Free Electrons

Embedded Linux Experts

   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
/*
 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Standard functionality for the common clock API.  See Documentation/clk.txt
 */

#include <linux/clk-provider.h>
#include <linux/clk/clk-conf.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/clkdev.h>

#include "clk.h"

static DEFINE_SPINLOCK(enable_lock);
static DEFINE_MUTEX(prepare_lock);

static struct task_struct *prepare_owner;
static struct task_struct *enable_owner;

static int prepare_refcnt;
static int enable_refcnt;

static HLIST_HEAD(clk_root_list);
static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);

/***    private data structures    ***/

struct clk_core {
	const char		*name;
	const struct clk_ops	*ops;
	struct clk_hw		*hw;
	struct module		*owner;
	struct clk_core		*parent;
	const char		**parent_names;
	struct clk_core		**parents;
	u8			num_parents;
	u8			new_parent_index;
	unsigned long		rate;
	unsigned long		req_rate;
	unsigned long		new_rate;
	struct clk_core		*new_parent;
	struct clk_core		*new_child;
	unsigned long		flags;
	unsigned int		enable_count;
	unsigned int		prepare_count;
	unsigned long		accuracy;
	int			phase;
	struct hlist_head	children;
	struct hlist_node	child_node;
	struct hlist_head	clks;
	unsigned int		notifier_count;
#ifdef CONFIG_DEBUG_FS
	struct dentry		*dentry;
	struct hlist_node	debug_node;
#endif
	struct kref		ref;
};

#define CREATE_TRACE_POINTS
#include <trace/events/clk.h>

struct clk {
	struct clk_core	*core;
	const char *dev_id;
	const char *con_id;
	unsigned long min_rate;
	unsigned long max_rate;
	struct hlist_node clks_node;
};

/***           locking             ***/
static void clk_prepare_lock(void)
{
	if (!mutex_trylock(&prepare_lock)) {
		if (prepare_owner == current) {
			prepare_refcnt++;
			return;
		}
		mutex_lock(&prepare_lock);
	}
	WARN_ON_ONCE(prepare_owner != NULL);
	WARN_ON_ONCE(prepare_refcnt != 0);
	prepare_owner = current;
	prepare_refcnt = 1;
}

static void clk_prepare_unlock(void)
{
	WARN_ON_ONCE(prepare_owner != current);
	WARN_ON_ONCE(prepare_refcnt == 0);

	if (--prepare_refcnt)
		return;
	prepare_owner = NULL;
	mutex_unlock(&prepare_lock);
}

static unsigned long clk_enable_lock(void)
{
	unsigned long flags;

	if (!spin_trylock_irqsave(&enable_lock, flags)) {
		if (enable_owner == current) {
			enable_refcnt++;
			return flags;
		}
		spin_lock_irqsave(&enable_lock, flags);
	}
	WARN_ON_ONCE(enable_owner != NULL);
	WARN_ON_ONCE(enable_refcnt != 0);
	enable_owner = current;
	enable_refcnt = 1;
	return flags;
}

static void clk_enable_unlock(unsigned long flags)
{
	WARN_ON_ONCE(enable_owner != current);
	WARN_ON_ONCE(enable_refcnt == 0);

	if (--enable_refcnt)
		return;
	enable_owner = NULL;
	spin_unlock_irqrestore(&enable_lock, flags);
}

static bool clk_core_is_prepared(struct clk_core *core)
{
	/*
	 * .is_prepared is optional for clocks that can prepare
	 * fall back to software usage counter if it is missing
	 */
	if (!core->ops->is_prepared)
		return core->prepare_count;

	return core->ops->is_prepared(core->hw);
}

static bool clk_core_is_enabled(struct clk_core *core)
{
	/*
	 * .is_enabled is only mandatory for clocks that gate
	 * fall back to software usage counter if .is_enabled is missing
	 */
	if (!core->ops->is_enabled)
		return core->enable_count;

	return core->ops->is_enabled(core->hw);
}

static void clk_unprepare_unused_subtree(struct clk_core *core)
{
	struct clk_core *child;

	lockdep_assert_held(&prepare_lock);

	hlist_for_each_entry(child, &core->children, child_node)
		clk_unprepare_unused_subtree(child);

	if (core->prepare_count)
		return;

	if (core->flags & CLK_IGNORE_UNUSED)
		return;

	if (clk_core_is_prepared(core)) {
		trace_clk_unprepare(core);
		if (core->ops->unprepare_unused)
			core->ops->unprepare_unused(core->hw);
		else if (core->ops->unprepare)
			core->ops->unprepare(core->hw);
		trace_clk_unprepare_complete(core);
	}
}

static void clk_disable_unused_subtree(struct clk_core *core)
{
	struct clk_core *child;
	unsigned long flags;

	lockdep_assert_held(&prepare_lock);

	hlist_for_each_entry(child, &core->children, child_node)
		clk_disable_unused_subtree(child);

	flags = clk_enable_lock();

	if (core->enable_count)
		goto unlock_out;

	if (core->flags & CLK_IGNORE_UNUSED)
		goto unlock_out;

	/*
	 * some gate clocks have special needs during the disable-unused
	 * sequence.  call .disable_unused if available, otherwise fall
	 * back to .disable
	 */
	if (clk_core_is_enabled(core)) {
		trace_clk_disable(core);
		if (core->ops->disable_unused)
			core->ops->disable_unused(core->hw);
		else if (core->ops->disable)
			core->ops->disable(core->hw);
		trace_clk_disable_complete(core);
	}

unlock_out:
	clk_enable_unlock(flags);
}

static bool clk_ignore_unused;
static int __init clk_ignore_unused_setup(char *__unused)
{
	clk_ignore_unused = true;
	return 1;
}
__setup("clk_ignore_unused", clk_ignore_unused_setup);

static int clk_disable_unused(void)
{
	struct clk_core *core;

	if (clk_ignore_unused) {
		pr_warn("clk: Not disabling unused clocks\n");
		return 0;
	}

	clk_prepare_lock();

	hlist_for_each_entry(core, &clk_root_list, child_node)
		clk_disable_unused_subtree(core);

	hlist_for_each_entry(core, &clk_orphan_list, child_node)
		clk_disable_unused_subtree(core);

	hlist_for_each_entry(core, &clk_root_list, child_node)
		clk_unprepare_unused_subtree(core);

	hlist_for_each_entry(core, &clk_orphan_list, child_node)
		clk_unprepare_unused_subtree(core);

	clk_prepare_unlock();

	return 0;
}
late_initcall_sync(clk_disable_unused);

/***    helper functions   ***/

const char *__clk_get_name(struct clk *clk)
{
	return !clk ? NULL : clk->core->name;
}
EXPORT_SYMBOL_GPL(__clk_get_name);

struct clk_hw *__clk_get_hw(struct clk *clk)
{
	return !clk ? NULL : clk->core->hw;
}
EXPORT_SYMBOL_GPL(__clk_get_hw);

u8 __clk_get_num_parents(struct clk *clk)
{
	return !clk ? 0 : clk->core->num_parents;
}
EXPORT_SYMBOL_GPL(__clk_get_num_parents);

struct clk *__clk_get_parent(struct clk *clk)
{
	if (!clk)
		return NULL;

	/* TODO: Create a per-user clk and change callers to call clk_put */
	return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
}
EXPORT_SYMBOL_GPL(__clk_get_parent);

static struct clk_core *__clk_lookup_subtree(const char *name,
					     struct clk_core *core)
{
	struct clk_core *child;
	struct clk_core *ret;

	if (!strcmp(core->name, name))
		return core;

	hlist_for_each_entry(child, &core->children, child_node) {
		ret = __clk_lookup_subtree(name, child);
		if (ret)
			return ret;
	}

	return NULL;
}

static struct clk_core *clk_core_lookup(const char *name)
{
	struct clk_core *root_clk;
	struct clk_core *ret;

	if (!name)
		return NULL;

	/* search the 'proper' clk tree first */
	hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
		ret = __clk_lookup_subtree(name, root_clk);
		if (ret)
			return ret;
	}

	/* if not found, then search the orphan tree */
	hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
		ret = __clk_lookup_subtree(name, root_clk);
		if (ret)
			return ret;
	}

	return NULL;
}

static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
							 u8 index)
{
	if (!core || index >= core->num_parents)
		return NULL;
	else if (!core->parents)
		return clk_core_lookup(core->parent_names[index]);
	else if (!core->parents[index])
		return core->parents[index] =
			clk_core_lookup(core->parent_names[index]);
	else
		return core->parents[index];
}

struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
{
	struct clk_core *parent;

	if (!clk)
		return NULL;

	parent = clk_core_get_parent_by_index(clk->core, index);

	return !parent ? NULL : parent->hw->clk;
}
EXPORT_SYMBOL_GPL(clk_get_parent_by_index);

unsigned int __clk_get_enable_count(struct clk *clk)
{
	return !clk ? 0 : clk->core->enable_count;
}

static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
{
	unsigned long ret;

	if (!core) {
		ret = 0;
		goto out;
	}

	ret = core->rate;

	if (core->flags & CLK_IS_ROOT)
		goto out;

	if (!core->parent)
		ret = 0;

out:
	return ret;
}

unsigned long __clk_get_rate(struct clk *clk)
{
	if (!clk)
		return 0;

	return clk_core_get_rate_nolock(clk->core);
}
EXPORT_SYMBOL_GPL(__clk_get_rate);

static unsigned long __clk_get_accuracy(struct clk_core *core)
{
	if (!core)
		return 0;

	return core->accuracy;
}

unsigned long __clk_get_flags(struct clk *clk)
{
	return !clk ? 0 : clk->core->flags;
}
EXPORT_SYMBOL_GPL(__clk_get_flags);

bool __clk_is_prepared(struct clk *clk)
{
	if (!clk)
		return false;

	return clk_core_is_prepared(clk->core);
}

bool __clk_is_enabled(struct clk *clk)
{
	if (!clk)
		return false;

	return clk_core_is_enabled(clk->core);
}
EXPORT_SYMBOL_GPL(__clk_is_enabled);

static bool mux_is_better_rate(unsigned long rate, unsigned long now,
			   unsigned long best, unsigned long flags)
{
	if (flags & CLK_MUX_ROUND_CLOSEST)
		return abs(now - rate) < abs(best - rate);

	return now <= rate && now > best;
}

static long
clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
			     unsigned long min_rate,
			     unsigned long max_rate,
			     unsigned long *best_parent_rate,
			     struct clk_hw **best_parent_p,
			     unsigned long flags)
{
	struct clk_core *core = hw->core, *parent, *best_parent = NULL;
	int i, num_parents;
	unsigned long parent_rate, best = 0;

