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
157