summaryrefslogtreecommitdiffstats
path: root/drivers/clk/clk.c
blob: 3d751ae5bc703280eb2918afea367277641cf933 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
 *
 * Standard functionality for the common clock API.  See Documentation/driver-api/clk.rst
 */

#include <linux/clk.h>
#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/pm_runtime.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);

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

/***    private data structures    ***/

struct clk_parent_map {
	const struct clk_hw	*hw;
	struct clk_core		*core;
	const char		*fw_name;
	const char		*name;
	int			index;
};

struct clk_core {
	const char		*name;
	const struct clk_ops	*ops;
	struct clk_hw		*hw;
	struct module		*owner;
	struct device		*dev;
	struct device_node	*of_node;
	struct clk_core		*parent;
	struct clk_parent_map	*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;
	bool			orphan;
	bool			rpm_enabled;
	unsigned int		enable_count;
	unsigned int		prepare_count;
	unsigned int		protect_count;
	unsigned long		min_rate;
	unsigned long		max_rate;
	unsigned long		accuracy;
	int			phase;
	struct clk_duty		duty;
	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;
	struct device *dev;
	const char *dev_id;
	const char *con_id;
	unsigned long min_rate;
	unsigned long max_rate;
	unsigned int exclusive_count;
	struct hlist_node clks_node;
};

/***           runtime pm          ***/
static int clk_pm_runtime_get(struct clk_core *core)
{
	int ret;

	if (!core->rpm_enabled)
		return 0;

	ret = pm_runtime_get_sync(core->dev);
	if (ret < 0) {
		pm_runtime_put_noidle(core->dev);
		return ret;
	}
	return 0;
}

static void clk_pm_runtime_put(struct clk_core *core)
{
	if (!core->rpm_enabled)
		return;

	pm_runtime_put_sync(core->dev);
}

/***           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)
	__acquires(enable_lock)
{
	unsigned long flags;

	/*
	 * On UP systems, spin_trylock_irqsave() always returns true, even if
	 * we already hold the lock. So, in that case, we rely only on
	 * reference counting.
	 */
	if (!IS_ENABLED(CONFIG_SMP) ||
	    !spin_trylock_irqsave(&enable_lock, flags)) {
		if (enable_owner == current) {
			enable_refcnt++;
			__acquire(enable_lock);
			if (!IS_ENABLED(CONFIG_SMP))
				local_save_flags(flags);
			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)
	__releases(enable_lock)
{
	WARN_ON_ONCE(enable_owner != current);
	WARN_ON_ONCE(enable_refcnt == 0);

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

static bool clk_core_rate_is_protected(struct clk_core *core)
{
	return core->protect_count;
}

static bool clk_core_is_prepared(struct clk_core *core)
{
	bool ret = false;

	/*
	 * .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;

	if (!clk_pm_runtime_get(core)) {
		ret = core->ops->is_prepared(core->hw);
		clk_pm_runtime_put(core);
	}

	return ret;
}

static bool clk_core_is_enabled(struct clk_core *core)
{
	bool ret = false;

	/*
	 * .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;

	/*
	 * Check if clock controller's device is runtime active before
	 * calling .is_enabled callback. If not, assume that clock is
	 * disabled, because we might be called from atomic context, from
	 * which pm_runtime_get() is not allowed.
	 * This function is called mainly from clk_disable_unused_subtree,
	 * which ensures proper runtime pm activation of controller before
	 * taking enable spinlock, but the below check is needed if one tries
	 * to call it from other places.
	 */
	if (core->rpm_enabled) {
		pm_runtime_get_noresume(core->dev);
		if (!pm_runtime_active(core->dev)) {
			ret = false;
			goto done;
		}
	}

	ret = core->ops->is_enabled(core->hw);
done:
	if (core->rpm_enabled)
		pm_runtime_put(core->dev);

	return ret;
}

/***    helper functions   ***/

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

const char *clk_hw_get_name(const struct clk_hw *hw)
{
	return hw->core->name;
}
EXPORT_SYMBOL_GPL(clk_hw_get_name);

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

unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
{
	return hw->core->num_parents;
}
EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);

struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
{
	return hw->core->parent ? hw->core->parent->hw : NULL;
}
EXPORT_SYMBOL_GPL(clk_hw_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;
}

#ifdef CONFIG_OF
static int of_parse_clkspec(const struct device_node *np, int index,
			    const char *name, struct of_phandle_args *out_args);
static struct clk_hw *
of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
#else
static inline int of_parse_clkspec(const struct device_node *np, int index,
				   const char *name,
				   struct of_phandle_args *out_args)
{
	return -ENOENT;
}
static inline struct clk_hw *
of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
{
	return ERR_PTR(-ENOENT);
}
#endif

/**
 * clk_core_get - Find the clk_core parent of a clk
 * @core: clk to find parent of
 * @p_index: parent index to search for
 *
 * This is the preferred method for clk providers to find the parent of a
 * clk when that parent is external to the clk controller. The parent_names
 * array is indexed and treated as a local name matching a string in the device
 * node's 'clock-names' property or as the 'con_id' matching the device's
 * dev_name() in a clk_lookup. This allows clk providers to use their own
 * namespace instead of looking for a globally unique parent string.
 *
 * For example the following DT snippet would allow a clock registered by the
 * clock-controller@c001 that has a clk_init_data::parent_data array
 * with 'xtal' in the 'name' member to find the clock provided by the
 * clock-controller@f00abcd without needing to get the globally unique name of
 * the xtal clk.
 *
 *      parent: clock-controller@f00abcd {
 *              reg = <0xf00abcd 0xabcd>;
 *              #clock-cells = <0>;
 *      };
 *
 *      clock-controller@c001 {
 *              reg = <0xc001 0xf00d>;
 *              clocks = <&parent>;
 *              clock-names = "xtal";
 *              #clock-cells = <1>;
 *      };
 *
 * Returns: -ENOENT when the provider can't be found or the clk doesn't
 * exist in the provider or the name can't be found in the DT node or
 * in a clkdev lookup. NULL when the provider knows about the clk but it
 * isn't provided on this system.
 * A valid clk_core pointer when the clk can be found in the provider.
 */
static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
{
	const char *name = core->parents[p_index].fw_name;
	int index = core->parents[p_index].index;
	struct clk_hw *hw = ERR_PTR(-ENOENT);
	struct device *dev = core->dev;
	const char *dev_id = dev ? dev_name(dev) : NULL;
	struct device_node *np = core->of_node;
	struct of_phandle_args clkspec;

	if (np && (name || index >= 0) &&
	    !of_parse_clkspec(np, index, name, &clkspec)) {
		hw = of_clk_get_hw_from_clkspec(&clkspec);
		of_node_put(clkspec.np);
	} else if (name) {
		/*
		 * If the DT search above couldn't find the provider fallback to
		 * looking up via clkdev based clk_lookups.
		 */
		hw = clk_find_hw(dev_id, name);
	}

	if (IS_ERR(hw))
		return ERR_CAST(hw);

	return hw->core;
}

static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
{
	struct clk_parent_map *entry = &core->parents[index];
	struct clk_core *parent;

	if (entry->hw) {
		parent = entry->hw->core;
		/*
		 * We have a direct reference but it isn't registered yet?
		 * Orphan it and let clk_reparent() update the orphan status
		 * when the parent is registered.
		 */
		if (!parent)
			parent = ERR_PTR(-EPROBE_DEFER);
	} else {
		parent = clk_core_get(core, index);
		if (PTR_ERR(parent) == -ENOENT && entry->name)
			parent = clk_core_lookup(entry->name);
	}

	/* Only cache it if it's not an error */
	if (!IS_ERR(parent))
		entry->core = parent;
}

static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
							 u8 index)
{
	if (!core || index >= core->num_parents || !core->parents)
		return NULL;

	if (!core->parents[index].core)
		clk_core_fill_parent_index(core, index);

	return core->parents[index].core;
}

struct clk_hw *
clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
{
	struct clk_core *parent;

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

	return !parent ? NULL : parent->hw;
}
EXPORT_SYMBOL_GPL(clk_hw_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)
{
	if (!core)
		return 0;

	if (!core->num_parents || core->parent)
		return core->rate;

	/*
	 * Clk must have a parent because num_parents > 0 but the parent isn't
	 * known yet. Best to return 0 as the rate of this clk until we can
	 * properly recalc the rate based on the parent's rate.
	 */
	return 0;
}

unsigned long clk_hw_get_rate(const struct clk_hw *hw)
{
	return clk_core_get_rate_nolock(hw->core);
}
EXPORT_SYMBOL_GPL(clk_hw_get_rate);

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

	return core->accuracy;
}

unsigned long clk_hw_get_flags(const struct clk_hw *hw)
{
	return hw->core->flags;
}
EXPORT_SYMBOL_GPL(clk_hw_get_flags);

bool clk_hw_is_prepared(const struct clk_hw *hw)
{
	return clk_core_is_prepared(hw->core);
}
EXPORT_SYMBOL_GPL(clk_hw_is_prepared);

bool clk_hw_rate_is_protected(const struct clk_hw *hw)
{
	return clk_core_rate_is_protected(hw->core);
}
EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);

bool clk_hw_is_enabled(const struct clk_hw *hw)
{
	return clk_core_is_enabled(hw->core);
}
EXPORT_SYMBOL_GPL(clk_hw_is_enabled);

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;
}

int clk_mux_determine_rate_flags(struct clk_hw *hw,
				 struct clk_rate_request *req,
				 unsigned long flags)
{
	struct clk_core *core = hw->core, *parent, *best_parent = NULL;
	int i, num_parents, ret;
	unsigned long best = 0;
	struct clk_rate_request parent_req = *req;

