Re: [PATCH 5/5] Input: wacom_w8001 - split the touch and pen devices into two devices

These devices have a pen device and a touch device through the same serial
protocol, split it up into two separate devices like we do for USB Wacom
tablets too.

Userspace already matches on the device name so we can't drop it
completely. Compose the same basename based on capabilities and append the
tool type, leading to a name like "Wacom Serial Penabled 2FG Touchscreen
Pen".

Note that this drops BTN_TOOL_FINGER, it is not needed once the tools are
split out (and a touch device with BTN_TOOL_FINGER is interpreted as
touchpad by most of userspace).

Signed-off-by: Peter Hutterer <redacted>
Acked-by: Benjamin Tissoires <redacted>
---
 drivers/input/touchscreen/wacom_w8001.c | 163 ++++++++++++++++++++++----------
 1 file changed, 112 insertions(+), 51 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index 363e510..9efc7ec 100644
--- a/drivers/input/touchscreen/wacom_w8001.c
+++ b/drivers/input/touchscreen/wacom_w8001.c

@@ -80,7 +80,8 @@ struct w8001_touch_query {
  */
 
 struct w8001 {
-	struct input_dev *dev;
+	struct input_dev *pen_dev;
+	struct input_dev *touch_dev;
 	struct serio *serio;
 	struct completion cmd_done;
 	int id;

@@ -95,7 +96,10 @@ struct w8001 {
 	u16 max_touch_y;
 	u16 max_pen_x;
 	u16 max_pen_y;
-	char name[64];
+	char pen_name[64];
+	char touch_name[64];
+	int open_count;
+	struct mutex mutex;
 };
 
 static void parse_pen_data(u8 *data, struct w8001_coord *coord)

@@ -141,7 +145,7 @@ static void scale_touch_coordinates(struct w8001 *w8001,
 
 static void parse_multi_touch(struct w8001 *w8001)
 {
-	struct input_dev *dev = w8001->dev;
+	struct input_dev *dev = w8001->touch_dev;
 	unsigned char *data = w8001->data;
 	unsigned int x, y;
 	int i;

@@ -207,7 +211,7 @@ static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
 
 static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
 {
-	struct input_dev *dev = w8001->dev;
+	struct input_dev *dev = w8001->pen_dev;
 
 	/*
 	 * We have 1 bit for proximity (rdy) and 3 bits for tip, side,

@@ -233,11 +237,6 @@ static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
 		break;
 
 	case BTN_TOOL_FINGER:
-		input_report_key(dev, BTN_TOUCH, 0);
-		input_report_key(dev, BTN_TOOL_FINGER, 0);
-		input_sync(dev);
-		/* fall through */
-
 	case KEY_RESERVED:
 		w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
 		break;

@@ -261,7 +260,7 @@ static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
 
 static void report_single_touch(struct w8001 *w8001, struct w8001_coord *coord)
 {
-	struct input_dev *dev = w8001->dev;
+	struct input_dev *dev = w8001->touch_dev;
 	unsigned int x = coord->x;
 	unsigned int y = coord->y;
 

@@ -271,7 +270,6 @@ static void report_single_touch(struct w8001 *w8001, struct w8001_coord *coord)
 	input_report_abs(dev, ABS_X, x);
 	input_report_abs(dev, ABS_Y, y);
 	input_report_key(dev, BTN_TOUCH, coord->tsw);
-	input_report_key(dev, BTN_TOOL_FINGER, coord->tsw);
 
 	input_sync(dev);
 

@@ -369,20 +367,33 @@ static int w8001_command(struct w8001 *w8001, unsigned char command,
 static int w8001_open(struct input_dev *dev)
 {
 	struct w8001 *w8001 = input_get_drvdata(dev);
+	int err;
 
-	return w8001_command(w8001, W8001_CMD_START, false);
+	err = mutex_lock_interruptible(&w8001->mutex);
+	if (err)
+		return err;
+
+	if (w8001->open_count++ == 0)
+		err = w8001_command(w8001, W8001_CMD_START, false);