xref: /linux/drivers/usb/gadget/configfs.c (revision 52338415) 
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/configfs.h>
3 #include <linux/module.h>
4 #include <linux/slab.h>
5 #include <linux/device.h>
6 #include <linux/nls.h>
7 #include <linux/usb/composite.h>
8 #include <linux/usb/gadget_configfs.h>
9 #include "configfs.h"
10 #include "u_f.h"
11 #include "u_os_desc.h"
12 
13 int check_user_usb_string(const char *name,
14 		struct usb_gadget_strings *stringtab_dev)
15 {
16 	unsigned primary_lang;
17 	unsigned sub_lang;
18 	u16 num;
19 	int ret;
20 
21 	ret = kstrtou16(name, 0, &num);
22 	if (ret)
23 		return ret;
24 
25 	primary_lang = num & 0x3ff;
26 	sub_lang = num >> 10;
27 
28 	/* simple sanity check for valid langid */
29 	switch (primary_lang) {
30 	case 0:
31 	case 0x62 ... 0xfe:
32 	case 0x100 ... 0x3ff:
33 		return -EINVAL;
34 	}
35 	if (!sub_lang)
36 		return -EINVAL;
37 
38 	stringtab_dev->language = num;
39 	return 0;
40 }
41 
42 #define MAX_NAME_LEN	40
43 #define MAX_USB_STRING_LANGS 2
44 
45 static const struct usb_descriptor_header *otg_desc[2];
46 
47 struct gadget_info {
48 	struct config_group group;
49 	struct config_group functions_group;
50 	struct config_group configs_group;
51 	struct config_group strings_group;
52 	struct config_group os_desc_group;
53 
54 	struct mutex lock;
55 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
56 	struct list_head string_list;
57 	struct list_head available_func;
58 
59 	struct usb_composite_driver composite;
60 	struct usb_composite_dev cdev;
61 	bool use_os_desc;
62 	char b_vendor_code;
63 	char qw_sign[OS_STRING_QW_SIGN_LEN];
64 	spinlock_t spinlock;
65 	bool unbind;
66 };
67 
68 static inline struct gadget_info *to_gadget_info(struct config_item *item)
69 {
70 	 return container_of(to_config_group(item), struct gadget_info, group);
71 }
72 
73 struct config_usb_cfg {
74 	struct config_group group;
75 	struct config_group strings_group;
76 	struct list_head string_list;
77 	struct usb_configuration c;
78 	struct list_head func_list;
79 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
80 };
81 
82 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
83 {
84 	return container_of(to_config_group(item), struct config_usb_cfg,
85 			group);
86 }
87 
88 struct gadget_strings {
89 	struct usb_gadget_strings stringtab_dev;
90 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
91 	char *manufacturer;
92 	char *product;
93 	char *serialnumber;
94 
95 	struct config_group group;
96 	struct list_head list;
97 };
98 
99 struct os_desc {
100 	struct config_group group;
101 };
102 
103 struct gadget_config_name {
104 	struct usb_gadget_strings stringtab_dev;
105 	struct usb_string strings;
106 	char *configuration;
107 
108 	struct config_group group;
109 	struct list_head list;
110 };
111 
112 static int usb_string_copy(const char *s, char **s_copy)
113 {
114 	int ret;
115 	char *str;
116 	char *copy = *s_copy;
117 	ret = strlen(s);
118 	if (ret > 126)
119 		return -EOVERFLOW;
120 
121 	str = kstrdup(s, GFP_KERNEL);
122 	if (!str)
123 		return -ENOMEM;
124 	if (str[ret - 1] == '\n')
125 		str[ret - 1] = '\0';
126 	kfree(copy);
127 	*s_copy = str;
128 	return 0;
129 }
130 
131 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
132 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
133 			char *page)	\
134 {	\
135 	return sprintf(page, "0x%02x\n", \
136 		to_gadget_info(item)->cdev.desc.__name); \
137 }
138 
139 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
140 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
141 			char *page)	\
142 {	\
143 	return sprintf(page, "0x%04x\n", \
144 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
145 }
146 
147 
148 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
149 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
150 		const char *page, size_t len)		\
151 {							\
152 	u8 val;						\
153 	int ret;					\
154 	ret = kstrtou8(page, 0, &val);			\
155 	if (ret)					\
156 		return ret;				\
157 	to_gadget_info(item)->cdev.desc._name = val;	\
158 	return len;					\
159 }
160 
161 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
162 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
163 		const char *page, size_t len)		\
164 {							\
165 	u16 val;					\
166 	int ret;					\
167 	ret = kstrtou16(page, 0, &val);			\
168 	if (ret)					\
169 		return ret;				\
170 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
171 	return len;					\
172 }
173 
174 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
175 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
176 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
177 
178 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
179 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
180 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
181 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
182 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
183 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
184 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
185 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
186 
187 static ssize_t is_valid_bcd(u16 bcd_val)
188 {
189 	if ((bcd_val & 0xf) > 9)
190 		return -EINVAL;
191 	if (((bcd_val >> 4) & 0xf) > 9)
192 		return -EINVAL;
193 	if (((bcd_val >> 8) & 0xf) > 9)
194 		return -EINVAL;
195 	if (((bcd_val >> 12) & 0xf) > 9)
196 		return -EINVAL;
197 	return 0;
198 }
199 
200 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
201 		const char *page, size_t len)
202 {
203 	u16 bcdDevice;
204 	int ret;
205 
206 	ret = kstrtou16(page, 0, &bcdDevice);
207 	if (ret)
208 		return ret;
209 	ret = is_valid_bcd(bcdDevice);
210 	if (ret)
211 		return ret;
212 
213 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
214 	return len;
215 }
216 
217 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
218 		const char *page, size_t len)
219 {
220 	u16 bcdUSB;
221 	int ret;
222 
223 	ret = kstrtou16(page, 0, &bcdUSB);
224 	if (ret)
225 		return ret;
226 	ret = is_valid_bcd(bcdUSB);
227 	if (ret)
