summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/udc/aspeed-vhub/epn.c
blob: 80c9feac5147b5450cf0be37ce6ed29c8b44f0bb (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
 *
 * epn.c - Generic endpoints management
 *
 * Copyright 2017 IBM Corporation
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/prefetch.h>
#include <linux/clk.h>
#include <linux/usb/gadget.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/regmap.h>
#include <linux/dma-mapping.h>

#include "vhub.h"

#define EXTRA_CHECKS

#ifdef EXTRA_CHECKS
#define CHECK(ep, expr, fmt...)					\
	do {							\
		if (!(expr)) EPDBG(ep, "CHECK:" fmt);		\
	} while(0)
#else
#define CHECK(ep, expr, fmt...)	do { } while(0)
#endif

static void ast_vhub_epn_kick(struct ast_vhub_ep *ep, struct ast_vhub_req *req)
{
	unsigned int act = req->req.actual;
	unsigned int len = req->req.length;
	unsigned int chunk;

	/* There should be no DMA ongoing */
	WARN_ON(req->active);

	/* Calculate next chunk size */
	chunk = len - act;
	if (chunk > ep->ep.maxpacket)
		chunk = ep->ep.maxpacket;
	else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
		req->last_desc = 1;

	EPVDBG(ep, "kick req %p act=%d/%d chunk=%d last=%d\n",
	       req, act, len, chunk, req->last_desc);

	/* If DMA unavailable, using staging EP buffer */
	if (!req->req.dma) {

		/* For IN transfers, copy data over first */
		if (ep->epn.is_in)
			memcpy(ep->buf, req->req.buf + act, chunk);
		writel(ep->buf_dma, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
	} else
		writel(req->req.dma + act, ep->epn.regs + AST_VHUB_EP_DESC_BASE);

	/* Start DMA */
	req->active = true;
	writel(VHUB_EP_DMA_SET_TX_SIZE(chunk),
	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
	writel(VHUB_EP_DMA_SET_TX_SIZE(chunk) | VHUB_EP_DMA_SINGLE_KICK,
	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
}

static void ast_vhub_epn_handle_ack(struct ast_vhub_ep *ep)
{
	struct ast_vhub_req *req;
	unsigned int len;
	u32 stat;

	/* Read EP status */
	stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);

	/* Grab current request if any */
	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);

	EPVDBG(ep, "ACK status=%08x is_in=%d, req=%p (active=%d)\n",
	       stat, ep->epn.is_in, req, req ? req->active : 0);

	/* In absence of a request, bail out, must have been dequeued */
	if (!req)
		return;

	/*
	 * Request not active, move on to processing queue, active request
	 * was probably dequeued
	 */
	if (!req->active)
		goto next_chunk;

	/* Check if HW has moved on */
	if (VHUB_EP_DMA_RPTR(stat) != 0) {
		EPDBG(ep, "DMA read pointer not 0 !\n");
		return;
	}

	/* No current DMA ongoing */
	req->active = false;

	/* Grab lenght out of HW */
	len = VHUB_EP_DMA_TX_SIZE(stat);

	/* If not using DMA, copy data out if needed */
	if (!req->req.dma && !ep->epn.is_in && len)
		memcpy(req->req.buf + req->req.actual, ep->buf, len);

	/* Adjust size */
	req->req.actual += len;

	/* Check for short packet */
	if (len < ep->ep.maxpacket)
		req->last_desc = 1;

	/* That's it ? complete the request and pick a new one */
	if (req->last_desc >= 0) {
		ast_vhub_done(ep, req, 0);
		req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req,
					       queue);

