1 /*
2  *	uvc_gadget.c  --  USB Video Class Gadget driver
3  *
4  *	Copyright (C) 2009-2010
5  *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
6  *
7  *	This program is free software; you can redistribute it and/or modify
8  *	it under the terms of the GNU General Public License as published by
9  *	the Free Software Foundation; either version 2 of the License, or
10  *	(at your option) any later version.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/errno.h>
17 #include <linux/fs.h>
18 #include <linux/list.h>
19 #include <linux/mutex.h>
20 #include <linux/string.h>
21 #include <linux/usb/ch9.h>
22 #include <linux/usb/gadget.h>
23 #include <linux/usb/video.h>
24 #include <linux/vmalloc.h>
25 #include <linux/wait.h>
26 
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-event.h>
29 
30 #include "u_uvc.h"
31 #include "uvc.h"
32 #include "uvc_configfs.h"
33 #include "uvc_v4l2.h"
34 #include "uvc_video.h"
35 
36 unsigned int uvc_gadget_trace_param;
37 
38 /* --------------------------------------------------------------------------
39  * Function descriptors
40  */
41 
42 /* string IDs are assigned dynamically */
43 
44 #define UVC_STRING_CONTROL_IDX			0
45 #define UVC_STRING_STREAMING_IDX		1
46 
47 static struct usb_string uvc_en_us_strings[] = {
48 	[UVC_STRING_CONTROL_IDX].s = "UVC Camera",
49 	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
50 	{  }
51 };
52 
53 static struct usb_gadget_strings uvc_stringtab = {
54 	.language = 0x0409,	/* en-us */
55 	.strings = uvc_en_us_strings,
56 };
57 
58 static struct usb_gadget_strings *uvc_function_strings[] = {
59 	&uvc_stringtab,
60 	NULL,
61 };
62 
63 #define UVC_INTF_VIDEO_CONTROL			0
64 #define UVC_INTF_VIDEO_STREAMING		1
65 
66 #define UVC_STATUS_MAX_PACKET_SIZE		16	/* 16 bytes status */
67 
68 static struct usb_interface_assoc_descriptor uvc_iad = {
69 	.bLength		= sizeof(uvc_iad),
70 	.bDescriptorType	= USB_DT_INTERFACE_ASSOCIATION,
71 	.bFirstInterface	= 0,
72 	.bInterfaceCount	= 2,
73 	.bFunctionClass		= USB_CLASS_VIDEO,
74 	.bFunctionSubClass	= UVC_SC_VIDEO_INTERFACE_COLLECTION,
75 	.bFunctionProtocol	= 0x00,
76 	.iFunction		= 0,
77 };
78 
79 static struct usb_interface_descriptor uvc_control_intf = {
80 	.bLength		= USB_DT_INTERFACE_SIZE,
81 	.bDescriptorType	= USB_DT_INTERFACE,
82 	.bInterfaceNumber	= UVC_INTF_VIDEO_CONTROL,
83 	.bAlternateSetting	= 0,
84 	.bNumEndpoints		= 1,
85 	.bInterfaceClass	= USB_CLASS_VIDEO,
86 	.bInterfaceSubClass	= UVC_SC_VIDEOCONTROL,
87 	.bInterfaceProtocol	= 0x00,
88 	.iInterface		= 0,
89 };
90 
91 static struct usb_endpoint_descriptor uvc_control_ep = {
92 	.bLength		= USB_DT_ENDPOINT_SIZE,
93 	.bDescriptorType	= USB_DT_ENDPOINT,
94 	.bEndpointAddress	= USB_DIR_IN,
95 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
96 	.wMaxPacketSize		= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
97 	.bInterval		= 8,
98 };
99 
100 static struct usb_ss_ep_comp_descriptor uvc_ss_control_comp = {
101 	.bLength		= sizeof(uvc_ss_control_comp),
102 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
103 	/* The following 3 values can be tweaked if necessary. */
104 	.bMaxBurst		= 0,
105 	.bmAttributes		= 0,
106 	.wBytesPerInterval	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
107 };
108 
109 static struct uvc_control_endpoint_descriptor uvc_control_cs_ep = {
110 	.bLength		= UVC_DT_CONTROL_ENDPOINT_SIZE,
111 	.bDescriptorType	= USB_DT_CS_ENDPOINT,
112 	.bDescriptorSubType	= UVC_EP_INTERRUPT,
113 	.wMaxTransferSize	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
114 };
115 
116 static struct usb_interface_descriptor uvc_streaming_intf_alt0 = {
117 	.bLength		= USB_DT_INTERFACE_SIZE,
118 	.bDescriptorType	= USB_DT_INTERFACE,
119 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
120 	.bAlternateSetting	= 0,
121 	.bNumEndpoints		= 0,
122 	.bInterfaceClass	= USB_CLASS_VIDEO,
123 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
124 	.bInterfaceProtocol	= 0x00,
125 	.iInterface		= 0,
126 };
127 
128 static struct usb_interface_descriptor uvc_streaming_intf_alt1 = {
129 	.bLength		= USB_DT_INTERFACE_SIZE,
130 	.bDescriptorType	= USB_DT_INTERFACE,