228 		return ret;
229 
230 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
231 	return len;
232 }
233 
234 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
235 {
236 	char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;
237 
238 	return sprintf(page, "%s\n", udc_name ?: "");
239 }
240 
241 static int unregister_gadget(struct gadget_info *gi)
242 {
243 	int ret;
244 
245 	if (!gi->composite.gadget_driver.udc_name)
246 		return -ENODEV;
247 
248 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
249 	if (ret)
250 		return ret;
251 	kfree(gi->composite.gadget_driver.udc_name);
252 	gi->composite.gadget_driver.udc_name = NULL;
253 	return 0;
254 }
255 
256 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
257 		const char *page, size_t len)
258 {
259 	struct gadget_info *gi = to_gadget_info(item);
260 	char *name;
261 	int ret;
262 
263 	name = kstrdup(page, GFP_KERNEL);
264 	if (!name)
265 		return -ENOMEM;
266 	if (name[len - 1] == '\n')
267 		name[len - 1] = '\0';
268 
269 	mutex_lock(&gi->lock);
270 
271 	if (!strlen(name)) {
272 		ret = unregister_gadget(gi);
273 		if (ret)
274 			goto err;
275 		kfree(name);
276 	} else {
277 		if (gi->composite.gadget_driver.udc_name) {
278 			ret = -EBUSY;
279 			goto err;
280 		}
281 		gi->composite.gadget_driver.udc_name = name;
282 		ret = usb_gadget_probe_driver(&gi->composite.gadget_driver);
283 		if (ret) {
284 			gi->composite.gadget_driver.udc_name = NULL;
285 			goto err;
286 		}
287 	}
288 	mutex_unlock(&gi->lock);
289 	return len;
290 err:
291 	kfree(name);
292 	mutex_unlock(&gi->lock);
293 	return ret;
294 }
295 
296 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
297 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
298 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
299 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
300 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
301 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
302 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
303 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
304 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
305 
306 static struct configfs_attribute *gadget_root_attrs[] = {
307 	&gadget_dev_desc_attr_bDeviceClass,
308 	&gadget_dev_desc_attr_bDeviceSubClass,
309 	&gadget_dev_desc_attr_bDeviceProtocol,
310 	&gadget_dev_desc_attr_bMaxPacketSize0,
311 	&gadget_dev_desc_attr_idVendor,
312 	&gadget_dev_desc_attr_idProduct,
313 	&gadget_dev_desc_attr_bcdDevice,
314 	&gadget_dev_desc_attr_bcdUSB,
315 	&gadget_dev_desc_attr_UDC,
316 	NULL,
317 };
318 
319 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
320 {
321 	 return container_of(to_config_group(item), struct gadget_strings,
322 			 group);
323 }
324 
325 static inline struct gadget_config_name *to_gadget_config_name(
326 		struct config_item *item)
327 {
328 	 return container_of(to_config_group(item), struct gadget_config_name,
329 			 group);
330 }
331 
332 static inline struct usb_function_instance *to_usb_function_instance(
333 		struct config_item *item)
334 {
335 	 return container_of(to_config_group(item),
336 			 struct usb_function_instance, group);
337 }
338 
339 static void gadget_info_attr_release(struct config_item *item)
340 {
341 	struct gadget_info *gi = to_gadget_info(item);
342 
343 	WARN_ON(!list_empty(&gi->cdev.configs));
344 	WARN_ON(!list_empty(&gi->string_list));
345 	WARN_ON(!list_empty(&gi->available_func));
346 	kfree(gi->composite.gadget_driver.function);
347 	kfree(gi);
348 }
349 
350 static struct configfs_item_operations gadget_root_item_ops = {
351 	.release                = gadget_info_attr_release,
352 };
353 
354 static void gadget_config_attr_release(struct config_item *item)
355 {
356 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
357 
358 	WARN_ON(!list_empty(&cfg->c.functions));
359 	list_del(&cfg->c.list);
360 	kfree(cfg->c.label);
361 	kfree(cfg);
362 }
363 
364 static int config_usb_cfg_link(
365 	struct config_item *usb_cfg_ci,
366 	struct config_item *usb_func_ci)
367 {
368 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
369 	struct usb_composite_dev *cdev = cfg->c.cdev;
370 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
371 
372 	struct config_group *group = to_config_group(usb_func_ci);
373 	struct usb_function_instance *fi = container_of(group,
374 			struct usb_function_instance, group);
375 	struct usb_function_instance *a_fi;
376 	struct usb_function *f;
377 	int ret;
378 
379 	mutex_lock(&gi->lock);
380 	/*
381 	 * Make sure this function is from within our _this_ gadget and not
382 	 * from another gadget or a random directory.
383 	 * Also a function instance can only be linked once.
384 	 */
385 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
386 		if (a_fi == fi)
387 			break;
388 	}
389 	if (a_fi != fi) {
390 		ret = -EINVAL;
391 		goto out;
392 	}
393 
394 	list_for_each_entry(f, &cfg->func_list, list) {
395 		if (f->fi == fi) {
396 			ret = -EEXIST;
397 			goto out;
398 		}
399 	}
400 
401 	f = usb_get_function(fi);
402 	if (IS_ERR(f)) {
403 		ret = PTR_ERR(f);
404 		goto out;
405 	}
406 
407 	/* stash the function until we bind it to the gadget */
408 	list_add_tail(&f->list, &cfg->func_list);
409 	ret = 0;
410 out:
411 	mutex_unlock(&gi->lock);
412 	return ret;
413 }
414 
415 static void config_usb_cfg_unlink(
416 	struct config_item *usb_cfg_ci,
417 	struct config_item *usb_func_ci)
418 {
419 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
420 	struct usb_composite_dev *cdev = cfg->c.cdev;
421 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
422 
423 	struct config_group *group = to_config_group(usb_func_ci);
424 	struct usb_function_instance *fi = container_of(group,
425 			struct usb_function_instance, group);
426 	struct usb_function *f;
427 
428 	/*
429 	 * ideally I would like to forbid to unlink functions while a gadget is
430 	 * bound to an UDC. Since this isn't possible at the moment, we simply
431 	 * force an unbind, the function is available here and then we can
432 	 * remove the function.
433 	 */
434 	mutex_lock(&gi->lock);
435 	if (gi->composite.gadget_driver.udc_name)
436 		unregister_gadget(gi);
437 	WARN_ON(gi->composite.gadget_driver.udc_name);
438 
439 	list_for_each_entry(f, &cfg->func_list, list) {
440 		if (f->fi == fi) {
441 			list_del(&f->list);
442 			usb_put_function(f);
443 			mutex_unlock(&gi->lock);
444 			return;
445 		}
446 	}
447 	mutex_unlock(&gi->lock);
448 	WARN(1, "Unable to locate function to unbind\n");
449 }
450 
451 static struct configfs_item_operations gadget_config_item_ops = {
452 	.release                = gadget_config_attr_release,
453 	.allow_link             = config_usb_cfg_link,
454 	.drop_link              = config_usb_cfg_unlink,
455 };
456 
457 
458 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
459 		char *page)
460 {
461 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
462 }
463 
464 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
465 		const char *page, size_t len)
466 {
467 	u16 val;
468 	int ret;
469 	ret = kstrtou16(page, 0, &val);
470 	if (ret)
471 		return ret;
472 	if (DIV_ROUND_UP(val, 8) > 0xff)
473 		return -ERANGE;
474 	to_config_usb_cfg(item)->c.MaxPower = val;
475 	return len;
476 }
477 
478 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
479 		char *page)
480 {
481 	return sprintf(page, "0x%02x\n",
482 		to_config_usb_cfg(item)->c.bmAttributes);
483 }
484 
485 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
486 		const char *page, size_t len)
487 {
488 	u8 val;
489 	int ret;
490 	ret = kstrtou8(page, 0, &val);
491 	if (ret)
492 		return ret;
493 	if (!(val & USB_CONFIG_ATT_ONE))
494 		return -EINVAL;
495 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
496 				USB_CONFIG_ATT_WAKEUP))
497 		return -EINVAL;
498 	to_config_usb_cfg(item)->c.bmAttributes = val;
499 	return len;
500 }
501 
502 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
503 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
504 
505 static struct configfs_attribute *gadget_config_attrs[] = {
506 	&gadget_config_desc_attr_MaxPower,
507 	&gadget_config_desc_attr_bmAttributes,
508 	NULL,
509 };
510 
511 static const struct config_item_type gadget_config_type = {
512 	.ct_item_ops	= &gadget_config_item_ops,
513 	.ct_attrs	= gadget_config_attrs,
514 	.ct_owner	= THIS_MODULE,
515 };
516 
517 static const struct config_item_type gadget_root_type = {
518 	.ct_item_ops	= &gadget_root_item_ops,
519 	.ct_attrs	= gadget_root_attrs,
520 	.ct_owner	= THIS_MODULE,
521 };
522 
523 static void composite_init_dev(struct usb_composite_dev *cdev)
524 {
525 	spin_lock_init(&cdev->lock);
526 	INIT_LIST_HEAD(&cdev->configs);
527 	INIT_LIST_HEAD(&cdev->gstrings);
528 }
529 
530 static struct config_group *function_make(
531 		struct config_group *group,
532 		const char *name)
533 {
534 	struct gadget_info *gi;
535 	struct usb_function_instance *fi;
536 	char buf[MAX_NAME_LEN];
537 	char *func_name;
538 	char *instance_name;
539 	int ret;
540 
541 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
542 	if (ret >= MAX_NAME_LEN)
543 		return ERR_PTR(-ENAMETOOLONG);
544 
545 	func_name = buf;
546 	instance_name = strchr(func_name, '.');
547 	if (!instance_name) {
548 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
549 		return ERR_PTR(-EINVAL);
550 	}
551 	*instance_name = '\0';
552 	instance_name++;
553 
554 	fi = usb_get_function_instance(func_name);
555 	if (IS_ERR(fi))
556 		return ERR_CAST(fi);
557 
558 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
559 	if (ret) {
560 		usb_put_function_instance(fi);
561 		return ERR_PTR(ret);
562 	}
563 	if (fi->set_inst_name) {
564 		ret = fi->set_inst_name(fi, instance_name);
565 		if (ret) {
566 			usb_put_function_instance(fi);
567 			return ERR_PTR(ret);
568 		}
569 	}
570 
571 	gi = container_of(group, struct gadget_info, functions_group);
572 
573 	mutex_lock(&gi->lock);
574 	list_add_tail(&fi->cfs_list, &gi->available_func);
575 	mutex_unlock(&gi->lock);
576 	return &fi->group;
577 }
578 
579 static void function_drop(
580 		struct config_group *group,
581 		struct config_item *item)
582 {
583 	struct usb_function_instance *fi = to_usb_function_instance(item);
584 	struct gadget_info *gi;
585 
586 	gi = container_of(group, struct gadget_info, functions_group);
587 
588 	mutex_lock(&gi->lock);
589 	list_del(&fi->cfs_list);
590 	mutex_unlock(&gi->lock);
591 	config_item_put(item);
592 }
593 
594 static struct configfs_group_operations functions_ops = {
595 	.make_group     = &function_make,
596 	.drop_item      = &function_drop,
597 };
598 
599 static const struct config_item_type functions_type = {
600 	.ct_group_ops   = &functions_ops,
601 	.ct_owner       = THIS_MODULE,
602 };
603 
604 GS_STRINGS_RW(gadget_config_name, configuration);
605 
606 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
607 	&gadget_config_name_attr_configuration,
608 	NULL,
609 };
610 
611 static void gadget_config_name_attr_release(struct config_item *item)
612 {
613 	struct gadget_config_name *cn = to_gadget_config_name(item);
614 
615 	kfree(cn->configuration);
616 
617 	list_del(&cn->list);
618 	kfree(cn);
619 }
620 
621 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
622 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
623 
624 static struct config_group *config_desc_make(
625 		struct config_group *group,
626 		const char *name)
627 {
628 	struct gadget_info *gi;
629 	struct config_usb_cfg *cfg;
630 	char buf[MAX_NAME_LEN];
631 	char *num_str;
632 	u8 num;
633 	int ret;
634 
635 	gi = container_of(group, struct gadget_info, configs_group);
636 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
637 	if (ret >= MAX_NAME_LEN)
638 		return ERR_PTR(-ENAMETOOLONG);
639 
640 	num_str = strchr(buf, '.');
