aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wimax/i2400m/driver.c
blob: 94dc83c3969d7498d7a625d48685741c1642a788 (plain) (blame)
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
/*
 * Intel Wireless WiMAX Connection 2400m
 * Generic probe/disconnect, reset and message passing
 *
 *
 * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@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.
 *
 *
 * See i2400m.h for driver documentation. This contains helpers for
 * the driver model glue [_setup()/_release()], handling device resets
 * [_dev_reset_handle()], and the backends for the WiMAX stack ops
 * reset [_op_reset()] and message from user [_op_msg_from_user()].
 *
 * ROADMAP:
 *
 * i2400m_op_msg_from_user()
 *   i2400m_msg_to_dev()
 *   wimax_msg_to_user_send()
 *
 * i2400m_op_reset()
 *   i240m->bus_reset()
 *
 * i2400m_dev_reset_handle()
 *   __i2400m_dev_reset_handle()
 *     __i2400m_dev_stop()
 *     __i2400m_dev_start()
 *
 * i2400m_setup()
 *   i2400m->bus_setup()
 *   i2400m_bootrom_init()
 *   register_netdev()
 *   wimax_dev_add()
 *   i2400m_dev_start()
 *     __i2400m_dev_start()
 *       i2400m_dev_bootstrap()
 *       i2400m_tx_setup()
 *       i2400m->bus_dev_start()
 *       i2400m_firmware_check()
 *       i2400m_check_mac_addr()
 *
 * i2400m_release()
 *   i2400m_dev_stop()
 *     __i2400m_dev_stop()
 *       i2400m_dev_shutdown()
 *       i2400m->bus_dev_stop()
 *       i2400m_tx_release()
 *   i2400m->bus_release()
 *   wimax_dev_rm()
 *   unregister_netdev()
 */
#include "i2400m.h"
#include <linux/etherdevice.h>
#include <linux/wimax/i2400m.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/suspend.h>
#include <linux/slab.h>

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


int i2400m_idle_mode_disabled;	/* 0 (idle mode enabled) by default */
module_param_named(idle_mode_disabled, i2400m_idle_mode_disabled, int, 0644);
MODULE_PARM_DESC(idle_mode_disabled,
		 "If true, the device will not enable idle mode negotiation "
		 "with the base station (when connected) to save power.");

int i2400m_rx_reorder_disabled;	/* 0 (rx reorder enabled) by default */
module_param_named(rx_reorder_disabled, i2400m_rx_reorder_disabled, int, 0644);
MODULE_PARM_DESC(rx_reorder_disabled,
		 "If true, RX reordering will be disabled.");

int i2400m_power_save_disabled;	/* 0 (power saving enabled) by default */
module_param_named(power_save_disabled, i2400m_power_save_disabled, int, 0644);
MODULE_PARM_DESC(power_save_disabled,
		 "If true, the driver will not tell the device to enter "
		 "power saving mode when it reports it is ready for it. "
		 "False by default (so the device is told to do power "
		 "saving).");

static char i2400m_debug_params[128];
module_param_string(debug, i2400m_debug_params, sizeof(i2400m_debug_params),
		    0644);
MODULE_PARM_DESC(debug,
		 "String of space-separated NAME:VALUE pairs, where NAMEs "
		 "are the different debug submodules and VALUE are the "
		 "initial debug value to set.");

static char i2400m_barkers_params[128];
module_param_string(barkers, i2400m_barkers_params,
		    sizeof(i2400m_barkers_params), 0644);
MODULE_PARM_DESC(barkers,
		 "String of comma-separated 32-bit values; each is "
		 "recognized as the value the device sends as a reboot "
		 "signal; values are appended to a list--setting one value "
		 "as zero cleans the existing list and starts a new one.");

static
struct i2400m_work *__i2400m_work_setup(
	struct i2400m *i2400m, void (*fn)(struct work_struct *),
	gfp_t gfp_flags, const void *pl, size_t pl_size)
{
	struct i2400m_work *iw;

	iw = kzalloc(sizeof(*iw) + pl_size, gfp_flags);
	if (iw == NULL)
		return NULL;
	iw->i2400m = i2400m_get(i2400m);
	iw->pl_size = pl_size;
	memcpy(iw->pl, pl, pl_size);
	INIT_WORK(&iw->ws, fn);
	return iw;
}


