1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *	uvc_gadget.c  --  USB Video Class Gadget driver
4  *
5  *	Copyright (C) 2009-2010
6  *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/fs.h>
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 #include <linux/string.h>
17 #include <linux/usb/ch9.h>
18 #include <linux/usb/gadget.h>
19 #include <linux/usb/video.h>
20 #include <linux/vmalloc.h>
21 #include <linux/wait.h>
22 
23 #include <media/v4l2-dev.h>
24 #include <media/v4l2-event.h>
25 
26 #include "u_uvc.h"
27 #include "uvc.h"
28 #include "uvc_configfs.h"
29 #include "uvc_v4l2.h"
30 #include "uvc_video.h"
31 
32 unsigned int uvc_gadget_trace_param;
33 
34 /* --------------------------------------------------------------------------
35  * Function descriptors
36  */
37 
38 /* string IDs are assigned dynamically */
39 
40 #define UVC_STRING_CONTROL_IDX			0
41 #define UVC_STRING_STREAMING_IDX		1
42 
43 static struct usb_string uvc_en_us_strings[] = {
44 	[UVC_STRING_CONTROL_IDX].s = "UVC Camera",
45 	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
46 	{  }
47 };
48 
49 static struct usb_gadget_strings uvc_stringtab = {
50 	.language = 0x0409,	/* en-us */
51 	.strings = uvc_en_us_strings,
52 };
53 
54 static struct usb_gadget_strings *uvc_function_strings[] = {
55 	&uvc_stringtab,
56 	NULL,
57 };
58 
59 #define UVC_INTF_VIDEO_CONTROL			0
60 #define UVC_INTF_VIDEO_STREAMING		1
61 
62 #define UVC_STATUS_MAX_PACKET_SIZE		16	/* 16 bytes status */
63 
64 static struct usb_interface_assoc_descriptor uvc_iad = {
65 	.bLength		= sizeof(uvc_iad),
66 	.bDescriptorType	= USB_DT_INTERFACE_ASSOCIATION,
67 	.bFirstInterface	= 0,
68 	.bInterfaceCount	= 2,
69 	.bFunctionClass		= USB_CLASS_VIDEO,
70 	.bFunctionSubClass	= UVC_SC_VIDEO_INTERFACE_COLLECTION,
71 	.bFunctionProtocol	= 0x00,
72 	.iFunction		= 0,
73 };
74 
75 static struct usb_interface_descriptor uvc_control_intf = {
76 	.bLength		= USB_DT_INTERFACE_SIZE,
77 	.bDescriptorType	= USB_DT_INTERFACE,
78 	.bInterfaceNumber	= UVC_INTF_VIDEO_CONTROL,
79 	.bAlternateSetting	= 0,
80 	.bNumEndpoints		= 1,
81 	.bInterfaceClass	= USB_CLASS_VIDEO,
82 	.bInterfaceSubClass	= UVC_SC_VIDEOCONTROL,
83 	.bInterfaceProtocol	= 0x00,
84 	.iInterface		= 0,
85 };
86 
87 static struct usb_endpoint_descriptor uvc_control_ep = {
88 	.bLength		= USB_DT_ENDPOINT_SIZE,
89 	.bDescriptorType	= USB_DT_ENDPOINT,
90 	.bEndpointAddress	= USB_DIR_IN,
91 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
92 	.wMaxPacketSize		= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
93 	.bInterval		= 8,
94 };
95 
96 static struct usb_ss_ep_comp_descriptor uvc_ss_control_comp = {
97 	.bLength		= sizeof(uvc_ss_control_comp),
98 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
99 	/* The following 3 values can be tweaked if necessary. */
100 	.bMaxBurst		= 0,
101 	.bmAttributes		= 0,
102 	.wBytesPerInterval	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
103 };
104 
105 static struct uvc_control_endpoint_descriptor uvc_control_cs_ep = {
106 	.bLength		= UVC_DT_CONTROL_ENDPOINT_SIZE,
107 	.bDescriptorType	= USB_DT_CS_ENDPOINT,
108 	.bDescriptorSubType	= UVC_EP_INTERRUPT,
109 	.wMaxTransferSize	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
110 };
111 
112 static struct usb_interface_descriptor uvc_streaming_intf_alt0 = {
113 	.bLength		= USB_DT_INTERFACE_SIZE,
114 	.bDescriptorType	= USB_DT_INTERFACE,
115 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
116 	.bAlternateSetting	= 0,
117 	.bNumEndpoints		= 0,
118 	.bInterfaceClass	= USB_CLASS_VIDEO,
119 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
120 	.bInterfaceProtocol	= 0x00,
121 	.iInterface		= 0,
122 };
123 
124 static struct usb_interface_descriptor uvc_streaming_intf_alt1 = {
125 	.bLength		= USB_DT_INTERFACE_SIZE,
126 	.bDescriptorType	= USB_DT_INTERFACE,
127 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
128 	.bAlternateSetting	= 1,
129 	.bNumEndpoints		= 1,
130 	.bInterfaceClass	= USB_CLASS_VIDEO,
