Xilinx Processor IP Library

Software Drivers

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xdptx.h File Reference

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Detailed Description

The Xilinx DisplayPort transmitter (DPTX) driver. This driver supports the Xilinx DisplayPort soft IP core in source (TX) mode. This driver follows the DisplayPort 1.2a specification.

The Xilinx DisplayPort soft IP supports the following features:

• 1, 2, or 4 lanes.
• A link rate of 1.62, 2.70, or 5.40Gbps per lane.
• 1, 2, or 4 pixel-wide video interfaces.
• RGB and YCbCr color space.
• Up to 16 bits per component.
• Up to 4Kx2K monitor resolution.
• Auto lane rate and width negotiation.
• I2C over a 1Mb/s AUX channel.
• Secondary channel audio support (2 channels).
• 4 independent video multi-streams.

The Xilinx DisplayPort soft IP does not support the following features:

• The automated test feature.
• Audio (3-8 channel).
• FAUX.
• Bridging function.
• MST audio.
• eDP optional features.
• iDP.
• GTC.

DisplayPort overview

A DisplayPort link consists of:

• A unidirectional main link which is used to transport isochronous data streams such as video and audio. The main link may use 1, 2, or 4 lanes at a link rate of 1.62, 2.70, or 5.40Gbps per lane. The link needs to be trained prior to sending streams.
• An auxiliary (AUX) channel is a 1MBps bidirectional channel used for link training, link management, and device control.
• A hot-plug-detect (HPD) signal line is used to determine whether a DisplayPort connection exists between the DisplayPort TX connector and an RX device. It is serves as an interrupt request by the RX device.

Driver description

The device driver enables higher-level software (e.g., an application) to configure and control a DisplayPort TX soft IP, communicate and control an RX device/sink monitor over the AUX channel, and to initialize and transmit data streams over the main link.

This driver implements link layer functionality: a Link Policy Maker (LPM) and a Stream Policy Maker (SPM) as per the DisplayPort 1.2a specification.

• The LPM manages the main link and is responsible for keeping the link synchronized. It will establish a link with a downstream RX device by undergoing a link training sequence which consists of:
  • Clock recovery: The clock needs to be recovered and PLLs need to be locked for all lanes.
  • Channel equalization: All lanes need to achieve channel equalization and and symbol lock, as well as for interlane alignment to take place.
• The SPM manages transportation of an isochronous stream. That is, it will initialize and maintain a video stream, establish a virtual channel to a sink monitor, and transmit the stream.

Using AUX transactions to read/write from/to the sink's DisplayPort Configuration Data (DPCD) address space, the LPM obtains the link capabilities, obtains link configuration and link and sink status, and configures and controls the link and sink. The main link is trained this way.

I2C-over-AUX transactions are used to obtain the sink's Extended Display Identification Data (EDID) which give information on the display capabilities of the monitor. The SPM may use this information to determine what available screen resolutions and video timing are possible.

Device configuration

The device can be configured in various ways during the FPGA implementation process. Configuration parameters are stored in the xdptx_g.c file which is generated when compiling the board support package (BSP). A table is defined where each entry contains configuration information for the DisplayPort instances present in the system. This information includes parameters that are defined in the driver's data/dptx.tcl file such as the base address of the memory-mapped device and the maximum number of lanes, maximum link rate, and video interface that the DisplayPort instance supports, among others.

Interrupt processing

DisplayPort interrupts occur on the HPD signal line when the DisplayPort cable is connected/disconnected or when the RX device sends a pulse. The user hardware design must contain an interrupt controller which the DisplayPort TX instance's interrupt signal is connected to. The user application must enable interrupts in the system and set up the interrupt controller such that the XDptx_HpdInterruptHandler handler will service DisplayPort interrupts. When the XDptx_HpdInterruptHandler function is invoked, the handler will identify what type of DisplayPort interrupt has occurred, and will call either the HPD event handler function or the HPD pulse handler function, depending on whether a an HPD event on an HPD pulse event occurred.

The DisplayPort TX's XDPTX_INTERRUPT_STATUS register indicates the type of interrupt that has occured, and the XDptx_HpdInterruptHandler will use this information to decide which handler to call. An HPD event is identified if bit XDPTX_INTERRUPT_STATUS_HPD_EVENT_MASK is set, and an HPD pulse is identified from the XDPTX_INTERRUPT_STATUS_HPD_PULSE_DETECTED_MASK bit.

The HPD event handler may be set up by using the XDptx_SetHpdEventHandler function and, for the HPD pulse handler, the XDptx_SetHpdPulseHandler function.

Multi-stream transport (MST) mode

The driver handles MST mode functionality, including sideband messaging, topology discovery, virtual channel payload ID table management, and directing streams to different sinks.

MST testing has been done at all possible link rate/lane count/topology/ resolution/color depth combinations with each setting using following values:

• Link rate: 1.62, 2.70, and 5.40Gbps per lane.
• Lane count: 1, 2, and 4 lanes.
• Number of sink displays: 1, 2, 3, and 4 sink displays in both a daisy-chain configuration and in a configuration using a combination of a 1-to-3 hub and daisy-chain. Each stream was using the same resolution.
• Resolutions (60Hz): 640x480, 800x600, 1024x768, 1280x800, 1280x1024, 1360x768, 1400x1050, 1680x1050, 1920x1080, 1920x2160, and 3840x2160.
• Color depths: 18, 24, 30, 36, and 48 bits per pixel.

Audio

The driver does not handle audio. For an example as to how to configure and transmit audio, examples/xdptx_audio_example.c illustrates the required sequence. The user will need to configure the audio source connected to the Displayport TX instance and set up the audio info frame as per user requirements.

Asserts

Asserts are used within all Xilinx drivers to enforce constraints on argument values. Asserts can be turned off on a system-wide basis by defining, at compile time, the NDEBUG identifier. By default, asserts are turned on and it is recommended that application developers leave asserts on during development.

Limitations

• For MST mode to correctly display, the current version of the driver requires that each of the DisplayPort TX streams be allocated without skipping streams (i.e. assign stream 1, stream 2, and stream 3 - problems were experienced if skipping stream 2 and assigning stream 4 instead). skipping monitors in a daisy chain is OK as long as they are assigned to streams in order.
• In MST mode, the current version of the driver does not support removal of an allocated stream from the virtual channel payload ID table without clearing the entire table.
• Some sideband messages have not been implemented in the current version of the driver for MST mode. Notably, reception of a CONNECTION_STATUS_NOTIFY sideband message.
• The driver does not handle audio. See the audio example in the driver examples directory for the required sequence for enabling audio.

Note:

For a 5.4Gbps link rate, a high performance 7 series FPGA is required with a speed grade of -2 or -3.