641 	if (!num_str) {
642 		pr_err("Unable to locate . in name.bConfigurationValue\n");
643 		return ERR_PTR(-EINVAL);
644 	}
645 
646 	*num_str = '\0';
647 	num_str++;
648 
649 	if (!strlen(buf))
650 		return ERR_PTR(-EINVAL);
651 
652 	ret = kstrtou8(num_str, 0, &num);
653 	if (ret)
654 		return ERR_PTR(ret);
655 
656 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
657 	if (!cfg)
658 		return ERR_PTR(-ENOMEM);
659 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
660 	if (!cfg->c.label) {
661 		ret = -ENOMEM;
662 		goto err;
663 	}
664 	cfg->c.bConfigurationValue = num;
665 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
666 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
667 	INIT_LIST_HEAD(&cfg->string_list);
668 	INIT_LIST_HEAD(&cfg->func_list);
669 
670 	config_group_init_type_name(&cfg->group, name,
671 				&gadget_config_type);
672 
673 	config_group_init_type_name(&cfg->strings_group, "strings",
674 			&gadget_config_name_strings_type);
675 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
676 
677 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
678 	if (ret)
679 		goto err;
680 
681 	return &cfg->group;
682 err:
683 	kfree(cfg->c.label);
684 	kfree(cfg);
685 	return ERR_PTR(ret);
686 }
687 
688 static void config_desc_drop(
689 		struct config_group *group,
690 		struct config_item *item)
691 {
692 	config_item_put(item);
693 }
694 
695 static struct configfs_group_operations config_desc_ops = {
696 	.make_group     = &config_desc_make,
697 	.drop_item      = &config_desc_drop,
698 };
699 
700 static const struct config_item_type config_desc_type = {
701 	.ct_group_ops   = &config_desc_ops,
702 	.ct_owner       = THIS_MODULE,
703 };
704 
705 GS_STRINGS_RW(gadget_strings, manufacturer);
706 GS_STRINGS_RW(gadget_strings, product);
707 GS_STRINGS_RW(gadget_strings, serialnumber);
708 
709 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
710 	&gadget_strings_attr_manufacturer,
711 	&gadget_strings_attr_product,
712 	&gadget_strings_attr_serialnumber,
713 	NULL,
714 };
715 
716 static void gadget_strings_attr_release(struct config_item *item)
717 {
718 	struct gadget_strings *gs = to_gadget_strings(item);
719 
720 	kfree(gs->manufacturer);
721 	kfree(gs->product);
722 	kfree(gs->serialnumber);
723 
724 	list_del(&gs->list);
725 	kfree(gs);
726 }
727 
728 USB_CONFIG_STRING_RW_OPS(gadget_strings);
729 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
730 
731 static inline struct os_desc *to_os_desc(struct config_item *item)
732 {
733 	return container_of(to_config_group(item), struct os_desc, group);
734 }
735 
736 static inline struct gadget_info *os_desc_item_to_gadget_info(
737 		struct config_item *item)
738 {
739 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
740 }
741 
742 static ssize_t os_desc_use_show(struct config_item *item, char *page)
743 {
744 	return sprintf(page, "%d\n",
745 			os_desc_item_to_gadget_info(item)->use_os_desc);
746 }
747 
748 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
749 				 size_t len)
750 {
751 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
752 	int ret;
753 	bool use;
754 
755 	mutex_lock(&gi->lock);
756 	ret = strtobool(page, &use);
757 	if (!ret) {
758 		gi->use_os_desc = use;
759 		ret = len;
760 	}
761 	mutex_unlock(&gi->lock);
762 
763 	return ret;
764 }
765 
766 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
767 {
768 	return sprintf(page, "0x%02x\n",
769 			os_desc_item_to_gadget_info(item)->b_vendor_code);
770 }
771 
772 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
773 					   const char *page, size_t len)
774 {
775 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
776 	int ret;
777 	u8 b_vendor_code;
778 
779 	mutex_lock(&gi->lock);
780 	ret = kstrtou8(page, 0, &b_vendor_code);
781 	if (!ret) {
782 		gi->b_vendor_code = b_vendor_code;
783 		ret = len;
784 	}
785 	mutex_unlock(&gi->lock);
786 
787 	return ret;
788 }
789 
790 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
791 {
792 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
793 	int res;
794 
795 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
796 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
797 	page[res++] = '\n';
798 
799 	return res;
800 }
801 
802 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
803 				     size_t len)
804 {
805 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
806 	int res, l;
807 
808 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
809 	if (page[l - 1] == '\n')
810 		--l;
811 
812 	mutex_lock(&gi->lock);
813 	res = utf8s_to_utf16s(page, l,
814 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
815 			      OS_STRING_QW_SIGN_LEN);
816 	if (res > 0)
817 		res = len;
818 	mutex_unlock(&gi->lock);
819 
820 	return res;
821 }
822 
823 CONFIGFS_ATTR(os_desc_, use);
824 CONFIGFS_ATTR(os_desc_, b_vendor_code);
825 CONFIGFS_ATTR(os_desc_, qw_sign);
826 
827 static struct configfs_attribute *os_desc_attrs[] = {
828 	&os_desc_attr_use,
829 	&os_desc_attr_b_vendor_code,
830 	&os_desc_attr_qw_sign,
831 	NULL,
832 };
833 
834 static void os_desc_attr_release(struct config_item *item)
835 {
836 	struct os_desc *os_desc = to_os_desc(item);
837 	kfree(os_desc);
838 }
839 
840 static int os_desc_link(struct config_item *os_desc_ci,
841 			struct config_item *usb_cfg_ci)
842 {
843 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
844 					struct gadget_info, os_desc_group);
845 	struct usb_composite_dev *cdev = &gi->cdev;
846 	struct config_usb_cfg *c_target =
847 		container_of(to_config_group(usb_cfg_ci),
848 			     struct config_usb_cfg, group);
849 	struct usb_configuration *c;
850 	int ret;
851 
852 	mutex_lock(&gi->lock);
853 	list_for_each_entry(c, &cdev->configs, list) {
