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Subject: Re: [PATCH v4 3/3] arm64: dts: ti: Add support for Siemens IOT2050
 boards
To:     Nishanth Menon <nm@ti.com>
Cc:     Tero Kristo <kristo@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, Le Jin <le.jin@siemens.com>,
        Bao Cheng Su <baocheng.su@siemens.com>,
        Vignesh Raghavendra <vigneshr@ti.com>
References: <cover.1615369068.git.jan.kiszka@siemens.com>
 <9bff40f434e5298890e5d139cc36cc46a0ca2d76.1615369068.git.jan.kiszka@siemens.com>
 <20210311131754.i5ewls6hgeitcgre@astonish>
 <8d076ff1-cdac-941f-e796-a2e6dba792ab@siemens.com>
 <20210311140056.fzvke3rrg6c2uuoa@uncouth>
 <519ae6b7-35db-1fdd-de1e-e0155e0ca82a@siemens.com>
 <20210311142151.5o54k7kmrnatufcw@target>
From:   Jan Kiszka <jan.kiszka@siemens.com>
Message-ID: <f8c6f598-cb9c-ecd5-0b01-09f171ce7c26@siemens.com>
Date:   Thu, 11 Mar 2021 15:36:09 +0100
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On 11.03.21 15:21, Nishanth Menon wrote:
> On 15:14-20210311, Jan Kiszka wrote:
> 
> [...]
> 
>>>
>>> See [1] compare the compatibles against
>>> Documentation/devicetree/bindings -> I think you should describe what
>>> your hardware really is though.
>>
>> This SPI bus is routed to an Arduino connector. By default, userspace
>> (e.g. mraa) takes ownership and adds the desired logic for what is being
>> connected. We have no idea what shield or other extension the user adds,
>> though.
> 
> overlays look like the right approach for variable systems like these.
> It is not exactly plug and play.. but it does provide a level of
> flexibility that is helpful.

Yes, that's for extensions which have kernel drivers. The default model
here is userspace, though. Will add as a separate patch to our queue for
now.

> 
> [..]
>> The problem here is not simple txt->yml conversion: There is no official
>> binding for spidev yet, just existing users and the driver waiting for them.
>>
> 
> I think we should discuss in the spidev list to get it resolved.
> 
>>> Thanks.. While it might help me personally to get some on my internal
>>> farm, it might be good to get them on kernelci as well on the longer
>>> run.
>>>
>>
>> Will keep that on the radar. I definitely want to get it into the CIP
>> LAVA lab which is testing LTS as well.
> 
> Cool.
> 
>> Are we talking about spidev here? Then let's drop that node, but I do
>> need to know how to describe spidev properly
> 
> yes - the spidev is my problem. can you drop the node and repost? i cant
> locally modify and hope it works.
> 

Done.

>>
>> Or is it about those other warnings coming from your dtsi files, now
>> being surfaced? If you can tell me how to resolve them, I can write patches.
> 
> I will look at the warnings later today.. I dont think they are
> triggered by the board dts.
> 

That was also my interpretation of the results. Some are even just
copies from what you get for the EVM boards.

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux