Free And Open Source Software At CERN: Integration Of Drivers In The Linux Kernel

Most device drivers written for accelerator control systems suffer from severe lack of portability due to the ad hoc nature of the code, often embodied with intimate knowledge of the particular machine it is deployed in. In this paper we challenge this practice by arguing for the opposite approach: development in the open, which in our case translates into the integration of our code within the Linux kernel. We make our case by describing the upstream merge effort of the tsi148 driver, a critical (and complex) component of the control system. The encouraging results from this effort have then led us to follow the same approach with two more ambitious projects, currently in the works: Linux support for the upcoming FMC boards [1, 2] and a new I/O subsystem.