aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/synclink_gt.c
blob: 03edccc8a82338cac5b5ba6b7b8e7d0b3c115fd2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
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
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
/*
 * $Id: synclink_gt.c,v 4.25 2006/02/06 21:20:33 paulkf Exp $
 *
 * Device driver for Microgate SyncLink GT serial adapters.
 *
 * written by Paul Fulghum for Microgate Corporation
 * paulkf@microgate.com
 *
 * Microgate and SyncLink are trademarks of Microgate Corporation
 *
 * This code is released under the GNU General Public License (GPL)
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * DEBUG OUTPUT DEFINITIONS
 *
 * uncomment lines below to enable specific types of debug output
 *
 * DBGINFO   information - most verbose output
 * DBGERR    serious errors
 * DBGBH     bottom half service routine debugging
 * DBGISR    interrupt service routine debugging
 * DBGDATA   output receive and transmit data
 * DBGTBUF   output transmit DMA buffers and registers
 * DBGRBUF   output receive DMA buffers and registers
 */

#define DBGINFO(fmt) if (debug_level >= DEBUG_LEVEL_INFO) printk fmt
#define DBGERR(fmt) if (debug_level >= DEBUG_LEVEL_ERROR) printk fmt
#define DBGBH(fmt) if (debug_level >= DEBUG_LEVEL_BH) printk fmt
#define DBGISR(fmt) if (debug_level >= DEBUG_LEVEL_ISR) printk fmt
#define DBGDATA(info, buf, size, label) if (debug_level >= DEBUG_LEVEL_DATA) trace_block((info), (buf), (size), (label))
//#define DBGTBUF(info) dump_tbufs(info)
//#define DBGRBUF(info) dump_rbufs(info)


#include <linux/module.h>
#include <linux/version.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ioctl.h>
#include <linux/termios.h>
#include <linux/bitops.h>
#include <linux/workqueue.h>
#include <linux/hdlc.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/types.h>
#include <asm/uaccess.h>

#include "linux/synclink.h"

#ifdef CONFIG_HDLC_MODULE
#define CONFIG_HDLC 1
#endif

/*
 * module identification
 */
static char *driver_name     = "SyncLink GT";
static char *driver_version  = "$Revision: 4.25 $";
static char *tty_driver_name = "synclink_gt";
static char *tty_dev_prefix  = "ttySLG";
MODULE_LICENSE("GPL");
#define MGSL_MAGIC 0x5401
#define MAX_DEVICES 12

static struct pci_device_id pci_table[] = {
	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT2_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT4_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_AC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
	{0,}, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, pci_table);

static int  init_one(struct pci_dev *dev,const struct pci_device_id *ent);
static void remove_one(struct pci_dev *dev);
static struct pci_driver pci_driver = {
	.name		= "synclink_gt",
	.id_table	= pci_table,
	.probe		= init_one,
	.remove		= __devexit_p(remove_one),
};

static int pci_registered;

/*
 * module configuration and status
 */
static struct slgt_info *slgt_device_list;
static int slgt_device_count;

static int ttymajor;
static int debug_level;
static int maxframe[MAX_DEVICES];
static int dosyncppp[MAX_DEVICES];

module_param(ttymajor, int, 0);
module_param(debug_level, int, 0);
module_param_array(maxframe, int, NULL, 0);
module_param_array(dosyncppp, int, NULL, 0);

MODULE_PARM_DESC(ttymajor, "TTY major device number override: 0=auto assigned");
MODULE_PARM_DESC(debug_level, "Debug syslog output: 0=disabled, 1 to 5=increasing detail");
MODULE_PARM_DESC(maxframe, "Maximum frame size used by device (4096 to 65535)");
MODULE_PARM_DESC(dosyncppp, "Enable synchronous net device, 0=disable 1=enable");

/*
 * tty support and callbacks
 */
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

static struct tty_driver *serial_driver;

static int  open(struct tty_struct *tty, struct file * filp);
static void close(struct tty_struct *tty, struct file * filp);
static void hangup(struct tty_struct *tty);
static void set_termios(struct tty_struct *tty, struct termios *old_termios);

static int  write(struct tty_struct *tty, const unsigned char *buf, int count);
static void put_char(struct tty_struct *tty, unsigned char ch);
static void send_xchar(struct tty_struct *tty, char ch);
static void wait_until_sent(struct tty_struct *tty, int timeout);
static int  write_room(struct tty_struct *tty);
static void flush_chars(struct tty_struct *tty);
static void flush_buffer(struct tty_struct *tty);
static void tx_hold(struct tty_struct *tty);
static void tx_release(struct tty_struct *tty);

static int  ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg);
static int  read_proc(char *page, char **start, off_t off, int count,int *eof, void *data);
static int  chars_in_buffer(struct tty_struct *tty);
static void throttle(struct tty_struct * tty);
static void unthrottle(struct tty_struct * tty);
static void set_break(struct tty_struct *tty, int break_state);

/*
 * generic HDLC support and callbacks
 */
#ifdef CONFIG_HDLC
#define dev_to_port(D) (dev_to_hdlc(D)->priv)
static void hdlcdev_tx_done(struct slgt_info *info);
static void hdlcdev_rx(struct slgt_info *info, char *buf, int size);
static int  hdlcdev_init(struct slgt_info *info);
static void hdlcdev_exit(struct slgt_info *info);
#endif


/*
 * device specific structures, macros and functions
 */

#define SLGT_MAX_PORTS 4
#define SLGT_REG_SIZE  256

/*
 * conditional wait facility
 */
struct cond_wait {
	struct cond_wait *next;
	wait_queue_head_t q;
	wait_queue_t wait;
	unsigned int data;
};
static void init_cond_wait(struct cond_wait *w, unsigned int data);
static void add_cond_wait(struct cond_wait **head, struct cond_wait *w);
static void remove_cond_wait(struct cond_wait **head, struct cond_wait *w);
static void flush_cond_wait(struct cond_wait **head);

/*
 * DMA buffer descriptor and access macros
 */
struct slgt_desc
{
	unsigned short count;
	unsigned short status;
	unsigned int pbuf;  /* physical address of data buffer */
	unsigned int next;  /* physical address of next descriptor */

	/* driver book keeping */
	char *buf;          /* virtual  address of data buffer */
    	unsigned int pdesc; /* physical address of this descriptor */
	dma_addr_t buf_dma_addr;
};

#define set_desc_buffer(a,b) (a).pbuf = cpu_to_le32((unsigned int)(b))
#define set_desc_next(a,b) (a).next   = cpu_to_le32((unsigned int)(b))
#define set_desc_count(a,b)(a).count  = cpu_to_le16((unsigned short)(b))
#define set_desc_eof(a,b)  (a).status = cpu_to_le16((b) ? (le16_to_cpu((a).status) | BIT0) : (le16_to_cpu((a).status) & ~BIT0))
#define desc_count(a)      (le16_to_cpu((a).count))
#define desc_status(a)     (le16_to_cpu((a).status))
#define desc_complete(a)   (le16_to_cpu((a).status) & BIT15)
#define desc_eof(a)        (le16_to_cpu((a).status) & BIT2)
#define desc_crc_error(a)  (le16_to_cpu((a).status) & BIT1)
#define desc_abort(a)      (le16_to_cpu((a).status) & BIT0)
#define desc_residue(a)    ((le16_to_cpu((a).status) & 0x38) >> 3)

struct _input_signal_events {
	int ri_up;
	int ri_down;
	int dsr_up;
	int dsr_down;
	int dcd_up;
	int dcd_down;
	int cts_up;
	int cts_down;
};

/*
 * device instance data structure
 */
struct slgt_info {
	void *if_ptr;		/* General purpose pointer (used by SPPP) */

	struct slgt_info *next_device;	/* device list link */

	int magic;
	int flags;

	char device_name[25];
	struct pci_dev *pdev;

	int port_count;  /* count of ports on adapter */
	int adapter_num; /* adapter instance number */
	int port_num;    /* port instance number */

	/* array of pointers to port contexts on this adapter */
	struct slgt_info *port_array[SLGT_MAX_PORTS];

	int			count;		/* count of opens */
	int			line;		/* tty line instance number */
	unsigned short		close_delay;
	unsigned short		closing_wait;	/* time to wait before closing */

	struct mgsl_icount	icount;

	struct tty_struct 	*tty;
	int			timeout;
	int			x_char;		/* xon/xoff character */
	int			blocked_open;	/* # of blocked opens */
	unsigned int		read_status_mask;
	unsigned int 		ignore_status_mask;

	wait_queue_head_t	open_wait;
	wait_queue_head_t	close_wait;

	wait_queue_head_t	status_event_wait_q;
	wait_queue_head_t	event_wait_q;
	struct timer_list	tx_timer;
	struct timer_list	rx_timer;

	unsigned int            gpio_present;
	struct cond_wait        *gpio_wait_q;

	spinlock_t lock;	/* spinlock for synchronizing with ISR */

	struct work_struct task;
	u32 pending_bh;
	int bh_requested;
	int bh_running;

	int isr_overflow;
	int irq_requested;	/* nonzero if IRQ requested */
	int irq_occurred;	/* for diagnostics use */

	/* device configuration */

	unsigned int bus_type;
	unsigned int irq_level;
	unsigned long irq_flags;

	unsigned char __iomem * reg_addr;  /* memory mapped registers address */
	u32 phys_reg_addr;
	int reg_addr_requested;

	MGSL_PARAMS params;       /* communications parameters */
	u32 idle_mode;
	u32 max_frame_size;       /* as set by device config */

	unsigned int raw_rx_size;
	unsigned int if_mode;

	/* device status */

	int rx_enabled;
	int rx_restart;

	int tx_enabled;
	int tx_active;

	unsigned char signals;    /* serial signal states */
	int init_error;  /* initialization error */

	unsigned char *tx_buf;
	int tx_count;

	char flag_buf[MAX_ASYNC_BUFFER_SIZE];
	char char_buf[MAX_ASYNC_BUFFER_SIZE];
	BOOLEAN drop_rts_on_tx_done;
	struct	_input_signal_events	input_signal_events;

	int dcd_chkcount;	/* check counts to prevent */
	int cts_chkcount;	/* too many IRQs if a signal */
	int dsr_chkcount;	/* is floating */
	int ri_chkcount;

	char *bufs;		/* virtual address of DMA buffer lists */
	dma_addr_t bufs_dma_addr; /* physical address of buffer descriptors */

	unsigned int rbuf_count;
	struct slgt_desc *rbufs;
	unsigned int rbuf_current;
	unsigned int rbuf_index;

	unsigned int tbuf_count;
	struct slgt_desc *tbufs;
	unsigned int tbuf_current;
	unsigned int tbuf_start;

	unsigned char *tmp_rbuf;
	unsigned int tmp_rbuf_count;

	/* SPPP/Cisco HDLC device parts */

	int netcount;
	int dosyncppp;
	spinlock_t netlock;
#ifdef CONFIG_HDLC
	struct net_device *netdev;
#endif

};

static MGSL_PARAMS default_params = {
	.mode            = MGSL_MODE_HDLC,
	.loopback        = 0,
	.flags           = HDLC_FLAG_UNDERRUN_ABORT15,
	.encoding        = HDLC_ENCODING_NRZI_SPACE,
	.clock_speed     = 0,
	.addr_filter     = 0xff,
	.crc_type        = HDLC_CRC_16_CCITT,
	.preamble_length = HDLC_PREAMBLE_LENGTH_8BITS,
	.preamble        = HDLC_PREAMBLE_PATTERN_NONE,
	.data_rate       = 9600,
	.data_bits       = 8,
	.stop_bits       = 1,
	.parity          = ASYNC_PARITY_NONE
};


#define BH_RECEIVE  1
#define BH_TRANSMIT 2
#define BH_STATUS   4
#define IO_PIN_SHUTDOWN_LIMIT 100

#define DMABUFSIZE 256
#define DESC_LIST_SIZE 4096

#define MASK_PARITY  BIT1
#define MASK_FRAMING BIT2
#define MASK_BREAK   BIT3
#define MASK_OVERRUN BIT4

#define GSR   0x00 /* global status */
#define JCR   0x04 /* JTAG control */
#define IODR  0x08 /* GPIO direction */
#define IOER  0x0c /* GPIO interrupt enable */
#define IOVR  0x10 /* GPIO value */
#define IOSR  0x14 /* GPIO interrupt status */
#define TDR   0x80 /* tx data */
#define RDR   0x80 /* rx data */
#define TCR   0x82 /* tx control */
#define TIR   0x84 /* tx idle */
#define TPR   0x85 /* tx preamble */
#define RCR   0x86 /* rx control */
#define VCR   0x88 /* V.24 control */
#define CCR   0x89 /* clock control */
#define BDR   0x8a /* baud divisor */
#define SCR   0x8c /* serial control */
#define SSR   0x8e /* serial status */
#define RDCSR 0x90 /* rx DMA control/status */
#define TDCSR 0x94 /* tx DMA control/status */
#define RDDAR 0x98 /* rx DMA descriptor address */
#define TDDAR 0x9c /* tx DMA descriptor address */

#define RXIDLE      BIT14
#define RXBREAK     BIT14
#define IRQ_TXDATA  BIT13
#define IRQ_TXIDLE  BIT12
#define IRQ_TXUNDER BIT11 /* HDLC */
#define IRQ_RXDATA  BIT10
#define IRQ_RXIDLE  BIT9  /* HDLC */
#define IRQ_RXBREAK BIT9  /* async */
#define IRQ_RXOVER  BIT8
#define IRQ_DSR     BIT7
#define IRQ_CTS     BIT6
#define IRQ_DCD     BIT5
#define IRQ_RI      BIT4
#define IRQ_ALL     0x3ff0
#define IRQ_MASTER  BIT0

#define slgt_irq_on(info, mask) \
	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) | (mask)))
#define slgt_irq_off(info, mask) \
	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) & ~(mask)))

static __u8  rd_reg8(struct slgt_info *info, unsigned int addr);
static void  wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value);
static __u16 rd_reg16(struct slgt_info *info, unsigned int addr);
static void  wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value);
static __u32 rd_reg32(struct slgt_info *info, unsigned int addr);
static void  wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value);

static void  msc_set_vcr(struct slgt_info *info);

static int  startup(struct slgt_info *info);
static int  block_til_ready(struct tty_struct *tty, struct file * filp,struct slgt_info *info);
static void shutdown(struct slgt_info *info);
static void program_hw(struct slgt_info *info);
static void change_params(struct slgt_info *info);

static int  register_test(struct slgt_info *info);
static int  irq_test(struct slgt_info *info);
static int  loopback_test(struct slgt_info *info);
static int  adapter_test(struct slgt_info *info);

static void reset_adapter(struct slgt_info *info);
static void reset_port(struct slgt_info *info);
static void async_mode(struct slgt_info *info);
static void hdlc_mode(struct slgt_info *info);

static void rx_stop(struct slgt_info *info);
static void rx_start(struct slgt_info *info);
static void reset_rbufs(struct slgt_info *info);
static void free_rbufs(struct slgt_info *info, unsigned int first, unsigned int last);
static void rdma_reset(struct slgt_info *info);
static int  rx_get_frame(struct slgt_info *info);
static int  rx_get_buf(struct slgt_info *info);

static void tx_start(struct slgt_info *info);
static void tx_stop(struct slgt_info *info);
static void tx_set_idle(struct slgt_info *info);
static unsigned int free_tbuf_count(struct slgt_info *info);
static void reset_tbufs(struct slgt_info *info);
static void tdma_reset(struct slgt_info *info);
static void tx_load(struct slgt_info *info, const char *buf, unsigned int count);

static void get_signals(struct slgt_info *info);
static void set_signals(struct slgt_info *info);
static void enable_loopback(struct slgt_info *info);
static void set_rate(struct slgt_info *info, u32 data_rate);

static int  bh_action(struct slgt_info *info);
static void bh_handler(void* context);
static void bh_transmit(struct slgt_info *info);
static void isr_serial(struct slgt_info *info);
static void isr_rdma(struct slgt_info *info);
static void isr_txeom(struct slgt_info *info, unsigned short status);
static void isr_tdma(struct slgt_info *info);
static irqreturn_t slgt_interrupt(int irq, void *dev_id, struct pt_regs * regs);

static int  alloc_dma_bufs(struct slgt_info *info);
static void free_dma_bufs(struct slgt_info *info);
static int  alloc_desc(struct slgt_info *info);
static void free_desc(struct slgt_info *info);
static int  alloc_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count);
static void free_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count);

static int  alloc_tmp_rbuf(struct slgt_info *info);
static void free_tmp_rbuf(struct slgt_info *info);

static void tx_timeout(unsigned long context);
static void rx_timeout(unsigned long context);

