aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/depca.c
blob: 5113eef755b98cbc5104d9e4a4aff493b6a5be67 (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
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
/*  depca.c: A DIGITAL DEPCA & EtherWORKS ethernet driver for linux.

    Written 1994, 1995 by David C. Davies.


                      Copyright 1994 David C. Davies
		                   and
			 United States Government
	 (as represented by the Director, National Security Agency).

               Copyright 1995  Digital Equipment Corporation.


    This software may be used and distributed according to the terms of
    the GNU General Public License, incorporated herein by reference.

    This driver is written for the Digital Equipment Corporation series
    of DEPCA and EtherWORKS ethernet cards:

        DEPCA       (the original)
    	DE100
    	DE101
	DE200 Turbo
	DE201 Turbo
	DE202 Turbo (TP BNC)
	DE210
	DE422       (EISA)

    The  driver has been tested on DE100, DE200 and DE202 cards  in  a
    relatively busy network. The DE422 has been tested a little.

    This  driver will NOT work   for the DE203,  DE204  and DE205 series  of
    cards,  since they have  a  new custom ASIC in   place of the AMD  LANCE
    chip.  See the 'ewrk3.c'   driver in the  Linux  source tree for running
    those cards.

    I have benchmarked the driver with a  DE100 at 595kB/s to (542kB/s from)
    a DECstation 5000/200.

    The author may be reached at davies@maniac.ultranet.com

    =========================================================================

    The  driver was originally based  on   the 'lance.c' driver from  Donald
    Becker   which  is included with  the  standard  driver distribution for
    linux.  V0.4  is  a complete  re-write  with only  the kernel  interface
    remaining from the original code.

    1) Lance.c code in /linux/drivers/net/
    2) "Ethernet/IEEE 802.3 Family. 1992 World Network Data Book/Handbook",
       AMD, 1992 [(800) 222-9323].
    3) "Am79C90 CMOS Local Area Network Controller for Ethernet (C-LANCE)",
       AMD, Pub. #17881, May 1993.
    4) "Am79C960 PCnet-ISA(tm), Single-Chip Ethernet Controller for ISA",
       AMD, Pub. #16907, May 1992
    5) "DEC EtherWORKS LC Ethernet Controller Owners Manual",
       Digital Equipment corporation, 1990, Pub. #EK-DE100-OM.003
    6) "DEC EtherWORKS Turbo Ethernet Controller Owners Manual",
       Digital Equipment corporation, 1990, Pub. #EK-DE200-OM.003
    7) "DEPCA Hardware Reference Manual", Pub. #EK-DEPCA-PR
       Digital Equipment Corporation, 1989
    8) "DEC EtherWORKS Turbo_(TP BNC) Ethernet Controller Owners Manual",
       Digital Equipment corporation, 1991, Pub. #EK-DE202-OM.001


    Peter Bauer's depca.c (V0.5) was referred to when debugging V0.1 of this
    driver.

    The original DEPCA  card requires that the  ethernet ROM address counter
    be enabled to count and has an 8 bit NICSR.  The ROM counter enabling is
    only  done when a  0x08 is read as the  first address octet (to minimise
    the chances  of writing over some  other hardware's  I/O register).  The
    NICSR accesses   have been changed  to  byte accesses  for all the cards
    supported by this driver, since there is only one  useful bit in the MSB
    (remote boot timeout) and it  is not used.  Also, there  is a maximum of
    only 48kB network  RAM for this  card.  My thanks  to Torbjorn Lindh for
    help debugging all this (and holding my feet to  the fire until I got it
    right).

    The DE200  series  boards have  on-board 64kB  RAM for  use  as a shared
    memory network  buffer. Only the DE100  cards make use  of a  2kB buffer
    mode which has not  been implemented in  this driver (only the 32kB  and
    64kB modes are supported [16kB/48kB for the original DEPCA]).

    At the most only 2 DEPCA cards can  be supported on  the ISA bus because
    there is only provision  for two I/O base addresses  on each card (0x300
    and 0x200). The I/O address is detected by searching for a byte sequence
    in the Ethernet station address PROM at the expected I/O address for the
    Ethernet  PROM.   The shared memory  base   address  is 'autoprobed'  by
    looking  for the self  test PROM  and detecting the  card name.   When a
    second  DEPCA is  detected,  information  is   placed in the   base_addr
    variable of the  next device structure (which  is created if necessary),
    thus  enabling ethif_probe  initialization  for the device.  More than 2
    EISA cards can  be  supported, but  care will  be  needed assigning  the
    shared memory to ensure that each slot has the  correct IRQ, I/O address
    and shared memory address assigned.

    ************************************************************************

    NOTE: If you are using two  ISA DEPCAs, it is  important that you assign
    the base memory addresses correctly.   The  driver autoprobes I/O  0x300
    then 0x200.  The  base memory address for  the first device must be less
    than that of the second so that the auto probe will correctly assign the
    I/O and memory addresses on the same card.  I can't think of a way to do
    this unambiguously at the moment, since there is nothing on the cards to
    tie I/O and memory information together.

    I am unable  to  test  2 cards   together for now,    so this  code   is
    unchecked. All reports, good or bad, are welcome.

    ************************************************************************

    The board IRQ   setting must be  at an  unused IRQ which  is auto-probed
    using Donald Becker's autoprobe routines. DEPCA and DE100 board IRQs are
    {2,3,4,5,7}, whereas the  DE200 is at {5,9,10,11,15}.  Note that IRQ2 is
    really IRQ9 in machines with 16 IRQ lines.

    No 16MB memory  limitation should exist with this  driver as DMA is  not
    used and the common memory area is in low memory on the network card (my
    current system has 20MB and I've not had problems yet).

    The ability to load this driver as a loadable module has been added. To
    utilise this ability, you have to do <8 things:

    0) have a copy of the loadable modules code installed on your system.
    1) copy depca.c from the  /linux/drivers/net directory to your favourite
    temporary directory.
    2) if you wish, edit the  source code near  line 1530 to reflect the I/O
    address and IRQ you're using (see also 5).
    3) compile  depca.c, but include -DMODULE in  the command line to ensure
    that the correct bits are compiled (see end of source code).
    4) if you are wanting to add a new  card, goto 5. Otherwise, recompile a
    kernel with the depca configuration turned off and reboot.
    5) insmod depca.o [irq=7] [io=0x200] [mem=0xd0000] [adapter_name=DE100]
       [Alan Cox: Changed the code to allow command line irq/io assignments]
       [Dave Davies: Changed the code to allow command line mem/name
                                                                assignments]
    6) run the net startup bits for your eth?? interface manually
    (usually /etc/rc.inet[12] at boot time).
    7) enjoy!

    Note that autoprobing is not allowed in loadable modules - the system is
    already up and running and you're messing with interrupts.

    To unload a module, turn off the associated interface
    'ifconfig eth?? down' then 'rmmod depca'.

    To assign a base memory address for the shared memory  when running as a
    loadable module, see 5 above.  To include the adapter  name (if you have
    no PROM  but know the card name)  also see 5  above. Note that this last
    option  will not work  with kernel  built-in  depca's.

    The shared memory assignment for a loadable module  makes sense to avoid
    the 'memory autoprobe' picking the wrong shared memory  (for the case of
    2 depca's in a PC).

    ************************************************************************
    Support for MCA EtherWORKS cards added 11-3-98.
    Verified to work with up to 2 DE212 cards in a system (although not
      fully stress-tested).

    Currently known bugs/limitations:

    Note:  with the MCA stuff as a module, it trusts the MCA configuration,
           not the command line for IRQ and memory address.  You can
           specify them if you want, but it will throw your values out.
           You still have to pass the IO address it was configured as
           though.

