd_hwidth != NOT_SET)
		charlcd->hwidth = lcd_hwidth;
	if (lcd_charset != NOT_SET)
		lcd.charset = lcd_charset;
	if (lcd_proto != NOT_SET)
		lcd.proto = lcd_proto;
	if (lcd_e_pin != PIN_NOT_SET)
		lcd.pins.e = lcd_e_pin;
	if (lcd_rs_pin != PIN_NOT_SET)
		lcd.pins.rs = lcd_rs_pin;
	if (lcd_rw_pin != PIN_NOT_SET)
		lcd.pins.rw = lcd_rw_pin;
	if (lcd_cl_pin != PIN_NOT_SET)
		lcd.pins.cl = lcd_cl_pin;
	if (lcd_da_pin != PIN_NOT_SET)
		lcd.pins.da = lcd_da_pin;
	if (lcd_bl_pin != PIN_NOT_SET)
		lcd.pins.bl = lcd_bl_pin;

	/* this is used to catch wrong and default values */
	if (charlcd->width <= 0)
		charlcd->width = DEFAULT_LCD_WIDTH;
	if (charlcd->bwidth <= 0)
		charlcd->bwidth = DEFAULT_LCD_BWIDTH;
	if (charlcd->hwidth <= 0)
		charlcd->hwidth = DEFAULT_LCD_HWIDTH;
	if (charlcd->height <= 0)
		charlcd->height = DEFAULT_LCD_HEIGHT;

	if (lcd.proto == LCD_PROTO_SERIAL) {	/* SERIAL */
		charlcd->ops = &charlcd_serial_ops;

		if (lcd.pins.cl == PIN_NOT_SET)
			lcd.pins.cl = DEFAULT_LCD_PIN_SCL;
		if (lcd.pins.da == PIN_NOT_SET)
			lcd.pins.da = DEFAULT_LCD_PIN_SDA;

	} else if (lcd.proto == LCD_PROTO_PARALLEL) {	/* PARALLEL */
		charlcd->ops = &charlcd_parallel_ops;

		if (lcd.pins.e == PIN_NOT_SET)
			lcd.pins.e = DEFAULT_LCD_PIN_E;
		if (lcd.pins.rs == PIN_NOT_SET)
			lcd.pins.rs = DEFAULT_LCD_PIN_RS;
		if (lcd.pins.rw == PIN_NOT_SET)
			lcd.pins.rw = DEFAULT_LCD_PIN_RW;
	} else {
		charlcd->ops = &charlcd_tilcd_ops;
	}

	if (lcd.pins.bl == PIN_NOT_SET)
		lcd.pins.bl = DEFAULT_LCD_PIN_BL;

	if (lcd.pins.e == PIN_NOT_SET)
		lcd.pins.e = PIN_NONE;
	if (lcd.pins.rs == PIN_NOT_SET)
		lcd.pins.rs = PIN_NONE;
	if (lcd.pins.rw == PIN_NOT_SET)
		lcd.pins.rw = PIN_NONE;
	if (lcd.pins.bl == PIN_NOT_SET)
		lcd.pins.bl = PIN_NONE;
	if (lcd.pins.cl == PIN_NOT_SET)
		lcd.pins.cl = PIN_NONE;
	if (lcd.pins.da == PIN_NOT_SET)
		lcd.pins.da = PIN_NONE;

	if (lcd.charset == NOT_SET)
		lcd.charset = DEFAULT_LCD_CHARSET;

	if (lcd.charset == LCD_CHARSET_KS0074)
		charlcd->char_conv = lcd_char_conv_ks0074;
	else
		charlcd->char_conv = NULL;

	pin_to_bits(lcd.pins.e, lcd_bits[LCD_PORT_D][LCD_BIT_E],
		    lcd_bits[LCD_PORT_C][LCD_BIT_E]);
	pin_to_bits(lcd.pins.rs, lcd_bits[LCD_PORT_D][LCD_BIT_RS],
		    lcd_bits[LCD_PORT_C][LCD_BIT_RS]);
	pin_to_bits(lcd.pins.rw, lcd_bits[LCD_PORT_D][LCD_BIT_RW],
		    lcd_bits[LCD_PORT_C][LCD_BIT_RW]);
	pin_to_bits(lcd.pins.bl, lcd_bits[LCD_PORT_D][LCD_BIT_BL],
		    lcd_bits[LCD_PORT_C][LCD_BIT_BL]);
	pin_to_bits(lcd.pins.cl, lcd_bits[LCD_PORT_D][LCD_BIT_CL],
		    lcd_bits[LCD_PORT_C][LCD_BIT_CL]);
	pin_to_bits(lcd.pins.da, lcd_bits[LCD_PORT_D][LCD_BIT_DA],
		    lcd_bits[LCD_PORT_C][LCD_BIT_DA]);

