aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wimax/i2400m/fw.c
blob: 1d8271f34c3832b35feafeaabe854cad7278e22b (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
/*
 * Intel Wireless WiMAX Connection 2400m
 * Firmware uploader
 *
 *
 * 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>
 * Yanir Lubetkin <yanirx.lubetkin@intel.com>
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *  - Initial implementation
 *
 *
 * THE PROCEDURE
 *
 * (this is decribed for USB, but for SDIO is similar)
 *
 * The 2400m works in two modes: boot-mode or normal mode. In boot
 * mode we can execute only a handful of commands targeted at
 * uploading the firmware and launching it.
 *
 * The 2400m enters boot mode when it is first connected to the
 * system, when it crashes and when you ask it to reboot. There are
 * two submodes of the boot mode: signed and non-signed. Signed takes
 * firmwares signed with a certain private key, non-signed takes any
 * firmware. Normal hardware takes only signed firmware.
 *
 * Upon entrance to boot mode, the device sends a few zero length
 * packets (ZLPs) on the notification endpoint, then a reboot barker
 * (4 le32 words with value I2400M_{S,N}BOOT_BARKER). We ack it by
 * sending the same barker on the bulk out endpoint. The device acks
 * with a reboot ack barker (4 le32 words with value 0xfeedbabe) and
 * then the device is fully rebooted. At this point we can upload the
 * firmware.
 *
 * This process is accomplished by the i2400m_bootrom_init()
 * function. All the device interaction happens through the
 * i2400m_bm_cmd() [boot mode command]. Special return values will
 * indicate if the device resets.
 *
 * After this, we read the MAC address and then (if needed)
 * reinitialize the device. We need to read it ahead of time because
 * in the future, we might not upload the firmware until userspace
 * 'ifconfig up's the device.
 *
 * We can then upload the firmware file. The file is composed of a BCF
 * header (basic data, keys and signatures) and a list of write
 * commands and payloads. We first upload the header
 * [i2400m_dnload_init()] and then pass the commands and payloads
 * verbatim to the i2400m_bm_cmd() function
 * [i2400m_dnload_bcf()]. Then we tell the device to jump to the new
 * firmware [i2400m_dnload_finalize()].
 *
 * Once firmware is uploaded, we are good to go :)
 *
 * When we don't know in which mode we are, we first try by sending a
 * warm reset request that will take us to boot-mode. If we time out
 * waiting for a reboot barker, that means maybe we are already in
 * boot mode, so we send a reboot barker.
 *
 * COMMAND EXECUTION
 *
 * This code (and process) is single threaded; for executing commands,
 * we post a URB to the notification endpoint, post the command, wait
 * for data on the notification buffer. We don't need to worry about
 * others as we know we are the only ones in there.
 *
 * BACKEND IMPLEMENTATION
 *
 * This code is bus-generic; the bus-specific driver provides back end
 * implementations to send a boot mode command to the device and to
 * read an acknolwedgement from it (or an asynchronous notification)
 * from it.
 *
 * ROADMAP
 *
 * i2400m_dev_bootstrap               Called by __i2400m_dev_start()
 *   request_firmware
 *   i2400m_fw_check
 *   i2400m_fw_dnload
 *   release_firmware
 *
 * i2400m_fw_dnload
 *   i2400m_bootrom_init
 *     i2400m_bm_cmd
 *     i2400m->bus_reset
 *   i2400m_dnload_init
 *     i2400m_dnload_init_signed
 *     i2400m_dnload_init_nonsigned
 *       i2400m_download_chunk
 *         i2400m_bm_cmd
 *   i2400m_dnload_bcf
 *     i2400m_bm_cmd
 *   i2400m_dnload_finalize
 *     i2400m_bm_cmd
 *
 * i2400m_bm_cmd
 *   i2400m->bus_bm_cmd_send()
 *   i2400m->bus_bm_wait_for_ack
 *   __i2400m_bm_ack_verify
 *
 * i2400m_bm_cmd_prepare              Used by bus-drivers to prep
 *                                    commands before sending
 */
#include <linux/firmware.h>
#include <linux/sched.h>
#include <linux/usb.h>
#include "i2400m.h"


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


static const __le32 i2400m_ACK_BARKER[4] = {
	__constant_cpu_to_le32(I2400M_ACK_BARKER),
	__constant_cpu_to_le32(I2400M_ACK_BARKER),
	__constant_cpu_to_le32(I2400M_ACK_BARKER),
	__constant_cpu_to_le32(I2400M_ACK_BARKER)
};


/**
 * Prepare a boot-mode command for delivery
 *
 * @cmd: pointer to bootrom header to prepare
 *
 * Computes checksum if so needed. After calling this function, DO NOT
 * modify the command or header as the checksum won't work anymore.
 *
 * We do it from here because some times we cannot do it in the
 * original context the command was sent (it is a const), so when we
 * copy it to our staging buffer, we add the checksum there.
 */
void i2400m_bm_cmd_prepare(struct i2400m_bootrom_header *cmd)
{
	if (i2400m_brh_get_use_checksum(cmd)) {
		int i;
		u32 checksum = 0;
		const u32 *checksum_ptr = (void *) cmd->payload;
		for (i = 0; i < cmd->data_size / 4; i++)
			checksum += cpu_to_le32(*checksum_ptr++);
		checksum += cmd->command + cmd->target_addr + cmd->data_size;
		cmd->block_checksum = cpu_to_le32(checksum);
	}
}
EXPORT_SYMBOL_GPL(i2400m_bm_cmd_prepare);


