xref: /openbmc/linux/drivers/usb/gadget/configfs.c (revision 293d5b43) 
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 
53 	struct mutex lock;
54 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
55 	struct list_head string_list;
56 	struct list_head available_func;
57 
58 	struct usb_composite_driver composite;
59 	struct usb_composite_dev cdev;
60 	bool use_os_desc;
61 	char b_vendor_code;
62 	char qw_sign[OS_STRING_QW_SIGN_LEN];
63 };
64 
65 static inline struct gadget_info *to_gadget_info(struct config_item *item)
66 {
67 	 return container_of(to_config_group(item), struct gadget_info, group);
68 }
69 
70 struct config_usb_cfg {
71 	struct config_group group;
72 	struct config_group strings_group;
73 	struct list_head string_list;
74 	struct usb_configuration c;
75 	struct list_head func_list;
76 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
77 };
78 
79 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
80 {
81 	return container_of(to_config_group(item), struct config_usb_cfg,
82 			group);
83 }
84 
85 struct gadget_strings {
86 	struct usb_gadget_strings stringtab_dev;
87 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
88 	char *manufacturer;
89 	char *product;
90 	char *serialnumber;
91 
92 	struct config_group group;
93 	struct list_head list;
94 };
95 
96 struct os_desc {
97 	struct config_group group;
98 };
99 
100 struct gadget_config_name {
101 	struct usb_gadget_strings stringtab_dev;
102 	struct usb_string strings;
103 	char *configuration;
104 
105 	struct config_group group;
106 	struct list_head list;
107 };
108 
109 static int usb_string_copy(const char *s, char **s_copy)
110 {
111 	int ret;
112 	char *str;
113 	char *copy = *s_copy;
114 	ret = strlen(s);
115 	if (ret > 126)
116 		return -EOVERFLOW;
117 
118 	str = kstrdup(s, GFP_KERNEL);
119 	if (!str)
120 		return -ENOMEM;
121 	if (str[ret - 1] == '\n')
122 		str[ret - 1] = '\0';
123 	kfree(copy);
124 	*s_copy = str;
125 	return 0;
126 }
127 
128 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
129 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
130 			char *page)	\
131 {	\
132 	return sprintf(page, "0x%02x\n", \
133 		to_gadget_info(item)->cdev.desc.__name); \
134 }
135 
136 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
137 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
138 			char *page)	\
139 {	\
140 	return sprintf(page, "0x%04x\n", \
141 		le16_to_cpup(&to_gadget_info(item)->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 config_item *item, \
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 	to_gadget_info(item)->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 config_item *item, \
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 	to_gadget_info(item)->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 config_item *item,
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 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
211 	return len;
212 }
213 
214 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
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 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
228 	return len;
229 }
230 
231 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
232 {
233 	char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;
234 
235 	return sprintf(page, "%s\n", udc_name ?: "");
236 }
237 
238 static int unregister_gadget(struct gadget_info *gi)
239 {
240 	int ret;
241 
242 	if (!gi->composite.gadget_driver.udc_name)
243 		return -ENODEV;
244 
245 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
246 	if (ret)
247 		return ret;
248 	kfree(gi->composite.gadget_driver.udc_name);
249 	gi->composite.gadget_driver.udc_name = NULL;
250 	return 0;
251 }
252 
253 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
254 		const char *page, size_t len)
255 {
256 	struct gadget_info *gi = to_gadget_info(item);
257 	char *name;
258 	int ret;
259 
260 	name = kstrdup(page, GFP_KERNEL);
261 	if (!name)
262 		return -ENOMEM;
263 	if (name[len - 1] == '\n')
264 		name[len - 1] = '\0';
265 
266 	mutex_lock(&gi->lock);
267 
268 	if (!strlen(name)) {
269 		ret = unregister_gadget(gi);
270 		if (ret)
271 			goto err;
272 	} else {
273 		if (gi->composite.gadget_driver.udc_name) {
274 			ret = -EBUSY;
275 			goto err;
276 		}
277 		gi->composite.gadget_driver.udc_name = name;
278 		ret = usb_gadget_probe_driver(&gi->composite.gadget_driver);
279 		if (ret) {
280 			gi->composite.gadget_driver.udc_name = NULL;
281 			goto err;
282 		}
283 	}
284 	mutex_unlock(&gi->lock);
285 	return len;
286 err:
287 	kfree(name);
288 	mutex_unlock(&gi->lock);
289 	return ret;
290 }
291 
292 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
293 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
294 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
295 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
296 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
297 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
