Viewing file:  smttimer.c (3.45 KB) -rw-r--r--
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/******************************************************************************
*
* (C)Copyright 1998,1999 SysKonnect,
* a business unit of Schneider & Koch & Co. Datensysteme GmbH.
*
* See the file "skfddi.c" for further information.
*
* 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.
*
* The information in this file is provided "AS IS" without warranty.
*
******************************************************************************/
/*
SMT timer
*/
#include "h/types.h"
#include "h/fddi.h"
#include "h/smc.h"
#ifndef lint
static const char ID_sccs[] = "@(#)smttimer.c 2.4 97/08/04 (C) SK " ;
#endif
/*
* external function declarations
*/
extern u_long hwt_read() ;
extern void hwt_stop() ;
extern void hwt_start() ;
static void timer_done() ;
void smt_timer_init(smc)
struct s_smc *smc ;
{
smc->t.st_queue = 0 ;
smc->t.st_fast.tm_active = FALSE ;
smc->t.st_fast.tm_next = 0 ;
hwt_init(smc) ;
}
void smt_timer_stop(smc,timer)
struct s_smc *smc ;
struct smt_timer *timer ;
{
struct smt_timer **prev ;
struct smt_timer *tm ;
/*
* remove timer from queue
*/
timer->tm_active = FALSE ;
if (smc->t.st_queue == timer && !timer->tm_next) {
hwt_stop(smc) ;
}
for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
if (tm == timer) {
*prev = tm->tm_next ;
if (tm->tm_next) {
tm->tm_next->tm_delta += tm->tm_delta ;
}
return ;
}
}
}
void smt_timer_start(smc,timer,time,token)
struct s_smc *smc ;
struct smt_timer *timer ;
u_long time ;
u_long token ;
{
struct smt_timer **prev ;
struct smt_timer *tm ;
u_long delta = 0 ;
time /= 16 ; /* input is uS, clock ticks are 16uS */
if (!time)
time = 1 ;
smt_timer_stop(smc,timer) ;
timer->tm_smc = smc ;
timer->tm_token = token ;
timer->tm_active = TRUE ;
if (!smc->t.st_queue) {
smc->t.st_queue = timer ;
timer->tm_next = 0 ;
timer->tm_delta = time ;
hwt_start(smc,time) ;
return ;
}
/*
* timer correction
*/
timer_done(smc,0) ;
/*
* find position in queue
*/
delta = 0 ;
for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
if (delta + tm->tm_delta > time) {
break ;
}
delta += tm->tm_delta ;
}
/* insert in queue */
*prev = timer ;
timer->tm_next = tm ;
timer->tm_delta = time - delta ;
if (tm)
tm->tm_delta -= timer->tm_delta ;
/*
* start new with first
*/
hwt_start(smc,smc->t.st_queue->tm_delta) ;
}
void smt_force_irq(smc)
struct s_smc *smc ;
{
smt_timer_start(smc,&smc->t.st_fast,32L, EV_TOKEN(EVENT_SMT,SM_FAST));
}
void smt_timer_done(smc)
struct s_smc *smc ;
{
timer_done(smc,1) ;
}
static void timer_done(smc,restart)
struct s_smc *smc ;
int restart ;
{
u_long delta ;
struct smt_timer *tm ;
struct smt_timer *next ;
struct smt_timer **last ;
int done = 0 ;
delta = hwt_read(smc) ;
last = &smc->t.st_queue ;
tm = smc->t.st_queue ;
while (tm && !done) {
if (delta >= tm->tm_delta) {
tm->tm_active = FALSE ;
delta -= tm->tm_delta ;
last = &tm->tm_next ;
tm = tm->tm_next ;
}
else {
tm->tm_delta -= delta ;
delta = 0 ;
done = 1 ;
}
}
*last = 0 ;
next = smc->t.st_queue ;
smc->t.st_queue = tm ;
for ( tm = next ; tm ; tm = next) {
next = tm->tm_next ;
timer_event(smc,tm->tm_token) ;
}
if (restart && smc->t.st_queue)
hwt_start(smc,smc->t.st_queue->tm_delta) ;
}
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