sysmpc107auxclk.c

Vxworks的bsp软件开发包(基于wrPpmc74xx)

/* epicAuxClk.c - PowerPC/MPC107 Epic auxiliary timer library */

/* Copyright 1984-2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01a,02may02,lmk  adapted from m8240AuxClk.c (ver 01a).
*/

/*
DESCRIPTION

This library provides PowerPC/MPC107 auxiliary clock.

The MPC107 Epic TIMER0 is used for the auxiliary clock.

The macros AUX_CLK_RATE_MIN, and AUX_CLK_RATE_MAX must be defined to
provide parameter checking for sysAuxClkRateSet() routine.

INCLUDE FILES: mpc107epic.h

SEE ALSO:
.pG "Configuration"
*/

/* includes */

#include "sysMpc107Epic.h"

/* local defines */

#ifndef EPIC_TIMER_CNT
#  define EPIC_TIMER_CNT       (MPC107_CLK_RATE / 8)
#endif

/* locals */

LOCAL FUNCPTR   sysAuxClkRoutine    = NULL;
LOCAL int   sysAuxClkArg            = 0;
LOCAL BOOL  sysAuxClkRunning        = FALSE;
LOCAL int   sysAuxClkTicksPerSecond = 60;


/***********************************************************************
*
* sysAuxClkInt - auxiliary clock interrupt handler
*
* This routine handles the auxiliary clock interrupt.  It calls a user routine
* if one was specified by the routine sysAuxClkConnect().
*
* RETURNS: N/A
*/

LOCAL void sysAuxClkInt
    (
    void
    )
    {
    if (sysAuxClkRoutine != NULL)
        (*sysAuxClkRoutine) (sysAuxClkArg);
    }

/***********************************************************************
*
* sysAuxClkInit - initialize the auxiliary clock
*
* This routine connects the auxiliary clock interrupt handler.  It places
* the timer into a disabled state and then connects the handler.
*
* RETURNS: N/A but the default aux clock handler is connected.
*/

void sysAuxClkInit
    (
    void
    )
    {
    /* disable counter */
    *EPIC_GTBC0 = LONGSWAP(0xffffffff);
    EIEIO;          /* synchronize */

    sysAuxClkRunning = FALSE;           /* clock is no longer running */

    /* Connect interrupt handler */
    (void) intConnect (INUM_TO_IVEC(INT_VEC_TMR0), (VOIDFUNCPTR) sysAuxClkInt, 0);
    }

/***********************************************************************
*
* 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 the TIMER0 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
    )
    {

    if (sysAuxClkRunning)
        {
        /* disable counter */

        *EPIC_GTBC0 = LONGSWAP(0xffffffff);
        EIEIO;          /* synchronize */

        sysAuxClkRunning = FALSE;           /* clock is no longer running */
        }
    }

/***********************************************************************
*
* 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)
        {
        /* disable counter */
        *EPIC_GTBC0 = LONGSWAP(0xffffffff);
        EIEIO;          /* synchronize */

        sysAuxClkRunning = FALSE;           /* clock is no longer running */
        }

    /* Interrupt unmasked, priority level set */
    *EPIC_GTVR0 = LONGSWAP(INT_VEC_TMR0 | INT_PRI_TMR0);
    EIEIO;          /* synchronize */

    /* Interrupt directed at processor 0 */
    *EPIC_GTD0  = LONGSWAP(0x00000001);
    EIEIO;          /* synchronize */

    /* enable counter and write value to count from */
    *EPIC_GTBC0 = LONGSWAP(((EPIC_TIMER_CNT/sysAuxClkTicksPerSecond) & 0x7fffffff));
    EIEIO;          /* 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 does not enable auxiliary clock interrupts.
*
* RETURNS: OK, or ERROR if the tick rate is invalid.
*
* 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);
    }