xref: /openbmc/linux/drivers/usb/gadget/configfs.c (revision dc6a81c3) 
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/configfs.h>
3 #include <linux/module.h>
4 #include <linux/slab.h>
5 #include <linux/device.h>
6 #include <linux/nls.h>
7 #include <linux/usb/composite.h>
8 #include <linux/usb/gadget_configfs.h>
9 #include "configfs.h"
10 #include "u_f.h"
11 #include "u_os_desc.h"
12 
13 int check_user_usb_string(const char *name,
14 		struct usb_gadget_strings *stringtab_dev)
15 {
16 	unsigned primary_lang;
17 	unsigned sub_lang;
18 	u16 num;
19 	int ret;
20 
21 	ret = kstrtou16(name, 0, &num);
22 	if (ret)
23 		return ret;
24 
25 	primary_lang = num & 0x3ff;
26 	sub_lang = num >> 10;
27 
28 	/* simple sanity check for valid langid */
29 	switch (primary_lang) {
30 	case 0:
31 	case 0x62 ... 0xfe:
32 	case 0x100 ... 0x3ff:
33 		return -EINVAL;
34 	}
35 	if (!sub_lang)
36 		return -EINVAL;
37 
38 	stringtab_dev->language = num;
39 	return 0;
40 }
41 
42 #define MAX_NAME_LEN	40
43 #define MAX_USB_STRING_LANGS 2
44 
45 static const struct usb_descriptor_header *otg_desc[2];
46 
47 struct gadget_info {
48 	struct config_group group;
49 	struct config_group functions_group;
50 	struct config_group configs_group;
51 	struct config_group strings_group;
52 	struct config_group os_desc_group;
53 
54 	struct mutex lock;
55 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
56 	struct list_head string_list;
57 	struct list_head available_func;
58 
59 	struct usb_composite_driver composite;
60 	struct usb_composite_dev cdev;
61 	bool use_os_desc;
62 	char b_vendor_code;
63 	char qw_sign[OS_STRING_QW_SIGN_LEN];
64 	spinlock_t spinlock;
65 	bool unbind;
66 };
67 
68 static inline struct gadget_info *to_gadget_info(struct config_item *item)
69 {
70 	 return container_of(to_config_group(item), struct gadget_info, group);
71 }
72 
73 struct config_usb_cfg {
74 	struct config_group group;
75 	struct config_group strings_group;
76 	struct list_head string_list;
77 	struct usb_configuration c;
78 	struct list_head func_list;
79 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
80 };
81 
82 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
83 {
84 	return container_of(to_config_group(item), struct config_usb_cfg,
85 			group);
86 }
87 
88 struct gadget_strings {
89 	struct usb_gadget_strings stringtab_dev;
90 	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
91 	char *manufacturer;
92 	char *product;
93 	char *serialnumber;
94 
95 	struct config_group group;
96 	struct list_head list;
97 };
98 
99 struct os_desc {
100 	struct config_group group;
101 };
102 
103 struct gadget_config_name {
104 	struct usb_gadget_strings stringtab_dev;
105 	struct usb_string strings;
106 	char *configuration;
107 
108 	struct config_group group;
109 	struct list_head list;
110 };
111 
112 static int usb_string_copy(const char *s, char **s_copy)
113 {
114 	int ret;
115 	char *str;
116 	char *copy = *s_copy;
117 	ret = strlen(s);
118 	if (ret > 126)
119 		return -EOVERFLOW;
120 
121 	str = kstrdup(s, GFP_KERNEL);
122 	if (!str)
123 		return -ENOMEM;
124 	if (str[ret - 1] == '\n')
125 		str[ret - 1] = '\0';
126 	kfree(copy);
127 	*s_copy = str;
128 	return 0;
129 }
130 
131 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
132 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
133 			char *page)	\
134 {	\
135 	return sprintf(page, "0x%02x\n", \
136 		to_gadget_info(item)->cdev.desc.__name); \
137 }
138 
139 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
140 static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
141 			char *page)	\
142 {	\
143 	return sprintf(page, "0x%04x\n", \
144 		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
145 }
146 
147 
148 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
149 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
150 		const char *page, size_t len)		\
151 {							\
152 	u8 val;						\
153 	int ret;					\
154 	ret = kstrtou8(page, 0, &val);			\
155 	if (ret)					\
156 		return ret;				\
157 	to_gadget_info(item)->cdev.desc._name = val;	\
158 	return len;					\
159 }
160 
161 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
162 static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
163 		const char *page, size_t len)		\
164 {							\
165 	u16 val;					\
166 	int ret;					\
167 	ret = kstrtou16(page, 0, &val);			\
168 	if (ret)					\
169 		return ret;				\
170 	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
171 	return len;					\
172 }
173 
174 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
175 	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
176 	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
177 
178 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
179 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
180 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
181 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
182 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
183 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
184 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
185 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
186 
187 static ssize_t is_valid_bcd(u16 bcd_val)
188 {
189 	if ((bcd_val & 0xf) > 9)
190 		return -EINVAL;
191 	if (((bcd_val >> 4) & 0xf) > 9)
192 		return -EINVAL;
193 	if (((bcd_val >> 8) & 0xf) > 9)
194 		return -EINVAL;
195 	if (((bcd_val >> 12) & 0xf) > 9)
196 		return -EINVAL;
197 	return 0;
198 }
199 
200 static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
201 		const char *page, size_t len)
202 {
203 	u16 bcdDevice;
204 	int ret;
205 
206 	ret = kstrtou16(page, 0, &bcdDevice);
207 	if (ret)
208 		return ret;
209 	ret = is_valid_bcd(bcdDevice);
210 	if (ret)
211 		return ret;
212 
213 	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
214 	return len;
215 }
216 
217 static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
218 		const char *page, size_t len)
219 {
220 	u16 bcdUSB;
221 	int ret;
222 
223 	ret = kstrtou16(page, 0, &bcdUSB);
224 	if (ret)
225 		return ret;
226 	ret = is_valid_bcd(bcdUSB);
227 	if (ret)
228 		return ret;
229 
230 	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
231 	return len;
232 }
233 
234 static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
235 {
236 	char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;
237 
238 	return sprintf(page, "%s\n", udc_name ?: "");
239 }
240 
241 static int unregister_gadget(struct gadget_info *gi)
242 {
243 	int ret;
244 
245 	if (!gi->composite.gadget_driver.udc_name)
246 		return -ENODEV;
247 
248 	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
249 	if (ret)
250 		return ret;
251 	kfree(gi->composite.gadget_driver.udc_name);
252 	gi->composite.gadget_driver.udc_name = NULL;
253 	return 0;
254 }
255 