	lcd.charlcd = charlcd;
	lcd.initialized = true;
}

/*
 * These are the file operation function for user access to /dev/keypad
 */

static ssize_t keypad_read(struct file *file,
			   char __user *buf, size_t count, loff_t *ppos)
{
	unsigned i = *ppos;
	char __user *tmp = buf;

	if (keypad_buflen == 0) {
		if (file->f_flags & O_NONBLOCK)
			return -EAGAIN;

		if (wait_event_interruptible(keypad_read_wait,
					     keypad_buflen != 0))
			return -EINTR;
	}

	for (; count-- > 0 && (keypad_buflen > 0);
	     ++i, ++tmp, --keypad_buflen) {
		put_user(keypad_buffer[keypad_start], tmp);
		keypad_start = (keypad_start + 1) % KEYPAD_BUFFER;
	}
	*ppos = i;

	return tmp - buf;
}

static int keypad_open(struct inode *inode, struct file *file)
{
	int ret;

	ret = -EBUSY;
	if (!atomic_dec_and_test(&keypad_available))
		goto fail;	/* open only once at a time */

	ret = -EPERM;
	if (file->f_mode & FMODE_WRITE)	/* device is read-only */
		goto fail;

	keypad_buflen = 0;	/* flush the buffer on opening */
	return 0;
 fail:
	atomic_inc(&keypad_available);
	return ret;
}

static int keypad_release(struct inode *inode, struct file *file)
{
	atomic_inc(&keypad_available);
	return 0;
}

static const struct file_operations keypad_fops = {
	.read    = keypad_read,		/* read */
	.open    = keypad_open,		/* open */
	.release = keypad_release,	/* close */
	.llseek  = default_llseek,
};

static struct miscdevice keypad_dev = {
	.minor	= KEYPAD_MINOR,
	.name	= "keypad",
	.fops	= &keypad_fops,
};

static void keypad_send_key(const char *string, int max_len)
{
	/* send the key to the device only if a process is attached to it. */
	if (!atomic_read(&keypad_available)) {
		while (max_len-- && keypad_buflen < KEYPAD_BUFFER && *string) {
			keypad_buffer[(keypad_start + keypad_buflen++) %
				      KEYPAD_BUFFER] = *string++;
		}
		wake_up_interruptible(&keypad_read_wait);
	}
}

/* this function scans all the bits involving at least one logical signal,
 * and puts the results in the bitfield "phys_read" (one bit per established
 * contact), and sets "phys_read_prev" to "phys_read".
 *
 * Note: to debounce input signals, we will only consider as switched a signal
 * which is stable across 2 measures. Signals which are different between two
 * reads will be kept as they previously were in their logical form (phys_prev).
 * A signal which has just switched will have a 1 in
 * (phys_read ^ phys_read_prev).
 */
static void phys_scan_contacts(void)
{
	int bit, bitval;
	char oldval;
	char bitmask;
	char gndmask;

	phys_prev = phys_curr;
	phys_read_prev = phys_read;
	phys_read = 0;		/* flush all signals */

	/* keep track of old value, with all outputs disabled */
	oldval = r_dtr(pprt) | scan_mask_o;
	/* activate all keyboard outputs (active low) */
	w_dtr(pprt, oldval & ~scan_mask_o);

	/* will have a 1 for each bit set to gnd */
	bitmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;
	/* disable all matrix signals */
	w_dtr(pprt, oldval);

	/* now that all outputs are cleared, the only active input bits are
	 * directly connected to the ground
	 */

	/* 1 for each grounded input */
	gndmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;

