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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 2 Jul 2020 16:57:15 +0200
Message-ID: <CAMuHMdUkHxOqqX95R5BEET-aSF5SYw2zufnxWuqmKnSY0NENcQ@mail.gmail.com>
Subject: Re: [PATCH] spi: spidev: Add compatible for external SPI ports on
 Kontron boards
To:     Frieder Schrempf <frieder.schrempf@kontron.de>
Cc:     Mark Brown <broonie@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-spi <linux-spi@vger.kernel.org>
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Hi Frieder,

On Thu, Jul 2, 2020 at 4:46 PM Frieder Schrempf
<frieder.schrempf@kontron.de> wrote:
> On 02.07.20 16:25, Mark Brown wrote:
> > On Thu, Jul 02, 2020 at 04:18:46PM +0200, Schrempf Frieder wrote:
> >> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> >>
> >> Allow external SPI ports on Kontron boards to use the spidev driver.
> >
> > I'd have expected this to require loading a DT overlay for whatever's
> > attached?
>
> 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.
>
> See https://patchwork.kernel.org/patch/11639075/ for the boards DT.

You can bind "kontron,user-spi" devices to spidev from userspace:
[PATCH v2 0/3] device tree spidev solution - driver_override for SPI
https://spinics.net/lists/linux-spi/msg13951.html

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds