xref: /linux/drivers/usb/gadget/configfs.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 struct gadget_info {
45 	struct config_group group;
46 	struct config_group functions_group;
47 	struct config_group configs_group;
48 	struct config_group strings_group;
49 	struct config_group os_desc_group;
50 	struct config_group *default_groups[5];
51 
52 	struct mutex lock;
53 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
54 	struct list_head string_list;
55 	struct list_head available_func;
56 
57 	const char *udc_name;
58 #ifdef CONFIG_USB_OTG
59 	struct usb_otg_descriptor otg;
60 #endif
61 	struct usb_composite_driver composite;
62 	struct usb_composite_dev cdev;
63 	bool use_os_desc;
64 	char b_vendor_code;
65 	char qw_sign[OS_STRING_QW_SIGN_LEN];
66 };
67 
68 struct config_usb_cfg {
69 	struct config_group group;
70 	struct config_group strings_group;
71 	struct config_group *default_groups[2];
72 	struct list_head string_list;
73 	struct usb_configuration c;
74 	struct list_head func_list;
75 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
76 };
77 
78 struct gadget_strings {
79 	struct usb_gadget_strings stringtab_dev;
80 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
81 	char *manufacturer;
82 	char *product;
83 	char *serialnumber;
84 
85 	struct config_group group;
86 	struct list_head list;
87 };
88 
89 struct os_desc {
90 	struct config_group group;
91 };
92 
93 struct gadget_config_name {
94 	struct usb_gadget_strings stringtab_dev;
95 	struct usb_string strings;
96 	char *configuration;
97 
98 	struct config_group group;
99 	struct list_head list;
100 };
101 
102 static int usb_string_copy(const char *s, char **s_copy)
103 {
104 	int ret;
105 	char *str;
106 	char *copy = *s_copy;
107 	ret = strlen(s);
108 	if (ret > 126)
109 		return -EOVERFLOW;
110 
111 	str = kstrdup(s, GFP_KERNEL);
112 	if (!str)
113 		return -ENOMEM;
114 	if (str[ret - 1] == '\n')
115 		str[ret - 1] = '\0';
116 	kfree(copy);
117 	*s_copy = str;
118 	return 0;
119 }
120 
121 CONFIGFS_ATTR_STRUCT(gadget_info);
122 CONFIGFS_ATTR_STRUCT(config_usb_cfg);
123 
124 #define GI_DEVICE_DESC_ITEM_ATTR(name)	\
125 	static struct gadget_info_attribute gadget_cdev_desc_##name = \
126 		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
127 				gadget_dev_desc_##name##_show,		\
128 				gadget_dev_desc_##name##_store)
129 
130 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
131 	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
132 			char *page)	\
133 {	\
134 	return sprintf(page, "0x%02x\n", gi->cdev.desc.__name);	\
135 }
136 
137 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
138 	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
139 			char *page)	\
140 {	\
141 	return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
142 }
143 
144 
145 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
146 	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
147 		const char *page, size_t len)		\
148 {							\
149 	u8 val;						\
150 	int ret;					\
151 	ret = kstrtou8(page, 0, &val);			\
152 	if (ret)					\
153 		return ret;				\
154 	gi->cdev.desc._name = val;			\
155 	return len;					\
156 }
157 
158 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
159 	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
160 		const char *page, size_t len)		\
161 {							\
162 	u16 val;					\
163 	int ret;					\
164 	ret = kstrtou16(page, 0, &val);			\
165 	if (ret)					\
166 		return ret;				\
167 	gi->cdev.desc._name = cpu_to_le16p(&val);	\
168 	return len;					\
169 }
170 
171 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
172 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
173 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
174 
175 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
176 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
177 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
178 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
179 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
180 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
181 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
182 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
183 
184 static ssize_t is_valid_bcd(u16 bcd_val)
185 {
186 	if ((bcd_val & 0xf) > 9)
187 		return -EINVAL;
188 	if (((bcd_val >> 4) & 0xf) > 9)
189 		return -EINVAL;
190 	if (((bcd_val >> 8) & 0xf) > 9)
191 		return -EINVAL;
192 	if (((bcd_val >> 12) & 0xf) > 9)
193 		return -EINVAL;
194 	return 0;
195 }
196 
197 static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
198 		const char *page, size_t len)
199 {
200 	u16 bcdDevice;
201 	int ret;
202 
203 	ret = kstrtou16(page, 0, &bcdDevice);
204 	if (ret)
205 		return ret;
206 	ret = is_valid_bcd(bcdDevice);
207 	if (ret)
208 		return ret;
209 
210 	gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
211 	return len;
212 }
213 
214 static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
215 		const char *page, size_t len)
216 {
217 	u16 bcdUSB;
218 	int ret;
219 
220 	ret = kstrtou16(page, 0, &bcdUSB);
221 	if (ret)
222 		return ret;
223 	ret = is_valid_bcd(bcdUSB);
224 	if (ret)
225 		return ret;
226 
227 	gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
228 	return len;
229 }
230 
231 static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
232 {
233 	return sprintf(page, "%s\n", gi->udc_name ?: "");
234 }
235 
236 static int unregister_gadget(struct gadget_info *gi)
237 {
238 	int ret;
239 
240 	if (!gi->udc_name)
241 		return -ENODEV;
242 
243 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
244 	if (ret)
245 		return ret;
246 	kfree(gi->udc_name);
247 	gi->udc_name = NULL;
