include/linux/usb/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 int check_user_usb_string(const char *name,
   8                 struct usb_gadget_strings *stringtab_dev);
   9
  10 #define GS_STRINGS_W(__struct, __name)  \
  11 static ssize_t __struct##_##__name##_store(struct config_item *item, \
  12                 const char *page, size_t len)           \
  13 {                                                       \
  14         struct __struct *gs = to_##__struct(item);      \
  15         int ret;                                        \
  16                                                         \
  17         ret = usb_string_copy(page, &gs->__name);       \
  18         if (ret)                                        \
  19                 return ret;                             \
  20         return len;                                     \
  21 }
  22
  23 #define GS_STRINGS_R(__struct, __name)  \
  24 static ssize_t __struct##_##__name##_show(struct config_item *item, char *page) \
  25 {       \
  26         struct __struct *gs = to_##__struct(item);      \
  27         return sprintf(page, "%s\n", gs->__name ?: ""); \
  28 }
  29
  30 #define GS_STRINGS_RW(struct_name, _name)       \
  31         GS_STRINGS_R(struct_name, _name)        \
  32         GS_STRINGS_W(struct_name, _name)        \
  33         CONFIGFS_ATTR(struct_name##_, _name)
  34
  35 #define USB_CONFIG_STRING_RW_OPS(struct_in)                             \
  36 static struct configfs_item_operations struct_in##_langid_item_ops = {  \
  37         .release                = struct_in##_attr_release,             \
  38 };                                                                      \
  39                                                                         \
  40 static struct config_item_type struct_in##_langid_type = {              \
  41         .ct_item_ops    = &struct_in##_langid_item_ops,                 \
  42         .ct_attrs       = struct_in##_langid_attrs,                     \
  43         .ct_owner       = THIS_MODULE,                                  \
  44 }
  45
  46 #define USB_CONFIG_STRINGS_LANG(struct_in, struct_member)       \
  47         static struct config_group *struct_in##_strings_make(           \
  48                         struct config_group *group,                     \
  49                         const char *name)                               \
  50         {                                                               \
  51         struct struct_member *gi;                                       \
  52         struct struct_in *gs;                                           \
  53         struct struct_in *new;                                          \
  54         int langs = 0;                                                  \
  55         int ret;                                                        \
  56                                                                         \
  57         new = kzalloc(sizeof(*new), GFP_KERNEL);                        \
  58         if (!new)                                                       \
  59                 return ERR_PTR(-ENOMEM);                                \
  60                                                                         \
  61         ret = check_user_usb_string(name, &new->stringtab_dev);         \
  62         if (ret)                                                        \
  63                 goto err;                                               \
  64         config_group_init_type_name(&new->group, name,                  \
  65                         &struct_in##_langid_type);                      \
  66                                                                         \
  67         gi = container_of(group, struct struct_member, strings_group);  \
  68         ret = -EEXIST;                                                  \
  69         list_for_each_entry(gs, &gi->string_list, list) {               \
  70                 if (gs->stringtab_dev.language == new->stringtab_dev.language) \
  71                         goto err;                                       \
  72                 langs++;                                                \
  73         }                                                               \
  74         ret = -EOVERFLOW;                                               \
  75         if (langs >= MAX_USB_STRING_LANGS)                              \
  76                 goto err;                                               \
  77                                                                         \
  78         list_add_tail(&new->list, &gi->string_list);                    \
  79         return &new->group;                                             \
  80 err:                                                                    \
  81         kfree(new);                                                     \
  82         return ERR_PTR(ret);                                            \
  83 }                                                                       \
  84                                                                         \
  85 static void struct_in##_strings_drop(                                   \
  86                 struct config_group *group,                             \
  87                 struct config_item *item)                               \
  88 {                                                                       \
  89         config_item_put(item);                                          \
  90 }                                                                       \
  91                                                                         \
  92 static struct configfs_group_operations struct_in##_strings_ops = {     \
  93         .make_group     = &struct_in##_strings_make,                    \
  94         .drop_item      = &struct_in##_strings_drop,                    \
  95 };                                                                      \
  96                                                                         \
  97 static struct config_item_type struct_in##_strings_type = {             \
  98         .ct_group_ops   = &struct_in##_strings_ops,                     \
  99         .ct_owner       = THIS_MODULE,                                  \
 100 }
 101
 102 #endif