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/*
* Copyright (c) 2025 Ian Marco Moffett and L5 engineers
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _FS_DEVFS_H_
#define _FS_DEVFS_H_
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/limits.h>
#include <os/vnode.h>
/* Forward declarations */
struct devfs_node;
/*
* Represents an I/O buffer for device files
* on the system
*/
struct dev_iobuf {
void *buf;
size_t count;
};
/*
* Character device descriptor and hooks
*
* @read: Read n bytes from the char device
* @write: Write n bytes from the char device
*/
struct cdevsw {
ssize_t(*read)(struct devfs_node *dnp, struct dev_iobuf *iob, int flags);
ssize_t(*write)(struct devfs_node *dnp, struct dev_iobuf *iob, int flags);
};
/*
* Describes the device node types
*
* @DEVFS_NONE: No type
* @DEVFS_CDEV: Char device
*/
typedef enum {
DEVFS_NONE,
DEVFS_CDEV,
__DEVFS_NTYPE
} dev_type_t;
/*
* Represents a device filesystem node
*
* @name: Name of device node
* @type: Node type
* @cdev: Character device (if DEVFS_CDEV)
* @link: Queue link
*/
struct devfs_node {
char name[NAME_MAX];
dev_type_t type;
union {
struct cdevsw *cdev;
void *dev;
};
TAILQ_ENTRY(devfs_node) link;
};
/*
* Register a character device
*
* @name: Name of character device
* @type: Device type to use
* @cdev: Character device operations to use
* @flags: Optional flags
*
* Returns zero on success, otherwise a less than zero
* value on failure.
*/
int devfs_register(const char *name, dev_type_t type, void *devsw, int flags);
#endif /* !_FS_DEVFS_H_ */
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