1#include <linux/configfs.h>
2#include <linux/module.h>
3#include <linux/slab.h>
4#include <linux/device.h>
5#include <linux/nls.h>
6#include <linux/usb/composite.h>
7#include <linux/usb/gadget_configfs.h>
8#include "configfs.h"
9#include "u_f.h"
10#include "u_os_desc.h"
11
12int check_user_usb_string(const char *name,
13		struct usb_gadget_strings *stringtab_dev)
14{
15	unsigned primary_lang;
16	unsigned sub_lang;
17	u16 num;
18	int ret;
19
20	ret = kstrtou16(name, 0, &num);
21	if (ret)
22		return ret;
23
24	primary_lang = num & 0x3ff;
25	sub_lang = num >> 10;
26
27	/* simple sanity check for valid langid */
28	switch (primary_lang) {
29	case 0:
30	case 0x62 ... 0xfe:
31	case 0x100 ... 0x3ff:
32		return -EINVAL;
33	}
34	if (!sub_lang)
35		return -EINVAL;
36
37	stringtab_dev->language = num;
38	return 0;
39}
40
41#define MAX_NAME_LEN	40
42#define MAX_USB_STRING_LANGS 2
43
44struct gadget_info {
45	struct config_group group;
46	struct config_group functions_group;
47	struct config_group configs_group;
48	struct config_group strings_group;
49	struct config_group os_desc_group;
50	struct config_group *default_groups[5];
51
52	struct mutex lock;
53	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
54	struct list_head string_list;
55	struct list_head available_func;
56
57	const char *udc_name;
58#ifdef CONFIG_USB_OTG
59	struct usb_otg_descriptor otg;
60#endif
61	struct usb_composite_driver composite;
62	struct usb_composite_dev cdev;
63	bool use_os_desc;
64	char b_vendor_code;
65	char qw_sign[OS_STRING_QW_SIGN_LEN];
66};
67
68struct config_usb_cfg {
69	struct config_group group;
70	struct config_group strings_group;
71	struct config_group *default_groups[2];
72	struct list_head string_list;
73	struct usb_configuration c;
74	struct list_head func_list;
75	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
76};
77
78struct gadget_strings {
79	struct usb_gadget_strings stringtab_dev;
80	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
81	char *manufacturer;
82	char *product;
83	char *serialnumber;
84
85	struct config_group group;
86	struct list_head list;
87};
88
89struct os_desc {
90	struct config_group group;
91};
92
93struct 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
102static int usb_string_copy(const char *s, char **s_copy)
103{
104	int ret;
105	char *str;
106	char *copy = *s_copy;
107	ret = strlen(s);
108	if (ret > 126)
109		return -EOVERFLOW;
110
111	str = kstrdup(s, GFP_KERNEL);
112	if (!str)
113		return -ENOMEM;
114	if (str[ret - 1] == '\n')
115		str[ret - 1] = '\0';
116	kfree(copy);
117	*s_copy = str;
118	return 0;
119}
120
121CONFIGFS_ATTR_STRUCT(gadget_info);
122CONFIGFS_ATTR_STRUCT(config_usb_cfg);
123
124#define GI_DEVICE_DESC_ITEM_ATTR(name)	\
125	static struct gadget_info_attribute gadget_cdev_desc_##name = \
126		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
127				gadget_dev_desc_##name##_show,		\
128				gadget_dev_desc_##name##_store)
129
130#define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
131	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
132			char *page)	\
133{	\
134	return sprintf(page, "0x%02x\n", gi->cdev.desc.__name);	\
135}
136
137#define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
138	static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
139			char *page)	\
140{	\
141	return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
142}
143
144
145#define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
146	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
147		const char *page, size_t len)		\
148{							\
149	u8 val;						\
150	int ret;					\
151	ret = kstrtou8(page, 0, &val);			\
152	if (ret)					\
153		return ret;				\
154	gi->cdev.desc._name = val;			\
155	return len;					\
156}
157
158#define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
159	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
160		const char *page, size_t len)		\
161{							\
162	u16 val;					\
163	int ret;					\
164	ret = kstrtou16(page, 0, &val);			\
165	if (ret)					\
166		return ret;				\
167	gi->cdev.desc._name = cpu_to_le16p(&val);	\
168	return len;					\
169}
170
171#define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
172	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
173	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
174
175GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
176GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
177GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
178GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
179GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
180GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
181GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
182GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
183
184static ssize_t is_valid_bcd(u16 bcd_val)
185{
186	if ((bcd_val & 0xf) > 9)
187		return -EINVAL;
188	if (((bcd_val >> 4) & 0xf) > 9)
189		return -EINVAL;
190	if (((bcd_val >> 8) & 0xf) > 9)
191		return -EINVAL;
192	if (((bcd_val >> 12) & 0xf) > 9)
193		return -EINVAL;
194	return 0;
195}
196
197static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
198		const char *page, size_t len)
199{
200	u16 bcdDevice;
201	int ret;
202
203	ret = kstrtou16(page, 0, &bcdDevice);
204	if (ret)
205		return ret;
206	ret = is_valid_bcd(bcdDevice);
207	if (ret)
208		return ret;
209
210	gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
211	return len;
212}
213
214static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
215		const char *page, size_t len)
216{
217	u16 bcdUSB;
218	int ret;
219
220	ret = kstrtou16(page, 0, &bcdUSB);
221	if (ret)
222		return ret;
223	ret = is_valid_bcd(bcdUSB);
224	if (ret)
225		return ret;
226
227	gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
228	return len;
229}
230
231static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
