xref: /linux/drivers/usb/gadget/configfs.c (revision 07f0148aafe8c95a3a76cd59e9e75b4d78d1d31d) 
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/kstrtox.h>
7 #include <linux/nls.h>
8 #include <linux/usb/composite.h>
9 #include <linux/usb/gadget_configfs.h>
10 #include "configfs.h"
11 #include "u_f.h"
12 #include "u_os_desc.h"
13 
14 int check_user_usb_string(const char *name,
15 		struct usb_gadget_strings *stringtab_dev)
16 {
17 	u16 num;
18 	int ret;
19 
20 	ret = kstrtou16(name, 0, &num);
21 	if (ret)
22 		return ret;
23 
24 	if (!usb_validate_langid(num))
25 		return -EINVAL;
26 
27 	stringtab_dev->language = num;
28 	return 0;
29 }
30 
31 #define MAX_NAME_LEN	40
32 #define MAX_USB_STRING_LANGS 2
33 
34 static const struct usb_descriptor_header *otg_desc[2];
35 
36 struct gadget_info {
37 	struct config_group group;
38 	struct config_group functions_group;
39 	struct config_group configs_group;
40 	struct config_group strings_group;
41 	struct config_group os_desc_group;
42 
43 	struct mutex lock;
44 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
45 	struct list_head string_list;
46 	struct list_head available_func;
47 
48 	struct usb_composite_driver composite;
49 	struct usb_composite_dev cdev;
50 	bool use_os_desc;
51 	char b_vendor_code;
52 	char qw_sign[OS_STRING_QW_SIGN_LEN];
53 	spinlock_t spinlock;
54 	bool unbind;
55 };
56 
57 static inline struct gadget_info *to_gadget_info(struct config_item *item)
58 {
59 	return container_of(to_config_group(item), struct gadget_info, group);
60 }
61 
62 struct config_usb_cfg {
63 	struct config_group group;
64 	struct config_group strings_group;
65 	struct list_head string_list;
66 	struct usb_configuration c;
67 	struct list_head func_list;
68 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
69 };
70 
71 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
72 {
73 	return container_of(to_config_group(item), struct config_usb_cfg,
74 			group);
75 }
76 
77 static inline struct gadget_info *cfg_to_gadget_info(struct config_usb_cfg *cfg)
78 {
79 	return container_of(cfg->c.cdev, struct gadget_info, cdev);
80 }
81 
82 struct gadget_strings {
83 	struct usb_gadget_strings stringtab_dev;
84 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
85 	char *manufacturer;
86 	char *product;
87 	char *serialnumber;
88 
89 	struct config_group group;
90 	struct list_head list;
91 };
92 
93 struct gadget_config_name {
94 	struct usb_gadget_strings stringtab_dev;
95 	struct usb_string strings;
96 	char *configuration;
97 
98 	struct config_group group;
99 	struct list_head list;
100 };
101 
102 #define USB_MAX_STRING_WITH_NULL_LEN	(USB_MAX_STRING_LEN+1)
103 
104 static int usb_string_copy(const char *s, char **s_copy)
105 {
106 	int ret;
107 	char *str;
108 	char *copy = *s_copy;
109 	ret = strlen(s);
110 	if (ret > USB_MAX_STRING_LEN)
111 		return -EOVERFLOW;
112 
113 	if (copy) {
114 		str = copy;
115 	} else {
116 		str = kmalloc(USB_MAX_STRING_WITH_NULL_LEN, GFP_KERNEL);
117 		if (!str)
118 			return -ENOMEM;
119 	}
120 	strcpy(str, s);
121 	if (str[ret - 1] == '\n')
122 		str[ret - 1] = '\0';
123 	*s_copy = str;
124 	return 0;
125 }
126 
127 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
128 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
129 			char *page)	\
130 {	\
131 	return sprintf(page, "0x%02x\n", \
132 		to_gadget_info(item)->cdev.desc.__name); \
133 }
134 
135 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
136 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
137 			char *page)	\
138 {	\
139 	return sprintf(page, "0x%04x\n", \
140 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
141 }
142 
143 
144 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
145 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
146 		const char *page, size_t len)		\
147 {							\
148 	u8 val;						\
149 	int ret;					\
150 	ret = kstrtou8(page, 0, &val);			\
151 	if (ret)					\
152 		return ret;				\
153 	to_gadget_info(item)->cdev.desc._name = val;	\
154 	return len;					\
155 }
156 
157 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
158 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
159 		const char *page, size_t len)		\
160 {							\
161 	u16 val;					\
162 	int ret;					\
163 	ret = kstrtou16(page, 0, &val);			\
164 	if (ret)					\
165 		return ret;				\
166 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
167 	return len;					\
168 }
169 
170 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
171 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
172 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
173 
174 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
175 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
176 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
177 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
178 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
179 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
180 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
181 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
182 
183 static ssize_t is_valid_bcd(u16 bcd_val)
184 {
185 	if ((bcd_val & 0xf) > 9)
186 		return -EINVAL;
187 	if (((bcd_val >> 4) & 0xf) > 9)
188 		return -EINVAL;
189 	if (((bcd_val >> 8) & 0xf) > 9)
190 		return -EINVAL;
191 	if (((bcd_val >> 12) & 0xf) > 9)
192 		return -EINVAL;
193 	return 0;
194 }
195 
196 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
197 		const char *page, size_t len)
198 {
199 	u16 bcdDevice;
200 	int ret;
201 
202 	ret = kstrtou16(page, 0, &bcdDevice);
203 	if (ret)
204 		return ret;
205 	ret = is_valid_bcd(bcdDevice);
206 	if (ret)
207 		return ret;
208 
209 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
210 	return len;
211 }
212 
213 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
214 		const char *page, size_t len)
215 {
216 	u16 bcdUSB;
217 	int ret;
218 
219 	ret = kstrtou16(page, 0, &bcdUSB);
220 	if (ret)
221 		return ret;
222 	ret = is_valid_bcd(bcdUSB);
223 	if (ret)
224 		return ret;
225 
226 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
227 	return len;
228 }
229 
230 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
231 {
232 	struct gadget_info *gi = to_gadget_info(item);
233 	char *udc_name;
234 	int ret;
235 
236 	mutex_lock(&gi->lock);
237 	udc_name = gi->composite.gadget_driver.udc_name;
238 	ret = sprintf(page, "%s\n", udc_name ?: "");
239 	mutex_unlock(&gi->lock);
240 
241 	return ret;
242 }
243 
244 static int unregister_gadget(struct gadget_info *gi)
245 {
246 	int ret;
247 
248 	if (!gi->composite.gadget_driver.udc_name)
249 		return -ENODEV;
250 
251 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
252 	if (ret)
253 		return ret;
254 	kfree(gi->composite.gadget_driver.udc_name);
