On Fri, Oct 25, 2019 at 04:55:35PM -0700, John Stultz wrote:
On Fri, Oct 25, 2019 at 4:32 PM Rob Herring [off-list ref] wrote:
quoted
On Fri, Oct 25, 2019 at 5:51 PM John Stultz [off-list ref] wrote:
quoted
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. :)
quoted
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+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?
Probably like "linux,cma-default" as it is a hint for who to manage it
rather than a characteristic of the region.
Do you have a preference for the flag name here?
Not really.
quoted
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?
ramoops and I think there's a QCom driver.
Rob