summaryrefslogtreecommitdiff
path: root/drivers/tty/serial/ifx6x60.c
blob: 68d7ce997ede999fce550d0b6d1ccd6d0e9032be (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
/****************************************************************************
 *
 * Driver for the IFX 6x60 spi modem.
 *
 * Copyright (C) 2008 Option International
 * Copyright (C) 2008 Filip Aben <f.aben@option.com>
 *		      Denis Joseph Barrow <d.barow@option.com>
 *		      Jan Dumon <j.dumon@option.com>
 *
 * Copyright (C) 2009, 2010 Intel Corp
 * Russ Gorby <russ.gorby@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA
 *
 * Driver modified by Intel from Option gtm501l_spi.c
 *
 * Notes
 * o	The driver currently assumes a single device only. If you need to
 *	change this then look for saved_ifx_dev and add a device lookup
 * o	The driver is intended to be big-endian safe but has never been
 *	tested that way (no suitable hardware). There are a couple of FIXME
 *	notes by areas that may need addressing
 * o	Some of the GPIO naming/setup assumptions may need revisiting if
 *	you need to use this driver for another platform.
 *
 *****************************************************************************/
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/termios.h>
#include <linux/tty.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/kfifo.h>
#include <linux/tty_flip.h>
#include <linux/timer.h>
#include <linux/serial.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/rfkill.h>
#include <linux/fs.h>
#include <linux/ip.h>
#include <linux/dmapool.h>
#include <linux/gpio.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/spi/ifx_modem.h>
#include <linux/delay.h>
#include <linux/reboot.h>

#include "ifx6x60.h"

#define IFX_SPI_MORE_MASK		0x10
#define IFX_SPI_MORE_BIT		4	/* bit position in u8 */
#define IFX_SPI_CTS_BIT			6	/* bit position in u8 */
#define IFX_SPI_MODE			SPI_MODE_1
#define IFX_SPI_TTY_ID			0
#define IFX_SPI_TIMEOUT_SEC		2
#define IFX_SPI_HEADER_0		(-1)
#define IFX_SPI_HEADER_F		(-2)

#define PO_POST_DELAY		200
#define IFX_MDM_RST_PMU	4

/* forward reference */
static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
static int ifx_modem_reboot_callback(struct notifier_block *nfb,
				unsigned long event, void *data);
static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev);

/* local variables */
static int spi_bpw = 16;		/* 8, 16 or 32 bit word length */
static struct tty_driver *tty_drv;
static struct ifx_spi_device *saved_ifx_dev;
static struct lock_class_key ifx_spi_key;

static struct notifier_block ifx_modem_reboot_notifier_block = {
	.notifier_call = ifx_modem_reboot_callback,
};

static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev)
{
	gpio_set_value(IFX_MDM_RST_PMU, 1);
	msleep(PO_POST_DELAY);

	return 0;
}

static int ifx_modem_reboot_callback(struct notifier_block *nfb,
				 unsigned long event, void *data)
{
	if (saved_ifx_dev)
		ifx_modem_power_off(saved_ifx_dev);
	else
		pr_warn("no ifx modem active;\n");

	return NOTIFY_OK;
}

/* GPIO/GPE settings */

/**
 *	mrdy_set_high		-	set MRDY GPIO
 *	@ifx: device we are controlling
 *
 */
static inline void mrdy_set_high(struct ifx_spi_device *ifx)
{
	gpio_set_value(ifx->gpio.mrdy, 1);
}

/**
 *	mrdy_set_low		-	clear MRDY GPIO
 *	@ifx: device we are controlling
 *
 */
static inline void mrdy_set_low(struct ifx_spi_device *ifx)
{
	gpio_set_value(ifx->gpio.mrdy, 0);
}

/**
 *	ifx_spi_power_state_set
 *	@ifx_dev: our SPI device
 *	@val: bits to set
 *
 *	Set bit in power status and signal power system if status becomes non-0
 */
static void
ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
{
	unsigned long flags;

	spin_lock_irqsave(&ifx_dev->power_lock, flags);

	/*
	 * if power status is already non-0, just update, else
	 * tell power system
	 */
	if (!ifx_dev->power_status)
		pm_runtime_get(&ifx_dev->spi_dev->dev);
	ifx_dev->power_status |= val;

	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
}

/**
 *	ifx_spi_power_state_clear	-	clear power bit
 *	@ifx_dev: our SPI device
 *	@val: bits to clear
 *
 *	clear bit in power status and signal power system if status becomes 0
 */
static void
ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
{
	unsigned long flags;

	spin_lock_irqsave(&ifx_dev->power_lock, flags);

	if (ifx_dev->power_status) {
		ifx_dev->power_status &= ~val;
		if (!ifx_dev->power_status)
			pm_runtime_put(&ifx_dev->spi_dev->dev);
	}

	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
}

/**
 *	swap_buf_8
 *	@buf: our buffer
 *	@len : number of bytes (not words) in the buffer
 *	@end: end of buffer
 *
 *	Swap the contents of a buffer into big endian format
 */
static inline void swap_buf_8(unsigned char *buf, int len, void *end)
{
	/* don't swap buffer if SPI word width is 8 bits */
	return;
}

