Re: [PATCH v3 2/2] arm64: dts: qcom: qcs6490-rubikpi3: Add IMX219 camera overlays

Hi Konrad,

Thanks for the review.

On 8/12/26 4:22 AM, Hongyang Zhao wrote:

quoted

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 models the module
power domain controlled through the connector PWR_EN signal. The
baseboard supplies VCC3V3_OUTPUT separately and has no per-camera
regulator.

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.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Hongyang Zhao <redacted>
---

[...]

quoted

+	camera@10 {
+		compatible = "sony,imx219";
+		reg = <0x10>;
+
+		clocks = <&cam1_imx219_clk>;
+
+		VANA-supply = <&vreg_cam1_pwr>;
+		VDIG-supply = <&vreg_cam1_pwr>;
+		VDDL-supply = <&vreg_cam1_pwr>;
+
+		leds = <&cam1_privacy_led>;
+		led-names = "privacy";

No reset GPIOs?

Yes. The RubikPi camera connector does not route a dedicated sensor reset
signal. It exposes PWR_EN and CAMERA_GPIO, but neither is connected
directly to the IMX219 reset input when using the official Raspberry Pi
Camera Module 2.

PWR_EN is connected to the module's ENABLE signal and controls the
module-local power supplies. CAMERA_GPIO corresponds to a pin that is
not connected on Camera Module 2. The IMX219 /PWDN signal remains local
to the camera module and is tied to its 1.8 V rail.

Therefore, there is no board-controllable reset GPIO to describe for
this camera configuration.

You should also have a reference to the mclk pin state to make sure
the correct pin function kicks in

The Camera Module 2 provides its own 24 MHz oscillator, which is
connected to the IMX219 MCLK input on the module. RubikPi does not route
a SoC CAM_MCLK signal to this connector. The fixed-clock node represents
that module-local oscillator, so there is no corresponding TLMM MCLK
pin state.

The Camera Module 2 schematic shows both connections:
https://datasheets.raspberrypi.com/camera/camera-module-2-schematics.pdf

RUBIK Pi 3 schematic (CSI connector, page 13):
https://thundercomm.s3-accelerate.amazonaws.com/uploads/web/rubik-pi-3/RUBIKPI3-IOB-V02-RELEASE.pdf

Best regards,
Hongyang