Messages in this thread | | | From | Rob Herring <> | Date | Fri, 25 Oct 2019 18:32:29 -0500 | Subject | Re: [RFC][PATCH 1/3] dt-bindings: dma-buf: heaps: Describe CMA regions to be added to dmabuf heaps interface. |
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On Fri, Oct 25, 2019 at 5:51 PM John Stultz <john.stultz@linaro.org> 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. ;)
> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Laura Abbott <labbott@redhat.com> > Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org> > Cc: Sumit Semwal <sumit.semwal@linaro.org> > Cc: Liam Mark <lmark@codeaurora.org> > Cc: Pratik Patel <pratikp@codeaurora.org> > Cc: Brian Starkey <Brian.Starkey@arm.com> > Cc: Andrew F. Davis <afd@ti.com> > Cc: Chenbo Feng <fengc@google.com> > Cc: Alistair Strachan <astrachan@google.com> > Cc: Sandeep Patil <sspatil@google.com> > Cc: Hridya Valsaraju <hridya@google.com> > Cc: devicetree@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > .../bindings/dma/dmabuf-heap-cma.txt | 31 +++++++++++++++++++ > 1 file changed, 31 insertions(+) > create mode 100644 Documentation/devicetree/bindings/dma/dmabuf-heap-cma.txt > > diff --git a/Documentation/devicetree/bindings/dma/dmabuf-heap-cma.txt b/Documentation/devicetree/bindings/dma/dmabuf-heap-cma.txt > new file mode 100644 > index 000000000000..bde7b1f1c269 > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/dmabuf-heap-cma.txt > @@ -0,0 +1,31 @@ > +* DMA-BUF CMA Heap > + > +Specifies a CMA region that should be added to the dma-buf heaps > +interface. > + > +Required properties: > +- compatible: Must be "dmabuf-heap-cma" > +- memory-region: phandle to a CMA reserved memory node > + > +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?
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.
Rob
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