xref: /linux/drivers/usb/gadget/configfs.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 struct config_usb_cfg {
68 	struct config_group group;
69 	struct config_group strings_group;
70 	struct config_group *default_groups[2];
71 	struct list_head string_list;
72 	struct usb_configuration c;
73 	struct list_head func_list;
74 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
75 };
76 
77 struct gadget_strings {
78 	struct usb_gadget_strings stringtab_dev;
79 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
80 	char *manufacturer;
81 	char *product;
82 	char *serialnumber;
83 
84 	struct config_group group;
85 	struct list_head list;
86 };
87 
88 struct os_desc {
89 	struct config_group group;
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 static int usb_string_copy(const char *s, char **s_copy)
102 {
103 	int ret;
104 	char *str;
105 	char *copy = *s_copy;
106 	ret = strlen(s);
107 	if (ret > 126)
108 		return -EOVERFLOW;
109 
110 	str = kstrdup(s, GFP_KERNEL);
111 	if (!str)
112 		return -ENOMEM;
113 	if (str[ret - 1] == '\n')
114 		str[ret - 1] = '\0';
115 	kfree(copy);
116 	*s_copy = str;
117 	return 0;
118 }
119 
120 CONFIGFS_ATTR_STRUCT(gadget_info);
121 CONFIGFS_ATTR_STRUCT(config_usb_cfg);
122 
123 #define GI_DEVICE_DESC_ITEM_ATTR(name)	\
124 	static struct gadget_info_attribute gadget_cdev_desc_##name = \
125 		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
126 				gadget_dev_desc_##name##_show,		\
127 				gadget_dev_desc_##name##_store)
128 
129 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
130 	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
131 			char *page)	\
132 {	\
133 	return sprintf(page, "0x%02x\n", gi->cdev.desc.__name);	\
134 }
135 
136 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
137 	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
138 			char *page)	\
139 {	\
140 	return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
141 }
142 
143 
144 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
145 	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
146 		const char *page, size_t len)		\
147 {							\
148 	u8 val;						\
149 	int ret;					\
150 	ret = kstrtou8(page, 0, &val);			\
151 	if (ret)					\
152 		return ret;				\
153 	gi->cdev.desc._name = val;			\
154 	return len;					\
155 }
156 
157 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
158 	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
159 		const char *page, size_t len)		\
160 {							\
161 	u16 val;					\
162 	int ret;					\
163 	ret = kstrtou16(page, 0, &val);			\
164 	if (ret)					\
165 		return ret;				\
166 	gi->cdev.desc._name = cpu_to_le16p(&val);	\
167 	return len;					\
168 }
169 
170 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
171 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
172 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
173 
174 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
175 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
176 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
177 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
178 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
179 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
180 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
181 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
182 
183 static ssize_t is_valid_bcd(u16 bcd_val)
184 {
185 	if ((bcd_val & 0xf) > 9)
186 		return -EINVAL;
187 	if (((bcd_val >> 4) & 0xf) > 9)
188 		return -EINVAL;
189 	if (((bcd_val >> 8) & 0xf) > 9)
190 		return -EINVAL;
191 	if (((bcd_val >> 12) & 0xf) > 9)
192 		return -EINVAL;
193 	return 0;
194 }
195 
196 static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
197 		const char *page, size_t len)
198 {
199 	u16 bcdDevice;
200 	int ret;
201 
202 	ret = kstrtou16(page, 0, &bcdDevice);
203 	if (ret)
204 		return ret;
205 	ret = is_valid_bcd(bcdDevice);
206 	if (ret)
207 		return ret;
208 
209 	gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
210 	return len;
211 }
212 
213 static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
214 		const char *page, size_t len)
215 {
216 	u16 bcdUSB;
217 	int ret;
218 
219 	ret = kstrtou16(page, 0, &bcdUSB);
220 	if (ret)
221 		return ret;
222 	ret = is_valid_bcd(bcdUSB);
223 	if (ret)
224 		return ret;
225 
226 	gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
227 	return len;
228 }
229 
230 static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
231 {
232 	return sprintf(page, "%s\n", gi->udc_name ?: "");
233 }
234 
235 static int unregister_gadget(struct gadget_info *gi)
236 {
237 	int ret;
238 
239 	if (!gi->udc_name)
240 		return -ENODEV;
241 
242 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
243 	if (ret)
244 		return ret;
245 	kfree(gi->udc_name);
246 	gi->udc_name = NULL;
247 	return 0;
248 }
249 
250 static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
251 		const char *page, size_t len)
252 {
253 	char *name;
254 	int ret;
255 
256 	name = kstrdup(page, GFP_KERNEL);
257 	if (!name)
258 		return -ENOMEM;
259 	if (name[len - 1] == '\n')