/*
 * Verify the ack data received
 *
 * Given a reply to a boot mode command, chew it and verify everything
 * is ok.
 *
 * @opcode: opcode which generated this ack. For error messages.
 * @ack: pointer to ack data we received
 * @ack_size: size of that data buffer
 * @flags: I2400M_BM_CMD_* flags we called the command with.
 *
 * Way too long function -- maybe it should be further split
 */
static
ssize_t __i2400m_bm_ack_verify(struct i2400m *i2400m, int opcode,
			       struct i2400m_bootrom_header *ack,
			       size_t ack_size, int flags)
{
	ssize_t result = -ENOMEM;
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(8, dev, "(i2400m %p opcode %d ack %p size %zu)\n",
		  i2400m, opcode, ack, ack_size);
	if (ack_size < sizeof(*ack)) {
		result = -EIO;
		dev_err(dev, "boot-mode cmd %d: HW BUG? notification didn't "
			"return enough data (%zu bytes vs %zu expected)\n",
			opcode, ack_size, sizeof(*ack));
		goto error_ack_short;
	}
	if (ack_size == sizeof(i2400m_NBOOT_BARKER)
		 && memcmp(ack, i2400m_NBOOT_BARKER, sizeof(*ack)) == 0) {
		result = -ERESTARTSYS;
		i2400m->sboot = 0;
		d_printf(6, dev, "boot-mode cmd %d: "
			 "HW non-signed boot barker\n", opcode);
		goto error_reboot;
	}
	if (ack_size == sizeof(i2400m_SBOOT_BARKER)
		 && memcmp(ack, i2400m_SBOOT_BARKER, sizeof(*ack)) == 0) {
		result = -ERESTARTSYS;
		i2400m->sboot = 1;
		d_printf(6, dev, "boot-mode cmd %d: HW signed reboot barker\n",
			 opcode);
		goto error_reboot;
	}
	if (ack_size == sizeof(i2400m_ACK_BARKER)
		 && memcmp(ack, i2400m_ACK_BARKER, sizeof(*ack)) == 0) {
		result = -EISCONN;
		d_printf(3, dev, "boot-mode cmd %d: HW reboot ack barker\n",
			 opcode);
		goto error_reboot_ack;
	}
	result = 0;
	if (flags & I2400M_BM_CMD_RAW)
		goto out_raw;
	ack->data_size = le32_to_cpu(ack->data_size);
	ack->target_addr = le32_to_cpu(ack->target_addr);
	ack->block_checksum = le32_to_cpu(ack->block_checksum);
	d_printf(5, dev, "boot-mode cmd %d: notification for opcode %u "
		 "response %u csum %u rr %u da %u\n",
		 opcode, i2400m_brh_get_opcode(ack),
		 i2400m_brh_get_response(ack),
		 i2400m_brh_get_use_checksum(ack),
		 i2400m_brh_get_response_required(ack),
		 i2400m_brh_get_direct_access(ack));
	result = -EIO;
	if (i2400m_brh_get_signature(ack) != 0xcbbc) {
		dev_err(dev, "boot-mode cmd %d: HW BUG? wrong signature "
			"0x%04x\n", opcode, i2400m_brh_get_signature(ack));
		goto error_ack_signature;
	}
	if (opcode != -1 && opcode != i2400m_brh_get_opcode(ack)) {
		dev_err(dev, "boot-mode cmd %d: HW BUG? "
			"received response for opcode %u, expected %u\n",
			opcode, i2400m_brh_get_opcode(ack), opcode);
		goto error_ack_opcode;
	}
	if (i2400m_brh_get_response(ack) != 0) {	/* failed? */
		dev_err(dev, "boot-mode cmd %d: error; hw response %u\n",
			opcode, i2400m_brh_get_response(ack));
		goto error_ack_failed;
	}
	if (ack_size < ack->data_size + sizeof(*ack)) {
		dev_err(dev, "boot-mode cmd %d: SW BUG "
			"driver provided only %zu bytes for %zu bytes "
			"of data\n", opcode, ack_size,
			(size_t) le32_to_cpu(ack->data_size) + sizeof(*ack));
		goto error_ack_short_buffer;
	}
	result = ack_size;
	/* Don't you love this stack of empty targets? Well, I don't
	 * either, but it helps track exactly who comes in here and
	 * why :) */
error_ack_short_buffer:
error_ack_failed:
error_ack_opcode:
error_ack_signature:
out_raw:
error_reboot_ack:
error_reboot:
error_ack_short:
	d_fnend(8, dev, "(i2400m %p opcode %d ack %p size %zu) = %d\n",
		i2400m, opcode, ack, ack_size, (int) result);
	return result;
}


