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New reworked driver for Wolfson/Cirrus Logic audio card

hiassoft

I've been working on a driver rework, mainly to get rid of the requirement to carry around a bunch of patches to upstream driver code, and also to fix some outstanding issues and introduce some new features.

 

Most issues have been ironed out so here's the first public release.

 

Edit: the driver has been included in official RPi kernels. Just run sudo rpi-update to install it.

You still have to install the mixer scripts and add the /etc/modprobe.d file. See my website for details

RPi Linux driver for Wolfson / Cirrus Logic Audio Card

 

Source: https://github.com/HiassofT/rpi-linux/tree/cirrus-ng-4.9.0

Precompiled kernel: http://www.horus.com/~hias/tmp/cirrus/cirrus-ng-linux-4.9.0.tgz

New mixer scripts: http://www.horus.com/~hias/tmp/cirrus/cirrus-ng-scripts.tgz

 

Important notes:

  • The new driver bases on the rather fresh kernel 4.9.0 which means there's some risk of (yet unknown) issues. Use it at your own risk and please run "rpi-update" to get the latest firmware before installing the new driver.
  • The soundcard name has been changed from "snd_rpi_wsp" to "RPi-Cirrus", also several ALSA controls have been removed and new ones were added. This means the old usecase scripts and any custom-made scripts will no longer work. Use the new mixer scripts instead of the old usecase/listen scripts.
  • The new driver supports setting (and receiving) of the S/PDIF channel status bits (aka AES bits). If you add an ALSA card configuration file this means applications like Kodi can do proper AC3/DTS passthrough. A sample card configuration file (plus the mixer scripts) can be found here: https://github.com/HiassofT/rpi-cirrus-config
  • I haven't fully updated the documentation on my website RPi Linux driver for Wolfson / Cirrus Logic Audio Card  yet, will do that during the next weeks/months. But except for the things noted above most stuff should still work as in previous driver versions.

 

Please report back if you tested the driver (either successfully or unsuccessfully), any feedback will help me!

 

so long,

 

Hias

Parents

  • Hias,

    A huge thank-you for all the work you've put into supporting the Cirrus Audio card.  Until now I've been using your kernel packages, and have just got round to trying the latest official 4.9 kernel which is also working very nicely.  It's a real shame that the Cirrus card has (or appears to have) gone out of production just when the software support became so good.  The older Wolfson cards are still available, so perhaps I'll get a couple and try modifying them to fit a 40-pin header.  Anyway, thanks again for everything you've done.  I really do appreciate it.

    Tim

  • in reply to timg73

    The Cirrus Card does seem to be out of stock everywhere - what a shame.  I just started working on an alternative ultrasound sensistive microphone, since the electret type I was using has been out of production for years and is now virtually impossible to get hold of.

     

    What other options are there for recording audio at 192kHz with the Raspberry Pi?

     

  • in reply to hystrix

    Tim and hysterix,

     

    Do not dispair.

     

    If you look earlier in this thread (2 weeks ago)  Matthias and I were discussing how to adapt the Wolfson variant of this card to run on Pi2/3.  He should take all the credit for verifying that this is a simple matter  ..... indeed trivial from a software perspective.  The hardware modifications are not to everybodys taste and I am still looking into less obtrusive ways of making the adaptation (using a piggy back board, eg)

    image

    Trouble is it needs to be double sided, plated through and gold plated on the 8 "thick" pads!  But such a board (with connectors installed) would allow the Wolfson card to plug into a Pi 2/3 with no hardware modifications to either (Hias, if you are reading this, can you confirm that I have not done something stupid like reverse clks or tx/rx?).  For the more intrepid/impatient, the solution which Hias has already posted works perfectly.  For those who do not want to unsolder the 8 pin pogo connector, you can cut-off pin 2 of the connector (which snags the I2C pull up resistor on the Pi) and place a small piece of insulating material beneath the pins for extra safety.  That would make the only unsoldering the removal of one resistor on the Wolfson card.

  • in reply to psyj

    Hi John. I have a spare Wolfson card, so I might try adapting it for Pi2/3.

     

    It's a shame that the Wolfson card doesn't have Line In micbias, but I could live with that.

     

    Many thanks for the info.

  • in reply to hystrix

    Hi,

     

    Interesting,  I really had not investigated that part of the schematics.  You are right of course  ..... can you not tie the inputs to the bias as the signal leaves the jack socket? Much easier there as you are not working at a microscopic scale.

     

    Let us all know what route you take for the modification  ..... as you rightly note the only way of using the Wolfson device is through this card, so we all need to work on finding the best way forward. Best of luck

  • in reply to psyj

    Hi John - Is removing R39 on the Wolfson board absolutely essential?

     

Reply Children
  • in reply to hystrix

    Hystrix

     

    As always Hias is the guru, but (for a direct plug in connection between pi and Wolfson) yes removal of R39 is necessary, otherwise you will be pumping the I2S bit clock directly into the 8804 SPDIF chip CSB pin.

     

    This (and the pogo connector) are the reasons I am looking at a piggy back board .... I do not trust myself on components of that size. The down side of this is board construction and the extra height that is involved in the sandwich as a whole

     

    If you do not want to unsolder R39 and do not want to use a piggy back board, the only alternative is to cut pin 12 out of the 40 way connector on the pi and run a flying lead from the stump of that pin up to pin 3 of the pogo connector on the W (working on cutting one of the tracks on the Wolfson board is in my opinion more difficult than removing R39). If you have no intention of reusing the pi with its expansion header, this is perhaps the easiest modification