298 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
299 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
300 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
301 
302 static struct configfs_attribute *gadget_root_attrs[] = {
303 	&gadget_dev_desc_attr_bDeviceClass,
304 	&gadget_dev_desc_attr_bDeviceSubClass,
305 	&gadget_dev_desc_attr_bDeviceProtocol,
306 	&gadget_dev_desc_attr_bMaxPacketSize0,
307 	&gadget_dev_desc_attr_idVendor,
308 	&gadget_dev_desc_attr_idProduct,
309 	&gadget_dev_desc_attr_bcdDevice,
310 	&gadget_dev_desc_attr_bcdUSB,
311 	&gadget_dev_desc_attr_UDC,
312 	NULL,
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 usb_function_instance *to_usb_function_instance(
329 		struct config_item *item)
330 {
331 	 return container_of(to_config_group(item),
332 			 struct usb_function_instance, group);
333 }
334 
335 static void gadget_info_attr_release(struct config_item *item)
336 {
337 	struct gadget_info *gi = to_gadget_info(item);
338 
339 	WARN_ON(!list_empty(&gi->cdev.configs));
340 	WARN_ON(!list_empty(&gi->string_list));
341 	WARN_ON(!list_empty(&gi->available_func));
342 	kfree(gi->composite.gadget_driver.function);
343 	kfree(gi);
344 }
345 
346 static struct configfs_item_operations gadget_root_item_ops = {
347 	.release                = gadget_info_attr_release,
348 };
349 
350 static void gadget_config_attr_release(struct config_item *item)
351 {
352 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
353 
354 	WARN_ON(!list_empty(&cfg->c.functions));
355 	list_del(&cfg->c.list);
356 	kfree(cfg->c.label);
357 	kfree(cfg);
358 }
359 
360 static int config_usb_cfg_link(
361 	struct config_item *usb_cfg_ci,
362 	struct config_item *usb_func_ci)
363 {
364 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
365 	struct usb_composite_dev *cdev = cfg->c.cdev;
366 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
367 
368 	struct config_group *group = to_config_group(usb_func_ci);
369 	struct usb_function_instance *fi = container_of(group,
370 			struct usb_function_instance, group);
371 	struct usb_function_instance *a_fi;
372 	struct usb_function *f;
373 	int ret;
374 
375 	mutex_lock(&gi->lock);
376 	/*
377 	 * Make sure this function is from within our _this_ gadget and not
378 	 * from another gadget or a random directory.
379 	 * Also a function instance can only be linked once.
380 	 */
381 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
382 		if (a_fi == fi)
383 			break;
384 	}
385 	if (a_fi != fi) {
386 		ret = -EINVAL;
387 		goto out;
388 	}
389 
390 	list_for_each_entry(f, &cfg->func_list, list) {
391 		if (f->fi == fi) {
392 			ret = -EEXIST;
393 			goto out;
394 		}
395 	}
396 
397 	f = usb_get_function(fi);
398 	if (IS_ERR(f)) {
399 		ret = PTR_ERR(f);
400 		goto out;
401 	}
402 
403 	/* stash the function until we bind it to the gadget */
404 	list_add_tail(&f->list, &cfg->func_list);
405 	ret = 0;
406 out:
407 	mutex_unlock(&gi->lock);
408 	return ret;
409 }
410 
411 static int config_usb_cfg_unlink(
412 	struct config_item *usb_cfg_ci,
413 	struct config_item *usb_func_ci)
414 {
415 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
416 	struct usb_composite_dev *cdev = cfg->c.cdev;
417 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
418 
419 	struct config_group *group = to_config_group(usb_func_ci);
420 	struct usb_function_instance *fi = container_of(group,
421 			struct usb_function_instance, group);
422 	struct usb_function *f;
423 
424 	/*
425 	 * ideally I would like to forbid to unlink functions while a gadget is
426 	 * bound to an UDC. Since this isn't possible at the moment, we simply
427 	 * force an unbind, the function is available here and then we can
428 	 * remove the function.
429 	 */
430 	mutex_lock(&gi->lock);
431 	if (gi->composite.gadget_driver.udc_name)
432 		unregister_gadget(gi);
433 	WARN_ON(gi->composite.gadget_driver.udc_name);
434 
435 	list_for_each_entry(f, &cfg->func_list, list) {
436 		if (f->fi == fi) {
437 			list_del(&f->list);
438 			usb_put_function(f);
439 			mutex_unlock(&gi->lock);
440 			return 0;
441 		}
442 	}
443 	mutex_unlock(&gi->lock);
444 	WARN(1, "Unable to locate function to unbind\n");
445 	return 0;
446 }
447 
448 static struct configfs_item_operations gadget_config_item_ops = {
449 	.release                = gadget_config_attr_release,
450 	.allow_link             = config_usb_cfg_link,
451 	.drop_link              = config_usb_cfg_unlink,
452 };
453 
454 
455 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
456 		char *page)
457 {
458 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
459 }
460 
461 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
462 		const char *page, size_t len)
463 {
464 	u16 val;
465 	int ret;
466 	ret = kstrtou16(page, 0, &val);
467 	if (ret)
468 		return ret;
469 	if (DIV_ROUND_UP(val, 8) > 0xff)
470 		return -ERANGE;
471 	to_config_usb_cfg(item)->c.MaxPower = val;
472 	return len;
473 }
474 
475 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
476 		char *page)
477 {