256 static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
257 		const char *page, size_t len)
258 {
259 	struct gadget_info *gi = to_gadget_info(item);
260 	char *name;
261 	int ret;
262 
263 	name = kstrdup(page, GFP_KERNEL);
264 	if (!name)
265 		return -ENOMEM;
266 	if (name[len - 1] == '\n')
267 		name[len - 1] = '\0';
268 
269 	mutex_lock(&gi->lock);
270 
271 	if (!strlen(name)) {
272 		ret = unregister_gadget(gi);
273 		if (ret)
274 			goto err;
275 		kfree(name);
276 	} else {
277 		if (gi->composite.gadget_driver.udc_name) {
278 			ret = -EBUSY;
279 			goto err;
280 		}
281 		gi->composite.gadget_driver.udc_name = name;
282 		ret = usb_gadget_probe_driver(&gi->composite.gadget_driver);
283 		if (ret) {
284 			gi->composite.gadget_driver.udc_name = NULL;
285 			goto err;
286 		}
287 	}
288 	mutex_unlock(&gi->lock);
289 	return len;
290 err:
291 	kfree(name);
292 	mutex_unlock(&gi->lock);
293 	return ret;
294 }
295 
296 static ssize_t gadget_dev_desc_max_speed_show(struct config_item *item,
297 					      char *page)
298 {
299 	enum usb_device_speed speed = to_gadget_info(item)->composite.max_speed;
300 
301 	return sprintf(page, "%s\n", usb_speed_string(speed));
302 }
303 
304 static ssize_t gadget_dev_desc_max_speed_store(struct config_item *item,
305 					       const char *page, size_t len)
306 {
307 	struct gadget_info *gi = to_gadget_info(item);
308 
309 	mutex_lock(&gi->lock);
310 
311 	/* Prevent changing of max_speed after the driver is binded */
312 	if (gi->composite.gadget_driver.udc_name)
313 		goto err;
314 
315 	if (strncmp(page, "super-speed-plus", 16) == 0)
316 		gi->composite.max_speed = USB_SPEED_SUPER_PLUS;
317 	else if (strncmp(page, "super-speed", 11) == 0)
318 		gi->composite.max_speed = USB_SPEED_SUPER;
319 	else if (strncmp(page, "high-speed", 10) == 0)
320 		gi->composite.max_speed = USB_SPEED_HIGH;
321 	else if (strncmp(page, "full-speed", 10) == 0)
322 		gi->composite.max_speed = USB_SPEED_FULL;
323 	else if (strncmp(page, "low-speed", 9) == 0)
324 		gi->composite.max_speed = USB_SPEED_LOW;
325 	else
326 		goto err;
327 
328 	gi->composite.gadget_driver.max_speed = gi->composite.max_speed;
329 
330 	mutex_unlock(&gi->lock);
331 	return len;
332 err:
333 	mutex_unlock(&gi->lock);
334 	return -EINVAL;
335 }
336 
337 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
338 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
339 CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
340 CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
341 CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
342 CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
343 CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
344 CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
345 CONFIGFS_ATTR(gadget_dev_desc_, UDC);
346 CONFIGFS_ATTR(gadget_dev_desc_, max_speed);
347 
348 static struct configfs_attribute *gadget_root_attrs[] = {
349 	&gadget_dev_desc_attr_bDeviceClass,
350 	&gadget_dev_desc_attr_bDeviceSubClass,
351 	&gadget_dev_desc_attr_bDeviceProtocol,
352 	&gadget_dev_desc_attr_bMaxPacketSize0,
353 	&gadget_dev_desc_attr_idVendor,
354 	&gadget_dev_desc_attr_idProduct,
355 	&gadget_dev_desc_attr_bcdDevice,
356 	&gadget_dev_desc_attr_bcdUSB,
357 	&gadget_dev_desc_attr_UDC,
358 	&gadget_dev_desc_attr_max_speed,
359 	NULL,
360 };
361 
362 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
363 {
364 	 return container_of(to_config_group(item), struct gadget_strings,
365 			 group);
366 }
367 
368 static inline struct gadget_config_name *to_gadget_config_name(
369 		struct config_item *item)
370 {
371 	 return container_of(to_config_group(item), struct gadget_config_name,
372 			 group);
373 }
374 
375 static inline struct usb_function_instance *to_usb_function_instance(
376 		struct config_item *item)
377 {
378 	 return container_of(to_config_group(item),
379 			 struct usb_function_instance, group);
380 }
381 
382 static void gadget_info_attr_release(struct config_item *item)
383 {
384 	struct gadget_info *gi = to_gadget_info(item);
385 
386 	WARN_ON(!list_empty(&gi->cdev.configs));
387 	WARN_ON(!list_empty(&gi->string_list));
388 	WARN_ON(!list_empty(&gi->available_func));
389 	kfree(gi->composite.gadget_driver.function);
390 	kfree(gi);
391 }
392 
393 static struct configfs_item_operations gadget_root_item_ops = {
394 	.release                = gadget_info_attr_release,
395 };
396 
397 static void gadget_config_attr_release(struct config_item *item)
398 {
399 	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
400 
401 	WARN_ON(!list_empty(&cfg->c.functions));
402 	list_del(&cfg->c.list);
403 	kfree(cfg->c.label);
404 	kfree(cfg);
405 }
406 
407 static int config_usb_cfg_link(
408 	struct config_item *usb_cfg_ci,
409 	struct config_item *usb_func_ci)
410 {
411 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
412 	struct usb_composite_dev *cdev = cfg->c.cdev;
413 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
414 
415 	struct config_group *group = to_config_group(usb_func_ci);
416 	struct usb_function_instance *fi = container_of(group,
417 			struct usb_function_instance, group);
418 	struct usb_function_instance *a_fi;
419 	struct usb_function *f;
420 	int ret;
421 
422 	mutex_lock(&gi->lock);
423 	/*
424 	 * Make sure this function is from within our _this_ gadget and not
425 	 * from another gadget or a random directory.
426 	 * Also a function instance can only be linked once.
427 	 */
428 	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
429 		if (a_fi == fi)
430 			break;
431 	}
432 	if (a_fi != fi) {
433 		ret = -EINVAL;
434 		goto out;
435 	}
436 
437 	list_for_each_entry(f, &cfg->func_list, list) {
438 		if (f->fi == fi) {
439 			ret = -EEXIST;
440 			goto out;
441 		}
442 	}
443 
444 	f = usb_get_function(fi);
445 	if (IS_ERR(f)) {
446 		ret = PTR_ERR(f);
447 		goto out;
448 	}
449 
450 	/* stash the function until we bind it to the gadget */
451 	list_add_tail(&f->list, &cfg->func_list);
452 	ret = 0;
453 out:
454 	mutex_unlock(&gi->lock);
455 	return ret;
456 }
457 
458 static void config_usb_cfg_unlink(
459 	struct config_item *usb_cfg_ci,
460 	struct config_item *usb_func_ci)
461 {
462 	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
463 	struct usb_composite_dev *cdev = cfg->c.cdev;
464 	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
465 
466 	struct config_group *group = to_config_group(usb_func_ci);
467 	struct usb_function_instance *fi = container_of(group,
468 			struct usb_function_instance, group);
469 	struct usb_function *f;
470 
471 	/*
472 	 * ideally I would like to forbid to unlink functions while a gadget is
473 	 * bound to an UDC. Since this isn't possible at the moment, we simply
474 	 * force an unbind, the function is available here and then we can
475 	 * remove the function.
