xref: /linux/drivers/usb/gadget/function/uvc_configfs.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * uvc_configfs.c
4  *
5  * Configfs support for the uvc function.
6  *
7  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
8  *		http://www.samsung.com
9  *
10  * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
11  */
12 
13 #include <linux/sort.h>
14 
15 #include "u_uvc.h"
16 #include "uvc_configfs.h"
17 
18 /* -----------------------------------------------------------------------------
19  * Global Utility Structures and Macros
20  */
21 
22 #define UVCG_STREAMING_CONTROL_SIZE	1
23 
24 #define UVC_ATTR(prefix, cname, aname) \
25 static struct configfs_attribute prefix##attr_##cname = { \
26 	.ca_name	= __stringify(aname),				\
27 	.ca_mode	= S_IRUGO | S_IWUGO,				\
28 	.ca_owner	= THIS_MODULE,					\
29 	.show		= prefix##cname##_show,				\
30 	.store		= prefix##cname##_store,			\
31 }
32 
33 #define UVC_ATTR_RO(prefix, cname, aname) \
34 static struct configfs_attribute prefix##attr_##cname = { \
35 	.ca_name	= __stringify(aname),				\
36 	.ca_mode	= S_IRUGO,					\
37 	.ca_owner	= THIS_MODULE,					\
38 	.show		= prefix##cname##_show,				\
39 }
40 
41 #define le8_to_cpu(x)	(x)
42 #define cpu_to_le8(x)	(x)
43 
44 static int uvcg_config_compare_u32(const void *l, const void *r)
45 {
46 	u32 li = *(const u32 *)l;
47 	u32 ri = *(const u32 *)r;
48 
49 	return li < ri ? -1 : li == ri ? 0 : 1;
50 }
51 
52 static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
53 {
54 	return container_of(to_config_group(item), struct f_uvc_opts,
55 			    func_inst.group);
56 }
57 
58 struct uvcg_config_group_type {
59 	struct config_item_type type;
60 	const char *name;
61 	const struct uvcg_config_group_type **children;
62 	int (*create_children)(struct config_group *group);
63 };
64 
65 static void uvcg_config_item_release(struct config_item *item)
66 {
67 	struct config_group *group = to_config_group(item);
68 
69 	kfree(group);
70 }
71 
72 static struct configfs_item_operations uvcg_config_item_ops = {
73 	.release	= uvcg_config_item_release,
74 };
75 
76 static int uvcg_config_create_group(struct config_group *parent,
77 				    const struct uvcg_config_group_type *type);
78 
79 static int uvcg_config_create_children(struct config_group *group,
80 				const struct uvcg_config_group_type *type)
81 {
82 	const struct uvcg_config_group_type **child;
83 	int ret;
84 
85 	if (type->create_children)
86 		return type->create_children(group);
87 
88 	for (child = type->children; child && *child; ++child) {
89 		ret = uvcg_config_create_group(group, *child);
90 		if (ret < 0)
91 			return ret;
92 	}
93 
94 	return 0;
95 }
96 
97 static int uvcg_config_create_group(struct config_group *parent,
98 				    const struct uvcg_config_group_type *type)
99 {
100 	struct config_group *group;
101 
102 	group = kzalloc(sizeof(*group), GFP_KERNEL);
103 	if (!group)
104 		return -ENOMEM;
105 
106 	config_group_init_type_name(group, type->name, &type->type);
107 	configfs_add_default_group(group, parent);
108 
109 	return uvcg_config_create_children(group, type);
110 }
111 
112 static void uvcg_config_remove_children(struct config_group *group)
113 {
114 	struct config_group *child, *n;
115 
116 	list_for_each_entry_safe(child, n, &group->default_groups, group_entry) {
117 		list_del(&child->group_entry);
118 		uvcg_config_remove_children(child);
119 		config_item_put(&child->cg_item);
120 	}
121 }
122 
123 /* -----------------------------------------------------------------------------
124  * control/header/<NAME>
125  * control/header
126  */
127 
128 DECLARE_UVC_HEADER_DESCRIPTOR(1);
129 
130 struct uvcg_control_header {
131 	struct config_item		item;
132 	struct UVC_HEADER_DESCRIPTOR(1)	desc;
133 	unsigned			linked;
134 };
135 
136 static struct uvcg_control_header *to_uvcg_control_header(struct config_item *item)
137 {
138 	return container_of(item, struct uvcg_control_header, item);
139 }
140 
141 #define UVCG_CTRL_HDR_ATTR(cname, aname, bits, limit)			\
142 static ssize_t uvcg_control_header_##cname##_show(			\
143 	struct config_item *item, char *page)				\
144 {									\
145 	struct uvcg_control_header *ch = to_uvcg_control_header(item);	\
146 	struct f_uvc_opts *opts;					\
147 	struct config_item *opts_item;					\
148 	struct mutex *su_mutex = &ch->item.ci_group->cg_subsys->su_mutex;\
149 	int result;							\
150 									\
151 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
152 									\
153 	opts_item = ch->item.ci_parent->ci_parent->ci_parent;		\
154 	opts = to_f_uvc_opts(opts_item);				\
155 									\
156 	mutex_lock(&opts->lock);					\
157 	result = sprintf(page, "%u\n", le##bits##_to_cpu(ch->desc.aname));\
158 	mutex_unlock(&opts->lock);					\
159 									\
160 	mutex_unlock(su_mutex);						\
161 	return result;							\
162 }									\
163 									\
164 static ssize_t								\
165 uvcg_control_header_##cname##_store(struct config_item *item,		\
166 			   const char *page, size_t len)		\
167 {									\
168 	struct uvcg_control_header *ch = to_uvcg_control_header(item);	\
169 	struct f_uvc_opts *opts;					\
170 	struct config_item *opts_item;					\
171 	struct mutex *su_mutex = &ch->item.ci_group->cg_subsys->su_mutex;\
172 	int ret;							\
173 	u##bits num;							\
174 									\
175 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
176 									\
177 	opts_item = ch->item.ci_parent->ci_parent->ci_parent;		\
178 	opts = to_f_uvc_opts(opts_item);				\
179 									\
180 	mutex_lock(&opts->lock);					\
181 	if (ch->linked || opts->refcnt) {				\
182 		ret = -EBUSY;						\
183 		goto end;						\
184 	}								\
185 									\
186 	ret = kstrtou##bits(page, 0, &num);				\
187 	if (ret)							\
188 		goto end;						\
189 									\
190 	if (num > limit) {						\
191 		ret = -EINVAL;						\
192 		goto end;						\
193 	}								\
194 	ch->desc.aname = cpu_to_le##bits(num);				\
195 	ret = len;							\
196 end:									\
197 	mutex_unlock(&opts->lock);					\
198 	mutex_unlock(su_mutex);						\
199 	return ret;							\
200 }									\
201 									\
202 UVC_ATTR(uvcg_control_header_, cname, aname)
203 
204 UVCG_CTRL_HDR_ATTR(bcd_uvc, bcdUVC, 16, 0xffff);
205 
206 UVCG_CTRL_HDR_ATTR(dw_clock_frequency, dwClockFrequency, 32, 0x7fffffff);
207 
208 #undef UVCG_CTRL_HDR_ATTR
209 
210 static struct configfs_attribute *uvcg_control_header_attrs[] = {
211 	&uvcg_control_header_attr_bcd_uvc,
212 	&uvcg_control_header_attr_dw_clock_frequency,
213 	NULL,
214 };
215 
216 static const struct config_item_type uvcg_control_header_type = {
217 	.ct_item_ops	= &uvcg_config_item_ops,
218 	.ct_attrs	= uvcg_control_header_attrs,
219 	.ct_owner	= THIS_MODULE,
220 };
221 
222 static struct config_item *uvcg_control_header_make(struct config_group *group,
223 						    const char *name)
224 {
225 	struct uvcg_control_header *h;
226 
227 	h = kzalloc(sizeof(*h), GFP_KERNEL);
228 	if (!h)
229 		return ERR_PTR(-ENOMEM);
230 
231 	h->desc.bLength			= UVC_DT_HEADER_SIZE(1);
232 	h->desc.bDescriptorType		= USB_DT_CS_INTERFACE;
233 	h->desc.bDescriptorSubType	= UVC_VC_HEADER;
234 	h->desc.bcdUVC			= cpu_to_le16(0x0100);
235 	h->desc.dwClockFrequency	= cpu_to_le32(48000000);
236 
237 	config_item_init_type_name(&h->item, name, &uvcg_control_header_type);
238 
239 	return &h->item;
240 }
241 
242 static struct configfs_group_operations uvcg_control_header_grp_ops = {
243 	.make_item		= uvcg_control_header_make,
244 };
245 
246 static const struct uvcg_config_group_type uvcg_control_header_grp_type = {
247 	.type = {
248 		.ct_item_ops	= &uvcg_config_item_ops,
249 		.ct_group_ops	= &uvcg_control_header_grp_ops,
250 		.ct_owner	= THIS_MODULE,
251 	},
252 	.name = "header",
253 };
254 
255 /* -----------------------------------------------------------------------------
256  * control/processing/default
257  */
258 
259 #define UVCG_DEFAULT_PROCESSING_ATTR(cname, aname, bits)		\
260 static ssize_t uvcg_default_processing_##cname##_show(			\
261 	struct config_item *item, char *page)				\
262 {									\
263 	struct config_group *group = to_config_group(item);		\
264 	struct f_uvc_opts *opts;					\
265 	struct config_item *opts_item;					\
266 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
267 	struct uvc_processing_unit_descriptor *pd;			\
268 	int result;							\
269 									\
270 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
271 									\
272 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;	\
273 	opts = to_f_uvc_opts(opts_item);				\
274 	pd = &opts->uvc_processing;					\
275 									\
276 	mutex_lock(&opts->lock);					\
277 	result = sprintf(page, "%u\n", le##bits##_to_cpu(pd->aname));	\
278 	mutex_unlock(&opts->lock);					\
279 									\
280 	mutex_unlock(su_mutex);						\
281 	return result;							\
282 }									\
283 									\
284 UVC_ATTR_RO(uvcg_default_processing_, cname, aname)
285 
286 UVCG_DEFAULT_PROCESSING_ATTR(b_unit_id, bUnitID, 8);
287 UVCG_DEFAULT_PROCESSING_ATTR(b_source_id, bSourceID, 8);
288 UVCG_DEFAULT_PROCESSING_ATTR(w_max_multiplier, wMaxMultiplier, 16);
289 UVCG_DEFAULT_PROCESSING_ATTR(i_processing, iProcessing, 8);
290 
291 #undef UVCG_DEFAULT_PROCESSING_ATTR
292 
293 static ssize_t uvcg_default_processing_bm_controls_show(
294 	struct config_item *item, char *page)
295 {
296 	struct config_group *group = to_config_group(item);
