Hi,

this is just an update for those who use the older Wolfson Audio Card. You can download it here or simply fire up your Raspberry Pi and install it directly. The kernel sources are from Cirrus Logic’s 3.12.33 kernel. This kernel is patched with the realtime preemption patches from https://www.kernel.org/pub/linux/kernel/projects/rt/ So now you should have a realtime linux system running on your Raspberry Pi for making LIVE MUSIC or other things.

THIS WON’T WORK FOR THE NEW RASPBERRY PI 2!

The kernel is running on a standard Raspberry Pi Debian Wheezy image  2015-02-16 which you can download from http://www.raspberrypi.org/downloads/

On Raspberry Pi, open a shell and type

wget https://blog.georgmill.de/wp-content/uploads/2015/02/linux-image-3.12.33-rt47-georg_3.12.33-rt47-georg-1_armhf.deb

Then install it with

dpkg -i linux-image-3.12.33-rt47-georg_3.12.33-rt47-georg-1_armhf.deb

sudo mv /boot/vmlinuz-3.12.33-rt47-georg /boot/kernel-rt-georg.img

Thanks for Ragnar Jensen’s patch for memory mapped I/O support to the Wolfson/Cirrus card.

A slightly modified version of this patch can be found here.

Change boot options in /boot/config.txt with

sudo nano /boot/config.txt

and change OR add this line:

kernel=kernel-rt-georg.img

Open  /etc/modules  with

sudo nano /etc/modules

and change OR add these lines:

spi-bcm2708
i2c-bcm2708
arizona-spi
snd-soc-wm5102
snd-soc-pcm5102a
snd-soc-wm8804
snd-soc-rpi-wsp
snd-soc-rpi-wsp

bcm2708-rng
snd-bcm2835
gpio_arizona
arizona_micsupp
snd_soc_bcm2708_i2s
snd-soc-arizona
snd-soc-wm-adsp
snd-soc-wm5102
snd-soc-rpi-wsp

Open /etc/modprobe.d/raspi-blacklist.conf with