summaryrefslogtreecommitdiff
path: root/drivers/net/phy/sfp.c
blob: 34e90216bd2cb7fedcbf0f22637cffc853ffe46b (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
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
// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/mdio/mdio-i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "sfp.h"
#include "swphy.h"

enum {
	GPIO_MODDEF0,
	GPIO_LOS,
	GPIO_TX_FAULT,
	GPIO_TX_DISABLE,
	GPIO_RATE_SELECT,
	GPIO_MAX,

	SFP_F_PRESENT = BIT(GPIO_MODDEF0),
	SFP_F_LOS = BIT(GPIO_LOS),
	SFP_F_TX_FAULT = BIT(GPIO_TX_FAULT),
	SFP_F_TX_DISABLE = BIT(GPIO_TX_DISABLE),
	SFP_F_RATE_SELECT = BIT(GPIO_RATE_SELECT),

	SFP_E_INSERT = 0,
	SFP_E_REMOVE,
	SFP_E_DEV_ATTACH,
	SFP_E_DEV_DETACH,
	SFP_E_DEV_DOWN,
	SFP_E_DEV_UP,
	SFP_E_TX_FAULT,
	SFP_E_TX_CLEAR,
	SFP_E_LOS_HIGH,
	SFP_E_LOS_LOW,
	SFP_E_TIMEOUT,

	SFP_MOD_EMPTY = 0,
	SFP_MOD_ERROR,
	SFP_MOD_PROBE,
	SFP_MOD_WAITDEV,
	SFP_MOD_HPOWER,
	SFP_MOD_WAITPWR,
	SFP_MOD_PRESENT,

	SFP_DEV_DETACHED = 0,
	SFP_DEV_DOWN,
	SFP_DEV_UP,

	SFP_S_DOWN = 0,
	SFP_S_FAIL,
	SFP_S_WAIT,
	SFP_S_INIT,
	SFP_S_INIT_PHY,
	SFP_S_INIT_TX_FAULT,
	SFP_S_WAIT_LOS,
	SFP_S_LINK_UP,
	SFP_S_TX_FAULT,
	SFP_S_REINIT,
	SFP_S_TX_DISABLE,
};

static const char  * const mod_state_strings[] = {
	[SFP_MOD_EMPTY] = "empty",
	[SFP_MOD_ERROR] = "error",
	[SFP_MOD_PROBE] = "probe",
	[SFP_MOD_WAITDEV] = "waitdev",
	[SFP_MOD_HPOWER] = "hpower",
	[SFP_MOD_WAITPWR] = "waitpwr",
	[SFP_MOD_PRESENT] = "present",
};

static const char *mod_state_to_str(unsigned short mod_state)
{
	if (mod_state >= ARRAY_SIZE(mod_state_strings))
		return "Unknown module state";
	return mod_state_strings[mod_state];
}

static const char * const dev_state_strings[] = {
	[SFP_DEV_DETACHED] = "detached",
	[SFP_DEV_DOWN] = "down",
	[SFP_DEV_UP] = "up",
};

static const char *dev_state_to_str(unsigned short dev_state)
{
	if (dev_state >= ARRAY_SIZE(dev_state_strings))
		return "Unknown device state";
	return dev_state_strings[dev_state];
}

static const char * const event_strings[] = {
	[SFP_E_INSERT] = "insert",
	[SFP_E_REMOVE] = "remove",
	[SFP_E_DEV_ATTACH] = "dev_attach",
	[SFP_E_DEV_DETACH] = "dev_detach",
	[SFP_E_DEV_DOWN] = "dev_down",
	[SFP_E_DEV_UP] = "dev_up",
	[SFP_E_TX_FAULT] = "tx_fault",
	[SFP_E_TX_CLEAR] = "tx_clear",
	[SFP_E_LOS_HIGH] = "los_high",
	[SFP_E_LOS_LOW] = "los_low",
	[SFP_E_TIMEOUT] = "timeout",
};

static const char *event_to_str(unsigned short event)
{
	if (event >= ARRAY_SIZE(event_strings))
		return "Unknown event";
	return event_strings[event];
}

static const char * const sm_state_strings[] = {
	[SFP_S_DOWN] = "down",
	[SFP_S_FAIL] = "fail",
	[SFP_S_WAIT] = "wait",
	[SFP_S_INIT] = "init",
	[SFP_S_INIT_PHY] = "init_phy",
	[SFP_S_INIT_TX_FAULT] = "init_tx_fault",
	[SFP_S_WAIT_LOS] = "wait_los",
	[SFP_S_LINK_UP] = "link_up",
	[SFP_S_TX_FAULT] = "tx_fault",
	[SFP_S_REINIT] = "reinit",
	[SFP_S_TX_DISABLE] = "rx_disable",
};

static const char *sm_state_to_str(unsigned short sm_state)
{
	if (sm_state >= ARRAY_SIZE(sm_state_strings))
		return "Unknown state";
	return sm_state_strings[sm_state];
}

static const char *gpio_of_names[] = {
	"mod-def0",
	"los",
	"tx-fault",
	"tx-disable",
	"rate-select0",
};

static const enum gpiod_flags gpio_flags[] = {
	GPIOD_IN,
	GPIOD_IN,
	GPIOD_IN,
	GPIOD_ASIS,
	GPIOD_ASIS,
};

/* t_start_up (SFF-8431) or t_init (SFF-8472) is the time required for a
 * non-cooled module to initialise its laser safety circuitry. We wait
 * an initial T_WAIT period before we check the tx fault to give any PHY
 * on board (for a copper SFP) time to initialise.
 */
#define T_WAIT			msecs_to_jiffies(50)
#define T_START_UP		msecs_to_jiffies(300)
#define T_START_UP_BAD_GPON	msecs_to_jiffies(60000)

/* t_reset is the time required to assert the TX_DISABLE signal to reset
 * an indicated TX_FAULT.
 */
#define T_RESET_US		10
#define T_FAULT_RECOVER		msecs_to_jiffies(1000)

/* N_FAULT_INIT is the number of recovery attempts at module initialisation
 * time. If the TX_FAULT signal is not deasserted after this number of
 * attempts at clearing it, we decide that the module is faulty.
 * N_FAULT is the same but after the module has initialised.
 */
#define N_FAULT_INIT		5
#define N_FAULT			5

/* T_PHY_RETRY is the time interval between attempts to probe the PHY.
 * R_PHY_RETRY is the number of attempts.
 */
#define T_PHY_RETRY		msecs_to_jiffies(50)
#define R_PHY_RETRY		12

/* SFP module presence detection is poor: the three MOD DEF signals are
 * the same length on the PCB, which means it's possible for MOD DEF 0 to
 * connect before the I2C bus on MOD DEF 1/2.
 *
 * The SFF-8472 specifies t_serial ("Time from power on until module is
 * ready for data transmission over the two wire serial bus.") as 300ms.
 */
#define T_SERIAL		msecs_to_jiffies(300)
#define T_HPOWER_LEVEL		msecs_to_jiffies(300)
#define T_PROBE_RETRY_INIT	msecs_to_jiffies(100)
#define R_PROBE_RETRY_INIT	10
#define T_PROBE_RETRY_SLOW	msecs_to_jiffies(5000)
#define R_PROBE_RETRY_SLOW	12

/* SFP modules appear to always have their PHY configured for bus address
 * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
 */
#define SFP_PHY_ADDR	22

struct sff_data {
	unsigned int gpios;
	bool (*module_supported)(const struct sfp_eeprom_id *id);
};

struct sfp {
	struct device *dev;
	struct i2c_adapter *i2c;
	struct mii_bus *i2c_mii;
	struct sfp_bus *sfp_bus;
	struct phy_device *mod_phy;
	const struct sff_data *type;
	size_t i2c_block_size;
	u32 max_power_mW;

	unsigned int (*get_state)(struct sfp *);
	void (*set_state)(struct sfp *, unsigned int);
	int (*read)(struct sfp *, bool, u8, void *, size_t);
	int (*write)(struct sfp *, bool, u8, void *, size_t);

	struct gpio_desc *gpio[GPIO_MAX];
	int gpio_irq[GPIO_MAX];

	bool need_poll;

	struct mutex st_mutex;			/* Protects state */
	unsigned int state_soft_mask;
	unsigned int state;
	struct delayed_work poll;
	struct delayed_work timeout;
	struct mutex sm_mutex;			/* Protects state machine */
	unsigned char sm_mod_state;
	unsigned char sm_mod_tries_init;
	unsigned char sm_mod_tries;
	unsigned char sm_dev_state;
	unsigned short sm_state;
	unsigned char sm_fault_retries;
	unsigned char sm_phy_retries;

	struct sfp_eeprom_id id;
	unsigned int module_power_mW;
	unsigned int module_t_start_up;

#if IS_ENABLED(CONFIG_HWMON)
	struct sfp_diag diag;
	struct delayed_work hwmon_probe;
	unsigned int hwmon_tries;
	struct device *hwmon_dev;
	char *hwmon_name;
#endif

#if IS_ENABLED(CONFIG_DEBUG_FS)
	struct dentry *debugfs_dir;
#endif
};

static bool sff_module_supported(const struct sfp_eeprom_id *id)
{
	return id->base.phys_id == SFF8024_ID_SFF_8472 &&
	       id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
}

static const struct sff_data sff_data = {
	.gpios = SFP_F_LOS | SFP_F_TX_FAULT | SFP_F_TX_DISABLE,
	.module_supported = sff_module_supported,
};

static bool sfp_module_supported(const struct sfp_eeprom_id *id)
{
	if (id->base.phys_id == SFF8024_ID_SFP &&
	    id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP)
		return true;