    ************************************************************************
    TO DO:
    ------


    Revision History
    ----------------

    Version   Date        Description

      0.1     25-jan-94   Initial writing.
      0.2     27-jan-94   Added LANCE TX hardware buffer chaining.
      0.3      1-feb-94   Added multiple DEPCA support.
      0.31     4-feb-94   Added DE202 recognition.
      0.32    19-feb-94   Tidy up. Improve multi-DEPCA support.
      0.33    25-feb-94   Fix DEPCA ethernet ROM counter enable.
                          Add jabber packet fix from murf@perftech.com
			  and becker@super.org
      0.34     7-mar-94   Fix DEPCA max network memory RAM & NICSR access.
      0.35     8-mar-94   Added DE201 recognition. Tidied up.
      0.351   30-apr-94   Added EISA support. Added DE422 recognition.
      0.36    16-may-94   DE422 fix released.
      0.37    22-jul-94   Added MODULE support
      0.38    15-aug-94   Added DBR ROM switch in depca_close().
                          Multi DEPCA bug fix.
      0.38axp 15-sep-94   Special version for Alpha AXP Linux V1.0.
      0.381   12-dec-94   Added DE101 recognition, fix multicast bug.
      0.382    9-feb-95   Fix recognition bug reported by <bkm@star.rl.ac.uk>.
      0.383   22-feb-95   Fix for conflict with VESA SCSI reported by
                          <stromain@alf.dec.com>
      0.384   17-mar-95   Fix a ring full bug reported by <bkm@star.rl.ac.uk>
      0.385    3-apr-95   Fix a recognition bug reported by
                                                <ryan.niemi@lastfrontier.com>
      0.386   21-apr-95   Fix the last fix...sorry, must be galloping senility
      0.40    25-May-95   Rewrite for portability & updated.
                          ALPHA support from <jestabro@amt.tay1.dec.com>
      0.41    26-Jun-95   Added verify_area() calls in depca_ioctl() from
                          suggestion by <heiko@colossus.escape.de>
      0.42    27-Dec-95   Add 'mem' shared memory assignment for loadable
                          modules.
                          Add 'adapter_name' for loadable modules when no PROM.
			  Both above from a suggestion by
			  <pchen@woodruffs121.residence.gatech.edu>.
			  Add new multicasting code.
      0.421   22-Apr-96	  Fix alloc_device() bug <jari@markkus2.fimr.fi>
      0.422   29-Apr-96	  Fix depca_hw_init() bug <jari@markkus2.fimr.fi>
      0.423    7-Jun-96   Fix module load bug <kmg@barco.be>
      0.43    16-Aug-96   Update alloc_device() to conform to de4x5.c
      0.44     1-Sep-97   Fix *_probe() to test check_region() first - bug
                           reported by <mmogilvi@elbert.uccs.edu>
      0.45     3-Nov-98   Added support for MCA EtherWORKS (DE210/DE212) cards
                           by <tymm@computer.org>
      0.451    5-Nov-98   Fixed mca stuff cuz I'm a dummy. <tymm@computer.org>
      0.5     14-Nov-98   Re-spin for 2.1.x kernels.
      0.51    27-Jun-99   Correct received packet length for CRC from
                           report by <worm@dkik.dk>
      0.52    16-Oct-00   Fixes for 2.3 io memory accesses
                          Fix show-stopper (ints left masked) in depca_interrupt
			   by <peterd@pnd-pc.demon.co.uk>
      0.53    12-Jan-01	  Release resources on failure, bss tidbits
      			   by acme@conectiva.com.br
      0.54    08-Nov-01	  use library crc32 functions
      			   by Matt_Domsch@dell.com
      0.55    01-Mar-03   Use EISA/sysfs framework <maz@wild-wind.fr.eu.org>

    =========================================================================
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/crc32.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/time.h>
#include <linux/types.h>
#include <linux/unistd.h>
#include <linux/ctype.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/dma.h>

#ifdef CONFIG_MCA
#include <linux/mca.h>
#endif

#ifdef CONFIG_EISA
#include <linux/eisa.h>
#endif

#include "depca.h"

static char version[] __initdata = "depca.c:v0.53 2001/1/12 davies@maniac.ultranet.com\n";

#ifdef DEPCA_DEBUG
static int depca_debug = DEPCA_DEBUG;
#else
static int depca_debug = 1;
#endif

#define DEPCA_NDA 0xffe0	/* No Device Address */

#define TX_TIMEOUT (1*HZ)

/*
** Ethernet PROM defines
*/
#define PROBE_LENGTH    32
#define ETH_PROM_SIG    0xAA5500FFUL

/*
** Set the number of Tx and Rx buffers. Ensure that the memory requested
** here is <= to the amount of shared memory set up by the board switches.
** The number of descriptors MUST BE A POWER OF 2.
**
** total_memory = NUM_RX_DESC*(8+RX_BUFF_SZ) + NUM_TX_DESC*(8+TX_BUFF_SZ)
*/
#define NUM_RX_DESC     8	/* Number of RX descriptors */
#define NUM_TX_DESC     8	/* Number of TX descriptors */
#define RX_BUFF_SZ	1536	/* Buffer size for each Rx buffer */
#define TX_BUFF_SZ	1536	/* Buffer size for each Tx buffer */

/*
** EISA bus defines
*/
#define DEPCA_EISA_IO_PORTS 0x0c00	/* I/O port base address, slot 0 */

/*
** ISA Bus defines
*/
#define DEPCA_RAM_BASE_ADDRESSES {0xc0000,0xd0000,0xe0000,0x00000}
#define DEPCA_TOTAL_SIZE 0x10

static struct {
	u_long iobase;
	struct platform_device *device;
} depca_io_ports[] = {
	{ 0x300, NULL },
	{ 0x200, NULL },
	{ 0    , NULL },
};

/*
** Name <-> Adapter mapping
*/
#define DEPCA_SIGNATURE {"DEPCA",\
			 "DE100","DE101",\
                         "DE200","DE201","DE202",\
			 "DE210","DE212",\
                         "DE422",\
                         ""}

static char* __initdata depca_signature[] = DEPCA_SIGNATURE;

enum depca_type {
	DEPCA, de100, de101, de200, de201, de202, de210, de212, de422, unknown
};

static char depca_string[] = "depca";

static int depca_device_remove (struct device *device);

#ifdef CONFIG_EISA
static struct eisa_device_id depca_eisa_ids[] = {
	{ "DEC4220", de422 },
	{ "" }
};
MODULE_DEVICE_TABLE(eisa, depca_eisa_ids);

static int depca_eisa_probe  (struct device *device);

static struct eisa_driver depca_eisa_driver = {
	.id_table = depca_eisa_ids,
	.driver   = {
		.name    = depca_string,
		.probe   = depca_eisa_probe,
		.remove  = __devexit_p (depca_device_remove)
	}
};
#endif

#ifdef CONFIG_MCA
/*
** Adapter ID for the MCA EtherWORKS DE210/212 adapter
*/
#define DE210_ID 0x628d
#define DE212_ID 0x6def

static short depca_mca_adapter_ids[] = {
	DE210_ID,
	DE212_ID,
	0x0000
};

static char *depca_mca_adapter_name[] = {
	"DEC EtherWORKS MC Adapter (DE210)",
	"DEC EtherWORKS MC Adapter (DE212)",
	NULL
};

static enum depca_type depca_mca_adapter_type[] = {
	de210,
	de212,
	0
};

static int depca_mca_probe (struct device *);

static struct mca_driver depca_mca_driver = {
	.id_table = depca_mca_adapter_ids,
	.driver   = {
		.name   = depca_string,
		.bus    = &mca_bus_type,
		.probe  = depca_mca_probe,
		.remove = __devexit_p(depca_device_remove),
	},
};
#endif

static int depca_isa_probe (struct platform_device *);

static int __devexit depca_isa_remove(struct platform_device *pdev)
{
	return depca_device_remove(&pdev->dev);
}

static struct platform_driver depca_isa_driver = {
	.probe  = depca_isa_probe,
	.remove = __devexit_p(depca_isa_remove),
	.driver	= {
		.name   = depca_string,
	},
};

/*
** Miscellaneous info...
*/
#define DEPCA_STRLEN 16

/*
** Memory Alignment. Each descriptor is 4 longwords long. To force a
** particular alignment on the TX descriptor, adjust DESC_SKIP_LEN and
** DESC_ALIGN. DEPCA_ALIGN aligns the start address of the private memory area
** and hence the RX descriptor ring's first entry.
*/
#define DEPCA_ALIGN4      ((u_long)4 - 1)	/* 1 longword align */
#define DEPCA_ALIGN8      ((u_long)8 - 1)	/* 2 longword (quadword) align */
#define DEPCA_ALIGN         DEPCA_ALIGN8	/* Keep the LANCE happy... */

/*
** The DEPCA Rx and Tx ring descriptors.
*/
struct depca_rx_desc {
	volatile s32 base;
	s16 buf_length;		/* This length is negative 2's complement! */
	s16 msg_length;		/* This length is "normal". */
};

struct depca_tx_desc {
	volatile s32 base;
	s16 length;		/* This length is negative 2's complement! */
	s16 misc;		/* Errors and TDR info */
};

#define LA_MASK 0x0000ffff	/* LANCE address mask for mapping network RAM
				   to LANCE memory address space */

/*
** The Lance initialization block, described in databook, in common memory.
*/
struct depca_init {
	u16 mode;		/* Mode register */
	u8 phys_addr[ETH_ALEN];	/* Physical ethernet address */
	u8 mcast_table[8];	/* Multicast Hash Table. */
	u32 rx_ring;		/* Rx ring base pointer & ring length */
	u32 tx_ring;		/* Tx ring base pointer & ring length */
};

