xref: /linux/drivers/usb/gadget/configfs.c (revision 0e685c3e7158d35626d6d76b9f859eae806d87fa)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/configfs.h>
3 #include <linux/module.h>
4 #include <linux/slab.h>
5 #include <linux/device.h>
6 #include <linux/kstrtox.h>
7 #include <linux/nls.h>
8 #include <linux/usb/composite.h>
9 #include <linux/usb/gadget_configfs.h>
10 #include <linux/usb/webusb.h>
11 #include "configfs.h"
12 #include "u_f.h"
13 #include "u_os_desc.h"
14 
15 int check_user_usb_string(const char *name,
16 		struct usb_gadget_strings *stringtab_dev)
17 {
18 	u16 num;
19 	int ret;
20 
21 	ret = kstrtou16(name, 0, &num);
22 	if (ret)
23 		return ret;
24 
25 	if (!usb_validate_langid(num))
26 		return -EINVAL;
27 
28 	stringtab_dev->language = num;
29 	return 0;
30 }
31 
32 #define MAX_NAME_LEN	40
33 #define MAX_USB_STRING_LANGS 2
34 
35 static const struct usb_descriptor_header *otg_desc[2];
36 
37 struct gadget_info {
38 	struct config_group group;
39 	struct config_group functions_group;
40 	struct config_group configs_group;
41 	struct config_group strings_group;
42 	struct config_group os_desc_group;
43 	struct config_group webusb_group;
44 
45 	struct mutex lock;
46 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
47 	struct list_head string_list;
48 	struct list_head available_func;
49 
50 	struct usb_composite_driver composite;
51 	struct usb_composite_dev cdev;
52 	bool use_os_desc;
53 	char b_vendor_code;
54 	char qw_sign[OS_STRING_QW_SIGN_LEN];
55 	bool use_webusb;
56 	u16 bcd_webusb_version;
57 	u8 b_webusb_vendor_code;
58 	char landing_page[WEBUSB_URL_RAW_MAX_LENGTH];
59 
60 	spinlock_t spinlock;
61 	bool unbind;
62 };
63 
64 static inline struct gadget_info *to_gadget_info(struct config_item *item)
65 {
66 	return container_of(to_config_group(item), struct gadget_info, group);
67 }
68 
69 struct config_usb_cfg {
70 	struct config_group group;
71 	struct config_group strings_group;
72 	struct list_head string_list;
73 	struct usb_configuration c;
74 	struct list_head func_list;
75 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
76 };
77 
78 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
79 {
80 	return container_of(to_config_group(item), struct config_usb_cfg,
81 			group);
82 }
83 
84 static inline struct gadget_info *cfg_to_gadget_info(struct config_usb_cfg *cfg)
85 {
86 	return container_of(cfg->c.cdev, struct gadget_info, cdev);
87 }
88 
89 struct gadget_language {
90 	struct usb_gadget_strings stringtab_dev;
91 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
92 	char *manufacturer;
93 	char *product;
94 	char *serialnumber;
95 
96 	struct config_group group;
97 	struct list_head list;
98 	struct list_head gadget_strings;
99 	unsigned int nstrings;
100 };
101 
102 struct gadget_config_name {
103 	struct usb_gadget_strings stringtab_dev;
104 	struct usb_string strings;
105 	char *configuration;
106 
107 	struct config_group group;
108 	struct list_head list;
109 };
110 
111 #define USB_MAX_STRING_WITH_NULL_LEN	(USB_MAX_STRING_LEN+1)
112 
113 static int usb_string_copy(const char *s, char **s_copy)
114 {
115 	int ret;
116 	char *str;
117 	char *copy = *s_copy;
118 	ret = strlen(s);
119 	if (ret > USB_MAX_STRING_LEN)
120 		return -EOVERFLOW;
121 
122 	if (copy) {
123 		str = copy;
124 	} else {
125 		str = kmalloc(USB_MAX_STRING_WITH_NULL_LEN, GFP_KERNEL);
126 		if (!str)
127 			return -ENOMEM;
128 	}
129 	strcpy(str, s);
130 	if (str[ret - 1] == '\n')
131 		str[ret - 1] = '\0';
132 	*s_copy = str;
133 	return 0;
134 }
135 
136 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
137 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
138 			char *page)	\
139 {	\
140 	return sprintf(page, "0x%02x\n", \
141 		to_gadget_info(item)->cdev.desc.__name); \
142 }
143 
144 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
145 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
146 			char *page)	\
147 {	\
148 	return sprintf(page, "0x%04x\n", \
149 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
150 }
151 
152 
153 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
154 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
155 		const char *page, size_t len)		\
156 {							\
157 	u8 val;						\
158 	int ret;					\
159 	ret = kstrtou8(page, 0, &val);			\
160 	if (ret)					\
161 		return ret;				\
162 	to_gadget_info(item)->cdev.desc._name = val;	\
163 	return len;					\
164 }
165 
166 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
167 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
168 		const char *page, size_t len)		\
169 {							\
170 	u16 val;					\
171 	int ret;					\
172 	ret = kstrtou16(page, 0, &val);			\
173 	if (ret)					\
174 		return ret;				\
175 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
176 	return len;					\
177 }
178 
179 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
180 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
181 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
182 
183 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
184 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
185 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
186 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
187 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
188 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
189 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
190 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
191 
192 static ssize_t is_valid_bcd(u16 bcd_val)
193 {
194 	if ((bcd_val & 0xf) > 9)
195 		return -EINVAL;
196 	if (((bcd_val >> 4) & 0xf) > 9)
197 		return -EINVAL;
198 	if (((bcd_val >> 8) & 0xf) > 9)
199 		return -EINVAL;
200 	if (((bcd_val >> 12) & 0xf) > 9)
201 		return -EINVAL;
202 	return 0;
203 }
204 
205 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
206 		const char *page, size_t len)
207 {
208 	u16 bcdDevice;
209 	int ret;
210 
211 	ret = kstrtou16(page, 0, &bcdDevice);
212 	if (ret)
213 		return ret;
214 	ret = is_valid_bcd(bcdDevice);
215 	if (ret)
216 		return ret;
217 
218 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
219 	return len;
220 }
221 
222 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
223 		const char *page, size_t len)
224 {
225 	u16 bcdUSB;
226 	int ret;
227 
228 	ret = kstrtou16(page, 0, &bcdUSB);
229 	if (ret)
230 		return ret;
231 	ret = is_valid_bcd(bcdUSB);
232 	if (ret)
233 		return ret;
234 
235 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
236 	return len;
237 }
238 
239 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
240 {
241 	struct gadget_info *gi = to_gadget_info(item);
242 	char *udc_name;
243 	int ret;
244 
245 	mutex_lock(&gi->lock);
246 	udc_name = gi->composite.gadget_driver.udc_name;
247 	ret = sprintf(page, "%s\n", udc_name ?: "");
248 	mutex_unlock(&gi->lock);
249 
250 	return ret;
251 }
252 
253 static int unregister_gadget(struct gadget_info *gi)
254 {
255 	int ret;
256 
257 	if (!gi->composite.gadget_driver.udc_name)
258 		return -ENODEV;
