aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hsi/clients/ssi_protocol.c
blob: 7ef819680acda13077f773c5fe65f12f7349cbb4 (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
/*
 * ssi_protocol.c
 *
 * Implementation of the SSI McSAAB improved protocol.
 *
 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
 * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org>
 *
 * Contact: Carlos Chinea <carlos.chinea@nokia.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 St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/if_phonet.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/notifier.h>
#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/hsi/hsi.h>
#include <linux/hsi/ssi_protocol.h>

void ssi_waketest(struct hsi_client *cl, unsigned int enable);

#define SSIP_TXQUEUE_LEN	100
#define SSIP_MAX_MTU		65535
#define SSIP_DEFAULT_MTU	4000
#define PN_MEDIA_SOS		21
#define SSIP_MIN_PN_HDR		6	/* FIXME: Revisit */
#define SSIP_WDTOUT		2000	/* FIXME: has to be 500 msecs */
#define SSIP_KATOUT		15	/* 15 msecs */
#define SSIP_MAX_CMDS		5 /* Number of pre-allocated commands buffers */
#define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
#define SSIP_CMT_LOADER_SYNC	0x11223344
/*
 * SSI protocol command definitions
 */
#define SSIP_COMMAND(data)	((data) >> 28)
#define SSIP_PAYLOAD(data)	((data) & 0xfffffff)
/* Commands */
#define SSIP_SW_BREAK		0
#define SSIP_BOOTINFO_REQ	1
#define SSIP_BOOTINFO_RESP	2
#define SSIP_WAKETEST_RESULT	3
#define SSIP_START_TRANS	4
#define SSIP_READY		5
/* Payloads */
#define SSIP_DATA_VERSION(data)	((data) & 0xff)
#define SSIP_LOCAL_VERID	1
#define SSIP_WAKETEST_OK	0
#define SSIP_WAKETEST_FAILED	1
#define SSIP_PDU_LENGTH(data)	(((data) >> 8) & 0xffff)
#define SSIP_MSG_ID(data)	((data) & 0xff)
/* Generic Command */
#define SSIP_CMD(cmd, payload)	(((cmd) << 28) | ((payload) & 0xfffffff))
/* Commands for the control channel */
#define SSIP_BOOTINFO_REQ_CMD(ver) \
		SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
#define SSIP_BOOTINFO_RESP_CMD(ver) \
		SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
#define SSIP_START_TRANS_CMD(pdulen, id) \
		SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
#define SSIP_READY_CMD		SSIP_CMD(SSIP_READY, 0)
#define SSIP_SWBREAK_CMD	SSIP_CMD(SSIP_SW_BREAK, 0)

#define SSIP_WAKETEST_FLAG 0

/* Main state machine states */
enum {
	INIT,
	HANDSHAKE,
	ACTIVE,
};

/* Send state machine states */
enum {
	SEND_IDLE,
	WAIT4READY,
	SEND_READY,
	SENDING,
	SENDING_SWBREAK,
};

/* Receive state machine states */
enum {
	RECV_IDLE,
	RECV_READY,
	RECEIVING,
};

/**
 * struct ssi_protocol - SSI protocol (McSAAB) data
 * @main_state: Main state machine
 * @send_state: TX state machine
 * @recv_state: RX state machine
 * @flags: Flags, currently only used to follow wake line test
 * @rxid: RX data id
 * @txid: TX data id
 * @txqueue_len: TX queue length
 * @tx_wd: TX watchdog
 * @rx_wd: RX watchdog
 * @keep_alive: Workaround for SSI HW bug
 * @lock: To serialize access to this struct
 * @netdev: Phonet network device
 * @txqueue: TX data queue
 * @cmdqueue: Queue of free commands
 * @cl: HSI client own reference
 * @link: Link for ssip_list
 * @tx_usecount: Refcount to keep track the slaves that use the wake line
 * @channel_id_cmd: HSI channel id for command stream
 * @channel_id_data: HSI channel id for data stream
 */
struct ssi_protocol {
	unsigned int		main_state;
	unsigned int		send_state;
	unsigned int		recv_state;
	unsigned long		flags;
	u8			rxid;
	u8			txid;
	unsigned int		txqueue_len;
	struct timer_list	tx_wd;
	struct timer_list	rx_wd;
	struct timer_list	keep_alive; /* wake-up workaround */
	spinlock_t		lock;
	struct net_device	*netdev;
	struct list_head	txqueue;
	struct list_head	cmdqueue;
	struct work_struct	work;
	struct hsi_client	*cl;
	struct list_head	link;
	atomic_t		tx_usecnt;
	int			channel_id_cmd;
	int			channel_id_data;
};