854 		if (c == &c_target->c)
855 			break;
856 	}
857 	if (c != &c_target->c) {
858 		ret = -EINVAL;
859 		goto out;
860 	}
861 
862 	if (cdev->os_desc_config) {
863 		ret = -EBUSY;
864 		goto out;
865 	}
866 
867 	cdev->os_desc_config = &c_target->c;
868 	ret = 0;
869 
870 out:
871 	mutex_unlock(&gi->lock);
872 	return ret;
873 }
874 
875 static void os_desc_unlink(struct config_item *os_desc_ci,
876 			  struct config_item *usb_cfg_ci)
877 {
878 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
879 					struct gadget_info, os_desc_group);
880 	struct usb_composite_dev *cdev = &gi->cdev;
881 
882 	mutex_lock(&gi->lock);
883 	if (gi->composite.gadget_driver.udc_name)
884 		unregister_gadget(gi);
885 	cdev->os_desc_config = NULL;
886 	WARN_ON(gi->composite.gadget_driver.udc_name);
887 	mutex_unlock(&gi->lock);
888 }
889 
890 static struct configfs_item_operations os_desc_ops = {
891 	.release                = os_desc_attr_release,
892 	.allow_link		= os_desc_link,
893 	.drop_link		= os_desc_unlink,
894 };
895 
896 static struct config_item_type os_desc_type = {
897 	.ct_item_ops	= &os_desc_ops,
898 	.ct_attrs	= os_desc_attrs,
899 	.ct_owner	= THIS_MODULE,
900 };
901 
902 static inline struct usb_os_desc_ext_prop
903 *to_usb_os_desc_ext_prop(struct config_item *item)
904 {
905 	return container_of(item, struct usb_os_desc_ext_prop, item);
906 }
907 
908 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
909 {
910 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
911 }
912 
913 static ssize_t ext_prop_type_store(struct config_item *item,
914 				   const char *page, size_t len)
915 {
916 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
917 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
918 	u8 type;
919 	int ret;
920 
921 	if (desc->opts_mutex)
922 		mutex_lock(desc->opts_mutex);
923 	ret = kstrtou8(page, 0, &type);
924 	if (ret)
925 		goto end;
926 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
927 		ret = -EINVAL;
928 		goto end;
929 	}
930 
931 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
932 	    ext_prop->type == USB_EXT_PROP_LE32 ||
933 	    ext_prop->type == USB_EXT_PROP_BE32) &&
934 	    (type == USB_EXT_PROP_UNICODE ||
935 	    type == USB_EXT_PROP_UNICODE_ENV ||
936 	    type == USB_EXT_PROP_UNICODE_LINK))
937 		ext_prop->data_len <<= 1;
938 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
939 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
940 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
941 		   (type == USB_EXT_PROP_BINARY ||
942 		   type == USB_EXT_PROP_LE32 ||
943 		   type == USB_EXT_PROP_BE32))
944 		ext_prop->data_len >>= 1;
945 	ext_prop->type = type;
946 	ret = len;
947 
948 end:
949 	if (desc->opts_mutex)
950 		mutex_unlock(desc->opts_mutex);
951 	return ret;
952 }
953 
954 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
955 {
956 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
957 	int len = ext_prop->data_len;
958 
959 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
960 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
961 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
962 		len >>= 1;
963 	memcpy(page, ext_prop->data, len);
964 
965 	return len;
966 }
967 
968 static ssize_t ext_prop_data_store(struct config_item *item,
969 				   const char *page, size_t len)
970 {
971 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
972 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
973 	char *new_data;
974 	size_t ret_len = len;
975 
976 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
977 		--len;
978 	new_data = kmemdup(page, len, GFP_KERNEL);
979 	if (!new_data)
980 		return -ENOMEM;
981 
982 	if (desc->opts_mutex)
983 		mutex_lock(desc->opts_mutex);
984 	kfree(ext_prop->data);
985 	ext_prop->data = new_data;
986 	desc->ext_prop_len -= ext_prop->data_len;
987 	ext_prop->data_len = len;
988 	desc->ext_prop_len += ext_prop->data_len;
989 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
990 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
991 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
992 		desc->ext_prop_len -= ext_prop->data_len;
993 		ext_prop->data_len <<= 1;
994 		ext_prop->data_len += 2;
995 		desc->ext_prop_len += ext_prop->data_len;
996 	}
997 	if (desc->opts_mutex)
998 		mutex_unlock(desc->opts_mutex);
999 	return ret_len;
1000 }
1001 
1002 CONFIGFS_ATTR(ext_prop_, type);
1003 CONFIGFS_ATTR(ext_prop_, data);
1004 
1005 static struct configfs_attribute *ext_prop_attrs[] = {
1006 	&ext_prop_attr_type,
1007 	&ext_prop_attr_data,
1008 	NULL,
1009 };
1010 
1011 static void usb_os_desc_ext_prop_release(struct config_item *item)
1012 {
1013 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1014 
1015 	kfree(ext_prop); /* frees a whole chunk */
1016 }
1017 
1018 static struct configfs_item_operations ext_prop_ops = {
1019 	.release		= usb_os_desc_ext_prop_release,
1020 };
1021 
1022 static struct config_item *ext_prop_make(
1023 		struct config_group *group,
1024 		const char *name)
1025 {
1026 	struct usb_os_desc_ext_prop *ext_prop;
1027 	struct config_item_type *ext_prop_type;
1028 	struct usb_os_desc *desc;
1029 	char *vlabuf;
1030 
1031 	vla_group(data_chunk);
1032 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1033 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1034 
1035 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1036 	if (!vlabuf)
1037 		return ERR_PTR(-ENOMEM);
1038 
1039 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1040 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1041 
1042 	desc = container_of(group, struct usb_os_desc, group);
1043 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1044 	ext_prop_type->ct_attrs = ext_prop_attrs;
