xref: /openbmc/linux/drivers/usb/gadget/configfs.c (revision 9cfc5c90) 
1 #include <linux/configfs.h>
2 #include <linux/module.h>
3 #include <linux/slab.h>
4 #include <linux/device.h>
5 #include <linux/nls.h>
6 #include <linux/usb/composite.h>
7 #include <linux/usb/gadget_configfs.h>
8 #include "configfs.h"
9 #include "u_f.h"
10 #include "u_os_desc.h"
11 
12 int check_user_usb_string(const char *name,
13 		struct usb_gadget_strings *stringtab_dev)
14 {
15 	unsigned primary_lang;
16 	unsigned sub_lang;
17 	u16 num;
18 	int ret;
19 
20 	ret = kstrtou16(name, 0, &num);
21 	if (ret)
22 		return ret;
23 
24 	primary_lang = num & 0x3ff;
25 	sub_lang = num >> 10;
26 
27 	/* simple sanity check for valid langid */
28 	switch (primary_lang) {
29 	case 0:
30 	case 0x62 ... 0xfe:
31 	case 0x100 ... 0x3ff:
32 		return -EINVAL;
33 	}
34 	if (!sub_lang)
35 		return -EINVAL;
36 
37 	stringtab_dev->language = num;
38 	return 0;
39 }
40 
41 #define MAX_NAME_LEN	40
42 #define MAX_USB_STRING_LANGS 2
43 
44 static const struct usb_descriptor_header *otg_desc[2];
45 
46 struct gadget_info {
47 	struct config_group group;
48 	struct config_group functions_group;
49 	struct config_group configs_group;
50 	struct config_group strings_group;
51 	struct config_group os_desc_group;
52 	struct config_group *default_groups[5];
53 
54 	struct mutex lock;
55 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
56 	struct list_head string_list;
57 	struct list_head available_func;
58 
59 	const char *udc_name;
60 	struct usb_composite_driver composite;
61 	struct usb_composite_dev cdev;
62 	bool use_os_desc;
63 	char b_vendor_code;
64 	char qw_sign[OS_STRING_QW_SIGN_LEN];
65 };
66 
67 static inline struct gadget_info *to_gadget_info(struct config_item *item)
68 {
69 	 return container_of(to_config_group(item), struct gadget_info, group);
70 }
71 
72 struct config_usb_cfg {
73 	struct config_group group;
74 	struct config_group strings_group;
75 	struct config_group *default_groups[2];
76 	struct list_head string_list;
77 	struct usb_configuration c;
78 	struct list_head func_list;
79 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
80 };
81 
82 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
83 {
84 	return container_of(to_config_group(item), struct config_usb_cfg,
85 			group);
86 }
87 
88 struct gadget_strings {
89 	struct usb_gadget_strings stringtab_dev;
90 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
91 	char *manufacturer;
92 	char *product;
93 	char *serialnumber;
94 
95 	struct config_group group;
96 	struct list_head list;
97 };
98 
99 struct os_desc {
100 	struct config_group group;
101 };
102 
103 struct gadget_config_name {
104 	struct usb_gadget_strings stringtab_dev;
105 	struct usb_string strings;
106 	char *configuration;
107 
108 	struct config_group group;
109 	struct list_head list;
110 };
111 
112 static int usb_string_copy(const char *s, char **s_copy)
113 {
114 	int ret;
115 	char *str;
116 	char *copy = *s_copy;
117 	ret = strlen(s);
118 	if (ret > 126)
119 		return -EOVERFLOW;
120 
121 	str = kstrdup(s, GFP_KERNEL);
122 	if (!str)
123 		return -ENOMEM;
124 	if (str[ret - 1] == '\n')
125 		str[ret - 1] = '\0';
126 	kfree(copy);
127 	*s_copy = str;
128 	return 0;
129 }
130 
131 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
132 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
133 			char *page)	\
134 {	\
135 	return sprintf(page, "0x%02x\n", \
136 		to_gadget_info(item)->cdev.desc.__name); \
137 }
138 
139 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
140 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
141 			char *page)	\
142 {	\
143 	return sprintf(page, "0x%04x\n", \
144 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
145 }
146 
147 
148 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
149 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
150 		const char *page, size_t len)		\
151 {							\
152 	u8 val;						\
153 	int ret;					\
154 	ret = kstrtou8(page, 0, &val);			\
155 	if (ret)					\
156 		return ret;				\
157 	to_gadget_info(item)->cdev.desc._name = val;	\
158 	return len;					\
159 }
160 
161 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
162 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
163 		const char *page, size_t len)		\
164 {							\
165 	u16 val;					\
166 	int ret;					\
167 	ret = kstrtou16(page, 0, &val);			\
168 	if (ret)					\
169 		return ret;				\
170 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
171 	return len;					\
172 }
173 
174 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
175 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
176 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
177 
178 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
179 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
180 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
181 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
182 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
183 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
184 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
185 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
186 
187 static ssize_t is_valid_bcd(u16 bcd_val)
188 {
189 	if ((bcd_val & 0xf) > 9)
190 		return -EINVAL;
191 	if (((bcd_val >> 4) & 0xf) > 9)
192 		return -EINVAL;
193 	if (((bcd_val >> 8) & 0xf) > 9)
194 		return -EINVAL;
195 	if (((bcd_val >> 12) & 0xf) > 9)
196 		return -EINVAL;
197 	return 0;
198 }
199 
200 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
201 		const char *page, size_t len)
202 {
203 	u16 bcdDevice;
204 	int ret;
205 
206 	ret = kstrtou16(page, 0, &bcdDevice);
207 	if (ret)
208 		return ret;
209 	ret = is_valid_bcd(bcdDevice);
210 	if (ret)
211 		return ret;
212 
213 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
214 	return len;
215 }
216 
217 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
218 		const char *page, size_t len)
219 {
220 	u16 bcdUSB;
