From 76a96d86c8348c61b4abcb492a4892575833c3f9 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 30 Aug 2016 17:04:27 -0700 Subject: [PATCH] devicetree: bindings for Ion This adds a base set of devicetree bindings for the Ion memory manager. This supports setting up the generic set of heaps and their properties. Signed-off-by: Laura Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/devicetree.txt | 51 ++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 drivers/staging/android/ion/devicetree.txt diff --git a/drivers/staging/android/ion/devicetree.txt b/drivers/staging/android/ion/devicetree.txt new file mode 100644 index 000000000000..168715271f06 --- /dev/null +++ b/drivers/staging/android/ion/devicetree.txt @@ -0,0 +1,51 @@ +Ion Memory Manager + +Ion is a memory manager that allows for sharing of buffers via dma-buf. +Ion allows for different types of allocation via an abstraction called +a 'heap'. A heap represents a specific type of memory. Each heap has +a different type. There can be multiple instances of the same heap +type. + +Specific heap instances are tied to heap IDs. Heap IDs are not to be specified +in the devicetree. + +Required properties for Ion + +- compatible: "linux,ion" PLUS a compatible property for the device + +All child nodes of a linux,ion node are interpreted as heaps + +required properties for heaps + +- compatible: compatible string for a heap type PLUS a compatible property +for the specific instance of the heap. Current heap types +-- linux,ion-heap-system +-- linux,ion-heap-system-contig +-- linux,ion-heap-carveout +-- linux,ion-heap-chunk +-- linux,ion-heap-dma +-- linux,ion-heap-custom + +Optional properties +- memory-region: A phandle to a memory region. Required for DMA heap type +(see reserved-memory.txt for details on the reservation) + +Example: + + ion { + compatbile = "hisilicon,ion", "linux,ion"; + + ion-system-heap { + compatbile = "hisilicon,system-heap", "linux,ion-heap-system" + }; + + ion-camera-region { + compatible = "hisilicon,camera-heap", "linux,ion-heap-dma" + memory-region = <&camera_region>; + }; + + ion-fb-region { + compatbile = "hisilicon,fb-heap", "linux,ion-heap-dma" + memory-region = <&fb_region>; + }; + }