xref: /linux/drivers/usb/gadget/configfs.c (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda) 
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 void 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;
441 		}
442 	}
443 	mutex_unlock(&gi->lock);
444 	WARN(1, "Unable to locate function to unbind\n");
445 }
446 
447 static struct configfs_item_operations gadget_config_item_ops = {
448 	.release                = gadget_config_attr_release,
449 	.allow_link             = config_usb_cfg_link,
450 	.drop_link              = config_usb_cfg_unlink,
451 };
452 
453 
454 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
455 		char *page)
456 {
457 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
458 }
459 
460 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
461 		const char *page, size_t len)
462 {
463 	u16 val;
464 	int ret;
465 	ret = kstrtou16(page, 0, &val);
466 	if (ret)
467 		return ret;
468 	if (DIV_ROUND_UP(val, 8) > 0xff)
469 		return -ERANGE;
470 	to_config_usb_cfg(item)->c.MaxPower = val;
471 	return len;
472 }
473 
474 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
475 		char *page)
476 {
477 	return sprintf(page, "0x%02x\n",
478 		to_config_usb_cfg(item)->c.bmAttributes);
479 }
480 
481 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
482 		const char *page, size_t len)
483 {
484 	u8 val;
485 	int ret;
486 	ret = kstrtou8(page, 0, &val);
487 	if (ret)
488 		return ret;
489 	if (!(val & USB_CONFIG_ATT_ONE))
490 		return -EINVAL;
491 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
492 				USB_CONFIG_ATT_WAKEUP))
493 		return -EINVAL;
494 	to_config_usb_cfg(item)->c.bmAttributes = val;
495 	return len;
496 }
497 
498 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
499 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
500 
501 static struct configfs_attribute *gadget_config_attrs[] = {
502 	&gadget_config_desc_attr_MaxPower,
503 	&gadget_config_desc_attr_bmAttributes,
504 	NULL,
505 };
506 
507 static struct config_item_type gadget_config_type = {
508 	.ct_item_ops	= &gadget_config_item_ops,
509 	.ct_attrs	= gadget_config_attrs,
510 	.ct_owner	= THIS_MODULE,
511 };
512 
513 static struct config_item_type gadget_root_type = {
514 	.ct_item_ops	= &gadget_root_item_ops,
515 	.ct_attrs	= gadget_root_attrs,
516 	.ct_owner	= THIS_MODULE,
517 };
518 
519 static void composite_init_dev(struct usb_composite_dev *cdev)
520 {
521 	spin_lock_init(&cdev->lock);
522 	INIT_LIST_HEAD(&cdev->configs);
523 	INIT_LIST_HEAD(&cdev->gstrings);
524 }
525 
526 static struct config_group *function_make(
527 		struct config_group *group,
528 		const char *name)
529 {
530 	struct gadget_info *gi;
531 	struct usb_function_instance *fi;
532 	char buf[MAX_NAME_LEN];
533 	char *func_name;
534 	char *instance_name;
535 	int ret;
536 
537 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
538 	if (ret >= MAX_NAME_LEN)
539 		return ERR_PTR(-ENAMETOOLONG);
540 
541 	func_name = buf;
542 	instance_name = strchr(func_name, '.');
543 	if (!instance_name) {
544 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
545 		return ERR_PTR(-EINVAL);
546 	}
547 	*instance_name = '\0';
548 	instance_name++;
549 
550 	fi = usb_get_function_instance(func_name);
551 	if (IS_ERR(fi))
552 		return ERR_CAST(fi);
553 
554 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
555 	if (ret) {
556 		usb_put_function_instance(fi);
557 		return ERR_PTR(ret);
558 	}
559 	if (fi->set_inst_name) {
560 		ret = fi->set_inst_name(fi, instance_name);
561 		if (ret) {
562 			usb_put_function_instance(fi);
563 			return ERR_PTR(ret);
564 		}
565 	}
566 
567 	gi = container_of(group, struct gadget_info, functions_group);
568 
569 	mutex_lock(&gi->lock);
570 	list_add_tail(&fi->cfs_list, &gi->available_func);
571 	mutex_unlock(&gi->lock);
572 	return &fi->group;
573 }
574 
575 static void function_drop(
576 		struct config_group *group,
