xref: /openbmc/linux/drivers/usb/gadget/configfs.c (revision f20c7d91) 
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 	u16 num;
17 	int ret;
18 
19 	ret = kstrtou16(name, 0, &num);
20 	if (ret)
21 		return ret;
22 
23 	if (!usb_validate_langid(num))
24 		return -EINVAL;
25 
26 	stringtab_dev->language = num;
27 	return 0;
28 }
29 
30 #define MAX_NAME_LEN	40
31 #define MAX_USB_STRING_LANGS 2
32 
33 static const struct usb_descriptor_header *otg_desc[2];
34 
35 struct gadget_info {
36 	struct config_group group;
37 	struct config_group functions_group;
38 	struct config_group configs_group;
39 	struct config_group strings_group;
40 	struct config_group os_desc_group;
41 
42 	struct mutex lock;
43 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
44 	struct list_head string_list;
45 	struct list_head available_func;
46 
47 	struct usb_composite_driver composite;
48 	struct usb_composite_dev cdev;
49 	bool use_os_desc;
50 	char b_vendor_code;
51 	char qw_sign[OS_STRING_QW_SIGN_LEN];
52 	spinlock_t spinlock;
53 	bool unbind;
54 };
55 
56 static inline struct gadget_info *to_gadget_info(struct config_item *item)
57 {
58 	 return container_of(to_config_group(item), struct gadget_info, group);
59 }
60 
61 struct config_usb_cfg {
62 	struct config_group group;
63 	struct config_group strings_group;
64 	struct list_head string_list;
65 	struct usb_configuration c;
66 	struct list_head func_list;
67 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
68 };
69 
70 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
71 {
72 	return container_of(to_config_group(item), struct config_usb_cfg,
73 			group);
74 }
75 
76 struct gadget_strings {
77 	struct usb_gadget_strings stringtab_dev;
78 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
79 	char *manufacturer;
80 	char *product;
81 	char *serialnumber;
82 
83 	struct config_group group;
84 	struct list_head list;
85 };
86 
87 struct os_desc {
88 	struct config_group group;
89 };
90 
91 struct gadget_config_name {
92 	struct usb_gadget_strings stringtab_dev;
93 	struct usb_string strings;
94 	char *configuration;
95 
96 	struct config_group group;
97 	struct list_head list;
98 };
99 
100 static int usb_string_copy(const char *s, char **s_copy)
101 {
102 	int ret;
103 	char *str;
104 	char *copy = *s_copy;
105 	ret = strlen(s);
106 	if (ret > 126)
107 		return -EOVERFLOW;
108 
109 	str = kstrdup(s, GFP_KERNEL);
110 	if (!str)
111 		return -ENOMEM;
112 	if (str[ret - 1] == '\n')
113 		str[ret - 1] = '\0';
114 	kfree(copy);
115 	*s_copy = str;
116 	return 0;
117 }
118 
119 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
120 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
121 			char *page)	\
122 {	\
123 	return sprintf(page, "0x%02x\n", \
124 		to_gadget_info(item)->cdev.desc.__name); \
125 }
126 
127 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
128 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
129 			char *page)	\
130 {	\
131 	return sprintf(page, "0x%04x\n", \
132 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
133 }
134 
135 
136 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
137 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
138 		const char *page, size_t len)		\
139 {							\
140 	u8 val;						\
141 	int ret;					\
142 	ret = kstrtou8(page, 0, &val);			\
143 	if (ret)					\
144 		return ret;				\
145 	to_gadget_info(item)->cdev.desc._name = val;	\
146 	return len;					\
147 }
148 
149 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
150 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
151 		const char *page, size_t len)		\
152 {							\
153 	u16 val;					\
154 	int ret;					\
155 	ret = kstrtou16(page, 0, &val);			\
156 	if (ret)					\
157 		return ret;				\
158 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
159 	return len;					\
160 }
161 
162 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
163 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
164 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
165 
166 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
167 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
168 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
169 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
170 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
171 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
172 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
173 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
174 
175 static ssize_t is_valid_bcd(u16 bcd_val)
176 {
177 	if ((bcd_val & 0xf) > 9)
178 		return -EINVAL;
179 	if (((bcd_val >> 4) & 0xf) > 9)
180 		return -EINVAL;
181 	if (((bcd_val >> 8) & 0xf) > 9)
182 		return -EINVAL;
183 	if (((bcd_val >> 12) & 0xf) > 9)
184 		return -EINVAL;
185 	return 0;
186 }
187 
188 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
189 		const char *page, size_t len)
190 {
191 	u16 bcdDevice;
192 	int ret;
193 
194 	ret = kstrtou16(page, 0, &bcdDevice);
195 	if (ret)
196 		return ret;
197 	ret = is_valid_bcd(bcdDevice);
198 	if (ret)
199 		return ret;
200 
201 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
202 	return len;
203 }
204 
205 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
206 		const char *page, size_t len)
207 {
208 	u16 bcdUSB;
209 	int ret;
210 
211 	ret = kstrtou16(page, 0, &bcdUSB);
212 	if (ret)
213 		return ret;
214 	ret = is_valid_bcd(bcdUSB);
215 	if (ret)
216 		return ret;
217 
218 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
219 	return len;
220 }
221 
222 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
223 {
224 	char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;
225 
226 	return sprintf(page, "%s\n", udc_name ?: "");
227 }
228 
229 static int unregister_gadget(struct gadget_info *gi)
230 {
231 	int ret;
232 
233 	if (!gi->composite.gadget_driver.udc_name)
234 		return -ENODEV;
235 
236 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
237 	if (ret)
238 		return ret;
239 	kfree(gi->composite.gadget_driver.udc_name);
240 	gi->composite.gadget_driver.udc_name = NULL;
241 	return 0;
242 }
243 
244 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
245 		const char *page, size_t len)
246 {
247 	struct gadget_info *gi = to_gadget_info(item);
248 	char *name;
249 	int ret;
250 
251 	if (strlen(page) < len)
252 		return -EOVERFLOW;
253 
254 	name = kstrdup(page, GFP_KERNEL);
255 	if (!name)
256 		return -ENOMEM;
257 	if (name[len - 1] == '\n')
