sys/arch/arm/ep93xx/epwdog.c

   1 /*      $NetBSD: epwdog.c,v 1.2 2006/03/26 04:38:52 thorpej Exp $       */
   2
   3 /*
   4  * Copyright (c) 2005 HAMAJIMA Katsuomi. All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __KERNEL_RCSID(0, "$NetBSD: epwdog.c,v 1.2 2006/03/26 04:38:52 thorpej Exp $");
  30
  31 #include <sys/param.h>
  32 #include <sys/systm.h>
  33 #include <sys/kernel.h>
  34 #include <sys/device.h>
  35 #include <machine/bus.h>
  36 #include <arm/ep93xx/ep93xxvar.h>
  37 #include <arm/ep93xx/epsocvar.h>
  38 #include <arm/ep93xx/epwdogreg.h>
  39 #include <arm/ep93xx/epwdogvar.h>
  40
  41 struct epwdog_softc {
  42         struct device           sc_dev;
  43         bus_space_tag_t         sc_iot;
  44         bus_space_handle_t      sc_ioh;
  45 };
  46
  47 static int epwdog_match(struct device *, struct cfdata *, void *);
  48 static void epwdog_attach(struct device *, struct device *, void *);
  49
  50 CFATTACH_DECL(epwdog, sizeof(struct epwdog_softc),
  51               epwdog_match, epwdog_attach, NULL, NULL);
  52
  53 static struct epwdog_softc *the_epwdog_sc = 0;
  54
  55 static int
  56 epwdog_match(struct device *parent, struct cfdata *match, void *aux)
  57 {
  58         return 1;
  59 }
  60
  61 static void
  62 epwdog_attach(struct device *parent, struct device *self, void *aux)
  63 {
  64         struct epwdog_softc *sc = (struct epwdog_softc*)self;
  65         struct epsoc_attach_args *sa = aux;
  66
  67         printf("\n");
  68         sc->sc_iot = sa->sa_iot;
  69
  70         if (bus_space_map(sa->sa_iot, sa->sa_addr,
  71                           sa->sa_size, 0, &sc->sc_ioh)){
  72                 printf("%s: Cannot map registers", self->dv_xname);
  73                 return;
  74         }
  75
  76         if (!the_epwdog_sc)
  77                 the_epwdog_sc = sc;
  78 #ifdef DIAGNOSTIC
  79         else
  80                 printf("%s is already configured\n", sc->sc_dev.dv_xname);
  81 #endif
  82 }
  83
  84 int
  85 epwdog_reset(void)
  86 {
  87         struct epwdog_softc *sc = the_epwdog_sc;
  88
  89 #ifdef DIAGNOSTIC
  90         if (!sc) {
  91                 printf("epwdog not configured\n");
  92                 return (ENXIO);
  93         }
  94 #endif
  95
  96         bus_space_write_2(sc->sc_iot, sc->sc_ioh,
  97                           EP93XX_WDOG_Ctrl, EP93XX_WDOG_DISABLE);
  98         splhigh();
  99         bus_space_write_2(sc->sc_iot, sc->sc_ioh,
 100                           EP93XX_WDOG_Ctrl, EP93XX_WDOG_ENABLE);
 101         while (1);
 102
 103         return 0; /* not reached */
 104 }