aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/c67x00/c67x00-sched.c
blob: aa491627a45ba83b51a881e0f5b7226a26139933 (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
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
/*
 * c67x00-sched.c: Cypress C67X00 USB Host Controller Driver - TD scheduling
 *
 * Copyright (C) 2006-2008 Barco N.V.
 *    Derived from the Cypress cy7c67200/300 ezusb linux driver and
 *    based on multiple host controller drivers inside the linux kernel.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.
 */

#include <linux/kthread.h>
#include <linux/slab.h>

#include "c67x00.h"
#include "c67x00-hcd.h"

/*
 * These are the stages for a control urb, they are kept
 * in both urb->interval and td->privdata.
 */
#define SETUP_STAGE		0
#define DATA_STAGE		1
#define STATUS_STAGE		2

/* -------------------------------------------------------------------------- */

/**
 * struct c67x00_ep_data: Host endpoint data structure
 */
struct c67x00_ep_data {
	struct list_head queue;
	struct list_head node;
	struct usb_host_endpoint *hep;
	struct usb_device *dev;
	u16 next_frame;		/* For int/isoc transactions */
};

/**
 * struct c67x00_td
 *
 * Hardware parts are little endiannes, SW in CPU endianess.
 */
struct c67x00_td {
	/* HW specific part */
	__le16 ly_base_addr;	/* Bytes 0-1 */
	__le16 port_length;	/* Bytes 2-3 */
	u8 pid_ep;		/* Byte 4 */
	u8 dev_addr;		/* Byte 5 */
	u8 ctrl_reg;		/* Byte 6 */
	u8 status;		/* Byte 7 */
	u8 retry_cnt;		/* Byte 8 */
#define TT_OFFSET		2
#define TT_CONTROL		0
#define TT_ISOCHRONOUS		1
#define TT_BULK			2
#define TT_INTERRUPT		3
	u8 residue;		/* Byte 9 */
	__le16 next_td_addr;	/* Bytes 10-11 */
	/* SW part */
	struct list_head td_list;
	u16 td_addr;
	void *data;
	struct urb *urb;
	unsigned long privdata;

	/* These are needed for handling the toggle bits:
	 * an urb can be dequeued while a td is in progress
	 * after checking the td, the toggle bit might need to
	 * be fixed */
	struct c67x00_ep_data *ep_data;
	unsigned int pipe;
};

struct c67x00_urb_priv {
	struct list_head hep_node;
	struct urb *urb;
	int port;
	int cnt;		/* packet number for isoc */
	int status;
	struct c67x00_ep_data *ep_data;
};

#define td_udev(td)	((td)->ep_data->dev)

#define CY_TD_SIZE		12

#define TD_PIDEP_OFFSET		0x04
#define TD_PIDEPMASK_PID	0xF0
#define TD_PIDEPMASK_EP		0x0F
#define TD_PORTLENMASK_DL	0x03FF
#define TD_PORTLENMASK_PN	0xC000

#define TD_STATUS_OFFSET	0x07
#define TD_STATUSMASK_ACK	0x01
#define TD_STATUSMASK_ERR	0x02
#define TD_STATUSMASK_TMOUT	0x04
#define TD_STATUSMASK_SEQ	0x08
#define TD_STATUSMASK_SETUP	0x10
#define TD_STATUSMASK_OVF	0x20
#define TD_STATUSMASK_NAK	0x40
#define TD_STATUSMASK_STALL	0x80

#define TD_ERROR_MASK		(TD_STATUSMASK_ERR | TD_STATUSMASK_TMOUT | \
				 TD_STATUSMASK_STALL)

#define TD_RETRYCNT_OFFSET	0x08
#define TD_RETRYCNTMASK_ACT_FLG	0x10
#define TD_RETRYCNTMASK_TX_TYPE	0x0C
#define TD_RETRYCNTMASK_RTY_CNT	0x03

#define TD_RESIDUE_OVERFLOW	0x80

#define TD_PID_IN		0x90

/* Residue: signed 8bits, neg -> OVERFLOW, pos -> UNDERFLOW */
#define td_residue(td)		((__s8)(td->residue))
#define td_ly_base_addr(td)	(__le16_to_cpu((td)->ly_base_addr))
#define td_port_length(td)	(__le16_to_cpu((td)->port_length))
#define td_next_td_addr(td)	(__le16_to_cpu((td)->next_td_addr))

#define td_active(td)		((td)->retry_cnt & TD_RETRYCNTMASK_ACT_FLG)
#define td_length(td)		(td_port_length(td) & TD_PORTLENMASK_DL)

#define td_sequence_ok(td)	(!td->status || \
				 (!(td->status & TD_STATUSMASK_SEQ) ==	\
				  !(td->ctrl_reg & SEQ_SEL)))