/* List of ssi protocol instances */
static LIST_HEAD(ssip_list);

static void ssip_rxcmd_complete(struct hsi_msg *msg);

static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
{
	u32 *data;

	data = sg_virt(msg->sgt.sgl);
	*data = cmd;
}

static inline u32 ssip_get_cmd(struct hsi_msg *msg)
{
	u32 *data;

	data = sg_virt(msg->sgt.sgl);

	return *data;
}

static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
{
	skb_frag_t *frag;
	struct scatterlist *sg;
	int i;

	BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));

	sg = msg->sgt.sgl;
	sg_set_buf(sg, skb->data, skb_headlen(skb));
	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
		sg = sg_next(sg);
		BUG_ON(!sg);
		frag = &skb_shinfo(skb)->frags[i];
		sg_set_page(sg, frag->page.p, frag->size, frag->page_offset);
	}
}

static void ssip_free_data(struct hsi_msg *msg)
{
	struct sk_buff *skb;

	skb = msg->context;
	pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
								skb);
	msg->destructor = NULL;
	dev_kfree_skb(skb);
	hsi_free_msg(msg);
}

static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
					struct sk_buff *skb, gfp_t flags)
{
	struct hsi_msg *msg;

	msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
	if (!msg)
		return NULL;
	ssip_skb_to_msg(skb, msg);
	msg->destructor = ssip_free_data;
	msg->channel = ssi->channel_id_data;
	msg->context = skb;

	return msg;
}

static inline void ssip_release_cmd(struct hsi_msg *msg)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);

	dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
	spin_lock_bh(&ssi->lock);
	list_add_tail(&msg->link, &ssi->cmdqueue);
	spin_unlock_bh(&ssi->lock);
}

static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
{
	struct hsi_msg *msg;

	BUG_ON(list_empty(&ssi->cmdqueue));

	spin_lock_bh(&ssi->lock);
	msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
	list_del(&msg->link);
	spin_unlock_bh(&ssi->lock);
	msg->destructor = ssip_release_cmd;

	return msg;
}

static void ssip_free_cmds(struct ssi_protocol *ssi)
{
	struct hsi_msg *msg, *tmp;

	list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
		list_del(&msg->link);
		msg->destructor = NULL;
		kfree(sg_virt(msg->sgt.sgl));
		hsi_free_msg(msg);
	}
}

static int ssip_alloc_cmds(struct ssi_protocol *ssi)
{
	struct hsi_msg *msg;
	u32 *buf;
	unsigned int i;

	for (i = 0; i < SSIP_MAX_CMDS; i++) {
		msg = hsi_alloc_msg(1, GFP_KERNEL);
		if (!msg)
			goto out;
		buf = kmalloc(sizeof(*buf), GFP_KERNEL);
		if (!buf) {
			hsi_free_msg(msg);
			goto out;
		}
		sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
		msg->channel = ssi->channel_id_cmd;
		list_add_tail(&msg->link, &ssi->cmdqueue);
	}

	return 0;
out:
	ssip_free_cmds(ssi);

	return -ENOMEM;
}

static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
{
	ssi->recv_state = state;
	switch (state) {
	case RECV_IDLE:
		del_timer(&ssi->rx_wd);
		if (ssi->send_state == SEND_IDLE)
			del_timer(&ssi->keep_alive);
		break;
	case RECV_READY:
		/* CMT speech workaround */
		if (atomic_read(&ssi->tx_usecnt))
			break;
		/* Otherwise fall through */
	case RECEIVING:
		mod_timer(&ssi->keep_alive, jiffies +
						msecs_to_jiffies(SSIP_KATOUT));
		mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
		break;
	default:
		break;
	}
}

static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
{
	ssi->send_state = state;
	switch (state) {
	case SEND_IDLE:
	case SEND_READY:
		del_timer(&ssi->tx_wd);
		if (ssi->recv_state == RECV_IDLE)
			del_timer(&ssi->keep_alive);
		break;
	case WAIT4READY:
	case SENDING:
	case SENDING_SWBREAK:
		mod_timer(&ssi->keep_alive,
				jiffies + msecs_to_jiffies(SSIP_KATOUT));
		mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
		break;
	default:
		break;
	}
}

struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
{
	struct hsi_client *master = ERR_PTR(-ENODEV);
	struct ssi_protocol *ssi;

	list_for_each_entry(ssi, &ssip_list, link)
		if (slave->device.parent == ssi->cl->device.parent) {
			master = ssi->cl;
			break;
		}

	return master;
}
EXPORT_SYMBOL_GPL(ssip_slave_get_master);

int ssip_slave_start_tx(struct hsi_client *master)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(master);

	dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
	spin_lock_bh(&ssi->lock);
	if (ssi->send_state == SEND_IDLE) {
		ssip_set_txstate(ssi, WAIT4READY);
		hsi_start_tx(master);
	}
	spin_unlock_bh(&ssi->lock);
	atomic_inc(&ssi->tx_usecnt);

	return 0;
}
EXPORT_SYMBOL_GPL(ssip_slave_start_tx);

int ssip_slave_stop_tx(struct hsi_client *master)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(master);

	WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);

	if (atomic_dec_and_test(&ssi->tx_usecnt)) {
		spin_lock_bh(&ssi->lock);
		if ((ssi->send_state == SEND_READY) ||
			(ssi->send_state == WAIT4READY)) {
			ssip_set_txstate(ssi, SEND_IDLE);
			hsi_stop_tx(master);
		}
		spin_unlock_bh(&ssi->lock);
	}
	dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));

	return 0;
}
EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);

int ssip_slave_running(struct hsi_client *master)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(master);
	return netif_running(ssi->netdev);
}
EXPORT_SYMBOL_GPL(ssip_slave_running);

static void ssip_reset(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct list_head *head, *tmp;
	struct hsi_msg *msg;

	if (netif_running(ssi->netdev))
		netif_carrier_off(ssi->netdev);
	hsi_flush(cl);
	spin_lock_bh(&ssi->lock);
	if (ssi->send_state != SEND_IDLE)
		hsi_stop_tx(cl);
	spin_unlock_bh(&ssi->lock);
	if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
		ssi_waketest(cl, 0); /* FIXME: To be removed */
	spin_lock_bh(&ssi->lock);
	del_timer(&ssi->rx_wd);
	del_timer(&ssi->tx_wd);
	del_timer(&ssi->keep_alive);
	ssi->main_state = 0;
	ssi->send_state = 0;
	ssi->recv_state = 0;
	ssi->flags = 0;
	ssi->rxid = 0;
	ssi->txid = 0;
	list_for_each_safe(head, tmp, &ssi->txqueue) {
		msg = list_entry(head, struct hsi_msg, link);
		dev_dbg(&cl->device, "Pending TX data\n");
		list_del(head);
		ssip_free_data(msg);
	}
	ssi->txqueue_len = 0;
	spin_unlock_bh(&ssi->lock);
}

static void ssip_dump_state(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	spin_lock_bh(&ssi->lock);
	dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
	dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
	dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
	dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
							"Online" : "Offline");
	dev_err(&cl->device, "Wake test %d\n",
				test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
	dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
	dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);

	list_for_each_entry(msg, &ssi->txqueue, link)
		dev_err(&cl->device, "pending TX data (%p)\n", msg);
	spin_unlock_bh(&ssi->lock);
}

static void ssip_error(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	ssip_dump_state(cl);
	ssip_reset(cl);
	msg = ssip_claim_cmd(ssi);
	msg->complete = ssip_rxcmd_complete;
	hsi_async_read(cl, msg);
}