478 	return sprintf(page, "0x%02x\n",
479 		to_config_usb_cfg(item)->c.bmAttributes);
480 }
481 
482 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
483 		const char *page, size_t len)
484 {
485 	u8 val;
486 	int ret;
487 	ret = kstrtou8(page, 0, &val);
488 	if (ret)
489 		return ret;
490 	if (!(val & USB_CONFIG_ATT_ONE))
491 		return -EINVAL;
492 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
493 				USB_CONFIG_ATT_WAKEUP))
494 		return -EINVAL;
495 	to_config_usb_cfg(item)->c.bmAttributes = val;
496 	return len;
497 }
498 
499 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
500 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
501 
502 static struct configfs_attribute *gadget_config_attrs[] = {
503 	&gadget_config_desc_attr_MaxPower,
504 	&gadget_config_desc_attr_bmAttributes,
505 	NULL,
506 };
507 
508 static struct config_item_type gadget_config_type = {
509 	.ct_item_ops	= &gadget_config_item_ops,
510 	.ct_attrs	= gadget_config_attrs,
511 	.ct_owner	= THIS_MODULE,
512 };
513 
514 static struct config_item_type gadget_root_type = {
515 	.ct_item_ops	= &gadget_root_item_ops,
516 	.ct_attrs	= gadget_root_attrs,
517 	.ct_owner	= THIS_MODULE,
518 };
519 
520 static void composite_init_dev(struct usb_composite_dev *cdev)
521 {
522 	spin_lock_init(&cdev->lock);
523 	INIT_LIST_HEAD(&cdev->configs);
524 	INIT_LIST_HEAD(&cdev->gstrings);
525 }
526 
527 static struct config_group *function_make(
528 		struct config_group *group,
529 		const char *name)
530 {
531 	struct gadget_info *gi;
532 	struct usb_function_instance *fi;
533 	char buf[MAX_NAME_LEN];
534 	char *func_name;
535 	char *instance_name;
536 	int ret;
537 
538 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
539 	if (ret >= MAX_NAME_LEN)
540 		return ERR_PTR(-ENAMETOOLONG);
541 
542 	func_name = buf;
543 	instance_name = strchr(func_name, '.');
544 	if (!instance_name) {
545 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
546 		return ERR_PTR(-EINVAL);
547 	}
548 	*instance_name = '\0';
549 	instance_name++;
550 
551 	fi = usb_get_function_instance(func_name);
552 	if (IS_ERR(fi))
553 		return ERR_CAST(fi);
554 
555 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
556 	if (ret) {
557 		usb_put_function_instance(fi);
558 		return ERR_PTR(ret);
559 	}
560 	if (fi->set_inst_name) {
561 		ret = fi->set_inst_name(fi, instance_name);
562 		if (ret) {
563 			usb_put_function_instance(fi);
564 			return ERR_PTR(ret);
565 		}
566 	}
567 
568 	gi = container_of(group, struct gadget_info, functions_group);
569 
570 	mutex_lock(&gi->lock);
571 	list_add_tail(&fi->cfs_list, &gi->available_func);
572 	mutex_unlock(&gi->lock);
573 	return &fi->group;
574 }
575 
576 static void function_drop(
577 		struct config_group *group,
578 		struct config_item *item)
579 {
580 	struct usb_function_instance *fi = to_usb_function_instance(item);
581 	struct gadget_info *gi;
582 
583 	gi = container_of(group, struct gadget_info, functions_group);
584 
585 	mutex_lock(&gi->lock);
586 	list_del(&fi->cfs_list);
587 	mutex_unlock(&gi->lock);
588 	config_item_put(item);
589 }
590 
591 static struct configfs_group_operations functions_ops = {
592 	.make_group     = &function_make,
593 	.drop_item      = &function_drop,
594 };
595 
596 static struct config_item_type functions_type = {
597 	.ct_group_ops   = &functions_ops,
598 	.ct_owner       = THIS_MODULE,
599 };
600 
601 GS_STRINGS_RW(gadget_config_name, configuration);
602 
603 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
604 	&gadget_config_name_attr_configuration,
605 	NULL,
606 };
607 
608 static void gadget_config_name_attr_release(struct config_item *item)
609 {
610 	struct gadget_config_name *cn = to_gadget_config_name(item);
611 
612 	kfree(cn->configuration);
613 
614 	list_del(&cn->list);
615 	kfree(cn);
616 }
617 
618 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
619 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
620 
621 static struct config_group *config_desc_make(
622 		struct config_group *group,
623 		const char *name)
624 {
625 	struct gadget_info *gi;
626 	struct config_usb_cfg *cfg;
627 	char buf[MAX_NAME_LEN];
628 	char *num_str;
629 	u8 num;
630 	int ret;
631 
632 	gi = container_of(group, struct gadget_info, configs_group);
633 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
634 	if (ret >= MAX_NAME_LEN)
635 		return ERR_PTR(-ENAMETOOLONG);
636 
637 	num_str = strchr(buf, '.');
638 	if (!num_str) {
639 		pr_err("Unable to locate . in name.bConfigurationValue\n");
640 		return ERR_PTR(-EINVAL);
641 	}
642 
643 	*num_str = '\0';
644 	num_str++;
645 
646 	if (!strlen(buf))
647 		return ERR_PTR(-EINVAL);
648 
649 	ret = kstrtou8(num_str, 0, &num);
650 	if (ret)
651 		return ERR_PTR(ret);
652 
653 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
654 	if (!cfg)
655 		return ERR_PTR(-ENOMEM);
656 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
657 	if (!cfg->c.label) {
658 		ret = -ENOMEM;
659 		goto err;
660 	}
661 	cfg->c.bConfigurationValue = num;
