m85xxtimer.c

Freescale MPC85xx BSP (8555/8541)。绝对可用的。

* sysWdtConnect - connect a routine to the watchdog interrupt
*
* This routine specifies the interrupt service routine to be called at
* each watchdog interrupt. It does not enable watchdog interrupts.
*
* RETURNS: OK, or ERROR if the routine cannot be connected to the
* watchdog
* interrupt.
*
* SEE ALSO: excIntCrtConnect(), sysWdtEnable()
*/

STATUS sysWdtConnect
    (
    FUNCPTR     routine, /* routine called at each watchdog interrupt */
    int         arg      /* argument with which to call routine        */
    )
    {
    /* connect the routine to the WDT vector */

    excIntCrtConnect ((VOIDFUNCPTR *) _EXC_OFF_WD, (VOIDFUNCPTR) sysWdtInt);

    sysWdtRoutine    = routine;
    sysWdtArg        = arg;

    return (OK);
    }

/***************************************************************************
*
* sysWdtEnable - turn on watchdog interrupts
*
* This routine enables watchdog interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysWdtConnect(), sysWdtDisable(), sysWdtRateSet()
*/

void sysWdtEnable (void)
    {
    if (!sysWdtRunning)
        {
        /* clear the pending WDT interrupt */

        vxTsrSet (TSR_WIS);

        /* program TCR with the WDT period */

        vxTcrSet ((vxTcrGet() & ~(TCR_WP|TCR_WP_EXT)) | wdtPeriodMask);

        /* Enable the WDT interrupt */

        vxTcrSet (vxTcrGet() | TCR_WIE);

        /* Enable critical interrupt */

        vxMsrSet (vxMsrGet() | _PPC_MSR_CE);

        /* set the running flag */

        sysWdtRunning = TRUE;
        }
    }

/***************************************************************************
*
* sysWdtDisable - turn off watchdog interrupts
*
* This routine disables watchdog interrupts. This routine does not
* disable critical interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysWdtEnable()
*/

void sysWdtDisable (void)
    {
    if (sysWdtRunning)
        {
        /* disable the WDT interrupt */

        vxTcrSet (vxTcrGet() & ~ (TCR_WIE));

        /* clear the pending WDT interrupt */

        vxTsrSet (TSR_WIS);

        /* reset the running flag */

        sysWdtRunning = FALSE;
        }
    }

/***************************************************************************
*
* sysWdtRateGet - get the watchdog timer rate
*
* This routine returns the interrupt rate of the watchdog timer.
*
* RETURNS: The number of watchdog interrupts per second.
*
* SEE ALSO: sysWdtEnable(), sysWdtRateSet()
*/

int sysWdtRateGet (void)
    {
    return (sysWdtTicksPerSecond);
    }

/***************************************************************************
*
* sysWdtRateSet - set the watchdog timer rate
*
* This routine sets the interrupt rate of the watchdog timer. It does
* not enable watchdog interrupts.
*
* RETURNS: OK, or ERROR if the tick rate is invalid or the timer cannot
* be set.
*
* SEE ALSO: sysWdtEnable(), sysWdtRateGet()
*/

STATUS sysWdtRateSet
    (
    int         ticksPerSecond  /* number of clock interrupts per second */
    )
    {
    int ix;
    int jx = 0;
    unsigned long long wdtPeriod;

    /*
     * compute the WDT period.
     * only 4 values are possible (cf wdtTable[]). The closest value to
     * <ticksPerSecond> is being used.
     */

    if ((ticksPerSecond < (int) WDT_RATE_MIN) ||
        (ticksPerSecond > (int) WDT_RATE_MAX))
        return (ERROR);

    wdtPeriod = (sysTimerClkFreq >> 1) / ticksPerSecond;

    /* get the closest value to ticksPerSecond supported by the WDT */

    for (ix = 0; ix < (int) NELEMENTS (wdtTable); ix++)
        {
        if (wdtPeriod <= wdtTable [ix].wdtPeriod)
            {
            if (ix != 0)
                if ( wdtPeriod <
                     ((wdtTable [ix].wdtPeriod + wdtTable [ix-1].wdtPeriod)/2))
                    jx = ix-1;
                else
                    jx = ix;
            else
                jx = ix;
            break;
            }
        if (ix == NELEMENTS (wdtTable) - 1)
            jx = ix;
        }
    wdtPeriod = wdtTable [jx].wdtPeriod;        /* actual period of the WDT */
    wdtPeriodMask = wdtTable [jx].fpMask;       /* Mask to program TCR with */

    /* save the clock speed */

    sysWdtTicksPerSecond = (sysTimerClkFreq >> 1) / wdtPeriod;

    return (OK);
    }


#ifdef  INCLUDE_TIMESTAMP

/***************************************************************************
*
* sysTimestampConnect - connect a user routine to a timestamp timer interrupt
*
* This routine specifies the user interrupt routine to be called at each
* timestamp timer interrupt. In this case, however, the timestamp timer
* interrupt is not used since the on-chip timer is also used by the
* system clock.
*
* RETURNS: OK, or ERROR if sysTimestampInt() interrupt handler is not
* used.
*/

STATUS sysTimestampConnect
    (
    FUNCPTR     routine, /* routine called at each timestamp timer interrupt */
    int         arg      /* argument with which to call routine */
    )
    {
    return (ERROR);
    }

/***************************************************************************
*
* sysTimestampEnable - initialize and enable a timestamp timer
*
* This routine disables the timestamp timer interrupt and initializes
* the counter registers. If the timestamp timer is already running, this
* routine merely resets the timer counter.
*
* This routine does not initialize the timer rate. The rate of the
* timestamp timer should be set explicitly in the BSP by sysHwInit().
*
* RETURNS: OK, or ERROR if the timestamp timer cannot be enabled.
*/

STATUS sysTimestampEnable (void)
   {
   if (sysTimestampRunning)
      {
      return (OK);
      }

   if (!sysClkRunning)
      return (ERROR);

   sysTimestampRunning = TRUE;

   return (OK);
   }

/*******************************************************************************
*
* sysTimestampDisable - disable a timestamp timer
*
* This routine disables the timestamp timer. Interrupts are not
* disabled; however, because the tick counter does not increment after
* the timestamp timer is disabled, interrupts no longer are generated.
*
* RETURNS: OK, or ERROR if the timestamp timer cannot be disabled.
*/

STATUS sysTimestampDisable (void)
    {
    if (sysTimestampRunning)
        sysTimestampRunning = FALSE;

    return (OK);
    }

/*******************************************************************************
*
* sysTimestampPeriod - get a timestamp timer period
*
* This routine specifies the period of the timestamp timer, in ticks.
* The period, or terminal count, is the number of ticks to which the
* timestamp timer counts before rolling over and restarting the counting
* process.
*
* RETURNS: The period of the timestamp timer in counter ticks.
*/

UINT32 sysTimestampPeriod (void)
    {
    /*
     * The period of the timestamp depends on the clock rate of the
     * on-chip timer (ie the Decrementer reload value).
     */

    return (decCountVal);
    }

/*******************************************************************************
*
* sysTimestampFreq - get a timestamp timer clock frequency
*
* This routine specifies the frequency of the timer clock, in ticks per
* second. The rate of the timestamp timer should be set explicitly in
* the BSP by sysHwInit().
*
* RETURNS: The timestamp timer clock frequency, in ticks per second.
*/

UINT32 sysTimestampFreq (void)
    {
    return (sysTimerClkFreq);
    }

/*******************************************************************************
*
* sysTimestamp - get a timestamp timer tick count
*
* This routine returns the current value of the timestamp timer tick
* counter. The tick count can be converted to seconds by dividing by the
* return of sysTimestampFreq().
*
* This routine should be called with interrupts locked. If interrupts
* are not locked, sysTimestampLock() should be used instead.
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestampFreq(), sysTimestampLock()
*/

UINT32 sysTimestamp (void)
    {
    return (decCountVal - (UINT32) vxDecGet());
    }

/***************************************************************************
*
* sysTimestampLock - lock an interrupt and get a timestamp timer tick count
*
* This routine locks interrupts when stop the tick counter must be
* stopped in order to read it or when two independent counters must be
* read. It then returns the current value of the timestamp timer tick
* counter.
*
* The tick count can be converted to seconds by dividing by the return
* of sysTimestampFreq().
*
* If interrupts are already locked, sysTimestamp() should be used
* instead.
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestamp()
*/

UINT32 sysTimestampLock (void)
    {
    UINT32 currentDecValue;
    int oldLevel;

    oldLevel = intLock ();                              /* LOCK INTERRUPT */
    currentDecValue = vxDecGet();
    intUnlock (oldLevel);                               /* UNLOCK INTERRUPT */

    return (decCountVal - currentDecValue);
    }

#endif  /* INCLUDE_TIMESTAMP */