summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/function/f_uvc.c
blob: 945b3bd2ca98a4847c30ce7e462a691f944051b2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
/*
 *	uvc_gadget.c  --  USB Video Class Gadget driver
 *
 *	Copyright (C) 2009-2010
 *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 *	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/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/video.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-event.h>

#include "uvc.h"
#include "uvc_v4l2.h"
#include "uvc_video.h"
#include "u_uvc.h"

unsigned int uvc_gadget_trace_param;

/* --------------------------------------------------------------------------
 * Function descriptors
 */

/* string IDs are assigned dynamically */

#define UVC_STRING_CONTROL_IDX			0
#define UVC_STRING_STREAMING_IDX		1

static struct usb_string uvc_en_us_strings[] = {
	[UVC_STRING_CONTROL_IDX].s = "UVC Camera",
	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
	{  }
};

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

static struct usb_gadget_strings *uvc_function_strings[] = {
	&uvc_stringtab,
	NULL,
};

#define UVC_INTF_VIDEO_CONTROL			0
#define UVC_INTF_VIDEO_STREAMING		1

#define UVC_STATUS_MAX_PACKET_SIZE		16	/* 16 bytes status */

static struct usb_interface_assoc_descriptor uvc_iad = {
	.bLength		= sizeof(uvc_iad),
	.bDescriptorType	= USB_DT_INTERFACE_ASSOCIATION,
	.bFirstInterface	= 0,
	.bInterfaceCount	= 2,
	.bFunctionClass		= USB_CLASS_VIDEO,
	.bFunctionSubClass	= UVC_SC_VIDEO_INTERFACE_COLLECTION,
	.bFunctionProtocol	= 0x00,
	.iFunction		= 0,
};

static struct usb_interface_descriptor uvc_control_intf = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_CONTROL,
	.bAlternateSetting	= 0,
	.bNumEndpoints		= 1,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOCONTROL,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_endpoint_descriptor uvc_control_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize		= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
	.bInterval		= 8,
};

static struct usb_ss_ep_comp_descriptor uvc_ss_control_comp = {
	.bLength		= sizeof(uvc_ss_control_comp),
	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
	/* The following 3 values can be tweaked if necessary. */
	.bMaxBurst		= 0,
	.bmAttributes		= 0,
	.wBytesPerInterval	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
};

static struct uvc_control_endpoint_descriptor uvc_control_cs_ep = {
	.bLength		= UVC_DT_CONTROL_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_CS_ENDPOINT,
	.bDescriptorSubType	= UVC_EP_INTERRUPT,
	.wMaxTransferSize	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
};

static struct usb_interface_descriptor uvc_streaming_intf_alt0 = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
	.bAlternateSetting	= 0,
	.bNumEndpoints		= 0,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_interface_descriptor uvc_streaming_intf_alt1 = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
	.bAlternateSetting	= 1,
	.bNumEndpoints		= 1,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_endpoint_descriptor uvc_fs_streaming_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/* The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

static struct usb_endpoint_descriptor uvc_hs_streaming_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/* The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

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

	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/* The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
	.bLength		= sizeof(uvc_ss_streaming_comp),
	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
	/* The bMaxBurst, bmAttributes and wBytesPerInterval values will be
	 * initialized from module parameters.
	 */
};

static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
	(struct usb_descriptor_header *) &uvc_fs_streaming_ep,
	NULL,
};

static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
	(struct usb_descriptor_header *) &uvc_hs_streaming_ep,
	NULL,
};

static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
	(struct usb_descriptor_header *) &uvc_ss_streaming_ep,
	(struct usb_descriptor_header *) &uvc_ss_streaming_comp,
	NULL,
};

void uvc_set_trace_param(unsigned int trace)
{
	uvc_gadget_trace_param = trace;
}
EXPORT_SYMBOL(uvc_set_trace_param);

/* --------------------------------------------------------------------------
 * Control requests
 */

static void
uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct uvc_device *uvc = req->context;
	struct v4l2_event v4l2_event;
	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;

	if (uvc->event_setup_out) {
		uvc->event_setup_out = 0;

		memset(&v4l2_event, 0, sizeof(v4l2_event));
		v4l2_event.type = UVC_EVENT_DATA;
		uvc_event->data.length = req->actual;
		memcpy(&uvc_event->data.data, req->buf, req->actual);
		v4l2_event_queue(uvc->vdev, &v4l2_event);
	}
}

static int
uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
	struct uvc_device *uvc = to_uvc(f);
	struct v4l2_event v4l2_event;
	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;