662 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
663 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
664 	INIT_LIST_HEAD(&cfg->string_list);
665 	INIT_LIST_HEAD(&cfg->func_list);
666 
667 	config_group_init_type_name(&cfg->group, name,
668 				&gadget_config_type);
669 
670 	config_group_init_type_name(&cfg->strings_group, "strings",
671 			&gadget_config_name_strings_type);
672 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
673 
674 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
675 	if (ret)
676 		goto err;
677 
678 	return &cfg->group;
679 err:
680 	kfree(cfg->c.label);
681 	kfree(cfg);
682 	return ERR_PTR(ret);
683 }
684 
685 static void config_desc_drop(
686 		struct config_group *group,
687 		struct config_item *item)
688 {
689 	config_item_put(item);
690 }
691 
692 static struct configfs_group_operations config_desc_ops = {
693 	.make_group     = &config_desc_make,
694 	.drop_item      = &config_desc_drop,
695 };
696 
697 static struct config_item_type config_desc_type = {
698 	.ct_group_ops   = &config_desc_ops,
699 	.ct_owner       = THIS_MODULE,
700 };
701 
702 GS_STRINGS_RW(gadget_strings, manufacturer);
703 GS_STRINGS_RW(gadget_strings, product);
704 GS_STRINGS_RW(gadget_strings, serialnumber);
705 
706 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
707 	&gadget_strings_attr_manufacturer,
708 	&gadget_strings_attr_product,
709 	&gadget_strings_attr_serialnumber,
710 	NULL,
711 };
712 
713 static void gadget_strings_attr_release(struct config_item *item)
714 {
715 	struct gadget_strings *gs = to_gadget_strings(item);
716 
717 	kfree(gs->manufacturer);
718 	kfree(gs->product);
719 	kfree(gs->serialnumber);
720 
721 	list_del(&gs->list);
722 	kfree(gs);
723 }
724 
725 USB_CONFIG_STRING_RW_OPS(gadget_strings);
726 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
727 
728 static inline struct os_desc *to_os_desc(struct config_item *item)
729 {
730 	return container_of(to_config_group(item), struct os_desc, group);
731 }
732 
733 static inline struct gadget_info *os_desc_item_to_gadget_info(
734 		struct config_item *item)
735 {
736 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
737 }
738 
739 static ssize_t os_desc_use_show(struct config_item *item, char *page)
740 {
741 	return sprintf(page, "%d",
742 			os_desc_item_to_gadget_info(item)->use_os_desc);
743 }
744 
745 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
746 				 size_t len)
747 {
748 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
749 	int ret;
750 	bool use;
751 
752 	mutex_lock(&gi->lock);
753 	ret = strtobool(page, &use);
754 	if (!ret) {
755 		gi->use_os_desc = use;
756 		ret = len;
757 	}
758 	mutex_unlock(&gi->lock);
759 
760 	return ret;
761 }
762 
763 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
764 {
765 	return sprintf(page, "%d",
766 			os_desc_item_to_gadget_info(item)->b_vendor_code);
767 }
768 
769 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
770 					   const char *page, size_t len)
771 {
772 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
773 	int ret;
774 	u8 b_vendor_code;
775 
776 	mutex_lock(&gi->lock);
777 	ret = kstrtou8(page, 0, &b_vendor_code);
778 	if (!ret) {
779 		gi->b_vendor_code = b_vendor_code;
780 		ret = len;
781 	}
782 	mutex_unlock(&gi->lock);
783 
784 	return ret;
785 }
786 
787 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
788 {
789 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
790 
791 	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
792 	return OS_STRING_QW_SIGN_LEN;
793 }
794 
795 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
796 				     size_t len)
797 {
798 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
799 	int res, l;
800 
801 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
802 	if (page[l - 1] == '\n')
803 		--l;
804 
805 	mutex_lock(&gi->lock);
806 	res = utf8s_to_utf16s(page, l,
807 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
808 			      OS_STRING_QW_SIGN_LEN);
809 	if (res > 0)
810 		res = len;
811 	mutex_unlock(&gi->lock);
812 
813 	return res;
814 }
815 
816 CONFIGFS_ATTR(os_desc_, use);
817 CONFIGFS_ATTR(os_desc_, b_vendor_code);
818 CONFIGFS_ATTR(os_desc_, qw_sign);
819 
820 static struct configfs_attribute *os_desc_attrs[] = {
821 	&os_desc_attr_use,
822 	&os_desc_attr_b_vendor_code,
823 	&os_desc_attr_qw_sign,
824 	NULL,
825 };
826 
827 static void os_desc_attr_release(struct config_item *item)
828 {
829 	struct os_desc *os_desc = to_os_desc(item);
830 	kfree(os_desc);
831 }
832 
833 static int os_desc_link(struct config_item *os_desc_ci,
834 			struct config_item *usb_cfg_ci)
835 {
836 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
837 					struct gadget_info, os_desc_group);
838 	struct usb_composite_dev *cdev = &gi->cdev;
839 	struct config_usb_cfg *c_target =
840 		container_of(to_config_group(usb_cfg_ci),
841 			     struct config_usb_cfg, group);
842 	struct usb_configuration *c;
843 	int ret;
844 
845 	mutex_lock(&gi->lock);
