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 static void timer_done(struct s_smc *smc, int restart);
22
smt_timer_init(struct s_smc * smc)23 void smt_timer_init(struct s_smc *smc)
24 {
25 smc->t.st_queue = NULL;
26 smc->t.st_fast.tm_active = FALSE ;
27 smc->t.st_fast.tm_next = NULL;
28 hwt_init(smc) ;
29 }
30
smt_timer_stop(struct s_smc * smc,struct smt_timer * timer)31 void smt_timer_stop(struct s_smc *smc, struct smt_timer *timer)
32 {
33 struct smt_timer **prev ;
34 struct smt_timer *tm ;
35
36 /*
37 * remove timer from queue
38 */
39 timer->tm_active = FALSE ;
40 if (smc->t.st_queue == timer && !timer->tm_next) {
41 hwt_stop(smc) ;
42 }
43 for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
44 if (tm == timer) {
45 *prev = tm->tm_next ;
46 if (tm->tm_next) {
47 tm->tm_next->tm_delta += tm->tm_delta ;
48 }
49 return ;
50 }
51 }
52 }
53
smt_timer_start(struct s_smc * smc,struct smt_timer * timer,u_long time,u_long token)54 void smt_timer_start(struct s_smc *smc, struct smt_timer *timer, u_long time,
55 u_long token)
56 {
57 struct smt_timer **prev ;
58 struct smt_timer *tm ;
59 u_long delta = 0 ;
60
61 time /= 16 ; /* input is uS, clock ticks are 16uS */
62 if (!time)
63 time = 1 ;
64 smt_timer_stop(smc,timer) ;
65 timer->tm_smc = smc ;
66 timer->tm_token = token ;
67 timer->tm_active = TRUE ;
68 if (!smc->t.st_queue) {
69 smc->t.st_queue = timer ;
70 timer->tm_next = NULL;
71 timer->tm_delta = time ;
72 hwt_start(smc,time) ;
73 return ;
74 }
75 /*
76 * timer correction
77 */
78 timer_done(smc,0) ;
79
80 /*
81 * find position in queue
82 */
83 delta = 0 ;
84 for (prev = &smc->t.st_queue ; (tm = *prev) ; prev = &tm->tm_next ) {
85 if (delta + tm->tm_delta > time) {
86 break ;
87 }
88 delta += tm->tm_delta ;
89 }
90 /* insert in queue */
91 *prev = timer ;
92 timer->tm_next = tm ;
93 timer->tm_delta = time - delta ;
94 if (tm)
95 tm->tm_delta -= timer->tm_delta ;
96 /*
97 * start new with first
98 */
99 hwt_start(smc,smc->t.st_queue->tm_delta) ;
100 }
101
smt_force_irq(struct s_smc * smc)102 void smt_force_irq(struct s_smc *smc)
103 {
104 smt_timer_start(smc,&smc->t.st_fast,32L, EV_TOKEN(EVENT_SMT,SM_FAST));
105 }
106
smt_timer_done(struct s_smc * smc)107 void smt_timer_done(struct s_smc *smc)
108 {
109 timer_done(smc,1) ;
110 }
111
timer_done(struct s_smc * smc,int restart)112 static void timer_done(struct s_smc *smc, int restart)
113 {
114 u_long delta ;
115 struct smt_timer *tm ;
116 struct smt_timer *next ;
117 struct smt_timer **last ;
118 int done = 0 ;
119
120 delta = hwt_read(smc) ;
121 last = &smc->t.st_queue ;
122 tm = smc->t.st_queue ;
123 while (tm && !done) {
124 if (delta >= tm->tm_delta) {
125 tm->tm_active = FALSE ;
126 delta -= tm->tm_delta ;
127 last = &tm->tm_next ;
128 tm = tm->tm_next ;
129 }
130 else {
131 tm->tm_delta -= delta ;
132 delta = 0 ;
133 done = 1 ;
134 }
135 }
136 *last = NULL;
137 next = smc->t.st_queue ;
138 smc->t.st_queue = tm ;
139
140 for ( tm = next ; tm ; tm = next) {
141 next = tm->tm_next ;
142 timer_event(smc,tm->tm_token) ;
143 }
144
145 if (restart && smc->t.st_queue)
146 hwt_start(smc,smc->t.st_queue->tm_delta) ;
147 }
148
149