aboutsummaryrefslogtreecommitdiff
path: root/drivers/most/most_usb.c
blob: acabb7715b42327e5cd7a2aa70e01c161ca173b5 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * usb.c - Hardware dependent module for USB
 *
 * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/completion.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/sysfs.h>
#include <linux/dma-mapping.h>
#include <linux/etherdevice.h>
#include <linux/uaccess.h>
#include <linux/most.h>

#define USB_MTU			512
#define NO_ISOCHRONOUS_URB	0
#define AV_PACKETS_PER_XACT	2
#define BUF_CHAIN_SIZE		0xFFFF
#define MAX_NUM_ENDPOINTS	30
#define MAX_SUFFIX_LEN		10
#define MAX_STRING_LEN		80
#define MAX_BUF_SIZE		0xFFFF

#define USB_VENDOR_ID_SMSC	0x0424  /* VID: SMSC */
#define USB_DEV_ID_BRDG		0xC001  /* PID: USB Bridge */
#define USB_DEV_ID_OS81118	0xCF18  /* PID: USB OS81118 */
#define USB_DEV_ID_OS81119	0xCF19  /* PID: USB OS81119 */
#define USB_DEV_ID_OS81210	0xCF30  /* PID: USB OS81210 */
/* DRCI Addresses */
#define DRCI_REG_NI_STATE	0x0100
#define DRCI_REG_PACKET_BW	0x0101
#define DRCI_REG_NODE_ADDR	0x0102
#define DRCI_REG_NODE_POS	0x0103
#define DRCI_REG_MEP_FILTER	0x0140
#define DRCI_REG_HASH_TBL0	0x0141
#define DRCI_REG_HASH_TBL1	0x0142
#define DRCI_REG_HASH_TBL2	0x0143
#define DRCI_REG_HASH_TBL3	0x0144
#define DRCI_REG_HW_ADDR_HI	0x0145
#define DRCI_REG_HW_ADDR_MI	0x0146
#define DRCI_REG_HW_ADDR_LO	0x0147
#define DRCI_REG_BASE		0x1100
#define DRCI_COMMAND		0x02
#define DRCI_READ_REQ		0xA0
#define DRCI_WRITE_REQ		0xA1

/**
 * struct most_dci_obj - Direct Communication Interface
 * @kobj:position in sysfs
 * @usb_device: pointer to the usb device
 * @reg_addr: register address for arbitrary DCI access
 */
struct most_dci_obj {
	struct device dev;
	struct usb_device *usb_device;
	u16 reg_addr;
};

#define to_dci_obj(p) container_of(p, struct most_dci_obj, dev)

struct most_dev;

struct clear_hold_work {
	struct work_struct ws;
	struct most_dev *mdev;
	unsigned int channel;
	int pipe;
};

#define to_clear_hold_work(w) container_of(w, struct clear_hold_work, ws)

/**
 * struct most_dev - holds all usb interface specific stuff
 * @usb_device: pointer to usb device
 * @iface: hardware interface
 * @cap: channel capabilities
 * @conf: channel configuration
 * @dci: direct communication interface of hardware
 * @ep_address: endpoint address table
 * @description: device description
 * @suffix: suffix for channel name
 * @channel_lock: synchronize channel access
 * @padding_active: indicates channel uses padding
 * @is_channel_healthy: health status table of each channel
 * @busy_urbs: list of anchored items
 * @io_mutex: synchronize I/O with disconnect
 * @link_stat_timer: timer for link status reports
 * @poll_work_obj: work for polling link status
 */
struct most_dev {
	struct device dev;
	struct usb_device *usb_device;
	struct most_interface iface;
	struct most_channel_capability *cap;
	struct most_channel_config *conf;
	struct most_dci_obj *dci;
	u8 *ep_address;
	char description[MAX_STRING_LEN];
	char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
	spinlock_t channel_lock[MAX_NUM_ENDPOINTS]; /* sync channel access */
	bool padding_active[MAX_NUM_ENDPOINTS];
	bool is_channel_healthy[MAX_NUM_ENDPOINTS];
	struct clear_hold_work clear_work[MAX_NUM_ENDPOINTS];
	struct usb_anchor *busy_urbs;
	struct mutex io_mutex;
	struct timer_list link_stat_timer;
	struct work_struct poll_work_obj;
	void (*on_netinfo)(struct most_interface *most_iface,
			   unsigned char link_state, unsigned char *addrs);
};

#define to_mdev(d) container_of(d, struct most_dev, iface)
#define to_mdev_from_dev(d) container_of(d, struct most_dev, dev)
#define to_mdev_from_work(w) container_of(w, struct most_dev, poll_work_obj)

static void wq_clear_halt(struct work_struct *wq_obj);
static void wq_netinfo(struct work_struct *wq_obj);

/**
 * drci_rd_reg - read a DCI register
 * @dev: usb device
 * @reg: register address
 * @buf: buffer to store data
 *
 * This is reads data from INIC's direct register communication interface
 */
static inline int drci_rd_reg(struct usb_device *dev, u16 reg, u16 *buf)
{
	int retval;
	__le16 *dma_buf;
	u8 req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE;

	dma_buf = kzalloc(sizeof(*dma_buf), GFP_KERNEL);
	if (!dma_buf)
		return -ENOMEM;

	retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
				 DRCI_READ_REQ, req_type,
				 0x0000,
				 reg, dma_buf, sizeof(*dma_buf),
				 USB_CTRL_GET_TIMEOUT);
	*buf = le16_to_cpu(*dma_buf);
	kfree(dma_buf);

	if (retval < 0)
		return retval;
	return 0;
}

/**
 * drci_wr_reg - write a DCI register
 * @dev: usb device
 * @reg: register address
 * @data: data to write
 *
 * This is writes data to INIC's direct register communication interface
 */
static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
{
	return usb_control_msg(dev,
			       usb_sndctrlpipe(dev, 0),
			       DRCI_WRITE_REQ,
			       USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			       data,
			       reg,
			       NULL,
			       0,
			       USB_CTRL_SET_TIMEOUT);
}

static inline int start_sync_ep(struct usb_device *usb_dev, u16 ep)
{
	return drci_wr_reg(usb_dev, DRCI_REG_BASE + DRCI_COMMAND + ep * 16, 1);
}

/**
 * get_stream_frame_size - calculate frame size of current configuration
 * @dev: device structure
 * @cfg: channel configuration
 */
static unsigned int get_stream_frame_size(struct device *dev,
					  struct most_channel_config *cfg)
{
	unsigned int frame_size;
	unsigned int sub_size = cfg->subbuffer_size;

	if (!sub_size) {
		dev_warn(dev, "Misconfig: Subbuffer size zero.\n");
		return 0;
	}
	switch (cfg->data_type) {
	case MOST_CH_ISOC:
		frame_size = AV_PACKETS_PER_XACT * sub_size;
		break;
	case MOST_CH_SYNC:
		if (cfg->packets_per_xact == 0) {
			dev_warn(dev, "Misconfig: Packets per XACT zero\n");
			frame_size = 0;
		} else if (cfg->packets_per_xact == 0xFF) {
			frame_size = (USB_MTU / sub_size) * sub_size;
		} else {
			frame_size = cfg->packets_per_xact * sub_size;
		}
		break;
	default:
		dev_warn(dev, "Query frame size of non-streaming channel\n");
		frame_size = 0;
		break;
	}
	return frame_size;
}

/**
 * hdm_poison_channel - mark buffers of this channel as invalid
 * @iface: pointer to the interface
 * @channel: channel ID
 *
 * This unlinks all URBs submitted to the HCD,
 * calls the associated completion function of the core and removes
 * them from the list.
 *
 * Returns 0 on success or error code otherwise.
 */
static int hdm_poison_channel(struct most_interface *iface, int channel)
{
	struct most_dev *mdev = to_mdev(iface);
	unsigned long flags;
	spinlock_t *lock; /* temp. lock */

	if (channel < 0 || channel >= iface->num_channels) {
		dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
		return -ECHRNG;
	}

	lock = mdev->channel_lock + channel;
	spin_lock_irqsave(lock, flags);
	mdev->is_channel_healthy[channel] = false;
	spin_unlock_irqrestore(lock, flags);

	cancel_work_sync(&mdev->clear_work[channel].ws);

	mutex_lock(&mdev->io_mutex);
	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
	if (mdev->padding_active[channel])
		mdev->padding_active[channel] = false;

	if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
		del_timer_sync(&mdev->link_stat_timer);
		cancel_work_sync(&mdev->poll_work_obj);
	}
	mutex_unlock(&mdev->io_mutex);
	return 0;
}

/**
 * hdm_add_padding - add padding bytes
 * @mdev: most device
 * @channel: channel ID
 * @mbo: buffer object
 *
 * This inserts the INIC hardware specific padding bytes into a streaming
 * channel's buffer
 */
static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
{
	struct most_channel_config *conf = &mdev->conf[channel];
	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
	unsigned int j, num_frames;

	if (!frame_size)
		return -EINVAL;
	num_frames = mbo->buffer_length / frame_size;

	if (num_frames < 1) {
		dev_err(&mdev->usb_device->dev,
			"Missed minimal transfer unit.\n");
		return -EINVAL;
	}

	for (j = num_frames - 1; j > 0; j--)
		memmove(mbo->virt_address + j * USB_MTU,
			mbo->virt_address + j * frame_size,
			frame_size);
	mbo->buffer_length = num_frames * USB_MTU;
	return 0;
}

