The Serial Device Bus
UARTs and RS-232 have been around since the 1960s, and despite the advent of technologies like USB and PCIe, it seems UART-attached devices aren't going away anytime soon. In embedded systems, UARTs are a commonly used peripheral interface (e.g. for Bluetooth, NFC, and GPS) even if the kernel infrastructure for dealing with such devices has been both limited in what it can provide (e.g. in terms of power management) and cumbersome to use (e.g. requiring user-space daemons).
This presentation will give an introduction to the new Serial Device Bus, which aims to overcome some of these limitations by making UART-attached devices fit better into the Linux device model. After providing some historical background, the design and interfaces of the new bus will be reviewed, and some known limitations and possibilities for future enhancements will be discussed.
Hovold Consulting AB
Johan Hovold has been working with embedded Linux since 2002, and for the last ten years as a consultant. He recently spent two years on Google's Project Ara as kernel developer and tech
lead for Greybus core. Johan is the maintainer of the kernel's USB Serial and Greybus subsystems.