* @param    InstancePtr is a pointer to the XIntc instance to be worked on.* @param    Id contains the ID of the interrupt source and should be in the*           range of 0 to XPAR_INTC_MAX_NUM_INTR_INPUTS - 1 with 0 being the*           highest priority interrupt.* @param    Handler to the handler for that interrupt.* @param    CallBackRef is the callback reference, usually the instance pointer*           of the connecting driver.** @return** - XST_SUCCESS if the handler was connected correctly.** @note** WARNING: The handler provided as an argument will overwrite any handler* that was previously connected.*****************************************************************************/XStatus XIntc_Connect(XIntc *InstancePtr, Xuint8 Id,                      XInterruptHandler Handler, void *CallBackRef){    /*     * assert the arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    XASSERT_NONVOID(Id < XPAR_INTC_MAX_NUM_INTR_INPUTS);    XASSERT_NONVOID(Handler != XNULL);    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    /*     * the Id is used as an index into the table to select the proper handler     */    InstancePtr->CfgPtr->HandlerTable[Id].Handler = Handler;    InstancePtr->CfgPtr->HandlerTable[Id].CallBackRef = CallBackRef;    return XST_SUCCESS;}/*****************************************************************************//**** Updates the interrupt table with the Null Handler and XNULL arguments at the* location pointed at by the Id. This effectively disconnects that interrupt* source from any handler. The interrupt is disabled also.** @param    InstancePtr is a pointer to the XIntc instance to be worked on.* @param    Id contains the ID of the interrupt source and should be in the*           range of 0 to XPAR_INTC_MAX_NUM_INTR_INPUTS - 1 with 0 being the*           highest priority interrupt.** @return** None.** @note** None.*****************************************************************************/void XIntc_Disconnect(XIntc *InstancePtr, Xuint8 Id){    Xuint32 CurrentIER;    Xuint32 Mask;    /*     * assert the arguments     */    XASSERT_VOID(InstancePtr != XNULL);    XASSERT_VOID(Id < XPAR_INTC_MAX_NUM_INTR_INPUTS);    XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    /* disable the interrupt such that it won't occur while disconnecting     * the handler, only disable the specified interrupt id without modifying     * the other interrupt ids     */    CurrentIER = XIntc_In32(InstancePtr->BaseAddress + XIN_IER_OFFSET);    Mask = XIntc_BitPosMask[Id];      /* convert from integer id to bit mask */    XIntc_Out32(InstancePtr->BaseAddress + XIN_IER_OFFSET,              (CurrentIER & ~Mask));    /* disconnect the handler and connect a stub, the callback reference     * must be set to this instance to allow unhandled interrupts to be     * tracked     */    InstancePtr->CfgPtr->HandlerTable[Id].Handler = StubHandler;    InstancePtr->CfgPtr->HandlerTable[Id].CallBackRef = InstancePtr;}/*****************************************************************************//**** Enables the interrupt source provided as the argument Id. Any pending* interrupt condition for the specified Id will occur after this function is* called.** @param    InstancePtr is a pointer to the XIntc instance to be worked on.* @param    Id contains the ID of the interrupt source and should be in the*           range of 0 to XPAR_INTC_MAX_NUM_INTR_INPUTS - 1 with 0 being the*           highest priority interrupt.** @return** None.** @note** None.*****************************************************************************/void XIntc_Enable(XIntc *InstancePtr, Xuint8 Id){    Xuint32 CurrentIER;    Xuint32 Mask;    /*     * assert the arguments     */    XASSERT_VOID(InstancePtr != XNULL);    XASSERT_VOID(Id < XPAR_INTC_MAX_NUM_INTR_INPUTS);    XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    /*     * the Id is used to create the appropriate mask for the     * desired bit position. Id currently limited to 0 - 31     */    Mask = XIntc_BitPosMask[Id];    /*     * enable the selected interrupt source by reading the interrupt enable     * register and then modifying only the specified interrupt id enable     */    CurrentIER = XIntc_In32(InstancePtr->BaseAddress + XIN_IER_OFFSET);    XIntc_Out32(InstancePtr->BaseAddress + XIN_IER_OFFSET,              (CurrentIER | Mask));}/*****************************************************************************//**** Disables the interrupt source provided as the argument Id such that the* interrupt controller will not cause interrupts for the specified Id. The* interrupt controller will continue to hold an interrupt condition for the* Id, but will not cause an interrupt.