#define DEPCA_PKT_STAT_SZ 16
#define DEPCA_PKT_BIN_SZ  128	/* Should be >=100 unless you
				   increase DEPCA_PKT_STAT_SZ */
struct depca_private {
	char adapter_name[DEPCA_STRLEN];	/* /proc/ioports string                  */
	enum depca_type adapter;		/* Adapter type */
	enum {
                DEPCA_BUS_MCA = 1,
                DEPCA_BUS_ISA,
                DEPCA_BUS_EISA,
        } depca_bus;	        /* type of bus */
	struct depca_init init_block;	/* Shadow Initialization block            */
/* CPU address space fields */
	struct depca_rx_desc __iomem *rx_ring;	/* Pointer to start of RX descriptor ring */
	struct depca_tx_desc __iomem *tx_ring;	/* Pointer to start of TX descriptor ring */
	void __iomem *rx_buff[NUM_RX_DESC];	/* CPU virt address of sh'd memory buffs  */
	void __iomem *tx_buff[NUM_TX_DESC];	/* CPU virt address of sh'd memory buffs  */
	void __iomem *sh_mem;	/* CPU mapped virt address of device RAM  */
	u_long mem_start;	/* Bus address of device RAM (before remap) */
	u_long mem_len;		/* device memory size */
/* Device address space fields */
	u_long device_ram_start;	/* Start of RAM in device addr space      */
/* Offsets used in both address spaces */
	u_long rx_ring_offset;	/* Offset from start of RAM to rx_ring    */
	u_long tx_ring_offset;	/* Offset from start of RAM to tx_ring    */
	u_long buffs_offset;	/* LANCE Rx and Tx buffers start address. */
/* Kernel-only (not device) fields */
	int rx_new, tx_new;	/* The next free ring entry               */
	int rx_old, tx_old;	/* The ring entries to be free()ed.       */
	struct net_device_stats stats;
	spinlock_t lock;
	struct {		/* Private stats counters                 */
		u32 bins[DEPCA_PKT_STAT_SZ];
		u32 unicast;
		u32 multicast;
		u32 broadcast;
		u32 excessive_collisions;
		u32 tx_underruns;
		u32 excessive_underruns;
	} pktStats;
	int txRingMask;		/* TX ring mask                           */
	int rxRingMask;		/* RX ring mask                           */
	s32 rx_rlen;		/* log2(rxRingMask+1) for the descriptors */
	s32 tx_rlen;		/* log2(txRingMask+1) for the descriptors */
};

/*
** The transmit ring full condition is described by the tx_old and tx_new
** pointers by:
**    tx_old            = tx_new    Empty ring
**    tx_old            = tx_new+1  Full ring
**    tx_old+txRingMask = tx_new    Full ring  (wrapped condition)
*/
#define TX_BUFFS_AVAIL ((lp->tx_old<=lp->tx_new)?\
			 lp->tx_old+lp->txRingMask-lp->tx_new:\
                         lp->tx_old               -lp->tx_new-1)

/*
** Public Functions
*/
static int depca_open(struct net_device *dev);
static int depca_start_xmit(struct sk_buff *skb, struct net_device *dev);
static irqreturn_t depca_interrupt(int irq, void *dev_id);
static int depca_close(struct net_device *dev);
static int depca_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
static void depca_tx_timeout(struct net_device *dev);
static struct net_device_stats *depca_get_stats(struct net_device *dev);
static void set_multicast_list(struct net_device *dev);

/*
** Private functions
*/
static void depca_init_ring(struct net_device *dev);
static int depca_rx(struct net_device *dev);
static int depca_tx(struct net_device *dev);

static void LoadCSRs(struct net_device *dev);
static int InitRestartDepca(struct net_device *dev);
static int DepcaSignature(char *name, u_long paddr);
static int DevicePresent(u_long ioaddr);
static int get_hw_addr(struct net_device *dev);
static void SetMulticastFilter(struct net_device *dev);
static int load_packet(struct net_device *dev, struct sk_buff *skb);
static void depca_dbg_open(struct net_device *dev);

static u_char de1xx_irq[] __initdata = { 2, 3, 4, 5, 7, 9, 0 };
static u_char de2xx_irq[] __initdata = { 5, 9, 10, 11, 15, 0 };
static u_char de422_irq[] __initdata = { 5, 9, 10, 11, 0 };
static u_char *depca_irq;

static int irq;
static int io;
static char *adapter_name;
static int mem;			/* For loadable module assignment
				   use insmod mem=0x????? .... */
module_param (irq, int, 0);
module_param (io, int, 0);
module_param (adapter_name, charp, 0);
module_param (mem, int, 0);
MODULE_PARM_DESC(irq, "DEPCA IRQ number");
MODULE_PARM_DESC(io, "DEPCA I/O base address");
MODULE_PARM_DESC(adapter_name, "DEPCA adapter name");
MODULE_PARM_DESC(mem, "DEPCA shared memory address");
MODULE_LICENSE("GPL");

/*
** Miscellaneous defines...
*/
#define STOP_DEPCA \
    outw(CSR0, DEPCA_ADDR);\
    outw(STOP, DEPCA_DATA)

static int __init depca_hw_init (struct net_device *dev, struct device *device)
{
	struct depca_private *lp;
	int i, j, offset, netRAM, mem_len, status = 0;
	s16 nicsr;
	u_long ioaddr;
	u_long mem_start;

	/*
	 * We are now supposed to enter this function with the
	 * following fields filled with proper values :
	 *
	 * dev->base_addr
	 * lp->mem_start
	 * lp->depca_bus
	 * lp->adapter
	 *
	 * dev->irq can be set if known from device configuration (on
	 * MCA or EISA) or module option. Otherwise, it will be auto
	 * detected.
	 */

	ioaddr = dev->base_addr;

	STOP_DEPCA;

	nicsr = inb(DEPCA_NICSR);
	nicsr = ((nicsr & ~SHE & ~RBE & ~IEN) | IM);
	outb(nicsr, DEPCA_NICSR);

	if (inw(DEPCA_DATA) != STOP) {
		return -ENXIO;
	}

	lp = (struct depca_private *) dev->priv;
	mem_start = lp->mem_start;

	if (!mem_start || lp->adapter < DEPCA || lp->adapter >=unknown)
		return -ENXIO;

	printk ("%s: %s at 0x%04lx",
	        device->bus_id, depca_signature[lp->adapter], ioaddr);

	switch (lp->depca_bus) {
#ifdef CONFIG_MCA
	case DEPCA_BUS_MCA:
		printk(" (MCA slot %d)", to_mca_device(device)->slot + 1);
		break;
#endif

#ifdef CONFIG_EISA
	case DEPCA_BUS_EISA:
		printk(" (EISA slot %d)", to_eisa_device(device)->slot);
		break;
#endif

	case DEPCA_BUS_ISA:
		break;

	default:
		printk("Unknown DEPCA bus %d\n", lp->depca_bus);
		return -ENXIO;
	}

	printk(", h/w address ");
	status = get_hw_addr(dev);
	if (status != 0) {
		printk("      which has an Ethernet PROM CRC error.\n");
		return -ENXIO;
	}
	for (i = 0; i < ETH_ALEN - 1; i++) {	/* get the ethernet address */
		printk("%2.2x:", dev->dev_addr[i]);
	}
	printk("%2.2x", dev->dev_addr[i]);

	/* Set up the maximum amount of network RAM(kB) */
	netRAM = ((lp->adapter != DEPCA) ? 64 : 48);
	if ((nicsr & _128KB) && (lp->adapter == de422))
		netRAM = 128;

	/* Shared Memory Base Address */
	if (nicsr & BUF) {
		nicsr &= ~BS;	/* DEPCA RAM in top 32k */
		netRAM -= 32;

		/* Only EISA/ISA needs start address to be re-computed */
		if (lp->depca_bus != DEPCA_BUS_MCA)
			mem_start += 0x8000;
	}

	if ((mem_len = (NUM_RX_DESC * (sizeof(struct depca_rx_desc) + RX_BUFF_SZ) + NUM_TX_DESC * (sizeof(struct depca_tx_desc) + TX_BUFF_SZ) + sizeof(struct depca_init)))
	    > (netRAM << 10)) {
		printk(",\n       requests %dkB RAM: only %dkB is available!\n", (mem_len >> 10), netRAM);
		return -ENXIO;
	}

	printk(",\n      has %dkB RAM at 0x%.5lx", netRAM, mem_start);

	/* Enable the shadow RAM. */
	if (lp->adapter != DEPCA) {
		nicsr |= SHE;
		outb(nicsr, DEPCA_NICSR);
	}

	spin_lock_init(&lp->lock);
	sprintf(lp->adapter_name, "%s (%s)",
		depca_signature[lp->adapter], device->bus_id);
	status = -EBUSY;

	/* Initialisation Block */
	if (!request_mem_region (mem_start, mem_len, lp->adapter_name)) {
		printk(KERN_ERR "depca: cannot request ISA memory, aborting\n");
		goto out_priv;
	}

	status = -EIO;
	lp->sh_mem = ioremap(mem_start, mem_len);
	if (lp->sh_mem == NULL) {
		printk(KERN_ERR "depca: cannot remap ISA memory, aborting\n");
		goto out1;
	}

	lp->mem_start = mem_start;
	lp->mem_len   = mem_len;
	lp->device_ram_start = mem_start & LA_MASK;

	offset = 0;
	offset += sizeof(struct depca_init);

	/* Tx & Rx descriptors (aligned to a quadword boundary) */
	offset = (offset + DEPCA_ALIGN) & ~DEPCA_ALIGN;
	lp->rx_ring = (struct depca_rx_desc __iomem *) (lp->sh_mem + offset);
	lp->rx_ring_offset = offset;

	offset += (sizeof(struct depca_rx_desc) * NUM_RX_DESC);
	lp->tx_ring = (struct depca_tx_desc __iomem *) (lp->sh_mem + offset);
	lp->tx_ring_offset = offset;

	offset += (sizeof(struct depca_tx_desc) * NUM_TX_DESC);

	lp->buffs_offset = offset;

