summaryrefslogtreecommitdiffstats
path: root/drivers/net/skfp/hwt.c
blob: e6baa53307c7aa5ddc74641fd0733809963526fd (plain)
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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/******************************************************************************
 *
 *	(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.
 *
 ******************************************************************************/

/*
 * Timer Driver for FBI board (timer chip 82C54)
 */

/*
 * Modifications:
 *
 *	28-Jun-1994 sw	Edit v1.6.
 *			MCA: Added support for the SK-NET FDDI-FM2 adapter. The
 *			 following functions have been added(+) or modified(*):
 *			 hwt_start(*), hwt_stop(*), hwt_restart(*), hwt_read(*)
 */

#include "h/types.h"
#include "h/fddi.h"
#include "h/smc.h"

#ifndef	lint
static const char ID_sccs[] = "@(#)hwt.c	1.13 97/04/23 (C) SK " ;
#endif

/*
 * Prototypes of local functions.
 */
/* 28-Jun-1994 sw - Note: hwt_restart() is also used in module 'drvfbi.c'. */
/*static void hwt_restart() ; */

/************************
 *
 *	hwt_start
 *
 *	Start hardware timer (clock ticks are 16us).
 *
 *	void hwt_start(
 *		struct s_smc *smc,
 *		u_long time) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 *
 *	time - The time in units of 16us to load the timer with.
 * Out
 *	Nothing.
 *
 ************************/
#define	HWT_MAX	(65000)

void hwt_start(struct s_smc *smc, u_long time)
{
	u_short	cnt ;

	if (time > HWT_MAX)
		time = HWT_MAX ;

	smc->hw.t_start = time ;
	smc->hw.t_stop = 0L ;

	cnt = (u_short)time ;
	/*
	 * if time < 16 us
	 *	time = 16 us
	 */
	if (!cnt)
		cnt++ ;

	outpd(ADDR(B2_TI_INI), (u_long) cnt * 200) ;	/* Load timer value. */
	outpw(ADDR(B2_TI_CRTL), TIM_START) ;		/* Start timer. */

	smc->hw.timer_activ = TRUE ;
}

/************************
 *
 *	hwt_stop
 *
 *	Stop hardware timer.
 *
 *	void hwt_stop(
 *		struct s_smc *smc) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 * Out
 *	Nothing.
 *
 ************************/
void hwt_stop(struct s_smc *smc)
{
	outpw(ADDR(B2_TI_CRTL), TIM_STOP) ;
	outpw(ADDR(B2_TI_CRTL), TIM_CL_IRQ) ;

	smc->hw.timer_activ = FALSE ;
}

/************************
 *
 *	hwt_init
 *
 *	Initialize hardware timer.
 *
 *	void hwt_init(
 *		struct s_smc *smc) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 * Out
 *	Nothing.
 *
 ************************/
void hwt_init(struct s_smc *smc)
{
	smc->hw.t_start = 0 ;
	smc->hw.t_stop	= 0 ;
	smc->hw.timer_activ = FALSE ;

	hwt_restart(smc) ;
}

/************************
 *
 *	hwt_restart
 *
 *	Clear timer interrupt.
 *
 *	void hwt_restart(
 *		struct s_smc *smc) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 * Out
 *	Nothing.
 *
 ************************/
void hwt_restart(struct s_smc *smc)
{
	hwt_stop(smc) ;
}

/************************
 *
 *	hwt_read
 *
 *	Stop hardware timer and read time elapsed since last start.
 *
 *	u_long hwt_read(smc) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 * Out
 *	The elapsed time since last start in units of 16us.
 *
 ************************/
u_long hwt_read(struct s_smc *smc)
{
	u_short	tr ;
	u_long	is ;

	if (smc->hw.timer_activ) {
		hwt_stop(smc) ;
		tr = (u_short)((inpd(ADDR(B2_TI_VAL))/200) & 0xffff) ;

		is = GET_ISR() ;
		/* Check if timer expired (or wraparound). */
		if ((tr > smc->hw.t_start) || (is & IS_TIMINT)) {
			hwt_restart(smc) ;
			smc->hw.t_stop = smc->hw.t_start ;
		}
		else
			smc->hw.t_stop = smc->hw.t_start - tr ;
	}
	return smc->hw.t_stop;
}

#ifdef	PCI
/************************
 *
 *	hwt_quick_read
 *
 *	Stop hardware timer and read timer value and start the timer again.
 *
 *	u_long hwt_read(smc) ;
 * In
 *	smc - A pointer to the SMT Context structure.
 * Out
 *	current timer value in units of 80ns.
 *
 ************************/
u_long hwt_quick_read(struct s_smc *smc)
{
	u_long interval ;
	u_long time ;

	interval = inpd(ADDR(B2_TI_INI)) ;
	outpw(ADDR(B2_TI_CRTL), TIM_STOP) ;
	time = inpd(ADDR(B2_TI_VAL)) ;
	outpd(ADDR(B2_TI_INI),time) ;
	outpw(ADDR(B2_TI_CRTL), TIM_START) ;
	outpd(ADDR(B2_TI_INI),interval) ;

	return time;
}

/************************
 *
 *	hwt_wait_time(smc,start,duration)
 *
 *	This function returnes after the amount of time is elapsed
 *	since the start time.
 * 
 * para	start		start time
 *	duration	time to wait
 *
 * NOTE: The fuction will return immediately, if the timer is not 
 *	 started
 ************************/
void hwt_wait_time(struct s_smc *smc, u_long start, long int duration)
{
	long	diff ;
	long	interval ;
	int	wrapped ;

	/*
	 * check if timer is running
	 */
	if (smc->hw.timer_activ == FALSE ||
		hwt_quick_read(smc) == hwt_quick_read(smc)) {
		return ;
	}

	interval = inpd(ADDR(B2_TI_INI)) ;
	if (interval > duration) {
		do {
			diff = (long)(start - hwt_quick_read(smc)) ;
			if (diff < 0) {
				diff += interval ;
			}
		} while (diff <= duration) ;
	}
	else {
		diff = interval ;
		wrapped = 0 ;
		do {
			if (!wrapped) {
				if (hwt_quick_read(smc) >= start) {
					diff += interval ;
					wrapped = 1 ;
				}
			}
			else {
				if (hwt_quick_read(smc) < start) {
					wrapped = 0 ;
				}
			}
		} while (diff <= duration) ;
	}
}
#endif