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acpi_timer.c revision 1.2.2.2 
      1  1.2.2.2  yamt /* $NetBSD: acpi_timer.c,v 1.2.2.2 2006/06/26 12:50:37 yamt Exp $ */
      2  1.2.2.2  yamt 
      3  1.2.2.2  yamt #include <sys/types.h>
      4  1.2.2.2  yamt 
      5  1.2.2.2  yamt #ifdef __HAVE_TIMECOUNTER
      6  1.2.2.2  yamt 
      7  1.2.2.2  yamt #include <sys/systm.h>
      8  1.2.2.2  yamt #include <sys/time.h>
      9  1.2.2.2  yamt #include <sys/timetc.h>
     10  1.2.2.2  yamt #include <dev/acpi/acpica.h>
     11  1.2.2.2  yamt #include <dev/acpi/acpi_timer.h>
     12  1.2.2.2  yamt 
     13  1.2.2.2  yamt static u_int acpitimer_read(struct timecounter *);
     14  1.2.2.2  yamt 
     15  1.2.2.2  yamt static struct timecounter acpi_timecounter = {
     16  1.2.2.2  yamt 	acpitimer_read,
     17  1.2.2.2  yamt 	0,
     18  1.2.2.2  yamt 	0x00ffffff,
     19  1.2.2.2  yamt 	PM_TIMER_FREQUENCY,
     20  1.2.2.2  yamt 	"ACPI_PM_TMR",
     21  1.2.2.2  yamt 	900
     22  1.2.2.2  yamt };
     23  1.2.2.2  yamt 
     24  1.2.2.2  yamt int
     25  1.2.2.2  yamt acpitimer_init()
     26  1.2.2.2  yamt {
     27  1.2.2.2  yamt 	uint32_t bits;
     28  1.2.2.2  yamt 	ACPI_STATUS res;
     29  1.2.2.2  yamt 
     30  1.2.2.2  yamt 	res = AcpiGetTimerResolution(&bits);
     31  1.2.2.2  yamt 	if (res != AE_OK)
     32  1.2.2.2  yamt 		return (-1);
     33  1.2.2.2  yamt 
     34  1.2.2.2  yamt 	if (bits == 32)
     35  1.2.2.2  yamt 		acpi_timecounter.tc_counter_mask = 0xffffffff;
     36  1.2.2.2  yamt 	tc_init(&acpi_timecounter);
     37  1.2.2.2  yamt 
     38  1.2.2.2  yamt 	printf("acpitimer: %d bits\n", bits);
     39  1.2.2.2  yamt 
     40  1.2.2.2  yamt 	return (0);
     41  1.2.2.2  yamt }
     42  1.2.2.2  yamt 
     43  1.2.2.2  yamt /*
     44  1.2.2.2  yamt  * Some chipsets (PIIX4 variants) do not latch correctly; there
     45  1.2.2.2  yamt  * is a chance that a transition is hit.
     46  1.2.2.2  yamt  * For now, just be conservative. We might detect the situation later
     47  1.2.2.2  yamt  * (by testing, or chipset quirks).
     48  1.2.2.2  yamt  */
     49  1.2.2.2  yamt static u_int
     50  1.2.2.2  yamt acpitimer_read(struct timecounter *tc)
     51  1.2.2.2  yamt {
     52  1.2.2.2  yamt 	uint32_t t1, t2, t3;
     53  1.2.2.2  yamt 
     54  1.2.2.2  yamt 	AcpiGetTimer(&t2);
     55  1.2.2.2  yamt 	AcpiGetTimer(&t3);
     56  1.2.2.2  yamt 	do {
     57  1.2.2.2  yamt 		t1 = t2;
     58  1.2.2.2  yamt 		t2 = t3;
     59  1.2.2.2  yamt 		AcpiGetTimer(&t3);
     60  1.2.2.2  yamt 	} while ((t1 > t2) || (t2 > t3));
     61  1.2.2.2  yamt 	return (t2);
     62  1.2.2.2  yamt }
     63  1.2.2.2  yamt 
     64  1.2.2.2  yamt #else
     65  1.2.2.2  yamt 
     66  1.2.2.2  yamt int
     67  1.2.2.2  yamt acpitimer_init()
     68  1.2.2.2  yamt {
     69  1.2.2.2  yamt 
     70  1.2.2.2  yamt 	return (0);
     71  1.2.2.2  yamt }
     72  1.2.2.2  yamt 
     73  1.2.2.2  yamt #endif
     74