476 	 */
477 	mutex_lock(&gi->lock);
478 	if (gi->composite.gadget_driver.udc_name)
479 		unregister_gadget(gi);
480 	WARN_ON(gi->composite.gadget_driver.udc_name);
481 
482 	list_for_each_entry(f, &cfg->func_list, list) {
483 		if (f->fi == fi) {
484 			list_del(&f->list);
485 			usb_put_function(f);
486 			mutex_unlock(&gi->lock);
487 			return;
488 		}
489 	}
490 	mutex_unlock(&gi->lock);
491 	WARN(1, "Unable to locate function to unbind\n");
492 }
493 
494 static struct configfs_item_operations gadget_config_item_ops = {
495 	.release                = gadget_config_attr_release,
496 	.allow_link             = config_usb_cfg_link,
497 	.drop_link              = config_usb_cfg_unlink,
498 };
499 
500 
501 static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
502 		char *page)
503 {
504 	return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
505 }
506 
507 static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
508 		const char *page, size_t len)
509 {
510 	u16 val;
511 	int ret;
512 	ret = kstrtou16(page, 0, &val);
513 	if (ret)
514 		return ret;
515 	if (DIV_ROUND_UP(val, 8) > 0xff)
516 		return -ERANGE;
517 	to_config_usb_cfg(item)->c.MaxPower = val;
518 	return len;
519 }
520 
521 static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
522 		char *page)
523 {
524 	return sprintf(page, "0x%02x\n",
525 		to_config_usb_cfg(item)->c.bmAttributes);
526 }
527 
528 static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
529 		const char *page, size_t len)
530 {
531 	u8 val;
532 	int ret;
533 	ret = kstrtou8(page, 0, &val);
534 	if (ret)
535 		return ret;
536 	if (!(val & USB_CONFIG_ATT_ONE))
537 		return -EINVAL;
538 	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
539 				USB_CONFIG_ATT_WAKEUP))
540 		return -EINVAL;
541 	to_config_usb_cfg(item)->c.bmAttributes = val;
542 	return len;
543 }
544 
545 CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
546 CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
547 
548 static struct configfs_attribute *gadget_config_attrs[] = {
549 	&gadget_config_desc_attr_MaxPower,
550 	&gadget_config_desc_attr_bmAttributes,
551 	NULL,
552 };
553 
554 static const struct config_item_type gadget_config_type = {
555 	.ct_item_ops	= &gadget_config_item_ops,
556 	.ct_attrs	= gadget_config_attrs,
557 	.ct_owner	= THIS_MODULE,
558 };
559 
560 static const struct config_item_type gadget_root_type = {
561 	.ct_item_ops	= &gadget_root_item_ops,
562 	.ct_attrs	= gadget_root_attrs,
563 	.ct_owner	= THIS_MODULE,
564 };
565 
566 static void composite_init_dev(struct usb_composite_dev *cdev)
567 {
568 	spin_lock_init(&cdev->lock);
569 	INIT_LIST_HEAD(&cdev->configs);
570 	INIT_LIST_HEAD(&cdev->gstrings);
571 }
572 
573 static struct config_group *function_make(
574 		struct config_group *group,
575 		const char *name)
576 {
577 	struct gadget_info *gi;
578 	struct usb_function_instance *fi;
579 	char buf[MAX_NAME_LEN];
580 	char *func_name;
581 	char *instance_name;
582 	int ret;
583 
584 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
585 	if (ret >= MAX_NAME_LEN)
586 		return ERR_PTR(-ENAMETOOLONG);
587 
588 	func_name = buf;
589 	instance_name = strchr(func_name, '.');
590 	if (!instance_name) {
591 		pr_err("Unable to locate . in FUNC.INSTANCE\n");
592 		return ERR_PTR(-EINVAL);
593 	}
594 	*instance_name = '\0';
595 	instance_name++;
596 
597 	fi = usb_get_function_instance(func_name);
598 	if (IS_ERR(fi))
599 		return ERR_CAST(fi);
600 
601 	ret = config_item_set_name(&fi->group.cg_item, "%s", name);
602 	if (ret) {
603 		usb_put_function_instance(fi);
604 		return ERR_PTR(ret);
605 	}
606 	if (fi->set_inst_name) {
607 		ret = fi->set_inst_name(fi, instance_name);
608 		if (ret) {
609 			usb_put_function_instance(fi);
610 			return ERR_PTR(ret);
611 		}
612 	}
613 
614 	gi = container_of(group, struct gadget_info, functions_group);
615 
616 	mutex_lock(&gi->lock);
617 	list_add_tail(&fi->cfs_list, &gi->available_func);
618 	mutex_unlock(&gi->lock);
619 	return &fi->group;
620 }
621 
622 static void function_drop(
623 		struct config_group *group,
624 		struct config_item *item)
625 {
626 	struct usb_function_instance *fi = to_usb_function_instance(item);
627 	struct gadget_info *gi;
628 
629 	gi = container_of(group, struct gadget_info, functions_group);
630 
631 	mutex_lock(&gi->lock);
632 	list_del(&fi->cfs_list);
633 	mutex_unlock(&gi->lock);
634 	config_item_put(item);
635 }
636 
637 static struct configfs_group_operations functions_ops = {
638 	.make_group     = &function_make,
639 	.drop_item      = &function_drop,
640 };
641 
642 static const struct config_item_type functions_type = {
643 	.ct_group_ops   = &functions_ops,
644 	.ct_owner       = THIS_MODULE,
645 };
646 
647 GS_STRINGS_RW(gadget_config_name, configuration);
648 
649 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
650 	&gadget_config_name_attr_configuration,
651 	NULL,
652 };
653 
654 static void gadget_config_name_attr_release(struct config_item *item)
655 {
656 	struct gadget_config_name *cn = to_gadget_config_name(item);
657 
658 	kfree(cn->configuration);
659 
660 	list_del(&cn->list);
661 	kfree(cn);
662 }
663 
664 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
665 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
666 
667 static struct config_group *config_desc_make(
668 		struct config_group *group,
669 		const char *name)
670 {
671 	struct gadget_info *gi;
672 	struct config_usb_cfg *cfg;
673 	char buf[MAX_NAME_LEN];
674 	char *num_str;
675 	u8 num;
676 	int ret;
677 
678 	gi = container_of(group, struct gadget_info, configs_group);
679 	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
680 	if (ret >= MAX_NAME_LEN)
681 		return ERR_PTR(-ENAMETOOLONG);
682 
683 	num_str = strchr(buf, '.');
684 	if (!num_str) {
