Re: [PATCH 2/2] spi: spidev: add new mediatek support

[Alexandre Mergnat <amergnat@xxxxxxxxxxxx>]

Le ven. 20 janv. 2023 à 09:20, Michael Walle <michael@xxxxxxxx> a écrit :
>
> From: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
>
> > Add the "mediatek,genio" compatible string to support Mediatek
> > SPI controller on the genio boards.
>
> What is the use case of having the spidev? What if I want to
> connect a device with a linux driver to it? It seems like you
> just want to expose the SPI bus on the pin header. There was a
> similar discussion for a mikrobus connector [1].
>

Hi Michael,

Yes I want to expose the SPI on the pin header for two reasons:
- It's an Evaluation Kit board, I believe exposing SPI helps new
customers to try/understand it.
- This board will join the KernelCI soon, this setup will help to do
SPI non regression tests for a fixed default configuration.

AFAII from [1] , you can easily modify the current spidev@0 (If you
don't want to keep userspace interface) or simply add (in the DTS or
overlay) another node foo@1 with a different compatible (and so on)
according to the chip you plug on the header pin.

Regards,
Alex

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/spi/spi-controller.yaml