xref: /linux/drivers/usb/gadget/configfs.c (revision 19b3b13c932fc8d613e50e3e92c1944f9fcc02c7) 
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/nls.h>
7 #include <linux/usb/composite.h>
8 #include <linux/usb/gadget_configfs.h>
9 #include "configfs.h"
10 #include "u_f.h"
11 #include "u_os_desc.h"
12 
13 int check_user_usb_string(const char *name,
14 		struct usb_gadget_strings *stringtab_dev)
15 {
16 	u16 num;
17 	int ret;
18 
19 	ret = kstrtou16(name, 0, &num);
20 	if (ret)
21 		return ret;
22 
23 	if (!usb_validate_langid(num))
24 		return -EINVAL;
25 
26 	stringtab_dev->language = num;
27 	return 0;
28 }
29 
30 #define MAX_NAME_LEN	40
31 #define MAX_USB_STRING_LANGS 2
32 
33 static const struct usb_descriptor_header *otg_desc[2];
34 
35 struct gadget_info {
36 	struct config_group group;
37 	struct config_group functions_group;
38 	struct config_group configs_group;
39 	struct config_group strings_group;
40 	struct config_group os_desc_group;
41 
42 	struct mutex lock;
43 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
44 	struct list_head string_list;
45 	struct list_head available_func;
46 
47 	struct usb_composite_driver composite;
48 	struct usb_composite_dev cdev;
49 	bool use_os_desc;
50 	char b_vendor_code;
51 	char qw_sign[OS_STRING_QW_SIGN_LEN];
52 	spinlock_t spinlock;
53 	bool unbind;
54 };
55 
56 static inline struct gadget_info *to_gadget_info(struct config_item *item)
57 {
58 	return container_of(to_config_group(item), struct gadget_info, group);
59 }
60 
61 struct config_usb_cfg {
62 	struct config_group group;
63 	struct config_group strings_group;
64 	struct list_head string_list;
65 	struct usb_configuration c;
66 	struct list_head func_list;
67 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
68 };
69 
70 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
71 {
72 	return container_of(to_config_group(item), struct config_usb_cfg,
73 			group);
74 }
75 
76 static inline struct gadget_info *cfg_to_gadget_info(struct config_usb_cfg *cfg)
77 {
78 	return container_of(cfg->c.cdev, struct gadget_info, cdev);
79 }
80 
81 struct gadget_strings {
82 	struct usb_gadget_strings stringtab_dev;
83 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
84 	char *manufacturer;
85 	char *product;
86 	char *serialnumber;
87 
88 	struct config_group group;
89 	struct list_head list;
90 };
91 
92 struct gadget_config_name {
93 	struct usb_gadget_strings stringtab_dev;
94 	struct usb_string strings;
95 	char *configuration;
96 
97 	struct config_group group;
98 	struct list_head list;
99 };
100 
101 #define USB_MAX_STRING_WITH_NULL_LEN	(USB_MAX_STRING_LEN+1)
102 
103 static int usb_string_copy(const char *s, char **s_copy)
104 {
105 	int ret;
106 	char *str;
107 	char *copy = *s_copy;
108 	ret = strlen(s);
109 	if (ret > USB_MAX_STRING_LEN)
110 		return -EOVERFLOW;
111 
112 	if (copy) {
113 		str = copy;
114 	} else {
115 		str = kmalloc(USB_MAX_STRING_WITH_NULL_LEN, GFP_KERNEL);
116 		if (!str)
117 			return -ENOMEM;
118 	}
119 	strcpy(str, s);
120 	if (str[ret - 1] == '\n')
121 		str[ret - 1] = '\0';
122 	*s_copy = str;
123 	return 0;
124 }
125 
126 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
127 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
128 			char *page)	\
129 {	\
130 	return sprintf(page, "0x%02x\n", \
131 		to_gadget_info(item)->cdev.desc.__name); \
132 }
133 
134 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
135 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
136 			char *page)	\
137 {	\
138 	return sprintf(page, "0x%04x\n", \
139 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
140 }
141 
142 
143 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
144 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
145 		const char *page, size_t len)		\
146 {							\
147 	u8 val;						\
148 	int ret;					\
149 	ret = kstrtou8(page, 0, &val);			\
150 	if (ret)					\
151 		return ret;				\
152 	to_gadget_info(item)->cdev.desc._name = val;	\
153 	return len;					\
154 }
155 
156 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
157 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
158 		const char *page, size_t len)		\
159 {							\
160 	u16 val;					\
161 	int ret;					\
162 	ret = kstrtou16(page, 0, &val);			\
163 	if (ret)					\
164 		return ret;				\
165 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
166 	return len;					\
167 }
168 
169 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
170 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
171 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
172 
173 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
174 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
175 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
176 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
177 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
178 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
179 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
180 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
181 
182 static ssize_t is_valid_bcd(u16 bcd_val)
183 {
184 	if ((bcd_val & 0xf) > 9)
185 		return -EINVAL;
186 	if (((bcd_val >> 4) & 0xf) > 9)
187 		return -EINVAL;
188 	if (((bcd_val >> 8) & 0xf) > 9)
189 		return -EINVAL;
190 	if (((bcd_val >> 12) & 0xf) > 9)
191 		return -EINVAL;
192 	return 0;
193 }
194 
195 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
196 		const char *page, size_t len)
197 {
198 	u16 bcdDevice;
199 	int ret;
200 
201 	ret = kstrtou16(page, 0, &bcdDevice);
202 	if (ret)
203 		return ret;
204 	ret = is_valid_bcd(bcdDevice);
205 	if (ret)
206 		return ret;
207 
208 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
209 	return len;
210 }
211 
212 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
213 		const char *page, size_t len)
214 {
215 	u16 bcdUSB;
216 	int ret;
217 
218 	ret = kstrtou16(page, 0, &bcdUSB);
219 	if (ret)
220 		return ret;
221 	ret = is_valid_bcd(bcdUSB);
222 	if (ret)
223 		return ret;
224 
225 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
226 	return len;
227 }
228 
229 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
230 {
231 	struct gadget_info *gi = to_gadget_info(item);
232 	char *udc_name;
233 	int ret;
234 
235 	mutex_lock(&gi->lock);
236 	udc_name = gi->composite.gadget_driver.udc_name;
237 	ret = sprintf(page, "%s\n", udc_name ?: "");
238 	mutex_unlock(&gi->lock);
239 
240 	return ret;
241 }
242 
243 static int unregister_gadget(struct gadget_info *gi)
244 {
245 	int ret;
246 
247 	if (!gi->composite.gadget_driver.udc_name)
248 		return -ENODEV;
249 
250 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
251 	if (ret)
252 		return ret;
