summaryrefslogtreecommitdiff
path: root/drivers/usb/serial/cp210x.c
blob: 832ad592b7ef3bed8411922c9fec294591ea0756 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
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
// SPDX-License-Identifier: GPL-2.0
/*
 * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
 *
 * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
 * Copyright (C) 2010-2021 Johan Hovold (johan@kernel.org)
 *
 * Support to set flow control line levels using TIOCMGET and TIOCMSET
 * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
 * control thanks to Munir Nassar nassarmu@real-time.com
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/gpio/driver.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"

/*
 * Function Prototypes
 */
static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
static void cp210x_close(struct usb_serial_port *);
static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
				const struct ktermios *);
static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
			       const struct ktermios *);
static bool cp210x_tx_empty(struct usb_serial_port *port);
static int cp210x_tiocmget(struct tty_struct *);
static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
static int cp210x_tiocmset_port(struct usb_serial_port *port,
		unsigned int, unsigned int);
static void cp210x_break_ctl(struct tty_struct *, int);
static int cp210x_attach(struct usb_serial *);
static void cp210x_disconnect(struct usb_serial *);
static void cp210x_release(struct usb_serial *);
static int cp210x_port_probe(struct usb_serial_port *);
static void cp210x_port_remove(struct usb_serial_port *);
static void cp210x_dtr_rts(struct usb_serial_port *port, int on);
static void cp210x_process_read_urb(struct urb *urb);
static void cp210x_enable_event_mode(struct usb_serial_port *port);
static void cp210x_disable_event_mode(struct usb_serial_port *port);

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x0404, 0x034C) },	/* NCR Retail IO Box */
	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
	{ USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
	{ USB_DEVICE(0x0908, 0x0070) }, /* Siemens SCALANCE LPE-9000 USB Serial Console */
	{ USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
	{ USB_DEVICE(0x0988, 0x0578) }, /* Teraoka AD2000 */
	{ USB_DEVICE(0x0B00, 0x3070) }, /* Ingenico 3070 */
	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
	{ USB_DEVICE(0x106F, 0x0003) },	/* CPI / Money Controls Bulk Coin Recycler */
	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
	{ USB_DEVICE(0x10C4, 0x8056) }, /* Lorenz Messtechnik devices */
	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
	{ USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
	{ USB_DEVICE(0x10C4, 0x817C) }, /* CESINEL MEDCAL N Power Quality Monitor */
	{ USB_DEVICE(0x10C4, 0x817D) }, /* CESINEL MEDCAL NT Power Quality Monitor */
	{ USB_DEVICE(0x10C4, 0x817E) }, /* CESINEL MEDCAL S Power Quality Monitor */
	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
	{ USB_DEVICE(0x10C4, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
	{ USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
	{ USB_DEVICE(0x10C4, 0x82EF) }, /* CESINEL FALCO 6105 AC Power Supply */
	{ USB_DEVICE(0x10C4, 0x82F1) }, /* CESINEL MEDCAL EFD Earth Fault Detector */
	{ USB_DEVICE(0x10C4, 0x82F2) }, /* CESINEL MEDCAL ST Network Analyzer */
	{ USB_DEVICE(0x10C4, 0x82F4) }, /* Starizona MicroTouch */
	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
	{ USB_DEVICE(0x10C4, 0x83AA) }, /* Mark-10 Digital Force Gauge */
	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
	{ USB_DEVICE(0x10C4, 0x8414) }, /* Decagon USB Cable Adapter */
	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
	{ USB_DEVICE(0x10C4, 0x8470) }, /* Juniper Networks BX Series System Console */
	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
	{ USB_DEVICE(0x10C4, 0x84B6) }, /* Starizona Hyperion */
	{ USB_DEVICE(0x10C4, 0x851E) }, /* CESINEL MEDCAL PT Network Analyzer */
	{ USB_DEVICE(0x10C4, 0x85A7) }, /* LifeScan OneTouch Verio IQ */
	{ USB_DEVICE(0x10C4, 0x85B8) }, /* CESINEL ReCon T Energy Logger */
	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
	{ USB_DEVICE(0x10C4, 0x8856) },	/* CEL EM357 ZigBee USB Stick - LR */
	{ USB_DEVICE(0x10C4, 0x8857) },	/* CEL EM357 ZigBee USB Stick */
	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
	{ USB_DEVICE(0x10C4, 0x88D8) }, /* Acuity Brands nLight Air Adapter */
	{ USB_DEVICE(0x10C4, 0x88FB) }, /* CESINEL MEDCAL STII Network Analyzer */
	{ USB_DEVICE(0x10C4, 0x8938) }, /* CESINEL MEDCAL S II Network Analyzer */
	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
	{ USB_DEVICE(0x10C4, 0x8962) }, /* Brim Brothers charging dock */
	{ USB_DEVICE(0x10C4, 0x8977) },	/* CEL MeshWorks DevKit Device */
	{ USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
	{ USB_DEVICE(0x10C4, 0x89A4) }, /* CESINEL FTBC Flexible Thyristor Bridge Controller */
	{ USB_DEVICE(0x10C4, 0x89FB) }, /* Qivicon ZigBee USB Radio Stick */
	{ USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
	{ USB_DEVICE(0x10C4, 0x8A5B) }, /* CEL EM3588 ZigBee USB Stick */
	{ USB_DEVICE(0x10C4, 0x8A5E) }, /* CEL EM3588 ZigBee USB Stick Long Range */
	{ USB_DEVICE(0x10C4, 0x8B34) }, /* Qivicon ZigBee USB Radio Stick */
	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA63) }, /* Silicon Labs Windows Update (CP2101-4/CP2102N) */
	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
	{ USB_DEVICE(0x10C4, 0xEA7A) }, /* Silicon Labs Windows Update (CP2105) */
	{ USB_DEVICE(0x10C4, 0xEA7B) }, /* Silicon Labs Windows Update (CP2108) */
	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
	{ USB_DEVICE(0x12B8, 0xEC60) }, /* Link G4 ECU */
	{ USB_DEVICE(0x12B8, 0xEC62) }, /* Link G4+ ECU */
	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
	{ USB_DEVICE(0x155A, 0x1006) },	/* ELDAT Easywave RX09 */
	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
	{ USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
	{ USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
	{ USB_DEVICE(0x17A8, 0x0011) }, /* Kamstrup 444 MHz RF sniffer */
	{ USB_DEVICE(0x17A8, 0x0013) }, /* Kamstrup 870 MHz RF sniffer */
	{ USB_DEVICE(0x17A8, 0x0101) }, /* Kamstrup 868 MHz wM-Bus C-Mode Meter Reader (Int Ant) */
	{ USB_DEVICE(0x17A8, 0x0102) }, /* Kamstrup 868 MHz wM-Bus C-Mode Meter Reader (Ext Ant) */
	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
	{ USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
	{ USB_DEVICE(0x18EF, 0xE030) }, /* ELV ALC 8xxx Battery Charger */
	{ USB_DEVICE(0x18EF, 0xE032) }, /* ELV TFD500 Data Logger */
	{ USB_DEVICE(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
	{ USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
	{ USB_DEVICE(0x1901, 0x0194) },	/* GE Healthcare Remote Alarm Box */
	{ USB_DEVICE(0x1901, 0x0195) },	/* GE B850/B650/B450 CP2104 DP UART interface */
	{ USB_DEVICE(0x1901, 0x0196) },	/* GE B850 CP2105 DP UART interface */
	{ USB_DEVICE(0x1901, 0x0197) }, /* GE CS1000 M.2 Key E serial interface */
	{ USB_DEVICE(0x1901, 0x0198) }, /* GE CS1000 Display serial interface */
	{ USB_DEVICE(0x199B, 0xBA30) }, /* LORD WSDA-200-USB */
	{ USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
	{ USB_DEVICE(0x2184, 0x0030) }, /* GW Instek GDM-834x Digital Multimeter */
	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
	{ USB_DEVICE(0x3923, 0x7A0B) }, /* National Instruments USB Serial Console */
	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
	{ } /* Terminating Entry */
};