248 	return 0;
249 }
250 
251 static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
252 		const char *page, size_t len)
253 {
254 	char *name;
255 	int ret;
256 
257 	name = kstrdup(page, GFP_KERNEL);
258 	if (!name)
259 		return -ENOMEM;
260 	if (name[len - 1] == '\n')
261 		name[len - 1] = '\0';
262 
263 	mutex_lock(&gi->lock);
264 
265 	if (!strlen(name)) {
266 		ret = unregister_gadget(gi);
267 		if (ret)
268 			goto err;
269 	} else {
270 		if (gi->udc_name) {
271 			ret = -EBUSY;
272 			goto err;
273 		}
274 		ret = usb_udc_attach_driver(name, &gi->composite.gadget_driver);
275 		if (ret)
276 			goto err;
277 		gi->udc_name = name;
278 	}
279 	mutex_unlock(&gi->lock);
280 	return len;
281 err:
282 	kfree(name);
283 	mutex_unlock(&gi->lock);
284 	return ret;
285 }
286 
287 GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
288 GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
289 GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
290 GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
291 GI_DEVICE_DESC_ITEM_ATTR(idVendor);
292 GI_DEVICE_DESC_ITEM_ATTR(idProduct);
293 GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
294 GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
295 GI_DEVICE_DESC_ITEM_ATTR(UDC);
296 
297 static struct configfs_attribute *gadget_root_attrs[] = {
298 	&gadget_cdev_desc_bDeviceClass.attr,
299 	&gadget_cdev_desc_bDeviceSubClass.attr,
300 	&gadget_cdev_desc_bDeviceProtocol.attr,
301 	&gadget_cdev_desc_bMaxPacketSize0.attr,
302 	&gadget_cdev_desc_idVendor.attr,
303 	&gadget_cdev_desc_idProduct.attr,
304 	&gadget_cdev_desc_bcdDevice.attr,
305 	&gadget_cdev_desc_bcdUSB.attr,
306 	&gadget_cdev_desc_UDC.attr,
307 	NULL,
308 };
309 
310 static inline struct gadget_info *to_gadget_info(struct config_item *item)
311 {
312 	 return container_of(to_config_group(item), struct gadget_info, group);
313 }
314 
315 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
316 {
317 	 return container_of(to_config_group(item), struct gadget_strings,
318 			 group);
319 }
320 
321 static inline struct gadget_config_name *to_gadget_config_name(
322 		struct config_item *item)
323 {
324 	 return container_of(to_config_group(item), struct gadget_config_name,
325 			 group);
326 }
327 
328 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
329 {
330 	return container_of(to_config_group(item), struct config_usb_cfg,
331 			group);
332 }
333 
334 static inline struct usb_function_instance *to_usb_function_instance(
335 		struct config_item *item)
336 {
337 	 return container_of(to_config_group(item),
338 			 struct usb_function_instance, group);
339 }
340 
341 static void gadget_info_attr_release(struct config_item *item)
342 {
343 	struct gadget_info *gi = to_gadget_info(item);
344 
345 	WARN_ON(!list_empty(&gi->cdev.configs));
346 	WARN_ON(!list_empty(&gi->string_list));
347 	WARN_ON(!list_empty(&gi->available_func));
348 	kfree(gi->composite.gadget_driver.function);
349 	kfree(gi);
350 }
351 
352 CONFIGFS_ATTR_OPS(gadget_info);
353 
354 static struct configfs_item_operations gadget_root_item_ops = {
355 	.release                = gadget_info_attr_release,
356 	.show_attribute         = gadget_info_attr_show,
357 	.store_attribute        = gadget_info_attr_store,
358 };
359 
360 static void gadget_config_attr_release(struct config_item *item)
361 {
362 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
363 
364 	WARN_ON(!list_empty(&cfg->c.functions));
365 	list_del(&cfg->c.list);
366 	kfree(cfg->c.label);
367 	kfree(cfg);
368 }
369 
370 static int config_usb_cfg_link(
371 	struct config_item *usb_cfg_ci,
372 	struct config_item *usb_func_ci)
373 {
374 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
375 	struct usb_composite_dev *cdev = cfg->c.cdev;
376 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
377 
378 	struct config_group *group = to_config_group(usb_func_ci);
379 	struct usb_function_instance *fi = container_of(group,
380 			struct usb_function_instance, group);
381 	struct usb_function_instance *a_fi;
382 	struct usb_function *f;
383 	int ret;
384 
385 	mutex_lock(&gi->lock);
386 	/*
387 	 * Make sure this function is from within our _this_ gadget and not
388 	 * from another gadget or a random directory.
389 	 * Also a function instance can only be linked once.
390 	 */
391 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
392 		if (a_fi == fi)
393 			break;
394 	}
395 	if (a_fi != fi) {
396 		ret = -EINVAL;
397 		goto out;
398 	}
399 
400 	list_for_each_entry(f, &cfg->func_list, list) {
401 		if (f->fi == fi) {
402 			ret = -EEXIST;
403 			goto out;
404 		}
405 	}
406 
407 	f = usb_get_function(fi);
408 	if (IS_ERR(f)) {
409 		ret = PTR_ERR(f);
410 		goto out;
411 	}
412 
413 	/* stash the function until we bind it to the gadget */
414 	list_add_tail(&f->list, &cfg->func_list);
415 	ret = 0;
416 out:
417 	mutex_unlock(&gi->lock);
418 	return ret;
419 }
420 
421 static int config_usb_cfg_unlink(
422 	struct config_item *usb_cfg_ci,
423 	struct config_item *usb_func_ci)
424 {
425 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
426 	struct usb_composite_dev *cdev = cfg->c.cdev;
427 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
428 
429 	struct config_group *group = to_config_group(usb_func_ci);
430 	struct usb_function_instance *fi = container_of(group,
431 			struct usb_function_instance, group);
432 	struct usb_function *f;
433 
434 	/*
435 	 * ideally I would like to forbid to unlink functions while a gadget is
436 	 * bound to an UDC. Since this isn't possible at the moment, we simply
437 	 * force an unbind, the function is available here and then we can
438 	 * remove the function.