577 		struct config_item *item)
578 {
579 	struct usb_function_instance *fi = to_usb_function_instance(item);
580 	struct gadget_info *gi;
581 
582 	gi = container_of(group, struct gadget_info, functions_group);
583 
584 	mutex_lock(&gi->lock);
585 	list_del(&fi->cfs_list);
586 	mutex_unlock(&gi->lock);
587 	config_item_put(item);
588 }
589 
590 static struct configfs_group_operations functions_ops = {
591 	.make_group     = &function_make,
592 	.drop_item      = &function_drop,
593 };
594 
595 static struct config_item_type functions_type = {
596 	.ct_group_ops   = &functions_ops,
597 	.ct_owner       = THIS_MODULE,
598 };
599 
600 GS_STRINGS_RW(gadget_config_name, configuration);
601 
602 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
603 	&gadget_config_name_attr_configuration,
604 	NULL,
605 };
606 
607 static void gadget_config_name_attr_release(struct config_item *item)
608 {
609 	struct gadget_config_name *cn = to_gadget_config_name(item);
610 
611 	kfree(cn->configuration);
612 
613 	list_del(&cn->list);
614 	kfree(cn);
615 }
616 
617 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
618 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
619 
620 static struct config_group *config_desc_make(
621 		struct config_group *group,
622 		const char *name)
623 {
624 	struct gadget_info *gi;
625 	struct config_usb_cfg *cfg;
626 	char buf[MAX_NAME_LEN];
627 	char *num_str;
628 	u8 num;
629 	int ret;
630 
631 	gi = container_of(group, struct gadget_info, configs_group);
632 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
633 	if (ret >= MAX_NAME_LEN)
634 		return ERR_PTR(-ENAMETOOLONG);
635 
636 	num_str = strchr(buf, '.');
637 	if (!num_str) {
638 		pr_err("Unable to locate . in name.bConfigurationValue\n");
639 		return ERR_PTR(-EINVAL);
640 	}
641 
642 	*num_str = '\0';
643 	num_str++;
644 
645 	if (!strlen(buf))
646 		return ERR_PTR(-EINVAL);
647 
648 	ret = kstrtou8(num_str, 0, &num);
649 	if (ret)
650 		return ERR_PTR(ret);
651 
652 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
653 	if (!cfg)
654 		return ERR_PTR(-ENOMEM);
655 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
656 	if (!cfg->c.label) {
657 		ret = -ENOMEM;
658 		goto err;
659 	}
660 	cfg->c.bConfigurationValue = num;
661 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
662 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
663 	INIT_LIST_HEAD(&cfg->string_list);
664 	INIT_LIST_HEAD(&cfg->func_list);
665 
666 	config_group_init_type_name(&cfg->group, name,
667 				&gadget_config_type);
668 
669 	config_group_init_type_name(&cfg->strings_group, "strings",
670 			&gadget_config_name_strings_type);
671 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
672 
673 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
674 	if (ret)
675 		goto err;
676 
677 	return &cfg->group;
678 err:
679 	kfree(cfg->c.label);
680 	kfree(cfg);
681 	return ERR_PTR(ret);
682 }
683 
684 static void config_desc_drop(
685 		struct config_group *group,
686 		struct config_item *item)
687 {
688 	config_item_put(item);
689 }
690 
691 static struct configfs_group_operations config_desc_ops = {
692 	.make_group     = &config_desc_make,
693 	.drop_item      = &config_desc_drop,
694 };
695 
696 static struct config_item_type config_desc_type = {
697 	.ct_group_ops   = &config_desc_ops,
698 	.ct_owner       = THIS_MODULE,
699 };
700 
701 GS_STRINGS_RW(gadget_strings, manufacturer);
702 GS_STRINGS_RW(gadget_strings, product);
703 GS_STRINGS_RW(gadget_strings, serialnumber);
704 
705 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
706 	&gadget_strings_attr_manufacturer,
707 	&gadget_strings_attr_product,
708 	&gadget_strings_attr_serialnumber,
709 	NULL,
710 };
711 
712 static void gadget_strings_attr_release(struct config_item *item)
713 {
714 	struct gadget_strings *gs = to_gadget_strings(item);
715 
716 	kfree(gs->manufacturer);
717 	kfree(gs->product);