232{
233	return sprintf(page, "%s\n", gi->udc_name ?: "");
234}
235
236static int unregister_gadget(struct gadget_info *gi)
237{
238	int ret;
239
240	if (!gi->udc_name)
241		return -ENODEV;
242
243	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
244	if (ret)
245		return ret;
246	kfree(gi->udc_name);
247	gi->udc_name = NULL;
248	return 0;
249}
250
251static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
252		const char *page, size_t len)
253{
254	char *name;
255	int ret;
256
257	name = kstrdup(page, GFP_KERNEL);
258	if (!name)
259		return -ENOMEM;
260	if (name[len - 1] == '\n')
261		name[len - 1] = '\0';
262
263	mutex_lock(&gi->lock);
264
265	if (!strlen(name)) {
266		ret = unregister_gadget(gi);
267		if (ret)
268			goto err;
269	} else {
270		if (gi->udc_name) {
271			ret = -EBUSY;
272			goto err;
273		}
274		ret = usb_udc_attach_driver(name, &gi->composite.gadget_driver);
275		if (ret)
276			goto err;
277		gi->udc_name = name;
278	}
279	mutex_unlock(&gi->lock);
280	return len;
281err:
282	kfree(name);
283	mutex_unlock(&gi->lock);
284	return ret;
285}
286
287GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
288GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
289GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
290GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
291GI_DEVICE_DESC_ITEM_ATTR(idVendor);
292GI_DEVICE_DESC_ITEM_ATTR(idProduct);
293GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
294GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
295GI_DEVICE_DESC_ITEM_ATTR(UDC);
296
297static struct configfs_attribute *gadget_root_attrs[] = {
298	&gadget_cdev_desc_bDeviceClass.attr,
299	&gadget_cdev_desc_bDeviceSubClass.attr,
300	&gadget_cdev_desc_bDeviceProtocol.attr,
301	&gadget_cdev_desc_bMaxPacketSize0.attr,
302	&gadget_cdev_desc_idVendor.attr,
303	&gadget_cdev_desc_idProduct.attr,
304	&gadget_cdev_desc_bcdDevice.attr,
305	&gadget_cdev_desc_bcdUSB.attr,
306	&gadget_cdev_desc_UDC.attr,
307	NULL,
308};
309
310static inline struct gadget_info *to_gadget_info(struct config_item *item)
311{
312	 return container_of(to_config_group(item), struct gadget_info, group);
313}
314
315static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
316{
317	 return container_of(to_config_group(item), struct gadget_strings,
318			 group);
319}
320
321static inline struct gadget_config_name *to_gadget_config_name(
322		struct config_item *item)
323{
324	 return container_of(to_config_group(item), struct gadget_config_name,
325			 group);
326}
327
328static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
329{
330	return container_of(to_config_group(item), struct config_usb_cfg,
331			group);
332}
333
334static inline struct usb_function_instance *to_usb_function_instance(
335		struct config_item *item)
336{
337	 return container_of(to_config_group(item),
338			 struct usb_function_instance, group);
339}
340
341static void gadget_info_attr_release(struct config_item *item)
342{
343	struct gadget_info *gi = to_gadget_info(item);
344
345	WARN_ON(!list_empty(&gi->cdev.configs));
346	WARN_ON(!list_empty(&gi->string_list));
347	WARN_ON(!list_empty(&gi->available_func));
348	kfree(gi->composite.gadget_driver.function);
349	kfree(gi);
350}
351
352CONFIGFS_ATTR_OPS(gadget_info);
353
354static struct configfs_item_operations gadget_root_item_ops = {
355	.release                = gadget_info_attr_release,
356	.show_attribute         = gadget_info_attr_show,
357	.store_attribute        = gadget_info_attr_store,
358};
359
360static void gadget_config_attr_release(struct config_item *item)
361{
362	struct config_usb_cfg *cfg = to_config_usb_cfg(item);
363
364	WARN_ON(!list_empty(&cfg->c.functions));
365	list_del(&cfg->c.list);
366	kfree(cfg->c.label);
367	kfree(cfg);
368}
369
370static int config_usb_cfg_link(
371	struct config_item *usb_cfg_ci,
372	struct config_item *usb_func_ci)
373{
374	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
375	struct usb_composite_dev *cdev = cfg->c.cdev;
376	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
377
378	struct config_group *group = to_config_group(usb_func_ci);
379	struct usb_function_instance *fi = container_of(group,
380			struct usb_function_instance, group);
381	struct usb_function_instance *a_fi;
382	struct usb_function *f;
383	int ret;
384
385	mutex_lock(&gi->lock);
386	/*
387	 * Make sure this function is from within our _this_ gadget and not
388	 * from another gadget or a random directory.
389	 * Also a function instance can only be linked once.
390	 */
391	list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
392		if (a_fi == fi)
393			break;
394	}
395	if (a_fi != fi) {
396		ret = -EINVAL;
397		goto out;
398	}
399
400	list_for_each_entry(f, &cfg->func_list, list) {
401		if (f->fi == fi) {
402			ret = -EEXIST;
403			goto out;
404		}
405	}
406
407	f = usb_get_function(fi);
408	if (IS_ERR(f)) {
409		ret = PTR_ERR(f);
410		goto out;
411	}
412
413	/* stash the function until we bind it to the gadget */
414	list_add_tail(&f->list, &cfg->func_list);
415	ret = 0;
416out:
417	mutex_unlock(&gi->lock);
418	return ret;
419}
420
421static int config_usb_cfg_unlink(
422	struct config_item *usb_cfg_ci,
423	struct config_item *usb_func_ci)
424{
425	struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
426	struct usb_composite_dev *cdev = cfg->c.cdev;
427	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
428
429	struct config_group *group = to_config_group(usb_func_ci);
430	struct usb_function_instance *fi = container_of(group,
431			struct usb_function_instance, group);
432	struct usb_function *f;
433
434	/*
435	 * ideally I would like to forbid to unlink functions while a gadget is
436	 * bound to an UDC. Since this isn't possible at the moment, we simply
437	 * force an unbind, the function is available here and then we can
438	 * remove the function.