846 	list_for_each_entry(c, &cdev->configs, list) {
847 		if (c == &c_target->c)
848 			break;
849 	}
850 	if (c != &c_target->c) {
851 		ret = -EINVAL;
852 		goto out;
853 	}
854 
855 	if (cdev->os_desc_config) {
856 		ret = -EBUSY;
857 		goto out;
858 	}
859 
860 	cdev->os_desc_config = &c_target->c;
861 	ret = 0;
862 
863 out:
864 	mutex_unlock(&gi->lock);
865 	return ret;
866 }
867 
868 static int os_desc_unlink(struct config_item *os_desc_ci,
869 			  struct config_item *usb_cfg_ci)
870 {
871 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
872 					struct gadget_info, os_desc_group);
873 	struct usb_composite_dev *cdev = &gi->cdev;
874 
875 	mutex_lock(&gi->lock);
876 	if (gi->composite.gadget_driver.udc_name)
877 		unregister_gadget(gi);
878 	cdev->os_desc_config = NULL;
879 	WARN_ON(gi->composite.gadget_driver.udc_name);
880 	mutex_unlock(&gi->lock);
881 	return 0;
882 }
883 
884 static struct configfs_item_operations os_desc_ops = {
885 	.release                = os_desc_attr_release,
886 	.allow_link		= os_desc_link,
887 	.drop_link		= os_desc_unlink,
888 };
889 
890 static struct config_item_type os_desc_type = {
891 	.ct_item_ops	= &os_desc_ops,
892 	.ct_attrs	= os_desc_attrs,
893 	.ct_owner	= THIS_MODULE,
894 };
895 
896 static inline struct usb_os_desc_ext_prop
897 *to_usb_os_desc_ext_prop(struct config_item *item)
898 {
899 	return container_of(item, struct usb_os_desc_ext_prop, item);
900 }
901 
902 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
903 {
904 	return sprintf(page, "%d", to_usb_os_desc_ext_prop(item)->type);
905 }
906 
907 static ssize_t ext_prop_type_store(struct config_item *item,
908 				   const char *page, size_t len)
909 {
910 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
911 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
912 	u8 type;
913 	int ret;
914 
915 	if (desc->opts_mutex)
916 		mutex_lock(desc->opts_mutex);
917 	ret = kstrtou8(page, 0, &type);
918 	if (ret)
919 		goto end;
920 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
921 		ret = -EINVAL;
922 		goto end;
923 	}
924 
925 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
926 	    ext_prop->type == USB_EXT_PROP_LE32 ||
927 	    ext_prop->type == USB_EXT_PROP_BE32) &&
928 	    (type == USB_EXT_PROP_UNICODE ||
929 	    type == USB_EXT_PROP_UNICODE_ENV ||
930 	    type == USB_EXT_PROP_UNICODE_LINK))
931 		ext_prop->data_len <<= 1;
932 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
933 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
934 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
935 		   (type == USB_EXT_PROP_BINARY ||
936 		   type == USB_EXT_PROP_LE32 ||
937 		   type == USB_EXT_PROP_BE32))
938 		ext_prop->data_len >>= 1;
939 	ext_prop->type = type;
940 	ret = len;
941 
942 end:
943 	if (desc->opts_mutex)
944 		mutex_unlock(desc->opts_mutex);
945 	return ret;
946 }
947 
948 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
949 {
950 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
951 	int len = ext_prop->data_len;
952 
953 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
954 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
955 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
956 		len >>= 1;
957 	memcpy(page, ext_prop->data, len);
958 
959 	return len;
960 }
961 
962 static ssize_t ext_prop_data_store(struct config_item *item,
963 				   const char *page, size_t len)
964 {
965 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
966 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
967 	char *new_data;
968 	size_t ret_len = len;
969 
970 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
971 		--len;
972 	new_data = kmemdup(page, len, GFP_KERNEL);
973 	if (!new_data)
974 		return -ENOMEM;
975 
976 	if (desc->opts_mutex)
977 		mutex_lock(desc->opts_mutex);
978 	kfree(ext_prop->data);
979 	ext_prop->data = new_data;
980 	desc->ext_prop_len -= ext_prop->data_len;
981 	ext_prop->data_len = len;
982 	desc->ext_prop_len += ext_prop->data_len;
983 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
984 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
985 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
986 		desc->ext_prop_len -= ext_prop->data_len;
987 		ext_prop->data_len <<= 1;
988 		ext_prop->data_len += 2;
989 		desc->ext_prop_len += ext_prop->data_len;
990 	}
991 	if (desc->opts_mutex)
992 		mutex_unlock(desc->opts_mutex);
993 	return ret_len;
994 }
995 
996 CONFIGFS_ATTR(ext_prop_, type);
997 CONFIGFS_ATTR(ext_prop_, data);
998 
999 static struct configfs_attribute *ext_prop_attrs[] = {
1000 	&ext_prop_attr_type,
1001 	&ext_prop_attr_data,
1002 	NULL,
1003 };
1004 
1005 static void usb_os_desc_ext_prop_release(struct config_item *item)
1006 {
1007 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1008 
1009 	kfree(ext_prop); /* frees a whole chunk */
1010 }
1011 
1012 static struct configfs_item_operations ext_prop_ops = {
1013 	.release		= usb_os_desc_ext_prop_release,
1014 };
1015 
1016 static struct config_item *ext_prop_make(
