counter.c revision 135971 
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 135971 2004-09-30 14:30:29Z kensmith $
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#define	COUNTER_QUALITY	100
41
42/* Bits in the limit register. */
43#define	CTLR_INTEN	(1U << 31)	/* Enable timer interrupts */
44#define	CTLR_RELOAD	(1U << 30)	/* Zero counter on write to limit reg */
45#define	CTLR_PERIODIC	(1U << 29)	/* Wrap to 0 if limit is reached */
46
47/* Offsets of the registers for the two counters. */
48#define	CTR_CT0		0x00
49#define	CTR_CT1		0x10
50
51/* Register offsets from the base address. */
52#define	CTR_COUNT	0x00
53#define	CTR_LIMIT	0x08
54
55
56static unsigned int counter_get_timecount(struct timecounter *tc);
57
58struct ct_softc {
59	bus_space_tag_t		sc_tag;
60	bus_space_handle_t	sc_handle;
61	bus_addr_t		sc_offset;
62};
63
64
65/*
66 * This is called from the psycho and sbus drivers. It does not directly attach
67 * to the nexus because it shares register space with the bridge in question.
68 */
69void
70sparc64_counter_init(bus_space_tag_t tag, bus_space_handle_t handle,
71    bus_addr_t offset)
72{
73	struct timecounter *tc;
74	struct ct_softc *sc;
75
76	printf("initializing counter-timer\n");
77	/*
78	 * Turn off interrupts from both counters. Set the limit to the maximum
79	 * value (although that should not change anything with CTLR_INTEN and
80	 * CTLR_PERIODIC off).
81	 */
82	bus_space_write_8(tag, handle, offset + CTR_CT0 + CTR_LIMIT,
83	    COUNTER_MASK);
84	bus_space_write_8(tag, handle, offset + CTR_CT1 + CTR_LIMIT,
85	    COUNTER_MASK);
86	/* Register as a time counter. */
87	tc = malloc(sizeof(*tc), M_DEVBUF, M_WAITOK);
88	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
89	sc->sc_tag = tag;
90	sc->sc_handle = handle;
91	sc->sc_offset = offset + CTR_CT0;
92	tc->tc_get_timecount = counter_get_timecount;
93	tc->tc_poll_pps = NULL;
94	tc->tc_counter_mask = COUNTER_MASK;
95	tc->tc_frequency = COUNTER_FREQ;
96	tc->tc_name = "counter-timer";
97	tc->tc_priv = sc;
98	tc->tc_quality = COUNTER_QUALITY;
99	tc_init(tc);
100}
101
102static unsigned int
103counter_get_timecount(struct timecounter *tc)
104{
105	struct ct_softc *sc;
106
107	sc = tc->tc_priv;
108	return (bus_space_read_8(sc->sc_tag, sc->sc_handle, sc->sc_offset) &
109	    COUNTER_MASK);
110}
111