//--------------------------------------------------------------------------
// IP Stack
//--------------------------------------------------------------------------
// llTimer.c
//
// Interface to low-level Timer support
// (DSP/BIOS PRD Based Timing)
//
// Note: This driver requires that a 500ms DSP/BIOS PRD timer
// be added to the aplicatons CDB file, and set to call the
// function llTimerTick() exported by this module.
//
// Author: Michael A. Denio
// Copyright 1999, 2003 by Texas Instruments Inc.
//-------------------------------------------------------------------------
#include <stkmain.h>
#include <clk.h>

//---------------------------------------------------------------------
// TIMER Functions
//---------------------------------------------------------------------

//
// This define is set to "1" to allow the timer to get down to 1mS
// accuracy by using the DSP/BIOS CLK low-resolution time.
// Set this define to "0" if the DSP/BIOS CLK is *not* based on 1mS
//
#define DSPBIOS_ENHANCED    1


//-----------------------
// Timer Device
//-----------------------
static UINT32      TimeStart;       // Time of initialization
static UINT32      TimeS;           // Time in seconds
static UINT32      TimeMS;          // Time fraction in MS
static UINT32      LastCLKTime;     // Last Time value returned from CLK function
static uint        LastCLKValid;     // Last Time value returned from CLK function
static int         TimerOpen = 0;   // Flag to know if we should be active

// This is the semaphore to signal when we have an event
static STKEVENT_Handle hEvent;

//--------------------------------------------------------------------
// llTimerTick()
//
// This task just counts HS Ticks as it is called from a DSP/BIOS
// PRD function running at 500ms.
//--------------------------------------------------------------------
void llTimerTick()
{
#ifdef USER_LED1
    LED_TOGGLE( USER_LED1 );
#endif

    if( TimerOpen )
    {
#if DSPBIOS_ENHANCED
        LastCLKTime  = CLK_getltime();
        LastCLKValid = 1;
#endif
        TimeMS += 100;
        if( TimeMS >= 1000 )
        {
            TimeS++;
            TimeMS -= 1000;
        }
        STKEVENT_signal( hEvent, STKEVENT_TIMER, 1 );
    }
}

//--------------------------------------------------------------------
// _llTimerInit()
//
// Initiate low-level timer support. Called with current time
// in seconds. Timer has a 130 year wrap, so starting time
// reference should be chosen with some care. The reference is
// irrelevant, but should be consisitent.
//--------------------------------------------------------------------
void _llTimerInit( STKEVENT_Handle h, UINT32 ctime )
{
    hEvent = h;
    TimeStart = TimeS = ctime;
    TimeMS = 0;
    TimerOpen = 1;
#if DSPBIOS_ENHANCED
    LastCLKValid = 0;
#endif
}

//--------------------------------------------------------------------
// _llTimerShutdown()
//
// Shutdown low-level timer support
//--------------------------------------------------------------------
void _llTimerShutdown()
{
    TimerOpen = 0;
}

//--------------------------------------------------------------------
// llTimerGetTime()
//
// Called to get the system time in S and optionally MS from bootup.
//--------------------------------------------------------------------
UINT32 llTimerGetTime( UINT32 *pMSFrac )
{
    register uint mask,sec;

    mask = OEMSysCritOn();

    sec = TimeS;
    if(pMSFrac)
    {
#if DSPBIOS_ENHANCED
        if( LastCLKValid )
            *pMSFrac = TimeMS + (CLK_getltime() - LastCLKTime);
        else
            *pMSFrac = TimeMS;
#else
        *pMSFrac = TimeMS;
#endif
    }

    OEMSysCritOff(mask);

    return(sec);
}

//--------------------------------------------------------------------
// llTimerGetStartTime()
//
// Called to get the time in S at which the timer was initialized.
//--------------------------------------------------------------------
UINT32 llTimerGetStartTime()
{
    return( TimeStart );
}