aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wimax/i2400m/control.c
blob: 0f58418748aa96660ac8aedc2878e1d7d735fc24 (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
/*
 * Intel Wireless WiMAX Connection 2400m
 * Miscellaneous control functions for managing the device
 *
 *
 * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Intel Corporation <linux-wimax@intel.com>
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *  - Initial implementation
 *
 * This is a collection of functions used to control the device (plus
 * a few helpers).
 *
 * There are utilities for handling TLV buffers, hooks on the device's
 * reports to act on device changes of state [i2400m_report_hook()],
 * on acks to commands [i2400m_msg_ack_hook()], a helper for sending
 * commands to the device and blocking until a reply arrives
 * [i2400m_msg_to_dev()], a few high level commands for manipulating
 * the device state, powersving mode and configuration plus the
 * routines to setup the device once communication is stablished with
 * it [i2400m_dev_initialize()].
 *
 * ROADMAP
 *
 * i2400m_dev_initalize()       Called by i2400m_dev_start()
 *   i2400m_set_init_config()
 *   i2400m_cmd_get_state()
 * i2400m_dev_shutdown()        Called by i2400m_dev_stop()
 *   i2400m->bus_reset()
 *
 * i2400m_{cmd,get,set}_*()
 *   i2400m_msg_to_dev()
 *   i2400m_msg_check_status()
 *
 * i2400m_report_hook()         Called on reception of an event
 *   i2400m_report_state_hook()
 *     i2400m_tlv_buffer_walk()
 *     i2400m_tlv_match()
 *     i2400m_report_tlv_system_state()
 *     i2400m_report_tlv_rf_switches_status()
 *     i2400m_report_tlv_media_status()
 *   i2400m_cmd_enter_powersave()
 *
 * i2400m_msg_ack_hook()        Called on reception of a reply to a
 *                              command, get or set
 */

#include <stdarg.h>
#include "i2400m.h"
#include <linux/kernel.h>
#include <linux/wimax/i2400m.h>


#define D_SUBMODULE control
#include "debug-levels.h"


/*
 * Return if a TLV is of a give type and size
 *
 * @tlv_hdr: pointer to the TLV
 * @tlv_type: type of the TLV we are looking for
 * @tlv_size: expected size of the TLV we are looking for (if -1,
 *            don't check the size). This includes the header
 * Returns: 0 if the TLV matches
 *          < 0 if it doesn't match at all
 *          > 0 total TLV + payload size, if the type matches, but not
 *              the size
 */
static
ssize_t i2400m_tlv_match(const struct i2400m_tlv_hdr *tlv,
		     enum i2400m_tlv tlv_type, ssize_t tlv_size)
{
	if (le16_to_cpu(tlv->type) != tlv_type)	/* Not our type? skip */
		return -1;
	if (tlv_size != -1
	    && le16_to_cpu(tlv->length) + sizeof(*tlv) != tlv_size) {
		size_t size = le16_to_cpu(tlv->length) + sizeof(*tlv);
		printk(KERN_WARNING "W: tlv type 0x%x mismatched because of "
		       "size (got %zu vs %zu expected)\n",
		       tlv_type, size, tlv_size);
		return size;
	}
	return 0;
}


/*
 * Given a buffer of TLVs, iterate over them
 *
 * @i2400m: device instance
 * @tlv_buf: pointer to the beginning of the TLV buffer
 * @buf_size: buffer size in bytes
 * @tlv_pos: seek position; this is assumed to be a pointer returned
 *           by i2400m_tlv_buffer_walk() [and thus, validated]. The
 *           TLV returned will be the one following this one.
 *
 * Usage:
 *
 * tlv_itr = NULL;
 * while (tlv_itr = i2400m_tlv_buffer_walk(i2400m, buf, size, tlv_itr))  {
 *         ...
 *         // Do stuff with tlv_itr, DON'T MODIFY IT
 *         ...
 * }
 */
static
const struct i2400m_tlv_hdr *i2400m_tlv_buffer_walk(
	struct i2400m *i2400m,
	const void *tlv_buf, size_t buf_size,
	const struct i2400m_tlv_hdr *tlv_pos)
{
	struct device *dev = i2400m_dev(i2400m);
	const struct i2400m_tlv_hdr *tlv_top = tlv_buf + buf_size;
	size_t offset, length, avail_size;
	unsigned type;

	if (tlv_pos == NULL)	/* Take the first one? */
		tlv_pos = tlv_buf;
	else			/* Nope, the next one */
		tlv_pos = (void *) tlv_pos
			+ le16_to_cpu(tlv_pos->length) + sizeof(*tlv_pos);
	if (tlv_pos == tlv_top) {	/* buffer done */
		tlv_pos = NULL;
		goto error_beyond_end;
	}
	if (tlv_pos > tlv_top) {
		tlv_pos = NULL;
		WARN_ON(1);
		goto error_beyond_end;
	}
	offset = (void *) tlv_pos - (void *) tlv_buf;
	avail_size = buf_size - offset;
	if (avail_size < sizeof(*tlv_pos)) {
		dev_err(dev, "HW BUG? tlv_buf %p [%zu bytes], tlv @%zu: "
			"short header\n", tlv_buf, buf_size, offset);
		goto error_short_header;
	}
	type = le16_to_cpu(tlv_pos->type);
	length = le16_to_cpu(tlv_pos->length);
	if (avail_size < sizeof(*tlv_pos) + length) {
		dev_err(dev, "HW BUG? tlv_buf %p [%zu bytes], "
			"tlv type 0x%04x @%zu: "
			"short data (%zu bytes vs %zu needed)\n",
			tlv_buf, buf_size, type, offset, avail_size,
			sizeof(*tlv_pos) + length);
		goto error_short_header;
	}
error_short_header:
error_beyond_end:
	return tlv_pos;
}


