目录
前言：
调试准备工作：
修改内核默认打印等级
一、imx415驱动开发
1、硬件接线
2、设备树修改
2.1 创建 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi 文件
2.2 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi 添加到设备树
2.3 编译设备树
3、imx415驱动开发
3.1 imx415寄存器
1）mclk 时钟
2）lane数量
3）lane速率
4）分辨率
5）像素深度
6）Master/Slave模式
7）启流、停流相关
8）增益
编辑
9）曝光
编辑
10）All pixel模式 4lane 配置表
3.2 imx415驱动
1）Linux_for_Tegra/source/nvidia-oot/drivers/media/i2c/imx415_mode_tbls.h 源码
2）Linux_for_Tegra/source/nvidia-oot/include/media/imx415.h 源码
3）Linux_for_Tegra/source/nvidia-oot/drivers/media/i2c/nv_imx415.c 驱动文件
4）将 nv_imx415 添加到Makefile
二、编译调试
1、编译imx415驱动
2、安装 v4l-utils 并查看 /dev/video0信息
2.1 安装 v4l-utils
2.2 查看 /dev/video0 信息
3、抓拍
3.1 v4l2-ctl 命令验证vi抓拍
3.2 gstreamer英伟达命令抓拍
1）gst-launch-1.0 自动曝光、自动增益抓拍
2）gst-launch-1.0 设置曝光、增益抓拍
三、imx415驱动开发遇到的问题及解决方法
1、Jetson orin nano开发板的CAM0不支持4lane模式
2、使用 CSI0/1 时，需要将lane_polarity改为 6
3、v4l2-ctl 抓图命令报错
4、v4l2-ctl 抓图不成功，vi能收到数据，但数据不对
5、gstreamer抓图偏红色
四、曝光、增益、格式、焦距对拍照效果的影响
前言：
nvidia相机开发参考链接：相机软件开发解决方案 — NVIDIA Jetson Linux 开发者指南
可加载内核模块 （LKM）其实就是就是编译成ko模块。nvidia将所有模块都放在 nvidia-oot 目录下。参考链接：传感器软件驱动程序编程 — NVIDIA Jetson Linux 开发者指南
说明：博主使用野火的imx415摄像头模块，在 Jetson Orin Nano开发板上开发imx415驱动
调试准备工作：
修改内核默认打印等级
$ vi /etc/sysctl.conf
#
# /etc/sysctl.conf - Configuration file for setting system variables
# See /etc/sysctl.d/ for additional system variables.
# See sysctl.conf (5) for information.
#
#kernel.domainname = example.com
# Uncomment the following to stop low-level messages on console
kernel.printk = 8 8 8 8 #打印等级
###################################################################
# Functions previously found in netbase
#
# Uncomment the next two lines to enable Spoof protection (reverse-path filter)
# Turn on Source Address Verification in all interfaces to
# prevent some spoofing attacks
#net.ipv4.conf.default.rp_filter=1
#net.ipv4.conf.all.rp_filter=1
# Uncomment the next line to enable TCP/IP SYN cookies
# See http://lwn.net/Articles/277146/一、imx415驱动开发
1、硬件接线
imx415模块和 Jetson orin nano开发板的csi接口中间有转接板。2 lane模式下，仅 CSI_D0 P/N 和 CSI_D1 P/N 有数据。我使用的是 4 lane 模式。
硬件接上后，用 i2cdetect 工具探测 I2C通不通。cam_i2cmux挂在i2c3下，因此命令如下：
$ i2cdetect -r -y 2
可以看到 imx415 的设备地址为 0x1a
问题：如何知道 CAM1_I2C 挂在 i2c3下？
查看 Linux_for_Tegra/source/hardware/nvidia/t23x/nv-public/tegra234.dtsi
cam_i2c 为I2C3节点， 因此cam_i2cmux在I2C3节点下
2、设备树修改
设备树增加sensor参考文档：Sensor Software Driver Programming — NVIDIA Jetson Linux Developer Guide
2.1 创建 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi 文件
1）将 Linux_for_Tegra/source/hardware/nvidia/t23x/nv-public/overlay 目录下的 tegra234-p3767-camera-p3768-imx477-C.dts 作为模板拷贝一份 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi
imx415 模块 4 lane差分线接在CSI2上，CSI2对应"serial_c"（CSI0对应serial_a，依此类推），因此命名 "tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi"
