USB devfs 提供了许多操作USB的方法，包括
usb devfs 方法
#define USBDEVFS_CONTROL _IOWR('U', 0, struct usbdevfs_ctrltransfer)
#define USBDEVFS_CONTROL32 _IOWR('U', 0, struct usbdevfs_ctrltransfer32)
#define USBDEVFS_BULK _IOWR('U', 2, struct usbdevfs_bulktransfer)
#define USBDEVFS_BULK32 _IOWR('U', 2, struct usbdevfs_bulktransfer32)
#define USBDEVFS_RESETEP _IOR('U', 3, unsigned int)
#define USBDEVFS_SETINTERFACE _IOR('U', 4, struct usbdevfs_setinterface)
#define USBDEVFS_SETCONFIGURATION _IOR('U', 5, unsigned int)
#define USBDEVFS_GETDRIVER _IOW('U', 8, struct usbdevfs_getdriver)
#define USBDEVFS_SUBMITURB _IOR('U', 10, struct usbdevfs_urb)
#define USBDEVFS_SUBMITURB32 _IOR('U', 10, struct usbdevfs_urb32)
#define USBDEVFS_DISCARDURB _IO('U', 11)
#define USBDEVFS_REAPURB _IOW('U', 12, void *)
#define USBDEVFS_REAPURB32 _IOW('U', 12, __u32)
#define USBDEVFS_REAPURBNDELAY _IOW('U', 13, void *)
#define USBDEVFS_REAPURBNDELAY32 _IOW('U', 13, __u32)
#define USBDEVFS_DISCSIGNAL _IOR('U', 14, struct usbdevfs_disconnectsignal)
#define USBDEVFS_DISCSIGNAL32 _IOR('U', 14, struct usbdevfs_disconnectsignal32)
#define USBDEVFS_CLAIMINTERFACE _IOR('U', 15, unsigned int)
#define USBDEVFS_RELEASEINTERFACE _IOR('U', 16, unsigned int)
#define USBDEVFS_CONNECTINFO _IOW('U', 17, struct usbdevfs_connectinfo)
#define USBDEVFS_IOCTL _IOWR('U', 18, struct usbdevfs_ioctl)
#define USBDEVFS_IOCTL32 _IOWR('U', 18, struct usbdevfs_ioctl32)
#define USBDEVFS_HUB_PORTINFO _IOR('U', 19, struct usbdevfs_hub_portinfo)
#define USBDEVFS_RESET _IO('U', 20)
#define USBDEVFS_CLEAR_HALT _IOR('U', 21, unsigned int)
#define USBDEVFS_DISCONNECT _IO('U', 22)
#define USBDEVFS_CONNECT _IO('U', 23)
#define USBDEVFS_CLAIM_PORT _IOR('U', 24, unsigned int)
#define USBDEVFS_RELEASE_PORT _IOR('U', 25, unsigned int)
#define USBDEVFS_GET_CAPABILITIES _IOR('U', 26, __u32)
#define USBDEVFS_DISCONNECT_CLAIM _IOR('U', 27, struct usbdevfs_disconnect_claim)
#define USBDEVFS_ALLOC_STREAMS _IOR('U', 28, struct usbdevfs_streams)
#define USBDEVFS_FREE_STREAMS _IOR('U', 29, struct usbdevfs_streams)
#define USBDEVFS_DROP_PRIVILEGES _IOW('U', 30, __u32)
#define USBDEVFS_GET_SPEED _IO('U', 31)
通过这些方法，可以编程操作USB BUS，实现断开、重启等操作。
reset usb
#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];//表示usb的ID
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);// 这里是重启
if (rc < 0) {
perror("Error in ioctl");
return 1;
}
printf("Reset successful\n");
close(fd);
return 0;
}
gcc -o reset reset.c
lsusb 发现Quectel 模组 是 Bus 005 Dev 002 执行命令reset usb bus
sudo ./reset /dev/bus/usb/006/002
ubind 断开usb连接
echo '2-1.6' | sudo tee /sys/bus/usb/drivers/usb/unbind