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>

diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 9c8926c..0053ae2 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -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