ppcdectimer.c

ge公司的dv4av4信号处理板的bsp源代码

/***************************************************************************
*
*  $RCSfile: ppcDecTimer.c $
*
*  Copyright 2001 by Dy 4 Systems, Inc.  All Rights Reserved.
*
*  $Revision: 1.7 $
*
*  $Name: AV4-ISP-R1.2-1 AV4-ISP-R1.2-0 HMTST2 HMTST1 DVT_AV4_4.101 AV4-VSP-R1.0-2 AV4-VSP-R1.0 CT-ISP-1.1 AV4 ISP 1.1 CT_R0.1_AV4/CAV4 champtools2.22 CAV4_CP1 CHAMPtools FW 3.0 champtools2.21_1215 champtools2.21 champ221_build1 champtools2.2 CHAMPtools_2.1.1_AV3 CHAMPtools_2.1_106 CHAMPtools_2.0_AV3 $  $State: Developmental $  $Locker: $
*
*  $Source: L:/SWRND/champAV2/src/vx/src/drv/timer/rcs/ppcDecTimer.c $
*
*  RCS Project Name:
*
*  CSC:
*
*  Target:
*
*  Description:
*
*  Usage:
*
*  $Log: ppcDecTimer.c $
*  Revision 1.7  2004/01/21 21:03:44Z  dsessler
*  Removed timestampDev.h and obsolete comments re. timestamp
*  and auxtimer drivers.
*  Revision 1.6  2002/05/08 16:00:09  coopertr
*  Revision 1.5  2002/03/27 20:02:31  dsessler
*
****************************************************************************/

/* Copyright 1984-1997 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01o,03mar98,jgn  Re-enable interrupts during system clock tick processing
		 (SPR #10000)
01n,04nov96,tam  renamed MEMORY_BUS_SPEED to DEC_CLOCK_FREQ, BUS_CLK_TO_INC
		 to DEC_CLK_TO_INC and DEFAULT_BUS_SPEED to DEFAULT_DEC_CLK_FREQ
		 (spr #7423).
01m,29oct96,wlf  doc: cleanup.
01l,31jul96,dat  added PPC_TMR_RATE_SET_ADJUST
01k,22jul96,tam  cleanup. added timestamp support. Changed CPU_SPEED macro to 
		 MEMORY_BUS_SPEED.
01j,17jun96,tpr  optimized sysClkInt() assembly code.
01i,14may96,tam  fixed drift in sysClkInt. Changed DEFAULT_CPU_SPEED to 
		 33333333 (33.33 Mhz)
01h,11mar96,ms   fixed roundoff in sysClkInt.
01g,12feb96,tpr  reworked.
01f,23oct95,kvk  cleanup.
01e,22may95,caf  added conditional compile for PowerPC 601.
01d,02may95,caf  cleanup.
01c,27apr95,caf  removed vxDecEnable() and PPC60x_TIMER_INT_VECTOR,
		 changed name to ppcDecTimer.c.
01b,25jan95,vin	 cleanup.
01a,20jan95,kvk  written.
*/

/*
DESCRIPTION
This library provides PowerPC decrementer timer routines.

The macro DEC_CLOCK_FREQ (frequency of the decrementer input clock) should be
defined before using this module. The macro DEC_CLK_TO_INC (ratio between the
number of decrementer input clock cycles and one counter increment) can be 
redefined prior to #including this file into sysLib.c.
The macros SYS_CLK_RATE_MIN and SYS_CLK_RATE_MAX must be defined to provide
parameter checking for sysClkRateSet().

If dynamic bus clock speed calculation is needed, the BSP can define the
macro PPC_TMR_RATE_SET_ADJUST to be a call to the needed routine.
This macro, if defined, will be executed during each call to sysClkRateSet().
PPC_TMR_RATE_SET_ADJUST is usually not defined.

    e.g. Assuming sysClkRateAdjust can compute a correct value
    for sysDecClkFrequency.

    #define PPC_TMR_RATE_SET_ADJUST \
	sysClkRateAdjust (&sysDecClkFrequency)



INCLUDE FILES: ppcDecTimer.h
   
SEE ALSO:
.pG "Configuration"
*/

/* includes */

#include "arch/ppc/vxPpcLib.h"
#include "drv/timer/ppcDecTimer.h"

/* local defines */

#define DEFAULT_HZ          60
#define DEFAULT_FREQ        (133333333/4)
#define DEFAULT_COUNT       (DEFAULT_FREQ/DEFAULT_HZ)


#ifndef CPU_INT_UNLOCK
#    define  CPU_INT_UNLOCK(x) (intUnlock(x))
#endif

#ifndef CPU_INT_LOCK
#    define  CPU_INT_LOCK(x) (*x = intLock())
#endif

/* extern declarations */

IMPORT STATUS	excIntConnect (VOIDFUNCPTR *, VOIDFUNCPTR);

/* Locals */
LOCAL int      sysClkTicksPerSecond   = DEFAULT_HZ;	/* ticks per sec */
LOCAL FUNCPTR	sysClkRoutine          = NULL;
LOCAL int      sysClkArg              = 0;
LOCAL BOOL     sysClkConnectFirstTime = TRUE;
LOCAL int      decCountVal            = DEFAULT_COUNT;	
LOCAL BOOL     sysClkRunning          = FALSE;
LOCAL int      sysDecClkFrequency     = DEFAULT_FREQ;

/* Dino M. Change 11/17/2005 Macro Definition per Wind River */

#ifdef __DCC__

asm void ClkIntMacro (decountVal)
{
% lab sysClkIntLoop; reg decountVal;
!"r3", "r0"

		mfdec	0
sysClkIntLoop:
		add.	0, 3, 0
		ble	sysClkIntLoop
		mtdec	0
}

#endif

/* End Of Dino M. Change */

/*******************************************************************************
*
* sysClkInt - clock interrupt handler
*
* This routine handles the clock interrupt on the PowerPC architecture. It is
* attached to the decrementer vector by the routine sysClkConnect().
*
* RETURNS : N/A
*/

LOCAL void sysClkInt (void)
    {
    	/* int decr;*/
    /*
     * The PowerPC decrementer doesn't reload the value by itself. The reload
     * need to be performed in this handler. The reload value should be 
     * adjusted each time because the time spent between the exception
     * generation and the moment the register is reloaded changes.
     * By reading the decrementer we obtain the time spent between the 
     * two events and can adjust the value to reload. This is done in assembly
     * language in order to minimize time spent between reading and writing
     * to the decrementer register in order to maximize system clock accuracy.
     */
#ifdef __DCC__
 
	    ClkIntMacro (decCountVal);
	           
#else
  int decr;

    __asm__ ("mfdec %0" : "=r" (decr)); 
     while ( 0 > decr )
     { 
     	decr += decCountVal;
     } 
     __asm__ ( "mtdec %0" : : "r" (decr) );
 
/*

__asm__ ("
    mfdec 3	
sysClkIntLoop:
    add. 	3, %0, 3
    ble		sysClkIntLoop	
    mtdec	3"
    :	
    : "r" (decCountVal)		
    : "3", "cc"                         
    );

*/
#endif
    
    /* Unlock interrupts during decrementer processing */

    CPU_INT_UNLOCK (_PPC_MSR_EE);

    /* execute the system clock routine */

    if (sysClkRunning && (sysClkRoutine != NULL))
	(*(FUNCPTR) 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.
*
* RETURNS: OK, or ERROR if the routine cannot be connected to the interrupt.
*
* SEE ALSO: intConnect(), usrClock(), sysClkEnable()
*/
    
STATUS sysClkConnect
    (
    FUNCPTR 	routine,	/* routine to connect */
    int 	arg		/* argument for the routine */
    )
    {

    if (sysClkConnectFirstTime)
	{
	sysHwInit2();
	sysClkConnectFirstTime = FALSE;
	}

    sysDecClkFrequency = bslBoardGetBusSpeed()/4;

    /* connect the routine to the decrementer exception */

    excIntConnect ((VOIDFUNCPTR *) _EXC_OFF_DECR, (VOIDFUNCPTR) sysClkInt);
    
    sysClkRoutine	= routine;
    sysClkArg		= arg;

    return (OK);
    }

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

void sysClkEnable (void)
    {
    if (!sysClkRunning)
	{
	sysClkRunning = TRUE;
	vxDecSet (decCountVal);
	}
    }

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

void sysClkDisable (void)
    {
    if (sysClkRunning)
	sysClkRunning = FALSE;
    }

/******************************************************************************
*
* 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);

    /* save the clock speed */

    sysClkTicksPerSecond = ticksPerSecond;

    /* Calibrate the clock, if needed. */

#ifdef PPC_TMR_RATE_SET_ADJUST
    PPC_TMR_RATE_SET_ADJUST;
#endif

    /* 
     * compute the value to load in the decrementer. The new value will be
     * load in the decrementer after the end of the current period
     */

    decCountVal = sysDecClkFrequency / ticksPerSecond;

    return (OK);
    }