/*
 * Schedule i2400m's specific work on the system's queue.
 *
 * Used for a few cases where we really need it; otherwise, identical
 * to i2400m_queue_work().
 *
 * Returns < 0 errno code on error, 1 if ok.
 *
 * If it returns zero, something really bad happened, as it means the
 * works struct was already queued, but we have just allocated it, so
 * it should not happen.
 */
int i2400m_schedule_work(struct i2400m *i2400m,
			 void (*fn)(struct work_struct *), gfp_t gfp_flags,
			 const void *pl, size_t pl_size)
{
	int result;
	struct i2400m_work *iw;

	result = -ENOMEM;
	iw = __i2400m_work_setup(i2400m, fn, gfp_flags, pl, pl_size);
	if (iw != NULL) {
		result = schedule_work(&iw->ws);
		if (WARN_ON(result == 0))
			result = -ENXIO;
	}
	return result;
}


/*
 * WiMAX stack operation: relay a message from user space
 *
 * @wimax_dev: device descriptor
 * @pipe_name: named pipe the message is for
 * @msg_buf: pointer to the message bytes
 * @msg_len: length of the buffer
 * @genl_info: passed by the generic netlink layer
 *
 * The WiMAX stack will call this function when a message was received
 * from user space.
 *
 * For the i2400m, this is an L3L4 message, as specified in
 * include/linux/wimax/i2400m.h, and thus prefixed with a 'struct
 * i2400m_l3l4_hdr'. Driver (and device) expect the messages to be
 * coded in Little Endian.
 *
 * This function just verifies that the header declaration and the
 * payload are consistent and then deals with it, either forwarding it
 * to the device or procesing it locally.
 *
 * In the i2400m, messages are basically commands that will carry an
 * ack, so we use i2400m_msg_to_dev() and then deliver the ack back to
 * user space. The rx.c code might intercept the response and use it
 * to update the driver's state, but then it will pass it on so it can
 * be relayed back to user space.
 *
 * Note that asynchronous events from the device are processed and
 * sent to user space in rx.c.
 */
static
int i2400m_op_msg_from_user(struct wimax_dev *wimax_dev,
			    const char *pipe_name,
			    const void *msg_buf, size_t msg_len,
			    const struct genl_info *genl_info)
{
	int result;
	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;

	d_fnstart(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p "
		  "msg_len %zu genl_info %p)\n", wimax_dev, i2400m,
		  msg_buf, msg_len, genl_info);
	ack_skb = i2400m_msg_to_dev(i2400m, msg_buf, msg_len);
	result = PTR_ERR(ack_skb);
	if (IS_ERR(ack_skb))
		goto error_msg_to_dev;
	result = wimax_msg_send(&i2400m->wimax_dev, ack_skb);
error_msg_to_dev:
	d_fnend(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p msg_len %zu "
		"genl_info %p) = %d\n", wimax_dev, i2400m, msg_buf, msg_len,
		genl_info, result);
	return result;
}


/*
 * Context to wait for a reset to finalize
 */
struct i2400m_reset_ctx {
	struct completion completion;
	int result;
};


/*
 * WiMAX stack operation: reset a device
 *
 * @wimax_dev: device descriptor
 *
 * See the documentation for wimax_reset() and wimax_dev->op_reset for
 * the requirements of this function. The WiMAX stack guarantees
 * serialization on calls to this function.
 *
 * Do a warm reset on the device; if it fails, resort to a cold reset
 * and return -ENODEV. On successful warm reset, we need to block
 * until it is complete.
 *
 * The bus-driver implementation of reset takes care of falling back
 * to cold reset if warm fails.
 */
static
int i2400m_op_reset(struct wimax_dev *wimax_dev)
{
	int result;
	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_reset_ctx ctx = {
		.completion = COMPLETION_INITIALIZER_ONSTACK(ctx.completion),
		.result = 0,
	};

