MARIAN - Digital Audio Electronics PCIe ALSA driver

What's this all about?

This driver is intended to enable MARIAN PCIe audio cards to work with Linux. It is structured as a framework to support multiple cards and multiple series. As a first implementation the Clara E (MARIAN's Dante card) is provided. Within the framework it should be pretty easy to also add other Clara cards and even cards from the Seraph series.

OS support

The driver has been developed and tested on following systems:

• Ubuntu 20.04, Kernel 5.15
• Ubuntu 22.04, Kernel 6.2
• Debian 11, Kernel 5.10 RT
• Debian 12, Kernel 6.1 RT
• Armbian 23.8.3, Kernel 6.1 on a ROCKPro64

Since no funny magic is used it should easily work on other systems that support ALSA.

Supported Devices

• MARIAN Clara E, Rev.06-07
• MARIAN Clara Emin, Rev.01-02

Always make sure to have the corresponding firmware installed on the card by checking the PCI revision.

History

• Version 1.0.0: Initial release for Clara E
• Version 1.1.0: Added support for Clara Emin

Building the driver

This is no detailed instruction on to how make your system fit for building kernel drivers but to give a pointer in the right direction, on Debian based systems you might want to start with something like:

sudo apt-get install -y build-essential linux-headers-$(uname -r) libasound2-dev

As soon as all prerequisites to compile a Linux module are met, simply run make from the root directory. You can also use the update.sh script to automatically remove and insert the module after compilation.

Note: Since Debian 12 moved away from PulseAudio in favor of Pipewire you might want to alter the update script accordingly.

Permanently installing the module

After successfully building the driver automatically enable it at every boot with the following commands:

sudo make install
sudo depmod
echo "snd_marian" | sudo tee -a /etc/modules

Clara E specifics

As of 11/2023 the Clara E does not (yet) support changing the sample rate from the PCIe side. The sample rate has to be set from the Dante Controller Software prior to opening the audio device. The driver will report the currently set Dante sample rate as the only supported rate when opening the PCM devices.

There is an ALSA control named "Sample Rate" associated with the card interface for reference in user space. The driver also sends notifications to this control in case the sample rate is changed via the Dante Controller.

To get a glance at the ALSA controls without writing any custom software simply try:

amixer -c ClaraE contents

To test the notification functionality use:

amixer -c ClaraE events