Re: [PATCH 3/6] dt-bindings: connector: Add Toradex camera connector

[Frank Li]

On Thu, Sep 10, 2026 at 07:12:05PM +0200, Francesco Dolcini wrote:
> On Thu, Sep 10, 2026 at 12:01:51PM -0500, Frank Li wrote:
> > On Thu, Sep 10, 2026 at 06:39:30PM +0200, Ernest Van Hoecke wrote:
> > > Hi Frank,
> > >
> > > Thanks for reviewing this so quickly.
> > >
> > > On Thu, Sep 10, 2026 at 11:26:22AM -0500, Frank Li wrote:
> > > > On Thu, Sep 10, 2026 at 05:37:59PM +0200, Ernest Van Hoecke wrote:
> > > > > From: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
> > > > >
> > > > > Toradex boards route the sideband signals of their 24-pin camera
> > > > > connectors to different GPIO controllers. Camera overlays which name
> > > > > those controllers directly must therefore be duplicated for each host
> > > > > board.
> > > > >
> > > > > Describe reset, power-down, detection and power-control as
> > > > > connector-local GPIO functions. This lets an accessory overlay remain
> > > > > independent of the host wiring. MIPI CSI-2, I2C, clocks and supplies
> > > > > remain described separately because the GPIO nexus does not abstract
> > > > > them.
> > > > >
> > > > > Signed-off-by: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
> > > > > ---
> > > > >  .../connector/toradex,camera-connector.yaml        | 86 ++++++++++++++++++++++
> > > > >  1 file changed, 86 insertions(+)
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/connector/toradex,camera-connector.yaml b/Documentation/devicetree/bindings/connector/toradex,camera-connector.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..06e6836e1aa6
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/connector/toradex,camera-connector.yaml
> > > > > @@ -0,0 +1,86 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/connector/toradex,camera-connector.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/base.yaml#
> > > > > +
> > > > > +title: Toradex camera connector GPIO nexus
> > > > > +
> > > > > +maintainers:
> > > > > +  - Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
> > > > > +  - Toradex Linux BSP Team <linux-bsp@xxxxxxxxxxx>
> > > > > +
> > > > > +description: |
> > > > > +  Toradex boards provide 24-pin camera connectors carrying MIPI CSI-2, I2C,
> > > > > +  clock, power, and sideband GPIO signals. This binding describes the sideband
> > > > > +  signals as a GPIO nexus. The other connector resources remain described by
> > > > > +  the surrounding board device tree.
> > > > > +
> > > > > +  The nexus exposes connector-local GPIO function numbers to camera overlays
> > > > > +  and maps the functions wired by a carrier board to their GPIO controllers.
> > > > > +  GPIO specifiers contain a function number followed by standard GPIO flags.
> > > > > +  A board may omit functions which it does not wire.
> > > > > +
> > > > > +  The function numbers are:
> > > > > +    - 0: Camera reset, connector pin 11
> > > > > +    - 1: Camera power-down, connector pin 22
> > > > > +    - 2: Camera identification, connector pin 23
> > > > > +    - 3: Camera power control, connector pin 24
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    const: toradex,camera-connector
> > > >
> > > > Name is too generally, suggest use board name, we got similar comments at
> > > >
> > > > https://lore.kernel.org/imx/20260629074734.3643227-2-chancel.liu@xxxxxxxxxxx/
> > >
> > > I saw that and it made me reconsider this name.
> > >
> > > However, I believe that in our case it is specific enough. It is really
> > > the same on all our carrier boards, and Toradex specific. It's also only
> > > for cameras, which is more defined than just "io". Curious to see if
> > > others agree or if we should come up with a name for this.
> >
> > If some days later, you update hardware connector to 30pin from 24pins.
>
> That connector is there since years, not days.
>
> We have multiple cameras, designed to mate with it.
>
> If tomorrow we will define a new camera connector (that is absolutely
> possible), the new connector will get its name, maybe
> toradex,camera-connector-v2, or toradex,camera-connector-22pin or
> whatever that connector would be named, not just in the DT, but also as
> a product and on the actual HW.

You can wait for DT team to comments this.

Frank

>
>
> Francesco
>