drv/wdt.h

   1 /*!
   2  * \file
   3  * <!--
   4  * Copyright 2004 Develer S.r.l. (http://www.develer.com/)
   5  * This file is part of DevLib - See README.devlib for information.
   6  * -->
   7  *
   8  * \version $Id$
   9  *
  10  * \author Bernardo Innocenti <bernie@develer.com>
  11  *
  12  * \brief Watchdog interface
  13  */
  14
  15 /*#*
  16  *#* $Log$
  17  *#* Revision 1.7  2005/11/27 03:58:40  bernie
  18  *#* Add POSIX timer emulator.
  19  *#*
  20  *#* Revision 1.6  2005/11/27 03:03:08  bernie
  21  *#* Add Qt support hack.
  22  *#*
  23  *#* Revision 1.5  2005/11/04 16:20:02  bernie
  24  *#* Fix reference to README.devlib in header.
  25  *#*
  26  *#* Revision 1.4  2005/04/12 01:37:17  bernie
  27  *#* Prevent warning when watchdog is disabled.
  28  *#*
  29  *#* Revision 1.3  2005/04/11 19:10:28  bernie
  30  *#* Include top-level headers from cfg/ subdir.
  31  *#*
  32  *#* Revision 1.2  2004/11/16 21:02:07  bernie
  33  *#* Make driver optional; mark AVR specific parts as such.
  34  *#*
  35  *#* Revision 1.1  2004/10/26 08:34:47  bernie
  36  *#* New DevLib module.
  37  *#*
  38  *#*/
  39 #ifndef DRV_WDT_H
  40 #define DRV_WDT_H
  41
  42 #include <appconfig.h>
  43 #include <cfg/compiler.h> // INLINE
  44
  45 /* Configury sanity check */
  46 #if !defined(CONFIG_WATCHDOG) || (CONFIG_WATCHDOG != 0 && CONFIG_WATCHDOG != 1)
  47         #error CONFIG_WATCHDOG must be defined to either 0 or 1
  48 #endif
  49
  50 #if CONFIG_WATCHDOG
  51         #include <cfg/cpu.h>
  52         #include <cfg/os.h>
  53
  54         #if OS_QT
  55                 #include <qapplication.h>
  56         #elif OS_POSIX
  57                 #include <sys/select.h>
  58         #elif CPU_AVR
  59                 #include <avr/io.h>
  60                 #include <cfg/macros.h> // BV()
  61         #else
  62                 #error unknown CPU
  63         #endif
  64 #endif /* CONFIG_WATCHDOG */
  65
  66 /*!
  67  * Reset the watchdog timer.
  68  */
  69 INLINE void wdt_reset(void)
  70 {
  71 #if CONFIG_WATCHDOG
  72         #if OS_QT
  73                 // Let Qt handle events
  74                 ASSERT(qApp);
  75                 qApp->processEvents();
  76         #elif OS_POSIX
  77                 static struct timeval tv = { 0, 0 };
  78                 select(0, NULL, NULL, NULL, &tv);
  79         #elif CPU_AVR
  80                 __asm__ __volatile__ ("wdr");
  81         #else
  82                 #error unknown CPU
  83         #endif
  84 #endif /* CONFIG_WATCHDOG */
  85 }
  86
  87 /*!
  88  * Set watchdog timer timeout.
  89  *
  90  * \param timeout  0: 16.3ms, 7: 2.1s
  91  */
  92 INLINE void wdt_init(uint8_t timeout)
  93 {
  94 #if CONFIG_WATCHDOG
  95         #if OS_QT
  96                 // Create a dummy QApplication object
  97                 if (!qApp)
  98                 {
  99                         int argc;
 100                         new QApplication(argc, (char **)NULL);
 101                 }
 102                 (void)timeout;
 103         #elif OS_POSIX
 104                 (void)timeout; // NOP
 105         #elif CPU_AVR
 106                 WDTCR |= BV(WDCE) | BV(WDE);
 107                 WDTCR = timeout;
 108         #else
 109                 #error unknown CPU
 110         #endif
 111 #else
 112         (void)timeout;
 113 #endif /* CONFIG_WATCHDOG */
 114 }
 115
 116 INLINE void wdt_start(void)
 117 {
 118 #if CONFIG_WATCHDOG
 119         #if OS_QT
 120                 // NOP
 121         #elif OS_POSIX
 122                 // NOP
 123         #elif CPU_AVR
 124                 WDTCR |= BV(WDE);
 125         #else
 126                 #error unknown CPU
 127         #endif
 128 #endif /* CONFIG_WATCHDOG */
 129 }
 130
 131 INLINE void wdt_stop(void)
 132 {
 133 #if CONFIG_WATCHDOG
 134         #if OS_QT
 135                 // NOP
 136         #elif OS_POSIX
 137                 // NOP
 138         #elif CPU_AVR
 139                 WDTCR |= BV(WDCE) | BV(WDE);
 140                 WDTCR &= ~BV(WDE);
 141         #else
 142                 #error unknown CPU
 143         #endif
 144 #endif /* CONFIG_WATCHDOG */
 145 }
 146
 147 #endif /* DRV_WDT_H */