static void ssip_keep_alive(unsigned long data)
{
	struct hsi_client *cl = (struct hsi_client *)data;
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
		ssi->main_state, ssi->recv_state, ssi->send_state);

	spin_lock(&ssi->lock);
	if (ssi->recv_state == RECV_IDLE)
		switch (ssi->send_state) {
		case SEND_READY:
			if (atomic_read(&ssi->tx_usecnt) == 0)
				break;
			/*
			 * Fall through. Workaround for cmt-speech
			 * in that case we relay on audio timers.
			 */
		case SEND_IDLE:
			spin_unlock(&ssi->lock);
			return;
		}
	mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
	spin_unlock(&ssi->lock);
}

static void ssip_wd(unsigned long data)
{
	struct hsi_client *cl = (struct hsi_client *)data;

	dev_err(&cl->device, "Watchdog trigerred\n");
	ssip_error(cl);
}

static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
	msg = ssip_claim_cmd(ssi);
	ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
	msg->complete = ssip_release_cmd;
	hsi_async_write(cl, msg);
	dev_dbg(&cl->device, "Issuing RX command\n");
	msg = ssip_claim_cmd(ssi);
	msg->complete = ssip_rxcmd_complete;
	hsi_async_read(cl, msg);
}

static void ssip_start_rx(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
						ssi->recv_state);
	spin_lock_bh(&ssi->lock);
	/*
	 * We can have two UP events in a row due to a short low
	 * high transition. Therefore we need to ignore the sencond UP event.
	 */
	if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
		spin_unlock_bh(&ssi->lock);
		return;
	}
	ssip_set_rxstate(ssi, RECV_READY);
	spin_unlock_bh(&ssi->lock);

	msg = ssip_claim_cmd(ssi);
	ssip_set_cmd(msg, SSIP_READY_CMD);
	msg->complete = ssip_release_cmd;
	dev_dbg(&cl->device, "Send READY\n");
	hsi_async_write(cl, msg);
}

static void ssip_stop_rx(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
	spin_lock_bh(&ssi->lock);
	if (likely(ssi->main_state == ACTIVE))
		ssip_set_rxstate(ssi, RECV_IDLE);
	spin_unlock_bh(&ssi->lock);
}

static void ssip_free_strans(struct hsi_msg *msg)
{
	ssip_free_data(msg->context);
	ssip_release_cmd(msg);
}

static void ssip_strans_complete(struct hsi_msg *msg)
{
	struct hsi_client *cl = msg->cl;
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *data;

	data = msg->context;
	ssip_release_cmd(msg);
	spin_lock_bh(&ssi->lock);
	ssip_set_txstate(ssi, SENDING);
	spin_unlock_bh(&ssi->lock);
	hsi_async_write(cl, data);
}

static int ssip_xmit(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg, *dmsg;
	struct sk_buff *skb;

	spin_lock_bh(&ssi->lock);
	if (list_empty(&ssi->txqueue)) {
		spin_unlock_bh(&ssi->lock);
		return 0;
	}
	dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
	list_del(&dmsg->link);
	ssi->txqueue_len--;
	spin_unlock_bh(&ssi->lock);

	msg = ssip_claim_cmd(ssi);
	skb = dmsg->context;
	msg->context = dmsg;
	msg->complete = ssip_strans_complete;
	msg->destructor = ssip_free_strans;

	spin_lock_bh(&ssi->lock);
	ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
								ssi->txid));
	ssi->txid++;
	ssip_set_txstate(ssi, SENDING);
	spin_unlock_bh(&ssi->lock);

	dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
						SSIP_BYTES_TO_FRAMES(skb->len));

	return hsi_async_write(cl, msg);
}

/* In soft IRQ context */
static void ssip_pn_rx(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;

	if (unlikely(!netif_running(dev))) {
		dev_dbg(&dev->dev, "Drop RX packet\n");
		dev->stats.rx_dropped++;
		dev_kfree_skb(skb);
		return;
	}
	if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
		dev_dbg(&dev->dev, "Error drop RX packet\n");
		dev->stats.rx_errors++;
		dev->stats.rx_length_errors++;
		dev_kfree_skb(skb);
		return;
	}
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += skb->len;

