Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
// SPDX-License-Identifier: GPL-2.0
/*
 * gadget.c - DesignWare USB3 DRD Controller Gadget Framework Link
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include "debug.h"
#include "core.h"
#include "gadget.h"
#include "io.h"

#define DWC3_ALIGN_FRAME(d, n)	(((d)->frame_number + ((d)->interval * (n))) \
					& ~((d)->interval - 1))

/**
 * dwc3_gadget_set_test_mode - enables usb2 test modes
 * @dwc: pointer to our context structure
 * @mode: the mode to set (J, K SE0 NAK, Force Enable)
 *
 * Caller should take care of locking. This function will return 0 on
 * success or -EINVAL if wrong Test Selector is passed.
 */
int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
{
	u32		reg;

	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	reg &= ~DWC3_DCTL_TSTCTRL_MASK;

	switch (mode) {
	case TEST_J:
	case TEST_K:
	case TEST_SE0_NAK:
	case TEST_PACKET:
	case TEST_FORCE_EN:
		reg |= mode << 1;
		break;
	default:
		return -EINVAL;
	}

	dwc3_writel(dwc->regs, DWC3_DCTL, reg);

	return 0;
}

/**
 * dwc3_gadget_get_link_state - gets current state of usb link
 * @dwc: pointer to our context structure
 *
 * Caller should take care of locking. This function will
 * return the link state on success (>= 0) or -ETIMEDOUT.
 */
int dwc3_gadget_get_link_state(struct dwc3 *dwc)
{
	u32		reg;

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);

	return DWC3_DSTS_USBLNKST(reg);
}

/**
 * dwc3_gadget_set_link_state - sets usb link to a particular state
 * @dwc: pointer to our context structure
 * @state: the state to put link into
 *
 * Caller should take care of locking. This function will
 * return 0 on success or -ETIMEDOUT.
 */
int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
{
	int		retries = 10000;
	u32		reg;

	/*
	 * Wait until device controller is ready. Only applies to 1.94a and
	 * later RTL.
	 */
	if (dwc->revision >= DWC3_REVISION_194A) {
		while (--retries) {
			reg = dwc3_readl(dwc->regs, DWC3_DSTS);
			if (reg & DWC3_DSTS_DCNRD)
				udelay(5);
			else
				break;
		}

		if (retries <= 0)
			return -ETIMEDOUT;
	}

	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;

	/* set requested state */
	reg |= DWC3_DCTL_ULSTCHNGREQ(state);
	dwc3_writel(dwc->regs, DWC3_DCTL, reg);

	/*
	 * The following code is racy when called from dwc3_gadget_wakeup,
	 * and is not needed, at least on newer versions
	 */
	if (dwc->revision >= DWC3_REVISION_194A)
		return 0;

	/* wait for a change in DSTS */
	retries = 10000;
	while (--retries) {
		reg = dwc3_readl(dwc->regs, DWC3_DSTS);

		if (DWC3_DSTS_USBLNKST(reg) == state)
			return 0;

		udelay(5);
	}

	return -ETIMEDOUT;
}

/**
 * dwc3_ep_inc_trb - increment a trb index.
 * @index: Pointer to the TRB index to increment.
 *
 * The index should never point to the link TRB. After incrementing,
 * if it is point to the link TRB, wrap around to the beginning. The
 * link TRB is always at the last TRB entry.
 */
static void dwc3_ep_inc_trb(u8 *index)
{
	(*index)++;
	if (*index == (DWC3_TRB_NUM - 1))
		*index = 0;
}

/**
 * dwc3_ep_inc_enq - increment endpoint's enqueue pointer
 * @dep: The endpoint whose enqueue pointer we're incrementing
 */
static void dwc3_ep_inc_enq(struct dwc3_ep *dep)
{
	dwc3_ep_inc_trb(&dep->trb_enqueue);
}

/**
 * dwc3_ep_inc_deq - increment endpoint's dequeue pointer
 * @dep: The endpoint whose enqueue pointer we're incrementing
 */
static void dwc3_ep_inc_deq(struct dwc3_ep *dep)
{
	dwc3_ep_inc_trb(&dep->trb_dequeue);
}

static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep,
		struct dwc3_request *req, int status)
{
	struct dwc3			*dwc = dep->dwc;

	list_del(&req->list);
	req->remaining = 0;
	req->needs_extra_trb = false;

	if (req->request.status == -EINPROGRESS)
		req->request.status = status;

	if (req->trb)
		usb_gadget_unmap_request_by_dev(dwc->sysdev,
				&req->request, req->direction);

	req->trb = NULL;
	trace_dwc3_gadget_giveback(req);

	if (dep->number > 1)
		pm_runtime_put(dwc->dev);
}

/**
 * dwc3_gadget_giveback - call struct usb_request's ->complete callback
 * @dep: The endpoint to whom the request belongs to
 * @req: The request we're giving back
 * @status: completion code for the request
 *
 * Must be called with controller's lock held and interrupts disabled. This
 * function will unmap @req and call its ->complete() callback to notify upper
 * layers that it has completed.
 */
void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
		int status)
{
	struct dwc3			*dwc = dep->dwc;

	dwc3_gadget_del_and_unmap_request(dep, req, status);
	req->status = DWC3_REQUEST_STATUS_COMPLETED;

	spin_unlock(&dwc->lock);
	usb_gadget_giveback_request(&dep->endpoint, &req->request);
	spin_lock(&dwc->lock);
}

/**
 * dwc3_send_gadget_generic_command - issue a generic command for the controller
 * @dwc: pointer to the controller context
 * @cmd: the command to be issued
 * @param: command parameter
 *
 * Caller should take care of locking. Issue @cmd with a given @param to @dwc
 * and wait for its completion.
 */
int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
{
	u32		timeout = 500;
	int		status = 0;
	int		ret = 0;
	u32		reg;

	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
	dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);

	do {
		reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
		if (!(reg & DWC3_DGCMD_CMDACT)) {
			status = DWC3_DGCMD_STATUS(reg);
			if (status)
				ret = -EINVAL;
			break;
		}
	} while (--timeout);

	if (!timeout) {
		ret = -ETIMEDOUT;
		status = -ETIMEDOUT;
	}

	trace_dwc3_gadget_generic_cmd(cmd, param, status);

	return ret;
}

static int __dwc3_gadget_wakeup(struct dwc3 *dwc);

/**
 * dwc3_send_gadget_ep_cmd - issue an endpoint command
 * @dep: the endpoint to which the command is going to be issued
 * @cmd: the command to be issued
 * @params: parameters to the command
 *
 * Caller should handle locking. This function will issue @cmd with given
 * @params to @dep and wait for its completion.
 */
int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
		struct dwc3_gadget_ep_cmd_params *params)
{
	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
	struct dwc3		*dwc = dep->dwc;
	u32			timeout = 1000;
	u32			saved_config = 0;
	u32			reg;

	int			cmd_status = 0;
	int			ret = -EINVAL;

	/*
	 * When operating in USB 2.0 speeds (HS/FS), if GUSB2PHYCFG.ENBLSLPM or
	 * GUSB2PHYCFG.SUSPHY is set, it must be cleared before issuing an
	 * endpoint command.
	 *
	 * Save and clear both GUSB2PHYCFG.ENBLSLPM and GUSB2PHYCFG.SUSPHY
	 * settings. Restore them after the command is completed.
	 *
	 * DWC_usb3 3.30a and DWC_usb31 1.90a programming guide section 3.2.2
	 */
	if (dwc->gadget.speed <= USB_SPEED_HIGH) {
		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
		if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
			saved_config |= DWC3_GUSB2PHYCFG_SUSPHY;
			reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
		}

		if (reg & DWC3_GUSB2PHYCFG_ENBLSLPM) {
			saved_config |= DWC3_GUSB2PHYCFG_ENBLSLPM;
			reg &= ~DWC3_GUSB2PHYCFG_ENBLSLPM;
		}

		if (saved_config)
			dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
	}

	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
		int		needs_wakeup;

		needs_wakeup = (dwc->link_state == DWC3_LINK_STATE_U1 ||
				dwc->link_state == DWC3_LINK_STATE_U2 ||
				dwc->link_state == DWC3_LINK_STATE_U3);

		if (unlikely(needs_wakeup)) {
			ret = __dwc3_gadget_wakeup(dwc);
			dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
					ret);
		}
	}

	dwc3_writel(dep->regs, DWC3_DEPCMDPAR0, params->param0);
	dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1);
	dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2);

	/*
	 * Synopsys Databook 2.60a states in section 6.3.2.5.6 of that if we're
	 * not relying on XferNotReady, we can make use of a special "No
	 * Response Update Transfer" command where we should clear both CmdAct
	 * and CmdIOC bits.
	 *
	 * With this, we don't need to wait for command completion and can
	 * straight away issue further commands to the endpoint.
	 *
	 * NOTICE: We're making an assumption that control endpoints will never
	 * make use of Update Transfer command. This is a safe assumption
	 * because we can never have more than one request at a time with
	 * Control Endpoints. If anybody changes that assumption, this chunk
	 * needs to be updated accordingly.
	 */
	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_UPDATETRANSFER &&
			!usb_endpoint_xfer_isoc(desc))
		cmd &= ~(DWC3_DEPCMD_CMDIOC | DWC3_DEPCMD_CMDACT);
	else
		cmd |= DWC3_DEPCMD_CMDACT;

	dwc3_writel(dep->regs, DWC3_DEPCMD, cmd);
	do {
		reg = dwc3_readl(dep->regs, DWC3_DEPCMD);
		if (!(reg & DWC3_DEPCMD_CMDACT)) {
			cmd_status = DWC3_DEPCMD_STATUS(reg);

			switch (cmd_status) {
			case 0:
				ret = 0;
				break;
			case DEPEVT_TRANSFER_NO_RESOURCE:
				ret = -EINVAL;
				break;
			case DEPEVT_TRANSFER_BUS_EXPIRY:
				/*
				 * SW issues START TRANSFER command to
				 * isochronous ep with future frame interval. If
				 * future interval time has already passed when
				 * core receives the command, it will respond
				 * with an error status of 'Bus Expiry'.
				 *
				 * Instead of always returning -EINVAL, let's
				 * give a hint to the gadget driver that this is
				 * the case by returning -EAGAIN.
				 */
				ret = -EAGAIN;
				break;
			default:
				dev_WARN(dwc->dev, "UNKNOWN cmd status\n");
			}

			break;
		}
	} while (--timeout);

	if (timeout == 0) {
		ret = -ETIMEDOUT;
		cmd_status = -ETIMEDOUT;
	}

	trace_dwc3_gadget_ep_cmd(dep, cmd, params, cmd_status);

	if (ret == 0 && DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
		dep->flags |= DWC3_EP_TRANSFER_STARTED;
		dwc3_gadget_ep_get_transfer_index(dep);
	}

	if (saved_config) {
		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
		reg |= saved_config;
		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
	}

	return ret;
}

static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
{
	struct dwc3 *dwc = dep->dwc;
	struct dwc3_gadget_ep_cmd_params params;
	u32 cmd = DWC3_DEPCMD_CLEARSTALL;

	/*
	 * As of core revision 2.60a the recommended programming model
	 * is to set the ClearPendIN bit when issuing a Clear Stall EP
	 * command for IN endpoints. This is to prevent an issue where
	 * some (non-compliant) hosts may not send ACK TPs for pending
	 * IN transfers due to a mishandled error condition. Synopsys
	 * STAR 9000614252.
	 */
	if (dep->direction && (dwc->revision >= DWC3_REVISION_260A) &&
	    (dwc->gadget.speed >= USB_SPEED_SUPER))
		cmd |= DWC3_DEPCMD_CLEARPENDIN;

	memset(&params, 0, sizeof(params));

	return dwc3_send_gadget_ep_cmd(dep, cmd, &params);
}

static dma_addr_t dwc3_trb_dma_offset(struct dwc3_ep *dep,
		struct dwc3_trb *trb)
{
	u32		offset = (char *) trb - (char *) dep->trb_pool;

	return dep->trb_pool_dma + offset;
}

static int dwc3_alloc_trb_pool(struct dwc3_ep *dep)
{
	struct dwc3		*dwc = dep->dwc;

	if (dep->trb_pool)
		return 0;

	dep->trb_pool = dma_alloc_coherent(dwc->sysdev,
			sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
			&dep->trb_pool_dma, GFP_KERNEL);
	if (!dep->trb_pool) {
		dev_err(dep->dwc->dev, "failed to allocate trb pool for %s\n",
				dep->name);
		return -ENOMEM;
	}

	return 0;
}

static void dwc3_free_trb_pool(struct dwc3_ep *dep)
{
	struct dwc3		*dwc = dep->dwc;

	dma_free_coherent(dwc->sysdev, sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
			dep->trb_pool, dep->trb_pool_dma);

	dep->trb_pool = NULL;
	dep->trb_pool_dma = 0;
}

static int dwc3_gadget_set_xfer_resource(struct dwc3_ep *dep)
{
	struct dwc3_gadget_ep_cmd_params params;

	memset(&params, 0x00, sizeof(params));

	params.param0 = DWC3_DEPXFERCFG_NUM_XFER_RES(1);

