On Fri, Oct 25, 2019 at 4:32 PM Rob Herring <rob.e.herring@xxxxxxxxx> wrote:
>
> On Fri, Oct 25, 2019 at 5:51 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> >
> > This binding specifies which CMA regions should be added to the
> > dmabuf heaps interface.
>
> Is this an ION DT binding in disguise? I thought I killed that. ;)
Maybe? I may not have been paying attention back then. :)
> > +Example:
> > +This example has a camera CMA node in reserved memory, which is then
> > +referenced by the dmabuf-heap-cma node.
> > +
> > +
> > + reserved-memory {
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > + ranges;
> > + ...
> > + cma_camera: cma-camera {
> > + compatible = "shared-dma-pool";
> > + reg = <0x0 0x24C00000 0x0 0x4000000>;
> > + reusable;
> > + };
> > + ...
> > + };
> > +
> > + cma_heap {
> > + compatible = "dmabuf-heap-cma";
> > + memory-region = <&cma_camera>;
>
> Why the indirection here? Can't you just add a flag property to
> reserved-memory nodes like we do to flag CMA nodes?
Happy to try. Do you mean like with the "reuasable" tag? Or more like
the "linux,cma-default" tag?
Do you have a preference for the flag name here?
> As I suspected, it's because in patch 2 you're just abusing DT to
> instantiate platform devices. We already support binding drivers to
> reserved-memory nodes directly.
Sorry, one of those "when all you know how to do is hammer, everything
looks like a nail" issues.
Is there a specific example for binding drivers to reserved-memory
nodes I can try to follow?
Appreciate the review and feedback!
thanks
-john