/*
 * Find a TLV in a buffer of sequential TLVs
 *
 * @i2400m: device descriptor
 * @tlv_hdr: pointer to the first TLV in the sequence
 * @size: size of the buffer in bytes; all TLVs are assumed to fit
 *        fully in the buffer (otherwise we'll complain).
 * @tlv_type: type of the TLV we are looking for
 * @tlv_size: expected size of the TLV we are looking for (if -1,
 *            don't check the size). This includes the header
 *
 * Returns: NULL if the TLV is not found, otherwise a pointer to
 *          it. If the sizes don't match, an error is printed and NULL
 *          returned.
 */
static
const struct i2400m_tlv_hdr *i2400m_tlv_find(
	struct i2400m *i2400m,
	const struct i2400m_tlv_hdr *tlv_hdr, size_t size,
	enum i2400m_tlv tlv_type, ssize_t tlv_size)
{
	ssize_t match;
	struct device *dev = i2400m_dev(i2400m);
	const struct i2400m_tlv_hdr *tlv = NULL;
	while ((tlv = i2400m_tlv_buffer_walk(i2400m, tlv_hdr, size, tlv))) {
		match = i2400m_tlv_match(tlv, tlv_type, tlv_size);
		if (match == 0)		/* found it :) */
			break;
		if (match > 0)
			dev_warn(dev, "TLV type 0x%04x found with size "
				 "mismatch (%zu vs %zu needed)\n",
				 tlv_type, match, tlv_size);
	}
	return tlv;
}


static const struct
{
	char *msg;
	int errno;
} ms_to_errno[I2400M_MS_MAX] = {
	[I2400M_MS_DONE_OK] = { "", 0 },
	[I2400M_MS_DONE_IN_PROGRESS] = { "", 0 },
	[I2400M_MS_INVALID_OP] = { "invalid opcode", -ENOSYS },
	[I2400M_MS_BAD_STATE] = { "invalid state", -EILSEQ },
	[I2400M_MS_ILLEGAL_VALUE] = { "illegal value", -EINVAL },
	[I2400M_MS_MISSING_PARAMS] = { "missing parameters", -ENOMSG },
	[I2400M_MS_VERSION_ERROR] = { "bad version", -EIO },
	[I2400M_MS_ACCESSIBILITY_ERROR] = { "accesibility error", -EIO },
	[I2400M_MS_BUSY] = { "busy", -EBUSY },
	[I2400M_MS_CORRUPTED_TLV] = { "corrupted TLV", -EILSEQ },
	[I2400M_MS_UNINITIALIZED] = { "not unitialized", -EILSEQ },
	[I2400M_MS_UNKNOWN_ERROR] = { "unknown error", -EIO },
	[I2400M_MS_PRODUCTION_ERROR] = { "production error", -EIO },
	[I2400M_MS_NO_RF] = { "no RF", -EIO },
	[I2400M_MS_NOT_READY_FOR_POWERSAVE] =
		{ "not ready for powersave", -EACCES },
	[I2400M_MS_THERMAL_CRITICAL] = { "thermal critical", -EL3HLT },
};


/*
 * i2400m_msg_check_status - translate a message's status code
 *
 * @i2400m: device descriptor
 * @l3l4_hdr: message header
 * @strbuf: buffer to place a formatted error message (unless NULL).
 * @strbuf_size: max amount of available space; larger messages will
 * be truncated.
 *
 * Returns: errno code corresponding to the status code in @l3l4_hdr
 *          and a message in @strbuf describing the error.
 */
int i2400m_msg_check_status(const struct i2400m_l3l4_hdr *l3l4_hdr,
			    char *strbuf, size_t strbuf_size)
{
	int result;
	enum i2400m_ms status = le16_to_cpu(l3l4_hdr->status);
	const char *str;

	if (status == 0)
		return 0;
	if (status > ARRAY_SIZE(ms_to_errno)) {
		str = "unknown status code";
		result = -EBADR;
	} else {
		str = ms_to_errno[status].msg;
		result = ms_to_errno[status].errno;
	}
	if (strbuf)
		snprintf(strbuf, strbuf_size, "%s (%d)", str, status);
	return result;
}


/*
 * Act on a TLV System State reported by the device
 *
 * @i2400m: device descriptor
 * @ss: validated System State TLV
 */
static
void i2400m_report_tlv_system_state(struct i2400m *i2400m,
				    const struct i2400m_tlv_system_state *ss)
{
	struct device *dev = i2400m_dev(i2400m);
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	enum i2400m_system_state i2400m_state = le32_to_cpu(ss->state);

	d_fnstart(3, dev, "(i2400m %p ss %p [%u])\n", i2400m, ss, i2400m_state);

	if (unlikely(i2400m->ready == 0))	/* act if up */
		goto out;
	if (i2400m->state != i2400m_state) {
		i2400m->state = i2400m_state;
		wake_up_all(&i2400m->state_wq);
	}
	switch (i2400m_state) {
	case I2400M_SS_UNINITIALIZED:
	case I2400M_SS_INIT:
	case I2400M_SS_CONFIG:
	case I2400M_SS_PRODUCTION:
		wimax_state_change(wimax_dev, WIMAX_ST_UNINITIALIZED);
		break;

	case I2400M_SS_RF_OFF:
	case I2400M_SS_RF_SHUTDOWN:
		wimax_state_change(wimax_dev, WIMAX_ST_RADIO_OFF);
		break;

	case I2400M_SS_READY:
	case I2400M_SS_STANDBY:
	case I2400M_SS_SLEEPACTIVE:
		wimax_state_change(wimax_dev, WIMAX_ST_READY);
		break;

	case I2400M_SS_CONNECTING:
	case I2400M_SS_WIMAX_CONNECTED:
		wimax_state_change(wimax_dev, WIMAX_ST_READY);
		break;

	case I2400M_SS_SCAN:
	case I2400M_SS_OUT_OF_ZONE:
		wimax_state_change(wimax_dev, WIMAX_ST_SCANNING);
		break;

	case I2400M_SS_IDLE:
		d_printf(1, dev, "entering BS-negotiated idle mode\n");
	case I2400M_SS_DISCONNECTING:
	case I2400M_SS_DATA_PATH_CONNECTED:
		wimax_state_change(wimax_dev, WIMAX_ST_CONNECTED);
		break;

	default:
		/* Huh? just in case, shut it down */
		dev_err(dev, "HW BUG? unknown state %u: shutting down\n",
			i2400m_state);
		i2400m->bus_reset(i2400m, I2400M_RT_WARM);
		break;
	};
out:
	d_fnend(3, dev, "(i2400m %p ss %p [%u]) = void\n",
		i2400m, ss, i2400m_state);
}