297 	struct f_uvc_opts *opts;
298 	struct config_item *opts_item;
299 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
300 	struct uvc_processing_unit_descriptor *pd;
301 	int result, i;
302 	char *pg = page;
303 
304 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
305 
306 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;
307 	opts = to_f_uvc_opts(opts_item);
308 	pd = &opts->uvc_processing;
309 
310 	mutex_lock(&opts->lock);
311 	for (result = 0, i = 0; i < pd->bControlSize; ++i) {
312 		result += sprintf(pg, "%u\n", pd->bmControls[i]);
313 		pg = page + result;
314 	}
315 	mutex_unlock(&opts->lock);
316 
317 	mutex_unlock(su_mutex);
318 
319 	return result;
320 }
321 
322 UVC_ATTR_RO(uvcg_default_processing_, bm_controls, bmControls);
323 
324 static struct configfs_attribute *uvcg_default_processing_attrs[] = {
325 	&uvcg_default_processing_attr_b_unit_id,
326 	&uvcg_default_processing_attr_b_source_id,
327 	&uvcg_default_processing_attr_w_max_multiplier,
328 	&uvcg_default_processing_attr_bm_controls,
329 	&uvcg_default_processing_attr_i_processing,
330 	NULL,
331 };
332 
333 static const struct uvcg_config_group_type uvcg_default_processing_type = {
334 	.type = {
335 		.ct_item_ops	= &uvcg_config_item_ops,
336 		.ct_attrs	= uvcg_default_processing_attrs,
337 		.ct_owner	= THIS_MODULE,
338 	},
339 	.name = "default",
340 };
341 
342 /* -----------------------------------------------------------------------------
343  * control/processing
344  */
345 
346 static const struct uvcg_config_group_type uvcg_processing_grp_type = {
347 	.type = {
348 		.ct_item_ops	= &uvcg_config_item_ops,
349 		.ct_owner	= THIS_MODULE,
350 	},
351 	.name = "processing",
352 	.children = (const struct uvcg_config_group_type*[]) {
353 		&uvcg_default_processing_type,
354 		NULL,
355 	},
356 };
357 
358 /* -----------------------------------------------------------------------------
359  * control/terminal/camera/default
360  */
361 
362 #define UVCG_DEFAULT_CAMERA_ATTR(cname, aname, bits)			\
363 static ssize_t uvcg_default_camera_##cname##_show(			\
364 	struct config_item *item, char *page)				\
365 {									\
366 	struct config_group *group = to_config_group(item);		\
367 	struct f_uvc_opts *opts;					\
368 	struct config_item *opts_item;					\
369 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
370 	struct uvc_camera_terminal_descriptor *cd;			\
371 	int result;							\
372 									\
373 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
374 									\
375 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent->	\
376 			ci_parent;					\
377 	opts = to_f_uvc_opts(opts_item);				\
378 	cd = &opts->uvc_camera_terminal;				\
379 									\
380 	mutex_lock(&opts->lock);					\
381 	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
382 	mutex_unlock(&opts->lock);					\
383 									\
384 	mutex_unlock(su_mutex);						\
385 									\
386 	return result;							\
387 }									\
388 									\
389 UVC_ATTR_RO(uvcg_default_camera_, cname, aname)
390 
391 UVCG_DEFAULT_CAMERA_ATTR(b_terminal_id, bTerminalID, 8);
392 UVCG_DEFAULT_CAMERA_ATTR(w_terminal_type, wTerminalType, 16);
393 UVCG_DEFAULT_CAMERA_ATTR(b_assoc_terminal, bAssocTerminal, 8);
394 UVCG_DEFAULT_CAMERA_ATTR(i_terminal, iTerminal, 8);
395 UVCG_DEFAULT_CAMERA_ATTR(w_objective_focal_length_min, wObjectiveFocalLengthMin,
396 			 16);
397 UVCG_DEFAULT_CAMERA_ATTR(w_objective_focal_length_max, wObjectiveFocalLengthMax,
398 			 16);
399 UVCG_DEFAULT_CAMERA_ATTR(w_ocular_focal_length, wOcularFocalLength,
400 			 16);
401 
402 #undef UVCG_DEFAULT_CAMERA_ATTR
403 
404 static ssize_t uvcg_default_camera_bm_controls_show(
405 	struct config_item *item, char *page)
406 {
407 	struct config_group *group = to_config_group(item);
408 	struct f_uvc_opts *opts;
409 	struct config_item *opts_item;
410 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
411 	struct uvc_camera_terminal_descriptor *cd;
412 	int result, i;
413 	char *pg = page;
414 
415 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
416 
417 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent->
418 			ci_parent;
419 	opts = to_f_uvc_opts(opts_item);
420 	cd = &opts->uvc_camera_terminal;
421 
422 	mutex_lock(&opts->lock);
423 	for (result = 0, i = 0; i < cd->bControlSize; ++i) {
424 		result += sprintf(pg, "%u\n", cd->bmControls[i]);
425 		pg = page + result;
426 	}
427 	mutex_unlock(&opts->lock);
428 
429 	mutex_unlock(su_mutex);
430 	return result;
431 }
432 
433 UVC_ATTR_RO(uvcg_default_camera_, bm_controls, bmControls);
434 
435 static struct configfs_attribute *uvcg_default_camera_attrs[] = {
436 	&uvcg_default_camera_attr_b_terminal_id,
437 	&uvcg_default_camera_attr_w_terminal_type,
438 	&uvcg_default_camera_attr_b_assoc_terminal,
439 	&uvcg_default_camera_attr_i_terminal,
440 	&uvcg_default_camera_attr_w_objective_focal_length_min,
441 	&uvcg_default_camera_attr_w_objective_focal_length_max,
442 	&uvcg_default_camera_attr_w_ocular_focal_length,
443 	&uvcg_default_camera_attr_bm_controls,
444 	NULL,
445 };
446 
447 static const struct uvcg_config_group_type uvcg_default_camera_type = {
448 	.type = {
449 		.ct_item_ops	= &uvcg_config_item_ops,
450 		.ct_attrs	= uvcg_default_camera_attrs,
451 		.ct_owner	= THIS_MODULE,
452 	},
453 	.name = "default",
454 };
455 
456 /* -----------------------------------------------------------------------------
457  * control/terminal/camera
458  */
459 
460 static const struct uvcg_config_group_type uvcg_camera_grp_type = {
461 	.type = {
462 		.ct_item_ops	= &uvcg_config_item_ops,
463 		.ct_owner	= THIS_MODULE,
464 	},
465 	.name = "camera",
466 	.children = (const struct uvcg_config_group_type*[]) {
467 		&uvcg_default_camera_type,
468 		NULL,
469 	},
470 };
471 
472 /* -----------------------------------------------------------------------------
473  * control/terminal/output/default
474  */
475 
476 #define UVCG_DEFAULT_OUTPUT_ATTR(cname, aname, bits)			\
477 static ssize_t uvcg_default_output_##cname##_show(			\
478 	struct config_item *item, char *page)				\
479 {									\
480 	struct config_group *group = to_config_group(item);		\
481 	struct f_uvc_opts *opts;					\
482 	struct config_item *opts_item;					\
483 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
484 	struct uvc_output_terminal_descriptor *cd;			\
485 	int result;							\
486 									\
487 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
488 									\
489 	opts_item = group->cg_item.ci_parent->ci_parent->		\
490 			ci_parent->ci_parent;				\
491 	opts = to_f_uvc_opts(opts_item);				\
492 	cd = &opts->uvc_output_terminal;				\
493 									\
494 	mutex_lock(&opts->lock);					\
495 	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
496 	mutex_unlock(&opts->lock);					\
497 									\
498 	mutex_unlock(su_mutex);						\
499 									\
500 	return result;							\
501 }									\
502 									\
503 UVC_ATTR_RO(uvcg_default_output_, cname, aname)
504 
505 UVCG_DEFAULT_OUTPUT_ATTR(b_terminal_id, bTerminalID, 8);
506 UVCG_DEFAULT_OUTPUT_ATTR(w_terminal_type, wTerminalType, 16);
507 UVCG_DEFAULT_OUTPUT_ATTR(b_assoc_terminal, bAssocTerminal, 8);
508 UVCG_DEFAULT_OUTPUT_ATTR(b_source_id, bSourceID, 8);
509 UVCG_DEFAULT_OUTPUT_ATTR(i_terminal, iTerminal, 8);
510 
511 #undef UVCG_DEFAULT_OUTPUT_ATTR
512 
513 static struct configfs_attribute *uvcg_default_output_attrs[] = {
514 	&uvcg_default_output_attr_b_terminal_id,
515 	&uvcg_default_output_attr_w_terminal_type,
516 	&uvcg_default_output_attr_b_assoc_terminal,
517 	&uvcg_default_output_attr_b_source_id,
518 	&uvcg_default_output_attr_i_terminal,
519 	NULL,
520 };
521 
522 static const struct uvcg_config_group_type uvcg_default_output_type = {
523 	.type = {
524 		.ct_item_ops	= &uvcg_config_item_ops,
525 		.ct_attrs	= uvcg_default_output_attrs,
526 		.ct_owner	= THIS_MODULE,
527 	},
528 	.name = "default",
529 };
530 
531 /* -----------------------------------------------------------------------------
532  * control/terminal/output
533  */
534 
535 static const struct uvcg_config_group_type uvcg_output_grp_type = {
536 	.type = {
537 		.ct_item_ops	= &uvcg_config_item_ops,
538 		.ct_owner	= THIS_MODULE,
539 	},
540 	.name = "output",
541 	.children = (const struct uvcg_config_group_type*[]) {
542 		&uvcg_default_output_type,
543 		NULL,
544 	},
545 };
546 
547 /* -----------------------------------------------------------------------------
548  * control/terminal
549  */
550 
551 static const struct uvcg_config_group_type uvcg_terminal_grp_type = {
552 	.type = {
553 		.ct_item_ops	= &uvcg_config_item_ops,
554 		.ct_owner	= THIS_MODULE,
555 	},
556 	.name = "terminal",
557 	.children = (const struct uvcg_config_group_type*[]) {
558 		&uvcg_camera_grp_type,
559 		&uvcg_output_grp_type,
560 		NULL,
561 	},
562 };
563 
564 /* -----------------------------------------------------------------------------
565  * control/class/{fs|ss}
566  */
567 
568 struct uvcg_control_class_group {
569 	struct config_group group;
570 	const char *name;
571 };
572 
573 static inline struct uvc_descriptor_header
574 **uvcg_get_ctl_class_arr(struct config_item *i, struct f_uvc_opts *o)
575 {
576 	struct uvcg_control_class_group *group =
577 		container_of(i, struct uvcg_control_class_group,
578 			     group.cg_item);
579 
580 	if (!strcmp(group->name, "fs"))
581 		return o->uvc_fs_control_cls;
582 
583 	if (!strcmp(group->name, "ss"))
584 		return o->uvc_ss_control_cls;
585 
586 	return NULL;
587 }
588 
589 static int uvcg_control_class_allow_link(struct config_item *src,
590 					 struct config_item *target)
591 {
592 	struct config_item *control, *header;
593 	struct f_uvc_opts *opts;
594 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
595 	struct uvc_descriptor_header **class_array;
596 	struct uvcg_control_header *target_hdr;
597 	int ret = -EINVAL;
598 
599 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
600 
601 	control = src->ci_parent->ci_parent;
602 	header = config_group_find_item(to_config_group(control), "header");
603 	if (!header || target->ci_parent != header)
604 		goto out;
605 
606 	opts = to_f_uvc_opts(control->ci_parent);
607 
608 	mutex_lock(&opts->lock);
609 
610 	class_array = uvcg_get_ctl_class_arr(src, opts);
611 	if (!class_array)
612 		goto unlock;
613 	if (opts->refcnt || class_array[0]) {
614 		ret = -EBUSY;
615 		goto unlock;
616 	}
617 
618 	target_hdr = to_uvcg_control_header(target);
619 	++target_hdr->linked;
620 	class_array[0] = (struct uvc_descriptor_header *)&target_hdr->desc;
621 	ret = 0;
622 
623 unlock:
624 	mutex_unlock(&opts->lock);
625 out:
626 	config_item_put(header);
627 	mutex_unlock(su_mutex);
628 	return ret;
629 }
630 
631 static void uvcg_control_class_drop_link(struct config_item *src,
632 					struct config_item *target)
633 {
634 	struct config_item *control, *header;
635 	struct f_uvc_opts *opts;
636 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
637 	struct uvc_descriptor_header **class_array;
638 	struct uvcg_control_header *target_hdr;
639 
640 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
641 
642 	control = src->ci_parent->ci_parent;
643 	header = config_group_find_item(to_config_group(control), "header");
644 	if (!header || target->ci_parent != header)
645 		goto out;
646 
647 	opts = to_f_uvc_opts(control->ci_parent);
648 
649 	mutex_lock(&opts->lock);
650 
651 	class_array = uvcg_get_ctl_class_arr(src, opts);
652 	if (!class_array || opts->refcnt)
653 		goto unlock;
654 
655 	target_hdr = to_uvcg_control_header(target);
656 	--target_hdr->linked;
657 	class_array[0] = NULL;
658 
659 unlock:
660 	mutex_unlock(&opts->lock);
661 out:
662 	config_item_put(header);
663 	mutex_unlock(su_mutex);
664 }
665 
666 static struct configfs_item_operations uvcg_control_class_item_ops = {
667 	.release	= uvcg_config_item_release,
668 	.allow_link	= uvcg_control_class_allow_link,
669 	.drop_link	= uvcg_control_class_drop_link,
670 };
671 
672 static const struct config_item_type uvcg_control_class_type = {
673 	.ct_item_ops	= &uvcg_control_class_item_ops,
674 	.ct_owner	= THIS_MODULE,
675 };
676 
677 /* -----------------------------------------------------------------------------
678  * control/class
679  */
680 
681 static int uvcg_control_class_create_children(struct config_group *parent)
682 {
683 	static const char * const names[] = { "fs", "ss" };
684 	unsigned int i;
685 
686 	for (i = 0; i < ARRAY_SIZE(names); ++i) {
687 		struct uvcg_control_class_group *group;
688 
689 		group = kzalloc(sizeof(*group), GFP_KERNEL);
690 		if (!group)
691 			return -ENOMEM;
692 
693 		group->name = names[i];
694 
695 		config_group_init_type_name(&group->group, group->name,
696 					    &uvcg_control_class_type);
697 		configfs_add_default_group(&group->group, parent);
698 	}
699 
700 	return 0;
701 }
702 
703 static const struct uvcg_config_group_type uvcg_control_class_grp_type = {
704 	.type = {
705 		.ct_item_ops	= &uvcg_config_item_ops,
706 		.ct_owner	= THIS_MODULE,
707 	},
708 	.name = "class",
709 	.create_children = uvcg_control_class_create_children,
710 };
711 
712 /* -----------------------------------------------------------------------------
713  * control
714  */
715 
716 static ssize_t uvcg_default_control_b_interface_number_show(
717 	struct config_item *item, char *page)
718 {
719 	struct config_group *group = to_config_group(item);
720 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
721 	struct config_item *opts_item;
722 	struct f_uvc_opts *opts;
723 	int result = 0;
724 
725 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
726 
727 	opts_item = item->ci_parent;
728 	opts = to_f_uvc_opts(opts_item);
729 
730 	mutex_lock(&opts->lock);
731 	result += sprintf(page, "%u\n", opts->control_interface);
732 	mutex_unlock(&opts->lock);
733 
734 	mutex_unlock(su_mutex);
735 
736 	return result;
737 }
738 
739 UVC_ATTR_RO(uvcg_default_control_, b_interface_number, bInterfaceNumber);
740 
741 static struct configfs_attribute *uvcg_default_control_attrs[] = {
742 	&uvcg_default_control_attr_b_interface_number,
743 	NULL,
744 };
745 
746 static const struct uvcg_config_group_type uvcg_control_grp_type = {
747 	.type = {
748 		.ct_item_ops	= &uvcg_config_item_ops,
749 		.ct_attrs	= uvcg_default_control_attrs,
750 		.ct_owner	= THIS_MODULE,
751 	},
752 	.name = "control",
753 	.children = (const struct uvcg_config_group_type*[]) {
754 		&uvcg_control_header_grp_type,
755 		&uvcg_processing_grp_type,
756 		&uvcg_terminal_grp_type,
757 		&uvcg_control_class_grp_type,
758 		NULL,
759 	},
760 };
761 
762 /* -----------------------------------------------------------------------------
763  * streaming/uncompressed
764  * streaming/mjpeg
765  */
766 
767 static const char * const uvcg_format_names[] = {
768 	"uncompressed",
769 	"mjpeg",
770 };
771 
772 enum uvcg_format_type {
773 	UVCG_UNCOMPRESSED = 0,
774 	UVCG_MJPEG,
775 };
776 
777 struct uvcg_format {
778 	struct config_group	group;
779 	enum uvcg_format_type	type;
780 	unsigned		linked;
781 	unsigned		num_frames;
782 	__u8			bmaControls[UVCG_STREAMING_CONTROL_SIZE];
783 };
784 
785 static struct uvcg_format *to_uvcg_format(struct config_item *item)
786 {
787 	return container_of(to_config_group(item), struct uvcg_format, group);
788 }
789 
790 static ssize_t uvcg_format_bma_controls_show(struct uvcg_format *f, char *page)
791 {
792 	struct f_uvc_opts *opts;
793 	struct config_item *opts_item;
794 	struct mutex *su_mutex = &f->group.cg_subsys->su_mutex;
795 	int result, i;
796 	char *pg = page;
797 
798 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
799 
800 	opts_item = f->group.cg_item.ci_parent->ci_parent->ci_parent;
801 	opts = to_f_uvc_opts(opts_item);
802 
803 	mutex_lock(&opts->lock);
804 	result = sprintf(pg, "0x");
805 	pg += result;
806 	for (i = 0; i < UVCG_STREAMING_CONTROL_SIZE; ++i) {
807 		result += sprintf(pg, "%x\n", f->bmaControls[i]);
808 		pg = page + result;
809 	}
810 	mutex_unlock(&opts->lock);
811 
812 	mutex_unlock(su_mutex);
813 	return result;
814 }
815 
816 static ssize_t uvcg_format_bma_controls_store(struct uvcg_format *ch,
817 					      const char *page, size_t len)
818 {
819 	struct f_uvc_opts *opts;
820 	struct config_item *opts_item;
821 	struct mutex *su_mutex = &ch->group.cg_subsys->su_mutex;
822 	int ret = -EINVAL;
823 
824 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
825 
826 	opts_item = ch->group.cg_item.ci_parent->ci_parent->ci_parent;
827 	opts = to_f_uvc_opts(opts_item);
828 
829 	mutex_lock(&opts->lock);
830 	if (ch->linked || opts->refcnt) {
831 		ret = -EBUSY;
832 		goto end;
833 	}
834 
835 	if (len < 4 || *page != '0' ||
836 	    (*(page + 1) != 'x' && *(page + 1) != 'X'))
837 		goto end;
838 	ret = hex2bin(ch->bmaControls, page + 2, 1);
839 	if (ret < 0)
840 		goto end;
841 	ret = len;
842 end:
843 	mutex_unlock(&opts->lock);
844 	mutex_unlock(su_mutex);
845 	return ret;
846 }
847 
848 struct uvcg_format_ptr {
849 	struct uvcg_format	*fmt;
850 	struct list_head	entry;
851 };
852 
853 /* -----------------------------------------------------------------------------
854  * streaming/header/<NAME>
855  * streaming/header
856  */
857 
858 struct uvcg_streaming_header {
859 	struct config_item				item;
860 	struct uvc_input_header_descriptor		desc;
861 	unsigned					linked;
862 	struct list_head				formats;
863 	unsigned					num_fmt;
864 };
865 
866 static struct uvcg_streaming_header *to_uvcg_streaming_header(struct config_item *item)
867 {
868 	return container_of(item, struct uvcg_streaming_header, item);
869 }
870 
871 static void uvcg_format_set_indices(struct config_group *fmt);
872 
873 static int uvcg_streaming_header_allow_link(struct config_item *src,
874 					    struct config_item *target)
875 {
876 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
877 	struct config_item *opts_item;
878 	struct f_uvc_opts *opts;
879 	struct uvcg_streaming_header *src_hdr;
880 	struct uvcg_format *target_fmt = NULL;
881 	struct uvcg_format_ptr *format_ptr;
882 	int i, ret = -EINVAL;
883 
884 	src_hdr = to_uvcg_streaming_header(src);
885 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
886 
887 	opts_item = src->ci_parent->ci_parent->ci_parent;
888 	opts = to_f_uvc_opts(opts_item);
889 
890 	mutex_lock(&opts->lock);
891 
892 	if (src_hdr->linked) {
893 		ret = -EBUSY;
894 		goto out;
895 	}
896 
897 	/*
898 	 * Linking is only allowed to direct children of the format nodes
899 	 * (streaming/uncompressed or streaming/mjpeg nodes). First check that
900 	 * the grand-parent of the target matches the grand-parent of the source
901 	 * (the streaming node), and then verify that the target parent is a
902 	 * format node.
903 	 */
904 	if (src->ci_parent->ci_parent != target->ci_parent->ci_parent)
905 		goto out;
906 
907 	for (i = 0; i < ARRAY_SIZE(uvcg_format_names); ++i) {
908 		if (!strcmp(target->ci_parent->ci_name, uvcg_format_names[i]))
909 			break;
910 	}
911 
912 	if (i == ARRAY_SIZE(uvcg_format_names))
913 		goto out;
914 
915 	target_fmt = container_of(to_config_group(target), struct uvcg_format,
916 				  group);
917 	if (!target_fmt)
918 		goto out;
919 
920 	uvcg_format_set_indices(to_config_group(target));
921 
922 	format_ptr = kzalloc(sizeof(*format_ptr), GFP_KERNEL);
923 	if (!format_ptr) {
924 		ret = -ENOMEM;
925 		goto out;
926 	}
927 	ret = 0;
928 	format_ptr->fmt = target_fmt;
929 	list_add_tail(&format_ptr->entry, &src_hdr->formats);
930 	++src_hdr->num_fmt;
931 	++target_fmt->linked;
932 
933 out:
934 	mutex_unlock(&opts->lock);
935 	mutex_unlock(su_mutex);
936 	return ret;
937 }
938 
939 static void uvcg_streaming_header_drop_link(struct config_item *src,
940 					   struct config_item *target)
941 {
942 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
943 	struct config_item *opts_item;
944 	struct f_uvc_opts *opts;
945 	struct uvcg_streaming_header *src_hdr;
946 	struct uvcg_format *target_fmt = NULL;
947 	struct uvcg_format_ptr *format_ptr, *tmp;
948 
949 	src_hdr = to_uvcg_streaming_header(src);
950 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
951 
952 	opts_item = src->ci_parent->ci_parent->ci_parent;
953 	opts = to_f_uvc_opts(opts_item);
954 
955 	mutex_lock(&opts->lock);
956 	target_fmt = container_of(to_config_group(target), struct uvcg_format,
957 				  group);
958 	if (!target_fmt)
959 		goto out;
960 
961 	list_for_each_entry_safe(format_ptr, tmp, &src_hdr->formats, entry)
962 		if (format_ptr->fmt == target_fmt) {
963 			list_del(&format_ptr->entry);
964 			kfree(format_ptr);
965 			--src_hdr->num_fmt;
966 			break;
967 		}
968 
969 	--target_fmt->linked;
970 
971 out:
972 	mutex_unlock(&opts->lock);
973 	mutex_unlock(su_mutex);
974 }
975 
976 static struct configfs_item_operations uvcg_streaming_header_item_ops = {
977 	.release	= uvcg_config_item_release,
978 	.allow_link	= uvcg_streaming_header_allow_link,
979 	.drop_link	= uvcg_streaming_header_drop_link,
980 };
981 
982 #define UVCG_STREAMING_HEADER_ATTR(cname, aname, bits)			\
983 static ssize_t uvcg_streaming_header_##cname##_show(			\
984 	struct config_item *item, char *page)				\
985 {									\
986 	struct uvcg_streaming_header *sh = to_uvcg_streaming_header(item); \
987 	struct f_uvc_opts *opts;					\
988 	struct config_item *opts_item;					\
989 	struct mutex *su_mutex = &sh->item.ci_group->cg_subsys->su_mutex;\
990 	int result;							\
991 									\
992 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
993 									\
994 	opts_item = sh->item.ci_parent->ci_parent->ci_parent;		\
995 	opts = to_f_uvc_opts(opts_item);				\
996 									\
997 	mutex_lock(&opts->lock);					\
998 	result = sprintf(page, "%u\n", le##bits##_to_cpu(sh->desc.aname));\
999 	mutex_unlock(&opts->lock);					\
1000 									\
1001 	mutex_unlock(su_mutex);						\
1002 	return result;							\
1003 }									\
1004 									\
1005 UVC_ATTR_RO(uvcg_streaming_header_, cname, aname)
1006 
1007 UVCG_STREAMING_HEADER_ATTR(bm_info, bmInfo, 8);
1008 UVCG_STREAMING_HEADER_ATTR(b_terminal_link, bTerminalLink, 8);
1009 UVCG_STREAMING_HEADER_ATTR(b_still_capture_method, bStillCaptureMethod, 8);
1010 UVCG_STREAMING_HEADER_ATTR(b_trigger_support, bTriggerSupport, 8);
1011 UVCG_STREAMING_HEADER_ATTR(b_trigger_usage, bTriggerUsage, 8);
1012 
1013 #undef UVCG_STREAMING_HEADER_ATTR
1014 
1015 static struct configfs_attribute *uvcg_streaming_header_attrs[] = {
1016 	&uvcg_streaming_header_attr_bm_info,
1017 	&uvcg_streaming_header_attr_b_terminal_link,
1018 	&uvcg_streaming_header_attr_b_still_capture_method,
1019 	&uvcg_streaming_header_attr_b_trigger_support,
1020 	&uvcg_streaming_header_attr_b_trigger_usage,
1021 	NULL,
1022 };
1023 
1024 static const struct config_item_type uvcg_streaming_header_type = {
1025 	.ct_item_ops	= &uvcg_streaming_header_item_ops,
1026 	.ct_attrs	= uvcg_streaming_header_attrs,
1027 	.ct_owner	= THIS_MODULE,
1028 };
1029 
1030 static struct config_item
1031 *uvcg_streaming_header_make(struct config_group *group, const char *name)
1032 {
1033 	struct uvcg_streaming_header *h;
1034 
1035 	h = kzalloc(sizeof(*h), GFP_KERNEL);
1036 	if (!h)
1037 		return ERR_PTR(-ENOMEM);
1038 
1039 	INIT_LIST_HEAD(&h->formats);
1040 	h->desc.bDescriptorType		= USB_DT_CS_INTERFACE;
1041 	h->desc.bDescriptorSubType	= UVC_VS_INPUT_HEADER;
1042 	h->desc.bTerminalLink		= 3;
1043 	h->desc.bControlSize		= UVCG_STREAMING_CONTROL_SIZE;
1044 
1045 	config_item_init_type_name(&h->item, name, &uvcg_streaming_header_type);
1046 
1047 	return &h->item;
1048 }
1049 
1050 static struct configfs_group_operations uvcg_streaming_header_grp_ops = {
1051 	.make_item		= uvcg_streaming_header_make,
1052 };
1053 
1054 static const struct uvcg_config_group_type uvcg_streaming_header_grp_type = {
1055 	.type = {
1056 		.ct_item_ops	= &uvcg_config_item_ops,
1057 		.ct_group_ops	= &uvcg_streaming_header_grp_ops,
1058 		.ct_owner	= THIS_MODULE,
1059 	},
1060 	.name = "header",
1061 };
1062 
1063 /* -----------------------------------------------------------------------------
1064  * streaming/<mode>/<format>/<NAME>
1065  */
1066 
1067 struct uvcg_frame {
1068 	struct config_item	item;
1069 	enum uvcg_format_type	fmt_type;
1070 	struct {
1071 		u8	b_length;
1072 		u8	b_descriptor_type;
1073 		u8	b_descriptor_subtype;
1074 		u8	b_frame_index;
1075 		u8	bm_capabilities;
1076 		u16	w_width;
1077 		u16	w_height;
1078 		u32	dw_min_bit_rate;
1079 		u32	dw_max_bit_rate;
1080 		u32	dw_max_video_frame_buffer_size;
1081 		u32	dw_default_frame_interval;
1082 		u8	b_frame_interval_type;
1083 	} __attribute__((packed)) frame;
1084 	u32 *dw_frame_interval;
1085 };
1086 
1087 static struct uvcg_frame *to_uvcg_frame(struct config_item *item)
1088 {
1089 	return container_of(item, struct uvcg_frame, item);
1090 }
1091 
1092 #define UVCG_FRAME_ATTR(cname, aname, bits) \
1093 static ssize_t uvcg_frame_##cname##_show(struct config_item *item, char *page)\
1094 {									\
1095 	struct uvcg_frame *f = to_uvcg_frame(item);			\
1096 	struct f_uvc_opts *opts;					\
1097 	struct config_item *opts_item;					\
1098 	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;\
1099 	int result;							\
1100 									\
1101 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1102 									\
1103 	opts_item = f->item.ci_parent->ci_parent->ci_parent->ci_parent;	\
1104 	opts = to_f_uvc_opts(opts_item);				\
1105 									\
1106 	mutex_lock(&opts->lock);					\
1107 	result = sprintf(page, "%u\n", f->frame.cname);			\
1108 	mutex_unlock(&opts->lock);					\
1109 									\
1110 	mutex_unlock(su_mutex);						\
1111 	return result;							\
1112 }									\
1113 									\
1114 static ssize_t  uvcg_frame_##cname##_store(struct config_item *item,	\
1115 					   const char *page, size_t len)\
1116 {									\
1117 	struct uvcg_frame *f = to_uvcg_frame(item);			\
1118 	struct f_uvc_opts *opts;					\
1119 	struct config_item *opts_item;					\
1120 	struct uvcg_format *fmt;					\
1121 	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;\
1122 	typeof(f->frame.cname) num;					\
1123 	int ret;							\
1124 									\
1125 	ret = kstrtou##bits(page, 0, &num);				\
1126 	if (ret)							\
1127 		return ret;						\
1128 									\
1129 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1130 									\
1131 	opts_item = f->item.ci_parent->ci_parent->ci_parent->ci_parent;	\
1132 	opts = to_f_uvc_opts(opts_item);				\
1133 	fmt = to_uvcg_format(f->item.ci_parent);			\
1134 									\
1135 	mutex_lock(&opts->lock);					\
1136 	if (fmt->linked || opts->refcnt) {				\
1137 		ret = -EBUSY;						\
1138 		goto end;						\
1139 	}								\
1140 									\
1141 	f->frame.cname = num;						\
1142 	ret = len;							\
1143 end:									\
1144 	mutex_unlock(&opts->lock);					\
1145 	mutex_unlock(su_mutex);						\
1146 	return ret;							\
1147 }									\
1148 									\
1149 UVC_ATTR(uvcg_frame_, cname, aname);
1150 
1151 static ssize_t uvcg_frame_b_frame_index_show(struct config_item *item,
1152 					     char *page)
1153 {
1154 	struct uvcg_frame *f = to_uvcg_frame(item);
1155 	struct uvcg_format *fmt;
1156 	struct f_uvc_opts *opts;
1157 	struct config_item *opts_item;
1158 	struct config_item *fmt_item;
1159 	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;
1160 	int result;
1161 
1162 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
1163 
1164 	fmt_item = f->item.ci_parent;
1165 	fmt = to_uvcg_format(fmt_item);
1166 
1167 	if (!fmt->linked) {
1168 		result = -EBUSY;
1169 		goto out;
1170 	}
1171 
1172 	opts_item = fmt_item->ci_parent->ci_parent->ci_parent;
1173 	opts = to_f_uvc_opts(opts_item);
1174 
1175 	mutex_lock(&opts->lock);
1176 	result = sprintf(page, "%u\n", f->frame.b_frame_index);
1177 	mutex_unlock(&opts->lock);
1178 
1179 out:
1180 	mutex_unlock(su_mutex);
1181 	return result;
1182 }
1183 
1184 UVC_ATTR_RO(uvcg_frame_, b_frame_index, bFrameIndex);
1185 
1186 UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, 8);
1187 UVCG_FRAME_ATTR(w_width, wWidth, 16);
1188 UVCG_FRAME_ATTR(w_height, wHeight, 16);
1189 UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, 32);
1190 UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, 32);
1191 UVCG_FRAME_ATTR(dw_max_video_frame_buffer_size, dwMaxVideoFrameBufferSize, 32);
1192 UVCG_FRAME_ATTR(dw_default_frame_interval, dwDefaultFrameInterval, 32);