2）修改 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi
关键参数计算过程：
-
compatible = "ridgerun,imx415" 要和imx415驱动对应上
-
mclk_khz：imx415模块外接 37.125M晶振，因此 mclk_khz = "37125"
-
4 lane模式：因此 num_lanes = "4"， bus-width = <4>;
-
CSI2：因此 tegra_sinterface = "serial_c"，port-index = <2>
-
分辨率：根据 imx415分辨率设置 "active_w = 3864"，active_h = "2192"
-
pixel_phase：像素格式，pixel_phase = "gbrg"，调试时设置为 "rggb" 导致图像偏红色
-
csi_pixel_bit_depth：像素深度，imx415使用RAW12模式，因此 csi_pixel_bit_depth = "12"
-
pix_clk_hz：imx415 配置 lane频率为 891 Mbps，4lane，像素深度为12bit，pix_clk_hz = 891 Mbps × 4 / 12 = 297000000，我理解只要不小于此值即可。
-
mclk_multiplier ：mclk_multiplier ≥ pix_clk_hz / mclk = 297000000 / 37125000 = 8，因此mclk_multiplier = "8"。从nvidia官方手册可知，
mclk_multiplier必须大于等于pix_clk_hz / mclk，以确保ISP运行得足够快，能够处理来自传感器的数据。
-
增益，查看imx415手册
GAIN_PCG_0计算公式：GAIN_PCG_0 = Gain[dB] x 10 /3
GAIN_PCG_0 范围为 0 - 240d，因此 Gain范围为 0 - 72 [dB]，我这里增益因子配置为 gain_factor = "10" ，Gain范围 0 - 72 [dB] 乘上增益因子，得到 min_gain_val = "0"， max_gain_val = "720"，step为 0.3dB 乘增益因子，因此 step_gain_val = "3"
-
曝光：
曝光参数单位为us，需要根据帧率（30fps）、VMAX（2250）、 SHR0 值范围（8 到 Number oflines per frame - 4），按照下面公式倒推 exposure 最小值、最大值、step，我算得结果图下：
min_exp_time = "15"; /* 单位：us */
max_exp_time = "33214"; /* 单位：us */
step_exp_time = "15"; /* 单位：us */
-
embedded_metadata_height：根据imx415手册来配置为 "1"，如下图
最终 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi 文件内容如下：
设备树描述了 VI（视频输入）、NvCSI 、传感器模块 的端口绑定关系
// SPDX-License-Identifier: GPL-2.0-only
// SPDX-FileCopyrightText: Copyright (c) 2023-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
///dts-v1/;
///plugin/;
#define CAM0_RST TEGRA234_MAIN_GPIO(Q, 6) /* add */
#define CAM0_PWDN TEGRA234_MAIN_GPIO(H, 6)
#define CAM1_PWDN TEGRA234_MAIN_GPIO(AC, 0)
#define CAM_I2C_MUX TEGRA234_AON_GPIO(CC, 3)
#include <dt-bindings/tegra234-p3767-0000-common.h>
/ {
overlay-name = "Camera IMX415-C 4 lane";
jetson-header-name = "Jetson 24pin CSI Connector";
compatible = JETSON_COMPATIBLE_P3768;
/*IMX415 connected on cam0 port */
fragment@0 {
target-path = "/";
__overlay__ {
tegra-capture-vi {
num-channels = <1>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
rbpcv3_imx415_vi_in1: endpoint {
port-index = <2>;
bus-width = <4>;
remote-endpoint = <&rbpcv3_imx415_csi_out1>;
};
};
};
};
tegra-camera-platform {
compatible = "nvidia, tegra-camera-platform";
/**
* Physical settings to calculate max ISO BW
*
* num_csi_lanes = <>;
* Total number of CSI lanes when all cameras are active
*
* max_lane_speed = <>;
* Max lane speed in Kbit/s
*
* min_bits_per_pixel = <>;
* Min bits per pixel
*
* vi_peak_byte_per_pixel = <>;
* Max byte per pixel for the VI ISO case
*
* vi_bw_margin_pct = <>;
* Vi bandwidth margin in percentage
*