255 	gi->composite.gadget_driver.udc_name = NULL;
256 	return 0;
257 }
258 
259 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
260 		const char *page, size_t len)
261 {
262 	struct gadget_info *gi = to_gadget_info(item);
263 	char *name;
264 	int ret;
265 
266 	if (strlen(page) < len)
267 		return -EOVERFLOW;
268 
269 	name = kstrdup(page, GFP_KERNEL);
270 	if (!name)
271 		return -ENOMEM;
272 	if (name[len - 1] == '\n')
273 		name[len - 1] = '\0';
274 
275 	mutex_lock(&gi->lock);
276 
277 	if (!strlen(name)) {
278 		ret = unregister_gadget(gi);
279 		if (ret)
280 			goto err;
281 		kfree(name);
282 	} else {
283 		if (gi->composite.gadget_driver.udc_name) {
284 			ret = -EBUSY;
285 			goto err;
286 		}
287 		gi->composite.gadget_driver.udc_name = name;
288 		ret = usb_gadget_register_driver(&gi->composite.gadget_driver);
289 		if (ret) {
290 			gi->composite.gadget_driver.udc_name = NULL;
291 			goto err;
292 		}
293 	}
294 	mutex_unlock(&gi->lock);
295 	return len;
296 err:
297 	kfree(name);
298 	mutex_unlock(&gi->lock);
299 	return ret;
300 }
301 
302 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
303 					      char *page)
304 {
305 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
306 
307 	return sprintf(page, "%s\n", usb_speed_string(speed));
308 }
309 
310 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
311 					       const char *page, size_t len)
312 {
313 	struct gadget_info *gi = to_gadget_info(item);
314 
315 	mutex_lock(&gi->lock);
316 
317 	/* Prevent changing of max_speed after the driver is binded */
318 	if (gi->composite.gadget_driver.udc_name)
319 		goto err;
320 
321 	if (strncmp(page, "super-speed-plus", 16) == 0)
322 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
323 	else if (strncmp(page, "super-speed", 11) == 0)
324 		gi->composite.max_speed = USB_SPEED_SUPER;
325 	else if (strncmp(page, "high-speed", 10) == 0)
326 		gi->composite.max_speed = USB_SPEED_HIGH;
327 	else if (strncmp(page, "full-speed", 10) == 0)
328 		gi->composite.max_speed = USB_SPEED_FULL;
329 	else if (strncmp(page, "low-speed", 9) == 0)
330 		gi->composite.max_speed = USB_SPEED_LOW;
331 	else
332 		goto err;
333 
334 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
335 
336 	mutex_unlock(&gi->lock);
337 	return len;
338 err:
339 	mutex_unlock(&gi->lock);
340 	return -EINVAL;
341 }
342 
343 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
344 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
345 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
346 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
347 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
348 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
349 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
350 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
351 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
352 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
353 
354 static struct configfs_attribute *gadget_root_attrs[] = {
355 	&gadget_dev_desc_attr_bDeviceClass,
356 	&gadget_dev_desc_attr_bDeviceSubClass,
357 	&gadget_dev_desc_attr_bDeviceProtocol,
358 	&gadget_dev_desc_attr_bMaxPacketSize0,
359 	&gadget_dev_desc_attr_idVendor,
360 	&gadget_dev_desc_attr_idProduct,
361 	&gadget_dev_desc_attr_bcdDevice,
362 	&gadget_dev_desc_attr_bcdUSB,
363 	&gadget_dev_desc_attr_UDC,
364 	&gadget_dev_desc_attr_max_speed,
365 	NULL,
366 };
367 
368 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
369 {
370 	return container_of(to_config_group(item), struct gadget_strings,
371 			 group);
372 }
373 
374 static inline struct gadget_config_name *to_gadget_config_name(
375 		struct config_item *item)
376 {
377 	return container_of(to_config_group(item), struct gadget_config_name,
378 			 group);
379 }
380 
381 static inline struct usb_function_instance *to_usb_function_instance(
382 		struct config_item *item)
383 {
384 	return container_of(to_config_group(item),
385 			 struct usb_function_instance, group);
386 }
387 
388 static void gadget_info_attr_release(struct config_item *item)
389 {
390 	struct gadget_info *gi = to_gadget_info(item);
391 
392 	WARN_ON(!list_empty(&gi->cdev.configs));
393 	WARN_ON(!list_empty(&gi->string_list));
394 	WARN_ON(!list_empty(&gi->available_func));
395 	kfree(gi->composite.gadget_driver.function);
396 	kfree(gi->composite.gadget_driver.driver.name);
397 	kfree(gi);
398 }
399 
400 static struct configfs_item_operations gadget_root_item_ops = {
401 	.release                = gadget_info_attr_release,
402 };
403 
404 static void gadget_config_attr_release(struct config_item *item)
405 {
406 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
407 
408 	WARN_ON(!list_empty(&cfg->c.functions));
409 	list_del(&cfg->c.list);
410 	kfree(cfg->c.label);
411 	kfree(cfg);
412 }
413 
414 static int config_usb_cfg_link(
415 	struct config_item *usb_cfg_ci,
416 	struct config_item *usb_func_ci)
417 {
418 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
419 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
420 
421 	struct usb_function_instance *fi =
422 			to_usb_function_instance(usb_func_ci);
423 	struct usb_function_instance *a_fi = NULL, *iter;
424 	struct usb_function *f;
425 	int ret;
426 
427 	mutex_lock(&gi->lock);
428 	/*
429 	 * Make sure this function is from within our _this_ gadget and not
430 	 * from another gadget or a random directory.
431 	 * Also a function instance can only be linked once.
432 	 */
433 	list_for_each_entry(iter, &gi->available_func, cfs_list) {
434 		if (iter != fi)
435 			continue;
436 		a_fi = iter;
437 		break;
438 	}
439 	if (!a_fi) {
440 		ret = -EINVAL;
441 		goto out;
442 	}
443 
444 	list_for_each_entry(f, &cfg->func_list, list) {
445 		if (f->fi == fi) {
446 			ret = -EEXIST;
447 			goto out;
448 		}
449 	}
450 
451 	f = usb_get_function(fi);
452 	if (IS_ERR(f)) {
453 		ret = PTR_ERR(f);
454 		goto out;
455 	}
456 
457 	/* stash the function until we bind it to the gadget */
458 	list_add_tail(&f->list, &cfg->func_list);
459 	ret = 0;
460 out:
461 	mutex_unlock(&gi->lock);
462 	return ret;
463 }
464 
465 static void config_usb_cfg_unlink(
466 	struct config_item *usb_cfg_ci,
467 	struct config_item *usb_func_ci)
468 {
469 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
470 	struct gadget_info *gi = cfg_to_gadget_info(cfg);
471 
472 	struct usb_function_instance *fi =
473 			to_usb_function_instance(usb_func_ci);
474 	struct usb_function *f;
475 
476 	/*
477 	 * ideally I would like to forbid to unlink functions while a gadget is
478 	 * bound to an UDC. Since this isn't possible at the moment, we simply
479 	 * force an unbind, the function is available here and then we can
480 	 * remove the function.
