summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/omap-serial.c
blob: 0121486ac4fafbf3bf162ef3744772255e8380e5 (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
/*
 * Driver for OMAP-UART controller.
 * Based on drivers/serial/8250.c
 *
 * Copyright (C) 2010 Texas Instruments.
 *
 * Authors:
 *	Govindraj R	<govindraj.raja@ti.com>
 *	Thara Gopinath	<thara@ti.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.
 *
 * Note: This driver is made separate from 8250 driver as we cannot
 * over load 8250 driver with omap platform specific configuration for
 * features like DMA, it makes easier to implement features like DMA and
 * hardware flow control and software flow control configuration with
 * this driver as required for the omap-platform.
 */

#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/serial_reg.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/serial_core.h>
#include <linux/irq.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>

#include <plat/dma.h>
#include <plat/dmtimer.h>
#include <plat/omap-serial.h>

#define DEFAULT_CLK_SPEED 48000000 /* 48Mhz*/

/* SCR register bitmasks */
#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)

/* FCR register bitmasks */
#define OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT		6
#define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)

static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];

/* Forward declaration of functions */
static void uart_tx_dma_callback(int lch, u16 ch_status, void *data);
static void serial_omap_rxdma_poll(unsigned long uart_no);
static int serial_omap_start_rxdma(struct uart_omap_port *up);
static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);

static struct workqueue_struct *serial_omap_uart_wq;

static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
{
	offset <<= up->port.regshift;
	return readw(up->port.membase + offset);
}

static inline void serial_out(struct uart_omap_port *up, int offset, int value)
{
	offset <<= up->port.regshift;
	writew(value, up->port.membase + offset);
}

static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
{
	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
	serial_out(up, UART_FCR, 0);
}

/*
 * serial_omap_get_divisor - calculate divisor value
 * @port: uart port info
 * @baud: baudrate for which divisor needs to be calculated.
 *
 * We have written our own function to get the divisor so as to support
 * 13x mode. 3Mbps Baudrate as an different divisor.
 * Reference OMAP TRM Chapter 17:
 * Table 17-1. UART Mode Baud Rates, Divisor Values, and Error Rates
 * referring to oversampling - divisor value
 * baudrate 460,800 to 3,686,400 all have divisor 13
 * except 3,000,000 which has divisor value 16
 */
static unsigned int
serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
{
	unsigned int divisor;

	if (baud > OMAP_MODE13X_SPEED && baud != 3000000)
		divisor = 13;
	else
		divisor = 16;
	return port->uartclk/(baud * divisor);
}

static void serial_omap_stop_rxdma(struct uart_omap_port *up)
{
	if (up->uart_dma.rx_dma_used) {
		del_timer(&up->uart_dma.rx_timer);
		omap_stop_dma(up->uart_dma.rx_dma_channel);
		omap_free_dma(up->uart_dma.rx_dma_channel);
		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
		up->uart_dma.rx_dma_used = false;
		pm_runtime_mark_last_busy(&up->pdev->dev);
		pm_runtime_put_autosuspend(&up->pdev->dev);
	}
}

static void serial_omap_enable_ms(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);

	pm_runtime_get_sync(&up->pdev->dev);
	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
	pm_runtime_put(&up->pdev->dev);
}

static void serial_omap_stop_tx(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	struct omap_uart_port_info *pdata = up->pdev->dev.platform_data;

	if (up->use_dma &&
		up->uart_dma.tx_dma_channel != OMAP_UART_DMA_CH_FREE) {
		/*
		 * Check if dma is still active. If yes do nothing,
		 * return. Else stop dma
		 */
		if (omap_get_dma_active_status(up->uart_dma.tx_dma_channel))
			return;
		omap_stop_dma(up->uart_dma.tx_dma_channel);
		omap_free_dma(up->uart_dma.tx_dma_channel);
		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
		pm_runtime_mark_last_busy(&up->pdev->dev);
		pm_runtime_put_autosuspend(&up->pdev->dev);
	}

	pm_runtime_get_sync(&up->pdev->dev);
	if (up->ier & UART_IER_THRI) {
		up->ier &= ~UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
	}

	if (!up->use_dma && pdata && pdata->set_forceidle)
		pdata->set_forceidle(up->pdev);

	pm_runtime_mark_last_busy(&up->pdev->dev);
	pm_runtime_put_autosuspend(&up->pdev->dev);
}

static void serial_omap_stop_rx(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	pm_runtime_get_sync(&up->pdev->dev);
	if (up->use_dma)
		serial_omap_stop_rxdma(up);
	up->ier &= ~UART_IER_RLSI;
	up->port.read_status_mask &= ~UART_LSR_DR;
	serial_out(up, UART_IER, up->ier);
	pm_runtime_mark_last_busy(&up->pdev->dev);
	pm_runtime_put_autosuspend(&up->pdev->dev);
}

static inline void receive_chars(struct uart_omap_port *up,
		unsigned int *status)
{
	struct tty_struct *tty = up->port.state->port.tty;
	unsigned int flag, lsr = *status;
	unsigned char ch = 0;
	int max_count = 256;

	do {
		if (likely(lsr & UART_LSR_DR))
			ch = serial_in(up, UART_RX);
		flag = TTY_NORMAL;
		up->port.icount.rx++;

		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
			/*
			 * For statistics only
			 */
			if (lsr & UART_LSR_BI) {
				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
				up->port.icount.brk++;
				/*
				 * We do the SysRQ and SAK checking
				 * here because otherwise the break
				 * may get masked by ignore_status_mask
				 * or read_status_mask.
				 */
				if (uart_handle_break(&up->port))
					goto ignore_char;
			} else if (lsr & UART_LSR_PE) {
				up->port.icount.parity++;
			} else if (lsr & UART_LSR_FE) {
				up->port.icount.frame++;
			}

			if (lsr & UART_LSR_OE)
				up->port.icount.overrun++;

			/*
			 * Mask off conditions which should be ignored.
			 */
			lsr &= up->port.read_status_mask;