/**
 *	swap_buf_16
 *	@buf: our buffer
 *	@len : number of bytes (not words) in the buffer
 *	@end: end of buffer
 *
 *	Swap the contents of a buffer into big endian format
 */
static inline void swap_buf_16(unsigned char *buf, int len, void *end)
{
	int n;

	u16 *buf_16 = (u16 *)buf;
	len = ((len + 1) >> 1);
	if ((void *)&buf_16[len] > end) {
		pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!",
		       &buf_16[len], end);
		return;
	}
	for (n = 0; n < len; n++) {
		*buf_16 = cpu_to_be16(*buf_16);
		buf_16++;
	}
}

/**
 *	swap_buf_32
 *	@buf: our buffer
 *	@len : number of bytes (not words) in the buffer
 *	@end: end of buffer
 *
 *	Swap the contents of a buffer into big endian format
 */
static inline void swap_buf_32(unsigned char *buf, int len, void *end)
{
	int n;

	u32 *buf_32 = (u32 *)buf;
	len = (len + 3) >> 2;

	if ((void *)&buf_32[len] > end) {
		pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n",
		       &buf_32[len], end);
		return;
	}
	for (n = 0; n < len; n++) {
		*buf_32 = cpu_to_be32(*buf_32);
		buf_32++;
	}
}

/**
 *	mrdy_assert		-	assert MRDY line
 *	@ifx_dev: our SPI device
 *
 *	Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
 *	now.
 *
 *	FIXME: Can SRDY even go high as we are running this code ?
 */
static void mrdy_assert(struct ifx_spi_device *ifx_dev)
{
	int val = gpio_get_value(ifx_dev->gpio.srdy);
	if (!val) {
		if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
				      &ifx_dev->flags)) {
			mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ);

		}
	}
	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
	mrdy_set_high(ifx_dev);
}

/**
 *	ifx_spi_hangup		-	hang up an IFX device
 *	@ifx_dev: our SPI device
 *
 *	Hang up the tty attached to the IFX device if one is currently
 *	open. If not take no action
 */
static void ifx_spi_ttyhangup(struct ifx_spi_device *ifx_dev)
{
	struct tty_port *pport = &ifx_dev->tty_port;
	struct tty_struct *tty = tty_port_tty_get(pport);
	if (tty) {
		tty_hangup(tty);
		tty_kref_put(tty);
	}
}

/**
 *	ifx_spi_timeout		-	SPI timeout
 *	@arg: our SPI device
 *
 *	The SPI has timed out: hang up the tty. Users will then see a hangup
 *	and error events.
 */
static void ifx_spi_timeout(unsigned long arg)
{
	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *)arg;

	dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
	ifx_spi_ttyhangup(ifx_dev);
	mrdy_set_low(ifx_dev);
	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
}

/* char/tty operations */

/**
 *	ifx_spi_tiocmget	-	get modem lines
 *	@tty: our tty device
 *	@filp: file handle issuing the request
 *
 *	Map the signal state into Linux modem flags and report the value
 *	in Linux terms
 */
static int ifx_spi_tiocmget(struct tty_struct *tty)
{
	unsigned int value;
	struct ifx_spi_device *ifx_dev = tty->driver_data;

	value =
	(test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
	(test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
	(test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
	(test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
	(test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
	(test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
	return value;
}

/**
 *	ifx_spi_tiocmset	-	set modem bits
 *	@tty: the tty structure
 *	@set: bits to set
 *	@clear: bits to clear
 *
 *	The IFX6x60 only supports DTR and RTS. Set them accordingly
 *	and flag that an update to the modem is needed.
 *
 *	FIXME: do we need to kick the tranfers when we do this ?
 */
static int ifx_spi_tiocmset(struct tty_struct *tty,
			    unsigned int set, unsigned int clear)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;

	if (set & TIOCM_RTS)
		set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
	if (set & TIOCM_DTR)
		set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
	if (clear & TIOCM_RTS)
		clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
	if (clear & TIOCM_DTR)
		clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);

	set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
	return 0;
}

/**
 *	ifx_spi_open	-	called on tty open
 *	@tty: our tty device
 *	@filp: file handle being associated with the tty
 *
 *	Open the tty interface. We let the tty_port layer do all the work
 *	for us.
 *
 *	FIXME: Remove single device assumption and saved_ifx_dev
 */
static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
{
	return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
}

/**
 *	ifx_spi_close	-	called when our tty closes
 *	@tty: the tty being closed
 *	@filp: the file handle being closed
 *
 *	Perform the close of the tty. We use the tty_port layer to do all
 *	our hard work.
 */
static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;
	tty_port_close(&ifx_dev->tty_port, tty, filp);
	/* FIXME: should we do an ifx_spi_reset here ? */
}

/**
 *	ifx_decode_spi_header	-	decode received header
 *	@buffer: the received data
 *	@length: decoded length
 *	@more: decoded more flag
 *	@received_cts: status of cts we received
 *
 *	Note how received_cts is handled -- if header is all F it is left
 *	the same as it was, if header is all 0 it is set to 0 otherwise it is
 *	taken from the incoming header.
 *
 *	FIXME: endianness
 */
static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
			unsigned char *more, unsigned char *received_cts)
{
	u16 h1;
	u16 h2;
	u16 *in_buffer = (u16 *)buffer;

	h1 = *in_buffer;
	h2 = *(in_buffer+1);

	if (h1 == 0 && h2 == 0) {
		*received_cts = 0;
		return IFX_SPI_HEADER_0;
	} else if (h1 == 0xffff && h2 == 0xffff) {
		/* spi_slave_cts remains as it was */
		return IFX_SPI_HEADER_F;
	}

	*length = h1 & 0xfff;	/* upper bits of byte are flags */
	*more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
	*received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
	return 0;
}

/**
 *	ifx_setup_spi_header	-	set header fields
 *	@txbuffer: pointer to start of SPI buffer
 *	@tx_count: bytes
 *	@more: indicate if more to follow
 *
 *	Format up an SPI header for a transfer
 *
 *	FIXME: endianness?
 */
static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
					unsigned char more)
{
	*(u16 *)(txbuffer) = tx_count;
	*(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
	txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
}

/**
 *	ifx_spi_wakeup_serial	-	SPI space made
 *	@port_data: our SPI device
 *
 *	We have emptied the FIFO enough that we want to get more data
 *	queued into it. Poke the line discipline via tty_wakeup so that
 *	it will feed us more bits
 */
static void ifx_spi_wakeup_serial(struct ifx_spi_device *ifx_dev)
{
	struct tty_struct *tty;

	tty = tty_port_tty_get(&ifx_dev->tty_port);
	if (!tty)
		return;
	tty_wakeup(tty);
	tty_kref_put(tty);
}

/**
 *	ifx_spi_prepare_tx_buffer	-	prepare transmit frame
 *	@ifx_dev: our SPI device
 *
 *	The transmit buffr needs a header and various other bits of
 *	information followed by as much data as we can pull from the FIFO
 *	and transfer. This function formats up a suitable buffer in the
 *	ifx_dev->tx_buffer
 *
 *	FIXME: performance - should we wake the tty when the queue is half
 *			     empty ?
 */
static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
{
	int temp_count;
	int queue_length;
	int tx_count;
	unsigned char *tx_buffer;

	tx_buffer = ifx_dev->tx_buffer;

	/* make room for required SPI header */
	tx_buffer += IFX_SPI_HEADER_OVERHEAD;
	tx_count = IFX_SPI_HEADER_OVERHEAD;

	/* clear to signal no more data if this turns out to be the
	 * last buffer sent in a sequence */
	ifx_dev->spi_more = 0;

	/* if modem cts is set, just send empty buffer */
	if (!ifx_dev->spi_slave_cts) {
		/* see if there's tx data */
		queue_length = kfifo_len(&ifx_dev->tx_fifo);
		if (queue_length != 0) {
			/* data to mux -- see if there's room for it */
			temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
			temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
					tx_buffer, temp_count,
					&ifx_dev->fifo_lock);

			/* update buffer pointer and data count in message */
			tx_buffer += temp_count;
			tx_count += temp_count;
			if (temp_count == queue_length)
				/* poke port to get more data */
				ifx_spi_wakeup_serial(ifx_dev);
			else /* more data in port, use next SPI message */
				ifx_dev->spi_more = 1;
		}
	}
	/* have data and info for header -- set up SPI header in buffer */
	/* spi header needs payload size, not entire buffer size */
	ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
					tx_count-IFX_SPI_HEADER_OVERHEAD,
					ifx_dev->spi_more);
	/* swap actual data in the buffer */
	ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count,
		&ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
	return tx_count;
}

/**
 *	ifx_spi_write		-	line discipline write
 *	@tty: our tty device
 *	@buf: pointer to buffer to write (kernel space)
 *	@count: size of buffer
 *
 *	Write the characters we have been given into the FIFO. If the device
 *	is not active then activate it, when the SRDY line is asserted back
 *	this will commence I/O
 */
static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
			 int count)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;
	unsigned char *tmp_buf = (unsigned char *)buf;
	unsigned long flags;
	bool is_fifo_empty;
	int tx_count;

	spin_lock_irqsave(&ifx_dev->fifo_lock, flags);
	is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo);
	tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count);
	spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags);
	if (is_fifo_empty)
		mrdy_assert(ifx_dev);

	return tx_count;
}

/**
 *	ifx_spi_chars_in_buffer	-	line discipline helper
 *	@tty: our tty device
 *
 *	Report how much data we can accept before we drop bytes. As we use
 *	a simple FIFO this is nice and easy.
 */
static int ifx_spi_write_room(struct tty_struct *tty)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;
	return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
}

/**
 *	ifx_spi_chars_in_buffer	-	line discipline helper
 *	@tty: our tty device
 *
 *	Report how many characters we have buffered. In our case this is the
 *	number of bytes sitting in our transmit FIFO.
 */
static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;
	return kfifo_len(&ifx_dev->tx_fifo);
}

/**
 *	ifx_port_hangup
 *	@port: our tty port
 *
 *	tty port hang up. Called when tty_hangup processing is invoked either
 *	by loss of carrier, or by software (eg vhangup). Serialized against
 *	activate/shutdown by the tty layer.
 */
static void ifx_spi_hangup(struct tty_struct *tty)
{
	struct ifx_spi_device *ifx_dev = tty->driver_data;
	tty_port_hangup(&ifx_dev->tty_port);
}

/**
 *	ifx_port_activate
 *	@port: our tty port
 *
 *	tty port activate method - called for first open. Serialized
 *	with hangup and shutdown by the tty layer.
 */
static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
{
	struct ifx_spi_device *ifx_dev =
		container_of(port, struct ifx_spi_device, tty_port);