	/* Finish initialising the ring information. */
	lp->rxRingMask = NUM_RX_DESC - 1;
	lp->txRingMask = NUM_TX_DESC - 1;

	/* Calculate Tx/Rx RLEN size for the descriptors. */
	for (i = 0, j = lp->rxRingMask; j > 0; i++) {
		j >>= 1;
	}
	lp->rx_rlen = (s32) (i << 29);
	for (i = 0, j = lp->txRingMask; j > 0; i++) {
		j >>= 1;
	}
	lp->tx_rlen = (s32) (i << 29);

	/* Load the initialisation block */
	depca_init_ring(dev);

	/* Initialise the control and status registers */
	LoadCSRs(dev);

	/* Enable DEPCA board interrupts for autoprobing */
	nicsr = ((nicsr & ~IM) | IEN);
	outb(nicsr, DEPCA_NICSR);

	/* To auto-IRQ we enable the initialization-done and DMA err,
	   interrupts. For now we will always get a DMA error. */
	if (dev->irq < 2) {
		unsigned char irqnum;
		unsigned long irq_mask, delay;

		irq_mask = probe_irq_on();

		/* Assign the correct irq list */
		switch (lp->adapter) {
		case DEPCA:
		case de100:
		case de101:
			depca_irq = de1xx_irq;
			break;
		case de200:
		case de201:
		case de202:
		case de210:
		case de212:
			depca_irq = de2xx_irq;
			break;
		case de422:
			depca_irq = de422_irq;
			break;

		default:
			break;	/* Not reached */
		}

		/* Trigger an initialization just for the interrupt. */
		outw(INEA | INIT, DEPCA_DATA);

		delay = jiffies + HZ/50;
		while (time_before(jiffies, delay))
			yield();

		irqnum = probe_irq_off(irq_mask);

		status = -ENXIO;
		if (!irqnum) {
			printk(" and failed to detect IRQ line.\n");
			goto out2;
		} else {
			for (dev->irq = 0, i = 0; (depca_irq[i]) && (!dev->irq); i++)
				if (irqnum == depca_irq[i]) {
					dev->irq = irqnum;
					printk(" and uses IRQ%d.\n", dev->irq);
				}

			if (!dev->irq) {
				printk(" but incorrect IRQ line detected.\n");
				goto out2;
			}
		}
	} else {
		printk(" and assigned IRQ%d.\n", dev->irq);
	}

	if (depca_debug > 1) {
		printk(version);
	}

	/* The DEPCA-specific entries in the device structure. */
	dev->open = &depca_open;
	dev->hard_start_xmit = &depca_start_xmit;
	dev->stop = &depca_close;
	dev->get_stats = &depca_get_stats;
	dev->set_multicast_list = &set_multicast_list;
	dev->do_ioctl = &depca_ioctl;
	dev->tx_timeout = depca_tx_timeout;
	dev->watchdog_timeo = TX_TIMEOUT;

	dev->mem_start = 0;

	device->driver_data = dev;
	SET_NETDEV_DEV (dev, device);

	status = register_netdev(dev);
	if (status == 0)
		return 0;
out2:
	iounmap(lp->sh_mem);
out1:
	release_mem_region (mem_start, mem_len);
out_priv:
	return status;
}


static int depca_open(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;
	s16 nicsr;
	int status = 0;

	STOP_DEPCA;
	nicsr = inb(DEPCA_NICSR);

	/* Make sure the shadow RAM is enabled */
	if (lp->adapter != DEPCA) {
		nicsr |= SHE;
		outb(nicsr, DEPCA_NICSR);
	}

	/* Re-initialize the DEPCA... */
	depca_init_ring(dev);
	LoadCSRs(dev);

	depca_dbg_open(dev);

	if (request_irq(dev->irq, &depca_interrupt, 0, lp->adapter_name, dev)) {
		printk("depca_open(): Requested IRQ%d is busy\n", dev->irq);
		status = -EAGAIN;
	} else {

		/* Enable DEPCA board interrupts and turn off LED */
		nicsr = ((nicsr & ~IM & ~LED) | IEN);
		outb(nicsr, DEPCA_NICSR);
		outw(CSR0, DEPCA_ADDR);

		netif_start_queue(dev);

		status = InitRestartDepca(dev);

		if (depca_debug > 1) {
			printk("CSR0: 0x%4.4x\n", inw(DEPCA_DATA));
			printk("nicsr: 0x%02x\n", inb(DEPCA_NICSR));
		}
	}
	return status;
}

/* Initialize the lance Rx and Tx descriptor rings. */
static void depca_init_ring(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_int i;
	u_long offset;

	/* Lock out other processes whilst setting up the hardware */
	netif_stop_queue(dev);

	lp->rx_new = lp->tx_new = 0;
	lp->rx_old = lp->tx_old = 0;

	/* Initialize the base address and length of each buffer in the ring */
	for (i = 0; i <= lp->rxRingMask; i++) {
		offset = lp->buffs_offset + i * RX_BUFF_SZ;
		writel((lp->device_ram_start + offset) | R_OWN, &lp->rx_ring[i].base);
		writew(-RX_BUFF_SZ, &lp->rx_ring[i].buf_length);
		lp->rx_buff[i] = lp->sh_mem + offset;
	}

	for (i = 0; i <= lp->txRingMask; i++) {
		offset = lp->buffs_offset + (i + lp->rxRingMask + 1) * TX_BUFF_SZ;
		writel((lp->device_ram_start + offset) & 0x00ffffff, &lp->tx_ring[i].base);
		lp->tx_buff[i] = lp->sh_mem + offset;
	}

	/* Set up the initialization block */
	lp->init_block.rx_ring = (lp->device_ram_start + lp->rx_ring_offset) | lp->rx_rlen;
	lp->init_block.tx_ring = (lp->device_ram_start + lp->tx_ring_offset) | lp->tx_rlen;

	SetMulticastFilter(dev);

	for (i = 0; i < ETH_ALEN; i++) {
		lp->init_block.phys_addr[i] = dev->dev_addr[i];
	}

	lp->init_block.mode = 0x0000;	/* Enable the Tx and Rx */
}


static void depca_tx_timeout(struct net_device *dev)
{
	u_long ioaddr = dev->base_addr;

	printk("%s: transmit timed out, status %04x, resetting.\n", dev->name, inw(DEPCA_DATA));

	STOP_DEPCA;
	depca_init_ring(dev);
	LoadCSRs(dev);
	dev->trans_start = jiffies;
	netif_wake_queue(dev);
	InitRestartDepca(dev);
}


/*
** Writes a socket buffer to TX descriptor ring and starts transmission
*/
static int depca_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;
	int status = 0;

	/* Transmitter timeout, serious problems. */
	if (skb->len < 1)
		goto out;

	if (skb_padto(skb, ETH_ZLEN))
		goto out;

	netif_stop_queue(dev);

	if (TX_BUFFS_AVAIL) {	/* Fill in a Tx ring entry */
		status = load_packet(dev, skb);

		if (!status) {
			/* Trigger an immediate send demand. */
			outw(CSR0, DEPCA_ADDR);
			outw(INEA | TDMD, DEPCA_DATA);

			dev->trans_start = jiffies;
			dev_kfree_skb(skb);
		}
		if (TX_BUFFS_AVAIL)
			netif_start_queue(dev);
	} else
		status = -1;

      out:
	return status;
}

/*
** The DEPCA interrupt handler.
*/
static irqreturn_t depca_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct depca_private *lp;
	s16 csr0, nicsr;
	u_long ioaddr;

	if (dev == NULL) {
		printk("depca_interrupt(): irq %d for unknown device.\n", irq);
		return IRQ_NONE;
	}

	lp = (struct depca_private *) dev->priv;
	ioaddr = dev->base_addr;

	spin_lock(&lp->lock);

	/* mask the DEPCA board interrupts and turn on the LED */
	nicsr = inb(DEPCA_NICSR);
	nicsr |= (IM | LED);
	outb(nicsr, DEPCA_NICSR);

	outw(CSR0, DEPCA_ADDR);
	csr0 = inw(DEPCA_DATA);

	/* Acknowledge all of the current interrupt sources ASAP. */
	outw(csr0 & INTE, DEPCA_DATA);

	if (csr0 & RINT)	/* Rx interrupt (packet arrived) */
		depca_rx(dev);

	if (csr0 & TINT)	/* Tx interrupt (packet sent) */
		depca_tx(dev);

	/* Any resources available? */
	if ((TX_BUFFS_AVAIL >= 0) && netif_queue_stopped(dev)) {
		netif_wake_queue(dev);
	}