	/* 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) {
			ret = __clk_determine_rate(parent ? parent->hw : NULL,
						   &parent_req);
			if (ret)
				return ret;

			best = parent_req.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_req = *req;
			ret = __clk_determine_rate(parent->hw, &parent_req);
			if (ret)
				continue;
		} else {
			parent_req.rate = clk_core_get_rate_nolock(parent);
		}

		if (mux_is_better_rate(req->rate, parent_req.rate,
				       best, flags)) {
			best_parent = parent;
			best = parent_req.rate;
		}
	}

	if (!best_parent)
		return -EINVAL;

out:
	if (best_parent)
		req->best_parent_hw = best_parent->hw;
	req->best_parent_rate = best;
	req->rate = best;

	return 0;
}
EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);

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;

	lockdep_assert_held(&prepare_lock);

	*min_rate = core->min_rate;
	*max_rate = core->max_rate;

	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);
}

void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
			   unsigned long max_rate)
{
	hw->core->min_rate = min_rate;
	hw->core->max_rate = max_rate;
}
EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);

/*
 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
 * @hw: mux type clk to determine rate on
 * @req: rate request, also used to return preferred parent and frequencies
 *
 * 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.
 *
 * Returns: 0 on success, -EERROR value on error
 */
int __clk_mux_determine_rate(struct clk_hw *hw,
			     struct clk_rate_request *req)
{
	return clk_mux_determine_rate_flags(hw, req, 0);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);

int __clk_mux_determine_rate_closest(struct clk_hw *hw,
				     struct clk_rate_request *req)
{
	return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);

/***        clk api        ***/

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

	if (!core)
		return;

	if (WARN(core->protect_count == 0,
	    "%s already unprotected\n", core->name))
		return;

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

	clk_core_rate_unprotect(core->parent);
}

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

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return -EINVAL;

	if (core->protect_count == 0)
		return 0;

	ret = core->protect_count;
	core->protect_count = 1;
	clk_core_rate_unprotect(core);

	return ret;
}

/**
 * clk_rate_exclusive_put - release exclusivity over clock rate control
 * @clk: the clk over which the exclusivity is released
 *
 * clk_rate_exclusive_put() completes a critical section during which a clock
 * consumer cannot tolerate any other consumer making any operation on the
 * clock which could result in a rate change or rate glitch. Exclusive clocks
 * cannot have their rate changed, either directly or indirectly due to changes
 * further up the parent chain of clocks. As a result, clocks up parent chain
 * also get under exclusive control of the calling consumer.
 *
 * If exlusivity is claimed more than once on clock, even by the same consumer,
 * the rate effectively gets locked as exclusivity can't be preempted.
 *
 * Calls to clk_rate_exclusive_put() must be balanced with calls to
 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
 * error status.
 */
void clk_rate_exclusive_put(struct clk *clk)
{
	if (!clk)
		return;

	clk_prepare_lock();

	/*
	 * if there is something wrong with this consumer protect count, stop
	 * here before messing with the provider
	 */
	if (WARN_ON(clk->exclusive_count <= 0))
		goto out;

	clk_core_rate_unprotect(clk->core);
	clk->exclusive_count--;
out:
	clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);

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

	if (!core)
		return;

	if (core->protect_count == 0)
		clk_core_rate_protect(core->parent);

	core->protect_count++;
}

static void clk_core_rate_restore_protect(struct clk_core *core, int count)
{
	lockdep_assert_held(&prepare_lock);

	if (!core)
		return;

	if (count == 0)
		return;

	clk_core_rate_protect(core);
	core->protect_count = count;
}

/**
 * clk_rate_exclusive_get - get exclusivity over the clk rate control
 * @clk: the clk over which the exclusity of rate control is requested
 *
 * clk_rate_exclusive_get() begins a critical section during which a clock
 * consumer cannot tolerate any other consumer making any operation on the
 * clock which could result in a rate change or rate glitch. Exclusive clocks
 * cannot have their rate changed, either directly or indirectly due to changes
 * further up the parent chain of clocks. As a result, clocks up parent chain
 * also get under exclusive control of the calling consumer.
 *
 * If exlusivity is claimed more than once on clock, even by the same consumer,
 * the rate effectively gets locked as exclusivity can't be preempted.
 *
 * Calls to clk_rate_exclusive_get() should be balanced with calls to
 * clk_rate_exclusive_put(). Calls to this function may sleep.
 * Returns 0 on success, -EERROR otherwise
 */
int clk_rate_exclusive_get(struct clk *clk)
{
	if (!clk)
		return 0;

	clk_prepare_lock();
	clk_core_rate_protect(clk->core);
	clk->exclusive_count++;
	clk_prepare_unlock();

	return 0;
}
EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);

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

	if (!core)
		return;

	if (WARN(core->prepare_count == 0,
	    "%s already unprepared\n", core->name))
		return;

	if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
	    "Unpreparing critical %s\n", core->name))
		return;

	if (core->flags & CLK_SET_RATE_GATE)
		clk_core_rate_unprotect(core);

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

	WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);

	trace_clk_unprepare(core);

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

	clk_pm_runtime_put(core);

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

static void clk_core_unprepare_lock(struct clk_core *core)
{
	clk_prepare_lock();
	clk_core_unprepare(core);
	clk_prepare_unlock();
}

/**
 * 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_core_unprepare_lock(clk->core);
}
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_pm_runtime_get(core);
		if (ret)
			return ret;

		ret = clk_core_prepare(core->parent);
		if (ret)
			goto runtime_put;

		trace_clk_prepare(core);

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

		trace_clk_prepare_complete(core);

		if (ret)
			goto unprepare;
	}

	core->prepare_count++;

	/*
	 * CLK_SET_RATE_GATE is a special case of clock protection
	 * Instead of a consumer claiming exclusive rate control, it is
	 * actually the provider which prevents any consumer from making any
	 * operation which could result in a rate change or rate glitch while
	 * the clock is prepared.
	 */
	if (core->flags & CLK_SET_RATE_GATE)
		clk_core_rate_protect(core);

	return 0;
unprepare:
	clk_core_unprepare(core->parent);
runtime_put:
	clk_pm_runtime_put(core);
	return ret;
}

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

	clk_prepare_lock();
	ret = clk_core_prepare(core);
	clk_prepare_unlock();

	return ret;
}

/**
 * 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)
{
	if (!clk)
		return 0;

	return clk_core_prepare_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_prepare);

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

	if (!core)
		return;

	if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
		return;

	if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
	    "Disabling critical %s\n", core->name))
		return;

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

	trace_clk_disable_rcuidle(core);

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

	trace_clk_disable_complete_rcuidle(core);

	clk_core_disable(core->parent);
}

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

	flags = clk_enable_lock();
	clk_core_disable(core);
	clk_enable_unlock(flags);
}

/**
 * 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)
{
	if (IS_ERR_OR_NULL(clk))
		return;

	clk_core_disable_lock(clk->core);
}
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(core->prepare_count == 0,
	    "Enabling unprepared %s\n", core->name))
		return -ESHUTDOWN;

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

		if (ret)
			return ret;

		trace_clk_enable_rcuidle(core);

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

		trace_clk_enable_complete_rcuidle(core);

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

	core->enable_count++;
	return 0;
}

static int clk_core_enable_lock(struct clk_core *core)
{
	unsigned long flags;
	int ret;

	flags = clk_enable_lock();
	ret = clk_core_enable(core);
	clk_enable_unlock(flags);

	return ret;
}

/**
 * clk_gate_restore_context - restore context for poweroff
 * @hw: the clk_hw pointer of clock whose state is to be restored
 *
 * The clock gate restore context function enables or disables
 * the gate clocks based on the enable_count. This is done in cases
 * where the clock context is lost and based on the enable_count
 * the clock either needs to be enabled/disabled. This
 * helps restore the state of gate clocks.
 */
void clk_gate_restore_context(struct clk_hw *hw)
{
	struct clk_core *core = hw->core;

	if (core->enable_count)
		core->ops->enable(hw);
	else
		core->ops->disable(hw);
}
EXPORT_SYMBOL_GPL(clk_gate_restore_context);

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

	hlist_for_each_entry(child, &core->children, child_node) {
		ret = clk_core_save_context(child);
		if (ret < 0)
			return ret;
	}

	if (core->ops && core->ops->save_context)
		ret = core->ops->save_context(core->hw);

	return ret;
}

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

	if (core->ops && core->ops->restore_context)
		core->ops->restore_context(core->hw);

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

/**
 * clk_save_context - save clock context for poweroff
 *
 * Saves the context of the clock register for powerstates in which the
 * contents of the registers will be lost. Occurs deep within the suspend
 * code.  Returns 0 on success.
 */
int clk_save_context(void)
{
	struct clk_core *clk;
	int ret;

	hlist_for_each_entry(clk, &clk_root_list, child_node) {
		ret = clk_core_save_context(clk);
		if (ret < 0)
			return ret;
	}

	hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
		ret = clk_core_save_context(clk);
		if (ret < 0)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(clk_save_context);

/**
 * clk_restore_context - restore clock context after poweroff
 *
 * Restore the saved clock context upon resume.
 *
 */
void clk_restore_context(void)
{
	struct clk_core *core;

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

	hlist_for_each_entry(core, &clk_orphan_list, child_node)
		clk_core_restore_context(core);
}
EXPORT_SYMBOL_GPL(clk_restore_context);

/**
 * 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)
{
	if (!clk)
		return 0;

	return clk_core_enable_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_enable);