439 	 */
440 	mutex_lock(&gi->lock);
441 	if (gi->udc_name)
442 		unregister_gadget(gi);
443 	WARN_ON(gi->udc_name);
444 
445 	list_for_each_entry(f, &cfg->func_list, list) {
446 		if (f->fi == fi) {
447 			list_del(&f->list);
448 			usb_put_function(f);
449 			mutex_unlock(&gi->lock);
450 			return 0;
451 		}
452 	}
453 	mutex_unlock(&gi->lock);
454 	WARN(1, "Unable to locate function to unbind\n");
455 	return 0;
456 }
457 
458 CONFIGFS_ATTR_OPS(config_usb_cfg);
459 
460 static struct configfs_item_operations gadget_config_item_ops = {
461 	.release                = gadget_config_attr_release,
462 	.show_attribute         = config_usb_cfg_attr_show,
463 	.store_attribute        = config_usb_cfg_attr_store,
464 	.allow_link             = config_usb_cfg_link,
465 	.drop_link              = config_usb_cfg_unlink,
466 };
467 
468 
469 static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
470 		char *page)
471 {
472 	return sprintf(page, "%u\n", cfg->c.MaxPower);
473 }
474 
475 static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
476 		const char *page, size_t len)
477 {
478 	u16 val;
479 	int ret;
480 	ret = kstrtou16(page, 0, &val);
481 	if (ret)
482 		return ret;
483 	if (DIV_ROUND_UP(val, 8) > 0xff)
484 		return -ERANGE;
485 	cfg->c.MaxPower = val;
486 	return len;
487 }
488 
489 static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
490 		char *page)
491 {
492 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
493 }
494 
495 static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
496 		const char *page, size_t len)
497 {
498 	u8 val;
499 	int ret;
500 	ret = kstrtou8(page, 0, &val);
501 	if (ret)
502 		return ret;
503 	if (!(val & USB_CONFIG_ATT_ONE))
504 		return -EINVAL;
505 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
506 				USB_CONFIG_ATT_WAKEUP))
507 		return -EINVAL;
508 	cfg->c.bmAttributes = val;
509 	return len;
510 }
511 
512 #define CFG_CONFIG_DESC_ITEM_ATTR(name)	\
513 	static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
514 		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
515 				gadget_config_desc_##name##_show,	\
516 				gadget_config_desc_##name##_store)
517 
518 CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
519 CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
520 
521 static struct configfs_attribute *gadget_config_attrs[] = {
522 	&gadget_usb_cfg_MaxPower.attr,
523 	&gadget_usb_cfg_bmAttributes.attr,
524 	NULL,
525 };
526 
527 static struct config_item_type gadget_config_type = {
528 	.ct_item_ops	= &gadget_config_item_ops,
529 	.ct_attrs	= gadget_config_attrs,
530 	.ct_owner	= THIS_MODULE,
531 };
532 
533 static struct config_item_type gadget_root_type = {
534 	.ct_item_ops	= &gadget_root_item_ops,
535 	.ct_attrs	= gadget_root_attrs,
536 	.ct_owner	= THIS_MODULE,
537 };
538 
539 static void composite_init_dev(struct usb_composite_dev *cdev)
540 {
541 	spin_lock_init(&cdev->lock);
542 	INIT_LIST_HEAD(&cdev->configs);
543 	INIT_LIST_HEAD(&cdev->gstrings);
544 }
545 
546 static struct config_group *function_make(
547 		struct config_group *group,
548 		const char *name)
549 {
550 	struct gadget_info *gi;
551 	struct usb_function_instance *fi;
552 	char buf[MAX_NAME_LEN];
553 	char *func_name;
554 	char *instance_name;
555 	int ret;
556 
557 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
558 	if (ret >= MAX_NAME_LEN)
559 		return ERR_PTR(-ENAMETOOLONG);
560 
561 	func_name = buf;
562 	instance_name = strchr(func_name, '.');
563 	if (!instance_name) {
564 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
565 		return ERR_PTR(-EINVAL);
566 	}
567 	*instance_name = '\0';
568 	instance_name++;
569 
570 	fi = usb_get_function_instance(func_name);
571 	if (IS_ERR(fi))
572 		return ERR_CAST(fi);
573 
574 	ret = config_item_set_name(&fi->group.cg_item, name);
575 	if (ret) {
576 		usb_put_function_instance(fi);
577 		return ERR_PTR(ret);
578 	}
579 	if (fi->set_inst_name) {
580 		ret = fi->set_inst_name(fi, instance_name);
581 		if (ret) {
582 			usb_put_function_instance(fi);
583 			return ERR_PTR(ret);
584 		}
585 	}
586 
587 	gi = container_of(group, struct gadget_info, functions_group);
588 
589 	mutex_lock(&gi->lock);
590 	list_add_tail(&fi->cfs_list, &gi->available_func);
591 	mutex_unlock(&gi->lock);
592 	return &fi->group;
593 }
594 
595 static void function_drop(
596 		struct config_group *group,
597 		struct config_item *item)
598 {
599 	struct usb_function_instance *fi = to_usb_function_instance(item);
600 	struct gadget_info *gi;
601 
602 	gi = container_of(group, struct gadget_info, functions_group);
603 
604 	mutex_lock(&gi->lock);
605 	list_del(&fi->cfs_list);
606 	mutex_unlock(&gi->lock);
607 	config_item_put(item);
608 }
609 
610 static struct configfs_group_operations functions_ops = {
611 	.make_group     = &function_make,
612 	.drop_item      = &function_drop,
613 };
614 
615 static struct config_item_type functions_type = {
616 	.ct_group_ops   = &functions_ops,
617 	.ct_owner       = THIS_MODULE,
618 };
619 
620 CONFIGFS_ATTR_STRUCT(gadget_config_name);
621 GS_STRINGS_RW(gadget_config_name, configuration);
622 
623 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