	/* Unmask the DEPCA board interrupts and turn off the LED */
	nicsr = (nicsr & ~IM & ~LED);
	outb(nicsr, DEPCA_NICSR);

	spin_unlock(&lp->lock);
	return IRQ_HANDLED;
}

/* Called with lp->lock held */
static int depca_rx(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	int i, entry;
	s32 status;

	for (entry = lp->rx_new; !(readl(&lp->rx_ring[entry].base) & R_OWN); entry = lp->rx_new) {
		status = readl(&lp->rx_ring[entry].base) >> 16;
		if (status & R_STP) {	/* Remember start of frame */
			lp->rx_old = entry;
		}
		if (status & R_ENP) {	/* Valid frame status */
			if (status & R_ERR) {	/* There was an error. */
				lp->stats.rx_errors++;	/* Update the error stats. */
				if (status & R_FRAM)
					lp->stats.rx_frame_errors++;
				if (status & R_OFLO)
					lp->stats.rx_over_errors++;
				if (status & R_CRC)
					lp->stats.rx_crc_errors++;
				if (status & R_BUFF)
					lp->stats.rx_fifo_errors++;
			} else {
				short len, pkt_len = readw(&lp->rx_ring[entry].msg_length) - 4;
				struct sk_buff *skb;

				skb = dev_alloc_skb(pkt_len + 2);
				if (skb != NULL) {
					unsigned char *buf;
					skb_reserve(skb, 2);	/* 16 byte align the IP header */
					buf = skb_put(skb, pkt_len);
					skb->dev = dev;
					if (entry < lp->rx_old) {	/* Wrapped buffer */
						len = (lp->rxRingMask - lp->rx_old + 1) * RX_BUFF_SZ;
						memcpy_fromio(buf, lp->rx_buff[lp->rx_old], len);
						memcpy_fromio(buf + len, lp->rx_buff[0], pkt_len - len);
					} else {	/* Linear buffer */
						memcpy_fromio(buf, lp->rx_buff[lp->rx_old], pkt_len);
					}

					/*
					   ** Notify the upper protocol layers that there is another
					   ** packet to handle
					 */
					skb->protocol = eth_type_trans(skb, dev);
					netif_rx(skb);

					/*
					   ** Update stats
					 */
					dev->last_rx = jiffies;
					lp->stats.rx_packets++;
					lp->stats.rx_bytes += pkt_len;
					for (i = 1; i < DEPCA_PKT_STAT_SZ - 1; i++) {
						if (pkt_len < (i * DEPCA_PKT_BIN_SZ)) {
							lp->pktStats.bins[i]++;
							i = DEPCA_PKT_STAT_SZ;
						}
					}
					if (buf[0] & 0x01) {	/* Multicast/Broadcast */
						if ((*(s16 *) & buf[0] == -1) && (*(s16 *) & buf[2] == -1) && (*(s16 *) & buf[4] == -1)) {
							lp->pktStats.broadcast++;
						} else {
							lp->pktStats.multicast++;
						}
					} else if ((*(s16 *) & buf[0] == *(s16 *) & dev->dev_addr[0]) && (*(s16 *) & buf[2] == *(s16 *) & dev->dev_addr[2]) && (*(s16 *) & buf[4] == *(s16 *) & dev->dev_addr[4])) {
						lp->pktStats.unicast++;
					}

					lp->pktStats.bins[0]++;	/* Duplicates stats.rx_packets */
					if (lp->pktStats.bins[0] == 0) {	/* Reset counters */
						memset((char *) &lp->pktStats, 0, sizeof(lp->pktStats));
					}
				} else {
					printk("%s: Memory squeeze, deferring packet.\n", dev->name);
					lp->stats.rx_dropped++;	/* Really, deferred. */
					break;
				}
			}
			/* Change buffer ownership for this last frame, back to the adapter */
			for (; lp->rx_old != entry; lp->rx_old = (++lp->rx_old) & lp->rxRingMask) {
				writel(readl(&lp->rx_ring[lp->rx_old].base) | R_OWN, &lp->rx_ring[lp->rx_old].base);
			}
			writel(readl(&lp->rx_ring[entry].base) | R_OWN, &lp->rx_ring[entry].base);
		}

		/*
		   ** Update entry information
		 */
		lp->rx_new = (++lp->rx_new) & lp->rxRingMask;
	}

	return 0;
}

/*
** Buffer sent - check for buffer errors.
** Called with lp->lock held
*/
static int depca_tx(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	int entry;
	s32 status;
	u_long ioaddr = dev->base_addr;

	for (entry = lp->tx_old; entry != lp->tx_new; entry = lp->tx_old) {
		status = readl(&lp->tx_ring[entry].base) >> 16;

		if (status < 0) {	/* Packet not yet sent! */
			break;
		} else if (status & T_ERR) {	/* An error occurred. */
			status = readl(&lp->tx_ring[entry].misc);
			lp->stats.tx_errors++;
			if (status & TMD3_RTRY)
				lp->stats.tx_aborted_errors++;
			if (status & TMD3_LCAR)
				lp->stats.tx_carrier_errors++;
			if (status & TMD3_LCOL)
				lp->stats.tx_window_errors++;
			if (status & TMD3_UFLO)
				lp->stats.tx_fifo_errors++;
			if (status & (TMD3_BUFF | TMD3_UFLO)) {
				/* Trigger an immediate send demand. */
				outw(CSR0, DEPCA_ADDR);
				outw(INEA | TDMD, DEPCA_DATA);
			}
		} else if (status & (T_MORE | T_ONE)) {
			lp->stats.collisions++;
		} else {
			lp->stats.tx_packets++;
		}

		/* Update all the pointers */
		lp->tx_old = (++lp->tx_old) & lp->txRingMask;
	}

	return 0;
}

static int depca_close(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	s16 nicsr;
	u_long ioaddr = dev->base_addr;

	netif_stop_queue(dev);

	outw(CSR0, DEPCA_ADDR);

	if (depca_debug > 1) {
		printk("%s: Shutting down ethercard, status was %2.2x.\n", dev->name, inw(DEPCA_DATA));
	}

	/*
	   ** We stop the DEPCA here -- it occasionally polls
	   ** memory if we don't.
	 */
	outw(STOP, DEPCA_DATA);

	/*
	   ** Give back the ROM in case the user wants to go to DOS
	 */
	if (lp->adapter != DEPCA) {
		nicsr = inb(DEPCA_NICSR);
		nicsr &= ~SHE;
		outb(nicsr, DEPCA_NICSR);
	}

	/*
	   ** Free the associated irq
	 */
	free_irq(dev->irq, dev);
	return 0;
}

static void LoadCSRs(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;

	outw(CSR1, DEPCA_ADDR);	/* initialisation block address LSW */
	outw((u16) lp->device_ram_start, DEPCA_DATA);
	outw(CSR2, DEPCA_ADDR);	/* initialisation block address MSW */
	outw((u16) (lp->device_ram_start >> 16), DEPCA_DATA);
	outw(CSR3, DEPCA_ADDR);	/* ALE control */
	outw(ACON, DEPCA_DATA);

	outw(CSR0, DEPCA_ADDR);	/* Point back to CSR0 */

	return;
}

static int InitRestartDepca(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;
	int i, status = 0;

	/* Copy the shadow init_block to shared memory */
	memcpy_toio(lp->sh_mem, &lp->init_block, sizeof(struct depca_init));

	outw(CSR0, DEPCA_ADDR);	/* point back to CSR0 */
	outw(INIT, DEPCA_DATA);	/* initialize DEPCA */

	/* wait for lance to complete initialisation */
	for (i = 0; (i < 100) && !(inw(DEPCA_DATA) & IDON); i++);

	if (i != 100) {
		/* clear IDON by writing a "1", enable interrupts and start lance */
		outw(IDON | INEA | STRT, DEPCA_DATA);
		if (depca_debug > 2) {
			printk("%s: DEPCA open after %d ticks, init block 0x%08lx csr0 %4.4x.\n", dev->name, i, lp->mem_start, inw(DEPCA_DATA));
		}
	} else {
		printk("%s: DEPCA unopen after %d ticks, init block 0x%08lx csr0 %4.4x.\n", dev->name, i, lp->mem_start, inw(DEPCA_DATA));
		status = -1;
	}

	return status;
}

static struct net_device_stats *depca_get_stats(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;

	/* Null body since there is no framing error counter */

	return &lp->stats;
}

/*
** Set or clear the multicast filter for this adaptor.
*/
static void set_multicast_list(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;

	netif_stop_queue(dev);
	while (lp->tx_old != lp->tx_new);	/* Wait for the ring to empty */

	STOP_DEPCA;	/* Temporarily stop the depca.  */
	depca_init_ring(dev);	/* Initialize the descriptor rings */

	if (dev->flags & IFF_PROMISC) {	/* Set promiscuous mode */
		lp->init_block.mode |= PROM;
	} else {
		SetMulticastFilter(dev);
		lp->init_block.mode &= ~PROM;	/* Unset promiscuous mode */
	}

	LoadCSRs(dev);	/* Reload CSR3 */
	InitRestartDepca(dev);	/* Resume normal operation. */
	netif_start_queue(dev);	/* Unlock the TX ring */
}

