NetBSD/sys/dev/ic/acpipmtimer.c
2007-08-27 06:18:55 +00:00

94 lines
1.8 KiB
C

/* $NetBSD: acpipmtimer.c,v 1.3 2007/08/27 06:18:55 xtraeme Exp $ */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: acpipmtimer.c,v 1.3 2007/08/27 06:18:55 xtraeme Exp $");
#include <sys/types.h>
#ifdef __HAVE_TIMECOUNTER
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <machine/bus.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <dev/ic/acpipmtimer.h>
#define ACPI_PM_TIMER_FREQUENCY 3579545
struct hwtc {
struct timecounter tc;
bus_space_tag_t t;
bus_space_handle_t h;
bus_size_t off;
};
static u_int acpihwtimer_read_safe(struct timecounter *);
static u_int acpihwtimer_read_fast(struct timecounter *);
int
acpipmtimer_attach(struct device *dev,
bus_space_tag_t t, bus_space_handle_t h, bus_size_t off,
int flags)
{
struct hwtc *tc;
tc = malloc(sizeof(struct hwtc), M_DEVBUF, M_WAITOK|M_ZERO);
if (!tc)
return (-1);
tc->tc.tc_name = dev->dv_xname;
tc->tc.tc_frequency = ACPI_PM_TIMER_FREQUENCY;
if (flags & ACPIPMT_32BIT)
tc->tc.tc_counter_mask = 0xffffffff;
else
tc->tc.tc_counter_mask = 0x00ffffff;
if (flags & ACPIPMT_BADLATCH) {
tc->tc.tc_get_timecount = acpihwtimer_read_safe;
tc->tc.tc_quality = 900;
} else {
tc->tc.tc_get_timecount = acpihwtimer_read_fast;
tc->tc.tc_quality = 1000;
}
tc->t = t;
tc->h = h;
tc->off = off;
tc->tc.tc_priv = tc;
tc_init(&tc->tc);
aprint_normal("%s: %d-bit timer\n", tc->tc.tc_name,
(flags & ACPIPMT_32BIT ? 32 : 24));
return (0);
}
#define r(h) bus_space_read_4(h->t, h->h, h->off)
static u_int
acpihwtimer_read_safe(struct timecounter *tc)
{
struct hwtc *h = tc->tc_priv;
uint32_t t1, t2, t3;
t2 = r(h);
t3 = r(h);
do {
t1 = t2;
t2 = t3;
t3 = r(h);
} while ((t1 > t2) || (t2 > t3));
return (t2);
}
static u_int
acpihwtimer_read_fast(struct timecounter *tc)
{
struct hwtc *h = tc->tc_priv;
return r(h);
}
#endif