	/* length field is exchanged in network byte order */
	((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
	dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
			((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));

	skb->protocol = htons(ETH_P_PHONET);
	skb_reset_mac_header(skb);
	__skb_pull(skb, 1);
	netif_rx(skb);
}

static void ssip_rx_data_complete(struct hsi_msg *msg)
{
	struct hsi_client *cl = msg->cl;
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct sk_buff *skb;

	if (msg->status == HSI_STATUS_ERROR) {
		dev_err(&cl->device, "RX data error\n");
		ssip_free_data(msg);
		ssip_error(cl);
		return;
	}
	del_timer(&ssi->rx_wd); /* FIXME: Revisit */
	skb = msg->context;
	ssip_pn_rx(skb);
	hsi_free_msg(msg);
}

static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	/* Workaroud: Ignore CMT Loader message leftover */
	if (cmd == SSIP_CMT_LOADER_SYNC)
		return;

	switch (ssi->main_state) {
	case ACTIVE:
		dev_err(&cl->device, "Boot info req on active state\n");
		ssip_error(cl);
		/* Fall through */
	case INIT:
	case HANDSHAKE:
		spin_lock_bh(&ssi->lock);
		ssi->main_state = HANDSHAKE;
		spin_unlock_bh(&ssi->lock);

		if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
			ssi_waketest(cl, 1); /* FIXME: To be removed */

		spin_lock_bh(&ssi->lock);
		/* Start boot handshake watchdog */
		mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
		spin_unlock_bh(&ssi->lock);
		dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
		if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
			dev_warn(&cl->device, "boot info req verid mismatch\n");
		msg = ssip_claim_cmd(ssi);
		ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
		msg->complete = ssip_release_cmd;
		hsi_async_write(cl, msg);
		break;
	default:
		dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
		break;
	}
}

static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
		dev_warn(&cl->device, "boot info resp verid mismatch\n");

	spin_lock_bh(&ssi->lock);
	if (ssi->main_state != ACTIVE)
		/* Use tx_wd as a boot watchdog in non ACTIVE state */
		mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
	else
		dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
							ssi->main_state);
	spin_unlock_bh(&ssi->lock);
}

static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	unsigned int wkres = SSIP_PAYLOAD(cmd);

	spin_lock_bh(&ssi->lock);
	if (ssi->main_state != HANDSHAKE) {
		dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
							ssi->main_state);
		spin_unlock_bh(&ssi->lock);
		return;
	}
	spin_unlock_bh(&ssi->lock);

	if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
		ssi_waketest(cl, 0); /* FIXME: To be removed */

	spin_lock_bh(&ssi->lock);
	ssi->main_state = ACTIVE;
	del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
	spin_unlock_bh(&ssi->lock);

	dev_notice(&cl->device, "WAKELINES TEST %s\n",
				wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
	if (wkres & SSIP_WAKETEST_FAILED) {
		ssip_error(cl);
		return;
	}
	dev_dbg(&cl->device, "CMT is ONLINE\n");
	netif_wake_queue(ssi->netdev);
	netif_carrier_on(ssi->netdev);
}

static void ssip_rx_ready(struct hsi_client *cl)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	spin_lock_bh(&ssi->lock);
	if (unlikely(ssi->main_state != ACTIVE)) {
		dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
					ssi->send_state, ssi->main_state);
		spin_unlock_bh(&ssi->lock);
		return;
	}
	if (ssi->send_state != WAIT4READY) {
		dev_dbg(&cl->device, "Ignore spurious READY command\n");
		spin_unlock_bh(&ssi->lock);
		return;
	}
	ssip_set_txstate(ssi, SEND_READY);
	spin_unlock_bh(&ssi->lock);
	ssip_xmit(cl);
}

static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct sk_buff *skb;
	struct hsi_msg *msg;
	int len = SSIP_PDU_LENGTH(cmd);