	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETTRANSFRESOURCE,
			&params);
}

/**
 * dwc3_gadget_start_config - configure ep resources
 * @dep: endpoint that is being enabled
 *
 * Issue a %DWC3_DEPCMD_DEPSTARTCFG command to @dep. After the command's
 * completion, it will set Transfer Resource for all available endpoints.
 *
 * The assignment of transfer resources cannot perfectly follow the data book
 * due to the fact that the controller driver does not have all knowledge of the
 * configuration in advance. It is given this information piecemeal by the
 * composite gadget framework after every SET_CONFIGURATION and
 * SET_INTERFACE. Trying to follow the databook programming model in this
 * scenario can cause errors. For two reasons:
 *
 * 1) The databook says to do %DWC3_DEPCMD_DEPSTARTCFG for every
 * %USB_REQ_SET_CONFIGURATION and %USB_REQ_SET_INTERFACE (8.1.5). This is
 * incorrect in the scenario of multiple interfaces.
 *
 * 2) The databook does not mention doing more %DWC3_DEPCMD_DEPXFERCFG for new
 * endpoint on alt setting (8.1.6).
 *
 * The following simplified method is used instead:
 *
 * All hardware endpoints can be assigned a transfer resource and this setting
 * will stay persistent until either a core reset or hibernation. So whenever we
 * do a %DWC3_DEPCMD_DEPSTARTCFG(0) we can go ahead and do
 * %DWC3_DEPCMD_DEPXFERCFG for every hardware endpoint as well. We are
 * guaranteed that there are as many transfer resources as endpoints.
 *
 * This function is called for each endpoint when it is being enabled but is
 * triggered only when called for EP0-out, which always happens first, and which
 * should only happen in one of the above conditions.
 */
static int dwc3_gadget_start_config(struct dwc3_ep *dep)
{
	struct dwc3_gadget_ep_cmd_params params;
	struct dwc3		*dwc;
	u32			cmd;
	int			i;
	int			ret;

	if (dep->number)
		return 0;

	memset(&params, 0x00, sizeof(params));
	cmd = DWC3_DEPCMD_DEPSTARTCFG;
	dwc = dep->dwc;

	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
	if (ret)
		return ret;

	for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
		struct dwc3_ep *dep = dwc->eps[i];

		if (!dep)
			continue;

		ret = dwc3_gadget_set_xfer_resource(dep);
		if (ret)
			return ret;
	}

	return 0;
}

static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
{
	const struct usb_ss_ep_comp_descriptor *comp_desc;
	const struct usb_endpoint_descriptor *desc;
	struct dwc3_gadget_ep_cmd_params params;
	struct dwc3 *dwc = dep->dwc;

	comp_desc = dep->endpoint.comp_desc;
	desc = dep->endpoint.desc;

	memset(&params, 0x00, sizeof(params));

	params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
		| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc));

	/* Burst size is only needed in SuperSpeed mode */
	if (dwc->gadget.speed >= USB_SPEED_SUPER) {
		u32 burst = dep->endpoint.maxburst;
		params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst - 1);
	}

	params.param0 |= action;
	if (action == DWC3_DEPCFG_ACTION_RESTORE)
		params.param2 |= dep->saved_state;

	if (usb_endpoint_xfer_control(desc))
		params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN;

	if (dep->number <= 1 || usb_endpoint_xfer_isoc(desc))
		params.param1 |= DWC3_DEPCFG_XFER_NOT_READY_EN;

	if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
		params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
			| DWC3_DEPCFG_STREAM_EVENT_EN;
		dep->stream_capable = true;
	}

	if (!usb_endpoint_xfer_control(desc))
		params.param1 |= DWC3_DEPCFG_XFER_IN_PROGRESS_EN;

	/*
	 * We are doing 1:1 mapping for endpoints, meaning
	 * Physical Endpoints 2 maps to Logical Endpoint 2 and
	 * so on. We consider the direction bit as part of the physical
	 * endpoint number. So USB endpoint 0x81 is 0x03.
	 */
	params.param1 |= DWC3_DEPCFG_EP_NUMBER(dep->number);

	/*
	 * We must use the lower 16 TX FIFOs even though
	 * HW might have more
	 */
	if (dep->direction)
		params.param0 |= DWC3_DEPCFG_FIFO_NUMBER(dep->number >> 1);

	if (desc->bInterval) {
		params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(desc->bInterval - 1);
		dep->interval = 1 << (desc->bInterval - 1);
	}

	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);
}

/**
 * __dwc3_gadget_ep_enable - initializes a hw endpoint
 * @dep: endpoint to be initialized
 * @action: one of INIT, MODIFY or RESTORE
 *
 * Caller should take care of locking. Execute all necessary commands to
 * initialize a HW endpoint so it can be used by a gadget driver.
 */
static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
{
	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
	struct dwc3		*dwc = dep->dwc;

	u32			reg;
	int			ret;

	if (!(dep->flags & DWC3_EP_ENABLED)) {
		ret = dwc3_gadget_start_config(dep);
		if (ret)
			return ret;
	}

	ret = dwc3_gadget_set_ep_config(dep, action);
	if (ret)
		return ret;

	if (!(dep->flags & DWC3_EP_ENABLED)) {
		struct dwc3_trb	*trb_st_hw;
		struct dwc3_trb	*trb_link;

		dep->type = usb_endpoint_type(desc);
		dep->flags |= DWC3_EP_ENABLED;

		reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
		reg |= DWC3_DALEPENA_EP(dep->number);
		dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);

		if (usb_endpoint_xfer_control(desc))
			goto out;

		/* Initialize the TRB ring */
		dep->trb_dequeue = 0;
		dep->trb_enqueue = 0;
		memset(dep->trb_pool, 0,
		       sizeof(struct dwc3_trb) * DWC3_TRB_NUM);

		/* Link TRB. The HWO bit is never reset */
		trb_st_hw = &dep->trb_pool[0];

		trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
		trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
		trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
		trb_link->ctrl |= DWC3_TRBCTL_LINK_TRB;
		trb_link->ctrl |= DWC3_TRB_CTRL_HWO;
	}

	/*
	 * Issue StartTransfer here with no-op TRB so we can always rely on No
	 * Response Update Transfer command.
	 */
	if ((usb_endpoint_xfer_bulk(desc) && !dep->stream_capable) ||
			usb_endpoint_xfer_int(desc)) {
		struct dwc3_gadget_ep_cmd_params params;
		struct dwc3_trb	*trb;
		dma_addr_t trb_dma;
		u32 cmd;

		memset(&params, 0, sizeof(params));
		trb = &dep->trb_pool[0];
		trb_dma = dwc3_trb_dma_offset(dep, trb);

		params.param0 = upper_32_bits(trb_dma);
		params.param1 = lower_32_bits(trb_dma);

		cmd = DWC3_DEPCMD_STARTTRANSFER;

		ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
		if (ret < 0)
			return ret;
	}

out:
	trace_dwc3_gadget_ep_enable(dep);

	return 0;
}

static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
		bool interrupt);
static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
{
	struct dwc3_request		*req;

	dwc3_stop_active_transfer(dep, true, false);

	/* - giveback all requests to gadget driver */
	while (!list_empty(&dep->started_list)) {
		req = next_request(&dep->started_list);

		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
	}

	while (!list_empty(&dep->pending_list)) {
		req = next_request(&dep->pending_list);

		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
	}

	while (!list_empty(&dep->cancelled_list)) {
		req = next_request(&dep->cancelled_list);

		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
	}
}

/**
 * __dwc3_gadget_ep_disable - disables a hw endpoint
 * @dep: the endpoint to disable
 *
 * This function undoes what __dwc3_gadget_ep_enable did and also removes
 * requests which are currently being processed by the hardware and those which
 * are not yet scheduled.
 *
 * Caller should take care of locking.
 */
static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
{
	struct dwc3		*dwc = dep->dwc;
	u32			reg;

	trace_dwc3_gadget_ep_disable(dep);

	dwc3_remove_requests(dwc, dep);

	/* make sure HW endpoint isn't stalled */
	if (dep->flags & DWC3_EP_STALL)
		__dwc3_gadget_ep_set_halt(dep, 0, false);

	reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
	reg &= ~DWC3_DALEPENA_EP(dep->number);
	dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);

	dep->stream_capable = false;
	dep->type = 0;
	dep->flags = 0;

	/* Clear out the ep descriptors for non-ep0 */
	if (dep->number > 1) {
		dep->endpoint.comp_desc = NULL;
		dep->endpoint.desc = NULL;
	}

	return 0;
}

/* -------------------------------------------------------------------------- */

static int dwc3_gadget_ep0_enable(struct usb_ep *ep,
		const struct usb_endpoint_descriptor *desc)
{
	return -EINVAL;
}

static int dwc3_gadget_ep0_disable(struct usb_ep *ep)
{
	return -EINVAL;
}

/* -------------------------------------------------------------------------- */

static int dwc3_gadget_ep_enable(struct usb_ep *ep,
		const struct usb_endpoint_descriptor *desc)
{
	struct dwc3_ep			*dep;
	struct dwc3			*dwc;
	unsigned long			flags;
	int				ret;

	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
		pr_debug("dwc3: invalid parameters\n");
		return -EINVAL;
	}

	if (!desc->wMaxPacketSize) {
		pr_debug("dwc3: missing wMaxPacketSize\n");
		return -EINVAL;
	}

	dep = to_dwc3_ep(ep);
	dwc = dep->dwc;

	if (dev_WARN_ONCE(dwc->dev, dep->flags & DWC3_EP_ENABLED,
					"%s is already enabled\n",
					dep->name))
		return 0;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static int dwc3_gadget_ep_disable(struct usb_ep *ep)
{
	struct dwc3_ep			*dep;
	struct dwc3			*dwc;
	unsigned long			flags;
	int				ret;

	if (!ep) {
		pr_debug("dwc3: invalid parameters\n");
		return -EINVAL;
	}

	dep = to_dwc3_ep(ep);
	dwc = dep->dwc;

	if (dev_WARN_ONCE(dwc->dev, !(dep->flags & DWC3_EP_ENABLED),
					"%s is already disabled\n",
					dep->name))
		return 0;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = __dwc3_gadget_ep_disable(dep);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
		gfp_t gfp_flags)
{
	struct dwc3_request		*req;
	struct dwc3_ep			*dep = to_dwc3_ep(ep);

	req = kzalloc(sizeof(*req), gfp_flags);
	if (!req)
		return NULL;

	req->direction	= dep->direction;
	req->epnum	= dep->number;
	req->dep	= dep;
	req->status	= DWC3_REQUEST_STATUS_UNKNOWN;

	trace_dwc3_alloc_request(req);

	return &req->request;
}

static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
		struct usb_request *request)
{
	struct dwc3_request		*req = to_dwc3_request(request);

	trace_dwc3_free_request(req);
	kfree(req);
}

/**
 * dwc3_ep_prev_trb - returns the previous TRB in the ring
 * @dep: The endpoint with the TRB ring
 * @index: The index of the current TRB in the ring
 *
 * Returns the TRB prior to the one pointed to by the index. If the
 * index is 0, we will wrap backwards, skip the link TRB, and return
 * the one just before that.
 */
static struct dwc3_trb *dwc3_ep_prev_trb(struct dwc3_ep *dep, u8 index)
{
	u8 tmp = index;

	if (!tmp)
		tmp = DWC3_TRB_NUM - 1;

	return &dep->trb_pool[tmp - 1];
}

static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
{
	struct dwc3_trb		*tmp;
	u8			trbs_left;