	/* grounded inputs are signals 40-44 */
	phys_read |= (__u64)gndmask << 40;

	if (bitmask != gndmask) {
		/*
		 * since clearing the outputs changed some inputs, we know
		 * that some input signals are currently tied to some outputs.
		 * So we'll scan them.
		 */
		for (bit = 0; bit < 8; bit++) {
			bitval = BIT(bit);

			if (!(scan_mask_o & bitval))	/* skip unused bits */
				continue;

			w_dtr(pprt, oldval & ~bitval);	/* enable this output */
			bitmask = PNL_PINPUT(r_str(pprt)) & ~gndmask;
			phys_read |= (__u64)bitmask << (5 * bit);
		}
		w_dtr(pprt, oldval);	/* disable all outputs */
	}
	/*
	 * this is easy: use old bits when they are flapping,
	 * use new ones when stable
	 */
	phys_curr = (phys_prev & (phys_read ^ phys_read_prev)) |
		    (phys_read & ~(phys_read ^ phys_read_prev));
}

static inline int input_state_high(struct logical_input *input)
{
#if 0
	/* FIXME:
	 * this is an invalid test. It tries to catch
	 * transitions from single-key to multiple-key, but
	 * doesn't take into account the contacts polarity.
	 * The only solution to the problem is to parse keys
	 * from the most complex to the simplest combinations,
	 * and mark them as 'caught' once a combination
	 * matches, then unmatch it for all other ones.
	 */

	/* try to catch dangerous transitions cases :
	 * someone adds a bit, so this signal was a false
	 * positive resulting from a transition. We should
	 * invalidate the signal immediately and not call the
	 * release function.
	 * eg: 0 -(press A)-> A -(press B)-> AB : don't match A's release.
	 */
	if (((phys_prev & input->mask) == input->value) &&
	    ((phys_curr & input->mask) >  input->value)) {
		input->state = INPUT_ST_LOW; /* invalidate */
		return 1;
	}
#endif

	if ((phys_curr & input->mask) == input->value) {
		if ((input->type == INPUT_TYPE_STD) &&
		    (input->high_timer == 0)) {
			input->high_timer++;
			if (input->u.std.press_fct)
				input->u.std.press_fct(input->u.std.press_data);
		} else if (input->type == INPUT_TYPE_KBD) {
			/* will turn on the light */
			keypressed = 1;

			if (input->high_timer == 0) {
				char *press_str = input->u.kbd.press_str;

				if (press_str[0]) {
					int s = sizeof(input->u.kbd.press_str);

					keypad_send_key(press_str, s);
				}
			}

			if (input->u.kbd.repeat_str[0]) {
				char *repeat_str = input->u.kbd.repeat_str;

				if (input->high_timer >= KEYPAD_REP_START) {
					int s = sizeof(input->u.kbd.repeat_str);

					input->high_timer -= KEYPAD_REP_DELAY;
					keypad_send_key(repeat_str, s);
				}
				/* we will need to come back here soon */
				inputs_stable = 0;
			}

			if (input->high_timer < 255)
				input->high_timer++;
		}
		return 1;
	}

	/* else signal falling down. Let's fall through. */
	input->state = INPUT_ST_FALLING;
	input->fall_timer = 0;

	return 0;
}

static inline void input_state_falling(struct logical_input *input)
{
#if 0
	/* FIXME !!! same comment as in input_state_high */
	if (((phys_prev & input->mask) == input->value) &&
	    ((phys_curr & input->mask) >  input->value)) {
		input->state = INPUT_ST_LOW;	/* invalidate */
		return;
	}
#endif

	if ((phys_curr & input->mask) == input->value) {
		if (input->type == INPUT_TYPE_KBD) {
			/* will turn on the light */
			keypressed = 1;

			if (input->u.kbd.repeat_str[0]) {
				char *repeat_str = input->u.kbd.repeat_str;

				if (input->high_timer >= KEYPAD_REP_START) {
					int s = sizeof(input->u.kbd.repeat_str);

					input->high_timer -= KEYPAD_REP_DELAY;
					keypad_send_key(repeat_str, s);
				}
				/* we will need to come back here soon */
				inputs_stable = 0;
			}

			if (input->high_timer < 255)
				input->high_timer++;
		}
		input->state = INPUT_ST_HIGH;
	} else if (input->fall_timer >= input->fall_time) {
		/* call release event */
		if (input->type == INPUT_TYPE_STD) {
			void (*release_fct)(int) = input->u.std.release_fct;

			if (release_fct)
				release_fct(input->u.std.release_data);
		} else if (input->type == INPUT_TYPE_KBD) {
			char *release_str = input->u.kbd.release_str;

			if (release_str[0]) {
				int s = sizeof(input->u.kbd.release_str);

				keypad_send_key(release_str, s);
			}
		}

		input->state = INPUT_ST_LOW;
	} else {
		input->fall_timer++;
		inputs_stable = 0;
	}
}

static void panel_process_inputs(void)
{
	struct logical_input *input;

