xref: /linux/drivers/usb/gadget/configfs.c (revision a634dda26186cf9a51567020fcce52bcba5e1e59)
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/func_utils.h>
10 #include <linux/usb/gadget_configfs.h>
11 #include <linux/usb/webusb.h>
12 #include "configfs.h"
13 #include "u_os_desc.h"
14 
15 static 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 
119 	ret = strlen(s);
120 	if (ret > USB_MAX_STRING_LEN)
121 		return -EOVERFLOW;
122 	if (ret < 1)
123 		return -EINVAL;
124 
125 	if (copy) {
126 		str = copy;
127 	} else {
128 		str = kmalloc(USB_MAX_STRING_WITH_NULL_LEN, GFP_KERNEL);
129 		if (!str)
130 			return -ENOMEM;
131 	}
132 	strcpy(str, s);
133 	if (str[ret - 1] == '\n')
134 		str[ret - 1] = '\0';
135 	*s_copy = str;
136 	return 0;
137 }
138 
139 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
140 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
141 			char *page)	\
142 {	\
143 	return sprintf(page, "0x%02x\n", \
144 		to_gadget_info(item)->cdev.desc.__name); \
145 }
146 
147 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
148 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
149 			char *page)	\
150 {	\
151 	return sprintf(page, "0x%04x\n", \
152 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
153 }
154 
155 
156 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
157 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
158 		const char *page, size_t len)		\
159 {							\
160 	u8 val;						\
161 	int ret;					\
162 	ret = kstrtou8(page, 0, &val);			\
163 	if (ret)					\
164 		return ret;				\
165 	to_gadget_info(item)->cdev.desc._name = val;	\
166 	return len;					\
167 }
168 
169 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
170 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
171 		const char *page, size_t len)		\
172 {							\
173 	u16 val;					\
174 	int ret;					\
175 	ret = kstrtou16(page, 0, &val);			\
176 	if (ret)					\
177 		return ret;				\
178 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
179 	return len;					\
180 }
181 
182 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
183 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
184 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
185 
186 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
187 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
188 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
189 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
190 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
191 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
192 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
193 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
194 
195 static ssize_t is_valid_bcd(u16 bcd_val)
196 {
197 	if ((bcd_val & 0xf) > 9)
198 		return -EINVAL;
199 	if (((bcd_val >> 4) & 0xf) > 9)
200 		return -EINVAL;
201 	if (((bcd_val >> 8) & 0xf) > 9)
202 		return -EINVAL;
203 	if (((bcd_val >> 12) & 0xf) > 9)
204 		return -EINVAL;
205 	return 0;
206 }
207 
208 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
209 		const char *page, size_t len)
210 {
211 	u16 bcdDevice;
212 	int ret;
213 
214 	ret = kstrtou16(page, 0, &bcdDevice);
215 	if (ret)
216 		return ret;
217 	ret = is_valid_bcd(bcdDevice);
218 	if (ret)
219 		return ret;
220 
221 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
222 	return len;
223 }
224 
225 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
226 		const char *page, size_t len)
227 {
228 	u16 bcdUSB;
229 	int ret;
230 
231 	ret = kstrtou16(page, 0, &bcdUSB);
232 	if (ret)
233 		return ret;
234 	ret = is_valid_bcd(bcdUSB);
235 	if (ret)
236 		return ret;
237 
238 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
239 	return len;
240 }
241 
242 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
243 {
244 	struct gadget_info *gi = to_gadget_info(item);
245 	char *udc_name;
246 	int ret;
247 
248 	mutex_lock(&gi->lock);
249 	udc_name = gi->composite.gadget_driver.udc_name;
250 	ret = sprintf(page, "%s\n", udc_name ?: "");
251 	mutex_unlock(&gi->lock);
252 
253 	return ret;
254 }
255 
256 static int unregister_gadget(struct gadget_info *gi)
257 {
258 	int ret;
259 
260 	if (!gi->composite.gadget_driver.udc_name)
261 		return -ENODEV;
262 
263 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
264 	if (ret)
265 		return ret;
266 	kfree(gi->composite.gadget_driver.udc_name);
267 	gi->composite.gadget_driver.udc_name = NULL;
268 	return 0;
269 }
270 
271 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
272 		const char *page, size_t len)
273 {
274 	struct gadget_info *gi = to_gadget_info(item);
275 	char *name;
276 	int ret;
277 
278 	if (strlen(page) < len)
279 		return -EOVERFLOW;
280 
281 	name = kstrdup(page, GFP_KERNEL);
282 	if (!name)
283 		return -ENOMEM;
284 	if (name[len - 1] == '\n')
285 		name[len - 1] = '\0';
286 
287 	mutex_lock(&gi->lock);
288 
289 	if (!strlen(name)) {
290 		ret = unregister_gadget(gi);
291 		if (ret)
292 			goto err;
293 		kfree(name);
294 	} else {
295 		if (gi->composite.gadget_driver.udc_name) {
296 			ret = -EBUSY;
297 			goto err;
298 		}
299 		gi->composite.gadget_driver.udc_name = name;
300 		ret = usb_gadget_register_driver(&gi->composite.gadget_driver);
301 		if (ret) {
302 			gi->composite.gadget_driver.udc_name = NULL;
303 			goto err;
304 		}
305 	}
306 	mutex_unlock(&gi->lock);
307 	return len;
308 err:
309 	kfree(name);
310 	mutex_unlock(&gi->lock);
311 	return ret;
312 }
313 
314 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
315 					      char *page)
316 {
317 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
318 
319 	return sprintf(page, "%s\n", usb_speed_string(speed));
320 }
321 
322 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
323 					       const char *page, size_t len)
324 {
325 	struct gadget_info *gi = to_gadget_info(item);
326 
327 	mutex_lock(&gi->lock);
328 
329 	/* Prevent changing of max_speed after the driver is binded */
330 	if (gi->composite.gadget_driver.udc_name)
331 		goto err;
332 
333 	if (strncmp(page, "super-speed-plus", 16) == 0)
334 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
335 	else if (strncmp(page, "super-speed", 11) == 0)
336 		gi->composite.max_speed = USB_SPEED_SUPER;
337 	else if (strncmp(page, "high-speed", 10) == 0)
338 		gi->composite.max_speed = USB_SPEED_HIGH;
339 	else if (strncmp(page, "full-speed", 10) == 0)
340 		gi->composite.max_speed = USB_SPEED_FULL;
341 	else if (strncmp(page, "low-speed", 9) == 0)
342 		gi->composite.max_speed = USB_SPEED_LOW;
343 	else
344 		goto err;
345 
346 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
347 
348 	mutex_unlock(&gi->lock);
349 	return len;
350 err:
351 	mutex_unlock(&gi->lock);
352 	return -EINVAL;
353 }
354 
355 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
356 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
357 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
358 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
359 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
360 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
361 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
362 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
363 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
364 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
365 
366 static struct configfs_attribute *gadget_root_attrs[] = {
367 	&gadget_dev_desc_attr_bDeviceClass,
368 	&gadget_dev_desc_attr_bDeviceSubClass,
369 	&gadget_dev_desc_attr_bDeviceProtocol,
370 	&gadget_dev_desc_attr_bMaxPacketSize0,
371 	&gadget_dev_desc_attr_idVendor,
372 	&gadget_dev_desc_attr_idProduct,
373 	&gadget_dev_desc_attr_bcdDevice,
374 	&gadget_dev_desc_attr_bcdUSB,
375 	&gadget_dev_desc_attr_UDC,
376 	&gadget_dev_desc_attr_max_speed,
377 	NULL,
378 };
379 
380 static inline struct gadget_language *to_gadget_language(struct config_item *item)
381 {
382 	return container_of(to_config_group(item), struct gadget_language,
383 			 group);
384 }
385 
386 static inline struct gadget_config_name *to_gadget_config_name(
387 		struct config_item *item)
388 {
389 	return container_of(to_config_group(item), struct gadget_config_name,
390 			 group);
391 }
392 
393 static inline struct usb_function_instance *to_usb_function_instance(
394 		struct config_item *item)
395 {
396 	return container_of(to_config_group(item),
397 			 struct usb_function_instance, group);
398 }
399 
400 static void gadget_info_attr_release(struct config_item *item)
401 {
402 	struct gadget_info *gi = to_gadget_info(item);
403 
404 	WARN_ON(!list_empty(&gi->cdev.configs));
405 	WARN_ON(!list_empty(&gi->string_list));
406 	WARN_ON(!list_empty(&gi->available_func));
407 	kfree(gi->composite.gadget_driver.function);
408 	kfree(gi->composite.gadget_driver.driver.name);
409 	kfree(gi);
410 }
411 
412 static struct configfs_item_operations gadget_root_item_ops = {
413 	.release                = gadget_info_attr_release,
414 };
415 
416 static void gadget_config_attr_release(struct config_item *item)
417 {
418 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
419 
420 	WARN_ON(!list_empty(&cfg->c.functions));
421 	list_del(&cfg->c.list);
422 	kfree(cfg->c.label);
423 	kfree(cfg);
424 }
425 
426 static int config_usb_cfg_link(
427 	struct config_item *usb_cfg_ci,
428 	struct config_item *usb_func_ci)
429 {
430 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
431 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
432 
433 	struct usb_function_instance *fi =
434 			to_usb_function_instance(usb_func_ci);
435 	struct usb_function_instance *a_fi = NULL, *iter;
436 	struct usb_function *f;
437 	int ret;
438 
439 	mutex_lock(&gi->lock);
440 	/*
441 	 * Make sure this function is from within our _this_ gadget and not
442 	 * from another gadget or a random directory.