/**
 * hdm_remove_padding - remove padding bytes
 * @mdev: most device
 * @channel: channel ID
 * @mbo: buffer object
 *
 * This takes the INIC hardware specific padding bytes off a streaming
 * channel's buffer.
 */
static int hdm_remove_padding(struct most_dev *mdev, int channel,
			      struct mbo *mbo)
{
	struct most_channel_config *const conf = &mdev->conf[channel];
	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
	unsigned int j, num_frames;

	if (!frame_size)
		return -EINVAL;
	num_frames = mbo->processed_length / USB_MTU;

	for (j = 1; j < num_frames; j++)
		memmove(mbo->virt_address + frame_size * j,
			mbo->virt_address + USB_MTU * j,
			frame_size);

	mbo->processed_length = frame_size * num_frames;
	return 0;
}

/**
 * hdm_write_completion - completion function for submitted Tx URBs
 * @urb: the URB that has been completed
 *
 * This checks the status of the completed URB. In case the URB has been
 * unlinked before, it is immediately freed. On any other error the MBO
 * transfer flag is set. On success it frees allocated resources and calls
 * the completion function.
 *
 * Context: interrupt!
 */
static void hdm_write_completion(struct urb *urb)
{
	struct mbo *mbo = urb->context;
	struct most_dev *mdev = to_mdev(mbo->ifp);
	unsigned int channel = mbo->hdm_channel_id;
	spinlock_t *lock = mdev->channel_lock + channel;
	unsigned long flags;

	spin_lock_irqsave(lock, flags);

	mbo->processed_length = 0;
	mbo->status = MBO_E_INVAL;
	if (likely(mdev->is_channel_healthy[channel])) {
		switch (urb->status) {
		case 0:
		case -ESHUTDOWN:
			mbo->processed_length = urb->actual_length;
			mbo->status = MBO_SUCCESS;
			break;
		case -EPIPE:
			dev_warn(&mdev->usb_device->dev,
				 "Broken pipe on ep%02x\n",
				 mdev->ep_address[channel]);
			mdev->is_channel_healthy[channel] = false;
			mdev->clear_work[channel].pipe = urb->pipe;
			schedule_work(&mdev->clear_work[channel].ws);
			break;
		case -ENODEV:
		case -EPROTO:
			mbo->status = MBO_E_CLOSE;
			break;
		}
	}

	spin_unlock_irqrestore(lock, flags);

	if (likely(mbo->complete))
		mbo->complete(mbo);
	usb_free_urb(urb);
}

/**
 * hdm_read_completion - completion function for submitted Rx URBs
 * @urb: the URB that has been completed
 *
 * This checks the status of the completed URB. In case the URB has been
 * unlinked before it is immediately freed. On any other error the MBO transfer
 * flag is set. On success it frees allocated resources, removes
 * padding bytes -if necessary- and calls the completion function.
 *
 * Context: interrupt!
 */
static void hdm_read_completion(struct urb *urb)
{
	struct mbo *mbo = urb->context;
	struct most_dev *mdev = to_mdev(mbo->ifp);
	unsigned int channel = mbo->hdm_channel_id;
	struct device *dev = &mdev->usb_device->dev;
	spinlock_t *lock = mdev->channel_lock + channel;
	unsigned long flags;

	spin_lock_irqsave(lock, flags);

	mbo->processed_length = 0;
	mbo->status = MBO_E_INVAL;
	if (likely(mdev->is_channel_healthy[channel])) {
		switch (urb->status) {
		case 0:
		case -ESHUTDOWN:
			mbo->processed_length = urb->actual_length;
			mbo->status = MBO_SUCCESS;
			if (mdev->padding_active[channel] &&
			    hdm_remove_padding(mdev, channel, mbo)) {
				mbo->processed_length = 0;
				mbo->status = MBO_E_INVAL;
			}
			break;
		case -EPIPE:
			dev_warn(dev, "Broken pipe on ep%02x\n",
				 mdev->ep_address[channel]);
			mdev->is_channel_healthy[channel] = false;
			mdev->clear_work[channel].pipe = urb->pipe;
			schedule_work(&mdev->clear_work[channel].ws);
			break;
		case -ENODEV:
		case -EPROTO:
			mbo->status = MBO_E_CLOSE;
			break;
		case -EOVERFLOW:
			dev_warn(dev, "Babble on ep%02x\n",
				 mdev->ep_address[channel]);
			break;
		}
	}

	spin_unlock_irqrestore(lock, flags);

