zero.c 36.6 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
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
/*
 * zero.c -- Gadget Zero, for USB development
 *
 * Copyright (C) 2003-2004 David Brownell
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The names of the above-listed copyright holders may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") as published by the Free Software
 * Foundation, either version 2 of that License or (at your option) any
 * later version.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


/*
 * Gadget Zero only needs two bulk endpoints, and is an example of how you
 * can write a hardware-agnostic gadget driver running inside a USB device.
 *
 * Hardware details are visible (see CONFIG_USB_ZERO_* below) but don't
 * affect most of the driver.
 *
 * Use it with the Linux host/master side "usbtest" driver to get a basic
 * functional test of your device-side usb stack, or with "usb-skeleton".
 *
 * It supports two similar configurations.  One sinks whatever the usb host
 * writes, and in return sources zeroes.  The other loops whatever the host
 * writes back, so the host can read it.  Module options include:
 *
 *   buflen=N		default N=4096, buffer size used
 *   qlen=N		default N=32, how many buffers in the loopback queue
 *   loopdefault	default false, list loopback config first
 *
 * Many drivers will only have one configuration, letting them be much
 * simpler if they also don't support high speed operation (like this
 * driver does).
 */

#define DEBUG 1
// #define VERBOSE

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/utsname.h>
#include <linux/device.h>
#include <linux/moduleparam.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>

#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>

#include "gadget_chips.h"


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

#define DRIVER_VERSION		"St Patrick's Day 2004"

static const char shortname [] = "zero";
static const char longname [] = "Gadget Zero";

static const char source_sink [] = "source and sink data";
static const char loopback [] = "loop input to output";

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

/*
 * driver assumes self-powered hardware, and
 * has no way for users to trigger remote wakeup.
 *
 * this version autoconfigures as much as possible,
 * which is reasonable for most "bulk-only" drivers.
 */
static const char *EP_IN_NAME;		/* source */
static const char *EP_OUT_NAME;		/* sink */

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

/* big enough to hold our biggest descriptor */
#define USB_BUFSIZ	256

struct zero_dev {
	spinlock_t		lock;
	struct usb_gadget	*gadget;
	struct usb_request	*req;		/* for control responses */

	/* when configured, we have one of two configs:
	 * - source data (in to host) and sink it (out from host)
	 * - or loop it back (out from host back in to host)
	 */
	u8			config;
	struct usb_ep		*in_ep, *out_ep;

	/* autoresume timer */
	struct timer_list	resume;
};

#define xprintk(d,level,fmt,args...) \
	dev_printk(level , &(d)->gadget->dev , fmt , ## args)

#ifdef DEBUG
#define DBG(dev,fmt,args...) \
	xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev,fmt,args...) \
	do { } while (0)
#endif /* DEBUG */

#ifdef VERBOSE
#define VDBG	DBG
#else
#define VDBG(dev,fmt,args...) \
	do { } while (0)
#endif /* VERBOSE */

#define ERROR(dev,fmt,args...) \
	xprintk(dev , KERN_ERR , fmt , ## args)
#define WARN(dev,fmt,args...) \
	xprintk(dev , KERN_WARNING , fmt , ## args)
#define INFO(dev,fmt,args...) \
	xprintk(dev , KERN_INFO , fmt , ## args)

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

static unsigned buflen = 4096;
static unsigned qlen = 32;
static unsigned pattern = 0;

module_param (buflen, uint, S_IRUGO|S_IWUSR);
module_param (qlen, uint, S_IRUGO|S_IWUSR);
module_param (pattern, uint, S_IRUGO|S_IWUSR);

/*
 * if it's nonzero, autoresume says how many seconds to wait
 * before trying to wake up the host after suspend.
 */
static unsigned autoresume = 0;
module_param (autoresume, uint, 0);

/*
 * Normally the "loopback" configuration is second (index 1) so
 * it's not the default.  Here's where to change that order, to
 * work better with hosts where config changes are problematic.
 * Or controllers (like superh) that only support one config.
 */
static int loopdefault = 0;

module_param (loopdefault, bool, S_IRUGO|S_IWUSR);

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

/* Thanks to NetChip Technologies for donating this product ID.
 *
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#ifndef	CONFIG_USB_ZERO_HNPTEST
#define DRIVER_VENDOR_NUM	0x0525		/* NetChip */
#define DRIVER_PRODUCT_NUM	0xa4a0		/* Linux-USB "Gadget Zero" */
#else
#define DRIVER_VENDOR_NUM	0x1a0a		/* OTG test device IDs */
#define DRIVER_PRODUCT_NUM	0xbadd
#endif

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

/*
 * DESCRIPTORS ... most are static, but strings and (full)
 * configuration descriptors are built on demand.
 */