221 	int ret;
222 
223 	ret = kstrtou16(page, 0, &bcdUSB);
224 	if (ret)
225 		return ret;
226 	ret = is_valid_bcd(bcdUSB);
227 	if (ret)
228 		return ret;
229 
230 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
231 	return len;
232 }
233 
234 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
235 {
236 	return sprintf(page, "%s\n", to_gadget_info(item)->udc_name ?: "");
237 }
238 
239 static int unregister_gadget(struct gadget_info *gi)
240 {
241 	int ret;
242 
243 	if (!gi->udc_name)
244 		return -ENODEV;
245 
246 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
247 	if (ret)
248 		return ret;
249 	kfree(gi->udc_name);
250 	gi->udc_name = NULL;
251 	return 0;
252 }
253 
254 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
255 		const char *page, size_t len)
256 {
257 	struct gadget_info *gi = to_gadget_info(item);
258 	char *name;
259 	int ret;
260 
261 	name = kstrdup(page, GFP_KERNEL);
262 	if (!name)
263 		return -ENOMEM;
264 	if (name[len - 1] == '\n')
265 		name[len - 1] = '\0';
266 
267 	mutex_lock(&gi->lock);
268 
269 	if (!strlen(name)) {
270 		ret = unregister_gadget(gi);
271 		if (ret)
272 			goto err;
273 	} else {
274 		if (gi->udc_name) {
275 			ret = -EBUSY;
276 			goto err;
277 		}
278 		ret = usb_udc_attach_driver(name, &gi->composite.gadget_driver);
279 		if (ret)
280 			goto err;
281 		gi->udc_name = name;
282 	}
283 	mutex_unlock(&gi->lock);
284 	return len;
285 err:
286 	kfree(name);
287 	mutex_unlock(&gi->lock);
288 	return ret;
289 }
290 
291 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
292 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
293 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
294 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
295 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
296 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
297 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
298 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
299 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
300 
301 static struct configfs_attribute *gadget_root_attrs[] = {
302 	&gadget_dev_desc_attr_bDeviceClass,
303 	&gadget_dev_desc_attr_bDeviceSubClass,
304 	&gadget_dev_desc_attr_bDeviceProtocol,
305 	&gadget_dev_desc_attr_bMaxPacketSize0,
306 	&gadget_dev_desc_attr_idVendor,
307 	&gadget_dev_desc_attr_idProduct,
308 	&gadget_dev_desc_attr_bcdDevice,
309 	&gadget_dev_desc_attr_bcdUSB,
310 	&gadget_dev_desc_attr_UDC,
311 	NULL,
312 };
313 
314 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
315 {
316 	 return container_of(to_config_group(item), struct gadget_strings,
317 			 group);
318 }
319 
320 static inline struct gadget_config_name *to_gadget_config_name(
321 		struct config_item *item)
322 {
323 	 return container_of(to_config_group(item), struct gadget_config_name,
324 			 group);
325 }
326 
327 static inline struct usb_function_instance *to_usb_function_instance(
328 		struct config_item *item)
329 {
330 	 return container_of(to_config_group(item),
331 			 struct usb_function_instance, group);
332 }
333 
334 static void gadget_info_attr_release(struct config_item *item)
335 {
336 	struct gadget_info *gi = to_gadget_info(item);
337 
338 	WARN_ON(!list_empty(&gi->cdev.configs));
339 	WARN_ON(!list_empty(&gi->string_list));
340 	WARN_ON(!list_empty(&gi->available_func));
341 	kfree(gi->composite.gadget_driver.function);
342 	kfree(gi);
343 }
344 
345 static struct configfs_item_operations gadget_root_item_ops = {
346 	.release                = gadget_info_attr_release,
347 };
348 
349 static void gadget_config_attr_release(struct config_item *item)
350 {
351 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
352 
353 	WARN_ON(!list_empty(&cfg->c.functions));
354 	list_del(&cfg->c.list);
355 	kfree(cfg->c.label);
356 	kfree(cfg);
357 }
358 
359 static int config_usb_cfg_link(
360 	struct config_item *usb_cfg_ci,
361 	struct config_item *usb_func_ci)
362 {
363 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
364 	struct usb_composite_dev *cdev = cfg->c.cdev;
365 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
366 
367 	struct config_group *group = to_config_group(usb_func_ci);
368 	struct usb_function_instance *fi = container_of(group,
369 			struct usb_function_instance, group);
370 	struct usb_function_instance *a_fi;
371 	struct usb_function *f;
372 	int ret;
373 
374 	mutex_lock(&gi->lock);
375 	/*
376 	 * Make sure this function is from within our _this_ gadget and not
377 	 * from another gadget or a random directory.
378 	 * Also a function instance can only be linked once.
379 	 */
380 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
381 		if (a_fi == fi)
382 			break;
383 	}
384 	if (a_fi != fi) {
385 		ret = -EINVAL;
386 		goto out;
387 	}
388 
389 	list_for_each_entry(f, &cfg->func_list, list) {
390 		if (f->fi == fi) {
391 			ret = -EEXIST;
392 			goto out;
393 		}
394 	}
395 
396 	f = usb_get_function(fi);
397 	if (IS_ERR(f)) {
398 		ret = PTR_ERR(f);
399 		goto out;
400 	}
401 
402 	/* stash the function until we bind it to the gadget */
403 	list_add_tail(&f->list, &cfg->func_list);
404 	ret = 0;
405 out:
406 	mutex_unlock(&gi->lock);
407 	return ret;
408 }
409 
410 static int config_usb_cfg_unlink(
411 	struct config_item *usb_cfg_ci,
412 	struct config_item *usb_func_ci)
413 {
414 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
415 	struct usb_composite_dev *cdev = cfg->c.cdev;
416 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
417 
418 	struct config_group *group = to_config_group(usb_func_ci);
419 	struct usb_function_instance *fi = container_of(group,
420 			struct usb_function_instance, group);
421 	struct usb_function *f;
422 
423 	/*
424 	 * ideally I would like to forbid to unlink functions while a gadget is
425 	 * bound to an UDC. Since this isn't possible at the moment, we simply
426 	 * force an unbind, the function is available here and then we can
427 	 * remove the function.