1045 	ext_prop_type->ct_owner = desc->owner;
1046 
1047 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1048 
1049 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1050 	if (!ext_prop->name) {
1051 		kfree(vlabuf);
1052 		return ERR_PTR(-ENOMEM);
1053 	}
1054 	desc->ext_prop_len += 14;
1055 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1056 	if (desc->opts_mutex)
1057 		mutex_lock(desc->opts_mutex);
1058 	desc->ext_prop_len += ext_prop->name_len;
1059 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1060 	++desc->ext_prop_count;
1061 	if (desc->opts_mutex)
1062 		mutex_unlock(desc->opts_mutex);
1063 
1064 	return &ext_prop->item;
1065 }
1066 
1067 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1068 {
1069 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1070 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1071 
1072 	if (desc->opts_mutex)
1073 		mutex_lock(desc->opts_mutex);
1074 	list_del(&ext_prop->entry);
1075 	--desc->ext_prop_count;
1076 	kfree(ext_prop->name);
1077 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1078 	if (desc->opts_mutex)
1079 		mutex_unlock(desc->opts_mutex);
1080 	config_item_put(item);
1081 }
1082 
1083 static struct configfs_group_operations interf_grp_ops = {
1084 	.make_item	= &ext_prop_make,
1085 	.drop_item	= &ext_prop_drop,
1086 };
1087 
1088 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1089 					     char *page)
1090 {
1091 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1092 	return 8;
1093 }
1094 
1095 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1096 					      const char *page, size_t len)
1097 {
1098 	struct usb_os_desc *desc = to_usb_os_desc(item);
1099 	int l;
1100 
1101 	l = min_t(int, 8, len);
1102 	if (page[l - 1] == '\n')
1103 		--l;
1104 	if (desc->opts_mutex)
1105 		mutex_lock(desc->opts_mutex);
1106 	memcpy(desc->ext_compat_id, page, l);
1107 
1108 	if (desc->opts_mutex)
1109 		mutex_unlock(desc->opts_mutex);
1110 
1111 	return len;
1112 }
1113 
1114 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1115 						 char *page)
1116 {
1117 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1118 	return 8;
1119 }
1120 
1121 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1122 						  const char *page, size_t len)
1123 {
1124 	struct usb_os_desc *desc = to_usb_os_desc(item);
1125 	int l;
1126 
1127 	l = min_t(int, 8, len);
1128 	if (page[l - 1] == '\n')
1129 		--l;
1130 	if (desc->opts_mutex)
1131 		mutex_lock(desc->opts_mutex);
1132 	memcpy(desc->ext_compat_id + 8, page, l);
1133 
1134 	if (desc->opts_mutex)
1135 		mutex_unlock(desc->opts_mutex);
1136 
1137 	return len;
1138 }
1139 
1140 CONFIGFS_ATTR(interf_grp_, compatible_id);
1141 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1142 
1143 static struct configfs_attribute *interf_grp_attrs[] = {
1144 	&interf_grp_attr_compatible_id,
1145 	&interf_grp_attr_sub_compatible_id,
1146 	NULL
1147 };
1148 
1149 struct config_group *usb_os_desc_prepare_interf_dir(
1150 		struct config_group *parent,
1151 		int n_interf,
1152 		struct usb_os_desc **desc,
1153 		char **names,
1154 		struct module *owner)
1155 {
1156 	struct config_group *os_desc_group;
1157 	struct config_item_type *os_desc_type, *interface_type;
1158 
1159 	vla_group(data_chunk);
1160 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1161 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1162 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1163 
1164 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1165 	if (!vlabuf)
1166 		return ERR_PTR(-ENOMEM);
1167 
1168 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1169 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1170 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1171 
1172 	os_desc_type->ct_owner = owner;
1173 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1174 	configfs_add_default_group(os_desc_group, parent);
1175 
1176 	interface_type->ct_group_ops = &interf_grp_ops;
1177 	interface_type->ct_attrs = interf_grp_attrs;
1178 	interface_type->ct_owner = owner;
1179 
1180 	while (n_interf--) {
1181 		struct usb_os_desc *d;
1182 
1183 		d = desc[n_interf];
1184 		d->owner = owner;
1185 		config_group_init_type_name(&d->group, "", interface_type);
1186 		config_item_set_name(&d->group.cg_item, "interface.%s",
1187 				     names[n_interf]);
1188 		configfs_add_default_group(&d->group, os_desc_group);
1189 	}
1190 
1191 	return os_desc_group;
1192 }
1193 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1194 
1195 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1196 {
1197 	WARN_ON(1);
1198 	return -EINVAL;
1199 }
1200 
1201 int composite_dev_prepare(struct usb_composite_driver *composite,
1202 		struct usb_composite_dev *dev);
1203 
1204 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1205 				  struct usb_ep *ep0);
1206 
1207 static void purge_configs_funcs(struct gadget_info *gi)
1208 {
1209 	struct usb_configuration	*c;
1210 
1211 	list_for_each_entry(c, &gi->cdev.configs, list) {
1212 		struct usb_function *f, *tmp;
1213 		struct config_usb_cfg *cfg;
1214 
1215 		cfg = container_of(c, struct config_usb_cfg, c);
1216 
1217 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1218 
1219 			list_move_tail(&f->list, &cfg->func_list);
1220 			if (f->unbind) {
1221 				dev_dbg(&gi->cdev.gadget->dev,
1222 					"unbind function '%s'/%p\n",
1223 					f->name, f);
1224 				f->unbind(c, f);
1225 			}
1226 		}
1227 		c->next_interface_id = 0;
1228 		memset(c->interface, 0, sizeof(c->interface));
1229 		c->superspeed_plus = 0;
1230 		c->superspeed = 0;
1231 		c->highspeed = 0;
1232 		c->fullspeed = 0;
1233 	}
1234 }
1235 
1236 static int configfs_composite_bind(struct usb_gadget *gadget,
1237 		struct usb_gadget_driver *gdriver)
