[PATCH 09/10] HID: introduce Scan Time

@@ -174,6 +174,13 @@ A few EV_ABS codes have special meanings:
     the input device may be used freely in three dimensions, consider ABS_Z
     instead.
 
+* ABS_SCAN_TIME:
+  - Used when the device provides a timestamp for each frame. The unit must be
+    100us, and may be reset when the device don't send any events for a
+    period of time. The values increment at each frame and thus, it can roll
+    back to 0 when reach logical_max. If the device does not provide this
+    information, the driver must not provide it to the user space.
+
 * ABS_MT_<name>:
   - Used to describe multitouch input events. Please see
     multi-touch-protocol.txt for details.

@@ -675,6 +675,10 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 			map_key_clear(BTN_STYLUS2);
 			break;
 
+		case 0x56: /* Scan Time */
+			map_abs(ABS_SCAN_TIME);
+			break;
+
 		default:  goto unknown;
 		}
 		break;

@@ -447,19 +447,26 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			mt_store_field(usage, td, hi);
 			td->last_field_index = field->index;
 			return 1;
+		case HID_DG_SCANTIME:
+			hid_map_usage(hi, usage, bit, max,
+				EV_ABS, ABS_SCAN_TIME);
+			set_abs(hi->input, ABS_SCAN_TIME, field, 0);
+			td->last_field_index = field->index;
+			return 1;
 		case HID_DG_CONTACTCOUNT:
 			td->last_field_index = field->index;
 			return 1;
 		case HID_DG_CONTACTMAX:
-			/* we don't set td->last_slot_field as contactcount and
-			 * contact max are global to the report */
+			/* we don't set td->last_slot_field as scan time,
+			 * contactcount and contact max are global to the
+			 * report */
 			td->last_field_index = field->index;
 			return -1;
-		}
 		case HID_DG_TOUCH:
 			/* Legacy devices use TIPSWITCH and not TOUCH.
 			 * Let's just ignore this field. */
 			return -1;
+		}
 		/* let hid-input decide for the others */
 		return 0;
 

@@ -279,6 +279,7 @@ struct hid_item {
 #define HID_DG_DEVICEINDEX	0x000d0053
 #define HID_DG_CONTACTCOUNT	0x000d0054
 #define HID_DG_CONTACTMAX	0x000d0055
+#define HID_DG_SCANTIME		0x000d0056
 
 /*
  * HID report types --- Ouch! HID spec says 1 2 3!

@@ -796,6 +796,7 @@ struct input_keymap_entry {
 #define ABS_TILT_X		0x1a
 #define ABS_TILT_Y		0x1b
 #define ABS_TOOL_WIDTH		0x1c
+#define ABS_SCAN_TIME		0x1d
 
 #define ABS_VOLUME		0x20