Re: [PATCH 06/13] dt-bindings: rng: add bindings for microchip mpfs rng

[<Conor.Dooley@xxxxxxxxxxxxx>]

On 08/11/2021 21:16, Krzysztof Kozlowski wrote:
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> 
> On 08/11/2021 16:05, conor.dooley@xxxxxxxxxxxxx wrote:
>> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>
>> Add device tree bindings for the hardware rng device accessed via
>> the system services on the Microchip PolarFire SoC.
>>
>> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>> ---
>>   .../bindings/rng/microchip,mpfs-rng.yaml      | 31 +++++++++++++++++++
>>   1 file changed, 31 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/rng/microchip,mpfs-rng.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/rng/microchip,mpfs-rng.yaml b/Documentation/devicetree/bindings/rng/microchip,mpfs-rng.yaml
>> new file mode 100644
>> index 000000000000..e8ecb3538a86
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/rng/microchip,mpfs-rng.yaml
>> @@ -0,0 +1,31 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: "http://devicetree.org/schemas/rng/microchip,mpfs-rng.yaml#";
>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
>> +
>> +title: Microchip MPFS random number generator
>> +
>> +maintainers:
>> +  - Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>> +
>> +properties:
>> +  compatible:
>> +    const: microchip,polarfire-soc-rng
>> +
>> +  syscontroller:
>> +    maxItems: 1
>> +    description: name of the system controller device node
> 
> There are several issues with this:
> 1. You need to describe the type.
> 2. Description is not helpful (just copying the name of property) and
> actually misleading because you do not put there the name of device node.
> 3. What is it? Looks like syscon (or sometimes called sysreg). If yes,
> please use existing syscon bindings.
1 & 2 - Correct, it is bad & I'll write a better description for it.
3 - Its a system controller implemented as a mailbox. The syscontroller 
is the mailbox client, which the rng and generic drivers both use.
> 
>> +
>> +required:
>> +  - compatible
>> +  - "syscontroller"
> 
> No need for quotes.
> 
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    hwrandom: hwrandom {
>> +        compatible = "microchip,polarfire-soc-rng";
>> +        syscontroller = <&syscontroller>;
>> +    };
>>
> 
> 
> Best regards,
> Krzysztof
>