dga001timer.c

IXP425的BSP代码

* sysAuxClkEnable - turn on auxiliary clock interrupts
*
* This routine enables auxiliary clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysAuxClkConnect(), sysAuxClkDisable(), sysAuxClkRateSet()
*/
 
void sysAuxClkEnable (void)
    {
    if (!sysAuxClkRunning)
	{
	*DGA_CSR14  = (UINT32) NULL;		/* stop timer */
	*DGA_CSR15  = (UINT32) NULL;		/* clear count */
	*DGA_CSR23  = (UINT32) CSR23_TT1ICL;	/* clear interrupt */
	*DGA_CSR21 |= (UINT32) CSR21_TT1IEN;	/* enable interrupt */

	/* load compare register with the number of micro seconds and 
	 * start the counter.
	 */
	*DGA_CSR14 = (UINT32)((DGA_TICK_FREQ / auxClkTicksPerSecond - 1) | 
				CSR14_TT1CEN);
	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 (auxClkTicksPerSecond);
    }

/*******************************************************************************
*
* 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 */
    )
    {
    if (ticksPerSecond < AUX_CLK_RATE_MIN || ticksPerSecond > AUX_CLK_RATE_MAX)
	return (ERROR);
 
    auxClkTicksPerSecond = ticksPerSecond;
 
    if (sysAuxClkRunning)
	{
	sysAuxClkDisable ();
	sysAuxClkEnable ();
	}
    return (OK);
    } 
#endif	/* AUXCLK_USE_DGA001_TT1 */

#if defined(INCLUDE_TIMESTAMP) && defined(TSTAMP_USE_DGA001_TT1)
/*******************************************************************************
*
* sysTimestampInt - timestamp timer interrupt handler
*
* This rountine handles the timestamp timer interrupt.  A user routine is
* called, if one was connected by sysTimestampConnect().
*
* RETURNS: N/A   
*
* SEE ALSO: sysTimestampConnect()
*/

LOCAL void sysTimestampInt (void)
    {
    if (*DGA_CSR20 & CSR20_TT1IRQ)
	{
	*DGA_CSR23 = (UINT32)CSR23_TT1ICL;		/* clear interrupt */

	if (sysTimestampRoutine != NULL)
	    (*sysTimestampRoutine) (sysTimestampArg);	/* call user routine */
	}
    }

/*******************************************************************************
*
* sysTimestampConnect - connect a user routine to the timestamp timer interrupt
*
* This routine specifies the user interrupt routine to be called at each
* timestamp timer interrupt.  It does not enable the timestamp timer itself.
*
* 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 */
    )
    {
    sysTimestampRoutine = routine;
    sysTimestampArg     = arg;
 
    return (OK);
    }

/*******************************************************************************
*
* sysTimestampEnable - initialize and enable the timestamp timer
*
* This routine connects the timestamp timer interrupt and initializes the
* counter registers.  If the timestamp timer is already running, this routine
* merely resets the timer counter.
*
* The rate of the timestamp timer should be set explicitly within the BSP,
* in the sysHwInit() routine.  This routine does not intialize the timer
* rate.  
*
* RETURNS: OK, or ERROR if the timestamp timer cannot be enabled.
*/
 
STATUS sysTimestampEnable (void)
    {
    if (sysTimestampRunning)
	{
	*DGA_CSR14 &= (UINT32) ~CSR14_TT1CEN;	/* stop timer */
	*DGA_CSR15  = (UINT32) NULL; 		/* clear count */
	*DGA_CSR14 |= (UINT32) CSR14_TT1CEN;	/* start timer */
	return (OK);
	}
    
    *DGA_CSR14  = (UINT32) NULL;		/* stop timer */
    *DGA_CSR15  = (UINT32) NULL;		/* clear count */
    *DGA_CSR23  = (UINT32) CSR23_TT1ICL;	/* clear interrupt */

    if (intConnect (INT_VEC_TT1, sysTimestampInt, NULL) != OK)
	return (ERROR);