443 	 * Also a function instance can only be linked once.
444 	 */
445 
446 	if (gi->composite.gadget_driver.udc_name) {
447 		ret = -EINVAL;
448 		goto out;
449 	}
450 
451 	list_for_each_entry(iter, &gi->available_func, cfs_list) {
452 		if (iter != fi)
453 			continue;
454 		a_fi = iter;
455 		break;
456 	}
457 	if (!a_fi) {
458 		ret = -EINVAL;
459 		goto out;
460 	}
461 
462 	list_for_each_entry(f, &cfg->func_list, list) {
463 		if (f->fi == fi) {
464 			ret = -EEXIST;
465 			goto out;
466 		}
467 	}
468 
469 	f = usb_get_function(fi);
470 	if (IS_ERR(f)) {
471 		ret = PTR_ERR(f);
472 		goto out;
473 	}
474 
475 	/* stash the function until we bind it to the gadget */
476 	list_add_tail(&f->list, &cfg->func_list);
477 	ret = 0;
478 out:
479 	mutex_unlock(&gi->lock);
480 	return ret;
481 }
482 
483 static void config_usb_cfg_unlink(
484 	struct config_item *usb_cfg_ci,
485 	struct config_item *usb_func_ci)
486 {
487 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
488 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
489 
490 	struct usb_function_instance *fi =
491 			to_usb_function_instance(usb_func_ci);
492 	struct usb_function *f;
493 
494 	/*
495 	 * ideally I would like to forbid to unlink functions while a gadget is
496 	 * bound to an UDC. Since this isn't possible at the moment, we simply
497 	 * force an unbind, the function is available here and then we can
498 	 * remove the function.
499 	 */
500 	mutex_lock(&gi->lock);
501 	if (gi->composite.gadget_driver.udc_name)
502 		unregister_gadget(gi);
503 	WARN_ON(gi->composite.gadget_driver.udc_name);
504 
505 	list_for_each_entry(f, &cfg->func_list, list) {
506 		if (f->fi == fi) {
507 			list_del(&f->list);
508 			usb_put_function(f);
509 			mutex_unlock(&gi->lock);
510 			return;
511 		}
512 	}
513 	mutex_unlock(&gi->lock);
514 	WARN(1, "Unable to locate function to unbind\n");
515 }
516 
517 static struct configfs_item_operations gadget_config_item_ops = {
518 	.release                = gadget_config_attr_release,
519 	.allow_link             = config_usb_cfg_link,
520 	.drop_link              = config_usb_cfg_unlink,
521 };
522 
523 
524 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
525 		char *page)
526 {
527 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
528 
529 	return sprintf(page, "%u\n", cfg->c.MaxPower);
530 }
531 
532 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
533 		const char *page, size_t len)
534 {
535 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
536 	u16 val;
537 	int ret;
538 	ret = kstrtou16(page, 0, &val);
539 	if (ret)
540 		return ret;
541 	if (DIV_ROUND_UP(val, 8) > 0xff)
542 		return -ERANGE;
543 	cfg->c.MaxPower = val;
544 	return len;
545 }
546 
547 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
548 		char *page)
549 {
550 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
551 
552 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
553 }
554 
555 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
556 		const char *page, size_t len)
557 {
558 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
559 	u8 val;
560 	int ret;
561 	ret = kstrtou8(page, 0, &val);
562 	if (ret)
563 		return ret;
564 	if (!(val & USB_CONFIG_ATT_ONE))
565 		return -EINVAL;
566 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
567 				USB_CONFIG_ATT_WAKEUP))
568 		return -EINVAL;
569 	cfg->c.bmAttributes = val;
570 	return len;
571 }
572 
573 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
574 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
575 
576 static struct configfs_attribute *gadget_config_attrs[] = {
577 	&gadget_config_desc_attr_MaxPower,
578 	&gadget_config_desc_attr_bmAttributes,
579 	NULL,
580 };
581 
582 static const struct config_item_type gadget_config_type = {
583 	.ct_item_ops	= &gadget_config_item_ops,
584 	.ct_attrs	= gadget_config_attrs,
585 	.ct_owner	= THIS_MODULE,
586 };
587 
588 static const struct config_item_type gadget_root_type = {
589 	.ct_item_ops	= &gadget_root_item_ops,
590 	.ct_attrs	= gadget_root_attrs,
591 	.ct_owner	= THIS_MODULE,
592 };
593 
594 static void composite_init_dev(struct usb_composite_dev *cdev)
595 {
596 	spin_lock_init(&cdev->lock);
597 	INIT_LIST_HEAD(&cdev->configs);
598 	INIT_LIST_HEAD(&cdev->gstrings);
599 }
600 
601 static struct config_group *function_make(
602 		struct config_group *group,
603 		const char *name)
604 {
605 	struct gadget_info *gi;
606 	struct usb_function_instance *fi;
607 	char buf[MAX_NAME_LEN];
608 	char *func_name;
609 	char *instance_name;
610 	int ret;
611 
612 	if (strlen(name) >= MAX_NAME_LEN)
613 		return ERR_PTR(-ENAMETOOLONG);
614 
615 	scnprintf(buf, MAX_NAME_LEN, "%s", name);
616 
617 	func_name = buf;
618 	instance_name = strchr(func_name, '.');
619 	if (!instance_name) {
620 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
621 		return ERR_PTR(-EINVAL);
622 	}
623 	*instance_name = '\0';
624 	instance_name++;
625 
626 	fi = usb_get_function_instance(func_name);
627 	if (IS_ERR(fi))
628 		return ERR_CAST(fi);
629 
630 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
631 	if (ret) {
632 		usb_put_function_instance(fi);
633 		return ERR_PTR(ret);
634 	}
635 	if (fi->set_inst_name) {
636 		ret = fi->set_inst_name(fi, instance_name);
637 		if (ret) {
638 			usb_put_function_instance(fi);
639 			return ERR_PTR(ret);
640 		}
641 	}
642 
643 	gi = container_of(group, struct gadget_info, functions_group);
644 
645 	mutex_lock(&gi->lock);
646 	list_add_tail(&fi->cfs_list, &gi->available_func);
647 	mutex_unlock(&gi->lock);
648 	return &fi->group;
649 }
650 
651 static void function_drop(
652 		struct config_group *group,
653 		struct config_item *item)
654 {
655 	struct usb_function_instance *fi = to_usb_function_instance(item);
656 	struct gadget_info *gi;
657 
658 	gi = container_of(group, struct gadget_info, functions_group);
659 
660 	mutex_lock(&gi->lock);
661 	list_del(&fi->cfs_list);
662 	mutex_unlock(&gi->lock);
663 	config_item_put(item);
664 }
665 
666 static struct configfs_group_operations functions_ops = {
667 	.make_group     = &function_make,
668 	.drop_item      = &function_drop,