/*
 * ioctl handlers
 */
static int  get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount);
static int  get_params(struct slgt_info *info, MGSL_PARAMS __user *params);
static int  set_params(struct slgt_info *info, MGSL_PARAMS __user *params);
static int  get_txidle(struct slgt_info *info, int __user *idle_mode);
static int  set_txidle(struct slgt_info *info, int idle_mode);
static int  tx_enable(struct slgt_info *info, int enable);
static int  tx_abort(struct slgt_info *info);
static int  rx_enable(struct slgt_info *info, int enable);
static int  modem_input_wait(struct slgt_info *info,int arg);
static int  wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr);
static int  tiocmget(struct tty_struct *tty, struct file *file);
static int  tiocmset(struct tty_struct *tty, struct file *file,
		     unsigned int set, unsigned int clear);
static void set_break(struct tty_struct *tty, int break_state);
static int  get_interface(struct slgt_info *info, int __user *if_mode);
static int  set_interface(struct slgt_info *info, int if_mode);
static int  set_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
static int  get_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
static int  wait_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);

/*
 * driver functions
 */
static void add_device(struct slgt_info *info);
static void device_init(int adapter_num, struct pci_dev *pdev);
static int  claim_resources(struct slgt_info *info);
static void release_resources(struct slgt_info *info);

/*
 * DEBUG OUTPUT CODE
 */
#ifndef DBGINFO
#define DBGINFO(fmt)
#endif
#ifndef DBGERR
#define DBGERR(fmt)
#endif
#ifndef DBGBH
#define DBGBH(fmt)
#endif
#ifndef DBGISR
#define DBGISR(fmt)
#endif

#ifdef DBGDATA
static void trace_block(struct slgt_info *info, const char *data, int count, const char *label)
{
	int i;
	int linecount;
	printk("%s %s data:\n",info->device_name, label);
	while(count) {
		linecount = (count > 16) ? 16 : count;
		for(i=0; i < linecount; i++)
			printk("%02X ",(unsigned char)data[i]);
		for(;i<17;i++)
			printk("   ");
		for(i=0;i<linecount;i++) {
			if (data[i]>=040 && data[i]<=0176)
				printk("%c",data[i]);
			else
				printk(".");
		}
		printk("\n");
		data  += linecount;
		count -= linecount;
	}
}
#else
#define DBGDATA(info, buf, size, label)
#endif

#ifdef DBGTBUF
static void dump_tbufs(struct slgt_info *info)
{
	int i;
	printk("tbuf_current=%d\n", info->tbuf_current);
	for (i=0 ; i < info->tbuf_count ; i++) {
		printk("%d: count=%04X status=%04X\n",
			i, le16_to_cpu(info->tbufs[i].count), le16_to_cpu(info->tbufs[i].status));
	}
}
#else
#define DBGTBUF(info)
#endif

#ifdef DBGRBUF
static void dump_rbufs(struct slgt_info *info)
{
	int i;
	printk("rbuf_current=%d\n", info->rbuf_current);
	for (i=0 ; i < info->rbuf_count ; i++) {
		printk("%d: count=%04X status=%04X\n",
			i, le16_to_cpu(info->rbufs[i].count), le16_to_cpu(info->rbufs[i].status));
	}
}
#else
#define DBGRBUF(info)
#endif

static inline int sanity_check(struct slgt_info *info, char *devname, const char *name)
{
#ifdef SANITY_CHECK
	if (!info) {
		printk("null struct slgt_info for (%s) in %s\n", devname, name);
		return 1;
	}
	if (info->magic != MGSL_MAGIC) {
		printk("bad magic number struct slgt_info (%s) in %s\n", devname, name);
		return 1;
	}
#else
	if (!info)
		return 1;
#endif
	return 0;
}

/**
 * line discipline callback wrappers
 *
 * The wrappers maintain line discipline references
 * while calling into the line discipline.
 *
 * ldisc_receive_buf  - pass receive data to line discipline
 */
static void ldisc_receive_buf(struct tty_struct *tty,
			      const __u8 *data, char *flags, int count)
{
	struct tty_ldisc *ld;
	if (!tty)
		return;
	ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->receive_buf)
			ld->receive_buf(tty, data, flags, count);
		tty_ldisc_deref(ld);
	}
}

/* tty callbacks */

static int open(struct tty_struct *tty, struct file *filp)
{
	struct slgt_info *info;
	int retval, line;
	unsigned long flags;

	line = tty->index;
	if ((line < 0) || (line >= slgt_device_count)) {
		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
		return -ENODEV;
	}

	info = slgt_device_list;
	while(info && info->line != line)
		info = info->next_device;
	if (sanity_check(info, tty->name, "open"))
		return -ENODEV;
	if (info->init_error) {
		DBGERR(("%s init error=%d\n", info->device_name, info->init_error));
		return -ENODEV;
	}

	tty->driver_data = info;
	info->tty = tty;

	DBGINFO(("%s open, old ref count = %d\n", info->device_name, info->count));

	/* If port is closing, signal caller to try again */
	if (tty_hung_up_p(filp) || info->flags & ASYNC_CLOSING){
		if (info->flags & ASYNC_CLOSING)
			interruptible_sleep_on(&info->close_wait);
		retval = ((info->flags & ASYNC_HUP_NOTIFY) ?
			-EAGAIN : -ERESTARTSYS);
		goto cleanup;
	}

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

	spin_lock_irqsave(&info->netlock, flags);
	if (info->netcount) {
		retval = -EBUSY;
		spin_unlock_irqrestore(&info->netlock, flags);
		goto cleanup;
	}
	info->count++;
	spin_unlock_irqrestore(&info->netlock, flags);

	if (info->count == 1) {
		/* 1st open on this device, init hardware */
		retval = startup(info);
		if (retval < 0)
			goto cleanup;
	}

	retval = block_til_ready(tty, filp, info);
	if (retval) {
		DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
		goto cleanup;
	}

	retval = 0;

cleanup:
	if (retval) {
		if (tty->count == 1)
			info->tty = NULL; /* tty layer will release tty struct */
		if(info->count)
			info->count--;
	}

	DBGINFO(("%s open rc=%d\n", info->device_name, retval));
	return retval;
}

static void close(struct tty_struct *tty, struct file *filp)
{
	struct slgt_info *info = tty->driver_data;

	if (sanity_check(info, tty->name, "close"))
		return;
	DBGINFO(("%s close entry, count=%d\n", info->device_name, info->count));

	if (!info->count)
		return;

	if (tty_hung_up_p(filp))
		goto cleanup;

	if ((tty->count == 1) && (info->count != 1)) {
		/*
		 * tty->count is 1 and the tty structure will be freed.
		 * info->count should be one in this case.
		 * if it's not, correct it so that the port is shutdown.
		 */
		DBGERR(("%s close: bad refcount; tty->count=1, "
		       "info->count=%d\n", info->device_name, info->count));
		info->count = 1;
	}

	info->count--;

	/* if at least one open remaining, leave hardware active */
	if (info->count)
		goto cleanup;

	info->flags |= ASYNC_CLOSING;

	/* set tty->closing to notify line discipline to
	 * only process XON/XOFF characters. Only the N_TTY
	 * discipline appears to use this (ppp does not).
	 */
	tty->closing = 1;

	/* wait for transmit data to clear all layers */

	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
		DBGINFO(("%s call tty_wait_until_sent\n", info->device_name));
		tty_wait_until_sent(tty, info->closing_wait);
	}

 	if (info->flags & ASYNC_INITIALIZED)
 		wait_until_sent(tty, info->timeout);
	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);

	shutdown(info);

	tty->closing = 0;
	info->tty = NULL;

	if (info->blocked_open) {
		if (info->close_delay) {
			msleep_interruptible(jiffies_to_msecs(info->close_delay));
		}
		wake_up_interruptible(&info->open_wait);
	}

	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);

	wake_up_interruptible(&info->close_wait);

cleanup:
	DBGINFO(("%s close exit, count=%d\n", tty->driver->name, info->count));
}

static void hangup(struct tty_struct *tty)
{
	struct slgt_info *info = tty->driver_data;

	if (sanity_check(info, tty->name, "hangup"))
		return;
	DBGINFO(("%s hangup\n", info->device_name));

	flush_buffer(tty);
	shutdown(info);

	info->count = 0;
	info->flags &= ~ASYNC_NORMAL_ACTIVE;
	info->tty = NULL;

	wake_up_interruptible(&info->open_wait);
}

static void set_termios(struct tty_struct *tty, struct termios *old_termios)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	DBGINFO(("%s set_termios\n", tty->driver->name));

	/* just return if nothing has changed */
	if ((tty->termios->c_cflag == old_termios->c_cflag)
	    && (RELEVANT_IFLAG(tty->termios->c_iflag)
		== RELEVANT_IFLAG(old_termios->c_iflag)))
		return;

	change_params(info);

	/* Handle transition to B0 status */
	if (old_termios->c_cflag & CBAUD &&
	    !(tty->termios->c_cflag & CBAUD)) {
		info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
		spin_lock_irqsave(&info->lock,flags);
		set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}

	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) &&
	    tty->termios->c_cflag & CBAUD) {
		info->signals |= SerialSignal_DTR;
 		if (!(tty->termios->c_cflag & CRTSCTS) ||
 		    !test_bit(TTY_THROTTLED, &tty->flags)) {
			info->signals |= SerialSignal_RTS;
 		}
		spin_lock_irqsave(&info->lock,flags);
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}

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

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

	if (sanity_check(info, tty->name, "write"))
		goto cleanup;
	DBGINFO(("%s write count=%d\n", info->device_name, count));

	if (!info->tx_buf)
		goto cleanup;

	if (count > info->max_frame_size) {
		ret = -EIO;
		goto cleanup;
	}

	if (!count)
		goto cleanup;

	if (info->params.mode == MGSL_MODE_RAW) {
		unsigned int bufs_needed = (count/DMABUFSIZE);
		unsigned int bufs_free = free_tbuf_count(info);
		if (count % DMABUFSIZE)
			++bufs_needed;
		if (bufs_needed > bufs_free)
			goto cleanup;
	} else {
		if (info->tx_active)
			goto cleanup;
		if (info->tx_count) {
			/* send accumulated data from send_char() calls */
			/* as frame and wait before accepting more data. */
			tx_load(info, info->tx_buf, info->tx_count);
			goto start;
		}
	}

	ret = info->tx_count = count;
	tx_load(info, buf, count);
	goto start;

start:
 	if (info->tx_count && !tty->stopped && !tty->hw_stopped) {
		spin_lock_irqsave(&info->lock,flags);
		if (!info->tx_active)
		 	tx_start(info);
		spin_unlock_irqrestore(&info->lock,flags);
 	}

cleanup:
	DBGINFO(("%s write rc=%d\n", info->device_name, ret));
	return ret;
}

static void put_char(struct tty_struct *tty, unsigned char ch)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "put_char"))
		return;
	DBGINFO(("%s put_char(%d)\n", info->device_name, ch));
	if (!info->tx_buf)
		return;
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active && (info->tx_count < info->max_frame_size))
		info->tx_buf[info->tx_count++] = ch;
	spin_unlock_irqrestore(&info->lock,flags);
}

static void send_xchar(struct tty_struct *tty, char ch)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "send_xchar"))
		return;
	DBGINFO(("%s send_xchar(%d)\n", info->device_name, ch));
	info->x_char = ch;
	if (ch) {
		spin_lock_irqsave(&info->lock,flags);
		if (!info->tx_enabled)
		 	tx_start(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

static void wait_until_sent(struct tty_struct *tty, int timeout)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long orig_jiffies, char_time;

	if (!info )
		return;
	if (sanity_check(info, tty->name, "wait_until_sent"))
		return;
	DBGINFO(("%s wait_until_sent entry\n", info->device_name));
	if (!(info->flags & ASYNC_INITIALIZED))
		goto exit;

	orig_jiffies = jiffies;

	/* Set check interval to 1/5 of estimated time to
	 * send a character, and make it at least 1. The check
	 * interval should also be less than the timeout.
	 * Note: use tight timings here to satisfy the NIST-PCTS.
	 */

	if (info->params.data_rate) {
	       	char_time = info->timeout/(32 * 5);
		if (!char_time)
			char_time++;
	} else
		char_time = 1;

	if (timeout)
		char_time = min_t(unsigned long, char_time, timeout);

	while (info->tx_active) {
		msleep_interruptible(jiffies_to_msecs(char_time));
		if (signal_pending(current))
			break;
		if (timeout && time_after(jiffies, orig_jiffies + timeout))
			break;
	}

exit:
	DBGINFO(("%s wait_until_sent exit\n", info->device_name));
}

static int write_room(struct tty_struct *tty)
{
	struct slgt_info *info = tty->driver_data;
	int ret;

	if (sanity_check(info, tty->name, "write_room"))
		return 0;
	ret = (info->tx_active) ? 0 : HDLC_MAX_FRAME_SIZE;
	DBGINFO(("%s write_room=%d\n", info->device_name, ret));
	return ret;
}

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

	if (sanity_check(info, tty->name, "flush_chars"))
		return;
	DBGINFO(("%s flush_chars entry tx_count=%d\n", info->device_name, info->tx_count));

	if (info->tx_count <= 0 || tty->stopped ||
	    tty->hw_stopped || !info->tx_buf)
		return;

	DBGINFO(("%s flush_chars start transmit\n", info->device_name));

	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active && info->tx_count) {
		tx_load(info, info->tx_buf,info->tx_count);
	 	tx_start(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
}

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

	if (sanity_check(info, tty->name, "flush_buffer"))
		return;
	DBGINFO(("%s flush_buffer\n", info->device_name));

	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active)
		info->tx_count = 0;
	spin_unlock_irqrestore(&info->lock,flags);

	wake_up_interruptible(&tty->write_wait);
	tty_wakeup(tty);
}

/*
 * throttle (stop) transmitter
 */
static void tx_hold(struct tty_struct *tty)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "tx_hold"))
		return;
	DBGINFO(("%s tx_hold\n", info->device_name));
	spin_lock_irqsave(&info->lock,flags);
	if (info->tx_enabled && info->params.mode == MGSL_MODE_ASYNC)
	 	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

/*
 * release (start) transmitter
 */
static void tx_release(struct tty_struct *tty)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "tx_release"))
		return;
	DBGINFO(("%s tx_release\n", info->device_name));
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active && info->tx_count) {
		tx_load(info, info->tx_buf, info->tx_count);
	 	tx_start(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
}

/*
 * Service an IOCTL request
 *
 * Arguments
 *
 * 	tty	pointer to tty instance data
 * 	file	pointer to associated file object for device
 * 	cmd	IOCTL command code
 * 	arg	command argument/context
 *
 * Return 0 if success, otherwise error code
 */
static int ioctl(struct tty_struct *tty, struct file *file,
		 unsigned int cmd, unsigned long arg)
{
	struct slgt_info *info = tty->driver_data;
	struct mgsl_icount cnow;	/* kernel counter temps */
	struct serial_icounter_struct __user *p_cuser;	/* user space */
	unsigned long flags;
	void __user *argp = (void __user *)arg;

	if (sanity_check(info, tty->name, "ioctl"))
		return -ENODEV;
	DBGINFO(("%s ioctl() cmd=%08X\n", info->device_name, cmd));