131 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
132 	.bAlternateSetting	= 1,
133 	.bNumEndpoints		= 1,
134 	.bInterfaceClass	= USB_CLASS_VIDEO,
135 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
136 	.bInterfaceProtocol	= 0x00,
137 	.iInterface		= 0,
138 };
139 
140 static struct usb_endpoint_descriptor uvc_fs_streaming_ep = {
141 	.bLength		= USB_DT_ENDPOINT_SIZE,
142 	.bDescriptorType	= USB_DT_ENDPOINT,
143 	.bEndpointAddress	= USB_DIR_IN,
144 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
145 				| USB_ENDPOINT_XFER_ISOC,
146 	/* The wMaxPacketSize and bInterval values will be initialized from
147 	 * module parameters.
148 	 */
149 };
150 
151 static struct usb_endpoint_descriptor uvc_hs_streaming_ep = {
152 	.bLength		= USB_DT_ENDPOINT_SIZE,
153 	.bDescriptorType	= USB_DT_ENDPOINT,
154 	.bEndpointAddress	= USB_DIR_IN,
155 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
156 				| USB_ENDPOINT_XFER_ISOC,
157 	/* The wMaxPacketSize and bInterval values will be initialized from
158 	 * module parameters.
159 	 */
160 };
161 
162 static struct usb_endpoint_descriptor uvc_ss_streaming_ep = {
163 	.bLength		= USB_DT_ENDPOINT_SIZE,
164 	.bDescriptorType	= USB_DT_ENDPOINT,
165 
166 	.bEndpointAddress	= USB_DIR_IN,
167 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
168 				| USB_ENDPOINT_XFER_ISOC,
169 	/* The wMaxPacketSize and bInterval values will be initialized from
170 	 * module parameters.
171 	 */
172 };
173 
174 static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
175 	.bLength		= sizeof(uvc_ss_streaming_comp),
176 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
177 	/* The bMaxBurst, bmAttributes and wBytesPerInterval values will be
178 	 * initialized from module parameters.
179 	 */
180 };
181 
182 static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
183 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
184 	(struct usb_descriptor_header *) &uvc_fs_streaming_ep,
185 	NULL,
186 };
187 
188 static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
189 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
190 	(struct usb_descriptor_header *) &uvc_hs_streaming_ep,
191 	NULL,
192 };
193 
194 static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
195 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
196 	(struct usb_descriptor_header *) &uvc_ss_streaming_ep,
197 	(struct usb_descriptor_header *) &uvc_ss_streaming_comp,
198 	NULL,
199 };
200 
201 void uvc_set_trace_param(unsigned int trace)
202 {
203 	uvc_gadget_trace_param = trace;
204 }
205 EXPORT_SYMBOL(uvc_set_trace_param);
206 
207 /* --------------------------------------------------------------------------
208  * Control requests
209  */
210 
211 static void
212 uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
213 {
214 	struct uvc_device *uvc = req->context;
215 	struct v4l2_event v4l2_event;
216 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
217 
218 	if (uvc->event_setup_out) {
219 		uvc->event_setup_out = 0;
220 
221 		memset(&v4l2_event, 0, sizeof(v4l2_event));
222 		v4l2_event.type = UVC_EVENT_DATA;
223 		uvc_event->data.length = req->actual;
224 		memcpy(&uvc_event->data.data, req->buf, req->actual);
225 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
226 	}
227 }
228 
229 static int
230 uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
231 {
232 	struct uvc_device *uvc = to_uvc(f);
233 	struct v4l2_event v4l2_event;
234 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
235 
236 	/* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
237 	 *	ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
238 	 *	le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
239 	 */
240 
241 	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
242 		INFO(f->config->cdev, "invalid request type\n");
243 		return -EINVAL;
244 	}
245 
246 	/* Stall too big requests. */
247 	if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
248 		return -EINVAL;
249 
250 	/* Tell the complete callback to generate an event for the next request
251 	 * that will be enqueued by UVCIOC_SEND_RESPONSE.