 MODIFICATION HISTORY:

 Ver   Who  Date     Changes
 ----- ---- -------- -----------------------------------------------
 1.0   als  05/17/14 Initial release.
       als  08/03/14 Initial MST addition.
 2.0   als  09/21/14 Added XDptx_DiscoverTopology function and changed
                     XDptx_IsConnected from macro to function.
 3.0   als  12/16/14 Updated to use common video library.
                     Added topology reordering functions:
                         XDptx_TopologySwapSinks,
                         XDptx_TopologySortSinksByTiling
                     Added wrapper functions for remote DPCD/I2C read/writes:
                         XDptx_RemoteDpcdRead, XDptx_RemoteDpcdWrite,
                         XDptx_RemoteIicRead, XDptx_RemoteIicWrite
                     Added EDID utility functions:
                         XDptx_GetRemoteEdid, XDptx_GetEdidBlock,
                         XDptx_GetRemoteEdidBlock,
                         XDptx_GetRemoteEdidDispIdExt,
                         XDptx_GetDispIdDataBlock,
                         XDptx_GetRemoteTiledDisplayDb
                     Remove unused arguments from functions:
                         LinkCountTotal, RelativeAddress from
                             XDptx_AllocatePayloadVcIdTable
                         RegStartAddress from XDptx_IicWrite
 

#include "xdptx_hw.h"
#include "xil_assert.h"
#include "xil_types.h"
#include "xvid.h"

Classes
struct	XDptx_Config
struct	XDptx_SinkConfig
struct	XDptx_LinkConfig
struct	XDptx_MainStreamAttributes
struct	XDptx_MstStream
struct	XDptx_BoardChar
struct	XDptx_TopologyNode
struct	XDptx_Topology
struct	XDptx_SbMsgLinkAddressReplyPortDetail
struct	XDptx_SbMsgLinkAddressReplyDeviceInfo
struct	XDptx
Typedefs
typedef void(*)	XDptx_TimerHandler (void *InstancePtr, u32 MicroSeconds)
typedef void(*)	XDptx_HpdEventHandler (void *InstancePtr)
typedef void(*)	XDptx_HpdPulseHandler (void *InstancePtr)
Functions
u32	XDptx_InitializeTx (XDptx *InstancePtr)
void	XDptx_CfgInitialize (XDptx *InstancePtr, XDptx_Config *ConfigPtr, u32 EffectiveAddr)
u32	XDptx_GetRxCapabilities (XDptx *InstancePtr)
u32	XDptx_CfgMainLinkMax (XDptx *InstancePtr)
u32	XDptx_EstablishLink (XDptx *InstancePtr)
u32	XDptx_CheckLinkStatus (XDptx *InstancePtr, u8 LaneCount)
void	XDptx_EnableTrainAdaptive (XDptx *InstancePtr, u8 Enable)
void	XDptx_SetHasRedriverInPath (XDptx *InstancePtr, u8 Set)
void	XDptx_CfgTxVsOffset (XDptx *InstancePtr, u8 Offset)
void	XDptx_CfgTxVsLevel (XDptx *InstancePtr, u8 Level, u8 TxLevel)
void	XDptx_CfgTxPeLevel (XDptx *InstancePtr, u8 Level, u8 TxLevel)
u32	XDptx_AuxRead (XDptx *InstancePtr, u32 DpcdAddress, u32 BytesToRead, void *ReadData)
u32	XDptx_AuxWrite (XDptx *InstancePtr, u32 DpcdAddress, u32 BytesToWrite, void *WriteData)
u32	XDptx_IicRead (XDptx *InstancePtr, u8 IicAddress, u16 Offset, u16 BytesToRead, void *ReadData)
u32	XDptx_IicWrite (XDptx *InstancePtr, u8 IicAddress, u8 BytesToWrite, void *WriteData)
u32	XDptx_SetDownspread (XDptx *InstancePtr, u8 Enable)
u32	XDptx_SetEnhancedFrameMode (XDptx *InstancePtr, u8 Enable)
u32	XDptx_SetLaneCount (XDptx *InstancePtr, u8 LaneCount)
u32	XDptx_SetLinkRate (XDptx *InstancePtr, u8 LinkRate)
u32	XDptx_SetScrambler (XDptx *InstancePtr, u8 Enable)
u32	XDptx_IsConnected (XDptx *InstancePtr)
void	XDptx_EnableMainLink (XDptx *InstancePtr)
void	XDptx_DisableMainLink (XDptx *InstancePtr)
void	XDptx_ResetPhy (XDptx *InstancePtr, u32 Reset)
void	XDptx_WaitUs (XDptx *InstancePtr, u32 MicroSeconds)
void	XDptx_SetUserTimerHandler (XDptx *InstancePtr, XDptx_TimerHandler CallbackFunc, void *CallbackRef)
void	XDptx_CfgMsaRecalculate (XDptx *InstancePtr, u8 Stream)
void	XDptx_CfgMsaUseStandardVideoMode (XDptx *InstancePtr, u8 Stream, XVid_VideoMode VideoMode)
void	XDptx_CfgMsaUseEdidPreferredTiming (XDptx *InstancePtr, u8 Stream, u8 *Edid)
void	XDptx_CfgMsaUseCustom (XDptx *InstancePtr, u8 Stream, XDptx_MainStreamAttributes *MsaConfigCustom, u8 Recalculate)
void	XDptx_CfgMsaSetBpc (XDptx *InstancePtr, u8 Stream, u8 BitsPerColor)
void	XDptx_CfgMsaEnSynchClkMode (XDptx *InstancePtr, u8 Stream, u8 Enable)
void	XDptx_SetVideoMode (XDptx *InstancePtr, u8 Stream)
void	XDptx_ClearMsaValues (XDptx *InstancePtr, u8 Stream)
void	XDptx_SetMsaValues (XDptx *InstancePtr, u8 Stream)
void	XDptx_SetHpdEventHandler (XDptx *InstancePtr, XDptx_HpdEventHandler CallbackFunc, void *CallbackRef)
void	XDptx_SetHpdPulseHandler (XDptx *InstancePtr, XDptx_HpdPulseHandler CallbackFunc, void *CallbackRef)
void	XDptx_HpdInterruptHandler (XDptx *InstancePtr)
u32	XDptx_SelfTest (XDptx *InstancePtr)
XDptx_Config *	XDptx_LookupConfig (u16 DeviceId)
void	XDptx_MstCfgModeEnable (XDptx *InstancePtr)
void	XDptx_MstCfgModeDisable (XDptx *InstancePtr)
u32	XDptx_MstCapable (XDptx *InstancePtr)
u32	XDptx_MstEnable (XDptx *InstancePtr)
u32	XDptx_MstDisable (XDptx *InstancePtr)
void	XDptx_MstCfgStreamEnable (XDptx *InstancePtr, u8 Stream)
void	XDptx_MstCfgStreamDisable (XDptx *InstancePtr, u8 Stream)
u8	XDptx_MstStreamIsEnabled (XDptx *InstancePtr, u8 Stream)
void	XDptx_SetStreamSelectFromSinkList (XDptx *InstancePtr, u8 Stream, u8 SinkNum)
void	XDptx_SetStreamSinkRad (XDptx *InstancePtr, u8 Stream, u8 LinkCountTotal, u8 *RelativeAddress)
u32	XDptx_DiscoverTopology (XDptx *InstancePtr)
u32	XDptx_FindAccessibleDpDevices (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress)
void	XDptx_TopologySwapSinks (XDptx *InstancePtr, u8 Index0, u8 Index1)
void	XDptx_TopologySortSinksByTiling (XDptx *InstancePtr)
u32	XDptx_RemoteDpcdRead (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 DpcdAddress, u32 BytesToRead, u8 *ReadData)
u32	XDptx_RemoteDpcdWrite (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 DpcdAddress, u32 BytesToWrite, u8 *WriteData)
u32	XDptx_RemoteIicRead (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 IicAddress, u16 Offset, u16 BytesToRead, u8 *ReadData)
u32	XDptx_RemoteIicWrite (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 IicAddress, u8 BytesToWrite, u8 *WriteData)
u32	XDptx_AllocatePayloadStreams (XDptx *InstancePtr)
u32	XDptx_AllocatePayloadVcIdTable (XDptx *InstancePtr, u8 VcId, u8 Ts)
u32	XDptx_ClearPayloadVcIdTable (XDptx *InstancePtr)
u32	XDptx_SendSbMsgRemoteDpcdWrite (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 DpcdAddress, u32 BytesToWrite, u8 *WriteData)
u32	XDptx_SendSbMsgRemoteDpcdRead (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 DpcdAddress, u32 BytesToRead, u8 *ReadData)
u32	XDptx_SendSbMsgRemoteIicWrite (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 IicDeviceId, u8 BytesToWrite, u8 *WriteData)
u32	XDptx_SendSbMsgRemoteIicRead (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 IicDeviceId, u8 Offset, u8 BytesToRead, u8 *ReadData)
u32	XDptx_SendSbMsgLinkAddress (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, XDptx_SbMsgLinkAddressReplyDeviceInfo *DeviceInfo)
u32	XDptx_SendSbMsgEnumPathResources (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u16 *AvailPbn, u16 *FullPbn)
u32	XDptx_SendSbMsgAllocatePayload (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 VcId, u16 Pbn)
u32	XDptx_SendSbMsgClearPayloadIdTable (XDptx *InstancePtr)
void	XDptx_WriteGuid (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 Guid[4])
void	XDptx_GetGuid (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u32 *Guid)
u32	XDptx_GetEdid (XDptx *InstancePtr, u8 *Edid)
u32	XDptx_GetRemoteEdid (XDptx *InstancePtr, u8 LinkCountTotal, u8 *RelativeAddress, u8 *Edid)
u32	XDptx_GetEdidBlock (XDptx *InstancePtr, u8 *Data, u8 BlockNum)
u32	XDptx_GetRemoteEdidBlock (XDptx *InstancePtr, u8 *Data, u8 BlockNum, u8 LinkCountTotal, u8 *RelativeAddress)
u32	XDptx_GetRemoteEdidDispIdExt (XDptx *InstancePtr, u8 *Data, u8 LinkCountTotal, u8 *RelativeAddress)
u32	XDptx_GetDispIdDataBlock (u8 *DisplayIdRaw, u8 SectionTag, u8 **DataBlockPtr)
u32	XDptx_GetRemoteTiledDisplayDb (XDptx *InstancePtr, u8 *EdidExt, u8 LinkCountTotal, u8 *RelativeAddress, u8 **DataBlockPtr)

