<!--
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  "documentType" : "symbol",
  "framework" : "PCIDriverKit",
  "identifier" : "/documentation/PCIDriverKit/IOPCIDevice/FindPCICapability",
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  "role" : "Instance Method",
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  "title" : "FindPCICapability"
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# FindPCICapability

Search the configuration space for a PCI capability register.

```
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

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. See <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

---

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