基于RK3566做人脸识别，选用了一款双目摄像头，RGB+IR，RGB Sensor为GC2093，IR Sensor为GC2053。MIPI CSI使用split mode，可以同时读取两个Sensor的图像。
注意事项：一些低版本的SDK无法启用双目摄像头，刚开始使用的内核版本为4.19.193一直无法启用，后来换为内核版本为4.19.232 sdk才行。
一、硬件连接
器件I2C总线及地址：
GC2093：I2C2---0x7e（7bit address）;
GC2053：I2C2---0x37（7bit address）;
CSI：
GC2093--->csi2_dphy2(MIPI_CSI_RX_D2-3&MIPI_CSI_RX_CLK1)；
GC2053--->csi2_dphy1(MIPI_CSI_RX_D0-1&MIPI_CSI_RX_CLK0)；
CLK：
GC2093：CLK_OUT1（GPIO4_C0------CIF_CLKOUT）;
GC2053：CLK_OUT0（GPIO4_A7-------CAM_CLKOUT0）；
GPIO：
GC2093 reset-gpios---GPIO0_C0;
GC2093 pwdn-gpios---GPIO0_C1;
GC2053 reset-gpios---GPIO0_C4;
GC2053 pwdn-gpios---GPIO0_C3;
二、内核使能RKCIF驱动
内核中需要选中Rockchip Camera Interface driver
Device Drivers --->
Multimedia support --->
V4L platform devices --->
<*> Rockchip Camera Interface driver
rockchip camera sensor interface work mode (interface works in pingpong mode) --->
rockchip rkcif device dummy buffer choice (rkcif use dummy buffer) --->
注意：很多教程都没讲到这一点，可能所用sdk默认使能了RKCIF驱动。因为我所用的sdk默认关闭了此驱动，导致我花了很多时间查找原因。
三、调试
1、查看启动日志，是否检测到了摄像头并且注册了
[root@RK356X:]# dmesg | grep gc20
[ 1.223226] gc2053 2-0037: driver version: 00.01.01
[ 1.223320] gc2053 2-0037: Failed to get power-gpios
[ 1.223342] gc2053 2-0037: Looking up dovdd-supply from device tree
[ 1.223352] gc2053 2-0037: Looking up dovdd-supply property in node /i2c@fe5b0000/gc2053@37 failed
[ 1.223380] gc2053 2-0037: 2-0037 supply dovdd not found, using dummy regulator
[ 1.223465] gc2053 2-0037: Linked as a consumer to regulator.0
[ 1.223482] gc2053 2-0037: Looking up avdd-supply from device tree
[ 1.223492] gc2053 2-0037: Looking up avdd-supply property in node /i2c@fe5b0000/gc2053@37 failed
[ 1.223507] gc2053 2-0037: 2-0037 supply avdd not found, using dummy regulator
[ 1.223557] gc2053 2-0037: Looking up dvdd-supply from device tree
[ 1.223565] gc2053 2-0037: Looking up dvdd-supply property in node /i2c@fe5b0000/gc2053@37 failed
[ 1.223577] gc2053 2-0037: 2-0037 supply dvdd not found, using dummy regulator
[ 1.223631] gc2053 2-0037: lane_num(2) pixel_rate(118800000)
[ 1.231487] gc2053 2-0037: Detected GC2053 sensor
[ 1.231552] rockchip-csi2-dphy csi2-dphy1: dphy1 matches m00_f_gc2053 2-0037:bus type 4
[ 1.232893] gc2093 2-007e: driver version: 00.01.02
[ 1.233031] gc2093 2-007e: Looking up dovdd-supply from device tree
[ 1.233042] gc2093 2-007e: Looking up dovdd-supply property in node /i2c@fe5b0000/gc2093@7e failed
[ 1.233085] gc2093 2-007e: 2-007e supply dovdd not found, using dummy regulator
[ 1.233202] gc2093 2-007e: Linked as a consumer to regulator.0
[ 1.233223] gc2093 2-007e: Looking up avdd-supply from device tree
[ 1.233233] gc2093 2-007e: Looking up avdd-supply property in node /i2c@fe5b0000/gc2093@7e failed
[ 1.233250] gc2093 2-007e: 2-007e supply avdd not found, using dummy regulator
[ 1.233330] gc2093 2-007e: Looking up dvdd-supply from device tree
[ 1.233343] gc2093 2-007e: Looking up dvdd-supply property in node /i2c@fe5b0000/gc2093@7e failed
[ 1.233359] gc2093 2-007e: 2-007e supply dvdd not found, using dummy regulator
[ 1.241645] gc2093 2-007e: Detected GC2093 sensor
[ 1.241707] rockchip-csi2-dphy csi2-dphy2: dphy2 matches m01_b_gc2093 2-007e:bus type 4
可知检测到了GC2053和GC2093两个摄像头， 并且都注册成功了。
2、查看内核为摄像头在目录/sys/class/video4linux下分配设备信息描述文件
[root@RK356X:/]# grep "" /sys/class/video4linux/v*/name | grep mainpath
/sys/class/video4linux/video14/name:rkisp_mainpath
/sys/class/video4linux/video5/name:rkisp_mainpath
在上层可以用video5和video14打开两个摄像头。
camera_rkisp_test2.sh
#!/bin/bash
#export GST_DEBUG=*:5
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/gstreamer-1.0
gst-launch-1.0 v4l2src device=/dev/video14 ! video/x-raw,format=NV12,width=640,height=480, framerate=30/1 ! waylandsink &
gst-launch-1.0 v4l2src device=/dev/video5 ! video/x-raw,format=NV12,width=640,height=480, framerate=30/1 ! waylandsink &
执行脚本即可看到两个sensor的画面，不过有一个会被遮挡。