summaryrefslogtreecommitdiff
path: root/drivers/net/skfp/smttimer.c
blob: 531795e98c30d25f25c8f0c5c1aa0a259d67f5a7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/******************************************************************************
 *
 *	(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

static void timer_done(struct s_smc *smc, int restart);

void smt_timer_init(struct s_smc *smc)
{
	smc->t.st_queue = NULL;
	smc->t.st_fast.tm_active = FALSE ;
	smc->t.st_fast.tm_next = NULL;
	hwt_init(smc) ;
}

void smt_timer_stop(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(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 = NULL;
		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(struct s_smc *smc)
{
	smt_timer_start(smc,&smc->t.st_fast,32L, EV_TOKEN(EVENT_SMT,SM_FAST)); 
}

void smt_timer_done(struct s_smc *smc)
{
	timer_done(smc,1) ;
}

static void timer_done(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 = NULL;
	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) ;
}