[alsa-devel] [PATCH] ASoC drivers for the Freescale MPC8610 SoC

Jon Smirl jonsmirl at gmail.com
Wed Jan 2 18:12:00 CET 2008

On 1/2/08, Grant Likely <grant.likely at secretlab.ca> wrote:
> On 1/2/08, Jon Smirl <jonsmirl at gmail.com> wrote:
> > On 1/2/08, Timur Tabi <timur at freescale.com> wrote:
> > mpc8610_hpcd is the harder one to load since it doesn't have a device
> > tree entry. What you want to do it match on the compatible field of
> > the root node.
> >
> > static struct of_device_id fabric_of_match[] = {
> >         {
> >                 .compatible     = "fsl,MPC8610HPCD",
> >         },
> >         {},
> > };
> >
> > But this doesn't work since the root is the device tree isn't passed
> > down into the device probe code. (Could this be fixed?)
> The driver can always get the root node.  But better yet, instantiate
> the correct fabric device (probably as a platform_device) from the
> platform code.  Then the correct fabric driver can probe against it.

The meaning of this has finally sunk into my consciousness. The
platform code can create a device that isn't bound to a driver. So why
not make this an of_platform_device?  This is basically a pseudo
device that isn't in the device tree.

Alternatively, the best place for this device would be on the ASOC
bus, but the ASOC bus hasn't been created when the platform code runs.
Maybe I can figure out a place in the platform code to create this
device after the ASOC driver has loaded and created the bus. Does the
platform code get control back after loading all of the device

In the longer term I'd like to kill platform_bus on powerpc and only
use of_platform_bus. Platform_bus seems to be functioning like a
catch-all and collecting junk from lots of different platforms.

Jon Smirl
jonsmirl at gmail.com

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