os_tmr.c

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    if (ptmr->OSTmrType != OS_TMR_TYPE) {              /* Validate timer structure                                    */
        *perr = OS_ERR_TMR_INVALID_TYPE;
        return (0);
    }
    if (OSIntNesting > 0) {                            /* See if trying to call from an ISR                           */
        *perr = OS_ERR_TMR_ISR;
        return (0);
    }
    OSTmr_Lock();
    switch (ptmr->OSTmrState) {
        case OS_TMR_STATE_RUNNING:
             remain = ptmr->OSTmrMatch - OSTmrTime;    /* Determine how much time is left to timeout                  */
             OSTmr_Unlock();
             *perr  = OS_NO_ERR;
             return (remain);

        case OS_TMR_STATE_STOPPED:                     /* It's assumed that the timer has not started yet             */
             switch (ptmr->OSTmrOpt) {
                 case OS_TMR_OPT_PERIODIC:
                      if (ptmr->OSTmrDly == 0) {
                          remain = ptmr->OSTmrPeriod;
                      } else {
                          remain = ptmr->OSTmrDly;
                      }
                      OSTmr_Unlock();
                      *perr  = OS_NO_ERR;
                      break;

                 case OS_TMR_OPT_ONE_SHOT:
                      remain = ptmr->OSTmrDly;
                      OSTmr_Unlock();
                      *perr  = OS_NO_ERR;
                      break;
             }
             return (remain);

        case OS_TMR_STATE_COMPLETED:                   /* Only ONE-SHOT that timed out can be in this state           */
             OSTmr_Unlock();
             *perr  = OS_NO_ERR;
             return (0);

        case OS_TMR_STATE_UNUSED:
             OSTmr_Unlock();
             *perr  = OS_ERR_TMR_INACTIVE;
             return (0);

        default:
             OSTmr_Unlock();
             *perr  = OS_ERR_TMR_INVALID_STATE;
             return (0);
    }
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                    FIND OUT WHAT STATE A TIMER IS IN
*
* Description: This function is called to determine what state the timer is in:
*
*                  OS_TMR_STATE_UNUSED     the timer has not been created
*                  OS_TMR_STATE_STOPPED    the timer has been created but has not been started or has been stopped
*                  OS_TMR_COMPLETED        the timer is in ONE-SHOT mode and has completed it's timeout
*                  OS_TMR_RUNNING          the timer is currently running
*
* Arguments  : ptmr          Is a pointer to the desired timer
*
*              perr          Is a pointer to an error code.  '*perr' will contain one of the following:
*                               OS_NO_ERR
*                               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 call was made from an ISR
*                               OS_ERR_TMR_INACTIVE       'ptmr' points to a timer that is not active
*                               OS_ERR_TMR_INVALID_STATE  if the timer is not in a valid state
*
* Returns    : The current state of the timer (see description).
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
INT8U  OSTmrStateGet (OS_TMR  *ptmr,
                      INT8U   *perr)
{
    INT8U  state;


#if OS_ARG_CHK_EN > 0
    if (perr == (INT8U *)0) {
        return (0);
    }
    if (ptmr == (OS_TMR *)0) {
        *perr = OS_ERR_TMR_INVALID;
        return (0);
    }
#endif
    if (ptmr->OSTmrType != OS_TMR_TYPE) {              /* Validate timer structure                                    */
        *perr = OS_ERR_TMR_INVALID_TYPE;
        return (0);
    }
    if (OSIntNesting > 0) {                            /* See if trying to call from an ISR                           */
        *perr = OS_ERR_TMR_ISR;
        return (0);
    }
    OSTmr_Lock();
    state = ptmr->OSTmrState;
    switch (state) {
        case OS_TMR_STATE_UNUSED:   
        case OS_TMR_STATE_STOPPED:  
        case OS_TMR_STATE_COMPLETED:
        case OS_TMR_STATE_RUNNING:  
             *perr = OS_NO_ERR;
             break;
             
        default:
             *perr = OS_ERR_TMR_INVALID_STATE;
             break;
    }
    OSTmr_Unlock();
    return (state);
}
#endif

/*$PAGE*/
/*
************************************************************************************************************************
*                                                   START A TIMER
*
* Description: This function is called by your application code to create and start a timer.
*
* Arguments  : ptmr          Is a pointer to an OS_TMR
*
*              perr          Is a pointer to an error code.  '*perr' will contain one of the following:
*                               OS_NO_ERR
*                               OS_ERR_TMR_INVALID
*                               OS_ERR_TMR_INVALID_TYPE    'ptmr'  is not pointing to an OS_TMR
*                               OS_ERR_TMR_ISR             if the call was made from an ISR
*                               OS_ERR_TMR_INACTIVE        if the timer was not created
*                               OS_ERR_TMR_INVALID_STATE   the timer is in an invalid state
*
* Returns    : OS_TRUE    if the timer was started
*              OS_FALSE   if an error was detected
************************************************************************************************************************
*/

#if OS_TMR_EN > 0
BOOLEAN  OSTmrStart (OS_TMR   *ptmr,
                     INT8U    *perr)
{
#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:                          /* Restart the timer                                      */
             OSTmr_Unlink(ptmr);                            /* ... Stop the timer                                     */
             OSTmr_Link(ptmr, OS_TMR_LINK_DLY);             /* ... Link timer to timer wheel                          */
             OSTmr_Unlock();
             *perr = OS_NO_ERR;
             return (OS_TRUE);

        case OS_TMR_STATE_STOPPED:                          /* Start the timer                                        */
        case OS_TMR_STATE_COMPLETED:
             OSTmr_Link(ptmr, OS_TMR_LINK_DLY);             /* ... Link timer to timer wheel                          */
             OSTmr_Unlock();
             *perr = OS_NO_ERR;
             return (OS_TRUE);

        case OS_TMR_STATE_UNUSED:                           /* Timer 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*/
/*
************************************************************************************************************************
*                                                   STOP A TIMER
*
* Description: This function is called by your application code to stop and delete a timer.
*
* Arguments  : ptmr          Is a pointer to the timer to stop and delete.
*
*              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_NO_ERR
*                               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_NO_ERR;
             switch (opt) {
                 case OS_TMR_OPT_CALLBACK:
                      pfnct = ptmr->OSTmrCallback;                /* Execute callback function if available ...       */
                      if (pfnct != (OS_TMR_CALLBACK)0) {
                          (*pfnct)(ptmr, ptmr->OSTmrCallbackArg); /* ... using the 'argument' specified @ creation    */
                      } else {
                          *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)(ptmr, callback_arg);           /* ... using the 'callback_arg' provided in call    */
                      } else {
                          *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    : none
************************************************************************************************************************
*/

#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);
}