258 		name[len - 1] = '\0';
259 
260 	mutex_lock(&gi->lock);
261 
262 	if (!strlen(name)) {
263 		ret = unregister_gadget(gi);
264 		if (ret)
265 			goto err;
266 		kfree(name);
267 	} else {
268 		if (gi->composite.gadget_driver.udc_name) {
269 			ret = -EBUSY;
270 			goto err;
271 		}
272 		gi->composite.gadget_driver.udc_name = name;
273 		ret = usb_gadget_probe_driver(&gi->composite.gadget_driver);
274 		if (ret) {
275 			gi->composite.gadget_driver.udc_name = NULL;
276 			goto err;
277 		}
278 	}
279 	mutex_unlock(&gi->lock);
280 	return len;
281 err:
282 	kfree(name);
283 	mutex_unlock(&gi->lock);
284 	return ret;
285 }
286 
287 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
288 					      char *page)
289 {
290 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
291 
292 	return sprintf(page, "%s\n", usb_speed_string(speed));
293 }
294 
295 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
296 					       const char *page, size_t len)
297 {
298 	struct gadget_info *gi = to_gadget_info(item);
299 
300 	mutex_lock(&gi->lock);
301 
302 	/* Prevent changing of max_speed after the driver is binded */
303 	if (gi->composite.gadget_driver.udc_name)
304 		goto err;
305 
306 	if (strncmp(page, "super-speed-plus", 16) == 0)
307 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
308 	else if (strncmp(page, "super-speed", 11) == 0)
309 		gi->composite.max_speed = USB_SPEED_SUPER;
310 	else if (strncmp(page, "high-speed", 10) == 0)
311 		gi->composite.max_speed = USB_SPEED_HIGH;
312 	else if (strncmp(page, "full-speed", 10) == 0)
313 		gi->composite.max_speed = USB_SPEED_FULL;
314 	else if (strncmp(page, "low-speed", 9) == 0)
315 		gi->composite.max_speed = USB_SPEED_LOW;
316 	else
317 		goto err;
318 
319 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
320 
321 	mutex_unlock(&gi->lock);
322 	return len;
323 err:
324 	mutex_unlock(&gi->lock);
325 	return -EINVAL;
326 }
327 
328 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
329 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
330 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
331 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
332 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
333 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
334 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
335 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
336 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
337 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
338 
339 static struct configfs_attribute *gadget_root_attrs[] = {
340 	&gadget_dev_desc_attr_bDeviceClass,
341 	&gadget_dev_desc_attr_bDeviceSubClass,
342 	&gadget_dev_desc_attr_bDeviceProtocol,
343 	&gadget_dev_desc_attr_bMaxPacketSize0,
344 	&gadget_dev_desc_attr_idVendor,
345 	&gadget_dev_desc_attr_idProduct,
346 	&gadget_dev_desc_attr_bcdDevice,
347 	&gadget_dev_desc_attr_bcdUSB,
348 	&gadget_dev_desc_attr_UDC,
349 	&gadget_dev_desc_attr_max_speed,
350 	NULL,
351 };
352 
353 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
354 {
355 	 return container_of(to_config_group(item), struct gadget_strings,
356 			 group);
357 }
358 
359 static inline struct gadget_config_name *to_gadget_config_name(
360 		struct config_item *item)
361 {
362 	 return container_of(to_config_group(item), struct gadget_config_name,
363 			 group);
364 }
365 
366 static inline struct usb_function_instance *to_usb_function_instance(
367 		struct config_item *item)
368 {
369 	 return container_of(to_config_group(item),
370 			 struct usb_function_instance, group);
371 }
372 
373 static void gadget_info_attr_release(struct config_item *item)
374 {
375 	struct gadget_info *gi = to_gadget_info(item);
376 
377 	WARN_ON(!list_empty(&gi->cdev.configs));
378 	WARN_ON(!list_empty(&gi->string_list));
379 	WARN_ON(!list_empty(&gi->available_func));
380 	kfree(gi->composite.gadget_driver.function);
381 	kfree(gi);
382 }
383 
384 static struct configfs_item_operations gadget_root_item_ops = {
385 	.release                = gadget_info_attr_release,
386 };
387 
388 static void gadget_config_attr_release(struct config_item *item)
389 {
390 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
391 
392 	WARN_ON(!list_empty(&cfg->c.functions));
393 	list_del(&cfg->c.list);
394 	kfree(cfg->c.label);
395 	kfree(cfg);
396 }
397 
398 static int config_usb_cfg_link(
399 	struct config_item *usb_cfg_ci,
400 	struct config_item *usb_func_ci)
401 {
402 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
403 	struct usb_composite_dev *cdev = cfg->c.cdev;
404 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
405 
406 	struct config_group *group = to_config_group(usb_func_ci);
407 	struct usb_function_instance *fi = container_of(group,
408 			struct usb_function_instance, group);
409 	struct usb_function_instance *a_fi;
410 	struct usb_function *f;
411 	int ret;
412 
413 	mutex_lock(&gi->lock);
414 	/*
415 	 * Make sure this function is from within our _this_ gadget and not
416 	 * from another gadget or a random directory.
417 	 * Also a function instance can only be linked once.
418 	 */
419 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
420 		if (a_fi == fi)
421 			break;
422 	}
423 	if (a_fi != fi) {
424 		ret = -EINVAL;
425 		goto out;
426 	}
427 
428 	list_for_each_entry(f, &cfg->func_list, list) {
429 		if (f->fi == fi) {
430 			ret = -EEXIST;
431 			goto out;
432 		}
433 	}
434 
435 	f = usb_get_function(fi);
436 	if (IS_ERR(f)) {
437 		ret = PTR_ERR(f);
438 		goto out;
439 	}
440 
441 	/* stash the function until we bind it to the gadget */
442 	list_add_tail(&f->list, &cfg->func_list);
443 	ret = 0;
444 out:
445 	mutex_unlock(&gi->lock);
446 	return ret;
447 }
448 
449 static void config_usb_cfg_unlink(
450 	struct config_item *usb_cfg_ci,
451 	struct config_item *usb_func_ci)
452 {
453 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
454 	struct usb_composite_dev *cdev = cfg->c.cdev;
455 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
456 
457 	struct config_group *group = to_config_group(usb_func_ci);
458 	struct usb_function_instance *fi = container_of(group,
459 			struct usb_function_instance, group);
460 	struct usb_function *f;
461 
462 	/*
463 	 * ideally I would like to forbid to unlink functions while a gadget is
464 	 * bound to an UDC. Since this isn't possible at the moment, we simply
465 	 * force an unbind, the function is available here and then we can
466 	 * remove the function.