481 	 */
482 	mutex_lock(&gi->lock);
483 	if (gi->composite.gadget_driver.udc_name)
484 		unregister_gadget(gi);
485 	WARN_ON(gi->composite.gadget_driver.udc_name);
486 
487 	list_for_each_entry(f, &cfg->func_list, list) {
488 		if (f->fi == fi) {
489 			list_del(&f->list);
490 			usb_put_function(f);
491 			mutex_unlock(&gi->lock);
492 			return;
493 		}
494 	}
495 	mutex_unlock(&gi->lock);
496 	WARN(1, "Unable to locate function to unbind\n");
497 }
498 
499 static struct configfs_item_operations gadget_config_item_ops = {
500 	.release                = gadget_config_attr_release,
501 	.allow_link             = config_usb_cfg_link,
502 	.drop_link              = config_usb_cfg_unlink,
503 };
504 
505 
506 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
507 		char *page)
508 {
509 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
510 
511 	return sprintf(page, "%u\n", cfg->c.MaxPower);
512 }
513 
514 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
515 		const char *page, size_t len)
516 {
517 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
518 	u16 val;
519 	int ret;
520 	ret = kstrtou16(page, 0, &val);
521 	if (ret)
522 		return ret;
523 	if (DIV_ROUND_UP(val, 8) > 0xff)
524 		return -ERANGE;
525 	cfg->c.MaxPower = val;
526 	return len;
527 }
528 
529 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
530 		char *page)
531 {
532 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
533 
534 	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
535 }
536 
537 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
538 		const char *page, size_t len)
539 {
540 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
541 	u8 val;
542 	int ret;
543 	ret = kstrtou8(page, 0, &val);
544 	if (ret)
545 		return ret;
546 	if (!(val & USB_CONFIG_ATT_ONE))
547 		return -EINVAL;
548 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
549 				USB_CONFIG_ATT_WAKEUP))
550 		return -EINVAL;
551 	cfg->c.bmAttributes = val;
552 	return len;
553 }
554 
555 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
556 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
557 
558 static struct configfs_attribute *gadget_config_attrs[] = {
559 	&gadget_config_desc_attr_MaxPower,
560 	&gadget_config_desc_attr_bmAttributes,
561 	NULL,
562 };
563 
564 static const struct config_item_type gadget_config_type = {
565 	.ct_item_ops	= &gadget_config_item_ops,
566 	.ct_attrs	= gadget_config_attrs,
567 	.ct_owner	= THIS_MODULE,
568 };
569 
570 static const struct config_item_type gadget_root_type = {
571 	.ct_item_ops	= &gadget_root_item_ops,
572 	.ct_attrs	= gadget_root_attrs,
573 	.ct_owner	= THIS_MODULE,
574 };
575 
576 static void composite_init_dev(struct usb_composite_dev *cdev)
577 {
578 	spin_lock_init(&cdev->lock);
579 	INIT_LIST_HEAD(&cdev->configs);
580 	INIT_LIST_HEAD(&cdev->gstrings);
581 }
582 
583 static struct config_group *function_make(
584 		struct config_group *group,
585 		const char *name)
586 {
587 	struct gadget_info *gi;
588 	struct usb_function_instance *fi;
589 	char buf[MAX_NAME_LEN];
590 	char *func_name;
591 	char *instance_name;
592 	int ret;
593 
594 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
595 	if (ret >= MAX_NAME_LEN)
596 		return ERR_PTR(-ENAMETOOLONG);
597 
598 	func_name = buf;
599 	instance_name = strchr(func_name, '.');
600 	if (!instance_name) {
601 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
602 		return ERR_PTR(-EINVAL);
603 	}
604 	*instance_name = '\0';
605 	instance_name++;
606 
607 	fi = usb_get_function_instance(func_name);
608 	if (IS_ERR(fi))
609 		return ERR_CAST(fi);
610 
611 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
612 	if (ret) {
613 		usb_put_function_instance(fi);
614 		return ERR_PTR(ret);
615 	}
616 	if (fi->set_inst_name) {
617 		ret = fi->set_inst_name(fi, instance_name);
618 		if (ret) {
619 			usb_put_function_instance(fi);
620 			return ERR_PTR(ret);
621 		}
622 	}
623 
624 	gi = container_of(group, struct gadget_info, functions_group);
625 
626 	mutex_lock(&gi->lock);
627 	list_add_tail(&fi->cfs_list, &gi->available_func);
628 	mutex_unlock(&gi->lock);
629 	return &fi->group;
630 }
631 
632 static void function_drop(
633 		struct config_group *group,
634 		struct config_item *item)
635 {
636 	struct usb_function_instance *fi = to_usb_function_instance(item);
637 	struct gadget_info *gi;
638 
639 	gi = container_of(group, struct gadget_info, functions_group);
640 
641 	mutex_lock(&gi->lock);
642 	list_del(&fi->cfs_list);
643 	mutex_unlock(&gi->lock);
644 	config_item_put(item);
645 }
646 
647 static struct configfs_group_operations functions_ops = {
648 	.make_group     = &function_make,
649 	.drop_item      = &function_drop,
650 };
651 
652 static const struct config_item_type functions_type = {
653 	.ct_group_ops   = &functions_ops,
654 	.ct_owner       = THIS_MODULE,
655 };
656 
657 GS_STRINGS_RW(gadget_config_name, configuration);
658 
659 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
660 	&gadget_config_name_attr_configuration,
661 	NULL,
662 };
663 
664 static void gadget_config_name_attr_release(struct config_item *item)
665 {
666 	struct gadget_config_name *cn = to_gadget_config_name(item);
667 
668 	kfree(cn->configuration);
669 
670 	list_del(&cn->list);
671 	kfree(cn);
672 }
673 
674 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
675 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
676 
677 static struct config_group *config_desc_make(
678 		struct config_group *group,
679 		const char *name)
680 {
681 	struct gadget_info *gi;
682 	struct config_usb_cfg *cfg;
683 	char buf[MAX_NAME_LEN];
684 	char *num_str;
685 	u8 num;
686 	int ret;
687 
688 	gi = container_of(group, struct gadget_info, configs_group);
689 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
690 	if (ret >= MAX_NAME_LEN)
691 		return ERR_PTR(-ENAMETOOLONG);
692 
