Re: [PATCH 1/2] dt-bindings: usb: Introduce GPIO-based SBU mux

Rob Herring
2022-08-14T21:01:17Z

On Thu, Aug 11, 2022 at 12:14:48PM +0300, Krzysztof Kozlowski wrote:
> On 10/08/2022 23:47, Bjorn Andersson wrote:
> > Introduce a binding for GPIO-based mux hardware used for connecting,
> > disconnecting and switching orientation of the SBU lines in USB Type-C
> > applications.
> >
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > .../devicetree/bindings/usb/gpio-sbu-mux.yaml | 77 +++++++++++++++++++
> > 1 file changed, 77 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml b/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
> > new file mode 100644
> > index 000000000000..7d8aca40c7ca
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
> > @@ -0,0 +1,77 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: "http://devicetree.org/schemas/usb/gpio-sbu-mux.yaml#"
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +
> > +title: GPIO-based SBU mux
> > +
> > +maintainers:
> > + - Bjorn Andersson <bjorn.andersson@linaro.org>
> > +
> > +description:
> > + In USB Type-C applications the SBU lines needs to be connected, disconnected
> > + and swapped depending on the altmode and orientation. This binding describes
> > + a family of hardware which perform this based on GPIO controls.
>
> +Cc few folks.
>
> This looks familiar to:
>
> https://lore.kernel.org/linux-devicetree/eaf2fda8-0cd6-b518-10cb-4e21b5f8c909@linaro.org/T/#m39254b7f8970b3e1264f9d1a979557bb46ab162c
>
> Rob and Stephen had several concerns about that approach.

My overall concern is a bunch of one-off bindings with no one thinking
about a variety of USB-C h/w. I need h/w diagrams and corresponding
bindings. The key part being more than 1. I'm not all that familiar with
the former to help on the bindings.

Rob