xref: /linux/drivers/usb/gadget/function/f_uvc.c (revision 4db102dcb0396a4ccf89b1eac0f4eb3fd167a080)
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/device.h>
10 #include <linux/errno.h>
11 #include <linux/fs.h>
12 #include <linux/kernel.h>
13 #include <linux/list.h>
14 #include <linux/module.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/g_uvc.h>
20 #include <linux/usb/video.h>
21 #include <linux/vmalloc.h>
22 #include <linux/wait.h>
23 
24 #include <media/v4l2-dev.h>
25 #include <media/v4l2-event.h>
26 
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 module_param_named(trace, uvc_gadget_trace_param, uint, 0644);
34 MODULE_PARM_DESC(trace, "Trace level bitmask");
35 
36 /* --------------------------------------------------------------------------
37  * Function descriptors
38  */
39 
40 /* string IDs are assigned dynamically */
41 
42 static struct usb_string uvc_en_us_strings[] = {
43 	/* [UVC_STRING_CONTROL_IDX].s = DYNAMIC, */
44 	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
45 	{  }
46 };
47 
48 static struct usb_gadget_strings uvc_stringtab = {
49 	.language = 0x0409,	/* en-us */
50 	.strings = uvc_en_us_strings,
51 };
52 
53 static struct usb_gadget_strings *uvc_function_strings[] = {
54 	&uvc_stringtab,
55 	NULL,
56 };
57 
58 #define UVC_INTF_VIDEO_CONTROL			0
59 #define UVC_INTF_VIDEO_STREAMING		1
60 
61 #define UVC_STATUS_MAX_PACKET_SIZE		16	/* 16 bytes status */
62 
63 static struct usb_interface_assoc_descriptor uvc_iad = {
64 	.bLength		= sizeof(uvc_iad),
65 	.bDescriptorType	= USB_DT_INTERFACE_ASSOCIATION,
66 	.bFirstInterface	= 0,
67 	.bInterfaceCount	= 2,
68 	.bFunctionClass		= USB_CLASS_VIDEO,
69 	.bFunctionSubClass	= UVC_SC_VIDEO_INTERFACE_COLLECTION,
70 	.bFunctionProtocol	= 0x00,
71 	.iFunction		= 0,
72 };
73 
74 static struct usb_interface_descriptor uvc_control_intf = {
75 	.bLength		= USB_DT_INTERFACE_SIZE,
76 	.bDescriptorType	= USB_DT_INTERFACE,
77 	.bInterfaceNumber	= UVC_INTF_VIDEO_CONTROL,
78 	.bAlternateSetting	= 0,
79 	.bNumEndpoints		= 0,
80 	.bInterfaceClass	= USB_CLASS_VIDEO,
81 	.bInterfaceSubClass	= UVC_SC_VIDEOCONTROL,
82 	.bInterfaceProtocol	= 0x00,
83 	.iInterface		= 0,
84 };
85 
86 static struct usb_endpoint_descriptor uvc_interrupt_ep = {
87 	.bLength		= USB_DT_ENDPOINT_SIZE,
88 	.bDescriptorType	= USB_DT_ENDPOINT,
89 	.bEndpointAddress	= USB_DIR_IN,
90 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
91 	.wMaxPacketSize		= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
92 	.bInterval		= 8,
93 };
94 
95 static struct usb_ss_ep_comp_descriptor uvc_ss_interrupt_comp = {
96 	.bLength		= sizeof(uvc_ss_interrupt_comp),
97 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
98 	/* The following 3 values can be tweaked if necessary. */
99 	.bMaxBurst		= 0,
100 	.bmAttributes		= 0,
101 	.wBytesPerInterval	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
102 };
103 
104 static struct uvc_control_endpoint_descriptor uvc_interrupt_cs_ep = {
105 	.bLength		= UVC_DT_CONTROL_ENDPOINT_SIZE,
106 	.bDescriptorType	= USB_DT_CS_ENDPOINT,
107 	.bDescriptorSubType	= UVC_EP_INTERRUPT,
108 	.wMaxTransferSize	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
109 };
110 
111 static struct usb_interface_descriptor uvc_streaming_intf_alt0 = {
112 	.bLength		= USB_DT_INTERFACE_SIZE,
113 	.bDescriptorType	= USB_DT_INTERFACE,
114 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
115 	.bAlternateSetting	= 0,
116 	.bNumEndpoints		= 0,
117 	.bInterfaceClass	= USB_CLASS_VIDEO,
118 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
119 	.bInterfaceProtocol	= 0x00,
120 	.iInterface		= 0,
121 };
122 
123 static struct usb_interface_descriptor uvc_streaming_intf_alt1 = {
124 	.bLength		= USB_DT_INTERFACE_SIZE,
125 	.bDescriptorType	= USB_DT_INTERFACE,
126 	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
127 	.bAlternateSetting	= 1,
128 	.bNumEndpoints		= 1,
129 	.bInterfaceClass	= USB_CLASS_VIDEO,
130 	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
131 	.bInterfaceProtocol	= 0x00,
132 	.iInterface		= 0,
133 };
134 
135 static struct usb_endpoint_descriptor uvc_fs_streaming_ep = {
136 	.bLength		= USB_DT_ENDPOINT_SIZE,
137 	.bDescriptorType	= USB_DT_ENDPOINT,
138 	.bEndpointAddress	= USB_DIR_IN,
139 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
140 				| USB_ENDPOINT_XFER_ISOC,
141 	/*
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 	/*
154 	 * The wMaxPacketSize and bInterval values will be initialized from
155 	 * module parameters.
