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->driver_data ? 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 		if (uvc->control_ep->driver_data) {
302 			INFO(cdev, "reset UVC Control\n");
303 			usb_ep_disable(uvc->control_ep);
304 			uvc->control_ep->driver_data = NULL;
305 		}
306 
307 		if (!uvc->control_ep->desc)
308 			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
309 				return -EINVAL;
310 
311 		usb_ep_enable(uvc->control_ep);
312 		uvc->control_ep->driver_data = uvc;
313 
314 		if (uvc->state == UVC_STATE_DISCONNECTED) {
315 			memset(&v4l2_event, 0, sizeof(v4l2_event));
316 			v4l2_event.type = UVC_EVENT_CONNECT;
317 			uvc_event->speed = cdev->gadget->speed;
318 			v4l2_event_queue(uvc->vdev, &v4l2_event);
319 
320 			uvc->state = UVC_STATE_CONNECTED;
321 		}
322 
323 		return 0;
324 	}
325 
326 	if (interface != uvc->streaming_intf)
327 		return -EINVAL;
328 
329 	/* TODO
330 	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
331 		return alt ? -EINVAL : 0;
332 	*/
333 
334 	switch (alt) {
335 	case 0:
336 		if (uvc->state != UVC_STATE_STREAMING)
337 			return 0;
338 
339 		if (uvc->video.ep) {
340 			usb_ep_disable(uvc->video.ep);
341 			uvc->video.ep->driver_data = NULL;
342 		}
343 
344 		memset(&v4l2_event, 0, sizeof(v4l2_event));
345 		v4l2_event.type = UVC_EVENT_STREAMOFF;
346 		v4l2_event_queue(uvc->vdev, &v4l2_event);
347 
348 		uvc->state = UVC_STATE_CONNECTED;
349 		return 0;
350 
351 	case 1:
352 		if (uvc->state != UVC_STATE_CONNECTED)
353 			return 0;
354 
355 		if (!uvc->video.ep)
356 			return -EINVAL;
357 
358 		if (uvc->video.ep->driver_data) {
359 			INFO(cdev, "reset UVC\n");
360 			usb_ep_disable(uvc->video.ep);
361 			uvc->video.ep->driver_data = NULL;
362 		}
363 
364 		ret = config_ep_by_speed(f->config->cdev->gadget,
365 				&(uvc->func), uvc->video.ep);
366 		if (ret)
367 			return ret;
368 		usb_ep_enable(uvc->video.ep);
369 		uvc->video.ep->driver_data = uvc;
370 
371 		memset(&v4l2_event, 0, sizeof(v4l2_event));
372 		v4l2_event.type = UVC_EVENT_STREAMON;
373 		v4l2_event_queue(uvc->vdev, &v4l2_event);
374 		return USB_GADGET_DELAYED_STATUS;
375 
376 	default:
377 		return -EINVAL;
378 	}
379 }
380 
381 static void
382 uvc_function_disable(struct usb_function *f)
383 {
384 	struct uvc_device *uvc = to_uvc(f);
385 	struct v4l2_event v4l2_event;
386 
387 	INFO(f->config->cdev, "uvc_function_disable\n");
388 
389 	memset(&v4l2_event, 0, sizeof(v4l2_event));
390 	v4l2_event.type = UVC_EVENT_DISCONNECT;
391 	v4l2_event_queue(uvc->vdev, &v4l2_event);
392 
393 	uvc->state = UVC_STATE_DISCONNECTED;
394 
395 	if (uvc->video.ep->driver_data) {
396 		usb_ep_disable(uvc->video.ep);
397 		uvc->video.ep->driver_data = NULL;
398 	}
399 
400 	if (uvc->control_ep->driver_data) {
401 		usb_ep_disable(uvc->control_ep);
402 		uvc->control_ep->driver_data = NULL;
403 	}
404 }
405 
406 /* --------------------------------------------------------------------------
407  * Connection / disconnection
408  */
409 
410 void
411 uvc_function_connect(struct uvc_device *uvc)
412 {
413 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
414 	int ret;
415 
416 	if ((ret = usb_function_activate(&uvc->func)) < 0)
417 		INFO(cdev, "UVC connect failed with %d\n", ret);