428 	 */
429 	mutex_lock(&gi->lock);
430 	if (gi->udc_name)
431 		unregister_gadget(gi);
432 	WARN_ON(gi->udc_name);
433 
434 	list_for_each_entry(f, &cfg->func_list, list) {
435 		if (f->fi == fi) {
436 			list_del(&f->list);
437 			usb_put_function(f);
438 			mutex_unlock(&gi->lock);
439 			return 0;
440 		}
441 	}
442 	mutex_unlock(&gi->lock);
443 	WARN(1, "Unable to locate function to unbind\n");
444 	return 0;
445 }
446 
447 static struct configfs_item_operations gadget_config_item_ops = {
448 	.release                = gadget_config_attr_release,
449 	.allow_link             = config_usb_cfg_link,
450 	.drop_link              = config_usb_cfg_unlink,
451 };
452 
453 
454 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
455 		char *page)
456 {
457 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
458 }
459 
460 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
461 		const char *page, size_t len)
462 {
463 	u16 val;
464 	int ret;
465 	ret = kstrtou16(page, 0, &val);
466 	if (ret)
467 		return ret;
468 	if (DIV_ROUND_UP(val, 8) > 0xff)
469 		return -ERANGE;
470 	to_config_usb_cfg(item)->c.MaxPower = val;
471 	return len;
472 }
473 
474 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
475 		char *page)
476 {
477 	return sprintf(page, "0x%02x\n",
478 		to_config_usb_cfg(item)->c.bmAttributes);
479 }
480 
481 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
482 		const char *page, size_t len)
483 {
484 	u8 val;
485 	int ret;
486 	ret = kstrtou8(page, 0, &val);
487 	if (ret)
488 		return ret;
489 	if (!(val & USB_CONFIG_ATT_ONE))
490 		return -EINVAL;
491 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
492 				USB_CONFIG_ATT_WAKEUP))
493 		return -EINVAL;
494 	to_config_usb_cfg(item)->c.bmAttributes = val;
495 	return len;
496 }
497 
498 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
499 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
500 
501 static struct configfs_attribute *gadget_config_attrs[] = {
502 	&gadget_config_desc_attr_MaxPower,
503 	&gadget_config_desc_attr_bmAttributes,
504 	NULL,
505 };
506 
507 static struct config_item_type gadget_config_type = {
508 	.ct_item_ops	= &gadget_config_item_ops,
509 	.ct_attrs	= gadget_config_attrs,
510 	.ct_owner	= THIS_MODULE,
511 };
512 
513 static struct config_item_type gadget_root_type = {
514 	.ct_item_ops	= &gadget_root_item_ops,
515 	.ct_attrs	= gadget_root_attrs,
516 	.ct_owner	= THIS_MODULE,
517 };
518 
519 static void composite_init_dev(struct usb_composite_dev *cdev)
520 {
521 	spin_lock_init(&cdev->lock);
522 	INIT_LIST_HEAD(&cdev->configs);
523 	INIT_LIST_HEAD(&cdev->gstrings);
524 }
525 
526 static struct config_group *function_make(
527 		struct config_group *group,
528 		const char *name)
529 {
530 	struct gadget_info *gi;
531 	struct usb_function_instance *fi;
532 	char buf[MAX_NAME_LEN];
533 	char *func_name;
534 	char *instance_name;
535 	int ret;
536 
537 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
538 	if (ret >= MAX_NAME_LEN)
539 		return ERR_PTR(-ENAMETOOLONG);
540 
541 	func_name = buf;
542 	instance_name = strchr(func_name, '.');
543 	if (!instance_name) {
544 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
545 		return ERR_PTR(-EINVAL);
546 	}
547 	*instance_name = '\0';
548 	instance_name++;
549 
550 	fi = usb_get_function_instance(func_name);
551 	if (IS_ERR(fi))
552 		return ERR_CAST(fi);
553 
554 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
555 	if (ret) {
556 		usb_put_function_instance(fi);
557 		return ERR_PTR(ret);
558 	}
559 	if (fi->set_inst_name) {
560 		ret = fi->set_inst_name(fi, instance_name);
561 		if (ret) {
562 			usb_put_function_instance(fi);
563 			return ERR_PTR(ret);
564 		}
565 	}
566 
567 	gi = container_of(group, struct gadget_info, functions_group);
568 
569 	mutex_lock(&gi->lock);
570 	list_add_tail(&fi->cfs_list, &gi->available_func);
571 	mutex_unlock(&gi->lock);
572 	return &fi->group;
573 }
574 
575 static void function_drop(
576 		struct config_group *group,
577 		struct config_item *item)
578 {
579 	struct usb_function_instance *fi = to_usb_function_instance(item);
580 	struct gadget_info *gi;
581 
582 	gi = container_of(group, struct gadget_info, functions_group);
583 
584 	mutex_lock(&gi->lock);
585 	list_del(&fi->cfs_list);
586 	mutex_unlock(&gi->lock);
587 	config_item_put(item);
588 }
589 
590 static struct configfs_group_operations functions_ops = {
591 	.make_group     = &function_make,
592 	.drop_item      = &function_drop,
593 };
594 
595 static struct config_item_type functions_type = {
596 	.ct_group_ops   = &functions_ops,
597 	.ct_owner       = THIS_MODULE,
598 };
599 
600 GS_STRINGS_RW(gadget_config_name, configuration);
601 
602 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
603 	&gadget_config_name_attr_configuration,
604 	NULL,
605 };
606 
607 static void gadget_config_name_attr_release(struct config_item *item)
608 {
609 	struct gadget_config_name *cn = to_gadget_config_name(item);
610 
611 	kfree(cn->configuration);
612 
613 	list_del(&cn->list);
614 	kfree(cn);
615 }
616 
617 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
618 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
619 
620 static struct config_group *config_desc_make(
621 		struct config_group *group,