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}

	switch (cmd) {
	case MGSL_IOCGPARAMS:
		return get_params(info, argp);
	case MGSL_IOCSPARAMS:
		return set_params(info, argp);
	case MGSL_IOCGTXIDLE:
		return get_txidle(info, argp);
	case MGSL_IOCSTXIDLE:
		return set_txidle(info, (int)arg);
	case MGSL_IOCTXENABLE:
		return tx_enable(info, (int)arg);
	case MGSL_IOCRXENABLE:
		return rx_enable(info, (int)arg);
	case MGSL_IOCTXABORT:
		return tx_abort(info);
	case MGSL_IOCGSTATS:
		return get_stats(info, argp);
	case MGSL_IOCWAITEVENT:
		return wait_mgsl_event(info, argp);
	case TIOCMIWAIT:
		return modem_input_wait(info,(int)arg);
	case MGSL_IOCGIF:
		return get_interface(info, argp);
	case MGSL_IOCSIF:
		return set_interface(info,(int)arg);
	case MGSL_IOCSGPIO:
		return set_gpio(info, argp);
	case MGSL_IOCGGPIO:
		return get_gpio(info, argp);
	case MGSL_IOCWAITGPIO:
		return wait_gpio(info, argp);
	case TIOCGICOUNT:
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		spin_unlock_irqrestore(&info->lock,flags);
		p_cuser = argp;
		if (put_user(cnow.cts, &p_cuser->cts) ||
		    put_user(cnow.dsr, &p_cuser->dsr) ||
		    put_user(cnow.rng, &p_cuser->rng) ||
		    put_user(cnow.dcd, &p_cuser->dcd) ||
		    put_user(cnow.rx, &p_cuser->rx) ||
		    put_user(cnow.tx, &p_cuser->tx) ||
		    put_user(cnow.frame, &p_cuser->frame) ||
		    put_user(cnow.overrun, &p_cuser->overrun) ||
		    put_user(cnow.parity, &p_cuser->parity) ||
		    put_user(cnow.brk, &p_cuser->brk) ||
		    put_user(cnow.buf_overrun, &p_cuser->buf_overrun))
			return -EFAULT;
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

/*
 * proc fs support
 */
static inline int line_info(char *buf, struct slgt_info *info)
{
	char stat_buf[30];
	int ret;
	unsigned long flags;

	ret = sprintf(buf, "%s: IO=%08X IRQ=%d MaxFrameSize=%u\n",
		      info->device_name, info->phys_reg_addr,
		      info->irq_level, info->max_frame_size);

	/* output current serial signal states */
	spin_lock_irqsave(&info->lock,flags);
	get_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	stat_buf[0] = 0;
	stat_buf[1] = 0;
	if (info->signals & SerialSignal_RTS)
		strcat(stat_buf, "|RTS");
	if (info->signals & SerialSignal_CTS)
		strcat(stat_buf, "|CTS");
	if (info->signals & SerialSignal_DTR)
		strcat(stat_buf, "|DTR");
	if (info->signals & SerialSignal_DSR)
		strcat(stat_buf, "|DSR");
	if (info->signals & SerialSignal_DCD)
		strcat(stat_buf, "|CD");
	if (info->signals & SerialSignal_RI)
		strcat(stat_buf, "|RI");

	if (info->params.mode != MGSL_MODE_ASYNC) {
		ret += sprintf(buf+ret, "\tHDLC txok:%d rxok:%d",
			       info->icount.txok, info->icount.rxok);
		if (info->icount.txunder)
			ret += sprintf(buf+ret, " txunder:%d", info->icount.txunder);
		if (info->icount.txabort)
			ret += sprintf(buf+ret, " txabort:%d", info->icount.txabort);
		if (info->icount.rxshort)
			ret += sprintf(buf+ret, " rxshort:%d", info->icount.rxshort);
		if (info->icount.rxlong)
			ret += sprintf(buf+ret, " rxlong:%d", info->icount.rxlong);
		if (info->icount.rxover)
			ret += sprintf(buf+ret, " rxover:%d", info->icount.rxover);
		if (info->icount.rxcrc)
			ret += sprintf(buf+ret, " rxcrc:%d", info->icount.rxcrc);
	} else {
		ret += sprintf(buf+ret, "\tASYNC tx:%d rx:%d",
			       info->icount.tx, info->icount.rx);
		if (info->icount.frame)
			ret += sprintf(buf+ret, " fe:%d", info->icount.frame);
		if (info->icount.parity)
			ret += sprintf(buf+ret, " pe:%d", info->icount.parity);
		if (info->icount.brk)
			ret += sprintf(buf+ret, " brk:%d", info->icount.brk);
		if (info->icount.overrun)
			ret += sprintf(buf+ret, " oe:%d", info->icount.overrun);
	}

	/* Append serial signal status to end */
	ret += sprintf(buf+ret, " %s\n", stat_buf+1);

	ret += sprintf(buf+ret, "\ttxactive=%d bh_req=%d bh_run=%d pending_bh=%x\n",
		       info->tx_active,info->bh_requested,info->bh_running,
		       info->pending_bh);

	return ret;
}

/* Called to print information about devices
 */
static int read_proc(char *page, char **start, off_t off, int count,
		     int *eof, void *data)
{
	int len = 0, l;
	off_t	begin = 0;
	struct slgt_info *info;

	len += sprintf(page, "synclink_gt driver:%s\n", driver_version);

	info = slgt_device_list;
	while( info ) {
		l = line_info(page + len, info);
		len += l;
		if (len+begin > off+count)
			goto done;
		if (len+begin < off) {
			begin += len;
			len = 0;
		}
		info = info->next_device;
	}

	*eof = 1;
done:
	if (off >= len+begin)
		return 0;
	*start = page + (off-begin);
	return ((count < begin+len-off) ? count : begin+len-off);
}

/*
 * return count of bytes in transmit buffer
 */
static int chars_in_buffer(struct tty_struct *tty)
{
	struct slgt_info *info = tty->driver_data;
	if (sanity_check(info, tty->name, "chars_in_buffer"))
		return 0;
	DBGINFO(("%s chars_in_buffer()=%d\n", info->device_name, info->tx_count));
	return info->tx_count;
}

/*
 * signal remote device to throttle send data (our receive data)
 */
static void throttle(struct tty_struct * tty)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "throttle"))
		return;
	DBGINFO(("%s throttle\n", info->device_name));
	if (I_IXOFF(tty))
		send_xchar(tty, STOP_CHAR(tty));
 	if (tty->termios->c_cflag & CRTSCTS) {
		spin_lock_irqsave(&info->lock,flags);
		info->signals &= ~SerialSignal_RTS;
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

/*
 * signal remote device to stop throttling send data (our receive data)
 */
static void unthrottle(struct tty_struct * tty)
{
	struct slgt_info *info = tty->driver_data;
	unsigned long flags;

	if (sanity_check(info, tty->name, "unthrottle"))
		return;
	DBGINFO(("%s unthrottle\n", info->device_name));
	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			send_xchar(tty, START_CHAR(tty));
	}
 	if (tty->termios->c_cflag & CRTSCTS) {
		spin_lock_irqsave(&info->lock,flags);
		info->signals |= SerialSignal_RTS;
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

/*
 * set or clear transmit break condition
 * break_state	-1=set break condition, 0=clear
 */
static void set_break(struct tty_struct *tty, int break_state)
{
	struct slgt_info *info = tty->driver_data;
	unsigned short value;
	unsigned long flags;

	if (sanity_check(info, tty->name, "set_break"))
		return;
	DBGINFO(("%s set_break(%d)\n", info->device_name, break_state));

	spin_lock_irqsave(&info->lock,flags);
	value = rd_reg16(info, TCR);
 	if (break_state == -1)
		value |= BIT6;
	else
		value &= ~BIT6;
	wr_reg16(info, TCR, value);
	spin_unlock_irqrestore(&info->lock,flags);
}

#ifdef CONFIG_HDLC

/**
 * called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
 * set encoding and frame check sequence (FCS) options
 *
 * dev       pointer to network device structure
 * encoding  serial encoding setting
 * parity    FCS setting
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
			  unsigned short parity)
{
	struct slgt_info *info = dev_to_port(dev);
	unsigned char  new_encoding;
	unsigned short new_crctype;

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	DBGINFO(("%s hdlcdev_attach\n", info->device_name));

	switch (encoding)
	{
	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
	default: return -EINVAL;
	}

	switch (parity)
	{
	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
	default: return -EINVAL;
	}

	info->params.encoding = new_encoding;
	info->params.crc_type = new_crctype;

	/* if network interface up, reprogram hardware */
	if (info->netcount)
		program_hw(info);

	return 0;
}

/**
 * called by generic HDLC layer to send frame
 *
 * skb  socket buffer containing HDLC frame
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	DBGINFO(("%s hdlc_xmit\n", dev->name));

	/* stop sending until this frame completes */
	netif_stop_queue(dev);

	/* copy data to device buffers */
	info->tx_count = skb->len;
	tx_load(info, skb->data, skb->len);

	/* update network statistics */
	stats->tx_packets++;
	stats->tx_bytes += skb->len;

	/* done with socket buffer, so free it */
	dev_kfree_skb(skb);

	/* save start time for transmit timeout detection */
	dev->trans_start = jiffies;

	/* start hardware transmitter if necessary */
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/**
 * called by network layer when interface enabled
 * claim resources and initialize hardware
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_open(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	int rc;
	unsigned long flags;

	DBGINFO(("%s hdlcdev_open\n", dev->name));

	/* generic HDLC layer open processing */
	if ((rc = hdlc_open(dev)))
		return rc;

	/* arbitrate between network and tty opens */
	spin_lock_irqsave(&info->netlock, flags);
	if (info->count != 0 || info->netcount != 0) {
		DBGINFO(("%s hdlc_open busy\n", dev->name));
		spin_unlock_irqrestore(&info->netlock, flags);
		return -EBUSY;
	}
	info->netcount=1;
	spin_unlock_irqrestore(&info->netlock, flags);

	/* claim resources and init adapter */
	if ((rc = startup(info)) != 0) {
		spin_lock_irqsave(&info->netlock, flags);
		info->netcount=0;
		spin_unlock_irqrestore(&info->netlock, flags);
		return rc;
	}

	/* assert DTR and RTS, apply hardware settings */
	info->signals |= SerialSignal_RTS + SerialSignal_DTR;
	program_hw(info);

	/* enable network layer transmit */
	dev->trans_start = jiffies;
	netif_start_queue(dev);

	/* inform generic HDLC layer of current DCD status */
	spin_lock_irqsave(&info->lock, flags);
	get_signals(info);
	spin_unlock_irqrestore(&info->lock, flags);
	hdlc_set_carrier(info->signals & SerialSignal_DCD, dev);

	return 0;
}

/**
 * called by network layer when interface is disabled
 * shutdown hardware and release resources
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_close(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	unsigned long flags;

	DBGINFO(("%s hdlcdev_close\n", dev->name));

	netif_stop_queue(dev);

	/* shutdown adapter and release resources */
	shutdown(info);

	hdlc_close(dev);

	spin_lock_irqsave(&info->netlock, flags);
	info->netcount=0;
	spin_unlock_irqrestore(&info->netlock, flags);

	return 0;
}

/**
 * called by network layer to process IOCTL call to network device
 *
 * dev  pointer to network device structure
 * ifr  pointer to network interface request structure
 * cmd  IOCTL command code
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings new_line;
	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
	struct slgt_info *info = dev_to_port(dev);
	unsigned int flags;

	DBGINFO(("%s hdlcdev_ioctl\n", dev->name));

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	if (cmd != SIOCWANDEV)
		return hdlc_ioctl(dev, ifr, cmd);

	switch(ifr->ifr_settings.type) {
	case IF_GET_IFACE: /* return current sync_serial_settings */

		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}

		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);

		switch (flags){
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
		default: new_line.clock_type = CLOCK_DEFAULT;
		}

		new_line.clock_rate = info->params.clock_speed;
		new_line.loopback   = info->params.loopback ? 1:0;

		if (copy_to_user(line, &new_line, size))
			return -EFAULT;
		return 0;

	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */

		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (copy_from_user(&new_line, line, size))
			return -EFAULT;

		switch (new_line.clock_type)
		{
		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_DEFAULT:  flags = info->params.flags &
					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
		default: return -EINVAL;
		}

		if (new_line.loopback != 0 && new_line.loopback != 1)
			return -EINVAL;

		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
		info->params.flags |= flags;

		info->params.loopback = new_line.loopback;

		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
			info->params.clock_speed = new_line.clock_rate;
		else
			info->params.clock_speed = 0;

		/* if network interface up, reprogram hardware */
		if (info->netcount)
			program_hw(info);
		return 0;

	default:
		return hdlc_ioctl(dev, ifr, cmd);
	}
}

/**
 * called by network layer when transmit timeout is detected
 *
 * dev  pointer to network device structure
 */
static void hdlcdev_tx_timeout(struct net_device *dev)
{
	struct slgt_info *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	DBGINFO(("%s hdlcdev_tx_timeout\n", dev->name));

	stats->tx_errors++;
	stats->tx_aborted_errors++;

	spin_lock_irqsave(&info->lock,flags);
	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);

	netif_wake_queue(dev);
}

/**
 * called by device driver when transmit completes
 * reenable network layer transmit if stopped
 *
 * info  pointer to device instance information
 */
static void hdlcdev_tx_done(struct slgt_info *info)
{
	if (netif_queue_stopped(info->netdev))
		netif_wake_queue(info->netdev);
}

/**
 * called by device driver when frame received
 * pass frame to network layer
 *
 * info  pointer to device instance information
 * buf   pointer to buffer contianing frame data
 * size  count of data bytes in buf
 */
static void hdlcdev_rx(struct slgt_info *info, char *buf, int size)
{
	struct sk_buff *skb = dev_alloc_skb(size);
	struct net_device *dev = info->netdev;
	struct net_device_stats *stats = hdlc_stats(dev);

	DBGINFO(("%s hdlcdev_rx\n", dev->name));

	if (skb == NULL) {
		DBGERR(("%s: can't alloc skb, drop packet\n", dev->name));
		stats->rx_dropped++;
		return;
	}

	memcpy(skb_put(skb, size),buf,size);

	skb->protocol = hdlc_type_trans(skb, info->netdev);

	stats->rx_packets++;
	stats->rx_bytes += size;

	netif_rx(skb);

	info->netdev->last_rx = jiffies;
}

/**
 * called by device driver when adding device instance
 * do generic HDLC initialization
 *
 * info  pointer to device instance information
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_init(struct slgt_info *info)
{
	int rc;
	struct net_device *dev;
	hdlc_device *hdlc;

	/* allocate and initialize network and HDLC layer objects */

	if (!(dev = alloc_hdlcdev(info))) {
		printk(KERN_ERR "%s hdlc device alloc failure\n", info->device_name);
		return -ENOMEM;
	}

	/* for network layer reporting purposes only */
	dev->mem_start = info->phys_reg_addr;
	dev->mem_end   = info->phys_reg_addr + SLGT_REG_SIZE - 1;
	dev->irq       = info->irq_level;

	/* network layer callbacks and settings */
	dev->do_ioctl       = hdlcdev_ioctl;
	dev->open           = hdlcdev_open;
	dev->stop           = hdlcdev_close;
	dev->tx_timeout     = hdlcdev_tx_timeout;
	dev->watchdog_timeo = 10*HZ;
	dev->tx_queue_len   = 50;

	/* generic HDLC layer callbacks and settings */
	hdlc         = dev_to_hdlc(dev);
	hdlc->attach = hdlcdev_attach;
	hdlc->xmit   = hdlcdev_xmit;

	/* register objects with HDLC layer */
	if ((rc = register_hdlc_device(dev))) {
		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
		free_netdev(dev);
		return rc;
	}

	info->netdev = dev;
	return 0;
}

/**
 * called by device driver when removing device instance
 * do generic HDLC cleanup
 *
 * info  pointer to device instance information
 */
static void hdlcdev_exit(struct slgt_info *info)
{
	unregister_hdlc_device(info->netdev);
	free_netdev(info->netdev);
	info->netdev = NULL;
}

#endif /* ifdef CONFIG_HDLC */

/*
 * get async data from rx DMA buffers
 */
static void rx_async(struct slgt_info *info)
{
 	struct tty_struct *tty = info->tty;
 	struct mgsl_icount *icount = &info->icount;
	unsigned int start, end;
	unsigned char *p;
	unsigned char status;
	struct slgt_desc *bufs = info->rbufs;
	int i, count;
	int chars = 0;
	int stat;
	unsigned char ch;

	start = end = info->rbuf_current;

	while(desc_complete(bufs[end])) {
		count = desc_count(bufs[end]) - info->rbuf_index;
		p     = bufs[end].buf + info->rbuf_index;