/**
 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
 * @clk: clock source
 *
 * Returns true if clk_prepare() implicitly enables the clock, effectively
 * making clk_enable()/clk_disable() no-ops, false otherwise.
 *
 * This is of interest mainly to power management code where actually
 * disabling the clock also requires unpreparing it to have any material
 * effect.
 *
 * Regardless of the value returned here, the caller must always invoke
 * clk_enable() or clk_prepare_enable()  and counterparts for usage counts
 * to be right.
 */
bool clk_is_enabled_when_prepared(struct clk *clk)
{
	return clk && !(clk->core->ops->enable && clk->core->ops->disable);
}
EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);

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

	ret = clk_core_prepare_lock(core);
	if (ret)
		return ret;

	ret = clk_core_enable_lock(core);
	if (ret)
		clk_core_unprepare_lock(core);

	return ret;
}

static void clk_core_disable_unprepare(struct clk_core *core)
{
	clk_core_disable_lock(core);
	clk_core_unprepare_lock(core);
}

static void __init 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_pm_runtime_get(core))
		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);
	}

	clk_pm_runtime_put(core);
}

static void __init 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);

	if (core->flags & CLK_OPS_PARENT_ENABLE)
		clk_core_prepare_enable(core->parent);

	if (clk_pm_runtime_get(core))
		goto unprepare_out;

	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);
	clk_pm_runtime_put(core);
unprepare_out:
	if (core->flags & CLK_OPS_PARENT_ENABLE)
		clk_core_disable_unprepare(core->parent);
}

static bool clk_ignore_unused __initdata;
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 __init 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);

static int clk_core_determine_round_nolock(struct clk_core *core,
					   struct clk_rate_request *req)
{
	long rate;

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	/*
	 * At this point, core protection will be disabled if
	 * - if the provider is not protected at all
	 * - if the calling consumer is the only one which has exclusivity
	 *   over the provider
	 */
	if (clk_core_rate_is_protected(core)) {
		req->rate = core->rate;
	} else if (core->ops->determine_rate) {
		return core->ops->determine_rate(core->hw, req);
	} else if (core->ops->round_rate) {
		rate = core->ops->round_rate(core->hw, req->rate,
					     &req->best_parent_rate);
		if (rate < 0)
			return rate;

		req->rate = rate;
	} else {
		return -EINVAL;
	}

	return 0;
}

static void clk_core_init_rate_req(struct clk_core * const core,
				   struct clk_rate_request *req)
{
	struct clk_core *parent;

	if (WARN_ON(!core || !req))
		return;

	parent = core->parent;
	if (parent) {
		req->best_parent_hw = parent->hw;
		req->best_parent_rate = parent->rate;
	} else {
		req->best_parent_hw = NULL;
		req->best_parent_rate = 0;
	}
}

static bool clk_core_can_round(struct clk_core * const core)
{
	return core->ops->determine_rate || core->ops->round_rate;
}

static int clk_core_round_rate_nolock(struct clk_core *core,
				      struct clk_rate_request *req)
{
	lockdep_assert_held(&prepare_lock);

	if (!core) {
		req->rate = 0;
		return 0;
	}

	clk_core_init_rate_req(core, req);

	if (clk_core_can_round(core))
		return clk_core_determine_round_nolock(core, req);
	else if (core->flags & CLK_SET_RATE_PARENT)
		return clk_core_round_rate_nolock(core->parent, req);

	req->rate = core->rate;
	return 0;
}

/**
 * __clk_determine_rate - get the closest rate actually supported by a clock
 * @hw: determine the rate of this clock
 * @req: target rate request
 *
 * Useful for clk_ops such as .set_rate and .determine_rate.
 */
int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
	if (!hw) {
		req->rate = 0;
		return 0;
	}

	return clk_core_round_rate_nolock(hw->core, req);
}
EXPORT_SYMBOL_GPL(__clk_determine_rate);

/**
 * clk_hw_round_rate() - round the given rate for a hw clk
 * @hw: the hw 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.
 *
 * Context: prepare_lock must be held.
 *          For clk providers to call from within clk_ops such as .round_rate,
 *          .determine_rate.
 *
 * Return: returns rounded rate of hw clk if clk supports round_rate operation
 *         else returns the parent rate.
 */
unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
{
	int ret;
	struct clk_rate_request req;

	clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
	req.rate = rate;

	ret = clk_core_round_rate_nolock(hw->core, &req);
	if (ret)
		return 0;

	return req.rate;
}
EXPORT_SYMBOL_GPL(clk_hw_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)
{
	struct clk_rate_request req;
	int ret;

	if (!clk)
		return 0;

	clk_prepare_lock();

	if (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

	clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
	req.rate = rate;

	ret = clk_core_round_rate_nolock(clk->core, &req);

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	clk_prepare_unlock();

	if (ret)
		return ret;

	return req.rate;
}
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);
			if (ret & NOTIFY_STOP_MASK)
				return ret;
		}
	}

	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_recalc(struct clk_core *core)
{
	if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
		__clk_recalc_accuracies(core);

	return clk_core_get_accuracy_no_lock(core);
}

/**
 * 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)
{
	long accuracy;

	if (!clk)
		return 0;

	clk_prepare_lock();
	accuracy = clk_core_get_accuracy_recalc(clk->core);
	clk_prepare_unlock();

	return accuracy;
}
EXPORT_SYMBOL_GPL(clk_get_accuracy);

static unsigned long clk_recalc(struct clk_core *core,
				unsigned long parent_rate)
{
	unsigned long rate = parent_rate;

	if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
		rate = core->ops->recalc_rate(core->hw, parent_rate);
		clk_pm_runtime_put(core);
	}
	return 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_recalc(struct clk_core *core)
{
	if (core && (core->flags & CLK_GET_RATE_NOCACHE))
		__clk_recalc_rates(core, 0);

	return clk_core_get_rate_nolock(core);
}

/**
 * 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)
{
	unsigned long rate;

	if (!clk)
		return 0;

	clk_prepare_lock();
	rate = clk_core_get_rate_recalc(clk->core);
	clk_prepare_unlock();

	return rate;
}
EXPORT_SYMBOL_GPL(clk_get_rate);

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

	if (!parent)
		return -EINVAL;

	for (i = 0; i < core->num_parents; i++) {
		/* Found it first try! */
		if (core->parents[i].core == parent)
			return i;

		/* Something else is here, so keep looking */
		if (core->parents[i].core)
			continue;

		/* Maybe core hasn't been cached but the hw is all we know? */
		if (core->parents[i].hw) {
			if (core->parents[i].hw == parent->hw)
				break;

			/* Didn't match, but we're expecting a clk_hw */
			continue;
		}

		/* Maybe it hasn't been cached (clk_set_parent() path) */
		if (parent == clk_core_get(core, i))
			break;

		/* Fallback to comparing globally unique names */
		if (core->parents[i].name &&
		    !strcmp(parent->name, core->parents[i].name))
			break;
	}

	if (i == core->num_parents)
		return -EINVAL;

	core->parents[i].core = parent;
	return i;
}

/**
 * clk_hw_get_parent_index - return the index of the parent clock
 * @hw: clk_hw associated with the clk being consumed
 *
 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
 * clock does not have a current parent.
 */
int clk_hw_get_parent_index(struct clk_hw *hw)
{
	struct clk_hw *parent = clk_hw_get_parent(hw);

	if (WARN_ON(parent == NULL))
		return -EINVAL;

	return clk_fetch_parent_index(hw->core, parent->core);
}
EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);

/*
 * Update the orphan status of @core and all its children.
 */
static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
{
	struct clk_core *child;

	core->orphan = is_orphan;

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

static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
	bool was_orphan = core->orphan;

	hlist_del(&core->child_node);

	if (new_parent) {
		bool becomes_orphan = new_parent->orphan;

		/* 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);

		if (was_orphan != becomes_orphan)
			clk_core_update_orphan_status(core, becomes_orphan);
	} else {
		hlist_add_head(&core->child_node, &clk_orphan_list);
		if (!was_orphan)
			clk_core_update_orphan_status(core, true);
	}

	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;

	/*
	 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
	 *
	 * 2. 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.
	 */

	/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
	if (core->flags & CLK_OPS_PARENT_ENABLE) {
		clk_core_prepare_enable(old_parent);
		clk_core_prepare_enable(parent);
	}

	/* migrate prepare count if > 0 */
	if (core->prepare_count) {
		clk_core_prepare_enable(parent);
		clk_core_enable_lock(core);
	}

	/* 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)
{
	/*
	 * Finish the migration of prepare state and undo the changes done
	 * for preventing a race with clk_enable().
	 */
	if (core->prepare_count) {
		clk_core_disable_lock(core);
		clk_core_disable_unprepare(old_parent);
	}

	/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
	if (core->flags & CLK_OPS_PARENT_ENABLE) {
		clk_core_disable_unprepare(parent);
		clk_core_disable_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);
		__clk_set_parent_after(core, old_parent, 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;
	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 (clk_core_can_round(core)) {
		struct clk_rate_request req;

		req.rate = rate;
		req.min_rate = min_rate;
		req.max_rate = max_rate;

		clk_core_init_rate_req(core, &req);

		ret = clk_core_determine_round_nolock(core, &req);
		if (ret < 0)
			return NULL;

		best_parent_rate = req.best_parent_rate;
		new_rate = req.rate;
		parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;

		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;
	struct clk_core *parent = NULL;

	old_rate = core->rate;

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

	if (clk_pm_runtime_get(core))
		return;

	if (core->flags & CLK_SET_RATE_UNGATE) {
		unsigned long flags;

		clk_core_prepare(core);
		flags = clk_enable_lock();
		clk_core_enable(core);
		clk_enable_unlock(flags);
	}