718 	kfree(gs->serialnumber);
719 
720 	list_del(&gs->list);
721 	kfree(gs);
722 }
723 
724 USB_CONFIG_STRING_RW_OPS(gadget_strings);
725 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
726 
727 static inline struct os_desc *to_os_desc(struct config_item *item)
728 {
729 	return container_of(to_config_group(item), struct os_desc, group);
730 }
731 
732 static inline struct gadget_info *os_desc_item_to_gadget_info(
733 		struct config_item *item)
734 {
735 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
736 }
737 
738 static ssize_t os_desc_use_show(struct config_item *item, char *page)
739 {
740 	return sprintf(page, "%d",
741 			os_desc_item_to_gadget_info(item)->use_os_desc);
742 }
743 
744 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
745 				 size_t len)
746 {
747 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
748 	int ret;
749 	bool use;
750 
751 	mutex_lock(&gi->lock);
752 	ret = strtobool(page, &use);
753 	if (!ret) {
754 		gi->use_os_desc = use;
755 		ret = len;
756 	}
757 	mutex_unlock(&gi->lock);
758 
759 	return ret;
760 }
761 
762 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
763 {
764 	return sprintf(page, "%d",
765 			os_desc_item_to_gadget_info(item)->b_vendor_code);
766 }
767 
768 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
769 					   const char *page, size_t len)
770 {
771 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
772 	int ret;
773 	u8 b_vendor_code;
774 
775 	mutex_lock(&gi->lock);
776 	ret = kstrtou8(page, 0, &b_vendor_code);
777 	if (!ret) {
778 		gi->b_vendor_code = b_vendor_code;
779 		ret = len;
780 	}
781 	mutex_unlock(&gi->lock);
782 
783 	return ret;
784 }
785 
786 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
787 {
788 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
789 
790 	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
791 	return OS_STRING_QW_SIGN_LEN;
792 }
793 
794 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
795 				     size_t len)
796 {
797 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
798 	int res, l;
799 
800 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
801 	if (page[l - 1] == '\n')
802 		--l;
803 
804 	mutex_lock(&gi->lock);
805 	res = utf8s_to_utf16s(page, l,
806 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
807 			      OS_STRING_QW_SIGN_LEN);
808 	if (res > 0)
809 		res = len;
810 	mutex_unlock(&gi->lock);
811 
812 	return res;
813 }
814 
815 CONFIGFS_ATTR(os_desc_, use);
816 CONFIGFS_ATTR(os_desc_, b_vendor_code);
817 CONFIGFS_ATTR(os_desc_, qw_sign);
818 
819 static struct configfs_attribute *os_desc_attrs[] = {
820 	&os_desc_attr_use,
821 	&os_desc_attr_b_vendor_code,
822 	&os_desc_attr_qw_sign,
823 	NULL,
824 };
825 
826 static void os_desc_attr_release(struct config_item *item)
827 {
828 	struct os_desc *os_desc = to_os_desc(item);
829 	kfree(os_desc);
830 }
831 
832 static int os_desc_link(struct config_item *os_desc_ci,
833 			struct config_item *usb_cfg_ci)
834 {
835 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
836 					struct gadget_info, os_desc_group);
837 	struct usb_composite_dev *cdev = &gi->cdev;
838 	struct config_usb_cfg *c_target =
839 		container_of(to_config_group(usb_cfg_ci),
840 			     struct config_usb_cfg, group);
841 	struct usb_configuration *c;
842 	int ret;
843 
844 	mutex_lock(&gi->lock);
845 	list_for_each_entry(c, &cdev->configs, list) {
846 		if (c == &c_target->c)
847 			break;
848 	}
849 	if (c != &c_target->c) {
850 		ret = -EINVAL;
851 		goto out;
852 	}
853 
854 	if (cdev->os_desc_config) {
855 		ret = -EBUSY;
856 		goto out;
857 	}
858 
859 	cdev->os_desc_config = &c_target->c;
860 	ret = 0;
861 
862 out:
863 	mutex_unlock(&gi->lock);
864 	return ret;
865 }
866 
867 static void os_desc_unlink(struct config_item *os_desc_ci,
868 			  struct config_item *usb_cfg_ci)
869 {
870 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
