/[scripts]/trunk/usbreset.c
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Contents of /trunk/usbreset.c

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Revision 137 - (show annotations)
Mon Sep 13 16:36:31 2010 UTC (12 years, 2 months ago) by dpavlin
File MIME type: text/plain
File size: 1547 byte(s)
mount usbfs
1 /* usbreset -- send a USB port reset to a USB device */
2
3 /*
4
5 http://marc.info/?l=linux-usb-users&m=116827193506484&w=2
6
7 and needs mounted usbfs filesystem
8
9 sudo mount -t usbfs none /proc/bus/usb
10
11 There is a way to suspend a USB device. In order to use it,
12 you must have a kernel with CONFIG_PM_SYSFS_DEPRECATED turned on. To
13 suspend a device, do (as root):
14
15 echo -n 2 >/sys/bus/usb/devices/.../power/state
16
17 where the "..." is the ID for your device. To unsuspend, do the same
18 thing but with a "0" instead of the "2" above.
19
20 Note that this mechanism is slated to be removed from the kernel within
21 the next year. Hopefully some other mechanism will take its place.
22
23 > To reset a
24 > device?
25
26 Here's a program to do it. You invoke it as either
27
28 usbreset /proc/bus/usb/BBB/DDD
29 or
30 usbreset /dev/usbB.D
31
32 depending on how your system is set up, where BBB and DDD are the bus and
33 device address numbers.
34
35 Alan Stern
36
37 */
38
39 #include <stdio.h>
40 #include <unistd.h>
41 #include <fcntl.h>
42 #include <errno.h>
43 #include <sys/ioctl.h>
44
45 #include <linux/usbdevice_fs.h>
46
47
48 int main(int argc, char **argv)
49 {
50 const char *filename;
51 int fd;
52 int rc;
53
54 if (argc != 2) {
55 fprintf(stderr, "Usage: usbreset device-filename\n");
56 return 1;
57 }
58 filename = argv[1];
59
60 fd = open(filename, O_WRONLY);
61 if (fd < 0) {
62 perror("Error opening output file");
63 return 1;
64 }
65
66 printf("Resetting USB device %s\n", filename);
67 rc = ioctl(fd, USBDEVFS_RESET, 0);
68 if (rc < 0) {
69 perror("Error in ioctl");
70 return 1;
71 }
72 printf("Reset successful\n");
73
74 close(fd);
75 return 0;
76 }

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