669 };
670 
671 static const struct config_item_type functions_type = {
672 	.ct_group_ops   = &functions_ops,
673 	.ct_owner       = THIS_MODULE,
674 };
675 
676 GS_STRINGS_RW(gadget_config_name, configuration);
677 
678 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
679 	&gadget_config_name_attr_configuration,
680 	NULL,
681 };
682 
683 static void gadget_config_name_attr_release(struct config_item *item)
684 {
685 	struct gadget_config_name *cn = to_gadget_config_name(item);
686 
687 	kfree(cn->configuration);
688 
689 	list_del(&cn->list);
690 	kfree(cn);
691 }
692 
693 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
694 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
695 
696 static struct config_group *config_desc_make(
697 		struct config_group *group,
698 		const char *name)
699 {
700 	struct gadget_info *gi;
701 	struct config_usb_cfg *cfg;
702 	char buf[MAX_NAME_LEN];
703 	char *num_str;
704 	u8 num;
705 	int ret;
706 
707 	gi = container_of(group, struct gadget_info, configs_group);
708 
709 	if (strlen(name) >= MAX_NAME_LEN)
710 		return ERR_PTR(-ENAMETOOLONG);
711 
712 	scnprintf(buf, MAX_NAME_LEN, "%s", name);
713 
714 	num_str = strchr(buf, '.');
715 	if (!num_str) {
716 		pr_err("Unable to locate . in name.bConfigurationValue\n");
717 		return ERR_PTR(-EINVAL);
718 	}
719 
720 	*num_str = '\0';
721 	num_str++;
722 
723 	if (!strlen(buf))
724 		return ERR_PTR(-EINVAL);
725 
726 	ret = kstrtou8(num_str, 0, &num);
727 	if (ret)
728 		return ERR_PTR(ret);
729 
730 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
731 	if (!cfg)
732 		return ERR_PTR(-ENOMEM);
733 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
734 	if (!cfg->c.label) {
735 		ret = -ENOMEM;
736 		goto err;
737 	}
738 	cfg->c.bConfigurationValue = num;
739 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
740 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
741 	INIT_LIST_HEAD(&cfg->string_list);
742 	INIT_LIST_HEAD(&cfg->func_list);
743 
744 	config_group_init_type_name(&cfg->group, name,
745 				&gadget_config_type);
746 
747 	config_group_init_type_name(&cfg->strings_group, "strings",
748 			&gadget_config_name_strings_type);
749 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
750 
751 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
752 	if (ret)
753 		goto err;
754 
755 	return &cfg->group;
756 err:
757 	kfree(cfg->c.label);
758 	kfree(cfg);
759 	return ERR_PTR(ret);
760 }
761 
762 static void config_desc_drop(
763 		struct config_group *group,
764 		struct config_item *item)
765 {
766 	config_item_put(item);
767 }
768 
769 static struct configfs_group_operations config_desc_ops = {
770 	.make_group     = &config_desc_make,
771 	.drop_item      = &config_desc_drop,
772 };
773 
774 static const struct config_item_type config_desc_type = {
775 	.ct_group_ops   = &config_desc_ops,
776 	.ct_owner       = THIS_MODULE,
777 };
778 
779 GS_STRINGS_RW(gadget_language, manufacturer);
780 GS_STRINGS_RW(gadget_language, product);
781 GS_STRINGS_RW(gadget_language, serialnumber);
782 
783 static struct configfs_attribute *gadget_language_langid_attrs[] = {
784 	&gadget_language_attr_manufacturer,
785 	&gadget_language_attr_product,
786 	&gadget_language_attr_serialnumber,
787 	NULL,
788 };
789 
790 static void gadget_language_attr_release(struct config_item *item)
791 {
792 	struct gadget_language *gs = to_gadget_language(item);
793 
794 	kfree(gs->manufacturer);
795 	kfree(gs->product);
796 	kfree(gs->serialnumber);
797 
798 	list_del(&gs->list);
799 	kfree(gs);
800 }
801 
802 static struct configfs_item_operations gadget_language_langid_item_ops = {
803 	.release                = gadget_language_attr_release,
804 };
805 
806 static ssize_t gadget_string_id_show(struct config_item *item, char *page)
807 {
808 	struct gadget_string *string = to_gadget_string(item);
809 	int ret;
810 
811 	ret = sprintf(page, "%u\n", string->usb_string.id);
812 	return ret;
813 }
814 CONFIGFS_ATTR_RO(gadget_string_, id);
815 
816 static ssize_t gadget_string_s_show(struct config_item *item, char *page)
817 {
818 	struct gadget_string *string = to_gadget_string(item);
819 	int ret;
820 
821 	ret = sysfs_emit(page, "%s\n", string->string);
822 	return ret;
823 }
824 
825 static ssize_t gadget_string_s_store(struct config_item *item, const char *page,
826 				     size_t len)
827 {
828 	struct gadget_string *string = to_gadget_string(item);
829 	int size = min(sizeof(string->string), len + 1);
830 	ssize_t cpy_len;
831 
832 	if (len > USB_MAX_STRING_LEN)
833 		return -EINVAL;
834 
835 	cpy_len = strscpy(string->string, page, size);
836 	if (cpy_len > 0 && string->string[cpy_len - 1] == '\n')
837 		string->string[cpy_len - 1] = 0;
838 	return len;
839 }
840 CONFIGFS_ATTR(gadget_string_, s);
841 
842 static struct configfs_attribute *gadget_string_attrs[] = {
843 	&gadget_string_attr_id,
844 	&gadget_string_attr_s,
845 	NULL,
846 };
847 
848 static void gadget_string_release(struct config_item *item)
849 {
850 	struct gadget_string *string = to_gadget_string(item);
851 
852 	kfree(string);
853 }
854 
855 static struct configfs_item_operations gadget_string_item_ops = {
856 	.release	= gadget_string_release,
857 };
858 
859 static const struct config_item_type gadget_string_type = {
860 	.ct_item_ops	= &gadget_string_item_ops,
861 	.ct_attrs	= gadget_string_attrs,
862 	.ct_owner	= THIS_MODULE,
863 };
864 
865 static struct config_item *gadget_language_string_make(struct config_group *group,
866 						       const char *name)
867 {
868 	struct gadget_language *language;
869 	struct gadget_string *string;
870 
871 	language = to_gadget_language(&group->cg_item);
872 
873 	string = kzalloc(sizeof(*string), GFP_KERNEL);
874 	if (!string)
875 		return ERR_PTR(-ENOMEM);
876 
877 	string->usb_string.id = language->nstrings++;
878 	string->usb_string.s = string->string;
879 	list_add_tail(&string->list, &language->gadget_strings);
880 
881 	config_item_init_type_name(&string->item, name, &gadget_string_type);
882 
883 	return &string->item;
884 }
885 
886 static void gadget_language_string_drop(struct config_group *group,
