Re: [PATCH v5 06/20] dt-bindings: memory: introduce DDR4

["Clément Le Goffic" <legoffic.clement@gmail.com>]

Hi Rob,

On 30/07/2025 23:11, Rob Herring wrote:
> On Mon, Jul 28, 2025 at 05:29:37PM +0200, Clément Le Goffic wrote:
>> Introduce JEDEC compliant DDR bindings, that use new memory-props binding.
>>
>> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
>> ---
>>   .../memory-controllers/ddr/jedec,ddr4.yaml         | 34 ++++++++++++++++++++++
>>   1 file changed, 34 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,ddr4.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,ddr4.yaml
>> new file mode 100644
>> index 000000000000..f457066a2f8b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,ddr4.yaml
>> @@ -0,0 +1,34 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,ddr4.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: DDR3 SDRAM compliant to JEDEC JESD79-4D
>> +
>> +maintainers:
>> +  - Krzysztof Kozlowski <krzk@kernel.org>
>> +
>> +allOf:
>> +  - $ref: jedec,sdram-props.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    items:
>> +      - pattern: "^ddr4-[0-9a-f]{2},[0-9a-f]{1}$"
> 
> Shouldn't this be 'jedec,ddr4-...'

That's not the case for lpddr bindings, I wanted both lpddr and ddr 
bindings to be similar but this can change.

> 
>> +      - const: jedec,ddr4
>> +
>> +required:
>> +  - compatible
>> +  - density
>> +  - io-width
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> +  - |
>> +    ddr {
>> +        compatible = "ddr4-ff,f", "jedec,ddr4";
>> +        density = <8192>;
>> +        io-width = <8>;
>> +    };
>>
>> -- 
>> 2.43.0
>>

Best regards,
Clément