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Cirrus Logic Audio Card working on the Raspberry Pi 2

Former Member

Hi all!

 

As you might know, Cirrus Logic's main kernel source branch recently switched to 3.18.

My first thought was "Hmm, that means the Cirrus Logic card could finally work on the RPi2..."

I have built a couple of 3.18 kernels for my B+ and RPi2 and I have managed to get both models to produce sound image

 

It's still early days, i.e. there are possibly bugs and glitches to fix, but for those of you who would like to try it out I've made an image file that you can download here:

https://drive.google.com/file/d/0BzIaxMH3N5O1cmJ1bFhMcG1hc0E/view?usp=sharing

The file is a 1.3 GB zip. Uncompressed size is 3.1 GB, so it fits comfortably on a 4 GB card.


The image is based on the standard 2015-02-16-raspbian-wheezy image from the Foundation that you flash to a SD card for a fresh install.

I have only added my kernels and set up the configuration files to get the card going.

It should work on the older B model  with a Wolfson Audio Card too, but I haven't tested that yet.

 

Have fun!

--

Ragnar

Parents Reply Children
  • in reply to Former Member

    One additional question:

     

    If i like to activate a sound output, it is only necessary to run one of the use case scripts once, right! If I run all use case scripts once, are all output devices enabled then, or can only one output be activated at the same time?

     

    Thanks, Thomas

  • in reply to Former Member

    If i like to activate a sound output, it is only necessary to run one of the use case scripts once, right?

    Yes.

    If I run all use case scripts once, are all output devices enabled then?

    Yes.

     

    Furthermore, on Raspbian, the state of the sound card(s) is saved at shutdown and restored at boot by the /etc/init.d/alsa-utils script.

    --

    Ragnar

  • in reply to Former Member

    Hi Ragnar,

    perfect! Thanks a lot for your quick answer! So I have only to wait for my new Wolfson card to see if everything is working with the new card and the Pi 2. If yes, I'll support the Wolfson card in SqueezePlug soon!

     

    Thanks, Thomas

     

    P.S.: Do you have a hint for the right output level for headphone and lineout? I saw that the output level is very high, compared with other devices like HiFiBerry. And how to set the right values with a  shell command?

  • in reply to Former Member

    Yes, the levels are hot. The reference level for 0 dB on Line Out is 0 dBV (1V RMS), whereas most consumer gear is -10 dBV (0.316 V RMS).

    This script is what I use most of the time to initialize the outputs. It's just the three standard "Playback_to..." scripts copy-and-pasted together.

     

    #!/bin/bash

#Playback from RPi to Headset
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1 Digital Switch' on
# Set path gain to -6dB for safety. ie max 0.5Vrms output level.
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1 Digital Volume' 116 # 96=-16dB. Volume control in 0.5 dB steps, -64dB to +32dB. Valid values 0-191. 128=0dB.
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1L Input 1' AIF1RX1
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1L Input 1 Volume' 32 # Input gain in 1 dB steps. -32dB to +12dB. Valid values 0-48. 32=0dB.
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1R Input 1' AIF1RX2
amixer -q -Dhw:sndrpiwsp cset name='HPOUT1R Input 1 Volume' 32


#Playback from RPi to LineOut
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2 Digital Switch' on
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2 Digital Volume' 128 # 108 = -10dB
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2L Input 1' AIF1RX1
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2L Input 1 Volume' 32
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2R Input 1' AIF1RX2
amixer -q -Dhw:sndrpiwsp cset name='HPOUT2R Input 1 Volume' 32

#SPDIF Playback: 

amixer -q -Dhw:sndrpiwsp cset name='SPDIF out Switch' on
amixer -q -Dhw:sndrpiwsp cset name='Input Source' AIF
amixer -q -Dhw:sndrpiwsp cset name='AIF2TX1 Input 1' AIF1RX1
amixer -q -Dhw:sndrpiwsp cset name='AIF2TX1 Input 1 Volume' 32 # 22 = -10dB
amixer -q -Dhw:sndrpiwsp cset name='AIF2TX2 Input 1' AIF1RX2
amixer -q -Dhw:sndrpiwsp cset name='AIF2TX2 Input 1 Volume' 32 # 22 = -10dB

    It sets Line Out and S/PDIF Out to 0 dB, i.e no amplification nor attenuation. The rationale here is that those outputs are connected to devices which have their own volume controls. Also, my analog gear is professional stuff that can take even hotter signals.

    Headset Out is set to -6 dB, to avoid ear-shattering surprises. The actual sound level I get varies a lot depending on which headphones I use. In modern ones it's still a bit too loud for my taste, but in my old 600-ohm favorites, it's just right.

     

    So, my hint would be to take the above script and edit it to decrease levels with 10 dB on lines 6 and 15. Then, I think you'll have a good starting point.

    As you can see, the magic command to set levels is amixer using its cset option.

    --

    Ragnar