439	 */
440	mutex_lock(&gi->lock);
441	if (gi->udc_name)
442		unregister_gadget(gi);
443	WARN_ON(gi->udc_name);
444
445	list_for_each_entry(f, &cfg->func_list, list) {
446		if (f->fi == fi) {
447			list_del(&f->list);
448			usb_put_function(f);
449			mutex_unlock(&gi->lock);
450			return 0;
451		}
452	}
453	mutex_unlock(&gi->lock);
454	WARN(1, "Unable to locate function to unbind\n");
455	return 0;
456}
457
458CONFIGFS_ATTR_OPS(config_usb_cfg);
459
460static struct configfs_item_operations gadget_config_item_ops = {
461	.release                = gadget_config_attr_release,
462	.show_attribute         = config_usb_cfg_attr_show,
463	.store_attribute        = config_usb_cfg_attr_store,
464	.allow_link             = config_usb_cfg_link,
465	.drop_link              = config_usb_cfg_unlink,
466};
467
468
469static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
470		char *page)
471{
472	return sprintf(page, "%u\n", cfg->c.MaxPower);
473}
474
475static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
476		const char *page, size_t len)
477{
478	u16 val;
479	int ret;
480	ret = kstrtou16(page, 0, &val);
481	if (ret)
482		return ret;
483	if (DIV_ROUND_UP(val, 8) > 0xff)
484		return -ERANGE;
485	cfg->c.MaxPower = val;
486	return len;
487}
488
489static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
490		char *page)
491{
492	return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
493}
494
495static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
496		const char *page, size_t len)
497{
498	u8 val;
499	int ret;
500	ret = kstrtou8(page, 0, &val);
501	if (ret)
502		return ret;
503	if (!(val & USB_CONFIG_ATT_ONE))
504		return -EINVAL;
505	if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
506				USB_CONFIG_ATT_WAKEUP))
507		return -EINVAL;
508	cfg->c.bmAttributes = val;
509	return len;
510}
511
512#define CFG_CONFIG_DESC_ITEM_ATTR(name)	\
513	static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
514		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
515				gadget_config_desc_##name##_show,	\
516				gadget_config_desc_##name##_store)
517
518CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
519CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
520
521static struct configfs_attribute *gadget_config_attrs[] = {
522	&gadget_usb_cfg_MaxPower.attr,
523	&gadget_usb_cfg_bmAttributes.attr,
524	NULL,
525};
526
527static struct config_item_type gadget_config_type = {
528	.ct_item_ops	= &gadget_config_item_ops,
529	.ct_attrs	= gadget_config_attrs,
530	.ct_owner	= THIS_MODULE,
531};
532
533static struct config_item_type gadget_root_type = {
534	.ct_item_ops	= &gadget_root_item_ops,
535	.ct_attrs	= gadget_root_attrs,
536	.ct_owner	= THIS_MODULE,
537};
538
539static void composite_init_dev(struct usb_composite_dev *cdev)
540{
541	spin_lock_init(&cdev->lock);
542	INIT_LIST_HEAD(&cdev->configs);
543	INIT_LIST_HEAD(&cdev->gstrings);
544}
545
546static struct config_group *function_make(
547		struct config_group *group,
548		const char *name)
549{
550	struct gadget_info *gi;
551	struct usb_function_instance *fi;
552	char buf[MAX_NAME_LEN];
553	char *func_name;
554	char *instance_name;
555	int ret;
556
557	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
558	if (ret >= MAX_NAME_LEN)
559		return ERR_PTR(-ENAMETOOLONG);
560
561	func_name = buf;
562	instance_name = strchr(func_name, '.');
563	if (!instance_name) {
564		pr_err("Unable to locate . in FUNC.INSTANCE\n");
565		return ERR_PTR(-EINVAL);
566	}
567	*instance_name = '\0';
568	instance_name++;
569
570	fi = usb_get_function_instance(func_name);
571	if (IS_ERR(fi))
572		return ERR_CAST(fi);
573
574	ret = config_item_set_name(&fi->group.cg_item, name);
575	if (ret) {
576		usb_put_function_instance(fi);
577		return ERR_PTR(ret);
578	}
579	if (fi->set_inst_name) {
580		ret = fi->set_inst_name(fi, instance_name);
581		if (ret) {
582			usb_put_function_instance(fi);
583			return ERR_PTR(ret);
584		}
585	}
586
587	gi = container_of(group, struct gadget_info, functions_group);
588
589	mutex_lock(&gi->lock);
590	list_add_tail(&fi->cfs_list, &gi->available_func);
591	mutex_unlock(&gi->lock);
592	return &fi->group;
593}
594
595static void function_drop(
596		struct config_group *group,
597		struct config_item *item)
598{
599	struct usb_function_instance *fi = to_usb_function_instance(item);
600	struct gadget_info *gi;
601
602	gi = container_of(group, struct gadget_info, functions_group);
603
604	mutex_lock(&gi->lock);
605	list_del(&fi->cfs_list);
606	mutex_unlock(&gi->lock);
607	config_item_put(item);
608}
609
610static struct configfs_group_operations functions_ops = {
611	.make_group     = &function_make,
612	.drop_item      = &function_drop,
613};
614
615static struct config_item_type functions_type = {
616	.ct_group_ops   = &functions_ops,
617	.ct_owner       = THIS_MODULE,
618};
619
620CONFIGFS_ATTR_STRUCT(gadget_config_name);
621GS_STRINGS_RW(gadget_config_name, configuration);
622
623static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
624	&gadget_config_name_configuration.attr,
625	NULL,
626};
627
628static void gadget_config_name_attr_release(struct config_item *item)
629{
630	struct gadget_config_name *cn = to_gadget_config_name(item);
631
632	kfree(cn->configuration);
633
634	list_del(&cn->list);
635	kfree(cn);
636}
637
638USB_CONFIG_STRING_RW_OPS(gadget_config_name);
639USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
640
