Re: Tegra DRM device tree bindings

[Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

On Wed, 27 Jun 2012 04:32:07 +0200
Mark Zhang <markz-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:

> > On 06/26/2012 07:46 PM, Mark Zhang wrote:
> > >>> On Tue, 26 Jun 2012 12:55:13 +0200
> > >>> Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org> wrote:
> > ...
> > >> I'm not sure I understand how information about the carveout would be
> > >> obtained from the IOMMU API, though.
> > >
> > > I think that can be similar with current gart implementation. Define carveout as:
> > >
> > > carveout {
> > >         compatible = "nvidia,tegra20-carveout";
> > >         size = <0x10000000>;
> > > };
> > >
> > > Then create a file such like "tegra-carveout.c" to get these definitions and
> > register itself as platform device's iommu instance.
> > 
> > The carveout isn't a HW object, so it doesn't seem appropriate to define a DT
> > node to represent it.
> > --
> 
> Yes. But I think it's better to export the size of carveout as a configurable item.
> So we need to define this somewhere. How about define carveout as a property of gart?

I agree that the carveout size should be configurable. But it may not be related to gart.