467 	 */
468 	mutex_lock(&gi->lock);
469 	if (gi->composite.gadget_driver.udc_name)
470 		unregister_gadget(gi);
471 	WARN_ON(gi->composite.gadget_driver.udc_name);
472 
473 	list_for_each_entry(f, &cfg->func_list, list) {
474 		if (f->fi == fi) {
475 			list_del(&f->list);
476 			usb_put_function(f);
477 			mutex_unlock(&gi->lock);
478 			return;
479 		}
480 	}
481 	mutex_unlock(&gi->lock);
482 	WARN(1, "Unable to locate function to unbind\n");
483 }
484 
485 static struct configfs_item_operations gadget_config_item_ops = {
486 	.release                = gadget_config_attr_release,
487 	.allow_link             = config_usb_cfg_link,
488 	.drop_link              = config_usb_cfg_unlink,
489 };
490 
491 
492 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
493 		char *page)
494 {
495 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
496 }
497 
498 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
499 		const char *page, size_t len)
500 {
501 	u16 val;
502 	int ret;
503 	ret = kstrtou16(page, 0, &val);
504 	if (ret)
505 		return ret;
506 	if (DIV_ROUND_UP(val, 8) > 0xff)
507 		return -ERANGE;
508 	to_config_usb_cfg(item)->c.MaxPower = val;
509 	return len;
510 }
511 
512 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
513 		char *page)
514 {
515 	return sprintf(page, "0x%02x\n",
516 		to_config_usb_cfg(item)->c.bmAttributes);
517 }
518 
519 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
520 		const char *page, size_t len)
521 {
522 	u8 val;
523 	int ret;
524 	ret = kstrtou8(page, 0, &val);
525 	if (ret)
526 		return ret;
527 	if (!(val & USB_CONFIG_ATT_ONE))
528 		return -EINVAL;
529 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
530 				USB_CONFIG_ATT_WAKEUP))
531 		return -EINVAL;
532 	to_config_usb_cfg(item)->c.bmAttributes = val;
533 	return len;
534 }
535 
536 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
537 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
538 
539 static struct configfs_attribute *gadget_config_attrs[] = {
540 	&gadget_config_desc_attr_MaxPower,
541 	&gadget_config_desc_attr_bmAttributes,
542 	NULL,
543 };
544 
545 static const struct config_item_type gadget_config_type = {
546 	.ct_item_ops	= &gadget_config_item_ops,
547 	.ct_attrs	= gadget_config_attrs,
548 	.ct_owner	= THIS_MODULE,
549 };
550 
551 static const struct config_item_type gadget_root_type = {
552 	.ct_item_ops	= &gadget_root_item_ops,
553 	.ct_attrs	= gadget_root_attrs,
554 	.ct_owner	= THIS_MODULE,
555 };
556 
557 static void composite_init_dev(struct usb_composite_dev *cdev)
558 {
559 	spin_lock_init(&cdev->lock);
560 	INIT_LIST_HEAD(&cdev->configs);
561 	INIT_LIST_HEAD(&cdev->gstrings);
562 }
563 
564 static struct config_group *function_make(
565 		struct config_group *group,
566 		const char *name)
567 {
568 	struct gadget_info *gi;
569 	struct usb_function_instance *fi;
570 	char buf[MAX_NAME_LEN];
571 	char *func_name;
572 	char *instance_name;
573 	int ret;
574 
575 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
576 	if (ret >= MAX_NAME_LEN)
577 		return ERR_PTR(-ENAMETOOLONG);
578 
579 	func_name = buf;
580 	instance_name = strchr(func_name, '.');
581 	if (!instance_name) {
582 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
583 		return ERR_PTR(-EINVAL);
584 	}
585 	*instance_name = '\0';
586 	instance_name++;
587 
588 	fi = usb_get_function_instance(func_name);
589 	if (IS_ERR(fi))
590 		return ERR_CAST(fi);
591 
592 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
593 	if (ret) {
594 		usb_put_function_instance(fi);
595 		return ERR_PTR(ret);
596 	}
597 	if (fi->set_inst_name) {
598 		ret = fi->set_inst_name(fi, instance_name);
599 		if (ret) {
600 			usb_put_function_instance(fi);
601 			return ERR_PTR(ret);
602 		}
603 	}
604 
605 	gi = container_of(group, struct gadget_info, functions_group);
606 
607 	mutex_lock(&gi->lock);
608 	list_add_tail(&fi->cfs_list, &gi->available_func);
609 	mutex_unlock(&gi->lock);
610 	return &fi->group;
611 }
612 
613 static void function_drop(
614 		struct config_group *group,
615 		struct config_item *item)
616 {
617 	struct usb_function_instance *fi = to_usb_function_instance(item);
618 	struct gadget_info *gi;
619 
620 	gi = container_of(group, struct gadget_info, functions_group);
621 
622 	mutex_lock(&gi->lock);
623 	list_del(&fi->cfs_list);
624 	mutex_unlock(&gi->lock);
625 	config_item_put(item);
626 }
627 
628 static struct configfs_group_operations functions_ops = {
629 	.make_group     = &function_make,
630 	.drop_item      = &function_drop,
631 };
632 
633 static const struct config_item_type functions_type = {
634 	.ct_group_ops   = &functions_ops,
635 	.ct_owner       = THIS_MODULE,
636 };
637 
638 GS_STRINGS_RW(gadget_config_name, configuration);
639 
640 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
641 	&gadget_config_name_attr_configuration,
642 	NULL,
643 };
644 
645 static void gadget_config_name_attr_release(struct config_item *item)
646 {
647 	struct gadget_config_name *cn = to_gadget_config_name(item);
648 
649 	kfree(cn->configuration);
650 
651 	list_del(&cn->list);
652 	kfree(cn);
653 }
654 
655 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
656 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
657 
658 static struct config_group *config_desc_make(
659 		struct config_group *group,
660 		const char *name)
661 {
662 	struct gadget_info *gi;
663 	struct config_usb_cfg *cfg;
664 	char buf[MAX_NAME_LEN];
665 	char *num_str;
666 	u8 num;
667 	int ret;
668 
669 	gi = container_of(group, struct gadget_info, configs_group);
670 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
671 	if (ret >= MAX_NAME_LEN)
672 		return ERR_PTR(-ENAMETOOLONG);
673 
674 	num_str = strchr(buf, '.');
675 	if (!num_str) {
