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Subject: Re: [PATCH] spi: spidev: Add compatible for external SPI ports on
 Kontron boards
To:     Mark Brown <broonie@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org
References: <20200702141846.7752-1-frieder.schrempf@kontron.de>
 <20200702142511.GF4483@sirena.org.uk>
 <24ec4eed-de01-28df-ee1f-f7bcfc80051a@kontron.de>
 <20200702150725.GI4483@sirena.org.uk>
From:   Frieder Schrempf <frieder.schrempf@kontron.de>
Message-ID: <479d566a-213f-4e33-8ac7-7637ae88e31c@kontron.de>
Date:   Thu, 2 Jul 2020 18:24:49 +0200
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On 02.07.20 17:07, Mark Brown wrote:
> On Thu, Jul 02, 2020 at 04:46:09PM +0200, Frieder Schrempf wrote:
> 
>> My intention is to use the spidev driver in the default board DT for an
>> interface that is routed to an extension connector and has no dedicated
>> slave device attached onboard. So users can attach sensors, etc. with
>> userspace drivers without touching the kernel or DT.
> 
> The expected way of doing this is to describe whatever was attached via
> DT when it's attached - the device is what has the compatible, not some
> connector in the middle of the connection.  The way you've got things
> set up if the device has a driver then they won't be able to instantiate
> the driver.

Ok thanks, got it. I will remove the spi device from the board DT and 
use an overlay if required. Now I got a reason to learn writing DT 
overlays ;)