259 
260 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
261 	if (ret)
262 		return ret;
263 	kfree(gi->composite.gadget_driver.udc_name);
264 	gi->composite.gadget_driver.udc_name = NULL;
265 	return 0;
266 }
267 
268 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
269 		const char *page, size_t len)
270 {
271 	struct gadget_info *gi = to_gadget_info(item);
272 	char *name;
273 	int ret;
274 
275 	if (strlen(page) < len)
276 		return -EOVERFLOW;
277 
278 	name = kstrdup(page, GFP_KERNEL);
279 	if (!name)
280 		return -ENOMEM;
281 	if (name[len - 1] == '\n')
282 		name[len - 1] = '\0';
283 
284 	mutex_lock(&gi->lock);
285 
286 	if (!strlen(name)) {
287 		ret = unregister_gadget(gi);
288 		if (ret)
289 			goto err;
290 		kfree(name);
291 	} else {
292 		if (gi->composite.gadget_driver.udc_name) {
293 			ret = -EBUSY;
294 			goto err;
295 		}
296 		gi->composite.gadget_driver.udc_name = name;
297 		ret = usb_gadget_register_driver(&gi->composite.gadget_driver);
298 		if (ret) {
299 			gi->composite.gadget_driver.udc_name = NULL;
300 			goto err;
301 		}
302 	}
303 	mutex_unlock(&gi->lock);
304 	return len;
305 err:
306 	kfree(name);
307 	mutex_unlock(&gi->lock);
308 	return ret;
309 }
310 
311 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
312 					      char *page)
313 {
314 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
315 
316 	return sprintf(page, "%s\n", usb_speed_string(speed));
317 }
318 
319 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
320 					       const char *page, size_t len)
321 {
322 	struct gadget_info *gi = to_gadget_info(item);
323 
324 	mutex_lock(&gi->lock);
325 
326 	/* Prevent changing of max_speed after the driver is binded */
327 	if (gi->composite.gadget_driver.udc_name)
328 		goto err;
329 
330 	if (strncmp(page, "super-speed-plus", 16) == 0)
331 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
332 	else if (strncmp(page, "super-speed", 11) == 0)
333 		gi->composite.max_speed = USB_SPEED_SUPER;
334 	else if (strncmp(page, "high-speed", 10) == 0)
335 		gi->composite.max_speed = USB_SPEED_HIGH;
336 	else if (strncmp(page, "full-speed", 10) == 0)
337 		gi->composite.max_speed = USB_SPEED_FULL;
338 	else if (strncmp(page, "low-speed", 9) == 0)
339 		gi->composite.max_speed = USB_SPEED_LOW;
340 	else
341 		goto err;
342 
343 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
344 
345 	mutex_unlock(&gi->lock);
346 	return len;
347 err:
348 	mutex_unlock(&gi->lock);
349 	return -EINVAL;
350 }
351 
352 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
353 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
354 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
355 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
356 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
357 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
358 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
359 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
360 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
361 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
362 
363 static struct configfs_attribute *gadget_root_attrs[] = {
364 	&gadget_dev_desc_attr_bDeviceClass,
365 	&gadget_dev_desc_attr_bDeviceSubClass,
366 	&gadget_dev_desc_attr_bDeviceProtocol,
367 	&gadget_dev_desc_attr_bMaxPacketSize0,
368 	&gadget_dev_desc_attr_idVendor,
369 	&gadget_dev_desc_attr_idProduct,
370 	&gadget_dev_desc_attr_bcdDevice,
371 	&gadget_dev_desc_attr_bcdUSB,
372 	&gadget_dev_desc_attr_UDC,
373 	&gadget_dev_desc_attr_max_speed,
374 	NULL,
375 };
376 
377 static inline struct gadget_language *to_gadget_language(struct config_item *item)
378 {
379 	return container_of(to_config_group(item), struct gadget_language,
380 			 group);
381 }
382 
383 static inline struct gadget_config_name *to_gadget_config_name(
384 		struct config_item *item)
385 {
386 	return container_of(to_config_group(item), struct gadget_config_name,
387 			 group);
388 }
389 
390 static inline struct usb_function_instance *to_usb_function_instance(
391 		struct config_item *item)
392 {
393 	return container_of(to_config_group(item),
394 			 struct usb_function_instance, group);
395 }
396 
397 static void gadget_info_attr_release(struct config_item *item)
398 {
399 	struct gadget_info *gi = to_gadget_info(item);
400 
401 	WARN_ON(!list_empty(&gi->cdev.configs));
402 	WARN_ON(!list_empty(&gi->string_list));
403 	WARN_ON(!list_empty(&gi->available_func));
404 	kfree(gi->composite.gadget_driver.function);
405 	kfree(gi->composite.gadget_driver.driver.name);
406 	kfree(gi);
407 }
408 
409 static struct configfs_item_operations gadget_root_item_ops = {
410 	.release                = gadget_info_attr_release,
411 };
412 
413 static void gadget_config_attr_release(struct config_item *item)
414 {
415 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
416 
417 	WARN_ON(!list_empty(&cfg->c.functions));
418 	list_del(&cfg->c.list);
419 	kfree(cfg->c.label);
420 	kfree(cfg);
421 }
422 
423 static int config_usb_cfg_link(
424 	struct config_item *usb_cfg_ci,
425 	struct config_item *usb_func_ci)
426 {
427 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
428 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
429 
430 	struct usb_function_instance *fi =
431 			to_usb_function_instance(usb_func_ci);
432 	struct usb_function_instance *a_fi = NULL, *iter;
433 	struct usb_function *f;
434 	int ret;
435 
436 	mutex_lock(&gi->lock);
437 	/*
438 	 * Make sure this function is from within our _this_ gadget and not
439 	 * from another gadget or a random directory.
440 	 * Also a function instance can only be linked once.
441 	 */
442 
443 	if (gi->composite.gadget_driver.udc_name) {
444 		ret = -EINVAL;
445 		goto out;
446 	}
447 
448 	list_for_each_entry(iter, &gi->available_func, cfs_list) {
449 		if (iter != fi)
450 			continue;
451 		a_fi = iter;
452 		break;
453 	}
454 	if (!a_fi) {
455 		ret = -EINVAL;
456 		goto out;
457 	}
458 
459 	list_for_each_entry(f, &cfg->func_list, list) {
460 		if (f->fi == fi) {
461 			ret = -EEXIST;
462 			goto out;
463 		}
464 	}
465 
466 	f = usb_get_function(fi);
467 	if (IS_ERR(f)) {
468 		ret = PTR_ERR(f);
469 		goto out;
470 	}
471 
472 	/* stash the function until we bind it to the gadget */
473 	list_add_tail(&f->list, &cfg->func_list);
474 	ret = 0;
475 out:
476 	mutex_unlock(&gi->lock);
477 	return ret;
478 }
479 
480 static void config_usb_cfg_unlink(
481 	struct config_item *usb_cfg_ci,
482 	struct config_item *usb_func_ci)
483 {
484 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
485 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
486 
487 	struct usb_function_instance *fi =
488 			to_usb_function_instance(usb_func_ci);
489 	struct usb_function *f;
490 
491 	/*
492 	 * ideally I would like to forbid to unlink functions while a gadget is
493 	 * bound to an UDC. Since this isn't possible at the moment, we simply
494 	 * force an unbind, the function is available here and then we can
495 	 * remove the function.
496 	 */
497 	mutex_lock(&gi->lock);
498 	if (gi->composite.gadget_driver.udc_name)
499 		unregister_gadget(gi);
500 	WARN_ON(gi->composite.gadget_driver.udc_name);
501 
502 	list_for_each_entry(f, &cfg->func_list, list) {
503 		if (f->fi == fi) {
504 			list_del(&f->list);
505 			usb_put_function(f);
506 			mutex_unlock(&gi->lock);
507 			return;
508 		}
509 	}
510 	mutex_unlock(&gi->lock);
511 	WARN(1, "Unable to locate function to unbind\n");
512 }
513 
514 static struct configfs_item_operations gadget_config_item_ops = {
515 	.release                = gadget_config_attr_release,
516 	.allow_link             = config_usb_cfg_link,
517 	.drop_link              = config_usb_cfg_unlink,
518 };
519 
520 
521 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
522 		char *page)
523 {
524 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
525 
526 	return sprintf(page, "%u\n", cfg->c.MaxPower);
527 }
528 
529 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
530 		const char *page, size_t len)
531 {
532 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
533 	u16 val;
534 	int ret;
535 	ret = kstrtou16(page, 0, &val);
536 	if (ret)
537 		return ret;
538 	if (DIV_ROUND_UP(val, 8) > 0xff)
539 		return -ERANGE;
540 	cfg->c.MaxPower = val;
541 	return len;
542 }
543 
544 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
545 		char *page)
546 {
547 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
548 
549 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
550 }
551 
552 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
553 		const char *page, size_t len)
554 {
555 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
556 	u8 val;
557 	int ret;
558 	ret = kstrtou8(page, 0, &val);
559 	if (ret)
560 		return ret;
561 	if (!(val & USB_CONFIG_ATT_ONE))
562 		return -EINVAL;
563 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
564 				USB_CONFIG_ATT_WAKEUP))
565 		return -EINVAL;
566 	cfg->c.bmAttributes = val;
567 	return len;
568 }
569 
570 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
571 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
572 
573 static struct configfs_attribute *gadget_config_attrs[] = {
574 	&gadget_config_desc_attr_MaxPower,
575 	&gadget_config_desc_attr_bmAttributes,
576 	NULL,
577 };
578 
579 static const struct config_item_type gadget_config_type = {
580 	.ct_item_ops	= &gadget_config_item_ops,
581 	.ct_attrs	= gadget_config_attrs,
582 	.ct_owner	= THIS_MODULE,
583 };
584 
585 static const struct config_item_type gadget_root_type = {
586 	.ct_item_ops	= &gadget_root_item_ops,
587 	.ct_attrs	= gadget_root_attrs,
588 	.ct_owner	= THIS_MODULE,
589 };
590 
591 static void composite_init_dev(struct usb_composite_dev *cdev)
592 {
593 	spin_lock_init(&cdev->lock);
594 	INIT_LIST_HEAD(&cdev->configs);
595 	INIT_LIST_HEAD(&cdev->gstrings);
596 }
597 
598 static struct config_group *function_make(
599 		struct config_group *group,
600 		const char *name)
601 {
602 	struct gadget_info *gi;
603 	struct usb_function_instance *fi;
604 	char buf[MAX_NAME_LEN];
605 	char *func_name;
606 	char *instance_name;
607 	int ret;
608 
609 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
610 	if (ret >= MAX_NAME_LEN)
611 		return ERR_PTR(-ENAMETOOLONG);
612 
613 	func_name = buf;
614 	instance_name = strchr(func_name, '.');
615 	if (!instance_name) {
616 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
617 		return ERR_PTR(-EINVAL);
618 	}
619 	*instance_name = '\0';
620 	instance_name++;
621 
622 	fi = usb_get_function_instance(func_name);
623 	if (IS_ERR(fi))
624 		return ERR_CAST(fi);
625 
626 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
627 	if (ret) {
628 		usb_put_function_instance(fi);
629 		return ERR_PTR(ret);
630 	}
631 	if (fi->set_inst_name) {
632 		ret = fi->set_inst_name(fi, instance_name);
633 		if (ret) {
634 			usb_put_function_instance(fi);
635 			return ERR_PTR(ret);
636 		}
637 	}
638 
639 	gi = container_of(group, struct gadget_info, functions_group);
640 
641 	mutex_lock(&gi->lock);
642 	list_add_tail(&fi->cfs_list, &gi->available_func);
643 	mutex_unlock(&gi->lock);
644 	return &fi->group;
645 }
646 
647 static void function_drop(
648 		struct config_group *group,
649 		struct config_item *item)
650 {
651 	struct usb_function_instance *fi = to_usb_function_instance(item);
652 	struct gadget_info *gi;
653 
654 	gi = container_of(group, struct gadget_info, functions_group);
655 
656 	mutex_lock(&gi->lock);
657 	list_del(&fi->cfs_list);
658 	mutex_unlock(&gi->lock);
659 	config_item_put(item);
660 }
661 
662 static struct configfs_group_operations functions_ops = {
663 	.make_group     = &function_make,
664 	.drop_item      = &function_drop,
665 };
666 
667 static const struct config_item_type functions_type = {
668 	.ct_group_ops   = &functions_ops,
669 	.ct_owner       = THIS_MODULE,
670 };
671 
672 GS_STRINGS_RW(gadget_config_name, configuration);
673 
674 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
675 	&gadget_config_name_attr_configuration,
676 	NULL,
677 };
678 
679 static void gadget_config_name_attr_release(struct config_item *item)
680 {
681 	struct gadget_config_name *cn = to_gadget_config_name(item);
682 
683 	kfree(cn->configuration);
684 
685 	list_del(&cn->list);
686 	kfree(cn);
687 }
688 
689 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
690 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
691 
692 static struct config_group *config_desc_make(
693 		struct config_group *group,
694 		const char *name)
695 {
696 	struct gadget_info *gi;
697 	struct config_usb_cfg *cfg;
698 	char buf[MAX_NAME_LEN];
699 	char *num_str;
700 	u8 num;
701 	int ret;
702 
703 	gi = container_of(group, struct gadget_info, configs_group);
704 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
705 	if (ret >= MAX_NAME_LEN)
706 		return ERR_PTR(-ENAMETOOLONG);
707 
708 	num_str = strchr(buf, '.');
709 	if (!num_str) {
710 		pr_err("Unable to locate . in name.bConfigurationValue\n");
711 		return ERR_PTR(-EINVAL);
712 	}
713 
714 	*num_str = '\0';
715 	num_str++;
716 
717 	if (!strlen(buf))
718 		return ERR_PTR(-EINVAL);
719 
720 	ret = kstrtou8(num_str, 0, &num);
721 	if (ret)
722 		return ERR_PTR(ret);
723 
724 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
725 	if (!cfg)
726 		return ERR_PTR(-ENOMEM);
727 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
728 	if (!cfg->c.label) {
729 		ret = -ENOMEM;
730 		goto err;
731 	}
732 	cfg->c.bConfigurationValue = num;
733 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
734 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
735 	INIT_LIST_HEAD(&cfg->string_list);
736 	INIT_LIST_HEAD(&cfg->func_list);
737 
738 	config_group_init_type_name(&cfg->group, name,
739 				&gadget_config_type);
740 
741 	config_group_init_type_name(&cfg->strings_group, "strings",
742 			&gadget_config_name_strings_type);
743 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
744 
745 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
746 	if (ret)
747 		goto err;
748 
749 	return &cfg->group;
750 err:
751 	kfree(cfg->c.label);
752 	kfree(cfg);
753 	return ERR_PTR(ret);
754 }
755 
756 static void config_desc_drop(
757 		struct config_group *group,
758 		struct config_item *item)
759 {
760 	config_item_put(item);
761 }
762 
763 static struct configfs_group_operations config_desc_ops = {
764 	.make_group     = &config_desc_make,
765 	.drop_item      = &config_desc_drop,
766 };
767 
768 static const struct config_item_type config_desc_type = {
769 	.ct_group_ops   = &config_desc_ops,
770 	.ct_owner       = THIS_MODULE,
771 };
772 
773 GS_STRINGS_RW(gadget_language, manufacturer);
774 GS_STRINGS_RW(gadget_language, product);
775 GS_STRINGS_RW(gadget_language, serialnumber);
776 
777 static struct configfs_attribute *gadget_language_langid_attrs[] = {
778 	&gadget_language_attr_manufacturer,
779 	&gadget_language_attr_product,
780 	&gadget_language_attr_serialnumber,
781 	NULL,
782 };
783 
784 static void gadget_language_attr_release(struct config_item *item)
785 {
786 	struct gadget_language *gs = to_gadget_language(item);
787 
788 	kfree(gs->manufacturer);
789 	kfree(gs->product);
790 	kfree(gs->serialnumber);
791 
792 	list_del(&gs->list);
793 	kfree(gs);
794 }
795 
796 static struct configfs_item_operations gadget_language_langid_item_ops = {
797 	.release                = gadget_language_attr_release,