/*
 * Parse and act on a TLV Media Status sent by the device
 *
 * @i2400m: device descriptor
 * @ms: validated Media Status TLV
 *
 * This will set the carrier up on down based on the device's link
 * report. This is done asides of what the WiMAX stack does based on
 * the device's state as sometimes we need to do a link-renew (the BS
 * wants us to renew a DHCP lease, for example).
 *
 * In fact, doc says that everytime we get a link-up, we should do a
 * DHCP negotiation...
 */
static
void i2400m_report_tlv_media_status(struct i2400m *i2400m,
				    const struct i2400m_tlv_media_status *ms)
{
	struct device *dev = i2400m_dev(i2400m);
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	struct net_device *net_dev = wimax_dev->net_dev;
	enum i2400m_media_status status = le32_to_cpu(ms->media_status);

	d_fnstart(3, dev, "(i2400m %p ms %p [%u])\n", i2400m, ms, status);

	if (unlikely(i2400m->ready == 0))	/* act if up */
		goto out;
	switch (status) {
	case I2400M_MEDIA_STATUS_LINK_UP:
		netif_carrier_on(net_dev);
		break;
	case I2400M_MEDIA_STATUS_LINK_DOWN:
		netif_carrier_off(net_dev);
		break;
	/*
	 * This is the network telling us we need to retrain the DHCP
	 * lease -- so far, we are trusting the WiMAX Network Service
	 * in user space to pick this up and poke the DHCP client.
	 */
	case I2400M_MEDIA_STATUS_LINK_RENEW:
		netif_carrier_on(net_dev);
		break;
	default:
		dev_err(dev, "HW BUG? unknown media status %u\n",
			status);
	};
out:
	d_fnend(3, dev, "(i2400m %p ms %p [%u]) = void\n",
		i2400m, ms, status);
}


/*
 * Parse a 'state report' and extract carrier on/off information
 *
 * @i2400m: device descriptor
 * @l3l4_hdr: pointer to message; it has been already validated for
 *            consistent size.
 * @size: size of the message (header + payload). The header length
 *        declaration is assumed to be congruent with @size (as in
 *        sizeof(*l3l4_hdr) + l3l4_hdr->length == size)
 *
 * Extract from the report state the system state TLV and infer from
 * there if we have a carrier or not. Update our local state and tell
 * netdev.
 *
 * When setting the carrier, it's fine to set OFF twice (for example),
 * as netif_carrier_off() will not generate two OFF events (just on
 * the transitions).
 */
static
void i2400m_report_state_hook(struct i2400m *i2400m,
			      const struct i2400m_l3l4_hdr *l3l4_hdr,
			      size_t size, const char *tag)
{
	struct device *dev = i2400m_dev(i2400m);
	const struct i2400m_tlv_hdr *tlv;
	const struct i2400m_tlv_system_state *ss;
	const struct i2400m_tlv_rf_switches_status *rfss;
	const struct i2400m_tlv_media_status *ms;
	size_t tlv_size = le16_to_cpu(l3l4_hdr->length);

	d_fnstart(4, dev, "(i2400m %p, l3l4_hdr %p, size %zu, %s)\n",
		  i2400m, l3l4_hdr, size, tag);
	tlv = NULL;

	while ((tlv = i2400m_tlv_buffer_walk(i2400m, &l3l4_hdr->pl,
					     tlv_size, tlv))) {
		if (0 == i2400m_tlv_match(tlv, I2400M_TLV_SYSTEM_STATE,
					  sizeof(*ss))) {
			ss = container_of(tlv, typeof(*ss), hdr);
			d_printf(2, dev, "%s: system state TLV "
				 "found (0x%04x), state 0x%08x\n",
				 tag, I2400M_TLV_SYSTEM_STATE,
				 le32_to_cpu(ss->state));
			i2400m_report_tlv_system_state(i2400m, ss);
		}
		if (0 == i2400m_tlv_match(tlv, I2400M_TLV_RF_STATUS,
					  sizeof(*rfss))) {
			rfss = container_of(tlv, typeof(*rfss), hdr);
			d_printf(2, dev, "%s: RF status TLV "
				 "found (0x%04x), sw 0x%02x hw 0x%02x\n",
				 tag, I2400M_TLV_RF_STATUS,
				 le32_to_cpu(rfss->sw_rf_switch),
				 le32_to_cpu(rfss->hw_rf_switch));
			i2400m_report_tlv_rf_switches_status(i2400m, rfss);
		}
		if (0 == i2400m_tlv_match(tlv, I2400M_TLV_MEDIA_STATUS,
					  sizeof(*ms))) {
			ms = container_of(tlv, typeof(*ms), hdr);
			d_printf(2, dev, "%s: Media Status TLV: %u\n",
				 tag, le32_to_cpu(ms->media_status));
			i2400m_report_tlv_media_status(i2400m, ms);
		}
	}
	d_fnend(4, dev, "(i2400m %p, l3l4_hdr %p, size %zu, %s) = void\n",
		i2400m, l3l4_hdr, size, tag);
}


/*
 * i2400m_report_hook - (maybe) act on a report
 *
 * @i2400m: device descriptor
 * @l3l4_hdr: pointer to message; it has been already validated for
 *            consistent size.
 * @size: size of the message (header + payload). The header length
 *        declaration is assumed to be congruent with @size (as in
 *        sizeof(*l3l4_hdr) + l3l4_hdr->length == size)
 *
 * Extract information we might need (like carrien on/off) from a
 * device report.
 */
void i2400m_report_hook(struct i2400m *i2400m,
			const struct i2400m_l3l4_hdr *l3l4_hdr, size_t size)
{
	struct device *dev = i2400m_dev(i2400m);
	unsigned msg_type;

	d_fnstart(3, dev, "(i2400m %p l3l4_hdr %p size %zu)\n",
		  i2400m, l3l4_hdr, size);
	/* Chew on the message, we might need some information from
	 * here */
	msg_type = le16_to_cpu(l3l4_hdr->type);
	switch (msg_type) {
	case I2400M_MT_REPORT_STATE:	/* carrier detection... */
		i2400m_report_state_hook(i2400m,
					 l3l4_hdr, size, "REPORT STATE");
		break;
	/* If the device is ready for power save, then ask it to do
	 * it. */
	case I2400M_MT_REPORT_POWERSAVE_READY:	/* zzzzz */
		if (l3l4_hdr->status == cpu_to_le16(I2400M_MS_DONE_OK)) {
			d_printf(1, dev, "ready for powersave, requesting\n");
			i2400m_cmd_enter_powersave(i2400m);
		}
		break;
	};
	d_fnend(3, dev, "(i2400m %p l3l4_hdr %p size %zu) = void\n",
		i2400m, l3l4_hdr, size);
}


