[PATCH v2 5/5] Input: wacom_w8001 - split the touch and pen devices into two devices

[Peter Hutterer <peter.hutterer@who-t.net>]

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 <peter.hutterer@who-t.net>
Acked-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
---
Changes to v1:
- don't leak open_count on error

 drivers/input/touchscreen/wacom_w8001.c | 167 ++++++++++++++++++++++----------
 1 file changed, 116 insertions(+), 51 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index de8f0e4..fe983e7 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 +367,36 @@ 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);
+		if (err)
+			w8001->open_count--;
+	}
+
+	mutex_unlock(&w8001->mutex);
+	return err;
 }
 
 static void w8001_close(struct input_dev *dev)
 {
 	struct w8001 *w8001 = input_get_drvdata(dev);
 
-	w8001_command(w8001, W8001_CMD_STOP, false);
+	mutex_lock(&w8001->mutex);
+
+	if (--w8001->open_count == 0)
+		w8001_command(w8001, W8001_CMD_STOP, false);
+
+	mutex_unlock(&w8001->mutex);
 }
 
 static int w8001_detect(struct w8001 *w8001)
 {
-	struct input_dev *dev = w8001->dev;
 	int error;
 
 	error = w8001_command(w8001, W8001_CMD_STOP, false);
@@ -391,18 +405,13 @@ static int w8001_detect(struct w8001 *w8001)
 
 	msleep(250);	/* wait 250ms before querying the device */
 
-	__set_bit(EV_KEY, dev->evbit);
-	__set_bit(EV_ABS, dev->evbit);
-	strlcat(w8001->name, "Wacom Serial", sizeof(w8001->name));
-
-	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
-
 	return 0;
 }
 
-static int w8001_setup_pen(struct w8001 *w8001)
+static int w8001_setup_pen(struct w8001 *w8001, char *basename,
+			   size_t basename_sz)
 {
-	struct input_dev *dev = w8001->dev;
+	struct input_dev *dev = w8001->pen_dev;
 	struct w8001_coord coord;
 	int error;
 
@@ -411,11 +420,14 @@ static int w8001_setup_pen(struct w8001 *w8001)
 	if (error)
 		return error;
 
+	__set_bit(EV_KEY, dev->evbit);
+	__set_bit(EV_ABS, dev->evbit);
 	__set_bit(BTN_TOUCH, dev->keybit);
 	__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);
+	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
 
 	parse_pen_data(w8001->response, &coord);
 	w8001->max_pen_x = coord.x;
@@ -432,17 +444,19 @@ static int w8001_setup_pen(struct w8001 *w8001)
 	}
 
 	w8001->id = 0x90;
-	strlcat(w8001->name, " Penabled", sizeof(w8001->name));
+	strlcat(basename, " Penabled", basename_sz);
 
 	return 0;
 }
 
-static int w8001_setup_touch(struct w8001 *w8001)
+static int w8001_setup_touch(struct w8001 *w8001, char *basename,
+			     size_t basename_sz)
 {
-	struct input_dev *dev = w8001->dev;
+	struct input_dev *dev = w8001->touch_dev;
 	struct w8001_touch_query touch;
 	int error;
 
+
 	/* Touch enabled? */
 	error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
 	if (error)
@@ -454,8 +468,10 @@ static int w8001_setup_touch(struct w8001 *w8001)
 	if (!w8001->response[1])
 		return -ENXIO;
 
+	__set_bit(EV_KEY, dev->evbit);
+	__set_bit(EV_ABS, dev->evbit);
 	__set_bit(BTN_TOUCH, dev->keybit);
-	__set_bit(BTN_TOOL_FINGER, dev->keybit);
+	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
 
 	parse_touchquery(w8001->response, &touch);
 	w8001->max_touch_x = touch.x;
@@ -478,14 +494,14 @@ static int w8001_setup_touch(struct w8001 *w8001)
 	case 2:
 		w8001->pktlen = W8001_PKTLEN_TOUCH93;
 		w8001->id = 0x93;
-		strlcat(w8001->name, " 1FG", sizeof(w8001->name));
+		strlcat(basename, " 1FG", basename_sz);
 		break;
 
 	case 1:
 	case 3:
 	case 4:
 		w8001->pktlen = W8001_PKTLEN_TOUCH9A;
-		strlcat(w8001->name, " 1FG", sizeof(w8001->name));
+		strlcat(basename, " 1FG", basename_sz);
 		w8001->id = 0x9a;
 		break;
 
@@ -501,7 +517,7 @@ static int w8001_setup_touch(struct w8001 *w8001)
 		input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
 					0, MT_TOOL_MAX, 0, 0);
 
-		strlcat(w8001->name, " 2FG", sizeof(w8001->name));
+		strlcat(basename, " 2FG", basename_sz);
 		if (w8001->max_pen_x && w8001->max_pen_y)
 			w8001->id = 0xE3;
 		else
@@ -509,11 +525,27 @@ static int w8001_setup_touch(struct w8001 *w8001)
 		break;
 	}
 