676 		pr_err("Unable to locate . in name.bConfigurationValue\n");
677 		return ERR_PTR(-EINVAL);
678 	}
679 
680 	*num_str = '\0';
681 	num_str++;
682 
683 	if (!strlen(buf))
684 		return ERR_PTR(-EINVAL);
685 
686 	ret = kstrtou8(num_str, 0, &num);
687 	if (ret)
688 		return ERR_PTR(ret);
689 
690 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
691 	if (!cfg)
692 		return ERR_PTR(-ENOMEM);
693 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
694 	if (!cfg->c.label) {
695 		ret = -ENOMEM;
696 		goto err;
697 	}
698 	cfg->c.bConfigurationValue = num;
699 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
700 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
701 	INIT_LIST_HEAD(&cfg->string_list);
702 	INIT_LIST_HEAD(&cfg->func_list);
703 
704 	config_group_init_type_name(&cfg->group, name,
705 				&gadget_config_type);
706 
707 	config_group_init_type_name(&cfg->strings_group, "strings",
708 			&gadget_config_name_strings_type);
709 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
710 
711 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
712 	if (ret)
713 		goto err;
714 
715 	return &cfg->group;
716 err:
717 	kfree(cfg->c.label);
718 	kfree(cfg);
719 	return ERR_PTR(ret);
720 }
721 
722 static void config_desc_drop(
723 		struct config_group *group,
724 		struct config_item *item)
725 {
726 	config_item_put(item);
727 }
728 
729 static struct configfs_group_operations config_desc_ops = {
730 	.make_group     = &config_desc_make,
731 	.drop_item      = &config_desc_drop,
732 };
733 
734 static const struct config_item_type config_desc_type = {
735 	.ct_group_ops   = &config_desc_ops,
736 	.ct_owner       = THIS_MODULE,
737 };
738 
739 GS_STRINGS_RW(gadget_strings, manufacturer);
740 GS_STRINGS_RW(gadget_strings, product);
741 GS_STRINGS_RW(gadget_strings, serialnumber);
742 
743 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
744 	&gadget_strings_attr_manufacturer,
745 	&gadget_strings_attr_product,
746 	&gadget_strings_attr_serialnumber,
747 	NULL,
748 };
749 
750 static void gadget_strings_attr_release(struct config_item *item)
751 {
752 	struct gadget_strings *gs = to_gadget_strings(item);
753 
754 	kfree(gs->manufacturer);
755 	kfree(gs->product);
756 	kfree(gs->serialnumber);
757 
758 	list_del(&gs->list);
759 	kfree(gs);
760 }
761 
762 USB_CONFIG_STRING_RW_OPS(gadget_strings);
763 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
764 
765 static inline struct os_desc *to_os_desc(struct config_item *item)
766 {
767 	return container_of(to_config_group(item), struct os_desc, group);
768 }
769 
770 static inline struct gadget_info *os_desc_item_to_gadget_info(
771 		struct config_item *item)
772 {
773 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
774 }
775 
776 static ssize_t os_desc_use_show(struct config_item *item, char *page)
777 {
778 	return sprintf(page, "%d\n",
779 			os_desc_item_to_gadget_info(item)->use_os_desc);
780 }
781 
782 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
783 				 size_t len)
784 {
785 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
786 	int ret;
787 	bool use;
788 
789 	mutex_lock(&gi->lock);
790 	ret = strtobool(page, &use);
791 	if (!ret) {
792 		gi->use_os_desc = use;
793 		ret = len;
794 	}
795 	mutex_unlock(&gi->lock);
796 
797 	return ret;
798 }
799 
800 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
801 {
802 	return sprintf(page, "0x%02x\n",
803 			os_desc_item_to_gadget_info(item)->b_vendor_code);
804 }
805 
806 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
807 					   const char *page, size_t len)
808 {
809 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
810 	int ret;
811 	u8 b_vendor_code;
812 
813 	mutex_lock(&gi->lock);
814 	ret = kstrtou8(page, 0, &b_vendor_code);
815 	if (!ret) {
816 		gi->b_vendor_code = b_vendor_code;
817 		ret = len;
818 	}
819 	mutex_unlock(&gi->lock);
820 
821 	return ret;
822 }
823 
824 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
825 {
826 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
827 	int res;
828 
829 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
830 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
831 	page[res++] = '\n';
832 
833 	return res;
834 }
835 
836 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
837 				     size_t len)
838 {
839 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
840 	int res, l;
841 
842 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
843 	if (page[l - 1] == '\n')
844 		--l;
845 
846 	mutex_lock(&gi->lock);
847 	res = utf8s_to_utf16s(page, l,
848 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
849 			      OS_STRING_QW_SIGN_LEN);
850 	if (res > 0)
851 		res = len;
852 	mutex_unlock(&gi->lock);
853 
854 	return res;
855 }
856 
857 CONFIGFS_ATTR(os_desc_, use);
858 CONFIGFS_ATTR(os_desc_, b_vendor_code);
859 CONFIGFS_ATTR(os_desc_, qw_sign);
860 
861 static struct configfs_attribute *os_desc_attrs[] = {
862 	&os_desc_attr_use,
863 	&os_desc_attr_b_vendor_code,
864 	&os_desc_attr_qw_sign,
865 	NULL,
866 };
867 
868 static void os_desc_attr_release(struct config_item *item)
869 {
870 	struct os_desc *os_desc = to_os_desc(item);
871 	kfree(os_desc);
872 }
873 
874 static int os_desc_link(struct config_item *os_desc_ci,
875 			struct config_item *usb_cfg_ci)
876 {
877 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
878 					struct gadget_info, os_desc_group);
879 	struct usb_composite_dev *cdev = &gi->cdev;
880 	struct config_usb_cfg *c_target =
881 		container_of(to_config_group(usb_cfg_ci),
882 			     struct config_usb_cfg, group);
883 	struct usb_configuration *c;
884 	int ret;
885 
886 	mutex_lock(&gi->lock);
887 	list_for_each_entry(c, &cdev->configs, list) {
888 		if (c == &c_target->c)
