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

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/******************************************************************************/
/**
 *
 * @file xdptx_poll_example.c
 *
 * Contains a design example using the XDptx driver with polling. Once the
 * polling detects a hot-plug-detect event (DisplayPort cable is plugged/
 * unplugged or the monitor is turned on/off), the main link will be trained.
 *
 * @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"

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

#define DPTX_DEVICE_ID XPAR_DISPLAYPORT_0_DEVICE_ID

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

static void Dptx_HpdPoll(XDptx *InstancePtr);

/**************************** 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();
        /******************/

        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. */
        while (1) {
                /* Continuously poll for HPD events. */
                Dptx_HpdPoll(&DptxInstance);
        }

        return XST_SUCCESS;
}

static void Dptx_HpdPoll(XDptx *InstancePtr)
{
        u32 InterruptSignalState;
        u32 InterruptStatus;
        u32 HpdState;
        u32 HpdEvent;
        u32 HpdPulseDetected;
        u32 HpdDuration;

        /* Read interrupt registers. */
        InterruptSignalState = XDptx_ReadReg(InstancePtr->TxConfig.BaseAddr,
                                                XDPTX_INTERRUPT_SIG_STATE);
        InterruptStatus = XDptx_ReadReg(InstancePtr->TxConfig.BaseAddr,
                                                XDPTX_INTERRUPT_STATUS);

        /* Check for HPD events. */
        HpdState = InterruptSignalState &
                                XDPTX_INTERRUPT_SIG_STATE_HPD_STATE_MASK;
        HpdEvent = InterruptStatus & XDPTX_INTERRUPT_STATUS_HPD_EVENT_MASK;
        HpdPulseDetected = InterruptStatus &
                                XDPTX_INTERRUPT_STATUS_HPD_PULSE_DETECTED_MASK;
        if (HpdPulseDetected) {
                HpdDuration = XDptx_ReadReg(InstancePtr, XDPTX_HPD_DURATION);
        }

        /* HPD event handling. */
        if (HpdState && HpdEvent) {
                xil_printf("+===> HPD connection event detected.\n");

                /* Initiate link training. */
                Dptx_Run(&DptxInstance, USE_LANE_COUNT, USE_LINK_RATE);
        }
        else if (HpdState && HpdPulseDetected && (HpdDuration >= 250)) {
                xil_printf("===> HPD pulse detected.\n");

                /* Re-train if needed. */
                Dptx_Run(InstancePtr, USE_LANE_COUNT, USE_LINK_RATE);
        }
        else if (!HpdState && HpdEvent) {
                xil_printf("+===> HPD disconnection event detected.\n\n");

                /* Disable main link. */
                XDptx_DisableMainLink(InstancePtr);
        }
}