#define STRING_MANUFACTURER		25
#define STRING_PRODUCT			42
#define STRING_SERIAL			101
#define STRING_SOURCE_SINK		250
#define STRING_LOOPBACK			251

/*
 * This device advertises two configurations; these numbers work
 * on a pxa250 as well as more flexible hardware.
 */
#define	CONFIG_SOURCE_SINK	3
#define	CONFIG_LOOPBACK		2

static struct usb_device_descriptor
device_desc = {
	.bLength =		sizeof device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	.bcdUSB =		__constant_cpu_to_le16 (0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,

	.idVendor =		__constant_cpu_to_le16 (DRIVER_VENDOR_NUM),
	.idProduct =		__constant_cpu_to_le16 (DRIVER_PRODUCT_NUM),
	.iManufacturer =	STRING_MANUFACTURER,
	.iProduct =		STRING_PRODUCT,
	.iSerialNumber =	STRING_SERIAL,
	.bNumConfigurations =	2,
};

static struct usb_config_descriptor
source_sink_config = {
	.bLength =		sizeof source_sink_config,
	.bDescriptorType =	USB_DT_CONFIG,

	/* compute wTotalLength on the fly */
	.bNumInterfaces =	1,
	.bConfigurationValue =	CONFIG_SOURCE_SINK,
	.iConfiguration =	STRING_SOURCE_SINK,
	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
	.bMaxPower =		1,	/* self-powered */
};

static struct usb_config_descriptor
loopback_config = {
	.bLength =		sizeof loopback_config,
	.bDescriptorType =	USB_DT_CONFIG,

	/* compute wTotalLength on the fly */
	.bNumInterfaces =	1,
	.bConfigurationValue =	CONFIG_LOOPBACK,
	.iConfiguration =	STRING_LOOPBACK,
	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
	.bMaxPower =		1,	/* self-powered */
};

static struct usb_otg_descriptor
otg_descriptor = {
	.bLength =		sizeof otg_descriptor,
	.bDescriptorType =	USB_DT_OTG,

	.bmAttributes =		USB_OTG_SRP,
};

/* one interface in each configuration */

static const struct usb_interface_descriptor
source_sink_intf = {
	.bLength =		sizeof source_sink_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.iInterface =		STRING_SOURCE_SINK,
};

static const struct usb_interface_descriptor
loopback_intf = {
	.bLength =		sizeof loopback_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.iInterface =		STRING_LOOPBACK,
};

/* two full speed bulk endpoints; their use is config-dependent */

static struct usb_endpoint_descriptor
fs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor
fs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static const struct usb_descriptor_header *fs_source_sink_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &source_sink_intf,
	(struct usb_descriptor_header *) &fs_sink_desc,
	(struct usb_descriptor_header *) &fs_source_desc,
	NULL,
};

static const struct usb_descriptor_header *fs_loopback_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &fs_sink_desc,
	(struct usb_descriptor_header *) &fs_source_desc,
	NULL,
};

#ifdef	CONFIG_USB_GADGET_DUALSPEED

/*
 * usb 2.0 devices need to expose both high speed and full speed
 * descriptors, unless they only run at full speed.
 *
 * that means alternate endpoint descriptors (bigger packets)
 * and a "device qualifier" ... plus more construction options
 * for the config descriptor.
 */

static struct usb_endpoint_descriptor
hs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16 (512),
};

static struct usb_endpoint_descriptor
hs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16 (512),
};

static struct usb_qualifier_descriptor
dev_qualifier = {
	.bLength =		sizeof dev_qualifier,
	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,

	.bcdUSB =		__constant_cpu_to_le16 (0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,

	.bNumConfigurations =	2,
};

static const struct usb_descriptor_header *hs_source_sink_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &source_sink_intf,
	(struct usb_descriptor_header *) &hs_source_desc,
	(struct usb_descriptor_header *) &hs_sink_desc,
	NULL,
};

static const struct usb_descriptor_header *hs_loopback_function [] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &hs_source_desc,
	(struct usb_descriptor_header *) &hs_sink_desc,
	NULL,
};

/* maxpacket and other transfer characteristics vary by speed. */
#define ep_desc(g,hs,fs) (((g)->speed==USB_SPEED_HIGH)?(hs):(fs))

#else

/* if there's no high speed support, maxpacket doesn't change. */
#define ep_desc(g,hs,fs) fs

#endif	/* !CONFIG_USB_GADGET_DUALSPEED */

static char				manufacturer [50];
static char				serial [40];