260 		name[len - 1] = '\0';
261 
262 	mutex_lock(&gi->lock);
263 
264 	if (!strlen(name)) {
265 		ret = unregister_gadget(gi);
266 		if (ret)
267 			goto err;
268 	} else {
269 		if (gi->udc_name) {
270 			ret = -EBUSY;
271 			goto err;
272 		}
273 		ret = usb_udc_attach_driver(name, &gi->composite.gadget_driver);
274 		if (ret)
275 			goto err;
276 		gi->udc_name = name;
277 	}
278 	mutex_unlock(&gi->lock);
279 	return len;
280 err:
281 	kfree(name);
282 	mutex_unlock(&gi->lock);
283 	return ret;
284 }
285 
286 GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
287 GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
288 GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
289 GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
290 GI_DEVICE_DESC_ITEM_ATTR(idVendor);
291 GI_DEVICE_DESC_ITEM_ATTR(idProduct);
292 GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
293 GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
294 GI_DEVICE_DESC_ITEM_ATTR(UDC);
295 
296 static struct configfs_attribute *gadget_root_attrs[] = {
297 	&gadget_cdev_desc_bDeviceClass.attr,
298 	&gadget_cdev_desc_bDeviceSubClass.attr,
299 	&gadget_cdev_desc_bDeviceProtocol.attr,
300 	&gadget_cdev_desc_bMaxPacketSize0.attr,
301 	&gadget_cdev_desc_idVendor.attr,
302 	&gadget_cdev_desc_idProduct.attr,
303 	&gadget_cdev_desc_bcdDevice.attr,
304 	&gadget_cdev_desc_bcdUSB.attr,
305 	&gadget_cdev_desc_UDC.attr,
306 	NULL,
307 };
308 
309 static inline struct gadget_info *to_gadget_info(struct config_item *item)
310 {
311 	 return container_of(to_config_group(item), struct gadget_info, group);
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 config_usb_cfg *to_config_usb_cfg(struct config_item *item)
328 {
329 	return container_of(to_config_group(item), struct config_usb_cfg,
330 			group);
331 }
332 
333 static inline struct usb_function_instance *to_usb_function_instance(
334 		struct config_item *item)
335 {
336 	 return container_of(to_config_group(item),
337 			 struct usb_function_instance, group);
338 }
339 
340 static void gadget_info_attr_release(struct config_item *item)
341 {
342 	struct gadget_info *gi = to_gadget_info(item);
343 
344 	WARN_ON(!list_empty(&gi->cdev.configs));
345 	WARN_ON(!list_empty(&gi->string_list));
346 	WARN_ON(!list_empty(&gi->available_func));
347 	kfree(gi->composite.gadget_driver.function);
348 	kfree(gi);
349 }
350 
351 CONFIGFS_ATTR_OPS(gadget_info);
352 
353 static struct configfs_item_operations gadget_root_item_ops = {
354 	.release                = gadget_info_attr_release,
355 	.show_attribute         = gadget_info_attr_show,
356 	.store_attribute        = gadget_info_attr_store,
357 };
358 
359 static void gadget_config_attr_release(struct config_item *item)
360 {
361 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
362 
363 	WARN_ON(!list_empty(&cfg->c.functions));
364 	list_del(&cfg->c.list);
365 	kfree(cfg->c.label);
366 	kfree(cfg);
367 }
368 
369 static int config_usb_cfg_link(
370 	struct config_item *usb_cfg_ci,
371 	struct config_item *usb_func_ci)
372 {
373 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
374 	struct usb_composite_dev *cdev = cfg->c.cdev;
375 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
376 
377 	struct config_group *group = to_config_group(usb_func_ci);
378 	struct usb_function_instance *fi = container_of(group,
379 			struct usb_function_instance, group);
380 	struct usb_function_instance *a_fi;
381 	struct usb_function *f;
382 	int ret;
383 
384 	mutex_lock(&gi->lock);
385 	/*
386 	 * Make sure this function is from within our _this_ gadget and not
387 	 * from another gadget or a random directory.
388 	 * Also a function instance can only be linked once.
389 	 */
390 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
391 		if (a_fi == fi)
392 			break;
393 	}
394 	if (a_fi != fi) {
395 		ret = -EINVAL;
396 		goto out;
397 	}
398 
399 	list_for_each_entry(f, &cfg->func_list, list) {
400 		if (f->fi == fi) {
401 			ret = -EEXIST;
402 			goto out;
403 		}
404 	}
405 
406 	f = usb_get_function(fi);
407 	if (IS_ERR(f)) {
408 		ret = PTR_ERR(f);
409 		goto out;
410 	}
411 
412 	/* stash the function until we bind it to the gadget */
413 	list_add_tail(&f->list, &cfg->func_list);
414 	ret = 0;
415 out:
416 	mutex_unlock(&gi->lock);
417 	return ret;
418 }
419 
420 static int config_usb_cfg_unlink(
421 	struct config_item *usb_cfg_ci,
422 	struct config_item *usb_func_ci)
423 {
424 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
425 	struct usb_composite_dev *cdev = cfg->c.cdev;
426 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
427 
428 	struct config_group *group = to_config_group(usb_func_ci);
429 	struct usb_function_instance *fi = container_of(group,
430 			struct usb_function_instance, group);
431 	struct usb_function *f;
432 
433 	/*
434 	 * ideally I would like to forbid to unlink functions while a gadget is
435 	 * bound to an UDC. Since this isn't possible at the moment, we simply
436 	 * force an unbind, the function is available here and then we can
437 	 * remove the function.