** @param    InstancePtr is a pointer to the XIntc instance to be worked on.* @param    Id contains the ID of the interrupt source and should be in the*           range of 0 to XPAR_INTC_MAX_NUM_INTR_INPUTS - 1 with 0 being the*           highest priority interrupt.** @return** None.** @note** None.*****************************************************************************/void XIntc_Disable(XIntc *InstancePtr, Xuint8 Id){    Xuint32 CurrentIER;    Xuint32 Mask;    /*     * assert the arguments     */    XASSERT_VOID(InstancePtr != XNULL);    XASSERT_VOID(Id < XPAR_INTC_MAX_NUM_INTR_INPUTS);    XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    /*     * the Id is used to create the appropriate mask for the     * desired bit position. Id currently limited to 0 - 31     */    Mask = XIntc_BitPosMask[Id];    /*     * disable the selected interrupt source by reading the interrupt enable     * register and then modifying only the specified interrupt id     */    CurrentIER = XIntc_In32(InstancePtr->BaseAddress + XIN_IER_OFFSET);    XIntc_Out32(InstancePtr->BaseAddress + XIN_IER_OFFSET,              (CurrentIER & ~Mask));}/*****************************************************************************//**** Acknowledges the interrupt source provided as the argument Id. When the* interrupt is acknowledged, it causes the interrupt controller to clear its* interrupt condition.** @param    InstancePtr is a pointer to the XIntc instance to be worked on.* @param    Id contains the ID of the interrupt source and should be in the*           range of 0 to XPAR_INTC_MAX_NUM_INTR_INPUTS - 1 with 0 being the*           highest priority interrupt.** @return** None.** @note** None.*****************************************************************************/void XIntc_Acknowledge(XIntc *InstancePtr, Xuint8 Id){    Xuint32 Mask;    /*     * assert the arguments     */    XASSERT_VOID(InstancePtr != XNULL);    XASSERT_VOID(Id < XPAR_INTC_MAX_NUM_INTR_INPUTS);    XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    /*     * the Id is used to create the appropriate mask for the     * desired bit position. Id currently limited to 0 - 31     */    Mask = XIntc_BitPosMask[Id];    /*     * acknowledge the selected interrupt source, no read of the acknowledge     * register is necessary since only the bits set in the mask will be     * affected by the write     */    XIntc_Out32(InstancePtr->BaseAddress + XIN_IAR_OFFSET, Mask);}/*****************************************************************************//**** A stub for the asynchronous callback. The stub is here in case the upper* layers forget to set the handler.** @param    CallBackRef is a pointer to the upper layer callback reference** @return** None.** @note** None.*******************************************************************************/static void StubHandler(void *CallBackRef){    /*     * verify that the inputs are valid     */    XASSERT_VOID(CallBackRef != XNULL);    /*     * indicate another unhandled interrupt for stats     */    ((XIntc *)CallBackRef)->UnhandledInterrupts++;}/*****************************************************************************//**** Looks up the device configuration based on the unique device ID. A table* contains the configuration info for each device in the system.** @param    DeviceId is the unique identifier for a device.** @return** A pointer to the XIntc configuration structure for the specified device, or* XNULL if the device was not found.** @note** None.*******************************************************************************/XIntc_Config *XIntc_LookupConfig(Xuint16 DeviceId){    XIntc_Config *CfgPtr = XNULL;    int i;    for (i=0; i < XPAR_XINTC_NUM_INSTANCES; i++)    {        if (XIntc_ConfigTable[i].DeviceId == DeviceId)        {            CfgPtr = &XIntc_ConfigTable[i];            break;        }    }    return CfgPtr;}