/*
 * i2400m_msg_ack_hook - process cmd/set/get ack for internal status
 *
 * @i2400m: device descriptor
 * @l3l4_hdr: pointer to message; it has been already validated for
 *            consistent size.
 * @size: size of the message
 *
 * Extract information we might need from acks to commands and act on
 * it. This is akin to i2400m_report_hook(). Note most of this
 * processing should be done in the function that calls the
 * command. This is here for some cases where it can't happen...
 */
void i2400m_msg_ack_hook(struct i2400m *i2400m,
			 const struct i2400m_l3l4_hdr *l3l4_hdr, size_t size)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	unsigned ack_type, ack_status;
	char strerr[32];

	/* Chew on the message, we might need some information from
	 * here */
	ack_type = le16_to_cpu(l3l4_hdr->type);
	ack_status = le16_to_cpu(l3l4_hdr->status);
	switch (ack_type) {
	case I2400M_MT_CMD_ENTER_POWERSAVE:
		/* This is just left here for the sake of example, as
		 * the processing is done somewhere else. */
		if (0) {
			result = i2400m_msg_check_status(
				l3l4_hdr, strerr, sizeof(strerr));
			if (result >= 0)
				d_printf(1, dev, "ready for power save: %zd\n",
					 size);
		}
		break;
	};
	return;
}


/*
 * i2400m_msg_size_check() - verify message size and header are congruent
 *
 * It is ok if the total message size is larger than the expected
 * size, as there can be padding.
 */
int i2400m_msg_size_check(struct i2400m *i2400m,
			  const struct i2400m_l3l4_hdr *l3l4_hdr,
			  size_t msg_size)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	size_t expected_size;
	d_fnstart(4, dev, "(i2400m %p l3l4_hdr %p msg_size %zu)\n",
		  i2400m, l3l4_hdr, msg_size);
	if (msg_size < sizeof(*l3l4_hdr)) {
		dev_err(dev, "bad size for message header "
			"(expected at least %zu, got %zu)\n",
			(size_t) sizeof(*l3l4_hdr), msg_size);
		result = -EIO;
		goto error_hdr_size;
	}
	expected_size = le16_to_cpu(l3l4_hdr->length) + sizeof(*l3l4_hdr);
	if (msg_size < expected_size) {
		dev_err(dev, "bad size for message code 0x%04x (expected %zu, "
			"got %zu)\n", le16_to_cpu(l3l4_hdr->type),
			expected_size, msg_size);
		result = -EIO;
	} else
		result = 0;
error_hdr_size:
	d_fnend(4, dev,
		"(i2400m %p l3l4_hdr %p msg_size %zu) = %d\n",
		i2400m, l3l4_hdr, msg_size, result);
	return result;
}



/*
 * Cancel a wait for a command ACK
 *
 * @i2400m: device descriptor
 * @code: [negative] errno code to cancel with (don't use
 *     -EINPROGRESS)
 *
 * If there is an ack already filled out, free it.
 */
void i2400m_msg_to_dev_cancel_wait(struct i2400m *i2400m, int code)
{
	struct sk_buff *ack_skb;
	unsigned long flags;

	spin_lock_irqsave(&i2400m->rx_lock, flags);
	ack_skb = i2400m->ack_skb;
	if (ack_skb && !IS_ERR(ack_skb))
		kfree_skb(ack_skb);
	i2400m->ack_skb = ERR_PTR(code);
	spin_unlock_irqrestore(&i2400m->rx_lock, flags);
}


/**
 * i2400m_msg_to_dev - Send a control message to the device and get a response
 *
 * @i2400m: device descriptor
 *
 * @msg_skb: an skb  *
 *
 * @buf: pointer to the buffer containing the message to be sent; it
 *           has to start with a &struct i2400M_l3l4_hdr and then
 *           followed by the payload. Once this function returns, the
 *           buffer can be reused.
 *
 * @buf_len: buffer size
 *
 * Returns:
 *
 * Pointer to skb containing the ack message. You need to check the
 * pointer with IS_ERR(), as it might be an error code. Error codes
 * could happen because:
 *
 *  - the message wasn't formatted correctly
 *  - couldn't send the message
 *  - failed waiting for a response
 *  - the ack message wasn't formatted correctly
 *
 * The returned skb has been allocated with wimax_msg_to_user_alloc(),
 * it contains the reponse in a netlink attribute and is ready to be
 * passed up to user space with wimax_msg_to_user_send(). To access
 * the payload and its length, use wimax_msg_{data,len}() on the skb.
 *
 * The skb has to be freed with kfree_skb() once done.
 *
 * Description:
 *
 * This function delivers a message/command to the device and waits
 * for an ack to be received. The format is described in
 * linux/wimax/i2400m.h. In summary, a command/get/set is followed by an
 * ack.
 *
 * This function will not check the ack status, that's left up to the
 * caller.  Once done with the ack skb, it has to be kfree_skb()ed.
 *
 * The i2400m handles only one message at the same time, thus we need
 * the mutex to exclude other players.
 *
 * We write the message and then wait for an answer to come back. The
 * RX path intercepts control messages and handles them in
 * i2400m_rx_ctl(). Reports (notifications) are (maybe) processed
 * locally and then forwarded (as needed) to user space on the WiMAX
 * stack message pipe. Acks are saved and passed back to us through an
 * skb in i2400m->ack_skb which is ready to be given to generic
 * netlink if need be.
 */
struct sk_buff *i2400m_msg_to_dev(struct i2400m *i2400m,
				  const void *buf, size_t buf_len)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	const struct i2400m_l3l4_hdr *msg_l3l4_hdr;
	struct sk_buff *ack_skb;
	const struct i2400m_l3l4_hdr *ack_l3l4_hdr;
	size_t ack_len;
	int ack_timeout;
	unsigned msg_type;
	unsigned long flags;

