summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-pl022.c
blob: 81847c9a7586f4b9acc6edfc2f099e9abab9532f (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
/*
 * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
 *
 * Copyright (C) 2008-2009 ST-Ericsson AB
 * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
 *
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 *
 * Initial version inspired by:
 *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
 * Initial adoption to PL022 by:
 *      Sachin Verma <sachin.verma@st.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/pm_runtime.h>
#include <linux/sched.h>

/*
 * This macro is used to define some register default values.
 * reg is masked with mask, the OR:ed with an (again masked)
 * val shifted sb steps to the left.
 */
#define SSP_WRITE_BITS(reg, val, mask, sb) \
 ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))

/*
 * This macro is also used to define some default values.
 * It will just shift val by sb steps to the left and mask
 * the result with mask.
 */
#define GEN_MASK_BITS(val, mask, sb) \
 (((val)<<(sb)) & (mask))

#define DRIVE_TX		0
#define DO_NOT_DRIVE_TX		1

#define DO_NOT_QUEUE_DMA	0
#define QUEUE_DMA		1

#define RX_TRANSFER		1
#define TX_TRANSFER		2

/*
 * Macros to access SSP Registers with their offsets
 */
#define SSP_CR0(r)	(r + 0x000)
#define SSP_CR1(r)	(r + 0x004)
#define SSP_DR(r)	(r + 0x008)
#define SSP_SR(r)	(r + 0x00C)
#define SSP_CPSR(r)	(r + 0x010)
#define SSP_IMSC(r)	(r + 0x014)
#define SSP_RIS(r)	(r + 0x018)
#define SSP_MIS(r)	(r + 0x01C)
#define SSP_ICR(r)	(r + 0x020)
#define SSP_DMACR(r)	(r + 0x024)
#define SSP_ITCR(r)	(r + 0x080)
#define SSP_ITIP(r)	(r + 0x084)
#define SSP_ITOP(r)	(r + 0x088)
#define SSP_TDR(r)	(r + 0x08C)

#define SSP_PID0(r)	(r + 0xFE0)
#define SSP_PID1(r)	(r + 0xFE4)
#define SSP_PID2(r)	(r + 0xFE8)
#define SSP_PID3(r)	(r + 0xFEC)

#define SSP_CID0(r)	(r + 0xFF0)
#define SSP_CID1(r)	(r + 0xFF4)
#define SSP_CID2(r)	(r + 0xFF8)
#define SSP_CID3(r)	(r + 0xFFC)

/*
 * SSP Control Register 0  - SSP_CR0
 */
#define SSP_CR0_MASK_DSS	(0x0FUL << 0)
#define SSP_CR0_MASK_FRF	(0x3UL << 4)
#define SSP_CR0_MASK_SPO	(0x1UL << 6)
#define SSP_CR0_MASK_SPH	(0x1UL << 7)
#define SSP_CR0_MASK_SCR	(0xFFUL << 8)

/*
 * The ST version of this block moves som bits
 * in SSP_CR0 and extends it to 32 bits
 */
#define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
#define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
#define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
#define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)

/*
 * SSP Control Register 0  - SSP_CR1
 */
#define SSP_CR1_MASK_LBM	(0x1UL << 0)
#define SSP_CR1_MASK_SSE	(0x1UL << 1)
#define SSP_CR1_MASK_MS		(0x1UL << 2)
#define SSP_CR1_MASK_SOD	(0x1UL << 3)

/*
 * The ST version of this block adds some bits
 * in SSP_CR1
 */
#define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
#define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
#define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
/* This one is only in the PL023 variant */
#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)

/*
 * SSP Status Register - SSP_SR
 */
#define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
#define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
#define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
#define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
#define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */

/*
 * SSP Clock Prescale Register  - SSP_CPSR
 */
#define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)

/*
 * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
 */
#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
#define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
#define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
#define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */

/*
 * SSP Raw Interrupt Status Register - SSP_RIS
 */
/* Receive Overrun Raw Interrupt status */
#define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
/* Receive Timeout Raw Interrupt status */
#define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
/* Receive FIFO Raw Interrupt status */
#define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
/* Transmit FIFO Raw Interrupt status */
#define SSP_RIS_MASK_TXRIS		(0x1UL << 3)

/*
 * SSP Masked Interrupt Status Register - SSP_MIS
 */
/* Receive Overrun Masked Interrupt status */
#define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
/* Receive Timeout Masked Interrupt status */
#define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
/* Receive FIFO Masked Interrupt status */
#define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
/* Transmit FIFO Masked Interrupt status */
#define SSP_MIS_MASK_TXMIS		(0x1UL << 3)

/*
 * SSP Interrupt Clear Register - SSP_ICR
 */
/* Receive Overrun Raw Clear Interrupt bit */
#define SSP_ICR_MASK_RORIC		(0x1UL << 0)
/* Receive Timeout Clear Interrupt bit */
#define SSP_ICR_MASK_RTIC		(0x1UL << 1)

/*
 * SSP DMA Control Register - SSP_DMACR
 */
/* Receive DMA Enable bit */
#define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
/* Transmit DMA Enable bit */
#define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)

/*
 * SSP Integration Test control Register - SSP_ITCR
 */
#define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
#define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)

/*
 * SSP Integration Test Input Register - SSP_ITIP
 */
#define ITIP_MASK_SSPRXD		 (0x1UL << 0)
#define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
#define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
#define ITIP_MASK_RXDMAC		 (0x1UL << 3)
#define ITIP_MASK_TXDMAC		 (0x1UL << 4)
#define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)

/*
 * SSP Integration Test output Register - SSP_ITOP
 */
#define ITOP_MASK_SSPTXD		 (0x1UL << 0)
#define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
#define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
#define ITOP_MASK_SSPOEn		 (0x1UL << 3)
#define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
#define ITOP_MASK_RORINTR		 (0x1UL << 5)
#define ITOP_MASK_RTINTR		 (0x1UL << 6)
#define ITOP_MASK_RXINTR		 (0x1UL << 7)
#define ITOP_MASK_TXINTR		 (0x1UL << 8)
#define ITOP_MASK_INTR			 (0x1UL << 9)
#define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
#define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
#define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
#define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)

/*
 * SSP Test Data Register - SSP_TDR
 */
#define TDR_MASK_TESTDATA		(0xFFFFFFFF)

/*
 * Message State
 * we use the spi_message.state (void *) pointer to
 * hold a single state value, that's why all this
 * (void *) casting is done here.
 */
#define STATE_START			((void *) 0)
#define STATE_RUNNING			((void *) 1)
#define STATE_DONE			((void *) 2)
#define STATE_ERROR			((void *) -1)

/*
 * SSP State - Whether Enabled or Disabled
 */
#define SSP_DISABLED			(0)
#define SSP_ENABLED			(1)

/*
 * SSP DMA State - Whether DMA Enabled or Disabled
 */
#define SSP_DMA_DISABLED		(0)
#define SSP_DMA_ENABLED			(1)

/*
 * SSP Clock Defaults
 */
#define SSP_DEFAULT_CLKRATE 0x2
#define SSP_DEFAULT_PRESCALE 0x40

/*
 * SSP Clock Parameter ranges
 */
#define CPSDVR_MIN 0x02
#define CPSDVR_MAX 0xFE
#define SCR_MIN 0x00
#define SCR_MAX 0xFF

/*
 * SSP Interrupt related Macros
 */
#define DEFAULT_SSP_REG_IMSC  0x0UL
#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)

#define CLEAR_ALL_INTERRUPTS  0x3

#define SPI_POLLING_TIMEOUT 1000

/*
 * The type of reading going on on this chip
 */
enum ssp_reading {
	READING_NULL,
	READING_U8,
	READING_U16,
	READING_U32
};

/**
 * The type of writing going on on this chip
 */
enum ssp_writing {
	WRITING_NULL,
	WRITING_U8,
	WRITING_U16,
	WRITING_U32
};

/**
 * struct vendor_data - vendor-specific config parameters
 * for PL022 derivates
 * @fifodepth: depth of FIFOs (both)
 * @max_bpw: maximum number of bits per word
 * @unidir: supports unidirection transfers
 * @extended_cr: 32 bit wide control register 0 with extra
 * features and extra features in CR1 as found in the ST variants
 * @pl023: supports a subset of the ST extensions called "PL023"
 */
struct vendor_data {
	int fifodepth;
	int max_bpw;
	bool unidir;
	bool extended_cr;
	bool pl023;
	bool loopback;
};