#ifdef CONFIG_SERIAL_OMAP_CONSOLE
			if (up->port.line == up->port.cons->index) {
				/* Recover the break flag from console xmit */
				lsr |= up->lsr_break_flag;
			}
#endif
			if (lsr & UART_LSR_BI)
				flag = TTY_BREAK;
			else if (lsr & UART_LSR_PE)
				flag = TTY_PARITY;
			else if (lsr & UART_LSR_FE)
				flag = TTY_FRAME;
		}

		if (uart_handle_sysrq_char(&up->port, ch))
			goto ignore_char;
		uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
ignore_char:
		lsr = serial_in(up, UART_LSR);
	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&up->port.lock);
}

static void transmit_chars(struct uart_omap_port *up)
{
	struct circ_buf *xmit = &up->port.state->xmit;
	int count;

	if (up->port.x_char) {
		serial_out(up, UART_TX, up->port.x_char);
		up->port.icount.tx++;
		up->port.x_char = 0;
		return;
	}
	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
		serial_omap_stop_tx(&up->port);
		return;
	}
	count = up->port.fifosize / 4;
	do {
		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		up->port.icount.tx++;
		if (uart_circ_empty(xmit))
			break;
	} while (--count > 0);

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(&up->port);

	if (uart_circ_empty(xmit))
		serial_omap_stop_tx(&up->port);
}

static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
{
	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
	}
}

static void serial_omap_start_tx(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	struct omap_uart_port_info *pdata = up->pdev->dev.platform_data;
	struct circ_buf *xmit;
	unsigned int start;
	int ret = 0;

	if (!up->use_dma) {
		pm_runtime_get_sync(&up->pdev->dev);
		serial_omap_enable_ier_thri(up);
		if (pdata && pdata->set_noidle)
			pdata->set_noidle(up->pdev);
		pm_runtime_mark_last_busy(&up->pdev->dev);
		pm_runtime_put_autosuspend(&up->pdev->dev);
		return;
	}

	if (up->uart_dma.tx_dma_used)
		return;

	xmit = &up->port.state->xmit;

	if (up->uart_dma.tx_dma_channel == OMAP_UART_DMA_CH_FREE) {
		pm_runtime_get_sync(&up->pdev->dev);
		ret = omap_request_dma(up->uart_dma.uart_dma_tx,
				"UART Tx DMA",
				(void *)uart_tx_dma_callback, up,
				&(up->uart_dma.tx_dma_channel));

		if (ret < 0) {
			serial_omap_enable_ier_thri(up);
			return;
		}
	}
	spin_lock(&(up->uart_dma.tx_lock));
	up->uart_dma.tx_dma_used = true;
	spin_unlock(&(up->uart_dma.tx_lock));

	start = up->uart_dma.tx_buf_dma_phys +
				(xmit->tail & (UART_XMIT_SIZE - 1));

	up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
	/*
	 * It is a circular buffer. See if the buffer has wounded back.
	 * If yes it will have to be transferred in two separate dma
	 * transfers
	 */
	if (start + up->uart_dma.tx_buf_size >=
			up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
		up->uart_dma.tx_buf_size =
			(up->uart_dma.tx_buf_dma_phys +
			UART_XMIT_SIZE) - start;

	omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
				OMAP_DMA_AMODE_CONSTANT,
				up->uart_dma.uart_base, 0, 0);
	omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
				OMAP_DMA_AMODE_POST_INC, start, 0, 0);
	omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
				OMAP_DMA_DATA_TYPE_S8,
				up->uart_dma.tx_buf_size, 1,
				OMAP_DMA_SYNC_ELEMENT,
				up->uart_dma.uart_dma_tx, 0);
	/* FIXME: Cache maintenance needed here? */
	omap_start_dma(up->uart_dma.tx_dma_channel);
}

static unsigned int check_modem_status(struct uart_omap_port *up)
{
	unsigned int status;

	status = serial_in(up, UART_MSR);
	status |= up->msr_saved_flags;
	up->msr_saved_flags = 0;
	if ((status & UART_MSR_ANY_DELTA) == 0)
		return status;

	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
	    up->port.state != NULL) {
		if (status & UART_MSR_TERI)
			up->port.icount.rng++;
		if (status & UART_MSR_DDSR)
			up->port.icount.dsr++;
		if (status & UART_MSR_DDCD)
			uart_handle_dcd_change
				(&up->port, status & UART_MSR_DCD);
		if (status & UART_MSR_DCTS)
			uart_handle_cts_change
				(&up->port, status & UART_MSR_CTS);
		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
	}

	return status;
}

/**
 * serial_omap_irq() - This handles the interrupt from one port
 * @irq: uart port irq number
 * @dev_id: uart port info
 */
static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
{
	struct uart_omap_port *up = dev_id;
	unsigned int iir, lsr;
	unsigned long flags;

	pm_runtime_get_sync(&up->pdev->dev);
	iir = serial_in(up, UART_IIR);
	if (iir & UART_IIR_NO_INT) {
		pm_runtime_mark_last_busy(&up->pdev->dev);
		pm_runtime_put_autosuspend(&up->pdev->dev);
		return IRQ_NONE;
	}

	spin_lock_irqsave(&up->port.lock, flags);
	lsr = serial_in(up, UART_LSR);
	if (iir & UART_IIR_RLSI) {
		if (!up->use_dma) {
			if (lsr & UART_LSR_DR)
				receive_chars(up, &lsr);
		} else {
			up->ier &= ~(UART_IER_RDI | UART_IER_RLSI);
			serial_out(up, UART_IER, up->ier);
			if ((serial_omap_start_rxdma(up) != 0) &&
					(lsr & UART_LSR_DR))
				receive_chars(up, &lsr);
		}
	}

	check_modem_status(up);
	if ((lsr & UART_LSR_THRE) && (iir & UART_IIR_THRI))
		transmit_chars(up);

	spin_unlock_irqrestore(&up->port.lock, flags);
	pm_runtime_mark_last_busy(&up->pdev->dev);
	pm_runtime_put_autosuspend(&up->pdev->dev);

	up->port_activity = jiffies;
	return IRQ_HANDLED;
}

static unsigned int serial_omap_tx_empty(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned long flags = 0;
	unsigned int ret = 0;

	pm_runtime_get_sync(&up->pdev->dev);
	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
	spin_lock_irqsave(&up->port.lock, flags);
	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
	spin_unlock_irqrestore(&up->port.lock, flags);
	pm_runtime_put(&up->pdev->dev);
	return ret;
}

static unsigned int serial_omap_get_mctrl(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned int status;
	unsigned int ret = 0;

	pm_runtime_get_sync(&up->pdev->dev);
	status = check_modem_status(up);
	pm_runtime_put(&up->pdev->dev);