693 	num_str = strchr(buf, '.');
694 	if (!num_str) {
695 		pr_err("Unable to locate . in name.bConfigurationValue\n");
696 		return ERR_PTR(-EINVAL);
697 	}
698 
699 	*num_str = '\0';
700 	num_str++;
701 
702 	if (!strlen(buf))
703 		return ERR_PTR(-EINVAL);
704 
705 	ret = kstrtou8(num_str, 0, &num);
706 	if (ret)
707 		return ERR_PTR(ret);
708 
709 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
710 	if (!cfg)
711 		return ERR_PTR(-ENOMEM);
712 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
713 	if (!cfg->c.label) {
714 		ret = -ENOMEM;
715 		goto err;
716 	}
717 	cfg->c.bConfigurationValue = num;
718 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
719 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
720 	INIT_LIST_HEAD(&cfg->string_list);
721 	INIT_LIST_HEAD(&cfg->func_list);
722 
723 	config_group_init_type_name(&cfg->group, name,
724 				&gadget_config_type);
725 
726 	config_group_init_type_name(&cfg->strings_group, "strings",
727 			&gadget_config_name_strings_type);
728 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
729 
730 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
731 	if (ret)
732 		goto err;
733 
734 	return &cfg->group;
735 err:
736 	kfree(cfg->c.label);
737 	kfree(cfg);
738 	return ERR_PTR(ret);
739 }
740 
741 static void config_desc_drop(
742 		struct config_group *group,
743 		struct config_item *item)
744 {
745 	config_item_put(item);
746 }
747 
748 static struct configfs_group_operations config_desc_ops = {
749 	.make_group     = &config_desc_make,
750 	.drop_item      = &config_desc_drop,
751 };
752 
753 static const struct config_item_type config_desc_type = {
754 	.ct_group_ops   = &config_desc_ops,
755 	.ct_owner       = THIS_MODULE,
756 };
757 
758 GS_STRINGS_RW(gadget_strings, manufacturer);
759 GS_STRINGS_RW(gadget_strings, product);
760 GS_STRINGS_RW(gadget_strings, serialnumber);
761 
762 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
763 	&gadget_strings_attr_manufacturer,
764 	&gadget_strings_attr_product,
765 	&gadget_strings_attr_serialnumber,
766 	NULL,
767 };
768 
769 static void gadget_strings_attr_release(struct config_item *item)
770 {
771 	struct gadget_strings *gs = to_gadget_strings(item);
772 
773 	kfree(gs->manufacturer);
774 	kfree(gs->product);
775 	kfree(gs->serialnumber);
776 
777 	list_del(&gs->list);
778 	kfree(gs);
779 }
780 
781 USB_CONFIG_STRING_RW_OPS(gadget_strings);
782 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
783 
784 static inline struct gadget_info *os_desc_item_to_gadget_info(
785 		struct config_item *item)
786 {
787 	return container_of(to_config_group(item),
788 			struct gadget_info, os_desc_group);
789 }
790 
791 static ssize_t os_desc_use_show(struct config_item *item, char *page)
792 {
793 	return sprintf(page, "%d\n",
794 			os_desc_item_to_gadget_info(item)->use_os_desc);
795 }
796 
797 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
798 				 size_t len)
799 {
800 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
801 	int ret;
802 	bool use;
803 
804 	mutex_lock(&gi->lock);
805 	ret = kstrtobool(page, &use);
806 	if (!ret) {
807 		gi->use_os_desc = use;
808 		ret = len;
809 	}
810 	mutex_unlock(&gi->lock);
811 
812 	return ret;
813 }
814 
815 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
816 {
817 	return sprintf(page, "0x%02x\n",
818 			os_desc_item_to_gadget_info(item)->b_vendor_code);
819 }
820 
821 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
822 					   const char *page, size_t len)
823 {
824 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
825 	int ret;
826 	u8 b_vendor_code;
827 
828 	mutex_lock(&gi->lock);
829 	ret = kstrtou8(page, 0, &b_vendor_code);
830 	if (!ret) {
831 		gi->b_vendor_code = b_vendor_code;
832 		ret = len;
833 	}
834 	mutex_unlock(&gi->lock);
835 
836 	return ret;
837 }
838 
839 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
840 {
841 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
842 	int res;
843 
844 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
845 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
846 	page[res++] = '\n';
847 
848 	return res;
849 }
850 
851 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
852 				     size_t len)
853 {
854 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
855 	int res, l;
856 
857 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
858 	if (page[l - 1] == '\n')
859 		--l;
860 
861 	mutex_lock(&gi->lock);
862 	res = utf8s_to_utf16s(page, l,
863 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
864 			      OS_STRING_QW_SIGN_LEN);
865 	if (res > 0)
866 		res = len;
867 	mutex_unlock(&gi->lock);
868 
869 	return res;
870 }
871 
872 CONFIGFS_ATTR(os_desc_, use);
873 CONFIGFS_ATTR(os_desc_, b_vendor_code);
874 CONFIGFS_ATTR(os_desc_, qw_sign);
875 
876 static struct configfs_attribute *os_desc_attrs[] = {
877 	&os_desc_attr_use,
878 	&os_desc_attr_b_vendor_code,
879 	&os_desc_attr_qw_sign,
880 	NULL,
881 };
882 
883 static int os_desc_link(struct config_item *os_desc_ci,
884 			struct config_item *usb_cfg_ci)
885 {
886 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
887 	struct usb_composite_dev *cdev = &gi->cdev;
888 	struct config_usb_cfg *c_target = to_config_usb_cfg(usb_cfg_ci);
889 	struct usb_configuration *c = NULL, *iter;
890 	int ret;
891 
892 	mutex_lock(&gi->lock);
893 	list_for_each_entry(iter, &cdev->configs, list) {
894 		if (iter != &c_target->c)
895 			continue;
896 		c = iter;
897 		break;
898 	}
899 	if (!c) {
900 		ret = -EINVAL;
901 		goto out;
902 	}
903 
904 	if (cdev->os_desc_config) {
905 		ret = -EBUSY;
906 		goto out;
907 	}
908 
909 	cdev->os_desc_config = &c_target->c;
910 	ret = 0;
911 
912 out:
913 	mutex_unlock(&gi->lock);
914 	return ret;
915 }
916 
917 static void os_desc_unlink(struct config_item *os_desc_ci,
918 			  struct config_item *usb_cfg_ci)
919 {