156 	 */
157 };
158 
159 static struct usb_endpoint_descriptor uvc_ss_streaming_ep = {
160 	.bLength		= USB_DT_ENDPOINT_SIZE,
161 	.bDescriptorType	= USB_DT_ENDPOINT,
162 
163 	.bEndpointAddress	= USB_DIR_IN,
164 	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
165 				| USB_ENDPOINT_XFER_ISOC,
166 	/*
167 	 * The wMaxPacketSize and bInterval values will be initialized from
168 	 * module parameters.
169 	 */
170 };
171 
172 static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
173 	.bLength		= sizeof(uvc_ss_streaming_comp),
174 	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
175 	/*
176 	 * The bMaxBurst, bmAttributes and wBytesPerInterval values will be
177 	 * initialized from module parameters.
178 	 */
179 };
180 
181 static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
182 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
183 	(struct usb_descriptor_header *) &uvc_fs_streaming_ep,
184 	NULL,
185 };
186 
187 static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
188 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
189 	(struct usb_descriptor_header *) &uvc_hs_streaming_ep,
190 	NULL,
191 };
192 
193 static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
194 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
195 	(struct usb_descriptor_header *) &uvc_ss_streaming_ep,
196 	(struct usb_descriptor_header *) &uvc_ss_streaming_comp,
197 	NULL,
198 };
199 
200 /* --------------------------------------------------------------------------
201  * Control requests
202  */
203 
204 static void
205 uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
206 {
207 	struct uvc_device *uvc = req->context;
208 	struct v4l2_event v4l2_event;
209 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
210 
211 	if (uvc->event_setup_out) {
212 		uvc->event_setup_out = 0;
213 
214 		memset(&v4l2_event, 0, sizeof(v4l2_event));
215 		v4l2_event.type = UVC_EVENT_DATA;
216 		uvc_event->data.length = min_t(unsigned int, req->actual,
217 			sizeof(uvc_event->data.data));
218 		memcpy(&uvc_event->data.data, req->buf, uvc_event->data.length);
219 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
220 	}
221 }
222 
223 static int
224 uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
225 {
226 	struct uvc_device *uvc = to_uvc(f);
227 	struct v4l2_event v4l2_event;
228 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
229 	unsigned int interface = le16_to_cpu(ctrl->wIndex) & 0xff;
230 	struct usb_ctrlrequest *mctrl;
231 
232 	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
233 		uvcg_info(f, "invalid request type\n");
234 		return -EINVAL;
235 	}
236 
237 	/* Stall too big requests. */
238 	if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
239 		return -EINVAL;
240 
241 	/*
242 	 * Tell the complete callback to generate an event for the next request
243 	 * that will be enqueued by UVCIOC_SEND_RESPONSE.
244 	 */
245 	uvc->event_setup_out = !(ctrl->bRequestType & USB_DIR_IN);
246 	uvc->event_length = le16_to_cpu(ctrl->wLength);
247 
248 	memset(&v4l2_event, 0, sizeof(v4l2_event));
249 	v4l2_event.type = UVC_EVENT_SETUP;
250 	memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
251 
252 	/* check for the interface number, fixup the interface number in
253 	 * the ctrl request so the userspace doesn't have to bother with
254 	 * offset and configfs parsing
255 	 */
256 	mctrl = &uvc_event->req;
257 	mctrl->wIndex &= ~cpu_to_le16(0xff);
258 	if (interface == uvc->streaming_intf)
259 		mctrl->wIndex = cpu_to_le16(UVC_STRING_STREAMING_IDX);
260 
261 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
262 
263 	return 0;
264 }
265 
266 void uvc_function_setup_continue(struct uvc_device *uvc, int disable_ep)
267 {
268 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
269 
270 	if (disable_ep && uvc->video.ep)
271 		usb_ep_disable(uvc->video.ep);
272 
273 	usb_composite_setup_continue(cdev);
274 }
275 
276 static int
277 uvc_function_get_alt(struct usb_function *f, unsigned interface)
278 {
279 	struct uvc_device *uvc = to_uvc(f);
280 
281 	uvcg_info(f, "%s(%u)\n", __func__, interface);
282 
283 	if (interface == uvc->control_intf)
284 		return 0;
285 	else if (interface != uvc->streaming_intf)
286 		return -EINVAL;
287 	else
288 		return uvc->video.ep->enabled ? 1 : 0;
289 }
290 
291 static int
292 uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
293 {
294 	struct uvc_device *uvc = to_uvc(f);
295 	struct usb_composite_dev *cdev = f->config->cdev;
296 	struct v4l2_event v4l2_event;
297 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
