/*
 * Copyright (C) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 __CHARDEV_H__
#define __CHARDEV_H__

#include <typedefs.h>
#include <arch/types.h>
#include <synch/waitq.h>
#include <synch/spinlock.h>

#define CHARDEV_BUFLEN 512

/* Character device operations interface. */
struct chardev_operations {
	void (* suspend)(chardev_t *);		/**< Suspend pushing characters. */
	void (* resume)(chardev_t *); 		/**< Resume pushing characters. */
	void (* write)(chardev_t *, char c);	/**< Write character to stream. */
	/** Read character directly from device, assume interrupts disabled */
	char (* read)(chardev_t *); 
};

typedef struct chardev_operations chardev_operations_t;

/** Character input device. */
struct chardev {
	char *name;
	
	waitq_t wq;
	SPINLOCK_DECLARE(lock);		/**< Protects everything below. */
	__u8 buffer[CHARDEV_BUFLEN];
	count_t counter;
	chardev_operations_t *op;	/**< Implementation of chardev operations. */
	index_t index;
	void *data;
};

extern void chardev_initialize(char *name,
			       chardev_t *chardev, 
			       chardev_operations_t *op);
void chardev_push_character(chardev_t *chardev, __u8 ch);

#endif /* __CHARDEV_H__ */