mpc8240auxclk.c

MPC8241:本程序是freescale的824*系列的BSP源程序

/* mpc8240AuxClk.c - Mpc8240 EPIC Timer (Aux Clk) library */

/* Copyright 1999-2000 Wind River Systems, Inc. */
/* Copyright 1999-2000 Motorola, Inc. All Rights Reserved */
 
/*
modification history
--------------------
01a,28feb00,rhk  created from version 01e, MV2100 BSP.
*/
 
/*
DESCRIPTION
This timer contains routines to use timer 0 on the EPIC as the auxiliary
clock.
*/


/* includes */

#include "prpmc600.h"

/* defines */

#define EPIC_TIMER_CNT	(DEC_CLOCK_FREQ / 8)

/* locals */

LOCAL void    sysAuxClkInt ();
LOCAL STATUS  sysAuxClkInit();
LOCAL FUNCPTR sysAuxClkRoutine        = NULL;
LOCAL int     sysAuxClkArg            = NULL;
LOCAL int     sysAuxClkTicksPerSecond = 100;
LOCAL BOOL    sysAuxClkConnected      = FALSE;
LOCAL int     sysAuxClkRunning        = FALSE;

/* externals */

IMPORT void   sysPciOutLong (UINT32, UINT32);

/******************************************************************************
*
* sysAuxClkInt - handle an auxiliary clock interrupt from EPIC timer 0
*
* This routine handles a EPIC timer 0 interrupt.  It clears the interrupt
* and calls the routine installed by sysAuxClkConnect().
*
* RETURNS: N/A
*/
 
LOCAL void sysAuxClkInt (void)
    {
    if (sysAuxClkRoutine != NULL)
 	(*sysAuxClkRoutine) (sysAuxClkArg);
    }
 

/*****************************************************************************
*
* sysAuxClkInit - mpc8240 aux. clock initialization routine
*
* This routine should be called before calling any other routine in this
* module.
*
* RETURNS: OK, or ERROR.
*/
 
STATUS sysAuxClkInit (void)
    {
    /* disable counter */

    sysPciOutLong ((UINT32)EPIC_TIMER0_BASE_CT_REG, (0xffffffff) );
    SYNC;					/* synchronize */
   
    /* setup timer frequency register */

    sysPciOutLong ((UINT32)EPIC_TIMER_FREQ_REG, (UINT32)EPIC_TIMER_CNT);
   
    /* interrupt unmasked, priority level 15, vector TIMER0_INT_VEC. */

    sysPciOutLong ((UINT32)EPIC_TIMER0_VEC_PRI_REG, 
                  (( EPIC_GTVP_PRI_15 | (TIMER0_INT_VEC) ) & ~EPIC_GTVP_M));
   
    /* interrupt directed at processor 0 */

    sysPciOutLong ((UINT32)EPIC_TIMER0_DEST_REG, EPIC_GTD_P0);

    SYNC;					/* synchronize */
   
    sysAuxClkRunning = FALSE;
   
    return (OK);
    }


/******************************************************************************
*
* sysAuxClkConnect - connect a routine to the auxiliary clock interrupt
*
* This routine specifies the interrupt service routine to be called at each
* auxiliary clock interrupt.
*
* 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	= routine;
    sysAuxClkArg	= arg;
    sysAuxClkConnected	= TRUE;
 
    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 counter */

	sysPciOutLong ((UINT32)EPIC_TIMER0_BASE_CT_REG, 0xffffffff);
	SYNC;					/* synchronize */
        
        sysAuxClkRunning = FALSE;
        }
    }


/******************************************************************************
*
* sysAuxClkEnable - turn on auxiliary clock interrupts
*
* This routine enables auxiliary clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysAuxClkDisable()
*/
 
void sysAuxClkEnable (void)
    {
    if (!sysAuxClkRunning)
	{
	/* enable counter and write value to count from */

	sysPciOutLong ((UINT32)EPIC_TIMER0_BASE_CT_REG,
	               ((EPIC_TIMER_CNT/sysAuxClkTicksPerSecond) & 
		       EPIC_GTBC_C_MASK));
	SYNC;					/* synchronize */
	  
	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 is not
* supported, since the auxiliary clock always runs at the same rate as the
* system clock.
*
* 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);
    }