253 	kfree(gi->composite.gadget_driver.udc_name);
254 	gi->composite.gadget_driver.udc_name = NULL;
255 	return 0;
256 }
257 
258 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
259 		const char *page, size_t len)
260 {
261 	struct gadget_info *gi = to_gadget_info(item);
262 	char *name;
263 	int ret;
264 
265 	if (strlen(page) < len)
266 		return -EOVERFLOW;
267 
268 	name = kstrdup(page, GFP_KERNEL);
269 	if (!name)
270 		return -ENOMEM;
271 	if (name[len - 1] == '\n')
272 		name[len - 1] = '\0';
273 
274 	mutex_lock(&gi->lock);
275 
276 	if (!strlen(name)) {
277 		ret = unregister_gadget(gi);
278 		if (ret)
279 			goto err;
280 		kfree(name);
281 	} else {
282 		if (gi->composite.gadget_driver.udc_name) {
283 			ret = -EBUSY;
284 			goto err;
285 		}
286 		gi->composite.gadget_driver.udc_name = name;
287 		ret = usb_gadget_register_driver(&gi->composite.gadget_driver);
288 		if (ret) {
289 			gi->composite.gadget_driver.udc_name = NULL;
290 			goto err;
291 		}
292 	}
293 	mutex_unlock(&gi->lock);
294 	return len;
295 err:
296 	kfree(name);
297 	mutex_unlock(&gi->lock);
298 	return ret;
299 }
300 
301 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
302 					      char *page)
303 {
304 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
305 
306 	return sprintf(page, "%s\n", usb_speed_string(speed));
307 }
308 
309 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
310 					       const char *page, size_t len)
311 {
312 	struct gadget_info *gi = to_gadget_info(item);
313 
314 	mutex_lock(&gi->lock);
315 
316 	/* Prevent changing of max_speed after the driver is binded */
317 	if (gi->composite.gadget_driver.udc_name)
318 		goto err;
319 
320 	if (strncmp(page, "super-speed-plus", 16) == 0)
321 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
322 	else if (strncmp(page, "super-speed", 11) == 0)
323 		gi->composite.max_speed = USB_SPEED_SUPER;
324 	else if (strncmp(page, "high-speed", 10) == 0)
325 		gi->composite.max_speed = USB_SPEED_HIGH;
326 	else if (strncmp(page, "full-speed", 10) == 0)
327 		gi->composite.max_speed = USB_SPEED_FULL;
328 	else if (strncmp(page, "low-speed", 9) == 0)
329 		gi->composite.max_speed = USB_SPEED_LOW;
330 	else
331 		goto err;
332 
333 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
334 
335 	mutex_unlock(&gi->lock);
336 	return len;
337 err:
338 	mutex_unlock(&gi->lock);
339 	return -EINVAL;
340 }
341 
342 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
343 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
344 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
345 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
346 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
347 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
348 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
349 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
350 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
351 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
352 
353 static struct configfs_attribute *gadget_root_attrs[] = {
354 	&gadget_dev_desc_attr_bDeviceClass,
355 	&gadget_dev_desc_attr_bDeviceSubClass,
356 	&gadget_dev_desc_attr_bDeviceProtocol,
357 	&gadget_dev_desc_attr_bMaxPacketSize0,
358 	&gadget_dev_desc_attr_idVendor,
359 	&gadget_dev_desc_attr_idProduct,
360 	&gadget_dev_desc_attr_bcdDevice,
361 	&gadget_dev_desc_attr_bcdUSB,
362 	&gadget_dev_desc_attr_UDC,
363 	&gadget_dev_desc_attr_max_speed,
364 	NULL,
365 };
366 
367 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
368 {
369 	return container_of(to_config_group(item), struct gadget_strings,
370 			 group);
371 }
372 
373 static inline struct gadget_config_name *to_gadget_config_name(
374 		struct config_item *item)
375 {
376 	return container_of(to_config_group(item), struct gadget_config_name,
377 			 group);
378 }
379 
380 static inline struct usb_function_instance *to_usb_function_instance(
381 		struct config_item *item)
382 {
383 	return container_of(to_config_group(item),
384 			 struct usb_function_instance, group);
385 }
386 
387 static void gadget_info_attr_release(struct config_item *item)
388 {
389 	struct gadget_info *gi = to_gadget_info(item);
390 
391 	WARN_ON(!list_empty(&gi->cdev.configs));
392 	WARN_ON(!list_empty(&gi->string_list));
393 	WARN_ON(!list_empty(&gi->available_func));
394 	kfree(gi->composite.gadget_driver.function);
395 	kfree(gi);
396 }
397 
398 static struct configfs_item_operations gadget_root_item_ops = {
399 	.release                = gadget_info_attr_release,
400 };
401 
402 static void gadget_config_attr_release(struct config_item *item)
403 {
404 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
405 
406 	WARN_ON(!list_empty(&cfg->c.functions));
407 	list_del(&cfg->c.list);
408 	kfree(cfg->c.label);
409 	kfree(cfg);
410 }
411 
412 static int config_usb_cfg_link(
413 	struct config_item *usb_cfg_ci,
414 	struct config_item *usb_func_ci)
415 {
416 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
417 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
418 
419 	struct usb_function_instance *fi =
420 			to_usb_function_instance(usb_func_ci);
421 	struct usb_function_instance *a_fi = NULL, *iter;
422 	struct usb_function *f;
423 	int ret;
424 
425 	mutex_lock(&gi->lock);
426 	/*
427 	 * Make sure this function is from within our _this_ gadget and not
428 	 * from another gadget or a random directory.
429 	 * Also a function instance can only be linked once.
430 	 */
431 	list_for_each_entry(iter, &gi->available_func, cfs_list) {
432 		if (iter != fi)
433 			continue;
434 		a_fi = iter;
435 		break;
436 	}
437 	if (!a_fi) {
438 		ret = -EINVAL;
439 		goto out;
440 	}
441 
442 	list_for_each_entry(f, &cfg->func_list, list) {
443 		if (f->fi == fi) {
444 			ret = -EEXIST;
445 			goto out;
446 		}
447 	}
448 
449 	f = usb_get_function(fi);
450 	if (IS_ERR(f)) {
451 		ret = PTR_ERR(f);
452 		goto out;
453 	}
454 
455 	/* stash the function until we bind it to the gadget */
456 	list_add_tail(&f->list, &cfg->func_list);
457 	ret = 0;
458 out:
459 	mutex_unlock(&gi->lock);
460 	return ret;
461 }
462 
463 static void config_usb_cfg_unlink(
464 	struct config_item *usb_cfg_ci,
465 	struct config_item *usb_func_ci)
466 {
467 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
468 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
469 
470 	struct usb_function_instance *fi =
471 			to_usb_function_instance(usb_func_ci);
472 	struct usb_function *f;
473 
474 	/*
475 	 * ideally I would like to forbid to unlink functions while a gadget is
476 	 * bound to an UDC. Since this isn't possible at the moment, we simply
477 	 * force an unbind, the function is available here and then we can
478 	 * remove the function.