/*
** Calculate the hash code and update the logical address filter
** from a list of ethernet multicast addresses.
** Big endian crc one liner is mine, all mine, ha ha ha ha!
** LANCE calculates its hash codes big endian.
*/
static void SetMulticastFilter(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	struct dev_mc_list *dmi = dev->mc_list;
	char *addrs;
	int i, j, bit, byte;
	u16 hashcode;
	u32 crc;

	if (dev->flags & IFF_ALLMULTI) {	/* Set all multicast bits */
		for (i = 0; i < (HASH_TABLE_LEN >> 3); i++) {
			lp->init_block.mcast_table[i] = (char) 0xff;
		}
	} else {
		for (i = 0; i < (HASH_TABLE_LEN >> 3); i++) {	/* Clear the multicast table */
			lp->init_block.mcast_table[i] = 0;
		}
		/* Add multicast addresses */
		for (i = 0; i < dev->mc_count; i++) {	/* for each address in the list */
			addrs = dmi->dmi_addr;
			dmi = dmi->next;
			if ((*addrs & 0x01) == 1) {	/* multicast address? */
				crc = ether_crc(ETH_ALEN, addrs);
				hashcode = (crc & 1);	/* hashcode is 6 LSb of CRC ... */
				for (j = 0; j < 5; j++) {	/* ... in reverse order. */
					hashcode = (hashcode << 1) | ((crc >>= 1) & 1);
				}


				byte = hashcode >> 3;	/* bit[3-5] -> byte in filter */
				bit = 1 << (hashcode & 0x07);	/* bit[0-2] -> bit in byte */
				lp->init_block.mcast_table[byte] |= bit;
			}
		}
	}

	return;
}

static int __init depca_common_init (u_long ioaddr, struct net_device **devp)
{
	int status = 0;

	if (!request_region (ioaddr, DEPCA_TOTAL_SIZE, depca_string)) {
		status = -EBUSY;
		goto out;
	}

	if (DevicePresent(ioaddr)) {
		status = -ENODEV;
		goto out_release;
	}

	if (!(*devp = alloc_etherdev (sizeof (struct depca_private)))) {
		status = -ENOMEM;
		goto out_release;
	}

	return 0;

 out_release:
	release_region (ioaddr, DEPCA_TOTAL_SIZE);
 out:
	return status;
}

#ifdef CONFIG_MCA
/*
** Microchannel bus I/O device probe
*/
static int __init depca_mca_probe(struct device *device)
{
	unsigned char pos[2];
	unsigned char where;
	unsigned long iobase, mem_start;
	int irq, err;
	struct mca_device *mdev = to_mca_device (device);
	struct net_device *dev;
	struct depca_private *lp;

	/*
	** Search for the adapter.  If an address has been given, search
	** specifically for the card at that address.  Otherwise find the
	** first card in the system.
	*/

	pos[0] = mca_device_read_stored_pos(mdev, 2);
	pos[1] = mca_device_read_stored_pos(mdev, 3);

	/*
	** IO of card is handled by bits 1 and 2 of pos0.
	**
	**    bit2 bit1    IO
	**       0    0    0x2c00
	**       0    1    0x2c10
	**       1    0    0x2c20
	**       1    1    0x2c30
	*/
	where = (pos[0] & 6) >> 1;
	iobase = 0x2c00 + (0x10 * where);

	/*
	** Found the adapter we were looking for. Now start setting it up.
	**
	** First work on decoding the IRQ.  It's stored in the lower 4 bits
	** of pos1.  Bits are as follows (from the ADF file):
	**
	**      Bits
	**   3   2   1   0    IRQ
	**   --------------------
	**   0   0   1   0     5
	**   0   0   0   1     9
	**   0   1   0   0    10
	**   1   0   0   0    11
	*/
	where = pos[1] & 0x0f;
	switch (where) {
	case 1:
		irq = 9;
		break;
	case 2:
		irq = 5;
		break;
	case 4:
		irq = 10;
		break;
	case 8:
		irq = 11;
		break;
	default:
		printk("%s: mca_probe IRQ error.  You should never get here (%d).\n", mdev->name, where);
		return -EINVAL;
	}

	/*
	** Shared memory address of adapter is stored in bits 3-5 of pos0.
	** They are mapped as follows:
	**
	**    Bit
	**   5  4  3       Memory Addresses
	**   0  0  0       C0000-CFFFF (64K)
	**   1  0  0       C8000-CFFFF (32K)
	**   0  0  1       D0000-DFFFF (64K)
	**   1  0  1       D8000-DFFFF (32K)
	**   0  1  0       E0000-EFFFF (64K)
	**   1  1  0       E8000-EFFFF (32K)
	*/
	where = (pos[0] & 0x18) >> 3;
	mem_start = 0xc0000 + (where * 0x10000);
	if (pos[0] & 0x20) {
		mem_start += 0x8000;
	}

	/* claim the slot */
	strncpy(mdev->name, depca_mca_adapter_name[mdev->index],
		sizeof(mdev->name));
	mca_device_set_claim(mdev, 1);

        /*
	** Get everything allocated and initialized...  (almost just
	** like the ISA and EISA probes)
	*/
	irq = mca_device_transform_irq(mdev, irq);
	iobase = mca_device_transform_ioport(mdev, iobase);

	if ((err = depca_common_init (iobase, &dev)))
		goto out_unclaim;

	dev->irq = irq;
	dev->base_addr = iobase;
	lp = dev->priv;
	lp->depca_bus = DEPCA_BUS_MCA;
	lp->adapter = depca_mca_adapter_type[mdev->index];
	lp->mem_start = mem_start;

	if ((err = depca_hw_init(dev, device)))
		goto out_free;

	return 0;

 out_free:
	free_netdev (dev);
	release_region (iobase, DEPCA_TOTAL_SIZE);
 out_unclaim:
	mca_device_set_claim(mdev, 0);

	return err;
}
#endif

/*
** ISA bus I/O device probe
*/

static void __init depca_platform_probe (void)
{
	int i;
	struct platform_device *pldev;

	for (i = 0; depca_io_ports[i].iobase; i++) {
		depca_io_ports[i].device = NULL;

		/* if an address has been specified on the command
		 * line, use it (if valid) */
		if (io && io != depca_io_ports[i].iobase)
			continue;

		pldev = platform_device_alloc(depca_string, i);
		if (!pldev)
			continue;

		pldev->dev.platform_data = (void *) depca_io_ports[i].iobase;
		depca_io_ports[i].device = pldev;

		if (platform_device_add(pldev)) {
			platform_device_put(pldev);
			depca_io_ports[i].device = NULL;
			continue;
		}

		if (!pldev->dev.driver) {
		/* The driver was not bound to this device, there was
		 * no hardware at this address. Unregister it, as the
		 * release fuction will take care of freeing the
		 * allocated structure */

			depca_io_ports[i].device = NULL;
			pldev->dev.platform_data = NULL;
			platform_device_unregister (pldev);
		}
	}
}

static enum depca_type __init depca_shmem_probe (ulong *mem_start)
{
	u_long mem_base[] = DEPCA_RAM_BASE_ADDRESSES;
	enum depca_type adapter = unknown;
	int i;

	for (i = 0; mem_base[i]; i++) {
		*mem_start = mem ? mem : mem_base[i];
		adapter = DepcaSignature (adapter_name, *mem_start);
		if (adapter != unknown)
			break;
	}

	return adapter;
}

static int __init depca_isa_probe (struct platform_device *device)
{
	struct net_device *dev;
	struct depca_private *lp;
	u_long ioaddr, mem_start = 0;
	enum depca_type adapter = unknown;
	int status = 0;

	ioaddr = (u_long) device->dev.platform_data;

	if ((status = depca_common_init (ioaddr, &dev)))
		goto out;

	adapter = depca_shmem_probe (&mem_start);

	if (adapter == unknown) {
		status = -ENODEV;
		goto out_free;
	}

	dev->base_addr = ioaddr;
	dev->irq = irq;		/* Use whatever value the user gave
				 * us, and 0 if he didn't. */
	lp = dev->priv;
	lp->depca_bus = DEPCA_BUS_ISA;
	lp->adapter = adapter;
	lp->mem_start = mem_start;

	if ((status = depca_hw_init(dev, &device->dev)))
		goto out_free;

	return 0;

 out_free:
	free_netdev (dev);
	release_region (ioaddr, DEPCA_TOTAL_SIZE);
 out:
	return status;
}

/*
** EISA callbacks from sysfs.
*/

#ifdef CONFIG_EISA
static int __init depca_eisa_probe (struct device *device)
{
	struct eisa_device *edev;
	struct net_device *dev;
	struct depca_private *lp;
	u_long ioaddr, mem_start;
	int status = 0;

	edev = to_eisa_device (device);
	ioaddr = edev->base_addr + DEPCA_EISA_IO_PORTS;

	if ((status = depca_common_init (ioaddr, &dev)))
		goto out;

