1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /******************************************************************************
3 *
4 * (C)Copyright 1998,1999 SysKonnect,
5 * a business unit of Schneider & Koch & Co. Datensysteme GmbH.
6 *
7 * See the file "skfddi.c" for further information.
8 *
9 * The information in this file is provided "AS IS" without warranty.
10 *
11 ******************************************************************************/
12
13 /*
14 SMT timer
15 */
16
17 #include "h/types.h"
18 #include "h/fddi.h"
19 #include "h/smc.h"
20
21 #ifndef lint
22 static const char ID_sccs[] = "@(#)smttimer.c 2.4 97/08/04 (C) SK " ;
23 #endif
24
25 static void timer_done(struct s_smc *smc, int restart);
26
smt_timer_init(struct s_smc * smc)27 void smt_timer_init(struct s_smc *smc)
28 {
29 smc->t.st_queue = NULL;
30 smc->t.st_fast.tm_active = FALSE ;
31 smc->t.st_fast.tm_next = NULL;
32 hwt_init(smc) ;
33 }
34
smt_timer_stop(struct s_smc * smc,struct smt_timer * timer)35 void smt_timer_stop(struct s_smc *smc, struct smt_timer *timer)
36 {
37 struct smt_timer **prev ;
38 struct smt_timer *tm ;
39
40 /*
41 * remove timer from queue
42 */
43 timer->tm_active = FALSE ;
44 if (smc->t.st_queue == timer && !timer->tm_next) {
45 hwt_stop(smc) ;
46 }
47 for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
48 if (tm == timer) {
49 *prev = tm->tm_next ;
50 if (tm->tm_next) {
51 tm->tm_next->tm_delta += tm->tm_delta ;
52 }
53 return ;
54 }
55 }
56 }
57
smt_timer_start(struct s_smc * smc,struct smt_timer * timer,u_long time,u_long token)58 void smt_timer_start(struct s_smc *smc, struct smt_timer *timer, u_long time,
59 u_long token)
60 {
61 struct smt_timer **prev ;
62 struct smt_timer *tm ;
63 u_long delta = 0 ;
64
65 time /= 16 ; /* input is uS, clock ticks are 16uS */
66 if (!time)
67 time = 1 ;
68 smt_timer_stop(smc,timer) ;
69 timer->tm_smc = smc ;
70 timer->tm_token = token ;
71 timer->tm_active = TRUE ;
72 if (!smc->t.st_queue) {
73 smc->t.st_queue = timer ;
74 timer->tm_next = NULL;
75 timer->tm_delta = time ;
76 hwt_start(smc,time) ;
77 return ;
78 }
79 /*
80 * timer correction
81 */
82 timer_done(smc,0) ;
83
84 /*
85 * find position in queue
86 */
87 delta = 0 ;
88 for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
89 if (delta + tm->tm_delta > time) {
90 break ;
91 }
92 delta += tm->tm_delta ;
93 }
94 /* insert in queue */
95 *prev = timer ;
96 timer->tm_next = tm ;
97 timer->tm_delta = time - delta ;
98 if (tm)
99 tm->tm_delta -= timer->tm_delta ;
100 /*
101 * start new with first
102 */
103 hwt_start(smc,smc->t.st_queue->tm_delta) ;
104 }
105
smt_force_irq(struct s_smc * smc)106 void smt_force_irq(struct s_smc *smc)
107 {
108 smt_timer_start(smc,&smc->t.st_fast,32L, EV_TOKEN(EVENT_SMT,SM_FAST));
109 }
110
smt_timer_done(struct s_smc * smc)111 void smt_timer_done(struct s_smc *smc)
112 {
113 timer_done(smc,1) ;
114 }
115
timer_done(struct s_smc * smc,int restart)116 static void timer_done(struct s_smc *smc, int restart)
117 {
118 u_long delta ;
119 struct smt_timer *tm ;
120 struct smt_timer *next ;
121 struct smt_timer **last ;
122 int done = 0 ;
123
124 delta = hwt_read(smc) ;
125 last = &smc->t.st_queue ;
126 tm = smc->t.st_queue ;
127 while (tm && !done) {
128 if (delta >= tm->tm_delta) {
129 tm->tm_active = FALSE ;
130 delta -= tm->tm_delta ;
131 last = &tm->tm_next ;
132 tm = tm->tm_next ;
133 }
134 else {
135 tm->tm_delta -= delta ;
136 delta = 0 ;
137 done = 1 ;
138 }
139 }
140 *last = NULL;
141 next = smc->t.st_queue ;
142 smc->t.st_queue = tm ;
143
144 for ( tm = next ; tm ; tm = next) {
145 next = tm->tm_next ;
146 timer_event(smc,tm->tm_token) ;
147 }
148
149 if (restart && smc->t.st_queue)
150 hwt_start(smc,smc->t.st_queue->tm_delta) ;
151 }
152
153