	/*
	 * If enqueue & dequeue are equal than it is either full or empty.
	 *
	 * One way to know for sure is if the TRB right before us has HWO bit
	 * set or not. If it has, then we're definitely full and can't fit any
	 * more transfers in our ring.
	 */
	if (dep->trb_enqueue == dep->trb_dequeue) {
		tmp = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
		if (tmp->ctrl & DWC3_TRB_CTRL_HWO)
			return 0;

		return DWC3_TRB_NUM - 1;
	}

	trbs_left = dep->trb_dequeue - dep->trb_enqueue;
	trbs_left &= (DWC3_TRB_NUM - 1);

	if (dep->trb_dequeue < dep->trb_enqueue)
		trbs_left--;

	return trbs_left;
}

static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
		dma_addr_t dma, unsigned length, unsigned chain, unsigned node,
		unsigned stream_id, unsigned short_not_ok, unsigned no_interrupt)
{
	struct dwc3		*dwc = dep->dwc;
	struct usb_gadget	*gadget = &dwc->gadget;
	enum usb_device_speed	speed = gadget->speed;

	trb->size = DWC3_TRB_SIZE_LENGTH(length);
	trb->bpl = lower_32_bits(dma);
	trb->bph = upper_32_bits(dma);

	switch (usb_endpoint_type(dep->endpoint.desc)) {
	case USB_ENDPOINT_XFER_CONTROL:
		trb->ctrl = DWC3_TRBCTL_CONTROL_SETUP;
		break;

	case USB_ENDPOINT_XFER_ISOC:
		if (!node) {
			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS_FIRST;

			/*
			 * USB Specification 2.0 Section 5.9.2 states that: "If
			 * there is only a single transaction in the microframe,
			 * only a DATA0 data packet PID is used.  If there are
			 * two transactions per microframe, DATA1 is used for
			 * the first transaction data packet and DATA0 is used
			 * for the second transaction data packet.  If there are
			 * three transactions per microframe, DATA2 is used for
			 * the first transaction data packet, DATA1 is used for
			 * the second, and DATA0 is used for the third."
			 *
			 * IOW, we should satisfy the following cases:
			 *
			 * 1) length <= maxpacket
			 *	- DATA0
			 *
			 * 2) maxpacket < length <= (2 * maxpacket)
			 *	- DATA1, DATA0
			 *
			 * 3) (2 * maxpacket) < length <= (3 * maxpacket)
			 *	- DATA2, DATA1, DATA0
			 */
			if (speed == USB_SPEED_HIGH) {
				struct usb_ep *ep = &dep->endpoint;
				unsigned int mult = 2;
				unsigned int maxp = usb_endpoint_maxp(ep->desc);

				if (length <= (2 * maxp))
					mult--;

				if (length <= maxp)
					mult--;

				trb->size |= DWC3_TRB_SIZE_PCM1(mult);
			}
		} else {
			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;
		}

		/* always enable Interrupt on Missed ISOC */
		trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
		break;

	case USB_ENDPOINT_XFER_BULK:
	case USB_ENDPOINT_XFER_INT:
		trb->ctrl = DWC3_TRBCTL_NORMAL;
		break;
	default:
		/*
		 * This is only possible with faulty memory because we
		 * checked it already :)
		 */
		dev_WARN(dwc->dev, "Unknown endpoint type %d\n",
				usb_endpoint_type(dep->endpoint.desc));
	}

	/*
	 * Enable Continue on Short Packet
	 * when endpoint is not a stream capable
	 */
	if (usb_endpoint_dir_out(dep->endpoint.desc)) {
		if (!dep->stream_capable)
			trb->ctrl |= DWC3_TRB_CTRL_CSP;

		if (short_not_ok)
			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
	}

	if ((!no_interrupt && !chain) ||
			(dwc3_calc_trbs_left(dep) == 1))
		trb->ctrl |= DWC3_TRB_CTRL_IOC;

	if (chain)
		trb->ctrl |= DWC3_TRB_CTRL_CHN;

	if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
		trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(stream_id);

	trb->ctrl |= DWC3_TRB_CTRL_HWO;

	dwc3_ep_inc_enq(dep);

	trace_dwc3_prepare_trb(dep, trb);
}

/**
 * dwc3_prepare_one_trb - setup one TRB from one request
 * @dep: endpoint for which this request is prepared
 * @req: dwc3_request pointer
 * @chain: should this TRB be chained to the next?
 * @node: only for isochronous endpoints. First TRB needs different type.
 */
static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
		struct dwc3_request *req, unsigned chain, unsigned node)
{
	struct dwc3_trb		*trb;
	unsigned int		length;
	dma_addr_t		dma;
	unsigned		stream_id = req->request.stream_id;
	unsigned		short_not_ok = req->request.short_not_ok;
	unsigned		no_interrupt = req->request.no_interrupt;

	if (req->request.num_sgs > 0) {
		length = sg_dma_len(req->start_sg);
		dma = sg_dma_address(req->start_sg);
	} else {
		length = req->request.length;
		dma = req->request.dma;
	}

	trb = &dep->trb_pool[dep->trb_enqueue];

	if (!req->trb) {
		dwc3_gadget_move_started_request(req);
		req->trb = trb;
		req->trb_dma = dwc3_trb_dma_offset(dep, trb);
	}

	req->num_trbs++;

	__dwc3_prepare_one_trb(dep, trb, dma, length, chain, node,
			stream_id, short_not_ok, no_interrupt);
}

static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
		struct dwc3_request *req)
{
	struct scatterlist *sg = req->start_sg;
	struct scatterlist *s;
	int		i;

	unsigned int remaining = req->request.num_mapped_sgs
		- req->num_queued_sgs;

	for_each_sg(sg, s, remaining, i) {
		unsigned int length = req->request.length;
		unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
		unsigned int rem = length % maxp;
		unsigned chain = true;

		if (sg_is_last(s))
			chain = false;

		if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
			struct dwc3	*dwc = dep->dwc;
			struct dwc3_trb	*trb;

			req->needs_extra_trb = true;

			/* prepare normal TRB */
			dwc3_prepare_one_trb(dep, req, true, i);

			/* Now prepare one extra TRB to align transfer size */
			trb = &dep->trb_pool[dep->trb_enqueue];
			req->num_trbs++;
			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
					maxp - rem, false, 1,
					req->request.stream_id,
					req->request.short_not_ok,
					req->request.no_interrupt);
		} else {
			dwc3_prepare_one_trb(dep, req, chain, i);
		}

		/*
		 * There can be a situation where all sgs in sglist are not
		 * queued because of insufficient trb number. To handle this
		 * case, update start_sg to next sg to be queued, so that
		 * we have free trbs we can continue queuing from where we
		 * previously stopped
		 */
		if (chain)
			req->start_sg = sg_next(s);

		req->num_queued_sgs++;

		if (!dwc3_calc_trbs_left(dep))
			break;
	}
}

static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
		struct dwc3_request *req)
{
	unsigned int length = req->request.length;
	unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
	unsigned int rem = length % maxp;

	if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
		struct dwc3	*dwc = dep->dwc;
		struct dwc3_trb	*trb;

		req->needs_extra_trb = true;

		/* prepare normal TRB */
		dwc3_prepare_one_trb(dep, req, true, 0);

		/* Now prepare one extra TRB to align transfer size */
		trb = &dep->trb_pool[dep->trb_enqueue];
		req->num_trbs++;
		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
				false, 1, req->request.stream_id,
				req->request.short_not_ok,
				req->request.no_interrupt);
	} else if (req->request.zero && req->request.length &&
		   (IS_ALIGNED(req->request.length, maxp))) {
		struct dwc3	*dwc = dep->dwc;
		struct dwc3_trb	*trb;

		req->needs_extra_trb = true;

		/* prepare normal TRB */
		dwc3_prepare_one_trb(dep, req, true, 0);

		/* Now prepare one extra TRB to handle ZLP */
		trb = &dep->trb_pool[dep->trb_enqueue];
		req->num_trbs++;
		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
				false, 1, req->request.stream_id,
				req->request.short_not_ok,
				req->request.no_interrupt);
	} else {
		dwc3_prepare_one_trb(dep, req, false, 0);
	}
}

/*
 * dwc3_prepare_trbs - setup TRBs from requests
 * @dep: endpoint for which requests are being prepared
 *
 * The function goes through the requests list and sets up TRBs for the
 * transfers. The function returns once there are no more TRBs available or
 * it runs out of requests.
 */
static void dwc3_prepare_trbs(struct dwc3_ep *dep)
{
	struct dwc3_request	*req, *n;

	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);

	/*
	 * We can get in a situation where there's a request in the started list
	 * but there weren't enough TRBs to fully kick it in the first time
	 * around, so it has been waiting for more TRBs to be freed up.
	 *
	 * In that case, we should check if we have a request with pending_sgs
	 * in the started list and prepare TRBs for that request first,
	 * otherwise we will prepare TRBs completely out of order and that will
	 * break things.
	 */
	list_for_each_entry(req, &dep->started_list, list) {
		if (req->num_pending_sgs > 0)
			dwc3_prepare_one_trb_sg(dep, req);

		if (!dwc3_calc_trbs_left(dep))
			return;
	}

	list_for_each_entry_safe(req, n, &dep->pending_list, list) {
		struct dwc3	*dwc = dep->dwc;
		int		ret;

		ret = usb_gadget_map_request_by_dev(dwc->sysdev, &req->request,
						    dep->direction);
		if (ret)
			return;

		req->sg			= req->request.sg;
		req->start_sg		= req->sg;
		req->num_queued_sgs	= 0;
		req->num_pending_sgs	= req->request.num_mapped_sgs;

		if (req->num_pending_sgs > 0)
			dwc3_prepare_one_trb_sg(dep, req);
		else
			dwc3_prepare_one_trb_linear(dep, req);

		if (!dwc3_calc_trbs_left(dep))
			return;
	}
}

static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
{
	struct dwc3_gadget_ep_cmd_params params;
	struct dwc3_request		*req;
	int				starting;
	int				ret;
	u32				cmd;

	if (!dwc3_calc_trbs_left(dep))
		return 0;

	starting = !(dep->flags & DWC3_EP_TRANSFER_STARTED);

	dwc3_prepare_trbs(dep);
	req = next_request(&dep->started_list);
	if (!req) {
		dep->flags |= DWC3_EP_PENDING_REQUEST;
		return 0;
	}

	memset(&params, 0, sizeof(params));

	if (starting) {
		params.param0 = upper_32_bits(req->trb_dma);
		params.param1 = lower_32_bits(req->trb_dma);
		cmd = DWC3_DEPCMD_STARTTRANSFER;

		if (dep->stream_capable)
			cmd |= DWC3_DEPCMD_PARAM(req->request.stream_id);

		if (usb_endpoint_xfer_isoc(dep->endpoint.desc))
			cmd |= DWC3_DEPCMD_PARAM(dep->frame_number);
	} else {
		cmd = DWC3_DEPCMD_UPDATETRANSFER |
			DWC3_DEPCMD_PARAM(dep->resource_index);
	}

	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
	if (ret < 0) {
		/*
		 * FIXME we need to iterate over the list of requests
		 * here and stop, unmap, free and del each of the linked
		 * requests instead of what we do now.
		 */
		if (req->trb)
			memset(req->trb, 0, sizeof(struct dwc3_trb));
		dwc3_gadget_del_and_unmap_request(dep, req, ret);
		return ret;
	}

	return 0;
}

static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
{
	u32			reg;

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
	return DWC3_DSTS_SOFFN(reg);
}

/**
 * dwc3_gadget_start_isoc_quirk - workaround invalid frame number
 * @dep: isoc endpoint
 *
 * This function tests for the correct combination of BIT[15:14] from the 16-bit
 * microframe number reported by the XferNotReady event for the future frame
 * number to start the isoc transfer.
 *
 * In DWC_usb31 version 1.70a-ea06 and prior, for highspeed and fullspeed
 * isochronous IN, BIT[15:14] of the 16-bit microframe number reported by the
 * XferNotReady event are invalid. The driver uses this number to schedule the
 * isochronous transfer and passes it to the START TRANSFER command. Because
 * this number is invalid, the command may fail. If BIT[15:14] matches the
 * internal 16-bit microframe, the START TRANSFER command will pass and the
 * transfer will start at the scheduled time, if it is off by 1, the command
 * will still pass, but the transfer will start 2 seconds in the future. For all
 * other conditions, the START TRANSFER command will fail with bus-expiry.
 *
 * In order to workaround this issue, we can test for the correct combination of
 * BIT[15:14] by sending START TRANSFER commands with different values of
 * BIT[15:14]: 'b00, 'b01, 'b10, and 'b11. Each combination is 2^14 uframe apart
 * (or 2 seconds). 4 seconds into the future will result in a bus-expiry status.
 * As the result, within the 4 possible combinations for BIT[15:14], there will
 * be 2 successful and 2 failure START COMMAND status. One of the 2 successful
 * command status will result in a 2-second delay start. The smaller BIT[15:14]
 * value is the correct combination.
 *
 * Since there are only 4 outcomes and the results are ordered, we can simply
 * test 2 START TRANSFER commands with BIT[15:14] combinations 'b00 and 'b01 to
 * deduce the smaller successful combination.
 *
 * Let test0 = test status for combination 'b00 and test1 = test status for 'b01
 * of BIT[15:14]. The correct combination is as follow:
 *
 * if test0 fails and test1 passes, BIT[15:14] is 'b01
 * if test0 fails and test1 fails, BIT[15:14] is 'b10
 * if test0 passes and test1 fails, BIT[15:14] is 'b11
 * if test0 passes and test1 passes, BIT[15:14] is 'b00
 *
 * Synopsys STAR 9001202023: Wrong microframe number for isochronous IN
 * endpoints.
 */
static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep)
{
	int cmd_status = 0;
	bool test0;
	bool test1;

	while (dep->combo_num < 2) {
		struct dwc3_gadget_ep_cmd_params params;
		u32 test_frame_number;
		u32 cmd;

