xref: /openbsd-src/sys/dev/acpi/acpitimer.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /* $OpenBSD: acpitimer.c,v 1.10 2012/08/16 18:41:17 tedu 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/malloc.h>
22 #include <sys/timetc.h>
23 
24 #include <machine/bus.h>
25 
26 #include <dev/acpi/acpireg.h>
27 #include <dev/acpi/acpivar.h>
28 
29 int acpitimermatch(struct device *, void *, void *);
30 void acpitimerattach(struct device *, struct device *, void *);
31 
32 u_int acpi_get_timecount(struct timecounter *tc);
33 
34 static struct timecounter acpi_timecounter = {
35 	acpi_get_timecount,	/* get_timecount */
36 	0,			/* no poll_pps */
37 	0x00ffffff,		/* counter_mask (24 bits) */
38 	ACPI_FREQUENCY,		/* frequency */
39 	0,			/* name */
40 	1000			/* quality */
41 };
42 
43 struct acpitimer_softc {
44 	struct device		sc_dev;
45 
46 	bus_space_tag_t		sc_iot;
47 	bus_space_handle_t	sc_ioh;
48 };
49 
50 struct cfattach acpitimer_ca = {
51 	sizeof(struct acpitimer_softc), acpitimermatch, acpitimerattach
52 };
53 
54 struct cfdriver acpitimer_cd = {
55 	NULL, "acpitimer", DV_DULL
56 };
57 
58 int
59 acpitimermatch(struct device *parent, void *match, void *aux)
60 {
61 	struct acpi_attach_args *aa = aux;
62 	struct cfdata *cf = match;
63 
64 	/* sanity */
65 	if (aa->aaa_name == NULL ||
66 	    strcmp(aa->aaa_name, cf->cf_driver->cd_name) != 0 ||
67 	    aa->aaa_table != NULL)
68 		return (0);
69 
70 	return (1);
71 }
72 
73 void
74 acpitimerattach(struct device *parent, struct device *self, void *aux)
75 {
76 	struct acpitimer_softc *sc = (struct acpitimer_softc *) self;
77 	struct acpi_softc *psc = (struct acpi_softc *) parent;
78 	int rc;
79 
80 	if (psc->sc_fadt->hdr_revision >= 3 &&
81 	    psc->sc_fadt->x_pm_tmr_blk.address != 0)
82 		rc = acpi_map_address(psc, &psc->sc_fadt->x_pm_tmr_blk, 0,
83 		    psc->sc_fadt->pm_tmr_len, &sc->sc_ioh, &sc->sc_iot);
84 	else
85 		rc = acpi_map_address(psc, NULL, psc->sc_fadt->pm_tmr_blk,
86 		    psc->sc_fadt->pm_tmr_len, &sc->sc_ioh, &sc->sc_iot);
87 	if (rc) {
88 		printf(": can't map i/o space\n");
89 		return;
90 	}
91 
92 	printf(": %d Hz, %d bits\n", ACPI_FREQUENCY,
93 	    psc->sc_fadt->flags & FADT_TMR_VAL_EXT ? 32 : 24);
94 
95 	if (psc->sc_fadt->flags & FADT_TMR_VAL_EXT)
96 		acpi_timecounter.tc_counter_mask = 0xffffffffU;
97 	acpi_timecounter.tc_priv = sc;
98 	acpi_timecounter.tc_name = sc->sc_dev.dv_xname;
99 	tc_init(&acpi_timecounter);
100 }
101 
102 
103 u_int
104 acpi_get_timecount(struct timecounter *tc)
105 {
106 	struct acpitimer_softc *sc = tc->tc_priv;
107 	u_int u1, u2, u3;
108 
109 	u2 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
110 	u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
111 	do {
112 		u1 = u2;
113 		u2 = u3;
114 		u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0);
115 	} while (u1 > u2 || u2 > u3);
116 
117 	return (u2);
118 }
119