871 					struct gadget_info, os_desc_group);
872 	struct usb_composite_dev *cdev = &gi->cdev;
873 
874 	mutex_lock(&gi->lock);
875 	if (gi->composite.gadget_driver.udc_name)
876 		unregister_gadget(gi);
877 	cdev->os_desc_config = NULL;
878 	WARN_ON(gi->composite.gadget_driver.udc_name);
879 	mutex_unlock(&gi->lock);
880 }
881 
882 static struct configfs_item_operations os_desc_ops = {
883 	.release                = os_desc_attr_release,
884 	.allow_link		= os_desc_link,
885 	.drop_link		= os_desc_unlink,
886 };
887 
888 static struct config_item_type os_desc_type = {
889 	.ct_item_ops	= &os_desc_ops,
890 	.ct_attrs	= os_desc_attrs,
891 	.ct_owner	= THIS_MODULE,
892 };
893 
894 static inline struct usb_os_desc_ext_prop
895 *to_usb_os_desc_ext_prop(struct config_item *item)
896 {
897 	return container_of(item, struct usb_os_desc_ext_prop, item);
898 }
899 
900 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
901 {
902 	return sprintf(page, "%d", to_usb_os_desc_ext_prop(item)->type);
903 }
904 
905 static ssize_t ext_prop_type_store(struct config_item *item,
906 				   const char *page, size_t len)
907 {
908 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
909 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
910 	u8 type;
911 	int ret;
912 
913 	if (desc->opts_mutex)
914 		mutex_lock(desc->opts_mutex);
915 	ret = kstrtou8(page, 0, &type);
916 	if (ret)
917 		goto end;
918 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
919 		ret = -EINVAL;
920 		goto end;
921 	}
922 
923 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
924 	    ext_prop->type == USB_EXT_PROP_LE32 ||
925 	    ext_prop->type == USB_EXT_PROP_BE32) &&
926 	    (type == USB_EXT_PROP_UNICODE ||
927 	    type == USB_EXT_PROP_UNICODE_ENV ||
928 	    type == USB_EXT_PROP_UNICODE_LINK))
929 		ext_prop->data_len <<= 1;
930 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
931 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
932 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
933 		   (type == USB_EXT_PROP_BINARY ||
934 		   type == USB_EXT_PROP_LE32 ||
935 		   type == USB_EXT_PROP_BE32))
936 		ext_prop->data_len >>= 1;
937 	ext_prop->type = type;
938 	ret = len;
939 
940 end:
941 	if (desc->opts_mutex)
942 		mutex_unlock(desc->opts_mutex);
943 	return ret;
944 }
945 
946 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
947 {
948 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
949 	int len = ext_prop->data_len;
950 
951 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
952 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
953 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
954 		len >>= 1;
955 	memcpy(page, ext_prop->data, len);
956 
957 	return len;
958 }
959 
960 static ssize_t ext_prop_data_store(struct config_item *item,
961 				   const char *page, size_t len)
962 {
963 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
964 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
965 	char *new_data;
966 	size_t ret_len = len;
967 
968 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
969 		--len;
970 	new_data = kmemdup(page, len, GFP_KERNEL);
971 	if (!new_data)
972 		return -ENOMEM;
973 
974 	if (desc->opts_mutex)
975 		mutex_lock(desc->opts_mutex);
976 	kfree(ext_prop->data);
977 	ext_prop->data = new_data;
978 	desc->ext_prop_len -= ext_prop->data_len;
979 	ext_prop->data_len = len;
980 	desc->ext_prop_len += ext_prop->data_len;
981 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
982 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
983 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
984 		desc->ext_prop_len -= ext_prop->data_len;
985 		ext_prop->data_len <<= 1;
986 		ext_prop->data_len += 2;
987 		desc->ext_prop_len += ext_prop->data_len;
988 	}
989 	if (desc->opts_mutex)
990 		mutex_unlock(desc->opts_mutex);
991 	return ret_len;
992 }
993 
994 CONFIGFS_ATTR(ext_prop_, type);
995 CONFIGFS_ATTR(ext_prop_, data);
