USB: Add optional match for interface class to dynamic ID facility

When adding the ID of a composite device dynamically to a driver, all
hitherto unbound interfaces are bound to this driver regardless of their
class, which may not be intended.
The patch adds the option to tell the targeted interface class to a driver
via the "new_id" attribute, in addition to the device ID.
Also, it appends the ABI documentation accordingly.

Example:
$ echo "1234 2a2a ff" >/sys/bus/usb-serial/drivers/option1/new_id
will bind only vendor-specific interfaces to the 3G driver.

Signed-off-by: Josua Dietze <digidietze@draisberghof.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index e647378e9e88..b4f548792e32 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -119,6 +119,31 @@ Description:
                 Write a 1 to force the device to disconnect
                 (equivalent to unplugging a wired USB device).
 
+What:           /sys/bus/usb/drivers/.../new_id
+Date:           October 2011
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Writing a device ID to this file will attempt to
+                dynamically add a new device ID to a USB device driver.
+                This may allow the driver to support more hardware than
+                was included in the driver's static device ID support
+                table at compile time. The format for the device ID is:
+                idVendor idProduct bInterfaceClass.
+                The vendor ID and device ID fields are required, the
+                interface class is optional.
+                Upon successfully adding an ID, the driver will probe
+                for the device and attempt to bind to it.  For example:
+                # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
+
+What:           /sys/bus/usb-serial/drivers/.../new_id
+Date:           October 2011
+Contact:        linux-usb@vger.kernel.org
+Description:
+                For serial USB drivers, this attribute appears under the
+                extra bus folder "usb-serial" in sysfs; apart from that
+                difference, all descriptions from the entry
+                "/sys/bus/usb/drivers/.../new_id" apply.
+
 What:           /sys/bus/usb/drivers/.../remove_id
 Date:           November 2009
 Contact:        CHENG Renquan <rqcheng@smu.edu.sg>