/* static strings, in UTF-8 */
static struct usb_string		strings [] = {
	{ STRING_MANUFACTURER, manufacturer, },
	{ STRING_PRODUCT, longname, },
	{ STRING_SERIAL, serial, },
	{ STRING_LOOPBACK, loopback, },
	{ STRING_SOURCE_SINK, source_sink, },
	{  }			/* end of list */
};

static struct usb_gadget_strings	stringtab = {
	.language	= 0x0409,	/* en-us */
	.strings	= strings,
};

/*
 * config descriptors are also handcrafted.  these must agree with code
 * that sets configurations, and with code managing interfaces and their
 * altsettings.  other complexity may come from:
 *
 *  - high speed support, including "other speed config" rules
 *  - multiple configurations
 *  - interfaces with alternate settings
 *  - embedded class or vendor-specific descriptors
 *
 * this handles high speed, and has a second config that could as easily
 * have been an alternate interface setting (on most hardware).
 *
 * NOTE:  to demonstrate (and test) more USB capabilities, this driver
 * should include an altsetting to test interrupt transfers, including
 * high bandwidth modes at high speed.  (Maybe work like Intel's test
 * device?)
 */
static int
config_buf (struct usb_gadget *gadget,
		u8 *buf, u8 type, unsigned index)
{
	int				is_source_sink;
	int				len;
	const struct usb_descriptor_header **function;
#ifdef CONFIG_USB_GADGET_DUALSPEED
	int				hs = (gadget->speed == USB_SPEED_HIGH);
#endif

	/* two configurations will always be index 0 and index 1 */
	if (index > 1)
		return -EINVAL;
	is_source_sink = loopdefault ? (index == 1) : (index == 0);

#ifdef CONFIG_USB_GADGET_DUALSPEED
	if (type == USB_DT_OTHER_SPEED_CONFIG)
		hs = !hs;
	if (hs)
		function = is_source_sink
			? hs_source_sink_function
			: hs_loopback_function;
	else
#endif
		function = is_source_sink
			? fs_source_sink_function
			: fs_loopback_function;

	/* for now, don't advertise srp-only devices */
	if (!gadget->is_otg)
		function++;

	len = usb_gadget_config_buf (is_source_sink
					? &source_sink_config
					: &loopback_config,
			buf, USB_BUFSIZ, function);
	if (len < 0)
		return len;
	((struct usb_config_descriptor *) buf)->bDescriptorType = type;
	return len;
}

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

static struct usb_request *
alloc_ep_req (struct usb_ep *ep, unsigned length)
{
	struct usb_request	*req;

	req = usb_ep_alloc_request (ep, GFP_ATOMIC);
	if (req) {
		req->length = length;
		req->buf = usb_ep_alloc_buffer (ep, length,
				&req->dma, GFP_ATOMIC);
		if (!req->buf) {
			usb_ep_free_request (ep, req);
			req = NULL;
		}
	}
	return req;
}

static void free_ep_req (struct usb_ep *ep, struct usb_request *req)
{
	if (req->buf)
		usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
	usb_ep_free_request (ep, req);
}

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

/* optionally require specific source/sink data patterns  */

static int
check_read_data (
	struct zero_dev		*dev,
	struct usb_ep		*ep,
	struct usb_request	*req
)
{
	unsigned	i;
	u8		*buf = req->buf;

	for (i = 0; i < req->actual; i++, buf++) {
		switch (pattern) {
		/* all-zeroes has no synchronization issues */
		case 0:
			if (*buf == 0)
				continue;
			break;
		/* mod63 stays in sync with short-terminated transfers,
		 * or otherwise when host and gadget agree on how large
		 * each usb transfer request should be.  resync is done
		 * with set_interface or set_config.
		 */
		case 1:
			if (*buf == (u8)(i % 63))
				continue;
			break;
		}
		ERROR (dev, "bad OUT byte, buf [%d] = %d\n", i, *buf);
		usb_ep_set_halt (ep);
		return -EINVAL;
	}
	return 0;
}

static void
reinit_write_data (
	struct zero_dev		*dev,
	struct usb_ep		*ep,
	struct usb_request	*req
)
{
	unsigned	i;
	u8		*buf = req->buf;

	switch (pattern) {
	case 0:
		memset (req->buf, 0, req->length);
		break;
	case 1:
		for  (i = 0; i < req->length; i++)
			*buf++ = (u8) (i % 63);
		break;
	}
}

/* if there is only one request in the queue, there'll always be an
 * irq delay between end of one request and start of the next.
 * that prevents using hardware dma queues.
 */
static void source_sink_complete (struct usb_ep *ep, struct usb_request *req)
{
	struct zero_dev	*dev = ep->driver_data;
	int		status = req->status;

	switch (status) {

	case 0: 			/* normal completion? */
		if (ep == dev->out_ep)
			check_read_data (dev, ep, req);
		else
			reinit_write_data (dev, ep, req);
		break;