		DBGISR(("%s rx_async count=%d\n", info->device_name, count));
		DBGDATA(info, p, count, "rx");

		for(i=0 ; i < count; i+=2, p+=2) {
			ch = *p;
			icount->rx++;

			stat = 0;

			if ((status = *(p+1) & (BIT9 + BIT8))) {
				if (status & BIT9)
					icount->parity++;
				else if (status & BIT8)
					icount->frame++;
				/* discard char if tty control flags say so */
				if (status & info->ignore_status_mask)
					continue;
				if (status & BIT9)
					stat = TTY_PARITY;
				else if (status & BIT8)
					stat = TTY_FRAME;
			}
			if (tty) {
				tty_insert_flip_char(tty, ch, stat);
				chars++;
			}
		}

		if (i < count) {
			/* receive buffer not completed */
			info->rbuf_index += i;
			info->rx_timer.expires = jiffies + 1;
			add_timer(&info->rx_timer);
			break;
		}

		info->rbuf_index = 0;
		free_rbufs(info, end, end);

		if (++end == info->rbuf_count)
			end = 0;

		/* if entire list searched then no frame available */
		if (end == start)
			break;
	}

	if (tty && chars)
		tty_flip_buffer_push(tty);
}

/*
 * return next bottom half action to perform
 */
static int bh_action(struct slgt_info *info)
{
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&info->lock,flags);

	if (info->pending_bh & BH_RECEIVE) {
		info->pending_bh &= ~BH_RECEIVE;
		rc = BH_RECEIVE;
	} else if (info->pending_bh & BH_TRANSMIT) {
		info->pending_bh &= ~BH_TRANSMIT;
		rc = BH_TRANSMIT;
	} else if (info->pending_bh & BH_STATUS) {
		info->pending_bh &= ~BH_STATUS;
		rc = BH_STATUS;
	} else {
		/* Mark BH routine as complete */
		info->bh_running   = 0;
		info->bh_requested = 0;
		rc = 0;
	}

	spin_unlock_irqrestore(&info->lock,flags);

	return rc;
}

/*
 * perform bottom half processing
 */
static void bh_handler(void* context)
{
	struct slgt_info *info = context;
	int action;

	if (!info)
		return;
	info->bh_running = 1;

	while((action = bh_action(info))) {
		switch (action) {
		case BH_RECEIVE:
			DBGBH(("%s bh receive\n", info->device_name));
			switch(info->params.mode) {
			case MGSL_MODE_ASYNC:
				rx_async(info);
				break;
			case MGSL_MODE_HDLC:
				while(rx_get_frame(info));
				break;
			case MGSL_MODE_RAW:
				while(rx_get_buf(info));
				break;
			}
			/* restart receiver if rx DMA buffers exhausted */
			if (info->rx_restart)
				rx_start(info);
			break;
		case BH_TRANSMIT:
			bh_transmit(info);
			break;
		case BH_STATUS:
			DBGBH(("%s bh status\n", info->device_name));
			info->ri_chkcount = 0;
			info->dsr_chkcount = 0;
			info->dcd_chkcount = 0;
			info->cts_chkcount = 0;
			break;
		default:
			DBGBH(("%s unknown action\n", info->device_name));
			break;
		}
	}
	DBGBH(("%s bh_handler exit\n", info->device_name));
}

static void bh_transmit(struct slgt_info *info)
{
	struct tty_struct *tty = info->tty;

	DBGBH(("%s bh_transmit\n", info->device_name));
	if (tty) {
		tty_wakeup(tty);
		wake_up_interruptible(&tty->write_wait);
	}
}

static void dsr_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_DSR);
		return;
	}
	info->icount.dsr++;
	if (info->signals & SerialSignal_DSR)
		info->input_signal_events.dsr_up++;
	else
		info->input_signal_events.dsr_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

static void cts_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_CTS);
		return;
	}
	info->icount.cts++;
	if (info->signals & SerialSignal_CTS)
		info->input_signal_events.cts_up++;
	else
		info->input_signal_events.cts_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;

	if (info->flags & ASYNC_CTS_FLOW) {
		if (info->tty) {
			if (info->tty->hw_stopped) {
				if (info->signals & SerialSignal_CTS) {
		 			info->tty->hw_stopped = 0;
					info->pending_bh |= BH_TRANSMIT;
					return;
				}
			} else {
				if (!(info->signals & SerialSignal_CTS))
		 			info->tty->hw_stopped = 1;
			}
		}
	}
}

static void dcd_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_DCD);
		return;
	}
	info->icount.dcd++;
	if (info->signals & SerialSignal_DCD) {
		info->input_signal_events.dcd_up++;
	} else {
		info->input_signal_events.dcd_down++;
	}
#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlc_set_carrier(info->signals & SerialSignal_DCD, info->netdev);
#endif
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;

	if (info->flags & ASYNC_CHECK_CD) {
		if (info->signals & SerialSignal_DCD)
			wake_up_interruptible(&info->open_wait);
		else {
			if (info->tty)
				tty_hangup(info->tty);
		}
	}
}

static void ri_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_RI);
		return;
	}
	info->icount.dcd++;
	if (info->signals & SerialSignal_RI) {
		info->input_signal_events.ri_up++;
	} else {
		info->input_signal_events.ri_down++;
	}
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

static void isr_serial(struct slgt_info *info)
{
	unsigned short status = rd_reg16(info, SSR);

	DBGISR(("%s isr_serial status=%04X\n", info->device_name, status));

	wr_reg16(info, SSR, status); /* clear pending */

	info->irq_occurred = 1;

	if (info->params.mode == MGSL_MODE_ASYNC) {
		if (status & IRQ_TXIDLE) {
			if (info->tx_count)
				isr_txeom(info, status);
		}
		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
			info->icount.brk++;
			/* process break detection if tty control allows */
			if (info->tty) {
				if (!(status & info->ignore_status_mask)) {
					if (info->read_status_mask & MASK_BREAK) {
						tty_insert_flip_char(info->tty, 0, TTY_BREAK);
						if (info->flags & ASYNC_SAK)
							do_SAK(info->tty);
					}
				}
			}
		}
	} else {
		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
			isr_txeom(info, status);

		if (status & IRQ_RXIDLE) {
			if (status & RXIDLE)
				info->icount.rxidle++;
			else
				info->icount.exithunt++;
			wake_up_interruptible(&info->event_wait_q);
		}

		if (status & IRQ_RXOVER)
			rx_start(info);
	}

	if (status & IRQ_DSR)
		dsr_change(info);
	if (status & IRQ_CTS)
		cts_change(info);
	if (status & IRQ_DCD)
		dcd_change(info);
	if (status & IRQ_RI)
		ri_change(info);
}

static void isr_rdma(struct slgt_info *info)
{
	unsigned int status = rd_reg32(info, RDCSR);

	DBGISR(("%s isr_rdma status=%08x\n", info->device_name, status));

	/* RDCSR (rx DMA control/status)
	 *
	 * 31..07  reserved
	 * 06      save status byte to DMA buffer
	 * 05      error
	 * 04      eol (end of list)
	 * 03      eob (end of buffer)
	 * 02      IRQ enable
	 * 01      reset
	 * 00      enable
	 */
	wr_reg32(info, RDCSR, status);	/* clear pending */

	if (status & (BIT5 + BIT4)) {
		DBGISR(("%s isr_rdma rx_restart=1\n", info->device_name));
		info->rx_restart = 1;
	}
	info->pending_bh |= BH_RECEIVE;
}

static void isr_tdma(struct slgt_info *info)
{
	unsigned int status = rd_reg32(info, TDCSR);

	DBGISR(("%s isr_tdma status=%08x\n", info->device_name, status));

	/* TDCSR (tx DMA control/status)
	 *
	 * 31..06  reserved
	 * 05      error
	 * 04      eol (end of list)
	 * 03      eob (end of buffer)
	 * 02      IRQ enable
	 * 01      reset
	 * 00      enable
	 */
	wr_reg32(info, TDCSR, status);	/* clear pending */

	if (status & (BIT5 + BIT4 + BIT3)) {
		// another transmit buffer has completed
		// run bottom half to get more send data from user
		info->pending_bh |= BH_TRANSMIT;
	}
}

static void isr_txeom(struct slgt_info *info, unsigned short status)
{
	DBGISR(("%s txeom status=%04x\n", info->device_name, status));

	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
	tdma_reset(info);
	reset_tbufs(info);
	if (status & IRQ_TXUNDER) {
		unsigned short val = rd_reg16(info, TCR);
		wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
		wr_reg16(info, TCR, val); /* clear reset bit */
	}

	if (info->tx_active) {
		if (info->params.mode != MGSL_MODE_ASYNC) {
			if (status & IRQ_TXUNDER)
				info->icount.txunder++;
			else if (status & IRQ_TXIDLE)
				info->icount.txok++;
		}

		info->tx_active = 0;
		info->tx_count = 0;

		del_timer(&info->tx_timer);

		if (info->params.mode != MGSL_MODE_ASYNC && info->drop_rts_on_tx_done) {
			info->signals &= ~SerialSignal_RTS;
			info->drop_rts_on_tx_done = 0;
			set_signals(info);
		}

#ifdef CONFIG_HDLC
		if (info->netcount)
			hdlcdev_tx_done(info);
		else
#endif
		{
			if (info->tty && (info->tty->stopped || info->tty->hw_stopped)) {
				tx_stop(info);
				return;
			}
			info->pending_bh |= BH_TRANSMIT;
		}
	}
}

static void isr_gpio(struct slgt_info *info, unsigned int changed, unsigned int state)
{
	struct cond_wait *w, *prev;

	/* wake processes waiting for specific transitions */
	for (w = info->gpio_wait_q, prev = NULL ; w != NULL ; w = w->next) {
		if (w->data & changed) {
			w->data = state;
			wake_up_interruptible(&w->q);
			if (prev != NULL)
				prev->next = w->next;
			else
				info->gpio_wait_q = w->next;
		} else
			prev = w;
	}
}

/* interrupt service routine
 *
 * 	irq	interrupt number
 * 	dev_id	device ID supplied during interrupt registration
 * 	regs	interrupted processor context
 */
static irqreturn_t slgt_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct slgt_info *info;
	unsigned int gsr;
	unsigned int i;

	DBGISR(("slgt_interrupt irq=%d entry\n", irq));

	info = dev_id;
	if (!info)
		return IRQ_NONE;

	spin_lock(&info->lock);

	while((gsr = rd_reg32(info, GSR) & 0xffffff00)) {
		DBGISR(("%s gsr=%08x\n", info->device_name, gsr));
		info->irq_occurred = 1;
		for(i=0; i < info->port_count ; i++) {
			if (info->port_array[i] == NULL)
				continue;
			if (gsr & (BIT8 << i))
				isr_serial(info->port_array[i]);
			if (gsr & (BIT16 << (i*2)))
				isr_rdma(info->port_array[i]);
			if (gsr & (BIT17 << (i*2)))
				isr_tdma(info->port_array[i]);
		}
	}

	if (info->gpio_present) {
		unsigned int state;
		unsigned int changed;
		while ((changed = rd_reg32(info, IOSR)) != 0) {
			DBGISR(("%s iosr=%08x\n", info->device_name, changed));
			/* read latched state of GPIO signals */
			state = rd_reg32(info, IOVR);
			/* clear pending GPIO interrupt bits */
			wr_reg32(info, IOSR, changed);
			for (i=0 ; i < info->port_count ; i++) {
				if (info->port_array[i] != NULL)
					isr_gpio(info->port_array[i], changed, state);
			}
		}
	}

	for(i=0; i < info->port_count ; i++) {
		struct slgt_info *port = info->port_array[i];

		if (port && (port->count || port->netcount) &&
		    port->pending_bh && !port->bh_running &&
		    !port->bh_requested) {
			DBGISR(("%s bh queued\n", port->device_name));
			schedule_work(&port->task);
			port->bh_requested = 1;
		}
	}

	spin_unlock(&info->lock);

	DBGISR(("slgt_interrupt irq=%d exit\n", irq));
	return IRQ_HANDLED;
}

static int startup(struct slgt_info *info)
{
	DBGINFO(("%s startup\n", info->device_name));

	if (info->flags & ASYNC_INITIALIZED)
		return 0;

	if (!info->tx_buf) {
		info->tx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
		if (!info->tx_buf) {
			DBGERR(("%s can't allocate tx buffer\n", info->device_name));
			return -ENOMEM;
		}
	}

	info->pending_bh = 0;

	memset(&info->icount, 0, sizeof(info->icount));

	/* program hardware for current parameters */
	change_params(info);

	if (info->tty)
		clear_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags |= ASYNC_INITIALIZED;

	return 0;
}

/*
 *  called by close() and hangup() to shutdown hardware
 */
static void shutdown(struct slgt_info *info)
{
	unsigned long flags;

	if (!(info->flags & ASYNC_INITIALIZED))
		return;

	DBGINFO(("%s shutdown\n", info->device_name));

	/* clear status wait queue because status changes */
	/* can't happen after shutting down the hardware */
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	del_timer_sync(&info->tx_timer);
	del_timer_sync(&info->rx_timer);

	kfree(info->tx_buf);
	info->tx_buf = NULL;

	spin_lock_irqsave(&info->lock,flags);

	tx_stop(info);
	rx_stop(info);

	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);

 	if (!info->tty || info->tty->termios->c_cflag & HUPCL) {
 		info->signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
		set_signals(info);
	}

	flush_cond_wait(&info->gpio_wait_q);

	spin_unlock_irqrestore(&info->lock,flags);

	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;
}

static void program_hw(struct slgt_info *info)
{
	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);

	rx_stop(info);
	tx_stop(info);

	if (info->params.mode == MGSL_MODE_HDLC ||
	    info->params.mode == MGSL_MODE_RAW ||
	    info->netcount)
		hdlc_mode(info);
	else
		async_mode(info);

	set_signals(info);

	info->dcd_chkcount = 0;
	info->cts_chkcount = 0;
	info->ri_chkcount = 0;
	info->dsr_chkcount = 0;

	slgt_irq_on(info, IRQ_DCD | IRQ_CTS | IRQ_DSR);
	get_signals(info);

	if (info->netcount ||
	    (info->tty && info->tty->termios->c_cflag & CREAD))
		rx_start(info);

	spin_unlock_irqrestore(&info->lock,flags);
}

/*
 * reconfigure adapter based on new parameters
 */
static void change_params(struct slgt_info *info)
{
	unsigned cflag;
	int bits_per_char;

	if (!info->tty || !info->tty->termios)
		return;
	DBGINFO(("%s change_params\n", info->device_name));

	cflag = info->tty->termios->c_cflag;

	/* if B0 rate (hangup) specified then negate DTR and RTS */
	/* otherwise assert DTR and RTS */
 	if (cflag & CBAUD)
		info->signals |= SerialSignal_RTS + SerialSignal_DTR;
	else
		info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);

	/* byte size and parity */

	switch (cflag & CSIZE) {
	case CS5: info->params.data_bits = 5; break;
	case CS6: info->params.data_bits = 6; break;
	case CS7: info->params.data_bits = 7; break;
	case CS8: info->params.data_bits = 8; break;
	default:  info->params.data_bits = 7; break;
	}

	info->params.stop_bits = (cflag & CSTOPB) ? 2 : 1;

	if (cflag & PARENB)
		info->params.parity = (cflag & PARODD) ? ASYNC_PARITY_ODD : ASYNC_PARITY_EVEN;
	else
		info->params.parity = ASYNC_PARITY_NONE;

	/* calculate number of jiffies to transmit a full
	 * FIFO (32 bytes) at specified data rate
	 */
	bits_per_char = info->params.data_bits +
			info->params.stop_bits + 1;

	info->params.data_rate = tty_get_baud_rate(info->tty);

	if (info->params.data_rate) {
		info->timeout = (32*HZ*bits_per_char) /
				info->params.data_rate;
	}
	info->timeout += HZ/50;		/* Add .02 seconds of slop */

	if (cflag & CRTSCTS)
		info->flags |= ASYNC_CTS_FLOW;
	else
		info->flags &= ~ASYNC_CTS_FLOW;

	if (cflag & CLOCAL)
		info->flags &= ~ASYNC_CHECK_CD;
	else
		info->flags |= ASYNC_CHECK_CD;

