Subversion Repositories HelenOS

/*
 * 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);
extern void chardev_push_character(chardev_t *chardev, __u8 ch);

#endif /* __CHARDEV_H__ */