class Control

Callback for handling EP0 class/vendor-specific control requests targeting the interface(s)

owned by this function.

This is called when the host sends a control request to the device. The protocol server (of

[`UsbFunctionInterface`]) should process the request and return the result.

The host expects a response within a strict timeout period defined by the USB specification

Section 9.2.6 (50ms for requests without data, and 500ms for read data stages). Because of

these hardware-enforced limits, the implementation must reply as quickly as possible and

avoid blocking the dispatcher.

`setup` is the control request metadata (setup packet). `write` contains the raw bytes sent

by the host in the Data Stage of a host-to-device (OUT) control transfer. It is empty for

device-to-host (IN) transfers. `read` in the response payload contains the raw bytes

returned to the host in the Data Stage of a device-to-host (IN) control transfer. It must

be empty for host-to-device (OUT) transfers.

Any error returned by this method (including `ZX_ERR_NOT_SUPPORTED`) causes the

peripheral controller to stall Endpoint 0, signaling a "Request Error" to the host.

* error:

* `ZX_ERR_NOT_SUPPORTED` if the request is not supported by the protocol server.

* `ZX_ERR_INVALID_ARGS` if the setup packet or data is invalid.

* `ZX_ERR_IO_NOT_PRESENT` if the device was disconnected while processing the request.