	/* if NO_REPARENT flag set, pass through to current parent */
	if (core->flags & CLK_SET_RATE_NO_REPARENT) {
		parent = core->parent;
		if (core->flags & CLK_SET_RATE_PARENT)
			best = __clk_determine_rate(parent ? parent->hw : NULL,
						    rate, min_rate, max_rate);
		else if (parent)
			best = clk_core_get_rate_nolock(parent);
		else
			best = clk_core_get_rate_nolock(core);
		goto out;
	}

	/* find the parent that can provide the fastest rate <= rate */
	num_parents = core->num_parents;
	for (i = 0; i < num_parents; i++) {
		parent = clk_core_get_parent_by_index(core, i);
		if (!parent)
			continue;
		if (core->flags & CLK_SET_RATE_PARENT)
			parent_rate = __clk_determine_rate(parent->hw, rate,
							   min_rate,
							   max_rate);
		else
			parent_rate = clk_core_get_rate_nolock(parent);
		if (mux_is_better_rate(rate, parent_rate, best, flags)) {
			best_parent = parent;
			best = parent_rate;
		}
	}

out:
	if (best_parent)
		*best_parent_p = best_parent->hw;
	*best_parent_rate = best;

	return best;
}

struct clk *__clk_lookup(const char *name)
{
	struct clk_core *core = clk_core_lookup(name);

	return !core ? NULL : core->hw->clk;
}

static void clk_core_get_boundaries(struct clk_core *core,
				    unsigned long *min_rate,
				    unsigned long *max_rate)
{
	struct clk *clk_user;

	*min_rate = 0;
	*max_rate = ULONG_MAX;

	hlist_for_each_entry(clk_user, &core->clks, clks_node)
		*min_rate = max(*min_rate, clk_user->min_rate);

	hlist_for_each_entry(clk_user, &core->clks, clks_node)
		*max_rate = min(*max_rate, clk_user->max_rate);
}

/*
 * Helper for finding best parent to provide a given frequency. This can be used
 * directly as a determine_rate callback (e.g. for a mux), or from a more
 * complex clock that may combine a mux with other operations.
 */
long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
			      unsigned long min_rate,
			      unsigned long max_rate,
			      unsigned long *best_parent_rate,
			      struct clk_hw **best_parent_p)
{
	return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
					    best_parent_rate,
					    best_parent_p, 0);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);

long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
			      unsigned long min_rate,
			      unsigned long max_rate,
			      unsigned long *best_parent_rate,
			      struct clk_hw **best_parent_p)
{
	return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
					    best_parent_rate,
					    best_parent_p,
					    CLK_MUX_ROUND_CLOSEST);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);

/***        clk api        ***/

static void clk_core_unprepare(struct clk_core *core)
{
	lockdep_assert_held(&prepare_lock);

	if (!core)
		return;

	if (WARN_ON(core->prepare_count == 0))
		return;

	if (--core->prepare_count > 0)
		return;

	WARN_ON(core->enable_count > 0);

	trace_clk_unprepare(core);

	if (core->ops->unprepare)
		core->ops->unprepare(core->hw);

	trace_clk_unprepare_complete(core);
	clk_core_unprepare(core->parent);
}

/**
 * clk_unprepare - undo preparation of a clock source
 * @clk: the clk being unprepared
 *
 * clk_unprepare may sleep, which differentiates it from clk_disable.  In a
 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
 * if the operation may sleep.  One example is a clk which is accessed over
 * I2c.  In the complex case a clk gate operation may require a fast and a slow
 * part.  It is this reason that clk_unprepare and clk_disable are not mutually
 * exclusive.  In fact clk_disable must be called before clk_unprepare.
 */
void clk_unprepare(struct clk *clk)
{
	if (IS_ERR_OR_NULL(clk))
		return;

	clk_prepare_lock();
	clk_core_unprepare(clk->core);
	clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unprepare);

static int clk_core_prepare(struct clk_core *core)
{
	int ret = 0;

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	if (core->prepare_count == 0) {
		ret = clk_core_prepare(core->parent);
		if (ret)
			return ret;

		trace_clk_prepare(core);

		if (core->ops->prepare)
			ret = core->ops->prepare(core->hw);

		trace_clk_prepare_complete(core);

		if (ret) {
			clk_core_unprepare(core->parent);
			return ret;
		}
	}

	core->prepare_count++;

	return 0;
}

/**
 * clk_prepare - prepare a clock source
 * @clk: the clk being prepared
 *
 * clk_prepare may sleep, which differentiates it from clk_enable.  In a simple
 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
 * operation may sleep.  One example is a clk which is accessed over I2c.  In
 * the complex case a clk ungate operation may require a fast and a slow part.
 * It is this reason that clk_prepare and clk_enable are not mutually
 * exclusive.  In fact clk_prepare must be called before clk_enable.
 * Returns 0 on success, -EERROR otherwise.
 */
int clk_prepare(struct clk *clk)
{
	int ret;

	if (!clk)
		return 0;

	clk_prepare_lock();
	ret = clk_core_prepare(clk->core);
	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_prepare);

static void clk_core_disable(struct clk_core *core)
{
	lockdep_assert_held(&enable_lock);

	if (!core)
		return;

	if (WARN_ON(core->enable_count == 0))
		return;

	if (--core->enable_count > 0)
		return;

	trace_clk_disable(core);

	if (core->ops->disable)
		core->ops->disable(core->hw);

	trace_clk_disable_complete(core);

	clk_core_disable(core->parent);
}

/**
 * clk_disable - gate a clock
 * @clk: the clk being gated
 *
 * clk_disable must not sleep, which differentiates it from clk_unprepare.  In
 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
 * clk if the operation is fast and will never sleep.  One example is a
 * SoC-internal clk which is controlled via simple register writes.  In the
 * complex case a clk gate operation may require a fast and a slow part.  It is
 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
 * In fact clk_disable must be called before clk_unprepare.
 */
void clk_disable(struct clk *clk)
{
	unsigned long flags;

	if (IS_ERR_OR_NULL(clk))
		return;

	flags = clk_enable_lock();
	clk_core_disable(clk->core);
	clk_enable_unlock(flags);
}
EXPORT_SYMBOL_GPL(clk_disable);

static int clk_core_enable(struct clk_core *core)
{
	int ret = 0;

	lockdep_assert_held(&enable_lock);

	if (!core)
		return 0;

	if (WARN_ON(core->prepare_count == 0))
		return -ESHUTDOWN;

	if (core->enable_count == 0) {
		ret = clk_core_enable(core->parent);

		if (ret)
			return ret;

		trace_clk_enable(core);

		if (core->ops->enable)
			ret = core->ops->enable(core->hw);

		trace_clk_enable_complete(core);

		if (ret) {
			clk_core_disable(core->parent);
			return ret;
		}
	}

	core->enable_count++;
	return 0;
}

/**
 * clk_enable - ungate a clock
 * @clk: the clk being ungated
 *
 * clk_enable must not sleep, which differentiates it from clk_prepare.  In a
 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
 * if the operation will never sleep.  One example is a SoC-internal clk which
 * is controlled via simple register writes.  In the complex case a clk ungate
 * operation may require a fast and a slow part.  It is this reason that
 * clk_enable and clk_prepare are not mutually exclusive.  In fact clk_prepare
 * must be called before clk_enable.  Returns 0 on success, -EERROR
 * otherwise.
 */
int clk_enable(struct clk *clk)
{
	unsigned long flags;
	int ret;

	if (!clk)
		return 0;

	flags = clk_enable_lock();
	ret = clk_core_enable(clk->core);
	clk_enable_unlock(flags);

	return ret;
}
EXPORT_SYMBOL_GPL(clk_enable);

static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
						unsigned long rate,
						unsigned long min_rate,
						unsigned long max_rate)
{
	unsigned long parent_rate = 0;
	struct clk_core *parent;
	struct clk_hw *parent_hw;

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	parent = core->parent;
	if (parent)
		parent_rate = parent->rate;

	if (core->ops->determine_rate) {
		parent_hw = parent ? parent->hw : NULL;
		return core->ops->determine_rate(core->hw, rate,
						min_rate, max_rate,
						&parent_rate, &parent_hw);
	} else if (core->ops->round_rate)
		return core->ops->round_rate(core->hw, rate, &parent_rate);
	else if (core->flags & CLK_SET_RATE_PARENT)
		return clk_core_round_rate_nolock(core->parent, rate, min_rate,
						  max_rate);
	else
		return core->rate;
}

/**
 * __clk_determine_rate - get the closest rate actually supported by a clock
 * @hw: determine the rate of this clock
 * @rate: target rate
 * @min_rate: returned rate must be greater than this rate
 * @max_rate: returned rate must be less than this rate
 *
 * Useful for clk_ops such as .set_rate and .determine_rate.
 */
unsigned long __clk_determine_rate(struct clk_hw *hw,
				   unsigned long rate,
				   unsigned long min_rate,
				   unsigned long max_rate)
{
	if (!hw)
		return 0;

	return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
}
EXPORT_SYMBOL_GPL(__clk_determine_rate);

