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//==========================================================================

//

//      io/watchdog/emulate.cxx

//

//      Watchdog implementation emulation

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

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//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   nickg

// Contributors:        nickg

// Date:        1998-07-29

// Purpose:     Watchdog class implementation

// Description: Contains an implementation of the Watchdog class for use

//              when there is no hardware watchdog timer. Instead it is

//              emulated using an Alarm object.

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/watchdog.h>           // watchdog configuration file

#include <pkgconf/kernel.h>             // Kernel config

#include <cyg/kernel/ktypes.h>          // base kernel types

#include <cyg/infra/cyg_trac.h>         // tracing macros

#include <cyg/infra/cyg_ass.h>          // assertion macros

#include <cyg/kernel/instrmnt.h>        // instrumentation

#include <cyg/kernel/clock.hxx>         // clock and alarm

#include <cyg/kernel/sched.hxx>         // scheduler

#include <cyg/io/watchdog.hxx>          // watchdog API

#include <cyg/kernel/sched.inl>         // scheduler inlines

// -------------------------------------------------------------------------

// Forward definitions

static cyg_alarm_fn    watchdog_alarm;

// -------------------------------------------------------------------------

// Statics

static Cyg_Alarm alarm( Cyg_Clock::real_time_clock, watchdog_alarm, 0 );

// One second's worth of ticks.

static cyg_tick_count one_sec;

// -------------------------------------------------------------------------

// HW init

void

Cyg_Watchdog::init_hw(void)

{

    CYG_REPORT_FUNCTION();

    Cyg_Clock::cyg_resolution res = Cyg_Clock::real_time_clock->get_resolution();

    one_sec             = ( res.divisor * 1000000000LL ) / res.dividend ;

    resolution          = 1000000000LL;

    CYG_REPORT_RETURN();

}

// -------------------------------------------------------------------------

// Start the watchdog running.

void Cyg_Watchdog::start()

{

    CYG_REPORT_FUNCTION();

    Cyg_Clock::cyg_resolution res = Cyg_Clock::real_time_clock->get_resolution();

    // Set alarm to a one second single-shot trigger

    alarm.initialize( Cyg_Clock::real_time_clock->current_value() + one_sec, 0 );

    CYG_REPORT_RETURN();

}

// -------------------------------------------------------------------------

// Reset watchdog timer. This needs to be called regularly to prevent

// the watchdog firing.

void Cyg_Watchdog::reset()

{

    CYG_REPORT_FUNCTION();

    Cyg_Clock::cyg_resolution res = Cyg_Clock::real_time_clock->get_resolution();

    Cyg_Scheduler::lock();

    // Set alarm to a one second single-shot trigger

    alarm.initialize( Cyg_Clock::real_time_clock->current_value() + one_sec, 0 );

    Cyg_Scheduler::unlock();

    CYG_REPORT_RETURN();

}

// -------------------------------------------------------------------------

// Alarm function

void watchdog_alarm( Cyg_Alarm *a, CYG_ADDRWORD data)

{

    CYG_REPORT_FUNCTION();

    // Disable alarm just in case

    alarm.disable();

    Cyg_Watchdog::watchdog.trigger();

}

// -------------------------------------------------------------------------

// EOF watchdog/emulate.cxx