---
title: IOI2CInterfaceOpen
framework: IOKit
role: symbol
role_heading: Function
platforms: [Mac Catalyst 13.0+, macOS 10.3+]
path: iokit/1410388-ioi2cinterfaceopen
---

# IOI2CInterfaceOpen

Opens an instance of an I2C bus interface, allowing I2C requests to be made.

## Declaration

```occ
IOReturn IOI2CInterfaceOpen(io_service_t interface, IOOptionBits options, IOI2CConnectRef *connect);
```

## Parameters

- `interface`: An I2C bus interface (see IOFBCopyI2CInterfaceForBus). The interface may be released after this call is made.
- `options`: Pass kNilOptions.
- `connect`: The opaque IOI2CConnectRef is returned, for use with IOI2CSendRequest() and IOI2CInterfaceClose().

## Return Value

Return Value An IOReturn code.

## Discussion

Discussion An instance of an I2C bus interface, obtained by IOFBCopyI2CInterfaceForBus, is opened with this function allowing I2C requests to be made.

## See Also

### Miscellaneous

- [IOFBCopyI2CInterfaceForBus](iokit/1410345-iofbcopyi2cinterfaceforbus.md)
- [IOFBGetI2CInterfaceCount](iokit/1410333-iofbgeti2cinterfacecount.md)
- [IOI2CInterfaceClose](iokit/1410390-ioi2cinterfaceclose.md)
- [IOI2CSendRequest](iokit/1410373-ioi2csendrequest.md)