131 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
132 	.bInterfaceProtocol	= 0x00,
133 	.iInterface		= 0,
134 };
135 
136 static struct usb_endpoint_descriptor uvc_fs_streaming_ep = {
137 	.bLength		= USB_DT_ENDPOINT_SIZE,
138 	.bDescriptorType	= USB_DT_ENDPOINT,
139 	.bEndpointAddress	= USB_DIR_IN,
140 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
141 				| USB_ENDPOINT_XFER_ISOC,
142 	/* The wMaxPacketSize and bInterval values will be initialized from
143 	 * module parameters.
144 	 */
145 };
146 
147 static struct usb_endpoint_descriptor uvc_hs_streaming_ep = {
148 	.bLength		= USB_DT_ENDPOINT_SIZE,
149 	.bDescriptorType	= USB_DT_ENDPOINT,
150 	.bEndpointAddress	= USB_DIR_IN,
151 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
152 				| USB_ENDPOINT_XFER_ISOC,
153 	/* The wMaxPacketSize and bInterval values will be initialized from
154 	 * module parameters.
155 	 */
156 };
157 
158 static struct usb_endpoint_descriptor uvc_ss_streaming_ep = {
159 	.bLength		= USB_DT_ENDPOINT_SIZE,
160 	.bDescriptorType	= USB_DT_ENDPOINT,
161 
162 	.bEndpointAddress	= USB_DIR_IN,
163 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
164 				| USB_ENDPOINT_XFER_ISOC,
165 	/* The wMaxPacketSize and bInterval values will be initialized from
166 	 * module parameters.
167 	 */
168 };
169 
170 static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
171 	.bLength		= sizeof(uvc_ss_streaming_comp),
172 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
173 	/* The bMaxBurst, bmAttributes and wBytesPerInterval values will be
174 	 * initialized from module parameters.
175 	 */
176 };
177 
178 static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
179 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
180 	(struct usb_descriptor_header *) &uvc_fs_streaming_ep,
181 	NULL,
182 };
183 
184 static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
185 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
186 	(struct usb_descriptor_header *) &uvc_hs_streaming_ep,
187 	NULL,
188 };
189 
190 static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
191 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
192 	(struct usb_descriptor_header *) &uvc_ss_streaming_ep,
193 	(struct usb_descriptor_header *) &uvc_ss_streaming_comp,
194 	NULL,
195 };
196 
197 void uvc_set_trace_param(unsigned int trace)
198 {
199 	uvc_gadget_trace_param = trace;
200 }
201 EXPORT_SYMBOL(uvc_set_trace_param);
202 
203 /* --------------------------------------------------------------------------
204  * Control requests
205  */
206 
207 static void
208 uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
209 {
210 	struct uvc_device *uvc = req->context;
211 	struct v4l2_event v4l2_event;
212 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
213 
214 	if (uvc->event_setup_out) {
215 		uvc->event_setup_out = 0;
216 
217 		memset(&v4l2_event, 0, sizeof(v4l2_event));
218 		v4l2_event.type = UVC_EVENT_DATA;
219 		uvc_event->data.length = req->actual;
220 		memcpy(&uvc_event->data.data, req->buf, req->actual);
221 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
222 	}
223 }
224 
225 static int
226 uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
227 {
228 	struct uvc_device *uvc = to_uvc(f);
229 	struct v4l2_event v4l2_event;
230 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
231 
232 	/* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
233 	 *	ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
234 	 *	le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
235 	 */
236 
237 	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
238 		INFO(f->config->cdev, "invalid request type\n");
239 		return -EINVAL;
240 	}
241 
242 	/* Stall too big requests. */
243 	if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
244 		return -EINVAL;
245 
246 	/* Tell the complete callback to generate an event for the next request
247 	 * that will be enqueued by UVCIOC_SEND_RESPONSE.