1193 
1194 #undef UVCG_FRAME_ATTR
1195 
1196 static ssize_t uvcg_frame_dw_frame_interval_show(struct config_item *item,
1197 						 char *page)
1198 {
1199 	struct uvcg_frame *frm = to_uvcg_frame(item);
1200 	struct f_uvc_opts *opts;
1201 	struct config_item *opts_item;
1202 	struct mutex *su_mutex = &frm->item.ci_group->cg_subsys->su_mutex;
1203 	int result, i;
1204 	char *pg = page;
1205 
1206 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
1207 
1208 	opts_item = frm->item.ci_parent->ci_parent->ci_parent->ci_parent;
1209 	opts = to_f_uvc_opts(opts_item);
1210 
1211 	mutex_lock(&opts->lock);
1212 	for (result = 0, i = 0; i < frm->frame.b_frame_interval_type; ++i) {
1213 		result += sprintf(pg, "%u\n", frm->dw_frame_interval[i]);
1214 		pg = page + result;
1215 	}
1216 	mutex_unlock(&opts->lock);
1217 
1218 	mutex_unlock(su_mutex);
1219 	return result;
1220 }
1221 
1222 static inline int __uvcg_count_frm_intrv(char *buf, void *priv)
1223 {
1224 	++*((int *)priv);
1225 	return 0;
1226 }
1227 
1228 static inline int __uvcg_fill_frm_intrv(char *buf, void *priv)
1229 {
1230 	u32 num, **interv;
1231 	int ret;
1232 
1233 	ret = kstrtou32(buf, 0, &num);
1234 	if (ret)
1235 		return ret;
1236 
1237 	interv = priv;
1238 	**interv = num;
1239 	++*interv;
1240 
1241 	return 0;
1242 }
1243 
1244 static int __uvcg_iter_frm_intrv(const char *page, size_t len,
1245 				 int (*fun)(char *, void *), void *priv)
1246 {
1247 	/* sign, base 2 representation, newline, terminator */
1248 	char buf[1 + sizeof(u32) * 8 + 1 + 1];
1249 	const char *pg = page;
1250 	int i, ret;
1251 
1252 	if (!fun)
1253 		return -EINVAL;
1254 
1255 	while (pg - page < len) {
1256 		i = 0;
1257 		while (i < sizeof(buf) && (pg - page < len) &&
1258 				*pg != '\0' && *pg != '\n')
1259 			buf[i++] = *pg++;
1260 		if (i == sizeof(buf))
1261 			return -EINVAL;
1262 		while ((pg - page < len) && (*pg == '\0' || *pg == '\n'))
1263 			++pg;
1264 		buf[i] = '\0';
1265 		ret = fun(buf, priv);
1266 		if (ret)
1267 			return ret;
1268 	}
1269 
1270 	return 0;
1271 }
1272 
1273 static ssize_t uvcg_frame_dw_frame_interval_store(struct config_item *item,
1274 						  const char *page, size_t len)
1275 {
1276 	struct uvcg_frame *ch = to_uvcg_frame(item);
1277 	struct f_uvc_opts *opts;
1278 	struct config_item *opts_item;
1279 	struct uvcg_format *fmt;
1280 	struct mutex *su_mutex = &ch->item.ci_group->cg_subsys->su_mutex;
1281 	int ret = 0, n = 0;
1282 	u32 *frm_intrv, *tmp;
1283 
1284 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
1285 
1286 	opts_item = ch->item.ci_parent->ci_parent->ci_parent->ci_parent;
1287 	opts = to_f_uvc_opts(opts_item);
1288 	fmt = to_uvcg_format(ch->item.ci_parent);
1289 
1290 	mutex_lock(&opts->lock);
1291 	if (fmt->linked || opts->refcnt) {
1292 		ret = -EBUSY;
1293 		goto end;
1294 	}
1295 
1296 	ret = __uvcg_iter_frm_intrv(page, len, __uvcg_count_frm_intrv, &n);
1297 	if (ret)
1298 		goto end;
1299 
1300 	tmp = frm_intrv = kcalloc(n, sizeof(u32), GFP_KERNEL);
1301 	if (!frm_intrv) {
1302 		ret = -ENOMEM;
1303 		goto end;
1304 	}
1305 
1306 	ret = __uvcg_iter_frm_intrv(page, len, __uvcg_fill_frm_intrv, &tmp);
1307 	if (ret) {
1308 		kfree(frm_intrv);
1309 		goto end;
1310 	}
1311 
1312 	kfree(ch->dw_frame_interval);
1313 	ch->dw_frame_interval = frm_intrv;
1314 	ch->frame.b_frame_interval_type = n;
1315 	sort(ch->dw_frame_interval, n, sizeof(*ch->dw_frame_interval),
1316 	     uvcg_config_compare_u32, NULL);
1317 	ret = len;
1318 
1319 end:
1320 	mutex_unlock(&opts->lock);
1321 	mutex_unlock(su_mutex);
1322 	return ret;
1323 }
1324 
1325 UVC_ATTR(uvcg_frame_, dw_frame_interval, dwFrameInterval);
1326 
1327 static struct configfs_attribute *uvcg_frame_attrs[] = {
1328 	&uvcg_frame_attr_b_frame_index,
1329 	&uvcg_frame_attr_bm_capabilities,
1330 	&uvcg_frame_attr_w_width,
1331 	&uvcg_frame_attr_w_height,
1332 	&uvcg_frame_attr_dw_min_bit_rate,
1333 	&uvcg_frame_attr_dw_max_bit_rate,
1334 	&uvcg_frame_attr_dw_max_video_frame_buffer_size,
1335 	&uvcg_frame_attr_dw_default_frame_interval,
1336 	&uvcg_frame_attr_dw_frame_interval,
1337 	NULL,
1338 };
1339 
1340 static const struct config_item_type uvcg_frame_type = {
1341 	.ct_item_ops	= &uvcg_config_item_ops,
1342 	.ct_attrs	= uvcg_frame_attrs,
1343 	.ct_owner	= THIS_MODULE,
1344 };
1345 
1346 static struct config_item *uvcg_frame_make(struct config_group *group,
1347 					   const char *name)
1348 {
1349 	struct uvcg_frame *h;
1350 	struct uvcg_format *fmt;
1351 	struct f_uvc_opts *opts;
1352 	struct config_item *opts_item;
1353 
1354 	h = kzalloc(sizeof(*h), GFP_KERNEL);
1355 	if (!h)
1356 		return ERR_PTR(-ENOMEM);
1357 
1358 	h->frame.b_descriptor_type		= USB_DT_CS_INTERFACE;
1359 	h->frame.b_frame_index			= 1;
1360 	h->frame.w_width			= 640;
1361 	h->frame.w_height			= 360;
1362 	h->frame.dw_min_bit_rate		= 18432000;
1363 	h->frame.dw_max_bit_rate		= 55296000;
1364 	h->frame.dw_max_video_frame_buffer_size	= 460800;
1365 	h->frame.dw_default_frame_interval	= 666666;
1366 
1367 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;
1368 	opts = to_f_uvc_opts(opts_item);
1369 
1370 	mutex_lock(&opts->lock);
1371 	fmt = to_uvcg_format(&group->cg_item);
1372 	if (fmt->type == UVCG_UNCOMPRESSED) {
1373 		h->frame.b_descriptor_subtype = UVC_VS_FRAME_UNCOMPRESSED;
1374 		h->fmt_type = UVCG_UNCOMPRESSED;
1375 	} else if (fmt->type == UVCG_MJPEG) {
1376 		h->frame.b_descriptor_subtype = UVC_VS_FRAME_MJPEG;
1377 		h->fmt_type = UVCG_MJPEG;
1378 	} else {
1379 		mutex_unlock(&opts->lock);
1380 		kfree(h);
1381 		return ERR_PTR(-EINVAL);
1382 	}
1383 	++fmt->num_frames;
1384 	mutex_unlock(&opts->lock);
1385 
1386 	config_item_init_type_name(&h->item, name, &uvcg_frame_type);
1387 
1388 	return &h->item;
1389 }
1390 
1391 static void uvcg_frame_drop(struct config_group *group, struct config_item *item)
1392 {
1393 	struct uvcg_format *fmt;
1394 	struct f_uvc_opts *opts;
1395 	struct config_item *opts_item;
1396 
1397 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;
1398 	opts = to_f_uvc_opts(opts_item);
1399 
1400 	mutex_lock(&opts->lock);
1401 	fmt = to_uvcg_format(&group->cg_item);
1402 	--fmt->num_frames;
1403 	mutex_unlock(&opts->lock);
1404 
1405 	config_item_put(item);
1406 }
1407 
1408 static void uvcg_format_set_indices(struct config_group *fmt)
1409 {
1410 	struct config_item *ci;
1411 	unsigned int i = 1;
1412 
1413 	list_for_each_entry(ci, &fmt->cg_children, ci_entry) {
1414 		struct uvcg_frame *frm;
1415 
1416 		if (ci->ci_type != &uvcg_frame_type)
1417 			continue;
1418 
1419 		frm = to_uvcg_frame(ci);
1420 		frm->frame.b_frame_index = i++;
1421 	}
1422 }
1423 
1424 /* -----------------------------------------------------------------------------
1425  * streaming/uncompressed/<NAME>
1426  */
1427 
1428 struct uvcg_uncompressed {
1429 	struct uvcg_format		fmt;
1430 	struct uvc_format_uncompressed	desc;
1431 };
1432 
1433 static struct uvcg_uncompressed *to_uvcg_uncompressed(struct config_item *item)
1434 {
1435 	return container_of(
1436 		container_of(to_config_group(item), struct uvcg_format, group),
1437 		struct uvcg_uncompressed, fmt);
1438 }
1439 
1440 static struct configfs_group_operations uvcg_uncompressed_group_ops = {
1441 	.make_item		= uvcg_frame_make,
1442 	.drop_item		= uvcg_frame_drop,
1443 };
1444 
1445 static ssize_t uvcg_uncompressed_guid_format_show(struct config_item *item,
1446 							char *page)
1447 {
1448 	struct uvcg_uncompressed *ch = to_uvcg_uncompressed(item);
1449 	struct f_uvc_opts *opts;
1450 	struct config_item *opts_item;
1451 	struct mutex *su_mutex = &ch->fmt.group.cg_subsys->su_mutex;
1452 
1453 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
1454 
1455 	opts_item = ch->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;
1456 	opts = to_f_uvc_opts(opts_item);
1457 
1458 	mutex_lock(&opts->lock);
1459 	memcpy(page, ch->desc.guidFormat, sizeof(ch->desc.guidFormat));
1460 	mutex_unlock(&opts->lock);
1461 
1462 	mutex_unlock(su_mutex);
1463 
1464 	return sizeof(ch->desc.guidFormat);
1465 }
1466 
1467 static ssize_t uvcg_uncompressed_guid_format_store(struct config_item *item,
1468 						   const char *page, size_t len)
1469 {
1470 	struct uvcg_uncompressed *ch = to_uvcg_uncompressed(item);
1471 	struct f_uvc_opts *opts;
1472 	struct config_item *opts_item;
1473 	struct mutex *su_mutex = &ch->fmt.group.cg_subsys->su_mutex;
1474 	int ret;
1475 
1476 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
1477 
1478 	opts_item = ch->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;
1479 	opts = to_f_uvc_opts(opts_item);
1480 
1481 	mutex_lock(&opts->lock);
1482 	if (ch->fmt.linked || opts->refcnt) {
1483 		ret = -EBUSY;
1484 		goto end;
1485 	}
1486 
1487 	memcpy(ch->desc.guidFormat, page,
1488 	       min(sizeof(ch->desc.guidFormat), len));
1489 	ret = sizeof(ch->desc.guidFormat);
1490 
1491 end:
1492 	mutex_unlock(&opts->lock);
1493 	mutex_unlock(su_mutex);
1494 	return ret;
1495 }
1496 
1497 UVC_ATTR(uvcg_uncompressed_, guid_format, guidFormat);
1498 
1499 #define UVCG_UNCOMPRESSED_ATTR_RO(cname, aname, bits)			\
1500 static ssize_t uvcg_uncompressed_##cname##_show(			\
1501 	struct config_item *item, char *page)				\
1502 {									\
1503 	struct uvcg_uncompressed *u = to_uvcg_uncompressed(item);	\
1504 	struct f_uvc_opts *opts;					\
1505 	struct config_item *opts_item;					\
1506 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1507 	int result;							\
1508 									\
1509 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1510 									\
