[alsa-devel] [PATCH] SMDK64XX I2S: Added machine driver for WM8580

[jassi brar]

Let me clarify, just in case,
The patch-2/10
 http://lists.infradead.org/pipermail/linux-arm-kernel/2009-September/000714.html
enables this MACHINE driver to run 2 channels(of the 6 possible) of
the I2S-v4 with
the extant S3C CPU drivers, which do the job fine.
The extant CPU drivers are inadequate only if we want 6channels and
h/w mixing support.

On Sun, Sep 20, 2009 at 4:31 PM, Mark Brown
<broonie at opensource.wolfsonmicro.com> wrote:
> On Sun, Sep 20, 2009 at 10:49:50AM +0900, jassi brar wrote:
>> On Sun, Sep 20, 2009 at 1:08 AM, Mark Brown
>
>> > I've applied this with a couple of additional fixups below.  I've added
>> > a dependency on BROKEN since the IISv4 support is not yet present so
>> > there's no chance of it working yet.
>
>> well, i sent patches for CPU support also. they are simply put on hold until
>> something is decided. if i were given a suggestion atleast i cud try doing that.
>> anyways, the machine driver will almost remain the same in future when we
>> the CPU support is there.
>
> I think there was enough feedback on the CPU patches?  IIRC the main
> issues were that the driver will need some way to tell that it's an
> IISv4 block (which it would be able to do with the existing arch/arm but
> not with the patches you sent)
Is it a bad idea to use only part, shared with I2S-v3, of I2S-v4
controller when the CPU
driver doesn't yet support other distinguishing features?
If yes, then I shud start writing the 6channel and h/w mixing stuff
for the CPU driver.
If no, then my patches can be accepted in current or modified form.
When 6channel  and/or h/w mixing is implemented in the CPU drivers we
just enable those features in the controller.

> and that the audio-bus clock has to be
> idmplemented so that the driver can probe (or the driver will need to be
> able to carry on if it can't get the clock).
somehow i missed emailing that patch. will resend with other parts.

>> Btw, I understand as soon as i see a newer for-2.6.xx branch i shud start
>> submitting against that. Right?
>
> For new features, yes.  Bug fixes should be done against the version
> destined for Linus' current tree if the issue applies there.
got it. thanks

Another question ...
The platform device s3c64xx_device_iisv4 is defined in
arch/arm/plat-s3c/dev-audio.c
whereas I2S_v4 is available only for S3C6410 and newer SoCs.
Shudn't we define it somewhere like arch/arm/plat-s3c64xx/dev-audio.c?
I ask because soon I'll be submitting the PCM controller CPU driver for S3C64XX
and i wish to define it for s3c64xx specific platform, not the generic s3c.
Please suggest.