	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);
	}

	if (core->flags & CLK_OPS_PARENT_ENABLE)
		clk_core_prepare_enable(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->flags & CLK_SET_RATE_UNGATE) {
		unsigned long flags;

		flags = clk_enable_lock();
		clk_core_disable(core);
		clk_enable_unlock(flags);
		clk_core_unprepare(core);
	}

	if (core->flags & CLK_OPS_PARENT_ENABLE)
		clk_core_disable_unprepare(parent);

	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);

	clk_pm_runtime_put(core);
}

static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
						     unsigned long req_rate)
{
	int ret, cnt;
	struct clk_rate_request req;

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	/* simulate what the rate would be if it could be freely set */
	cnt = clk_core_rate_nuke_protect(core);
	if (cnt < 0)
		return cnt;

	clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
	req.rate = req_rate;

	ret = clk_core_round_rate_nolock(core, &req);

	/* restore the protection */
	clk_core_rate_restore_protect(core, cnt);

	return ret ? 0 : req.rate;
}

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

	if (!core)
		return 0;

	rate = clk_core_req_round_rate_nolock(core, req_rate);

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

	/* fail on a direct rate set of a protected provider */
	if (clk_core_rate_is_protected(core))
		return -EBUSY;

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

	ret = clk_pm_runtime_get(core);
	if (ret)
		return ret;

	/* 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);
		ret = -EBUSY;
		goto err;
	}

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

	core->req_rate = req_rate;
err:
	clk_pm_runtime_put(core);

	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();

	if (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

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

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate);

/**
 * clk_set_rate_exclusive - specify a new rate and get exclusive control
 * @clk: the clk whose rate is being changed
 * @rate: the new rate for clk
 *
 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
 * within a critical section
 *
 * This can be used initially to ensure that at least 1 consumer is
 * satisfied when several consumers are competing for exclusivity over the
 * same clock provider.
 *
 * The exclusivity is not applied if setting the rate failed.
 *
 * Calls to clk_rate_exclusive_get() should be balanced with calls to
 * clk_rate_exclusive_put().
 *
 * Returns 0 on success, -EERROR otherwise.
 */
int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
{
	int ret;

	if (!clk)
		return 0;

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

	/*
	 * The temporary protection removal is not here, on purpose
	 * This function is meant to be used instead of clk_rate_protect,
	 * so before the consumer code path protect the clock provider
	 */

	ret = clk_core_set_rate_nolock(clk->core, rate);
	if (!ret) {
		clk_core_rate_protect(clk->core);
		clk->exclusive_count++;
	}

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);

/**
 * 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;
	unsigned long old_min, old_max, rate;

	if (!clk)
		return 0;

	trace_clk_set_rate_range(clk->core, min, max);

	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 (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

	/* Save the current values in case we need to rollback the change */
	old_min = clk->min_rate;
	old_max = clk->max_rate;
	clk->min_rate = min;
	clk->max_rate = max;

	rate = clk_core_get_rate_nolock(clk->core);
	if (rate < min || rate > max) {
		/*
		 * FIXME:
		 * We are in bit of trouble here, current rate is outside the
		 * the requested range. We are going try to request appropriate
		 * range boundary but there is a catch. It may fail for the
		 * usual reason (clock broken, clock protected, etc) but also
		 * because:
		 * - round_rate() was not favorable and fell on the wrong
		 *   side of the boundary
		 * - the determine_rate() callback does not really check for
		 *   this corner case when determining the rate
		 */

		if (rate < min)
			rate = min;
		else
			rate = max;

		ret = clk_core_set_rate_nolock(clk->core, rate);
		if (ret) {
			/* rollback the changes */
			clk->min_rate = old_min;
			clk->max_rate = old_max;
		}
	}

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	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;

	trace_clk_set_min_rate(clk->core, rate);

	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;

	trace_clk_set_max_rate(clk->core, rate);

	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;

	if (!clk)
		return NULL;

	clk_prepare_lock();
	/* TODO: Create a per-user clk and change callers to call clk_put */
	parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
	clk_prepare_unlock();

	return parent;
}
EXPORT_SYMBOL_GPL(clk_get_parent);

static struct clk_core *__clk_init_parent(struct clk_core *core)
{
	u8 index = 0;

	if (core->num_parents > 1 && core->ops->get_parent)
		index = core->ops->get_parent(core->hw);

	return clk_core_get_parent_by_index(core, index);
}

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;
	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->parents[i].name, parent_core->name))
			return true;

	return false;
}
EXPORT_SYMBOL_GPL(clk_has_parent);

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

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	if (core->parent == parent)
		return 0;

	/* verify ops for multi-parent clks */
	if (core->num_parents > 1 && !core->ops->set_parent)
		return -EPERM;

	/* check that we are allowed to re-parent if the clock is in use */
	if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
		return -EBUSY;

	if (clk_core_rate_is_protected(core))
		return -EBUSY;

	/* try finding the new parent index */
	if (parent) {
		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 p_index;
		}
		p_rate = parent->rate;
	}

	ret = clk_pm_runtime_get(core);
	if (ret)
		return ret;

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

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

	/* 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);
	}

runtime_put:
	clk_pm_runtime_put(core);

	return ret;
}

int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
{
	return clk_core_set_parent_nolock(hw->core, parent->core);
}
EXPORT_SYMBOL_GPL(clk_hw_set_parent);

/**
 * 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)
{
	int ret;

	if (!clk)
		return 0;

	clk_prepare_lock();

	if (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

	ret = clk_core_set_parent_nolock(clk->core,
					 parent ? parent->core : NULL);

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_parent);

static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
{
	int ret = -EINVAL;

	lockdep_assert_held(&prepare_lock);

	if (!core)
		return 0;

	if (clk_core_rate_is_protected(core))
		return -EBUSY;

	trace_clk_set_phase(core, degrees);

	if (core->ops->set_phase) {
		ret = core->ops->set_phase(core->hw, degrees);
		if (!ret)
			core->phase = degrees;
	}

	trace_clk_set_phase_complete(core, degrees);

	return ret;
}

/**
 * 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;

	if (!clk)
		return 0;

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

	clk_prepare_lock();

	if (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

	ret = clk_core_set_phase_nolock(clk->core, degrees);

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_phase);

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

	lockdep_assert_held(&prepare_lock);
	if (!core->ops->get_phase)
		return 0;

	/* Always try to update cached phase if possible */
	ret = core->ops->get_phase(core->hw);
	if (ret >= 0)
		core->phase = ret;

	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)
{
	int ret;

	if (!clk)
		return 0;

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

	return ret;
}
EXPORT_SYMBOL_GPL(clk_get_phase);

static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
{
	/* Assume a default value of 50% */
	core->duty.num = 1;
	core->duty.den = 2;
}

static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);

static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
{
	struct clk_duty *duty = &core->duty;
	int ret = 0;

	if (!core->ops->get_duty_cycle)
		return clk_core_update_duty_cycle_parent_nolock(core);

	ret = core->ops->get_duty_cycle(core->hw, duty);
	if (ret)
		goto reset;

	/* Don't trust the clock provider too much */
	if (duty->den == 0 || duty->num > duty->den) {
		ret = -EINVAL;
		goto reset;
	}

	return 0;

reset:
	clk_core_reset_duty_cycle_nolock(core);
	return ret;
}

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

	if (core->parent &&
	    core->flags & CLK_DUTY_CYCLE_PARENT) {
		ret = clk_core_update_duty_cycle_nolock(core->parent);
		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
	} else {
		clk_core_reset_duty_cycle_nolock(core);
	}

	return ret;
}

static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
						 struct clk_duty *duty);

static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
					  struct clk_duty *duty)
{
	int ret;

	lockdep_assert_held(&prepare_lock);

	if (clk_core_rate_is_protected(core))
		return -EBUSY;

	trace_clk_set_duty_cycle(core, duty);

	if (!core->ops->set_duty_cycle)
		return clk_core_set_duty_cycle_parent_nolock(core, duty);

	ret = core->ops->set_duty_cycle(core->hw, duty);
	if (!ret)
		memcpy(&core->duty, duty, sizeof(*duty));

	trace_clk_set_duty_cycle_complete(core, duty);

	return ret;
}

static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
						 struct clk_duty *duty)
{
	int ret = 0;

	if (core->parent &&
	    core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
		ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
	}

	return ret;
}

/**
 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
 * @clk: clock signal source
 * @num: numerator of the duty cycle ratio to be applied
 * @den: denominator of the duty cycle ratio to be applied
 *
 * Apply the duty cycle ratio if the ratio is valid and the clock can
 * perform this operation
 *
 * Returns (0) on success, a negative errno otherwise.
 */
int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
{
	int ret;
	struct clk_duty duty;

	if (!clk)
		return 0;

	/* sanity check the ratio */
	if (den == 0 || num > den)
		return -EINVAL;

	duty.num = num;
	duty.den = den;

	clk_prepare_lock();

	if (clk->exclusive_count)
		clk_core_rate_unprotect(clk->core);

	ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);

	if (clk->exclusive_count)
		clk_core_rate_protect(clk->core);

	clk_prepare_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(clk_set_duty_cycle);

static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
					  unsigned int scale)
{
	struct clk_duty *duty = &core->duty;
	int ret;

	clk_prepare_lock();

	ret = clk_core_update_duty_cycle_nolock(core);
	if (!ret)
		ret = mult_frac(scale, duty->num, duty->den);

	clk_prepare_unlock();

	return ret;
}

/**
 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
 * @clk: clock signal source
 * @scale: scaling factor to be applied to represent the ratio as an integer
 *
 * Returns the duty cycle ratio of a clock node multiplied by the provided
 * scaling factor, or negative errno on error.
 */
int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
{
	if (!clk)
		return 0;

	return clk_core_get_scaled_duty_cycle(clk->core, scale);
}
EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);

/**
 * 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 dereferencing 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 *orphan_list[] = {
	&clk_orphan_list,
	NULL,
};

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

	seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
		   level * 3 + 1, "",
		   30 - level * 3, c->name,
		   c->enable_count, c->prepare_count, c->protect_count,
		   clk_core_get_rate_recalc(c),
		   clk_core_get_accuracy_recalc(c));

	phase = clk_core_get_phase(c);
	if (phase >= 0)
		seq_printf(s, "%5d", phase);
	else
		seq_puts(s, "-----");

	seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));

	if (c->ops->is_enabled)
		seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
	else if (!c->ops->enable)
		seq_printf(s, " %9c\n", 'Y');
	else
		seq_printf(s, " %9c\n", '?');
}

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

	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, "                                 enable  prepare  protect                                duty  hardware\n");
	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable\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;
}
DEFINE_SHOW_ATTRIBUTE(clk_summary);

static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
{
	int phase;
	unsigned long min_rate, max_rate;

	clk_core_get_boundaries(c, &min_rate, &max_rate);

	/* 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, "\"protect_count\": %d,", c->protect_count);
	seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
	seq_printf(s, "\"min_rate\": %lu,", min_rate);
	seq_printf(s, "\"max_rate\": %lu,", max_rate);
	seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
	phase = clk_core_get_phase(c);
	if (phase >= 0)
		seq_printf(s, "\"phase\": %d,", phase);
	seq_printf(s, "\"duty_cycle\": %u",
		   clk_core_get_scaled_duty_cycle(c, 100000));
}

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

	clk_dump_one(s, c, level);

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

	seq_putc(s, '}');
}

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

	seq_putc(s, '{');
	clk_prepare_lock();

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

	clk_prepare_unlock();

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

#undef CLOCK_ALLOW_WRITE_DEBUGFS
#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
/*
 * This can be dangerous, therefore don't provide any real compile time
 * configuration option for this feature.
 * People who want to use this will need to modify the source code directly.
 */
static int clk_rate_set(void *data, u64 val)
{
	struct clk_core *core = data;
	int ret;

	clk_prepare_lock();
	ret = clk_core_set_rate_nolock(core, val);
	clk_prepare_unlock();

	return ret;
}

#define clk_rate_mode	0644

static int clk_prepare_enable_set(void *data, u64 val)
{
	struct clk_core *core = data;
	int ret = 0;

	if (val)
		ret = clk_prepare_enable(core->hw->clk);
	else
		clk_disable_unprepare(core->hw->clk);

	return ret;
}

static int clk_prepare_enable_get(void *data, u64 *val)
{
	struct clk_core *core = data;

	*val = core->enable_count && core->prepare_count;
	return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
			 clk_prepare_enable_set, "%llu\n");

#else
#define clk_rate_set	NULL
#define clk_rate_mode	0444
#endif

static int clk_rate_get(void *data, u64 *val)
{
	struct clk_core *core = data;

	*val = core->rate;
	return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");

static const struct {
	unsigned long flag;
	const char *name;
} clk_flags[] = {
#define ENTRY(f) { f, #f }
	ENTRY(CLK_SET_RATE_GATE),
	ENTRY(CLK_SET_PARENT_GATE),
	ENTRY(CLK_SET_RATE_PARENT),
	ENTRY(CLK_IGNORE_UNUSED),
	ENTRY(CLK_GET_RATE_NOCACHE),
	ENTRY(CLK_SET_RATE_NO_REPARENT),
	ENTRY(CLK_GET_ACCURACY_NOCACHE),
	ENTRY(CLK_RECALC_NEW_RATES),
	ENTRY(CLK_SET_RATE_UNGATE),
	ENTRY(CLK_IS_CRITICAL),
	ENTRY(CLK_OPS_PARENT_ENABLE),
	ENTRY(CLK_DUTY_CYCLE_PARENT),
#undef ENTRY
};

static int clk_flags_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;
	unsigned long flags = core->flags;
	unsigned int i;

	for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
		if (flags & clk_flags[i].flag) {
			seq_printf(s, "%s\n", clk_flags[i].name);
			flags &= ~clk_flags[i].flag;
		}
	}
	if (flags) {
		/* Unknown flags */
		seq_printf(s, "0x%lx\n", flags);
	}

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_flags);

static void possible_parent_show(struct seq_file *s, struct clk_core *core,
				 unsigned int i, char terminator)
{
	struct clk_core *parent;

	/*
	 * Go through the following options to fetch a parent's name.
	 *
	 * 1. Fetch the registered parent clock and use its name
	 * 2. Use the global (fallback) name if specified
	 * 3. Use the local fw_name if provided
	 * 4. Fetch parent clock's clock-output-name if DT index was set
	 *
	 * This may still fail in some cases, such as when the parent is
	 * specified directly via a struct clk_hw pointer, but it isn't
	 * registered (yet).
	 */
	parent = clk_core_get_parent_by_index(core, i);
	if (parent)
		seq_puts(s, parent->name);
	else if (core->parents[i].name)
		seq_puts(s, core->parents[i].name);
	else if (core->parents[i].fw_name)
		seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
	else if (core->parents[i].index >= 0)
		seq_puts(s,
			 of_clk_get_parent_name(core->of_node,
						core->parents[i].index));
	else
		seq_puts(s, "(missing)");

	seq_putc(s, terminator);
}

static int possible_parents_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;
	int i;

	for (i = 0; i < core->num_parents - 1; i++)
		possible_parent_show(s, core, i, ' ');

	possible_parent_show(s, core, i, '\n');

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(possible_parents);

static int current_parent_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;

	if (core->parent)
		seq_printf(s, "%s\n", core->parent->name);

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(current_parent);

static int clk_duty_cycle_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;
	struct clk_duty *duty = &core->duty;

	seq_printf(s, "%u/%u\n", duty->num, duty->den);

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);

static int clk_min_rate_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;
	unsigned long min_rate, max_rate;

	clk_prepare_lock();
	clk_core_get_boundaries(core, &min_rate, &max_rate);
	clk_prepare_unlock();
	seq_printf(s, "%lu\n", min_rate);

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_min_rate);

static int clk_max_rate_show(struct seq_file *s, void *data)
{
	struct clk_core *core = s->private;
	unsigned long min_rate, max_rate;

	clk_prepare_lock();
	clk_core_get_boundaries(core, &min_rate, &max_rate);
	clk_prepare_unlock();
	seq_printf(s, "%lu\n", max_rate);

	return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_max_rate);

static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
{
	struct dentry *root;

	if (!core || !pdentry)
		return;

	root = debugfs_create_dir(core->name, pdentry);
	core->dentry = root;

	debugfs_create_file("clk_rate", clk_rate_mode, root, core,
			    &clk_rate_fops);
	debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
	debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
	debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
	debugfs_create_u32("clk_phase", 0444, root, &core->phase);
	debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
	debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
	debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
	debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
	debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
	debugfs_create_file("clk_duty_cycle", 0444, root, core,
			    &clk_duty_cycle_fops);
#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
	debugfs_create_file("clk_prepare_enable", 0644, root, core,
			    &clk_prepare_enable_fops);
#endif

	if (core->num_parents > 0)
		debugfs_create_file("clk_parent", 0444, root, core,
				    &current_parent_fops);

	if (core->num_parents > 1)
		debugfs_create_file("clk_possible_parents", 0444, root, core,
				    &possible_parents_fops);

	if (core->ops->debug_init)
		core->ops->debug_init(core->hw, core->dentry);
}

/**
 * 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 void clk_debug_register(struct clk_core *core)
{
	mutex_lock(&clk_debug_lock);
	hlist_add_head(&core->debug_node, &clk_debug_list);
	if (inited)
		clk_debug_create_one(core, rootdir);
	mutex_unlock(&clk_debug_lock);
}

 /**
 * 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_core_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);
}

/**
 * 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;

	rootdir = debugfs_create_dir("clk", NULL);

	debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
			    &clk_summary_fops);
	debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
			    &clk_dump_fops);
	debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
			    &clk_summary_fops);
	debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
			    &clk_dump_fops);

	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 void clk_debug_register(struct clk_core *core) { }
static inline void clk_debug_unregister(struct clk_core *core)
{
}
#endif

static void clk_core_reparent_orphans_nolock(void)
{
	struct clk_core *orphan;
	struct hlist_node *tmp2;

	/*
	 * walk the list of orphan clocks and reparent any that newly finds a
	 * parent.
	 */
	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
		struct clk_core *parent = __clk_init_parent(orphan);

		/*
		 * We need to use __clk_set_parent_before() and _after() to
		 * to properly migrate any prepare/enable count of the orphan
		 * clock. This is important for CLK_IS_CRITICAL clocks, which
		 * are enabled during init but might not have a parent yet.
		 */
		if (parent) {
			/* update the clk tree topology */
			__clk_set_parent_before(orphan, parent);
			__clk_set_parent_after(orphan, parent, NULL);
			__clk_recalc_accuracies(orphan);
			__clk_recalc_rates(orphan, 0);
		}
	}
}

/**
 * __clk_core_init - initialize the data structures in a struct clk_core
 * @core:	clk_core being initialized
 *
 * Initializes the lists in struct clk_core, queries the hardware for the
 * parent and rate and sets them both.
 */
static int __clk_core_init(struct clk_core *core)
{
	int ret;
	struct clk_core *parent;
	unsigned long rate;
	int phase;

	if (!core)
		return -EINVAL;

	clk_prepare_lock();

	ret = clk_pm_runtime_get(core);
	if (ret)
		goto unlock;

