xref: /openbsd/sys/dev/acpi/acpitimer.c (revision 73471bf0)
1 /* $OpenBSD: acpitimer.c,v 1.14 2021/02/23 04:44:31 cheloha Exp $ */
2 /*
3  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/device.h>
21 #include <sys/timetc.h>
22 
23 #include <machine/bus.h>
24 
25 #include <dev/acpi/acpireg.h>
26 #include <dev/acpi/acpivar.h>
27 
28 int acpitimermatch(struct device *, void *, void *);
29 void acpitimerattach(struct device *, struct device *, void *);
30 
31 u_int acpi_get_timecount(struct timecounter *tc);
32 
33 static struct timecounter acpi_timecounter = {
34 	.tc_get_timecount = acpi_get_timecount,
35 	.tc_poll_pps = 0,
36 	.tc_counter_mask = 0x00ffffff,		/* 24 bits */
37 	.tc_frequency = ACPI_FREQUENCY,
38 	.tc_name = 0,
39 	.tc_quality = 1000,
40 	.tc_priv = NULL,
41 	.tc_user = 0,
42 };
43 
44 struct acpitimer_softc {
45 	struct device		sc_dev;
46 
47 	bus_space_tag_t		sc_iot;
48 	bus_space_handle_t	sc_ioh;
49 };
50 
51 struct cfattach acpitimer_ca = {
52 	sizeof(struct acpitimer_softc), acpitimermatch, acpitimerattach
53 };
54 
55 struct cfdriver acpitimer_cd = {
56 	NULL, "acpitimer", DV_DULL
57 };
58 
59 int
60 acpitimermatch(struct device *parent, void *match, void *aux)
61 {
62 	struct acpi_attach_args *aa = aux;
63 	struct cfdata *cf = match;
64 
65 	/* sanity */
66 	if (aa->aaa_name == NULL ||
67 	    strcmp(aa->aaa_name, cf->cf_driver->cd_name) != 0 ||
68 	    aa->aaa_table != NULL)
69 		return (0);
70 
71 	return (1);
72 }
73 
74 void
75 acpitimerattach(struct device *parent, struct device *self, void *aux)
76 {
77 	struct acpitimer_softc *sc = (struct acpitimer_softc *) self;
78 	struct acpi_softc *psc = (struct acpi_softc *) parent;
79 	int rc;
80 
81 	if (psc->sc_fadt->hdr_revision >= 3 &&
82 	    psc->sc_fadt->x_pm_tmr_blk.address != 0)
83 		rc = acpi_map_address(psc, &psc->sc_fadt->x_pm_tmr_blk, 0,
84 		    psc->sc_fadt->pm_tmr_len, &sc->sc_ioh, &sc->sc_iot);
85 	else
86 		rc = acpi_map_address(psc, NULL, psc->sc_fadt->pm_tmr_blk,
87 		    psc->sc_fadt->pm_tmr_len, &sc->sc_ioh, &sc->sc_iot);
88 	if (rc) {
89 		printf(": can't map i/o space\n");
90 		return;
91 	}
92 
93 	printf(": %d Hz, %d bits\n", ACPI_FREQUENCY,
94 	    psc->sc_fadt->flags & FADT_TMR_VAL_EXT ? 32 : 24);
95 
96 	if (psc->sc_fadt->flags & FADT_TMR_VAL_EXT)
97 		acpi_timecounter.tc_counter_mask = 0xffffffffU;
98 	acpi_timecounter.tc_priv = sc;
99 	acpi_timecounter.tc_name = sc->sc_dev.dv_xname;
100 	tc_init(&acpi_timecounter);
101 #if defined(__amd64__)
102 	extern void cpu_recalibrate_tsc(struct timecounter *);
103 	cpu_recalibrate_tsc(&acpi_timecounter);
104 #endif
105 }
106 
107 
108 u_int
109 acpi_get_timecount(struct timecounter *tc)
110 {
111 	struct acpitimer_softc *sc = tc->tc_priv;
112 	u_int u1, u2, u3;
113 
114 	u2 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
115 	u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
116 	do {
117 		u1 = u2;
118 		u2 = u3;
119 		u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
120 	} while (u1 > u2 || u2 > u3);
121 
122 	return (u2);
123 }
124