1017 		struct config_group *group,
1018 		const char *name)
1019 {
1020 	struct usb_os_desc_ext_prop *ext_prop;
1021 	struct config_item_type *ext_prop_type;
1022 	struct usb_os_desc *desc;
1023 	char *vlabuf;
1024 
1025 	vla_group(data_chunk);
1026 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1027 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1028 
1029 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1030 	if (!vlabuf)
1031 		return ERR_PTR(-ENOMEM);
1032 
1033 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1034 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1035 
1036 	desc = container_of(group, struct usb_os_desc, group);
1037 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1038 	ext_prop_type->ct_attrs = ext_prop_attrs;
1039 	ext_prop_type->ct_owner = desc->owner;
1040 
1041 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1042 
1043 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1044 	if (!ext_prop->name) {
1045 		kfree(vlabuf);
1046 		return ERR_PTR(-ENOMEM);
1047 	}
1048 	desc->ext_prop_len += 14;
1049 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1050 	if (desc->opts_mutex)
1051 		mutex_lock(desc->opts_mutex);
1052 	desc->ext_prop_len += ext_prop->name_len;
1053 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1054 	++desc->ext_prop_count;
1055 	if (desc->opts_mutex)
1056 		mutex_unlock(desc->opts_mutex);
1057 
1058 	return &ext_prop->item;
1059 }
1060 
1061 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1062 {
1063 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1064 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1065 
1066 	if (desc->opts_mutex)
1067 		mutex_lock(desc->opts_mutex);
1068 	list_del(&ext_prop->entry);
1069 	--desc->ext_prop_count;
1070 	kfree(ext_prop->name);
1071 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1072 	if (desc->opts_mutex)
1073 		mutex_unlock(desc->opts_mutex);
1074 	config_item_put(item);
1075 }
1076 
1077 static struct configfs_group_operations interf_grp_ops = {
1078 	.make_item	= &ext_prop_make,
1079 	.drop_item	= &ext_prop_drop,
1080 };
1081 
1082 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1083 					     char *page)
1084 {
1085 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1086 	return 8;
1087 }
1088 
1089 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1090 					      const char *page, size_t len)
1091 {
1092 	struct usb_os_desc *desc = to_usb_os_desc(item);
1093 	int l;
1094 
1095 	l = min_t(int, 8, len);
1096 	if (page[l - 1] == '\n')
1097 		--l;
1098 	if (desc->opts_mutex)
1099 		mutex_lock(desc->opts_mutex);
1100 	memcpy(desc->ext_compat_id, page, l);
1101 
1102 	if (desc->opts_mutex)
1103 		mutex_unlock(desc->opts_mutex);
1104 
1105 	return len;
1106 }
1107 
1108 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1109 						 char *page)
1110 {
1111 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1112 	return 8;
1113 }
1114 
1115 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1116 						  const char *page, size_t len)
1117 {
1118 	struct usb_os_desc *desc = to_usb_os_desc(item);
1119 	int l;
1120 
1121 	l = min_t(int, 8, len);
1122 	if (page[l - 1] == '\n')
1123 		--l;
1124 	if (desc->opts_mutex)
1125 		mutex_lock(desc->opts_mutex);
1126 	memcpy(desc->ext_compat_id + 8, page, l);
1127 
1128 	if (desc->opts_mutex)
1129 		mutex_unlock(desc->opts_mutex);
1130 
1131 	return len;
1132 }
1133 
1134 CONFIGFS_ATTR(interf_grp_, compatible_id);
1135 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1136 
1137 static struct configfs_attribute *interf_grp_attrs[] = {
1138 	&interf_grp_attr_compatible_id,
1139 	&interf_grp_attr_sub_compatible_id,
1140 	NULL
1141 };
1142 
1143 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1144 				   int n_interf,
1145 				   struct usb_os_desc **desc,
1146 				   char **names,
1147 				   struct module *owner)
1148 {
1149 	struct config_group *os_desc_group;
1150 	struct config_item_type *os_desc_type, *interface_type;
1151 
1152 	vla_group(data_chunk);
1153 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1154 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1155 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1156 
1157 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1158 	if (!vlabuf)
1159 		return -ENOMEM;
1160 
1161 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1162 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1163 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1164 
1165 	os_desc_type->ct_owner = owner;
1166 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1167 	configfs_add_default_group(os_desc_group, parent);
1168 
1169 	interface_type->ct_group_ops = &interf_grp_ops;
1170 	interface_type->ct_attrs = interf_grp_attrs;
1171 	interface_type->ct_owner = owner;
1172 
1173 	while (n_interf--) {
1174 		struct usb_os_desc *d;
1175 
1176 		d = desc[n_interf];
1177 		d->owner = owner;
1178 		config_group_init_type_name(&d->group, "", interface_type);