/**
 * struct pl022 - This is the private SSP driver data structure
 * @adev: AMBA device model hookup
 * @vendor: vendor data for the IP block
 * @phybase: the physical memory where the SSP device resides
 * @virtbase: the virtual memory where the SSP is mapped
 * @clk: outgoing clock "SPICLK" for the SPI bus
 * @master: SPI framework hookup
 * @master_info: controller-specific data from machine setup
 * @kworker: thread struct for message pump
 * @kworker_task: pointer to task for message pump kworker thread
 * @pump_messages: work struct for scheduling work to the message pump
 * @queue_lock: spinlock to syncronise access to message queue
 * @queue: message queue
 * @busy: message pump is busy
 * @running: message pump is running
 * @pump_transfers: Tasklet used in Interrupt Transfer mode
 * @cur_msg: Pointer to current spi_message being processed
 * @cur_transfer: Pointer to current spi_transfer
 * @cur_chip: pointer to current clients chip(assigned from controller_state)
 * @next_msg_cs_active: the next message in the queue has been examined
 *  and it was found that it uses the same chip select as the previous
 *  message, so we left it active after the previous transfer, and it's
 *  active already.
 * @tx: current position in TX buffer to be read
 * @tx_end: end position in TX buffer to be read
 * @rx: current position in RX buffer to be written
 * @rx_end: end position in RX buffer to be written
 * @read: the type of read currently going on
 * @write: the type of write currently going on
 * @exp_fifo_level: expected FIFO level
 * @dma_rx_channel: optional channel for RX DMA
 * @dma_tx_channel: optional channel for TX DMA
 * @sgt_rx: scattertable for the RX transfer
 * @sgt_tx: scattertable for the TX transfer
 * @dummypage: a dummy page used for driving data on the bus with DMA
 */
struct pl022 {
	struct amba_device		*adev;
	struct vendor_data		*vendor;
	resource_size_t			phybase;
	void __iomem			*virtbase;
	struct clk			*clk;
	struct spi_master		*master;
	struct pl022_ssp_controller	*master_info;
	/* Driver message pump */
	struct kthread_worker		kworker;
	struct task_struct		*kworker_task;
	struct kthread_work		pump_messages;
	spinlock_t			queue_lock;
	struct list_head		queue;
	bool				busy;
	bool				running;
	/* Message transfer pump */
	struct tasklet_struct		pump_transfers;
	struct spi_message		*cur_msg;
	struct spi_transfer		*cur_transfer;
	struct chip_data		*cur_chip;
	bool				next_msg_cs_active;
	void				*tx;
	void				*tx_end;
	void				*rx;
	void				*rx_end;
	enum ssp_reading		read;
	enum ssp_writing		write;
	u32				exp_fifo_level;
	enum ssp_rx_level_trig		rx_lev_trig;
	enum ssp_tx_level_trig		tx_lev_trig;
	/* DMA settings */
#ifdef CONFIG_DMA_ENGINE
	struct dma_chan			*dma_rx_channel;
	struct dma_chan			*dma_tx_channel;
	struct sg_table			sgt_rx;
	struct sg_table			sgt_tx;
	char				*dummypage;
#endif
};

/**
 * struct chip_data - To maintain runtime state of SSP for each client chip
 * @cr0: Value of control register CR0 of SSP - on later ST variants this
 *       register is 32 bits wide rather than just 16
 * @cr1: Value of control register CR1 of SSP
 * @dmacr: Value of DMA control Register of SSP
 * @cpsr: Value of Clock prescale register
 * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
 * @enable_dma: Whether to enable DMA or not
 * @read: function ptr to be used to read when doing xfer for this chip
 * @write: function ptr to be used to write when doing xfer for this chip
 * @cs_control: chip select callback provided by chip
 * @xfer_type: polling/interrupt/DMA
 *
 * Runtime state of the SSP controller, maintained per chip,
 * This would be set according to the current message that would be served
 */
struct chip_data {
	u32 cr0;
	u16 cr1;
	u16 dmacr;
	u16 cpsr;
	u8 n_bytes;
	bool enable_dma;
	enum ssp_reading read;
	enum ssp_writing write;
	void (*cs_control) (u32 command);
	int xfer_type;
};

/**
 * null_cs_control - Dummy chip select function
 * @command: select/delect the chip
 *
 * If no chip select function is provided by client this is used as dummy
 * chip select
 */
static void null_cs_control(u32 command)
{
	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
}

/**
 * giveback - current spi_message is over, schedule next message and call
 * callback of this message. Assumes that caller already
 * set message->status; dma and pio irqs are blocked
 * @pl022: SSP driver private data structure
 */
static void giveback(struct pl022 *pl022)
{
	struct spi_transfer *last_transfer;
	unsigned long flags;
	struct spi_message *msg;
	pl022->next_msg_cs_active = false;

	last_transfer = list_entry(pl022->cur_msg->transfers.prev,
					struct spi_transfer,
					transfer_list);

	/* Delay if requested before any change in chip select */
	if (last_transfer->delay_usecs)
		/*
		 * FIXME: This runs in interrupt context.
		 * Is this really smart?
		 */
		udelay(last_transfer->delay_usecs);

	if (!last_transfer->cs_change) {
		struct spi_message *next_msg;

		/*
		 * cs_change was not set. We can keep the chip select
		 * enabled if there is message in the queue and it is
		 * for the same spi device.
		 *
		 * We cannot postpone this until pump_messages, because
		 * after calling msg->complete (below) the driver that
		 * sent the current message could be unloaded, which
		 * could invalidate the cs_control() callback...
		 */

		/* get a pointer to the next message, if any */
		spin_lock_irqsave(&pl022->queue_lock, flags);
		if (list_empty(&pl022->queue))
			next_msg = NULL;
		else
			next_msg = list_entry(pl022->queue.next,
					struct spi_message, queue);
		spin_unlock_irqrestore(&pl022->queue_lock, flags);

		/*
		 * see if the next and current messages point
		 * to the same spi device.
		 */
		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
			next_msg = NULL;
		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
			pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
		else
			pl022->next_msg_cs_active = true;
	}

	spin_lock_irqsave(&pl022->queue_lock, flags);
	msg = pl022->cur_msg;
	pl022->cur_msg = NULL;
	pl022->cur_transfer = NULL;
	pl022->cur_chip = NULL;
	queue_kthread_work(&pl022->kworker, &pl022->pump_messages);
	spin_unlock_irqrestore(&pl022->queue_lock, flags);

	msg->state = NULL;
	if (msg->complete)
		msg->complete(msg->context);
}

/**
 * flush - flush the FIFO to reach a clean state
 * @pl022: SSP driver private data structure
 */
static int flush(struct pl022 *pl022)
{
	unsigned long limit = loops_per_jiffy << 1;

	dev_dbg(&pl022->adev->dev, "flush\n");
	do {
		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
			readw(SSP_DR(pl022->virtbase));
	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);

	pl022->exp_fifo_level = 0;

	return limit;
}

/**
 * restore_state - Load configuration of current chip
 * @pl022: SSP driver private data structure
 */
static void restore_state(struct pl022 *pl022)
{
	struct chip_data *chip = pl022->cur_chip;

	if (pl022->vendor->extended_cr)
		writel(chip->cr0, SSP_CR0(pl022->virtbase));
	else
		writew(chip->cr0, SSP_CR0(pl022->virtbase));
	writew(chip->cr1, SSP_CR1(pl022->virtbase));
	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}

/*
 * Default SSP Register Values
 */
#define DEFAULT_SSP_REG_CR0 ( \
	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)

/* ST versions have slightly different bit layout */
#define DEFAULT_SSP_REG_CR0_ST ( \
	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
)

/* The PL023 version is slightly different again */
#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)

#define DEFAULT_SSP_REG_CR1 ( \
	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
)

/* ST versions extend this register to use all 16 bits */
#define DEFAULT_SSP_REG_CR1_ST ( \
	DEFAULT_SSP_REG_CR1 | \
	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
)

/*
 * The PL023 variant has further differences: no loopback mode, no microwire
 * support, and a new clock feedback delay setting.
 */
#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
)

#define DEFAULT_SSP_REG_CPSR ( \
	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
)

#define DEFAULT_SSP_REG_DMACR (\
	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
)

/**
 * load_ssp_default_config - Load default configuration for SSP
 * @pl022: SSP driver private data structure
 */
static void load_ssp_default_config(struct pl022 *pl022)
{
	if (pl022->vendor->pl023) {
		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
	} else if (pl022->vendor->extended_cr) {
		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
	} else {
		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
	}
	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}

/**
 * This will write to TX and read from RX according to the parameters
 * set in pl022.
 */
static void readwriter(struct pl022 *pl022)
{

	/*
	 * The FIFO depth is different between primecell variants.
	 * I believe filling in too much in the FIFO might cause
	 * errons in 8bit wide transfers on ARM variants (just 8 words
	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
	 *
	 * To prevent this issue, the TX FIFO is only filled to the
	 * unused RX FIFO fill length, regardless of what the TX
	 * FIFO status flag indicates.
	 */
	dev_dbg(&pl022->adev->dev,
		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);

	/* Read as much as you can */
	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
	       && (pl022->rx < pl022->rx_end)) {
		switch (pl022->read) {
		case READING_NULL:
			readw(SSP_DR(pl022->virtbase));
			break;
		case READING_U8:
			*(u8 *) (pl022->rx) =
				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
			break;
		case READING_U16:
			*(u16 *) (pl022->rx) =
				(u16) readw(SSP_DR(pl022->virtbase));
			break;
		case READING_U32:
			*(u32 *) (pl022->rx) =
				readl(SSP_DR(pl022->virtbase));
			break;
		}
		pl022->rx += (pl022->cur_chip->n_bytes);
		pl022->exp_fifo_level--;
	}
	/*
	 * Write as much as possible up to the RX FIFO size
	 */
	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
	       && (pl022->tx < pl022->tx_end)) {
		switch (pl022->write) {
		case WRITING_NULL:
			writew(0x0, SSP_DR(pl022->virtbase));
			break;
		case WRITING_U8:
			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
			break;
		case WRITING_U16:
			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
			break;
		case WRITING_U32:
			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
			break;
		}
		pl022->tx += (pl022->cur_chip->n_bytes);
		pl022->exp_fifo_level++;
		/*
		 * This inner reader takes care of things appearing in the RX
		 * FIFO as we're transmitting. This will happen a lot since the
		 * clock starts running when you put things into the TX FIFO,
		 * and then things are continuously clocked into the RX FIFO.
		 */
		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
		       && (pl022->rx < pl022->rx_end)) {
			switch (pl022->read) {
			case READING_NULL:
				readw(SSP_DR(pl022->virtbase));
				break;
			case READING_U8:
				*(u8 *) (pl022->rx) =
					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
				break;
			case READING_U16:
				*(u16 *) (pl022->rx) =
					(u16) readw(SSP_DR(pl022->virtbase));
				break;
			case READING_U32:
				*(u32 *) (pl022->rx) =
					readl(SSP_DR(pl022->virtbase));
				break;
			}
			pl022->rx += (pl022->cur_chip->n_bytes);
			pl022->exp_fifo_level--;
		}
	}
	/*
	 * When we exit here the TX FIFO should be full and the RX FIFO
	 * should be empty
	 */
}

/**
 * next_transfer - Move to the Next transfer in the current spi message
 * @pl022: SSP driver private data structure
 *
 * This function moves though the linked list of spi transfers in the
 * current spi message and returns with the state of current spi
 * message i.e whether its last transfer is done(STATE_DONE) or
 * Next transfer is ready(STATE_RUNNING)
 */
static void *next_transfer(struct pl022 *pl022)
{
	struct spi_message *msg = pl022->cur_msg;
	struct spi_transfer *trans = pl022->cur_transfer;

	/* Move to next transfer */
	if (trans->transfer_list.next != &msg->transfers) {
		pl022->cur_transfer =
		    list_entry(trans->transfer_list.next,
			       struct spi_transfer, transfer_list);
		return STATE_RUNNING;
	}
	return STATE_DONE;
}

/*
 * This DMA functionality is only compiled in if we have
 * access to the generic DMA devices/DMA engine.
 */
#ifdef CONFIG_DMA_ENGINE
static void unmap_free_dma_scatter(struct pl022 *pl022)
{
	/* Unmap and free the SG tables */
	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
	sg_free_table(&pl022->sgt_rx);
	sg_free_table(&pl022->sgt_tx);
}

static void dma_callback(void *data)
{
	struct pl022 *pl022 = data;
	struct spi_message *msg = pl022->cur_msg;

	BUG_ON(!pl022->sgt_rx.sgl);

#ifdef VERBOSE_DEBUG
	/*
	 * Optionally dump out buffers to inspect contents, this is
	 * good if you want to convince yourself that the loopback
	 * read/write contents are the same, when adopting to a new
	 * DMA engine.
	 */
	{
		struct scatterlist *sg;
		unsigned int i;

		dma_sync_sg_for_cpu(&pl022->adev->dev,
				    pl022->sgt_rx.sgl,
				    pl022->sgt_rx.nents,
				    DMA_FROM_DEVICE);

		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
			print_hex_dump(KERN_ERR, "SPI RX: ",
				       DUMP_PREFIX_OFFSET,
				       16,
				       1,
				       sg_virt(sg),
				       sg_dma_len(sg),
				       1);
		}
		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
			print_hex_dump(KERN_ERR, "SPI TX: ",
				       DUMP_PREFIX_OFFSET,
				       16,
				       1,
				       sg_virt(sg),
				       sg_dma_len(sg),
				       1);
		}
	}
#endif

	unmap_free_dma_scatter(pl022);

	/* Update total bytes transferred */
	msg->actual_length += pl022->cur_transfer->len;
	if (pl022->cur_transfer->cs_change)
		pl022->cur_chip->
			cs_control(SSP_CHIP_DESELECT);

	/* Move to next transfer */
	msg->state = next_transfer(pl022);
	tasklet_schedule(&pl022->pump_transfers);
}

static void setup_dma_scatter(struct pl022 *pl022,
			      void *buffer,
			      unsigned int length,
			      struct sg_table *sgtab)
{
	struct scatterlist *sg;
	int bytesleft = length;
	void *bufp = buffer;
	int mapbytes;
	int i;

	if (buffer) {
		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
			/*
			 * If there are less bytes left than what fits
			 * in the current page (plus page alignment offset)
			 * we just feed in this, else we stuff in as much
			 * as we can.
			 */
			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
				mapbytes = bytesleft;
			else
				mapbytes = PAGE_SIZE - offset_in_page(bufp);
			sg_set_page(sg, virt_to_page(bufp),
				    mapbytes, offset_in_page(bufp));
			bufp += mapbytes;
			bytesleft -= mapbytes;
			dev_dbg(&pl022->adev->dev,
				"set RX/TX target page @ %p, %d bytes, %d left\n",
				bufp, mapbytes, bytesleft);
		}
	} else {
		/* Map the dummy buffer on every page */
		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
			if (bytesleft < PAGE_SIZE)
				mapbytes = bytesleft;
			else
				mapbytes = PAGE_SIZE;
			sg_set_page(sg, virt_to_page(pl022->dummypage),
				    mapbytes, 0);
			bytesleft -= mapbytes;
			dev_dbg(&pl022->adev->dev,
				"set RX/TX to dummy page %d bytes, %d left\n",
				mapbytes, bytesleft);

		}
	}
	BUG_ON(bytesleft);
}

/**
 * configure_dma - configures the channels for the next transfer
 * @pl022: SSP driver's private data structure
 */
static int configure_dma(struct pl022 *pl022)
{
	struct dma_slave_config rx_conf = {
		.src_addr = SSP_DR(pl022->phybase),
		.direction = DMA_DEV_TO_MEM,
	};
	struct dma_slave_config tx_conf = {
		.dst_addr = SSP_DR(pl022->phybase),
		.direction = DMA_MEM_TO_DEV,
	};
	unsigned int pages;
	int ret;
	int rx_sglen, tx_sglen;
	struct dma_chan *rxchan = pl022->dma_rx_channel;
	struct dma_chan *txchan = pl022->dma_tx_channel;
	struct dma_async_tx_descriptor *rxdesc;
	struct dma_async_tx_descriptor *txdesc;

	/* Check that the channels are available */
	if (!rxchan || !txchan)
		return -ENODEV;

	/*
	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
	 * Notice that the DMA engine uses one-to-one mapping. Since we can
	 * not trigger on 2 elements this needs explicit mapping rather than
	 * calculation.
	 */
	switch (pl022->rx_lev_trig) {
	case SSP_RX_1_OR_MORE_ELEM:
		rx_conf.src_maxburst = 1;
		break;
	case SSP_RX_4_OR_MORE_ELEM:
		rx_conf.src_maxburst = 4;
		break;
	case SSP_RX_8_OR_MORE_ELEM:
		rx_conf.src_maxburst = 8;
		break;
	case SSP_RX_16_OR_MORE_ELEM:
		rx_conf.src_maxburst = 16;
		break;
	case SSP_RX_32_OR_MORE_ELEM:
		rx_conf.src_maxburst = 32;
		break;
	default:
		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
		break;
	}

	switch (pl022->tx_lev_trig) {
	case SSP_TX_1_OR_MORE_EMPTY_LOC:
		tx_conf.dst_maxburst = 1;
		break;
	case SSP_TX_4_OR_MORE_EMPTY_LOC:
		tx_conf.dst_maxburst = 4;
		break;
	case SSP_TX_8_OR_MORE_EMPTY_LOC:
		tx_conf.dst_maxburst = 8;
		break;
	case SSP_TX_16_OR_MORE_EMPTY_LOC:
		tx_conf.dst_maxburst = 16;
		break;
	case SSP_TX_32_OR_MORE_EMPTY_LOC:
		tx_conf.dst_maxburst = 32;
		break;
	default:
		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
		break;
	}

	switch (pl022->read) {
	case READING_NULL:
		/* Use the same as for writing */
		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
		break;
	case READING_U8:
		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
		break;
	case READING_U16:
		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		break;
	case READING_U32:
		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		break;
	}

	switch (pl022->write) {
	case WRITING_NULL:
		/* Use the same as for reading */
		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
		break;
	case WRITING_U8:
		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
		break;
	case WRITING_U16:
		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		break;
	case WRITING_U32:
		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		break;
	}