/**
 * i2400m_bm_cmd - Execute a boot mode command
 *
 * @cmd: buffer containing the command data (pointing at the header).
 *     This data can be ANYWHERE (for USB, we will copy it to an
 *     specific buffer). Make sure everything is in proper little
 *     endian.
 *
 *     A raw buffer can be also sent, just cast it and set flags to
 *     I2400M_BM_CMD_RAW.
 *
 *     This function will generate a checksum for you if the
 *     checksum bit in the command is set (unless I2400M_BM_CMD_RAW
 *     is set).
 *
 *     You can use the i2400m->bm_cmd_buf to stage your commands and
 *     send them.
 *
 *     If NULL, no command is sent (we just wait for an ack).
 *
 * @cmd_size: size of the command. Will be auto padded to the
 *     bus-specific drivers padding requirements.
 *
 * @ack: buffer where to place the acknowledgement. If it is a regular
 *     command response, all fields will be returned with the right,
 *     native endianess.
 *
 *     You *cannot* use i2400m->bm_ack_buf for this buffer.
 *
 * @ack_size: size of @ack, 16 aligned; you need to provide at least
 *     sizeof(*ack) bytes and then enough to contain the return data
 *     from the command
 *
 * @flags: see I2400M_BM_CMD_* above.
 *
 * @returns: bytes received by the notification; if < 0, an errno code
 *     denoting an error or:
 *
 *     -ERESTARTSYS  The device has rebooted
 *
 * Executes a boot-mode command and waits for a response, doing basic
 * validation on it; if a zero length response is received, it retries
 * waiting for a response until a non-zero one is received (timing out
 * after %I2400M_BOOT_RETRIES retries).
 */
static
ssize_t i2400m_bm_cmd(struct i2400m *i2400m,
		      const struct i2400m_bootrom_header *cmd, size_t cmd_size,
		      struct i2400m_bootrom_header *ack, size_t ack_size,
		      int flags)
{
	ssize_t result = -ENOMEM, rx_bytes;
	struct device *dev = i2400m_dev(i2400m);
	int opcode = cmd == NULL ? -1 : i2400m_brh_get_opcode(cmd);

	d_fnstart(6, dev, "(i2400m %p cmd %p size %zu ack %p size %zu)\n",
		  i2400m, cmd, cmd_size, ack, ack_size);
	BUG_ON(ack_size < sizeof(*ack));
	BUG_ON(i2400m->boot_mode == 0);

	if (cmd != NULL) {		/* send the command */
		memcpy(i2400m->bm_cmd_buf, cmd, cmd_size);
		result = i2400m->bus_bm_cmd_send(i2400m, cmd, cmd_size, flags);
		if (result < 0)
			goto error_cmd_send;
		if ((flags & I2400M_BM_CMD_RAW) == 0)
			d_printf(5, dev,
				 "boot-mode cmd %d csum %u rr %u da %u: "
				 "addr 0x%04x size %u block csum 0x%04x\n",
				 opcode, i2400m_brh_get_use_checksum(cmd),
				 i2400m_brh_get_response_required(cmd),
				 i2400m_brh_get_direct_access(cmd),
				 cmd->target_addr, cmd->data_size,
				 cmd->block_checksum);
	}
	result = i2400m->bus_bm_wait_for_ack(i2400m, ack, ack_size);
	if (result < 0) {
		dev_err(dev, "boot-mode cmd %d: error waiting for an ack: %d\n",
			opcode, (int) result);	/* bah, %zd doesn't work */
		goto error_wait_for_ack;
	}
	rx_bytes = result;
	/* verify the ack and read more if neccessary [result is the
	 * final amount of bytes we get in the ack]  */
	result = __i2400m_bm_ack_verify(i2400m, opcode, ack, ack_size, flags);
	if (result < 0)
		goto error_bad_ack;
	/* Don't you love this stack of empty targets? Well, I don't
	 * either, but it helps track exactly who comes in here and
	 * why :) */
	result = rx_bytes;
error_bad_ack:
error_wait_for_ack:
error_cmd_send:
	d_fnend(6, dev, "(i2400m %p cmd %p size %zu ack %p size %zu) = %d\n",
		i2400m, cmd, cmd_size, ack, ack_size, (int) result);
	return result;
}


/**
 * i2400m_download_chunk - write a single chunk of data to the device's memory
 *
 * @i2400m: device descriptor
 * @buf: the buffer to write
 * @buf_len: length of the buffer to write
 * @addr: address in the device memory space
 * @direct: bootrom write mode
 * @do_csum: should a checksum validation be performed
 */
static int i2400m_download_chunk(struct i2400m *i2400m, const void *chunk,
				 size_t __chunk_len, unsigned long addr,
				 unsigned int direct, unsigned int do_csum)
{
	int ret;
	size_t chunk_len = ALIGN(__chunk_len, I2400M_PL_PAD);
	struct device *dev = i2400m_dev(i2400m);
	struct {
		struct i2400m_bootrom_header cmd;
		u8 cmd_payload[chunk_len];
	} __attribute__((packed)) *buf;
	struct i2400m_bootrom_header ack;

	d_fnstart(5, dev, "(i2400m %p chunk %p __chunk_len %zu addr 0x%08lx "
		  "direct %u do_csum %u)\n", i2400m, chunk, __chunk_len,
		  addr, direct, do_csum);
	buf = i2400m->bm_cmd_buf;
	memcpy(buf->cmd_payload, chunk, __chunk_len);
	memset(buf->cmd_payload + __chunk_len, 0xad, chunk_len - __chunk_len);

	buf->cmd.command = i2400m_brh_command(I2400M_BRH_WRITE,
					      __chunk_len & 0x3 ? 0 : do_csum,
					      __chunk_len & 0xf ? 0 : direct);
	buf->cmd.target_addr = cpu_to_le32(addr);
	buf->cmd.data_size = cpu_to_le32(__chunk_len);
	ret = i2400m_bm_cmd(i2400m, &buf->cmd, sizeof(buf->cmd) + chunk_len,
			    &ack, sizeof(ack), 0);
	if (ret >= 0)
		ret = 0;
	d_fnend(5, dev, "(i2400m %p chunk %p __chunk_len %zu addr 0x%08lx "
		"direct %u do_csum %u) = %d\n", i2400m, chunk, __chunk_len,
		addr, direct, do_csum, ret);
	return ret;
}


/*
 * Download a BCF file's sections to the device
 *
 * @i2400m: device descriptor
 * @bcf: pointer to firmware data (followed by the payloads). Assumed
 *       verified and consistent.
 * @bcf_len: length (in bytes) of the @bcf buffer.
 *
 * Returns: < 0 errno code on error or the offset to the jump instruction.
 *
 * Given a BCF file, downloads each section (a command and a payload)
 * to the device's address space. Actually, it just executes each
 * command i the BCF file.
 *
 * The section size has to be aligned to 4 bytes AND the padding has
 * to be taken from the firmware file, as the signature takes it into
 * account.
 */
static
ssize_t i2400m_dnload_bcf(struct i2400m *i2400m,
			  const struct i2400m_bcf_hdr *bcf, size_t bcf_len)
{
	ssize_t ret;
	struct device *dev = i2400m_dev(i2400m);
	size_t offset,		/* iterator offset */
		data_size,	/* Size of the data payload */
		section_size,	/* Size of the whole section (cmd + payload) */
		section = 1;
	const struct i2400m_bootrom_header *bh;
	struct i2400m_bootrom_header ack;

	d_fnstart(3, dev, "(i2400m %p bcf %p bcf_len %zu)\n",
		  i2400m, bcf, bcf_len);
	/* Iterate over the command blocks in the BCF file that start
	 * after the header */
	offset = le32_to_cpu(bcf->header_len) * sizeof(u32);
	while (1) {	/* start sending the file */
		bh = (void *) bcf + offset;
		data_size = le32_to_cpu(bh->data_size);
		section_size = ALIGN(sizeof(*bh) + data_size, 4);
		d_printf(7, dev,
			 "downloading section #%zu (@%zu %zu B) to 0x%08x\n",
			 section, offset, sizeof(*bh) + data_size,
			 le32_to_cpu(bh->target_addr));
		if (i2400m_brh_get_opcode(bh) == I2400M_BRH_SIGNED_JUMP) {
			/* Secure boot needs to stop here */
			d_printf(5, dev,  "signed jump found @%zu\n", offset);
			break;
		}
		if (offset + section_size == bcf_len)
			/* Non-secure boot stops here */
			break;
		if (offset + section_size > bcf_len) {
			dev_err(dev, "fw %s: bad section #%zu, "
				"end (@%zu) beyond EOF (@%zu)\n",
				i2400m->bus_fw_name, section,
				offset + section_size,  bcf_len);
			ret = -EINVAL;
			goto error_section_beyond_eof;
		}
		__i2400m_msleep(20);
		ret = i2400m_bm_cmd(i2400m, bh, section_size,
				    &ack, sizeof(ack), I2400M_BM_CMD_RAW);
		if (ret < 0) {
			dev_err(dev, "fw %s: section #%zu (@%zu %zu B) "
				"failed %d\n", i2400m->bus_fw_name, section,
				offset, sizeof(*bh) + data_size, (int) ret);
			goto error_send;
		}
		offset += section_size;
		section++;
	}
	ret = offset;
error_section_beyond_eof:
error_send:
	d_fnend(3, dev, "(i2400m %p bcf %p bcf_len %zu) = %d\n",
		i2400m, bcf, bcf_len, (int) ret);
	return ret;
}


/*
 * Do the final steps of uploading firmware
 *
 * Depending on the boot mode (signed vs non-signed), different
 * actions need to be taken.
 */
static
int i2400m_dnload_finalize(struct i2400m *i2400m,
			   const struct i2400m_bcf_hdr *bcf, size_t offset)
{
	int ret = 0;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_bootrom_header *cmd, ack;
	struct {
		struct i2400m_bootrom_header cmd;
		u8 cmd_pl[0];
	} __attribute__((packed)) *cmd_buf;
	size_t signature_block_offset, signature_block_size;

	d_fnstart(3, dev, "offset %zu\n", offset);
	cmd = (void *) bcf + offset;
	if (i2400m->sboot == 0) {
		struct i2400m_bootrom_header jump_ack;
		d_printf(3, dev, "unsecure boot, jumping to 0x%08x\n",
			le32_to_cpu(cmd->target_addr));
		i2400m_brh_set_opcode(cmd, I2400M_BRH_JUMP);
		cmd->data_size = 0;
		ret = i2400m_bm_cmd(i2400m, cmd, sizeof(*cmd),
				    &jump_ack, sizeof(jump_ack), 0);
	} else {
		d_printf(3, dev, "secure boot, jumping to 0x%08x\n",
			 le32_to_cpu(cmd->target_addr));
		cmd_buf = i2400m->bm_cmd_buf;
		memcpy(&cmd_buf->cmd, cmd, sizeof(*cmd));
		signature_block_offset =
			sizeof(*bcf)
			+ le32_to_cpu(bcf->key_size) * sizeof(u32)
			+ le32_to_cpu(bcf->exponent_size) * sizeof(u32);
		signature_block_size =
			le32_to_cpu(bcf->modulus_size) * sizeof(u32);
		memcpy(cmd_buf->cmd_pl, (void *) bcf + signature_block_offset,
		       signature_block_size);
		ret = i2400m_bm_cmd(i2400m, &cmd_buf->cmd,
				    sizeof(cmd_buf->cmd) + signature_block_size,
				    &ack, sizeof(ack), I2400M_BM_CMD_RAW);
	}
	d_fnend(3, dev, "returning %d\n", ret);
	return ret;
}