	d_fnstart(4, dev, "(wimax_dev %p)\n", wimax_dev);
	mutex_lock(&i2400m->init_mutex);
	i2400m->reset_ctx = &ctx;
	mutex_unlock(&i2400m->init_mutex);
	result = i2400m_reset(i2400m, I2400M_RT_WARM);
	if (result < 0)
		goto out;
	result = wait_for_completion_timeout(&ctx.completion, 4*HZ);
	if (result == 0)
		result = -ETIMEDOUT;
	else if (result > 0)
		result = ctx.result;
	/* if result < 0, pass it on */
	mutex_lock(&i2400m->init_mutex);
	i2400m->reset_ctx = NULL;
	mutex_unlock(&i2400m->init_mutex);
out:
	d_fnend(4, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
	return result;
}


/*
 * Check the MAC address we got from boot mode is ok
 *
 * @i2400m: device descriptor
 *
 * Returns: 0 if ok, < 0 errno code on error.
 */
static
int i2400m_check_mac_addr(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *skb;
	const struct i2400m_tlv_detailed_device_info *ddi;
	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
	const unsigned char zeromac[ETH_ALEN] = { 0 };

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	skb = i2400m_get_device_info(i2400m);
	if (IS_ERR(skb)) {
		result = PTR_ERR(skb);
		dev_err(dev, "Cannot verify MAC address, error reading: %d\n",
			result);
		goto error;
	}
	/* Extract MAC addresss */
	ddi = (void *) skb->data;
	BUILD_BUG_ON(ETH_ALEN != sizeof(ddi->mac_address));
	d_printf(2, dev, "GET DEVICE INFO: mac addr %pM\n",
		 ddi->mac_address);
	if (!memcmp(net_dev->perm_addr, ddi->mac_address,
		   sizeof(ddi->mac_address)))
		goto ok;
	dev_warn(dev, "warning: device reports a different MAC address "
		 "to that of boot mode's\n");
	dev_warn(dev, "device reports     %pM\n", ddi->mac_address);
	dev_warn(dev, "boot mode reported %pM\n", net_dev->perm_addr);
	if (!memcmp(zeromac, ddi->mac_address, sizeof(zeromac)))
		dev_err(dev, "device reports an invalid MAC address, "
			"not updating\n");
	else {
		dev_warn(dev, "updating MAC address\n");
		net_dev->addr_len = ETH_ALEN;
		memcpy(net_dev->perm_addr, ddi->mac_address, ETH_ALEN);
		memcpy(net_dev->dev_addr, ddi->mac_address, ETH_ALEN);
	}
ok:
	result = 0;
	kfree_skb(skb);
error:
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}


/**
 * __i2400m_dev_start - Bring up driver communication with the device
 *
 * @i2400m: device descriptor
 * @flags: boot mode flags
 *
 * Returns: 0 if ok, < 0 errno code on error.
 *
 * Uploads firmware and brings up all the resources needed to be able
 * to communicate with the device.
 *
 * The workqueue has to be setup early, at least before RX handling
 * (it's only real user for now) so it can process reports as they
 * arrive. We also want to destroy it if we retry, to make sure it is
 * flushed...easier like this.
 *
 * TX needs to be setup before the bus-specific code (otherwise on
 * shutdown, the bus-tx code could try to access it).
 */
static
int __i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri flags)
{
	int result;
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	struct net_device *net_dev = wimax_dev->net_dev;
	struct device *dev = i2400m_dev(i2400m);
	int times = i2400m->bus_bm_retries;

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
retry:
	result = i2400m_dev_bootstrap(i2400m, flags);
	if (result < 0) {
		dev_err(dev, "cannot bootstrap device: %d\n", result);
		goto error_bootstrap;
	}
	result = i2400m_tx_setup(i2400m);
	if (result < 0)
		goto error_tx_setup;
	result = i2400m_rx_setup(i2400m);
	if (result < 0)
		goto error_rx_setup;
	i2400m->work_queue = create_singlethread_workqueue(wimax_dev->name);
	if (i2400m->work_queue == NULL) {
		result = -ENOMEM;
		dev_err(dev, "cannot create workqueue\n");
		goto error_create_workqueue;
	}
	if (i2400m->bus_dev_start) {
		result = i2400m->bus_dev_start(i2400m);
		if (result < 0)
			goto error_bus_dev_start;
	}
	i2400m->ready = 1;
	wmb();		/* see i2400m->ready's documentation  */
	/* process pending reports from the device */
	queue_work(i2400m->work_queue, &i2400m->rx_report_ws);
	result = i2400m_firmware_check(i2400m);	/* fw versions ok? */
	if (result < 0)
		goto error_fw_check;
	/* At this point is ok to send commands to the device */
	result = i2400m_check_mac_addr(i2400m);
	if (result < 0)
		goto error_check_mac_addr;
	result = i2400m_dev_initialize(i2400m);
	if (result < 0)
		goto error_dev_initialize;
	/* At this point, reports will come for the device and set it
	 * to the right state if it is different than UNINITIALIZED */
	d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
		net_dev, i2400m, result);
	return result;

error_dev_initialize:
error_check_mac_addr:
	i2400m->ready = 0;
	wmb();		/* see i2400m->ready's documentation  */
	flush_workqueue(i2400m->work_queue);
error_fw_check:
	if (i2400m->bus_dev_stop)
		i2400m->bus_dev_stop(i2400m);
error_bus_dev_start:
	destroy_workqueue(i2400m->work_queue);
error_create_workqueue:
	i2400m_rx_release(i2400m);
error_rx_setup:
	i2400m_tx_release(i2400m);
error_tx_setup:
error_bootstrap:
	if (result == -EL3RST && times-- > 0) {
		flags = I2400M_BRI_SOFT|I2400M_BRI_MAC_REINIT;
		goto retry;
	}
	d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
		net_dev, i2400m, result);
	return result;
}


static
int i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri bm_flags)
{
	int result = 0;
	mutex_lock(&i2400m->init_mutex);	/* Well, start the device */
	if (i2400m->updown == 0) {
		result = __i2400m_dev_start(i2400m, bm_flags);
		if (result >= 0) {
			i2400m->updown = 1;
			wmb();	/* see i2400m->updown's documentation */
		}
	}
	mutex_unlock(&i2400m->init_mutex);
	return result;
}


/**
 * i2400m_dev_stop - Tear down driver communication with the device
 *
 * @i2400m: device descriptor
 *
 * Returns: 0 if ok, < 0 errno code on error.
 *
 * Releases all the resources allocated to communicate with the
 * device. Note we cannot destroy the workqueue earlier as until RX is
 * fully destroyed, it could still try to schedule jobs.
 */
static
void __i2400m_dev_stop(struct i2400m *i2400m)
{
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
	i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
	complete(&i2400m->msg_completion);
	i2400m_net_wake_stop(i2400m);
	i2400m_dev_shutdown(i2400m);
	/*
	 * Make sure no report hooks are running *before* we stop the
	 * communication infrastructure with the device.
	 */
	i2400m->ready = 0;	/* nobody can queue work anymore */
	wmb();		/* see i2400m->ready's documentation  */
	flush_workqueue(i2400m->work_queue);

	if (i2400m->bus_dev_stop)
		i2400m->bus_dev_stop(i2400m);
	destroy_workqueue(i2400m->work_queue);
	i2400m_rx_release(i2400m);
	i2400m_tx_release(i2400m);
	wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
	d_fnend(3, dev, "(i2400m %p) = 0\n", i2400m);
}


/*
 * Watch out -- we only need to stop if there is a need for it. The
 * device could have reset itself and failed to come up again (see
 * _i2400m_dev_reset_handle()).
 */
static
void i2400m_dev_stop(struct i2400m *i2400m)
{
	mutex_lock(&i2400m->init_mutex);
	if (i2400m->updown) {
		__i2400m_dev_stop(i2400m);
		i2400m->updown = 0;
		wmb();	/* see i2400m->updown's documentation  */
	}
	mutex_unlock(&i2400m->init_mutex);
}


