I just bought a new copy of the Cirrus Logic Audio Card. I'm still waiting on delivery of the quadcore Pi 2, so my fallback option is to start off using it on my B+.
Rather than downloading and installing the Cirrus Audio linux os image, I'd prefer to keep my existing deployed linux installation and build a new kernel/driver to add support for the card on my existing system. To do this I'm following CirrusLogic's official "Build the Code" instructions on github:
Unfortunately, the "Build the Code" instructions contain unresolved errors that prevent the user from completing a successful kernel build, unless he takes the time to understand the build instructions, recognize the errors, and fix them on his own. As supplied, the CirrusLogic instructions are defective the just do not work. It appears that CirrusLogic's official "Build the Code" guide is just defective. It almost seems as if someone did a half-baked job of writing the instructions, as it looks like they didn't even bother to verify that the build instructions actually work, because as they are written they will not work.
Overall, I'm quite disappointed with my purchase for a couple of reasons:
1. The CirrusLogic Audio card is being advertised as being compatible with the new quadcore RPi2, when the reality is that it doesn't work because the kernel drivers for ARM7 are vaporware.
2. Falling back to using the CirrusLogic Audio Card with ARM6 on the RPi B+ isn't an option, as CirrusLogic's Official "Build the Code" guide contains errors and doesn't even work.
CirrusLogic needs to take the time to fix these problems, so that the product they're selling actually works like it's advertised to work. Unfortunately, if you take the time to survey the web, you'll find plenty of people who are having problems getting the platform to work. You shouldn't have to be a linux kernel developer, and you shouldn't have to recognize the errors in CirrusLogic's instructions and correct them yourself in order to get this product to work. Overall, I'm quite disappointed.