479 	 */
480 	mutex_lock(&gi->lock);
481 	if (gi->composite.gadget_driver.udc_name)
482 		unregister_gadget(gi);
483 	WARN_ON(gi->composite.gadget_driver.udc_name);
484 
485 	list_for_each_entry(f, &cfg->func_list, list) {
486 		if (f->fi == fi) {
487 			list_del(&f->list);
488 			usb_put_function(f);
489 			mutex_unlock(&gi->lock);
490 			return;
491 		}
492 	}
493 	mutex_unlock(&gi->lock);
494 	WARN(1, "Unable to locate function to unbind\n");
495 }
496 
497 static struct configfs_item_operations gadget_config_item_ops = {
498 	.release                = gadget_config_attr_release,
499 	.allow_link             = config_usb_cfg_link,
500 	.drop_link              = config_usb_cfg_unlink,
501 };
502 
503 
504 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
505 		char *page)
506 {
507 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
508 
509 	return sprintf(page, "%u\n", cfg->c.MaxPower);
510 }
511 
512 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
513 		const char *page, size_t len)
514 {
515 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
516 	u16 val;
517 	int ret;
518 	ret = kstrtou16(page, 0, &val);
519 	if (ret)
520 		return ret;
521 	if (DIV_ROUND_UP(val, 8) > 0xff)
522 		return -ERANGE;
523 	cfg->c.MaxPower = val;
524 	return len;
525 }
526 
527 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
528 		char *page)
529 {
530 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
531 
532 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
533 }
534 
535 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
536 		const char *page, size_t len)
537 {
538 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
539 	u8 val;
540 	int ret;
541 	ret = kstrtou8(page, 0, &val);
542 	if (ret)
543 		return ret;
544 	if (!(val & USB_CONFIG_ATT_ONE))
545 		return -EINVAL;
546 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
547 				USB_CONFIG_ATT_WAKEUP))
548 		return -EINVAL;
549 	cfg->c.bmAttributes = val;
550 	return len;
551 }
552 
553 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
554 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
555 
556 static struct configfs_attribute *gadget_config_attrs[] = {
557 	&gadget_config_desc_attr_MaxPower,
558 	&gadget_config_desc_attr_bmAttributes,
559 	NULL,
560 };
561 
562 static const struct config_item_type gadget_config_type = {
563 	.ct_item_ops	= &gadget_config_item_ops,
564 	.ct_attrs	= gadget_config_attrs,
565 	.ct_owner	= THIS_MODULE,
566 };
567 
568 static const struct config_item_type gadget_root_type = {
569 	.ct_item_ops	= &gadget_root_item_ops,
570 	.ct_attrs	= gadget_root_attrs,
571 	.ct_owner	= THIS_MODULE,
572 };
573 
574 static void composite_init_dev(struct usb_composite_dev *cdev)
575 {
576 	spin_lock_init(&cdev->lock);
577 	INIT_LIST_HEAD(&cdev->configs);
578 	INIT_LIST_HEAD(&cdev->gstrings);
579 }
580 
581 static struct config_group *function_make(
582 		struct config_group *group,
583 		const char *name)
584 {
585 	struct gadget_info *gi;
586 	struct usb_function_instance *fi;
587 	char buf[MAX_NAME_LEN];
588 	char *func_name;
589 	char *instance_name;
590 	int ret;
591 
592 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
593 	if (ret >= MAX_NAME_LEN)
594 		return ERR_PTR(-ENAMETOOLONG);
595 
596 	func_name = buf;
597 	instance_name = strchr(func_name, '.');
598 	if (!instance_name) {
599 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
600 		return ERR_PTR(-EINVAL);
601 	}
602 	*instance_name = '\0';
603 	instance_name++;
604 
605 	fi = usb_get_function_instance(func_name);
606 	if (IS_ERR(fi))
607 		return ERR_CAST(fi);
608 
609 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
610 	if (ret) {
611 		usb_put_function_instance(fi);
612 		return ERR_PTR(ret);
613 	}
614 	if (fi->set_inst_name) {
615 		ret = fi->set_inst_name(fi, instance_name);
616 		if (ret) {
617 			usb_put_function_instance(fi);
618 			return ERR_PTR(ret);
619 		}
620 	}
621 
622 	gi = container_of(group, struct gadget_info, functions_group);
623 
624 	mutex_lock(&gi->lock);
625 	list_add_tail(&fi->cfs_list, &gi->available_func);
626 	mutex_unlock(&gi->lock);
627 	return &fi->group;
628 }
629 
630 static void function_drop(
631 		struct config_group *group,
632 		struct config_item *item)
633 {
634 	struct usb_function_instance *fi = to_usb_function_instance(item);
635 	struct gadget_info *gi;
636 
637 	gi = container_of(group, struct gadget_info, functions_group);
638 
639 	mutex_lock(&gi->lock);
640 	list_del(&fi->cfs_list);
641 	mutex_unlock(&gi->lock);
642 	config_item_put(item);
643 }
644 
645 static struct configfs_group_operations functions_ops = {
646 	.make_group     = &function_make,
647 	.drop_item      = &function_drop,
648 };
649 
650 static const struct config_item_type functions_type = {
651 	.ct_group_ops   = &functions_ops,
652 	.ct_owner       = THIS_MODULE,
653 };
654 
655 GS_STRINGS_RW(gadget_config_name, configuration);
656 
657 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
658 	&gadget_config_name_attr_configuration,
659 	NULL,
660 };
661 
662 static void gadget_config_name_attr_release(struct config_item *item)
663 {
664 	struct gadget_config_name *cn = to_gadget_config_name(item);
665 
666 	kfree(cn->configuration);
667 
668 	list_del(&cn->list);
669 	kfree(cn);
670 }
671 
672 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
673 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
674 
675 static struct config_group *config_desc_make(
676 		struct config_group *group,
677 		const char *name)
678 {
679 	struct gadget_info *gi;
680 	struct config_usb_cfg *cfg;
681 	char buf[MAX_NAME_LEN];
682 	char *num_str;
683 	u8 num;
684 	int ret;
685 
686 	gi = container_of(group, struct gadget_info, configs_group);
687 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
688 	if (ret >= MAX_NAME_LEN)