#define td_acked(td)		(!td->status || \
				 (td->status & TD_STATUSMASK_ACK))
#define td_actual_bytes(td)	(td_length(td) - td_residue(td))

/* -------------------------------------------------------------------------- */

#ifdef DEBUG

/**
 * dbg_td - Dump the contents of the TD
 */
static void dbg_td(struct c67x00_hcd *c67x00, struct c67x00_td *td, char *msg)
{
	struct device *dev = c67x00_hcd_dev(c67x00);

	dev_dbg(dev, "### %s at 0x%04x\n", msg, td->td_addr);
	dev_dbg(dev, "urb:      0x%p\n", td->urb);
	dev_dbg(dev, "endpoint:   %4d\n", usb_pipeendpoint(td->pipe));
	dev_dbg(dev, "pipeout:    %4d\n", usb_pipeout(td->pipe));
	dev_dbg(dev, "ly_base_addr: 0x%04x\n", td_ly_base_addr(td));
	dev_dbg(dev, "port_length:  0x%04x\n", td_port_length(td));
	dev_dbg(dev, "pid_ep:         0x%02x\n", td->pid_ep);
	dev_dbg(dev, "dev_addr:       0x%02x\n", td->dev_addr);
	dev_dbg(dev, "ctrl_reg:       0x%02x\n", td->ctrl_reg);
	dev_dbg(dev, "status:         0x%02x\n", td->status);
	dev_dbg(dev, "retry_cnt:      0x%02x\n", td->retry_cnt);
	dev_dbg(dev, "residue:        0x%02x\n", td->residue);
	dev_dbg(dev, "next_td_addr: 0x%04x\n", td_next_td_addr(td));
	dev_dbg(dev, "data:");
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 1,
		       td->data, td_length(td), 1);
}
#else				/* DEBUG */

static inline void
dbg_td(struct c67x00_hcd *c67x00, struct c67x00_td *td, char *msg) { }

#endif				/* DEBUG */

/* -------------------------------------------------------------------------- */
/* Helper functions */

static inline u16 c67x00_get_current_frame_number(struct c67x00_hcd *c67x00)
{
	return c67x00_ll_husb_get_frame(c67x00->sie) & HOST_FRAME_MASK;
}

/**
 * frame_add
 * Software wraparound for framenumbers.
 */
static inline u16 frame_add(u16 a, u16 b)
{
	return (a + b) & HOST_FRAME_MASK;
}

/**
 * frame_after - is frame a after frame b
 */
static inline int frame_after(u16 a, u16 b)
{
	return ((HOST_FRAME_MASK + a - b) & HOST_FRAME_MASK) <
	    (HOST_FRAME_MASK / 2);
}

/**
 * frame_after_eq - is frame a after or equal to frame b
 */
static inline int frame_after_eq(u16 a, u16 b)
{
	return ((HOST_FRAME_MASK + 1 + a - b) & HOST_FRAME_MASK) <
	    (HOST_FRAME_MASK / 2);
}

/* -------------------------------------------------------------------------- */

/**
 * c67x00_release_urb - remove link from all tds to this urb
 * Disconnects the urb from it's tds, so that it can be given back.
 * pre: urb->hcpriv != NULL
 */
static void c67x00_release_urb(struct c67x00_hcd *c67x00, struct urb *urb)
{
	struct c67x00_td *td;
	struct c67x00_urb_priv *urbp;

	BUG_ON(!urb);

	c67x00->urb_count--;

	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
		c67x00->urb_iso_count--;
		if (c67x00->urb_iso_count == 0)
			c67x00->max_frame_bw = MAX_FRAME_BW_STD;
	}

	/* TODO this might be not so efficient when we've got many urbs!
	 * Alternatives:
	 *   * only clear when needed
	 *   * keep a list of tds with each urbp
	 */
	list_for_each_entry(td, &c67x00->td_list, td_list)
		if (urb == td->urb)
			td->urb = NULL;

	urbp = urb->hcpriv;
	urb->hcpriv = NULL;
	list_del(&urbp->hep_node);
	kfree(urbp);
}

/* -------------------------------------------------------------------------- */

static struct c67x00_ep_data *
c67x00_ep_data_alloc(struct c67x00_hcd *c67x00, struct urb *urb)
{
	struct usb_host_endpoint *hep = urb->ep;
	struct c67x00_ep_data *ep_data;
	int type;

	c67x00->current_frame = c67x00_get_current_frame_number(c67x00);

	/* Check if endpoint already has a c67x00_ep_data struct allocated */
	if (hep->hcpriv) {
		ep_data = hep->hcpriv;
		if (frame_after(c67x00->current_frame, ep_data->next_frame))
			ep_data->next_frame =
			    frame_add(c67x00->current_frame, 1);
		return hep->hcpriv;
	}

	/* Allocate and initialize a new c67x00 endpoint data structure */
	ep_data = kzalloc(sizeof(*ep_data), GFP_ATOMIC);
	if (!ep_data)
		return NULL;

	INIT_LIST_HEAD(&ep_data->queue);
	INIT_LIST_HEAD(&ep_data->node);
	ep_data->hep = hep;

	/* hold a reference to udev as long as this endpoint lives,
	 * this is needed to possibly fix the data toggle */
	ep_data->dev = usb_get_dev(urb->dev);
	hep->hcpriv = ep_data;

	/* For ISOC and INT endpoints, start ASAP: */
	ep_data->next_frame = frame_add(c67x00->current_frame, 1);

	/* Add the endpoint data to one of the pipe lists; must be added
	   in order of endpoint address */
	type = usb_pipetype(urb->pipe);
	if (list_empty(&ep_data->node)) {
		list_add(&ep_data->node, &c67x00->list[type]);
	} else {
		struct c67x00_ep_data *prev;

		list_for_each_entry(prev, &c67x00->list[type], node) {
			if (prev->hep->desc.bEndpointAddress >
			    hep->desc.bEndpointAddress) {
				list_add(&ep_data->node, prev->node.prev);
				break;
			}
		}
	}

	return ep_data;
}

static int c67x00_ep_data_free(struct usb_host_endpoint *hep)
{
	struct c67x00_ep_data *ep_data = hep->hcpriv;

	if (!ep_data)
		return 0;

	if (!list_empty(&ep_data->queue))
		return -EBUSY;

	usb_put_dev(ep_data->dev);
	list_del(&ep_data->queue);
	list_del(&ep_data->node);

	kfree(ep_data);
	hep->hcpriv = NULL;

	return 0;
}

void c67x00_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
{
	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
	unsigned long flags;

	if (!list_empty(&ep->urb_list))
		dev_warn(c67x00_hcd_dev(c67x00), "error: urb list not empty\n");

	spin_lock_irqsave(&c67x00->lock, flags);

	/* loop waiting for all transfers in the endpoint queue to complete */
	while (c67x00_ep_data_free(ep)) {
		/* Drop the lock so we can sleep waiting for the hardware */
		spin_unlock_irqrestore(&c67x00->lock, flags);

		/* it could happen that we reinitialize this completion, while
		 * somebody was waiting for that completion.  The timeout and
		 * while loop handle such cases, but this might be improved */
		INIT_COMPLETION(c67x00->endpoint_disable);
		c67x00_sched_kick(c67x00);
		wait_for_completion_timeout(&c67x00->endpoint_disable, 1 * HZ);

		spin_lock_irqsave(&c67x00->lock, flags);
	}

	spin_unlock_irqrestore(&c67x00->lock, flags);
}

/* -------------------------------------------------------------------------- */

static inline int get_root_port(struct usb_device *dev)
{
	while (dev->parent->parent)
		dev = dev->parent;
	return dev->portnum;
}

int c67x00_urb_enqueue(struct usb_hcd *hcd,
		       struct urb *urb, gfp_t mem_flags)
{
	int ret;
	unsigned long flags;
	struct c67x00_urb_priv *urbp;
	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
	int port = get_root_port(urb->dev)-1;

	spin_lock_irqsave(&c67x00->lock, flags);

	/* Make sure host controller is running */
	if (!HC_IS_RUNNING(hcd->state)) {
		ret = -ENODEV;
		goto err_not_linked;
	}

	ret = usb_hcd_link_urb_to_ep(hcd, urb);
	if (ret)
		goto err_not_linked;

	/* Allocate and initialize urb private data */
	urbp = kzalloc(sizeof(*urbp), mem_flags);
	if (!urbp) {
		ret = -ENOMEM;
		goto err_urbp;
	}

	INIT_LIST_HEAD(&urbp->hep_node);
	urbp->urb = urb;
	urbp->port = port;

	urbp->ep_data = c67x00_ep_data_alloc(c67x00, urb);

	if (!urbp->ep_data) {
		ret = -ENOMEM;
		goto err_epdata;
	}

	/* TODO claim bandwidth with usb_claim_bandwidth?
	 * also release it somewhere! */

	urb->hcpriv = urbp;

	urb->actual_length = 0;	/* Nothing received/transmitted yet */

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
		urb->interval = SETUP_STAGE;
		break;
	case PIPE_INTERRUPT:
		break;
	case PIPE_BULK:
		break;
	case PIPE_ISOCHRONOUS:
		if (c67x00->urb_iso_count == 0)
			c67x00->max_frame_bw = MAX_FRAME_BW_ISO;
		c67x00->urb_iso_count++;
		/* Assume always URB_ISO_ASAP, FIXME */
		if (list_empty(&urbp->ep_data->queue))
			urb->start_frame = urbp->ep_data->next_frame;
		else {
			/* Go right after the last one */
			struct urb *last_urb;

			last_urb = list_entry(urbp->ep_data->queue.prev,
					      struct c67x00_urb_priv,
					      hep_node)->urb;
			urb->start_frame =
			    frame_add(last_urb->start_frame,
				      last_urb->number_of_packets *
				      last_urb->interval);
		}
		urbp->cnt = 0;
		break;
	}