	/* SFP GPON module Ubiquiti U-Fiber Instant has in its EEPROM stored
	 * phys id SFF instead of SFP. Therefore mark this module explicitly
	 * as supported based on vendor name and pn match.
	 */
	if (id->base.phys_id == SFF8024_ID_SFF_8472 &&
	    id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP &&
	    !memcmp(id->base.vendor_name, "UBNT            ", 16) &&
	    !memcmp(id->base.vendor_pn, "UF-INSTANT      ", 16))
		return true;

	return false;
}

static const struct sff_data sfp_data = {
	.gpios = SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT |
		 SFP_F_TX_DISABLE | SFP_F_RATE_SELECT,
	.module_supported = sfp_module_supported,
};

static const struct of_device_id sfp_of_match[] = {
	{ .compatible = "sff,sff", .data = &sff_data, },
	{ .compatible = "sff,sfp", .data = &sfp_data, },
	{ },
};
MODULE_DEVICE_TABLE(of, sfp_of_match);

static unsigned long poll_jiffies;

static unsigned int sfp_gpio_get_state(struct sfp *sfp)
{
	unsigned int i, state, v;

	for (i = state = 0; i < GPIO_MAX; i++) {
		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
			continue;

		v = gpiod_get_value_cansleep(sfp->gpio[i]);
		if (v)
			state |= BIT(i);
	}

	return state;
}

static unsigned int sff_gpio_get_state(struct sfp *sfp)
{
	return sfp_gpio_get_state(sfp) | SFP_F_PRESENT;
}

static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
{
	if (state & SFP_F_PRESENT) {
		/* If the module is present, drive the signals */
		if (sfp->gpio[GPIO_TX_DISABLE])
			gpiod_direction_output(sfp->gpio[GPIO_TX_DISABLE],
					       state & SFP_F_TX_DISABLE);
		if (state & SFP_F_RATE_SELECT)
			gpiod_direction_output(sfp->gpio[GPIO_RATE_SELECT],
					       state & SFP_F_RATE_SELECT);
	} else {
		/* Otherwise, let them float to the pull-ups */
		if (sfp->gpio[GPIO_TX_DISABLE])
			gpiod_direction_input(sfp->gpio[GPIO_TX_DISABLE]);
		if (state & SFP_F_RATE_SELECT)
			gpiod_direction_input(sfp->gpio[GPIO_RATE_SELECT]);
	}
}

static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
			size_t len)
{
	struct i2c_msg msgs[2];
	u8 bus_addr = a2 ? 0x51 : 0x50;
	size_t block_size = sfp->i2c_block_size;
	size_t this_len;
	int ret;

	msgs[0].addr = bus_addr;
	msgs[0].flags = 0;
	msgs[0].len = 1;
	msgs[0].buf = &dev_addr;
	msgs[1].addr = bus_addr;
	msgs[1].flags = I2C_M_RD;
	msgs[1].len = len;
	msgs[1].buf = buf;

	while (len) {
		this_len = len;
		if (this_len > block_size)
			this_len = block_size;

		msgs[1].len = this_len;

		ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
		if (ret < 0)
			return ret;

		if (ret != ARRAY_SIZE(msgs))
			break;

		msgs[1].buf += this_len;
		dev_addr += this_len;
		len -= this_len;
	}

	return msgs[1].buf - (u8 *)buf;
}

static int sfp_i2c_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
	size_t len)
{
	struct i2c_msg msgs[1];
	u8 bus_addr = a2 ? 0x51 : 0x50;
	int ret;

	msgs[0].addr = bus_addr;
	msgs[0].flags = 0;
	msgs[0].len = 1 + len;
	msgs[0].buf = kmalloc(1 + len, GFP_KERNEL);
	if (!msgs[0].buf)
		return -ENOMEM;

	msgs[0].buf[0] = dev_addr;
	memcpy(&msgs[0].buf[1], buf, len);

	ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));

	kfree(msgs[0].buf);

	if (ret < 0)
		return ret;

	return ret == ARRAY_SIZE(msgs) ? len : 0;
}

static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
{
	struct mii_bus *i2c_mii;
	int ret;

	if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
		return -EINVAL;

	sfp->i2c = i2c;
	sfp->read = sfp_i2c_read;
	sfp->write = sfp_i2c_write;

	i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
	if (IS_ERR(i2c_mii))
		return PTR_ERR(i2c_mii);

	i2c_mii->name = "SFP I2C Bus";
	i2c_mii->phy_mask = ~0;

	ret = mdiobus_register(i2c_mii);
	if (ret < 0) {
		mdiobus_free(i2c_mii);
		return ret;
	}

	sfp->i2c_mii = i2c_mii;

	return 0;
}

/* Interface */
static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
{
	return sfp->read(sfp, a2, addr, buf, len);
}

static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
{
	return sfp->write(sfp, a2, addr, buf, len);
}

static unsigned int sfp_soft_get_state(struct sfp *sfp)
{
	unsigned int state = 0;
	u8 status;
	int ret;

	ret = sfp_read(sfp, true, SFP_STATUS, &status, sizeof(status));
	if (ret == sizeof(status)) {
		if (status & SFP_STATUS_RX_LOS)
			state |= SFP_F_LOS;
		if (status & SFP_STATUS_TX_FAULT)
			state |= SFP_F_TX_FAULT;
	} else {
		dev_err_ratelimited(sfp->dev,
				    "failed to read SFP soft status: %d\n",
				    ret);
		/* Preserve the current state */
		state = sfp->state;
	}

	return state & sfp->state_soft_mask;
}

static void sfp_soft_set_state(struct sfp *sfp, unsigned int state)
{
	u8 status;

	if (sfp_read(sfp, true, SFP_STATUS, &status, sizeof(status)) ==
		     sizeof(status)) {
		if (state & SFP_F_TX_DISABLE)
			status |= SFP_STATUS_TX_DISABLE_FORCE;
		else
			status &= ~SFP_STATUS_TX_DISABLE_FORCE;

		sfp_write(sfp, true, SFP_STATUS, &status, sizeof(status));
	}
}

static void sfp_soft_start_poll(struct sfp *sfp)
{
	const struct sfp_eeprom_id *id = &sfp->id;

	sfp->state_soft_mask = 0;
	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_DISABLE &&
	    !sfp->gpio[GPIO_TX_DISABLE])
		sfp->state_soft_mask |= SFP_F_TX_DISABLE;
	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_FAULT &&
	    !sfp->gpio[GPIO_TX_FAULT])
		sfp->state_soft_mask |= SFP_F_TX_FAULT;
	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_RX_LOS &&
	    !sfp->gpio[GPIO_LOS])
		sfp->state_soft_mask |= SFP_F_LOS;

	if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) &&
	    !sfp->need_poll)
		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
}

static void sfp_soft_stop_poll(struct sfp *sfp)
{
	sfp->state_soft_mask = 0;
}

static unsigned int sfp_get_state(struct sfp *sfp)
{
	unsigned int state = sfp->get_state(sfp);

	if (state & SFP_F_PRESENT &&
	    sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT))
		state |= sfp_soft_get_state(sfp);

	return state;
}

static void sfp_set_state(struct sfp *sfp, unsigned int state)
{
	sfp->set_state(sfp, state);

	if (state & SFP_F_PRESENT &&
	    sfp->state_soft_mask & SFP_F_TX_DISABLE)
		sfp_soft_set_state(sfp, state);
}

static unsigned int sfp_check(void *buf, size_t len)
{
	u8 *p, check;

	for (p = buf, check = 0; len; p++, len--)
		check += *p;

	return check;
}

/* hwmon */
#if IS_ENABLED(CONFIG_HWMON)
static umode_t sfp_hwmon_is_visible(const void *data,
				    enum hwmon_sensor_types type,
				    u32 attr, int channel)
{
	const struct sfp *sfp = data;

	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_min_alarm:
		case hwmon_temp_max_alarm:
		case hwmon_temp_lcrit_alarm:
		case hwmon_temp_crit_alarm:
		case hwmon_temp_min:
		case hwmon_temp_max:
		case hwmon_temp_lcrit:
		case hwmon_temp_crit:
			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
				return 0;
			fallthrough;
		case hwmon_temp_input:
		case hwmon_temp_label:
			return 0444;
		default:
			return 0;
		}
	case hwmon_in:
		switch (attr) {
		case hwmon_in_min_alarm:
		case hwmon_in_max_alarm:
		case hwmon_in_lcrit_alarm:
		case hwmon_in_crit_alarm:
		case hwmon_in_min:
		case hwmon_in_max:
		case hwmon_in_lcrit:
		case hwmon_in_crit:
			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
				return 0;
			fallthrough;
		case hwmon_in_input:
		case hwmon_in_label:
			return 0444;
		default:
			return 0;
		}
	case hwmon_curr:
		switch (attr) {
		case hwmon_curr_min_alarm:
		case hwmon_curr_max_alarm:
		case hwmon_curr_lcrit_alarm:
		case hwmon_curr_crit_alarm:
		case hwmon_curr_min:
		case hwmon_curr_max:
		case hwmon_curr_lcrit:
		case hwmon_curr_crit:
			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
				return 0;
			fallthrough;
		case hwmon_curr_input:
		case hwmon_curr_label:
			return 0444;
		default:
			return 0;
		}
	case hwmon_power:
		/* External calibration of receive power requires
		 * floating point arithmetic. Doing that in the kernel
		 * is not easy, so just skip it. If the module does
		 * not require external calibration, we can however
		 * show receiver power, since FP is then not needed.
		 */
		if (sfp->id.ext.diagmon & SFP_DIAGMON_EXT_CAL &&
		    channel == 1)
			return 0;
		switch (attr) {
		case hwmon_power_min_alarm:
		case hwmon_power_max_alarm:
		case hwmon_power_lcrit_alarm:
		case hwmon_power_crit_alarm:
		case hwmon_power_min:
		case hwmon_power_max:
		case hwmon_power_lcrit:
		case hwmon_power_crit:
			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
				return 0;
			fallthrough;
		case hwmon_power_input:
		case hwmon_power_label:
			return 0444;
		default:
			return 0;
		}
	default:
		return 0;
	}
}

static int sfp_hwmon_read_sensor(struct sfp *sfp, int reg, long *value)
{
	__be16 val;
	int err;

	err = sfp_read(sfp, true, reg, &val, sizeof(val));
	if (err < 0)
		return err;