438 	 */
439 	mutex_lock(&gi->lock);
440 	if (gi->udc_name)
441 		unregister_gadget(gi);
442 	WARN_ON(gi->udc_name);
443 
444 	list_for_each_entry(f, &cfg->func_list, list) {
445 		if (f->fi == fi) {
446 			list_del(&f->list);
447 			usb_put_function(f);
448 			mutex_unlock(&gi->lock);
449 			return 0;
450 		}
451 	}
452 	mutex_unlock(&gi->lock);
453 	WARN(1, "Unable to locate function to unbind\n");
454 	return 0;
455 }
456 
457 CONFIGFS_ATTR_OPS(config_usb_cfg);
458 
459 static struct configfs_item_operations gadget_config_item_ops = {
460 	.release                = gadget_config_attr_release,
461 	.show_attribute         = config_usb_cfg_attr_show,
462 	.store_attribute        = config_usb_cfg_attr_store,
463 	.allow_link             = config_usb_cfg_link,
464 	.drop_link              = config_usb_cfg_unlink,
465 };
466 
467 
468 static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
469 		char *page)
470 {
471 	return sprintf(page, "%u\n", cfg->c.MaxPower);
472 }
473 
474 static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
475 		const char *page, size_t len)
476 {
477 	u16 val;
478 	int ret;
479 	ret = kstrtou16(page, 0, &val);
480 	if (ret)
481 		return ret;
482 	if (DIV_ROUND_UP(val, 8) > 0xff)
483 		return -ERANGE;
484 	cfg->c.MaxPower = val;
485 	return len;
486 }
487 
488 static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
489 		char *page)
490 {
491 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
492 }
493 
494 static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
495 		const char *page, size_t len)
496 {
497 	u8 val;
498 	int ret;
499 	ret = kstrtou8(page, 0, &val);
500 	if (ret)
501 		return ret;
502 	if (!(val & USB_CONFIG_ATT_ONE))
503 		return -EINVAL;
504 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
505 				USB_CONFIG_ATT_WAKEUP))
506 		return -EINVAL;
507 	cfg->c.bmAttributes = val;
508 	return len;
509 }
510 
511 #define CFG_CONFIG_DESC_ITEM_ATTR(name)	\
512 	static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
513 		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
514 				gadget_config_desc_##name##_show,	\
515 				gadget_config_desc_##name##_store)
516 
517 CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
518 CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
519 
520 static struct configfs_attribute *gadget_config_attrs[] = {
521 	&gadget_usb_cfg_MaxPower.attr,
522 	&gadget_usb_cfg_bmAttributes.attr,
523 	NULL,
524 };
525 
526 static struct config_item_type gadget_config_type = {
527 	.ct_item_ops	= &gadget_config_item_ops,
528 	.ct_attrs	= gadget_config_attrs,
529 	.ct_owner	= THIS_MODULE,
530 };
531 
532 static struct config_item_type gadget_root_type = {
533 	.ct_item_ops	= &gadget_root_item_ops,
534 	.ct_attrs	= gadget_root_attrs,
535 	.ct_owner	= THIS_MODULE,
536 };
537 
538 static void composite_init_dev(struct usb_composite_dev *cdev)
539 {
540 	spin_lock_init(&cdev->lock);
541 	INIT_LIST_HEAD(&cdev->configs);
542 	INIT_LIST_HEAD(&cdev->gstrings);
543 }
544 
545 static struct config_group *function_make(
546 		struct config_group *group,
547 		const char *name)
548 {
549 	struct gadget_info *gi;
550 	struct usb_function_instance *fi;
551 	char buf[MAX_NAME_LEN];
552 	char *func_name;
553 	char *instance_name;
554 	int ret;
555 
556 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
557 	if (ret >= MAX_NAME_LEN)
558 		return ERR_PTR(-ENAMETOOLONG);
559 
560 	func_name = buf;
561 	instance_name = strchr(func_name, '.');
562 	if (!instance_name) {
563 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
564 		return ERR_PTR(-EINVAL);
565 	}
566 	*instance_name = '\0';
567 	instance_name++;
568 
569 	fi = usb_get_function_instance(func_name);
570 	if (IS_ERR(fi))
571 		return ERR_CAST(fi);
572 
573 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
574 	if (ret) {
575 		usb_put_function_instance(fi);
576 		return ERR_PTR(ret);
577 	}
578 	if (fi->set_inst_name) {
579 		ret = fi->set_inst_name(fi, instance_name);
580 		if (ret) {
581 			usb_put_function_instance(fi);
582 			return ERR_PTR(ret);
583 		}
584 	}
585 
586 	gi = container_of(group, struct gadget_info, functions_group);
587 
588 	mutex_lock(&gi->lock);
589 	list_add_tail(&fi->cfs_list, &gi->available_func);
590 	mutex_unlock(&gi->lock);
591 	return &fi->group;
592 }
593 
594 static void function_drop(
595 		struct config_group *group,
596 		struct config_item *item)
597 {
598 	struct usb_function_instance *fi = to_usb_function_instance(item);
599 	struct gadget_info *gi;
600 
601 	gi = container_of(group, struct gadget_info, functions_group);
602 
603 	mutex_lock(&gi->lock);
604 	list_del(&fi->cfs_list);
605 	mutex_unlock(&gi->lock);
606 	config_item_put(item);
607 }
608 
609 static struct configfs_group_operations functions_ops = {
610 	.make_group     = &function_make,
611 	.drop_item      = &function_drop,
612 };
613 
614 static struct config_item_type functions_type = {
615 	.ct_group_ops   = &functions_ops,
616 	.ct_owner       = THIS_MODULE,
617 };
618 
619 CONFIGFS_ATTR_STRUCT(gadget_config_name);
620 GS_STRINGS_RW(gadget_config_name, configuration);
621 
622 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
623 	&gadget_config_name_configuration.attr,
624 	NULL,
625 };
626 
627 static void gadget_config_name_attr_release(struct config_item *item)
628 {
629 	struct gadget_config_name *cn = to_gadget_config_name(item);
630 
631 	kfree(cn->configuration);
632 
633 	list_del(&cn->list);
634 	kfree(cn);
635 }
636 
637 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
638 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
639 
640 static struct config_group *config_desc_make(
641 		struct config_group *group,
642 		const char *name)
643 {
644 	struct gadget_info *gi;
645 	struct config_usb_cfg *cfg;
646 	char buf[MAX_NAME_LEN];
647 	char *num_str;
648 	u8 num;
649 	int ret;
650 
651 	gi = container_of(group, struct gadget_info, configs_group);
652 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
653 	if (ret >= MAX_NAME_LEN)
654 		return ERR_PTR(-ENAMETOOLONG);
655 
656 	num_str = strchr(buf, '.');
657 	if (!num_str) {
658 		pr_err("Unable to locate . in name.bConfigurationValue\n");
659 		return ERR_PTR(-EINVAL);
660 	}
661 
662 	*num_str = '\0';
663 	num_str++;
664 
665 	if (!strlen(buf))
666 		return ERR_PTR(-EINVAL);
667 
668 	ret = kstrtou8(num_str, 0, &num);
669 	if (ret)
670 		return ERR_PTR(ret);
671 
672 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
673 	if (!cfg)
674 		return ERR_PTR(-ENOMEM);
675 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
676 	if (!cfg->c.label) {
677 		ret = -ENOMEM;
678 		goto err;
679 	}
680 	cfg->c.bConfigurationValue = num;
681 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
682 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
683 	INIT_LIST_HEAD(&cfg->string_list);
684 	INIT_LIST_HEAD(&cfg->func_list);
685 
686 	cfg->group.default_groups = cfg->default_groups;
687 	cfg->default_groups[0] = &cfg->strings_group;
688 
689 	config_group_init_type_name(&cfg->group, name,
690 				&gadget_config_type);
691 	config_group_init_type_name(&cfg->strings_group, "strings",
692 			&gadget_config_name_strings_type);
693 
694 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
695 	if (ret)
696 		goto err;
697 
698 	return &cfg->group;
699 err:
700 	kfree(cfg->c.label);
701 	kfree(cfg);
702 	return ERR_PTR(ret);
703 }
704 
705 static void config_desc_drop(
706 		struct config_group *group,
707 		struct config_item *item)
708 {
709 	config_item_put(item);
710 }
711 
712 static struct configfs_group_operations config_desc_ops = {
713 	.make_group     = &config_desc_make,
714 	.drop_item      = &config_desc_drop,
715 };
716 
717 static struct config_item_type config_desc_type = {
718 	.ct_group_ops   = &config_desc_ops,
719 	.ct_owner       = THIS_MODULE,
720 };
721 
722 CONFIGFS_ATTR_STRUCT(gadget_strings);
723 GS_STRINGS_RW(gadget_strings, manufacturer);
724 GS_STRINGS_RW(gadget_strings, product);
725 GS_STRINGS_RW(gadget_strings, serialnumber);
726 
727 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
728 	&gadget_strings_manufacturer.attr,
729 	&gadget_strings_product.attr,
730 	&gadget_strings_serialnumber.attr,
731 	NULL,
732 };
733 
734 static void gadget_strings_attr_release(struct config_item *item)
735 {
736 	struct gadget_strings *gs = to_gadget_strings(item);
737 
738 	kfree(gs->manufacturer);
739 	kfree(gs->product);
740 	kfree(gs->serialnumber);
741 
742 	list_del(&gs->list);
743 	kfree(gs);
744 }
745 
746 USB_CONFIG_STRING_RW_OPS(gadget_strings);
747 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
748 
749 static inline struct os_desc *to_os_desc(struct config_item *item)
750 {
751 	return container_of(to_config_group(item), struct os_desc, group);
752 }
753 
754 CONFIGFS_ATTR_STRUCT(os_desc);
755 CONFIGFS_ATTR_OPS(os_desc);
756 
757 static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
758 {
759 	struct gadget_info *gi;
760 
761 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
762 
763 	return sprintf(page, "%d", gi->use_os_desc);
764 }
765 
766 static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
767 				 size_t len)
768 {
769 	struct gadget_info *gi;
770 	int ret;
771 	bool use;
772 
773 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
774 
775 	mutex_lock(&gi->lock);
776 	ret = strtobool(page, &use);
777 	if (!ret) {
778 		gi->use_os_desc = use;
779 		ret = len;
780 	}
781 	mutex_unlock(&gi->lock);
782 
783 	return ret;
784 }
785 
786 static struct os_desc_attribute os_desc_use =
787 	__CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
788 			os_desc_use_show,
789 			os_desc_use_store);
790 
791 static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
792 {
793 	struct gadget_info *gi;
794 
795 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
796 
797 	return sprintf(page, "%d", gi->b_vendor_code);
798 }
799 
800 static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
801 					   const char *page, size_t len)
802 {
803 	struct gadget_info *gi;
804 	int ret;
805 	u8 b_vendor_code;
806 
807 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
808 
809 	mutex_lock(&gi->lock);
810 	ret = kstrtou8(page, 0, &b_vendor_code);
811 	if (!ret) {
812 		gi->b_vendor_code = b_vendor_code;
813 		ret = len;
814 	}
815 	mutex_unlock(&gi->lock);
816 
817 	return ret;
818 }
819 
820 static struct os_desc_attribute os_desc_b_vendor_code =
821 	__CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
822 			os_desc_b_vendor_code_show,
823 			os_desc_b_vendor_code_store);
824 
825 static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
826 {
827 	struct gadget_info *gi;
828 
829 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
830 
831 	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
832 
833 	return OS_STRING_QW_SIGN_LEN;
834 }
835 
836 static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
837 				     size_t len)
838 {
839 	struct gadget_info *gi;
840 	int res, l;
841 
842 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
843 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
844 	if (page[l - 1] == '\n')
845 		--l;
846 
847 	mutex_lock(&gi->lock);
848 	res = utf8s_to_utf16s(page, l,
849 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
850 			      OS_STRING_QW_SIGN_LEN);
851 	if (res > 0)
852 		res = len;
853 	mutex_unlock(&gi->lock);
854 
855 	return res;
856 }
857 
858 static struct os_desc_attribute os_desc_qw_sign =
859 	__CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
860 			os_desc_qw_sign_show,
861 			os_desc_qw_sign_store);
862 
863 static struct configfs_attribute *os_desc_attrs[] = {
864 	&os_desc_use.attr,
865 	&os_desc_b_vendor_code.attr,
866 	&os_desc_qw_sign.attr,
867 	NULL,
868 };
869 
870 static void os_desc_attr_release(struct config_item *item)
871 {
872 	struct os_desc *os_desc = to_os_desc(item);
873 	kfree(os_desc);
874 }
875 
876 static int os_desc_link(struct config_item *os_desc_ci,
877 			struct config_item *usb_cfg_ci)
878 {
879 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
880 					struct gadget_info, os_desc_group);
881 	struct usb_composite_dev *cdev = &gi->cdev;
882 	struct config_usb_cfg *c_target =
883 		container_of(to_config_group(usb_cfg_ci),
884 			     struct config_usb_cfg, group);
885 	struct usb_configuration *c;
886 	int ret;
887 
888 	mutex_lock(&gi->lock);
889 	list_for_each_entry(c, &cdev->configs, list) {
890 		if (c == &c_target->c)
891 			break;
892 	}
893 	if (c != &c_target->c) {
894 		ret = -EINVAL;
895 		goto out;
896 	}
897 
898 	if (cdev->os_desc_config) {
899 		ret = -EBUSY;
900 		goto out;
901 	}
902 
903 	cdev->os_desc_config = &c_target->c;
904 	ret = 0;
905 
906 out:
907 	mutex_unlock(&gi->lock);
908 	return ret;
909 }
910 
911 static int os_desc_unlink(struct config_item *os_desc_ci,
912 			  struct config_item *usb_cfg_ci)
913 {
914 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
915 					struct gadget_info, os_desc_group);
916 	struct usb_composite_dev *cdev = &gi->cdev;
917 
918 	mutex_lock(&gi->lock);
919 	if (gi->udc_name)
920 		unregister_gadget(gi);
921 	cdev->os_desc_config = NULL;
922 	WARN_ON(gi->udc_name);
923 	mutex_unlock(&gi->lock);
924 	return 0;
925 }
926 
927 static struct configfs_item_operations os_desc_ops = {
928 	.release                = os_desc_attr_release,
929 	.show_attribute         = os_desc_attr_show,
930 	.store_attribute        = os_desc_attr_store,
931 	.allow_link		= os_desc_link,
932 	.drop_link		= os_desc_unlink,
933 };
934 
935 static struct config_item_type os_desc_type = {
936 	.ct_item_ops	= &os_desc_ops,
937 	.ct_attrs	= os_desc_attrs,
938 	.ct_owner	= THIS_MODULE,
939 };
940 
941 CONFIGFS_ATTR_STRUCT(usb_os_desc);
942 CONFIGFS_ATTR_OPS(usb_os_desc);
943 
944 
945 static inline struct usb_os_desc_ext_prop
946 *to_usb_os_desc_ext_prop(struct config_item *item)
947 {
948 	return container_of(item, struct usb_os_desc_ext_prop, item);
949 }
950 
951 CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop);
952 CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop);
953 
954 static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop,
955 				  char *page)
956 {
957 	return sprintf(page, "%d", ext_prop->type);
958 }
959 
960 static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop,
961 				   const char *page, size_t len)
962 {
963 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
964 	u8 type;
965 	int ret;
966 
967 	if (desc->opts_mutex)
968 		mutex_lock(desc->opts_mutex);
969 	ret = kstrtou8(page, 0, &type);
970 	if (ret)
971 		goto end;
972 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
973 		ret = -EINVAL;
974 		goto end;
975 	}
976 
977 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
978 	    ext_prop->type == USB_EXT_PROP_LE32 ||
979 	    ext_prop->type == USB_EXT_PROP_BE32) &&
980 	    (type == USB_EXT_PROP_UNICODE ||
981 	    type == USB_EXT_PROP_UNICODE_ENV ||
982 	    type == USB_EXT_PROP_UNICODE_LINK))
983 		ext_prop->data_len <<= 1;
984 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
985 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
986 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
987 		   (type == USB_EXT_PROP_BINARY ||
988 		   type == USB_EXT_PROP_LE32 ||
989 		   type == USB_EXT_PROP_BE32))
990 		ext_prop->data_len >>= 1;
991 	ext_prop->type = type;
992 	ret = len;
993 
994 end:
995 	if (desc->opts_mutex)
996 		mutex_unlock(desc->opts_mutex);
997 	return ret;
998 }
999 
1000 static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
1001 				  char *page)
1002 {
1003 	int len = ext_prop->data_len;
1004 
1005 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1006 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1007 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1008 		len >>= 1;
1009 	memcpy(page, ext_prop->data, len);
1010 
1011 	return len;
1012 }
1013 
1014 static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
1015 				   const char *page, size_t len)
1016 {
1017 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1018 	char *new_data;
1019 	size_t ret_len = len;
1020 
1021 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1022 		--len;
1023 	new_data = kmemdup(page, len, GFP_KERNEL);
1024 	if (!new_data)
1025 		return -ENOMEM;
1026 
1027 	if (desc->opts_mutex)
1028 		mutex_lock(desc->opts_mutex);
1029 	kfree(ext_prop->data);
1030 	ext_prop->data = new_data;
1031 	desc->ext_prop_len -= ext_prop->data_len;
1032 	ext_prop->data_len = len;
1033 	desc->ext_prop_len += ext_prop->data_len;
1034 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1035 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1036 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1037 		desc->ext_prop_len -= ext_prop->data_len;
1038 		ext_prop->data_len <<= 1;
1039 		ext_prop->data_len += 2;
1040 		desc->ext_prop_len += ext_prop->data_len;
1041 	}
1042 	if (desc->opts_mutex)
1043 		mutex_unlock(desc->opts_mutex);
