sys/arch/arm/xscale/ixp425_wdog.c

   1 /*      $NetBSD: ixp425_wdog.c,v 1.1 2006/12/10 10:03:22 scw Exp $      */
   2
   3 /*-
   4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Steve C. Woodford.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "opt_ddb.h"
  33
  34 #include <sys/cdefs.h>
  35 __KERNEL_RCSID(0, "$NetBSD: ixp425_wdog.c,v 1.1 2006/12/10 10:03:22 scw Exp $");
  36
  37 #include <sys/systm.h>
  38 #include <sys/param.h>
  39 #include <sys/kernel.h>
  40 #include <sys/device.h>
  41 #include <sys/wdog.h>
  42
  43 #include <dev/clock_subr.h>
  44 #include <dev/sysmon/sysmonvar.h>
  45
  46 #include <machine/intr.h>
  47 #include <machine/bus.h>
  48
  49 #include <arm/xscale/ixp425reg.h>
  50 #include <arm/xscale/ixp425var.h>
  51 #include <arm/xscale/ixp425_sipvar.h>
  52
  53 #ifdef DDB
  54 #include <machine/db_machdep.h>
  55 #include <ddb/db_extern.h>
  56 #endif
  57
  58 struct ixpdog_softc {
  59         struct device sc_dev;
  60         struct sysmon_wdog sc_smw;
  61         bus_space_tag_t sc_bust;
  62         bus_space_handle_t sc_bush;
  63         uint32_t sc_preset;
  64         int sc_armed;
  65 };
  66
  67 #define IXPDOG_DEFAULT_PERIOD   8
  68 #ifndef IXP425_CLOCK_FREQ
  69 #define IXPDOG_COUNTS_PER_SEC   66666600
  70 #else
  71 #define IXPDOG_COUNTS_PER_SEC   IXP425_CLOCK_FREQ
  72 #endif
  73
  74 static int ixpdog_match(struct device *, struct cfdata *, void *);
  75 static void ixpdog_attach(struct device *, struct device *, void *);
  76
  77 CFATTACH_DECL(ixpdog, sizeof(struct ixpdog_softc),
  78     ixpdog_match, ixpdog_attach, NULL, NULL);
  79
  80 static void ixpdog_control(struct ixpdog_softc *, int);
  81 static int ixpdog_tickle(struct sysmon_wdog *);
  82 static int ixpdog_setmode(struct sysmon_wdog *);
  83
  84 #ifdef DDB
  85 static struct ixpdog_softc *ixpdog_softc;
  86 static void ixpdog_ddb_trap(int);
  87 #endif
  88
  89
  90 static int
  91 ixpdog_match(struct device *parent, struct cfdata *match, void *arg)
  92 {
  93         struct ixpsip_attach_args *sa = arg;
  94
  95         return (sa->sa_addr == IXP425_OST_WDOG_HWBASE);
  96 }
  97
  98 static void
  99 ixpdog_attach(struct device *parent, struct device *self, void *arg)
 100 {
 101         struct ixpdog_softc *sc = (struct ixpdog_softc *)self;
 102         struct ixpsip_attach_args *sa = arg;
 103
 104         aprint_naive("\n");
 105         aprint_normal(": Watchdog Timer\n");
 106
 107         sc->sc_bust = sa->sa_iot;
 108
 109         if (bus_space_map(sc->sc_bust, sa->sa_addr, IXP425_OST_WDOG_SIZE, 0,
 110             &sc->sc_bush)) {
 111                 aprint_error("%s: Failed to map watchdog registers\n",
 112                     sc->sc_dev.dv_xname);
 113                 return;
 114         }
 115
 116         sc->sc_preset = IXPDOG_COUNTS_PER_SEC * hz * IXPDOG_DEFAULT_PERIOD;
 117         sc->sc_armed = 0;
 118         ixpdog_control(sc, 0);
 119
 120 #ifdef DDB
 121         ixpdog_softc = sc;
 122         db_trap_callback = ixpdog_ddb_trap;
 123 #endif
 124
 125         sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
 126         sc->sc_smw.smw_cookie = sc;
 127         sc->sc_smw.smw_setmode = ixpdog_setmode;
 128         sc->sc_smw.smw_tickle = ixpdog_tickle;
 129         sc->sc_smw.smw_period = IXPDOG_DEFAULT_PERIOD;
 130
 131         if (sysmon_wdog_register(&sc->sc_smw) != 0)
 132                 aprint_error("%s: unable to register watchdog with sysmon\n",
 133                     sc->sc_dev.dv_xname);
 134 }
 135
 136 static void
 137 ixpdog_control(struct ixpdog_softc *sc, int enable)
 138 {
 139         uint32_t reg;
 140         int s;
 141
 142         s = disable_interrupts(I32_bit);
 143         bus_space_write_2(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_KEY,
 144             OST_WDOG_KEY_MAJICK);
 145         reg = bus_space_read_4(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_ENAB);
 146
 147         if (!enable)
 148                 reg &= ~(OST_WDOG_ENAB_CNT_ENA | OST_WDOG_ENAB_RST_ENA);
 149         else {
 150                 bus_space_write_4(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG,
 151                     sc->sc_preset);
 152                 reg |= OST_WDOG_ENAB_CNT_ENA | OST_WDOG_ENAB_RST_ENA;
 153         }
 154
 155         bus_space_write_4(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_ENAB, reg);
 156         bus_space_write_2(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_KEY,
 157             ~OST_WDOG_KEY_MAJICK);
 158         restore_interrupts(s);
 159 }
 160
 161 static int
 162 ixpdog_tickle(struct sysmon_wdog *smw)
 163 {
 164         struct ixpdog_softc *sc = smw->smw_cookie;
 165         int s;
 166
 167         s = disable_interrupts(I32_bit);
 168         bus_space_write_2(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_KEY,
 169             OST_WDOG_KEY_MAJICK);
 170         bus_space_write_4(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG,
 171             sc->sc_preset);
 172         bus_space_write_2(sc->sc_bust, sc->sc_bush, IXP425_OST_WDOG_KEY,
 173             ~OST_WDOG_KEY_MAJICK);
 174         restore_interrupts(s);
 175
 176         return (0);
 177 }
 178
 179 static int
 180 ixpdog_setmode(struct sysmon_wdog *smw)
 181 {
 182         struct ixpdog_softc *sc = smw->smw_cookie;
 183
 184         if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED)
 185                 sc->sc_armed = 0;
 186         else {
 187                 if (smw->smw_period == WDOG_PERIOD_DEFAULT)
 188                         smw->smw_period = IXPDOG_DEFAULT_PERIOD;
 189                 sc->sc_preset = IXPDOG_COUNTS_PER_SEC * hz * smw->smw_period;
 190                 if (sc->sc_preset < (IXPDOG_COUNTS_PER_SEC * hz) ||
 191                     sc->sc_preset < smw->smw_period)
 192                         return (EOPNOTSUPP);
 193
 194                 sc->sc_armed = 1;
 195         }
 196
 197         ixpdog_control(sc, sc->sc_armed);
 198
 199         return (0);
 200 }
 201
 202 #ifdef DDB
 203 static void
 204 ixpdog_ddb_trap(int enter)
 205 {
 206         struct ixpdog_softc *sc;
 207
 208         if ((sc = ixpdog_softc) == NULL)
 209                 return;
 210
 211         sc->sc_armed += enter ? (-1) : 1;
 212
 213         if ((enter && sc->sc_armed == 0) || (!enter && sc->sc_armed == 1))
 214                 ixpdog_control(sc, sc->sc_armed);
 215 }
 216 #endif