418 }
419 
420 void
421 uvc_function_disconnect(struct uvc_device *uvc)
422 {
423 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
424 	int ret;
425 
426 	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
427 		INFO(cdev, "UVC disconnect failed with %d\n", ret);
428 }
429 
430 /* --------------------------------------------------------------------------
431  * USB probe and disconnect
432  */
433 
434 static int
435 uvc_register_video(struct uvc_device *uvc)
436 {
437 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
438 	struct video_device *video;
439 
440 	/* TODO reference counting. */
441 	video = video_device_alloc();
442 	if (video == NULL)
443 		return -ENOMEM;
444 
445 	video->v4l2_dev = &uvc->v4l2_dev;
446 	video->fops = &uvc_v4l2_fops;
447 	video->ioctl_ops = &uvc_v4l2_ioctl_ops;
448 	video->release = video_device_release;
449 	video->vfl_dir = VFL_DIR_TX;
450 	strlcpy(video->name, cdev->gadget->name, sizeof(video->name));
451 
452 	uvc->vdev = video;
453 	video_set_drvdata(video, uvc);
454 
455 	return video_register_device(video, VFL_TYPE_GRABBER, -1);
456 }
457 
458 #define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
459 	do { \
460 		memcpy(mem, desc, (desc)->bLength); \
461 		*(dst)++ = mem; \
462 		mem += (desc)->bLength; \
463 	} while (0);
464 
465 #define UVC_COPY_DESCRIPTORS(mem, dst, src) \
466 	do { \
467 		const struct usb_descriptor_header * const *__src; \
468 		for (__src = src; *__src; ++__src) { \
469 			memcpy(mem, *__src, (*__src)->bLength); \
470 			*dst++ = mem; \
471 			mem += (*__src)->bLength; \
472 		} \
473 	} while (0)
474 
475 static struct usb_descriptor_header **
476 uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
477 {
478 	struct uvc_input_header_descriptor *uvc_streaming_header;
479 	struct uvc_header_descriptor *uvc_control_header;
480 	const struct uvc_descriptor_header * const *uvc_control_desc;
481 	const struct uvc_descriptor_header * const *uvc_streaming_cls;
482 	const struct usb_descriptor_header * const *uvc_streaming_std;
483 	const struct usb_descriptor_header * const *src;
484 	struct usb_descriptor_header **dst;
485 	struct usb_descriptor_header **hdr;
486 	unsigned int control_size;
487 	unsigned int streaming_size;
488 	unsigned int n_desc;
489 	unsigned int bytes;
490 	void *mem;
491 
492 	switch (speed) {
493 	case USB_SPEED_SUPER:
494 		uvc_control_desc = uvc->desc.ss_control;
495 		uvc_streaming_cls = uvc->desc.ss_streaming;
496 		uvc_streaming_std = uvc_ss_streaming;
497 		break;
498 
499 	case USB_SPEED_HIGH:
500 		uvc_control_desc = uvc->desc.fs_control;
501 		uvc_streaming_cls = uvc->desc.hs_streaming;
502 		uvc_streaming_std = uvc_hs_streaming;
503 		break;
504 
505 	case USB_SPEED_FULL:
506 	default:
507 		uvc_control_desc = uvc->desc.fs_control;
508 		uvc_streaming_cls = uvc->desc.fs_streaming;
509 		uvc_streaming_std = uvc_fs_streaming;
510 		break;
511 	}
512 
513 	if (!uvc_control_desc || !uvc_streaming_cls)
514 		return ERR_PTR(-ENODEV);
515 
516 	/* Descriptors layout
517 	 *
518 	 * uvc_iad
519 	 * uvc_control_intf
520 	 * Class-specific UVC control descriptors
521 	 * uvc_control_ep
522 	 * uvc_control_cs_ep
523 	 * uvc_ss_control_comp (for SS only)