	/* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
	 *	ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
	 *	le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
	 */

	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
		INFO(f->config->cdev, "invalid request type\n");
		return -EINVAL;
	}

	/* Stall too big requests. */
	if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
		return -EINVAL;

	/* Tell the complete callback to generate an event for the next request
	 * that will be enqueued by UVCIOC_SEND_RESPONSE.
	 */
	uvc->event_setup_out = !(ctrl->bRequestType & USB_DIR_IN);
	uvc->event_length = le16_to_cpu(ctrl->wLength);

	memset(&v4l2_event, 0, sizeof(v4l2_event));
	v4l2_event.type = UVC_EVENT_SETUP;
	memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
	v4l2_event_queue(uvc->vdev, &v4l2_event);

	return 0;
}

void uvc_function_setup_continue(struct uvc_device *uvc)
{
	struct usb_composite_dev *cdev = uvc->func.config->cdev;

	usb_composite_setup_continue(cdev);
}

static int
uvc_function_get_alt(struct usb_function *f, unsigned interface)
{
	struct uvc_device *uvc = to_uvc(f);

	INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);

	if (interface == uvc->control_intf)
		return 0;
	else if (interface != uvc->streaming_intf)
		return -EINVAL;
	else
		return uvc->video.ep->driver_data ? 1 : 0;
}

static int
uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
{
	struct uvc_device *uvc = to_uvc(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	struct v4l2_event v4l2_event;
	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
	int ret;

	INFO(cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);

	if (interface == uvc->control_intf) {
		if (alt)
			return -EINVAL;

		if (uvc->control_ep->driver_data) {
			INFO(cdev, "reset UVC Control\n");
			usb_ep_disable(uvc->control_ep);
			uvc->control_ep->driver_data = NULL;
		}

		if (!uvc->control_ep->desc)
			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
				return -EINVAL;

		usb_ep_enable(uvc->control_ep);
		uvc->control_ep->driver_data = uvc;

		if (uvc->state == UVC_STATE_DISCONNECTED) {
			memset(&v4l2_event, 0, sizeof(v4l2_event));
			v4l2_event.type = UVC_EVENT_CONNECT;
			uvc_event->speed = cdev->gadget->speed;
			v4l2_event_queue(uvc->vdev, &v4l2_event);

			uvc->state = UVC_STATE_CONNECTED;
		}

		return 0;
	}

	if (interface != uvc->streaming_intf)
		return -EINVAL;

	/* TODO
	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
		return alt ? -EINVAL : 0;
	*/

	switch (alt) {
	case 0:
		if (uvc->state != UVC_STATE_STREAMING)
			return 0;

		if (uvc->video.ep) {
			usb_ep_disable(uvc->video.ep);
			uvc->video.ep->driver_data = NULL;
		}

		memset(&v4l2_event, 0, sizeof(v4l2_event));
		v4l2_event.type = UVC_EVENT_STREAMOFF;
		v4l2_event_queue(uvc->vdev, &v4l2_event);

		uvc->state = UVC_STATE_CONNECTED;
		return 0;

	case 1:
		if (uvc->state != UVC_STATE_CONNECTED)
			return 0;

		if (!uvc->video.ep)
			return -EINVAL;

		if (uvc->video.ep->driver_data) {
			INFO(cdev, "reset UVC\n");
			usb_ep_disable(uvc->video.ep);
			uvc->video.ep->driver_data = NULL;
		}

		ret = config_ep_by_speed(f->config->cdev->gadget,
				&(uvc->func), uvc->video.ep);
		if (ret)
			return ret;
		usb_ep_enable(uvc->video.ep);
		uvc->video.ep->driver_data = uvc;

		memset(&v4l2_event, 0, sizeof(v4l2_event));
		v4l2_event.type = UVC_EVENT_STREAMON;
		v4l2_event_queue(uvc->vdev, &v4l2_event);
		return USB_GADGET_DELAYED_STATUS;

	default:
		return -EINVAL;
	}
}

static void
uvc_function_disable(struct usb_function *f)
{
	struct uvc_device *uvc = to_uvc(f);
	struct v4l2_event v4l2_event;

