Provides access to multiprotocol adapters by way of the Multiprotocol Quad Port (MPQP) device handler.
The /dev/mpqn character special file provides access to the MPQP device handler for the purpose of providing access to a synchronous network. The MPQP device handler supports multiple adapters.
When accessing the MPQP device handler, the following should be taken into account:
The device handler may be loaded and unloaded. The handler supports the configuration calls to initialize and terminate itself.
Calls other than the open and close subroutine calls are discussed in relation to the mode in which the device handler is operating.
The MPQP device handler supports the open, close, read, write, and ioctl subroutines in the following manner:
The device handler supports the /dev/mpqn special file as a character-multiplex special file. The special file must be opened for both reading and writing (O_RDWR). There are no particular considerations for closing the special file. Which special file name is used in an open call depends on how the device is to be opened. Types of special file names are:
/dev/mpqn | Starts the device handler for the selected port. |
/dev/mpqn/D | Starts the device handler in Diagnostic mode for the selected port. |
Can take the form of a read, readx, readv, or readvx subroutine call. For this call, the device handler copies the data into the buffer specified by the caller.
Can take the form of a write, writex, writev, or writevx subroutine call. For this call, the device handler copies the user data into a buffer and transmits the data on the LAN.
CIO_START | Starts a session and registers a network ID. |
CIO_HALT | Halts a session and removes a network ID. |
CIO_QUERY | Returns the current RAS counter values. These values are defined in the /usr/include/sys/comio.h file. |
CIO_GET_STAT | Returns the current adapter and device handler status. |
MP_START_AR | Puts the MPQP port into Autoresponse mode. |
MP_STOP_AR | Permits the MPQP port to exit Autoresponse mode. |
MP_CHG_PARMS | Permits the data link control (DLC) to change certain profile parameters after the MPQP device has been started. |
MP_SET_DELAY | Sets the value of NDELAY. |
The following error codes may be returned when accessing the device handler through the /dev/mpqn special file:
The communication device handler chapter defines specific errors returned on each subroutine call.
The close subroutine, open subroutine, read or readx subroutine, write or writex subroutine, ioctl subroutine.
MPQP Device Handler Interface Overview in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.