524 	 * uvc_streaming_intf_alt0
525 	 * Class-specific UVC streaming descriptors
526 	 * uvc_{fs|hs}_streaming
527 	 */
528 
529 	/* Count descriptors and compute their size. */
530 	control_size = 0;
531 	streaming_size = 0;
532 	bytes = uvc_iad.bLength + uvc_control_intf.bLength
533 	      + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
534 	      + uvc_streaming_intf_alt0.bLength;
535 
536 	if (speed == USB_SPEED_SUPER) {
537 		bytes += uvc_ss_control_comp.bLength;
538 		n_desc = 6;
539 	} else {
540 		n_desc = 5;
541 	}
542 
543 	for (src = (const struct usb_descriptor_header **)uvc_control_desc;
544 	     *src; ++src) {
545 		control_size += (*src)->bLength;
546 		bytes += (*src)->bLength;
547 		n_desc++;
548 	}
549 	for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
550 	     *src; ++src) {
551 		streaming_size += (*src)->bLength;
552 		bytes += (*src)->bLength;
553 		n_desc++;
554 	}
555 	for (src = uvc_streaming_std; *src; ++src) {
556 		bytes += (*src)->bLength;
557 		n_desc++;
558 	}
559 
560 	mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
561 	if (mem == NULL)
562 		return NULL;
563 
564 	hdr = mem;
565 	dst = mem;
566 	mem += (n_desc + 1) * sizeof(*src);
567 
568 	/* Copy the descriptors. */
569 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
570 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
571 
572 	uvc_control_header = mem;
573 	UVC_COPY_DESCRIPTORS(mem, dst,
574 		(const struct usb_descriptor_header **)uvc_control_desc);
575 	uvc_control_header->wTotalLength = cpu_to_le16(control_size);
576 	uvc_control_header->bInCollection = 1;
577 	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
578 
579 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
580 	if (speed == USB_SPEED_SUPER)
581 		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_control_comp);
582 
583 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
584 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
585 
586 	uvc_streaming_header = mem;
587 	UVC_COPY_DESCRIPTORS(mem, dst,
588 		(const struct usb_descriptor_header**)uvc_streaming_cls);
589 	uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
590 	uvc_streaming_header->bEndpointAddress = uvc->video.ep->address;
591 
592 	UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
593 
594 	*dst = NULL;
595 	return hdr;
596 }
597 
598 static int
599 uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
600 {
601 	struct usb_composite_dev *cdev = c->cdev;
602 	struct uvc_device *uvc = to_uvc(f);
603 	struct usb_string *us;
604 	unsigned int max_packet_mult;
605 	unsigned int max_packet_size;
606 	struct usb_ep *ep;
607 	struct f_uvc_opts *opts;
608 	int ret = -EINVAL;
609 
610 	INFO(cdev, "uvc_function_bind\n");
611 
612 	opts = fi_to_f_uvc_opts(f->fi);
613 	/* Sanity check the streaming endpoint module parameters.
614 	 */
615 	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
616 	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
617 	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
618 
619 	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
620 	 * module parameters.
621 	 *
622 	 * NOTE: We assume that the user knows what they are doing and won't
623 	 * give parameters that their UDC doesn't support.