252 	 */
253 	uvc->event_setup_out = !(ctrl->bRequestType & USB_DIR_IN);
254 	uvc->event_length = le16_to_cpu(ctrl->wLength);
255 
256 	memset(&v4l2_event, 0, sizeof(v4l2_event));
257 	v4l2_event.type = UVC_EVENT_SETUP;
258 	memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
259 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
260 
261 	return 0;
262 }
263 
264 void uvc_function_setup_continue(struct uvc_device *uvc)
265 {
266 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
267 
268 	usb_composite_setup_continue(cdev);
269 }
270 
271 static int
272 uvc_function_get_alt(struct usb_function *f, unsigned interface)
273 {
274 	struct uvc_device *uvc = to_uvc(f);
275 
276 	INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);
277 
278 	if (interface == uvc->control_intf)
279 		return 0;
280 	else if (interface != uvc->streaming_intf)
281 		return -EINVAL;
282 	else
283 		return uvc->video.ep->enabled ? 1 : 0;
284 }
285 
286 static int
287 uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
288 {
289 	struct uvc_device *uvc = to_uvc(f);
290 	struct usb_composite_dev *cdev = f->config->cdev;
291 	struct v4l2_event v4l2_event;
292 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
293 	int ret;
294 
295 	INFO(cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);
296 
297 	if (interface == uvc->control_intf) {
298 		if (alt)
299 			return -EINVAL;
300 
301 		INFO(cdev, "reset UVC Control\n");
302 		usb_ep_disable(uvc->control_ep);
303 
304 		if (!uvc->control_ep->desc)
305 			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
306 				return -EINVAL;
307 
308 		usb_ep_enable(uvc->control_ep);
309 
310 		if (uvc->state == UVC_STATE_DISCONNECTED) {
311 			memset(&v4l2_event, 0, sizeof(v4l2_event));
312 			v4l2_event.type = UVC_EVENT_CONNECT;
313 			uvc_event->speed = cdev->gadget->speed;
314 			v4l2_event_queue(&uvc->vdev, &v4l2_event);
315 
316 			uvc->state = UVC_STATE_CONNECTED;
317 		}
318 
319 		return 0;
320 	}
321 
322 	if (interface != uvc->streaming_intf)
323 		return -EINVAL;
324 
325 	/* TODO
326 	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
327 		return alt ? -EINVAL : 0;
328 	*/
329 
330 	switch (alt) {
331 	case 0:
332 		if (uvc->state != UVC_STATE_STREAMING)
333 			return 0;
334 
335 		if (uvc->video.ep)
336 			usb_ep_disable(uvc->video.ep);
337 
338 		memset(&v4l2_event, 0, sizeof(v4l2_event));
339 		v4l2_event.type = UVC_EVENT_STREAMOFF;
340 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
341 
342 		uvc->state = UVC_STATE_CONNECTED;
343 		return 0;
344 
345 	case 1:
346 		if (uvc->state != UVC_STATE_CONNECTED)
347 			return 0;
348 
349 		if (!uvc->video.ep)
350 			return -EINVAL;
351 
352 		INFO(cdev, "reset UVC\n");
353 		usb_ep_disable(uvc->video.ep);
354 
355 		ret = config_ep_by_speed(f->config->cdev->gadget,
356 				&(uvc->func), uvc->video.ep);
357 		if (ret)
358 			return ret;
359 		usb_ep_enable(uvc->video.ep);
360 
361 		memset(&v4l2_event, 0, sizeof(v4l2_event));
362 		v4l2_event.type = UVC_EVENT_STREAMON;
363 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
364 		return USB_GADGET_DELAYED_STATUS;
365 
366 	default:
367 		return -EINVAL;
368 	}
369 }
370 
371 static void
372 uvc_function_disable(struct usb_function *f)
373 {
374 	struct uvc_device *uvc = to_uvc(f);
375 	struct v4l2_event v4l2_event;
376 
377 	INFO(f->config->cdev, "uvc_function_disable\n");
378 
379 	memset(&v4l2_event, 0, sizeof(v4l2_event));
380 	v4l2_event.type = UVC_EVENT_DISCONNECT;
381 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
382 