		/*
		 * Due to lock dropping inside "done" the next request could
		 * already be active, so check for that and bail if needed.
		 */
		if (!req || req->active)
			return;
	}

 next_chunk:
	ast_vhub_epn_kick(ep, req);
}

static inline unsigned int ast_vhub_count_free_descs(struct ast_vhub_ep *ep)
{
	/*
	 * d_next == d_last means descriptor list empty to HW,
	 * thus we can only have AST_VHUB_DESCS_COUNT-1 descriptors
	 * in the list
	 */
	return (ep->epn.d_last + AST_VHUB_DESCS_COUNT - ep->epn.d_next - 1) &
		(AST_VHUB_DESCS_COUNT - 1);
}

static void ast_vhub_epn_kick_desc(struct ast_vhub_ep *ep,
				   struct ast_vhub_req *req)
{
	unsigned int act = req->act_count;
	unsigned int len = req->req.length;
	unsigned int chunk;

	/* Mark request active if not already */
	req->active = true;

	/* If the request was already completely written, do nothing */
	if (req->last_desc >= 0)
		return;

	EPVDBG(ep, "kick act=%d/%d chunk_max=%d free_descs=%d\n",
	       act, len, ep->epn.chunk_max, ast_vhub_count_free_descs(ep));

	/* While we can create descriptors */
	while (ast_vhub_count_free_descs(ep) && req->last_desc < 0) {
		struct ast_vhub_desc *desc;
		unsigned int d_num;

		/* Grab next free descriptor */
		d_num = ep->epn.d_next;
		desc = &ep->epn.descs[d_num];
		ep->epn.d_next = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);

		/* Calculate next chunk size */
		chunk = len - act;
		if (chunk <= ep->epn.chunk_max) {
			/*
			 * Is this the last packet ? Because of having up to 8
			 * packets in a descriptor we can't just compare "chunk"
			 * with ep.maxpacket. We have to see if it's a multiple
			 * of it to know if we have to send a zero packet.
			 * Sadly that involves a modulo which is a bit expensive
			 * but probably still better than not doing it.
			 */
			if (!chunk || !req->req.zero || (chunk % ep->ep.maxpacket) != 0)
				req->last_desc = d_num;
		} else {
			chunk = ep->epn.chunk_max;
		}

		EPVDBG(ep, " chunk: act=%d/%d chunk=%d last=%d desc=%d free=%d\n",
		       act, len, chunk, req->last_desc, d_num,
		       ast_vhub_count_free_descs(ep));

		/* Populate descriptor */
		desc->w0 = cpu_to_le32(req->req.dma + act);

		/* Interrupt if end of request or no more descriptors */

		/*
		 * TODO: Be smarter about it, if we don't have enough
		 * descriptors request an interrupt before queue empty
		 * or so in order to be able to populate more before
		 * the HW runs out. This isn't a problem at the moment
		 * as we use 256 descriptors and only put at most one
		 * request in the ring.
		 */
		desc->w1 = cpu_to_le32(VHUB_DSC1_IN_SET_LEN(chunk));
		if (req->last_desc >= 0 || !ast_vhub_count_free_descs(ep))
			desc->w1 |= cpu_to_le32(VHUB_DSC1_IN_INTERRUPT);

		/* Account packet */
		req->act_count = act = act + chunk;
	}

	/* Tell HW about new descriptors */
	writel(VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next),
	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);

	EPVDBG(ep, "HW kicked, d_next=%d dstat=%08x\n",
	       ep->epn.d_next, readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS));
}

static void ast_vhub_epn_handle_ack_desc(struct ast_vhub_ep *ep)
{
	struct ast_vhub_req *req;
	unsigned int len, d_last;
	u32 stat, stat1;

	/* Read EP status, workaround HW race */
	do {
		stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
		stat1 = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
	} while(stat != stat1);

	/* Extract RPTR */
	d_last = VHUB_EP_DMA_RPTR(stat);

	/* Grab current request if any */
	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);

	EPVDBG(ep, "ACK status=%08x is_in=%d ep->d_last=%d..%d\n",
	       stat, ep->epn.is_in, ep->epn.d_last, d_last);

	/* Check all completed descriptors */
	while (ep->epn.d_last != d_last) {
		struct ast_vhub_desc *desc;
		unsigned int d_num;
		bool is_last_desc;

		/* Grab next completed descriptor */
		d_num = ep->epn.d_last;
		desc = &ep->epn.descs[d_num];
		ep->epn.d_last = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);

		/* Grab len out of descriptor */
		len = VHUB_DSC1_IN_LEN(le32_to_cpu(desc->w1));

		EPVDBG(ep, " desc %d len=%d req=%p (act=%d)\n",
		       d_num, len, req, req ? req->active : 0);

		/* If no active request pending, move on */
		if (!req || !req->active)
			continue;

		/* Adjust size */
		req->req.actual += len;

		/* Is that the last chunk ? */
		is_last_desc = req->last_desc == d_num;
		CHECK(ep, is_last_desc == (len < ep->ep.maxpacket ||
					   (req->req.actual >= req->req.length &&
					    !req->req.zero)),
		      "Last packet discrepancy: last_desc=%d len=%d r.act=%d "
		      "r.len=%d r.zero=%d mp=%d\n",
		      is_last_desc, len, req->req.actual, req->req.length,
		      req->req.zero, ep->ep.maxpacket);

		if (is_last_desc) {
			/*
			 * Because we can only have one request at a time
			 * in our descriptor list in this implementation,
			 * d_last and ep->d_last should now be equal
			 */
			CHECK(ep, d_last == ep->epn.d_last,
			      "DMA read ptr mismatch %d vs %d\n",
			      d_last, ep->epn.d_last);

			/* Note: done will drop and re-acquire the lock */
			ast_vhub_done(ep, req, 0);
			req = list_first_entry_or_null(&ep->queue,
						       struct ast_vhub_req,
						       queue);
			break;
		}
	}

	/* More work ? */
	if (req)
		ast_vhub_epn_kick_desc(ep, req);
}

void ast_vhub_epn_ack_irq(struct ast_vhub_ep *ep)
{
	if (ep->epn.desc_mode)
		ast_vhub_epn_handle_ack_desc(ep);
	else
		ast_vhub_epn_handle_ack(ep);
}

static int ast_vhub_epn_queue(struct usb_ep* u_ep, struct usb_request *u_req,
			      gfp_t gfp_flags)
{
	struct ast_vhub_req *req = to_ast_req(u_req);
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
	struct ast_vhub *vhub = ep->vhub;
	unsigned long flags;
	bool empty;
	int rc;

	/* Paranoid checks */
	if (!u_req || !u_req->complete || !u_req->buf) {
		dev_warn(&vhub->pdev->dev, "Bogus EPn request ! u_req=%p\n", u_req);
		if (u_req) {
			dev_warn(&vhub->pdev->dev, "complete=%p internal=%d\n",
				 u_req->complete, req->internal);
		}
		return -EINVAL;
	}

	/* Endpoint enabled ? */
	if (!ep->epn.enabled || !u_ep->desc || !ep->dev || !ep->d_idx ||
	    !ep->dev->enabled || ep->dev->suspended) {
		EPDBG(ep,"Enqueing request on wrong or disabled EP\n");
		return -ESHUTDOWN;
	}

	/* Map request for DMA if possible. For now, the rule for DMA is
	 * that:
	 *
	 *  * For single stage mode (no descriptors):
	 *
	 *   - The buffer is aligned to a 8 bytes boundary (HW requirement)
	 *   - For a OUT endpoint, the request size is a multiple of the EP
	 *     packet size (otherwise the controller will DMA past the end
	 *     of the buffer if the host is sending a too long packet).
	 *
	 *  * For descriptor mode (tx only for now), always.
	 *
	 * We could relax the latter by making the decision to use the bounce
	 * buffer based on the size of a given *segment* of the request rather
	 * than the whole request.
	 */
	if (ep->epn.desc_mode ||
	    ((((unsigned long)u_req->buf & 7) == 0) &&
	     (ep->epn.is_in || !(u_req->length & (u_ep->maxpacket - 1))))) {
		rc = usb_gadget_map_request(&ep->dev->gadget, u_req,
					    ep->epn.is_in);
		if (rc) {
			dev_warn(&vhub->pdev->dev,
				 "Request mapping failure %d\n", rc);
			return rc;
		}
	} else
		u_req->dma = 0;

	EPVDBG(ep, "enqueue req @%p\n", req);
	EPVDBG(ep, " l=%d dma=0x%x zero=%d noshort=%d noirq=%d is_in=%d\n",
	       u_req->length, (u32)u_req->dma, u_req->zero,
	       u_req->short_not_ok, u_req->no_interrupt,
	       ep->epn.is_in);

	/* Initialize request progress fields */
	u_req->status = -EINPROGRESS;
	u_req->actual = 0;
	req->act_count = 0;
	req->active = false;
	req->last_desc = -1;
	spin_lock_irqsave(&vhub->lock, flags);
	empty = list_empty(&ep->queue);

	/* Add request to list and kick processing if empty */
	list_add_tail(&req->queue, &ep->queue);
	if (empty) {
		if (ep->epn.desc_mode)
			ast_vhub_epn_kick_desc(ep, req);
		else
			ast_vhub_epn_kick(ep, req);
	}
	spin_unlock_irqrestore(&vhub->lock, flags);

	return 0;
}

static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,
				     bool restart_ep)
{
	u32 state, reg, loops;

	/* Stop DMA activity */
	writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);

	/* Wait for it to complete */
	for (loops = 0; loops < 1000; loops++) {
		state = readl(ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
		state = VHUB_EP_DMA_PROC_STATUS(state);
		if (state == EP_DMA_PROC_RX_IDLE ||
		    state == EP_DMA_PROC_TX_IDLE)
			break;
		udelay(1);
	}
	if (loops >= 1000)
		dev_warn(&ep->vhub->pdev->dev, "Timeout waiting for DMA\n");

	/* If we don't have to restart the endpoint, that's it */
	if (!restart_ep)
		return;

	/* Restart the endpoint */
	if (ep->epn.desc_mode) {
		/*
		 * Take out descriptors by resetting the DMA read
		 * pointer to be equal to the CPU write pointer.
		 *
		 * Note: If we ever support creating descriptors for
		 * requests that aren't the head of the queue, we
		 * may have to do something more complex here,
		 * especially if the request being taken out is
		 * not the current head descriptors.
		 */
		reg = VHUB_EP_DMA_SET_RPTR(ep->epn.d_next) |
			VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next);
		writel(reg, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);

		/* Then turn it back on */
		writel(ep->epn.dma_conf,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
	} else {
		/* Single mode: just turn it back on */
		writel(ep->epn.dma_conf,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
	}
}

static int ast_vhub_epn_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
{
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
	struct ast_vhub *vhub = ep->vhub;
	struct ast_vhub_req *req;
	unsigned long flags;
	int rc = -EINVAL;

	spin_lock_irqsave(&vhub->lock, flags);

	/* Make sure it's actually queued on this endpoint */
	list_for_each_entry (req, &ep->queue, queue) {
		if (&req->req == u_req)
			break;
	}

	if (&req->req == u_req) {
		EPVDBG(ep, "dequeue req @%p active=%d\n",
		       req, req->active);
		if (req->active)
			ast_vhub_stop_active_req(ep, true);
		ast_vhub_done(ep, req, -ECONNRESET);
		rc = 0;
	}

	spin_unlock_irqrestore(&vhub->lock, flags);
	return rc;
}

void ast_vhub_update_epn_stall(struct ast_vhub_ep *ep)
{
	u32 reg;

	if (WARN_ON(ep->d_idx == 0))
		return;
	reg = readl(ep->epn.regs + AST_VHUB_EP_CONFIG);
	if (ep->epn.stalled || ep->epn.wedged)
		reg |= VHUB_EP_CFG_STALL_CTRL;
	else
		reg &= ~VHUB_EP_CFG_STALL_CTRL;
	writel(reg, ep->epn.regs + AST_VHUB_EP_CONFIG);

	if (!ep->epn.stalled && !ep->epn.wedged)
		writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
		       ep->vhub->regs + AST_VHUB_EP_TOGGLE);
}

static int ast_vhub_set_halt_and_wedge(struct usb_ep* u_ep, bool halt,
				      bool wedge)
{
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
	struct ast_vhub *vhub = ep->vhub;
	unsigned long flags;

	EPDBG(ep, "Set halt (%d) & wedge (%d)\n", halt, wedge);

	if (!u_ep || !u_ep->desc)
		return -EINVAL;
	if (ep->d_idx == 0)
		return 0;
	if (ep->epn.is_iso)
		return -EOPNOTSUPP;

	spin_lock_irqsave(&vhub->lock, flags);

	/* Fail with still-busy IN endpoints */
	if (halt && ep->epn.is_in && !list_empty(&ep->queue)) {
		spin_unlock_irqrestore(&vhub->lock, flags);
		return -EAGAIN;
	}
	ep->epn.stalled = halt;
	ep->epn.wedged = wedge;
	ast_vhub_update_epn_stall(ep);

	spin_unlock_irqrestore(&vhub->lock, flags);

	return 0;
}

static int ast_vhub_epn_set_halt(struct usb_ep *u_ep, int value)
{
	return ast_vhub_set_halt_and_wedge(u_ep, value != 0, false);
}

static int ast_vhub_epn_set_wedge(struct usb_ep *u_ep)
{
	return ast_vhub_set_halt_and_wedge(u_ep, true, true);
}

static int ast_vhub_epn_disable(struct usb_ep* u_ep)
{
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
	struct ast_vhub *vhub = ep->vhub;
	unsigned long flags;
	u32 imask, ep_ier;

	EPDBG(ep, "Disabling !\n");

	spin_lock_irqsave(&vhub->lock, flags);

	ep->epn.enabled = false;

	/* Stop active DMA if any */
	ast_vhub_stop_active_req(ep, false);

	/* Disable endpoint */
	writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);

	/* Disable ACK interrupt */
	imask = VHUB_EP_IRQ(ep->epn.g_idx);
	ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
	ep_ier &= ~imask;
	writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
	writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);

	/* Nuke all pending requests */
	ast_vhub_nuke(ep, -ESHUTDOWN);

	/* No more descriptor associated with request */
	ep->ep.desc = NULL;

	spin_unlock_irqrestore(&vhub->lock, flags);

	return 0;
}

static int ast_vhub_epn_enable(struct usb_ep* u_ep,
			       const struct usb_endpoint_descriptor *desc)
{
	static const char *ep_type_string[] __maybe_unused = { "ctrl",
							       "isoc",
							       "bulk",
							       "intr" };
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
	struct ast_vhub_dev *dev;
	struct ast_vhub *vhub;
	u16 maxpacket, type;
	unsigned long flags;
	u32 ep_conf, ep_ier, imask;

	/* Check arguments */
	if (!u_ep || !desc)
		return -EINVAL;

	maxpacket = usb_endpoint_maxp(desc);
	if (!ep->d_idx || !ep->dev ||
	    desc->bDescriptorType != USB_DT_ENDPOINT ||
	    maxpacket == 0 || maxpacket > ep->ep.maxpacket) {
		EPDBG(ep, "Invalid EP enable,d_idx=%d,dev=%p,type=%d,mp=%d/%d\n",
		      ep->d_idx, ep->dev, desc->bDescriptorType,
		      maxpacket, ep->ep.maxpacket);
		return -EINVAL;
	}
	if (ep->d_idx != usb_endpoint_num(desc)) {
		EPDBG(ep, "EP number mismatch !\n");
		return -EINVAL;
	}

	if (ep->epn.enabled) {
		EPDBG(ep, "Already enabled\n");
		return -EBUSY;
	}
	dev = ep->dev;
	vhub = ep->vhub;

	/* Check device state */
	if (!dev->driver) {
		EPDBG(ep, "Bogus device state: driver=%p speed=%d\n",
		       dev->driver, dev->gadget.speed);
		return -ESHUTDOWN;
	}

	/* Grab some info from the descriptor */
	ep->epn.is_in = usb_endpoint_dir_in(desc);
	ep->ep.maxpacket = maxpacket;
	type = usb_endpoint_type(desc);
	ep->epn.d_next = ep->epn.d_last = 0;
	ep->epn.is_iso = false;
	ep->epn.stalled = false;
	ep->epn.wedged = false;

	EPDBG(ep, "Enabling [%s] %s num %d maxpacket=%d\n",
	      ep->epn.is_in ? "in" : "out", ep_type_string[type],
	      usb_endpoint_num(desc), maxpacket);

	/* Can we use DMA descriptor mode ? */
	ep->epn.desc_mode = ep->epn.descs && ep->epn.is_in;
	if (ep->epn.desc_mode)
		memset(ep->epn.descs, 0, 8 * AST_VHUB_DESCS_COUNT);

	/*
	 * Large send function can send up to 8 packets from
	 * one descriptor with a limit of 4095 bytes.
	 */
	ep->epn.chunk_max = ep->ep.maxpacket;
	if (ep->epn.is_in) {
		ep->epn.chunk_max <<= 3;
		while (ep->epn.chunk_max > 4095)
			ep->epn.chunk_max -= ep->ep.maxpacket;
	}

	switch(type) {
	case USB_ENDPOINT_XFER_CONTROL:
		EPDBG(ep, "Only one control endpoint\n");
		return -EINVAL;
	case USB_ENDPOINT_XFER_INT:
		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_INT);
		break;
	case USB_ENDPOINT_XFER_BULK:
		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_BULK);
		break;
	case USB_ENDPOINT_XFER_ISOC:
		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_ISO);
		ep->epn.is_iso = true;
		break;
	default:
		return -EINVAL;
	}

	/* Encode the rest of the EP config register */
	if (maxpacket < 1024)
		ep_conf |= VHUB_EP_CFG_SET_MAX_PKT(maxpacket);
	if (!ep->epn.is_in)
		ep_conf |= VHUB_EP_CFG_DIR_OUT;
	ep_conf |= VHUB_EP_CFG_SET_EP_NUM(usb_endpoint_num(desc));
	ep_conf |= VHUB_EP_CFG_ENABLE;
	ep_conf |= VHUB_EP_CFG_SET_DEV(dev->index + 1);
	EPVDBG(ep, "config=%08x\n", ep_conf);

	spin_lock_irqsave(&vhub->lock, flags);

	/* Disable HW and reset DMA */
	writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
	writel(VHUB_EP_DMA_CTRL_RESET,
	       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);

	/* Configure and enable */
	writel(ep_conf, ep->epn.regs + AST_VHUB_EP_CONFIG);

	if (ep->epn.desc_mode) {
		/* Clear DMA status, including the DMA read ptr */
		writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);

		/* Set descriptor base */
		writel(ep->epn.descs_dma,
		       ep->epn.regs + AST_VHUB_EP_DESC_BASE);

		/* Set base DMA config value */
		ep->epn.dma_conf = VHUB_EP_DMA_DESC_MODE;
		if (ep->epn.is_in)
			ep->epn.dma_conf |= VHUB_EP_DMA_IN_LONG_MODE;

		/* First reset and disable all operations */
		writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);

		/* Enable descriptor mode */
		writel(ep->epn.dma_conf,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
	} else {
		/* Set base DMA config value */
		ep->epn.dma_conf = VHUB_EP_DMA_SINGLE_STAGE;

		/* Reset and switch to single stage mode */
		writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
		writel(ep->epn.dma_conf,
		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
		writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
	}

	/* Cleanup data toggle just in case */
	writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
	       vhub->regs + AST_VHUB_EP_TOGGLE);

	/* Cleanup and enable ACK interrupt */
	imask = VHUB_EP_IRQ(ep->epn.g_idx);
	writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
	ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
	ep_ier |= imask;
	writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);

