Xilinx Processor IP Library

Software Drivers

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xdp.c File Reference

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Detailed Description

Contains a minimal set of functions for the XDp driver that allow access to all of the DisplayPort core's functionality. See xdp.h for a detailed description of the driver.

Note:

None.

 MODIFICATION HISTORY:

 Ver   Who  Date     Changes
 ----- ---- -------- -----------------------------------------------
 1.0   als  01/20/15 Initial release.
 

#include "xdp.h"
#include "xenv.h"

Classes
struct	XDp_AuxTransaction
Defines
#define	XDP_TX_MAXIMUM_VS_LEVEL   3
#define	XDP_TX_MAXIMUM_PE_LEVEL   3
#define	XDP_AUX_MAX_DEFER_COUNT   50
#define	XDP_AUX_MAX_TIMEOUT_COUNT   50
#define	XDP_IS_CONNECTED_MAX_TIMEOUT_COUNT   50
Enumerations
enum	XDp_TxTrainingState {   XDP_TX_TS_CLOCK_RECOVERY, XDP_TX_TS_CHANNEL_EQUALIZATION, XDP_TX_TS_ADJUST_LINK_RATE, XDP_TX_TS_ADJUST_LANE_COUNT,   XDP_TX_TS_FAILURE, XDP_TX_TS_SUCCESS }
Functions
void	XDp_CfgInitialize (XDp *InstancePtr, XDp_Config *ConfigPtr, u32 EffectiveAddr)
u32	XDp_Initialize (XDp *InstancePtr)
u32	XDp_TxGetRxCapabilities (XDp *InstancePtr)
u32	XDp_TxCfgMainLinkMax (XDp *InstancePtr)
u32	XDp_TxEstablishLink (XDp *InstancePtr)
u32	XDp_TxCheckLinkStatus (XDp *InstancePtr, u8 LaneCount)
void	XDp_TxEnableTrainAdaptive (XDp *InstancePtr, u8 Enable)
void	XDp_TxSetHasRedriverInPath (XDp *InstancePtr, u8 Set)
void	XDp_TxCfgTxVsOffset (XDp *InstancePtr, u8 Offset)
void	XDp_TxCfgTxVsLevel (XDp *InstancePtr, u8 Level, u8 TxLevel)
void	XDp_TxCfgTxPeLevel (XDp *InstancePtr, u8 Level, u8 TxLevel)
u32	XDp_TxIsConnected (XDp *InstancePtr)
u32	XDp_TxAuxRead (XDp *InstancePtr, u32 DpcdAddress, u32 BytesToRead, void *ReadData)
u32	XDp_TxAuxWrite (XDp *InstancePtr, u32 DpcdAddress, u32 BytesToWrite, void *WriteData)
u32	XDp_TxIicRead (XDp *InstancePtr, u8 IicAddress, u16 Offset, u16 BytesToRead, void *ReadData)
u32	XDp_TxIicWrite (XDp *InstancePtr, u8 IicAddress, u8 BytesToWrite, void *WriteData)
u32	XDp_TxSetDownspread (XDp *InstancePtr, u8 Enable)
u32	XDp_TxSetEnhancedFrameMode (XDp *InstancePtr, u8 Enable)
u32	XDp_TxSetLaneCount (XDp *InstancePtr, u8 LaneCount)
u32	XDp_TxSetLinkRate (XDp *InstancePtr, u8 LinkRate)
u32	XDp_TxSetScrambler (XDp *InstancePtr, u8 Enable)
void	XDp_TxEnableMainLink (XDp *InstancePtr)
void	XDp_TxDisableMainLink (XDp *InstancePtr)
void	XDp_TxResetPhy (XDp *InstancePtr, u32 Reset)
u32	XDp_RxCheckLinkStatus (XDp *InstancePtr)
void	XDp_RxDtgEn (XDp *InstancePtr)
void	XDp_RxDtgDis (XDp *InstancePtr)
void	XDp_RxSetLinkRate (XDp *InstancePtr, u8 LinkRate)
void	XDp_RxSetLaneCount (XDp *InstancePtr, u8 LaneCount)
void	XDp_SetUserTimerHandler (XDp *InstancePtr, XDp_TimerHandler CallbackFunc, void *CallbackRef)
void	XDp_WaitUs (XDp *InstancePtr, u32 MicroSeconds)

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Define Documentation

#define XDP_AUX_MAX_DEFER_COUNT   50

#define XDP_AUX_MAX_TIMEOUT_COUNT   50

#define XDP_IS_CONNECTED_MAX_TIMEOUT_COUNT   50

#define XDP_TX_MAXIMUM_PE_LEVEL   3

#define XDP_TX_MAXIMUM_VS_LEVEL   3

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Enumeration Type Documentation

enum XDp_TxTrainingState

This typedef enumerates the list of training states used in the state machine during the link training process.

Enumerator:

XDP_TX_TS_CLOCK_RECOVERY
XDP_TX_TS_CHANNEL_EQUALIZATION
XDP_TX_TS_ADJUST_LINK_RATE
XDP_TX_TS_ADJUST_LANE_COUNT
XDP_TX_TS_FAILURE
XDP_TX_TS_SUCCESS

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Function Documentation

void XDp_CfgInitialize	(	XDp *	InstancePtr,
		XDp_Config *	ConfigPtr,
		u32	EffectiveAddr
	)

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

Parameters:

	InstancePtr	is a pointer to the XDp 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 XDp_Initialize

(

XDp *

InstancePtr

)

This function prepares the DisplayPort core for use depending on whether the core is operating in TX or RX mode.

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

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

Note:

None.

u32 XDp_RxCheckLinkStatus

(

XDp *

InstancePtr

)

This function checks if the reciever's internal registers indicate that link training has complete. That is, training has achieved channel equalization, symbol lock, and interlane alignment for all lanes currently in use.

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

• XST_SUCCESS if the RX device has achieved clock recovery, channel equalization, symbol lock, and interlane alignment.
• XST_FAILURE otherwise.

Note:

None.

void XDp_RxDtgDis

(

XDp *

InstancePtr

)

This function disables the display timing generator (DTG).

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

None.

Note:

None.

void XDp_RxDtgEn

(

XDp *

InstancePtr

)

This function enables the display timing generator (DTG).

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

None.

Note:

None.

void XDp_RxSetLaneCount	(	XDp *	InstancePtr,
		u8	LaneCount
	)

This function sets the maximum lane count to be exposed in the RX device's DisplayPort Configuration Data (DPCD) registers.

Parameters:

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

Returns:

None.

Note:

None.

void XDp_RxSetLinkRate	(	XDp *	InstancePtr,
		u8	LinkRate
	)

This function sets the maximum data rate to be exposed in the RX device's DisplayPort Configuration Data (DPCD) registers.

Parameters:

	InstancePtr	is a pointer to the XDp instance.
	LinkRate	is the link rate to be used over the main link based on one of the following selects: XDP_RX_LINK_BW_SET_162GBPS = 0x06 (for a 1.62 Gbps data rate) XDP_RX_LINK_BW_SET_270GBPS = 0x0A (for a 2.70 Gbps data rate) XDP_RX_LINK_BW_SET_540GBPS = 0x14 (for a 5.40 Gbps data rate)

Returns:

None.

Note:

None.

void XDp_SetUserTimerHandler	(	XDp *	InstancePtr,
		XDp_TimerHandler	CallbackFunc,
		void *	CallbackRef
	)

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

Parameters:

	InstancePtr	is a pointer to the XDp 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.

u32 XDp_TxAuxRead	(	XDp *	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 XDp 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 XDp_TxAuxWrite	(	XDp *	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 XDp 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.

u32 XDp_TxCfgMainLinkMax

(

XDp *

InstancePtr

)

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

Parameters:

InstancePtr

is a pointer to the XDp 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 XDp_TxCfgTxPeLevel	(	XDp *	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 XDp 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 XDp_TxCfgTxVsLevel	(	XDp *	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 XDp 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 XDp_TxCfgTxVsOffset	(	XDp *	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 XDp instance.
	Offset	is the value to set for the voltage swing offset.

Returns:

None.

Note:

None.

u32 XDp_TxCheckLinkStatus	(	XDp *	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 XDp 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 XDp_TxDisableMainLink

(

XDp *

InstancePtr

)

This function disables the main link.

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

None.

Note:

None.

void XDp_TxEnableMainLink

(

XDp *

InstancePtr

)

This function enables the main link.

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

None.

Note:

None.

void XDp_TxEnableTrainAdaptive	(	XDp *	InstancePtr,
		u8	Enable
	)

This function enables or disables downshifting during the training process.

Parameters:

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

Returns:

None.

Note:

None.

u32 XDp_TxEstablishLink

(

XDp *

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 XDp 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 XDp_TxGetRxCapabilities

(

XDp *

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 XDp 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.

u32 XDp_TxIicRead	(	XDp *	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 XDp 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 XDp_TxIicWrite	(	XDp *	InstancePtr,
		u8	IicAddress,
		u8	BytesToWrite,
		void *	WriteData
	)

This function performs an I2C write over the AUX channel.

Parameters:

	InstancePtr	is a pointer to the XDp 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 XDp_TxIsConnected

(

XDp *

InstancePtr

)

This function checks if there is a connected RX device.

Parameters:

InstancePtr

is a pointer to the XDp instance.

Returns:

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

void XDp_TxResetPhy	(	XDp *	InstancePtr,
		u32	Reset
	)

This function does a PHY reset.

Parameters:

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

Returns:

None.

Note:

None.

u32 XDp_TxSetDownspread	(	XDp *	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 XDp 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 XDp_TxSetEnhancedFrameMode	(	XDp *	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 XDp 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 XDp_TxSetHasRedriverInPath	(	XDp *	InstancePtr,
		u8	Set
	)

This function sets a software switch that signifies whether or not a redriver exists on the DisplayPort output path. XDp_TxSetVswingPreemp 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 XDp instance.
	Set	establishes that a redriver exists in the DisplayPort output path.

Returns:

None.

Note:

None.

u32 XDp_TxSetLaneCount	(	XDp *	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 XDp 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 XDp_TxSetLinkRate	(	XDp *	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 XDp instance.
	LinkRate	is the link rate to be used over the main link based on one of the following selects: XDP_TX_LINK_BW_SET_162GBPS = 0x06 (for a 1.62 Gbps data rate) XDP_TX_LINK_BW_SET_270GBPS = 0x0A (for a 2.70 Gbps data rate) XDP_TX_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.

u32 XDp_TxSetScrambler	(	XDp *	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 XDp instance.
	Enable	will enable or disable scrambling.

Returns:

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

Note:

None.

void XDp_WaitUs	(	XDp *	InstancePtr,
		u32	MicroSeconds
	)

This function is the delay/sleep function for the XDp 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 XDp instance.
	MicroSeconds	is the number of microseconds to delay/sleep for.

Returns:

None.

Note:

None.

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