Re: [RFC PATCH 2/3] dt-bindings: gpio: Add binding documentation for Etron EJ168/EJ188/EJ198

From: Linus Walleij
Date: Thu Oct 29 2020 - 13:11:51 EST


On Fri, Oct 16, 2020 at 10:52 PM Martin Blumenstingl
<martin.blumenstingl@xxxxxxxxxxxxxx> wrote:
> On Wed, Oct 14, 2020 at 2:43 PM Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> > On Tue, Oct 13, 2020 at 8:27 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:

> > > I do not understand why a PCI device would need a DT binding
> > > at all. They just probe from the magic number in the PCI
> > > config space, they spawn struct pci_dev PCI devices, not the
> > > type of platform devices coming out of the DT parser code.
> > > No DT compatible needed.
> >
> > Same reason for all the discoverable buses need bindings. There can be
> > parts that are not discoverable or connections with non-discoverable
> > nodes. There's also cases where the discoverable device has to be
> > powered, reset deasserted, clocks enabled, etc. first to be
> > discovered.
> >
> > If the GPIOs here had connections elsewhere in the DT, then we have to
> > describe the provider in DT.
>
> this is exactly what I need it for: that platform has hand-written
> .dts files and I need to wire up a GPIO LED

Aha I get it! OK then :)

Yours,
Linus Walleij