Camera Porting

This document uses the IMX577 as an example to describe the process of porting a Camera sensor on Rhino Pi A1 Mini (QCS6490 platform), covering hardware configuration, device tree modifications, and driver compilation and configuration.

1. Hardware Configuration

The hardware interfaces involved in Camera porting mainly include three parts:

• Power control (GPIO): Controls sensor power-on and reset
• I2C (CCI): The camera-dedicated I2C bus, used to read and write sensor registers
• CSI: The MIPI CSI interface, used to transmit image data

1.1 Device Tree Configuration

Device tree modifications mainly target root hardware binding: if the hardware is unchanged, no modifications are needed when debugging other sensors later. One hardware interface is configured for one sensor; for example, if there are 2 CSI hardware interfaces, two sensor configs are required. The following uses the configuration of one IMX577 as an example:

&cam_cci0 {                                 // cci bus 0
    /* CAM 0 IMX577 */
    cam_slot0: qcom,cam-sensor0 {
        cell-index = <0>;                   // This ID must not be duplicated; it matches the cameraId in the camx module with the device in the kernel
        compatible = "qcom,cam-sensor";
        csiphy-sd-index = <1>;              // The CSI ID, corresponding to the csi2 hardware interface here
        sensor-position-roll = <0>;
        sensor-position-pitch = <0>;
        sensor-position-yaw = <0>;
        power-domains = <&camcc CAM_CC_TITAN_TOP_GDSC>;
        cam_vio-supply = <&vreg_l18b_1p8>;
        regulator-names = "cam_vio";
        rgltr-cntrl-support;
        rgltr-min-voltage = <0>;
        rgltr-max-voltage = <0>;
        rgltr-load-current = <0>;
        gpio-no-mux = <0>;
        pinctrl-names = "cam_default", "cam_suspend";
        pinctrl-0 = <&cam_sensor_active_rst1>;       // Camera reset pin configuration
        pinctrl-1 = <&cam_sensor_suspend_rst1>;
        gpios = <&tlmm 94 0>, <&tlmm 21 0>;
        gpio-custom1 = <0>;
        gpio-custom2 = <1>;
        gpio-req-tbl-num = <0 1>;
        gpio-req-tbl-flags = <0 0>;
        gpio-req-tbl-label = "CAM_CUSTOM1", "CAM_CUSTOM2";
        cci-master = <CCI_MASTER_0>;        // Each CCI controller has 2 masters (0,1); this corresponds to CCI bus:0 Master:0
        status = "ok";
        clocks = <&camcc CAM_CC_MCLK1_CLK>; // MCLK
        clock-names = "cam_clk";
        clock-cntl-level = "nominal";
        clock-rates = <24000000>;           // MCLK frequency
    };
};

CCI mapping: Each CCI controller has 2 masters (0, 1), which can be determined using the following mapping (and so on for the rest):

CCI	CCI bus	Master
cci0	0	0
cci1	0	1
cci2	1	0
cci3	1	1
cci4	2	0

2. Driver Section

2.1 Compilation

Add the sensor build subdirectory to CMakeLists.txt of chi-cdk-kt:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/CMakeLists.txt

add_subdirectory (${CAMX_CHICDK_SENSOR_PATH}/sensor/cmk_imx577/build/linuxembedded ${CAMX_OUT_PATH}/sensor/cmk_imx577)

Add the XML build configuration:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/oem/qcom/buildbins/build/linuxembedded/binary_yupik/com.qti.sensormodule.cmk_imx577_cam1.cmake

2.2 Mapping

Add the SOC-to-sensor-bin mapping in socid_sensorbin_map.xml:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/oem/qcom/module/socid_sensorbin_map.xml

<socIdInfo>
    <!--SOC ID or list of SOC Ids comma seperated-->
    <socId>QCM6490</socId>
    <binName>cmk_imx577_cam1</binName>
</socIdInfo>

Add the probe list in kodiak_dc.xml:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/oem/qcom/multicamera/chimcxcameraconfig/configs/kodiak/kodiak_dc.xml

<PhysicalDevice name="RearPhysicalCam0" slotId="0" cameraId="0" sensorName="cmk_imx577"/>

2.3 Module Configuration

Configuration file:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/oem/qcom/module/cmk_imx577_module_cam1.xml

<cameraId>0</cameraId>

• <cameraId>: This ID must be consistent with the cell-index of the corresponding hardware configuration in the DTS.
• <chromatixName>kodiak_cmk_imx577</chromatixName>: Configures the tuning (ISP) effect; if not available, copy one from another sensor and modify it.

2.4 Sensor Configuration

Sensor configuration file directory:

layers/meta-qcom-extras/recipes-multimedia/camx/files/chi-cdk-kt/oem/qcom/sensor/cmk_imx577

• cmk_imx577_sensor.cpp: Refer to other sensors and just change the name accordingly.

Key configuration items of cmk_imx577_sensor.xml:

<slaveAddress>0x34</slaveAddress>
<sensorIdRegAddr>0x0016</sensorIdRegAddr>
<sensorId>0x0577</sensorId>
<colorFilterArrangement>BAYER_RGGB</colorFilterArrangement>
<dt>43</dt>
<is3Phase>0</is3Phase>

Configuration item	Value	Description
<slaveAddress>	0x34	8-bit I2C address
<sensorIdRegAddr>	0x0016	Sensor ID register
<sensorId>	0x0577	Sensor ID
powerUpSequence	—	Power-up related configuration; configType corresponds to the GPIO configuration in the kernel DTS
<colorFilterArrangement>	BAYER_RGGB	Actual color format
<dt>	43	Data type
<is3Phase>	0	If it is a C-PHY camera, this value must be set to 1