	keypressed = 0;
	inputs_stable = 1;
	list_for_each_entry(input, &logical_inputs, list) {
		switch (input->state) {
		case INPUT_ST_LOW:
			if ((phys_curr & input->mask) != input->value)
				break;
			/* if all needed ones were already set previously,
			 * this means that this logical signal has been
			 * activated by the releasing of another combined
			 * signal, so we don't want to match.
			 * eg: AB -(release B)-> A -(release A)-> 0 :
			 *     don't match A.
			 */
			if ((phys_prev & input->mask) == input->value)
				break;
			input->rise_timer = 0;
			input->state = INPUT_ST_RISING;
			fallthrough;
		case INPUT_ST_RISING:
			if ((phys_curr & input->mask) != input->value) {
				input->state = INPUT_ST_LOW;
				break;
			}
			if (input->rise_timer < input->rise_time) {
				inputs_stable = 0;
				input->rise_timer++;
				break;
			}
			input->high_timer = 0;
			input->state = INPUT_ST_HIGH;
			fallthrough;
		case INPUT_ST_HIGH:
			if (input_state_high(input))
				break;
			fallthrough;
		case INPUT_ST_FALLING:
			input_state_falling(input);
		}
	}
}

static void panel_scan_timer(struct timer_list *unused)
{
	if (keypad.enabled && keypad_initialized) {
		if (spin_trylock_irq(&pprt_lock)) {
			phys_scan_contacts();

			/* no need for the parport anymore */
			spin_unlock_irq(&pprt_lock);
		}

		if (!inputs_stable || phys_curr != phys_prev)
			panel_process_inputs();
	}

	if (keypressed && lcd.enabled && lcd.initialized)
		charlcd_poke(lcd.charlcd);

	mod_timer(&scan_timer, jiffies + INPUT_POLL_TIME);
}

static void init_scan_timer(void)
{
	if (scan_timer.function)
		return;		/* already started */

	timer_setup(&scan_timer, panel_scan_timer, 0);
	scan_timer.expires = jiffies + INPUT_POLL_TIME;
	add_timer(&scan_timer);
}

/* converts a name of the form "({BbAaPpSsEe}{01234567-})*" to a series of bits.
 * if <omask> or <imask> are non-null, they will be or'ed with the bits
 * corresponding to out and in bits respectively.
 * returns 1 if ok, 0 if error (in which case, nothing is written).
 */
static u8 input_name2mask(const char *name, __u64 *mask, __u64 *value,
			  u8 *imask, u8 *omask)
{
	const char sigtab[] = "EeSsPpAaBb";
	u8 im, om;
	__u64 m, v;

	om = 0;
	im = 0;
	m = 0ULL;
	v = 0ULL;
	while (*name) {
		int in, out, bit, neg;
		const char *idx;

		idx = strchr(sigtab, *name);
		if (!idx)
			return 0;	/* input name not found */

		in = idx - sigtab;
		neg = (in & 1);	/* odd (lower) names are negated */
		in >>= 1;
		im |= BIT(in);

		name++;
		if (*name >= '0' && *name <= '7') {
			out = *name - '0';
			om |= BIT(out);
		} else if (*name == '-') {
			out = 8;
		} else {
			return 0;	/* unknown bit name */
		}

		bit = (out * 5) + in;

		m |= 1ULL << bit;
		if (!neg)
			v |= 1ULL << bit;
		name++;
	}
	*mask = m;
	*value = v;
	if (imask)
		*imask |= im;
	if (omask)
		*omask |= om;
	return 1;
}

/* tries to bind a key to the signal name <name>. The key will send the
 * strings <press>, <repeat>, <release> for these respective events.
 * Returns the pointer to the new key if ok, NULL if the key could not be bound.
 */
static struct logical_input *panel_bind_key(const char *name, const char *press,
					    const char *repeat,
					    const char *release)
{
	struct logical_input *key;

	key = kzalloc(sizeof(*key), GFP_KERNEL);
	if (!key)
		return NULL;

	if (!input_name2mask(name, &key->mask, &key->value, &scan_mask_i,
			     &scan_mask_o)) {
		kfree(key);
		return NULL;
	}

	key->type = INPUT_TYPE_KBD;
	key->state = INPUT_ST_LOW;
	key->rise_time = 1;
	key->fall_time = 1;

	strncpy(key->u.kbd.press_str, press, sizeof(key->u.kbd.press_str));
	strncpy(key->u.kbd.repeat_str, repeat, sizeof(key->u.kbd.repeat_str));
	strncpy(key->u.kbd.release_str, release,
		sizeof(key->u.kbd.release_str));
	list_add(&key->list, &logical_inputs);
	return key;
}

