VideoPortGetBusData function (video.h)

Article
10/21/2021

The VideoPortGetBusData function returns bus-type-specific configuration information.

Syntax

VIDEOPORT_DEPRECATED VIDEOPORT_API ULONG VideoPortGetBusData(
        PVOID         HwDeviceExtension,
        BUS_DATA_TYPE BusDataType,
        ULONG         SlotNumber,
  [out] PVOID         Buffer,
        ULONG         Offset,
        ULONG         Length
);

Parameters

HwDeviceExtension

Pointer to the miniport driver's device extension.

BusDataType

Specifies the type of bus configuration data to return. The value of this parameter can be Cmos, EisaConfiguration, or PCIConfiguration. However, additional types of bus configuration might be supported in the future. The upper bound on the types supported is always MaximumBusDataType.

SlotNumber

Specifies the location of the device on the bus for a Cmos BusDataType; zero for all other bus types.

[out] Buffer

Pointer to a buffer into which VideoPortGetBusData returns the configuration information. The contents of the buffer depend on the BusDataType, as follows:

If Cmos is specified, the buffer contains the contents of the CMOS (bus number equals zero) or ECMOS (bus number equals one) locations, starting with the location specified for SlotNumber. A miniport driver's HwVidFindAdapter function can determine the number of the bus from the SystemIoBusNumber member of the VIDEO_PORT_CONFIG_INFO input structure.
If EisaConfiguration is specified, the buffer contains the CM_EISA_SLOT_INFORMATION structure, followed by zero or more CM_EISA_FUNCTION_INFORMATION structures for the specified slot.
If PCIConfiguration is specified, the buffer contains the PCI_COMMON_CONFIG information for the specified slot.

Offset

Specifies the offset, in bytes, into the PCI configuration space that should be retrieved If BusDataType is PCIConfiguration; otherwise zero. See Remarks for more information.

Length

Specifies the length, in bytes, of Buffer.

Return value

VideoPortGetBusData returns the number of bytes of configuration information it has written in Buffer. If the given BusDataType is not valid for the current platform, this function generally returns zero.

Return code	Description
0	The PCI bus does not exist.
2	The PCI bus exists, but Buffer contains the value PCI_INVALID_VENDOR_ID at the PCI_COMMON_CONFIG VendorId member.

Remarks

To obtain only a part of the configuration information, the miniport driver should set Offset to the byte offset of the information needed, and set Length to the number of bytes of the information needed. For example, if only the command register is needed, set Offset to the offset of this register, and set Length to sizeof(USHORT).

The driver should call VideoPortGetAccessRanges rather than VideoPortGetBusData to retrieve its hardware resources.

Requirements

Requirement	Value
Minimum supported client	Available in Windows 2000 and later versions of the Windows operating systems.
Target Platform	Desktop
Header	video.h (include Video.h)
Library	Videoprt.lib
DLL	Videoprt.sys
IRQL	PASSIVE_LEVEL