622 		const char *name)
623 {
624 	struct gadget_info *gi;
625 	struct config_usb_cfg *cfg;
626 	char buf[MAX_NAME_LEN];
627 	char *num_str;
628 	u8 num;
629 	int ret;
630 
631 	gi = container_of(group, struct gadget_info, configs_group);
632 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
633 	if (ret >= MAX_NAME_LEN)
634 		return ERR_PTR(-ENAMETOOLONG);
635 
636 	num_str = strchr(buf, '.');
637 	if (!num_str) {
638 		pr_err("Unable to locate . in name.bConfigurationValue\n");
639 		return ERR_PTR(-EINVAL);
640 	}
641 
642 	*num_str = '\0';
643 	num_str++;
644 
645 	if (!strlen(buf))
646 		return ERR_PTR(-EINVAL);
647 
648 	ret = kstrtou8(num_str, 0, &num);
649 	if (ret)
650 		return ERR_PTR(ret);
651 
652 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
653 	if (!cfg)
654 		return ERR_PTR(-ENOMEM);
655 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
656 	if (!cfg->c.label) {
657 		ret = -ENOMEM;
658 		goto err;
659 	}
660 	cfg->c.bConfigurationValue = num;
661 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
662 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
663 	INIT_LIST_HEAD(&cfg->string_list);
664 	INIT_LIST_HEAD(&cfg->func_list);
665 
666 	cfg->group.default_groups = cfg->default_groups;
667 	cfg->default_groups[0] = &cfg->strings_group;
668 
669 	config_group_init_type_name(&cfg->group, name,
670 				&gadget_config_type);
671 	config_group_init_type_name(&cfg->strings_group, "strings",
672 			&gadget_config_name_strings_type);
673 
674 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
675 	if (ret)
676 		goto err;
677 
678 	return &cfg->group;
679 err:
680 	kfree(cfg->c.label);
681 	kfree(cfg);
682 	return ERR_PTR(ret);
683 }
684 
685 static void config_desc_drop(
686 		struct config_group *group,
687 		struct config_item *item)
688 {
689 	config_item_put(item);
690 }
691 
692 static struct configfs_group_operations config_desc_ops = {
693 	.make_group     = &config_desc_make,
694 	.drop_item      = &config_desc_drop,
695 };
696 
697 static struct config_item_type config_desc_type = {
698 	.ct_group_ops   = &config_desc_ops,
699 	.ct_owner       = THIS_MODULE,
700 };
701 
702 GS_STRINGS_RW(gadget_strings, manufacturer);
703 GS_STRINGS_RW(gadget_strings, product);
704 GS_STRINGS_RW(gadget_strings, serialnumber);
705 
706 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
707 	&gadget_strings_attr_manufacturer,
708 	&gadget_strings_attr_product,
709 	&gadget_strings_attr_serialnumber,
710 	NULL,
711 };
712 
713 static void gadget_strings_attr_release(struct config_item *item)
714 {
715 	struct gadget_strings *gs = to_gadget_strings(item);
716 
717 	kfree(gs->manufacturer);
718 	kfree(gs->product);
719 	kfree(gs->serialnumber);
720 
721 	list_del(&gs->list);
722 	kfree(gs);
723 }
724 
725 USB_CONFIG_STRING_RW_OPS(gadget_strings);
726 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
727 
728 static inline struct os_desc *to_os_desc(struct config_item *item)
729 {
730 	return container_of(to_config_group(item), struct os_desc, group);
731 }
732 
733 static inline struct gadget_info *os_desc_item_to_gadget_info(
734 		struct config_item *item)
735 {
736 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
737 }
738 
739 static ssize_t os_desc_use_show(struct config_item *item, char *page)
740 {
741 	return sprintf(page, "%d",
742 			os_desc_item_to_gadget_info(item)->use_os_desc);
743 }
744 
745 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
746 				 size_t len)
747 {
748 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
749 	int ret;
750 	bool use;
751 
752 	mutex_lock(&gi->lock);
753 	ret = strtobool(page, &use);
754 	if (!ret) {
755 		gi->use_os_desc = use;
756 		ret = len;
757 	}
758 	mutex_unlock(&gi->lock);
759 
760 	return ret;
761 }
762 
763 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
764 {
765 	return sprintf(page, "%d",
766 			os_desc_item_to_gadget_info(item)->b_vendor_code);
767 }
768 
769 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
770 					   const char *page, size_t len)
771 {
772 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
773 	int ret;
774 	u8 b_vendor_code;
775 
776 	mutex_lock(&gi->lock);
777 	ret = kstrtou8(page, 0, &b_vendor_code);
778 	if (!ret) {
779 		gi->b_vendor_code = b_vendor_code;
780 		ret = len;
781 	}
782 	mutex_unlock(&gi->lock);
783 
784 	return ret;
785 }
786 
787 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
788 {
789 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
790 
791 	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
792 	return OS_STRING_QW_SIGN_LEN;
793 }
794 
795 static ssize_t os_desc_qw_sign_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 res, l;
800 
801 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
802 	if (page[l - 1] == '\n')
803 		--l;
804 
805 	mutex_lock(&gi->lock);
806 	res = utf8s_to_utf16s(page, l,
807 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
808 			      OS_STRING_QW_SIGN_LEN);
809 	if (res > 0)
810 		res = len;
811 	mutex_unlock(&gi->lock);
812 
813 	return res;
814 }
815 
816 CONFIGFS_ATTR(os_desc_, use);
817 CONFIGFS_ATTR(os_desc_, b_vendor_code);
818 CONFIGFS_ATTR(os_desc_, qw_sign);
819 
820 static struct configfs_attribute *os_desc_attrs[] = {
821 	&os_desc_attr_use,