298 	int ret;
299 
300 	uvcg_info(f, "%s(%u, %u)\n", __func__, interface, alt);
301 
302 	if (interface == uvc->control_intf) {
303 		if (alt)
304 			return -EINVAL;
305 
306 		if (uvc->enable_interrupt_ep) {
307 			uvcg_info(f, "reset UVC interrupt endpoint\n");
308 			usb_ep_disable(uvc->interrupt_ep);
309 
310 			if (!uvc->interrupt_ep->desc)
311 				if (config_ep_by_speed(cdev->gadget, f,
312 						       uvc->interrupt_ep))
313 					return -EINVAL;
314 
315 			usb_ep_enable(uvc->interrupt_ep);
316 		}
317 
318 		if (uvc->state == UVC_STATE_DISCONNECTED) {
319 			memset(&v4l2_event, 0, sizeof(v4l2_event));
320 			v4l2_event.type = UVC_EVENT_CONNECT;
321 			uvc_event->speed = cdev->gadget->speed;
322 			v4l2_event_queue(&uvc->vdev, &v4l2_event);
323 
324 			uvc->state = UVC_STATE_CONNECTED;
325 		}
326 
327 		return 0;
328 	}
329 
330 	if (interface != uvc->streaming_intf)
331 		return -EINVAL;
332 
333 	/* TODO
334 	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
335 		return alt ? -EINVAL : 0;
336 	*/
337 
338 	switch (alt) {
339 	case 0:
340 		if (uvc->state != UVC_STATE_STREAMING)
341 			return 0;
342 
343 		memset(&v4l2_event, 0, sizeof(v4l2_event));
344 		v4l2_event.type = UVC_EVENT_STREAMOFF;
345 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
346 
347 		return USB_GADGET_DELAYED_STATUS;
348 
349 	case 1:
350 		if (uvc->state != UVC_STATE_CONNECTED)
351 			return 0;
352 
353 		if (!uvc->video.ep)
354 			return -EINVAL;
355 
356 		uvcg_info(f, "reset UVC\n");
357 		usb_ep_disable(uvc->video.ep);
358 
359 		ret = config_ep_by_speed(f->config->cdev->gadget,
360 				&(uvc->func), uvc->video.ep);
361 		if (ret)
362 			return ret;
363 		usb_ep_enable(uvc->video.ep);
364 
365 		memset(&v4l2_event, 0, sizeof(v4l2_event));
366 		v4l2_event.type = UVC_EVENT_STREAMON;
367 		v4l2_event_queue(&uvc->vdev, &v4l2_event);
368 		return USB_GADGET_DELAYED_STATUS;
369 
370 	default:
371 		return -EINVAL;
372 	}
373 }
374 
375 static void
376 uvc_function_disable(struct usb_function *f)
377 {
378 	struct uvc_device *uvc = to_uvc(f);
379 	struct v4l2_event v4l2_event;
380 
381 	uvcg_info(f, "%s()\n", __func__);
382 
383 	memset(&v4l2_event, 0, sizeof(v4l2_event));
384 	v4l2_event.type = UVC_EVENT_DISCONNECT;
385 	v4l2_event_queue(&uvc->vdev, &v4l2_event);
386 
387 	uvc->state = UVC_STATE_DISCONNECTED;
388 
389 	usb_ep_disable(uvc->video.ep);
390 	if (uvc->enable_interrupt_ep)
391 		usb_ep_disable(uvc->interrupt_ep);
392 }
393 
394 /* --------------------------------------------------------------------------
395  * Connection / disconnection
396  */
397 
398 void
399 uvc_function_connect(struct uvc_device *uvc)
400 {
401 	int ret;
402 
403 	if ((ret = usb_function_activate(&uvc->func)) < 0)
404 		uvcg_info(&uvc->func, "UVC connect failed with %d\n", ret);
405 }
406 
407 void
408 uvc_function_disconnect(struct uvc_device *uvc)
409 {
410 	int ret;
411 
412 	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
413 		uvcg_info(&uvc->func, "UVC disconnect failed with %d\n", ret);
414 }
415 
416 /* --------------------------------------------------------------------------
417  * USB probe and disconnect
418  */
419 
420 static ssize_t function_name_show(struct device *dev,
421 				  struct device_attribute *attr, char *buf)
422 {
423 	struct uvc_device *uvc = dev_get_drvdata(dev);
424 
425 	return sprintf(buf, "%s\n", uvc->func.fi->group.cg_item.ci_name);
426 }
427 
428 static DEVICE_ATTR_RO(function_name);
429 
430 static int
431 uvc_register_video(struct uvc_device *uvc)
432 {
433 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
434 	int ret;
435 
436 	/* TODO reference counting. */
437 	memset(&uvc->vdev, 0, sizeof(uvc->vdev));
438 	uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
439 	uvc->vdev.v4l2_dev->dev = &cdev->gadget->dev;
440 	uvc->vdev.fops = &uvc_v4l2_fops;
441 	uvc->vdev.ioctl_ops = &uvc_v4l2_ioctl_ops;
442 	uvc->vdev.release = video_device_release_empty;
443 	uvc->vdev.vfl_dir = VFL_DIR_TX;
444 	uvc->vdev.lock = &uvc->video.mutex;
445 	uvc->vdev.device_caps = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
446 	strscpy(uvc->vdev.name, cdev->gadget->name, sizeof(uvc->vdev.name));
447 
448 	video_set_drvdata(&uvc->vdev, uvc);
449 
450 	ret = video_register_device(&uvc->vdev, VFL_TYPE_VIDEO, -1);
451 	if (ret < 0)
452 		return ret;
453 
454 	ret = device_create_file(&uvc->vdev.dev, &dev_attr_function_name);
455 	if (ret < 0) {
456 		video_unregister_device(&uvc->vdev);
457 		return ret;
458 	}
459 
460 	return 0;
461 }
462 