248 	 */
249 	uvc->event_setup_out = !(ctrl->bRequestType & USB_DIR_IN);
250 	uvc->event_length = le16_to_cpu(ctrl->wLength);
251 
252 	memset(&v4l2_event, 0, sizeof(v4l2_event));
253 	v4l2_event.type = UVC_EVENT_SETUP;
254 	memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
255 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
256 
257 	return 0;
258 }
259 
260 void uvc_function_setup_continue(struct uvc_device *uvc)
261 {
262 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
263 
264 	usb_composite_setup_continue(cdev);
265 }
266 
267 static int
268 uvc_function_get_alt(struct usb_function *f, unsigned interface)
269 {
270 	struct uvc_device *uvc = to_uvc(f);
271 
272 	INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);
273 
274 	if (interface == uvc->control_intf)
275 		return 0;
276 	else if (interface != uvc->streaming_intf)
277 		return -EINVAL;
278 	else
279 		return uvc->video.ep->enabled ? 1 : 0;
280 }
281 
282 static int
283 uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
284 {
285 	struct uvc_device *uvc = to_uvc(f);
286 	struct usb_composite_dev *cdev = f->config->cdev;
287 	struct v4l2_event v4l2_event;
288 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
289 	int ret;
290 
291 	INFO(cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);
292 
293 	if (interface == uvc->control_intf) {
294 		if (alt)
295 			return -EINVAL;
296 
297 		INFO(cdev, "reset UVC Control\n");
298 		usb_ep_disable(uvc->control_ep);
299 
300 		if (!uvc->control_ep->desc)
301 			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
302 				return -EINVAL;
303 
304 		usb_ep_enable(uvc->control_ep);
305 
306 		if (uvc->state == UVC_STATE_DISCONNECTED) {
307 			memset(&v4l2_event, 0, sizeof(v4l2_event));
308 			v4l2_event.type = UVC_EVENT_CONNECT;
309 			uvc_event->speed = cdev->gadget->speed;
310 			v4l2_event_queue(&uvc->vdev, &v4l2_event);
311 
312 			uvc->state = UVC_STATE_CONNECTED;
313 		}
314 
315 		return 0;
316 	}
317 
318 	if (interface != uvc->streaming_intf)
319 		return -EINVAL;
320 
321 	/* TODO
322 	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
323 		return alt ? -EINVAL : 0;
324 	*/
325 
326 	switch (alt) {
327 	case 0:
328 		if (uvc->state != UVC_STATE_STREAMING)
329 			return 0;
330 
331 		if (uvc->video.ep)
332 			usb_ep_disable(uvc->video.ep);
333 
334 		memset(&v4l2_event, 0, sizeof(v4l2_event));
335 		v4l2_event.type = UVC_EVENT_STREAMOFF;
336 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
337 
338 		uvc->state = UVC_STATE_CONNECTED;
339 		return 0;
340 
341 	case 1:
342 		if (uvc->state != UVC_STATE_CONNECTED)
343 			return 0;
344 
345 		if (!uvc->video.ep)
346 			return -EINVAL;
347 
348 		INFO(cdev, "reset UVC\n");
349 		usb_ep_disable(uvc->video.ep);
350 
351 		ret = config_ep_by_speed(f->config->cdev->gadget,
352 				&(uvc->func), uvc->video.ep);
353 		if (ret)
354 			return ret;
355 		usb_ep_enable(uvc->video.ep);
356 
357 		memset(&v4l2_event, 0, sizeof(v4l2_event));
358 		v4l2_event.type = UVC_EVENT_STREAMON;
359 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
360 		return USB_GADGET_DELAYED_STATUS;
361 
362 	default:
363 		return -EINVAL;
364 	}
365 }
366 
367 static void
368 uvc_function_disable(struct usb_function *f)
369 {
370 	struct uvc_device *uvc = to_uvc(f);
371 	struct v4l2_event v4l2_event;
372 
373 	INFO(f->config->cdev, "uvc_function_disable\n");
374 
375 	memset(&v4l2_event, 0, sizeof(v4l2_event));
376 	v4l2_event.type = UVC_EVENT_DISCONNECT;
377 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
378 
379 	uvc->state = UVC_STATE_DISCONNECTED;
380 