	/* this endpoint is normally active while we're configured */
	case -ECONNABORTED: 		/* hardware forced ep reset */
	case -ECONNRESET:		/* request dequeued */
	case -ESHUTDOWN:		/* disconnect from host */
		VDBG (dev, "%s gone (%d), %d/%d\n", ep->name, status,
				req->actual, req->length);
		if (ep == dev->out_ep)
			check_read_data (dev, ep, req);
		free_ep_req (ep, req);
		return;

	case -EOVERFLOW:		/* buffer overrun on read means that
					 * we didn't provide a big enough
					 * buffer.
					 */
	default:
#if 1
		DBG (dev, "%s complete --> %d, %d/%d\n", ep->name,
				status, req->actual, req->length);
#endif
	case -EREMOTEIO:		/* short read */
		break;
	}

	status = usb_ep_queue (ep, req, GFP_ATOMIC);
	if (status) {
		ERROR (dev, "kill %s:  resubmit %d bytes --> %d\n",
				ep->name, req->length, status);
		usb_ep_set_halt (ep);
		/* FIXME recover later ... somehow */
	}
}

static struct usb_request *
source_sink_start_ep (struct usb_ep *ep, int gfp_flags)
{
	struct usb_request	*req;
	int			status;

	req = alloc_ep_req (ep, buflen);
	if (!req)
		return NULL;

	memset (req->buf, 0, req->length);
	req->complete = source_sink_complete;

	if (strcmp (ep->name, EP_IN_NAME) == 0)
		reinit_write_data (ep->driver_data, ep, req);

	status = usb_ep_queue (ep, req, gfp_flags);
	if (status) {
		struct zero_dev	*dev = ep->driver_data;

		ERROR (dev, "start %s --> %d\n", ep->name, status);
		free_ep_req (ep, req);
		req = NULL;
	}

	return req;
}

static int
set_source_sink_config (struct zero_dev *dev, int gfp_flags)
{
	int			result = 0;
	struct usb_ep		*ep;
	struct usb_gadget	*gadget = dev->gadget;

	gadget_for_each_ep (ep, gadget) {
		const struct usb_endpoint_descriptor	*d;

		/* one endpoint writes (sources) zeroes in (to the host) */
		if (strcmp (ep->name, EP_IN_NAME) == 0) {
			d = ep_desc (gadget, &hs_source_desc, &fs_source_desc);
			result = usb_ep_enable (ep, d);
			if (result == 0) {
				ep->driver_data = dev;
				if (source_sink_start_ep (ep, gfp_flags) != 0) {
					dev->in_ep = ep;
					continue;
				}
				usb_ep_disable (ep);
				result = -EIO;
			}

		/* one endpoint reads (sinks) anything out (from the host) */
		} else if (strcmp (ep->name, EP_OUT_NAME) == 0) {
			d = ep_desc (gadget, &hs_sink_desc, &fs_sink_desc);
			result = usb_ep_enable (ep, d);
			if (result == 0) {
				ep->driver_data = dev;
				if (source_sink_start_ep (ep, gfp_flags) != 0) {
					dev->out_ep = ep;
					continue;
				}
				usb_ep_disable (ep);
				result = -EIO;
			}

		/* ignore any other endpoints */
		} else
			continue;

		/* stop on error */
		ERROR (dev, "can't start %s, result %d\n", ep->name, result);
		break;
	}
	if (result == 0)
		DBG (dev, "buflen %d\n", buflen);

	/* caller is responsible for cleanup on error */
	return result;
}

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

static void loopback_complete (struct usb_ep *ep, struct usb_request *req)
{
	struct zero_dev	*dev = ep->driver_data;
	int		status = req->status;

	switch (status) {

	case 0: 			/* normal completion? */
		if (ep == dev->out_ep) {
			/* loop this OUT packet back IN to the host */
			req->zero = (req->actual < req->length);
			req->length = req->actual;
			status = usb_ep_queue (dev->in_ep, req, GFP_ATOMIC);
			if (status == 0)
				return;

			/* "should never get here" */
			ERROR (dev, "can't loop %s to %s: %d\n",
				ep->name, dev->in_ep->name,
				status);
		}

		/* queue the buffer for some later OUT packet */
		req->length = buflen;
		status = usb_ep_queue (dev->out_ep, req, GFP_ATOMIC);
		if (status == 0)
			return;

		/* "should never get here" */
		/* FALLTHROUGH */

	default:
		ERROR (dev, "%s loop complete --> %d, %d/%d\n", ep->name,
				status, req->actual, req->length);
		/* FALLTHROUGH */

