fddi/skfp/hwt.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
14  * Timer Driver for FBI board (timer chip 82C54)
20  *	28-Jun-1994 sw	Edit v1.6.
21  *			MCA: Added support for the SK-NET FDDI-FM2 adapter. The
35  * Prototypes of local functions.
37 /* 28-Jun-1994 sw - Note: hwt_restart() is also used in module 'drvfbi.c'. */
44  *	Start hardware timer (clock ticks are 16us).
50  *	smc - A pointer to the SMT Context structure.
52  *	time - The time in units of 16us to load the timer with.
66 	smc->hw.t_start = time ;  in hwt_start()
67 	smc->hw.t_stop = 0L ;  in hwt_start()
77 	outpd(ADDR(B2_TI_INI), (u_long) cnt * 200) ;	/* Load timer value. */  in hwt_start()
78 	outpw(ADDR(B2_TI_CRTL), TIM_START) ;		/* Start timer. */  in hwt_start()
80 	smc->hw.timer_activ = TRUE ;  in hwt_start()
87  *	Stop hardware timer.
92  *	smc - A pointer to the SMT Context structure.
102 	smc->hw.timer_activ = FALSE ;  in hwt_stop()
109  *	Initialize hardware timer.
114  *	smc - A pointer to the SMT Context structure.
121 	smc->hw.t_start = 0 ;  in hwt_init()
122 	smc->hw.t_stop	= 0 ;  in hwt_init()
123 	smc->hw.timer_activ = FALSE ;  in hwt_init()
132  *	Clear timer interrupt.
137  *	smc - A pointer to the SMT Context structure.
151  *	Stop hardware timer and read time elapsed since last start.
155  *	smc - A pointer to the SMT Context structure.
165 	if (smc->hw.timer_activ) {  in hwt_read()
170 		/* Check if timer expired (or wraparound). */  in hwt_read()
171 		if ((tr > smc->hw.t_start) || (is & IS_TIMINT)) {  in hwt_read()
173 			smc->hw.t_stop = smc->hw.t_start ;  in hwt_read()
176 			smc->hw.t_stop = smc->hw.t_start - tr ;  in hwt_read()
178 	return smc->hw.t_stop;  in hwt_read()
186  *	Stop hardware timer and read timer value and start the timer again.
190  *	smc - A pointer to the SMT Context structure.
192  *	current timer value in units of 80ns.
220  * NOTE: The function will return immediately, if the timer is not
230 	 * check if timer is running  in hwt_wait_time()
232 	if (smc->hw.timer_activ == FALSE ||  in hwt_wait_time()
240 			diff = (long)(start - hwt_quick_read(smc)) ;  in hwt_wait_time()