	*value = be16_to_cpu(val);

	return 0;
}

static void sfp_hwmon_to_rx_power(long *value)
{
	*value = DIV_ROUND_CLOSEST(*value, 10);
}

static void sfp_hwmon_calibrate(struct sfp *sfp, unsigned int slope, int offset,
				long *value)
{
	if (sfp->id.ext.diagmon & SFP_DIAGMON_EXT_CAL)
		*value = DIV_ROUND_CLOSEST(*value * slope, 256) + offset;
}

static void sfp_hwmon_calibrate_temp(struct sfp *sfp, long *value)
{
	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_t_slope),
			    be16_to_cpu(sfp->diag.cal_t_offset), value);

	if (*value >= 0x8000)
		*value -= 0x10000;

	*value = DIV_ROUND_CLOSEST(*value * 1000, 256);
}

static void sfp_hwmon_calibrate_vcc(struct sfp *sfp, long *value)
{
	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_v_slope),
			    be16_to_cpu(sfp->diag.cal_v_offset), value);

	*value = DIV_ROUND_CLOSEST(*value, 10);
}

static void sfp_hwmon_calibrate_bias(struct sfp *sfp, long *value)
{
	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_txi_slope),
			    be16_to_cpu(sfp->diag.cal_txi_offset), value);

	*value = DIV_ROUND_CLOSEST(*value, 500);
}

static void sfp_hwmon_calibrate_tx_power(struct sfp *sfp, long *value)
{
	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_txpwr_slope),
			    be16_to_cpu(sfp->diag.cal_txpwr_offset), value);

	*value = DIV_ROUND_CLOSEST(*value, 10);
}

static int sfp_hwmon_read_temp(struct sfp *sfp, int reg, long *value)
{
	int err;

	err = sfp_hwmon_read_sensor(sfp, reg, value);
	if (err < 0)
		return err;

	sfp_hwmon_calibrate_temp(sfp, value);

	return 0;
}

static int sfp_hwmon_read_vcc(struct sfp *sfp, int reg, long *value)
{
	int err;

	err = sfp_hwmon_read_sensor(sfp, reg, value);
	if (err < 0)
		return err;

	sfp_hwmon_calibrate_vcc(sfp, value);

	return 0;
}

static int sfp_hwmon_read_bias(struct sfp *sfp, int reg, long *value)
{
	int err;

	err = sfp_hwmon_read_sensor(sfp, reg, value);
	if (err < 0)
		return err;

	sfp_hwmon_calibrate_bias(sfp, value);

	return 0;
}

static int sfp_hwmon_read_tx_power(struct sfp *sfp, int reg, long *value)
{
	int err;

	err = sfp_hwmon_read_sensor(sfp, reg, value);
	if (err < 0)
		return err;

	sfp_hwmon_calibrate_tx_power(sfp, value);

	return 0;
}

static int sfp_hwmon_read_rx_power(struct sfp *sfp, int reg, long *value)
{
	int err;

	err = sfp_hwmon_read_sensor(sfp, reg, value);
	if (err < 0)
		return err;

	sfp_hwmon_to_rx_power(value);

	return 0;
}

static int sfp_hwmon_temp(struct sfp *sfp, u32 attr, long *value)
{
	u8 status;
	int err;

	switch (attr) {
	case hwmon_temp_input:
		return sfp_hwmon_read_temp(sfp, SFP_TEMP, value);

	case hwmon_temp_lcrit:
		*value = be16_to_cpu(sfp->diag.temp_low_alarm);
		sfp_hwmon_calibrate_temp(sfp, value);
		return 0;

	case hwmon_temp_min:
		*value = be16_to_cpu(sfp->diag.temp_low_warn);
		sfp_hwmon_calibrate_temp(sfp, value);
		return 0;
	case hwmon_temp_max:
		*value = be16_to_cpu(sfp->diag.temp_high_warn);
		sfp_hwmon_calibrate_temp(sfp, value);
		return 0;

	case hwmon_temp_crit:
		*value = be16_to_cpu(sfp->diag.temp_high_alarm);
		sfp_hwmon_calibrate_temp(sfp, value);
		return 0;

	case hwmon_temp_lcrit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TEMP_LOW);
		return 0;

	case hwmon_temp_min_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TEMP_LOW);
		return 0;

	case hwmon_temp_max_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TEMP_HIGH);
		return 0;

	case hwmon_temp_crit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TEMP_HIGH);
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static int sfp_hwmon_vcc(struct sfp *sfp, u32 attr, long *value)
{
	u8 status;
	int err;

	switch (attr) {
	case hwmon_in_input:
		return sfp_hwmon_read_vcc(sfp, SFP_VCC, value);

	case hwmon_in_lcrit:
		*value = be16_to_cpu(sfp->diag.volt_low_alarm);
		sfp_hwmon_calibrate_vcc(sfp, value);
		return 0;

	case hwmon_in_min:
		*value = be16_to_cpu(sfp->diag.volt_low_warn);
		sfp_hwmon_calibrate_vcc(sfp, value);
		return 0;

	case hwmon_in_max:
		*value = be16_to_cpu(sfp->diag.volt_high_warn);
		sfp_hwmon_calibrate_vcc(sfp, value);
		return 0;

	case hwmon_in_crit:
		*value = be16_to_cpu(sfp->diag.volt_high_alarm);
		sfp_hwmon_calibrate_vcc(sfp, value);
		return 0;

	case hwmon_in_lcrit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_VCC_LOW);
		return 0;

	case hwmon_in_min_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_VCC_LOW);
		return 0;

	case hwmon_in_max_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_VCC_HIGH);
		return 0;

	case hwmon_in_crit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_VCC_HIGH);
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static int sfp_hwmon_bias(struct sfp *sfp, u32 attr, long *value)
{
	u8 status;
	int err;

	switch (attr) {
	case hwmon_curr_input:
		return sfp_hwmon_read_bias(sfp, SFP_TX_BIAS, value);

	case hwmon_curr_lcrit:
		*value = be16_to_cpu(sfp->diag.bias_low_alarm);
		sfp_hwmon_calibrate_bias(sfp, value);
		return 0;

	case hwmon_curr_min:
		*value = be16_to_cpu(sfp->diag.bias_low_warn);
		sfp_hwmon_calibrate_bias(sfp, value);
		return 0;

	case hwmon_curr_max:
		*value = be16_to_cpu(sfp->diag.bias_high_warn);
		sfp_hwmon_calibrate_bias(sfp, value);
		return 0;

	case hwmon_curr_crit:
		*value = be16_to_cpu(sfp->diag.bias_high_alarm);
		sfp_hwmon_calibrate_bias(sfp, value);
		return 0;

	case hwmon_curr_lcrit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TX_BIAS_LOW);
		return 0;

	case hwmon_curr_min_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TX_BIAS_LOW);
		return 0;

	case hwmon_curr_max_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TX_BIAS_HIGH);
		return 0;

	case hwmon_curr_crit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TX_BIAS_HIGH);
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static int sfp_hwmon_tx_power(struct sfp *sfp, u32 attr, long *value)
{
	u8 status;
	int err;

	switch (attr) {
	case hwmon_power_input:
		return sfp_hwmon_read_tx_power(sfp, SFP_TX_POWER, value);

	case hwmon_power_lcrit:
		*value = be16_to_cpu(sfp->diag.txpwr_low_alarm);
		sfp_hwmon_calibrate_tx_power(sfp, value);
		return 0;

	case hwmon_power_min:
		*value = be16_to_cpu(sfp->diag.txpwr_low_warn);
		sfp_hwmon_calibrate_tx_power(sfp, value);
		return 0;

	case hwmon_power_max:
		*value = be16_to_cpu(sfp->diag.txpwr_high_warn);
		sfp_hwmon_calibrate_tx_power(sfp, value);
		return 0;

	case hwmon_power_crit:
		*value = be16_to_cpu(sfp->diag.txpwr_high_alarm);
		sfp_hwmon_calibrate_tx_power(sfp, value);
		return 0;

	case hwmon_power_lcrit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TXPWR_LOW);
		return 0;

	case hwmon_power_min_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TXPWR_LOW);
		return 0;

	case hwmon_power_max_alarm:
		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN0_TXPWR_HIGH);
		return 0;

	case hwmon_power_crit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM0_TXPWR_HIGH);
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static int sfp_hwmon_rx_power(struct sfp *sfp, u32 attr, long *value)
{
	u8 status;
	int err;

	switch (attr) {
	case hwmon_power_input:
		return sfp_hwmon_read_rx_power(sfp, SFP_RX_POWER, value);

	case hwmon_power_lcrit:
		*value = be16_to_cpu(sfp->diag.rxpwr_low_alarm);
		sfp_hwmon_to_rx_power(value);
		return 0;

	case hwmon_power_min:
		*value = be16_to_cpu(sfp->diag.rxpwr_low_warn);
		sfp_hwmon_to_rx_power(value);
		return 0;

	case hwmon_power_max:
		*value = be16_to_cpu(sfp->diag.rxpwr_high_warn);
		sfp_hwmon_to_rx_power(value);
		return 0;

	case hwmon_power_crit:
		*value = be16_to_cpu(sfp->diag.rxpwr_high_alarm);
		sfp_hwmon_to_rx_power(value);
		return 0;

	case hwmon_power_lcrit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM1, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM1_RXPWR_LOW);
		return 0;

	case hwmon_power_min_alarm:
		err = sfp_read(sfp, true, SFP_WARN1, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN1_RXPWR_LOW);
		return 0;

	case hwmon_power_max_alarm:
		err = sfp_read(sfp, true, SFP_WARN1, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_WARN1_RXPWR_HIGH);
		return 0;

	case hwmon_power_crit_alarm:
		err = sfp_read(sfp, true, SFP_ALARM1, &status, sizeof(status));
		if (err < 0)
			return err;

		*value = !!(status & SFP_ALARM1_RXPWR_HIGH);
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static int sfp_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
			  u32 attr, int channel, long *value)
{
	struct sfp *sfp = dev_get_drvdata(dev);

	switch (type) {
	case hwmon_temp:
		return sfp_hwmon_temp(sfp, attr, value);
	case hwmon_in:
		return sfp_hwmon_vcc(sfp, attr, value);
	case hwmon_curr:
		return sfp_hwmon_bias(sfp, attr, value);
	case hwmon_power:
		switch (channel) {
		case 0:
			return sfp_hwmon_tx_power(sfp, attr, value);
		case 1:
			return sfp_hwmon_rx_power(sfp, attr, value);
		default:
			return -EOPNOTSUPP;
		}
	default:
		return -EOPNOTSUPP;
	}
}

static const char *const sfp_hwmon_power_labels[] = {
	"TX_power",
	"RX_power",
};

static int sfp_hwmon_read_string(struct device *dev,
				 enum hwmon_sensor_types type,
				 u32 attr, int channel, const char **str)
{
	switch (type) {
	case hwmon_curr:
		switch (attr) {
		case hwmon_curr_label:
			*str = "bias";
			return 0;
		default:
			return -EOPNOTSUPP;
		}
		break;
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_label:
			*str = "temperature";
			return 0;
		default:
			return -EOPNOTSUPP;
		}
		break;
	case hwmon_in:
		switch (attr) {
		case hwmon_in_label:
			*str = "VCC";
			return 0;
		default:
			return -EOPNOTSUPP;
		}
		break;
	case hwmon_power:
		switch (attr) {
		case hwmon_power_label:
			*str = sfp_hwmon_power_labels[channel];
			return 0;
		default:
			return -EOPNOTSUPP;
		}
		break;
	default:
		return -EOPNOTSUPP;
	}

	return -EOPNOTSUPP;
}

static const struct hwmon_ops sfp_hwmon_ops = {
	.is_visible = sfp_hwmon_is_visible,
	.read = sfp_hwmon_read,
	.read_string = sfp_hwmon_read_string,
};

static u32 sfp_hwmon_chip_config[] = {
	HWMON_C_REGISTER_TZ,
	0,
};

static const struct hwmon_channel_info sfp_hwmon_chip = {
	.type = hwmon_chip,
	.config = sfp_hwmon_chip_config,
};

static u32 sfp_hwmon_temp_config[] = {
	HWMON_T_INPUT |
	HWMON_T_MAX | HWMON_T_MIN |
	HWMON_T_MAX_ALARM | HWMON_T_MIN_ALARM |
	HWMON_T_CRIT | HWMON_T_LCRIT |
	HWMON_T_CRIT_ALARM | HWMON_T_LCRIT_ALARM |
	HWMON_T_LABEL,
	0,
};

static const struct hwmon_channel_info sfp_hwmon_temp_channel_info = {
	.type = hwmon_temp,
	.config = sfp_hwmon_temp_config,
};

static u32 sfp_hwmon_vcc_config[] = {
	HWMON_I_INPUT |
	HWMON_I_MAX | HWMON_I_MIN |
	HWMON_I_MAX_ALARM | HWMON_I_MIN_ALARM |
	HWMON_I_CRIT | HWMON_I_LCRIT |
	HWMON_I_CRIT_ALARM | HWMON_I_LCRIT_ALARM |
	HWMON_I_LABEL,
	0,
};

static const struct hwmon_channel_info sfp_hwmon_vcc_channel_info = {
	.type = hwmon_in,
	.config = sfp_hwmon_vcc_config,
};

static u32 sfp_hwmon_bias_config[] = {
	HWMON_C_INPUT |
	HWMON_C_MAX | HWMON_C_MIN |
	HWMON_C_MAX_ALARM | HWMON_C_MIN_ALARM |
	HWMON_C_CRIT | HWMON_C_LCRIT |
	HWMON_C_CRIT_ALARM | HWMON_C_LCRIT_ALARM |
	HWMON_C_LABEL,
	0,
};

static const struct hwmon_channel_info sfp_hwmon_bias_channel_info = {
	.type = hwmon_curr,
	.config = sfp_hwmon_bias_config,
};

static u32 sfp_hwmon_power_config[] = {
	/* Transmit power */
	HWMON_P_INPUT |
	HWMON_P_MAX | HWMON_P_MIN |
	HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
	HWMON_P_CRIT | HWMON_P_LCRIT |
	HWMON_P_CRIT_ALARM | HWMON_P_LCRIT_ALARM |
	HWMON_P_LABEL,
	/* Receive power */
	HWMON_P_INPUT |
	HWMON_P_MAX | HWMON_P_MIN |
	HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
	HWMON_P_CRIT | HWMON_P_LCRIT |
	HWMON_P_CRIT_ALARM | HWMON_P_LCRIT_ALARM |
	HWMON_P_LABEL,
	0,
};

static const struct hwmon_channel_info sfp_hwmon_power_channel_info = {
	.type = hwmon_power,
	.config = sfp_hwmon_power_config,
};

static const struct hwmon_channel_info *sfp_hwmon_info[] = {
	&sfp_hwmon_chip,
	&sfp_hwmon_vcc_channel_info,
	&sfp_hwmon_temp_channel_info,
	&sfp_hwmon_bias_channel_info,
	&sfp_hwmon_power_channel_info,
	NULL,
};

static const struct hwmon_chip_info sfp_hwmon_chip_info = {
	.ops = &sfp_hwmon_ops,
	.info = sfp_hwmon_info,
};

static void sfp_hwmon_probe(struct work_struct *work)
{
	struct sfp *sfp = container_of(work, struct sfp, hwmon_probe.work);
	int err, i;

	/* hwmon interface needs to access 16bit registers in atomic way to
	 * guarantee coherency of the diagnostic monitoring data. If it is not
	 * possible to guarantee coherency because EEPROM is broken in such way
	 * that does not support atomic 16bit read operation then we have to
	 * skip registration of hwmon device.
	 */
	if (sfp->i2c_block_size < 2) {
		dev_info(sfp->dev,
			 "skipping hwmon device registration due to broken EEPROM\n");
		dev_info(sfp->dev,
			 "diagnostic EEPROM area cannot be read atomically to guarantee data coherency\n");
		return;
	}

	err = sfp_read(sfp, true, 0, &sfp->diag, sizeof(sfp->diag));
	if (err < 0) {
		if (sfp->hwmon_tries--) {
			mod_delayed_work(system_wq, &sfp->hwmon_probe,
					 T_PROBE_RETRY_SLOW);
		} else {
			dev_warn(sfp->dev, "hwmon probe failed: %d\n", err);
		}
		return;
	}

	sfp->hwmon_name = kstrdup(dev_name(sfp->dev), GFP_KERNEL);
	if (!sfp->hwmon_name) {
		dev_err(sfp->dev, "out of memory for hwmon name\n");
		return;
	}

	for (i = 0; sfp->hwmon_name[i]; i++)
		if (hwmon_is_bad_char(sfp->hwmon_name[i]))
			sfp->hwmon_name[i] = '_';

	sfp->hwmon_dev = hwmon_device_register_with_info(sfp->dev,
							 sfp->hwmon_name, sfp,
							 &sfp_hwmon_chip_info,
							 NULL);
	if (IS_ERR(sfp->hwmon_dev))
		dev_err(sfp->dev, "failed to register hwmon device: %ld\n",
			PTR_ERR(sfp->hwmon_dev));
}

static int sfp_hwmon_insert(struct sfp *sfp)
{
	if (sfp->id.ext.sff8472_compliance == SFP_SFF8472_COMPLIANCE_NONE)
		return 0;

	if (!(sfp->id.ext.diagmon & SFP_DIAGMON_DDM))
		return 0;

	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
		/* This driver in general does not support address
		 * change.
		 */
		return 0;

	mod_delayed_work(system_wq, &sfp->hwmon_probe, 1);
	sfp->hwmon_tries = R_PROBE_RETRY_SLOW;

	return 0;
}

static void sfp_hwmon_remove(struct sfp *sfp)
{
	cancel_delayed_work_sync(&sfp->hwmon_probe);
	if (!IS_ERR_OR_NULL(sfp->hwmon_dev)) {
		hwmon_device_unregister(sfp->hwmon_dev);
		sfp->hwmon_dev = NULL;
		kfree(sfp->hwmon_name);
	}
}

static int sfp_hwmon_init(struct sfp *sfp)
{
	INIT_DELAYED_WORK(&sfp->hwmon_probe, sfp_hwmon_probe);

	return 0;
}

static void sfp_hwmon_exit(struct sfp *sfp)
{
	cancel_delayed_work_sync(&sfp->hwmon_probe);
}
#else
static int sfp_hwmon_insert(struct sfp *sfp)
{
	return 0;
}

static void sfp_hwmon_remove(struct sfp *sfp)
{
}

static int sfp_hwmon_init(struct sfp *sfp)
{
	return 0;
}

static void sfp_hwmon_exit(struct sfp *sfp)
{
}
#endif

/* Helpers */
static void sfp_module_tx_disable(struct sfp *sfp)
{
	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 1);
	sfp->state |= SFP_F_TX_DISABLE;
	sfp_set_state(sfp, sfp->state);
}

static void sfp_module_tx_enable(struct sfp *sfp)
{
	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 0);
	sfp->state &= ~SFP_F_TX_DISABLE;
	sfp_set_state(sfp, sfp->state);
}