463 #define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
464 	do { \
465 		memcpy(mem, desc, (desc)->bLength); \
466 		*(dst)++ = mem; \
467 		mem += (desc)->bLength; \
468 	} while (0);
469 
470 #define UVC_COPY_DESCRIPTORS(mem, dst, src) \
471 	do { \
472 		const struct usb_descriptor_header * const *__src; \
473 		for (__src = src; *__src; ++__src) { \
474 			memcpy(mem, *__src, (*__src)->bLength); \
475 			*dst++ = mem; \
476 			mem += (*__src)->bLength; \
477 		} \
478 	} while (0)
479 
480 #define UVC_COPY_XU_DESCRIPTOR(mem, dst, desc)					\
481 	do {									\
482 		*(dst)++ = mem;							\
483 		memcpy(mem, desc, 22); /* bLength to bNrInPins */		\
484 		mem += 22;							\
485 										\
486 		memcpy(mem, (desc)->baSourceID, (desc)->bNrInPins);		\
487 		mem += (desc)->bNrInPins;					\
488 										\
489 		memcpy(mem, &(desc)->bControlSize, 1);				\
490 		mem++;								\
491 										\
492 		memcpy(mem, (desc)->bmControls, (desc)->bControlSize);		\
493 		mem += (desc)->bControlSize;					\
494 										\
495 		memcpy(mem, &(desc)->iExtension, 1);				\
496 		mem++;								\
497 	} while (0)
498 
499 static struct usb_descriptor_header **
500 uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
501 {
502 	struct uvc_input_header_descriptor *uvc_streaming_header;
503 	struct uvc_header_descriptor *uvc_control_header;
504 	const struct uvc_descriptor_header * const *uvc_control_desc;
505 	const struct uvc_descriptor_header * const *uvc_streaming_cls;
506 	const struct usb_descriptor_header * const *uvc_streaming_std;
507 	const struct usb_descriptor_header * const *src;
508 	struct usb_descriptor_header **dst;
509 	struct usb_descriptor_header **hdr;
510 	struct uvcg_extension *xu;
511 	unsigned int control_size;
512 	unsigned int streaming_size;
513 	unsigned int n_desc;
514 	unsigned int bytes;
515 	void *mem;
516 
517 	switch (speed) {
518 	case USB_SPEED_SUPER_PLUS:
519 	case USB_SPEED_SUPER:
520 		uvc_control_desc = uvc->desc.ss_control;
521 		uvc_streaming_cls = uvc->desc.ss_streaming;
522 		uvc_streaming_std = uvc_ss_streaming;
523 		break;
524 
525 	case USB_SPEED_HIGH:
526 		uvc_control_desc = uvc->desc.fs_control;
527 		uvc_streaming_cls = uvc->desc.hs_streaming;
528 		uvc_streaming_std = uvc_hs_streaming;
529 		break;
530 
531 	case USB_SPEED_FULL:
532 	default:
533 		uvc_control_desc = uvc->desc.fs_control;
534 		uvc_streaming_cls = uvc->desc.fs_streaming;
535 		uvc_streaming_std = uvc_fs_streaming;
536 		break;
537 	}
538 
539 	if (!uvc_control_desc || !uvc_streaming_cls)
540 		return ERR_PTR(-ENODEV);
541 
542 	/*
543 	 * Descriptors layout
544 	 *
545 	 * uvc_iad
546 	 * uvc_control_intf
547 	 * Class-specific UVC control descriptors
548 	 * uvc_interrupt_ep
549 	 * uvc_interrupt_cs_ep
550 	 * uvc_ss_interrupt_comp (for SS only)
551 	 * uvc_streaming_intf_alt0
552 	 * Class-specific UVC streaming descriptors
553 	 * uvc_{fs|hs}_streaming
554 	 */
555 
556 	/* Count descriptors and compute their size. */
557 	control_size = 0;
558 	streaming_size = 0;
559 	bytes = uvc_iad.bLength + uvc_control_intf.bLength
560 	      + uvc_streaming_intf_alt0.bLength;
561 
562 	n_desc = 3;
563 	if (uvc->enable_interrupt_ep) {
564 		bytes += uvc_interrupt_ep.bLength + uvc_interrupt_cs_ep.bLength;
565 		n_desc += 2;
566 
567 		if (speed == USB_SPEED_SUPER ||
568 		    speed == USB_SPEED_SUPER_PLUS) {
569 			bytes += uvc_ss_interrupt_comp.bLength;
570 			n_desc += 1;
571 		}
572 	}
573 
574 	for (src = (const struct usb_descriptor_header **)uvc_control_desc;
575 	     *src; ++src) {
576 		control_size += (*src)->bLength;
577 		bytes += (*src)->bLength;
578 		n_desc++;
579 	}
580 
581 	list_for_each_entry(xu, uvc->desc.extension_units, list) {
582 		control_size += xu->desc.bLength;
583 		bytes += xu->desc.bLength;
584 		n_desc++;
585 	}
586 
587 	for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
588 	     *src; ++src) {
589 		streaming_size += (*src)->bLength;
590 		bytes += (*src)->bLength;
591 		n_desc++;
592 	}
593 	for (src = uvc_streaming_std; *src; ++src) {
594 		bytes += (*src)->bLength;
595 		n_desc++;
596 	}
597 
598 	mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
599 	if (mem == NULL)
600 		return NULL;
601 
602 	hdr = mem;
603 	dst = mem;
604 	mem += (n_desc + 1) * sizeof(*src);
605 
606 	/* Copy the descriptors. */
607 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
608 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
609 
610 	uvc_control_header = mem;
611 	UVC_COPY_DESCRIPTORS(mem, dst,
612 		(const struct usb_descriptor_header **)uvc_control_desc);
613 