887 					struct config_item *item)
888 {
889 	struct gadget_language *language;
890 	struct gadget_string *string;
891 	unsigned int i = USB_GADGET_FIRST_AVAIL_IDX;
892 
893 	language = to_gadget_language(&group->cg_item);
894 	string = to_gadget_string(item);
895 
896 	list_del(&string->list);
897 	language->nstrings--;
898 
899 	/* Reset the ids for the language's strings to guarantee a continuous set */
900 	list_for_each_entry(string, &language->gadget_strings, list)
901 		string->usb_string.id = i++;
902 }
903 
904 static struct configfs_group_operations gadget_language_langid_group_ops = {
905 	.make_item		= gadget_language_string_make,
906 	.drop_item		= gadget_language_string_drop,
907 };
908 
909 static const struct config_item_type gadget_language_type = {
910 	.ct_item_ops	= &gadget_language_langid_item_ops,
911 	.ct_group_ops	= &gadget_language_langid_group_ops,
912 	.ct_attrs	= gadget_language_langid_attrs,
913 	.ct_owner	= THIS_MODULE,
914 };
915 
916 static struct config_group *gadget_language_make(struct config_group *group,
917 						 const char *name)
918 {
919 	struct gadget_info *gi;
920 	struct gadget_language *gs;
921 	struct gadget_language *new;
922 	int langs = 0;
923 	int ret;
924 
925 	new = kzalloc(sizeof(*new), GFP_KERNEL);
926 	if (!new)
927 		return ERR_PTR(-ENOMEM);
928 
929 	ret = check_user_usb_string(name, &new->stringtab_dev);
930 	if (ret)
931 		goto err;
932 	config_group_init_type_name(&new->group, name,
933 				    &gadget_language_type);
934 
935 	gi = container_of(group, struct gadget_info, strings_group);
936 	ret = -EEXIST;
937 	list_for_each_entry(gs, &gi->string_list, list) {
938 		if (gs->stringtab_dev.language == new->stringtab_dev.language)
939 			goto err;
940 		langs++;
941 	}
942 	ret = -EOVERFLOW;
943 	if (langs >= MAX_USB_STRING_LANGS)
944 		goto err;
945 
946 	list_add_tail(&new->list, &gi->string_list);
947 	INIT_LIST_HEAD(&new->gadget_strings);
948 
949 	/* We have the default manufacturer, product and serialnumber strings */
950 	new->nstrings = 3;
951 	return &new->group;
952 err:
953 	kfree(new);
954 	return ERR_PTR(ret);
955 }
956 
957 static void gadget_language_drop(struct config_group *group,
958 				 struct config_item *item)
959 {
960 	config_item_put(item);
961 }
962 
963 static struct configfs_group_operations gadget_language_group_ops = {
964 	.make_group     = &gadget_language_make,
965 	.drop_item      = &gadget_language_drop,
966 };
967 
968 static const struct config_item_type gadget_language_strings_type = {
969 	.ct_group_ops   = &gadget_language_group_ops,
970 	.ct_owner       = THIS_MODULE,
971 };
972 
973 static inline struct gadget_info *webusb_item_to_gadget_info(
974 		struct config_item *item)
975 {
976 	return container_of(to_config_group(item),
977 			struct gadget_info, webusb_group);
978 }
979 
980 static ssize_t webusb_use_show(struct config_item *item, char *page)
981 {
982 	return sysfs_emit(page, "%d\n",
983 			webusb_item_to_gadget_info(item)->use_webusb);
984 }
985 
986 static ssize_t webusb_use_store(struct config_item *item, const char *page,
987 				 size_t len)
988 {
989 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
990 	int ret;
991 	bool use;
992 
993 	ret = kstrtobool(page, &use);
994 	if (ret)
995 		return ret;
996 
997 	mutex_lock(&gi->lock);
998 	gi->use_webusb = use;
999 	mutex_unlock(&gi->lock);
1000 
1001 	return len;
1002 }
1003 
1004 static ssize_t webusb_bcdVersion_show(struct config_item *item, char *page)
1005 {
1006 	return sysfs_emit(page, "0x%04x\n",
1007 					webusb_item_to_gadget_info(item)->bcd_webusb_version);
1008 }
1009 
1010 static ssize_t webusb_bcdVersion_store(struct config_item *item,
1011 		const char *page, size_t len)
1012 {
1013 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1014 	u16 bcdVersion;
1015 	int ret;
1016 
1017 	ret = kstrtou16(page, 0, &bcdVersion);
1018 	if (ret)
1019 		return ret;
1020 
1021 	ret = is_valid_bcd(bcdVersion);
1022 	if (ret)
1023 		return ret;
1024 
1025 	mutex_lock(&gi->lock);
1026 	gi->bcd_webusb_version = bcdVersion;
1027 	mutex_unlock(&gi->lock);
1028 
1029 	return len;
1030 }
1031 
1032 static ssize_t webusb_bVendorCode_show(struct config_item *item, char *page)
1033 {
1034 	return sysfs_emit(page, "0x%02x\n",
1035 			webusb_item_to_gadget_info(item)->b_webusb_vendor_code);
1036 }
1037 
1038 static ssize_t webusb_bVendorCode_store(struct config_item *item,
1039 					   const char *page, size_t len)
1040 {
1041 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1042 	int ret;
1043 	u8 b_vendor_code;
1044 
1045 	ret = kstrtou8(page, 0, &b_vendor_code);
1046 	if (ret)
1047 		return ret;
1048 
1049 	mutex_lock(&gi->lock);
1050 	gi->b_webusb_vendor_code = b_vendor_code;
1051 	mutex_unlock(&gi->lock);
1052 
1053 	return len;
1054 }
1055 
1056 static ssize_t webusb_landingPage_show(struct config_item *item, char *page)
1057 {
1058 	return sysfs_emit(page, "%s\n", webusb_item_to_gadget_info(item)->landing_page);
1059 }
1060 
1061 static ssize_t webusb_landingPage_store(struct config_item *item, const char *page,
1062 				     size_t len)
1063 {
1064 	struct gadget_info *gi = webusb_item_to_gadget_info(item);
1065 	unsigned int bytes_to_strip = 0;
1066 	int l = len;
1067 
1068 	if (page[l - 1] == '\n') {
1069 		--l;
1070 		++bytes_to_strip;
1071 	}
1072 
1073 	if (l > sizeof(gi->landing_page)) {
1074 		pr_err("webusb: landingPage URL too long\n");
1075 		return -EINVAL;
1076 	}
1077 
1078 	// validation
1079 	if (strncasecmp(page, "https://",  8) == 0)
1080 		bytes_to_strip = 8;
1081 	else if (strncasecmp(page, "http://", 7) == 0)
1082 		bytes_to_strip = 7;
1083 	else
1084 		bytes_to_strip = 0;
1085 
1086 	if (l > U8_MAX - WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + bytes_to_strip) {
1087 		pr_err("webusb: landingPage URL %d bytes too long for given URL scheme\n",
1088 			l - U8_MAX + WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH - bytes_to_strip);
1089 		return -EINVAL;
1090 	}
1091 
1092 	mutex_lock(&gi->lock);
1093 	// ensure 0 bytes are set, in case the new landing page is shorter then the old one.
