Input: introduce EV_MSC Timestamp
Some devices provides the actual timestamp (hid_dg_scan_time in win8 ones)
computed by the hardware itself. This value is global to the frame and is
not specific to the multitouch protocol.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt
index 53305bd..f1ea2c6 100644
--- a/Documentation/input/event-codes.txt
+++ b/Documentation/input/event-codes.txt
@@ -196,6 +196,17 @@
EV_MSC events are used for input and output events that do not fall under other
categories.
+A few EV_MSC codes have special meaning:
+
+* MSC_TIMESTAMP:
+ - Used to report the number of microseconds since the last reset. This event
+ should be coded as an uint32 value, which is allowed to wrap around with
+ no special consequence. It is assumed that the time difference between two
+ consecutive events is reliable on a reasonable time scale (hours).
+ A reset to zero can happen, in which case the time since the last event is
+ unknown. If the device does not provide this information, the driver must
+ not provide it to user space.
+
EV_LED:
----------
EV_LED events are used for input and output to set and query the state of
diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h
index 5588285..935119c 100644
--- a/include/uapi/linux/input.h
+++ b/include/uapi/linux/input.h
@@ -851,6 +851,7 @@
#define MSC_GESTURE 0x02
#define MSC_RAW 0x03
#define MSC_SCAN 0x04
+#define MSC_TIMESTAMP 0x05
#define MSC_MAX 0x07
#define MSC_CNT (MSC_MAX+1)