[PATCH 2/3 v2] input - wacom_w8001: Support pen or touch only devices

[PATCH 2/3 v2] input - wacom_w8001: Support pen or touch only devices

[Ping Cheng]

Not all penabled devices support touch. The same holds true for
touch devices. Setting up the devices according to the specific
querying results.

Signed-off-by: Ping Cheng <pingc@wacom.com>
---
 drivers/input/touchscreen/wacom_w8001.c |   42 ++++++++++++++++++++++---------
 1 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index 49bce13..59664a8 100644
--- a/drivers/input/touchscreen/wacom_w8001.c
+++ b/drivers/input/touchscreen/wacom_w8001.c
@@ -37,6 +37,7 @@ MODULE_LICENSE("GPL");
 
 #define W8001_QUERY_PACKET	0x20
 
+#define W8001_CMD_STOP		'0'
 #define W8001_CMD_START		'1'
 #define W8001_CMD_QUERY		'*'
 #define W8001_CMD_TOUCHQUERY	'%'
@@ -279,24 +280,45 @@ static int w8001_setup(struct w8001 *w8001)
 	struct w8001_coord coord;
 	int error;
 
-	error = w8001_command(w8001, W8001_CMD_QUERY, true);
+	error = w8001_command(w8001, W8001_CMD_STOP, false);
 	if (error)
 		return error;
 
-	parse_data(w8001->response, &coord);
+	mdelay(250);	/* wait 250ms before querying the device */
 
-	input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
-	input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
-	input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
-	input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
-	input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
+	/* penabled? */
+	error = w8001_command(w8001, W8001_CMD_QUERY, true);
+	if (!error) {
+		__set_bit(BTN_TOOL_PEN, dev->keybit);
+		__set_bit(BTN_TOOL_RUBBER, dev->keybit);
+		__set_bit(BTN_STYLUS, dev->keybit);
+		__set_bit(BTN_STYLUS2, dev->keybit);
+		parse_data(w8001->response, &coord);
+
+		input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
+		input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
+		input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
+		if (coord.tilt_x && coord.tilt_y) {
+			input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
+			input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
+		}
+	}
 
+	/* touch enabled? */
 	error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
-	if (!error) {
+
+	/* Some non-touch devices may reply to the touch query. But their
+	 * second byte is empty, which indicates touch is not supported.
+	 */
+	if (!error && w8001->response[1]) {
 		struct w8001_touch_query touch;
 
 		parse_touchquery(w8001->response, &touch);
 
+		input_set_abs_params(dev, ABS_X, 0, touch.x, 0, 0);
+		input_set_abs_params(dev, ABS_Y, 0, touch.y, 0, 0);
+		__set_bit(BTN_TOOL_FINGER, dev->keybit);
+
 		switch (touch.sensor_id) {
 		case 0:
 		case 2:
@@ -375,10 +397,6 @@ static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 
 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 	__set_bit(BTN_TOUCH, input_dev->keybit);
-	__set_bit(BTN_TOOL_PEN, input_dev->keybit);
-	__set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
-	__set_bit(BTN_STYLUS, input_dev->keybit);
-	__set_bit(BTN_STYLUS2, input_dev->keybit);
 
 	serio_set_drvdata(serio, w8001);
 	err = serio_open(serio, drv);
-- 
1.7.3.3