	/* 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/driver-api/clk.rst */
	if (core->ops->set_rate &&
	    !((core->ops->round_rate || core->ops->determine_rate) &&
	      core->ops->recalc_rate)) {
		pr_err("%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_err("%s: %s must implement .get_parent & .set_parent\n",
		       __func__, core->name);
		ret = -EINVAL;
		goto out;
	}

	if (core->num_parents > 1 && !core->ops->get_parent) {
		pr_err("%s: %s must implement .get_parent as it has multi parents\n",
		       __func__, core->name);
		ret = -EINVAL;
		goto out;
	}

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

	/*
	 * 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 for
	 * CCF to get an accurate view of clock for any other callbacks. It may
	 * also be used needs to perform dynamic allocations. Such allocation
	 * must be freed in the terminate() callback.
	 * This callback shall not be used to initialize the parameters state,
	 * such as rate, parent, etc ...
	 *
	 * If it exist, this callback should called before any other callback of
	 * the clock
	 */
	if (core->ops->init) {
		ret = core->ops->init(core->hw);
		if (ret)
			goto out;
	}

	parent = core->parent = __clk_init_parent(core);

	/*
	 * Populate core->parent if parent has already been clk_core_init'd. If
	 * parent has not yet been clk_core_init'd then place clk in the orphan
	 * list.  If clk doesn't have any parents 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 (parent) {
		hlist_add_head(&core->child_node, &parent->children);
		core->orphan = parent->orphan;
	} else if (!core->num_parents) {
		hlist_add_head(&core->child_node, &clk_root_list);
		core->orphan = false;
	} else {
		hlist_add_head(&core->child_node, &clk_orphan_list);
		core->orphan = true;
	}

	/*
	 * 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_core_get_accuracy_no_lock(parent));
	else if (parent)
		core->accuracy = parent->accuracy;
	else
		core->accuracy = 0;

	/*
	 * Set clk's phase by clk_core_get_phase() caching the phase.
	 * Since a phase is by definition relative to its parent, just
	 * query the current clock phase, or just assume it's in phase.
	 */
	phase = clk_core_get_phase(core);
	if (phase < 0) {
		ret = phase;
		pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
			core->name);
		goto out;
	}

	/*
	 * Set clk's duty cycle.
	 */
	clk_core_update_duty_cycle_nolock(core);

	/*
	 * 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(parent));
	else if (parent)
		rate = parent->rate;
	else
		rate = 0;
	core->rate = core->req_rate = rate;

	/*
	 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
	 * don't get accidentally disabled when walking the orphan tree and
	 * reparenting clocks
	 */
	if (core->flags & CLK_IS_CRITICAL) {
		unsigned long flags;

		ret = clk_core_prepare(core);
		if (ret) {
			pr_warn("%s: critical clk '%s' failed to prepare\n",
			       __func__, core->name);
			goto out;
		}

		flags = clk_enable_lock();
		ret = clk_core_enable(core);
		clk_enable_unlock(flags);
		if (ret) {
			pr_warn("%s: critical clk '%s' failed to enable\n",
			       __func__, core->name);
			clk_core_unprepare(core);
			goto out;
		}
	}

	clk_core_reparent_orphans_nolock();


	kref_init(&core->ref);
out:
	clk_pm_runtime_put(core);
unlock:
	if (ret)
		hlist_del_init(&core->child_node);

	clk_prepare_unlock();

	if (!ret)
		clk_debug_register(core);

	return ret;
}

/**
 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
 * @core: clk to add consumer to
 * @clk: consumer to link to a clk
 */
static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
{
	clk_prepare_lock();
	hlist_add_head(&clk->clks_node, &core->clks);
	clk_prepare_unlock();
}

/**
 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
 * @clk: consumer to unlink
 */
static void clk_core_unlink_consumer(struct clk *clk)
{
	lockdep_assert_held(&prepare_lock);
	hlist_del(&clk->clks_node);
}

/**
 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
 * @core: clk to allocate a consumer for
 * @dev_id: string describing device name
 * @con_id: connection ID string on device
 *
 * Returns: clk consumer left unlinked from the consumer list
 */
static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
			     const char *con_id)
{
	struct clk *clk;

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

	clk->core = core;
	clk->dev_id = dev_id;
	clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
	clk->max_rate = ULONG_MAX;

	return clk;
}

/**
 * free_clk - Free a clk consumer
 * @clk: clk consumer to free
 *
 * Note, this assumes the clk has been unlinked from the clk_core consumer
 * list.
 */
static void free_clk(struct clk *clk)
{
	kfree_const(clk->con_id);
	kfree(clk);
}

/**
 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
 * a clk_hw
 * @dev: clk consumer device
 * @hw: clk_hw associated with the clk being consumed
 * @dev_id: string describing device name
 * @con_id: connection ID string on device
 *
 * This is the main function used to create a clk pointer for use by clk
 * consumers. It connects a consumer to the clk_core and clk_hw structures
 * used by the framework and clk provider respectively.
 */
struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
			      const char *dev_id, const char *con_id)
{
	struct clk *clk;
	struct clk_core *core;

	/* This is to allow this function to be chained to others */
	if (IS_ERR_OR_NULL(hw))
		return ERR_CAST(hw);

	core = hw->core;
	clk = alloc_clk(core, dev_id, con_id);
	if (IS_ERR(clk))
		return clk;
	clk->dev = dev;

	if (!try_module_get(core->owner)) {
		free_clk(clk);
		return ERR_PTR(-ENOENT);
	}

	kref_get(&core->ref);
	clk_core_link_consumer(core, clk);

	return clk;
}

/**
 * clk_hw_get_clk - get clk consumer given an clk_hw
 * @hw: clk_hw associated with the clk being consumed
 * @con_id: connection ID string on device
 *
 * Returns: new clk consumer
 * This is the function to be used by providers which need
 * to get a consumer clk and act on the clock element
 * Calls to this function must be balanced with calls clk_put()
 */
struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
{
	struct device *dev = hw->core->dev;

	return clk_hw_create_clk(dev, hw, dev_name(dev), con_id);
}
EXPORT_SYMBOL(clk_hw_get_clk);

static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
{
	const char *dst;

	if (!src) {
		if (must_exist)
			return -EINVAL;
		return 0;
	}

	*dst_p = dst = kstrdup_const(src, GFP_KERNEL);
	if (!dst)
		return -ENOMEM;

	return 0;
}

static int clk_core_populate_parent_map(struct clk_core *core,
					const struct clk_init_data *init)
{
	u8 num_parents = init->num_parents;
	const char * const *parent_names = init->parent_names;
	const struct clk_hw **parent_hws = init->parent_hws;
	const struct clk_parent_data *parent_data = init->parent_data;
	int i, ret = 0;
	struct clk_parent_map *parents, *parent;

	if (!num_parents)
		return 0;

	/*
	 * Avoid unnecessary string look-ups of clk_core's possible parents by
	 * having a cache of names/clk_hw pointers to clk_core pointers.
	 */
	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
	core->parents = parents;
	if (!parents)
		return -ENOMEM;

	/* Copy everything over because it might be __initdata */
	for (i = 0, parent = parents; i < num_parents; i++, parent++) {
		parent->index = -1;
		if (parent_names) {
			/* throw a WARN if any entries are NULL */
			WARN(!parent_names[i],
				"%s: invalid NULL in %s's .parent_names\n",
				__func__, core->name);
			ret = clk_cpy_name(&parent->name, parent_names[i],
					   true);
		} else if (parent_data) {
			parent->hw = parent_data[i].hw;
			parent->index = parent_data[i].index;
			ret = clk_cpy_name(&parent->fw_name,
					   parent_data[i].fw_name, false);
			if (!ret)
				ret = clk_cpy_name(&parent->name,
						   parent_data[i].name,
						   false);
		} else if (parent_hws) {
			parent->hw = parent_hws[i];
		} else {
			ret = -EINVAL;
			WARN(1, "Must specify parents if num_parents > 0\n");
		}

		if (ret) {
			do {
				kfree_const(parents[i].name);
				kfree_const(parents[i].fw_name);
			} while (--i >= 0);
			kfree(parents);

			return ret;
		}
	}

	return 0;
}

static void clk_core_free_parent_map(struct clk_core *core)
{
	int i = core->num_parents;

	if (!core->num_parents)
		return;

	while (--i >= 0) {
		kfree_const(core->parents[i].name);
		kfree_const(core->parents[i].fw_name);
	}

	kfree(core->parents);
}

static struct clk *
__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
{
	int ret;
	struct clk_core *core;
	const struct clk_init_data *init = hw->init;

	/*
	 * The init data is not supposed to be used outside of registration path.
	 * Set it to NULL so that provider drivers can't use it either and so that
	 * we catch use of hw->init early on in the core.
	 */
	hw->init = NULL;

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

	core->name = kstrdup_const(init->name, GFP_KERNEL);
	if (!core->name) {
		ret = -ENOMEM;
		goto fail_name;
	}

	if (WARN_ON(!init->ops)) {
		ret = -EINVAL;
		goto fail_ops;
	}
	core->ops = init->ops;

	if (dev && pm_runtime_enabled(dev))
		core->rpm_enabled = true;
	core->dev = dev;
	core->of_node = np;
	if (dev && dev->driver)
		core->owner = dev->driver->owner;
	core->hw = hw;
	core->flags = init->flags;
	core->num_parents = init->num_parents;
	core->min_rate = 0;
	core->max_rate = ULONG_MAX;
	hw->core = core;

	ret = clk_core_populate_parent_map(core, init);
	if (ret)
		goto fail_parents;

