counter.c revision 129083 
1/*-
2 * Copyright (c) 2002 by Thomas Moestl <tmm@FreeBSD.org>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
18 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
21 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
23 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * $FreeBSD: head/sys/sparc64/sparc64/counter.c 129083 2004-05-10 11:07:21Z mux $
26 */
27
28#include <sys/param.h>
29#include <sys/bus.h>
30#include <sys/malloc.h>
31#include <sys/systm.h>
32#include <sys/time.h>
33#include <sys/timetc.h>
34
35#include <machine/bus.h>
36#include <machine/bus_common.h>
37
38#define	COUNTER_MASK	((1 << 29) - 1)
39#define	COUNTER_FREQ	1000000
40
41/* Bits in the limit register. */
42#define	CTLR_INTEN	(1U << 31)	/* Enable timer interrupts */
43#define	CTLR_RELOAD	(1U << 30)	/* Zero counter on write to limit reg */
44#define	CTLR_PERIODIC	(1U << 29)	/* Wrap to 0 if limit is reached */
45
46/* Offsets of the registers for the two counters. */
47#define	CTR_CT0		0x00
48#define	CTR_CT1		0x10
49
50/* Register offsets from the base address. */
51#define	CTR_COUNT	0x00
52#define	CTR_LIMIT	0x08
53
54
55static unsigned counter_get_timecount(struct timecounter *tc);
56
57struct ct_softc {
58	bus_space_tag_t		sc_tag;
59	bus_space_handle_t	sc_handle;
60	bus_addr_t		sc_offset;
61};
62
63
64/*
65 * This is called from the psycho and sbus drivers. It does not directly attach
66 * to the nexus because it shares register space with the bridge in question.
67 */
68void
69sparc64_counter_init(bus_space_tag_t tag, bus_space_handle_t handle,
70    bus_addr_t offset)
71{
72	struct timecounter *tc;
73	struct ct_softc *sc;
74
75	printf("initializing counter-timer\n");
76	/*
77	 * Turn off interrupts from both counters. Set the limit to the maximum
78	 * value (although that should not change anything with CTLR_INTEN and
79	 * CTLR_PERIODIC off).
80	 */
81	bus_space_write_8(tag, handle, offset + CTR_CT0 + CTR_LIMIT,
82	    COUNTER_MASK);
83	bus_space_write_8(tag, handle, offset + CTR_CT1 + CTR_LIMIT,
84	    COUNTER_MASK);
85	/* Register as a time counter. */
86	tc = malloc(sizeof(*tc), M_DEVBUF, M_WAITOK);
87	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
88	sc->sc_tag = tag;
89	sc->sc_handle = handle;
90	sc->sc_offset = offset + CTR_CT0;
91	tc->tc_get_timecount = counter_get_timecount;
92	tc->tc_poll_pps = NULL;
93	tc->tc_counter_mask = COUNTER_MASK;
94	tc->tc_frequency = COUNTER_FREQ;
95	tc->tc_name = "counter-timer";
96	tc->tc_priv = sc;
97	tc_init(tc);
98}
99
100static unsigned int
101counter_get_timecount(struct timecounter *tc)
102{
103	struct ct_softc *sc;
104
105	sc = tc->tc_priv;
106	return (bus_space_read_8(sc->sc_tag, sc->sc_handle, sc->sc_offset) &
107	    COUNTER_MASK);
108}
109