at91timer.c

vwworks 在 at91rm9200上的bsp配置

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

LOCAL void sysAuxClkInt (void)
    {
    UINT32 dummy;

    /* acknowledge interrupt: a read of the Status Register clears interrupt */

    AT91_TIMER_READ (AUX_TIMER_STATUS, dummy);

    /* If any routine is attached via sysAuxClkConnect(), call it */

    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 also connects the clock error interrupt
* service routine.
*
* 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 with which to call routine        */
    )
    {
    sysAuxClkRoutine  = NULL;	/* ensure routine not called with wrong arg */
    sysAuxClkArg	  = arg;
    sysAuxClkRoutine  = routine;

    return OK;
    }

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

void sysAuxClkDisable (void)
    {
    if (sysAuxClkRunning)
        {
    	/* Disable timer in Channel Control Register */
    
    	AT91_TIMER_WRITE (AUX_TIMER_CCR, AT91_TIMER_CCR_CLKDIS);
    
    
    	/* Disable Register C Compare Interrupt in the timer */
    
    	AT91_TIMER_WRITE (AUX_TIMER_IDR, AT91_TIMER_IER_CPCS);
    
    
    	/* Disable the timer interrupt in the Interrupt Controller */
    
    	AT91_TIMER_INT_DISABLE (AUX_TIMER_INT_LVL);
    
    	sysAuxClkRunning = FALSE;
        }
    }

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

void sysAuxClkEnable (void)
    {
    UINT32 tm;

    if (!sysAuxClkRunning)
	{
	/*
	 * Calculate the timer match value:
	 * counter match value = (clock rate / sysAuxClkTicksPerSecond)
	 */

	tm = (AUX_TIMER_CLK / sysAuxClkTicksPerSecond);


	/* Load match value into Timer Register C */

	AT91_TIMER_WRITE (AUX_TIMER_REG_C, tm);

	/*
	 * Set up Channel Mode Register: waveform mode, divide MCKI by 128,
	 * Register C compare trigger (reset counter and start counter).
	 */

	AT91_TIMER_WRITE (AUX_TIMER_CMR, (AT91_TIMER_CMR_MCKI_128 | \
					  AT91_TIMER_CMR_CPCTRG | \
					  AT91_TIMER_CMR_WAVE));

    /* Clear Interrupt Status */

	AT91_TIMER_READ (AUX_TIMER_STATUS, tm);

	/* Enable Register C Compare Interrupt in the timer */

	AT91_TIMER_WRITE (AUX_TIMER_IER, AT91_TIMER_IER_CPCS);

	/* Enable the timer */

	AT91_TIMER_WRITE (AUX_TIMER_CCR, AT91_TIMER_CCR_CLKEN);

	/* Trigger the timer */

	AT91_TIMER_WRITE (AUX_TIMER_CCR, AT91_TIMER_CCR_SWTRG);


	/* enable clock interrupt in interrupt controller */

	AT91_TIMER_INT_ENABLE (AUX_TIMER_INT_LVL);

	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 axuxiliary clock interrupts unilaterally, but if the
* auxiliary clock is currently enabled, the clock is disabled and then
* re-enabled with the new rate.
*
*
* RETURNS: OK or ERROR.
*
* 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;

    sysAuxClkTicksPerSecond = ticksPerSecond;

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

    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.
*
* RETURNS: ERROR, always.
*/

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

/*******************************************************************************
*
* sysTimestampEnable - enable a timestamp timer interrupt
*
* This routine enables timestamp timer interrupts and resets the counter.
*
* RETURNS: OK, always.
*
* SEE ALSO: sysTimestampDisable()
*/

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

   if (!sysClkRunning)          /* timestamp timer is derived from the sysClk */
      return ERROR;

   sysTimestampRunning = TRUE;

   return OK;
   }

/*******************************************************************************
*
* sysTimestampDisable - disable a timestamp timer interrupt
*
* This routine disables timestamp timer interrupts.
*
* 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 system
     * clock.
     */

    return ((UINT32)(SYS_TIMER_CLK / sysClkTicksPerSecond));
    }

/*******************************************************************************
*
* 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 system clock serves as the timestamp timer,
* the system clock frequency is also the timestamp timer frequency.
*
* RETURNS: The timestamp timer clock frequency, in ticks per second.
*/

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

/*******************************************************************************
*
* 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)
    {
    UINT32 t;

    AT91_TIMER_READ (SYS_TIMER_CVR, t);

    return t;
    }

/*******************************************************************************
*
* 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 t;

    AT91_TIMER_READ (SYS_TIMER_CVR, t);

    return t;
    }

#endif  /* INCLUDE_TIMESTAMP */