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Typedef Documentation

typedef void(*) XDptx_HpdEventHandler(void *InstancePtr)

Callback type which represents the handler for a Hot-Plug-Detect (HPD) event interrupt.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Note:

None.

typedef void(*) XDptx_HpdPulseHandler(void *InstancePtr)

Callback type which represents the handler for a Hot-Plug-Detect (HPD) pulse interrupt.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Note:

None.

typedef void(*) XDptx_TimerHandler(void *InstancePtr, u32 MicroSeconds)

Callback type which represents a custom timer wait handler. This is only used for Microblaze since it doesn't have a native sleep function. To avoid dependency on a hardware timer, the default wait functionality is implemented using loop iterations; this isn't too accurate. If a custom timer handler is used, the user may implement their own wait implementation using a hardware timer (see example/) for better accuracy.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	MicroSeconds	is the number of microseconds to be passed to the timer function.

Note:

None.

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Function Documentation

u32 XDptx_AllocatePayloadStreams

(

XDptx *

InstancePtr

)

This function will allocate bandwidth for all enabled stream.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the payload ID tables were successfully updated with the new allocation.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, waiting for the payload ID table to be cleared or updated, or an AUX request timed out.
  • XST_BUFFER_TOO_SMALL if there is not enough free timeslots in the payload ID table for the requested Ts.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of a sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_AllocatePayloadVcIdTable	(	XDptx *	InstancePtr,
		u8	VcId,
		u8	Ts
	)

This function will allocate a bandwidth for a virtual channel in the payload ID table in both the DisplayPort TX and the downstream DisplayPort devices on the path to the target device specified by LinkCountTotal and RelativeAddress.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	VcId	is the unique virtual channel ID to allocate into the payload ID tables.
	Ts	is the number of timeslots to allocate in the payload ID tables.

Returns:

• XST_SUCCESS if the payload ID tables were successfully updated with the new allocation.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_BUFFER_TOO_SMALL if there is not enough free timeslots in the payload ID table for the requested Ts.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of a sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_AuxRead	(	XDptx *	InstancePtr,
		u32	DpcdAddress,
		u32	BytesToRead,
		void *	ReadData
	)

This function issues a read request over the AUX channel that will read from the RX device's DisplayPort Configuration Data (DPCD) address space. The read message will be divided into multiple transactions which read a maximum of 16 bytes each.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	DpcdAddress	is the starting address to read from the RX device.
	BytesToRead	is the number of bytes to read from the RX device.
	ReadData	is a pointer to the data buffer that will be filled with read data.

Returns:

• XST_SUCCESS if the AUX read request was successfully acknowledged.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if the AUX request timed out.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_AuxWrite	(	XDptx *	InstancePtr,
		u32	DpcdAddress,
		u32	BytesToWrite,
		void *	WriteData
	)

This function issues a write request over the AUX channel that will write to the RX device's DisplayPort Configuration Data (DPCD) address space. The write message will be divided into multiple transactions which write a maximum of 16 bytes each.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	DpcdAddress	is the starting address to write to the RX device.
	BytesToWrite	is the number of bytes to write to the RX device.
	WriteData	is a pointer to the data buffer that contains the data to be written to the RX device.

Returns:

• XST_SUCCESS if the AUX write request was successfully acknowledged.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if the AUX request timed out.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_CfgInitialize	(	XDptx *	InstancePtr,
		XDptx_Config *	ConfigPtr,
		u32	EffectiveAddr
	)

This function retrieves the configuration for this DisplayPort TX instance and fills in the InstancePtr->Config structure.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	ConfigPtr	is a pointer to the configuration structure that will be used to copy the settings from.
	EffectiveAddr	is the device base address in the virtual memory space. If the address translation is not used, then the physical address is passed.

Returns:

None.

Note:

Unexpected errors may occur if the address mapping is changed after this function is invoked.

u32 XDptx_CfgMainLinkMax

(

XDptx *

InstancePtr

)

This function determines the common capabilities between the DisplayPort TX core and the RX device.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if main link settings were successfully set.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_CfgMsaEnSynchClkMode	(	XDptx *	InstancePtr,
		u8	Stream,
		u8	Enable
	)

This function enables or disables synchronous clock mode for a video stream.

