Turning on sound in the new iBook

Turning on sound in the new iBook

[Paul Harrison]

A few people have asked me about this, so i thought i would post it here:
I have sound working on the new iBook, mostly from looking at the Darwin
source.

The basic steps were:
- powering up the sound system and one of the amps by writing to some
ports
- setting up the digital equalizer using I2C
- using the dmasound_pmac module for actual sound output

Full details here:

http://yoyo.cc.monash.edu.au/~pfh/ibook/sound.html

This is all really, really hacked together. It should all probably be put
together in one or two nice neat kernel modules at some stage.

--
Paul Harrison

Email: pfh@csse.monash.edu.au
Web:   http://yoyo.cc.monash.edu.au/~pfh/


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Re: Turning on sound in the new iBook

[Bastien Nocera]

Hi Paul,

Just got around trying it, and it works in the sense that "cat /vmlinux
 > /dev/dsp" produces sound ;)
The sound although contains a *lot* of noise. You're mentioning on your
page a modification to dmasound_core, could you share it with us ?

Cheers

Paul Harrison wrote:

>A few people have asked me about this, so i thought i would post it here:
>I have sound working on the new iBook, mostly from looking at the Darwin
>source.
>
>The basic steps were:
>- powering up the sound system and one of the amps by writing to some
>ports
>- setting up the digital equalizer using I2C
>- using the dmasound_pmac module for actual sound output
>
>Full details here:
>
>http://yoyo.cc.monash.edu.au/~pfh/ibook/sound.html
>
>This is all really, really hacked together. It should all probably be put
>together in one or two nice neat kernel modules at some stage.
>
>--
>Paul Harrison
>
>Email: pfh@csse.monash.edu.au
>Web:   http://yoyo.cc.monash.edu.au/~pfh/
>
>
>


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Re: Turning on sound in the new iBook

[Iain Sandoe]

Hi Chaps,

> Just got around trying it, and it works in the sense that "cat /vmlinux
>  > /dev/dsp" produces sound ;)
> The sound although contains a *lot* of noise. You're mentioning on your
> page a modification to dmasound_core, could you share it with us ?

Someone (Jack Moffitt IIRC) reported to me that the Tumbler needed to be
U16.  Having looked at the Darwin code I can find no evidence of this in
Apple's stuff ... however, it might not be up-to-date.

There are a lot of assumptions in dmasound that are related to the AWACS -
especially in the bits that deal with things like the mksound().

I am working on rationalising the driver to partition out stuff that relates
to the AWACS/Screamer/Burgundy - so that the dbdma drive part of it (shared
between _core.c and _awacs.c can be used).

Ironically, it is the mksound() [SysBeep()] code that is giving me most
grief... (in thinking of a better way to do it so that it is not so
chip-dependent).

I'd like to get this done first - because it paves the way for more sensible
driver structure - and, in particular, making the SMP locking sensible.

---

IMHO the most important tumbler/DACA task is getting the keywest-i2c stuff
to be interrupt driven - it is nasty having polled code that might lock up
the kernel for seconds.

---

If the tumbler really needs to be U16 - I can modify the standard code to
make that as another 'exception'.

time is, as always, the killer here...

ciao,
Iain.

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