	/* NOTE:  since this driver doesn't maintain an explicit record
	 * of requests it submitted (just maintains qlen count), we
	 * rely on the hardware driver to clean up on disconnect or
	 * endpoint disable.
	 */
	case -ECONNABORTED: 		/* hardware forced ep reset */
	case -ECONNRESET:		/* request dequeued */
	case -ESHUTDOWN:		/* disconnect from host */
		free_ep_req (ep, req);
		return;
	}
}

static int
set_loopback_config (struct zero_dev *dev, int gfp_flags)
{
	int			result = 0;
	struct usb_ep		*ep;
	struct usb_gadget	*gadget = dev->gadget;

	gadget_for_each_ep (ep, gadget) {
		const struct usb_endpoint_descriptor	*d;

		/* one endpoint writes data back IN to the host */
		if (strcmp (ep->name, EP_IN_NAME) == 0) {
			d = ep_desc (gadget, &hs_source_desc, &fs_source_desc);
			result = usb_ep_enable (ep, d);
			if (result == 0) {
				ep->driver_data = dev;
				dev->in_ep = ep;
				continue;
			}

		/* one endpoint just reads OUT packets */
		} else if (strcmp (ep->name, EP_OUT_NAME) == 0) {
			d = ep_desc (gadget, &hs_sink_desc, &fs_sink_desc);
			result = usb_ep_enable (ep, d);
			if (result == 0) {
				ep->driver_data = dev;
				dev->out_ep = ep;
				continue;
			}

		/* ignore any other endpoints */
		} else
			continue;

		/* stop on error */
		ERROR (dev, "can't enable %s, result %d\n", ep->name, result);
		break;
	}

	/* allocate a bunch of read buffers and queue them all at once.
	 * we buffer at most 'qlen' transfers; fewer if any need more
	 * than 'buflen' bytes each.
	 */
	if (result == 0) {
		struct usb_request	*req;
		unsigned		i;

		ep = dev->out_ep;
		for (i = 0; i < qlen && result == 0; i++) {
			req = alloc_ep_req (ep, buflen);
			if (req) {
				req->complete = loopback_complete;
				result = usb_ep_queue (ep, req, GFP_ATOMIC);
				if (result)
					DBG (dev, "%s queue req --> %d\n",
							ep->name, result);
			} else
				result = -ENOMEM;
		}
	}
	if (result == 0)
		DBG (dev, "qlen %d, buflen %d\n", qlen, buflen);

	/* caller is responsible for cleanup on error */
	return result;
}

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

static void zero_reset_config (struct zero_dev *dev)
{
	if (dev->config == 0)
		return;

	DBG (dev, "reset config\n");

	/* just disable endpoints, forcing completion of pending i/o.
	 * all our completion handlers free their requests in this case.
	 */
	if (dev->in_ep) {
		usb_ep_disable (dev->in_ep);
		dev->in_ep = NULL;
	}
	if (dev->out_ep) {
		usb_ep_disable (dev->out_ep);
		dev->out_ep = NULL;
	}
	dev->config = 0;
	del_timer (&dev->resume);
}

/* change our operational config.  this code must agree with the code
 * that returns config descriptors, and altsetting code.
 *
 * it's also responsible for power management interactions. some
 * configurations might not work with our current power sources.
 *
 * note that some device controller hardware will constrain what this
 * code can do, perhaps by disallowing more than one configuration or
 * by limiting configuration choices (like the pxa2xx).
 */
static int
zero_set_config (struct zero_dev *dev, unsigned number, int gfp_flags)
{
	int			result = 0;
	struct usb_gadget	*gadget = dev->gadget;

	if (number == dev->config)
		return 0;

	if (gadget_is_sa1100 (gadget) && dev->config) {
		/* tx fifo is full, but we can't clear it...*/
		INFO (dev, "can't change configurations\n");
		return -ESPIPE;
	}
	zero_reset_config (dev);

	switch (number) {
	case CONFIG_SOURCE_SINK:
		result = set_source_sink_config (dev, gfp_flags);
		break;
	case CONFIG_LOOPBACK:
		result = set_loopback_config (dev, gfp_flags);
		break;
	default:
		result = -EINVAL;
		/* FALL THROUGH */
	case 0:
		return result;
	}

	if (!result && (!dev->in_ep || !dev->out_ep))
		result = -ENODEV;
	if (result)
		zero_reset_config (dev);
	else {
		char *speed;

		switch (gadget->speed) {
		case USB_SPEED_LOW:	speed = "low"; break;
		case USB_SPEED_FULL:	speed = "full"; break;
		case USB_SPEED_HIGH:	speed = "high"; break;
		default: 		speed = "?"; break;
		}

		dev->config = number;
		INFO (dev, "%s speed config #%d: %s\n", speed, number,
				(number == CONFIG_SOURCE_SINK)
					? source_sink : loopback);
	}
	return result;
}

