Re: [PATCH 8/9] dt-bindings: reserved-memory: MediaTek: Add reserved memory for SVP

[Vijayanand Jitta]

On 9/11/2023 8:00 AM, Yong Wu wrote:
> This adds the binding for describing a CMA memory for MediaTek SVP(Secure
> Video Path).
> 
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> ---
>  .../mediatek,secure_cma_chunkmem.yaml         | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reserved-memory/mediatek,secure_cma_chunkmem.yaml
> 
> diff --git a/Documentation/devicetree/bindings/reserved-memory/mediatek,secure_cma_chunkmem.yaml b/Documentation/devicetree/bindings/reserved-memory/mediatek,secure_cma_chunkmem.yaml
> new file mode 100644
> index 000000000000..cc10e00d35c4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/mediatek,secure_cma_chunkmem.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/reserved-memory/mediatek,secure_cma_chunkmem.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek Secure Video Path Reserved Memory
> +
> +description:
> +  This binding describes the reserved memory for secure video path.
> +
> +maintainers:
> +  - Yong Wu <yong.wu@xxxxxxxxxxxx>
> +
> +allOf:
> +  - $ref: reserved-memory.yaml
> +
> +properties:
> +  compatible:
> +    const: mediatek,secure_cma_chunkmem
> +
> +required:
> +  - compatible
> +  - reg
> +  - reusable
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +
> +    reserved-memory {
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +        ranges;
> +
> +        reserved-memory@80000000 {
> +            compatible = "mediatek,secure_cma_chunkmem";
> +            reusable;
> +            reg = <0x80000000 0x18000000>;
> +        };
> +    };

Instead of having a vendor specific binding for cma area, How about retrieving
https://lore.kernel.org/lkml/1594948208-4739-1-git-send-email-hayashi.kunihiko@xxxxxxxxxxxxx/ ?
dma_heap_add_cma can just associate cma region and create a heap. So, we can reuse cma heap
code for allocation instead of replicating that code here.

Thanks,
Vijay