996 
997 static struct configfs_attribute *ext_prop_attrs[] = {
998 	&ext_prop_attr_type,
999 	&ext_prop_attr_data,
1000 	NULL,
1001 };
1002 
1003 static void usb_os_desc_ext_prop_release(struct config_item *item)
1004 {
1005 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1006 
1007 	kfree(ext_prop); /* frees a whole chunk */
1008 }
1009 
1010 static struct configfs_item_operations ext_prop_ops = {
1011 	.release		= usb_os_desc_ext_prop_release,
1012 };
1013 
1014 static struct config_item *ext_prop_make(
1015 		struct config_group *group,
1016 		const char *name)
1017 {
1018 	struct usb_os_desc_ext_prop *ext_prop;
1019 	struct config_item_type *ext_prop_type;
1020 	struct usb_os_desc *desc;
1021 	char *vlabuf;
1022 
1023 	vla_group(data_chunk);
1024 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1025 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1026 
1027 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1028 	if (!vlabuf)
1029 		return ERR_PTR(-ENOMEM);
1030 
1031 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1032 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1033 
1034 	desc = container_of(group, struct usb_os_desc, group);
1035 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1036 	ext_prop_type->ct_attrs = ext_prop_attrs;
1037 	ext_prop_type->ct_owner = desc->owner;
1038 
1039 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1040 
1041 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1042 	if (!ext_prop->name) {
1043 		kfree(vlabuf);
1044 		return ERR_PTR(-ENOMEM);
1045 	}
1046 	desc->ext_prop_len += 14;
1047 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1048 	if (desc->opts_mutex)
1049 		mutex_lock(desc->opts_mutex);
1050 	desc->ext_prop_len += ext_prop->name_len;
1051 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1052 	++desc->ext_prop_count;
1053 	if (desc->opts_mutex)
1054 		mutex_unlock(desc->opts_mutex);
1055 
1056 	return &ext_prop->item;
1057 }
1058 
1059 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1060 {
1061 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1062 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1063 
1064 	if (desc->opts_mutex)
1065 		mutex_lock(desc->opts_mutex);
1066 	list_del(&ext_prop->entry);
1067 	--desc->ext_prop_count;
1068 	kfree(ext_prop->name);
1069 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1070 	if (desc->opts_mutex)
1071 		mutex_unlock(desc->opts_mutex);
1072 	config_item_put(item);
1073 }
1074 
1075 static struct configfs_group_operations interf_grp_ops = {
1076 	.make_item	= &ext_prop_make,
1077 	.drop_item	= &ext_prop_drop,
1078 };
1079 
1080 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1081 					     char *page)
1082 {
1083 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1084 	return 8;
1085 }
1086 
1087 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1088 					      const char *page, size_t len)
1089 {
1090 	struct usb_os_desc *desc = to_usb_os_desc(item);
1091 	int l;
1092 
1093 	l = min_t(int, 8, len);
1094 	if (page[l - 1] == '\n')
1095 		--l;
1096 	if (desc->opts_mutex)
1097 		mutex_lock(desc->opts_mutex);
1098 	memcpy(desc->ext_compat_id, page, l);
1099 
1100 	if (desc->opts_mutex)
1101 		mutex_unlock(desc->opts_mutex);
1102 
1103 	return len;
1104 }
1105 
1106 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1107 						 char *page)
1108 {
1109 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1110 	return 8;
1111 }
1112 
1113 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1114 						  const char *page, size_t len)
1115 {
1116 	struct usb_os_desc *desc = to_usb_os_desc(item);
1117 	int l;
1118 
1119 	l = min_t(int, 8, len);
1120 	if (page[l - 1] == '\n')
1121 		--l;
1122 	if (desc->opts_mutex)
1123 		mutex_lock(desc->opts_mutex);
1124 	memcpy(desc->ext_compat_id + 8, page, l);
1125 
1126 	if (desc->opts_mutex)
1127 		mutex_unlock(desc->opts_mutex);
1128 