822 	&os_desc_attr_b_vendor_code,
823 	&os_desc_attr_qw_sign,
824 	NULL,
825 };
826 
827 static void os_desc_attr_release(struct config_item *item)
828 {
829 	struct os_desc *os_desc = to_os_desc(item);
830 	kfree(os_desc);
831 }
832 
833 static int os_desc_link(struct config_item *os_desc_ci,
834 			struct config_item *usb_cfg_ci)
835 {
836 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
837 					struct gadget_info, os_desc_group);
838 	struct usb_composite_dev *cdev = &gi->cdev;
839 	struct config_usb_cfg *c_target =
840 		container_of(to_config_group(usb_cfg_ci),
841 			     struct config_usb_cfg, group);
842 	struct usb_configuration *c;
843 	int ret;
844 
845 	mutex_lock(&gi->lock);
846 	list_for_each_entry(c, &cdev->configs, list) {
847 		if (c == &c_target->c)
848 			break;
849 	}
850 	if (c != &c_target->c) {
851 		ret = -EINVAL;
852 		goto out;
853 	}
854 
855 	if (cdev->os_desc_config) {
856 		ret = -EBUSY;
857 		goto out;
858 	}
859 
860 	cdev->os_desc_config = &c_target->c;
861 	ret = 0;
862 
863 out:
864 	mutex_unlock(&gi->lock);
865 	return ret;
866 }
867 
868 static int os_desc_unlink(struct config_item *os_desc_ci,
869 			  struct config_item *usb_cfg_ci)
870 {
871 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
872 					struct gadget_info, os_desc_group);
873 	struct usb_composite_dev *cdev = &gi->cdev;
874 
875 	mutex_lock(&gi->lock);
876 	if (gi->udc_name)
877 		unregister_gadget(gi);
878 	cdev->os_desc_config = NULL;
879 	WARN_ON(gi->udc_name);
880 	mutex_unlock(&gi->lock);
881 	return 0;
882 }
883 
884 static struct configfs_item_operations os_desc_ops = {
885 	.release                = os_desc_attr_release,
886 	.allow_link		= os_desc_link,
887 	.drop_link		= os_desc_unlink,
888 };
889 
890 static struct config_item_type os_desc_type = {
891 	.ct_item_ops	= &os_desc_ops,
892 	.ct_attrs	= os_desc_attrs,
893 	.ct_owner	= THIS_MODULE,
894 };
895 
896 static inline struct usb_os_desc_ext_prop
897 *to_usb_os_desc_ext_prop(struct config_item *item)
898 {
899 	return container_of(item, struct usb_os_desc_ext_prop, item);
900 }
901 
902 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
903 {
904 	return sprintf(page, "%d", to_usb_os_desc_ext_prop(item)->type);
905 }
906 
907 static ssize_t ext_prop_type_store(struct config_item *item,
908 				   const char *page, size_t len)
909 {
910 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
911 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
912 	u8 type;
913 	int ret;
914 
915 	if (desc->opts_mutex)
916 		mutex_lock(desc->opts_mutex);
917 	ret = kstrtou8(page, 0, &type);
918 	if (ret)
919 		goto end;
920 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
921 		ret = -EINVAL;
922 		goto end;
923 	}
924 
925 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
926 	    ext_prop->type == USB_EXT_PROP_LE32 ||
927 	    ext_prop->type == USB_EXT_PROP_BE32) &&
928 	    (type == USB_EXT_PROP_UNICODE ||
929 	    type == USB_EXT_PROP_UNICODE_ENV ||
930 	    type == USB_EXT_PROP_UNICODE_LINK))
931 		ext_prop->data_len <<= 1;
932 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
933 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
934 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
935 		   (type == USB_EXT_PROP_BINARY ||
936 		   type == USB_EXT_PROP_LE32 ||
937 		   type == USB_EXT_PROP_BE32))
938 		ext_prop->data_len >>= 1;
939 	ext_prop->type = type;
940 	ret = len;
941 
942 end:
943 	if (desc->opts_mutex)
944 		mutex_unlock(desc->opts_mutex);
945 	return ret;
946 }
947 
948 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
949 {
950 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
951 	int len = ext_prop->data_len;
952 
953 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
954 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
955 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
956 		len >>= 1;
957 	memcpy(page, ext_prop->data, len);
958 
959 	return len;
960 }
961 
962 static ssize_t ext_prop_data_store(struct config_item *item,
963 				   const char *page, size_t len)
964 {
965 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
966 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
967 	char *new_data;
968 	size_t ret_len = len;
969 
970 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
971 		--len;
972 	new_data = kmemdup(page, len, GFP_KERNEL);
973 	if (!new_data)
974 		return -ENOMEM;
975 
976 	if (desc->opts_mutex)
977 		mutex_lock(desc->opts_mutex);
978 	kfree(ext_prop->data);
979 	ext_prop->data = new_data;
980 	desc->ext_prop_len -= ext_prop->data_len;
981 	ext_prop->data_len = len;
982 	desc->ext_prop_len += ext_prop->data_len;
983 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
984 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
985 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
986 		desc->ext_prop_len -= ext_prop->data_len;
987 		ext_prop->data_len <<= 1;
988 		ext_prop->data_len += 2;
989 		desc->ext_prop_len += ext_prop->data_len;
990 	}
991 	if (desc->opts_mutex)
992 		mutex_unlock(desc->opts_mutex);
993 	return ret_len;
994 }
995 
996 CONFIGFS_ATTR(ext_prop_, type);
997 CONFIGFS_ATTR(ext_prop_, data);
998 
999 static struct configfs_attribute *ext_prop_attrs[] = {
1000 	&ext_prop_attr_type,
1001 	&ext_prop_attr_data,
