Performance problems

Just over a year ago I implemented an optimization to the SPI core code in Linux that avoids some needless context switches to a worker thread in the main data path that most clients use. This was really nice, it was simple to do but saved a bunch of work for most drivers using SPI and made things […]

regmap – a register map abstraction for the Linux kernel

A good proportion of I2C and SPI device drivers in the kernel contain some very similar code for accessing the register maps of hardware connected to those buses – most hardware designers have solved the problem of providing very similar ways. Linux 3.1 introduces a new kernel API called regmap which factors out this code […]