	/* SPI pecularity: we need to read and write the same width */
	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
		rx_conf.src_addr_width = tx_conf.dst_addr_width;
	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
		tx_conf.dst_addr_width = rx_conf.src_addr_width;
	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);

	dmaengine_slave_config(rxchan, &rx_conf);
	dmaengine_slave_config(txchan, &tx_conf);

	/* Create sglists for the transfers */
	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);

	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
	if (ret)
		goto err_alloc_rx_sg;

	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
	if (ret)
		goto err_alloc_tx_sg;

	/* Fill in the scatterlists for the RX+TX buffers */
	setup_dma_scatter(pl022, pl022->rx,
			  pl022->cur_transfer->len, &pl022->sgt_rx);
	setup_dma_scatter(pl022, pl022->tx,
			  pl022->cur_transfer->len, &pl022->sgt_tx);

	/* Map DMA buffers */
	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
	if (!rx_sglen)
		goto err_rx_sgmap;

	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
	if (!tx_sglen)
		goto err_tx_sgmap;

	/* Send both scatterlists */
	rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
				      pl022->sgt_rx.sgl,
				      rx_sglen,
				      DMA_DEV_TO_MEM,
				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!rxdesc)
		goto err_rxdesc;

	txdesc = txchan->device->device_prep_slave_sg(txchan,
				      pl022->sgt_tx.sgl,
				      tx_sglen,
				      DMA_MEM_TO_DEV,
				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!txdesc)
		goto err_txdesc;

	/* Put the callback on the RX transfer only, that should finish last */
	rxdesc->callback = dma_callback;
	rxdesc->callback_param = pl022;

	/* Submit and fire RX and TX with TX last so we're ready to read! */
	dmaengine_submit(rxdesc);
	dmaengine_submit(txdesc);
	dma_async_issue_pending(rxchan);
	dma_async_issue_pending(txchan);

	return 0;

err_txdesc:
	dmaengine_terminate_all(txchan);
err_rxdesc:
	dmaengine_terminate_all(rxchan);
	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
err_tx_sgmap:
	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
		     pl022->sgt_tx.nents, DMA_FROM_DEVICE);
err_rx_sgmap:
	sg_free_table(&pl022->sgt_tx);
err_alloc_tx_sg:
	sg_free_table(&pl022->sgt_rx);
err_alloc_rx_sg:
	return -ENOMEM;
}

static int __init pl022_dma_probe(struct pl022 *pl022)
{
	dma_cap_mask_t mask;

	/* Try to acquire a generic DMA engine slave channel */
	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);
	/*
	 * We need both RX and TX channels to do DMA, else do none
	 * of them.
	 */
	pl022->dma_rx_channel = dma_request_channel(mask,
					    pl022->master_info->dma_filter,
					    pl022->master_info->dma_rx_param);
	if (!pl022->dma_rx_channel) {
		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
		goto err_no_rxchan;
	}

	pl022->dma_tx_channel = dma_request_channel(mask,
					    pl022->master_info->dma_filter,
					    pl022->master_info->dma_tx_param);
	if (!pl022->dma_tx_channel) {
		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
		goto err_no_txchan;
	}

	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!pl022->dummypage) {
		dev_dbg(&pl022->adev->dev, "no DMA dummypage!\n");
		goto err_no_dummypage;
	}

	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
		 dma_chan_name(pl022->dma_rx_channel),
		 dma_chan_name(pl022->dma_tx_channel));

	return 0;

err_no_dummypage:
	dma_release_channel(pl022->dma_tx_channel);
err_no_txchan:
	dma_release_channel(pl022->dma_rx_channel);
	pl022->dma_rx_channel = NULL;
err_no_rxchan:
	dev_err(&pl022->adev->dev,
			"Failed to work in dma mode, work without dma!\n");
	return -ENODEV;
}

static void terminate_dma(struct pl022 *pl022)
{
	struct dma_chan *rxchan = pl022->dma_rx_channel;
	struct dma_chan *txchan = pl022->dma_tx_channel;

	dmaengine_terminate_all(rxchan);
	dmaengine_terminate_all(txchan);
	unmap_free_dma_scatter(pl022);
}

static void pl022_dma_remove(struct pl022 *pl022)
{
	if (pl022->busy)
		terminate_dma(pl022);
	if (pl022->dma_tx_channel)
		dma_release_channel(pl022->dma_tx_channel);
	if (pl022->dma_rx_channel)
		dma_release_channel(pl022->dma_rx_channel);
	kfree(pl022->dummypage);
}

#else
static inline int configure_dma(struct pl022 *pl022)
{
	return -ENODEV;
}

static inline int pl022_dma_probe(struct pl022 *pl022)
{
	return 0;
}

static inline void pl022_dma_remove(struct pl022 *pl022)
{
}
#endif

/**
 * pl022_interrupt_handler - Interrupt handler for SSP controller
 *
 * This function handles interrupts generated for an interrupt based transfer.
 * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
 * current message's state as STATE_ERROR and schedule the tasklet
 * pump_transfers which will do the postprocessing of the current message by
 * calling giveback(). Otherwise it reads data from RX FIFO till there is no
 * more data, and writes data in TX FIFO till it is not full. If we complete
 * the transfer we move to the next transfer and schedule the tasklet.
 */
static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
{
	struct pl022 *pl022 = dev_id;
	struct spi_message *msg = pl022->cur_msg;
	u16 irq_status = 0;
	u16 flag = 0;

	if (unlikely(!msg)) {
		dev_err(&pl022->adev->dev,
			"bad message state in interrupt handler");
		/* Never fail */
		return IRQ_HANDLED;
	}

	/* Read the Interrupt Status Register */
	irq_status = readw(SSP_MIS(pl022->virtbase));

	if (unlikely(!irq_status))
		return IRQ_NONE;

	/*
	 * This handles the FIFO interrupts, the timeout
	 * interrupts are flatly ignored, they cannot be
	 * trusted.
	 */
	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
		/*
		 * Overrun interrupt - bail out since our Data has been
		 * corrupted
		 */
		dev_err(&pl022->adev->dev, "FIFO overrun\n");
		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
			dev_err(&pl022->adev->dev,
				"RXFIFO is full\n");
		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
			dev_err(&pl022->adev->dev,
				"TXFIFO is full\n");

		/*
		 * Disable and clear interrupts, disable SSP,
		 * mark message with bad status so it can be
		 * retried.
		 */
		writew(DISABLE_ALL_INTERRUPTS,
		       SSP_IMSC(pl022->virtbase));
		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
		writew((readw(SSP_CR1(pl022->virtbase)) &
			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
		msg->state = STATE_ERROR;

		/* Schedule message queue handler */
		tasklet_schedule(&pl022->pump_transfers);
		return IRQ_HANDLED;
	}

	readwriter(pl022);

	if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
		flag = 1;
		/* Disable Transmit interrupt, enable receive interrupt */
		writew((readw(SSP_IMSC(pl022->virtbase)) &
		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
		       SSP_IMSC(pl022->virtbase));
	}

	/*
	 * Since all transactions must write as much as shall be read,
	 * we can conclude the entire transaction once RX is complete.
	 * At this point, all TX will always be finished.
	 */
	if (pl022->rx >= pl022->rx_end) {
		writew(DISABLE_ALL_INTERRUPTS,
		       SSP_IMSC(pl022->virtbase));
		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
		if (unlikely(pl022->rx > pl022->rx_end)) {
			dev_warn(&pl022->adev->dev, "read %u surplus "
				 "bytes (did you request an odd "
				 "number of bytes on a 16bit bus?)\n",
				 (u32) (pl022->rx - pl022->rx_end));
		}
		/* Update total bytes transferred */
		msg->actual_length += pl022->cur_transfer->len;
		if (pl022->cur_transfer->cs_change)
			pl022->cur_chip->
				cs_control(SSP_CHIP_DESELECT);
		/* Move to next transfer */
		msg->state = next_transfer(pl022);
		tasklet_schedule(&pl022->pump_transfers);
		return IRQ_HANDLED;
	}

	return IRQ_HANDLED;
}

/**
 * This sets up the pointers to memory for the next message to
 * send out on the SPI bus.
 */
static int set_up_next_transfer(struct pl022 *pl022,
				struct spi_transfer *transfer)
{
	int residue;

	/* Sanity check the message for this bus width */
	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
	if (unlikely(residue != 0)) {
		dev_err(&pl022->adev->dev,
			"message of %u bytes to transmit but the current "
			"chip bus has a data width of %u bytes!\n",
			pl022->cur_transfer->len,
			pl022->cur_chip->n_bytes);
		dev_err(&pl022->adev->dev, "skipping this message\n");
		return -EIO;
	}
	pl022->tx = (void *)transfer->tx_buf;
	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
	pl022->rx = (void *)transfer->rx_buf;
	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
	pl022->write =
	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
	return 0;
}

/**
 * pump_transfers - Tasklet function which schedules next transfer
 * when running in interrupt or DMA transfer mode.
 * @data: SSP driver private data structure
 *
 */
static void pump_transfers(unsigned long data)
{
	struct pl022 *pl022 = (struct pl022 *) data;
	struct spi_message *message = NULL;
	struct spi_transfer *transfer = NULL;
	struct spi_transfer *previous = NULL;

	/* Get current state information */
	message = pl022->cur_msg;
	transfer = pl022->cur_transfer;

	/* Handle for abort */
	if (message->state == STATE_ERROR) {
		message->status = -EIO;
		giveback(pl022);
		return;
	}

	/* Handle end of message */
	if (message->state == STATE_DONE) {
		message->status = 0;
		giveback(pl022);
		return;
	}

	/* Delay if requested at end of transfer before CS change */
	if (message->state == STATE_RUNNING) {
		previous = list_entry(transfer->transfer_list.prev,
					struct spi_transfer,
					transfer_list);
		if (previous->delay_usecs)
			/*
			 * FIXME: This runs in interrupt context.
			 * Is this really smart?
			 */
			udelay(previous->delay_usecs);

		/* Reselect chip select only if cs_change was requested */
		if (previous->cs_change)
			pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
	} else {
		/* STATE_START */
		message->state = STATE_RUNNING;
	}

	if (set_up_next_transfer(pl022, transfer)) {
		message->state = STATE_ERROR;
		message->status = -EIO;
		giveback(pl022);
		return;
	}
	/* Flush the FIFOs and let's go! */
	flush(pl022);

	if (pl022->cur_chip->enable_dma) {
		if (configure_dma(pl022)) {
			dev_dbg(&pl022->adev->dev,
				"configuration of DMA failed, fall back to interrupt mode\n");
			goto err_config_dma;
		}
		return;
	}

err_config_dma:
	/* enable all interrupts except RX */
	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
}

static void do_interrupt_dma_transfer(struct pl022 *pl022)
{
	/*
	 * Default is to enable all interrupts except RX -
	 * this will be enabled once TX is complete
	 */
	u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM;

	/* Enable target chip, if not already active */
	if (!pl022->next_msg_cs_active)
		pl022->cur_chip->cs_control(SSP_CHIP_SELECT);

	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
		/* Error path */
		pl022->cur_msg->state = STATE_ERROR;
		pl022->cur_msg->status = -EIO;
		giveback(pl022);
		return;
	}
	/* If we're using DMA, set up DMA here */
	if (pl022->cur_chip->enable_dma) {
		/* Configure DMA transfer */
		if (configure_dma(pl022)) {
			dev_dbg(&pl022->adev->dev,
				"configuration of DMA failed, fall back to interrupt mode\n");
			goto err_config_dma;
		}
		/* Disable interrupts in DMA mode, IRQ from DMA controller */
		irqflags = DISABLE_ALL_INTERRUPTS;
	}
err_config_dma:
	/* Enable SSP, turn on interrupts */
	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
	       SSP_CR1(pl022->virtbase));
	writew(irqflags, SSP_IMSC(pl022->virtbase));
}

static void do_polling_transfer(struct pl022 *pl022)
{
	struct spi_message *message = NULL;
	struct spi_transfer *transfer = NULL;
	struct spi_transfer *previous = NULL;
	struct chip_data *chip;
	unsigned long time, timeout;

	chip = pl022->cur_chip;
	message = pl022->cur_msg;

	while (message->state != STATE_DONE) {
		/* Handle for abort */
		if (message->state == STATE_ERROR)
			break;
		transfer = pl022->cur_transfer;

		/* Delay if requested at end of transfer */
		if (message->state == STATE_RUNNING) {
			previous =
			    list_entry(transfer->transfer_list.prev,
				       struct spi_transfer, transfer_list);
			if (previous->delay_usecs)
				udelay(previous->delay_usecs);
			if (previous->cs_change)
				pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
		} else {
			/* STATE_START */
			message->state = STATE_RUNNING;
			if (!pl022->next_msg_cs_active)
				pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
		}

		/* Configuration Changing Per Transfer */
		if (set_up_next_transfer(pl022, transfer)) {
			/* Error path */
			message->state = STATE_ERROR;
			break;
		}
		/* Flush FIFOs and enable SSP */
		flush(pl022);
		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
		       SSP_CR1(pl022->virtbase));

		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");

		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
			time = jiffies;
			readwriter(pl022);
			if (time_after(time, timeout)) {
				dev_warn(&pl022->adev->dev,
				"%s: timeout!\n", __func__);
				message->state = STATE_ERROR;
				goto out;
			}
			cpu_relax();
		}

		/* Update total byte transferred */
		message->actual_length += pl022->cur_transfer->len;
		if (pl022->cur_transfer->cs_change)
			pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
		/* Move to next transfer */
		message->state = next_transfer(pl022);
	}
out:
	/* Handle end of message */
	if (message->state == STATE_DONE)
		message->status = 0;
	else
		message->status = -EIO;

	giveback(pl022);
	return;
}

/**
 * pump_messages - kthread work function which processes spi message queue
 * @work: pointer to kthread work struct contained in the pl022 private struct
 *
 * This function checks if there is any spi message in the queue that
 * needs processing and delegate control to appropriate function
 * do_polling_transfer()/do_interrupt_dma_transfer()
 * based on the kind of the transfer
 *
 */
static void pump_messages(struct kthread_work *work)
{
	struct pl022 *pl022 =
		container_of(work, struct pl022, pump_messages);
	unsigned long flags;
	bool was_busy = false;

	/* Lock queue and check for queue work */
	spin_lock_irqsave(&pl022->queue_lock, flags);
	if (list_empty(&pl022->queue) || !pl022->running) {
		if (pl022->busy) {
			/* nothing more to do - disable spi/ssp and power off */
			writew((readw(SSP_CR1(pl022->virtbase)) &
				(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));

			if (pl022->master_info->autosuspend_delay > 0) {
				pm_runtime_mark_last_busy(&pl022->adev->dev);
				pm_runtime_put_autosuspend(&pl022->adev->dev);
			} else {
				pm_runtime_put(&pl022->adev->dev);
			}
		}
		pl022->busy = false;
		spin_unlock_irqrestore(&pl022->queue_lock, flags);
		return;
	}

	/* Make sure we are not already running a message */
	if (pl022->cur_msg) {
		spin_unlock_irqrestore(&pl022->queue_lock, flags);
		return;
	}
	/* Extract head of queue */
	pl022->cur_msg =
	    list_entry(pl022->queue.next, struct spi_message, queue);

	list_del_init(&pl022->cur_msg->queue);
	if (pl022->busy)
		was_busy = true;
	else
		pl022->busy = true;
	spin_unlock_irqrestore(&pl022->queue_lock, flags);

	/* Initial message state */
	pl022->cur_msg->state = STATE_START;
	pl022->cur_transfer = list_entry(pl022->cur_msg->transfers.next,
					    struct spi_transfer, transfer_list);

	/* Setup the SPI using the per chip configuration */
	pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi);
	if (!was_busy)
		/*
		 * We enable the core voltage and clocks here, then the clocks
		 * and core will be disabled when this thread is run again
		 * and there is no more work to be done.
		 */
		pm_runtime_get_sync(&pl022->adev->dev);

	restore_state(pl022);
	flush(pl022);

	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
		do_polling_transfer(pl022);
	else
		do_interrupt_dma_transfer(pl022);
}

static int __init init_queue(struct pl022 *pl022)
{
	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };

	INIT_LIST_HEAD(&pl022->queue);
	spin_lock_init(&pl022->queue_lock);

	pl022->running = false;
	pl022->busy = false;

	tasklet_init(&pl022->pump_transfers, pump_transfers,
			(unsigned long)pl022);

	init_kthread_worker(&pl022->kworker);
	pl022->kworker_task = kthread_run(kthread_worker_fn,
					&pl022->kworker,
					dev_name(pl022->master->dev.parent));
	if (IS_ERR(pl022->kworker_task)) {
		dev_err(&pl022->adev->dev,
			"failed to create message pump task\n");
		return -ENOMEM;
	}
	init_kthread_work(&pl022->pump_messages, pump_messages);

	/*
	 * Board config will indicate if this controller should run the
	 * message pump with high (realtime) priority to reduce the transfer
	 * latency on the bus by minimising the delay between a transfer
	 * request and the scheduling of the message pump thread. Without this
	 * setting the message pump thread will remain at default priority.
	 */
	if (pl022->master_info->rt) {
		dev_info(&pl022->adev->dev,
			"will run message pump with realtime priority\n");
		sched_setscheduler(pl022->kworker_task, SCHED_FIFO, &param);
	}

	return 0;
}

static int start_queue(struct pl022 *pl022)
{
	unsigned long flags;

	spin_lock_irqsave(&pl022->queue_lock, flags);

	if (pl022->running || pl022->busy) {
		spin_unlock_irqrestore(&pl022->queue_lock, flags);
		return -EBUSY;
	}

	pl022->running = true;
	pl022->cur_msg = NULL;
	pl022->cur_transfer = NULL;
	pl022->cur_chip = NULL;
	pl022->next_msg_cs_active = false;
	spin_unlock_irqrestore(&pl022->queue_lock, flags);

	queue_kthread_work(&pl022->kworker, &pl022->pump_messages);

	return 0;
}

static int stop_queue(struct pl022 *pl022)
{
	unsigned long flags;
	unsigned limit = 500;
	int status = 0;

	spin_lock_irqsave(&pl022->queue_lock, flags);

	/* This is a bit lame, but is optimized for the common execution path.
	 * A wait_queue on the pl022->busy could be used, but then the common
	 * execution path (pump_messages) would be required to call wake_up or
	 * friends on every SPI message. Do this instead */
	while ((!list_empty(&pl022->queue) || pl022->busy) && limit--) {
		spin_unlock_irqrestore(&pl022->queue_lock, flags);
		msleep(10);
		spin_lock_irqsave(&pl022->queue_lock, flags);
	}

	if (!list_empty(&pl022->queue) || pl022->busy)
		status = -EBUSY;
	else
		pl022->running = false;

	spin_unlock_irqrestore(&pl022->queue_lock, flags);

	return status;
}

static int destroy_queue(struct pl022 *pl022)
{
	int status;

	status = stop_queue(pl022);

	/*
	 * We are unloading the module or failing to load (only two calls
	 * to this routine), and neither call can handle a return value.
	 * However, flush_kthread_worker will block until all work is done.
	 * If the reason that stop_queue timed out is that the work will never
	 * finish, then it does no good to call flush/stop thread, so
	 * return anyway.
	 */
	if (status != 0)
		return status;

	flush_kthread_worker(&pl022->kworker);
	kthread_stop(pl022->kworker_task);

	return 0;
}

static int verify_controller_parameters(struct pl022 *pl022,
				struct pl022_config_chip const *chip_info)
{
	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
		dev_err(&pl022->adev->dev,
			"interface is configured incorrectly\n");
		return -EINVAL;
	}
	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
	    (!pl022->vendor->unidir)) {
		dev_err(&pl022->adev->dev,
			"unidirectional mode not supported in this "
			"hardware version\n");
		return -EINVAL;
	}
	if ((chip_info->hierarchy != SSP_MASTER)
	    && (chip_info->hierarchy != SSP_SLAVE)) {
		dev_err(&pl022->adev->dev,
			"hierarchy is configured incorrectly\n");
		return -EINVAL;
	}
	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
	    && (chip_info->com_mode != DMA_TRANSFER)
	    && (chip_info->com_mode != POLLING_TRANSFER)) {
		dev_err(&pl022->adev->dev,
			"Communication mode is configured incorrectly\n");
		return -EINVAL;
	}
	switch (chip_info->rx_lev_trig) {
	case SSP_RX_1_OR_MORE_ELEM:
	case SSP_RX_4_OR_MORE_ELEM:
	case SSP_RX_8_OR_MORE_ELEM:
		/* These are always OK, all variants can handle this */
		break;
	case SSP_RX_16_OR_MORE_ELEM:
		if (pl022->vendor->fifodepth < 16) {
			dev_err(&pl022->adev->dev,
			"RX FIFO Trigger Level is configured incorrectly\n");
			return -EINVAL;
		}
		break;
	case SSP_RX_32_OR_MORE_ELEM:
		if (pl022->vendor->fifodepth < 32) {
			dev_err(&pl022->adev->dev,
			"RX FIFO Trigger Level is configured incorrectly\n");
			return -EINVAL;
		}
		break;
	default:
		dev_err(&pl022->adev->dev,
			"RX FIFO Trigger Level is configured incorrectly\n");
		return -EINVAL;
		break;
	}
	switch (chip_info->tx_lev_trig) {
	case SSP_TX_1_OR_MORE_EMPTY_LOC:
	case SSP_TX_4_OR_MORE_EMPTY_LOC:
	case SSP_TX_8_OR_MORE_EMPTY_LOC:
		/* These are always OK, all variants can handle this */
		break;
	case SSP_TX_16_OR_MORE_EMPTY_LOC:
		if (pl022->vendor->fifodepth < 16) {
			dev_err(&pl022->adev->dev,
			"TX FIFO Trigger Level is configured incorrectly\n");
			return -EINVAL;
		}
		break;
	case SSP_TX_32_OR_MORE_EMPTY_LOC:
		if (pl022->vendor->fifodepth < 32) {
			dev_err(&pl022->adev->dev,
			"TX FIFO Trigger Level is configured incorrectly\n");
			return -EINVAL;
		}
		break;
	default:
		dev_err(&pl022->adev->dev,
			"TX FIFO Trigger Level is configured incorrectly\n");
		return -EINVAL;
		break;
	}
	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
		if ((chip_info->ctrl_len < SSP_BITS_4)
		    || (chip_info->ctrl_len > SSP_BITS_32)) {
			dev_err(&pl022->adev->dev,
				"CTRL LEN is configured incorrectly\n");
			return -EINVAL;
		}
		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
			dev_err(&pl022->adev->dev,
				"Wait State is configured incorrectly\n");
			return -EINVAL;
		}
		/* Half duplex is only available in the ST Micro version */
		if (pl022->vendor->extended_cr) {
			if ((chip_info->duplex !=
			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
			    && (chip_info->duplex !=
				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
				dev_err(&pl022->adev->dev,
					"Microwire duplex mode is configured incorrectly\n");
				return -EINVAL;
			}
		} else {
			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
				dev_err(&pl022->adev->dev,
					"Microwire half duplex mode requested,"
					" but this is only available in the"
					" ST version of PL022\n");
			return -EINVAL;
		}
	}
	return 0;
}

/**
 * pl022_transfer - transfer function registered to SPI master framework
 * @spi: spi device which is requesting transfer
 * @msg: spi message which is to handled is queued to driver queue
 *
 * This function is registered to the SPI framework for this SPI master
 * controller. It will queue the spi_message in the queue of driver if
 * the queue is not stopped and return.
 */
static int pl022_transfer(struct spi_device *spi, struct spi_message *msg)
{
	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
	unsigned long flags;

	spin_lock_irqsave(&pl022->queue_lock, flags);

	if (!pl022->running) {
		spin_unlock_irqrestore(&pl022->queue_lock, flags);
		return -ESHUTDOWN;
	}
	msg->actual_length = 0;
	msg->status = -EINPROGRESS;
	msg->state = STATE_START;

	list_add_tail(&msg->queue, &pl022->queue);
	if (pl022->running && !pl022->busy)
		queue_kthread_work(&pl022->kworker, &pl022->pump_messages);

	spin_unlock_irqrestore(&pl022->queue_lock, flags);
	return 0;
}

static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
{
	return rate / (cpsdvsr * (1 + scr));
}

static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
				    ssp_clock_params * clk_freq)
{
	/* Lets calculate the frequency parameters */
	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
		best_scr = 0, tmp, found = 0;

	rate = clk_get_rate(pl022->clk);
	/* cpsdvscr = 2 & scr 0 */
	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
	/* cpsdvsr = 254 & scr = 255 */
	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);

	if (!((freq <= max_tclk) && (freq >= min_tclk))) {
		dev_err(&pl022->adev->dev,
			"controller data is incorrect: out of range frequency");
		return -EINVAL;
	}

	/*
	 * best_freq will give closest possible available rate (<= requested
	 * freq) for all values of scr & cpsdvsr.
	 */
	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
		while (scr <= SCR_MAX) {
			tmp = spi_rate(rate, cpsdvsr, scr);

			if (tmp > freq)
				scr++;
			/*
			 * If found exact value, update and break.
			 * If found more closer value, update and continue.
			 */
			else if ((tmp == freq) || (tmp > best_freq)) {
				best_freq = tmp;
				best_cpsdvsr = cpsdvsr;
				best_scr = scr;

				if (tmp == freq)
					break;
			}
			scr++;
		}
		cpsdvsr += 2;
		scr = SCR_MIN;
	}

	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
	clk_freq->scr = (u8) (best_scr & 0xFF);
	dev_dbg(&pl022->adev->dev,
		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
		freq, best_freq);
	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
		clk_freq->cpsdvsr, clk_freq->scr);

	return 0;
}

/*
 * A piece of default chip info unless the platform
 * supplies it.
 */
static const struct pl022_config_chip pl022_default_chip_info = {
	.com_mode = POLLING_TRANSFER,
	.iface = SSP_INTERFACE_MOTOROLA_SPI,
	.hierarchy = SSP_SLAVE,
	.slave_tx_disable = DO_NOT_DRIVE_TX,
	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
	.ctrl_len = SSP_BITS_8,
	.wait_state = SSP_MWIRE_WAIT_ZERO,
	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
	.cs_control = null_cs_control,
};

/**
 * pl022_setup - setup function registered to SPI master framework
 * @spi: spi device which is requesting setup
 *
 * This function is registered to the SPI framework for this SPI master
 * controller. If it is the first time when setup is called by this device,
 * this function will initialize the runtime state for this chip and save
 * the same in the device structure. Else it will update the runtime info
 * with the updated chip info. Nothing is really being written to the
 * controller hardware here, that is not done until the actual transfer
 * commence.
 */
static int pl022_setup(struct spi_device *spi)
{
	struct pl022_config_chip const *chip_info;
	struct chip_data *chip;
	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
	int status = 0;
	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
	unsigned int bits = spi->bits_per_word;
	u32 tmp;

	if (!spi->max_speed_hz)
		return -EINVAL;

	/* Get controller_state if one is supplied */
	chip = spi_get_ctldata(spi);

	if (chip == NULL) {
		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
		if (!chip) {
			dev_err(&spi->dev,
				"cannot allocate controller state\n");
			return -ENOMEM;
		}
		dev_dbg(&spi->dev,
			"allocated memory for controller's runtime state\n");
	}

	/* Get controller data if one is supplied */
	chip_info = spi->controller_data;

	if (chip_info == NULL) {
		chip_info = &pl022_default_chip_info;
		/* spi_board_info.controller_data not is supplied */
		dev_dbg(&spi->dev,
			"using default controller_data settings\n");
	} else
		dev_dbg(&spi->dev,
			"using user supplied controller_data settings\n");

	/*
	 * We can override with custom divisors, else we use the board
	 * frequency setting
	 */
	if ((0 == chip_info->clk_freq.cpsdvsr)
	    && (0 == chip_info->clk_freq.scr)) {
		status = calculate_effective_freq(pl022,
						  spi->max_speed_hz,
						  &clk_freq);
		if (status < 0)
			goto err_config_params;
	} else {
		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
		if ((clk_freq.cpsdvsr % 2) != 0)
			clk_freq.cpsdvsr =
				clk_freq.cpsdvsr - 1;
	}
	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
		status = -EINVAL;
		dev_err(&spi->dev,
			"cpsdvsr is configured incorrectly\n");
		goto err_config_params;
	}

	status = verify_controller_parameters(pl022, chip_info);
	if (status) {
		dev_err(&spi->dev, "controller data is incorrect");
		goto err_config_params;
	}

	pl022->rx_lev_trig = chip_info->rx_lev_trig;
	pl022->tx_lev_trig = chip_info->tx_lev_trig;

	/* Now set controller state based on controller data */
	chip->xfer_type = chip_info->com_mode;
	if (!chip_info->cs_control) {
		chip->cs_control = null_cs_control;
		dev_warn(&spi->dev,
			 "chip select function is NULL for this chip\n");
	} else
		chip->cs_control = chip_info->cs_control;

	if (bits <= 3) {
		/* PL022 doesn't support less than 4-bits */
		status = -ENOTSUPP;
		goto err_config_params;
	} else if (bits <= 8) {
		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
		chip->n_bytes = 1;
		chip->read = READING_U8;
		chip->write = WRITING_U8;
	} else if (bits <= 16) {
		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
		chip->n_bytes = 2;
		chip->read = READING_U16;
		chip->write = WRITING_U16;
	} else {
		if (pl022->vendor->max_bpw >= 32) {
			dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
			chip->n_bytes = 4;
			chip->read = READING_U32;
			chip->write = WRITING_U32;
		} else {
			dev_err(&spi->dev,
				"illegal data size for this controller!\n");
			dev_err(&spi->dev,
				"a standard pl022 can only handle "
				"1 <= n <= 16 bit words\n");
			status = -ENOTSUPP;
			goto err_config_params;
		}
	}

	/* Now Initialize all register settings required for this chip */
	chip->cr0 = 0;
	chip->cr1 = 0;
	chip->dmacr = 0;
	chip->cpsr = 0;
	if ((chip_info->com_mode == DMA_TRANSFER)
	    && ((pl022->master_info)->enable_dma)) {
		chip->enable_dma = true;
		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
			       SSP_DMACR_MASK_RXDMAE, 0);
		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
			       SSP_DMACR_MASK_TXDMAE, 1);
	} else {
		chip->enable_dma = false;
		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
			       SSP_DMACR_MASK_RXDMAE, 0);
		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
			       SSP_DMACR_MASK_TXDMAE, 1);
	}

	chip->cpsr = clk_freq.cpsdvsr;

	/* Special setup for the ST micro extended control registers */
	if (pl022->vendor->extended_cr) {
		u32 etx;

		if (pl022->vendor->pl023) {
			/* These bits are only in the PL023 */
			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
		} else {
			/* These bits are in the PL022 but not PL023 */
			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
				       SSP_CR0_MASK_HALFDUP_ST, 5);
			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
				       SSP_CR0_MASK_CSS_ST, 16);
			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
				       SSP_CR0_MASK_FRF_ST, 21);
			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
				       SSP_CR1_MASK_MWAIT_ST, 6);
		}
		SSP_WRITE_BITS(chip->cr0, bits - 1,
			       SSP_CR0_MASK_DSS_ST, 0);

		if (spi->mode & SPI_LSB_FIRST) {
			tmp = SSP_RX_LSB;
			etx = SSP_TX_LSB;
		} else {
			tmp = SSP_RX_MSB;
			etx = SSP_TX_MSB;
		}
		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
	} else {
		SSP_WRITE_BITS(chip->cr0, bits - 1,
			       SSP_CR0_MASK_DSS, 0);
		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
			       SSP_CR0_MASK_FRF, 4);
	}

	/* Stuff that is common for all versions */
	if (spi->mode & SPI_CPOL)
		tmp = SSP_CLK_POL_IDLE_HIGH;
	else
		tmp = SSP_CLK_POL_IDLE_LOW;
	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);

	if (spi->mode & SPI_CPHA)
		tmp = SSP_CLK_SECOND_EDGE;
	else
		tmp = SSP_CLK_FIRST_EDGE;
	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);

	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
	/* Loopback is available on all versions except PL023 */
	if (pl022->vendor->loopback) {
		if (spi->mode & SPI_LOOP)
			tmp = LOOPBACK_ENABLED;
		else
			tmp = LOOPBACK_DISABLED;
		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
	}
	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
		3);

	/* Save controller_state */
	spi_set_ctldata(spi, chip);
	return status;
 err_config_params:
	spi_set_ctldata(spi, NULL);
	kfree(chip);
	return status;
}

/**
 * pl022_cleanup - cleanup function registered to SPI master framework
 * @spi: spi device which is requesting cleanup
 *
 * This function is registered to the SPI framework for this SPI master
 * controller. It will free the runtime state of chip.
 */
static void pl022_cleanup(struct spi_device *spi)
{
	struct chip_data *chip = spi_get_ctldata(spi);

	spi_set_ctldata(spi, NULL);
	kfree(chip);
}

static int __devinit
pl022_probe(struct amba_device *adev, const struct amba_id *id)
{
	struct device *dev = &adev->dev;
	struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
	struct spi_master *master;
	struct pl022 *pl022 = NULL;	/*Data for this driver */
	int status = 0;

	dev_info(&adev->dev,
		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
	if (platform_info == NULL) {
		dev_err(&adev->dev, "probe - no platform data supplied\n");
		status = -ENODEV;
		goto err_no_pdata;
	}

	/* Allocate master with space for data */
	master = spi_alloc_master(dev, sizeof(struct pl022));
	if (master == NULL) {
		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
		status = -ENOMEM;
		goto err_no_master;
	}

	pl022 = spi_master_get_devdata(master);
	pl022->master = master;
	pl022->master_info = platform_info;
	pl022->adev = adev;
	pl022->vendor = id->data;

	/*
	 * Bus Number Which has been Assigned to this SSP controller
	 * on this board
	 */
	master->bus_num = platform_info->bus_id;
	master->num_chipselect = platform_info->num_chipselect;
	master->cleanup = pl022_cleanup;
	master->setup = pl022_setup;
	master->transfer = pl022_transfer;

	/*
	 * Supports mode 0-3, loopback, and active low CS. Transfers are
	 * always MS bit first on the original pl022.
	 */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
	if (pl022->vendor->extended_cr)
		master->mode_bits |= SPI_LSB_FIRST;

	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);

	status = amba_request_regions(adev, NULL);
	if (status)
		goto err_no_ioregion;

	pl022->phybase = adev->res.start;
	pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
	if (pl022->virtbase == NULL) {
		status = -ENOMEM;
		goto err_no_ioremap;
	}
	printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n",
	       adev->res.start, pl022->virtbase);

	pl022->clk = clk_get(&adev->dev, NULL);
	if (IS_ERR(pl022->clk)) {
		status = PTR_ERR(pl022->clk);
		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
		goto err_no_clk;
	}

	status = clk_prepare(pl022->clk);
	if (status) {
		dev_err(&adev->dev, "could not prepare SSP/SPI bus clock\n");
		goto  err_clk_prep;
	}

	status = clk_enable(pl022->clk);
	if (status) {
		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
		goto err_no_clk_en;
	}

	/* Disable SSP */
	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
	       SSP_CR1(pl022->virtbase));
	load_ssp_default_config(pl022);

	status = request_irq(adev->irq[0], pl022_interrupt_handler, 0, "pl022",
			     pl022);
	if (status < 0) {
		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
		goto err_no_irq;
	}

	/* Get DMA channels */
	if (platform_info->enable_dma) {
		status = pl022_dma_probe(pl022);
		if (status != 0)
			platform_info->enable_dma = 0;
	}

	/* Initialize and start queue */
	status = init_queue(pl022);
	if (status != 0) {
		dev_err(&adev->dev, "probe - problem initializing queue\n");
		goto err_init_queue;
	}
	status = start_queue(pl022);
	if (status != 0) {
		dev_err(&adev->dev, "probe - problem starting queue\n");
		goto err_start_queue;
	}
	/* Register with the SPI framework */
	amba_set_drvdata(adev, pl022);
	status = spi_register_master(master);
	if (status != 0) {
		dev_err(&adev->dev,
			"probe - problem registering spi master\n");
		goto err_spi_register;
	}
	dev_dbg(dev, "probe succeeded\n");

	/* let runtime pm put suspend */
	if (platform_info->autosuspend_delay > 0) {
		dev_info(&adev->dev,
			"will use autosuspend for runtime pm, delay %dms\n",
			platform_info->autosuspend_delay);
		pm_runtime_set_autosuspend_delay(dev,
			platform_info->autosuspend_delay);
		pm_runtime_use_autosuspend(dev);
		pm_runtime_put_autosuspend(dev);
	} else {
		pm_runtime_put(dev);
	}
	return 0;

 err_spi_register:
 err_start_queue:
 err_init_queue:
	destroy_queue(pl022);
	if (platform_info->enable_dma)
		pl022_dma_remove(pl022);

	free_irq(adev->irq[0], pl022);
 err_no_irq:
	clk_disable(pl022->clk);
 err_no_clk_en:
	clk_unprepare(pl022->clk);
 err_clk_prep:
	clk_put(pl022->clk);
 err_no_clk:
	iounmap(pl022->virtbase);
 err_no_ioremap:
	amba_release_regions(adev);
 err_no_ioregion:
	spi_master_put(master);
 err_no_master:
 err_no_pdata:
	return status;
}

static int __devexit
pl022_remove(struct amba_device *adev)
{
	struct pl022 *pl022 = amba_get_drvdata(adev);

	if (!pl022)
		return 0;

	/*
	 * undo pm_runtime_put() in probe.  I assume that we're not
	 * accessing the primecell here.
	 */
	pm_runtime_get_noresume(&adev->dev);

	/* Remove the queue */
	if (destroy_queue(pl022) != 0)
		dev_err(&adev->dev, "queue remove failed\n");
	load_ssp_default_config(pl022);
	if (pl022->master_info->enable_dma)
		pl022_dma_remove(pl022);

	free_irq(adev->irq[0], pl022);
	clk_disable(pl022->clk);
	clk_unprepare(pl022->clk);
	clk_put(pl022->clk);
	iounmap(pl022->virtbase);
	amba_release_regions(adev);
	tasklet_disable(&pl022->pump_transfers);
	spi_unregister_master(pl022->master);
	spi_master_put(pl022->master);
	amba_set_drvdata(adev, NULL);
	return 0;
}

#ifdef CONFIG_SUSPEND
static int pl022_suspend(struct device *dev)
{
	struct pl022 *pl022 = dev_get_drvdata(dev);
	int status = 0;

	status = stop_queue(pl022);
	if (status) {
		dev_warn(dev, "suspend cannot stop queue\n");
		return status;
	}

	dev_dbg(dev, "suspended\n");
	return 0;
}

static int pl022_resume(struct device *dev)
{
	struct pl022 *pl022 = dev_get_drvdata(dev);
	int status = 0;

	/* Start the queue running */
	status = start_queue(pl022);
	if (status)
		dev_err(dev, "problem starting queue (%d)\n", status);
	else
		dev_dbg(dev, "resumed\n");

	return status;
}
#endif	/* CONFIG_PM */

#ifdef CONFIG_PM_RUNTIME
static int pl022_runtime_suspend(struct device *dev)
{
	struct pl022 *pl022 = dev_get_drvdata(dev);

	clk_disable(pl022->clk);
	amba_vcore_disable(pl022->adev);

	return 0;
}

static int pl022_runtime_resume(struct device *dev)
{
	struct pl022 *pl022 = dev_get_drvdata(dev);

	amba_vcore_enable(pl022->adev);
	clk_enable(pl022->clk);

	return 0;
}
#endif

static const struct dev_pm_ops pl022_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
};

static struct vendor_data vendor_arm = {
	.fifodepth = 8,
	.max_bpw = 16,
	.unidir = false,
	.extended_cr = false,
	.pl023 = false,
	.loopback = true,
};

static struct vendor_data vendor_st = {
	.fifodepth = 32,
	.max_bpw = 32,
	.unidir = false,
	.extended_cr = true,
	.pl023 = false,
	.loopback = true,
};

static struct vendor_data vendor_st_pl023 = {
	.fifodepth = 32,
	.max_bpw = 32,
	.unidir = false,
	.extended_cr = true,
	.pl023 = true,
	.loopback = false,
};

static struct vendor_data vendor_db5500_pl023 = {
	.fifodepth = 32,
	.max_bpw = 32,
	.unidir = false,
	.extended_cr = true,
	.pl023 = true,
	.loopback = true,
};

static struct amba_id pl022_ids[] = {
	{
		/*
		 * ARM PL022 variant, this has a 16bit wide
		 * and 8 locations deep TX/RX FIFO
		 */
		.id	= 0x00041022,
		.mask	= 0x000fffff,
		.data	= &vendor_arm,
	},
	{
		/*
		 * ST Micro derivative, this has 32bit wide
		 * and 32 locations deep TX/RX FIFO
		 */
		.id	= 0x01080022,
		.mask	= 0xffffffff,
		.data	= &vendor_st,
	},
	{
		/*
		 * ST-Ericsson derivative "PL023" (this is not
		 * an official ARM number), this is a PL022 SSP block
		 * stripped to SPI mode only, it has 32bit wide
		 * and 32 locations deep TX/RX FIFO but no extended
		 * CR0/CR1 register
		 */
		.id	= 0x00080023,
		.mask	= 0xffffffff,
		.data	= &vendor_st_pl023,
	},
	{
		.id	= 0x10080023,
		.mask	= 0xffffffff,
		.data	= &vendor_db5500_pl023,
	},
	{ 0, 0 },
};

MODULE_DEVICE_TABLE(amba, pl022_ids);

static struct amba_driver pl022_driver = {
	.drv = {
		.name	= "ssp-pl022",
		.pm	= &pl022_dev_pm_ops,
	},
	.id_table	= pl022_ids,
	.probe		= pl022_probe,
	.remove		= __devexit_p(pl022_remove),
};

static int __init pl022_init(void)
{
	return amba_driver_register(&pl022_driver);
}
subsys_initcall(pl022_init);

static void __exit pl022_exit(void)
{
	amba_driver_unregister(&pl022_driver);
}
module_exit(pl022_exit);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("PL022 SSP Controller Driver");
MODULE_LICENSE("GPL");