		/*
		 * Check if we can start isoc transfer on the next interval or
		 * 4 uframes in the future with BIT[15:14] as dep->combo_num
		 */
		test_frame_number = dep->frame_number & 0x3fff;
		test_frame_number |= dep->combo_num << 14;
		test_frame_number += max_t(u32, 4, dep->interval);

		params.param0 = upper_32_bits(dep->dwc->bounce_addr);
		params.param1 = lower_32_bits(dep->dwc->bounce_addr);

		cmd = DWC3_DEPCMD_STARTTRANSFER;
		cmd |= DWC3_DEPCMD_PARAM(test_frame_number);
		cmd_status = dwc3_send_gadget_ep_cmd(dep, cmd, &params);

		/* Redo if some other failure beside bus-expiry is received */
		if (cmd_status && cmd_status != -EAGAIN) {
			dep->start_cmd_status = 0;
			dep->combo_num = 0;
			return 0;
		}

		/* Store the first test status */
		if (dep->combo_num == 0)
			dep->start_cmd_status = cmd_status;

		dep->combo_num++;

		/*
		 * End the transfer if the START_TRANSFER command is successful
		 * to wait for the next XferNotReady to test the command again
		 */
		if (cmd_status == 0) {
			dwc3_stop_active_transfer(dep, true, true);
			return 0;
		}
	}

	/* test0 and test1 are both completed at this point */
	test0 = (dep->start_cmd_status == 0);
	test1 = (cmd_status == 0);

	if (!test0 && test1)
		dep->combo_num = 1;
	else if (!test0 && !test1)
		dep->combo_num = 2;
	else if (test0 && !test1)
		dep->combo_num = 3;
	else if (test0 && test1)
		dep->combo_num = 0;

	dep->frame_number &= 0x3fff;
	dep->frame_number |= dep->combo_num << 14;
	dep->frame_number += max_t(u32, 4, dep->interval);

	/* Reinitialize test variables */
	dep->start_cmd_status = 0;
	dep->combo_num = 0;

	return __dwc3_gadget_kick_transfer(dep);
}

static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
{
	struct dwc3 *dwc = dep->dwc;
	int ret;
	int i;

	if (list_empty(&dep->pending_list)) {
		dep->flags |= DWC3_EP_PENDING_REQUEST;
		return -EAGAIN;
	}

	if (!dwc->dis_start_transfer_quirk && dwc3_is_usb31(dwc) &&
	    (dwc->revision <= DWC3_USB31_REVISION_160A ||
	     (dwc->revision == DWC3_USB31_REVISION_170A &&
	      dwc->version_type >= DWC31_VERSIONTYPE_EA01 &&
	      dwc->version_type <= DWC31_VERSIONTYPE_EA06))) {

		if (dwc->gadget.speed <= USB_SPEED_HIGH && dep->direction)
			return dwc3_gadget_start_isoc_quirk(dep);
	}

	for (i = 0; i < DWC3_ISOC_MAX_RETRIES; i++) {
		dep->frame_number = DWC3_ALIGN_FRAME(dep, i + 1);

		ret = __dwc3_gadget_kick_transfer(dep);
		if (ret != -EAGAIN)
			break;
	}

	return ret;
}

static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
{
	struct dwc3		*dwc = dep->dwc;

	if (!dep->endpoint.desc) {
		dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n",
				dep->name);
		return -ESHUTDOWN;
	}

	if (WARN(req->dep != dep, "request %pK belongs to '%s'\n",
				&req->request, req->dep->name))
		return -EINVAL;

	if (WARN(req->status < DWC3_REQUEST_STATUS_COMPLETED,
				"%s: request %pK already in flight\n",
				dep->name, &req->request))
		return -EINVAL;

	pm_runtime_get(dwc->dev);

	req->request.actual	= 0;
	req->request.status	= -EINPROGRESS;

	trace_dwc3_ep_queue(req);

	list_add_tail(&req->list, &dep->pending_list);
	req->status = DWC3_REQUEST_STATUS_QUEUED;

	/*
	 * NOTICE: Isochronous endpoints should NEVER be prestarted. We must
	 * wait for a XferNotReady event so we will know what's the current
	 * (micro-)frame number.
	 *
	 * Without this trick, we are very, very likely gonna get Bus Expiry
	 * errors which will force us issue EndTransfer command.
	 */
	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
		if (!(dep->flags & DWC3_EP_PENDING_REQUEST) &&
				!(dep->flags & DWC3_EP_TRANSFER_STARTED))
			return 0;

		if ((dep->flags & DWC3_EP_PENDING_REQUEST)) {
			if (!(dep->flags & DWC3_EP_TRANSFER_STARTED)) {
				return __dwc3_gadget_start_isoc(dep);
			}
		}
	}

	return __dwc3_gadget_kick_transfer(dep);
}

static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
	gfp_t gfp_flags)
{
	struct dwc3_request		*req = to_dwc3_request(request);
	struct dwc3_ep			*dep = to_dwc3_ep(ep);
	struct dwc3			*dwc = dep->dwc;

	unsigned long			flags;

	int				ret;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = __dwc3_gadget_ep_queue(dep, req);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *req)
{
	int i;

	/*
	 * If request was already started, this means we had to
	 * stop the transfer. With that we also need to ignore
	 * all TRBs used by the request, however TRBs can only
	 * be modified after completion of END_TRANSFER
	 * command. So what we do here is that we wait for
	 * END_TRANSFER completion and only after that, we jump
	 * over TRBs by clearing HWO and incrementing dequeue
	 * pointer.
	 */
	for (i = 0; i < req->num_trbs; i++) {
		struct dwc3_trb *trb;

		trb = req->trb + i;
		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
		dwc3_ep_inc_deq(dep);
	}

	req->num_trbs = 0;
}

static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
{
	struct dwc3_request		*req;
	struct dwc3_request		*tmp;

	list_for_each_entry_safe(req, tmp, &dep->cancelled_list, list) {
		dwc3_gadget_ep_skip_trbs(dep, req);
		dwc3_gadget_giveback(dep, req, -ECONNRESET);
	}
}

static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
		struct usb_request *request)
{
	struct dwc3_request		*req = to_dwc3_request(request);
	struct dwc3_request		*r = NULL;

	struct dwc3_ep			*dep = to_dwc3_ep(ep);
	struct dwc3			*dwc = dep->dwc;

	unsigned long			flags;
	int				ret = 0;

	trace_dwc3_ep_dequeue(req);

	spin_lock_irqsave(&dwc->lock, flags);

	list_for_each_entry(r, &dep->pending_list, list) {
		if (r == req)
			break;
	}

	if (r != req) {
		list_for_each_entry(r, &dep->started_list, list) {
			if (r == req)
				break;
		}
		if (r == req) {
			/* wait until it is processed */
			dwc3_stop_active_transfer(dep, true, true);

			if (!r->trb)
				goto out0;

			dwc3_gadget_move_cancelled_request(req);
			if (dep->flags & DWC3_EP_TRANSFER_STARTED)
				goto out0;
			else
				goto out1;
		}
		dev_err(dwc->dev, "request %pK was not queued to %s\n",
				request, ep->name);
		ret = -EINVAL;
		goto out0;
	}

out1:
	dwc3_gadget_giveback(dep, req, -ECONNRESET);

out0:
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
{
	struct dwc3_gadget_ep_cmd_params	params;
	struct dwc3				*dwc = dep->dwc;
	int					ret;

	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
		dev_err(dwc->dev, "%s is of Isochronous type\n", dep->name);
		return -EINVAL;
	}

	memset(&params, 0x00, sizeof(params));

	if (value) {
		struct dwc3_trb *trb;

		unsigned transfer_in_flight;
		unsigned started;

		if (dep->number > 1)
			trb = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
		else
			trb = &dwc->ep0_trb[dep->trb_enqueue];

		transfer_in_flight = trb->ctrl & DWC3_TRB_CTRL_HWO;
		started = !list_empty(&dep->started_list);

		if (!protocol && ((dep->direction && transfer_in_flight) ||
				(!dep->direction && started))) {
			return -EAGAIN;
		}

		ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETSTALL,
				&params);
		if (ret)
			dev_err(dwc->dev, "failed to set STALL on %s\n",
					dep->name);
		else
			dep->flags |= DWC3_EP_STALL;
	} else {

		ret = dwc3_send_clear_stall_ep_cmd(dep);
		if (ret)
			dev_err(dwc->dev, "failed to clear STALL on %s\n",
					dep->name);
		else
			dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
	}

	return ret;
}

static int dwc3_gadget_ep_set_halt(struct usb_ep *ep, int value)
{
	struct dwc3_ep			*dep = to_dwc3_ep(ep);
	struct dwc3			*dwc = dep->dwc;

	unsigned long			flags;

	int				ret;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = __dwc3_gadget_ep_set_halt(dep, value, false);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static int dwc3_gadget_ep_set_wedge(struct usb_ep *ep)
{
	struct dwc3_ep			*dep = to_dwc3_ep(ep);
	struct dwc3			*dwc = dep->dwc;
	unsigned long			flags;
	int				ret;

	spin_lock_irqsave(&dwc->lock, flags);
	dep->flags |= DWC3_EP_WEDGE;

	if (dep->number == 0 || dep->number == 1)
		ret = __dwc3_gadget_ep0_set_halt(ep, 1);
	else
		ret = __dwc3_gadget_ep_set_halt(dep, 1, false);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

/* -------------------------------------------------------------------------- */

static struct usb_endpoint_descriptor dwc3_gadget_ep0_desc = {
	.bLength	= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bmAttributes	= USB_ENDPOINT_XFER_CONTROL,
};

static const struct usb_ep_ops dwc3_gadget_ep0_ops = {
	.enable		= dwc3_gadget_ep0_enable,
	.disable	= dwc3_gadget_ep0_disable,
	.alloc_request	= dwc3_gadget_ep_alloc_request,
	.free_request	= dwc3_gadget_ep_free_request,
	.queue		= dwc3_gadget_ep0_queue,
	.dequeue	= dwc3_gadget_ep_dequeue,
	.set_halt	= dwc3_gadget_ep0_set_halt,
	.set_wedge	= dwc3_gadget_ep_set_wedge,
};

static const struct usb_ep_ops dwc3_gadget_ep_ops = {
	.enable		= dwc3_gadget_ep_enable,
	.disable	= dwc3_gadget_ep_disable,
	.alloc_request	= dwc3_gadget_ep_alloc_request,
	.free_request	= dwc3_gadget_ep_free_request,
	.queue		= dwc3_gadget_ep_queue,
	.dequeue	= dwc3_gadget_ep_dequeue,
	.set_halt	= dwc3_gadget_ep_set_halt,
	.set_wedge	= dwc3_gadget_ep_set_wedge,
};

/* -------------------------------------------------------------------------- */

static int dwc3_gadget_get_frame(struct usb_gadget *g)
{
	struct dwc3		*dwc = gadget_to_dwc(g);

	return __dwc3_gadget_get_frame(dwc);
}

static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
{
	int			retries;

	int			ret;
	u32			reg;

	u8			link_state;
	u8			speed;

	/*
	 * According to the Databook Remote wakeup request should
	 * be issued only when the device is in early suspend state.
	 *
	 * We can check that via USB Link State bits in DSTS register.
	 */
	reg = dwc3_readl(dwc->regs, DWC3_DSTS);

	speed = reg & DWC3_DSTS_CONNECTSPD;
	if ((speed == DWC3_DSTS_SUPERSPEED) ||
	    (speed == DWC3_DSTS_SUPERSPEED_PLUS))
		return 0;

	link_state = DWC3_DSTS_USBLNKST(reg);

	switch (link_state) {
	case DWC3_LINK_STATE_RX_DET:	/* in HS, means Early Suspend */
	case DWC3_LINK_STATE_U3:	/* in HS, means SUSPEND */
		break;
	default:
		return -EINVAL;
	}

	ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV);
	if (ret < 0) {
		dev_err(dwc->dev, "failed to put link in Recovery\n");
		return ret;
	}

	/* Recent versions do this automatically */
	if (dwc->revision < DWC3_REVISION_194A) {
		/* write zeroes to Link Change Request */
		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
		reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
	}

	/* poll until Link State changes to ON */
	retries = 20000;

	while (retries--) {
		reg = dwc3_readl(dwc->regs, DWC3_DSTS);

		/* in HS, means ON */
		if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0)
			break;
	}

	if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) {
		dev_err(dwc->dev, "failed to send remote wakeup\n");
		return -EINVAL;
	}

	return 0;
}

static int dwc3_gadget_wakeup(struct usb_gadget *g)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;
	int			ret;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = __dwc3_gadget_wakeup(dwc);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
		int is_selfpowered)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;

	spin_lock_irqsave(&dwc->lock, flags);
	g->is_selfpowered = !!is_selfpowered;
	spin_unlock_irqrestore(&dwc->lock, flags);

	return 0;
}

static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
{
	u32			reg;
	u32			timeout = 500;

	if (pm_runtime_suspended(dwc->dev))
		return 0;

	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	if (is_on) {
		if (dwc->revision <= DWC3_REVISION_187A) {
			reg &= ~DWC3_DCTL_TRGTULST_MASK;
			reg |= DWC3_DCTL_TRGTULST_RX_DET;
		}

		if (dwc->revision >= DWC3_REVISION_194A)
			reg &= ~DWC3_DCTL_KEEP_CONNECT;
		reg |= DWC3_DCTL_RUN_STOP;

		if (dwc->has_hibernation)
			reg |= DWC3_DCTL_KEEP_CONNECT;

		dwc->pullups_connected = true;
	} else {
		reg &= ~DWC3_DCTL_RUN_STOP;

		if (dwc->has_hibernation && !suspend)
			reg &= ~DWC3_DCTL_KEEP_CONNECT;

		dwc->pullups_connected = false;
	}

	dwc3_writel(dwc->regs, DWC3_DCTL, reg);

	do {
		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
		reg &= DWC3_DSTS_DEVCTRLHLT;
	} while (--timeout && !(!is_on ^ !reg));

	if (!timeout)
		return -ETIMEDOUT;

	return 0;
}

static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;
	int			ret;

	is_on = !!is_on;

	/*
	 * Per databook, when we want to stop the gadget, if a control transfer
	 * is still in process, complete it and get the core into setup phase.
	 */
	if (!is_on && dwc->ep0state != EP0_SETUP_PHASE) {
		reinit_completion(&dwc->ep0_in_setup);

		ret = wait_for_completion_timeout(&dwc->ep0_in_setup,
				msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));
		if (ret == 0) {
			dev_err(dwc->dev, "timed out waiting for SETUP phase\n");
			return -ETIMEDOUT;
		}
	}

	spin_lock_irqsave(&dwc->lock, flags);
	ret = dwc3_gadget_run_stop(dwc, is_on, false);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static void dwc3_gadget_enable_irq(struct dwc3 *dwc)
{
	u32			reg;

	/* Enable all but Start and End of Frame IRQs */
	reg = (DWC3_DEVTEN_VNDRDEVTSTRCVEDEN |
			DWC3_DEVTEN_EVNTOVERFLOWEN |
			DWC3_DEVTEN_CMDCMPLTEN |
			DWC3_DEVTEN_ERRTICERREN |
			DWC3_DEVTEN_WKUPEVTEN |
			DWC3_DEVTEN_CONNECTDONEEN |
			DWC3_DEVTEN_USBRSTEN |
			DWC3_DEVTEN_DISCONNEVTEN);

	if (dwc->revision < DWC3_REVISION_250A)
		reg |= DWC3_DEVTEN_ULSTCNGEN;

	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
}

static void dwc3_gadget_disable_irq(struct dwc3 *dwc)
{
	/* mask all interrupts */
	dwc3_writel(dwc->regs, DWC3_DEVTEN, 0x00);
}

static irqreturn_t dwc3_interrupt(int irq, void *_dwc);
static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc);

/**
 * dwc3_gadget_setup_nump - calculate and initialize NUMP field of %DWC3_DCFG
 * @dwc: pointer to our context structure
 *
 * The following looks like complex but it's actually very simple. In order to
 * calculate the number of packets we can burst at once on OUT transfers, we're
 * gonna use RxFIFO size.
 *
 * To calculate RxFIFO size we need two numbers:
 * MDWIDTH = size, in bits, of the internal memory bus
 * RAM2_DEPTH = depth, in MDWIDTH, of internal RAM2 (where RxFIFO sits)
 *
 * Given these two numbers, the formula is simple:
 *
 * RxFIFO Size = (RAM2_DEPTH * MDWIDTH / 8) - 24 - 16;
 *
 * 24 bytes is for 3x SETUP packets
 * 16 bytes is a clock domain crossing tolerance
 *
 * Given RxFIFO Size, NUMP = RxFIFOSize / 1024;
 */
static void dwc3_gadget_setup_nump(struct dwc3 *dwc)
{
	u32 ram2_depth;
	u32 mdwidth;
	u32 nump;
	u32 reg;

	ram2_depth = DWC3_GHWPARAMS7_RAM2_DEPTH(dwc->hwparams.hwparams7);
	mdwidth = DWC3_GHWPARAMS0_MDWIDTH(dwc->hwparams.hwparams0);

	nump = ((ram2_depth * mdwidth / 8) - 24 - 16) / 1024;
	nump = min_t(u32, nump, 16);

	/* update NumP */
	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
	reg &= ~DWC3_DCFG_NUMP_MASK;
	reg |= nump << DWC3_DCFG_NUMP_SHIFT;
	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
}

static int __dwc3_gadget_start(struct dwc3 *dwc)
{
	struct dwc3_ep		*dep;
	int			ret = 0;
	u32			reg;

	/*
	 * Use IMOD if enabled via dwc->imod_interval. Otherwise, if
	 * the core supports IMOD, disable it.
	 */
	if (dwc->imod_interval) {
		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
	} else if (dwc3_has_imod(dwc)) {
		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), 0);
	}

	/*
	 * We are telling dwc3 that we want to use DCFG.NUMP as ACK TP's NUMP
	 * field instead of letting dwc3 itself calculate that automatically.
	 *
	 * This way, we maximize the chances that we'll be able to get several
	 * bursts of data without going through any sort of endpoint throttling.
	 */
	reg = dwc3_readl(dwc->regs, DWC3_GRXTHRCFG);
	if (dwc3_is_usb31(dwc))
		reg &= ~DWC31_GRXTHRCFG_PKTCNTSEL;
	else
		reg &= ~DWC3_GRXTHRCFG_PKTCNTSEL;

	dwc3_writel(dwc->regs, DWC3_GRXTHRCFG, reg);

	dwc3_gadget_setup_nump(dwc);

	/* Start with SuperSpeed Default */
	dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);

	dep = dwc->eps[0];
	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
	if (ret) {
		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
		goto err0;
	}

	dep = dwc->eps[1];
	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
	if (ret) {
		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
		goto err1;
	}

	/* begin to receive SETUP packets */
	dwc->ep0state = EP0_SETUP_PHASE;
	dwc->link_state = DWC3_LINK_STATE_SS_DIS;
	dwc3_ep0_out_start(dwc);

	dwc3_gadget_enable_irq(dwc);

	return 0;

err1:
	__dwc3_gadget_ep_disable(dwc->eps[0]);

err0:
	return ret;
}

static int dwc3_gadget_start(struct usb_gadget *g,
		struct usb_gadget_driver *driver)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;
	int			ret = 0;
	int			irq;

	irq = dwc->irq_gadget;
	ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
			IRQF_SHARED, "dwc3", dwc->ev_buf);
	if (ret) {
		dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
				irq, ret);
		goto err0;
	}

	spin_lock_irqsave(&dwc->lock, flags);
	if (dwc->gadget_driver) {
		dev_err(dwc->dev, "%s is already bound to %s\n",
				dwc->gadget.name,
				dwc->gadget_driver->driver.name);
		ret = -EBUSY;
		goto err1;
	}

	dwc->gadget_driver	= driver;

	if (pm_runtime_active(dwc->dev))
		__dwc3_gadget_start(dwc);

	spin_unlock_irqrestore(&dwc->lock, flags);

	return 0;

err1:
	spin_unlock_irqrestore(&dwc->lock, flags);
	free_irq(irq, dwc);

err0:
	return ret;
}

static void __dwc3_gadget_stop(struct dwc3 *dwc)
{
	dwc3_gadget_disable_irq(dwc);
	__dwc3_gadget_ep_disable(dwc->eps[0]);
	__dwc3_gadget_ep_disable(dwc->eps[1]);
}

static int dwc3_gadget_stop(struct usb_gadget *g)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;

	spin_lock_irqsave(&dwc->lock, flags);

	if (pm_runtime_suspended(dwc->dev))
		goto out;

	__dwc3_gadget_stop(dwc);

out:
	dwc->gadget_driver	= NULL;
	spin_unlock_irqrestore(&dwc->lock, flags);

	free_irq(dwc->irq_gadget, dwc->ev_buf);

	return 0;
}

static void dwc3_gadget_config_params(struct usb_gadget *g,
				      struct usb_dcd_config_params *params)
{
	struct dwc3		*dwc = gadget_to_dwc(g);

	params->besl_baseline = USB_DEFAULT_BESL_UNSPECIFIED;
	params->besl_deep = USB_DEFAULT_BESL_UNSPECIFIED;

	/* Recommended BESL */
	if (!dwc->dis_enblslpm_quirk) {
		/*
		 * If the recommended BESL baseline is 0 or if the BESL deep is
		 * less than 2, Microsoft's Windows 10 host usb stack will issue
		 * a usb reset immediately after it receives the extended BOS
		 * descriptor and the enumeration will fail. To maintain
		 * compatibility with the Windows' usb stack, let's set the
		 * recommended BESL baseline to 1 and clamp the BESL deep to be
		 * within 2 to 15.
		 */
		params->besl_baseline = 1;
		if (dwc->is_utmi_l1_suspend)
			params->besl_deep =
				clamp_t(u8, dwc->hird_threshold, 2, 15);
	}

	/* U1 Device exit Latency */
	if (dwc->dis_u1_entry_quirk)
		params->bU1devExitLat = 0;
	else
		params->bU1devExitLat = DWC3_DEFAULT_U1_DEV_EXIT_LAT;

	/* U2 Device exit Latency */
	if (dwc->dis_u2_entry_quirk)
		params->bU2DevExitLat = 0;
	else
		params->bU2DevExitLat =
				cpu_to_le16(DWC3_DEFAULT_U2_DEV_EXIT_LAT);
}

static void dwc3_gadget_set_speed(struct usb_gadget *g,
				  enum usb_device_speed speed)
{
	struct dwc3		*dwc = gadget_to_dwc(g);
	unsigned long		flags;
	u32			reg;

	spin_lock_irqsave(&dwc->lock, flags);
	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
	reg &= ~(DWC3_DCFG_SPEED_MASK);

	/*
	 * WORKAROUND: DWC3 revision < 2.20a have an issue
	 * which would cause metastability state on Run/Stop
	 * bit if we try to force the IP to USB2-only mode.
	 *
	 * Because of that, we cannot configure the IP to any
	 * speed other than the SuperSpeed
	 *
	 * Refers to:
	 *
	 * STAR#9000525659: Clock Domain Crossing on DCTL in
	 * USB 2.0 Mode
	 */
	if (dwc->revision < DWC3_REVISION_220A &&
	    !dwc->dis_metastability_quirk) {
		reg |= DWC3_DCFG_SUPERSPEED;
	} else {
		switch (speed) {
		case USB_SPEED_LOW:
			reg |= DWC3_DCFG_LOWSPEED;
			break;
		case USB_SPEED_FULL:
			reg |= DWC3_DCFG_FULLSPEED;
			break;
		case USB_SPEED_HIGH:
			reg |= DWC3_DCFG_HIGHSPEED;
			break;
		case USB_SPEED_SUPER:
			reg |= DWC3_DCFG_SUPERSPEED;
			break;
		case USB_SPEED_SUPER_PLUS:
			if (dwc3_is_usb31(dwc))
				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
			else
				reg |= DWC3_DCFG_SUPERSPEED;
			break;
		default:
			dev_err(dwc->dev, "invalid speed (%d)\n", speed);

			if (dwc->revision & DWC3_REVISION_IS_DWC31)
				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
			else
				reg |= DWC3_DCFG_SUPERSPEED;
		}
	}
	dwc3_writel(dwc->regs, DWC3_DCFG, reg);

