gadget_configfs.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __GADGET_CONFIGFS__
 3#define __GADGET_CONFIGFS__
 4
 5#include <linux/configfs.h>
 6
 7#define GS_STRINGS_W(__struct, __name)	\
 8static ssize_t __struct##_##__name##_store(struct config_item *item, \
 9		const char *page, size_t len)		\
10{							\
11	struct __struct *gs = to_##__struct(item);	\
12	int ret;					\
13							\
14	ret = usb_string_copy(page, &gs->__name);	\
15	if (ret)					\
16		return ret;				\
17	return len;					\
18}
19
20#define GS_STRINGS_R(__struct, __name)	\
21static ssize_t __struct##_##__name##_show(struct config_item *item, char *page) \
22{	\
23	struct __struct *gs = to_##__struct(item);	\
24	return sprintf(page, "%s\n", gs->__name ?: "");	\
25}
26
27#define GS_STRINGS_RW(struct_name, _name)	\
28	GS_STRINGS_R(struct_name, _name)	\
29	GS_STRINGS_W(struct_name, _name)	\
30	CONFIGFS_ATTR(struct_name##_, _name)
31
32#define USB_CONFIG_STRING_RW_OPS(struct_in)				\
33static struct configfs_item_operations struct_in##_langid_item_ops = {	\
34	.release                = struct_in##_attr_release,		\
35};									\
36									\
37static const struct config_item_type struct_in##_langid_type = {	\
38	.ct_item_ops	= &struct_in##_langid_item_ops,			\
39	.ct_attrs	= struct_in##_langid_attrs,			\
40	.ct_owner	= THIS_MODULE,					\
41}
42
43#define USB_CONFIG_STRINGS_LANG(struct_in, struct_member)	\
44	static struct config_group *struct_in##_strings_make(		\
45			struct config_group *group,			\
46			const char *name)				\
47	{								\
48	struct struct_member *gi;					\
49	struct struct_in *gs;						\
50	struct struct_in *new;						\
51	int langs = 0;							\
52	int ret;							\
53									\
54	new = kzalloc(sizeof(*new), GFP_KERNEL);			\
55	if (!new)							\
56		return ERR_PTR(-ENOMEM);				\
57									\
58	ret = check_user_usb_string(name, &new->stringtab_dev);		\
59	if (ret)							\
60		goto err;						\
61	config_group_init_type_name(&new->group, name,			\
62			&struct_in##_langid_type);			\
63									\
64	gi = container_of(group, struct struct_member, strings_group);	\
65	ret = -EEXIST;							\
66	list_for_each_entry(gs, &gi->string_list, list) {		\
67		if (gs->stringtab_dev.language == new->stringtab_dev.language) \
68			goto err;					\
69		langs++;						\
70	}								\
71	ret = -EOVERFLOW;						\
72	if (langs >= MAX_USB_STRING_LANGS)				\
73		goto err;						\
74									\
75	list_add_tail(&new->list, &gi->string_list);			\
76	return &new->group;						\
77err:									\
78	kfree(new);							\
79	return ERR_PTR(ret);						\
80}									\
81									\
82static void struct_in##_strings_drop(					\
83		struct config_group *group,				\
84		struct config_item *item)				\
85{									\
86	config_item_put(item);						\
87}									\
88									\
89static struct configfs_group_operations struct_in##_strings_ops = {	\
90	.make_group     = &struct_in##_strings_make,			\
91	.drop_item      = &struct_in##_strings_drop,			\
92};									\
93									\
94static const struct config_item_type struct_in##_strings_type = {	\
95	.ct_group_ops   = &struct_in##_strings_ops,			\
96	.ct_owner       = THIS_MODULE,					\
97}
98
99#endif