685 		pr_err("Unable to locate . in name.bConfigurationValue\n");
686 		return ERR_PTR(-EINVAL);
687 	}
688 
689 	*num_str = '\0';
690 	num_str++;
691 
692 	if (!strlen(buf))
693 		return ERR_PTR(-EINVAL);
694 
695 	ret = kstrtou8(num_str, 0, &num);
696 	if (ret)
697 		return ERR_PTR(ret);
698 
699 	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
700 	if (!cfg)
701 		return ERR_PTR(-ENOMEM);
702 	cfg->c.label = kstrdup(buf, GFP_KERNEL);
703 	if (!cfg->c.label) {
704 		ret = -ENOMEM;
705 		goto err;
706 	}
707 	cfg->c.bConfigurationValue = num;
708 	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
709 	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
710 	INIT_LIST_HEAD(&cfg->string_list);
711 	INIT_LIST_HEAD(&cfg->func_list);
712 
713 	config_group_init_type_name(&cfg->group, name,
714 				&gadget_config_type);
715 
716 	config_group_init_type_name(&cfg->strings_group, "strings",
717 			&gadget_config_name_strings_type);
718 	configfs_add_default_group(&cfg->strings_group, &cfg->group);
719 
720 	ret = usb_add_config_only(&gi->cdev, &cfg->c);
721 	if (ret)
722 		goto err;
723 
724 	return &cfg->group;
725 err:
726 	kfree(cfg->c.label);
727 	kfree(cfg);
728 	return ERR_PTR(ret);
729 }
730 
731 static void config_desc_drop(
732 		struct config_group *group,
733 		struct config_item *item)
734 {
735 	config_item_put(item);
736 }
737 
738 static struct configfs_group_operations config_desc_ops = {
739 	.make_group     = &config_desc_make,
740 	.drop_item      = &config_desc_drop,
741 };
742 
743 static const struct config_item_type config_desc_type = {
744 	.ct_group_ops   = &config_desc_ops,
745 	.ct_owner       = THIS_MODULE,
746 };
747 
748 GS_STRINGS_RW(gadget_strings, manufacturer);
749 GS_STRINGS_RW(gadget_strings, product);
750 GS_STRINGS_RW(gadget_strings, serialnumber);
751 
752 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
753 	&gadget_strings_attr_manufacturer,
754 	&gadget_strings_attr_product,
755 	&gadget_strings_attr_serialnumber,
756 	NULL,
757 };
758 
759 static void gadget_strings_attr_release(struct config_item *item)
760 {
761 	struct gadget_strings *gs = to_gadget_strings(item);
762 
763 	kfree(gs->manufacturer);
764 	kfree(gs->product);
765 	kfree(gs->serialnumber);
766 
767 	list_del(&gs->list);
768 	kfree(gs);
769 }
770 
771 USB_CONFIG_STRING_RW_OPS(gadget_strings);
772 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
773 
774 static inline struct os_desc *to_os_desc(struct config_item *item)
775 {
776 	return container_of(to_config_group(item), struct os_desc, group);
777 }
778 
779 static inline struct gadget_info *os_desc_item_to_gadget_info(
780 		struct config_item *item)
781 {
782 	return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
783 }
784 
785 static ssize_t os_desc_use_show(struct config_item *item, char *page)
786 {
787 	return sprintf(page, "%d\n",
788 			os_desc_item_to_gadget_info(item)->use_os_desc);
789 }
790 
791 static ssize_t os_desc_use_store(struct config_item *item, const char *page,
792 				 size_t len)
793 {
794 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
795 	int ret;
796 	bool use;
797 
798 	mutex_lock(&gi->lock);
799 	ret = strtobool(page, &use);
800 	if (!ret) {
801 		gi->use_os_desc = use;
802 		ret = len;
803 	}
804 	mutex_unlock(&gi->lock);
805 
806 	return ret;
807 }
808 
809 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
810 {
811 	return sprintf(page, "0x%02x\n",
812 			os_desc_item_to_gadget_info(item)->b_vendor_code);
813 }
814 
815 static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
816 					   const char *page, size_t len)
817 {
818 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
819 	int ret;
820 	u8 b_vendor_code;
821 
822 	mutex_lock(&gi->lock);
823 	ret = kstrtou8(page, 0, &b_vendor_code);
824 	if (!ret) {
825 		gi->b_vendor_code = b_vendor_code;
826 		ret = len;
827 	}
828 	mutex_unlock(&gi->lock);
829 
830 	return ret;
831 }
832 
833 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
834 {
835 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
836 	int res;
837 
838 	res = utf16s_to_utf8s((wchar_t *) gi->qw_sign, OS_STRING_QW_SIGN_LEN,
839 			      UTF16_LITTLE_ENDIAN, page, PAGE_SIZE - 1);
840 	page[res++] = '\n';
841 
842 	return res;
843 }
844 
845 static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
846 				     size_t len)
847 {
848 	struct gadget_info *gi = os_desc_item_to_gadget_info(item);
849 	int res, l;
850 
851 	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
852 	if (page[l - 1] == '\n')
853 		--l;
854 
855 	mutex_lock(&gi->lock);
856 	res = utf8s_to_utf16s(page, l,
857 			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
858 			      OS_STRING_QW_SIGN_LEN);
859 	if (res > 0)
860 		res = len;
861 	mutex_unlock(&gi->lock);
862 
863 	return res;
864 }
865 
866 CONFIGFS_ATTR(os_desc_, use);
867 CONFIGFS_ATTR(os_desc_, b_vendor_code);
868 CONFIGFS_ATTR(os_desc_, qw_sign);
869 
870 static struct configfs_attribute *os_desc_attrs[] = {
871 	&os_desc_attr_use,
872 	&os_desc_attr_b_vendor_code,
873 	&os_desc_attr_qw_sign,
874 	NULL,
875 };
876 
877 static void os_desc_attr_release(struct config_item *item)
878 {
879 	struct os_desc *os_desc = to_os_desc(item);
880 	kfree(os_desc);
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 = container_of(to_config_group(os_desc_ci),
887 					struct gadget_info, os_desc_group);
888 	struct usb_composite_dev *cdev = &gi->cdev;
889 	struct config_usb_cfg *c_target =
890 		container_of(to_config_group(usb_cfg_ci),
891 			     struct config_usb_cfg, group);
892 	struct usb_configuration *c;
893 	int ret;
894 
895 	mutex_lock(&gi->lock);
896 	list_for_each_entry(c, &cdev->configs, list) {
897 		if (c == &c_target->c)
898 			break;
899 	}
900 	if (c != &c_target->c) {