	/* It would have been nice to get card configuration from the
	 * card. Unfortunately, this register is write-only (shares
	 * it's address with the ethernet prom)... As we don't parse
	 * the EISA configuration structures (yet... :-), just rely on
	 * the ISA probing to sort it out... */

	depca_shmem_probe (&mem_start);

	dev->base_addr = ioaddr;
	dev->irq = irq;
	lp = dev->priv;
	lp->depca_bus = DEPCA_BUS_EISA;
	lp->adapter = edev->id.driver_data;
	lp->mem_start = mem_start;

	if ((status = depca_hw_init(dev, device)))
		goto out_free;

	return 0;

 out_free:
	free_netdev (dev);
	release_region (ioaddr, DEPCA_TOTAL_SIZE);
 out:
	return status;
}
#endif

static int __devexit depca_device_remove (struct device *device)
{
	struct net_device *dev;
	struct depca_private *lp;
	int bus;

	dev  = device->driver_data;
	lp   = dev->priv;

	unregister_netdev (dev);
	iounmap (lp->sh_mem);
	release_mem_region (lp->mem_start, lp->mem_len);
	release_region (dev->base_addr, DEPCA_TOTAL_SIZE);
	bus = lp->depca_bus;
	free_netdev (dev);

	return 0;
}

/*
** Look for a particular board name in the on-board Remote Diagnostics
** and Boot (readb) ROM. This will also give us a clue to the network RAM
** base address.
*/
static int __init DepcaSignature(char *name, u_long base_addr)
{
	u_int i, j, k;
	void __iomem *ptr;
	char tmpstr[16];
	u_long prom_addr = base_addr + 0xc000;
	u_long mem_addr = base_addr + 0x8000; /* 32KB */

	/* Can't reserve the prom region, it is already marked as
	 * used, at least on x86. Instead, reserve a memory region a
	 * board would certainly use. If it works, go ahead. If not,
	 * run like hell... */

	if (!request_mem_region (mem_addr, 16, depca_string))
		return unknown;

	/* Copy the first 16 bytes of ROM */

	ptr = ioremap(prom_addr, 16);
	if (ptr == NULL) {
		printk(KERN_ERR "depca: I/O remap failed at %lx\n", prom_addr);
		return unknown;
	}
	for (i = 0; i < 16; i++) {
		tmpstr[i] = readb(ptr + i);
	}
	iounmap(ptr);

	release_mem_region (mem_addr, 16);

	/* Check if PROM contains a valid string */
	for (i = 0; *depca_signature[i] != '\0'; i++) {
		for (j = 0, k = 0; j < 16 && k < strlen(depca_signature[i]); j++) {
			if (depca_signature[i][k] == tmpstr[j]) {	/* track signature */
				k++;
			} else {	/* lost signature; begin search again */
				k = 0;
			}
		}
		if (k == strlen(depca_signature[i]))
			break;
	}

	/* Check if name string is valid, provided there's no PROM */
	if (name && *name && (i == unknown)) {
		for (i = 0; *depca_signature[i] != '\0'; i++) {
			if (strcmp(name, depca_signature[i]) == 0)
				break;
		}
	}

	return i;
}

/*
** Look for a special sequence in the Ethernet station address PROM that
** is common across all DEPCA products. Note that the original DEPCA needs
** its ROM address counter to be initialized and enabled. Only enable
** if the first address octet is a 0x08 - this minimises the chances of
** messing around with some other hardware, but it assumes that this DEPCA
** card initialized itself correctly.
**
** Search the Ethernet address ROM for the signature. Since the ROM address
** counter can start at an arbitrary point, the search must include the entire
** probe sequence length plus the (length_of_the_signature - 1).
** Stop the search IMMEDIATELY after the signature is found so that the
** PROM address counter is correctly positioned at the start of the
** ethernet address for later read out.
*/
static int __init DevicePresent(u_long ioaddr)
{
	union {
		struct {
			u32 a;
			u32 b;
		} llsig;
		char Sig[sizeof(u32) << 1];
	}
	dev;
	short sigLength = 0;
	s8 data;
	s16 nicsr;
	int i, j, status = 0;

	data = inb(DEPCA_PROM);	/* clear counter on DEPCA */
	data = inb(DEPCA_PROM);	/* read data */

	if (data == 0x08) {	/* Enable counter on DEPCA */
		nicsr = inb(DEPCA_NICSR);
		nicsr |= AAC;
		outb(nicsr, DEPCA_NICSR);
	}

	dev.llsig.a = ETH_PROM_SIG;
	dev.llsig.b = ETH_PROM_SIG;
	sigLength = sizeof(u32) << 1;

	for (i = 0, j = 0; j < sigLength && i < PROBE_LENGTH + sigLength - 1; i++) {
		data = inb(DEPCA_PROM);
		if (dev.Sig[j] == data) {	/* track signature */
			j++;
		} else {	/* lost signature; begin search again */
			if (data == dev.Sig[0]) {	/* rare case.... */
				j = 1;
			} else {
				j = 0;
			}
		}
	}

	if (j != sigLength) {
		status = -ENODEV;	/* search failed */
	}

	return status;
}

/*
** The DE100 and DE101 PROM accesses were made non-standard for some bizarre
** reason: access the upper half of the PROM with x=0; access the lower half
** with x=1.
*/
static int __init get_hw_addr(struct net_device *dev)
{
	u_long ioaddr = dev->base_addr;
	struct depca_private *lp = dev->priv;
	int i, k, tmp, status = 0;
	u_short j, x, chksum;

	x = (((lp->adapter == de100) || (lp->adapter == de101)) ? 1 : 0);

	for (i = 0, k = 0, j = 0; j < 3; j++) {
		k <<= 1;
		if (k > 0xffff)
			k -= 0xffff;

		k += (u_char) (tmp = inb(DEPCA_PROM + x));
		dev->dev_addr[i++] = (u_char) tmp;
		k += (u_short) ((tmp = inb(DEPCA_PROM + x)) << 8);
		dev->dev_addr[i++] = (u_char) tmp;

		if (k > 0xffff)
			k -= 0xffff;
	}
	if (k == 0xffff)
		k = 0;

	chksum = (u_char) inb(DEPCA_PROM + x);
	chksum |= (u_short) (inb(DEPCA_PROM + x) << 8);
	if (k != chksum)
		status = -1;

	return status;
}

/*
** Load a packet into the shared memory
*/
static int load_packet(struct net_device *dev, struct sk_buff *skb)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	int i, entry, end, len, status = 0;

	entry = lp->tx_new;	/* Ring around buffer number. */
	end = (entry + (skb->len - 1) / TX_BUFF_SZ) & lp->txRingMask;
	if (!(readl(&lp->tx_ring[end].base) & T_OWN)) {	/* Enough room? */
		/*
		   ** Caution: the write order is important here... don't set up the
		   ** ownership rights until all the other information is in place.
		 */
		if (end < entry) {	/* wrapped buffer */
			len = (lp->txRingMask - entry + 1) * TX_BUFF_SZ;
			memcpy_toio(lp->tx_buff[entry], skb->data, len);
			memcpy_toio(lp->tx_buff[0], skb->data + len, skb->len - len);
		} else {	/* linear buffer */
			memcpy_toio(lp->tx_buff[entry], skb->data, skb->len);
		}

		/* set up the buffer descriptors */
		len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
		for (i = entry; i != end; i = (i+1) & lp->txRingMask) {
			/* clean out flags */
			writel(readl(&lp->tx_ring[i].base) & ~T_FLAGS, &lp->tx_ring[i].base);
			writew(0x0000, &lp->tx_ring[i].misc);	/* clears other error flags */
			writew(-TX_BUFF_SZ, &lp->tx_ring[i].length);	/* packet length in buffer */
			len -= TX_BUFF_SZ;
		}
		/* clean out flags */
		writel(readl(&lp->tx_ring[end].base) & ~T_FLAGS, &lp->tx_ring[end].base);
		writew(0x0000, &lp->tx_ring[end].misc);	/* clears other error flags */
		writew(-len, &lp->tx_ring[end].length);	/* packet length in last buff */

		/* start of packet */
		writel(readl(&lp->tx_ring[entry].base) | T_STP, &lp->tx_ring[entry].base);
		/* end of packet */
		writel(readl(&lp->tx_ring[end].base) | T_ENP, &lp->tx_ring[end].base);

		for (i = end; i != entry; --i) {
			/* ownership of packet */
			writel(readl(&lp->tx_ring[i].base) | T_OWN, &lp->tx_ring[i].base);
			if (i == 0)
				i = lp->txRingMask + 1;
		}
		writel(readl(&lp->tx_ring[entry].base) | T_OWN, &lp->tx_ring[entry].base);

		lp->tx_new = (++end) & lp->txRingMask;	/* update current pointers */
	} else {
		status = -1;
	}

	return status;
}

static void depca_dbg_open(struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;
	struct depca_init *p = &lp->init_block;
	int i;