1129 	return len;
1130 }
1131 
1132 CONFIGFS_ATTR(interf_grp_, compatible_id);
1133 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1134 
1135 static struct configfs_attribute *interf_grp_attrs[] = {
1136 	&interf_grp_attr_compatible_id,
1137 	&interf_grp_attr_sub_compatible_id,
1138 	NULL
1139 };
1140 
1141 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1142 				   int n_interf,
1143 				   struct usb_os_desc **desc,
1144 				   char **names,
1145 				   struct module *owner)
1146 {
1147 	struct config_group *os_desc_group;
1148 	struct config_item_type *os_desc_type, *interface_type;
1149 
1150 	vla_group(data_chunk);
1151 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1152 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1153 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1154 
1155 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1156 	if (!vlabuf)
1157 		return -ENOMEM;
1158 
1159 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1160 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1161 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1162 
1163 	os_desc_type->ct_owner = owner;
1164 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1165 	configfs_add_default_group(os_desc_group, parent);
1166 
1167 	interface_type->ct_group_ops = &interf_grp_ops;
1168 	interface_type->ct_attrs = interf_grp_attrs;
1169 	interface_type->ct_owner = owner;
1170 
1171 	while (n_interf--) {
1172 		struct usb_os_desc *d;
1173 
1174 		d = desc[n_interf];
1175 		d->owner = owner;
1176 		config_group_init_type_name(&d->group, "", interface_type);
1177 		config_item_set_name(&d->group.cg_item, "interface.%s",
1178 				     names[n_interf]);
1179 		configfs_add_default_group(&d->group, os_desc_group);
1180 	}
1181 
1182 	return 0;
1183 }
1184 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1185 
1186 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1187 {
1188 	WARN_ON(1);
1189 	return -EINVAL;
1190 }
1191 
1192 int composite_dev_prepare(struct usb_composite_driver *composite,
1193 		struct usb_composite_dev *dev);
1194 
1195 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1196 				  struct usb_ep *ep0);
1197 
1198 static void purge_configs_funcs(struct gadget_info *gi)
1199 {
1200 	struct usb_configuration	*c;
1201 
1202 	list_for_each_entry(c, &gi->cdev.configs, list) {
1203 		struct usb_function *f, *tmp;
1204 		struct config_usb_cfg *cfg;
1205 
1206 		cfg = container_of(c, struct config_usb_cfg, c);
1207 
1208 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1209 
1210 			list_move_tail(&f->list, &cfg->func_list);
1211 			if (f->unbind) {
1212 				dev_dbg(&gi->cdev.gadget->dev,
1213 				         "unbind function '%s'/%p\n",
1214 				         f->name, f);
1215 				f->unbind(c, f);
1216 			}
1217 		}
1218 		c->next_interface_id = 0;
1219 		memset(c->interface, 0, sizeof(c->interface));
1220 		c->superspeed_plus = 0;
1221 		c->superspeed = 0;
1222 		c->highspeed = 0;
1223 		c->fullspeed = 0;
1224 	}
1225 }
1226 
1227 static int configfs_composite_bind(struct usb_gadget *gadget,
1228 		struct usb_gadget_driver *gdriver)
1229 {
1230 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1231 	struct gadget_info		*gi = container_of(composite,
1232 						struct gadget_info, composite);
1233 	struct usb_composite_dev	*cdev = &gi->cdev;
1234 	struct usb_configuration	*c;
1235 	struct usb_string		*s;
1236 	unsigned			i;
1237 	int				ret;
1238 
1239 	/* the gi->lock is hold by the caller */
1240 	cdev->gadget = gadget;
1241 	set_gadget_data(gadget, cdev);
1242 	ret = composite_dev_prepare(composite, cdev);
1243 	if (ret)
1244 		return ret;
1245 	/* and now the gadget bind */
1246 	ret = -EINVAL;
1247 
1248 	if (list_empty(&gi->cdev.configs)) {
1249 		pr_err("Need at least one configuration in %s.\n",
1250 				gi->composite.name);
1251 		goto err_comp_cleanup;
1252 	}
1253 
1254 