1002 	NULL,
1003 };
1004 
1005 static void usb_os_desc_ext_prop_release(struct config_item *item)
1006 {
1007 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1008 
1009 	kfree(ext_prop); /* frees a whole chunk */
1010 }
1011 
1012 static struct configfs_item_operations ext_prop_ops = {
1013 	.release		= usb_os_desc_ext_prop_release,
1014 };
1015 
1016 static struct config_item *ext_prop_make(
1017 		struct config_group *group,
1018 		const char *name)
1019 {
1020 	struct usb_os_desc_ext_prop *ext_prop;
1021 	struct config_item_type *ext_prop_type;
1022 	struct usb_os_desc *desc;
1023 	char *vlabuf;
1024 
1025 	vla_group(data_chunk);
1026 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1027 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1028 
1029 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1030 	if (!vlabuf)
1031 		return ERR_PTR(-ENOMEM);
1032 
1033 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1034 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1035 
1036 	desc = container_of(group, struct usb_os_desc, group);
1037 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1038 	ext_prop_type->ct_attrs = ext_prop_attrs;
1039 	ext_prop_type->ct_owner = desc->owner;
1040 
1041 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1042 
1043 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1044 	if (!ext_prop->name) {
1045 		kfree(vlabuf);
1046 		return ERR_PTR(-ENOMEM);
1047 	}
1048 	desc->ext_prop_len += 14;
1049 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1050 	if (desc->opts_mutex)
1051 		mutex_lock(desc->opts_mutex);
1052 	desc->ext_prop_len += ext_prop->name_len;
1053 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1054 	++desc->ext_prop_count;
1055 	if (desc->opts_mutex)
1056 		mutex_unlock(desc->opts_mutex);
1057 
1058 	return &ext_prop->item;
1059 }
1060 
1061 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1062 {
1063 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1064 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1065 
1066 	if (desc->opts_mutex)
1067 		mutex_lock(desc->opts_mutex);
1068 	list_del(&ext_prop->entry);
1069 	--desc->ext_prop_count;
1070 	kfree(ext_prop->name);
1071 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1072 	if (desc->opts_mutex)
1073 		mutex_unlock(desc->opts_mutex);
1074 	config_item_put(item);
1075 }
1076 
1077 static struct configfs_group_operations interf_grp_ops = {
1078 	.make_item	= &ext_prop_make,
1079 	.drop_item	= &ext_prop_drop,
1080 };
1081 
1082 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1083 					     char *page)
1084 {
1085 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1086 	return 8;
1087 }
1088 
1089 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1090 					      const char *page, size_t len)
1091 {
1092 	struct usb_os_desc *desc = to_usb_os_desc(item);
1093 	int l;
1094 
1095 	l = min_t(int, 8, len);
1096 	if (page[l - 1] == '\n')
1097 		--l;
1098 	if (desc->opts_mutex)
1099 		mutex_lock(desc->opts_mutex);
1100 	memcpy(desc->ext_compat_id, page, l);
1101 
1102 	if (desc->opts_mutex)
1103 		mutex_unlock(desc->opts_mutex);
1104 
1105 	return len;
1106 }
1107 
1108 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1109 						 char *page)
1110 {
1111 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1112 	return 8;
1113 }
1114 
1115 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1116 						  const char *page, size_t len)
1117 {
1118 	struct usb_os_desc *desc = to_usb_os_desc(item);
1119 	int l;
1120 
1121 	l = min_t(int, 8, len);
1122 	if (page[l - 1] == '\n')
1123 		--l;
1124 	if (desc->opts_mutex)
1125 		mutex_lock(desc->opts_mutex);
1126 	memcpy(desc->ext_compat_id + 8, page, l);
1127 
1128 	if (desc->opts_mutex)
1129 		mutex_unlock(desc->opts_mutex);
1130 
1131 	return len;
1132 }
1133 
1134 CONFIGFS_ATTR(interf_grp_, compatible_id);
1135 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1136 
1137 static struct configfs_attribute *interf_grp_attrs[] = {
1138 	&interf_grp_attr_compatible_id,
1139 	&interf_grp_attr_sub_compatible_id,
1140 	NULL
1141 };
1142 
1143 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1144 				   int n_interf,
1145 				   struct usb_os_desc **desc,
1146 				   char **names,
1147 				   struct module *owner)
1148 {
1149 	struct config_group **f_default_groups, *os_desc_group,
1150 				**interface_groups;
1151 	struct config_item_type *os_desc_type, *interface_type;
1152 
1153 	vla_group(data_chunk);
1154 	vla_item(data_chunk, struct config_group *, f_default_groups, 2);
1155 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1156 	vla_item(data_chunk, struct config_group *, interface_groups,
1157 		 n_interf + 1);
1158 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1159 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1160 
1161 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1162 	if (!vlabuf)
1163 		return -ENOMEM;
1164 
1165 	f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
1166 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1167 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1168 	interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
1169 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1170 
1171 	parent->default_groups = f_default_groups;