614 	list_for_each_entry(xu, uvc->desc.extension_units, list)
615 		UVC_COPY_XU_DESCRIPTOR(mem, dst, &xu->desc);
616 
617 	uvc_control_header->wTotalLength = cpu_to_le16(control_size);
618 	uvc_control_header->bInCollection = 1;
619 	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
620 
621 	if (uvc->enable_interrupt_ep) {
622 		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_interrupt_ep);
623 		if (speed == USB_SPEED_SUPER ||
624 		    speed == USB_SPEED_SUPER_PLUS)
625 			UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_interrupt_comp);
626 
627 		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_interrupt_cs_ep);
628 	}
629 
630 	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
631 
632 	uvc_streaming_header = mem;
633 	UVC_COPY_DESCRIPTORS(mem, dst,
634 		(const struct usb_descriptor_header**)uvc_streaming_cls);
635 	uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
636 	uvc_streaming_header->bEndpointAddress = uvc->video.ep->address;
637 
638 	UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
639 
640 	*dst = NULL;
641 	return hdr;
642 }
643 
644 static int
645 uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
646 {
647 	struct usb_composite_dev *cdev = c->cdev;
648 	struct uvc_device *uvc = to_uvc(f);
649 	struct uvcg_extension *xu;
650 	struct usb_string *us;
651 	unsigned int max_packet_mult;
652 	unsigned int max_packet_size;
653 	struct usb_ep *ep;
654 	struct f_uvc_opts *opts;
655 	int ret = -EINVAL;
656 
657 	uvcg_info(f, "%s()\n", __func__);
658 
659 	opts = fi_to_f_uvc_opts(f->fi);
660 	/* Sanity check the streaming endpoint module parameters. */
661 	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
662 	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
663 	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
664 
665 	/* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
666 	if (opts->streaming_maxburst &&
667 	    (opts->streaming_maxpacket % 1024) != 0) {
668 		opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
669 		uvcg_info(f, "overriding streaming_maxpacket to %d\n",
670 			  opts->streaming_maxpacket);
671 	}
672 
673 	/*
674 	 * Fill in the FS/HS/SS Video Streaming specific descriptors from the
675 	 * module parameters.
676 	 *
677 	 * NOTE: We assume that the user knows what they are doing and won't
678 	 * give parameters that their UDC doesn't support.
679 	 */
680 	if (opts->streaming_maxpacket <= 1024) {
681 		max_packet_mult = 1;
682 		max_packet_size = opts->streaming_maxpacket;
683 	} else if (opts->streaming_maxpacket <= 2048) {
684 		max_packet_mult = 2;
685 		max_packet_size = opts->streaming_maxpacket / 2;
686 	} else {
687 		max_packet_mult = 3;
688 		max_packet_size = opts->streaming_maxpacket / 3;
689 	}
690 
691 	uvc_fs_streaming_ep.wMaxPacketSize =
692 		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
693 	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
694 
695 	uvc_hs_streaming_ep.wMaxPacketSize =
696 		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
697 
698 	/* A high-bandwidth endpoint must specify a bInterval value of 1 */
699 	if (max_packet_mult > 1)
700 		uvc_hs_streaming_ep.bInterval = 1;
701 	else
702 		uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
703 
704 	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
705 	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
706 	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
707 	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
708 	uvc_ss_streaming_comp.wBytesPerInterval =
709 		cpu_to_le16(max_packet_size * max_packet_mult *
710 			    (opts->streaming_maxburst + 1));
711 
712 	/* Allocate endpoints. */
713 	if (opts->enable_interrupt_ep) {
714 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_interrupt_ep);
715 		if (!ep) {
716 			uvcg_info(f, "Unable to allocate interrupt EP\n");
717 			goto error;
718 		}
719 		uvc->interrupt_ep = ep;
720 		uvc_control_intf.bNumEndpoints = 1;
721 	}
722 	uvc->enable_interrupt_ep = opts->enable_interrupt_ep;
723 
724 	/*
725 	 * gadget_is_{super|dual}speed() API check UDC controller capitblity. It should pass down
726 	 * highest speed endpoint descriptor to UDC controller. So UDC controller driver can reserve
727 	 * enough resource at check_config(), especially mult and maxburst. So UDC driver (such as
728 	 * cdns3) can know need at least (mult + 1) * (maxburst + 1) * wMaxPacketSize internal
729 	 * memory for this uvc functions. This is the only straightforward method to resolve the UDC
730 	 * resource allocation issue in the current gadget framework.
