cmx(4) Omnikey CardMan 4040 smartcard reader device driver


device cmx


The driver provides support for the PCCARD based Omnikey CardMan 4040 smartcard reader. The driver provides a character device special file based Chip/Smart Card Interface Devices (CCID) interface. The driver implements what the vendor calls the Synchronous API onto the smartcard reader device.

Reading and writing is synchronous, meaning that a call to write(2) directly corresponds to a complete CCID command sent to the device, while the following read(2) will return the complete answer from the reader. There is no support for partial reads or writes. There is no upper limit on CCID request or response sizes, but the complete CCID request must be sent to the driver in write(2) and the complete CCID response must fit into the buffer supplied to read(2).

Non-blocking I/O, select(2) and poll(2) are supported and work as expected. An open file descriptor will always be ready for writing, but only ready for reading if the device indicates that it has data available.


Character device special file.
OpenCT, a userspace smartcard daemon containing a CCID driver which directly supports devices.


Userland smartcard code written for the vendor's Linux drivers should work with the driver without modification.


The cmx driver first appeared in Fx 7.1 .


An -nosplit The driver was written by An Daniel Roethlisberger Aq [email protected] , originally based on the Linux driver v1.1.0 by An Omnikey GmbH Aq . Early testing and bug fixes by An Marcin Cieslak Aq [email protected] .


An -nosplit The way the driver talks to the CardMan 4040 is a bit rough. Due to the complete lack of hardware documentation other than vendor drivers for other operating systems, the gory details of the device's I/O registers are not understood very well. There may be error conditions which can only be solved by physically reinserting the reader.