    *DGA_CSR25 = (UINT32)((*DGA_CSR25 & 0xff0fffff)
	       | (((TIMESTAMP_LEVEL >> 1) & 0x7) << 20));
						/* set interrupt level */
    *DGA_CSR21 |= (UINT32) CSR21_TT1IEN;	/* enable interrupt */

    /* load compare register with the number of micro seconds and
     * start the counter.
     */
    *DGA_CSR14 = (UINT32)(sysTimestampPeriod() | CSR14_TT1CEN);

    sysTimestampRunning = TRUE;
    return (OK);
    }

/********************************************************************************
* sysTimestampDisable - disable the timestamp timer
*
* This routine disables the timestamp timer.  Interrupts are not disabled,
* although the tick counter will not increment after the timestamp timer
* is disabled, thus interrupts will no longer be generated.
*
* RETURNS: OK, or ERROR if the timestamp timer cannot be disabled.
*/
 
STATUS sysTimestampDisable (void)
    {
    if (sysTimestampRunning)
	{
	*DGA_CSR21 &= (UINT32) ~CSR21_TT1IEN;	/* disable interrupt */
	*DGA_CSR14 &= (UINT32) ~CSR14_TT1CEN;	/* stop timer */
	*DGA_CSR23 = (UINT32) CSR23_TT1ICL;	/* clear pending interrupt */

	sysTimestampRunning = FALSE;
	}
    return (OK);
    }

/*******************************************************************************
*
* sysTimestampPeriod - get the timestamp timer period
*
* This routine returns the period of the timestamp timer in ticks.
* The period, or terminal count, is the number of ticks to which the timestamp
* timer will count before rolling over and restarting the counting process.
*
* RETURNS: The period of the timestamp timer in counter ticks.
*/
 
UINT32 sysTimestampPeriod (void)
    {
    return ((UINT32)0x00ffffff);	/* highest period -> freerunning */
    }

/*******************************************************************************
*
* sysTimestampFreq - get the timestamp timer clock frequency
*
* This routine returns the frequency of the timer clock, in ticks per second.
* The rate of the timestamp timer should be set explicitly within the BSP,
* in the sysHwInit() routine.
*
* RETURNS: The timestamp timer clock frequency, in ticks per second.
*/
 
UINT32 sysTimestampFreq (void)
    {
    return ((UINT32)DGA_TICK_FREQ);
    }

/*******************************************************************************
*
* sysTimestamp - get the 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 already locked, sysTimestampLock() should be used instead.
*
* NOTE DGA-001:
* The following code workarounds the DGA-001 up-counter glitch as shown below:
*
* .CS
*     1111                                .
*     1110                                :.
*     1101                                ::
*     1100                                ::.
*     1011                             -->: :<-- (few nano seconds)
*     1010                                : :
*     1001                                : :            _______________
*     1000                                : :____________
*     0111                 _______________:
*     0110  _______________
*
*          0              +1             +2             +3 [micro sec]
* .CE
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestampLock()
*/
 
UINT32 sysTimestamp (void)
    {
    UINT32 cnt1 = *DGA_CSR15 & 0x00ffffff;
    UINT32 cnt2 = *DGA_CSR15 & 0x00ffffff;

    if (cnt1 <= cnt2) return (cnt1);

    return (cnt2);
    }

/*******************************************************************************
*
* sysTimestampLock - get the 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 locks interrupts for cases where it is necessary to stop the
* tick counter in order to read it, or when two independent counters must
* be read.  If interrupts are already locked, sysTimestamp() should be
* used instead.
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestamp()
*/
 
UINT32 sysTimestampLock (void)
    {
    int lockKey = intLock ();

    UINT32 cnt1 = *DGA_CSR15 & 0x00ffffff;
    UINT32 cnt2 = *DGA_CSR15 & 0x00ffffff;

    intUnlock (lockKey);

    if (cnt1 <= cnt2) return (cnt1);

    return (cnt2);
    }

#endif	/* INCLUDE_TIMESTAMP */