	/* Add the URB to the endpoint queue */
	list_add_tail(&urbp->hep_node, &urbp->ep_data->queue);

	/* If this is the only URB, kick start the controller */
	if (!c67x00->urb_count++)
		c67x00_ll_hpi_enable_sofeop(c67x00->sie);

	c67x00_sched_kick(c67x00);
	spin_unlock_irqrestore(&c67x00->lock, flags);

	return 0;

err_epdata:
	kfree(urbp);
err_urbp:
	usb_hcd_unlink_urb_from_ep(hcd, urb);
err_not_linked:
	spin_unlock_irqrestore(&c67x00->lock, flags);

	return ret;
}

int c67x00_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&c67x00->lock, flags);
	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
	if (rc)
		goto done;

	c67x00_release_urb(c67x00, urb);
	usb_hcd_unlink_urb_from_ep(hcd, urb);

	spin_unlock(&c67x00->lock);
	usb_hcd_giveback_urb(hcd, urb, status);
	spin_lock(&c67x00->lock);

	spin_unlock_irqrestore(&c67x00->lock, flags);

	return 0;

 done:
	spin_unlock_irqrestore(&c67x00->lock, flags);
	return rc;
}

/* -------------------------------------------------------------------------- */

/*
 * pre: c67x00 locked, urb unlocked
 */
static void
c67x00_giveback_urb(struct c67x00_hcd *c67x00, struct urb *urb, int status)
{
	struct c67x00_urb_priv *urbp;

	if (!urb)
		return;

	urbp = urb->hcpriv;
	urbp->status = status;

	list_del_init(&urbp->hep_node);

	c67x00_release_urb(c67x00, urb);
	usb_hcd_unlink_urb_from_ep(c67x00_hcd_to_hcd(c67x00), urb);
	spin_unlock(&c67x00->lock);
	usb_hcd_giveback_urb(c67x00_hcd_to_hcd(c67x00), urb, urbp->status);
	spin_lock(&c67x00->lock);
}

/* -------------------------------------------------------------------------- */

static int c67x00_claim_frame_bw(struct c67x00_hcd *c67x00, struct urb *urb,
				 int len, int periodic)
{
	struct c67x00_urb_priv *urbp = urb->hcpriv;
	int bit_time;

	/* According to the C67x00 BIOS user manual, page 3-18,19, the
	 * following calculations provide the full speed bit times for
	 * a transaction.
	 *
	 * FS(in)	= 112.5 +  9.36*BC + HOST_DELAY
	 * FS(in,iso)	=  90.5 +  9.36*BC + HOST_DELAY
	 * FS(out)	= 112.5 +  9.36*BC + HOST_DELAY
	 * FS(out,iso)	=  78.4 +  9.36*BC + HOST_DELAY
	 * LS(in)	= 802.4 + 75.78*BC + HOST_DELAY
	 * LS(out)	= 802.6 + 74.67*BC + HOST_DELAY
	 *
	 * HOST_DELAY == 106 for the c67200 and c67300.
	 */

	/* make calculations in 1/100 bit times to maintain resolution */
	if (urbp->ep_data->dev->speed == USB_SPEED_LOW) {
		/* Low speed pipe */
		if (usb_pipein(urb->pipe))
			bit_time = 80240 + 7578*len;
		else
			bit_time = 80260 + 7467*len;
	} else {
		/* FS pipes */
		if (usb_pipeisoc(urb->pipe))
			bit_time = usb_pipein(urb->pipe) ? 9050 : 7840;
		else
			bit_time = 11250;
		bit_time += 936*len;
	}

	/* Scale back down to integer bit times.  Use a host delay of 106.
	 * (this is the only place it is used) */
	bit_time = ((bit_time+50) / 100) + 106;

	if (unlikely(bit_time + c67x00->bandwidth_allocated >=
		     c67x00->max_frame_bw))
		return -EMSGSIZE;

	if (unlikely(c67x00->next_td_addr + CY_TD_SIZE >=
		     c67x00->td_base_addr + SIE_TD_SIZE))
		return -EMSGSIZE;

	if (unlikely(c67x00->next_buf_addr + len >=
		     c67x00->buf_base_addr + SIE_TD_BUF_SIZE))
		return -EMSGSIZE;

	if (periodic) {
		if (unlikely(bit_time + c67x00->periodic_bw_allocated >=
			     MAX_PERIODIC_BW(c67x00->max_frame_bw)))
			return -EMSGSIZE;
		c67x00->periodic_bw_allocated += bit_time;
	}