	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);

	if (status & UART_MSR_DCD)
		ret |= TIOCM_CAR;
	if (status & UART_MSR_RI)
		ret |= TIOCM_RNG;
	if (status & UART_MSR_DSR)
		ret |= TIOCM_DSR;
	if (status & UART_MSR_CTS)
		ret |= TIOCM_CTS;
	return ret;
}

static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned char mcr = 0;

	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
	if (mctrl & TIOCM_RTS)
		mcr |= UART_MCR_RTS;
	if (mctrl & TIOCM_DTR)
		mcr |= UART_MCR_DTR;
	if (mctrl & TIOCM_OUT1)
		mcr |= UART_MCR_OUT1;
	if (mctrl & TIOCM_OUT2)
		mcr |= UART_MCR_OUT2;
	if (mctrl & TIOCM_LOOP)
		mcr |= UART_MCR_LOOP;

	pm_runtime_get_sync(&up->pdev->dev);
	up->mcr = serial_in(up, UART_MCR);
	up->mcr |= mcr;
	serial_out(up, UART_MCR, up->mcr);
	pm_runtime_put(&up->pdev->dev);
}

static void serial_omap_break_ctl(struct uart_port *port, int break_state)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned long flags = 0;

	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
	pm_runtime_get_sync(&up->pdev->dev);
	spin_lock_irqsave(&up->port.lock, flags);
	if (break_state == -1)
		up->lcr |= UART_LCR_SBC;
	else
		up->lcr &= ~UART_LCR_SBC;
	serial_out(up, UART_LCR, up->lcr);
	spin_unlock_irqrestore(&up->port.lock, flags);
	pm_runtime_put(&up->pdev->dev);
}

static int serial_omap_startup(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned long flags = 0;
	int retval;

	/*
	 * Allocate the IRQ
	 */
	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
				up->name, up);
	if (retval)
		return retval;

	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);

	pm_runtime_get_sync(&up->pdev->dev);
	/*
	 * Clear the FIFO buffers and disable them.
	 * (they will be reenabled in set_termios())
	 */
	serial_omap_clear_fifos(up);
	/* For Hardware flow control */
	serial_out(up, UART_MCR, UART_MCR_RTS);

	/*
	 * Clear the interrupt registers.
	 */
	(void) serial_in(up, UART_LSR);
	if (serial_in(up, UART_LSR) & UART_LSR_DR)
		(void) serial_in(up, UART_RX);
	(void) serial_in(up, UART_IIR);
	(void) serial_in(up, UART_MSR);

	/*
	 * Now, initialize the UART
	 */
	serial_out(up, UART_LCR, UART_LCR_WLEN8);
	spin_lock_irqsave(&up->port.lock, flags);
	/*
	 * Most PC uarts need OUT2 raised to enable interrupts.
	 */
	up->port.mctrl |= TIOCM_OUT2;
	serial_omap_set_mctrl(&up->port, up->port.mctrl);
	spin_unlock_irqrestore(&up->port.lock, flags);

	up->msr_saved_flags = 0;
	if (up->use_dma) {
		free_page((unsigned long)up->port.state->xmit.buf);
		up->port.state->xmit.buf = dma_alloc_coherent(NULL,
			UART_XMIT_SIZE,
			(dma_addr_t *)&(up->uart_dma.tx_buf_dma_phys),
			0);
		init_timer(&(up->uart_dma.rx_timer));
		up->uart_dma.rx_timer.function = serial_omap_rxdma_poll;
		up->uart_dma.rx_timer.data = up->port.line;
		/* Currently the buffer size is 4KB. Can increase it */
		up->uart_dma.rx_buf = dma_alloc_coherent(NULL,
			up->uart_dma.rx_buf_size,
			(dma_addr_t *)&(up->uart_dma.rx_buf_dma_phys), 0);
	}
	/*
	 * Finally, enable interrupts. Note: Modem status interrupts
	 * are set via set_termios(), which will be occurring imminently
	 * anyway, so we don't enable them here.
	 */
	up->ier = UART_IER_RLSI | UART_IER_RDI;
	serial_out(up, UART_IER, up->ier);

	/* Enable module level wake up */
	serial_out(up, UART_OMAP_WER, OMAP_UART_WER_MOD_WKUP);

	pm_runtime_mark_last_busy(&up->pdev->dev);
	pm_runtime_put_autosuspend(&up->pdev->dev);
	up->port_activity = jiffies;
	return 0;
}

static void serial_omap_shutdown(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned long flags = 0;

	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);

	pm_runtime_get_sync(&up->pdev->dev);
	/*
	 * Disable interrupts from this port
	 */
	up->ier = 0;
	serial_out(up, UART_IER, 0);

	spin_lock_irqsave(&up->port.lock, flags);
	up->port.mctrl &= ~TIOCM_OUT2;
	serial_omap_set_mctrl(&up->port, up->port.mctrl);
	spin_unlock_irqrestore(&up->port.lock, flags);

	/*
	 * Disable break condition and FIFOs
	 */
	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
	serial_omap_clear_fifos(up);