	/* Woot, we are online ! */
	ep->epn.enabled = true;

	spin_unlock_irqrestore(&vhub->lock, flags);

	return 0;
}

static void ast_vhub_epn_dispose(struct usb_ep *u_ep)
{
	struct ast_vhub_ep *ep = to_ast_ep(u_ep);

	if (WARN_ON(!ep->dev || !ep->d_idx))
		return;

	EPDBG(ep, "Releasing endpoint\n");

	/* Take it out of the EP list */
	list_del_init(&ep->ep.ep_list);

	/* Mark the address free in the device */
	ep->dev->epns[ep->d_idx - 1] = NULL;

	/* Free name & DMA buffers */
	kfree(ep->ep.name);
	ep->ep.name = NULL;
	dma_free_coherent(&ep->vhub->pdev->dev,
			  AST_VHUB_EPn_MAX_PACKET +
			  8 * AST_VHUB_DESCS_COUNT,
			  ep->buf, ep->buf_dma);
	ep->buf = NULL;
	ep->epn.descs = NULL;

	/* Mark free */
	ep->dev = NULL;
}

static const struct usb_ep_ops ast_vhub_epn_ops = {
	.enable		= ast_vhub_epn_enable,
	.disable	= ast_vhub_epn_disable,
	.dispose	= ast_vhub_epn_dispose,
	.queue		= ast_vhub_epn_queue,
	.dequeue	= ast_vhub_epn_dequeue,
	.set_halt	= ast_vhub_epn_set_halt,
	.set_wedge	= ast_vhub_epn_set_wedge,
	.alloc_request	= ast_vhub_alloc_request,
	.free_request	= ast_vhub_free_request,
};

struct ast_vhub_ep *ast_vhub_alloc_epn(struct ast_vhub_dev *d, u8 addr)
{
	struct ast_vhub *vhub = d->vhub;
	struct ast_vhub_ep *ep;
	unsigned long flags;
	int i;

	/* Find a free one (no device) */
	spin_lock_irqsave(&vhub->lock, flags);
	for (i = 0; i < AST_VHUB_NUM_GEN_EPs; i++)
		if (vhub->epns[i].dev == NULL)
			break;
	if (i >= AST_VHUB_NUM_GEN_EPs) {
		spin_unlock_irqrestore(&vhub->lock, flags);
		return NULL;
	}

	/* Set it up */
	ep = &vhub->epns[i];
	ep->dev = d;
	spin_unlock_irqrestore(&vhub->lock, flags);

	DDBG(d, "Allocating gen EP %d for addr %d\n", i, addr);
	INIT_LIST_HEAD(&ep->queue);
	ep->d_idx = addr;
	ep->vhub = vhub;
	ep->ep.ops = &ast_vhub_epn_ops;
	ep->ep.name = kasprintf(GFP_KERNEL, "ep%d", addr);
	d->epns[addr-1] = ep;
	ep->epn.g_idx = i;
	ep->epn.regs = vhub->regs + 0x200 + (i * 0x10);

	ep->buf = dma_alloc_coherent(&vhub->pdev->dev,
				     AST_VHUB_EPn_MAX_PACKET +
				     8 * AST_VHUB_DESCS_COUNT,
				     &ep->buf_dma, GFP_KERNEL);
	if (!ep->buf) {
		kfree(ep->ep.name);
		ep->ep.name = NULL;
		return NULL;
	}
	ep->epn.descs = ep->buf + AST_VHUB_EPn_MAX_PACKET;
	ep->epn.descs_dma = ep->buf_dma + AST_VHUB_EPn_MAX_PACKET;

	usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EPn_MAX_PACKET);
	list_add_tail(&ep->ep.ep_list, &d->gadget.ep_list);
	ep->ep.caps.type_iso = true;
	ep->ep.caps.type_bulk = true;
	ep->ep.caps.type_int = true;
	ep->ep.caps.dir_in = true;
	ep->ep.caps.dir_out = true;

	return ep;
}