[MinnowBoard] I2S Audio on MinnowBoard MAX Windows

[David Anders]

Ryan,


> On November 20, 2014 at 10:38 AM "Roberts, Ryan" <Ryan.Roberts at cirrus.com>
> wrote:
> 
> 
> Hi David,
> 
> Thanks for your response. Is there a timeline for when the rev with
> PMC_PLT_CLK on the LSE will be available?
> 

i am sorry no, i can not provide a timeline as of yet.

as a side note, i do know that you can drive the LSE interface without the
reference clock, however it is more prone to noise and pops on the audio. you
should be able to do some minimal testing...

Dave


> Thanks,
> Ryan
> 
> 
> -----Original Message-----
> From: David Anders [mailto:danders at circuitco.com] 
> Sent: 20 November 2014 16:32
> To: MinnowBoard Development and Community Discussion; Roberts, Ryan
> Subject: Re: [MinnowBoard] I2S Audio on MinnowBoard MAX Windows
> 
> Ryan,
> 
> 
> > On November 20, 2014 at 7:37 AM "Roberts, Ryan" <Ryan.Roberts at cirrus.com>
> > wrote:
> > 
> > 
> > Hi there,
> > 
> > First of all, appologies if this is not the correct place for Minnowboard
> > MAX
> > **Windows** questions, I could only find this elinux mailing list. Please
> > direct me to the Windows list if it exists.
> > 
> 
> this list is for anything max related that the community can support. you are
> welcome to ask questions related to Microsoft Windows on MinnowMax, however,
> the
> vast majority of community users are using linux or other open source
> operating
> systems,
> 
> > I'm currently evaluating the suitability of MinnowBoard MAX as a platform
> > that
> > I could use for development and testing of Windows audio codec drivers. I
> > have
> > previous familiarity with the Baytrail LPE audio architecture and have a
> > driver that works on other Baytrail based systems.
> > 
> > I've been able to successfully modify the ACPI DSDT to expose my codec
> > device
> > and the correct LPE device (there are two LPE devices in the DSDT - one for
> > Android and the other for Windows. The BIOS seems to think it is booting to
> > Android so some changes are required). I've also successfully installed the
> > Intel LPE driver and Windows is happy that there are render and capture
> > endpoints available (playback is shown as working)...
> > 
> > However, I have 2 problems:
> > 
> > 
> > *         The LPE driver that I have is using I2S port 1 (the pins of which
> > are multiplexed with HAD and are not brought out to headers). The
> > MinnowBoard
> > MAX schematic shows that I2S port 2 is the one that is brought out to the
> > board's header. Is there an alternative LPE driver available that will use
> > this port instead? If so, can you advise on where I can get it? (I took the
> > driver that I'm currently using from Baytrail-T type 4).
> > 
> > 
> > 
> > *         The board does not bring out any of the PMC_PLT clocks out to the
> > header. Previously the audio codec has always used PMC_PLT_CLK[3] on
> > Baytrail
> > running at 25MHz as its master clock. How/where do you envisage that we
> > should
> > get MCLK when using MinnowBoard MAX? Are there any options other than
> > providing an external clock and attempting to synchronize to the I2S bit
> > clock
> > when it is active?
> > 
> 
> there is a current known hardware issue on this. during development of the max
> we had mistaken the capabilities of the ILB_8450_SPKR single as being able to
> be
> used for the reference clock. only after production did we find out this was
> not
> the case. 
> 
> https://bugzilla.yoctoproject.org/show_bug.cgi?id=6865
> 
> the next hardware revision of the Max will replace the ILB_8450_SPKR with one
> of
> the PMC_PLT_CLK signals.
> 
> Dave
> 
> 
> > Thanks in advance,
> > Ryan Roberts
> > 
> > 
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> If you are not an intended recipient you must not: read; copy; distribute;
> discuss; take any action in or make any reliance upon the contents of this
> message; nor open or read any attachment. If you have received this message in
> error, please notify us as soon as possible on the following telephone number
> and destroy this message including any attachments. Thank you. Wolfson
> Microelectronics Ltd is a company registered in Scotland, with registered
> number SC089839 and its registered office at Westfield House, 26 Westfield
> Road, Edinburgh, EH11 2QB, UK.  Tel: +44 (0)131 272 7000. cirrus.com