	if (likely(mbo->complete))
		mbo->complete(mbo);
	usb_free_urb(urb);
}

/**
 * hdm_enqueue - receive a buffer to be used for data transfer
 * @iface: interface to enqueue to
 * @channel: ID of the channel
 * @mbo: pointer to the buffer object
 *
 * This allocates a new URB and fills it according to the channel
 * that is being used for transmission of data. Before the URB is
 * submitted it is stored in the private anchor list.
 *
 * Returns 0 on success. On any error the URB is freed and a error code
 * is returned.
 *
 * Context: Could in _some_ cases be interrupt!
 */
static int hdm_enqueue(struct most_interface *iface, int channel,
		       struct mbo *mbo)
{
	struct most_dev *mdev = to_mdev(iface);
	struct most_channel_config *conf;
	int retval = 0;
	struct urb *urb;
	unsigned long length;
	void *virt_address;

	if (!mbo)
		return -EINVAL;
	if (iface->num_channels <= channel || channel < 0)
		return -ECHRNG;

	urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_KERNEL);
	if (!urb)
		return -ENOMEM;

	conf = &mdev->conf[channel];

	mutex_lock(&mdev->io_mutex);
	if (!mdev->usb_device) {
		retval = -ENODEV;
		goto err_free_urb;
	}

	if ((conf->direction & MOST_CH_TX) && mdev->padding_active[channel] &&
	    hdm_add_padding(mdev, channel, mbo)) {
		retval = -EINVAL;
		goto err_free_urb;
	}

	urb->transfer_dma = mbo->bus_address;
	virt_address = mbo->virt_address;
	length = mbo->buffer_length;

	if (conf->direction & MOST_CH_TX) {
		usb_fill_bulk_urb(urb, mdev->usb_device,
				  usb_sndbulkpipe(mdev->usb_device,
						  mdev->ep_address[channel]),
				  virt_address,
				  length,
				  hdm_write_completion,
				  mbo);
		if (conf->data_type != MOST_CH_ISOC &&
		    conf->data_type != MOST_CH_SYNC)
			urb->transfer_flags |= URB_ZERO_PACKET;
	} else {
		usb_fill_bulk_urb(urb, mdev->usb_device,
				  usb_rcvbulkpipe(mdev->usb_device,
						  mdev->ep_address[channel]),
				  virt_address,
				  length + conf->extra_len,
				  hdm_read_completion,
				  mbo);
	}
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	usb_anchor_urb(urb, &mdev->busy_urbs[channel]);

	retval = usb_submit_urb(urb, GFP_KERNEL);
	if (retval) {
		dev_err(&mdev->usb_device->dev,
			"URB submit failed with error %d.\n", retval);
		goto err_unanchor_urb;
	}
	mutex_unlock(&mdev->io_mutex);
	return 0;

err_unanchor_urb:
	usb_unanchor_urb(urb);
err_free_urb:
	usb_free_urb(urb);
	mutex_unlock(&mdev->io_mutex);
	return retval;
}

static void *hdm_dma_alloc(struct mbo *mbo, u32 size)
{
	struct most_dev *mdev = to_mdev(mbo->ifp);

	return usb_alloc_coherent(mdev->usb_device, size, GFP_KERNEL,
				  &mbo->bus_address);
}

static void hdm_dma_free(struct mbo *mbo, u32 size)
{
	struct most_dev *mdev = to_mdev(mbo->ifp);

	usb_free_coherent(mdev->usb_device, size, mbo->virt_address,
			  mbo->bus_address);
}

/**
 * hdm_configure_channel - receive channel configuration from core
 * @iface: interface
 * @channel: channel ID
 * @conf: structure that holds the configuration information
 *
 * The attached network interface controller (NIC) supports a padding mode
 * to avoid short packets on USB, hence increasing the performance due to a
 * lower interrupt load. This mode is default for synchronous data and can
 * be switched on for isochronous data. In case padding is active the
 * driver needs to know the frame size of the payload in order to calculate
 * the number of bytes it needs to pad when transmitting or to cut off when
 * receiving data.
 *
 */
static int hdm_configure_channel(struct most_interface *iface, int channel,
				 struct most_channel_config *conf)
{
	unsigned int num_frames;
	unsigned int frame_size;
	struct most_dev *mdev = to_mdev(iface);
	struct device *dev = &mdev->usb_device->dev;

	if (!conf) {
		dev_err(dev, "Bad config pointer.\n");
		return -EINVAL;
	}
	if (channel < 0 || channel >= iface->num_channels) {
		dev_err(dev, "Channel ID out of range.\n");
		return -EINVAL;
	}

	mdev->is_channel_healthy[channel] = true;
	mdev->clear_work[channel].channel = channel;
	mdev->clear_work[channel].mdev = mdev;
	INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);

	if (!conf->num_buffers || !conf->buffer_size) {
		dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
		return -EINVAL;
	}