641static struct config_group *config_desc_make(
642		struct config_group *group,
643		const char *name)
644{
645	struct gadget_info *gi;
646	struct config_usb_cfg *cfg;
647	char buf[MAX_NAME_LEN];
648	char *num_str;
649	u8 num;
650	int ret;
651
652	gi = container_of(group, struct gadget_info, configs_group);
653	ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
654	if (ret >= MAX_NAME_LEN)
655		return ERR_PTR(-ENAMETOOLONG);
656
657	num_str = strchr(buf, '.');
658	if (!num_str) {
659		pr_err("Unable to locate . in name.bConfigurationValue\n");
660		return ERR_PTR(-EINVAL);
661	}
662
663	*num_str = '\0';
664	num_str++;
665
666	if (!strlen(buf))
667		return ERR_PTR(-EINVAL);
668
669	ret = kstrtou8(num_str, 0, &num);
670	if (ret)
671		return ERR_PTR(ret);
672
673	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
674	if (!cfg)
675		return ERR_PTR(-ENOMEM);
676	cfg->c.label = kstrdup(buf, GFP_KERNEL);
677	if (!cfg->c.label) {
678		ret = -ENOMEM;
679		goto err;
680	}
681	cfg->c.bConfigurationValue = num;
682	cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
683	cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
684	INIT_LIST_HEAD(&cfg->string_list);
685	INIT_LIST_HEAD(&cfg->func_list);
686
687	cfg->group.default_groups = cfg->default_groups;
688	cfg->default_groups[0] = &cfg->strings_group;
689
690	config_group_init_type_name(&cfg->group, name,
691				&gadget_config_type);
692	config_group_init_type_name(&cfg->strings_group, "strings",
693			&gadget_config_name_strings_type);
694
695	ret = usb_add_config_only(&gi->cdev, &cfg->c);
696	if (ret)
697		goto err;
698
699	return &cfg->group;
700err:
701	kfree(cfg->c.label);
702	kfree(cfg);
703	return ERR_PTR(ret);
704}
705
706static void config_desc_drop(
707		struct config_group *group,
708		struct config_item *item)
709{
710	config_item_put(item);
711}
712
713static struct configfs_group_operations config_desc_ops = {
714	.make_group     = &config_desc_make,
715	.drop_item      = &config_desc_drop,
716};
717
718static struct config_item_type config_desc_type = {
719	.ct_group_ops   = &config_desc_ops,
720	.ct_owner       = THIS_MODULE,
721};
722
723CONFIGFS_ATTR_STRUCT(gadget_strings);
724GS_STRINGS_RW(gadget_strings, manufacturer);
725GS_STRINGS_RW(gadget_strings, product);
726GS_STRINGS_RW(gadget_strings, serialnumber);
727
728static struct configfs_attribute *gadget_strings_langid_attrs[] = {
729	&gadget_strings_manufacturer.attr,
730	&gadget_strings_product.attr,
731	&gadget_strings_serialnumber.attr,
732	NULL,
733};
734
735static void gadget_strings_attr_release(struct config_item *item)
736{
737	struct gadget_strings *gs = to_gadget_strings(item);
738
739	kfree(gs->manufacturer);
740	kfree(gs->product);
741	kfree(gs->serialnumber);
742
743	list_del(&gs->list);
744	kfree(gs);
745}
746
747USB_CONFIG_STRING_RW_OPS(gadget_strings);
748USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
749
750static inline struct os_desc *to_os_desc(struct config_item *item)
751{
752	return container_of(to_config_group(item), struct os_desc, group);
753}
754
755CONFIGFS_ATTR_STRUCT(os_desc);
756CONFIGFS_ATTR_OPS(os_desc);
757
758static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
759{
760	struct gadget_info *gi;
761
762	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
763
764	return sprintf(page, "%d", gi->use_os_desc);
765}
766
767static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
768				 size_t len)
769{
770	struct gadget_info *gi;
771	int ret;
772	bool use;
773
774	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
775
776	mutex_lock(&gi->lock);
777	ret = strtobool(page, &use);
778	if (!ret) {
779		gi->use_os_desc = use;
780		ret = len;
781	}
782	mutex_unlock(&gi->lock);
783
784	return ret;
785}
786
787static struct os_desc_attribute os_desc_use =
788	__CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
789			os_desc_use_show,
790			os_desc_use_store);
791
792static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
793{
794	struct gadget_info *gi;
795
796	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
797
798	return sprintf(page, "%d", gi->b_vendor_code);
799}
800
801static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
802					   const char *page, size_t len)
803{
804	struct gadget_info *gi;
805	int ret;
806	u8 b_vendor_code;
807
808	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
809
810	mutex_lock(&gi->lock);
811	ret = kstrtou8(page, 0, &b_vendor_code);
812	if (!ret) {
813		gi->b_vendor_code = b_vendor_code;
814		ret = len;
815	}
816	mutex_unlock(&gi->lock);
817
818	return ret;
819}
820
821static struct os_desc_attribute os_desc_b_vendor_code =
822	__CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
823			os_desc_b_vendor_code_show,
824			os_desc_b_vendor_code_store);
825
826static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
827{
828	struct gadget_info *gi;
829
830	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
831
832	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
833
834	return OS_STRING_QW_SIGN_LEN;
835}
836
837static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
838				     size_t len)
839{
840	struct gadget_info *gi;
841	int res, l;
842
843	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
844	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
845	if (page[l - 1] == '\n')
846		--l;
847
848	mutex_lock(&gi->lock);
849	res = utf8s_to_utf16s(page, l,
850			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