689 		return ERR_PTR(-ENAMETOOLONG);
690 
691 	num_str = strchr(buf, '.');
692 	if (!num_str) {
693 		pr_err("Unable to locate . in name.bConfigurationValue\n");
694 		return ERR_PTR(-EINVAL);
695 	}
696 
697 	*num_str = '\0';
698 	num_str++;
699 
700 	if (!strlen(buf))
701 		return ERR_PTR(-EINVAL);
702 
703 	ret = kstrtou8(num_str, 0, &num);
704 	if (ret)
705 		return ERR_PTR(ret);
706 
707 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
708 	if (!cfg)
709 		return ERR_PTR(-ENOMEM);
710 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
711 	if (!cfg->c.label) {
712 		ret = -ENOMEM;
713 		goto err;
714 	}
715 	cfg->c.bConfigurationValue = num;
716 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
717 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
718 	INIT_LIST_HEAD(&cfg->string_list);
719 	INIT_LIST_HEAD(&cfg->func_list);
720 
721 	config_group_init_type_name(&cfg->group, name,
722 				&gadget_config_type);
723 
724 	config_group_init_type_name(&cfg->strings_group, "strings",
725 			&gadget_config_name_strings_type);
726 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
727 
728 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
729 	if (ret)
730 		goto err;
731 
732 	return &cfg->group;
733 err:
734 	kfree(cfg->c.label);
735 	kfree(cfg);
736 	return ERR_PTR(ret);
737 }
738 
739 static void config_desc_drop(
740 		struct config_group *group,
741 		struct config_item *item)
742 {
743 	config_item_put(item);
744 }
745 
746 static struct configfs_group_operations config_desc_ops = {
747 	.make_group     = &config_desc_make,
748 	.drop_item      = &config_desc_drop,
749 };
750 
751 static const struct config_item_type config_desc_type = {
752 	.ct_group_ops   = &config_desc_ops,
753 	.ct_owner       = THIS_MODULE,
754 };
755 
756 GS_STRINGS_RW(gadget_strings, manufacturer);
757 GS_STRINGS_RW(gadget_strings, product);
758 GS_STRINGS_RW(gadget_strings, serialnumber);
759 
760 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
761 	&gadget_strings_attr_manufacturer,
762 	&gadget_strings_attr_product,
763 	&gadget_strings_attr_serialnumber,
764 	NULL,
765 };
766 
767 static void gadget_strings_attr_release(struct config_item *item)
768 {
769 	struct gadget_strings *gs = to_gadget_strings(item);
770 
771 	kfree(gs->manufacturer);
772 	kfree(gs->product);
773 	kfree(gs->serialnumber);
774 
775 	list_del(&gs->list);
776 	kfree(gs);
777 }
778 
779 USB_CONFIG_STRING_RW_OPS(gadget_strings);
780 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
781 
782 static inline struct gadget_info *os_desc_item_to_gadget_info(
783 		struct config_item *item)
784 {
785 	return container_of(to_config_group(item),
786 			struct gadget_info, os_desc_group);
787 }
788 
789 static ssize_t os_desc_use_show(struct config_item *item, char *page)
790 {
791 	return sprintf(page, "%d\n",
792 			os_desc_item_to_gadget_info(item)->use_os_desc);
793 }
794 
795 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
796 				 size_t len)
797 {
798 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
799 	int ret;
800 	bool use;
801 
802 	mutex_lock(&gi->lock);
803 	ret = strtobool(page, &use);
804 	if (!ret) {
805 		gi->use_os_desc = use;
806 		ret = len;
807 	}
808 	mutex_unlock(&gi->lock);
809 
810 	return ret;
811 }
812 
813 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
814 {
815 	return sprintf(page, "0x%02x\n",
816 			os_desc_item_to_gadget_info(item)->b_vendor_code);
817 }
818 
819 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
820 					   const char *page, size_t len)
821 {
822 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
823 	int ret;
824 	u8 b_vendor_code;
825 
826 	mutex_lock(&gi->lock);
827 	ret = kstrtou8(page, 0, &b_vendor_code);
828 	if (!ret) {
829 		gi->b_vendor_code = b_vendor_code;
830 		ret = len;
831 	}
832 	mutex_unlock(&gi->lock);
833 
834 	return ret;
835 }
836 
837 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
838 {
839 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
840 	int res;
841 
842 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
843 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
844 	page[res++] = '\n';
845 
846 	return res;
847 }
848 
849 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
850 				     size_t len)
851 {
852 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
853 	int res, l;
854 
855 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
856 	if (page[l - 1] == '\n')
857 		--l;
858 
859 	mutex_lock(&gi->lock);
860 	res = utf8s_to_utf16s(page, l,
861 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
862 			      OS_STRING_QW_SIGN_LEN);
863 	if (res > 0)
864 		res = len;
865 	mutex_unlock(&gi->lock);
866 
867 	return res;
868 }
869 
870 CONFIGFS_ATTR(os_desc_, use);
871 CONFIGFS_ATTR(os_desc_, b_vendor_code);
872 CONFIGFS_ATTR(os_desc_, qw_sign);
873 
874 static struct configfs_attribute *os_desc_attrs[] = {
875 	&os_desc_attr_use,
876 	&os_desc_attr_b_vendor_code,
877 	&os_desc_attr_qw_sign,
878 	NULL,
879 };
880 
881 static int os_desc_link(struct config_item *os_desc_ci,
882 			struct config_item *usb_cfg_ci)
883 {
884 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
885 	struct usb_composite_dev *cdev = &gi->cdev;
886 	struct config_usb_cfg *c_target = to_config_usb_cfg(usb_cfg_ci);
887 	struct usb_configuration *c = NULL, *iter;
888 	int ret;
889 
890 	mutex_lock(&gi->lock);
891 	list_for_each_entry(iter, &cdev->configs, list) {
892 		if (iter != &c_target->c)
893 			continue;
894 		c = iter;
895 		break;
896 	}
897 	if (!c) {
898 		ret = -EINVAL;
899 		goto out;
900 	}
901 
902 	if (cdev->os_desc_config) {
903 		ret = -EBUSY;
904 		goto out;
905 	}
906 
907 	cdev->os_desc_config = &c_target->c;
908 	ret = 0;
909 
910 out:
911 	mutex_unlock(&gi->lock);
912 	return ret;
913 }
914 
915 static void os_desc_unlink(struct config_item *os_desc_ci,
