Re: [PATCH v2 2/2] arm64: dts: qcom: qcs6490-rubikpi3: Add IMX219 camera overlays

[Hongyang Zhao <hongyang.zhao@thundersoft.com>]

Thanks for the review!

On 7/22/26 6:12 PM, Hongyang Zhao wrote:
> > RUBIK Pi 3 ships without camera sensors, and its two connectors support
> > multiple modules. Keep module-specific nodes out of the base board DTS
> > and add per-connector overlays for Raspberry Pi Camera Module V2 IMX219
> > sensors.
> >
> > CAM1 uses CCI1 and CSIPHY1, while CAM2 uses CCI0 and CSIPHY4. Each
> > overlay describes the 24 MHz sensor input clock and the three sensor
> > rails derived from the switched 3.3 V connector supply.
> >
> > Describe each connector CAMERA_GPIO signal as a privacy indicator LED
> > and associate it with the corresponding sensor. This lets the V4L2 core
> > control the LED while the sensor is streaming.
> >
> > Signed-off-by: Hongyang Zhao <hongyang.zhao@thundersoft.com>
> > ---
>
> [...]
>
> > +	/* The module enables its three sensor rails together through PWR_EN. */
> > +	vreg_cam2_pwr: regulator-camera2-pwr {
> > +		compatible = "regulator-fixed";
> > +
> > +		regulator-name = "vreg_camera2_pwr";
> > +		regulator-min-microvolt = <3300000>;
> > +		regulator-max-microvolt = <3300000>;
> > +
> > +		gpio = <&tlmm 58 GPIO_ACTIVE_HIGH>;
>
> Is this (and the other) regulator on the SBC, or on the module (with
> the PWR_EN pin just being an output to the module connector)?

The per-camera power regulation is located on the camera module, not on
the baseboard. The board-level VCC3V3_OUTPUT rail supplies both the
40-pin header and the two camera connectors. On the baseboard, U1500
only level-shifts the PWR_EN signals before routing them to the camera
connectors; there is no dedicated per-camera regulator.

The fixed-regulator node in the module-specific Device Tree overlay
models the camera module's power domain controlled through the
connector's PWR_EN signal.

Hardware Schematic:
https://thundercomm.s3-accelerate.amazonaws.com/uploads/web/rubik-pi-3/RUBIKPI3-IOB-V02-RELEASE.pdf

Thanks,
Hongyang