#if IS_ENABLED(CONFIG_DEBUG_FS)
static int sfp_debug_state_show(struct seq_file *s, void *data)
{
	struct sfp *sfp = s->private;

	seq_printf(s, "Module state: %s\n",
		   mod_state_to_str(sfp->sm_mod_state));
	seq_printf(s, "Module probe attempts: %d %d\n",
		   R_PROBE_RETRY_INIT - sfp->sm_mod_tries_init,
		   R_PROBE_RETRY_SLOW - sfp->sm_mod_tries);
	seq_printf(s, "Device state: %s\n",
		   dev_state_to_str(sfp->sm_dev_state));
	seq_printf(s, "Main state: %s\n",
		   sm_state_to_str(sfp->sm_state));
	seq_printf(s, "Fault recovery remaining retries: %d\n",
		   sfp->sm_fault_retries);
	seq_printf(s, "PHY probe remaining retries: %d\n",
		   sfp->sm_phy_retries);
	seq_printf(s, "moddef0: %d\n", !!(sfp->state & SFP_F_PRESENT));
	seq_printf(s, "rx_los: %d\n", !!(sfp->state & SFP_F_LOS));
	seq_printf(s, "tx_fault: %d\n", !!(sfp->state & SFP_F_TX_FAULT));
	seq_printf(s, "tx_disable: %d\n", !!(sfp->state & SFP_F_TX_DISABLE));
	return 0;
}
DEFINE_SHOW_ATTRIBUTE(sfp_debug_state);

static void sfp_debugfs_init(struct sfp *sfp)
{
	sfp->debugfs_dir = debugfs_create_dir(dev_name(sfp->dev), NULL);

	debugfs_create_file("state", 0600, sfp->debugfs_dir, sfp,
			    &sfp_debug_state_fops);
}

static void sfp_debugfs_exit(struct sfp *sfp)
{
	debugfs_remove_recursive(sfp->debugfs_dir);
}
#else
static void sfp_debugfs_init(struct sfp *sfp)
{
}

static void sfp_debugfs_exit(struct sfp *sfp)
{
}
#endif

static void sfp_module_tx_fault_reset(struct sfp *sfp)
{
	unsigned int state = sfp->state;

	if (state & SFP_F_TX_DISABLE)
		return;

	sfp_set_state(sfp, state | SFP_F_TX_DISABLE);

	udelay(T_RESET_US);

	sfp_set_state(sfp, state);
}

/* SFP state machine */
static void sfp_sm_set_timer(struct sfp *sfp, unsigned int timeout)
{
	if (timeout)
		mod_delayed_work(system_power_efficient_wq, &sfp->timeout,
				 timeout);
	else
		cancel_delayed_work(&sfp->timeout);
}

static void sfp_sm_next(struct sfp *sfp, unsigned int state,
			unsigned int timeout)
{
	sfp->sm_state = state;
	sfp_sm_set_timer(sfp, timeout);
}

static void sfp_sm_mod_next(struct sfp *sfp, unsigned int state,
			    unsigned int timeout)
{
	sfp->sm_mod_state = state;
	sfp_sm_set_timer(sfp, timeout);
}

static void sfp_sm_phy_detach(struct sfp *sfp)
{
	sfp_remove_phy(sfp->sfp_bus);
	phy_device_remove(sfp->mod_phy);
	phy_device_free(sfp->mod_phy);
	sfp->mod_phy = NULL;
}

static int sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
{
	struct phy_device *phy;
	int err;

	phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
	if (phy == ERR_PTR(-ENODEV))
		return PTR_ERR(phy);
	if (IS_ERR(phy)) {
		dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
		return PTR_ERR(phy);
	}

	err = phy_device_register(phy);
	if (err) {
		phy_device_free(phy);
		dev_err(sfp->dev, "phy_device_register failed: %d\n", err);
		return err;
	}

	err = sfp_add_phy(sfp->sfp_bus, phy);
	if (err) {
		phy_device_remove(phy);
		phy_device_free(phy);
		dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
		return err;
	}

	sfp->mod_phy = phy;

	return 0;
}

static void sfp_sm_link_up(struct sfp *sfp)
{
	sfp_link_up(sfp->sfp_bus);
	sfp_sm_next(sfp, SFP_S_LINK_UP, 0);
}

static void sfp_sm_link_down(struct sfp *sfp)
{
	sfp_link_down(sfp->sfp_bus);
}

static void sfp_sm_link_check_los(struct sfp *sfp)
{
	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);
	bool los = false;

	/* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL
	 * are set, we assume that no LOS signal is available. If both are
	 * set, we assume LOS is not implemented (and is meaningless.)
	 */
	if (los_options == los_inverted)
		los = !(sfp->state & SFP_F_LOS);
	else if (los_options == los_normal)
		los = !!(sfp->state & SFP_F_LOS);

	if (los)
		sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
	else
		sfp_sm_link_up(sfp);
}

static bool sfp_los_event_active(struct sfp *sfp, unsigned int event)
{
	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);

	return (los_options == los_inverted && event == SFP_E_LOS_LOW) ||
	       (los_options == los_normal && event == SFP_E_LOS_HIGH);
}

static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event)
{
	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);

	return (los_options == los_inverted && event == SFP_E_LOS_HIGH) ||
	       (los_options == los_normal && event == SFP_E_LOS_LOW);
}

static void sfp_sm_fault(struct sfp *sfp, unsigned int next_state, bool warn)
{
	if (sfp->sm_fault_retries && !--sfp->sm_fault_retries) {
		dev_err(sfp->dev,
			"module persistently indicates fault, disabling\n");
		sfp_sm_next(sfp, SFP_S_TX_DISABLE, 0);
	} else {
		if (warn)
			dev_err(sfp->dev, "module transmit fault indicated\n");

		sfp_sm_next(sfp, next_state, T_FAULT_RECOVER);
	}
}

/* Probe a SFP for a PHY device if the module supports copper - the PHY
 * normally sits at I2C bus address 0x56, and may either be a clause 22
 * or clause 45 PHY.
 *
 * Clause 22 copper SFP modules normally operate in Cisco SGMII mode with
 * negotiation enabled, but some may be in 1000base-X - which is for the
 * PHY driver to determine.
 *
 * Clause 45 copper SFP+ modules (10G) appear to switch their interface
 * mode according to the negotiated line speed.
 */
static int sfp_sm_probe_for_phy(struct sfp *sfp)
{
	int err = 0;

	switch (sfp->id.base.extended_cc) {
	case SFF8024_ECC_10GBASE_T_SFI:
	case SFF8024_ECC_10GBASE_T_SR:
	case SFF8024_ECC_5GBASE_T:
	case SFF8024_ECC_2_5GBASE_T:
		err = sfp_sm_probe_phy(sfp, true);
		break;

	default:
		if (sfp->id.base.e1000_base_t)
			err = sfp_sm_probe_phy(sfp, false);
		break;
	}
	return err;
}

static int sfp_module_parse_power(struct sfp *sfp)
{
	u32 power_mW = 1000;

	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
		power_mW = 1500;
	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
		power_mW = 2000;

	if (power_mW > sfp->max_power_mW) {
		/* Module power specification exceeds the allowed maximum. */
		if (sfp->id.ext.sff8472_compliance ==
			SFP_SFF8472_COMPLIANCE_NONE &&
		    !(sfp->id.ext.diagmon & SFP_DIAGMON_DDM)) {
			/* The module appears not to implement bus address
			 * 0xa2, so assume that the module powers up in the
			 * indicated mode.
			 */
			dev_err(sfp->dev,
				"Host does not support %u.%uW modules\n",
				power_mW / 1000, (power_mW / 100) % 10);
			return -EINVAL;
		} else {
			dev_warn(sfp->dev,
				 "Host does not support %u.%uW modules, module left in power mode 1\n",
				 power_mW / 1000, (power_mW / 100) % 10);
			return 0;
		}
	}

	/* If the module requires a higher power mode, but also requires
	 * an address change sequence, warn the user that the module may
	 * not be functional.
	 */
	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE && power_mW > 1000) {
		dev_warn(sfp->dev,
			 "Address Change Sequence not supported but module requires %u.%uW, module may not be functional\n",
			 power_mW / 1000, (power_mW / 100) % 10);
		return 0;
	}

	sfp->module_power_mW = power_mW;

	return 0;
}

static int sfp_sm_mod_hpower(struct sfp *sfp, bool enable)
{
	u8 val;
	int err;

	err = sfp_read(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
	if (err != sizeof(val)) {
		dev_err(sfp->dev, "Failed to read EEPROM: %d\n", err);
		return -EAGAIN;
	}

	/* DM7052 reports as a high power module, responds to reads (with
	 * all bytes 0xff) at 0x51 but does not accept writes.  In any case,
	 * if the bit is already set, we're already in high power mode.
	 */
	if (!!(val & BIT(0)) == enable)
		return 0;

	if (enable)
		val |= BIT(0);
	else
		val &= ~BIT(0);

	err = sfp_write(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
	if (err != sizeof(val)) {
		dev_err(sfp->dev, "Failed to write EEPROM: %d\n", err);
		return -EAGAIN;
	}

	if (enable)
		dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
			 sfp->module_power_mW / 1000,
			 (sfp->module_power_mW / 100) % 10);

	return 0;
}

/* GPON modules based on Realtek RTL8672 and RTL9601C chips (e.g. V-SOL
 * V2801F, CarlitoxxPro CPGOS03-0490, Ubiquiti U-Fiber Instant, ...) do
 * not support multibyte reads from the EEPROM. Each multi-byte read
 * operation returns just one byte of EEPROM followed by zeros. There is
 * no way to identify which modules are using Realtek RTL8672 and RTL9601C
 * chips. Moreover every OEM of V-SOL V2801F module puts its own vendor
 * name and vendor id into EEPROM, so there is even no way to detect if
 * module is V-SOL V2801F. Therefore check for those zeros in the read
 * data and then based on check switch to reading EEPROM to one byte
 * at a time.
 */
static bool sfp_id_needs_byte_io(struct sfp *sfp, void *buf, size_t len)
{
	size_t i, block_size = sfp->i2c_block_size;