/**
 * i2400m_bootrom_init - Reboots a powered device into boot mode
 *
 * @i2400m: device descriptor
 * @flags:
 *      I2400M_BRI_SOFT: a reboot notification has been seen
 *          already, so don't wait for it.
 *
 *      I2400M_BRI_NO_REBOOT: Don't send a reboot command, but wait
 *          for a reboot barker notification. This is a one shot; if
 *          the state machine needs to send a reboot command it will.
 *
 * Returns:
 *
 *     < 0 errno code on error, 0 if ok.
 *
 *     i2400m->sboot set to 0 for unsecure boot process, 1 for secure
 *     boot process.
 *
 * Description:
 *
 * Tries hard enough to put the device in boot-mode. There are two
 * main phases to this:
 *
 * a. (1) send a reboot command and (2) get a reboot barker
 * b. (1) ack the reboot sending a reboot barker and (2) getting an
 *        ack barker in return
 *
 * We want to skip (a) in some cases [soft]. The state machine is
 * horrible, but it is basically: on each phase, send what has to be
 * sent (if any), wait for the answer and act on the answer. We might
 * have to backtrack and retry, so we keep a max tries counter for
 * that.
 *
 * If we get a timeout after sending a warm reset, we do it again.
 */
int i2400m_bootrom_init(struct i2400m *i2400m, enum i2400m_bri flags)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_bootrom_header *cmd;
	struct i2400m_bootrom_header ack;
	int count = I2400M_BOOT_RETRIES;
	int ack_timeout_cnt = 1;

	BUILD_BUG_ON(sizeof(*cmd) != sizeof(i2400m_NBOOT_BARKER));
	BUILD_BUG_ON(sizeof(ack) != sizeof(i2400m_ACK_BARKER));

	d_fnstart(4, dev, "(i2400m %p flags 0x%08x)\n", i2400m, flags);
	result = -ENOMEM;
	cmd = i2400m->bm_cmd_buf;
	if (flags & I2400M_BRI_SOFT)
		goto do_reboot_ack;
do_reboot:
	if (--count < 0)
		goto error_timeout;
	d_printf(4, dev, "device reboot: reboot command [%d # left]\n",
		 count);
	if ((flags & I2400M_BRI_NO_REBOOT) == 0)
		i2400m->bus_reset(i2400m, I2400M_RT_WARM);
	result = i2400m_bm_cmd(i2400m, NULL, 0, &ack, sizeof(ack),
			       I2400M_BM_CMD_RAW);
	flags &= ~I2400M_BRI_NO_REBOOT;
	switch (result) {
	case -ERESTARTSYS:
		d_printf(4, dev, "device reboot: got reboot barker\n");
		break;
	case -EISCONN:	/* we don't know how it got here...but we follow it */
		d_printf(4, dev, "device reboot: got ack barker - whatever\n");
		goto do_reboot;
	case -ETIMEDOUT:	/* device has timed out, we might be in boot
				 * mode already and expecting an ack, let's try
				 * that */
		dev_info(dev, "warm reset timed out, trying an ack\n");
		goto do_reboot_ack;
	case -EPROTO:
	case -ESHUTDOWN:	/* dev is gone */
	case -EINTR:		/* user cancelled */
		goto error_dev_gone;
	default:
		dev_err(dev, "device reboot: error %d while waiting "
			"for reboot barker - rebooting\n", result);
		goto do_reboot;
	}
	/* At this point we ack back with 4 REBOOT barkers and expect
	 * 4 ACK barkers. This is ugly, as we send a raw command --
	 * hence the cast. _bm_cmd() will catch the reboot ack
	 * notification and report it as -EISCONN. */
do_reboot_ack:
	d_printf(4, dev, "device reboot ack: sending ack [%d # left]\n", count);
	if (i2400m->sboot == 0)
		memcpy(cmd, i2400m_NBOOT_BARKER,
		       sizeof(i2400m_NBOOT_BARKER));
	else
		memcpy(cmd, i2400m_SBOOT_BARKER,
		       sizeof(i2400m_SBOOT_BARKER));
	result = i2400m_bm_cmd(i2400m, cmd, sizeof(*cmd),
			       &ack, sizeof(ack), I2400M_BM_CMD_RAW);
	switch (result) {
	case -ERESTARTSYS:
		d_printf(4, dev, "reboot ack: got reboot barker - retrying\n");
		if (--count < 0)
			goto error_timeout;
		goto do_reboot_ack;
	case -EISCONN:
		d_printf(4, dev, "reboot ack: got ack barker - good\n");
		break;
	case -ETIMEDOUT:	/* no response, maybe it is the other type? */
		if (ack_timeout_cnt-- >= 0) {
			d_printf(4, dev, "reboot ack timedout: "
				 "trying the other type?\n");
			i2400m->sboot = !i2400m->sboot;
			goto do_reboot_ack;
		} else {
			dev_err(dev, "reboot ack timedout too long: "
				"trying reboot\n");
			goto do_reboot;
		}
		break;
	case -EPROTO:
	case -ESHUTDOWN:	/* dev is gone */
		goto error_dev_gone;
	default:
		dev_err(dev, "device reboot ack: error %d while waiting for "
			"reboot ack barker - rebooting\n", result);
		goto do_reboot;
	}
	d_printf(2, dev, "device reboot ack: got ack barker - boot done\n");
	result = 0;
exit_timeout:
error_dev_gone:
	d_fnend(4, dev, "(i2400m %p flags 0x%08x) = %d\n",
		i2400m, flags, result);
	return result;