/*
 * Listen to PM events to cache the firmware before suspend/hibernation
 *
 * When the device comes out of suspend, it might go into reset and
 * firmware has to be uploaded again. At resume, most of the times, we
 * can't load firmware images from disk, so we need to cache it.
 *
 * i2400m_fw_cache() will allocate a kobject and attach the firmware
 * to it; that way we don't have to worry too much about the fw loader
 * hitting a race condition.
 *
 * Note: modus operandi stolen from the Orinoco driver; thx.
 */
static
int i2400m_pm_notifier(struct notifier_block *notifier,
		       unsigned long pm_event,
		       void *unused)
{
	struct i2400m *i2400m =
		container_of(notifier, struct i2400m, pm_notifier);
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p pm_event %lx)\n", i2400m, pm_event);
	switch (pm_event) {
	case PM_HIBERNATION_PREPARE:
	case PM_SUSPEND_PREPARE:
		i2400m_fw_cache(i2400m);
		break;
	case PM_POST_RESTORE:
		/* Restore from hibernation failed. We need to clean
		 * up in exactly the same way, so fall through. */
	case PM_POST_HIBERNATION:
	case PM_POST_SUSPEND:
		i2400m_fw_uncache(i2400m);
		break;

	case PM_RESTORE_PREPARE:
	default:
		break;
	}
	d_fnend(3, dev, "(i2400m %p pm_event %lx) = void\n", i2400m, pm_event);
	return NOTIFY_DONE;
}


/*
 * pre-reset is called before a device is going on reset
 *
 * This has to be followed by a call to i2400m_post_reset(), otherwise
 * bad things might happen.
 */
int i2400m_pre_reset(struct i2400m *i2400m)
{
	int result;
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	d_printf(1, dev, "pre-reset shut down\n");

	result = 0;
	mutex_lock(&i2400m->init_mutex);
	if (i2400m->updown) {
		netif_tx_disable(i2400m->wimax_dev.net_dev);
		__i2400m_dev_stop(i2400m);
		result = 0;
		/* down't set updown to zero -- this way
		 * post_reset can restore properly */
	}
	mutex_unlock(&i2400m->init_mutex);
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_pre_reset);


/*
 * Restore device state after a reset
 *
 * Do the work needed after a device reset to bring it up to the same
 * state as it was before the reset.
 *
 * NOTE: this requires i2400m->init_mutex taken
 */
int i2400m_post_reset(struct i2400m *i2400m)
{
	int result = 0;
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	d_printf(1, dev, "post-reset start\n");
	if (i2400m->bus_setup) {
		result = i2400m->bus_setup(i2400m);
		if (result < 0) {
			dev_err(dev, "bus-specific setup failed: %d\n",
				result);
			goto error_bus_setup;
		}
	}
	mutex_lock(&i2400m->init_mutex);
	if (i2400m->updown) {
		result = __i2400m_dev_start(
			i2400m, I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
		if (result < 0)
			goto error_dev_start;
	}
	mutex_unlock(&i2400m->init_mutex);
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;

error_dev_start:
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
error_bus_setup:
	/* even if the device was up, it could not be recovered, so we
	 * mark it as down. */
	i2400m->updown = 0;
	wmb();		/* see i2400m->updown's documentation  */
	mutex_unlock(&i2400m->init_mutex);
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_post_reset);