	INFO(f->config->cdev, "uvc_function_disable\n");

	memset(&v4l2_event, 0, sizeof(v4l2_event));
	v4l2_event.type = UVC_EVENT_DISCONNECT;
	v4l2_event_queue(uvc->vdev, &v4l2_event);

	uvc->state = UVC_STATE_DISCONNECTED;

	if (uvc->video.ep->driver_data) {
		usb_ep_disable(uvc->video.ep);
		uvc->video.ep->driver_data = NULL;
	}

	if (uvc->control_ep->driver_data) {
		usb_ep_disable(uvc->control_ep);
		uvc->control_ep->driver_data = NULL;
	}
}

/* --------------------------------------------------------------------------
 * Connection / disconnection
 */

void
uvc_function_connect(struct uvc_device *uvc)
{
	struct usb_composite_dev *cdev = uvc->func.config->cdev;
	int ret;

	if ((ret = usb_function_activate(&uvc->func)) < 0)
		INFO(cdev, "UVC connect failed with %d\n", ret);
}

void
uvc_function_disconnect(struct uvc_device *uvc)
{
	struct usb_composite_dev *cdev = uvc->func.config->cdev;
	int ret;

	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
		INFO(cdev, "UVC disconnect failed with %d\n", ret);
}

/* --------------------------------------------------------------------------
 * USB probe and disconnect
 */

static int
uvc_register_video(struct uvc_device *uvc)
{
	struct usb_composite_dev *cdev = uvc->func.config->cdev;
	struct video_device *video;

	/* TODO reference counting. */
	video = video_device_alloc();
	if (video == NULL)
		return -ENOMEM;

	video->v4l2_dev = &uvc->v4l2_dev;
	video->fops = &uvc_v4l2_fops;
	video->ioctl_ops = &uvc_v4l2_ioctl_ops;
	video->release = video_device_release;
	video->vfl_dir = VFL_DIR_TX;
	strlcpy(video->name, cdev->gadget->name, sizeof(video->name));

	uvc->vdev = video;
	video_set_drvdata(video, uvc);

	return video_register_device(video, VFL_TYPE_GRABBER, -1);
}

#define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
	do { \
		memcpy(mem, desc, (desc)->bLength); \
		*(dst)++ = mem; \
		mem += (desc)->bLength; \
	} while (0);

#define UVC_COPY_DESCRIPTORS(mem, dst, src) \
	do { \
		const struct usb_descriptor_header * const *__src; \
		for (__src = src; *__src; ++__src) { \
			memcpy(mem, *__src, (*__src)->bLength); \
			*dst++ = mem; \
			mem += (*__src)->bLength; \
		} \
	} while (0)

static struct usb_descriptor_header **
uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
{
	struct uvc_input_header_descriptor *uvc_streaming_header;
	struct uvc_header_descriptor *uvc_control_header;
	const struct uvc_descriptor_header * const *uvc_control_desc;
	const struct uvc_descriptor_header * const *uvc_streaming_cls;
	const struct usb_descriptor_header * const *uvc_streaming_std;
	const struct usb_descriptor_header * const *src;
	struct usb_descriptor_header **dst;
	struct usb_descriptor_header **hdr;
	unsigned int control_size;
	unsigned int streaming_size;
	unsigned int n_desc;
	unsigned int bytes;
	void *mem;

	switch (speed) {
	case USB_SPEED_SUPER:
		uvc_control_desc = uvc->desc.ss_control;
		uvc_streaming_cls = uvc->desc.ss_streaming;
		uvc_streaming_std = uvc_ss_streaming;
		break;

	case USB_SPEED_HIGH:
		uvc_control_desc = uvc->desc.fs_control;
		uvc_streaming_cls = uvc->desc.hs_streaming;
		uvc_streaming_std = uvc_hs_streaming;
		break;

	case USB_SPEED_FULL:
	default:
		uvc_control_desc = uvc->desc.fs_control;
		uvc_streaming_cls = uvc->desc.fs_streaming;
		uvc_streaming_std = uvc_fs_streaming;
		break;
	}

	/* Descriptors layout
	 *
	 * uvc_iad
	 * uvc_control_intf
	 * Class-specific UVC control descriptors
	 * uvc_control_ep
	 * uvc_control_cs_ep
	 * uvc_ss_control_comp (for SS only)
	 * uvc_streaming_intf_alt0
	 * Class-specific UVC streaming descriptors
	 * uvc_{fs|hs}_streaming
	 */