889 			break;
890 	}
891 	if (c != &c_target->c) {
892 		ret = -EINVAL;
893 		goto out;
894 	}
895 
896 	if (cdev->os_desc_config) {
897 		ret = -EBUSY;
898 		goto out;
899 	}
900 
901 	cdev->os_desc_config = &c_target->c;
902 	ret = 0;
903 
904 out:
905 	mutex_unlock(&gi->lock);
906 	return ret;
907 }
908 
909 static void os_desc_unlink(struct config_item *os_desc_ci,
910 			  struct config_item *usb_cfg_ci)
911 {
912 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
913 					struct gadget_info, os_desc_group);
914 	struct usb_composite_dev *cdev = &gi->cdev;
915 
916 	mutex_lock(&gi->lock);
917 	if (gi->composite.gadget_driver.udc_name)
918 		unregister_gadget(gi);
919 	cdev->os_desc_config = NULL;
920 	WARN_ON(gi->composite.gadget_driver.udc_name);
921 	mutex_unlock(&gi->lock);
922 }
923 
924 static struct configfs_item_operations os_desc_ops = {
925 	.release                = os_desc_attr_release,
926 	.allow_link		= os_desc_link,
927 	.drop_link		= os_desc_unlink,
928 };
929 
930 static struct config_item_type os_desc_type = {
931 	.ct_item_ops	= &os_desc_ops,
932 	.ct_attrs	= os_desc_attrs,
933 	.ct_owner	= THIS_MODULE,
934 };
935 
936 static inline struct usb_os_desc_ext_prop
937 *to_usb_os_desc_ext_prop(struct config_item *item)
938 {
939 	return container_of(item, struct usb_os_desc_ext_prop, item);
940 }
941 
942 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
943 {
944 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
945 }
946 
947 static ssize_t ext_prop_type_store(struct config_item *item,
948 				   const char *page, size_t len)
949 {
950 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
951 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
952 	u8 type;
953 	int ret;
954 
955 	if (desc->opts_mutex)
956 		mutex_lock(desc->opts_mutex);
957 	ret = kstrtou8(page, 0, &type);
958 	if (ret)
959 		goto end;
960 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
961 		ret = -EINVAL;
962 		goto end;
963 	}
964 
965 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
966 	    ext_prop->type == USB_EXT_PROP_LE32 ||
967 	    ext_prop->type == USB_EXT_PROP_BE32) &&
968 	    (type == USB_EXT_PROP_UNICODE ||
969 	    type == USB_EXT_PROP_UNICODE_ENV ||
970 	    type == USB_EXT_PROP_UNICODE_LINK))
971 		ext_prop->data_len <<= 1;
972 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
973 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
974 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
975 		   (type == USB_EXT_PROP_BINARY ||
976 		   type == USB_EXT_PROP_LE32 ||
977 		   type == USB_EXT_PROP_BE32))
978 		ext_prop->data_len >>= 1;
979 	ext_prop->type = type;
980 	ret = len;
981 
982 end:
983 	if (desc->opts_mutex)
984 		mutex_unlock(desc->opts_mutex);
985 	return ret;
986 }
987 
988 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
989 {
990 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
991 	int len = ext_prop->data_len;
992 
993 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
994 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
995 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
996 		len >>= 1;
997 	memcpy(page, ext_prop->data, len);
998 
999 	return len;
1000 }
1001 
1002 static ssize_t ext_prop_data_store(struct config_item *item,
1003 				   const char *page, size_t len)
1004 {
1005 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1006 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1007 	char *new_data;
1008 	size_t ret_len = len;
1009 
1010 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1011 		--len;
1012 	new_data = kmemdup(page, len, GFP_KERNEL);
1013 	if (!new_data)
1014 		return -ENOMEM;
1015 
1016 	if (desc->opts_mutex)
1017 		mutex_lock(desc->opts_mutex);
1018 	kfree(ext_prop->data);
1019 	ext_prop->data = new_data;
1020 	desc->ext_prop_len -= ext_prop->data_len;
1021 	ext_prop->data_len = len;
1022 	desc->ext_prop_len += ext_prop->data_len;
1023 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1024 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1025 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1026 		desc->ext_prop_len -= ext_prop->data_len;
1027 		ext_prop->data_len <<= 1;
1028 		ext_prop->data_len += 2;
1029 		desc->ext_prop_len += ext_prop->data_len;
1030 	}
1031 	if (desc->opts_mutex)
1032 		mutex_unlock(desc->opts_mutex);
1033 	return ret_len;
1034 }
1035 
1036 CONFIGFS_ATTR(ext_prop_, type);
1037 CONFIGFS_ATTR(ext_prop_, data);
1038 
1039 static struct configfs_attribute *ext_prop_attrs[] = {
1040 	&ext_prop_attr_type,
1041 	&ext_prop_attr_data,
1042 	NULL,
1043 };
1044 
1045 static void usb_os_desc_ext_prop_release(struct config_item *item)
1046 {
1047 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1048 
1049 	kfree(ext_prop); /* frees a whole chunk */
1050 }
1051 
1052 static struct configfs_item_operations ext_prop_ops = {
1053 	.release		= usb_os_desc_ext_prop_release,
1054 };
1055 
1056 static struct config_item *ext_prop_make(
1057 		struct config_group *group,
1058 		const char *name)
1059 {
1060 	struct usb_os_desc_ext_prop *ext_prop;
1061 	struct config_item_type *ext_prop_type;
1062 	struct usb_os_desc *desc;
1063 	char *vlabuf;
1064 
1065 	vla_group(data_chunk);
1066 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1067 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1068 
1069 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1070 	if (!vlabuf)
1071 		return ERR_PTR(-ENOMEM);
1072 
1073 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1074 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1075 
1076 	desc = container_of(group, struct usb_os_desc, group);
1077 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1078 	ext_prop_type->ct_attrs = ext_prop_attrs;
1079 	ext_prop_type->ct_owner = desc->owner;
1080 
1081 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1082 
1083 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1084 	if (!ext_prop->name) {
1085 		kfree(vlabuf);
1086 		return ERR_PTR(-ENOMEM);
1087 	}
1088 	desc->ext_prop_len += 14;
1089 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1090 	if (desc->opts_mutex)
1091 		mutex_lock(desc->opts_mutex);
1092 	desc->ext_prop_len += ext_prop->name_len;
1093 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1094 	++desc->ext_prop_count;
1095 	if (desc->opts_mutex)
1096 		mutex_unlock(desc->opts_mutex);
1097 
1098 	return &ext_prop->item;
1099 }
1100 
1101 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1102 {
1103 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1104 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1105 
1106 	if (desc->opts_mutex)
1107 		mutex_lock(desc->opts_mutex);
1108 	list_del(&ext_prop->entry);
1109 	--desc->ext_prop_count;
1110 	kfree(ext_prop->name);
1111 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1112 	if (desc->opts_mutex)
1113 		mutex_unlock(desc->opts_mutex);
1114 	config_item_put(item);
1115 }
1116 
1117 static struct configfs_group_operations interf_grp_ops = {
1118 	.make_item	= &ext_prop_make,
1119 	.drop_item	= &ext_prop_drop,
1120 };
1121 
1122 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1123 					     char *page)
1124 {
1125 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1126 	return 8;
1127 }
1128 
1129 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1130 					      const char *page, size_t len)
1131 {
1132 	struct usb_os_desc *desc = to_usb_os_desc(item);
1133 	int l;
1134 
1135 	l = min_t(int, 8, len);
1136 	if (page[l - 1] == '\n')
1137 		--l;
1138 	if (desc->opts_mutex)
1139 		mutex_lock(desc->opts_mutex);
1140 	memcpy(desc->ext_compat_id, page, l);
1141 
1142 	if (desc->opts_mutex)
1143 		mutex_unlock(desc->opts_mutex);
1144 
1145 	return len;
1146 }
1147 
1148 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1149 						 char *page)
1150 {
1151 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1152 	return 8;
1153 }
1154 
1155 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1156 						  const char *page, size_t len)
1157 {
1158 	struct usb_os_desc *desc = to_usb_os_desc(item);
1159 	int l;
1160 
1161 	l = min_t(int, 8, len);
1162 	if (page[l - 1] == '\n')
1163 		--l;
1164 	if (desc->opts_mutex)
1165 		mutex_lock(desc->opts_mutex);
1166 	memcpy(desc->ext_compat_id + 8, page, l);
1167 
1168 	if (desc->opts_mutex)
1169 		mutex_unlock(desc->opts_mutex);
1170 
1171 	return len;
1172 }
1173 
1174 CONFIGFS_ATTR(interf_grp_, compatible_id);
1175 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1176 
1177 static struct configfs_attribute *interf_grp_attrs[] = {
1178 	&interf_grp_attr_compatible_id,
1179 	&interf_grp_attr_sub_compatible_id,
1180 	NULL
1181 };
1182 
1183 struct config_group *usb_os_desc_prepare_interf_dir(
1184 		struct config_group *parent,
1185 		int n_interf,
1186 		struct usb_os_desc **desc,
1187 		char **names,
1188 		struct module *owner)
1189 {
1190 	struct config_group *os_desc_group;
1191 	struct config_item_type *os_desc_type, *interface_type;
1192 
1193 	vla_group(data_chunk);
1194 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1195 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1196 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1197 
1198 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1199 	if (!vlabuf)
1200 		return ERR_PTR(-ENOMEM);
1201 
1202 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1203 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1204 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1205 
1206 	os_desc_type->ct_owner = owner;
1207 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1208 	configfs_add_default_group(os_desc_group, parent);
1209 
1210 	interface_type->ct_group_ops = &interf_grp_ops;
1211 	interface_type->ct_attrs = interf_grp_attrs;
1212 	interface_type->ct_owner = owner;
1213 
1214 	while (n_interf--) {
1215 		struct usb_os_desc *d;
1216 
1217 		d = desc[n_interf];
1218 		d->owner = owner;
1219 		config_group_init_type_name(&d->group, "", interface_type);
1220 		config_item_set_name(&d->group.cg_item, "interface.%s",
1221 				     names[n_interf]);
1222 		configfs_add_default_group(&d->group, os_desc_group);
1223 	}
1224 
1225 	return os_desc_group;
1226 }
1227 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1228 
1229 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1230 {
1231 	WARN_ON(1);
1232 	return -EINVAL;
1233 }
1234 
1235 int composite_dev_prepare(struct usb_composite_driver *composite,
1236 		struct usb_composite_dev *dev);
1237 
1238 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1239 				  struct usb_ep *ep0);
1240 
1241 static void purge_configs_funcs(struct gadget_info *gi)
1242 {
1243 	struct usb_configuration	*c;
1244 
1245 	list_for_each_entry(c, &gi->cdev.configs, list) {
1246 		struct usb_function *f, *tmp;
1247 		struct config_usb_cfg *cfg;
1248 
1249 		cfg = container_of(c, struct config_usb_cfg, c);
1250 
1251 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1252 
1253 			list_move_tail(&f->list, &cfg->func_list);
1254 			if (f->unbind) {
1255 				dev_dbg(&gi->cdev.gadget->dev,
1256 					"unbind function '%s'/%p\n",
1257 					f->name, f);
1258 				f->unbind(c, f);
1259 			}
1260 		}
1261 		c->next_interface_id = 0;
1262 		memset(c->interface, 0, sizeof(c->interface));
1263 		c->superspeed_plus = 0;
1264 		c->superspeed = 0;
1265 		c->highspeed = 0;
1266 		c->fullspeed = 0;
1267 	}
1268 }
1269 
1270 static int configfs_composite_bind(struct usb_gadget *gadget,
1271 		struct usb_gadget_driver *gdriver)