1238 {
1239 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1240 	struct gadget_info		*gi = container_of(composite,
1241 						struct gadget_info, composite);
1242 	struct usb_composite_dev	*cdev = &gi->cdev;
1243 	struct usb_configuration	*c;
1244 	struct usb_string		*s;
1245 	unsigned			i;
1246 	int				ret;
1247 
1248 	/* the gi->lock is hold by the caller */
1249 	gi->unbind = 0;
1250 	cdev->gadget = gadget;
1251 	set_gadget_data(gadget, cdev);
1252 	ret = composite_dev_prepare(composite, cdev);
1253 	if (ret)
1254 		return ret;
1255 	/* and now the gadget bind */
1256 	ret = -EINVAL;
1257 
1258 	if (list_empty(&gi->cdev.configs)) {
1259 		pr_err("Need at least one configuration in %s.\n",
1260 				gi->composite.name);
1261 		goto err_comp_cleanup;
1262 	}
1263 
1264 
1265 	list_for_each_entry(c, &gi->cdev.configs, list) {
1266 		struct config_usb_cfg *cfg;
1267 
1268 		cfg = container_of(c, struct config_usb_cfg, c);
1269 		if (list_empty(&cfg->func_list)) {
1270 			pr_err("Config %s/%d of %s needs at least one function.\n",
1271 			      c->label, c->bConfigurationValue,
1272 			      gi->composite.name);
1273 			goto err_comp_cleanup;
1274 		}
1275 	}
1276 
1277 	/* init all strings */
1278 	if (!list_empty(&gi->string_list)) {
1279 		struct gadget_strings *gs;
1280 
1281 		i = 0;
1282 		list_for_each_entry(gs, &gi->string_list, list) {
1283 
1284 			gi->gstrings[i] = &gs->stringtab_dev;
1285 			gs->stringtab_dev.strings = gs->strings;
1286 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1287 				gs->manufacturer;
1288 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1289 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1290 			i++;
1291 		}
1292 		gi->gstrings[i] = NULL;
1293 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1294 				USB_GADGET_FIRST_AVAIL_IDX);
1295 		if (IS_ERR(s)) {
1296 			ret = PTR_ERR(s);
1297 			goto err_comp_cleanup;
1298 		}
1299 
1300 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1301 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1302 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1303 	}
1304 
1305 	if (gi->use_os_desc) {
1306 		cdev->use_os_string = true;
1307 		cdev->b_vendor_code = gi->b_vendor_code;
1308 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1309 	}
1310 
1311 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1312 		struct usb_descriptor_header *usb_desc;
1313 
1314 		usb_desc = usb_otg_descriptor_alloc(gadget);
1315 		if (!usb_desc) {
1316 			ret = -ENOMEM;
1317 			goto err_comp_cleanup;
1318 		}
1319 		usb_otg_descriptor_init(gadget, usb_desc);
1320 		otg_desc[0] = usb_desc;
1321 		otg_desc[1] = NULL;
1322 	}
1323 
1324 	/* Go through all configs, attach all functions */
1325 	list_for_each_entry(c, &gi->cdev.configs, list) {
1326 		struct config_usb_cfg *cfg;
1327 		struct usb_function *f;
1328 		struct usb_function *tmp;
1329 		struct gadget_config_name *cn;
1330 
1331 		if (gadget_is_otg(gadget))
1332 			c->descriptors = otg_desc;
1333 
1334 		cfg = container_of(c, struct config_usb_cfg, c);
1335 		if (!list_empty(&cfg->string_list)) {
1336 			i = 0;
1337 			list_for_each_entry(cn, &cfg->string_list, list) {
1338 				cfg->gstrings[i] = &cn->stringtab_dev;
1339 				cn->stringtab_dev.strings = &cn->strings;
1340 				cn->strings.s = cn->configuration;
1341 				i++;
1342 			}
1343 			cfg->gstrings[i] = NULL;
1344 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1345 			if (IS_ERR(s)) {
1346 				ret = PTR_ERR(s);
1347 				goto err_comp_cleanup;
1348 			}
1349 			c->iConfiguration = s[0].id;
1350 		}
1351 
1352 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1353 			list_del(&f->list);
1354 			ret = usb_add_function(c, f);
1355 			if (ret) {
1356 				list_add(&f->list, &cfg->func_list);
1357 				goto err_purge_funcs;
1358 			}
1359 		}
1360 		usb_ep_autoconfig_reset(cdev->gadget);
1361 	}
1362 	if (cdev->use_os_string) {
1363 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1364 		if (ret)
1365 			goto err_purge_funcs;
1366 	}
1367 
1368 	usb_ep_autoconfig_reset(cdev->gadget);
1369 	return 0;
1370 
1371 err_purge_funcs:
1372 	purge_configs_funcs(gi);
1373 err_comp_cleanup:
1374 	composite_dev_cleanup(cdev);
1375 	return ret;
1376 }
1377 
1378 static void configfs_composite_unbind(struct usb_gadget *gadget)
1379 {
1380 	struct usb_composite_dev	*cdev;
1381 	struct gadget_info		*gi;
1382 	unsigned long flags;
1383 
1384 	/* the gi->lock is hold by the caller */
1385 
1386 	cdev = get_gadget_data(gadget);
1387 	gi = container_of(cdev, struct gadget_info, cdev);
1388 	spin_lock_irqsave(&gi->spinlock, flags);
1389 	gi->unbind = 1;
1390 	spin_unlock_irqrestore(&gi->spinlock, flags);
1391 
1392 	kfree(otg_desc[0]);
1393 	otg_desc[0] = NULL;
1394 	purge_configs_funcs(gi);
1395 	composite_dev_cleanup(cdev);
1396 	usb_ep_autoconfig_reset(cdev->gadget);
1397 	spin_lock_irqsave(&gi->spinlock, flags);
1398 	cdev->gadget = NULL;
1399 	set_gadget_data(gadget, NULL);
1400 	spin_unlock_irqrestore(&gi->spinlock, flags);
1401 }
1402 
1403 static int configfs_composite_setup(struct usb_gadget *gadget,
1404 		const struct usb_ctrlrequest *ctrl)
1405 {
1406 	struct usb_composite_dev *cdev;
1407 	struct gadget_info *gi;
1408 	unsigned long flags;
1409 	int ret;
1410 
1411 	cdev = get_gadget_data(gadget);
1412 	if (!cdev)
1413 		return 0;
1414 
1415 	gi = container_of(cdev, struct gadget_info, cdev);
1416 	spin_lock_irqsave(&gi->spinlock, flags);
1417 	cdev = get_gadget_data(gadget);
1418 	if (!cdev || gi->unbind) {
1419 		spin_unlock_irqrestore(&gi->spinlock, flags);
1420 		return 0;
1421 	}
1422 
1423 	ret = composite_setup(gadget, ctrl);
1424 	spin_unlock_irqrestore(&gi->spinlock, flags);
1425 	return ret;
1426 }
1427 