	d_fnstart(3, dev, "(i2400m %p buf %p len %zu)\n",
		  i2400m, buf, buf_len);

	if (i2400m->boot_mode)
		return ERR_PTR(-ENODEV);

	msg_l3l4_hdr = buf;
	/* Check msg & payload consistency */
	result = i2400m_msg_size_check(i2400m, msg_l3l4_hdr, buf_len);
	if (result < 0)
		goto error_bad_msg;
	msg_type = le16_to_cpu(msg_l3l4_hdr->type);
	d_printf(1, dev, "CMD/GET/SET 0x%04x %zu bytes\n",
		 msg_type, buf_len);
	d_dump(2, dev, buf, buf_len);

	/* Setup the completion, ack_skb ("we are waiting") and send
	 * the message to the device */
	mutex_lock(&i2400m->msg_mutex);
	spin_lock_irqsave(&i2400m->rx_lock, flags);
	i2400m->ack_skb = ERR_PTR(-EINPROGRESS);
	spin_unlock_irqrestore(&i2400m->rx_lock, flags);
	init_completion(&i2400m->msg_completion);
	result = i2400m_tx(i2400m, buf, buf_len, I2400M_PT_CTRL);
	if (result < 0) {
		dev_err(dev, "can't send message 0x%04x: %d\n",
			le16_to_cpu(msg_l3l4_hdr->type), result);
		goto error_tx;
	}

	/* Some commands take longer to execute because of crypto ops,
	 * so we give them some more leeway on timeout */
	switch (msg_type) {
	case I2400M_MT_GET_TLS_OPERATION_RESULT:
	case I2400M_MT_CMD_SEND_EAP_RESPONSE:
		ack_timeout = 5 * HZ;
		break;
	default:
		ack_timeout = HZ;
	};

	if (unlikely(i2400m->trace_msg_from_user))
		wimax_msg(&i2400m->wimax_dev, "echo", buf, buf_len, GFP_KERNEL);
	/* The RX path in rx.c will put any response for this message
	 * in i2400m->ack_skb and wake us up. If we cancel the wait,
	 * we need to change the value of i2400m->ack_skb to something
	 * not -EINPROGRESS so RX knows there is no one waiting. */
	result = wait_for_completion_interruptible_timeout(
		&i2400m->msg_completion, ack_timeout);
	if (result == 0) {
		dev_err(dev, "timeout waiting for reply to message 0x%04x\n",
			msg_type);
		result = -ETIMEDOUT;
		i2400m_msg_to_dev_cancel_wait(i2400m, result);
		goto error_wait_for_completion;
	} else if (result < 0) {
		dev_err(dev, "error waiting for reply to message 0x%04x: %d\n",
			msg_type, result);
		i2400m_msg_to_dev_cancel_wait(i2400m, result);
		goto error_wait_for_completion;
	}

	/* Pull out the ack data from i2400m->ack_skb -- see if it is
	 * an error and act accordingly */
	spin_lock_irqsave(&i2400m->rx_lock, flags);
	ack_skb = i2400m->ack_skb;
	if (IS_ERR(ack_skb))
		result = PTR_ERR(ack_skb);
	else
		result = 0;
	i2400m->ack_skb = NULL;
	spin_unlock_irqrestore(&i2400m->rx_lock, flags);
	if (result < 0)
		goto error_ack_status;
	ack_l3l4_hdr = wimax_msg_data_len(ack_skb, &ack_len);

	/* Check the ack and deliver it if it is ok */
	if (unlikely(i2400m->trace_msg_from_user))
		wimax_msg(&i2400m->wimax_dev, "echo",
			  ack_l3l4_hdr, ack_len, GFP_KERNEL);
	result = i2400m_msg_size_check(i2400m, ack_l3l4_hdr, ack_len);
	if (result < 0) {
		dev_err(dev, "HW BUG? reply to message 0x%04x: %d\n",
			msg_type, result);
		goto error_bad_ack_len;
	}
	if (msg_type != le16_to_cpu(ack_l3l4_hdr->type)) {
		dev_err(dev, "HW BUG? bad reply 0x%04x to message 0x%04x\n",
			le16_to_cpu(ack_l3l4_hdr->type), msg_type);
		result = -EIO;
		goto error_bad_ack_type;
	}
	i2400m_msg_ack_hook(i2400m, ack_l3l4_hdr, ack_len);
	mutex_unlock(&i2400m->msg_mutex);
	d_fnend(3, dev, "(i2400m %p buf %p len %zu) = %p\n",
		i2400m, buf, buf_len, ack_skb);
	return ack_skb;

error_bad_ack_type:
error_bad_ack_len:
	kfree_skb(ack_skb);
error_ack_status:
error_wait_for_completion:
error_tx:
	mutex_unlock(&i2400m->msg_mutex);
error_bad_msg:
	d_fnend(3, dev, "(i2400m %p buf %p len %zu) = %d\n",
		i2400m, buf, buf_len, result);
	return ERR_PTR(result);
}


/*
 * Definitions for the Enter Power Save command
 *
 * The Enter Power Save command requests the device to go into power
 * saving mode. The device will ack or nak the command depending on it
 * being ready for it. If it acks, we tell the USB subsystem to
 *
 * As well, the device might request to go into power saving mode by
 * sending a report (REPORT_POWERSAVE_READY), in which case, we issue
 * this command. The hookups in the RX coder allow
 */
enum {
	I2400M_WAKEUP_ENABLED  = 0x01,
	I2400M_WAKEUP_DISABLED = 0x02,
	I2400M_TLV_TYPE_WAKEUP_MODE = 144,
};

struct i2400m_cmd_enter_power_save {
	struct i2400m_l3l4_hdr hdr;
	struct i2400m_tlv_hdr tlv;
	__le32 val;
} __attribute__((packed));