	/*
	 * Read data port to reset things, and then free the irq
	 */
	if (serial_in(up, UART_LSR) & UART_LSR_DR)
		(void) serial_in(up, UART_RX);
	if (up->use_dma) {
		dma_free_coherent(up->port.dev,
			UART_XMIT_SIZE,	up->port.state->xmit.buf,
			up->uart_dma.tx_buf_dma_phys);
		up->port.state->xmit.buf = NULL;
		serial_omap_stop_rx(port);
		dma_free_coherent(up->port.dev,
			up->uart_dma.rx_buf_size, up->uart_dma.rx_buf,
			up->uart_dma.rx_buf_dma_phys);
		up->uart_dma.rx_buf = NULL;
	}

	pm_runtime_put(&up->pdev->dev);
	free_irq(up->port.irq, up);
}

static inline void
serial_omap_configure_xonxoff
		(struct uart_omap_port *up, struct ktermios *termios)
{
	up->lcr = serial_in(up, UART_LCR);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	up->efr = serial_in(up, UART_EFR);
	serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);

	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);

	/* clear SW control mode bits */
	up->efr &= OMAP_UART_SW_CLR;

	/*
	 * IXON Flag:
	 * Enable XON/XOFF flow control on output.
	 * Transmit XON1, XOFF1
	 */
	if (termios->c_iflag & IXON)
		up->efr |= OMAP_UART_SW_TX;

	/*
	 * IXOFF Flag:
	 * Enable XON/XOFF flow control on input.
	 * Receiver compares XON1, XOFF1.
	 */
	if (termios->c_iflag & IXOFF)
		up->efr |= OMAP_UART_SW_RX;

	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);

	up->mcr = serial_in(up, UART_MCR);

	/*
	 * IXANY Flag:
	 * Enable any character to restart output.
	 * Operation resumes after receiving any
	 * character after recognition of the XOFF character
	 */
	if (termios->c_iflag & IXANY)
		up->mcr |= UART_MCR_XONANY;

	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
	/* Enable special char function UARTi.EFR_REG[5] and
	 * load the new software flow control mode IXON or IXOFF
	 * and restore the UARTi.EFR_REG[4] ENHANCED_EN value.
	 */
	serial_out(up, UART_EFR, up->efr | UART_EFR_SCD);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);

	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
	serial_out(up, UART_LCR, up->lcr);
}

static void serial_omap_uart_qos_work(struct work_struct *work)
{
	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
						qos_work);

	pm_qos_update_request(&up->pm_qos_request, up->latency);
}

static void
serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
			struct ktermios *old)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned char cval = 0;
	unsigned char efr = 0;
	unsigned long flags = 0;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
		cval = UART_LCR_WLEN5;
		break;
	case CS6:
		cval = UART_LCR_WLEN6;
		break;
	case CS7:
		cval = UART_LCR_WLEN7;
		break;
	default:
	case CS8:
		cval = UART_LCR_WLEN8;
		break;
	}

	if (termios->c_cflag & CSTOPB)
		cval |= UART_LCR_STOP;
	if (termios->c_cflag & PARENB)
		cval |= UART_LCR_PARITY;
	if (!(termios->c_cflag & PARODD))
		cval |= UART_LCR_EPAR;

	/*
	 * Ask the core to calculate the divisor for us.
	 */

	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
	quot = serial_omap_get_divisor(port, baud);

	/* calculate wakeup latency constraint */
	up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
	up->latency = up->calc_latency;
	schedule_work(&up->qos_work);

	up->dll = quot & 0xff;
	up->dlh = quot >> 8;
	up->mdr1 = UART_OMAP_MDR1_DISABLE;

	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
			UART_FCR_ENABLE_FIFO;
	if (up->use_dma)
		up->fcr |= UART_FCR_DMA_SELECT;

	/*
	 * Ok, we're now changing the port state. Do it with
	 * interrupts disabled.
	 */
	pm_runtime_get_sync(&up->pdev->dev);
	spin_lock_irqsave(&up->port.lock, flags);

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
	if (termios->c_iflag & INPCK)
		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (termios->c_iflag & (BRKINT | PARMRK))
		up->port.read_status_mask |= UART_LSR_BI;

	/*
	 * Characters to ignore
	 */
	up->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
	if (termios->c_iflag & IGNBRK) {
		up->port.ignore_status_mask |= UART_LSR_BI;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			up->port.ignore_status_mask |= UART_LSR_OE;
	}

	/*
	 * ignore all characters if CREAD is not set
	 */
	if ((termios->c_cflag & CREAD) == 0)
		up->port.ignore_status_mask |= UART_LSR_DR;

	/*
	 * Modem status interrupts
	 */
	up->ier &= ~UART_IER_MSI;
	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
		up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
	serial_out(up, UART_LCR, cval);		/* reset DLAB */
	up->lcr = cval;
	up->scr = OMAP_UART_SCR_TX_EMPTY;

	/* FIFOs and DMA Settings */

	/* FCR can be changed only when the
	 * baud clock is not running
	 * DLL_REG and DLH_REG set to 0.
	 */
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
	serial_out(up, UART_DLL, 0);
	serial_out(up, UART_DLM, 0);
	serial_out(up, UART_LCR, 0);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	up->efr = serial_in(up, UART_EFR);
	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
	up->mcr = serial_in(up, UART_MCR);
	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
	/* FIFO ENABLE, DMA MODE */

	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;

	if (up->use_dma) {
		serial_out(up, UART_TI752_TLR, 0);
		up->scr |= UART_FCR_TRIGGER_4;
	} else {
		/* Set receive FIFO threshold to 1 byte */
		up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
		up->fcr |= (0x1 << OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT);
	}

	serial_out(up, UART_FCR, up->fcr);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	serial_out(up, UART_OMAP_SCR, up->scr);

	serial_out(up, UART_EFR, up->efr);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
	serial_out(up, UART_MCR, up->mcr);