1511 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1512 	opts = to_f_uvc_opts(opts_item);				\
1513 									\
1514 	mutex_lock(&opts->lock);					\
1515 	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
1516 	mutex_unlock(&opts->lock);					\
1517 									\
1518 	mutex_unlock(su_mutex);						\
1519 	return result;							\
1520 }									\
1521 									\
1522 UVC_ATTR_RO(uvcg_uncompressed_, cname, aname);
1523 
1524 #define UVCG_UNCOMPRESSED_ATTR(cname, aname, bits)			\
1525 static ssize_t uvcg_uncompressed_##cname##_show(			\
1526 	struct config_item *item, char *page)				\
1527 {									\
1528 	struct uvcg_uncompressed *u = to_uvcg_uncompressed(item);	\
1529 	struct f_uvc_opts *opts;					\
1530 	struct config_item *opts_item;					\
1531 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1532 	int result;							\
1533 									\
1534 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1535 									\
1536 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1537 	opts = to_f_uvc_opts(opts_item);				\
1538 									\
1539 	mutex_lock(&opts->lock);					\
1540 	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
1541 	mutex_unlock(&opts->lock);					\
1542 									\
1543 	mutex_unlock(su_mutex);						\
1544 	return result;							\
1545 }									\
1546 									\
1547 static ssize_t								\
1548 uvcg_uncompressed_##cname##_store(struct config_item *item,		\
1549 				    const char *page, size_t len)	\
1550 {									\
1551 	struct uvcg_uncompressed *u = to_uvcg_uncompressed(item);	\
1552 	struct f_uvc_opts *opts;					\
1553 	struct config_item *opts_item;					\
1554 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1555 	int ret;							\
1556 	u8 num;								\
1557 									\
1558 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1559 									\
1560 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1561 	opts = to_f_uvc_opts(opts_item);				\
1562 									\
1563 	mutex_lock(&opts->lock);					\
1564 	if (u->fmt.linked || opts->refcnt) {				\
1565 		ret = -EBUSY;						\
1566 		goto end;						\
1567 	}								\
1568 									\
1569 	ret = kstrtou8(page, 0, &num);					\
1570 	if (ret)							\
1571 		goto end;						\
1572 									\
1573 	u->desc.aname = num;						\
1574 	ret = len;							\
1575 end:									\
1576 	mutex_unlock(&opts->lock);					\
1577 	mutex_unlock(su_mutex);						\
1578 	return ret;							\
1579 }									\
1580 									\
1581 UVC_ATTR(uvcg_uncompressed_, cname, aname);
1582 
1583 UVCG_UNCOMPRESSED_ATTR_RO(b_format_index, bFormatIndex, 8);
1584 UVCG_UNCOMPRESSED_ATTR(b_bits_per_pixel, bBitsPerPixel, 8);
1585 UVCG_UNCOMPRESSED_ATTR(b_default_frame_index, bDefaultFrameIndex, 8);
1586 UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, 8);
1587 UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, 8);
1588 UVCG_UNCOMPRESSED_ATTR_RO(bm_interface_flags, bmInterfaceFlags, 8);
1589 
1590 #undef UVCG_UNCOMPRESSED_ATTR
1591 #undef UVCG_UNCOMPRESSED_ATTR_RO
1592 
1593 static inline ssize_t
1594 uvcg_uncompressed_bma_controls_show(struct config_item *item, char *page)
1595 {
1596 	struct uvcg_uncompressed *unc = to_uvcg_uncompressed(item);
1597 	return uvcg_format_bma_controls_show(&unc->fmt, page);
1598 }
1599 
1600 static inline ssize_t
1601 uvcg_uncompressed_bma_controls_store(struct config_item *item,
1602 				     const char *page, size_t len)
1603 {
1604 	struct uvcg_uncompressed *unc = to_uvcg_uncompressed(item);
1605 	return uvcg_format_bma_controls_store(&unc->fmt, page, len);
1606 }
1607 
1608 UVC_ATTR(uvcg_uncompressed_, bma_controls, bmaControls);
1609 
1610 static struct configfs_attribute *uvcg_uncompressed_attrs[] = {
1611 	&uvcg_uncompressed_attr_b_format_index,
1612 	&uvcg_uncompressed_attr_guid_format,
1613 	&uvcg_uncompressed_attr_b_bits_per_pixel,
1614 	&uvcg_uncompressed_attr_b_default_frame_index,
1615 	&uvcg_uncompressed_attr_b_aspect_ratio_x,
1616 	&uvcg_uncompressed_attr_b_aspect_ratio_y,
1617 	&uvcg_uncompressed_attr_bm_interface_flags,
1618 	&uvcg_uncompressed_attr_bma_controls,
1619 	NULL,
1620 };
1621 
1622 static const struct config_item_type uvcg_uncompressed_type = {
1623 	.ct_item_ops	= &uvcg_config_item_ops,
1624 	.ct_group_ops	= &uvcg_uncompressed_group_ops,
1625 	.ct_attrs	= uvcg_uncompressed_attrs,
1626 	.ct_owner	= THIS_MODULE,
1627 };
1628 
1629 static struct config_group *uvcg_uncompressed_make(struct config_group *group,
1630 						   const char *name)
1631 {
1632 	static char guid[] = {
1633 		'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00,
1634 		 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71
1635 	};
1636 	struct uvcg_uncompressed *h;
1637 
1638 	h = kzalloc(sizeof(*h), GFP_KERNEL);
1639 	if (!h)
1640 		return ERR_PTR(-ENOMEM);
1641 
1642 	h->desc.bLength			= UVC_DT_FORMAT_UNCOMPRESSED_SIZE;
1643 	h->desc.bDescriptorType		= USB_DT_CS_INTERFACE;
1644 	h->desc.bDescriptorSubType	= UVC_VS_FORMAT_UNCOMPRESSED;
1645 	memcpy(h->desc.guidFormat, guid, sizeof(guid));
1646 	h->desc.bBitsPerPixel		= 16;
1647 	h->desc.bDefaultFrameIndex	= 1;
1648 	h->desc.bAspectRatioX		= 0;
1649 	h->desc.bAspectRatioY		= 0;
1650 	h->desc.bmInterfaceFlags	= 0;
1651 	h->desc.bCopyProtect		= 0;
1652 
1653 	h->fmt.type = UVCG_UNCOMPRESSED;
1654 	config_group_init_type_name(&h->fmt.group, name,
1655 				    &uvcg_uncompressed_type);
1656 
1657 	return &h->fmt.group;
1658 }
1659 
1660 static struct configfs_group_operations uvcg_uncompressed_grp_ops = {
1661 	.make_group		= uvcg_uncompressed_make,
1662 };
1663 
1664 static const struct uvcg_config_group_type uvcg_uncompressed_grp_type = {
1665 	.type = {
1666 		.ct_item_ops	= &uvcg_config_item_ops,
1667 		.ct_group_ops	= &uvcg_uncompressed_grp_ops,
1668 		.ct_owner	= THIS_MODULE,
1669 	},
1670 	.name = "uncompressed",
1671 };
1672 
1673 /* -----------------------------------------------------------------------------
1674  * streaming/mjpeg/<NAME>
1675  */
1676 
1677 struct uvcg_mjpeg {
1678 	struct uvcg_format		fmt;
1679 	struct uvc_format_mjpeg		desc;
1680 };
1681 
1682 static struct uvcg_mjpeg *to_uvcg_mjpeg(struct config_item *item)
1683 {
1684 	return container_of(
1685 		container_of(to_config_group(item), struct uvcg_format, group),
1686 		struct uvcg_mjpeg, fmt);
1687 }
1688 
1689 static struct configfs_group_operations uvcg_mjpeg_group_ops = {
1690 	.make_item		= uvcg_frame_make,
1691 	.drop_item		= uvcg_frame_drop,
1692 };
1693 
1694 #define UVCG_MJPEG_ATTR_RO(cname, aname, bits)				\
1695 static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
1696 {									\
1697 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);			\
1698 	struct f_uvc_opts *opts;					\
1699 	struct config_item *opts_item;					\
1700 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1701 	int result;							\
1702 									\
1703 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1704 									\
1705 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1706 	opts = to_f_uvc_opts(opts_item);				\
1707 									\
1708 	mutex_lock(&opts->lock);					\
1709 	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
1710 	mutex_unlock(&opts->lock);					\
1711 									\
1712 	mutex_unlock(su_mutex);						\
1713 	return result;							\
1714 }									\
1715 									\
1716 UVC_ATTR_RO(uvcg_mjpeg_, cname, aname)
1717 
1718 #define UVCG_MJPEG_ATTR(cname, aname, bits)				\
1719 static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
1720 {									\
1721 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);			\
1722 	struct f_uvc_opts *opts;					\
1723 	struct config_item *opts_item;					\
1724 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1725 	int result;							\
1726 									\
1727 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1728 									\
1729 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1730 	opts = to_f_uvc_opts(opts_item);				\
1731 									\
1732 	mutex_lock(&opts->lock);					\
1733 	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
1734 	mutex_unlock(&opts->lock);					\
1735 									\
1736 	mutex_unlock(su_mutex);						\
1737 	return result;							\
1738 }									\
1739 									\
1740 static ssize_t								\
1741 uvcg_mjpeg_##cname##_store(struct config_item *item,			\
1742 			   const char *page, size_t len)		\
1743 {									\
1744 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);			\
1745 	struct f_uvc_opts *opts;					\
1746 	struct config_item *opts_item;					\
1747 	struct mutex *su_mutex = &u->fmt.group.cg_subsys->su_mutex;	\
1748 	int ret;							\
1749 	u8 num;								\
1750 									\
1751 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1752 									\
1753 	opts_item = u->fmt.group.cg_item.ci_parent->ci_parent->ci_parent;\
1754 	opts = to_f_uvc_opts(opts_item);				\
1755 									\
1756 	mutex_lock(&opts->lock);					\
1757 	if (u->fmt.linked || opts->refcnt) {				\
1758 		ret = -EBUSY;						\
1759 		goto end;						\
1760 	}								\
1761 									\
1762 	ret = kstrtou8(page, 0, &num);					\
1763 	if (ret)							\
1764 		goto end;						\
1765 									\
1766 	u->desc.aname = num;						\
1767 	ret = len;							\
1768 end:									\
1769 	mutex_unlock(&opts->lock);					\
1770 	mutex_unlock(su_mutex);						\
1771 	return ret;							\
1772 }									\
1773 									\
1774 UVC_ATTR(uvcg_mjpeg_, cname, aname)
1775 
1776 UVCG_MJPEG_ATTR_RO(b_format_index, bFormatIndex, 8);
1777 UVCG_MJPEG_ATTR(b_default_frame_index, bDefaultFrameIndex, 8);
1778 UVCG_MJPEG_ATTR_RO(bm_flags, bmFlags, 8);
1779 UVCG_MJPEG_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, 8);
