FreeRTOS tick config for Zynq

/*
 * The application must provide a function that configures a peripheral to
 * create the FreeRTOS tick interrupt, then define configSETUP_TICK_INTERRUPT()
 * in FreeRTOSConfig.h to call the function.  This file contains a function
 * that is suitable for use on the Zynq SoC.
 */
void vConfigureTickInterrupt( void )
{
static XScuGic xInterruptController;    /* Interrupt controller instance */
BaseType_t xStatus;
extern void FreeRTOS_Tick_Handler( void );
XScuTimer_Config *pxTimerConfig;
XScuGic_Config *pxGICConfig;
const uint8_t ucRisingEdge = 3;

    /* This function is called with the IRQ interrupt disabled, and the IRQ
    interrupt should be left disabled.  It is enabled automatically when the
    scheduler is started. */

    /* Ensure XScuGic_CfgInitialize() has been called.  In this demo it has
    already been called from prvSetupHardware() in main(). */
    pxGICConfig = XScuGic_LookupConfig( XPAR_SCUGIC_SINGLE_DEVICE_ID );
    xStatus = XScuGic_CfgInitialize( &xInterruptController, pxGICConfig, pxGICConfig->CpuBaseAddress );
    configASSERT( xStatus == XST_SUCCESS );
    ( void ) xStatus; /* Remove compiler warning if configASSERT() is not defined. */

    /* The priority must be the lowest possible. */
    XScuGic_SetPriorityTriggerType( &xInterruptController, XPAR_SCUTIMER_INTR, portLOWEST_USABLE_INTERRUPT_PRIORITY << portPRIORITY_SHIFT, ucRisingEdge );

    /* Install the FreeRTOS tick handler. */
    xStatus = XScuGic_Connect( &xInterruptController, XPAR_SCUTIMER_INTR, (Xil_ExceptionHandler) FreeRTOS_Tick_Handler, ( void * ) &xTimer );
    configASSERT( xStatus == XST_SUCCESS );
    ( void ) xStatus; /* Remove compiler warning if configASSERT() is not defined. */

    /* Initialise the timer. */
    pxTimerConfig = XScuTimer_LookupConfig( XPAR_SCUTIMER_DEVICE_ID );
    xStatus = XScuTimer_CfgInitialize( &xTimer, pxTimerConfig, pxTimerConfig->BaseAddr );
    configASSERT( xStatus == XST_SUCCESS );
    ( void ) xStatus; /* Remove compiler warning if configASSERT() is not defined. */

    /* Enable Auto reload mode. */
    XScuTimer_EnableAutoReload( &xTimer );

    /* Load the timer counter register. */
    XScuTimer_LoadTimer( &xTimer, XSCUTIMER_CLOCK_HZ / configTICK_RATE_HZ );

    /* Start the timer counter and then wait for it to timeout a number of
    times. */
    XScuTimer_Start( &xTimer );

    /* Enable the interrupt for the xTimer in the interrupt controller. */
    XScuGic_Enable( &xInterruptController, XPAR_SCUTIMER_INTR );

    /* Enable the interrupt in the xTimer itself. */
    vClearTickInterrupt();
    XScuTimer_EnableInterrupt( &xTimer );
}