usbreset.c

/* usbreset -- send a USB port reset to a USB device
 *
 * Compile using: gcc -o usbreset usbreset.c
 *
 *
 * */




#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;
}

armbian 5.65, orange pi zero: ./usbreset /dev/ttyUSB0 Resetting USB device /dev/ttyUSB0 Error in ioctl: Inappropriate ioctl for device

Here is an example. To reset the RTL2838 on USB bus 005, port 002

nanopi-root: lsusb
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 002: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

nanopi-root: ./usbreset /dev/bus/usb/005/002
Resetting USB device /dev/bus/usb/005/002
Reset successful
nanopi-root: