cpu/msp430/watchdog.c

   1 /*
   2  * Copyright (c) 2005, Swedish Institute of Computer Science
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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  * This file is part of the Contiki operating system.
  30  *
  31  * @(#)$Id: watchdog.c,v 1.8 2010/04/04 12:30:10 adamdunkels Exp $
  32  */
  33 #include <io.h>
  34 #include <signal.h>
  35 #include "dev/watchdog.h"
  36
  37 static int stopped = 0;
  38 /*---------------------------------------------------------------------------*/
  39 static void
  40 printchar(char c)
  41 {
  42   /* Transmit the data. */
  43   TXBUF1 = c;
  44
  45   /* Loop until the transmission buffer is available. */
  46   while((IFG2 & UTXIFG1) == 0);
  47
  48 }
  49 /*---------------------------------------------------------------------------*/
  50 static void
  51 hexprint(uint8_t v)
  52 {
  53   const char hexconv[] = "0123456789abcdef";
  54   printchar(hexconv[v >> 4]);
  55   printchar(hexconv[v & 0x0f]);
  56 }
  57 /*---------------------------------------------------------------------------*/
  58 static void
  59 printstring(char *s)
  60 {
  61   while(*s) {
  62     printchar(*s++);
  63   }
  64 }
  65 /*---------------------------------------------------------------------------*/
  66 interrupt(WDT_VECTOR)
  67 watchdog_interrupt(void)
  68 {
  69   uint8_t dummy;
  70   static uint8_t *ptr;
  71   static int i;
  72
  73   ptr = &dummy;
  74
  75   printstring("Watchdog reset");
  76   /*  printstring("Watchdog reset at PC $");
  77   hexprint(ptr[3]);
  78   hexprint(ptr[2]);*/
  79   printstring("\nStack at $");
  80   hexprint(((int)ptr) >> 8);
  81   hexprint(((int)ptr) & 0xff);
  82   printstring(":\n");
  83
  84   for(i = 0; i < 64; ++i) {
  85     hexprint(ptr[i]);
  86     printchar(' ');
  87     if((i & 0x0f) == 0x0f) {
  88       printchar('\n');
  89     }
  90   }
  91   printchar('\n');
  92   watchdog_reboot();
  93 }
  94 /*---------------------------------------------------------------------------*/
  95 void
  96 watchdog_init(void)
  97 {
  98   /* The MSP430 watchdog is enabled at boot-up, so we stop it during
  99      initialization. */
 100   stopped = 0;
 101   watchdog_stop();
 102
 103   IFG1 &= ~WDTIFG;
 104   IE1 |= WDTIE;
 105 }
 106 /*---------------------------------------------------------------------------*/
 107 void
 108 watchdog_start(void)
 109 {
 110   /* We setup the watchdog to reset the device after one second,
 111      unless watchdog_periodic() is called. */
 112   stopped--;
 113   if(!stopped) {
 114     WDTCTL = WDTPW | WDTCNTCL | WDT_ARST_1000 | WDTTMSEL;
 115   }
 116 }
 117 /*---------------------------------------------------------------------------*/
 118 void
 119 watchdog_periodic(void)
 120 {
 121   /* This function is called periodically to restart the watchdog
 122      timer. */
 123   if(!stopped) {
 124     WDTCTL = (WDTCTL & 0xff) | WDTPW | WDTCNTCL | WDTTMSEL;;
 125   }
 126 }
 127 /*---------------------------------------------------------------------------*/
 128 void
 129 watchdog_stop(void)
 130 {
 131   WDTCTL = WDTPW | WDTHOLD;
 132   stopped++;
 133 }
 134 /*---------------------------------------------------------------------------*/
 135 void
 136 watchdog_reboot(void)
 137 {
 138   WDTCTL = 0;
 139 }
 140 /*---------------------------------------------------------------------------*/