Documentation sysfs-bus-usb: Document all files used by libusb
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
bb67490711
commit
da9651a5d3
|
@ -263,3 +263,41 @@ Description:
|
|||
Supported values are 0 - 15.
|
||||
More information on how besl values map to microseconds can be found in
|
||||
USB 2.0 ECN Errata for Link Power Management, section 4.10)
|
||||
|
||||
What: /sys/bus/usb/devices/.../devnum
|
||||
KernelVersion: since at least 2.6.18
|
||||
Description:
|
||||
Device address on the USB bus.
|
||||
|
||||
What: /sys/bus/usb/devices/.../bConfigurationValue
|
||||
KernelVersion: since at least 2.6.18
|
||||
Description:
|
||||
bConfigurationValue of the *active* configuration for the
|
||||
device. Writing 0 or -1 to bConfigurationValue will reset the
|
||||
active configuration (unconfigure the device). Writing
|
||||
another value will change the active configuration.
|
||||
|
||||
Note that some devices, in violation of the USB spec, have a
|
||||
configuration with a value equal to 0. Writing 0 to
|
||||
bConfigurationValue for these devices will install that
|
||||
configuration, rather then unconfigure the device.
|
||||
|
||||
Writing -1 will always unconfigure the device.
|
||||
|
||||
What: /sys/bus/usb/devices/.../busnum
|
||||
KernelVersion: 2.6.22
|
||||
Description:
|
||||
Bus-number of the USB-bus the device is connected to.
|
||||
|
||||
What: /sys/bus/usb/devices/.../descriptors
|
||||
KernelVersion: 2.6.26
|
||||
Description:
|
||||
Binary file containing cached descriptors of the device. The
|
||||
binary data consists of the device descriptor followed by the
|
||||
descriptors for each configuration of the device.
|
||||
Note that the wTotalLength of the config descriptors can not
|
||||
be trusted, as the device may have a smaller config descriptor
|
||||
than it advertises. The bLength field of each (sub) descriptor
|
||||
can be trusted, and can be used to seek forward one (sub)
|
||||
descriptor at a time until the next config descriptor is found.
|
||||
All descriptors read from this file are in bus-endian format
|
||||
|
|
Loading…
Reference in a new issue