/*
 * The device has rebooted; fix up the device and the driver
 *
 * Tear down the driver communication with the device, reload the
 * firmware and reinitialize the communication with the device.
 *
 * If someone calls a reset when the device's firmware is down, in
 * theory we won't see it because we are not listening. However, just
 * in case, leave the code to handle it.
 *
 * If there is a reset context, use it; this means someone is waiting
 * for us to tell him when the reset operation is complete and the
 * device is ready to rock again.
 *
 * NOTE: if we are in the process of bringing up or down the
 *       communication with the device [running i2400m_dev_start() or
 *       _stop()], don't do anything, let it fail and handle it.
 *
 * This function is ran always in a thread context
 *
 * This function gets passed, as payload to i2400m_work() a 'const
 * char *' ptr with a "reason" why the reset happened (for messages).
 */
static
void __i2400m_dev_reset_handle(struct work_struct *ws)
{
	int result;
	struct i2400m_work *iw = container_of(ws, struct i2400m_work, ws);
	const char *reason;
	struct i2400m *i2400m = iw->i2400m;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_reset_ctx *ctx = i2400m->reset_ctx;

	if (WARN_ON(iw->pl_size != sizeof(reason)))
		reason = "SW BUG: reason n/a";
	else
		memcpy(&reason, iw->pl, sizeof(reason));

	d_fnstart(3, dev, "(ws %p i2400m %p reason %s)\n", ws, i2400m, reason);

	result = 0;
	if (mutex_trylock(&i2400m->init_mutex) == 0) {
		/* We are still in i2400m_dev_start() [let it fail] or
		 * i2400m_dev_stop() [we are shutting down anyway, so
		 * ignore it] or we are resetting somewhere else. */
		dev_err(dev, "device rebooted somewhere else?\n");
		i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
		complete(&i2400m->msg_completion);
		goto out;
	}
	if (i2400m->updown == 0)  {
		dev_info(dev, "%s: device is down, doing nothing\n", reason);
		goto out_unlock;
	}
	dev_err(dev, "%s: reinitializing driver\n", reason);
	__i2400m_dev_stop(i2400m);
	result = __i2400m_dev_start(i2400m,
				    I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
	if (result < 0) {
		i2400m->updown = 0;
		wmb();		/* see i2400m->updown's documentation  */
		dev_err(dev, "%s: cannot start the device: %d\n",
			reason, result);
		result = -EUCLEAN;
	}
out_unlock:
	if (i2400m->reset_ctx) {
		ctx->result = result;
		complete(&ctx->completion);
	}
	mutex_unlock(&i2400m->init_mutex);
	if (result == -EUCLEAN) {
		/* ops, need to clean up [w/ init_mutex not held] */
		result = i2400m_reset(i2400m, I2400M_RT_BUS);
		if (result >= 0)
			result = -ENODEV;
	}
out:
	i2400m_put(i2400m);
	kfree(iw);
	d_fnend(3, dev, "(ws %p i2400m %p reason %s) = void\n",
		ws, i2400m, reason);
	return;
}


/**
 * i2400m_dev_reset_handle - Handle a device's reset in a thread context
 *
 * Schedule a device reset handling out on a thread context, so it
 * is safe to call from atomic context. We can't use the i2400m's
 * queue as we are going to destroy it and reinitialize it as part of
 * the driver bringup/bringup process.
 *
 * See __i2400m_dev_reset_handle() for details; that takes care of
 * reinitializing the driver to handle the reset, calling into the
 * bus-specific functions ops as needed.
 */
int i2400m_dev_reset_handle(struct i2400m *i2400m, const char *reason)
{
	i2400m->boot_mode = 1;
	wmb();		/* Make sure i2400m_msg_to_dev() sees boot_mode */
	return i2400m_schedule_work(i2400m, __i2400m_dev_reset_handle,
				    GFP_ATOMIC, &reason, sizeof(reason));
}
EXPORT_SYMBOL_GPL(i2400m_dev_reset_handle);


/*
 * Alloc the command and ack buffers for boot mode
 *
 * Get the buffers needed to deal with boot mode messages.  These
 * buffers need to be allocated before the sdio recieve irq is setup.
 */
static
int i2400m_bm_buf_alloc(struct i2400m *i2400m)
{
	int result;

	result = -ENOMEM;
	i2400m->bm_cmd_buf = kzalloc(I2400M_BM_CMD_BUF_SIZE, GFP_KERNEL);
	if (i2400m->bm_cmd_buf == NULL)
		goto error_bm_cmd_kzalloc;
	i2400m->bm_ack_buf = kzalloc(I2400M_BM_ACK_BUF_SIZE, GFP_KERNEL);
	if (i2400m->bm_ack_buf == NULL)
		goto error_bm_ack_buf_kzalloc;
	return 0;

error_bm_ack_buf_kzalloc:
	kfree(i2400m->bm_cmd_buf);
error_bm_cmd_kzalloc:
	return result;
}


