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Re: port-macppc/39414: No audio from awacs on PowerBook G3 (Firewire/Pismo)
The following reply was made to PR port-macppc/39414; it has been noted by
From: "Marco Trillo" <marcotrillo%gmail.com@localhost>
Subject: Re: port-macppc/39414: No audio from awacs on PowerBook G3
Date: Thu, 28 Aug 2008 11:41:03 +0200
On Thu, 28 Aug 2008 01:00:09 +0000 (UTC), David H. Gutteridge said:
> This might also be applicable for original clamshell iBooks. I can
> test this when I have a moment. (I guess I need to track down the
> model name in OpenFirmware.)
I don't think so; original clamshell iBooks don't have an AWACS.
The codec in the clamshell iBooks is a "Micronas-Intermetall DAC
3550A" (Apple calls it a "Daca") and it's attached to the controller
via an I2S bus. Control commands can be issued to the codec via the
ki2c I2C bus.
The code for the I2S bus as well as the DMA transfers can be the same
as in the snapper(4) driver, but this does not apply to the GPIO code
which is snapper specific.
A datasheet is available here: <http://www.indata.si/grega/pdfs/dac3550a.pdf>
In the iBooks only speaker or headphones may be active at one moment.
Speaker is "activated" by enabling the "invert right power amplifier"
bit in GCFG; to use the headphones jack the bit needs to be
Headphone presence is checked in extint-gpio12 (IOBase + 0x64) via bit
0x02. It should produce an interrupt on IRQ 58. This info is available
on the "gpio" OF node as well as in the "sound-objects" property of
the "sound" node.
Hope that helps.
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