798 };
799 
800 static ssize_t gadget_string_id_show(struct config_item *item, char *page)
801 {
802 	struct gadget_string *string = to_gadget_string(item);
803 	int ret;
804 
805 	ret = sprintf(page, "%u\n", string->usb_string.id);
806 	return ret;
807 }
808 CONFIGFS_ATTR_RO(gadget_string_, id);
809 
810 static ssize_t gadget_string_s_show(struct config_item *item, char *page)
811 {
812 	struct gadget_string *string = to_gadget_string(item);
813 	int ret;
814 
815 	ret = snprintf(page, sizeof(string->string), "%s\n", string->string);
816 	return ret;
817 }
818 
819 static ssize_t gadget_string_s_store(struct config_item *item, const char *page,
820 				     size_t len)
821 {
822 	struct gadget_string *string = to_gadget_string(item);
823 	int size = min(sizeof(string->string), len + 1);
824 
825 	if (len > USB_MAX_STRING_LEN)
826 		return -EINVAL;
827 
828 	return strscpy(string->string, page, size);
829 }
830 CONFIGFS_ATTR(gadget_string_, s);
831 
832 static struct configfs_attribute *gadget_string_attrs[] = {
833 	&gadget_string_attr_id,
834 	&gadget_string_attr_s,
835 	NULL,
836 };
837 
838 static void gadget_string_release(struct config_item *item)
839 {
840 	struct gadget_string *string = to_gadget_string(item);
841 
842 	kfree(string);
843 }
844 
845 static struct configfs_item_operations gadget_string_item_ops = {
846 	.release	= gadget_string_release,
847 };
848 
849 static const struct config_item_type gadget_string_type = {
850 	.ct_item_ops	= &gadget_string_item_ops,
851 	.ct_attrs	= gadget_string_attrs,
852 	.ct_owner	= THIS_MODULE,
853 };
854 
855 static struct config_item *gadget_language_string_make(struct config_group *group,
856 						       const char *name)
857 {
858 	struct gadget_language *language;
859 	struct gadget_string *string;
860 
861 	language = to_gadget_language(&group->cg_item);
862 
863 	string = kzalloc(sizeof(*string), GFP_KERNEL);
864 	if (!string)
865 		return ERR_PTR(-ENOMEM);
866 
867 	string->usb_string.id = language->nstrings++;
868 	string->usb_string.s = string->string;
869 	list_add_tail(&string->list, &language->gadget_strings);
870 
871 	config_item_init_type_name(&string->item, name, &gadget_string_type);
872 
873 	return &string->item;
874 }
875 
876 static void gadget_language_string_drop(struct config_group *group,
877 					struct config_item *item)
878 {
879 	struct gadget_language *language;
880 	struct gadget_string *string;
881 	unsigned int i = USB_GADGET_FIRST_AVAIL_IDX;
882 
883 	language = to_gadget_language(&group->cg_item);
884 	string = to_gadget_string(item);
885 
886 	list_del(&string->list);
887 	language->nstrings--;
888 
889 	/* Reset the ids for the language's strings to guarantee a continuous set */
890 	list_for_each_entry(string, &language->gadget_strings, list)
891 		string->usb_string.id = i++;
892 }
893 
894 static struct configfs_group_operations gadget_language_langid_group_ops = {
895 	.make_item		= gadget_language_string_make,
896 	.drop_item		= gadget_language_string_drop,
897 };
898 
899 static struct config_item_type gadget_language_type = {
900 	.ct_item_ops	= &gadget_language_langid_item_ops,
901 	.ct_group_ops	= &gadget_language_langid_group_ops,
902 	.ct_attrs	= gadget_language_langid_attrs,
903 	.ct_owner	= THIS_MODULE,
904 };
905 
906 static struct config_group *gadget_language_make(struct config_group *group,
907 						 const char *name)
908 {
909 	struct gadget_info *gi;
910 	struct gadget_language *gs;
911 	struct gadget_language *new;
912 	int langs = 0;
913 	int ret;
914 
915 	new = kzalloc(sizeof(*new), GFP_KERNEL);
916 	if (!new)
917 		return ERR_PTR(-ENOMEM);
918 
919 	ret = check_user_usb_string(name, &new->stringtab_dev);
920 	if (ret)
921 		goto err;
922 	config_group_init_type_name(&new->group, name,
923 				    &gadget_language_type);
924 
925 	gi = container_of(group, struct gadget_info, strings_group);
926 	ret = -EEXIST;
927 	list_for_each_entry(gs, &gi->string_list, list) {
928 		if (gs->stringtab_dev.language == new->stringtab_dev.language)
929 			goto err;
930 		langs++;
931 	}
932 	ret = -EOVERFLOW;
933 	if (langs >= MAX_USB_STRING_LANGS)
934 		goto err;
935 
936 	list_add_tail(&new->list, &gi->string_list);
937 	INIT_LIST_HEAD(&new->gadget_strings);
938 
939 	/* We have the default manufacturer, product and serialnumber strings */
940 	new->nstrings = 3;
941 	return &new->group;
942 err:
943 	kfree(new);
944 	return ERR_PTR(ret);
945 }
946 
947 static void gadget_language_drop(struct config_group *group,
948 				 struct config_item *item)
949 {
950 	config_item_put(item);
951 }
952 
953 static struct configfs_group_operations gadget_language_group_ops = {
954 	.make_group     = &gadget_language_make,
955 	.drop_item      = &gadget_language_drop,
956 };
957 
958 static struct config_item_type gadget_language_strings_type = {
959 	.ct_group_ops   = &gadget_language_group_ops,
960 	.ct_owner       = THIS_MODULE,
961 };
962 
963 static inline struct gadget_info *webusb_item_to_gadget_info(
964 		struct config_item *item)
965 {
966 	return container_of(to_config_group(item),
967 			struct gadget_info, webusb_group);
968 }
969 
970 static ssize_t webusb_use_show(struct config_item *item, char *page)
971 {
972 	return sysfs_emit(page, "%d\n",
973 			webusb_item_to_gadget_info(item)->use_webusb);
974 }
975 
976 static ssize_t webusb_use_store(struct config_item *item, const char *page,
977 				 size_t len)
978 {
979 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
980 	int ret;
981 	bool use;
982 
983 	ret = kstrtobool(page, &use);
984 	if (ret)
985 		return ret;
986 
987 	mutex_lock(&gi->lock);
988 	gi->use_webusb = use;
989 	mutex_unlock(&gi->lock);
990 
991 	return len;
992 }
993 
994 static ssize_t webusb_bcdVersion_show(struct config_item *item, char *page)
995 {
996 	return sysfs_emit(page, "0x%04x\n",
997 					webusb_item_to_gadget_info(item)->bcd_webusb_version);
998 }
999 
1000 static ssize_t webusb_bcdVersion_store(struct config_item *item,
1001 		const char *page, size_t len)
1002 {
1003 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1004 	u16 bcdVersion;
1005 	int ret;
1006 
1007 	ret = kstrtou16(page, 0, &bcdVersion);
1008 	if (ret)
1009 		return ret;
1010 
1011 	ret = is_valid_bcd(bcdVersion);
1012 	if (ret)
1013 		return ret;
1014 
1015 	mutex_lock(&gi->lock);
1016 	gi->bcd_webusb_version = bcdVersion;
1017 	mutex_unlock(&gi->lock);
1018 
1019 	return len;
1020 }
1021 
1022 static ssize_t webusb_bVendorCode_show(struct config_item *item, char *page)
1023 {
1024 	return sysfs_emit(page, "0x%02x\n",
1025 			webusb_item_to_gadget_info(item)->b_webusb_vendor_code);
1026 }
1027 
1028 static ssize_t webusb_bVendorCode_store(struct config_item *item,
1029 					   const char *page, size_t len)
1030 {
1031 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1032 	int ret;
1033 	u8 b_vendor_code;
1034 
1035 	ret = kstrtou8(page, 0, &b_vendor_code);
1036 	if (ret)
1037 		return ret;
1038 
1039 	mutex_lock(&gi->lock);
1040 	gi->b_webusb_vendor_code = b_vendor_code;
1041 	mutex_unlock(&gi->lock);
1042 
1043 	return len;
1044 }
1045 
1046 static ssize_t webusb_landingPage_show(struct config_item *item, char *page)
1047 {
1048 	return sysfs_emit(page, "%s\n", webusb_item_to_gadget_info(item)->landing_page);
1049 }
1050 
1051 static ssize_t webusb_landingPage_store(struct config_item *item, const char *page,
1052 				     size_t len)
1053 {
1054 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1055 	unsigned int bytes_to_strip = 0;
1056 	int l = len;
1057 
1058 	if (page[l - 1] == '\n') {
1059 		--l;
1060 		++bytes_to_strip;
1061 	}
1062 
1063 	if (l > sizeof(gi->landing_page)) {
1064 		pr_err("webusb: landingPage URL too long\n");
1065 		return -EINVAL;
1066 	}
1067 
1068 	// validation
1069 	if (strncasecmp(page, "https://",  8) == 0)
1070 		bytes_to_strip = 8;
1071 	else if (strncasecmp(page, "http://", 7) == 0)
1072 		bytes_to_strip = 7;
1073 	else
1074 		bytes_to_strip = 0;
1075 
1076 	if (l > U8_MAX - WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + bytes_to_strip) {
1077 		pr_err("webusb: landingPage URL %d bytes too long for given URL scheme\n",
1078 			l - U8_MAX + WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH - bytes_to_strip);
1079 		return -EINVAL;
1080 	}
1081 
1082 	mutex_lock(&gi->lock);
1083 	// ensure 0 bytes are set, in case the new landing page is shorter then the old one.