381 	usb_ep_disable(uvc->video.ep);
382 	usb_ep_disable(uvc->control_ep);
383 }
384 
385 /* --------------------------------------------------------------------------
386  * Connection / disconnection
387  */
388 
389 void
390 uvc_function_connect(struct uvc_device *uvc)
391 {
392 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
393 	int ret;
394 
395 	if ((ret = usb_function_activate(&uvc->func)) < 0)
396 		INFO(cdev, "UVC connect failed with %d\n", ret);
397 }
398 
399 void
400 uvc_function_disconnect(struct uvc_device *uvc)
401 {
402 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
403 	int ret;
404 
405 	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
406 		INFO(cdev, "UVC disconnect failed with %d\n", ret);
407 }
408 
409 /* --------------------------------------------------------------------------
410  * USB probe and disconnect
411  */
412 
413 static int
414 uvc_register_video(struct uvc_device *uvc)
415 {
416 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
417 
418 	/* TODO reference counting. */
419 	uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
420 	uvc->vdev.fops = &uvc_v4l2_fops;
421 	uvc->vdev.ioctl_ops = &uvc_v4l2_ioctl_ops;
422 	uvc->vdev.release = video_device_release_empty;
423 	uvc->vdev.vfl_dir = VFL_DIR_TX;
424 	uvc->vdev.lock = &uvc->video.mutex;
425 	strlcpy(uvc->vdev.name, cdev->gadget->name, sizeof(uvc->vdev.name));
426 
427 	video_set_drvdata(&uvc->vdev, uvc);
428 
429 	return video_register_device(&uvc->vdev, VFL_TYPE_GRABBER, -1);
430 }
431 
432 #define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
433 	do { \
434 		memcpy(mem, desc, (desc)->bLength); \
435 		*(dst)++ = mem; \
436 		mem += (desc)->bLength; \
437 	} while (0);
438 
439 #define UVC_COPY_DESCRIPTORS(mem, dst, src) \
440 	do { \
441 		const struct usb_descriptor_header * const *__src; \
442 		for (__src = src; *__src; ++__src) { \
443 			memcpy(mem, *__src, (*__src)->bLength); \
444 			*dst++ = mem; \
445 			mem += (*__src)->bLength; \
446 		} \
447 	} while (0)
448 
449 static struct usb_descriptor_header **
450 uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
451 {
452 	struct uvc_input_header_descriptor *uvc_streaming_header;
453 	struct uvc_header_descriptor *uvc_control_header;
454 	const struct uvc_descriptor_header * const *uvc_control_desc;
455 	const struct uvc_descriptor_header * const *uvc_streaming_cls;
456 	const struct usb_descriptor_header * const *uvc_streaming_std;
457 	const struct usb_descriptor_header * const *src;
458 	struct usb_descriptor_header **dst;
459 	struct usb_descriptor_header **hdr;
460 	unsigned int control_size;
461 	unsigned int streaming_size;
462 	unsigned int n_desc;
463 	unsigned int bytes;
464 	void *mem;
465 
466 	switch (speed) {
467 	case USB_SPEED_SUPER:
468 		uvc_control_desc = uvc->desc.ss_control;
469 		uvc_streaming_cls = uvc->desc.ss_streaming;
470 		uvc_streaming_std = uvc_ss_streaming;
471 		break;
472 
473 	case USB_SPEED_HIGH:
474 		uvc_control_desc = uvc->desc.fs_control;
475 		uvc_streaming_cls = uvc->desc.hs_streaming;
476 		uvc_streaming_std = uvc_hs_streaming;
477 		break;
478 
479 	case USB_SPEED_FULL:
480 	default:
481 		uvc_control_desc = uvc->desc.fs_control;
482 		uvc_streaming_cls = uvc->desc.fs_streaming;
483 		uvc_streaming_std = uvc_fs_streaming;
484 		break;
485 	}
486 
487 	if (!uvc_control_desc || !uvc_streaming_cls)
488 		return ERR_PTR(-ENODEV);
489 
490 	/* Descriptors layout
491 	 *
492 	 * uvc_iad
493 	 * uvc_control_intf
494 	 * Class-specific UVC control descriptors
495 	 * uvc_control_ep
496 	 * uvc_control_cs_ep
497 	 * uvc_ss_control_comp (for SS only)
498 	 * uvc_streaming_intf_alt0
499 	 * Class-specific UVC streaming descriptors
500 	 * uvc_{fs|hs}_streaming
501 	 */
502 
503 	/* Count descriptors and compute their size. */
504 	control_size = 0;
505 	streaming_size = 0;
506 	bytes = uvc_iad.bLength + uvc_control_intf.bLength
507 	      + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
508 	      + uvc_streaming_intf_alt0.bLength;
509 
510 	if (speed == USB_SPEED_SUPER) {
511 		bytes += uvc_ss_control_comp.bLength;
512 		n_desc = 6;
513 	} else {
514 		n_desc = 5;
515 	}
516 
517 	for (src = (const struct usb_descriptor_header **)uvc_control_desc;
518 	     *src; ++src) {
519 		control_size += (*src)->bLength;
520 		bytes += (*src)->bLength;
521 		n_desc++;
522 	}
523 	for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
524 	     *src; ++src) {
525 		streaming_size += (*src)->bLength;
526 		bytes += (*src)->bLength;
527 		n_desc++;
528 	}
529 	for (src = uvc_streaming_std; *src; ++src) {
530 		bytes += (*src)->bLength;
531 		n_desc++;
532 	}
533 
534 	mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
535 	if (mem == NULL)
536 		return NULL;
537 
538 	hdr = mem;
539 	dst = mem;
540 	mem += (n_desc + 1) * sizeof(*src);
541 
542 	/* Copy the descriptors. */
543 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
544 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
545 
546 	uvc_control_header = mem;
547 	UVC_COPY_DESCRIPTORS(mem, dst,
548 		(const struct usb_descriptor_header **)uvc_control_desc);
549 	uvc_control_header->wTotalLength = cpu_to_le16(control_size);
550 	uvc_control_header->bInCollection = 1;
551 	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
552 
553 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
554 	if (speed == USB_SPEED_SUPER)
555 		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_control_comp);
556 
557 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
558 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
559 
560 	uvc_streaming_header = mem;
561 	UVC_COPY_DESCRIPTORS(mem, dst,
562 		(const struct usb_descriptor_header**)uvc_streaming_cls);
563 	uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
564 	uvc_streaming_header->bEndpointAddress = uvc->video.ep->address;
565 
566 	UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
567 
568 	*dst = NULL;
569 	return hdr;
570 }
571 
572 static int
573 uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
574 {
575 	struct usb_composite_dev *cdev = c->cdev;
576 	struct uvc_device *uvc = to_uvc(f);
577 	struct usb_string *us;
578 	unsigned int max_packet_mult;
579 	unsigned int max_packet_size;
580 	struct usb_ep *ep;
581 	struct f_uvc_opts *opts;
582 	int ret = -EINVAL;
583 
584 	INFO(cdev, "uvc_function_bind\n");
585 
586 	opts = fi_to_f_uvc_opts(f->fi);
587 	/* Sanity check the streaming endpoint module parameters.
588 	 */
589 	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
590 	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
591 	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
592 
593 	/* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
594 	if (opts->streaming_maxburst &&
595 	    (opts->streaming_maxpacket % 1024) != 0) {
596 		opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
597 		INFO(cdev, "overriding streaming_maxpacket to %d\n",
598 		     opts->streaming_maxpacket);
599 	}
600 
601 	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
602 	 * module parameters.
603 	 *
604 	 * NOTE: We assume that the user knows what they are doing and won't
605 	 * give parameters that their UDC doesn't support.