920 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
921 	struct usb_composite_dev *cdev = &gi->cdev;
922 
923 	mutex_lock(&gi->lock);
924 	if (gi->composite.gadget_driver.udc_name)
925 		unregister_gadget(gi);
926 	cdev->os_desc_config = NULL;
927 	WARN_ON(gi->composite.gadget_driver.udc_name);
928 	mutex_unlock(&gi->lock);
929 }
930 
931 static struct configfs_item_operations os_desc_ops = {
932 	.allow_link		= os_desc_link,
933 	.drop_link		= os_desc_unlink,
934 };
935 
936 static struct config_item_type os_desc_type = {
937 	.ct_item_ops	= &os_desc_ops,
938 	.ct_attrs	= os_desc_attrs,
939 	.ct_owner	= THIS_MODULE,
940 };
941 
942 static inline struct usb_os_desc_ext_prop
943 *to_usb_os_desc_ext_prop(struct config_item *item)
944 {
945 	return container_of(item, struct usb_os_desc_ext_prop, item);
946 }
947 
948 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
949 {
950 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
951 }
952 
953 static ssize_t ext_prop_type_store(struct config_item *item,
954 				   const char *page, size_t len)
955 {
956 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
957 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
958 	u8 type;
959 	int ret;
960 
961 	if (desc->opts_mutex)
962 		mutex_lock(desc->opts_mutex);
963 	ret = kstrtou8(page, 0, &type);
964 	if (ret)
965 		goto end;
966 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
967 		ret = -EINVAL;
968 		goto end;
969 	}
970 
971 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
972 	    ext_prop->type == USB_EXT_PROP_LE32 ||
973 	    ext_prop->type == USB_EXT_PROP_BE32) &&
974 	    (type == USB_EXT_PROP_UNICODE ||
975 	    type == USB_EXT_PROP_UNICODE_ENV ||
976 	    type == USB_EXT_PROP_UNICODE_LINK))
977 		ext_prop->data_len <<= 1;
978 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
979 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
980 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
981 		   (type == USB_EXT_PROP_BINARY ||
982 		   type == USB_EXT_PROP_LE32 ||
983 		   type == USB_EXT_PROP_BE32))
984 		ext_prop->data_len >>= 1;
985 	ext_prop->type = type;
986 	ret = len;
987 
988 end:
989 	if (desc->opts_mutex)
990 		mutex_unlock(desc->opts_mutex);
991 	return ret;
992 }
993 
994 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
995 {
996 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
997 	int len = ext_prop->data_len;
998 
999 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1000 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1001 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1002 		len >>= 1;
1003 	memcpy(page, ext_prop->data, len);
1004 
1005 	return len;
1006 }
1007 
1008 static ssize_t ext_prop_data_store(struct config_item *item,
1009 				   const char *page, size_t len)
1010 {
1011 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1012 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1013 	char *new_data;
1014 	size_t ret_len = len;
1015 
1016 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1017 		--len;
1018 	new_data = kmemdup(page, len, GFP_KERNEL);
1019 	if (!new_data)
1020 		return -ENOMEM;
1021 
1022 	if (desc->opts_mutex)
1023 		mutex_lock(desc->opts_mutex);
1024 	kfree(ext_prop->data);
1025 	ext_prop->data = new_data;
1026 	desc->ext_prop_len -= ext_prop->data_len;
1027 	ext_prop->data_len = len;
1028 	desc->ext_prop_len += ext_prop->data_len;
1029 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1030 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1031 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1032 		desc->ext_prop_len -= ext_prop->data_len;
1033 		ext_prop->data_len <<= 1;
1034 		ext_prop->data_len += 2;
1035 		desc->ext_prop_len += ext_prop->data_len;
1036 	}
1037 	if (desc->opts_mutex)
1038 		mutex_unlock(desc->opts_mutex);
1039 	return ret_len;
1040 }
1041 
1042 CONFIGFS_ATTR(ext_prop_, type);
1043 CONFIGFS_ATTR(ext_prop_, data);
1044 
1045 static struct configfs_attribute *ext_prop_attrs[] = {
1046 	&ext_prop_attr_type,
1047 	&ext_prop_attr_data,
1048 	NULL,
1049 };
1050 
1051 static void usb_os_desc_ext_prop_release(struct config_item *item)
1052 {
1053 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1054 
1055 	kfree(ext_prop); /* frees a whole chunk */
1056 }
1057 
1058 static struct configfs_item_operations ext_prop_ops = {
1059 	.release		= usb_os_desc_ext_prop_release,
1060 };
1061 
1062 static struct config_item *ext_prop_make(
1063 		struct config_group *group,
1064 		const char *name)
1065 {
1066 	struct usb_os_desc_ext_prop *ext_prop;
1067 	struct config_item_type *ext_prop_type;
1068 	struct usb_os_desc *desc;
1069 	char *vlabuf;
1070 
1071 	vla_group(data_chunk);
1072 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1073 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1074 
1075 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1076 	if (!vlabuf)
1077 		return ERR_PTR(-ENOMEM);
1078 
1079 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1080 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1081 
1082 	desc = container_of(group, struct usb_os_desc, group);
1083 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1084 	ext_prop_type->ct_attrs = ext_prop_attrs;
1085 	ext_prop_type->ct_owner = desc->owner;
1086 
1087 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1088 
1089 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1090 	if (!ext_prop->name) {
1091 		kfree(vlabuf);
1092 		return ERR_PTR(-ENOMEM);
1093 	}
1094 	desc->ext_prop_len += 14;
1095 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1096 	if (desc->opts_mutex)
1097 		mutex_lock(desc->opts_mutex);
1098 	desc->ext_prop_len += ext_prop->name_len;
1099 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1100 	++desc->ext_prop_count;
1101 	if (desc->opts_mutex)
1102 		mutex_unlock(desc->opts_mutex);
1103 
1104 	return &ext_prop->item;
1105 }
1106 