/*
 * Free boot mode command and ack buffers.
 */
static
void i2400m_bm_buf_free(struct i2400m *i2400m)
{
	kfree(i2400m->bm_ack_buf);
	kfree(i2400m->bm_cmd_buf);
}


/**
 * i2400m_init - Initialize a 'struct i2400m' from all zeroes
 *
 * This is a bus-generic API call.
 */
void i2400m_init(struct i2400m *i2400m)
{
	wimax_dev_init(&i2400m->wimax_dev);

	i2400m->boot_mode = 1;
	i2400m->rx_reorder = 1;
	init_waitqueue_head(&i2400m->state_wq);

	spin_lock_init(&i2400m->tx_lock);
	i2400m->tx_pl_min = UINT_MAX;
	i2400m->tx_size_min = UINT_MAX;

	spin_lock_init(&i2400m->rx_lock);
	i2400m->rx_pl_min = UINT_MAX;
	i2400m->rx_size_min = UINT_MAX;
	INIT_LIST_HEAD(&i2400m->rx_reports);
	INIT_WORK(&i2400m->rx_report_ws, i2400m_report_hook_work);

	mutex_init(&i2400m->msg_mutex);
	init_completion(&i2400m->msg_completion);

	mutex_init(&i2400m->init_mutex);
	/* wake_tx_ws is initialized in i2400m_tx_setup() */
}
EXPORT_SYMBOL_GPL(i2400m_init);


int i2400m_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
{
	struct net_device *net_dev = i2400m->wimax_dev.net_dev;

	/*
	 * Make sure we stop TXs and down the carrier before
	 * resetting; this is needed to avoid things like
	 * i2400m_wake_tx() scheduling stuff in parallel.
	 */
	if (net_dev->reg_state == NETREG_REGISTERED) {
		netif_tx_disable(net_dev);
		netif_carrier_off(net_dev);
	}
	return i2400m->bus_reset(i2400m, rt);
}
EXPORT_SYMBOL_GPL(i2400m_reset);


/**
 * i2400m_setup - bus-generic setup function for the i2400m device
 *
 * @i2400m: device descriptor (bus-specific parts have been initialized)
 *
 * Returns: 0 if ok, < 0 errno code on error.
 *
 * Sets up basic device comunication infrastructure, boots the ROM to
 * read the MAC address, registers with the WiMAX and network stacks
 * and then brings up the device.
 */
int i2400m_setup(struct i2400m *i2400m, enum i2400m_bri bm_flags)
{
	int result = -ENODEV;
	struct device *dev = i2400m_dev(i2400m);
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	struct net_device *net_dev = i2400m->wimax_dev.net_dev;

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);

	snprintf(wimax_dev->name, sizeof(wimax_dev->name),
		 "i2400m-%s:%s", dev->bus->name, dev_name(dev));

	result = i2400m_bm_buf_alloc(i2400m);
	if (result < 0) {
		dev_err(dev, "cannot allocate bootmode scratch buffers\n");
		goto error_bm_buf_alloc;
	}

	if (i2400m->bus_setup) {
		result = i2400m->bus_setup(i2400m);
		if (result < 0) {
			dev_err(dev, "bus-specific setup failed: %d\n",
				result);
			goto error_bus_setup;
		}
	}

	result = i2400m_bootrom_init(i2400m, bm_flags);
	if (result < 0) {
		dev_err(dev, "read mac addr: bootrom init "
			"failed: %d\n", result);
		goto error_bootrom_init;
	}
	result = i2400m_read_mac_addr(i2400m);
	if (result < 0)
		goto error_read_mac_addr;
	random_ether_addr(i2400m->src_mac_addr);

