Host Driver not registring V4L2 subdevices after bridge

[Eximius]

Hi,

We are using a Parallel to CSI-Mipi converter to attach a Parallel Sensor to the CSI-Mipi interface.

The Bridge driver probes and links successfully. The image sensor probes and makes the async registration successfully, but is not linked or registered as sub-device by the host driver (mx8-img-md).

Related dmesg printouts:

[ 3.412261] mx8-img-md: Registered sensor subdevice: tc358746 1-000e (1)
[ 3.423207] mx8-img-md: created link [mxc_isi.0] => [mxc_isi.0.capture]
[ 3.437288] mx8-img-md: created link [mxc-mipi-csi2.0] => [mxc_isi.0]
[ 3.515797] mx8-img-md: created link [tc358746 1-000e] => [mxc-mipi-csi2.0]

Converter Driver Link

From my DTS:

parallel_sensor: parallel_sensor@22 {
	compatible = "parallel_sensor_d";
	reg = <0x22>;
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_csi0_rst>;
	reset-gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
	port {
		parallel_sensor_out: endpoint {
			bus-type = <5>;
			bus-width = <16>;
			remote-endpoint = <&tc358748_ep0>;
		};
	};
};

tc358748_adapter: tc358748_adapter@e {
	compatible = "toshiba,tc358746";
	reg = <0xE>;
	status = "okay";
	
	clocks = <&clk_serialize>;
	default-input = <0>;
	
	#address-cells = <1>;
	#size-cells = <0>;
	
	port@0 {
		reg = <0>;
		tc358748_ep0: endpoint {
			bus-type = <5>;
			bus-width = <16>;
			remote-endpoint = <&parallel_sensor_out>;
		};
	};
	port@1 {
		reg = <1>;
		tc358748_ep1: endpoint {
			data-lanes = <2>;
			clock-lanes = <1>;
			link-frequencies = /bits/ 64 <216000000>;
			remote-endpoint = <&mipi1_sensor_ep>;
		};
	};
};

 Platform: i.MX 8M Plus Evalboard

My first question is, how can the Parallel Sensor be registered as subdevice by the host driver, so that the link can be set up?

I appreciate any hints and answers.

Thanks in advance,

Ian

[igorpadykov]

Hi Ian

one can look at boundary devices linux releases where tc35874x devices are supported:

https://github.com/boundarydevices/linux-imx6/blob/boundary-imx_5.4.x_2.3.0/arch/arm64/boot/dts/free...

https://wiki.boundarydevices.com/index.php/Nitrogen8M_Plus_SOM

https://boundarydevices.com/hdmi-input-for-i-mx8-boards-via-mipi-csi/

Best regards
igor

[Eximius]

Hi Igor,

Thank you for responding so quick.

I already looked the solutions for HDMI-CSI converters, but they don't seem to be my case. As far as I understand, they don't have to setup links with lower subdevices.

Best regards,

Ian