1107 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1108 {
1109 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1110 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1111 
1112 	if (desc->opts_mutex)
1113 		mutex_lock(desc->opts_mutex);
1114 	list_del(&ext_prop->entry);
1115 	--desc->ext_prop_count;
1116 	kfree(ext_prop->name);
1117 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1118 	if (desc->opts_mutex)
1119 		mutex_unlock(desc->opts_mutex);
1120 	config_item_put(item);
1121 }
1122 
1123 static struct configfs_group_operations interf_grp_ops = {
1124 	.make_item	= &ext_prop_make,
1125 	.drop_item	= &ext_prop_drop,
1126 };
1127 
1128 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1129 					     char *page)
1130 {
1131 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1132 	return 8;
1133 }
1134 
1135 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1136 					      const char *page, size_t len)
1137 {
1138 	struct usb_os_desc *desc = to_usb_os_desc(item);
1139 	int l;
1140 
1141 	l = min_t(int, 8, len);
1142 	if (page[l - 1] == '\n')
1143 		--l;
1144 	if (desc->opts_mutex)
1145 		mutex_lock(desc->opts_mutex);
1146 	memcpy(desc->ext_compat_id, page, l);
1147 
1148 	if (desc->opts_mutex)
1149 		mutex_unlock(desc->opts_mutex);
1150 
1151 	return len;
1152 }
1153 
1154 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1155 						 char *page)
1156 {
1157 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1158 	return 8;
1159 }
1160 
1161 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1162 						  const char *page, size_t len)
1163 {
1164 	struct usb_os_desc *desc = to_usb_os_desc(item);
1165 	int l;
1166 
1167 	l = min_t(int, 8, len);
1168 	if (page[l - 1] == '\n')
1169 		--l;
1170 	if (desc->opts_mutex)
1171 		mutex_lock(desc->opts_mutex);
1172 	memcpy(desc->ext_compat_id + 8, page, l);
1173 
1174 	if (desc->opts_mutex)
1175 		mutex_unlock(desc->opts_mutex);
1176 
1177 	return len;
1178 }
1179 
1180 CONFIGFS_ATTR(interf_grp_, compatible_id);
1181 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1182 
1183 static struct configfs_attribute *interf_grp_attrs[] = {
1184 	&interf_grp_attr_compatible_id,
1185 	&interf_grp_attr_sub_compatible_id,
1186 	NULL
1187 };
1188 
1189 struct config_group *usb_os_desc_prepare_interf_dir(
1190 		struct config_group *parent,
1191 		int n_interf,
1192 		struct usb_os_desc **desc,
1193 		char **names,
1194 		struct module *owner)
1195 {
1196 	struct config_group *os_desc_group;
1197 	struct config_item_type *os_desc_type, *interface_type;
1198 
1199 	vla_group(data_chunk);
1200 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1201 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1202 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1203 
1204 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1205 	if (!vlabuf)
1206 		return ERR_PTR(-ENOMEM);
1207 
1208 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1209 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1210 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1211 
1212 	os_desc_type->ct_owner = owner;
1213 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1214 	configfs_add_default_group(os_desc_group, parent);
1215 
1216 	interface_type->ct_group_ops = &interf_grp_ops;
1217 	interface_type->ct_attrs = interf_grp_attrs;
1218 	interface_type->ct_owner = owner;
1219 
1220 	while (n_interf--) {
1221 		struct usb_os_desc *d;
1222 
1223 		d = desc[n_interf];
1224 		d->owner = owner;
1225 		config_group_init_type_name(&d->group, "", interface_type);
1226 		config_item_set_name(&d->group.cg_item, "interface.%s",
1227 				     names[n_interf]);
1228 		configfs_add_default_group(&d->group, os_desc_group);
1229 	}
1230 
1231 	return os_desc_group;
1232 }
1233 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1234 
1235 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1236 {
1237 	WARN_ON(1);
1238 	return -EINVAL;
1239 }
1240 
1241 int composite_dev_prepare(struct usb_composite_driver *composite,
1242 		struct usb_composite_dev *dev);
1243 
1244 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1245 				  struct usb_ep *ep0);
1246 
1247 static void purge_configs_funcs(struct gadget_info *gi)
1248 {
1249 	struct usb_configuration	*c;
1250 
1251 	list_for_each_entry(c, &gi->cdev.configs, list) {
1252 		struct usb_function *f, *tmp;
1253 		struct config_usb_cfg *cfg;
1254 
1255 		cfg = container_of(c, struct config_usb_cfg, c);
1256 
1257 		list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) {
1258 
1259 			list_move(&f->list, &cfg->func_list);
1260 			if (f->unbind) {
1261 				dev_dbg(&gi->cdev.gadget->dev,
1262 					"unbind function '%s'/%p\n",
1263 					f->name, f);
1264 				f->unbind(c, f);
1265 			}
1266 		}
1267 		c->next_interface_id = 0;
1268 		memset(c->interface, 0, sizeof(c->interface));
1269 		c->superspeed_plus = 0;
1270 		c->superspeed = 0;
1271 		c->highspeed = 0;
1272 		c->fullspeed = 0;
1273 	}
1274 }
1275 
1276 static int configfs_composite_bind(struct usb_gadget *gadget,
1277 		struct usb_gadget_driver *gdriver)
1278 {
1279 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1280 	struct gadget_info		*gi = container_of(composite,
1281 						struct gadget_info, composite);
1282 	struct usb_composite_dev	*cdev = &gi->cdev;
1283 	struct usb_configuration	*c;
1284 	struct usb_string		*s;
1285 	unsigned			i;
1286 	int				ret;
1287 
1288 	/* the gi->lock is hold by the caller */
1289 	gi->unbind = 0;
1290 	cdev->gadget = gadget;
1291 	set_gadget_data(gadget, cdev);
1292 	ret = composite_dev_prepare(composite, cdev);
1293 	if (ret)
1294 		return ret;
1295 	/* and now the gadget bind */
1296 	ret = -EINVAL;
1297 
1298 	if (list_empty(&gi->cdev.configs)) {
1299 		pr_err("Need at least one configuration in %s.\n",
1300 				gi->composite.name);
1301 		goto err_comp_cleanup;
1302 	}
1303 
1304 
