Re: [PATCH v3 4/4] arm64: dts: freescale: imx8mp-verdin: Add mezzanine OV5640 overlays

[Ernest Van Hoecke]

On Thu, Oct 22, 2026 at 05:20:48PM -0400, Frank Li wrote:
> On Thu, Oct 22, 2026 at 04:31:28PM +0200, Ernest Van Hoecke wrote:
> > From: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
> >
> > The Verdin iMX8M Plus exposes its second MIPI CSI-2 interface through the
> > Verdin iMX8M Plus Mezzanine. Add overlays for using a Toradex OV5640 camera
> > on this interface.
> >
> > The mezzanine can route the camera control signals through two jumper
> > configurations. Describe each configuration as a GPIO nexus mapping so the
> > camera description remains independent of the physical routing.
> >
> > The default positions share the native CSI_1 GPIOs and are intended for a
> > single camera. The alternate positions permit simultaneous native and
> > mezzanine cameras, but conflict with the Atmel MXT touchscreen GPIO.
> >
> > The current camera set uses a 27 MHz on-board oscillator. The legacy camera
> > module uses 24 MHz, so provide variants for both.
> >
> > Link: https://developer.toradex.com/hardware/verdin-som-family/add-ons/verdin-imx8m-plus-mezzanine/
> > Link: https://developer.toradex.com/hardware/accessories/cameras/csi-camera-module-5mp-ov5640-arducam
> > Link: https://developer.toradex.com/hardware/legacy-products/other/csi-camera-module-5mp-ov5640/
> > Signed-off-by: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
> > ---
> >  arch/arm64/boot/dts/freescale/Makefile             | 19 ++++++
> >  ...-verdin-mezzanine-ov5640-24mhz-alt-jumpers.dtso | 19 ++++++
> >  ...din-mezzanine-ov5640-24mhz-default-jumpers.dtso | 18 +++++
> >  ...imx8mp-verdin-mezzanine-ov5640-alt-jumpers.dtso | 38 +++++++++++
> >  ...mp-verdin-mezzanine-ov5640-default-jumpers.dtso | 42 ++++++++++++
> >  .../freescale/imx8mp-verdin-mezzanine-ov5640.dtsi  | 78 ++++++++++++++++++++++
> 
> why not share with imx8m-verdin-ov5640.dtsi, which is almost the same.
> 
> Frank

Hi Frank,

Both camera modules have their own oscillator, and the native and
Mezzanine connectors have their own supply, so each overlay describes its
own clock and regulator nodes. They also use a different I2C bus, CSI
receiver and connector. Both overlays are applied together for two
cameras (imx8mp-verdin-wifi-dev-dual-ov5640), so their node names and
labels must be unique, and a single .dtsi cannot be included twice.

The connector nexus makes the GPIOs independent of the routing, but an
overlay still has to name the connector, bus and receiver it uses. One
overlay for either connector would need the target to be chosen when it
is applied, which is what the DT connector/addon work is about, so sadly
we have to wait for that to make things more generic.

What is left in common is a few constant sensor properties, so I would
like to keep the two files.

Thanks for your input and best regards,
Ernest