sa1100timer.c

IXP425的BSP代码

    int key;

    /* clear interrupt */

    SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 1);


    /*
     * Load the match register with a new value calculated by
     * adding the ticks per interrupt to the current value of the
     * counter register.  Note that this may wraparound to a value
     * less than the current counter value but that's OK.
     */

    key = intLock ();

    SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OSCR, tc);
    tc += sysAuxClkTicks;
    SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSMR_1, tc);

    intUnlock (key);


    /* If any routine 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)
    {
    UINT32 oier;
    int key;

    if (sysAuxClkRunning)
        {
	/* disable timer interrupt in the timer */

	key = intLock ();

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OIER, oier);
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OIER, oier & ~(1 << 1));

	intUnlock (key);


	/* clear any pending interrupt */

	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 1);


	/* disable timer interrupt in the interrupt controller */

	SA1100_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 tc, oier;
    int key;

    if (!sysAuxClkRunning)
	{
	/*
	 * Calculate the number of ticks of the timer clock that this
	 * period requires.  Do this once, here, so that the timer interrupt
	 * routine does not need to perform a division.
	 */
	sysAuxClkTicks = (AUX_TIMER_CLK / sysAuxClkTicksPerSecond) -
					    SA1100_TIMER_RELOAD_CORRECTION;


	/* clear any pending interrupt */

	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 1);


	/*
	 * Load the match register with a new value calculated by
	 * adding the ticks per interrupt to the current value of the
	 * counter register.  Note that this may wraparound to a value
	 * less than the current counter value but that's OK.
	 */

	key = intLock ();

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OSCR, tc);
	tc += sysAuxClkTicks;
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSMR_1, tc);


	/* enable interrupt in timer */

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OIER, oier);
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OIER, oier | (1 << 1));

	intUnlock (key);


	/* enable clock interrupt in interrupt controller */

	SA1100_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 auxiliary 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;
    }

#endif /* INCLUDE_AUX_CLK */

#ifdef  INCLUDE_TIMESTAMP

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

void sysTimestampInt (void)
    {
    /* clear interrupt */

    SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 2);


    /*
     * do not reload the match register - another interrupt will be
     * generated next time the counter hits the current value
     *
     * If any routine attached via sysTimestampConnect(), call it
     */

    if (sysTimestampRunning && sysTimestampRoutine != NULL)
	(*sysTimestampRoutine)(sysTimestampArg);
    }

/*******************************************************************************
*
* 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 = NULL;
    sysTimestampArg = arg;
    sysTimestampRoutine = routine;

    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 hardware cannot be enabled.
*/

STATUS sysTimestampEnable (void)
    {
    static BOOL connected = FALSE;
    UINT32 tc, oier;
    int key;

    if (!connected)
	{
	/* connect sysTimestampInt to the appropriate interrupt */

	intConnect (INUM_TO_IVEC (INT_LVL_TIMER_2), sysTimestampInt, 0);
	connected = TRUE;
	}

    if (!sysTimestampRunning)
	{
	/*
	 * Set match register (OSMR) to (current counter value) (OSCR)
	 * minus one so that an interrupt will be generated when the
	 * counter wraps around to that value but there will not be an
	 * immediate interrupt. This means that the first interrupt will
	 * arrive one tick too soon but this inaccuracy should be
	 * tolerable.
	 */

	key = intLock();

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OSCR, tc);
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSMR_2, tc - 1);


	/* clear any pending interrupt */

	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 2);


	/* enable interrupt in timer */

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OIER, oier);
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OIER, oier | (1 << 2));

	intUnlock (key);


	/* enable clock interrupt in interrupt controller */

	SA1100_TIMER_INT_ENABLE (TIMESTAMP_TIMER_INT_LVL);

	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 timer cannot be disabled.
*/

STATUS sysTimestampDisable (void)
    {
    UINT32 oier;
    int key;

    if (sysTimestampRunning)
	{
	/* disable timer interrupt in the timer */

	key = intLock ();

	SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OIER, oier);
	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OIER, oier & ~(1 << 2));

	intUnlock (key);


	/* clear any pending interrupt */

	SA1100_TIMER_REG_WRITE (SA1100_TIMER_CSR_OSSR, 1 << 2);


	/* disable timer interrupt in the interrupt controller */

	SA1100_TIMER_INT_DISABLE (TIMESTAMP_TIMER_INT_LVL);

        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 0xFFFFFFFF;		/* max value of 32-bit counter */
    }

/*******************************************************************************
*
* sysTimestampFreq - get the timestamp timer clock frequency
*
* This routine returns the frequency of the timer clock, in ticks per second.
*
* RETURNS: The timestamp timer clock frequency, in ticks per second.
*/

UINT32 sysTimestampFreq (void)
    {
    return TIMESTAMP_TIMER_CLK;
    }

/*******************************************************************************
*
* 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.
*
* RETURNS: The current timestamp timer tick count.
*
* SEE ALSO: sysTimestampLock()
*/

UINT32 sysTimestamp (void)
    {
    UINT32 count, match;

    /*
     * read count and match registers - this is effectively atomic
     * (since the match register is not reloaded on interrupt) so there is
     * no need to disable interrupts around this.
     */

    SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OSCR, count);
    SA1100_TIMER_REG_READ (SA1100_TIMER_CSR_OSMR_2, match);


    /*
     * When the timer was enabled, the match register (OSMR) was
     * initialised to the current value of the count register (OSCR) and
     * then generates an interrupt every time the two registers match.
     * The ticks since the last interrupt are thus (OSCR - OSMR).
     */

    return count - match;
    }

/*******************************************************************************
*
* 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)
    {
    /* no need to disable interrupts - see sysTimestamp() */

    return sysTimestamp ();
    }

#endif  /* INCLUDE_TIMESTAMP */