[Arm-netbook] Multi-channel audio support

[lkcl luke]

On Sat, Dec 31, 2011 at 4:39 PM, jonsmirl at gmail.com <jonsmirl at gmail.com> wrote:
> On Sat, Dec 31, 2011 at 10:59 AM, lkcl luke <luke.leighton at gmail.com> wrote:
>> On Sat, Dec 31, 2011 at 3:35 PM, jonsmirl at gmail.com <jonsmirl at gmail.com> wrote:
>>> I went through the datasheet.
>>>
>>> The chip does not have:
>>> 1) Intel HD audio support (not the same as AC97)
>>
>>  ah, remember that the datasheet is *not* the authoritative source.
>> only the source code is truly authoritative as it implements
>> everything.  take a look through the datasheet and see if you can find
>> mention of "SATA" or "PATA" in it.
>
> I would like to know if the chip has Intel HD audio support.

 i've mentioned that i may have seen an "audio" file in an "hdmi"
directory, or possibly an "hdmi" file in an "audio" directory.  it was
a fleeting glance however so you would have to double-check.


> Nothing I am able to look at indicates that it has HD audio support.

 the source code instructions are here:
https://alioth.debian.org/scm/?group_id=100475
 and a web interface here:
 https://alioth.debian.org/scm/browser.php?group_id=100475

 come on, john :)

>>
>>> 2) S/PDIF output
>>>
>>> It does have:
>>> 1) Eight high def capable i2s channels (our embedded hardware uses this)
>>> 2) Support for slave AC97 CODECs (not a high def solution)
>>
>>  ok, so again (apologies for pointing out that this is the 3rd time of
>> asking, jon) - would placing the 8 pins of I2S/AC97 pins on the 44-pin
>> expansion header be of assistance to you?
>
> No assistance.

 ok.

>  We do HD audio, AC97 is not HD capable.

 understood.

> We have to use
> the eight I2S channels and will design our own PCB to get access to
> them.

 ok.... we may be talking about the same thing.  page 37 of the
datasheet refers to pins on port PB.  port PB pins 5 through 12 are
I2S when on multiplex function "2" but *some* of those exact same pins
are AC97 *only* on multiplex function "3".

 so.

 if you are referring to the "eight I2S channels" as being the 8
channel output of the single I2S bus which is pins PB5 through 12,
then those 8 pins could be routed to the 8 spare pins of the 44-pin
expansion header.

 would _that_ help?

 l.

 p.s. it would, by a complete coincidence, also enable AC97 audio
(which you don't need but others might, by selecting multiplex
function 3 instead of 2 for those pins).