Cirrus Logic S/PDIF

Cirrus Logic S/PDIF

[Peter Heatwole]

Hello,

    I have a CS4281 based card with a CS4297A AC'97 codec, and wanted
to use the IEC958 jack. After reading some of the specs, I realized
that the function "patch_cirrus_cs4205()" in ac97_codec.c applies to
the CS4297A codec as well. I changed the line in the snd_ac97_codec_ids
array that corresponds to the CS4297A, and made it use the CS4205 patch,
and the codec successfully copies the data to the iec958 jack as well
as analog out.
    What would be the drawbacks to setting this line in the CVS? I realize
this will not work for all soundcards using the CS4297A (for instance, I
used this patch with my Santa Cruz (CS4630 DSP), with no luck, as 
expected),
but would using the patch cause harm?
    I have not checked, but I assume this would also apply to other Cirrus
Logic AC'97 codecs?

(Any additional info/corrections you may send me via personal mail would
also be much appreciated.)


-- Peter Heatwole
"Murphy was just a well known pessimist."

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Re: Cirrus Logic S/PDIF

[Takashi Iwai]

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Hi Peter,

At Fri, 17 May 2002 08:24:15 -0700,
Peter Heatwole wrote:
> 
> Hello,
> 
>     I have a CS4281 based card with a CS4297A AC'97 codec, and wanted
> to use the IEC958 jack. After reading some of the specs, I realized
> that the function "patch_cirrus_cs4205()" in ac97_codec.c applies to
> the CS4297A codec as well. I changed the line in the snd_ac97_codec_ids
> array that corresponds to the CS4297A, and made it use the CS4205 patch,
> and the codec successfully copies the data to the iec958 jack as well
> as analog out.
>     What would be the drawbacks to setting this line in the CVS? I realize
> this will not work for all soundcards using the CS4297A (for instance, I
> used this patch with my Santa Cruz (CS4630 DSP), with no luck, as 
> expected),
> but would using the patch cause harm?

no, i don't think it harms.
the attached patch is what you mentioned above?
if it's ok, then i'll commit it to cvs.


>     I have not checked, but I assume this would also apply to other Cirrus
> Logic AC'97 codecs?

well, we need to check spec sheets to be sure.
could you tell us which chips did you check (to be supposed to work)?


Takashi

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Index: alsa-kernel/pci/ac97/ac97_codec.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/pci/ac97/ac97_codec.c,v
retrieving revision 1.15
diff -u -r1.15 ac97_codec.c
--- alsa-kernel/pci/ac97/ac97_codec.c	21 May 2002 09:34:54 -0000	1.15
+++ alsa-kernel/pci/ac97/ac97_codec.c	21 May 2002 10:46:02 -0000
@@ -113,7 +113,7 @@
 { 0x414c4740, 0xfffffff0, "ALC202",		NULL },
 { 0x414c4750, 0xfffffff0, "ALC250",		NULL },
 { 0x43525900, 0xfffffff8, "CS4297",		NULL },
-{ 0x43525910, 0xfffffff8, "CS4297A",		NULL },
+{ 0x43525910, 0xfffffff8, "CS4297A",		patch_cirrus_cs4205 },
 { 0x42525920, 0xfffffff8, "CS4294/4298",	NULL },
 { 0x42525928, 0xfffffff8, "CS4294",		NULL },
 { 0x43525930, 0xfffffff8, "CS4299",		patch_cirrus_cs4299 },

Re: Cirrus Logic S/PDIF

[Peter Heatwole]

On 2002.05.21 03:46 Takashi Iwai wrote:
> the attached patch is what you mentioned above?
> if it's ok, then i'll commit it to cvs.

    Yes. I just patched it into the latest CVS, and it worked
perfectly. 
>>    I have not checked, but I assume this would also apply to other
>>  Cirrus Logic AC'97 codecs?
> 
> well, we need to check spec sheets to be sure.
> could you tell us which chips did you check (to be supposed to work)?