851			      OS_STRING_QW_SIGN_LEN);
852	if (res > 0)
853		res = len;
854	mutex_unlock(&gi->lock);
855
856	return res;
857}
858
859static struct os_desc_attribute os_desc_qw_sign =
860	__CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
861			os_desc_qw_sign_show,
862			os_desc_qw_sign_store);
863
864static struct configfs_attribute *os_desc_attrs[] = {
865	&os_desc_use.attr,
866	&os_desc_b_vendor_code.attr,
867	&os_desc_qw_sign.attr,
868	NULL,
869};
870
871static void os_desc_attr_release(struct config_item *item)
872{
873	struct os_desc *os_desc = to_os_desc(item);
874	kfree(os_desc);
875}
876
877static int os_desc_link(struct config_item *os_desc_ci,
878			struct config_item *usb_cfg_ci)
879{
880	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
881					struct gadget_info, os_desc_group);
882	struct usb_composite_dev *cdev = &gi->cdev;
883	struct config_usb_cfg *c_target =
884		container_of(to_config_group(usb_cfg_ci),
885			     struct config_usb_cfg, group);
886	struct usb_configuration *c;
887	int ret;
888
889	mutex_lock(&gi->lock);
890	list_for_each_entry(c, &cdev->configs, list) {
891		if (c == &c_target->c)
892			break;
893	}
894	if (c != &c_target->c) {
895		ret = -EINVAL;
896		goto out;
897	}
898
899	if (cdev->os_desc_config) {
900		ret = -EBUSY;
901		goto out;
902	}
903
904	cdev->os_desc_config = &c_target->c;
905	ret = 0;
906
907out:
908	mutex_unlock(&gi->lock);
909	return ret;
910}
911
912static int os_desc_unlink(struct config_item *os_desc_ci,
913			  struct config_item *usb_cfg_ci)
914{
915	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
916					struct gadget_info, os_desc_group);
917	struct usb_composite_dev *cdev = &gi->cdev;
918
919	mutex_lock(&gi->lock);
920	if (gi->udc_name)
921		unregister_gadget(gi);
922	cdev->os_desc_config = NULL;
923	WARN_ON(gi->udc_name);
924	mutex_unlock(&gi->lock);
925	return 0;
926}
927
928static struct configfs_item_operations os_desc_ops = {
929	.release                = os_desc_attr_release,
930	.show_attribute         = os_desc_attr_show,
931	.store_attribute        = os_desc_attr_store,
932	.allow_link		= os_desc_link,
933	.drop_link		= os_desc_unlink,
934};
935
936static 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
942CONFIGFS_ATTR_STRUCT(usb_os_desc);
943CONFIGFS_ATTR_OPS(usb_os_desc);
944
945
946static inline struct usb_os_desc_ext_prop
947*to_usb_os_desc_ext_prop(struct config_item *item)
948{
949	return container_of(item, struct usb_os_desc_ext_prop, item);
950}
951
952CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop);
953CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop);
954
955static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop,
956				  char *page)
957{
958	return sprintf(page, "%d", ext_prop->type);
959}
960
961static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop,
962				   const char *page, size_t len)
963{
964	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
965	u8 type;
966	int ret;
967
968	if (desc->opts_mutex)
969		mutex_lock(desc->opts_mutex);
970	ret = kstrtou8(page, 0, &type);
971	if (ret)
972		goto end;
973	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
974		ret = -EINVAL;
975		goto end;
976	}
977
978	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
979	    ext_prop->type == USB_EXT_PROP_LE32 ||
980	    ext_prop->type == USB_EXT_PROP_BE32) &&
981	    (type == USB_EXT_PROP_UNICODE ||
982	    type == USB_EXT_PROP_UNICODE_ENV ||
983	    type == USB_EXT_PROP_UNICODE_LINK))
984		ext_prop->data_len <<= 1;
985	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
986		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
987		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
988		   (type == USB_EXT_PROP_BINARY ||
989		   type == USB_EXT_PROP_LE32 ||
990		   type == USB_EXT_PROP_BE32))
991		ext_prop->data_len >>= 1;
992	ext_prop->type = type;
993	ret = len;
994
995end:
996	if (desc->opts_mutex)
997		mutex_unlock(desc->opts_mutex);
998	return ret;
999}
1000
1001static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
1002				  char *page)
1003{
1004	int len = ext_prop->data_len;
1005
1006	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1007	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1008	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
1009		len >>= 1;
1010	memcpy(page, ext_prop->data, len);
1011
1012	return len;
1013}
1014
1015static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
1016				   const char *page, size_t len)
1017{
1018	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
1019	char *new_data;
1020	size_t ret_len = len;
1021
1022	if (page[len - 1] == '\n' || page[len - 1] == '\0')
1023		--len;
1024	new_data = kmemdup(page, len, GFP_KERNEL);
1025	if (!new_data)
1026		return -ENOMEM;
1027
1028	if (desc->opts_mutex)
1029		mutex_lock(desc->opts_mutex);
1030	kfree(ext_prop->data);
1031	ext_prop->data = new_data;
1032	desc->ext_prop_len -= ext_prop->data_len;
1033	ext_prop->data_len = len;
1034	desc->ext_prop_len += ext_prop->data_len;
1035	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
1036	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
1037	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
1038		desc->ext_prop_len -= ext_prop->data_len;
1039		ext_prop->data_len <<= 1;
1040		ext_prop->data_len += 2;
1041		desc->ext_prop_len += ext_prop->data_len;
1042	}
1043	if (desc->opts_mutex)
1044		mutex_unlock(desc->opts_mutex);