/**
 * __clk_round_rate - round the given rate for a clk
 * @clk: round the rate of this clock
 * @rate: the rate which is to be rounded
 *
 * Useful for clk_ops such as .set_rate
 */
unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
{
	unsigned long min_rate;
	unsigned long max_rate;

	if (!clk)
		return 0;

	clk_core_get_boundaries(clk->core, &min_rate, &max_rate);

	return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
}
EXPORT_SYMBOL_GPL(__clk_round_rate);

/**
 * clk_round_rate - round the given rate for a clk
 * @clk: the clk for which we are rounding a rate
 * @rate: the rate which is to be rounded
 *
 * Takes in a rate as input and rounds it to a rate that the clk can actually
 * use which is then returned.  If clk doesn't support round_rate operation
 * then the parent rate is returned.
 */
long clk_round_rate(struct clk *clk, unsigned long rate)
{
	unsigned long ret;

	if (!clk)
		return 0;

	clk_prepare_lock();
	ret = __clk_round_rate(clk, rate);
	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_round_rate);

/**
 * __clk_notify - call clk notifier chain
 * @core: clk that is changing rate
 * @msg: clk notifier type (see include/linux/clk.h)
 * @old_rate: old clk rate
 * @new_rate: new clk rate
 *
 * Triggers a notifier call chain on the clk rate-change notification
 * for 'clk'.  Passes a pointer to the struct clk and the previous
 * and current rates to the notifier callback.  Intended to be called by
 * internal clock code only.  Returns NOTIFY_DONE from the last driver
 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
 * a driver returns that.
 */
static int __clk_notify(struct clk_core *core, unsigned long msg,
		unsigned long old_rate, unsigned long new_rate)
{
	struct clk_notifier *cn;
	struct clk_notifier_data cnd;
	int ret = NOTIFY_DONE;

	cnd.old_rate = old_rate;
	cnd.new_rate = new_rate;

	list_for_each_entry(cn, &clk_notifier_list, node) {
		if (cn->clk->core == core) {
			cnd.clk = cn->clk;
			ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
					&cnd);
		}
	}

	return ret;
}

/**
 * __clk_recalc_accuracies
 * @core: first clk in the subtree
 *
 * Walks the subtree of clks starting with clk and recalculates accuracies as
 * it goes.  Note that if a clk does not implement the .recalc_accuracy
 * callback then it is assumed that the clock will take on the accuracy of its
 * parent.
 */
static void __clk_recalc_accuracies(struct clk_core *core)
{
	unsigned long parent_accuracy = 0;
	struct clk_core *child;

	lockdep_assert_held(&prepare_lock);

	if (core->parent)
		parent_accuracy = core->parent->accuracy;

	if (core->ops->recalc_accuracy)
		core->accuracy = core->ops->recalc_accuracy(core->hw,
							  parent_accuracy);
	else
		core->accuracy = parent_accuracy;

	hlist_for_each_entry(child, &core->children, child_node)
		__clk_recalc_accuracies(child);
}

static long clk_core_get_accuracy(struct clk_core *core)
{
	unsigned long accuracy;

	clk_prepare_lock();
	if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
		__clk_recalc_accuracies(core);

	accuracy = __clk_get_accuracy(core);
	clk_prepare_unlock();

	return accuracy;
}

/**
 * clk_get_accuracy - return the accuracy of clk
 * @clk: the clk whose accuracy is being returned
 *
 * Simply returns the cached accuracy of the clk, unless
 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
 * issued.
 * If clk is NULL then returns 0.
 */
long clk_get_accuracy(struct clk *clk)
{
	if (!clk)
		return 0;

	return clk_core_get_accuracy(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_accuracy);

static unsigned long clk_recalc(struct clk_core *core,
				unsigned long parent_rate)
{
	if (core->ops->recalc_rate)
		return core->ops->recalc_rate(core->hw, parent_rate);
	return parent_rate;
}

/**
 * __clk_recalc_rates
 * @core: first clk in the subtree
 * @msg: notification type (see include/linux/clk.h)
 *
 * Walks the subtree of clks starting with clk and recalculates rates as it
 * goes.  Note that if a clk does not implement the .recalc_rate callback then
 * it is assumed that the clock will take on the rate of its parent.
 *
 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
 * if necessary.
 */
static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
{
	unsigned long old_rate;
	unsigned long parent_rate = 0;
	struct clk_core *child;

	lockdep_assert_held(&prepare_lock);

	old_rate = core->rate;

	if (core->parent)
		parent_rate = core->parent->rate;

	core->rate = clk_recalc(core, parent_rate);

	/*
	 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
	 * & ABORT_RATE_CHANGE notifiers
	 */
	if (core->notifier_count && msg)
		__clk_notify(core, msg, old_rate, core->rate);

	hlist_for_each_entry(child, &core->children, child_node)
		__clk_recalc_rates(child, msg);
}

static unsigned long clk_core_get_rate(struct clk_core *core)
{
	unsigned long rate;

	clk_prepare_lock();

	if (core && (core->flags & CLK_GET_RATE_NOCACHE))
		__clk_recalc_rates(core, 0);

	rate = clk_core_get_rate_nolock(core);
	clk_prepare_unlock();

	return rate;
}

/**
 * clk_get_rate - return the rate of clk
 * @clk: the clk whose rate is being returned
 *
 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
 * is set, which means a recalc_rate will be issued.
 * If clk is NULL then returns 0.
 */
unsigned long clk_get_rate(struct clk *clk)
{
	if (!clk)
		return 0;

	return clk_core_get_rate(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_rate);

static int clk_fetch_parent_index(struct clk_core *core,
				  struct clk_core *parent)
{
	int i;

	if (!core->parents) {
		core->parents = kcalloc(core->num_parents,
					sizeof(struct clk *), GFP_KERNEL);
		if (!core->parents)
			return -ENOMEM;
	}

	/*
	 * find index of new parent clock using cached parent ptrs,
	 * or if not yet cached, use string name comparison and cache
	 * them now to avoid future calls to clk_core_lookup.
	 */
	for (i = 0; i < core->num_parents; i++) {
		if (core->parents[i] == parent)
			return i;

		if (core->parents[i])
			continue;

		if (!strcmp(core->parent_names[i], parent->name)) {
			core->parents[i] = clk_core_lookup(parent->name);
			return i;
		}
	}

	return -EINVAL;
}

static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
	hlist_del(&core->child_node);

	if (new_parent) {
		/* avoid duplicate POST_RATE_CHANGE notifications */
		if (new_parent->new_child == core)
			new_parent->new_child = NULL;

		hlist_add_head(&core->child_node, &new_parent->children);
	} else {
		hlist_add_head(&core->child_node, &clk_orphan_list);
	}

	core->parent = new_parent;
}

static struct clk_core *__clk_set_parent_before(struct clk_core *core,
					   struct clk_core *parent)
{
	unsigned long flags;
	struct clk_core *old_parent = core->parent;

	/*
	 * Migrate prepare state between parents and prevent race with
	 * clk_enable().
	 *
	 * If the clock is not prepared, then a race with
	 * clk_enable/disable() is impossible since we already have the
	 * prepare lock (future calls to clk_enable() need to be preceded by
	 * a clk_prepare()).
	 *
	 * If the clock is prepared, migrate the prepared state to the new
	 * parent and also protect against a race with clk_enable() by
	 * forcing the clock and the new parent on.  This ensures that all
	 * future calls to clk_enable() are practically NOPs with respect to
	 * hardware and software states.
	 *
	 * See also: Comment for clk_set_parent() below.
	 */
	if (core->prepare_count) {
		clk_core_prepare(parent);
		flags = clk_enable_lock();
		clk_core_enable(parent);
		clk_core_enable(core);
		clk_enable_unlock(flags);
	}

	/* update the clk tree topology */
	flags = clk_enable_lock();
	clk_reparent(core, parent);
	clk_enable_unlock(flags);

	return old_parent;
}

static void __clk_set_parent_after(struct clk_core *core,
				   struct clk_core *parent,
				   struct clk_core *old_parent)
{
	unsigned long flags;

	/*
	 * Finish the migration of prepare state and undo the changes done
	 * for preventing a race with clk_enable().
	 */
	if (core->prepare_count) {
		flags = clk_enable_lock();
		clk_core_disable(core);
		clk_core_disable(old_parent);
		clk_enable_unlock(flags);
		clk_core_unprepare(old_parent);
	}
}

static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
			    u8 p_index)
{
	unsigned long flags;
	int ret = 0;
	struct clk_core *old_parent;

	old_parent = __clk_set_parent_before(core, parent);

	trace_clk_set_parent(core, parent);

	/* change clock input source */
	if (parent && core->ops->set_parent)
		ret = core->ops->set_parent(core->hw, p_index);

	trace_clk_set_parent_complete(core, parent);

	if (ret) {
		flags = clk_enable_lock();
		clk_reparent(core, old_parent);
		clk_enable_unlock(flags);

		if (core->prepare_count) {
			flags = clk_enable_lock();
			clk_core_disable(core);
			clk_core_disable(parent);
			clk_enable_unlock(flags);
			clk_core_unprepare(parent);
		}
		return ret;
	}

	__clk_set_parent_after(core, parent, old_parent);

	return 0;
}

/**
 * __clk_speculate_rates
 * @core: first clk in the subtree
 * @parent_rate: the "future" rate of clk's parent
 *
 * Walks the subtree of clks starting with clk, speculating rates as it
 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
 *
 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
 * pre-rate change notifications and returns early if no clks in the
 * subtree have subscribed to the notifications.  Note that if a clk does not
 * implement the .recalc_rate callback then it is assumed that the clock will
 * take on the rate of its parent.
 */
static int __clk_speculate_rates(struct clk_core *core,
				 unsigned long parent_rate)
{
	struct clk_core *child;
	unsigned long new_rate;
	int ret = NOTIFY_DONE;

	lockdep_assert_held(&prepare_lock);

	new_rate = clk_recalc(core, parent_rate);

	/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
	if (core->notifier_count)
		ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);

	if (ret & NOTIFY_STOP_MASK) {
		pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
				__func__, core->name, ret);
		goto out;
	}

	hlist_for_each_entry(child, &core->children, child_node) {
		ret = __clk_speculate_rates(child, new_rate);
		if (ret & NOTIFY_STOP_MASK)
			break;
	}

out:
	return ret;
}

static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
			     struct clk_core *new_parent, u8 p_index)
{
	struct clk_core *child;

	core->new_rate = new_rate;
	core->new_parent = new_parent;
	core->new_parent_index = p_index;
	/* include clk in new parent's PRE_RATE_CHANGE notifications */
	core->new_child = NULL;
	if (new_parent && new_parent != core->parent)
		new_parent->new_child = core;

	hlist_for_each_entry(child, &core->children, child_node) {
		child->new_rate = clk_recalc(child, new_rate);
		clk_calc_subtree(child, child->new_rate, NULL, 0);
	}
}

/*
 * calculate the new rates returning the topmost clock that has to be
 * changed.
 */
static struct clk_core *clk_calc_new_rates(struct clk_core *core,
					   unsigned long rate)
{
	struct clk_core *top = core;
	struct clk_core *old_parent, *parent;
	struct clk_hw *parent_hw;
	unsigned long best_parent_rate = 0;
	unsigned long new_rate;
	unsigned long min_rate;
	unsigned long max_rate;
	int p_index = 0;
	long ret;

	/* sanity */
	if (IS_ERR_OR_NULL(core))
		return NULL;

	/* save parent rate, if it exists */
	parent = old_parent = core->parent;
	if (parent)
		best_parent_rate = parent->rate;

	clk_core_get_boundaries(core, &min_rate, &max_rate);

	/* find the closest rate and parent clk/rate */
	if (core->ops->determine_rate) {
		parent_hw = parent ? parent->hw : NULL;
		ret = core->ops->determine_rate(core->hw, rate,
					       min_rate,
					       max_rate,
					       &best_parent_rate,
					       &parent_hw);
		if (ret < 0)
			return NULL;

		new_rate = ret;
		parent = parent_hw ? parent_hw->core : NULL;
	} else if (core->ops->round_rate) {
		ret = core->ops->round_rate(core->hw, rate,
					   &best_parent_rate);
		if (ret < 0)
			return NULL;

		new_rate = ret;
		if (new_rate < min_rate || new_rate > max_rate)
			return NULL;
	} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
		/* pass-through clock without adjustable parent */
		core->new_rate = core->rate;
		return NULL;
	} else {
		/* pass-through clock with adjustable parent */
		top = clk_calc_new_rates(parent, rate);
		new_rate = parent->new_rate;
		goto out;
	}

	/* some clocks must be gated to change parent */
	if (parent != old_parent &&
	    (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
		pr_debug("%s: %s not gated but wants to reparent\n",
			 __func__, core->name);
		return NULL;
	}

	/* try finding the new parent index */
	if (parent && core->num_parents > 1) {
		p_index = clk_fetch_parent_index(core, parent);
		if (p_index < 0) {
			pr_debug("%s: clk %s can not be parent of clk %s\n",
				 __func__, parent->name, core->name);
			return NULL;
		}
	}

	if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
	    best_parent_rate != parent->rate)
		top = clk_calc_new_rates(parent, best_parent_rate);

out:
	clk_calc_subtree(core, new_rate, parent, p_index);

	return top;
}

/*
 * Notify about rate changes in a subtree. Always walk down the whole tree
 * so that in case of an error we can walk down the whole tree again and
 * abort the change.
 */
static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
						  unsigned long event)
{
	struct clk_core *child, *tmp_clk, *fail_clk = NULL;
	int ret = NOTIFY_DONE;

	if (core->rate == core->new_rate)
		return NULL;

	if (core->notifier_count) {
		ret = __clk_notify(core, event, core->rate, core->new_rate);
		if (ret & NOTIFY_STOP_MASK)
			fail_clk = core;
	}

	hlist_for_each_entry(child, &core->children, child_node) {
		/* Skip children who will be reparented to another clock */
		if (child->new_parent && child->new_parent != core)
			continue;
		tmp_clk = clk_propagate_rate_change(child, event);
		if (tmp_clk)
			fail_clk = tmp_clk;
	}

	/* handle the new child who might not be in core->children yet */
	if (core->new_child) {
		tmp_clk = clk_propagate_rate_change(core->new_child, event);
		if (tmp_clk)
			fail_clk = tmp_clk;
	}

	return fail_clk;
}

/*
 * walk down a subtree and set the new rates notifying the rate
 * change on the way
 */
static void clk_change_rate(struct clk_core *core)
{
	struct clk_core *child;
	struct hlist_node *tmp;
	unsigned long old_rate;
	unsigned long best_parent_rate = 0;
	bool skip_set_rate = false;
	struct clk_core *old_parent;

	old_rate = core->rate;

	if (core->new_parent)
		best_parent_rate = core->new_parent->rate;
	else if (core->parent)
		best_parent_rate = core->parent->rate;

	if (core->new_parent && core->new_parent != core->parent) {
		old_parent = __clk_set_parent_before(core, core->new_parent);
		trace_clk_set_parent(core, core->new_parent);

		if (core->ops->set_rate_and_parent) {
			skip_set_rate = true;
			core->ops->set_rate_and_parent(core->hw, core->new_rate,
					best_parent_rate,
					core->new_parent_index);
		} else if (core->ops->set_parent) {
			core->ops->set_parent(core->hw, core->new_parent_index);
		}

		trace_clk_set_parent_complete(core, core->new_parent);
		__clk_set_parent_after(core, core->new_parent, old_parent);
	}

	trace_clk_set_rate(core, core->new_rate);

	if (!skip_set_rate && core->ops->set_rate)
		core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);

	trace_clk_set_rate_complete(core, core->new_rate);

	core->rate = clk_recalc(core, best_parent_rate);

	if (core->notifier_count && old_rate != core->rate)
		__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);

	if (core->flags & CLK_RECALC_NEW_RATES)
		(void)clk_calc_new_rates(core, core->new_rate);

	/*
	 * Use safe iteration, as change_rate can actually swap parents
	 * for certain clock types.
	 */
	hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
		/* Skip children who will be reparented to another clock */
		if (child->new_parent && child->new_parent != core)
			continue;
		clk_change_rate(child);
	}

	/* handle the new child who might not be in core->children yet */
	if (core->new_child)
		clk_change_rate(core->new_child);
}

static int clk_core_set_rate_nolock(struct clk_core *core,
				    unsigned long req_rate)
{
	struct clk_core *top, *fail_clk;
	unsigned long rate = req_rate;
	int ret = 0;

	if (!core)
		return 0;

	/* bail early if nothing to do */
	if (rate == clk_core_get_rate_nolock(core))
		return 0;

	if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
		return -EBUSY;

	/* calculate new rates and get the topmost changed clock */
	top = clk_calc_new_rates(core, rate);
	if (!top)
		return -EINVAL;

	/* notify that we are about to change rates */
	fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
	if (fail_clk) {
		pr_debug("%s: failed to set %s rate\n", __func__,
				fail_clk->name);
		clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
		return -EBUSY;
	}

	/* change the rates */
	clk_change_rate(top);

	core->req_rate = req_rate;

	return ret;
}

/**
 * clk_set_rate - specify a new rate for clk
 * @clk: the clk whose rate is being changed
 * @rate: the new rate for clk
 *
 * In the simplest case clk_set_rate will only adjust the rate of clk.
 *
 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
 * propagate up to clk's parent; whether or not this happens depends on the
 * outcome of clk's .round_rate implementation.  If *parent_rate is unchanged
 * after calling .round_rate then upstream parent propagation is ignored.  If
 * *parent_rate comes back with a new rate for clk's parent then we propagate
 * up to clk's parent and set its rate.  Upward propagation will continue
 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
 * .round_rate stops requesting changes to clk's parent_rate.
 *
 * Rate changes are accomplished via tree traversal that also recalculates the
 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
 *
 * Returns 0 on success, -EERROR otherwise.
 */
int clk_set_rate(struct clk *clk, unsigned long rate)
{
	int ret;

	if (!clk)
		return 0;

	/* prevent racing with updates to the clock topology */
	clk_prepare_lock();

	ret = clk_core_set_rate_nolock(clk->core, rate);

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate);

/**
 * clk_set_rate_range - set a rate range for a clock source
 * @clk: clock source
 * @min: desired minimum clock rate in Hz, inclusive
 * @max: desired maximum clock rate in Hz, inclusive
 *
 * Returns success (0) or negative errno.
 */
int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
{
	int ret = 0;

	if (!clk)
		return 0;

	if (min > max) {
		pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
		       __func__, clk->core->name, clk->dev_id, clk->con_id,
		       min, max);
		return -EINVAL;
	}

	clk_prepare_lock();

	if (min != clk->min_rate || max != clk->max_rate) {
		clk->min_rate = min;
		clk->max_rate = max;
		ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
	}

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_range);

/**
 * clk_set_min_rate - set a minimum clock rate for a clock source
 * @clk: clock source
 * @rate: desired minimum clock rate in Hz, inclusive
 *
 * Returns success (0) or negative errno.
 */
int clk_set_min_rate(struct clk *clk, unsigned long rate)
{
	if (!clk)
		return 0;

	return clk_set_rate_range(clk, rate, clk->max_rate);
}
EXPORT_SYMBOL_GPL(clk_set_min_rate);

/**
 * clk_set_max_rate - set a maximum clock rate for a clock source
 * @clk: clock source
 * @rate: desired maximum clock rate in Hz, inclusive
 *
 * Returns success (0) or negative errno.
 */
int clk_set_max_rate(struct clk *clk, unsigned long rate)
{
	if (!clk)
		return 0;

	return clk_set_rate_range(clk, clk->min_rate, rate);
}
EXPORT_SYMBOL_GPL(clk_set_max_rate);

/**
 * clk_get_parent - return the parent of a clk
 * @clk: the clk whose parent gets returned
 *
 * Simply returns clk->parent.  Returns NULL if clk is NULL.
 */
struct clk *clk_get_parent(struct clk *clk)
{
	struct clk *parent;

	clk_prepare_lock();
	parent = __clk_get_parent(clk);
	clk_prepare_unlock();

	return parent;
}
EXPORT_SYMBOL_GPL(clk_get_parent);

/*
 * .get_parent is mandatory for clocks with multiple possible parents.  It is
 * optional for single-parent clocks.  Always call .get_parent if it is
 * available and WARN if it is missing for multi-parent clocks.
 *
 * For single-parent clocks without .get_parent, first check to see if the
 * .parents array exists, and if so use it to avoid an expensive tree
 * traversal.  If .parents does not exist then walk the tree.
 */
static struct clk_core *__clk_init_parent(struct clk_core *core)
{
	struct clk_core *ret = NULL;
	u8 index;

	/* handle the trivial cases */

	if (!core->num_parents)
		goto out;

	if (core->num_parents == 1) {
		if (IS_ERR_OR_NULL(core->parent))
			core->parent = clk_core_lookup(core->parent_names[0]);
		ret = core->parent;
		goto out;
	}

	if (!core->ops->get_parent) {
		WARN(!core->ops->get_parent,
			"%s: multi-parent clocks must implement .get_parent\n",
			__func__);
		goto out;
	};

	/*
	 * Do our best to cache parent clocks in core->parents.  This prevents
	 * unnecessary and expensive lookups.  We don't set core->parent here;
	 * that is done by the calling function.
	 */

	index = core->ops->get_parent(core->hw);

	if (!core->parents)
		core->parents =
			kcalloc(core->num_parents, sizeof(struct clk *),
					GFP_KERNEL);

	ret = clk_core_get_parent_by_index(core, index);

out:
	return ret;
}

static void clk_core_reparent(struct clk_core *core,
				  struct clk_core *new_parent)
{
	clk_reparent(core, new_parent);
	__clk_recalc_accuracies(core);
	__clk_recalc_rates(core, POST_RATE_CHANGE);
}

void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
{
	if (!hw)
		return;

	clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
}

/**
 * clk_has_parent - check if a clock is a possible parent for another
 * @clk: clock source
 * @parent: parent clock source
 *
 * This function can be used in drivers that need to check that a clock can be
 * the parent of another without actually changing the parent.
 *
 * Returns true if @parent is a possible parent for @clk, false otherwise.
 */
bool clk_has_parent(struct clk *clk, struct clk *parent)
{
	struct clk_core *core, *parent_core;
	unsigned int i;

	/* NULL clocks should be nops, so return success if either is NULL. */
	if (!clk || !parent)
		return true;

	core = clk->core;
	parent_core = parent->core;

	/* Optimize for the case where the parent is already the parent. */
	if (core->parent == parent_core)
		return true;

	for (i = 0; i < core->num_parents; i++)
		if (strcmp(core->parent_names[i], parent_core->name) == 0)
			return true;

	return false;
}
EXPORT_SYMBOL_GPL(clk_has_parent);

static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
{
	int ret = 0;
	int p_index = 0;
	unsigned long p_rate = 0;

	if (!core)
		return 0;

	/* prevent racing with updates to the clock topology */
	clk_prepare_lock();

	if (core->parent == parent)
		goto out;

	/* verify ops for for multi-parent clks */
	if ((core->num_parents > 1) && (!core->ops->set_parent)) {
		ret = -ENOSYS;
		goto out;
	}

	/* check that we are allowed to re-parent if the clock is in use */
	if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
		ret = -EBUSY;
		goto out;
	}

	/* try finding the new parent index */
	if (parent) {
		p_index = clk_fetch_parent_index(core, parent);
		p_rate = parent->rate;
		if (p_index < 0) {
			pr_debug("%s: clk %s can not be parent of clk %s\n",
					__func__, parent->name, core->name);
			ret = p_index;
			goto out;
		}
	}

	/* propagate PRE_RATE_CHANGE notifications */
	ret = __clk_speculate_rates(core, p_rate);

	/* abort if a driver objects */
	if (ret & NOTIFY_STOP_MASK)
		goto out;

	/* do the re-parent */
	ret = __clk_set_parent(core, parent, p_index);

	/* propagate rate an accuracy recalculation accordingly */
	if (ret) {
		__clk_recalc_rates(core, ABORT_RATE_CHANGE);
	} else {
		__clk_recalc_rates(core, POST_RATE_CHANGE);
		__clk_recalc_accuracies(core);
	}

out:
	clk_prepare_unlock();

	return ret;
}

/**
 * clk_set_parent - switch the parent of a mux clk
 * @clk: the mux clk whose input we are switching
 * @parent: the new input to clk
 *
 * Re-parent clk to use parent as its new input source.  If clk is in
 * prepared state, the clk will get enabled for the duration of this call. If
 * that's not acceptable for a specific clk (Eg: the consumer can't handle
 * that, the reparenting is glitchy in hardware, etc), use the
 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
 *
 * After successfully changing clk's parent clk_set_parent will update the
 * clk topology, sysfs topology and propagate rate recalculation via
 * __clk_recalc_rates.
 *
 * Returns 0 on success, -EERROR otherwise.
 */
int clk_set_parent(struct clk *clk, struct clk *parent)
{
	if (!clk)
		return 0;

	return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
}
EXPORT_SYMBOL_GPL(clk_set_parent);

/**
 * clk_set_phase - adjust the phase shift of a clock signal
 * @clk: clock signal source
 * @degrees: number of degrees the signal is shifted
 *
 * Shifts the phase of a clock signal by the specified
 * degrees. Returns 0 on success, -EERROR otherwise.
 *
 * This function makes no distinction about the input or reference
 * signal that we adjust the clock signal phase against. For example
 * phase locked-loop clock signal generators we may shift phase with
 * respect to feedback clock signal input, but for other cases the
 * clock phase may be shifted with respect to some other, unspecified
 * signal.
 *
 * Additionally the concept of phase shift does not propagate through
 * the clock tree hierarchy, which sets it apart from clock rates and
 * clock accuracy. A parent clock phase attribute does not have an
 * impact on the phase attribute of a child clock.
 */
int clk_set_phase(struct clk *clk, int degrees)
{
	int ret = -EINVAL;

	if (!clk)
		return 0;

	/* sanity check degrees */
	degrees %= 360;
	if (degrees < 0)
		degrees += 360;

	clk_prepare_lock();

	trace_clk_set_phase(clk->core, degrees);

	if (clk->core->ops->set_phase)
		ret = clk->core->ops->set_phase(clk->core->hw, degrees);

	trace_clk_set_phase_complete(clk->core, degrees);

	if (!ret)
		clk->core->phase = degrees;

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_phase);

static int clk_core_get_phase(struct clk_core *core)
{
	int ret;

	clk_prepare_lock();
	ret = core->phase;
	clk_prepare_unlock();

	return ret;
}

/**
 * clk_get_phase - return the phase shift of a clock signal
 * @clk: clock signal source
 *
 * Returns the phase shift of a clock node in degrees, otherwise returns
 * -EERROR.
 */
int clk_get_phase(struct clk *clk)
{
	if (!clk)
		return 0;

	return clk_core_get_phase(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_phase);

/**
 * clk_is_match - check if two clk's point to the same hardware clock
 * @p: clk compared against q
 * @q: clk compared against p
 *
 * Returns true if the two struct clk pointers both point to the same hardware
 * clock node. Put differently, returns true if struct clk *p and struct clk *q
 * share the same struct clk_core object.
 *
 * Returns false otherwise. Note that two NULL clks are treated as matching.
 */
bool clk_is_match(const struct clk *p, const struct clk *q)
{
	/* trivial case: identical struct clk's or both NULL */
	if (p == q)
		return true;

	/* true if clk->core pointers match. Avoid derefing garbage */
	if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
		if (p->core == q->core)
			return true;

	return false;
}
EXPORT_SYMBOL_GPL(clk_is_match);

/***        debugfs support        ***/

#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>

static struct dentry *rootdir;
static int inited = 0;
static DEFINE_MUTEX(clk_debug_lock);
static HLIST_HEAD(clk_debug_list);

static struct hlist_head *all_lists[] = {
	&clk_root_list,
	&clk_orphan_list,
	NULL,
};

static struct hlist_head *orphan_list[] = {
	&clk_orphan_list,
	NULL,
};

static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
				 int level)
{
	if (!c)
		return;

	seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
		   level * 3 + 1, "",
		   30 - level * 3, c->name,
		   c->enable_count, c->prepare_count, clk_core_get_rate(c),
		   clk_core_get_accuracy(c), clk_core_get_phase(c));
}

static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
				     int level)
{
	struct clk_core *child;

	if (!c)
		return;

	clk_summary_show_one(s, c, level);

	hlist_for_each_entry(child, &c->children, child_node)
		clk_summary_show_subtree(s, child, level + 1);
}

static int clk_summary_show(struct seq_file *s, void *data)
{
	struct clk_core *c;
	struct hlist_head **lists = (struct hlist_head **)s->private;

	seq_puts(s, "   clock                         enable_cnt  prepare_cnt        rate   accuracy   phase\n");
	seq_puts(s, "----------------------------------------------------------------------------------------\n");

	clk_prepare_lock();

	for (; *lists; lists++)
		hlist_for_each_entry(c, *lists, child_node)
			clk_summary_show_subtree(s, c, 0);

	clk_prepare_unlock();

	return 0;
}


static int clk_summary_open(struct inode *inode, struct file *file)
{
	return single_open(file, clk_summary_show, inode->i_private);
}

static const struct file_operations clk_summary_fops = {
	.open		= clk_summary_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
{
	if (!c)
		return;

