树莓派/debian12/linux将相同设备id、多端口的设备绑定为固定设备

先展示效果:

[root@raspberrypi ~ 18:24:20]$ls -l /dev/ttyU*
crw-rw---- 1 root dialout 188, 0 Sep 17 18:15 /dev/ttyUSB0
crw-rw---- 1 root dialout 188, 1 Sep 17 18:15 /dev/ttyUSB1
crw-rw---- 1 root dialout 188, 2 Sep 17 18:15 /dev/ttyUSB2
crw-rw---- 1 root dialout 188, 3 Sep 17 18:15 /dev/ttyUSB3
crw-rw---- 1 root dialout 188, 4 Sep 17 18:15 /dev/ttyUSB4
crw-rw---- 1 root dialout 188, 5 Sep 17 18:15 /dev/ttyUSB5
crw-rw---- 1 root dialout 188, 6 Sep 17 18:15 /dev/ttyUSB6
crw-rw---- 1 root dialout 188, 7 Sep 17 18:15 /dev/ttyUSB7
lrwxrwxrwx 1 root root         7 Sep 17 18:15 /dev/ttyUSBEC20M1 -> ttyUSB6
lrwxrwxrwx 1 root root         7 Sep 17 18:15 /dev/ttyUSBEC20M2 -> ttyUSB2

过程

创建文件 /etc/udev/rules.d/99-ec20.rules

# 预先设置一个环境变量接口编号 https://stackoverflow.com/questions/19174482/udev-rule-with-binterfacenumber-doesnt-work
SUBSYSTEMS=="usb", ENV{ID_USB_INTERFACE_NUM}="$attr{bInterfaceNumber}"
# 设备路径需要替换为自己的 使用命令查看 udevadm info -a -p $(udevadm info -q path -n /dev/ttyUSB2)
KERNEL=="ttyUSB[0-9]*",ENV{ID_USB_INTERFACE_NUM}=="02",KERNELS=="1-1.3",ATTRS{devpath}=="1.3",ATTRS{idVendor}=="2c7c",ATTRS{idProduct}=="0125",SYMLINK+="ttyUSBEC20M1"
KERNEL=="ttyUSB[0-9]*",ENV{ID_USB_INTERFACE_NUM}=="02",KERNELS=="1-1.4",ATTRS{devpath}=="1.4",ATTRS{idVendor}=="2c7c",ATTRS{idProduct}=="0125",SYMLINK+="ttyUSBEC20M2"

重启服务后，热插拔设备即可

udevadm control --reload && systemctl restart udev && ./usbreset /dev/bus/usb/001/025 && ./usbreset /dev/bus/usb/001/026

附: usbreset 小工具, 将以下内容保存为usbreset.c
(原文: https://blog.csdn.net/w356877795/article/details/120800766)

/* usbreset -- send a USB port reset to a USB device */
 
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
 
#include <linux/usbdevice_fs.h>
 
 
int main(int argc, char **argv)
{
    const char *filename;
    int fd;
    int rc;
 
    if (argc != 2) {
        fprintf(stderr, "Usage: usbreset device-filename\n");
        return 1;
    }
    filename = argv[1];
 
    fd = open(filename, O_WRONLY);
    if (fd < 0) {
        perror("Error opening output file");
        return 1;
    }
 
    printf("Resetting USB device %s\n", filename);
    rc = ioctl(fd, USBDEVFS_RESET, 0);
    if (rc < 0) {
        perror("Error in ioctl");
        return 1;
    }
    printf("Reset successful\n");
 
    close(fd);
    return 0;
}

编译并赋予权限

gcc usbreset.c -o usbreset && chmod +x ./usbreset

指定设备总线和设备id即可发送重启设备

# lsusb 
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 025: ID 2c7c:0125 Quectel Wireless Solutions Co., Ltd. EC25 LTE modem
Bus 001 Device 026: ID 2c7c:0125 Quectel Wireless Solutions Co., Ltd. EC25 LTE modem
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

./usbreset /dev/bus/usb/001/025 # 重启指定设备

Q.E.D.