MODULE_DEVICE_TABLE(usb, id_table);

struct cp210x_serial_private {
#ifdef CONFIG_GPIOLIB
	struct gpio_chip	gc;
	bool			gpio_registered;
	u16			gpio_pushpull;
	u16			gpio_altfunc;
	u16			gpio_input;
#endif
	u8			partnum;
	u32			fw_version;
	speed_t			min_speed;
	speed_t			max_speed;
	bool			use_actual_rate;
	bool			no_flow_control;
	bool			no_event_mode;
};

enum cp210x_event_state {
	ES_DATA,
	ES_ESCAPE,
	ES_LSR,
	ES_LSR_DATA_0,
	ES_LSR_DATA_1,
	ES_MSR
};

struct cp210x_port_private {
	u8			bInterfaceNumber;
	bool			event_mode;
	enum cp210x_event_state event_state;
	u8			lsr;

	struct mutex		mutex;
	bool			crtscts;
	bool			dtr;
	bool			rts;
};

static struct usb_serial_driver cp210x_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"cp210x",
	},
	.id_table		= id_table,
	.num_ports		= 1,
	.bulk_in_size		= 256,
	.bulk_out_size		= 256,
	.open			= cp210x_open,
	.close			= cp210x_close,
	.break_ctl		= cp210x_break_ctl,
	.set_termios		= cp210x_set_termios,
	.tx_empty		= cp210x_tx_empty,
	.throttle		= usb_serial_generic_throttle,
	.unthrottle		= usb_serial_generic_unthrottle,
	.tiocmget		= cp210x_tiocmget,
	.tiocmset		= cp210x_tiocmset,
	.get_icount		= usb_serial_generic_get_icount,
	.attach			= cp210x_attach,
	.disconnect		= cp210x_disconnect,
	.release		= cp210x_release,
	.port_probe		= cp210x_port_probe,
	.port_remove		= cp210x_port_remove,
	.dtr_rts		= cp210x_dtr_rts,
	.process_read_urb	= cp210x_process_read_urb,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&cp210x_device, NULL
};

/* Config request types */
#define REQTYPE_HOST_TO_INTERFACE	0x41
#define REQTYPE_INTERFACE_TO_HOST	0xc1
#define REQTYPE_HOST_TO_DEVICE	0x40
#define REQTYPE_DEVICE_TO_HOST	0xc0

/* Config request codes */
#define CP210X_IFC_ENABLE	0x00
#define CP210X_SET_BAUDDIV	0x01
#define CP210X_GET_BAUDDIV	0x02
#define CP210X_SET_LINE_CTL	0x03
#define CP210X_GET_LINE_CTL	0x04
#define CP210X_SET_BREAK	0x05
#define CP210X_IMM_CHAR		0x06
#define CP210X_SET_MHS		0x07
#define CP210X_GET_MDMSTS	0x08
#define CP210X_SET_XON		0x09
#define CP210X_SET_XOFF		0x0A
#define CP210X_SET_EVENTMASK	0x0B
#define CP210X_GET_EVENTMASK	0x0C
#define CP210X_SET_CHAR		0x0D
#define CP210X_GET_CHARS	0x0E
#define CP210X_GET_PROPS	0x0F
#define CP210X_GET_COMM_STATUS	0x10
#define CP210X_RESET		0x11
#define CP210X_PURGE		0x12
#define CP210X_SET_FLOW		0x13
#define CP210X_GET_FLOW		0x14
#define CP210X_EMBED_EVENTS	0x15
#define CP210X_GET_EVENTSTATE	0x16
#define CP210X_SET_CHARS	0x19
#define CP210X_GET_BAUDRATE	0x1D
#define CP210X_SET_BAUDRATE	0x1E
#define CP210X_VENDOR_SPECIFIC	0xFF

/* CP210X_IFC_ENABLE */
#define UART_ENABLE		0x0001
#define UART_DISABLE		0x0000

/* CP210X_(SET|GET)_BAUDDIV */
#define BAUD_RATE_GEN_FREQ	0x384000

/* CP210X_(SET|GET)_LINE_CTL */
#define BITS_DATA_MASK		0X0f00
#define BITS_DATA_5		0X0500
#define BITS_DATA_6		0X0600
#define BITS_DATA_7		0X0700
#define BITS_DATA_8		0X0800
#define BITS_DATA_9		0X0900

#define BITS_PARITY_MASK	0x00f0
#define BITS_PARITY_NONE	0x0000
#define BITS_PARITY_ODD		0x0010
#define BITS_PARITY_EVEN	0x0020
#define BITS_PARITY_MARK	0x0030
#define BITS_PARITY_SPACE	0x0040

#define BITS_STOP_MASK		0x000f
#define BITS_STOP_1		0x0000
#define BITS_STOP_1_5		0x0001
#define BITS_STOP_2		0x0002

/* CP210X_SET_BREAK */
#define BREAK_ON		0x0001
#define BREAK_OFF		0x0000

/* CP210X_(SET_MHS|GET_MDMSTS) */
#define CONTROL_DTR		0x0001
#define CONTROL_RTS		0x0002
#define CONTROL_CTS		0x0010
#define CONTROL_DSR		0x0020
#define CONTROL_RING		0x0040
#define CONTROL_DCD		0x0080
#define CONTROL_WRITE_DTR	0x0100
#define CONTROL_WRITE_RTS	0x0200

/* CP210X_(GET|SET)_CHARS */
struct cp210x_special_chars {
	u8	bEofChar;
	u8	bErrorChar;
	u8	bBreakChar;
	u8	bEventChar;
	u8	bXonChar;
	u8	bXoffChar;
};

/* CP210X_VENDOR_SPECIFIC values */
#define CP210X_GET_FW_VER	0x000E
#define CP210X_READ_2NCONFIG	0x000E
#define CP210X_GET_FW_VER_2N	0x0010
#define CP210X_READ_LATCH	0x00C2
#define CP210X_GET_PARTNUM	0x370B
#define CP210X_GET_PORTCONFIG	0x370C
#define CP210X_GET_DEVICEMODE	0x3711
#define CP210X_WRITE_LATCH	0x37E1

/* Part number definitions */
#define CP210X_PARTNUM_CP2101	0x01
#define CP210X_PARTNUM_CP2102	0x02
#define CP210X_PARTNUM_CP2103	0x03
#define CP210X_PARTNUM_CP2104	0x04
#define CP210X_PARTNUM_CP2105	0x05
#define CP210X_PARTNUM_CP2108	0x08
#define CP210X_PARTNUM_CP2102N_QFN28	0x20
#define CP210X_PARTNUM_CP2102N_QFN24	0x21
#define CP210X_PARTNUM_CP2102N_QFN20	0x22
#define CP210X_PARTNUM_UNKNOWN	0xFF

/* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
struct cp210x_comm_status {
	__le32   ulErrors;
	__le32   ulHoldReasons;
	__le32   ulAmountInInQueue;
	__le32   ulAmountInOutQueue;
	u8       bEofReceived;
	u8       bWaitForImmediate;
	u8       bReserved;
} __packed;

/*
 * CP210X_PURGE - 16 bits passed in wValue of USB request.
 * SiLabs app note AN571 gives a strange description of the 4 bits:
 * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
 * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
 */
#define PURGE_ALL		0x000f

/* CP210X_EMBED_EVENTS */
#define CP210X_ESCCHAR		0xec

#define CP210X_LSR_OVERRUN	BIT(1)
#define CP210X_LSR_PARITY	BIT(2)
#define CP210X_LSR_FRAME	BIT(3)
#define CP210X_LSR_BREAK	BIT(4)


/* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */
struct cp210x_flow_ctl {
	__le32	ulControlHandshake;
	__le32	ulFlowReplace;
	__le32	ulXonLimit;
	__le32	ulXoffLimit;
};