1179 		config_item_set_name(&d->group.cg_item, "interface.%s",
1180 				     names[n_interf]);
1181 		configfs_add_default_group(&d->group, os_desc_group);
1182 	}
1183 
1184 	return 0;
1185 }
1186 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1187 
1188 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1189 {
1190 	WARN_ON(1);
1191 	return -EINVAL;
1192 }
1193 
1194 int composite_dev_prepare(struct usb_composite_driver *composite,
1195 		struct usb_composite_dev *dev);
1196 
1197 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1198 				  struct usb_ep *ep0);
1199 
1200 static void purge_configs_funcs(struct gadget_info *gi)
1201 {
1202 	struct usb_configuration	*c;
1203 
1204 	list_for_each_entry(c, &gi->cdev.configs, list) {
1205 		struct usb_function *f, *tmp;
1206 		struct config_usb_cfg *cfg;
1207 
1208 		cfg = container_of(c, struct config_usb_cfg, c);
1209 
1210 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1211 
1212 			list_move_tail(&f->list, &cfg->func_list);
1213 			if (f->unbind) {
1214 				dev_err(&gi->cdev.gadget->dev, "unbind function"
1215 						" '%s'/%p\n", f->name, f);
1216 				f->unbind(c, f);
1217 			}
1218 		}
1219 		c->next_interface_id = 0;
1220 		memset(c->interface, 0, sizeof(c->interface));
1221 		c->superspeed_plus = 0;
1222 		c->superspeed = 0;
1223 		c->highspeed = 0;
1224 		c->fullspeed = 0;
1225 	}
1226 }
1227 
1228 static int configfs_composite_bind(struct usb_gadget *gadget,
1229 		struct usb_gadget_driver *gdriver)
1230 {
1231 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1232 	struct gadget_info		*gi = container_of(composite,
1233 						struct gadget_info, composite);
1234 	struct usb_composite_dev	*cdev = &gi->cdev;
1235 	struct usb_configuration	*c;
1236 	struct usb_string		*s;
1237 	unsigned			i;
1238 	int				ret;
1239 
1240 	/* the gi->lock is hold by the caller */
1241 	cdev->gadget = gadget;
1242 	set_gadget_data(gadget, cdev);
1243 	ret = composite_dev_prepare(composite, cdev);
1244 	if (ret)
1245 		return ret;
1246 	/* and now the gadget bind */
1247 	ret = -EINVAL;
1248 
1249 	if (list_empty(&gi->cdev.configs)) {
1250 		pr_err("Need at least one configuration in %s.\n",
1251 				gi->composite.name);
1252 		goto err_comp_cleanup;
1253 	}
1254 
1255 
1256 	list_for_each_entry(c, &gi->cdev.configs, list) {
1257 		struct config_usb_cfg *cfg;
1258 
1259 		cfg = container_of(c, struct config_usb_cfg, c);
1260 		if (list_empty(&cfg->func_list)) {
1261 			pr_err("Config %s/%d of %s needs at least one function.\n",
1262 			      c->label, c->bConfigurationValue,
1263 			      gi->composite.name);
1264 			goto err_comp_cleanup;
1265 		}
1266 	}
1267 
1268 	/* init all strings */
1269 	if (!list_empty(&gi->string_list)) {
1270 		struct gadget_strings *gs;
1271 
1272 		i = 0;
1273 		list_for_each_entry(gs, &gi->string_list, list) {
1274 
1275 			gi->gstrings[i] = &gs->stringtab_dev;
1276 			gs->stringtab_dev.strings = gs->strings;
1277 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1278 				gs->manufacturer;
1279 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1280 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1281 			i++;
1282 		}
1283 		gi->gstrings[i] = NULL;
1284 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1285 				USB_GADGET_FIRST_AVAIL_IDX);
1286 		if (IS_ERR(s)) {
1287 			ret = PTR_ERR(s);
1288 			goto err_comp_cleanup;
1289 		}
1290 
1291 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1292 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1293 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1294 	}
1295 
1296 	if (gi->use_os_desc) {
1297 		cdev->use_os_string = true;
1298 		cdev->b_vendor_code = gi->b_vendor_code;
1299 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1300 	}
1301 
1302 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1303 		struct usb_descriptor_header *usb_desc;
1304 
1305 		usb_desc = usb_otg_descriptor_alloc(gadget);
1306 		if (!usb_desc) {
1307 			ret = -ENOMEM;
1308 			goto err_comp_cleanup;
1309 		}
1310 		usb_otg_descriptor_init(gadget, usb_desc);
1311 		otg_desc[0] = usb_desc;
1312 		otg_desc[1] = NULL;
1313 	}
1314 
1315 	/* Go through all configs, attach all functions */
1316 	list_for_each_entry(c, &gi->cdev.configs, list) {
1317 		struct config_usb_cfg *cfg;
1318 		struct usb_function *f;
1319 		struct usb_function *tmp;
1320 		struct gadget_config_name *cn;
1321 
1322 		if (gadget_is_otg(gadget))
1323 			c->descriptors = otg_desc;
1324 
1325 		cfg = container_of(c, struct config_usb_cfg, c);
1326 		if (!list_empty(&cfg->string_list)) {
1327 			i = 0;
1328 			list_for_each_entry(cn, &cfg->string_list, list) {
1329 				cfg->gstrings[i] = &cn->stringtab_dev;
1330 				cn->stringtab_dev.strings = &cn->strings;
1331 				cn->strings.s = cn->configuration;
1332 				i++;
1333 			}
1334 			cfg->gstrings[i] = NULL;
1335 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1336 			if (IS_ERR(s)) {
1337 				ret = PTR_ERR(s);
1338 				goto err_comp_cleanup;
1339 			}
1340 			c->iConfiguration = s[0].id;