	/* Protocol, Baud Rate, and Interrupt Settings */

	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
		serial_omap_mdr1_errataset(up, up->mdr1);
	else
		serial_out(up, UART_OMAP_MDR1, up->mdr1);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	up->efr = serial_in(up, UART_EFR);
	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);

	serial_out(up, UART_LCR, 0);
	serial_out(up, UART_IER, 0);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */

	serial_out(up, UART_LCR, 0);
	serial_out(up, UART_IER, up->ier);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	serial_out(up, UART_EFR, up->efr);
	serial_out(up, UART_LCR, cval);

	if (baud > 230400 && baud != 3000000)
		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
	else
		up->mdr1 = UART_OMAP_MDR1_16X_MODE;

	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
		serial_omap_mdr1_errataset(up, up->mdr1);
	else
		serial_out(up, UART_OMAP_MDR1, up->mdr1);

	/* Hardware Flow Control Configuration */

	if (termios->c_cflag & CRTSCTS) {
		efr |= (UART_EFR_CTS | UART_EFR_RTS);
		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);

		up->mcr = serial_in(up, UART_MCR);
		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);

		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
		up->efr = serial_in(up, UART_EFR);
		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);

		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
		serial_out(up, UART_EFR, efr); /* Enable AUTORTS and AUTOCTS */
		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
		serial_out(up, UART_LCR, cval);
	}

	serial_omap_set_mctrl(&up->port, up->port.mctrl);
	/* Software Flow Control Configuration */
	serial_omap_configure_xonxoff(up, termios);

	spin_unlock_irqrestore(&up->port.lock, flags);
	pm_runtime_put(&up->pdev->dev);
	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
}

static void
serial_omap_pm(struct uart_port *port, unsigned int state,
	       unsigned int oldstate)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned char efr;

	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);

	pm_runtime_get_sync(&up->pdev->dev);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	efr = serial_in(up, UART_EFR);
	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
	serial_out(up, UART_LCR, 0);

	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	serial_out(up, UART_EFR, efr);
	serial_out(up, UART_LCR, 0);

	if (!device_may_wakeup(&up->pdev->dev)) {
		if (!state)
			pm_runtime_forbid(&up->pdev->dev);
		else
			pm_runtime_allow(&up->pdev->dev);
	}

	pm_runtime_put(&up->pdev->dev);
}

static void serial_omap_release_port(struct uart_port *port)
{
	dev_dbg(port->dev, "serial_omap_release_port+\n");
}

static int serial_omap_request_port(struct uart_port *port)
{
	dev_dbg(port->dev, "serial_omap_request_port+\n");
	return 0;
}

static void serial_omap_config_port(struct uart_port *port, int flags)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
							up->port.line);
	up->port.type = PORT_OMAP;
}

static int
serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	/* we don't want the core code to modify any port params */
	dev_dbg(port->dev, "serial_omap_verify_port+\n");
	return -EINVAL;
}

static const char *
serial_omap_type(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
	return up->name;
}

#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

static inline void wait_for_xmitr(struct uart_omap_port *up)
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
	do {
		status = serial_in(up, UART_LSR);

		if (status & UART_LSR_BI)
			up->lsr_break_flag = UART_LSR_BI;

		if (--tmout == 0)
			break;
		udelay(1);
	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
		tmout = 1000000;
		for (tmout = 1000000; tmout; tmout--) {
			unsigned int msr = serial_in(up, UART_MSR);

			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
			if (msr & UART_MSR_CTS)
				break;

			udelay(1);
		}
	}
}

#ifdef CONFIG_CONSOLE_POLL

static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	pm_runtime_get_sync(&up->pdev->dev);
	wait_for_xmitr(up);
	serial_out(up, UART_TX, ch);
	pm_runtime_put(&up->pdev->dev);
}

static int serial_omap_poll_get_char(struct uart_port *port)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;
	unsigned int status;

	pm_runtime_get_sync(&up->pdev->dev);
	status = serial_in(up, UART_LSR);
	if (!(status & UART_LSR_DR))
		return NO_POLL_CHAR;

	status = serial_in(up, UART_RX);
	pm_runtime_put(&up->pdev->dev);
	return status;
}

#endif /* CONFIG_CONSOLE_POLL */

#ifdef CONFIG_SERIAL_OMAP_CONSOLE

static struct uart_omap_port *serial_omap_console_ports[4];

static struct uart_driver serial_omap_reg;

static void serial_omap_console_putchar(struct uart_port *port, int ch)
{
	struct uart_omap_port *up = (struct uart_omap_port *)port;

	wait_for_xmitr(up);
	serial_out(up, UART_TX, ch);
}

static void
serial_omap_console_write(struct console *co, const char *s,
		unsigned int count)
{
	struct uart_omap_port *up = serial_omap_console_ports[co->index];
	unsigned long flags;
	unsigned int ier;
	int locked = 1;

	pm_runtime_get_sync(&up->pdev->dev);

	local_irq_save(flags);
	if (up->port.sysrq)
		locked = 0;
	else if (oops_in_progress)
		locked = spin_trylock(&up->port.lock);
	else
		spin_lock(&up->port.lock);

	/*
	 * First save the IER then disable the interrupts
	 */
	ier = serial_in(up, UART_IER);
	serial_out(up, UART_IER, 0);

	uart_console_write(&up->port, s, count, serial_omap_console_putchar);

	/*
	 * Finally, wait for transmitter to become empty
	 * and restore the IER
	 */
	wait_for_xmitr(up);
	serial_out(up, UART_IER, ier);
	/*
	 * The receive handling will happen properly because the
	 * receive ready bit will still be set; it is not cleared
	 * on read.  However, modem control will not, we must
	 * call it if we have saved something in the saved flags
	 * while processing with interrupts off.
	 */
	if (up->msr_saved_flags)
		check_modem_status(up);

	pm_runtime_mark_last_busy(&up->pdev->dev);
	pm_runtime_put_autosuspend(&up->pdev->dev);
	if (locked)
		spin_unlock(&up->port.lock);
	local_irq_restore(flags);
}

static int __init
serial_omap_console_setup(struct console *co, char *options)
{
	struct uart_omap_port *up;
	int baud = 115200;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	if (serial_omap_console_ports[co->index] == NULL)
		return -ENODEV;
	up = serial_omap_console_ports[co->index];

