kw I²C

kw I²C

[Tristan Plumb]

I'm working on a audio driver for kw (openrd) as a warmup for other more
useful drivers (do something easy before something hard), and I've come
to the point where to do anything more requires talking to the audio
codec. According to various linux patches, this is done over I²C. Has
anyone done anything with I²C, is it used for anything else? The kirkwood
functional specification does not mention it (at least so far as I can
see in the copy I have). Elseways I'll scrounge around some more.

Thoughts?

tristan

--
All original matter is hereby placed immediately under the public domain.

Re: [9fans] kw I²C

[Bankim Bhavsar]

By I²C, you mean Immediate Command/Response Interface of HDAudio controller?

Though Immediate Command/Response Interface should work, CORB/RIRB is
the recommended way to send/receive commands/responses from the codec.

If you do use Immediate mode, please refer to the updated HDAudio spec
that clarifies use of ICB bit in ICIS register.
http://www.intel.com/standards/hdaudio/pdf/hda002-a.pdf

Thanks,
Bankim.

On Fri, Sep 3, 2010 at 4:08 PM, Tristan Plumb <9p-st@imu.li> wrote:
> I'm working on a audio driver for kw (openrd) as a warmup for other more
> useful drivers (do something easy before something hard), and I've come
> to the point where to do anything more requires talking to the audio
> codec. According to various linux patches, this is done over I²C. Has
> anyone done anything with I²C, is it used for anything else? The kirkwood
> functional specification does not mention it (at least so far as I can
> see in the copy I have). Elseways I'll scrounge around some more.
>
> Thoughts?
>
> tristan
>
> --
> All original matter is hereby placed immediately under the public domain.
>
>

Re: [9fans] kw IC

[erik quanstrom]

On Fri Sep  3 19:09:18 EDT 2010, 9p-st@imu.li wrote:
> I'm working on a audio driver for kw (openrd) as a warmup for other more
> useful drivers (do something easy before something hard), and I've come
> to the point where to do anything more requires talking to the audio
> codec. According to various linux patches, this is done over I²C. Has
> anyone done anything with I²C, is it used for anything else? The kirkwood
> functional specification does not mention it (at least so far as I can
> see in the copy I have). Elseways I'll scrounge around some more.
>

if i read the marvell specification correctly, it uses i²s, not i²c.
wikipedia has a pointer to the phillips specification.

the main thing they have in common is that they both pass
at least one of ron's "how to tell if a specification sucks" tests.
:-)

- erik

Re: [9fans] kw IC

[ron minnich]

On Fri, Sep 3, 2010 at 5:11 PM, erik quanstrom <quanstro@quanstro.net> wrote:


> the main thing they have in common is that they both pass
> at least one of ron's "how to tell if a specification sucks" tests.
> :-)


They have the added advantage of the exponent after the I.

Reminds me of the degrees of infinity.

So instead of sucketh-null, I guess they are sucketh-1?

ron

Re: [9fans] kw IC

[erik quanstrom]

> They have the added advantage of the exponent after the I.
>
> Reminds me of the degrees of infinity.
>
> So instead of sucketh-null, I guess they are sucketh-1?

so you're working on a new concurrent language for plan 9?

- erik

Re: [9fans] kw IC

[andrey mirtchovski]

Our university has an iS² project. iS² stands for Innovative Support
Services. The project's goal is to maximize efficiencies. It's used as
the excuse to fire a few support personnel.

Re: [9fans] kw IC

[andrey mirtchovski]

hmm. oops. that was supposed to be private.

andrey courtesy of the department of redundancy dept.

Re: [9fans] kw IC

[EBo]

> So instead of sucketh-null, I guess they are sucketh-1?

ROFLOL!!!

Re: [9fans] kw IC

[Akshat Kumar]

On Fri, Sep 3, 2010 at 5:47 PM, ron minnich <rminnich@gmail.com> wrote:
> They have the added advantage of the exponent after the I.
>
> Reminds me of the degrees of infinity.
>
> So instead of sucketh-null, I guess they are sucketh-1?

Ron,

the suck is uncountable

ak

Re: kw I²C

[Tristan Plumb]

eric quanstrom:
> if i read the marvell specification correctly, it uses i²s, not i²c.
> wikipedia has a pointer to the phillips specification.
It uses i²s to for the data (sound) transport. the control for the codec
is seperate, the codec is a cs42l51, which has an i²s interface for data
and either an i²c or spi interface for control, with the spi write-only.

Bankim Bhavsar:
> Though Immediate Command/Response Interface should work, CORB/RIRB is
> the recommended way to send/receive commands/responses from the codec.
Reading the datasheet of the codec, I havn't found any mention of CORB or
RIRB, so I would hazard a guess that that's not what I want. But still,
what is CORB/RIRB?

In light of further digging, the functional specification does talk about
"TWSI Bus Operation". twsi ≅ i²c. I guess I'll work on that now. Which,
according to the openrd schematics, connects to the audio codec and
the SMBus connector.

...
tristan

--
All original matter is hereby placed immediately under the public domain.

Re: [9fans] kw I²C

[Bankim Bhavsar]

>> Though Immediate Command/Response Interface should work, CORB/RIRB is
>> the recommended way to send/receive commands/responses from the codec.

> Reading the datasheet of the codec, I havn't found any mention of CORB or
> RIRB, so I would hazard a guess that that's not what I want. But still,
> what is CORB/RIRB?

Sorry for the confusion. I think you are referring to a different audio card.

For the Intel High-Definition Audio Controller
(http://www.intel.com/standards/hdaudio/pdf/HDAudio_01.pdf)

CORB = Command Output Ring Buffer
RIRB = Response Input Ring Buffer

This is the mechanism used by HDAudio Controller to communicate with
the codec attached.

-Bankim.