embeddedsw/XilinxProcessorIPLib/drivers/dptx/examples/xdptx_timer_example.c

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/******************************************************************************/
/**
 *
 * @file xdptx_timer_example.c
 *
 * Contains a design example using the XDptx driver with a user-defined hook
 * for delay. The reasoning behind this is that MicroBlaze sleep is not very
 * accurate without a hardware timer. For systems that have a hardware timer,
 * the user may override the default MicroBlaze sleep with a function that will
 * use the hardware timer.
 *
 * @note        For this example to display output, the user will need to
 *              implement initialization of the system (Dptx_PlatformInit) and,
 *              after training is complete, implement configuration of the video
 *              stream source in order to provide the DisplayPort core with
 *              input (Dptx_ConfigureVidgen - called in xdptx_example_common.c).
 *              See XAPP1178 for reference.
 * @note        The functions Dptx_PlatformInit and Dptx_ConfigureVidgen are
 *              declared extern in xdptx_example_common.h and are left up to the
 *              user to implement.
 *
 * <pre>
 * MODIFICATION HISTORY:
 *
 * Ver   Who  Date     Changes
 * ----- ---- -------- -----------------------------------------------
 * 1.00a als  06/17/14 Initial creation.
 * </pre>
 *
*******************************************************************************/

/******************************* Include Files ********************************/

#include "xdptx.h"
#include "xdptx_example_common.h"
#include "xparameters.h"
#include "xstatus.h"
#include "xtmrctr.h"

/**************************** Constant Definitions ****************************/

#define DPTX_DEVICE_ID XPAR_DISPLAYPORT_0_DEVICE_ID

/**************************** Function Prototypes *****************************/

static void Dptx_CustomWaitUs(void *InstancePtr, u32 MicroSeconds);

/*************************** Variable Declarations ****************************/

XTmrCtr TimerCounterInst;

/**************************** Function Definitions ****************************/

int main(void)
{
        u32 Status;

        /* Do platform initialization here. This is hardware system specific -
         * it is up to the user to implement this function. */
        Dptx_PlatformInit();
        /*******************/

        /* Set a custom timer handler for improved delay accuracy.
         * Note: This only has an affect for MicroBlaze systems. */
        XDptx_SetUserTimerHandler(&DptxInstance, &Dptx_CustomWaitUs,
                                                        &TimerCounterInst);

        Status = Dptx_SetupExample(&DptxInstance, DPTX_DEVICE_ID);
        if (Status != XST_SUCCESS) {
                return XST_FAILURE;
        }

#if defined(TRAIN_ADAPTIVE)
        XDptx_EnableTrainAdaptive(&DptxInstance, 1);
#else
        XDptx_EnableTrainAdaptive(&DptxInstance, 0);
#endif
#if defined(TRAIN_HAS_REDRIVER)
        XDptx_SetHasRedriverInPath(&DptxInstance, 1);
#else
        XDptx_SetHasRedriverInPath(&DptxInstance, 0);
#endif

        /* A receiver must be connected at this point. */
        Dptx_Run(&DptxInstance, USE_LANE_COUNT, USE_LINK_RATE);

        /* Do not return in order to keep the program running. */
        while (1);
        return XST_SUCCESS;
}

static void Dptx_CustomWaitUs(void *InstancePtr, u32 MicroSeconds)
{
        XDptx *XDptx_InstancePtr = (XDptx *)InstancePtr;
        u32 TimerVal;

        XTmrCtr_Start(XDptx_InstancePtr->UserTimerPtr, 0);

        /* Wait specified number of useconds. */
        do {
                TimerVal = XTmrCtr_GetValue(XDptx_InstancePtr->UserTimerPtr, 0);
        }
        while (TimerVal < (MicroSeconds *
                        (XDptx_InstancePtr->TxConfig.SAxiClkHz / 1000000)));

        XTmrCtr_Stop(XDptx_InstancePtr->UserTimerPtr, 0);
}