606 	 */
607 	if (opts->streaming_maxpacket <= 1024) {
608 		max_packet_mult = 1;
609 		max_packet_size = opts->streaming_maxpacket;
610 	} else if (opts->streaming_maxpacket <= 2048) {
611 		max_packet_mult = 2;
612 		max_packet_size = opts->streaming_maxpacket / 2;
613 	} else {
614 		max_packet_mult = 3;
615 		max_packet_size = opts->streaming_maxpacket / 3;
616 	}
617 
618 	uvc_fs_streaming_ep.wMaxPacketSize =
619 		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
620 	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
621 
622 	uvc_hs_streaming_ep.wMaxPacketSize =
623 		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
624 	uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
625 
626 	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
627 	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
628 	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
629 	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
630 	uvc_ss_streaming_comp.wBytesPerInterval =
631 		cpu_to_le16(max_packet_size * max_packet_mult *
632 			    (opts->streaming_maxburst + 1));
633 
634 	/* Allocate endpoints. */
635 	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
636 	if (!ep) {
637 		INFO(cdev, "Unable to allocate control EP\n");
638 		goto error;
639 	}
640 	uvc->control_ep = ep;
641 
642 	if (gadget_is_superspeed(c->cdev->gadget))
643 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
644 					  &uvc_ss_streaming_comp);
645 	else if (gadget_is_dualspeed(cdev->gadget))
646 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
647 	else
648 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
649 
650 	if (!ep) {
651 		INFO(cdev, "Unable to allocate streaming EP\n");
652 		goto error;
653 	}
654 	uvc->video.ep = ep;
655 
656 	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
657 	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
658 	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;
659 
660 	us = usb_gstrings_attach(cdev, uvc_function_strings,
661 				 ARRAY_SIZE(uvc_en_us_strings));
662 	if (IS_ERR(us)) {
663 		ret = PTR_ERR(us);
664 		goto error;
665 	}
666 	uvc_iad.iFunction = us[UVC_STRING_CONTROL_IDX].id;
667 	uvc_control_intf.iInterface = us[UVC_STRING_CONTROL_IDX].id;
668 	ret = us[UVC_STRING_STREAMING_IDX].id;
669 	uvc_streaming_intf_alt0.iInterface = ret;
670 	uvc_streaming_intf_alt1.iInterface = ret;
671 
672 	/* Allocate interface IDs. */
673 	if ((ret = usb_interface_id(c, f)) < 0)
674 		goto error;
675 	uvc_iad.bFirstInterface = ret;
676 	uvc_control_intf.bInterfaceNumber = ret;
677 	uvc->control_intf = ret;
678 
679 	if ((ret = usb_interface_id(c, f)) < 0)
680 		goto error;
681 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
682 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
683 	uvc->streaming_intf = ret;
684 
685 	/* Copy descriptors */
686 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
687 	if (IS_ERR(f->fs_descriptors)) {
688 		ret = PTR_ERR(f->fs_descriptors);
689 		f->fs_descriptors = NULL;
690 		goto error;
691 	}
692 	if (gadget_is_dualspeed(cdev->gadget)) {
693 		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
694 		if (IS_ERR(f->hs_descriptors)) {
695 			ret = PTR_ERR(f->hs_descriptors);
696 			f->hs_descriptors = NULL;
697 			goto error;
698 		}
699 	}
700 	if (gadget_is_superspeed(c->cdev->gadget)) {
701 		f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);
702 		if (IS_ERR(f->ss_descriptors)) {
703 			ret = PTR_ERR(f->ss_descriptors);
704 			f->ss_descriptors = NULL;
705 			goto error;
706 		}
707 	}
708 
709 	/* Preallocate control endpoint request. */