	INIT_HLIST_HEAD(&core->clks);

	/*
	 * Don't call clk_hw_create_clk() here because that would pin the
	 * provider module to itself and prevent it from ever being removed.
	 */
	hw->clk = alloc_clk(core, NULL, NULL);
	if (IS_ERR(hw->clk)) {
		ret = PTR_ERR(hw->clk);
		goto fail_create_clk;
	}

	clk_core_link_consumer(hw->core, hw->clk);

	ret = __clk_core_init(core);
	if (!ret)
		return hw->clk;

	clk_prepare_lock();
	clk_core_unlink_consumer(hw->clk);
	clk_prepare_unlock();

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

fail_create_clk:
	clk_core_free_parent_map(core);
fail_parents:
fail_ops:
	kfree_const(core->name);
fail_name:
	kfree(core);
fail_out:
	return ERR_PTR(ret);
}

/**
 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
 * @dev: Device to get device node of
 *
 * Return: device node pointer of @dev, or the device node pointer of
 * @dev->parent if dev doesn't have a device node, or NULL if neither
 * @dev or @dev->parent have a device node.
 */
static struct device_node *dev_or_parent_of_node(struct device *dev)
{
	struct device_node *np;

	if (!dev)
		return NULL;

	np = dev_of_node(dev);
	if (!np)
		np = dev_of_node(dev->parent);

	return np;
}

/**
 * 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 *deprecated* interface for populating the clock tree with
 * new clock nodes. Use clk_hw_register() instead.
 *
 * 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)
{
	return __clk_register(dev, dev_or_parent_of_node(dev), hw);
}
EXPORT_SYMBOL_GPL(clk_register);

/**
 * clk_hw_register - register a clk_hw and return an error code
 * @dev: device that is registering this clock
 * @hw: link to hardware-specific clock data
 *
 * clk_hw_register is the primary interface for populating the clock tree with
 * new clock nodes. It returns an integer equal to zero indicating success or
 * less than zero indicating failure. Drivers must test for an error code after
 * calling clk_hw_register().
 */
int clk_hw_register(struct device *dev, struct clk_hw *hw)
{
	return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
			       hw));
}
EXPORT_SYMBOL_GPL(clk_hw_register);

/*
 * of_clk_hw_register - register a clk_hw and return an error code
 * @node: device_node of device that is registering this clock
 * @hw: link to hardware-specific clock data
 *
 * of_clk_hw_register() is the primary interface for populating the clock tree
 * with new clock nodes when a struct device is not available, but a struct
 * device_node is. It returns an integer equal to zero indicating success or
 * less than zero indicating failure. Drivers must test for an error code after
 * calling of_clk_hw_register().
 */
int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
{
	return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
}
EXPORT_SYMBOL_GPL(of_clk_hw_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);

	lockdep_assert_held(&prepare_lock);

	clk_core_free_parent_map(core);
	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,
};

static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
						struct clk_core *target)
{
	int i;
	struct clk_core *child;

	for (i = 0; i < root->num_parents; i++)
		if (root->parents[i].core == target)
			root->parents[i].core = NULL;

	hlist_for_each_entry(child, &root->children, child_node)
		clk_core_evict_parent_cache_subtree(child, target);
}

/* Remove this clk from all parent caches */
static void clk_core_evict_parent_cache(struct clk_core *core)
{
	struct hlist_head **lists;
	struct clk_core *root;

	lockdep_assert_held(&prepare_lock);

	for (lists = all_lists; *lists; lists++)
		hlist_for_each_entry(root, *lists, child_node)
			clk_core_evict_parent_cache_subtree(root, core);

}

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

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

	clk_debug_unregister(clk->core);

	clk_prepare_lock();

	ops = clk->core->ops;
	if (ops == &clk_nodrv_ops) {
		pr_err("%s: unregistered clock: %s\n", __func__,
		       clk->core->name);
		goto unlock;
	}
	/*
	 * 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 (ops->terminate)
		ops->terminate(clk->core->hw);

	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_nolock(child, NULL);
	}

	clk_core_evict_parent_cache(clk->core);

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

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

	if (clk->core->protect_count)
		pr_warn("%s: unregistering protected clock: %s\n",
					__func__, clk->core->name);

	kref_put(&clk->core->ref, __clk_release);
	free_clk(clk);
unlock:
	clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unregister);

/**
 * clk_hw_unregister - unregister a currently registered clk_hw
 * @hw: hardware-specific clock data to unregister
 */
void clk_hw_unregister(struct clk_hw *hw)
{
	clk_unregister(hw->clk);
}
EXPORT_SYMBOL_GPL(clk_hw_unregister);

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

static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
{
	clk_hw_unregister(*(struct clk_hw **)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(). This function is *deprecated*, use devm_clk_hw_register() instead.
 *
 * 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_unregister_cb, 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);

/**
 * devm_clk_hw_register - resource managed clk_hw_register()
 * @dev: device that is registering this clock
 * @hw: link to hardware-specific clock data
 *
 * Managed clk_hw_register(). Clocks registered by this function are
 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
 * for more information.
 */
int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
{
	struct clk_hw **hwp;
	int ret;

	hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
	if (!hwp)
		return -ENOMEM;

	ret = clk_hw_register(dev, hw);
	if (!ret) {
		*hwp = hw;
		devres_add(dev, hwp);
	} else {
		devres_free(hwp);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(devm_clk_hw_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;
}

static int devm_clk_hw_match(struct device *dev, void *res, void *data)
{
	struct clk_hw *hw = res;

	if (WARN_ON(!hw))
		return 0;
	return hw == data;
}

/**
 * devm_clk_unregister - resource managed clk_unregister()
 * @dev: device that is unregistering the clock data
 * @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_unregister_cb, devm_clk_match, clk));
}
EXPORT_SYMBOL_GPL(devm_clk_unregister);

/**
 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
 * @dev: device that is unregistering the hardware-specific clock data
 * @hw: link to hardware-specific clock data
 *
 * Unregister a clk_hw registered with devm_clk_hw_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_hw_unregister(struct device *dev, struct clk_hw *hw)
{
	WARN_ON(devres_release(dev, devm_clk_hw_unregister_cb, devm_clk_hw_match,
				hw));
}
EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);

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

/**
 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
 * @dev: device that is registering this clock
 * @hw: clk_hw associated with the clk being consumed
 * @con_id: connection ID string on device
 *
 * Managed clk_hw_get_clk(). Clocks got with this function are
 * automatically clk_put() on driver detach. See clk_put()
 * for more information.
 */
struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
				const char *con_id)
{
	struct clk *clk;
	struct clk **clkp;

	/* This should not happen because it would mean we have drivers
	 * passing around clk_hw pointers instead of having the caller use
	 * proper clk_get() style APIs
	 */
	WARN_ON_ONCE(dev != hw->core->dev);

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

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

	return clk;
}
EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);

/*
 * clkdev helpers
 */

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

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

	clk_prepare_lock();

	/*
	 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
	 * given user should be balanced with calls to clk_rate_exclusive_put()
	 * and by that same consumer
	 */
	if (WARN_ON(clk->exclusive_count)) {
		/* We voiced our concern, let's sanitize the situation */
		clk->core->protect_count -= (clk->exclusive_count - 1);
		clk_core_rate_unprotect(clk->core);
		clk->exclusive_count = 0;
	}

	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);

	free_clk(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 (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(*cn), 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);

struct clk_notifier_devres {
	struct clk *clk;
	struct notifier_block *nb;
};

static void devm_clk_notifier_release(struct device *dev, void *res)
{
	struct clk_notifier_devres *devres = res;

	clk_notifier_unregister(devres->clk, devres->nb);
}

int devm_clk_notifier_register(struct device *dev, struct clk *clk,
			       struct notifier_block *nb)
{
	struct clk_notifier_devres *devres;
	int ret;

	devres = devres_alloc(devm_clk_notifier_release,
			      sizeof(*devres), GFP_KERNEL);

	if (!devres)
		return -ENOMEM;

	ret = clk_notifier_register(clk, nb);
	if (!ret) {
		devres->clk = clk;
		devres->nb = nb;
	} else {
		devres_free(devres);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(devm_clk_notifier_register);

#ifdef CONFIG_OF
static void clk_core_reparent_orphans(void)
{
	clk_prepare_lock();
	clk_core_reparent_orphans_nolock();
	clk_prepare_unlock();
}

/**
 * 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
 * @get_hw: Get clk_hw callback.  Returns NULL, ERR_PTR or a
 *       struct clk_hw 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);
	struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
	void *data;
};

extern struct of_device_id __clk_of_table;
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_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
{
	return data;
}
EXPORT_SYMBOL_GPL(of_clk_hw_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 %u\n", __func__, idx);
		return ERR_PTR(-EINVAL);
	}

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

struct clk_hw *
of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
{
	struct clk_hw_onecell_data *hw_data = data;
	unsigned int idx = clkspec->args[0];

	if (idx >= hw_data->num) {
		pr_err("%s: invalid index %u\n", __func__, idx);
		return ERR_PTR(-EINVAL);
	}

	return hw_data->hws[idx];
}
EXPORT_SYMBOL_GPL(of_clk_hw_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.
 *
 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
 */
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(*cp), 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 %pOF\n", np);

	clk_core_reparent_orphans();

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

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

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

	mutex_lock(&of_clk_mutex);
	list_add(&cp->link, &of_clk_providers);
	mutex_unlock(&of_clk_mutex);
	pr_debug("Added clk_hw provider from %pOF\n", np);

	clk_core_reparent_orphans();