	c67x00->bandwidth_allocated += bit_time;
	return 0;
}

/* -------------------------------------------------------------------------- */

/**
 * td_addr and buf_addr must be word aligned
 */
static int c67x00_create_td(struct c67x00_hcd *c67x00, struct urb *urb,
			    void *data, int len, int pid, int toggle,
			    unsigned long privdata)
{
	struct c67x00_td *td;
	struct c67x00_urb_priv *urbp = urb->hcpriv;
	const __u8 active_flag = 1, retry_cnt = 3;
	__u8 cmd = 0;
	int tt = 0;

	if (c67x00_claim_frame_bw(c67x00, urb, len, usb_pipeisoc(urb->pipe)
				  || usb_pipeint(urb->pipe)))
		return -EMSGSIZE;	/* Not really an error, but expected */

	td = kzalloc(sizeof(*td), GFP_ATOMIC);
	if (!td)
		return -ENOMEM;

	td->pipe = urb->pipe;
	td->ep_data = urbp->ep_data;

	if ((td_udev(td)->speed == USB_SPEED_LOW) &&
	    !(c67x00->low_speed_ports & (1 << urbp->port)))
		cmd |= PREAMBLE_EN;

	switch (usb_pipetype(td->pipe)) {
	case PIPE_ISOCHRONOUS:
		tt = TT_ISOCHRONOUS;
		cmd |= ISO_EN;
		break;
	case PIPE_CONTROL:
		tt = TT_CONTROL;
		break;
	case PIPE_BULK:
		tt = TT_BULK;
		break;
	case PIPE_INTERRUPT:
		tt = TT_INTERRUPT;
		break;
	}

	if (toggle)
		cmd |= SEQ_SEL;

	cmd |= ARM_EN;

	/* SW part */
	td->td_addr = c67x00->next_td_addr;
	c67x00->next_td_addr = c67x00->next_td_addr + CY_TD_SIZE;

	/* HW part */
	td->ly_base_addr = __cpu_to_le16(c67x00->next_buf_addr);
	td->port_length = __cpu_to_le16((c67x00->sie->sie_num << 15) |
					(urbp->port << 14) | (len & 0x3FF));
	td->pid_ep = ((pid & 0xF) << TD_PIDEP_OFFSET) |
	    (usb_pipeendpoint(td->pipe) & 0xF);
	td->dev_addr = usb_pipedevice(td->pipe) & 0x7F;
	td->ctrl_reg = cmd;
	td->status = 0;
	td->retry_cnt = (tt << TT_OFFSET) | (active_flag << 4) | retry_cnt;
	td->residue = 0;
	td->next_td_addr = __cpu_to_le16(c67x00->next_td_addr);

	/* SW part */
	td->data = data;
	td->urb = urb;
	td->privdata = privdata;

	c67x00->next_buf_addr += (len + 1) & ~0x01;	/* properly align */

	list_add_tail(&td->td_list, &c67x00->td_list);
	return 0;
}

static inline void c67x00_release_td(struct c67x00_td *td)
{
	list_del_init(&td->td_list);
	kfree(td);
}

/* -------------------------------------------------------------------------- */

static int c67x00_add_data_urb(struct c67x00_hcd *c67x00, struct urb *urb)
{
	int remaining;
	int toggle;
	int pid;
	int ret = 0;
	int maxps;
	int need_empty;

	toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			       usb_pipeout(urb->pipe));
	remaining = urb->transfer_buffer_length - urb->actual_length;

	maxps = usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe));

	need_empty = (urb->transfer_flags & URB_ZERO_PACKET) &&
	    usb_pipeout(urb->pipe) && !(remaining % maxps);

	while (remaining || need_empty) {
		int len;
		char *td_buf;

		len = (remaining > maxps) ? maxps : remaining;
		if (!len)
			need_empty = 0;

		pid = usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;
		td_buf = urb->transfer_buffer + urb->transfer_buffer_length -
		    remaining;
		ret = c67x00_create_td(c67x00, urb, td_buf, len, pid, toggle,
				       DATA_STAGE);
		if (ret)
			return ret;	/* td wasn't created */

		toggle ^= 1;
		remaining -= len;
		if (usb_pipecontrol(urb->pipe))
			break;
	}

	return 0;
}

/**
 * return 0 in case more bandwidth is available, else errorcode
 */
static int c67x00_add_ctrl_urb(struct c67x00_hcd *c67x00, struct urb *urb)
{
	int ret;
	int pid;

	switch (urb->interval) {
	default:
	case SETUP_STAGE:
		ret = c67x00_create_td(c67x00, urb, urb->setup_packet,
				       8, USB_PID_SETUP, 0, SETUP_STAGE);
		if (ret)
			return ret;
		urb->interval = SETUP_STAGE;
		usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			      usb_pipeout(urb->pipe), 1);
		break;
	case DATA_STAGE:
		if (urb->transfer_buffer_length) {
			ret = c67x00_add_data_urb(c67x00, urb);
			if (ret)
				return ret;
			break;
		}		/* else fallthrough */
	case STATUS_STAGE:
		pid = !usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;
		ret = c67x00_create_td(c67x00, urb, NULL, 0, pid, 1,
				       STATUS_STAGE);
		if (ret)
			return ret;
		break;
	}