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

static void zero_setup_complete (struct usb_ep *ep, struct usb_request *req)
{
	if (req->status || req->actual != req->length)
		DBG ((struct zero_dev *) ep->driver_data,
				"setup complete --> %d, %d/%d\n",
				req->status, req->actual, req->length);
}

/*
 * The setup() callback implements all the ep0 functionality that's
 * not handled lower down, in hardware or the hardware driver (like
 * device and endpoint feature flags, and their status).  It's all
 * housekeeping for the gadget function we're implementing.  Most of
 * the work is in config-specific setup.
 */
static int
zero_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
{
	struct zero_dev		*dev = get_gadget_data (gadget);
	struct usb_request	*req = dev->req;
	int			value = -EOPNOTSUPP;
922
923
924
	u16			w_index = le16_to_cpu(ctrl->wIndex);
	u16			w_value = le16_to_cpu(ctrl->wValue);
	u16			w_length = le16_to_cpu(ctrl->wLength);
Linus Torvalds's avatar
Linus Torvalds committed
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357

	/* usually this stores reply data in the pre-allocated ep0 buffer,
	 * but config change events will reconfigure hardware.
	 */
	req->zero = 0;
	switch (ctrl->bRequest) {

	case USB_REQ_GET_DESCRIPTOR:
		if (ctrl->bRequestType != USB_DIR_IN)
			goto unknown;
		switch (w_value >> 8) {

		case USB_DT_DEVICE:
			value = min (w_length, (u16) sizeof device_desc);
			memcpy (req->buf, &device_desc, value);
			break;
#ifdef CONFIG_USB_GADGET_DUALSPEED
		case USB_DT_DEVICE_QUALIFIER:
			if (!gadget->is_dualspeed)
				break;
			value = min (w_length, (u16) sizeof dev_qualifier);
			memcpy (req->buf, &dev_qualifier, value);
			break;

		case USB_DT_OTHER_SPEED_CONFIG:
			if (!gadget->is_dualspeed)
				break;
			// FALLTHROUGH
#endif /* CONFIG_USB_GADGET_DUALSPEED */
		case USB_DT_CONFIG:
			value = config_buf (gadget, req->buf,
					w_value >> 8,
					w_value & 0xff);
			if (value >= 0)
				value = min (w_length, (u16) value);
			break;

		case USB_DT_STRING:
			/* wIndex == language code.
			 * this driver only handles one language, you can
			 * add string tables for other languages, using
			 * any UTF-8 characters
			 */
			value = usb_gadget_get_string (&stringtab,
					w_value & 0xff, req->buf);
			if (value >= 0)
				value = min (w_length, (u16) value);
			break;
		}
		break;

	/* currently two configs, two speeds */
	case USB_REQ_SET_CONFIGURATION:
		if (ctrl->bRequestType != 0)
			goto unknown;
		if (gadget->a_hnp_support)
			DBG (dev, "HNP available\n");
		else if (gadget->a_alt_hnp_support)
			DBG (dev, "HNP needs a different root port\n");
		else
			VDBG (dev, "HNP inactive\n");
		spin_lock (&dev->lock);
		value = zero_set_config (dev, w_value, GFP_ATOMIC);
		spin_unlock (&dev->lock);
		break;
	case USB_REQ_GET_CONFIGURATION:
		if (ctrl->bRequestType != USB_DIR_IN)
			goto unknown;
		*(u8 *)req->buf = dev->config;
		value = min (w_length, (u16) 1);
		break;

	/* until we add altsetting support, or other interfaces,
	 * only 0/0 are possible.  pxa2xx only supports 0/0 (poorly)
	 * and already killed pending endpoint I/O.
	 */
	case USB_REQ_SET_INTERFACE:
		if (ctrl->bRequestType != USB_RECIP_INTERFACE)
			goto unknown;
		spin_lock (&dev->lock);
		if (dev->config && w_index == 0 && w_value == 0) {
			u8		config = dev->config;

			/* resets interface configuration, forgets about
			 * previous transaction state (queued bufs, etc)
			 * and re-inits endpoint state (toggle etc)
			 * no response queued, just zero status == success.
			 * if we had more than one interface we couldn't
			 * use this "reset the config" shortcut.
			 */
			zero_reset_config (dev);
			zero_set_config (dev, config, GFP_ATOMIC);
			value = 0;
		}
		spin_unlock (&dev->lock);
		break;
	case USB_REQ_GET_INTERFACE:
		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
			goto unknown;
		if (!dev->config)
			break;
		if (w_index != 0) {
			value = -EDOM;
			break;
		}
		*(u8 *)req->buf = 0;
		value = min (w_length, (u16) 1);
		break;

