sys/mips/atheros/ar71xx_wdog.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
   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 unmodified, this list of conditions, and the following
  12  *    disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Watchdog driver for AR71xx
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/eventhandler.h>
  39 #include <sys/systm.h>
  40 #include <sys/watchdog.h>
  41 #include <sys/bus.h>
  42 #include <sys/kernel.h>
  43 #include <sys/module.h>
  44 #include <sys/sysctl.h>
  45
  46 #include <mips/atheros/ar71xxreg.h>
  47 #include <mips/atheros/ar71xx_cpudef.h>
  48
  49 struct ar71xx_wdog_softc {
  50         device_t dev;
  51         int armed;
  52         int reboot_from_watchdog;
  53         int watchdog_nmi;
  54         int debug;
  55 };
  56
  57 static void
  58 ar71xx_wdog_watchdog_fn(void *private, u_int cmd, int *error)
  59 {
  60         struct ar71xx_wdog_softc *sc = private;
  61         uint64_t timer_val;
  62         int action;
  63
  64         action = RST_WDOG_ACTION_RESET;
  65         if (sc->watchdog_nmi != 0)
  66                 action = RST_WDOG_ACTION_NMI;
  67
  68         cmd &= WD_INTERVAL;
  69         if (sc->debug)
  70                 device_printf(sc->dev, "%s: : cmd: %x\n", __func__, cmd);
  71         if (cmd > 0) {
  72                 timer_val = (uint64_t)(1ULL << cmd) * ar71xx_ahb_freq() /
  73                     1000000000;
  74
  75                 /*
  76                  * Clamp the timer value in case we overflow.
  77                  */
  78                 if (timer_val > 0xffffffff)
  79                         timer_val = 0xffffffff;
  80                 if (sc->debug)
  81                         device_printf(sc->dev, "%s: programming timer: %jx\n",
  82                             __func__, (uintmax_t) timer_val);
  83                 /*
  84                  * Make sure the watchdog is set to NOACTION and give it
  85                  * time to take.
  86                  */
  87                 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
  88                 wmb();
  89                 DELAY(100);
  90
  91                 /*
  92                  * Update the timer value.  It's already clamped at this
  93                  * point so we don't have to wrap/clamp it here.
  94                  */
  95                 ATH_WRITE_REG(AR71XX_RST_WDOG_TIMER, timer_val);
  96                 wmb();
  97                 DELAY(100);
  98
  99                 /*
 100                  * And now, arm.
 101                  */
 102                 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, action);
 103                 sc->armed = 1;
 104                 *error = 0;
 105         } else {
 106                 if (sc->debug)
 107                         device_printf(sc->dev, "%s: disarming\n", __func__);
 108                 if (sc->armed) {
 109                         ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL,
 110                             RST_WDOG_ACTION_NOACTION);
 111                         sc->armed = 0;
 112                 }
 113         }
 114 }
 115
 116 static int
 117 ar71xx_wdog_probe(device_t dev)
 118 {
 119
 120         device_set_desc(dev, "Atheros AR71XX watchdog timer");
 121         return (BUS_PROBE_NOWILDCARD);
 122 }
 123
 124 static void
 125 ar71xx_wdog_sysctl(device_t dev)
 126 {
 127         struct ar71xx_wdog_softc *sc = device_get_softc(dev);
 128
 129         struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->dev);
 130         struct sysctl_oid *tree = device_get_sysctl_tree(sc->dev);
 131
 132         SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
 133                 "debug", CTLFLAG_RW, &sc->debug, 0,
 134                 "enable watchdog debugging");
 135         SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
 136                 "nmi", CTLFLAG_RW, &sc->watchdog_nmi, 0,
 137                 "watchdog triggers NMI instead of reset");
 138         SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
 139                 "armed", CTLFLAG_RD, &sc->armed, 0,
 140                 "whether the watchdog is armed");
 141         SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
 142                 "reboot_from_watchdog", CTLFLAG_RD, &sc->reboot_from_watchdog, 0,
 143                 "whether the system rebooted from the watchdog");
 144 }
 145
 146 static int
 147 ar71xx_wdog_attach(device_t dev)
 148 {
 149         struct ar71xx_wdog_softc *sc = device_get_softc(dev);
 150
 151         /* Initialise */
 152         sc->reboot_from_watchdog = 0;
 153         sc->armed = 0;
 154         sc->debug = 0;
 155
 156         if (ATH_READ_REG(AR71XX_RST_WDOG_CONTROL) & RST_WDOG_LAST) {
 157                 device_printf (dev,
 158                     "Previous reset was due to watchdog timeout\n");
 159                 sc->reboot_from_watchdog = 1;
 160         }
 161
 162         ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
 163
 164         sc->dev = dev;
 165         EVENTHANDLER_REGISTER(watchdog_list, ar71xx_wdog_watchdog_fn, sc, 0);
 166         ar71xx_wdog_sysctl(dev);
 167
 168         return (0);
 169 }
 170
 171 static device_method_t ar71xx_wdog_methods[] = {
 172         DEVMETHOD(device_probe, ar71xx_wdog_probe),
 173         DEVMETHOD(device_attach, ar71xx_wdog_attach),
 174         {0, 0},
 175 };
 176
 177 static driver_t ar71xx_wdog_driver = {
 178         "ar71xx_wdog",
 179         ar71xx_wdog_methods,
 180         sizeof(struct ar71xx_wdog_softc),
 181 };
 182 static devclass_t ar71xx_wdog_devclass;
 183
 184 DRIVER_MODULE(ar71xx_wdog, nexus, ar71xx_wdog_driver, ar71xx_wdog_devclass, 0, 0);