	return 0;
}

/*
 * return 0 in case more bandwidth is available, else errorcode
 */
static int c67x00_add_int_urb(struct c67x00_hcd *c67x00, struct urb *urb)
{
	struct c67x00_urb_priv *urbp = urb->hcpriv;

	if (frame_after_eq(c67x00->current_frame, urbp->ep_data->next_frame)) {
		urbp->ep_data->next_frame =
		    frame_add(urbp->ep_data->next_frame, urb->interval);
		return c67x00_add_data_urb(c67x00, urb);
	}
	return 0;
}

static int c67x00_add_iso_urb(struct c67x00_hcd *c67x00, struct urb *urb)
{
	struct c67x00_urb_priv *urbp = urb->hcpriv;

	if (frame_after_eq(c67x00->current_frame, urbp->ep_data->next_frame)) {
		char *td_buf;
		int len, pid, ret;

		BUG_ON(urbp->cnt >= urb->number_of_packets);

		td_buf = urb->transfer_buffer +
		    urb->iso_frame_desc[urbp->cnt].offset;
		len = urb->iso_frame_desc[urbp->cnt].length;
		pid = usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;

		ret = c67x00_create_td(c67x00, urb, td_buf, len, pid, 0,
				       urbp->cnt);
		if (ret) {
			printk(KERN_DEBUG "create failed: %d\n", ret);
			urb->iso_frame_desc[urbp->cnt].actual_length = 0;
			urb->iso_frame_desc[urbp->cnt].status = ret;
			if (urbp->cnt + 1 == urb->number_of_packets)
				c67x00_giveback_urb(c67x00, urb, 0);
		}

		urbp->ep_data->next_frame =
		    frame_add(urbp->ep_data->next_frame, urb->interval);
		urbp->cnt++;
	}
	return 0;
}

/* -------------------------------------------------------------------------- */

static void c67x00_fill_from_list(struct c67x00_hcd *c67x00, int type,
				  int (*add)(struct c67x00_hcd *, struct urb *))
{
	struct c67x00_ep_data *ep_data;
	struct urb *urb;

	/* traverse every endpoint on the list */
	list_for_each_entry(ep_data, &c67x00->list[type], node) {
		if (!list_empty(&ep_data->queue)) {
			/* and add the first urb */
			/* isochronous transfer rely on this */
			urb = list_entry(ep_data->queue.next,
					 struct c67x00_urb_priv,
					 hep_node)->urb;
			add(c67x00, urb);
		}
	}
}

static void c67x00_fill_frame(struct c67x00_hcd *c67x00)
{
	struct c67x00_td *td, *ttd;

	/* Check if we can proceed */
	if (!list_empty(&c67x00->td_list)) {
		dev_warn(c67x00_hcd_dev(c67x00),
			 "TD list not empty! This should not happen!\n");
		list_for_each_entry_safe(td, ttd, &c67x00->td_list, td_list) {
			dbg_td(c67x00, td, "Unprocessed td");
			c67x00_release_td(td);
		}
	}

	/* Reinitialize variables */
	c67x00->bandwidth_allocated = 0;
	c67x00->periodic_bw_allocated = 0;

	c67x00->next_td_addr = c67x00->td_base_addr;
	c67x00->next_buf_addr = c67x00->buf_base_addr;

	/* Fill the list */
	c67x00_fill_from_list(c67x00, PIPE_ISOCHRONOUS, c67x00_add_iso_urb);
	c67x00_fill_from_list(c67x00, PIPE_INTERRUPT, c67x00_add_int_urb);
	c67x00_fill_from_list(c67x00, PIPE_CONTROL, c67x00_add_ctrl_urb);
	c67x00_fill_from_list(c67x00, PIPE_BULK, c67x00_add_data_urb);
}

/* -------------------------------------------------------------------------- */

/**
 * Get TD from C67X00
 */
static inline void
c67x00_parse_td(struct c67x00_hcd *c67x00, struct c67x00_td *td)
{
	c67x00_ll_read_mem_le16(c67x00->sie->dev,
				td->td_addr, td, CY_TD_SIZE);

	if (usb_pipein(td->pipe) && td_actual_bytes(td))
		c67x00_ll_read_mem_le16(c67x00->sie->dev, td_ly_base_addr(td),
					td->data, td_actual_bytes(td));
}