	/* process tty input control flags */

	info->read_status_mask = IRQ_RXOVER;
	if (I_INPCK(info->tty))
		info->read_status_mask |= MASK_PARITY | MASK_FRAMING;
 	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
 		info->read_status_mask |= MASK_BREAK;
	if (I_IGNPAR(info->tty))
		info->ignore_status_mask |= MASK_PARITY | MASK_FRAMING;
	if (I_IGNBRK(info->tty)) {
		info->ignore_status_mask |= MASK_BREAK;
		/* If ignoring parity and break indicators, ignore
		 * overruns too.  (For real raw support).
		 */
		if (I_IGNPAR(info->tty))
			info->ignore_status_mask |= MASK_OVERRUN;
	}

	program_hw(info);
}

static int get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount)
{
	DBGINFO(("%s get_stats\n",  info->device_name));
	if (!user_icount) {
		memset(&info->icount, 0, sizeof(info->icount));
	} else {
		if (copy_to_user(user_icount, &info->icount, sizeof(struct mgsl_icount)))
			return -EFAULT;
	}
	return 0;
}

static int get_params(struct slgt_info *info, MGSL_PARAMS __user *user_params)
{
	DBGINFO(("%s get_params\n", info->device_name));
	if (copy_to_user(user_params, &info->params, sizeof(MGSL_PARAMS)))
		return -EFAULT;
	return 0;
}

static int set_params(struct slgt_info *info, MGSL_PARAMS __user *new_params)
{
 	unsigned long flags;
	MGSL_PARAMS tmp_params;

	DBGINFO(("%s set_params\n", info->device_name));
	if (copy_from_user(&tmp_params, new_params, sizeof(MGSL_PARAMS)))
		return -EFAULT;

	spin_lock_irqsave(&info->lock, flags);
	memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
	spin_unlock_irqrestore(&info->lock, flags);

 	change_params(info);

	return 0;
}

static int get_txidle(struct slgt_info *info, int __user *idle_mode)
{
	DBGINFO(("%s get_txidle=%d\n", info->device_name, info->idle_mode));
	if (put_user(info->idle_mode, idle_mode))
		return -EFAULT;
	return 0;
}

static int set_txidle(struct slgt_info *info, int idle_mode)
{
 	unsigned long flags;
	DBGINFO(("%s set_txidle(%d)\n", info->device_name, idle_mode));
	spin_lock_irqsave(&info->lock,flags);
	info->idle_mode = idle_mode;
	if (info->params.mode != MGSL_MODE_ASYNC)
		tx_set_idle(info);
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int tx_enable(struct slgt_info *info, int enable)
{
 	unsigned long flags;
	DBGINFO(("%s tx_enable(%d)\n", info->device_name, enable));
	spin_lock_irqsave(&info->lock,flags);
	if (enable) {
		if (!info->tx_enabled)
			tx_start(info);
	} else {
		if (info->tx_enabled)
			tx_stop(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/*
 * abort transmit HDLC frame
 */
static int tx_abort(struct slgt_info *info)
{
 	unsigned long flags;
	DBGINFO(("%s tx_abort\n", info->device_name));
	spin_lock_irqsave(&info->lock,flags);
	tdma_reset(info);
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int rx_enable(struct slgt_info *info, int enable)
{
 	unsigned long flags;
	DBGINFO(("%s rx_enable(%d)\n", info->device_name, enable));
	spin_lock_irqsave(&info->lock,flags);
	if (enable) {
		if (!info->rx_enabled)
			rx_start(info);
	} else {
		if (info->rx_enabled)
			rx_stop(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/*
 *  wait for specified event to occur
 */
static int wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr)
{
 	unsigned long flags;
	int s;
	int rc=0;
	struct mgsl_icount cprev, cnow;
	int events;
	int mask;
	struct	_input_signal_events oldsigs, newsigs;
	DECLARE_WAITQUEUE(wait, current);

	if (get_user(mask, mask_ptr))
		return -EFAULT;

	DBGINFO(("%s wait_mgsl_event(%d)\n", info->device_name, mask));

	spin_lock_irqsave(&info->lock,flags);

	/* return immediately if state matches requested events */
	get_signals(info);
	s = info->signals;

	events = mask &
		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
 		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
	if (events) {
		spin_unlock_irqrestore(&info->lock,flags);
		goto exit;
	}

	/* save current irq counts */
	cprev = info->icount;
	oldsigs = info->input_signal_events;

	/* enable hunt and idle irqs if needed */
	if (mask & (MgslEvent_ExitHuntMode+MgslEvent_IdleReceived)) {
		unsigned short val = rd_reg16(info, SCR);
		if (!(val & IRQ_RXIDLE))
			wr_reg16(info, SCR, (unsigned short)(val | IRQ_RXIDLE));
	}

	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&info->event_wait_q, &wait);

	spin_unlock_irqrestore(&info->lock,flags);

	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}

		/* get current irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		newsigs = info->input_signal_events;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
		    newsigs.dsr_down == oldsigs.dsr_down &&
		    newsigs.dcd_up   == oldsigs.dcd_up   &&
		    newsigs.dcd_down == oldsigs.dcd_down &&
		    newsigs.cts_up   == oldsigs.cts_up   &&
		    newsigs.cts_down == oldsigs.cts_down &&
		    newsigs.ri_up    == oldsigs.ri_up    &&
		    newsigs.ri_down  == oldsigs.ri_down  &&
		    cnow.exithunt    == cprev.exithunt   &&
		    cnow.rxidle      == cprev.rxidle) {
			rc = -EIO;
			break;
		}

		events = mask &
			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
		if (events)
			break;

		cprev = cnow;
		oldsigs = newsigs;
	}

	remove_wait_queue(&info->event_wait_q, &wait);
	set_current_state(TASK_RUNNING);


	if (mask & (MgslEvent_ExitHuntMode + MgslEvent_IdleReceived)) {
		spin_lock_irqsave(&info->lock,flags);
		if (!waitqueue_active(&info->event_wait_q)) {
			/* disable enable exit hunt mode/idle rcvd IRQs */
			wr_reg16(info, SCR,
				(unsigned short)(rd_reg16(info, SCR) & ~IRQ_RXIDLE));
		}
		spin_unlock_irqrestore(&info->lock,flags);
	}
exit:
	if (rc == 0)
		rc = put_user(events, mask_ptr);
	return rc;
}

static int get_interface(struct slgt_info *info, int __user *if_mode)
{
	DBGINFO(("%s get_interface=%x\n", info->device_name, info->if_mode));
	if (put_user(info->if_mode, if_mode))
		return -EFAULT;
	return 0;
}

static int set_interface(struct slgt_info *info, int if_mode)
{
 	unsigned long flags;
	unsigned short val;

	DBGINFO(("%s set_interface=%x)\n", info->device_name, if_mode));
	spin_lock_irqsave(&info->lock,flags);
	info->if_mode = if_mode;

	msc_set_vcr(info);

	/* TCR (tx control) 07  1=RTS driver control */
	val = rd_reg16(info, TCR);
	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
		val |= BIT7;
	else
		val &= ~BIT7;
	wr_reg16(info, TCR, val);

	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/*
 * set general purpose IO pin state and direction
 *
 * user_gpio fields:
 * state   each bit indicates a pin state
 * smask   set bit indicates pin state to set
 * dir     each bit indicates a pin direction (0=input, 1=output)
 * dmask   set bit indicates pin direction to set
 */
static int set_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
{
 	unsigned long flags;
	struct gpio_desc gpio;
	__u32 data;

	if (!info->gpio_present)
		return -EINVAL;
	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
		return -EFAULT;
	DBGINFO(("%s set_gpio state=%08x smask=%08x dir=%08x dmask=%08x\n",
		 info->device_name, gpio.state, gpio.smask,
		 gpio.dir, gpio.dmask));

	spin_lock_irqsave(&info->lock,flags);
	if (gpio.dmask) {
		data = rd_reg32(info, IODR);
		data |= gpio.dmask & gpio.dir;
		data &= ~(gpio.dmask & ~gpio.dir);
		wr_reg32(info, IODR, data);
	}
	if (gpio.smask) {
		data = rd_reg32(info, IOVR);
		data |= gpio.smask & gpio.state;
		data &= ~(gpio.smask & ~gpio.state);
		wr_reg32(info, IOVR, data);
	}
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/*
 * get general purpose IO pin state and direction
 */
static int get_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
{
	struct gpio_desc gpio;
	if (!info->gpio_present)
		return -EINVAL;
	gpio.state = rd_reg32(info, IOVR);
	gpio.smask = 0xffffffff;
	gpio.dir   = rd_reg32(info, IODR);
	gpio.dmask = 0xffffffff;
	if (copy_to_user(user_gpio, &gpio, sizeof(gpio)))
		return -EFAULT;
	DBGINFO(("%s get_gpio state=%08x dir=%08x\n",
		 info->device_name, gpio.state, gpio.dir));
	return 0;
}

/*
 * conditional wait facility
 */
static void init_cond_wait(struct cond_wait *w, unsigned int data)
{
	init_waitqueue_head(&w->q);
	init_waitqueue_entry(&w->wait, current);
	w->data = data;
}

static void add_cond_wait(struct cond_wait **head, struct cond_wait *w)
{
	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&w->q, &w->wait);
	w->next = *head;
	*head = w;
}

static void remove_cond_wait(struct cond_wait **head, struct cond_wait *cw)
{
	struct cond_wait *w, *prev;
	remove_wait_queue(&cw->q, &cw->wait);
	set_current_state(TASK_RUNNING);
	for (w = *head, prev = NULL ; w != NULL ; prev = w, w = w->next) {
		if (w == cw) {
			if (prev != NULL)
				prev->next = w->next;
			else
				*head = w->next;
			break;
		}
	}
}

static void flush_cond_wait(struct cond_wait **head)
{
	while (*head != NULL) {
		wake_up_interruptible(&(*head)->q);
		*head = (*head)->next;
	}
}

/*
 * wait for general purpose I/O pin(s) to enter specified state
 *
 * user_gpio fields:
 * state - bit indicates target pin state
 * smask - set bit indicates watched pin
 *
 * The wait ends when at least one watched pin enters the specified
 * state. When 0 (no error) is returned, user_gpio->state is set to the
 * state of all GPIO pins when the wait ends.
 *
 * Note: Each pin may be a dedicated input, dedicated output, or
 * configurable input/output. The number and configuration of pins
 * varies with the specific adapter model. Only input pins (dedicated
 * or configured) can be monitored with this function.
 */
static int wait_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
{
 	unsigned long flags;
	int rc = 0;
	struct gpio_desc gpio;
	struct cond_wait wait;
	u32 state;

	if (!info->gpio_present)
		return -EINVAL;
	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
		return -EFAULT;
	DBGINFO(("%s wait_gpio() state=%08x smask=%08x\n",
		 info->device_name, gpio.state, gpio.smask));
	/* ignore output pins identified by set IODR bit */
	if ((gpio.smask &= ~rd_reg32(info, IODR)) == 0)
		return -EINVAL;
	init_cond_wait(&wait, gpio.smask);

	spin_lock_irqsave(&info->lock, flags);
	/* enable interrupts for watched pins */
	wr_reg32(info, IOER, rd_reg32(info, IOER) | gpio.smask);
	/* get current pin states */
	state = rd_reg32(info, IOVR);

	if (gpio.smask & ~(state ^ gpio.state)) {
		/* already in target state */
		gpio.state = state;
	} else {
		/* wait for target state */
		add_cond_wait(&info->gpio_wait_q, &wait);
		spin_unlock_irqrestore(&info->lock, flags);
		schedule();
		if (signal_pending(current))
			rc = -ERESTARTSYS;
		else
			gpio.state = wait.data;
		spin_lock_irqsave(&info->lock, flags);
		remove_cond_wait(&info->gpio_wait_q, &wait);
	}

	/* disable all GPIO interrupts if no waiting processes */
	if (info->gpio_wait_q == NULL)
		wr_reg32(info, IOER, 0);
	spin_unlock_irqrestore(&info->lock,flags);

	if ((rc == 0) && copy_to_user(user_gpio, &gpio, sizeof(gpio)))
		rc = -EFAULT;
	return rc;
}

static int modem_input_wait(struct slgt_info *info,int arg)
{
 	unsigned long flags;
	int rc;
	struct mgsl_icount cprev, cnow;
	DECLARE_WAITQUEUE(wait, current);

	/* save current irq counts */
	spin_lock_irqsave(&info->lock,flags);
	cprev = info->icount;
	add_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	spin_unlock_irqrestore(&info->lock,flags);

	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}

		/* get new irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
			rc = -EIO;
			break;
		}

		/* check for change in caller specified modem input */
		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
			rc = 0;
			break;
		}

		cprev = cnow;
	}
	remove_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_RUNNING);
	return rc;
}

/*
 *  return state of serial control and status signals
 */
static int tiocmget(struct tty_struct *tty, struct file *file)
{
	struct slgt_info *info = tty->driver_data;
	unsigned int result;
 	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
 	get_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	result = ((info->signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
		((info->signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
		((info->signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
		((info->signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
		((info->signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
		((info->signals & SerialSignal_CTS) ? TIOCM_CTS:0);

	DBGINFO(("%s tiocmget value=%08X\n", info->device_name, result));
	return result;
}

/*
 * set modem control signals (DTR/RTS)
 *
 * 	cmd	signal command: TIOCMBIS = set bit TIOCMBIC = clear bit
 *		TIOCMSET = set/clear signal values
 * 	value	bit mask for command
 */
static int tiocmset(struct tty_struct *tty, struct file *file,
		    unsigned int set, unsigned int clear)
{
	struct slgt_info *info = tty->driver_data;
 	unsigned long flags;

	DBGINFO(("%s tiocmset(%x,%x)\n", info->device_name, set, clear));

	if (set & TIOCM_RTS)
		info->signals |= SerialSignal_RTS;
	if (set & TIOCM_DTR)
		info->signals |= SerialSignal_DTR;
	if (clear & TIOCM_RTS)
		info->signals &= ~SerialSignal_RTS;
	if (clear & TIOCM_DTR)
		info->signals &= ~SerialSignal_DTR;

	spin_lock_irqsave(&info->lock,flags);
 	set_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/*
 *  block current process until the device is ready to open
 */
static int block_til_ready(struct tty_struct *tty, struct file *filp,
			   struct slgt_info *info)
{
	DECLARE_WAITQUEUE(wait, current);
	int		retval;
	int		do_clocal = 0, extra_count = 0;
	unsigned long	flags;

	DBGINFO(("%s block_til_ready\n", tty->driver->name));

	if (filp->f_flags & O_NONBLOCK || tty->flags & (1 << TTY_IO_ERROR)){
		/* nonblock mode is set or port is not enabled */
		info->flags |= ASYNC_NORMAL_ACTIVE;
		return 0;
	}

	if (tty->termios->c_cflag & CLOCAL)
		do_clocal = 1;

	/* Wait for carrier detect and the line to become
	 * free (i.e., not in use by the callout).  While we are in
	 * this loop, info->count is dropped by one, so that
	 * close() knows when to free things.  We restore it upon
	 * exit, either normal or abnormal.
	 */

	retval = 0;
	add_wait_queue(&info->open_wait, &wait);

	spin_lock_irqsave(&info->lock, flags);
	if (!tty_hung_up_p(filp)) {
		extra_count = 1;
		info->count--;
	}
	spin_unlock_irqrestore(&info->lock, flags);
	info->blocked_open++;

	while (1) {
		if ((tty->termios->c_cflag & CBAUD)) {
			spin_lock_irqsave(&info->lock,flags);
			info->signals |= SerialSignal_RTS + SerialSignal_DTR;
		 	set_signals(info);
			spin_unlock_irqrestore(&info->lock,flags);
		}

		set_current_state(TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp) || !(info->flags & ASYNC_INITIALIZED)){
			retval = (info->flags & ASYNC_HUP_NOTIFY) ?
					-EAGAIN : -ERESTARTSYS;
			break;
		}

		spin_lock_irqsave(&info->lock,flags);
	 	get_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);

 		if (!(info->flags & ASYNC_CLOSING) &&
 		    (do_clocal || (info->signals & SerialSignal_DCD)) ) {
 			break;
		}