* max_pixel_rate = <>;
* Max pixel rate in Kpixel/s for the ISP ISO case
*
* isp_peak_byte_per_pixel = <>;
* Max byte per pixel for the ISP ISO case
*
* isp_bw_margin_pct = <>;
* Isp bandwidth margin in percentage
*/
num_csi_lanes = <4>;
max_lane_speed = <1500000>;
min_bits_per_pixel = <10>;
vi_peak_byte_per_pixel = <2>;
vi_bw_margin_pct = <25>;
max_pixel_rate = <7500000>;
isp_peak_byte_per_pixel = <5>;
isp_bw_margin_pct = <25>;
/**
* The general guideline for naming badge_info contains 3 parts, and is as follows,
* The first part is the camera_board_id for the module; if the module is in a FFD
* platform, then use the platform name for this part.
* The second part contains the position of the module, ex. "rear" or "front".
* The third part contains the last 6 characters of a part number which is found
* in the module's specsheet from the vendor.
*/
modules {
module1 {
badge = "jakku_rear_RBPCV3";
position = "rear";
orientation = "1";
drivernode0 {
pcl_id = "v4l2_sensor";
sysfs-device-tree = "/sys/firmware/devicetree/base/bus@0/cam_i2cmux/i2c@1/rbpcv3_imx415_c@1a";
};
};
};
};
bus@0 {
host1x@13e00000 {
nvcsi@15a00000 {
num-channels = <1>;
#address-cells = <1>;
#size-cells = <0>;
channel@0 {
reg = <0>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
rbpcv3_imx415_csi_in1: endpoint@0 {
port-index = <2>;
bus-width = <4>;
remote-endpoint = <&rbpcv3_imx415_out1>;
};
};
port@1 {
reg = <1>;
rbpcv3_imx415_csi_out1: endpoint@1 {
remote-endpoint = <&rbpcv3_imx415_vi_in1>;
};
};
};
};
};
};
cam_i2cmux {
status = "okay";
compatible = "i2c-mux-gpio";
#address-cells = <1>;
#size-cells = <0>;
mux-gpios = <&gpio_aon CAM_I2C_MUX GPIO_ACTIVE_HIGH>;
i2c-parent = <&cam_i2c>;
i2c@0 {
rbpcv2_imx219_a@10 {
status = "disabled";
};
};
i2c@1 {
status = "okay";
reg = <1>;
#address-cells = <1>;
#size-cells = <0>;
rbpcv2_imx219_c@10 {
status = "disabled";
};
rbpcv3_imx415_c@1a {
reset-gpios = <&gpio CAM1_PWDN GPIO_ACTIVE_HIGH>;
compatible = "ridgerun,imx415";
/* I2C device address */
reg = <0x1a>;
/* V4L2 device node location */
devnode = "video0";
/* Physical dimensions of sensor */
physical_w = "9.3";
physical_h = "4.65";
sensor_model = "imx415";
use_sensor_mode_id = "true";
mode0 { /* IMX415_MODE_3864x2192 */
mclk_khz = "37125"; //"24000";
num_lanes = "4";
tegra_sinterface = "serial_c";
phy_mode = "DPHY";
discontinuous_clk = "no";
dpcm_enable = "false";
cil_settletime = "0"; // 0表示自动校准
lane_polarity = "0";
active_w = "3864";
active_h = "2192";
mode_type = "bayer";
pixel_phase = "gbrg"; //"rggb";
csi_pixel_bit_depth = "12"; //12
readout_orientation = "0"; //90
line_length = "4400"; //0x08CA "11200";
inherent_gain = "1";
mclk_multiplier = "8"; //pix_clk_hz / mclk_khz = 297000000 / 37125000 = 8
