input: mt: Move tracking and pointer emulation to input-mt

The drivers using the type B protocol all report tracking information
the same way. The contact id is semantically equivalent to
ABS_MT_SLOT, and the handling of ABS_MT_TRACKING_ID only complicates
the driver. The situation can be improved upon by providing a common
pointer emulation code, thereby removing the need for the tracking id
in the driver.  This patch moves all tracking event handling over to
the input core, simplifying both the existing drivers and the ones
currently in preparation.

Acked-by: Ping Cheng <pingc@wacom.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 5 insertions, 16 deletions

diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index 4a2e8cf4c8ef..2a0bec12d12a 100644
--- a/drivers/input/touchscreen/wacom_w8001.c
+++ b/drivers/input/touchscreen/wacom_w8001.c
@@ -48,8 +48,6 @@ MODULE_LICENSE("GPL");
 #define W8001_PKTLEN_TPCCTL	11	/* control packet */
 #define W8001_PKTLEN_TOUCH2FG	13
 
-#define MAX_TRACKING_ID		0xFF	/* arbitrarily chosen */
-
 struct w8001_coord {
 	u8 rdy;
 	u8 tsw;
@@ -87,7 +85,6 @@ struct w8001 {
 	char phys[32];
 	int type;
 	unsigned int pktlen;
-	int trkid[2];
 };
 
 static void parse_data(u8 *data, struct w8001_coord *coord)
@@ -116,28 +113,23 @@ static void parse_data(u8 *data, struct w8001_coord *coord)
 
 static void parse_touch(struct w8001 *w8001)
 {
-	static int trkid;
 	struct input_dev *dev = w8001->dev;
 	unsigned char *data = w8001->data;
 	int i;
 
 	for (i = 0; i < 2; i++) {
-		input_mt_slot(dev, i);
+		bool touch = data[0] & (1 << i);
 
-		if (data[0] & (1 << i)) {
+		input_mt_slot(dev, i);
+		input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
+		if (touch) {
 			int x = (data[6 * i + 1] << 7) | (data[6 * i + 2]);
 			int y = (data[6 * i + 3] << 7) | (data[6 * i + 4]);
 			/* data[5,6] and [11,12] is finger capacity */
 
 			input_report_abs(dev, ABS_MT_POSITION_X, x);
 			input_report_abs(dev, ABS_MT_POSITION_Y, y);
-			input_report_abs(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER);
-			if (w8001->trkid[i] < 0)
-				w8001->trkid[i] = trkid++ & MAX_TRACKING_ID;
-		} else {
-			w8001->trkid[i] = -1;
 		}
-		input_report_abs(dev, ABS_MT_TRACKING_ID, w8001->trkid[i]);
 	}
 
 	input_sync(dev);
@@ -319,14 +311,12 @@ static int w8001_setup(struct w8001 *w8001)
 			w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
 
 			input_mt_init_slots(dev, 2);
-			input_set_abs_params(dev, ABS_MT_TRACKING_ID,
-						0, MAX_TRACKING_ID, 0, 0);
 			input_set_abs_params(dev, ABS_MT_POSITION_X,
 						0, touch.x, 0, 0);
 			input_set_abs_params(dev, ABS_MT_POSITION_Y,
 						0, touch.y, 0, 0);
 			input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
-						0, 0, 0, 0);
+						0, MT_TOOL_MAX, 0, 0);
 			break;
 		}
 	}
@@ -372,7 +362,6 @@ static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 	w8001->serio = serio;
 	w8001->id = serio->id.id;
 	w8001->dev = input_dev;
-	w8001->trkid[0] = w8001->trkid[1] = -1;
 	init_completion(&w8001->cmd_done);
 	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);