916 			  struct config_item *usb_cfg_ci)
917 {
918 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
919 	struct usb_composite_dev *cdev = &gi->cdev;
920 
921 	mutex_lock(&gi->lock);
922 	if (gi->composite.gadget_driver.udc_name)
923 		unregister_gadget(gi);
924 	cdev->os_desc_config = NULL;
925 	WARN_ON(gi->composite.gadget_driver.udc_name);
926 	mutex_unlock(&gi->lock);
927 }
928 
929 static struct configfs_item_operations os_desc_ops = {
930 	.allow_link		= os_desc_link,
931 	.drop_link		= os_desc_unlink,
932 };
933 
934 static struct config_item_type os_desc_type = {
935 	.ct_item_ops	= &os_desc_ops,
936 	.ct_attrs	= os_desc_attrs,
937 	.ct_owner	= THIS_MODULE,
938 };
939 
940 static inline struct usb_os_desc_ext_prop
941 *to_usb_os_desc_ext_prop(struct config_item *item)
942 {
943 	return container_of(item, struct usb_os_desc_ext_prop, item);
944 }
945 
946 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
947 {
948 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
949 }
950 
951 static ssize_t ext_prop_type_store(struct config_item *item,
952 				   const char *page, size_t len)
953 {
954 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
955 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
956 	u8 type;
957 	int ret;
958 
959 	if (desc->opts_mutex)
960 		mutex_lock(desc->opts_mutex);
961 	ret = kstrtou8(page, 0, &type);
962 	if (ret)
963 		goto end;
964 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
965 		ret = -EINVAL;
966 		goto end;
967 	}
968 
969 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
970 	    ext_prop->type == USB_EXT_PROP_LE32 ||
971 	    ext_prop->type == USB_EXT_PROP_BE32) &&
972 	    (type == USB_EXT_PROP_UNICODE ||
973 	    type == USB_EXT_PROP_UNICODE_ENV ||
974 	    type == USB_EXT_PROP_UNICODE_LINK))
975 		ext_prop->data_len <<= 1;
976 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
977 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
978 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
979 		   (type == USB_EXT_PROP_BINARY ||
980 		   type == USB_EXT_PROP_LE32 ||
981 		   type == USB_EXT_PROP_BE32))
982 		ext_prop->data_len >>= 1;
983 	ext_prop->type = type;
984 	ret = len;
985 
986 end:
987 	if (desc->opts_mutex)
988 		mutex_unlock(desc->opts_mutex);
989 	return ret;
990 }
991 
992 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
993 {
994 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
995 	int len = ext_prop->data_len;
996 
997 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
998 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
999 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1000 		len >>= 1;
1001 	memcpy(page, ext_prop->data, len);
1002 
1003 	return len;
1004 }
1005 
1006 static ssize_t ext_prop_data_store(struct config_item *item,
1007 				   const char *page, size_t len)
1008 {
1009 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1010 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1011 	char *new_data;
1012 	size_t ret_len = len;
1013 
1014 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1015 		--len;
1016 	new_data = kmemdup(page, len, GFP_KERNEL);
1017 	if (!new_data)
1018 		return -ENOMEM;
1019 
1020 	if (desc->opts_mutex)
1021 		mutex_lock(desc->opts_mutex);
1022 	kfree(ext_prop->data);
1023 	ext_prop->data = new_data;
1024 	desc->ext_prop_len -= ext_prop->data_len;
1025 	ext_prop->data_len = len;
1026 	desc->ext_prop_len += ext_prop->data_len;
1027 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1028 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1029 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1030 		desc->ext_prop_len -= ext_prop->data_len;
1031 		ext_prop->data_len <<= 1;
1032 		ext_prop->data_len += 2;
1033 		desc->ext_prop_len += ext_prop->data_len;
1034 	}
1035 	if (desc->opts_mutex)
1036 		mutex_unlock(desc->opts_mutex);
1037 	return ret_len;
1038 }
1039 
1040 CONFIGFS_ATTR(ext_prop_, type);
1041 CONFIGFS_ATTR(ext_prop_, data);
1042 
1043 static struct configfs_attribute *ext_prop_attrs[] = {
1044 	&ext_prop_attr_type,
1045 	&ext_prop_attr_data,
1046 	NULL,
1047 };
1048 
1049 static void usb_os_desc_ext_prop_release(struct config_item *item)
1050 {
1051 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1052 
1053 	kfree(ext_prop); /* frees a whole chunk */
1054 }
1055 
1056 static struct configfs_item_operations ext_prop_ops = {
1057 	.release		= usb_os_desc_ext_prop_release,
1058 };
1059 
1060 static struct config_item *ext_prop_make(
1061 		struct config_group *group,
1062 		const char *name)
1063 {
1064 	struct usb_os_desc_ext_prop *ext_prop;
1065 	struct config_item_type *ext_prop_type;
1066 	struct usb_os_desc *desc;
1067 	char *vlabuf;
1068 
1069 	vla_group(data_chunk);
1070 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1071 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1072 
1073 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1074 	if (!vlabuf)
1075 		return ERR_PTR(-ENOMEM);
1076 
1077 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1078 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1079 
1080 	desc = container_of(group, struct usb_os_desc, group);
1081 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1082 	ext_prop_type->ct_attrs = ext_prop_attrs;
1083 	ext_prop_type->ct_owner = desc->owner;
1084 
1085 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1086 
1087 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1088 	if (!ext_prop->name) {
1089 		kfree(vlabuf);
1090 		return ERR_PTR(-ENOMEM);
1091 	}
1092 	desc->ext_prop_len += 14;
1093 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1094 	if (desc->opts_mutex)
1095 		mutex_lock(desc->opts_mutex);
1096 	desc->ext_prop_len += ext_prop->name_len;
1097 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1098 	++desc->ext_prop_count;