1094 	memcpy_and_pad(gi->landing_page, sizeof(gi->landing_page), page, l, 0);
1095 	mutex_unlock(&gi->lock);
1096 
1097 	return len;
1098 }
1099 
1100 CONFIGFS_ATTR(webusb_, use);
1101 CONFIGFS_ATTR(webusb_, bVendorCode);
1102 CONFIGFS_ATTR(webusb_, bcdVersion);
1103 CONFIGFS_ATTR(webusb_, landingPage);
1104 
1105 static struct configfs_attribute *webusb_attrs[] = {
1106 	&webusb_attr_use,
1107 	&webusb_attr_bcdVersion,
1108 	&webusb_attr_bVendorCode,
1109 	&webusb_attr_landingPage,
1110 	NULL,
1111 };
1112 
1113 static const struct config_item_type webusb_type = {
1114 	.ct_attrs	= webusb_attrs,
1115 	.ct_owner	= THIS_MODULE,
1116 };
1117 
1118 static inline struct gadget_info *os_desc_item_to_gadget_info(
1119 		struct config_item *item)
1120 {
1121 	return container_of(to_config_group(item),
1122 			struct gadget_info, os_desc_group);
1123 }
1124 
1125 static ssize_t os_desc_use_show(struct config_item *item, char *page)
1126 {
1127 	return sprintf(page, "%d\n",
1128 			os_desc_item_to_gadget_info(item)->use_os_desc);
1129 }
1130 
1131 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
1132 				 size_t len)
1133 {
1134 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1135 	int ret;
1136 	bool use;
1137 
1138 	ret = kstrtobool(page, &use);
1139 	if (ret)
1140 		return ret;
1141 
1142 	mutex_lock(&gi->lock);
1143 	gi->use_os_desc = use;
1144 	mutex_unlock(&gi->lock);
1145 
1146 	return len;
1147 }
1148 
1149 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
1150 {
1151 	return sprintf(page, "0x%02x\n",
1152 			os_desc_item_to_gadget_info(item)->b_vendor_code);
1153 }
1154 
1155 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
1156 					   const char *page, size_t len)
1157 {
1158 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1159 	int ret;
1160 	u8 b_vendor_code;
1161 
1162 	ret = kstrtou8(page, 0, &b_vendor_code);
1163 	if (ret)
1164 		return ret;
1165 
1166 	mutex_lock(&gi->lock);
1167 	gi->b_vendor_code = b_vendor_code;
1168 	mutex_unlock(&gi->lock);
1169 
1170 	return len;
1171 }
1172 
1173 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
1174 {
1175 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1176 	int res;
1177 
1178 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
1179 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
1180 	page[res++] = '\n';
1181 
1182 	return res;
1183 }
1184 
1185 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
1186 				     size_t len)
1187 {
1188 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
1189 	int res, l;
1190 
1191 	l = min_t(int, len, OS_STRING_QW_SIGN_LEN >> 1);
1192 	if (page[l - 1] == '\n')
1193 		--l;
1194 
1195 	mutex_lock(&gi->lock);
1196 	res = utf8s_to_utf16s(page, l,
1197 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
1198 			      OS_STRING_QW_SIGN_LEN);
1199 	if (res > 0)
1200 		res = len;
1201 	mutex_unlock(&gi->lock);
1202 
1203 	return res;
1204 }
1205 
1206 CONFIGFS_ATTR(os_desc_, use);
1207 CONFIGFS_ATTR(os_desc_, b_vendor_code);
1208 CONFIGFS_ATTR(os_desc_, qw_sign);
1209 
1210 static struct configfs_attribute *os_desc_attrs[] = {
1211 	&os_desc_attr_use,
1212 	&os_desc_attr_b_vendor_code,
1213 	&os_desc_attr_qw_sign,
1214 	NULL,
1215 };
1216 
1217 static int os_desc_link(struct config_item *os_desc_ci,
1218 			struct config_item *usb_cfg_ci)
1219 {
1220 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
1221 	struct usb_composite_dev *cdev = &gi->cdev;
1222 	struct config_usb_cfg *c_target = to_config_usb_cfg(usb_cfg_ci);
1223 	struct usb_configuration *c = NULL, *iter;
1224 	int ret;
1225 
1226 	mutex_lock(&gi->lock);
1227 	list_for_each_entry(iter, &cdev->configs, list) {
1228 		if (iter != &c_target->c)
1229 			continue;
1230 		c = iter;
1231 		break;
1232 	}
1233 	if (!c) {
1234 		ret = -EINVAL;
1235 		goto out;
1236 	}
1237 
1238 	if (cdev->os_desc_config) {
1239 		ret = -EBUSY;
1240 		goto out;
1241 	}
1242 
1243 	cdev->os_desc_config = &c_target->c;
1244 	ret = 0;
1245 
1246 out:
1247 	mutex_unlock(&gi->lock);
1248 	return ret;
1249 }
1250 
1251 static void os_desc_unlink(struct config_item *os_desc_ci,
1252 			  struct config_item *usb_cfg_ci)
1253 {
1254 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
1255 	struct usb_composite_dev *cdev = &gi->cdev;
1256 
1257 	mutex_lock(&gi->lock);
1258 	if (gi->composite.gadget_driver.udc_name)
1259 		unregister_gadget(gi);
1260 	cdev->os_desc_config = NULL;
1261 	WARN_ON(gi->composite.gadget_driver.udc_name);
1262 	mutex_unlock(&gi->lock);
1263 }
1264 
1265 static struct configfs_item_operations os_desc_ops = {
1266 	.allow_link		= os_desc_link,
1267 	.drop_link		= os_desc_unlink,
1268 };
1269 
1270 static const struct config_item_type os_desc_type = {
1271 	.ct_item_ops	= &os_desc_ops,
1272 	.ct_attrs	= os_desc_attrs,
1273 	.ct_owner	= THIS_MODULE,
1274 };
1275 
1276 static inline struct usb_os_desc_ext_prop
1277 *to_usb_os_desc_ext_prop(struct config_item *item)
1278 {
1279 	return container_of(item, struct usb_os_desc_ext_prop, item);
1280 }
1281 
1282 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
1283 {
1284 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
1285 }
1286 
1287 static ssize_t ext_prop_type_store(struct config_item *item,
1288 				   const char *page, size_t len)
1289 {
1290 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1291 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1292 	u8 type;
1293 	int ret;
1294 
1295 	ret = kstrtou8(page, 0, &type);
1296 	if (ret)
1297 		return ret;
1298 
1299 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI)
1300 		return -EINVAL;
1301 
1302 	if (desc->opts_mutex)
1303 		mutex_lock(desc->opts_mutex);
1304 
1305 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
1306 	    ext_prop->type == USB_EXT_PROP_LE32 ||
1307 	    ext_prop->type == USB_EXT_PROP_BE32) &&
1308 	    (type == USB_EXT_PROP_UNICODE ||
1309 	    type == USB_EXT_PROP_UNICODE_ENV ||
1310 	    type == USB_EXT_PROP_UNICODE_LINK))
1311 		ext_prop->data_len <<= 1;
1312 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
1313 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1314 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
1315 		   (type == USB_EXT_PROP_BINARY ||
1316 		   type == USB_EXT_PROP_LE32 ||
1317 		   type == USB_EXT_PROP_BE32))
1318 		ext_prop->data_len >>= 1;
1319 	ext_prop->type = type;
1320 
1321 	if (desc->opts_mutex)
1322 		mutex_unlock(desc->opts_mutex);
1323 	return len;
1324 }
1325 
1326 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
1327 {
1328 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1329 	int len = ext_prop->data_len;
1330 
1331 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1332 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1333 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1334 		len >>= 1;
1335 	memcpy(page, ext_prop->data, len);
1336 
1337 	return len;
1338 }
1339 
1340 static ssize_t ext_prop_data_store(struct config_item *item,
1341 				   const char *page, size_t len)
1342 {
1343 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1344 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1345 	char *new_data;
1346 	size_t ret_len = len;
1347 
1348 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1349 		--len;
1350 	new_data = kmemdup(page, len, GFP_KERNEL);
1351 	if (!new_data)
1352 		return -ENOMEM;
1353 
1354 	if (desc->opts_mutex)
1355 		mutex_lock(desc->opts_mutex);
1356 	kfree(ext_prop->data);
1357 	ext_prop->data = new_data;
1358 	desc->ext_prop_len -= ext_prop->data_len;
1359 	ext_prop->data_len = len;
