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authorHans de Goede <hdegoede@redhat.com>2013-08-14 15:34:27 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-14 12:23:09 -0700
commitda9651a5d3d3bdb40e487e6f90f2e092a05f45b4 (patch)
tree6e98bc3e788a9d3e3681b3c74ffa65fd2fcc7243 /Documentation/ABI
parentbb674907111272ca40926ca3d3bad4046fffed52 (diff)
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>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-usb38
1 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 9c8926c5f82..0053ae262a0 100644
--- 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