		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}

		DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
		schedule();
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&info->open_wait, &wait);

	if (extra_count)
		info->count++;
	info->blocked_open--;

	if (!retval)
		info->flags |= ASYNC_NORMAL_ACTIVE;

	DBGINFO(("%s block_til_ready ready, rc=%d\n", tty->driver->name, retval));
	return retval;
}

static int alloc_tmp_rbuf(struct slgt_info *info)
{
	info->tmp_rbuf = kmalloc(info->max_frame_size + 5, GFP_KERNEL);
	if (info->tmp_rbuf == NULL)
		return -ENOMEM;
	return 0;
}

static void free_tmp_rbuf(struct slgt_info *info)
{
	kfree(info->tmp_rbuf);
	info->tmp_rbuf = NULL;
}

/*
 * allocate DMA descriptor lists.
 */
static int alloc_desc(struct slgt_info *info)
{
	unsigned int i;
	unsigned int pbufs;

	/* allocate memory to hold descriptor lists */
	info->bufs = pci_alloc_consistent(info->pdev, DESC_LIST_SIZE, &info->bufs_dma_addr);
	if (info->bufs == NULL)
		return -ENOMEM;

	memset(info->bufs, 0, DESC_LIST_SIZE);

	info->rbufs = (struct slgt_desc*)info->bufs;
	info->tbufs = ((struct slgt_desc*)info->bufs) + info->rbuf_count;

	pbufs = (unsigned int)info->bufs_dma_addr;

	/*
	 * Build circular lists of descriptors
	 */

	for (i=0; i < info->rbuf_count; i++) {
		/* physical address of this descriptor */
		info->rbufs[i].pdesc = pbufs + (i * sizeof(struct slgt_desc));

		/* physical address of next descriptor */
		if (i == info->rbuf_count - 1)
			info->rbufs[i].next = cpu_to_le32(pbufs);
		else
			info->rbufs[i].next = cpu_to_le32(pbufs + ((i+1) * sizeof(struct slgt_desc)));
		set_desc_count(info->rbufs[i], DMABUFSIZE);
	}

	for (i=0; i < info->tbuf_count; i++) {
		/* physical address of this descriptor */
		info->tbufs[i].pdesc = pbufs + ((info->rbuf_count + i) * sizeof(struct slgt_desc));

		/* physical address of next descriptor */
		if (i == info->tbuf_count - 1)
			info->tbufs[i].next = cpu_to_le32(pbufs + info->rbuf_count * sizeof(struct slgt_desc));
		else
			info->tbufs[i].next = cpu_to_le32(pbufs + ((info->rbuf_count + i + 1) * sizeof(struct slgt_desc)));
	}

	return 0;
}

static void free_desc(struct slgt_info *info)
{
	if (info->bufs != NULL) {
		pci_free_consistent(info->pdev, DESC_LIST_SIZE, info->bufs, info->bufs_dma_addr);
		info->bufs  = NULL;
		info->rbufs = NULL;
		info->tbufs = NULL;
	}
}

static int alloc_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
{
	int i;
	for (i=0; i < count; i++) {
		if ((bufs[i].buf = pci_alloc_consistent(info->pdev, DMABUFSIZE, &bufs[i].buf_dma_addr)) == NULL)
			return -ENOMEM;
		bufs[i].pbuf  = cpu_to_le32((unsigned int)bufs[i].buf_dma_addr);
	}
	return 0;
}

static void free_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
{
	int i;
	for (i=0; i < count; i++) {
		if (bufs[i].buf == NULL)
			continue;
		pci_free_consistent(info->pdev, DMABUFSIZE, bufs[i].buf, bufs[i].buf_dma_addr);
		bufs[i].buf = NULL;
	}
}

static int alloc_dma_bufs(struct slgt_info *info)
{
	info->rbuf_count = 32;
	info->tbuf_count = 32;

	if (alloc_desc(info) < 0 ||
	    alloc_bufs(info, info->rbufs, info->rbuf_count) < 0 ||
	    alloc_bufs(info, info->tbufs, info->tbuf_count) < 0 ||
	    alloc_tmp_rbuf(info) < 0) {
		DBGERR(("%s DMA buffer alloc fail\n", info->device_name));
		return -ENOMEM;
	}
	reset_rbufs(info);
	return 0;
}

static void free_dma_bufs(struct slgt_info *info)
{
	if (info->bufs) {
		free_bufs(info, info->rbufs, info->rbuf_count);
		free_bufs(info, info->tbufs, info->tbuf_count);
		free_desc(info);
	}
	free_tmp_rbuf(info);
}

static int claim_resources(struct slgt_info *info)
{
	if (request_mem_region(info->phys_reg_addr, SLGT_REG_SIZE, "synclink_gt") == NULL) {
		DBGERR(("%s reg addr conflict, addr=%08X\n",
			info->device_name, info->phys_reg_addr));
		info->init_error = DiagStatus_AddressConflict;
		goto errout;
	}
	else
		info->reg_addr_requested = 1;

	info->reg_addr = ioremap(info->phys_reg_addr, SLGT_REG_SIZE);
	if (!info->reg_addr) {
		DBGERR(("%s cant map device registers, addr=%08X\n",
			info->device_name, info->phys_reg_addr));
		info->init_error = DiagStatus_CantAssignPciResources;
		goto errout;
	}
	return 0;

errout:
	release_resources(info);
	return -ENODEV;
}

static void release_resources(struct slgt_info *info)
{
	if (info->irq_requested) {
		free_irq(info->irq_level, info);
		info->irq_requested = 0;
	}

	if (info->reg_addr_requested) {
		release_mem_region(info->phys_reg_addr, SLGT_REG_SIZE);
		info->reg_addr_requested = 0;
	}

	if (info->reg_addr) {
		iounmap(info->reg_addr);
		info->reg_addr = NULL;
	}
}

/* Add the specified device instance data structure to the
 * global linked list of devices and increment the device count.
 */
static void add_device(struct slgt_info *info)
{
	char *devstr;

	info->next_device = NULL;
	info->line = slgt_device_count;
	sprintf(info->device_name, "%s%d", tty_dev_prefix, info->line);

	if (info->line < MAX_DEVICES) {
		if (maxframe[info->line])
			info->max_frame_size = maxframe[info->line];
		info->dosyncppp = dosyncppp[info->line];
	}

	slgt_device_count++;

	if (!slgt_device_list)
		slgt_device_list = info;
	else {
		struct slgt_info *current_dev = slgt_device_list;
		while(current_dev->next_device)
			current_dev = current_dev->next_device;
		current_dev->next_device = info;
	}

	if (info->max_frame_size < 4096)
		info->max_frame_size = 4096;
	else if (info->max_frame_size > 65535)
		info->max_frame_size = 65535;

	switch(info->pdev->device) {
	case SYNCLINK_GT_DEVICE_ID:
		devstr = "GT";
		break;
	case SYNCLINK_GT2_DEVICE_ID:
		devstr = "GT2";
		break;
	case SYNCLINK_GT4_DEVICE_ID:
		devstr = "GT4";
		break;
	case SYNCLINK_AC_DEVICE_ID:
		devstr = "AC";
		info->params.mode = MGSL_MODE_ASYNC;
		break;
	default:
		devstr = "(unknown model)";
	}
	printk("SyncLink %s %s IO=%08x IRQ=%d MaxFrameSize=%u\n",
		devstr, info->device_name, info->phys_reg_addr,
		info->irq_level, info->max_frame_size);

#ifdef CONFIG_HDLC
	hdlcdev_init(info);
#endif
}

/*
 *  allocate device instance structure, return NULL on failure
 */
static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev *pdev)
{
	struct slgt_info *info;

	info = kmalloc(sizeof(struct slgt_info), GFP_KERNEL);

	if (!info) {
		DBGERR(("%s device alloc failed adapter=%d port=%d\n",
			driver_name, adapter_num, port_num));
	} else {
		memset(info, 0, sizeof(struct slgt_info));
		info->magic = MGSL_MAGIC;
		INIT_WORK(&info->task, bh_handler, info);
		info->max_frame_size = 4096;
		info->raw_rx_size = DMABUFSIZE;
		info->close_delay = 5*HZ/10;
		info->closing_wait = 30*HZ;
		init_waitqueue_head(&info->open_wait);
		init_waitqueue_head(&info->close_wait);
		init_waitqueue_head(&info->status_event_wait_q);
		init_waitqueue_head(&info->event_wait_q);
		spin_lock_init(&info->netlock);
		memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
		info->idle_mode = HDLC_TXIDLE_FLAGS;
		info->adapter_num = adapter_num;
		info->port_num = port_num;

		init_timer(&info->tx_timer);
		info->tx_timer.data = (unsigned long)info;
		info->tx_timer.function = tx_timeout;

		init_timer(&info->rx_timer);
		info->rx_timer.data = (unsigned long)info;
		info->rx_timer.function = rx_timeout;

		/* Copy configuration info to device instance data */
		info->pdev = pdev;
		info->irq_level = pdev->irq;
		info->phys_reg_addr = pci_resource_start(pdev,0);

		info->bus_type = MGSL_BUS_TYPE_PCI;
		info->irq_flags = SA_SHIRQ;

		info->init_error = -1; /* assume error, set to 0 on successful init */
	}

	return info;
}

static void device_init(int adapter_num, struct pci_dev *pdev)
{
	struct slgt_info *port_array[SLGT_MAX_PORTS];
	int i;
	int port_count = 1;

	if (pdev->device == SYNCLINK_GT2_DEVICE_ID)
		port_count = 2;
	else if (pdev->device == SYNCLINK_GT4_DEVICE_ID)
		port_count = 4;

	/* allocate device instances for all ports */
	for (i=0; i < port_count; ++i) {
		port_array[i] = alloc_dev(adapter_num, i, pdev);
		if (port_array[i] == NULL) {
			for (--i; i >= 0; --i)
				kfree(port_array[i]);
			return;
		}
	}

	/* give copy of port_array to all ports and add to device list  */
	for (i=0; i < port_count; ++i) {
		memcpy(port_array[i]->port_array, port_array, sizeof(port_array));
		add_device(port_array[i]);
		port_array[i]->port_count = port_count;
		spin_lock_init(&port_array[i]->lock);
	}

	/* Allocate and claim adapter resources */
	if (!claim_resources(port_array[0])) {

		alloc_dma_bufs(port_array[0]);

		/* copy resource information from first port to others */
		for (i = 1; i < port_count; ++i) {
			port_array[i]->lock      = port_array[0]->lock;
			port_array[i]->irq_level = port_array[0]->irq_level;
			port_array[i]->reg_addr  = port_array[0]->reg_addr;
			alloc_dma_bufs(port_array[i]);
		}

		if (request_irq(port_array[0]->irq_level,
					slgt_interrupt,
					port_array[0]->irq_flags,
					port_array[0]->device_name,
					port_array[0]) < 0) {
			DBGERR(("%s request_irq failed IRQ=%d\n",
				port_array[0]->device_name,
				port_array[0]->irq_level));
		} else {
			port_array[0]->irq_requested = 1;
			adapter_test(port_array[0]);
			for (i=1 ; i < port_count ; i++) {
				port_array[i]->init_error = port_array[0]->init_error;
				port_array[i]->gpio_present = port_array[0]->gpio_present;
			}
		}
	}
}

static int __devinit init_one(struct pci_dev *dev,
			      const struct pci_device_id *ent)
{
	if (pci_enable_device(dev)) {
		printk("error enabling pci device %p\n", dev);
		return -EIO;
	}
	pci_set_master(dev);
	device_init(slgt_device_count, dev);
	return 0;
}

static void __devexit remove_one(struct pci_dev *dev)
{
}

static struct tty_operations ops = {
	.open = open,
	.close = close,
	.write = write,
	.put_char = put_char,
	.flush_chars = flush_chars,
	.write_room = write_room,
	.chars_in_buffer = chars_in_buffer,
	.flush_buffer = flush_buffer,
	.ioctl = ioctl,
	.throttle = throttle,
	.unthrottle = unthrottle,
	.send_xchar = send_xchar,
	.break_ctl = set_break,
	.wait_until_sent = wait_until_sent,
 	.read_proc = read_proc,
	.set_termios = set_termios,
	.stop = tx_hold,
	.start = tx_release,
	.hangup = hangup,
	.tiocmget = tiocmget,
	.tiocmset = tiocmset,
};

static void slgt_cleanup(void)
{
	int rc;
	struct slgt_info *info;
	struct slgt_info *tmp;

	printk("unload %s %s\n", driver_name, driver_version);

	if (serial_driver) {
		if ((rc = tty_unregister_driver(serial_driver)))
			DBGERR(("tty_unregister_driver error=%d\n", rc));
		put_tty_driver(serial_driver);
	}

	/* reset devices */
	info = slgt_device_list;
	while(info) {
		reset_port(info);
		info = info->next_device;
	}

	/* release devices */
	info = slgt_device_list;
	while(info) {
#ifdef CONFIG_HDLC
		hdlcdev_exit(info);
#endif
		free_dma_bufs(info);
		free_tmp_rbuf(info);
		if (info->port_num == 0)
			release_resources(info);
		tmp = info;
		info = info->next_device;
		kfree(tmp);
	}

	if (pci_registered)
		pci_unregister_driver(&pci_driver);
}

/*
 *  Driver initialization entry point.
 */
static int __init slgt_init(void)
{
	int rc;

 	printk("%s %s\n", driver_name, driver_version);

	slgt_device_count = 0;
	if ((rc = pci_register_driver(&pci_driver)) < 0) {
		printk("%s pci_register_driver error=%d\n", driver_name, rc);
		return rc;
	}
	pci_registered = 1;

	if (!slgt_device_list) {
		printk("%s no devices found\n",driver_name);
		return -ENODEV;
	}

	serial_driver = alloc_tty_driver(MAX_DEVICES);
	if (!serial_driver) {
		rc = -ENOMEM;
		goto error;
	}

	/* Initialize the tty_driver structure */

	serial_driver->owner = THIS_MODULE;
	serial_driver->driver_name = tty_driver_name;
	serial_driver->name = tty_dev_prefix;
	serial_driver->major = ttymajor;
	serial_driver->minor_start = 64;
	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	serial_driver->subtype = SERIAL_TYPE_NORMAL;
	serial_driver->init_termios = tty_std_termios;
	serial_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	serial_driver->flags = TTY_DRIVER_REAL_RAW;
	tty_set_operations(serial_driver, &ops);
	if ((rc = tty_register_driver(serial_driver)) < 0) {
		DBGERR(("%s can't register serial driver\n", driver_name));
		put_tty_driver(serial_driver);
		serial_driver = NULL;
		goto error;
	}

 	printk("%s %s, tty major#%d\n",
		driver_name, driver_version,
		serial_driver->major);

	return 0;

error:
	slgt_cleanup();
	return rc;
}

static void __exit slgt_exit(void)
{
	slgt_cleanup();
}

module_init(slgt_init);
module_exit(slgt_exit);

/*
 * register access routines
 */

#define CALC_REGADDR() \
	unsigned long reg_addr = ((unsigned long)info->reg_addr) + addr; \
	if (addr >= 0x80) \
		reg_addr += (info->port_num) * 32;

static __u8 rd_reg8(struct slgt_info *info, unsigned int addr)
{
	CALC_REGADDR();
	return readb((void __iomem *)reg_addr);
}

static void wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value)
{
	CALC_REGADDR();
	writeb(value, (void __iomem *)reg_addr);
}

static __u16 rd_reg16(struct slgt_info *info, unsigned int addr)
{
	CALC_REGADDR();
	return readw((void __iomem *)reg_addr);
}

static void wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value)
{
	CALC_REGADDR();
	writew(value, (void __iomem *)reg_addr);
}

static __u32 rd_reg32(struct slgt_info *info, unsigned int addr)
{
	CALC_REGADDR();
	return readl((void __iomem *)reg_addr);
}

static void wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value)
{
	CALC_REGADDR();
	writel(value, (void __iomem *)reg_addr);
}

static void rdma_reset(struct slgt_info *info)
{
	unsigned int i;

	/* set reset bit */
	wr_reg32(info, RDCSR, BIT1);

	/* wait for enable bit cleared */
	for(i=0 ; i < 1000 ; i++)
		if (!(rd_reg32(info, RDCSR) & BIT0))
			break;
}

static void tdma_reset(struct slgt_info *info)
{
	unsigned int i;