	/* This should be JSON format, i.e. elements separated with a comma */
	seq_printf(s, "\"%s\": { ", c->name);
	seq_printf(s, "\"enable_count\": %d,", c->enable_count);
	seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
	seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
	seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
	seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
}

static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
{
	struct clk_core *child;

	if (!c)
		return;

	clk_dump_one(s, c, level);

	hlist_for_each_entry(child, &c->children, child_node) {
		seq_printf(s, ",");
		clk_dump_subtree(s, child, level + 1);
	}

	seq_printf(s, "}");
}

static int clk_dump(struct seq_file *s, void *data)
{
	struct clk_core *c;
	bool first_node = true;
	struct hlist_head **lists = (struct hlist_head **)s->private;

	seq_printf(s, "{");

	clk_prepare_lock();

	for (; *lists; lists++) {
		hlist_for_each_entry(c, *lists, child_node) {
			if (!first_node)
				seq_puts(s, ",");
			first_node = false;
			clk_dump_subtree(s, c, 0);
		}
	}

	clk_prepare_unlock();

	seq_puts(s, "}\n");
	return 0;
}


static int clk_dump_open(struct inode *inode, struct file *file)
{
	return single_open(file, clk_dump, inode->i_private);
}

static const struct file_operations clk_dump_fops = {
	.open		= clk_dump_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
{
	struct dentry *d;
	int ret = -ENOMEM;

	if (!core || !pdentry) {
		ret = -EINVAL;
		goto out;
	}

	d = debugfs_create_dir(core->name, pdentry);
	if (!d)
		goto out;

	core->dentry = d;

	d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
			(u32 *)&core->rate);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
			(u32 *)&core->accuracy);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
			(u32 *)&core->phase);
	if (!d)
		goto err_out;

	d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
			(u32 *)&core->flags);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
			(u32 *)&core->prepare_count);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
			(u32 *)&core->enable_count);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
			(u32 *)&core->notifier_count);
	if (!d)
		goto err_out;

	if (core->ops->debug_init) {
		ret = core->ops->debug_init(core->hw, core->dentry);
		if (ret)
			goto err_out;
	}

	ret = 0;
	goto out;

err_out:
	debugfs_remove_recursive(core->dentry);
	core->dentry = NULL;
out:
	return ret;
}

/**
 * clk_debug_register - add a clk node to the debugfs clk directory
 * @core: the clk being added to the debugfs clk directory
 *
 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
 * initialized.  Otherwise it bails out early since the debugfs clk directory
 * will be created lazily by clk_debug_init as part of a late_initcall.
 */
static int clk_debug_register(struct clk_core *core)
{
	int ret = 0;

	mutex_lock(&clk_debug_lock);
	hlist_add_head(&core->debug_node, &clk_debug_list);

	if (!inited)
		goto unlock;

	ret = clk_debug_create_one(core, rootdir);
unlock:
	mutex_unlock(&clk_debug_lock);

	return ret;
}

 /**
 * clk_debug_unregister - remove a clk node from the debugfs clk directory
 * @core: the clk being removed from the debugfs clk directory
 *
 * Dynamically removes a clk and all its child nodes from the
 * debugfs clk directory if clk->dentry points to debugfs created by
 * clk_debug_register in __clk_init.
 */
static void clk_debug_unregister(struct clk_core *core)
{
	mutex_lock(&clk_debug_lock);
	hlist_del_init(&core->debug_node);
	debugfs_remove_recursive(core->dentry);
	core->dentry = NULL;
	mutex_unlock(&clk_debug_lock);
}

struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
				void *data, const struct file_operations *fops)
{
	struct dentry *d = NULL;

	if (hw->core->dentry)
		d = debugfs_create_file(name, mode, hw->core->dentry, data,
					fops);

	return d;
}
EXPORT_SYMBOL_GPL(clk_debugfs_add_file);

/**
 * clk_debug_init - lazily populate the debugfs clk directory
 *
 * clks are often initialized very early during boot before memory can be
 * dynamically allocated and well before debugfs is setup. This function
 * populates the debugfs clk directory once at boot-time when we know that
 * debugfs is setup. It should only be called once at boot-time, all other clks
 * added dynamically will be done so with clk_debug_register.
 */
static int __init clk_debug_init(void)
{
	struct clk_core *core;
	struct dentry *d;

	rootdir = debugfs_create_dir("clk", NULL);

	if (!rootdir)
		return -ENOMEM;

	d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
				&clk_summary_fops);
	if (!d)
		return -ENOMEM;

	d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
				&clk_dump_fops);
	if (!d)
		return -ENOMEM;

	d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
				&orphan_list, &clk_summary_fops);
	if (!d)
		return -ENOMEM;

	d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
				&orphan_list, &clk_dump_fops);
	if (!d)
		return -ENOMEM;

	mutex_lock(&clk_debug_lock);
	hlist_for_each_entry(core, &clk_debug_list, debug_node)
		clk_debug_create_one(core, rootdir);

	inited = 1;
	mutex_unlock(&clk_debug_lock);

	return 0;
}
late_initcall(clk_debug_init);
#else
static inline int clk_debug_register(struct clk_core *core) { return 0; }
static inline void clk_debug_reparent(struct clk_core *core,
				      struct clk_core *new_parent)
{
}
static inline void clk_debug_unregister(struct clk_core *core)
{
}
#endif

/**
 * __clk_init - initialize the data structures in a struct clk
 * @dev:	device initializing this clk, placeholder for now
 * @clk:	clk being initialized
 *
 * Initializes the lists in struct clk_core, queries the hardware for the
 * parent and rate and sets them both.
 */
static int __clk_init(struct device *dev, struct clk *clk_user)
{
	int i, ret = 0;
	struct clk_core *orphan;
	struct hlist_node *tmp2;
	struct clk_core *core;
	unsigned long rate;

	if (!clk_user)
		return -EINVAL;

	core = clk_user->core;

	clk_prepare_lock();

	/* check to see if a clock with this name is already registered */
	if (clk_core_lookup(core->name)) {
		pr_debug("%s: clk %s already initialized\n",
				__func__, core->name);
		ret = -EEXIST;
		goto out;
	}

	/* check that clk_ops are sane.  See Documentation/clk.txt */
	if (core->ops->set_rate &&
	    !((core->ops->round_rate || core->ops->determine_rate) &&
	      core->ops->recalc_rate)) {
		pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
				__func__, core->name);
		ret = -EINVAL;
		goto out;
	}

	if (core->ops->set_parent && !core->ops->get_parent) {
		pr_warning("%s: %s must implement .get_parent & .set_parent\n",
				__func__, core->name);
		ret = -EINVAL;
		goto out;
	}

	if (core->ops->set_rate_and_parent &&
			!(core->ops->set_parent && core->ops->set_rate)) {
		pr_warn("%s: %s must implement .set_parent & .set_rate\n",
				__func__, core->name);
		ret = -EINVAL;
		goto out;
	}

	/* throw a WARN if any entries in parent_names are NULL */
	for (i = 0; i < core->num_parents; i++)
		WARN(!core->parent_names[i],
				"%s: invalid NULL in %s's .parent_names\n",
				__func__, core->name);

	/*
	 * Allocate an array of struct clk *'s to avoid unnecessary string
	 * look-ups of clk's possible parents.  This can fail for clocks passed
	 * in to clk_init during early boot; thus any access to core->parents[]
	 * must always check for a NULL pointer and try to populate it if
	 * necessary.
	 *
	 * If core->parents is not NULL we skip this entire block.  This allows
	 * for clock drivers to statically initialize core->parents.
	 */
	if (core->num_parents > 1 && !core->parents) {
		core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
					GFP_KERNEL);
		/*
		 * clk_core_lookup returns NULL for parents that have not been
		 * clk_init'd; thus any access to clk->parents[] must check
		 * for a NULL pointer.  We can always perform lazy lookups for
		 * missing parents later on.
		 */
		if (core->parents)
			for (i = 0; i < core->num_parents; i++)
				core->parents[i] =
					clk_core_lookup(core->parent_names[i]);
	}

	core->parent = __clk_init_parent(core);

	/*
	 * Populate core->parent if parent has already been __clk_init'd.  If
	 * parent has not yet been __clk_init'd then place clk in the orphan
	 * list.  If clk has set the CLK_IS_ROOT flag then place it in the root
	 * clk list.
	 *
	 * Every time a new clk is clk_init'd then we walk the list of orphan
	 * clocks and re-parent any that are children of the clock currently
	 * being clk_init'd.
	 */
	if (core->parent)
		hlist_add_head(&core->child_node,
				&core->parent->children);
	else if (core->flags & CLK_IS_ROOT)
		hlist_add_head(&core->child_node, &clk_root_list);
	else
		hlist_add_head(&core->child_node, &clk_orphan_list);

	/*
	 * Set clk's accuracy.  The preferred method is to use
	 * .recalc_accuracy. For simple clocks and lazy developers the default
	 * fallback is to use the parent's accuracy.  If a clock doesn't have a
	 * parent (or is orphaned) then accuracy is set to zero (perfect
	 * clock).
	 */
	if (core->ops->recalc_accuracy)
		core->accuracy = core->ops->recalc_accuracy(core->hw,
					__clk_get_accuracy(core->parent));
	else if (core->parent)
		core->accuracy = core->parent->accuracy;
	else
		core->accuracy = 0;

	/*
	 * Set clk's phase.
	 * Since a phase is by definition relative to its parent, just
	 * query the current clock phase, or just assume it's in phase.
	 */
	if (core->ops->get_phase)
		core->phase = core->ops->get_phase(core->hw);
	else
		core->phase = 0;

