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acpi_timer.c revision 1.16
      1  1.16    jruoho /* $NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $ */
      2  1.16    jruoho 
      3  1.16    jruoho /*-
      4  1.16    jruoho  * Copyright (c) 2006 Matthias Drochner <drochner (at) NetBSD.org>
      5  1.16    jruoho  * All rights reserved.
      6  1.16    jruoho  *
      7  1.16    jruoho  * Redistribution and use in source and binary forms, with or without
      8  1.16    jruoho  * modification, are permitted provided that the following conditions
      9  1.16    jruoho  * are met:
     10  1.16    jruoho  * 1. Redistributions of source code must retain the above copyright
     11  1.16    jruoho  *    notice, this list of conditions and the following disclaimer.
     12  1.16    jruoho  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.16    jruoho  *    notice, this list of conditions and the following disclaimer in the
     14  1.16    jruoho  *    documentation and/or other materials provided with the distribution.
     15  1.16    jruoho  *
     16  1.16    jruoho  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  1.16    jruoho  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  1.16    jruoho  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  1.16    jruoho  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  1.16    jruoho  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  1.16    jruoho  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  1.16    jruoho  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  1.16    jruoho  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  1.16    jruoho  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  1.16    jruoho  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  1.16    jruoho  * POSSIBILITY OF SUCH DAMAGE.
     27  1.16    jruoho  */
     28   1.4   xtraeme 
     29   1.4   xtraeme #include <sys/cdefs.h>
     30  1.16    jruoho __KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $");
     31   1.1  drochner 
     32   1.1  drochner #include <sys/types.h>
     33   1.1  drochner #include <sys/systm.h>
     34   1.1  drochner #include <sys/time.h>
     35   1.1  drochner #include <sys/timetc.h>
     36  1.15    jruoho 
     37  1.15    jruoho #include <dev/acpi/acpivar.h>
     38  1.10     joerg #include <dev/acpi/acpi_timer.h>
     39  1.15    jruoho 
     40  1.12  jmcneill #include <machine/acpi_machdep.h>
     41   1.1  drochner 
     42   1.2  drochner static int acpitimer_test(void);
     43   1.2  drochner static uint32_t acpitimer_delta(uint32_t, uint32_t);
     44   1.2  drochner static u_int acpitimer_read_safe(struct timecounter *);
     45   1.2  drochner static u_int acpitimer_read_fast(struct timecounter *);
     46   1.1  drochner 
     47   1.1  drochner static struct timecounter acpi_timecounter = {
     48   1.2  drochner 	acpitimer_read_safe,
     49   1.1  drochner 	0,
     50   1.1  drochner 	0x00ffffff,
     51   1.1  drochner 	PM_TIMER_FREQUENCY,
     52   1.2  drochner 	"ACPI-Safe",
     53   1.6  christos 	900,
     54   1.6  christos 	NULL,
     55   1.6  christos 	NULL,
     56   1.1  drochner };
     57   1.1  drochner 
     58   1.1  drochner int
     59  1.13    cegger acpitimer_init(void)
     60   1.1  drochner {
     61   1.1  drochner 	uint32_t bits;
     62   1.2  drochner 	int i, j;
     63   1.1  drochner 	ACPI_STATUS res;
     64   1.1  drochner 
     65   1.1  drochner 	res = AcpiGetTimerResolution(&bits);
     66   1.1  drochner 	if (res != AE_OK)
     67   1.1  drochner 		return (-1);
     68   1.1  drochner 
     69   1.1  drochner 	if (bits == 32)
     70   1.1  drochner 		acpi_timecounter.tc_counter_mask = 0xffffffff;
     71   1.2  drochner 
     72   1.2  drochner 	j = 0;
     73   1.2  drochner 	for (i = 0; i < 10; i++)
     74   1.2  drochner 		j += acpitimer_test();
     75   1.3   xtraeme 
     76   1.2  drochner 	if (j >= 10) {
     77   1.2  drochner 		acpi_timecounter.tc_name = "ACPI-Fast";
     78   1.2  drochner 		acpi_timecounter.tc_get_timecount = acpitimer_read_fast;
     79   1.2  drochner 		acpi_timecounter.tc_quality = 1000;
     80   1.2  drochner 	}
     81   1.2  drochner 
     82   1.1  drochner 	tc_init(&acpi_timecounter);
     83  1.11        ad 	aprint_verbose("%s %d-bit timer\n", acpi_timecounter.tc_name, bits);
     84   1.1  drochner 
     85   1.2  drochner 	return (0);
     86   1.2  drochner }
     87   1.1  drochner 
     88  1.14    dyoung int
     89  1.14    dyoung acpitimer_detach(void)
     90  1.14    dyoung {
     91  1.14    dyoung 	return tc_detach(&acpi_timecounter);
     92  1.14    dyoung }
     93  1.14    dyoung 
     94   1.2  drochner static u_int
     95   1.8  christos acpitimer_read_fast(struct timecounter *tc)
     96   1.2  drochner {
     97   1.2  drochner 	uint32_t t;
     98   1.2  drochner 
     99   1.2  drochner 	AcpiGetTimer(&t);
    100   1.2  drochner 	return (t);
    101   1.1  drochner }
    102   1.1  drochner 
    103   1.1  drochner /*
    104   1.1  drochner  * Some chipsets (PIIX4 variants) do not latch correctly; there
    105   1.1  drochner  * is a chance that a transition is hit.
