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clock.c revision 1.9 
      1 /* $NetBSD: clock.c,v 1.9 2011/08/23 14:37:50 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.9 2011/08/23 14:37:50 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/proc.h>
     34 #include <sys/systm.h>
     35 #include <sys/device.h>
     36 #include <sys/timetc.h>
     37 #include <sys/time.h>
     38 
     39 #include <machine/mainbus.h>
     40 #include <machine/thunk.h>
     41 
     42 #include <dev/clock_subr.h>
     43 
     44 static int	clock_match(device_t, cfdata_t, void *);
     45 static void	clock_attach(device_t, device_t, void *);
     46 
     47 static void 	clock_intr(int);
     48 static u_int	clock_getcounter(struct timecounter *);
     49 
     50 static int	clock_todr_gettime(struct todr_chip_handle *, struct timeval *);
     51 
     52 typedef struct clock_softc {
     53 	device_t		sc_dev;
     54 	struct todr_chip_handle	sc_todr;
     55 } clock_softc_t;
     56 
     57 static struct timecounter clock_timecounter = {
     58 	clock_getcounter,	/* get_timecount */
     59 	0,			/* no poll_pps */
     60 	~0u,			/* counter_mask */
     61 	0,			/* frequency */
     62 	"CLOCK_MONOTONIC",	/* name */
     63 	-100,			/* quality */
     64 	NULL,			/* prev */
     65 	NULL,			/* next */
     66 };
     67 
     68 CFATTACH_DECL_NEW(clock, sizeof(clock_softc_t),
     69     clock_match, clock_attach, NULL, NULL);
     70 
     71 static int
     72 clock_match(device_t parent, cfdata_t match, void *opaque)
     73 {
     74 	struct thunkbus_attach_args *taa = opaque;
     75 
     76 	if (taa->taa_type != THUNKBUS_TYPE_CLOCK)
     77 		return 0;
     78 
     79 	return 1;
     80 }
     81 
     82 static void
     83 clock_attach(device_t parent, device_t self, void *opaque)
     84 {
     85 	clock_softc_t *sc = device_private(self);
     86 	struct itimerval itimer;
     87 	long tcres;
     88 
     89 	aprint_naive("\n");
     90 	aprint_normal("\n");
     91 
     92 	sc->sc_dev = self;
     93 
     94 	sc->sc_todr.todr_gettime = clock_todr_gettime;
     95 	todr_attach(&sc->sc_todr);
     96 
     97 	(void)signal(SIGALRM, clock_intr);
     98 
     99 	itimer.it_interval.tv_sec = 0;
    100 	itimer.it_interval.tv_usec = 10000;
    101 	itimer.it_value = itimer.it_interval;
    102 	thunk_setitimer(ITIMER_REAL, &itimer, NULL);
    103 
    104 	tcres = thunk_clock_getres_monotonic();
    105 	if (tcres > 0) {
    106 		clock_timecounter.tc_quality = 1000;
    107 		clock_timecounter.tc_frequency = 1000000000 / tcres;
    108 	}
    109 	tc_init(&clock_timecounter);
    110 }
    111 
    112 static void
    113 clock_intr(int notused)
    114 {
    115 	extern int usermode_x;
    116 	struct clockframe cf;
    117 
    118 	curcpu()->ci_idepth++;
    119 
    120 	hardclock(&cf);
    121 
    122 	curcpu()->ci_idepth--;
    123 }
    124 
    125 static u_int
    126 clock_getcounter(struct timecounter *tc)
    127 {
    128 	struct timespec ts;
    129 
    130 	thunk_clock_gettime(CLOCK_MONOTONIC, &ts);
    131 	return ts.tv_nsec;
    132 }
    133 
    134 static int
    135 clock_todr_gettime(struct todr_chip_handle *tch, struct timeval *tv)
    136 {
    137 	return thunk_gettimeofday(tv,  NULL);
    138 }
    139