	/*
	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
	 * simple clocks and lazy developers the default fallback is to use the
	 * parent's rate.  If a clock doesn't have a parent (or is orphaned)
	 * then rate is set to zero.
	 */
	if (core->ops->recalc_rate)
		rate = core->ops->recalc_rate(core->hw,
				clk_core_get_rate_nolock(core->parent));
	else if (core->parent)
		rate = core->parent->rate;
	else
		rate = 0;
	core->rate = core->req_rate = rate;

	/*
	 * walk the list of orphan clocks and reparent any that are children of
	 * this clock
	 */
	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
		if (orphan->num_parents && orphan->ops->get_parent) {
			i = orphan->ops->get_parent(orphan->hw);
			if (!strcmp(core->name, orphan->parent_names[i]))
				clk_core_reparent(orphan, core);
			continue;
		}

		for (i = 0; i < orphan->num_parents; i++)
			if (!strcmp(core->name, orphan->parent_names[i])) {
				clk_core_reparent(orphan, core);
				break;
			}
	 }

	/*
	 * optional platform-specific magic
	 *
	 * The .init callback is not used by any of the basic clock types, but
	 * exists for weird hardware that must perform initialization magic.
	 * Please consider other ways of solving initialization problems before
	 * using this callback, as its use is discouraged.
	 */
	if (core->ops->init)
		core->ops->init(core->hw);

	kref_init(&core->ref);
out:
	clk_prepare_unlock();

	if (!ret)
		clk_debug_register(core);

	return ret;
}

struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
			     const char *con_id)
{
	struct clk *clk;

	/* This is to allow this function to be chained to others */
	if (!hw || IS_ERR(hw))
		return (struct clk *) hw;

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

	clk->core = hw->core;
	clk->dev_id = dev_id;
	clk->con_id = con_id;
	clk->max_rate = ULONG_MAX;

	clk_prepare_lock();
	hlist_add_head(&clk->clks_node, &hw->core->clks);
	clk_prepare_unlock();

	return clk;
}

void __clk_free_clk(struct clk *clk)
{
	clk_prepare_lock();
	hlist_del(&clk->clks_node);
	clk_prepare_unlock();

	kfree(clk);
}

/**
 * clk_register - allocate a new clock, register it and return an opaque cookie
 * @dev: device that is registering this clock
 * @hw: link to hardware-specific clock data
 *
 * clk_register is the primary interface for populating the clock tree with new
 * clock nodes.  It returns a pointer to the newly allocated struct clk which
 * cannot be dereferenced by driver code but may be used in conjunction with the
 * rest of the clock API.  In the event of an error clk_register will return an
 * error code; drivers must test for an error code after calling clk_register.
 */
struct clk *clk_register(struct device *dev, struct clk_hw *hw)
{
	int i, ret;
	struct clk_core *core;

	core = kzalloc(sizeof(*core), GFP_KERNEL);
	if (!core) {
		ret = -ENOMEM;
		goto fail_out;
	}

	core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
	if (!core->name) {
		ret = -ENOMEM;
		goto fail_name;
	}
	core->ops = hw->init->ops;
	if (dev && dev->driver)
		core->owner = dev->driver->owner;
	core->hw = hw;
	core->flags = hw->init->flags;
	core->num_parents = hw->init->num_parents;
	hw->core = core;

	/* allocate local copy in case parent_names is __initdata */
	core->parent_names = kcalloc(core->num_parents, sizeof(char *),
					GFP_KERNEL);

	if (!core->parent_names) {
		ret = -ENOMEM;
		goto fail_parent_names;
	}


	/* copy each string name in case parent_names is __initdata */
	for (i = 0; i < core->num_parents; i++) {
		core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
						GFP_KERNEL);
		if (!core->parent_names[i]) {
			ret = -ENOMEM;
			goto fail_parent_names_copy;
		}
	}

	INIT_HLIST_HEAD(&core->clks);

	hw->clk = __clk_create_clk(hw, NULL, NULL);
	if (IS_ERR(hw->clk)) {
		ret = PTR_ERR(hw->clk);
		goto fail_parent_names_copy;
	}

	ret = __clk_init(dev, hw->clk);
	if (!ret)
		return hw->clk;

	__clk_free_clk(hw->clk);
	hw->clk = NULL;

fail_parent_names_copy:
	while (--i >= 0)
		kfree_const(core->parent_names[i]);
	kfree(core->parent_names);
fail_parent_names:
	kfree_const(core->name);
fail_name:
	kfree(core);
fail_out:
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(clk_register);

/* Free memory allocated for a clock. */
static void __clk_release(struct kref *ref)
{
	struct clk_core *core = container_of(ref, struct clk_core, ref);
	int i = core->num_parents;

	lockdep_assert_held(&prepare_lock);

	kfree(core->parents);
	while (--i >= 0)
		kfree_const(core->parent_names[i]);

	kfree(core->parent_names);
	kfree_const(core->name);
	kfree(core);
}

/*
 * Empty clk_ops for unregistered clocks. These are used temporarily
 * after clk_unregister() was called on a clock and until last clock
 * consumer calls clk_put() and the struct clk object is freed.
 */
static int clk_nodrv_prepare_enable(struct clk_hw *hw)
{
	return -ENXIO;
}

static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
{
	WARN_ON_ONCE(1);
}

static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
					unsigned long parent_rate)
{
	return -ENXIO;
}

static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
{
	return -ENXIO;
}

static const struct clk_ops clk_nodrv_ops = {
	.enable		= clk_nodrv_prepare_enable,
	.disable	= clk_nodrv_disable_unprepare,
	.prepare	= clk_nodrv_prepare_enable,
	.unprepare	= clk_nodrv_disable_unprepare,
	.set_rate	= clk_nodrv_set_rate,
	.set_parent	= clk_nodrv_set_parent,
};

/**
 * clk_unregister - unregister a currently registered clock
 * @clk: clock to unregister
 */
void clk_unregister(struct clk *clk)
{
	unsigned long flags;

	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
		return;

	clk_debug_unregister(clk->core);

	clk_prepare_lock();

	if (clk->core->ops == &clk_nodrv_ops) {
		pr_err("%s: unregistered clock: %s\n", __func__,
		       clk->core->name);
		return;
	}
	/*
	 * Assign empty clock ops for consumers that might still hold
	 * a reference to this clock.
	 */
	flags = clk_enable_lock();
	clk->core->ops = &clk_nodrv_ops;
	clk_enable_unlock(flags);

	if (!hlist_empty(&clk->core->children)) {
		struct clk_core *child;
		struct hlist_node *t;

		/* Reparent all children to the orphan list. */
		hlist_for_each_entry_safe(child, t, &clk->core->children,
					  child_node)
			clk_core_set_parent(child, NULL);
	}

	hlist_del_init(&clk->core->child_node);

	if (clk->core->prepare_count)
		pr_warn("%s: unregistering prepared clock: %s\n",
					__func__, clk->core->name);
	kref_put(&clk->core->ref, __clk_release);

	clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unregister);

static void devm_clk_release(struct device *dev, void *res)
{
	clk_unregister(*(struct clk **)res);
}

/**
 * devm_clk_register - resource managed clk_register()
 * @dev: device that is registering this clock
 * @hw: link to hardware-specific clock data
 *
 * Managed clk_register(). Clocks returned from this function are
 * automatically clk_unregister()ed on driver detach. See clk_register() for
 * more information.
 */
struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
{
	struct clk *clk;
	struct clk **clkp;

	clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
	if (!clkp)
		return ERR_PTR(-ENOMEM);

	clk = clk_register(dev, hw);
	if (!IS_ERR(clk)) {
		*clkp = clk;
		devres_add(dev, clkp);
	} else {
		devres_free(clkp);
	}

	return clk;
}
EXPORT_SYMBOL_GPL(devm_clk_register);

static int devm_clk_match(struct device *dev, void *res, void *data)
{
	struct clk *c = res;
	if (WARN_ON(!c))
		return 0;
	return c == data;
}

/**
 * devm_clk_unregister - resource managed clk_unregister()
 * @clk: clock to unregister
 *
 * Deallocate a clock allocated with devm_clk_register(). Normally
 * this function will not need to be called and the resource management
 * code will ensure that the resource is freed.
 */
void devm_clk_unregister(struct device *dev, struct clk *clk)
{
	WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
}
EXPORT_SYMBOL_GPL(devm_clk_unregister);

/*
 * clkdev helpers
 */
int __clk_get(struct clk *clk)
{
	struct clk_core *core = !clk ? NULL : clk->core;

	if (core) {
		if (!try_module_get(core->owner))
			return 0;

		kref_get(&core->ref);
	}
	return 1;
}

void __clk_put(struct clk *clk)
{
	struct module *owner;

	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
		return;

	clk_prepare_lock();

	hlist_del(&clk->clks_node);
	if (clk->min_rate > clk->core->req_rate ||
	    clk->max_rate < clk->core->req_rate)
		clk_core_set_rate_nolock(clk->core, clk->core->req_rate);

	owner = clk->core->owner;
	kref_put(&clk->core->ref, __clk_release);

	clk_prepare_unlock();

	module_put(owner);

	kfree(clk);
}

/***        clk rate change notifiers        ***/

/**
 * clk_notifier_register - add a clk rate change notifier
 * @clk: struct clk * to watch
 * @nb: struct notifier_block * with callback info
 *
 * Request notification when clk's rate changes.  This uses an SRCU
 * notifier because we want it to block and notifier unregistrations are
 * uncommon.  The callbacks associated with the notifier must not
 * re-enter into the clk framework by calling any top-level clk APIs;
 * this will cause a nested prepare_lock mutex.
 *
 * In all notification cases cases (pre, post and abort rate change) the
 * original clock rate is passed to the callback via struct
 * clk_notifier_data.old_rate and the new frequency is passed via struct
 * clk_notifier_data.new_rate.
 *
 * clk_notifier_register() must be called from non-atomic context.
 * Returns -EINVAL if called with null arguments, -ENOMEM upon
 * allocation failure; otherwise, passes along the return value of
 * srcu_notifier_chain_register().
 */
int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
{
	struct clk_notifier *cn;
	int ret = -ENOMEM;

	if (!clk || !nb)
		return -EINVAL;

	clk_prepare_lock();