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

static const struct usb_gadget_ops dwc3_gadget_ops = {
	.get_frame		= dwc3_gadget_get_frame,
	.wakeup			= dwc3_gadget_wakeup,
	.set_selfpowered	= dwc3_gadget_set_selfpowered,
	.pullup			= dwc3_gadget_pullup,
	.udc_start		= dwc3_gadget_start,
	.udc_stop		= dwc3_gadget_stop,
	.udc_set_speed		= dwc3_gadget_set_speed,
	.get_config_params	= dwc3_gadget_config_params,
};

/* -------------------------------------------------------------------------- */

static int dwc3_gadget_init_control_endpoint(struct dwc3_ep *dep)
{
	struct dwc3 *dwc = dep->dwc;

	usb_ep_set_maxpacket_limit(&dep->endpoint, 512);
	dep->endpoint.maxburst = 1;
	dep->endpoint.ops = &dwc3_gadget_ep0_ops;
	if (!dep->direction)
		dwc->gadget.ep0 = &dep->endpoint;

	dep->endpoint.caps.type_control = true;

	return 0;
}

static int dwc3_gadget_init_in_endpoint(struct dwc3_ep *dep)
{
	struct dwc3 *dwc = dep->dwc;
	int mdwidth;
	int kbytes;
	int size;

	mdwidth = DWC3_MDWIDTH(dwc->hwparams.hwparams0);
	/* MDWIDTH is represented in bits, we need it in bytes */
	mdwidth /= 8;

	size = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1));
	if (dwc3_is_usb31(dwc))
		size = DWC31_GTXFIFOSIZ_TXFDEF(size);
	else
		size = DWC3_GTXFIFOSIZ_TXFDEF(size);

	/* FIFO Depth is in MDWDITH bytes. Multiply */
	size *= mdwidth;

	kbytes = size / 1024;
	if (kbytes == 0)
		kbytes = 1;

	/*
	 * FIFO sizes account an extra MDWIDTH * (kbytes + 1) bytes for
	 * internal overhead. We don't really know how these are used,
	 * but documentation say it exists.
	 */
	size -= mdwidth * (kbytes + 1);
	size /= kbytes;

	usb_ep_set_maxpacket_limit(&dep->endpoint, size);

	dep->endpoint.max_streams = 15;
	dep->endpoint.ops = &dwc3_gadget_ep_ops;
	list_add_tail(&dep->endpoint.ep_list,
			&dwc->gadget.ep_list);
	dep->endpoint.caps.type_iso = true;
	dep->endpoint.caps.type_bulk = true;
	dep->endpoint.caps.type_int = true;

	return dwc3_alloc_trb_pool(dep);
}

static int dwc3_gadget_init_out_endpoint(struct dwc3_ep *dep)
{
	struct dwc3 *dwc = dep->dwc;

	usb_ep_set_maxpacket_limit(&dep->endpoint, 1024);
	dep->endpoint.max_streams = 15;
	dep->endpoint.ops = &dwc3_gadget_ep_ops;
	list_add_tail(&dep->endpoint.ep_list,
			&dwc->gadget.ep_list);
	dep->endpoint.caps.type_iso = true;
	dep->endpoint.caps.type_bulk = true;
	dep->endpoint.caps.type_int = true;

	return dwc3_alloc_trb_pool(dep);
}

static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
{
	struct dwc3_ep			*dep;
	bool				direction = epnum & 1;
	int				ret;
	u8				num = epnum >> 1;

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

	dep->dwc = dwc;
	dep->number = epnum;
	dep->direction = direction;
	dep->regs = dwc->regs + DWC3_DEP_BASE(epnum);
	dwc->eps[epnum] = dep;
	dep->combo_num = 0;
	dep->start_cmd_status = 0;

	snprintf(dep->name, sizeof(dep->name), "ep%u%s", num,
			direction ? "in" : "out");

	dep->endpoint.name = dep->name;

	if (!(dep->number > 1)) {
		dep->endpoint.desc = &dwc3_gadget_ep0_desc;
		dep->endpoint.comp_desc = NULL;
	}

	if (num == 0)
		ret = dwc3_gadget_init_control_endpoint(dep);
	else if (direction)
		ret = dwc3_gadget_init_in_endpoint(dep);
	else
		ret = dwc3_gadget_init_out_endpoint(dep);

	if (ret)
		return ret;

	dep->endpoint.caps.dir_in = direction;
	dep->endpoint.caps.dir_out = !direction;

	INIT_LIST_HEAD(&dep->pending_list);
	INIT_LIST_HEAD(&dep->started_list);
	INIT_LIST_HEAD(&dep->cancelled_list);

	return 0;
}

static int dwc3_gadget_init_endpoints(struct dwc3 *dwc, u8 total)
{
	u8				epnum;

	INIT_LIST_HEAD(&dwc->gadget.ep_list);

	for (epnum = 0; epnum < total; epnum++) {
		int			ret;

		ret = dwc3_gadget_init_endpoint(dwc, epnum);
		if (ret)
			return ret;
	}

	return 0;
}

static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
{
	struct dwc3_ep			*dep;
	u8				epnum;

	for (epnum = 0; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
		dep = dwc->eps[epnum];
		if (!dep)
			continue;
		/*
		 * Physical endpoints 0 and 1 are special; they form the
		 * bi-directional USB endpoint 0.
		 *
		 * For those two physical endpoints, we don't allocate a TRB
		 * pool nor do we add them the endpoints list. Due to that, we
		 * shouldn't do these two operations otherwise we would end up
		 * with all sorts of bugs when removing dwc3.ko.
		 */
		if (epnum != 0 && epnum != 1) {
			dwc3_free_trb_pool(dep);
			list_del(&dep->endpoint.ep_list);
		}

		kfree(dep);
	}
}

/* -------------------------------------------------------------------------- */

static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
		struct dwc3_request *req, struct dwc3_trb *trb,
		const struct dwc3_event_depevt *event, int status, int chain)
{
	unsigned int		count;

	dwc3_ep_inc_deq(dep);

	trace_dwc3_complete_trb(dep, trb);
	req->num_trbs--;

	/*
	 * If we're in the middle of series of chained TRBs and we
	 * receive a short transfer along the way, DWC3 will skip
	 * through all TRBs including the last TRB in the chain (the
	 * where CHN bit is zero. DWC3 will also avoid clearing HWO
	 * bit and SW has to do it manually.
	 *
	 * We're going to do that here to avoid problems of HW trying
	 * to use bogus TRBs for transfers.
	 */
	if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO))
		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

	/*
	 * For isochronous transfers, the first TRB in a service interval must
	 * have the Isoc-First type. Track and report its interval frame number.
	 */
	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
	    (trb->ctrl & DWC3_TRBCTL_ISOCHRONOUS_FIRST)) {
		unsigned int frame_number;

		frame_number = DWC3_TRB_CTRL_GET_SID_SOFN(trb->ctrl);
		frame_number &= ~(dep->interval - 1);
		req->request.frame_number = frame_number;
	}

	/*
	 * If we're dealing with unaligned size OUT transfer, we will be left
	 * with one TRB pending in the ring. We need to manually clear HWO bit
	 * from that TRB.
	 */

	if (req->needs_extra_trb && !(trb->ctrl & DWC3_TRB_CTRL_CHN)) {
		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
		return 1;
	}

	count = trb->size & DWC3_TRB_SIZE_MASK;
	req->remaining += count;

	if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
		return 1;

	if (event->status & DEPEVT_STATUS_SHORT && !chain)
		return 1;

	if (event->status & DEPEVT_STATUS_IOC)
		return 1;

	return 0;
}

static int dwc3_gadget_ep_reclaim_trb_sg(struct dwc3_ep *dep,
		struct dwc3_request *req, const struct dwc3_event_depevt *event,
		int status)
{
	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];
	struct scatterlist *sg = req->sg;
	struct scatterlist *s;
	unsigned int pending = req->num_pending_sgs;
	unsigned int i;
	int ret = 0;

	for_each_sg(sg, s, pending, i) {
		trb = &dep->trb_pool[dep->trb_dequeue];

		if (trb->ctrl & DWC3_TRB_CTRL_HWO)
			break;

		req->sg = sg_next(s);
		req->num_pending_sgs--;

		ret = dwc3_gadget_ep_reclaim_completed_trb(dep, req,
				trb, event, status, true);
		if (ret)
			break;
	}

	return ret;
}

static int dwc3_gadget_ep_reclaim_trb_linear(struct dwc3_ep *dep,
		struct dwc3_request *req, const struct dwc3_event_depevt *event,
		int status)
{
	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];

	return dwc3_gadget_ep_reclaim_completed_trb(dep, req, trb,
			event, status, false);
}

static bool dwc3_gadget_ep_request_completed(struct dwc3_request *req)
{
	return req->request.actual == req->request.length;
}

static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
		const struct dwc3_event_depevt *event,
		struct dwc3_request *req, int status)
{
	int ret;

	if (req->num_pending_sgs)
		ret = dwc3_gadget_ep_reclaim_trb_sg(dep, req, event,
				status);
	else
		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
				status);

	if (req->needs_extra_trb) {
		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
				status);
		req->needs_extra_trb = false;
	}

	req->request.actual = req->request.length - req->remaining;

	if (!dwc3_gadget_ep_request_completed(req) &&
			req->num_pending_sgs) {
		__dwc3_gadget_kick_transfer(dep);
		goto out;
	}

	dwc3_gadget_giveback(dep, req, status);

out:
	return ret;
}

static void dwc3_gadget_ep_cleanup_completed_requests(struct dwc3_ep *dep,
		const struct dwc3_event_depevt *event, int status)
{
	struct dwc3_request	*req;
	struct dwc3_request	*tmp;

	list_for_each_entry_safe(req, tmp, &dep->started_list, list) {
		int ret;

		ret = dwc3_gadget_ep_cleanup_completed_request(dep, event,
				req, status);
		if (ret)
			break;
	}
}

static void dwc3_gadget_endpoint_frame_from_event(struct dwc3_ep *dep,
		const struct dwc3_event_depevt *event)
{
	dep->frame_number = event->parameters;
}

static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
		const struct dwc3_event_depevt *event)
{
	struct dwc3		*dwc = dep->dwc;
	unsigned		status = 0;
	bool			stop = false;

	dwc3_gadget_endpoint_frame_from_event(dep, event);

	if (event->status & DEPEVT_STATUS_BUSERR)
		status = -ECONNRESET;

	if (event->status & DEPEVT_STATUS_MISSED_ISOC) {
		status = -EXDEV;

		if (list_empty(&dep->started_list))
			stop = true;
	}

	dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);

	if (stop) {
		dwc3_stop_active_transfer(dep, true, true);
		dep->flags = DWC3_EP_ENABLED;
	}

	/*
	 * WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
	 * See dwc3_gadget_linksts_change_interrupt() for 1st half.
	 */
	if (dwc->revision < DWC3_REVISION_183A) {
		u32		reg;
		int		i;

		for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
			dep = dwc->eps[i];

			if (!(dep->flags & DWC3_EP_ENABLED))
				continue;

			if (!list_empty(&dep->started_list))
				return;
		}

		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
		reg |= dwc->u1u2;
		dwc3_writel(dwc->regs, DWC3_DCTL, reg);

		dwc->u1u2 = 0;
	}
}

static void dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep,
		const struct dwc3_event_depevt *event)
{
	dwc3_gadget_endpoint_frame_from_event(dep, event);
	(void) __dwc3_gadget_start_isoc(dep);
}

static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	struct dwc3_ep		*dep;
	u8			epnum = event->endpoint_number;
	u8			cmd;

	dep = dwc->eps[epnum];

	if (!(dep->flags & DWC3_EP_ENABLED)) {
		if (!(dep->flags & DWC3_EP_TRANSFER_STARTED))
			return;

