HID: roccat: add support for Roccat Savu

This patch adds rupport for Roccat Savu gaming mouse.

In comparison to the other Roccat modules I tried to move even more
functionality to userland.

Userland tools can soon be found at http://sourceforge.net/projects/roccat

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/ABI/testing/sysfs-driver-hid-roccat-savu b/Documentation/ABI/testing/sysfs-driver-hid-roccat-savu
new file mode 100644
index 0000000..e233490
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-hid-roccat-savu
@@ -0,0 +1,68 @@
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/buttons
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	The mouse can store 5 profiles which can be switched by the
+		press of a button. A profile is split into general settings and
+		button settings. buttons holds informations about button layout.
+		When written, this file lets one write the respective profile
+		buttons to the mouse. The data has to be 47 bytes long.
+		The mouse will reject invalid data.
+		Which profile to write is determined by the profile number
+		contained in the data.
+		Before reading this file, control has to be written to select
+		which profile to read.
+Users:		http://roccat.sourceforge.net
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/control
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	When written, this file lets one select which data from which
+		profile will be	read next. The data has to be 3 bytes long.
+		This file is writeonly.
+Users:		http://roccat.sourceforge.net
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/general
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	The mouse can store 5 profiles which can be switched by the
+		press of a button. A profile is split into general settings and
+		button settings. profile holds informations like resolution, sensitivity
+		and light effects.
+		When written, this file lets one write the respective profile
+		settings back to the mouse. The data has to be 43 bytes long.
+		The mouse will reject invalid data.
+		Which profile to write is determined by the profile number
+		contained in the data.
+		This file is writeonly.
+Users:		http://roccat.sourceforge.net
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/info
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	When read, this file returns general data like firmware version.
+		The data is 8 bytes long.
+		This file is readonly.
+Users:		http://roccat.sourceforge.net
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/macro
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	When written, this file lets one store macros with max 500
+		keystrokes for a specific button for a specific profile.
+		Button and profile numbers are included in written data.
+		The data has to be 2083 bytes long.
+		Before reading this file, control has to be written to select
+		which profile and key to read.
+Users:		http://roccat.sourceforge.net
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/savu/roccatsavu<minor>/profile
+Date:		Mai 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	The mouse can store 5 profiles which can be switched by the
+		press of a button. profile holds number of actual profile.
+		This value is persistent, so its value determines the profile
+		that's active when the mouse is powered on next time.
+		When written, the mouse activates the set profile immediately.
+		The data has to be 3 bytes long.
+		The mouse will reject invalid data.
+Users:		http://roccat.sourceforge.net