	/* clear any old data; can't do this in 'close' */
	kfifo_reset(&ifx_dev->tx_fifo);

	/* clear any flag which may be set in port shutdown procedure */
	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
	clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);

	/* put port data into this tty */
	tty->driver_data = ifx_dev;

	/* allows flip string push from int context */
	port->low_latency = 1;

	/* set flag to allows data transfer */
	set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);

	return 0;
}

/**
 *	ifx_port_shutdown
 *	@port: our tty port
 *
 *	tty port shutdown method - called for last port close. Serialized
 *	with hangup and activate by the tty layer.
 */
static void ifx_port_shutdown(struct tty_port *port)
{
	struct ifx_spi_device *ifx_dev =
		container_of(port, struct ifx_spi_device, tty_port);

	clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
	mrdy_set_low(ifx_dev);
	del_timer(&ifx_dev->spi_timer);
	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
	tasklet_kill(&ifx_dev->io_work_tasklet);
}

static const struct tty_port_operations ifx_tty_port_ops = {
	.activate = ifx_port_activate,
	.shutdown = ifx_port_shutdown,
};

static const struct tty_operations ifx_spi_serial_ops = {
	.open = ifx_spi_open,
	.close = ifx_spi_close,
	.write = ifx_spi_write,
	.hangup = ifx_spi_hangup,
	.write_room = ifx_spi_write_room,
	.chars_in_buffer = ifx_spi_chars_in_buffer,
	.tiocmget = ifx_spi_tiocmget,
	.tiocmset = ifx_spi_tiocmset,
};

/**
 *	ifx_spi_insert_fip_string	-	queue received data
 *	@ifx_ser: our SPI device
 *	@chars: buffer we have received
 *	@size: number of chars reeived
 *
 *	Queue bytes to the tty assuming the tty side is currently open. If
 *	not the discard the data.
 */
static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
				    unsigned char *chars, size_t size)
{
	tty_insert_flip_string(&ifx_dev->tty_port, chars, size);
	tty_flip_buffer_push(&ifx_dev->tty_port);
}

/**
 *	ifx_spi_complete	-	SPI transfer completed
 *	@ctx: our SPI device
 *
 *	An SPI transfer has completed. Process any received data and kick off
 *	any further transmits we can commence.
 */
static void ifx_spi_complete(void *ctx)
{
	struct ifx_spi_device *ifx_dev = ctx;
	struct tty_struct *tty;
	struct tty_ldisc *ldisc = NULL;
	int length;
	int actual_length;
	unsigned char more;
	unsigned char cts;
	int local_write_pending = 0;
	int queue_length;
	int srdy;
	int decode_result;

	mrdy_set_low(ifx_dev);

	if (!ifx_dev->spi_msg.status) {
		/* check header validity, get comm flags */
		ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
			&ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
		decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
				&length, &more, &cts);
		if (decode_result == IFX_SPI_HEADER_0) {
			dev_dbg(&ifx_dev->spi_dev->dev,
				"ignore input: invalid header 0");
			ifx_dev->spi_slave_cts = 0;
			goto complete_exit;
		} else if (decode_result == IFX_SPI_HEADER_F) {
			dev_dbg(&ifx_dev->spi_dev->dev,
				"ignore input: invalid header F");
			goto complete_exit;
		}

		ifx_dev->spi_slave_cts = cts;

		actual_length = min((unsigned int)length,
					ifx_dev->spi_msg.actual_length);
		ifx_dev->swap_buf(
			(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
			 actual_length,
			 &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
		ifx_spi_insert_flip_string(
			ifx_dev,
			ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
			(size_t)actual_length);
	} else {
		dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
		       ifx_dev->spi_msg.status);
	}

complete_exit:
	if (ifx_dev->write_pending) {
		ifx_dev->write_pending = 0;
		local_write_pending = 1;
	}

	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));

	queue_length = kfifo_len(&ifx_dev->tx_fifo);
	srdy = gpio_get_value(ifx_dev->gpio.srdy);
	if (!srdy)
		ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);

	/* schedule output if there is more to do */
	if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
		tasklet_schedule(&ifx_dev->io_work_tasklet);
	else {
		if (more || ifx_dev->spi_more || queue_length > 0 ||
			local_write_pending) {
			if (ifx_dev->spi_slave_cts) {
				if (more)
					mrdy_assert(ifx_dev);
			} else
				mrdy_assert(ifx_dev);
		} else {
			/*
			 * poke line discipline driver if any for more data
			 * may or may not get more data to write
			 * for now, say not busy
			 */
			ifx_spi_power_state_clear(ifx_dev,
						  IFX_SPI_POWER_DATA_PENDING);
			tty = tty_port_tty_get(&ifx_dev->tty_port);
			if (tty) {
				ldisc = tty_ldisc_ref(tty);
				if (ldisc) {
					ldisc->ops->write_wakeup(tty);
					tty_ldisc_deref(ldisc);
				}
				tty_kref_put(tty);
			}
		}
	}
}

