FreeBSD/Linux Kernel Cross Reference
sys/mips/atheros/ar71xx_wdog.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice unmodified, this list of conditions, and the following
     *    disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /*
     * Watchdog driver for AR71xx 
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/eventhandler.h>
    #include <sys/systm.h>
    #include <sys/watchdog.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/sysctl.h>
    
    #include <mips/atheros/ar71xxreg.h>
    #include <mips/atheros/ar71xx_cpudef.h>
    
    struct ar71xx_wdog_softc {
            device_t dev;
            int armed;
            int reboot_from_watchdog;
            int watchdog_nmi;
            int debug;
    };
    
    static void
    ar71xx_wdog_watchdog_fn(void *private, u_int cmd, int *error)
    {
            struct ar71xx_wdog_softc *sc = private;
            uint64_t timer_val;
            int action;
    
            action = RST_WDOG_ACTION_RESET;
            if (sc->watchdog_nmi != 0)
                    action = RST_WDOG_ACTION_NMI;
    
            cmd &= WD_INTERVAL;
            if (sc->debug)
                    device_printf(sc->dev, "%s: : cmd: %x\n", __func__, cmd);
            if (cmd > 0) {
                    timer_val = (uint64_t)(1ULL << cmd) * ar71xx_ahb_freq() /
                        1000000000;
    
                    /*
                     * Clamp the timer value in case we overflow.
                     */
                    if (timer_val > 0xffffffff)
                            timer_val = 0xffffffff;
                    if (sc->debug)
                            device_printf(sc->dev, "%s: programming timer: %jx\n",
                                __func__, (uintmax_t) timer_val);
                    /*
                     * Make sure the watchdog is set to NOACTION and give it
                     * time to take.
                     */
                    ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
                    wmb();
                    DELAY(100);
    
                    /*
                     * Update the timer value.  It's already clamped at this
                     * point so we don't have to wrap/clamp it here.
                     */
                    ATH_WRITE_REG(AR71XX_RST_WDOG_TIMER, timer_val);
                    wmb();
                    DELAY(100);
    
                    /*
                    * And now, arm.
                    */
                   ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, action);
                   sc->armed = 1;
                   *error = 0;
           } else {
                   if (sc->debug)
                           device_printf(sc->dev, "%s: disarming\n", __func__);
                   if (sc->armed) {
                           ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL,
                               RST_WDOG_ACTION_NOACTION);
                           sc->armed = 0;
                   }
           }
   }
   
   static int
   ar71xx_wdog_probe(device_t dev)
   {
   
           device_set_desc(dev, "Atheros AR71XX watchdog timer");
           return (BUS_PROBE_NOWILDCARD);
   }
   
   static void
   ar71xx_wdog_sysctl(device_t dev)
   {
           struct ar71xx_wdog_softc *sc = device_get_softc(dev);
   
           struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->dev);
           struct sysctl_oid *tree = device_get_sysctl_tree(sc->dev);
   
           SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                   "debug", CTLFLAG_RW, &sc->debug, 0,
                   "enable watchdog debugging");
           SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                   "nmi", CTLFLAG_RW, &sc->watchdog_nmi, 0,
                   "watchdog triggers NMI instead of reset");
           SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                   "armed", CTLFLAG_RD, &sc->armed, 0,
                   "whether the watchdog is armed");
           SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                   "reboot_from_watchdog", CTLFLAG_RD, &sc->reboot_from_watchdog, 0,
                   "whether the system rebooted from the watchdog");
   }
   
   static int
   ar71xx_wdog_attach(device_t dev)
   {
           struct ar71xx_wdog_softc *sc = device_get_softc(dev);
   
           /* Initialise */
           sc->reboot_from_watchdog = 0;
           sc->armed = 0;
           sc->debug = 0;
   
           if (ATH_READ_REG(AR71XX_RST_WDOG_CONTROL) & RST_WDOG_LAST) {
                   device_printf (dev, 
                       "Previous reset was due to watchdog timeout\n");
                   sc->reboot_from_watchdog = 1;
           }
   
           ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
   
           sc->dev = dev;
           EVENTHANDLER_REGISTER(watchdog_list, ar71xx_wdog_watchdog_fn, sc, 0);
           ar71xx_wdog_sysctl(dev);
   
           return (0);
   }
   
   static device_method_t ar71xx_wdog_methods[] = {
           DEVMETHOD(device_probe, ar71xx_wdog_probe),
           DEVMETHOD(device_attach, ar71xx_wdog_attach),
           {0, 0},
   };
   
   static driver_t ar71xx_wdog_driver = {
           "ar71xx_wdog",
           ar71xx_wdog_methods,
           sizeof(struct ar71xx_wdog_softc),
   };
   static devclass_t ar71xx_wdog_devclass;
   
   DRIVER_MODULE(ar71xx_wdog, nexus, ar71xx_wdog_driver, ar71xx_wdog_devclass, 0, 0);

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