1 /* $NetBSD: hpet.c,v 1.2 2007/10/19 11:59:52 ad Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Nicolas Joly 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 /* 32 * High Precision Event Timer. 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: hpet.c,v 1.2 2007/10/19 11:59:52 ad Exp $"); 37 38 #include <sys/systm.h> 39 #include <sys/device.h> 40 #include <sys/malloc.h> 41 42 #include <sys/time.h> 43 #include <sys/timetc.h> 44 45 #include <sys/bus.h> 46 47 #include <dev/ic/hpetreg.h> 48 #include <dev/ic/hpetvar.h> 49 50 static u_int hpet_get_timecount(struct timecounter *); 51 52 void 53 hpet_attach_subr(struct hpet_softc *sc) { 54 struct timecounter *tc; 55 uint32_t val; 56 57 tc = &sc->sc_tc; 58 59 tc->tc_name = sc->sc_dev.dv_xname; 60 tc->tc_get_timecount = hpet_get_timecount; 61 tc->tc_quality = 2000; 62 63 /* XXX Only 32-bits supported for now */ 64 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_INFO); 65 if ((val & HPET_INFO_64BITS) != 0) { 66 aprint_normal("%s: Found 64-bits HPET, will only use lowest" 67 " 32-bits\n", sc->sc_dev.dv_xname); 68 } 69 tc->tc_counter_mask = 0xffffffff; 70 71 /* Get frequency */ 72 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_PERIOD); 73 tc->tc_frequency = 1000000000000000ULL / val; 74 75 /* Enable timer */ 76 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG); 77 if ((val & HPET_CONFIG_ENABLE) == 0) { 78 val |= HPET_CONFIG_ENABLE; 79 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val); 80 } 81 82 tc->tc_priv = sc; 83 tc_init(tc); 84 } 85 86 static u_int 87 hpet_get_timecount(struct timecounter *tc) { 88 struct hpet_softc *sc = tc->tc_priv; 89 90 return bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_MCOUNT); 91 } 92 93