#if 0
/* tries to bind a callback function to the signal name <name>. The function
 * <press_fct> will be called with the <press_data> arg when the signal is
 * activated, and so on for <release_fct>/<release_data>
 * Returns the pointer to the new signal if ok, NULL if the signal could not
 * be bound.
 */
static struct logical_input *panel_bind_callback(char *name,
						 void (*press_fct)(int),
						 int press_data,
						 void (*release_fct)(int),
						 int release_data)
{
	struct logical_input *callback;

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

	memset(callback, 0, sizeof(struct logical_input));
	if (!input_name2mask(name, &callback->mask, &callback->value,
			     &scan_mask_i, &scan_mask_o))
		return NULL;

	callback->type = INPUT_TYPE_STD;
	callback->state = INPUT_ST_LOW;
	callback->rise_time = 1;
	callback->fall_time = 1;
	callback->u.std.press_fct = press_fct;
	callback->u.std.press_data = press_data;
	callback->u.std.release_fct = release_fct;
	callback->u.std.release_data = release_data;
	list_add(&callback->list, &logical_inputs);
	return callback;
}
#endif

static void keypad_init(void)
{
	int keynum;

	init_waitqueue_head(&keypad_read_wait);
	keypad_buflen = 0;	/* flushes any eventual noisy keystroke */

	/* Let's create all known keys */

	for (keynum = 0; keypad_profile[keynum][0][0]; keynum++) {
		panel_bind_key(keypad_profile[keynum][0],
			       keypad_profile[keynum][1],
			       keypad_profile[keynum][2],
			       keypad_profile[keynum][3]);
	}

	init_scan_timer();
	keypad_initialized = 1;
}

/**************************************************/
/* device initialization                          */
/**************************************************/

static void panel_attach(struct parport *port)
{
	struct pardev_cb panel_cb;

	if (port->number != parport)
		return;

	if (pprt) {
		pr_err("%s: port->number=%d parport=%d, already registered!\n",
		       __func__, port->number, parport);
		return;
	}

	memset(&panel_cb, 0, sizeof(panel_cb));
	panel_cb.private = &pprt;
	/* panel_cb.flags = 0 should be PARPORT_DEV_EXCL? */

	pprt = parport_register_dev_model(port, "panel", &panel_cb, 0);
	if (!pprt) {
		pr_err("%s: port->number=%d parport=%d, parport_register_device() failed\n",
		       __func__, port->number, parport);
		return;
	}

	if (parport_claim(pprt)) {
		pr_err("could not claim access to parport%d. Aborting.\n",
		       parport);
		goto err_unreg_device;
	}

	/* must init LCD first, just in case an IRQ from the keypad is
	 * generated at keypad init
	 */
	if (lcd.enabled) {
		lcd_init();
		if (!lcd.charlcd || charlcd_register(lcd.charlcd))
			goto err_unreg_device;
	}

	if (keypad.enabled) {
		keypad_init();
		if (misc_register(&keypad_dev))
			goto err_lcd_unreg;
	}
	return;

err_lcd_unreg:
	if (scan_timer.function)
		del_timer_sync(&scan_timer);
	if (lcd.enabled)
		charlcd_unregister(lcd.charlcd);
err_unreg_device:
	charlcd_free(lcd.charlcd);
	lcd.charlcd = NULL;
	parport_unregister_device(pprt);
	pprt = NULL;
}

static void panel_detach(struct parport *port)
{
	if (port->number != parport)
		return;

	if (!pprt) {
		pr_err("%s: port->number=%d parport=%d, nothing to unregister.\n",
		       __func__, port->number, parport);
		return;
	}
	if (scan_timer.function)
		del_timer_sync(&scan_timer);

	if (keypad.enabled) {
		misc_deregister(&keypad_dev);
		keypad_initialized = 0;
	}

	if (lcd.enabled) {
		charlcd_unregister(lcd.charlcd);
		lcd.initialized = false;
		charlcd_free(lcd.charlcd);
		lcd.charlcd = NULL;
	}

	/* TODO: free all input signals */
	parport_release(pprt);
	parport_unregister_device(pprt);
	pprt = NULL;
}

static struct parport_driver panel_driver = {
	.name = "panel",
	.match_port = panel_attach,
	.detach = panel_detach,
	.devmodel = true,
};