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

	return ret;
}
EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);

static void devm_of_clk_release_provider(struct device *dev, void *res)
{
	of_clk_del_provider(*(struct device_node **)res);
}

/*
 * We allow a child device to use its parent device as the clock provider node
 * for cases like MFD sub-devices where the child device driver wants to use
 * devm_*() APIs but not list the device in DT as a sub-node.
 */
static struct device_node *get_clk_provider_node(struct device *dev)
{
	struct device_node *np, *parent_np;

	np = dev->of_node;
	parent_np = dev->parent ? dev->parent->of_node : NULL;

	if (!of_find_property(np, "#clock-cells", NULL))
		if (of_find_property(parent_np, "#clock-cells", NULL))
			np = parent_np;

	return np;
}

/**
 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
 * @dev: Device acting as the clock provider (used for DT node and lifetime)
 * @get: callback for decoding clk_hw
 * @data: context pointer for @get callback
 *
 * Registers clock provider for given device's node. If the device has no DT
 * node or if the device node lacks of clock provider information (#clock-cells)
 * then the parent device's node is scanned for this information. If parent node
 * has the #clock-cells then it is used in registration. Provider is
 * automatically released at device exit.
 *
 * Return: 0 on success or an errno on failure.
 */
int devm_of_clk_add_hw_provider(struct device *dev,
			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
					      void *data),
			void *data)
{
	struct device_node **ptr, *np;
	int ret;

	ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
			   GFP_KERNEL);
	if (!ptr)
		return -ENOMEM;

	np = get_clk_provider_node(dev);
	ret = of_clk_add_hw_provider(np, get, data);
	if (!ret) {
		*ptr = np;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_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);

static int devm_clk_provider_match(struct device *dev, void *res, void *data)
{
	struct device_node **np = res;

	if (WARN_ON(!np || !*np))
		return 0;

	return *np == data;
}

/**
 * devm_of_clk_del_provider() - Remove clock provider registered using devm
 * @dev: Device to whose lifetime the clock provider was bound
 */
void devm_of_clk_del_provider(struct device *dev)
{
	int ret;
	struct device_node *np = get_clk_provider_node(dev);

	ret = devres_release(dev, devm_of_clk_release_provider,
			     devm_clk_provider_match, np);

	WARN_ON(ret);
}
EXPORT_SYMBOL(devm_of_clk_del_provider);

/**
 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
 * @np: device node to parse clock specifier from
 * @index: index of phandle to parse clock out of. If index < 0, @name is used
 * @name: clock name to find and parse. If name is NULL, the index is used
 * @out_args: Result of parsing the clock specifier
 *
 * Parses a device node's "clocks" and "clock-names" properties to find the
 * phandle and cells for the index or name that is desired. The resulting clock
 * specifier is placed into @out_args, or an errno is returned when there's a
 * parsing error. The @index argument is ignored if @name is non-NULL.
 *
 * Example:
 *
 * phandle1: clock-controller@1 {
 *	#clock-cells = <2>;
 * }
 *
 * phandle2: clock-controller@2 {
 *	#clock-cells = <1>;
 * }
 *
 * clock-consumer@3 {
 *	clocks = <&phandle1 1 2 &phandle2 3>;
 *	clock-names = "name1", "name2";
 * }
 *
 * To get a device_node for `clock-controller@2' node you may call this
 * function a few different ways:
 *
 *   of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
 *   of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
 *   of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
 *
 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
 * the "clock-names" property of @np.
 */
static int of_parse_clkspec(const struct device_node *np, int index,
			    const char *name, struct of_phandle_args *out_args)
{
	int ret = -ENOENT;

	/* Walk up the tree of devices looking for a clock property that matches */
	while (np) {
		/*
		 * For named clocks, first look up the name in the
		 * "clock-names" property.  If it cannot be found, then index
		 * will be an error code and of_parse_phandle_with_args() will
		 * return -EINVAL.
		 */
		if (name)
			index = of_property_match_string(np, "clock-names", name);
		ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
						 index, out_args);
		if (!ret)
			break;
		if (name && index >= 0)
			break;

		/*
		 * No matching clock found on this node.  If the parent node
		 * has a "clock-ranges" property, then we can try one of its
		 * clocks.
		 */
		np = np->parent;
		if (np && !of_get_property(np, "clock-ranges", NULL))
			break;
		index = 0;
	}

	return ret;
}

static struct clk_hw *
__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
			      struct of_phandle_args *clkspec)
{
	struct clk *clk;

	if (provider->get_hw)
		return provider->get_hw(clkspec, provider->data);

	clk = provider->get(clkspec, provider->data);
	if (IS_ERR(clk))
		return ERR_CAST(clk);
	return __clk_get_hw(clk);
}

static struct clk_hw *
of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
{
	struct of_clk_provider *provider;
	struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);

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

	mutex_lock(&of_clk_mutex);
	list_for_each_entry(provider, &of_clk_providers, link) {
		if (provider->node == clkspec->np) {
			hw = __of_clk_get_hw_from_provider(provider, clkspec);
			if (!IS_ERR(hw))
				break;
		}
	}
	mutex_unlock(&of_clk_mutex);

	return hw;
}

/**
 * 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)
{
	struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);

	return clk_hw_create_clk(NULL, hw, NULL, __func__);
}
EXPORT_SYMBOL_GPL(of_clk_get_from_provider);

struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
			     const char *con_id)
{
	int ret;
	struct clk_hw *hw;
	struct of_phandle_args clkspec;

	ret = of_parse_clkspec(np, index, con_id, &clkspec);
	if (ret)
		return ERR_PTR(ret);

	hw = of_clk_get_hw_from_clkspec(&clkspec);
	of_node_put(clkspec.np);

	return hw;
}

static struct clk *__of_clk_get(struct device_node *np,
				int index, const char *dev_id,
				const char *con_id)
{
	struct clk_hw *hw = of_clk_get_hw(np, index, con_id);

	return clk_hw_create_clk(NULL, hw, dev_id, con_id);
}

struct clk *of_clk_get(struct device_node *np, int index)
{
	return __of_clk_get(np, index, np->full_name, NULL);
}
EXPORT_SYMBOL(of_clk_get);

/**
 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
 * @np: pointer to clock consumer node
 * @name: name of consumer's clock input, or NULL for the first clock reference
 *
 * This function parses the clocks and clock-names properties,
 * and uses them to look up the struct clk from the registered list of clock
 * providers.
 */
struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
{
	if (!np)
		return ERR_PTR(-ENOENT);

	return __of_clk_get(np, 0, np->full_name, name);
}
EXPORT_SYMBOL(of_clk_get_by_name);

/**
 * of_clk_get_parent_count() - Count the number of clocks a device node has
 * @np: device node to count
 *
 * Returns: The number of clocks that are possible parents of this node
 */
unsigned int of_clk_get_parent_count(const struct device_node *np)
{
	int count;

	count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
	if (count < 0)
		return 0;

	return count;
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_count);

const char *of_clk_get_parent_name(const 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;
	struct clk *clk;

	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++;
	}
	/* We went off the end of 'clock-indices' without finding it */
	if (prop && !vp)
		return NULL;

	if (of_property_read_string_index(clkspec.np, "clock-output-names",
					  index,
					  &clk_name) < 0) {
		/*
		 * Best effort to get the name if the clock has been
		 * registered with the framework. If the clock isn't
		 * registered, we return the node name as the name of
		 * the clock as long as #clock-cells = 0.
		 */
		clk = of_clk_get_from_provider(&clkspec);
		if (IS_ERR(clk)) {
			if (clkspec.args_count == 0)
				clk_name = clkspec.np->name;
			else
				clk_name = NULL;
		} else {
			clk_name = __clk_get_name(clk);
			clk_put(clk);
		}
	}


	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 {
	void (*clk_init_cb)(struct device_node *);
	struct device_node *np;
	struct list_head node;
};

/*
 * 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_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
 * @np: Device node pointer associated with clock provider
 * @index: clock index
 * @flags: pointer to top-level framework flags
 *
 * Detects if the clock-critical property exists and, if so, sets the
 * corresponding CLK_IS_CRITICAL flag.
 *
 * Do not use this function. It exists only for legacy Device Tree
 * bindings, such as the one-clock-per-node style that are outdated.
 * Those bindings typically put all clock data into .dts and the Linux
 * driver has no clock data, thus making it impossible to set this flag
 * correctly from the driver. Only those drivers may call
 * of_clk_detect_critical from their setup functions.
 *
 * Return: error code or zero on success
 */
int of_clk_detect_critical(struct device_node *np, int index,
			   unsigned long *flags)
{
	struct property *prop;
	const __be32 *cur;
	uint32_t idx;

	if (!np || !flags)
		return -EINVAL;

	of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
		if (index == idx)
			*flags |= CLK_IS_CRITICAL;

	return 0;
}

/**
 * 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;
	LIST_HEAD(clk_provider_list);

	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;

		if (!of_device_is_available(np))
			continue;

		parent = kzalloc(sizeof(*parent), GFP_KERNEL);
		if (!parent) {
			list_for_each_entry_safe(clk_provider, next,
						 &clk_provider_list, node) {
				list_del(&clk_provider->node);
				of_node_put(clk_provider->np);
				kfree(clk_provider);
			}
			of_node_put(np);
			return;
		}

		parent->clk_init_cb = match->data;
		parent->np = of_node_get(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)) {

				/* Don't populate platform devices */
				of_node_set_flag(clk_provider->np,
						 OF_POPULATED);

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

				list_del(&clk_provider->node);
				of_node_put(clk_provider->np);
				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