The git repository (git.digispeaker.com) contains working drivers for USB, SD card, the Maxim clock chip, mpc5200 i2s driver, and an ALSA driver for the tas5504. I have a driver for the RTC located on the mpc5200 but I don't have anyway to test it currently. As I (and others) get these drivers in a finished state I'm going through the arduous process of contributing the changes back to the mainstream Linux kernel. It takes anywhere from a week to six months effort to get the various drivers accepted.

The ALSA driver works with normal ALSA players. It also exposes about 200 hardware specific IOCTLs for controlling every aspect of the TAS5504. We'll need to write a user space app to setup the TAS to exactly match the connected speakers. The TAS supports the complex signal processing needed to bi/tri-amp. Part of the setup is programming the digital filters to support the correct speaker configuration.

This morning I figured out how to program the flash on the Phytec mpc5200 development card using a $50 ARM JTAG. I did this by modifying UrJtag. This a significant advancement since flash programmers for the PowerPC cost $1000-4000. With these changes a hobbyist can unbrick a Digispeaker for $50.

I used this ARM JTAG but this one should also work. The Phytec card's flash is on a multiplexed bus making it harder to program via JTAG. The Digispeaker boot flash is not multiplexed so it is much easier to deal with. I'll contribute my changes back to the UrJtag project in a few days.

Next up is some more testing with the flash programmer. After that I'll solder together an IR receiver using Radio Shack parts and write a driver for it.