	dev_dbg(&cl->device, "RX strans: %d frames\n", len);
	spin_lock_bh(&ssi->lock);
	if (unlikely(ssi->main_state != ACTIVE)) {
		dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
					ssi->send_state, ssi->main_state);
		spin_unlock_bh(&ssi->lock);
		return;
	}
	ssip_set_rxstate(ssi, RECEIVING);
	if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
		dev_err(&cl->device, "START TRANS id %d expected %d\n",
					SSIP_MSG_ID(cmd), ssi->rxid);
		spin_unlock_bh(&ssi->lock);
		goto out1;
	}
	ssi->rxid++;
	spin_unlock_bh(&ssi->lock);
	skb = netdev_alloc_skb(ssi->netdev, len * 4);
	if (unlikely(!skb)) {
		dev_err(&cl->device, "No memory for rx skb\n");
		goto out1;
	}
	skb->dev = ssi->netdev;
	skb_put(skb, len * 4);
	msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
	if (unlikely(!msg)) {
		dev_err(&cl->device, "No memory for RX data msg\n");
		goto out2;
	}
	msg->complete = ssip_rx_data_complete;
	hsi_async_read(cl, msg);

	return;
out2:
	dev_kfree_skb(skb);
out1:
	ssip_error(cl);
}

static void ssip_rxcmd_complete(struct hsi_msg *msg)
{
	struct hsi_client *cl = msg->cl;
	u32 cmd = ssip_get_cmd(msg);
	unsigned int cmdid = SSIP_COMMAND(cmd);

	if (msg->status == HSI_STATUS_ERROR) {
		dev_err(&cl->device, "RX error detected\n");
		ssip_release_cmd(msg);
		ssip_error(cl);
		return;
	}
	hsi_async_read(cl, msg);
	dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
	switch (cmdid) {
	case SSIP_SW_BREAK:
		/* Ignored */
		break;
	case SSIP_BOOTINFO_REQ:
		ssip_rx_bootinforeq(cl, cmd);
		break;
	case SSIP_BOOTINFO_RESP:
		ssip_rx_bootinforesp(cl, cmd);
		break;
	case SSIP_WAKETEST_RESULT:
		ssip_rx_waketest(cl, cmd);
		break;
	case SSIP_START_TRANS:
		ssip_rx_strans(cl, cmd);
		break;
	case SSIP_READY:
		ssip_rx_ready(cl);
		break;
	default:
		dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
		break;
	}
}

static void ssip_swbreak_complete(struct hsi_msg *msg)
{
	struct hsi_client *cl = msg->cl;
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	ssip_release_cmd(msg);
	spin_lock_bh(&ssi->lock);
	if (list_empty(&ssi->txqueue)) {
		if (atomic_read(&ssi->tx_usecnt)) {
			ssip_set_txstate(ssi, SEND_READY);
		} else {
			ssip_set_txstate(ssi, SEND_IDLE);
			hsi_stop_tx(cl);
		}
		spin_unlock_bh(&ssi->lock);
	} else {
		spin_unlock_bh(&ssi->lock);
		ssip_xmit(cl);
	}
	netif_wake_queue(ssi->netdev);
}

static void ssip_tx_data_complete(struct hsi_msg *msg)
{
	struct hsi_client *cl = msg->cl;
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *cmsg;

	if (msg->status == HSI_STATUS_ERROR) {
		dev_err(&cl->device, "TX data error\n");
		ssip_error(cl);
		goto out;
	}
	spin_lock_bh(&ssi->lock);
	if (list_empty(&ssi->txqueue)) {
		ssip_set_txstate(ssi, SENDING_SWBREAK);
		spin_unlock_bh(&ssi->lock);
		cmsg = ssip_claim_cmd(ssi);
		ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
		cmsg->complete = ssip_swbreak_complete;
		dev_dbg(&cl->device, "Send SWBREAK\n");
		hsi_async_write(cl, cmsg);
	} else {
		spin_unlock_bh(&ssi->lock);
		ssip_xmit(cl);
	}
out:
	ssip_free_data(msg);
}

static void ssip_port_event(struct hsi_client *cl, unsigned long event)
{
	switch (event) {
	case HSI_EVENT_START_RX:
		ssip_start_rx(cl);
		break;
	case HSI_EVENT_STOP_RX:
		ssip_stop_rx(cl);
		break;
	default:
		return;
	}
}

