sys/arch/arm/xscale/i80321_wdog.c

   1 /*      $NetBSD: i80321_wdog.c,v 1.7 2005/12/11 12:16:51 christos Exp $ */
   2
   3 /*
   4  * Copyright (c) 2002 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /*
  39  * Watchdog timer support for the Intel i80321 I/O processor.
  40  */
  41
  42 #include <sys/cdefs.h>
  43 __KERNEL_RCSID(0, "$NetBSD: i80321_wdog.c,v 1.7 2005/12/11 12:16:51 christos Exp $");
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/device.h>
  48 #include <sys/wdog.h>
  49
  50 #include <machine/bus.h>
  51 #include <arm/cpufunc.h>
  52
  53 #include <arm/xscale/i80321reg.h>
  54 #include <arm/xscale/i80321var.h>
  55
  56 #include <dev/sysmon/sysmonvar.h>
  57
  58 struct iopwdog_softc {
  59         struct device sc_dev;
  60         struct sysmon_wdog sc_smw;
  61         int sc_wdog_armed;
  62         int sc_wdog_period;
  63 };
  64
  65 static inline void
  66 wdtcr_write(uint32_t val)
  67 {
  68
  69         __asm volatile("mcr p6, 0, %0, c7, c1, 0"
  70                 :
  71                 : "r" (val));
  72 }
  73
  74 static int
  75 iopwdog_tickle(struct sysmon_wdog *smw)
  76 {
  77
  78         wdtcr_write(WDTCR_ENABLE1);
  79         wdtcr_write(WDTCR_ENABLE2);
  80         return (0);
  81 }
  82
  83 static int
  84 iopwdog_setmode(struct sysmon_wdog *smw)
  85 {
  86         struct iopwdog_softc *sc = smw->smw_cookie;
  87
  88         if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
  89                 /* The i80321 watchdog can't be disarmed once armed. */
  90                 if (sc->sc_wdog_armed)
  91                         return (EOPNOTSUPP);
  92         } else {
  93                 if (smw->smw_period == WDOG_PERIOD_DEFAULT)
  94                         smw->smw_period = sc->sc_wdog_period;
  95                 else if (smw->smw_period != sc->sc_wdog_period) {
  96                         /* Can't change the i80321 watchdog period. */
  97                         return (EOPNOTSUPP);
  98                 }
  99                 sc->sc_wdog_armed = 1;
 100                 /* Watchdog is armed by tickling it. */
 101                 iopwdog_tickle(smw);
 102         }
 103         return (0);
 104 }
 105
 106 static int
 107 iopwdog_match(struct device *parent, struct cfdata *cf, void *aux)
 108 {
 109         struct iopxs_attach_args *ia = aux;
 110
 111         if (strcmp(cf->cf_name, ia->ia_name) == 0)
 112                 return (1);
 113
 114         return (0);
 115 }
 116
 117 static void
 118 iopwdog_attach(struct device *parent, struct device *self, void *aux)
 119 {
 120         struct iopwdog_softc *sc = (void *) self;
 121
 122         /*
 123          * XXX Should compute the period based on processor speed.
 124          * For a 600MHz XScale core, the wdog must be tickled approx.
 125          * every 7 seconds.
 126          */
 127         sc->sc_wdog_period = 7;
 128
 129         aprint_naive(": Watchdog timer\n");
 130         aprint_normal(": %d second period\n", sc->sc_wdog_period);
 131
 132         sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
 133         sc->sc_smw.smw_cookie = sc;
 134         sc->sc_smw.smw_setmode = iopwdog_setmode;
 135         sc->sc_smw.smw_tickle = iopwdog_tickle;
 136         sc->sc_smw.smw_period = sc->sc_wdog_period;
 137
 138         if (sysmon_wdog_register(&sc->sc_smw) != 0)
 139                 aprint_error("%s: unable to register with sysmon\n",
 140                     sc->sc_dev.dv_xname);
 141 }
 142
 143 CFATTACH_DECL(iopwdog, sizeof(struct iopwdog_softc),
 144     iopwdog_match, iopwdog_attach, NULL, NULL);