624 	&gadget_config_name_configuration.attr,
625 	NULL,
626 };
627 
628 static void gadget_config_name_attr_release(struct config_item *item)
629 {
630 	struct gadget_config_name *cn = to_gadget_config_name(item);
631 
632 	kfree(cn->configuration);
633 
634 	list_del(&cn->list);
635 	kfree(cn);
636 }
637 
638 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
639 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
640 
641 static struct config_group *config_desc_make(
642 		struct config_group *group,
643 		const char *name)
644 {
645 	struct gadget_info *gi;
646 	struct config_usb_cfg *cfg;
647 	char buf[MAX_NAME_LEN];
648 	char *num_str;
649 	u8 num;
650 	int ret;
651 
652 	gi = container_of(group, struct gadget_info, configs_group);
653 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
654 	if (ret >= MAX_NAME_LEN)
655 		return ERR_PTR(-ENAMETOOLONG);
656 
657 	num_str = strchr(buf, '.');
658 	if (!num_str) {
659 		pr_err("Unable to locate . in name.bConfigurationValue\n");
660 		return ERR_PTR(-EINVAL);
661 	}
662 
663 	*num_str = '\0';
664 	num_str++;
665 
666 	if (!strlen(buf))
667 		return ERR_PTR(-EINVAL);
668 
669 	ret = kstrtou8(num_str, 0, &num);
670 	if (ret)
671 		return ERR_PTR(ret);
672 
673 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
674 	if (!cfg)
675 		return ERR_PTR(-ENOMEM);
676 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
677 	if (!cfg->c.label) {
678 		ret = -ENOMEM;
679 		goto err;
680 	}
681 	cfg->c.bConfigurationValue = num;
682 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
683 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
684 	INIT_LIST_HEAD(&cfg->string_list);
685 	INIT_LIST_HEAD(&cfg->func_list);
686 
687 	cfg->group.default_groups = cfg->default_groups;
688 	cfg->default_groups[0] = &cfg->strings_group;
689 
690 	config_group_init_type_name(&cfg->group, name,
691 				&gadget_config_type);
692 	config_group_init_type_name(&cfg->strings_group, "strings",
693 			&gadget_config_name_strings_type);
694 
695 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
696 	if (ret)
697 		goto err;
698 
699 	return &cfg->group;
700 err:
701 	kfree(cfg->c.label);
702 	kfree(cfg);
703 	return ERR_PTR(ret);
704 }
705 
706 static void config_desc_drop(
707 		struct config_group *group,
708 		struct config_item *item)
709 {
710 	config_item_put(item);
711 }
712 
713 static struct configfs_group_operations config_desc_ops = {
714 	.make_group     = &config_desc_make,
715 	.drop_item      = &config_desc_drop,
716 };
717 
718 static struct config_item_type config_desc_type = {
719 	.ct_group_ops   = &config_desc_ops,
720 	.ct_owner       = THIS_MODULE,
721 };
722 
723 CONFIGFS_ATTR_STRUCT(gadget_strings);
724 GS_STRINGS_RW(gadget_strings, manufacturer);
725 GS_STRINGS_RW(gadget_strings, product);
726 GS_STRINGS_RW(gadget_strings, serialnumber);
727 
728 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
729 	&gadget_strings_manufacturer.attr,
730 	&gadget_strings_product.attr,
731 	&gadget_strings_serialnumber.attr,
732 	NULL,
733 };
734 
735 static void gadget_strings_attr_release(struct config_item *item)
736 {
737 	struct gadget_strings *gs = to_gadget_strings(item);
738 
739 	kfree(gs->manufacturer);
740 	kfree(gs->product);
741 	kfree(gs->serialnumber);
742 
743 	list_del(&gs->list);
744 	kfree(gs);
745 }
746 
747 USB_CONFIG_STRING_RW_OPS(gadget_strings);
748 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
749 
750 static inline struct os_desc *to_os_desc(struct config_item *item)
751 {
752 	return container_of(to_config_group(item), struct os_desc, group);
753 }
754 
755 CONFIGFS_ATTR_STRUCT(os_desc);
756 CONFIGFS_ATTR_OPS(os_desc);
757 
758 static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
759 {
760 	struct gadget_info *gi;
761 
762 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
763 
764 	return sprintf(page, "%d", gi->use_os_desc);
765 }
766 
767 static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
768 				 size_t len)
769 {
770 	struct gadget_info *gi;
771 	int ret;
772 	bool use;
773 
774 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
775 
776 	mutex_lock(&gi->lock);
777 	ret = strtobool(page, &use);
778 	if (!ret) {
779 		gi->use_os_desc = use;
780 		ret = len;
781 	}
782 	mutex_unlock(&gi->lock);
783 
784 	return ret;
785 }
786 
787 static struct os_desc_attribute os_desc_use =
788 	__CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
789 			os_desc_use_show,
790 			os_desc_use_store);
791 
792 static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
793 {
794 	struct gadget_info *gi;
795 
796 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
797 
798 	return sprintf(page, "%d", gi->b_vendor_code);
799 }
800 
801 static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
802 					   const char *page, size_t len)
803 {
804 	struct gadget_info *gi;
805 	int ret;
806 	u8 b_vendor_code;
807 
808 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
809 
810 	mutex_lock(&gi->lock);
811 	ret = kstrtou8(page, 0, &b_vendor_code);
812 	if (!ret) {
813 		gi->b_vendor_code = b_vendor_code;
814 		ret = len;
815 	}
816 	mutex_unlock(&gi->lock);
817 
818 	return ret;
819 }
820 