static int c67x00_td_to_error(struct c67x00_hcd *c67x00, struct c67x00_td *td)
{
	if (td->status & TD_STATUSMASK_ERR) {
		dbg_td(c67x00, td, "ERROR_FLAG");
		return -EILSEQ;
	}
	if (td->status & TD_STATUSMASK_STALL) {
		/* dbg_td(c67x00, td, "STALL"); */
		return -EPIPE;
	}
	if (td->status & TD_STATUSMASK_TMOUT) {
		dbg_td(c67x00, td, "TIMEOUT");
		return -ETIMEDOUT;
	}

	return 0;
}

static inline int c67x00_end_of_data(struct c67x00_td *td)
{
	int maxps, need_empty, remaining;
	struct urb *urb = td->urb;
	int act_bytes;

	act_bytes = td_actual_bytes(td);

	if (unlikely(!act_bytes))
		return 1;	/* This was an empty packet */

	maxps = usb_maxpacket(td_udev(td), td->pipe, usb_pipeout(td->pipe));

	if (unlikely(act_bytes < maxps))
		return 1;	/* Smaller then full packet */

	remaining = urb->transfer_buffer_length - urb->actual_length;
	need_empty = (urb->transfer_flags & URB_ZERO_PACKET) &&
	    usb_pipeout(urb->pipe) && !(remaining % maxps);

	if (unlikely(!remaining && !need_empty))
		return 1;

	return 0;
}

/* -------------------------------------------------------------------------- */

/* Remove all td's from the list which come
 * after last_td and are meant for the same pipe.
 * This is used when a short packet has occurred */
static inline void c67x00_clear_pipe(struct c67x00_hcd *c67x00,
				     struct c67x00_td *last_td)
{
	struct c67x00_td *td, *tmp;
	td = last_td;
	tmp = last_td;
	while (td->td_list.next != &c67x00->td_list) {
		td = list_entry(td->td_list.next, struct c67x00_td, td_list);
		if (td->pipe == last_td->pipe) {
			c67x00_release_td(td);
			td = tmp;
		}
		tmp = td;
	}
}

/* -------------------------------------------------------------------------- */

static void c67x00_handle_successful_td(struct c67x00_hcd *c67x00,
					struct c67x00_td *td)
{
	struct urb *urb = td->urb;

	if (!urb)
		return;

	urb->actual_length += td_actual_bytes(td);

	switch (usb_pipetype(td->pipe)) {
		/* isochronous tds are handled separately */
	case PIPE_CONTROL:
		switch (td->privdata) {
		case SETUP_STAGE:
			urb->interval =
			    urb->transfer_buffer_length ?
			    DATA_STAGE : STATUS_STAGE;
			/* Don't count setup_packet with normal data: */
			urb->actual_length = 0;
			break;

		case DATA_STAGE:
			if (c67x00_end_of_data(td)) {
				urb->interval = STATUS_STAGE;
				c67x00_clear_pipe(c67x00, td);
			}
			break;

		case STATUS_STAGE:
			urb->interval = 0;
			c67x00_giveback_urb(c67x00, urb, 0);
			break;
		}
		break;

	case PIPE_INTERRUPT:
	case PIPE_BULK:
		if (unlikely(c67x00_end_of_data(td))) {
			c67x00_clear_pipe(c67x00, td);
			c67x00_giveback_urb(c67x00, urb, 0);
		}
		break;
	}
}

static void c67x00_handle_isoc(struct c67x00_hcd *c67x00, struct c67x00_td *td)
{
	struct urb *urb = td->urb;
	struct c67x00_urb_priv *urbp;
	int cnt;

	if (!urb)
		return;

	urbp = urb->hcpriv;
	cnt = td->privdata;

	if (td->status & TD_ERROR_MASK)
		urb->error_count++;

	urb->iso_frame_desc[cnt].actual_length = td_actual_bytes(td);
	urb->iso_frame_desc[cnt].status = c67x00_td_to_error(c67x00, td);
	if (cnt + 1 == urb->number_of_packets)	/* Last packet */
		c67x00_giveback_urb(c67x00, urb, 0);
}

/* -------------------------------------------------------------------------- */

/**
 * c67x00_check_td_list - handle tds which have been processed by the c67x00
 * pre: current_td == 0
 */
static inline void c67x00_check_td_list(struct c67x00_hcd *c67x00)
{
	struct c67x00_td *td, *tmp;
	struct urb *urb;
	int ack_ok;
	int clear_endpoint;

	list_for_each_entry_safe(td, tmp, &c67x00->td_list, td_list) {
		/* get the TD */
		c67x00_parse_td(c67x00, td);
		urb = td->urb;	/* urb can be NULL! */
		ack_ok = 0;
		clear_endpoint = 1;

		/* Handle isochronous transfers separately */
		if (usb_pipeisoc(td->pipe)) {
			clear_endpoint = 0;
			c67x00_handle_isoc(c67x00, td);
			goto cont;
		}