	/* Already using byte IO */
	if (block_size == 1)
		return false;

	for (i = 1; i < len; i += block_size) {
		if (memchr_inv(buf + i, '\0', min(block_size - 1, len - i)))
			return false;
	}
	return true;
}

static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
{
	u8 check;
	int err;

	if (id->base.phys_id != SFF8024_ID_SFF_8472 ||
	    id->base.phys_ext_id != SFP_PHYS_EXT_ID_SFP ||
	    id->base.connector != SFF8024_CONNECTOR_LC) {
		dev_warn(sfp->dev, "Rewriting fiber module EEPROM with corrected values\n");
		id->base.phys_id = SFF8024_ID_SFF_8472;
		id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
		id->base.connector = SFF8024_CONNECTOR_LC;
		err = sfp_write(sfp, false, SFP_PHYS_ID, &id->base, 3);
		if (err != 3) {
			dev_err(sfp->dev, "Failed to rewrite module EEPROM: %d\n", err);
			return err;
		}

		/* Cotsworks modules have been found to require a delay between write operations. */
		mdelay(50);

		/* Update base structure checksum */
		check = sfp_check(&id->base, sizeof(id->base) - 1);
		err = sfp_write(sfp, false, SFP_CC_BASE, &check, 1);
		if (err != 1) {
			dev_err(sfp->dev, "Failed to update base structure checksum in fiber module EEPROM: %d\n", err);
			return err;
		}
	}
	return 0;
}

static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
{
	/* SFP module inserted - read I2C data */
	struct sfp_eeprom_id id;
	bool cotsworks_sfbg;
	bool cotsworks;
	u8 check;
	int ret;

	/* Some SFP modules and also some Linux I2C drivers do not like reads
	 * longer than 16 bytes, so read the EEPROM in chunks of 16 bytes at
	 * a time.
	 */
	sfp->i2c_block_size = 16;

	ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base));
	if (ret < 0) {
		if (report)
			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
		return -EAGAIN;
	}

	if (ret != sizeof(id.base)) {
		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
		return -EAGAIN;
	}

	/* Some SFP modules (e.g. Nokia 3FE46541AA) lock up if read from
	 * address 0x51 is just one byte at a time. Also SFF-8472 requires
	 * that EEPROM supports atomic 16bit read operation for diagnostic
	 * fields, so do not switch to one byte reading at a time unless it
	 * is really required and we have no other option.
	 */
	if (sfp_id_needs_byte_io(sfp, &id.base, sizeof(id.base))) {
		dev_info(sfp->dev,
			 "Detected broken RTL8672/RTL9601C emulated EEPROM\n");
		dev_info(sfp->dev,
			 "Switching to reading EEPROM to one byte at a time\n");
		sfp->i2c_block_size = 1;

		ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base));
		if (ret < 0) {
			if (report)
				dev_err(sfp->dev, "failed to read EEPROM: %d\n",
					ret);
			return -EAGAIN;
		}

		if (ret != sizeof(id.base)) {
			dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
			return -EAGAIN;
		}
	}

	/* Cotsworks do not seem to update the checksums when they
	 * do the final programming with the final module part number,
	 * serial number and date code.
	 */
	cotsworks = !memcmp(id.base.vendor_name, "COTSWORKS       ", 16);
	cotsworks_sfbg = !memcmp(id.base.vendor_pn, "SFBG", 4);

	/* Cotsworks SFF module EEPROM do not always have valid phys_id,
	 * phys_ext_id, and connector bytes.  Rewrite SFF EEPROM bytes if
	 * Cotsworks PN matches and bytes are not correct.
	 */
	if (cotsworks && cotsworks_sfbg) {
		ret = sfp_cotsworks_fixup_check(sfp, &id);
		if (ret < 0)
			return ret;
	}

	/* Validate the checksum over the base structure */
	check = sfp_check(&id.base, sizeof(id.base) - 1);
	if (check != id.base.cc_base) {
		if (cotsworks) {
			dev_warn(sfp->dev,
				 "EEPROM base structure checksum failure (0x%02x != 0x%02x)\n",
				 check, id.base.cc_base);
		} else {
			dev_err(sfp->dev,
				"EEPROM base structure checksum failure: 0x%02x != 0x%02x\n",
				check, id.base.cc_base);
			print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
				       16, 1, &id, sizeof(id), true);
			return -EINVAL;
		}
	}

	ret = sfp_read(sfp, false, SFP_CC_BASE + 1, &id.ext, sizeof(id.ext));
	if (ret < 0) {
		if (report)
			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
		return -EAGAIN;
	}

	if (ret != sizeof(id.ext)) {
		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
		return -EAGAIN;
	}

	check = sfp_check(&id.ext, sizeof(id.ext) - 1);
	if (check != id.ext.cc_ext) {
		if (cotsworks) {
			dev_warn(sfp->dev,
				 "EEPROM extended structure checksum failure (0x%02x != 0x%02x)\n",
				 check, id.ext.cc_ext);
		} else {
			dev_err(sfp->dev,
				"EEPROM extended structure checksum failure: 0x%02x != 0x%02x\n",
				check, id.ext.cc_ext);
			print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
				       16, 1, &id, sizeof(id), true);
			memset(&id.ext, 0, sizeof(id.ext));
		}
	}

	sfp->id = id;

	dev_info(sfp->dev, "module %.*s %.*s rev %.*s sn %.*s dc %.*s\n",
		 (int)sizeof(id.base.vendor_name), id.base.vendor_name,
		 (int)sizeof(id.base.vendor_pn), id.base.vendor_pn,
		 (int)sizeof(id.base.vendor_rev), id.base.vendor_rev,
		 (int)sizeof(id.ext.vendor_sn), id.ext.vendor_sn,
		 (int)sizeof(id.ext.datecode), id.ext.datecode);

	/* Check whether we support this module */
	if (!sfp->type->module_supported(&id)) {
		dev_err(sfp->dev,
			"module is not supported - phys id 0x%02x 0x%02x\n",
			sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
		return -EINVAL;
	}

	/* If the module requires address swap mode, warn about it */
	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
		dev_warn(sfp->dev,
			 "module address swap to access page 0xA2 is not supported.\n");

	/* Parse the module power requirement */
	ret = sfp_module_parse_power(sfp);
	if (ret < 0)
		return ret;

	if (!memcmp(id.base.vendor_name, "ALCATELLUCENT   ", 16) &&
	    !memcmp(id.base.vendor_pn, "3FE46541AA      ", 16))
		sfp->module_t_start_up = T_START_UP_BAD_GPON;
	else
		sfp->module_t_start_up = T_START_UP;

	return 0;
}

static void sfp_sm_mod_remove(struct sfp *sfp)
{
	if (sfp->sm_mod_state > SFP_MOD_WAITDEV)
		sfp_module_remove(sfp->sfp_bus);

	sfp_hwmon_remove(sfp);

	memset(&sfp->id, 0, sizeof(sfp->id));
	sfp->module_power_mW = 0;

	dev_info(sfp->dev, "module removed\n");
}

/* This state machine tracks the upstream's state */
static void sfp_sm_device(struct sfp *sfp, unsigned int event)
{
	switch (sfp->sm_dev_state) {
	default:
		if (event == SFP_E_DEV_ATTACH)
			sfp->sm_dev_state = SFP_DEV_DOWN;
		break;

	case SFP_DEV_DOWN:
		if (event == SFP_E_DEV_DETACH)
			sfp->sm_dev_state = SFP_DEV_DETACHED;
		else if (event == SFP_E_DEV_UP)
			sfp->sm_dev_state = SFP_DEV_UP;
		break;

	case SFP_DEV_UP:
		if (event == SFP_E_DEV_DETACH)
			sfp->sm_dev_state = SFP_DEV_DETACHED;
		else if (event == SFP_E_DEV_DOWN)
			sfp->sm_dev_state = SFP_DEV_DOWN;
		break;
	}
}

/* This state machine tracks the insert/remove state of the module, probes
 * the on-board EEPROM, and sets up the power level.
 */
static void sfp_sm_module(struct sfp *sfp, unsigned int event)
{
	int err;

	/* Handle remove event globally, it resets this state machine */
	if (event == SFP_E_REMOVE) {
		if (sfp->sm_mod_state > SFP_MOD_PROBE)
			sfp_sm_mod_remove(sfp);
		sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
		return;
	}