	i2400m->pm_notifier.notifier_call = i2400m_pm_notifier;
	register_pm_notifier(&i2400m->pm_notifier);

	result = register_netdev(net_dev);	/* Okey dokey, bring it up */
	if (result < 0) {
		dev_err(dev, "cannot register i2400m network device: %d\n",
			result);
		goto error_register_netdev;
	}
	netif_carrier_off(net_dev);

	i2400m->wimax_dev.op_msg_from_user = i2400m_op_msg_from_user;
	i2400m->wimax_dev.op_rfkill_sw_toggle = i2400m_op_rfkill_sw_toggle;
	i2400m->wimax_dev.op_reset = i2400m_op_reset;

	result = wimax_dev_add(&i2400m->wimax_dev, net_dev);
	if (result < 0)
		goto error_wimax_dev_add;

	/* Now setup all that requires a registered net and wimax device. */
	result = sysfs_create_group(&net_dev->dev.kobj, &i2400m_dev_attr_group);
	if (result < 0) {
		dev_err(dev, "cannot setup i2400m's sysfs: %d\n", result);
		goto error_sysfs_setup;
	}

	result = i2400m_debugfs_add(i2400m);
	if (result < 0) {
		dev_err(dev, "cannot setup i2400m's debugfs: %d\n", result);
		goto error_debugfs_setup;
	}

	result = i2400m_dev_start(i2400m, bm_flags);
	if (result < 0)
		goto error_dev_start;
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;

error_dev_start:
	i2400m_debugfs_rm(i2400m);
error_debugfs_setup:
	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
			   &i2400m_dev_attr_group);
error_sysfs_setup:
	wimax_dev_rm(&i2400m->wimax_dev);
error_wimax_dev_add:
	unregister_netdev(net_dev);
error_register_netdev:
	unregister_pm_notifier(&i2400m->pm_notifier);
error_read_mac_addr:
error_bootrom_init:
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
error_bus_setup:
	i2400m_bm_buf_free(i2400m);
error_bm_buf_alloc:
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_setup);


/**
 * i2400m_release - release the bus-generic driver resources
 *
 * Sends a disconnect message and undoes any setup done by i2400m_setup()
 */
void i2400m_release(struct i2400m *i2400m)
{
	struct device *dev = i2400m_dev(i2400m);

	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
	netif_stop_queue(i2400m->wimax_dev.net_dev);

	i2400m_dev_stop(i2400m);

	i2400m_debugfs_rm(i2400m);
	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
			   &i2400m_dev_attr_group);
	wimax_dev_rm(&i2400m->wimax_dev);
	unregister_netdev(i2400m->wimax_dev.net_dev);
	unregister_pm_notifier(&i2400m->pm_notifier);
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
	i2400m_bm_buf_free(i2400m);
	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
}
EXPORT_SYMBOL_GPL(i2400m_release);


/*
 * Debug levels control; see debug.h
 */
struct d_level D_LEVEL[] = {
	D_SUBMODULE_DEFINE(control),
	D_SUBMODULE_DEFINE(driver),
	D_SUBMODULE_DEFINE(debugfs),
	D_SUBMODULE_DEFINE(fw),
	D_SUBMODULE_DEFINE(netdev),
	D_SUBMODULE_DEFINE(rfkill),
	D_SUBMODULE_DEFINE(rx),
	D_SUBMODULE_DEFINE(sysfs),
	D_SUBMODULE_DEFINE(tx),
};
size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);


static
int __init i2400m_driver_init(void)
{
	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400m_debug_params,
		       "i2400m.debug");
	return i2400m_barker_db_init(i2400m_barkers_params);
}
module_init(i2400m_driver_init);

static
void __exit i2400m_driver_exit(void)
{
	/* for scheds i2400m_dev_reset_handle() */
	flush_scheduled_work();
	i2400m_barker_db_exit();
	return;
}
module_exit(i2400m_driver_exit);

MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
MODULE_DESCRIPTION("Intel 2400M WiMAX networking bus-generic driver");
MODULE_LICENSE("GPL");