1360 	desc->ext_prop_len += ext_prop->data_len;
1361 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1362 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1363 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1364 		desc->ext_prop_len -= ext_prop->data_len;
1365 		ext_prop->data_len <<= 1;
1366 		ext_prop->data_len += 2;
1367 		desc->ext_prop_len += ext_prop->data_len;
1368 	}
1369 	if (desc->opts_mutex)
1370 		mutex_unlock(desc->opts_mutex);
1371 	return ret_len;
1372 }
1373 
1374 CONFIGFS_ATTR(ext_prop_, type);
1375 CONFIGFS_ATTR(ext_prop_, data);
1376 
1377 static struct configfs_attribute *ext_prop_attrs[] = {
1378 	&ext_prop_attr_type,
1379 	&ext_prop_attr_data,
1380 	NULL,
1381 };
1382 
1383 static void usb_os_desc_ext_prop_release(struct config_item *item)
1384 {
1385 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1386 
1387 	kfree(ext_prop); /* frees a whole chunk */
1388 }
1389 
1390 static struct configfs_item_operations ext_prop_ops = {
1391 	.release		= usb_os_desc_ext_prop_release,
1392 };
1393 
1394 static struct config_item *ext_prop_make(
1395 		struct config_group *group,
1396 		const char *name)
1397 {
1398 	struct usb_os_desc_ext_prop *ext_prop;
1399 	struct config_item_type *ext_prop_type;
1400 	struct usb_os_desc *desc;
1401 	char *vlabuf;
1402 
1403 	vla_group(data_chunk);
1404 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1405 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1406 
1407 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1408 	if (!vlabuf)
1409 		return ERR_PTR(-ENOMEM);
1410 
1411 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1412 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1413 
1414 	desc = container_of(group, struct usb_os_desc, group);
1415 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1416 	ext_prop_type->ct_attrs = ext_prop_attrs;
1417 	ext_prop_type->ct_owner = desc->owner;
1418 
1419 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1420 
1421 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1422 	if (!ext_prop->name) {
1423 		kfree(vlabuf);
1424 		return ERR_PTR(-ENOMEM);
1425 	}
1426 	desc->ext_prop_len += 14;
1427 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1428 	if (desc->opts_mutex)
1429 		mutex_lock(desc->opts_mutex);
1430 	desc->ext_prop_len += ext_prop->name_len;
1431 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1432 	++desc->ext_prop_count;
1433 	if (desc->opts_mutex)
1434 		mutex_unlock(desc->opts_mutex);
1435 
1436 	return &ext_prop->item;
1437 }
1438 
1439 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1440 {
1441 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1442 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1443 
1444 	if (desc->opts_mutex)
1445 		mutex_lock(desc->opts_mutex);
1446 	list_del(&ext_prop->entry);
1447 	--desc->ext_prop_count;
1448 	kfree(ext_prop->name);
1449 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1450 	if (desc->opts_mutex)
1451 		mutex_unlock(desc->opts_mutex);
1452 	config_item_put(item);
1453 }
1454 
1455 static struct configfs_group_operations interf_grp_ops = {
1456 	.make_item	= &ext_prop_make,
1457 	.drop_item	= &ext_prop_drop,
1458 };
1459 
1460 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1461 					     char *page)
1462 {
1463 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1464 	return 8;
1465 }
1466 
1467 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1468 					      const char *page, size_t len)
1469 {
1470 	struct usb_os_desc *desc = to_usb_os_desc(item);
1471 	int l;
1472 
1473 	l = min_t(int, 8, len);
1474 	if (page[l - 1] == '\n')
1475 		--l;
1476 	if (desc->opts_mutex)
1477 		mutex_lock(desc->opts_mutex);
1478 	memcpy(desc->ext_compat_id, page, l);
1479 
1480 	if (desc->opts_mutex)
1481 		mutex_unlock(desc->opts_mutex);
1482 
1483 	return len;
1484 }
1485 
1486 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1487 						 char *page)
1488 {
1489 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1490 	return 8;
1491 }
1492 
1493 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1494 						  const char *page, size_t len)
1495 {
1496 	struct usb_os_desc *desc = to_usb_os_desc(item);
1497 	int l;
1498 
1499 	l = min_t(int, 8, len);
1500 	if (page[l - 1] == '\n')
1501 		--l;
1502 	if (desc->opts_mutex)
1503 		mutex_lock(desc->opts_mutex);
1504 	memcpy(desc->ext_compat_id + 8, page, l);
1505 
1506 	if (desc->opts_mutex)
1507 		mutex_unlock(desc->opts_mutex);
1508 
1509 	return len;
1510 }
1511 
1512 CONFIGFS_ATTR(interf_grp_, compatible_id);
1513 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1514 
1515 static struct configfs_attribute *interf_grp_attrs[] = {
1516 	&interf_grp_attr_compatible_id,
1517 	&interf_grp_attr_sub_compatible_id,
1518 	NULL
1519 };
1520 
1521 struct config_group *usb_os_desc_prepare_interf_dir(
1522 		struct config_group *parent,
1523 		int n_interf,
1524 		struct usb_os_desc **desc,
1525 		char **names,
1526 		struct module *owner)
1527 {
1528 	struct config_group *os_desc_group;
1529 	struct config_item_type *os_desc_type, *interface_type;
1530 
1531 	vla_group(data_chunk);
1532 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1533 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1534 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1535 
1536 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1537 	if (!vlabuf)
1538 		return ERR_PTR(-ENOMEM);
1539 
1540 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1541 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1542 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1543 
1544 	os_desc_type->ct_owner = owner;
1545 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1546 	configfs_add_default_group(os_desc_group, parent);
1547 
1548 	interface_type->ct_group_ops = &interf_grp_ops;
1549 	interface_type->ct_attrs = interf_grp_attrs;
1550 	interface_type->ct_owner = owner;
1551 
1552 	while (n_interf--) {
1553 		struct usb_os_desc *d;
1554 
1555 		d = desc[n_interf];
1556 		d->owner = owner;
1557 		config_group_init_type_name(&d->group, "", interface_type);
1558 		config_item_set_name(&d->group.cg_item, "interface.%s",
1559 				     names[n_interf]);
1560 		configfs_add_default_group(&d->group, os_desc_group);
1561 	}
1562 
1563 	return os_desc_group;
1564 }
1565 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1566 
1567 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1568 {
1569 	WARN_ON(1);
1570 	return -EINVAL;
1571 }
1572 
1573 int composite_dev_prepare(struct usb_composite_driver *composite,
1574 		struct usb_composite_dev *dev);
1575 
1576 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1577 				  struct usb_ep *ep0);
1578 
1579 static void purge_configs_funcs(struct gadget_info *gi)
1580 {
1581 	struct usb_configuration	*c;
1582 
1583 	list_for_each_entry(c, &gi->cdev.configs, list) {
1584 		struct usb_function *f, *tmp;
1585 		struct config_usb_cfg *cfg;
1586 
1587 		cfg = container_of(c, struct config_usb_cfg, c);
1588 
1589 		list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) {
1590 
1591 			list_move(&f->list, &cfg->func_list);
1592 			if (f->unbind) {
1593 				dev_dbg(&gi->cdev.gadget->dev,
1594 					"unbind function '%s'/%p\n",
1595 					f->name, f);
1596 				f->unbind(c, f);
1597 			}
1598 		}
1599 		c->next_interface_id = 0;
1600 		memset(c->interface, 0, sizeof(c->interface));
1601 		c->superspeed_plus = 0;
1602 		c->superspeed = 0;
1603 		c->highspeed = 0;
1604 		c->fullspeed = 0;
1605 	}
1606 }
1607 
1608 static struct usb_string *