Parameters:

	InstancePtr	is a pointer to the XDptx instance
	Stream	is the stream number for which to enable or disable synchronous clock mode.
	Enable	if set to 1, will enable synchronous clock mode. Otherwise, if set to 0, synchronous clock mode will be disabled.

Returns:

None.

Note:

None.

void XDptx_CfgMsaRecalculate	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function calculates the following Main Stream Attributes (MSA):

• Transfer unit size
• User pixel width
• Horizontal start
• Vertical start
• Horizontal total clock
• Vertical total clock
• Misc0
• Misc1
• Data per lane
• Average number of bytes per transfer unit
• Number of initial wait cycles These values are derived from:
• Bits per color
• Horizontal resolution
• Vertical resolution
• Pixel clock (in KHz)
• Horizontal sync polarity
• Vertical sync polarity
• Horizontal front porch
• Horizontal sync pulse width
• Horizontal back porch
• Vertical front porch
• Vertical sync pulse width
• Vertical back porch

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number for which to calculate the MSA values.

Returns:

None.

Note:

The MsaConfig structure is modified with the new, calculated values. The main stream attributes that were used to derive the calculated values are untouched in the MsaConfig structure.

void XDptx_CfgMsaSetBpc	(	XDptx *	InstancePtr,
		u8	Stream,
		u8	BitsPerColor
	)

This function sets the bits per color value of the video stream.

Parameters:

	InstancePtr	is a pointer to the XDptx instance
	Stream	is the stream number for which to set the color depth.
	BitsPerColor	is the new number of bits per color to use.

Returns:

None.

Note:

The InstancePtr->MsaConfig structure is modified to reflect the new main stream attributes associated with a new bits per color value.

void XDptx_CfgMsaUseCustom	(	XDptx *	InstancePtr,
		u8	Stream,
		XDptx_MainStreamAttributes *	MsaConfigCustom,
		u8	Recalculate
	)

This function takes a the main stream attributes from MsaConfigCustom and copies them into InstancePtr->MsaConfig. If desired, given a base set of attributes, the rest of the attributes may be derived. The minimal required main stream attributes (MSA) that must be contained in the MsaConfigCustom structure are:

• Pixel clock (in KHz)
• Horizontal sync polarity
• Vertical sync polarity
• Horizontal sync pulse width
• Vertical sync pulse width
• Horizontal resolution
• Vertical resolution
• Vertical back porch
• Vertical front porch
• Horizontal back porch
• Horizontal front porch

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number for which the MSA values will be used for.
	MsaConfigCustom	is the structure that will be used to copy the main stream attributes from (into InstancePtr->MsaConfig).
	Recalculate	is a boolean enable that determines whether or not the main stream attributes should be recalculated.

Returns:

None.

Note:

The InstancePtr->MsaConfig structure is modified with the new values.

void XDptx_CfgMsaUseEdidPreferredTiming	(	XDptx *	InstancePtr,
		u8	Stream,
		u8 *	Edid
	)

This function sets the main stream attribute values in the configuration structure to match the preferred timing of the sink monitor. This Preferred Timing Mode (PTM) information is stored in the sink's Extended Display Identification Data (EDID).

Parameters:

	InstancePtr	is a pointer to the XDptx instance
	Stream	is the stream number for which the MSA values will be used for.
	Edid	is a pointer to the Edid to use for the specified stream.

Returns:

None.

Note:

The InstancePtr->MsaConfig structure is modified to reflect the main stream attribute values associated to the preferred timing of the sink monitor.

void XDptx_CfgMsaUseStandardVideoMode	(	XDptx *	InstancePtr,
		u8	Stream,
		XVid_VideoMode	VideoMode
	)

This function sets the Main Stream Attribute (MSA) values in the configuration structure to match one of the standard display mode timings from the XDptx_DmtModes[] standard Display Monitor Timing (DMT) table. The XDptx_VideoMode enumeration in xdptx.h lists the available video modes.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number for which the MSA values will be used for.
	VideoMode	is one of the enumerated standard video modes that is used to determine the MSA values to be used.

Returns:

None.

Note:

The InstancePtr->MsaConfig structure is modified to reflect the MSA values associated to the specified video mode.

void XDptx_CfgTxPeLevel	(	XDptx *	InstancePtr,
		u8	Level,
		u8	TxLevel
	)

This function sets the pre-emphasis level value in the DisplayPort TX that will be used during link training for a given pre-emphasis training level.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Level	is the pre-emphasis training level to set the DisplayPort TX level for.
	TxLevel	is the DisplayPort TX pre-emphasis level value to be used during link training.

Returns:

None.

Note:

There are 32 possible pre-emphasis levels in the DisplayPort TX core that map to 4 possible pre-emphasis training levels in the RX device.

void XDptx_CfgTxVsLevel	(	XDptx *	InstancePtr,
		u8	Level,
		u8	TxLevel
	)

This function sets the voltage swing level value in the DisplayPort TX that will be used during link training for a given voltage swing training level.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Level	is the voltage swing training level to set the DisplayPort TX level for.
	TxLevel	is the DisplayPort TX voltage swing level value to be used during link training.

Returns:

None.

Note:

There are 16 possible voltage swing levels in the DisplayPort TX core that map to 4 possible voltage swing training levels in the RX device.

void XDptx_CfgTxVsOffset	(	XDptx *	InstancePtr,
		u8	Offset
	)

This function sets the voltage swing offset to use during training when no redriver exists. The offset will be added to the DisplayPort TX's voltage swing level value when pre-emphasis is used (when the pre-emphasis level not equal to 0).

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Offset	is the value to set for the voltage swing offset.

Returns:

None.

Note:

None.

u32 XDptx_CheckLinkStatus	(	XDptx *	InstancePtr,
		u8	LaneCount
	)

This function checks if the reciever's DisplayPort Configuration Data (DPCD) indicates the reciever has achieved and maintained clock recovery, channel equalization, symbol lock, and interlane alignment for all lanes currently in use.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LaneCount	is the number of lanes to check.

Returns:

• XST_SUCCESS if the RX device has maintained clock recovery, channel equalization, symbol lock, and interlane alignment.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_ClearMsaValues	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function clears the main stream attributes registers of the DisplayPort TX core.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number for which to clear the MSA values.

Returns:

None.

Note:

None.

u32 XDptx_ClearPayloadVcIdTable

(

XDptx *

InstancePtr

)

This function will clear the virtual channel payload ID table in both the DisplayPort TX and all downstream DisplayPort devices.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the payload ID tables were successfully cleared.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of a sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

void XDptx_DisableMainLink

(

XDptx *

InstancePtr

)

This function disables the main link.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

None.

u32 XDptx_DiscoverTopology

(

XDptx *

InstancePtr

)

This function will explore the DisplayPort topology of downstream devices connected to the DisplayPort TX. It will recursively go through each branch device, obtain its information by sending a LINK_ADDRESS sideband message, and add this information to the the topology's node table. For each sink device connected to a branch's downstream port, this function will obtain the details of the sink, add it to the topology's node table, as well as add it to the topology's sink list.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the topology discovery is successful.
• XST_FAILURE otherwise - if sending a LINK_ADDRESS sideband message to one of the branch devices in the topology failed.