731 	 */
732 	if (gadget_is_superspeed(c->cdev->gadget))
733 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
734 					  &uvc_ss_streaming_comp);
735 	else if (gadget_is_dualspeed(cdev->gadget))
736 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
737 	else
738 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
739 
740 	if (!ep) {
741 		uvcg_info(f, "Unable to allocate streaming EP\n");
742 		goto error;
743 	}
744 	uvc->video.ep = ep;
745 
746 	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
747 	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
748 	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;
749 
750 	/*
751 	 * XUs can have an arbitrary string descriptor describing them. If they
752 	 * have one pick up the ID.
753 	 */
754 	list_for_each_entry(xu, &opts->extension_units, list)
755 		if (xu->string_descriptor_index)
756 			xu->desc.iExtension = cdev->usb_strings[xu->string_descriptor_index].id;
757 
758 	/*
759 	 * We attach the hard-coded defaults incase the user does not provide
760 	 * any more appropriate strings through configfs.
761 	 */
762 	uvc_en_us_strings[UVC_STRING_CONTROL_IDX].s = opts->function_name;
763 	us = usb_gstrings_attach(cdev, uvc_function_strings,
764 				 ARRAY_SIZE(uvc_en_us_strings));
765 	if (IS_ERR(us)) {
766 		ret = PTR_ERR(us);
767 		goto error;
768 	}
769 
770 	uvc_iad.iFunction = opts->iad_index ? cdev->usb_strings[opts->iad_index].id :
771 			    us[UVC_STRING_CONTROL_IDX].id;
772 	uvc_streaming_intf_alt0.iInterface = opts->vs0_index ?
773 					     cdev->usb_strings[opts->vs0_index].id :
774 					     us[UVC_STRING_STREAMING_IDX].id;
775 	uvc_streaming_intf_alt1.iInterface = opts->vs1_index ?
776 					     cdev->usb_strings[opts->vs1_index].id :
777 					     us[UVC_STRING_STREAMING_IDX].id;
778 
779 	/* Allocate interface IDs. */
780 	if ((ret = usb_interface_id(c, f)) < 0)
781 		goto error;
782 	uvc_iad.bFirstInterface = ret;
783 	uvc_control_intf.bInterfaceNumber = ret;
784 	uvc->control_intf = ret;
785 	opts->control_interface = ret;
786 
787 	if ((ret = usb_interface_id(c, f)) < 0)
788 		goto error;
789 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
790 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
791 	uvc->streaming_intf = ret;
792 	opts->streaming_interface = ret;
793 
794 	/* Copy descriptors */
795 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
796 	if (IS_ERR(f->fs_descriptors)) {
797 		ret = PTR_ERR(f->fs_descriptors);
798 		f->fs_descriptors = NULL;
799 		goto error;
800 	}
801 
802 	f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
803 	if (IS_ERR(f->hs_descriptors)) {
804 		ret = PTR_ERR(f->hs_descriptors);
805 		f->hs_descriptors = NULL;
806 		goto error;
807 	}
808 
809 	f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);
810 	if (IS_ERR(f->ss_descriptors)) {
811 		ret = PTR_ERR(f->ss_descriptors);
812 		f->ss_descriptors = NULL;
813 		goto error;
814 	}
815 
816 	f->ssp_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER_PLUS);
817 	if (IS_ERR(f->ssp_descriptors)) {
818 		ret = PTR_ERR(f->ssp_descriptors);
819 		f->ssp_descriptors = NULL;
820 		goto error;
821 	}
822 
823 	/* Preallocate control endpoint request. */
824 	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
825 	uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
826 	if (uvc->control_req == NULL || uvc->control_buf == NULL) {
827 		ret = -ENOMEM;
828 		goto error;
829 	}
830 
831 	uvc->control_req->buf = uvc->control_buf;
832 	uvc->control_req->complete = uvc_function_ep0_complete;
833 	uvc->control_req->context = uvc;
834 
835 	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
836 		uvcg_err(f, "failed to register V4L2 device\n");
837 		goto error;
838 	}
839 
840 	/* Initialise video. */
841 	ret = uvcg_video_init(&uvc->video, uvc);
842 	if (ret < 0)
843 		goto v4l2_error;
844 
845 	/* Register a V4L2 device. */
846 	ret = uvc_register_video(uvc);
847 	if (ret < 0) {
848 		uvcg_err(f, "failed to register video device\n");
849 		goto v4l2_error;
850 	}
851 
852 	return 0;
853 
854 v4l2_error:
855 	v4l2_device_unregister(&uvc->v4l2_dev);
856 error:
857 	if (uvc->control_req)
858 		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
859 	kfree(uvc->control_buf);
860 
861 	usb_free_all_descriptors(f);
862 	return ret;
863 }
864 
865 /* --------------------------------------------------------------------------
866  * USB gadget function
867  */
868 
869 static void uvc_free_inst(struct usb_function_instance *f)
870 {
871 	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f);