	/* Handle device detach globally */
	if (sfp->sm_dev_state < SFP_DEV_DOWN &&
	    sfp->sm_mod_state > SFP_MOD_WAITDEV) {
		if (sfp->module_power_mW > 1000 &&
		    sfp->sm_mod_state > SFP_MOD_HPOWER)
			sfp_sm_mod_hpower(sfp, false);
		sfp_sm_mod_next(sfp, SFP_MOD_WAITDEV, 0);
		return;
	}

	switch (sfp->sm_mod_state) {
	default:
		if (event == SFP_E_INSERT) {
			sfp_sm_mod_next(sfp, SFP_MOD_PROBE, T_SERIAL);
			sfp->sm_mod_tries_init = R_PROBE_RETRY_INIT;
			sfp->sm_mod_tries = R_PROBE_RETRY_SLOW;
		}
		break;

	case SFP_MOD_PROBE:
		/* Wait for T_PROBE_INIT to time out */
		if (event != SFP_E_TIMEOUT)
			break;

		err = sfp_sm_mod_probe(sfp, sfp->sm_mod_tries == 1);
		if (err == -EAGAIN) {
			if (sfp->sm_mod_tries_init &&
			   --sfp->sm_mod_tries_init) {
				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
				break;
			} else if (sfp->sm_mod_tries && --sfp->sm_mod_tries) {
				if (sfp->sm_mod_tries == R_PROBE_RETRY_SLOW - 1)
					dev_warn(sfp->dev,
						 "please wait, module slow to respond\n");
				sfp_sm_set_timer(sfp, T_PROBE_RETRY_SLOW);
				break;
			}
		}
		if (err < 0) {
			sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
			break;
		}

		err = sfp_hwmon_insert(sfp);
		if (err)
			dev_warn(sfp->dev, "hwmon probe failed: %d\n", err);

		sfp_sm_mod_next(sfp, SFP_MOD_WAITDEV, 0);
		fallthrough;
	case SFP_MOD_WAITDEV:
		/* Ensure that the device is attached before proceeding */
		if (sfp->sm_dev_state < SFP_DEV_DOWN)
			break;

		/* Report the module insertion to the upstream device */
		err = sfp_module_insert(sfp->sfp_bus, &sfp->id);
		if (err < 0) {
			sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
			break;
		}

		/* If this is a power level 1 module, we are done */
		if (sfp->module_power_mW <= 1000)
			goto insert;

		sfp_sm_mod_next(sfp, SFP_MOD_HPOWER, 0);
		fallthrough;
	case SFP_MOD_HPOWER:
		/* Enable high power mode */
		err = sfp_sm_mod_hpower(sfp, true);
		if (err < 0) {
			if (err != -EAGAIN) {
				sfp_module_remove(sfp->sfp_bus);
				sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
			} else {
				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
			}
			break;
		}

		sfp_sm_mod_next(sfp, SFP_MOD_WAITPWR, T_HPOWER_LEVEL);
		break;

	case SFP_MOD_WAITPWR:
		/* Wait for T_HPOWER_LEVEL to time out */
		if (event != SFP_E_TIMEOUT)
			break;

	insert:
		sfp_sm_mod_next(sfp, SFP_MOD_PRESENT, 0);
		break;

	case SFP_MOD_PRESENT:
	case SFP_MOD_ERROR:
		break;
	}
}

static void sfp_sm_main(struct sfp *sfp, unsigned int event)
{
	unsigned long timeout;
	int ret;

	/* Some events are global */
	if (sfp->sm_state != SFP_S_DOWN &&
	    (sfp->sm_mod_state != SFP_MOD_PRESENT ||
	     sfp->sm_dev_state != SFP_DEV_UP)) {
		if (sfp->sm_state == SFP_S_LINK_UP &&
		    sfp->sm_dev_state == SFP_DEV_UP)
			sfp_sm_link_down(sfp);
		if (sfp->sm_state > SFP_S_INIT)
			sfp_module_stop(sfp->sfp_bus);
		if (sfp->mod_phy)
			sfp_sm_phy_detach(sfp);
		sfp_module_tx_disable(sfp);
		sfp_soft_stop_poll(sfp);
		sfp_sm_next(sfp, SFP_S_DOWN, 0);
		return;
	}

	/* The main state machine */
	switch (sfp->sm_state) {
	case SFP_S_DOWN:
		if (sfp->sm_mod_state != SFP_MOD_PRESENT ||
		    sfp->sm_dev_state != SFP_DEV_UP)
			break;

		if (!(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE))
			sfp_soft_start_poll(sfp);

		sfp_module_tx_enable(sfp);

		/* Initialise the fault clearance retries */
		sfp->sm_fault_retries = N_FAULT_INIT;

		/* We need to check the TX_FAULT state, which is not defined
		 * while TX_DISABLE is asserted. The earliest we want to do
		 * anything (such as probe for a PHY) is 50ms.
		 */
		sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT);
		break;

	case SFP_S_WAIT:
		if (event != SFP_E_TIMEOUT)
			break;

		if (sfp->state & SFP_F_TX_FAULT) {
			/* Wait up to t_init (SFF-8472) or t_start_up (SFF-8431)
			 * from the TX_DISABLE deassertion for the module to
			 * initialise, which is indicated by TX_FAULT
			 * deasserting.
			 */
			timeout = sfp->module_t_start_up;
			if (timeout > T_WAIT)
				timeout -= T_WAIT;
			else
				timeout = 1;

			sfp_sm_next(sfp, SFP_S_INIT, timeout);
		} else {
			/* TX_FAULT is not asserted, assume the module has
			 * finished initialising.
			 */
			goto init_done;
		}
		break;

	case SFP_S_INIT:
		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
			/* TX_FAULT is still asserted after t_init
			 * or t_start_up, so assume there is a fault.
			 */
			sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
				     sfp->sm_fault_retries == N_FAULT_INIT);
		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
	init_done:
			sfp->sm_phy_retries = R_PHY_RETRY;
			goto phy_probe;
		}
		break;

	case SFP_S_INIT_PHY:
		if (event != SFP_E_TIMEOUT)
			break;
	phy_probe:
		/* TX_FAULT deasserted or we timed out with TX_FAULT
		 * clear.  Probe for the PHY and check the LOS state.
		 */
		ret = sfp_sm_probe_for_phy(sfp);
		if (ret == -ENODEV) {
			if (--sfp->sm_phy_retries) {
				sfp_sm_next(sfp, SFP_S_INIT_PHY, T_PHY_RETRY);
				break;
			} else {
				dev_info(sfp->dev, "no PHY detected\n");
			}
		} else if (ret) {
			sfp_sm_next(sfp, SFP_S_FAIL, 0);
			break;
		}
		if (sfp_module_start(sfp->sfp_bus)) {
			sfp_sm_next(sfp, SFP_S_FAIL, 0);
			break;
		}
		sfp_sm_link_check_los(sfp);

		/* Reset the fault retry count */
		sfp->sm_fault_retries = N_FAULT;
		break;

	case SFP_S_INIT_TX_FAULT:
		if (event == SFP_E_TIMEOUT) {
			sfp_module_tx_fault_reset(sfp);
			sfp_sm_next(sfp, SFP_S_INIT, sfp->module_t_start_up);
		}
		break;

	case SFP_S_WAIT_LOS:
		if (event == SFP_E_TX_FAULT)
			sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
		else if (sfp_los_event_inactive(sfp, event))
			sfp_sm_link_up(sfp);
		break;

	case SFP_S_LINK_UP:
		if (event == SFP_E_TX_FAULT) {
			sfp_sm_link_down(sfp);
			sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
		} else if (sfp_los_event_active(sfp, event)) {
			sfp_sm_link_down(sfp);
			sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
		}
		break;

	case SFP_S_TX_FAULT:
		if (event == SFP_E_TIMEOUT) {
			sfp_module_tx_fault_reset(sfp);
			sfp_sm_next(sfp, SFP_S_REINIT, sfp->module_t_start_up);
		}
		break;

	case SFP_S_REINIT:
		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
			sfp_sm_fault(sfp, SFP_S_TX_FAULT, false);
		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
			dev_info(sfp->dev, "module transmit fault recovered\n");
			sfp_sm_link_check_los(sfp);
		}
		break;

	case SFP_S_TX_DISABLE:
		break;
	}
}

static void sfp_sm_event(struct sfp *sfp, unsigned int event)
{
	mutex_lock(&sfp->sm_mutex);

	dev_dbg(sfp->dev, "SM: enter %s:%s:%s event %s\n",
		mod_state_to_str(sfp->sm_mod_state),
		dev_state_to_str(sfp->sm_dev_state),
		sm_state_to_str(sfp->sm_state),
		event_to_str(event));

	sfp_sm_device(sfp, event);
	sfp_sm_module(sfp, event);
	sfp_sm_main(sfp, event);

	dev_dbg(sfp->dev, "SM: exit %s:%s:%s\n",
		mod_state_to_str(sfp->sm_mod_state),
		dev_state_to_str(sfp->sm_dev_state),
		sm_state_to_str(sfp->sm_state));

	mutex_unlock(&sfp->sm_mutex);
}

static void sfp_attach(struct sfp *sfp)
{
	sfp_sm_event(sfp, SFP_E_DEV_ATTACH);
}

static void sfp_detach(struct sfp *sfp)
{
	sfp_sm_event(sfp, SFP_E_DEV_DETACH);
}

static void sfp_start(struct sfp *sfp)
{
	sfp_sm_event(sfp, SFP_E_DEV_UP);
}

static void sfp_stop(struct sfp *sfp)
{
	sfp_sm_event(sfp, SFP_E_DEV_DOWN);
}

static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
{
	/* locking... and check module is present */

	if (sfp->id.ext.sff8472_compliance &&
	    !(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)) {
		modinfo->type = ETH_MODULE_SFF_8472;
		modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
	} else {
		modinfo->type = ETH_MODULE_SFF_8079;
		modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
	}
	return 0;
}

static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
			     u8 *data)
{
	unsigned int first, last, len;
	int ret;

	if (ee->len == 0)
		return -EINVAL;

	first = ee->offset;
	last = ee->offset + ee->len;
	if (first < ETH_MODULE_SFF_8079_LEN) {
		len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
		len -= first;

		ret = sfp_read(sfp, false, first, data, len);
		if (ret < 0)
			return ret;

		first += len;
		data += len;
	}
	if (first < ETH_MODULE_SFF_8472_LEN && last > ETH_MODULE_SFF_8079_LEN) {
		len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
		len -= first;
		first -= ETH_MODULE_SFF_8079_LEN;

		ret = sfp_read(sfp, true, first, data, len);
		if (ret < 0)
			return ret;
	}
	return 0;
}

static int sfp_module_eeprom_by_page(struct sfp *sfp,
				     const struct ethtool_module_eeprom *page,
				     struct netlink_ext_ack *extack)
{
	if (page->bank) {
		NL_SET_ERR_MSG(extack, "Banks not supported");
		return -EOPNOTSUPP;
	}

	if (page->page) {
		NL_SET_ERR_MSG(extack, "Only page 0 supported");
		return -EOPNOTSUPP;
	}

	if (page->i2c_address != 0x50 &&
	    page->i2c_address != 0x51) {
		NL_SET_ERR_MSG(extack, "Only address 0x50 and 0x51 supported");
		return -EOPNOTSUPP;
	}

	return sfp_read(sfp, page->i2c_address == 0x51, page->offset,
			page->data, page->length);
};

static const struct sfp_socket_ops sfp_module_ops = {
	.attach = sfp_attach,
	.detach = sfp_detach,
	.start = sfp_start,
	.stop = sfp_stop,
	.module_info = sfp_module_info,
	.module_eeprom = sfp_module_eeprom,
	.module_eeprom_by_page = sfp_module_eeprom_by_page,
};

static void sfp_timeout(struct work_struct *work)
{
	struct sfp *sfp = container_of(work, struct sfp, timeout.work);

	rtnl_lock();
	sfp_sm_event(sfp, SFP_E_TIMEOUT);
	rtnl_unlock();
}

static void sfp_check_state(struct sfp *sfp)
{
	unsigned int state, i, changed;

	mutex_lock(&sfp->st_mutex);
	state = sfp_get_state(sfp);
	changed = state ^ sfp->state;
	changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;

	for (i = 0; i < GPIO_MAX; i++)
		if (changed & BIT(i))
			dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
				!!(sfp->state & BIT(i)), !!(state & BIT(i)));

	state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
	sfp->state = state;

	rtnl_lock();
	if (changed & SFP_F_PRESENT)
		sfp_sm_event(sfp, state & SFP_F_PRESENT ?
				SFP_E_INSERT : SFP_E_REMOVE);

	if (changed & SFP_F_TX_FAULT)
		sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
				SFP_E_TX_FAULT : SFP_E_TX_CLEAR);

	if (changed & SFP_F_LOS)
		sfp_sm_event(sfp, state & SFP_F_LOS ?
				SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
	rtnl_unlock();
	mutex_unlock(&sfp->st_mutex);
}

static irqreturn_t sfp_irq(int irq, void *data)
{
	struct sfp *sfp = data;

	sfp_check_state(sfp);

	return IRQ_HANDLED;
}

static void sfp_poll(struct work_struct *work)
{
	struct sfp *sfp = container_of(work, struct sfp, poll.work);

	sfp_check_state(sfp);

	if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) ||
	    sfp->need_poll)
		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
}

static struct sfp *sfp_alloc(struct device *dev)
{
	struct sfp *sfp;

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

	sfp->dev = dev;

	mutex_init(&sfp->sm_mutex);
	mutex_init(&sfp->st_mutex);
	INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
	INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);

	sfp_hwmon_init(sfp);

	return sfp;
}

static void sfp_cleanup(void *data)
{
	struct sfp *sfp = data;

	sfp_hwmon_exit(sfp);

	cancel_delayed_work_sync(&sfp->poll);
	cancel_delayed_work_sync(&sfp->timeout);
	if (sfp->i2c_mii) {
		mdiobus_unregister(sfp->i2c_mii);
		mdiobus_free(sfp->i2c_mii);
	}
	if (sfp->i2c)
		i2c_put_adapter(sfp->i2c);
	kfree(sfp);
}

static int sfp_probe(struct platform_device *pdev)
{
	const struct sff_data *sff;
	struct i2c_adapter *i2c;
	char *sfp_irq_name;
	struct sfp *sfp;
	int err, i;

	sfp = sfp_alloc(&pdev->dev);
	if (IS_ERR(sfp))
		return PTR_ERR(sfp);

	platform_set_drvdata(pdev, sfp);

	err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
	if (err < 0)
		return err;

	sff = sfp->type = &sfp_data;

	if (pdev->dev.of_node) {
		struct device_node *node = pdev->dev.of_node;
		const struct of_device_id *id;
		struct device_node *np;

		id = of_match_node(sfp_of_match, node);
		if (WARN_ON(!id))
			return -EINVAL;

		sff = sfp->type = id->data;

		np = of_parse_phandle(node, "i2c-bus", 0);
		if (!np) {
			dev_err(sfp->dev, "missing 'i2c-bus' property\n");
			return -ENODEV;
		}

		i2c = of_find_i2c_adapter_by_node(np);
		of_node_put(np);
	} else if (has_acpi_companion(&pdev->dev)) {
		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
		struct fwnode_reference_args args;
		struct acpi_handle *acpi_handle;
		int ret;

		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
		if (ret || !is_acpi_device_node(args.fwnode)) {
			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
			return -ENODEV;
		}

		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
	} else {
		return -EINVAL;
	}

	if (!i2c)
		return -EPROBE_DEFER;

	err = sfp_i2c_configure(sfp, i2c);
	if (err < 0) {
		i2c_put_adapter(i2c);
		return err;
	}

	for (i = 0; i < GPIO_MAX; i++)
		if (sff->gpios & BIT(i)) {
			sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
					   gpio_of_names[i], gpio_flags[i]);
			if (IS_ERR(sfp->gpio[i]))
				return PTR_ERR(sfp->gpio[i]);
		}

	sfp->get_state = sfp_gpio_get_state;
	sfp->set_state = sfp_gpio_set_state;

	/* Modules that have no detect signal are always present */
	if (!(sfp->gpio[GPIO_MODDEF0]))
		sfp->get_state = sff_gpio_get_state;

	device_property_read_u32(&pdev->dev, "maximum-power-milliwatt",
				 &sfp->max_power_mW);
	if (!sfp->max_power_mW)
		sfp->max_power_mW = 1000;

	dev_info(sfp->dev, "Host maximum power %u.%uW\n",
		 sfp->max_power_mW / 1000, (sfp->max_power_mW / 100) % 10);

	/* Get the initial state, and always signal TX disable,
	 * since the network interface will not be up.
	 */
	sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;

	if (sfp->gpio[GPIO_RATE_SELECT] &&
	    gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
		sfp->state |= SFP_F_RATE_SELECT;
	sfp_set_state(sfp, sfp->state);
	sfp_module_tx_disable(sfp);
	if (sfp->state & SFP_F_PRESENT) {
		rtnl_lock();
		sfp_sm_event(sfp, SFP_E_INSERT);
		rtnl_unlock();
	}

	for (i = 0; i < GPIO_MAX; i++) {
		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
			continue;

		sfp->gpio_irq[i] = gpiod_to_irq(sfp->gpio[i]);
		if (sfp->gpio_irq[i] < 0) {
			sfp->gpio_irq[i] = 0;
			sfp->need_poll = true;
			continue;
		}

		sfp_irq_name = devm_kasprintf(sfp->dev, GFP_KERNEL,
					      "%s-%s", dev_name(sfp->dev),
					      gpio_of_names[i]);

		if (!sfp_irq_name)
			return -ENOMEM;

		err = devm_request_threaded_irq(sfp->dev, sfp->gpio_irq[i],
						NULL, sfp_irq,
						IRQF_ONESHOT |
						IRQF_TRIGGER_RISING |
						IRQF_TRIGGER_FALLING,
						sfp_irq_name, sfp);
		if (err) {
			sfp->gpio_irq[i] = 0;
			sfp->need_poll = true;
		}
	}

	if (sfp->need_poll)
		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);

	/* We could have an issue in cases no Tx disable pin is available or
	 * wired as modules using a laser as their light source will continue to
	 * be active when the fiber is removed. This could be a safety issue and
	 * we should at least warn the user about that.
	 */
	if (!sfp->gpio[GPIO_TX_DISABLE])
		dev_warn(sfp->dev,
			 "No tx_disable pin: SFP modules will always be emitting.\n");

	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
	if (!sfp->sfp_bus)
		return -ENOMEM;

	sfp_debugfs_init(sfp);

	return 0;
}

static int sfp_remove(struct platform_device *pdev)
{
	struct sfp *sfp = platform_get_drvdata(pdev);

	sfp_debugfs_exit(sfp);
	sfp_unregister_socket(sfp->sfp_bus);

	rtnl_lock();
	sfp_sm_event(sfp, SFP_E_REMOVE);
	rtnl_unlock();

	return 0;
}

static void sfp_shutdown(struct platform_device *pdev)
{
	struct sfp *sfp = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < GPIO_MAX; i++) {
		if (!sfp->gpio_irq[i])
			continue;

		devm_free_irq(sfp->dev, sfp->gpio_irq[i], sfp);
	}

	cancel_delayed_work_sync(&sfp->poll);
	cancel_delayed_work_sync(&sfp->timeout);
}

static struct platform_driver sfp_driver = {
	.probe = sfp_probe,
	.remove = sfp_remove,
	.shutdown = sfp_shutdown,
	.driver = {
		.name = "sfp",
		.of_match_table = sfp_of_match,
	},
};

static int sfp_init(void)
{
	poll_jiffies = msecs_to_jiffies(100);

	return platform_driver_register(&sfp_driver);
}
module_init(sfp_init);

static void sfp_exit(void)
{
	platform_driver_unregister(&sfp_driver);
}
module_exit(sfp_exit);

MODULE_ALIAS("platform:sfp");
MODULE_AUTHOR("Russell King");
MODULE_LICENSE("GPL v2");