/**
 *	ifx_spio_io		-	I/O tasklet
 *	@data: our SPI device
 *
 *	Queue data for transmission if possible and then kick off the
 *	transfer.
 */
static void ifx_spi_io(unsigned long data)
{
	int retval;
	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;

	if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) &&
		test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) {
		if (ifx_dev->gpio.unack_srdy_int_nb > 0)
			ifx_dev->gpio.unack_srdy_int_nb--;

		ifx_spi_prepare_tx_buffer(ifx_dev);

		spi_message_init(&ifx_dev->spi_msg);
		INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);

		ifx_dev->spi_msg.context = ifx_dev;
		ifx_dev->spi_msg.complete = ifx_spi_complete;

		/* set up our spi transfer */
		/* note len is BYTES, not transfers */
		ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
		ifx_dev->spi_xfer.cs_change = 0;
		ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz;
		/* ifx_dev->spi_xfer.speed_hz = 390625; */
		ifx_dev->spi_xfer.bits_per_word =
			ifx_dev->spi_dev->bits_per_word;

		ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
		ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;

		/*
		 * setup dma pointers
		 */
		if (ifx_dev->use_dma) {
			ifx_dev->spi_msg.is_dma_mapped = 1;
			ifx_dev->tx_dma = ifx_dev->tx_bus;
			ifx_dev->rx_dma = ifx_dev->rx_bus;
			ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
			ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
		} else {
			ifx_dev->spi_msg.is_dma_mapped = 0;
			ifx_dev->tx_dma = (dma_addr_t)0;
			ifx_dev->rx_dma = (dma_addr_t)0;
			ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
			ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
		}

		spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);

		/* Assert MRDY. This may have already been done by the write
		 * routine.
		 */
		mrdy_assert(ifx_dev);

		retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
		if (retval) {
			clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
				  &ifx_dev->flags);
			tasklet_schedule(&ifx_dev->io_work_tasklet);
			return;
		}
	} else
		ifx_dev->write_pending = 1;
}

/**
 *	ifx_spi_free_port	-	free up the tty side
 *	@ifx_dev: IFX device going away
 *
 *	Unregister and free up a port when the device goes away
 */
static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
{
	if (ifx_dev->tty_dev)
		tty_unregister_device(tty_drv, ifx_dev->minor);
	tty_port_destroy(&ifx_dev->tty_port);
	kfifo_free(&ifx_dev->tx_fifo);
}

/**
 *	ifx_spi_create_port	-	create a new port
 *	@ifx_dev: our spi device
 *
 *	Allocate and initialise the tty port that goes with this interface
 *	and add it to the tty layer so that it can be opened.
 */
static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
{
	int ret = 0;
	struct tty_port *pport = &ifx_dev->tty_port;

	spin_lock_init(&ifx_dev->fifo_lock);
	lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
		&ifx_spi_key, 0);

	if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
		ret = -ENOMEM;
		goto error_ret;
	}

	tty_port_init(pport);
	pport->ops = &ifx_tty_port_ops;
	ifx_dev->minor = IFX_SPI_TTY_ID;
	ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv,
			ifx_dev->minor, &ifx_dev->spi_dev->dev);
	if (IS_ERR(ifx_dev->tty_dev)) {
		dev_dbg(&ifx_dev->spi_dev->dev,
			"%s: registering tty device failed", __func__);
		ret = PTR_ERR(ifx_dev->tty_dev);
		goto error_port;
	}
	return 0;

error_port:
	tty_port_destroy(pport);
error_ret:
	ifx_spi_free_port(ifx_dev);
	return ret;
}

/**
 *	ifx_spi_handle_srdy		-	handle SRDY
 *	@ifx_dev: device asserting SRDY
 *
 *	Check our device state and see what we need to kick off when SRDY
 *	is asserted. This usually means killing the timer and firing off the
 *	I/O processing.
 */
static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
{
	if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
		del_timer(&ifx_dev->spi_timer);
		clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
	}

	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);

	if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
		tasklet_schedule(&ifx_dev->io_work_tasklet);
	else
		set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
}

/**
 *	ifx_spi_srdy_interrupt	-	SRDY asserted
 *	@irq: our IRQ number
 *	@dev: our ifx device
 *
 *	The modem asserted SRDY. Handle the srdy event
 */
static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
{
	struct ifx_spi_device *ifx_dev = dev;
	ifx_dev->gpio.unack_srdy_int_nb++;
	ifx_spi_handle_srdy(ifx_dev);
	return IRQ_HANDLED;
}

/**
 *	ifx_spi_reset_interrupt	-	Modem has changed reset state
 *	@irq: interrupt number
 *	@dev: our device pointer
 *
 *	The modem has either entered or left reset state. Check the GPIO
 *	line to see which.
 *
 *	FIXME: review locking on MR_INPROGRESS versus
 *	parallel unsolicited reset/solicited reset
 */
static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
{
	struct ifx_spi_device *ifx_dev = dev;
	int val = gpio_get_value(ifx_dev->gpio.reset_out);
	int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);

	if (val == 0) {
		/* entered reset */
		set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
		if (!solreset) {
			/* unsolicited reset  */
			ifx_spi_ttyhangup(ifx_dev);
		}
	} else {
		/* exited reset */
		clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
		if (solreset) {
			set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
			wake_up(&ifx_dev->mdm_reset_wait);
		}
	}
	return IRQ_HANDLED;
}