821 static struct os_desc_attribute os_desc_b_vendor_code =
822 	__CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
823 			os_desc_b_vendor_code_show,
824 			os_desc_b_vendor_code_store);
825 
826 static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
827 {
828 	struct gadget_info *gi;
829 
830 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
831 
832 	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
833 
834 	return OS_STRING_QW_SIGN_LEN;
835 }
836 
837 static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
838 				     size_t len)
839 {
840 	struct gadget_info *gi;
841 	int res, l;
842 
843 	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
844 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
845 	if (page[l - 1] == '\n')
846 		--l;
847 
848 	mutex_lock(&gi->lock);
849 	res = utf8s_to_utf16s(page, l,
850 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
851 			      OS_STRING_QW_SIGN_LEN);
852 	if (res > 0)
853 		res = len;
854 	mutex_unlock(&gi->lock);
855 
856 	return res;
857 }
858 
859 static struct os_desc_attribute os_desc_qw_sign =
860 	__CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
861 			os_desc_qw_sign_show,
862 			os_desc_qw_sign_store);
863 
864 static struct configfs_attribute *os_desc_attrs[] = {
865 	&os_desc_use.attr,
866 	&os_desc_b_vendor_code.attr,
867 	&os_desc_qw_sign.attr,
868 	NULL,
869 };
870 
871 static void os_desc_attr_release(struct config_item *item)
872 {
873 	struct os_desc *os_desc = to_os_desc(item);
874 	kfree(os_desc);
875 }
876 
877 static int os_desc_link(struct config_item *os_desc_ci,
878 			struct config_item *usb_cfg_ci)
879 {
880 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
881 					struct gadget_info, os_desc_group);
882 	struct usb_composite_dev *cdev = &gi->cdev;
883 	struct config_usb_cfg *c_target =
884 		container_of(to_config_group(usb_cfg_ci),
885 			     struct config_usb_cfg, group);
886 	struct usb_configuration *c;
887 	int ret;
888 
889 	mutex_lock(&gi->lock);
890 	list_for_each_entry(c, &cdev->configs, list) {
891 		if (c == &c_target->c)
892 			break;
893 	}
894 	if (c != &c_target->c) {
895 		ret = -EINVAL;
896 		goto out;
897 	}
898 
899 	if (cdev->os_desc_config) {
900 		ret = -EBUSY;
901 		goto out;
902 	}
903 
904 	cdev->os_desc_config = &c_target->c;
905 	ret = 0;
906 
907 out:
908 	mutex_unlock(&gi->lock);
909 	return ret;
910 }
911 
912 static int os_desc_unlink(struct config_item *os_desc_ci,
913 			  struct config_item *usb_cfg_ci)
914 {
915 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
916 					struct gadget_info, os_desc_group);
917 	struct usb_composite_dev *cdev = &gi->cdev;
918 
919 	mutex_lock(&gi->lock);
920 	if (gi->udc_name)
921 		unregister_gadget(gi);
922 	cdev->os_desc_config = NULL;
923 	WARN_ON(gi->udc_name);
924 	mutex_unlock(&gi->lock);
925 	return 0;
926 }
927 
928 static struct configfs_item_operations os_desc_ops = {
929 	.release                = os_desc_attr_release,
930 	.show_attribute         = os_desc_attr_show,
931 	.store_attribute        = os_desc_attr_store,
932 	.allow_link		= os_desc_link,
933 	.drop_link		= os_desc_unlink,
934 };
935 
936 static struct config_item_type os_desc_type = {
937 	.ct_item_ops	= &os_desc_ops,
938 	.ct_attrs	= os_desc_attrs,
939 	.ct_owner	= THIS_MODULE,
940 };
941 
942 CONFIGFS_ATTR_STRUCT(usb_os_desc);
943 CONFIGFS_ATTR_OPS(usb_os_desc);
944 
945 
946 static inline struct usb_os_desc_ext_prop
947 *to_usb_os_desc_ext_prop(struct config_item *item)
948 {
949 	return container_of(item, struct usb_os_desc_ext_prop, item);
950 }
951 
952 CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop);
953 CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop);
954 
955 static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop,
956 				  char *page)
957 {
958 	return sprintf(page, "%d", ext_prop->type);
959 }
960 
961 static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop,
962 				   const char *page, size_t len)
963 {
964 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
965 	u8 type;
966 	int ret;
967 
968 	if (desc->opts_mutex)
969 		mutex_lock(desc->opts_mutex);
970 	ret = kstrtou8(page, 0, &type);
971 	if (ret)
972 		goto end;
973 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
974 		ret = -EINVAL;
975 		goto end;
976 	}
977 
978 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
979 	    ext_prop->type == USB_EXT_PROP_LE32 ||
980 	    ext_prop->type == USB_EXT_PROP_BE32) &&
981 	    (type == USB_EXT_PROP_UNICODE ||
982 	    type == USB_EXT_PROP_UNICODE_ENV ||
983 	    type == USB_EXT_PROP_UNICODE_LINK))
984 		ext_prop->data_len <<= 1;
985 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
986 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
987 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
988 		   (type == USB_EXT_PROP_BINARY ||
989 		   type == USB_EXT_PROP_LE32 ||
990 		   type == USB_EXT_PROP_BE32))
991 		ext_prop->data_len >>= 1;
992 	ext_prop->type = type;
993 	ret = len;
994 
995 end:
996 	if (desc->opts_mutex)
997 		mutex_unlock(desc->opts_mutex);
998 	return ret;
999 }
1000 
1001 static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
1002 				  char *page)
1003 {