	/*
	 * These are the same vendor-specific requests supported by
	 * Intel's USB 2.0 compliance test devices.  We exceed that
	 * device spec by allowing multiple-packet requests.
	 */
	case 0x5b:	/* control WRITE test -- fill the buffer */
		if (ctrl->bRequestType != (USB_DIR_OUT|USB_TYPE_VENDOR))
			goto unknown;
		if (w_value || w_index)
			break;
		/* just read that many bytes into the buffer */
		if (w_length > USB_BUFSIZ)
			break;
		value = w_length;
		break;
	case 0x5c:	/* control READ test -- return the buffer */
		if (ctrl->bRequestType != (USB_DIR_IN|USB_TYPE_VENDOR))
			goto unknown;
		if (w_value || w_index)
			break;
		/* expect those bytes are still in the buffer; send back */
		if (w_length > USB_BUFSIZ
				|| w_length != req->length)
			break;
		value = w_length;
		break;

	default:
unknown:
		VDBG (dev,
			"unknown control req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
	}

	/* respond with data transfer before status phase? */
	if (value >= 0) {
		req->length = value;
		req->zero = value < w_length;
		value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
		if (value < 0) {
			DBG (dev, "ep_queue --> %d\n", value);
			req->status = 0;
			zero_setup_complete (gadget->ep0, req);
		}
	}

	/* device either stalls (value < 0) or reports success */
	return value;
}

static void
zero_disconnect (struct usb_gadget *gadget)
{
	struct zero_dev		*dev = get_gadget_data (gadget);
	unsigned long		flags;

	spin_lock_irqsave (&dev->lock, flags);
	zero_reset_config (dev);

	/* a more significant application might have some non-usb
	 * activities to quiesce here, saving resources like power
	 * or pushing the notification up a network stack.
	 */
	spin_unlock_irqrestore (&dev->lock, flags);

	/* next we may get setup() calls to enumerate new connections;
	 * or an unbind() during shutdown (including removing module).
	 */
}

static void
zero_autoresume (unsigned long _dev)
{
	struct zero_dev	*dev = (struct zero_dev *) _dev;
	int		status;

	/* normally the host would be woken up for something
	 * more significant than just a timer firing...
	 */
	if (dev->gadget->speed != USB_SPEED_UNKNOWN) {
		status = usb_gadget_wakeup (dev->gadget);
		DBG (dev, "wakeup --> %d\n", status);
	}
}

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

static void
zero_unbind (struct usb_gadget *gadget)
{
	struct zero_dev		*dev = get_gadget_data (gadget);

	DBG (dev, "unbind\n");

	/* we've already been disconnected ... no i/o is active */
	if (dev->req)
		free_ep_req (gadget->ep0, dev->req);
	del_timer_sync (&dev->resume);
	kfree (dev);
	set_gadget_data (gadget, NULL);
}

static int
zero_bind (struct usb_gadget *gadget)
{
	struct zero_dev		*dev;
	struct usb_ep		*ep;

	/* Bulk-only drivers like this one SHOULD be able to
	 * autoconfigure on any sane usb controller driver,
	 * but there may also be important quirks to address.
	 */
	usb_ep_autoconfig_reset (gadget);
	ep = usb_ep_autoconfig (gadget, &fs_source_desc);
	if (!ep) {
autoconf_fail:
		printk (KERN_ERR "%s: can't autoconfigure on %s\n",
			shortname, gadget->name);
		return -ENODEV;
	}
	EP_IN_NAME = ep->name;
	ep->driver_data = ep;	/* claim */
	
	ep = usb_ep_autoconfig (gadget, &fs_sink_desc);
	if (!ep)
		goto autoconf_fail;
	EP_OUT_NAME = ep->name;
	ep->driver_data = ep;	/* claim */


	/*
	 * DRIVER POLICY CHOICE:  you may want to do this differently.
	 * One thing to avoid is reusing a bcdDevice revision code
	 * with different host-visible configurations or behavior
	 * restrictions -- using ep1in/ep2out vs ep1out/ep3in, etc
	 */
	if (gadget_is_net2280 (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0201);
	} else if (gadget_is_pxa (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0203);
#if 0
	} else if (gadget_is_sh(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0204);
		/* SH has only one configuration; see "loopdefault" */
		device_desc.bNumConfigurations = 1;
		/* FIXME make 1 == default.bConfigurationValue */
#endif
	} else if (gadget_is_sa1100 (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0205);
	} else if (gadget_is_goku (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0206);
	} else if (gadget_is_mq11xx (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0207);
	} else if (gadget_is_omap (gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0208);
	} else if (gadget_is_lh7a40x(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0209);
	} else if (gadget_is_n9604(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0210);
	} else if (gadget_is_pxa27x(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0211);
	} else if (gadget_is_s3c2410(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0212);
	} else if (gadget_is_at91(gadget)) {
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x0213);
	} else {
		/* gadget zero is so simple (for now, no altsettings) that
		 * it SHOULD NOT have problems with bulk-capable hardware.
		 * so warn about unrcognized controllers, don't panic.
		 *
		 * things like configuration and altsetting numbering
		 * can need hardware-specific attention though.
		 */
		printk (KERN_WARNING "%s: controller '%s' not recognized\n",
			shortname, gadget->name);
		device_desc.bcdDevice = __constant_cpu_to_le16 (0x9999);
	}