    I only have two CS4297A based cards, so that's all I've tried so
far. I'll check the specs on the other Cirrus chips as soon as possible,
but will need someone else to test them.


-- Peter Heatwole
"Murphy was just a well known pessimist."


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Re: Cirrus Logic S/PDIF

[Takashi Iwai]

At Tue, 21 May 2002 08:41:16 -0700,
Peter Heatwole wrote:
> 
> On 2002.05.21 03:46 Takashi Iwai wrote:
> > the attached patch is what you mentioned above?
> > if it's ok, then i'll commit it to cvs.
> 
>     Yes. I just patched it into the latest CVS, and it worked
> perfectly. 

ok.  now checked into cvs.

> >>    I have not checked, but I assume this would also apply to other
> >>  Cirrus Logic AC'97 codecs?
> > 
> > well, we need to check spec sheets to be sure.
> > could you tell us which chips did you check (to be supposed to work)?
> 
>     I only have two CS4297A based cards, so that's all I've tried so
> far. I'll check the specs on the other Cirrus chips as soon as possible,
> but will need someone else to test them.

yep...


Takashi

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Re: Cirrus Logic S/PDIF

[Peter Heatwole]

On 2002.05.21 03:46 Takashi Iwai wrote:
> well, we need to check spec sheets to be sure.
> could you tell us which chips did you check (to be supposed to work)?

    I've looked through some spec sheets, and these are the chips that 
seem to be compatible with patch_cirrus_cs4205():

CS4201:   compatible
CS4298:   compatible. Register 5Eh (MODE_CS4205) doesn't seem to 
use             AMAP bit (0x0080), but that shouldn't affect anything
CS4299:   compatible. Maybe call patch_cirrus_cs4205() from
             patch_cirrus_4299()

    I've only checked those AC'97 codecs that are supported already. More 
codecs may support this patch, but I haven't checked any of the codecs not
listed in ac97_codec.c yet.

-- Peter Heatwole
"Murphy was just a well known pessimist."

_______________________________________________________________

Don't miss the 2002 Sprint PCS Application Developer's Conference
August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm

Re: Cirrus Logic S/PDIF

[Jaroslav Kysela]

On Tue, 21 May 2002, Peter Heatwole wrote:

> On 2002.05.21 03:46 Takashi Iwai wrote:
> > well, we need to check spec sheets to be sure.
> > could you tell us which chips did you check (to be supposed to work)?
> 
>     I've looked through some spec sheets, and these are the chips that 
> seem to be compatible with patch_cirrus_cs4205():
> 
> CS4201:   compatible
> CS4298:   compatible. Register 5Eh (MODE_CS4205) doesn't seem to 
> use             AMAP bit (0x0080), but that shouldn't affect anything

I haven't S/PDIF register in the CS4294 datasheet. Do you have CS4298 
datasheet?

> CS4299:   compatible. Maybe call patch_cirrus_cs4205() from
>              patch_cirrus_4299()

I'm working on it.

						Jaroslav

-----
Jaroslav Kysela <perex@suse.cz>
Linux Kernel Sound Maintainer
ALSA Project  http://www.alsa-project.org
SuSE Linux    http://www.suse.com


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Re: Cirrus Logic S/PDIF

[Peter Heatwole]

On 2002.05.22 01:06 Jaroslav Kysela wrote:
> I haven't S/PDIF register in the CS4294 datasheet. Do you have CS4298
> datasheet?

    Yes, the CS4294 doesn't have an S/PDIF pin. It's for quad speaker 
output,
and is normally paired with something like the CS4297A for S/PDIF (as is 
the
case with the Santa Cruz). And here's the CS4298 datasheet I'm using:

http://www.cirrus.com/pubs/pubs_current/4298.pdf


-- Peter Heatwole
"Murphy was just a well known pessimist."


_______________________________________________________________

Don't miss the 2002 Sprint PCS Application Developer's Conference
August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm