Initializes a token-ring device handler and allocates the required system resources.
|devno||Specifies major and minor device numbers.|
|devflag|| Specifies the flag word with the following definitions:
|chan||Specifies the channel number assigned by the tokmpx entry point.|
|arg||Points to a kopen_ext structure for kernel-mode processes. For user-mode processes, this field is not used.|
The tokopen entry point is called when a user-mode caller issues an open, openx, or creat subroutine. The tokopen routine can also be invoked in response to an fp_opendev kernel service. The device is opened to read and write data.
Note: After the tokopen operation has successfully completed, the caller must then issue a CIO_START operation before any data can be transmitted or received from a token-ring device handler.
The tokopen entry point can be called from the process environment only.
|ENXIO||Indicates the specified minor number is not valid.|
|EINVAL||Indicates a specified parameter is not valid.|
|ENOMEM||Indicates the device handler was unable to allocate the required memory.|
The tokopen entry point functions with a Token-Ring High Performance Network Adapter that has been correctly configured for use on a qualified network. Consult adapter specifications for more information on configuring the adapter and network qualifications.
The CIO_START tokioctl Token-Ring Device Handler Operation.
The open, openx or creat subroutine.
The ddopen Communications PDH entry point.
The fp_opendev kernel service.