ppc555timer.c

IXP425的BSP代码

      return (OK);
      }

   if (!sysClkRunning)          /* don't have any auxiliary clock ! */
      return (ERROR);

   sysTimestampRunning = TRUE;

   return (OK);
   }

/*******************************************************************************
*
* sysTimestampDisable - disable a timestamp timer interrupt
*
* This routine disables timestamp timer interrupts.
*
* NOTE: This routine has no effect, since the CPU decrementer has no
* timestamp timer interrupt.
*
* RETURNS: OK, always.
*
* SEE ALSO: sysTimestampEnable()
*/

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

    return (OK);
    }

/*******************************************************************************
*
* sysTimestampPeriod - get the period of a timestamp timer 
*
* This routine gets 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 gets the frequency of the timer clock, in ticks per 
* second.  The rate of the timestamp timer is set explicitly by the 
* hardware and typically cannot be altered.
*
* NOTE: Because the PowerPC decrementer clock serves as the timestamp timer,
* the decrementer clock frequency is also the timestamp timer frequency.
*
* RETURNS: The timestamp timer clock frequency, in ticks per second.
*/

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

/*******************************************************************************
*
* 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 it 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 - (INT32) vxDecGet());
    }

/*******************************************************************************
*
* sysTimestampLock - lock interrupts and get the timestamp timer tick count
*
* This routine locks interrupts when 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 it by the return of
* sysTimestampFreq().
*
* If interrupts are already locked, sysTimestamp() should be
* used instead.
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestampFreq(), sysTimestamp()
*/

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

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

    return (decCountVal - currentDecValue);
    }

#endif  /* INCLUDE_TIMESTAMP */

/*******************************************************************************
*
* sysAuxClkInt - handle an auxiliary clock interrupt
*
* This routine handles an auxiliary clock interrupt.  It acknowledges the
* interrupt and calls the routine installed by sysAuxClkConnect().
*
* RETURNS: N/A
*/

void sysAuxClkInt (void)
    {
    UINT32 imemBase = vxImemBaseGet();  /* internal memory Base Address */

    /* read PS bit in PISCR, and then reset it to terminate int request */
    if(*PISCR(imemBase) & PISCR_PS)
            *PISCR(imemBase) |= PISCR_PS;

    /* call auxiliary clock service routine */
    if (sysAuxClkRoutine != NULL)
	(*sysAuxClkRoutine) (sysAuxClkArg);
    }

/*******************************************************************************
*
* sysAuxClkConnect - connect a routine to the auxiliary clock interrupt
*
* This routine specifies the interrupt service routine to be called at each
* auxiliary clock interrupt.  It does not enable auxiliary clock interrupts.
*
* RETURNS: OK, or ERROR if the routine cannot be connected to the interrupt.
*
* SEE ALSO: intConnect(), sysAuxClkEnable()
*/

STATUS sysAuxClkConnect
    (
    FUNCPTR routine,    /* routine called at each aux clock interrupt */
    int arg             /* argument to auxiliary clock interrupt routine */
    )
    {

    /* connect the ISR to PIT exception */
    sysAuxClkRoutine	= routine;
    sysAuxClkArg	= arg;

    return (OK);
    }

/*******************************************************************************
*
* sysAuxClkDisable - turn off auxiliary clock interrupts
*
* This routine disables auxiliary clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysAuxClkEnable()
*/

void sysAuxClkDisable (void)
    {
    UINT32 imemBase = vxImemBaseGet();  /* internal memory Base Address */

    if (sysAuxClkRunning)
        {
        *PISCR(imemBase) &= ~PISCR_PIE;      /* disable PIT interrupts */
        *PISCR(imemBase) &= ~PISCR_PTE;       /* stop PIT */

	intDisable (PIT_INT_LVL); /* disable int controller PIT level */

        sysAuxClkRunning = FALSE;
        }
    }

/*******************************************************************************
*
* sysAuxClkEnable - turn on auxiliary clock interrupts
*
* This routine enables auxiliary clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysAuxClkConnect(), sysAuxClkDisable(), sysAuxClkRateSet()
*/

void sysAuxClkEnable (void)
    {
    UINT32 imemBase = vxImemBaseGet();  /* internal memory Base Address */

    if (!sysAuxClkIntConnected)
        {
	*PISCR(imemBase) |= PISCR_PIRQ;	/* set PIT int level */

        /* connect sysAuxClkInt to PIT interrupt */
        (void) intConnect (INUM_TO_IVEC(PIT_INT_LVL), (VOIDFUNCPTR) sysAuxClkInt, NULL);
        
        sysAuxClkIntConnected = TRUE;
        }

    if (!sysAuxClkRunning)
        {
        /* clear any pendding PIT int request */
        if(*PISCR(imemBase) & PISCR_PS)
            *PISCR(imemBase) |= PISCR_PS;

        /* set clock divider */
	*SCCR(imemBase) &= ~SCCR_RTDIV_MSK;
	*SCCR(imemBase) |= SCCR_RTDIV;

        /* set counter preload value */
        *PITC(imemBase) = (PIT_CLOCK_FREQ / sysAuxClkTicksPerSecond) << 16; 

        *PISCR(imemBase) |= PISCR_PTE;      /* start PIT */
        *PISCR(imemBase) |= PISCR_PIE;      /* enable PIT interrupts */

	intEnable (PIT_INT_LVL); /* enable int controller PIT level */

        sysAuxClkRunning = TRUE;
        }
    }

/*******************************************************************************
*
* sysAuxClkRateGet - get the auxiliary clock rate
*
* This routine returns the interrupt rate of the auxiliary clock.
*
* RETURNS: The number of ticks per second of the auxiliary clock.
*
* SEE ALSO: sysAuxClkEnable(), sysAuxClkRateSet()
*/

int sysAuxClkRateGet (void)
    {
    return (sysAuxClkTicksPerSecond);
    }

/*******************************************************************************
*
* sysAuxClkRateSet - set the auxiliary clock rate
*
* This routine sets the interrupt rate of the auxiliary clock.  It does not
* enable auxiliary clock interrupts.
*
* RETURNS: OK, or ERROR if the tick rate is invalid or the timer cannot be set.
*
* SEE ALSO: sysAuxClkEnable(), sysAuxClkRateGet()
*/

STATUS sysAuxClkRateSet
    (
    int ticksPerSecond  /* number of clock interrupts per second */
    )
    {
    /* return ERROR if rate is not supported */
    if (ticksPerSecond < AUX_CLK_RATE_MIN || ticksPerSecond > AUX_CLK_RATE_MAX)
        return (ERROR);

    sysAuxClkTicksPerSecond = ticksPerSecond;

    if (sysAuxClkRunning)
        {
        sysAuxClkDisable ();
        sysAuxClkEnable ();
        }

    return (OK);
    }