901 		ret = -EINVAL;
902 		goto out;
903 	}
904 
905 	if (cdev->os_desc_config) {
906 		ret = -EBUSY;
907 		goto out;
908 	}
909 
910 	cdev->os_desc_config = &c_target->c;
911 	ret = 0;
912 
913 out:
914 	mutex_unlock(&gi->lock);
915 	return ret;
916 }
917 
918 static void os_desc_unlink(struct config_item *os_desc_ci,
919 			  struct config_item *usb_cfg_ci)
920 {
921 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
922 					struct gadget_info, os_desc_group);
923 	struct usb_composite_dev *cdev = &gi->cdev;
924 
925 	mutex_lock(&gi->lock);
926 	if (gi->composite.gadget_driver.udc_name)
927 		unregister_gadget(gi);
928 	cdev->os_desc_config = NULL;
929 	WARN_ON(gi->composite.gadget_driver.udc_name);
930 	mutex_unlock(&gi->lock);
931 }
932 
933 static struct configfs_item_operations os_desc_ops = {
934 	.release                = os_desc_attr_release,
935 	.allow_link		= os_desc_link,
936 	.drop_link		= os_desc_unlink,
937 };
938 
939 static struct config_item_type os_desc_type = {
940 	.ct_item_ops	= &os_desc_ops,
941 	.ct_attrs	= os_desc_attrs,
942 	.ct_owner	= THIS_MODULE,
943 };
944 
945 static inline struct usb_os_desc_ext_prop
946 *to_usb_os_desc_ext_prop(struct config_item *item)
947 {
948 	return container_of(item, struct usb_os_desc_ext_prop, item);
949 }
950 
951 static ssize_t ext_prop_type_show(struct config_item *item, char *page)
952 {
953 	return sprintf(page, "%d\n", to_usb_os_desc_ext_prop(item)->type);
954 }
955 
956 static ssize_t ext_prop_type_store(struct config_item *item,
957 				   const char *page, size_t len)
958 {
959 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
960 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
961 	u8 type;
962 	int ret;
963 
964 	if (desc->opts_mutex)
965 		mutex_lock(desc->opts_mutex);
966 	ret = kstrtou8(page, 0, &type);
967 	if (ret)
968 		goto end;
969 	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
970 		ret = -EINVAL;
971 		goto end;
972 	}
973 
974 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
975 	    ext_prop->type == USB_EXT_PROP_LE32 ||
976 	    ext_prop->type == USB_EXT_PROP_BE32) &&
977 	    (type == USB_EXT_PROP_UNICODE ||
978 	    type == USB_EXT_PROP_UNICODE_ENV ||
979 	    type == USB_EXT_PROP_UNICODE_LINK))
980 		ext_prop->data_len <<= 1;
981 	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
982 		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
983 		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
984 		   (type == USB_EXT_PROP_BINARY ||
985 		   type == USB_EXT_PROP_LE32 ||
986 		   type == USB_EXT_PROP_BE32))
987 		ext_prop->data_len >>= 1;
988 	ext_prop->type = type;
989 	ret = len;
990 
991 end:
992 	if (desc->opts_mutex)
993 		mutex_unlock(desc->opts_mutex);
994 	return ret;
995 }
996 
997 static ssize_t ext_prop_data_show(struct config_item *item, char *page)
998 {
999 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1000 	int len = ext_prop->data_len;
1001 
1002 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1003 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1004 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1005 		len >>= 1;
1006 	memcpy(page, ext_prop->data, len);
1007 
1008 	return len;
1009 }
1010 
1011 static ssize_t ext_prop_data_store(struct config_item *item,
1012 				   const char *page, size_t len)
1013 {
1014 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1015 	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1016 	char *new_data;
1017 	size_t ret_len = len;
1018 
1019 	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1020 		--len;
1021 	new_data = kmemdup(page, len, GFP_KERNEL);
1022 	if (!new_data)
1023 		return -ENOMEM;
1024 
1025 	if (desc->opts_mutex)
1026 		mutex_lock(desc->opts_mutex);
1027 	kfree(ext_prop->data);
1028 	ext_prop->data = new_data;
1029 	desc->ext_prop_len -= ext_prop->data_len;
1030 	ext_prop->data_len = len;
1031 	desc->ext_prop_len += ext_prop->data_len;
1032 	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1033 	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1034 	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1035 		desc->ext_prop_len -= ext_prop->data_len;
1036 		ext_prop->data_len <<= 1;
1037 		ext_prop->data_len += 2;
1038 		desc->ext_prop_len += ext_prop->data_len;
1039 	}
1040 	if (desc->opts_mutex)
1041 		mutex_unlock(desc->opts_mutex);
1042 	return ret_len;
1043 }
1044 
1045 CONFIGFS_ATTR(ext_prop_, type);
1046 CONFIGFS_ATTR(ext_prop_, data);
1047 
1048 static struct configfs_attribute *ext_prop_attrs[] = {
1049 	&ext_prop_attr_type,
1050 	&ext_prop_attr_data,
1051 	NULL,
1052 };
1053 
1054 static void usb_os_desc_ext_prop_release(struct config_item *item)
1055 {
1056 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1057 
1058 	kfree(ext_prop); /* frees a whole chunk */
1059 }
1060 
1061 static struct configfs_item_operations ext_prop_ops = {
1062 	.release		= usb_os_desc_ext_prop_release,
1063 };
1064 
1065 static struct config_item *ext_prop_make(
1066 		struct config_group *group,
1067 		const char *name)
1068 {
1069 	struct usb_os_desc_ext_prop *ext_prop;
1070 	struct config_item_type *ext_prop_type;
1071 	struct usb_os_desc *desc;
1072 	char *vlabuf;
1073 
1074 	vla_group(data_chunk);
1075 	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1076 	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1077 
1078 	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1079 	if (!vlabuf)
1080 		return ERR_PTR(-ENOMEM);
1081 
1082 	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1083 	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1084 
1085 	desc = container_of(group, struct usb_os_desc, group);
1086 	ext_prop_type->ct_item_ops = &ext_prop_ops;
1087 	ext_prop_type->ct_attrs = ext_prop_attrs;
1088 	ext_prop_type->ct_owner = desc->owner;
1089 
