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

[Alexandre Mergnat]

Le lun. 23 janv. 2023 à 11:44, Michael Walle <michael@xxxxxxxx> a écrit :
>
> Hi,
>
> Am 2023-01-23 10:37, schrieb Alexandre Mergnat:
> > 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].
> >>
> > Yes I want to expose the SPI on the pin header for two reasons:
>
> Then "mediatek,genio" doesn't really describe the hardware, does it?
> If you read that linked thread, NXP was also trying exposing the SPI
> bus on a pin header. IMHO this is just misusing the userspace spi-dev.
>
> That being said, exposing something on a pinheader (or on a standardized
> connector) seems like a common thing and we should be working towards
> a good solution. I still think Robs proposal for the mikrobus connector
> makes also sense for your case.
>

I don't think this is the same case. For the mikrobus case, it's
consistent to have a connector because it fit with other "add-on"
board which can be plug on the "mother board".
Here I've just a simple debug pin header. I've taken a look at
raspberry pi and Beaglebone black DTS, they don't use connector, but
DTS overlay to enable SPI. I think you're right when you say that I'm
misusing the userspace spi-dev.