HID: roccat: added sensor sysfs attribute for Savu

The sensor attr can be used to tweak the optical sensor of the Savu.
Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/ABI/testing/sysfs-driver-hid-roccat-savu

@@ -66,3 +66,12 @@ Description:	The mouse can store 5 profiles which can be switched by the
 		The data has to be 3 bytes long.
 		The mouse will reject invalid data.
 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>/sensor
+Date:		July 2012
+Contact:	Stefan Achatz <erazor_de@users.sourceforge.net>
+Description:	The mouse has a Avago ADNS-3090 sensor.
+		This file allows reading and writing of the mouse sensors registers.
+		The data has to be 4 bytes long.
+Users:		http://roccat.sourceforge.net
+

drivers/hid/hid-roccat-savu.c

@@ -121,6 +121,7 @@ SAVU_SYSFS_RW(general, GENERAL)
 SAVU_SYSFS_RW(buttons, BUTTONS)
 SAVU_SYSFS_RW(macro, MACRO)
 SAVU_SYSFS_R(info, INFO)
+SAVU_SYSFS_RW(sensor, SENSOR)
 
 static struct bin_attribute savu_bin_attributes[] = {
 	SAVU_BIN_ATTRIBUTE_W(control, CONTROL),
@@ -129,6 +130,7 @@ static struct bin_attribute savu_bin_attributes[] = {
 	SAVU_BIN_ATTRIBUTE_RW(buttons, BUTTONS),
 	SAVU_BIN_ATTRIBUTE_RW(macro, MACRO),
 	SAVU_BIN_ATTRIBUTE_R(info, INFO),
+	SAVU_BIN_ATTRIBUTE_RW(sensor, SENSOR),
 	__ATTR_NULL
 };
 

drivers/hid/hid-roccat-savu.h

@@ -21,6 +21,7 @@ enum {
 	SAVU_SIZE_BUTTONS = 0x2f,
 	SAVU_SIZE_MACRO = 0x0823,
 	SAVU_SIZE_INFO = 0x08,
+	SAVU_SIZE_SENSOR = 0x04,
 };
 
 enum savu_control_requests {
@@ -35,6 +36,7 @@ enum savu_commands {
 	SAVU_COMMAND_BUTTONS = 0x7,
 	SAVU_COMMAND_MACRO = 0x8,
 	SAVU_COMMAND_INFO = 0x9,
+	SAVU_COMMAND_SENSOR = 0xc,
 };
 
 struct savu_mouse_report_special {