NetBSD/sys/dev/ic/acpipmtimer.c

98 lines
1.9 KiB
C

/* $NetBSD: acpipmtimer.c,v 1.8 2009/08/18 17:47:46 dyoung Exp $ */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: acpipmtimer.c,v 1.8 2009/08/18 17:47:46 dyoung Exp $");
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/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 *);
acpipmtimer_t
acpipmtimer_attach(device_t 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 == NULL)
return NULL;
tc->tc.tc_name = device_xname(dev);
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 tc;
}
int
acpipmtimer_detach(acpipmtimer_t timer, int flags)
{
struct hwtc *tc = timer;
return tc_detach(&tc->tc);
}
#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);
}