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/* fd.c -- Definition of functions and structures for

   peripheral to communicate with host through file descriptors

   Copyright (C) 2002 Richard Prescott <rip@step.polymtl.ca>

This file is part of OpenRISC 1000 Architectural Simulator.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#if HAVE_CONFIG_H

#include <config.h>

#endif

#include <sys/time.h>   /* struct timeval */

#include <sys/types.h>  /* fd_set */

#include <stdio.h>      /* perror */

#include <stdlib.h>     /* atoi */

#include <unistd.h>     /* read, write, select */

#if HAVE_MALLOC_H

#include <malloc.h>     /* calloc, free */

#endif

#include <string.h>     /* strchr */

#include <errno.h>      /* errno */

#include "channel.h"

#include "generic.h"

#include "fd.h"

static void * fd_init(const char * args)

{

        struct fd_channel * retval;

        retval = (struct fd_channel*)calloc(1, sizeof(struct fd_channel));

        if(!retval)

        {

                return NULL;

        }

        retval->fdin  = atoi(args);     /* so 0 if garbage */

                                        /* TODO: strtoul */

        args = strchr(args, ',');

        if(args)

        {

                retval->fdout  = atoi(args+1);

        }

        else

        {

                retval->fdout  = retval->fdin;

        }

        return (void*)retval;

}

int fd_read(void * data, char * buffer, int size)

{

        struct fd_channel * fds = (struct fd_channel *)data;

        struct timeval timeout = { 0, 0 };

        fd_set rfds;

        int retval;

        if(!fds)

        {

                errno = ENODEV;

                return -1;

        }

        FD_ZERO(&rfds);

        FD_SET(fds->fdin, &rfds);

        retval = select(fds->fdin+1, &rfds, NULL, NULL, &timeout);

        if(retval <= 0)

                return retval;

        return read(fds->fdin, buffer, size);

}

int fd_write(void * data, const char * buffer, int size)

{

        struct fd_channel * fds = (struct fd_channel *)data;

        if(fds)

        {

                return write(fds->fdout, buffer, size);

        }

        errno = ENODEV;

        return -1;

}

static int fd_isok(void * data)

{

        struct fd_channel * fds = (struct fd_channel *)data;

        if(fds)

        {

                return fds->fdout != -1 && fds->fdin != -1;

        }

        return 0;

}

static int fd_status_fd(int fd, char * str, int size)

{

        if(fd == -1)

                return snprintf(str, size, "closed");

        return snprintf(str, size, "opened(fd=%d)", fd);

}

char * fd_status(void * data)

{

        static char retval[256];

        int index = 0;

        struct fd_channel * fds = (struct fd_channel *)data;

        if(fds)

        {

                index += snprintf(retval + index, sizeof(retval) - index, "in ");

                index += fd_status_fd(fds->fdin, retval + index, sizeof(retval) - index);

                index += snprintf(retval + index, sizeof(retval) - index, "out ");

                index += fd_status_fd(fds->fdout, retval + index, sizeof(retval) - index);

        }

        else

        {

                snprintf(retval, sizeof(retval), "(null)");

        }

        return retval;

}

struct channel_ops fd_channel_ops =

{

        init:   fd_init,

        open:   generic_open,

        close:  generic_close,

        read:   fd_read,

        write:  fd_write,

        free:   generic_free,

        isok:   fd_isok,

        status: fd_status,

};

/*

 * Local variables:

 * c-file-style: "linux"

 * End:

 */