1004 	int len = ext_prop->data_len;
1005 
1006 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1007 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1008 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1009 		len >>= 1;
1010 	memcpy(page, ext_prop->data, len);
1011 
1012 	return len;
1013 }
1014 
1015 static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
1016 				   const char *page, size_t len)
1017 {
1018 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1019 	char *new_data;
1020 	size_t ret_len = len;
1021 
1022 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1023 		--len;
1024 	new_data = kmemdup(page, len, GFP_KERNEL);
1025 	if (!new_data)
1026 		return -ENOMEM;
1027 
1028 	if (desc->opts_mutex)
1029 		mutex_lock(desc->opts_mutex);
1030 	kfree(ext_prop->data);
1031 	ext_prop->data = new_data;
1032 	desc->ext_prop_len -= ext_prop->data_len;
1033 	ext_prop->data_len = len;
1034 	desc->ext_prop_len += ext_prop->data_len;
1035 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1036 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1037 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1038 		desc->ext_prop_len -= ext_prop->data_len;
1039 		ext_prop->data_len <<= 1;
1040 		ext_prop->data_len += 2;
1041 		desc->ext_prop_len += ext_prop->data_len;
1042 	}
1043 	if (desc->opts_mutex)
1044 		mutex_unlock(desc->opts_mutex);
1045 	return ret_len;
1046 }
1047 
1048 static struct usb_os_desc_ext_prop_attribute ext_prop_type =
1049 	__CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR,
1050 			ext_prop_type_show, ext_prop_type_store);
1051 
1052 static struct usb_os_desc_ext_prop_attribute ext_prop_data =
1053 	__CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR,
1054 			ext_prop_data_show, ext_prop_data_store);
1055 
1056 static struct configfs_attribute *ext_prop_attrs[] = {
1057 	&ext_prop_type.attr,
1058 	&ext_prop_data.attr,
1059 	NULL,
1060 };
1061 
1062 static void usb_os_desc_ext_prop_release(struct config_item *item)
1063 {
1064 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1065 
1066 	kfree(ext_prop); /* frees a whole chunk */
1067 }
1068 
1069 static struct configfs_item_operations ext_prop_ops = {
1070 	.release		= usb_os_desc_ext_prop_release,
1071 	.show_attribute		= usb_os_desc_ext_prop_attr_show,
1072 	.store_attribute	= usb_os_desc_ext_prop_attr_store,
1073 };
1074 
1075 static struct config_item *ext_prop_make(
1076 		struct config_group *group,
1077 		const char *name)
1078 {
1079 	struct usb_os_desc_ext_prop *ext_prop;
1080 	struct config_item_type *ext_prop_type;
1081 	struct usb_os_desc *desc;
1082 	char *vlabuf;
1083 
1084 	vla_group(data_chunk);
1085 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1086 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1087 
1088 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1089 	if (!vlabuf)
1090 		return ERR_PTR(-ENOMEM);
1091 
1092 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1093 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1094 
1095 	desc = container_of(group, struct usb_os_desc, group);
1096 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1097 	ext_prop_type->ct_attrs = ext_prop_attrs;
1098 	ext_prop_type->ct_owner = desc->owner;
1099 
1100 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1101 
1102 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1103 	if (!ext_prop->name) {
1104 		kfree(vlabuf);
1105 		return ERR_PTR(-ENOMEM);
1106 	}
1107 	desc->ext_prop_len += 14;
1108 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1109 	if (desc->opts_mutex)
1110 		mutex_lock(desc->opts_mutex);
1111 	desc->ext_prop_len += ext_prop->name_len;
1112 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1113 	++desc->ext_prop_count;
1114 	if (desc->opts_mutex)
1115 		mutex_unlock(desc->opts_mutex);
1116 
1117 	return &ext_prop->item;
1118 }
1119 
1120 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1121 {
1122 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1123 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1124 
1125 	if (desc->opts_mutex)
1126 		mutex_lock(desc->opts_mutex);
1127 	list_del(&ext_prop->entry);
1128 	--desc->ext_prop_count;
1129 	kfree(ext_prop->name);
1130 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1131 	if (desc->opts_mutex)
1132 		mutex_unlock(desc->opts_mutex);
1133 	config_item_put(item);
1134 }
1135 
1136 static struct configfs_group_operations interf_grp_ops = {
1137 	.make_item	= &ext_prop_make,
1138 	.drop_item	= &ext_prop_drop,
1139 };
1140 
1141 static struct configfs_item_operations interf_item_ops = {
1142 	.show_attribute		= usb_os_desc_attr_show,
1143 	.store_attribute	= usb_os_desc_attr_store,
1144 };
1145 
1146 static ssize_t interf_grp_compatible_id_show(struct usb_os_desc *desc,
1147 					     char *page)
1148 {
1149 	memcpy(page, desc->ext_compat_id, 8);
1150 	return 8;
1151 }
1152 
1153 static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc,
1154 					      const char *page, size_t len)
1155 {
1156 	int l;
1157 
1158 	l = min_t(int, 8, len);
1159 	if (page[l - 1] == '\n')
1160 		--l;
1161 	if (desc->opts_mutex)
1162 		mutex_lock(desc->opts_mutex);
1163 	memcpy(desc->ext_compat_id, page, l);
1164 
1165 	if (desc->opts_mutex)
1166 		mutex_unlock(desc->opts_mutex);
1167 
1168 	return len;
1169 }
1170 
1171 static struct usb_os_desc_attribute interf_grp_attr_compatible_id =
1172 	__CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
1173 			interf_grp_compatible_id_show,
1174 			interf_grp_compatible_id_store);
1175 
1176 static ssize_t interf_grp_sub_compatible_id_show(struct usb_os_desc *desc,
1177 						 char *page)
1178 {
1179 	memcpy(page, desc->ext_compat_id + 8, 8);
1180 	return 8;
1181 }
1182 
1183 static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc,
1184 						  const char *page, size_t len)
1185 {
1186 	int l;
1187 
1188 	l = min_t(int, 8, len);
1189 	if (page[l - 1] == '\n')
1190 		--l;
1191 	if (desc->opts_mutex)
1192 		mutex_lock(desc->opts_mutex);
1193 	memcpy(desc->ext_compat_id + 8, page, l);
1194 
1195 	if (desc->opts_mutex)
1196 		mutex_unlock(desc->opts_mutex);
1197 
1198 	return len;
1199 }
1200 
1201 static struct usb_os_desc_attribute interf_grp_attr_sub_compatible_id =
1202 	__CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
1203 			interf_grp_sub_compatible_id_show,
1204 			interf_grp_sub_compatible_id_store);
1205 
1206 static struct configfs_attribute *interf_grp_attrs[] = {
1207 	&interf_grp_attr_compatible_id.attr,
1208 	&interf_grp_attr_sub_compatible_id.attr,
1209 	NULL
1210 };
1211 
1212 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1213 				   int n_interf,
1214 				   struct usb_os_desc **desc,
1215 				   char **names,
1216 				   struct module *owner)
1217 {
1218 	struct config_group **f_default_groups, *os_desc_group,
1219 				**interface_groups;
1220 	struct config_item_type *os_desc_type, *interface_type;
1221 
1222 	vla_group(data_chunk);
1223 	vla_item(data_chunk, struct config_group *, f_default_groups, 2);
1224 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1225 	vla_item(data_chunk, struct config_group *, interface_groups,
1226 		 n_interf + 1);
1227 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1228 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1229 
1230 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1231 	if (!vlabuf)
1232 		return -ENOMEM;
1233 
1234 	f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
1235 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1236 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1237 	interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
1238 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1239 
1240 	parent->default_groups = f_default_groups;
1241 	os_desc_type->ct_owner = owner;
1242 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1243 	f_default_groups[0] = os_desc_group;
1244 
1245 	os_desc_group->default_groups = interface_groups;
1246 	interface_type->ct_item_ops = &interf_item_ops;
1247 	interface_type->ct_group_ops = &interf_grp_ops;
1248 	interface_type->ct_attrs = interf_grp_attrs;
1249 	interface_type->ct_owner = owner;
1250 
1251 	while (n_interf--) {
1252 		struct usb_os_desc *d;
1253 
1254 		d = desc[n_interf];
1255 		d->owner = owner;
1256 		config_group_init_type_name(&d->group, "", interface_type);
1257 		config_item_set_name(&d->group.cg_item, "interface.%s",
1258 				     names[n_interf]);
1259 		interface_groups[n_interf] = &d->group;
1260 	}
1261 
1262 	return 0;
1263 }
1264 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1265 
1266 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1267 {
1268 	WARN_ON(1);
1269 	return -EINVAL;
1270 }
1271 
1272 int composite_dev_prepare(struct usb_composite_driver *composite,
1273 		struct usb_composite_dev *dev);
1274 
1275 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1276 				  struct usb_ep *ep0);
1277 
1278 static void purge_configs_funcs(struct gadget_info *gi)
1279 {
1280 	struct usb_configuration	*c;
1281 
1282 	list_for_each_entry(c, &gi->cdev.configs, list) {
1283 		struct usb_function *f, *tmp;
1284 		struct config_usb_cfg *cfg;
1285 
1286 		cfg = container_of(c, struct config_usb_cfg, c);
1287 
1288 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1289 
1290 			list_move_tail(&f->list, &cfg->func_list);
1291 			if (f->unbind) {
1292 				dev_err(&gi->cdev.gadget->dev, "unbind function"
1293 						" '%s'/%p\n", f->name, f);
1294 				f->unbind(c, f);
1295 			}
1296 		}
1297 		c->next_interface_id = 0;
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 	/* Go through all configs, attach all functions */
1379 	list_for_each_entry(c, &gi->cdev.configs, list) {
1380 		struct config_usb_cfg *cfg;
1381 		struct usb_function *f;
1382 		struct usb_function *tmp;
1383 		struct gadget_config_name *cn;
1384 
1385 		cfg = container_of(c, struct config_usb_cfg, c);
1386 		if (!list_empty(&cfg->string_list)) {
1387 			i = 0;
1388 			list_for_each_entry(cn, &cfg->string_list, list) {
1389 				cfg->gstrings[i] = &cn->stringtab_dev;
1390 				cn->stringtab_dev.strings = &cn->strings;
1391 				cn->strings.s = cn->configuration;
1392 				i++;
1393 			}
1394 			cfg->gstrings[i] = NULL;
1395 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1396 			if (IS_ERR(s)) {
1397 				ret = PTR_ERR(s);
1398 				goto err_comp_cleanup;
1399 			}
