Re: [PATCH v3 1/3] dt-bindings: remoteproc: k3-m4f: Add bindings for K3 AM64x SoCs

Krzysztof Kozlowski
2023-03-08T08:42:06Z

On 07/03/2023 19:26, Martyn Welch wrote:
> On Fri, 2023-03-03 at 09:06 +0100, Krzysztof Kozlowski wrote:
>> On 02/03/2023 18:14, Martyn Welch wrote:
>>
>>> +
>>> +  mboxes:
>>> +    description: |
>>> +      OMAP Mailbox specifier denoting the sub-mailbox, to be used
>>> for
>>
>> OMAP?
>>
>
> This device uses a mailbox compatible with the OMAP Mailbox, as defined
> in Documentation/devicetree/bindings/mailbox/ti,omap-mailbox.yaml.
>
> I note that documents title reads "TI OMAP2+ and K3 Mailbox devices".
> I'll drop the "OMAP" here.
>
>>> +      communication with the remote processor. This property
>>> should match
>>> +      with the sub-mailbox node used in the firmware image.
>>> +    maxItems: 1
>>> +
>>> +  memory-region:
>>> +    description: |
>>> +      phandle to the reserved memory nodes to be associated with
>>> the
>>> +      remoteproc device. There should be at least two reserved
>>> memory nodes
>>> +      defined.
>>
>> Don't repeat constraints in free form text.
>>
>>> The reserved memory nodes should be carveout nodes, and
>>> +      should be defined with a "no-map" property as per the
>>> bindings in
>>> +      Documentation/devicetree/bindings/reserved-memory/reserved-
>>> memory.yaml
>>> +    minItems: 2
>>> +    maxItems: 8
>>> +    items:
>>> +      - description: region used for dynamic DMA allocations like
>>> vrings and
>>> +                     vring buffers
>>> +      - description: region reserved for firmware image sections
>>> +    additionalItems: true
>>
>> And what is the purpose of the rest of reserved nodes?
>>
>
> Up to 8 regions can be specified with their purpose determined by the
> firmware running on the M4F core. The suggestion (and the
> implementation in the example firmware) is to use the first 2 regions
> as defined above for remoteproc with the others available to be used
> for other purposes if necessary. The address translation module used
> can cope with up to 8 regions.

Then mention the rest is just dedicated to the firmware and it's purpose
depends on the firmware.

Best regards,
Krzysztof