/*
 * Request entering power save
 *
 * This command is (mainly) executed when the device indicates that it
 * is ready to go into powersave mode via a REPORT_POWERSAVE_READY.
 */
int i2400m_cmd_enter_powersave(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_cmd_enter_power_save *cmd;
	char strerr[32];

	result = -ENOMEM;
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->hdr.type = cpu_to_le16(I2400M_MT_CMD_ENTER_POWERSAVE);
	cmd->hdr.length = cpu_to_le16(sizeof(*cmd) - sizeof(cmd->hdr));
	cmd->hdr.version = cpu_to_le16(I2400M_L3L4_VERSION);
	cmd->tlv.type = cpu_to_le16(I2400M_TLV_TYPE_WAKEUP_MODE);
	cmd->tlv.length = cpu_to_le16(sizeof(cmd->val));
	cmd->val = cpu_to_le32(I2400M_WAKEUP_ENABLED);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	result = PTR_ERR(ack_skb);
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'Enter power save' command: %d\n",
			result);
		goto error_msg_to_dev;
	}
	result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
					 strerr, sizeof(strerr));
	if (result == -EACCES)
		d_printf(1, dev, "Cannot enter power save mode\n");
	else if (result < 0)
		dev_err(dev, "'Enter power save' (0x%04x) command failed: "
			"%d - %s\n", I2400M_MT_CMD_ENTER_POWERSAVE,
			result, strerr);
	else
		d_printf(1, dev, "device ready to power save\n");
	kfree_skb(ack_skb);
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_cmd_enter_powersave);


/*
 * Definitions for getting device information
 */
enum {
	I2400M_TLV_DETAILED_DEVICE_INFO = 140
};

/**
 * i2400m_get_device_info - Query the device for detailed device information
 *
 * @i2400m: device descriptor
 *
 * Returns: an skb whose skb->data points to a 'struct
 *    i2400m_tlv_detailed_device_info'. When done, kfree_skb() it. The
 *    skb is *guaranteed* to contain the whole TLV data structure.
 *
 *    On error, IS_ERR(skb) is true and ERR_PTR(skb) is the error
 *    code.
 */
struct sk_buff *i2400m_get_device_info(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_l3l4_hdr *cmd;
	const struct i2400m_l3l4_hdr *ack;
	size_t ack_len;
	const struct i2400m_tlv_hdr *tlv;
	const struct i2400m_tlv_detailed_device_info *ddi;
	char strerr[32];

	ack_skb = ERR_PTR(-ENOMEM);
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->type = cpu_to_le16(I2400M_MT_GET_DEVICE_INFO);
	cmd->length = 0;
	cmd->version = cpu_to_le16(I2400M_L3L4_VERSION);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'get device info' command: %ld\n",
			PTR_ERR(ack_skb));
		goto error_msg_to_dev;
	}
	ack = wimax_msg_data_len(ack_skb, &ack_len);
	result = i2400m_msg_check_status(ack, strerr, sizeof(strerr));
	if (result < 0) {
		dev_err(dev, "'get device info' (0x%04x) command failed: "
			"%d - %s\n", I2400M_MT_GET_DEVICE_INFO, result,
			strerr);
		goto error_cmd_failed;
	}
	tlv = i2400m_tlv_find(i2400m, ack->pl, ack_len - sizeof(*ack),
			      I2400M_TLV_DETAILED_DEVICE_INFO, sizeof(*ddi));
	if (tlv == NULL) {
		dev_err(dev, "GET DEVICE INFO: "
			"detailed device info TLV not found (0x%04x)\n",
			I2400M_TLV_DETAILED_DEVICE_INFO);
		result = -EIO;
		goto error_no_tlv;
	}
	skb_pull(ack_skb, (void *) tlv - (void *) ack_skb->data);
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return ack_skb;

error_no_tlv:
error_cmd_failed:
	kfree_skb(ack_skb);
	kfree(cmd);
	return ERR_PTR(result);
}


/* Firmware interface versions we support */
enum {
	I2400M_HDIv_MAJOR = 9,
	I2400M_HDIv_MINOR = 1,
	I2400M_HDIv_MINOR_2 = 2,
};


/**
 * i2400m_firmware_check - check firmware versions are compatible with
 * the driver
 *
 * @i2400m: device descriptor
 *
 * Returns: 0 if ok, < 0 errno code an error and a message in the
 *    kernel log.
 *
 * Long function, but quite simple; first chunk launches the command
 * and double checks the reply for the right TLV. Then we process the
 * TLV (where the meat is).
 *
 * Once we process the TLV that gives us the firmware's interface
 * version, we encode it and save it in i2400m->fw_version for future
 * reference.
 */
int i2400m_firmware_check(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_l3l4_hdr *cmd;
	const struct i2400m_l3l4_hdr *ack;
	size_t ack_len;
	const struct i2400m_tlv_hdr *tlv;
	const struct i2400m_tlv_l4_message_versions *l4mv;
	char strerr[32];
	unsigned major, minor, branch;

	result = -ENOMEM;
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->type = cpu_to_le16(I2400M_MT_GET_LM_VERSION);
	cmd->length = 0;
	cmd->version = cpu_to_le16(I2400M_L3L4_VERSION);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	if (IS_ERR(ack_skb)) {
		result = PTR_ERR(ack_skb);
		dev_err(dev, "Failed to issue 'get lm version' command: %-d\n",
			result);
		goto error_msg_to_dev;
	}
	ack = wimax_msg_data_len(ack_skb, &ack_len);
	result = i2400m_msg_check_status(ack, strerr, sizeof(strerr));
	if (result < 0) {
		dev_err(dev, "'get lm version' (0x%04x) command failed: "
			"%d - %s\n", I2400M_MT_GET_LM_VERSION, result,
			strerr);
		goto error_cmd_failed;
	}
	tlv = i2400m_tlv_find(i2400m, ack->pl, ack_len - sizeof(*ack),
			      I2400M_TLV_L4_MESSAGE_VERSIONS, sizeof(*l4mv));
	if (tlv == NULL) {
		dev_err(dev, "get lm version: TLV not found (0x%04x)\n",
			I2400M_TLV_L4_MESSAGE_VERSIONS);
		result = -EIO;
		goto error_no_tlv;
	}
	l4mv = container_of(tlv, typeof(*l4mv), hdr);
	major = le16_to_cpu(l4mv->major);
	minor = le16_to_cpu(l4mv->minor);
	branch = le16_to_cpu(l4mv->branch);
	result = -EINVAL;
	if (major != I2400M_HDIv_MAJOR) {
		dev_err(dev, "unsupported major fw version "
			"%u.%u.%u\n", major, minor, branch);
		goto error_bad_major;
	}
	result = 0;
	if (minor < I2400M_HDIv_MINOR_2 && minor > I2400M_HDIv_MINOR)
		dev_warn(dev, "untested minor fw version %u.%u.%u\n",
			 major, minor, branch);
	/* Yes, we ignore the branch -- we don't have to track it */
	i2400m->fw_version = major << 16 | minor;
	dev_info(dev, "firmware interface version %u.%u.%u\n",
		 major, minor, branch);
error_bad_major:
error_no_tlv:
error_cmd_failed:
	kfree_skb(ack_skb);
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return result;
}


