sys/dev/ic/hpet.c

   1 /* $NetBSD: hpet.c,v 1.8 2009/09/30 15:22:11 njoly 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 1.8 2009/09/30 15:22:11 njoly 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, 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, 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 }