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From: Timur Tabi <timur@freescale•com>
To: Jon Smirl <jonsmirl@gmail•com>
Cc: PowerPC dev list <Linuxppc-dev@ozlabs•org>
Subject: Re: Device trees and audio codecs
Date: Mon, 22 Oct 2007 08:07:14 -0500	[thread overview]
Message-ID: <471CA082.1050304@freescale.com> (raw)
In-Reply-To: <9e4733910710210701x67b2e99frd0784ac2c8bd27fd@mail.gmail.com>

Jon Smirl wrote:

> Doing it that way will make the kernel specific to the target device.
> Currently I can load the same mpc5200 kernel on several different
> target devices since the platform specific code is triggered in the
> probe machine phase.

Maybe I need to take a look at your code, but the fabric driver is, in 
effect, a platform-specific driver.  Its job is to figure out what 
hardware is on the board, how it's connected, and then initialize and 
connect the other drivers as appropriate.

> I tried making the fabric driver into a platform driver instead of an
> openfirmware driver, but the mpc5200 code is not initializing platform
> drivers correctly.

Yeah, that wouldn't work.  Platform drivers are initialized way too early.

> I could insert calls into arch/powerpc/platforms/52xx/whatever to load
> the specific asoc fabric, but doing that is a mess. There must be a
> way to trigger loading of machine specific drivers

Either you do it at driver __init time, or via a probe.  The probe 
actually occurs at __init time, anyway, so they're kinda the same thing. 
  The only thing the probe gets you is that you're called multiple times 
for each instance of a node in the tree.

>> Since the Apple audio drivers are not ASoC drivers, I suggest we don't pay
>> attention to what they do.
> 
> Those Apple drivers are very similar to asoc drivers. They could
> easily be folded into the asoc code.

Perhaps, but that's a job for another day (and another developer).

  reply	other threads:[~2007-10-22 13:07 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-20 15:33 Device trees and audio codecs Jon Smirl
2007-10-21 13:33 ` Timur Tabi
2007-10-21 14:01   ` Jon Smirl
2007-10-22 13:07     ` Timur Tabi [this message]
2007-10-23 19:12       ` Scott Wood
2007-10-21 19:14 ` Segher Boessenkool
2007-10-21 21:33   ` Jon Smirl
2007-10-21 22:06     ` Benjamin Herrenschmidt
2007-10-21 22:12       ` Jon Smirl
2007-10-21 22:19         ` Benjamin Herrenschmidt
2007-10-21 23:33     ` Segher Boessenkool
2007-10-22  0:29       ` Jon Smirl
2007-10-22 15:40         ` Timur Tabi
2007-10-22 18:43         ` Segher Boessenkool
2007-10-23  3:24         ` Grant Likely

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