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);

	return uart_set_options(&up->port, co, baud, parity, bits, flow);
}

static struct console serial_omap_console = {
	.name		= OMAP_SERIAL_NAME,
	.write		= serial_omap_console_write,
	.device		= uart_console_device,
	.setup		= serial_omap_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &serial_omap_reg,
};

static void serial_omap_add_console_port(struct uart_omap_port *up)
{
	serial_omap_console_ports[up->port.line] = up;
}

#define OMAP_CONSOLE	(&serial_omap_console)

#else

#define OMAP_CONSOLE	NULL

static inline void serial_omap_add_console_port(struct uart_omap_port *up)
{}

#endif

static struct uart_ops serial_omap_pops = {
	.tx_empty	= serial_omap_tx_empty,
	.set_mctrl	= serial_omap_set_mctrl,
	.get_mctrl	= serial_omap_get_mctrl,
	.stop_tx	= serial_omap_stop_tx,
	.start_tx	= serial_omap_start_tx,
	.stop_rx	= serial_omap_stop_rx,
	.enable_ms	= serial_omap_enable_ms,
	.break_ctl	= serial_omap_break_ctl,
	.startup	= serial_omap_startup,
	.shutdown	= serial_omap_shutdown,
	.set_termios	= serial_omap_set_termios,
	.pm		= serial_omap_pm,
	.type		= serial_omap_type,
	.release_port	= serial_omap_release_port,
	.request_port	= serial_omap_request_port,
	.config_port	= serial_omap_config_port,
	.verify_port	= serial_omap_verify_port,
#ifdef CONFIG_CONSOLE_POLL
	.poll_put_char  = serial_omap_poll_put_char,
	.poll_get_char  = serial_omap_poll_get_char,
#endif
};

static struct uart_driver serial_omap_reg = {
	.owner		= THIS_MODULE,
	.driver_name	= "OMAP-SERIAL",
	.dev_name	= OMAP_SERIAL_NAME,
	.nr		= OMAP_MAX_HSUART_PORTS,
	.cons		= OMAP_CONSOLE,
};

#ifdef CONFIG_PM_SLEEP
static int serial_omap_suspend(struct device *dev)
{
	struct uart_omap_port *up = dev_get_drvdata(dev);

	if (up) {
		uart_suspend_port(&serial_omap_reg, &up->port);
		flush_work_sync(&up->qos_work);
	}

	return 0;
}

static int serial_omap_resume(struct device *dev)
{
	struct uart_omap_port *up = dev_get_drvdata(dev);

	if (up)
		uart_resume_port(&serial_omap_reg, &up->port);
	return 0;
}
#endif

static void serial_omap_rxdma_poll(unsigned long uart_no)
{
	struct uart_omap_port *up = ui[uart_no];
	unsigned int curr_dma_pos, curr_transmitted_size;
	int ret = 0;

	curr_dma_pos = omap_get_dma_dst_pos(up->uart_dma.rx_dma_channel);
	if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) ||
			     (curr_dma_pos == 0)) {
		if (jiffies_to_msecs(jiffies - up->port_activity) <
						up->uart_dma.rx_timeout) {
			mod_timer(&up->uart_dma.rx_timer, jiffies +
				usecs_to_jiffies(up->uart_dma.rx_poll_rate));
		} else {
			serial_omap_stop_rxdma(up);
			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
			serial_out(up, UART_IER, up->ier);
		}
		return;
	}

	curr_transmitted_size = curr_dma_pos -
					up->uart_dma.prev_rx_dma_pos;
	up->port.icount.rx += curr_transmitted_size;
	tty_insert_flip_string(up->port.state->port.tty,
			up->uart_dma.rx_buf +
			(up->uart_dma.prev_rx_dma_pos -
			up->uart_dma.rx_buf_dma_phys),
			curr_transmitted_size);
	tty_flip_buffer_push(up->port.state->port.tty);
	up->uart_dma.prev_rx_dma_pos = curr_dma_pos;
	if (up->uart_dma.rx_buf_size +
			up->uart_dma.rx_buf_dma_phys == curr_dma_pos) {
		ret = serial_omap_start_rxdma(up);
		if (ret < 0) {
			serial_omap_stop_rxdma(up);
			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
			serial_out(up, UART_IER, up->ier);
		}
	} else  {
		mod_timer(&up->uart_dma.rx_timer, jiffies +
			usecs_to_jiffies(up->uart_dma.rx_poll_rate));
	}
	up->port_activity = jiffies;
}

static void uart_rx_dma_callback(int lch, u16 ch_status, void *data)
{
	return;
}

static int serial_omap_start_rxdma(struct uart_omap_port *up)
{
	int ret = 0;

	if (up->uart_dma.rx_dma_channel == -1) {
		pm_runtime_get_sync(&up->pdev->dev);
		ret = omap_request_dma(up->uart_dma.uart_dma_rx,
				"UART Rx DMA",
				(void *)uart_rx_dma_callback, up,
				&(up->uart_dma.rx_dma_channel));
		if (ret < 0)
			return ret;

		omap_set_dma_src_params(up->uart_dma.rx_dma_channel, 0,
				OMAP_DMA_AMODE_CONSTANT,
				up->uart_dma.uart_base, 0, 0);
		omap_set_dma_dest_params(up->uart_dma.rx_dma_channel, 0,
				OMAP_DMA_AMODE_POST_INC,
				up->uart_dma.rx_buf_dma_phys, 0, 0);
		omap_set_dma_transfer_params(up->uart_dma.rx_dma_channel,
				OMAP_DMA_DATA_TYPE_S8,
				up->uart_dma.rx_buf_size, 1,
				OMAP_DMA_SYNC_ELEMENT,
				up->uart_dma.uart_dma_rx, 0);
	}
	up->uart_dma.prev_rx_dma_pos = up->uart_dma.rx_buf_dma_phys;
	/* FIXME: Cache maintenance needed here? */
	omap_start_dma(up->uart_dma.rx_dma_channel);
	mod_timer(&up->uart_dma.rx_timer, jiffies +
				usecs_to_jiffies(up->uart_dma.rx_poll_rate));
	up->uart_dma.rx_dma_used = true;
	return ret;
}

