blob: 531795e98c30d25f25c8f0c5c1aa0a259d67f5a7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/******************************************************************************
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