    106   1.1  drochner  */
    107   1.1  drochner static u_int
    108   1.8  christos acpitimer_read_safe(struct timecounter *tc)
    109   1.1  drochner {
    110   1.1  drochner 	uint32_t t1, t2, t3;
    111   1.1  drochner 
    112   1.1  drochner 	AcpiGetTimer(&t2);
    113   1.1  drochner 	AcpiGetTimer(&t3);
    114   1.1  drochner 	do {
    115   1.1  drochner 		t1 = t2;
    116   1.1  drochner 		t2 = t3;
    117   1.1  drochner 		AcpiGetTimer(&t3);
    118   1.1  drochner 	} while ((t1 > t2) || (t2 > t3));
    119   1.1  drochner 	return (t2);
    120   1.1  drochner }
    121   1.1  drochner 
    122   1.2  drochner static uint32_t
    123   1.2  drochner acpitimer_delta(uint32_t end, uint32_t start)
    124   1.2  drochner {
    125   1.2  drochner 	uint32_t delta;
    126   1.2  drochner 	u_int mask = acpi_timecounter.tc_counter_mask;
    127   1.2  drochner 
    128   1.2  drochner 	if (end >= start)
    129   1.2  drochner 		delta = end - start;
    130   1.2  drochner 	else
    131   1.2  drochner 		delta = ((mask - start) + end + 1) & mask;
    132   1.2  drochner 
    133   1.2  drochner 	return (delta);
    134   1.2  drochner }
    135   1.2  drochner 
    136   1.2  drochner #define N 2000
    137   1.2  drochner static int
    138  1.13    cegger acpitimer_test(void)
    139   1.2  drochner {
    140   1.2  drochner 	uint32_t last, this, delta;
    141   1.2  drochner 	int minl, maxl, n;
    142   1.2  drochner 
    143   1.2  drochner 	minl = 10000000;
    144   1.2  drochner 	maxl = 0;
    145   1.2  drochner 
    146  1.12  jmcneill 	acpi_md_OsDisableInterrupt();
    147   1.2  drochner 	AcpiGetTimer(&last);
    148   1.2  drochner 	for (n = 0; n < N; n++) {
    149   1.2  drochner 		AcpiGetTimer(&this);
    150   1.2  drochner 		delta = acpitimer_delta(this, last);
    151   1.2  drochner 		if (delta > maxl)
    152   1.2  drochner 			maxl = delta;
    153   1.2  drochner 		else if (delta < minl)
    154   1.2  drochner 			minl = delta;
    155   1.2  drochner 		last = this;
    156   1.2  drochner 	}
    157  1.12  jmcneill 	acpi_md_OsEnableInterrupt();
    158   1.2  drochner 
    159   1.2  drochner 	if (maxl - minl > 2 )
    160   1.2  drochner 		n = 0;
    161   1.2  drochner 	else if (minl < 0 || maxl == 0)
    162   1.2  drochner 		n = 0;
    163   1.2  drochner 	else
    164   1.2  drochner 		n = 1;
    165   1.2  drochner 
    166   1.2  drochner 	return (n);
    167   1.2  drochner }
    168