FreeBSD/Linux Kernel Cross Reference
sys/arm/xscale/i80321/i80321_wdog.c

     /*      $NetBSD: i80321_wdog.c,v 1.6 2003/07/15 00:24:54 lukem Exp $    */
     
     /*-
      * Copyright (c) 2005 Olivier Houchard
      * Copyright (c) 2002 Wasabi Systems, Inc.
      * All rights reserved.
      *
      * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      *
     * 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, 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.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed for the NetBSD Project by
     *      Wasabi Systems, Inc.
     * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     *    or promote products derived from this software without specific prior
     *    written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
     * 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 timer support for the Intel i80321 I/O processor.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/6.4/sys/arm/xscale/i80321/i80321_wdog.c 168086 2007-03-30 19:17:37Z n_hibma $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/watchdog.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    
    #include <machine/bus.h>
    #include <machine/cpufunc.h>
    #include <machine/machdep.h>
    
    #include <arm/xscale/i80321/i80321reg.h>
    #include <arm/xscale/i80321/i80321var.h>
    
    
    struct iopwdog_softc {
            device_t dev;
            int armed;
            int wdog_period;
    };
    
    static __inline void
    wdtcr_write(uint32_t val)
    {
    
            __asm __volatile("mcr p6, 0, %0, c7, c1, 0"
                    :
                    : "r" (val));
    }
    
    static void
    iopwdog_tickle(void *arg)
    {
            struct iopwdog_softc *sc = arg;
    
            if (!sc->armed)
                    return;
            wdtcr_write(WDTCR_ENABLE1);
            wdtcr_write(WDTCR_ENABLE2);
    }
    
    static int
    iopwdog_probe(device_t dev)
    {
            struct iopwdog_softc *sc = device_get_softc(dev);
            char buf[128];
    
            /*
             * XXX Should compute the period based on processor speed.
             * For a 600MHz XScale core, the wdog must be tickled approx.
             * every 7 seconds.
             */
    
            sc->wdog_period = 7;
           sprintf(buf, "i80321 Watchdog, must be tickled every %d seconds",
               sc->wdog_period);
           device_set_desc_copy(dev, buf);
   
           return (0);
   }
   
   static void
   iopwdog_watchdog_fn(void *private, u_int cmd, int *error)
   {
           struct iopwdog_softc *sc = private;
   
           cmd &= WD_INTERVAL;
           if (cmd > 0 && cmd <= 63
               && (uint64_t)1 << (cmd & WD_INTERVAL) <=
                  (uint64_t)sc->wdog_period * 1000000000) {
                   /* Valid value -> Enable watchdog */
                   iopwdog_tickle(sc);
                   sc->armed = 1;
                   *error = 0;
           } else {
                   /* Can't disable this watchdog! */
                   if (sc->armed)
                           *error = EOPNOTSUPP;
           }
   }
   
   static int
   iopwdog_attach(device_t dev)
   {
           struct iopwdog_softc *sc = device_get_softc(dev);
           
           sc->dev = dev;
           sc->armed = 0;
           EVENTHANDLER_REGISTER(watchdog_list, iopwdog_watchdog_fn, sc, 0);
           return (0);
   }
   
   static device_method_t iopwdog_methods[] = {
           DEVMETHOD(device_probe, iopwdog_probe),
           DEVMETHOD(device_attach, iopwdog_attach),
           {0, 0},
   };
   
   static driver_t iopwdog_driver = {
           "iopwdog",
           iopwdog_methods,
           sizeof(struct iopwdog_softc),
   };
   static devclass_t iopwdog_devclass;
   
   DRIVER_MODULE(iopwdog, iq, iopwdog_driver, iopwdog_devclass, 0, 0);

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