error_timeout:
	dev_err(dev, "Timed out waiting for reboot ack, resetting\n");
	i2400m->bus_reset(i2400m, I2400M_RT_BUS);
	result = -ETIMEDOUT;
	goto exit_timeout;
}


/*
 * Read the MAC addr
 *
 * The position this function reads is fixed in device memory and
 * always available, even without firmware.
 *
 * Note we specify we want to read only six bytes, but provide space
 * for 16, as we always get it rounded up.
 */
int i2400m_read_mac_addr(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
	struct i2400m_bootrom_header *cmd;
	struct {
		struct i2400m_bootrom_header ack;
		u8 ack_pl[16];
	} __attribute__((packed)) ack_buf;

	d_fnstart(5, dev, "(i2400m %p)\n", i2400m);
	cmd = i2400m->bm_cmd_buf;
	cmd->command = i2400m_brh_command(I2400M_BRH_READ, 0, 1);
	cmd->target_addr = cpu_to_le32(0x00203fe8);
	cmd->data_size = cpu_to_le32(6);
	result = i2400m_bm_cmd(i2400m, cmd, sizeof(*cmd),
			       &ack_buf.ack, sizeof(ack_buf), 0);
	if (result < 0) {
		dev_err(dev, "BM: read mac addr failed: %d\n", result);
		goto error_read_mac;
	}
	d_printf(2, dev,
		 "mac addr is %02x:%02x:%02x:%02x:%02x:%02x\n",
		 ack_buf.ack_pl[0], ack_buf.ack_pl[1],
		 ack_buf.ack_pl[2], ack_buf.ack_pl[3],
		 ack_buf.ack_pl[4], ack_buf.ack_pl[5]);
	if (i2400m->bus_bm_mac_addr_impaired == 1) {
		ack_buf.ack_pl[0] = 0x00;
		ack_buf.ack_pl[1] = 0x16;
		ack_buf.ack_pl[2] = 0xd3;
		get_random_bytes(&ack_buf.ack_pl[3], 3);
		dev_err(dev, "BM is MAC addr impaired, faking MAC addr to "
			"mac addr is %02x:%02x:%02x:%02x:%02x:%02x\n",
			ack_buf.ack_pl[0], ack_buf.ack_pl[1],
			ack_buf.ack_pl[2], ack_buf.ack_pl[3],
			ack_buf.ack_pl[4], ack_buf.ack_pl[5]);
		result = 0;
	}
	net_dev->addr_len = ETH_ALEN;
	memcpy(net_dev->perm_addr, ack_buf.ack_pl, ETH_ALEN);
	memcpy(net_dev->dev_addr, ack_buf.ack_pl, ETH_ALEN);
error_read_mac:
	d_fnend(5, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}


/*
 * Initialize a non signed boot
 *
 * This implies sending some magic values to the device's memory. Note
 * we convert the values to little endian in the same array
 * declaration.
 */
static
int i2400m_dnload_init_nonsigned(struct i2400m *i2400m)
{
#define POKE(a, d) {					\
	.address = __constant_cpu_to_le32(a),		\
	.data = __constant_cpu_to_le32(d)		\
}
	static const struct {
		__le32 address;
		__le32 data;
	} i2400m_pokes[] = {
		POKE(0x081A58, 0xA7810230),
		POKE(0x080040, 0x00000000),
		POKE(0x080048, 0x00000082),
		POKE(0x08004C, 0x0000081F),
		POKE(0x080054, 0x00000085),
		POKE(0x080058, 0x00000180),
		POKE(0x08005C, 0x00000018),
		POKE(0x080060, 0x00000010),
		POKE(0x080574, 0x00000001),
		POKE(0x080550, 0x00000005),
		POKE(0xAE0000, 0x00000000),
	};
#undef POKE
	unsigned i;
	int ret;
	struct device *dev = i2400m_dev(i2400m);

	dev_warn(dev, "WARNING!!! non-signed boot UNTESTED PATH!\n");

	d_fnstart(5, dev, "(i2400m %p)\n", i2400m);
	for (i = 0; i < ARRAY_SIZE(i2400m_pokes); i++) {
		ret = i2400m_download_chunk(i2400m, &i2400m_pokes[i].data,
					    sizeof(i2400m_pokes[i].data),
					    i2400m_pokes[i].address, 1, 1);
		if (ret < 0)
			break;
	}
	d_fnend(5, dev, "(i2400m %p) = %d\n", i2400m, ret);
	return ret;
}