Note:

The contents of the InstancePtr->Topology structure will be modified.

void XDptx_EnableMainLink

(

XDptx *

InstancePtr

)

This function enables the main link.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

None.

void XDptx_EnableTrainAdaptive	(	XDptx *	InstancePtr,
		u8	Enable
	)

This function enables or disables downshifting during the training process.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Enable	controls the downshift feature in the training process.

Returns:

None.

Note:

None.

u32 XDptx_EstablishLink

(

XDptx *

InstancePtr

)

This function checks if the link needs training and runs the training sequence if training is required.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS was either already trained, or has been trained successfully.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_FindAccessibleDpDevices	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress
	)

This function will explore the DisplayPort topology of downstream devices starting from the branch device specified by the LinkCountTotal and RelativeAddress parameters. It will recursively go through each branch device, obtain its information by sending a LINK_ADDRESS sideband message, and add this information to the the topology's node table. For each sink device connected to a branch's downstream port, this function will obtain the details of the sink, add it to the topology's node table, as well as add it to the topology's sink list.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the total DisplayPort links connecting the DisplayPort TX to the current downstream device in the recursion.
	RelativeAddress	is the relative address from the DisplayPort source to the current target DisplayPort device in the recursion.

Returns:

• XST_SUCCESS if the topology discovery is successful.
• XST_FAILURE otherwise - if sending a LINK_ADDRESS sideband message to one of the branch devices in the topology failed.

Note:

The contents of the InstancePtr->Topology structure will be modified.

u32 XDptx_GetDispIdDataBlock	(	u8 *	DisplayIdRaw,
		u8	SectionTag,
		u8 **	DataBlockPtr
	)

Given a section tag, search for and retrieve the appropriate section data block that is part of the specified DisplayID structure.

Parameters:

	DisplayIdRaw	is a pointer to the DisplayID data.
	SectionTag	is the tag to search for that represents the desired section data block.
	DataBlockPtr	will be set by this function to point to the appropriate section data block that is part of the DisplayIdRaw.

Returns:

• XST_SUCCESS if the section data block with the specified tag was found.
• XST_FAILURE otherwise.

Note:

The DataBlockPtr argument is modified to point to the entry in DisplayIdRaw that represents the beginning of the desired section data block.

u32 XDptx_GetEdid	(	XDptx *	InstancePtr,
		u8 *	Edid
	)

This function retrieves an immediately connected RX device's Extended Display Identification Data (EDID) structure.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Edid	is a pointer to the Edid buffer to save to.

Returns:

• XST_SUCCESS if the I2C transactions to read the EDID were successful.
• XST_ERROR_COUNT_MAX if the EDID read request timed out.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_GetEdidBlock	(	XDptx *	InstancePtr,
		u8 *	Data,
		u8	BlockNum
	)

Retrieve an immediately connected RX device's Extended Display Identification Data (EDID) block given the block number. A block number of 0 represents the base EDID and subsequent block numbers represent EDID extension blocks.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Data	is a pointer to the data buffer to save the block data to.
	BlockNum	is the EDID block number to retrieve.

Returns:

• XST_SUCCESS if the block read has successfully completed with no errors.
• XST_ERROR_COUNT_MAX if a time out occurred while attempting to read the requested block.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_GetGuid	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32 *	Guid
	)

This function will obtain the global unique identifier (GUID) for the target DisplayPort device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target device.
	RelativeAddress	is the relative address from the DisplayPort source to the target device.
	Guid	is a pointer to the GUID that will store the existing GUID of the target device.

Returns:

None.

Note:

None.

u32 XDptx_GetRemoteEdid	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8 *	Edid
	)

This function retrieves a remote RX device's Extended Display Identification Data (EDID) structure.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	Edid	is a pointer to the Edid buffer to save to.

Returns:

• XST_SUCCESS if the I2C transactions to read the EDID were successful.
• XST_ERROR_COUNT_MAX if the EDID read request timed out.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_GetRemoteEdidBlock	(	XDptx *	InstancePtr,
		u8 *	Data,
		u8	BlockNum,
		u8	LinkCountTotal,
		u8 *	RelativeAddress
	)

Retrieve a downstream DisplayPort device's Extended Display Identification Data (EDID) block given the block number. A block number of 0 represents the base EDID and subsequent block numbers represent EDID extension blocks.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Data	is a pointer to the data buffer to save the block data to.
	BlockNum	is the EDID block number to retrieve.
	LinkCountTotal	is the total DisplayPort links connecting the DisplayPort TX to the targeted downstream device.
	RelativeAddress	is the relative address from the DisplayPort source to the targeted DisplayPort device.

Returns:

• XST_SUCCESS if the block read has successfully completed with no errors.
• XST_ERROR_COUNT_MAX if a time out occurred while attempting to read the requested block.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_GetRemoteEdidDispIdExt	(	XDptx *	InstancePtr,
		u8 *	Data,
		u8	LinkCountTotal,
		u8 *	RelativeAddress
	)

Search for and retrieve a downstream DisplayPort device's Extended Display Identification Data (EDID) extension block of type DisplayID.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Data	is a pointer to the data buffer to save the DisplayID to.
	LinkCountTotal	is the total DisplayPort links connecting the DisplayPort TX to the targeted downstream device.
	RelativeAddress	is the relative address from the DisplayPort source to the targeted DisplayPort device.

Returns:

• XST_SUCCESS a DisplayID extension block was found.
• XST_ERROR_COUNT_MAX if a time out occurred while attempting to read an extension block.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE if no DisplayID extension block was found or some error occurred in the search.

Note:

None.

u32 XDptx_GetRemoteTiledDisplayDb	(	XDptx *	InstancePtr,
		u8 *	EdidExt,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8 **	DataBlockPtr
	)

Search for and retrieve a downstream DisplayPort device's Tiled Display Topology (TDT) section data block that is part of the downstream device's DisplayID structure. The DisplayID structure is part of the Extended Display Identification Data (EDID) in the form of an extension block.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	EdidExt	is a pointer to the data area that will be filled by the retrieved DisplayID extension block.
	LinkCountTotal	is the total DisplayPort links connecting the DisplayPort TX to the targeted downstream device.
	RelativeAddress	is the relative address from the DisplayPort source to the targeted DisplayPort device.
	DataBlockPtr	will be set by this function to point to the TDT data block that is part of the EdidExt extension block.

Returns:

• XST_SUCCESS a DisplayID extension block was found.
• XST_ERROR_COUNT_MAX if a time out occurred while attempting to read an extension block.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE if no DisplayID extension block was found or some error occurred in the search.

Note:

The EdidExt will be filled with the DisplayID EDID extension block and the DataBlockPtr argument is modified to point to the EdidExt entry representing the TDT section data block.

u32 XDptx_GetRxCapabilities

(

XDptx *

InstancePtr

)

This function retrieves the RX device's capabilities from the RX device's DisplayPort Configuration Data (DPCD).

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the DisplayPort Configuration Data was read successfully.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_HpdInterruptHandler

(

XDptx *

InstancePtr

)

This function is the interrupt handler for the XDptx driver.

When an interrupt happens, it first detects what kind of interrupt happened, then decides which callback function to invoke.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

None.

u32 XDptx_IicRead	(	XDptx *	InstancePtr,
		u8	IicAddress,
		u16	Offset,
		u16	BytesToRead,
		void *	ReadData
	)

This function performs an I2C read over the AUX channel. The read message will be divided into multiple transactions if the requested data spans multiple segments. The segment pointer is automatically incremented and the offset is calibrated as needed. E.g. For an overall offset of:

• 128, an I2C read is done on segptr=0; offset=128.
• 256, an I2C read is done on segptr=1; offset=0.
• 384, an I2C read is done on segptr=1; offset=128.
• 512, an I2C read is done on segptr=2; offset=0.
• etc.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	IicAddress	is the address on the I2C bus of the target device.
	Offset	is the offset at the specified address of the targeted I2C device that the read will start from.
	BytesToRead	is the number of bytes to read.
	ReadData	is a pointer to a buffer that will be filled with the I2C read data.

Returns:

• XST_SUCCESS if the I2C read has successfully completed with no errors.
• XST_ERROR_COUNT_MAX if the AUX request timed out.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_IicWrite	(	XDptx *	InstancePtr,
		u8	IicAddress,
		u8	BytesToWrite,
		void *	WriteData
	)

This function performs an I2C write over the AUX channel.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	IicAddress	is the address on the I2C bus of the target device.
	BytesToWrite	is the number of bytes to write.
	WriteData	is a pointer to a buffer which will be used as the data source for the write.

Returns:

• XST_SUCCESS if the I2C write has successfully completed with no errors.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if the AUX request timed out.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_InitializeTx

(

XDptx *

InstancePtr

)

This function prepares the DisplayPort TX core for use.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the DisplayPort TX core was successfully initialized.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_IsConnected

(

XDptx *

InstancePtr

)

This function checks if there is a connected RX device.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• TRUE if there is a connection.
• FALSE if there is no connection.

XDptx_Config* XDptx_LookupConfig

(

u16

DeviceId

)

This function looks for the device configuration based on the unique device ID. The table XDptx_ConfigTable[] contains the configuration information for each device in the system.

Parameters:

DeviceId

is the unique device ID of the device being looked up.

Returns:

A pointer to the configuration table entry corresponding to the given device ID, or NULL if no match is found.

Note:

None.

u32 XDptx_MstCapable

(

XDptx *

InstancePtr

)

This function will check if the immediate downstream RX device is capable of multi-stream transport (MST) mode. A DisplayPort Configuration Data (DPCD) version of 1.2 or higher is required and the MST capability bit in the DPCD must be set for this function to return XST_SUCCESS.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the RX device is MST capable.
• XST_NO_FEATURE if the RX device does not support MST.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if an AUX read request timed out.
  • XST_FAILURE otherwise - if an AUX read transaction failed.

Note:

None.

void XDptx_MstCfgModeDisable

(

XDptx *

InstancePtr

)

This function will disable multi-stream transport (MST) mode for the driver.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

When disabled, the driver will behave in single-stream transport (SST) mode.

void XDptx_MstCfgModeEnable

(

XDptx *

InstancePtr

)

This function will enable multi-stream transport (MST) mode for the driver.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

None.

void XDptx_MstCfgStreamDisable	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function will configure the InstancePtr->MstStreamConfig structure to disable the specified stream.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream ID that will be disabled.

Returns:

None.

Note:

None.

void XDptx_MstCfgStreamEnable	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function will configure the InstancePtr->MstStreamConfig structure to enable the specified stream.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream ID that will be enabled.

Returns:

None.

Note:

None.

u32 XDptx_MstDisable

(

XDptx *

InstancePtr

)

This function will disable multi-stream transport (MST) mode in both the DisplayPort TX and the immediate downstream RX device.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if MST mode has been successful disabled in hardware.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if the AUX write request timed out.
  • XST_FAILURE otherwise - if the AUX write transaction failed.

Note:

None.

u32 XDptx_MstEnable

(

XDptx *

InstancePtr

)

This function will enable multi-stream transport (MST) mode in both the DisplayPort TX and the immediate downstream RX device.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if MST mode has been successful enabled in hardware.
• XST_NO_FEATURE if the immediate downstream RX device does not support MST - that is, if its DisplayPort Configuration Data (DPCD) version is less than 1.2, or if the DPCD indicates that it has no DPCD capabilities.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed.

Note:

None.

u8 XDptx_MstStreamIsEnabled	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function will check whether

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream ID to check for enable/disable status.

Returns:

• 1 if the specified stream is enabled.
• 0 if the specified stream is disabled.

Note:

None.

u32 XDptx_RemoteDpcdRead	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32	DpcdAddress,
		u32	BytesToRead,
		u8 *	ReadData
	)

This function performs a remote DisplayPort Configuration Data (DPCD) read by sending a sideband message. In case message is directed at the RX device connected immediately to the TX, the message is issued over the AUX channel. The read message will be divided into multiple transactions which read a maximum of 16 bytes each.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	DpcdAddress	is the starting address to read from the RX device.
	BytesToRead	is the number of bytes to read.
	ReadData	is a pointer to the data buffer that will be filled with read data.

Returns:

• XST_SUCCESS if the DPCD read has successfully completed (has been acknowledged).
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
• XST_DATA_LOST if the requested number of BytesToRead does not equal that actually received.
• XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_RemoteDpcdWrite	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32	DpcdAddress,
		u32	BytesToWrite,
		u8 *	WriteData
	)

This function performs a remote DisplayPort Configuration Data (DPCD) write by sending a sideband message. In case message is directed at the RX device connected immediately to the TX, the message is issued over the AUX channel. The write message will be divided into multiple transactions which write a maximum of 16 bytes each.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	DpcdAddress	is the starting address to write to the RX device.
	BytesToWrite	is the number of bytes to write.
	WriteData	is a pointer to a buffer which will be used as the data source for the write.

Returns:

• XST_SUCCESS if the DPCD write has successfully completed (has been acknowledged).
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
• XST_DATA_LOST if the requested number of BytesToWrite does not equal that actually received.
• XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_RemoteIicRead	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8	IicAddress,
		u16	Offset,
		u16	BytesToRead,
		u8 *	ReadData
	)

This function performs a remote I2C read by sending a sideband message. In case message is directed at the RX device connected immediately to the TX, the message is sent over the AUX channel. The read message will be divided into multiple transactions which read a maximum of 16 bytes each. The segment pointer is automatically incremented and the offset is calibrated as needed. E.g. For an overall offset of:

• 128, an I2C read is done on segptr=0; offset=128.
• 256, an I2C read is done on segptr=1; offset=0.
• 384, an I2C read is done on segptr=1; offset=128.
• 512, an I2C read is done on segptr=2; offset=0.
• etc.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	IicAddress	is the address on the I2C bus of the target device.
	Offset	is the offset at the specified address of the targeted I2C device that the read will start from.
	BytesToRead	is the number of bytes to read.
	ReadData	is a pointer to a buffer that will be filled with the I2C read data.