/* init function */
static int __init panel_init_module(void)
{
	int selected_keypad_type = NOT_SET, err;

	/* take care of an eventual profile */
	switch (profile) {
	case PANEL_PROFILE_CUSTOM:
		/* custom profile */
		selected_keypad_type = DEFAULT_KEYPAD_TYPE;
		selected_lcd_type = DEFAULT_LCD_TYPE;
		break;
	case PANEL_PROFILE_OLD:
		/* 8 bits, 2*16, old keypad */
		selected_keypad_type = KEYPAD_TYPE_OLD;
		selected_lcd_type = LCD_TYPE_OLD;

		/* TODO: This two are a little hacky, sort it out later */
		if (lcd_width == NOT_SET)
			lcd_width = 16;
		if (lcd_hwidth == NOT_SET)
			lcd_hwidth = 16;
		break;
	case PANEL_PROFILE_NEW:
		/* serial, 2*16, new keypad */
		selected_keypad_type = KEYPAD_TYPE_NEW;
		selected_lcd_type = LCD_TYPE_KS0074;
		break;
	case PANEL_PROFILE_HANTRONIX:
		/* 8 bits, 2*16 hantronix-like, no keypad */
		selected_keypad_type = KEYPAD_TYPE_NONE;
		selected_lcd_type = LCD_TYPE_HANTRONIX;
		break;
	case PANEL_PROFILE_NEXCOM:
		/* generic 8 bits, 2*16, nexcom keypad, eg. Nexcom. */
		selected_keypad_type = KEYPAD_TYPE_NEXCOM;
		selected_lcd_type = LCD_TYPE_NEXCOM;
		break;
	case PANEL_PROFILE_LARGE:
		/* 8 bits, 2*40, old keypad */
		selected_keypad_type = KEYPAD_TYPE_OLD;
		selected_lcd_type = LCD_TYPE_OLD;
		break;
	}

	/*
	 * Overwrite selection with module param values (both keypad and lcd),
	 * where the deprecated params have lower prio.
	 */
	if (keypad_enabled != NOT_SET)
		selected_keypad_type = keypad_enabled;
	if (keypad_type != NOT_SET)
		selected_keypad_type = keypad_type;

	keypad.enabled = (selected_keypad_type > 0);

	if (lcd_enabled != NOT_SET)
		selected_lcd_type = lcd_enabled;
	if (lcd_type != NOT_SET)
		selected_lcd_type = lcd_type;

	lcd.enabled = (selected_lcd_type > 0);

	if (lcd.enabled) {
		/*
		 * Init lcd struct with load-time values to preserve exact
		 * current functionality (at least for now).
		 */
		lcd.charset = lcd_charset;
		lcd.proto = lcd_proto;
		lcd.pins.e = lcd_e_pin;
		lcd.pins.rs = lcd_rs_pin;
		lcd.pins.rw = lcd_rw_pin;
		lcd.pins.cl = lcd_cl_pin;
		lcd.pins.da = lcd_da_pin;
		lcd.pins.bl = lcd_bl_pin;
	}

	switch (selected_keypad_type) {
	case KEYPAD_TYPE_OLD:
		keypad_profile = old_keypad_profile;
		break;
	case KEYPAD_TYPE_NEW:
		keypad_profile = new_keypad_profile;
		break;
	case KEYPAD_TYPE_NEXCOM:
		keypad_profile = nexcom_keypad_profile;
		break;
	default:
		keypad_profile = NULL;
		break;
	}

	if (!lcd.enabled && !keypad.enabled) {
		/* no device enabled, let's exit */
		pr_err("panel driver disabled.\n");
		return -ENODEV;
	}

	err = parport_register_driver(&panel_driver);
	if (err) {
		pr_err("could not register with parport. Aborting.\n");
		return err;
	}

	if (pprt)
		pr_info("panel driver registered on parport%d (io=0x%lx).\n",
			parport, pprt->port->base);
	else
		pr_info("panel driver not yet registered\n");
	return 0;
}

static void __exit panel_cleanup_module(void)
{
	parport_unregister_driver(&panel_driver);
}

module_init(panel_init_module);
module_exit(panel_cleanup_module);
MODULE_AUTHOR("Willy Tarreau");
MODULE_LICENSE("GPL");

/*
 * Local variables:
 *  c-indent-level: 4
 *  tab-width: 8
 * End:
 */