1084 	memcpy_and_pad(gi->landing_page, sizeof(gi->landing_page), page, l, 0);
1085 	mutex_unlock(&gi->lock);
1086 
1087 	return len;
1088 }
1089 
1090 CONFIGFS_ATTR(webusb_, use);
1091 CONFIGFS_ATTR(webusb_, bVendorCode);
1092 CONFIGFS_ATTR(webusb_, bcdVersion);
1093 CONFIGFS_ATTR(webusb_, landingPage);
1094 
1095 static struct configfs_attribute *webusb_attrs[] = {
1096 	&webusb_attr_use,
1097 	&webusb_attr_bcdVersion,
1098 	&webusb_attr_bVendorCode,
1099 	&webusb_attr_landingPage,
1100 	NULL,
1101 };
1102 
1103 static struct config_item_type webusb_type = {
1104 	.ct_attrs	= webusb_attrs,
1105 	.ct_owner	= THIS_MODULE,
1106 };
1107 
1108 static inline struct gadget_info *os_desc_item_to_gadget_info(
1109 		struct config_item *item)
1110 {
1111 	return container_of(to_config_group(item),
1112 			struct gadget_info, os_desc_group);
1113 }
1114 
1115 static ssize_t os_desc_use_show(struct config_item *item, char *page)
1116 {
1117 	return sprintf(page, "%d\n",
1118 			os_desc_item_to_gadget_info(item)->use_os_desc);
1119 }
1120 
1121 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
1122 				 size_t len)
1123 {
1124 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1125 	int ret;
1126 	bool use;
1127 
1128 	ret = kstrtobool(page, &use);
1129 	if (ret)
1130 		return ret;
1131 
1132 	mutex_lock(&gi->lock);
1133 	gi->use_os_desc = use;
1134 	mutex_unlock(&gi->lock);
1135 
1136 	return len;
1137 }
1138 
1139 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
1140 {
1141 	return sprintf(page, "0x%02x\n",
1142 			os_desc_item_to_gadget_info(item)->b_vendor_code);
1143 }
1144 
1145 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
1146 					   const char *page, size_t len)
1147 {
1148 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1149 	int ret;
1150 	u8 b_vendor_code;
1151 
1152 	ret = kstrtou8(page, 0, &b_vendor_code);
1153 	if (ret)
1154 		return ret;
1155 
1156 	mutex_lock(&gi->lock);
1157 	gi->b_vendor_code = b_vendor_code;
1158 	mutex_unlock(&gi->lock);
1159 
1160 	return len;
1161 }
1162 
1163 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
1164 {
1165 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1166 	int res;
1167 
1168 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
1169 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
1170 	page[res++] = '\n';
1171 
1172 	return res;
1173 }
1174 
1175 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
1176 				     size_t len)
1177 {
1178 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1179 	int res, l;
1180 
1181 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
1182 	if (page[l - 1] == '\n')
1183 		--l;
1184 
1185 	mutex_lock(&gi->lock);
1186 	res = utf8s_to_utf16s(page, l,
1187 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
1188 			      OS_STRING_QW_SIGN_LEN);
1189 	if (res > 0)
1190 		res = len;
1191 	mutex_unlock(&gi->lock);
1192 
1193 	return res;
1194 }
1195 
1196 CONFIGFS_ATTR(os_desc_, use);
1197 CONFIGFS_ATTR(os_desc_, b_vendor_code);
1198 CONFIGFS_ATTR(os_desc_, qw_sign);
1199 
1200 static struct configfs_attribute *os_desc_attrs[] = {
1201 	&os_desc_attr_use,
1202 	&os_desc_attr_b_vendor_code,
1203 	&os_desc_attr_qw_sign,
1204 	NULL,
1205 };
1206 
1207 static int os_desc_link(struct config_item *os_desc_ci,
1208 			struct config_item *usb_cfg_ci)
1209 {
1210 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
1211 	struct usb_composite_dev *cdev = &gi->cdev;
1212 	struct config_usb_cfg *c_target = to_config_usb_cfg(usb_cfg_ci);
1213 	struct usb_configuration *c = NULL, *iter;
1214 	int ret;
1215 
1216 	mutex_lock(&gi->lock);
1217 	list_for_each_entry(iter, &cdev->configs, list) {
1218 		if (iter != &c_target->c)
1219 			continue;
1220 		c = iter;
1221 		break;
1222 	}
1223 	if (!c) {
1224 		ret = -EINVAL;
1225 		goto out;
1226 	}
1227 
1228 	if (cdev->os_desc_config) {
1229 		ret = -EBUSY;
1230 		goto out;
1231 	}
1232 
1233 	cdev->os_desc_config = &c_target->c;
1234 	ret = 0;
1235 
1236 out:
1237 	mutex_unlock(&gi->lock);
1238 	return ret;
1239 }
1240 
1241 static void os_desc_unlink(struct config_item *os_desc_ci,
1242 			  struct config_item *usb_cfg_ci)
1243 {
1244 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
1245 	struct usb_composite_dev *cdev = &gi->cdev;
1246 
1247 	mutex_lock(&gi->lock);
1248 	if (gi->composite.gadget_driver.udc_name)
1249 		unregister_gadget(gi);
1250 	cdev->os_desc_config = NULL;
1251 	WARN_ON(gi->composite.gadget_driver.udc_name);
1252 	mutex_unlock(&gi->lock);
1253 }
1254 
1255 static struct configfs_item_operations os_desc_ops = {
1256 	.allow_link		= os_desc_link,
1257 	.drop_link		= os_desc_unlink,
1258 };
1259 
1260 static struct config_item_type os_desc_type = {
1261 	.ct_item_ops	= &os_desc_ops,
1262 	.ct_attrs	= os_desc_attrs,
1263 	.ct_owner	= THIS_MODULE,
1264 };
1265 
1266 static inline struct usb_os_desc_ext_prop
1267 *to_usb_os_desc_ext_prop(struct config_item *item)
1268 {
1269 	return container_of(item, struct usb_os_desc_ext_prop, item);
1270 }
1271 
1272 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
1273 {
1274 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
1275 }
1276 
1277 static ssize_t ext_prop_type_store(struct config_item *item,
1278 				   const char *page, size_t len)
1279 {
1280 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1281 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1282 	u8 type;
1283 	int ret;
1284 
1285 	ret = kstrtou8(page, 0, &type);
1286 	if (ret)
1287 		return ret;
1288 
1289 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI)
1290 		return -EINVAL;
1291 
1292 	if (desc->opts_mutex)
1293 		mutex_lock(desc->opts_mutex);
1294 
1295 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
1296 	    ext_prop->type == USB_EXT_PROP_LE32 ||
1297 	    ext_prop->type == USB_EXT_PROP_BE32) &&
1298 	    (type == USB_EXT_PROP_UNICODE ||
1299 	    type == USB_EXT_PROP_UNICODE_ENV ||
1300 	    type == USB_EXT_PROP_UNICODE_LINK))
1301 		ext_prop->data_len <<= 1;
1302 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
1303 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1304 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
1305 		   (type == USB_EXT_PROP_BINARY ||
1306 		   type == USB_EXT_PROP_LE32 ||
1307 		   type == USB_EXT_PROP_BE32))
1308 		ext_prop->data_len >>= 1;
1309 	ext_prop->type = type;
1310 
1311 	if (desc->opts_mutex)
1312 		mutex_unlock(desc->opts_mutex);
1313 	return len;
1314 }
1315 
1316 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
1317 {
1318 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1319 	int len = ext_prop->data_len;
1320 
1321 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1322 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1323 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1324 		len >>= 1;
1325 	memcpy(page, ext_prop->data, len);
1326 
1327 	return len;
1328 }
1329 
1330 static ssize_t ext_prop_data_store(struct config_item *item,
1331 				   const char *page, size_t len)
1332 {
1333 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1334 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1335 	char *new_data;
1336 	size_t ret_len = len;
1337 
1338 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1339 		--len;
1340 	new_data = kmemdup(page, len, GFP_KERNEL);
1341 	if (!new_data)
1342 		return -ENOMEM;
1343 
1344 	if (desc->opts_mutex)
1345 		mutex_lock(desc->opts_mutex);
1346 	kfree(ext_prop->data);
1347 	ext_prop->data = new_data;
1348 	desc->ext_prop_len -= ext_prop->data_len;
