/* $NetBSD: wsemulconf.c,v 1.8 2010/02/02 16:18:29 drochner Exp $ */

/*
* Copyright (c) 1996, 1997 Christopher G. Demetriou.  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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by Christopher G. Demetriou
*      for the NetBSD Project.
* 4. 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.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: wsemulconf.c,v 1.8 2010/02/02 16:18:29 drochner Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsdisplayvar.h>
#include <dev/wscons/wsksymvar.h>
#include <dev/wscons/wsemulvar.h>               /* pulls in opt_wsemul.h */
#include <dev/wscons/wscons_callbacks.h>

struct wsemulentry {
       const struct wsemul_ops *ops;
       int usecnt;
       LIST_ENTRY(wsemulentry) next;
};
static LIST_HEAD(, wsemulentry) wsemuls = LIST_HEAD_INITIALIZER(&wsemuls);

static const struct wsemul_ops *wsemul_conf[] = {
#ifdef WSEMUL_SUN
       &wsemul_sun_ops,
#endif
#ifdef WSEMUL_VT100
       &wsemul_vt100_ops,
#endif
#ifndef WSEMUL_NO_DUMB
       &wsemul_dumb_ops,
#endif
       NULL
};

const struct wsemul_ops *
wsemul_pick(const char *name)
{
       const struct wsemul_ops **ops;
       struct wsemulentry *wep;

       if (name == NULL) {
               /* default */
#ifdef WSEMUL_DEFAULT
               name = WSEMUL_DEFAULT;
#else
               return (wsemul_conf[0]);
#endif
       }

       LIST_FOREACH(wep, &wsemuls, next)
               if (!strcmp(name, wep->ops->name)) {
                       wep->usecnt++;
                       return wep->ops;
               }

       for (ops = &wsemul_conf[0]; *ops != NULL; ops++)
               if (strcmp(name, (*ops)->name) == 0)
                       break;

       return (*ops);
}

void
wsemul_drop(const struct wsemul_ops *ops)
{
       struct wsemulentry *wep;

       LIST_FOREACH(wep, &wsemuls, next)
               if (ops == wep->ops) {
                       wep->usecnt--;
                       return;
               }
}

int
wsemul_add(const struct wsemul_ops *ops)
{
       struct wsemulentry *wep;

       wep = malloc(sizeof (struct wsemulentry), M_DEVBUF, M_WAITOK);
       wep->ops = ops;
       wep->usecnt = 0;
       LIST_INSERT_HEAD(&wsemuls, wep, next);
       return 0;
}

int
wsemul_remove(const struct wsemul_ops *ops)
{
       struct wsemulentry *wep;

       LIST_FOREACH(wep, &wsemuls, next) {
               if (ops == wep->ops) {
                       if (wep->usecnt)
                               return EBUSY;
                       LIST_REMOVE(wep, next);
                       return 0;
               }
       }
       return ENOENT;
}