	/* set reset bit */
	wr_reg32(info, TDCSR, BIT1);

	/* wait for enable bit cleared */
	for(i=0 ; i < 1000 ; i++)
		if (!(rd_reg32(info, TDCSR) & BIT0))
			break;
}

/*
 * enable internal loopback
 * TxCLK and RxCLK are generated from BRG
 * and TxD is looped back to RxD internally.
 */
static void enable_loopback(struct slgt_info *info)
{
	/* SCR (serial control) BIT2=looopback enable */
	wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT2));

	if (info->params.mode != MGSL_MODE_ASYNC) {
		/* CCR (clock control)
		 * 07..05  tx clock source (010 = BRG)
		 * 04..02  rx clock source (010 = BRG)
		 * 01      auxclk enable   (0 = disable)
		 * 00      BRG enable      (1 = enable)
		 *
		 * 0100 1001
		 */
		wr_reg8(info, CCR, 0x49);

		/* set speed if available, otherwise use default */
		if (info->params.clock_speed)
			set_rate(info, info->params.clock_speed);
		else
			set_rate(info, 3686400);
	}
}

/*
 *  set baud rate generator to specified rate
 */
static void set_rate(struct slgt_info *info, u32 rate)
{
	unsigned int div;
	static unsigned int osc = 14745600;

	/* div = osc/rate - 1
	 *
	 * Round div up if osc/rate is not integer to
	 * force to next slowest rate.
	 */

	if (rate) {
		div = osc/rate;
		if (!(osc % rate) && div)
			div--;
		wr_reg16(info, BDR, (unsigned short)div);
	}
}

static void rx_stop(struct slgt_info *info)
{
	unsigned short val;

	/* disable and reset receiver */
	val = rd_reg16(info, RCR) & ~BIT1;          /* clear enable bit */
	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
	wr_reg16(info, RCR, val);                  /* clear reset bit */

	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA + IRQ_RXIDLE);

	/* clear pending rx interrupts */
	wr_reg16(info, SSR, IRQ_RXIDLE + IRQ_RXOVER);

	rdma_reset(info);

	info->rx_enabled = 0;
	info->rx_restart = 0;
}

static void rx_start(struct slgt_info *info)
{
	unsigned short val;

	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA);

	/* clear pending rx overrun IRQ */
	wr_reg16(info, SSR, IRQ_RXOVER);

	/* reset and disable receiver */
	val = rd_reg16(info, RCR) & ~BIT1; /* clear enable bit */
	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
	wr_reg16(info, RCR, val);                  /* clear reset bit */

	rdma_reset(info);
	reset_rbufs(info);

	/* set 1st descriptor address */
	wr_reg32(info, RDDAR, info->rbufs[0].pdesc);

	if (info->params.mode != MGSL_MODE_ASYNC) {
		/* enable rx DMA and DMA interrupt */
		wr_reg32(info, RDCSR, (BIT2 + BIT0));
	} else {
		/* enable saving of rx status, rx DMA and DMA interrupt */
		wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
	}

	slgt_irq_on(info, IRQ_RXOVER);

	/* enable receiver */
	wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | BIT1));

	info->rx_restart = 0;
	info->rx_enabled = 1;
}

static void tx_start(struct slgt_info *info)
{
	if (!info->tx_enabled) {
		wr_reg16(info, TCR,
			(unsigned short)(rd_reg16(info, TCR) | BIT1));
		info->tx_enabled = TRUE;
	}

	if (info->tx_count) {
		info->drop_rts_on_tx_done = 0;

		if (info->params.mode != MGSL_MODE_ASYNC) {
			if (info->params.flags & HDLC_FLAG_AUTO_RTS) {
				get_signals(info);
				if (!(info->signals & SerialSignal_RTS)) {
					info->signals |= SerialSignal_RTS;
					set_signals(info);
					info->drop_rts_on_tx_done = 1;
				}
			}

			slgt_irq_off(info, IRQ_TXDATA);
			slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE);
			/* clear tx idle and underrun status bits */
			wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));

			if (!(rd_reg32(info, TDCSR) & BIT0)) {
				/* tx DMA stopped, restart tx DMA */
				tdma_reset(info);
				/* set 1st descriptor address */
				wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
				if (info->params.mode == MGSL_MODE_RAW)
					wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */
				else
					wr_reg32(info, TDCSR, BIT0); /* DMA enable */
			}

			if (info->params.mode != MGSL_MODE_RAW) {
				info->tx_timer.expires = jiffies + msecs_to_jiffies(5000);
				add_timer(&info->tx_timer);
			}
		} else {
			tdma_reset(info);
			/* set 1st descriptor address */
			wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);

			slgt_irq_off(info, IRQ_TXDATA);
			slgt_irq_on(info, IRQ_TXIDLE);
			/* clear tx idle status bit */
			wr_reg16(info, SSR, IRQ_TXIDLE);

			/* enable tx DMA */
			wr_reg32(info, TDCSR, BIT0);
		}

		info->tx_active = 1;
	}
}

static void tx_stop(struct slgt_info *info)
{
	unsigned short val;

	del_timer(&info->tx_timer);

	tdma_reset(info);

	/* reset and disable transmitter */
	val = rd_reg16(info, TCR) & ~BIT1;          /* clear enable bit */
	wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
	wr_reg16(info, TCR, val);                  /* clear reset */

	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);

	/* clear tx idle and underrun status bit */
	wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));

	reset_tbufs(info);

	info->tx_enabled = 0;
	info->tx_active  = 0;
}

static void reset_port(struct slgt_info *info)
{
	if (!info->reg_addr)
		return;

	tx_stop(info);
	rx_stop(info);

	info->signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
	set_signals(info);

	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
}

static void reset_adapter(struct slgt_info *info)
{
	int i;
	for (i=0; i < info->port_count; ++i) {
		if (info->port_array[i])
			reset_port(info->port_array[i]);
	}
}

static void async_mode(struct slgt_info *info)
{
  	unsigned short val;

	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
	tx_stop(info);
	rx_stop(info);

	/* TCR (tx control)
	 *
	 * 15..13  mode, 010=async
	 * 12..10  encoding, 000=NRZ
	 * 09      parity enable
	 * 08      1=odd parity, 0=even parity
	 * 07      1=RTS driver control
	 * 06      1=break enable
	 * 05..04  character length
	 *         00=5 bits
	 *         01=6 bits
	 *         10=7 bits
	 *         11=8 bits
	 * 03      0=1 stop bit, 1=2 stop bits
	 * 02      reset
	 * 01      enable
	 * 00      auto-CTS enable
	 */
	val = 0x4000;

	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
		val |= BIT7;

	if (info->params.parity != ASYNC_PARITY_NONE) {
		val |= BIT9;
		if (info->params.parity == ASYNC_PARITY_ODD)
			val |= BIT8;
	}

	switch (info->params.data_bits)
	{
	case 6: val |= BIT4; break;
	case 7: val |= BIT5; break;
	case 8: val |= BIT5 + BIT4; break;
	}

	if (info->params.stop_bits != 1)
		val |= BIT3;

	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
		val |= BIT0;

	wr_reg16(info, TCR, val);

	/* RCR (rx control)
	 *
	 * 15..13  mode, 010=async
	 * 12..10  encoding, 000=NRZ
	 * 09      parity enable
	 * 08      1=odd parity, 0=even parity
	 * 07..06  reserved, must be 0
	 * 05..04  character length
	 *         00=5 bits
	 *         01=6 bits
	 *         10=7 bits
	 *         11=8 bits
	 * 03      reserved, must be zero
	 * 02      reset
	 * 01      enable
	 * 00      auto-DCD enable
	 */
	val = 0x4000;

	if (info->params.parity != ASYNC_PARITY_NONE) {
		val |= BIT9;
		if (info->params.parity == ASYNC_PARITY_ODD)
			val |= BIT8;
	}

	switch (info->params.data_bits)
	{
	case 6: val |= BIT4; break;
	case 7: val |= BIT5; break;
	case 8: val |= BIT5 + BIT4; break;
	}

	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
		val |= BIT0;

	wr_reg16(info, RCR, val);

	/* CCR (clock control)
	 *
	 * 07..05  011 = tx clock source is BRG/16
	 * 04..02  010 = rx clock source is BRG
	 * 01      0 = auxclk disabled
	 * 00      1 = BRG enabled
	 *
	 * 0110 1001
	 */
	wr_reg8(info, CCR, 0x69);

	msc_set_vcr(info);

	/* SCR (serial control)
	 *
	 * 15  1=tx req on FIFO half empty
	 * 14  1=rx req on FIFO half full
	 * 13  tx data  IRQ enable
	 * 12  tx idle  IRQ enable
	 * 11  rx break on IRQ enable
	 * 10  rx data  IRQ enable
	 * 09  rx break off IRQ enable
	 * 08  overrun  IRQ enable
	 * 07  DSR      IRQ enable
	 * 06  CTS      IRQ enable
	 * 05  DCD      IRQ enable
	 * 04  RI       IRQ enable
	 * 03  reserved, must be zero
	 * 02  1=txd->rxd internal loopback enable
	 * 01  reserved, must be zero
	 * 00  1=master IRQ enable
	 */
	val = BIT15 + BIT14 + BIT0;
	wr_reg16(info, SCR, val);

	slgt_irq_on(info, IRQ_RXBREAK | IRQ_RXOVER);

	set_rate(info, info->params.data_rate * 16);

	if (info->params.loopback)
		enable_loopback(info);
}

static void hdlc_mode(struct slgt_info *info)
{
	unsigned short val;

	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
	tx_stop(info);
	rx_stop(info);

	/* TCR (tx control)
	 *
	 * 15..13  mode, 000=HDLC 001=raw sync
	 * 12..10  encoding
	 * 09      CRC enable
	 * 08      CRC32
	 * 07      1=RTS driver control
	 * 06      preamble enable
	 * 05..04  preamble length
	 * 03      share open/close flag
	 * 02      reset
	 * 01      enable
	 * 00      auto-CTS enable
	 */
	val = 0;

	if (info->params.mode == MGSL_MODE_RAW)
		val |= BIT13;
	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
		val |= BIT7;

	switch(info->params.encoding)
	{
	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
	}

	switch (info->params.crc_type & HDLC_CRC_MASK)
	{
	case HDLC_CRC_16_CCITT: val |= BIT9; break;
	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
	}

	if (info->params.preamble != HDLC_PREAMBLE_PATTERN_NONE)
		val |= BIT6;

	switch (info->params.preamble_length)
	{
	case HDLC_PREAMBLE_LENGTH_16BITS: val |= BIT5; break;
	case HDLC_PREAMBLE_LENGTH_32BITS: val |= BIT4; break;
	case HDLC_PREAMBLE_LENGTH_64BITS: val |= BIT5 + BIT4; break;
	}

	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
		val |= BIT0;

	wr_reg16(info, TCR, val);

	/* TPR (transmit preamble) */

	switch (info->params.preamble)
	{
	case HDLC_PREAMBLE_PATTERN_FLAGS: val = 0x7e; break;
	case HDLC_PREAMBLE_PATTERN_ONES:  val = 0xff; break;
	case HDLC_PREAMBLE_PATTERN_ZEROS: val = 0x00; break;
	case HDLC_PREAMBLE_PATTERN_10:    val = 0x55; break;
	case HDLC_PREAMBLE_PATTERN_01:    val = 0xaa; break;
	default:                          val = 0x7e; break;
	}
	wr_reg8(info, TPR, (unsigned char)val);

	/* RCR (rx control)
	 *
	 * 15..13  mode, 000=HDLC 001=raw sync
	 * 12..10  encoding
	 * 09      CRC enable
	 * 08      CRC32
	 * 07..03  reserved, must be 0
	 * 02      reset
	 * 01      enable
	 * 00      auto-DCD enable
	 */
	val = 0;

	if (info->params.mode == MGSL_MODE_RAW)
		val |= BIT13;

	switch(info->params.encoding)
	{
	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
	}

	switch (info->params.crc_type & HDLC_CRC_MASK)
	{
	case HDLC_CRC_16_CCITT: val |= BIT9; break;
	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
	}

	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
		val |= BIT0;

	wr_reg16(info, RCR, val);

	/* CCR (clock control)
	 *
	 * 07..05  tx clock source
	 * 04..02  rx clock source
	 * 01      auxclk enable
	 * 00      BRG enable
	 */
	val = 0;

	if (info->params.flags & HDLC_FLAG_TXC_BRG)
	{
		// when RxC source is DPLL, BRG generates 16X DPLL
		// reference clock, so take TxC from BRG/16 to get
		// transmit clock at actual data rate
		if (info->params.flags & HDLC_FLAG_RXC_DPLL)
			val |= BIT6 + BIT5;	/* 011, txclk = BRG/16 */
		else
			val |= BIT6;	/* 010, txclk = BRG */
	}
	else if (info->params.flags & HDLC_FLAG_TXC_DPLL)
		val |= BIT7;	/* 100, txclk = DPLL Input */
	else if (info->params.flags & HDLC_FLAG_TXC_RXCPIN)
		val |= BIT5;	/* 001, txclk = RXC Input */

	if (info->params.flags & HDLC_FLAG_RXC_BRG)
		val |= BIT3;	/* 010, rxclk = BRG */
	else if (info->params.flags & HDLC_FLAG_RXC_DPLL)
		val |= BIT4;	/* 100, rxclk = DPLL */
	else if (info->params.flags & HDLC_FLAG_RXC_TXCPIN)
		val |= BIT2;	/* 001, rxclk = TXC Input */

	if (info->params.clock_speed)
		val |= BIT1 + BIT0;

	wr_reg8(info, CCR, (unsigned char)val);

	if (info->params.flags & (HDLC_FLAG_TXC_DPLL + HDLC_FLAG_RXC_DPLL))
	{
		// program DPLL mode
		switch(info->params.encoding)
		{
		case HDLC_ENCODING_BIPHASE_MARK:
		case HDLC_ENCODING_BIPHASE_SPACE:
			val = BIT7; break;
		case HDLC_ENCODING_BIPHASE_LEVEL:
		case HDLC_ENCODING_DIFF_BIPHASE_LEVEL:
			val = BIT7 + BIT6; break;
		default: val = BIT6;	// NRZ encodings
		}
		wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | val));

		// DPLL requires a 16X reference clock from BRG
		set_rate(info, info->params.clock_speed * 16);
	}
	else
		set_rate(info, info->params.clock_speed);

	tx_set_idle(info);

	msc_set_vcr(info);

	/* SCR (serial control)
	 *
	 * 15  1=tx req on FIFO half empty
	 * 14  1=rx req on FIFO half full
	 * 13  tx data  IRQ enable
	 * 12  tx idle  IRQ enable
	 * 11  underrun IRQ enable
	 * 10  rx data  IRQ enable
	 * 09  rx idle  IRQ enable
	 * 08  overrun  IRQ enable
	 * 07  DSR      IRQ enable
	 * 06  CTS      IRQ enable
	 * 05  DCD      IRQ enable
	 * 04  RI       IRQ enable
	 * 03  reserved, must be zero
	 * 02  1=txd->rxd internal loopback enable
	 * 01  reserved, must be zero
	 * 00  1=master IRQ enable
	 */
	wr_reg16(info, SCR, BIT15 + BIT14 + BIT0);

	if (info->params.loopback)
		enable_loopback(info);
}

/*
 *  set transmit idle mode
 */
static void tx_set_idle(struct slgt_info *info)
{
	unsigned char val;
	unsigned short tcr;