static int ssip_pn_open(struct net_device *dev)
{
	struct hsi_client *cl = to_hsi_client(dev->dev.parent);
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	int err;

	err = hsi_claim_port(cl, 1);
	if (err < 0) {
		dev_err(&cl->device, "SSI port already claimed\n");
		return err;
	}
	err = hsi_register_port_event(cl, ssip_port_event);
	if (err < 0) {
		dev_err(&cl->device, "Register HSI port event failed (%d)\n",
			err);
		return err;
	}
	dev_dbg(&cl->device, "Configuring SSI port\n");
	hsi_setup(cl);

	if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
		ssi_waketest(cl, 1); /* FIXME: To be removed */

	spin_lock_bh(&ssi->lock);
	ssi->main_state = HANDSHAKE;
	spin_unlock_bh(&ssi->lock);

	ssip_send_bootinfo_req_cmd(cl);

	return 0;
}

static int ssip_pn_stop(struct net_device *dev)
{
	struct hsi_client *cl = to_hsi_client(dev->dev.parent);

	ssip_reset(cl);
	hsi_unregister_port_event(cl);
	hsi_release_port(cl);

	return 0;
}

static void ssip_xmit_work(struct work_struct *work)
{
	struct ssi_protocol *ssi =
				container_of(work, struct ssi_protocol, work);
	struct hsi_client *cl = ssi->cl;

	ssip_xmit(cl);
}

static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hsi_client *cl = to_hsi_client(dev->dev.parent);
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	if ((skb->protocol != htons(ETH_P_PHONET)) ||
					(skb->len < SSIP_MIN_PN_HDR))
		goto drop;
	/* Pad to 32-bits - FIXME: Revisit*/
	if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
		goto drop;

	/*
	 * Modem sends Phonet messages over SSI with its own endianess...
	 * Assume that modem has the same endianess as we do.
	 */
	if (skb_cow_head(skb, 0))
		goto drop;

	/* length field is exchanged in network byte order */
	((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);

	msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
	if (!msg) {
		dev_dbg(&cl->device, "Dropping tx data: No memory\n");
		goto drop;
	}
	msg->complete = ssip_tx_data_complete;

	spin_lock_bh(&ssi->lock);
	if (unlikely(ssi->main_state != ACTIVE)) {
		spin_unlock_bh(&ssi->lock);
		dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
		goto drop2;
	}
	list_add_tail(&msg->link, &ssi->txqueue);
	ssi->txqueue_len++;
	if (dev->tx_queue_len < ssi->txqueue_len) {
		dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
		netif_stop_queue(dev);
	}
	if (ssi->send_state == SEND_IDLE) {
		ssip_set_txstate(ssi, WAIT4READY);
		spin_unlock_bh(&ssi->lock);
		dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
		hsi_start_tx(cl);
	} else if (ssi->send_state == SEND_READY) {
		/* Needed for cmt-speech workaround */
		dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
							ssi->txqueue_len);
		spin_unlock_bh(&ssi->lock);
		schedule_work(&ssi->work);
	} else {
		spin_unlock_bh(&ssi->lock);
	}
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	return 0;
drop2:
	hsi_free_msg(msg);
drop:
	dev->stats.tx_dropped++;
	dev_kfree_skb(skb);

	return 0;
}

/* CMT reset event handler */
void ssip_reset_event(struct hsi_client *master)
{
	struct ssi_protocol *ssi = hsi_client_drvdata(master);
	dev_err(&ssi->cl->device, "CMT reset detected!\n");
	ssip_error(ssi->cl);
}
EXPORT_SYMBOL_GPL(ssip_reset_event);

static const struct net_device_ops ssip_pn_ops = {
	.ndo_open	= ssip_pn_open,
	.ndo_stop	= ssip_pn_stop,
	.ndo_start_xmit	= ssip_pn_xmit,
};

static void ssip_pn_setup(struct net_device *dev)
{
	dev->features		= 0;
	dev->netdev_ops		= &ssip_pn_ops;
	dev->type		= ARPHRD_PHONET;
	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
	dev->mtu		= SSIP_DEFAULT_MTU;
	dev->hard_header_len	= 1;
	dev->dev_addr[0]	= PN_MEDIA_SOS;
	dev->addr_len		= 1;
	dev->tx_queue_len	= SSIP_TXQUEUE_LEN;

	dev->destructor		= free_netdev;
	dev->header_ops		= &phonet_header_ops;
}

static int ssi_protocol_probe(struct device *dev)
{
	static const char ifname[] = "phonet%d";
	struct hsi_client *cl = to_hsi_client(dev);
	struct ssi_protocol *ssi;
	int err;

	ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
	if (!ssi) {
		dev_err(dev, "No memory for ssi protocol\n");
		return -ENOMEM;
	}

	spin_lock_init(&ssi->lock);
	init_timer_deferrable(&ssi->rx_wd);
	init_timer_deferrable(&ssi->tx_wd);
	init_timer(&ssi->keep_alive);
	ssi->rx_wd.data = (unsigned long)cl;
	ssi->rx_wd.function = ssip_wd;
	ssi->tx_wd.data = (unsigned long)cl;
	ssi->tx_wd.function = ssip_wd;
	ssi->keep_alive.data = (unsigned long)cl;
	ssi->keep_alive.function = ssip_keep_alive;
	INIT_LIST_HEAD(&ssi->txqueue);
	INIT_LIST_HEAD(&ssi->cmdqueue);
	atomic_set(&ssi->tx_usecnt, 0);
	hsi_client_set_drvdata(cl, ssi);
	ssi->cl = cl;
	INIT_WORK(&ssi->work, ssip_xmit_work);

	ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
	if (ssi->channel_id_cmd < 0) {
		err = ssi->channel_id_cmd;
		dev_err(dev, "Could not get cmd channel (%d)\n", err);
		goto out;
	}

	ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
	if (ssi->channel_id_data < 0) {
		err = ssi->channel_id_data;
		dev_err(dev, "Could not get data channel (%d)\n", err);
		goto out;
	}

	err = ssip_alloc_cmds(ssi);
	if (err < 0) {
		dev_err(dev, "No memory for commands\n");
		goto out;
	}

	ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
	if (!ssi->netdev) {
		dev_err(dev, "No memory for netdev\n");
		err = -ENOMEM;
		goto out1;
	}

	/* MTU range: 6 - 65535 */
	ssi->netdev->min_mtu = PHONET_MIN_MTU;
	ssi->netdev->max_mtu = SSIP_MAX_MTU;

	SET_NETDEV_DEV(ssi->netdev, dev);
	netif_carrier_off(ssi->netdev);
	err = register_netdev(ssi->netdev);
	if (err < 0) {
		dev_err(dev, "Register netdev failed (%d)\n", err);
		goto out2;
	}

	list_add(&ssi->link, &ssip_list);

	dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
		ssi->channel_id_cmd, ssi->channel_id_data);

	return 0;
out2:
	free_netdev(ssi->netdev);
out1:
	ssip_free_cmds(ssi);
out:
	kfree(ssi);

	return err;
}

static int ssi_protocol_remove(struct device *dev)
{
	struct hsi_client *cl = to_hsi_client(dev);
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);

	list_del(&ssi->link);
	unregister_netdev(ssi->netdev);
	ssip_free_cmds(ssi);
	hsi_client_set_drvdata(cl, NULL);
	kfree(ssi);

	return 0;
}

static struct hsi_client_driver ssip_driver = {
	.driver = {
		.name	= "ssi-protocol",
		.owner	= THIS_MODULE,
		.probe	= ssi_protocol_probe,
		.remove	= ssi_protocol_remove,
	},
};

static int __init ssip_init(void)
{
	pr_info("SSI protocol aka McSAAB added\n");

	return hsi_register_client_driver(&ssip_driver);
}
module_init(ssip_init);

static void __exit ssip_exit(void)
{
	hsi_unregister_client_driver(&ssip_driver);
	pr_info("SSI protocol driver removed\n");
}
module_exit(ssip_exit);

MODULE_ALIAS("hsi:ssi-protocol");
MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
MODULE_LICENSE("GPL");

Privacy Policy