1045	return ret_len;
1046}
1047
1048static struct usb_os_desc_ext_prop_attribute ext_prop_type =
1049	__CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR,
1050			ext_prop_type_show, ext_prop_type_store);
1051
1052static struct usb_os_desc_ext_prop_attribute ext_prop_data =
1053	__CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR,
1054			ext_prop_data_show, ext_prop_data_store);
1055
1056static struct configfs_attribute *ext_prop_attrs[] = {
1057	&ext_prop_type.attr,
1058	&ext_prop_data.attr,
1059	NULL,
1060};
1061
1062static void usb_os_desc_ext_prop_release(struct config_item *item)
1063{
1064	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1065
1066	kfree(ext_prop); /* frees a whole chunk */
1067}
1068
1069static struct configfs_item_operations ext_prop_ops = {
1070	.release		= usb_os_desc_ext_prop_release,
1071	.show_attribute		= usb_os_desc_ext_prop_attr_show,
1072	.store_attribute	= usb_os_desc_ext_prop_attr_store,
1073};
1074
1075static struct config_item *ext_prop_make(
1076		struct config_group *group,
1077		const char *name)
1078{
1079	struct usb_os_desc_ext_prop *ext_prop;
1080	struct config_item_type *ext_prop_type;
1081	struct usb_os_desc *desc;
1082	char *vlabuf;
1083
1084	vla_group(data_chunk);
1085	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
1086	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
1087
1088	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1089	if (!vlabuf)
1090		return ERR_PTR(-ENOMEM);
1091
1092	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
1093	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
1094
1095	desc = container_of(group, struct usb_os_desc, group);
1096	ext_prop_type->ct_item_ops = &ext_prop_ops;
1097	ext_prop_type->ct_attrs = ext_prop_attrs;
1098	ext_prop_type->ct_owner = desc->owner;
1099
1100	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
1101
1102	ext_prop->name = kstrdup(name, GFP_KERNEL);
1103	if (!ext_prop->name) {
1104		kfree(vlabuf);
1105		return ERR_PTR(-ENOMEM);
1106	}
1107	desc->ext_prop_len += 14;
1108	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
1109	if (desc->opts_mutex)
1110		mutex_lock(desc->opts_mutex);
1111	desc->ext_prop_len += ext_prop->name_len;
1112	list_add_tail(&ext_prop->entry, &desc->ext_prop);
1113	++desc->ext_prop_count;
1114	if (desc->opts_mutex)
1115		mutex_unlock(desc->opts_mutex);
1116
1117	return &ext_prop->item;
1118}
1119
1120static void ext_prop_drop(struct config_group *group, struct config_item *item)
1121{
1122	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
1123	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
1124
1125	if (desc->opts_mutex)
1126		mutex_lock(desc->opts_mutex);
1127	list_del(&ext_prop->entry);
1128	--desc->ext_prop_count;
1129	kfree(ext_prop->name);
1130	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
1131	if (desc->opts_mutex)
1132		mutex_unlock(desc->opts_mutex);
1133	config_item_put(item);
1134}
1135
1136static struct configfs_group_operations interf_grp_ops = {
1137	.make_item	= &ext_prop_make,
1138	.drop_item	= &ext_prop_drop,
1139};
1140
1141static struct configfs_item_operations interf_item_ops = {
1142	.show_attribute		= usb_os_desc_attr_show,
1143	.store_attribute	= usb_os_desc_attr_store,
1144};
1145
1146static ssize_t interf_grp_compatible_id_show(struct usb_os_desc *desc,
1147					     char *page)
1148{
1149	memcpy(page, desc->ext_compat_id, 8);
1150	return 8;
1151}
1152
1153static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc,
1154					      const char *page, size_t len)
1155{
1156	int l;
1157
1158	l = min_t(int, 8, len);
1159	if (page[l - 1] == '\n')
1160		--l;
1161	if (desc->opts_mutex)
1162		mutex_lock(desc->opts_mutex);
1163	memcpy(desc->ext_compat_id, page, l);
1164
1165	if (desc->opts_mutex)
1166		mutex_unlock(desc->opts_mutex);
1167
1168	return len;
1169}
1170
1171static struct usb_os_desc_attribute interf_grp_attr_compatible_id =
1172	__CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
1173			interf_grp_compatible_id_show,
1174			interf_grp_compatible_id_store);
1175
1176static ssize_t interf_grp_sub_compatible_id_show(struct usb_os_desc *desc,
1177						 char *page)
1178{
1179	memcpy(page, desc->ext_compat_id + 8, 8);
1180	return 8;
1181}
1182
1183static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc,
1184						  const char *page, size_t len)
1185{
1186	int l;
1187
1188	l = min_t(int, 8, len);
1189	if (page[l - 1] == '\n')
1190		--l;
1191	if (desc->opts_mutex)
1192		mutex_lock(desc->opts_mutex);
1193	memcpy(desc->ext_compat_id + 8, page, l);
1194
1195	if (desc->opts_mutex)
1196		mutex_unlock(desc->opts_mutex);
1197
1198	return len;
1199}
1200
1201static struct usb_os_desc_attribute interf_grp_attr_sub_compatible_id =
1202	__CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
1203			interf_grp_sub_compatible_id_show,
1204			interf_grp_sub_compatible_id_store);
1205
1206static struct configfs_attribute *interf_grp_attrs[] = {
1207	&interf_grp_attr_compatible_id.attr,
1208	&interf_grp_attr_sub_compatible_id.attr,
1209	NULL
1210};
1211
1212int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1213				   int n_interf,
1214				   struct usb_os_desc **desc,
1215				   char **names,
1216				   struct module *owner)
1217{
1218	struct config_group **f_default_groups, *os_desc_group,
1219				**interface_groups;
1220	struct config_item_type *os_desc_type, *interface_type;
1221
1222	vla_group(data_chunk);
