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Date:   Thu, 21 Apr 2022 13:56:53 +0200
From:   Michael Walle <michael@walle.cc>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     broonie@kernel.org, devicetree@vger.kernel.org,
        jerry.huang@nxp.com, krzysztof.kozlowski+dt@linaro.org,
        leoyang.li@nxp.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
        robh+dt@kernel.org, shawnguo@kernel.org,
        Vladimir Oltean <olteanv@gmail.com>
Subject: Re: [EXT] Re: [PATCH 1/2 v4] dt-bindings: dspi: added for semtech
 sx1301
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 <20220421094421.288672-1-michael@walle.cc>
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Am 2022-04-21 13:08, schrieb Krzysztof Kozlowski:
>> But there *could* be a sane default which then could be replaced in
>> an DT overlay. Like "mirkobus-socket" or similar, which might expose
>> spidev. Actually it is more than just SPI, there is GPIO and resets 
>> and
>> I2C. Maybe it should be an MFD? I don't know. But that is something 
>> for
>> the DT maintainers to decide if they'll allow such "generic" devices.
> 
> I think if you have DT overlay, you can add device node and there is no
> need for placeholder, right?

Yes, that is certainly correct. I was thinking of the user
experience. Sometimes you have eval board with that connector
to tinker around with different modules. Therefore I thought it
would be nice to have an userspace spi device by default for
first steps and tinkering.

There is UART which you can use by just opening the tty. There is
I2C which you can use by the i2ctools. There are GPIOs and PWM
which can also be used either by sysfs or the gpio-utils. But there
is no SPI device which can be used by the spi-tools.

But as I said, that is something up to you to decide :)

-michael