1090 	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1091 
1092 	ext_prop->name = kstrdup(name, GFP_KERNEL);
1093 	if (!ext_prop->name) {
1094 		kfree(vlabuf);
1095 		return ERR_PTR(-ENOMEM);
1096 	}
1097 	desc->ext_prop_len += 14;
1098 	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1099 	if (desc->opts_mutex)
1100 		mutex_lock(desc->opts_mutex);
1101 	desc->ext_prop_len += ext_prop->name_len;
1102 	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1103 	++desc->ext_prop_count;
1104 	if (desc->opts_mutex)
1105 		mutex_unlock(desc->opts_mutex);
1106 
1107 	return &ext_prop->item;
1108 }
1109 
1110 static void ext_prop_drop(struct config_group *group, struct config_item *item)
1111 {
1112 	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1113 	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1114 
1115 	if (desc->opts_mutex)
1116 		mutex_lock(desc->opts_mutex);
1117 	list_del(&ext_prop->entry);
1118 	--desc->ext_prop_count;
1119 	kfree(ext_prop->name);
1120 	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1121 	if (desc->opts_mutex)
1122 		mutex_unlock(desc->opts_mutex);
1123 	config_item_put(item);
1124 }
1125 
1126 static struct configfs_group_operations interf_grp_ops = {
1127 	.make_item	= &ext_prop_make,
1128 	.drop_item	= &ext_prop_drop,
1129 };
1130 
1131 static ssize_t interf_grp_compatible_id_show(struct config_item *item,
1132 					     char *page)
1133 {
1134 	memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
1135 	return 8;
1136 }
1137 
1138 static ssize_t interf_grp_compatible_id_store(struct config_item *item,
1139 					      const char *page, size_t len)
1140 {
1141 	struct usb_os_desc *desc = to_usb_os_desc(item);
1142 	int l;
1143 
1144 	l = min_t(int, 8, len);
1145 	if (page[l - 1] == '\n')
1146 		--l;
1147 	if (desc->opts_mutex)
1148 		mutex_lock(desc->opts_mutex);
1149 	memcpy(desc->ext_compat_id, page, l);
1150 
1151 	if (desc->opts_mutex)
1152 		mutex_unlock(desc->opts_mutex);
1153 
1154 	return len;
1155 }
1156 
1157 static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
1158 						 char *page)
1159 {
1160 	memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
1161 	return 8;
1162 }
1163 
1164 static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
1165 						  const char *page, size_t len)
1166 {
1167 	struct usb_os_desc *desc = to_usb_os_desc(item);
1168 	int l;
1169 
1170 	l = min_t(int, 8, len);
1171 	if (page[l - 1] == '\n')
1172 		--l;
1173 	if (desc->opts_mutex)
1174 		mutex_lock(desc->opts_mutex);
1175 	memcpy(desc->ext_compat_id + 8, page, l);
1176 
1177 	if (desc->opts_mutex)
1178 		mutex_unlock(desc->opts_mutex);
1179 
1180 	return len;
1181 }
1182 
1183 CONFIGFS_ATTR(interf_grp_, compatible_id);
1184 CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
1185 
1186 static struct configfs_attribute *interf_grp_attrs[] = {
1187 	&interf_grp_attr_compatible_id,
1188 	&interf_grp_attr_sub_compatible_id,
1189 	NULL
1190 };
1191 
1192 struct config_group *usb_os_desc_prepare_interf_dir(
1193 		struct config_group *parent,
1194 		int n_interf,
1195 		struct usb_os_desc **desc,
1196 		char **names,
1197 		struct module *owner)
1198 {
1199 	struct config_group *os_desc_group;
1200 	struct config_item_type *os_desc_type, *interface_type;
1201 
1202 	vla_group(data_chunk);
1203 	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1204 	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1205 	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1206 
1207 	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1208 	if (!vlabuf)
1209 		return ERR_PTR(-ENOMEM);
1210 
1211 	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1212 	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1213 	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1214 
1215 	os_desc_type->ct_owner = owner;
1216 	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1217 	configfs_add_default_group(os_desc_group, parent);
1218 
1219 	interface_type->ct_group_ops = &interf_grp_ops;
1220 	interface_type->ct_attrs = interf_grp_attrs;
1221 	interface_type->ct_owner = owner;
1222 
1223 	while (n_interf--) {
1224 		struct usb_os_desc *d;
1225 
1226 		d = desc[n_interf];
1227 		d->owner = owner;
1228 		config_group_init_type_name(&d->group, "", interface_type);
1229 		config_item_set_name(&d->group.cg_item, "interface.%s",
1230 				     names[n_interf]);
1231 		configfs_add_default_group(&d->group, os_desc_group);
1232 	}
1233 
1234 	return os_desc_group;
1235 }
1236 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1237 
1238 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1239 {
1240 	WARN_ON(1);
1241 	return -EINVAL;
1242 }
1243 
1244 int composite_dev_prepare(struct usb_composite_driver *composite,
1245 		struct usb_composite_dev *dev);
1246 
1247 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1248 				  struct usb_ep *ep0);
1249 
1250 static void purge_configs_funcs(struct gadget_info *gi)
1251 {
1252 	struct usb_configuration	*c;
1253 
1254 	list_for_each_entry(c, &gi->cdev.configs, list) {
1255 		struct usb_function *f, *tmp;
1256 		struct config_usb_cfg *cfg;
1257 
1258 		cfg = container_of(c, struct config_usb_cfg, c);
1259 
1260 		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1261 
1262 			list_move_tail(&f->list, &cfg->func_list);
1263 			if (f->unbind) {
1264 				dev_dbg(&gi->cdev.gadget->dev,
1265 					"unbind function '%s'/%p\n",
1266 					f->name, f);
1267 				f->unbind(c, f);
1268 			}
1269 		}
1270 		c->next_interface_id = 0;
1271 		memset(c->interface, 0, sizeof(c->interface));
1272 		c->superspeed_plus = 0;
1273 		c->superspeed = 0;
1274 		c->highspeed = 0;
1275 		c->fullspeed = 0;
1276 	}
1277 }
1278 
1279 static int configfs_composite_bind(struct usb_gadget *gadget,
1280 		struct usb_gadget_driver *gdriver)