1780 UVCG_MJPEG_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, 8);
1781 UVCG_MJPEG_ATTR_RO(bm_interface_flags, bmInterfaceFlags, 8);
1782 
1783 #undef UVCG_MJPEG_ATTR
1784 #undef UVCG_MJPEG_ATTR_RO
1785 
1786 static inline ssize_t
1787 uvcg_mjpeg_bma_controls_show(struct config_item *item, char *page)
1788 {
1789 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);
1790 	return uvcg_format_bma_controls_show(&u->fmt, page);
1791 }
1792 
1793 static inline ssize_t
1794 uvcg_mjpeg_bma_controls_store(struct config_item *item,
1795 				     const char *page, size_t len)
1796 {
1797 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);
1798 	return uvcg_format_bma_controls_store(&u->fmt, page, len);
1799 }
1800 
1801 UVC_ATTR(uvcg_mjpeg_, bma_controls, bmaControls);
1802 
1803 static struct configfs_attribute *uvcg_mjpeg_attrs[] = {
1804 	&uvcg_mjpeg_attr_b_format_index,
1805 	&uvcg_mjpeg_attr_b_default_frame_index,
1806 	&uvcg_mjpeg_attr_bm_flags,
1807 	&uvcg_mjpeg_attr_b_aspect_ratio_x,
1808 	&uvcg_mjpeg_attr_b_aspect_ratio_y,
1809 	&uvcg_mjpeg_attr_bm_interface_flags,
1810 	&uvcg_mjpeg_attr_bma_controls,
1811 	NULL,
1812 };
1813 
1814 static const struct config_item_type uvcg_mjpeg_type = {
1815 	.ct_item_ops	= &uvcg_config_item_ops,
1816 	.ct_group_ops	= &uvcg_mjpeg_group_ops,
1817 	.ct_attrs	= uvcg_mjpeg_attrs,
1818 	.ct_owner	= THIS_MODULE,
1819 };
1820 
1821 static struct config_group *uvcg_mjpeg_make(struct config_group *group,
1822 						   const char *name)
1823 {
1824 	struct uvcg_mjpeg *h;
1825 
1826 	h = kzalloc(sizeof(*h), GFP_KERNEL);
1827 	if (!h)
1828 		return ERR_PTR(-ENOMEM);
1829 
1830 	h->desc.bLength			= UVC_DT_FORMAT_MJPEG_SIZE;
1831 	h->desc.bDescriptorType		= USB_DT_CS_INTERFACE;
1832 	h->desc.bDescriptorSubType	= UVC_VS_FORMAT_MJPEG;
1833 	h->desc.bDefaultFrameIndex	= 1;
1834 	h->desc.bAspectRatioX		= 0;
1835 	h->desc.bAspectRatioY		= 0;
1836 	h->desc.bmInterfaceFlags	= 0;
1837 	h->desc.bCopyProtect		= 0;
1838 
1839 	h->fmt.type = UVCG_MJPEG;
1840 	config_group_init_type_name(&h->fmt.group, name,
1841 				    &uvcg_mjpeg_type);
1842 
1843 	return &h->fmt.group;
1844 }
1845 
1846 static struct configfs_group_operations uvcg_mjpeg_grp_ops = {
1847 	.make_group		= uvcg_mjpeg_make,
1848 };
1849 
1850 static const struct uvcg_config_group_type uvcg_mjpeg_grp_type = {
1851 	.type = {
1852 		.ct_item_ops	= &uvcg_config_item_ops,
1853 		.ct_group_ops	= &uvcg_mjpeg_grp_ops,
1854 		.ct_owner	= THIS_MODULE,
1855 	},
1856 	.name = "mjpeg",
1857 };
1858 
1859 /* -----------------------------------------------------------------------------
1860  * streaming/color_matching/default
1861  */
1862 
1863 #define UVCG_DEFAULT_COLOR_MATCHING_ATTR(cname, aname, bits)		\
1864 static ssize_t uvcg_default_color_matching_##cname##_show(		\
1865 	struct config_item *item, char *page)				\
1866 {									\
1867 	struct config_group *group = to_config_group(item);		\
1868 	struct f_uvc_opts *opts;					\
1869 	struct config_item *opts_item;					\
1870 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
1871 	struct uvc_color_matching_descriptor *cd;			\
1872 	int result;							\
1873 									\
1874 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
1875 									\
1876 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;	\
1877 	opts = to_f_uvc_opts(opts_item);				\
1878 	cd = &opts->uvc_color_matching;					\
1879 									\
1880 	mutex_lock(&opts->lock);					\
1881 	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
1882 	mutex_unlock(&opts->lock);					\
1883 									\
1884 	mutex_unlock(su_mutex);						\
1885 	return result;							\
1886 }									\
1887 									\
1888 UVC_ATTR_RO(uvcg_default_color_matching_, cname, aname)
1889 
1890 UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_color_primaries, bColorPrimaries, 8);
1891 UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_transfer_characteristics,
1892 				 bTransferCharacteristics, 8);
1893 UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_matrix_coefficients, bMatrixCoefficients, 8);
1894 
1895 #undef UVCG_DEFAULT_COLOR_MATCHING_ATTR
1896 
1897 static struct configfs_attribute *uvcg_default_color_matching_attrs[] = {
1898 	&uvcg_default_color_matching_attr_b_color_primaries,
1899 	&uvcg_default_color_matching_attr_b_transfer_characteristics,
1900 	&uvcg_default_color_matching_attr_b_matrix_coefficients,
1901 	NULL,
1902 };
1903 
1904 static const struct uvcg_config_group_type uvcg_default_color_matching_type = {
1905 	.type = {
1906 		.ct_item_ops	= &uvcg_config_item_ops,
1907 		.ct_attrs	= uvcg_default_color_matching_attrs,
1908 		.ct_owner	= THIS_MODULE,
1909 	},
1910 	.name = "default",
1911 };
1912 
1913 /* -----------------------------------------------------------------------------
1914  * streaming/color_matching
1915  */
1916 
1917 static const struct uvcg_config_group_type uvcg_color_matching_grp_type = {
1918 	.type = {
1919 		.ct_item_ops	= &uvcg_config_item_ops,
1920 		.ct_owner	= THIS_MODULE,
1921 	},
1922 	.name = "color_matching",
1923 	.children = (const struct uvcg_config_group_type*[]) {
1924 		&uvcg_default_color_matching_type,
1925 		NULL,
1926 	},
1927 };
1928 
1929 /* -----------------------------------------------------------------------------
1930  * streaming/class/{fs|hs|ss}
1931  */
1932 
1933 struct uvcg_streaming_class_group {
1934 	struct config_group group;
1935 	const char *name;
1936 };
1937 
1938 static inline struct uvc_descriptor_header
1939 ***__uvcg_get_stream_class_arr(struct config_item *i, struct f_uvc_opts *o)
1940 {
1941 	struct uvcg_streaming_class_group *group =
1942 		container_of(i, struct uvcg_streaming_class_group,
1943 			     group.cg_item);
1944 
1945 	if (!strcmp(group->name, "fs"))
1946 		return &o->uvc_fs_streaming_cls;
1947 
1948 	if (!strcmp(group->name, "hs"))
1949 		return &o->uvc_hs_streaming_cls;
1950 
1951 	if (!strcmp(group->name, "ss"))
1952 		return &o->uvc_ss_streaming_cls;
1953 
1954 	return NULL;
1955 }
1956 
1957 enum uvcg_strm_type {
1958 	UVCG_HEADER = 0,
1959 	UVCG_FORMAT,
1960 	UVCG_FRAME
1961 };
1962 
1963 /*
1964  * Iterate over a hierarchy of streaming descriptors' config items.
1965  * The items are created by the user with configfs.
1966  *
1967  * It "processes" the header pointed to by @priv1, then for each format
1968  * that follows the header "processes" the format itself and then for
1969  * each frame inside a format "processes" the frame.
1970  *
1971  * As a "processing" function the @fun is used.
1972  *
1973  * __uvcg_iter_strm_cls() is used in two context: first, to calculate
1974  * the amount of memory needed for an array of streaming descriptors
1975  * and second, to actually fill the array.
1976  *
1977  * @h: streaming header pointer
1978  * @priv2: an "inout" parameter (the caller might want to see the changes to it)
1979  * @priv3: an "inout" parameter (the caller might want to see the changes to it)
1980  * @fun: callback function for processing each level of the hierarchy
1981  */
1982 static int __uvcg_iter_strm_cls(struct uvcg_streaming_header *h,
1983 	void *priv2, void *priv3,
1984 	int (*fun)(void *, void *, void *, int, enum uvcg_strm_type type))
1985 {
1986 	struct uvcg_format_ptr *f;
1987 	struct config_group *grp;
1988 	struct config_item *item;
1989 	struct uvcg_frame *frm;
1990 	int ret, i, j;
1991 
1992 	if (!fun)
1993 		return -EINVAL;
1994 
1995 	i = j = 0;
1996 	ret = fun(h, priv2, priv3, 0, UVCG_HEADER);
1997 	if (ret)
1998 		return ret;
1999 	list_for_each_entry(f, &h->formats, entry) {
2000 		ret = fun(f->fmt, priv2, priv3, i++, UVCG_FORMAT);
2001 		if (ret)
2002 			return ret;
2003 		grp = &f->fmt->group;
2004 		list_for_each_entry(item, &grp->cg_children, ci_entry) {
2005 			frm = to_uvcg_frame(item);
2006 			ret = fun(frm, priv2, priv3, j++, UVCG_FRAME);
2007 			if (ret)
2008 				return ret;
2009 		}
2010 	}
2011 
2012 	return ret;
2013 }
2014 
2015 /*
2016  * Count how many bytes are needed for an array of streaming descriptors.
2017  *
2018  * @priv1: pointer to a header, format or frame
2019  * @priv2: inout parameter, accumulated size of the array
2020  * @priv3: inout parameter, accumulated number of the array elements
2021  * @n: unused, this function's prototype must match @fun in __uvcg_iter_strm_cls
2022  */
2023 static int __uvcg_cnt_strm(void *priv1, void *priv2, void *priv3, int n,
2024 			   enum uvcg_strm_type type)
2025 {
2026 	size_t *size = priv2;
2027 	size_t *count = priv3;
2028 
2029 	switch (type) {
2030 	case UVCG_HEADER: {
2031 		struct uvcg_streaming_header *h = priv1;
2032 
2033 		*size += sizeof(h->desc);
2034 		/* bmaControls */
2035 		*size += h->num_fmt * UVCG_STREAMING_CONTROL_SIZE;
2036 	}
2037 	break;
2038 	case UVCG_FORMAT: {
2039 		struct uvcg_format *fmt = priv1;
2040 
2041 		if (fmt->type == UVCG_UNCOMPRESSED) {
2042 			struct uvcg_uncompressed *u =
2043 				container_of(fmt, struct uvcg_uncompressed,
2044 					     fmt);
2045 
2046 			*size += sizeof(u->desc);
2047 		} else if (fmt->type == UVCG_MJPEG) {
2048 			struct uvcg_mjpeg *m =
2049 				container_of(fmt, struct uvcg_mjpeg, fmt);
2050 
2051 			*size += sizeof(m->desc);
2052 		} else {
2053 			return -EINVAL;
2054 		}
2055 	}
2056 	break;
2057 	case UVCG_FRAME: {
2058 		struct uvcg_frame *frm = priv1;
2059 		int sz = sizeof(frm->dw_frame_interval);
2060 
2061 		*size += sizeof(frm->frame);
2062 		*size += frm->frame.b_frame_interval_type * sz;
2063 	}
2064 	break;
2065 	}
2066 
2067 	++*count;
2068 
2069 	return 0;
2070 }
2071 
2072 /*
2073  * Fill an array of streaming descriptors.