		/* Handle only EPCMDCMPLT when EP disabled */
		if (event->endpoint_event != DWC3_DEPEVT_EPCMDCMPLT)
			return;
	}

	if (epnum == 0 || epnum == 1) {
		dwc3_ep0_interrupt(dwc, event);
		return;
	}

	switch (event->endpoint_event) {
	case DWC3_DEPEVT_XFERINPROGRESS:
		dwc3_gadget_endpoint_transfer_in_progress(dep, event);
		break;
	case DWC3_DEPEVT_XFERNOTREADY:
		dwc3_gadget_endpoint_transfer_not_ready(dep, event);
		break;
	case DWC3_DEPEVT_EPCMDCMPLT:
		cmd = DEPEVT_PARAMETER_CMD(event->parameters);

		if (cmd == DWC3_DEPCMD_ENDTRANSFER) {
			dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
		}
		break;
	case DWC3_DEPEVT_STREAMEVT:
	case DWC3_DEPEVT_XFERCOMPLETE:
	case DWC3_DEPEVT_RXTXFIFOEVT:
		break;
	}
}

static void dwc3_disconnect_gadget(struct dwc3 *dwc)
{
	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
		spin_unlock(&dwc->lock);
		dwc->gadget_driver->disconnect(&dwc->gadget);
		spin_lock(&dwc->lock);
	}
}

static void dwc3_suspend_gadget(struct dwc3 *dwc)
{
	if (dwc->gadget_driver && dwc->gadget_driver->suspend) {
		spin_unlock(&dwc->lock);
		dwc->gadget_driver->suspend(&dwc->gadget);
		spin_lock(&dwc->lock);
	}
}

static void dwc3_resume_gadget(struct dwc3 *dwc)
{
	if (dwc->gadget_driver && dwc->gadget_driver->resume) {
		spin_unlock(&dwc->lock);
		dwc->gadget_driver->resume(&dwc->gadget);
		spin_lock(&dwc->lock);
	}
}

static void dwc3_reset_gadget(struct dwc3 *dwc)
{
	if (!dwc->gadget_driver)
		return;

	if (dwc->gadget.speed != USB_SPEED_UNKNOWN) {
		spin_unlock(&dwc->lock);
		usb_gadget_udc_reset(&dwc->gadget, dwc->gadget_driver);
		spin_lock(&dwc->lock);
	}
}

static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
	bool interrupt)
{
	struct dwc3 *dwc = dep->dwc;
	struct dwc3_gadget_ep_cmd_params params;
	u32 cmd;
	int ret;

	if (!(dep->flags & DWC3_EP_TRANSFER_STARTED))
		return;

	/*
	 * NOTICE: We are violating what the Databook says about the
	 * EndTransfer command. Ideally we would _always_ wait for the
	 * EndTransfer Command Completion IRQ, but that's causing too
	 * much trouble synchronizing between us and gadget driver.
	 *
	 * We have discussed this with the IP Provider and it was
	 * suggested to giveback all requests here, but give HW some
	 * extra time to synchronize with the interconnect. We're using
	 * an arbitrary 100us delay for that.
	 *
	 * Note also that a similar handling was tested by Synopsys
	 * (thanks a lot Paul) and nothing bad has come out of it.
	 * In short, what we're doing is:
	 *
	 * - Issue EndTransfer WITH CMDIOC bit set
	 * - Wait 100us
	 *
	 * As of IP version 3.10a of the DWC_usb3 IP, the controller
	 * supports a mode to work around the above limitation. The
	 * software can poll the CMDACT bit in the DEPCMD register
	 * after issuing a EndTransfer command. This mode is enabled
	 * by writing GUCTL2[14]. This polling is already done in the
	 * dwc3_send_gadget_ep_cmd() function so if the mode is
	 * enabled, the EndTransfer command will have completed upon
	 * returning from this function and we don't need to delay for
	 * 100us.
	 *
	 * This mode is NOT available on the DWC_usb31 IP.
	 */

	cmd = DWC3_DEPCMD_ENDTRANSFER;
	cmd |= force ? DWC3_DEPCMD_HIPRI_FORCERM : 0;
	cmd |= interrupt ? DWC3_DEPCMD_CMDIOC : 0;
	cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
	memset(&params, 0, sizeof(params));
	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
	WARN_ON_ONCE(ret);
	dep->resource_index = 0;

	if (dwc3_is_usb31(dwc) || dwc->revision < DWC3_REVISION_310A)
		udelay(100);
}

static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
{
	u32 epnum;

	for (epnum = 1; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
		struct dwc3_ep *dep;
		int ret;

		dep = dwc->eps[epnum];
		if (!dep)
			continue;

		if (!(dep->flags & DWC3_EP_STALL))
			continue;

		dep->flags &= ~DWC3_EP_STALL;

		ret = dwc3_send_clear_stall_ep_cmd(dep);
		WARN_ON_ONCE(ret);
	}
}

static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
{
	int			reg;

	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	reg &= ~DWC3_DCTL_INITU1ENA;
	dwc3_writel(dwc->regs, DWC3_DCTL, reg);

	reg &= ~DWC3_DCTL_INITU2ENA;
	dwc3_writel(dwc->regs, DWC3_DCTL, reg);

	dwc3_disconnect_gadget(dwc);

	dwc->gadget.speed = USB_SPEED_UNKNOWN;
	dwc->setup_packet_pending = false;
	usb_gadget_set_state(&dwc->gadget, USB_STATE_NOTATTACHED);

	dwc->connected = false;
}

static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
{
	u32			reg;

	dwc->connected = true;

	/*
	 * WORKAROUND: DWC3 revisions <1.88a have an issue which
	 * would cause a missing Disconnect Event if there's a
	 * pending Setup Packet in the FIFO.
	 *
	 * There's no suggested workaround on the official Bug
	 * report, which states that "unless the driver/application
	 * is doing any special handling of a disconnect event,
	 * there is no functional issue".
	 *
	 * Unfortunately, it turns out that we _do_ some special
	 * handling of a disconnect event, namely complete all
	 * pending transfers, notify gadget driver of the
	 * disconnection, and so on.
	 *
	 * Our suggested workaround is to follow the Disconnect
	 * Event steps here, instead, based on a setup_packet_pending
	 * flag. Such flag gets set whenever we have a SETUP_PENDING
	 * status for EP0 TRBs and gets cleared on XferComplete for the
	 * same endpoint.
	 *
	 * Refers to:
	 *
	 * STAR#9000466709: RTL: Device : Disconnect event not
	 * generated if setup packet pending in FIFO
	 */
	if (dwc->revision < DWC3_REVISION_188A) {
		if (dwc->setup_packet_pending)
			dwc3_gadget_disconnect_interrupt(dwc);
	}

	dwc3_reset_gadget(dwc);

	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
	dwc->test_mode = false;
	dwc3_clear_stall_all_ep(dwc);

	/* Reset device address to zero */
	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
}

static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
{
	struct dwc3_ep		*dep;
	int			ret;
	u32			reg;
	u8			speed;

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
	speed = reg & DWC3_DSTS_CONNECTSPD;
	dwc->speed = speed;

	/*
	 * RAMClkSel is reset to 0 after USB reset, so it must be reprogrammed
	 * each time on Connect Done.
	 *
	 * Currently we always use the reset value. If any platform
	 * wants to set this to a different value, we need to add a
	 * setting and update GCTL.RAMCLKSEL here.
	 */

	switch (speed) {
	case DWC3_DSTS_SUPERSPEED_PLUS:
		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
		dwc->gadget.ep0->maxpacket = 512;
		dwc->gadget.speed = USB_SPEED_SUPER_PLUS;
		break;
	case DWC3_DSTS_SUPERSPEED:
		/*
		 * WORKAROUND: DWC3 revisions <1.90a have an issue which
		 * would cause a missing USB3 Reset event.
		 *
		 * In such situations, we should force a USB3 Reset
		 * event by calling our dwc3_gadget_reset_interrupt()
		 * routine.
		 *
		 * Refers to:
		 *
		 * STAR#9000483510: RTL: SS : USB3 reset event may
		 * not be generated always when the link enters poll
		 */
		if (dwc->revision < DWC3_REVISION_190A)
			dwc3_gadget_reset_interrupt(dwc);

		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
		dwc->gadget.ep0->maxpacket = 512;
		dwc->gadget.speed = USB_SPEED_SUPER;
		break;
	case DWC3_DSTS_HIGHSPEED:
		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
		dwc->gadget.ep0->maxpacket = 64;
		dwc->gadget.speed = USB_SPEED_HIGH;
		break;
	case DWC3_DSTS_FULLSPEED:
		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
		dwc->gadget.ep0->maxpacket = 64;
		dwc->gadget.speed = USB_SPEED_FULL;
		break;
	case DWC3_DSTS_LOWSPEED:
		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(8);
		dwc->gadget.ep0->maxpacket = 8;
		dwc->gadget.speed = USB_SPEED_LOW;
		break;
	}

	dwc->eps[1]->endpoint.maxpacket = dwc->gadget.ep0->maxpacket;

	/* Enable USB2 LPM Capability */

	if ((dwc->revision > DWC3_REVISION_194A) &&
	    (speed != DWC3_DSTS_SUPERSPEED) &&
	    (speed != DWC3_DSTS_SUPERSPEED_PLUS)) {
		reg = dwc3_readl(dwc->regs, DWC3_DCFG);
		reg |= DWC3_DCFG_LPM_CAP;
		dwc3_writel(dwc->regs, DWC3_DCFG, reg);

		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
		reg &= ~(DWC3_DCTL_HIRD_THRES_MASK | DWC3_DCTL_L1_HIBER_EN);

		reg |= DWC3_DCTL_HIRD_THRES(dwc->hird_threshold |
					    (dwc->is_utmi_l1_suspend << 4));

		/*
		 * When dwc3 revisions >= 2.40a, LPM Erratum is enabled and
		 * DCFG.LPMCap is set, core responses with an ACK and the
		 * BESL value in the LPM token is less than or equal to LPM
		 * NYET threshold.
		 */
		WARN_ONCE(dwc->revision < DWC3_REVISION_240A
				&& dwc->has_lpm_erratum,
				"LPM Erratum not available on dwc3 revisions < 2.40a\n");

		if (dwc->has_lpm_erratum && dwc->revision >= DWC3_REVISION_240A)
			reg |= DWC3_DCTL_NYET_THRES(dwc->lpm_nyet_threshold);

		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
	} else {
		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
		reg &= ~DWC3_DCTL_HIRD_THRES_MASK;
		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
	}

	dep = dwc->eps[0];
	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
	if (ret) {
		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
		return;
	}

	dep = dwc->eps[1];
	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
	if (ret) {
		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
		return;
	}

	/*
	 * Configure PHY via GUSB3PIPECTLn if required.
	 *
	 * Update GTXFIFOSIZn
	 *
	 * In both cases reset values should be sufficient.
	 */
}

static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
{
	/*
	 * TODO take core out of low power mode when that's
	 * implemented.
	 */

	if (dwc->gadget_driver && dwc->gadget_driver->resume) {
		spin_unlock(&dwc->lock);
		dwc->gadget_driver->resume(&dwc->gadget);
		spin_lock(&dwc->lock);
	}
}

static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
		unsigned int evtinfo)
{
	enum dwc3_link_state	next = evtinfo & DWC3_LINK_STATE_MASK;
	unsigned int		pwropt;

	/*
	 * WORKAROUND: DWC3 < 2.50a have an issue when configured without
	 * Hibernation mode enabled which would show up when device detects
	 * host-initiated U3 exit.
	 *
	 * In that case, device will generate a Link State Change Interrupt
	 * from U3 to RESUME which is only necessary if Hibernation is
	 * configured in.
	 *
	 * There are no functional changes due to such spurious event and we
	 * just need to ignore it.
	 *
	 * Refers to:
	 *
	 * STAR#9000570034 RTL: SS Resume event generated in non-Hibernation
	 * operational mode
	 */
	pwropt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1);
	if ((dwc->revision < DWC3_REVISION_250A) &&
			(pwropt != DWC3_GHWPARAMS1_EN_PWROPT_HIB)) {
		if ((dwc->link_state == DWC3_LINK_STATE_U3) &&
				(next == DWC3_LINK_STATE_RESUME)) {
			return;
		}
	}

