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 * Timer Driver for FBI board (timer chip 82C54)
15 */
16
17 /*
18 * Modifications:
19 *
20 * 28-Jun-1994 sw Edit v1.6.
21 * MCA: Added support for the SK-NET FDDI-FM2 adapter. The
22 * following functions have been added(+) or modified(*):
23 * hwt_start(*), hwt_stop(*), hwt_restart(*), hwt_read(*)
24 */
25
26 #include "h/types.h"
27 #include "h/fddi.h"
28 #include "h/smc.h"
29
30 #ifndef lint
31 static const char ID_sccs[] = "@(#)hwt.c 1.13 97/04/23 (C) SK " ;
32 #endif
33
34 /*
35 * Prototypes of local functions.
36 */
37 /* 28-Jun-1994 sw - Note: hwt_restart() is also used in module 'drvfbi.c'. */
38 /*static void hwt_restart() ; */
39
40 /************************
41 *
42 * hwt_start
43 *
44 * Start hardware timer (clock ticks are 16us).
45 *
46 * void hwt_start(
47 * struct s_smc *smc,
48 * u_long time) ;
49 * In
50 * smc - A pointer to the SMT Context structure.
51 *
52 * time - The time in units of 16us to load the timer with.
53 * Out
54 * Nothing.
55 *
56 ************************/
57 #define HWT_MAX (65000)
58
hwt_start(struct s_smc * smc,u_long time)59 void hwt_start(struct s_smc *smc, u_long time)
60 {
61 u_short cnt ;
62
63 if (time > HWT_MAX)
64 time = HWT_MAX ;
65
66 smc->hw.t_start = time ;
67 smc->hw.t_stop = 0L ;
68
69 cnt = (u_short)time ;
70 /*
71 * if time < 16 us
72 * time = 16 us
73 */
74 if (!cnt)
75 cnt++ ;
76
77 outpd(ADDR(B2_TI_INI), (u_long) cnt * 200) ; /* Load timer value. */
78 outpw(ADDR(B2_TI_CRTL), TIM_START) ; /* Start timer. */
79
80 smc->hw.timer_activ = TRUE ;
81 }
82
83 /************************
84 *
85 * hwt_stop
86 *
87 * Stop hardware timer.
88 *
89 * void hwt_stop(
90 * struct s_smc *smc) ;
91 * In
92 * smc - A pointer to the SMT Context structure.
93 * Out
94 * Nothing.
95 *
96 ************************/
hwt_stop(struct s_smc * smc)97 void hwt_stop(struct s_smc *smc)
98 {
99 outpw(ADDR(B2_TI_CRTL), TIM_STOP) ;
100 outpw(ADDR(B2_TI_CRTL), TIM_CL_IRQ) ;
101
102 smc->hw.timer_activ = FALSE ;
103 }
104
105 /************************
106 *
107 * hwt_init
108 *
109 * Initialize hardware timer.
110 *
111 * void hwt_init(
112 * struct s_smc *smc) ;
113 * In
114 * smc - A pointer to the SMT Context structure.
115 * Out
116 * Nothing.
117 *
118 ************************/
hwt_init(struct s_smc * smc)119 void hwt_init(struct s_smc *smc)
120 {
121 smc->hw.t_start = 0 ;
122 smc->hw.t_stop = 0 ;
123 smc->hw.timer_activ = FALSE ;
124
125 hwt_restart(smc) ;
126 }
127
128 /************************
129 *
130 * hwt_restart
131 *
132 * Clear timer interrupt.
133 *
134 * void hwt_restart(
135 * struct s_smc *smc) ;
136 * In
137 * smc - A pointer to the SMT Context structure.
138 * Out
139 * Nothing.
140 *
141 ************************/
hwt_restart(struct s_smc * smc)142 void hwt_restart(struct s_smc *smc)
143 {
144 hwt_stop(smc) ;
145 }
146
147 /************************
148 *
149 * hwt_read
150 *
151 * Stop hardware timer and read time elapsed since last start.
152 *
153 * u_long hwt_read(smc) ;
154 * In
155 * smc - A pointer to the SMT Context structure.
156 * Out
157 * The elapsed time since last start in units of 16us.
158 *
159 ************************/
hwt_read(struct s_smc * smc)160 u_long hwt_read(struct s_smc *smc)
161 {
162 u_short tr ;
163 u_long is ;
164
165 if (smc->hw.timer_activ) {
166 hwt_stop(smc) ;
167 tr = (u_short)((inpd(ADDR(B2_TI_VAL))/200) & 0xffff) ;
168
169 is = GET_ISR() ;
170 /* Check if timer expired (or wraparound). */
171 if ((tr > smc->hw.t_start) || (is & IS_TIMINT)) {
172 hwt_restart(smc) ;
173 smc->hw.t_stop = smc->hw.t_start ;
174 }
175 else
176 smc->hw.t_stop = smc->hw.t_start - tr ;
177 }
178 return smc->hw.t_stop;
179 }
180
181 #ifdef PCI
182 /************************
183 *
184 * hwt_quick_read
185 *
186 * Stop hardware timer and read timer value and start the timer again.
187 *
188 * u_long hwt_read(smc) ;
189 * In
190 * smc - A pointer to the SMT Context structure.
191 * Out
192 * current timer value in units of 80ns.
193 *
194 ************************/
hwt_quick_read(struct s_smc * smc)195 u_long hwt_quick_read(struct s_smc *smc)
196 {
197 u_long interval ;
198 u_long time ;
199
200 interval = inpd(ADDR(B2_TI_INI)) ;
201 outpw(ADDR(B2_TI_CRTL), TIM_STOP) ;
202 time = inpd(ADDR(B2_TI_VAL)) ;
203 outpd(ADDR(B2_TI_INI),time) ;
204 outpw(ADDR(B2_TI_CRTL), TIM_START) ;
205 outpd(ADDR(B2_TI_INI),interval) ;
206
207 return time;
208 }
209
210 /************************
211 *
212 * hwt_wait_time(smc,start,duration)
213 *
214 * This function returnes after the amount of time is elapsed
215 * since the start time.
216 *
217 * para start start time
218 * duration time to wait
219 *
220 * NOTE: The function will return immediately, if the timer is not
221 * started
222 ************************/
hwt_wait_time(struct s_smc * smc,u_long start,long int duration)223 void hwt_wait_time(struct s_smc *smc, u_long start, long int duration)
224 {
225 long diff ;
226 long interval ;
227 int wrapped ;
228
229 /*
230 * check if timer is running
231 */
232 if (smc->hw.timer_activ == FALSE ||
233 hwt_quick_read(smc) == hwt_quick_read(smc)) {
234 return ;
235 }
236
237 interval = inpd(ADDR(B2_TI_INI)) ;
238 if (interval > duration) {
239 do {
240 diff = (long)(start - hwt_quick_read(smc)) ;
241 if (diff < 0) {
242 diff += interval ;
243 }
244 } while (diff <= duration) ;
245 }
246 else {
247 diff = interval ;
248 wrapped = 0 ;
249 do {
250 if (!wrapped) {
251 if (hwt_quick_read(smc) >= start) {
252 diff += interval ;
253 wrapped = 1 ;
254 }
255 }
256 else {
257 if (hwt_quick_read(smc) < start) {
258 wrapped = 0 ;
259 }
260 }
261 } while (diff <= duration) ;
262 }
263 }
264 #endif
265
266