1305 	list_for_each_entry(c, &gi->cdev.configs, list) {
1306 		struct config_usb_cfg *cfg;
1307 
1308 		cfg = container_of(c, struct config_usb_cfg, c);
1309 		if (list_empty(&cfg->func_list)) {
1310 			pr_err("Config %s/%d of %s needs at least one function.\n",
1311 			      c->label, c->bConfigurationValue,
1312 			      gi->composite.name);
1313 			goto err_comp_cleanup;
1314 		}
1315 	}
1316 
1317 	/* init all strings */
1318 	if (!list_empty(&gi->string_list)) {
1319 		struct gadget_strings *gs;
1320 
1321 		i = 0;
1322 		list_for_each_entry(gs, &gi->string_list, list) {
1323 
1324 			gi->gstrings[i] = &gs->stringtab_dev;
1325 			gs->stringtab_dev.strings = gs->strings;
1326 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1327 				gs->manufacturer;
1328 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1329 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1330 			i++;
1331 		}
1332 		gi->gstrings[i] = NULL;
1333 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1334 				USB_GADGET_FIRST_AVAIL_IDX);
1335 		if (IS_ERR(s)) {
1336 			ret = PTR_ERR(s);
1337 			goto err_comp_cleanup;
1338 		}
1339 
1340 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1341 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1342 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1343 	}
1344 
1345 	if (gi->use_os_desc) {
1346 		cdev->use_os_string = true;
1347 		cdev->b_vendor_code = gi->b_vendor_code;
1348 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1349 	}
1350 
1351 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1352 		struct usb_descriptor_header *usb_desc;
1353 
1354 		usb_desc = usb_otg_descriptor_alloc(gadget);
1355 		if (!usb_desc) {
1356 			ret = -ENOMEM;
1357 			goto err_comp_cleanup;
1358 		}
1359 		usb_otg_descriptor_init(gadget, usb_desc);
1360 		otg_desc[0] = usb_desc;
1361 		otg_desc[1] = NULL;
1362 	}
1363 
1364 	/* Go through all configs, attach all functions */
1365 	list_for_each_entry(c, &gi->cdev.configs, list) {
1366 		struct config_usb_cfg *cfg;
1367 		struct usb_function *f;
1368 		struct usb_function *tmp;
1369 		struct gadget_config_name *cn;
1370 
1371 		if (gadget_is_otg(gadget))
1372 			c->descriptors = otg_desc;
1373 
1374 		cfg = container_of(c, struct config_usb_cfg, c);
1375 		if (!list_empty(&cfg->string_list)) {
1376 			i = 0;
1377 			list_for_each_entry(cn, &cfg->string_list, list) {
1378 				cfg->gstrings[i] = &cn->stringtab_dev;
1379 				cn->stringtab_dev.strings = &cn->strings;
1380 				cn->strings.s = cn->configuration;
1381 				i++;
1382 			}
1383 			cfg->gstrings[i] = NULL;
1384 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1385 			if (IS_ERR(s)) {
1386 				ret = PTR_ERR(s);
1387 				goto err_comp_cleanup;
1388 			}
1389 			c->iConfiguration = s[0].id;
1390 		}
1391 
1392 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1393 			list_del(&f->list);
1394 			ret = usb_add_function(c, f);
1395 			if (ret) {
1396 				list_add(&f->list, &cfg->func_list);
1397 				goto err_purge_funcs;
1398 			}
1399 		}
1400 		ret = usb_gadget_check_config(cdev->gadget);
1401 		if (ret)
1402 			goto err_purge_funcs;
1403 
1404 		usb_ep_autoconfig_reset(cdev->gadget);
1405 	}
1406 	if (cdev->use_os_string) {
1407 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1408 		if (ret)
1409 			goto err_purge_funcs;
1410 	}
1411 
1412 	usb_ep_autoconfig_reset(cdev->gadget);
1413 	return 0;
1414 
1415 err_purge_funcs:
1416 	purge_configs_funcs(gi);
1417 err_comp_cleanup:
1418 	composite_dev_cleanup(cdev);
1419 	return ret;
1420 }
1421 
1422 static void configfs_composite_unbind(struct usb_gadget *gadget)
1423 {
1424 	struct usb_composite_dev	*cdev;
1425 	struct gadget_info		*gi;
1426 	unsigned long flags;
1427 
1428 	/* the gi->lock is hold by the caller */
1429 
1430 	cdev = get_gadget_data(gadget);
1431 	gi = container_of(cdev, struct gadget_info, cdev);
1432 	spin_lock_irqsave(&gi->spinlock, flags);
1433 	gi->unbind = 1;
1434 	spin_unlock_irqrestore(&gi->spinlock, flags);
1435 
1436 	kfree(otg_desc[0]);
1437 	otg_desc[0] = NULL;
1438 	purge_configs_funcs(gi);
1439 	composite_dev_cleanup(cdev);
1440 	usb_ep_autoconfig_reset(cdev->gadget);
1441 	spin_lock_irqsave(&gi->spinlock, flags);
1442 	cdev->gadget = NULL;
1443 	cdev->deactivations = 0;
1444 	gadget->deactivated = false;
1445 	set_gadget_data(gadget, NULL);
1446 	spin_unlock_irqrestore(&gi->spinlock, flags);
1447 }
1448 
1449 static int configfs_composite_setup(struct usb_gadget *gadget,
1450 		const struct usb_ctrlrequest *ctrl)
1451 {
1452 	struct usb_composite_dev *cdev;
1453 	struct gadget_info *gi;
1454 	unsigned long flags;
1455 	int ret;
1456 
1457 	cdev = get_gadget_data(gadget);
1458 	if (!cdev)
1459 		return 0;
1460 
1461 	gi = container_of(cdev, struct gadget_info, cdev);
1462 	spin_lock_irqsave(&gi->spinlock, flags);
1463 	cdev = get_gadget_data(gadget);
1464 	if (!cdev || gi->unbind) {
1465 		spin_unlock_irqrestore(&gi->spinlock, flags);
1466 		return 0;
1467 	}
1468 
1469 	ret = composite_setup(gadget, ctrl);
1470 	spin_unlock_irqrestore(&gi->spinlock, flags);
1471 	return ret;
1472 }
1473 
1474 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1475 {
1476 	struct usb_composite_dev *cdev;
1477 	struct gadget_info *gi;
1478 	unsigned long flags;
1479 
1480 	cdev = get_gadget_data(gadget);
1481 	if (!cdev)
1482 		return;
1483 
1484 	gi = container_of(cdev, struct gadget_info, cdev);
1485 	spin_lock_irqsave(&gi->spinlock, flags);
1486 	cdev = get_gadget_data(gadget);
1487 	if (!cdev || gi->unbind) {
1488 		spin_unlock_irqrestore(&gi->spinlock, flags);
1489 		return;
1490 	}
1491 
1492 	composite_disconnect(gadget);
1493 	spin_unlock_irqrestore(&gi->spinlock, flags);
1494 }
1495 
1496 static void configfs_composite_reset(struct usb_gadget *gadget)
1497 {
1498 	struct usb_composite_dev *cdev;
1499 	struct gadget_info *gi;
1500 	unsigned long flags;