872 
873 	mutex_destroy(&opts->lock);
874 	kfree(opts);
875 }
876 
877 static struct usb_function_instance *uvc_alloc_inst(void)
878 {
879 	struct f_uvc_opts *opts;
880 	struct uvc_camera_terminal_descriptor *cd;
881 	struct uvc_processing_unit_descriptor *pd;
882 	struct uvc_output_terminal_descriptor *od;
883 	struct uvc_descriptor_header **ctl_cls;
884 	int ret;
885 
886 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
887 	if (!opts)
888 		return ERR_PTR(-ENOMEM);
889 	opts->func_inst.free_func_inst = uvc_free_inst;
890 	mutex_init(&opts->lock);
891 
892 	cd = &opts->uvc_camera_terminal;
893 	cd->bLength			= UVC_DT_CAMERA_TERMINAL_SIZE(3);
894 	cd->bDescriptorType		= USB_DT_CS_INTERFACE;
895 	cd->bDescriptorSubType		= UVC_VC_INPUT_TERMINAL;
896 	cd->bTerminalID			= 1;
897 	cd->wTerminalType		= cpu_to_le16(0x0201);
898 	cd->bAssocTerminal		= 0;
899 	cd->iTerminal			= 0;
900 	cd->wObjectiveFocalLengthMin	= cpu_to_le16(0);
901 	cd->wObjectiveFocalLengthMax	= cpu_to_le16(0);
902 	cd->wOcularFocalLength		= cpu_to_le16(0);
903 	cd->bControlSize		= 3;
904 	cd->bmControls[0]		= 2;
905 	cd->bmControls[1]		= 0;
906 	cd->bmControls[2]		= 0;
907 
908 	pd = &opts->uvc_processing;
909 	pd->bLength			= UVC_DT_PROCESSING_UNIT_SIZE(2);
910 	pd->bDescriptorType		= USB_DT_CS_INTERFACE;
911 	pd->bDescriptorSubType		= UVC_VC_PROCESSING_UNIT;
912 	pd->bUnitID			= 2;
913 	pd->bSourceID			= 1;
914 	pd->wMaxMultiplier		= cpu_to_le16(16*1024);
915 	pd->bControlSize		= 2;
916 	pd->bmControls[0]		= 1;
917 	pd->bmControls[1]		= 0;
918 	pd->iProcessing			= 0;
919 	pd->bmVideoStandards		= 0;
920 
921 	od = &opts->uvc_output_terminal;
922 	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;
923 	od->bDescriptorType		= USB_DT_CS_INTERFACE;
924 	od->bDescriptorSubType		= UVC_VC_OUTPUT_TERMINAL;
925 	od->bTerminalID			= 3;
926 	od->wTerminalType		= cpu_to_le16(0x0101);
927 	od->bAssocTerminal		= 0;
928 	od->bSourceID			= 2;
929 	od->iTerminal			= 0;
930 
931 	/*
932 	 * With the ability to add XUs to the UVC function graph, we need to be
933 	 * able to allocate unique unit IDs to them. The IDs are 1-based, with
934 	 * the CT, PU and OT above consuming the first 3.
935 	 */
936 	opts->last_unit_id		= 3;
937 
938 	/* Prepare fs control class descriptors for configfs-based gadgets */
939 	ctl_cls = opts->uvc_fs_control_cls;
940 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
941 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
942 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
943 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
944 	ctl_cls[4] = NULL;	/* NULL-terminate */
945 	opts->fs_control =
946 		(const struct uvc_descriptor_header * const *)ctl_cls;
947 
948 	/* Prepare hs control class descriptors for configfs-based gadgets */
949 	ctl_cls = opts->uvc_ss_control_cls;
950 	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
951 	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
952 	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
953 	ctl_cls[3] = (struct uvc_descriptor_header *)od;
954 	ctl_cls[4] = NULL;	/* NULL-terminate */
955 	opts->ss_control =
956 		(const struct uvc_descriptor_header * const *)ctl_cls;
957 
958 	INIT_LIST_HEAD(&opts->extension_units);
959 
960 	opts->streaming_interval = 1;
961 	opts->streaming_maxpacket = 1024;
962 	snprintf(opts->function_name, sizeof(opts->function_name), "UVC Camera");
963 
964 	ret = uvcg_attach_configfs(opts);
965 	if (ret < 0) {
966 		kfree(opts);
967 		return ERR_PTR(ret);
968 	}
969 
970 	return &opts->func_inst;
971 }
972 
973 static void uvc_free(struct usb_function *f)
974 {
975 	struct uvc_device *uvc = to_uvc(f);
976 	struct f_uvc_opts *opts = container_of(f->fi, struct f_uvc_opts,
977 					       func_inst);
978 	if (!opts->header)
979 		config_item_put(&uvc->header->item);
980 	--opts->refcnt;
981 	kfree(uvc);
982 }
983 
984 static void uvc_function_unbind(struct usb_configuration *c,
985 				struct usb_function *f)
986 {
987 	struct usb_composite_dev *cdev = c->cdev;
988 	struct uvc_device *uvc = to_uvc(f);
989 	struct uvc_video *video = &uvc->video;
990 	long wait_ret = 1;
991 
992 	uvcg_info(f, "%s()\n", __func__);
993 
994 	if (video->async_wq)
995 		destroy_workqueue(video->async_wq);
996 
997 	/*
998 	 * If we know we're connected via v4l2, then there should be a cleanup
999 	 * of the device from userspace either via UVC_EVENT_DISCONNECT or
1000 	 * though the video device removal uevent. Allow some time for the
1001 	 * application to close out before things get deleted.