1255 	list_for_each_entry(c, &gi->cdev.configs, list) {
1256 		struct config_usb_cfg *cfg;
1257 
1258 		cfg = container_of(c, struct config_usb_cfg, c);
1259 		if (list_empty(&cfg->func_list)) {
1260 			pr_err("Config %s/%d of %s needs at least one function.\n",
1261 			      c->label, c->bConfigurationValue,
1262 			      gi->composite.name);
1263 			goto err_comp_cleanup;
1264 		}
1265 	}
1266 
1267 	/* init all strings */
1268 	if (!list_empty(&gi->string_list)) {
1269 		struct gadget_strings *gs;
1270 
1271 		i = 0;
1272 		list_for_each_entry(gs, &gi->string_list, list) {
1273 
1274 			gi->gstrings[i] = &gs->stringtab_dev;
1275 			gs->stringtab_dev.strings = gs->strings;
1276 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1277 				gs->manufacturer;
1278 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1279 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1280 			i++;
1281 		}
1282 		gi->gstrings[i] = NULL;
1283 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1284 				USB_GADGET_FIRST_AVAIL_IDX);
1285 		if (IS_ERR(s)) {
1286 			ret = PTR_ERR(s);
1287 			goto err_comp_cleanup;
1288 		}
1289 
1290 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1291 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1292 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1293 	}
1294 
1295 	if (gi->use_os_desc) {
1296 		cdev->use_os_string = true;
1297 		cdev->b_vendor_code = gi->b_vendor_code;
1298 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1299 	}
1300 
1301 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1302 		struct usb_descriptor_header *usb_desc;
1303 
1304 		usb_desc = usb_otg_descriptor_alloc(gadget);
1305 		if (!usb_desc) {
1306 			ret = -ENOMEM;
1307 			goto err_comp_cleanup;
1308 		}
1309 		usb_otg_descriptor_init(gadget, usb_desc);
1310 		otg_desc[0] = usb_desc;
1311 		otg_desc[1] = NULL;
1312 	}
1313 
1314 	/* Go through all configs, attach all functions */
1315 	list_for_each_entry(c, &gi->cdev.configs, list) {
1316 		struct config_usb_cfg *cfg;
1317 		struct usb_function *f;
1318 		struct usb_function *tmp;
1319 		struct gadget_config_name *cn;
1320 
1321 		if (gadget_is_otg(gadget))
1322 			c->descriptors = otg_desc;
1323 
1324 		cfg = container_of(c, struct config_usb_cfg, c);
1325 		if (!list_empty(&cfg->string_list)) {
1326 			i = 0;
1327 			list_for_each_entry(cn, &cfg->string_list, list) {
1328 				cfg->gstrings[i] = &cn->stringtab_dev;
1329 				cn->stringtab_dev.strings = &cn->strings;
1330 				cn->strings.s = cn->configuration;
1331 				i++;
1332 			}
1333 			cfg->gstrings[i] = NULL;
1334 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1335 			if (IS_ERR(s)) {
1336 				ret = PTR_ERR(s);
1337 				goto err_comp_cleanup;
1338 			}
1339 			c->iConfiguration = s[0].id;
1340 		}
1341 
1342 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1343 			list_del(&f->list);
1344 			ret = usb_add_function(c, f);
1345 			if (ret) {
1346 				list_add(&f->list, &cfg->func_list);
1347 				goto err_purge_funcs;
1348 			}
1349 		}
1350 		usb_ep_autoconfig_reset(cdev->gadget);
1351 	}
1352 	if (cdev->use_os_string) {
1353 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1354 		if (ret)
1355 			goto err_purge_funcs;
1356 	}
1357 
1358 	usb_ep_autoconfig_reset(cdev->gadget);
1359 	return 0;
1360 
1361 err_purge_funcs:
1362 	purge_configs_funcs(gi);
1363 err_comp_cleanup:
1364 	composite_dev_cleanup(cdev);
1365 	return ret;
1366 }
1367 
1368 static void configfs_composite_unbind(struct usb_gadget *gadget)
1369 {
1370 	struct usb_composite_dev	*cdev;
1371 	struct gadget_info		*gi;
1372 
1373 	/* the gi->lock is hold by the caller */
1374 
1375 	cdev = get_gadget_data(gadget);
1376 	gi = container_of(cdev, struct gadget_info, cdev);
1377 
1378 	kfree(otg_desc[0]);
1379 	otg_desc[0] = NULL;
1380 	purge_configs_funcs(gi);
1381 	composite_dev_cleanup(cdev);
1382 	usb_ep_autoconfig_reset(cdev->gadget);
1383 	cdev->gadget = NULL;
