---
title: FindPCICapability
framework: pcidriverkit
role: symbol
role_heading: Instance Method
path: pcidriverkit/iopcidevice/findpcicapability
---

# FindPCICapability

Search the configuration space for a PCI capability register.

## Declaration

```occ
virtual kern_return_t FindPCICapability(uint32_t capabilityID, uint64_t searchOffset, uint64_t *foundCapabilityOffset);
```

## Parameters

- `capabilityID`: A PCI capability ID. PCI Express devices may support extended capabilities in configuraiton space, starting at offset 0x100. To search this space, pass an ID that is the negated value of the PCI-SIG assigned ID for the extended capability.
- `searchOffset`: The offset into configuration space at which to start the search.
- `foundCapabilityOffset`: A variable in which you want to store the resulting offset value.

## Return Value

Return Value kIOReturnSuccess on success, or another value if an error occurs. See Error Codes.

## See Also

### Getting Device Information

- [GetBusDeviceFunction](pcidriverkit/iopcidevice/getbusdevicefunction.md)
- [PCI Capabilities](pcidriverkit/pci-capabilities-enum.md)
- [Slot Capabilities](pcidriverkit/slot-capabilities-enum.md)