1223	vla_item(data_chunk, struct config_group *, f_default_groups, 2);
1224	vla_item(data_chunk, struct config_group, os_desc_group, 1);
1225	vla_item(data_chunk, struct config_group *, interface_groups,
1226		 n_interf + 1);
1227	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1228	vla_item(data_chunk, struct config_item_type, interface_type, 1);
1229
1230	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1231	if (!vlabuf)
1232		return -ENOMEM;
1233
1234	f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
1235	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1236	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1237	interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
1238	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1239
1240	parent->default_groups = f_default_groups;
1241	os_desc_type->ct_owner = owner;
1242	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1243	f_default_groups[0] = os_desc_group;
1244
1245	os_desc_group->default_groups = interface_groups;
1246	interface_type->ct_item_ops = &interf_item_ops;
1247	interface_type->ct_group_ops = &interf_grp_ops;
1248	interface_type->ct_attrs = interf_grp_attrs;
1249	interface_type->ct_owner = owner;
1250
1251	while (n_interf--) {
1252		struct usb_os_desc *d;
1253
1254		d = desc[n_interf];
1255		d->owner = owner;
1256		config_group_init_type_name(&d->group, "", interface_type);
1257		config_item_set_name(&d->group.cg_item, "interface.%s",
1258				     names[n_interf]);
1259		interface_groups[n_interf] = &d->group;
1260	}
1261
1262	return 0;
1263}
1264EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1265
1266static int configfs_do_nothing(struct usb_composite_dev *cdev)
1267{
1268	WARN_ON(1);
1269	return -EINVAL;
1270}
1271
1272int composite_dev_prepare(struct usb_composite_driver *composite,
1273		struct usb_composite_dev *dev);
1274
1275int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1276				  struct usb_ep *ep0);
1277
1278static void purge_configs_funcs(struct gadget_info *gi)
1279{
1280	struct usb_configuration	*c;
1281
1282	list_for_each_entry(c, &gi->cdev.configs, list) {
1283		struct usb_function *f, *tmp;
1284		struct config_usb_cfg *cfg;
1285
1286		cfg = container_of(c, struct config_usb_cfg, c);
1287
1288		list_for_each_entry_safe(f, tmp, &c->functions, list) {
1289
1290			list_move_tail(&f->list, &cfg->func_list);
1291			if (f->unbind) {
1292				dev_err(&gi->cdev.gadget->dev, "unbind function"
1293						" '%s'/%p\n", f->name, f);
1294				f->unbind(c, f);
1295			}
1296		}
1297		c->next_interface_id = 0;
1298		memset(c->interface, 0, sizeof(c->interface));
1299		c->superspeed = 0;
1300		c->highspeed = 0;
1301		c->fullspeed = 0;
1302	}
1303}
1304
1305static int configfs_composite_bind(struct usb_gadget *gadget,
1306		struct usb_gadget_driver *gdriver)
1307{
1308	struct usb_composite_driver     *composite = to_cdriver(gdriver);
1309	struct gadget_info		*gi = container_of(composite,
1310						struct gadget_info, composite);
1311	struct usb_composite_dev	*cdev = &gi->cdev;
1312	struct usb_configuration	*c;
1313	struct usb_string		*s;
1314	unsigned			i;
1315	int				ret;
1316
1317	/* the gi->lock is hold by the caller */
1318	cdev->gadget = gadget;
1319	set_gadget_data(gadget, cdev);
1320	ret = composite_dev_prepare(composite, cdev);
1321	if (ret)
1322		return ret;
1323	/* and now the gadget bind */
1324	ret = -EINVAL;
1325
1326	if (list_empty(&gi->cdev.configs)) {
1327		pr_err("Need at least one configuration in %s.\n",
1328				gi->composite.name);
1329		goto err_comp_cleanup;
1330	}
1331
1332
1333	list_for_each_entry(c, &gi->cdev.configs, list) {
1334		struct config_usb_cfg *cfg;
1335
1336		cfg = container_of(c, struct config_usb_cfg, c);
1337		if (list_empty(&cfg->func_list)) {
1338			pr_err("Config %s/%d of %s needs at least one function.\n",
1339			      c->label, c->bConfigurationValue,
1340			      gi->composite.name);
1341			goto err_comp_cleanup;
1342		}
1343	}
1344
1345	/* init all strings */
1346	if (!list_empty(&gi->string_list)) {
1347		struct gadget_strings *gs;
1348
1349		i = 0;
1350		list_for_each_entry(gs, &gi->string_list, list) {
1351
1352			gi->gstrings[i] = &gs->stringtab_dev;
1353			gs->stringtab_dev.strings = gs->strings;
1354			gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1355				gs->manufacturer;
1356			gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1357			gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1358			i++;
1359		}
1360		gi->gstrings[i] = NULL;
1361		s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1362				USB_GADGET_FIRST_AVAIL_IDX);
1363		if (IS_ERR(s)) {
1364			ret = PTR_ERR(s);
1365			goto err_comp_cleanup;
1366		}
1367
1368		gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1369		gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1370		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1371	}
1372
1373	if (gi->use_os_desc) {
1374		cdev->use_os_string = true;
1375		cdev->b_vendor_code = gi->b_vendor_code;
1376		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1377	}
1378
1379	/* Go through all configs, attach all functions */
1380	list_for_each_entry(c, &gi->cdev.configs, list) {
1381		struct config_usb_cfg *cfg;
1382		struct usb_function *f;
1383		struct usb_function *tmp;
1384		struct gadget_config_name *cn;
1385
1386		cfg = container_of(c, struct config_usb_cfg, c);
1387		if (!list_empty(&cfg->string_list)) {
1388			i = 0;