/*
 * Initialize the signed boot process
 *
 * @i2400m: device descriptor
 *
 * @bcf_hdr: pointer to the firmware header; assumes it is fully in
 *     memory (it has gone through basic validation).
 *
 * Returns: 0 if ok, < 0 errno code on error, -ERESTARTSYS if the hw
 *     rebooted.
 *
 * This writes the firmware BCF header to the device using the
 * HASH_PAYLOAD_ONLY command.
 */
static
int i2400m_dnload_init_signed(struct i2400m *i2400m,
			      const struct i2400m_bcf_hdr *bcf_hdr)
{
	int ret;
	struct device *dev = i2400m_dev(i2400m);
	struct {
		struct i2400m_bootrom_header cmd;
		struct i2400m_bcf_hdr cmd_pl;
	} __attribute__((packed)) *cmd_buf;
	struct i2400m_bootrom_header ack;

	d_fnstart(5, dev, "(i2400m %p bcf_hdr %p)\n", i2400m, bcf_hdr);
	cmd_buf = i2400m->bm_cmd_buf;
	cmd_buf->cmd.command =
		i2400m_brh_command(I2400M_BRH_HASH_PAYLOAD_ONLY, 0, 0);
	cmd_buf->cmd.target_addr = 0;
	cmd_buf->cmd.data_size = cpu_to_le32(sizeof(cmd_buf->cmd_pl));
	memcpy(&cmd_buf->cmd_pl, bcf_hdr, sizeof(*bcf_hdr));
	ret = i2400m_bm_cmd(i2400m, &cmd_buf->cmd, sizeof(*cmd_buf),
			    &ack, sizeof(ack), 0);
	if (ret >= 0)
		ret = 0;
	d_fnend(5, dev, "(i2400m %p bcf_hdr %p) = %d\n", i2400m, bcf_hdr, ret);
	return ret;
}


/*
 * Initialize the firmware download at the device size
 *
 * Multiplex to the one that matters based on the device's mode
 * (signed or non-signed).
 */
static
int i2400m_dnload_init(struct i2400m *i2400m, const struct i2400m_bcf_hdr *bcf)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	u32 module_id = le32_to_cpu(bcf->module_id);

	if (i2400m->sboot == 0
	    && (module_id & I2400M_BCF_MOD_ID_POKES) == 0) {
		/* non-signed boot process without pokes */
		result = i2400m_dnload_init_nonsigned(i2400m);
		if (result == -ERESTARTSYS)
			return result;
		if (result < 0)
			dev_err(dev, "fw %s: non-signed download "
				"initialization failed: %d\n",
				i2400m->bus_fw_name, result);
	} else if (i2400m->sboot == 0
		 && (module_id & I2400M_BCF_MOD_ID_POKES)) {
		/* non-signed boot process with pokes, nothing to do */
		result = 0;
	} else {		 /* signed boot process */
		result = i2400m_dnload_init_signed(i2400m, bcf);
		if (result == -ERESTARTSYS)
			return result;
		if (result < 0)
			dev_err(dev, "fw %s: signed boot download "
				"initialization failed: %d\n",
				i2400m->bus_fw_name, result);
	}
	return result;
}


/*
 * Run quick consistency tests on the firmware file
 *
 * Check for the firmware being made for the i2400m device,
 * etc...These checks are mostly informative, as the device will make
 * them too; but the driver's response is more informative on what
 * went wrong.
 */
static
int i2400m_fw_check(struct i2400m *i2400m,
		    const struct i2400m_bcf_hdr *bcf,
		    size_t bcf_size)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	unsigned module_type, header_len, major_version, minor_version,
		module_id, module_vendor, date, size;

	/* Check hard errors */
	result = -EINVAL;
	if (bcf_size < sizeof(*bcf)) {	/* big enough header? */
		dev_err(dev, "firmware %s too short: "
			"%zu B vs %zu (at least) expected\n",
			i2400m->bus_fw_name, bcf_size, sizeof(*bcf));
		goto error;
	}

	module_type = bcf->module_type;
	header_len = sizeof(u32) * le32_to_cpu(bcf->header_len);
	major_version = le32_to_cpu(bcf->header_version) & 0xffff0000 >> 16;
	minor_version = le32_to_cpu(bcf->header_version) & 0x0000ffff;
	module_id = le32_to_cpu(bcf->module_id);
	module_vendor = le32_to_cpu(bcf->module_vendor);
	date = le32_to_cpu(bcf->date);
	size = sizeof(u32) * le32_to_cpu(bcf->size);

	if (bcf_size != size) {		/* annoyingly paranoid */
		dev_err(dev, "firmware %s: bad size, got "
			"%zu B vs %u expected\n",
			i2400m->bus_fw_name, bcf_size, size);
		goto error;
	}

	d_printf(2, dev, "type 0x%x id 0x%x vendor 0x%x; header v%u.%u (%zu B) "
		 "date %08x (%zu B)\n",
		 module_type, module_id, module_vendor,
		 major_version, minor_version, (size_t) header_len,
		 date, (size_t) size);

	if (module_type != 6) {		/* built for the right hardware? */
		dev_err(dev, "bad fw %s: unexpected module type 0x%x; "
			"aborting\n", i2400m->bus_fw_name, module_type);
		goto error;
	}