1609 configfs_attach_gadget_strings(struct gadget_info *gi)
1610 {
1611 	struct usb_gadget_strings **gadget_strings;
1612 	struct gadget_language *language;
1613 	struct gadget_string *string;
1614 	unsigned int nlangs = 0;
1615 	struct list_head *iter;
1616 	struct usb_string *us;
1617 	unsigned int i = 0;
1618 	int nstrings = -1;
1619 	unsigned int j;
1620 
1621 	list_for_each(iter, &gi->string_list)
1622 		nlangs++;
1623 
1624 	/* Bail out early if no languages are configured */
1625 	if (!nlangs)
1626 		return NULL;
1627 
1628 	gadget_strings = kcalloc(nlangs + 1, /* including NULL terminator */
1629 				 sizeof(struct usb_gadget_strings *), GFP_KERNEL);
1630 	if (!gadget_strings)
1631 		return ERR_PTR(-ENOMEM);
1632 
1633 	list_for_each_entry(language, &gi->string_list, list) {
1634 		struct usb_string *stringtab;
1635 
1636 		if (nstrings == -1) {
1637 			nstrings = language->nstrings;
1638 		} else if (nstrings != language->nstrings) {
1639 			pr_err("languages must contain the same number of strings\n");
1640 			us = ERR_PTR(-EINVAL);
1641 			goto cleanup;
1642 		}
1643 
1644 		stringtab = kcalloc(language->nstrings + 1, sizeof(struct usb_string),
1645 				    GFP_KERNEL);
1646 		if (!stringtab) {
1647 			us = ERR_PTR(-ENOMEM);
1648 			goto cleanup;
1649 		}
1650 
1651 		stringtab[USB_GADGET_MANUFACTURER_IDX].id = USB_GADGET_MANUFACTURER_IDX;
1652 		stringtab[USB_GADGET_MANUFACTURER_IDX].s = language->manufacturer;
1653 		stringtab[USB_GADGET_PRODUCT_IDX].id = USB_GADGET_PRODUCT_IDX;
1654 		stringtab[USB_GADGET_PRODUCT_IDX].s = language->product;
1655 		stringtab[USB_GADGET_SERIAL_IDX].id = USB_GADGET_SERIAL_IDX;
1656 		stringtab[USB_GADGET_SERIAL_IDX].s = language->serialnumber;
1657 
1658 		j = USB_GADGET_FIRST_AVAIL_IDX;
1659 		list_for_each_entry(string, &language->gadget_strings, list) {
1660 			memcpy(&stringtab[j], &string->usb_string, sizeof(struct usb_string));
1661 			j++;
1662 		}
1663 
1664 		language->stringtab_dev.strings = stringtab;
1665 		gadget_strings[i] = &language->stringtab_dev;
1666 		i++;
1667 	}
1668 
1669 	us = usb_gstrings_attach(&gi->cdev, gadget_strings, nstrings);
1670 
1671 cleanup:
1672 	list_for_each_entry(language, &gi->string_list, list) {
1673 		kfree(language->stringtab_dev.strings);
1674 		language->stringtab_dev.strings = NULL;
1675 	}
1676 
1677 	kfree(gadget_strings);
1678 
1679 	return us;
1680 }
1681 
1682 static int configfs_composite_bind(struct usb_gadget *gadget,
1683 		struct usb_gadget_driver *gdriver)
1684 {
1685 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1686 	struct gadget_info		*gi = container_of(composite,
1687 						struct gadget_info, composite);
1688 	struct usb_composite_dev	*cdev = &gi->cdev;
1689 	struct usb_configuration	*c;
1690 	struct usb_string		*s;
1691 	unsigned			i;
1692 	int				ret;
1693 
1694 	/* the gi->lock is hold by the caller */
1695 	gi->unbind = 0;
1696 	cdev->gadget = gadget;
1697 	set_gadget_data(gadget, cdev);
1698 	ret = composite_dev_prepare(composite, cdev);
1699 	if (ret)
1700 		return ret;
1701 	/* and now the gadget bind */
1702 	ret = -EINVAL;
1703 
1704 	if (list_empty(&gi->cdev.configs)) {
1705 		pr_err("Need at least one configuration in %s.\n",
1706 				gi->composite.name);
1707 		goto err_comp_cleanup;
1708 	}
1709 
1710 
1711 	list_for_each_entry(c, &gi->cdev.configs, list) {
1712 		struct config_usb_cfg *cfg;
1713 
1714 		cfg = container_of(c, struct config_usb_cfg, c);
1715 		if (list_empty(&cfg->func_list)) {
1716 			pr_err("Config %s/%d of %s needs at least one function.\n",
1717 			      c->label, c->bConfigurationValue,
1718 			      gi->composite.name);
1719 			goto err_comp_cleanup;
1720 		}
1721 	}
1722 
1723 	/* init all strings */
1724 	if (!list_empty(&gi->string_list)) {
1725 		s = configfs_attach_gadget_strings(gi);
1726 		if (IS_ERR(s)) {
1727 			ret = PTR_ERR(s);
1728 			goto err_comp_cleanup;
1729 		}
1730 
1731 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1732 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1733 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1734 
1735 		gi->cdev.usb_strings = s;
1736 	}
1737 
1738 	if (gi->use_webusb) {
1739 		cdev->use_webusb = true;
1740 		cdev->bcd_webusb_version = gi->bcd_webusb_version;
1741 		cdev->b_webusb_vendor_code = gi->b_webusb_vendor_code;
1742 		memcpy(cdev->landing_page, gi->landing_page, WEBUSB_URL_RAW_MAX_LENGTH);
1743 	}
1744 
1745 	if (gi->use_os_desc) {
1746 		cdev->use_os_string = true;
1747 		cdev->b_vendor_code = gi->b_vendor_code;
1748 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1749 	}
1750 
1751 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1752 		struct usb_descriptor_header *usb_desc;
1753 
1754 		usb_desc = usb_otg_descriptor_alloc(gadget);
1755 		if (!usb_desc) {
1756 			ret = -ENOMEM;
1757 			goto err_comp_cleanup;
1758 		}
1759 		usb_otg_descriptor_init(gadget, usb_desc);
1760 		otg_desc[0] = usb_desc;
1761 		otg_desc[1] = NULL;
1762 	}
1763 
1764 	/* Go through all configs, attach all functions */
1765 	list_for_each_entry(c, &gi->cdev.configs, list) {
1766 		struct config_usb_cfg *cfg;
1767 		struct usb_function *f;
1768 		struct usb_function *tmp;
1769 		struct gadget_config_name *cn;
1770 
1771 		if (gadget_is_otg(gadget))
1772 			c->descriptors = otg_desc;
1773 
1774 		/* Properly configure the bmAttributes wakeup bit */
1775 		check_remote_wakeup_config(gadget, c);
1776 
1777 		cfg = container_of(c, struct config_usb_cfg, c);
1778 		if (!list_empty(&cfg->string_list)) {
1779 			i = 0;
1780 			list_for_each_entry(cn, &cfg->string_list, list) {
1781 				cfg->gstrings[i] = &cn->stringtab_dev;
1782 				cn->stringtab_dev.strings = &cn->strings;
1783 				cn->strings.s = cn->configuration;
1784 				i++;
1785 			}
1786 			cfg->gstrings[i] = NULL;
1787 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1788 			if (IS_ERR(s)) {
1789 				ret = PTR_ERR(s);
1790 				goto err_comp_cleanup;
1791 			}
1792 			c->iConfiguration = s[0].id;
1793 		}
1794 
1795 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1796 			list_del(&f->list);
1797 			ret = usb_add_function(c, f);
1798 			if (ret) {
1799 				list_add(&f->list, &cfg->func_list);
1800 				goto err_purge_funcs;
1801 			}
1802 		}
1803 		ret = usb_gadget_check_config(cdev->gadget);
1804 		if (ret)
1805 			goto err_purge_funcs;
1806 
1807 		usb_ep_autoconfig_reset(cdev->gadget);
1808 	}
1809 	if (cdev->use_os_string) {
1810 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1811 		if (ret)
1812 			goto err_purge_funcs;
1813 	}
1814 
1815 	usb_ep_autoconfig_reset(cdev->gadget);
1816 	return 0;
1817 
1818 err_purge_funcs:
1819 	purge_configs_funcs(gi);
1820 err_comp_cleanup:
1821 	composite_dev_cleanup(cdev);
1822 	return ret;
1823 }
1824 
1825 static void configfs_composite_unbind(struct usb_gadget *gadget)
1826 {
1827 	struct usb_composite_dev	*cdev;
1828 	struct gadget_info		*gi;
1829 	unsigned long flags;
1830 
1831 	/* the gi->lock is hold by the caller */
1832 
1833 	cdev = get_gadget_data(gadget);
1834 	gi = container_of(cdev, struct gadget_info, cdev);
1835 	spin_lock_irqsave(&gi->spinlock, flags);
1836 	gi->unbind = 1;
1837 	spin_unlock_irqrestore(&gi->spinlock, flags);
1838 
1839 	kfree(otg_desc[0]);
1840 	otg_desc[0] = NULL;
1841 	purge_configs_funcs(gi);
1842 	composite_dev_cleanup(cdev);
1843 	usb_ep_autoconfig_reset(cdev->gadget);
1844 	spin_lock_irqsave(&gi->spinlock, flags);
1845 	cdev->gadget = NULL;
1846 	cdev->deactivations = 0;
1847 	gadget->deactivated = false;
1848 	set_gadget_data(gadget, NULL);