1281 {
1282 	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1283 	struct gadget_info		*gi = container_of(composite,
1284 						struct gadget_info, composite);
1285 	struct usb_composite_dev	*cdev = &gi->cdev;
1286 	struct usb_configuration	*c;
1287 	struct usb_string		*s;
1288 	unsigned			i;
1289 	int				ret;
1290 
1291 	/* the gi->lock is hold by the caller */
1292 	gi->unbind = 0;
1293 	cdev->gadget = gadget;
1294 	set_gadget_data(gadget, cdev);
1295 	ret = composite_dev_prepare(composite, cdev);
1296 	if (ret)
1297 		return ret;
1298 	/* and now the gadget bind */
1299 	ret = -EINVAL;
1300 
1301 	if (list_empty(&gi->cdev.configs)) {
1302 		pr_err("Need at least one configuration in %s.\n",
1303 				gi->composite.name);
1304 		goto err_comp_cleanup;
1305 	}
1306 
1307 
1308 	list_for_each_entry(c, &gi->cdev.configs, list) {
1309 		struct config_usb_cfg *cfg;
1310 
1311 		cfg = container_of(c, struct config_usb_cfg, c);
1312 		if (list_empty(&cfg->func_list)) {
1313 			pr_err("Config %s/%d of %s needs at least one function.\n",
1314 			      c->label, c->bConfigurationValue,
1315 			      gi->composite.name);
1316 			goto err_comp_cleanup;
1317 		}
1318 	}
1319 
1320 	/* init all strings */
1321 	if (!list_empty(&gi->string_list)) {
1322 		struct gadget_strings *gs;
1323 
1324 		i = 0;
1325 		list_for_each_entry(gs, &gi->string_list, list) {
1326 
1327 			gi->gstrings[i] = &gs->stringtab_dev;
1328 			gs->stringtab_dev.strings = gs->strings;
1329 			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1330 				gs->manufacturer;
1331 			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1332 			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1333 			i++;
1334 		}
1335 		gi->gstrings[i] = NULL;
1336 		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1337 				USB_GADGET_FIRST_AVAIL_IDX);
1338 		if (IS_ERR(s)) {
1339 			ret = PTR_ERR(s);
1340 			goto err_comp_cleanup;
1341 		}
1342 
1343 		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1344 		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1345 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1346 	}
1347 
1348 	if (gi->use_os_desc) {
1349 		cdev->use_os_string = true;
1350 		cdev->b_vendor_code = gi->b_vendor_code;
1351 		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1352 	}
1353 
1354 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
1355 		struct usb_descriptor_header *usb_desc;
1356 
1357 		usb_desc = usb_otg_descriptor_alloc(gadget);
1358 		if (!usb_desc) {
1359 			ret = -ENOMEM;
1360 			goto err_comp_cleanup;
1361 		}
1362 		usb_otg_descriptor_init(gadget, usb_desc);
1363 		otg_desc[0] = usb_desc;
1364 		otg_desc[1] = NULL;
1365 	}
1366 
1367 	/* Go through all configs, attach all functions */
1368 	list_for_each_entry(c, &gi->cdev.configs, list) {
1369 		struct config_usb_cfg *cfg;
1370 		struct usb_function *f;
1371 		struct usb_function *tmp;
1372 		struct gadget_config_name *cn;
1373 
1374 		if (gadget_is_otg(gadget))
1375 			c->descriptors = otg_desc;
1376 
1377 		cfg = container_of(c, struct config_usb_cfg, c);
1378 		if (!list_empty(&cfg->string_list)) {
1379 			i = 0;
1380 			list_for_each_entry(cn, &cfg->string_list, list) {
1381 				cfg->gstrings[i] = &cn->stringtab_dev;
1382 				cn->stringtab_dev.strings = &cn->strings;
1383 				cn->strings.s = cn->configuration;
1384 				i++;
1385 			}
1386 			cfg->gstrings[i] = NULL;
1387 			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1388 			if (IS_ERR(s)) {
1389 				ret = PTR_ERR(s);
1390 				goto err_comp_cleanup;
1391 			}
1392 			c->iConfiguration = s[0].id;
1393 		}
1394 
1395 		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1396 			list_del(&f->list);
1397 			ret = usb_add_function(c, f);
1398 			if (ret) {
1399 				list_add(&f->list, &cfg->func_list);
1400 				goto err_purge_funcs;
1401 			}
1402 		}
1403 		usb_ep_autoconfig_reset(cdev->gadget);
1404 	}
1405 	if (cdev->use_os_string) {
1406 		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1407 		if (ret)
1408 			goto err_purge_funcs;
1409 	}
1410 
1411 	usb_ep_autoconfig_reset(cdev->gadget);
1412 	return 0;
1413 
1414 err_purge_funcs:
1415 	purge_configs_funcs(gi);
1416 err_comp_cleanup:
1417 	composite_dev_cleanup(cdev);
1418 	return ret;
1419 }
1420 
1421 static void configfs_composite_unbind(struct usb_gadget *gadget)
1422 {
1423 	struct usb_composite_dev	*cdev;
1424 	struct gadget_info		*gi;
1425 	unsigned long flags;
1426 
1427 	/* the gi->lock is hold by the caller */
1428 
1429 	cdev = get_gadget_data(gadget);
1430 	gi = container_of(cdev, struct gadget_info, cdev);
1431 	spin_lock_irqsave(&gi->spinlock, flags);
1432 	gi->unbind = 1;
1433 	spin_unlock_irqrestore(&gi->spinlock, flags);
1434 
1435 	kfree(otg_desc[0]);
1436 	otg_desc[0] = NULL;
1437 	purge_configs_funcs(gi);
1438 	composite_dev_cleanup(cdev);
1439 	usb_ep_autoconfig_reset(cdev->gadget);
1440 	spin_lock_irqsave(&gi->spinlock, flags);
1441 	cdev->gadget = NULL;
1442 	set_gadget_data(gadget, NULL);
1443 	spin_unlock_irqrestore(&gi->spinlock, flags);
1444 }
1445 
1446 static int configfs_composite_setup(struct usb_gadget *gadget,
1447 		const struct usb_ctrlrequest *ctrl)
1448 {
1449 	struct usb_composite_dev *cdev;
1450 	struct gadget_info *gi;
1451 	unsigned long flags;
1452 	int ret;
1453 
1454 	cdev = get_gadget_data(gadget);
1455 	if (!cdev)
1456 		return 0;
1457 
1458 	gi = container_of(cdev, struct gadget_info, cdev);
1459 	spin_lock_irqsave(&gi->spinlock, flags);
1460 	cdev = get_gadget_data(gadget);
1461 	if (!cdev || gi->unbind) {
1462 		spin_unlock_irqrestore(&gi->spinlock, flags);
1463 		return 0;
1464 	}
1465 
1466 	ret = composite_setup(gadget, ctrl);
1467 	spin_unlock_irqrestore(&gi->spinlock, flags);
1468 	return ret;
1469 }
1470 