383 	uvc->state = UVC_STATE_DISCONNECTED;
384 
385 	usb_ep_disable(uvc->video.ep);
386 	usb_ep_disable(uvc->control_ep);
387 }
388 
389 /* --------------------------------------------------------------------------
390  * Connection / disconnection
391  */
392 
393 void
394 uvc_function_connect(struct uvc_device *uvc)
395 {
396 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
397 	int ret;
398 
399 	if ((ret = usb_function_activate(&uvc->func)) < 0)
400 		INFO(cdev, "UVC connect failed with %d\n", ret);
401 }
402 
403 void
404 uvc_function_disconnect(struct uvc_device *uvc)
405 {
406 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
407 	int ret;
408 
409 	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
410 		INFO(cdev, "UVC disconnect failed with %d\n", ret);
411 }
412 
413 /* --------------------------------------------------------------------------
414  * USB probe and disconnect
415  */
416 
417 static int
418 uvc_register_video(struct uvc_device *uvc)
419 {
420 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
421 
422 	/* TODO reference counting. */
423 	uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
424 	uvc->vdev.fops = &uvc_v4l2_fops;
425 	uvc->vdev.ioctl_ops = &uvc_v4l2_ioctl_ops;
426 	uvc->vdev.release = video_device_release_empty;
427 	uvc->vdev.vfl_dir = VFL_DIR_TX;
428 	uvc->vdev.lock = &uvc->video.mutex;
429 	strlcpy(uvc->vdev.name, cdev->gadget->name, sizeof(uvc->vdev.name));
430 
431 	video_set_drvdata(&uvc->vdev, uvc);
432 
433 	return video_register_device(&uvc->vdev, VFL_TYPE_GRABBER, -1);
434 }
435 
436 #define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
437 	do { \
438 		memcpy(mem, desc, (desc)->bLength); \
439 		*(dst)++ = mem; \
440 		mem += (desc)->bLength; \
441 	} while (0);
442 
443 #define UVC_COPY_DESCRIPTORS(mem, dst, src) \
444 	do { \
445 		const struct usb_descriptor_header * const *__src; \
446 		for (__src = src; *__src; ++__src) { \
447 			memcpy(mem, *__src, (*__src)->bLength); \
448 			*dst++ = mem; \
449 			mem += (*__src)->bLength; \
450 		} \
451 	} while (0)
452 
453 static struct usb_descriptor_header **
454 uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
455 {
456 	struct uvc_input_header_descriptor *uvc_streaming_header;
457 	struct uvc_header_descriptor *uvc_control_header;
458 	const struct uvc_descriptor_header * const *uvc_control_desc;
459 	const struct uvc_descriptor_header * const *uvc_streaming_cls;
460 	const struct usb_descriptor_header * const *uvc_streaming_std;
461 	const struct usb_descriptor_header * const *src;
462 	struct usb_descriptor_header **dst;
463 	struct usb_descriptor_header **hdr;
464 	unsigned int control_size;
465 	unsigned int streaming_size;
466 	unsigned int n_desc;
467 	unsigned int bytes;
468 	void *mem;
469 
470 	switch (speed) {
471 	case USB_SPEED_SUPER:
472 		uvc_control_desc = uvc->desc.ss_control;
473 		uvc_streaming_cls = uvc->desc.ss_streaming;
474 		uvc_streaming_std = uvc_ss_streaming;
475 		break;
476 
477 	case USB_SPEED_HIGH:
478 		uvc_control_desc = uvc->desc.fs_control;
479 		uvc_streaming_cls = uvc->desc.hs_streaming;
480 		uvc_streaming_std = uvc_hs_streaming;
481 		break;
482 
483 	case USB_SPEED_FULL:
484 	default:
485 		uvc_control_desc = uvc->desc.fs_control;
486 		uvc_streaming_cls = uvc->desc.fs_streaming;
487 		uvc_streaming_std = uvc_fs_streaming;
488 		break;
489 	}
490 
491 	if (!uvc_control_desc || !uvc_streaming_cls)
492 		return ERR_PTR(-ENODEV);
493 
494 	/* Descriptors layout
495 	 *
496 	 * uvc_iad
497 	 * uvc_control_intf