1002 	 */
1003 	if (uvc->func_connected) {
1004 		uvcg_dbg(f, "waiting for clean disconnect\n");
1005 		wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
1006 				uvc->func_connected == false, msecs_to_jiffies(500));
1007 		uvcg_dbg(f, "done waiting with ret: %ld\n", wait_ret);
1008 	}
1009 
1010 	device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
1011 	video_unregister_device(&uvc->vdev);
1012 	v4l2_device_unregister(&uvc->v4l2_dev);
1013 
1014 	if (uvc->func_connected) {
1015 		/*
1016 		 * Wait for the release to occur to ensure there are no longer any
1017 		 * pending operations that may cause panics when resources are cleaned
1018 		 * up.
1019 		 */
1020 		uvcg_warn(f, "%s no clean disconnect, wait for release\n", __func__);
1021 		wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
1022 				uvc->func_connected == false, msecs_to_jiffies(1000));
1023 		uvcg_dbg(f, "done waiting for release with ret: %ld\n", wait_ret);
1024 	}
1025 
1026 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
1027 	kfree(uvc->control_buf);
1028 
1029 	usb_free_all_descriptors(f);
1030 }
1031 
1032 static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
1033 {
1034 	struct uvc_device *uvc;
1035 	struct f_uvc_opts *opts;
1036 	struct uvc_descriptor_header **strm_cls;
1037 	struct config_item *streaming, *header, *h;
1038 
1039 	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
1040 	if (uvc == NULL)
1041 		return ERR_PTR(-ENOMEM);
1042 
1043 	mutex_init(&uvc->video.mutex);
1044 	uvc->state = UVC_STATE_DISCONNECTED;
1045 	init_waitqueue_head(&uvc->func_connected_queue);
1046 	opts = fi_to_f_uvc_opts(fi);
1047 
1048 	mutex_lock(&opts->lock);
1049 	if (opts->uvc_fs_streaming_cls) {
1050 		strm_cls = opts->uvc_fs_streaming_cls;
1051 		opts->fs_streaming =
1052 			(const struct uvc_descriptor_header * const *)strm_cls;
1053 	}
1054 	if (opts->uvc_hs_streaming_cls) {
1055 		strm_cls = opts->uvc_hs_streaming_cls;
1056 		opts->hs_streaming =
1057 			(const struct uvc_descriptor_header * const *)strm_cls;
1058 	}
1059 	if (opts->uvc_ss_streaming_cls) {
1060 		strm_cls = opts->uvc_ss_streaming_cls;
1061 		opts->ss_streaming =
1062 			(const struct uvc_descriptor_header * const *)strm_cls;
1063 	}
1064 
1065 	uvc->desc.fs_control = opts->fs_control;
1066 	uvc->desc.ss_control = opts->ss_control;
1067 	uvc->desc.fs_streaming = opts->fs_streaming;
1068 	uvc->desc.hs_streaming = opts->hs_streaming;
1069 	uvc->desc.ss_streaming = opts->ss_streaming;
1070 
1071 	if (opts->header) {
1072 		uvc->header = opts->header;
1073 	} else {
1074 		streaming = config_group_find_item(&opts->func_inst.group, "streaming");
1075 		if (!streaming)
1076 			goto err_config;
1077 
1078 		header = config_group_find_item(to_config_group(streaming), "header");
1079 		config_item_put(streaming);
1080 		if (!header)
1081 			goto err_config;
1082 
1083 		h = config_group_find_item(to_config_group(header), "h");
1084 		config_item_put(header);
1085 		if (!h)
1086 			goto err_config;
1087 
1088 		uvc->header = to_uvcg_streaming_header(h);
1089 		if (!uvc->header->linked) {
1090 			mutex_unlock(&opts->lock);
1091 			kfree(uvc);
1092 			return ERR_PTR(-EBUSY);
1093 		}
1094 	}
1095 
1096 	uvc->desc.extension_units = &opts->extension_units;
1097 
1098 	++opts->refcnt;
1099 	mutex_unlock(&opts->lock);
1100 
1101 	/* Register the function. */
1102 	uvc->func.name = "uvc";
1103 	uvc->func.bind = uvc_function_bind;
1104 	uvc->func.unbind = uvc_function_unbind;
1105 	uvc->func.get_alt = uvc_function_get_alt;
1106 	uvc->func.set_alt = uvc_function_set_alt;
1107 	uvc->func.disable = uvc_function_disable;
1108 	uvc->func.setup = uvc_function_setup;
1109 	uvc->func.free_func = uvc_free;
1110 	uvc->func.bind_deactivated = true;
1111 
1112 	return &uvc->func;
1113 
1114 err_config:
1115 	mutex_unlock(&opts->lock);
1116 	kfree(uvc);
1117 	return ERR_PTR(-ENOENT);
1118 }
1119 
1120 DECLARE_USB_FUNCTION_INIT(uvc, uvc_alloc_inst, uvc_alloc);
1121 MODULE_LICENSE("GPL");
1122 MODULE_AUTHOR("Laurent Pinchart");
1123