static void serial_omap_continue_tx(struct uart_omap_port *up)
{
	struct circ_buf *xmit = &up->port.state->xmit;
	unsigned int start = up->uart_dma.tx_buf_dma_phys
			+ (xmit->tail & (UART_XMIT_SIZE - 1));

	if (uart_circ_empty(xmit))
		return;

	up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
	/*
	 * It is a circular buffer. See if the buffer has wounded back.
	 * If yes it will have to be transferred in two separate dma
	 * transfers
	 */
	if (start + up->uart_dma.tx_buf_size >=
			up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
		up->uart_dma.tx_buf_size =
			(up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) - start;
	omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
				OMAP_DMA_AMODE_CONSTANT,
				up->uart_dma.uart_base, 0, 0);
	omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
				OMAP_DMA_AMODE_POST_INC, start, 0, 0);
	omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
				OMAP_DMA_DATA_TYPE_S8,
				up->uart_dma.tx_buf_size, 1,
				OMAP_DMA_SYNC_ELEMENT,
				up->uart_dma.uart_dma_tx, 0);
	/* FIXME: Cache maintenance needed here? */
	omap_start_dma(up->uart_dma.tx_dma_channel);
}

static void uart_tx_dma_callback(int lch, u16 ch_status, void *data)
{
	struct uart_omap_port *up = (struct uart_omap_port *)data;
	struct circ_buf *xmit = &up->port.state->xmit;

	xmit->tail = (xmit->tail + up->uart_dma.tx_buf_size) & \
			(UART_XMIT_SIZE - 1);
	up->port.icount.tx += up->uart_dma.tx_buf_size;

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(&up->port);

	if (uart_circ_empty(xmit)) {
		spin_lock(&(up->uart_dma.tx_lock));
		serial_omap_stop_tx(&up->port);
		up->uart_dma.tx_dma_used = false;
		spin_unlock(&(up->uart_dma.tx_lock));
	} else {
		omap_stop_dma(up->uart_dma.tx_dma_channel);
		serial_omap_continue_tx(up);
	}
	up->port_activity = jiffies;
	return;
}

static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
{
	struct omap_uart_port_info *omap_up_info;

	omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
	if (!omap_up_info)
		return NULL; /* out of memory */

	of_property_read_u32(dev->of_node, "clock-frequency",
					 &omap_up_info->uartclk);
	return omap_up_info;
}

static int serial_omap_probe(struct platform_device *pdev)
{
	struct uart_omap_port	*up;
	struct resource		*mem, *irq, *dma_tx, *dma_rx;
	struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data;
	int ret = -ENOSPC;

	if (pdev->dev.of_node)
		omap_up_info = of_get_uart_port_info(&pdev->dev);

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
		dev_err(&pdev->dev, "no mem resource?\n");
		return -ENODEV;
	}

	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!irq) {
		dev_err(&pdev->dev, "no irq resource?\n");
		return -ENODEV;
	}

	if (!request_mem_region(mem->start, resource_size(mem),
				pdev->dev.driver->name)) {
		dev_err(&pdev->dev, "memory region already claimed\n");
		return -EBUSY;
	}

	dma_rx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
	if (!dma_rx) {
		ret = -EINVAL;
		goto err;
	}

	dma_tx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
	if (!dma_tx) {
		ret = -EINVAL;
		goto err;
	}

	up = kzalloc(sizeof(*up), GFP_KERNEL);
	if (up == NULL) {
		ret = -ENOMEM;
		goto do_release_region;
	}
	up->pdev = pdev;
	up->port.dev = &pdev->dev;
	up->port.type = PORT_OMAP;
	up->port.iotype = UPIO_MEM;
	up->port.irq = irq->start;

	up->port.regshift = 2;
	up->port.fifosize = 64;
	up->port.ops = &serial_omap_pops;

	if (pdev->dev.of_node)
		up->port.line = of_alias_get_id(pdev->dev.of_node, "serial");
	else
		up->port.line = pdev->id;

	if (up->port.line < 0) {
		dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
								up->port.line);
		ret = -ENODEV;
		goto err;
	}

	sprintf(up->name, "OMAP UART%d", up->port.line);
	up->port.mapbase = mem->start;
	up->port.membase = ioremap(mem->start, resource_size(mem));
	if (!up->port.membase) {
		dev_err(&pdev->dev, "can't ioremap UART\n");
		ret = -ENOMEM;
		goto err;
	}

	up->port.flags = omap_up_info->flags;
	up->port.uartclk = omap_up_info->uartclk;
	if (!up->port.uartclk) {
		up->port.uartclk = DEFAULT_CLK_SPEED;
		dev_warn(&pdev->dev, "No clock speed specified: using default:"
						"%d\n", DEFAULT_CLK_SPEED);
	}
	up->uart_dma.uart_base = mem->start;
	up->errata = omap_up_info->errata;

	if (omap_up_info->dma_enabled) {
		up->uart_dma.uart_dma_tx = dma_tx->start;
		up->uart_dma.uart_dma_rx = dma_rx->start;
		up->use_dma = 1;
		up->uart_dma.rx_buf_size = omap_up_info->dma_rx_buf_size;
		up->uart_dma.rx_timeout = omap_up_info->dma_rx_timeout;
		up->uart_dma.rx_poll_rate = omap_up_info->dma_rx_poll_rate;
		spin_lock_init(&(up->uart_dma.tx_lock));
		spin_lock_init(&(up->uart_dma.rx_lock));
		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
	}

	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
	up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
	pm_qos_add_request(&up->pm_qos_request,
		PM_QOS_CPU_DMA_LATENCY, up->latency);
	serial_omap_uart_wq = create_singlethread_workqueue(up->name);
	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);