-	strlcat(w8001->name, " Touchscreen", sizeof(w8001->name));
+	strlcat(basename, " Touchscreen", basename_sz);
 
 	return 0;
 }
 
+static void w8001_set_devdata(struct input_dev *dev, struct w8001 *w8001,
+			      struct serio *serio)
+{
+	dev->phys = w8001->phys;
+	dev->id.bustype = BUS_RS232;
+	dev->id.product = w8001->id;
+	dev->id.vendor = 0x056a;
+	dev->id.version = 0x0100;
+	dev->open = w8001_open;
+	dev->close = w8001_close;
+
+	dev->dev.parent = &serio->dev;
+
+	input_set_drvdata(dev, w8001);
+}
+
 /*
  * w8001_disconnect() is the opposite of w8001_connect()
  */
@@ -524,7 +556,10 @@ static void w8001_disconnect(struct serio *serio)
 
 	serio_close(serio);
 
-	input_unregister_device(w8001->dev);
+	if (w8001->pen_dev)
+		input_unregister_device(w8001->pen_dev);
+	if (w8001->touch_dev)
+		input_unregister_device(w8001->touch_dev);
 	kfree(w8001);
 
 	serio_set_drvdata(serio, NULL);
@@ -539,18 +574,23 @@ static void w8001_disconnect(struct serio *serio)
 static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 {
 	struct w8001 *w8001;
-	struct input_dev *input_dev;
+	struct input_dev *input_dev_pen;
+	struct input_dev *input_dev_touch;
+	char basename[64];
 	int err, err_pen, err_touch;
 
 	w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
-	input_dev = input_allocate_device();
-	if (!w8001 || !input_dev) {
+	input_dev_pen = input_allocate_device();
+	input_dev_touch = input_allocate_device();
+	if (!w8001 || !input_dev_pen || !input_dev_touch) {
 		err = -ENOMEM;
 		goto fail1;
 	}
 
 	w8001->serio = serio;
-	w8001->dev = input_dev;
+	w8001->pen_dev = input_dev_pen;
+	w8001->touch_dev = input_dev_touch;
+	mutex_init(&w8001->mutex);
 	init_completion(&w8001->cmd_done);
 	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
 
@@ -563,38 +603,63 @@ static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 	if (err)
 		goto fail3;
 
-	err_pen = w8001_setup_pen(w8001);
-	err_touch = w8001_setup_touch(w8001);
+	/* For backwards-compatibility we compose the basename based on
+	 * capabilities and then just append the tool type
+	 */
+	strlcpy(basename, "Wacom Serial", sizeof(basename));
+
+	err_pen = w8001_setup_pen(w8001, basename, sizeof(basename));
+	err_touch = w8001_setup_touch(w8001, basename, sizeof(basename));
 	if (err_pen && err_touch) {
 		err = -ENXIO;
 		goto fail3;
 	}
 
-	input_dev->name = w8001->name;
-	input_dev->phys = w8001->phys;
-	input_dev->id.product = w8001->id;
-	input_dev->id.bustype = BUS_RS232;
-	input_dev->id.vendor = 0x056a;
-	input_dev->id.version = 0x0100;
-	input_dev->dev.parent = &serio->dev;
+	if (!err_pen) {
+		strlcpy(w8001->pen_name, basename, sizeof(w8001->pen_name));
+		strlcat(w8001->pen_name, " Pen", sizeof(w8001->pen_name));
+		input_dev_pen->name = w8001->pen_name;
 
-	input_dev->open = w8001_open;
-	input_dev->close = w8001_close;
+		w8001_set_devdata(input_dev_pen, w8001, serio);
 
-	input_set_drvdata(input_dev, w8001);
+		err = input_register_device(w8001->pen_dev);
+		if (err)
+			goto fail3;
+	} else {
+		input_free_device(input_dev_pen);
+		input_dev_pen = NULL;
+		w8001->pen_dev = NULL;
+	}
 
-	err = input_register_device(w8001->dev);
-	if (err)
-		goto fail3;
+	if (!err_touch) {
+		strlcpy(w8001->touch_name, basename, sizeof(w8001->touch_name));
+		strlcat(w8001->touch_name, " Finger",
+			sizeof(w8001->touch_name));
+		input_dev_touch->name = w8001->touch_name;
+
+		w8001_set_devdata(input_dev_touch, w8001, serio);
+
+		err = input_register_device(w8001->touch_dev);
+		if (err)
+			goto fail4;
+	} else {
+		input_free_device(input_dev_touch);
+		input_dev_touch = NULL;
+		w8001->touch_dev = NULL;
+	}
 
 	return 0;
 
+fail4:
+	if (w8001->pen_dev)
+		input_unregister_device(w8001->pen_dev);
 fail3:
 	serio_close(serio);
 fail2:
 	serio_set_drvdata(serio, NULL);
 fail1:
-	input_free_device(input_dev);
+	input_free_device(input_dev_pen);
+	input_free_device(input_dev_touch);
 	kfree(w8001);
 	return err;
 }
-- 
2.5.0