	/* Check soft-er errors */
	result = 0;
	if (module_vendor != 0x8086)
		dev_err(dev, "bad fw %s? unexpected vendor 0x%04x\n",
			i2400m->bus_fw_name, module_vendor);
	if (date < 0x20080300)
		dev_err(dev, "bad fw %s? build date too old %08x\n",
			i2400m->bus_fw_name, date);
error:
	return result;
}


/*
 * Download the firmware to the device
 *
 * @i2400m: device descriptor
 * @bcf: pointer to loaded (and minimally verified for consistency)
 *    firmware
 * @bcf_size: size of the @bcf buffer (header plus payloads)
 *
 * The process for doing this is described in this file's header.
 *
 * Note we only reinitialize boot-mode if the flags say so. Some hw
 * iterations need it, some don't. In any case, if we loop, we always
 * need to reinitialize the boot room, hence the flags modification.
 */
static
int i2400m_fw_dnload(struct i2400m *i2400m, const struct i2400m_bcf_hdr *bcf,
		     size_t bcf_size, enum i2400m_bri flags)
{
	int ret = 0;
	struct device *dev = i2400m_dev(i2400m);
	int count = I2400M_BOOT_RETRIES;

	d_fnstart(5, dev, "(i2400m %p bcf %p size %zu)\n",
		  i2400m, bcf, bcf_size);
	i2400m->boot_mode = 1;
hw_reboot:
	if (count-- == 0) {
		ret = -ERESTARTSYS;
		dev_err(dev, "device rebooted too many times, aborting\n");
		goto error_too_many_reboots;
	}
	if (flags & I2400M_BRI_MAC_REINIT) {
		ret = i2400m_bootrom_init(i2400m, flags);
		if (ret < 0) {
			dev_err(dev, "bootrom init failed: %d\n", ret);
			goto error_bootrom_init;
		}
	}
	flags |= I2400M_BRI_MAC_REINIT;

	/*
	 * Initialize the download, push the bytes to the device and
	 * then jump to the new firmware. Note @ret is passed with the
	 * offset of the jump instruction to _dnload_finalize()
	 */
	ret = i2400m_dnload_init(i2400m, bcf);	/* Init device's dnload */
	if (ret == -ERESTARTSYS)
		goto error_dev_rebooted;
	if (ret < 0)
		goto error_dnload_init;

	ret = i2400m_dnload_bcf(i2400m, bcf, bcf_size);
	if (ret == -ERESTARTSYS)
		goto error_dev_rebooted;
	if (ret < 0) {
		dev_err(dev, "fw %s: download failed: %d\n",
			i2400m->bus_fw_name, ret);
		goto error_dnload_bcf;
	}

	ret = i2400m_dnload_finalize(i2400m, bcf, ret);
	if (ret == -ERESTARTSYS)
		goto error_dev_rebooted;
	if (ret < 0) {
		dev_err(dev, "fw %s: "
			"download finalization failed: %d\n",
			i2400m->bus_fw_name, ret);
		goto error_dnload_finalize;
	}

	d_printf(2, dev, "fw %s successfully uploaded\n",
		 i2400m->bus_fw_name);
	i2400m->boot_mode = 0;
error_dnload_finalize:
error_dnload_bcf:
error_dnload_init:
error_bootrom_init:
error_too_many_reboots:
	d_fnend(5, dev, "(i2400m %p bcf %p size %zu) = %d\n",
		i2400m, bcf, bcf_size, ret);
	return ret;

error_dev_rebooted:
	dev_err(dev, "device rebooted, %d tries left\n", count);
	/* we got the notification already, no need to wait for it again */
	flags |= I2400M_BRI_SOFT;
	goto hw_reboot;
}


/**
 * i2400m_dev_bootstrap - Bring the device to a known state and upload firmware
 *
 * @i2400m: device descriptor
 *
 * Returns: >= 0 if ok, < 0 errno code on error.
 *
 * This sets up the firmware upload environment, loads the firmware
 * file from disk, verifies and then calls the firmware upload process
 * per se.
 *
 * Can be called either from probe, or after a warm reset.  Can not be
 * called from within an interrupt.  All the flow in this code is
 * single-threade; all I/Os are synchronous.
 */
int i2400m_dev_bootstrap(struct i2400m *i2400m, enum i2400m_bri flags)
{
	int ret = 0;
	struct device *dev = i2400m_dev(i2400m);
	const struct firmware *fw;
	const struct i2400m_bcf_hdr *bcf;	/* Firmware data */

	d_fnstart(5, dev, "(i2400m %p)\n", i2400m);
	/* Load firmware files to memory. */
	ret = request_firmware(&fw, i2400m->bus_fw_name, dev);
	if (ret) {
		dev_err(dev, "fw %s: request failed: %d\n",
			i2400m->bus_fw_name, ret);
		goto error_fw_req;
	}
	bcf = (void *) fw->data;

	ret = i2400m_fw_check(i2400m, bcf, fw->size);
	if (ret < 0)
		goto error_fw_bad;
	ret = i2400m_fw_dnload(i2400m, bcf, fw->size, flags);
error_fw_bad:
	release_firmware(fw);
error_fw_req:
	d_fnend(5, dev, "(i2400m %p) = %d\n", i2400m, ret);
	return ret;
}
EXPORT_SYMBOL_GPL(i2400m_dev_bootstrap);