/**
 *	ifx_spi_free_device - free device
 *	@ifx_dev: device to free
 *
 *	Free the IFX device
 */
static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
{
	ifx_spi_free_port(ifx_dev);
	dma_free_coherent(&ifx_dev->spi_dev->dev,
				IFX_SPI_TRANSFER_SIZE,
				ifx_dev->tx_buffer,
				ifx_dev->tx_bus);
	dma_free_coherent(&ifx_dev->spi_dev->dev,
				IFX_SPI_TRANSFER_SIZE,
				ifx_dev->rx_buffer,
				ifx_dev->rx_bus);
}

/**
 *	ifx_spi_reset	-	reset modem
 *	@ifx_dev: modem to reset
 *
 *	Perform a reset on the modem
 */
static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
{
	int ret;
	/*
	 * set up modem power, reset
	 *
	 * delays are required on some platforms for the modem
	 * to reset properly
	 */
	set_bit(MR_START, &ifx_dev->mdm_reset_state);
	gpio_set_value(ifx_dev->gpio.po, 0);
	gpio_set_value(ifx_dev->gpio.reset, 0);
	msleep(25);
	gpio_set_value(ifx_dev->gpio.reset, 1);
	msleep(1);
	gpio_set_value(ifx_dev->gpio.po, 1);
	msleep(1);
	gpio_set_value(ifx_dev->gpio.po, 0);
	ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
				 test_bit(MR_COMPLETE,
					  &ifx_dev->mdm_reset_state),
				 IFX_RESET_TIMEOUT);
	if (!ret)
		dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
			 ifx_dev->mdm_reset_state);

	ifx_dev->mdm_reset_state = 0;
	return ret;
}

/**
 *	ifx_spi_spi_probe	-	probe callback
 *	@spi: our possible matching SPI device
 *
 *	Probe for a 6x60 modem on SPI bus. Perform any needed device and
 *	GPIO setup.
 *
 *	FIXME:
 *	-	Support for multiple devices
 *	-	Split out MID specific GPIO handling eventually
 */

static int ifx_spi_spi_probe(struct spi_device *spi)
{
	int ret;
	int srdy;
	struct ifx_modem_platform_data *pl_data;
	struct ifx_spi_device *ifx_dev;

	if (saved_ifx_dev) {
		dev_dbg(&spi->dev, "ignoring subsequent detection");
		return -ENODEV;
	}

	pl_data = (struct ifx_modem_platform_data *)spi->dev.platform_data;
	if (!pl_data) {
		dev_err(&spi->dev, "missing platform data!");
		return -ENODEV;
	}

	/* initialize structure to hold our device variables */
	ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
	if (!ifx_dev) {
		dev_err(&spi->dev, "spi device allocation failed");
		return -ENOMEM;
	}
	saved_ifx_dev = ifx_dev;
	ifx_dev->spi_dev = spi;
	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
	spin_lock_init(&ifx_dev->write_lock);
	spin_lock_init(&ifx_dev->power_lock);
	ifx_dev->power_status = 0;
	init_timer(&ifx_dev->spi_timer);
	ifx_dev->spi_timer.function = ifx_spi_timeout;
	ifx_dev->spi_timer.data = (unsigned long)ifx_dev;
	ifx_dev->modem = pl_data->modem_type;
	ifx_dev->use_dma = pl_data->use_dma;
	ifx_dev->max_hz = pl_data->max_hz;
	/* initialize spi mode, etc */
	spi->max_speed_hz = ifx_dev->max_hz;
	spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
	spi->bits_per_word = spi_bpw;
	ret = spi_setup(spi);
	if (ret) {
		dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
		return -ENODEV;
	}

	/* init swap_buf function according to word width configuration */
	if (spi->bits_per_word == 32)
		ifx_dev->swap_buf = swap_buf_32;
	else if (spi->bits_per_word == 16)
		ifx_dev->swap_buf = swap_buf_16;
	else
		ifx_dev->swap_buf = swap_buf_8;

	/* ensure SPI protocol flags are initialized to enable transfer */
	ifx_dev->spi_more = 0;
	ifx_dev->spi_slave_cts = 0;

	/*initialize transfer and dma buffers */
	ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
				IFX_SPI_TRANSFER_SIZE,
				&ifx_dev->tx_bus,
				GFP_KERNEL);
	if (!ifx_dev->tx_buffer) {
		dev_err(&spi->dev, "DMA-TX buffer allocation failed");
		ret = -ENOMEM;
		goto error_ret;
	}
	ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
				IFX_SPI_TRANSFER_SIZE,
				&ifx_dev->rx_bus,
				GFP_KERNEL);
	if (!ifx_dev->rx_buffer) {
		dev_err(&spi->dev, "DMA-RX buffer allocation failed");
		ret = -ENOMEM;
		goto error_ret;
	}

	/* initialize waitq for modem reset */
	init_waitqueue_head(&ifx_dev->mdm_reset_wait);

	spi_set_drvdata(spi, ifx_dev);
	tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io,
						(unsigned long)ifx_dev);

	set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);

	/* create our tty port */
	ret = ifx_spi_create_port(ifx_dev);
	if (ret != 0) {
		dev_err(&spi->dev, "create default tty port failed");
		goto error_ret;
	}

	ifx_dev->gpio.reset = pl_data->rst_pmu;
	ifx_dev->gpio.po = pl_data->pwr_on;
	ifx_dev->gpio.mrdy = pl_data->mrdy;
	ifx_dev->gpio.srdy = pl_data->srdy;
	ifx_dev->gpio.reset_out = pl_data->rst_out;

	dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
		 ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
		 ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);