1349 	ext_prop->data_len = len;
1350 	desc->ext_prop_len += ext_prop->data_len;
1351 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1352 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1353 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1354 		desc->ext_prop_len -= ext_prop->data_len;
1355 		ext_prop->data_len <<= 1;
1356 		ext_prop->data_len += 2;
1357 		desc->ext_prop_len += ext_prop->data_len;
1358 	}
1359 	if (desc->opts_mutex)
1360 		mutex_unlock(desc->opts_mutex);
1361 	return ret_len;
1362 }
1363 
1364 CONFIGFS_ATTR(ext_prop_, type);
1365 CONFIGFS_ATTR(ext_prop_, data);
1366 
1367 static struct configfs_attribute *ext_prop_attrs[] = {
1368 	&ext_prop_attr_type,
1369 	&ext_prop_attr_data,
1370 	NULL,
1371 };
1372 
1373 static void usb_os_desc_ext_prop_release(struct config_item *item)
1374 {
1375 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1376 
1377 	kfree(ext_prop); /* frees a whole chunk */
1378 }
1379 
1380 static struct configfs_item_operations ext_prop_ops = {
1381 	.release		= usb_os_desc_ext_prop_release,
1382 };
1383 
1384 static struct config_item *ext_prop_make(
1385 		struct config_group *group,
1386 		const char *name)
1387 {
1388 	struct usb_os_desc_ext_prop *ext_prop;
1389 	struct config_item_type *ext_prop_type;
1390 	struct usb_os_desc *desc;
1391 	char *vlabuf;
1392 
1393 	vla_group(data_chunk);
1394 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1395 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1396 
1397 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1398 	if (!vlabuf)
1399 		return ERR_PTR(-ENOMEM);
1400 
1401 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1402 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1403 
1404 	desc = container_of(group, struct usb_os_desc, group);
1405 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1406 	ext_prop_type->ct_attrs = ext_prop_attrs;
1407 	ext_prop_type->ct_owner = desc->owner;
1408 
1409 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1410 
1411 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1412 	if (!ext_prop->name) {
1413 		kfree(vlabuf);
1414 		return ERR_PTR(-ENOMEM);
1415 	}
1416 	desc->ext_prop_len += 14;
1417 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1418 	if (desc->opts_mutex)
1419 		mutex_lock(desc->opts_mutex);
1420 	desc->ext_prop_len += ext_prop->name_len;
1421 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1422 	++desc->ext_prop_count;
1423 	if (desc->opts_mutex)
1424 		mutex_unlock(desc->opts_mutex);
1425 
1426 	return &ext_prop->item;
1427 }
1428 
1429 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1430 {
1431 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1432 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1433 
1434 	if (desc->opts_mutex)
1435 		mutex_lock(desc->opts_mutex);
1436 	list_del(&ext_prop->entry);
1437 	--desc->ext_prop_count;
1438 	kfree(ext_prop->name);
1439 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1440 	if (desc->opts_mutex)
1441 		mutex_unlock(desc->opts_mutex);
1442 	config_item_put(item);
1443 }
1444 
1445 static struct configfs_group_operations interf_grp_ops = {
1446 	.make_item	= &ext_prop_make,
1447 	.drop_item	= &ext_prop_drop,
1448 };
1449 
1450 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1451 					     char *page)
1452 {
1453 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1454 	return 8;
1455 }
1456 
1457 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1458 					      const char *page, size_t len)
1459 {
1460 	struct usb_os_desc *desc = to_usb_os_desc(item);
1461 	int l;
1462 
1463 	l = min_t(int, 8, len);
1464 	if (page[l - 1] == '\n')
1465 		--l;
1466 	if (desc->opts_mutex)
1467 		mutex_lock(desc->opts_mutex);
1468 	memcpy(desc->ext_compat_id, page, l);
1469 
1470 	if (desc->opts_mutex)
1471 		mutex_unlock(desc->opts_mutex);
1472 
1473 	return len;
1474 }
1475 
1476 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1477 						 char *page)
1478 {
1479 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1480 	return 8;
1481 }
1482 
1483 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1484 						  const char *page, size_t len)
1485 {
1486 	struct usb_os_desc *desc = to_usb_os_desc(item);
1487 	int l;
1488 
1489 	l = min_t(int, 8, len);
1490 	if (page[l - 1] == '\n')
1491 		--l;
1492 	if (desc->opts_mutex)
1493 		mutex_lock(desc->opts_mutex);
1494 	memcpy(desc->ext_compat_id + 8, page, l);
1495 
1496 	if (desc->opts_mutex)
1497 		mutex_unlock(desc->opts_mutex);
1498 
1499 	return len;
1500 }
1501 
1502 CONFIGFS_ATTR(interf_grp_, compatible_id);
1503 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1504 
1505 static struct configfs_attribute *interf_grp_attrs[] = {
1506 	&interf_grp_attr_compatible_id,
1507 	&interf_grp_attr_sub_compatible_id,
1508 	NULL
1509 };
1510 
1511 struct config_group *usb_os_desc_prepare_interf_dir(
1512 		struct config_group *parent,
1513 		int n_interf,
1514 		struct usb_os_desc **desc,
1515 		char **names,
1516 		struct module *owner)
1517 {
1518 	struct config_group *os_desc_group;
1519 	struct config_item_type *os_desc_type, *interface_type;
1520 
1521 	vla_group(data_chunk);
1522 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1523 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1524 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1525 
1526 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1527 	if (!vlabuf)
1528 		return ERR_PTR(-ENOMEM);
1529 
1530 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1531 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1532 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1533 
1534 	os_desc_type->ct_owner = owner;
1535 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1536 	configfs_add_default_group(os_desc_group, parent);
1537 
1538 	interface_type->ct_group_ops = &interf_grp_ops;
1539 	interface_type->ct_attrs = interf_grp_attrs;
1540 	interface_type->ct_owner = owner;
1541 
1542 	while (n_interf--) {
1543 		struct usb_os_desc *d;
1544 
1545 		d = desc[n_interf];
1546 		d->owner = owner;
1547 		config_group_init_type_name(&d->group, "", interface_type);
1548 		config_item_set_name(&d->group.cg_item, "interface.%s",
1549 				     names[n_interf]);
1550 		configfs_add_default_group(&d->group, os_desc_group);
1551 	}
1552 
1553 	return os_desc_group;
1554 }
1555 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1556 
1557 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1558 {
1559 	WARN_ON(1);
1560 	return -EINVAL;
1561 }
1562 
1563 int composite_dev_prepare(struct usb_composite_driver *composite,
1564 		struct usb_composite_dev *dev);
1565 
1566 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1567 				  struct usb_ep *ep0);
1568 
1569 static void purge_configs_funcs(struct gadget_info *gi)
1570 {
1571 	struct usb_configuration	*c;
1572 
1573 	list_for_each_entry(c, &gi->cdev.configs, list) {
1574 		struct usb_function *f, *tmp;
1575 		struct config_usb_cfg *cfg;
1576 
1577 		cfg = container_of(c, struct config_usb_cfg, c);
1578 
1579 		list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) {
1580 
1581 			list_move(&f->list, &cfg->func_list);
1582 			if (f->unbind) {
1583 				dev_dbg(&gi->cdev.gadget->dev,
1584 					"unbind function '%s'/%p\n",
1585 					f->name, f);
1586 				f->unbind(c, f);
1587 			}
1588 		}
1589 		c->next_interface_id = 0;
1590 		memset(c->interface, 0, sizeof(c->interface));
1591 		c->superspeed_plus = 0;
1592 		c->superspeed = 0;
1593 		c->highspeed = 0;
1594 		c->fullspeed = 0;