	/* Count descriptors and compute their size. */
	control_size = 0;
	streaming_size = 0;
	bytes = uvc_iad.bLength + uvc_control_intf.bLength
	      + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
	      + uvc_streaming_intf_alt0.bLength;

	if (speed == USB_SPEED_SUPER) {
		bytes += uvc_ss_control_comp.bLength;
		n_desc = 6;
	} else {
		n_desc = 5;
	}

	for (src = (const struct usb_descriptor_header **)uvc_control_desc;
	     *src; ++src) {
		control_size += (*src)->bLength;
		bytes += (*src)->bLength;
		n_desc++;
	}
	for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
	     *src; ++src) {
		streaming_size += (*src)->bLength;
		bytes += (*src)->bLength;
		n_desc++;
	}
	for (src = uvc_streaming_std; *src; ++src) {
		bytes += (*src)->bLength;
		n_desc++;
	}

	mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
	if (mem == NULL)
		return NULL;

	hdr = mem;
	dst = mem;
	mem += (n_desc + 1) * sizeof(*src);

	/* Copy the descriptors. */
	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);

	uvc_control_header = mem;
	UVC_COPY_DESCRIPTORS(mem, dst,
		(const struct usb_descriptor_header **)uvc_control_desc);
	uvc_control_header->wTotalLength = cpu_to_le16(control_size);
	uvc_control_header->bInCollection = 1;
	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;

	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
	if (speed == USB_SPEED_SUPER)
		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_control_comp);

	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);

	uvc_streaming_header = mem;
	UVC_COPY_DESCRIPTORS(mem, dst,
		(const struct usb_descriptor_header**)uvc_streaming_cls);
	uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
	uvc_streaming_header->bEndpointAddress = uvc->video.ep->address;

	UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);

	*dst = NULL;
	return hdr;
}

static int
uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct uvc_device *uvc = to_uvc(f);
	struct usb_string *us;
	unsigned int max_packet_mult;
	unsigned int max_packet_size;
	struct usb_ep *ep;
	struct f_uvc_opts *opts;
	int ret = -EINVAL;

	INFO(cdev, "uvc_function_bind\n");

	opts = to_f_uvc_opts(f->fi);
	/* Sanity check the streaming endpoint module parameters.
	 */
	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);

	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
	 * module parameters.
	 *
	 * NOTE: We assume that the user knows what they are doing and won't
	 * give parameters that their UDC doesn't support.
	 */
	if (opts->streaming_maxpacket <= 1024) {
		max_packet_mult = 1;
		max_packet_size = opts->streaming_maxpacket;
	} else if (opts->streaming_maxpacket <= 2048) {
		max_packet_mult = 2;
		max_packet_size = opts->streaming_maxpacket / 2;
	} else {
		max_packet_mult = 3;
		max_packet_size = opts->streaming_maxpacket / 3;
	}

	uvc_fs_streaming_ep.wMaxPacketSize =
		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;

	uvc_hs_streaming_ep.wMaxPacketSize =
		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
	uvc_hs_streaming_ep.bInterval = opts->streaming_interval;

	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
	uvc_ss_streaming_comp.wBytesPerInterval =
		cpu_to_le16(max_packet_size * max_packet_mult *
			    opts->streaming_maxburst);

	/* Allocate endpoints. */
	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
	if (!ep) {
		INFO(cdev, "Unable to allocate control EP\n");
		goto error;
	}
	uvc->control_ep = ep;
	ep->driver_data = uvc;

	if (gadget_is_superspeed(c->cdev->gadget))
		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
					  &uvc_ss_streaming_comp);
	else if (gadget_is_dualspeed(cdev->gadget))
		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
	else
		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);

	if (!ep) {
		INFO(cdev, "Unable to allocate streaming EP\n");
		goto error;
	}
	uvc->video.ep = ep;
	ep->driver_data = uvc;

	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;

	us = usb_gstrings_attach(cdev, uvc_function_strings,
				 ARRAY_SIZE(uvc_en_us_strings));
	if (IS_ERR(us)) {
		ret = PTR_ERR(us);
		goto error;
	}
	uvc_iad.iFunction = us[UVC_STRING_CONTROL_IDX].id;
	uvc_control_intf.iInterface = us[UVC_STRING_CONTROL_IDX].id;
	ret = us[UVC_STRING_STREAMING_IDX].id;
	uvc_streaming_intf_alt0.iInterface = ret;
	uvc_streaming_intf_alt1.iInterface = ret;

