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Message-ID: <c285332f-dde9-2e71-8637-0526c4baeb1e@linaro.org>
Date:   Wed, 6 Jul 2022 20:16:52 +0200
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Subject: Re: [PATCH v2 1/2] [RFT] dt-bindings: leds: Add
 cznic,turris1x-leds.yaml binding
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To:     =?UTF-8?Q?Marek_Beh=c3=ban?= <kabel@kernel.org>
Cc:     =?UTF-8?Q?Pali_Roh=c3=a1r?= <pali@kernel.org>,
        Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220705000448.14337-1-pali@kernel.org>
 <20220705155929.25565-1-pali@kernel.org> <20220706131507.353f0bed@thinkpad>
 <20220706111912.hz2mx4dc35lgq6l5@pali> <20220706172732.6228d180@thinkpad>
 <25b43586-eeb3-4b7b-7362-2d599aa89cf0@linaro.org>
 <20220706184301.3f42a692@thinkpad>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220706184301.3f42a692@thinkpad>
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On 06/07/2022 18:43, Marek Behún wrote:
> On Wed, 6 Jul 2022 17:36:43 +0200
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
>> On 06/07/2022 17:27, Marek Behún wrote:
>>> On Wed, 6 Jul 2022 13:19:12 +0200
>>> Pali Rohár <pali@kernel.org> wrote:
>>>   
>>>> On Wednesday 06 July 2022 13:15:07 Marek Behún wrote:  
>>>>> On Tue,  5 Jul 2022 17:59:28 +0200
>>>>> Pali Rohár <pali@kernel.org> wrote:
>>>>>     
>>>>>> +examples:
>>>>>> +  - |
>>>>>> +    #include <dt-bindings/leds/common.h>
>>>>>> +
>>>>>> +    cpld@3,0 {    
>>>>>
>>>>> The generic node name should be just "bus". That it is a CPLD
>>>>> implementation should come from compatible string.    
>>>>
>>>> Sorry, I do not understand why "bus". Why other memory chips are named
>>>> e.g. "nand" or "nor" and not "bus" too?  
>>>
>>> As far as I understand this is because that is the preferred name for
>>> busses and this is a bus, since there is also the simple-bus compatible.
>>>   
>>>> By this logic should not be _every_ node called just "bus"? Hm... and 
>>>> are names needed at all then?  
>>>
>>> :-)
>>>
>>> The schema
>>>   https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/simple-bus.yaml
>>> allows for different names (soc|axi|ahb|*-bus) to avoid warnings on
>>> existing old dts files.
>>>
>>> The preferred way is to not have the implementation in nodename,
>>> similar to how we use 'switch' instead of 'mv88e6xxx', or
>>> 'ethernet-phy' instead of 'mv88e151x', or 'led-controller', ...  
>>
>> Thanks Marek for detailed explanation.
>> The cases above rather trigger my comments and this one here, after
>> Pali's explanation, do not fit them. pld is a generic class of a device,
>> so it is okay here. cpld probably as well (although one could argue that
>> it is a subset of pld, so the generic name is pld, but then one would
>> say fpga also should be called pld). For me it does not have to be bus,
>> just don't want mv88e6xxx or any other vendor/model names. Therefore
>> cpld is fine.
> 
> What about cpld-bus? It is used as a bus (simple-bus compatible) and
> would work with the *-bus pattern in dt-schema.

If we talk about the example - it does not use any compatible, so we are
focusing on unimportant piece. Anyway using a simple-bus compatible does
not necessarily mean it is a bus. "soc" nodes also use it, but these are
not buses.


Best regards,
Krzysztof