sys/arch/powerpc/ibm4xx/dev/wdog.c

   1 /* $NetBSD: wdog.c,v 1.8 2005/12/11 12:18:42 christos Exp $ */
   2
   3 /*
   4  * Copyright (c) 2002 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Jason R. Thorpe and Simon Burge for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /*
  39  * Watchdog timer support for the IBM 405GP processor.
  40  */
  41
  42 #include <sys/cdefs.h>
  43 __KERNEL_RCSID(0, "$NetBSD: wdog.c,v 1.8 2005/12/11 12:18:42 christos Exp $");
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/device.h>
  48 #include <sys/wdog.h>
  49
  50 #include <prop/proplib.h>
  51
  52 #include <powerpc/spr.h>
  53 #include <powerpc/ibm4xx/dev/opbvar.h>
  54
  55 #include <dev/sysmon/sysmonvar.h>
  56
  57 static int wdog_match(struct device *, struct cfdata *, void *);
  58 static void wdog_attach(struct device *, struct device *, void *);
  59 static int wdog_tickle(struct sysmon_wdog *);
  60 static int wdog_setmode(struct sysmon_wdog *);
  61
  62 struct wdog_softc {
  63         struct device sc_dev;
  64         struct sysmon_wdog sc_smw;
  65         int sc_wdog_armed;
  66         int sc_wdog_period;
  67 };
  68
  69 CFATTACH_DECL(wdog, sizeof(struct wdog_softc),
  70     wdog_match, wdog_attach, NULL, NULL);
  71
  72 static int
  73 wdog_match(struct device *parent, struct cfdata *cf, void *aux)
  74 {
  75         struct opb_attach_args *oaa = aux;
  76
  77         /* match only watchdog devices */
  78         if (strcmp(oaa->opb_name, cf->cf_name) != 0)
  79                 return (0);
  80
  81         return (1);
  82 }
  83
  84 static void
  85 wdog_attach(struct device *parent, struct device *self, void *aux)
  86 {
  87         struct wdog_softc *sc = (void *)self;
  88         unsigned int processor_freq;
  89         prop_number_t freq;
  90
  91         freq = prop_dictionary_get(board_properties, "processor-frequency");
  92         KASSERT(freq != NULL);
  93         processor_freq = (unsigned int) prop_number_integer_value(freq);
  94
  95         sc->sc_wdog_period = (2LL << 29) / processor_freq;
  96         printf(": %d second period\n", sc->sc_wdog_period);
  97
  98         sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
  99         sc->sc_smw.smw_cookie = sc;
 100         sc->sc_smw.smw_setmode = wdog_setmode;
 101         sc->sc_smw.smw_tickle = wdog_tickle;
 102         sc->sc_smw.smw_period = sc->sc_wdog_period;
 103
 104         if (sysmon_wdog_register(&sc->sc_smw) != 0)
 105                 printf("%s: unable to register with sysmon\n",
 106                     sc->sc_dev.dv_xname);
 107
 108 }
 109
 110 static int
 111 wdog_tickle(struct sysmon_wdog *smw)
 112 {
 113         uint32_t tsr;
 114
 115         tsr = mfspr(SPR_TSR);
 116         tsr |= TSR_ENW | TSR_WIS;
 117         mtspr(SPR_TSR, tsr);
 118         return (0);
 119 }
 120
 121 static int
 122 wdog_setmode(struct sysmon_wdog *smw)
 123 {
 124         struct wdog_softc *sc = smw->smw_cookie;
 125         uint32_t tcr, tsr;
 126
 127         if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
 128                 if (sc->sc_wdog_armed) {
 129                         tsr = mfspr(SPR_TSR);
 130                         tsr &= ~(TSR_ENW | TSR_WIS);
 131                         mtspr(SPR_TSR, tsr);
 132                 }
 133         } else {
 134                 if (smw->smw_period == WDOG_PERIOD_DEFAULT)
 135                         smw->smw_period = sc->sc_wdog_period;
 136                 else if (smw->smw_period != sc->sc_wdog_period) {
 137                         /*
 138                          * There's 4 set watchdog periods on the 405GP,
 139                          * but we only support the longest one (2.684
 140                          * seconds).
 141                          */
 142                         return (EOPNOTSUPP);
 143                 }
 144                 sc->sc_wdog_armed = 1;
 145
 146                 tcr = mfspr(SPR_TCR);
 147                 tcr |= TCR_WP_2_29 | TCR_WRC_SYSTEM;
 148                 mtspr(SPR_TCR, tcr);
 149
 150                 /* Arm the watchdog. */
 151                 wdog_tickle(smw);
 152         }
 153         return (0);
 154 }