93 lines
3.0 KiB
C
93 lines
3.0 KiB
C
/* $NetBSD: hpet.c,v 1.1 2007/03/08 14:26:28 njoly Exp $ */
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/*
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* Copyright (c) 2006 Nicolas Joly
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* High Precision Event Timer.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: hpet.c,v 1.1 2007/03/08 14:26:28 njoly Exp $");
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#include <sys/systm.h>
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#include <sys/device.h>
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#include <sys/malloc.h>
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#include <sys/time.h>
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#include <sys/timetc.h>
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#include <machine/bus.h>
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#include <dev/ic/hpetreg.h>
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#include <dev/ic/hpetvar.h>
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static u_int hpet_get_timecount(struct timecounter *);
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void
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hpet_attach_subr(struct hpet_softc *sc) {
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struct timecounter *tc;
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uint32_t val;
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tc = &sc->sc_tc;
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tc->tc_name = sc->sc_dev.dv_xname;
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tc->tc_get_timecount = hpet_get_timecount;
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tc->tc_quality = 2000;
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/* XXX Only 32-bits supported for now */
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val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_INFO);
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if ((val & HPET_INFO_64BITS) != 0) {
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aprint_normal("%s: Found 64-bits HPET, will only use lowest"
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" 32-bits\n", sc->sc_dev.dv_xname);
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}
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tc->tc_counter_mask = 0xffffffff;
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/* Get frequency */
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val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_PERIOD);
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tc->tc_frequency = 1000000000000000ULL / val;
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/* Enable timer */
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val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG);
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if ((val & HPET_CONFIG_ENABLE) == 0) {
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val |= HPET_CONFIG_ENABLE;
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bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val);
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}
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tc->tc_priv = sc;
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tc_init(tc);
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}
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static u_int
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hpet_get_timecount(struct timecounter *tc) {
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struct hpet_softc *sc = tc->tc_priv;
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return bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_MCOUNT);
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}
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