1172 	os_desc_type->ct_owner = owner;
1173 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1174 	f_default_groups[0] = os_desc_group;
1175 
1176 	os_desc_group->default_groups = interface_groups;
1177 	interface_type->ct_group_ops = &interf_grp_ops;
1178 	interface_type->ct_attrs = interf_grp_attrs;
1179 	interface_type->ct_owner = owner;
1180 
1181 	while (n_interf--) {
1182 		struct usb_os_desc *d;
1183 
1184 		d = desc[n_interf];
1185 		d->owner = owner;
1186 		config_group_init_type_name(&d->group, "", interface_type);
1187 		config_item_set_name(&d->group.cg_item, "interface.%s",
1188 				     names[n_interf]);
1189 		interface_groups[n_interf] = &d->group;
1190 	}
1191 
1192 	return 0;
1193 }
1194 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1195 
1196 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1197 {
1198 	WARN_ON(1);
1199 	return -EINVAL;
1200 }
1201 
1202 int composite_dev_prepare(struct usb_composite_driver *composite,
1203 		struct usb_composite_dev *dev);
1204 
1205 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1206 				  struct usb_ep *ep0);
1207 
1208 static void purge_configs_funcs(struct gadget_info *gi)
1209 {
1210 	struct usb_configuration	*c;
1211 
1212 	list_for_each_entry(c, &gi->cdev.configs, list) {
1213 		struct usb_function *f, *tmp;
1214 		struct config_usb_cfg *cfg;
1215 
1216 		cfg = container_of(c, struct config_usb_cfg, c);
1217 
1218 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1219 
1220 			list_move_tail(&f->list, &cfg->func_list);
1221 			if (f->unbind) {
1222 				dev_err(&gi->cdev.gadget->dev, "unbind function"
1223 						" '%s'/%p\n", f->name, f);
1224 				f->unbind(c, f);
1225 			}
1226 		}
1227 		c->next_interface_id = 0;
1228 		memset(c->interface, 0, sizeof(c->interface));
1229 		c->superspeed = 0;
1230 		c->highspeed = 0;
1231 		c->fullspeed = 0;
1232 	}
1233 }
1234 
1235 static int configfs_composite_bind(struct usb_gadget *gadget,
1236 		struct usb_gadget_driver *gdriver)
1237 {
1238 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1239 	struct gadget_info		*gi = container_of(composite,
1240 						struct gadget_info, composite);
1241 	struct usb_composite_dev	*cdev = &gi->cdev;
1242 	struct usb_configuration	*c;
1243 	struct usb_string		*s;
1244 	unsigned			i;
1245 	int				ret;
1246 
1247 	/* the gi->lock is hold by the caller */
1248 	cdev->gadget = gadget;
1249 	set_gadget_data(gadget, cdev);
1250 	ret = composite_dev_prepare(composite, cdev);
1251 	if (ret)
1252 		return ret;
1253 	/* and now the gadget bind */
1254 	ret = -EINVAL;
1255 
1256 	if (list_empty(&gi->cdev.configs)) {
1257 		pr_err("Need at least one configuration in %s.\n",
1258 				gi->composite.name);
1259 		goto err_comp_cleanup;
1260 	}
1261 
1262 
1263 	list_for_each_entry(c, &gi->cdev.configs, list) {
1264 		struct config_usb_cfg *cfg;
1265 
1266 		cfg = container_of(c, struct config_usb_cfg, c);
1267 		if (list_empty(&cfg->func_list)) {
1268 			pr_err("Config %s/%d of %s needs at least one function.\n",
1269 			      c->label, c->bConfigurationValue,
1270 			      gi->composite.name);
1271 			goto err_comp_cleanup;
1272 		}
1273 	}
1274 
1275 	/* init all strings */
1276 	if (!list_empty(&gi->string_list)) {
1277 		struct gadget_strings *gs;
1278 
1279 		i = 0;
1280 		list_for_each_entry(gs, &gi->string_list, list) {
1281 
1282 			gi->gstrings[i] = &gs->stringtab_dev;
1283 			gs->stringtab_dev.strings = gs->strings;
1284 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1285 				gs->manufacturer;
1286 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1287 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1288 			i++;
1289 		}
1290 		gi->gstrings[i] = NULL;
1291 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1292 				USB_GADGET_FIRST_AVAIL_IDX);
1293 		if (IS_ERR(s)) {
1294 			ret = PTR_ERR(s);
1295 			goto err_comp_cleanup;
1296 		}
1297 
1298 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1299 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1300 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1301 	}
1302 
1303 	if (gi->use_os_desc) {
1304 		cdev->use_os_string = true;
1305 		cdev->b_vendor_code = gi->b_vendor_code;
1306 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1307 	}
1308 
1309 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1310 		struct usb_descriptor_header *usb_desc;
1311 
1312 		usb_desc = usb_otg_descriptor_alloc(gadget);
1313 		if (!usb_desc) {
1314 			ret = -ENOMEM;
1315 			goto err_comp_cleanup;
1316 		}
1317 		usb_otg_descriptor_init(gadget, usb_desc);
1318 		otg_desc[0] = usb_desc;
1319 		otg_desc[1] = NULL;
1320 	}
1321 
1322 	/* Go through all configs, attach all functions */
1323 	list_for_each_entry(c, &gi->cdev.configs, list) {
1324 		struct config_usb_cfg *cfg;
1325 		struct usb_function *f;
1326 		struct usb_function *tmp;
1327 		struct gadget_config_name *cn;
1328 
1329 		if (gadget_is_otg(gadget))
1330 			c->descriptors = otg_desc;
1331 
1332 		cfg = container_of(c, struct config_usb_cfg, c);
1333 		if (!list_empty(&cfg->string_list)) {
1334 			i = 0;
1335 			list_for_each_entry(cn, &cfg->string_list, list) {
1336 				cfg->gstrings[i] = &cn->stringtab_dev;
1337 				cn->stringtab_dev.strings = &cn->strings;
1338 				cn->strings.s = cn->configuration;
