Re: [PATCH v4 2/3] dt-bindings: mailbox: Add thead,th1520-mailbox bindings

[Krzysztof Kozlowski <krzk@kernel.org>]

On 16/10/2024 01:14, Samuel Holland wrote:
>> +  reg-names:
>> +    items:
>> +      - const: local
>> +      - const: remote-icu0
>> +      - const: remote-icu1
>> +      - const: remote-icu2
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  '#mbox-cells':
>> +    const: 2
>> +    description: |
>> +      Specifies the number of cells needed to encode the mailbox specifier.
>> +      The mailbox specifier consists of two cells:
>> +        - Destination CPU ID.
>> +        - Type, which can be one of the following:
>> +            - 0:
>> +                - TX & RX channels share the same channel.
>> +                - Equipped with 7 info registers to facilitate data sharing.
>> +                - Supports IRQ for signaling.
>> +            - 1:
>> +                - TX & RX operate as doorbell channels.
>> +                - Does not have dedicated info registers.
>> +                - Lacks ACK support.
> 
> It appears that these types are not describing hardware, but the protocol used
> by the Linux driver to glue two unidirectional hardware channels together to
> make a virtual bidirectional channel. This is really the responsibility of the
> mailbox client to know what protocol it needs, not the devicetree.
> 

Hm, where is the DTS with consumers of this mailbox provider?

Best regards,
Krzysztof