Hi Rob,
Thanks for your review.
On Mon, 2023-09-11 at 10:44 -0500, Rob Herring wrote:
>
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> On Mon, Sep 11, 2023 at 10:30:37AM +0800, Yong Wu wrote:
> > This adds the binding for describing a CMA memory for MediaTek
> SVP(Secure
> > Video Path).
>
> CMA is a Linux thing. How is this related to CMA?
> >
> > Signed-off-by: Yong Wu <[email protected]>
> > ---
> > .../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
>
> What makes this specific to Mediatek? Secure video path is fairly
> common, right?
Here we just reserve a buffer and would like to create a dma-buf secure
heap for SVP, then the secure engines(Vcodec and DRM) could prepare
secure buffer through it.
But the heap driver is pure SW driver, it is not platform device and
we don't have a corresponding HW unit for it. Thus I don't think I
could create a platform dtsi node and use "memory-region" pointer to
the region. I used RESERVEDMEM_OF_DECLARE currently(The code is in
[9/9]). Sorry if this is not right.
Then in our usage case, is there some similar method to do this? or
any other suggestion?
Appreciate in advance.
>
> > +
> > +description:
> > + This binding describes the reserved memory for secure video
> path.
> > +
> > +maintainers:
> > + - Yong Wu <[email protected]>
> > +
> > +allOf:
> > + - $ref: reserved-memory.yaml
> > +
> > +properties:
> > + compatible:
> > + const: mediatek,secure_cma_chunkmem
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - reusable
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > +
> > + reserved-memory {
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + ranges;
> > +
> > + reserved-memory@80000000 {
> > + compatible = "mediatek,secure_cma_chunkmem";
> > + reusable;
> > + reg = <0x80000000 0x18000000>;
> > + };
> > + };
> > --
> > 2.25.1
> >
On 12/09/2023 08:16, Yong Wu (吴勇) wrote:
> Hi Rob,
>
> Thanks for your review.
>
> On Mon, 2023-09-11 at 10:44 -0500, Rob Herring wrote:
>>
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>> On Mon, Sep 11, 2023 at 10:30:37AM +0800, Yong Wu wrote:
>>> This adds the binding for describing a CMA memory for MediaTek
>> SVP(Secure
>>> Video Path).
>>
>> CMA is a Linux thing. How is this related to CMA?
>
>>>
>>> Signed-off-by: Yong Wu <[email protected]>
>>> ---
>>> .../mediatek,secure_cma_chunkmem.yaml | 42
>> +++++++++++++++++++
>>> 1 file changed, 42 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/reserved-
>> memory/mediatek,secure_cma_chunkmem.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/reserved-
>> memory/mediatek,secure_cma_chunkmem.yaml
>> b/Documentation/devicetree/bindings/reserved-
>> memory/mediatek,secure_cma_chunkmem.yaml
>>> new file mode 100644
>>> index 000000000000..cc10e00d35c4
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/reserved-
>> memory/mediatek,secure_cma_chunkmem.yaml
>>> @@ -0,0 +1,42 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$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
>>
>> What makes this specific to Mediatek? Secure video path is fairly
>> common, right?
>
> Here we just reserve a buffer and would like to create a dma-buf secure
> heap for SVP, then the secure engines(Vcodec and DRM) could prepare
> secure buffer through it.
>
> But the heap driver is pure SW driver, it is not platform device and
All drivers are pure SW.
> we don't have a corresponding HW unit for it. Thus I don't think I
> could create a platform dtsi node and use "memory-region" pointer to
> the region. I used RESERVEDMEM_OF_DECLARE currently(The code is in
> [9/9]). Sorry if this is not right.
If this is not for any hardware and you already understand this (since
you cannot use other bindings) then you cannot have custom bindings for
it either.
>
> Then in our usage case, is there some similar method to do this? or
> any other suggestion?
Don't stuff software into DTS.
Best regards,
Krzysztof