	/*
	 * WORKAROUND: DWC3 Revisions <1.83a have an issue which, depending
	 * on the link partner, the USB session might do multiple entry/exit
	 * of low power states before a transfer takes place.
	 *
	 * Due to this problem, we might experience lower throughput. The
	 * suggested workaround is to disable DCTL[12:9] bits if we're
	 * transitioning from U1/U2 to U0 and enable those bits again
	 * after a transfer completes and there are no pending transfers
	 * on any of the enabled endpoints.
	 *
	 * This is the first half of that workaround.
	 *
	 * Refers to:
	 *
	 * STAR#9000446952: RTL: Device SS : if U1/U2 ->U0 takes >128us
	 * core send LGO_Ux entering U0
	 */
	if (dwc->revision < DWC3_REVISION_183A) {
		if (next == DWC3_LINK_STATE_U0) {
			u32	u1u2;
			u32	reg;

			switch (dwc->link_state) {
			case DWC3_LINK_STATE_U1:
			case DWC3_LINK_STATE_U2:
				reg = dwc3_readl(dwc->regs, DWC3_DCTL);
				u1u2 = reg & (DWC3_DCTL_INITU2ENA
						| DWC3_DCTL_ACCEPTU2ENA
						| DWC3_DCTL_INITU1ENA
						| DWC3_DCTL_ACCEPTU1ENA);

				if (!dwc->u1u2)
					dwc->u1u2 = reg & u1u2;

				reg &= ~u1u2;

				dwc3_writel(dwc->regs, DWC3_DCTL, reg);
				break;
			default:
				/* do nothing */
				break;
			}
		}
	}

	switch (next) {
	case DWC3_LINK_STATE_U1:
		if (dwc->speed == USB_SPEED_SUPER)
			dwc3_suspend_gadget(dwc);
		break;
	case DWC3_LINK_STATE_U2:
	case DWC3_LINK_STATE_U3:
		dwc3_suspend_gadget(dwc);
		break;
	case DWC3_LINK_STATE_RESUME:
		dwc3_resume_gadget(dwc);
		break;
	default:
		/* do nothing */
		break;
	}

	dwc->link_state = next;
}

static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,
					  unsigned int evtinfo)
{
	enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK;

	if (dwc->link_state != next && next == DWC3_LINK_STATE_U3)
		dwc3_suspend_gadget(dwc);

	dwc->link_state = next;
}

static void dwc3_gadget_hibernation_interrupt(struct dwc3 *dwc,
		unsigned int evtinfo)
{
	unsigned int is_ss = evtinfo & BIT(4);

	/*
	 * WORKAROUND: DWC3 revison 2.20a with hibernation support
	 * have a known issue which can cause USB CV TD.9.23 to fail
	 * randomly.
	 *
	 * Because of this issue, core could generate bogus hibernation
	 * events which SW needs to ignore.
	 *
	 * Refers to:
	 *
	 * STAR#9000546576: Device Mode Hibernation: Issue in USB 2.0
	 * Device Fallback from SuperSpeed
	 */
	if (is_ss ^ (dwc->speed == USB_SPEED_SUPER))
		return;

	/* enter hibernation here */
}

static void dwc3_gadget_interrupt(struct dwc3 *dwc,
		const struct dwc3_event_devt *event)
{
	switch (event->type) {
	case DWC3_DEVICE_EVENT_DISCONNECT:
		dwc3_gadget_disconnect_interrupt(dwc);
		break;
	case DWC3_DEVICE_EVENT_RESET:
		dwc3_gadget_reset_interrupt(dwc);
		break;
	case DWC3_DEVICE_EVENT_CONNECT_DONE:
		dwc3_gadget_conndone_interrupt(dwc);
		break;
	case DWC3_DEVICE_EVENT_WAKEUP:
		dwc3_gadget_wakeup_interrupt(dwc);
		break;
	case DWC3_DEVICE_EVENT_HIBER_REQ:
		if (dev_WARN_ONCE(dwc->dev, !dwc->has_hibernation,
					"unexpected hibernation event\n"))
			break;

		dwc3_gadget_hibernation_interrupt(dwc, event->event_info);
		break;
	case DWC3_DEVICE_EVENT_LINK_STATUS_CHANGE:
		dwc3_gadget_linksts_change_interrupt(dwc, event->event_info);
		break;
	case DWC3_DEVICE_EVENT_EOPF:
		/* It changed to be suspend event for version 2.30a and above */
		if (dwc->revision >= DWC3_REVISION_230A) {
			/*
			 * Ignore suspend event until the gadget enters into
			 * USB_STATE_CONFIGURED state.
			 */
			if (dwc->gadget.state >= USB_STATE_CONFIGURED)
				dwc3_gadget_suspend_interrupt(dwc,
						event->event_info);
		}
		break;
	case DWC3_DEVICE_EVENT_SOF:
	case DWC3_DEVICE_EVENT_ERRATIC_ERROR:
	case DWC3_DEVICE_EVENT_CMD_CMPL:
	case DWC3_DEVICE_EVENT_OVERFLOW:
		break;
	default:
		dev_WARN(dwc->dev, "UNKNOWN IRQ %d\n", event->type);
	}
}

static void dwc3_process_event_entry(struct dwc3 *dwc,
		const union dwc3_event *event)
{
	trace_dwc3_event(event->raw, dwc);

	if (!event->type.is_devspec)
		dwc3_endpoint_interrupt(dwc, &event->depevt);
	else if (event->type.type == DWC3_EVENT_TYPE_DEV)
		dwc3_gadget_interrupt(dwc, &event->devt);
	else
		dev_err(dwc->dev, "UNKNOWN IRQ type %d\n", event->raw);
}

static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
{
	struct dwc3 *dwc = evt->dwc;
	irqreturn_t ret = IRQ_NONE;
	int left;
	u32 reg;

	left = evt->count;

	if (!(evt->flags & DWC3_EVENT_PENDING))
		return IRQ_NONE;

	while (left > 0) {
		union dwc3_event event;

		event.raw = *(u32 *) (evt->cache + evt->lpos);

		dwc3_process_event_entry(dwc, &event);

		/*
		 * FIXME we wrap around correctly to the next entry as
		 * almost all entries are 4 bytes in size. There is one
		 * entry which has 12 bytes which is a regular entry
		 * followed by 8 bytes data. ATM I don't know how
		 * things are organized if we get next to the a
		 * boundary so I worry about that once we try to handle
		 * that.
		 */
		evt->lpos = (evt->lpos + 4) % evt->length;
		left -= 4;
	}

	evt->count = 0;
	evt->flags &= ~DWC3_EVENT_PENDING;
	ret = IRQ_HANDLED;

	/* Unmask interrupt */
	reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
	reg &= ~DWC3_GEVNTSIZ_INTMASK;
	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);

	if (dwc->imod_interval) {
		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
	}

	return ret;
}

static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt)
{
	struct dwc3_event_buffer *evt = _evt;
	struct dwc3 *dwc = evt->dwc;
	unsigned long flags;
	irqreturn_t ret = IRQ_NONE;

	spin_lock_irqsave(&dwc->lock, flags);
	ret = dwc3_process_event_buf(evt);
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
{
	struct dwc3 *dwc = evt->dwc;
	u32 amount;
	u32 count;
	u32 reg;

	if (pm_runtime_suspended(dwc->dev)) {
		pm_runtime_get(dwc->dev);
		disable_irq_nosync(dwc->irq_gadget);
		dwc->pending_events = true;
		return IRQ_HANDLED;
	}

	/*
	 * With PCIe legacy interrupt, test shows that top-half irq handler can
	 * be called again after HW interrupt deassertion. Check if bottom-half
	 * irq event handler completes before caching new event to prevent
	 * losing events.
	 */
	if (evt->flags & DWC3_EVENT_PENDING)
		return IRQ_HANDLED;

	count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
	count &= DWC3_GEVNTCOUNT_MASK;
	if (!count)
		return IRQ_NONE;

	evt->count = count;
	evt->flags |= DWC3_EVENT_PENDING;

	/* Mask interrupt */
	reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
	reg |= DWC3_GEVNTSIZ_INTMASK;
	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);

	amount = min(count, evt->length - evt->lpos);
	memcpy(evt->cache + evt->lpos, evt->buf + evt->lpos, amount);

	if (amount < count)
		memcpy(evt->cache, evt->buf, count - amount);

	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count);

	return IRQ_WAKE_THREAD;
}

static irqreturn_t dwc3_interrupt(int irq, void *_evt)
{
	struct dwc3_event_buffer	*evt = _evt;

	return dwc3_check_event_buf(evt);
}

static int dwc3_gadget_get_irq(struct dwc3 *dwc)
{
	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
	int irq;

	irq = platform_get_irq_byname_optional(dwc3_pdev, "peripheral");
	if (irq > 0)
		goto out;

	if (irq == -EPROBE_DEFER)
		goto out;

	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
	if (irq > 0)
		goto out;

	if (irq == -EPROBE_DEFER)
		goto out;

	irq = platform_get_irq(dwc3_pdev, 0);
	if (irq > 0)
		goto out;

	if (!irq)
		irq = -EINVAL;

out:
	return irq;
}

/**
 * dwc3_gadget_init - initializes gadget related registers
 * @dwc: pointer to our controller context structure
 *
 * Returns 0 on success otherwise negative errno.
 */
int dwc3_gadget_init(struct dwc3 *dwc)
{
	int ret;
	int irq;

	irq = dwc3_gadget_get_irq(dwc);
	if (irq < 0) {
		ret = irq;
		goto err0;
	}

	dwc->irq_gadget = irq;

	dwc->ep0_trb = dma_alloc_coherent(dwc->sysdev,
					  sizeof(*dwc->ep0_trb) * 2,
					  &dwc->ep0_trb_addr, GFP_KERNEL);
	if (!dwc->ep0_trb) {
		dev_err(dwc->dev, "failed to allocate ep0 trb\n");
		ret = -ENOMEM;
		goto err0;
	}

	dwc->setup_buf = kzalloc(DWC3_EP0_SETUP_SIZE, GFP_KERNEL);
	if (!dwc->setup_buf) {
		ret = -ENOMEM;
		goto err1;
	}

	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
			&dwc->bounce_addr, GFP_KERNEL);
	if (!dwc->bounce) {
		ret = -ENOMEM;
		goto err2;
	}

	init_completion(&dwc->ep0_in_setup);

	dwc->gadget.ops			= &dwc3_gadget_ops;
	dwc->gadget.speed		= USB_SPEED_UNKNOWN;
	dwc->gadget.sg_supported	= true;
	dwc->gadget.name		= "dwc3-gadget";
	dwc->gadget.lpm_capable		= true;

	/*
	 * FIXME We might be setting max_speed to <SUPER, however versions
	 * <2.20a of dwc3 have an issue with metastability (documented
	 * elsewhere in this driver) which tells us we can't set max speed to
	 * anything lower than SUPER.
	 *
	 * Because gadget.max_speed is only used by composite.c and function
	 * drivers (i.e. it won't go into dwc3's registers) we are allowing this
	 * to happen so we avoid sending SuperSpeed Capability descriptor
	 * together with our BOS descriptor as that could confuse host into
	 * thinking we can handle super speed.
	 *
	 * Note that, in fact, we won't even support GetBOS requests when speed
	 * is less than super speed because we don't have means, yet, to tell
	 * composite.c that we are USB 2.0 + LPM ECN.
	 */
	if (dwc->revision < DWC3_REVISION_220A &&
	    !dwc->dis_metastability_quirk)
		dev_info(dwc->dev, "changing max_speed on rev %08x\n",
				dwc->revision);

	dwc->gadget.max_speed		= dwc->maximum_speed;

	/*
	 * REVISIT: Here we should clear all pending IRQs to be
	 * sure we're starting from a well known location.
	 */

	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
	if (ret)
		goto err3;

	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
	if (ret) {
		dev_err(dwc->dev, "failed to register udc\n");
		goto err4;
	}

	dwc3_gadget_set_speed(&dwc->gadget, dwc->maximum_speed);

	return 0;

err4:
	dwc3_gadget_free_endpoints(dwc);

err3:
	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
			dwc->bounce_addr);

err2:
	kfree(dwc->setup_buf);

err1:
	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
			dwc->ep0_trb, dwc->ep0_trb_addr);

err0:
	return ret;
}

/* -------------------------------------------------------------------------- */

void dwc3_gadget_exit(struct dwc3 *dwc)
{
	usb_del_gadget_udc(&dwc->gadget);
	dwc3_gadget_free_endpoints(dwc);
	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
			  dwc->bounce_addr);
	kfree(dwc->setup_buf);
	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
			  dwc->ep0_trb, dwc->ep0_trb_addr);
}

int dwc3_gadget_suspend(struct dwc3 *dwc)
{
	if (!dwc->gadget_driver)
		return 0;

	dwc3_gadget_run_stop(dwc, false, false);
	dwc3_disconnect_gadget(dwc);
	__dwc3_gadget_stop(dwc);

	return 0;
}

int dwc3_gadget_resume(struct dwc3 *dwc)
{
	int			ret;

	if (!dwc->gadget_driver)
		return 0;

	ret = __dwc3_gadget_start(dwc);
	if (ret < 0)
		goto err0;

	ret = dwc3_gadget_run_stop(dwc, true, false);
	if (ret < 0)
		goto err1;

	return 0;

err1:
	__dwc3_gadget_stop(dwc);

err0:
	return ret;
}

void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
{
	if (dwc->pending_events) {
		dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
		dwc->pending_events = false;
		enable_irq(dwc->irq_gadget);
	}
}