/*
 * Send an DoExitIdle command to the device to ask it to go out of
 * basestation-idle mode.
 *
 * @i2400m: device descriptor
 *
 * This starts a renegotiation with the basestation that might involve
 * another crypto handshake with user space.
 *
 * Returns: 0 if ok, < 0 errno code on error.
 */
int i2400m_cmd_exit_idle(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_l3l4_hdr *cmd;
	char strerr[32];

	result = -ENOMEM;
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->type = cpu_to_le16(I2400M_MT_CMD_EXIT_IDLE);
	cmd->length = 0;
	cmd->version = cpu_to_le16(I2400M_L3L4_VERSION);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	result = PTR_ERR(ack_skb);
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'exit idle' command: %d\n",
			result);
		goto error_msg_to_dev;
	}
	result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
					 strerr, sizeof(strerr));
	kfree_skb(ack_skb);
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return result;

}


/*
 * Query the device for its state, update the WiMAX stack's idea of it
 *
 * @i2400m: device descriptor
 *
 * Returns: 0 if ok, < 0 errno code on error.
 *
 * Executes a 'Get State' command and parses the returned
 * TLVs.
 *
 * Because this is almost identical to a 'Report State', we use
 * i2400m_report_state_hook() to parse the answer. This will set the
 * carrier state, as well as the RF Kill switches state.
 */
int i2400m_cmd_get_state(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_l3l4_hdr *cmd;
	const struct i2400m_l3l4_hdr *ack;
	size_t ack_len;
	char strerr[32];

	result = -ENOMEM;
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->type = cpu_to_le16(I2400M_MT_GET_STATE);
	cmd->length = 0;
	cmd->version = cpu_to_le16(I2400M_L3L4_VERSION);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'get state' command: %ld\n",
			PTR_ERR(ack_skb));
		result = PTR_ERR(ack_skb);
		goto error_msg_to_dev;
	}
	ack = wimax_msg_data_len(ack_skb, &ack_len);
	result = i2400m_msg_check_status(ack, strerr, sizeof(strerr));
	if (result < 0) {
		dev_err(dev, "'get state' (0x%04x) command failed: "
			"%d - %s\n", I2400M_MT_GET_STATE, result, strerr);
		goto error_cmd_failed;
	}
	i2400m_report_state_hook(i2400m, ack, ack_len - sizeof(*ack),
				 "GET STATE");
	result = 0;
	kfree_skb(ack_skb);
error_cmd_failed:
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_cmd_get_state);


/**
 * Set basic configuration settings
 *
 * @i2400m: device descriptor
 * @args: array of pointers to the TLV headers to send for
 *     configuration (each followed by its payload).
 *     TLV headers and payloads must be properly initialized, with the
 *     right endianess (LE).
 * @arg_size: number of pointers in the @args array
 */
int i2400m_set_init_config(struct i2400m *i2400m,
			   const struct i2400m_tlv_hdr **arg, size_t args)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct i2400m_l3l4_hdr *cmd;
	char strerr[32];
	unsigned argc, argsize, tlv_size;
	const struct i2400m_tlv_hdr *tlv_hdr;
	void *buf, *itr;

	d_fnstart(3, dev, "(i2400m %p arg %p args %zu)\n", i2400m, arg, args);
	result = 0;
	if (args == 0)
		goto none;
	/* Compute the size of all the TLVs, so we can alloc a
	 * contiguous command block to copy them. */
	argsize = 0;
	for (argc = 0; argc < args; argc++) {
		tlv_hdr = arg[argc];
		argsize += sizeof(*tlv_hdr) + le16_to_cpu(tlv_hdr->length);
	}
	WARN_ON(argc >= 9);	/* As per hw spec */

	/* Alloc the space for the command and TLVs*/
	result = -ENOMEM;
	buf = kzalloc(sizeof(*cmd) + argsize, GFP_KERNEL);
	if (buf == NULL)
		goto error_alloc;
	cmd = buf;
	cmd->type = cpu_to_le16(I2400M_MT_SET_INIT_CONFIG);
	cmd->length = cpu_to_le16(argsize);
	cmd->version = cpu_to_le16(I2400M_L3L4_VERSION);

	/* Copy the TLVs */
	itr = buf + sizeof(*cmd);
	for (argc = 0; argc < args; argc++) {
		tlv_hdr = arg[argc];
		tlv_size = sizeof(*tlv_hdr) + le16_to_cpu(tlv_hdr->length);
		memcpy(itr, tlv_hdr, tlv_size);
		itr += tlv_size;
	}

	/* Send the message! */
	ack_skb = i2400m_msg_to_dev(i2400m, buf, sizeof(*cmd) + argsize);
	result = PTR_ERR(ack_skb);
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'init config' command: %d\n",
			result);

		goto error_msg_to_dev;
	}
	result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
					 strerr, sizeof(strerr));
	if (result < 0)
		dev_err(dev, "'init config' (0x%04x) command failed: %d - %s\n",
			I2400M_MT_SET_INIT_CONFIG, result, strerr);
	kfree_skb(ack_skb);
error_msg_to_dev:
	kfree(buf);
error_alloc:
none:
	d_fnend(3, dev, "(i2400m %p arg %p args %zu) = %d\n",
		i2400m, arg, args, result);
	return result;

}
EXPORT_SYMBOL_GPL(i2400m_set_init_config);