1595 	}
1596 }
1597 
1598 static struct usb_string *
1599 configfs_attach_gadget_strings(struct gadget_info *gi)
1600 {
1601 	struct usb_gadget_strings **gadget_strings;
1602 	struct gadget_language *language;
1603 	struct gadget_string *string;
1604 	unsigned int nlangs = 0;
1605 	struct list_head *iter;
1606 	struct usb_string *us;
1607 	unsigned int i = 0;
1608 	int nstrings = -1;
1609 	unsigned int j;
1610 
1611 	list_for_each(iter, &gi->string_list)
1612 		nlangs++;
1613 
1614 	/* Bail out early if no languages are configured */
1615 	if (!nlangs)
1616 		return NULL;
1617 
1618 	gadget_strings = kcalloc(nlangs + 1, /* including NULL terminator */
1619 				 sizeof(struct usb_gadget_strings *), GFP_KERNEL);
1620 	if (!gadget_strings)
1621 		return ERR_PTR(-ENOMEM);
1622 
1623 	list_for_each_entry(language, &gi->string_list, list) {
1624 		struct usb_string *stringtab;
1625 
1626 		if (nstrings == -1) {
1627 			nstrings = language->nstrings;
1628 		} else if (nstrings != language->nstrings) {
1629 			pr_err("languages must contain the same number of strings\n");
1630 			us = ERR_PTR(-EINVAL);
1631 			goto cleanup;
1632 		}
1633 
1634 		stringtab = kcalloc(language->nstrings + 1, sizeof(struct usb_string),
1635 				    GFP_KERNEL);
1636 		if (!stringtab) {
1637 			us = ERR_PTR(-ENOMEM);
1638 			goto cleanup;
1639 		}
1640 
1641 		stringtab[USB_GADGET_MANUFACTURER_IDX].id = USB_GADGET_MANUFACTURER_IDX;
1642 		stringtab[USB_GADGET_MANUFACTURER_IDX].s = language->manufacturer;
1643 		stringtab[USB_GADGET_PRODUCT_IDX].id = USB_GADGET_PRODUCT_IDX;
1644 		stringtab[USB_GADGET_PRODUCT_IDX].s = language->product;
1645 		stringtab[USB_GADGET_SERIAL_IDX].id = USB_GADGET_SERIAL_IDX;
1646 		stringtab[USB_GADGET_SERIAL_IDX].s = language->serialnumber;
1647 
1648 		j = USB_GADGET_FIRST_AVAIL_IDX;
1649 		list_for_each_entry(string, &language->gadget_strings, list) {
1650 			memcpy(&stringtab[j], &string->usb_string, sizeof(struct usb_string));
1651 			j++;
1652 		}
1653 
1654 		language->stringtab_dev.strings = stringtab;
1655 		gadget_strings[i] = &language->stringtab_dev;
1656 		i++;
1657 	}
1658 
1659 	us = usb_gstrings_attach(&gi->cdev, gadget_strings, nstrings);
1660 
1661 cleanup:
1662 	list_for_each_entry(language, &gi->string_list, list) {
1663 		kfree(language->stringtab_dev.strings);
1664 		language->stringtab_dev.strings = NULL;
1665 	}
1666 
1667 	kfree(gadget_strings);
1668 
1669 	return us;
1670 }
1671 
1672 static int configfs_composite_bind(struct usb_gadget *gadget,
1673 		struct usb_gadget_driver *gdriver)
1674 {
1675 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1676 	struct gadget_info		*gi = container_of(composite,
1677 						struct gadget_info, composite);
1678 	struct usb_composite_dev	*cdev = &gi->cdev;
1679 	struct usb_configuration	*c;
1680 	struct usb_string		*s;
1681 	unsigned			i;
1682 	int				ret;
1683 
1684 	/* the gi->lock is hold by the caller */
1685 	gi->unbind = 0;
1686 	cdev->gadget = gadget;
1687 	set_gadget_data(gadget, cdev);
1688 	ret = composite_dev_prepare(composite, cdev);
1689 	if (ret)
1690 		return ret;
1691 	/* and now the gadget bind */
1692 	ret = -EINVAL;
1693 
1694 	if (list_empty(&gi->cdev.configs)) {
1695 		pr_err("Need at least one configuration in %s.\n",
1696 				gi->composite.name);
1697 		goto err_comp_cleanup;
1698 	}
1699 
1700 
1701 	list_for_each_entry(c, &gi->cdev.configs, list) {
1702 		struct config_usb_cfg *cfg;
1703 
1704 		cfg = container_of(c, struct config_usb_cfg, c);
1705 		if (list_empty(&cfg->func_list)) {
1706 			pr_err("Config %s/%d of %s needs at least one function.\n",
1707 			      c->label, c->bConfigurationValue,
1708 			      gi->composite.name);
1709 			goto err_comp_cleanup;
1710 		}
1711 	}
1712 
1713 	/* init all strings */
1714 	if (!list_empty(&gi->string_list)) {
1715 		s = configfs_attach_gadget_strings(gi);
1716 		if (IS_ERR(s)) {
1717 			ret = PTR_ERR(s);
1718 			goto err_comp_cleanup;
1719 		}
1720 
1721 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1722 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1723 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1724 
1725 		gi->cdev.usb_strings = s;
1726 	}
1727 
1728 	if (gi->use_webusb) {
1729 		cdev->use_webusb = true;
1730 		cdev->bcd_webusb_version = gi->bcd_webusb_version;
1731 		cdev->b_webusb_vendor_code = gi->b_webusb_vendor_code;
1732 		memcpy(cdev->landing_page, gi->landing_page, WEBUSB_URL_RAW_MAX_LENGTH);
1733 	}
1734 
1735 	if (gi->use_os_desc) {
1736 		cdev->use_os_string = true;
1737 		cdev->b_vendor_code = gi->b_vendor_code;
1738 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1739 	}
1740 
1741 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1742 		struct usb_descriptor_header *usb_desc;
1743 
1744 		usb_desc = usb_otg_descriptor_alloc(gadget);
1745 		if (!usb_desc) {
1746 			ret = -ENOMEM;
1747 			goto err_comp_cleanup;
1748 		}
1749 		usb_otg_descriptor_init(gadget, usb_desc);
1750 		otg_desc[0] = usb_desc;
1751 		otg_desc[1] = NULL;
1752 	}
1753 
1754 	/* Go through all configs, attach all functions */
1755 	list_for_each_entry(c, &gi->cdev.configs, list) {
1756 		struct config_usb_cfg *cfg;
1757 		struct usb_function *f;
1758 		struct usb_function *tmp;
1759 		struct gadget_config_name *cn;
1760 
1761 		if (gadget_is_otg(gadget))
1762 			c->descriptors = otg_desc;
1763 
1764 		cfg = container_of(c, struct config_usb_cfg, c);
1765 		if (!list_empty(&cfg->string_list)) {
1766 			i = 0;
1767 			list_for_each_entry(cn, &cfg->string_list, list) {
1768 				cfg->gstrings[i] = &cn->stringtab_dev;
1769 				cn->stringtab_dev.strings = &cn->strings;
1770 				cn->strings.s = cn->configuration;
1771 				i++;
1772 			}
1773 			cfg->gstrings[i] = NULL;
1774 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1775 			if (IS_ERR(s)) {
1776 				ret = PTR_ERR(s);
1777 				goto err_comp_cleanup;
1778 			}
1779 			c->iConfiguration = s[0].id;
1780 		}
1781 
1782 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1783 			list_del(&f->list);
1784 			ret = usb_add_function(c, f);
1785 			if (ret) {
1786 				list_add(&f->list, &cfg->func_list);
1787 				goto err_purge_funcs;
1788 			}
1789 		}
1790 		ret = usb_gadget_check_config(cdev->gadget);
1791 		if (ret)
1792 			goto err_purge_funcs;
1793 
1794 		usb_ep_autoconfig_reset(cdev->gadget);
1795 	}
1796 	if (cdev->use_os_string) {
1797 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1798 		if (ret)
1799 			goto err_purge_funcs;
1800 	}
1801 
1802 	usb_ep_autoconfig_reset(cdev->gadget);
1803 	return 0;
1804 
1805 err_purge_funcs:
1806 	purge_configs_funcs(gi);
1807 err_comp_cleanup:
1808 	composite_dev_cleanup(cdev);
1809 	return ret;
1810 }
1811 
1812 static void configfs_composite_unbind(struct usb_gadget *gadget)
1813 {
1814 	struct usb_composite_dev	*cdev;
1815 	struct gadget_info		*gi;
1816 	unsigned long flags;
1817 
1818 	/* the gi->lock is hold by the caller */
1819 
1820 	cdev = get_gadget_data(gadget);
1821 	gi = container_of(cdev, struct gadget_info, cdev);
1822 	spin_lock_irqsave(&gi->spinlock, flags);
1823 	gi->unbind = 1;
1824 	spin_unlock_irqrestore(&gi->spinlock, flags);
1825 
1826 	kfree(otg_desc[0]);
1827 	otg_desc[0] = NULL;
1828 	purge_configs_funcs(gi);
1829 	composite_dev_cleanup(cdev);
1830 	usb_ep_autoconfig_reset(cdev->gadget);
1831 	spin_lock_irqsave(&gi->spinlock, flags);
1832 	cdev->gadget = NULL;
1833 	cdev->deactivations = 0;
1834 	gadget->deactivated = false;
1835 	set_gadget_data(gadget, NULL);
1836 	spin_unlock_irqrestore(&gi->spinlock, flags);
