1 /* $NetBSD: hpet.c,v 1.10 2010/02/24 22:37:58 dyoung 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 1.10 2010/02/24 22:37:58 dyoung 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 static bool hpet_resume(device_t, const pmf_qual_t *); 52 53 int 54 hpet_detach(device_t dv, int flags) 55 { 56 struct hpet_softc *sc = device_private(dv); 57 int rc; 58 59 if ((rc = tc_detach(&sc->sc_tc)) != 0) 60 return rc; 61 62 pmf_device_deregister(dv); 63 64 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, sc->sc_config); 65 66 return 0; 67 } 68 69 void 70 hpet_attach_subr(device_t dv) 71 { 72 struct hpet_softc *sc = device_private(dv); 73 struct timecounter *tc; 74 uint32_t val; 75 76 tc = &sc->sc_tc; 77 78 tc->tc_name = device_xname(dv); 79 tc->tc_get_timecount = hpet_get_timecount; 80 tc->tc_quality = 2000; 81 82 tc->tc_counter_mask = 0xffffffff; 83 84 /* Get frequency */ 85 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_PERIOD); 86 if (val == 0) { 87 aprint_error_dev(dv, "invalid timer period\n"); 88 return; 89 } 90 tc->tc_frequency = 1000000000000000ULL / val; 91 92 /* Enable timer */ 93 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG); 94 sc->sc_config = val; 95 if ((val & HPET_CONFIG_ENABLE) == 0) { 96 val |= HPET_CONFIG_ENABLE; 97 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val); 98 } 99 100 tc->tc_priv = sc; 101 tc_init(tc); 102 103 if (!pmf_device_register(dv, NULL, hpet_resume)) 104 aprint_error_dev(dv, "couldn't establish power handler\n"); 105 } 106 107 static u_int 108 hpet_get_timecount(struct timecounter *tc) 109 { 110 struct hpet_softc *sc = tc->tc_priv; 111 112 return bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_MCOUNT_LO); 113 } 114 115 static bool 116 hpet_resume(device_t dv, const pmf_qual_t *qual) 117 { 118 struct hpet_softc *sc = device_private(dv); 119 uint32_t val; 120 121 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG); 122 val |= HPET_CONFIG_ENABLE; 123 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val); 124 125 return true; 126 } 127