624 	 */
625 	if (opts->streaming_maxpacket <= 1024) {
626 		max_packet_mult = 1;
627 		max_packet_size = opts->streaming_maxpacket;
628 	} else if (opts->streaming_maxpacket <= 2048) {
629 		max_packet_mult = 2;
630 		max_packet_size = opts->streaming_maxpacket / 2;
631 	} else {
632 		max_packet_mult = 3;
633 		max_packet_size = opts->streaming_maxpacket / 3;
634 	}
635 
636 	uvc_fs_streaming_ep.wMaxPacketSize =
637 		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
638 	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
639 
640 	uvc_hs_streaming_ep.wMaxPacketSize =
641 		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
642 	uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
643 
644 	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
645 	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
646 	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
647 	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
648 	uvc_ss_streaming_comp.wBytesPerInterval =
649 		cpu_to_le16(max_packet_size * max_packet_mult *
650 			    opts->streaming_maxburst);
651 
652 	/* Allocate endpoints. */
653 	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
654 	if (!ep) {
655 		INFO(cdev, "Unable to allocate control EP\n");
656 		goto error;
657 	}
658 	uvc->control_ep = ep;
659 	ep->driver_data = uvc;
660 
661 	if (gadget_is_superspeed(c->cdev->gadget))
662 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
663 					  &uvc_ss_streaming_comp);
664 	else if (gadget_is_dualspeed(cdev->gadget))
665 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
666 	else
667 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
668 
669 	if (!ep) {
670 		INFO(cdev, "Unable to allocate streaming EP\n");
671 		goto error;
672 	}
673 	uvc->video.ep = ep;
674 	ep->driver_data = uvc;
675 
676 	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
677 	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
678 	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;
679 
680 	us = usb_gstrings_attach(cdev, uvc_function_strings,
681 				 ARRAY_SIZE(uvc_en_us_strings));
682 	if (IS_ERR(us)) {
683 		ret = PTR_ERR(us);
684 		goto error;
685 	}
686 	uvc_iad.iFunction = us[UVC_STRING_CONTROL_IDX].id;
687 	uvc_control_intf.iInterface = us[UVC_STRING_CONTROL_IDX].id;
688 	ret = us[UVC_STRING_STREAMING_IDX].id;
689 	uvc_streaming_intf_alt0.iInterface = ret;
690 	uvc_streaming_intf_alt1.iInterface = ret;
691 
692 	/* Allocate interface IDs. */
693 	if ((ret = usb_interface_id(c, f)) < 0)
694 		goto error;
695 	uvc_iad.bFirstInterface = ret;
696 	uvc_control_intf.bInterfaceNumber = ret;
697 	uvc->control_intf = ret;
698 
699 	if ((ret = usb_interface_id(c, f)) < 0)
700 		goto error;
701 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
702 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
703 	uvc->streaming_intf = ret;
704 
705 	/* Copy descriptors */
706 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
707 	if (IS_ERR(f->fs_descriptors)) {
708 		ret = PTR_ERR(f->fs_descriptors);
709 		f->fs_descriptors = NULL;
710 		goto error;
711 	}
712 	if (gadget_is_dualspeed(cdev->gadget)) {
713 		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
714 		if (IS_ERR(f->hs_descriptors)) {
715 			ret = PTR_ERR(f->hs_descriptors);
716 			f->hs_descriptors = NULL;
717 			goto error;
718 		}
719 	}
720 	if (gadget_is_superspeed(c->cdev->gadget)) {
721 		f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);
722 		if (IS_ERR(f->ss_descriptors)) {
723 			ret = PTR_ERR(f->ss_descriptors);
724 			f->ss_descriptors = NULL;
725 			goto error;
726 		}
727 	}
728 
729 	/* Preallocate control endpoint request. */
730 	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
731 	uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
732 	if (uvc->control_req == NULL || uvc->control_buf == NULL) {
733 		ret = -ENOMEM;
734 		goto error;
735 	}
736 
737 	uvc->control_req->buf = uvc->control_buf;
738 	uvc->control_req->complete = uvc_function_ep0_complete;
739 	uvc->control_req->context = uvc;
740 
741 	/* Avoid letting this gadget enumerate until the userspace server is
742 	 * active.