498 	 * Class-specific UVC control descriptors
499 	 * uvc_control_ep
500 	 * uvc_control_cs_ep
501 	 * uvc_ss_control_comp (for SS only)
502 	 * uvc_streaming_intf_alt0
503 	 * Class-specific UVC streaming descriptors
504 	 * uvc_{fs|hs}_streaming
505 	 */
506 
507 	/* Count descriptors and compute their size. */
508 	control_size = 0;
509 	streaming_size = 0;
510 	bytes = uvc_iad.bLength + uvc_control_intf.bLength
511 	      + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
512 	      + uvc_streaming_intf_alt0.bLength;
513 
514 	if (speed == USB_SPEED_SUPER) {
515 		bytes += uvc_ss_control_comp.bLength;
516 		n_desc = 6;
517 	} else {
518 		n_desc = 5;
519 	}
520 
521 	for (src = (const struct usb_descriptor_header **)uvc_control_desc;
522 	     *src; ++src) {
523 		control_size += (*src)->bLength;
524 		bytes += (*src)->bLength;
525 		n_desc++;
526 	}
527 	for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
528 	     *src; ++src) {
529 		streaming_size += (*src)->bLength;
530 		bytes += (*src)->bLength;
531 		n_desc++;
532 	}
533 	for (src = uvc_streaming_std; *src; ++src) {
534 		bytes += (*src)->bLength;
535 		n_desc++;
536 	}
537 
538 	mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
539 	if (mem == NULL)
540 		return NULL;
541 
542 	hdr = mem;
543 	dst = mem;
544 	mem += (n_desc + 1) * sizeof(*src);
545 
546 	/* Copy the descriptors. */
547 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
548 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
549 
550 	uvc_control_header = mem;
551 	UVC_COPY_DESCRIPTORS(mem, dst,
552 		(const struct usb_descriptor_header **)uvc_control_desc);
553 	uvc_control_header->wTotalLength = cpu_to_le16(control_size);
554 	uvc_control_header->bInCollection = 1;
555 	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
556 
557 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
558 	if (speed == USB_SPEED_SUPER)
559 		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_control_comp);
560 
561 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
562 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
563 
564 	uvc_streaming_header = mem;
565 	UVC_COPY_DESCRIPTORS(mem, dst,
566 		(const struct usb_descriptor_header**)uvc_streaming_cls);
567 	uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
568 	uvc_streaming_header->bEndpointAddress = uvc->video.ep->address;
569 
570 	UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
571 
572 	*dst = NULL;
573 	return hdr;
574 }
575 
576 static int
577 uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
578 {
579 	struct usb_composite_dev *cdev = c->cdev;
580 	struct uvc_device *uvc = to_uvc(f);
581 	struct usb_string *us;
582 	unsigned int max_packet_mult;
583 	unsigned int max_packet_size;
584 	struct usb_ep *ep;
585 	struct f_uvc_opts *opts;
586 	int ret = -EINVAL;
587 
588 	INFO(cdev, "uvc_function_bind\n");
589 
590 	opts = fi_to_f_uvc_opts(f->fi);
591 	/* Sanity check the streaming endpoint module parameters.
592 	 */
593 	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
594 	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
595 	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
596 
597 	/* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
598 	if (opts->streaming_maxburst &&
599 	    (opts->streaming_maxpacket % 1024) != 0) {
600 		opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
601 		INFO(cdev, "overriding streaming_maxpacket to %d\n",
602 		     opts->streaming_maxpacket);
603 	}
604 
605 	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
606 	 * module parameters.