/* cp210x_flow_ctl::ulControlHandshake */
#define CP210X_SERIAL_DTR_MASK		GENMASK(1, 0)
#define CP210X_SERIAL_DTR_INACTIVE	(0 << 0)
#define CP210X_SERIAL_DTR_ACTIVE	(1 << 0)
#define CP210X_SERIAL_DTR_FLOW_CTL	(2 << 0)
#define CP210X_SERIAL_CTS_HANDSHAKE	BIT(3)
#define CP210X_SERIAL_DSR_HANDSHAKE	BIT(4)
#define CP210X_SERIAL_DCD_HANDSHAKE	BIT(5)
#define CP210X_SERIAL_DSR_SENSITIVITY	BIT(6)

/* cp210x_flow_ctl::ulFlowReplace */
#define CP210X_SERIAL_AUTO_TRANSMIT	BIT(0)
#define CP210X_SERIAL_AUTO_RECEIVE	BIT(1)
#define CP210X_SERIAL_ERROR_CHAR	BIT(2)
#define CP210X_SERIAL_NULL_STRIPPING	BIT(3)
#define CP210X_SERIAL_BREAK_CHAR	BIT(4)
#define CP210X_SERIAL_RTS_MASK		GENMASK(7, 6)
#define CP210X_SERIAL_RTS_INACTIVE	(0 << 6)
#define CP210X_SERIAL_RTS_ACTIVE	(1 << 6)
#define CP210X_SERIAL_RTS_FLOW_CTL	(2 << 6)
#define CP210X_SERIAL_XOFF_CONTINUE	BIT(31)

/* CP210X_VENDOR_SPECIFIC, CP210X_GET_DEVICEMODE call reads these 0x2 bytes. */
struct cp210x_pin_mode {
	u8	eci;
	u8	sci;
};

#define CP210X_PIN_MODE_MODEM		0
#define CP210X_PIN_MODE_GPIO		BIT(0)

/*
 * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xf bytes
 * on a CP2105 chip. Structure needs padding due to unused/unspecified bytes.
 */
struct cp210x_dual_port_config {
	__le16	gpio_mode;
	u8	__pad0[2];
	__le16	reset_state;
	u8	__pad1[4];
	__le16	suspend_state;
	u8	sci_cfg;
	u8	eci_cfg;
	u8	device_cfg;
} __packed;

/*
 * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xd bytes
 * on a CP2104 chip. Structure needs padding due to unused/unspecified bytes.
 */
struct cp210x_single_port_config {
	__le16	gpio_mode;
	u8	__pad0[2];
	__le16	reset_state;
	u8	__pad1[4];
	__le16	suspend_state;
	u8	device_cfg;
} __packed;

/* GPIO modes */
#define CP210X_SCI_GPIO_MODE_OFFSET	9
#define CP210X_SCI_GPIO_MODE_MASK	GENMASK(11, 9)

#define CP210X_ECI_GPIO_MODE_OFFSET	2
#define CP210X_ECI_GPIO_MODE_MASK	GENMASK(3, 2)

#define CP210X_GPIO_MODE_OFFSET		8
#define CP210X_GPIO_MODE_MASK		GENMASK(11, 8)

/* CP2105 port configuration values */
#define CP2105_GPIO0_TXLED_MODE		BIT(0)
#define CP2105_GPIO1_RXLED_MODE		BIT(1)
#define CP2105_GPIO1_RS485_MODE		BIT(2)

/* CP2104 port configuration values */
#define CP2104_GPIO0_TXLED_MODE		BIT(0)
#define CP2104_GPIO1_RXLED_MODE		BIT(1)
#define CP2104_GPIO2_RS485_MODE		BIT(2)

struct cp210x_quad_port_state {
	__le16 gpio_mode_pb0;
	__le16 gpio_mode_pb1;
	__le16 gpio_mode_pb2;
	__le16 gpio_mode_pb3;
	__le16 gpio_mode_pb4;

	__le16 gpio_lowpower_pb0;
	__le16 gpio_lowpower_pb1;
	__le16 gpio_lowpower_pb2;
	__le16 gpio_lowpower_pb3;
	__le16 gpio_lowpower_pb4;

	__le16 gpio_latch_pb0;
	__le16 gpio_latch_pb1;
	__le16 gpio_latch_pb2;
	__le16 gpio_latch_pb3;
	__le16 gpio_latch_pb4;
};

/*
 * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0x49 bytes
 * on a CP2108 chip.
 *
 * See https://www.silabs.com/documents/public/application-notes/an978-cp210x-usb-to-uart-api-specification.pdf
 */
struct cp210x_quad_port_config {
	struct cp210x_quad_port_state reset_state;
	struct cp210x_quad_port_state suspend_state;
	u8 ipdelay_ifc[4];
	u8 enhancedfxn_ifc[4];
	u8 enhancedfxn_device;
	u8 extclkfreq[4];
} __packed;

#define CP2108_EF_IFC_GPIO_TXLED		0x01
#define CP2108_EF_IFC_GPIO_RXLED		0x02
#define CP2108_EF_IFC_GPIO_RS485		0x04
#define CP2108_EF_IFC_GPIO_RS485_LOGIC		0x08
#define CP2108_EF_IFC_GPIO_CLOCK		0x10
#define CP2108_EF_IFC_DYNAMIC_SUSPEND		0x40

/* CP2102N configuration array indices */
#define CP210X_2NCONFIG_CONFIG_VERSION_IDX	2
#define CP210X_2NCONFIG_GPIO_MODE_IDX		581
#define CP210X_2NCONFIG_GPIO_RSTLATCH_IDX	587
#define CP210X_2NCONFIG_GPIO_CONTROL_IDX	600

/* CP2102N QFN20 port configuration values */
#define CP2102N_QFN20_GPIO2_TXLED_MODE		BIT(2)
#define CP2102N_QFN20_GPIO3_RXLED_MODE		BIT(3)
#define CP2102N_QFN20_GPIO1_RS485_MODE		BIT(4)
#define CP2102N_QFN20_GPIO0_CLK_MODE		BIT(6)

/*
 * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x02 bytes
 * for CP2102N, CP2103, CP2104 and CP2105.
 */
struct cp210x_gpio_write {
	u8	mask;
	u8	state;
};

/*
 * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x04 bytes
 * for CP2108.
 */
struct cp210x_gpio_write16 {
	__le16	mask;
	__le16	state;
};

/*
 * Helper to get interface number when we only have struct usb_serial.
 */
static u8 cp210x_interface_num(struct usb_serial *serial)
{
	struct usb_host_interface *cur_altsetting;

	cur_altsetting = serial->interface->cur_altsetting;

	return cur_altsetting->desc.bInterfaceNumber;
}

/*
 * Reads a variable-sized block of CP210X_ registers, identified by req.
 * Returns data into buf in native USB byte order.
 */
static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
		void *buf, int bufsize)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int result;


	result = usb_control_msg_recv(serial->dev, 0, req,
			REQTYPE_INTERFACE_TO_HOST, 0,
			port_priv->bInterfaceNumber, buf, bufsize,
			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
	if (result) {
		dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
				req, bufsize, result);
		return result;
	}

	return 0;
}

/*
 * Reads any 8-bit CP210X_ register identified by req.
 */
static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
{
	return cp210x_read_reg_block(port, req, val, sizeof(*val));
}

/*
 * Reads a variable-sized vendor block of CP210X_ registers, identified by val.
 * Returns data into buf in native USB byte order.
 */
static int cp210x_read_vendor_block(struct usb_serial *serial, u8 type, u16 val,
				    void *buf, int bufsize)
{
	int result;

	result = usb_control_msg_recv(serial->dev, 0, CP210X_VENDOR_SPECIFIC,
			type, val, cp210x_interface_num(serial), buf, bufsize,
			USB_CTRL_GET_TIMEOUT, GFP_KERNEL);
	if (result) {
		dev_err(&serial->interface->dev,
			"failed to get vendor val 0x%04x size %d: %d\n", val,
			bufsize, result);
		return result;
	}

	return 0;
}

/*
 * Writes any 16-bit CP210X_ register (req) whose value is passed
 * entirely in the wValue field of the USB request.
 */
static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int result;