	/* Configure gpios */
	ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
	if (ret < 0) {
		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
			ifx_dev->gpio.reset);
		goto error_ret;
	}
	ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
	ret += gpio_export(ifx_dev->gpio.reset, 1);
	if (ret) {
		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
			ifx_dev->gpio.reset);
		ret = -EBUSY;
		goto error_ret2;
	}

	ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
	ret += gpio_direction_output(ifx_dev->gpio.po, 0);
	ret += gpio_export(ifx_dev->gpio.po, 1);
	if (ret) {
		dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
			ifx_dev->gpio.po);
		ret = -EBUSY;
		goto error_ret3;
	}

	ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
	if (ret < 0) {
		dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
			ifx_dev->gpio.mrdy);
		goto error_ret3;
	}
	ret += gpio_export(ifx_dev->gpio.mrdy, 1);
	ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
	if (ret) {
		dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
			ifx_dev->gpio.mrdy);
		ret = -EBUSY;
		goto error_ret4;
	}

	ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
	if (ret < 0) {
		dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
			ifx_dev->gpio.srdy);
		ret = -EBUSY;
		goto error_ret4;
	}
	ret += gpio_export(ifx_dev->gpio.srdy, 1);
	ret += gpio_direction_input(ifx_dev->gpio.srdy);
	if (ret) {
		dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
			ifx_dev->gpio.srdy);
		ret = -EBUSY;
		goto error_ret5;
	}

	ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
	if (ret < 0) {
		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
			ifx_dev->gpio.reset_out);
		goto error_ret5;
	}
	ret += gpio_export(ifx_dev->gpio.reset_out, 1);
	ret += gpio_direction_input(ifx_dev->gpio.reset_out);
	if (ret) {
		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
			ifx_dev->gpio.reset_out);
		ret = -EBUSY;
		goto error_ret6;
	}

	ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
			  ifx_spi_reset_interrupt,
			  IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
		(void *)ifx_dev);
	if (ret) {
		dev_err(&spi->dev, "Unable to get irq %x\n",
			gpio_to_irq(ifx_dev->gpio.reset_out));
		goto error_ret6;
	}

	ret = ifx_spi_reset(ifx_dev);

	ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
			  ifx_spi_srdy_interrupt,
			  IRQF_TRIGGER_RISING, DRVNAME,
			  (void *)ifx_dev);
	if (ret) {
		dev_err(&spi->dev, "Unable to get irq %x",
			gpio_to_irq(ifx_dev->gpio.srdy));
		goto error_ret7;
	}

	/* set pm runtime power state and register with power system */
	pm_runtime_set_active(&spi->dev);
	pm_runtime_enable(&spi->dev);

	/* handle case that modem is already signaling SRDY */
	/* no outgoing tty open at this point, this just satisfies the
	 * modem's read and should reset communication properly
	 */
	srdy = gpio_get_value(ifx_dev->gpio.srdy);

	if (srdy) {
		mrdy_assert(ifx_dev);
		ifx_spi_handle_srdy(ifx_dev);
	} else
		mrdy_set_low(ifx_dev);
	return 0;

error_ret7:
	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
error_ret6:
	gpio_free(ifx_dev->gpio.srdy);
error_ret5:
	gpio_free(ifx_dev->gpio.mrdy);
error_ret4:
	gpio_free(ifx_dev->gpio.reset);
error_ret3:
	gpio_free(ifx_dev->gpio.po);
error_ret2:
	gpio_free(ifx_dev->gpio.reset_out);
error_ret:
	ifx_spi_free_device(ifx_dev);
	saved_ifx_dev = NULL;
	return ret;
}

/**
 *	ifx_spi_spi_remove	-	SPI device was removed
 *	@spi: SPI device
 *
 *	FIXME: We should be shutting the device down here not in
 *	the module unload path.
 */

static int ifx_spi_spi_remove(struct spi_device *spi)
{
	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
	/* stop activity */
	tasklet_kill(&ifx_dev->io_work_tasklet);
	/* free irq */
	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
	free_irq(gpio_to_irq(ifx_dev->gpio.srdy), (void *)ifx_dev);

	gpio_free(ifx_dev->gpio.srdy);
	gpio_free(ifx_dev->gpio.mrdy);
	gpio_free(ifx_dev->gpio.reset);
	gpio_free(ifx_dev->gpio.po);
	gpio_free(ifx_dev->gpio.reset_out);

	/* free allocations */
	ifx_spi_free_device(ifx_dev);

	saved_ifx_dev = NULL;
	return 0;
}

/**
 *	ifx_spi_spi_shutdown	-	called on SPI shutdown
 *	@spi: SPI device
 *
 *	No action needs to be taken here
 */

static void ifx_spi_spi_shutdown(struct spi_device *spi)
{
	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);

	ifx_modem_power_off(ifx_dev);
}

/*
 * various suspends and resumes have nothing to do
 * no hardware to save state for
 */

/**
 *	ifx_spi_spi_suspend	-	suspend SPI on system suspend
 *	@dev: device being suspended
 *
 *	Suspend the SPI side. No action needed on Intel MID platforms, may
 *	need extending for other systems.
 */
static int ifx_spi_spi_suspend(struct spi_device *spi, pm_message_t msg)
{
	return 0;
}