1400 			c->iConfiguration = s[0].id;
1401 		}
1402 
1403 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1404 			list_del(&f->list);
1405 			ret = usb_add_function(c, f);
1406 			if (ret) {
1407 				list_add(&f->list, &cfg->func_list);
1408 				goto err_purge_funcs;
1409 			}
1410 		}
1411 		usb_ep_autoconfig_reset(cdev->gadget);
1412 	}
1413 	if (cdev->use_os_string) {
1414 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1415 		if (ret)
1416 			goto err_purge_funcs;
1417 	}
1418 
1419 	usb_ep_autoconfig_reset(cdev->gadget);
1420 	return 0;
1421 
1422 err_purge_funcs:
1423 	purge_configs_funcs(gi);
1424 err_comp_cleanup:
1425 	composite_dev_cleanup(cdev);
1426 	return ret;
1427 }
1428 
1429 static void configfs_composite_unbind(struct usb_gadget *gadget)
1430 {
1431 	struct usb_composite_dev	*cdev;
1432 	struct gadget_info		*gi;
1433 
1434 	/* the gi->lock is hold by the caller */
1435 
1436 	cdev = get_gadget_data(gadget);
1437 	gi = container_of(cdev, struct gadget_info, cdev);
1438 
1439 	purge_configs_funcs(gi);
1440 	composite_dev_cleanup(cdev);
1441 	usb_ep_autoconfig_reset(cdev->gadget);
1442 	cdev->gadget = NULL;
1443 	set_gadget_data(gadget, NULL);
1444 }
1445 
1446 static const struct usb_gadget_driver configfs_driver_template = {
1447 	.bind           = configfs_composite_bind,
1448 	.unbind         = configfs_composite_unbind,
1449 
1450 	.setup          = composite_setup,
1451 	.reset          = composite_disconnect,
1452 	.disconnect     = composite_disconnect,
1453 
1454 	.suspend	= composite_suspend,
1455 	.resume		= composite_resume,
1456 
1457 	.max_speed	= USB_SPEED_SUPER,
1458 	.driver = {
1459 		.owner          = THIS_MODULE,
1460 		.name		= "configfs-gadget",
1461 	},
1462 };
1463 
1464 static struct config_group *gadgets_make(
1465 		struct config_group *group,
1466 		const char *name)
1467 {
1468 	struct gadget_info *gi;
1469 
1470 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1471 	if (!gi)
1472 		return ERR_PTR(-ENOMEM);
1473 
1474 	gi->group.default_groups = gi->default_groups;
1475 	gi->group.default_groups[0] = &gi->functions_group;
1476 	gi->group.default_groups[1] = &gi->configs_group;
1477 	gi->group.default_groups[2] = &gi->strings_group;
1478 	gi->group.default_groups[3] = &gi->os_desc_group;
1479 
1480 	config_group_init_type_name(&gi->functions_group, "functions",
1481 			&functions_type);
1482 	config_group_init_type_name(&gi->configs_group, "configs",
1483 			&config_desc_type);
1484 	config_group_init_type_name(&gi->strings_group, "strings",
1485 			&gadget_strings_strings_type);
1486 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1487 			&os_desc_type);
1488 
1489 	gi->composite.bind = configfs_do_nothing;
1490 	gi->composite.unbind = configfs_do_nothing;
1491 	gi->composite.suspend = NULL;
1492 	gi->composite.resume = NULL;
1493 	gi->composite.max_speed = USB_SPEED_SUPER;
1494 
1495 	mutex_init(&gi->lock);
1496 	INIT_LIST_HEAD(&gi->string_list);
1497 	INIT_LIST_HEAD(&gi->available_func);
1498 
1499 	composite_init_dev(&gi->cdev);
1500 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1501 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1502 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1503 
1504 	gi->composite.gadget_driver = configfs_driver_template;
1505 
1506 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1507 	gi->composite.name = gi->composite.gadget_driver.function;
1508 
1509 	if (!gi->composite.gadget_driver.function)
1510 		goto err;
1511 
1512 #ifdef CONFIG_USB_OTG
1513 	gi->otg.bLength = sizeof(struct usb_otg_descriptor);
1514 	gi->otg.bDescriptorType = USB_DT_OTG;
1515 	gi->otg.bmAttributes = USB_OTG_SRP | USB_OTG_HNP;
1516 #endif
1517 
1518 	config_group_init_type_name(&gi->group, name,
1519 				&gadget_root_type);
1520 	return &gi->group;
1521 err:
1522 	kfree(gi);
1523 	return ERR_PTR(-ENOMEM);
1524 }
1525 
1526 static void gadgets_drop(struct config_group *group, struct config_item *item)
1527 {
1528 	config_item_put(item);
1529 }
1530 
1531 static struct configfs_group_operations gadgets_ops = {
1532 	.make_group     = &gadgets_make,
1533 	.drop_item      = &gadgets_drop,
1534 };
1535 
1536 static struct config_item_type gadgets_type = {
1537 	.ct_group_ops   = &gadgets_ops,
1538 	.ct_owner       = THIS_MODULE,
1539 };
1540 
1541 static struct configfs_subsystem gadget_subsys = {
1542 	.su_group = {
1543 		.cg_item = {
1544 			.ci_namebuf = "usb_gadget",
1545 			.ci_type = &gadgets_type,
1546 		},
1547 	},
1548 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1549 };
1550 
1551 void unregister_gadget_item(struct config_item *item)
1552 {
1553 	struct gadget_info *gi = to_gadget_info(item);
1554 
1555 	unregister_gadget(gi);
1556 }
1557 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1558 
1559 static int __init gadget_cfs_init(void)
1560 {
1561 	int ret;
1562 
1563 	config_group_init(&gadget_subsys.su_group);
1564 
1565 	ret = configfs_register_subsystem(&gadget_subsys);
1566 	return ret;
1567 }
1568 module_init(gadget_cfs_init);
1569 
1570 static void __exit gadget_cfs_exit(void)
1571 {
1572 	configfs_unregister_subsystem(&gadget_subsys);
1573 }
1574 module_exit(gadget_cfs_exit);
1575