	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
			req, REQTYPE_HOST_TO_INTERFACE, val,
			port_priv->bInterfaceNumber, NULL, 0,
			USB_CTRL_SET_TIMEOUT);
	if (result < 0) {
		dev_err(&port->dev, "failed set request 0x%x status: %d\n",
				req, result);
	}

	return result;
}

/*
 * Writes a variable-sized block of CP210X_ registers, identified by req.
 * Data in buf must be in native USB byte order.
 */
static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
		void *buf, int bufsize)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int result;

	result = usb_control_msg_send(serial->dev, 0, req,
			REQTYPE_HOST_TO_INTERFACE, 0,
			port_priv->bInterfaceNumber, buf, bufsize,
			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
	if (result) {
		dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
				req, bufsize, result);
		return result;
	}

	return 0;
}

/*
 * Writes any 32-bit CP210X_ register identified by req.
 */
static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
{
	__le32 le32_val;

	le32_val = cpu_to_le32(val);

	return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
}

#ifdef CONFIG_GPIOLIB
/*
 * Writes a variable-sized vendor block of CP210X_ registers, identified by val.
 * Data in buf must be in native USB byte order.
 */
static int cp210x_write_vendor_block(struct usb_serial *serial, u8 type,
				     u16 val, void *buf, int bufsize)
{
	int result;

	result = usb_control_msg_send(serial->dev, 0, CP210X_VENDOR_SPECIFIC,
			type, val, cp210x_interface_num(serial), buf, bufsize,
			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
	if (result) {
		dev_err(&serial->interface->dev,
			"failed to set vendor val 0x%04x size %d: %d\n", val,
			bufsize, result);
		return result;
	}

	return 0;
}
#endif

static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int result;

	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
	if (result) {
		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
		return result;
	}

	if (tty)
		cp210x_set_termios(tty, port, NULL);

	result = usb_serial_generic_open(tty, port);
	if (result)
		goto err_disable;

	return 0;

err_disable:
	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
	port_priv->event_mode = false;

	return result;
}

static void cp210x_close(struct usb_serial_port *port)
{
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);

	usb_serial_generic_close(port);

	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);

	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);

	/* Disabling the interface disables event-insertion mode. */
	port_priv->event_mode = false;
}

static void cp210x_process_lsr(struct usb_serial_port *port, unsigned char lsr, char *flag)
{
	if (lsr & CP210X_LSR_BREAK) {
		port->icount.brk++;
		*flag = TTY_BREAK;
	} else if (lsr & CP210X_LSR_PARITY) {
		port->icount.parity++;
		*flag = TTY_PARITY;
	} else if (lsr & CP210X_LSR_FRAME) {
		port->icount.frame++;
		*flag = TTY_FRAME;
	}

	if (lsr & CP210X_LSR_OVERRUN) {
		port->icount.overrun++;
		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
	}
}

static bool cp210x_process_char(struct usb_serial_port *port, unsigned char *ch, char *flag)
{
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);

	switch (port_priv->event_state) {
	case ES_DATA:
		if (*ch == CP210X_ESCCHAR) {
			port_priv->event_state = ES_ESCAPE;
			break;
		}
		return false;
	case ES_ESCAPE:
		switch (*ch) {
		case 0:
			dev_dbg(&port->dev, "%s - escape char\n", __func__);
			*ch = CP210X_ESCCHAR;
			port_priv->event_state = ES_DATA;
			return false;
		case 1:
			port_priv->event_state = ES_LSR_DATA_0;
			break;
		case 2:
			port_priv->event_state = ES_LSR;
			break;
		case 3:
			port_priv->event_state = ES_MSR;
			break;
		default:
			dev_err(&port->dev, "malformed event 0x%02x\n", *ch);
			port_priv->event_state = ES_DATA;
			break;
		}
		break;
	case ES_LSR_DATA_0:
		port_priv->lsr = *ch;
		port_priv->event_state = ES_LSR_DATA_1;
		break;
	case ES_LSR_DATA_1:
		dev_dbg(&port->dev, "%s - lsr = 0x%02x, data = 0x%02x\n",
				__func__, port_priv->lsr, *ch);
		cp210x_process_lsr(port, port_priv->lsr, flag);
		port_priv->event_state = ES_DATA;
		return false;
	case ES_LSR:
		dev_dbg(&port->dev, "%s - lsr = 0x%02x\n", __func__, *ch);
		port_priv->lsr = *ch;
		cp210x_process_lsr(port, port_priv->lsr, flag);
		port_priv->event_state = ES_DATA;
		break;
	case ES_MSR:
		dev_dbg(&port->dev, "%s - msr = 0x%02x\n", __func__, *ch);
		/* unimplemented */
		port_priv->event_state = ES_DATA;
		break;
	}

	return true;
}

static void cp210x_process_read_urb(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	unsigned char *ch = urb->transfer_buffer;
	char flag;
	int i;

	if (!urb->actual_length)
		return;

	if (port_priv->event_mode) {
		for (i = 0; i < urb->actual_length; i++, ch++) {
			flag = TTY_NORMAL;

			if (cp210x_process_char(port, ch, &flag))
				continue;

			tty_insert_flip_char(&port->port, *ch, flag);
		}
	} else {
		tty_insert_flip_string(&port->port, ch, urb->actual_length);
	}
	tty_flip_buffer_push(&port->port);
}

/*
 * Read how many bytes are waiting in the TX queue.
 */
static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
		u32 *count)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	struct cp210x_comm_status sts;
	int result;

	result = usb_control_msg_recv(serial->dev, 0, CP210X_GET_COMM_STATUS,
			REQTYPE_INTERFACE_TO_HOST, 0,
			port_priv->bInterfaceNumber, &sts, sizeof(sts),
			USB_CTRL_GET_TIMEOUT, GFP_KERNEL);
	if (result) {
		dev_err(&port->dev, "failed to get comm status: %d\n", result);
		return result;
	}

	*count = le32_to_cpu(sts.ulAmountInOutQueue);

	return 0;
}

static bool cp210x_tx_empty(struct usb_serial_port *port)
{
	int err;
	u32 count;

	err = cp210x_get_tx_queue_byte_count(port, &count);
	if (err)
		return true;

	return !count;
}

struct cp210x_rate {
	speed_t rate;
	speed_t high;
};

static const struct cp210x_rate cp210x_an205_table1[] = {
	{ 300, 300 },
	{ 600, 600 },
	{ 1200, 1200 },
	{ 1800, 1800 },
	{ 2400, 2400 },
	{ 4000, 4000 },
	{ 4800, 4803 },
	{ 7200, 7207 },
	{ 9600, 9612 },
	{ 14400, 14428 },
	{ 16000, 16062 },
	{ 19200, 19250 },
	{ 28800, 28912 },
	{ 38400, 38601 },
	{ 51200, 51558 },
	{ 56000, 56280 },
	{ 57600, 58053 },
	{ 64000, 64111 },
	{ 76800, 77608 },
	{ 115200, 117028 },
	{ 128000, 129347 },
	{ 153600, 156868 },
	{ 230400, 237832 },
	{ 250000, 254234 },
	{ 256000, 273066 },
	{ 460800, 491520 },
	{ 500000, 567138 },
	{ 576000, 670254 },
	{ 921600, UINT_MAX }
};