743 	 */
744 	if ((ret = usb_function_deactivate(f)) < 0)
745 		goto error;
746 
747 	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
748 		printk(KERN_INFO "v4l2_device_register failed\n");
749 		goto error;
750 	}
751 
752 	/* Initialise video. */
753 	ret = uvcg_video_init(&uvc->video);
754 	if (ret < 0)
755 		goto error;
756 
757 	/* Register a V4L2 device. */
758 	ret = uvc_register_video(uvc);
759 	if (ret < 0) {
760 		printk(KERN_INFO "Unable to register video device\n");
761 		goto error;
762 	}
763 
764 	return 0;
765 
766 error:
767 	v4l2_device_unregister(&uvc->v4l2_dev);
768 	if (uvc->vdev)
769 		video_device_release(uvc->vdev);
770 
771 	if (uvc->control_ep)
772 		uvc->control_ep->driver_data = NULL;
773 	if (uvc->video.ep)
774 		uvc->video.ep->driver_data = NULL;
775 
776 	if (uvc->control_req)
777 		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
778 	kfree(uvc->control_buf);
779 
780 	usb_free_all_descriptors(f);
781 	return ret;
782 }
783 
784 /* --------------------------------------------------------------------------
785  * USB gadget function
786  */
787 
788 static void uvc_free_inst(struct usb_function_instance *f)
789 {
790 	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f);
791 
792 	mutex_destroy(&opts->lock);
793 	kfree(opts);
794 }
795 
796 static struct usb_function_instance *uvc_alloc_inst(void)
797 {
798 	struct f_uvc_opts *opts;
799 	struct uvc_camera_terminal_descriptor *cd;
800 	struct uvc_processing_unit_descriptor *pd;
801 	struct uvc_output_terminal_descriptor *od;
802 	struct uvc_color_matching_descriptor *md;
803 	struct uvc_descriptor_header **ctl_cls;
804 
805 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
806 	if (!opts)
807 		return ERR_PTR(-ENOMEM);
808 	opts->func_inst.free_func_inst = uvc_free_inst;
809 	mutex_init(&opts->lock);
810 
811 	cd = &opts->uvc_camera_terminal;
812 	cd->bLength			= UVC_DT_CAMERA_TERMINAL_SIZE(3);
813 	cd->bDescriptorType		= USB_DT_CS_INTERFACE;
814 	cd->bDescriptorSubType		= UVC_VC_INPUT_TERMINAL;
815 	cd->bTerminalID			= 1;
816 	cd->wTerminalType		= cpu_to_le16(0x0201);
817 	cd->bAssocTerminal		= 0;
818 	cd->iTerminal			= 0;
819 	cd->wObjectiveFocalLengthMin	= cpu_to_le16(0);
820 	cd->wObjectiveFocalLengthMax	= cpu_to_le16(0);
821 	cd->wOcularFocalLength		= cpu_to_le16(0);
822 	cd->bControlSize		= 3;
823 	cd->bmControls[0]		= 2;
824 	cd->bmControls[1]		= 0;
825 	cd->bmControls[2]		= 0;
826 
827 	pd = &opts->uvc_processing;
828 	pd->bLength			= UVC_DT_PROCESSING_UNIT_SIZE(2);
829 	pd->bDescriptorType		= USB_DT_CS_INTERFACE;
830 	pd->bDescriptorSubType		= UVC_VC_PROCESSING_UNIT;
831 	pd->bUnitID			= 2;
832 	pd->bSourceID			= 1;
833 	pd->wMaxMultiplier		= cpu_to_le16(16*1024);
834 	pd->bControlSize		= 2;
835 	pd->bmControls[0]		= 1;
836 	pd->bmControls[1]		= 0;
837 	pd->iProcessing			= 0;
838 
839 	od = &opts->uvc_output_terminal;
840 	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;
841 	od->bDescriptorType		= USB_DT_CS_INTERFACE;
842 	od->bDescriptorSubType		= UVC_VC_OUTPUT_TERMINAL;
843 	od->bTerminalID			= 3;
844 	od->wTerminalType		= cpu_to_le16(0x0101);
845 	od->bAssocTerminal		= 0;
846 	od->bSourceID			= 2;
847 	od->iTerminal			= 0;
848 
849 	md = &opts->uvc_color_matching;
850 	md->bLength			= UVC_DT_COLOR_MATCHING_SIZE;
851 	md->bDescriptorType		= USB_DT_CS_INTERFACE;
852 	md->bDescriptorSubType		= UVC_VS_COLORFORMAT;
853 	md->bColorPrimaries		= 1;
854 	md->bTransferCharacteristics	= 1;
855 	md->bMatrixCoefficients		= 4;
856 
857 	/* Prepare fs control class descriptors for configfs-based gadgets */