607 	 *
608 	 * NOTE: We assume that the user knows what they are doing and won't
609 	 * give parameters that their UDC doesn't support.
610 	 */
611 	if (opts->streaming_maxpacket <= 1024) {
612 		max_packet_mult = 1;
613 		max_packet_size = opts->streaming_maxpacket;
614 	} else if (opts->streaming_maxpacket <= 2048) {
615 		max_packet_mult = 2;
616 		max_packet_size = opts->streaming_maxpacket / 2;
617 	} else {
618 		max_packet_mult = 3;
619 		max_packet_size = opts->streaming_maxpacket / 3;
620 	}
621 
622 	uvc_fs_streaming_ep.wMaxPacketSize =
623 		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
624 	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
625 
626 	uvc_hs_streaming_ep.wMaxPacketSize =
627 		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
628 	uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
629 
630 	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
631 	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
632 	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
633 	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
634 	uvc_ss_streaming_comp.wBytesPerInterval =
635 		cpu_to_le16(max_packet_size * max_packet_mult *
636 			    (opts->streaming_maxburst + 1));
637 
638 	/* Allocate endpoints. */
639 	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
640 	if (!ep) {
641 		INFO(cdev, "Unable to allocate control EP\n");
642 		goto error;
643 	}
644 	uvc->control_ep = ep;
645 
646 	if (gadget_is_superspeed(c->cdev->gadget))
647 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
648 					  &uvc_ss_streaming_comp);
649 	else if (gadget_is_dualspeed(cdev->gadget))
650 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
651 	else
652 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
653 
654 	if (!ep) {
655 		INFO(cdev, "Unable to allocate streaming EP\n");
656 		goto error;
657 	}
658 	uvc->video.ep = ep;
659 
660 	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
661 	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
662 	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;
663 
664 	us = usb_gstrings_attach(cdev, uvc_function_strings,
665 				 ARRAY_SIZE(uvc_en_us_strings));
666 	if (IS_ERR(us)) {
667 		ret = PTR_ERR(us);
668 		goto error;
669 	}
670 	uvc_iad.iFunction = us[UVC_STRING_CONTROL_IDX].id;
671 	uvc_control_intf.iInterface = us[UVC_STRING_CONTROL_IDX].id;
672 	ret = us[UVC_STRING_STREAMING_IDX].id;
673 	uvc_streaming_intf_alt0.iInterface = ret;
674 	uvc_streaming_intf_alt1.iInterface = ret;
675 
676 	/* Allocate interface IDs. */
677 	if ((ret = usb_interface_id(c, f)) < 0)
678 		goto error;
679 	uvc_iad.bFirstInterface = ret;
680 	uvc_control_intf.bInterfaceNumber = ret;
681 	uvc->control_intf = ret;
682 
683 	if ((ret = usb_interface_id(c, f)) < 0)
684 		goto error;
685 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
686 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
687 	uvc->streaming_intf = ret;
688 
689 	/* Copy descriptors */
690 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
691 	if (IS_ERR(f->fs_descriptors)) {
692 		ret = PTR_ERR(f->fs_descriptors);
693 		f->fs_descriptors = NULL;
694 		goto error;
695 	}
696 	if (gadget_is_dualspeed(cdev->gadget)) {
697 		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
698 		if (IS_ERR(f->hs_descriptors)) {
699 			ret = PTR_ERR(f->hs_descriptors);
700 			f->hs_descriptors = NULL;
701 			goto error;
702 		}
703 	}
704 	if (gadget_is_superspeed(c->cdev->gadget)) {
705 		f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);
706 		if (IS_ERR(f->ss_descriptors)) {
707 			ret = PTR_ERR(f->ss_descriptors);
708 			f->ss_descriptors = NULL;
709 			goto error;