pix_clk_hz = "297000000"; //891 Mbps × 4 / 12
gain_factor = "10";
framerate_factor = "1000000";
exposure_factor = "1000000";
min_gain_val = "0"; /* 0dB */
max_gain_val = "720"; /* 72dB */
step_gain_val = "3"; /* 0.3dB step */
default_gain = "10"; /* 1dB */
min_hdr_ratio = "1";
max_hdr_ratio = "1";
min_framerate = "2000000"; /* 2.0 fps */
max_framerate = "60000000"; //"30000000"; /* 30.0 fps */
step_framerate = "1";
default_framerate = "30000000"; /* 30.0 fps */
min_exp_time = "15"; /* us, 1H时间 = line_length / pix_clk_hz */
max_exp_time = "33214"; //"33334"; /* us */
step_exp_time = "15";
default_exp_time = "5000"; /* us */
embedded_metadata_height = "1";
set_mode_delay_ms = "500"; //dongao 等待8帧
};
mode1 { /* IMX415_MODE_3864x2192 */
mclk_khz = "37125"; //"24000";
num_lanes = "4";
tegra_sinterface = "serial_c";
phy_mode = "DPHY";
discontinuous_clk = "no";
dpcm_enable = "false";
cil_settletime = "0"; // 0表示自动校准
lane_polarity = "0";
active_w = "3864";
active_h = "2192";
mode_type = "bayer";
pixel_phase = "gbrg"; //"rggb";
csi_pixel_bit_depth = "12"; //10
readout_orientation = "0"; //90
line_length = "4400"; //0x08CA "11200";
inherent_gain = "1";
mclk_multiplier = "8";
pix_clk_hz = "297000000"; //"356400000";
gain_factor = "10";
framerate_factor = "1000000";
exposure_factor = "1000000";
min_gain_val = "0"; /* 0dB */
max_gain_val = "720"; /* 72dB */
step_gain_val = "3"; /* 0.3dB step */
default_gain = "10"; /* 1dB */
min_hdr_ratio = "1";
max_hdr_ratio = "1";
min_framerate = "2000000"; /* 2.0 fps */
max_framerate = "60000000"; /* 60.0 fps */
step_framerate = "1";
default_framerate = "30000000"; /* 60.0 fps */
min_exp_time = "15"; /* us */
max_exp_time = "33214"; /* us */
step_exp_time = "15";
default_exp_time = "5000"; /* us */
embedded_metadata_height = "1";
};
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
rbpcv3_imx415_out1: endpoint {
port-index = <2>;
bus-width = <4>;
remote-endpoint = <&rbpcv3_imx415_csi_in1>;
};
};
};
};
};
};
gpio@2200000 { //add
camera-control-output-low {
gpio-hog;
output-low;
gpios = <CAM0_RST 0>;
label = "cam0-rst";
};
};
gpio@6000d000 {
camera-control-output-low {
gpio-hog;
output-low;
gpios = <CAM1_PWDN 0 CAM0_PWDN 0>;
label = "cam1-pwdn", "cam0-pwdn";
};
};
};
};
};
};
2.2 tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi 添加到设备树
在 tegra234-p3768-0000+p3767-0000-dynamic.dts 中新增 "#include "tegra234-p3767-camera-p3768-imx415-C-4lane.dtsi""，如下：
// SPDX-License-Identifier: GPL-2.0-only
// SPDX-FileCopyrightText: Copyright (c) 2023-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
/dts-v1/;
/plugin/;
/ {
overlay-name = "Tegra234 p3768-0000+p3767-xxxx Dynamic Overlay";
};
/*
* Include this file last in the device tree. It manages run-time
*
