Просмотр кода страницы Usb "отключение включение питания" в Linux

== Linux управление питанием на usb ==

* и так, для начало необходимо собрать или взять ядро с включенным режимом CONFIG_USB_SUSPEND 
* теперь можно "выключать или включать" - на самом деле переводим в режим засыпания или выводим из него, командами:
 #выключаем...
 sh -c "echo suspend > /sys/bus/usb/devices/5-1/power/level"
 #и включаем...
 sh -c "echo auto > /sys/bus/usb/devices/5-1/power/level"
* второй вариант..
 $ echo 0 > /sys/bus/usb/devices/8-1/power/autosuspend
 $ echo auto > /sys/bus/usb/devices/8-1/power/level
 
 Для включения:
 $ echo 2 > /sys/bus/usb/devices/8-1/power/autosuspend
 $ echo on > /sys/bus/usb/devices/8-1/power/level
 
есть еще решение через usbreset:
код на с

  /* usbreset -- send a USB port reset to a USB device */
 
  /*
 
  http://marc.info/?l=linux-usb-users&m=116827193506484&w=2
 
  and needs mounted usbfs filesystem
 
 	  sudo mount -t usbfs none /proc/bus/usb
 
  There is a way to suspend a USB device.  In order to use it,
  you must have a kernel with CONFIG_PM_SYSFS_DEPRECATED turned on.  To
  suspend a device, do (as root):
 
 	  echo -n 2 >/sys/bus/usb/devices/.../power/state
 
  where the "..." is the ID for your device.  To unsuspend, do the same
  thing but with a "0" instead of the "2" above.
 
  Note that this mechanism is slated to be removed from the kernel within
  the next year.  Hopefully some other mechanism will take its place.
 
  > To reset a
  > device?
 
  Here's a program to do it.  You invoke it as either
 
 	  usbreset /proc/bus/usb/BBB/DDD
  or
 	  usbreset /dev/usbB.D
 
  depending on how your system is set up, where BBB and DDD are the bus and
  device address numbers.
 
  Alan Stern
 
  */
 
  #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;
  }
 
создаем файл usbreset.c
собираем командой:
 make usbreset.c -o usbreset

использование:

смотрим устройство lsusb

 # lsusb
  Bus 007 Device 002: ID 0458:003a KYE Systems Corp. (Mouse Systems) NetScroll+ Mini Traveler / Genius NetScroll 120
  Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
  Bus 001 Device 005: ID 5986:0102 Acer, Inc Crystal Eye Webcam
  Bus 001 Device 004: ID 0bda:0158 Realtek Semiconductor Corp. USB 2.0 multicard reader
  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

сбрасываем например мышь:

 # ./usbreset /dev/bus/usb/007/002
  Resetting USB device /dev/bus/usb/007/002
  Reset successful