1501 
1502 	cdev = get_gadget_data(gadget);
1503 	if (!cdev)
1504 		return;
1505 
1506 	gi = container_of(cdev, struct gadget_info, cdev);
1507 	spin_lock_irqsave(&gi->spinlock, flags);
1508 	cdev = get_gadget_data(gadget);
1509 	if (!cdev || gi->unbind) {
1510 		spin_unlock_irqrestore(&gi->spinlock, flags);
1511 		return;
1512 	}
1513 
1514 	composite_reset(gadget);
1515 	spin_unlock_irqrestore(&gi->spinlock, flags);
1516 }
1517 
1518 static void configfs_composite_suspend(struct usb_gadget *gadget)
1519 {
1520 	struct usb_composite_dev *cdev;
1521 	struct gadget_info *gi;
1522 	unsigned long flags;
1523 
1524 	cdev = get_gadget_data(gadget);
1525 	if (!cdev)
1526 		return;
1527 
1528 	gi = container_of(cdev, struct gadget_info, cdev);
1529 	spin_lock_irqsave(&gi->spinlock, flags);
1530 	cdev = get_gadget_data(gadget);
1531 	if (!cdev || gi->unbind) {
1532 		spin_unlock_irqrestore(&gi->spinlock, flags);
1533 		return;
1534 	}
1535 
1536 	composite_suspend(gadget);
1537 	spin_unlock_irqrestore(&gi->spinlock, flags);
1538 }
1539 
1540 static void configfs_composite_resume(struct usb_gadget *gadget)
1541 {
1542 	struct usb_composite_dev *cdev;
1543 	struct gadget_info *gi;
1544 	unsigned long flags;
1545 
1546 	cdev = get_gadget_data(gadget);
1547 	if (!cdev)
1548 		return;
1549 
1550 	gi = container_of(cdev, struct gadget_info, cdev);
1551 	spin_lock_irqsave(&gi->spinlock, flags);
1552 	cdev = get_gadget_data(gadget);
1553 	if (!cdev || gi->unbind) {
1554 		spin_unlock_irqrestore(&gi->spinlock, flags);
1555 		return;
1556 	}
1557 
1558 	composite_resume(gadget);
1559 	spin_unlock_irqrestore(&gi->spinlock, flags);
1560 }
1561 
1562 static const struct usb_gadget_driver configfs_driver_template = {
1563 	.bind           = configfs_composite_bind,
1564 	.unbind         = configfs_composite_unbind,
1565 
1566 	.setup          = configfs_composite_setup,
1567 	.reset          = configfs_composite_reset,
1568 	.disconnect     = configfs_composite_disconnect,
1569 
1570 	.suspend	= configfs_composite_suspend,
1571 	.resume		= configfs_composite_resume,
1572 
1573 	.max_speed	= USB_SPEED_SUPER_PLUS,
1574 	.driver = {
1575 		.owner          = THIS_MODULE,
1576 	},
1577 	.match_existing_only = 1,
1578 };
1579 
1580 static struct config_group *gadgets_make(
1581 		struct config_group *group,
1582 		const char *name)
1583 {
1584 	struct gadget_info *gi;
1585 
1586 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1587 	if (!gi)
1588 		return ERR_PTR(-ENOMEM);
1589 
1590 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1591 
1592 	config_group_init_type_name(&gi->functions_group, "functions",
1593 			&functions_type);
1594 	configfs_add_default_group(&gi->functions_group, &gi->group);
1595 
1596 	config_group_init_type_name(&gi->configs_group, "configs",
1597 			&config_desc_type);
1598 	configfs_add_default_group(&gi->configs_group, &gi->group);
1599 
1600 	config_group_init_type_name(&gi->strings_group, "strings",
1601 			&gadget_strings_strings_type);
1602 	configfs_add_default_group(&gi->strings_group, &gi->group);
1603 
1604 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1605 			&os_desc_type);
1606 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1607 
1608 	gi->composite.bind = configfs_do_nothing;
1609 	gi->composite.unbind = configfs_do_nothing;
1610 	gi->composite.suspend = NULL;
1611 	gi->composite.resume = NULL;
1612 	gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
1613 
1614 	spin_lock_init(&gi->spinlock);
1615 	mutex_init(&gi->lock);
1616 	INIT_LIST_HEAD(&gi->string_list);
1617 	INIT_LIST_HEAD(&gi->available_func);
1618 
1619 	composite_init_dev(&gi->cdev);
1620 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1621 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1622 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1623 
1624 	gi->composite.gadget_driver = configfs_driver_template;
1625 
1626 	gi->composite.gadget_driver.driver.name = kasprintf(GFP_KERNEL,
1627 							    "configfs-gadget.%s", name);
1628 	if (!gi->composite.gadget_driver.driver.name)
1629 		goto err;
1630 
1631 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1632 	gi->composite.name = gi->composite.gadget_driver.function;
1633 
1634 	if (!gi->composite.gadget_driver.function)
1635 		goto out_free_driver_name;
1636 
1637 	return &gi->group;
1638 
1639 out_free_driver_name:
1640 	kfree(gi->composite.gadget_driver.driver.name);
1641 err:
1642 	kfree(gi);
1643 	return ERR_PTR(-ENOMEM);
1644 }
1645 
1646 static void gadgets_drop(struct config_group *group, struct config_item *item)
1647 {
1648 	config_item_put(item);
1649 }
1650 
1651 static struct configfs_group_operations gadgets_ops = {
1652 	.make_group     = &gadgets_make,
1653 	.drop_item      = &gadgets_drop,
1654 };
1655 
1656 static const struct config_item_type gadgets_type = {
1657 	.ct_group_ops   = &gadgets_ops,
1658 	.ct_owner       = THIS_MODULE,
1659 };
1660 
1661 static struct configfs_subsystem gadget_subsys = {
1662 	.su_group = {
1663 		.cg_item = {
1664 			.ci_namebuf = "usb_gadget",
1665 			.ci_type = &gadgets_type,
1666 		},
1667 	},
1668 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1669 };
1670 
1671 void unregister_gadget_item(struct config_item *item)
1672 {
1673 	struct gadget_info *gi = to_gadget_info(item);
1674 
1675 	mutex_lock(&gi->lock);
1676 	unregister_gadget(gi);
1677 	mutex_unlock(&gi->lock);
1678 }
1679 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1680 
1681 static int __init gadget_cfs_init(void)
1682 {
1683 	int ret;
1684 
1685 	config_group_init(&gadget_subsys.su_group);
1686 
1687 	ret = configfs_register_subsystem(&gadget_subsys);
1688 	return ret;
1689 }
1690 module_init(gadget_cfs_init);
1691 
1692 static void __exit gadget_cfs_exit(void)
1693 {
1694 	configfs_unregister_subsystem(&gadget_subsys);
1695 }
1696 module_exit(gadget_cfs_exit);
1697