/**
 * i2400m_set_idle_timeout - Set the device's idle mode timeout
 *
 * @i2400m: i2400m device descriptor
 *
 * @msecs: milliseconds for the timeout to enter idle mode. Between
 *     100 to 300000 (5m); 0 to disable. In increments of 100.
 *
 * After this @msecs of the link being idle (no data being sent or
 * received), the device will negotiate with the basestation entering
 * idle mode for saving power. The connection is maintained, but
 * getting out of it (done in tx.c) will require some negotiation,
 * possible crypto re-handshake and a possible DHCP re-lease.
 *
 * Only available if fw_version >= 0x00090002.
 *
 * Returns: 0 if ok, < 0 errno code on error.
 */
int i2400m_set_idle_timeout(struct i2400m *i2400m, unsigned msecs)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;
	struct {
		struct i2400m_l3l4_hdr hdr;
		struct i2400m_tlv_config_idle_timeout cit;
	} *cmd;
	const struct i2400m_l3l4_hdr *ack;
	size_t ack_len;
	char strerr[32];

	result = -ENOSYS;
	if (i2400m_le_v1_3(i2400m))
		goto error_alloc;
	result = -ENOMEM;
	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		goto error_alloc;
	cmd->hdr.type = cpu_to_le16(I2400M_MT_GET_STATE);
	cmd->hdr.length = cpu_to_le16(sizeof(*cmd) - sizeof(cmd->hdr));
	cmd->hdr.version = cpu_to_le16(I2400M_L3L4_VERSION);

	cmd->cit.hdr.type =
		cpu_to_le16(I2400M_TLV_CONFIG_IDLE_TIMEOUT);
	cmd->cit.hdr.length = cpu_to_le16(sizeof(cmd->cit.timeout));
	cmd->cit.timeout = cpu_to_le32(msecs);

	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
	if (IS_ERR(ack_skb)) {
		dev_err(dev, "Failed to issue 'set idle timeout' command: "
			"%ld\n", PTR_ERR(ack_skb));
		result = PTR_ERR(ack_skb);
		goto error_msg_to_dev;
	}
	ack = wimax_msg_data_len(ack_skb, &ack_len);
	result = i2400m_msg_check_status(ack, strerr, sizeof(strerr));
	if (result < 0) {
		dev_err(dev, "'set idle timeout' (0x%04x) command failed: "
			"%d - %s\n", I2400M_MT_GET_STATE, result, strerr);
		goto error_cmd_failed;
	}
	result = 0;
	kfree_skb(ack_skb);
error_cmd_failed:
error_msg_to_dev:
	kfree(cmd);
error_alloc:
	return result;
}


/**
 * i2400m_dev_initialize - Initialize the device once communications are ready
 *
 * @i2400m: device descriptor
 *
 * Returns: 0 if ok, < 0 errno code on error.
 *
 * Configures the device to work the way we like it.
 *
 * At the point of this call, the device is registered with the WiMAX
 * and netdev stacks, firmware is uploaded and we can talk to the
 * device normally.
 */
int i2400m_dev_initialize(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_tlv_config_idle_parameters idle_params;
	struct i2400m_tlv_config_idle_timeout idle_timeout;
	struct i2400m_tlv_config_d2h_data_format df;
	struct i2400m_tlv_config_dl_host_reorder dlhr;
	const struct i2400m_tlv_hdr *args[9];
	unsigned argc = 0;

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	/* Disable idle mode? (enabled by default) */
	if (i2400m_idle_mode_disabled) {
		if (i2400m_le_v1_3(i2400m)) {
			idle_params.hdr.type =
				cpu_to_le16(I2400M_TLV_CONFIG_IDLE_PARAMETERS);
			idle_params.hdr.length = cpu_to_le16(
				sizeof(idle_params) - sizeof(idle_params.hdr));
			idle_params.idle_timeout = 0;
			idle_params.idle_paging_interval = 0;
			args[argc++] = &idle_params.hdr;
		} else {
			idle_timeout.hdr.type =
				cpu_to_le16(I2400M_TLV_CONFIG_IDLE_TIMEOUT);
			idle_timeout.hdr.length = cpu_to_le16(
				sizeof(idle_timeout) - sizeof(idle_timeout.hdr));
			idle_timeout.timeout = 0;
			args[argc++] = &idle_timeout.hdr;
		}
	}
	if (i2400m_ge_v1_4(i2400m)) {
		/* Enable extended RX data format? */
		df.hdr.type =
			cpu_to_le16(I2400M_TLV_CONFIG_D2H_DATA_FORMAT);
		df.hdr.length = cpu_to_le16(
			sizeof(df) - sizeof(df.hdr));
		df.format = 1;
		args[argc++] = &df.hdr;

		/* Enable RX data reordering?
		 * (switch flipped in rx.c:i2400m_rx_setup() after fw upload) */
		if (i2400m->rx_reorder) {
			dlhr.hdr.type =
				cpu_to_le16(I2400M_TLV_CONFIG_DL_HOST_REORDER);
			dlhr.hdr.length = cpu_to_le16(
				sizeof(dlhr) - sizeof(dlhr.hdr));
			dlhr.reorder = 1;
			args[argc++] = &dlhr.hdr;
		}
	}
	result = i2400m_set_init_config(i2400m, args, argc);
	if (result < 0)
		goto error;
	/*
	 * Update state: Here it just calls a get state; parsing the
	 * result (System State TLV and RF Status TLV [done in the rx
	 * path hooks]) will set the hardware and software RF-Kill
	 * status.
	 */
	result = i2400m_cmd_get_state(i2400m);
error:
	if (result < 0)
		dev_err(dev, "failed to initialize the device: %d\n", result);
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}


/**
 * i2400m_dev_shutdown - Shutdown a running device
 *
 * @i2400m: device descriptor
 *
 * Gracefully stops the device, moving it to the lowest power
 * consumption state possible.
 */
void i2400m_dev_shutdown(struct i2400m *i2400m)
{
	int result = -ENODEV;
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	result = i2400m->bus_reset(i2400m, I2400M_RT_WARM);
	d_fnend(3, dev, "(i2400m %p) = void [%d]\n", i2400m, result);
	return;
}