HID: magicmouse: Set resolution of touch surfaces

Add touch surface resolution information. The size of the touch surfaces
has been determined to the hundredth of a mm.

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Michael Poole <mdpoole@troilus.org>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
[jkosina@suse.cz: update comments and commit message]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-magicmouse.c

@@ -81,6 +81,28 @@ MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state fie
 #define NO_TOUCHES -1
 #define SINGLE_TOUCH_UP -2
 
+/* Touch surface information. Dimension is in hundredths of a mm, min and max
+ * are in units. */
+#define MOUSE_DIMENSION_X (float)9056
+#define MOUSE_MIN_X -1100
+#define MOUSE_MAX_X 1258
+#define MOUSE_RES_X ((MOUSE_MAX_X - MOUSE_MIN_X) / (MOUSE_DIMENSION_X / 100))
+#define MOUSE_DIMENSION_Y (float)5152
+#define MOUSE_MIN_Y -1589
+#define MOUSE_MAX_Y 2047
+#define MOUSE_RES_Y ((MOUSE_MAX_Y - MOUSE_MIN_Y) / (MOUSE_DIMENSION_Y / 100))
+
+#define TRACKPAD_DIMENSION_X (float)13000
+#define TRACKPAD_MIN_X -2909
+#define TRACKPAD_MAX_X 3167
+#define TRACKPAD_RES_X \
+	((TRACKPAD_MAX_X - TRACKPAD_MIN_X) / (TRACKPAD_DIMENSION_X / 100))
+#define TRACKPAD_DIMENSION_Y (float)11000
+#define TRACKPAD_MIN_Y -2456
+#define TRACKPAD_MAX_Y 2565
+#define TRACKPAD_RES_Y \
+	((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))
+
 /**
  * struct magicmouse_sc - Tracks Magic Mouse-specific data.
  * @input: Input device through which we report events.
@@ -406,17 +428,31 @@ static void magicmouse_setup_input(struct input_dev *input, struct hid_device *h
 		 * inverse of the reported Y.
 		 */
 		if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
-			input_set_abs_params(input, ABS_MT_POSITION_X, -1100,
-				1358, 4, 0);
-			input_set_abs_params(input, ABS_MT_POSITION_Y, -1589,
-				2047, 4, 0);
+			input_set_abs_params(input, ABS_MT_POSITION_X,
+				MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
+			input_set_abs_params(input, ABS_MT_POSITION_Y,
+				MOUSE_MIN_Y, MOUSE_MAX_Y, 4, 0);
+
+			input_abs_set_res(input, ABS_MT_POSITION_X,
+				MOUSE_RES_X);
+			input_abs_set_res(input, ABS_MT_POSITION_Y,
+				MOUSE_RES_Y);
 		} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
-			input_set_abs_params(input, ABS_X, -2909, 3167, 4, 0);
-			input_set_abs_params(input, ABS_Y, -2456, 2565, 4, 0);
-			input_set_abs_params(input, ABS_MT_POSITION_X, -2909,
-				3167, 4, 0);
-			input_set_abs_params(input, ABS_MT_POSITION_Y, -2456,
-				2565, 4, 0);
+			input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
+				TRACKPAD_MAX_X, 4, 0);
+			input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
+				TRACKPAD_MAX_Y, 4, 0);
+			input_set_abs_params(input, ABS_MT_POSITION_X,
+				TRACKPAD_MIN_X, TRACKPAD_MAX_X, 4, 0);
+			input_set_abs_params(input, ABS_MT_POSITION_Y,
+				TRACKPAD_MIN_Y, TRACKPAD_MAX_Y, 4, 0);
+
+			input_abs_set_res(input, ABS_X, TRACKPAD_RES_X);
+			input_abs_set_res(input, ABS_Y, TRACKPAD_RES_Y);
+			input_abs_set_res(input, ABS_MT_POSITION_X,
+				TRACKPAD_RES_X);
+			input_abs_set_res(input, ABS_MT_POSITION_Y,
+				TRACKPAD_RES_Y);
 		}
 
 		input_set_events_per_packet(input, 60);