diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 38 |
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 |