	/* if preamble enabled (tcr[6] == 1) then tx idle size = 8 bits
	 * else tcr[5:4] = tx idle size: 00 = 8 bits, 01 = 16 bits
	 */
	tcr = rd_reg16(info, TCR);
	if (info->idle_mode & HDLC_TXIDLE_CUSTOM_16) {
		/* disable preamble, set idle size to 16 bits */
		tcr = (tcr & ~(BIT6 + BIT5)) | BIT4;
		/* MSB of 16 bit idle specified in tx preamble register (TPR) */
		wr_reg8(info, TPR, (unsigned char)((info->idle_mode >> 8) & 0xff));
	} else if (!(tcr & BIT6)) {
		/* preamble is disabled, set idle size to 8 bits */
		tcr &= ~(BIT5 + BIT4);
	}
	wr_reg16(info, TCR, tcr);

	if (info->idle_mode & (HDLC_TXIDLE_CUSTOM_8 | HDLC_TXIDLE_CUSTOM_16)) {
		/* LSB of custom tx idle specified in tx idle register */
		val = (unsigned char)(info->idle_mode & 0xff);
	} else {
		/* standard 8 bit idle patterns */
		switch(info->idle_mode)
		{
		case HDLC_TXIDLE_FLAGS:          val = 0x7e; break;
		case HDLC_TXIDLE_ALT_ZEROS_ONES:
		case HDLC_TXIDLE_ALT_MARK_SPACE: val = 0xaa; break;
		case HDLC_TXIDLE_ZEROS:
		case HDLC_TXIDLE_SPACE:          val = 0x00; break;
		default:                         val = 0xff;
		}
	}

	wr_reg8(info, TIR, val);
}

/*
 * get state of V24 status (input) signals
 */
static void get_signals(struct slgt_info *info)
{
	unsigned short status = rd_reg16(info, SSR);

	/* clear all serial signals except DTR and RTS */
	info->signals &= SerialSignal_DTR + SerialSignal_RTS;

	if (status & BIT3)
		info->signals |= SerialSignal_DSR;
	if (status & BIT2)
		info->signals |= SerialSignal_CTS;
	if (status & BIT1)
		info->signals |= SerialSignal_DCD;
	if (status & BIT0)
		info->signals |= SerialSignal_RI;
}

/*
 * set V.24 Control Register based on current configuration
 */
static void msc_set_vcr(struct slgt_info *info)
{
	unsigned char val = 0;

	/* VCR (V.24 control)
	 *
	 * 07..04  serial IF select
	 * 03      DTR
	 * 02      RTS
	 * 01      LL
	 * 00      RL
	 */

	switch(info->if_mode & MGSL_INTERFACE_MASK)
	{
	case MGSL_INTERFACE_RS232:
		val |= BIT5; /* 0010 */
		break;
	case MGSL_INTERFACE_V35:
		val |= BIT7 + BIT6 + BIT5; /* 1110 */
		break;
	case MGSL_INTERFACE_RS422:
		val |= BIT6; /* 0100 */
		break;
	}

	if (info->signals & SerialSignal_DTR)
		val |= BIT3;
	if (info->signals & SerialSignal_RTS)
		val |= BIT2;
	if (info->if_mode & MGSL_INTERFACE_LL)
		val |= BIT1;
	if (info->if_mode & MGSL_INTERFACE_RL)
		val |= BIT0;
	wr_reg8(info, VCR, val);
}

/*
 * set state of V24 control (output) signals
 */
static void set_signals(struct slgt_info *info)
{
	unsigned char val = rd_reg8(info, VCR);
	if (info->signals & SerialSignal_DTR)
		val |= BIT3;
	else
		val &= ~BIT3;
	if (info->signals & SerialSignal_RTS)
		val |= BIT2;
	else
		val &= ~BIT2;
	wr_reg8(info, VCR, val);
}

/*
 * free range of receive DMA buffers (i to last)
 */
static void free_rbufs(struct slgt_info *info, unsigned int i, unsigned int last)
{
	int done = 0;

	while(!done) {
		/* reset current buffer for reuse */
		info->rbufs[i].status = 0;
		if (info->params.mode == MGSL_MODE_RAW)
			set_desc_count(info->rbufs[i], info->raw_rx_size);
		else
			set_desc_count(info->rbufs[i], DMABUFSIZE);

		if (i == last)
			done = 1;
		if (++i == info->rbuf_count)
			i = 0;
	}
	info->rbuf_current = i;
}

/*
 * mark all receive DMA buffers as free
 */
static void reset_rbufs(struct slgt_info *info)
{
	free_rbufs(info, 0, info->rbuf_count - 1);
}

/*
 * pass receive HDLC frame to upper layer
 *
 * return 1 if frame available, otherwise 0
 */
static int rx_get_frame(struct slgt_info *info)
{
	unsigned int start, end;
	unsigned short status;
	unsigned int framesize = 0;
	int rc = 0;
	unsigned long flags;
	struct tty_struct *tty = info->tty;
	unsigned char addr_field = 0xff;
	unsigned int crc_size = 0;

	switch (info->params.crc_type & HDLC_CRC_MASK) {
	case HDLC_CRC_16_CCITT: crc_size = 2; break;
	case HDLC_CRC_32_CCITT: crc_size = 4; break;
	}

check_again:

	framesize = 0;
	addr_field = 0xff;
	start = end = info->rbuf_current;

	for (;;) {
		if (!desc_complete(info->rbufs[end]))
			goto cleanup;

		if (framesize == 0 && info->params.addr_filter != 0xff)
			addr_field = info->rbufs[end].buf[0];

		framesize += desc_count(info->rbufs[end]);

		if (desc_eof(info->rbufs[end]))
			break;

		if (++end == info->rbuf_count)
			end = 0;

		if (end == info->rbuf_current) {
			if (info->rx_enabled){
				spin_lock_irqsave(&info->lock,flags);
				rx_start(info);
				spin_unlock_irqrestore(&info->lock,flags);
			}
			goto cleanup;
		}
	}

	/* status
	 *
	 * 15      buffer complete
	 * 14..06  reserved
	 * 05..04  residue
	 * 02      eof (end of frame)
	 * 01      CRC error
	 * 00      abort
	 */
	status = desc_status(info->rbufs[end]);

	/* ignore CRC bit if not using CRC (bit is undefined) */
	if ((info->params.crc_type & HDLC_CRC_MASK) == HDLC_CRC_NONE)
		status &= ~BIT1;

	if (framesize == 0 ||
		 (addr_field != 0xff && addr_field != info->params.addr_filter)) {
		free_rbufs(info, start, end);
		goto check_again;
	}

	if (framesize < (2 + crc_size) || status & BIT0) {
		info->icount.rxshort++;
		framesize = 0;
	} else if (status & BIT1) {
		info->icount.rxcrc++;
		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX))
			framesize = 0;
	}

#ifdef CONFIG_HDLC
	if (framesize == 0) {
		struct net_device_stats *stats = hdlc_stats(info->netdev);
		stats->rx_errors++;
		stats->rx_frame_errors++;
	}
#endif

	DBGBH(("%s rx frame status=%04X size=%d\n",
		info->device_name, status, framesize));
	DBGDATA(info, info->rbufs[start].buf, min_t(int, framesize, DMABUFSIZE), "rx");

	if (framesize) {
		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX)) {
			framesize -= crc_size;
			crc_size = 0;
		}

		if (framesize > info->max_frame_size + crc_size)
			info->icount.rxlong++;
		else {
			/* copy dma buffer(s) to contiguous temp buffer */
			int copy_count = framesize;
			int i = start;
			unsigned char *p = info->tmp_rbuf;
			info->tmp_rbuf_count = framesize;

			info->icount.rxok++;

			while(copy_count) {
				int partial_count = min(copy_count, DMABUFSIZE);
				memcpy(p, info->rbufs[i].buf, partial_count);
				p += partial_count;
				copy_count -= partial_count;
				if (++i == info->rbuf_count)
					i = 0;
			}

			if (info->params.crc_type & HDLC_CRC_RETURN_EX) {
				*p = (status & BIT1) ? RX_CRC_ERROR : RX_OK;
				framesize++;
			}

#ifdef CONFIG_HDLC
			if (info->netcount)
				hdlcdev_rx(info,info->tmp_rbuf, framesize);
			else
#endif
				ldisc_receive_buf(tty, info->tmp_rbuf, info->flag_buf, framesize);
		}
	}
	free_rbufs(info, start, end);
	rc = 1;

cleanup:
	return rc;
}

/*
 * pass receive buffer (RAW synchronous mode) to tty layer
 * return 1 if buffer available, otherwise 0
 */
static int rx_get_buf(struct slgt_info *info)
{
	unsigned int i = info->rbuf_current;

	if (!desc_complete(info->rbufs[i]))
		return 0;
	DBGDATA(info, info->rbufs[i].buf, desc_count(info->rbufs[i]), "rx");
	DBGINFO(("rx_get_buf size=%d\n", desc_count(info->rbufs[i])));
	ldisc_receive_buf(info->tty, info->rbufs[i].buf,
			  info->flag_buf, desc_count(info->rbufs[i]));
	free_rbufs(info, i, i);
	return 1;
}

static void reset_tbufs(struct slgt_info *info)
{
	unsigned int i;
	info->tbuf_current = 0;
	for (i=0 ; i < info->tbuf_count ; i++) {
		info->tbufs[i].status = 0;
		info->tbufs[i].count  = 0;
	}
}

/*
 * return number of free transmit DMA buffers
 */
static unsigned int free_tbuf_count(struct slgt_info *info)
{
	unsigned int count = 0;
	unsigned int i = info->tbuf_current;

	do
	{
		if (desc_count(info->tbufs[i]))
			break; /* buffer in use */
		++count;
		if (++i == info->tbuf_count)
			i=0;
	} while (i != info->tbuf_current);

	/* last buffer with zero count may be in use, assume it is */
	if (count)
		--count;

	return count;
}

/*
 * load transmit DMA buffer(s) with data
 */
static void tx_load(struct slgt_info *info, const char *buf, unsigned int size)
{
	unsigned short count;
	unsigned int i;
	struct slgt_desc *d;

	if (size == 0)
		return;

	DBGDATA(info, buf, size, "tx");

	info->tbuf_start = i = info->tbuf_current;

	while (size) {
		d = &info->tbufs[i];
		if (++i == info->tbuf_count)
			i = 0;

		count = (unsigned short)((size > DMABUFSIZE) ? DMABUFSIZE : size);
		memcpy(d->buf, buf, count);

		size -= count;
		buf  += count;

		if (!size && info->params.mode != MGSL_MODE_RAW)
			set_desc_eof(*d, 1); /* HDLC: set EOF of last desc */
		else
			set_desc_eof(*d, 0);

		set_desc_count(*d, count);
	}

	info->tbuf_current = i;
}

static int register_test(struct slgt_info *info)
{
	static unsigned short patterns[] =
		{0x0000, 0xffff, 0xaaaa, 0x5555, 0x6969, 0x9696};
	static unsigned int count = sizeof(patterns)/sizeof(patterns[0]);
	unsigned int i;
	int rc = 0;

	for (i=0 ; i < count ; i++) {
		wr_reg16(info, TIR, patterns[i]);
		wr_reg16(info, BDR, patterns[(i+1)%count]);
		if ((rd_reg16(info, TIR) != patterns[i]) ||
		    (rd_reg16(info, BDR) != patterns[(i+1)%count])) {
			rc = -ENODEV;
			break;
		}
	}
	info->gpio_present = (rd_reg32(info, JCR) & BIT5) ? 1 : 0;
	info->init_error = rc ? 0 : DiagStatus_AddressFailure;
	return rc;
}

static int irq_test(struct slgt_info *info)
{
	unsigned long timeout;
	unsigned long flags;
	struct tty_struct *oldtty = info->tty;
	u32 speed = info->params.data_rate;

	info->params.data_rate = 921600;
	info->tty = NULL;

	spin_lock_irqsave(&info->lock, flags);
	async_mode(info);
	slgt_irq_on(info, IRQ_TXIDLE);

	/* enable transmitter */
	wr_reg16(info, TCR,
		(unsigned short)(rd_reg16(info, TCR) | BIT1));

	/* write one byte and wait for tx idle */
	wr_reg16(info, TDR, 0);

	/* assume failure */
	info->init_error = DiagStatus_IrqFailure;
	info->irq_occurred = FALSE;

	spin_unlock_irqrestore(&info->lock, flags);

	timeout=100;
	while(timeout-- && !info->irq_occurred)
		msleep_interruptible(10);

	spin_lock_irqsave(&info->lock,flags);
	reset_port(info);
	spin_unlock_irqrestore(&info->lock,flags);

	info->params.data_rate = speed;
	info->tty = oldtty;

	info->init_error = info->irq_occurred ? 0 : DiagStatus_IrqFailure;
	return info->irq_occurred ? 0 : -ENODEV;
}

static int loopback_test_rx(struct slgt_info *info)
{
	unsigned char *src, *dest;
	int count;

	if (desc_complete(info->rbufs[0])) {
		count = desc_count(info->rbufs[0]);
		src   = info->rbufs[0].buf;
		dest  = info->tmp_rbuf;

		for( ; count ; count-=2, src+=2) {
			/* src=data byte (src+1)=status byte */
			if (!(*(src+1) & (BIT9 + BIT8))) {
				*dest = *src;
				dest++;
				info->tmp_rbuf_count++;
			}
		}
		DBGDATA(info, info->tmp_rbuf, info->tmp_rbuf_count, "rx");
		return 1;
	}
	return 0;
}

static int loopback_test(struct slgt_info *info)
{
#define TESTFRAMESIZE 20

	unsigned long timeout;
	u16 count = TESTFRAMESIZE;
	unsigned char buf[TESTFRAMESIZE];
	int rc = -ENODEV;
	unsigned long flags;

	struct tty_struct *oldtty = info->tty;
	MGSL_PARAMS params;

	memcpy(&params, &info->params, sizeof(params));

	info->params.mode = MGSL_MODE_ASYNC;
	info->params.data_rate = 921600;
	info->params.loopback = 1;
	info->tty = NULL;

	/* build and send transmit frame */
	for (count = 0; count < TESTFRAMESIZE; ++count)
		buf[count] = (unsigned char)count;

	info->tmp_rbuf_count = 0;
	memset(info->tmp_rbuf, 0, TESTFRAMESIZE);

	/* program hardware for HDLC and enabled receiver */
	spin_lock_irqsave(&info->lock,flags);
	async_mode(info);
	rx_start(info);
	info->tx_count = count;
	tx_load(info, buf, count);
	tx_start(info);
	spin_unlock_irqrestore(&info->lock, flags);

	/* wait for receive complete */
	for (timeout = 100; timeout; --timeout) {
		msleep_interruptible(10);
		if (loopback_test_rx(info)) {
			rc = 0;
			break;
		}
	}

	/* verify received frame length and contents */
	if (!rc && (info->tmp_rbuf_count != count ||
		  memcmp(buf, info->tmp_rbuf, count))) {
		rc = -ENODEV;
	}

	spin_lock_irqsave(&info->lock,flags);
	reset_adapter(info);
	spin_unlock_irqrestore(&info->lock,flags);

	memcpy(&info->params, &params, sizeof(info->params));
	info->tty = oldtty;

	info->init_error = rc ? DiagStatus_DmaFailure : 0;
	return rc;
}

static int adapter_test(struct slgt_info *info)
{
	DBGINFO(("testing %s\n", info->device_name));
	if (register_test(info) < 0) {
		printk("register test failure %s addr=%08X\n",
			info->device_name, info->phys_reg_addr);
	} else if (irq_test(info) < 0) {
		printk("IRQ test failure %s IRQ=%d\n",
			info->device_name, info->irq_level);
	} else if (loopback_test(info) < 0) {
		printk("loopback test failure %s\n", info->device_name);
	}
	return info->init_error;
}

/*
 * transmit timeout handler
 */
static void tx_timeout(unsigned long context)
{
	struct slgt_info *info = (struct slgt_info*)context;
	unsigned long flags;

	DBGINFO(("%s tx_timeout\n", info->device_name));
	if(info->tx_active && info->params.mode == MGSL_MODE_HDLC) {
		info->icount.txtimeout++;
	}
	spin_lock_irqsave(&info->lock,flags);
	info->tx_active = 0;
	info->tx_count = 0;
	spin_unlock_irqrestore(&info->lock,flags);

#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlcdev_tx_done(info);
	else
#endif
		bh_transmit(info);
}

/*
 * receive buffer polling timer
 */
static void rx_timeout(unsigned long context)
{
	struct slgt_info *info = (struct slgt_info*)context;
	unsigned long flags;

	DBGINFO(("%s rx_timeout\n", info->device_name));
	spin_lock_irqsave(&info->lock, flags);
	info->pending_bh |= BH_RECEIVE;
	spin_unlock_irqrestore(&info->lock, flags);
	bh_handler(info);
}