1272 {
1273 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1274 	struct gadget_info		*gi = container_of(composite,
1275 						struct gadget_info, composite);
1276 	struct usb_composite_dev	*cdev = &gi->cdev;
1277 	struct usb_configuration	*c;
1278 	struct usb_string		*s;
1279 	unsigned			i;
1280 	int				ret;
1281 
1282 	/* the gi->lock is hold by the caller */
1283 	gi->unbind = 0;
1284 	cdev->gadget = gadget;
1285 	set_gadget_data(gadget, cdev);
1286 	ret = composite_dev_prepare(composite, cdev);
1287 	if (ret)
1288 		return ret;
1289 	/* and now the gadget bind */
1290 	ret = -EINVAL;
1291 
1292 	if (list_empty(&gi->cdev.configs)) {
1293 		pr_err("Need at least one configuration in %s.\n",
1294 				gi->composite.name);
1295 		goto err_comp_cleanup;
1296 	}
1297 
1298 
1299 	list_for_each_entry(c, &gi->cdev.configs, list) {
1300 		struct config_usb_cfg *cfg;
1301 
1302 		cfg = container_of(c, struct config_usb_cfg, c);
1303 		if (list_empty(&cfg->func_list)) {
1304 			pr_err("Config %s/%d of %s needs at least one function.\n",
1305 			      c->label, c->bConfigurationValue,
1306 			      gi->composite.name);
1307 			goto err_comp_cleanup;
1308 		}
1309 	}
1310 
1311 	/* init all strings */
1312 	if (!list_empty(&gi->string_list)) {
1313 		struct gadget_strings *gs;
1314 
1315 		i = 0;
1316 		list_for_each_entry(gs, &gi->string_list, list) {
1317 
1318 			gi->gstrings[i] = &gs->stringtab_dev;
1319 			gs->stringtab_dev.strings = gs->strings;
1320 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1321 				gs->manufacturer;
1322 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1323 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1324 			i++;
1325 		}
1326 		gi->gstrings[i] = NULL;
1327 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1328 				USB_GADGET_FIRST_AVAIL_IDX);
1329 		if (IS_ERR(s)) {
1330 			ret = PTR_ERR(s);
1331 			goto err_comp_cleanup;
1332 		}
1333 
1334 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1335 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1336 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1337 	}
1338 
1339 	if (gi->use_os_desc) {
1340 		cdev->use_os_string = true;
1341 		cdev->b_vendor_code = gi->b_vendor_code;
1342 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1343 	}
1344 
1345 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1346 		struct usb_descriptor_header *usb_desc;
1347 
1348 		usb_desc = usb_otg_descriptor_alloc(gadget);
1349 		if (!usb_desc) {
1350 			ret = -ENOMEM;
1351 			goto err_comp_cleanup;
1352 		}
1353 		usb_otg_descriptor_init(gadget, usb_desc);
1354 		otg_desc[0] = usb_desc;
1355 		otg_desc[1] = NULL;
1356 	}
1357 
1358 	/* Go through all configs, attach all functions */
1359 	list_for_each_entry(c, &gi->cdev.configs, list) {
1360 		struct config_usb_cfg *cfg;
1361 		struct usb_function *f;
1362 		struct usb_function *tmp;
1363 		struct gadget_config_name *cn;
1364 
1365 		if (gadget_is_otg(gadget))
1366 			c->descriptors = otg_desc;
1367 
1368 		cfg = container_of(c, struct config_usb_cfg, c);
1369 		if (!list_empty(&cfg->string_list)) {
1370 			i = 0;
1371 			list_for_each_entry(cn, &cfg->string_list, list) {
1372 				cfg->gstrings[i] = &cn->stringtab_dev;
1373 				cn->stringtab_dev.strings = &cn->strings;
1374 				cn->strings.s = cn->configuration;
1375 				i++;
1376 			}
1377 			cfg->gstrings[i] = NULL;
1378 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1379 			if (IS_ERR(s)) {
1380 				ret = PTR_ERR(s);
1381 				goto err_comp_cleanup;
1382 			}
1383 			c->iConfiguration = s[0].id;
1384 		}
1385 
1386 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1387 			list_del(&f->list);
1388 			ret = usb_add_function(c, f);
1389 			if (ret) {
1390 				list_add(&f->list, &cfg->func_list);
1391 				goto err_purge_funcs;
1392 			}
1393 		}
1394 		usb_ep_autoconfig_reset(cdev->gadget);
1395 	}
1396 	if (cdev->use_os_string) {
1397 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1398 		if (ret)
1399 			goto err_purge_funcs;
1400 	}
1401 
1402 	usb_ep_autoconfig_reset(cdev->gadget);
1403 	return 0;
1404 
1405 err_purge_funcs:
1406 	purge_configs_funcs(gi);
1407 err_comp_cleanup:
1408 	composite_dev_cleanup(cdev);
1409 	return ret;
1410 }
1411 
1412 static void configfs_composite_unbind(struct usb_gadget *gadget)
1413 {
1414 	struct usb_composite_dev	*cdev;
1415 	struct gadget_info		*gi;
1416 	unsigned long flags;
1417 
1418 	/* the gi->lock is hold by the caller */
1419 
1420 	cdev = get_gadget_data(gadget);
1421 	gi = container_of(cdev, struct gadget_info, cdev);
1422 	spin_lock_irqsave(&gi->spinlock, flags);
1423 	gi->unbind = 1;
1424 	spin_unlock_irqrestore(&gi->spinlock, flags);
1425 
1426 	kfree(otg_desc[0]);
1427 	otg_desc[0] = NULL;
1428 	purge_configs_funcs(gi);
1429 	composite_dev_cleanup(cdev);
1430 	usb_ep_autoconfig_reset(cdev->gadget);
1431 	spin_lock_irqsave(&gi->spinlock, flags);
1432 	cdev->gadget = NULL;
1433 	set_gadget_data(gadget, NULL);
1434 	spin_unlock_irqrestore(&gi->spinlock, flags);
1435 }
1436 
1437 static int configfs_composite_setup(struct usb_gadget *gadget,
1438 		const struct usb_ctrlrequest *ctrl)
1439 {
1440 	struct usb_composite_dev *cdev;
1441 	struct gadget_info *gi;
1442 	unsigned long flags;
1443 	int ret;
1444 
1445 	cdev = get_gadget_data(gadget);
1446 	if (!cdev)
1447 		return 0;
1448 
1449 	gi = container_of(cdev, struct gadget_info, cdev);
1450 	spin_lock_irqsave(&gi->spinlock, flags);
1451 	cdev = get_gadget_data(gadget);
1452 	if (!cdev || gi->unbind) {
1453 		spin_unlock_irqrestore(&gi->spinlock, flags);
1454 		return 0;
1455 	}
1456 
1457 	ret = composite_setup(gadget, ctrl);
1458 	spin_unlock_irqrestore(&gi->spinlock, flags);
1459 	return ret;
1460 }
1461 
1462 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1463 {
1464 	struct usb_composite_dev *cdev;
1465 	struct gadget_info *gi;
1466 	unsigned long flags;
1467 
1468 	cdev = get_gadget_data(gadget);
1469 	if (!cdev)
1470 		return;
1471 
1472 	gi = container_of(cdev, struct gadget_info, cdev);
1473 	spin_lock_irqsave(&gi->spinlock, flags);
1474 	cdev = get_gadget_data(gadget);
1475 	if (!cdev || gi->unbind) {
1476 		spin_unlock_irqrestore(&gi->spinlock, flags);
1477 		return;
1478 	}
1479 
1480 	composite_disconnect(gadget);
1481 	spin_unlock_irqrestore(&gi->spinlock, flags);
1482 }
1483 
1484 static void configfs_composite_suspend(struct usb_gadget *gadget)
1485 {
1486 	struct usb_composite_dev *cdev;
1487 	struct gadget_info *gi;
1488 	unsigned long flags;
1489 
1490 	cdev = get_gadget_data(gadget);
1491 	if (!cdev)
1492 		return;
1493 
1494 	gi = container_of(cdev, struct gadget_info, cdev);
1495 	spin_lock_irqsave(&gi->spinlock, flags);
1496 	cdev = get_gadget_data(gadget);
1497 	if (!cdev || gi->unbind) {
1498 		spin_unlock_irqrestore(&gi->spinlock, flags);
1499 		return;
1500 	}
1501 
1502 	composite_suspend(gadget);
1503 	spin_unlock_irqrestore(&gi->spinlock, flags);
1504 }
1505 
1506 static void configfs_composite_resume(struct usb_gadget *gadget)
1507 {
1508 	struct usb_composite_dev *cdev;
1509 	struct gadget_info *gi;
1510 	unsigned long flags;
1511 
1512 	cdev = get_gadget_data(gadget);
1513 	if (!cdev)
1514 		return;
1515 
1516 	gi = container_of(cdev, struct gadget_info, cdev);
1517 	spin_lock_irqsave(&gi->spinlock, flags);
1518 	cdev = get_gadget_data(gadget);
1519 	if (!cdev || gi->unbind) {
1520 		spin_unlock_irqrestore(&gi->spinlock, flags);
1521 		return;
1522 	}
1523 
1524 	composite_resume(gadget);
1525 	spin_unlock_irqrestore(&gi->spinlock, flags);
1526 }
1527 
1528 static const struct usb_gadget_driver configfs_driver_template = {
1529 	.bind           = configfs_composite_bind,
1530 	.unbind         = configfs_composite_unbind,
1531 
1532 	.setup          = configfs_composite_setup,
1533 	.reset          = configfs_composite_disconnect,
1534 	.disconnect     = configfs_composite_disconnect,
1535 
1536 	.suspend	= configfs_composite_suspend,
1537 	.resume		= configfs_composite_resume,
1538 
1539 	.max_speed	= USB_SPEED_SUPER,
1540 	.driver = {
1541 		.owner          = THIS_MODULE,
1542 		.name		= "configfs-gadget",
1543 	},
1544 	.match_existing_only = 1,
1545 };
1546 
1547 static struct config_group *gadgets_make(
1548 		struct config_group *group,
1549 		const char *name)
1550 {
1551 	struct gadget_info *gi;
1552 
1553 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1554 	if (!gi)
1555 		return ERR_PTR(-ENOMEM);
1556 
1557 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1558 
1559 	config_group_init_type_name(&gi->functions_group, "functions",
1560 			&functions_type);
1561 	configfs_add_default_group(&gi->functions_group, &gi->group);
1562 
1563 	config_group_init_type_name(&gi->configs_group, "configs",
1564 			&config_desc_type);
1565 	configfs_add_default_group(&gi->configs_group, &gi->group);
1566 
1567 	config_group_init_type_name(&gi->strings_group, "strings",
1568 			&gadget_strings_strings_type);
1569 	configfs_add_default_group(&gi->strings_group, &gi->group);
1570 
1571 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1572 			&os_desc_type);
1573 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1574 
1575 	gi->composite.bind = configfs_do_nothing;
1576 	gi->composite.unbind = configfs_do_nothing;
1577 	gi->composite.suspend = NULL;
1578 	gi->composite.resume = NULL;
1579 	gi->composite.max_speed = USB_SPEED_SUPER;
1580 
1581 	spin_lock_init(&gi->spinlock);
1582 	mutex_init(&gi->lock);
1583 	INIT_LIST_HEAD(&gi->string_list);
1584 	INIT_LIST_HEAD(&gi->available_func);
1585 
1586 	composite_init_dev(&gi->cdev);
1587 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1588 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1589 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1590 
1591 	gi->composite.gadget_driver = configfs_driver_template;
1592 
1593 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1594 	gi->composite.name = gi->composite.gadget_driver.function;
1595 
1596 	if (!gi->composite.gadget_driver.function)
1597 		goto err;
1598 
1599 	return &gi->group;
1600 err:
1601 	kfree(gi);
1602 	return ERR_PTR(-ENOMEM);
1603 }
1604 
1605 static void gadgets_drop(struct config_group *group, struct config_item *item)
1606 {
1607 	config_item_put(item);
1608 }
1609 
1610 static struct configfs_group_operations gadgets_ops = {
1611 	.make_group     = &gadgets_make,
1612 	.drop_item      = &gadgets_drop,
1613 };
1614 
1615 static const struct config_item_type gadgets_type = {
1616 	.ct_group_ops   = &gadgets_ops,
1617 	.ct_owner       = THIS_MODULE,
1618 };
1619 
1620 static struct configfs_subsystem gadget_subsys = {
1621 	.su_group = {
1622 		.cg_item = {
1623 			.ci_namebuf = "usb_gadget",
1624 			.ci_type = &gadgets_type,
1625 		},
1626 	},
1627 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1628 };
1629 
1630 void unregister_gadget_item(struct config_item *item)
1631 {
1632 	struct gadget_info *gi = to_gadget_info(item);
1633 
1634 	mutex_lock(&gi->lock);
1635 	unregister_gadget(gi);
1636 	mutex_unlock(&gi->lock);
1637 }
1638 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1639 
1640 static int __init gadget_cfs_init(void)
1641 {
1642 	int ret;
1643 
1644 	config_group_init(&gadget_subsys.su_group);
1645 
1646 	ret = configfs_register_subsystem(&gadget_subsys);
1647 	return ret;
1648 }
1649 module_init(gadget_cfs_init);
1650 
1651 static void __exit gadget_cfs_exit(void)
1652 {
1653 	configfs_unregister_subsystem(&gadget_subsys);
1654 }
1655 module_exit(gadget_cfs_exit);
1656