	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev,
			omap_up_info->autosuspend_timeout);

	pm_runtime_irq_safe(&pdev->dev);
	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	ui[up->port.line] = up;
	serial_omap_add_console_port(up);

	ret = uart_add_one_port(&serial_omap_reg, &up->port);
	if (ret != 0)
		goto do_release_region;

	pm_runtime_put(&pdev->dev);
	platform_set_drvdata(pdev, up);
	return 0;
err:
	dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
				pdev->id, __func__, ret);
do_release_region:
	release_mem_region(mem->start, resource_size(mem));
	return ret;
}

static int serial_omap_remove(struct platform_device *dev)
{
	struct uart_omap_port *up = platform_get_drvdata(dev);

	if (up) {
		pm_runtime_disable(&up->pdev->dev);
		uart_remove_one_port(&serial_omap_reg, &up->port);
		pm_qos_remove_request(&up->pm_qos_request);

		kfree(up);
	}

	platform_set_drvdata(dev, NULL);
	return 0;
}

/*
 * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
 * The access to uart register after MDR1 Access
 * causes UART to corrupt data.
 *
 * Need a delay =
 * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
 * give 10 times as much
 */
static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
{
	u8 timeout = 255;

	serial_out(up, UART_OMAP_MDR1, mdr1);
	udelay(2);
	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
			UART_FCR_CLEAR_RCVR);
	/*
	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
	 * TX_FIFO_E bit is 1.
	 */
	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
				(UART_LSR_THRE | UART_LSR_DR))) {
		timeout--;
		if (!timeout) {
			/* Should *never* happen. we warn and carry on */
			dev_crit(&up->pdev->dev, "Errata i202: timedout %x\n",
						serial_in(up, UART_LSR));
			break;
		}
		udelay(1);
	}
}

#ifdef CONFIG_PM_RUNTIME
static void serial_omap_restore_context(struct uart_omap_port *up)
{
	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
	else
		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
	serial_out(up, UART_EFR, UART_EFR_ECB);
	serial_out(up, UART_LCR, 0x0); /* Operational mode */
	serial_out(up, UART_IER, 0x0);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
	serial_out(up, UART_DLL, up->dll);
	serial_out(up, UART_DLM, up->dlh);
	serial_out(up, UART_LCR, 0x0); /* Operational mode */
	serial_out(up, UART_IER, up->ier);
	serial_out(up, UART_FCR, up->fcr);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
	serial_out(up, UART_MCR, up->mcr);
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
	serial_out(up, UART_OMAP_SCR, up->scr);
	serial_out(up, UART_EFR, up->efr);
	serial_out(up, UART_LCR, up->lcr);
	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
		serial_omap_mdr1_errataset(up, up->mdr1);
	else
		serial_out(up, UART_OMAP_MDR1, up->mdr1);
}

static int serial_omap_runtime_suspend(struct device *dev)
{
	struct uart_omap_port *up = dev_get_drvdata(dev);
	struct omap_uart_port_info *pdata = dev->platform_data;

	if (!up)
		return -EINVAL;

	if (!pdata || !pdata->enable_wakeup)
		return 0;

	if (pdata->get_context_loss_count)
		up->context_loss_cnt = pdata->get_context_loss_count(dev);

	if (device_may_wakeup(dev)) {
		if (!up->wakeups_enabled) {
			pdata->enable_wakeup(up->pdev, true);
			up->wakeups_enabled = true;
		}
	} else {
		if (up->wakeups_enabled) {
			pdata->enable_wakeup(up->pdev, false);
			up->wakeups_enabled = false;
		}
	}

	/* Errata i291 */
	if (up->use_dma && pdata->set_forceidle &&
			(up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
		pdata->set_forceidle(up->pdev);

	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
	schedule_work(&up->qos_work);

	return 0;
}

static int serial_omap_runtime_resume(struct device *dev)
{
	struct uart_omap_port *up = dev_get_drvdata(dev);
	struct omap_uart_port_info *pdata = dev->platform_data;

	if (up && pdata) {
		if (pdata->get_context_loss_count) {
			u32 loss_cnt = pdata->get_context_loss_count(dev);

			if (up->context_loss_cnt != loss_cnt)
				serial_omap_restore_context(up);
		}

		/* Errata i291 */
		if (up->use_dma && pdata->set_noidle &&
				(up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
			pdata->set_noidle(up->pdev);

		up->latency = up->calc_latency;
		schedule_work(&up->qos_work);
	}

	return 0;
}
#endif

static const struct dev_pm_ops serial_omap_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
				serial_omap_runtime_resume, NULL)
};

#if defined(CONFIG_OF)
static const struct of_device_id omap_serial_of_match[] = {
	{ .compatible = "ti,omap2-uart" },
	{ .compatible = "ti,omap3-uart" },
	{ .compatible = "ti,omap4-uart" },
	{},
};
MODULE_DEVICE_TABLE(of, omap_serial_of_match);
#endif

static struct platform_driver serial_omap_driver = {
	.probe          = serial_omap_probe,
	.remove         = serial_omap_remove,
	.driver		= {
		.name	= DRIVER_NAME,
		.pm	= &serial_omap_dev_pm_ops,
		.of_match_table = of_match_ptr(omap_serial_of_match),
	},
};

static int __init serial_omap_init(void)
{
	int ret;

	ret = uart_register_driver(&serial_omap_reg);
	if (ret != 0)
		return ret;
	ret = platform_driver_register(&serial_omap_driver);
	if (ret != 0)
		uart_unregister_driver(&serial_omap_reg);
	return ret;
}

static void __exit serial_omap_exit(void)
{
	platform_driver_unregister(&serial_omap_driver);
	uart_unregister_driver(&serial_omap_reg);
}

module_init(serial_omap_init);
module_exit(serial_omap_exit);

MODULE_DESCRIPTION("OMAP High Speed UART driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Texas Instruments Inc");
OpenPOWER on IntegriCloud