1428 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1429 {
1430 	struct usb_composite_dev *cdev;
1431 	struct gadget_info *gi;
1432 	unsigned long flags;
1433 
1434 	cdev = get_gadget_data(gadget);
1435 	if (!cdev)
1436 		return;
1437 
1438 	gi = container_of(cdev, struct gadget_info, cdev);
1439 	spin_lock_irqsave(&gi->spinlock, flags);
1440 	cdev = get_gadget_data(gadget);
1441 	if (!cdev || gi->unbind) {
1442 		spin_unlock_irqrestore(&gi->spinlock, flags);
1443 		return;
1444 	}
1445 
1446 	composite_disconnect(gadget);
1447 	spin_unlock_irqrestore(&gi->spinlock, flags);
1448 }
1449 
1450 static void configfs_composite_suspend(struct usb_gadget *gadget)
1451 {
1452 	struct usb_composite_dev *cdev;
1453 	struct gadget_info *gi;
1454 	unsigned long flags;
1455 
1456 	cdev = get_gadget_data(gadget);
1457 	if (!cdev)
1458 		return;
1459 
1460 	gi = container_of(cdev, struct gadget_info, cdev);
1461 	spin_lock_irqsave(&gi->spinlock, flags);
1462 	cdev = get_gadget_data(gadget);
1463 	if (!cdev || gi->unbind) {
1464 		spin_unlock_irqrestore(&gi->spinlock, flags);
1465 		return;
1466 	}
1467 
1468 	composite_suspend(gadget);
1469 	spin_unlock_irqrestore(&gi->spinlock, flags);
1470 }
1471 
1472 static void configfs_composite_resume(struct usb_gadget *gadget)
1473 {
1474 	struct usb_composite_dev *cdev;
1475 	struct gadget_info *gi;
1476 	unsigned long flags;
1477 
1478 	cdev = get_gadget_data(gadget);
1479 	if (!cdev)
1480 		return;
1481 
1482 	gi = container_of(cdev, struct gadget_info, cdev);
1483 	spin_lock_irqsave(&gi->spinlock, flags);
1484 	cdev = get_gadget_data(gadget);
1485 	if (!cdev || gi->unbind) {
1486 		spin_unlock_irqrestore(&gi->spinlock, flags);
1487 		return;
1488 	}
1489 
1490 	composite_resume(gadget);
1491 	spin_unlock_irqrestore(&gi->spinlock, flags);
1492 }
1493 
1494 static const struct usb_gadget_driver configfs_driver_template = {
1495 	.bind           = configfs_composite_bind,
1496 	.unbind         = configfs_composite_unbind,
1497 
1498 	.setup          = configfs_composite_setup,
1499 	.reset          = configfs_composite_disconnect,
1500 	.disconnect     = configfs_composite_disconnect,
1501 
1502 	.suspend	= configfs_composite_suspend,
1503 	.resume		= configfs_composite_resume,
1504 
1505 	.max_speed	= USB_SPEED_SUPER,
1506 	.driver = {
1507 		.owner          = THIS_MODULE,
1508 		.name		= "configfs-gadget",
1509 	},
1510 	.match_existing_only = 1,
1511 };
1512 
1513 static struct config_group *gadgets_make(
1514 		struct config_group *group,
1515 		const char *name)
1516 {
1517 	struct gadget_info *gi;
1518 
1519 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1520 	if (!gi)
1521 		return ERR_PTR(-ENOMEM);
1522 
1523 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1524 
1525 	config_group_init_type_name(&gi->functions_group, "functions",
1526 			&functions_type);
1527 	configfs_add_default_group(&gi->functions_group, &gi->group);
1528 
1529 	config_group_init_type_name(&gi->configs_group, "configs",
1530 			&config_desc_type);
1531 	configfs_add_default_group(&gi->configs_group, &gi->group);
1532 
1533 	config_group_init_type_name(&gi->strings_group, "strings",
1534 			&gadget_strings_strings_type);
1535 	configfs_add_default_group(&gi->strings_group, &gi->group);
1536 
1537 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1538 			&os_desc_type);
1539 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1540 
1541 	gi->composite.bind = configfs_do_nothing;
1542 	gi->composite.unbind = configfs_do_nothing;
1543 	gi->composite.suspend = NULL;
1544 	gi->composite.resume = NULL;
1545 	gi->composite.max_speed = USB_SPEED_SUPER;
1546 
1547 	mutex_init(&gi->lock);
1548 	INIT_LIST_HEAD(&gi->string_list);
1549 	INIT_LIST_HEAD(&gi->available_func);
1550 
1551 	composite_init_dev(&gi->cdev);
1552 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1553 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1554 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1555 
1556 	gi->composite.gadget_driver = configfs_driver_template;
1557 
1558 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1559 	gi->composite.name = gi->composite.gadget_driver.function;
1560 
1561 	if (!gi->composite.gadget_driver.function)
1562 		goto err;
1563 
1564 	return &gi->group;
1565 err:
1566 	kfree(gi);
1567 	return ERR_PTR(-ENOMEM);
1568 }
1569 
1570 static void gadgets_drop(struct config_group *group, struct config_item *item)
1571 {
1572 	config_item_put(item);
1573 }
1574 
1575 static struct configfs_group_operations gadgets_ops = {
1576 	.make_group     = &gadgets_make,
1577 	.drop_item      = &gadgets_drop,
1578 };
1579 
1580 static const struct config_item_type gadgets_type = {
1581 	.ct_group_ops   = &gadgets_ops,
1582 	.ct_owner       = THIS_MODULE,
1583 };
1584 
1585 static struct configfs_subsystem gadget_subsys = {
1586 	.su_group = {
1587 		.cg_item = {
1588 			.ci_namebuf = "usb_gadget",
1589 			.ci_type = &gadgets_type,
1590 		},
1591 	},
1592 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1593 };
1594 
1595 void unregister_gadget_item(struct config_item *item)
1596 {
1597 	struct gadget_info *gi = to_gadget_info(item);
1598 
1599 	mutex_lock(&gi->lock);
1600 	unregister_gadget(gi);
1601 	mutex_unlock(&gi->lock);
1602 }
1603 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1604 
1605 static int __init gadget_cfs_init(void)
1606 {
1607 	int ret;
1608 
1609 	config_group_init(&gadget_subsys.su_group);
1610 
1611 	ret = configfs_register_subsystem(&gadget_subsys);
1612 	return ret;
1613 }
1614 module_init(gadget_cfs_init);
1615 
1616 static void __exit gadget_cfs_exit(void)
1617 {
1618 	configfs_unregister_subsystem(&gadget_subsys);
1619 }
1620 module_exit(gadget_cfs_exit);
1621