1341 		}
1342 
1343 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1344 			list_del(&f->list);
1345 			ret = usb_add_function(c, f);
1346 			if (ret) {
1347 				list_add(&f->list, &cfg->func_list);
1348 				goto err_purge_funcs;
1349 			}
1350 		}
1351 		usb_ep_autoconfig_reset(cdev->gadget);
1352 	}
1353 	if (cdev->use_os_string) {
1354 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1355 		if (ret)
1356 			goto err_purge_funcs;
1357 	}
1358 
1359 	usb_ep_autoconfig_reset(cdev->gadget);
1360 	return 0;
1361 
1362 err_purge_funcs:
1363 	purge_configs_funcs(gi);
1364 err_comp_cleanup:
1365 	composite_dev_cleanup(cdev);
1366 	return ret;
1367 }
1368 
1369 static void configfs_composite_unbind(struct usb_gadget *gadget)
1370 {
1371 	struct usb_composite_dev	*cdev;
1372 	struct gadget_info		*gi;
1373 
1374 	/* the gi->lock is hold by the caller */
1375 
1376 	cdev = get_gadget_data(gadget);
1377 	gi = container_of(cdev, struct gadget_info, cdev);
1378 
1379 	kfree(otg_desc[0]);
1380 	otg_desc[0] = NULL;
1381 	purge_configs_funcs(gi);
1382 	composite_dev_cleanup(cdev);
1383 	usb_ep_autoconfig_reset(cdev->gadget);
1384 	cdev->gadget = NULL;
1385 	set_gadget_data(gadget, NULL);
1386 }
1387 
1388 static const struct usb_gadget_driver configfs_driver_template = {
1389 	.bind           = configfs_composite_bind,
1390 	.unbind         = configfs_composite_unbind,
1391 
1392 	.setup          = composite_setup,
1393 	.reset          = composite_disconnect,
1394 	.disconnect     = composite_disconnect,
1395 
1396 	.suspend	= composite_suspend,
1397 	.resume		= composite_resume,
1398 
1399 	.max_speed	= USB_SPEED_SUPER,
1400 	.driver = {
1401 		.owner          = THIS_MODULE,
1402 		.name		= "configfs-gadget",
1403 	},
1404 	.match_existing_only = 1,
1405 };
1406 
1407 static struct config_group *gadgets_make(
1408 		struct config_group *group,
1409 		const char *name)
1410 {
1411 	struct gadget_info *gi;
1412 
1413 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1414 	if (!gi)
1415 		return ERR_PTR(-ENOMEM);
1416 
1417 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1418 
1419 	config_group_init_type_name(&gi->functions_group, "functions",
1420 			&functions_type);
1421 	configfs_add_default_group(&gi->functions_group, &gi->group);
1422 
1423 	config_group_init_type_name(&gi->configs_group, "configs",
1424 			&config_desc_type);
1425 	configfs_add_default_group(&gi->configs_group, &gi->group);
1426 
1427 	config_group_init_type_name(&gi->strings_group, "strings",
1428 			&gadget_strings_strings_type);
1429 	configfs_add_default_group(&gi->strings_group, &gi->group);
1430 
1431 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1432 			&os_desc_type);
1433 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1434 
1435 	gi->composite.bind = configfs_do_nothing;
1436 	gi->composite.unbind = configfs_do_nothing;
1437 	gi->composite.suspend = NULL;
1438 	gi->composite.resume = NULL;
1439 	gi->composite.max_speed = USB_SPEED_SUPER;
1440 
1441 	mutex_init(&gi->lock);
1442 	INIT_LIST_HEAD(&gi->string_list);
1443 	INIT_LIST_HEAD(&gi->available_func);
1444 
1445 	composite_init_dev(&gi->cdev);
1446 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1447 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1448 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1449 
1450 	gi->composite.gadget_driver = configfs_driver_template;
1451 
1452 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1453 	gi->composite.name = gi->composite.gadget_driver.function;
1454 
1455 	if (!gi->composite.gadget_driver.function)
1456 		goto err;
1457 
1458 	return &gi->group;
1459 err:
1460 	kfree(gi);
1461 	return ERR_PTR(-ENOMEM);
1462 }
1463 
1464 static void gadgets_drop(struct config_group *group, struct config_item *item)
1465 {
1466 	config_item_put(item);
1467 }
1468 
1469 static struct configfs_group_operations gadgets_ops = {
1470 	.make_group     = &gadgets_make,
1471 	.drop_item      = &gadgets_drop,
1472 };
1473 
1474 static struct config_item_type gadgets_type = {
1475 	.ct_group_ops   = &gadgets_ops,
1476 	.ct_owner       = THIS_MODULE,
1477 };
1478 
1479 static struct configfs_subsystem gadget_subsys = {
1480 	.su_group = {
1481 		.cg_item = {
1482 			.ci_namebuf = "usb_gadget",
1483 			.ci_type = &gadgets_type,
1484 		},
1485 	},
1486 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1487 };
1488 
1489 void unregister_gadget_item(struct config_item *item)
1490 {
1491 	struct gadget_info *gi = to_gadget_info(item);
1492 
1493 	unregister_gadget(gi);
1494 }
1495 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1496 
1497 static int __init gadget_cfs_init(void)
1498 {
1499 	int ret;
1500 
1501 	config_group_init(&gadget_subsys.su_group);
1502 
1503 	ret = configfs_register_subsystem(&gadget_subsys);
1504 	return ret;
1505 }
1506 module_init(gadget_cfs_init);
1507 
1508 static void __exit gadget_cfs_exit(void)
1509 {
1510 	configfs_unregister_subsystem(&gadget_subsys);
1511 }
1512 module_exit(gadget_cfs_exit);
1513