Returns:

• XST_SUCCESS if the I2C read has successfully completed with no errors.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
• XST_DATA_LOST if the requested number of BytesToRead does not equal that actually received.
• XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_RemoteIicWrite	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8	IicAddress,
		u8	BytesToWrite,
		u8 *	WriteData
	)

This function performs a remote I2C write by sending a sideband message. In case message is directed at the RX device connected immediately to the TX, the message is sent over the AUX channel.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	IicAddress	is the address on the I2C bus of the target device.
	BytesToWrite	is the number of bytes to write.
	WriteData	is a pointer to a buffer which will be used as the data source for the write.

Returns:

• XST_SUCCESS if the I2C write has successfully completed with no errors.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
• XST_DATA_LOST if the requested number of BytesToWrite does not equal that actually received.
• XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

void XDptx_ResetPhy	(	XDptx *	InstancePtr,
		u32	Reset
	)

This function does a PHY reset.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Reset	is the type of reset to assert.

Returns:

None.

Note:

None.

u32 XDptx_SelfTest

(

XDptx *

InstancePtr

)

This function runs a self-test on the XDptx driver/device. The sanity test checks whether or not all tested registers hold their default reset values.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the self-test passed - all tested registers hold their default reset values.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_SendSbMsgAllocatePayload	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8	VcId,
		u16	Pbn
	)

This function will send an ALLOCATE_PAYLOAD sideband message which will allocate bandwidth for a virtual channel in the payload ID tables of the downstream devices connecting the DisplayPort TX to the target device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	VcId	is the unique virtual channel ID to allocate into the payload ID tables.
	Pbn	is the payload bandwidth number that determines how much bandwidth will be allocated for the virtual channel.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

ALLOCATE_PAYLOAD is a path message that will be serviced by all downstream DisplayPort devices connecting the DisplayPort TX and the target device.

u32 XDptx_SendSbMsgClearPayloadIdTable

(

XDptx *

InstancePtr

)

This function will send a CLEAR_PAYLOAD_ID_TABLE sideband message which will de-allocate all virtual channel payload ID tables.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

CLEAR_PAYLOAD_ID_TABLE is a broadcast message sent to all downstream devices.

u32 XDptx_SendSbMsgEnumPathResources	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u16 *	AvailPbn,
		u16 *	FullPbn
	)

This function will send an ENUM_PATH_RESOURCES sideband message which will determine the available payload bandwidth number (PBN) for a path to a target device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	AvailPbn	is a pointer to the available PBN of the path whose value will be filled in by this function.
	FullPbn	is a pointer to the total PBN of the path whose value will be filled in by this function.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

ENUM_PATH_RESOURCES is a path message that will be serviced by all downstream DisplayPort devices connecting the DisplayPort TX and the target device.

AvailPbn will be modified with the available PBN from the reply.

FullPbn will be modified with the total PBN of the path from the reply.

u32 XDptx_SendSbMsgLinkAddress	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		XDptx_SbMsgLinkAddressReplyDeviceInfo *	DeviceInfo
	)

This function will send a LINK_ADDRESS sideband message to a target DisplayPort branch device. It is used to determine the resources available for that device and some device information for each of the ports connected to the branch device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort branch device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort branch device.
	DeviceInfo	is a pointer to the device information structure whose contents will be filled in with the information obtained by the LINK_ADDRESS sideband message.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

The contents of the DeviceInfo structure will be modified with the information obtained from the LINK_ADDRESS sideband message reply.

u32 XDptx_SendSbMsgRemoteDpcdRead	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32	DpcdAddress,
		u32	BytesToRead,
		u8 *	ReadData
	)

This function will send a REMOTE_DPCD_READ sideband message which will read from the specified DisplayPort Configuration Data (DPCD) address of a downstream DisplayPort device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	DpcdAddress	is the DPCD address of the target device that data will be read from.
	BytesToRead	is the number of bytes to read from the specified DPCD address.
	ReadData	is a pointer to a buffer that will be filled with the DPCD read data.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_DATA_LOST if the requested number of BytesToRead does not equal that actually received.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_SendSbMsgRemoteDpcdWrite	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32	DpcdAddress,
		u32	BytesToWrite,
		u8 *	WriteData
	)

This function will send a REMOTE_DPCD_WRITE sideband message which will write some data to the specified DisplayPort Configuration Data (DPCD) address of a downstream DisplayPort device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	DpcdAddress	is the DPCD address of the target device that data will be written to.
	BytesToWrite	is the number of bytes to write to the specified DPCD address.
	WriteData	is a pointer to a buffer that stores the data to write to the DPCD location.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_SendSbMsgRemoteIicRead	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8	IicDeviceId,
		u8	Offset,
		u8	BytesToRead,
		u8 *	ReadData
	)

This function will send a REMOTE_I2C_READ sideband message which will read from the specified I2C address of a downstream DisplayPort device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target DisplayPort device.
	RelativeAddress	is the relative address from the DisplayPort source to the target DisplayPort device.
	IicDeviceId	is the address on the I2C bus of the target device.
	Offset	is the offset at the specified address of the targeted I2C device that the read will start from.
	BytesToRead	is the number of bytes to read from the I2C address.
	ReadData	is a pointer to a buffer that will be filled with the I2C read data.

Returns:

• XST_SUCCESS if the reply to the sideband message was successfully obtained and it indicates an acknowledge.

• XST_DEVICE_NOT_FOUND if no RX device is connected.
  • XST_ERROR_COUNT_MAX if either waiting for a reply, or an AUX request timed out.
  • XST_DATA_LOST if the requested number of BytesToRead does not equal that actually received.
  • XST_FAILURE otherwise - if an AUX read or write transaction failed, the header or body CRC of the sideband message did not match the calculated value, or the a reply was negative acknowledged (NACK'ed).

Note:

None.

u32 XDptx_SendSbMsgRemoteIicWrite	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u8	IicDeviceId,
		u8	BytesToWrite,
		u8 *	WriteData
	)

u32 XDptx_SetDownspread	(	XDptx *	InstancePtr,
		u8	Enable
	)

This function enables or disables 0.5% spreading of the clock for both the DisplayPort and the RX device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Enable	will downspread the main link signal if set to 1 and disable downspreading if set to 0.

Returns:

• XST_SUCCESS if setting the downspread control enable was successful.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_SetEnhancedFrameMode	(	XDptx *	InstancePtr,
		u8	Enable
	)

This function enables or disables the enhanced framing symbol sequence for both the DisplayPort TX core and the RX device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Enable	will enable enhanced frame mode if set to 1 and disable it if set to 0.

Returns:

• XST_SUCCESS if setting the enhanced frame mode enable was successful.
• XST_DEVICE_NOT_FOUND if no RX is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_SetHasRedriverInPath	(	XDptx *	InstancePtr,
		u8	Set
	)

This function sets a software switch that signifies whether or not a redriver exists on the DisplayPort output path. XDptx_SetVswingPreemp uses this switch to determine which set of voltage swing and pre-emphasis values to use in the TX core.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Set	establishes that a redriver exists in the DisplayPort output path.

Returns:

None.

Note:

None.

void XDptx_SetHpdEventHandler	(	XDptx *	InstancePtr,
		XDptx_HpdEventHandler	CallbackFunc,
		void *	CallbackRef
	)

This function installs a callback function for when a hot-plug-detect event interrupt occurs.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	CallbackFunc	is the address to the callback function.
	CallbackRef	is the user data item that will be passed to the callback function when it is invoked.

Returns:

None.

Note:

None.

void XDptx_SetHpdPulseHandler	(	XDptx *	InstancePtr,
		XDptx_HpdPulseHandler	CallbackFunc,
		void *	CallbackRef
	)

This function installs a callback function for when a hot-plug-detect pulse interrupt occurs.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	CallbackFunc	is the address to the callback function.
	CallbackRef	is the user data item that will be passed to the callback function when it is invoked.

Returns:

None.

Note:

None.

u32 XDptx_SetLaneCount	(	XDptx *	InstancePtr,
		u8	LaneCount
	)

This function sets the number of lanes to be used by the main link for both the DisplayPort TX core and the RX device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LaneCount	is the number of lanes to be used over the main link.

Returns:

• XST_SUCCESS if setting the new lane count was successful.
• XST_DEVICE_NOT_FOUND if no RX is connected.
• XST_FAILURE otherwise.

Note:

None.

u32 XDptx_SetLinkRate	(	XDptx *	InstancePtr,
		u8	LinkRate
	)

This function sets the data rate to be used by the main link for both the DisplayPort TX core and the RX device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkRate	is the link rate to be used over the main link based on one of the following selects: XDPTX_LINK_BW_SET_162GBPS = 0x06 (for a 1.62 Gbps data rate) XDPTX_LINK_BW_SET_270GBPS = 0x0A (for a 2.70 Gbps data rate) XDPTX_LINK_BW_SET_540GBPS = 0x14 (for a 5.40 Gbps data rate)

Returns:

• XST_SUCCESS if setting the new link rate was successful.
• XST_DEVICE_NOT_FOUND if no RX device is connected.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_SetMsaValues	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function sets the main stream attributes registers of the DisplayPort TX core with the values specified in the main stream attributes configuration structure.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number for which to set the MSA values for.

Returns:

None.

Note:

None.

u32 XDptx_SetScrambler	(	XDptx *	InstancePtr,
		u8	Enable
	)

This function enables or disables scrambling of symbols for both the DisplayPort and the RX device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Enable	will enable or disable scrambling.

Returns:

• XST_SUCCESS if setting the scrambling enable was successful.
• XST_FAILURE otherwise.

Note:

None.

void XDptx_SetStreamSelectFromSinkList	(	XDptx *	InstancePtr,
		u8	Stream,
		u8	SinkNum
	)

This function will map a stream to a downstream DisplayPort TX device that is associated with a sink from the InstancePtr->Topology.SinkList.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream ID that will be mapped to a DisplayPort device.
	SinkNum	is the sink ID in the sink list that will be mapped to the stream.

Returns:

None.

Note:

The contents of the InstancePtr->MstStreamConfig[Stream] will be modified.

The topology will need to be determined prior to calling this function using the XDptx_FindAccessibleDpDevices.

void XDptx_SetStreamSinkRad	(	XDptx *	InstancePtr,
		u8	Stream,
		u8	LinkCountTotal,
		u8 *	RelativeAddress
	)

This function will map a stream to a downstream DisplayPort TX device determined by the relative address.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Stream	is the stream number that will be mapped to a DisplayPort device.
	LinkCountTotal	is the total DisplayPort links connecting the DisplayPort TX to the targeted downstream device.
	RelativeAddress	is the relative address from the DisplayPort source to the targeted DisplayPort device.

Returns:

None.

Note:

The contents of the InstancePtr->MstStreamConfig[Stream] will be modified.

void XDptx_SetUserTimerHandler	(	XDptx *	InstancePtr,
		XDptx_TimerHandler	CallbackFunc,
		void *	CallbackRef
	)

This function installs a custom delay/sleep function to be used by the XDdptx driver.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	CallbackFunc	is the address to the callback function.
	CallbackRef	is the user data item (microseconds to delay) that will be passed to the custom sleep/delay function when it is invoked.

Returns:

None.

Note:

None.

void XDptx_SetVideoMode	(	XDptx *	InstancePtr,
		u8	Stream
	)

This function clears the main stream attributes registers of the DisplayPort TX core and sets them to the values specified in the main stream attributes configuration structure.

Parameters:

	InstancePtr	is a pointer to the XDptx instance
	Stream	is the stream number for which to set the MSA values for.

Returns:

None.

Note:

None.

void XDptx_TopologySortSinksByTiling

(

XDptx *

InstancePtr

)

Order the sink list with all sinks of the same tiled display being sorted by 'tile order'. Refer to the XDptx_GetDispIdTdtTileOrder macro on how to determine the 'tile order'. Sinks of a tiled display will have an index in the sink list that is lower than all indices of other sinks within that same tiled display that have a greater 'tile order'. When operations are done on the sink list, this ordering will ensure that sinks within the same tiled display will be acted upon in a consistent manner - with an incrementing sink list index, sinks with a lower 'tile order' will be acted upon first relative to the other sinks in the same tiled display. Multiple tiled displays may exist in the sink list.

Parameters:

InstancePtr

is a pointer to the XDptx instance.

Returns:

None.

Note:

None.

void XDptx_TopologySwapSinks	(	XDptx *	InstancePtr,
		u8	Index0,
		u8	Index1
	)

Swap the ordering of the sinks in the topology's sink list. All sink information is preserved in the node table - the swapping takes place only on the pointers to the sinks in the node table. The reason this swapping is done is so that functions that use the sink list will act on the sinks in a different order.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	Index0	is the sink list's index of one of the sink pointers to be swapped.
	Index1	is the sink list's index of the other sink pointer to be swapped.

Returns:

None.

Note:

None.

void XDptx_WaitUs	(	XDptx *	InstancePtr,
		u32	MicroSeconds
	)

This function is the delay/sleep function for the XDptx driver. For the Zynq family, there exists native sleep functionality. For MicroBlaze however, there does not exist such functionality. In the MicroBlaze case, the default method for delaying is to use a predetermined amount of loop iterations. This method is prone to inaccuracy and dependent on system configuration; for greater accuracy, the user may supply their own delay/sleep handler, pointed to by InstancePtr->UserTimerWaitUs, which may have better accuracy if a hardware timer is used.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	MicroSeconds	is the number of microseconds to delay/sleep for.

Returns:

None.

Note:

None.

void XDptx_WriteGuid	(	XDptx *	InstancePtr,
		u8	LinkCountTotal,
		u8 *	RelativeAddress,
		u32	Guid[4]
	)

This function will write a global unique identifier (GUID) to the target DisplayPort device.

Parameters:

	InstancePtr	is a pointer to the XDptx instance.
	LinkCountTotal	is the number of DisplayPort links from the DisplayPort source to the target device.
	RelativeAddress	is the relative address from the DisplayPort source to the target device.
	Guid	is a the GUID to write to the target device.

Returns:

None.

Note:

None.

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