		/* When an error occurs, all td's for that pipe go into an
		 * inactive state. This state matches successful transfers so
		 * we must make sure not to service them. */
		if (td->status & TD_ERROR_MASK) {
			c67x00_giveback_urb(c67x00, urb,
					    c67x00_td_to_error(c67x00, td));
			goto cont;
		}

		if ((td->status & TD_STATUSMASK_NAK) || !td_sequence_ok(td) ||
		    !td_acked(td))
			goto cont;

		/* Sequence ok and acked, don't need to fix toggle */
		ack_ok = 1;

		if (unlikely(td->status & TD_STATUSMASK_OVF)) {
			if (td_residue(td) & TD_RESIDUE_OVERFLOW) {
				/* Overflow */
				c67x00_giveback_urb(c67x00, urb, -EOVERFLOW);
				goto cont;
			}
		}

		clear_endpoint = 0;
		c67x00_handle_successful_td(c67x00, td);

cont:
		if (clear_endpoint)
			c67x00_clear_pipe(c67x00, td);
		if (ack_ok)
			usb_settoggle(td_udev(td), usb_pipeendpoint(td->pipe),
				      usb_pipeout(td->pipe),
				      !(td->ctrl_reg & SEQ_SEL));
		/* next in list could have been removed, due to clear_pipe! */
		tmp = list_entry(td->td_list.next, typeof(*td), td_list);
		c67x00_release_td(td);
	}
}

/* -------------------------------------------------------------------------- */

static inline int c67x00_all_tds_processed(struct c67x00_hcd *c67x00)
{
	/* If all tds are processed, we can check the previous frame (if
	 * there was any) and start our next frame.
	 */
	return !c67x00_ll_husb_get_current_td(c67x00->sie);
}

/**
 * Send td to C67X00
 */
static void c67x00_send_td(struct c67x00_hcd *c67x00, struct c67x00_td *td)
{
	int len = td_length(td);

	if (len && ((td->pid_ep & TD_PIDEPMASK_PID) != TD_PID_IN))
		c67x00_ll_write_mem_le16(c67x00->sie->dev, td_ly_base_addr(td),
					 td->data, len);

	c67x00_ll_write_mem_le16(c67x00->sie->dev,
				 td->td_addr, td, CY_TD_SIZE);
}

static void c67x00_send_frame(struct c67x00_hcd *c67x00)
{
	struct c67x00_td *td;

	if (list_empty(&c67x00->td_list))
		dev_warn(c67x00_hcd_dev(c67x00),
			 "%s: td list should not be empty here!\n",
			 __func__);

	list_for_each_entry(td, &c67x00->td_list, td_list) {
		if (td->td_list.next == &c67x00->td_list)
			td->next_td_addr = 0;	/* Last td in list */

		c67x00_send_td(c67x00, td);
	}

	c67x00_ll_husb_set_current_td(c67x00->sie, c67x00->td_base_addr);
}

/* -------------------------------------------------------------------------- */

/**
 * c67x00_do_work - Schedulers state machine
 */
static void c67x00_do_work(struct c67x00_hcd *c67x00)
{
	spin_lock(&c67x00->lock);
	/* Make sure all tds are processed */
	if (!c67x00_all_tds_processed(c67x00))
		goto out;

	c67x00_check_td_list(c67x00);

	/* no td's are being processed (current == 0)
	 * and all have been "checked" */
	complete(&c67x00->endpoint_disable);

	if (!list_empty(&c67x00->td_list))
		goto out;

	c67x00->current_frame = c67x00_get_current_frame_number(c67x00);
	if (c67x00->current_frame == c67x00->last_frame)
		goto out;	/* Don't send tds in same frame */
	c67x00->last_frame = c67x00->current_frame;

	/* If no urbs are scheduled, our work is done */
	if (!c67x00->urb_count) {
		c67x00_ll_hpi_disable_sofeop(c67x00->sie);
		goto out;
	}

	c67x00_fill_frame(c67x00);
	if (!list_empty(&c67x00->td_list))
		/* TD's have been added to the frame */
		c67x00_send_frame(c67x00);

 out:
	spin_unlock(&c67x00->lock);
}

/* -------------------------------------------------------------------------- */

static void c67x00_sched_tasklet(unsigned long __c67x00)
{
	struct c67x00_hcd *c67x00 = (struct c67x00_hcd *)__c67x00;
	c67x00_do_work(c67x00);
}

void c67x00_sched_kick(struct c67x00_hcd *c67x00)
{
	tasklet_hi_schedule(&c67x00->tasklet);
}

int c67x00_sched_start_scheduler(struct c67x00_hcd *c67x00)
{
	tasklet_init(&c67x00->tasklet, c67x00_sched_tasklet,
		     (unsigned long)c67x00);
	return 0;
}

void c67x00_sched_stop_scheduler(struct c67x00_hcd *c67x00)
{
	tasklet_kill(&c67x00->tasklet);
}