710 	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
711 	uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
712 	if (uvc->control_req == NULL || uvc->control_buf == NULL) {
713 		ret = -ENOMEM;
714 		goto error;
715 	}
716 
717 	uvc->control_req->buf = uvc->control_buf;
718 	uvc->control_req->complete = uvc_function_ep0_complete;
719 	uvc->control_req->context = uvc;
720 
721 	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
722 		printk(KERN_INFO "v4l2_device_register failed\n");
723 		goto error;
724 	}
725 
726 	/* Initialise video. */
727 	ret = uvcg_video_init(&uvc->video);
728 	if (ret < 0)
729 		goto error;
730 
731 	/* Register a V4L2 device. */
732 	ret = uvc_register_video(uvc);
733 	if (ret < 0) {
734 		printk(KERN_INFO "Unable to register video device\n");
735 		goto error;
736 	}
737 
738 	return 0;
739 
740 error:
741 	v4l2_device_unregister(&uvc->v4l2_dev);
742 
743 	if (uvc->control_req)
744 		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
745 	kfree(uvc->control_buf);
746 
747 	usb_free_all_descriptors(f);
748 	return ret;
749 }
750 
751 /* --------------------------------------------------------------------------
752  * USB gadget function
753  */
754 
755 static void uvc_free_inst(struct usb_function_instance *f)
756 {
757 	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f);
758 
759 	mutex_destroy(&opts->lock);
760 	kfree(opts);
761 }
762 
763 static struct usb_function_instance *uvc_alloc_inst(void)
764 {
765 	struct f_uvc_opts *opts;
766 	struct uvc_camera_terminal_descriptor *cd;
767 	struct uvc_processing_unit_descriptor *pd;
768 	struct uvc_output_terminal_descriptor *od;
769 	struct uvc_color_matching_descriptor *md;
770 	struct uvc_descriptor_header **ctl_cls;
771 
772 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
773 	if (!opts)
774 		return ERR_PTR(-ENOMEM);
775 	opts->func_inst.free_func_inst = uvc_free_inst;
776 	mutex_init(&opts->lock);
777 
778 	cd = &opts->uvc_camera_terminal;
779 	cd->bLength			= UVC_DT_CAMERA_TERMINAL_SIZE(3);
780 	cd->bDescriptorType		= USB_DT_CS_INTERFACE;
781 	cd->bDescriptorSubType		= UVC_VC_INPUT_TERMINAL;
782 	cd->bTerminalID			= 1;
783 	cd->wTerminalType		= cpu_to_le16(0x0201);
784 	cd->bAssocTerminal		= 0;
785 	cd->iTerminal			= 0;
786 	cd->wObjectiveFocalLengthMin	= cpu_to_le16(0);
787 	cd->wObjectiveFocalLengthMax	= cpu_to_le16(0);
788 	cd->wOcularFocalLength		= cpu_to_le16(0);
789 	cd->bControlSize		= 3;
790 	cd->bmControls[0]		= 2;
791 	cd->bmControls[1]		= 0;
792 	cd->bmControls[2]		= 0;
793 
794 	pd = &opts->uvc_processing;
795 	pd->bLength			= UVC_DT_PROCESSING_UNIT_SIZE(2);
796 	pd->bDescriptorType		= USB_DT_CS_INTERFACE;
797 	pd->bDescriptorSubType		= UVC_VC_PROCESSING_UNIT;
798 	pd->bUnitID			= 2;
799 	pd->bSourceID			= 1;
800 	pd->wMaxMultiplier		= cpu_to_le16(16*1024);
801 	pd->bControlSize		= 2;
802 	pd->bmControls[0]		= 1;
803 	pd->bmControls[1]		= 0;
804 	pd->iProcessing			= 0;
805 
806 	od = &opts->uvc_output_terminal;
807 	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;
808 	od->bDescriptorType		= USB_DT_CS_INTERFACE;
809 	od->bDescriptorSubType		= UVC_VC_OUTPUT_TERMINAL;
810 	od->bTerminalID			= 3;
811 	od->wTerminalType		= cpu_to_le16(0x0101);
812 	od->bAssocTerminal		= 0;
813 	od->bSourceID			= 2;
814 	od->iTerminal			= 0;
815 
816 	md = &opts->uvc_color_matching;
817 	md->bLength			= UVC_DT_COLOR_MATCHING_SIZE;
818 	md->bDescriptorType		= USB_DT_CS_INTERFACE;
819 	md->bDescriptorSubType		= UVC_VS_COLORFORMAT;
820 	md->bColorPrimaries		= 1;
821 	md->bTransferCharacteristics	= 1;
822 	md->bMatrixCoefficients		= 4;
823 
824 	/* Prepare fs control class descriptors for configfs-based gadgets */