1471 static void configfs_composite_disconnect(struct usb_gadget *gadget)
1472 {
1473 	struct usb_composite_dev *cdev;
1474 	struct gadget_info *gi;
1475 	unsigned long flags;
1476 
1477 	cdev = get_gadget_data(gadget);
1478 	if (!cdev)
1479 		return;
1480 
1481 	gi = container_of(cdev, struct gadget_info, cdev);
1482 	spin_lock_irqsave(&gi->spinlock, flags);
1483 	cdev = get_gadget_data(gadget);
1484 	if (!cdev || gi->unbind) {
1485 		spin_unlock_irqrestore(&gi->spinlock, flags);
1486 		return;
1487 	}
1488 
1489 	composite_disconnect(gadget);
1490 	spin_unlock_irqrestore(&gi->spinlock, flags);
1491 }
1492 
1493 static void configfs_composite_suspend(struct usb_gadget *gadget)
1494 {
1495 	struct usb_composite_dev *cdev;
1496 	struct gadget_info *gi;
1497 	unsigned long flags;
1498 
1499 	cdev = get_gadget_data(gadget);
1500 	if (!cdev)
1501 		return;
1502 
1503 	gi = container_of(cdev, struct gadget_info, cdev);
1504 	spin_lock_irqsave(&gi->spinlock, flags);
1505 	cdev = get_gadget_data(gadget);
1506 	if (!cdev || gi->unbind) {
1507 		spin_unlock_irqrestore(&gi->spinlock, flags);
1508 		return;
1509 	}
1510 
1511 	composite_suspend(gadget);
1512 	spin_unlock_irqrestore(&gi->spinlock, flags);
1513 }
1514 
1515 static void configfs_composite_resume(struct usb_gadget *gadget)
1516 {
1517 	struct usb_composite_dev *cdev;
1518 	struct gadget_info *gi;
1519 	unsigned long flags;
1520 
1521 	cdev = get_gadget_data(gadget);
1522 	if (!cdev)
1523 		return;
1524 
1525 	gi = container_of(cdev, struct gadget_info, cdev);
1526 	spin_lock_irqsave(&gi->spinlock, flags);
1527 	cdev = get_gadget_data(gadget);
1528 	if (!cdev || gi->unbind) {
1529 		spin_unlock_irqrestore(&gi->spinlock, flags);
1530 		return;
1531 	}
1532 
1533 	composite_resume(gadget);
1534 	spin_unlock_irqrestore(&gi->spinlock, flags);
1535 }
1536 
1537 static const struct usb_gadget_driver configfs_driver_template = {
1538 	.bind           = configfs_composite_bind,
1539 	.unbind         = configfs_composite_unbind,
1540 
1541 	.setup          = configfs_composite_setup,
1542 	.reset          = configfs_composite_disconnect,
1543 	.disconnect     = configfs_composite_disconnect,
1544 
1545 	.suspend	= configfs_composite_suspend,
1546 	.resume		= configfs_composite_resume,
1547 
1548 	.max_speed	= USB_SPEED_SUPER,
1549 	.driver = {
1550 		.owner          = THIS_MODULE,
1551 		.name		= "configfs-gadget",
1552 	},
1553 	.match_existing_only = 1,
1554 };
1555 
1556 static struct config_group *gadgets_make(
1557 		struct config_group *group,
1558 		const char *name)
1559 {
1560 	struct gadget_info *gi;
1561 
1562 	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1563 	if (!gi)
1564 		return ERR_PTR(-ENOMEM);
1565 
1566 	config_group_init_type_name(&gi->group, name, &gadget_root_type);
1567 
1568 	config_group_init_type_name(&gi->functions_group, "functions",
1569 			&functions_type);
1570 	configfs_add_default_group(&gi->functions_group, &gi->group);
1571 
1572 	config_group_init_type_name(&gi->configs_group, "configs",
1573 			&config_desc_type);
1574 	configfs_add_default_group(&gi->configs_group, &gi->group);
1575 
1576 	config_group_init_type_name(&gi->strings_group, "strings",
1577 			&gadget_strings_strings_type);
1578 	configfs_add_default_group(&gi->strings_group, &gi->group);
1579 
1580 	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1581 			&os_desc_type);
1582 	configfs_add_default_group(&gi->os_desc_group, &gi->group);
1583 
1584 	gi->composite.bind = configfs_do_nothing;
1585 	gi->composite.unbind = configfs_do_nothing;
1586 	gi->composite.suspend = NULL;
1587 	gi->composite.resume = NULL;
1588 	gi->composite.max_speed = USB_SPEED_SUPER;
1589 
1590 	spin_lock_init(&gi->spinlock);
1591 	mutex_init(&gi->lock);
1592 	INIT_LIST_HEAD(&gi->string_list);
1593 	INIT_LIST_HEAD(&gi->available_func);
1594 
1595 	composite_init_dev(&gi->cdev);
1596 	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1597 	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1598 	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1599 
1600 	gi->composite.gadget_driver = configfs_driver_template;
1601 
1602 	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1603 	gi->composite.name = gi->composite.gadget_driver.function;
1604 
1605 	if (!gi->composite.gadget_driver.function)
1606 		goto err;
1607 
1608 	return &gi->group;
1609 err:
1610 	kfree(gi);
1611 	return ERR_PTR(-ENOMEM);
1612 }
1613 
1614 static void gadgets_drop(struct config_group *group, struct config_item *item)
1615 {
1616 	config_item_put(item);
1617 }
1618 
1619 static struct configfs_group_operations gadgets_ops = {
1620 	.make_group     = &gadgets_make,
1621 	.drop_item      = &gadgets_drop,
1622 };
1623 
1624 static const struct config_item_type gadgets_type = {
1625 	.ct_group_ops   = &gadgets_ops,
1626 	.ct_owner       = THIS_MODULE,
1627 };
1628 
1629 static struct configfs_subsystem gadget_subsys = {
1630 	.su_group = {
1631 		.cg_item = {
1632 			.ci_namebuf = "usb_gadget",
1633 			.ci_type = &gadgets_type,
1634 		},
1635 	},
1636 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1637 };
1638 
1639 void unregister_gadget_item(struct config_item *item)
1640 {
1641 	struct gadget_info *gi = to_gadget_info(item);
1642 
1643 	mutex_lock(&gi->lock);
1644 	unregister_gadget(gi);
1645 	mutex_unlock(&gi->lock);
1646 }
1647 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1648 
1649 static int __init gadget_cfs_init(void)
1650 {
1651 	int ret;
1652 
1653 	config_group_init(&gadget_subsys.su_group);
1654 
1655 	ret = configfs_register_subsystem(&gadget_subsys);
1656 	return ret;
1657 }
1658 module_init(gadget_cfs_init);
1659 
1660 static void __exit gadget_cfs_exit(void)
1661 {
1662 	configfs_unregister_subsystem(&gadget_subsys);
1663 }
1664 module_exit(gadget_cfs_exit);
1665