1/******************************************************************************
  2 *
  3 *	(C)Copyright 1998,1999 SysKonnect,
  4 *	a business unit of Schneider & Koch & Co. Datensysteme GmbH.
  5 *
  6 *	See the file "skfddi.c" for further information.
  7 *
  8 *	This program is free software; you can redistribute it and/or modify
  9 *	it under the terms of the GNU General Public License as published by
 10 *	the Free Software Foundation; either version 2 of the License, or
 11 *	(at your option) any later version.
 12 *
 13 *	The information in this file is provided "AS IS" without warranty.
 14 *
 15 ******************************************************************************/
 16
 17/*
 18	SMT timer
 19*/
 20
 21#include "h/types.h"
 22#include "h/fddi.h"
 23#include "h/smc.h"
 24
 25#ifndef	lint
 26static const char ID_sccs[] = "@(#)smttimer.c	2.4 97/08/04 (C) SK " ;
 27#endif
 28
 29static void timer_done(struct s_smc *smc, int restart);
 30
 31void smt_timer_init(struct s_smc *smc)
 32{
 33	smc->t.st_queue = NULL;
 34	smc->t.st_fast.tm_active = FALSE ;
 35	smc->t.st_fast.tm_next = NULL;
 36	hwt_init(smc) ;
 37}
 38
 39void smt_timer_stop(struct s_smc *smc, struct smt_timer *timer)
 40{
 41	struct smt_timer	**prev ;
 42	struct smt_timer	*tm ;
 43
 44	/*
 45	 * remove timer from queue
 46	 */
 47	timer->tm_active = FALSE ;
 48	if (smc->t.st_queue == timer && !timer->tm_next) {
 49		hwt_stop(smc) ;
 50	}
 51	for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
 52		if (tm == timer) {
 53			*prev = tm->tm_next ;
 54			if (tm->tm_next) {
 55				tm->tm_next->tm_delta += tm->tm_delta ;
 56			}
 57			return ;
 58		}
 59	}
 60}
 61
 62void smt_timer_start(struct s_smc *smc, struct smt_timer *timer, u_long time,
 63		     u_long token)
 64{
 65	struct smt_timer	**prev ;
 66	struct smt_timer	*tm ;
 67	u_long			delta = 0 ;
 68
 69	time /= 16 ;		/* input is uS, clock ticks are 16uS */
 70	if (!time)
 71		time = 1 ;
 72	smt_timer_stop(smc,timer) ;
 73	timer->tm_smc = smc ;
 74	timer->tm_token = token ;
 75	timer->tm_active = TRUE ;
 76	if (!smc->t.st_queue) {
 77		smc->t.st_queue = timer ;
 78		timer->tm_next = NULL;
 79		timer->tm_delta = time ;
 80		hwt_start(smc,time) ;
 81		return ;
 82	}
 83	/*
 84	 * timer correction
 85	 */
 86	timer_done(smc,0) ;
 87
 88	/*
 89	 * find position in queue
 90	 */
 91	delta = 0 ;
 92	for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
 93		if (delta + tm->tm_delta > time) {
 94			break ;
 95		}
 96		delta += tm->tm_delta ;
 97	}
 98	/* insert in queue */
 99	*prev = timer ;
100	timer->tm_next = tm ;
101	timer->tm_delta = time - delta ;
102	if (tm)
103		tm->tm_delta -= timer->tm_delta ;
104	/*
105	 * start new with first
106	 */
107	hwt_start(smc,smc->t.st_queue->tm_delta) ;
108}
109
110void smt_force_irq(struct s_smc *smc)
111{
112	smt_timer_start(smc,&smc->t.st_fast,32L, EV_TOKEN(EVENT_SMT,SM_FAST)); 
113}
114
115void smt_timer_done(struct s_smc *smc)
116{
117	timer_done(smc,1) ;
118}
119
120static void timer_done(struct s_smc *smc, int restart)
121{
122	u_long			delta ;
123	struct smt_timer	*tm ;
124	struct smt_timer	*next ;
125	struct smt_timer	**last ;
126	int			done = 0 ;
127
128	delta = hwt_read(smc) ;
129	last = &smc->t.st_queue ;
130	tm = smc->t.st_queue ;
131	while (tm && !done) {
132		if (delta >= tm->tm_delta) {
133			tm->tm_active = FALSE ;
134			delta -= tm->tm_delta ;
135			last = &tm->tm_next ;
136			tm = tm->tm_next ;
137		}
138		else {
139			tm->tm_delta -= delta ;
140			delta = 0 ;
141			done = 1 ;
142		}
143	}
144	*last = NULL;
145	next = smc->t.st_queue ;
146	smc->t.st_queue = tm ;
147
148	for ( tm = next ; tm ; tm = next) {
149		next = tm->tm_next ;
150		timer_event(smc,tm->tm_token) ;
151	}
152
153	if (restart && smc->t.st_queue)
154		hwt_start(smc,smc->t.st_queue->tm_delta) ;
155}
156