168 lines
3.8 KiB
C
168 lines
3.8 KiB
C
/* $NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2006 Matthias Drochner <drochner@NetBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $");
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/time.h>
|
|
#include <sys/timetc.h>
|
|
|
|
#include <dev/acpi/acpivar.h>
|
|
#include <dev/acpi/acpi_timer.h>
|
|
|
|
#include <machine/acpi_machdep.h>
|
|
|
|
static int acpitimer_test(void);
|
|
static uint32_t acpitimer_delta(uint32_t, uint32_t);
|
|
static u_int acpitimer_read_safe(struct timecounter *);
|
|
static u_int acpitimer_read_fast(struct timecounter *);
|
|
|
|
static struct timecounter acpi_timecounter = {
|
|
acpitimer_read_safe,
|
|
0,
|
|
0x00ffffff,
|
|
PM_TIMER_FREQUENCY,
|
|
"ACPI-Safe",
|
|
900,
|
|
NULL,
|
|
NULL,
|
|
};
|
|
|
|
int
|
|
acpitimer_init(void)
|
|
{
|
|
uint32_t bits;
|
|
int i, j;
|
|
ACPI_STATUS res;
|
|
|
|
res = AcpiGetTimerResolution(&bits);
|
|
if (res != AE_OK)
|
|
return (-1);
|
|
|
|
if (bits == 32)
|
|
acpi_timecounter.tc_counter_mask = 0xffffffff;
|
|
|
|
j = 0;
|
|
for (i = 0; i < 10; i++)
|
|
j += acpitimer_test();
|
|
|
|
if (j >= 10) {
|
|
acpi_timecounter.tc_name = "ACPI-Fast";
|
|
acpi_timecounter.tc_get_timecount = acpitimer_read_fast;
|
|
acpi_timecounter.tc_quality = 1000;
|
|
}
|
|
|
|
tc_init(&acpi_timecounter);
|
|
aprint_verbose("%s %d-bit timer\n", acpi_timecounter.tc_name, bits);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
acpitimer_detach(void)
|
|
{
|
|
return tc_detach(&acpi_timecounter);
|
|
}
|
|
|
|
static u_int
|
|
acpitimer_read_fast(struct timecounter *tc)
|
|
{
|
|
uint32_t t;
|
|
|
|
AcpiGetTimer(&t);
|
|
return (t);
|
|
}
|
|
|
|
/*
|
|
* Some chipsets (PIIX4 variants) do not latch correctly; there
|
|
* is a chance that a transition is hit.
|
|
*/
|
|
static u_int
|
|
acpitimer_read_safe(struct timecounter *tc)
|
|
{
|
|
uint32_t t1, t2, t3;
|
|
|
|
AcpiGetTimer(&t2);
|
|
AcpiGetTimer(&t3);
|
|
do {
|
|
t1 = t2;
|
|
t2 = t3;
|
|
AcpiGetTimer(&t3);
|
|
} while ((t1 > t2) || (t2 > t3));
|
|
return (t2);
|
|
}
|
|
|
|
static uint32_t
|
|
acpitimer_delta(uint32_t end, uint32_t start)
|
|
{
|
|
uint32_t delta;
|
|
u_int mask = acpi_timecounter.tc_counter_mask;
|
|
|
|
if (end >= start)
|
|
delta = end - start;
|
|
else
|
|
delta = ((mask - start) + end + 1) & mask;
|
|
|
|
return (delta);
|
|
}
|
|
|
|
#define N 2000
|
|
static int
|
|
acpitimer_test(void)
|
|
{
|
|
uint32_t last, this, delta;
|
|
int minl, maxl, n;
|
|
|
|
minl = 10000000;
|
|
maxl = 0;
|
|
|
|
acpi_md_OsDisableInterrupt();
|
|
AcpiGetTimer(&last);
|
|
for (n = 0; n < N; n++) {
|
|
AcpiGetTimer(&this);
|
|
delta = acpitimer_delta(this, last);
|
|
if (delta > maxl)
|
|
maxl = delta;
|
|
else if (delta < minl)
|
|
minl = delta;
|
|
last = this;
|
|
}
|
|
acpi_md_OsEnableInterrupt();
|
|
|
|
if (maxl - minl > 2 )
|
|
n = 0;
|
|
else if (minl < 0 || maxl == 0)
|
|
n = 0;
|
|
else
|
|
n = 1;
|
|
|
|
return (n);
|
|
}
|