1044 	return ret_len;
1045 }
1046 
1047 static struct usb_os_desc_ext_prop_attribute ext_prop_type =
1048 	__CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR,
1049 			ext_prop_type_show, ext_prop_type_store);
1050 
1051 static struct usb_os_desc_ext_prop_attribute ext_prop_data =
1052 	__CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR,
1053 			ext_prop_data_show, ext_prop_data_store);
1054 
1055 static struct configfs_attribute *ext_prop_attrs[] = {
1056 	&ext_prop_type.attr,
1057 	&ext_prop_data.attr,
1058 	NULL,
1059 };
1060 
1061 static void usb_os_desc_ext_prop_release(struct config_item *item)
1062 {
1063 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1064 
1065 	kfree(ext_prop); /* frees a whole chunk */
1066 }
1067 
1068 static struct configfs_item_operations ext_prop_ops = {
1069 	.release		= usb_os_desc_ext_prop_release,
1070 	.show_attribute		= usb_os_desc_ext_prop_attr_show,
1071 	.store_attribute	= usb_os_desc_ext_prop_attr_store,
1072 };
1073 
1074 static struct config_item *ext_prop_make(
1075 		struct config_group *group,
1076 		const char *name)
1077 {
1078 	struct usb_os_desc_ext_prop *ext_prop;
1079 	struct config_item_type *ext_prop_type;
1080 	struct usb_os_desc *desc;
1081 	char *vlabuf;
1082 
1083 	vla_group(data_chunk);
1084 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1085 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1086 
1087 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1088 	if (!vlabuf)
1089 		return ERR_PTR(-ENOMEM);
1090 
1091 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1092 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1093 
1094 	desc = container_of(group, struct usb_os_desc, group);
1095 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1096 	ext_prop_type->ct_attrs = ext_prop_attrs;
1097 	ext_prop_type->ct_owner = desc->owner;
1098 
1099 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1100 
1101 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1102 	if (!ext_prop->name) {
1103 		kfree(vlabuf);
1104 		return ERR_PTR(-ENOMEM);
1105 	}
1106 	desc->ext_prop_len += 14;
1107 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1108 	if (desc->opts_mutex)
1109 		mutex_lock(desc->opts_mutex);
1110 	desc->ext_prop_len += ext_prop->name_len;
1111 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1112 	++desc->ext_prop_count;
1113 	if (desc->opts_mutex)
1114 		mutex_unlock(desc->opts_mutex);
1115 
1116 	return &ext_prop->item;
1117 }
1118 
1119 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1120 {
1121 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1122 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1123 
1124 	if (desc->opts_mutex)
1125 		mutex_lock(desc->opts_mutex);
1126 	list_del(&ext_prop->entry);
1127 	--desc->ext_prop_count;
1128 	kfree(ext_prop->name);
1129 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1130 	if (desc->opts_mutex)
1131 		mutex_unlock(desc->opts_mutex);
1132 	config_item_put(item);
1133 }
1134 
1135 static struct configfs_group_operations interf_grp_ops = {
1136 	.make_item	= &ext_prop_make,
1137 	.drop_item	= &ext_prop_drop,
1138 };
1139 
1140 static struct configfs_item_operations interf_item_ops = {
1141 	.show_attribute		= usb_os_desc_attr_show,
1142 	.store_attribute	= usb_os_desc_attr_store,
1143 };
1144 
1145 static ssize_t interf_grp_compatible_id_show(struct usb_os_desc *desc,
1146 					     char *page)
1147 {
1148 	memcpy(page, desc->ext_compat_id, 8);
1149 	return 8;
1150 }
1151 
1152 static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc,
1153 					      const char *page, size_t len)
1154 {
1155 	int l;
1156 
1157 	l = min_t(int, 8, len);
1158 	if (page[l - 1] == '\n')
1159 		--l;
1160 	if (desc->opts_mutex)
1161 		mutex_lock(desc->opts_mutex);
1162 	memcpy(desc->ext_compat_id, page, l);
1163 
1164 	if (desc->opts_mutex)
1165 		mutex_unlock(desc->opts_mutex);
1166 
1167 	return len;
1168 }
1169 
1170 static struct usb_os_desc_attribute interf_grp_attr_compatible_id =
1171 	__CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
1172 			interf_grp_compatible_id_show,
1173 			interf_grp_compatible_id_store);
1174 
1175 static ssize_t interf_grp_sub_compatible_id_show(struct usb_os_desc *desc,
1176 						 char *page)
1177 {
1178 	memcpy(page, desc->ext_compat_id + 8, 8);
1179 	return 8;
1180 }
1181 
1182 static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc,
1183 						  const char *page, size_t len)
1184 {
1185 	int l;
1186 
1187 	l = min_t(int, 8, len);
1188 	if (page[l - 1] == '\n')
1189 		--l;
1190 	if (desc->opts_mutex)
1191 		mutex_lock(desc->opts_mutex);
1192 	memcpy(desc->ext_compat_id + 8, page, l);
1193 
1194 	if (desc->opts_mutex)
1195 		mutex_unlock(desc->opts_mutex);
1196 
1197 	return len;
1198 }
1199 
1200 static struct usb_os_desc_attribute interf_grp_attr_sub_compatible_id =
1201 	__CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
1202 			interf_grp_sub_compatible_id_show,
1203 			interf_grp_sub_compatible_id_store);
1204 
1205 static struct configfs_attribute *interf_grp_attrs[] = {
1206 	&interf_grp_attr_compatible_id.attr,
1207 	&interf_grp_attr_sub_compatible_id.attr,
1208 	NULL
1209 };
1210 
1211 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1212 				   int n_interf,
1213 				   struct usb_os_desc **desc,
1214 				   char **names,
1215 				   struct module *owner)
1216 {
1217 	struct config_group **f_default_groups, *os_desc_group,
1218 				**interface_groups;
1219 	struct config_item_type *os_desc_type, *interface_type;
1220 
1221 	vla_group(data_chunk);
1222 	vla_item(data_chunk, struct config_group *, f_default_groups, 2);
1223 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1224 	vla_item(data_chunk, struct config_group *, interface_groups,
1225 		 n_interf + 1);
1226 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1227 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1228 
1229 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1230 	if (!vlabuf)
1231 		return -ENOMEM;
1232 
1233 	f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
1234 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1235 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1236 	interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
1237 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1238 
1239 	parent->default_groups = f_default_groups;
1240 	os_desc_type->ct_owner = owner;
1241 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1242 	f_default_groups[0] = os_desc_group;
1243 
1244 	os_desc_group->default_groups = interface_groups;
1245 	interface_type->ct_item_ops = &interf_item_ops;
1246 	interface_type->ct_group_ops = &interf_grp_ops;
1247 	interface_type->ct_attrs = interf_grp_attrs;
1248 	interface_type->ct_owner = owner;
1249 
1250 	while (n_interf--) {
1251 		struct usb_os_desc *d;
1252 
1253 		d = desc[n_interf];
1254 		d->owner = owner;
1255 		config_group_init_type_name(&d->group, "", interface_type);
1256 		config_item_set_name(&d->group.cg_item, "interface.%s",
1257 				     names[n_interf]);
1258 		interface_groups[n_interf] = &d->group;
1259 	}
1260 
1261 	return 0;
1262 }
1263 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1264 
1265 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1266 {
1267 	WARN_ON(1);
1268 	return -EINVAL;
1269 }
1270 
1271 int composite_dev_prepare(struct usb_composite_driver *composite,
1272 		struct usb_composite_dev *dev);
1273 
1274 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1275 				  struct usb_ep *ep0);
1276 
1277 static void purge_configs_funcs(struct gadget_info *gi)
1278 {
1279 	struct usb_configuration	*c;
1280 
1281 	list_for_each_entry(c, &gi->cdev.configs, list) {
1282 		struct usb_function *f, *tmp;
1283 		struct config_usb_cfg *cfg;
1284 
1285 		cfg = container_of(c, struct config_usb_cfg, c);
1286 
1287 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1288 
1289 			list_move_tail(&f->list, &cfg->func_list);
1290 			if (f->unbind) {
1291 				dev_err(&gi->cdev.gadget->dev, "unbind function"
1292 						" '%s'/%p\n", f->name, f);
1293 				f->unbind(c, f);
1294 			}
1295 		}
1296 		c->next_interface_id = 0;
1297 		memset(c->interface, 0, sizeof(c->interface));
1298 		c->superspeed = 0;
1299 		c->highspeed = 0;
1300 		c->fullspeed = 0;
1301 	}
1302 }
1303 
1304 static int configfs_composite_bind(struct usb_gadget *gadget,
1305 		struct usb_gadget_driver *gdriver)
1306 {
1307 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1308 	struct gadget_info		*gi = container_of(composite,
1309 						struct gadget_info, composite);
1310 	struct usb_composite_dev	*cdev = &gi->cdev;
1311 	struct usb_configuration	*c;
1312 	struct usb_string		*s;
1313 	unsigned			i;
1314 	int				ret;
1315 
1316 	/* the gi->lock is hold by the caller */
1317 	cdev->gadget = gadget;
1318 	set_gadget_data(gadget, cdev);
1319 	ret = composite_dev_prepare(composite, cdev);
1320 	if (ret)
1321 		return ret;
1322 	/* and now the gadget bind */
1323 	ret = -EINVAL;
1324 
1325 	if (list_empty(&gi->cdev.configs)) {
1326 		pr_err("Need at least one configuration in %s.\n",
1327 				gi->composite.name);
1328 		goto err_comp_cleanup;
1329 	}
1330 
1331 
1332 	list_for_each_entry(c, &gi->cdev.configs, list) {
1333 		struct config_usb_cfg *cfg;
1334 
1335 		cfg = container_of(c, struct config_usb_cfg, c);
1336 		if (list_empty(&cfg->func_list)) {
1337 			pr_err("Config %s/%d of %s needs at least one function.\n",
1338 			      c->label, c->bConfigurationValue,
1339 			      gi->composite.name);
1340 			goto err_comp_cleanup;
1341 		}
1342 	}
1343 
1344 	/* init all strings */
1345 	if (!list_empty(&gi->string_list)) {
1346 		struct gadget_strings *gs;
1347 
1348 		i = 0;
1349 		list_for_each_entry(gs, &gi->string_list, list) {
1350 
1351 			gi->gstrings[i] = &gs->stringtab_dev;
1352 			gs->stringtab_dev.strings = gs->strings;
1353 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1354 				gs->manufacturer;
1355 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1356 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1357 			i++;
1358 		}
1359 		gi->gstrings[i] = NULL;
1360 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1361 				USB_GADGET_FIRST_AVAIL_IDX);
1362 		if (IS_ERR(s)) {
1363 			ret = PTR_ERR(s);
1364 			goto err_comp_cleanup;
1365 		}
1366 
1367 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1368 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1369 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1370 	}
1371 
1372 	if (gi->use_os_desc) {
1373 		cdev->use_os_string = true;
1374 		cdev->b_vendor_code = gi->b_vendor_code;
1375 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1376 	}
1377 
1378 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1379 		struct usb_descriptor_header *usb_desc;
1380 
1381 		usb_desc = usb_otg_descriptor_alloc(gadget);
1382 		if (!usb_desc) {
1383 			ret = -ENOMEM;
1384 			goto err_comp_cleanup;
1385 		}
1386 		usb_otg_descriptor_init(gadget, usb_desc);
1387 		otg_desc[0] = usb_desc;
1388 		otg_desc[1] = NULL;
1389 	}
1390 
1391 	/* Go through all configs, attach all functions */
1392 	list_for_each_entry(c, &gi->cdev.configs, list) {
1393 		struct config_usb_cfg *cfg;
1394 		struct usb_function *f;
1395 		struct usb_function *tmp;
1396 		struct gadget_config_name *cn;
1397 
1398 		if (gadget_is_otg(gadget))
1399 			c->descriptors = otg_desc;
1400 
1401 		cfg = container_of(c, struct config_usb_cfg, c);
1402 		if (!list_empty(&cfg->string_list)) {
1403 			i = 0;
1404 			list_for_each_entry(cn, &cfg->string_list, list) {
1405 				cfg->gstrings[i] = &cn->stringtab_dev;
1406 				cn->stringtab_dev.strings = &cn->strings;
1407 				cn->strings.s = cn->configuration;
1408 				i++;
1409 			}
1410 			cfg->gstrings[i] = NULL;
1411 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1412 			if (IS_ERR(s)) {
1413 				ret = PTR_ERR(s);
1414 				goto err_comp_cleanup;
1415 			}
1416 			c->iConfiguration = s[0].id;
1417 		}
1418 
1419 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1420 			list_del(&f->list);
1421 			ret = usb_add_function(c, f);
1422 			if (ret) {
1423 				list_add(&f->list, &cfg->func_list);
1424 				goto err_purge_funcs;
1425 			}
1426 		}
1427 		usb_ep_autoconfig_reset(cdev->gadget);
1428 	}
1429 	if (cdev->use_os_string) {
1430 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1431 		if (ret)
1432 			goto err_purge_funcs;
1433 	}
1434 
1435 	usb_ep_autoconfig_reset(cdev->gadget);
1436 	return 0;
1437 
1438 err_purge_funcs:
1439 	purge_configs_funcs(gi);
1440 err_comp_cleanup:
1441 	composite_dev_cleanup(cdev);
1442 	return ret;
1443 }
1444 
1445 static void configfs_composite_unbind(struct usb_gadget *gadget)
1446 {
1447 	struct usb_composite_dev	*cdev;
1448 	struct gadget_info		*gi;
1449 
1450 	/* the gi->lock is hold by the caller */
1451 
1452 	cdev = get_gadget_data(gadget);
1453 	gi = container_of(cdev, struct gadget_info, cdev);
1454 
1455 	kfree(otg_desc[0]);
1456 	otg_desc[0] = NULL;
1457 	purge_configs_funcs(gi);
1458 	composite_dev_cleanup(cdev);
1459 	usb_ep_autoconfig_reset(cdev->gadget);
1460 	cdev->gadget = NULL;
1461 	set_gadget_data(gadget, NULL);
1462 }
1463 
1464 static const struct usb_gadget_driver configfs_driver_template = {
1465 	.bind           = configfs_composite_bind,
1466 	.unbind         = configfs_composite_unbind,
1467 
1468 	.setup          = composite_setup,
1469 	.reset          = composite_disconnect,
1470 	.disconnect     = composite_disconnect,
1471 
1472 	.suspend	= composite_suspend,
1473 	.resume		= composite_resume,
1474 
1475 	.max_speed	= USB_SPEED_SUPER,
1476 	.driver = {
1477 		.owner          = THIS_MODULE,
1478 		.name		= "configfs-gadget",
1479 	},
1480 };
1481 
1482 static struct config_group *gadgets_make(
1483 		struct config_group *group,
1484 		const char *name)
1485 {
1486 	struct gadget_info *gi;
1487 
1488 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1489 	if (!gi)
1490 		return ERR_PTR(-ENOMEM);
1491 
1492 	gi->group.default_groups = gi->default_groups;
1493 	gi->group.default_groups[0] = &gi->functions_group;
1494 	gi->group.default_groups[1] = &gi->configs_group;
1495 	gi->group.default_groups[2] = &gi->strings_group;
1496 	gi->group.default_groups[3] = &gi->os_desc_group;
1497 
1498 	config_group_init_type_name(&gi->functions_group, "functions",
1499 			&functions_type);
1500 	config_group_init_type_name(&gi->configs_group, "configs",
1501 			&config_desc_type);
1502 	config_group_init_type_name(&gi->strings_group, "strings",
1503 			&gadget_strings_strings_type);
1504 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1505 			&os_desc_type);
1506 
1507 	gi->composite.bind = configfs_do_nothing;
1508 	gi->composite.unbind = configfs_do_nothing;
1509 	gi->composite.suspend = NULL;
1510 	gi->composite.resume = NULL;
1511 	gi->composite.max_speed = USB_SPEED_SUPER;
1512 
1513 	mutex_init(&gi->lock);
1514 	INIT_LIST_HEAD(&gi->string_list);
1515 	INIT_LIST_HEAD(&gi->available_func);
1516 
1517 	composite_init_dev(&gi->cdev);
1518 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1519 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1520 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1521 
1522 	gi->composite.gadget_driver = configfs_driver_template;
1523 
1524 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1525 	gi->composite.name = gi->composite.gadget_driver.function;
1526 
1527 	if (!gi->composite.gadget_driver.function)
1528 		goto err;
1529 
1530 	config_group_init_type_name(&gi->group, name,
1531 				&gadget_root_type);
1532 	return &gi->group;
1533 err:
1534 	kfree(gi);
1535 	return ERR_PTR(-ENOMEM);
1536 }
1537 
1538 static void gadgets_drop(struct config_group *group, struct config_item *item)
1539 {
1540 	config_item_put(item);
1541 }
1542 
1543 static struct configfs_group_operations gadgets_ops = {
1544 	.make_group     = &gadgets_make,
1545 	.drop_item      = &gadgets_drop,
1546 };
1547 
1548 static struct config_item_type gadgets_type = {
1549 	.ct_group_ops   = &gadgets_ops,
1550 	.ct_owner       = THIS_MODULE,
1551 };
1552 
1553 static struct configfs_subsystem gadget_subsys = {
1554 	.su_group = {
1555 		.cg_item = {
1556 			.ci_namebuf = "usb_gadget",
1557 			.ci_type = &gadgets_type,
1558 		},
1559 	},
1560 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1561 };
1562 
1563 void unregister_gadget_item(struct config_item *item)
1564 {
1565 	struct gadget_info *gi = to_gadget_info(item);
1566 
1567 	unregister_gadget(gi);
1568 }
1569 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1570 
1571 static int __init gadget_cfs_init(void)
1572 {
1573 	int ret;
1574 
1575 	config_group_init(&gadget_subsys.su_group);
1576 
1577 	ret = configfs_register_subsystem(&gadget_subsys);
1578 	return ret;
1579 }
1580 module_init(gadget_cfs_init);
1581 
1582 static void __exit gadget_cfs_exit(void)
1583 {
1584 	configfs_unregister_subsystem(&gadget_subsys);
1585 }
1586 module_exit(gadget_cfs_exit);
1587