/*
 * Quantises the baud rate as per AN205 Table 1
 */
static speed_t cp210x_get_an205_rate(speed_t baud)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(cp210x_an205_table1); ++i) {
		if (baud <= cp210x_an205_table1[i].high)
			break;
	}

	return cp210x_an205_table1[i].rate;
}

static speed_t cp210x_get_actual_rate(speed_t baud)
{
	unsigned int prescale = 1;
	unsigned int div;

	if (baud <= 365)
		prescale = 4;

	div = DIV_ROUND_CLOSEST(48000000, 2 * prescale * baud);
	baud = 48000000 / (2 * prescale * div);

	return baud;
}

/*
 * CP2101 supports the following baud rates:
 *
 *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
 *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
 *
 * CP2102 and CP2103 support the following additional rates:
 *
 *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
 *	576000
 *
 * The device will map a requested rate to a supported one, but the result
 * of requests for rates greater than 1053257 is undefined (see AN205).
 *
 * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
 * respectively, with an error less than 1%. The actual rates are determined
 * by
 *
 *	div = round(freq / (2 x prescale x request))
 *	actual = freq / (2 x prescale x div)
 *
 * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
 * or 1 otherwise.
 * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
 * otherwise.
 */
static void cp210x_change_speed(struct tty_struct *tty,
				struct usb_serial_port *port,
				const struct ktermios *old_termios)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	u32 baud;

	if (tty->termios.c_ospeed == 0)
		return;

	/*
	 * This maps the requested rate to the actual rate, a valid rate on
	 * cp2102 or cp2103, or to an arbitrary rate in [1M, max_speed].
	 */
	baud = clamp(tty->termios.c_ospeed, priv->min_speed, priv->max_speed);

	if (priv->use_actual_rate)
		baud = cp210x_get_actual_rate(baud);
	else if (baud < 1000000)
		baud = cp210x_get_an205_rate(baud);

	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
		if (old_termios)
			baud = old_termios->c_ospeed;
		else
			baud = 9600;
	}

	tty_encode_baud_rate(tty, baud, baud);
}

static void cp210x_enable_event_mode(struct usb_serial_port *port)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int ret;

	if (port_priv->event_mode)
		return;

	if (priv->no_event_mode)
		return;

	port_priv->event_state = ES_DATA;
	port_priv->event_mode = true;

	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, CP210X_ESCCHAR);
	if (ret) {
		dev_err(&port->dev, "failed to enable events: %d\n", ret);
		port_priv->event_mode = false;
	}
}

static void cp210x_disable_event_mode(struct usb_serial_port *port)
{
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	int ret;

	if (!port_priv->event_mode)
		return;

	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, 0);
	if (ret) {
		dev_err(&port->dev, "failed to disable events: %d\n", ret);
		return;
	}

	port_priv->event_mode = false;
}

static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
{
	bool iflag_change, cc_change;

	iflag_change = ((a->c_iflag ^ b->c_iflag) & (INPCK | IXON | IXOFF));
	cc_change = a->c_cc[VSTART] != b->c_cc[VSTART] ||
			a->c_cc[VSTOP] != b->c_cc[VSTOP];

	return tty_termios_hw_change(a, b) || iflag_change || cc_change;
}

static void cp210x_set_flow_control(struct tty_struct *tty,
				    struct usb_serial_port *port,
				    const struct ktermios *old_termios)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	struct cp210x_special_chars chars;
	struct cp210x_flow_ctl flow_ctl;
	u32 flow_repl;
	u32 ctl_hs;
	bool crtscts;
	int ret;

	/*
	 * Some CP2102N interpret ulXonLimit as ulFlowReplace (erratum
	 * CP2102N_E104). Report back that flow control is not supported.
	 */
	if (priv->no_flow_control) {
		tty->termios.c_cflag &= ~CRTSCTS;
		tty->termios.c_iflag &= ~(IXON | IXOFF);
	}

	if (tty->termios.c_ospeed != 0 &&
			old_termios && old_termios->c_ospeed != 0 &&
			C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS) &&
			I_IXON(tty) == (old_termios->c_iflag & IXON) &&
			I_IXOFF(tty) == (old_termios->c_iflag & IXOFF) &&
			START_CHAR(tty) == old_termios->c_cc[VSTART] &&
			STOP_CHAR(tty) == old_termios->c_cc[VSTOP]) {
		return;
	}

	if (I_IXON(tty) || I_IXOFF(tty)) {
		memset(&chars, 0, sizeof(chars));

		chars.bXonChar = START_CHAR(tty);
		chars.bXoffChar = STOP_CHAR(tty);

		ret = cp210x_write_reg_block(port, CP210X_SET_CHARS, &chars,
				sizeof(chars));
		if (ret) {
			dev_err(&port->dev, "failed to set special chars: %d\n",
					ret);
		}
	}

	mutex_lock(&port_priv->mutex);

	if (tty->termios.c_ospeed == 0) {
		port_priv->dtr = false;
		port_priv->rts = false;
	} else if (old_termios && old_termios->c_ospeed == 0) {
		port_priv->dtr = true;
		port_priv->rts = true;
	}

	ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
			sizeof(flow_ctl));
	if (ret)
		goto out_unlock;

	ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
	flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);

	ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE;
	ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE;
	ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY;
	ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
	if (port_priv->dtr)
		ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
	else
		ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;

	flow_repl &= ~CP210X_SERIAL_RTS_MASK;
	if (C_CRTSCTS(tty)) {
		ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
		if (port_priv->rts)
			flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
		else
			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
		crtscts = true;
	} else {
		ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
		if (port_priv->rts)
			flow_repl |= CP210X_SERIAL_RTS_ACTIVE;
		else
			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
		crtscts = false;
	}

	if (I_IXOFF(tty)) {
		flow_repl |= CP210X_SERIAL_AUTO_RECEIVE;

		flow_ctl.ulXonLimit = cpu_to_le32(128);
		flow_ctl.ulXoffLimit = cpu_to_le32(128);
	} else {
		flow_repl &= ~CP210X_SERIAL_AUTO_RECEIVE;
	}

	if (I_IXON(tty))
		flow_repl |= CP210X_SERIAL_AUTO_TRANSMIT;
	else
		flow_repl &= ~CP210X_SERIAL_AUTO_TRANSMIT;

	dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n", __func__,
			ctl_hs, flow_repl);

	flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
	flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);

	ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
			sizeof(flow_ctl));
	if (ret)
		goto out_unlock;

	port_priv->crtscts = crtscts;
out_unlock:
	mutex_unlock(&port_priv->mutex);
}

static void cp210x_set_termios(struct tty_struct *tty,
		               struct usb_serial_port *port,
		               const struct ktermios *old_termios)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
	u16 bits;
	int ret;

	if (old_termios && !cp210x_termios_change(&tty->termios, old_termios) &&
			tty->termios.c_ospeed != 0)
		return;

	if (!old_termios || tty->termios.c_ospeed != old_termios->c_ospeed)
		cp210x_change_speed(tty, port, old_termios);

	/* CP2101 only supports CS8, 1 stop bit and non-stick parity. */
	if (priv->partnum == CP210X_PARTNUM_CP2101) {
		tty->termios.c_cflag &= ~(CSIZE | CSTOPB | CMSPAR);
		tty->termios.c_cflag |= CS8;
	}

	bits = 0;

	switch (C_CSIZE(tty)) {
	case CS5:
		bits |= BITS_DATA_5;
		break;
	case CS6:
		bits |= BITS_DATA_6;
		break;
	case CS7:
		bits |= BITS_DATA_7;
		break;
	case CS8:
	default:
		bits |= BITS_DATA_8;
		break;
	}

	if (C_PARENB(tty)) {
		if (C_CMSPAR(tty)) {
			if (C_PARODD(tty))
				bits |= BITS_PARITY_MARK;
			else
				bits |= BITS_PARITY_SPACE;
		} else {
			if (C_PARODD(tty))
				bits |= BITS_PARITY_ODD;
			else
				bits |= BITS_PARITY_EVEN;
		}
	}

	if (C_CSTOPB(tty))
		bits |= BITS_STOP_2;
	else
		bits |= BITS_STOP_1;

	ret = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
	if (ret)
		dev_err(&port->dev, "failed to set line control: %d\n", ret);

	cp210x_set_flow_control(tty, port, old_termios);

	/*
	 * Enable event-insertion mode only if input parity checking is
	 * enabled for now.
	 */
	if (I_INPCK(tty))
		cp210x_enable_event_mode(port);
	else
		cp210x_disable_event_mode(port);
}

static int cp210x_tiocmset(struct tty_struct *tty,
		unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	return cp210x_tiocmset_port(port, set, clear);
}

static int cp210x_tiocmset_port(struct usb_serial_port *port,
		unsigned int set, unsigned int clear)
{
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	struct cp210x_flow_ctl flow_ctl;
	u32 ctl_hs, flow_repl;
	u16 control = 0;
	int ret;

	mutex_lock(&port_priv->mutex);

	if (set & TIOCM_RTS) {
		port_priv->rts = true;
		control |= CONTROL_RTS;
		control |= CONTROL_WRITE_RTS;
	}
	if (set & TIOCM_DTR) {
		port_priv->dtr = true;
		control |= CONTROL_DTR;
		control |= CONTROL_WRITE_DTR;
	}
	if (clear & TIOCM_RTS) {
		port_priv->rts = false;
		control &= ~CONTROL_RTS;
		control |= CONTROL_WRITE_RTS;
	}
	if (clear & TIOCM_DTR) {
		port_priv->dtr = false;
		control &= ~CONTROL_DTR;
		control |= CONTROL_WRITE_DTR;
	}

	/*
	 * Use SET_FLOW to set DTR and enable/disable auto-RTS when hardware
	 * flow control is enabled.
	 */
	if (port_priv->crtscts && control & CONTROL_WRITE_RTS) {
		ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
				sizeof(flow_ctl));
		if (ret)
			goto out_unlock;

		ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
		flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);

		ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
		if (port_priv->dtr)
			ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
		else
			ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;

		flow_repl &= ~CP210X_SERIAL_RTS_MASK;
		if (port_priv->rts)
			flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
		else
			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;

		flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
		flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);

		dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n",
				__func__, ctl_hs, flow_repl);

		ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
				sizeof(flow_ctl));
	} else {
		dev_dbg(&port->dev, "%s - control = 0x%04x\n", __func__, control);

		ret = cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
	}
out_unlock:
	mutex_unlock(&port_priv->mutex);

	return ret;
}

static void cp210x_dtr_rts(struct usb_serial_port *port, int on)
{
	if (on)
		cp210x_tiocmset_port(port, TIOCM_DTR | TIOCM_RTS, 0);
	else
		cp210x_tiocmset_port(port, 0, TIOCM_DTR | TIOCM_RTS);
}

static int cp210x_tiocmget(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	u8 control;
	int result;

	result = cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
	if (result)
		return result;

	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
		|((control & CONTROL_RING)? TIOCM_RI  : 0)
		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);

	dev_dbg(&port->dev, "%s - control = 0x%02x\n", __func__, control);

	return result;
}

static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
{
	struct usb_serial_port *port = tty->driver_data;
	u16 state;

	if (break_state == 0)
		state = BREAK_OFF;
	else
		state = BREAK_ON;
	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
		state == BREAK_OFF ? "off" : "on");
	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
}

#ifdef CONFIG_GPIOLIB
static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	u8 req_type;
	u16 mask;
	int result;
	int len;

	result = usb_autopm_get_interface(serial->interface);
	if (result)
		return result;

	switch (priv->partnum) {
	case CP210X_PARTNUM_CP2105:
		req_type = REQTYPE_INTERFACE_TO_HOST;
		len = 1;
		break;
	case CP210X_PARTNUM_CP2108:
		req_type = REQTYPE_INTERFACE_TO_HOST;
		len = 2;
		break;
	default:
		req_type = REQTYPE_DEVICE_TO_HOST;
		len = 1;
		break;
	}

	mask = 0;
	result = cp210x_read_vendor_block(serial, req_type, CP210X_READ_LATCH,
					  &mask, len);

	usb_autopm_put_interface(serial->interface);

	if (result < 0)
		return result;

	le16_to_cpus(&mask);

	return !!(mask & BIT(gpio));
}

static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	struct cp210x_gpio_write16 buf16;
	struct cp210x_gpio_write buf;
	u16 mask, state;
	u16 wIndex;
	int result;

	if (value == 1)
		state = BIT(gpio);
	else
		state = 0;

	mask = BIT(gpio);

	result = usb_autopm_get_interface(serial->interface);
	if (result)
		goto out;

	switch (priv->partnum) {
	case CP210X_PARTNUM_CP2105:
		buf.mask = (u8)mask;
		buf.state = (u8)state;
		result = cp210x_write_vendor_block(serial,
						   REQTYPE_HOST_TO_INTERFACE,
						   CP210X_WRITE_LATCH, &buf,
						   sizeof(buf));
		break;
	case CP210X_PARTNUM_CP2108:
		buf16.mask = cpu_to_le16(mask);
		buf16.state = cpu_to_le16(state);
		result = cp210x_write_vendor_block(serial,
						   REQTYPE_HOST_TO_INTERFACE,
						   CP210X_WRITE_LATCH, &buf16,
						   sizeof(buf16));
		break;
	default:
		wIndex = state << 8 | mask;
		result = usb_control_msg(serial->dev,
					 usb_sndctrlpipe(serial->dev, 0),
					 CP210X_VENDOR_SPECIFIC,
					 REQTYPE_HOST_TO_DEVICE,
					 CP210X_WRITE_LATCH,
					 wIndex,
					 NULL, 0, USB_CTRL_SET_TIMEOUT);
		break;
	}

	usb_autopm_put_interface(serial->interface);
out:
	if (result < 0) {
		dev_err(&serial->interface->dev, "failed to set GPIO value: %d\n",
				result);
	}
}

static int cp210x_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);

	return priv->gpio_input & BIT(gpio);
}

static int cp210x_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);

	if (priv->partnum == CP210X_PARTNUM_CP2105) {
		/* hardware does not support an input mode */
		return -ENOTSUPP;
	}

	/* push-pull pins cannot be changed to be inputs */
	if (priv->gpio_pushpull & BIT(gpio))
		return -EINVAL;

	/* make sure to release pin if it is being driven low */
	cp210x_gpio_set(gc, gpio, 1);

	priv->gpio_input |= BIT(gpio);

	return 0;
}

static int cp210x_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
					int value)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);

	priv->gpio_input &= ~BIT(gpio);
	cp210x_gpio_set(gc, gpio, value);

	return 0;
}

static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio,
				  unsigned long config)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	enum pin_config_param param = pinconf_to_config_param(config);

	/* Succeed only if in correct mode (this can't be set at runtime) */
	if ((param == PIN_CONFIG_DRIVE_PUSH_PULL) &&
	    (priv->gpio_pushpull & BIT(gpio)))
		return 0;

	if ((param == PIN_CONFIG_DRIVE_OPEN_DRAIN) &&
	    !(priv->gpio_pushpull & BIT(gpio)))
		return 0;

	return -ENOTSUPP;
}

static int cp210x_gpio_init_valid_mask(struct gpio_chip *gc,
		unsigned long *valid_mask, unsigned int ngpios)
{
	struct usb_serial *serial = gpiochip_get_data(gc);
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	struct device *dev = &serial->interface->dev;
	unsigned long altfunc_mask = priv->gpio_altfunc;

	bitmap_complement(valid_mask, &altfunc_mask, ngpios);

	if (bitmap_empty(valid_mask, ngpios))
		dev_dbg(dev, "no pin configured for GPIO\n");
	else
		dev_dbg(dev, "GPIO.%*pbl configured for GPIO\n", ngpios,
				valid_mask);
	return 0;
}

/*
 * This function is for configuring GPIO using shared pins, where other signals
 * are made unavailable by configuring the use of GPIO. This is believed to be
 * only applicable to the cp2105 at this point, the other devices supported by
 * this driver that provide GPIO do so in a way that does not impact other
 * signals and are thus expected to have very different initialisation.
 */
static int cp2105_gpioconf_init(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	struct cp210x_pin_mode mode;
	struct cp210x_dual_port_config config;
	u8 intf_num = cp210x_interface_num(serial);
	u8 iface_config;
	int result;

	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
					  CP210X_GET_DEVICEMODE, &mode,
					  sizeof(mode));
	if (result < 0)
		return result;

	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
					  CP210X_GET_PORTCONFIG, &config,
					  sizeof(config));
	if (result < 0)
		return result;

	/*  2 banks of GPIO - One for the pins taken from each serial port */
	if (intf_num == 0) {
		priv->gc.ngpio = 2;

		if (mode.eci == CP210X_PIN_MODE_MODEM) {
			/* mark all GPIOs of this interface as reserved */
			priv->gpio_altfunc = 0xff;
			return 0;
		}

		iface_config = config.eci_cfg;
		priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
						CP210X_ECI_GPIO_MODE_MASK) >>
						CP210X_ECI_GPIO_MODE_OFFSET);
	} else if (intf_num == 1) {
		priv->gc.ngpio = 3;

		if (mode.sci == CP210X_PIN_MODE_MODEM) {
			/* mark all GPIOs of this interface as reserved */
			priv->gpio_altfunc = 0xff;
			return 0;
		}

		iface_config = config.sci_cfg;
		priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
						CP210X_SCI_GPIO_MODE_MASK) >>
						CP210X_SCI_GPIO_MODE_OFFSET);
	} else {
		return -ENODEV;
	}

	/* mark all pins which are not in GPIO mode */
	if (iface_config & CP2105_GPIO0_TXLED_MODE)	/* GPIO 0 */
		priv->gpio_altfunc |= BIT(0);
	if (iface_config & (CP2105_GPIO1_RXLED_MODE |	/* GPIO 1 */
			CP2105_GPIO1_RS485_MODE))
		priv->gpio_altfunc |= BIT(1);

	/* driver implementation for CP2105 only supports outputs */
	priv->gpio_input = 0;

	return 0;
}

static int cp2104_gpioconf_init(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	struct cp210x_single_port_config config;
	u8 iface_config;
	u8 gpio_latch;
	int result;
	u8 i;

	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
					  CP210X_GET_PORTCONFIG, &config,
					  sizeof(config));
	if (result < 0)
		return result;

	priv->gc.ngpio = 4;

	iface_config = config.device_cfg;
	priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
					CP210X_GPIO_MODE_MASK) >>
					CP210X_GPIO_MODE_OFFSET);
	gpio_latch = (u8)((le16_to_cpu(config.reset_state) &
					CP210X_GPIO_MODE_MASK) >>
					CP210X_GPIO_MODE_OFFSET);

	/* mark all pins which are not in GPIO mode */
	if (iface_config & CP2104_GPIO0_TXLED_MODE)	/* GPIO 0 */
		priv->gpio_altfunc |= BIT(0);
	if (iface_config & CP2104_GPIO1_RXLED_MODE)	/* GPIO 1 */
		priv->gpio_altfunc |= BIT(1);
	if (iface_config & CP2104_GPIO2_RS485_MODE)	/* GPIO 2 */
		priv->gpio_altfunc |= BIT(2);

	/*
	 * Like CP2102N, CP2104 has also no strict input and output pin
	 * modes.
	 * Do the same input mode emulation as CP2102N.
	 */
	for (i = 0; i < priv->gc.ngpio; ++i) {
		/*
		 * Set direction to "input" iff pin is open-drain and reset
		 * value is 1.
		 */
		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
			priv->gpio_input |= BIT(i);
	}

	return 0;
}

static int cp2108_gpio_init(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	struct cp210x_quad_port_config config;
	u16 gpio_latch;
	int result;
	u8 i;

	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
					  CP210X_GET_PORTCONFIG, &config,
					  sizeof(config));
	if (result < 0)
		return result;

	priv->gc.ngpio = 16;
	priv->gpio_pushpull = le16_to_cpu(config.reset_state.gpio_mode_pb1);
	gpio_latch = le16_to_cpu(config.reset_state.gpio_latch_pb1);

	/*
	 * Mark all pins which are not in GPIO mode.
	 *
	 * Refer to table 9.1 "GPIO Mode alternate Functions" in the datasheet:
	 * https://www.silabs.com/documents/public/data-sheets/cp2108-datasheet.pdf
	 *
	 * Alternate functions of GPIO0 to GPIO3 are determine by enhancedfxn_ifc[0]
	 * and the similarly for the other pins; enhancedfxn_ifc[1]: GPIO4 to GPIO7,
	 * enhancedfxn_ifc[2]: GPIO8 to GPIO11, enhancedfxn_ifc[3]: GPIO12 to GPIO15.
	 */
	for (i = 0; i < 4; i++) {
		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_TXLED)
			priv->gpio_altfunc |= BIT(i * 4);
		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_RXLED)
			priv->gpio_altfunc |= BIT((i * 4) + 1);
		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_RS485)
			priv->gpio_altfunc |= BIT((i * 4) + 2);
		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_CLOCK)
			priv->gpio_altfunc |= BIT((i * 4) + 3);
	}

	/*
	 * Like CP2102N, CP2108 has also no strict input and output pin
	 * modes. Do the same input mode emulation as CP2102N.
	 */
	for (i = 0; i < priv->gc.ngpio; ++i) {
		/*
		 * Set direction to "input" iff pin is open-drain and reset
		 * value is 1.
		 */
		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
			priv->gpio_input |= BIT(i);
	}

	return 0;
}

static int cp2102n_gpioconf_init(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	const u16 config_size = 0x02a6;
	u8 gpio_rst_latch;
	u8 config_version;
	u8 gpio_pushpull;
	u8 *config_buf;
	u8 gpio_latch;
	u8 gpio_ctrl;
	int result;
	u8 i;

	/*
	 * Retrieve device configuration from the device.
	 * The array received contains all customization settings done at the
	 * factory/manufacturer. Format of the array is documented at the
	 * time of writing at:
	 * https://www.silabs.com/community/interface/knowledge-base.entry.html/2017/03/31/cp2102n_setconfig-xsfa
	 */
	config_buf = kmalloc(config_size, GFP_KERNEL);
	if (!config_buf)
		return -ENOMEM;

	result = cp210x_read_vendor_block(serial,
					  REQTYPE_DEVICE_TO_HOST,
					  CP210X_READ_2NCONFIG,
					  config_buf,
					  config_size);
	if (result < 0) {
		kfree(config_buf);
		return result;
	}

	config_version = config_buf[CP210X_2NCONFIG_CONFIG_VERSION_IDX];
	gpio_pushpull = config_buf[CP210X_2NCONFIG_GPIO_MODE_IDX];
	gpio_ctrl = config_buf[CP210X_2NCONFIG_GPIO_CONTROL_IDX];
	gpio_rst_latch = config_buf[CP210X_2NCONFIG_GPIO_RSTLATCH_IDX];

	kfree(config_buf);

	/* Make sure this is a config format we understand. */
	if (config_version != 0x01)
		return -ENOTSUPP;

	priv->gc.ngpio = 4;

	/*
	 * Get default pin states after reset. Needed so we can determine
	 * the direction of an open-drain pin.
	 */
	gpio_latch = (gpio_rst_latch >> 3) & 0x0f;

	/* 0 indicates open-drain mode, 1 is push-pull */
	priv->gpio_pushpull = (gpio_pushpull >> 3) & 0x0f;

	/* 0 indicates GPIO mode, 1 is alternate function */
	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN20) {
		/* QFN20 is special... */
		if (gpio_ctrl & CP2102N_QFN20_GPIO0_CLK_MODE)   /* GPIO 0 */
			priv->gpio_altfunc |= BIT(0);
		if (gpio_ctrl & CP2102N_QFN20_GPIO1_RS485_MODE) /* GPIO 1 */
			priv->gpio_altfunc |= BIT(1);
		if (gpio_ctrl & CP2102N_QFN20_GPIO2_TXLED_MODE) /* GPIO 2 */
			priv->gpio_altfunc |= BIT(2);
		if (gpio_ctrl & CP2102N_QFN20_GPIO3_RXLED_MODE) /* GPIO 3 */
			priv->gpio_altfunc |= BIT(3);
	} else {
		priv->gpio_altfunc = (gpio_ctrl >> 2) & 0x0f;
	}

	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) {
		/*
		 * For the QFN28 package, GPIO4-6 are controlled by
		 * the low three bits of the mode/latch fields.
		 * Contrary to the document linked above, the bits for
		 * the SUSPEND pins are elsewhere.  No alternate
		 * function is available for these pins.
		 */
		priv->gc.ngpio = 7;
		gpio_latch |= (gpio_rst_latch & 7) << 4;
		priv->gpio_pushpull |= (gpio_pushpull & 7) << 4;
	}

	/*
	 * The CP2102N does not strictly has input and output pin modes,
	 * it only knows open-drain and push-pull modes which is set at
	 * factory. An open-drain pin can function both as an
	 * input or an output. We emulate input mode for open-drain pins
	 * by making sure they are not driven low, and we do not allow
	 * push-pull pins to be set as an input.
	 */
	for (i = 0; i < priv->gc.ngpio; ++i) {
		/*
		 * Set direction to "input" iff pin is open-drain and reset
		 * value is 1.
		 */
		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
			priv->gpio_input |= BIT(i);
	}

	return 0;
}

static int cp210x_gpio_init(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	int result;

	switch (priv->partnum) {
	case CP210X_PARTNUM_CP2104:
		result = cp2104_gpioconf_init(serial);
		break;
	case CP210X_PARTNUM_CP2105:
		result = cp2105_gpioconf_init(serial);
		break;
	case CP210X_PARTNUM_CP2108:
		/*
		 * The GPIOs are not tied to any specific port so only register
		 * once for interface 0.
		 */
		if (cp210x_interface_num(serial) != 0)
			return 0;
		result = cp2108_gpio_init(serial);
		break;
	case CP210X_PARTNUM_CP2102N_QFN28:
	case CP210X_PARTNUM_CP2102N_QFN24:
	case CP210X_PARTNUM_CP2102N_QFN20:
		result = cp2102n_gpioconf_init(serial);
		break;
	default:
		return 0;
	}

	if (result < 0)
		return result;

	priv->gc.label = "cp210x";
	priv->gc.get_direction = cp210x_gpio_direction_get;
	priv->gc.direction_input = cp210x_gpio_direction_input;
	priv->gc.direction_output = cp210x_gpio_direction_output;
	priv->gc.get = cp210x_gpio_get;
	priv->gc.set = cp210x_gpio_set;
	priv->gc.set_config = cp210x_gpio_set_config;
	priv->gc.init_valid_mask = cp210x_gpio_init_valid_mask;
	priv->gc.owner = THIS_MODULE;
	priv->gc.parent = &serial->interface->dev;
	priv->gc.base = -1;
	priv->gc.can_sleep = true;

	result = gpiochip_add_data(&priv->gc, serial);
	if (!result)
		priv->gpio_registered = true;

	return result;
}

static void cp210x_gpio_remove(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);

	if (priv->gpio_registered) {
		gpiochip_remove(&priv->gc);
		priv->gpio_registered = false;
	}
}

#else

static int cp210x_gpio_init(struct usb_serial *serial)
{
	return 0;
}

static void cp210x_gpio_remove(struct usb_serial *serial)
{
	/* Nothing to do */
}

#endif

static int cp210x_port_probe(struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv;

	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
	if (!port_priv)
		return -ENOMEM;

	port_priv->bInterfaceNumber = cp210x_interface_num(serial);
	mutex_init(&port_priv->mutex);

	usb_set_serial_port_data(port, port_priv);

	return 0;
}

static void cp210x_port_remove(struct usb_serial_port *port)
{
	struct cp210x_port_private *port_priv;

	port_priv = usb_get_serial_port_data(port);
	kfree(port_priv);
}

static void cp210x_init_max_speed(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	bool use_actual_rate = false;
	speed_t min = 300;
	speed_t max;

	switch (priv->partnum) {
	case CP210X_PARTNUM_CP2101:
		max = 921600;
		break;
	case CP210X_PARTNUM_CP2102:
	case CP210X_PARTNUM_CP2103:
		max = 1000000;
		break;
	case CP210X_PARTNUM_CP2104:
		use_actual_rate = true;
		max = 2000000;
		break;
	case CP210X_PARTNUM_CP2108:
		max = 2000000;
		break;
	case CP210X_PARTNUM_CP2105:
		if (cp210x_interface_num(serial) == 0) {
			use_actual_rate = true;
			max = 2000000;	/* ECI */
		} else {
			min = 2400;
			max = 921600;	/* SCI */
		}
		break;
	case CP210X_PARTNUM_CP2102N_QFN28:
	case CP210X_PARTNUM_CP2102N_QFN24:
	case CP210X_PARTNUM_CP2102N_QFN20:
		use_actual_rate = true;
		max = 3000000;
		break;
	default:
		max = 2000000;
		break;
	}

	priv->min_speed = min;
	priv->max_speed = max;
	priv->use_actual_rate = use_actual_rate;
}

static void cp2102_determine_quirks(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	u8 *buf;
	int ret;

	buf = kmalloc(2, GFP_KERNEL);
	if (!buf)
		return;
	/*
	 * Some (possibly counterfeit) CP2102 do not support event-insertion
	 * mode and respond differently to malformed vendor requests.
	 * Specifically, they return one instead of two bytes when sent a
	 * two-byte part-number request.
	 */
	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
			CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
			CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
	if (ret == 1) {
		dev_dbg(&serial->interface->dev,
				"device does not support event-insertion mode\n");
		priv->no_event_mode = true;
	}

	kfree(buf);
}

static int cp210x_get_fw_version(struct usb_serial *serial, u16 value)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	u8 ver[3];
	int ret;

	ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, value,
			ver, sizeof(ver));
	if (ret)
		return ret;

	dev_dbg(&serial->interface->dev, "%s - %d.%d.%d\n", __func__,
			ver[0], ver[1], ver[2]);

	priv->fw_version = ver[0] << 16 | ver[1] << 8 | ver[2];

	return 0;
}

static void cp210x_determine_type(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
	int ret;

	ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
			CP210X_GET_PARTNUM, &priv->partnum,
			sizeof(priv->partnum));
	if (ret < 0) {
		dev_warn(&serial->interface->dev,
				"querying part number failed\n");
		priv->partnum = CP210X_PARTNUM_UNKNOWN;
		return;
	}

	dev_dbg(&serial->interface->dev, "partnum = 0x%02x\n", priv->partnum);

	switch (priv->partnum) {
	case CP210X_PARTNUM_CP2102:
		cp2102_determine_quirks(serial);
		break;
	case CP210X_PARTNUM_CP2105:
	case CP210X_PARTNUM_CP2108:
		cp210x_get_fw_version(serial, CP210X_GET_FW_VER);
		break;
	case CP210X_PARTNUM_CP2102N_QFN28:
	case CP210X_PARTNUM_CP2102N_QFN24:
	case CP210X_PARTNUM_CP2102N_QFN20:
		ret = cp210x_get_fw_version(serial, CP210X_GET_FW_VER_2N);
		if (ret)
			break;
		if (priv->fw_version <= 0x10004)
			priv->no_flow_control = true;
		break;
	default:
		break;
	}
}

static int cp210x_attach(struct usb_serial *serial)
{
	int result;
	struct cp210x_serial_private *priv;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	usb_set_serial_data(serial, priv);

	cp210x_determine_type(serial);
	cp210x_init_max_speed(serial);

	result = cp210x_gpio_init(serial);
	if (result < 0) {
		dev_err(&serial->interface->dev, "GPIO initialisation failed: %d\n",
				result);
	}

	return 0;
}

static void cp210x_disconnect(struct usb_serial *serial)
{
	cp210x_gpio_remove(serial);
}

static void cp210x_release(struct usb_serial *serial)
{
	struct cp210x_serial_private *priv = usb_get_serial_data(serial);

	cp210x_gpio_remove(serial);

	kfree(priv);
}

module_usb_serial_driver(serial_drivers, id_table);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL v2");