*perr = OS_ERR_TMR_INACTIVE;
             return (OS_FALSE);

        default:
             OSTmr_Unlock();
             *perr = OS_ERR_TMR_INVALID_STATE;
             return (OS_FALSE);
    }
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                   STOP A TIMER
*
* Description: This function is called by your application code to stop a timer.
*
* Arguments  : ptmr          Is a pointer to the timer to stop.
*
*              opt           Allows you to specify an option to this functions which can be:
*
*                               OS_TMR_OPT_NONE          Do nothing special but stop the timer
*                               OS_TMR_OPT_CALLBACK      Execute the callback function, pass it the callback argument
*                                                        specified when the timer was created.
*                               OS_TMR_OPT_CALLBACK_ARG  Execute the callback function, pass it the callback argument
*                                                        specified in THIS function call
*
*              callback_arg  Is a pointer to a 'new' callback argument that can be passed to the callback function
*                               instead of the timer's callback argument.  In other words, use 'callback_arg' passed in
*                               THIS function INSTEAD of ptmr->OSTmrCallbackArg
*
*              perr          Is a pointer to an error code.  '*perr' will contain one of the following:
*                               OS_ERR_NONE
*                               OS_ERR_TMR_INVALID         'ptmr' is a NULL pointer
*                               OS_ERR_TMR_INVALID_TYPE    'ptmr'  is not pointing to an OS_TMR
*                               OS_ERR_TMR_ISR             if the function was called from an ISR
*                               OS_ERR_TMR_INACTIVE        if the timer was not created
*                               OS_ERR_TMR_INVALID_OPT     if you specified an invalid option for 'opt'
*                               OS_ERR_TMR_STOPPED         if the timer was already stopped
*                               OS_ERR_TMR_INVALID_STATE   the timer is in an invalid state
*                               OS_ERR_TMR_NO_CALLBACK     if the timer does not have a callback function defined
*
* Returns    : OS_TRUE       If the call was successful (if the timer is already stopped, we also return OS_TRUE)
*              OS_FALSE      If not
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
BOOLEAN  OSTmrStop (OS_TMR  *ptmr,
                    INT8U    opt,
                    void    *callback_arg,
                    INT8U   *perr)
{
    OS_TMR_CALLBACK  pfnct;


#if OS_ARG_CHK_EN > 0
    if (perr == (INT8U *)0) {                                     /* Validate arguments                               */
        return (OS_FALSE);
    }
    if (ptmr == (OS_TMR *)0) {
        *perr = OS_ERR_TMR_INVALID;
        return (OS_FALSE);
    }
#endif
    if (ptmr->OSTmrType != OS_TMR_TYPE) {                         /* Validate timer structure                         */
        *perr = OS_ERR_TMR_INVALID_TYPE;
        return (OS_FALSE);
    }
    if (OSIntNesting > 0) {                                       /* See if trying to call from an ISR                */
        *perr  = OS_ERR_TMR_ISR;
        return (OS_FALSE);
    }
    OSTmr_Lock();
    switch (ptmr->OSTmrState) {
        case OS_TMR_STATE_RUNNING:
             OSTmr_Unlink(ptmr);                                  /* Remove from current wheel spoke                  */
             *perr = OS_ERR_NONE;
             switch (opt) {
                 case OS_TMR_OPT_CALLBACK:
                      pfnct = ptmr->OSTmrCallback;                /* Execute callback function if available ...       */
                      if (pfnct != (OS_TMR_CALLBACK)0) {
                          (*pfnct)((void *)ptmr, ptmr->OSTmrCallbackArg);  /* Use callback arg when timer was created */
                      } else {
                          OSTmr_Unlock();
                          *perr = OS_ERR_TMR_NO_CALLBACK;
                          return (OS_FALSE);
                      }
                      break;

                 case OS_TMR_OPT_CALLBACK_ARG:
                      pfnct = ptmr->OSTmrCallback;                /* Execute callback function if available ...       */
                      if (pfnct != (OS_TMR_CALLBACK)0) {
                          (*pfnct)((void *)ptmr, callback_arg);   /* ... using the 'callback_arg' provided in call    */
                      } else {
                          OSTmr_Unlock();
                          *perr = OS_ERR_TMR_NO_CALLBACK;
                          return (OS_FALSE);
                      }
                      break;

                 case OS_TMR_OPT_NONE:
                      break;

                 default:
                     OSTmr_Unlock();
                     *perr = OS_ERR_TMR_INVALID_OPT;
                     return (OS_FALSE);
             }
             OSTmr_Unlock();
             return (OS_TRUE);

        case OS_TMR_STATE_COMPLETED:                              /* Timer has already completed the ONE-SHOT or ...  */
        case OS_TMR_STATE_STOPPED:                                /* ... timer has not started yet.                   */
             OSTmr_Unlock();
             *perr = OS_ERR_TMR_STOPPED;
             return (OS_TRUE);

        case OS_TMR_STATE_UNUSED:                                 /* Timer was not created                            */
             OSTmr_Unlock();
             *perr = OS_ERR_TMR_INACTIVE;
             return (OS_FALSE);

        default:
             OSTmr_Unlock();
             *perr = OS_ERR_TMR_INVALID_STATE;
             return (OS_FALSE);
    }
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                      SIGNAL THAT IT'S TIME TO UPDATE THE TIMERS
*
* Description: This function is typically called by the ISR that occurs at the timer tick rate and is used to signal to
*              OSTmr_Task() that it's time to update the timers.
*
* Arguments  : none
*
* Returns    : OS_ERR_NONE         The call was successful and the timer task was signaled.
*              OS_ERR_SEM_OVF      If OSTmrSignal() was called more often than OSTmr_Task() can handle the timers.  
*                                  This would indicate that your system is heavily loaded.
*              OS_ERR_EVENT_TYPE   Unlikely you would get this error because the semaphore used for signaling is created 
*                                  by uC/OS-II.
*              OS_ERR_PEVENT_NULL  Again, unlikely you would ever get this error because the semaphore used for signaling 
*                                  is created by uC/OS-II.
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
INT8U  OSTmrSignal (void)
{
    INT8U  err;


    err = OSSemPost(OSTmrSemSignal);
    return (err);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                               ALLOCATE AND FREE A TIMER
*
* Description: This function is called to allocate a timer.
*
* Arguments  : none
*
* Returns    : a pointer to a timer if one is available
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
static  OS_TMR  *OSTmr_Alloc (void)
{
    OS_TMR *ptmr;


    if (OSTmrFreeList == (OS_TMR *)0) {
        return ((OS_TMR *)0);
    }
    ptmr            = (OS_TMR *)OSTmrFreeList;
    OSTmrFreeList   = (OS_TMR *)ptmr->OSTmrNext;
    ptmr->OSTmrNext = (OS_TCB *)0;
    ptmr->OSTmrPrev = (OS_TCB *)0;
    OSTmrUsed++;
    OSTmrFree--;
    return (ptmr);
}
#endif


/*
************************************************************************************************************************
*                                             RETURN A TIMER TO THE FREE LIST
*
* Description: This function is called to return a timer object to the free list of timers.
*
* Arguments  : ptmr     is a pointer to the timer to free
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
static  void  OSTmr_Free (OS_TMR *ptmr)
{
    ptmr->OSTmrState       = OS_TMR_STATE_UNUSED;      /* Clear timer object fields                                   */
    ptmr->OSTmrOpt         = OS_TMR_OPT_NONE;
    ptmr->OSTmrPeriod      = 0;
    ptmr->OSTmrMatch       = 0;
    ptmr->OSTmrCallback    = (OS_TMR_CALLBACK)0;
    ptmr->OSTmrCallbackArg = (void *)0;
#if OS_TMR_CFG_NAME_SIZE > 1
    ptmr->OSTmrName[0]     = '?';                      /* Unknown name                                                */
    ptmr->OSTmrName[1]     = OS_ASCII_NUL;
#endif

    ptmr->OSTmrPrev        = (OS_TCB *)0;              /* Chain timer to free list                                    */
    ptmr->OSTmrNext        = OSTmrFreeList;
    OSTmrFreeList          = ptmr;

    OSTmrUsed--;                                       /* Update timer object statistics                              */
    OSTmrFree++;
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                    INITIALIZATION
*                                          INITIALIZE THE FREE LIST OF TIMERS
*
* Description: This function is called by OSInit() to initialize the free list of OS_TMRs.
*
* Arguments  : none
*
* Returns    : none
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
void  OSTmr_Init (void)
{
#if OS_EVENT_NAME_SIZE > 10
    INT8U    err;
#endif
    INT16U   i;
    OS_TMR  *ptmr1;
    OS_TMR  *ptmr2;


    OS_MemClr((INT8U *)&OSTmrTbl[0],      sizeof(OSTmrTbl));            /* Clear all the TMRs                         */
    OS_MemClr((INT8U *)&OSTmrWheelTbl[0], sizeof(OSTmrWheelTbl));       /* Clear the timer wheel                      */

    ptmr1 = &OSTmrTbl[0];
    ptmr2 = &OSTmrTbl[1];
    for (i = 0; i < (OS_TMR_CFG_MAX - 1); i++) {                        /* Init. list of free TMRs                    */
        ptmr1->OSTmrType    = OS_TMR_TYPE;
        ptmr1->OSTmrState   = OS_TMR_STATE_UNUSED;                      /* Indicate that timer is inactive            */
        ptmr1->OSTmrNext    = (void *)ptmr2;                            /* Link to next timer                         */
#if OS_TMR_CFG_NAME_SIZE > 1
        ptmr1->OSTmrName[0] = '?';                                      /* Unknown name                               */
        ptmr1->OSTmrName[1] = OS_ASCII_NUL;
#endif
        ptmr1++;
        ptmr2++;
    }
    ptmr1->OSTmrType    = OS_TMR_TYPE;
    ptmr1->OSTmrState   = OS_TMR_STATE_UNUSED;                          /* Indicate that timer is inactive            */
    ptmr1->OSTmrNext    = (void *)0;                                    /* Last OS_TMR                                */
#if OS_TMR_CFG_NAME_SIZE > 1
    ptmr1->OSTmrName[0] = '?';                                          /* Unknown name                               */
    ptmr1->OSTmrName[1] = OS_ASCII_NUL;
#endif
    OSTmrTime           = 0;
    OSTmrUsed           = 0;