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-rw-r--r--usbreset.c193
1 files changed, 193 insertions, 0 deletions
diff --git a/usbreset.c b/usbreset.c
new file mode 100644
index 0000000..68f87cb
--- /dev/null
+++ b/usbreset.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* usbreset -- send a USB port reset to a USB device */
+/* Copyright (c) 2009-2016 Alan Stern */
+/* To build: gcc -o usbreset usbreset.c */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+#include <dirent.h>
+#include <sys/ioctl.h>
+
+#include <linux/usbdevice_fs.h>
+
+
+/* static char *usbfs = NULL; */
+
+struct usbentry {
+ int bus_num;
+ int dev_num;
+ int vendor_id;
+ int product_id;
+ char vendor_name[128];
+ char product_name[128];
+};
+
+static char *sysfs_attr(const char *dev, const char *attr)
+{
+ int fd, len = 0;
+ char path[PATH_MAX];
+ static char buf[129];
+
+ memset(buf, 0, sizeof(buf));
+ snprintf(path, sizeof(path) - 1, "/sys/bus/usb/devices/%s/%s", dev, attr);
+
+ fd = open(path, O_RDONLY);
+ if (fd >= 0) {
+ len = read(fd, buf, sizeof(buf) - 1);
+ close(fd);
+ }
+
+ while (--len > 0 && isspace(buf[len]))
+ buf[len] = 0;
+
+ return (len >= 0) ? buf : NULL;
+}
+
+static struct usbentry *parse_devlist(DIR *d)
+{
+ char *attr;
+ struct dirent *e;
+ static struct usbentry dev;
+
+ do {
+ e = readdir(d);
+
+ if (!e)
+ return NULL;
+ } while (!isdigit(e->d_name[0]) || strchr(e->d_name, ':'));
+
+ memset(&dev, 0, sizeof(dev));
+ dev.vendor_id = -1;
+ dev.product_id = -1;
+
+ attr = sysfs_attr(e->d_name, "busnum");
+ if (attr)
+ dev.bus_num = strtoul(attr, NULL, 10);
+
+ attr = sysfs_attr(e->d_name, "devnum");
+ if (attr)
+ dev.dev_num = strtoul(attr, NULL, 10);
+
+ attr = sysfs_attr(e->d_name, "idVendor");
+ if (attr)
+ dev.vendor_id = strtoul(attr, NULL, 16);
+
+ attr = sysfs_attr(e->d_name, "idProduct");
+ if (attr)
+ dev.product_id = strtoul(attr, NULL, 16);
+
+ attr = sysfs_attr(e->d_name, "manufacturer");
+ if (attr)
+ strcpy(dev.vendor_name, attr);
+
+ attr = sysfs_attr(e->d_name, "product");
+ if (attr)
+ strcpy(dev.product_name, attr);
+
+ if (dev.bus_num && dev.dev_num && dev.vendor_id >= 0 && dev.product_id >= 0)
+ return &dev;
+
+ return NULL;
+}
+
+static void list_devices(void)
+{
+ DIR *devs = opendir("/sys/bus/usb/devices");
+ struct usbentry *dev;
+
+ if (!devs)
+ return;
+
+ while ((dev = parse_devlist(devs)) != NULL)
+ printf(" Number %03d/%03d ID %04x:%04x %s\n",
+ dev->bus_num, dev->dev_num,
+ dev->vendor_id, dev->product_id,
+ dev->product_name);
+
+ closedir(devs);
+}
+
+static struct usbentry *find_device(int *bus, int *dev, int *vid, int *pid,
+ const char *product)
+{
+ DIR *devs = opendir("/sys/bus/usb/devices");
+
+ struct usbentry *e, *match = NULL;
+
+ if (!devs)
+ return NULL;
+
+ while ((e = parse_devlist(devs)) != NULL)
+ if ((bus && (e->bus_num == *bus) && (e->dev_num == *dev)) ||
+ (vid && (e->vendor_id == *vid) && (e->product_id == *pid)) ||
+ (product && !strcasecmp(e->product_name, product))) {
+ match = e;
+ break;
+ }
+
+ closedir(devs);
+
+ return match;
+}
+
+static void reset_device(struct usbentry *dev)
+{
+ int fd;
+ char path[PATH_MAX];
+
+ snprintf(path, sizeof(path) - 1, "/dev/bus/usb/%03d/%03d",
+ dev->bus_num, dev->dev_num);
+
+ printf("Resetting %s ... ", dev->product_name);
+
+ fd = open(path, O_WRONLY);
+ if (fd > -1) {
+ if (ioctl(fd, USBDEVFS_RESET, 0) < 0)
+ printf("failed [%s]\n", strerror(errno));
+ else
+ printf("ok\n");
+
+ close(fd);
+ } else {
+ printf("can't open [%s]\n", strerror(errno));
+ }
+}
+
+
+int main(int argc, char **argv)
+{
+ int id1, id2;
+ struct usbentry *dev;
+
+ if ((argc == 2) && (sscanf(argv[1], "%3d/%3d", &id1, &id2) == 2))
+ dev = find_device(&id1, &id2, NULL, NULL, NULL);
+ else if ((argc == 2) && (sscanf(argv[1], "%4x:%4x", &id1, &id2) == 2))
+ dev = find_device(NULL, NULL, &id1, &id2, NULL);
+ else if ((argc == 2) && strlen(argv[1]) < 128)
+ dev = find_device(NULL, NULL, NULL, NULL, argv[1]);
+ else {
+ printf("Usage:\n"
+ " usbreset PPPP:VVVV - reset by product and vendor id\n"
+ " usbreset BBB/DDD - reset by bus and device number\n"
+ " usbreset \"Product\" - reset by product name\n\n"
+ "Devices:\n");
+ list_devices();
+ return 1;
+ }
+
+ if (!dev) {
+ fprintf(stderr, "No such device found\n");
+ return 1;
+ }
+
+ reset_device(dev);
+ return 0;
+}