templatetimer.c

IXP425的BSP代码

/* templateTimer.c - template timer library */

/* Copyright 1984-2001 Wind River Systems, Inc. */

/*
TODO -	Remove the template modification history and begin a new history
	starting with version 01a and growing the history upward with
	each revision.

modification history
--------------------
01e,16oct01,dat  fixing warnings
01d,29oct97,dat  added protection for calling sysHwInit2 more than once.
01c,23sep97,dat  changed arg to TEMPLATE_REG_READ
01b,12mar97,dat  added basic timestamp support, some doc cleanup
01a,23dec96,ms   written by gutting i8253Timer.c.
*/

/*
TODO - This is an example timer.  It must be replaced with specific
information and code for the actual device used as the timer.

DESCRIPTION
Describe the chip being used completely, even if it provides more features
than just timers.

Describe the device's capabilities as a timer, even if this driver doesn't
or can't utilize all of them.  Describe the timer features that the driver
does implement and any restrictions on their use.

Describe all macros that can be used to customize this driver.  All
accesses to chip registers should be done through a redefineable macro.
In this example driver the macros TEMPLATE_READ and TEMPLATE_WRITE
are sample macros to read/write data to a mock device.  If a device
communicates through formatted control blocks in shared memory, the
accesses to those control blocks should also be through a redefinable
macro.

This driver provides 3 main functions, system clock support, auxilliary
clock support, and timestamp timer support.  If necessary, each function
may be conditioned by a separate INCLUDE_ macro.  The timestamp function
is always conditional upon the INCLUDE_TIMESTAMP macro.

The macros SYS_CLK_RATE_MIN, SYS_CLK_RATE_MAX, AUX_CLK_RATE_MIN, and
AUX_CLK_RATE_MAX must be defined to provide parameter checking for the
sys[Aux]ClkRateSet() routines.

INCLUDES:
timestampDev.h
*/

/* includes */

#include "vxWorks.h"
#include "config.h"
#include "drv/timer/timerDev.h"
#include "drv/timer/timestampDev.h"

/* defines */

#define TIMESTAMP_HZ	1000000			 /* timestamp counter freq */

/* The default is to assume memory mapped I/O */

#ifndef TEMPLATE_READ
#define TEMPLATE_READ(reg, result) \
	(result = *reg)
#endif /*TEMPLATE_READ*/

#ifndef TEMPLATE_WRITE
#define TEMPLATE_WRITE(reg, data) \
	(*reg = data)
#endif /*TEMPLATE_WRITE*/


/* locals */

LOCAL FUNCPTR sysClkRoutine	= NULL; /* routine to call on clock tick */
LOCAL int sysClkArg		= 0; /* its argument */
LOCAL BOOL sysClkRunning	= FALSE;
LOCAL int sysClkTicksPerSecond	= 60;

LOCAL FUNCPTR sysAuxClkRoutine	= NULL;
LOCAL int sysAuxClkArg		= 0;
LOCAL BOOL sysAuxClkRunning	= FALSE;
LOCAL int sysAuxClkTicksPerSecond = 100;

#ifdef INCLUDE_TIMESTAMP

LOCAL BOOL	sysTimestampRunning	= FALSE; /* running flag */
LOCAL int	sysTimestampPeriodValue	= 0;	 /* Max counter value */
LOCAL FUNCPTR	sysTimestampRoutine	= NULL;  /* routine to call on intr */
LOCAL int	sysTimestampArg		= 0;     /* arg for routine */

      void	sysTimestampInt (void);		 /* forward declaration */

#endif  /* INCLUDE_TIMESTAMP */


/*******************************************************************************
*
* sysClkInt - interrupt level processing for system clock
*
* This routine handles an auxiliary clock interrupt.  It acknowledges the
* interrupt and calls the routine installed by sysClkConnect().
*/

void sysClkInt (void)
    {
    /* TODO - acknowledge the interrupt if needed */

    /* call system clock service routine */

    if (sysClkRoutine != NULL)
	(* sysClkRoutine) (sysClkArg);
    }


/*******************************************************************************
*
* sysClkConnect - connect a routine to the system clock interrupt
*
* This routine specifies the interrupt service routine to be called at each
* clock interrupt.  Normally, it is called from usrRoot() in usrConfig.c to 
* connect usrClock() to the system clock interrupt.
*
* RETURN: OK, or ERROR if the routine cannot be connected to the interrupt.
*
* SEE ALSO: intConnect(), usrClock(), sysClkEnable()
*/

STATUS sysClkConnect
    (
    FUNCPTR routine,	/* routine to be called at each clock interrupt */
    int arg		/* argument with which to call routine */
    )
    {
    static BOOL beenHere = FALSE;

    if (!beenHere)
	{
	beenHere = TRUE;
	sysHwInit2 ();	/* XXX for now -- needs to be in usrConfig.c */
	}

    sysClkRoutine   = NULL;
    sysClkArg	    = arg;
    sysClkRoutine   = routine;

    return (OK);
    }


/*******************************************************************************
*
* sysClkDisable - turn off system clock interrupts
*
* This routine disables system clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysClkEnable()
*/

void sysClkDisable (void)
    {
    if (sysClkRunning)
	{
	/* TODO - disable system timer interrupts */
	
	sysClkRunning = FALSE;
	}
    }


/*******************************************************************************
*
* sysClkEnable - turn on system clock interrupts
*
* This routine enables system clock interrupts.
*
* RETURNS: N/A
*
* SEE ALSO: sysClkConnect(), sysClkDisable(), sysClkRateSet()
*/

void sysClkEnable (void)
    {
    static BOOL connected = FALSE;

    if (!connected)
	{
	/* TODO - connect sysClkInt to appropriate interrupt */

	connected = TRUE;
	}

    if (!sysClkRunning)
	{
	/*
	 * TODO - start system timer interrupts at a
	 * at a frequency of sysClkTicksPerSecond
	 */
	
	sysClkRunning = TRUE;
	}
    }


/*******************************************************************************
*
* sysClkRateGet - get the system clock rate
*
* This routine returns the system clock rate.
*
* RETURNS: The number of ticks per second of the system clock.
*
* SEE ALSO: sysClkEnable(), sysClkRateSet()
*/

int sysClkRateGet (void)
    {
    return (sysClkTicksPerSecond);
    }


/*******************************************************************************
*
* sysClkRateSet - set the system clock rate
*
* This routine sets the interrupt rate of the system clock.
* It is called by usrRoot() in usrConfig.c.
*
* RETURNS: OK, or ERROR if the tick rate is invalid or the timer cannot be set.
*
* SEE ALSO: sysClkEnable(), sysClkRateGet()
*/

STATUS sysClkRateSet
    (
    int ticksPerSecond	    /* number of clock interrupts per second */
    )
    {
    if (ticksPerSecond < SYS_CLK_RATE_MIN || ticksPerSecond > SYS_CLK_RATE_MAX)
	return (ERROR);

    /* TODO - return ERROR if rate is not supported */

    sysClkTicksPerSecond = ticksPerSecond;

    if (sysClkRunning)
	{
	sysClkDisable ();
	sysClkEnable ();
	}

    return (OK);
    }

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

void sysAuxClkInt (void)
    {
    /* TODO - acknowledge the interrupt if needed */

    /* call auxiliary clock service routine */

    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 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 */
    )
    {
    sysAuxClkRoutine	= NULL;
    sysAuxClkArg	= arg;
    sysAuxClkRoutine	= routine;

    return (OK);
    }

/*******************************************************************************