Hello, I am building a midi synthesizer that I'd like to be able to control from linux. I know its a rather broad question, but, how do I go about this? At this point the hardware consists of a simple UART bridge, and I've already written a simple C++ program using termios to send the raw midi data to the device. Obviously I don't want to write a player/sequencer from scratch, so where should I start if I wanted to get this thing to work with, say, a sequencer like rosegarden? Do I write the driver for rosegarden, or hook into alsa or what?

Write for ALSA, then any app that uses ALSA (like rosegarden) can use it. It sounds like you would be most interested in ALSA's MIDI UART interface.

http://www.kernel.org/pub/linux/kern...iver/ch08.html