// SPDX-License-Identifier: GPL-2.0-only
/*
 * finite state machine implementation
 *
 * Author       Karsten Keil <kkeil@novell.com>
 *
 * Thanks to    Jan den Ouden
 *              Fritz Elfert
 * Copyright 2008  by Karsten Keil <kkeil@novell.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/string.h>
#include "fsm.h"

#define FSM_TIMER_DEBUG 0

int
mISDN_FsmNew(struct Fsm *fsm,
             struct FsmNode *fnlist, int fncount)
{
        int i;

        fsm->jumpmatrix =
                kzalloc(array3_size(sizeof(FSMFNPTR), fsm->state_count,
                                    fsm->event_count),
                        GFP_KERNEL);
        if (fsm->jumpmatrix == NULL)
                return -ENOMEM;

        for (i = 0; i < fncount; i++)
                if ((fnlist[i].state >= fsm->state_count) ||
                    (fnlist[i].event >= fsm->event_count)) {
                        printk(KERN_ERR
                               "mISDN_FsmNew Error: %d st(%ld/%ld) ev(%ld/%ld)\n",
                               i, (long)fnlist[i].state, (long)fsm->state_count,
                               (long)fnlist[i].event, (long)fsm->event_count);
                } else
                        fsm->jumpmatrix[fsm->state_count * fnlist[i].event +
                                        fnlist[i].state] = (FSMFNPTR) fnlist[i].routine;
        return 0;
}
EXPORT_SYMBOL(mISDN_FsmNew);

void
mISDN_FsmFree(struct Fsm *fsm)
{
        kfree((void *) fsm->jumpmatrix);
}
EXPORT_SYMBOL(mISDN_FsmFree);

int
mISDN_FsmEvent(struct FsmInst *fi, int event, void *arg)
{
        FSMFNPTR r;

        if ((fi->state >= fi->fsm->state_count) ||
            (event >= fi->fsm->event_count)) {
                printk(KERN_ERR
                       "mISDN_FsmEvent Error st(%ld/%ld) ev(%d/%ld)\n",
                       (long)fi->state, (long)fi->fsm->state_count, event,
                       (long)fi->fsm->event_count);
                return 1;
        }
        r = fi->fsm->jumpmatrix[fi->fsm->state_count * event + fi->state];
        if (r) {
                if (fi->debug)
                        fi->printdebug(fi, "State %s Event %s",
                                       fi->fsm->strState[fi->state],
                                       fi->fsm->strEvent[event]);
                r(fi, event, arg);
                return 0;
        } else {
                if (fi->debug)
                        fi->printdebug(fi, "State %s Event %s no action",
                                       fi->fsm->strState[fi->state],
                                       fi->fsm->strEvent[event]);
                return 1;
        }
}
EXPORT_SYMBOL(mISDN_FsmEvent);

void
mISDN_FsmChangeState(struct FsmInst *fi, int newstate)
{
        fi->state = newstate;
        if (fi->debug)
                fi->printdebug(fi, "ChangeState %s",
                               fi->fsm->strState[newstate]);
}
EXPORT_SYMBOL(mISDN_FsmChangeState);

static void
FsmExpireTimer(struct timer_list *t)
{
        struct FsmTimer *ft = timer_container_of(ft, t, tl);
#if FSM_TIMER_DEBUG
        if (ft->fi->debug)
                ft->fi->printdebug(ft->fi, "FsmExpireTimer %lx", (long) ft);
#endif
        mISDN_FsmEvent(ft->fi, ft->event, ft->arg);
}

void
mISDN_FsmInitTimer(struct FsmInst *fi, struct FsmTimer *ft)
{
        ft->fi = fi;
#if FSM_TIMER_DEBUG
        if (ft->fi->debug)
                ft->fi->printdebug(ft->fi, "mISDN_FsmInitTimer %lx", (long) ft);
#endif
        timer_setup(&ft->tl, FsmExpireTimer, 0);
}
EXPORT_SYMBOL(mISDN_FsmInitTimer);

void
mISDN_FsmDelTimer(struct FsmTimer *ft, int where)
{
#if FSM_TIMER_DEBUG
        if (ft->fi->debug)
                ft->fi->printdebug(ft->fi, "mISDN_FsmDelTimer %lx %d",
                                   (long) ft, where);
#endif
        timer_delete(&ft->tl);
}
EXPORT_SYMBOL(mISDN_FsmDelTimer);

int
mISDN_FsmAddTimer(struct FsmTimer *ft,
                  int millisec, int event, void *arg, int where)
{

#if FSM_TIMER_DEBUG
        if (ft->fi->debug)
                ft->fi->printdebug(ft->fi, "mISDN_FsmAddTimer %lx %d %d",
                                   (long) ft, millisec, where);
#endif

        if (timer_pending(&ft->tl)) {
                if (ft->fi->debug) {
                        printk(KERN_WARNING
                               "mISDN_FsmAddTimer: timer already active!\n");
                        ft->fi->printdebug(ft->fi,
                                           "mISDN_FsmAddTimer already active!");
                }
                return -1;
        }
        ft->event = event;
        ft->arg = arg;
        ft->tl.expires = jiffies + (millisec * HZ) / 1000;
        add_timer(&ft->tl);
        return 0;
}
EXPORT_SYMBOL(mISDN_FsmAddTimer);

void
mISDN_FsmRestartTimer(struct FsmTimer *ft,
                      int millisec, int event, void *arg, int where)
{

#if FSM_TIMER_DEBUG
        if (ft->fi->debug)
                ft->fi->printdebug(ft->fi, "mISDN_FsmRestartTimer %lx %d %d",
                                   (long) ft, millisec, where);
#endif

        if (timer_pending(&ft->tl))
                timer_delete(&ft->tl);
        ft->event = event;
        ft->arg = arg;
        ft->tl.expires = jiffies + (millisec * HZ) / 1000;
        add_timer(&ft->tl);
}
EXPORT_SYMBOL(mISDN_FsmRestartTimer);