1099 	if (desc->opts_mutex)
1100 		mutex_unlock(desc->opts_mutex);
1101 
1102 	return &ext_prop->item;
1103 }
1104 
1105 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1106 {
1107 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1108 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1109 
1110 	if (desc->opts_mutex)
1111 		mutex_lock(desc->opts_mutex);
1112 	list_del(&ext_prop->entry);
1113 	--desc->ext_prop_count;
1114 	kfree(ext_prop->name);
1115 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1116 	if (desc->opts_mutex)
1117 		mutex_unlock(desc->opts_mutex);
1118 	config_item_put(item);
1119 }
1120 
1121 static struct configfs_group_operations interf_grp_ops = {
1122 	.make_item	= &ext_prop_make,
1123 	.drop_item	= &ext_prop_drop,
1124 };
1125 
1126 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1127 					     char *page)
1128 {
1129 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1130 	return 8;
1131 }
1132 
1133 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1134 					      const char *page, size_t len)
1135 {
1136 	struct usb_os_desc *desc = to_usb_os_desc(item);
1137 	int l;
1138 
1139 	l = min_t(int, 8, len);
1140 	if (page[l - 1] == '\n')
1141 		--l;
1142 	if (desc->opts_mutex)
1143 		mutex_lock(desc->opts_mutex);
1144 	memcpy(desc->ext_compat_id, page, l);
1145 
1146 	if (desc->opts_mutex)
1147 		mutex_unlock(desc->opts_mutex);
1148 
1149 	return len;
1150 }
1151 
1152 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1153 						 char *page)
1154 {
1155 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1156 	return 8;
1157 }
1158 
1159 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1160 						  const char *page, size_t len)
1161 {
1162 	struct usb_os_desc *desc = to_usb_os_desc(item);
1163 	int l;
1164 
1165 	l = min_t(int, 8, len);
1166 	if (page[l - 1] == '\n')
1167 		--l;
1168 	if (desc->opts_mutex)
1169 		mutex_lock(desc->opts_mutex);
1170 	memcpy(desc->ext_compat_id + 8, page, l);
1171 
1172 	if (desc->opts_mutex)
1173 		mutex_unlock(desc->opts_mutex);
1174 
1175 	return len;
1176 }
1177 
1178 CONFIGFS_ATTR(interf_grp_, compatible_id);
1179 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1180 
1181 static struct configfs_attribute *interf_grp_attrs[] = {
1182 	&interf_grp_attr_compatible_id,
1183 	&interf_grp_attr_sub_compatible_id,
1184 	NULL
1185 };
1186 
1187 struct config_group *usb_os_desc_prepare_interf_dir(
1188 		struct config_group *parent,
1189 		int n_interf,
1190 		struct usb_os_desc **desc,
1191 		char **names,
1192 		struct module *owner)
1193 {
1194 	struct config_group *os_desc_group;
1195 	struct config_item_type *os_desc_type, *interface_type;
1196 
1197 	vla_group(data_chunk);
1198 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1199 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1200 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1201 
1202 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1203 	if (!vlabuf)
1204 		return ERR_PTR(-ENOMEM);
1205 
1206 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1207 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1208 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1209 
1210 	os_desc_type->ct_owner = owner;
1211 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1212 	configfs_add_default_group(os_desc_group, parent);
1213 
1214 	interface_type->ct_group_ops = &interf_grp_ops;
1215 	interface_type->ct_attrs = interf_grp_attrs;
1216 	interface_type->ct_owner = owner;
1217 
1218 	while (n_interf--) {
1219 		struct usb_os_desc *d;
1220 
1221 		d = desc[n_interf];
1222 		d->owner = owner;
1223 		config_group_init_type_name(&d->group, "", interface_type);
1224 		config_item_set_name(&d->group.cg_item, "interface.%s",
1225 				     names[n_interf]);
1226 		configfs_add_default_group(&d->group, os_desc_group);
1227 	}
1228 
1229 	return os_desc_group;
1230 }
1231 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1232 
1233 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1234 {
1235 	WARN_ON(1);
1236 	return -EINVAL;
1237 }
1238 
1239 int composite_dev_prepare(struct usb_composite_driver *composite,
1240 		struct usb_composite_dev *dev);
1241 
1242 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1243 				  struct usb_ep *ep0);
1244 
1245 static void purge_configs_funcs(struct gadget_info *gi)
1246 {
1247 	struct usb_configuration	*c;
1248 
1249 	list_for_each_entry(c, &gi->cdev.configs, list) {
1250 		struct usb_function *f, *tmp;
1251 		struct config_usb_cfg *cfg;
1252 
1253 		cfg = container_of(c, struct config_usb_cfg, c);
1254 
1255 		list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) {
1256 
1257 			list_move(&f->list, &cfg->func_list);
1258 			if (f->unbind) {
1259 				dev_dbg(&gi->cdev.gadget->dev,
1260 					"unbind function '%s'/%p\n",
1261 					f->name, f);
1262 				f->unbind(c, f);
1263 			}
1264 		}
1265 		c->next_interface_id = 0;
1266 		memset(c->interface, 0, sizeof(c->interface));
1267 		c->superspeed_plus = 0;
1268 		c->superspeed = 0;
1269 		c->highspeed = 0;
1270 		c->fullspeed = 0;
1271 	}
1272 }
1273 
1274 static int configfs_composite_bind(struct usb_gadget *gadget,
1275 		struct usb_gadget_driver *gdriver)
1276 {
1277 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1278 	struct gadget_info		*gi = container_of(composite,
1279 						struct gadget_info, composite);
1280 	struct usb_composite_dev	*cdev = &gi->cdev;
1281 	struct usb_configuration	*c;
1282 	struct usb_string		*s;
1283 	unsigned			i;
1284 	int				ret;
1285 
1286 	/* the gi->lock is hold by the caller */
1287 	gi->unbind = 0;
1288 	cdev->gadget = gadget;
1289 	set_gadget_data(gadget, cdev);
1290 	ret = composite_dev_prepare(composite, cdev);
1291 	if (ret)
1292 		return ret;
1293 	/* and now the gadget bind */
1294 	ret = -EINVAL;
1295 
