Embedded I2S / 192khz

Embedded I2S / 192khz

[Andrew Paprocki]

Is anyone aware of a Linux/ALSA capable chip that can drive 192khz
I2S? I poked through the ASoC code and could only see 96khz
capability.

Thanks, -Andrew

Re: Embedded I2S / 192khz

[Mark Brown]

On Thu, May 08, 2008 at 09:50:32AM -0400, Andrew Paprocki wrote:

> Is anyone aware of a Linux/ALSA capable chip that can drive 192khz
> I2S? I poked through the ASoC code and could only see 96khz
> capability.

The PowerPC code in sound/soc/fsl (as of 2.6.25) supports up to 192kHz,
though it appears to require the codec to clock the bus.  The SuperH and
Alchemy code in:

   git://opensource.wolfsonmicro.com/linux-2.6-asoc

says they support up to 192kHz too.  PXA3xx should support this too when
it's done.

Re: Embedded I2S / 192khz

[Liam Girdwood]

On Thu, 2008-05-08 at 15:08 +0100, Mark Brown wrote:
> On Thu, May 08, 2008 at 09:50:32AM -0400, Andrew Paprocki wrote:
> 
> > Is anyone aware of a Linux/ALSA capable chip that can drive 192khz
> > I2S? I poked through the ASoC code and could only see 96khz
> > capability.
> 
> The PowerPC code in sound/soc/fsl (as of 2.6.25) supports up to 192kHz,
> though it appears to require the codec to clock the bus.  The SuperH and
> Alchemy code in:
> 
>    git://opensource.wolfsonmicro.com/linux-2.6-asoc
> 
> says they support up to 192kHz too.  PXA3xx should support this too when
> it's done.

heh, shows how much attention I've been paying lately to commits.

PX2xx (SSP) and i.MX3x (SSI) should also do 192kHz too. Interestingly
pxa2xx I2S almost manages (datasheet max is 48kHz) 192kHz but underruns
a bit!

Re: Embedded I2S / 192khz

[Andrew Paprocki]

Has anyone heard of this BridgeCo DM850 chip? It seems powerful, but
I'm not sure if there is any ALSA support from the company.. from the
datasheet:

"There are up to four Audio I/O ports, each with four I2S/I8S
interfaces operating at up to 192 kHz in both I2S and I8S
modes.

There are up to eight SPDIF interfaces operating at up to
192 kHz."

http://www.bridgeco.com/pdfs/850/adp_dm850_02_pma_chip-overv.pdf

-Andrew

On Thu, May 8, 2008 at 10:22 AM, Liam Girdwood
<lg@opensource.wolfsonmicro.com> wrote:
> On Thu, 2008-05-08 at 15:08 +0100, Mark Brown wrote:
>> On Thu, May 08, 2008 at 09:50:32AM -0400, Andrew Paprocki wrote:
>>
>> > Is anyone aware of a Linux/ALSA capable chip that can drive 192khz
>> > I2S? I poked through the ASoC code and could only see 96khz
>> > capability.
>>
>> The PowerPC code in sound/soc/fsl (as of 2.6.25) supports up to 192kHz,
>> though it appears to require the codec to clock the bus.  The SuperH and
>> Alchemy code in:
>>
>>    git://opensource.wolfsonmicro.com/linux-2.6-asoc
>>
>> says they support up to 192kHz too.  PXA3xx should support this too when
>> it's done.
>
> heh, shows how much attention I've been paying lately to commits.
>
> PX2xx (SSP) and i.MX3x (SSI) should also do 192kHz too. Interestingly
> pxa2xx I2S almost manages (datasheet max is 48kHz) 192kHz but underruns
> a bit!
>
>

Re: Embedded I2S / 192khz

[Liam Girdwood]

On Sat, 2008-05-10 at 14:15 -0400, Andrew Paprocki wrote:
> Has anyone heard of this BridgeCo DM850 chip? It seems powerful, but
> I'm not sure if there is any ALSA support from the company.. from the
> datasheet:

afaik, no. Do you know if there is Linux support for this chip ?

> 
> "There are up to four Audio I/O ports, each with four I2S/I8S
> interfaces operating at up to 192 kHz in both I2S and I8S
> modes.
> 
> There are up to eight SPDIF interfaces operating at up to
> 192 kHz."
> 
> http://www.bridgeco.com/pdfs/850/adp_dm850_02_pma_chip-overv.pdf

Looks nice for STB applications.

Liam

Re: Embedded I2S / 192khz

[Timur Tabi]

Mark Brown wrote:

> The PowerPC code in sound/soc/fsl (as of 2.6.25) supports up to 192kHz,
> though it appears to require the codec to clock the bus. 

That's only because the reference board I based the code on uses the codec as
the clock master.  If someone wants to make a board with an 8610 as the clock
master, I'd be happy to update the driver to support that.

-- 
Timur Tabi
Linux kernel developer at Freescale

Re: Embedded I2S / 192khz

[Liam Girdwood]

On Thu, 2008-05-08 at 09:50 -0400, Andrew Paprocki wrote:
> Is anyone aware of a Linux/ALSA capable chip that can drive 192khz
> I2S? 

Quite a few codecs can run at 192kHz, although I'm not aware of many SoC
CPU's that will support 192kHz I2S. Your best bet is using a SoC CPU
with a multi-function port (that also does I2S) as they tend to support
faster transfer rates (e.g. SSP on pxa, SSI on i.MX).

> I poked through the ASoC code and could only see 96khz
> capability.
> 

I guess 192kHz is missing from ASoC atm because there is no supported
codec hardware that needs it. Trivial to add.

Liam