	if (conf->data_type != MOST_CH_SYNC &&
	    !(conf->data_type == MOST_CH_ISOC &&
	      conf->packets_per_xact != 0xFF)) {
		mdev->padding_active[channel] = false;
		/*
		 * Since the NIC's padding mode is not going to be
		 * used, we can skip the frame size calculations and
		 * move directly on to exit.
		 */
		goto exit;
	}

	mdev->padding_active[channel] = true;

	frame_size = get_stream_frame_size(&mdev->dev, conf);
	if (frame_size == 0 || frame_size > USB_MTU) {
		dev_warn(dev, "Misconfig: frame size wrong\n");
		return -EINVAL;
	}

	num_frames = conf->buffer_size / frame_size;

	if (conf->buffer_size % frame_size) {
		u16 old_size = conf->buffer_size;

		conf->buffer_size = num_frames * frame_size;
		dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
			 mdev->suffix[channel], old_size, conf->buffer_size);
	}

	/* calculate extra length to comply w/ HW padding */
	conf->extra_len = num_frames * (USB_MTU - frame_size);

exit:
	mdev->conf[channel] = *conf;
	if (conf->data_type == MOST_CH_ASYNC) {
		u16 ep = mdev->ep_address[channel];

		if (start_sync_ep(mdev->usb_device, ep) < 0)
			dev_warn(dev, "sync for ep%02x failed", ep);
	}
	return 0;
}

/**
 * hdm_request_netinfo - request network information
 * @iface: pointer to interface
 * @channel: channel ID
 *
 * This is used as trigger to set up the link status timer that
 * polls for the NI state of the INIC every 2 seconds.
 *
 */
static void hdm_request_netinfo(struct most_interface *iface, int channel,
				void (*on_netinfo)(struct most_interface *,
						   unsigned char,
						   unsigned char *))
{
	struct most_dev *mdev = to_mdev(iface);

	mdev->on_netinfo = on_netinfo;
	if (!on_netinfo)
		return;

	mdev->link_stat_timer.expires = jiffies + HZ;
	mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
}

/**
 * link_stat_timer_handler - schedule work obtaining mac address and link status
 * @data: pointer to USB device instance
 *
 * The handler runs in interrupt context. That's why we need to defer the
 * tasks to a work queue.
 */
static void link_stat_timer_handler(struct timer_list *t)
{
	struct most_dev *mdev = from_timer(mdev, t, link_stat_timer);

	schedule_work(&mdev->poll_work_obj);
	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
	add_timer(&mdev->link_stat_timer);
}

/**
 * wq_netinfo - work queue function to deliver latest networking information
 * @wq_obj: object that holds data for our deferred work to do
 *
 * This retrieves the network interface status of the USB INIC
 */
static void wq_netinfo(struct work_struct *wq_obj)
{
	struct most_dev *mdev = to_mdev_from_work(wq_obj);
	struct usb_device *usb_device = mdev->usb_device;
	struct device *dev = &usb_device->dev;
	u16 hi, mi, lo, link;
	u8 hw_addr[6];

	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi)) {
		dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
		return;
	}

	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi)) {
		dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
		return;
	}

	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo)) {
		dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
		return;
	}

	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link)) {
		dev_err(dev, "Vendor request 'link status' failed\n");
		return;
	}

	hw_addr[0] = hi >> 8;
	hw_addr[1] = hi;
	hw_addr[2] = mi >> 8;
	hw_addr[3] = mi;
	hw_addr[4] = lo >> 8;
	hw_addr[5] = lo;

	if (mdev->on_netinfo)
		mdev->on_netinfo(&mdev->iface, link, hw_addr);
}

/**
 * wq_clear_halt - work queue function
 * @wq_obj: work_struct object to execute
 *
 * This sends a clear_halt to the given USB pipe.
 */
static void wq_clear_halt(struct work_struct *wq_obj)
{
	struct clear_hold_work *clear_work = to_clear_hold_work(wq_obj);
	struct most_dev *mdev = clear_work->mdev;
	unsigned int channel = clear_work->channel;
	int pipe = clear_work->pipe;
	int snd_pipe;
	int peer;

	mutex_lock(&mdev->io_mutex);
	most_stop_enqueue(&mdev->iface, channel);
	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
	if (usb_clear_halt(mdev->usb_device, pipe))
		dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");

	/* If the functional Stall condition has been set on an
	 * asynchronous rx channel, we need to clear the tx channel
	 * too, since the hardware runs its clean-up sequence on both
	 * channels, as they are physically one on the network.
	 *
	 * The USB interface that exposes the asynchronous channels
	 * contains always two endpoints, and two only.
	 */
	if (mdev->conf[channel].data_type == MOST_CH_ASYNC &&
	    mdev->conf[channel].direction == MOST_CH_RX) {
		if (channel == 0)
			peer = 1;
		else
			peer = 0;
		snd_pipe = usb_sndbulkpipe(mdev->usb_device,
					   mdev->ep_address[peer]);
		usb_clear_halt(mdev->usb_device, snd_pipe);
	}
	mdev->is_channel_healthy[channel] = true;
	most_resume_enqueue(&mdev->iface, channel);
	mutex_unlock(&mdev->io_mutex);
}