1296 	if (list_empty(&gi->cdev.configs)) {
1297 		pr_err("Need at least one configuration in %s.\n",
1298 				gi->composite.name);
1299 		goto err_comp_cleanup;
1300 	}
1301 
1302 
1303 	list_for_each_entry(c, &gi->cdev.configs, list) {
1304 		struct config_usb_cfg *cfg;
1305 
1306 		cfg = container_of(c, struct config_usb_cfg, c);
1307 		if (list_empty(&cfg->func_list)) {
1308 			pr_err("Config %s/%d of %s needs at least one function.\n",
1309 			      c->label, c->bConfigurationValue,
1310 			      gi->composite.name);
1311 			goto err_comp_cleanup;
1312 		}
1313 	}
1314 
1315 	/* init all strings */
1316 	if (!list_empty(&gi->string_list)) {
1317 		struct gadget_strings *gs;
1318 
1319 		i = 0;
1320 		list_for_each_entry(gs, &gi->string_list, list) {
1321 
1322 			gi->gstrings[i] = &gs->stringtab_dev;
1323 			gs->stringtab_dev.strings = gs->strings;
1324 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1325 				gs->manufacturer;
1326 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1327 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1328 			i++;
1329 		}
1330 		gi->gstrings[i] = NULL;
1331 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1332 				USB_GADGET_FIRST_AVAIL_IDX);
1333 		if (IS_ERR(s)) {
1334 			ret = PTR_ERR(s);
1335 			goto err_comp_cleanup;
1336 		}
1337 
1338 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1339 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1340 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1341 	}
1342 
1343 	if (gi->use_os_desc) {
1344 		cdev->use_os_string = true;
1345 		cdev->b_vendor_code = gi->b_vendor_code;
1346 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1347 	}
1348 
1349 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1350 		struct usb_descriptor_header *usb_desc;
1351 
1352 		usb_desc = usb_otg_descriptor_alloc(gadget);
1353 		if (!usb_desc) {
1354 			ret = -ENOMEM;
1355 			goto err_comp_cleanup;
1356 		}
1357 		usb_otg_descriptor_init(gadget, usb_desc);
1358 		otg_desc[0] = usb_desc;
1359 		otg_desc[1] = NULL;
1360 	}
1361 
1362 	/* Go through all configs, attach all functions */
1363 	list_for_each_entry(c, &gi->cdev.configs, list) {
1364 		struct config_usb_cfg *cfg;
1365 		struct usb_function *f;
1366 		struct usb_function *tmp;
1367 		struct gadget_config_name *cn;
1368 
1369 		if (gadget_is_otg(gadget))
1370 			c->descriptors = otg_desc;
1371 
1372 		cfg = container_of(c, struct config_usb_cfg, c);
1373 		if (!list_empty(&cfg->string_list)) {
1374 			i = 0;
1375 			list_for_each_entry(cn, &cfg->string_list, list) {
1376 				cfg->gstrings[i] = &cn->stringtab_dev;
1377 				cn->stringtab_dev.strings = &cn->strings;
1378 				cn->strings.s = cn->configuration;
1379 				i++;
1380 			}
1381 			cfg->gstrings[i] = NULL;
1382 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1383 			if (IS_ERR(s)) {
1384 				ret = PTR_ERR(s);
1385 				goto err_comp_cleanup;
1386 			}
1387 			c->iConfiguration = s[0].id;
1388 		}
1389 
1390 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1391 			list_del(&f->list);
1392 			ret = usb_add_function(c, f);
1393 			if (ret) {
1394 				list_add(&f->list, &cfg->func_list);
1395 				goto err_purge_funcs;
1396 			}
1397 		}
1398 		ret = usb_gadget_check_config(cdev->gadget);
1399 		if (ret)
1400 			goto err_purge_funcs;
1401 
1402 		usb_ep_autoconfig_reset(cdev->gadget);
1403 	}
1404 	if (cdev->use_os_string) {
1405 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1406 		if (ret)
1407 			goto err_purge_funcs;
1408 	}
1409 
1410 	usb_ep_autoconfig_reset(cdev->gadget);
1411 	return 0;
1412 
1413 err_purge_funcs:
1414 	purge_configs_funcs(gi);
1415 err_comp_cleanup:
1416 	composite_dev_cleanup(cdev);
1417 	return ret;
1418 }
1419 
1420 static void configfs_composite_unbind(struct usb_gadget *gadget)
1421 {
1422 	struct usb_composite_dev	*cdev;
1423 	struct gadget_info		*gi;
1424 	unsigned long flags;
1425 
1426 	/* the gi->lock is hold by the caller */
1427 
1428 	cdev = get_gadget_data(gadget);
1429 	gi = container_of(cdev, struct gadget_info, cdev);
1430 	spin_lock_irqsave(&gi->spinlock, flags);
1431 	gi->unbind = 1;
1432 	spin_unlock_irqrestore(&gi->spinlock, flags);
1433 
1434 	kfree(otg_desc[0]);
1435 	otg_desc[0] = NULL;
1436 	purge_configs_funcs(gi);
1437 	composite_dev_cleanup(cdev);
1438 	usb_ep_autoconfig_reset(cdev->gadget);
1439 	spin_lock_irqsave(&gi->spinlock, flags);
1440 	cdev->gadget = NULL;
1441 	cdev->deactivations = 0;
1442 	gadget->deactivated = false;
1443 	set_gadget_data(gadget, NULL);
1444 	spin_unlock_irqrestore(&gi->spinlock, flags);
1445 }
1446 
1447 static int configfs_composite_setup(struct usb_gadget *gadget,
1448 		const struct usb_ctrlrequest *ctrl)
1449 {
1450 	struct usb_composite_dev *cdev;
1451 	struct gadget_info *gi;
1452 	unsigned long flags;
1453 	int ret;
1454 
1455 	cdev = get_gadget_data(gadget);
1456 	if (!cdev)
1457 		return 0;
1458 
1459 	gi = container_of(cdev, struct gadget_info, cdev);
1460 	spin_lock_irqsave(&gi->spinlock, flags);
1461 	cdev = get_gadget_data(gadget);
1462 	if (!cdev || gi->unbind) {
1463 		spin_unlock_irqrestore(&gi->spinlock, flags);
1464 		return 0;
1465 	}
1466 
1467 	ret = composite_setup(gadget, ctrl);
1468 	spin_unlock_irqrestore(&gi->spinlock, flags);
1469 	return ret;
1470 }
1471 
1472 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1473 {
1474 	struct usb_composite_dev *cdev;
1475 	struct gadget_info *gi;
1476 	unsigned long flags;
1477 
1478 	cdev = get_gadget_data(gadget);
1479 	if (!cdev)
1480 		return;
1481 
1482 	gi = container_of(cdev, struct gadget_info, cdev);
1483 	spin_lock_irqsave(&gi->spinlock, flags);
1484 	cdev = get_gadget_data(gadget);
1485 	if (!cdev || gi->unbind) {
1486 		spin_unlock_irqrestore(&gi->spinlock, flags);
1487 		return;
1488 	}
1489 
1490 	composite_disconnect(gadget);