	if (depca_debug > 1) {
		/* Do not copy the shadow init block into shared memory */
		/* Debugging should not affect normal operation! */
		/* The shadow init block will get copied across during InitRestartDepca */
		printk("%s: depca open with irq %d\n", dev->name, dev->irq);
		printk("Descriptor head addresses (CPU):\n");
		printk("        0x%lx  0x%lx\n", (u_long) lp->rx_ring, (u_long) lp->tx_ring);
		printk("Descriptor addresses (CPU):\nRX: ");
		for (i = 0; i < lp->rxRingMask; i++) {
			if (i < 3) {
				printk("%p ", &lp->rx_ring[i].base);
			}
		}
		printk("...%p\n", &lp->rx_ring[i].base);
		printk("TX: ");
		for (i = 0; i < lp->txRingMask; i++) {
			if (i < 3) {
				printk("%p ", &lp->tx_ring[i].base);
			}
		}
		printk("...%p\n", &lp->tx_ring[i].base);
		printk("\nDescriptor buffers (Device):\nRX: ");
		for (i = 0; i < lp->rxRingMask; i++) {
			if (i < 3) {
				printk("0x%8.8x  ", readl(&lp->rx_ring[i].base));
			}
		}
		printk("...0x%8.8x\n", readl(&lp->rx_ring[i].base));
		printk("TX: ");
		for (i = 0; i < lp->txRingMask; i++) {
			if (i < 3) {
				printk("0x%8.8x  ", readl(&lp->tx_ring[i].base));
			}
		}
		printk("...0x%8.8x\n", readl(&lp->tx_ring[i].base));
		printk("Initialisation block at 0x%8.8lx(Phys)\n", lp->mem_start);
		printk("        mode: 0x%4.4x\n", p->mode);
		printk("        physical address: ");
		for (i = 0; i < ETH_ALEN - 1; i++) {
			printk("%2.2x:", p->phys_addr[i]);
		}
		printk("%2.2x\n", p->phys_addr[i]);
		printk("        multicast hash table: ");
		for (i = 0; i < (HASH_TABLE_LEN >> 3) - 1; i++) {
			printk("%2.2x:", p->mcast_table[i]);
		}
		printk("%2.2x\n", p->mcast_table[i]);
		printk("        rx_ring at: 0x%8.8x\n", p->rx_ring);
		printk("        tx_ring at: 0x%8.8x\n", p->tx_ring);
		printk("buffers (Phys): 0x%8.8lx\n", lp->mem_start + lp->buffs_offset);
		printk("Ring size:\nRX: %d  Log2(rxRingMask): 0x%8.8x\n", (int) lp->rxRingMask + 1, lp->rx_rlen);
		printk("TX: %d  Log2(txRingMask): 0x%8.8x\n", (int) lp->txRingMask + 1, lp->tx_rlen);
		outw(CSR2, DEPCA_ADDR);
		printk("CSR2&1: 0x%4.4x", inw(DEPCA_DATA));
		outw(CSR1, DEPCA_ADDR);
		printk("%4.4x\n", inw(DEPCA_DATA));
		outw(CSR3, DEPCA_ADDR);
		printk("CSR3: 0x%4.4x\n", inw(DEPCA_DATA));
	}

	return;
}

/*
** Perform IOCTL call functions here. Some are privileged operations and the
** effective uid is checked in those cases.
** All multicast IOCTLs will not work here and are for testing purposes only.
*/
static int depca_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	struct depca_ioctl *ioc = (struct depca_ioctl *) &rq->ifr_ifru;
	int i, status = 0;
	u_long ioaddr = dev->base_addr;
	union {
		u8 addr[(HASH_TABLE_LEN * ETH_ALEN)];
		u16 sval[(HASH_TABLE_LEN * ETH_ALEN) >> 1];
		u32 lval[(HASH_TABLE_LEN * ETH_ALEN) >> 2];
	} tmp;
	unsigned long flags;
	void *buf;

	switch (ioc->cmd) {
	case DEPCA_GET_HWADDR:	/* Get the hardware address */
		for (i = 0; i < ETH_ALEN; i++) {
			tmp.addr[i] = dev->dev_addr[i];
		}
		ioc->len = ETH_ALEN;
		if (copy_to_user(ioc->data, tmp.addr, ioc->len))
			return -EFAULT;
		break;

	case DEPCA_SET_HWADDR:	/* Set the hardware address */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (copy_from_user(tmp.addr, ioc->data, ETH_ALEN))
			return -EFAULT;
		for (i = 0; i < ETH_ALEN; i++) {
			dev->dev_addr[i] = tmp.addr[i];
		}
		netif_stop_queue(dev);
		while (lp->tx_old != lp->tx_new)
			cpu_relax();	/* Wait for the ring to empty */

		STOP_DEPCA;	/* Temporarily stop the depca.  */
		depca_init_ring(dev);	/* Initialize the descriptor rings */
		LoadCSRs(dev);	/* Reload CSR3 */
		InitRestartDepca(dev);	/* Resume normal operation. */
		netif_start_queue(dev);	/* Unlock the TX ring */
		break;

	case DEPCA_SET_PROM:	/* Set Promiscuous Mode */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		netif_stop_queue(dev);
		while (lp->tx_old != lp->tx_new)
			cpu_relax();	/* Wait for the ring to empty */

		STOP_DEPCA;	/* Temporarily stop the depca.  */
		depca_init_ring(dev);	/* Initialize the descriptor rings */
		lp->init_block.mode |= PROM;	/* Set promiscuous mode */

		LoadCSRs(dev);	/* Reload CSR3 */
		InitRestartDepca(dev);	/* Resume normal operation. */
		netif_start_queue(dev);	/* Unlock the TX ring */
		break;

	case DEPCA_CLR_PROM:	/* Clear Promiscuous Mode */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		netif_stop_queue(dev);
		while (lp->tx_old != lp->tx_new)
			cpu_relax();	/* Wait for the ring to empty */

		STOP_DEPCA;	/* Temporarily stop the depca.  */
		depca_init_ring(dev);	/* Initialize the descriptor rings */
		lp->init_block.mode &= ~PROM;	/* Clear promiscuous mode */

		LoadCSRs(dev);	/* Reload CSR3 */
		InitRestartDepca(dev);	/* Resume normal operation. */
		netif_start_queue(dev);	/* Unlock the TX ring */
		break;

	case DEPCA_SAY_BOO:	/* Say "Boo!" to the kernel log file */
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
		printk("%s: Boo!\n", dev->name);
		break;

	case DEPCA_GET_MCA:	/* Get the multicast address table */
		ioc->len = (HASH_TABLE_LEN >> 3);
		if (copy_to_user(ioc->data, lp->init_block.mcast_table, ioc->len))
			return -EFAULT;
		break;

	case DEPCA_SET_MCA:	/* Set a multicast address */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (ioc->len >= HASH_TABLE_LEN)
			return -EINVAL;
		if (copy_from_user(tmp.addr, ioc->data, ETH_ALEN * ioc->len))
			return -EFAULT;
		set_multicast_list(dev);
		break;

	case DEPCA_CLR_MCA:	/* Clear all multicast addresses */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		set_multicast_list(dev);
		break;

	case DEPCA_MCA_EN:	/* Enable pass all multicast addressing */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		set_multicast_list(dev);
		break;

	case DEPCA_GET_STATS:	/* Get the driver statistics */
		ioc->len = sizeof(lp->pktStats);
		buf = kmalloc(ioc->len, GFP_KERNEL);
		if(!buf)
			return -ENOMEM;
		spin_lock_irqsave(&lp->lock, flags);
		memcpy(buf, &lp->pktStats, ioc->len);
		spin_unlock_irqrestore(&lp->lock, flags);
		if (copy_to_user(ioc->data, buf, ioc->len))
			status = -EFAULT;
		kfree(buf);
		break;

	case DEPCA_CLR_STATS:	/* Zero out the driver statistics */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		spin_lock_irqsave(&lp->lock, flags);
		memset(&lp->pktStats, 0, sizeof(lp->pktStats));
		spin_unlock_irqrestore(&lp->lock, flags);
		break;

	case DEPCA_GET_REG:	/* Get the DEPCA Registers */
		i = 0;
		tmp.sval[i++] = inw(DEPCA_NICSR);
		outw(CSR0, DEPCA_ADDR);	/* status register */
		tmp.sval[i++] = inw(DEPCA_DATA);
		memcpy(&tmp.sval[i], &lp->init_block, sizeof(struct depca_init));
		ioc->len = i + sizeof(struct depca_init);
		if (copy_to_user(ioc->data, tmp.addr, ioc->len))
			return -EFAULT;
		break;

	default:
		return -EOPNOTSUPP;
	}

	return status;
}

static int __init depca_module_init (void)
{
        int err = 0;

#ifdef CONFIG_MCA
        err = mca_register_driver (&depca_mca_driver);
#endif
#ifdef CONFIG_EISA
        err |= eisa_driver_register (&depca_eisa_driver);
#endif
	err |= platform_driver_register (&depca_isa_driver);
	depca_platform_probe ();

        return err;
}

static void __exit depca_module_exit (void)
{
	int i;
#ifdef CONFIG_MCA
        mca_unregister_driver (&depca_mca_driver);
#endif
#ifdef CONFIG_EISA
        eisa_driver_unregister (&depca_eisa_driver);
#endif
	platform_driver_unregister (&depca_isa_driver);

	for (i = 0; depca_io_ports[i].iobase; i++) {
		if (depca_io_ports[i].device) {
			depca_io_ports[i].device->dev.platform_data = NULL;
			platform_device_unregister (depca_io_ports[i].device);
			depca_io_ports[i].device = NULL;
		}
	}
}

module_init (depca_module_init);
module_exit (depca_module_exit);