	/* ok, we made sense of the hardware ... */
	dev = kmalloc (sizeof *dev, SLAB_KERNEL);
	if (!dev)
		return -ENOMEM;
	memset (dev, 0, sizeof *dev);
	spin_lock_init (&dev->lock);
	dev->gadget = gadget;
	set_gadget_data (gadget, dev);

	/* preallocate control response and buffer */
	dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
	if (!dev->req)
		goto enomem;
	dev->req->buf = usb_ep_alloc_buffer (gadget->ep0, USB_BUFSIZ,
				&dev->req->dma, GFP_KERNEL);
	if (!dev->req->buf)
		goto enomem;

	dev->req->complete = zero_setup_complete;

	device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;

#ifdef CONFIG_USB_GADGET_DUALSPEED
	/* assume ep0 uses the same value for both speeds ... */
	dev_qualifier.bMaxPacketSize0 = device_desc.bMaxPacketSize0;

	/* and that all endpoints are dual-speed */
	hs_source_desc.bEndpointAddress = fs_source_desc.bEndpointAddress;
	hs_sink_desc.bEndpointAddress = fs_sink_desc.bEndpointAddress;
#endif

	if (gadget->is_otg) {
		otg_descriptor.bmAttributes |= USB_OTG_HNP,
		source_sink_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
		loopback_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	if (gadget->is_otg) {
		otg_descriptor.bmAttributes |= USB_OTG_HNP,
		source_sink_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
		loopback_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	usb_gadget_set_selfpowered (gadget);

	init_timer (&dev->resume);
	dev->resume.function = zero_autoresume;
	dev->resume.data = (unsigned long) dev;
	if (autoresume) {
		source_sink_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
		loopback_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	gadget->ep0->driver_data = dev;

	INFO (dev, "%s, version: " DRIVER_VERSION "\n", longname);
	INFO (dev, "using %s, OUT %s IN %s\n", gadget->name,
		EP_OUT_NAME, EP_IN_NAME);

	snprintf (manufacturer, sizeof manufacturer, "%s %s with %s",
		system_utsname.sysname, system_utsname.release,
		gadget->name);

	return 0;

enomem:
	zero_unbind (gadget);
	return -ENOMEM;
}

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

static void
zero_suspend (struct usb_gadget *gadget)
{
	struct zero_dev		*dev = get_gadget_data (gadget);

	if (gadget->speed == USB_SPEED_UNKNOWN)
		return;

	if (autoresume) {
		mod_timer (&dev->resume, jiffies + (HZ * autoresume));
		DBG (dev, "suspend, wakeup in %d seconds\n", autoresume);
	} else
		DBG (dev, "suspend\n");
}

static void
zero_resume (struct usb_gadget *gadget)
{
	struct zero_dev		*dev = get_gadget_data (gadget);

	DBG (dev, "resume\n");
	del_timer (&dev->resume);
}


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

static struct usb_gadget_driver zero_driver = {
#ifdef CONFIG_USB_GADGET_DUALSPEED
	.speed		= USB_SPEED_HIGH,
#else
	.speed		= USB_SPEED_FULL,
#endif
	.function	= (char *) longname,
	.bind		= zero_bind,
	.unbind		= zero_unbind,

	.setup		= zero_setup,
	.disconnect	= zero_disconnect,

	.suspend	= zero_suspend,
	.resume		= zero_resume,

	.driver 	= {
		.name		= (char *) shortname,
		// .shutdown = ...
		// .suspend = ...
		// .resume = ...
	},
};

MODULE_AUTHOR ("David Brownell");
MODULE_LICENSE ("Dual BSD/GPL");


static int __init init (void)
{
	/* a real value would likely come through some id prom
	 * or module option.  this one takes at least two packets.
	 */
	strlcpy (serial, "0123456789.0123456789.0123456789", sizeof serial);

	return usb_gadget_register_driver (&zero_driver);
}
module_init (init);

static void __exit cleanup (void)
{
	usb_gadget_unregister_driver (&zero_driver);
}
module_exit (cleanup);