Katastrophos.net Blog

Today I’m officially releasing my extended driver and mixer for the Wolfson WM8750 CODEC / sound chip that comes included in the latest Zaurus models.
The driver exposes the following new features:

• ability to set and control Treble, Bass and 3D stereo sound enhancement;
• ability to set and control various cut-off frequencies supported by the sound chip;
• output source selection (Autodetect, Internal Speaker, Headphone).

These features can be easily accessed via a Qt based mixer control app or directly via a /proc/driver/wm8750 kernel interface.

Both, the driver and the control app are available for Sharp ROM / Cacko ROM and pdaXrom beta 3 / pdaXii13.

Kernel patches are available for Sharp’s Linux kernel 2.4.20 and can be downloaded here:
http://www.katastrophos.net/zaurus/sources/wm8750mixer/
(No kernel 2.6.x support yet. Sorry folks.)

By default the audio driver is compiled into the kernel. Sharp didn’t compile it as module, so it can’t be easily replaced. Same goes for most third party ROMs. You’ll have to reflash your kernel to install the new driver.
In case you don’t want to roll your own kernel, I’ve made pre-compiled kernels available for all supported ROMs and models here:

http://www.katastrophos.net/zaurus/kernels/v55/

The control app and start up scripts are available as IPK here:

wm8750mixer_0.9_arm.ipk - WM8750 mixer for Sharp ROM / Cacko ROM
wm8750mixer_0.92_armv5tel.ipk - WM8750 mixer for pdaXrom beta 3 / pdaXii13

On a side note, we’ve been discussing the extended features of the WM8750 audio chip for quite some while in this thread over at the OESF forums. I have the feeling the driver and the Qt application have received a fair bit of testing. So, that’s why I am officially releasing it today.