/**
 * hdm_usb_fops - file operation table for USB driver
 */
static const struct file_operations hdm_usb_fops = {
	.owner = THIS_MODULE,
};

/**
 * usb_device_id - ID table for HCD device probing
 */
static const struct usb_device_id usbid[] = {
	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81118), },
	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81119), },
	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81210), },
	{ } /* Terminating entry */
};

struct regs {
	const char *name;
	u16 reg;
};

static const struct regs ro_regs[] = {
	{ "ni_state", DRCI_REG_NI_STATE },
	{ "packet_bandwidth", DRCI_REG_PACKET_BW },
	{ "node_address", DRCI_REG_NODE_ADDR },
	{ "node_position", DRCI_REG_NODE_POS },
};

static const struct regs rw_regs[] = {
	{ "mep_filter", DRCI_REG_MEP_FILTER },
	{ "mep_hash0", DRCI_REG_HASH_TBL0 },
	{ "mep_hash1", DRCI_REG_HASH_TBL1 },
	{ "mep_hash2", DRCI_REG_HASH_TBL2 },
	{ "mep_hash3", DRCI_REG_HASH_TBL3 },
	{ "mep_eui48_hi", DRCI_REG_HW_ADDR_HI },
	{ "mep_eui48_mi", DRCI_REG_HW_ADDR_MI },
	{ "mep_eui48_lo", DRCI_REG_HW_ADDR_LO },
};

static int get_stat_reg_addr(const struct regs *regs, int size,
			     const char *name, u16 *reg_addr)
{
	int i;

	for (i = 0; i < size; i++) {
		if (sysfs_streq(name, regs[i].name)) {
			*reg_addr = regs[i].reg;
			return 0;
		}
	}
	return -EINVAL;
}

#define get_static_reg_addr(regs, name, reg_addr) \
	get_stat_reg_addr(regs, ARRAY_SIZE(regs), name, reg_addr)

static ssize_t value_show(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	const char *name = attr->attr.name;
	struct most_dci_obj *dci_obj = to_dci_obj(dev);
	u16 val;
	u16 reg_addr;
	int err;

	if (sysfs_streq(name, "arb_address"))
		return snprintf(buf, PAGE_SIZE, "%04x\n", dci_obj->reg_addr);

	if (sysfs_streq(name, "arb_value"))
		reg_addr = dci_obj->reg_addr;
	else if (get_static_reg_addr(ro_regs, name, &reg_addr) &&
		 get_static_reg_addr(rw_regs, name, &reg_addr))
		return -EINVAL;

	err = drci_rd_reg(dci_obj->usb_device, reg_addr, &val);
	if (err < 0)
		return err;

	return snprintf(buf, PAGE_SIZE, "%04x\n", val);
}

static ssize_t value_store(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t count)
{
	u16 val;
	u16 reg_addr;
	const char *name = attr->attr.name;
	struct most_dci_obj *dci_obj = to_dci_obj(dev);
	struct usb_device *usb_dev = dci_obj->usb_device;
	int err;

	err = kstrtou16(buf, 16, &val);
	if (err)
		return err;

	if (sysfs_streq(name, "arb_address")) {
		dci_obj->reg_addr = val;
		return count;
	}

	if (sysfs_streq(name, "arb_value"))
		err = drci_wr_reg(usb_dev, dci_obj->reg_addr, val);
	else if (sysfs_streq(name, "sync_ep"))
		err = start_sync_ep(usb_dev, val);
	else if (!get_static_reg_addr(rw_regs, name, &reg_addr))
		err = drci_wr_reg(usb_dev, reg_addr, val);
	else
		return -EINVAL;

	if (err < 0)
		return err;

	return count;
}

static DEVICE_ATTR(ni_state, 0444, value_show, NULL);
static DEVICE_ATTR(packet_bandwidth, 0444, value_show, NULL);
static DEVICE_ATTR(node_address, 0444, value_show, NULL);
static DEVICE_ATTR(node_position, 0444, value_show, NULL);
static DEVICE_ATTR(sync_ep, 0200, NULL, value_store);
static DEVICE_ATTR(mep_filter, 0644, value_show, value_store);
static DEVICE_ATTR(mep_hash0, 0644, value_show, value_store);
static DEVICE_ATTR(mep_hash1, 0644, value_show, value_store);
static DEVICE_ATTR(mep_hash2, 0644, value_show, value_store);
static DEVICE_ATTR(mep_hash3, 0644, value_show, value_store);
static DEVICE_ATTR(mep_eui48_hi, 0644, value_show, value_store);
static DEVICE_ATTR(mep_eui48_mi, 0644, value_show, value_store);
static DEVICE_ATTR(mep_eui48_lo, 0644, value_show, value_store);
static DEVICE_ATTR(arb_address, 0644, value_show, value_store);
static DEVICE_ATTR(arb_value, 0644, value_show, value_store);

