DXGKDDI_I2C_TRANSMIT_DATA_TO_DISPLAY callback function (dispmprt.h)

Article
06/02/2022

The DXGKDDI_I2C_TRANSMIT_DATA_TO_DISPLAY callback function transmits data to an I2C device in a monitor.

Syntax

DXGKDDI_I2C_TRANSMIT_DATA_TO_DISPLAY DxgkddiI2cTransmitDataToDisplay;

NTSTATUS DxgkddiI2cTransmitDataToDisplay(
  [in] PVOID MiniportDeviceContext,
  [in] D3DDDI_VIDEO_PRESENT_TARGET_ID VidPnTargetId,
  [in] ULONG SevenBitI2CAddress,
  [in] ULONG DataLength,
  [in] const VOID *Data
)
{...}

Parameters

[in] MiniportDeviceContext

A handle to a context block that is associated with a display adapter. The display miniport driver's DxgkDdiAddDevice function previously provided this handle to the Microsoft DirectX graphics kernel subsystem.

[in] VidPnTargetId

An integer that identifies one of the video present targets on the display adapter.

[in] SevenBitI2CAddress

The address of the I2C device to which data will be transmitted.

[in] DataLength

The length, in bytes, of the data to be transmitted. This parameter must be between 1 and 64, inclusive.

[in] Data

A pointer to a buffer that holds the data to be transmitted.

Return value

DXGKDDI_I2C_TRANSMIT_DATA_TO_DISPLAY returns STATUS_SUCCESS if it succeeds. Otherwise, it returns one of the error codes defined in Ntstatus.h. The following list gives some of the possible error codes that can be returned.

Return code	Description
STATUS_GRAPHICS_MONITOR_NOT_CONNECTED	There is no monitor connected to the video output identified by VidPnTargetId.
STATUS_GRAPHICS_I2C_NOT_SUPPORTED	The video output identified by VidPnTargetId does not have an I2C bus.
STATUS_GRAPHICS_I2C_DEVICE_DOES_NOT_EXIST	No device acknowledged the I2C address supplied in SevenBitI2CAddress. This could mean that no device on the I2C bus has the specified address or that an error occurred when the address was transmitted.
STATUS_GRAPHICS_I2C_ERROR_TRANSMITTING_DATA	The I2C address was successfully transmitted, but there was an error transmitting data to the I2C device.

Remarks

The video present target identified by VidPnTargetId is associated with one of the video outputs on the display adapter. The data is transmitted to an I2C device in the monitor that is connected to that video output.

DxgkDdiI2CTransmitDataToDisplay is responsible for signaling the I2C start condition, sending the I2C address, sending the data in the buffer, checking for acknowledgments from the receiver, and signaling the stop condition. For details about the I2C bus, see the I2C Bus Specification, published by Philips Semiconductors. The specification defines a protocol for initiating I2C communication, reading and writing bytes over the I2C data line, and terminating I2C communication.

DxgkDdiI2CTransmitDataToDisplay is required to transmit data to an I2C device that has address 0x6E but is permitted to refuse to transmit data to any I2C device that has a different address.

DxgkDdiI2CTransmitDataToDisplay is permitted to block if another part of the display miniport driver or graphics hardware is using the specified monitor's I2C bus. It is also permitted to block if the display miniport driver is using the I2C bus to send or receive High-bandwidth Digital Content Protection (HDCP) data.

If the display adapter supports HDCP, the DxgkDdiI2CTransmitDataToDisplay function must refuse to send data to an I2C device if the device has an I2C address that is used by HDCP.

DxgkDdiI2CTransmitDataToDisplay must never transmit data to an I2C device on the display adapter. That is, this function can transmit data to an I2C device in a monitor that is connected to the display adapter, but not to an I2C device that is on the display adapter itself.

DxgkDdiI2CTransmitDataToDisplay should be made pageable.

Requirements

Requirement	Value
Minimum supported client	Windows Vista
Target Platform	Desktop
Header	dispmprt.h (include Dispmprt.h)
IRQL	PASSIVE_LEVEL