1849 	spin_unlock_irqrestore(&gi->spinlock, flags);
1850 }
1851 
1852 static int configfs_composite_setup(struct usb_gadget *gadget,
1853 		const struct usb_ctrlrequest *ctrl)
1854 {
1855 	struct usb_composite_dev *cdev;
1856 	struct gadget_info *gi;
1857 	unsigned long flags;
1858 	int ret;
1859 
1860 	cdev = get_gadget_data(gadget);
1861 	if (!cdev)
1862 		return 0;
1863 
1864 	gi = container_of(cdev, struct gadget_info, cdev);
1865 	spin_lock_irqsave(&gi->spinlock, flags);
1866 	cdev = get_gadget_data(gadget);
1867 	if (!cdev || gi->unbind) {
1868 		spin_unlock_irqrestore(&gi->spinlock, flags);
1869 		return 0;
1870 	}
1871 
1872 	ret = composite_setup(gadget, ctrl);
1873 	spin_unlock_irqrestore(&gi->spinlock, flags);
1874 	return ret;
1875 }
1876 
1877 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1878 {
1879 	struct usb_composite_dev *cdev;
1880 	struct gadget_info *gi;
1881 	unsigned long flags;
1882 
1883 	cdev = get_gadget_data(gadget);
1884 	if (!cdev)
1885 		return;
1886 
1887 	gi = container_of(cdev, struct gadget_info, cdev);
1888 	spin_lock_irqsave(&gi->spinlock, flags);
1889 	cdev = get_gadget_data(gadget);
1890 	if (!cdev || gi->unbind) {
1891 		spin_unlock_irqrestore(&gi->spinlock, flags);
1892 		return;
1893 	}
1894 
1895 	composite_disconnect(gadget);
1896 	spin_unlock_irqrestore(&gi->spinlock, flags);
1897 }
1898 
1899 static void configfs_composite_reset(struct usb_gadget *gadget)
1900 {
1901 	struct usb_composite_dev *cdev;
1902 	struct gadget_info *gi;
1903 	unsigned long flags;
1904 
1905 	cdev = get_gadget_data(gadget);
1906 	if (!cdev)
1907 		return;
1908 
1909 	gi = container_of(cdev, struct gadget_info, cdev);
1910 	spin_lock_irqsave(&gi->spinlock, flags);
1911 	cdev = get_gadget_data(gadget);
1912 	if (!cdev || gi->unbind) {
1913 		spin_unlock_irqrestore(&gi->spinlock, flags);
1914 		return;
1915 	}
1916 
1917 	composite_reset(gadget);
1918 	spin_unlock_irqrestore(&gi->spinlock, flags);
1919 }
1920 
1921 static void configfs_composite_suspend(struct usb_gadget *gadget)
1922 {
1923 	struct usb_composite_dev *cdev;
1924 	struct gadget_info *gi;
1925 	unsigned long flags;
1926 
1927 	cdev = get_gadget_data(gadget);
1928 	if (!cdev)
1929 		return;
1930 
1931 	gi = container_of(cdev, struct gadget_info, cdev);
1932 	spin_lock_irqsave(&gi->spinlock, flags);
1933 	cdev = get_gadget_data(gadget);
1934 	if (!cdev || gi->unbind) {
1935 		spin_unlock_irqrestore(&gi->spinlock, flags);
1936 		return;
1937 	}
1938 
1939 	composite_suspend(gadget);
1940 	spin_unlock_irqrestore(&gi->spinlock, flags);
1941 }
1942 
1943 static void configfs_composite_resume(struct usb_gadget *gadget)
1944 {
1945 	struct usb_composite_dev *cdev;
1946 	struct gadget_info *gi;
1947 	unsigned long flags;
1948 
1949 	cdev = get_gadget_data(gadget);
1950 	if (!cdev)
1951 		return;
1952 
1953 	gi = container_of(cdev, struct gadget_info, cdev);
1954 	spin_lock_irqsave(&gi->spinlock, flags);
1955 	cdev = get_gadget_data(gadget);
1956 	if (!cdev || gi->unbind) {
1957 		spin_unlock_irqrestore(&gi->spinlock, flags);
1958 		return;
1959 	}
1960 
1961 	composite_resume(gadget);
1962 	spin_unlock_irqrestore(&gi->spinlock, flags);
1963 }
1964 
1965 static const struct usb_gadget_driver configfs_driver_template = {
1966 	.bind           = configfs_composite_bind,
1967 	.unbind         = configfs_composite_unbind,
1968 
1969 	.setup          = configfs_composite_setup,
1970 	.reset          = configfs_composite_reset,
1971 	.disconnect     = configfs_composite_disconnect,
1972 
1973 	.suspend	= configfs_composite_suspend,
1974 	.resume		= configfs_composite_resume,
1975 
1976 	.max_speed	= USB_SPEED_SUPER_PLUS,
1977 	.driver = {
1978 		.owner          = THIS_MODULE,
1979 	},
1980 	.match_existing_only = 1,
1981 };
1982 
1983 static struct config_group *gadgets_make(
1984 		struct config_group *group,
1985 		const char *name)
1986 {
1987 	struct gadget_info *gi;
1988 
1989 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1990 	if (!gi)
1991 		return ERR_PTR(-ENOMEM);
1992 
1993 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1994 
1995 	config_group_init_type_name(&gi->functions_group, "functions",
1996 			&functions_type);
1997 	configfs_add_default_group(&gi->functions_group, &gi->group);
1998 
1999 	config_group_init_type_name(&gi->configs_group, "configs",
2000 			&config_desc_type);
2001 	configfs_add_default_group(&gi->configs_group, &gi->group);
2002 
2003 	config_group_init_type_name(&gi->strings_group, "strings",
2004 			&gadget_language_strings_type);
2005 	configfs_add_default_group(&gi->strings_group, &gi->group);
2006 
2007 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
2008 			&os_desc_type);
2009 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
2010 
2011 	config_group_init_type_name(&gi->webusb_group, "webusb",
2012 			&webusb_type);
2013 	configfs_add_default_group(&gi->webusb_group, &gi->group);
2014 
2015 	gi->composite.bind = configfs_do_nothing;
2016 	gi->composite.unbind = configfs_do_nothing;
2017 	gi->composite.suspend = NULL;
2018 	gi->composite.resume = NULL;
2019 	gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
2020 
2021 	spin_lock_init(&gi->spinlock);
2022 	mutex_init(&gi->lock);
2023 	INIT_LIST_HEAD(&gi->string_list);
2024 	INIT_LIST_HEAD(&gi->available_func);
2025 
2026 	composite_init_dev(&gi->cdev);
2027 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
2028 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
2029 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
2030 
2031 	gi->composite.gadget_driver = configfs_driver_template;
2032 
2033 	gi->composite.gadget_driver.driver.name = kasprintf(GFP_KERNEL,
2034 							    "configfs-gadget.%s", name);
2035 	if (!gi->composite.gadget_driver.driver.name)
2036 		goto err;
2037 
2038 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
2039 	gi->composite.name = gi->composite.gadget_driver.function;
2040 
2041 	if (!gi->composite.gadget_driver.function)
2042 		goto out_free_driver_name;
2043 
2044 	return &gi->group;
2045 
2046 out_free_driver_name:
2047 	kfree(gi->composite.gadget_driver.driver.name);
2048 err:
2049 	kfree(gi);
2050 	return ERR_PTR(-ENOMEM);
2051 }
2052 
2053 static void gadgets_drop(struct config_group *group, struct config_item *item)
2054 {
2055 	config_item_put(item);
2056 }
2057 
2058 static struct configfs_group_operations gadgets_ops = {
2059 	.make_group     = &gadgets_make,
2060 	.drop_item      = &gadgets_drop,
2061 };
2062 
2063 static const struct config_item_type gadgets_type = {
2064 	.ct_group_ops   = &gadgets_ops,
2065 	.ct_owner       = THIS_MODULE,
2066 };
2067 
2068 static struct configfs_subsystem gadget_subsys = {
2069 	.su_group = {
2070 		.cg_item = {
2071 			.ci_namebuf = "usb_gadget",
2072 			.ci_type = &gadgets_type,
2073 		},
2074 	},
2075 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
2076 };
2077 
2078 void unregister_gadget_item(struct config_item *item)
2079 {
2080 	struct gadget_info *gi = to_gadget_info(item);
2081 
2082 	mutex_lock(&gi->lock);
2083 	unregister_gadget(gi);
2084 	mutex_unlock(&gi->lock);
2085 }
2086 EXPORT_SYMBOL_GPL(unregister_gadget_item);
2087 
2088 static int __init gadget_cfs_init(void)
2089 {
2090 	int ret;
2091 
2092 	config_group_init(&gadget_subsys.su_group);
2093 
2094 	ret = configfs_register_subsystem(&gadget_subsys);
2095 	return ret;
2096 }
2097 module_init(gadget_cfs_init);
2098 
2099 static void __exit gadget_cfs_exit(void)
2100 {
2101 	configfs_unregister_subsystem(&gadget_subsys);
2102 }
2103 module_exit(gadget_cfs_exit);
2104