static struct attribute *dci_attrs[] = {
	&dev_attr_ni_state.attr,
	&dev_attr_packet_bandwidth.attr,
	&dev_attr_node_address.attr,
	&dev_attr_node_position.attr,
	&dev_attr_sync_ep.attr,
	&dev_attr_mep_filter.attr,
	&dev_attr_mep_hash0.attr,
	&dev_attr_mep_hash1.attr,
	&dev_attr_mep_hash2.attr,
	&dev_attr_mep_hash3.attr,
	&dev_attr_mep_eui48_hi.attr,
	&dev_attr_mep_eui48_mi.attr,
	&dev_attr_mep_eui48_lo.attr,
	&dev_attr_arb_address.attr,
	&dev_attr_arb_value.attr,
	NULL,
};

ATTRIBUTE_GROUPS(dci);

static void release_dci(struct device *dev)
{
	struct most_dci_obj *dci = to_dci_obj(dev);

	put_device(dev->parent);
	kfree(dci);
}

static void release_mdev(struct device *dev)
{
	struct most_dev *mdev = to_mdev_from_dev(dev);

	kfree(mdev);
}
/**
 * hdm_probe - probe function of USB device driver
 * @interface: Interface of the attached USB device
 * @id: Pointer to the USB ID table.
 *
 * This allocates and initializes the device instance, adds the new
 * entry to the internal list, scans the USB descriptors and registers
 * the interface with the core.
 * Additionally, the DCI objects are created and the hardware is sync'd.
 *
 * Return 0 on success. In case of an error a negative number is returned.
 */
static int
hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_host_interface *usb_iface_desc = interface->cur_altsetting;
	struct usb_device *usb_dev = interface_to_usbdev(interface);
	struct device *dev = &usb_dev->dev;
	struct most_dev *mdev;
	unsigned int i;
	unsigned int num_endpoints;
	struct most_channel_capability *tmp_cap;
	struct usb_endpoint_descriptor *ep_desc;
	int ret = -ENOMEM;

	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	if (!mdev)
		return -ENOMEM;

	usb_set_intfdata(interface, mdev);
	num_endpoints = usb_iface_desc->desc.bNumEndpoints;
	if (num_endpoints > MAX_NUM_ENDPOINTS) {
		kfree(mdev);
		return -EINVAL;
	}
	mutex_init(&mdev->io_mutex);
	INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
	timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);

	mdev->usb_device = usb_dev;
	mdev->link_stat_timer.expires = jiffies + (2 * HZ);

	mdev->iface.mod = hdm_usb_fops.owner;
	mdev->iface.dev = &mdev->dev;
	mdev->iface.driver_dev = &interface->dev;
	mdev->iface.interface = ITYPE_USB;
	mdev->iface.configure = hdm_configure_channel;
	mdev->iface.request_netinfo = hdm_request_netinfo;
	mdev->iface.enqueue = hdm_enqueue;
	mdev->iface.poison_channel = hdm_poison_channel;
	mdev->iface.dma_alloc = hdm_dma_alloc;
	mdev->iface.dma_free = hdm_dma_free;
	mdev->iface.description = mdev->description;
	mdev->iface.num_channels = num_endpoints;

	snprintf(mdev->description, sizeof(mdev->description),
		 "%d-%s:%d.%d",
		 usb_dev->bus->busnum,
		 usb_dev->devpath,
		 usb_dev->config->desc.bConfigurationValue,
		 usb_iface_desc->desc.bInterfaceNumber);

	mdev->dev.init_name = mdev->description;
	mdev->dev.parent = &interface->dev;
	mdev->dev.release = release_mdev;
	mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
	if (!mdev->conf)
		goto err_free_mdev;

	mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
	if (!mdev->cap)
		goto err_free_conf;

	mdev->iface.channel_vector = mdev->cap;
	mdev->ep_address =
		kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
	if (!mdev->ep_address)
		goto err_free_cap;

	mdev->busy_urbs =
		kcalloc(num_endpoints, sizeof(*mdev->busy_urbs), GFP_KERNEL);
	if (!mdev->busy_urbs)
		goto err_free_ep_address;

	tmp_cap = mdev->cap;
	for (i = 0; i < num_endpoints; i++) {
		ep_desc = &usb_iface_desc->endpoint[i].desc;
		mdev->ep_address[i] = ep_desc->bEndpointAddress;
		mdev->padding_active[i] = false;
		mdev->is_channel_healthy[i] = true;

		snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
			 mdev->ep_address[i]);

		tmp_cap->name_suffix = &mdev->suffix[i][0];
		tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
		tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
		tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
		tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
		tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
				     MOST_CH_ISOC | MOST_CH_SYNC;
		if (usb_endpoint_dir_in(ep_desc))
			tmp_cap->direction = MOST_CH_RX;
		else
			tmp_cap->direction = MOST_CH_TX;
		tmp_cap++;
		init_usb_anchor(&mdev->busy_urbs[i]);
		spin_lock_init(&mdev->channel_lock[i]);
	}
	dev_dbg(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
		le16_to_cpu(usb_dev->descriptor.idVendor),
		le16_to_cpu(usb_dev->descriptor.idProduct),
		usb_dev->bus->busnum,
		usb_dev->devnum);

	dev_dbg(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
		usb_dev->bus->busnum,
		usb_dev->devpath,
		usb_dev->config->desc.bConfigurationValue,
		usb_iface_desc->desc.bInterfaceNumber);

	ret = most_register_interface(&mdev->iface);
	if (ret)
		goto err_free_busy_urbs;

	mutex_lock(&mdev->io_mutex);
	if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81119 ||
	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81210) {
		mdev->dci = kzalloc(sizeof(*mdev->dci), GFP_KERNEL);
		if (!mdev->dci) {
			mutex_unlock(&mdev->io_mutex);
			most_deregister_interface(&mdev->iface);
			ret = -ENOMEM;
			goto err_free_busy_urbs;
		}

		mdev->dci->dev.init_name = "dci";
		mdev->dci->dev.parent = get_device(mdev->iface.dev);
		mdev->dci->dev.groups = dci_groups;
		mdev->dci->dev.release = release_dci;
		if (device_register(&mdev->dci->dev)) {
			mutex_unlock(&mdev->io_mutex);
			most_deregister_interface(&mdev->iface);
			ret = -ENOMEM;
			goto err_free_dci;
		}
		mdev->dci->usb_device = mdev->usb_device;
	}
	mutex_unlock(&mdev->io_mutex);
	return 0;
err_free_dci:
	put_device(&mdev->dci->dev);
err_free_busy_urbs:
	kfree(mdev->busy_urbs);
err_free_ep_address:
	kfree(mdev->ep_address);
err_free_cap:
	kfree(mdev->cap);
err_free_conf:
	kfree(mdev->conf);
err_free_mdev:
	put_device(&mdev->dev);
	return ret;
}

/**
 * hdm_disconnect - disconnect function of USB device driver
 * @interface: Interface of the attached USB device
 *
 * This deregisters the interface with the core, removes the kernel timer
 * and frees resources.
 *
 * Context: hub kernel thread
 */
static void hdm_disconnect(struct usb_interface *interface)
{
	struct most_dev *mdev = usb_get_intfdata(interface);

	mutex_lock(&mdev->io_mutex);
	usb_set_intfdata(interface, NULL);
	mdev->usb_device = NULL;
	mutex_unlock(&mdev->io_mutex);

	del_timer_sync(&mdev->link_stat_timer);
	cancel_work_sync(&mdev->poll_work_obj);

	if (mdev->dci)
		device_unregister(&mdev->dci->dev);
	most_deregister_interface(&mdev->iface);

	kfree(mdev->busy_urbs);
	kfree(mdev->cap);
	kfree(mdev->conf);
	kfree(mdev->ep_address);
	put_device(&mdev->dci->dev);
	put_device(&mdev->dev);
}

static int hdm_suspend(struct usb_interface *interface, pm_message_t message)
{
	struct most_dev *mdev = usb_get_intfdata(interface);
	int i;

	mutex_lock(&mdev->io_mutex);
	for (i = 0; i < mdev->iface.num_channels; i++) {
		most_stop_enqueue(&mdev->iface, i);
		usb_kill_anchored_urbs(&mdev->busy_urbs[i]);
	}
	mutex_unlock(&mdev->io_mutex);
	return 0;
}

static int hdm_resume(struct usb_interface *interface)
{
	struct most_dev *mdev = usb_get_intfdata(interface);
	int i;

	mutex_lock(&mdev->io_mutex);
	for (i = 0; i < mdev->iface.num_channels; i++)
		most_resume_enqueue(&mdev->iface, i);
	mutex_unlock(&mdev->io_mutex);
	return 0;
}

static struct usb_driver hdm_usb = {
	.name = "hdm_usb",
	.id_table = usbid,
	.probe = hdm_probe,
	.disconnect = hdm_disconnect,
	.resume = hdm_resume,
	.suspend = hdm_suspend,
};

module_usb_driver(hdm_usb);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
MODULE_DESCRIPTION("HDM_4_USB");