	/* search the list of notifiers for this clk */
	list_for_each_entry(cn, &clk_notifier_list, node)
		if (cn->clk == clk)
			break;

	/* if clk wasn't in the notifier list, allocate new clk_notifier */
	if (cn->clk != clk) {
		cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
		if (!cn)
			goto out;

		cn->clk = clk;
		srcu_init_notifier_head(&cn->notifier_head);

		list_add(&cn->node, &clk_notifier_list);
	}

	ret = srcu_notifier_chain_register(&cn->notifier_head, nb);

	clk->core->notifier_count++;

out:
	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_notifier_register);

/**
 * clk_notifier_unregister - remove a clk rate change notifier
 * @clk: struct clk *
 * @nb: struct notifier_block * with callback info
 *
 * Request no further notification for changes to 'clk' and frees memory
 * allocated in clk_notifier_register.
 *
 * Returns -EINVAL if called with null arguments; otherwise, passes
 * along the return value of srcu_notifier_chain_unregister().
 */
int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
{
	struct clk_notifier *cn = NULL;
	int ret = -EINVAL;

	if (!clk || !nb)
		return -EINVAL;

	clk_prepare_lock();

	list_for_each_entry(cn, &clk_notifier_list, node)
		if (cn->clk == clk)
			break;

	if (cn->clk == clk) {
		ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);

		clk->core->notifier_count--;

		/* XXX the notifier code should handle this better */
		if (!cn->notifier_head.head) {
			srcu_cleanup_notifier_head(&cn->notifier_head);
			list_del(&cn->node);
			kfree(cn);
		}

	} else {
		ret = -ENOENT;
	}

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_notifier_unregister);

#ifdef CONFIG_OF
/**
 * struct of_clk_provider - Clock provider registration structure
 * @link: Entry in global list of clock providers
 * @node: Pointer to device tree node of clock provider
 * @get: Get clock callback.  Returns NULL or a struct clk for the
 *       given clock specifier
 * @data: context pointer to be passed into @get callback
 */
struct of_clk_provider {
	struct list_head link;

	struct device_node *node;
	struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
	void *data;
};

static const struct of_device_id __clk_of_table_sentinel
	__used __section(__clk_of_table_end);

static LIST_HEAD(of_clk_providers);
static DEFINE_MUTEX(of_clk_mutex);

struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
				     void *data)
{
	return data;
}
EXPORT_SYMBOL_GPL(of_clk_src_simple_get);

struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
{
	struct clk_onecell_data *clk_data = data;
	unsigned int idx = clkspec->args[0];

	if (idx >= clk_data->clk_num) {
		pr_err("%s: invalid clock index %d\n", __func__, idx);
		return ERR_PTR(-EINVAL);
	}

	return clk_data->clks[idx];
}
EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);

/**
 * of_clk_add_provider() - Register a clock provider for a node
 * @np: Device node pointer associated with clock provider
 * @clk_src_get: callback for decoding clock
 * @data: context pointer for @clk_src_get callback.
 */
int of_clk_add_provider(struct device_node *np,
			struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
						   void *data),
			void *data)
{
	struct of_clk_provider *cp;
	int ret;

	cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
	if (!cp)
		return -ENOMEM;

	cp->node = of_node_get(np);
	cp->data = data;
	cp->get = clk_src_get;

	mutex_lock(&of_clk_mutex);
	list_add(&cp->link, &of_clk_providers);
	mutex_unlock(&of_clk_mutex);
	pr_debug("Added clock from %s\n", np->full_name);

	ret = of_clk_set_defaults(np, true);
	if (ret < 0)
		of_clk_del_provider(np);

	return ret;
}
EXPORT_SYMBOL_GPL(of_clk_add_provider);

/**
 * of_clk_del_provider() - Remove a previously registered clock provider
 * @np: Device node pointer associated with clock provider
 */
void of_clk_del_provider(struct device_node *np)
{
	struct of_clk_provider *cp;

	mutex_lock(&of_clk_mutex);
	list_for_each_entry(cp, &of_clk_providers, link) {
		if (cp->node == np) {
			list_del(&cp->link);
			of_node_put(cp->node);
			kfree(cp);
			break;
		}
	}
	mutex_unlock(&of_clk_mutex);
}
EXPORT_SYMBOL_GPL(of_clk_del_provider);

struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
				       const char *dev_id, const char *con_id)
{
	struct of_clk_provider *provider;
	struct clk *clk = ERR_PTR(-EPROBE_DEFER);

	if (!clkspec)
		return ERR_PTR(-EINVAL);

	/* Check if we have such a provider in our array */
	mutex_lock(&of_clk_mutex);
	list_for_each_entry(provider, &of_clk_providers, link) {
		if (provider->node == clkspec->np)
			clk = provider->get(clkspec, provider->data);
		if (!IS_ERR(clk)) {
			clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
					       con_id);

			if (!IS_ERR(clk) && !__clk_get(clk)) {
				__clk_free_clk(clk);
				clk = ERR_PTR(-ENOENT);
			}

			break;
		}
	}
	mutex_unlock(&of_clk_mutex);

	return clk;
}

/**
 * of_clk_get_from_provider() - Lookup a clock from a clock provider
 * @clkspec: pointer to a clock specifier data structure
 *
 * This function looks up a struct clk from the registered list of clock
 * providers, an input is a clock specifier data structure as returned
 * from the of_parse_phandle_with_args() function call.
 */
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
{
	return __of_clk_get_from_provider(clkspec, NULL, __func__);
}

int of_clk_get_parent_count(struct device_node *np)
{
	return of_count_phandle_with_args(np, "clocks", "#clock-cells");
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_count);

const char *of_clk_get_parent_name(struct device_node *np, int index)
{
	struct of_phandle_args clkspec;
	struct property *prop;
	const char *clk_name;
	const __be32 *vp;
	u32 pv;
	int rc;
	int count;

	if (index < 0)
		return NULL;

	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
					&clkspec);
	if (rc)
		return NULL;

	index = clkspec.args_count ? clkspec.args[0] : 0;
	count = 0;

	/* if there is an indices property, use it to transfer the index
	 * specified into an array offset for the clock-output-names property.
	 */
	of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
		if (index == pv) {
			index = count;
			break;
		}
		count++;
	}

	if (of_property_read_string_index(clkspec.np, "clock-output-names",
					  index,
					  &clk_name) < 0)
		clk_name = clkspec.np->name;

	of_node_put(clkspec.np);
	return clk_name;
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_name);

/**
 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
 * number of parents
 * @np: Device node pointer associated with clock provider
 * @parents: pointer to char array that hold the parents' names
 * @size: size of the @parents array
 *
 * Return: number of parents for the clock node.
 */
int of_clk_parent_fill(struct device_node *np, const char **parents,
		       unsigned int size)
{
	unsigned int i = 0;

	while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
		i++;

	return i;
}
EXPORT_SYMBOL_GPL(of_clk_parent_fill);

struct clock_provider {
	of_clk_init_cb_t clk_init_cb;
	struct device_node *np;
	struct list_head node;
};

static LIST_HEAD(clk_provider_list);

/*
 * This function looks for a parent clock. If there is one, then it
 * checks that the provider for this parent clock was initialized, in
 * this case the parent clock will be ready.
 */
static int parent_ready(struct device_node *np)
{
	int i = 0;

	while (true) {
		struct clk *clk = of_clk_get(np, i);

		/* this parent is ready we can check the next one */
		if (!IS_ERR(clk)) {
			clk_put(clk);
			i++;
			continue;
		}

		/* at least one parent is not ready, we exit now */
		if (PTR_ERR(clk) == -EPROBE_DEFER)
			return 0;

		/*
		 * Here we make assumption that the device tree is
		 * written correctly. So an error means that there is
		 * no more parent. As we didn't exit yet, then the
		 * previous parent are ready. If there is no clock
		 * parent, no need to wait for them, then we can
		 * consider their absence as being ready
		 */
		return 1;
	}
}

/**
 * of_clk_init() - Scan and init clock providers from the DT
 * @matches: array of compatible values and init functions for providers.
 *
 * This function scans the device tree for matching clock providers
 * and calls their initialization functions. It also does it by trying
 * to follow the dependencies.
 */
void __init of_clk_init(const struct of_device_id *matches)
{
	const struct of_device_id *match;
	struct device_node *np;
	struct clock_provider *clk_provider, *next;
	bool is_init_done;
	bool force = false;

	if (!matches)
		matches = &__clk_of_table;

	/* First prepare the list of the clocks providers */
	for_each_matching_node_and_match(np, matches, &match) {
		struct clock_provider *parent =
			kzalloc(sizeof(struct clock_provider),	GFP_KERNEL);

		parent->clk_init_cb = match->data;
		parent->np = np;
		list_add_tail(&parent->node, &clk_provider_list);
	}

	while (!list_empty(&clk_provider_list)) {
		is_init_done = false;
		list_for_each_entry_safe(clk_provider, next,
					&clk_provider_list, node) {
			if (force || parent_ready(clk_provider->np)) {

				clk_provider->clk_init_cb(clk_provider->np);
				of_clk_set_defaults(clk_provider->np, true);

				list_del(&clk_provider->node);
				kfree(clk_provider);
				is_init_done = true;
			}
		}

		/*
		 * We didn't manage to initialize any of the
		 * remaining providers during the last loop, so now we
		 * initialize all the remaining ones unconditionally
		 * in case the clock parent was not mandatory
		 */
		if (!is_init_done)
			force = true;
	}
}
#endif