710 		}
711 	}
712 
713 	/* Preallocate control endpoint request. */
714 	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
715 	uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
716 	if (uvc->control_req == NULL || uvc->control_buf == NULL) {
717 		ret = -ENOMEM;
718 		goto error;
719 	}
720 
721 	uvc->control_req->buf = uvc->control_buf;
722 	uvc->control_req->complete = uvc_function_ep0_complete;
723 	uvc->control_req->context = uvc;
724 
725 	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
726 		printk(KERN_INFO "v4l2_device_register failed\n");
727 		goto error;
728 	}
729 
730 	/* Initialise video. */
731 	ret = uvcg_video_init(&uvc->video);
732 	if (ret < 0)
733 		goto error;
734 
735 	/* Register a V4L2 device. */
736 	ret = uvc_register_video(uvc);
737 	if (ret < 0) {
738 		printk(KERN_INFO "Unable to register video device\n");
739 		goto error;
740 	}
741 
742 	return 0;
743 
744 error:
745 	v4l2_device_unregister(&uvc->v4l2_dev);
746 
747 	if (uvc->control_req)
748 		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
749 	kfree(uvc->control_buf);
750 
751 	usb_free_all_descriptors(f);
752 	return ret;
753 }
754 
755 /* --------------------------------------------------------------------------
756  * USB gadget function
757  */
758 
759 static void uvc_free_inst(struct usb_function_instance *f)
760 {
761 	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f);
762 
763 	mutex_destroy(&opts->lock);
764 	kfree(opts);
765 }
766 
767 static struct usb_function_instance *uvc_alloc_inst(void)
768 {
769 	struct f_uvc_opts *opts;
770 	struct uvc_camera_terminal_descriptor *cd;
771 	struct uvc_processing_unit_descriptor *pd;
772 	struct uvc_output_terminal_descriptor *od;
773 	struct uvc_color_matching_descriptor *md;
774 	struct uvc_descriptor_header **ctl_cls;
775 
776 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
777 	if (!opts)
778 		return ERR_PTR(-ENOMEM);
779 	opts->func_inst.free_func_inst = uvc_free_inst;
780 	mutex_init(&opts->lock);
781 
782 	cd = &opts->uvc_camera_terminal;
783 	cd->bLength			= UVC_DT_CAMERA_TERMINAL_SIZE(3);
784 	cd->bDescriptorType		= USB_DT_CS_INTERFACE;
785 	cd->bDescriptorSubType		= UVC_VC_INPUT_TERMINAL;
786 	cd->bTerminalID			= 1;
787 	cd->wTerminalType		= cpu_to_le16(0x0201);
788 	cd->bAssocTerminal		= 0;
789 	cd->iTerminal			= 0;
790 	cd->wObjectiveFocalLengthMin	= cpu_to_le16(0);
791 	cd->wObjectiveFocalLengthMax	= cpu_to_le16(0);
792 	cd->wOcularFocalLength		= cpu_to_le16(0);
793 	cd->bControlSize		= 3;
794 	cd->bmControls[0]		= 2;
795 	cd->bmControls[1]		= 0;
796 	cd->bmControls[2]		= 0;
797 
798 	pd = &opts->uvc_processing;
799 	pd->bLength			= UVC_DT_PROCESSING_UNIT_SIZE(2);
800 	pd->bDescriptorType		= USB_DT_CS_INTERFACE;
801 	pd->bDescriptorSubType		= UVC_VC_PROCESSING_UNIT;
802 	pd->bUnitID			= 2;
803 	pd->bSourceID			= 1;
804 	pd->wMaxMultiplier		= cpu_to_le16(16*1024);
805 	pd->bControlSize		= 2;
806 	pd->bmControls[0]		= 1;
807 	pd->bmControls[1]		= 0;
808 	pd->iProcessing			= 0;
809 
810 	od = &opts->uvc_output_terminal;
811 	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;
812 	od->bDescriptorType		= USB_DT_CS_INTERFACE;
813 	od->bDescriptorSubType		= UVC_VC_OUTPUT_TERMINAL;
814 	od->bTerminalID			= 3;
815 	od->wTerminalType		= cpu_to_le16(0x0101);
816 	od->bAssocTerminal		= 0;
817 	od->bSourceID			= 2;
818 	od->iTerminal			= 0;
819 
820 	md = &opts->uvc_color_matching;
821 	md->bLength			= UVC_DT_COLOR_MATCHING_SIZE;
822 	md->bDescriptorType		= USB_DT_CS_INTERFACE;
823 	md->bDescriptorSubType		= UVC_VS_COLORFORMAT;
824 	md->bColorPrimaries		= 1;
825 	md->bTransferCharacteristics	= 1;
826 	md->bMatrixCoefficients		= 4;