1837 }
1838 
1839 static int configfs_composite_setup(struct usb_gadget *gadget,
1840 		const struct usb_ctrlrequest *ctrl)
1841 {
1842 	struct usb_composite_dev *cdev;
1843 	struct gadget_info *gi;
1844 	unsigned long flags;
1845 	int ret;
1846 
1847 	cdev = get_gadget_data(gadget);
1848 	if (!cdev)
1849 		return 0;
1850 
1851 	gi = container_of(cdev, struct gadget_info, cdev);
1852 	spin_lock_irqsave(&gi->spinlock, flags);
1853 	cdev = get_gadget_data(gadget);
1854 	if (!cdev || gi->unbind) {
1855 		spin_unlock_irqrestore(&gi->spinlock, flags);
1856 		return 0;
1857 	}
1858 
1859 	ret = composite_setup(gadget, ctrl);
1860 	spin_unlock_irqrestore(&gi->spinlock, flags);
1861 	return ret;
1862 }
1863 
1864 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1865 {
1866 	struct usb_composite_dev *cdev;
1867 	struct gadget_info *gi;
1868 	unsigned long flags;
1869 
1870 	cdev = get_gadget_data(gadget);
1871 	if (!cdev)
1872 		return;
1873 
1874 	gi = container_of(cdev, struct gadget_info, cdev);
1875 	spin_lock_irqsave(&gi->spinlock, flags);
1876 	cdev = get_gadget_data(gadget);
1877 	if (!cdev || gi->unbind) {
1878 		spin_unlock_irqrestore(&gi->spinlock, flags);
1879 		return;
1880 	}
1881 
1882 	composite_disconnect(gadget);
1883 	spin_unlock_irqrestore(&gi->spinlock, flags);
1884 }
1885 
1886 static void configfs_composite_reset(struct usb_gadget *gadget)
1887 {
1888 	struct usb_composite_dev *cdev;
1889 	struct gadget_info *gi;
1890 	unsigned long flags;
1891 
1892 	cdev = get_gadget_data(gadget);
1893 	if (!cdev)
1894 		return;
1895 
1896 	gi = container_of(cdev, struct gadget_info, cdev);
1897 	spin_lock_irqsave(&gi->spinlock, flags);
1898 	cdev = get_gadget_data(gadget);
1899 	if (!cdev || gi->unbind) {
1900 		spin_unlock_irqrestore(&gi->spinlock, flags);
1901 		return;
1902 	}
1903 
1904 	composite_reset(gadget);
1905 	spin_unlock_irqrestore(&gi->spinlock, flags);
1906 }
1907 
1908 static void configfs_composite_suspend(struct usb_gadget *gadget)
1909 {
1910 	struct usb_composite_dev *cdev;
1911 	struct gadget_info *gi;
1912 	unsigned long flags;
1913 
1914 	cdev = get_gadget_data(gadget);
1915 	if (!cdev)
1916 		return;
1917 
1918 	gi = container_of(cdev, struct gadget_info, cdev);
1919 	spin_lock_irqsave(&gi->spinlock, flags);
1920 	cdev = get_gadget_data(gadget);
1921 	if (!cdev || gi->unbind) {
1922 		spin_unlock_irqrestore(&gi->spinlock, flags);
1923 		return;
1924 	}
1925 
1926 	composite_suspend(gadget);
1927 	spin_unlock_irqrestore(&gi->spinlock, flags);
1928 }
1929 
1930 static void configfs_composite_resume(struct usb_gadget *gadget)
1931 {
1932 	struct usb_composite_dev *cdev;
1933 	struct gadget_info *gi;
1934 	unsigned long flags;
1935 
1936 	cdev = get_gadget_data(gadget);
1937 	if (!cdev)
1938 		return;
1939 
1940 	gi = container_of(cdev, struct gadget_info, cdev);
1941 	spin_lock_irqsave(&gi->spinlock, flags);
1942 	cdev = get_gadget_data(gadget);
1943 	if (!cdev || gi->unbind) {
1944 		spin_unlock_irqrestore(&gi->spinlock, flags);
1945 		return;
1946 	}
1947 
1948 	composite_resume(gadget);
1949 	spin_unlock_irqrestore(&gi->spinlock, flags);
1950 }
1951 
1952 static const struct usb_gadget_driver configfs_driver_template = {
1953 	.bind           = configfs_composite_bind,
1954 	.unbind         = configfs_composite_unbind,
1955 
1956 	.setup          = configfs_composite_setup,
1957 	.reset          = configfs_composite_reset,
1958 	.disconnect     = configfs_composite_disconnect,
1959 
1960 	.suspend	= configfs_composite_suspend,
1961 	.resume		= configfs_composite_resume,
1962 
1963 	.max_speed	= USB_SPEED_SUPER_PLUS,
1964 	.driver = {
1965 		.owner          = THIS_MODULE,
1966 	},
1967 	.match_existing_only = 1,
1968 };
1969 
1970 static struct config_group *gadgets_make(
1971 		struct config_group *group,
1972 		const char *name)
1973 {
1974 	struct gadget_info *gi;
1975 
1976 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1977 	if (!gi)
1978 		return ERR_PTR(-ENOMEM);
1979 
1980 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1981 
1982 	config_group_init_type_name(&gi->functions_group, "functions",
1983 			&functions_type);
1984 	configfs_add_default_group(&gi->functions_group, &gi->group);
1985 
1986 	config_group_init_type_name(&gi->configs_group, "configs",
1987 			&config_desc_type);
1988 	configfs_add_default_group(&gi->configs_group, &gi->group);
1989 
1990 	config_group_init_type_name(&gi->strings_group, "strings",
1991 			&gadget_language_strings_type);
1992 	configfs_add_default_group(&gi->strings_group, &gi->group);
1993 
1994 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1995 			&os_desc_type);
1996 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1997 
1998 	config_group_init_type_name(&gi->webusb_group, "webusb",
1999 			&webusb_type);
2000 	configfs_add_default_group(&gi->webusb_group, &gi->group);
2001 
2002 	gi->composite.bind = configfs_do_nothing;
2003 	gi->composite.unbind = configfs_do_nothing;
2004 	gi->composite.suspend = NULL;
2005 	gi->composite.resume = NULL;
2006 	gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
2007 
2008 	spin_lock_init(&gi->spinlock);
2009 	mutex_init(&gi->lock);
2010 	INIT_LIST_HEAD(&gi->string_list);
2011 	INIT_LIST_HEAD(&gi->available_func);
2012 
2013 	composite_init_dev(&gi->cdev);
2014 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
2015 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
2016 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
2017 
2018 	gi->composite.gadget_driver = configfs_driver_template;
2019 
2020 	gi->composite.gadget_driver.driver.name = kasprintf(GFP_KERNEL,
2021 							    "configfs-gadget.%s", name);
2022 	if (!gi->composite.gadget_driver.driver.name)
2023 		goto err;
2024 
2025 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
2026 	gi->composite.name = gi->composite.gadget_driver.function;
2027 
2028 	if (!gi->composite.gadget_driver.function)
2029 		goto out_free_driver_name;
2030 
2031 	return &gi->group;
2032 
2033 out_free_driver_name:
2034 	kfree(gi->composite.gadget_driver.driver.name);
2035 err:
2036 	kfree(gi);
2037 	return ERR_PTR(-ENOMEM);
2038 }
2039 
2040 static void gadgets_drop(struct config_group *group, struct config_item *item)
2041 {
2042 	config_item_put(item);
2043 }
2044 
2045 static struct configfs_group_operations gadgets_ops = {
2046 	.make_group     = &gadgets_make,
2047 	.drop_item      = &gadgets_drop,
2048 };
2049 
2050 static const struct config_item_type gadgets_type = {
2051 	.ct_group_ops   = &gadgets_ops,
2052 	.ct_owner       = THIS_MODULE,
2053 };
2054 
2055 static struct configfs_subsystem gadget_subsys = {
2056 	.su_group = {
2057 		.cg_item = {
2058 			.ci_namebuf = "usb_gadget",
2059 			.ci_type = &gadgets_type,
2060 		},
2061 	},
2062 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
2063 };
2064 
2065 void unregister_gadget_item(struct config_item *item)
2066 {
2067 	struct gadget_info *gi = to_gadget_info(item);
2068 
2069 	mutex_lock(&gi->lock);
2070 	unregister_gadget(gi);
2071 	mutex_unlock(&gi->lock);
2072 }
2073 EXPORT_SYMBOL_GPL(unregister_gadget_item);
2074 
2075 static int __init gadget_cfs_init(void)
2076 {
2077 	int ret;
2078 
2079 	config_group_init(&gadget_subsys.su_group);
2080 
2081 	ret = configfs_register_subsystem(&gadget_subsys);
2082 	return ret;
2083 }
2084 module_init(gadget_cfs_init);
2085 
2086 static void __exit gadget_cfs_exit(void)
2087 {
2088 	configfs_unregister_subsystem(&gadget_subsys);
2089 }
2090 module_exit(gadget_cfs_exit);
2091