Quelle  gadget_configfs.h   Sprache: C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __GADGET_CONFIGFS__
#define __GADGET_CONFIGFS__

#include <linux/configfs.h>

#define GS_STRINGS_W(__struct, __name) \
static ssize_t __struct##_##__name##_store(struct config_item *item, \
  const char *page, size_t len)  \
{       \
 struct __struct *gs = to_##__struct(item); \
 int ret;     \
       \
 ret = usb_string_copy(page, &gs->__name); \
 if (ret)     \
  return ret;    \
 return len;     \
}

#define GS_STRINGS_R(__struct, __name) \
static ssize_t __struct##_##__name##_show(struct config_item *item, char *page) \
{ \
 struct __struct *gs = to_##__struct(item); \
 return sprintf(page, "%s\n", gs->__name ?: ""); \
}

#define GS_STRINGS_RW(struct_name, _name) \
 GS_STRINGS_R(struct_name, _name) \
 GS_STRINGS_W(struct_name, _name) \
 CONFIGFS_ATTR(struct_name##_, _name)

#define USB_CONFIG_STRING_RW_OPS(struct_in)    \
static struct configfs_item_operations struct_in##_langid_item_ops = { \
 .release                = struct_in##_attr_release,  \
};         \
         \
static const struct config_item_type struct_in##_langid_type = { \
 .ct_item_ops = &struct_in##_langid_item_ops,   \
 .ct_attrs = struct_in##_langid_attrs,   \
 .ct_owner = THIS_MODULE,     \
}

#define USB_CONFIG_STRINGS_LANG(struct_in, struct_member) \
 static struct config_group *struct_in##_strings_make(  \
   struct config_group *group,   \
   const char *name)    \
 {        \
 struct struct_member *gi;     \
 struct struct_in *gs;      \
 struct struct_in *new;      \
 int langs = 0;       \
 int ret;       \
         \
 new = kzalloc(sizeof(*new), GFP_KERNEL);   \
 if (!new)       \
  return ERR_PTR(-ENOMEM);    \
         \
 ret = check_user_usb_string(name, &new->stringtab_dev);  \
 if (ret)       \
  goto err;      \
 config_group_init_type_name(&new->group, name,   \
   &struct_in##_langid_type);   \
         \
 gi = container_of(group, struct struct_member, strings_group); \
 ret = -EEXIST;       \
 list_for_each_entry(gs, &gi->string_list, list) {  \
  if (gs->stringtab_dev.language == new->stringtab_dev.language) \
   goto err;     \
  langs++;      \
 }        \
 ret = -EOVERFLOW;      \
 if (langs >= MAX_USB_STRING_LANGS)    \
  goto err;      \
         \
 list_add_tail(&new->list, &gi->string_list);   \
 return &new->group;      \
err:         \
 kfree(new);       \
 return ERR_PTR(ret);      \
}         \
         \
static void struct_in##_strings_drop(     \
  struct config_group *group,    \
  struct config_item *item)    \
{         \
 config_item_put(item);      \
}         \
         \
static struct configfs_group_operations struct_in##_strings_ops = { \
 .make_group     = &struct_in##_strings_make,   \
 .drop_item      = &struct_in##_strings_drop,   \
};         \
         \
static const struct config_item_type struct_in##_strings_type = { \
 .ct_group_ops   = &struct_in##_strings_ops,   \
 .ct_owner       = THIS_MODULE,     \
}

#endif