825 	ctl_cls = opts->uvc_fs_control_cls;
826 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
827 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
828 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
829 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
830 	ctl_cls[4] = NULL;	/* NULL-terminate */
831 	opts->fs_control =
832 		(const struct uvc_descriptor_header * const *)ctl_cls;
833 
834 	/* Prepare hs control class descriptors for configfs-based gadgets */
835 	ctl_cls = opts->uvc_ss_control_cls;
836 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
837 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
838 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
839 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
840 	ctl_cls[4] = NULL;	/* NULL-terminate */
841 	opts->ss_control =
842 		(const struct uvc_descriptor_header * const *)ctl_cls;
843 
844 	opts->streaming_interval = 1;
845 	opts->streaming_maxpacket = 1024;
846 
847 	uvcg_attach_configfs(opts);
848 	return &opts->func_inst;
849 }
850 
851 static void uvc_free(struct usb_function *f)
852 {
853 	struct uvc_device *uvc = to_uvc(f);
854 	struct f_uvc_opts *opts = container_of(f->fi, struct f_uvc_opts,
855 					       func_inst);
856 	--opts->refcnt;
857 	kfree(uvc);
858 }
859 
860 static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
861 {
862 	struct usb_composite_dev *cdev = c->cdev;
863 	struct uvc_device *uvc = to_uvc(f);
864 
865 	INFO(cdev, "%s\n", __func__);
866 
867 	video_unregister_device(&uvc->vdev);
868 	v4l2_device_unregister(&uvc->v4l2_dev);
869 
870 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
871 	kfree(uvc->control_buf);
872 
873 	usb_free_all_descriptors(f);
874 }
875 
876 static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
877 {
878 	struct uvc_device *uvc;
879 	struct f_uvc_opts *opts;
880 	struct uvc_descriptor_header **strm_cls;
881 
882 	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
883 	if (uvc == NULL)
884 		return ERR_PTR(-ENOMEM);
885 
886 	mutex_init(&uvc->video.mutex);
887 	uvc->state = UVC_STATE_DISCONNECTED;
888 	opts = fi_to_f_uvc_opts(fi);
889 
890 	mutex_lock(&opts->lock);
891 	if (opts->uvc_fs_streaming_cls) {
892 		strm_cls = opts->uvc_fs_streaming_cls;
893 		opts->fs_streaming =
894 			(const struct uvc_descriptor_header * const *)strm_cls;
895 	}
896 	if (opts->uvc_hs_streaming_cls) {
897 		strm_cls = opts->uvc_hs_streaming_cls;
898 		opts->hs_streaming =
899 			(const struct uvc_descriptor_header * const *)strm_cls;
900 	}
901 	if (opts->uvc_ss_streaming_cls) {
902 		strm_cls = opts->uvc_ss_streaming_cls;
903 		opts->ss_streaming =
904 			(const struct uvc_descriptor_header * const *)strm_cls;
905 	}
906 
907 	uvc->desc.fs_control = opts->fs_control;
908 	uvc->desc.ss_control = opts->ss_control;
909 	uvc->desc.fs_streaming = opts->fs_streaming;
910 	uvc->desc.hs_streaming = opts->hs_streaming;
911 	uvc->desc.ss_streaming = opts->ss_streaming;
912 	++opts->refcnt;
913 	mutex_unlock(&opts->lock);
914 
915 	/* Register the function. */
916 	uvc->func.name = "uvc";
917 	uvc->func.bind = uvc_function_bind;
918 	uvc->func.unbind = uvc_unbind;
919 	uvc->func.get_alt = uvc_function_get_alt;
920 	uvc->func.set_alt = uvc_function_set_alt;
921 	uvc->func.disable = uvc_function_disable;
922 	uvc->func.setup = uvc_function_setup;
923 	uvc->func.free_func = uvc_free;
924 	uvc->func.bind_deactivated = true;
925 
926 	return &uvc->func;
927 }
928 
929 DECLARE_USB_FUNCTION_INIT(uvc, uvc_alloc_inst, uvc_alloc);
930 MODULE_LICENSE("GPL");
931 MODULE_AUTHOR("Laurent Pinchart");
932