827 
828 	/* Prepare fs control class descriptors for configfs-based gadgets */
829 	ctl_cls = opts->uvc_fs_control_cls;
830 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
831 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
832 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
833 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
834 	ctl_cls[4] = NULL;	/* NULL-terminate */
835 	opts->fs_control =
836 		(const struct uvc_descriptor_header * const *)ctl_cls;
837 
838 	/* Prepare hs control class descriptors for configfs-based gadgets */
839 	ctl_cls = opts->uvc_ss_control_cls;
840 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
841 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
842 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
843 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
844 	ctl_cls[4] = NULL;	/* NULL-terminate */
845 	opts->ss_control =
846 		(const struct uvc_descriptor_header * const *)ctl_cls;
847 
848 	opts->streaming_interval = 1;
849 	opts->streaming_maxpacket = 1024;
850 
851 	uvcg_attach_configfs(opts);
852 	return &opts->func_inst;
853 }
854 
855 static void uvc_free(struct usb_function *f)
856 {
857 	struct uvc_device *uvc = to_uvc(f);
858 	struct f_uvc_opts *opts = container_of(f->fi, struct f_uvc_opts,
859 					       func_inst);
860 	--opts->refcnt;
861 	kfree(uvc);
862 }
863 
864 static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
865 {
866 	struct usb_composite_dev *cdev = c->cdev;
867 	struct uvc_device *uvc = to_uvc(f);
868 
869 	INFO(cdev, "%s\n", __func__);
870 
871 	video_unregister_device(&uvc->vdev);
872 	v4l2_device_unregister(&uvc->v4l2_dev);
873 
874 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
875 	kfree(uvc->control_buf);
876 
877 	usb_free_all_descriptors(f);
878 }
879 
880 static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
881 {
882 	struct uvc_device *uvc;
883 	struct f_uvc_opts *opts;
884 	struct uvc_descriptor_header **strm_cls;
885 
886 	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
887 	if (uvc == NULL)
888 		return ERR_PTR(-ENOMEM);
889 
890 	mutex_init(&uvc->video.mutex);
891 	uvc->state = UVC_STATE_DISCONNECTED;
892 	opts = fi_to_f_uvc_opts(fi);
893 
894 	mutex_lock(&opts->lock);
895 	if (opts->uvc_fs_streaming_cls) {
896 		strm_cls = opts->uvc_fs_streaming_cls;
897 		opts->fs_streaming =
898 			(const struct uvc_descriptor_header * const *)strm_cls;
899 	}
900 	if (opts->uvc_hs_streaming_cls) {
901 		strm_cls = opts->uvc_hs_streaming_cls;
902 		opts->hs_streaming =
903 			(const struct uvc_descriptor_header * const *)strm_cls;
904 	}
905 	if (opts->uvc_ss_streaming_cls) {
906 		strm_cls = opts->uvc_ss_streaming_cls;
907 		opts->ss_streaming =
908 			(const struct uvc_descriptor_header * const *)strm_cls;
909 	}
910 
911 	uvc->desc.fs_control = opts->fs_control;
912 	uvc->desc.ss_control = opts->ss_control;
913 	uvc->desc.fs_streaming = opts->fs_streaming;
914 	uvc->desc.hs_streaming = opts->hs_streaming;
915 	uvc->desc.ss_streaming = opts->ss_streaming;
916 	++opts->refcnt;
917 	mutex_unlock(&opts->lock);
918 
919 	/* Register the function. */
920 	uvc->func.name = "uvc";
921 	uvc->func.bind = uvc_function_bind;
922 	uvc->func.unbind = uvc_unbind;
923 	uvc->func.get_alt = uvc_function_get_alt;
924 	uvc->func.set_alt = uvc_function_set_alt;
925 	uvc->func.disable = uvc_function_disable;
926 	uvc->func.setup = uvc_function_setup;
927 	uvc->func.free_func = uvc_free;
928 	uvc->func.bind_deactivated = true;
929 
930 	return &uvc->func;
931 }
932 
933 DECLARE_USB_FUNCTION_INIT(uvc, uvc_alloc_inst, uvc_alloc);
934 MODULE_LICENSE("GPL");
935 MODULE_AUTHOR("Laurent Pinchart");
936