1339 				i++;
1340 			}
1341 			cfg->gstrings[i] = NULL;
1342 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1343 			if (IS_ERR(s)) {
1344 				ret = PTR_ERR(s);
1345 				goto err_comp_cleanup;
1346 			}
1347 			c->iConfiguration = s[0].id;
1348 		}
1349 
1350 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1351 			list_del(&f->list);
1352 			ret = usb_add_function(c, f);
1353 			if (ret) {
1354 				list_add(&f->list, &cfg->func_list);
1355 				goto err_purge_funcs;
1356 			}
1357 		}
1358 		usb_ep_autoconfig_reset(cdev->gadget);
1359 	}
1360 	if (cdev->use_os_string) {
1361 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1362 		if (ret)
1363 			goto err_purge_funcs;
1364 	}
1365 
1366 	usb_ep_autoconfig_reset(cdev->gadget);
1367 	return 0;
1368 
1369 err_purge_funcs:
1370 	purge_configs_funcs(gi);
1371 err_comp_cleanup:
1372 	composite_dev_cleanup(cdev);
1373 	return ret;
1374 }
1375 
1376 static void configfs_composite_unbind(struct usb_gadget *gadget)
1377 {
1378 	struct usb_composite_dev	*cdev;
1379 	struct gadget_info		*gi;
1380 
1381 	/* the gi->lock is hold by the caller */
1382 
1383 	cdev = get_gadget_data(gadget);
1384 	gi = container_of(cdev, struct gadget_info, cdev);
1385 
1386 	kfree(otg_desc[0]);
1387 	otg_desc[0] = NULL;
1388 	purge_configs_funcs(gi);
1389 	composite_dev_cleanup(cdev);
1390 	usb_ep_autoconfig_reset(cdev->gadget);
1391 	cdev->gadget = NULL;
1392 	set_gadget_data(gadget, NULL);
1393 }
1394 
1395 static const struct usb_gadget_driver configfs_driver_template = {
1396 	.bind           = configfs_composite_bind,
1397 	.unbind         = configfs_composite_unbind,
1398 
1399 	.setup          = composite_setup,
1400 	.reset          = composite_disconnect,
1401 	.disconnect     = composite_disconnect,
1402 
1403 	.suspend	= composite_suspend,
1404 	.resume		= composite_resume,
1405 
1406 	.max_speed	= USB_SPEED_SUPER,
1407 	.driver = {
1408 		.owner          = THIS_MODULE,
1409 		.name		= "configfs-gadget",
1410 	},
1411 };
1412 
1413 static struct config_group *gadgets_make(
1414 		struct config_group *group,
1415 		const char *name)
1416 {
1417 	struct gadget_info *gi;
1418 
1419 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1420 	if (!gi)
1421 		return ERR_PTR(-ENOMEM);
1422 
1423 	gi->group.default_groups = gi->default_groups;
1424 	gi->group.default_groups[0] = &gi->functions_group;
1425 	gi->group.default_groups[1] = &gi->configs_group;
1426 	gi->group.default_groups[2] = &gi->strings_group;
1427 	gi->group.default_groups[3] = &gi->os_desc_group;
1428 
1429 	config_group_init_type_name(&gi->functions_group, "functions",
1430 			&functions_type);
1431 	config_group_init_type_name(&gi->configs_group, "configs",
1432 			&config_desc_type);
1433 	config_group_init_type_name(&gi->strings_group, "strings",
1434 			&gadget_strings_strings_type);
1435 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1436 			&os_desc_type);
1437 
1438 	gi->composite.bind = configfs_do_nothing;
1439 	gi->composite.unbind = configfs_do_nothing;
1440 	gi->composite.suspend = NULL;
1441 	gi->composite.resume = NULL;
1442 	gi->composite.max_speed = USB_SPEED_SUPER;
1443 
1444 	mutex_init(&gi->lock);
1445 	INIT_LIST_HEAD(&gi->string_list);
1446 	INIT_LIST_HEAD(&gi->available_func);
1447 
1448 	composite_init_dev(&gi->cdev);
1449 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1450 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1451 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1452 
1453 	gi->composite.gadget_driver = configfs_driver_template;
1454 
1455 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1456 	gi->composite.name = gi->composite.gadget_driver.function;
1457 
1458 	if (!gi->composite.gadget_driver.function)
1459 		goto err;
1460 
1461 	config_group_init_type_name(&gi->group, name,
1462 				&gadget_root_type);
1463 	return &gi->group;
1464 err:
1465 	kfree(gi);
1466 	return ERR_PTR(-ENOMEM);
1467 }
1468 
1469 static void gadgets_drop(struct config_group *group, struct config_item *item)
1470 {
1471 	config_item_put(item);
1472 }
1473 
1474 static struct configfs_group_operations gadgets_ops = {
1475 	.make_group     = &gadgets_make,
1476 	.drop_item      = &gadgets_drop,
1477 };
1478 
1479 static struct config_item_type gadgets_type = {
1480 	.ct_group_ops   = &gadgets_ops,
1481 	.ct_owner       = THIS_MODULE,
1482 };
1483 
1484 static struct configfs_subsystem gadget_subsys = {
1485 	.su_group = {
1486 		.cg_item = {
1487 			.ci_namebuf = "usb_gadget",
1488 			.ci_type = &gadgets_type,
1489 		},
1490 	},
1491 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1492 };
1493 
1494 void unregister_gadget_item(struct config_item *item)
1495 {
1496 	struct gadget_info *gi = to_gadget_info(item);
1497 
1498 	unregister_gadget(gi);
1499 }
1500 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1501 
1502 static int __init gadget_cfs_init(void)
1503 {
1504 	int ret;
1505 
1506 	config_group_init(&gadget_subsys.su_group);
1507 
1508 	ret = configfs_register_subsystem(&gadget_subsys);
1509 	return ret;
1510 }
1511 module_init(gadget_cfs_init);
1512 
1513 static void __exit gadget_cfs_exit(void)
1514 {
1515 	configfs_unregister_subsystem(&gadget_subsys);
1516 }
1517 module_exit(gadget_cfs_exit);
1518