1491 	spin_unlock_irqrestore(&gi->spinlock, flags);
1492 }
1493 
1494 static void configfs_composite_reset(struct usb_gadget *gadget)
1495 {
1496 	struct usb_composite_dev *cdev;
1497 	struct gadget_info *gi;
1498 	unsigned long flags;
1499 
1500 	cdev = get_gadget_data(gadget);
1501 	if (!cdev)
1502 		return;
1503 
1504 	gi = container_of(cdev, struct gadget_info, cdev);
1505 	spin_lock_irqsave(&gi->spinlock, flags);
1506 	cdev = get_gadget_data(gadget);
1507 	if (!cdev || gi->unbind) {
1508 		spin_unlock_irqrestore(&gi->spinlock, flags);
1509 		return;
1510 	}
1511 
1512 	composite_reset(gadget);
1513 	spin_unlock_irqrestore(&gi->spinlock, flags);
1514 }
1515 
1516 static void configfs_composite_suspend(struct usb_gadget *gadget)
1517 {
1518 	struct usb_composite_dev *cdev;
1519 	struct gadget_info *gi;
1520 	unsigned long flags;
1521 
1522 	cdev = get_gadget_data(gadget);
1523 	if (!cdev)
1524 		return;
1525 
1526 	gi = container_of(cdev, struct gadget_info, cdev);
1527 	spin_lock_irqsave(&gi->spinlock, flags);
1528 	cdev = get_gadget_data(gadget);
1529 	if (!cdev || gi->unbind) {
1530 		spin_unlock_irqrestore(&gi->spinlock, flags);
1531 		return;
1532 	}
1533 
1534 	composite_suspend(gadget);
1535 	spin_unlock_irqrestore(&gi->spinlock, flags);
1536 }
1537 
1538 static void configfs_composite_resume(struct usb_gadget *gadget)
1539 {
1540 	struct usb_composite_dev *cdev;
1541 	struct gadget_info *gi;
1542 	unsigned long flags;
1543 
1544 	cdev = get_gadget_data(gadget);
1545 	if (!cdev)
1546 		return;
1547 
1548 	gi = container_of(cdev, struct gadget_info, cdev);
1549 	spin_lock_irqsave(&gi->spinlock, flags);
1550 	cdev = get_gadget_data(gadget);
1551 	if (!cdev || gi->unbind) {
1552 		spin_unlock_irqrestore(&gi->spinlock, flags);
1553 		return;
1554 	}
1555 
1556 	composite_resume(gadget);
1557 	spin_unlock_irqrestore(&gi->spinlock, flags);
1558 }
1559 
1560 static const struct usb_gadget_driver configfs_driver_template = {
1561 	.bind           = configfs_composite_bind,
1562 	.unbind         = configfs_composite_unbind,
1563 
1564 	.setup          = configfs_composite_setup,
1565 	.reset          = configfs_composite_reset,
1566 	.disconnect     = configfs_composite_disconnect,
1567 
1568 	.suspend	= configfs_composite_suspend,
1569 	.resume		= configfs_composite_resume,
1570 
1571 	.max_speed	= USB_SPEED_SUPER_PLUS,
1572 	.driver = {
1573 		.owner          = THIS_MODULE,
1574 		.name		= "configfs-gadget",
1575 	},
1576 	.match_existing_only = 1,
1577 };
1578 
1579 static struct config_group *gadgets_make(
1580 		struct config_group *group,
1581 		const char *name)
1582 {
1583 	struct gadget_info *gi;
1584 
1585 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1586 	if (!gi)
1587 		return ERR_PTR(-ENOMEM);
1588 
1589 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1590 
1591 	config_group_init_type_name(&gi->functions_group, "functions",
1592 			&functions_type);
1593 	configfs_add_default_group(&gi->functions_group, &gi->group);
1594 
1595 	config_group_init_type_name(&gi->configs_group, "configs",
1596 			&config_desc_type);
1597 	configfs_add_default_group(&gi->configs_group, &gi->group);
1598 
1599 	config_group_init_type_name(&gi->strings_group, "strings",
1600 			&gadget_strings_strings_type);
1601 	configfs_add_default_group(&gi->strings_group, &gi->group);
1602 
1603 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1604 			&os_desc_type);
1605 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1606 
1607 	gi->composite.bind = configfs_do_nothing;
1608 	gi->composite.unbind = configfs_do_nothing;
1609 	gi->composite.suspend = NULL;
1610 	gi->composite.resume = NULL;
1611 	gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
1612 
1613 	spin_lock_init(&gi->spinlock);
1614 	mutex_init(&gi->lock);
1615 	INIT_LIST_HEAD(&gi->string_list);
1616 	INIT_LIST_HEAD(&gi->available_func);
1617 
1618 	composite_init_dev(&gi->cdev);
1619 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1620 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1621 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1622 
1623 	gi->composite.gadget_driver = configfs_driver_template;
1624 
1625 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1626 	gi->composite.name = gi->composite.gadget_driver.function;
1627 
1628 	if (!gi->composite.gadget_driver.function)
1629 		goto err;
1630 
1631 	return &gi->group;
1632 err:
1633 	kfree(gi);
1634 	return ERR_PTR(-ENOMEM);
1635 }
1636 
1637 static void gadgets_drop(struct config_group *group, struct config_item *item)
1638 {
1639 	config_item_put(item);
1640 }
1641 
1642 static struct configfs_group_operations gadgets_ops = {
1643 	.make_group     = &gadgets_make,
1644 	.drop_item      = &gadgets_drop,
1645 };
1646 
1647 static const struct config_item_type gadgets_type = {
1648 	.ct_group_ops   = &gadgets_ops,
1649 	.ct_owner       = THIS_MODULE,
1650 };
1651 
1652 static struct configfs_subsystem gadget_subsys = {
1653 	.su_group = {
1654 		.cg_item = {
1655 			.ci_namebuf = "usb_gadget",
1656 			.ci_type = &gadgets_type,
1657 		},
1658 	},
1659 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1660 };
1661 
1662 void unregister_gadget_item(struct config_item *item)
1663 {
1664 	struct gadget_info *gi = to_gadget_info(item);
1665 
1666 	mutex_lock(&gi->lock);
1667 	unregister_gadget(gi);
1668 	mutex_unlock(&gi->lock);
1669 }
1670 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1671 
1672 static int __init gadget_cfs_init(void)
1673 {
1674 	int ret;
1675 
1676 	config_group_init(&gadget_subsys.su_group);
1677 
1678 	ret = configfs_register_subsystem(&gadget_subsys);
1679 	return ret;
1680 }
1681 module_init(gadget_cfs_init);
1682 
1683 static void __exit gadget_cfs_exit(void)
1684 {
1685 	configfs_unregister_subsystem(&gadget_subsys);
1686 }
1687 module_exit(gadget_cfs_exit);
1688