1384 	set_gadget_data(gadget, NULL);
1385 }
1386 
1387 static const struct usb_gadget_driver configfs_driver_template = {
1388 	.bind           = configfs_composite_bind,
1389 	.unbind         = configfs_composite_unbind,
1390 
1391 	.setup          = composite_setup,
1392 	.reset          = composite_disconnect,
1393 	.disconnect     = composite_disconnect,
1394 
1395 	.suspend	= composite_suspend,
1396 	.resume		= composite_resume,
1397 
1398 	.max_speed	= USB_SPEED_SUPER,
1399 	.driver = {
1400 		.owner          = THIS_MODULE,
1401 		.name		= "configfs-gadget",
1402 	},
1403 	.match_existing_only = 1,
1404 };
1405 
1406 static struct config_group *gadgets_make(
1407 		struct config_group *group,
1408 		const char *name)
1409 {
1410 	struct gadget_info *gi;
1411 
1412 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1413 	if (!gi)
1414 		return ERR_PTR(-ENOMEM);
1415 
1416 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1417 
1418 	config_group_init_type_name(&gi->functions_group, "functions",
1419 			&functions_type);
1420 	configfs_add_default_group(&gi->functions_group, &gi->group);
1421 
1422 	config_group_init_type_name(&gi->configs_group, "configs",
1423 			&config_desc_type);
1424 	configfs_add_default_group(&gi->configs_group, &gi->group);
1425 
1426 	config_group_init_type_name(&gi->strings_group, "strings",
1427 			&gadget_strings_strings_type);
1428 	configfs_add_default_group(&gi->strings_group, &gi->group);
1429 
1430 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1431 			&os_desc_type);
1432 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1433 
1434 	gi->composite.bind = configfs_do_nothing;
1435 	gi->composite.unbind = configfs_do_nothing;
1436 	gi->composite.suspend = NULL;
1437 	gi->composite.resume = NULL;
1438 	gi->composite.max_speed = USB_SPEED_SUPER;
1439 
1440 	mutex_init(&gi->lock);
1441 	INIT_LIST_HEAD(&gi->string_list);
1442 	INIT_LIST_HEAD(&gi->available_func);
1443 
1444 	composite_init_dev(&gi->cdev);
1445 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1446 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1447 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1448 
1449 	gi->composite.gadget_driver = configfs_driver_template;
1450 
1451 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1452 	gi->composite.name = gi->composite.gadget_driver.function;
1453 
1454 	if (!gi->composite.gadget_driver.function)
1455 		goto err;
1456 
1457 	return &gi->group;
1458 err:
1459 	kfree(gi);
1460 	return ERR_PTR(-ENOMEM);
1461 }
1462 
1463 static void gadgets_drop(struct config_group *group, struct config_item *item)
1464 {
1465 	config_item_put(item);
1466 }
1467 
1468 static struct configfs_group_operations gadgets_ops = {
1469 	.make_group     = &gadgets_make,
1470 	.drop_item      = &gadgets_drop,
1471 };
1472 
1473 static struct config_item_type gadgets_type = {
1474 	.ct_group_ops   = &gadgets_ops,
1475 	.ct_owner       = THIS_MODULE,
1476 };
1477 
1478 static struct configfs_subsystem gadget_subsys = {
1479 	.su_group = {
1480 		.cg_item = {
1481 			.ci_namebuf = "usb_gadget",
1482 			.ci_type = &gadgets_type,
1483 		},
1484 	},
1485 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1486 };
1487 
1488 void unregister_gadget_item(struct config_item *item)
1489 {
1490 	struct gadget_info *gi = to_gadget_info(item);
1491 
1492 	mutex_lock(&gi->lock);
1493 	unregister_gadget(gi);
1494 	mutex_unlock(&gi->lock);
1495 }
1496 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1497 
1498 static int __init gadget_cfs_init(void)
1499 {
1500 	int ret;
1501 
1502 	config_group_init(&gadget_subsys.su_group);
1503 
1504 	ret = configfs_register_subsystem(&gadget_subsys);
1505 	return ret;
1506 }
1507 module_init(gadget_cfs_init);
1508 
1509 static void __exit gadget_cfs_exit(void)
1510 {
1511 	configfs_unregister_subsystem(&gadget_subsys);
1512 }
1513 module_exit(gadget_cfs_exit);
1514