diff options
Diffstat (limited to 'usbreset.c')
| -rw-r--r-- | usbreset.c | 193 |
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; +} |