1389			list_for_each_entry(cn, &cfg->string_list, list) {
1390				cfg->gstrings[i] = &cn->stringtab_dev;
1391				cn->stringtab_dev.strings = &cn->strings;
1392				cn->strings.s = cn->configuration;
1393				i++;
1394			}
1395			cfg->gstrings[i] = NULL;
1396			s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1397			if (IS_ERR(s)) {
1398				ret = PTR_ERR(s);
1399				goto err_comp_cleanup;
1400			}
1401			c->iConfiguration = s[0].id;
1402		}
1403
1404		list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1405			list_del(&f->list);
1406			ret = usb_add_function(c, f);
1407			if (ret) {
1408				list_add(&f->list, &cfg->func_list);
1409				goto err_purge_funcs;
1410			}
1411		}
1412		usb_ep_autoconfig_reset(cdev->gadget);
1413	}
1414	if (cdev->use_os_string) {
1415		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1416		if (ret)
1417			goto err_purge_funcs;
1418	}
1419
1420	usb_ep_autoconfig_reset(cdev->gadget);
1421	return 0;
1422
1423err_purge_funcs:
1424	purge_configs_funcs(gi);
1425err_comp_cleanup:
1426	composite_dev_cleanup(cdev);
1427	return ret;
1428}
1429
1430static void configfs_composite_unbind(struct usb_gadget *gadget)
1431{
1432	struct usb_composite_dev	*cdev;
1433	struct gadget_info		*gi;
1434
1435	/* the gi->lock is hold by the caller */
1436
1437	cdev = get_gadget_data(gadget);
1438	gi = container_of(cdev, struct gadget_info, cdev);
1439
1440	purge_configs_funcs(gi);
1441	composite_dev_cleanup(cdev);
1442	usb_ep_autoconfig_reset(cdev->gadget);
1443	cdev->gadget = NULL;
1444	set_gadget_data(gadget, NULL);
1445}
1446
1447static const struct usb_gadget_driver configfs_driver_template = {
1448	.bind           = configfs_composite_bind,
1449	.unbind         = configfs_composite_unbind,
1450
1451	.setup          = composite_setup,
1452	.reset          = composite_disconnect,
1453	.disconnect     = composite_disconnect,
1454
1455	.suspend	= composite_suspend,
1456	.resume		= composite_resume,
1457
1458	.max_speed	= USB_SPEED_SUPER,
1459	.driver = {
1460		.owner          = THIS_MODULE,
1461		.name		= "configfs-gadget",
1462	},
1463};
1464
1465static struct config_group *gadgets_make(
1466		struct config_group *group,
1467		const char *name)
1468{
1469	struct gadget_info *gi;
1470
1471	gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1472	if (!gi)
1473		return ERR_PTR(-ENOMEM);
1474
1475	gi->group.default_groups = gi->default_groups;
1476	gi->group.default_groups[0] = &gi->functions_group;
1477	gi->group.default_groups[1] = &gi->configs_group;
1478	gi->group.default_groups[2] = &gi->strings_group;
1479	gi->group.default_groups[3] = &gi->os_desc_group;
1480
1481	config_group_init_type_name(&gi->functions_group, "functions",
1482			&functions_type);
1483	config_group_init_type_name(&gi->configs_group, "configs",
1484			&config_desc_type);
1485	config_group_init_type_name(&gi->strings_group, "strings",
1486			&gadget_strings_strings_type);
1487	config_group_init_type_name(&gi->os_desc_group, "os_desc",
1488			&os_desc_type);
1489
1490	gi->composite.bind = configfs_do_nothing;
1491	gi->composite.unbind = configfs_do_nothing;
1492	gi->composite.suspend = NULL;
1493	gi->composite.resume = NULL;
1494	gi->composite.max_speed = USB_SPEED_SUPER;
1495
1496	mutex_init(&gi->lock);
1497	INIT_LIST_HEAD(&gi->string_list);
1498	INIT_LIST_HEAD(&gi->available_func);
1499
1500	composite_init_dev(&gi->cdev);
1501	gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1502	gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1503	gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1504
1505	gi->composite.gadget_driver = configfs_driver_template;
1506
1507	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1508	gi->composite.name = gi->composite.gadget_driver.function;
1509
1510	if (!gi->composite.gadget_driver.function)
1511		goto err;
1512
1513#ifdef CONFIG_USB_OTG
1514	gi->otg.bLength = sizeof(struct usb_otg_descriptor);
1515	gi->otg.bDescriptorType = USB_DT_OTG;
1516	gi->otg.bmAttributes = USB_OTG_SRP | USB_OTG_HNP;
1517#endif
1518
1519	config_group_init_type_name(&gi->group, name,
1520				&gadget_root_type);
1521	return &gi->group;
1522err:
1523	kfree(gi);
1524	return ERR_PTR(-ENOMEM);
1525}
1526
1527static void gadgets_drop(struct config_group *group, struct config_item *item)
1528{
1529	config_item_put(item);
1530}
1531
1532static struct configfs_group_operations gadgets_ops = {
1533	.make_group     = &gadgets_make,
1534	.drop_item      = &gadgets_drop,
1535};
1536
1537static struct config_item_type gadgets_type = {
1538	.ct_group_ops   = &gadgets_ops,
1539	.ct_owner       = THIS_MODULE,
1540};
1541
1542static struct configfs_subsystem gadget_subsys = {
1543	.su_group = {
1544		.cg_item = {
1545			.ci_namebuf = "usb_gadget",
1546			.ci_type = &gadgets_type,
1547		},
1548	},
1549	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1550};
1551
1552void unregister_gadget_item(struct config_item *item)
1553{
1554	struct gadget_info *gi = to_gadget_info(item);
1555
1556	unregister_gadget(gi);
1557}
1558EXPORT_SYMBOL_GPL(unregister_gadget_item);
1559
1560static int __init gadget_cfs_init(void)
1561{
1562	int ret;
1563
1564	config_group_init(&gadget_subsys.su_group);
1565
1566	ret = configfs_register_subsystem(&gadget_subsys);
1567	return ret;
1568}
1569module_init(gadget_cfs_init);
1570
1571static void __exit gadget_cfs_exit(void)
1572{
1573	configfs_unregister_subsystem(&gadget_subsys);
1574}
1575module_exit(gadget_cfs_exit);
1576