/**
 *	ifx_spi_spi_resume	-	resume SPI side on system resume
 *	@dev: device being suspended
 *
 *	Suspend the SPI side. No action needed on Intel MID platforms, may
 *	need extending for other systems.
 */
static int ifx_spi_spi_resume(struct spi_device *spi)
{
	return 0;
}

/**
 *	ifx_spi_pm_suspend	-	suspend modem on system suspend
 *	@dev: device being suspended
 *
 *	Suspend the modem. No action needed on Intel MID platforms, may
 *	need extending for other systems.
 */
static int ifx_spi_pm_suspend(struct device *dev)
{
	return 0;
}

/**
 *	ifx_spi_pm_resume	-	resume modem on system resume
 *	@dev: device being suspended
 *
 *	Allow the modem to resume. No action needed.
 *
 *	FIXME: do we need to reset anything here ?
 */
static int ifx_spi_pm_resume(struct device *dev)
{
	return 0;
}

/**
 *	ifx_spi_pm_runtime_resume	-	suspend modem
 *	@dev: device being suspended
 *
 *	Allow the modem to resume. No action needed.
 */
static int ifx_spi_pm_runtime_resume(struct device *dev)
{
	return 0;
}

/**
 *	ifx_spi_pm_runtime_suspend	-	suspend modem
 *	@dev: device being suspended
 *
 *	Allow the modem to suspend and thus suspend to continue up the
 *	device tree.
 */
static int ifx_spi_pm_runtime_suspend(struct device *dev)
{
	return 0;
}

/**
 *	ifx_spi_pm_runtime_idle		-	check if modem idle
 *	@dev: our device
 *
 *	Check conditions and queue runtime suspend if idle.
 */
static int ifx_spi_pm_runtime_idle(struct device *dev)
{
	struct spi_device *spi = to_spi_device(dev);
	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);

	if (!ifx_dev->power_status)
		pm_runtime_suspend(dev);

	return 0;
}

static const struct dev_pm_ops ifx_spi_pm = {
	.resume = ifx_spi_pm_resume,
	.suspend = ifx_spi_pm_suspend,
	.runtime_resume = ifx_spi_pm_runtime_resume,
	.runtime_suspend = ifx_spi_pm_runtime_suspend,
	.runtime_idle = ifx_spi_pm_runtime_idle
};

static const struct spi_device_id ifx_id_table[] = {
	{"ifx6160", 0},
	{"ifx6260", 0},
	{ }
};
MODULE_DEVICE_TABLE(spi, ifx_id_table);

/* spi operations */
static struct spi_driver ifx_spi_driver = {
	.driver = {
		.name = DRVNAME,
		.pm = &ifx_spi_pm,
		.owner = THIS_MODULE},
	.probe = ifx_spi_spi_probe,
	.shutdown = ifx_spi_spi_shutdown,
	.remove = ifx_spi_spi_remove,
	.suspend = ifx_spi_spi_suspend,
	.resume = ifx_spi_spi_resume,
	.id_table = ifx_id_table
};

/**
 *	ifx_spi_exit	-	module exit
 *
 *	Unload the module.
 */

static void __exit ifx_spi_exit(void)
{
	/* unregister */
	tty_unregister_driver(tty_drv);
	put_tty_driver(tty_drv);
	spi_unregister_driver((void *)&ifx_spi_driver);
	unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
}

/**
 *	ifx_spi_init		-	module entry point
 *
 *	Initialise the SPI and tty interfaces for the IFX SPI driver
 *	We need to initialize upper-edge spi driver after the tty
 *	driver because otherwise the spi probe will race
 */

static int __init ifx_spi_init(void)
{
	int result;

	tty_drv = alloc_tty_driver(1);
	if (!tty_drv) {
		pr_err("%s: alloc_tty_driver failed", DRVNAME);
		return -ENOMEM;
	}

	tty_drv->driver_name = DRVNAME;
	tty_drv->name = TTYNAME;
	tty_drv->minor_start = IFX_SPI_TTY_ID;
	tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
	tty_drv->subtype = SERIAL_TYPE_NORMAL;
	tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
	tty_drv->init_termios = tty_std_termios;

	tty_set_operations(tty_drv, &ifx_spi_serial_ops);

	result = tty_register_driver(tty_drv);
	if (result) {
		pr_err("%s: tty_register_driver failed(%d)",
			DRVNAME, result);
		goto err_free_tty;
	}

	result = spi_register_driver((void *)&ifx_spi_driver);
	if (result) {
		pr_err("%s: spi_register_driver failed(%d)",
			DRVNAME, result);
		goto err_unreg_tty;
	}

	result = register_reboot_notifier(&ifx_modem_reboot_notifier_block);
	if (result) {
		pr_err("%s: register ifx modem reboot notifier failed(%d)",
			DRVNAME, result);
		goto err_unreg_spi;
	}

	return 0;
err_unreg_spi:
	spi_unregister_driver((void *)&ifx_spi_driver);
err_unreg_tty:
	tty_unregister_driver(tty_drv);
err_free_tty:
	put_tty_driver(tty_drv);

	return result;
}

module_init(ifx_spi_init);
module_exit(ifx_spi_exit);

MODULE_AUTHOR("Intel");
MODULE_DESCRIPTION("IFX6x60 spi driver");
MODULE_LICENSE("GPL");
MODULE_INFO(Version, "0.1-IFX6x60");