	/* Allocate interface IDs. */
	if ((ret = usb_interface_id(c, f)) < 0)
		goto error;
	uvc_iad.bFirstInterface = ret;
	uvc_control_intf.bInterfaceNumber = ret;
	uvc->control_intf = ret;

	if ((ret = usb_interface_id(c, f)) < 0)
		goto error;
	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
	uvc->streaming_intf = ret;

	/* Copy descriptors */
	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
	if (gadget_is_dualspeed(cdev->gadget))
		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
	if (gadget_is_superspeed(c->cdev->gadget))
		f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);

	/* Preallocate control endpoint request. */
	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
	uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
	if (uvc->control_req == NULL || uvc->control_buf == NULL) {
		ret = -ENOMEM;
		goto error;
	}

	uvc->control_req->buf = uvc->control_buf;
	uvc->control_req->complete = uvc_function_ep0_complete;
	uvc->control_req->context = uvc;

	/* Avoid letting this gadget enumerate until the userspace server is
	 * active.
	 */
	if ((ret = usb_function_deactivate(f)) < 0)
		goto error;

	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
		printk(KERN_INFO "v4l2_device_register failed\n");
		goto error;
	}

	/* Initialise video. */
	ret = uvcg_video_init(&uvc->video);
	if (ret < 0)
		goto error;

	/* Register a V4L2 device. */
	ret = uvc_register_video(uvc);
	if (ret < 0) {
		printk(KERN_INFO "Unable to register video device\n");
		goto error;
	}

	return 0;

error:
	v4l2_device_unregister(&uvc->v4l2_dev);
	if (uvc->vdev)
		video_device_release(uvc->vdev);

	if (uvc->control_ep)
		uvc->control_ep->driver_data = NULL;
	if (uvc->video.ep)
		uvc->video.ep->driver_data = NULL;

	if (uvc->control_req)
		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
	kfree(uvc->control_buf);

	usb_free_all_descriptors(f);
	return ret;
}

/* --------------------------------------------------------------------------
 * USB gadget function
 */

static void uvc_free_inst(struct usb_function_instance *f)
{
	struct f_uvc_opts *opts = to_f_uvc_opts(f);

	kfree(opts);
}

static struct usb_function_instance *uvc_alloc_inst(void)
{
	struct f_uvc_opts *opts;

	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
	if (!opts)
		return ERR_PTR(-ENOMEM);
	opts->func_inst.free_func_inst = uvc_free_inst;

	return &opts->func_inst;
}

static void uvc_free(struct usb_function *f)
{
	struct uvc_device *uvc = to_uvc(f);

	kfree(uvc);
}

static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct uvc_device *uvc = to_uvc(f);

	INFO(cdev, "%s\n", __func__);

	video_unregister_device(uvc->vdev);
	v4l2_device_unregister(&uvc->v4l2_dev);
	uvc->control_ep->driver_data = NULL;
	uvc->video.ep->driver_data = NULL;

	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
	kfree(uvc->control_buf);

	usb_free_all_descriptors(f);
}

static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
{
	struct uvc_device *uvc;
	struct f_uvc_opts *opts;

	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
	if (uvc == NULL)
		return ERR_PTR(-ENOMEM);

	uvc->state = UVC_STATE_DISCONNECTED;
	opts = to_f_uvc_opts(fi);

	uvc->desc.fs_control = opts->fs_control;
	uvc->desc.ss_control = opts->ss_control;
	uvc->desc.fs_streaming = opts->fs_streaming;
	uvc->desc.hs_streaming = opts->hs_streaming;
	uvc->desc.ss_streaming = opts->ss_streaming;

	/* Register the function. */
	uvc->func.name = "uvc";
	uvc->func.bind = uvc_function_bind;
	uvc->func.unbind = uvc_unbind;
	uvc->func.get_alt = uvc_function_get_alt;
	uvc->func.set_alt = uvc_function_set_alt;
	uvc->func.disable = uvc_function_disable;
	uvc->func.setup = uvc_function_setup;
	uvc->func.free_func = uvc_free;

	return &uvc->func;
}

DECLARE_USB_FUNCTION_INIT(uvc, uvc_alloc_inst, uvc_alloc);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Laurent Pinchart");