858 	ctl_cls = opts->uvc_fs_control_cls;
859 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
860 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
861 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
862 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
863 	ctl_cls[4] = NULL;	/* NULL-terminate */
864 	opts->fs_control =
865 		(const struct uvc_descriptor_header * const *)ctl_cls;
866 
867 	/* Prepare hs control class descriptors for configfs-based gadgets */
868 	ctl_cls = opts->uvc_ss_control_cls;
869 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
870 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
871 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
872 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
873 	ctl_cls[4] = NULL;	/* NULL-terminate */
874 	opts->ss_control =
875 		(const struct uvc_descriptor_header * const *)ctl_cls;
876 
877 	opts->streaming_interval = 1;
878 	opts->streaming_maxpacket = 1024;
879 
880 	uvcg_attach_configfs(opts);
881 	return &opts->func_inst;
882 }
883 
884 static void uvc_free(struct usb_function *f)
885 {
886 	struct uvc_device *uvc = to_uvc(f);
887 	struct f_uvc_opts *opts = container_of(f->fi, struct f_uvc_opts,
888 					       func_inst);
889 	--opts->refcnt;
890 	kfree(uvc);
891 }
892 
893 static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
894 {
895 	struct usb_composite_dev *cdev = c->cdev;
896 	struct uvc_device *uvc = to_uvc(f);
897 
898 	INFO(cdev, "%s\n", __func__);
899 
900 	video_unregister_device(uvc->vdev);
901 	v4l2_device_unregister(&uvc->v4l2_dev);
902 	uvc->control_ep->driver_data = NULL;
903 	uvc->video.ep->driver_data = NULL;
904 
905 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
906 	kfree(uvc->control_buf);
907 
908 	usb_free_all_descriptors(f);
909 }
910 
911 static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
912 {
913 	struct uvc_device *uvc;
914 	struct f_uvc_opts *opts;
915 	struct uvc_descriptor_header **strm_cls;
916 
917 	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
918 	if (uvc == NULL)
919 		return ERR_PTR(-ENOMEM);
920 
921 	uvc->state = UVC_STATE_DISCONNECTED;
922 	opts = fi_to_f_uvc_opts(fi);
923 
924 	mutex_lock(&opts->lock);
925 	if (opts->uvc_fs_streaming_cls) {
926 		strm_cls = opts->uvc_fs_streaming_cls;
927 		opts->fs_streaming =
928 			(const struct uvc_descriptor_header * const *)strm_cls;
929 	}
930 	if (opts->uvc_hs_streaming_cls) {
931 		strm_cls = opts->uvc_hs_streaming_cls;
932 		opts->hs_streaming =
933 			(const struct uvc_descriptor_header * const *)strm_cls;
934 	}
935 	if (opts->uvc_ss_streaming_cls) {
936 		strm_cls = opts->uvc_ss_streaming_cls;
937 		opts->ss_streaming =
938 			(const struct uvc_descriptor_header * const *)strm_cls;
939 	}
940 
941 	uvc->desc.fs_control = opts->fs_control;
942 	uvc->desc.ss_control = opts->ss_control;
943 	uvc->desc.fs_streaming = opts->fs_streaming;
944 	uvc->desc.hs_streaming = opts->hs_streaming;
945 	uvc->desc.ss_streaming = opts->ss_streaming;
946 	++opts->refcnt;
947 	mutex_unlock(&opts->lock);
948 
949 	/* Register the function. */
950 	uvc->func.name = "uvc";
951 	uvc->func.bind = uvc_function_bind;
952 	uvc->func.unbind = uvc_unbind;
953 	uvc->func.get_alt = uvc_function_get_alt;
954 	uvc->func.set_alt = uvc_function_set_alt;
955 	uvc->func.disable = uvc_function_disable;
956 	uvc->func.setup = uvc_function_setup;
957 	uvc->func.free_func = uvc_free;
958 
959 	return &uvc->func;
960 }
961 
962 DECLARE_USB_FUNCTION_INIT(uvc, uvc_alloc_inst, uvc_alloc);
963 MODULE_LICENSE("GPL");
964 MODULE_AUTHOR("Laurent Pinchart");
965