2074  *
2075  * @priv1: pointer to a header, format or frame
2076  * @priv2: inout parameter, pointer into a block of memory
2077  * @priv3: inout parameter, pointer to a 2-dimensional array
2078  */
2079 static int __uvcg_fill_strm(void *priv1, void *priv2, void *priv3, int n,
2080 			    enum uvcg_strm_type type)
2081 {
2082 	void **dest = priv2;
2083 	struct uvc_descriptor_header ***array = priv3;
2084 	size_t sz;
2085 
2086 	**array = *dest;
2087 	++*array;
2088 
2089 	switch (type) {
2090 	case UVCG_HEADER: {
2091 		struct uvc_input_header_descriptor *ihdr = *dest;
2092 		struct uvcg_streaming_header *h = priv1;
2093 		struct uvcg_format_ptr *f;
2094 
2095 		memcpy(*dest, &h->desc, sizeof(h->desc));
2096 		*dest += sizeof(h->desc);
2097 		sz = UVCG_STREAMING_CONTROL_SIZE;
2098 		list_for_each_entry(f, &h->formats, entry) {
2099 			memcpy(*dest, f->fmt->bmaControls, sz);
2100 			*dest += sz;
2101 		}
2102 		ihdr->bLength = sizeof(h->desc) + h->num_fmt * sz;
2103 		ihdr->bNumFormats = h->num_fmt;
2104 	}
2105 	break;
2106 	case UVCG_FORMAT: {
2107 		struct uvcg_format *fmt = priv1;
2108 
2109 		if (fmt->type == UVCG_UNCOMPRESSED) {
2110 			struct uvcg_uncompressed *u =
2111 				container_of(fmt, struct uvcg_uncompressed,
2112 					     fmt);
2113 
2114 			u->desc.bFormatIndex = n + 1;
2115 			u->desc.bNumFrameDescriptors = fmt->num_frames;
2116 			memcpy(*dest, &u->desc, sizeof(u->desc));
2117 			*dest += sizeof(u->desc);
2118 		} else if (fmt->type == UVCG_MJPEG) {
2119 			struct uvcg_mjpeg *m =
2120 				container_of(fmt, struct uvcg_mjpeg, fmt);
2121 
2122 			m->desc.bFormatIndex = n + 1;
2123 			m->desc.bNumFrameDescriptors = fmt->num_frames;
2124 			memcpy(*dest, &m->desc, sizeof(m->desc));
2125 			*dest += sizeof(m->desc);
2126 		} else {
2127 			return -EINVAL;
2128 		}
2129 	}
2130 	break;
2131 	case UVCG_FRAME: {
2132 		struct uvcg_frame *frm = priv1;
2133 		struct uvc_descriptor_header *h = *dest;
2134 
2135 		sz = sizeof(frm->frame);
2136 		memcpy(*dest, &frm->frame, sz);
2137 		*dest += sz;
2138 		sz = frm->frame.b_frame_interval_type *
2139 			sizeof(*frm->dw_frame_interval);
2140 		memcpy(*dest, frm->dw_frame_interval, sz);
2141 		*dest += sz;
2142 		if (frm->fmt_type == UVCG_UNCOMPRESSED)
2143 			h->bLength = UVC_DT_FRAME_UNCOMPRESSED_SIZE(
2144 				frm->frame.b_frame_interval_type);
2145 		else if (frm->fmt_type == UVCG_MJPEG)
2146 			h->bLength = UVC_DT_FRAME_MJPEG_SIZE(
2147 				frm->frame.b_frame_interval_type);
2148 	}
2149 	break;
2150 	}
2151 
2152 	return 0;
2153 }
2154 
2155 static int uvcg_streaming_class_allow_link(struct config_item *src,
2156 					   struct config_item *target)
2157 {
2158 	struct config_item *streaming, *header;
2159 	struct f_uvc_opts *opts;
2160 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
2161 	struct uvc_descriptor_header ***class_array, **cl_arr;
2162 	struct uvcg_streaming_header *target_hdr;
2163 	void *data, *data_save;
2164 	size_t size = 0, count = 0;
2165 	int ret = -EINVAL;
2166 
2167 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
2168 
2169 	streaming = src->ci_parent->ci_parent;
2170 	header = config_group_find_item(to_config_group(streaming), "header");
2171 	if (!header || target->ci_parent != header)
2172 		goto out;
2173 
2174 	opts = to_f_uvc_opts(streaming->ci_parent);
2175 
2176 	mutex_lock(&opts->lock);
2177 
2178 	class_array = __uvcg_get_stream_class_arr(src, opts);
2179 	if (!class_array || *class_array || opts->refcnt) {
2180 		ret = -EBUSY;
2181 		goto unlock;
2182 	}
2183 
2184 	target_hdr = to_uvcg_streaming_header(target);
2185 	ret = __uvcg_iter_strm_cls(target_hdr, &size, &count, __uvcg_cnt_strm);
2186 	if (ret)
2187 		goto unlock;
2188 
2189 	count += 2; /* color_matching, NULL */
2190 	*class_array = kcalloc(count, sizeof(void *), GFP_KERNEL);
2191 	if (!*class_array) {
2192 		ret = -ENOMEM;
2193 		goto unlock;
2194 	}
2195 
2196 	data = data_save = kzalloc(size, GFP_KERNEL);
2197 	if (!data) {
2198 		kfree(*class_array);
2199 		*class_array = NULL;
2200 		ret = -ENOMEM;
2201 		goto unlock;
2202 	}
2203 	cl_arr = *class_array;
2204 	ret = __uvcg_iter_strm_cls(target_hdr, &data, &cl_arr,
2205 				   __uvcg_fill_strm);
2206 	if (ret) {
2207 		kfree(*class_array);
2208 		*class_array = NULL;
2209 		/*
2210 		 * __uvcg_fill_strm() called from __uvcg_iter_stream_cls()
2211 		 * might have advanced the "data", so use a backup copy
2212 		 */
2213 		kfree(data_save);
2214 		goto unlock;
2215 	}
2216 	*cl_arr = (struct uvc_descriptor_header *)&opts->uvc_color_matching;
2217 
2218 	++target_hdr->linked;
2219 	ret = 0;
2220 
2221 unlock:
2222 	mutex_unlock(&opts->lock);
2223 out:
2224 	config_item_put(header);
2225 	mutex_unlock(su_mutex);
2226 	return ret;
2227 }
2228 
2229 static void uvcg_streaming_class_drop_link(struct config_item *src,
2230 					  struct config_item *target)
2231 {
2232 	struct config_item *streaming, *header;
2233 	struct f_uvc_opts *opts;
2234 	struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex;
2235 	struct uvc_descriptor_header ***class_array;
2236 	struct uvcg_streaming_header *target_hdr;
2237 
2238 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
2239 
2240 	streaming = src->ci_parent->ci_parent;
2241 	header = config_group_find_item(to_config_group(streaming), "header");
2242 	if (!header || target->ci_parent != header)
2243 		goto out;
2244 
2245 	opts = to_f_uvc_opts(streaming->ci_parent);
2246 
2247 	mutex_lock(&opts->lock);
2248 
2249 	class_array = __uvcg_get_stream_class_arr(src, opts);
2250 	if (!class_array || !*class_array)
2251 		goto unlock;
2252 
2253 	if (opts->refcnt)
2254 		goto unlock;
2255 
2256 	target_hdr = to_uvcg_streaming_header(target);
2257 	--target_hdr->linked;
2258 	kfree(**class_array);
2259 	kfree(*class_array);
2260 	*class_array = NULL;
2261 
2262 unlock:
2263 	mutex_unlock(&opts->lock);
2264 out:
2265 	config_item_put(header);
2266 	mutex_unlock(su_mutex);
2267 }
2268 
2269 static struct configfs_item_operations uvcg_streaming_class_item_ops = {
2270 	.release	= uvcg_config_item_release,
2271 	.allow_link	= uvcg_streaming_class_allow_link,
2272 	.drop_link	= uvcg_streaming_class_drop_link,
2273 };
2274 
2275 static const struct config_item_type uvcg_streaming_class_type = {
2276 	.ct_item_ops	= &uvcg_streaming_class_item_ops,
2277 	.ct_owner	= THIS_MODULE,
2278 };
2279 
2280 /* -----------------------------------------------------------------------------
2281  * streaming/class
2282  */
2283 
2284 static int uvcg_streaming_class_create_children(struct config_group *parent)
2285 {
2286 	static const char * const names[] = { "fs", "hs", "ss" };
2287 	unsigned int i;
2288 
2289 	for (i = 0; i < ARRAY_SIZE(names); ++i) {
2290 		struct uvcg_streaming_class_group *group;
2291 
2292 		group = kzalloc(sizeof(*group), GFP_KERNEL);
2293 		if (!group)
2294 			return -ENOMEM;
2295 
2296 		group->name = names[i];
2297 
2298 		config_group_init_type_name(&group->group, group->name,
2299 					    &uvcg_streaming_class_type);
2300 		configfs_add_default_group(&group->group, parent);
2301 	}
2302 
2303 	return 0;
2304 }
2305 
2306 static const struct uvcg_config_group_type uvcg_streaming_class_grp_type = {
2307 	.type = {
2308 		.ct_item_ops	= &uvcg_config_item_ops,
2309 		.ct_owner	= THIS_MODULE,
2310 	},
2311 	.name = "class",
2312 	.create_children = uvcg_streaming_class_create_children,
2313 };
2314 
2315 /* -----------------------------------------------------------------------------
2316  * streaming
2317  */
2318 
2319 static ssize_t uvcg_default_streaming_b_interface_number_show(
2320 	struct config_item *item, char *page)
2321 {
2322 	struct config_group *group = to_config_group(item);
2323 	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
2324 	struct config_item *opts_item;
2325 	struct f_uvc_opts *opts;
2326 	int result = 0;
2327 
2328 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
2329 
2330 	opts_item = item->ci_parent;
2331 	opts = to_f_uvc_opts(opts_item);
2332 
2333 	mutex_lock(&opts->lock);
2334 	result += sprintf(page, "%u\n", opts->streaming_interface);
2335 	mutex_unlock(&opts->lock);
2336 
2337 	mutex_unlock(su_mutex);
2338 
2339 	return result;
2340 }
2341 
2342 UVC_ATTR_RO(uvcg_default_streaming_, b_interface_number, bInterfaceNumber);
2343 
2344 static struct configfs_attribute *uvcg_default_streaming_attrs[] = {
2345 	&uvcg_default_streaming_attr_b_interface_number,
2346 	NULL,
2347 };
2348 
2349 static const struct uvcg_config_group_type uvcg_streaming_grp_type = {
2350 	.type = {
2351 		.ct_item_ops	= &uvcg_config_item_ops,
2352 		.ct_attrs	= uvcg_default_streaming_attrs,
2353 		.ct_owner	= THIS_MODULE,
2354 	},
2355 	.name = "streaming",
2356 	.children = (const struct uvcg_config_group_type*[]) {
2357 		&uvcg_streaming_header_grp_type,
2358 		&uvcg_uncompressed_grp_type,
2359 		&uvcg_mjpeg_grp_type,
2360 		&uvcg_color_matching_grp_type,
2361 		&uvcg_streaming_class_grp_type,
2362 		NULL,
2363 	},
2364 };
2365 
2366 /* -----------------------------------------------------------------------------
2367  * UVC function
2368  */
2369 
2370 static void uvc_func_item_release(struct config_item *item)
2371 {
2372 	struct f_uvc_opts *opts = to_f_uvc_opts(item);
2373 
2374 	uvcg_config_remove_children(to_config_group(item));
2375 	usb_put_function_instance(&opts->func_inst);
2376 }
2377 
2378 static struct configfs_item_operations uvc_func_item_ops = {
2379 	.release	= uvc_func_item_release,
2380 };
2381 
2382 #define UVCG_OPTS_ATTR(cname, aname, limit)				\
2383 static ssize_t f_uvc_opts_##cname##_show(				\
2384 	struct config_item *item, char *page)				\
2385 {									\
2386 	struct f_uvc_opts *opts = to_f_uvc_opts(item);			\
2387 	int result;							\
2388 									\
2389 	mutex_lock(&opts->lock);					\
2390 	result = sprintf(page, "%u\n", opts->cname);			\
2391 	mutex_unlock(&opts->lock);					\
2392 									\
2393 	return result;							\
2394 }									\
2395 									\
2396 static ssize_t								\
2397 f_uvc_opts_##cname##_store(struct config_item *item,			\
2398 			   const char *page, size_t len)		\
2399 {									\
2400 	struct f_uvc_opts *opts = to_f_uvc_opts(item);			\
2401 	unsigned int num;						\
2402 	int ret;							\
2403 									\
2404 	mutex_lock(&opts->lock);					\
2405 	if (opts->refcnt) {						\
2406 		ret = -EBUSY;						\
2407 		goto end;						\
2408 	}								\
2409 									\
2410 	ret = kstrtouint(page, 0, &num);				\
2411 	if (ret)							\
2412 		goto end;						\
2413 									\
2414 	if (num > limit) {						\
2415 		ret = -EINVAL;						\
2416 		goto end;						\
2417 	}								\
2418 	opts->cname = num;						\
2419 	ret = len;							\
2420 end:									\
2421 	mutex_unlock(&opts->lock);					\
2422 	return ret;							\
2423 }									\
2424 									\
2425 UVC_ATTR(f_uvc_opts_, cname, cname)
2426 
2427 UVCG_OPTS_ATTR(streaming_interval, streaming_interval, 16);
2428 UVCG_OPTS_ATTR(streaming_maxpacket, streaming_maxpacket, 3072);
2429 UVCG_OPTS_ATTR(streaming_maxburst, streaming_maxburst, 15);
2430 
2431 #undef UVCG_OPTS_ATTR
2432 
2433 static struct configfs_attribute *uvc_attrs[] = {
2434 	&f_uvc_opts_attr_streaming_interval,
2435 	&f_uvc_opts_attr_streaming_maxpacket,
2436 	&f_uvc_opts_attr_streaming_maxburst,
2437 	NULL,
2438 };
2439 
2440 static const struct uvcg_config_group_type uvc_func_type = {
2441 	.type = {
2442 		.ct_item_ops	= &uvc_func_item_ops,
2443 		.ct_attrs	= uvc_attrs,
2444 		.ct_owner	= THIS_MODULE,
2445 	},
2446 	.name = "",
2447 	.children = (const struct uvcg_config_group_type*[]) {
2448 		&uvcg_control_grp_type,
2449 		&uvcg_streaming_grp_type,
2450 		NULL,
2451 	},
2452 };
2453 
2454 int uvcg_attach_configfs(struct f_uvc_opts *opts)
2455 {
2456 	int ret;
2457 
2458 	config_group_init_type_name(&opts->func_inst.group, uvc_func_type.name,
2459 				    &uvc_func_type.type);
2460 
2461 	ret = uvcg_config_create_children(&opts->func_inst.group,
2462 					  &uvc_func_type);
2463 	if (ret < 0)
2464 		config_group_put(&opts->func_inst.group);
2465 
2466 	return ret;
2467 }
2468