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Message-ID: <36b1389a-f08c-96df-47d5-e8ca93b9f8ab@gmail.com>
Date:   Mon, 21 Nov 2022 12:29:25 +0100
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Subject: Re: [PATCH dt-schema.git] schemas: add NVMEM cell with
 #nvmem-cell-cells
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     Michael Walle <michael@walle.cc>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>
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 <259ad74e-ec86-34e6-661f-7b7b172c4ddd@linaro.org>
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On 21.11.2022 12:25, Krzysztof Kozlowski wrote:
> On 21/11/2022 11:58, Rafał Miłecki wrote:
>> From: Rafał Miłecki <rafal@milecki.pl>
>>
>> Some NVMEM cells may provide more than 1 value. An example can be base
>> MAC address that is used for calculating multiple MACs (for few
>> different devices). For specifying value to read phandle needs to be
>> used with an argument.
>>
>> Cc: Srinivas Kandagatla" <srinivas.kandagatla@linaro.org>
>> Cc: Michael Walle <michael@walle.cc>
>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>> ---
>> This bit is required for moving forward with the
>> [PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
>> https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/
>>
>> As pointed out by Rob #nvmem-cell-cells should be added to the dt-schema
>> and not a Linux binding:
>> Re: [PATCH v2 15/20] dt-bindings: nvmem: add YAML schema for the sl28 vpd layout
>> https://lore.kernel.org/linux-arm-kernel/20220912192038.GA1661550-robh@kernel.org/
>>
>> sl28 is one example that needs #nvmem-cell-cells
>> u-boot,env is another one
>>
>> Please let me know if I got this binding right at all.
>> ---
>>   dtschema/schemas/nvmem/nvmem-cell.yaml | 23 +++++++++++++++++++++++
>>   1 file changed, 23 insertions(+)
>>   create mode 100644 dtschema/schemas/nvmem/nvmem-cell.yaml
>>
>> diff --git a/dtschema/schemas/nvmem/nvmem-cell.yaml b/dtschema/schemas/nvmem/nvmem-cell.yaml
>> new file mode 100644
>> index 0000000..dfa99b8
>> --- /dev/null
>> +++ b/dtschema/schemas/nvmem/nvmem-cell.yaml
>> @@ -0,0 +1,23 @@
>> +# SPDX-License-Identifier: BSD-2-Clause
>> +$id: "http://devicetree.org/schemas/nvmem/nvmem-cell.yaml#"
>> +$schema: "http://devicetree.org/meta-schemas/base.yaml#"
> 
> Drop quotes from both.
> 
>> +
>> +title: NVMEM Cell Common Properties
>> +description: "Schema for NVMEM cell devicetree bindings"
> 
> Drop quotes.
> 
>> +maintainers:
>> +  - Rafał Miłecki <rafal@milecki.pl>
>> +  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> +
>> +# always select the core schema
>> +select: true
>> +
>> +properties:
>> +  "#nvmem-cell-cells":
>> +    $ref: "/schemas/types.yaml#/definitions/uint32"
> 
> Drop quotes.
> 
> Rest looks fine to me, except a bit funny cell-cell name, but that's
> just life. :)

Bothers me a bit too, I was even thinking about renaming NVMEM cells to
NVMEM entries but I'm not sure if it's not too late for that.

We already have "nvmem-cells" and "nvmem-cell-names" properties so
adding "entries" not would be probably confusing.


>> +    description: >
>> +      Some NVMEM cells may consist of raw data that requires some extra
>> +      processing. They may provide more than 1 value.
>> +
>> +      Passing extra argument(s) allows selecting data to access.
>> +
>> +additionalProperties: true